Objective To introduce the current development of periodontal regeneration. Methods The recent l iterature about advances in the regeneration of periodontium using tissue engineering was extensively reviewed and new technologies that will lead to further advances in periodontal therapy was investigated. Results The cells, appropriate signals,scaffold and blood supply play fundamental roles in periodontal regeneration. Furthermore, interreaction of these factors, such as cells modified by growth factor gene or growth factor del ivered by scaffold, will enhance their effects in tissue regeneration. Conclusion Periodontal tissue engineering have great potential and promising future in periodontal regeneration and therapy.
Objective To explore the liver regeneration following partial liver transplantation. MethodsPartial liver transplantation in the rats were established, three experimental groups were: Ⅰ=control, partial liver resection; Ⅱ=orthotopic liver transplantation (OLT); Ⅲ=partial orthotopic liver transplantation (POLT). Liver function test, morphological investigations and liver regeneration were performed in different time after transplantation. The regenerative response of transplanted partial liver graft in rats were evaluated by Flow Cytometry and compared it to liver regeneration following resection.Results The serum concentrations of ALT, BILI increased in one week, but returned gradually to normal level within one month after transplantation. Large numbers of mononuclear cells infiltrating into the portal areas. Hepatocyte necrosis was observed on day 14 after transplantation. On day 30, the parenchyma cell showed a nearly normal appearance, bile duct proliferation was seen in portal areas. In addition, after liver resection and POLT some diploid hepatocytes were found. Dilation of the central veins, adjoining sinusoids and interlobar veins were seen in group Ⅲ. The partial liver graft is capable of regeneration similar to the situation following partial hepatectomy. The peak of liver regeneration was seen on day 1,2,4 following a hepatectomy and POLT and OLT, respectively.Conclusion The transplanted liver shows the same and/or enhanced regeneration compared to controls. There are several possible explanations for the slight delay in achieving the maximal regenerative response in rats undergoing the POLT and OLT. These may include damage that is induced by the operation itself, preservation, and reperfusion injuries. These suggest that this be caused by activation of the immune system and it might be related to the regulation of cytokines and hormone.
The model of the denervated lateral head of gastrocnemius musde was adopted in this experiment on 50 rabbits. At random, the denervated muscle on oneside received the soleus muscle bundles with neurovascular pediele implantation (MBNPI). While the other side received the direct soleus nerve implantation (DNI). Eighteen weeks later after the two types of implantations the electromyography, force of muscles, histochmical findings and the electronic microscopic examination of the dernervated muscles of the two...
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...
Abstract: The amniotic fluidderived stem cells (AFSC) possess considerable advantageous characteristics including high proliferation potential, easy availability, low immunogenicity and oncogenicity，and accordance with medical ethnics. Moreover, they do not require the sacrifice of human embryos for their isolation and the cells can differentiate into all three kinds of germs. Accordingly，they initiate a new and very promising field in stem cell research and they will be a potential source of stem cells for therapies related to regeneration medicine of cardiovascular diseases. The research about the AFSC utilization in cardiovascular diseases is just started. Though there were some exciting breakthroughs, there still remain many challenges. In the article，we will discuss AFSC characteristics, influence of amniotic fluid harvesting time on stem cells, isolation and purification, emphasizing mainly on the potential of AFSC differentiation into cardiovascular cells, current situation and problems in this field.
Objective To introduce the cells and cell-transplantation methods for periodontal tissue engineering. Methods Recent l iterature about appl ication of cell-based therapy in periodontal tissue engineering was extensively reviewed, the cells and cell-transplantation methods were investigated. Results Mesenchymal stem cells were important cell resourcesfor periodontal tissue engineering, among which peridontal l igament stem cells were preferred. Bone marrow mesenchymal stem cells had several disadvantages in cl inical appl ication, and adipose-derived stem cells might be a promising alternative; different transplantation methods could all promote periodontal regeneration to some extent. Single-cell suspension injection could only promote a l ittle gingival regeneration, and tissue engineered scaffolds still needed some improvement to be used in periodontal regeneration, while cell sheet technique, with great cell loading abil ity and no need of scaffolds, could promote regeneration of cementum, periodontal l igament, and alveolar bone under different conditions. Conclusion Multipotent stem cells are fit to be used in periodontal tissue engineering; improvement of cell-transplantation methods will further promote periodontal regeneration.
OBJECTIVE: To provide experimental basis for improving the curative effect of pectus excavatum. METHODS: Twelve rabbits were adopted in this experiment. After the bilateral second and third costal cartilages of the rabbits were resected subperichondrially, their right second and third costal perichondriums were damaged intentionally. Then, the bilateral third costal perichondriums were stitched into a tube-like structure and the second ones were left opened. After 2, 4, 6 of operation, the bilateral second and third neocartilages were measured for their width, and histological character were observed under microscope. RESULTS: 1. After 2, 4, 6 months of operation, the average width of the bilateral second neocartilages were significantly greater than the preoperative ones. 2. 4 and 6 months after operations, there was no significant difference in the average width of the bilateral third neocartilages and the preoperative ones. 3. The amount, distribution of costal neocartilage cells and the arrangement of costal neocartilage matrix within the left second and third costal cartilages were better than the right under the light microscope. 4. The left third costal neocartilage was regenerated and remodeled better than all the others. CONCLUSION: The integrality of costal perichondrium is in favor of the regeneration of costal cartilage, and the sleeve stitch of costal perichondrium facilitates the remodeling of costal neocartilage.
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.
Objective To explore effects of several immunosuppressants on cytokine expressions after repair for a sciatic nerve injury in a rat model. Methods The sciatic nerves of 42 rats were cut and suturedend to end. After operation, the rats were divided into 6 groups. Group A(n=9) was served as a control with no medicines given. Group B (n=9) was given methylprednisolone 20 mg/(kg·d) for 2 days. Groups C(n=9) and D(n=3) were given FK506 1 mg/(kg·d) for 2 weeks and 4 weeks respectively, and were given the same doses of methylprednisolone as Group B. Groups E and F were given CsA 2 mg/(kg·d) for 2 weeks and 4 weeks respectively, and were given the same doses of methylprednisolone as Group B. The sciaticnerves were sampled at 1, 2 and 4 weeks postoperatively. And immuneohistochemistry stainings of interleukin 1β(IL-1β)， tumor necrosis factor α(TNF-α), interferon γ(IFN-γ) and macrophage migration inhibitory factor(MIF) were performed. The staining results were compared and analyzed. Results The expression peaks of IL-1β and IFN-γ were found at the 1st week postoperatively in Group A. Then, the expression decreased rapidly at the 2nd week and disappeared at the 4th week. As for TNF-α and MIF, they were only found to have a low expression until the 1st week in Group A. In groups C-F, the expression peaks of IL-1β, TNF-α and IFN-γ were found at the 2nd week, while the expression peak of MIF was still at the 1st week, and the expression of all the cytokines extended to the 4th week. The expressions of these cytokines in Group B were just between the expression levels of Group A and Groups C-F. Conclusion Immunosuppressants can delay the expression peaks and significantly extend the expression time of IL-1β, TNF-α, IFN-γ and MIF after repair for a sciatic nerve injury in a rat model.
OBJECTIVE: To study the feasibility of α-cyanoacrylate medical adhesive in fixation of intratemporal facial nerve when nerve was repaired within chitin chamber, and to investigate the nerve regeneration. METHODS: Nerve defect of 6 mm was made in left intratemporal facial nerves of 48 rabbits. All the defects were bridged with chitin chamber and were fixed by α-cyanoacrylate medical adhesive, surgical suture and natural union. Nerve function test and histomorphological examination were carried out at 1 month and 3 months after repair. RESULTS: It was observed that the nerve was fixed firmly to the chamber with no crack or crease by α-cyanoacrylate medical adhesive. The regenerated new nerve fibers were more regular and denser and the neurological function recovered much better in the group fixed by alpha-cyanoacrylate medical adhesive than in the groups those fixed by surgical suture and natural union. CONCLUSION: The medical adhesive is b in adhesion and beneficial to nerve repair; repair of intratemporal facial nerve defect within chitin chamber fixed by alpha-cyanoacrylate medical adhesive is feasible, simple and timesaving.