olma's scientific stuff

Опиаты более страшны для людей с психическими проблемами

2012-01-05T14:33:00.000+02:00

С праздничками, коллеги!
Вот вам свежая новость от капитана Очевидность.

Оказывается, люди с психическими расстройствами (биполярный психоз, депрессия и т.д.) более подвержены зависимости от опиатов. Полный текст на http://www.biologynews.net/archives/2011/12/13/opioid_abuse_linked_to_mood_and_anxiety_disorders_.html
Да вы что!1111111111111 Оо

Эффекты разных психоактивных веществ на уровне синапсов

2011-12-24T17:01:00.000+02:00

Простенько, но со вкусом.
http://faculty.plattsburgh.edu/donald.slish/DA.html

Т-щи учёные, с Наступающим!

2011-12-24T14:40:00.000+02:00

Ёлочка на чашке Петри. Из грибов. Из тумблера).

Допамин в свежих научных новостях

2011-12-20T15:16:00.001+02:00

Я очень люблю допамин. Да и как можно его не любить, если именно это чудесное вещество отвечает за нашу мотивацию, удовольствие и другие приятности? В этом блоге достаточно много постов посвящены этому нейромедиатору, поэтому сейчас я хочу поделиться ссылкой на свежайшую статью из авторитетного источника, в которой раскрываются какие-то интересные и не известные до этого, сведения о допамине.

Сообщение на http://www.eurekalert.org/pub_releases/2011-12/osum-ans120111.php гласит, что допамин может быть крайне полезен при лечении опухолей. Оказывается, этот катехоламин способен увеличить эффективность действия противораковых препаратов и радиотерапии! Допамин улучшает приток крови к опухолям и таким образом повышает концентрацию действующих веществ именно в месте потребности, так же увеличивается уровень насыщения этих участков кислородом, что так же способствует борьбе с опухолью. Такие результаты были получены на животных моделях рака груди и кишечника.

1 из 5 американцев сидит на психоактивных лекарствах

2011-11-30T17:42:00.001+02:00

Оптимистичненько так. Называется, сделай сам - настроение? - а зачем, ведь есть таблетки, которые создадут любое настроение.
Вот такой интересный материал на http://blisstree.com/feel/1-in-5-americans-on-mental-health-drugs-overmedicating-817/ советую вам почитать для размышлений:

Almost half of all Americans take at least one prescription drug, and now a new report tells us that more than 20% of us take at least one medication to treat a mental health problem–a number that is up 22% since 2001. It’s an alarming trend for sure, and has us wondering: Are all of these drugs really necessary, or are Americans over-medicated?
Granted, mental health disorders are a serious illness which require serious treatment. According to the statistics released by Medco Health Solutions, more than a quarter of us suffer from mental health problems which have us taking antidepressants, antipsychotics, attention deficit hyperactivity disorder drugs or anti‐anxiety treatments every year. And women are far more likely to take a drug to treat a mental health condition than men with those over 45 showing the highest use.
And yet, the World Health Organization says this doesn’t necessarily mean that we are over-medicated.
So what does it mean? Are more Americans just getting diagnosed with depression, anxiety or other mental health disorders? Are these conditions becoming more prevalent? Or, are doctors simply taking the easy way out and prescribing more drugs than necessary without exploring other alternate treatments first for less severe cases?
In Charles Barber’s Comfortably Numb: How Psychiatry Is Medicating a Nation, the New York Times stated that he makes a case for Americans being “vastly overmedicated for often relatively minor mental health concerns”. There is also the theory to the sharp rise in mental health medications: We are asking for them. TheNY Times also suggested that we are a self-drugging society in many respects. We are often too quick to pop pills when something doesn’t feel quite right. Many of us use alcohol to numb feelings of stress, anxiety and depression. It was even suggested that some Americans are taking mental health medications for “ficticious concerns”. For that, we can point a finger to all of the marketing and advertising that the drug companies are doing (over $5 billion a year) that suggest we may have a problem (even though we thought we were fine until we saw their commercial telling us how depressed we are).
In a recent Blisstree post, I talked about the fact that some doctors think depression could actually be good for usbecause it forces us to face our issues and dissect exactly what is happening in our lives and in our head. Because of this, some doctors still think that other mental health treatments like talk therapy should be explored first because putting a pharmaceutical bandage over our depression or anxiety can often preclude us from uncovering our source of true happiness. Other experts have also suggested that a healthy diet, stress-reduction and even yoga can help bring us back to a positive mental state.
Tell us what you think. Are Americans too quick to take mental health medications?

Я ещё и там

2011-11-05T00:48:00.002+02:00

И кстати, уважаемые. Большой и тёплый велкам на http://my.science.ua/my/OlgaMaslova/. Любезно согласилась там периодически радовать народ околобиологическими вкусняшками. Ресурс вообще молодой, но создан с очень альтруистично-эпистемологическим задумом. Надеюсь, все молодые (и не очень) блоговеды "из оттуда" сделают его реально стоящим и крутым. Чего нам (да и вам) и желаю. :)

Про мужчин и восприимчивость к алкоголю

2011-11-04T22:42:00.001+02:00

Читаем:

Alcohol is one of the most commonly abused substances, and men are up to twice as likely to develop alcoholism as women. Until now, the underlying biology contributing to this difference in vulnerability has remained unclear. A new study published in Biological Psychiatry reveals that dopamine may be an important factor.
Researchers from Columbia and Yale studied male and female college-age social drinkers in a laboratory test of alcohol consumption. After consuming an alcoholic or non-alcoholic drink, each participant underwent a specialized positron emission tomography (PET) scan, an imaging technique that can measure the amount of alcohol-induced dopamine release.
Dopamine has multiple functions in the brain, but is important in this context because of its pleasurable effects when it is released by rewarding experiences, such as sex or drugs. Despite similar consumptions of alcohol, the men had greater dopamine release than women. This increase was found in the ventral striatum, an area in the brain strongly associated with pleasure, reinforcement and addiction formation.
"In men, increased dopamine release also had a stronger association with subjective positive effects of alcohol intoxication," explained Dr. Nina Urban, corresponding author for this study. "This may contribute to the initial reinforcing properties of alcohol and the risk for habit formation." Dr. Anissa Abi-Dargham, senior author on this project, notes that "another important observation from this study is the decline in alcohol-induced dopamine release with repeated heavy drinking episodes. This may be one of the hallmarks of developing tolerance or transitioning into habit."
These findings indicate that the ability of alcohol to stimulate dopamine release may play an important and complex role in its rewarding effects and abuse liability in humans. This identification of an in vivo neurochemical mechanism that could help explain the sex difference in alcoholism is an exciting step forward in alcoholism research.
Source : Elsevier

http://www.molecularstation.com/forum/science-news-views/83485-why-men-more-susceptible-alcoholism.html

Паразит мозг не съест, но химию его изменит...

2011-11-04T22:40:00.001+02:00

Сто лет не обновляла этот бложик, пардон.
Вот вам забавная новость. На английском, ага, как обычно.
Некоторые паразиты (токсоплазма, например) в мозгу могут феерически изменять выработку допамина.

Brain parasite directly alters brain chemistry

A research group from the University of Leeds has shown that infection by the brain parasite Toxoplasma gondii, found in 10-20 per cent of the UK's population, directly affects the production of dopamine, a key chemical messenger in the brain.

Their findings are the first to demonstrate that a parasite found in the brain of mammals can affect dopamine levels.

Whilst the work has been carried out with rodents, lead investigator Dr Glenn McConkey of the University's Faculty of Biological Sciences, believes that the findings could ultimately shed new light on treating human neurological disorders that are dopamine-related such as schizophrenia, attention deficit hyperactivity disorder, and Parkinson's disease.

This research may explain how these parasites, remarkably, manipulate rodents' behaviour for their own advantage. Infected mice and rats lose their innate fear of cats, increasing the chances of being caught and eaten, which enables the parasite to return to its main host to complete its life cycle.

In this study, funded by the Stanley Medical Research Institute and Dunhill Medical Trust, the research team found that the parasite causes production and release of many times the normal amount of dopamine in infected brain cells.

Dopamine is a natural chemical which relays messages in the brain controlling aspects of movement, cognition and behaviour. It helps control the brain's reward and pleasure centres and regulates emotional responses such as fear. The presence of a certain kind of dopamine receptor is also associated with sensation-seeking, whereas dopamine deficiency in humans results in Parkinson's disease.

These findings build on earlier studies in which Dr McConkey's group found that the parasite actually encodes the enzyme for producing dopamine in its genome.

"Based on these analyses, it was clear that T. gondii can orchestrate a significant increase in dopamine production in neural cells," says Dr McConkey.

"Humans are accidental hosts to T. gondii and the parasite could end up anywhere in the brain, so human symptoms of toxoplasmosis infection may depend on where parasite ends up. This may explain the observed statistical link between incidences of schizophrenia and toxoplasmosis infection."

Dr McConkey says his next experiments will investigate how the parasite enzyme triggers dopamine production and how this may change behaviour.
http://www.eurekalert.org/pub_releases/2011-11/uol-bpd110411.php

Комикс про Кюри

2011-08-17T13:21:00.000+03:00

Мария Кюри очень знает толк в гениальности!
Картинка кликабельна.

Новый фон научных заметок

2011-07-20T14:37:00.000+03:00

Опять некоторые изменения в дизайне. Не знаю, долго ли я выдержу такой весёлый фон, но пока что мне он показался весьма настроенческим и подходящим под научный контент блога. Надеюсь, успешность проекта от этого только возрастёт!
Оставайтесь на связи, дорогие почемучки и любители научных новостей! :)

Женщины с поликистозом яичников более восприимчивы к бисфенолу А

2011-07-17T18:19:00.000+03:00

Последние исследования указывают на зависимость между вредом, наносимым таким распространённым веществом как бисфенол А и наличием у женщин синдрома поликистоза яичников (очень популярного гинекологического заболевания). Статья с http://scienceblog.com/41751/women-with-polycystic-ovary-syndrome-may-be-more-vulnerable-to-bpa:

Chevy Chase, MD — A recent study accepted for publication in The EndocrineSociety’s Journal of Clinical Endocrinology & Metabolism(JCEM), found higher Bisphenol A (BPA) levels in women with polycystic ovary syndrome (PCOS) compared to controls. Furthermore, researchers found a statistically significant positive association between male sex hormones and BPA in these women suggesting a potential role of BPA in ovarian dysfunction.BPA is a very common industrial compound used in food and drink packaging, plastic consumer products and dental materials. PCOS is the most common endocrine disorder of women of reproductive age and is characterized by excessive secretion of androgens which are masculinization-promoting hormones. The syndrome raises the risk of obesity, type 2 diabetes, infertility and heart disease.“Our research shows that BPA may be more harmful to women with hormonal and fertility imbalances like those found in PCOS,” said Evanthia Diamanti-Kandarakis, MD, PhD, study co-author and professor at the University of Athens Medical School in Greece. “These women should be alert to the potential risks and take care of themselves by avoiding excessive every-day consumption of food or drink from plastic containers.”In this study, researchers divided 71 women with PCOS and 100 healthy female control subjects into subgroups matchedby age and body composition. Blood levels of BPA were nearly 60 percent higher in lean women with PCOS and more than 30 percent higher in obese women with the syndrome when compared to controls. Additionally, as BPAlevels increased, so did concentrations of the male sex hormone testosterone and androstenedione, a steroid hormone that converts to testosterone.
“Excessive secretion of androgens, as seen in PCOS, interfere with BPA detoxification by the liver, leading to accumulation of blood levels of BPA,” said Diamanti-Kandarakis. “BPA also affects androgen metabolism, creating a vicious circle between androgens and BPA.”Other researchers working on the study include: Eleni Kandaraki of Huddersfield Royal Infirmary Hospital in West Yorkshire, United Kingdom; Antonis Chatzigeorgiou, Sarantis Livadas, Eleni Palioura, Frangiscos Economou, Michael Koutsilieris and Sotiria Palimeri of National and Kapodistrian University of Athens in Greece; and Dimitrios Panidis of Aristotle University of Thessaloniki in Greece.The article, “Endocrine disruptors and polycystic ovary syndrome (PCOS): Elevated serum levels of Bisphenol A in women with PCOS,” appears in the March 2011 issue ofJCEM.Founded in 1916, The Endocrine Society is the world’s oldest, largest and most active organization devoted to research on hormones and the clinical practice of endocrinology. Today, The Endocrine Society’s membership consists of over 14,000 scientists, physicians, educators,nurses and students in more than 100 countries. Society members represent all basic, applied and clinical interests in endocrinology. The Endocrine Society is based in Chevy Chase, Maryland. To learn more about the Society and the field of endocrinology, visit our site at www.endo-society.org.

Прощай, Прозак, Привет, Микроб!

2011-07-08T10:16:00.001+03:00

В сфере поиска новых эффективных антидепрессантов - революция. Вероятно, что состав микрофлоры кишечника может влиять на ментальное состояние достаточно сильно. Поэтому приём правильных пробиотиков, в определённом смысле, сможет снизить потре6ность в традиционных антидепрессантах.
Читаем подробнее статью Elizabeth Nolan Brown на http://blisstree.com/feel/goodbye-prozac-hello-microbial-bacteria/:

Probiotics are the good-for-you bacteria found in things such as yogurt and kombucha (plus in myriad dietary supplement forms) and alleged to help with digestion, immune-system functioning, stomach issues, diarrhea, lactose intolerance and irritable bowel syndrome. Mark Lyte, a professor at Texas Tech University interested in the intersection of microbiology and neuroscience, thinks neurochemicals (such as serotonin) delivered directly to the gut via probiotics could help not just with gastrointestinal health but also psychological well-being.

Lyte’s theory, which was published in the July issues of BioEssays, has yet to be tested in humans. In a commentary in the same issue of BioEssays, though, Dr. Gregor Reid of the University of Western Ontario says the idea is supported by studies. “Could this mean that adjunct treatment for people suffering from certain types of mental health problems is a fecal transplant? Food for thought,” writes Reid (scientist humor!). Research on mice has shown microbial bacteria can produce and respond to neurochemicals, and that the connection between gut microbes and the nervous system provides “a viable route for influencing neurological function.”

Ресвератрол - источник полезностей в красном вине

2011-07-02T19:08:00.000+03:00

О пользе красного вина написано достаточно много. Вот - очередные новости о весьма интересном компоненте - ресвератроле, который скорее всего обладает канцеропротекторными свойствами:

FANCY receiving the heart protecting abilities of red wine without having to drink a glass every day? Soon you may be able to, thanks to the synthesis of chemicals derived from resveratrol, the molecule believed to give wine its protective powers. The chemicals have the potential to fight many diseases, including cancer.

Plants make a huge variety of chemicals, called polyphenols, from resveratrol to protect themselves against invaders, particularly fungi. But they only make tiny amounts of each chemical, making it extremely difficult for scientists to isolate and utilise them. The unstable nature of resveratrol has also hindered attempts at building new compounds from the chemical itself.

Scott Snyder at Columbia University in New York and his team have found a way around this: building polyphenols from compounds that resemble, but are subtly different to, resveratrol. These differences make the process much easier. Using these alternative starting materials, they have made dozens of natural polyphenols, including vaticanol C, which is known to kill cancer cells (Nature, DOI: 10.1038/nature10197).

http://www.newscientist.com/article/mg21028185.300-red-wines-heart-health-chemical-unlocked-at-last.html

Хроническое употребление кетамина разрушает клетки мочевого пузыря

2011-06-16T22:21:00.001+03:00

Chronic ketamine use kills bladder cells - health - 15 June 2011 - New Scientist - статейка о новом исследовании о вреде кетамина, который раньше массово использовали для наркоза, а совсем недавно предлагали использовать как антидепрессант даже для лечения детей (в минимальных дозах). Внезапно оказалось, что это вещество способно необратимо изменять состояние клеток мочевого пузыря.

У жестоких людей сильнее развита мезолимбическая область

2011-06-07T13:32:00.002+03:00

Век живи - век учись. Оказывается, различия в поведении людей (например, степень жестокости) может выражаться в банальных морфофизиологических параметрах. Так, у жестоких людей, согласно результатам сканирования мозга, оказались значительно сильнее развиты мезолимбические участи головного мозга. Также, более жестокие люди, по статистике, имеют больше серого вещества. Читаем:

Brain Scans Show Violent People Have Bigger Mesolimbic Areas

Бисфенол-А - очередные новости

2011-06-03T10:17:00.001+03:00

Недавно у нас работе было сооружено нечто из одного из самых источающих бисфенол-А материалов. Удалось уговорить снести ту штуковину, только показав кучу литературы о вреде и коварстве бисфенола-А. Однако, работы весьма противоречивы и достаточное количество авторов утверждает, что вред не так уж и выражен.
И вот очередное сообщение:

Neuropharmacology. 2011 May 5. [Epub ahead of print]

Sex-specific influence of exposure to bisphenol-A between adolescence and young adulthood on mouse behaviors.

Xu X, Tian D, Hong X, Chen L, Xie L.

Source

Chemistry and Life Sciences College, Zhejiang Normal University, 688# Yinbin Road, Jinhua 321004, PR China; Psychology Research Center, Zhejiang Normal University, PR China.

Abstract

Bisphenol-A (BPA) is one of the most common environmental endocrine disrupters and has a wide range of effects on central nervous system. Adolescence is another important developmental period besides the early critical prenatal and neonatal periods. In the present study, we exposed mice to BPA (40, 400 μg/kg/d) between adolescence and young adulthood for 8 weeks and investigated its effects on the non-reproductive behaviors. In open field tests, rearing and grooming sex differences were abolished by BPA exposure. In the elevated plus maze test, the number of open arm entries, the time spent in open arms, and the number of unprotected head dips in the center area were reduced in males but increased in females by BPA at 40 or 400 μg/kg/d, thus eliminating or reversing sex differences in these behaviors. In the Morris water maze task, exposure to BPA at 40 μg/kg/d significantly extended the average escape pathlength to the hidden platform in males, but no significant influence was found in females; thus, the sex differences in spatial learning and memory were abolished. In the step-down test, the latency to step down from the platform 24 h after receiving a footshock was shortened by BPA exposure in males but not in females; thus, a sex difference was induced in passive avoidance memory in mice. These results suggest that long-term exposure to low levels of BPA between adolescence and young adulthood alters characteristic differences in certain non-reproductive behaviors of males and females, including exploration, anxiety, spatial learning and memory, and passive avoidance memory, although no obvious changes were found in the serum hormone levels or in the weights of reproductive organs.

Copyright © 2011. Published by Elsevier Ltd.

PMID:

21570416

[PubMed - as supplied by publisher]

Заставь голову варить лучше!

2011-05-29T22:21:00.001+03:00

Советики - как заставить мозг работать эффективней:

1. Time it right
Most older people think more clearly in the morning; most younger people, in the afternoon. Work out when your own best 'thinking time' is and set it aside it for your most challenging brain work.

2. Get a good education - but don't overdo it
Psychologist Dean Keith Simonton says that too much specialised higher education can damage your ability to think creatively. 'You don't become a great novelist by getting a PhD in creative writing.'

3. Listen to Confucius
Writing things down is the number one memory aid used by memory researchers themselves. As the Chinese proverb puts it, the weakest ink lasts longer than the best memory.

4. Kick start your day
Research shows that the amount of caffeine in a cup of coffee can help you concentrate. But if you're prone to anxiety, you're probably better off avoiding it.

5. Anchor new memories to established ones
'Think of your existing memory as a scaffold upon which to fit new information,' says cognitive researcher Denise Park. 'Don't isolate new information. Always relate it to something.'

6. Practise, practise, practise
Learning and repeatedly practising new skills appears to change the brain's internal organisation. A study showed that periodic training sessions helped volunteers in their 70s perform better in cognitive and memory tasks than they had when they were seven years younger. 'Practice really helps,' says psychologist Len Giambra. 'A well-practised older person will be faster than an unpractised younger person.'

7. Give your ideas a chance
Many of us are rewarded for our abilities to rapidly evaluate facts and make quick decisions. Creativity demands a much more leisurely and playful approach - a willingness to give 'absurd' ideas a chance.

8. Pick a stimulating profession and an intelligent partner
Intriguing studies from Poland suggest that people whose careers demand they exercise their intellect are more likely to sustain high levels of mental performance during their lives. Marrying someone intelligent may also provide you with ongoing stimulation.

9. Expose yourself to multiple experiences
Creativity often boils down to the ability to adapt solutions from one aspect of life to another. Velcro for instance, was inspired by burrs that stick to your clothing. The 'ring-pull' top on cans was originally based on the way a banana is peeled.

10. Learn from Leonardo
In his book, How to Think Like Leonardo da Vinci, author Michael Gelb offers several brain-enriching strategies that worked for the ultimate Renaissance man. Among them: learning to juggle and drawing with your non-writing hand.

Найдено у http://silabus-rpp.blogspot.com/2010/07/10-ways-to-think-better.html

by: Mendim

Клетки кожи могут думать?

2011-05-27T23:39:00.000+03:00

Феерические новости - клетки кожи генерируют сигналы и очень странно себя ведут. Подробный анализ этого интереснейшего предположения предлагаю рассмотреть, спасибо Dr. Jeffrey H. Toney, который написал статью у себя в блоге http://scienceblogs.com/deanscorner/2011/05/could_skin_cells_think.php:

Figure 4: Synaptic responses of HFF-iN cells.

There seems to be a brain-centric theme emerging this week in groundbreaking science. Scientists at the Stanford University School of Medicine have reported in Nature the first example of transforming human skin cells into functional nerve cells. Could skin cells someday be able to "think"? Could they be used to create a biological computer or in regenerative medicine?

How did they do it? Excerpted, and revised for clarity, from their Abstract: {my comments in italics}

Somatic cell nuclear transfer, cell fusion, or expression of lineage-specific factors have been shown to induce cell-fate changes in a variety of cell types. We recently observed that forced expression of a combination of three transcription factors {factors that affect how genes become expressed} can efficiently convert mouse fibroblasts into functional induced neuronal (iN) cells13. Here we show that the same three factors can generate functional neurons from human pluripotent stem cells as early as 6 days after transgene activation. Importantly, the vast majority of human iN cells were able to generate action potentials and many matured to receive synaptic contacts when co-cultured with primary mouse cortical neurons. Our data demonstrate that non-neural human somatic cells, as well as pluripotent stem cells, can be converted directly into neurons by lineage-determining transcription factors. These methods may facilitate robust generation of patient-specific human neurons for in vitro disease modelling or future applications in regenerative medicine.

Their conclusions:

In this report, we have identified a combination of transcription factors that are capable of converting human fibroblasts directly into neurons. Like mouse iN cells13 and neurons derived from ES cells19, 20, 21 and iPS cells22, 23, the human iN cells seem relatively immature, as indicated by their slightly depolarized membrane potentials and the relatively low-amplitude synaptic responses. Compared to mouse iN cells, human iN cells required longer culture periods to develop synaptic activity. Future studies will be necessary to thoroughly optimize conditions for human iN cell generation and maturation, which would facilitate applications of this method for the study of human neuronal development and disease.

This is, yet another, amazing example of a creative use of biological techniques to generate something thought to be impossible in the past - transforming a common skin cell into a functioning neuron!

Обновился дизайн блога

2011-05-27T15:54:00.000+03:00

Дорогие читатели, обратите внимание - старый порядком надоевший тяжёлый фиолетовый дизайн превращён в нечто более воздушное. Надеюсь, вам тоже нравится! :)

Антидепрессанты и диабет

2011-05-27T13:53:00.001+03:00

Привычные антидепрессанты в некоторых комбинациях приводят к развитию диабета! Читаем подробнее на:

Common drug combo increases diabetes risk - health - 26 May 2011 - New Scientist

Юмороват с функциями

2011-05-16T22:29:00.000+03:00

Баян, да. Но хороший:

Плацебо-новости

2011-05-14T20:58:00.000+03:00

Статья из журнала http://scienceblog.com/ о Плацебо :
They may be uncomfortable talking about it, but it’s definitely going on.
A recent survey, led by McGill Psychiatry Professor and Senior Lady Davis Institute Researcher Amir Raz, reports that one in five respondents – physicians and psychiatrists in Canadian medical schools – have administered or prescribed a placebo. Moreover, an even higher proportion of psychiatrists (more than 35 per cent) reported prescribing subtherapeutic doses of medication (that is, doses that are below, sometimes considerably below, the minimal recommended therapeutic level) to treat their patients.
Prescribing pseudoplacebos – that is treatments that are active in principle, but that are unlikely to be effective for the condition being treated, e.g., using vitamins to treat chronic insomnia – is more widespread than we may have thought according to the survey. Dr. Raz and his colleagues suggest that this may be because physicians have shown themselves to be more prepared to prescribe biochemically active materials even though at lower doses than might be effective.
The survey, which was also designed to explore attitudes toward placebo use, found that the majority of responding psychiatrists (more than 60 per cent) believe that placebos can have therapeutic effects. This is a significantly higher proportion than for other medical practitioners. “Psychiatrists seem to place more value in the influence placebos wield on the mind and body,” says Raz. Only 2 per cent of those psychiatrists believe that placebos have no clinical benefit at all.
Raz’s own interest in placebos grew out of his work in three very different areas: his explorations into how people’s physiology is influenced by their expectations of what is about to happen, his work on deception; and the time he spent as a former magician. Together, these three separate areas of experience have led Raz to explore what remains an uncomfortable hinterland of medical practice for many practitioners – the use of placebos in medicine.
“While most physicians probably appreciate the clinical merits of placebos, limited guidelines and scientific knowledge, as well as ethical considerations, impede open discussion about the best way we may want re-introduce placebos into the medical milieu,” says Raz. He adds, “This survey provides a valuable starting point for further investigations into Canadian physicians’ attitudes towards and use of placebos.”
http://scienceblog.com/45325/the-power-of-placebos/

Допаминово-серотониновые новости :)

2011-05-08T19:51:00.003+03:00

Пабмед принёс новую пачку статей о допаминергической и серотонинергической системах:

Neuropharmacology. 2011 Apr 12.
Enhanced effects of amphetamine but reduced effects of the hallucinogen, 5-MeO-DMT, on locomotor activity in 5-HT(1A) receptor knockout mice: Implications for schizophrenia.

van den Buuse M, Ruimschotel E, Martin S, Risbrough VB, Halberstadt AL.

Behavioural Neuroscience Laboratory, Mental Health Research Institute, Parkville, Melbourne, Australia; Department of Pharmacology, University of Melbourne, Australia.

Neuropharmacology. 2011 Apr 15.
Possible involvement of serotonin 5-HT2 receptor in the regulation of feeding behavior through the histaminergic system.

Murotani T, Ishizuka T, Isogawa Y, Karashima M, Yamatodani A.

Department of Medical Science and Technology, Division of Health Sciences, Graduate School of Medicine, Osaka University, 1-7 Yamadaoka, Suita, Osaka 565-0871, Japan.

Neuropharmacology. 2011 Apr 17.
Differential effects of cocaine and MDMA self-administration on cortical serotonin transporter availability in monkeys.

Gould RW, Gage HD, Banks ML, Blaylock BL, Czoty PW, Nader MA.

Department of Physiology and Pharmacology, Wake Forest University School of Medicine, Winston-Salem, NC 27157, United States.

Neuropharmacology. 2011 Apr 19.
Dopamine-related drugs act presynaptically to potentiate GABA(A) receptor currents in VTA dopamine neurons.

Michaeli A, Yaka R.

Institute for Drug Research, School of Pharmacy, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem, Israel.

Neuropharmacology. 2011 Apr 7.
High concentrations of MDMA ('ecstasy') and its metabolite MDA inhibit calcium influx and depolarization-evoked vesicular dopamine release in PC12 cells.

Hondebrink L, Meulenbelt J, Meijer M, van den Berg M, Westerink RH.

Neurotoxicology Research Group, Institute for Risk Assessment Sciences (IRAS), Utrecht University, P.O. Box 80.177, NL-3508 TD Utrecht, The Netherlands; National Poisons Information Centre (NVIC), National Institute for Public Health and the Environment (RIVM), P.O. Box 1, NL-3720 BA, Bilthoven, The Netherlands.

Кое-что новое о парацетамоле

2011-05-03T19:51:00.001+03:00

Ацетаминофен, он же - парацетамол, при передозировке может приводить к разным последствиям. Этот, казалось бы безопасный и популярный препарат может способствовать развитию заболеваний печени.

Acetaminophen Overdose May Be Painkiller Confusion

Всё кажется сексуальным, если человек в определённом настроении

2011-04-28T12:06:00.000+03:00

Забавные выводы о степени возбуждённости и восприятия эротического контекста:

Maybe our culture-deprived society needs to get out of the house and experience more art. A new study suggests that women find Georgia O’Keefe paintings “erotic” during their menstrual cycle, which is pretty much a no-brainer, considering O’Keefe’s flower paintings are infamous for their uncanny resemblance to female genitalia. According to researcher Jeffrey Rudski, a psychologist at Muhlenberg College in Pennsylvania, who published the study in the Archives of Sexual Behavior, participants were more likely to use sexual terms to describe O’Keeffe’s art in the days leading up to and including ovulation. After ovulation, the paintings appeared less suggestive. By Georg(ia), put down that O’Keefe-reefer, and get a grip. O’Keefe is no more erotic than Michaelangelo’s David. But when you’re experiencing raging hormones from hell during your menstrual cycle, trust me, everything is erotic.
I wouldn’t classify myself as someone with an abnormally large sex drive, but I have the same “appetite,” if you will, as the next red-blooded gal. And when my body begins to pump out the hormones faster than a teenage boy, everything I look at with remotely suggestive-imagery becomes erotic. National Geographic photo spreads, Ken dolls, football games (men with massive shoulders patting each others’ bottoms! HAWT), hard-boiled eggs, tall glasses of milk, even perps in handcuffs being shoved into a cop cruiser. Don’t ask me why, but my cheeks get redder than a Red Delicious orchard on harvest day.
So what exactly is this study trying to prove? I don’t actually see a benefit to singling out O’Keefe’s work as particularly erotic. They’re just flowers. Whether O’Keefe intended them to look like va-jay-jay’s is up for debate, but surely the purpose of art is to ask questions, provoke thought, and take you on an emotional journey. If that journey is toward SexyTown, so be it, but this study feels like old news retold with a new twist.
If you want erotic imagery, we have this nifty invention called The Internets where saucy Jpegs and naughty AVIs can be viewed at your leisure. Leave O’Keefe and her flowering lady-bits alone.

Post from: BlissTree
Newsflash: Everything Looks Erotic When You're Horny

Передозировки лекарствами

2011-04-27T15:53:00.002+03:00

Оказывается, в США существует проблема, выходящая на уровень эпидемии.
Подробнее об этом в статье: Narcotic pain relief drug overdose deaths a national epidemic

О том, как в мозгу генерируется музыка!

2011-04-04T15:41:00.003+03:00

Creativity and the Brain: Learning From Jazz Musicians and Rappers

Category: Nifty Fifty
Posted on: April 1, 2011 10:00 AM, by Joanna Pool

How does the brain create and perceive music? More specifically, what goes on inside the heads of musicians when they're in the groove composing a song or improvising with their instruments or voice? These questions have long intrigued researcher Charles Limb, and to find answers he's turned to studying the brains of some likely individuals: jazz musicians and rap artists.

In this quest, Charles brings some interesting credentials. He's an auditory surgeon by training, specializing in a surgery called cochlear implantation - a way to help deaf people hear again. He currently practices at Johns Hopkins University Hospital in Baltimore where he is Associate Professor of Otolaryngology, Head & Neck Surgery. Charles is also a musician, playing the sax, piano and bass, and serves on the faculty of Johns Hopkins' Peabody Conservatory of Music.

Says Charles: "I feel really lucky to be able to combine all of these passions in searching for a better understanding of how the mind perceives complex auditory stimuli such as music, and what parts of the brain are involved in musicians when they are deep in the process of creating and improvising."

In conducting his research, he uses functional brain imaging (fMRI) -- a technique that can measure the changes in blood flow within the brain, indicating neural activity -- to study musicians' brain regions as they improvise music on a small keyboard. For the past decade, he's been working with jazz piano players, revealing astonishing new data about the way the brain creates art.

His research has also recently branched into a new genre: hip-hop. Although originally
more of a jazz and classical music fan, Charles became increasingly intrigued by hip-hop's raw, grassroots characteristics the more he heard the music. He also soon realized striking similarities between jazz and rap which he found relevant for his study.

Read more about Charles here.

Watch a bit about studying how the brain reacts to creative situations. What activities do you think would be interesting to understand how the brain works during those activities?

Статья с http://scienceblogs.com/usasciencefestival/2011/04/creativity_and_the_brain_learn.php там же можно посмотреть видео

О лечении пристрастия к кокаину

2011-03-19T00:57:00.000+02:00

Радикальный метод - прямое влияние на мозг:

Статья опубликована в http://blog.the-scientist.com/2011/02/15/cocaine/ By Cathryn Denney

It’s clearly no longer just the drug of the young, rich and trendy: a decrease in street value over the years has led to a marked rise in usage and availability of cocaine, and it’s an ever-present favourite with the media. The BBC news website alone has dozens of cocaine-related news results since the beginning of the year (who knew the Highland Games were such a rave!).

The short lived euphoric effects of cocaine and subsequent come down lead to a physical and psychological addiction that cause a user to increase their frequency of intake. Using rats that could self-administer cocaine, Christelle Baunez and colleagues at the French National Center for Scientific Research looked at the effects of lesions in the subthalamic nucleus (STN) on addiction.
Following on from earlier work demonstrating that deep brain stimulation of the STN can reduce motivation of rats to work to get the drug¹, but increase motivation to work for food, they tested the hypothesis that lesions in the STN could prevent an escalation in cocaine intake. As described in a poster presented at the Neuroscience 2010 meeting, they found that treated rats decreased the number of times they helped themselves to cocaine, but with no ill effects on memory or locomotion.
“This has potential implications for the treatment of addicts,” suggests F1000 Section Head Trevor W. Robins of the University of Cambridge, in his evaluation of the poster. Baunez adds, “Before translating it to human addicts, the best thing will be to test the effects of STN inactivation in monkeys, which is one of our plans for the future.”

Феерическое видео о "двойном рождении" кенгуру

2011-03-14T23:11:00.002+02:00

Слабонервным, конечно, лучше отвернуться, но ценители смогут в миллионный раз удивиться мудрости природы

Can't Dance? Blame GABA, Not ABBA

2011-03-14T23:04:00.000+02:00

Can't Dance? Blame GABA, Not ABBA

Очень интересная статья, объясняющая неспособность людей к точному повторению танцевальных движений, через призму ГАМК-сигналинга.
Оказывается, высокие уровни этого нейромедиатора свойственны людям у которых хорошо развита как мелкая моторика, так и способность воспроизводить движения танца.

О влюблённом мозге и поцелуях

2011-03-02T14:21:00.000+02:00

С наступлением весны! Предлагаю почитать тематические статейки:
О биологическом подходе к поцелуям - http://scienceblogs.com/seed/2011/02/the_science_of_kissing.php
Об особенностях мозга влюблённого человека - http://blisstree.com/feel/the-brain-in-love-infographic/

Ряд новых идей о шизофрении

2011-02-20T21:45:00.004+02:00

Эта неделя оказалась урожайной на новости о генезе шизофрении.

Например, появились вот такие замечательные статьи:

GABAergic interneuron origin of schizophrenia pathophysiology. Nakazawa K, Zsiros V, Jiang Z, Nakao K, Kolata S, Zhang S, Belforte JE.

The viral theory of schizophrenia revisited: Abnormal placental gene expression and structural changes with lack of evidence for H1N1 viral presence in placentae or brains of exposed offspring from infected mice. Fatemi SH, Folsom TD, Rooney RJ, Mori S, Kornfield TE, Reutiman TJ, Kneeland RE, Liesch SB, Hua K, Hsu J, Patel DH.

Schizophrenia and tobacco smoking comorbidity: nAChR agonists in the treatment of schizophrenia-associated cognitive deficits. D'Souza MS, Markou A.

Contributions of the d-serine pathway to schizophrenia. Labrie V, Wong AH, Roder JC.

Behavioral and neurochemical consequences of cortical oxidative stress on parvalbumin-interneuron maturation in rodent models of schizophrenia. Powell SB, Sejnowski TJ, Behrens MM.

Adenosine hypothesis of schizophrenia - opportunities for pharmacotherapy. Boison D, Singer P, Shen HY, Feldon J, Yee BK.

Наслаждайтесь :)

2011-02-17T22:44:00.001+02:00

1001 посетитель :)

Кое-что новенькое о культивировании стволовых клеток

2011-02-08T14:28:00.000+02:00

Статейка о том, как взрослые стволовые клетки выращивали в специальных гидрогелях и подвергали всяческим физическим и химическим влияниям http://www.eurekalert.org/pub_releases/2010-11/uoc--bpa111610.php

О возможности культивирования плюрипотентных клеток в определённых условиях http://www.eurekalert.org/pub_releases/2010-12/uoia-ssp121510.php

Антипсихотики в США

2011-01-28T17:24:00.000+02:00

PRESCRIPTIONS for antipsychotic drugs have more than doubled in the US over the past 15 years, often given for conditions for which there is scant evidence they work.

Expensive antipsychotics were originally approved to treat schizophrenia. They are now also prescribed for conditions including anxiety disorders and dementia, even though the Food and Drug Administration has not approved these off-label uses. The side effects of such drugs can include diabetes, weight gain and an increased risk of heart disease.

Caleb Alexander at the University of Chicago and colleagues analysed the results of a survey of visits to doctors between 1995 and 2008. In the sample population, the prescriptions of antipsychotics went from 6.2 million in 1995 to 16.7 million in 2006 and fell to 14.3 million in 2008. Off-label prescriptions also doubled during this time (Pharmacoepidemiology and Drug Safety, DOI: 10.1002/pds.2082).

Alexander points to ways to combat the trend, such as reducing heavy drug marketing and raising awareness of off-label prescribing.
http://www.newscientist.com/article/mg20927952.500-antipsychotic-drug-prescriptions-triple-in-the-us.html?DCMP=OTC-rss&nsref=online-news

Эхинацея и гинкго - почти плацебо?

2010-12-25T23:37:00.000+02:00

Об эхинацеи читаем на http://blisstree.com/feel/echinacea-doesnt-cure-colds/ :
Trying to cure your pre-Christmas cold with all-natural Echinacea? A new study suggests that the so-called wonder herb, that’s been purported to prevent colds, may not be a miracle worker after all. It seems the herb, which is a wild flower found in the Midwestern plains, doesn’t have much impact on the duration or strength of colds.
The study followed more than 700 cold sufferers, and found that people who took Echinacea saw around a 10% reduction in the duration of their cold. That ends up being about seven to ten fewer hours, which is not, according to lead researcher Bruce Barrett, considered a medically significant decrease.
But Barrett advised that people who’ve experienced Echinacea’s healing properties should continue taking it, since the study isn’t absolutely conclusive. Besides, if you think it’s helping, than there’s no harm in trying, right?

О гинкго - на http://www.science20.com/news_articles/ginkgo_biloba_has_no_impact_cognitive_decline:
Ginkgo biloba, popularly consumed for its supposedly positive effect on memory, has no such effect, according to new research published in the December 23/30 issue of JAMA. In the study, older adults who used the herbal supplement for several years did not have a slower rate of cognitive decline compared to adults who received placebo .

"Ginkgo biloba is marketed widely and used with the hope of improving, preventing, or delaying cognitive impairment associated with aging and neurodegenerative disorders such as Alzheimer disease," the authors write. "Indeed, in the United States and particularly in Europe, G biloba is perhaps the most widely used herbal treatment consumed specifically to prevent age-related cognitive decline." However, evidence from large clinical trials regarding its effect on long-term cognitive functioning is lacking.

Beth E. Snitz, Ph.D., of the University of Pittsburgh, and colleagues analyzed outcomes from the Ginkgo Evaluation of Memory (GEM) study to determine if G biloba slowed the rate of cognitive decline in older adults who had normal cognition or mild cognitive impairment (MCI) at the beginning of the study.

The GEM study previously found that G biloba was not effective in reducing the incidence of Alzheimer dementia or dementia overall. The randomized, double-blind, placebo-controlled clinical trial included 3,069 community-dwelling participants, ages 72 to 96 years, who received a twice-daily dose of 120-mg extract of G biloba (n = 1,545) or identical-appearing placebo (n = 1,524). The study was conducted at six academic medical centers in the United States between 2000 and 2008, with a median (midpoint) follow-up of 6.1 years. Change in cognition was assessed by various tests and measures.

In this study, the largest randomized controlled trial of G biloba to report on outcomes to date, the researchers found no evidence for an effect of G biloba on global cognitive change and no evidence of effect on specific cognitive domains of memory, language, attention, visuospatial abilities and executive functions. They also found no evidence for differences in treatment effects by age, sex, race, education or baseline cognitive status (MCI vs. normal cognition).

"In sum, we find no evidence that G biloba slows the rate of cognitive decline in older adults. These findings are consistent with previous smaller studies examining prevention of decline and facilitation of cognitive performance and with the 2009 Cochrane review of G biloba for dementia and cognitive impairment."

Citation: Beth E. Snitz, Ellen S., Michelle C. Carlson, Alice M. Arnold, Diane G. Ives, Stephen R. Rapp, Judith Saxton, Oscar L. Lopez, Leslie O. Dunn, Kaycee M. Sink, Steven T. DeKosky, 'Ginkgo biloba for Preventing Cognitive Decline in Older Adults', JAMA, 2009, 302(24), 2663-2670

Ряд новых интересностей о допамине :)

2010-11-04T15:15:00.000+02:00

Dopamine model could play role in treating schizophrenia and drug addiction

In the brain, dopamine is involved in a number of processes that control the way we behave. If an action results in the substance being released, we are more likely to repeat the action. This applies to actions such as eating, sexual intercourse or winning a competition. However, the same also holds true when individuals take harmful narcotics. Scientists believe that mental illnesses such as schizophrenia can be linked to dopamine imbalances. Дальше на http://www.eurekalert.org/pub_releases/2010-10/uoc-dmc102010.php

Montreal, October 20, 2010 – Daily sleeping and eating patterns are critical to human well-being and health. Now, a new study from Concordia University has demonstrated how the brain chemical dopamine regulates these cycles by altering the activity of the "clock-protein" PER2. Published in the Journal of Neuroscience, these findings may have implications for individuals with Parkinson's Disease with disrupted 24-hour rhythms of activity and sleep. Дальше http://www.eurekalert.org/pub_releases/2010-10/cu-nro102010.php

SEATTLE, Wash. — October 18, 2010 — Researchers at the Allen Institute for Brain Science have found that the same genes have different activity patterns in the brain in individuals with different genetic backgrounds. These findings may help to explain individual differences in the effectiveness and side-effect profiles of therapeutic drugs and thus have implications for personalized medicine. The study is available in this week’s online early edition of the Proceedings of the National Academy of Sciences Дальше http://scienceblog.com/39433/gene-activity-in-the-brain-depends-on-genetic-background/?utm_source=feedburner&utm_medium=feed&utm_campaign=Feed%3A+scienceblogrssfeed+%28Science+Blog%29

Sensation seeking—the urge to do exciting things—has been linked to dopamine, a chemical that carries messages in your brain. For a new study published in Psychological Science, a journal of the Association for Psychological Science, scientists analyzed genes in the dopamine system and found a group of mutations that help predict whether someone is inclined toward sensation seeking. Дальше http://scienceblog.com/39121/a-thirst-for-excitement-is-hidden-in-your-genes/?utm_source=feedburner&utm_medium=feed&utm_campaign=Feed%3A+scienceblogrssfeed+%28Science+Blog%29

Glutamate and dopamine: Biological predictors of the transition to psychosis?

Philadelphia, PA, 30 September, 2010 - There is growing evidence that two neurotransmitters - dopamine and glutamate - are abnormal in people with psychotic illness, including schizophrenia. Among many other things, these chemicals play a role in cognitive functions, such as memory, learning, and problem-solving
A new study in Biological Psychiatry is now the first to examine the relationship between these two brain chemicals by measuring both in the same individuals. http://www.eurekalert.org/pub_releases/2010-09/e-gd093010.php

There’s a predictable narrative to a lot of discoveries in molecular biology. The story begins when a scientist discovers that Molecule X causes Phenomenon Y. Perhaps we’re talking about CREB and long-term memory, or serotonin and depression, or cholesterol and heart disease. At first, the data looks really solid – when the gene for Molecule X is knocked out of a mouse, Phenomenon Y disappears! And when patients take a drug that increases/reduces Molecule X, you get a change in Phenomenon Y! The causal relationship seems so simple.

And that’s when things start to get complicated. Time and time again, the neat relationship between Molecule X and Phenomenon Y disintegrates into a knot of feedback loops, enzymatic pathways, environmental interactions and regulatory genes. It’s not that Molecule X doesn’t matter – it’s that it doesn’t exist by itself. Instead, the Molecule exerts its effects by interacting with a byzantine list of other molecules, all of which can also influence the biological outcome. Read More http://www.wired.com/wiredscience/2010/08/sex-is-stressful-but-good-for-you/?utm_source=feedburner&utm_medium=feed&utm_campaign=Feed%3A+wiredscience+%28Blog+-+Wired+Science%29

Всем жениться!11111111

2010-09-10T12:35:00.000+03:00

Оказывается, женитьба - это не только приятно, но и очень полезно для здоровья. Вот вам и очередное доказательство. Читаем на http://scienceblog.com/37587/marriage-and-committed-romance-reduce-stress-related-hormone-production/?utm_source=feedburner&utm_medium=feed&utm_campaign=Feed%3A+scienceblogrssfeed+%28Science+Blog%29
Being married has often been associated with improving people’s health, but a new study suggests that having that long-term bond also alters hormones in a way that reduces stress.

Unmarried people in a committed, romantic relationship show the same reduced responses to stress as do married people, said Dario Maestripieri, Professor in Comparative Human Development at the University of Chicago and lead author of the study, published in the current issue of the journal Stress.

“These results suggest that single and unpaired individuals are more responsive to psychological stress than married individuals, a finding consistent with a growing body of evidence showing that marriage and social support can buffer against stress,” Maestripieri writes in the article, “Between- and Within-sex Variations in Hormonal Responses to Psychological Stress in a Large Sample of College Students.”

The team of researchers from the University of Chicago and Northwestern University studied 500 masters’ degree students at the University of Chicago Booth School of Business. About 40 percent of the men and 53 percent of the women were married or in relationships. The group included 348 men with a mean age of 29 and 153 women with a mean age of 27.

The students were asked to play a series of computer games that tested economic behaviors, and saliva samples were taken before and after to measure hormone levels and changes.

Each student was told that the test was a course requirement, and it would impact their future career placement. That made the test a potentially stressful experience that could affect levels of cortisol, known as the stress hormone.

The researchers found cortisol concentrations increased in all participants, but that females experienced a higher average increase than males. The exercise also decreased testosterone in male subjects, but not in females, a stress effect previously observed in humans and animals.

But a piece of personal information collected before the test provided another interesting difference within the subjects. “We found that unpaired individuals of both sexes had higher cortisol levels than married individuals,” Maestripieri said.

“Although marriage can be pretty stressful, it should make it easier for people to handle other stressors in their lives,” Maestripieri said. “What we found is that marriage has a dampening effect on cortisol responses to psychological stress, and that is very new.”

The study also found that single business school students also displayed higher baseline testosterone levels than their married or committed colleagues, a finding that mirrors previous human research as well as animal observations.
Maestripieri, who conducts the majority of his research on monkeys in Puerto Rico, said that in species of primates and birds where males assist females with rearing offspring show similar changes. In species that show monogamous pairing and shared rearing of offspring, testosterone levels in males drop as they engage in more fatherly behavior.

Maestripieri’s co-authors are Nicole Baran, a University of Chicago graduate who is now graduate student at Cornell University; Luigi Zingales, the Robert C. McCormack Professor of Entrepreneurship and Finance, University of Chicago Booth School of Business; and Paola Sapienza, Professor of Finance at Northwestern’s Kellogg School of Management.

Экстази как лекарство

2010-07-26T12:08:00.000+03:00

Два хороших поста о клинических испытаниях использования МДМА в качестве лекарства при посттравматическом синдроме. Очень совеитую почитать:

The media coverage of the MDMA Clinical trial result stinks

MDMA for PTSD: The first peer-reviewed clinical trial report

Когнитивные стимуляторы

2010-07-21T12:14:00.000+03:00

Обожаю эту девочку. У неё самые весёлые посты о самых интересных веществах. Очередная классная статья - http://scienceblogs.com/neurotopia/2010/07/prozac_ritalin_cognitive_enhan.php. О "улучшителях умственных способностей". Особое внимание уделено Прозаку и Риталину.

О процессах ингибирования в мозгу

2010-07-21T12:09:00.002+03:00

Отличная статья на http://www.science20.com/measuring_mind/inhibition_brain_more_simple_game.

Дым сигарет с ментолом

2010-07-21T11:58:00.002+03:00

Интересная инфа о влиянии ментола на "привыкабельность":
Cigarettes are just plain bad, as we all know by now.
But what about the ones that contain menthol? Are they worse?
A panel of experts is mulling menthol and trying to come up with some advice for the Food and Drug Administration on whether menthol should be forbidden as an additive.
Young people seem to gravitate to menthol-flavored cigarettes, and there's evidence menthol may make it harder for smokers trying to quit. It turns out that tiny amounts of menthol are even added as a subtle flavor-enhancer to many cigarettes that aren't labeled as menthol types.
Should menthol be banned —- just as Congress has banned other flavorings in cigarettes? Tobacco industry representatives say taste is the only thing that distinguishes menthol cigarettes from regular one — they aren't more harmful.
The use of menthol started accidentally, after mint crystals got left in a smoker’s tin of rolling tobacco overnight years ago.
The mint in menthol cigarettes may be natural or synthetic or a combination of both. Natural mint is crystalized from steamed distilled oil of the corn mint plant. Some 99 percent of the mint comes through in the smoke.
So how does the stuff get put on cigarettes? A bunch of ways. Sometimes, it's applied to the foil that is used to wrap the cigarettes. It's also sprayed on the tobacco, and even injected into the tobacco paper or the filter.
After a few weeks for aging, Michael Ogden of R.J. Reynolds says the effect was found to be the same pretty much regardless of method, according to smokers who volunteered for taste tests.
Ogden says testers describe the menthol smokes using terms like "cooling sensation, minty flavor and medicinal flavor."
Menthol can be misleading. "Menthol leads to the perception of an increase in nasal airway openness but in fact there is no actual change and (some studies have shown) minor constriction," Ogden says
R.J. Reynolds is the maker of Kool and Salem, once the leading menthol brands. Now, Newport dominates the market. It's from Lorillard, whose Scientific Director William True can sound like someone on Top Chef when he describes how the company assesses menthol.
True says the company taste experts sample packs the way some people test fine wine. They are sensitive to such things as a cigarette's early draw, the tobacco's papery or woody flavors, whether it's bitter or sweet, has a later draw or an after taste.
But it isn't menthol's taste that is under scrutiny at the hearing.
The scientific advisory panel wanted to know what properties in mentholated cigarettes attract young people, African Americans, and other ethnic groups. Newport is the top menthol cigarette for adolescents, according to the federal Substance Abuse & Mental Health Services Administration. The thinking is that menthol mellows the harshness of tobacco, which makes it easier for initiates to inhale and others to inhale more deeply.
True objected strenuously. "Absolutely not," he says. "Our product developers do not use menthol in any shape or form to cover, mask or minimize that harsh taste. The most significant items that impact the harsh taste of the cigarette are the tobacco blend, the moisture level of the blend and the filter ventilation."
The manufacturers of menthol cigarettes also deny that young people and ethnic groups are targeted with promotions. Industry representatives couldn't explain why menthol smokers tend to smoke fewer cigarettes, or why cancer rates are higher among African American smokers 70 percent of whom smoke menthol but smoke fewer cigarettes per day than non-menthol smokers.
"Internal studies do not indicate that menthol cigarettes are smoked any differently or more intensely than non menthol," according to Lorillard's William True. "These studies reinforce the overwhelming weight of epidemiology literature that menthol and non menthol convey similar risk of chronic disease."
Прочитано на http://www.npr.org/blogs/health/2010/07/16/128563062/menthol-the-mystery-ingredient-in-cigarettes

Зевота действительно заразна!

2010-07-21T11:50:00.000+03:00

Интересное видео и комментарии на http://scienceblogs.com/thoughtfulanimal/2010/07/yawn_yawn_yawn_yawn_yawn_conta.php

Новый способ флуоресцентного мечения белков

2010-06-03T11:52:00.000+03:00

Прочитала интересное на http://scienceblog.com/34611/mit-chemists-design-new-way-to-fluorescently-label-proteins/?utm_source=feedburner&utm_medium=feed&utm_campaign=Feed%3A+scienceblogrssfeed+%28Science+Blog%29

ScienceBlog.com

2010-06-03T11:51:00.002+03:00

ScienceBlog.com

Может ли метамфетамин улучшить память?

2010-06-03T11:47:00.000+03:00

Нет, скорее, он может ухудшить забывание, - пишут на http://www.eurekalert.org/pub_releases/2010-05/tcob-som052010.php
Snails on methamphetamine

How methamphetamine improves snail's memory

Crystal meth (methamphetamine) is a highly addictive drug that seduces victims by increasing self-esteem and sexual pleasure, and inducing euphoria. But once hooked, addicts find the habit hard to break. Barbara Sorg from Washington State University, USA, explains that amphetamines enhance memory. 'In addiction we talk about the "drug memory" as a "pathological memory". It is so potent as to not be easily forgotten,' she explains. As memory plays an important role in addiction, Sorg wondered whether it might be possible to find out more about the effects of meth on memory by looking at the effect it has on a humble mollusc: the pond snail Lymnaea stagnalis.
Lymnaea hold memories about when to breathe through their breathing tubes (pneumostomes) in a three neuron network, which is much simpler than the colossal circuits that hold our memories. Ken Lukowiak from University of Calgary, Canada, has been working on the mechanisms of memory formation in these snails for most of his career, so he and Sorg decided to team up to find out whether a dose of meth could improve the snails' memories in the way it does human memories. They publish their discovery that memories formed by snails under the influence of meth are harder to forget, which could help us to understand human addiction, on 28 May 2010 in The Journal of Experimental Biology at http://jeb.biologists.org/.
First Sorg and her students had to discover whether a dose of meth could affect the snails' breathing behaviour. According to Lukowiak, the snails breathe through their skins when oxygen levels are high, but when oxygen levels drop the snails extend their pneumostomes above the water's surface to supplement the supply. As the drug easily crosses the snail's skin, the team immersed the snails in de-oxygenated pond water spiked with meth, and watched to see how it affected their breathing. The snails stopped raising their pnemostomes at 1 and 3.3·μmol·l-1 meth, so having found a dose that altered the snail's behaviour, the team began testing its effects on the mollusc's long term memory.
The team trained the snails to remember to keep their pneumostomes closed when oxygen levels were low by poking them with a stick every time they tried to open their pneumostomes. Giving the snails two training sessions separated by an hour, the team knew that the molluscs would hold the memory for over 24·h, but what would happen if they trained the snails in meth-laced water?
Testing the snails in de-oxygenated pond water 24 hours later, the team were surprised to see that the snails seemed to have no recollection of their training, popping their pneumostomes above the water's surface. Maybe meth did not affect the snails' memories. But then Lukowiak remembered: 'If you put snails in a novel context even though they have memory they respond as if they don't have memory,' he says. Without meth in the water, the snails were ignoring their memory. However, when the team reintroduced meth to the test water, the snails suddenly remembered to keep their pneumostomes closed. This could explain why it's so hard for human addicts to kick the habit when returning to old haunts that trigger the addiction memory.

Next the team wondered whether meth could improve the snails' memories. First they immersed the snails in meth-laced pond water, then they moved them into regular de-oxygented pond water and gave them a training session that the snails should only recall for a few hours. In theory the snails should have forgotten their training 24 hours later, but would the meth improve the snails' memories so they remembered to keep their pneomostomes closed a day later? It did. A dose of meth prior to training had improved the snails' memories, allowing them to recall a lesson that they should have already forgotten. And when the team tested whether they could mask the meth memory with another memory, they found that the meth memory was much stronger and harder to mask.

So memories formed under the influence of meth seem to be harder to forget, possibly because the drug disrupts the mechanisms for forgetting, and could help us to understand how amphetamines enhance memory in humans.

###

IF REPORTING ON THIS STORY, PLEASE MENTION THE JOURNAL OF EXPERIMENTAL BIOLOGY AS THE SOURCE AND, IF REPORTING ONLINE, PLEASE CARRY A LINK TO: http://jeb.biologists.org/

REFERENCE: Kennedy, C. D., Houmes, S. W., Wyrick, K. L., Kammerzell, S. M., Lukowiak, K. and Sorg, B. A. (2010). Methamphetamine enhances memory of operantly conditioned respiratory behavior in the snail Lymnaea stagnalis. J. Exp. Biol. 213, 2055-2065.

This article is posted on this site to give advance access to other authorised media who may wish to report on this story. Full attribution is required, and if reporting online a link to jeb.biologists.com is also required. The story posted here is COPYRIGHTED. Therefore advance permission is required before any and every reproduction of each article in full. PLEASE CONTACT permissions@biologists.com

THIS ARTICLE APPEARS IN THE JOURNAL OF EXPERIMENTAL BIOLOGY ON: 28 May 2010. EMBARGOED UNTIL THURSDAY, 27 May 2010, 17:00 HRS EST

Синестезия. Подборка хороших материалов

2010-05-10T23:30:00.000+03:00

The Clock Is Off: Bipolar Disorder and Circadian Rhythm | ScienceBlog.com

2010-05-10T23:21:00.000+03:00

Здоровская статья про маниакально-депрессивное расстройство и циркадные ритмы: The Clock Is Off: Bipolar Disorder and Circadian Rhythm | ScienceBlog.com

Эндометриальные стволовые клетки и допамин

2010-05-10T23:19:00.000+03:00

Информация о возможных способах лечения болезни Паркинсона стволовыми клетками описан на http://www.eurekalert.org/pub_releases/2010-05/nioc-esc050610.php

Endometrial stem cells restore brain dopamine levels

Mouse study may lead to new therapies for Parkinson's Disease

Endometrial stem cells injected into the brains of mice with a laboratory-induced form of Parkinson's disease appeared to take over the functioning of brain cells eradicated by the disease.
The finding raises the possibility that women with Parkinson's disease could serve as their own stem cell donors. Similarly, because endometrial stem cells are readily available and easy to collect, banks of endometrial stem cells could be stored for men and women with Parkinson's disease.
"These early results are encouraging," said Alan E. Guttmacher, M.D., acting director of the Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD), the NIH Institute that funded the study. "Endometrial stem cells are widely available, easy to access and appear to take on the characteristics of nervous system tissue readily."
Parkinson's disease results from a loss of brain cells that produce the chemical messenger dopamine, which aids the transmission of brain signals that coordinate movement.
This is the first time that researchers have successfully transplanted stem cells derived from the endometrium, or the lining of the uterus, into another kind of tissue (the brain) and shown that these cells can develop into cells with the properties of that tissue.
The findings appear online in the Journal of Cellular and Molecular Medicine.
The study's authors were Erin F. Wolff, Xiao-Bing Gao, Katherine V. Yao, Zane B. Andrews, Hongling Du, John D. Elsworth and Hugh S. Taylor, all of Yale University School of Medicine.
Stem cells retain the capacity to develop into a range of cell types with specific functions. They have been derived from umbilical cord blood, bone marrow, embryonic tissue, and from other tissues with an inherent capacity to develop into specialized cells. Because of their ability to divide into new cells and to develop into a variety of cell types, stem cells are considered promising for the treatment of many diseases in which the body's own cells are damaged or depleted.
In the current study, the researchers generated stem cells using endometrial tissue obtained from nine women who did not have Parkinson's disease and verified that, in laboratory cultures, the unspecialized endometrial stem cells could be transformed into dopamine-producing nerve cells like those in the brain.
The researchers also demonstrated that, when injected directly into the brains of mice with a Parkinson's-like condition, endometrial stem cells would develop into dopamine-producing cells.
Unspecialized stem cells from the endometrial tissue were injected into mouse striatum, a structure deep in the brain that plays a vital role in coordinating balance and movement. When the researchers examined the animals' striata five weeks later, they found that the stem cells had populated the striatum and an adjacent brain region, the substantia nigra. The substantia nigra produces abnormally low levels of dopamine in human Parkinson's disease and the mouse version of the disorder. The researchers confirmed that the stem cells that had migrated to the substantia nigra became dopamine-producing nerve cells and that the animals' dopamine levels were partially restored.
The study did not examine the longer-term effects of the stem cell transplants or evaluate any changes in the ability of the mice to move. The researchers noted that additional research would need to be conducted to evaluate the safety and efficacy of the technique before it could be approved for human use.
According to the researchers, stem cells derived from endometrial tissue appear to be less likely to be rejected than are stem cells from other sources. As expected, the stem cells generated dopamine producing cells when transplanted into the brains of mice with compromised immune systems. However, the transplants also successfully gave rise to dopamine producing cells in the brains of mice with normal immune systems.
According to Dr. Taylor, because women could provide their own donor tissue, there would be no concern that their bodies would reject the implants. Moreover, because endometrial tissue is widely available, banks of stem cells could be established. The stem cells could be matched by tissue type to male recipients with Parkinson's to minimize the chances of rejection.
In addition, Dr. Taylor added that endometrial stem cells might prove to be easier to obtain and easier to use than many other types of stem cells. With each menstrual cycle, women generate new endometrial tissue every month, so the stem cells are readily available. Even after menopause, women taking estrogen supplements are capable of generating new endometrial tissue. Because doctors can gather samples of the endometrial lining in a simple office procedure, it is also easier to collect than other types of adult stem cells, such as those from bone marrow, which must be collected surgically.
"Endometrial tissue is probably the most readily available, safest, most easily attainable source of stem cells that is currently available. We hope the cells we derived are the first of many types that will be used to treat a variety of diseases," said senior author Hugh S. Taylor, M.D., of Yale University. "I think this is just the tip of the iceberg for what we will be able to do with these cells."

###

The NICHD sponsors research on development, before and after birth; maternal, child, and family health; reproductive biology and population issues; and medical rehabilitation. For more information, visit the Institute's Web site at http://www.nichd.nih.gov/.
The National Institutes of Health (NIH) — The Nation's Medical Research Agency — includes 27 Institutes and Centers and is a component of the U. S. Department of Health and Human Services. It is the primary federal agency for conducting and supporting basic, clinical, and translational medical research, and it investigates the causes, treatments, and cures for both common and rare diseases. For more information about NIH and its programs, visit http://www.nih.gov.

Солярий = наркотик?

2010-05-05T01:37:00.000+03:00

Очень классное исследование показывает, что между посещением соляриев и склонностью к зависимостям, в том числе и наркотической, есть прямая связь. Материал с http://blisstree.com/feel/white-hot-addiction-skin-cancer-and-the-tanning-bed/:
Even though the 80s are long gone, tanning bed addiction is alive and well, a recent study suggests. Fake rays are like crack for some UV bed frequenters.
Researchers decided to examine a link from tanning to substance abuse and depression in college students, and found that among 229 of them, 90 qualified as “addicted to indoor tanning.” And those addicts reported greater symptoms of anxiety and more drug and alcohol use.
Heavy tanners actually missed going outside to catch the sun’s natural rays. More than 3/4 of the most frequent tanners tried to cut down on indoor tanning sessions, but had been unable to, according to The New York Times.
How can a person be addicted to a neon blue lit coffin? As with exercise, research suggests that UV rays may release endorphins. And even though everyone in the study knew the health risks involved with tanning, it seems that – for some people – achieving that golden goddess glow might be worth a little skin cancer.

Новые новости :)

2010-05-05T01:34:00.000+03:00

Очень интересные материалы по связи сна и лишнего веса: http://www.scientificblogging.com/news_articles/teens_who_sleep_less_gain_more_weight_study_finds
О новом антикокаиновом препарате: http://www.scientificblogging.com/news_articles/coce_therapy_cocaine_toxicity
Хороший пост об эффективности антидепрессантов: http://blisstree.com/feel/mental-health-are-antidepressants-all-in-your-head/

Сочувствие и жестокость связаны на уровне мозга

2010-04-16T16:57:00.002+03:00

Интересные нововсти на http://www.biologynews.net/archives/2010/04/09/empathy_and_violence_have_similar_circuits_in_the_brain.html
"Just as our species could be considered the most violent, since we are capable of serial killings, genocide and other atrocities, we are also the most empathetic species, which would seem to be the other side of the coin", Luis Moya Albiol, lead author of the study and a researcher at the UV, tells SINC.

This study, published in the most recent issue of the Revista de Neurología, concludes that the prefrontal and temporal cortex, the amygdala and other features of the limbic system (such as insulin and the cingulated cortex) play "a fundamental role in all situations in which empathy appears".

Moya Albiol says these parts of the brain overlap "in a surprising way" with those that regulate aggression and violence. As a result, the scientific team argues that the cerebral circuits – for both empathy and violence – could be "partially similar".

"We all know that encouraging empathy has an inhibiting effect on violence, but this may not only be a social question but also a biological one – stimulation of these neuronal circuits in one direction reduces their activity in the other", the researcher adds.

This means it is difficult for a "more empathetic" brain to behave in a violent way, at least on a regular basis. "Educating people to be empathetic could be an education for peace, bringing about a reduction in conflict and belligerent acts", the researcher concludes.

Techniques for measuring the human brain "in vivo", such as functional magnetic resonance imaging, are making it possible to find out more about the structures of the brain that regulate behaviour and psychological processes such as empathy.

Source : FECYT - Spanish Foundation for Science and Technology

Новая система измерения параметров клеток

2010-04-16T16:55:00.002+03:00

Читаю на http://www.biologynews.net/archives/2010/04/12/mit_new_cell_measurement_system.html
Using a sensor that weighs cells with unprecedented precision, MIT and Harvard researchers have measured the rate at which single cells accumulate mass — a feat that could shed light on how cells control their growth and why those controls fail in cancer cells.

The research team, led by Scott Manalis, MIT associate professor of biological engineering, revealed that individual cells vary greatly in their growth rates, and also found evidence that cells grow exponentially (meaning they grow faster as they become larger).

The new measurement system, reported in the April 11 edition of the journal Nature Methods, is the first technique that can measure cells' mass as they grow over a period of time, ranging from five to 30 minutes. Previous methods for measuring cell growth rates have focused on volume or length measurements, and have not yet exhibited the necessary precision for revealing single cell growth models.

How they did it: The cell-mass sensor, which Manalis first demonstrated in 2007, consists of a fluid-filled microchannel etched in a tiny silicon slab that vibrates inside a vacuum. As cells flow through the channel, one at a time, their mass slightly alters the slab's vibration frequency. The mass of the cell can be calculated from that change in frequency, with a resolution as low as a femtogram (10-15 grams).

Michel Godin, a former postdoctoral associate in Manalis' lab and co-lead author of the paper, developed a way to trap a cell within the microchannel by precisely coordinating the flow direction. That enables the researchers to repeatedly pass a single cell through the channel every second or so, measuring it each time it moves through.

The researchers studied four types of cells: two strains of bacteria (E. coli and B. subtilis), a strain of yeast and mammalian lymphoblasts (precursors to white blood cells). They showed that B. subtilis cells appear to grow exponentially, but they did not obtain conclusive evidence for E. coli. That's because there is so much variation between individual cell growth rates in E. coli, even for cells of similar mass, says Francisco Delgado, a grad student in Manalis' lab and co-lead author of the paper.

If cells do grow exponentially, it means there must be some kind of mechanism to control that growth. Otherwise, when cells divide into two slightly different-sized daughter cells, as they often do, the larger cell in each generation would always grow faster than the smaller cell, leading to inconsistent cell sizes.

"If there were no control over the process, the variation in cell size would be all over the map," says Marc Kirschner, professor of systems biology at Harvard Medical School and an author of the paper. However, biologists don't know yet how that control mechanism might work.

Next steps: In their current studies, the researchers are tagging proteins inside the cell with fluorescent molecules that reveal what stage of the cell cycle the cell is in, allowing them to correlate cell size with cell cycle position. They are also working on a way to add chemicals such as nutrients, antibiotics and cancer drugs to the fluid inside the microchannel, so they can study how those substances affect growth rates.

Source : Massachusetts Institute of Technology

У двух психов вероятность родить третьего повышается

2010-03-24T17:20:00.000+02:00

Мда... Читаем на http://www.eurekalert.org/pub_releases/2010-03/jaaj-oot022510.php:
Offspring of 2 psychiatric patients have increased risk of developing mental disorders

Offspring of two parents with schizophrenia or bipolar disorder appear more likely to develop the same illness or another psychiatric condition than those with only one parent with psychiatric illness, according to a report in the March issue of Archives of General Psychiatry, one of the JAMA/Archives journals.

The offspring of two parents with psychiatric illness represent an extremely high-risk group, according to background information in the article. Studying these children permits researchers to assess the risk associated with two sources of genetic predisposition to mental disorders. "Such risks will be of use to genetic counselors to inform personal decisions with regard to marriage, family formation, adoption and health insurance planning," the authors write.

Irving I. Gottesman, Ph.D., Hon.F.R.C.Psych., of the University of Minnesota Medical School, Minneapolis, and colleagues studied a population-based cohort of 2.7 million individuals born in Denmark. The researchers matched records in a general registry of the population with a database of psychiatric admissions. They identified individuals whose parents had both been admitted to psychiatric facilities for schizophrenia and bipolar disorder, and compared the rate of psychiatric admissions for these individuals to those of offspring with one or no parents admitted to psychiatric facilities.

Rates of schizophrenia were highest among offspring of two parents with schizophrenia. Of the 196 couples who both had schizophrenia, 27.3 percent of their 270 children were admitted to a psychiatric facility, increasing to 39.2 percent when schizophrenia-related disorders were included. This compared with a rate of 7 percent among 13,878 offspring of 8,006 couples in which one parent had schizophrenia and 0.86 percent in 2.2 million offspring of 1 million couples in which neither parent was admitted for schizophrenia.

Similarly, the risk of bipolar disorder was 24.9 percent in 146 offspring of 83 parent couples who were both admitted for bipolar disorder (increasing to 36 percent when unipolar depressive disorder was also included). This compared to a risk of 4.4 percent among 23,152 offspring of 11,995 couples with only one parent ever admitted for bipolar disorder and 0.48 percent in 2.2 million children of 1 million couples with neither parent ever admitted.

When one parent had bipolar disorder and the other had schizophrenia, offspring had a 15.6 percent risk of schizophrenia and an 11.7 percent risk of bipolar disorder.

The risks in this population "are of such a magnitude that they command clinical and national public health attention in countries with health care roughly similar to Denmark's," the authors write.

"It is important to keep in mind that the yields from genetic epidemiology and the strategies implemented are applicable to groups of people, not to the individuals themselves," they conclude. "However, by joining advances in molecular genetics that are adapted for use in epidemiological genetic screening, our kinds of data with the risk groups described might lead to a large and rapid step forward in the understanding of the etiologies of major mental disorders."

О вреде кокаина и метамфетамина

2010-03-24T17:18:00.000+02:00

2 новых статьи:
http://www.eurekalert.org/pub_releases/2010-03/uoc--sdi031710.php - о том, что при повышенной температуре воздуха, риск негативного влияния кокаина на организм увеличивается

http://www.eurekalert.org/pub_releases/2010-03/sfn-bai031210.php - о страшных последствиях употребления метамфетамина матерями.

"Заразительное" поведение в группах

2010-03-24T16:56:00.000+02:00

Интересная работа, о которой я прочитала на http://www.eurekalert.org/pub_releases/2010-03/uoc--sdi031710.php
Sleep deprivation influences drug use in teens' social networks

More than 1 behavior can spread simultaneously across a social network

Recent studies have shown that behaviors such as happiness, obesity, smoking and altruism are "contagious" within adult social networks. In other words, your behavior not only influences your friends, but also their friends and so on. Researchers at the University of California, San Diego and Harvard University have taken this a step farther and found that the spread of one behavior in social networks – in this case, poor sleep patterns – influences the spread of another behavior, adolescent drug use.

The study, led by Sara C. Mednick, PhD, assistant professor of psychiatry at the University of California, San Diego School of Medicine and the VA San Diego Healthcare System, will be published March 19 in PLoS One.

"This is our first investigation of the spread of illegal drug use in social networks," said Mednick. "We believe it is also the first study in any age population on the spread of sleep behaviors through social networks."

Using social network data from the National Longitudinal Study of Adolescent Health, Mednick and her colleagues James H. Fowler, UCSD Department of Political Science and Nicholas A. Christakis, Harvard Medical School, mapped the social networks of 8,349 adolescents in grades 7 through 12. They found clusters of poor sleep behavior and marijuana use that extended up to four degrees of separation (to one's friends' friends' friends' friends) in the social network.

Another novel network effect that they discovered was that teens who are at the center of the network are at greater risk of poor sleep, which in turn means they are more likely to use marijuana – putting them at the crossroads of two behaviors increases a teenager's vulnerability.

Contrary to the general assumption that drug use has a negative effect on sleep, the researchers also found that sleep loss is likely to drive adolescents to use drugs – the less they sleep the more likely their friends are to sleep poorly and use marijuana.

"Our behaviors are connected to each other and we need to start thinking about how one behavior affects our lives on many levels," said Mednick. "Therefore, when parents, schools and law enforcement want to look for ways to influence one outcome, such as drug use, our research suggests that targeting another behavior, like sleep, may have a positive influence. They should be promoting healthy sleep habits that eliminate behaviors which interfere with sleep: take the TV out of the child's bedroom, limit computer and phone usage to daytime and early evening hours, and promote napping."

О хронических "мигренозниках"

2010-02-25T16:23:00.000+02:00

Статья о страдающих хроническими и спорадическими мигренями, на http://www.eurekalert.org/pub_releases/2010-02/bmj-cms021610.php

Chronic migraineurs sicker, poorer and more depressed than episodic migraineurs

Sociodemographic and comorbidity profiles of chronic migraine and episodic migraine sufferers

Chronic migraine sufferers tend to be in poorer general health, less well off, and more depressed than those with episodic migraine, reveals research published ahead of print in the Journal of Neurology Neurosurgery and Psychiatry.

The findings are based on almost 12,000 adults with episodic - a severe headache on up to 14 days of the month - or chronic migraine - headache on 15 or more days of the month.

All participants were already part of the American Migraine Prevalence and Prevention (AMPP) study, a long term US population based study of 24,000 headache sufferers, which has included regular surveys since 2004.

The research team analysed data collected in the 2005 survey on socioeconomic circumstances and other health problems.

The results showed that those with chronic migraine had significantly lower levels of household income, were less likely to be working full time, and were almost twice as likely to have a job related disability than their peers with episodic migraine.

They were twice as likely to be depressed, anxious, and experiencing chronic pain. And they were significantly more likely to have other serious health problems.

These included asthma, bronchitis, and chronic obstructive pulmonary disease (COPD), high blood pressure, diabetes, high cholesterol and obesity. They were also around 40% more likely to have heart disease and angina and 70% more likely to have had a stroke.

The authors point out that chronic migraine "can be an especially disabling and burdensome condition."

Previous research indicates that chronic migraineurs have a relatively high level of sick leave, reduced productivity, and poorer quality of family life than episodic migraineurs.

It also suggests that few are diagnosed correctly and that only around one in three are treated appropriately.

The differences unearthed between the two groups in the present study might reflect differences in biological risk factors and provide valuable clues as to how episodic migraine progresses to chronic migraine, suggest the authors

Три новых статьи об эффектах наркотических веществ

2010-02-25T16:19:00.001+02:00

http://scienceblogs.com/drugmonkey/2010/02/synthetic_marijuana_k2_spice_j.php - о синтетической марихуане
http://www.scientificblogging.com/news_articles/does_recreational_drug_use_damage_memory - о проблемах с памятью у употребляющих психотропные вещества
http://scienceblogs.com/drugmonkey/2010/02/as_many_dependent_on_cannabis.php - о связи курения марихуаны и употребления героина

Отличный пост о повреждениях ДНК и стволовых клетках

2010-02-25T16:15:00.000+02:00

Две мои любимейшие темы в одном чудесном посте. Автор - Ed Yong
All of our cells are staffed by armies of executioners. They are usually restrained but when unleashed, they can set off a fatal chain reaction that kills the cell. This suicide squad does away with billions of cells every day. It helps to balance the production of new cells with the loss of old ones, to sculpt growing tissues and to destroy potential cancer cells.

But a new study suggests that the executioners aren't always lethal. In fact, they're essential for life. Through the unorthodox method of damaging our DNA, they can actually activate important genes. This technique for switching genes on is new to science but it's apparently vital for allowing some types of stem cell to produce new types of tissue.
Stem cells are bundles of untapped potential, with the ability to produce hundreds of specialist cells across the body. This process is called differentiation. Its details vary depending on which type of cell is being produced, but scientists have recently found that some aspects are apparently common to all tissues, be they muscle, blood or bone. Surprisingly, one of these is the recruitment of executioner proteins - caspases.
Caspases cut up other proteins and in doing so, some of them produce yet more caspases. The result is a growing army of death, hacking and slashing its way through the cell. But one of these killers - caspase-3 - is a necessary part of differentiation. Get rid of it and, suddenly, stem cells can't produce their specialised daughters. Now, thanks to Brian Larsen from the Sprott Centre for Stem Cell Research, we know why.
Caspase-3 activates a protein called CAD (or caspase-activated DNase in full) by slicing apart other proteins holding it at bay. Once released, CAD lives up to its villainous acronym. It pairs up with an identical twin to create a molecule that looks and acts like a pair of scissors. The pair can cut DNA, cleaving the famous double helix in two. These sorts of cuts are normally very bad news for a cell. If they aren't repaired quickly and accurately, the consequences can include death or cancer.
But Larsen has found that stem cells deliberately break their own DNA by recruiting caspase-3 and CAD. This act of self-harm switches on important genes that are needed for differentiation; without it, the generalist cells can't specialise. This is an entirely new way of activating genes and it appears to be both important and widespread.
Larsen studied stem-like cells called myoblasts, which give rise to various types of muscle cells. As the myoblasts differentiated, Larsen watched for signs of shattered DNA using a clever test called the 'comet assay'. The technique involves puncturing a cell and placing it in an electric field. The field drives DNA through the punctured cell but only if it has already been broken into small pieces. If it has, it appears as a streak outside the cell, rather like the tail of a comet.
Sure enough, the comet test revealed that differentiating cells suffer from significant amounts of damaged DNA. Thankfully, the injuries are only temporary and the cells soon marshal their repairmen to fix the breaks.
The myoblasts need these breaks to produce muscle fibres and to create the breaks, they rely on caspase-3 and its ability to activate CAD. Larsen managed to block the development of muscle fibres by dousing myoblasts with chemicals that neutralise caspase-3. The same thing happened if he used cells with mutant versions of CAD, which couldn't be activated. In both cases, the cells failed to show any signs of broken DNA.
CAD targets a gene called p21 that's absolutely necessary for the development of muscle and plenty of other tissues. Larsen found that CAD cuts p21's 'promoter', a stretch of DNA lying next to the gene that's responsible for switching it on. Somehow, these cuts activate the gene. It's still not clear how this works, but Larsen has some ideas. The cuts could change how the surrounding DNA is packaged, exposing the p21 gene and making it easier to 'read'. Alternatively, the cuts could remove chemical 'marks' attached to the DNA that would otherwise silence it.
Damaging your own DNA may seem like a rather extreme tactic for a cell to take but it's not unheard of as a deliberate ploy. Whenever we face new infections, our body generates antibodies by breaking the DNA of special genes, stitching them back together in new combinations. That's a very controlled process, but so is the damage that leads to differentiation. It's a careful surgical strike, rather than a shock and awe campaign.
During differentiation, Larsen found that DNA breaks are actually few and far between. They appear to be carefully orchestrated so that the entire genome doesn't become a shattered mess. This precision is even more remarkable when you consider that CAD cuts DNA indiscriminately, with little care for specific sequences. Larsen thinks that CAD is constrained by the way the DNA is packaged, so that only places that are meant to be cut are exposed for slicing and dicing. Only further experiments will tell if he is right.

Reference: Larsen et al. 2010. Caspase 3/caspase-activated DNase promote cell differentiation by inducing DNA strand breaks. http://dx.doi.org/10.1073/pnas.0913089107

Статья с http://scienceblogs.com/notrocketscience/2010/02/our_cells_produce_new_tissues_by_recruiting_executioners_to.php

Суицидальная нетрадиционность...

2010-02-06T22:03:00.002+02:00

Оказывается, самоидентификация геев, лесбиянок и бисексуалов увеличивает риск суицида. Читаем на http://www.eurekalert.org/pub_releases/2010-02/jgh-yws020510.php
Mental health professionals have long-known that gay, lesbian and bisexual (GLB) teens face significantly elevated risks of mental health problems, including suicidal thoughts and suicidal attempts. However, a group of McGill University researchers in Montreal has now come to the conclusion that self-identity is the crucial risk-factor, rather than actual sexual behaviours. Their results were published in February in the Journal of the American Academy of Child & Adolescent Psychiatry.
The researchers administered a detailed, anonymous questionnaire to nearly 1,900 students in 14 Montreal-area high schools, and found that those teens who self-identified as gay, lesbian or bisexual, or who were unsure of their sexual identity, were indeed at higher risk for suicidal ideation and attempts. However, teens who had same-sex attractions or sexual experiences – but thought of themselves as heterosexual – were at no greater risk than the population at large. Perhaps surprisingly, but consistent with previous studies, the majority of teens with same-sex sexual attraction or experience considered themselves to be heterosexual.
"This is the first study that has separated sexual identity from sexual attractions and behaviours in looking at risk for poor mental health outcomes," said corresponding author Dr. Brett Thombs, of the Lady Davis Institute for Medical Research (LDI) at the Jewish General Hospital.
"It's important to realize that a large proportion of people who have sex with or are attracted to people of the same sex do not identify themselves as gay, lesbian or bisexual. They consider themselves heterosexual." added co-author Dr. Richard Montoro of the McGill University Health Centre (MUHC). "Those students were not at all at risk of worse mental health outcomes."
"The main message is that it's the interface between individuals and society that causes students who identify as gay, lesbian, or bisexual the most distress," said study first author Yue Zhao, a McGill University graduate student working with Dr. Thombs.. "Sexual orientation has three different components. The first is identity, which is dependent on the society in which one lives; the second is attraction or fantasy; and the third is behaviour. Previous studies have not addressed which of those components may explain why GLB youth are at risk."
"What this all means is that clinicians need to look not just at individuals and their sexuality, they really need to assess the environment they are coming from and how they see themselves within it," said study co-author Dr. Karine Igartua. Igartua and Montoro are co-directors of the McGill University Sexual Identity Centre (MUSIC), the first gay and lesbian mental health centre in Canada.
"Our findings also clearly suggest that further study of the link between anti-gay sentiment and suicidality need to be undertaken," added Thombs.

Новости о ферментах репарации ДНК

2010-02-02T17:28:00.000+02:00

Читаем на http://www.biologynews.net/archives/2010/01/28/researchers_find_new_way_to_study_how_enzymes_repair_dna_damage.html
Researchers at Ohio State University have found a new way to study how enzymes move as they repair DNA sun damage -- and that discovery could one day lead to new therapies for healing sunburned skin.
Ultraviolet (UV) light damages skin by causing chemical bonds to form in the wrong places along the DNA molecules in our cells. Normally, other, even smaller molecules called photolyases heal the damage. Sunburn happens when the DNA is too damaged to repair, and cells die.
Photolyases have always been hard to study, in part because they work in tiny fractions of a second. In this week's online edition of the Proceedings of the National Academy of Sciences, Ohio State physicist and chemist Dongping Zhong and his colleagues describe how they used ultra-fast pulses of laser light to spy on a photolyase while it was healing a strand of DNA.
This is the first time that anyone has observed this enzyme motion without first attaching a fluorescent molecule to the photolyase, which disturbs its movements. They were able to see the enzyme's motion to help the healing process as it happens in nature.
"Now that we have accurately mapped the motions of a photolyase at the site of DNA repair, we can much better understand DNA repair at the atomic scale, and we can reveal the entire repair process with unprecedented detail," said Zhong, the Robert Smith Associate Professor of Physics, and associate professor in the departments of chemistry and biochemistry at Ohio State.
Such small motions are very hard to study. Typically, researchers deal with the problem by attaching tiny bits of fluorescent molecules to the enzymes they are trying to study. But adding an extra molecule to an enzyme such as photolyase could change how it moves.
"Once you tag it, you can't be sure that the motions you detect are the true motions of the molecule as it would normally function," Zhong explained.
So instead of using tags, he and his team took laser "snapshots" of a single photolyase in action in the laboratory. They mapped the shape and position of the photolyase molecule as it broke up the harmful chemical bonds in DNA caused by UV light. The whole reaction lasted only a few billionths of a second.
In nature, DNA avoids damage by converting UV rays into heat. Sunscreen lotions protect us by reflecting sunlight away from the skin, and also by dissipating UV as heat.
Sunburn happens when the DNA absorbs the UV energy instead of converting it to heat. This is due in part to the random position of the DNA molecule within our cells when the UV hits it. When the UV energy is absorbed, it triggers chemical reactions that form lesions -- errant chemical bonds -- along the DNA strand.
If photolyases are unable to completely repair the lesions, the DNA can't replicate properly. Badly damaged cells simply die — that's what gives sunburn its sting. Scientists also believe that chronic sun damage creates mutations that lead to diseases such as skin cancer.
The work in Zhong's lab is fundamental to the understanding of how those molecules interact. Other researchers could use this information to design drugs to heal sun damage.
"Of course, the ultimate goal of studying DNA repair is to help design artificial systems to mimic it," he said.

Source : Ohio State University

О некоторых особенностях амбидекстров

2010-01-25T18:00:00.000+02:00

Интересные новости на http://www.scienceblog.com/cms/mixed-handed-children-more-likely-have-mental-health-language-and-scholastic-problems.html. Вообще-то странно. Мне всегда казалось, что люди с в равной степени развитыми полушариями мозга, должны быть более успешны... А оказывается, не всегда:
Children who are mixed-handed, or ambidextrous, are more likely to have mental health, language and scholastic problems in childhood than right- or left-handed children, according to a new study published today in the journal Pediatrics.
The researchers behind the study, from Imperial College London and other European institutions, suggest that their findings may help teachers and health professionals to identify children who are particularly at risk of developing certain problems.
Around one in every 100 people is mixed-handed. The study looked at nearly 8,000 children, 87 of whom were mixed-handed, and found that mixed-handed 7 and 8-year old children were twice as likely as their right-handed peers to have difficulties with language and to perform poorly in school.
When they reached 15 or 16, mixed-handed adolescents were also at twice the risk of having symptoms of attention deficit/hyperactivity disorder (ADHD). They were also likely to have more severe symptoms of ADHD than their right-handed counterparts. It is estimated that ADHD affects between 3 to 9 percent of school-aged children and young people.
The adolescents also reported having greater difficulties with language than those who were left- or right-handed. This is in line with earlier studies that have linked mixed-handedness with dyslexia.
Little is known about what makes people mixed-handed but it is known that handedness is linked to the hemispheres in the brain. Previous research has shown that where a person's natural preference is for using their right hand, the left hemisphere of their brain is more dominant.
Some researchers have suggested that mixed-handedness indicates that the pattern of dominance is not that which is typically seen in most people, i.e. it is less clear that one hemisphere is dominant over the other. One study has suggested that ADHD is linked to having a weaker function in the right hemisphere of the brain, which could help explain why some of the mixed-handed students in today's study had symptoms of ADHD.
Dr Alina Rodriguez, the lead researcher on the study from the School of Public Health at Imperial College London, said: "Mixed-handedness is intriguing -- we don't know why some people prefer to make use of both hands when most people use only one. Our study is interesting because it suggests that some children who are mixed handed experience greater difficulties in school than their left- and right-handed friends. We think that there are differences in the brain that might explain these difficulties, but there needs to be more research.
"Because mixed-handedness is such a rare condition, the number of mixed-handed children we were able to study was relatively small, but our results are statistically and clinically significant. That said, our results should not be taken to mean that all children who are mixed-handed will have problems at school or develop ADHD. We found that mixed-handed children and adolescents were at a higher risk of having certain problems, but we'd like to stress that most of the mixed-handed children we followed didn't have any of these difficulties," added Dr Rodriguez.
To study the effects of mixed-handedness, Dr Rodriguez and her colleagues looked at prospective data from a cohort of 7,871 children from Northern Finland. Using questionnaires, the researchers assessed the children when they reached 7 to 8 years of age and again at 15 to 16 years of age.
When the children were aged 8, the researchers asked parents and teachers to assess their linguistic abilities, scholastic performance and behaviour. The teachers reported whether children had difficulties in reading, writing or mathematics and rated the children's academic performance as below average, average or above average.
The adolescents' parents and the adolescents themselves completed follow-up questionnaires when they were 15-16 years of age, with the children evaluating their school performance in relation to their peers and the parents assessing their children's behaviour, on a questionnaire that is widely used to identify ADHD symptoms.
The research was funded by the Academy of Finland; Sigrid Juselius Foundation, Finland; Thule Institute, University of Oulu, Finland; and the National Institute of Mental Health. Dr Rodriguez received support from VINNMER.

Link:

http://www.imperial.ac.uk/press

Роль поврежлений ДНК в атаксии Фридриха

2010-01-22T15:08:00.000+02:00

Очередные открытия связанные с изучением моих любимейших повреждений ДНК описаны на http://www.scienceblog.com/cms/excess-dna-damage-found-cells-patients-friedreichs-ataxia-29177.htm:
PITTSBURGH, Jan. 14 -- Elevated levels of DNA damage have for the first time been found in the cellular mitochondria and nuclei of patients with the inherited, progressive nervous system disease called Friedreich's ataxia (FRDA), says a multicenter research team led by an expert from the University of Pittsburgh Cancer Institute (UPCI). The findings, described today in PLoS Genetics, shed light on the molecular abnormalities that lead to the disease, as well as point the way to new therapeutic approaches and the development of biomarker blood tests to track its progression.
"In FRDA, mutations in the gene frataxin reduce production of a protein that plays a role in keeping iron levels in balance within mitochondria," explained Bennett Van Houten, Ph.D., Richard M. Cyert Professor of Molecular Oncology and leader of the molecular and cellular cancer biology program at UPCI, and professor, Department of Pharmacology and Chemical Biology, University of Pittsburgh School of Medicine. "Frataxin binds iron and helps build iron-sulfur clusters, which are important constituents of cellular proteins.
"While iron is what allows blood cells to carry oxygen, too much iron is toxic to the body," said Astrid C. Haugen, lead author and program analyst at the National Institute of Environmental Health Sciences (NIEHS), part of the National Institutes of Health (NIH). "Friedreich's ataxia leads to iron overload, setting the stage for cumulative DNA damage that eventually affects patients' nerve and muscle cells."
According to the National Institute of Neurological Disorders and Stroke (NINDS), about 1 out of 50,000 Americans has Friedreich's ataxia. Symptoms appear from 5 to 15 years of age and include ataxia, or gait disturbance, that results from degeneration of nerves in the spinal cord and muscle; muscle wasting; and speech problems. Heart enlargement, arrhythmias, and heart failure are common and often the cause of early death in the most severely affected. Patients typically require wheelchairs within 10 to 20 years after symptoms begin.
For the study, the researchers profiled gene activity in blood samples from FRDA children to search for biomarkers of the disease, as compared to young healthy donors. Those data were compared to blood tests from FRDA adults, and the latter compared to a second group of healthy individuals.
"We saw gene activity patterns that are associated with responses to DNA damage, and our comparisons and follow-up tests showed us that FRDA patients have far more damage than seen in healthy people," said Dr. Van Houten, who noted that everyone has some DNA damage, at various stages of repair, in their cells. "We found gene expression signatures that correlated with frataxin levels, age of disease onset and a standardized measure of patient disability."
"If further testing validates the set of genes and activity profiles as predictive biomarkers, they could be useful in assessing the current status of a patient's illness as well as the response to experimental therapies in clinical trials," he said. "Also, new drug targets might be found in the DNA repair and iron-processing pathways affected by the lack of frataxin, generating much-needed treatment breakthroughs."
The study team includes researchers from NIEHS; NINDS; Durham, N.C.-based Expression Analysis Inc.; Duke University; Université Pierre et Marie Curie, Paris; and Hôpital Pitié-Salpêtrière, Paris.
This work was supported by the NIH Intramural Program and a Bench-to-Bedside award.
About UPCI
As the only NCI-designated comprehensive cancer center in western Pennsylvania, UPCI is a recognized leader in providing innovative cancer prevention, detection, diagnosis, and treatment; bio-medical research; compassionate patient care and support; and community-based outreach services. UPCI investigators are world-renowned for their work in clinical and basic cancer research.
About the University of Pittsburgh School of Medicine
As one of the nation's leading academic centers for biomedical research, the University of Pittsburgh School of Medicine integrates advanced technology with basic science across a broad range of disciplines in a continuous quest to harness the power of new knowledge and improve the human condition. Its Department of Pharmacology & Chemical Biology fosters an intellectual and physical environment in which basic chemical principles are applied to the understanding of cell signaling events with the goal of creating new therapeutic strategies. Driven mainly by the School of Medicine and its affiliates, Pitt has ranked among the top 10 recipients of funding from the National Institutes of Health since 1997 and now ranks fifth in the nation, according to preliminary data for fiscal year 2008. Likewise, the School of Medicine is equally committed to advancing the quality and strength of its medical and graduate education programs, for which it is recognized as an innovative leader, and to training highly skilled, compassionate clinicians and creative scientists well-equipped to engage in world-class research. The School of Medicine is the academic partner of UPMC, which has collaborated with the University to raise the standard of medical excellence in Pittsburgh and to position health care as a driving force behind the region's economy. For more information about the School of Medicine, see www.medschool.pitt.edu.

Link:

http://www.upmc.com/communications/newsbureau

Средство борьбы с кокаином!

2010-01-22T14:58:00.000+02:00

Интересные новости. Новый способ борьбы с кокаиновой зависимостью описан на http://www.eurekalert.org/pub_releases/2010-01/fo1b-ana122309.php:
A new ally in the battle against cocaine addiction

A recent study shows that a bacterial protein may help cocaine addicts break the habit.
Cocaine esterase (CocE) is a naturally-occurring bacterial enzyme that breaks down cocaine, thereby reducing its addictive properties. The efficacy of CocE in animals and its suitability for treatment of addiction has been limited by its short half-life in the body.

A recent study, published in the Journal of Pharmacology and Experimental Therapeutics and reviewed by Faculty of 1000 Medicine's Friedbert Weiss, demonstrates that a more stable version of CocE, double mutant or DM CocE, significantly decreased the desire for cocaine and prevented death from cocaine overdose.
In the study, rats were trained to self-administer cocaine by pressing a button in their cage, mimicking the need for regular doses of the drug during addiction. Rats treated with the double mutant form of CocE pressed the button to receive cocaine less often, suggesting that DM-CocE broke down the drug and dampened addiction.

DM-CocE decreased the rats' urge for cocaine but not for an addictive analogue, highlighting the degree of specificity for cocaine. Weiss notes that the DM-CocE enzyme also provides "long-lasting protection" against the toxic effects of a potentially lethal dose.

Though the effects of CocE can be overcome by a sufficiently large dose of cocaine, the present findings suggest that CocE has great promise as a drug abuse treatment.
Weiss says, "These therapeutic approaches may therefore not be "fail-safe" for reducing cocaine intake by determined users" but "long-acting forms of CocE represent potentially valuable treatment approaches not only for the prevention of cocaine-induced toxicity but also for ongoing cocaine abuse in humans."

Две чудесных статьи о привыкании к кофеину

2010-01-10T14:29:00.000+02:00

О гендерных особенностях аддиктивности:
http://www.scientificblogging.com/news_articles/are_male_and_female_adolescents_different_risk_caffeine_addiction
О влиянии кофеина на детей:

http://www.scienceblog.com/cms/addictive-effects-caffeine-kids-being-studied-ub-neurobiologist-28814.html

Ещё о дозировании витаминов

2010-01-10T14:26:00.002+02:00

Интересная статья на http://www.scienceblog.com/cms/putting-limits-vitamin-e-28815.html:
Vitamin-fortified foods and dietary health supplements can ease health worries. But what kinds of vitamins are right for you? And how much of them should you take, and how often?
A research group from Tel Aviv University has done the most comprehensive and accurate study of clinical data on Vitamin E use and heart disease to date, and it warns that indiscriminate use of high-dose Vitamin E supplementation does more harm than good. Their results were recently reported in ATVB, a leading journal of cardiology, and discussed in the journal BioFactors.
"There were so many conflicting reports about Vitamin E and its effect on various diseases, particularly heart disease, that we wanted to set the record straight," says Prof. Dov Lichtenberg of TAU's Sackler School of Medicine.
"Our new study shows that some people may be harmed by the treatment, whereas others may benefit from it. Now we're trying to identify groups of people that are most likely to benefit from the effects of Vitamin E," adds study co-researcher Dr. Ilya Pinchuk. The TAU research team also included decision analyst Dr. Moshe Leshno of the Sackler Faculty of Medicine and the Leon Recanati Faculty of Management and Dr. Yedidya (Didi) Dotan, whose PhD thesis is the basis for this analysis.
A longer life without it?
Applying a very different approach than any previous study, the team of researchers put their heads together to draw definitive conclusions about Vitamin E. In their publication in ATVB the Tel Aviv University researchers evaluated the results of the prominent studies measuring the health benefits of Vitamin E but reached varying conclusions. There have been many previous publications on the subject. Analysis of the results of all these past publications together revealed that subjects who did not take a Vitamin E supplement enjoyed more quality-adjusted-life-years (QALY), a standard parameter used in medicine to assess the effect of medical interventions.
"To explain the meaning of this parameter," says Dr. Pinchuk, "consider a participant who was healthy during the first 10 out of 20 years of the study, but then suffered a stroke and became dependent on others throughout the following 10 years. The QALY during the first 10 years of healthy life is 10, but after the stroke the quality of life is only half of what this person had before. Therefore, the second decade is considered the equivalent of merely 5 years of healthy life and in sum a person's QALY is 15.
The researchers examined data from more than 300,000 subjects in the US, Europe and Israel. "Our major finding," says Dr. Pinchuk, "was that the average quality-adjusted life years (QALY) of Vitamin E- supplemented individuals was 0.30 less than that of untreated people. This, of course, does not mean that everybody consuming Vitamin E shortens their life by almost 4 months. But on average, the quality-adjusted longevity is lower for vitamin-treated people. This says something significant."
Overturning earlier studies
In the BioFactors article, the TAU researchers defined "the real challenge as being able to identify who is likely to benefit taking Vitamin E." They also explored the first hypothesis of the oxidative theory of atherosclerosis published more than 20 years ago, which was the basis for the widespread use of antioxidants today. At first, this hypothesis raised great enthusiasm that anti-oxidants like Vitamins E and C and flavonoids could be used to prevent disease or its progression. In this respect, the new findings are very disappointing.
"We've now concluded that going to the grocery or to a health food store to buy Vitamin E supplements, for the most part, won't do you good. In some cases it can do harm," says Dr. Pinchuk. "A doctor wouldn't prescribe anti-hypertension drugs to the whole population, only to those with low blood pressure. It seems this is true for antioxidants, too. When you give them to everybody, you may be doing more harm than good. Some people may benefit from it, but more may be harmed."
The researchers are now building sets of criteria that detail under what conditions Vitamin E supplements should be taken. They are also investigating the chemical mechanisms of antioxidants in general to better understand how they work.
American Friends of Tel Aviv University (www.aftau.org) supports Israel's leading and most comprehensive center of higher learning. In independent rankings, TAU's innovations and discoveries are cited more often by the global scientific community than all but 20 other universities worldwide.
Internationally recognized for the scope and groundbreaking nature of its research programs, Tel Aviv University consistently produces work with profound implications for the future.

Link:

http://www.aftau.org

Ещё один метод исследования активности мозга

2010-01-10T14:17:00.000+02:00

МИТовцы, как обычно, доисследовались до интересных штук. Читаем на http://www.biologynews.net/archives/2010/01/06/mit_neuroengineers_silence_brain_cells_with_multiple_colors_of_light.html
Neuroscientists at MIT have developed a powerful new class of tools to reversibly shut down brain activity using different colors of light. When targeted to specific neurons, these tools could potentially lead to new treatments for the abnormal brain activity associated with disorders such as chronic pain, epilepsy, brain injury, and Parkinson's disease.

The tools work on the principle that such disorders might be best treated by silencing, rather than stimulating, brain activity. These "super silencers" exert exquisite control over the timing of the shutdown of overactive neural circuits – an effect that's impossible with existing drugs or other conventional therapies.

"Silencing different sets of neurons with different colors of light allows us to understand how they work together to implement brain functions," explains Ed Boyden, senior author of the study, to be published in the Jan. 7 issue of Nature. "Using these new tools, we can look at two neural pathways and study how they compute together. These tools will help us understand how to control neural circuits, leading to new understandings and treatments for brain disorders – some of the biggest unmet medical needs in the world." Boyden is the Benesse Career Development Professor in the MIT Media Lab and an associate member of the McGovern Institute for Brain Research at MIT.

Boyden's super silencers are developed from two genes found in different natural organisms such as bacteria and fungi. These genes, called Arch and Mac, encode for light-activated proteins that help the organisms make energy. When neurons are engineered to express Arch and Mac, researchers can inhibit their activity by shining light on them. Light activates the proteins, which lowers the voltage in the neurons and safely and effectively prevents them from firing. In this way, light can bathe the entire brain and selectively affect only those neurons sensitized to specific colors of light. Neurons engineered to express Arch are specifically silenced by yellow light, while those expressing Mac are silenced by blue light.

"In this way the brain can be programmed with different colors of light to identify and possibly correct the corrupted neural computations that lead to disease," explains co-author Brian Chow, postdoctoral associate in Boyden's lab.

In 2005, Boyden, in collaboration with investigators at Stanford University and the Max Planck Institute, introduced the first such "optogenetic" technique, so called because it combines the use of optics with gene delivery. The 2005 tool, now widely used, involves a light-activated ion channel, ChR2, which allows light to selectively turn on neurons in the brain.

Two years later, Boyden demonstrated that halorhodopsin, another light-sensitive protein, could inhibit the activity of neurons when illuminated. "But the genomic diversity of the world suggested that more powerful tools were out there waiting to be discovered," Boyden says. His group accordingly screened a diverse set of microbial light-sensitive proteins, and found the new multicolor silencers. The newly discovered tools are much better than the old. Arch-expressing neurons were switched off with greater precision and recovered faster than halorhodopsin-expressing neurons, allowing researchers to manipulate different neurons with different colors of light.

"Multicolor silencing dramatically increases the complexity with which you can study neural circuits," says co-author Xue Han, postdoctoral researcher in Boyden's lab. "We will use these tools to parse out the neural mechanisms of cognition."

How they did it: MIT researchers loaded the Arch and Mac genes into viruses that inserted their genetic cargo into mouse neurons. Optical fibers attached to lasers flashed light onto the neurons, and electrodes measured the resulting neural activity. [See graphic]

Next steps: Boyden's team recently demonstrated the efficacy of ChR2 in monkeys with no apparent side effects. Determining whether Arch and Mac are safe and effective in monkeys will be a critical next step toward the potential use of these optical silencing tools in humans. Boyden plans to use these super silencers to examine the neural circuits of cognition and emotion and to find targets in the brain that, when shut down, could relieve pain and treat epilepsy. His group continues to mine the natural world for new and even more powerful tools to manipulate brain cell activity – tools that, he hopes, will empower scientists to explore neural circuits in ways never before possible.

Source : Massachusetts Institute of Technology

Что думают наркоманы?

2009-12-17T22:46:00.001+02:00

Интересно о мнениях наркоманов о том, что они употребляют. Что опаснее - легальные или нелегальные вещества? Читаем: http://www.eurekalert.org/pub_releases/2009-11/ucl-duk112309.php
Drug users know their stuff

Drug users are well informed about the harms associated with the drugs they use, and perceive alcohol and tobacco to be amongst the most dangerous substances, according to a survey by UCL (University College London) and Imperial College London researchers. The findings, published in the Journal of Psychopharmacology, suggest that the current system of classifying psychoactive drugs in the UK may need to be revisited.

The study, led by Dr Celia Morgan and Professor Valerie Curran at UCL, surveyed 1,500 UK drug users via the website www.nationaldrugsurvey.org. Drug users were asked to rate twenty psychoactive substances on a 'rational' scale previously developed by Professor David Nutt, Imperial College London, who collaborated on this study. Heroin, crack and cocaine topped the list in terms of harm, but alcohol was rated fifth, solvents seventh and tobacco ninth. Ecstasy came 13th in the harm rating, LSD 16th and cannabis 18th. Thus, the survey found no relationship between the drug's legal status, based on the current classification system, and users' ratings of harm. In the UK, the Misuse of Drugs Act (1971) currently classifies psychoactive drugs as A, B or C, though alcohol and tobacco remain unclassified.

Dr Celia Morgan, UCL Clinical Psychopharmacology Unit, says: "Given that the Misuse of Drugs Act aims to signal to young people the harmfulness of drugs, this suggests a flaw with the current classification of drugs. We found that drug users rated legal substances such as alcohol and tobacco as more harmful than Class A substances like LSD and ecstasy. We found a high correlation between harm ratings by users and those made previously by scientific experts across all substances, suggesting users are well informed about the harms of drugs.

"The reported prevalence of use of each substance also suggests that the classification of drugs has little bearing on the choice of whether to use substances or not. For example ecstasy, a Class A substance, was the fourth most regularly used psychoactive drug, according to our survey.

"We also asked drug users about their perceived benefits of taking psychoactive substances, as this is clearly important in a person's decision of whether to take a drug or not. Psychoactive substances LSD, cannabis and ecstasy were consistently rated as having the highest short and long-term benefits. These findings add to the debate on the validity of the current classification of drugs in the UK.

"Worldwide, there are an estimated two billion alcohol users, 1.3 billion smokers and 185 million users of other drugs. Despite public health campaigns, levels of substance misuse continue to rise. One of the reasons for this may be the public's confusion about the actual risks of different drugs as they often receive conflicting messages from the legal system, the media and health campaigns. We recommend that future health campaigns consider whether to include the benefits of some drugs. By only citing harms, such campaigns likely represent – from a user's perspective – an unbalanced view and may mean that the overall message is more likely to be ignored."

The authors are following up the study with the launch of a new larger survey, in collaboration with the Beckley Foundation, hosted at www.internationaldrugsurvey.org.

Аминокислотная диета для мозга

2009-12-09T13:13:00.002+02:00

Особая диета для выздоровления мозгов :)ЧИТАЕМ:
http://www.eurekalert.org/pub_releases/2009-12/chop-waa120209.php
May set stage for treating brain damage in people
Neurology researchers have shown that feeding amino acids to brain-injured animals restores their cognitive abilities and may set the stage for the first effective treatment for cognitive impairments suffered by people with traumatic brain injuries.

"We have shown in an animal model that dietary intervention can restore a proper balance of neurochemicals in the injured part of the brain, and simultaneously improves cognitive performance," said study leader Akiva S. Cohen, Ph.D., a neuroscientist at The Children's Hospital of Philadelphia.

The study appears today in the online issue of the Proceedings of the National Academy of Sciences.

If these results in mice can be translated to human medicine, there would be a broad clinical benefit. Every 23 seconds, a man, woman or child in the United States suffers a traumatic brain injury (TBI). The primary cause of death and disability in children and young adults, TBI also accounts for permanent disabilities in more than 5 million Americans. The majority of those cases are from motor vehicle injuries, along with a rising incidence of battlefield casualties.

Although physicians can relieve the dangerous swelling that occurs after a TBI, there are currently no treatments for the underlying brain damage that brings in its wake cognitive losses in memory, learning and other functions.

The animals in the current study received a cocktail of three branched chain amino acids (BCAAs), specifically leucine, isoleucine and valine, in their drinking water. Previous researchers had shown that people with severe brain injuries showed mild functional improvements after receiving BCAAs through an intravenous line.

BCAAs are crucial precursors of two neurotransmitters—glutamate and gamma-aminobutyric acid, or GABA, which function together to maintain an appropriate balance of brain activity. Glutamate excites neurons, stimulating them to fire, while GABA inhibits the firing. Too much excitement or, too little, and the brain doesn't work properly. A TBI upsets the balance.

In particular, a TBI frequently damages the hippocampus, a structure deep in the brain involved in higher learning and memory. In the current study, the researchers found that an injury to the hippocampus reduced levels of BCAAs. Although overall levels of glutamate and GABA were unchanged, the loss of BCAAs disturbed the critical balance of neurotransmitters in the hippocampus, making some localized regions more excitable and others less excitable. Cohen's team tested the hypothesis that providing dietary BCAAs would restore the balance in neural response.

In this study, Cohen's study team first created standardized brain injuries in mice, and one week later compared the animals' conditioned fear response to that of uninjured mice. A week after receiving a mild electric shock in a specific cage, normal mice tend to "freeze" when placed in the same cage, anticipating another shock. The brain-injured mice demonstrated fewer freezing responses—a sign that they had partially lost that piece of learning.

On the other hand, brain-injured mice that received a diet of BCAAs showed the same normal response as the uninjured mice. The BCAA cocktail had restored their learning ability.

In addition to the behavioral results, the team conducted electrophysiological experiments in slices of hippocampus from brain-injured and non-injured mice, and showed that BCAA restored a normal balance of neural activity. "The electrophysiological results were consistent with what we saw in the animals' functional recovery," said Cohen.

If the results in mice can be reproduced in people, patients with traumatic brain injuries could receive the BCAAs in a drink. Cohen suggests that BCAAs as a dietary supplement could have a more sustained, measured benefit than that seen when patients receive BCAAs intravenously, in which the large IV dose may flood brain receptors and have more limited benefits.

Although much work remains to be done to translate the finding into a therapy, Cohen expects to collaborate over the next year with other researchers in an early-phase clinical trial of dietary BCAAs in patients with mild to moderate TBI.

###

The National Institutes of Health provided funding for this study. Cohen's co-authors were Jeffrey Cole, Ph.D., Christina M. Mitala, Ph.D., Suhali Kundu and Itzhak Nissim, Ph.D., all of Children's Hospital; Jaclynn A. Elkind of the University of Pennsylvania; and Ajay Verma, M.D., Ph.D., of the Uniformed Services University of the Health Sciences, Bethesda, Md. Cohen and Nissim are also on the faculty of the University of Pennsylvania School of Medicine.

About The Children's Hospital of Philadelphia: The Children's Hospital of Philadelphia was founded in 1855 as the nation's first pediatric hospital. Through its long-standing commitment to providing exceptional patient care, training new generations of pediatric healthcare professionals and pioneering major research initiatives, Children's Hospital has fostered many discoveries that have benefited children worldwide. Its pediatric research program is among the largest in the country, ranking second in National Institutes of Health funding. In addition, its unique family-centered care and public service programs have brought the 441-bed hospital recognition as a leading advocate for children and adolescents. For more information, visit http://www.chop.edu.

Об окислительном стрессе, маркерах и заболеваниях сердца

2009-11-17T15:30:00.001+02:00

Очень интересная информация с http://www.eurekalert.org/pub_releases/2009-11/eu-moo111309.php
Marker of oxidative stress predicts heart disease outcomes
Judging from the number of juices and teas advertised as containing antioxidants, consumers are aware of the dangers of oxidative stress. But what is the best way to measure it – and fight it?

Doctors at Emory University School of Medicine have identified a substance in the blood that may be useful in predicting an individual's risk for heart disease. The substance is cystine, an oxidized form of the amino acid cysteine and an indirect measure of oxidative stress.

In a study of more than 1,200 people undergoing cardiac imaging at Emory because of suspected heart disease, people with high levels of cystine in the blood were twice as likely to have a heart attack or die over the next few years.

Riyaz Patel, MD, a postdoctoral researcher at Emory's Cardiovascular Research Group, is presenting the results Monday at the American Heart Association Scientific Sessions meeting in Orlando.

Patel was part of a team led by Arshed Quyyumi, MD, professor of medicine (cardiology) at Emory University School of Medicine.

When considered independently of variables such as the presence of diabetes, high levels of cystine still predicted future trouble, Patel says. In the current research, high levels means the quarter of the group of patients with the highest levels.

"Cystine could be a valuable marker of cardiovascular risk, but it also has a direct harmful effect on cells, so reducing it may be a valuable treatment strategy," he says. "What's exciting is there are already known ways to intervene and drive down cystine levels in patients."

For example, a previous study has shown that supplementing the diet with zinc can lower cystine levels, he says.

Several studies have shown that levels of oxidized cysteine in the blood tend to rise as people age. Smoking and alcohol consumption are also linked with higher levels of oxidized cysteine.

Cysteine is itself a short-lived precursor to glutathione, one of the main antioxidants found inside cells, says Dean P. Jones, PhD, professor of medicine and director of the Clinical Biomarkers Laboratory at Emory University School of Medicine.

"We need to have a continuous supply of cysteine, but it is too reactive for us to have very much at any one time," he says. "We are not sure why the oxidized form of cysteine accumulates with aging and disease. But our studies show that when it accumulates, it activates inflammation in cells."

Jones and his colleagues have shown that when white blood cells are exposed to high levels of cystine, they display signs of inflammation and become stickier. That makes them more likely to adhere to blood vessels in the heart, an event that contributes to the development of heart disease.

The team has found that levels of cystine do not correlate with C-reactive protein, a blood marker of inflammation other scientists have studied for a possible relationship with heart disease. The team's future plans include comparing cystine to other markers of inflammation and understanding the relationships between them.

###

More about cysteine and oxidative stress:

http://whsc.emory.edu/home/news/releases/2009/03/targeting-oxidized-cysteine.html
http://whsc.emory.edu/home/publications/medicine/emory-medicine/summer2009/rejuggling-act.html

Reference:

Effects of long-term zinc supplementation on plasma thiol metabolites and redox status in patients with age-related macular degeneration.
SE Moriarty-Craige, KN Ha, P. Sternberg, M. Lynn, S. Bressler, G. Gensler, D.P. Jones. Am J Ophthalmol. 143(2):206-211 (2007)

The Robert W. Woodruff Health Sciences Center of Emory University is an academic health science and service center focused on missions of teaching, research, health care and public service. Its components include the Emory University School of Medicine, Nell Hodgson Woodruff School of Nursing, and Rollins School of Public Health; Yerkes National Primate Research Center; Emory Winship Cancer Institute; and Emory Healthcare, the largest, most comprehensive health system in Georgia. Emory Healthcare includes: The Emory Clinic, Emory-Children's Center, Emory University Hospital, Emory University Hospital Midtown, Wesley Woods Center, and Emory University Orthopaedics & Spine Hospital. The Woodruff Health Sciences Center has $2.3 billion in operating expenses, 18,000 employees, 2,500 full-time and 1,500 affiliated faculty, 4,500 students and trainees, and a $5.7 billion economic impact on metro Atlanta.

Learn more about Emory's health sciences: http://emoryhealthblog.com - @emoryhealthsci (Twitter) - http://emoryhealthsciences.org

Хм. О летальности смеси кокаин+перечный газ

2009-11-13T22:28:00.000+02:00

Отличная статья на http://www.newscientist.com/article/mg20427345.300-cocaine-and-pepper-spray--a-lethal-mix.html?DCMP=OTC-rss&nsref=online-news:
DEATHS in US police custody during the early 1990s may have been the result of an interaction between capsaicin, the key ingredient in pepper sprays, and psychostimulant drugs, an experiment in mice suggests.

If the two have a fatal interaction in people then police forces might have to rethink their use of pepper spray as a non-lethal weapon, says John Mendelson of the Addiction and Pharmacology Research Laboratory at St Luke's Hospital in San Francisco, who led the mouse research.

In the early nineties, anecdotal reports emerged in the US of people dying after being sprayed by police. "They seemed to die very quickly," says Mendelson. At post-mortem, many of these people showed signs of having taken cocaine, so Mendelson wondered if capsaicin and cocaine could interact fatally in the body.

To investigate, his team injected cocaine, capsaicin or both at once into the abdomens of several groups of about 30 mice. Injections allowed them to control the dose of capsaicin the mice received, which wouldn't have been possible if the mice were simply sprayed, says Mendelson.

In one group of mice, cocaine was injected at a dose of 60 milligrams per kilogram of mouse weight, which killed just a few of them. But when the researchers injected a group with the same dose of cocaine plus capsaicin, the death toll was about half. "The presence of capsaicin in mice makes smaller amounts of cocaine more lethal," Mendelson says. When the team gave another group of mice capsaicin along with a higher dose of cocaine - enough to kill half of the mice on its own - the death toll rose to 90 per cent (Forensic Toxicology, DOI: 10.1007/s11419-009-0079-9). "We don't actually know how capsaicin reacts with cocaine to produce a lethal effect," admits Mendelson.

However, his team also reviewed 26 autopsy reports and Californian police reports between 1993 and 1995 of people who died shortly after being subdued with pepper spray. They noted that 19 of them had evidence of psychostimulants in their blood and nine had cocaine. Mendelson suspects that a fatal interaction takes place in the brain between capsaicin and psychostimulants.

Toxicologists are intrigued, but say further evidence is needed. "In real-life situations, humans inhale pepper spray, whereas these mice had the substance injected directly into their abdominal cavities," says Andy Smith of the Medical Research Council in Cambridge, UK. Kathryn Cunningham of the Department of Pharmacology and Toxicology at the University of Texas in Galveston says we don't know how much of the capsaicin that is sprayed in someone's face makes it into their bloodstream.

Peter Bibring, an attorney at the American Civil Liberties Union in Los Angeles, says the study adds weight to the ACLU's concern that pepper spray could be fatal. "Police departments need to make adjustments to minimise the chance it will be used on those under the influence of cocaine."

Norm Leong, a sergeant at the Sacramento Police Department in California says this could be a tough call: "It's impossible to know if someone is under the influence of cocaine, some other drug", has mental issues, or is just resisting arrest.

Об ожидании наслаждения и допамине

2009-11-13T16:34:00.000+02:00

Читаем на http://www.scientificblogging.com/news_articles/link_between_dopamine_and_expectation_pleasure_confirmed
Enhancing the effects of dopamine influences how people make life choices by affecting expectations of pleasure, according to new research from the UCL Institute of Neurology.

Published today in Current Biology, the study confirms an important role for dopamine in how human expectations are formed and how people make complex decisions. It also contributes to an understanding of how pleasure expectation can go awry, for example in drug addiction.

The study builds on earlier research which used brain imaging as participants imagined holiday destinations. An area of the brain called the straitum tracked expectations and the
scientists found that they could take that signal and predict what the participants would choose. The authors believed this was dopamine at work and set-up this study to further explore its role.

The research team examined estimated pleasure of future events before and after the administration of a drug called L-DOPA which is known to enhance dopamine function in the brain and is commonly used to treat patients with Parkinson's disease.

The 61 study participants were asked to rate their expectations of happiness if they were to holiday at each of 80 destinations, from Thailand to Greece. They were then given L-DOPA or a placebo and asked to imagine holidaying in those destinations.

The following day participants had to pick between a series of paired destinations that they had initially assigned with equal ratings, one member of the pair was imagined under L-DOPA the day before and the other under placebo. Finally, they rated the full set of 80 destinations again.

Ratings for particular destinations increased after they were imagined under L-DOPA's influence. That increase also affected the participants' selections the following day. Dr Sharot added: "We had reason to believe that dopamine would enhance expectations of pleasure in humans, but were surprised at the strength of this effect. The enhancement lasted at least 24 hours and was evident in almost 80 per cent of the subjects."

Citation: Tali Sharot, Tamara Shiner,Annemarie C. Brown, Judy Fan,Raymond J. Dolan, 'Dopamine Enhances Expectation of Pleasure in Humans', Current Biology Online 2009, doi:10.1016/j.cub.2009.10.025

Ген, ответственный за биполярное расстройство

2009-11-13T16:28:00.000+02:00

О своём, о маниакально-депрессивном... На http://www.scientificblogging.com/news_articles/faulty_rorb_genes_may_explain_bipolar_disorder_children
A team of researchers said this week that they may have identified the genes responsible for bipolar disorder in children. Their study, published in BMC Psychiatry, implicates malfunctioning circadian clock genes, four alterations of the RORB gene to be specific, in the development of the disorder.

Scientists studied the RORA and RORB genes of 152 children with Bipolar and 140 control children. They found four alterations to the RORB gene that were positively associated with being bipolar. "Our findings suggest that clock genes in general and RORB in particular may be important candidates for further investigation in the search for the molecular basis of bipolar disorder," explained co-author Alexander Niculescu.

RORB is mainly expressed in the eye, pineal gland and brain. Its expression is known to change as a function of circadian rhythm in some tissues, and mice without the gene exhibit circadian rhythm abnormalities.

According to Niculescu, "Bipolar disorder is often characterized by circadian rhythm abnormalities, and this is particularly true among pediatric bipolar patients. Decreased sleep has even been noted as one of the earliest symptoms discriminating children with bipolar disorder from those with attention deficit hyperactivity disorder (ADHD). It will be necessary to verify our association results in other independent samples, and to continue to study the relationship between RORB, other clock genes, and bipolar disorder".

Pediatric bipolar disorder is a controversial diagnosis characterized by alternating bouts of depression and mania in children, although it does not affect all young people in the same way and the duration and severity of the disorder can vary enormously.

Citation: Casey L McGrath, Stephen J Glatt, Pamela Sklar, Helen Le-Niculescu, Ronald Kuczenski, Alysa E Doyle, Joseph Biederman, Eric Mick, Stephen V Faraone, Alexander B Niculescu, Ming T Tsuang, 'Evidence for Genetic Association of RORB with Bipolar Disorder',
BMC Psychiatry 2009, doi:10.1186/1471-244X-9-70

Гипервитаминоз А

2009-10-15T21:34:00.003+03:00

В детстве у меня был гипервитаминоз А - мама решила помочь мне справиться с трещинками на губах и помазала их витамином А из капсулки... Видимо - передоз. Потому что потом ещё неделю я ходила с распухшим, в красных пятнышках, личиком...
Вот и свежая статейка об эффектах витамина А при превышении дозы, читаю тут - http://www.biologynews.net/archives/2009/10/08/too_much_of_a_good_thing_scientists_explain_cellular_effects_of_vitamin_a_overdose_and_deficiency.html:

If a little vitamin A is good, more must be better, right? Wrong! New research published online in the FASEB Journal (http://www.fasebj.org) shows that vitamin A plays a crucial role in energy production within cells, explaining why too much or too little has a complex negative effect on our bodies. This is particularly important as combinations of foods, drinks, creams, and nutritional supplements containing added vitamin A make an overdose more possible than ever before.

"Our work illuminates the value and potential harm of vitamin A use in cosmetic creams and nutritional supplements," said Ulrich Hammerling, co-author of the study, from the Sloan-Kettering Institute for Cancer Research in New York. "Although vitamin A deficiency is not very common in our society, over-use of this vitamin could cause significant disregulation of energy production impacting cell growth and cell death."

Although the importance of vitamin A to human nutrition and fetal development is well-known, it has been unclear why vitamin A deficiencies and overdoses cause such widespread and profound harm to our organs, until now. The discovery by Hammerling and colleagues explains why these effects occur, while also providing insight into vitamin A's anti-cancer effects. The scientists used cultures from both human and mice cells containing specific genetic modifications of the chemical pathways involved in mitochondrial energy production. The cells were then grown with and without vitamin A, and scientists examined the impact on the various steps of energy production. Results showed that retinol, the key component of vitamin A, is essential for the metabolic fitness of mitochondria and acts as a nutritional sensor for the creation of energy in cells. When there is too much or too little vitamin A, mitochondria do not function properly, wreaking havoc on our organs.

"Beauty might be only skin deep, but vitamin A isn't. It goes to the nucleus of our cells and can affect our health for better or worse," said Gerald Weissmann, M.D., Editor-in-Chief of the FASEB Journal. "Using too many products enriched with vitamin A could lead to negative, even fatal, consequences."

Source : Federation of American Societies for Experimental Biology

Безумие и гениальность

2009-10-15T21:32:00.001+03:00

Читаем на http://www.eurekalert.org/pub_releases/2009-09/afps-mgs092809.php

Vincent van Gogh cut off his ear. Sylvia Plath stuck her head in the oven. History teems with examples of great artists acting in very peculiar ways. Were these artists simply mad or brilliant? According to new research reported in Psychological Science, a journal of the Association for Psychological Science, maybe both.

In order to examine the link between psychosis and creativity, psychiatrist Szabolcs Kéri of Semmelweis University in Hungary focused his research on neuregulin 1, a gene that normally plays a role in a variety of brain processes, including development and strengthening communication between neurons. However, a variant of this gene (or genotype) is associated with a greater risk of developing mental disorders, such as schizophrenia and bipolar disorder.

In this study, the researchers recruited volunteers who considered themselves to be very creative and accomplished. They underwent a battery of tests, including assessments for intelligence and creativity. To measure creativity, the volunteers were asked to respond to a series of unusual questions (for example, "Just suppose clouds had strings attached to them which hang down to earth. What would happen?") and were scored based on the originality and flexibility of their answers. They also completed a questionnaire regarding their lifetime creative achievements before the researchers took blood samples.

The results show a clear link between neuregulin 1 and creativity: Volunteers with the specific variant of this gene were more likely to have higher scores on the creativity assessment and also greater lifetime creative achievements than volunteers with a different form of the gene. Kéri notes that this is the first study to show that a genetic variant associated with psychosis may have some beneficial functions. He observes that "molecular factors that are loosely associated with severe mental disorders but are present in many healthy people may have an advantage enabling us to think more creatively." In addition, these findings suggest that certain genetic variations, even though associated with adverse health problems, may survive evolutionary selection and remain in a population's gene pool if they also have beneficial effects.

###

For more information about this study, please contact: Szabolcs Kéri (szkeri@phys.szote.u-szeged.hu)

Psychological Science is ranked among the top 10 general psychology journals for impact by the Institute for Scientific Information. For a copy of the article "Genes for Psychosis and Creativity" and access to other Psychological Science research findings, please contact Barbara Isanski at 202-293-9300 or bisanski@psychologicalscience.org

Активные формы Кислорода в сигнальных каскадах!

2009-10-15T21:29:00.004+03:00

Немного новостей об АФК в новом функциональном свете на http://www.eurekalert.org/pub_releases/2009-09/uoc--roi092309.php

For years, health conscious people have been taking antioxidants to reduce the levels of reactive oxygen in their blood and prevent the DNA damage done by free radicals, which are the result of oxidative stress. But could excessive use of antioxidants deplete our immune systems?

Research at UCLA's Jonsson Comprehensive Cancer Center has raised that question.

It has been known for decades that reactive oxygen species (ROS) - ions or very small molecules that include free radicals - damage cells. But much to their surprise, Jonsson Cancer Center researchers found that in Drosophila, the common fruit fly, moderately elevated levels of ROS are a good thing.

These small molecules act as an internal communicator, signaling certain blood precursor cells, or blood stem cells, to differentiate into immune-bolstering cells in reaction to a threat. After the progenitor cells differentiate, the ROS levels return to normal, ensuring the safety and survival of the mature blood cells, said Utpal Banerjee, a Jonsson Cancer Center researcher and senior author of the study.

The study is published in the Sept. 24, 2009 issue of the peer-reviewed journal Nature.

The new finding was launched when Banerjee and his team set out to discover why fruit flies had naturally occurring, slightly elevated levels of ROS in their blood cell precursors, which is atypical of most other precursor cells.

"Reducing levels of reactive oxygen is usually the goal, and what we found was surprising," said Banerjee, professor and chairman of the molecular, cell, and developmental biology department at UCLA. "Most stem cells don't want to be damaged, so they have very low ROS levels. We wanted to know why this was different in the cells that we were investigating."

Banerjee discovered that when ROS was taken away in the blood stem cells, they failed to differentiate into the immune-bolstering cells, called macrophages. On the other hand, when levels of ROS were further increased by genetic means, the blood stem cells "differentiated like gang busters," Banerjee said, making a large number of macrophages.

But how did this happen? The ROS, Banerjee said, acted as a signaling mechanism that kept the blood stem cells in a certain state – when levels rose, it was a message to the cell to differentiate.

The implications from the finding are several fold, Banerjee said. The blood stem cells are stress sensing cells, their function is to sense conditions that increase oxidative stress and react with an immune response. Keeping their ROS levels slightly elevated puts the cells on alert, sensitized and ready to respond to any threat quickly.

That sparked a question: If fruit fly blood stem cells and mammalian blood stem cells operate in the same way, is it a good thing for people to be taking antioxidants? Are antioxidants dulling the immune system and its ability to react to threats?

"On the one hand, it's good to have antioxidants to reduce the amount of reactive oxygen in our body that causes DNA damage," Banerjee said. "But if we find that those blood stem cells aren't primed to respond because the ROS levels are reduced, that would not be a good thing. Our findings raise the possibility that wanton overdose of antioxidant products may in fact inhibit formation of cells participating in innate immune response."

It is known that certain types of mammalian blood stem cells, called common myeloid progenitors, do have elevated levels of ROS, but it isn't known whether those levels operate as messengers for differentiation. Studies of mammalian systems are needed to determine why ROS levels are elevated and what, if any, function that serves in the cell. It is interesting, however, that these types of blood progenitors in mammals also give rise to macrophages, Banerjee said.

"What we found is that the fruit fly keeps its own ROS levels in the blood stem cells slightly high for its own benefit," Banerjee said. "We do not have any direct evidence that this is true in humans, but our results suggest that further studies are needed to investigate a possible signaling role for ROS in the differentiation of precursor cells in mammalian myeloid cell development and oxidative stress response."

###

UCLA's Jonsson Comprehensive Cancer Center has more than 240 researchers and clinicians engaged in disease research, prevention, detection, control, treatment and education. One of the nation's largest comprehensive cancer centers, the Jonsson center is dedicated to promoting research and translating basic science into leading-edge clinical studies. In July 2009, the Jonsson Cancer Center was named among the top 12 cancer centers nationwide by U.S. News & World Report, a ranking it has held for 10 consecutive years. For more information on the Jonsson Cancer Center, visit our website at http://www.cancer.ucla.edu.

Новое лекарство от шизофрении

2009-10-15T21:28:00.000+03:00

Интересно, как обычно на этом блоге! Статья с http://scienceblogs.com/corpuscallosum/2009/09/iloperidone_approved_for_treat.php?utm_source=combinedfeed&utm_medium=rss
The new drug is called iloperidone; the brand name in the USA will be Fanapt. It is yet another antipsychotic that blocks D2 and 5HT2 receptors. Although there is no universally accepted way of classifying drugs into families, it will be referred to as an atypical or second-generation antipsychotic. This designation will indicate a loose kind of similarity to risperidone, aripiperazole, ziprasidone, quetiapine, olanzapine, clozapine, and paliperidone.

It turns out that there is a Wikipedia page for iloperidone. It is not one of the better pages on Wikipedia.

Iloperidone is a monoamine directed towards acting upon and antagonizing specific neurotransmitters.

Iloperidone does act upon the transmitter. It blocks the receptor, which causes the transmitter to be ineffective, or less effective, at transmitting whatever message it otherwise would have transmitted.

There are several other quibbles I have with the Wikipedia page. If I were unemployed, I would edit it. But it is going to take a lot of work.

Anyway, I could write the kind of blog post that I usually have written when potentially-interesting new drugs come out. But it turns out that there is already a good, concise article in an open-access journal. It says all the things I would have said.

Iloperidone for schizophrenia
Peter J. Weiden, MD, and Jeffrey R. Bishop, PharmD, BCPP
Current Psychiatry Online
Vol. 8, No. 9 / September 2009

Iloperidone is a second-generation (atypical) antipsychotic the FDA approved in May 2009 for treating acute schizophrenia in adults (Table 1). Iloperidone is not a derivative (metabolite, isomer, or different formulation) of any other antipsychotic. Clinical trials have shown that iloperidone is efficacious and suggest that for some patients its side-effect profile may be more favorable than that of other antipsychotics.

It is expected to be available later this year. It is not possible for me, or anyone else, to say exactly when this will be.

The high points are: oral bioavailability 95%, half-life about 18 hours, protein binding about 95%, high affinity for D2 and 5HT2A, low for H1, minimal for muscarinic, and moderate for NEα1. The cost will be too high, but I don't know exactly how high. The manufacturer, Vanda Pharmaceuticals, reportedly is working on a long-acting injectable product.

The one sort of interesting thing has to do with the alpha-1 antagonism. This is a nuisance sometimes, because it can cause orthostatic hypotension (dizziness upon standing up, due to drop in blood pressure). This is a side effect, which may or may not happen in a given individual. It is potentially an adverse effect.

Prazosin is an antihypertensive drug that blocks alpha-1 receptors. Prazosin has been used, off-label, to reduce nightmares in persons with PTSD.

Could iloperidone have a similar effect? If so, it would be a side effect, but not an adverse effect. It would be a beneficial side effect. It remains to be seen whether this will turn out to be the case. In general, it is tricky to anticipate clinical effects, based upon the in vitro pharmacology of a drug, when it comes to the effects in the brain.

Несколько весёлостей из научных новостей о сексе

2009-10-15T21:03:00.001+03:00

Здесь - о сексе и оргазме. Всегда ли одно не возможно без другого?
Здесь - о полезности здоровой сексуальной жизни для самочувствия женщин.

Об эффективности обогащённой тромбоцитами плазмы

2009-10-02T14:32:00.001+03:00

Ещё один объект моего изучения и тестирования попал сегодня в сводку новостей с научных фронтов. Прочитала на http://www.biologynews.net/archives/2009/10/01/plateletrich_plasma_does_it_work.html:

Platelet -rich plasma (PRP) is currently used as an alternative treatment method for several common orthopaedic-related sports medicine conditions. According to a new study in the October issue of the Journal of the American Academy of Orthopaedic Surgeons (JAAOS), early outcomes of PRP appear promising; however, larger clinical studies are still needed to determine the benefits of its use.

"Some believe that PRP may catalyze the body's repair mechanisms at areas of injury, improve healing and shorten recovery time," said study co-author Michael Hall, MD, a senior orthopaedic surgery resident at the NYU Hospital for Joint Diseases in New York. "However, there currently is minimal evidence of this clinically and more research must be performed."

A Simple Process and Procedure

Obtaining and utilizing PRP is a relatively simple process: a patient's own blood is placed into a centrifuge that rotates at high speed.
This procedure separates the red blood cells from the platelets, which are blood cells that release growth factors that help the body heal itself.
Next, the physician takes the platelet-rich portion of this blood (PRP) and injects it directly into the patient's injured area and the treatment is complete.

PRP Used Primarily for Chronic Conditions

PRP treatments have been used for the past two decades to improve wound healing and bone grafting procedures by plastic and maxillofacial (mouth, jaw and neck) surgeons. It is only in recent years that orthopaedic surgeons and sports medicine specialists have utilized this technology.

PRP use in sports medicine primarily has been for the treatment of chronic tendon conditions, but also for acute muscle injuries and for the augmentation of tendon repair in the operating room.

The most common applications include:

tennis elbow (lateral epicondylitis);
Achilles tendonitis (inflammation and swelling of the Achilles tendon);
patellar tendonitis (inflammation of the patellar tendon, also called "Jumper's Knee"); and
rotator cuff tendonopathy.

Should I Have PRP Treatment?

According to Dr. Hall, PRP use has increased in recent years, and it has become a popular topic of discussion because the process is "simple, quick and relatively safe for patients."

"Use of PRP has increased, in large part due to new devices that enable fast preparation in the outpatient setting. A patient gives a blood sample and 30 minutes later can receive their injection," he explained. "There is always a risk of infection with any injection, and some have reported increased pain or inflammation at the injection site, but otherwise the risks with PRP appear minimal."

Questions to Ask Your Doctor

Each patient and injury is unique; therefore it is important to discuss any treatment with an orthopaedic surgeon. If PRP treatment is recommended, Dr. Hall suggests asking your doctor the following to help determine if it is right for you:

What is your experience in administering PRP? (Precise placement of PRP injection into the area of injury is important for it to be effective, therefore physicians with more experience may be best.)
What are possible side effects? (Examples include increased pain or inflammation at the injection site.)
How many injections will I receive? (Several studies have reported using multiple injections, but the benefit of this is unknown.)
Will there be any restrictions? (Generally, patients are asked to avoid strenuous activity or sports for a short period of time after the injection to aid in the healing process.)
Will my insurance cover treatment? (Currently, most insurance companies do not cover treatment.)

Also, before embarking on PRP, Dr. Hall suggests trying conventional treatments, such as anti-inflammatory medications, physical therapy, massage, activity modification, bracing and even cortisone injections.

"The bottom line is that there are some studies indicating that PRP may be beneficial in the healing process. Does it really have a positive effect clinically? We don't know," said Dr. Hall. "The good news is that there are a tremendous amount of studies underway. Hopefully, in the next few years, we will be able to help determine the true benefit of PRP."

Source : American Academy of Orthopaedic Surgeons

Конопля без каннабиноидов

2009-09-23T14:15:00.000+03:00

До чего дошла наука... Читаем на http://www.biology-blog.com/blogs/permalinks/9-2009/drug-free-cannabis-plant.html
Drug-free Cannabis plant
In a first step toward engineering a drug-free Cannabis plant for hemp fiber and oil, University of Minnesota scientists have identified genes producing tetrahydrocannabinol (THC), the psychoactive substance in marijuana. Studying the genes could also lead to new and better drugs for pain, nausea and other conditions. The finding is reported in the recent issue of the Journal of Experimental Botany Main author is David Marks, a professor of plant biology in the College of Biological Sciences. The study revealed that the genes are active in tiny hairs covering the flowers of Cannabis plants. In marijuana, the hairs accumulate high amounts of THC, whereas in hemp the hairs have little. Hemp and marijuana are difficult to distinguish apart from differences in THC. With the genes identified, finding a way to silence themand thus produce a drug-free plant comes a step closer to reality. Another desirable step is to make drug-free plants visually recognizable. Since the hairs can be seen with a magnifying glass, this could be accomplished by engineering a hairless Cannabis plant. The scientists are currently using the methods of the latest study to identify genes that lead to hair growth in hopes of silencing them. "We are beginning to understand which genes control hair growth in other plants, and the resources created in our study will allow us to look for similar genes in Cannabis sativa," said Marks. "Cannabis genetics can contribute to better agriculture, medicine, and drug enforcement," said George Weiblen, an associate professor of plant biology and a co-author of the study. As with Dobermans and Dachshunds, marijuana and hemp are different breeds of the same species (Cannabis sativa), but marijuana contains much more THC than hemp, which is a source of industrial fiber and nutritious oil. Hemp was raised for its fiber which is similar to cotton but more durable in the United States until legislation outlawed all Cannabis plants because they contain THC. Today, marijuana contains as much as 25 percent THC, whereas hemp plants contain less than 0.3 percent. Hemp was once a popular crop in the upper Midwest because it tolerates a cool climate and marginal soils that won't support other crops but, after drug legislation, hemp fiber was replaced by plastic and other alternatives. Recent popular demand for hemp products has led some states to consider the economic and environmental benefits of hemp. North Dakota legislation aims to reintroduce it as a crop, and Minnesota is considering similar legislation. At the same time, California and other states permit the medicinal use of marijuana. "I can't think of a plant so regarded as a menace by some and a miracle by others," says Weiblen, who is one of the few scientists in the United States permitted to study Cannabis genetics. In 2006, Weiblen and his colleagues developed a DNA "fingerprinting" technique capable of distinguishing among Cannabis plants in criminal investigations. Posted by: Erica Source

Роль активных форм Кислорода в формировании метастазов

2009-09-23T14:11:00.000+03:00

Читаю на http://www.eurekalert.org/pub_releases/2009-09/bi-ror091509.php Reactive oxygen's role in metastasis
LA JOLLA, Calif., September 15, 2009 -- Researchers at the Burnham Institute for Medical Research (Burnham) have discovered that reactive oxygen species, such as superoxide and hydrogen peroxide, play a key role in forming invadopodia, cellular protrusions implicated in cancer cell migration and tumor metastasis. Sara Courtneidge, Ph.D., professor and director of the Tumor Microenvironment Program at Burnham's NCI-designated Cancer Center, and colleagues have found that inhibiting reactive oxygen reduces invadopodia formation and limits cancer cell invasion. The study was published on September 15 in the journal Science Signaling.
In a companion paper, published in the same issue of Science Signaling, Gary Bokoch, Ph.D., of The Scripps Research Institute, in collaboration with Dr. Courtneidge, found that the proteins Tks4 and Tks5, commonly expressed in cancer cells, are functionally related to p47phox, a protein found in phagocytes that is part of a complex that is instrumental in producing reactive oxygen to mount an immune response.
"Reactive oxygen has a complex cellular role," said Dr. Courtneidge. "Normal cells use reactive oxygen to signal, grow and move. Immune cells, such as neutrophils, produce reactive oxygen to destroy bacteria. Now we find that reactive oxygen is necessary for invadopodia formation, which allows cancer cells to become metastatic."
Invadopodia facilitate cancer cell migration by breaking down the extracellular matrix that normally keeps cells in place. In previous research, Dr. Courtneidge discovered that Tks5 is crucial for invadopodia formation. The structural similarities between Tks5 and p47phox, which is part of the NADPH oxidase (Nox) system, led Dr. Courtneidge to consider the role reactive oxygen plays in invadopodia formation.
Using invadopodia-rich mouse fibrosarcoma cells, the Courtneidge laboratory tested a number of antioxidants and found both a marked reduction in invadopodia formation and invasive behavior. In addition, the team inhibited expression of Nox family enzymes with siRNA and had similar results, demonstrating that NADPH oxidases are involved in invadopodia formation. The scientists repeated these experiments with human melanoma, head and neck and breast cancer cell lines and also saw a marked reduction in invadopodia formation.
With the discovery of reactive oxygen's role in invadopodia formation, researchers have additional possibilities for drug intervention. Future research and drug development may focus on inhibiting NADPH oxidase activity and limiting invadopodia formation to prevent cancer cell migration.

При повреждениях ДНК срабатывает сигнализация!

2009-08-15T19:57:00.000+03:00

Интересные новости с http://www.biologynews.net/archives/2009/08/13/raising_the_alarm_when_dna_goes_bad.html:

Our genome is constantly under attack from things like UV light and toxins, which can damage or even break DNA strands and ultimately lead to cancer and other diseases. Scientists have known for a long time that when DNA is damaged, a key enzyme sets off a cellular 'alarm bell' to alert the cell to start the repair process, but until recently little was known about how the cell detects and responds to this alarm. In a study published today in Nature Structural and Molecular Biology, researchers at the European Molecular Biology Laboratory (EMBL) in Heidelberg, Germany, have identified a whole family of proteins capable of a direct response to the alarm signal.

Our genome is a huge repository of information guiding the construction and function of all the cells in our bodies. Cells sustain many hits to their DNA every day, which can lead tomutations, so they maintain a fleet of DNA repair machinery that can be rapidly mobilised and sent to damaged sites in an emergency.

Because our DNA is so long and unwieldy, it needs to be packaged up with proteins and organised into a complex structure called chromatin. Scientists have known for 50 years that one component of chromatin, an enzyme known as PARP1, is activated by DNA damage and produces a molecular signal, called PAR, which raises the alarm at the site of the damage. In recent weeks, scientists have for the first time worked out how PAR is rapidly detected by the cell; in their Nature Structural and Molecular Biology paper, the group of Andreas Ladurner and their colleagues at EMBL have identified a whole family of proteins that respond to this signal by binding to it directly.

What these proteins share is a special region called a macrodomain. By using a laser to reproduce DNA damage in the lab, the scientists were able to follow fluorescently-labelled macrodomain proteins in cells and observed that they quickly move to the site of DNA damage. A high-resolution image, obtained by X-ray crystallography, shows how the macrodomain forms a 'pocket' fitting the PAR signal exactly.

Among the members of the family the researchers found a protein called histone macroH2A1.1. "This was very surprising. Histones play a major role in assembling chromatin and keeping it together, but they don't usually have macrodomains," says Ladurner. "The finding is particularly relevant, because it turns out that cancer cells don't have macroH2A1.1. The fact that one member of the rapid response team that detects DNA damage is missing could contribute to the disease."

Because macroH2A1.1 is embedded in chromatin, when it recognises PAR at DNA damage sites, it drags the complex but highly-organised tangle of chromatin with it. As a result, macroH2A1.1 condenses the chromatin environment around the damaged area.

The scientists are now trying to understand why this happens. One plausible explanation could be that by temporarily compacting the DNA, the broken ends of the DNA molecule are kept closer together. This should increase the chances of being able to repair it.

"With these findings we've opened up completely new perspectives to a fifty-year-old field of research," says Ladurner. "We're very excited of what lies ahead and hope that we'll soon be much closer in understanding how PARP1 and macrodomains together maintain a healthy genome."

Source : European Molecular Biology Laboratory

Новое о курении марихуаны

2009-08-08T18:44:00.002+03:00

Нашла на http://www.eurekalert.org/pub_releases/2009-08/acs-geo_1080509.php

In a finding that challenges the increasingly popular belief that smoking marijuana is less harmful to health than smoking tobacco, researchers in Canada are reporting that smoking marijuana, like smoking tobacco, has toxic effects on cells. Their study is scheduled for the Aug. 17 issue of ACS' Chemical Research in Toxicology, a monthly journal.

Rebecca Maertens and colleagues note that people often view marijuana as a "natural" product and less harmful than tobacco. As public attitudes toward marijuana change and legal restrictions ease in some countries, use of marijuana is increasing. Scientists know that marijuana smoke has adverse effects on the lungs. However, there is little knowledge about marijuana's potential to cause lung cancer due to the difficulty in identifying and studying people who have smoked only marijuana.

The new study begins to address that question by comparing marijuana smoke vs. tobacco smoke in terms of toxicity to cells and to DNA. Scientists exposed cultured animal cells and bacteria to condensed smoke samples from both marijuana and tobacco. There were distinct differences in the degree and type of toxicity elicited by marijuana and cigarette smoke. Marijuana smoke caused significantly more damage to cells and DNA than tobacco smoke, the researchers note. However, tobacco smoke caused chromosome damage while marijuana did not.

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ARTICLE #2 FOR IMMEDIATE RELEASE
"The Genotoxicity of Mainstream and Sidestream Marijuana and Tobacco Smoke Condensates"

DOWNLOAD FULL TEXT ARTICLE: http://pubs.acs.org/stoken/presspac/presspac/full/10.1021/tx9000286

Кортинко улыбнуло

2009-07-25T20:26:00.001+03:00

Весёленькая пикча. :) Отсюда - ianheath653.wordpress.com/category/humor/page/8/

Немного о болевой чувствительности

2009-07-22T00:36:00.001+03:00

Отличная заметка в блоге у http://scienceblogs.com/neurophilosophy/2009/07/swearing_increases_pain_tolerance.php

Category: Neuroscience • Psychology
Posted on: July 13, 2009 1:02 PM, by Mo

SWEARING OCCURS IN most cultures - people swear to let off steam, or to shock or insult others. It is also a common response to a painful experience. We've all done it: after stubbing our toe, or hitting our thumb with a hammer, we draw a sharp breath and mutter a swear word. Until now, though, whether swearing actually alters our perception of pain had not been investigated. But according to a new study due to be published next month in the journal NeuroReport, swearing increases pain tolerance, enabling us to withstand at least one form of pain for longer.

Some pain theorists regard our tendency to swear after hurting ourselves to be a form of "pain-related catastrophising" - an exaggerated negative mind set which is brought to bear during a painful experience. As such, swearing is thought of as a maladaptive response, which contributes to the intensity of the pain and emotional distress. Given that it is such a common response, Richard Stephens and his colleagues at the Keele University School of Psychology set out test the hypothesis that swearing would decrease pain tolerance and increase pain perception.

They recruited 67 undergraduates, and asked to make two short lists of words - one containing five words they might use after hitting themselves on the thumb with a hammer, the other containing five words they might use to describe a table. The participants submerged one of their hands into room temperature water for three minutes, to provide a standardized starting point, then transferred it to a container of cold water and instructed to keep it submerged for as long as they could. In one condition, they were told to repeat the first swear word they had included in their list; in another, they repeated one of the words describing a table.

The researchers measured how long the participants kept their hands submerged in cold water, and asked them to rate the amount of pain they felt. Their heart rates were also recorded after they had submerged their hands in room temperature water as well as after the submersion in cold water. Contrary to their hypothesis, they found that swearing actually reduced the amount of pain felt. The participants kept their hands submerged in the cold water longer for longer, and also reported experiencing less pain, when they repeated a swear word than when they repeated a word describing a table. Swearing was also associated with increased heart rate.

Swearing therefore enabled the participants to tolerate to the cold temperature for longer, and also caused a reduction in their perception of the pain felt. A difference between males and females was observed. Swearing led to a greater reduction in pain perception and a bigger increase in heart rate in females. Most interestingly though, the effect of swearing in females occurred regardless of their tendency to catastrophise their pain. On the other hand, in the males, catastrophising was found to diminish the effects of swearing on the felt pain. This is interesting in light of other findings which show that men generally catastrophise less, but swear more often, than women.

This study shows that swearing appears to have an analgesic effect under certain conditions. Exactly how is unclear, but the authors suggest that it is because swearing induces negative emotions. It is well known that pain has a strong emotional aspect to it. Fear of pain, for example, is known to enhance pain perception, possibily by activating pathways which descend from the brain and modulate noxious stimuli entering the spinal cord. Swearing, too, is known to induce negative emotions (according to Steven Pinker, it taps into the "deep and ancient parts of the emotional brain"). It may therefore trigger a physiological alarm reaction known as the fight or flight response, which accelerates the heart rate and reduces sensitivity to pain.

Клетки с повреждённой ДНК общаются между собой :)

2009-07-14T13:45:00.000+03:00

Здорово! Читаю на http://www.biologynews.net/archives/2009/07/13/dnadamaged_cells_communicate_with_neighbors_to_let_them_know_theyre_in_trouble.html
When cells experiencing DNA damage fail to repair themselves, they send a signal to their neighbors letting them know they're in trouble. The discovery, which shows that a process dubbed the DDR (DNA Damage Response) also controls communication from cell to cell, has implications for both cancer and aging. The findings appear in the July 13 online edition of the Nature Cell Biology.
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When a cell experiences DNA damage, its first response is to try to repair the damage. If that doesn't work the cell, hopefully, either commits suicide or stops dividing, two intrinsic mechanisms for preventing cancer according to Judith Campisi, PhD, lead author of the study and a faculty member at the Buck Institute for Age Research. The discovery of the extracellular signaling mechanism, which sets off an inflammatory response, explains how unsuccessful DNA repair at the cellular level impacts tissues, which are the vital units of function in complex organisms like humans, she said.
"With regard to cancer, we found that if there is a mutant and potentially cancerous cell in the vicinity of the damaged cell, the signals from the damaged cell can encourage that mutant cell to behave more aggressively cancerous," said Campisi. "With regard to aging, we think the inflammatory signals from damaged cells propagate an aging 'field' whereby damage builds up over time, impacting not only the individual damaged cells, but the function of the tissue itself." When Buck scientists disabled particular proteins involved in the DDR, the cell-to-cell communication was cut off.
Buck Institute scientist Francis Rodier, PhD, led the team that did the research in the Campisi lab. He was surprised to find that even though the DDR signaling process was activated inside the cultured human cells within minutes of the DNA damage, it took 24 to 48 hours for the damaged cells to start secreting the inflammatory signals.
"We think the cell is giving itself time to repair its DNA before alerting the immune system that there's a problem," said Rodier. He added that scientists were also surprised to discover that the damage-induced communication signaling pathway bypasses a powerful tumor suppressor gene known as p53. That finding gives scientists a target to shut down the inflammatory process without hampering the activity of p53, which is essential to prevent cancer. It also explains why cancerous tumors are still able to secrete inflammatory signals when p53 has mutated and lost its tumor suppressing capabilities.
"Inflammation is a hallmark symptom of cancer," said Rodier. "Inflammation also promotes cancer, so this helps us begin to understand what's involved in that process."
The findings also help explain the aging process Campisi said. The immune system, which destroys damaged cells (such as skin cells whose DNA has been exposed to UV radiation), is not perfect, she said. "Damaged cells that survive the activity of the immune system are sending out continuous danger signals to surrounding cells. That constant alarm drives inflammation, which helps drive aging." Campisi added, "Now we have a target to focus on that could stop those damaged cells from sending out the inflammatory signals."
Source : Buck Institute for Age Research

Регулярный секс и повреждения ДНК

2009-07-06T12:05:00.000+03:00

Занятно! Читаю на http://www.biologynews.net/archives/2009/06/30/daily_sex_helps_to_reduce_sperm_dna_damage_and_improve_fertility.html

Daily sex (or ejaculating daily) for seven days improves men's sperm quality by reducing the amount of DNA damage, according to an Australian study presented today (Tuesday) to the 25th annual meeting of the European Society of Human Reproduction and Embryology in Amsterdam.

Until now there has been no evidence-based consensus amongst fertility specialists as to whether or not men should refrain from sex for a few days before attempting to conceive with their partner, either spontaneously or via assisted reproduction.

Dr David Greening, an obstetrician and gynaecologist with sub specialist training in reproductive endocrinology and infertility at Sydney IVF, Wollongong, Australia, said: "All that we knew was that intercourse on the day of ovulation offered the highest chance of pregnancy, but we did not know what was the best advice for the period leading up to ovulation or egg retrieval for IVF.

"I thought that frequent ejaculation might be a physiological mechanism to improve sperm DNA damage, while maintaining semen levels within the normal, fertile range."

To investigate this hypothesis, Dr Greening studied 118 men who had higher than normal sperm DNA damage as indicated by a DNA Fragmentation Index (DFI). Men who had a more than 15% of their sperm (DFI >15%) damaged were eligible for the trial. At Sydney IVF, sperm DNA damage is defined as less than 15% DFI for excellent quality sperm, 15-24% DFI for good, 25-29% DFI for fair and more than 29% DFI for poor quality; but other laboratories can have slightly different ranges.

The men were instructed to ejaculate daily for seven days, and no other treatment or lifestyle changes were suggested. Before they started, levels of DNA damage ranged between 15% and 98% DFI, with an average 34% DFI when measured after three days' abstinence. When the men's sperm was re-assessed on the seventh day, Dr Greening found that 96 men (81%) had an average 12% decrease in their sperm DNA damage, while 22 men (19%) and an average increase in damage of nearly 10%. The average for the whole group dropped to 26% DFI.

Dr Greening said: "Although the mean average was 26% which is in the 'fair' range for sperm quality, this included 18% of men whose sperm DNA damage increased as well as those whose DNA damage decreased. Amongst the men whose damage decreased, their average dropped by 12% to just under 23% DFI, which puts them in the 'good' range. Also, more men moved into the 'good' range and out of the 'poor' or 'fair' range. These changes were substantial and statistically highly significant.

"In addition, we found that although frequent ejaculation decreased semen volume and sperm concentrations, it did not compromise sperm motility and, in fact, this rose slightly but significantly.

"Further research is required to see whether the improvement in these men's sperm quality translates into better pregnancy rates, but other, previous studies have shown the relationship between sperm DNA damage and pregnancy rates.

"The optimal number of days of ejaculation might be more or less than seven days, but a week appears manageable and favourable. It seems safe to conclude that couples with relatively normal semen parameters should have sex daily for up to a week before the ovulation date. In the context of assisted reproduction, this simple treatment may assist in improving sperm quality and ultimately achieving a pregnancy. In addition, these results may mean that men play a greater role in infertility than previously suspected, and that ejaculatory frequency is important for improving sperm quality, especially as men age and during assisted reproduction cycles."

Dr Greening said he thought the reason why sperm quality improved with frequent ejaculation was because the sperm had a shorter exposure in the testicular ducts and epididymis to reactive oxygen species – very small molecules, high levels of which can damage cells. "The remainder of the men who had an increase in DFI might have a different explanation for their sperm DNA damage," he concluded.

Source : European Society for Human Reproduction and Embryology

Восстановление функций мозга после метамфетаминовой абстиненции

2009-07-06T11:50:00.002+03:00

Интересно написано на http://www.biologynews.net/archives/2009/06/29/brain_functions_that_can_prevent_relapse_improve_after_a_year_of_methamphetamine_abstinence.html
Іn a study published online by the Journal of Substance Abuse Treatment, UC Davis researchers report that it takes at least a year for former methamphetamine users to regain impulse control. The results tell recovering substance abusers, their families and drug-treatment specialists that it can take an extended period of time for the brain functions critical to recovery to improve.

"Recovery from meth abuse does not happen overnight," said Ruth Salo, lead author of the study and a UC Davis assistant professor of psychiatry and behavioral sciences. "It may take a year — or even longer — for cognitive processes such as impulse control and attentional focus to improve. Treatment programs need to consider this when monitoring recovering addicts' progress during their early periods of abstinence."

Salo specializes in the behavioral, neuropsychiatric and cognitive outcomes of methamphetamine addiction — a particularly difficult condition to treat, primarily due to prolonged, intense cravings for the drug. During her career, she has worked with hundreds of methamphetamine addicts.

"All of them want to know if there is hope," Salo said. "We used to think most, if not all, effects of meth addiction were permanent. This study adds to the growing evidence that this assumption is not true. I can confidently tell patients that the longer they stay in a structured rehabilitation program and remain drug free, the more likely it is that they will recover some important brain functions."

For the current study, Salo used the widely-validated, computer-based Stroop attention test to measure the abilities of 65 recovering methamphetamine abusers to use cognitive control — or direct their attention to specific tasks while ignoring distractors. Study participants had been abstinent for a minimum of three weeks and a maximum of 10 years, and they had previously used the drug for periods ranging from 24 months to 28 years. The data for the 65 individuals were compared to Stroop attention test data from 33 participants who had never used methamphetamine.

"The test taps into something people do in everyday life: make choices in the face of conflicting impulses that can promote a strong but detrimental tendency," Salo explained. "For meth users, impairments in this decision-making ability might make them more likely to spend a paycheck on the immediate satisfaction of getting high rather than on the longer-term satisfaction gained by paying rent or buying groceries."

The study analyzed cognitive control in terms of the amount of time since methamphetamine was last used as well as total time spent using the drug. The researchers found that those who were recently abstinent (three weeks to six months) performed significantly worse on the Stroop test than those who had been abstinent one year or longer. In addition, there was no statistical difference between test results for those abstinent at least one year and non-drug using controls. Longer-term methamphetamine use was associated with worse test scores. Similarly, longer-term abstinence was connected to improved test performance.

According to Salo, the new study mirrors previous magnetic resonance imaging (MRI) studies she and her colleagues published in 2005 showing a partial normalization of chemicals in selected brain regions after one year of methamphetamine abstinence.

"Together, the studies provide strong evidence that, eventually, meth abusers in recovery may be able to make better decisions and regain the impulse control that was lost during their drug use period," she said.

Salo said that more research is needed to determine just how the brain recovers from methamphetamine addiction and if behavioral treatments can hasten that recovery. She plans to continue neuroimaging studies to further define the brain functions affected by the drug. Her ultimate goal is to provide information essential to refining treatment programs for this population of drug users.

"Meth use worldwide is pandemic," she said, referring to the estimated 35 million people who have used the neurotoxic stimulant or similar drugs. "Recovery is difficult, but possible. The point of my research is to better understand the neural and behavioral consequences of this toxic drug along with the brain and behavior changes that are possible with long-term abstinence."

Source : University of California - Davis - Health System

Повреждения ДНК и марихуана

2009-06-19T19:41:00.000+03:00

Однако! http://www.biologynews.net/archives/2009/06/16/cannabis_alters_human_dna_new_study.html
A new study published by University of Leicester researchers has found "convincing evidence" that cannabis smoke damages DNA in ways that could potentially increase the risk of cancer development in humans.
Using a newly developed highly sensitive liquid chromatography-tandem mass spectrometry method, the University of Leicester scientists found clear indication that cannabis smoke damages DNA, under laboratory conditions.
They have now published the findings in the journal Chemical Research in Toxicology1.
The research was carried out by Rajinder Singh, Jatinderpal Sandhu, Balvinder Kaur, Tina Juren, William P. Steward, Dan Segerback and Peter B. Farmer from the Cancer Biomarkers and Prevention Group, Department of Cancer Studies and Molecular Medicine and Karolinska Institute, Sweden.
Raj Singh said: "Parts of the plant Cannabis sativa, also known as marijuana, ganja, and various street names, are commonly smoked as a recreational drug, although its use for such purposes is illegal in many countries.
"There have been many studies on the toxicity of tobacco smoke. It is known that tobacco smoke contains 4000 chemicals of which 60 are classed as carcinogens. Cannabis in contrast has not been so well studied. It is less combustible than tobacco and is often mixed with tobacco in use. Cannabis smoke contains 400 compounds including 60 cannabinoids. However, because of its lower combustibility it contains 50% more carcinogenic polycyclic aromatic hydrocarbons including naphthalene, benzanthracene, and benzopyrene, than tobacco smoke."
Writing in the journal Chemical Research in Toxicology, the scientists describe the development of a mass spectrometry method that provides a clear indication that cannabis smoke damages DNA, under laboratory conditions.
The authors added: "It is well known that toxic substances in tobacco smoke can damage DNA and increase the risk of lung and other cancers. Scientists were unsure though whether cannabis smoke would have the same effect. Our research has focused on the toxicity of acetaldehyde, which is present in both tobacco and cannabis."
The researchers add that the ability of cannabis smoke to damage DNA has significant human health implications especially as users tend to inhale more deeply than cigarette smokers, which increases respiratory burden. "The smoking of 3-4 cannabis cigarettes a day is associated with the same degree of damage to bronchial mucus membranes as 20 or more tobacco cigarettes a day," the team adds.
"These results provide evidence for the DNA damaging potential of cannabis smoke," the researchers conclude, "implying that the consumption of cannabis cigarettes may be detrimental to human health with the possibility to initiate cancer development."
Source : University of Leicester

Продолжительность жизни и окислительный стресс

2009-06-19T19:04:00.001+03:00

Такой вот спорный вопрос - этот окислительный стресс... Новая инфа на http://www.scienceblog.com/cms/how-oxidative-stress-may-help-prolong-life-21533.html
Oxidative stress has been linked to aging, cancer and other diseases in humans. Paradoxically, researchers have suggested that small exposure to oxidative conditions may actually offer protection from acute doses. Now, scientists at the University of California, San Diego, have discovered the gene responsible for this effect. Their study, published in PLoS Genetics on May 29, explains the underlying mechanism of the process that prevents cellular damage by reactive oxygen species (ROS).
"We may drink pomegranate juice to protect our bodies from so-called 'free radicals' or look at restricting calorie intake to extend our lifespan," said Trey Ideker, PhD, chief of the Division of Genetics in the Department of Medicine at UC San Diego's School of Medicine and professor of bioengineering at the Jacobs School of Engineering. "But our study suggests why humans may actually be able to prolong the aging process by regularly exposing our bodies to minimal amounts of oxidants."
Reactive oxygen species (ROS), ions that form as a natural byproduct of the metabolism of oxygen, play important roles in cell signaling. These very small molecules include oxygen ions, free radicals and peroxides. However, during times of environmental stress (for example, ultraviolet radiation or heat or chemical exposure), ROS levels can increase dramatically. This can result in significant damage to cellular damage to DNA, RNA and proteins ? cumulating in an effect called oxidative stress.
One major contributor to oxidative stress is hydrogen peroxide, converted from a type of free radical that leaks from the mitochondria as it produces energy. While the cell has ways to help minimize the damaging effects of hydrogen peroxide by converting it to oxygen and water, this conversion isn't 100 percent successful.
Ideker and first author Ryan Kelley used the rich functional genomics toolbox of yeast to identify pathways involved in the cell's adaption to hydrogen peroxide. Adaption (or hormesis) is an effect where a toxic substance acts like a stimulant in small doses, but is an inhibitor in large doses.
To shed light on the molecular mechanisms of adaptation, Ideker and Kelley designed a way to identify genes involved in adaptation to hydrogen peroxide. They elicited adaptation by pre-treating cells with a mild dose of hydrogen peroxide, followed by a high dose. They observed that the cells undergoing this adaptation protocol exhibited a smaller reduction in viability than cells exposed to only an acute treatment protocol (in which about half of the cells died.)
To figure out which genes might control this adaptation mechanism, Kelley and Ideker ran a series of experiments in which cells were forced to adapt while each gene in the genome was removed, one by one ? covering a total of nearly 5,000 genes. By systematically removing genes, they identified a novel factor called Mga2 ? and discovered that this transcription factor is essential for adaptation.
"This was a surprise, because Mga2 is found at the control point of a completely different pathway than those which respond to acute exposure of oxidative agents," said Ideker. "This second pathway is only active at lower doses of oxidation."
This finding may explain recent studies suggesting that eating less may, in fact, raise ROS levels ? and, in doing so, provide protection from acute doses of oxidants. This is counter to the hypothesis that caloric restriction extends lifespan in some species because it reduces ROS produced as a by-product of the energy regenerated by mitochondria.
"It may be that adaption to oxidative stress is the main factor responsible for the lifespan-expanding effects of caloric restriction," said Ideker. "Our next step is to figure out how Mga2 works to create a separate pathway ? to discover the upstream mechanism that senses low doses of oxidation and triggers a protective mechanism downstream." Further efforts to understand this process may have broad implications on models of aging and disease.
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This work was supported by a grant from the National Institute of Environmental Health Sciences. Ideker is a David and Lucille Packard Fellow.

О счастье и мозге

2009-06-05T15:04:00.000+03:00

Отличная статья на http://www.scienceblog.com/cms/blog/5634-happiness-%E2%80%93-theory-how-our-brains-lie-us-21534.html

Happiness – A Theory: How our Brains Lie to Us

May 29, 2009
The dialectic between descent with modification and the expanded cortex of the mammalian brain appears to have led to a kind of “house of mirrors” in humans. The smarter we get, it seems, the more we believe in our perceptions, while our brains work overtime to concoct a version of reality divorced from the evidence.
As part of the tangle of sophisticated circuitry enabled by our expanded cortex, we are able to associate any one thing with virtually any other thing, creating for ourselves an illusion of passive observation of what is actually happening in our present-time experience. We think of our brains as truth-seeking devices, but they deceive us without respite, and in staggeringly sophisticated ways.
Vision, for instance, is a projection of our minds, rather than the passive process that our brains might have us believe. Memory is fraught with error, but we adopt a false recollection with the fervor of a loving mother toward her child. We strive to acquire multiple choices, but we thrive where there are very few choices to be made, and suffer where there is a profusion. We are willing to diminish our own resources in order to punish someone we perceive as acting unfairly. We divide our fellows into “us” and “them” with regularity, despite the evidence that, in every meaningful way, we are just the same. We fret over a perceived threat that is little more than a dissenting opinion – i.e., something that would make us wiser, if we gave it shrift. We ruminate over real and imagined negatives, traumatizing ourselves more than would ever occur if we simply dealt with adversity as it arose. We set for ourselves the impossible goal of changing another person, then fall into a funk as the futility of the venture becomes apparent. We consider ourselves to be right in demanding that the world be different than it is. We perceive ourselves as victims, where the overwhelming evidence is that we are being treated to a truly unique experience in the universe. We expend energy in loathing others, when the evidence is that doing so is like taking poison. We think we are thinking when we have the perception that we are thinking, where the evidence is that our brains are whirring away 24/7, primarily in ways to which we have no access.
Recognizing that our brains lie – that we must cultivate a healthy skepticism of our own mental processes – is an important step in the pursuit of happiness.

Оксидативный стресс - подробности влияния

2009-06-05T15:02:00.001+03:00

Я, как обычно, отслеживаю новости об окислительном стрессе. Вот - очередная: http://www.scientificblogging.com/news_articles/oxidative_stress_linked_aging_cancer_and_now_longer_life
Oxidative stress has been linked to aging, cancer and other diseases in humans. Paradoxically, researchers have suggested that small exposure to oxidative conditions may actually offer protection from acute doses. Now, scientists at the University of California, San Diego, have discovered the gene responsible for this effect. Their study, published in PLoS Genetics on May 29, explains the underlying mechanism of the process that prevents cellular damage by reactive oxygen species (ROS).
"We may drink pomegranate juice to protect our bodies from so-called 'free radicals' or look at restricting calorie intake to extend our lifespan," said Trey Ideker, PhD, chief of the Division of Genetics in the Department of Medicine at UC San Diego's School of Medicine and professor of bioengineering at the Jacobs School of Engineering. "But our study suggests why humans may actually be able to prolong the aging process by regularly exposing our bodies to minimal amounts of oxidants."
Reactive oxygen species (ROS), ions that form as a natural byproduct of the metabolism of oxygen, play important roles in cell signaling. These very small molecules include oxygen ions, free radicals and peroxides. However, during times of environmental stress (for example, ultraviolet radiation or heat or chemical exposure), ROS levels can increase dramatically. This can result in significant damage to cellular damage to DNA, RNA and proteins – cumulating in an effect called oxidative stress.
One major contributor to oxidative stress is hydrogen peroxide, converted from a type of free radical that leaks from the mitochondria as it produces energy. While the cell has ways to help minimize the damaging effects of hydrogen peroxide by converting it to oxygen and water, this conversion isn't 100 percent successful.
Ideker and first author Ryan Kelley used the rich functional genomics toolbox of yeast to identify pathways involved in the cell's adaption to hydrogen peroxide. Adaption (or hormesis) is an effect where a toxic substance acts like a stimulant in small doses, but is an inhibitor in large doses.
To shed light on the molecular mechanisms of adaptation, Ideker and Kelley designed a way to identify genes involved in adaptation to hydrogen peroxide. They elicited adaptation by pre-treating cells with a mild dose of hydrogen peroxide, followed by a high dose. They observed that the cells undergoing this adaptation protocol exhibited a smaller reduction in viability than cells exposed to only an acute treatment protocol (in which about half of the cells died.)
To figure out which genes might control this adaptation mechanism, Kelley and Ideker ran a series of experiments in which cells were forced to adapt while each gene in the genome was removed, one by one – covering a total of nearly 5,000 genes. By systematically removing genes, they identified a novel factor called Mga2 – and discovered that this transcription factor is essential for adaptation.
"This was a surprise, because Mga2 is found at the control point of a completely different pathway than those which respond to acute exposure of oxidative agents," said Ideker. "This second pathway is only active at lower doses of oxidation."
This finding may explain recent studies suggesting that eating less may, in fact, raise ROS levels – and, in doing so, provide protection from acute doses of oxidants. This is counter to the hypothesis that caloric restriction extends lifespan in some species because it reduces ROS produced as a by-product of the energy regenerated by mitochondria.
"It may be that adaption to oxidative stress is the main factor responsible for the lifespan-expanding effects of caloric restriction," said Ideker. "Our next step is to figure out how Mga2 works to create a separate pathway – to discover the upstream mechanism that senses low doses of oxidation and triggers a protective mechanism downstream." Further efforts to understand this process may have broad implications on models of aging and disease.
This work was supported by a grant from the National Institute of Environmental Health Sciences. Ideker is a David and Lucille Packard Fellow.
Kelley R, Ideker T (2009) Genome-Wide Fitness and Expression Profiling Implicate Mga2 in Adaptation to Hydrogen Peroxide. PLoS Genet 5(5): e1000488. doi:10.1371/journal.pgen.1000488

Новости о влиянии кокаина на допаминовый метаболизм

2009-05-29T18:20:00.000+03:00

Очень интересно: http://www.eurekalert.org/pub_releases/2009-05/muhc-cpa051909.php
Contact: Isabelle Klingisabelle.kling@muhc.mcgill.ca514-843-1560McGill University Health Centre
Cocaine: Perceived as a reward by the brain?
Researchers at the MNI and the MUHC open up a new path for cocaine addiction research
This release is available in French.
Montreal, May 19th 2009 - Cocaine is one of the oldest drugs known to humans, and its abuse has become widespread since the end of the 19th century. At the same time, we know rather little about its effects on the human brain or the mechanisms that lead to cocaine addiction. The latest article by Dr. Marco Leyton, of the Montreal Neurological Institute (MNI), McGill University and the McGill University Health Centre, which was published in the journal Biological Psychiatry on May 15, 2009, not only demonstrates a link between cocaine and the reward circuits in the brain but also associates the susceptibility to addiction with these mechanisms.
The results of this study show that sniffing cocaine triggers high levels of dopamine secretion in a central region of the brain called the striatum. Dopamine is known to play a critical role in the brain's response to reward as well as in its response to addictive drugs.
This study was carried out in ten non-addicted users of cocaine, all of whom sniffed cocaine on one test day and placebo powder on another. Participants underwent blood tests before and after taking the drug, and dopamine release in the brain was measured using PET scans.
"The ability of cocaine to activate dopamine release varies markedly from person to person. Our study suggests that this is related to how much of the drug the person consumed in the past," explained Dr. Leyton. The more cocaine someone has used in his or her lifetime, the more the brain will secrete dopamine during subsequent cocaine use. "It's possible therefore that the intensity of the reward-circuit response is related to increased susceptibility to addiction," stated Dr. Leyton.
Although the relationship between the intensity of dopamine secretion and the frequency of drug use has been demonstrated, researchers still do not fully understand its mechanism of action. Is it the repeated stimulation of the reward circuit that leads to addiction, or is it an inherent sensitivity to addiction that leads to the increased secretion of dopamine? This question is not easy to answer, especially since other factors come into play, such as other aspects of the subject's personal history.
Whatever the answer, the relationship between dopamine and cocaine means that this hormone could be a potential target for treatment against addiction. More research is required before treatments are available, but this study opens a new door in this direction.

Счастливая наследственность?

2009-05-25T19:08:00.000+03:00

Прочитано на http://www.scientificblogging.com/news_articles/can_you_inherit_happiness_endorphins_and_biochemistry_inheritance
As if you need another reason for parental guilt, a new article in Bioscience Hypotheses speculates that our feelings could impact our reproduction and affect our children.

Dr Alberto Halabe Bucay of Research Center Halabe and Darwich, Mexico, suggests that a wide range of chemicals that our brain generates when we are in different moods could affect 'germ cells' (eggs and sperm), the cells that ultimately produce the next generation. Such natural chemicals could affect the way that specific genes are expressed in the germ cells, and hence how a child develops.

In his article Halabe suggested that the hormones and chemicals resulting from happiness, depression and other mental states can affect our eggs and sperm, resulting in lasting changes in our children at the time of their conception.

Brain chemicals such as endorphins, and drugs, such as marijuana and heroin are known to have significant effects on sperm and eggs, altering the patterns of genes that are active in them.

"It is well known, of course, that parental behavior affects children, and that the genes that a child gets from its parents help shape that child's character." said Dr. Halabe Bucay. "My paper suggests a way that the parent's psychology before conception can actually affect the child's genes."

"This is an intriguing idea" commented Dr. William Bains, Editor of Bioscience Hypotheses. "We wanted to publish it to see what other scientists thought, and whether others had data that could support or disprove it. That is what our journal is for, to stimulate debate about new ideas, the more groundbreaking, the better."

Article: Alberto Halabe Bucay, 'Endorphins, personality, and inheritance: Establishing the biochemical bases of inheritance', Bioscience Hypotheses, In Press, Corrected Proof, Available online 7 May 2009 doi:10.1016/j.bihy.2009.03.003

Новое о механизмах эффектов экстази

2009-05-25T19:00:00.002+03:00

Очень интересно... Как всегда грамотно написано на http://scienceblogs.com/drugmonkey/2009/05/waitcannabis_potentiates_the_e.php

Wait...Cannabis potentiates the effects of Ecstasy?

Category: Cannabis • MDMA
Posted on: May 15, 2009 5:35 PM, by DrugMonkey

Along with alcohol, caffeine and nicotine, the most-active ingredient in cannabis (Δ9-THC; "THC") is frequently co-ingested with MDMA by the Ecstasy user. There are, in fact, some suggestions that cannabis may be consumed in some cases specifically to assist with modulating the MDMA high.

Now, those that are aware of the tetrad test for cannabinoid action (necessary back before the first cannabinoid receptor was cloned in the early 90s) might think to themselves of a specific protective effect. One of the hallmarks of THC is that it reduces body temperature in rats. So if one of the problems with MDMA is that it results in high body temperature, it might be convenient if smoking a little dope had an action that reversed this physiological outcome.

This was supported by a paper by Morley et al (2004) which reported that yes indeed, if you inject a rat with 2.5 mg/kg THC i.p. it completely blocks the tympanic temperature elevation produced by 5 mg/kg MDMA i.p.

A recent study in humans suggests that caution is warranted.

Cannabis Coadministration Potentiates the Effects of "Ecstasy" on Heart Rate and Temperature in Humans. Dumont G, Kramers C, Sweep F, Touw D, van Hasselt J, de Kam M, van Gerven J, Buitelaar J, Verkes R. Clin Pharmacol Ther. 2009 May 13.

This study reports on the effects of 100 mg oral MDMA, three inhalations of about 6 mg THC (spaced at 90 min) and the combination in 13 human subjects. Plasma kinetics for the exogenous drugs, for norepinephrine and epinephrine and heart rate are reported. One of the more interesting bits, however, is reported in the following figure.

Tympanic temperature was increased by oral consumption of MDMA, reaching a peak about 90 minutes after ingestion (consistent with the plasma peak), as one might expect*. inhaling vaporized THC did not block this effect. The first inhalation of THC (timed to pill ingestion) looks to have delayed the onset of the temperature increase. However the second inhalation did not induce further delay and temperature ultimately reached a peak change approximately equal to the one after MDMA alone. The elevated temperature was sustained up to the end of the 300 min observation interval in the THC-MDMA combined condition compared with MDMA alone.

Hmm. Looking for differences here. The biggest thing would seem to be that this level of THC inhalation did not produce a reduction in body temperature by itself in humans. The doses that decrease body temperature in rodents are fairly high ones so what were these humans receiving? Well, the inhalation procedure in this study resulted in plasma levels of 60-80 ng/ml. This NHTSA site claims that 100-200 ng/ml of THC are "routinely" observed in cannabis smokers. See this, this, this for confirmation. So the present study was perhaps on the low side of things, but then speculating exactly how much cannabis an Ecstasy user might smoke is.....well, speculative. And the study did report about a 20-30 bpm elevation in heart rate after THC inhalation that appeared to be independent of MDMA (which itself elevated heart rate by about 20-30 bpm). So it was certainly in the range of physiological relevance.

Give that this study is in humans, given the doses seem more in line with what would be expected in the user population, I'd have to put more confidence in this study than in the Morley et al (2004) rat paper. Thus it appears unlikely that cannabis smoking in the recreational Ecstasy user provides any protection against MDMA-induced hyperthermia.

The prolongation of the elevated body temperature that was the excuse for using "Potentiates" in the title? Doesn't support a strong conclusion at this stage but it certainly brings up some other scenarios for risk with subsequent dosing.

__
*Actually it is not entirely true that one might expect this. This is well below the doses used in the clinical trials. One of the initial results seems to imply not just that mean temp did not significantly increase but that no individual experienced a 1 deg Celsius increase in temperature. Liechti and Vollenweider (2000) reported no effect of 1.5 mg/kg oral MDMA on axillary temperature. Nevertheless in a dedicated experiment using an ingested remote device to measure gastric ("core") temperature Freedman and colleagues (2005) found that 2 mg/kg oral MDMA did increase body temperature under cool and warm laboratory conditions.

Курение поможет аллергикам???

2009-05-15T02:38:00.000+03:00

Сенсационно! http://www.scientificblogging.com/news_articles/solution_allergies_cigarettes:
Smoking is bad for you, but it can also help with allergies, according to a new study which says that cigarette smoke can prevent allergies by decreasing the reaction of immune cells to allergens.

Smoking can cause lung cancer, pulmonary disease, and can even affect how the body fights infections but along with many harmful effects, smoking cigarettes has a surprising benefit: cigarettes can protect smokers from certain types of allergies. The new study says that cigarette smoke decreases the allergic response by inhibiting the activity of mast cells, the major players in the immune system's response to allergens.

Researchers at Utrecht University in the Netherlands found that treatment of primary cultured murine mast cells with a cigarette smoke-infused solution and activated with IgE and antigen or lipopolysaccharide (LPS) prevented the release of inflammation-inducing proteins in response to allergens, without affecting other mast cell immune functions.

The mast cells used in the study were derived from mice, but they say it is likely that the same anti-allergy effect will hold true in humans. While taking up smoking to cure allergies is unwise, Thomson concludes that the findings presented in this study are "consistent with a dampening of allergic responses in smokers."

Article: Mortaz E, Folkerts G, Engels F, Nijkamp FP, Redegeld FA, 'Cigarette smoke suppresses in vitro allergic activation of mouse mast cells', Clin Exp Allergy. 2009 May;39(5):679-87. Epub 2009 Mar 2

Больше думаем - сложнее выбор

2009-05-14T18:02:00.001+03:00

Too much information: Process thinking can lead to difficult choices - отличная статья на http://www.eurekalert.org/pub_releases/2009-05/uocp-tmi051209.php

Choosing among products can be more difficult if you tend to think more about the process of using an item rather than the outcome of the purchase, according to a new study in the Journal of Consumer Research.

"Marketers often try to tempt consumers to buy their products by encouraging them to imagine themselves using the product," write authors Debora Viana Thompson (Georgetown University), Rebecca W. Hamilton (University of Maryland, College Park), and Petia K. Petrova (Dartmouth College). But this "process-oriented" thinking can lead to confusion.

"In this research, we show that when consumers are choosing among products, focusing on the process of using a product (versus on the outcomes) can increase decision difficulty and hinder consumers' motivation to subsequently implement their choices," the authors explain.

Consumer decisions often involve trade-offs between means and end benefits, such as weighing quality versus price, rewards versus risks, or enjoyment versus effort. Process-oriented thinkers tend to focus on both ends and means, making decisions more difficult.

For example, in one experiment, participants were asked to choose between a small apartment that required a short commute and one that was larger but required a longer commute. The researchers instructed participants to either think about how living in the apartment would affect their daily routine and habits (process-oriented thinking) or to think about what they would gain from living in the apartment (outcome-oriented thinking). "Process-oriented participants thought about both the size of the apartment and the length of the commute, were less likely to choose the larger apartment, and experienced more difficulty making the choice," the authors write.

"This experience of difficulty can have various negative consequences for consumers. It can lower consumer satisfaction with the decision process, increase willingness to postpone choices, increase the likelihood they will change their minds later and switch to a different option, and reduce motivation to implement the decision," the authors conclude.

###

Debora Viana Thompson, Rebecca W. Hamilton, and Petia K. Petrova. "When Mental Simulation Hinders Behavior: The Effects of Process-Oriented Thinking on Decision Difficulty and Performance." Journal of Consumer Research: December 2009 (published online April 9, 2009).

О влиянии кокаина на экспрессию генов

2009-05-14T00:49:00.000+03:00

Новые исследования описаны на http://www.scientificblogging.com/news_articles/cocaine_regulates_gene_expression_and_has_longlasting_impact_behavior
New research sheds light on how cocaine regulates gene expression in a crucial reward region of the brain to elicit long-lasting changes in behavior. The study in Neuron provides insight into the molecular pathways regulated by cocaine and may lead to new strategies for battling drug addiction.

It is well established that addictive drugs induce persistent changes in the brain's reward circuits. Previous research has indicated that addiction to drugs such as cocaine is associated with altered gene expression in the nucleus accumbens (NAc), a region of the brain that is involved in motivation, pleasure, and reward.

"Although we have known for some time that changes in gene expression contribute to the long-lasting regulation of the brain's reward circuitry that is seen during drug addiction, how those specific genes are regulated is not well understood," explains senior study author, Dr. Eric J. Nestler from the Department of Neuroscience at the Mount Sinai School of Medicine.

Dr. Nestler and colleagues combined sophisticated and highly sensitive genetic isolation and screening techniques to study regulation of gene transcription in the mouse NAc, including regulation of chromatin structure, after repeated administration of cocaine. The results of this novel analysis significantly refined the understanding of cocaine-regulated gene transcription in general, and advanced knowledge of the specific role of two transcription factors known to play a prominent role in cocaine-induced addiction.

The researchers also identified a previously unrecognized family of genes, called the sirtuins, as being involved in cocaine addiction in the NAc. Chronic cocaine administration was linked with an increase in sirtuin gene transcription while increased sirtuin activity in NAc neurons was associated with a potentiation of the rewarding effects of cocaine. Importantly, pharmacological inhibition of sirtuins in the NAc reduced the rewarding effects of cocaine and the motivation to self-administer the drug.

Taken together, the results identify a subset of genes that are highly likely to be targets of cocaine and shed light on the specific mechanisms that underlie cocaine-induced changes in the NAc. "Our findings underscore the vast clinical potential of the many new gene targets identified in this study for the development of more effective treatments of cocaine and potentially other drug addictions," concludes Dr. Nestler.

The researchers include William Renthal, The University of Texas Southwestern Medical Center at Dallas, Dallas, TX; Arvind Kumar, The University of Texas Southwestern Medical Center at Dallas, Dallas, TX; Guanghua Xiao, The University of Texas Southwestern Medical Center at Dallas, Dallas, TX; Matthew Wilkinson, Mount Sinai School of Medicine, New York, NY; Herbert E. Covington III, Mount Sinai School of Medicine, New York, NY; Ian Maze, Mount Sinai School of Medicine, New York, NY; Devanjan Sikder, The University of Texas Southwestern Medical Center at Dallas, Dallas, TX; Alfred J. Robison, Mount Sinai School of Medicine, New York, NY; Quincey LaPlant, The University of Texas Southwestern Medical Center at Dallas, Dallas, TX, Mount Sinai School of Medicine, New York, NY; David M. Dietz, Mount Sinai School of Medicine, New York, NY; Scott J. Russo, Mount Sinai School of Medicine, New York, NY; Vincent Vialou, Mount Sinai School of Medicine, New York, NY; Sumana Chakravarty, The University of Texas Southwestern Medical Center at Dallas, Dallas, TX; Thomas J. Kodadek, The University of Texas Southwestern Medical Center at Dallas, Dallas, TX; Ashley Stack, Florida State University, Tallahassee, FL; Mohamed Kabbaj, Florida State University, Tallahassee, FL; and Eric J. Nestler, The University of Texas Southwestern Medical Center at Dallas, Dallas, TX, Mount Sinai School of Medicine, New York, NY.