Determination of Real-Time Efflux Phenotypes in Escherichia coli AcrB Binding Pocket Phenylalanine Mutants Using a 1,2′-Dinaphthylamine Efflux Assay

To evaluate the importance of phenylalanine residues for substrate transport in the Escherichia coli efflux pump protein AcrB, we subjected Phe-to-Ala binding pocket mutants to a real-time efflux assay with the novel near-infrared lipophilic membrane probe 1,2′-dinaphthylamine (1,2′-DNA). All mutations, with the exception of F617A, led to considerable retardation of efflux. F610A was the point mutation with the most pronounced impact, followed by F628A, F615A, F136A, and F178A. This is the first study to demonstrate the importance of single phenylalanine residues within the AcrB binding pocket for real-time substrate transport

Analysis of genetic relationships between various populations of domestic and jungle fowl using microsatellite markers [Анализ генетического родства между различными популяциями домашних и диких джунглиевых (банкивских) кур с использованием микросателлитных маркеров. (Украина. ФРГ)]

The genomes of domestic and jungle fowl populations maintained in Ukraine and Germany were screened using microsatellites as molecular markers. Genetic variation and genetic distances between strains of different origins and performance potentials were determined. In total, 224 individuals of 20 populations were genotyped for 14 microsatellite markers covering 11 linkage groups. Of the 14 microsatellite loci, the number of alleles ranged between 2 and 21 per locus, the mean number of alleles being 11.2 per locus. By using Nei's standard distance and the Neighbor-Joining method, a phylogenetic tree was reconstructed; its topology reflected general patterns of relatedness and genetic differentiation among the chicken populations studied. Three major phylogenetic tree groupings were found. The red jungle fowl (Gallus gallus) formed a separate branch and demonstrated a specific allele distribution when compared with domestic fowl breeds analyzed. The second branch comprised commercial layer lines and chicken breeds that were subject to intense selection in the past or had common ancestral breeds with commercial strains. The third group encompassed the German native breed populations. The information about population and breed genetic relationships estimated by microsatellite analysis may be useful as an initial guide in defining objectives for designing future investigations of genetic variation and developing conservation strategies

The role of self-efficacy in the outcome of physiotherapy for urinary incontinence

PURPOSE: Perceived self-efficacy (S-E) (belief in one's ability to perform a behaviour) is a powerful mediator of health behaviours and outcomes in many areas (Bukelew et al 1996; Hellman 1997; Kores et al 1990; Rejeski et al, 1998). Physiotherapy for incontinence follows a self-management approach but evidence of the role of S-E is limited and conflicting. This study examined i) whether perceptions of S-E are related to outcome and ii) whether S-E beliefs change during treatment.RELEVANCE:Urinary incontinence is a common condition with adverse psychosocial consequences. Physiotherapy, including pelvic floor exercises and bladder training, is advocated as a first-line management. Understanding the role of S-E in physiotherapy outcome may enable therapists to modify treatment to enhance S-E and maximise success.SUBJECTS: 26 women (mean age 48.8 years) with stress and mixed urinary incontinence (median duration 4.75 years) referred to physiotherapy were recruited.METHODS AND MATERIALS: S-E was measured before and after treatment using the validated Generalised Self Efficacy Scale and the Incontinence Self-Efficacy and Outcome Expectancy Questionnaire, designed for the study. Physiotherapy outcome was determined after 6 weeks of self-management using validated measures (i.e. Digital Vaginal Assessment, the Symptom Severity Index, and the Kings Health Questionnaire) and compared to baseline measurements.ANALYSES: The analyses were conducted using SPSS. As the data were non-parametric and the sample size was small, Spearman's Rho was used to test associations between baseline self-efficacy and improvement in outcome measures and Wilcoxon's signed rank test was applied to changes in S-E scores.RESULTS: Incontinence improvement was noted for all measures. Significant correlations were found between improvement in muscle grade and initial pelvic floor self-efficacy (p= .03 r=.43) and outcome expectancy (p=.01 r= .54) and between improvement in symptom severity and generalised self-efficacy (p=.03 r=.42). No change in generalised self efficacy was seen during treatment (p=.60 z=-.53) but there were significant reductions in pelvic floor exercise self-efficacy (p=.020 z=-2.32) and outcome expectancy (p=.012 z=-2.52). Cautious interpretation is required however, because of multiple testing.CONCLUSIONS: Women with greater initial beliefs in their general coping abilities and ability to perform pelvic floor exercises experienced the greatest symptomatic improvement after 6 weeks physiotherapy. However, after 6 weeks treatment, women were significantly less positive about their ability to perform the exercises and the likely effectiveness of treatment. The findings suggest that current strategies may be failing to help patients maintain self-efficacy and a positive approach to outcome, which may adversely affect their maintenance of the exercise regime over a longer period

A multicentric validation study of a novel home sleep apnea test based on peripheral arterial tonometry

Study Objectives This paper reports on the multicentric validation of a novel FDA-cleared home sleep apnea test based on peripheral arterial tonometry (PAT HSAT). Methods One hundred sixty-seven participants suspected of having obstructive sleep apnea (OSA) were included in a multicentric cohort. All patients underwent simultaneous polysomnography (PSG) and PAT HSAT, and all PSG data were independently double scored using both the recommended 1A rule for hypopnea, requiring a 3% desaturation or arousal (3% Rule), and the acceptable 1B rule for hypopnea, requiring a 4% desaturation (4% Rule). The double-scoring of PSG enabled a comparison of the agreement between PAT HSAT and PSG to the inter-rater agreement of PSG. Clinical endpoint parameters were selected to evaluate the device’s ability to determine the OSA severity category. Finally, a correction for near-boundary apnea–hypopnea index values was proposed to adequately handle the inter-rater variability of the PSG benchmark. Results For both the 3% and the 4% Rules, most endpoint parameters showed a close agreement with PSG. The 4-way OSA severity categorization accuracy of PAT HSAT was strong, but nevertheless lower than the inter-rater agreement of PSG (70% vs 77% for the 3% Rule and 78% vs 81% for the 4% Rule). Conclusions This paper reported on a multitude of robust endpoint parameters, in particular OSA severity categorization accuracies, while also benchmarking clinical performances against double-scored PSG. This study demonstrated strong agreement of PAT HSAT with PSG. The results of this study also suggest that different brands of PAT HSAT may have distinct clinical performance characteristics