No abstract

ABSTRACTgaps by inserting the severed nerve stumps into the two ends of the canal (16). Some natural and synthetic substances can be shaped in structures that are able to promote nerve regeneration for example: eggshell membrane (12), silicone (31), human amnion layer (22), collagen (18), collagen-Chitosan (36).Collagen-based biomaterials have been extensively studied as a promising nerve guide (7). Since collagen is a natural material, it shows excellent biocompatibility, insignificant immunogenicity, and high bio-absorbability (27).█ INTRODUCTION F or peripheral nerve repair, nerve autografts have always been considered as the "gold standard" for the restoration of structural and functional nerve regeneration (34).Autograft has several disadvantages, including the need for an extra-incision, loss of donor nerve function, mismatch in size between the donor nerve and the injured nerve, and a limited availability of donor nerve (33). To solve these problems, nerve guide channels (NGCs) have been made to bridge the nerve AIm: The aim of this study was to evaluate the effect of cerebrospinal fluid (CSF) in nerve regeneration across the collagen guide channel in comparison with autograft. mATERIAl and mEThODS: Forty adult male rats (250-300 g) were randomized into (1) collagen channel+CSF, (2) collagen channel+normal saline (NS), (3) autograft, and (4) sham surgery groups. The left sciatic nerve was exposed and a 10 mm nerve segment was cut and removed. In the collagen groups, the proximal and distal cuts ends of sciatic nerve were telescoped into the nerve guides and CSF or NS injected into collagen conduit. In the autograft group, the 10 mm nerve segment was turned backwards and used an autologous nerve graft. All animals were evaluated by sciatic functional index (SFI) and electrophysiology, histology, and immunohistochemistry testing. RESUlTS:The improvements in SFI since the beginning of the last evaluation in experimental groups were measured. On days 49 and 60 post-operation, the mean SFI of the collagen+CSF group was significantly greater than the autograft group (P< 0.05). On day 90, the mean nerve conduction velocity (NCV) of the collagen+CSF group was greater than autograft group (P< 0.05). The number of myelinated fibers in the collagen+CSF group was significantly greater than that of the collagen + NS group at day 90 (P<0.05).CONClUSION: CSF in collagen nerve guide channel effectively enhances nerve regeneration and promotes functional recovery in injured sciatic nerve of rats.

AIM: To evaluate the effect of different remote ischemic preconditioning (RIPC) methods in spinal cord ischemia-reperfusion (IR) injury. MATERIAL and METHODS:A total of 36 rats were distributed to the 6 groups: sham surgery, control (only spinal cord IR), unilateral (hind limb RIPC before spinal cord IR), bilateral (hind limbs RIPC before spinal cord IR), ipsilateral (hind and fore limbs RIPC to the right before spinal cord IR), contralateral (right hind limb and left fore limb as RIPC before spinal cord IR). Thirty minutes after RIPC, the spinal cord was subjected to ischemia for 60 minutes. Seventy two hours after IR, all rats were evaluated by neurological function, histological and biochemical examinations. RESULTS:The mean Motor Deficit Index (MDI) scores in the ipsilateral, contralateral, and bilateral groups were lower than that of the unilateral group (p<0.05). The mean malondialdehyde (MDA) in ipsilateral group was lower than were control group (p<0.05). The mean total antioxidant capacity (TAC) and the mean number of normal motor neurons in the experimental groups were significantly higher than increased control group (p<0.05). The mean plasma levels of catalase in the contralateral, ipsilateral, and bilateral groups were significantly increased compared to control group (p<0.05). The mean scores of white matter damage in contralateral, bilateral, and unilateral groups were lower than control group (p<0.05). CONCLUSION:The results of this study show that contralateral, ipsilateral, and bilateral limb RIPC may reduce the complications of spinal cord ischemic injury.

No abstract

No abstract