Об эффективности обогащённой тромбоцитами плазмы

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:

1. 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.)
2. What are possible side effects? (Examples include increased pain or inflammation at the injection site.)
3. How many injections will I receive? (Several studies have reported using multiple injections, but the benefit of this is unknown.)
4. 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.)
5. 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

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

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!

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

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