Functional recovery of sciatic nerve through inside-out vein graft in rats

Objective： Present study aimed at further comprehensive functional, histomorphometrical and immunohistochemical assessment of peripheral nerve regeneration using rat sciatic nerve transection model.Methods： The 10-mm rat sciatic nerve gap was created in rats. In control group nerve stumps were sutured to adjacent muscle and in treatment group the gap was bridged using an inside-out vein graft. In sham-operated group the nerve was manipulated and left intact. All animals underwent walking track analysis test 4, 8, and 12 weeks after surgery.Subsequently, muscle mass measurement was performed to assess reenervation, histological examination to observe the sciatic nerve regeneration morphologically and immunohistochemistry to detect Schwann cells using anti S-100. Results were analyzed using a factorial ANOVA with two between-subjects factors. Bonferroni test for pairwise comparisons was used to examine the effect of treatments.Results： Functional analysis ofmyelinated nerve fibers showed that nerve function improved significantly in the time course in treatment group. However, quantitative morphometrical analysis of myelinated nerve fibers showed that there was no significant difference between 8 and 12 weeks in treatment group. Muscle weight ratio was bigger and weight loss of the gastrocnemius muscle was ameliorated by inside-out vein grafting. The position of positive immunohistochemical reactions further implied that regenerated axons and Schwann cell-like cells existed after vein grafting was performed, and was accompanied by the process of myelination and structural recovery of regenerated nerves.Conclusion： Functional analysis of peripheral nerve repair is far more reliable than quantitative morphometrical analysis

Effect of local administration of cyclosporine A on pe- ripheral nerve regeneration in a rat sciatic nerve transec- tion model

Objective： To assess the effect of cyclosporine A （CsA） loaded in chitosan conduit on bridg- ing the sciatic nerve defects in a rat model. Methods： A 10 mm sciatic nerve defect was bridged using a chitosan conduit filled with 10 μl carrier-drug dilu- tion （10 pg/L CsA）. In control group, the conduit was filled with the same volume of carrier dilution alone. The regene- rated fibers were studied 4, 8 and 12 weeks after surgery. Results： The functional study confirmed faster recov- ery of the regenerated axons in treatment group than control group （P〈0.05）. There was statistically significant differ- ence of the gastrocnemius muscle weight ratios between treatment and control groups （P〈0.05）. Morphometric indi-ces of regenerated fibers showed that the number and diam- eter of the myelinated fibers in CsA-treated animals were significantly higher than those in control group. In immunohistochemistry, the location of reactions to S-100 in CsA group was clearly more positive than control group. Conclusion： CsA loaded in a chitosan conduit results in improvement of functional recovery and quantitative mor- phometric indices of sciatic nerve. It is easily available with- out any complications compared with its systemic administration.

A Kernel Function Based Interior-Point Methods for Solving P_*(κ)-Linear Complementarity Problem

In this paper, motivated by the complexity results of Interior Point Methods （IPMs） for Linear Optimization （LO） based on kernel functions, we present a polynomial time IPM for solving P.（a）-linear complementarity problem, using a new class of kernel functions. The special case of our new class was considered earlier for LO by Y. Q. Bai et al. in 2004. Using some appealing properties of the new class, we show that the iteration bound for IPMs matches the so far best known theoretical iteration bound for both large and small updates by choosing special values for the parameters of the new class.

Local effect of celecoxib on peripheral nerve repair com- bined with silicone tubulization in rat

Objective： To assess local effect of celecoxib on nerve regeneration in a rat sciatic nerve transec- tion model. Methods： Forty-five male healthy white Wistar rats were randomly divided into three experimental groups （n= 15 for each）： sham-operation （SHAM）, control （SIL） and celecoxib treated （SIL/CLX） groups. In SHAM group after anesthesia left sciatic nerve was exposed and after homeo- stasis muscle was sutured. In SIL group the left sciatic nerve was exposed in the same way and transected proximal to tibioperoneal bifurcation leaving a 10 mm gap. Proximal and distal stumps were each inserted into a silicone tube and filled with 10 gl phosphate buffered solution. In SIL/CLX group defect was bridged using a silicone tube filled with 10 μl celecoxib （0.1 g/L）. Results： Functional study and gastrocnemius muscle mass confirmed faster and better recovery of regenerated axons in SIL/CLX than in SIL group （P〈0.05）. Morphometric indices of regenerated fibers showed number and diameter of the myelinated fibers in SIL/CLX were significantly greater than those in control group. In immunohistochemistry, lo- cation of reactions to S-100 in SIL/CLX was clearly more positive than that in SIL group. Conclusion： Response to local treatment ofcelecoxib demonstrates that it influences and improves functional re- covery of peripheral nerve regeneration.

Vascular endothelial growth factor promotes peripheral nerve regeneration after sciatic nerve transection in rat

Objective：To evaluate the local effect of vascular endothelial growth factor （VEGF） on transected sciatic nerve regeneration.Methods：Sixty male white Wistar rats were divided into four experimental groups randomly （n=15）.In transected group the left sciatic nerve was transected and the stump was fixed to adjacent muscle.In treatment group the defect was bridged using a silicone graft filled with 10μL VEGF.In silicone group the graft was filled with phosphate-buffered saline.In sham-operated group the sciatic nerve was exposed and manipulated.Each group was subdivided into three subgroups with five animals in each and nerve fibers were studied 4,8 and 12 weeks after operation.Results：Behavioral test,functional study of sciatic nerve,gastrocnemius muscle mass and morphometric indices confirmed a faster recovery of regenerated axons in VEGF group than in silicone group （P〈0.05）.In immunohistochemical assessment,reactions to S-100 in VEGF group were more positive than that in silicone group.Conclusion：Local administration of VEGF will improve functional recovery and morphometric indices of sciatic nerve.