Adamantane resistance in flu explained

Nick Anthis has a very nice (and very readable!) overview of why flu viruses (including the new A/H1N1 strain) are resistant to adamantane, one of the antiviral drugs that can be used to treat influenza infections.

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It is amazing how quickly simple organisms can evolve and develop resistance to controlling agents. This is why bacteria make such great test subjects for science fair projects.

I was confused by the name of the drug so I looked it up on Dictionary.com. Here is a report of what I found:

adamantane -â noun Chemistry. A white crystalline alicyclic hydrocarbon, C10H16, consisting of four fused cyclohexane rings, with the carbon atoms arranged as in the diamond lattice. Origin: see adamant, -ane; so called from the diamondlike arrangement of the carbon atoms.

amantadine -â noun Pharmacology. A water-soluble crystalline substance, C10H17NHCl, used as an antiviral and antiparkinsonian drug.

Origin: 1960â65; coinage appar. based on the chemical name 1-aminoadamantane; see amino-, adamantane

adamant
-â adjective
1. utterly unyielding in attitude or opinion in spite of all appeals, urgings, etc.
2. too hard to cut, break, or pierce.
â- noun
3. any impenetrably or unyieldingly hard substance.
4. a legendary stone of impenetrable hardness, formerly sometimes identified with the diamond.

Origin: from Latin adamantem, from Greek adamas "unbreakable," the name of a hypothetical hardest material, from a- "not" + daman "to conquer, to tame". Applied in antiquity to white sapphire, magnet, steel, emery stone, and especially diamond. Sense of "unyielding" first recorded in 1677.

adamantine -â adjective. Utterly unyielding or firm in attitude or opinion.

adamantean -- Of adamant; hard as adamant. --Milton

Yeah, I was kind of hoping this post was about the Wolverine movie. Interesting nonetheless ;)

Can SWFL mugginess block the bug?

http://www.nbc-2.com/articles/readarticle.asp?articleid=29018&z=3

The results showed that a low relative humidity from 25-35 percent resulted in the highest infection rate amongst the healthy guinea pigs. The transmission rate at that lowest humidity level was from 75 to near 100 percent!

At somewhat higher relative humidity - 50 percent - the infection rate dropped to only 25 percent. If that change wasn't startling enough, when the researchers raised the relative humidity to 80 percent, none of the healthy guinea pigs got sick!

By Vulariter (not verified) on 01 May 2009 #permalink

Tara,
I'd be interested to learn more about flu testing techniques. It seems like the labs are having a hard time processing the incoming samples. My layman's expectation would be that they would have the ability to test perhaps 10,000 samples a day without any difficulty. It appears that CDC capacity is a tiny fraction of this amount! What is this test like? Why is their throughput so low?

http://www.calgaryherald.com/Health/antibody+method+gets+test/1557875/s…

Trial by fire: New antibody method gets big test

When the blood samples arrive, the teams will isolate a type of immune system cell known as antibody-secreting plasma cells, which produce a surge of antibodies as part of an initial response to infection.

Using these cells, the researchers will go to work making highly targeted antibodies against the new flu strain.

By vulariter (not verified) on 02 May 2009 #permalink

Don't walk. RUN to your nearest hospital emergency room the moment you or your child sneezes or sniffles!

Not a peep from Tara for an entire month, then all of a sudden, out of the blue, seventeen, yes count them, 17, rapid fire semi-hysteric posts about the global threat of pandemic sneezing and sniffling from common yearly colds and flu.

Thanks Tara. Thanks CDC. Thanks global healthcare paranoiacs and drug manufacturers and thanks to all those legions of mass paranoid delusionals who scare themselves sick, and the legions more who tremble at the thought of their own or their family members imminent deaths, and thanks to all the media whackaloons who are doing their best to secure their jobs by pandering to paranoia.

Your combined annual outbreak of paranoid delusional drama is not to be missed!

Sniffle. Uh Oh. Sniffle sniffle. Maybe I was wrong.

uhhaahhh. Uhhaaaagghhhhh.....Oh no! I feel a sneeze coming on and both my hands are too busy griping at you guys to even cover my mouth. uhhhaaagghhhhh. Duck and cover. Run for the hills. The sky is falling. I'm gonna sneeze. I'm gonna die. We are all gonna get pandemic flu. We are all gonna die!

By AaaahhhHHCHOOOooo!!! (not verified) on 02 May 2009 #permalink

Tara,

Is this true?

"Fortunately, survival is the prime instinct of a virus, so if its human hosts begin to die too quickly or in such great numbers, the virus will end up causing its own extinction. This is why epidemics and pandemics on their own reach their natural end. Our shared survival is our common goal."

source: http://opinion.inquirer.net/inquireropinion/columns/view/20090502-20274…

By vulariter (not verified) on 02 May 2009 #permalink

ah, nice to see that some of the germ theory denialists still stop by to check out my blog.

vulariter, that's true--kind of. Of course viruses have no "survival instinct," but if an organism depends on person-to-person transmission in order to be maintained in a population, and has a relatively short incubation/infectivity period (as influenza does), there will be something of a trade-off between transmissibility and virulence. Too virulent = organism will die out in the population, because there won't be enough ambulatory people around to spread it (and therefore the transmission of the organism will cease). There are exceptions, however--organisms that have a long infectious period (such as HIV) or don't need direct H2H transmission (such as malaria) can cause high mortality rates in humans and still spread just fine. It's a fascinating area, and more than I can answer in just one response--but Paul Ewald's "Evolution of Infectious Disease" is a good starter for more info if you're interested.

Thanks, Tara.

Here's some interesting stuff:

http://www.thenews.com.pk/daily_detail.asp?id=175577

What scientists know about swine flu

âThere are two aspects - one is which receptors the virus tends to bind to and what we see is that it is binding to the upper respiratory tract rather than deep in the lungs.â When a flu virus binds to the upper respiratory tract, it tends to cause mild illness but can be easily spread as people cough and sneeze, Professor Barclay explains."

"That is there seems to be nothing unusual as yet in another protein in the centre of the virus, called NS1, which is linked to the strength of the immune response the virus produces.

In some more pathogenic viruses, it is this NS1 protein which initiates a âcytokine stormâ, a particularly severe immune reaction that can be fatal in even healthy young people."

By vulariter (not verified) on 02 May 2009 #permalink

http://www.cdc.gov/ncidod/Eid/vol12no01/pdfs/05-1132.pdf

The Swine Flu Episode and the Fog of Epidemics

by Richard Krause

"I relate these personal reminiscences because many who read this article will be on the firing line when future epidemics threaten, and they may either erupt or fizzle out. You will be in a fog, and you will need to exercise the best judgment you can on the basis of available surveillance information and historical context. "

By vulariter (not verified) on 02 May 2009 #permalink

But when my son showed delays---his gross motor development was definitely behind---the first thing I thought of was relatives with similar delays in walking.

I feel the fears of parents and yes, we did get my son's medical records from when he was an infant and toddler to find out as much as we could about what vaccines he'd been given.

But I think the vaccine discussion needs to broaden out to take genetics much more fully into consideration (beyond talking about "genetic predispositions") and to think that there can be _causes_ of autism.

Thanks very much for your front-line perspective; I at least really need to hear it

Hey Tara! Are you back to spreading your BS about HIV and its fairy tale nonsense of causing aids via CD4 T-cell loss?

Absolutely NOWHERE is CD4 loss verified to be due to HIV. Every HIV researcher admits that no mechanism by which hiv affects CD4 T-cells has ever been found. NOWHERE, that is, except in the imaginations of Tara and her overpaid retroviral cohorts who all are cashing in on the unproven HIV theory.

WHAT IS COMPLETELY WELL PROVEN TO CAUSE CD4 LOSS IS INTENSE STRESS!

http://www.ncbi.nlm.nih.gov/pubmed/15710460

Like drug abuse, and extreme emotional anxiety (such as the extreme anxiety caused by the diagnosis itself), and overexertion such as while strung out on dope like crystal meth!

Hey Bright Girl! CD4 cells come from the thymus gland. Stress is WELL VERIFIED TO CAUSE THYMUS MALFUNCTION

The aim of this study was to investigate whether chronic stress, induced by repeated daily swimming during 21 days, alters the morphofunctional parameters in the thymus of adult rats. Our results showed that chronic stress reduced thymus mass, total number of thymocytes, volume of the thymus compartments and numerical density of thymocytes within thymus inner cortex and medulla. However, the percentage of apoptotic cells and the level of corticosterone were significantly increased. The percentages of CD4-CD8-TCRalphabeta(low/high) and CD4-CD8+TCRalphabeta(-)thymocy tes were significantly increased, while the percentage of the least mature CD4+CD8-SP TCRalphabeta(-) thymocytes was significantly decreased. These results show that recurred swimming procedure induces thymus hypotrophy and elevated percentage of DN TCRalphabeta(+) cells.

By Deny This! (not verified) on 02 May 2009 #permalink

Well, whatya know! Forced swimming or even overexercising of hiv positives could cause them to be diagnosed with aids by gettin a low CD4 count from chronic stress and such!

Dang, Them thar hiv posertives better be golly be careful of overexertions! They'll surely get diagnosed as aids just causa duh low t cells!

Whoda ever thunkit? Stress causes CD4 depletion via suppressions of the thymus gland! Wowsers!

By Wilbur Hushkins (not verified) on 02 May 2009 #permalink

Tara, would you please shut these aids denialist clucks up once and for all by telling them and all the world exactly how hiv kills t-cells. Point out the exact studies. Pleeeeeease. You're an aetiologist. If you can't do it then nobody can.

(There is proof somewhere that hiv kills t-cells, isn't there?)

By Had enough! (not verified) on 02 May 2009 #permalink

The antiviral agents are not adamantane itself, but two amino derivatives of adamantane called amantadine and rimantadine. These compounds have been used in the past against the type A influenzas. I believe, however that resistance has developed to these compounds thank you man