105 research outputs found

    Evolutionary Selection of the Nuclear Localization Signal in the Viral Nucleoprotein Leads to Host Adaptation of the Genus Orthobornavirus.

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    Adaptation of the viral life cycle to host cells is necessary for efficient viral infection and replication. This evolutionary process has contributed to the mechanism for determining the host range of viruses. Orthobornaviruses, members of the family Bornaviridae, are non-segmented, negative-strand RNA viruses, and several genotypes have been isolated from different vertebrate species. Previous studies revealed that some genotypes isolated from avian species can replicate in mammalian cell lines, suggesting the zoonotic potential of avian orthobornaviruses. However, the mechanism by which the host specificity of orthobornaviruses is determined has not yet been identified. In this study, we found that the infectivity of orthobornaviruses is not determined at the viral entry step, mediated by the viral glycoprotein and matrix protein. Furthermore, we demonstrated that the nuclear localization signal (NLS) sequence in the viral nucleoprotein (N) has evolved under natural selection and determines the host-specific viral polymerase activity. A chimeric mammalian orthobornavirus, which has the NLS sequence of avian orthobornavirus N, exhibited a reduced propagation efficiency in mammalian cells. Our findings indicated that nuclear transport of the viral N is a determinant of the host range of orthobornaviruses, providing insights into the evolution and host adaptation of orthobornaviruses

    Sustainable development of human settlements: achievements and challenges in housing and urban policy in Latin America and the Caribbean

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    Includes bibliographyAbstract One year and a half after the United Nations Conference on Human Settlements (Habitat II) held in Istanbul, the present document aims to assess the progress made on the implementation of the Regional Plan of Action on Human Settlements for Latin America and the Caribbean. The region faces a disturbing upsurge in urban poverty and widening income inequality, notwithstanding the slower rate of population growth. A worsening of environmental problems such as air and water pollution, waste disposal and vehicle congestion is being experienced in urban centres, and the region still has both quantitative and qualitative housing shortages, despite efforts made by governments. The registered trend of reduced availability of public resources will continue in the future. The countries are implementing innovative changes in their systems to provide housing, urban services and infrastructure. The processes of decentralization and privatization opened up new spaces in the task of managing human settlements, such as the strengthening of municipal government and new integrated approaches involving participation of citizens and the private sector. The importance of environmental issues suggests that the efficiency in the management of human settlements will depend on the ability to embrace and complement the different aspects and levels that make up the real life of cities. As early as 1992, the region, aware of these problems, initiated a dialogue on human settlements, which has since then been formalized in annual meetings of ministers and high-level authorities of the housing and urban development sector of Latin America and the Caribbean (MINURVI), and has been focused on attaining the sustainable development of human settlements and participating actively in achieving the goals set forth in Habitat II

    Prevalence of Masked Obesity Associated with Lifestyle-Related Habits, Dietary Habits, and Energy Metabolism in Japanese Young Women

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    We investigated the prevalence of Masked Obesity (MO) and the correlations between MO and lifestylerelated habits (e.g., exercise habits, dieting habits), dietary habits, energy metabolism, and seasons. The subjects were 131 young Japanese college students. Body composition was measured by bioelectrical impedance method and Resting Metabolic Rate (RMR) was measured by an indirect calorimeter. Subjects with a BMI in the normal range (n=110) were divided into the MO (percentage of body fat to Body Weight [BF]≥30%) and control (C) (BF<30%) groups. Dietary energy and nutrient intakes were calculated from weighed dietary records. A questionnaire on lifestyle habits was obtained individually from the subjects. The percentage of MO was 32% of subjects within normal BMI. The prevalence of MO was the highest in winter, probably due to accumulation of body fat as an adaptation to cold. The MO group had low Fat-Free Mass (FFM) and high BF. RMR of the MO group was significantly lower than that of the C group. The MO group tended to have poor exercise habits, more dieting (restricting calorie intake) experiences and consumed a diet with less vegetables and beans. We concluded that the prevalence of MO was 32%; it was the highest in winter for subjects who had high fat and low FFM. This fact may be due to poor exercise, more dieting experiences and insufficient intake of vegetables and beans. Furthermore, this accumulation of body fat may be partly due to low RMR

    Contact-number-driven virus evolution : a multi-level modeling framework for the evolution of acute or persistent RNA virus infection

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    Viruses evolve in infected host populations, and host population dynamics affect viral evolution. RNA viruses with a short duration of infection and a high peak viral load, such as SARS-CoV-2, are maintained in human populations. By contrast, RNA viruses characterized by a long infection duration and a low peak viral load (e.g., borna disease virus) can be maintained in nonhuman populations, and the process of the evolution of persistent viruses has rarely been explored. Here, using a multi-level modeling approach including both individual-level virus infection dynamics and population-scale transmission, we consider virus evolution based on the host environment, specifically, the effect of the contact history of infected hosts. We found that, with a highly dense contact history, viruses with a high virus production rate but low accuracy are likely to be optimal, resulting in a short infectious period with a high peak viral load. In contrast, with a low-density contact history, viral evolution is toward low virus production but high accuracy, resulting in long infection durations with low peak viral load. Our study sheds light on the origin of persistent viruses and why acute viral infections but not persistent virus infection tends to prevail in human society

    Local Recurrence of Hepatocellular Carcinoma after Segmental Transarterial Chemoembolization: Risk Estimates Based on Multiple Prognostic Factors

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    OBJECTIVE: To determine the prognostic factors for local recurrence of nodular hepatocellular carcinoma after segmental transarterial chemoembolization. MATERIALS AND METHODS: Seventy-four nodular hepatocellular carcinoma tumors < or = 5 cm were retrospectively analyzed for local recurrence after segmental transarterial chemoembolization using follow-up CT images (median follow-up of 17 months, 4-77 months in range). The tumors were divided into four groups (IA, IB, IIA, and IIB) according to whether the one-month follow-up CT imaging, after segmental transarterial chemoembolization, showed homogeneous (Group I) or inhomogeneous (Group II) iodized oil accumulation, or whether the tumors were located within the liver segment (Group A) or in a segmental border zone (Group B). Comparison of tumor characteristics between Group IA and the other three groups was performed using the chi-square test. Local recurrence rates were compared among the groups using the Kaplan-Meier estimation and log rank test. RESULTS: Local tumor recurrence occurred in 19 hepatocellular carcinoma tumors (25.7%). There were: 28, 18, 17, and 11 tumors in Group IA, IB, IIA, and IIB, respectively. One of 28 (3.6%) tumors in Group IA, and 18 of 46 (39.1%) tumors in the other three groups showed local recurrence. Comparisons between Group IA and the other three groups showed that the tumor characteristics were similar. One-, two-, and three-year estimated local recurrence rates in Group IA were 0%, 11.1%, and 11.1%, respectively. The difference between Group IA and the other three groups was statistically significant (p = 0.000). CONCLUSION: An acceptably low rate of local recurrence was observed for small or intermediate nodular tumors located within the liver segment with homogeneous iodized oil accumulation

    Trends in hepatocellular carcinoma incident cases in Japan between 1996 and 2019

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    We examined the epidemiological trends, including the distribution of sex, age, and disease etiology, in HCC incident cases, over 24 years. Data of 20,547 HCC patients (1996–2019) were analyzed in this prospective study. We divided the study period into four 6-yearly quarters. HCC etiology was categorized as hepatitis B virus (HBV) infection, HBV + hepatitis C virus (HCV) infection, HCV infection, and both negative (non-BC). The incident cases of HCC per quarter of the study period were 4311 (21.0%), 5505 (26.8%), 5776 (28.1%), and 4955 (24.1%), sequentially. Overall, 14,020 (68.2%) patients were male. The number of HCC cases in patients < 60 years, 60–69 years, 70–79 years, and ≥ 80 years were 3711 (18.1%), 6652 (32.4%), 7448 (36.2%), and 2736 (13.3%), respectively. The average age of newly-diagnosed patients increased in each quarter. HCC was associated with HBV, HBV + HCV, and HCV infections and non-BC in 2997 (14.6%), 187 (0.9%), and 12,019 (58.5%), and 5344 (26.0%) cases, respectively. The number of HCV-associated cases decreased in each quarter, while that of non-BC-associated cases increased. HCC incident cases tend to increase in the elderly and in non-BC patients; in contrast, HCC incident cases due to HCV tend to decrease
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