159 research outputs found

    Tracing exogenous surfactant in vivo in rabbits by the natural variation of 13C

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    BACKGROUND: Respiratory Distress Syndrome (RDS) is a prematurity-related breathing disorder caused by a quantitative deficiency of pulmonary surfactant. Surfactant replacement therapy is effective for RDS newborns, although treatment failure has been reported. The aim of this study is to trace exogenous surfactant by 13C variation and estimate the amount reaching the lungs at different doses of the drug. METHODS: Forty-four surfactant-depleted rabbits were obtained by serial bronchoalveolar lavages (BALs), that were merged into a pool (BAL pool) for each animal. Rabbits were in nasal continuous positive airway pressure and treated with 0, 25, 50, 100 or 200 mg/kg of poractant alfa by InSurE. After 90 min, rabbits were depleted again and a new pool (BAL end experiment) was collected. Disaturated-phosphatidylcholine (DSPC) was measured by gas chromatography. DSPC-Palmitic acid (PA) 13C/12C was analyzed by isotope ratio mass spectrometry. One-way non-parametric ANOVA and post-hoc Dunn's multiple comparison were used to assess differences among experimental groups. RESULTS: Based on DSPC-PA 13C/12C in BAL pool and BAL end experiment, the estimated amount of exogenous surfactant ranged from 61 to 87% in dose-dependent way (p < 0.0001) in animals treated with 25 up to 200 mg/kg. Surfactant administration stimulated endogenous surfactant secretion. The percentage of drug recovered from lungs did not depend on the administered dose and accounted for 31% [24-40] of dose. CONCLUSIONS: We reported a risk-free method to trace exogenous surfactant in vivo. It could be a valuable tool for assessing, alongside the physiological response, the delivery efficiency of surfactant administration techniques

    Systematic review and meta-analysis of the diagnostic accuracy of ultrasonography for deep vein thrombosis

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    Background Ultrasound (US) has largely replaced contrast venography as the definitive diagnostic test for deep vein thrombosis (DVT). We aimed to derive a definitive estimate of the diagnostic accuracy of US for clinically suspected DVT and identify study-level factors that might predict accuracy. Methods We undertook a systematic review, meta-analysis and meta-regression of diagnostic cohort studies that compared US to contrast venography in patients with suspected DVT. We searched Medline, EMBASE, CINAHL, Web of Science, Cochrane Database of Systematic Reviews, Cochrane Controlled Trials Register, Database of Reviews of Effectiveness, the ACP Journal Club, and citation lists (1966 to April 2004). Random effects meta-analysis was used to derive pooled estimates of sensitivity and specificity. Random effects meta-regression was used to identify study-level covariates that predicted diagnostic performance. Results We identified 100 cohorts comparing US to venography in patients with suspected DVT. Overall sensitivity for proximal DVT (95% confidence interval) was 94.2% (93.2 to 95.0), for distal DVT was 63.5% (59.8 to 67.0), and specificity was 93.8% (93.1 to 94.4). Duplex US had pooled sensitivity of 96.5% (95.1 to 97.6) for proximal DVT, 71.2% (64.6 to 77.2) for distal DVT and specificity of 94.0% (92.8 to 95.1). Triplex US had pooled sensitivity of 96.4% (94.4 to 97.1%) for proximal DVT, 75.2% (67.7 to 81.6) for distal DVT and specificity of 94.3% (92.5 to 95.8). Compression US alone had pooled sensitivity of 93.8 % (92.0 to 95.3%) for proximal DVT, 56.8% (49.0 to 66.4) for distal DVT and specificity of 97.8% (97.0 to 98.4). Sensitivity was higher in more recently published studies and in cohorts with higher prevalence of DVT and more proximal DVT, and was lower in cohorts that reported interpretation by a radiologist. Specificity was higher in cohorts that excluded patients with previous DVT. No studies were identified that compared repeat US to venography in all patients. Repeat US appears to have a positive yield of 1.3%, with 89% of these being confirmed by venography. Conclusion Combined colour-doppler US techniques have optimal sensitivity, while compression US has optimal specificity for DVT. However, all estimates are subject to substantial unexplained heterogeneity. The role of repeat scanning is very uncertain and based upon limited data

    Accommodating to English-medium instruction in teacher education in Finland

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    This study analyses teacher educators’ and student teachers’ perceptions of teaching and learning situations in an international English as a lingua franca (ELF) context in an English-medium instruction (EMI) teacher education programme in Finland. The analysis of semi-structured interviews revealed that the participants perceived a partial reversal of traditional teacher and student roles; students assisted voluntarily and teaching became reciprocal. Some teachers reflected on having used typical strategies in ELF context such as code-switching to further communication and engage students. However, teachers’ lack of fluency was sometimes considered causing frustration among students and affected negatively their feeling of being professional teacher educators. Nevertheless, by increasing more learner-led activities, ELF can positively affect teacher education pedagogy.Peer reviewe

    Validation of a Tool to Evaluate Drug Prevention Programs Among Students

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    Background: School-based prevention programs have been implemented worldwide with the intention of reducing or delaying the onset of alcohol and drug use among adolescents. However, their effects need to be evaluated, being essential to use validated and reliable questionnaires for this purpose. This study aimed to verify the semantic validity and reliability of an instrument developed to evaluate the results of a government drug prevention program for schoolchildren called #Tamojunto2.0.Methods: This is a mixed methods study with quantitative (test-retest, confirmatory factor analysis and non-response evaluation) and qualitative analyses (focus group and field cards). The self-administered questionnaires were used for a sample of 262 eighth-grade students (elementary school II) in 11 classes of four public schools in the city of São Paulo.Results: The level of agreement was substantial (Kappa 0.60–0.79) or almost perfect (Kappa &gt; 0.8) for almost all questions about the use of marijuana, alcohol, cigarettes, cocaine, crack, and binge drinking. The model fit indices, for almost all secondary outcomes, indicated that the modls underlying each scale, constituted by observed and latent variables, had a good fit adjustument. The focus groups and field cards provided high-quality information that helped the researchers identify the main difficulties in applying and understanding the questions.Conclusion: The questionnaire showed high factorial validity, reliability and understanding by adolescents. After the necessary changes, identified in this study, the questionnaire will be suitable to evaluate the results of the #Tamojunto2.0 program in a randomized controlled trial

    Personality Traits of an Entrepreneur, Determinants of Successful Microenterprise in Ireland

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    Why do certain individuals become entrepreneur and are successful, whereas others do not? The researchers in the entrepreneurship field attempt to answer that question by studying the personality traits of entrepreneurs for decades. Many confirm that the personality traits have a positive correlation with entrepreneurial intention and performance. Various studies suggest that the main entrepreneurial characteristics are risk attitudes, need for achievement, internal locus of control, innovativeness, and self-efficacy. However, debate exist if the personality traits are born or inherited and if the entrepreneurs’ actions are influenced by factors such as family, culture, education and market conditions. Although these aspects will be reviewed the focus of this study is on entrepreneurs’ personality traits only. Consequently, the aim of this study is to identify which of the personality traits, and whether there are traits, that are associated with operating successful microenterprise, from a perspective of an owner-manager of an established business in Ireland. The findings of this research revealed that the participants perceive themselves as individuals who possess indirectly four out of five most cited traits in the literature, which are need for achievement, locus of control, innovativeness and self-efficacy. In addition, they mentioned ability to relate to others, being organized and perform a quality work as the most important characteristics of a successful business owner. Also, other factors of environment influenced the participants’ decision to become an entrepreneur and Ireland was perceived as an attractive country to set up a business. Still, most of the participants do not perceive themselves as a successful entrepreneur. In summary, the inconclusiveness of this study generate more questions than it provide answers, coupled with this study limitations it is suggested that additional and more extensive research is desired

    The German Music@Home: Validation of a questionnaire measuring at home musical exposure and interaction of young children.

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    The present study introduces the German version of the original version of the Music@Home questionnaire developed in the UK, which systematically evaluates musical engagement in the home environment of young children. Two versions are available, an Infant version for children aged three to 23 months and a Preschool version for children aged two to five and a half years. For the present study, the original Music@Home questionnaire was translated from English into German and 656 caregivers completed the questionnaire online. A confirmatory factor analysis showed moderate to high fit indices for both versions, confirming the factor structure of the original questionnaire. Also, the reliability coefficients for the subscales (Parental beliefs, Child engagement with music, Parent initiation of singing, Parent initiation of music-making for the Infant version and Parental beliefs, Child engagement with music, Parent initiation of music behavior and Breadth of musical exposure for the Preschool version) ranged from moderate to high fits. Furthermore, the test-retest analysis (N = 392) revealed high correlations for the general factor and all subscales confirming their internal reliability. Additionally, we included language questionnaires for children of two and three years of age. Results showed that higher scores on the Music@Home questionnaire were moderately associated with better language skills in two-year-olds (N = 118). In sum, the study presents the validated German Music@Home questionnaire, which shows good psychometric properties. The two versions of the questionnaire are available for use in order to assess home musical engagement of young children, which could be of interest in many areas of developmental research
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