OBJECTIVE To observe the degeneration and regeneration of the Meissner’s corpuscles after implanted sensory nerve into the denervated monkey’s fingers under electron microscope. METHODS The two finger nerves of the monkey’s fingers were denervated. Afterwards, one finger nerve was cut off, and the other was reimplanted into the denervated finger. After 1, 3, 5, 8 and 12 months, the finger skin was cut off and observed under electron microscope. RESULTS The degenerative changes of nerve ending in Meissner’s corpuscles were observed after 1 month of denervation, and the basic structure of the corpuscles had no obvious changes. After 3 months, the axons of corpuscles were disappeared, and the volume of corpuscles was shrunk. The basic structure of nerves was disappeared, and the lemmocyte and neurolemma plate were changed after 5 months. The collagen fibrils in the corpuscles were gradually increased in 8 months, the endoneurial structure and interneurial matrix were completely disappeared and replaced by collagen fibrils in 12 months. After 3 months of nerve implantation, unmyelinated nerve fibers were appeared and grew into the corpuscles. A part of corpuscles innervated in 5 months. Most of corpuscles innervated and myelinated nerve fibers were observed in 8 months. And in 12 months, corpuscles innervated to normal level. CONCLUSION The implantative sensory nerve by means of reinnervating the original corpuscles and regenerating new corpuscles could innervate the degenerative Meissner’s corpuscles.
Membrane guided tissue regeneration is new biological concept. The basic theory of this concept includes the belief that during the healing process of wound, the different cells will show different speed of cell migration and regeneration in the wound. If an appropriate membrane being placed to form a mechanical barrier, so that only the needed cells can grow into that area and prevent others from going in, thus resulting in the creation of a guided area where the needed cells can undergo proliferation and differentiation under protection in completing an ideal tissue regeneration and repair. In this article, the experimental researches on the application of membrane guided tissue regeneration in the repair of tubular bone defects, skull defects and faciomaxillary defects were reviewed from literatures, and the degradable and non-degradable materials were introduced, particularly. The pros and cons of this method and the materials were evaluated. It is believed that this technique will push forward the progress in bone biology and reconstructive surgery.
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 investigate a new composite matrix (BMSCs seeded on the denuded human amniotic membrane, BMSCs-DHAM) bridging the both stumps of spinal cord injury in rats to promote axon regeneration and improve motor function of hind l imbs. Methods The human amniotic membrane (HAM) was voluntarily donated by the healthy pregnant women after a caesarean section. The cells on the HAM were completely removed with a tryptic and mechanical approach to prepare DHAM. The BMSCs were separated and cultured from 4-week-old female rats (n=4), then the forth passage of BMSCs were labeled by PKH26 and seeded on DHAM (BMSCs-DHAM). The growing state of BMSCs was observed under themicroscopy. Moreover, 40 female rats (8-week-old, weighting 200-220 g) were made spinal cord injury models by transecting at T9 level, and were randomly divided into 4 groups (each group, n=10). The both stumps were respectively wrapped by BMSCs- DHAM or simple DHAM in groups A and C, and the same dose of BMSCs or physiological sal ine were also respectively injected the central lesion in groups B and D. At 12 weeks after surgery, the functional recovery of the hindl imbs was evaluated by the BBB locomotor rating score, and other indexes were tested including cortical motion evoked potential (MEP), anterograde biopinylated dextan amine (BDA) tracing, and immunofluorescence of neurofilament protein 200 (NF-200). Results HE staining proved that the DHAM was devoid of cellular components by this way, and BMSCs grew well on the substrate under the microscopy. At 12 weeks after operation, the BBB score (12.50 ± 1.26) in group A was significantly higher than those of other groups (P lt; 0.05), and the recovery in latency (3.52 ± 2.45) ms and ampl itude (480.68 ± 18.41) μV of MEP was also obviously improved in group A (P lt; 0.05) when compared with other groups. In addition, anterograde BDA tracing revealed that the rate of the positive BDA axons 54.12% ± 3.30% under the lesion level in group A was higher than those of other groups (P lt; 0.05), and lots of the regeneration axons (positive NF-200) were found to grow into the spinal cord under the composite matrix in group A. Conclusion The BMSCs-DHAM composite matrix can improve hindl imb motor function to some extent after spinal cord injury. It will be widely appl ied as the matrix material in the future.
ObjectiveTo evaluate the effect of heparin binding epidermal growth factor-like growth factor (HB-EGF) on liver regeneration after partial orthotopic liver transplantation. MethodsFourty SD rats were used to establish the model of partial orthotopic liver transplantation with ameliorated two-cuff technique. Then all the rats were divided into 2 groups: experiment group and control group. Twenty rats of experiment group were administered 500 μg/kg HBEGF via vena caudalis immediately after operation twice a day, while the same volume of saline was administered to the rats in control group. Five rats in each group were selected randomly and killed at the 6th hour, day 2, 4 and 7 after operation, respectively. The serum levels of albumin (Alb) and alanine aminotransferase (ALT) in the blood sample were detected. Every liver was removed and weighed. The expression of Ki67 was detected by using immunohistochemistry assay. The regeneration activity of hepatocytes was evaluated by flow cytometry. ResultsThe wet weights of liver in experiment group were all significantly higher than that in control group at the 6th hour, day 2 and 4 after transplantation (P＜0.05). The serum levels of ALT were significantly lower in experiment group than those in control group at the 6th hour, day 2， 4, 7 after operation (P＜0.05), while the levels of Alb were significantly higher on day 4 and 7. The proliferating index and Ki-67 labeling index of graft in experiment group were higher than those in control group on day 2 and 4 after transplantation （2 d: P＜0.01; 4 d: P＜0.05）. ConclusionHBEGF could promote the regeneration of rat hepatocytes after partial liver transplantation.
【Abstract】 Objective To study liver regeneration of the non-ligated liver lobes following portal branch ligation (PBL). Methods Sixty male Wistar rats were randomly divided into PBL group and sham operation (SO) group. Under ether anesthesia, the rats were subjected to PBL and sham operation, respectively. The animals were sacrificed on the 1st, 2nd, 3rd, 7th and 14th day respectively. The blood sample was collected from heart and the livers were harvested to determine serum alanine aminotransferase (ALT) levels and total liver weight, respectively. The hepatic histopathology was studied through light microscopy. The number of liver cell nuclear mitosis index was counted. The number of proliferative cell nuclear antigen (PCNA) index was counted by immunohistochemistry. The hepatic ultrastructural changes were studied under electron microscope. Results ①Elevated serum ALT level was observed in the first postoperative day in PBL group compared with SO group (P＜0.01)， but began to recover in the second day. ②No significant total liver weight change in PBL group and SO group were found. ③Liver cell nuclear mitosis index and PCNA index were markedly increased in PBL group compared with SO group in day 1-3 postoperative day (P＜0.01). It reached the peak in the second day and decreased slightly in the 3rd day, but still higher than SO group, then gradually return to normal lately. Conclusion The ligation of left portal branch can induce active regeneration of hepatic cell of non-ligated liver lobes in rats. The regeneration of non-ligated liver lobes may restore previous total liver weight. The ligation of 75% portal branch does not affect liver function and may be safely performed. The portal branch ligation in rats may be used as an animal model in study of liver regeneration.
ObjectiveTo investigate the effect of cells in the epimysium conduit (EMC) on the regeneration of sciatic nerve of mice.MethodsThe epimysium of the 8-week-old male C57BL/6J enhanced green fluorescent protein (EGFP) mouse was trimmed to a size of 5 mm×3 mm, and prepared in a tubular shape (ie, EMC). Some epimysia were treated with different irradiation doses (0, 15, 20, 25, 30, 35 Gy) to inhibit cells migration. Then the number of migrating cells were counted, and the epimysia with the least migrating cells were selected to prepare EMC. Some epimysia were subjected to decellularization treatment and prepared EMC. HE and Masson staining were used to identify the decellularization effect. Twenty-four C57BL/6J wild-type mice were used to prepare a 3-mm-long sciatic nerve defect of right hind limb model and randomly divided into 3 groups (n=8). EMC (group A), EMC after cell migration inhibition treatment (group B), and decellularized EMC (group C) were used to repair defects. At 16 weeks after operation, the midline of the regenerating nerve was taken for gross, toluidine blue staining, immunofluorescence staining, and transmission electron microscopy.ResultsAt 15 days, the number of migrating cells gradually decreased with the increase of irradiation dose. There was no significant difference between 30 Gy group and 35 Gy group (P>0.05); there were significant differences between the other groups (P<0.05). The epimysium after treatment with 35 Gy irradiation dose was selected for thein vivo experiment. After the decellularization of the epimysium, no nucleus was found in the epimysium and the epimysium could be sutured to prepare EMC. At 16 weeks after operation, the nerves in all groups were recanalized. The sciatic nerve was the thickest in group A, followed by group B, and the finest in group C. Immunofluorescence staining showed that the EGFP cells in group A were surrounded by regenerated axons. Toluidine blue staining and transmission electron microscopy observation showed that the number of regenerated axons and the thickness of regenerated myelin sheath in group A were significantly better than those in groups B and C (P<0.05). There was no significant difference between groups B and C (P>0.05).ConclusionThe cellular components of the epimysium participate in and promote the regeneration of the sciatic nerve in mice.
Objective To know the possibility of nerveregeneration after artery sleeve anastomosis and end-to-side suture Methods Seventy-five SD rats were divided into 5 groups. First, the distal end ofsevered peroneal nerve was sutured end-to -side with artery sleeve anastomosis withnormal nerve tibial trunk in groups A, B, C and D. Second, the tibial epineurium at the suture site was not removed in group A; the epineurium at the suturesite was removed(windowing) in group B; the distal end of pre-injured peroneal nerve was sutured after 14 days and windowing was done in group C; and the neural growth factor was injected into artery sleeve and windowing was done in group D. While the distal end of severed peroneal nerve was sutured end to side directly with normal nerve tibial trunk and windowing was done in group E. The histological observation was made and the number of nerve fibers was recorded after 4, 8 and 12 weeks of operation.Results After 4 weeks, there existed the regeneration of axons and myeline sheaths in groups C, D, E, and no nerve fiber regeneration was seen in group A. After 8 weeks, the regenerating nerve fibers were significantly more in groups C, D and E than in group B and ingroup E than groups C and D(Plt;0.05). After 12 weeks, the regenerating nervefibers were significantly more in groups C，D and E than in group B(Plt;0.05).Conclusion End-to-side coaptation with artery sleeve anastomosis is a new valuable method in repair of peripheral nerve injuries.
Objective To make a histological evaluation of poly(dextrogyr-levogyr)lactide acide-triiodothy-ronine (PDLLA-T3) in sciatic nerve defect of rat. Methods Ninety SD rats were evenly divided into 3 groups (autograft group A, PDLLA-T3 group B and PDLLA group C). Group D was control group. The left sciatic nerves were cut off by operation and 1 cm-nerve-defect was set up. The specimens were collected 2 weeks,1 month and 2 months after the operation respectively, simultaneously the right sciatic nerves were collected as normal control group D. HE stainning, electron microscope, S100 immunohistochemistry, and Bielschowsky staining were done in all the specimens, the quantity and quality of the regenerated nerves were observed, and all the results were processed by image analyzer.Results Two weeks after the operation,histological observation indicated that the materials in groups B and C were not completely degraded. Transmission electron microscopic observationshowed that the myelin sheath was not thick and it was about 0.5 μm in thickness. There was no significant difference among the 3 groups. One month after theoperation, histological observation indicated that in group A the regenerated nerves passed through the scaffold and in the new nerves there were regenerated blood vessels. The materials in groups B and C were not completely degraded. S-100 immunohistochemical observation and Bielschowsky staining showed that in groupB PDLLA-T3 repaired the defect successfully and the regenerated nerve myelinsheath was 1.81±0.19 μm in thickness. The effect in group B was better thanthat of groups A and C (P＞0.05). Two months after the operation, the materials in groups B and C were completely degraded. The quantity of the regeneratednerves in group B confirmed by S-100 immunohistochemical observation and Bielschowslcy staining was more than that in group C(P＜0.05) and close to that in group A. The regenerated nerve myelin sheath in group B was 2.15±0.27 μm in the thickness and was thicker than that in group C (P＜0.05)， but thinner than that in groups A and D (P＜0.05). Conclusion PDLLA-T3 can repair the defect of rat sciatic nerve with satisfactory quantity andquality of regenerated nerves.
Objective To study the effect of autogenous bone marrow on guided bone regeneration (GBR),and evaluate the repairing ability of GBR in bone defect with autogenous bone marrow. Methods Ten mm segmental defects were produced in both radii of 18 rabbits. The defect was bridged with a silicon tube. Autogenous bone marrow was injected into the tube on the experimental group at 0, 2,4 weeks after operation, and peripheralblood into the control group at thesame time. The X-ray, gross, histological and biochemical examinations were observed invarious times. Results The new bone formation of experimental group was prior to that of control group; calcium and alkaline phosphatase of experimental groupwere higher than those of control group. The experimental group had all been healed at the tenth week, but no one healed in control group. Conclusion It can be conclude that autogenous bone marrow can stimulate bone formation and facilitate GBR in bone defect.
