Objective Peri pheral nerve injury is a common cl inical disease, to study the effects of the physical therapy on the regeneration of the injured sciatic nerve, and provide a reference for cl inical treatment. Methods Sixty-four female adult Wistar rats (weighing 252-365 g) were chosen and randomly divided into 4 groups (n=16): group A, group B, groupC, and group D. The experimental model of sciatic nerve defect was establ ished by crushing the right sciatic nerve in groups B, C, and D; group A served as the control group without crushing. At 2 days after injury, no treatment was given in group B, electrical stimulation in group C, and combined physical therapies (decimeter and infrared ray) in group D. At 0, 7, 14, and 30 days after treatment, the sciatic nerve function index (SFI) and the motor nerve conduction velocity (MNCV) were measured, and morphological and transmission electron microscopy (TEM) examinations were done; at 30 days after treatment, the morphological evaluation analysis of axons was performed. Results At 0 and 7 days after treatment, the SFI values of groups B, C, and D were significantly higher than that of group A (P lt; 0.05); at 14 and 30 days after treatment, the SFI value of group D decreased significantly, no significant difference was observed between group D and group A (P gt; 0.05) at 30 days; whereas the SFI values of groups B and C decreased, showing significant difference when compared with the value of group A (P lt; 0.05). At 0, 7, and 14 days after treatment, the MNCV values of groups B, C, and D were significantly lower than that of group A (P lt; 0.05), and there were significantly differences between group B and groups C, D (P lt; 0.05); at 14 days, the MNCV value of group D was significantly higher than that of group C (P lt; 0.05); and at 30 days, the MNCV values of groups B and C were significantly lower than that of group A (P lt; 0.05), but there was no significant difference between group D and group A (P gt; 0.05). At 0 and 7 days, only collagen and l i pid were observed by TEM; at 14 and 30 days, many Schwann cells and perineurial cells in regeneration axon were observed in groups B, C, and D, especially in group D. Automated image analysis of axons showed that there was no significant difference in the number of myelinated nerve fibers, axon diameter, and myelin sheath thickness between group D and group A (P gt; 0.05), and the number of myelinated nerve fibers and axon diameter of group D were significantly higher than those of groups B and C (P lt; 0.05). Conclusion Physical therapy can improve the regeneration of the injured sciatic nerve of rats.
Objective To investigate the effects of icariin and mixed prescri ption of icariin, radix hedysari polysaccharide, and l iquid extracted from earthworm on peri pheral nerve regeneration. Methods Twenty male SD rats weighing (200 ± 10) g were selected and randomized into four groups (n=5 per group): sham operated group (group A), model group (group B), icariin group (group C), and mixed l iquid group (group D). In group A, the left sciatic nerves of the rats were only exposed, and treated at fixed time from the following day with the NS (2 mL/d). In groups B, C, D, the models were made by clamping sciatic nerve and treated with NS, icariin and mixed l iquid, respectively (2 mL/d). The general state ofanimals was observed after the treatment daily. The nerve function index, motor nerve conductive velocity and the morphous and number of myel inated sciatic nerve fibers were measured at 21 days. Results Animals in various groups were all in good state. After 21 days, the weights of rats in groups A, B, C and D were (366.9 ± 14.0), (370.1 ± 16.3), (373.3 ± 19.6) and (374.0 ± 11.4) g, respectively, and there was no significant difference among these groups (P gt; 0.05). For sciatic function index, there was no significant difference between group A and group D (P gt; 0.05), between group B and group C (P gt; 0.05), while there was significant difference between group B and group D (P lt; 0.05). For tibial function index, there was significant difference between group A and groups B, C, D (Plt; 0.05), there was no significant difference between group B and groups C, D (Pgt; 0.05). For peroneal function index, there was no significant difference between group A and groups C, D (P gt; 0.05), between group B and groups C, D (P gt; 0.05). The sciatic motor nerve conductive velocities of group A, B, C and D were (45.0 ± 2.9), (8.0 ± 2.6), (13.4 ± 6.8), and (19.6 ± 9.3) m/s, respectively, there was no significant difference between group B and group C (P gt; 0.05), and there was significant difference between group A and groups B, C, D and between group B and group D (P lt; 0.05). The size of individual myel inated sciatic nerve fibers of regenerated nerves in groups B, C, and D was significantly smaller than that in group A. Comparing with group A, the number of myel inated sciatic nerve fibers in groups B, C, and D was 93.3% ± 35.6%, 90.6% ± 37.1%, and 115.4% ± 40.6%, respectively, but there was no significant difference among four groups (P gt; 0.05). Conclusion Icariin and mixed prescription are safe. The improving peripheral nerve regeneration effect of mixed prescription is more obvious than that of icariin, indicating the comprehensive study of modified formula radixhedysari is necessary to find the effective part or mixture of effective compounds with fixed percentage.
Objective To explore the facilitative effects of different allogenic cells injected into the denervated muscles on the nerve regeneration, the protection of the myoceptor degeneration, and the promotion for rehabilitation of the muscular function. Methods Schwann cells, myoblast cells, and renal endothelial cells were prepared from 400 SD rats aged 7 days and weighing 20.0±2.3 g. Thirty-six adult female SD rats weighing 120-150 g were randomly divided into 4 groups(n=9). Under the asepsis condition, the left ischiadic nerves of all the SD rats were cut off, and the primary suture of the epineurium was performed. After operation, the different corresponding cells were injected into the triceps muscles of the rat calf in each group once per week for 4 times in all. One ml of Schwann cells (1×106/ml) was injected into the rats in Group A; 1 ml of the mixed cells of Schwann cells and myoblast cells (1×106/ml) was injected into the rats in Group B; 1 ml of the extract from the mixed cells of Schwann cells, myoblast cells, and renal endothelial cells (1×106/ml) was injected into the rats in Group C; 1 ml of the culture medium without any serum was injected into the rats in Group D as a control. After operation, observation was made for the general condition of the rats; 3 months after operation, enzymohistochemistry and the CJun expression were performedin the ventricornual motor neuron. At the proximal and the distal ends of the nerve suture, the density of neurilemma cells in the unit area and the area size of the regenerated nerve fibers were observed and measured. Results The affected limbs of the rats in Groups A, B and C improved 13 months after operation. The ulcers and swelling at the ankles gradually relieved and the rats could move normally 3 months after operation. However, the affected limbsof the rats in Group D still had ulcers and swelling, with an obvious contracture of the toes and a difficult movement. Three months after operation, the number of the target muscle myoceptor, the number of the Actin positive cells, the activity of the various enzymes in the denervated muscles, and the histological changes of the regenerated nerves were better in Group C than in Groups A and B (P＜0.01); and they were all better in Groups A, B and C than in Group D（Plt;0.01）. Conclusion Schwann cells, the mixture of Schwann cells and myoblast cells, and the extract from the mixture of Schwann cells, myoblast cells and renal endothelial cells can all promote neurotization and rehabilitation of the muscular function, and protect against the myoceptor degeneration. However, the effect of the extract is superior to that of Schwann cells or the mixed cells.
OBJECTIVE: To study the effects of Schwann cell cytoplasmic derived neurotrophic proteins (SDNF) on the regeneration of peripheral nerve in vivo. METHODS: Ninety adult SD rats were chosen as the experimental model of degenerated muscle graft with vascular implantation bridging the 10 mm length of right sciatic nerve. They were divided randomly into three groups, 30 SD rats in each groups. 25 microliters of 26 ku SDNF (50 micrograms/ml, group A), 58 ku SDNF (50 micrograms/ml, group B) and normal saline(group C) were injected respectively into the proximal, middle and distal part of the degenerated muscle grafts at operation, 7 and 14 days postoperatively. The motorial function recovery assessment was carried out every 15 days with the sciatic nerve function index(SFI) after 15 days to 6 months of operation. Histological and electrophysiological examination of regenerating nerve were made at 1, 3 and 6 months postoperatively. RESULTS: There were significant statistic differences between the both of experimental groups(group A and B) and control group(group C) in the respects of the histological, electrophysiological examination and SFI(P lt; 0.01). CONCLUSION: The 26 ku SDNF and 58 ku SNDF can improve the regeneration of the injured peripheral nerve in vivo.
OBJECTIVE: To explore the mechanism of tissue specificity of neurotropism in peripheral nerve regeneration, we investigated the biological characteristics of the nerve regeneration conditioned fluids(NRCF) on motoneuron of SD rats cultured in vitro. METHODS: Silicon chambers were sutured respectively to the distal stumps of motorial branch of femoral nerve and saphenous nerve to collect NRCF, namely MD-NRCF and SD-NRCF. The rats cortex motoneuron were divided into 4 groups and cocultured with MD-NRCF, SD-NRCF, b-FGF and serum-free medium respectively. The cultured cells were photoed under phase-contrast microscope, their longest neurites and cell-body areas were measured by cell image processing computer system. MTT automated colorimetric microassay was also adopted to quantify the activation of cultured motoneurons in each group. RESULTS: Cells of MD-NRCF group had longer neurites than those of the other three groups, and their activation was also superior to those of the other groups. CONCLUSION: The results suggest that MD-NRCF has more significantly neurite-promoting and neurobiological effects on motoneuron than SD-NRCF and b-FGF.
To observe the effect of percutaneous electrical stimulation on peripheral nerve regeneration, a model was created on the sciatic nerves of 56 rats from either sectioned and followed by direct anastomosis or clamping of the nerve. The indices, such as conducting velocity of nerve, maximal induced action potential of muscle, growth speed of nerve, rateof axon crossing anastomosis site, number of muscular fiber on transverse area and weight of muscle by autocontrol were compared. In this study, 36 rats were divided into two groups, 24 rats in Group 1 and 12 rats in Group 2. In Gourp 1, both sciatic nerves were sectioned and was anastomozed 4 weeks later. One side of the nerve was stimulated with percutaneous electric current, the other side was served as control. In Group 2, both sides of nerves were clamped and the electical stimulationwas carried out on one side. The parameters of the electric current were 2～5HZ, 0.4m/s, 24～48V. The electrophysiological and histomorphological features were observed 1 to 6 weeks after operation. The results showed that in the stimulatedside, the indices were all superior to that of the control side. This suggestedthat electrical stimulation could promote peripheral nerve regeneration.
ObjectiveTo investigate the expression regulation of inflammation cytokines interleukin 4 (IL-4), IL-6, IL-13, and tumor necrosis factor α (TNF-α) in rats with sciatic nerve defect following olfactory ensheathing cell (OEC) transplantation. MethodsThe primary OEC for cell culture and identification was dissociated from the olfactory bulb of the green fluorescent protein-Sprague Dawley (GFP-SD) rat. One hundred SD rats were randomly divided into 2 groups, and the right sciatic nerve defect (10 mm in length) model was made, then repaired with poly (lactic acid-co-glycolic acid) (PLGA). The mixture of equivalent cultured GFP-OEC and extracellular matrix (ECM) was injected into both ends of PLGA nerve conduit in the experimental group (n=55), and the mixture of DMEM and ECM in the control group (n=45). The general situation of rats was observed after operation. At 6 hours, 1 day, 3 days, 1 week, 2 weeks, 3 weeks, 4 weeks, and 6 weeks, the inflammatory cytokines were detected by Western blot. At 2, 4, and 6 weeks, the survival of GFP-OEC was observed in the experimental group. At 9 weeks, HE staining was used to observe the morphology of nerve tissue, and the sensory and motor function and the electrophysiological index were detected. ResultsThe cultured primary cells were GFP-OECs by immunofluorescence staining. Compared with the control group, the experimental group showed significantly increased expression level of IL-4 at 2-6 weeks (P < 0.05), significantly decreased expression level of IL-6 and TNF-α at 3 days and 1 week (P < 0.05) and significantly increased expression level of IL-13 at 1 day and 3-6 weeks (P < 0.05) by Western blot detection. At 2, 4, and 6 weeks, the surviving GFP-OEC of regenerative nerve end was observed in the experimental group under the fluorescence microscope. At 9 weeks, regenerative nerve tissue was loose, and cell morphology was irregular in the experimental group, while the regenerative nerve tissue had vesicular voids and the cell number decreased significantly in the control group. At 9 weeks, the functional recovery of sciatic nerve in the experimental group was better than that of the control group, showing significant difference in the lateral foot retraction time, sciatic nerve function index, muscle action potential latency, and the amplitude of compound muscle action potential (P < 0.05). ConclusionOEC can promote the anti-inflammation cytokines expression of IL-4 and IL-13 and inhibit the pro-inflammatory cytokines expression of IL-6 and TNF-α, which can improve the local inflammatory microenvironment of sciatic nerve and effectively promote the structure and function recovery of sciatic nerve.