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The real issue behind egg fusion techniques

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  • Ian Pitchford
    Welcome to BioNews, the free weekly news digest of the top stories in assisted reproduction and human genetics. Sent to subscribers each Monday, BioNews
    Message 1 of 1 , May 3, 2000
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      Welcome to BioNews, the free weekly news digest of the top stories in
      assisted reproduction and human genetics. Sent to subscribers each Monday,
      BioNews provides summaries of the week's news, commentary on the leading
      story and recommendations on books, exhibitions and other events.
      Please forward this mail to your friends and colleagues to encourage them
      to subscribe to BioNews.

      B i o N e w s 056

      Week 25/4/2000 - 1/5/2000

      ____
      C O N T E N T S:

      1 C O M M E N T A R Y
      * The real issue behind egg fusion techniques

      2 N E W S D I G E S T
      * Gene therapy success
      * New egg fusion technique
      * Cloned cows young for their age
      * Human genetic diversity project at risk
      * New study of multiple births families

      3 R E C O M M E N D S
      * Television, conferences and further reading

      ____
      1 C O M M E N T A R Y

      * THE REAL ISSUE BEHIND EGG FUSION TECHNIQUES:

      A new reproductive technology is on the horizon. Egg fusion, described in
      this week's BioNews, could have a significant impact on the lives of many
      women who cannot currently conceive naturally. Apart from the women with
      fertility problems who might benefit from this technique, egg fusion could
      also be of use to women who are at risk of passing on a mitochondrial disease
      to their children.
      But, rather than celebrating the fact that these people might soon be
      able to use a technology that would allow them to have a genetically related
      child, the British press got all excited about egg fusion for an altogether
      different reason. They worked out that the procedure isn't all that different
      from cloning.
      The similarity of egg fusion to reproductive cloning may be an issue
      worth mentioning, but there is another, much more immediate issue that was
      barely mentioned in the media commentary. It is that the French, Spanish and
      Italian researchers who worked on the egg fusion technique are prohibited
      from testing it any further because of restrictions in the laws of those
      countries. This means that a potentially viable reproductive technology will
      be slow to come to clinical practice and a whole host of infertile women or
      women at risk of passing on a mitochondrial disease to their children will
      miss out.
      In Britain, the creation of embryos for research purposes is not
      prohibited by law, but we don't have a proud tradition of charging ahead with
      new techniques. ICSI, egg freezing, ICSI using immature sperm and now
      probably egg fusion: these are all techniques that the HFEA has been
      reluctant to license in the UK. Yet, research that involves the fertilisation
      of human eggs in the laboratory (and thus the creation of a human embryo) is
      vitally important.
      There are three options available when it comes to developing a new
      technology that intervenes before or during fertilisation. The first is to
      not do the research and not make the technique available to anyone. The
      second is to forego embryo research and introduce the technique directly into
      clinical practice. And the third is to carry out research, making sure that
      fertilisation and subsequent development is normal and then introducing the
      technique into clinical practice.
      Which would you prefer? A technique which is tested on embryos, a
      technique which is tested on women or no technique at all?
      - Juliet Tizzard, director, Progress Educational Trust

      ____
      2 N E W S D I G E S T

      * GENE THERAPY SUCCESS:

      A team of French scientists at the Necker Hospital, Paris, has successfully
      used gene therapy to treat two babies born with a life-threatening genetic
      condition that affects the immune system. Usually, babies with severe
      combined immune deficiency (SCID) X1 have to live in sterile 'bubbles' to
      avoid any infections. But following the treatment, the babies are now living
      normal lives at home, the researchers reported in last week's issue of
      Science. A third baby is making similar progress after four months of the
      treatment.
      Children with SCID X1 have no working version of a gene that controls the
      development of the immune system. To carry out the gene therapy treatment,
      the researchers first harvested bone marrow from the patients. They then
      isolated blood stem cells from the bone marrow, which they infected with a
      virus carrying a replacement gene. After three days of repeated gene
      transfers, the cells were transplanted back into the patients, with no prior
      drug treatment. 'It was important to show success in the absence of any
      chemotherapy' said Dr Alain Fischer, co-author of the study.
      After just fifteen days, the scientists were able to detect new immune
      cells carrying the replacement gene in the patients' blood. The two baby
      boys, aged eight and eleven months, now have near-normal immune cell levels
      and have responded normally to routine polio, diphtheria and tetanus
      vaccinations.
      Fischer believes the key to their success lies 'not in the technique, but
      in the disease itself'. Immune cells with the replacement gene seem to
      multiply rapidly, overwhelming cells without a working gene. 'This means that
      even a poorly efficient gene therapy treatment - one that only introduces a
      few cells with the right gene - may work as a treatment' he said.
      - The Daily Telegraph 28/4/2000 'Gene trial frees babies from sterile
      bubbles'
      - The Daily Telegraph:
      http://www.telegraph.co.uk:80/et?ac=001190634958640&rtmo=kNY1bNep&atmo=rrrrrrrq&pg=/et/00/4/28/wgene28.html
      - BBC News Online 27/4/2000 'Gene therapy frees 'bubble babies''
      - BBC News Online:
      http://news2.thls.bbc.co.uk/hi/english/sci/tech/newsid%5F728000/728512.stm
      - ScienceDaily Magazine 1/5/2000 'Gene therapy frees two children from
      sterile bubbles'
      - ScienceDaily Magazine:
      http://www.sciencedaily.com/releases/2000/05/000501081423.htm
      - The Guardian 28/4/2000 'Immune cells gene therapy saves babies'

      * NEW EGG FUSION TECHNIQUE:

      A team of French, Spanish and Italian researchers has developed a new
      technique that may allow some infertile women to have their own genetic
      child. The new method, reported by the scientists in this month's issue of
      Human Reproduction, involves replacing the genetic information of a donor egg
      with that of the patient's egg.
      The technique could help those women whose embryos repeatedly fail to
      develop because of problems with the egg cell cytoplasm, which surrounds the
      nucleus. Although this problem affects less than ten per cent of women
      attending fertility clinics, they can currently only be treated using donated
      eggs. But by transferring the nucleus of one of her eggs to a donor egg with
      its nucleus removed, such a woman may be able to have a child who is almost
      entirely genetically her own (with the exception of the 37 genes present in
      the cytoplasm).
      The team has successfully managed to transfer egg nuclei to donor eggs
      using two approaches. One method involves using a chemical 'glue' called
      phytohaemagglutin, and the other involves a delicate microscopic manipulation
      similar to that used for intracytoplasmic sperm injection (ICSI). 'Because
      ICSI will probably be the best way of fertilising the reconstructed eggs the
      mechanical method we've developed will have the advantage of simultaneously
      fusing the eggs and introducing the sperm in a single, relatively simple
      action' said Dr Jan Tesarik, head of the team.
      So far, the scientists have not attempted to fertilise any of the
      reconstructed eggs, because the formation of embryos for research purposes is
      banned in France and Spain and strictly regulated in Italy. But Dr Tesarik
      believes they are now ready to try and develop treatment for women who might
      benefit from the technique.
      A spokesman for the UK's Human Fertilisation and Embryology Authority
      said that any UK clinic wishing to offer the technique could apply for a
      licence to create embryos using the method, but that doctors would have to
      satisfy the authority that the technique was safe before a licence could be
      granted. A spokesman for the fertility group Issue said the technique may
      assist thousands of couples to have their own baby.
      - The BBC News Online 26/4/2000 'Egg breakthrough hailed by scientists '
      - The BBC News Online:
      http://news2.thls.bbc.co.uk/hi/english/health/newsid%5F727000/727269.stm
      - The Guardian 27/4/2000 'New fertility treatment hope for childless'
      - The Daily Telegraph 27/4/2000 'Donor eggs to carry mother's own genes'
      - The Daily Mail 27/4/2000 ''Breakthrough' that gives IVF babies their
      mother's genes'

      * CLONED COWS YOUNG FOR THEIR AGE:

      Six cloned calves have cells that appear younger than their biological age, a
      US biotech firm reported in the current issue of Science. A team working at
      Advanced Cell Technologies (ACT) found that cells taken from the cows and
      grown in the laboratory have a lifespan increased by around 50 per cent.
      The results surprised the researchers, because the cows were cloned using
      cultured calf embryo cells that were nearing the end of their lifespan. 'The
      old cells were not merely returned to a youthful state. They were actually
      given a longer lifespan than those from normal animals' said Dr Robert Lanza,
      who carried out the research. The scientists also found that a gene (EPC-1)
      whose activity normally declines with age was five times more active than
      normal in the cloned cells.
      A cell can usually only multiply a certain number of times before it
      dies. Each time a cell divides, the ends of its chromosomes, called
      telomeres, become shorter. The telomeres of the cells from the cloned calves
      are longer than those of normal cows of the same age. When grown in the
      laboratory, cells from a normal newborn calf divide up to 60 times, but the
      cloned cells can divide up to 90 times.
      The team thinks its results may be down to the type of cell used to
      create the clones - a skin cell, or fibroblast. When Dolly the cloned sheep
      was born, her cells appeared to be the same age as the mammary cell of the
      six year-old ewe from which she was cloned. Another factor may be the stage
      in the life cycle of the donor cells. The cells used to create the calves
      were still growing and multiplying, whereas those used to clone Dolly were
      in a resting stage.
      Although a long cell-life may not mean the animals live longer than
      normal cows, the company says its work has important implications for human
      therapeutic cloning - the use of cloned early embryo cells to replace damaged
      or diseased body tissues. The ability to create a supply of youthful cloned
      cells may get around the potential problem of growing enough cells in the
      laboratory before they become too old to use for treating patients. 'It's the
      first day in a new era in treating age-related disease' claimed Dr Michael
      West, president of ACT.
      - The Daily Telegraph 28/4/2000 'Scientists turn back the clock'
      - The Daily Telegraph:
      http://www.telegraph.co.uk:80/et?ac=001190634958640&rtmo=V6gk86rK&atmo=rrrrrrrq&pg=/et/00/4/28/nage28.html
      - BBC News Online 27/4/2000 'Cloning cattle reverses ageing'
      - BBC News Online:
      http://news.bbc.co.uk/hi/english/sci/tech/newsid_728000/728088.stm
      - The Guardian 28/4/2000 'Cloned calves offer clues to 'fountain of youth'
      effect'
      - The Sunday Times 30/4/2000 'Cloned cells can mend human organs'
      - The Sunday Times:
      http://www.the-times.co.uk/news/pages/sti/2000/04/30/stinwenws02010.html

      * HUMAN GENETIC DIVERSITY PROJECT AT RISK:

      The Human Genome Diversity Project (HGDP), a scheme to collect and analyse
      DNA samples representing the world's ethnic diversity, is fighting for its
      life, according to a news report in last week's Nature.
      A combination of political and public controversy has turned the
      ambitious international project into a set of DNA collection projects, funded
      from a variety of sources. Without further support, the DNA database and
      repository originally planned by the project's organisers seem unlikely to go
      ahead.
      Some countries, such as New Guinea, are demanding a fee for every sample
      taken by researchers. Others, such as India, have completely forbidden the
      export of DNA. The HGDP may also have lost funding to projects with
      overlapping aims, such as the SNP (single nucleotide polymorphism)
      consortium, which aims to identify genetic differences associated with
      disease or drug responses.
      'Our lack of funding is a huge issue' says Henry Greely, a spokesman for
      the HGDP. But he added that rumours that the HGDP has died, or is in a
      comatose state, were exaggerated. Lap-Chee-Tsui, president of the Human
      Genome Organisation (HUGO), says that the programme doesn't have clearly
      defined goals and questions. But former HUGO president Walter Bodmer thinks
      that support for the HGDP project will grow, as more scientists become aware
      of the uses of data on genetic variation.
      - Nature 27/5/2000 'Genetic diversity project fights for its life'

      * NEW STUDY OF MULTIPLE BIRTHS FAMILIES:

      A new study of parents who have multiple births following fertility treatment
      has found that they are more at risk of physical and emotional problems than
      parents who have a single baby. The report, published in this month's issue
      of Human Fertility, looked at 54 families which had children following
      treatment using assisted reproduction techniques.
      The study found that mothers of twins and triplets may become socially
      isolated, because they find it difficult to get their babies ready to leave
      the house and too daunting to use public transport. But after years of
      longing for children, many feel too guilty and ashamed to admit they are
      having problems coping, says Dr Alexina McWhinnie, author of the study.
      Over the past 20 years, the incidence of twins has nearly doubled, and
      that of triplets nearly quadrupled. Last year, the Royal College of
      Obstetricians and Gynaecologists recommended that a maximum of two embryos be
      transferred into women receiving fertility treatment, to reduce the numbers
      of multiple births.
      'If more than two embryos are transferred then clinics should consider
      targeting those families most at risk in relation to social factors' said Dr
      McWhinnie. She added that these families should have adequate and immediate
      help once they leave hospital, and continuing support over a considerable
      period.
      - The Independent 1/5/2000 'Multiple births 'put great stress on couples''
      - The Independent:
      http://www.independent.co.uk/news/UK/This_Britain/2000-05/infertile010500.shtml

      ____
      3 R E C O M M E N D S

      * TELEVISION, CONFERENCES AND FURTHER READING:

      'The Fifth World Congress of Bioethics' / Imperial College, London, UK /
      21-24 September 2000
      Organised by the International Association of Bioethics, this four day
      conference will focus on the relevance of bioethics and healthcare ethics to
      professional practice, policy and law. Costs £250 for IAB members and £270
      for non-members. For further details and on-line registration visit the
      website at
      http://www.uclan.ac.uk/facs/ethics/fifthcom.htm

      'Defining Features: Scientific and Medical Portraits / The National Portrait
      Gallery, London, UK
      An exhibition of portraits of scientific and medical men and women, including
      Marie Curie, Edward Jenner and John Hunter. Free, in the Studio Gallery until
      17 September.

      'Genetic testing and insurance' / The Lancet / 29 April 2000
      A feature article outlines the view that fears about genetic discrimination
      by insurers may be unfounded, and that legislation in some countries brought
      in to register social disapproval may have caused patients and geneticists
      unnecessary concern.



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      B i o N e w s
      Copyright Progress Educational Trust 2000

      For editorial enquiries, please contact:

      Dr Jess Buxton
      Editor, BioNews
      Progress Educational Trust
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      Full editorial control rests with Progress Educational Trust

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