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Objective:To investigate the effect of endogenous neurotrophic factor (ENTFs) on nerve regeneration after cryopreserved sciatic nerve allograft in rats. Methods:The 15-mm sciatic nerves from female Sprague-Dawley rats were placed in DMEM solution and pretreated in vitro for 1 day, 3 days, 7 days, 14 days, and 21 days at 37 ℃ with 5% CO2 (groups A, B, C, D and E) respectively. Fresh nerve group (group F) was set up. The protein expression of glial cell line-derived neurotrophic factor (GDNF), nerve growth factor (NGF), Bcl-2, Bax, Caspase-3, major histocompatibility complex (MHC)-I and MHC-II was detected by Western blotting. The above six groups were cryopreserved in liquid nitrogen for four weeks. The living cells and dead cells of the nerves after cryopreservation were observed by Calcein-AM/propidium iodide staining. In addition, the above six cryopreserved groups and another fresh nerve group (group G) were transplanted to the Wistar rats by allografting (groups A', B', C', D', E', F' and G'). Isograft group (group H') was set up. One week after transplantation, the expression of CD8+ T cells and macrophages of the graft were observed by immunofluorescence staining, and the plasma levels of interleukin (IL)-2, interferon (IFN)-γ, and tumor necrosis factor (TNF)-α were detected by ELISA. Twenty weeks after transplantation, the compound muscle action potential (CMAP) and nerve conduction velocity (NCV) were examined by electrophysiology. The wet weight ratio of gastrocnemius muscle was calculated by the operational side compared with the contralateral side. The expression of neurofilament protein (NF) 200 of the transplanted nerves was observed by immunofluorescence staining. The number of myelinated nerve fibers was analyzed by toluidine blue staining. The thickness of myelinated was analyzed by electron microscopy. Results:Compared with group F, the protein expression of GDNF and NGF increased in groups C, D and E (P < 0.05); the protein expression of Bcl-2 reduced and the protein expression of Bax and Caspase-3 increased in groups B, C, D, and E (P < 0.05); the protein expression of MHC-I and MHC-II decreased in all the pretreated groups (P < 0.05). Four weeks after cryopreservation, compared with groups F and G, the number of living cells decreased in groups C, D and E. One week after transplantation, compared with groups F' and G', the expression of CD8+ T cells and macrophages decreased, and the plasma concentration of IL-2 and TNF-α decreased in groups C', D' and E' (P<0.05). Twenty weeks after transplantation, CMAP, NCV, the wet weight ratio of gastrocnemius muscle, the number of axon and thickness of myelin sheath were better in groups C', D' and E' than in groups F' and G' (P<0.05), as well as the expression of NF200. Conclusion:ENTFs can be induced by pretreating the sciatic nerve in vitro. Cryopreserved sciatic nerve with high expression of ENTFs could promote nerve regeneration and functional recovery after allograft.
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<p><b>OBJECTIVE</b>To observe the effect of Liuweidihuang Pills in relieving cellphone electromagnetic radiation-induced histomorphological abnormality, oxidative injury, and cell apoptosis in the rat testis.</p><p><b>METHODS</b>Thirty adult male SD rats were equally randomized into a normal, a radiated, and a Liuweidihuang group, the animals in the latter two groups exposed to electromagnetic radiation of 900 MHz cellphone frequency 4 hours a day for 18 days. Meanwhile, the rats in the Liuweidihuang group were treated with the suspension of Liuweidihuang Pills at 1 ml/100 g body weight and the other rats intragastrically with the equal volume of purified water. Then all the rats were killed for observation of testicular histomorphology by routine HE staining, measurement of testicular malondialdehyde (MDA) and glutathione (GSH) levels by colorimetry, and determination of the expressions of bax and bcl-2 proteins in the testis tissue by immunohistochemistry.</p><p><b>RESULTS</b>Compared with the normal controls, the radiated rats showed obviously loose structure, reduced layers of spermatocytes, and cavitation in the seminiferous tubules. Significant increases were observed in the MDA level (P < 0.01) and bax expression (P < 0.01) but decreases in the GSH level (P < 0.01) and bcl-2 expression (P < 0.01) in the testis issue of the radiated rats. In comparison with the radiated rats, those of the Liuweidihuang group exhibited nearly normal testicular structure, significantly lower MDA level (P < 0.05), bax expression (P < 0.01), and bcl-2 expression (P < 0.01).</p><p><b>CONCLUSION</b>Liuweidihuang Pills can improve cellphone electromagnetic radiation-induced histomorphological abnormality of the testis tissue and reduce its oxidative damage and cell apoptosis.</p>