[Objective] This study was to investigate the relationship between biological characteristics of Beauveria bassiana （Bals.） Vuill and pathogenicity to Bombyx rnori L, with the aim to provide scientific basis for the...[Objective] This study was to investigate the relationship between biological characteristics of Beauveria bassiana （Bals.） Vuill and pathogenicity to Bombyx rnori L, with the aim to provide scientific basis for the control of white muscardine in Bombyx mori L. [Method] The strains isolated and purified from the 6 Beauveria bassiana biocontrol agents from all over the country and the 3 white muscardine silkworms collected from Guangxi provincial silkworm rearing areas were identified by the morphological observation and molecular biology technology. The pathogenicity of B. bassaina to silkworms was determined, and the biological characteristics such as growth diameter, sporulation and the extracellular protease activity of the different B. bassiana strains were compared. [Result] The isolated 9 strains were all B. bassaina （Bals.） Vuillemin, and all strains had high pathogenicity to silkworm, but with different pathogenicities. The growth diameter, sporulation and extracellular protease activity of different B. bassiana strains were also different, and showed correlation with the patheogenicity to silkworms. [Conclusion] B. bassiana spores production amount and exocellular protease activity had significant positive correlation with their pathogenicity to silkworm.展开更多
Lesions of Baló ’ s concentric sclerosis are characterized by alternating l ayers of myelinated and demyelinated tissue. The reason for concentric demyelina tion in this variant of multiple sclerosis is unclear....Lesions of Baló ’ s concentric sclerosis are characterized by alternating l ayers of myelinated and demyelinated tissue. The reason for concentric demyelina tion in this variant of multiple sclerosis is unclear. In the present study we i nvestigated the immunopathology in autopsy tissue of 14 patients with acute mult iple sclerosis or fulminant exacerbations of chronic multiple sclerosis with Bal ó - type lesions in the CNS, focusing on the patterns of tissue injury in acti vely demyelinating lesions.We found that all active concentric lesions followed a pattern of demyelination that bears resemblance s to hypoxia- like tissue injury. This was associated with high expression of i nducible nitric oxide synthase in macrophages and microglia. At the edge of acti ve lesions and, less consistently, in the outermost layer of preserved myelin, p roteins involved in tissue preconditioning,such as hypoxia- inducible factor 1 α and heat- shock protein 70, were expressed mainly in oligodendrocytes and t o a lesser degree also in astrocytes and macrophages. Due to their neuroprotecti ve effects, the rim of periplaque tissue, where these proteins are expressed, ma y be resistant to further damage in an expanding lesion and may therefore remain as a layer of preserved myelinated tissue.展开更多
基金Supported by the Scientific Research and Technology Development Planning Program of Guangxi Province(10169-08)the Program for the Construction of Key Laboratory of Ecology of Rare and Endangered Species and Environmental Protection(Guikeneng1001Z014)~~
文摘[Objective] This study was to investigate the relationship between biological characteristics of Beauveria bassiana （Bals.） Vuill and pathogenicity to Bombyx rnori L, with the aim to provide scientific basis for the control of white muscardine in Bombyx mori L. [Method] The strains isolated and purified from the 6 Beauveria bassiana biocontrol agents from all over the country and the 3 white muscardine silkworms collected from Guangxi provincial silkworm rearing areas were identified by the morphological observation and molecular biology technology. The pathogenicity of B. bassaina to silkworms was determined, and the biological characteristics such as growth diameter, sporulation and the extracellular protease activity of the different B. bassiana strains were compared. [Result] The isolated 9 strains were all B. bassaina （Bals.） Vuillemin, and all strains had high pathogenicity to silkworm, but with different pathogenicities. The growth diameter, sporulation and extracellular protease activity of different B. bassiana strains were also different, and showed correlation with the patheogenicity to silkworms. [Conclusion] B. bassiana spores production amount and exocellular protease activity had significant positive correlation with their pathogenicity to silkworm.
文摘Lesions of Baló ’ s concentric sclerosis are characterized by alternating l ayers of myelinated and demyelinated tissue. The reason for concentric demyelina tion in this variant of multiple sclerosis is unclear. In the present study we i nvestigated the immunopathology in autopsy tissue of 14 patients with acute mult iple sclerosis or fulminant exacerbations of chronic multiple sclerosis with Bal ó - type lesions in the CNS, focusing on the patterns of tissue injury in acti vely demyelinating lesions.We found that all active concentric lesions followed a pattern of demyelination that bears resemblance s to hypoxia- like tissue injury. This was associated with high expression of i nducible nitric oxide synthase in macrophages and microglia. At the edge of acti ve lesions and, less consistently, in the outermost layer of preserved myelin, p roteins involved in tissue preconditioning,such as hypoxia- inducible factor 1 α and heat- shock protein 70, were expressed mainly in oligodendrocytes and t o a lesser degree also in astrocytes and macrophages. Due to their neuroprotecti ve effects, the rim of periplaque tissue, where these proteins are expressed, ma y be resistant to further damage in an expanding lesion and may therefore remain as a layer of preserved myelinated tissue.
