AIM: Recent reports have shown the capacity of mesenchymal stem cells (MSCs) to differentiate into hepatocytes in vitro and in vivo. MSCs administration could repair injured liver, lung, or heart through reducing infl...AIM: Recent reports have shown the capacity of mesenchymal stem cells (MSCs) to differentiate into hepatocytes in vitro and in vivo. MSCs administration could repair injured liver, lung, or heart through reducing inflammation, collagen deposition, and remodeling. These results provide a clue to treatment of liver fibrosis. The aim of this study was to investigate the effect of infusion of bone marrow (BM)-derived MSCs on the experimental liver fibrosis in rats. METHODS: MSCs isolated from BM in male Fischer 344 rats were infused to female Wistar rats induced with carbon tetrachloride (CCI4) or dimethylnitrosamine (DMN). There were two random groups on the 42nd d of CCI4: CCl4/MSCs, to infuse a dose of MSCs alone; CCI4/saline, to infuse the same volume of saline as control. There were another three random groups after exposure to DMN: DMN10/MSCs, to infuse the same dose of MSCs on d 10; DMN10/saline, to infuse the same volume of saline on d 10; DMN20/MSCs, to infuse the same dose of MSCs on d 20. The morphological and behavioral changes of rats were monitored everyday. After 4-6 wk of MSCs administration, all rats were killed and fibrosis index were assessed by histopathology and radioimmunoassay. Smooth muscle alpha-actin (alpha-SMA) of liver were tested by immunohistochemistry and quantified by IBAS 2.5 software. Male rats sex determination region on the Y chromosome (sry) gene were explored by PCR. RESULTS: Compared to controls, infusion of MSCs reduced the mortality rates of incidence in CCl4-induced model (10% vs 20%) and in DMN-induced model (20-40% vs 90%).The amount of collagen deposition and alpha-SMA staining was about 40-50% lower in liver of rats with MSCs than that of rats without MSCs. The similar results were observed in fibrosis index. And the effect of the inhibition of fibrogenesis was greater in DMN10/MSCs than in DMN20/MSCs. The sry gene was positive in the liver of rats with MSCs treatment by PCR. CONCLUSION: MSCs treatment can protect against experimental liver fibrosis in CCMnduced or DMN-induced rats and the mechanisms of the anti-fibrosis by MSCs will be studied further.展开更多
To develop a novel degradable poly (L-lactic acid)/β-tricalcium phosphate (PLLA/β-TCP) bioactive materials for bone tissueengineering, β-TCP powder was produced by a new wet process. Porous scaffolds were prepared ...To develop a novel degradable poly (L-lactic acid)/β-tricalcium phosphate (PLLA/β-TCP) bioactive materials for bone tissueengineering, β-TCP powder was produced by a new wet process. Porous scaffolds were prepared by three steps, i.e. solventcasting, compression molding and leaching stage. Factors influencing the compressive strength and the degradation behaviorof the porous scaffold, e.g. weight fraction of pore forming agent-sodium chloride (NaCl), weight ratio of PLLA: β-TCP,the particle size of β-TCP and the porosity, were discussed in details. Rat marrow stromal cells (RMSC) were incorporatedinto the composite by tissue engineering approach. Biological and osteogenesis potential of the composite scaffold weredetermined with MTT assay, alkaline phosphatase (ALP) activity and bone osteocalcin (OCN) content evaluation. Resultsshow that PLLA/β-TCP bioactive porous scaffold has good mechanical and pore structure with adjustable compressive strengthneeded for surgery. RMSCs seeding on porous PLLA/β-TCP composite behaves good seeding efficacy, biocompatibility andosteoinductive potential. Osteoprogenitor cells could well penetrate into the material matrix and begin cell proliferation andosteogenic differentiation. Osseous matrix could be formed on the surface of the composite after culturing in vitro. It isexpected that the PLLA/β-TCP porous composites are promising scaffolds for bone tissue engineering in prosthesis surgery.展开更多
AIM: To establish nested-PCR methods for the detection of SENV-D and SENV-H and to investigate the epidemiology of SEN virus in China.METHODS: According to published gene sequences,primers from the conserved region we...AIM: To establish nested-PCR methods for the detection of SENV-D and SENV-H and to investigate the epidemiology of SEN virus in China.METHODS: According to published gene sequences,primers from the conserved region were designed. Then,235 samples from healthy voluntary blood donors and 242 samples from patients with various forms of liver disease were detected by nested-PCR of SENV-D/H. Some PCR products were cloned and sequenced.RESULTS: By sequencing, the specificity of genotype-specific PCR was confirmed. SENV-D/H DNA was detected in 31% of the blood donors, which was higher than those in America and Italy (2%), and in Japan and Taiwan (15-20%).The prevalence of SENV-D/H viremia was significantly higher in patients with hepatitis B and hepatitis C than in blood donors (59-85% vs 31%, P<0.05). The prevalence among patients with non-A-E hepatitis was significantly higher than among blood donors (68% vs 31%, P<0.01),and equivalent to that among patients with hepatitis B and C.CONCLUSION: Nested-PCR with genotype-specific primerscould serve as a useful SENV screening assay. SENV has the same transmission modes as HBV and HCV. The high prevalence in patients with non-A-E hepatitis may attribute to the transmission modes, and SENV may not serve as the causative agents.展开更多
基金Supported by the Major State Basic Research Development Program of China (973 Program),No. 2001CB509904 the Key Scientific and Technological Projects of Guangdong Province, No. 2003A3020103+1 种基金the Key Scientific and Technological Projects of Guangzhou City, No. 2002U13E0011the National Natural Science Foundation of China, No. 30100188
文摘AIM: Recent reports have shown the capacity of mesenchymal stem cells (MSCs) to differentiate into hepatocytes in vitro and in vivo. MSCs administration could repair injured liver, lung, or heart through reducing inflammation, collagen deposition, and remodeling. These results provide a clue to treatment of liver fibrosis. The aim of this study was to investigate the effect of infusion of bone marrow (BM)-derived MSCs on the experimental liver fibrosis in rats. METHODS: MSCs isolated from BM in male Fischer 344 rats were infused to female Wistar rats induced with carbon tetrachloride (CCI4) or dimethylnitrosamine (DMN). There were two random groups on the 42nd d of CCI4: CCl4/MSCs, to infuse a dose of MSCs alone; CCI4/saline, to infuse the same volume of saline as control. There were another three random groups after exposure to DMN: DMN10/MSCs, to infuse the same dose of MSCs on d 10; DMN10/saline, to infuse the same volume of saline on d 10; DMN20/MSCs, to infuse the same dose of MSCs on d 20. The morphological and behavioral changes of rats were monitored everyday. After 4-6 wk of MSCs administration, all rats were killed and fibrosis index were assessed by histopathology and radioimmunoassay. Smooth muscle alpha-actin (alpha-SMA) of liver were tested by immunohistochemistry and quantified by IBAS 2.5 software. Male rats sex determination region on the Y chromosome (sry) gene were explored by PCR. RESULTS: Compared to controls, infusion of MSCs reduced the mortality rates of incidence in CCl4-induced model (10% vs 20%) and in DMN-induced model (20-40% vs 90%).The amount of collagen deposition and alpha-SMA staining was about 40-50% lower in liver of rats with MSCs than that of rats without MSCs. The similar results were observed in fibrosis index. And the effect of the inhibition of fibrogenesis was greater in DMN10/MSCs than in DMN20/MSCs. The sry gene was positive in the liver of rats with MSCs treatment by PCR. CONCLUSION: MSCs treatment can protect against experimental liver fibrosis in CCMnduced or DMN-induced rats and the mechanisms of the anti-fibrosis by MSCs will be studied further.
基金This study was financially supported by 863 Hj-Tech ResearchDevelopment Program of China(2002AA326080)The Fund for Youth Teacher of Education Mlinistry of China(2002123).
文摘To develop a novel degradable poly (L-lactic acid)/β-tricalcium phosphate (PLLA/β-TCP) bioactive materials for bone tissueengineering, β-TCP powder was produced by a new wet process. Porous scaffolds were prepared by three steps, i.e. solventcasting, compression molding and leaching stage. Factors influencing the compressive strength and the degradation behaviorof the porous scaffold, e.g. weight fraction of pore forming agent-sodium chloride (NaCl), weight ratio of PLLA: β-TCP,the particle size of β-TCP and the porosity, were discussed in details. Rat marrow stromal cells (RMSC) were incorporatedinto the composite by tissue engineering approach. Biological and osteogenesis potential of the composite scaffold weredetermined with MTT assay, alkaline phosphatase (ALP) activity and bone osteocalcin (OCN) content evaluation. Resultsshow that PLLA/β-TCP bioactive porous scaffold has good mechanical and pore structure with adjustable compressive strengthneeded for surgery. RMSCs seeding on porous PLLA/β-TCP composite behaves good seeding efficacy, biocompatibility andosteoinductive potential. Osteoprogenitor cells could well penetrate into the material matrix and begin cell proliferation andosteogenic differentiation. Osseous matrix could be formed on the surface of the composite after culturing in vitro. It isexpected that the PLLA/β-TCP porous composites are promising scaffolds for bone tissue engineering in prosthesis surgery.
基金Supported by the Innovation Foundation of Academy of Military Medical Sciences,No.200104
文摘AIM: To establish nested-PCR methods for the detection of SENV-D and SENV-H and to investigate the epidemiology of SEN virus in China.METHODS: According to published gene sequences,primers from the conserved region were designed. Then,235 samples from healthy voluntary blood donors and 242 samples from patients with various forms of liver disease were detected by nested-PCR of SENV-D/H. Some PCR products were cloned and sequenced.RESULTS: By sequencing, the specificity of genotype-specific PCR was confirmed. SENV-D/H DNA was detected in 31% of the blood donors, which was higher than those in America and Italy (2%), and in Japan and Taiwan (15-20%).The prevalence of SENV-D/H viremia was significantly higher in patients with hepatitis B and hepatitis C than in blood donors (59-85% vs 31%, P<0.05). The prevalence among patients with non-A-E hepatitis was significantly higher than among blood donors (68% vs 31%, P<0.01),and equivalent to that among patients with hepatitis B and C.CONCLUSION: Nested-PCR with genotype-specific primerscould serve as a useful SENV screening assay. SENV has the same transmission modes as HBV and HCV. The high prevalence in patients with non-A-E hepatitis may attribute to the transmission modes, and SENV may not serve as the causative agents.
