Mitogen-activated protein kinase （MAPK） cascades play important roles in regulating plant innate immune responses. In a genetic screen to search for mutants with constitutive defense responses, we identified multipl...Mitogen-activated protein kinase （MAPK） cascades play important roles in regulating plant innate immune responses. In a genetic screen to search for mutants with constitutive defense responses, we identified multiple alleles of mpk4 and mekkl that exhibit cell death and constitutive defense responses. Bimolecular fluorescence complemen- tation （BiFC） analysis showed that both MPK4 and MEKK1 interact with MKK1 and MKK2, two closely related MAPK kinases, mkkl and mkk2 single mutant plants do not have obvious mutant phenotypes. To test whether MKK1 and MKK2 function redundantly, mkkl mkk2 double mutants were generated. The mkkl mkk2 double mutant plants die at seedling stage and the seedling-lethality phenotype is temperature-dependent. Similar to the mpk4 and mekkl mutants, the mkkl mkk2 double mutant seedlings accumulate high levels of H202, display spontaneous cell death, constitutively express Pathogenesis Related （PR） genes and exhibit pathogen resistance. In addition, activation of MPK4 by fig22 is impaired in the mkkl mkk2 double mutants, suggesting that MKK1 and MKK2 function together with MPK4 and MEKK1 in a MAP kinase cascade to negatively regulate innate immune responses in plants.展开更多
Proliferative activity in 106 cases of non-Hodgkin’s lymphoma was estimated using the monoclonal antibody Ki67 and by counting the number of mitotic figures. The percentage of Ki67-positive cells was compared with th...Proliferative activity in 106 cases of non-Hodgkin’s lymphoma was estimated using the monoclonal antibody Ki67 and by counting the number of mitotic figures. The percentage of Ki67-positive cells was compared with the median number of mitotic figures per square millimeter. Both Ki67 positivity and the number of mitotic figures were found to be greater in high grade than in low grade lymphomas, although there was an overlap between the two grades of malignancy. A close correlation was found between the number of mitotic figures and the percentage of Ki67-positive cells not only in all lymphoma typo taken together (r_s= 0. 834 . P<0. 001). but also in B-cell lymphoma (r_s= 0. 8 1 P< 0. 001) and T-cell lymphoma (r_s = 0. 764. P<0. 00 1) taken seprately. Thus, both methods are useful for the estimation of proliferative activity. but each method has its advantages and disadvantages.展开更多
By means of indirect double immunofluorescent staining, the coordination of PI antigen and perichromonucleolin (PCN), the constituent of nuclear periphery and nucleolus respectively, in the assembly and disassembly of...By means of indirect double immunofluorescent staining, the coordination of PI antigen and perichromonucleolin (PCN), the constituent of nuclear periphery and nucleolus respectively, in the assembly and disassembly of chromosome pellicle during mitosis was studied. It was found that in 3T3 cells, during mitosis PI antigen began to coat the condensing chromosome .surface earlier.than PCN did. However, both of them completed their coating on chromosome at approximately the same stage of mitosis, prometaphase metaphase. The dissociation of PI antigen from chromosome pellicle to participate the formation of nuclear periphery took, place also ahead of that of PCN. At early telophase PI antigen had been extensively involved in the formation of nuclear periphery, while PCN remained in association with the surface of decondensing chromosomes. At late telophase, when PI antigen was localized in an fairly well formed nuclear periphery, PCN was in a stage of forming prenucleolar bodies.展开更多
文摘Mitogen-activated protein kinase （MAPK） cascades play important roles in regulating plant innate immune responses. In a genetic screen to search for mutants with constitutive defense responses, we identified multiple alleles of mpk4 and mekkl that exhibit cell death and constitutive defense responses. Bimolecular fluorescence complemen- tation （BiFC） analysis showed that both MPK4 and MEKK1 interact with MKK1 and MKK2, two closely related MAPK kinases, mkkl and mkk2 single mutant plants do not have obvious mutant phenotypes. To test whether MKK1 and MKK2 function redundantly, mkkl mkk2 double mutants were generated. The mkkl mkk2 double mutant plants die at seedling stage and the seedling-lethality phenotype is temperature-dependent. Similar to the mpk4 and mekkl mutants, the mkkl mkk2 double mutant seedlings accumulate high levels of H202, display spontaneous cell death, constitutively express Pathogenesis Related （PR） genes and exhibit pathogen resistance. In addition, activation of MPK4 by fig22 is impaired in the mkkl mkk2 double mutants, suggesting that MKK1 and MKK2 function together with MPK4 and MEKK1 in a MAP kinase cascade to negatively regulate innate immune responses in plants.
文摘Proliferative activity in 106 cases of non-Hodgkin’s lymphoma was estimated using the monoclonal antibody Ki67 and by counting the number of mitotic figures. The percentage of Ki67-positive cells was compared with the median number of mitotic figures per square millimeter. Both Ki67 positivity and the number of mitotic figures were found to be greater in high grade than in low grade lymphomas, although there was an overlap between the two grades of malignancy. A close correlation was found between the number of mitotic figures and the percentage of Ki67-positive cells not only in all lymphoma typo taken together (r_s= 0. 834 . P<0. 001). but also in B-cell lymphoma (r_s= 0. 8 1 P< 0. 001) and T-cell lymphoma (r_s = 0. 764. P<0. 00 1) taken seprately. Thus, both methods are useful for the estimation of proliferative activity. but each method has its advantages and disadvantages.
文摘By means of indirect double immunofluorescent staining, the coordination of PI antigen and perichromonucleolin (PCN), the constituent of nuclear periphery and nucleolus respectively, in the assembly and disassembly of chromosome pellicle during mitosis was studied. It was found that in 3T3 cells, during mitosis PI antigen began to coat the condensing chromosome .surface earlier.than PCN did. However, both of them completed their coating on chromosome at approximately the same stage of mitosis, prometaphase metaphase. The dissociation of PI antigen from chromosome pellicle to participate the formation of nuclear periphery took, place also ahead of that of PCN. At early telophase PI antigen had been extensively involved in the formation of nuclear periphery, while PCN remained in association with the surface of decondensing chromosomes. At late telophase, when PI antigen was localized in an fairly well formed nuclear periphery, PCN was in a stage of forming prenucleolar bodies.
