Through the methods of correlation analysis and main factor analysis, the relationship between the poplar INA bacte-rial canker and circumstances was analyzed and 9 main factors for affecting the disease were selected...Through the methods of correlation analysis and main factor analysis, the relationship between the poplar INA bacte-rial canker and circumstances was analyzed and 9 main factors for affecting the disease were selected. Based on the compre-hensive analysis of main factors and induced factors, the standard for risk grades of this disease was promoted and northeast region of China was divided into 4 districts with different risk grades: seriously occurring district, commonly occurring district, occasionally occurring district, and un-occurring district. Nonlinear regression analysis for six model curves showed that the Richard growth model was suitable for describing the temporal dynamics of poplar INA bacterial canker. By stepwise variable selection method, the multi-variable linear regression forecasting equation was set up to predict the next year抯 disease index, and the GM (1,1) model was also set up by grey method to submit middle or long period forecast.展开更多
Al-3B master alloy is a kind of efficient grain refiner for hypoeutectic Al-Si alloys. Experiments were carried out to evaluate the effect of undissolved AlB2 particles in Al-3B master alloy on the grain refinement of...Al-3B master alloy is a kind of efficient grain refiner for hypoeutectic Al-Si alloys. Experiments were carried out to evaluate the effect of undissolved AlB2 particles in Al-3B master alloy on the grain refinement of Al-7Si. It is found that the number and the settlement of AlB2 particles in the melt all have effect on the grain refining efficiency. On the basis of experiments and theoretical analysis, a new grain refinement mechanism was proposed to explain the grain refinement action of Al-3B on hypoeutectic Al-Si alloys. The formation of ＇Al-AlB2＇ shell structure is the direct reason for grain refinement and the undissolved AlB2 particles is the indirect nucleating base for subsequent α（Al） phase.展开更多
Objective： Laser capture microdisection has become indispensable to the analysis of the difference of gene expression between human bladder transitional cell and bladder transitional cell carcinoma （BTCC）. However,...Objective： Laser capture microdisection has become indispensable to the analysis of the difference of gene expression between human bladder transitional cell and bladder transitional cell carcinoma （BTCC）. However, to obtain sufficient RNA from laser-capture microdissected cells is quite difficult. The study was designed to determinc a feasible technical routine to isolate transitional cells from bladder membrane, separate carcinoma cclls from stromal cells and to amplify the RNA isolated from laser-capture microdissected cells. Methods： Bladder transitional cell were obtained from frozen sections of bladder membrane applying LCM, by the same token, BTCC cells from frozen sections of BTCC tissue. Then RNA was extracted and linearly amplified in vitro. The expression levels of β-actin in primary total RNA and amplified RNA were detected using RT-PCR. Results： That RNA integrity was good after LCM was confirmed by control experiment Ⅰ; By control experiment Ⅱ, the correlation between the number of LCM-shooting and RNA quantity undcr arranged conditions was preliminarily confirmed. About 0.5-2.5kb RNA fragments were obtained after RNA amplification and β-actin levels were integral. Conclusion： Laser capture microdissection combined with RNA linear amplification in vitro can be successfully applied to obtain pure objective cells for research. The integrity of the amplified RNA is good and can be employed in further research.展开更多
AIM: In hepatocellular carcinoma (HCC) prevalent areas of China, the point mutation of p53 exon7 is highly correlated with Hepatitis B virus(HBV) infection and aflatoxin B intake. While in non-HCC-prevalent areas of C...AIM: In hepatocellular carcinoma (HCC) prevalent areas of China, the point mutation of p53 exon7 is highly correlated with Hepatitis B virus(HBV) infection and aflatoxin B intake. While in non-HCC-prevalent areas of China, these factors are not so important in the etiology of HCC. Therefore, the point mutation of p53 exon7 may also be different than that in HCC-prevalent areas of China. The aim of this study is to investigate the status and carcinogenic role of the point mutation of p53 gene exon7 in hepatocellular carcinoma from Anhui Province, a non-HCC-prevalent area in China. METHODS: PCR PCR-SSCP and PCR-RFLP were applied to analyze the homozygous deletion and point mutation of p53 exon7 in HCC samples from Anhui, which were confirmed by DNA sequencing and Genbank comparison. RESULTS: In the 38 samples of hepatocellular carcinoma, no homozygous deletion of p53 exon7 was detected and point mutations of p53 exon7 were found in 4 cases, which were found to be heterozygous mutation of codon 249 with a mutation rate of 10.53%(4/38). The third base mutation(G-T) of p53 codon 249 was found by DNA sequencing and Genbank comparison. CONCLUSION: The incidence of point mutation of p53 codon 249 is lower in hepatocellular carcinoma and the heterozygous mutation of p53 exon7 found in these patients only indicate that they have genetic susceptibility to HCC. p53 codon 249 is a hotspot of p53 exon7 point mutation, suggesting that the point mutation of p53 exon 7 may not play a major role in the carcinogenesis of HCC in Anhui Province, a non-HCC-prevalent area in China.展开更多
We demonstrate the feasibility of performing a systematic screen for human gene functions in Drosophila by assaying for their ability to induce overexpression phenotypes. Over 1 500 transgenic fly lines corresponding ...We demonstrate the feasibility of performing a systematic screen for human gene functions in Drosophila by assaying for their ability to induce overexpression phenotypes. Over 1 500 transgenic fly lines corresponding to 236 human genes have been established. In all, 51 lines are capable of eliciting a phenotype suggesting that the human genes are functional. These heterologous genes are functionally relevant as we have found a similar mutant phenotype caused either by a dominant negative mutant form of the human ribosomal protein L8 gene or by RNAi downregulation of the Drosophila RPL8. Significantly, the Drosophila RPL8 mutant can be rescued by wild-type human RPL8. We also provide genetic evidence that Drosophila RPL8 is a new member of the insulin signaling pathway. In summary, the functions of many human genes appear to be highly conserved, and the ability to identify them in Drosophila represents a powerful genetic tool for large-scale analysis of human transcripts in vivo.展开更多
Hepatocellular carcinoma (HCC) is the commonest primary malignant cancer of the liver in the world. Given that the burden of chronic liver disease is expected to rise owing to increasing rates of alcoholism, hepatitis...Hepatocellular carcinoma (HCC) is the commonest primary malignant cancer of the liver in the world. Given that the burden of chronic liver disease is expected to rise owing to increasing rates of alcoholism, hepatitis B and C prevalence and obesity-related fatty liver disease, it is expected that the incidence of HCC will also increase in the foreseeable future. This article summarizes the international epidemiology, the risk factors and the pathogenesis of HCC, including the roles of viral hepatitis, toxins, such as alcohol and aflatoxin, and insulin resistance.展开更多
The corrosion degradation behavior of a Mg-Ca alloy with high Ca content aiming for a potential bone repair material in the simulated body fluid（SBF） was investigated.The microstructure and phase constitution of the...The corrosion degradation behavior of a Mg-Ca alloy with high Ca content aiming for a potential bone repair material in the simulated body fluid（SBF） was investigated.The microstructure and phase constitution of the pristine Mg-30%Ca（mass fraction） alloy were characterized with scanning electron microscopy（SEM） and X-ray diffraction（XRD）.The Mg-30%Ca alloy samples were immersed in the SBF for 90 d,and the morphology,composition and cytotoxicity of the final corrosion product were examined.It is found that Mg-30%Ca alloy is composed of α-Mg and Mg2 Ca phases.During the corrosion process in the SBF,the Mg2 Ca phase acts as an anode and the α-Mg phase acts as a cathode.The final corrosion product of the Mg-30%Ca alloy in SBF includes a small amount of black precipitates and white suspended particles.The white suspended particles are Mg（OH）2 and the black particles are believed to have a core-shell structure.The cytotoxicity experiments indicate that these black precipitates do not induce toxicity to cells.展开更多
The stiffness and nanotopographical characteristics of the extracellular matrix （ECM） influence numerous developmental, physiological, and pathological processes in vivo. These biophysical cues have therefore been a...The stiffness and nanotopographical characteristics of the extracellular matrix （ECM） influence numerous developmental, physiological, and pathological processes in vivo. These biophysical cues have therefore been applied to modulate almost all aspects of cell behavior, from cell adhesion and spreading to proliferation and differentiation. Delineation of the biophysical modulation of cell behavior is critical to the rational design of new biomaterials, implants, and medical devices. The effects of stiffness and topographical cues on cell behavior have previously been reviewed, respectively; however, the interwoven effects of stiffness and nanotopographical cues on cell behavior have not been well described, despite similarities in phenotypic manifestations. Herein, we first review the effects of substrate stiffness and nanotopography on cell behavior, and then focus on intracellular transmission of the biophysical signals from integrins to nucleus. Attempts are made to connect extracellular regulation of cell behavior with the biophysical cues. We then discuss the challenges in dissecting the biophysical regulation of cell behavior and in translating the mechanistic understanding of these cues to tissue engineering and regenerative medicine.展开更多
Trogocytosis is a rapid transfer between cells of membranes and associated proteins. Trogocytic exchanges have been investigated between different cell types, mainly in two-cell systems, involving one donor and one ac...Trogocytosis is a rapid transfer between cells of membranes and associated proteins. Trogocytic exchanges have been investigated between different cell types, mainly in two-cell systems, involving one donor and one acceptor cell type. Here, we studied trogocytosis in a more complex system, involving not only several immune cell subsets but also multiple tumor cells. We show that CD4~ T cells, CD8＋ T cells and monocytes can acquire membrane patches and the intact proteins they contain from different tumor cells by multiple simultaneous trogocytoses. The trogocytic ca- pabilities of CD4~ and CD8~ T cells were found to be similar, but inferior to that of autologous monocytes. Activated peripheral-blood mononuclear cells （PBMCs） may also exchange membranes between themselves in an all-autolo- gous system. For this reason, monocytes are capable of acquiring membranes from multiple tumor cell sources, and transfer them again to autologous T cells, along with some of their own membranes （serial trogocytosis）. Our data illustrate the extent of membrane exchanges between autologous activated immune effector cells and their environ- ment, and how the cellular content of the local environment, including ＂bystander＂ cells, may impact the functions of immune effector cells.展开更多
基金National Foundation of Ninth Five-Year Plan (No. 96-005-04-01-03).
文摘Through the methods of correlation analysis and main factor analysis, the relationship between the poplar INA bacte-rial canker and circumstances was analyzed and 9 main factors for affecting the disease were selected. Based on the compre-hensive analysis of main factors and induced factors, the standard for risk grades of this disease was promoted and northeast region of China was divided into 4 districts with different risk grades: seriously occurring district, commonly occurring district, occasionally occurring district, and un-occurring district. Nonlinear regression analysis for six model curves showed that the Richard growth model was suitable for describing the temporal dynamics of poplar INA bacterial canker. By stepwise variable selection method, the multi-variable linear regression forecasting equation was set up to predict the next year抯 disease index, and the GM (1,1) model was also set up by grey method to submit middle or long period forecast.
基金Project supported by Tsinghua-Wuxi Science Foundation, China
文摘Al-3B master alloy is a kind of efficient grain refiner for hypoeutectic Al-Si alloys. Experiments were carried out to evaluate the effect of undissolved AlB2 particles in Al-3B master alloy on the grain refinement of Al-7Si. It is found that the number and the settlement of AlB2 particles in the melt all have effect on the grain refining efficiency. On the basis of experiments and theoretical analysis, a new grain refinement mechanism was proposed to explain the grain refinement action of Al-3B on hypoeutectic Al-Si alloys. The formation of ＇Al-AlB2＇ shell structure is the direct reason for grain refinement and the undissolved AlB2 particles is the indirect nucleating base for subsequent α（Al） phase.
文摘Objective： Laser capture microdisection has become indispensable to the analysis of the difference of gene expression between human bladder transitional cell and bladder transitional cell carcinoma （BTCC）. However, to obtain sufficient RNA from laser-capture microdissected cells is quite difficult. The study was designed to determinc a feasible technical routine to isolate transitional cells from bladder membrane, separate carcinoma cclls from stromal cells and to amplify the RNA isolated from laser-capture microdissected cells. Methods： Bladder transitional cell were obtained from frozen sections of bladder membrane applying LCM, by the same token, BTCC cells from frozen sections of BTCC tissue. Then RNA was extracted and linearly amplified in vitro. The expression levels of β-actin in primary total RNA and amplified RNA were detected using RT-PCR. Results： That RNA integrity was good after LCM was confirmed by control experiment Ⅰ; By control experiment Ⅱ, the correlation between the number of LCM-shooting and RNA quantity undcr arranged conditions was preliminarily confirmed. About 0.5-2.5kb RNA fragments were obtained after RNA amplification and β-actin levels were integral. Conclusion： Laser capture microdissection combined with RNA linear amplification in vitro can be successfully applied to obtain pure objective cells for research. The integrity of the amplified RNA is good and can be employed in further research.
基金the Natural Science Foundation of Anhui Province,No.99044312(WY) and No.9741006(LX)Natural Science Foundation of Anhui Educational Commission,No.JL-97-077(WY).
文摘AIM: In hepatocellular carcinoma (HCC) prevalent areas of China, the point mutation of p53 exon7 is highly correlated with Hepatitis B virus(HBV) infection and aflatoxin B intake. While in non-HCC-prevalent areas of China, these factors are not so important in the etiology of HCC. Therefore, the point mutation of p53 exon7 may also be different than that in HCC-prevalent areas of China. The aim of this study is to investigate the status and carcinogenic role of the point mutation of p53 gene exon7 in hepatocellular carcinoma from Anhui Province, a non-HCC-prevalent area in China. METHODS: PCR PCR-SSCP and PCR-RFLP were applied to analyze the homozygous deletion and point mutation of p53 exon7 in HCC samples from Anhui, which were confirmed by DNA sequencing and Genbank comparison. RESULTS: In the 38 samples of hepatocellular carcinoma, no homozygous deletion of p53 exon7 was detected and point mutations of p53 exon7 were found in 4 cases, which were found to be heterozygous mutation of codon 249 with a mutation rate of 10.53%(4/38). The third base mutation(G-T) of p53 codon 249 was found by DNA sequencing and Genbank comparison. CONCLUSION: The incidence of point mutation of p53 codon 249 is lower in hepatocellular carcinoma and the heterozygous mutation of p53 exon7 found in these patients only indicate that they have genetic susceptibility to HCC. p53 codon 249 is a hotspot of p53 exon7 point mutation, suggesting that the point mutation of p53 exon 7 may not play a major role in the carcinogenesis of HCC in Anhui Province, a non-HCC-prevalent area in China.
基金We are grateful to Xizhi Ma, Junnian Zhou, Tianhong Xu, Xu Liu, Xu Ding, Yang Liu, Ying Peng, Congwu Chi, Yiying Shang, Mingyao Ying, Sheng Ding, Lei Sun, Lei Tian, Huanhu Zhu, Hua Huang, Hongmei Li, and Xiaomo Wu for cDNA constructs and partial transgenic work, and Lihui Zhou （East China University of Science and Technology, China） for scanning electron microscopy. We thank Duc Nguyen （Yale University, USA） for critical reading and editing of this manuscript. This work is supported by grants from the National Natural Science Foundation of China （Grant Nos. 30030080, 39970408 and 30470840）, National Basic Research Program of China （973） （Grant No. 2006CB806700）.
文摘We demonstrate the feasibility of performing a systematic screen for human gene functions in Drosophila by assaying for their ability to induce overexpression phenotypes. Over 1 500 transgenic fly lines corresponding to 236 human genes have been established. In all, 51 lines are capable of eliciting a phenotype suggesting that the human genes are functional. These heterologous genes are functionally relevant as we have found a similar mutant phenotype caused either by a dominant negative mutant form of the human ribosomal protein L8 gene or by RNAi downregulation of the Drosophila RPL8. Significantly, the Drosophila RPL8 mutant can be rescued by wild-type human RPL8. We also provide genetic evidence that Drosophila RPL8 is a new member of the insulin signaling pathway. In summary, the functions of many human genes appear to be highly conserved, and the ability to identify them in Drosophila represents a powerful genetic tool for large-scale analysis of human transcripts in vivo.
基金The NIHR Biomedical Research Centre funding scheme and the following for authors’ funding and support: AIG is funded by a scholarship from the Egyptian Government SAK is supported by a grant from the Higher Education Funding Council for England (HEFCE)+5 种基金 SDTR is funded by grants from the British Medical Research Council (MRC), London, United Kingdomthe British Engineering, Physics and Science Research Council (EPSRC), Swindon, United Kingdomthe Alan Morement Memorial Fund AMMF, Essex, UK Broad Foundation, Los Angeles, United StatesPfizer Global Research and Development Inc, Sandwich, United Kingdom GlaxoSmithKline, Ware, United Kingdom
文摘Hepatocellular carcinoma (HCC) is the commonest primary malignant cancer of the liver in the world. Given that the burden of chronic liver disease is expected to rise owing to increasing rates of alcoholism, hepatitis B and C prevalence and obesity-related fatty liver disease, it is expected that the incidence of HCC will also increase in the foreseeable future. This article summarizes the international epidemiology, the risk factors and the pathogenesis of HCC, including the roles of viral hepatitis, toxins, such as alcohol and aflatoxin, and insulin resistance.
基金Project(51271131)supported by the National Natural Science Foundation of China
文摘The corrosion degradation behavior of a Mg-Ca alloy with high Ca content aiming for a potential bone repair material in the simulated body fluid（SBF） was investigated.The microstructure and phase constitution of the pristine Mg-30%Ca（mass fraction） alloy were characterized with scanning electron microscopy（SEM） and X-ray diffraction（XRD）.The Mg-30%Ca alloy samples were immersed in the SBF for 90 d,and the morphology,composition and cytotoxicity of the final corrosion product were examined.It is found that Mg-30%Ca alloy is composed of α-Mg and Mg2 Ca phases.During the corrosion process in the SBF,the Mg2 Ca phase acts as an anode and the α-Mg phase acts as a cathode.The final corrosion product of the Mg-30%Ca alloy in SBF includes a small amount of black precipitates and white suspended particles.The white suspended particles are Mg（OH）2 and the black particles are believed to have a core-shell structure.The cytotoxicity experiments indicate that these black precipitates do not induce toxicity to cells.
基金The authors would like to acknowledge funding support for Yong Yang from the National Science Foundation （CBET 1511759） and the National Institute of Health （NIH） （R15GM122953）, and for Kam W. Leong from NIH （HL109442, AI096305, GMl10494, and UH3 TR000505）, Guangdong Innovative and Entrepreneurial Research Team Program （2013S086）, and the Global Research Laboratory Program （Korean NSF GRL 2015032163）.
文摘The stiffness and nanotopographical characteristics of the extracellular matrix （ECM） influence numerous developmental, physiological, and pathological processes in vivo. These biophysical cues have therefore been applied to modulate almost all aspects of cell behavior, from cell adhesion and spreading to proliferation and differentiation. Delineation of the biophysical modulation of cell behavior is critical to the rational design of new biomaterials, implants, and medical devices. The effects of stiffness and topographical cues on cell behavior have previously been reviewed, respectively; however, the interwoven effects of stiffness and nanotopographical cues on cell behavior have not been well described, despite similarities in phenotypic manifestations. Herein, we first review the effects of substrate stiffness and nanotopography on cell behavior, and then focus on intracellular transmission of the biophysical signals from integrins to nucleus. Attempts are made to connect extracellular regulation of cell behavior with the biophysical cues. We then discuss the challenges in dissecting the biophysical regulation of cell behavior and in translating the mechanistic understanding of these cues to tissue engineering and regenerative medicine.
文摘Trogocytosis is a rapid transfer between cells of membranes and associated proteins. Trogocytic exchanges have been investigated between different cell types, mainly in two-cell systems, involving one donor and one acceptor cell type. Here, we studied trogocytosis in a more complex system, involving not only several immune cell subsets but also multiple tumor cells. We show that CD4~ T cells, CD8＋ T cells and monocytes can acquire membrane patches and the intact proteins they contain from different tumor cells by multiple simultaneous trogocytoses. The trogocytic ca- pabilities of CD4~ and CD8~ T cells were found to be similar, but inferior to that of autologous monocytes. Activated peripheral-blood mononuclear cells （PBMCs） may also exchange membranes between themselves in an all-autolo- gous system. For this reason, monocytes are capable of acquiring membranes from multiple tumor cell sources, and transfer them again to autologous T cells, along with some of their own membranes （serial trogocytosis）. Our data illustrate the extent of membrane exchanges between autologous activated immune effector cells and their environ- ment, and how the cellular content of the local environment, including ＂bystander＂ cells, may impact the functions of immune effector cells.
