376 research outputs found

    Rhesus TRIM5α disrupts the HIV-1 capsid at the inter-hexamer interfaces

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    TRIM proteins play important roles in the innate immune defense against retroviral infection, including human immunodeficiency virus type-1 (HIV-1). Rhesus macaque TRIM5α (TRIM5αrh) targets the HIV-1 capsid and blocks infection at an early post-entry stage, prior to reverse transcription. Studies have shown that binding of TRIM5α to the assembled capsid is essential for restriction and requires the coiled-coil and B30.2/SPRY domains, but the molecular mechanism of restriction is not fully understood. In this study, we investigated, by cryoEM combined with mutagenesis and chemical cross-linking, the direct interactions between HIV-1 capsid protein (CA) assemblies and purified TRIM5αrh containing coiled-coil and SPRY domains (CC-SPRYrh). Concentration-dependent binding of CC-SPRYrh to CA assemblies was observed, while under equivalent conditions the human protein did not bind. Importantly, CC-SPRYrh, but not its human counterpart, disrupted CA tubes in a non-random fashion, releasing fragments of protofilaments consisting of CA hexamers without dissociation into monomers. Furthermore, such structural destruction was prevented by inter-hexamer crosslinking using P207C/T216C mutant CA with disulfide bonds at the CTD-CTD trimer interface of capsid assemblies, but not by intra-hexamer crosslinking via A14C/E45C at the NTD-NTD interface. The same disruption effect by TRIM5αrh on the inter-hexamer interfaces also occurred with purified intact HIV-1 cores. These results provide insights concerning how TRIM5α disrupts the virion core and demonstrate that structural damage of the viral capsid by TRIM5α is likely one of the important components of the mechanism of TRIM5α-mediated HIV-1 restriction. © 2011 Zhao et al

    Multidimensional sexual perfectionism and female sexual function: A longitudinal investigation

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    Research on multidimensional sexual perfectionism differentiates four forms of sexual perfectionism: self-oriented, partner-oriented, partner-prescribed, and socially prescribed. Self-oriented sexual perfectionism reflects perfectionistic standards people apply to themselves as sexual partners; partner-oriented sexual perfectionism reflects perfectionistic standards people apply to their sexual partner; partner-prescribed sexual perfectionism reflects people’s beliefs that their sexual partner imposes perfectionistic standards on them; and socially prescribed sexual perfectionism reflects people’s beliefs that society imposes such standards on them. Previous studies found partner-prescribed and socially prescribed sexual perfectionism to be maladaptive forms of sexual perfectionism associated with a negative sexual self-concept and problematic sexual behaviors, but only examined cross-sectional relationships. The present article presents the first longitudinal study examining whether multidimensional sexual perfectionism predicts changes in sexual self-concept and sexual function over time. A total of 366 women aged 17-69 years completed measures of multidimensional sexual perfectionism, sexual esteem, sexual anxiety, sexual problem self-blame, and female sexual function (cross-sectional data). Three to six months later, 164 of the women completed the same measures again (longitudinal data). Across analyses, partner-prescribed sexual perfectionism emerged as the most maladaptive form of sexual perfectionism. In the cross-sectional data, partner-prescribed sexual perfectionism showed positive relationships with sexual anxiety, sexual problem self-blame, and intercourse pain and negative relationships with sexual esteem, desire, arousal, lubrication, and orgasmic function. In the longitudinal data, partner-prescribed sexual perfectionism predicted increases in sexual anxiety and decreases in sexual esteem, arousal, and lubrication over time. The findings suggest that partner-prescribed sexual perfectionism contributes to women’s negative sexual self-concept and female sexual dysfunction

    Development time and new product sales: A contingency analysis of product innovativeness and price

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    Opposing theories and conflicting empirical results with regard to the effect of development time on new product sales suggest the need for a contingency analysis into factors affecting this relationship. This study uses a unique combination of accounting and perceptual data from 129 product development projects to test the combined contingency effect of product innovativeness and new product price on the relationship between development time and new product sales. The results show that for radically new products with short development times, price has no effect on new product sales. When the development time is long, price has a negative effect on the sales of radical new products. The findings additionally show that price has no effect on sales for incremental new products with short development times and a negative effect for incremental new products with long development times. Together, these findings shed new light on the relationship between development time and new product sales

    Illness Schema Activation and the Effects of Illness Seasonality on Accessibility of Implicit Illness-Related Information

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    The Common-Sense Model (CSM) of illness self-regulation is a leading theoretical framework describing the process by which an individual recognizes that he or she is physically ill and subsequently attempts to manage that illness state. The CSM proposes that people possess schematically organized implicit cognitive representations of health threats comprising information about illness such as symptoms, causes, label, duration, consequences, and procedures for managing threat [1, 2, 3, 4]. The proposed function of these stored knowledge structures is to activate a self-regulation process that might protect or restore a state of well-being [5]. The CSM proposes that the schematic representation is centrally activated by detection of deviations from the normal functioning self (i.e., experienced symptoms). The identification of illness and the initiation of self-management attempts follow from the search for illness-relevant cognitive structures and the matching of the content of illness schema to the symptomatic experience. For example, a headache (a symptomatic deviation from normal somatic experience) might activate illness schemata containing the cognitive representation of “headache” such as “hangover,” “dehydration,” or “flu.” The matching of the symptom to a particular illness schema will follow from the search and match to other aspects of plausible illness representations, such as its probable cause or duration (timeline).Full Tex

    High frequencies of elevated alkaline phosphatase activity and rickets exist in extremely low birth weight infants despite current nutritional support

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    <p>Abstract</p> <p>Background</p> <p>Osteopenia and rickets are common among extremely low birth weight infants (ELBW, <1000 g birth weight) despite current practices of vitamin and mineral supplementation. Few data are available evaluating the usual course of markers of mineral status in this population. Our objectives in this study were to determine the relationship between birth weight (BW) and peak serum alkaline phosphatase activity (P-APA) in ELBW infants and evaluate our experience with the diagnosis of rickets in these infants.</p> <p>Methods</p> <p>We evaluated all ELBW infants admitted to Texas Children's Hospital NICU in 2006 and 2007. Of 211 admissions, we excluded 98 patients who were admitted at >30 days of age or did not survive/stay for >6 weeks. Bone radiographs obtained in 32 infants were reviewed by a radiologist masked to laboratory values.</p> <p>Results</p> <p>In this cohort of 113 infants, P-APA was found to have a significant inverse relationship with BW, gestational age and serum phosphorus. In paired comparisons, P-APA of infants <600 g (957 ± 346 IU/L, n = 20) and infants 600–800 g (808 ± 323 IU/L, n = 43) were both significantly higher than P-APA of infants 800–1000 g (615 ± 252 IU/L, n = 50), p < 0.01. Thirty-two patients had radiographic evaluation for evidence of rickets, based on P-APA greater than 800 IU/L, parenteral nutrition greater than 3 to 4 weeks, or clinical suspicion. Of these, 18 showed radiologic rickets and 14 showed osteopenia without rickets. Infants with BW <600 g were more likely to have radiologic rickets (10/20 infants) compared to those with BW 600–800 g (6/43 infants) and BW 800–1000 g (2/50 infants), p < 0.01 for each. P-APA was not significantly higher in infants with radiologic rickets (1078 ± 356 IU/L) compared to those without radiologic evidence of rickets (943 ± 346, p = 0.18).</p> <p>Conclusion</p> <p>Elevation of P-APA >600 IU/L was very common in ELBW infants. BW was significantly inversely related to both P-APA and radiologic rickets. No single value of P-APA was related to radiological findings of rickets. Given the very high risk of osteopenia and rickets among ELBW infants, we recommend consideration of early screening and early mineral supplementation, especially among infants <600 g BW.</p

    Assessing the impact of a cleaning programme on environmental hygiene in labour and neonatal wards: an exploratory study in The Gambia.

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    BACKGROUND: Effective surface cleaning in hospitals is crucial to prevent the transmission of pathogens. However, hospitals in low- and middle-income countries face cleaning challenges due to limited resources and inadequate training. METHODS: We assessed the effectiveness of a modified TEACH CLEAN programme for trainers in reducing surface microbiological contamination in the newborn unit of a tertiary referral hospital in The Gambia. We utilised a quasi-experimental design and compared data against those from the labour ward. Direct observations of cleaning practices and key informant interviews were also conducted to clarify the programme's impact. RESULTS: Between July and September 2021 (pre-intervention) and October and December 2021 (post-intervention), weekly surface sampling was performed in the newborn unit and labour ward. The training package was delivered in October 2021, after which their surface microbiological contamination deteriorated in both clinical settings. While some cleaning standards improved, critical aspects such as using fresh cleaning cloths and the one-swipe method did not. Interviews with senior departmental and hospital management staff revealed ongoing challenges in the health system that hindered the ability to improve cleaning practices, including COVID-19, understaffing, disruptions to water supply and shortages of cleaning materials. CONCLUSIONS: Keeping a hospital clean is fundamental to good care, but training hospital cleaning staff in this low-income country neonatal unit failed to reduce surface contamination levels. Further qualitative investigation revealed multiple external factors that challenged any possible impact of the cleaning programme. Further work is needed to address barriers to hospital cleaning in low-income hospitals

    Declining Sleep Quality among Nurses: A Population-Based Four-Year Longitudinal Study on the Transition from Nursing Education to Working Life

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    Background: Several studies have established impaired sleep is a common problem among nurses. Overworked, fatigued and stressed nurses are at a higher risk of making mistakes that threaten patient safety as well as their own health. The aim of the present study was to longitudinally monitor the development of sleep quality in nurses, starting from the last semester at the university, with three subsequent annual follow-ups once the nurses had entered working life. Methodology/Principal Findings: Nationwide, longitudinal questionnaire study of nursing students and newly qualified nurses in Sweden. The results imply a continuous decline in sleep quality among nurses during the three years of follow-up, starting from their last semester of nursing education and continuing for three years into their working life. The most pronounced short-term decline in sleep quality seems to occur in the transition between student life and working life. Conclusion/Significance: This finding is important since it may affect the quality of care and the health of nurses negatively
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