BBC Street Science 1: Human-animal embryos

This past week BBC Radio 4 did a daily show called Street Science. Each was a short (approximately 15 minutes) programme wherein a leading UK scientist would have a discussion on a controversial area of science with members of the public. That public would be specifically chosen to be a group that would likely have an opinion at the other end of the controversy.

The first programme had the unfortunately-named Professor Stephen Minger, an expert in stem cell research, explaining what he does to some members of St. Mary’s Anglican Church in Kent. It’s a very calm, straightforward discussion, with very little controversy at all. Stem cell research is a good thing, and very strictly regulated here.

I think the lack of controversy is a symptom of a meeting of reasonable minds, one-on-one, rather than of sensationalist reporting through headlines and non-experts.

Playback is only in RealAudio, but it’s worth a listen. I’ll be blogging about the rest of the series throughout the next five days.

Engineering a new trachea

Stem cell research has translated into a real and exciting practical medical application. From ScienceDaily:

The first tissue-engineered trachea (windpipe), utilising the patient’s own stem cells, has been successfully transplanted into a young woman with a failing airway. The bioengineered trachea immediately provided the patient with a normally functioning airway, thereby saving her life.

A seven-centimetre tracheal segment was donated by a 51-year-old transplant donor who had who had died of cerebral haemorrhage…Using a new technique developed in Padua University, the trachea was decellularised over a six-week period so that no donor cells remained.

Stem cells were obtained from the recipient’s own bone marrow, grown into a large population in Professor Martin Birchall’s lab at the University of Bristol, and matured into cartilage cells (chondrocytes)…The donor trachea was then seeded with chondrocytes on the outside…allowing them to migrate into the tissue.

Four days after seeding, the graft was used to replace the patient’s left main bronchus. The operation was performed in June 2008 at the Hospital Clinic, Barcelona, by Professor Paolo Macchiarini of the University of Barcelona.

Embryo research in the UK

Continuing the genetic theme from my last post (but dropping the mouse theme from the last two), I note that we’re smack dab in the middle of Parliamentary decisions on matters of embryology and stem-cell research.

Yesterday MPs debated changes in the proposed Human Fertilisation and Embryology Bill, which would update laws last set in 1990. Two related challenges before the house were voted on:

  1. To ban hybrid human-animal embryos
  2. To ban so-called “saviour siblings”

Both challenges were defeated in a free vote, and so both practices upheld, by margins of 336-176 and 342-163 respectively. This is a good result, and I’m glad that science and reason and – yes – ethics won over sensationalism and superstition.

Human-animal hybrid embryos are the best means for us to do stem cell research that might be used to treat diseases like Alzheimer’s. Stem cells have been produced from other sources, but they’re not as adaptable as embryonic ones. Some people have reacted viscerally to the idea of the “Frankenstein” production of a hybrid. The reality is that there are far too few human eggs donated to do the research. Tests have shown that using animal eggs, removing almost all the genetic material, and then inserting a human cell nucleus into the shell produces stem cells that are as useful as purely human ones. And the proposed changes to the legislation mean that all such testing would have to be pre-approved by government bodies, that no such hybrid embryo would be allowed to be implanted in a human, and that all such embryos would have to be destroyed 14 days after they were created.

“Saviour siblings” refers to a parent with a child who has a disease or disorder that can only be treated by material from a close genetic match using IVF to create embryos, testing them to see if one provides the life-saving match, and then letting that one develop while the other embryos are discarded. People have done this in the past already by simply having more babies; they just didn’t have the means to detect the compatibility at the embryonic stage. Discarding unwanted embryos has always been a part of IVF treatment in any case, since the procedure almost always produces several.

The Roman Catholic Church and other religious groups supported these challenges, of course, as they believe that life begins at conception. They don’t like it, but the law in the UK says that embryos are not persons. So long as abortion is legal here it would be hard to outlaw these new practices. But I believe there are strong ethical cases to be made for these practices on their own merits: there is a good chance that they could save many lives in the future. Stem cell research , especially, holds a lot of promise and needs to be explored.

Abortion itself is one of the next topics under debate. As I write this, MPs are considering whether to reduce the upper time limit on abortions from 24 weeks down to 20 weeks. To be completely honest I don’t have too much opinion on this one: I don’t know the science well enough and only about 1.5% of abortions in England and Wales happen after 20 weeks anyway.

In addition, today they’ll look at removing a current requirement for IVF clinics to consider “the need of that child for a father” before offering treatment. If that goes, it’ll make it easier for lesbian couples to receive IVF treatment and have children. I honestly believe it’s very important for children to have male and female role models. But while it’s clear that a departed father can have a negative effect on a child there’s no evidence that there’s any detrimental effect if there never was a father to begin with. And having a father is certainly no guarantee of love and support. Ultimately, I don’t think it’s right to dictate what structure is right for any particular family, so I support removing the requirement. I’ve read that this is what IVF agencies have effectively been doing in recent years anyway, since recent Human Rights rulings support children for same-sex couples.