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"Organs Safely Put on Ice" article


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#1 iambhall

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Posted 13 May 2004 - 01:26 AM


Here's an article about some of the latest research going on at 21st Century
Medicine.

http://www.betterhum...ID=2004-05-12-4

The article doesn't say too much new except:
"Company researchers have now tested a compound called M22 that was fatal
when added and removed at -22 C but nonfatal when perfused for 25 minutes
at -22 C and washed out simultaneously with warming.When kidneys perfused
with M22 at -22 C were further cooled to about -45 C, they all supported
life after transplantation."

Here is the abstract reported in the journal Cryobiology:
http://www.sciencedi...5-4C4W32F-1&_co
verDate=04%2F30%2F2004&_alid=171610856&_rdoc=1&_fmt=&_orig=search&_qd=1&_cdi
=6757&_sort=d&view=c&_acct=C000050221&_version=1&_urlVersion=0&_userid=10&md
5=0e948962ed3ba1014c1d19a9bb89c90f

-Bryan Hall

#2 alex83

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  • Location:Israel

Posted 20 May 2004 - 07:13 PM

Organs Safely Put on Ice
Scientists a step closer to preserving them at very cold temperatures
By Keri Schram
Betterhumans Staff
5/12/2004 5:38 PM

Credit: Marcel Hol
Cold storage: New cell-protecting solutions are bringing scientists closer than ever to long-term organ preservation

Scientists have come a step closer to successfully preserving organs at extremely cold temperatures without damaging them.

Until now, attempts to cryopreserve whole organs have largely failed because the cells are often killed or damaged during the freezing and thawing processes.

Researchers at 21st Century Medicine in Rancho Cucamonga, California have now reported freezing one rabbit kidney for 25 minutes at -22°C and another at -45°C in a process that left them apparently able to support life.

Deep freeze

Cryopreservation is a process in which organs or tissues are preserved by cooling them to extremely cold temperatures of down to -196°C with liquid nitrogen.

The cooling process puts cells in suspended animation so that biochemical reactions that cause cell death are slowed or stopped.

Freezing organs is desirable for the creation of organ banks and the improvement of critical organ transplants.

The freezing process has proven challenging, however, because organs are damaged during cryopreservation by two phenomena: solution effects and intracellular ice formation.

Solution effects are caused by the build up of solutes in non-frozen solution as they are excluded from the crystal structure of ice.

Cell damage from intracellular ice formation occurs when ice crystals damage cells like ragged broken glass.

Overcoming obstacles

Researchers at 21st Century Medicine aim to get around these problems using vitification, an ice-free cryopreservation technique in which chemicals are used to cool organs without disturbing their cellular structure.

They are using cryoprotectant solutions that are typically made from glycerol, dimethyl sulfoxide or ethylene glycol.

Company researchers have now tested a compound called M22 that was fatal when added and removed at -22°C but nonfatal when perfused for 25 minutes at -22°C and washed out simultaneously with warming.

When kidneys perfused with M22 at -22°C were further cooled to about -45°C, they all supported life after transplantation.

It's still unclear, however, if the organs were permanently damaged during the thawing process.

Prospects promising

The researchers are planning to examine whether improving the cryoprotectant solutions or thawing the organs at higher rates will help prevent damage.

"In conclusion, although the goal of organ vitrification remains elusive, the prospects for success have never been more promising," say the study authors.




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