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M Chaouat

Publications and source records attributed to M Chaouat.

39 records · Page 3Linked to original sources

A simplified testing system to evaluate performance after transplantation of human skin preserved in glycerol or in liquid nitrogen.

We have designed and tested a mouse recipient model for evaluation and direct comparison of skin-preservation procedures. Glycerolized skin was compared with cryopreserved and fresh cadaveric skin. Human skin samples were grafted on Balb/c mice, and primary take was evaluated after 4 and 7 days. The results demonstrate that although all grafted specimens were initially accepted as indicated by gross observations, histologic differences were evident and significant. Cryopreserved skin grafts performed better than did glycerolized skin even after a transplantation period as short as 4 days; this difference became even more pronounced after 7 days. Both methods of preservation provided a less successful product than did fresh viable cadaveric skin. However, for very short periods of grafting the performance of glycerolized skin might be considered adequate (79% compared with cryopreserved). Because the present study used an immunocompetent xenogeneic model, it is possible that the period of adequate allogeneic grafting will be prolonged in patients who are immunosuppressed. The present model is simple to use, requires a minimum of maintenance and expertise, and has inherent clinical relevance, because it is concerned primarily with the clinical performance of the skin. Thus it may be used as a quality control test for banked skin.

Animals↗

Phosphorous burns: evaluation of various modalities for primary treatment.

White phosphorus is used in many types of military munitions, in fireworks, and in industrial and agricultural products. It ignites spontaneously and causes deep thermal injuries. It may also cause multiorgan failure because of its toxic effects on erythrocytes, liver, kidneys, and heart. Our previous studies demonstrated deleterious effects of copper sulfate. Only copious water irrigation was effective. This study examined other modalities of treatment and a free oxygen radical scavenger. One of the treatments seemed to have some beneficial effects, but simple water irrigation was much more effective. Superoxide dismutase, a free radical scavenger, reduced hepatic damage and adjacent skin flap destruction but did not prevent death of the animal receiving the high dose of white phosphorus used in the present setup.

Animals↗

Transplantation performance of human skin cryopreserved by programmed or stepwise freezing and stored at -80 degrees C or -180 degrees C.

We developed a mouse recipient model that was used to evaluate and compare four cryopreservation procedures for human cadaveric skin stored for two time periods. Skin specimens were identically processed and preserved by programmed (1 degree C/min), or stepwise freezing, and stored at -180 degrees C or -80 degrees C for periods of 1 month and 6 to 10 months. Samples were grafted on Balb/c mice, and primary take was evaluated after 7 days. The results indicate that although all grafted specimens were initially accepted, as indicated by gross observations, histologic differences were evident and significant. The study groups were analyzed for the effect of method and skin sample variety; the effect of freezing procedure and temperature level; time effect (storage period); and advantage of method 1 (programmed freezing at -180 degrees C) over the other methods. The significance (p value) was determined for separate histologic criteria and average skin score or quality. The overall results indicate that average score of skin preserved by method 1 is highest for both storage periods. This method has an almost significant advantage (p = 0.057) over the others on quality of skin stored for 1 month, and a highly significant advantage (p = 0.007) on graft adherence of skin stored for 6 to 10 months. The effect of method and samples variety on the separate histologic criteria and average score of skin is not always significant. However, an interaction factor (between method and samples) has a highly significant effect (p < 0.001) on almost all of the histologic criteria and average skin score. The effects of freezing method is significant only on average skin score, for 1 month of storage; whereas temperature effect is seldom significant. Evaluating the effects of time, samples, and the interaction factor (between time and samples) indicated that the interaction factor is highly significant (p < 0.001). Time and samples effects are rarely significant. Thus the quality of the final product-the cryopreserved skin-is determined by many factors, and quite often they interact. Highly significant is the combined effect, or interaction factor, of sample variability with method of cryopreservation or with storage period.

Animals↗