BACKGROUND: Muscle-derived stem cells have some problems in pudflcation, amplification and directional differentiation during in vitro culture. Basic fibroblast growth factor as a membrane of bloactive factor has been paid great attention, due to its biological activity.OBJECTIVE: To explore effects of basic flbroblast growth factor on/n vitro proliferation of rat musde-derived stem cells.DESIGN, TIME AND SETTING: The cytological in vitro study was performed at the Shenyang Medical College from April to July 2008.MATERIALS: Five healthy male Wistar rats were supplied by Experimental Animal Center, Shenyang Medical College. Basic fibroblast growth factor was produced by Zhuhai Biological Product Co., Ltd.METHODS: Left anterior limb triceps brachii was sterilely obtained from rats. Muscle-derived stem cells were harvested by isolation with enzyme digestion, pudfied by density gradient centrifugation and differential attachment. At the second passage,musde-derived stem cells were treated with basic fibroblast growth factor at final concentration of 6.25, 12.50, 25.00, 50.00,100.00 pg/L. Cells received 200 uL growth medium as blank control group, and those treated with 200 μL growth medium +musde-derived stem celts as negative controls. MTT was added at 24, 48, 72 and 96 hours of culture.MAIN OUTCOME MEASURES: Immunocytochomical method was used to determine rat musde-dedved stem cells. MTT assay was utilized to detect cell proliferation.RESULTS: Musde-denved stem cells were mostly positive for Sca-1, but few was positive for Desmin. Compared with the negative control group, vanous concentrations of basic fibroblast growth factor had significant proliferation effects on musde-derived cells (P < 0.05). At 6.25-50.00 μg/L, the proliferation effect became strong with the increased concentration (P <0.01). At 50.00 μg/L, the proliferation promotion effect nearly reached a peak. Musde-derived stem cells significantly proliferated over time. Compared with the negative control group, significant proliferation promotion effect was detected in the basic fibroblast growth factor groups at 96 hours (P < 0.01).CONCLUSION: Basic fibroblast growth factor can promote proliferation of rat muscle-derived stem cells/n vitro in a dose-time dependent fashion. 50.00 μ g/L and 96 hours are separately good concentration and time for in vitro culture.

BACKGROUND: Studies on the reparation of peripheral nervous system are not only a key focus in medical research, but also a major topic for biologists, biochemical engineers and materialogy specialists. OBJECTIVE: To investigate the individual difference of ideal muscle bridging neurologic defect configuration on nerve regeneration. DESIGN, TIME AND SETTING: The control experiment was performed at the Shenyang Medical College from June 2004 to September 2005. MATERIALS: Ten common dogs weighing 20-30 kg were used in this study. METHODS: After intravenous anesthesia, muscle strips in the caudal right sartorius and middle musculus flexor digitorum superficialis of dogs were sliced into two segments. One was observed by dissection under a stereoscope. Another received Haematoxylin & Eosin (HE) Staining and transverse area of muscle fiber of distal and proximal ends was analyzed by image analysis. The same muscle strip was sutured at 2 cm neurologic defect region of autologous left and right limbs. Number of medullated nerve fibers was measured after osmic acid staining. MAIN OUTCOME MEASURES: Morphological difference of muscle bridge, transverse area of muscle fiber of distal and proximal ends, and number of medullated nerve fibers at bridging femoral nerve defect of left and right limbs. RESULTS: The muscle fiber in sartorius paralleled the longitudinal axis of muscle strip. The angle between muscle fiber in musculus flexor digitorum superficialis and the longitudinal axis of muscle strip was big. 80% muscle fiber in sartorius was equa1 to the length of the muscle bridge. Muscle fiber in the musculus flexor digitorum superficialis was shorter than the length of muscle strip. Muscle fiber in the musculus flexor digitorum superficialis was thick, whereas muscle fiber in sartorius was thin. There were significantly differences in transverse area of muscle fiber in the two kinds of muscle bridges (P

The exam under open and close condition is a new mode which is different from traditional close-exam and entire open-exam.It indicates that new exam mode not only conquers limitation of simplex close-exam,but also boosts forwardly study of students and promotes the didactical reform completely.

BACKGROUND: Studies concerning muscle-derived stem cell transplantation mainly focused on treatment of muscular dystrophy. There are no studies on muscle-derived stem cells for treatment of denervated amyotrophy combined therapy. OBJECTIVE: To explore effects of muscle-derived stem cell transplantation on denervated gastrocnemius atrophy. DESIGN, TIME AND SETTING: The randomized controlled animal study was performed at the Shenyang Medical College from February 2007 to July 2008. MATERIALS: A total of 19 adult healthy male Wistar rats were supplied by Animal Experimental Center, Shenyang Medical College. METHODS: Triceps brachii was sterilely collected from 3 rats, and muscle-derived stem cells were isolated in vitro, and purified by adherence method. The tibial nerve of right posterior limb was cut in remaining 16 rats to establish animal models of denervated gastrocnemius. In the cell transplantation group, 0.2 mL DAPI-labeled muscle-derived stem cell suspension was infused into the denervated gastrocnemius. The same volume of saline was injected into the model control group, for 4 weeks. MAIN OUTCOME MEASURES: Computer biological signal collection processing system was used to measure recovery rate of threshold intensity of gastrocnemius and the optimal intensity recovery rate. Electronic balance was utilized to calculate residual rate of wet weight. Image analysis system was used to measure residual rate of cross section area. RESULTS: Compared with the model control group, the recovery rate of threshold intensity of denervated gastrocnemius and the optimal intensity recovery rate were significantly lower in the cell transplantation group (P