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Lab-grown egg cells set to revolutionise fertility People’s ‘niceness’ may reside in their genes TRENDS
US, Russian scientists launch ice seal survey In cancer science, many ‘discoveries’ don't hold up Prof Yash
Pal THIS UNIVERSE |
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Lab-grown egg cells set to revolutionise fertility
THE first human egg cells that have been grown entirely in the laboratory from stem cells could be fertilised later this year in a development that will revolutionise fertility treatment and might even lead to a reversal of the menopause in older women. Scientists are about to request a licence from the UK fertility watchdog to fertilise the eggs as part of a series of tests to generate an unlimited supply of human eggs, a breakthrough that could help infertile women to have babies as well as making women as fertile in later life as men. Producing human eggs from stem cells would also open up the possibility of replenishing the ovaries of older women so that they do not suffer the age-related health problems associated with the menopause, from osteoporosis to heart disease. Some scientists are even suggesting the possibility of producing an “elixir of youth” for women, where the menopause is eradicated and older women will retain the health they enjoyed when younger. Researchers at Edinburgh University are working with a team from Harvard Medical School in Boston to be the first in the world to produce mature human eggs from stem cells isolated from human ovarian tissue. Until now, it has only been possible to isolate a relatively small number of mature human egg cells directly from the ovaries of women who have been stimulated with hormones. This technical limitation has led to an acute shortage of human eggs, or “oocycts”, for IVF treatment as well as scientific research. The scientists want to fertilise the laboratory-grown egg cells with human sperm to prove that they are viable. Any resulting embryos will be studied for up to 14 days — the legal limit — to see if they are normal. These early embryos will not be transplanted into a woman’s womb because they will be deemed experimental material, but will either be frozen or allowed to perish. Evelyn Telfer, a reproductive biologist at Edinburgh University, has already informally approached the Human Fertilisation and Embryology Authority (HFEA) with a view to submitting a formal licence application within the next few weeks. “We hope to apply for a research license to do the fertilisation of the in vitro grown oocytes within the IVF unit at the Edinburgh Royal Infirmary,” Dr Telfer said. “Could the fertilisation take place this year? Yes, absolutely,” she said. Professor Richard Anderson of the MRC Centre for Reproductive Health, who will be in charge of the clinical aspects of the work, said: “The aim will be to demonstrate that the eggs that we’ve generated in vitro are competent to form embryos and that’s the best test that an egg is an egg.” Generating an unlimited supply of human eggs and the prospect of reversing the menopause was made possible by a series of breakthroughs led by Professor Jonathan Tilly of Harvard. In 2004 he astounded the world of reproductive biology by suggesting that there were active stem cells in the ovaries of mice that seemed capable of replenishing eggs throughout life. For half a century, a dogma of reproductive biology was that women are born with their full complement of egg cells which they gradually lose through life until they run out when they reach the menopause. “This age-old belief that females are given a fixed ‘bank account’ of eggs at birth is incorrect,” Professor Tilly said. “In fact, ovaries in adulthood are probably more closely matched to testes in adulthood in their capacity to make new germ cells, which are the special cells that give rise to sperm and eggs,“ he said. “Over the past 50 years, all the basic science, all the clinical work and all the clinical outcome was predicated on one simple belief, that is the oocyte pool, the early egg-cell pool in the ovaries was a fixed entity, and once those eggs were used up they cannot be renewed, replenished or replaced,“ he added. Last month, Professor Tilly published pioneering research showing that these stem cells exist in human ovaries and that they could be stimulated in the laboratory to grow into immature egg cells. He is collaborating with Dr Telfer, who was once sceptical of his research, because in Edinburgh she has pioneered a technique for growing immature eggs cells to the fully “ripened” stage when they can be fertilised. “It’s been fun to work with her because she’s been one of the most vocal critics of this work years ago and it’s great that she’s come about and changed her views,” Professor Tilly said. “I think personally (fertilising the first eggs) is do-able. I see no hurdles why it cannot be done this year,” he added. Dr Telfer added: “The important thing is that if you can show you can get ovarian stem cells from human ovary you then have the potential to do more for fertility preservation. “We have all the local ethical approval in place and we’re now looking at the process of the HFEA application. There is a push for us to do it now,” she added. — The Independent |
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People’s ‘niceness’ may reside in their genes
DNA may help explain why some people are nicer than others, according to researchers. A research by psychologists at the University at Buffalo and the University of California, Irvine, has found that at least part of the reason some people are kind and generous is because their genes nudge them toward it. The study, co-authored by Anneke Buffone of UB and E. Alison Holman of the University of California, Irvine, looked at the behaviour of study subjects who have versions of receptor genes for two hormones that, in laboratory and close relationship research, are associated with niceness. Previous laboratory studies have linked the hormones oxytocin and vasopressin to the way we treat one another, said Michel Poulin, Ph.D, Assistant Professor of Psychology at UB, who is the principal author of the study. In fact, they are known to make us nicer people, at least in close relationships. Oxytocin promotes maternal behaviour, for example, and in the lab, subjects exposed to the hormone demonstrate greater sociability. Poulin explained that hormones work by binding to our cells through receptors that come in different forms. There are several genes that control the function of oxytocin and vasopressin receptors. Subjects were surveyed as to their attitudes toward civic duty, other people and the world in general, and about their charitable activities. Among those surveyed, 711 subjects provided a sample of saliva for DNA analysis, which showed what form they had of the oxytocin and vasopressin receptors. “The study found that these genes combined with people's perceptions of the world as a more or less threatening place to predict generosity,” Poulin said.
— ANI |
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US, Russian scientists launch ice seal survey ANCHORAGE, Alaska: A team of US and Russian scientists has launched the biggest population survey to date of Bering Sea ice seals as federal authorities consider endangered species protections for the marine mammals, a US government spokeswoman said. As part of the project, which began this week, scientists are flying by plane at low altitude — just 800 to 1,000 feet above the surface — across 20,000 nautical miles of US and Russian waters, tracking the seals with infrared and digital cameras. In cancer science, many ‘discoveries’ don't hold up LONDON:
A former researcher at Amgen Inc has found that many basic studies on cancer-a high proportion of them from university labs-are unreliable, with grim consequences for producing new medicines in the future. During a decade as head of global cancer research at Amgen, C. Glenn Begley identified 53 "landmark" publications-papers in top journals, from reputable labs-for his team to reproduce. Begley sought to double-check the findings before trying to build on them for drug development.
— Reuters |
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THIS
UNIVERSE Can a bulb produce black light? It would be useful to first consider what we mean by black light. This is a rather confusing expression. Black usually denotes absence of light. The questioner refers to the possibility of a bulb that produces some light. No we cannot have light that is not light — meaning black. We can have a bulb that emits nothing or emits something that is not visible to our eyes. This should not be as difficult as it sounds, because most of possible radiations are not visible — they could be infrared, ultraviolet, X-ray, high-energy gama-ray or good old radio wave. Talking of a bulb that emits black light does not much sense, even if it is amusing. How does a tube light work? Our tube lights are usually narrow glass cylinders whose inner surface is coated with a phosphorescent material that gives good bright light when illuminated by ultraviolet radiation. The ultraviolet radiation is produced by an electric discharge in the tube, which contains mercury vapour at low pressure. When we turn on the light, the discharge is started with the help of an electrical system that produces a short high-voltage pulse. After the discharge begins, the electrode on the cathode is heated by the impact of mercury ions and the hot electrode goes on emitting electrons that sustain the discharge that produces the ultraviolet. It should be clear from this description of the working of a tube light that this light takes a little time or a few tries in coming up. So much so that this has given rise to a joke on people who are a little slow in getting the idea of a good joke. Some people call them as tube lights. Readers wanting to ask Prof Yash Pal
a question can e-mail him at palyash.pal@gmail.com |
