Melatonin has a very short half life and is secreted as needed by the pineal gland. It's apparent primary biological function is as a signal transduction/regulatory molecule. It's unclear if this function is what is responsible for its protective effect in ischemia-reperfusion injury (IRI), because melatonin is also a powerful radical scavenger - and in fact, a particularly effective scavenger of the radical species associated with neuronal injury in IRI, such as peroxynitrite. Other factors to consider are the timing, route of administration and dose used in our studies. The drug was given intravenously in a micellized form to speed delivery across the blood brain barrier. This was done at the start of reperfusion. Finally, the effective dose given was very large (and was based on the stoichiometry of the radical species we wanted to scavenge). The drug was also given in conjunction with many others and, perhaps critically, in combination with the rapid induction of mild therapeutic hypothermia ( 3 deg C below normothermia). Next up on my agenda to test was whether the drug combination was effective without hypothermia since it is very problematic to achieve a 3 deg C reduction in body temperature in ~15 min or less! Unfortunately, that study was canned.
The point here is that the application of any such treatment in the setting of a critical illness would require that it be both an integrated and ACCEPTED part of the medical infrastructure. For instance, it was over 30 years ago that Peter Safar, et al., demonstrated that mild hypothermia AFTER cardiac arrest was profoundly effective in reducing ischemic brain injury, and it has been 9 years since ILCOR made post-cardiac arrest hypothermia the standard of care: http://circ.ahajournals.org/content/108/1/118.full. And yet, post-arrest hypothermia is used almost nowhere. So, even if a treatment is approved and demonstrated to be scientifically valid, it still may not see widespread clinical application for a host of reasons.
I recently watched a BBC documentary called "Back From The Dead", mainly about using extreme hypothermia to prevent IRI in some rather extreme cases, though drug development was also mentioned (that portion mostly focused on the study of cell death).
One case was a Norwegian woman who fell in a crevasse while hiking on a glacier - the extreme cold plus 3+ hours of constant CPR was enough to keep her brain alive long enough to be revived. She made a full recovery and now works at the hospital that revived her.
Another was a man who's blood was inte...
In the February and March 1988 issues of Cryonics, Mike Darwin (Wikipedia/LessWrong) and Steve Harris published a two-part article “The Future of Medicine” attempting to forecast the medical state of the art for 2008. Darwin has republished it on the New_Cryonet email list.
Darwin is a pretty savvy forecaster (who you will remember correctly predicting in 1981 in “The High Cost of Cryonics”/part 2 ALCOR’s recent troubles with grandfathering), so given my standing interests in tracking predictions, I read it with great interest; but they still blew most of them, and not the ones we would prefer them to’ve.
The full essay is ~10k words, so I will excerpt roughly half of it below; feel free to skip to the reactions section and other links.
1 The Future of Medicine
1.1 Part 1
1.1.1 Diagnostics
A side-note: genetic associations have been a very fertile field for John Ioannidis, and a big study just blew away a bunch of SNP-IQ correlations.
I recently learned that, besides the usual blame for increasing medical costs, some categories of doctors have been strenuously urged to reduce MRI use as actively harmful.
1.1.2 Resuscitation
1.1.3 Antibiotics
The pharmaceutical industry and antibiotics have been a case-study in stagnation, failure, and diminishing marginal returns. There is only one, highly experimental, anti-viral that I have heard of. In a followup email, Darwin responded to someone else pointing out DRACO:
(This agrees with my own general impressions, which I didn't feel competent to baldly state.)
1.1.4 Immunology and cancer
1.1.5 Atherosclerosis
1.2 Part 2
1.2.1 Anesthesia
1.2.2 Surgery
1.2.3 Geriatrics
We all know how well this has worked out. More troubling is that in some respects, we appear further from any solutions or treatments than before; while resveratrol did well in a recent human trial, the sirtuin research that seemed so promising has been battered by null results and failures to replicate. And anti-aging drugs have their own methodological difficulties; from the followup email:
1.2.4 Psychiatry & Behavior
From the previously quoted followup email:
1.2.5 Implants & Prosthetics
1.2.6 Hemodialysis
1.2.7 Organ Preservation
1.2.8 Other Approaches to Organ Preservation
1.2.9 Genetic therapy
1.2.10 Prevention
1.2.11 The Downside
And on to the economics:
2 Reactions
On reading all the foregoing, I commented: that was a depressing read. As far as I can tell, they were dead on about the dismal economics, somewhat right about the diagnostics, and fairly wrong about everything else. Which is better than the old predictions listed, only one of which struck me as obviously right (but in a useless way, who actually uses perfluorocarbons for liquid breathing?).
To which Darwin said:
See also Fight Aging!’s post, “Overestimating the Near Future”:
Darwin comments there:
3 Further reading
Previous Darwin-related posts:
See also Tyler Cowen's The Great Stagnation and “Peter Thiel warns of upcoming (and current) stagnation”.