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Objective: To explore the influence of plateau environment in the development and morphology of the main organs of the offsprings of migrated rats, and to observe the pathological changes of heart, brain, and lung tissues of the offsprings of migrated rats. Methods: The 8-week Wistar rats who lived in the plain area were migrated to the plateau area. After 1 week, a total of 56 female and male rats were fertilized with a ratio of 3:1, and all the pregnant rats were natural childbirth. The offsprings rat pups were divided into three groups: 1 month, 3 months, and 6 months. Ten offsprings (5 female and 5 male) were randomly selected in each group to collect the heart, brain, lung, liver, kidney and other major organs to measure the weights. In each group, 45 offsprings were randomly selected to conduct water maze test, open field test and test of captive reaction. The brain, heart, and lung tissues from 5 offsprings in each group were collected for tissue section and the pathological changes of above organ tissues were detected with HE staining. Results: The pregnant rats moved from the plain to the plateau had normal feeding behavior, without preterm birth or death. On average, the pregnant rats had 8 to 10 babies per litter, with a total of 345 offsprings. The weight gain of offspring was about 1. 0-1. 5 g per day. Some of the offsprings had low intake and difficulty in foraging, and 15 offsprings died 3-5 d after birth, with a mortality rate of 4. 3%. The weight and the ratio of liver weight to body weight of the 6-month-old offsprings were increased compared with the 1-month-old offsprings (F0. 05). In open field test, there were 6 offsprings in open fieled test in 1-month old group showed a longer stay time in the central region than other rats (P0. 05). In spite of all the time points in the captive reaction experiment, all the animals behaved in a similar way. The HE staining results of myocardium tissue showed the myocardial inflammatory cell infiltration, venous congestion, nucleus disappearance, and visible cellular outline in the 1-3 month old offsprings and the myocardial vascular congestion and myocardial space enlargement in the 6-month-old offsprings. The HE staining results of brain tissue showed the glass body formation and nucleus disappearance in the 1-month-old offsprings and neuronal cell body deformation, blood vessel congestion and vacuolar degeneration in the 3-6-month-old offsprings. The HE staining results of lung tissue showed the thicker alveolar walls, lymphocyte and plasma cell infiltration, pulmonary capillary expansion and congestion in the 1-3-month-old offsprings and the thicker alveolar walls, lymphocyte and plasma cell infiltration, pulmonary capillary expansion and congestion, pulmonary interstitial edema and red blood cell liquefaction in the blood vessels in the 6-month-old offsprings. Conclusion: Tibetan plateau environment has an influence in the development and morphology of heart, brain and lung of the migrated rats, and the reason may be related to low pressure and hypoxia of plateau.
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BACKGROUND: Studies are very few regarding the specific reaction of bone marrow mesenchymal stem cells (BMSCs) to activated microglia. Moreover, it remains unclear how MSCs maintain dopaminergic neuronal survival under specific microenvironment.OBJECTIVE: To explore the effect of BMSCs stimulated by activated microglia on dopaminergic neuron survival.METHODS: BMSCs were isolated from Wistar rats by attachment method, and in vitro cultured; microglia was activated, and dopaminergic neurons were cultured by enzyme digestion method. The experiment included 5 groups: BMSCs, microglia, lipopolysaccharide (LPS)+microglia; BMSCs+LPS+microglia groups, in which the dopaminergic neurons were cultured with corresponding culture medium; the dopaminergic neurons alone group was cultured with 10% fetal bovine serum+ DMEM/F12. The effect of different microenvironment on dopaminergic neuron survival and gliocyte-derived neurotrophic factor released from BMSCs were detected by immunofluorescence technique.RESULTS AND CONCLUSION: The release of gliocyte-derived neurotrophic factor in groups involving BMSCs was greater than corresponding control group. Tyrosine hydroxylase immunofluorescence showed that neuronal survival of dopaminergic neurons alone group was 15%, microglia group was 10%, LPS+microglia was 5%, but BMSCs+LPS+microglia group was 28%, significantly greater than the other groups (P < 0.05). In addition, survival of in vitro cultured dopaminergic neurons was decreased with increasing culture duration, but the survival of dopaminergic neurons in group involving BMSCs was significantly greater than corresponding control group. This indicates that microglia activation stimulated BMSCs to upregulate gliocyte-derived neurotrophic factor to prevent dopaminergic neurons from toxic injury, and inhibit delayed death of dopaminergic neurons.
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BACKGROUND: Bone marrow mesenchymal stem cells (BMSCs) are conveniently cultured and separated in vitro because theirimmunogenicity is low. Therefore, BMSCs are suitable for cell transplantation. Research has shown that BMSCs are potential to repair neurological defect. OBJECTIVE: To determine whether in vitro cultured BMSCs can be transplanted to repair peripheral nerve injury or not, and to investigate its mechanisms. DESIGN, TIME AND SETTING: Randomized controlled animal study This study was performed in Department of Toxicology, Public Health College of Jilin University from March 2006 to March 2007.MATERIALS: Fifty healthy female Wistar rats aging 2 months and six 1-week-old female Wistar rats were used for extraction of BMSCs. Rabbit-anti-nerve growth factor (NGF) monoclonal antibody was provided by Santa Cruz Company. METHODS:BMSCs were separated and cultured with adherent method. In the 3rd generation, BMSCs were preiabeled with bromodeoxyuridine (BrdU) 48 hours before transplantation. Fifty healthy Wistar rats were selected to prepare sciatic nerve crush injury models with clamping method.Subsequently, rats were randomly divided into transplantation group and control group, with 25 rats in each group. Rats in the transplantation group underwent transplantation of BrdU-labeied BMSCs at nerve injured sites; while, the same volume DMEM was injected into rats in the control group. MAIN OUTCOME MEASURES: Injured nerve in the transplantation group suffered from anti-BrdU staining 1, 2, 4, and 6 weeks after surgery. Distal injured nerve in both groups suffered from NGF immunohistochemical staining 1, 2, 4, and 6 weeks after surgery. Image analysis system was adopted to analyze integrated absorbance of positive expression. Gait analysis was performed every week after surgery to measure sciatic nerve function index, and it was also adopted to measure regenerated nerve conduction velocity 6 weeks after surgery. Subsequently, amount and inner diameter of medullated nerve fibers were calculated after luxol fast blue staining, while wet weight of experimental-lateral gastrocnemius muscle and cross section area of muscle fiber were measured at the same time. RESULTS: Fifty rats were included in the final analysis. BrdU-labeled positive cells could be found at injured nerve in the transplantation group 1, 2, and 4 weeks after surgery. Integrated absorbance of NGF protein expression in the transplantation group was significantly higher than that in the control group 1 and 2 weeks after surgery (P < 0.01), but there were no significant differences between the two groups 4 and 6 weeks after surgery (P > 0.05). Sciatic nerve function index in the transplantation group superiorly recovered to that in the control group 3-6 weeks after surgery. Furthermore, 6 weeks after surgery, nerve conduction velocity, amount and diameter of medullated nerve fibers, wet weight and cross section area of gastrocnemius muscle in the transplantation group were significantly higher than those in the control group (P < 0.05-0.01). CONCLUSION: BMSCs can be transplantated into injuried nerve tissue, and promote the recovery of nerve function in the micro-enviroment, improve NGF expression in an early phase may be one of its mechanisms.
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Objective To study the repairment of pancreas mesenchymal stem cells(MSCs) on injured pancreas of rats,and find a new source of cells for treatment of diabetes. Methods ① Pancreases were taken out of three-day-old Wistar rats under bioclean condition,and cells were obtained by V-collagenase digestion. Generations were passed by conventional culture,cells were purified by adherence screening method,cell morphous was observed by Giemsa staining. The expressions of surface marker CD34 and CD44 were determined by FCM,and compared with bone marrow MSCs(BM-MSCs),the differences in character and function were observed. ②The experimental rats were divided into two groups randomly. Pancreas ischemic necrosis model was made by deligation,then the purified pancreas MSCs were marked with DAPI and then were transplantated partially. After two weeks,the survival rate was measured and histopathological detection was performed. Results ① The cells had concordant morphous gradually with vigorous generation. There was no significant difference in morphology and surface antigen compared with BM-MSCs.② The survival rate in experimental group was 75% ,the necrotic tissue had basi-rebounded. Blue fluorescent was observed in repaired pancreas tissues. The survival rate in control group was 20%. The survival rate in experimental group was higher than that in control group (P