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Things we know in January 2008 that we didn't know in January 2005

If your heart stops beating for five or more minutes, you're dead. Right? Wrong! (Newsweek report.) Oxygen-deprived cells in cardiac muscle don't die after five minutes, or even an hour. But if they're deprived of oxygen for more than about five minutes, then when reperfusion begins, the presence of oxygen triggers apoptosis, a cell death mechanism (that usually defends us against cancer by causing cancer cells to self-destruct). More on reperfusion injury here (educated layperson level); if you really want to know more, start with the references on this page.

Is Alzheimers a type of diabetes? Insulin isn't just a hormone that modulates cellular uptake of glucose and uptake and conversion of blood lipids into cell-bound triglycerides — it's found in the brain, where it serves to stimulate choline acetyltransferase, a key enzyme in the synthesis of acetylcholine, a neurotransmitter without which you're stuffed. And levels of insulin in the brains of Alzheimer's patients drop in step with the degree of dementia. There's nothing conclusive here yet, but if this is the root cause of Alzheimer's, then it suggests where researchers ought to be looking for new treatments.

(Anyone want to add anything to this list?)

14 Comments

1:

I think we knew about reperfusion injury long before 2005, I can remember giving a talk which brushed on aspects of it in 1997. (It was really about abdominal compartment syndrome, since you ask.)

And, yes, I'm a medic. So I'm *allowed* to be interested in this sick stuff. Honest, Guv.

2:

Read just last night that we now know that not only can memories be retrieved temporarily by inducing small electric currents in the frontal lobes*, but that old memories can be retrieved and their later retrieval be made easier by use of current in the deep brain on only the first retrieval. Application to Alzheimer's and other dementia treatments left as an exercise for the reader.


* Mapping those effects was a side-effect of a lot of brain surgery in the second half of the 20th century.

3:

It is way too soon to say we know that Alzheimer's is a result of diabetes. The findings are interesting, even intriguing, but a long way from being confirmed.

One thing we know today that we did not know in 2005 is that the universe is expanding faster than expected, as if by a repulsive force, mechanism unknown.

4:

While we're on medical topics:

Not only does genetic predisposition to depression and anxiety exist, but some events may be innately "depressogenic" while others are "anxiogenic".

Talking about traumatic events immediately after they occur makes PTSD more likely, not less.

Induced hypothermia dramatically improves the odds that someone who has had a heart attack will live.

5:

The (certain to some extent but as yet under early investigation) links between AD and (type 2, mostly) diabetes are my current research topic. I'm not (cheers from audience) going to give you the multi-hour version of this, but:

* there's a huge controversy over insulin in at least the adult mammalian brain (best data come from e.g. fruit flies) _but_ as it turns out hippocampal insulin is required for decent cognitive performance

* we've known that insulin within the brain can modulate feeding for >30 years, but only recently has it been looked at outside the hypothalamus

* insulin interacts with beta-amyloid in several ways, including competing for degradation, direct modulation of signalling, and regulation of secretion and removal to the CSF. It looks very strongly as though the systemic hyperinsulinemia and insulin resistance seen in T2DM also occurs within the brain, leading to what appears to be AD and certainly cognitive/metabolic impairment and amyloid accumulation. Yes, this means that we should expect AD to be on a massively upward trajectory over the next 20-30 years. Work out!

[And I agree that we knew about reperfusion a long time back. It turns out that this is also linked to glucose - providing glucose during recovery makes things worse, not better, as excess neural activity leads to excitotoxicity - and so I also have an excuse for my geekery here...]

7:

And something that came up a few months ago, and fits with some stuff being tried in Germany, is that diabetics have problems with one of the B vitamins. Thiamine, if I recall right. The research hasn't been confirmed, but it seemed to be excreted more rapidly, and there are plausible connections with common side-effects of diabetes.

I suppose the German use of benfotiamine may be just another vitamin fad (I understand there are elements of cultural faddism in what doctors say when they have to pick a placebo), but I can't help thinking of Scott of the Antarctic. A century ago, some of the basics were only just getting past the empirical stage typified by the handling of scurvy.

8:

We know the spiders are on Mercury, not Mars:

http://tinyurl.com/ysqceq

Dead people's eyes can tell us when they were born:

http://tinyurl.com/2tmc28

And tigers can really leap a long way:

http://tinyurl.com/2uxjz6

9:

How about an article from just today, that I consider to be a very irresponsible if not just dangerous headline (consider the source): AIDS experts: Unprotected sex OK for some

http://www.msnbc.msn.com/id/22934058/

10:

To Rose Fox (4): Induced hypothermia is not only for heart attacks. Apparently it can help save movement after a spinal injury:

http://www.iht.com/articles/2007/09/12/sports/nfl.php

11:

Steve Thorn @9: eek, that's not good at all!

Someone is really out of touch with the real world if he thought it was reasonable to say that in public ...

12:

A Chinese drug manufacturer cross-contaminated some cancer drugs and paralyzed a few people. They are the sole manufacturer of RU-486 for the U.S. The FDA says it's ok, because the plants are an hour away from each other (and, apparently, a world apart). The FDA won't even say if the company exports other products to the US.

http://www.nytimes.com/pages/world/asia/index.html

(Registration required, and I am technologically impaired and cannot make a hyperlink, sorry.)

If you think the US FDA doesn't care if US consumers and patients live or die, you have probably been paying attention.

13:

That link is:

http://www.nytimes.com/2008/01/31/world/asia/31pharma.html?_r=1&ref=asia&oref=slogin

It's 200 Chinese patients so far, who have leukemia, and the company is state-owned. The plant had stored multiple cancer meds in the same fridge and one of them contaminated the other two -- that one being too toxic for spinal injections. The FDA said:

The United States Food and Drug Administration declined to answer questions about Shanghai Hualian, because of security concerns stemming from the sometimes violent opposition to abortion. But in a statement, the agency said the RU-486 plant had passed an F.D.A. inspection in May. “F.D.A. is not aware of any evidence to suggest the issue that occurred at the leukemia drug facility is linked in any way with the facility that manufactures the mifepristone,��? the statement said.

Pfizer had refused to use meds from this company because they didn't meet their standards.

Also from the article:

Mr. Zheng at Peking University said that producing multiple drugs in a single workshop was risky, but that some Chinese companies saw it as a way to save money. “It was an accident,��? he said of the Hualian case. “But it was bound to happen.��?

If you want to sign on to sites that require registration and you don't want to register, use http://www.bugmenot.com/. I usually just register and call them bad names in the password.

14:

Dave Bell,

Benfotiamine / benfothiamine as a medical treatment for diabetic neuropathy is about as corroborated a treatment as any have been.

If you have diabetes, or know anyone who has it, search up on it on medline. (And please do so before reading about it on the raw net. Some web pages write about it with the hype given to pollen or [supplement flavor of the week])

Over the past 15 years multiple studies found that it worked, and then about 4 years ago studies found how it worked. The two sets together make a convincing case.

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This page contains a single entry by Charlie Stross published on January 31, 2008 1:31 PM.

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