AIM: To investigate the different effects of mesenchymal stem cells (MSCs) and hematopoietic stem cells (HSCs) on hepatic differentiation.METHODS: MSCs from rat bone marrow were isolated and cultured by standard metho...AIM: To investigate the different effects of mesenchymal stem cells (MSCs) and hematopoietic stem cells (HSCs) on hepatic differentiation.METHODS: MSCs from rat bone marrow were isolated and cultured by standard methods. HSCs from rat bone marrow were isolated and purified by magnetic activated cell sorting. Both cell subsets were induced. Morphology, RT-PCR and immunocytochemistry were used to identify the hepatic differentiation grade.RESULTS: MSCs exhibited round in shape after differentiation, instead of fibroblast-like morphology before differentiation. Albumin mRNA and protein were expressed positively in MSCs, without detection of alpha-fetoprotein (AFP). HSCs were polygonal in shape after differentiation. The expression of albumin signal decreased and AFP signal increased. The expression of CK18 was continuous in MSCs and HSCs both before and after induction.CONCLUSION: Both MSCs and HSCs have hepatic differentiation capabilities. However, their capabilities are not the same. MSCs can differentiate into mature hepatocyte-like cells, never expressing early hepatic specific genes, while Thy-1.1^+cells are incllned to differentiate into hepatic stem cell-like cells, with an increasing AFP expression and a decreasing albumin signal. CK18 mRNA is positive in Thy-1.1^+ cells and MSCs, negative in Thy-1.1^+ cells. It seems that CK18 has some relationship with Thy-1.1 antigen, and CK18 may be a predictive marker of hepatic differentiation capability.展开更多
AIM: To determine whether dendritic cells (DCs) from chronic hepatitis B patients could induce HBV antigenspecific T cell responses or not. METHODS: DCs were generated from peripheral blood mononuclear cells of patien...AIM: To determine whether dendritic cells (DCs) from chronic hepatitis B patients could induce HBV antigenspecific T cell responses or not. METHODS: DCs were generated from peripheral blood mononuclear cells of patients with chronic hepatitis B (CHB) infection and healthy donors. We compared the phenotypes of these DCs and their ability to secrete cytokines and to participate in mixed lymphocyte reactions. In addition, autologous lymphocytes were cultured with DCs loaded with HBV core region peptide HBcAg8-27, an epitope recognized by cytotoxic T lymphocytes(CTL), and bearing human leucocyte antigen (HLA)-A2 for 10 d. Cytokine secretion and lytic activity against peptide-pulsed target cells were assessed. RESULTS: DCs with typical morphology were generated successfully by culturing peripheral blood mononuclear cells (PBMCs) from CriB patients with AIM-V containing GM-CSF and IL-4. Compared with DCs from normal donors, the level of CD80 expressed in DCs from CHB patients was lower, and DCs from patients had lower capacity of stimulate T cell proliferation. When PBMCs isolated from patients with chronic or acute hepatitis B infection and from normal donors were cocultured with HBcAg18-27 peptide, the antigen-specific memory response of PBMCs from acute hepatitis B patients was stronger than that of PBMCs from chronic hepatitis B patients or normal donors. PBMCs cocultured with DCs treated with HBcAg18-27 CTL epitope peptide induced an antigen-specific T cell reaction, in which the level of secreted cytokines and lyric activity were higher than those produced by memory T cells. CONCLUSION: DCs from patients with CHB can induce HBV antigen-specific T cell reactions, including secretion of cytokines essential for HBV clearance and for killing cells infected with HBV.展开更多
In this paper a new method is developed to make a dynamic layout adjustmentand navigation for enterprise Geographic Information System (GIS) based on object mark recognition.The extraction of object mark images is bas...In this paper a new method is developed to make a dynamic layout adjustmentand navigation for enterprise Geographic Information System (GIS) based on object mark recognition.The extraction of object mark images is based on some morphological structural patterns, which aredescribed by morphological structural points, contour property, and other geometrical data in abinary image of enterprise geographic information map. Some pre-processing methods, contour smoothfollowing, linearization and extraction patterns of structural points, are introduced. If anyspecial object is selected to make a decision in a GIS map, the all information around it will beobtained. That is, we need to investigate similar object enterprises around selected region toanalyse whether it is necessary for establishing the object enterprise at that place. To furthernavigate GIS map, we need to move from one region to another. Each time a region is formed anddisplayed based on the user's focus. If a focus point of a map is selected, in terms of extractedobject mark image, a dynamic layout and navigation diagram is constructed. When the user changes thefocus (i. e. click a node in the navigation mode), a new sub-diagram is formed by dropping oldnodes and adding new nodes. The prototype system provides effective interfaces that support GISimage navigation, detailed local image/map viewing, and enterprise information browsing.展开更多
基金Supported by the National High Technology Research and Development Program of China (863 Program),No.2001AA216031
文摘AIM: To investigate the different effects of mesenchymal stem cells (MSCs) and hematopoietic stem cells (HSCs) on hepatic differentiation.METHODS: MSCs from rat bone marrow were isolated and cultured by standard methods. HSCs from rat bone marrow were isolated and purified by magnetic activated cell sorting. Both cell subsets were induced. Morphology, RT-PCR and immunocytochemistry were used to identify the hepatic differentiation grade.RESULTS: MSCs exhibited round in shape after differentiation, instead of fibroblast-like morphology before differentiation. Albumin mRNA and protein were expressed positively in MSCs, without detection of alpha-fetoprotein (AFP). HSCs were polygonal in shape after differentiation. The expression of albumin signal decreased and AFP signal increased. The expression of CK18 was continuous in MSCs and HSCs both before and after induction.CONCLUSION: Both MSCs and HSCs have hepatic differentiation capabilities. However, their capabilities are not the same. MSCs can differentiate into mature hepatocyte-like cells, never expressing early hepatic specific genes, while Thy-1.1^+cells are incllned to differentiate into hepatic stem cell-like cells, with an increasing AFP expression and a decreasing albumin signal. CK18 mRNA is positive in Thy-1.1^+ cells and MSCs, negative in Thy-1.1^+ cells. It seems that CK18 has some relationship with Thy-1.1 antigen, and CK18 may be a predictive marker of hepatic differentiation capability.
基金Supported by"973"Program No.G1999054106,National NaturalScience Foundation of China,No.30170047 and"863"Program No.2001AA217151 and No.2002AA217071
文摘AIM: To determine whether dendritic cells (DCs) from chronic hepatitis B patients could induce HBV antigenspecific T cell responses or not. METHODS: DCs were generated from peripheral blood mononuclear cells of patients with chronic hepatitis B (CHB) infection and healthy donors. We compared the phenotypes of these DCs and their ability to secrete cytokines and to participate in mixed lymphocyte reactions. In addition, autologous lymphocytes were cultured with DCs loaded with HBV core region peptide HBcAg8-27, an epitope recognized by cytotoxic T lymphocytes(CTL), and bearing human leucocyte antigen (HLA)-A2 for 10 d. Cytokine secretion and lytic activity against peptide-pulsed target cells were assessed. RESULTS: DCs with typical morphology were generated successfully by culturing peripheral blood mononuclear cells (PBMCs) from CriB patients with AIM-V containing GM-CSF and IL-4. Compared with DCs from normal donors, the level of CD80 expressed in DCs from CHB patients was lower, and DCs from patients had lower capacity of stimulate T cell proliferation. When PBMCs isolated from patients with chronic or acute hepatitis B infection and from normal donors were cocultured with HBcAg18-27 peptide, the antigen-specific memory response of PBMCs from acute hepatitis B patients was stronger than that of PBMCs from chronic hepatitis B patients or normal donors. PBMCs cocultured with DCs treated with HBcAg18-27 CTL epitope peptide induced an antigen-specific T cell reaction, in which the level of secreted cytokines and lyric activity were higher than those produced by memory T cells. CONCLUSION: DCs from patients with CHB can induce HBV antigen-specific T cell reactions, including secretion of cytokines essential for HBV clearance and for killing cells infected with HBV.
基金an Australian Research Council SPIRT grant(C00107573).
文摘In this paper a new method is developed to make a dynamic layout adjustmentand navigation for enterprise Geographic Information System (GIS) based on object mark recognition.The extraction of object mark images is based on some morphological structural patterns, which aredescribed by morphological structural points, contour property, and other geometrical data in abinary image of enterprise geographic information map. Some pre-processing methods, contour smoothfollowing, linearization and extraction patterns of structural points, are introduced. If anyspecial object is selected to make a decision in a GIS map, the all information around it will beobtained. That is, we need to investigate similar object enterprises around selected region toanalyse whether it is necessary for establishing the object enterprise at that place. To furthernavigate GIS map, we need to move from one region to another. Each time a region is formed anddisplayed based on the user's focus. If a focus point of a map is selected, in terms of extractedobject mark image, a dynamic layout and navigation diagram is constructed. When the user changes thefocus (i. e. click a node in the navigation mode), a new sub-diagram is formed by dropping oldnodes and adding new nodes. The prototype system provides effective interfaces that support GISimage navigation, detailed local image/map viewing, and enterprise information browsing.
