27.05.2011

Клетки кожи могут думать?

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

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

Антидепрессанты и диабет

Привычные антидепрессанты в некоторых комбинациях приводят к развитию диабета! Читаем подробнее на:
Common drug combo increases diabetes risk - health - 26 May 2011 - New Scientist

16.05.2011

Юмороват с функциями

Баян, да. Но хороший:

14.05.2011

Плацебо-новости

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/ 

Elleven%20Project