177 research outputs found

    二種の血清型特異性,すなわち血清型4のVP3と血清型3のVP7を有する組換え体ヒトロタウイルスの作製

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    The reassortment of viral genome segments has been reported to occur during coinfection of cultured cells with two different rotaviruses. Further, epidemiologic findings suggesting that genetic reassortment of viral RNAs may account for an antigenic shift in rotavirus in nature have also been accumulated. In the present study a reassortant virus, C148, was selected from fifty-one progeny virus clones obtained under an antibody pressure from a mixed infection of MA104 cells with human rotavirus serotype 3 (YO) and serotype 4 (Hochi) strains. Antigenic characterization and genotype analysis by polyacrylamide gel electrophoresis concluded that C148 virus possessed a mosaic antigenicity defined by two serotype-specific viral proteins (VP), i. e. the serotype 4-specific VP3 and the serotype 3-specific VP7. While the reassortant C148 was judged to belong to serotype 3 on the basis of its preferential neutralizability by serotype 3 antiserum, the antiserum prepared against C148 equally neutralized both serotype 3 and 4 viruses. These results seem to further support the possible emergence of a genetic reassortant in nature between human rotaviruses beloneinu to different serotypes

    The molecular chaperone heat shock protein-90 positively regulates rotavirus infection

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    AbstractRotaviruses are the major cause of severe dehydrating gastroenteritis in children worldwide. In this study, we report a positive role of cellular chaperone Hsp90 during rotavirus infection. A highly specific Hsp90 inhibitor, 17-allylamono-demethoxygeldanamycin (17-AAG) was used to delineate the functional role of Hsp90. In MA104 cells treated with 17-AAG after viral adsorption, replication of simian (SA11) or human (KU) strains was attenuated as assessed by quantitating both plaque forming units and expression of viral genes. Phosphorylation of Akt and NFκB observed 2–4 hpi with SA11, was strongly inhibited in the presence of 17-AAG. Direct Hsp90–Akt interaction in virus infected cells was also reduced in the presence of 17-AAG. Anti-rotaviral effects of 17-AAG were due to inhibition of activation of Akt that was confirmed since, PI3K/Akt inhibitors attenuated rotavirus growth significantly. Thus, Hsp90 regulates rotavirus by modulating cellular signaling proteins. The results highlight the importance of cellular proteins during rotavirus infection and the possibility of targeting cellular chaperones for developing new anti-rotaviral strategies

    Geographic Distribution of Arbovirus Antibodies in Indigenous Human Populations in the Indo-Australian Archipelago

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    Sera from lifetime residents in 16 localities of the Indo-Australian archipelago and adjacent areas were tested for hemagglutination-inhibition antibody against four alphaviruses (Sindbis, Getah, chikungunya, and Ross River) and for neutralizing antibody against six flaviviruses (dengue 2 and 3, Japanese encephalitis, Murray Valley encephalitis, Kunjin, and Edge Hill). Mosquito collections were carried out in some of the localities to study vector relationships to distribution of the arbovirus antibodies. Antibodies specific to Sindbis and Getah viruses were rare except in north Australia. Chikungunya virus-specific antibody was highly prevalent in localities of the Oriental zoogeographic region and Wallacea, rare in west New Guinea, and absent in north Australia. Age distribution of chikungunya antibody suggested that the antibody last occurred in most Indonesian localities about 30 years ago. Ross River virus-specific antibody was confined to localities of the Australian zoogeographic region. Antibodies reacting to dengue 2 and 3 viruses occurred in high frequency in the entire area of the archipelago. Antibodies specific to Murray Valley encephalitis and Kunjin viruses were also widespread although at a very low frequency. Japanese encephalitis virus-specific antibody was highly prevalent in areas west of Wallace\u27s Line while it was absent in areas east of the line with the exception of Lombok. Antibody to Edge Hill virus was rare and confined to the Australian zoogeographic region. The distribution of arthropod vectors, vertebrate hosts, and of arboviruses are discussed in relation to zoogeographic divisions

    World Robot Challenge 2020 -- Partner Robot: A Data-Driven Approach for Room Tidying with Mobile Manipulator

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    Tidying up a household environment using a mobile manipulator poses various challenges in robotics, such as adaptation to large real-world environmental variations, and safe and robust deployment in the presence of humans.The Partner Robot Challenge in World Robot Challenge (WRC) 2020, a global competition held in September 2021, benchmarked tidying tasks in the real home environments, and importantly, tested for full system performances.For this challenge, we developed an entire household service robot system, which leverages a data-driven approach to adapt to numerous edge cases that occur during the execution, instead of classical manual pre-programmed solutions. In this paper, we describe the core ingredients of the proposed robot system, including visual recognition, object manipulation, and motion planning. Our robot system won the second prize, verifying the effectiveness and potential of data-driven robot systems for mobile manipulation in home environments

    Effects of Titanium Dioxide Nanoparticle Aggregate Size on Gene Expression

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    Titanium dioxide (titania) nanoparticle aggregation is an important factor in understanding cytotoxicity. However, the effect of the aggregate size of nanoparticles on cells is unclear. We prepared two sizes of titania aggregate particles and investigated their biological activity by analyzing biomarker expression based on mRNA expression analysis. The aggregate particle sizes of small and large aggregated titania were 166 nm (PDI = 0.291) and 596 nm (PDI = 0.417), respectively. These two size groups were separated by centrifugation from the same initial nanoparticle sample. We analyzed the gene expression of biomarkers focused on stress, inflammation, and cytotoxicity. Large titania aggregates show a larger effect on cell viability and gene expression when compared with the small aggregates. This suggests that particle aggregate size is related to cellular effects
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