RESUMO
Human adenovirus (HAdV) types F40 and F41 are a prominent cause of diarrhea and diarrhea-associated mortality in young children worldwide. These enteric HAdVs differ notably in tissue tropism and pathogenicity from respiratory and ocular adenoviruses, but the structural basis for this divergence has been unknown. Here, we present the first structure of an enteric HAdV-HAdV-F41-determined by cryo-electron microscopy to a resolution of 3.8 Å. The structure reveals extensive alterations to the virion exterior as compared to nonenteric HAdVs, including a unique arrangement of capsid protein IX. The structure also provides new insights into conserved aspects of HAdV architecture such as a proposed location of core protein V, which links the viral DNA to the capsid, and assembly-induced conformational changes in the penton base protein. Our findings provide the structural basis for adaptation of enteric HAdVs to a fundamentally different tissue tropism.
RESUMO
BACKGROUND: Tobacco-free campus policy is identified as an effective means to address tobacco use on college campuses; however, the prevalence of tobacco-free policies (TFPs) in the United States remains low. This study explores college tobacco users' support for a university's TFP and tobacco-free campuses (TFCs) in general. METHODS: A standardized and structured questionnaire was administered to 790 college tobacco users recruited in a university located in a tobacco-growing region of the United States, during April-May 2011, to collect information on support for TFPs and TFCs and sociodemographic-political characteristics. Descriptive and multivariable logistic regression analyses were conducted to identify key factors associated with support for TFPs and TFCs. RESULTS: Approximately 2 of 5 tobacco users favored TFPs and TFCs. Multivariable logistic regression models showed that demographic factors were mostly not significantly associated with attitudes of the college tobacco users. Instead, while knowledge about harmful effects of exposure to secondhand tobacco smoke significantly increased support for both TFPs and TFCs, parental and peer smoking and exposure to tobacco industry promotions significantly decreased the likelihoods of support compared with respective referent groups. CONCLUSION: Study findings suggest that campus advocacy and education campaigns for campus tobacco policies to pay attention to tobacco use behavior of familial relations, tobacco industry activities, and other political determinants of tobacco users' attitudes. Thus, this study should inform national initiatives to promote TFPs nationwide such as the Tobacco-Free College Campus Initiative.
