[Gamma-rays and XXXX sterilization (author's transl)].

@entity1 @entity11540 @entity2634 @entity1219 @entity19 @entity37771
For many years there was doubt if gamma-irradiated @entity2634 materials could be sterilized with @entity11540 . It was feared that toxic concentrations of @entity37771 ( @entity37771 ) might originate with this procedure. We investigated the various possibilities of @entity37771 formation. Gamma-irradiated @entity2634 tubes were resterilized with @entity11540 and the @entity37771 concentrations determined by gas chromatography. The @entity37771 concentrations at the end of sterilization ranged from 240 to 436 ppm depending upon the composition of the tubes. After 4 d they ranged from < 5 to 280 ppm and after 21 d from < 5 to 218 ppm. For comparison were examined @entity2634 tubes which were not gamma-irradiated but @entity11540 sterilized only. We extracted < 5 to 23 ppm @entity37771 from them. @entity2634 tubes gas sterilized only and retaining 44 to 9300 ppm @entity11540 were submerged in physiological @entity1219 solution for 2 h. The @entity37771 concentrations formed by this procedure ranged from 43 to 75 ppm. After 4 d aeration before begin of extraction they decreased to < 5, 10 and 16 ppm. @entity2634 tubes aerated for 5 or 7 d, containing at least 236 ppm @entity37771 did not demonstrate any effect upon cultures of @entity1 fibroblasts. The toxic concentrations of @entity37771 in our own animal- and cell culture experiments were 12 000 ppm or higher. Other investigators found no damaging effect on @entity19 fibroblasts by adding 20 000 ppm @entity37771 . It appears to be sufficiently proven that gamma-irradiated @entity2634 items may be resterilized with @entity11540 and used in @entity1 provided they they have been adequately aerated.
