| The neural defection because of peripheral neural injuries is prev-alent in clinics, autotransplantation has been the main therapeutic method. However, due to the scarceness of neural source and such complication as pain, numbness , scar et al in donor site, this applica-tion is limited. So allograft of nerves appeares. But it has also its de-fection , for example the immune rejection can cause connective tissue proliferation which in turn make failure of neural regeneration. Studies showed that hypothermia was a kind of solution. We applied bFGF complex degradation membrane in the injury site in hypothermia envi-ronment to promote the rate of neural regeneration so that the regener-ation rate surpassed that of immune rejection and connective tissue proliferation.Materials1. Animals;54 SD male and female rats in animal breeding center of CMU,weighing 350 -500 gram 2L Main instruments: electromyographic device, image analysis device ;Leca DMLB electron microscope ;H-7100 Hitachi microscope: Olympus BH2 - RFCAdeep -freeze refrigerator FORMA MODEL 925 3. Reagent:bFGF complex degradation membrane with low time - release from chemical research agency in Chendu.Methods54 rats were divided into 3 groups with all rats'2 cm of sciatic nerve cutted off in right lower limb. The nerve segment was then stored in - 8Ot for 10 days for transplatation. Group A; the nerve segment was treated with bFGF and Vc liquid and coated with bFGF membrane after transplanted. Group B; nerve segment was coated with membrane not containing bFGF. Group C: nerve segment was only transplanted. A series of studies were conducted after 90 days and 180 days after oper-ation including histological observation under light and electronic mi-croscope, imaging analysis, structure changes of blood nerve barrier, electrophysiologic test, adhesive quantitive observation et al.2. Statistical significance was calculated by T test and analysis of variance with SPSS software.Results1. Gross observation: the nerve segment in group A was smoother and thicker than that in group B and C, and the suture site showed slighter enlargement and continuousness with connective tissue.2. Microscope observation; osmate and weil dyeing showed that the amount of sheathed fiber in group A was larger than that in group B and C,and the thickenss of the fiber is thicker in group A. There isno significant difference between group B and C. Under electron micro-scope, the development of the sheath is better than that in group B and C.3. The blood nerve barrier:the nerve adventitia showed HRP posi-tive reaction (brown staining). 90days after operation the nerve fiber in group A showed slighter HRP staining than group B and C. 180 days after operation,the negative reaction existed in almost all nerve fiber in group A suggested that the restoration of blood nerve barrier is quicker than group B and C.4. image analysis: 180 days after operation, the amount of nerve fiber at proximal and distal segment in group A is significantly higher than that in group B ( P < 0. 001). There is no significant relationship between group B and C which suggested that bFGF may promote re-generation of nerve. The study about the diameter of sheathed nerve fi-ber 180 days after operation also showed that bFGF could promote the development of nerve fiber.5. Adhesive quantitive test; 90 days after operation the adhesive degree in group A is significantly lighter than that in group B and C. (P<0.01)6. electrophysiological factors factors; 180 days after operation the latent period and amplitude of Gastrocnemius muscle showed : (J) the latent period in group A was shorter than that in group B and C which meant a faster transmission in group A (2) A higher amplitude in group suggested a better regeneration effect existed.DiscussionTransplantation of xenogeneic nerve fiber under hypothermia en-vironment could promote regeneration of nerve fiber by inhibiting its antigenicity,however,there is still a long way to apply it in clinics b...
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