Tag Archives: Embryonic Stem Cells

Adult stem cells may lead to new infertility treatment

A special class of adult stem cells, known as human induced pluripotent stem (iPS) cells, has for the first time been reprogrammed into cells that develop into human eggs and sperm. The research, carried out by members of the University of California, Los Angeles (UCLA)’s Broad Stem Cell Research Center, was published in the January 27 online edition of the journal Stem Cells. Derived from adult body cells that have been engineered to return to an embryonic state, iPS cells have the ability to become every cell type in the human body – a characteristic they share with embryonic stem (ES) cells. In this study the iPS cells were coaxed into forming the germ line precursor cells that are capable of giving rise to sperm and eggs. ‘This finding could be important for people who are rendered infertile through disease or injury’. said Amander Clark, the senior author of the study. ‘We may, one day, be able to replace the germ cells that are lost, and these germ cells would be specific and genetically related to that patient’. Many infertile couples would see this process as preferable to using eggs or sperm from a donor who would then become one of the child’s genetic parents. However, Clark cautioned that scientists are still many years from offering treatments involving iPS cells to infertile patients. There are many uncertainties and dangers that need to be resolved. For example, the process of reprogramming involves using viruses to deliver genes to the cells, potentially increasing the likelihood of genetic abnormalities and cancers. Crucially, Clark’s team found that the germ line cells derived from iPS cells did not perform certain key regulatory processes as well as those generated from ES cells. The associated increased risk of chromosomal errors, or abnormal growth, could have serious health consequences for any child conceived using egg or sperm obtained in this way. Therefore Clark believes that it is vital that research using human ES cells continues. These cells can be derived from left over embryos used during in vitro fertilisation, and would otherwise be destroyed, yet their use is controversial and the topic remains fiercely debated.

Sources : Los Angeles Times, IVF News

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Sperm From Female Stem Cells

 

British scientists have created early-stage, human sperm from female stem cells, according to a news reportin New Scientist magazine. It is claimed that the research will pave the way for same sex couples to have children that are genetically their own. However, other scientists are sceptical that this procedure would ever be possible.
Professor Karim Nayernia at the University of Newcastle initially fertilised mice with sperm derived from embryonic stem cells (ESCs) in 2006, which gave rise to seven pups, six of which survived. In more recent work, he took human male stem cells from bone marrow and formed ‘spermatogonia’, primitive sperm cells that can form mature sperm cells by going through a process called meiosis. Nayernia has now apparently done the same using human female stem cells, work that has yet to be published.
The next stage in the process would be to make these primitive sperm cells undergo meiosis, which Nayernia claims he has started to do. The result could be that female eggs are fertilised by ‘female’ sperm, thereby eradicating the need for male gametes. However, Dr Robin Lovell-Badge, a stem cell expert at the National Institute of Medical Research in London, does not think the approach will work. He told the Telegraph newspaper that the ‘presence of two X chromosomes is incompatible with this. Moreover they need genes from the Y chromosome [from the male sperm] to go through meiosis. So they are at least double damned’. Safety issues have also been raised, since the mice pups in Nayernia’s initial study had health problems.
A Brazilian team of scientists lead by Dr Irina Kerkis at the Butantan Institute in Sao Paolo also claim to have made sperm and eggs from male mouse ESCs, and are currently starting to take the work into human cells. The research brings hope to people dealing with infertility, a problem that affects one in six couples, although scientists say the process is still in its infancy and treatments are a long way off.
There is also potential to use ‘induced pluripotent stem cells’, stem cells derived from human skin cells, as a starting point for the process. This could enable gay men to donate skin cells that would be used to create stem cells from which eggs could be formed. The eggs could then be fertilised using sperm from his partner, and placed in a surrogate mother.
Greg Aharonian, a patent analyst in the US, is trying to patent the technology behind ‘female’ sperm and ‘male’ eggs. A self-proclaimed ‘troublemaker’, he wants to undermine the argument that marriage should remain heterosexual because its main purpose is procreation.
The controversial developments have provoked mixed responses in the UK and US. Mike Judge from the Christian Institute faith group says that ‘children need male and a female role models’. Many religious groups still oppose gay marriage. Josephine Quintavalle, from the pro-life lobby group Comment on Reproductive Ethics, says: ‘we are looking at absurd solutions to very obscure situations and not addressing the main issue. Nobody is interested in looking at what is causing infertility – social reasons such as obesity, smoking and age’.

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Stem-Cell Tourism condemned

The increasing problem of ‘stem-cell tourism’ – patients travelling to developing countries seeking costly and unproven stem cell treatments – have prompted leading experts to join in an international effort to establish standards for the development of stem cell treatments. The 30-member committee, comprised of scientists and ethicists from 13 nations, was to release a draft guide at the International Society for Stem Cell Research (ISSCR) annual meeting in Philadelphia last week but discussions have delayed it. They now hope to have a draft ready in one month, said George Daley, president of the ISSCR, which created the task-force committee. The committee will also collaborate with patient groups to publish a shorter document of frequently asked questions to help explain the guidelines and assist individuals to evaluate the merits of advertised therapies.
The therapeutic benefit of stem cells – cells which can regenerate damaged tissue and organs – are still many years away. Daley told a news conference that he is particularly concerned that stem cell science in its infancy is ‘fertile ground for exploitation’ because so little is yet understood but the therapeutic potential is so great and ‘patients who are desperate will misunderstand the amount of progress in the field’ and become vulnerable to ‘snake oil’ ‘medical fraud’. ‘We need to be strong in condemning this kind of medical tourism’, agreed Olle Lindvall, committee co-chair and neurologist at the University of Lund in Sweden.
The guidelines will provide criteria for the characterisation and production of stem cells eventually intended for human transplantation as well as the level of evidence that should be required through lab and animal studies before conducting human clinical trials. While the guidelines are not legally binding, the members hope they will serve as regulatory guideposts for countries to translate into laws that protect patients from being swindled or harmed.
The only proven stem cell therapies are for blood disorders, certain cancers and rare immune deficiencies. Yet, a proliferation of internet websites offer costly stem-cell nostrums as cure-alls for conditions ranging from Parkinson’s disease, stroke and paralysis to anti-ageing treatments available in countries including China, Thailand and Costa Rica which Daley dismisses as ‘snake oil’. None of these therapies are scientifically proven to be safe and effective, according to Lindvall.
The numbers of individuals travelling for stem cell treatment is unknown but a team led by Timothy Caulfield at the University of Alberta ‘s Health Law Institute in Canada, surveyed 32 websites offering treatments – identified from the media and Google searches – and found that only one site described the procedure as experimental and 26 sites advertised it as being routine. Only four websites referred to peer-reviewed studies. Additionally, the treatments are expensive – 13 sites detailed prices and the average cost for a course of treatment is over INR 360,000 but if combined with cosmetic and lifestyle procedures offered then the figure increases to roughly INR 10,80,000. Insoo Hyun, a bioethicist at Case Western Reserve University in Ohio and co-chair of the committee agrees that a ‘strong statement’ is required and the wording of the draft in progress reflects this: ‘The ISSCR condemns the administration of stem cells or their direct derivatives to… patients as unproven medical innovation outside of a clinical trial, particularly when patients in these circumstances are charged for advertised medical services’. It is questionable whether these guidelines will really deter desperate individuals. Many advocacy groups offer patient guidelines and most countries, developing or otherwise, already have regulations for allowing research to enter clinical trials (albeit with varied levels of enforcement). However, most of these rules are non-specific and were created before stem cell treatments entered the limelight.

 

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Quadriplegic’s ‘lotto numbers come up’ in India

A paralysed Australian man hopes a controversial embryonic stem cell treatment he is undergoing in India will help him walk again. Quadriplegic Perry Cross credits the treatment – which is banned in Australia and most Western countries – with allowing him to breathe on his own for the first time in 14 years.

Within weeks of starting his treatment in March, Cross was also able to sit unaided for short periods of time. The Queenslander was paralysed when he broke his neck during a rugby union match in 1994, when he was 19. He plans to continue having the stem cell injections, and hopes that one day they will help him walk again.

“I’ve been in a stable condition ever since I left hospital in 1994 and I came here in March to receive treatment and in April I started to breathe,” he told Sky News in Britain. “So I put it down to the treatment. Nothing else has happened in the meantime that I know of. “I’ve received a bit of improvement in my arms already and my legs a little bit, so I’m hopeful when I come back, probably at the end of the year, I’ll hopefully receive more improvement.

“You know, you put your lottery numbers in every week and I feel by coming here, my lottery numbers have finally come up.”

Cross’ doctor Geeta Shroff has been criticised by some medical professionals who claim she has not published papers about her research or revealed how she uses the stem cells. But Dr Shroff, who has treated about 500 patients in India, defended her research, saying she had taken out a patent to protect her work and published it on the internet. For Cross, she injected stem cells derived from a “throwaway” embryo developed during an IVF cycle for a woman who had given her “full consent” to Dr Shroff’s research.

Dr Shroff said she was confident it was the stem cells that had begun repairing the damage to Cross’s spinal cord and allowed him to finally breathe on his own and sit unaided. “Today he is breathing within eight weeks of starting treatment,” she told Sky News. “No rehab can allow for a person to breathe on their own if their lungs are not working, if their spinal cord is not working.

“So if it has happened eight weeks after the stem cells (being injected), then obviously it is the human embryonic stem cells that is working.”

Dr Shroff said she hoped her technology would be made available around the world to patients suffering from incurable diseases and terminal conditions. “I believe this would change medicine, it is the beginning of a new era in medicine,” she said.

Since his accident in 1994, Cross has become one of the most sought-after motivational speakers in Australia. The Queenslander set up the Perry X Foundation three years ago to provide support for researchers trying to find a cure for paralysis. He has also advised the United Nations and worked with the late Superman star Christopher Reeve, who was paralysed after a horse riding accident, and became the actor’s stem cell ambassador in Australia.

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