X-Message-Number: 9554
Date: Mon, 27 Apr 1998 20:23:26 -0400
From: Jan Coetzee <>
Subject: Re: CryoNet #9549 - #9551
References: <>

I think they have inadvertently selected for cells that are more resistant to
hypothermia. In cell culture you divide the cells and reseed them often.
J.C.

"The technique of organ preservation is limited by the amount of time which
  organs can be hypothermically stored. A potential method to effectively
  extend reliable storage times involves the conditioning of cells to better
  withstand hypothermia by previous exposure to a less severe stress. Using
  human fibroblasts in culture, we have demonstrated that such an approach may
  be feasible. Subjecting human diploid IMR-90 fibroblasts to 5 h 42.5 degrees
  C heat shock was found to improve cell survival more than 10-fold to
  subsequent 4 degrees C hypothermic exposure. The prior heat shock resulted in
  the increased synthesis of heat shock proteins (HSPs), the absolute
  concentrations of which were measured by an assay which utilized sodium
  dodecyl sulfate-polyacrylamide gel electrophoresis and Western blotting
  techniques. Both the degree of cold tolerance conferred upon IMR-90 cells and
  the levels of HSP27 and HSP27 were dependent upon initial heat shock
  duration. Induced cold tolerance was found to be reversible; longer recovery
  times at 37 degrees C following heat shock resulted in a loss of this
  cold-tolerant state as well as a disappearance of HSPs. The fact that the
  degree of cold tolerance and HSP concentrations showed similar trends with
  respect to both heat shock time at 42.5 degrees C and subsequent recovery
  time at 37 degrees C suggests that these proteins may be intimately involved
  in the induction of cold tolerance."

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