84 research outputs found
Duration of shedding of respiratory syncytial virus in a community study of Kenyan children
Background: Our understanding of the transmission dynamics of respiratory syncytial virus (RSV) infection will be better informed with improved data on the patterns of shedding in cases not limited only to hospital admissions.
Methods: In a household study, children testing RSV positive by direct immunofluorescent antibody test (DFA) were enrolled. Nasal washings were scheduled right away, then every three days until day 14, every 7 days until day 28 and every 2 weeks until a maximum of 16 weeks, or until the first DFA negative RSV specimen. The relationship between host factors, illness severity and viral shedding was investigated using Cox regression methods.
Results: From 151 families a total of 193 children were enrolled with a median age of 21 months (range 1-164 months), 10% infants and 46% male. The rate of recovery from infection was 0.22/person/day (95% CI 0.19-0.25) equivalent to a mean duration of shedding of 4.5 days (95%CI 4.0-5.3), with a median duration of shedding of 4 days (IQR 2-6, range 1-14). Children with a history of RSV infection had a 40% increased rate of recovery i.e. shorter duration of viral shedding (hazard ratio 1.4, 95% CI 1.01-1.86). The rate of cessation of shedding did not differ significantly between males and females, by severity of infection or by age.
Conclusion: We provide evidence of a relationship between the duration of shedding and history of infection, which may have a bearing on the relative role of primary versus re-infections in RSV transmission in the community
NF90 Binds the Dengue Virus RNA 3âČ Terminus and is a Positive Regulator of Dengue Virus Replication
Background
Viral RNA translation and replication are regulated by sequence and structural elements in the 5âČ and 3âČ untranslated regions (UTR) and by host cell and/or viral proteins that bind them. Dengue virus has a single-stranded RNA genome with positive polarity, a 5âČ m7GpppG cap, and a conserved 3âČ-terminal stem loop (SL) that is linked to proposed functions in viral RNA transcription and translation. Mechanisms explaining the contributions of host proteins to viral RNA translation and replication are poorly defined, yet understanding host protein-viral RNA interactions may identify new targets for therapeutic intervention. This study was directed at identifying functionally significant host proteins that bind the conserved dengue virus RNA 3âČ terminus.
Methodology/Principal Findings
Proteins eluted from a dengue 3âČ SL RNA affinity column at increasing ionic strength included two with double-strand RNA binding motifs (NF90/DRBP76 and DEAH box polypeptide 9/RNA helicase A (RHA)), in addition to NF45, which forms a heterodimer with NF90. Although detectable NF90 and RHA proteins localized to the nucleus of uninfected cells, immunofluorescence revealed cytoplasmic NF90 in dengue virus-infected cells, leading us to hypothesize that NF90 has a functional role(s) in dengue infections. Cells depleted of NF90 were used to quantify viral RNA transcript levels and production of infectious dengue virus. NF90 depletion was accompanied by a 50%-70% decrease in dengue RNA levels and in production of infectious viral progeny.
Conclusions/Significance
The results indicate that NF90 interacts with the 3âČ SL structure of the dengue RNA and is a positive regulator of dengue virus replication. NF90 depletion diminished the production of infectious dengue virus by more than 50%, which may have important significance for identifying therapeutic targets to limit a virus that threatens more than a billion people worldwide.Ruth L. Kirschstein National Research Service Award (NIH-NRSA GM64985)UNCF-Merck Postdoctoral FellowshipNational Institute of Allergy and Infectious Diseases (U.S.)Ellison Medical Foundatio
RNA-seq analysis of the gonadal transcriptome during Alligator mississippiensis temperature-dependent sex determination and differentiation
Development and psychometric properties of a belief-based Physical Activity Questionnaire for Diabetic Patients (PAQ-DP)
<p>Abstract</p> <p>Background</p> <p>This study carried out to develop a scale for assessing diabetic patients' perceptions about physical activity and to test its psychometric properties (The Physical Activity Questionnaire for Diabetic Patients-PAQ-DP).</p> <p>Methods</p> <p>An item pool extracted from the Theory of Planned Behavior literature was generated. Then an expert panel evaluated the items by assessing content validity index and content validity ratio. Consequently exploratory factor analysis (EFA) was performed to indicate the scale constructs. In addition reliability analyses including internal consistency and test-retest analysis were carried out.</p> <p>Results</p> <p>In all a sample of 127 women with diabetes participated in the study. Twenty-two items were initially extracted from the literature. A six-factor solution (containing 19 items) emerged as a result of an exploratory factor analysis namely: instrumental attitude, subjective norm, perceived behavioral control, affective attitude, self-identity, and intention explaining 60.30% of the variance observed. Additional analyses indicated satisfactory results for internal consistency (Cronbach's alpha ranging from 0.54 to 0.8) and intraclass correlation coefficients (ranging from 0.40 to 0.92).</p> <p>Conclusions</p> <p>The Physical Activity Questionnaire for Diabetic Patients (PAQ-DP) is the first instrument that applies the Theory of Planned Behavior in its constructs. The findings indicated that the PAQ-DP is a reliable and valid measure for assessing physical activity perceptions and now is available and can be used in future studies.</p
Mood and cognition in healthy older European adults: the Zenith study
YesBackground: The study aim was to determine if state and trait intra-individual measures of everyday affect predict
cognitive functioning in healthy older community dwelling European adults (n = 387), aged 55-87 years.
Methods: Participants were recruited from centres in France, Italy and Northern Ireland. Trait level and variability in
positive and negative affect (PA and NA) were assessed using self-administered PANAS scales, four times a day for
four days. State mood was assessed by one PANAS scale prior to assessment of recognition memory, spatial working
memory, reaction time and sustained attention using the CANTAB computerized test battery.
Results: A series of hierarchical regression analyses were carried out, one for each measure of cognitive function as the
dependent variable, and socio-demographic variables (age, sex and social class), state and trait mood measures as the
predictors. State PA and NA were both predictive of spatial working memory prior to looking at the contribution of trait
mood. Trait PA and its variability were predictive of sustained attention. In the final step of the regression analyses, trait
PA variability predicted greater sustained attention, whereas state NA predicted fewer spatial working memory errors,
accounting for a very small percentage of the variance (1-2%) in the respective tests.
Conclusion: Moods, by and large, have a small transient effect on cognition in this older sample
Mood and the Market: Can Press Reports of Investorsâ Mood Predict Stock Prices?
We examined whether press reports on the collective mood of investors can predict changes in stock prices. We collected data on the use of emotion words in newspaper reports on tradersâ affect, coded these emotion words according to their location on an affective circumplex in terms of pleasantness and activation level, and created indices of collective mood for each trading day. Then, by using time series analyses, we examined whether these mood indices, depicting investorsâ emotion on a given trading day, could predict the next dayâs opening price of the stock market. The strongest findings showed that activated pleasant mood predicted increases in NASDAQ prices, while activated unpleasant mood predicted decreases in NASDAQ prices. We conclude that both valence and activation levels of collective mood are important in predicting trend continuation in stock prices
Nicotinic acetylcholine receptors in attention circuitry: the role of layer VI neurons of prefrontal cortex
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