hearts and minds

My latest feature in Current Biology juxtaposes a highly acclaimed project to simulate the function of the heart and a somewhat controversial, but well-funded one to do the same for the brain.

Simulating hearts and minds

Current Biology, Volume 23, Issue 5, R177-R180, 4 March 2013

doi:10.1016/j.cub.2013.02.032

Free access to the full text in HTML and in PDF format.

Here is a video about the Alya Red project featured in my article:

Alya Red: A Computational heart

This video recently won Science magazine's prize for science communication.

vampires rejoice

... at the prospect of unlimited supplies of human blood from the tap at their local:

British scientists to create 'synthetic' blood

But seriously, this was about time, as people are dying when blood reserves are running out, or getting too old, or lacking nitric oxide, or have been infected with some pathogen that nobody expected. This endeavour is a brilliant example of how cells from a single "leftover" embryo from IVF -- remember this is a clump of identical cells, which has never been inside a human being, and which would otherwise be thrown away -- can save hundreds of lives. According to the report in the Independent, cited above, we're three years away from clinical trials.

blood transfusion risks

Many blood transfusions may increase risks, doctors warn, the Guardian reports, apparently based on a story in New Scientist. Well, I agree completely, but then the piece goes on rambling about how boffins don't understand why blood that has been stored is often doing more harm than good.

In fact, last October, two independent and very convincing papers (one was actually commissioned to check the findings of the other, because of the enormous importance of the issue!) showed that there is a very simple reason, and a very simple way to fix the problem.

Fresh blood contains nitric oxide (NO) bound to hemoglobin, which it loses within hours of storage. NO is needed as a signal to widen the blood vessels. So old blood without NO will lack the vessel-dilating effect and thus the oxygen provision may be no better than or even worse than what the patients could achieve with their own blood. The problem is easy to fix, as NO can be added to the stored blood before transfusion, making it good as new.

I reported all that in Chemistry World and in this blog entry, back in October. Naively, I would have hoped that by now medics would have made moves to implement the fix, rather than scratching their heads over a question that has already been answered.

fresh blood

Researchers have found that over-generous blood transfusions can do more harm than good. Ironically, the measure which is supposed to improve oxygen provision to the patient's organs, can have the opposite effect.

Now there is an explanation to this paradox. It appears that the oxygen transport depends on a signalling process by which the red blood cells help to widen the blood vessels, and this involves nitric oxide bound to hemoglobin. Donor blood for transfusion can be legally stored for 42 days, but the nitric oxide disappears within the first few hours of storage, so virtually all stored blood samples are deficient in that respect.

While this sounds quite scary, there is a silver lining in that the NO content can be restored.

Read my story here:

Blood transfusion risk explained