The cellular basis of bone marrow （BM） tissue development and regeneration is mediated through hematopoietic stem cells （HSCs） and mesenchymal stem cells （MSCs）. Local interplays between hematopoietic cells and ...The cellular basis of bone marrow （BM） tissue development and regeneration is mediated through hematopoietic stem cells （HSCs） and mesenchymal stem cells （MSCs）. Local interplays between hematopoietic cells and BM stromal cells （BMSCs） determine the reconstitution of hematopoiesis after myelosuppression. Here we review the BM local signals in control of BM regeneration after insults. Hematopoietic growth factors （HGFs） and cytokines produced by BMSCs are primary factors in regulation ofBM hematopoiesis. Morphogens which are critical to early embryo development in multiple species have been added to the family of HSCs regulators, including families of Wnt proteins, Notch ligands, BMPs, and Hedgehogs. Global gene expression analysis of HSCs and BMSCs has begun to reveal signature groups of genes for both cell types. More importantly, analysis of global gene expression coupled with biochemical and biological studies of local signals during BM regeneration have strongly suggested that HGFs and cytokines may not be the primary local regulators for BM recovery, rather chemokines （SDF- 1, FGF-4） and angiogenic growth factors （VEGF-A, Ang- 1） play instructive roles in BM reconstitution after myelosuppression. A new direction of management of BM toxicity is emerging from the identification of BM regenerative regulators.展开更多
AIM:To investigate the effects of adeno-associated virus (AAV) mediated expression of human interferon-γ for gene therapy in experimental hepatic fibrosis in vitro and in vivo. METHODS: We constructed the recombinant...AIM:To investigate the effects of adeno-associated virus (AAV) mediated expression of human interferon-γ for gene therapy in experimental hepatic fibrosis in vitro and in vivo. METHODS: We constructed the recombinant AAV encoding human INF-γ (rAAV- INF-γ) and took the primary rat hepatic stellate cells and carbon tetrachloride induced rats as the experimental hepatic fibrosis model in vitro and in vivo. Immunocytochemistry analysis was used to reveal the expression of α-SMA, the marker protein expressed in hepatic stellate cells. The mRNA expression of TGF-β, TIMP-1, and MMP-13 were analyzed by RT-PCR method. In vivo study, the hydroxyproline content in liver and serum AST, ALT were also detected. RESULTS: In vitro study, AAV vector could mediated efficient expression of human INF-γ, which inhibit the activation of hepatic stellate cells, decrease the expression of α-SMA and mRNA of TIMP-1, TGF-β, with the MMP-13 unchanged. In vivo study, the histological examination revealed that rAAV- INF-γ could inhibit the progression of the hepatic fibrosis. In the rAAV-INF-γ induced group, the hydroxyproline content and serum AST, ALT level were decreased to 177±28 μg/g wet liver, 668.5±140.0, 458.4±123.5 U/L, compare with the fibrosis control group 236±31 μg/g wet liver, 1 019.1±276.3, 770.5±154.3 U/L, respectively (P<0.01). mRNA expression of TIMP-1 in the rAAV-INF-γ induced rat liver was decreased while no significant change was observed in TGF-β and MMP-13. CONCLUSION: All these results indicated that rAAV-INF-γ has potential effects for gene therapy of hepatic fibrosis, which could inhibit the progression of hepatic fibrosis.展开更多
AIM: To explore the dynamic changes in the pressure of the lateral ventricle during acute brainstem hemorrhage and the changes of neural discharge of vagus nerve under the load of intracranial hypertension, so as to a...AIM: To explore the dynamic changes in the pressure of the lateral ventricle during acute brainstem hemorrhage and the changes of neural discharge of vagus nerve under the load of intracranial hypertension, so as to analyze their effects on the congestive degree of intestinal mucous membrane and the morphologic changes of intestinal mucous membrane.METHODS: An operation was made to open the skull to obtain an acute brainstem hemorrhage animal model.Microcirculatory microscope photography device and video recording system were used to determine the changes continuously in the caliber of jejunal mesenteric artery during brainstem hemorrhage and the changes with time in the congestion of jejunal mucosal villi. We used HE stain morphology to analyze the changes of duodenal mucosal villi. A recording electrode was used to calculate and measure the electric discharge activities of cervical vagus nerve.RESULTS: (1) We observed that the pressure of lateral cerebral ventricle increased transiently during acute brainstem hemorrhage; (2) The caliber of the jejunal mesenteric artery increased during brainstem hemorrhage.Analysis of red color coordinate values indicated transient increase in the congestion of jejunal mucous membrane during acute brainstem hemorrhage; (3) Through the analysis of the pathologic slice, we found enlarged blood vessels, stagnant blood, and transudatory red blood cells in the duodenal submucous layer; (4) Electric discharge of vagus nerve increased and sporadic hemorrhage spots occurred in duodenal mucous and submucous layer, when the lateral ventricle was under pressure.CONCLUSION: Brainstem hemorrhage could causeintracranial hypertension, which would increase the neural discharge of vagus nerve and cause the transient congestion of jejunal mucous membrane. It could cause hyperemia and diffused hemorrhage in the duodenal submucous layer 48 h after brainstem hemorrhage.展开更多
Viruses are obligatory intracellular parasites. Most of the cells in animaland human body possess the innate ability to fight viruses. Innate immune function restrictsinfection at the early stage and delay spread of v...Viruses are obligatory intracellular parasites. Most of the cells in animaland human body possess the innate ability to fight viruses. Innate immune function restrictsinfection at the early stage and delay spread of virus. The early stage of infection is the stage ofinteraction between the virus and the host's defence system. Once the latter is breached, the earlynon-specific or innate immune components such as interferon (IFN), natural killer (NK) cells andmacrophages become active. As the infection proceeds, the adaptive (specific) immune responsedevelops, with the appearance of cytotoxic T cells, helper T cells and antiviral antibodies.Antibodies provide a major barrier to virus spread between cells and cells and are particularlyimportant in restriction of virus spread in the blood stream. Virus infection directly activates thetranscription of type Ⅰ IFN (IFN-alfa/beta) genes in infected cells, while the type Ⅱ IFN(IFN-gamma) plays an essential role in the regulation of an adaptive immune response rather thaninnate immune response. Therefore, Type Ⅰ IFN is the first defence for host and neighbouring cellsto resist virus infection.展开更多
This paper focuses on the relationship between firm risk profile, agency incentives and corporate performance using correlation study and cross-sectional approach. We conceptualise firm risk profile using the balanced...This paper focuses on the relationship between firm risk profile, agency incentives and corporate performance using correlation study and cross-sectional approach. We conceptualise firm risk profile using the balanced score card and differ from previous studies, on the above variables, by capturing the perceptual sets of strategic leadership of Ugandan firms who are members of corporate governance of Uganda. We post a significant negative relationship between firm risk profile and corporate performance, a significant negative relationship between firm risk profile and agency incentives and a positive relationship between agency incentives and corporate performance By employing Joseph and Scott （2006）＇s utilization of the balanced score card to identify the four forms of firm risk （namely, financial, customer, internal and learning and growth risks）, our results support the application of agency theory as a relevant theoretical framework for dealing with managers who are risk averse.展开更多
Embryonic stem cells and adult stem cells derives from bone marrow, muscule, liver, skin, nerve, adiposes and other tissues or organs are pluripotent. Embryonic stem cells in vitro can differentiate into derivatives o...Embryonic stem cells and adult stem cells derives from bone marrow, muscule, liver, skin, nerve, adiposes and other tissues or organs are pluripotent. Embryonic stem cells in vitro can differentiate into derivatives of all three embryonic germ layers when transferred to an in vitro environment, and have the ability to form any fully differentiated cells of the body. A series of remarkable studies suggested that adult stem cells undergo novel patterns of development named as transdifferentiation. All of them can be induced into cardiomyocytes in a certain condition and used to treat myocardial infarction. In this review, progress in the treatment of myocardial infarction with stem cells transplantation is summarized.展开更多
文摘The cellular basis of bone marrow （BM） tissue development and regeneration is mediated through hematopoietic stem cells （HSCs） and mesenchymal stem cells （MSCs）. Local interplays between hematopoietic cells and BM stromal cells （BMSCs） determine the reconstitution of hematopoiesis after myelosuppression. Here we review the BM local signals in control of BM regeneration after insults. Hematopoietic growth factors （HGFs） and cytokines produced by BMSCs are primary factors in regulation ofBM hematopoiesis. Morphogens which are critical to early embryo development in multiple species have been added to the family of HSCs regulators, including families of Wnt proteins, Notch ligands, BMPs, and Hedgehogs. Global gene expression analysis of HSCs and BMSCs has begun to reveal signature groups of genes for both cell types. More importantly, analysis of global gene expression coupled with biochemical and biological studies of local signals during BM regeneration have strongly suggested that HGFs and cytokines may not be the primary local regulators for BM recovery, rather chemokines （SDF- 1, FGF-4） and angiogenic growth factors （VEGF-A, Ang- 1） play instructive roles in BM reconstitution after myelosuppression. A new direction of management of BM toxicity is emerging from the identification of BM regenerative regulators.
基金Supported by the National High Technology Research and Development Program of China, 863 Program, No. 2003AA2Z347A
文摘AIM:To investigate the effects of adeno-associated virus (AAV) mediated expression of human interferon-γ for gene therapy in experimental hepatic fibrosis in vitro and in vivo. METHODS: We constructed the recombinant AAV encoding human INF-γ (rAAV- INF-γ) and took the primary rat hepatic stellate cells and carbon tetrachloride induced rats as the experimental hepatic fibrosis model in vitro and in vivo. Immunocytochemistry analysis was used to reveal the expression of α-SMA, the marker protein expressed in hepatic stellate cells. The mRNA expression of TGF-β, TIMP-1, and MMP-13 were analyzed by RT-PCR method. In vivo study, the hydroxyproline content in liver and serum AST, ALT were also detected. RESULTS: In vitro study, AAV vector could mediated efficient expression of human INF-γ, which inhibit the activation of hepatic stellate cells, decrease the expression of α-SMA and mRNA of TIMP-1, TGF-β, with the MMP-13 unchanged. In vivo study, the histological examination revealed that rAAV- INF-γ could inhibit the progression of the hepatic fibrosis. In the rAAV-INF-γ induced group, the hydroxyproline content and serum AST, ALT level were decreased to 177±28 μg/g wet liver, 668.5±140.0, 458.4±123.5 U/L, compare with the fibrosis control group 236±31 μg/g wet liver, 1 019.1±276.3, 770.5±154.3 U/L, respectively (P<0.01). mRNA expression of TIMP-1 in the rAAV-INF-γ induced rat liver was decreased while no significant change was observed in TGF-β and MMP-13. CONCLUSION: All these results indicated that rAAV-INF-γ has potential effects for gene therapy of hepatic fibrosis, which could inhibit the progression of hepatic fibrosis.
基金Supported by the Natural Science Foundation of Tianjin, No.023610711and the Project Sponsored by SRF for ROCS, SEMthe Teaching Research Foundation of Tianjin Medical University
文摘AIM: To explore the dynamic changes in the pressure of the lateral ventricle during acute brainstem hemorrhage and the changes of neural discharge of vagus nerve under the load of intracranial hypertension, so as to analyze their effects on the congestive degree of intestinal mucous membrane and the morphologic changes of intestinal mucous membrane.METHODS: An operation was made to open the skull to obtain an acute brainstem hemorrhage animal model.Microcirculatory microscope photography device and video recording system were used to determine the changes continuously in the caliber of jejunal mesenteric artery during brainstem hemorrhage and the changes with time in the congestion of jejunal mucosal villi. We used HE stain morphology to analyze the changes of duodenal mucosal villi. A recording electrode was used to calculate and measure the electric discharge activities of cervical vagus nerve.RESULTS: (1) We observed that the pressure of lateral cerebral ventricle increased transiently during acute brainstem hemorrhage; (2) The caliber of the jejunal mesenteric artery increased during brainstem hemorrhage.Analysis of red color coordinate values indicated transient increase in the congestion of jejunal mucous membrane during acute brainstem hemorrhage; (3) Through the analysis of the pathologic slice, we found enlarged blood vessels, stagnant blood, and transudatory red blood cells in the duodenal submucous layer; (4) Electric discharge of vagus nerve increased and sporadic hemorrhage spots occurred in duodenal mucous and submucous layer, when the lateral ventricle was under pressure.CONCLUSION: Brainstem hemorrhage could causeintracranial hypertension, which would increase the neural discharge of vagus nerve and cause the transient congestion of jejunal mucous membrane. It could cause hyperemia and diffused hemorrhage in the duodenal submucous layer 48 h after brainstem hemorrhage.
文摘Viruses are obligatory intracellular parasites. Most of the cells in animaland human body possess the innate ability to fight viruses. Innate immune function restrictsinfection at the early stage and delay spread of virus. The early stage of infection is the stage ofinteraction between the virus and the host's defence system. Once the latter is breached, the earlynon-specific or innate immune components such as interferon (IFN), natural killer (NK) cells andmacrophages become active. As the infection proceeds, the adaptive (specific) immune responsedevelops, with the appearance of cytotoxic T cells, helper T cells and antiviral antibodies.Antibodies provide a major barrier to virus spread between cells and cells and are particularlyimportant in restriction of virus spread in the blood stream. Virus infection directly activates thetranscription of type Ⅰ IFN (IFN-alfa/beta) genes in infected cells, while the type Ⅱ IFN(IFN-gamma) plays an essential role in the regulation of an adaptive immune response rather thaninnate immune response. Therefore, Type Ⅰ IFN is the first defence for host and neighbouring cellsto resist virus infection.
文摘This paper focuses on the relationship between firm risk profile, agency incentives and corporate performance using correlation study and cross-sectional approach. We conceptualise firm risk profile using the balanced score card and differ from previous studies, on the above variables, by capturing the perceptual sets of strategic leadership of Ugandan firms who are members of corporate governance of Uganda. We post a significant negative relationship between firm risk profile and corporate performance, a significant negative relationship between firm risk profile and agency incentives and a positive relationship between agency incentives and corporate performance By employing Joseph and Scott （2006）＇s utilization of the balanced score card to identify the four forms of firm risk （namely, financial, customer, internal and learning and growth risks）, our results support the application of agency theory as a relevant theoretical framework for dealing with managers who are risk averse.
文摘Embryonic stem cells and adult stem cells derives from bone marrow, muscule, liver, skin, nerve, adiposes and other tissues or organs are pluripotent. Embryonic stem cells in vitro can differentiate into derivatives of all three embryonic germ layers when transferred to an in vitro environment, and have the ability to form any fully differentiated cells of the body. A series of remarkable studies suggested that adult stem cells undergo novel patterns of development named as transdifferentiation. All of them can be induced into cardiomyocytes in a certain condition and used to treat myocardial infarction. In this review, progress in the treatment of myocardial infarction with stem cells transplantation is summarized.
