Agriculture received most direct influences from climate changes. Because of climate changes, agricultural climate resources changed and thus influenced climate adaptability of agricultural products. The growth and ou...Agriculture received most direct influences from climate changes. Because of climate changes, agricultural climate resources changed and thus influenced climate adaptability of agricultural products. The growth and output of crops were finally affected. The calculation method and application of agricultural products in recent years were summarized. Several questions about the response of agricultural crops to climate elements were proposed for attention.展开更多
Background Most of gynecologic malignancies are sensitive to chemotherapy. Myelosuppression is the main dose-related toxicity of many chemotherapeutic drugs. The human multidrug resistance （mdrl） gene is well known ...Background Most of gynecologic malignancies are sensitive to chemotherapy. Myelosuppression is the main dose-related toxicity of many chemotherapeutic drugs. The human multidrug resistance （mdrl） gene is well known for its ability to confer drug resistance. This study aimed to explore the feasibility of expression and resistance of mdrl gene transduction into human placenta mesenchymal stem cells （P-MSCs） by retrovirus vector. Methods Human P-MSCs were isolated from trypsin-digested term placentas, and their immunophenotypes and differentiation potential were evaluated. Human P-MSCs were transduced by reconstructed retroviral vector containing the mdrl gene and green fluorescent protein （GFP） reporter gene. The integration and expression of the mdrl gene were observed indirectly by the expression of GFP, and fluorescence-activated cell sorter was used to evaluate the functional activity of permeability glycoprotein （P-gp） encoded by the mdrl gene. The stimulating test was made in vitro to show pleiotropic drug resistance of transfected cells. Results The isolated, cultured and expanded P-MSCs expressed stem cell markers such as CD29, CD44 and CD73, and showed osteogenic and adipogenic differentiation potentials under appropriate conditions. The expression of P-gp in the non-transfected P-MSCs cells was （0.4±0.1）%, but increased to （28.1±4.7）% after gene transfection （P〈0.01）. And positive staining of P-gp located mainly at cell membrane and cytoplasm. Accumulation and extrusion assays showed that P-gp expressed by the transfected cells had pump-functional activity and could efflux daunomycin out of cells. The analysis of cell survival confirmed that transfected P-MSCs had a characteristic of multidrug resistance with a significant increase in the resistance to anticancer agents. Conclusions Transfer and expression of human mdrl gene mediated by retrovirus vector conferred P-MSCs drug resistance. It might provide a new alternative to chemoprotection strategies.展开更多
Background Myelosuppression is the main dose-related toxicity of many chemotherapeutic drugs. The human multidrug resistance （mdrl） gene is well-known for its ability to confering drug resistance. In this study, we ...Background Myelosuppression is the main dose-related toxicity of many chemotherapeutic drugs. The human multidrug resistance （mdrl） gene is well-known for its ability to confering drug resistance. In this study, we meant to transplant the placenta mesenchymal stem cells （P-MSCs） moderated by mdrl gene into a nude mice model radiated by γ-Co60 and to explore the chemoprotection for bone marrow （BM） toxicity. Methods Human P-MSCs were isolated from trypsin-digested term placentas and then transduced by with reconstructed retroviral vector containing mdrl gene and green fluorescent protein （GFP） reporter gene. The integration and expression of mdrl gene was observed indirectedly by the expression of GFP. A nude mice model was constructed after irradiation with a sublethal dosage of γ-Co60. These irradiated mice were transplanted with mdrl-MSCs through the caudal vein and then received paclitaxel （PAC） intraperitoneal chemotherapy. The Peripheral peripheral blood （PB） of the nude mice was collected, and the PB cells counts and values were determined using an automatic analyzer. Results After PAC treatment, mdrl-MSCs transplanted mice showed markedly improved survival upon compared to MSCs transplanted mice （85.7% vs. 57.1%）. White blood cell （WBC） and red blood cell （RBC） counts as well as the hemoglobin （Hb） values were significantly increased in PAC treated mdrl-MSCs mice compared to PAC treated control mice when PAC chemotherapy had been finished （all P 〈0.05）, but the difference was not found in the plateltes （PLT） count （P 〉0.05）.展开更多
基金Supported by Scientific Research Special Fund for Public Welfare Industry (Meteorology) (201106020)China Meteorological BureauClimate Changes Special Fund (CCSF-09-12)
文摘Agriculture received most direct influences from climate changes. Because of climate changes, agricultural climate resources changed and thus influenced climate adaptability of agricultural products. The growth and output of crops were finally affected. The calculation method and application of agricultural products in recent years were summarized. Several questions about the response of agricultural crops to climate elements were proposed for attention.
基金his study was supported by the grants from the National Natural Science Foundation of China （No. 30471804） and the Technology Department of Jilin Province of China （No. 200505116）.
文摘Background Most of gynecologic malignancies are sensitive to chemotherapy. Myelosuppression is the main dose-related toxicity of many chemotherapeutic drugs. The human multidrug resistance （mdrl） gene is well known for its ability to confer drug resistance. This study aimed to explore the feasibility of expression and resistance of mdrl gene transduction into human placenta mesenchymal stem cells （P-MSCs） by retrovirus vector. Methods Human P-MSCs were isolated from trypsin-digested term placentas, and their immunophenotypes and differentiation potential were evaluated. Human P-MSCs were transduced by reconstructed retroviral vector containing the mdrl gene and green fluorescent protein （GFP） reporter gene. The integration and expression of the mdrl gene were observed indirectly by the expression of GFP, and fluorescence-activated cell sorter was used to evaluate the functional activity of permeability glycoprotein （P-gp） encoded by the mdrl gene. The stimulating test was made in vitro to show pleiotropic drug resistance of transfected cells. Results The isolated, cultured and expanded P-MSCs expressed stem cell markers such as CD29, CD44 and CD73, and showed osteogenic and adipogenic differentiation potentials under appropriate conditions. The expression of P-gp in the non-transfected P-MSCs cells was （0.4±0.1）%, but increased to （28.1±4.7）% after gene transfection （P〈0.01）. And positive staining of P-gp located mainly at cell membrane and cytoplasm. Accumulation and extrusion assays showed that P-gp expressed by the transfected cells had pump-functional activity and could efflux daunomycin out of cells. The analysis of cell survival confirmed that transfected P-MSCs had a characteristic of multidrug resistance with a significant increase in the resistance to anticancer agents. Conclusions Transfer and expression of human mdrl gene mediated by retrovirus vector conferred P-MSCs drug resistance. It might provide a new alternative to chemoprotection strategies.
基金This study was supported by a grant from the National Natural Science Foundation of China
文摘Background Myelosuppression is the main dose-related toxicity of many chemotherapeutic drugs. The human multidrug resistance （mdrl） gene is well-known for its ability to confering drug resistance. In this study, we meant to transplant the placenta mesenchymal stem cells （P-MSCs） moderated by mdrl gene into a nude mice model radiated by γ-Co60 and to explore the chemoprotection for bone marrow （BM） toxicity. Methods Human P-MSCs were isolated from trypsin-digested term placentas and then transduced by with reconstructed retroviral vector containing mdrl gene and green fluorescent protein （GFP） reporter gene. The integration and expression of mdrl gene was observed indirectedly by the expression of GFP. A nude mice model was constructed after irradiation with a sublethal dosage of γ-Co60. These irradiated mice were transplanted with mdrl-MSCs through the caudal vein and then received paclitaxel （PAC） intraperitoneal chemotherapy. The Peripheral peripheral blood （PB） of the nude mice was collected, and the PB cells counts and values were determined using an automatic analyzer. Results After PAC treatment, mdrl-MSCs transplanted mice showed markedly improved survival upon compared to MSCs transplanted mice （85.7% vs. 57.1%）. White blood cell （WBC） and red blood cell （RBC） counts as well as the hemoglobin （Hb） values were significantly increased in PAC treated mdrl-MSCs mice compared to PAC treated control mice when PAC chemotherapy had been finished （all P 〈0.05）, but the difference was not found in the plateltes （PLT） count （P 〉0.05）.
