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Objective To investigate the membrane topology of transient receptor potential(TRP)channel. Methods Glycosylation method was used to investigate the membrane integrations of each hydrophobic segment of canonical TRP(TRPC5). Results In TRPC5 channel,S4?S8 segments were integrated into membrane with Ncyt/Cexo and Nexo/Ccyt orientations sequentially ,and C?terminus was intracellular. S1?S3 segments were integrated into membrane with two possible types. One was that S1 and S3 were integrated into membrane,whereas S2 was left out of the membrane on the cytosolic side;and the other was a mixed type that S1 and S3 were exposed to cytoplasm respectively. Both of them,the N?termi?nus was intracellular. Conclusion S4?S8 segments of TRPC5 are transmembrane segments. The integrations of S1?S3 segments into membrane need to be further investigated.
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Objective:To study the expression of 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxodG) in oral leukoplakia for clarifying the role of oxidative DNA damage in the development of oral leukoplakia. Methods:Immunofluorescence labeling method was used to examine the expression of 8-oxodG,a marker of oxidative DNA damage,and the expression of tumor suppressor gene, P53 protein in oral epithelium of normal oral mucosa and biopsy specimens of leukoplakia. Results:In specimens of oral leukoplakia, HE staining showed infiltration of inflammatory cells, hyperkeratosis and epithelial dysplasia. Immunofluorescence labeling study demonstrated that the accumulation of 8-oxodG apparently increased in the oral epithelium of patients with leukoplakia,whereas little or no immunoreactivity was observed in normal oral mucosa. Expression of P53 protein was also observed in oral epithelium of patients with oral leukoplakia. The immunoreactivity of 8-oxodG and P53 was stronger in patients with oral leukoplakia than that in normal oral mucosa (P<0.01) . Moreover,the immunoreactivity increased with the development of disease (r=0.773, P<0.01) . Conclusions:The oxidative DNA damage contributes to the development of oral leukoplakia. 8-oxodG may be a risk predictive marker for oral leukoplakia.
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BACKGROUND:Skin transplantation is regarded as the most effective therapy for large-area skin defects, which is limited by donor sources and immune rejection. Therefore, it is extremely accelerate the construction of the dermis in skin tissue engineering. OBJECTIVE:To investigate the effects of bone marrow mesenchymal stem cels/calcium alginate gel, basic fibroblast growth factor and degradation membrane on the repair of ful-thickness skin defects. METHODS:Bone marrow mesenchymal stem cels were isolated from 15 New Zealand rabbits, and then cultured, amplified, subcultured and purified. Three ful-thickness skin defects were made on the back of every rabbit, and randomly treated with bone marrow mesenchymal stem cels/calcium alginate gel, basic fibroblast growth factor and degradation membrane as experimental group, bone marrow mesenchymal stem cels/calcium alginate gel as control 1 group, and calcium alginate gel as control 2 group. The wounds were al covered with amniotic membrane. After 7, 14, 21 days, new wound tissues were taken for hematoxylin-eosin staining, immunohistochemistry staining and image analysis. RESULTS AND CONCLUSION: Dermis tissues in the experimental group were obviously thicker than those in control 1 and control 2 groups; there were more fibroblasts, vessels and colagen fibers in the experimental group. Especialy at 14 and 21 days after operation, epidermal hyperplasia was faster with a larger coverage area in the experimental group, and at 21 days, the new epidermal tissues mainly exhibited multi-layered structure, which was superior to the control 1 and 2 groups. It folows that the combination of bone marrow mesenchymal stem cels/calcium alginate gel, basic fibroblast growth factor and degradation membrane for skin defects can accelerate the repair and regeneration of the dermis, and thus promote the epidermis regeneration and reconstruction.
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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
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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
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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.