Objective To review the research progress on the role of Schwann cells in regulating bone regeneration. MethodsThe domestic and foreign literature about the behavior of Schwann cells related to bone regeneration, multiple tissue repair ability, nutritional effects of their neurotrophic factor network, and their application in bone tissue engineering was extensively reviewed. ResultsAs a critical part of the peripheral nervous system, Schwann cells regulate the expression level of various neurotrophic factors and growth factors through the paracrine effect, and participates in the tissue regeneration and differentiation process of non-neural tissues such as blood vessels and bone, reflecting the nutritional effect of neural-vascular-bone integration. ConclusionTaking full advantage of the multipotent differentiation ability of Schwann cells in nerve, blood vessel, and bone tissue regeneration may provide novel insights for clinical application of tissue engineered bone.
Abstract In order to investigate the mechanism ofregeneration of lymphatic vessel, the regulatory control of various cell factors on the new born bovine lymphatic endothelial cell (NBLEC) was observed. The cell factors used for investigation were bFGF, TGFα, EGF, TNFα and IL-1α. The results showed that bFGF, TGFα and EGF could stimulate NBLEC proliferation and DNA synthesis in dosage-dependent pattern. Combined use of either two factorsdid not increase the effect, and bFGF could increase cell migration and improve the activity of tissue plasminogen activator (t-PA). TNFα and IL-α inhibited NBLEC regeneration and DNA synthesis but TNFα improved the activity of t-PA. It could be concluded that growth factor and inflammatory factor had differentrole on regeneration of NBLEC, such as cell proliferation, migration and t-PA activity. bFGF was the main factor which improved the regenerationof lymphatic endothelial cell.
Basing on the experimental results, 48 nerve defects (with the length of 3-4 cm in 21 cases, 4.1-5cm in 25 cases and 6cm in 2 cases) were repaired clinically by using vaseularized nerve sheath canal with living Schwann s cells, 87.5 percent of them obtained good results. The advantages were: (1) The neural sheath had rich blood supply with resultant less scar from its healing; (2) The living Schwann s cells would secrete somatomedin to promote the reproduction of neural tissues; and (3) The useless neurofib...
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.
Schwanns cells were obtained from the distal end of the sciatic nerve following Wallerian degeneration of SD rats. These cells were cultured with the anteriorhorn neuron of spinal cord of 14dayold SD rat fetus. The two kinds of cells were separated by a slice. Through the microscope, the dendrites and the morphology changes at the 24th, 48th, 72th, and 96 th hour after culture were observed. It was demonstrated that the Schwanns cells played the role of maintaining the survival of neuron and promoting the growth of dendrites. It was said that the Schwanns cells could secrete neurotrophic factor which made the body enlarged and caused the dendrites enlonged to several times of the body.
OBJECTIVE To confirm membrane-guided tissue regeneration in the healing course of segmental bone defects and study the mechanism. METHODS Segmental, 1 cm osteoperiosteal defects were produced in both radii of 12 rabbits. One side was covered with hydroxyapatite/polylactic acid(HA/PLA) membrane encapsulated as a tube. The contralateral side served as an untreated control. Healing courses were detected by radiographic and histologic examinations. RESULTS All control sides showed nonunion, whereas there were consistent healing pattern in test sides. CONCLUSION Membrane technique can promote bone regeneration.
ObjectiveTo more comprehensive understanding the survival situation of donors after liver transplantation, which can be applied to clinical diagnosis and treatment. MethodsThe related literatures in recent years of living donor liver transplantation (LDLT) postoperative complications, quality of life, and liver regeneration were reviewed, and the donors postoperative survival situation were investigated. ResultsLDLT has become an option, It is safe and feasible for healthy adults to donate partial liver for LDLT. ConclusionsDonor postoperative survival situation is very important, and it affect the development of LDLT.To improve donors postoperative survival situation, we still need more efforts.
Objective To explore an effect of the artificial nerve graft wrapped in the pedicled greater omentum on the early revascularization and an effectof the increased blood supply to the artificial nerve graft on the nerve regeneration. Methods Seventy-five rabbits were randomized into 3 groups, in which there were 2 experimental groups where the rabbits were made to abridge respectively with the artificial nerve grafts wrapped in the pedicled greater omentum (Group A) and with the artificial nerve grafts only (Group B), and the control group where the rabbits were abridged with the autologous nerve (Group C).On the 3rd, 7th and 14th days after operation, the evans blue bound to albumin (EBA) was injected into the vessels in all the grafts to show their revascularization. Twelve weeks after operation the nerve regeneration was evaluated with theelectrophysiological and histological observations on the serial sections, and was evaluated also with the transmission electron microscope. Results The artificial nerve grafts wrapped in the pedicled greater omentum in Group A and the autologous nerve grafts in Group C showed a beginning of revascularization on the3rd day after operation, and the revascularization was increased on the 7th and14th days. Compared with Groups A and C, the artificial nerve grafts in Group Bshowed a delayed revascularization on the7th day after operation. At 12 weeks after operation, there were no significant differences in the motor never conduction velocity, density of the regenerated myelinated nerve fibers, myelin sheath thickness, and diameter between Group A and Group C(Pgt;0.05). However, both Group A and Group C were superior to Group B in the above variables, with significant differences(Plt;0.05). Conclusion Utilization of the pedicled greater omentum to wrapthe artificialnerve grafts can promote an early revascularization of the artificial nerve graft and an early nerve regeneration of the artificial nerve graft because of an enhanced blood supply to the nerve graft.
Objective To investigate the mode and influential factor of newbone formation following distraction osteogenesis in mandibular lengthening. Methods Corticotomy was performed on bilateral mandibles in twelve adult male goats. A custommade distractor was used to lengthen the mandible at a rate of 1mm/day for 10 days (total 10 mm elongation). Four goats were sampled respectivelyat 2, 4 and 8 weeks after completion of distraction. The lengthening mandibles were examined by roentgenography and histology. Results Newly formed callus was observed in the distraction gap after mandibular lengthening. The new bone exhibited intramembranous ossification generally, but cartilage islands could be found in the specimen that diastractor loosed. Conclusion The above findings indicate that the mode of new bone formation in mandibular lengthening following distraction osteogenesis appears to be intramembranous ossification and that endochondral ossification takes place in case distractor has loosened.