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 effect of subcutaneous implant of peripheral nerve allograft on sciatic nerve regeneration in rats. METHODS: Out of 30 male Wistar rats, 6 were donors and 24 were divided randomly into 2 groups. In experimental group (group A, n = 12), a 15 mm segment of sciatic nerve harvested from donors was separately inserted into subcutaneous compartment on the right thigh; two weeks later, the segment of sciatic nerve in subcutaneous compartment was removed and transplanted into a 10 mm sciatic nerve defect of left, which was made immediately. In the control group (group B, n = 12), a 10 mm sciatic nerve defect was made and immediately repaired in situ on the left thigh. The regeneration of sciatic nerve was examined histologically (after 2, 4, 8, and 14 weeks) and electrophysiologically (after 14 weeks of operation). RESULTS: After 2 weeks of operation, the inflammatory reaction was a little ber in group A than in group B. After 4 weeks, the intensity of the inflammatory reaction was similar between two groups; some collagen fibers proliferated. After 8 weeks, the inflammatory reaction ended and the collagen fibers proliferated obviously. After 14 weeks of operation, the structure of epineurium was in integrity and there was no obvious difference in perineurium and endonurium between two groups. A large number of myelinated nerve fibers and a small number of unmyelinated nerve fibers regenerated. The structure of myelin sheath was in integrity. The number and size of regenerated axon had no significant difference between two groups(P gt; 0.05). The conduction velocity, the peak value and the latent period of motor nerve were no significant difference between two groups (P gt; 0.05). CONCLUSION: The allograft of sciatic nerve inserted into subcutaneous compartment can promote nerve regeneration.
Objective To study the effects of the periosteum，synovium andcartilage tissues on the gene expressions of proteoglycan, collagen Ⅱ, andnuclear factor kappa B (NF-κB) and to investigate the different effects of these tissues on cartilage regeneration. Methods In 20 New Zealand white rabbits, 20 cartilage explants were taken from the knee joints in each rabbit, the sizeof which was 4 mm×4 mm×4 mm. All the cartilages were divided into the following 4 groups and cultured for 7 days: Group A, with 5 pieces (2 mm×2 mm) of the synovium of theknee joints in each dish; Group B, with 5 pieces (2 mm×2 mm) of the periosteum ineach dish; Group C, with 5 pieces (2 mm×2 mm×2 mm) of the cartilage in each dish; and Group D, with no addition of other tissues (control group). RNA was extracted from the cells of the cartilage explants (4 mm×4 mm×4 mm) in all the dishes. Thegene expressions of proteoglycan, collagen Ⅱ and NF-κB were defected by a reversetranscription-polymerase chain reaction (RT-PCR).Results In group A, the gene expression of proteoglycan was significantly decreased. The relative density of this gene expression had a significant difference when compared with that in group D (1.09±0.21 vs. 1.25±0.25, Plt;0.05); the gene expressions of collagen Ⅱ and NF-κB were also decreased, but they had no significant differences when compared with those in group D (Pgt;0.05). In groupB, the gene expressions of proteoglycan, collagen Ⅱ, and NF-κB were significantly increased. The relative densities of these gene expressions were 1.60±0.26, 1.57±0.24, and 4.20±2.22, respectively, which had significant differences when compared with those in group D (Plt;0.05). In group C, the relative density of the gene expression of collagen Ⅱ was 1.43±0.28, which had a significant difference when compared with that in group D (Plt;0.05), but therelative densities of the gene expressions of proteoglycan and NF-κB had no significant differences when compared with those in group D (Pgt;0.05). Conclusion The results indicate that the periosteum can up-regulate the gene expressions of proteoglycan, collagen Ⅱ and NF-κB. The NF-κB is likely to be an important nuclear transcription factor related to cartilage regeneration. The results also suggest that the periosteum maybe better in facilitating the cartilage repair and regeneration in clinical practice.
Objective To discuss peripheral nerve regeneration under immunosuppression. Methods Current research trends about relationship between peripheral nerve injury and immunoreaction, the experimental result of nerve regeneration after using various immunosuppressors, and the clinical findings after human allogenous hand transplantation were extensively reviewed. Results Peripheral nerve regeneration was accelerated under immunosuppression. Conclusion Peripheral nerve injury may induce immunoreaction, which inhibit nerve regeneration and function recovery.
OBJECTIVE: To review the role of thyroid hormone in the peripheral nerve regeneration. METHODS: The recent literatures of experimental study and clinical application on the role of thyroid hormone in nerve regeneration were reviewed. The researches on expression, isoform and changes of thyroid hormones in rat sciatic nerve in normal or injury were summarized. The effect of thyroid hormone on local rat sciatic nerve was studied, too. RESULTS: Nuclear thyroid hormone receptors expressed in numerous nuclei of sciatic nerve during a limited period of development extending from the third week of embryonic life to the end of the second postnatal week and after injury of adult sciatic nerve. A single and local administration of thyroid hormone at the level of the transected sciatic nerve produced a lasting effect on peripheral nerve regeneration. CONCLUSION: The beneficial effects of thyroid hormones upon injured peripheral nerve may have considerable therapeutic potential.
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.
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...
The capacity for self-regeneration of the adult heart is very limited, conventional therapies cannot solve the loss of cardiomyocytes in the infarcted heart leads to continuous ventricular remodeling. Cell transplantation therapy is emerging as a novel approach for myocardial repair over conventional therapies. Various types of cell transplantation have improved cardiac function and angiogenesis in animal models and clinical settings. The safety and feasibility of some clinical trials have been initiated. In this review, we summarize the advantages and limitations of different cell types proposed for cell transplantation in myocardial infarction and give an overview of the clinical trials using this novel therapeutic approach in patients with myocardial infarction.
OBJECTIVE: To validate the hemostatic properties of collagen sponge made in China. METHODS: The experimental model of superficial cut of liver was established in 20 Sprague-Dawley adult rats, which were divided into two groups randomly. Collagen sponge or gelatin sponge was used to cover the cut respectively. Hemostatic result was observed. Afterwards, standard liver trauma model by resection left front liver lobe was made, wound was treated with collagen sponge or gelatin sponge respectively. Hemostatic result was observed. Concurrent hemostatic time and bleeding amount were noted. At 7, 14 and 20 days after operation, intra-abdominal adhension, infection and healing state of liver were observed by exploratory laparotomy. The histological changes of regenerate liver tissue were observed by microscopy. RESULTS: Collagen sponge adhered to wound well. Concurrent hemostatic time and bleeding amount in collagen sponge group were superior to those of gelatin sponge (P lt; 0.05). The histological examination showed that collagen sponge was absorbed and degraded rapidly, regenerative hepatocytes could be induced. CONCLUSION: Collagen sponge has fine hemostatic properties and can induce regeneration of hepatocytes effectively. It is worth popularizing for its convenience in clinical application and its properties of rapid degradation and absorption.
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.
