ObjectiveTo develop and modify a rat model of partial liver transplantation with hepatic arterialization and to investigate the postoperative histopathologic changes of the grafts. MethodsModified twocuff technique was applied to establish a rat model of partial liver transplantation, and the donor’s celiac artery was anastomosed with the recipient’s right renal artery. The biopsy of the grafts was performed on the day 1,2,4 and 7 after transplantation. Results85.4% of the recipients had survived for one week.Nuclear mitoses were seen on the postoperative day 2 by microscopy, while on the day 4 they were found occasionally. Two nucleus cells were seen on the day 4 and 7. Conclusion The stability of the model is improved by modifying the technique. Liver acupuncture biopsy is a simple, safe and feasible way to be applied in the research of postoperative problems of liver transplantation. Reconstruction of hepatic artery is possible to enhance the regeneration of liver grafts.
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.
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 review the researches of donor nerve’s promoting effect on regeneration of reci pient nerve in end-to-side neurorrhaphy at home and abroad. Methods The latest original l iterature concerning donor nerve’s accelerating effect on regeneration of recipient nerve was extensively reviewed. Results Proper nerve cutting may promote nerve regeneration. But how to quantize the cutting volumn was still a challenge. Conclusion It is important to research thedonor nerve in neurorrhaphy, which can provide evidence for cl inical neurorrhaphy so as to achieve good results.
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 elucidate the new concept and theory of neurorestoratology. Methods With the review of the development course and important research works in the field of neurorestoratology during the 20th century, especially recent 30 years, the regularity summary, science and technology philosophy induction, and theory distillation were carried out in this article. Results The new discipl ine system was brought forward as follows: ① Definition: neurorestoratology was asub-discipl ine of neuroscience which studies neural regeneration, neural structural repair of replacement, eruroplasticity and neuromodulation. The core purpose was to promote neural functional recovery of all neural degenerative diseases and damages. ② One central task and two basic points: to recover neurological function was the central research task all the time and the two basic points were the precl inical (basic) neurorestoration and the cl inical neurorestoration. ③ Four rationale of the discipl ine: l imited renovation, relearning, insufficient reserve, and l ifelong reinforcement. ④ Five major factors of neurorestoratology (5N’s dogma): neuroregeneration, neurorepair, neuroplasticity, neuromodulation, neurorehabil itation. “Neuroprotection” appeared to be included in the broad definition. ⑤ Four-step rule of neurorestoratology: structural neurorestoration, signal neurorestoration, rehabil itative neurorestoration, and functional neurorestoration. ⑥ Emphasize that translational medicine from lab to bed in neurorestoration. Conclusion The discipl ine of neurorestoratology has the vast development prospectand will be sure to increase the rapid progress of the basic and cl inical restorative neuroscience.
Objective To investigate the velvet antler polypeptide (VAP) on sciatic nerve regeneration in rats through local administration and VAP-PLGA compound membrane. Methods The 3, 15 mg/g of VAP-PLGA compound membranewere prepared by compounding VAP and PLGA, respectively. Seventy-two Wistar rats, male or female, aged 3-6 months and weighing (250 ± 50) g, were selected to make the model of sciatic nerve section. Then, all rats were randomized into 4 groups (n=18): group A in which nothing was given after anatomosis, group B in which 1 mL of VAP at the concentration of 10 mg/L was injected into the gastrocnemius muscle medial for every other day, group C in which 3 mg/g of VAP-PLGA compound membrane was given to the nerve anastomotic stoma and group D in which 15 mg/g of VAP-PLGA compound membrane was given to the nerve anastomotic stoma. The sciatic adhesion degree observation, electrophysiological examination, immunohistochemical staining and hemi-quantity calculation and horseradish peroxidase (HRP) retrograde tracing were conducted 2, 4 and 6 weeks after operation, respectively. Results All rats survived to the end of the experiment, without foot ulcer or neuroma. Severer nervous adherence was observed in group A, mild adherence in group B, and no adherence in groups C and D 2, 4 and 6 weeks after operation, respectively. The recovery rate of the evoked potential of triceps surae in groups B, C and D was better than that in group A (P lt; 0.01), group D was superior to groups B and C (P lt; 0.05) at each time point. No significant difference between group B and group C (P gt; 0.05) 2, 4 weeks after operation was detected, but group C was superior to group B (P lt; 0.05) 6 weeksafter operation. For the regenerative fiber axon and the expression of myelin sheath TGF-β1 and IGF antigen, the staining intensity in groups B, C and D was higher than that in group A at each time point (P lt; 0.05), and there were significant differences between group D and groups B and C 6 weeks after operation (P lt; 0.05), but no difference between groups B and C (P gt; 0.05). The HRP retrograde tracing showed that the myelinated nerve fiber stained by HRP gradually increased as time passed by and myelinated nerve fiber stained by HRP in groups B, C and D was much more than that in group A, and group D was superior to the other groups. No significant difference between group B and group C was detected. Conclusion To apply VAP through either local administration or VAP-PLGA compound membrane around the attached site of nerve anastomosis is capable of promoting nerve regeneration, which has an obvious dose-effect relationship with the dose of VAP. Meanwhile, VAP-PLGA compound membrane can prevent the nerve adhesion.
Objective To review researches of the role of inhibitorof differentiation 2(Id2) in skeletal muscle regeneration. Methods The latest original literature concerning Id2 and its role in skeletal muscle regeneration was extensively reviewed. Results Id2 could form heterodimers by combining with E protein to prevent myogenic regulatory factors (MRFs) forming heterodimers by combining with E protein, to inhibit the transcription activity of MRFs anddifferentiation of skeletal muscle cell. Conclusion Id2 plays an important role in skeletal muscle regeneration.
Objective To investigate the outcome of repairing the peripheral nerve defects with the tissue engineered nerve constructed by Schwann cells and fibrin glue. Methods Wallerian degenerated sciatic nerve were harvested from the 4-week-old New Zealand rabbits for culture of Schwann cells. The Schwann cells were then separated, amplified and purified, and then were identified by the S-100 protein immunochemical staining. The cultured Schwann cells (1×106/ml) were mixed with fibrin glue to form the Schwann cell-fibrin glue compound, which was observed by the inverted phase contrastmicroscope. The compound filled some silicone tubes (Group A) and biomembrane (Group B) to fabricate the tissue engineered nerves with a purpose of repairing the 10-mm defects in the New Zealand rabbit tibia nerves. The autologous nerve grafting was performed in Group C. The electrophysiological examination and the histomorphological analysis were performed at 10 weeks after the transplantation. Results All the rabbits survived through the experiment. In Group A, all the rabbits developed an ulcer in the soles of their left feet at 3-4weeks after the transplantation, while less ulceration developed in Groups B and C. At 10 weeks after the transplantation, the electrophysiological examination was performed, the elective stimulation failed to pass through the nerve grafts, and no composed muscular action potential was found in all the rabbits in Group A; the elective stimulation could pass through all the nerve grafts in Groups B and C, and could evoke the composed muscular action potential; the composed muscular action potential and the nerve conduct velocity in the two groups were 4.21±0.82 mV and 3.40±5.40 m/s vs. 4.80±1.15 mV and 36.55±6.43 m/s(Pgt;0.05). In Group A, no regrown axon was found in the nerve grafts, but neuromawas found to have formed in the both ends of the silicon tube. In Groups B and C, there was no obvious neuroma formation but regrown axons could be found to have regenerated. The histomorphological analysis on the regrown axons showed thatthere was no statistically significant difference between Groups B and C. Conclusion The tissue engineered nerve fabricated with Schwann cells, fibrin glue, and biomembrane can promote the nerve regeneration, and its reparative effect is similar to that of the autologous nerves; therefore, the future of its clinical practice is brilliant.