Influence of charge on filtration across renal basement membrane films in vitro

AbstractInfluence of charge on filtration across renal basement membrane films in vitro. The filtration of differently charged species of myoglobin and dextran across films of isolated basement membrane in vitro showed that the filtration behavior of both polymers was influenced by charge. Rejection increased with increasing negative charge. Titration of the isolated basement membrane revealed an isoionic point of pH 5.5 and an isoelectric point of pH 5.7. The net negative charge at pH 7.4 was 0.15 mEq/g protein; this charge was attributed to carboxylate anion. Glycosaminoglycan sulphate did not contribute significantly to the net charge. Filtration of narrow range dextran fractions across films of basement membrane at the isoelectric point markedly reduced differences in filtration due to charge confirming that the differences in behavior found at pH 7.4 were due to charge interactions between the solutes and the membranes. Physical characterization of the charged and uncharged dextran fractions revealed no substantial differences in size or shape for the differently charged species.Influence de la charge sur la filtration à travers des films de membrane basale rénale in vitro. La filtration d'espèces différemment chargées de myoglobine et de dextran à travers des films de membrane basale isolée in vitro a montré que le comportement de filtration des deux polymères était influencé par la charge. Le rejet s'élevait lorsque la charge négative augmentait. La titration de la membrane basale isolée a révélé un point isoionique de pH 5,5 et un point isoélectrique de pH 5,7. La charge négative nette à pH 7,4 était de 0,15 mEq/g protéines; cette charge a été attribuée à l'anion carboxylate. Le sulfate de glycosaminoglycan ne contribuait pas significativement à la charge nette. La filtration de fractions d'étendues étroites de dextran à travers des films de membrane basale au point isoélectrique réduisait de façon marquée les différences de filtration dûes à la charge, confirmant que ses différences de comportement trouvées à pH 7,4 étaient dûes à des interactions de charge entre les solutes et les membranes. La caratérisation physique des fractions de dextran chargées ou non n'a pas révélé de différence substantielle dans la taille ou la forme des espèces de charges différentes

Navigating the Boundaries of Youth Violence Prevention and Reduction: Reflections on Power in Community Engaged Scholarship

Community-engaged scholars grapple with power asymmetries in community-university partnerships, generally working from the assumption that deliberate practices are required to moderate the researchers’ power vis-a-vis that of the community. In this article, we suggest that this dyadic framing masks the complexity of power dynamics within communities, of which the university is just one part, and examine how power is negotiated in the boundary zones of a partnership. We use Third Generation Cultural Historical Activity Theory (CHAT) as a conceptual framework to analyse the structural and cultural dimensions of the boundary zone in which research, learning and action in our partnership occurred (Engeström 1996). A brief story sheds light on our boundary work which uses research and data to span, broker and shake institutional boundaries for the purpose of youth violence prevention and intervention. Our analysis illuminates the potential and limitations of our power to foster transformational change. It also allows us to show that underestimating power differentials and the diversity of values and cultures within an organisation and between a university and a community partner, and certainly across multiple institutions in the case of a cross-sector partnership, can slow down and even thwart work to address societal problems

Writing Renewal Retreats: The Scholarly Writer, Contemplative Practice, and Scholarly Productivity

This article offers an exploratory case study of a program for faculty that blends contemplative practices, scholarly productivity, and renewal of faculty as writers at a retreat in a natural setting. We share faculty learning outcomes, logistics, a retreat agenda, and evaluation data from four writing renewal retreats conducted over two years to present initial insight into a contemplative approach to writing retreats that fosters a connection to self, to scholarship, and to a community of writers—key elements of a successful writing life. Through critical reflection on the role of contemplative practices, scholarly productivity, and faculty well-being, we offer a model for holistic faculty development

Glutamine supplementation to prevent morbidity and mortality in preterm infants

BACKGROUND: Glutamine is a conditionally essential amino acid. Endogenous biosynthesis may be insufficient for tissue needs in states of metabolic stress. Evidence exists that glutamine supplementation improves clinical outcomes in critically ill adults. It has been suggested that glutamine supplementation may also benefit preterm infants. OBJECTIVES: To determine the effects of glutamine supplementation on mortality and morbidity in preterm infants. SEARCH METHODS: We used the standard search strategy of the Cochrane Neonatal Review Group. This included searches of the Cochrane Central Register of Controlled Trials (CENTRAL, 2015, Issue 12), MEDLINE, EMBASE and Maternity and Infant Care (to December 2015), conference proceedings and previous reviews. SELECTION CRITERIA: Randomised or quasi-randomised controlled trials that compared glutamine supplementation versus no glutamine supplementation in preterm infants at any time from birth to discharge from hospital. DATA COLLECTION AND ANALYSIS: We extracted data using the standard methods of the Cochrane Neonatal Review Group, with separate evaluation of trial quality and data extraction by two review authors. We synthesised data using a fixed-effect model and reported typical relative risk, typical risk difference and weighted mean difference. MAIN RESULTS: We identified 12 randomised controlled trials in which a total of 2877 preterm infants participated. Six trials assessed enteral glutamine supplementation and six trials assessed parenteral glutamine supplementation. The trials were generally of good methodological quality. Meta-analysis did not find an effect of glutamine supplementation on mortality (typical relative risk 0.97, 95% confidence interval 0.80 to 1.17; risk difference 0.00, 95% confidence interval -0.03 to 0.02) or major neonatal morbidities including the incidence of invasive infection or necrotising enterocolitis. Three trials that assessed neurodevelopmental outcomes in children aged 18 to 24 months and beyond did not find any effects. AUTHORS' CONCLUSIONS: The available trial data do not provide evidence that glutamine supplementation confers important benefits for preterm infants

Wound healing angiogenesis: The clinical implications of a simple mathematical model

Nonhealing wounds are a major burden for health care systems worldwide. In addition, a patient who suffers from this type of wound usually has a reduced quality of life. While the wound healing process is undoubtedly complex, in this paper we develop a deterministic mathematical model, formulated as a system of partial differential equations, that focusses on an important aspect of successful healing: oxygen supply to the wound bed by a combination of diffusion from the surrounding unwounded tissue and delivery from newly formed blood vessels. While the model equations can be solved numerically, the emphasis here is on the use of asymptotic methods to establish conditions under which new blood vessel growth can be initiated and wound-bed angiogenesis can progress. These conditions are given in terms of key model parameters including the rate of oxygen supply and its rate of consumption in the wound. We use our model to discuss the clinical use of treatments such as hyperbaric oxygen therapy, wound bed debridement, and revascularisation therapy that have the potential to initiate healing in chronic, stalled wounds

The Acute Effect of Magnesium Supplementation on Endothelial Function: A randomized cross-over pilot study

: Magnesium (Mg) deficiency might be a catalyst in the process of endothelial dysfunction, an early event in the pathogenesis of atherosclerosis. The aim of this study was to determine the acute effect of an oral Mg supplement as compared to control on endothelial function assessed by flow-mediated dilatation (FMD). Nineteen participants (39 years, body mass index (BMI) 22.9 kg/m2 ) completed this randomized cross-over study. Blood pressure (BP) and FMD were measured and blood samples were taken before participants drank 200 mL water, with or without an over the counter Mg supplement (450 mg and 300 mg for men and women). Measurements were repeated at 60 and 120 min. There was a statistically significant two-way interaction between treatment and time on serum Mg (p = 0.037). A difference of −0.085 mm in FMD was observed 60-min post drink in the control group, as compared to baseline FMD, and no difference was observed in the supplement group as compared to baseline. Despite the non-significant interaction between treatment and time on FMD, once adjusted for baseline, the difference seen in the control group and the lack of change in the supplement group at 60 min post-drink suggests that Mg might attenuate the reduction in FMD post-prandiall

Potential of Raman Spectroscopy For the Analysis of Plasma/serum in the Liquid State: Recent Advances

There is compelling evidence in the literature to support the application of Raman spectroscopy for analysis of bodily fluids in their native liquid state. Naturally, the strategies described in the literature for Raman spectroscopic analysis of liquid samples have advantages and disadvantages. Herein, recent advances in the analysis of plasma/serum in the liquid state are reviewed. The potential advantages of Raman analysis in the liquid form over the commonly employed infrared absorption analysis in the dried droplet form are initially highlighted. Improvements in measurement protocols based on inverted microscopic geometries, clinically adaptable substrates, data preprocessing and analysis, and applications for routine monitoring of patient health as well as therapeutic administration are reviewed. These advances suggest that clinical translation of Raman spectroscopy for rapid biochemical analysis can be a reality. In the future, this method will prove to be highly beneficial to clinicians for rapid screening and monitoring of analytes and drugs in the biological fluids, and to the patients themselves, enabling early treatment, before the disease becomes symptomatic, allowing early recovery

Vocational education for children with disabilities in East Africa: Uwezo

Children with disabilities (CWD) in East Africa experience occupational injustice in its most severe forms. A number of complex and dynamic factors contribute to this injustice including cultural beliefs about disability, a significant gap between policy adaptation and policy implementation, and physical barriers as a result of poverty. Uwezo is the Swahili word for ability, a name suitable for a program created to empower CWD in low-income countries (LIC) and lower-middle income countries (LMIC) to achieve their maximum potential. Uwezo is a community-owned and community-run vocational education program for CWD that will originate in East Africa with the intent to expand globally to serve additional communities in need. Children with disabilities ages 3-16 will learn three categories of classroom and experiential instruction including: education for everyday living, life skills and vocational study. Designed with sustainability as a priority, the program will be presented to community members as a template, intended to be carefully tailored according to the community’s unique priorities and needs. Ultimately, Uwezo has the potential to rapidly shift cultural perception about disability, enhance the local economy, inspire grassroot advocacy efforts, and improve the and quality of life for children and persons with disabilities

Frequency domain characteristics of ground reaction forces during walking of young and elderly females

Objective. To examine the frequency domain characteristics of the ground reaction forces of young and elderly females during free walking. Design. Independent t-tests were used to examine the frequency content of all three components of the ground reaction force. Background. Frequency domain analysis has the potential to assist in identifying changes in gait that may be masked in the time domain. No research has been done to identify changes in gait due to age-related impairments in the frequency domain. Methods. Ten young and ten elderly females walked at a prescribed speed while ground reaction forces were collected via a force platform. The highest frequency required to reconstruct the 99% of the signal’s power in each direction was calculated from the ground reaction forces. Results. The frequency content significantly decreased in the anterior–posterior direction for the young group. No significant differences were found for the other two directions (vertical and mediolateral) between the two groups. The elderly had a significantly higher frequency content compared with the young in the anterior–posterior direction. Conclusions. Ageing differences were detected using the frequency domain analysis for the anterior–posterior direction. It is possible that these differences were the result of the decrease in walking speed associated with the elderly group. Relevance Frequency domain analysis of the ground reaction forces is a useful addition to the gait analyst’s armamentarium especially when such changes are not obvious in the time domain