401 research outputs found

    Fatal Sindbis Virus Infection of Neonatal Mice in the Absence of Encephalitis

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    A comparative pathogenesis study was performed in neonatal mice using a molecularly cloned laboratory variant of Sindbis strain AR339, designated TRSB, and a single-site attenuated mutant of TRSB derived by site-directed mutagenesis of the E2 glycoprotein from Ser to Arg at residue 114 (TRSBr114). TRSB caused 100% mortality with an average survival time of 3.0 +/- 0.7 days, whereas mice inoculated with TRSBr114 exhibited an attenuated disease course with 46% mortality and an extended average survival time of 7.5 +/- 3.4 days for those animals that died. Reduced virulence of TRSBr114 was characterized by delayed appearance of detectable virus, relative to TRSB, and by lower peak virus titers in both sera and brains of infected mice. TRSB infection induced very high peak serum titers of interferon alpha/beta (215,000 units/ml compared to 2100 units/ml for TRSBr114). In situ hybridization analysis demonstrated replication of TRSB in brain, but only minimal histopathological changes and no evidence of encephalitis were observed. However, extensive extraneural lesions and viral replication were found in skin, connective tissue, and muscle. Moreover, dramatic involution of the thymus and loss of hematopoietic tissues were observed in the absence of virus replication at these sites, suggesting the involvement of a systemic physiological stress response in TRSB infection. TRSBr114 infection did not cause thymic lesions. Otherwise, the attenuated mutant demonstrated a similar pattern of tissue and organ involvement, but lesions and positive in situ hybridization signal were much more limited in scope and intensity compared to TRSB. TRSBr114-infected mice developed myositis and encephalomyelitis approximately 6 days postinfection. Therefore, TRSB-infected animals may succumb to an early syndrome associated with the stress response, preventing their survival for a time sufficient for the development of encephalitis. Alternatively, a systemic stress response, as evidenced by thymic involution, may result in immunosuppression, thus contributing to the absence of encephalitis. In any event, the attenuating mutation in the E2 glycoprotein significantly altered the course of Sindbis-induced disease by limiting virus replication and associated damage early in infection. Mutant-infected animals survived beyond Day 4 and progressed to a classical encephalomyelitis from which about half recovered

    TNFα, Interferon, and Stress Response Induction as a Function of Age-Related Susceptibility to Fatal Sindbis Virus Infection of Mice

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    AbstractThe age-related acquisition of resistance to fatal Sindbis virus infection was examined using a molecularly cloned laboratory strain of the AR339 isolate designated TRSB. TRSB caused 100% mortality in mice up to 5 days of age. Resistance to fatal infection developed abruptly between 5 and 9 days of age. Lethal Sindbis virus infection of mice inoculated at 4 days of age was characterized by high levels of virus replication, induction of high levels of interferon-α/β and TNF-α and severe thymic involution indicative of a systemic stress response. These changes correlated with predominantly noninflammatory lesions. In contrast, TRSB infection of older mice was characterized by survival, more limited virus replication, reduced cytokine induction, and the development of inflammatory responses leading to encephalitis, myositis, and myocarditis. Previous studies utilized infections of neonatal mice with TRSB and an attenuated mutant of TRSB to compare fatal and nonfatal Sindbis infection (Trgovcich et al., 1996. Virology 224, 73–83). The experiments reported here utilize mouse age at the time of infection to create conditions for examination of fatal and nonfatal TRSB infections. Both experiments suggest that fatal infection is associated with a shock-like syndrome and little or no inflammatory pathology, while survival is correlated with greatly reduced cytokine levels and inflammatory lesions

    Identifying Culturally Appropriate Strategies for Educating a Mexican Immigrant Community about Lead Poisoning Prevention

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    Lead paint is one source of exposure for lead poisoning; however, recent Latino and other immigrant populations are also at risk of exposure through ceramic cooking pots with lead glaze, some imported candies, and certain stomach ailment home remedies. Public health agencies and practitioners acknowledge that Latino families should be educated about lead poisoning prevention but report barriers to conducting outreach and education in Latino communities. This study reports findings from focus groups and interviews with the local Latino immigrant community and professionals on (1) current knowledge and beliefs about lead poisoning and (2) recommendations of culturally appropriate educational strategies

    Views on exercise and physical activity among rural-dwelling senior citizens

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    Context: This study was conducted with senior citizens in the 2 rural communities of Ada and Lindsay, Oklahoma. These communities are both predominantly white, with the largest minority population being American Indian. Both communities are more than 60 miles from a metropolitan area and have a history of farming and ranching. Purpose: The purpose of this study was to explore contextual factors related to physical activity among senior citizens living in rural communities. Methods: Two focus groups were conducted. The groups were conducted in mixed-sex sessions and were audiotaped and transcribed verbatim for the purpose of analysis. Findings: Themes from the focus groups included the following: (1) the types of daily activities engaged in by seniors; (2) the meaning and connotation of the words exercise and physical activity, with physical activity connoting for some the negative imagery of physical labor; and (3) the availability and suitability of settings for physical activity. For seniors living in rural settings in Oklahoma, the lack of indoor facilities and the sometimes extreme climatic conditions serve as significant barriers to physical activity. Conclusion: This study suggests that programs seeking to encourage physical activity among seniors in rural areas could benefit from an assessment of resources and settings for physical activity and the avoidance of language that may have negative connotations for this population

    Achieving a “Broad View of Health”: Findings From the California Healthy Cities and Communities Evaluation

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    Promoting a “broad view of health” is an important objective of the healthy cities movement, including recognition of the powerful role that social relations and living conditions play in the health of community members. This article presents a quantitative approach to assessing consensus and change in ideas about health determinants among local coalition members. A ranking of five determinants of health in the form of paired comparisons was included in a survey of coalition members of 20 local healthy communities projects in California. Findings revealed conflicting views among members in the planning year, with some respon-dents emphasizing the role of social factors and living conditions and others emphasizing the role of health care and lifestyle decisions. Data collected at the end of the funded intervention showed movement toward a broader view of health, with greater consensus on this view in select communities

    PSOC in community context: multi-level correlates of a measure of psychological sense of community in low-income, urban neighborhoods

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    Recent years have seen a steady increase in attention to communities as a source of both risk and protective factors for various individual outcomes. Psychological sense of community (PSOC) is one concept which can be important in describing the ways in which real and perceived aspects of community might mediate both individual and community outcomes. To understand the setting-specific interaction of individual and community, it is necessary to examine how individual and community level factors are simultaneously associated with psychological sense of community. As part of a larger study of community influence on health, we conducted a random household survey in three geographically defined low-income communities in Baltimore City. Nine hundred fourteen individuals were surveyed with a questionnaire that included a measure of psychological sense of community. This article describes the variability of PSOC in these communities and identifies individual- and community-level characteristics associated with varying levels of PSOC. Statistical methods of multi-level analysis were employed. Individuals in low-income communities showed heterogeneity for PSOC that is partially explained by variation in individual- and community-level characteristics. We suggest that this variability, as well as the promotion of positive PSOC within low-income communities, has implications for the development and implementation of community-based interventions

    What do men who serve as lay health advisors really do? Immigrant Latino men share their experiences as Navegantes to prevent HIV.

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    HoMBReS was a lay health adviser (LHA) intervention designed to reduce sexual risk among recently arrived, nonEnglish-speaking Latino men who were members of a multicounty soccer league in central NC. Our community- based participatory research (CBPR) partnership collected, analyzed, and interpreted qualitative life-story narratives to characterize the roles of male LHAs known as Navegantes. Nine Navegantes were interviewed. Their mean age was 39 years (range: 26-62 years); six were from Mexico and three from El Salvador. Navegantes described the function and facilitators of serving as LHAs and identified leverage points for future HIV and STD prevention strategies. They highlighted psychosocial and sociocultural influences on HIV risk, settings for risky behavior, and personal changes from serving as Navegantes. This study provides preliminary evidence that an LHA approach is feasible and appropriate for Latino men, and can be effective in reaching men who might otherwise be difficult to reach

    Strengthening Community Leadership: Evaluation Findings From the California Healthy Cities and Communities Program

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    Collaborative approaches to community health improvement such as healthy cities and communities have the potential to strengthen community capacity through leadership development. The healthy cities and communities process orients existing local leadership to new community problem-solving strategies and draws out leadership abilities among residents not previously engaged in civic life. In an evaluation of the California Healthy Cities and Communities (CHCC) Program, leadership development was one of several outcomes assessed at the civic-participation level of the social ecology. Data collection methods included focus groups and surveys, semistructured interviews with coordinators and community leaders, and review of program documents. Findings suggest that the CHCC program enhanced capacity by expanding new leadership opportunities through coalition participation, program implementation, and civic leadership roles related to spin-off organizations and broader collaborative structures. Communities in rural regions were particularly successful in achieving significant leadership outcomes
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