ABSTRACT
Objective:To prepare the velvet antler polypeptide-collagen/chitosan composite materials,and to investigate its promotive effect on cicatrization of mandibular defect and possible mechanism.Methods:The collagen and chitosan solution were mixed.The composite material was prepared by glutaraldehyde crosslinking method.The microstructure of the composite material was observed by transmission electron microscope (SEM).The unilateral mandibular defect models of 36 rabbits were established.The rabbits were divided into experiment and control groups,and each group was divided into 4-,8-and 12-week subgroups,and there were 6 rabbits in each sub group.The rabbits in experiment group were implanted with velvet antler polypeptide-collagen /chitosan composite materials and the rabbits in control group were treated.4,8 and 12 weeks after operation,the histology of bone defect and peripheral nerve reconstruction of the rabbit models were detected by CT;the expression of vascular endothelial growth factor (VEGF) in bone tissue of the rabbits was detected by immunohistochemistry;the ultrastructure of bone defect was observed by SEM.Results:The structure of composite materials had layered folds and the inner diameter of the stent became larger and mainly dominated by sheet structure,which was the ideal structure of biological materials.4 weeks after operation,the new bone was formatted in experiment group,most of the new bone like-tissue materials were degraded,and the VEGF expression showed an increasing trend;8 weeks after operation,the trabecular bone in the bone defect of the rabbits in experiment group was increased obviously and the expression of VEGF was decreased.12 weeks after operation,the new bone formation and the density in experiment group was consistent with the normal tissue,and the expression level of VEGF returned to normal.At each the point after operation,the degree of bone defect healing and bone formation rate in experiment group were obviously prior to control group.Conclusion:Velvet antler polypeptide-collagen /chitosan composite material has the promotive effect on the fracture healing of mandibular defect of the rabbits and its possible mechanism may be related to promoting the expression of VEGF.
ABSTRACT
Objective:To explore the effects of voriconazole on the proliferation and morphology of Acanthamoeba cultivated in vitro,and to clarify the killing effects of voriconazole against the trophozoites and cysts of Acanthamoeba.Methods:The Acanthamoeba polyphaga at logarithmic phase were selected and divided into control group and experiment groups(2.5 and 25.0 mg·L-1).The Acanthamoeba in each group was collected at 24,48,72,and 96 h after drug administration,respectively.Then the concentrations of Acanthamoeba were calculated and the proliferation curves were drawn;inverted microscope was used to observe the morphology,activity and adherence of Acanthamoeba;the ultrastructures of Acanthamoeba were observed under electron microscope.Results:Compared with control group,the numbers of Acanthamoeba polyphaga in experiment groups were significantly decreased(P<0.01).The morphology of Acanthamoeba changed significantly under inverted microscope,and the shape of Acanthamoeba transformed from the trophozoites with irregular spiny filopodia to circular cysts.Even a large number of cell debris was observed.Different degrees of damage and even necrosis of Acanthamoeba in experiment groups were found under electron micro scope.Conclusion:Certain concentration of voriconazole can effectively inhibit the proliferation of Acanthamoeba and change the morphology and ultrastructure and kill the trophozoites and cysts of Acanthamoeba cultivated in vitro.
ABSTRACT
[ ABSTRACT] AIM:To investigate the effect of microwave radiation at different intensities on the rat myocardium and its possible mechanism.METHODS:The rats were radiated by the intensity of 500, 1 000, 1 500 and 2 000 W/m2 with 2 450 MHz microwave for 6 min.The heart tissue was collected 6 h after microwave radiation.ATP and mitochondria complexⅣandⅤwere measured.The changes of the tissue structures were observed under transmission electron micro-scope.The apoptosis of the myocardial cells was detected by a cell analyzer.The protein level of cleaved caspase-3 was de-termined by Western blotting.RESULTS:The concentration of ATP and activity of mitochondria complexⅣandⅤsigni-ficantly decreased compared with control group in the cardiac tissues.The decreased number, morphological abnormalities such as dissolved cavitation, matrix and obvious tumefaction of mitochondria were observed under transmission electron mi-croscope.The microwave radiation induced the apoptosis of myocardial cells in the rats.The cell apoptotic rate and the pro-tein level of cleaved caspase-3 increased with increasing intensity of microwave radiation ( P<0.05 ) .CONCLUSION:Microwave radiation has obvious injury effect on the rat heart, which can cause cardiac energy metabolism dysregulation and cardiac myocyte apoptosis.
ABSTRACT
Objective To study the protective effect and mechanism of Inonotus obliquus polysaccharide on liver injury induced by isoniazid( INH) combined with rifampicin( RFP) in mice. Methods Forty-eight mice were randomly divided into six groups ( control, model, huganpian, Inonotus obliquus polysaccharide at low, middle, and high dose ) . The mice were administered orally with isoniazid and rifampicin simultaneously except the control. After 2 h,the control and model groups were administered with normal saline,and others were treated with huganpian and Inonotus obliquus polysaccharide,respectively,once a day for 2 weeks. The liver index and serum levels of ALT and AST,malondialdehyde(MDA),superoxide dismutase(SOD) and glutathione peroxidase( GPx) were measured. Pathology examination of liver tissue was performed. Results The activities of ALT and AST, liver index, content of MDA in liver homogenate of mice treated with Inonotus obliquus polysaccharide and huganpian decreased obviously, while the liver SOD activity increased. Histopathological exzamination showed that Inonotus obliquus polysaccharide alleviated the degeneration and necrosis of hepatic cells. Conclusion Inonotus obliquus polysaccharide shows protective effects on mice with hepatic toxic injury induced by isoniazid and rifampicin,which maybe due to its antioxidation effect.