The role of vitamin D in improving physical performance in the elderly

There is an ongoing debate over the role of serum 25(OH) vitamin D [25(OH)D] levels in maintaining or improving physical performance and muscle strength. Much of the controversy is because of the variability between studies in participants' characteristics, baseline serum 25(OH)D levels, and baseline physical functioning. The aim of this ancillary study conducted within a randomized controlled clinical trial was to investigate whether supplementation with 400 or 2000 IU vitamin D₃ daily for 6 months would improve measures of physical performance and muscle strength in a community‐dwelling elderly population aged 65 to 95 years. Those with the slowest gait speed improved their ability to do chair‐stand tests after vitamin D supplementation. This finding remained significant after controlling for potential confounding variables. There was also an inverse correlation between serum 25(OH)D levels and fat mass index (FMI) among women, suggesting that higher supplementation with vitamin D is needed as weight increases. The results of this study suggest that supplementation with vitamin D may be most beneficial in older populations who have low baseline physical functioning. © 2013 American Society for Bone and Mineral Research.     

Inhibition of NF-kappa B during human dendritic cell differentiation generates anergy and regulatory T-cell activity for one but not two human leukocyte antigen DR mismatches

We examined the in vitro inhibition of human monocyte-derived dendritic cells (DC) maturation via NF-kappaB blockade on T-cell allostimulation, cytokine production, and regulatory T-cell generation. DC were generated from CD14+ monocytes isolated from peripheral blood using GM-CSF and IL-4 for differentiation and TNF-alpha, IL-1beta, and PGE2 as maturational stimuli with or without the NF-kappaB inhibitors, BAY 11-7082 (BAY-DC) or Aspirin (ASA-DC). Stimulator and responder cells were one versus two HLA-DR mismatched in direct versus indirect presentation assays. Both BAY-DC and ASA-DC expressed high levels of HLA-DR and CD86 but always expressed less CD40 compared with controls. Some experiments showed slightly lower levels of CD80. Both BAY- and ASA-allogeneic DC and autologous alloantigen pulsed DC were weaker stimulators of T cells (by MLR) compared with controls, and there was reduced IL-2 and IFN-gamma production by T cells stimulated with BAY-DC or ASA-DC (by ELISPOT) (more marked results were always observed with ASA-treated DC). In addition, NF-kappaB blockade of DC maturation caused the generation of T cells with regulatory function (T regs) but only when T cells were stimulated by either allogeneic (direct presentation) or alloantigen pulsed autologous DC (indirect presentation) with one HLA-DR mismatch and not with two HLA-DR mismatches (either direct or indirect presentation). However, the T regs generated from these ASA-DC showed similar FoxP3 mRNA expression to those from nontreated DC. Extension of this study to human organ transplantation suggests potential therapies using one DR-matched NF-kappaB blocked DC to help generate clinical tolerance.     

Penta-block copolymer microspheres: Impact of polymer characteristics and process parameters on protein release

Here, we aimed to develop protein loaded microspheres (MSs) using penta-block PLGA-based copolymers to obtain sustained and complete protein release. We varied MS morphology and studied the control of protein release. Lysozyme was used as a model protein and MSs were prepared using the solid-in-oil-in-water emulsion solvent extraction method. We synthesized and studied various penta-block PLGA-based copolymers. Copolymer characteristics (LA/GA ratio and molecular weight of PLGA blocks) influenced MS morphology. MS porosity was influenced by process parameters (such as solvent type, polymer concentration, emulsifying speed), whereas the aqueous volume for extraction and stabilizer did not have a significant effect. MSs of the same size, but different morphologies, exhibited different protein release behavior, with porous structures being essential for the continuous and complete release of encapsulated protein. These findings suggest strategies to engineer the morphology of MSs produced from PLGA-based multi-block copolymers to achieve appropriate release rates for a protein delivery system.     

Characteristics of schools of nursing operating academic nurse-managed centers

Academic nurse-managed centers (ANMCs) can be important sites for addressing the tripartite mission of the academy. Yet, limited information about numbers of ANMCs and the schools sponsoring them is available. This paper presents an update on schools of nursing (SONs) operating ANMCs. A survey was sent to 683 deans and directors of baccalaureate and higher-degree SONs, with 565 responding (response rate: 83%). Ninety-two SONs indicated they had one or more ANMCs. The largest percentage of the SONs with ANMCs were classified as doctoral/research-intensive or extensive universities, a proportion much higher than the national percent of SONs in this category. Schools of Nursing were financially supporting centers at a lower percentage of actual costs than was reported in earlier studies, although grants continue to be a major source of funding. Academic nurse-managed centers are likely to be supported by SONs with substantial research, practice, faculty, and student resources. Overall, the national number of ANMCs seems stationary over the past two decades.     

An 8-year prospective follow-up study of physicians departing health care in Belgium (1994-2002)

Several OECD countries have capped the number of physicians to be licensed to practice. However, a relevant cap must take into account changes in physician activities. We set out to study the transitions leading physicians to leave health care or to stop any activity in health system. These transitions were assessed using a register of medical practice. We studied changes in activity between 1994 and 2002 for about 19,840 physicians who in 1994 were already working for 5 years and were in 2002 less than 65 years old. After 8 years of career, one physician out of 20 were inactive in health system. Some medical specialties such as surgery and radiotherapy had a greater risk of leaving health care while GP's had a lower risk. Gender differences in leaving health system were mostly non-existant in younger age groups but then increased with age. Among physicians aged 55 and over, women were more likely to leave health system. We conclude that the percentage of physicians leaving health care after 5 years of practice is significant and deserve being taken into account for manpower planning and that planning should be aware of that some groups of physicians are more at risk than others to leave health care. Qualitative studies would help understand better this drop out.     

Multipoint dilution hemofiltration: A new technology for maximum convective clearance

Convection-based renal replacement therapies (RRTs) have the potential to improve patient outcomes when compared to diffusion-based RRT such as hemodialysis (HD), but have limited clearance rates. We propose and characterize multipoint dilution hemofiltration (MPD-HF), a purely convective blood purification technology which removes the fundamental filtration limit associated with convective RRT resulting in clearance rates on par with HD. In MPD-HF, filtration of liquid and solutes occurs along the length of the hollow fibers that convey the blood, and substitution fluid is pushed into the fibers at multiple points along their length. Since multiple filtration and dilution steps are contained within one pass of the blood through the hollow fiber, the fraction of fluid that can be filtered may be increased to allow a high clearance rate that removes a wide range of toxins. In vitro tests yielded an average steady-state filtrate fraction of 68%, exceeding commercial HDF cartridge filtrate fractions by a factor of approximately 3. The molecular weights of molecules cleared spans up to the cutoff of 66 kDa for albumin.     

The Lifetime Effect of Residential School Attendance on Indigenous Health Status

Objectives. I examined the health impact of lifetime Indian Residential school (IRS) attendance and the mediating influences of socioeconomic status and community adversity on health outcomes in a national sample of Aboriginal peoples in Canada.Methods. In an analysis of data on 13 881 Inuit, Métis, and off-reserve First Nations or North American Indian adults responding to the postcensus 2006 Aboriginal Peoples Survey administered October 2006 to March 2007, I tested the direct effect of IRS attendance on health and indirect effects through socioeconomic and community factors using logistic regression procedures.Results. Negative health status was significantly more likely with IRS attendance than nonattendance. The direct effect of IRS attendance remained significant although it attenuated substantially when adjusting for demographic characteristics, socioeconomic status, and community-level adversities. Community adversity and socioeconomic factors, primarily income, employment status, and educational attainment mediated the effect of IRS on health.Conclusions. Residential school attendance is a significant health determinant in the Indigenous population and is adversely associated with subsequent health status both directly and through the effects of attendance on socioeconomic and community-level risks.The prevalence of poor general health in the Canadian population continues to be substantially higher among Aboriginal peoples than non-Aboriginal peoples.1–3 The disparity and greater burden of illness in the Indigenous population have been attributed in part to the enduring effects of colonization that destabilized Aboriginal cultural, economic, and community systems.3 Establishment of the Indian residential school (IRS) system and enforcement of compulsory enrollment for school-aged Aboriginal children constituted some of the most assertive means by which the Canadian government administered colonial policies. There are potential health risks associated with IRS attendance3–5; however, these effects, and factors explaining health outcomes were not assessed systematically in previous research. The etiology of negative health status among residential school attenders has been obscured partly because of the failure to expand the scope of Indigenous health determinants in empirical analysis to consider simultaneously the influences of early colonization-specific experiences and more proximal socioeconomic disadvantages and adverse psychosocial and community conditions.I examined the effect of lifetime residential school attendance on self-reported health status and the extent to which socioeconomic and community adversities were pathways linking IRS attendance histories to health outcomes in Inuit, Métis, and off-reserve First Nations or North American Indian adults surveyed across Canada for the 2006 Aboriginal Peoples Survey. Self-assessed general health is a strong predictor of morbidity independent of sociodemographic factors, is highly correlated with physician-assessed health status, predicts health care system spending,6,7 and is a culturally relevant, valid indicator of health in Indigenous populations.8 By using national data inclusive of multiple Indigenous groups, and comprehensive analytic procedures to test models incorporating an array of risk factors disproportionately affecting the Indigenous population, I was able to address some limitations of previous research on Indigenous health attributable to limited use of multivariate analysis for determining mechanisms mediating the impact of colonization-related experiences on health, lack of national data derived from culturally relevant indicators of health and measures in common across Aboriginal groups, and nonrepresentativeness owing to insufficient inclusion of urban and off-reserve populations and Indigenous peoples residing in isolated geographic areas.The results are relevant to locating critical points of intervention for reducing population health disparities and the greater burden of illness in vulnerable groups undergoing rapid population growth. As of the 2011 enumeration of the population, more than 1.4 million persons, or 4.3% of the population of Canada, were Aboriginal people reporting North American Indian (First Nations), Métis, Inuit, or other Aboriginal identities.9 Approximately three quarters, including status and nonstatus Indians and the Métis and Inuit, resided off reserve. By year 2031, the Aboriginal population is projected to increase to 1.7 to 2.2 million.10