RESUMO
Objective: To investigate the effects of immunosuppression treatment on peripheral nerve injury and regeneration in rats. Methods: Forty-nine SD rats were randomly divided into 7 groups: sciatic nerve (in the middle of left thigh) forceps-crushing+cyclophosphane, transecting+cyclophosphane, resecting groups+cyclophosphane, forceps-crushing+normal saline, transecting+normal saline, resecting groups+normal saline, and blank control groups. Cyclophosphane and normal saline were intraperitoneally injected into rats post-operatively. Peripheral nerve regeneration and its related function were assessed by walking track analysis, electrophysiology and histomorphology; immunohistochemistry method was used to evaluate the local autoimmune reactions 12 weeks after operation. Results: Cyclophosphane treated animals had higher scores of sciatic function index (SFI) compared to animals in the corresponding normal saline groups. The electrophysiological (nerve conduction velocity) and morphological examinations showed better regeneration of the myelinated axons in immunosuppression-treated animals compared to the corresponding normal saline groups. The immunohistochemistry showed that the intensities of the local immunological response in immunosuppression groups were obviously lower as compared to the corresponding normal saline groups. Conclusion: There is local autoimmune reaction in post-traumatic nerve regeneration and this autoimmune reaction may influence nerve regeneration. Cyclophosphane treatment can suppress this autoimmune reaction and improve the micro-environment for nerve regeneration.
RESUMO
<p><b>OBJECTIVE</b>To investigate the effects of chitosan on the biological activities of the fibroblasts derived from different tissues.</p><p><b>METHODS</b>The biological activities of the fibroblasts derived from different tissues were evaluated with a MTT method for fibroblast proliferation, photic and electronic microscope for morphologic and subcellular structure, 3H-proline uptake method for collagen secretion and ELISA box for the secretion of TGF-beta 1, FGF-AB, and IL-8.</p><p><b>RESULTS</b>This study showed that the chitosan inhabited the proliferation of the fibroblasts and the secretion of the TGF-beta 1, FGF-AB and collagen of the fibroblasts with a dose-depended manner in the normal skin, hypertrophic scar and keloid groups, but it stimulated the IL-8. However, there were no significant differences among the three groups (P > 0.05).</p><p><b>CONCLUSION</b>The chitosan could inhibit the growth, proliferation, biosynthesis and secretion of the fibroblasts, and it may be used to treat different scars.</p>