X-Message-Number: 4952
From:  (James Band)
Newsgroups: sci.cryonics
Subject: New formula for Freezing
Date: Mon, 9 Oct 1995 13:26:32 GMT
Message-ID: <>

All,

I came across the following article in the Sunday Times (South African) 
recently & thought it may be of interest to the cryonics people.

"Until now, donor hearts had to be transplanted within four hours or the 
tissues degenerated, rendering the organs unusable. But a new formula hs the 
potential to extend the life of donor hearts indefinitely. Hearts are 
saturated in the cryo-preservant formula before being frozen in liquid 
nitrogen. The formula has been developed by Olga Visser, a cardio-vascular 
perfusionist at Pretoria's H F Verwoerd hospital, working under the guidance 
of its head of cardio-thoracic surgery, Prof Dirk du Plessis, biomedical 
engineer Professor Pierre Cilliers, and physiology professor Chris Steinman. 
While much testing lies ahead, indications are that the formula will allow 
for the freezing of donor hearts for years after which it will be unfrozen, 
made to beat and save the life of a needy recepient. Ms Visser, 37, says "
Scientists have for years tried this and got nowhere and here I started and 
there were no huge setbacks." Until now there has success in reviving only 
single cells which have been frozen, such as sperm or eggs. Attempts to 
freeze whole organs in liquid nitrogen have failed because cells have been 
destroyed in the process. As well as developing the formula, the South 
African scientists have succeeded in saturation the cells, using the heart's 
blood vessels. The formula changes the properties of the water in cells and 
this prevents damaging expansion as the heart freezes. The team of medical 
scientists is cautious about celebrating prematurely, but their discovery 
arguably matches, or even surpasses the first heart transplant performed by 
Prof Chris Banard in 1967....

the breakthrough means that transplant surgeons will eventually be able to 
establish heart banks from which they will simply select the appropriate 
organs for the recipient the moment it is required. Patients will no longer 
have to wait for months, or depend on bypass machines for their survival. 
And Prof du Plesis says there is every likelihood that with further research 
their formula will be used to preserve other transplantable organs such as 
kidneys, lungs and corneas. Ill patients will also no longer by bankrupted 
by the costs of life-sustaining procedures. Prof Cilliers, 42, says that in 
the short term the new technology could be used in cases where longer than 
four hours are needed to transpot a heart and perform a transplant. Ms 
Visser has been working on the concept for two years. She embarked on the 
project while assisting a surgeon in establishing a heart valve bank. " Then 
I though, if you can freeze valves to minus 196C, why not hearts", he says.

On advice from various surgeons and specialists, she read all the material 
available on previous research into cryo-preservation and then started 
experimenting...

The first tests on animal hearts were conducted in August and produced 
encouraging results. A pig's heart was frozen to stasis - the state of the 
biological limbo - and then unfrozen. Tests on the heart showed signed of 
electro-cardiographic activity. Ms Visser said they could not warm the 
heart sufficiently for it to start beating steadily. However, the cells were 
undamaged. This encouraged the team to test the tissue from a human heart, 
and once again there was no sign of cell damage. Next a rat heart was 
frozen, unfrozen and then warmed by a special process - and started beating. 
This was the moment of victory for Ms Visser....The little heart beat for 45 
minutes before scientists shut it down. They had seen enough. - Sapa"

Any comments?

James


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