Objective Peri pheral nerve injury is a common cl inical disease, to study the effects of the physical therapy on the regeneration of the injured sciatic nerve, and provide a reference for cl inical treatment. Methods Sixty-four female adult Wistar rats (weighing 252-365 g) were chosen and randomly divided into 4 groups (n=16): group A, group B, groupC, and group D. The experimental model of sciatic nerve defect was establ ished by crushing the right sciatic nerve in groups B, C, and D; group A served as the control group without crushing. At 2 days after injury, no treatment was given in group B, electrical stimulation in group C, and combined physical therapies (decimeter and infrared ray) in group D. At 0, 7, 14, and 30 days after treatment, the sciatic nerve function index (SFI) and the motor nerve conduction velocity (MNCV) were measured, and morphological and transmission electron microscopy (TEM) examinations were done; at 30 days after treatment, the morphological evaluation analysis of axons was performed. Results At 0 and 7 days after treatment, the SFI values of groups B, C, and D were significantly higher than that of group A (P lt; 0.05); at 14 and 30 days after treatment, the SFI value of group D decreased significantly, no significant difference was observed between group D and group A (P gt; 0.05) at 30 days; whereas the SFI values of groups B and C decreased, showing significant difference when compared with the value of group A (P lt; 0.05). At 0, 7, and 14 days after treatment, the MNCV values of groups B, C, and D were significantly lower than that of group A (P lt; 0.05), and there were significantly differences between group B and groups C, D (P lt; 0.05); at 14 days, the MNCV value of group D was significantly higher than that of group C (P lt; 0.05); and at 30 days, the MNCV values of groups B and C were significantly lower than that of group A (P lt; 0.05), but there was no significant difference between group D and group A (P gt; 0.05). At 0 and 7 days, only collagen and l i pid were observed by TEM; at 14 and 30 days, many Schwann cells and perineurial cells in regeneration axon were observed in groups B, C, and D, especially in group D. Automated image analysis of axons showed that there was no significant difference in the number of myelinated nerve fibers, axon diameter, and myelin sheath thickness between group D and group A (P gt; 0.05), and the number of myelinated nerve fibers and axon diameter of group D were significantly higher than those of groups B and C (P lt; 0.05). Conclusion Physical therapy can improve the regeneration of the injured sciatic nerve of rats.
ObjectiveTo investigate the behavioral recovery of spinal cord injury (SCI) rats that received transplantation of NEP1-40 gene-modified neural stem cells. MethodsNeural stem cells (NSCs) were derived from the cortex tissue of rat embryo at the age of 18 days and identified by Nestin immunofluorescence. The lentiviruses were transduced to NSCs to construct NEP1-40 gene modified NSCs. Spinal cords of 30 Sprague-Dawley rats were hemisected at the nineth thoracic vertebrae level. The rats were randomly assigned to three groups. Cell culture medium, NSCs and NEP1-40 gene-modified NSCs were transplanted into the lesion site of rats of SCI group, NSCs group and NEP1-40-NSCs group respectively 7 days after injury. Additional 10 rats served as blank control group (sham group), which only received laminectomy. Following transplantation, behavior tests including Basso, Beattie, Bresnahan (BBB) Locomotor Rating Scale and grid test were utilized to evaluate spinal cord functional recovery. ResultsBehavior tests 8 weeks after cells transplantation showed that the rats in SCI group got worst results, the BBB scores improved and the grid drop times reduced significantly in NSCs transplantation group (P<0.01) and behavioral test outcomes were best in the NEP1-40 gene-modified NSCs group (P<0.01). ConclusionNEP1-40 gene modification can significantly improve the behavioral recovery of SCI rats that received transplantation of pure neural stem cells. It can provide a new idea and reliable experimental base for the study of NSCs transplantation for spinal cord injury.
ObjectiveTo explore the effect of exogenous ghrelin on early recovery of rats after subtotal gastrectomy. MethodsTwelve rats undergoing subtotal gastrectomy (B-Ⅰtype) were randomly divided into two groups, and saline or ghrelin was intraperitoneally injected in two groups, respectively. The body weight and daily food intake were measured before operation and on 1-7 d after operation. Rats were killed on day 7 after operation and the expressions of ghrelin mRNA in the fundus of stomach and anastomotic stoma was determined by realtime fluorescent quantitative PCR assay. The anastomotic bursting pressure and hydroxyproline content of anastomotic stoma tissues were also detected. ResultsThere was no significant difference (P＞0.05) in pre and postoperative body weight between two groups. Gradual decrease in postoperative body weight among the rats of saline group was observed which was significantly lower than that before operation (Plt;0.01). Body weight reached it’s lowest on day 1 after operation (Plt;0.01), after which it gradually increased but was still lower than that before operation (Plt;0.01). The postoperative body weight of rats in ghrelin group gradually decreased too, and was also significantly lower than preoperative body weight (Plt;0.01), except for the day 1 after operation (P=0.693). It reached the lowest on day 4 after operation (Plt;0.01), then it gradually increased but was still lower than that before operation (Plt;0.05 or Plt;0.01). The cumulative food intake of rats in ghrelin group was （52.50±6.77） g, which was significantly higher than that in saline group 〔(45.67±7.47) g〕, Plt;0.05. On day 7 after operation, relative expression of ghrelin mRNA in the fundus of stomach of rats in ghrelin group was 0.08±0.04, which was significantly lower than that in saline group (0.22±0.07), Plt;0.01. Compared with saline group, ghrelin-treated rats displayed significantly higher bursting pressure 〔（155.83±6.62） mm Hg vs. （172.33±10.44） mm Hg, Plt;0.05〕 higher hydroxyproline content 〔 (0.43±0.05) μg/mg wet tissue vs. （0.50±0.29） μg/mg wet tissue, Plt;0.01〕 at the anastomotic stoma. ConclusionGhrelin may effectively promote the early recovery of rats after subtotal gastrectomy.
Objective To explore the effects of several immunosuppressants on the cell numbers of cultured rat macrophages and Schwann’s cells. Methods The macrophages and Schwann’s cells were cultured from the newborn Wistar rats. Different concentrations of methylprednisolone(10-3, 10－4,10－6 and 10－8 mol/L), CsA(10－5, 10－6, 10－7 and 10－8 mol/L) and FK506(10-6, 10－7, 10－8 and 10－9 mol/L) were administrated to the cells, while control group was given no drugs. Twentyfour, 48 and 72 hours after administration, the cells from different concentrations were measured with MTT methods respectively. Theresults were compared and analyzed statistically. Results Only high concentration methylprednisolone (10-4 mol/L) and a certain range of concentrations of CsA (10-6，10-7 and 10-8 mol/L) and FK506 (10-7,10-8 and 10-9 mol/L) can provide protection to culturedrat macrophages. Under most concentrations, CsA and FK506 had no effects onthe cell number of cultured rat Schwann’s cell. Only with high concentration CsA (10-5 mol/L) and methylprednisolone (10-3 mol/L) could significantly decreased the cell number of Schwann’s cell. Long time (72 hours) and low dosage (10-8 mol/L) administration of methylprednisolone could significantlyprotect Schwann’s cell. Conclusion High concentration methylprednisolone and some certain concentration CsA and FK506 can protect cultured rat macrophages. But high concentration CsA and methylprednisolone prohibit the proliferation of Schwann’s cells. Only long time and low dosage methylprednisolonecan protect cultured rat Schwann’s cells.
【Abstract】 Objective To investigate the effectiveness of all-trans-retinoic acid (ATRA) at different concentrationson prol iferation and differentiation of the rat embryonic neural stem cells (NSCs), and to find the optimal concentration of ATRA that promoting the differentiation of NSCs into neurons. Methods NSCs were isolated from cerebral cortex of rat embryos (embryonic day 12-16, average 15 days), and were cultured in serum-free medium (DMEM/F12 medium containing 20 ng/mL bFGF and 20 ng/mL EGF) at the concentration of 1×106 cells/mL. Subcultures were performed 7 days after the primary culture. The cell clusters of the 3rd passage were centrifuged and divided into 5 groups. In the experimental groups (groups A, B, C, D), the ATRA concentration was 0.5, 1.0, 5.0, 10.0 μmol/L in DMEM/F12 complete medium respectively, while in control group (group E), the ATRA concentration was 0 in DMEM/F12 complete medium. The prol iferation rate of each group was analyzedby cell counting day by day till 7th day, and BrdU positive cell counting 1, 3, 5, 7, 9 days after culture. In addition, collecting the 3rd passage NSCs and divided into 5 groups. In the experimental groups (groups A, B, C, D), the ATRA concentration was 0.5, 1.0, 5.0, 10.0 μmol/L in DMEM/F12 medium containing 5% FBS respectively, while in control group (group E), the ATRA concentration was 0 in DMEM/F12 medium containing 5% FBS. The capacity of NSCs differentiation toward neurons was determined by immunofluorescence double-labell ing and flow cytometry. Results Cell counting 1-7 days after culture in each experimental group (groups A, B, C, D) showed no significant differences (P gt; 0.05). Cell counting at each time point of all the experimental groups were less than those of control group (P lt; 0.05). BrdU positive cells were increased 1, 3, 5, 7, 9 days after culture in each experimental group (groups A, B, C, D), but there was no significant difference between each experimental group(P gt; 0.05). BrdU positive cells at each time point of control groups were more than those of all the experimental groups (P lt;0.05). The differentiation ratio of neurons was enhanced in experimental groups and the optimal ATRA treatment concentration was 1.0 μmol/ L (experimental group B). The differentiation ratio of neurons induced by ATRA in group B was 29.46% ± 0.47%, 47.25% ± 0.46% and 66.81% ± 0.57% respectively after cultured 3, 5 and 7 days, whereas the differentiation ratio of neurons was 11.11% ± 0.59%, 14.10% ± 0.32% and 15.92% ± 0.70% respectively in control group. The majority of NSCs differentiated into astrogl ial phenotypes in control group. By flow cytometry detection, the differentiation ratio of neurons after cultured 3 days and 7 days in experimental groups were more than those in control group (P lt; 0.05). Conclusion ATRA treatment remarkably promoted the differentiation of NSCs into neurons and the optimal concentration was 1.0 μmol/L.
Objective To investigate the pathological characteristics of hepatic energy metabolism changes following hepatic inflow occlusion and the tolerant limit to ischemia in cholestatic rats.Methods On the day 7 after rats biliary obstruction, the survival rate, hepatic mitochondrial respiratory function, content of ATP, and the ketone body ratio in arterial blood were investigated following the different duration of hepatic ischemia and reperfusion with portal blood bypass.Results The survival rate on postoperative day 10 was 100%, 100% and 40% subjected to 30, 60 and 90min of hepatic vascular occlusion. The hepatic energy metabolic function was decreased markedly following ischemia, and was increased markedly on 24 hours following reperfusion subjected to 30, 60min of hepatic vascular occlusion, but it had less increase with 90min of hepatic vascular occlusion.Conclusion The hepatic energy metabolic function injury is reversible in cholestatic rats, and the rats can tolerate hepatic inflow occlusion within 60min, but the hepatic energy metabolic function injury is irreversible after 90min of hepatic occlusion.
Objective To study the relationship between the expression ratio of induced nitric oxide synthase (iNOS) over glial fibrillary acidic protein (GFAP) and the time of injury after brain concussion in rat, in order to acquire a new visual angle for determining injury time of cerebral concussion. Methods Eighty-five healthy Sprague-Dawley rats were divided into three groups randomly: model group (n=25), experimental group (n=55), and control group (n=5). The rats in the model group were used to confirm the attack hight to make the model of brain concussion; according to the time of execution, rats in the experimental group were then subdivided into 11 groups with 5 rats in each subgroup, and their execution time was respectively hour 0.5, 1, 3, 6, 12, 24, 48, 96, 168, 240, and 336; the rats in the control group were executed after fed for 24 hours. After the model of cerebral concussion was established through freefalling dart method, hematoxylin-eosin staining and immunohistochemistry staining of iNOS and GFAP were conducted for the brain of the rats. All related experimental results were studied by using microscope with image analytical system and homologous statistics. Results The ratio of positive expression of iNOS over that of GFAP increased gradually during hour 0.5- 3 after injury in brain (from 5.03 to 10.47). At the same time, the positive expression of iNOS increased significantly (from 14.61% to 37.45%). However, the increase of the positive expression of GFAP was not obvious. Between hour 3 and 12, the ratio began to decline to 4.98, which was still at a high level, and during the same time period, the positive expressions of iNOS and GFAP also experienced the same change pattern. Later, the ratio began to decline between hour 12 and 336 after injury (from 4.98 to 0.95). All ratios at this time were lower than those between hour 0.5 and 12. The positive expression of iNOS and GFAP both increased to a climax before declining. Conclusions The ratio of positive expression of iNOS over GFAP and the respective change pattern of iNOS and GFAP can be used as the evidence of estimating the injury time of cerebral concussion. We can use the ratio of two or more markers to provide a new visual angle for concluding the concussion injury time.
【Abstract】ObjectiveTo investigate the effects of liver transplantation on splenic function in rats with hepatic cirrhosis. MethodsHepatic cirrhosis model was established in rats by subcutaneous injections of carbon tetrachloride. Liver transplantation model was established with twocuff technique. Spleen index, morphological changes of spleen were observed before and after liver transplantation in hepatic cirrhosis rats. Spleen T lymphocyte subgroups before and after liver transplantation were also assayed by immunofluorescence staining and flow cytometry. ResultsBefore liver transplantation, spleen index was increased from (2.42±0.11) mg/g to (3.62±0.14) mg/g， P＜0.01; pathological examination of spleen samples showed that the areas of white pulp were decreased from (23.47±2.30)% to (7.70±2.01)%， P＜0.01， and the areas of spleen trabecula were increased from (1.75±0.61)% to (4.46±0.71)%， P＜0.01. Meanwhile, the ratio of CD4/CD8 of spleen T lymphocyte subgroups was decreased from 2.67±0.15 to 1.18±0.15, P＜0.01. After liver transplantation, spleen index was decreased from (3.62±0.14) mg/g to (2.62±0.11) mg/g， P＜0.01; pathological examination of spleen showed that the areas of white pulp were increased from (7.70±2.01)% to (15.07±1.97)%， P＜0.01, and those of spleen trabecula were decreased from (4.46±0.71)% to (3.11±0.51)%， P＜0.05. Meanwhile, the ratio of CD4/CD8 of spleen T lymphocyte subgroups was increased from 1.18±0.15 to 2.32±0.11, P＜0.01. ConclusionImpaired function of spleen resulting from liver function damage can be improved in rats with hepatic cirrhosis after liver transplantation.
Objective To investigate the therapeutic effects of transplanting allogeneic marrow mesenchymal stem cells (MSCs) via subarachnoid space on spinal cord injury(SCI) and the T cell subpopulation. Methods Density gradient centrifugation was used to isolate and expand MSCs from bone marrow of 10 six-week-old SD rats. The SCI model was produced by weightbeating from 60 eight-week-old female SD rats. Forty survival SCI rats,which BBB scores were zero, were divided randomly into 2 groups:experimental group(group A) and control group(group B). In addition, 20 normal eightweekold SD ratswere used as blank group (group C). In group A, 1 ml cells suspention containing MSCs(the 6th generation, 2×106/ml) was injected via subarachnoid space. Ingroup B, equal volume of L-DMEM was injected in the same way. The BBB score was obtained after 1st,2nd and 3rd weeks of injection. At the same time,T cell subpopulation was detected by flow cytometry. Results The BBB score in group A was better than that in group B, but fewer than that in group C in the 3rd week. CD4+T cells in group A were less than those in groups B and C in the 1st, 2nd, and 3rd weeks. CD8+T cells in group A were less than those in groups B and C in the 2nd and 3rd weeks. The ratio of CD4+/CD8+T cells in group A was less than those in groups B and C in the 1st week. Above differences showed statistically significant difference(P＜0.05). However, there were no statistically significant differences in the ratio of CD4+/CD8+T cells between group A and groups B, C in the 2nd and 3rd weeks (P＞0.05). Conclusion The above results suggest that allogeneic MSCs transplantation via subarachnoid space is beneficial to SCI to some extend, do not result in rejection in vivo. Furthermore, it can lead to immunosuppression in short time. So, it provides clues to apply MSCs to treat SCI and other diseases.