Thursday, May 8, 2008
Wednesday, May 7, 2008
Tuesday, May 6, 2008
Mouse Skin Cells Reprogrammed to Act Like Embryonic Stem Cells
Heart and blood cells can be grown from reprogrammed mouse skin cells, report University of California, Los Angeles (UCLA) researchers in the journal Stem Cells. The researchers say this is the first demonstration that stem cells from reprogrammed skin can be used to generate three types of heart and blood cell, including beating heart tissue. These could theoretically be used to repair damage following disease or heart attack.
Skin cells are transformed into stem cells using a combination of genetic factors. UCLA researchers were among those to develop the technique last June. The cells, known as induced pluripotent stem (iPS) cells, resemble embryonic stem (ES) cells but do not require the use of human eggs or embryos in their development. A Canadian team previously generated beating heart tissue using embryonic stem cells.
Robb MacLellan and his team grew iPS cells on a protein matrix designed to promote the transition of stem cells into cardiovascular progenitors. These specialised cells were then treated under different conditions to direct development into three types of cardiovascular tissue: cardiomyocytes, or mature heart muscle cells that control heartbeat, endothelial cells, which form rudimentary blood vessels, and vascular smooth muscle cells, the specialized cells that line blood vessel walls. The cardiomyocytes began to beat once mature. 'I believe iPS cells address many of the shortcomings of human embryonic stem cells and are the future of regenerative medicine', said MacLellan, senior study author and associate professor of cardiology and physiology.
If iPS cell-derived cardiovascular tissues can be used to treat heart disease or damage, they could potentially allow personalised treatment following, for instance, a heart attack. A patient's own skin cells could provide iPS cells that in turn would be used to develop new heart tissue, which would be genetically matched to the patient thus avoiding immune rejection. 'Our hope is that, based on this work in mice, we can show that similar cardiovascular progenitor cells can be found in human iPS cells and, using a similar strategy, that we can isolate the progenitor cells and differentiate them into the cells types found in the human heart', MacLellan said.
Work is underway at UCLA to determine whether the techniques established in mice can be used in humans. Although human applications of this research remain distant, it seems that iPS cells could provide regenerative treatment in future without the need for the controversial use of human eggs and embryos.
Skin cells are transformed into stem cells using a combination of genetic factors. UCLA researchers were among those to develop the technique last June. The cells, known as induced pluripotent stem (iPS) cells, resemble embryonic stem (ES) cells but do not require the use of human eggs or embryos in their development. A Canadian team previously generated beating heart tissue using embryonic stem cells.
Robb MacLellan and his team grew iPS cells on a protein matrix designed to promote the transition of stem cells into cardiovascular progenitors. These specialised cells were then treated under different conditions to direct development into three types of cardiovascular tissue: cardiomyocytes, or mature heart muscle cells that control heartbeat, endothelial cells, which form rudimentary blood vessels, and vascular smooth muscle cells, the specialized cells that line blood vessel walls. The cardiomyocytes began to beat once mature. 'I believe iPS cells address many of the shortcomings of human embryonic stem cells and are the future of regenerative medicine', said MacLellan, senior study author and associate professor of cardiology and physiology.
If iPS cell-derived cardiovascular tissues can be used to treat heart disease or damage, they could potentially allow personalised treatment following, for instance, a heart attack. A patient's own skin cells could provide iPS cells that in turn would be used to develop new heart tissue, which would be genetically matched to the patient thus avoiding immune rejection. 'Our hope is that, based on this work in mice, we can show that similar cardiovascular progenitor cells can be found in human iPS cells and, using a similar strategy, that we can isolate the progenitor cells and differentiate them into the cells types found in the human heart', MacLellan said.
Work is underway at UCLA to determine whether the techniques established in mice can be used in humans. Although human applications of this research remain distant, it seems that iPS cells could provide regenerative treatment in future without the need for the controversial use of human eggs and embryos.
Monday, May 5, 2008
Your mum, not IVF, determines age of menopause
A group of researchers at the Bourn Hall Clinic, Queensland University of Technology and the Weill Medical College of Cornell University, New York, have concluded that IVF treatment does not hasten the onset of the menopause or the severity of symptoms, having investigated the first generation of IVF patients.
Senior research scientist Dr Kay Elder and her team examined women who were treated at Bourn Hall Clinic in the UK between 1981 and 1994. When IVF treatment was first used there were worries that the hormones used to stimulate the ovaries to generate the eggs required might trigger an early menopause, by 'using up' a woman's eggs too quickly.
However, through theory and biological observations on 700 women, the age of onset of menopause was found to be more linked to maternal history than IVF treatment, and there was no increase in perimenopausal symptoms. Dr Elder said of the concerns that 'it was unknown territory in those days. Although all the studies showed that the treatment was safe, it was ground-breaking and we couldn't predict the potential long-term impacts'.
'This is a question patients often ask - and it's very useful to finally have a scientific study to point to which offers them reassurance that IVF will not affect timing or severity of the menopause,' she said.
Meanwhile, a group of researchers publishing in JCEM, a publication of The Endocrine Society, claims to have discovered a way to predict a woman's age at menopause more accurately. The study shows that anti-Mullerian hormone (AMH) levels in the blood can reflect how many follicles are present in a woman's ovaries. The stock of follicles ensures monthly ovulations, and depletion of the stock leads to menopause. Dr Jeroen van Disseldorp and Dr Frank Broekmans of the University Medical Centre Utrecht in the Netherlands said that 'knowing when menopause may occur could greatly impact childbearing decisions and our findings show that such knowledge may now be available from AMH levels'.
Senior research scientist Dr Kay Elder and her team examined women who were treated at Bourn Hall Clinic in the UK between 1981 and 1994. When IVF treatment was first used there were worries that the hormones used to stimulate the ovaries to generate the eggs required might trigger an early menopause, by 'using up' a woman's eggs too quickly.
However, through theory and biological observations on 700 women, the age of onset of menopause was found to be more linked to maternal history than IVF treatment, and there was no increase in perimenopausal symptoms. Dr Elder said of the concerns that 'it was unknown territory in those days. Although all the studies showed that the treatment was safe, it was ground-breaking and we couldn't predict the potential long-term impacts'.
'This is a question patients often ask - and it's very useful to finally have a scientific study to point to which offers them reassurance that IVF will not affect timing or severity of the menopause,' she said.
Meanwhile, a group of researchers publishing in JCEM, a publication of The Endocrine Society, claims to have discovered a way to predict a woman's age at menopause more accurately. The study shows that anti-Mullerian hormone (AMH) levels in the blood can reflect how many follicles are present in a woman's ovaries. The stock of follicles ensures monthly ovulations, and depletion of the stock leads to menopause. Dr Jeroen van Disseldorp and Dr Frank Broekmans of the University Medical Centre Utrecht in the Netherlands said that 'knowing when menopause may occur could greatly impact childbearing decisions and our findings show that such knowledge may now be available from AMH levels'.
Sunday, May 4, 2008
Saturday, May 3, 2008
Friday, May 2, 2008
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