Stem cells are a lineage with capacities of self-renewal and multipotential differentiation. They are exactly regulated by microenvironment where they live. With the understanding of stem cells biology, researchers noticed that stem cells have many similar biology characters with tumor cells, and thought that tumors were likely derived from stem cells, and gave a concept that there were tumor stem cells in tumor tissues.

AIM: To construct a knock-out vector for ?~(maj) & ?~(min) gene of ?-globin gene and establish embryonic stem cell lines by gene knock-out in ES level for generating gene knock-out animal model. METHODS: Two homologous sequences 1.7 kb and 7.0 kb were inserted into basic plasmic vector pNTK, which contains positive and negative selection system of the neomycin resistance (Neo) and herpes simplex virus thymidine kinase (TK) resistant gene to construct a gene knock-out recombinant plasmic vector nominated ?-pNTK, which was certified by polymerase chain reaction, enzyme digested and DNA sequencing. The ?-pNTK that contains two homologous sequence was linearized with Sal I and introduced into the D3 line of ES cells by electroporation. Positive cloning of ES cells was selected with positive and negative selection system of G418 600 mg/L and 2.5 mol/L Gancyclovir for four weeks. ES cells clone were picked, explanded and certified by polymerase chain reaction, Southern blotting. Examination of the undifferentiated state and pluripotential characteristics of the cell lines were made with the alkaline phosphatase (AKP) staining and embryoid bodies formation test and teratomas formation in nude mice. RESULTS: A knock-out recombinant plasmic vector for ? maj & ? min gene of ?-globin gene, ?-pNTK, was constructed in C129 mouse, which contains 8.7 kb length inserted homologous sequence and deleted most part of the ?~(maj) & ?~(min) gene. 8 strains of positive ES cells cloning were obtained, all of them were testified positive with polymerase chain reaction and Southern blotting. The results of AKP staining, embryoid bodies formation in vitro and teratomas formation in nude mice showed undifferentiated state and pluripotential characteristic of cell line. CONCLUSIONS: A knock-out recombinant plasmic vector of ?~(maj) & ?~(min) of ?-globin gene in C129 mouse was constructed, in which a knock-out ?~(maj) & ?~(min) gene of ?-globin gene ES-D3 cell line was established by electroporation, characterization of these cells show a prospect utility in producing gene knock-out mice in blastocysts stages.

AIM: To investigate the effect of sucking porcine liver extracts (LE) and doxorubicin (DXR) on BEL-7402 hepatoma cells in the renal capsulae of BALB/c nude mice. METHODS: Histo-cellular morphology, mitotic counting, ultrastructural observation and in situ DNA labeling apoptotic detection were performed. RESULTS: Both LE and DXR can apparently inhibit the tumors' growth and induce the apotosis of hepatoma cells. LE exerted no apparent effect on the hepatoma cell mitosis, but DXR inhibited it. Electron-microscopic observations showed LE can induce the hepatoma cells to apoptosis. CONCLUSIONS: LE can induce the hepatoma cells to apoptosis, but has no apparent effect of their differentiation and proliferation. DXR can not only induce the hepatoma cells to apoptosis and inhibit their growth, but also can promote their differentiation.

BACKGROUND: Previous research has demonstrated that dermal tissue has mesenchymal stem cells, which have a possibility of autologous transplantation. If the mesenchymal stem cells derived from the skin differentiate into lymphocytes under a certain condition, the immune system disease can be solved generally.OBJECTIVE: To investigate the possibility of differentiation of human skin-derived mesenchymal stem cells into lymphocytes. METHODS: Surface marker expression was detected in the 14th passage human skin-derived mesenchymal stem cells using flow cytometry. Transdifferentiation medium of human skin-derived mesenchymal stem cells consisted of human lymphocyte supernatant and fresh human skin-derived mesenchymal stem cells based on the ratio of 7:3. Inverted microscope was employed to observe morphological changes, and flow cytometry was used to detect surface marker expression in the lymphocytes at 1-8 days after induction. Self-marker expression of human skin-derived mesenchymal stem cells was then detected at 3,6, and 9 days after induction.RESULTS AND CONCLUSION: Human skin-derived mesenchymal stem cells stably expressed self-specific marker CD73, Vimentin and so on, but did not express specific markers of hematopoietic system, I.e., CD34, CD45 and so on, lowly expressed HLA-I, but did not express HLA-DR at all. At 3 days after induction, the cell volume significantly increased, cell proliferation rate was significantly lower than before induction, and a lot of cystic-like particles with strong refraction were observed in or between cells. The CD45 lymphocyte expression was not significantly changed, but CD3, CD19, CD16, CD4, and CD8 expression rates of human skin-derived mesenchymal stem cells were linearly increased at 1-4 days after induction and stabilized at 5-8 days after induction. In addition, CD37, CD34, Vimentin, and HLA-DR expressions were not changed at 3, 6, and 9 days after induction, but HLA-I expression rate was gradually increased with the prolongation time of induction. This suggested that human skin-derived mesenchymal stem cells can differentiate into lymphocyte and potentially participate in repairing immune system injury.

OBJECTIVETo evaluate the effectiveness of small interfering RNA (siRNA) on inhibiting severe acute respiratory syndrome (SARS)-associated coronavirus replication, and to lay bases for the future clinical application of siRNA for the treatment of viral infectious diseases.

METHODSVero-E6 cells was transfected with siRNA before SARS virus infection, and the effectiveness of siRNA interference was evaluated by observing the cytopathic effect (CPE) on Vero-E6 cells.

RESULTSFive pairs of siRNA showed ability to reduce CPE dose dependently, and two of them had the best effect.

CONCLUSIONsiRNA may be effective in inhibiting SARS-associated coronavirus replication.

Animals ; Cercopithecus aethiops ; RNA, Small Interfering ; pharmacology ; SARS Virus ; drug effects ; Transfection ; Vero Cells ; Virus Replication ; drug effects

Many clinical studies on Cheezheng Xiaotong Tiegao have been accumulated since it was launched in 1993,but they have not been comprehensively analyzed and evaluated. This study systematically retrieved relevant studies in six databases at home and abroad as of December 2017. This study analyzed the statistics of the included studies in several aspects,including publication time,region,fund,disease category and type of study. In this study,various tools were used to evaluate the methodological quality of included studies,such as the Cochrane collaboration's tool for assessing the risk of bias in randomized trials,MINORS,IHE,AMSTAR2.The results showed that the literatures were mainly published from 2010 to 2011,and a total of 28 projects were financially supported.The most involved disease was arthropathy. The randomized controlled trials were the majority in the included studies,but the quality was low,and most of the literatures didn't report the allocation concealment and blinding. This study comprehensively reflected the current situations and shortcomings of the clinical studies of Cheezheng Xiaotong Tiegao,and put forward several suggestions,in the expectation of providing a reference for the future clinical research direction of Cheezheng Xiaotong Tiegao.
Bibliometrics ; Drugs, Chinese Herbal