A Conversation for The Processes of Death and Decomposition

Definition of death.

Post 1

Vestboy

On the radio yesterday (18/05/2004) they announced that work being carried out in the salt lakes round Utah ahd discovered bacteria which survive in the most inhospitalbe surroundings 30% saline solution and phenomenal levels of UVA radiation.

The programme then went on to talk about possible medical advances and the links with Mars. However one point which struck me as of relevance to this entry was they said that bacteria had been "revived" after being trapped inside rocks for 250 million years.

There are also examples of worms which are found in the desert which are totally dessicated and which if you pick them up and crumble them become a pile of dust. However should you add water they too revive. This is leading to advances in medicine where material which is organic and has to be kept at certain temperatures to retain its potency (e.g. insulin) could use something discovered from studying the worms to enable it to be dried and then "revitalised" by the addition of clean water for use without refrigeration.

Would the 250 million year old bacteria or the worms ever be classed as clinically dead?


Definition of death.

Post 2

saranoh - good girl gone Essex

The practice of freeze drying drugs for therapeutic use is already widespread in hospitals.
An example is Factor VIII concentrate given to people with Haemophilia A. Because the clotting factors have a relatively short half life and are so expensive to produce it makes more sense to reconstitute it when needed rather that keep it ready constituted when that would mean a much shorter 'shelf-life'.

It depends on your definition of 'alive'. Bacteria and such do not display the signs of life that enable us to class them as 'clinically' dead. After all, hair and fingernails continue to grow for some time after the person has been declared clinically dead, yet some cells are obviously continuing to function normally. So is that person clinically dead or not?


Definition of death.

Post 3

Vestboy

The interesting thing about these desert worms is that they are of sufficiently high development that they do display signs of life when they are "alive". To me it is like finding an earthworm that has been stranded on the pavement in the summer and has passed away and dried up. Sufficiently dried up that if you picked it up you could cruble it in your fingers. Then, with the addition of water it comes back to life and continues its journey.
I will try and find a link for further information.


Definition of death.

Post 4

saranoh - good girl gone Essex

Like that frog that lives in the African desert that crawls into a hole and 'dies' until the rains come along? Evolution is a truly fascinating thing.

I know that when conditions are such that they cannot survive, fungi are able to produce spores containing their genetic material that are able to withstand pretty much anything you can throw at them. Maybe the bacteria have adapted to do the same? I'm no microbiolgist really, but it's a theory.


Definition of death.

Post 5

Orcus

Bacteria spore under certain conditions. From what I've heard they can survive conditions in deep space like this.
Not sure if they'd survive a supernova mind you smiley - winkeye
We are whimps in the survival stakes.


Definition of death.

Post 6

Vestboy

We certainly are! We've only been around for 5 minutes (in the great scheme of things) and assume that we're eternal, when, as you say, we are extremely vulnerable.

Prions, I think, is the term for the invulnerable spores. CJD (human mad cow disease... thingy) prions cannot be removed from metal or plastic and are impervious to heat and most other methods of sterilisation. That has caused the recent crisis in the health service over disposable tools.

They now have an enzyme which, in the laboratory, can destroy (eat, dissolve or whatever) the CJD prions and it is hoped that this will be added to cleaning solutions that can be used in clinics and hospitals to eliminate cross infection.


Definition of death.

Post 7

saranoh - good girl gone Essex

Prions are in fact proteins which *act* in a viral manner, but of themselves are not infectious. They cause nvCJD by acting on the brain cells in a cascade like manner, i.e they change the chemical makeup of one brain cell, which in turn causes its neighbour to change and so on.. the end result is a brain which has turned to a jelly-like substance. Nice.

New enzyme thing? not in my lab we haven't. And I work in the blood transfusion department where we are perhaps more at risk than most. To be effective against prions it would have to be a proteolytic enzyme, which would be fine to use on surgical instruments but no good on lab benches as it would also digest the hands of the person cleaning the bench smiley - erm


Definition of death.

Post 8

Vestboy

I must have misunderstood the following article.
http://news.bbc.co.uk/1/hi/health/3112604.stm
If this link fails then you could search for cjd in the BBC website.


Definition of death.

Post 9

saranoh - good girl gone Essex

No, you had it right. They're probably going to use it on surgical instruments that are going to be reused, but it won't find it's way into general cleaning fluids like the ones we use to do the benches etc.


Definition of death.

Post 10

Vestboy

Ok. So your hands are safe then smiley - winkeye


Definition of death.

Post 11

saranoh - good girl gone Essex

oh yeah. This new stuff sounds far to expensive for the NHS to waste it on us lab rats. Vaguely remember signing something when I started stating that if I picked up an infection like Hep B or something through work, it's all my own fault. They generously immunize us against Hep B for free and we consider ourselves lucky smiley - biggrin.


Definition of death.

Post 12

Vestboy

Does anyone ever get MRSA?


Definition of death.

Post 13

saranoh - good girl gone Essex

No, but then I only come into contact with people's blood and occasionally yucky stuff like pleural fluid and it's not really transmissible that way.
A microbiologist will no doubt tell an entirely different story. We just don't get to hear about it.


Definition of death.

Post 14

Vestboy

They are good like that, aren't they?
Sadly, a friend of mine got Hep C through a blood transfusion. He's not doing too badly.


Definition of death.

Post 15

saranoh - good girl gone Essex

What comes of working for an organisation in which there are now more middle managers than beds, I suppose.

Hmm, that's not supposed to happen now, cos they screen for that and other stuff (including interestingly, syphillis. It's still required by law to do so) at the transfusion centre. Plus they are more selective about who they let donate blood.


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