418 research outputs found
Evidence of oxidative stress and mitochondrial dysfunction in spinocerebellar ataxia type 2 (SCA2) patient fibroblasts: Effect of coenzyme Q10 supplementation on these parameters
Spinocerebellar ataxia type 2 (SCA2) is a rare neurodegenerative disorder caused by a CAG repeat expansion in the ataxin-2 gene. We show increased oxidative stress, abnormalities in the antioxidant system, changes in complexes involved in oxidative phosphorylation and changes in mitochondrial morphology in SCA2 patient fibroblasts compared to controls, and we show that treatment with CoQ10 can partially reverse these changes. Together, our results suggest that oxidative stress and mitochondrial dysfunction may be contributory factors to the pathophysiology of SCA2 and that therapeutic strategies involving manipulation of the antioxidant system could prove to be of clinical benefit
CoQ10 Deficient Endothelial Cell Culture Model for the Investigation of CoQ10 Blood–Brain Barrier Transport
Primary coenzyme Q10 (CoQ10) deficiency is unique among mitochondrial respiratory chain disorders in that it is potentially treatable if high-dose CoQ10 supplements are given in the early stages of the disease.While supplements improve peripheral abnormalities, neurological symptoms are only partially or temporarily ameliorated. The reasons for this refractory response to CoQ10 supplementation are unclear, however, a contributory factor may be the poor transfer of CoQ10 across the blood–brain barrier (BBB). The aim of this study was to investigate mechanisms of CoQ10 transport across the BBB, using normal and pathophysiological (CoQ10 deficient) cell culture models. The study identifies lipoprotein-associated CoQ10 transcytosis in both directions across the in vitro BBB. Uptake via SR-B1 (Scavenger Receptor) and RAGE (Receptor for Advanced Glycation Endproducts), is matched by efflux via LDLR (Low Density Lipoprotein Receptor) transporters, resulting in no “net” transport across the BBB. In the CoQ10 deficient model, BBB tight junctions were disrupted and CoQ10 “net” transport to the brain side increased. The addition of anti-oxidants did not improve CoQ10 uptake to the brain side. This study is the first to generate in vitro BBB endothelial cell models of CoQ10 deficiency, and the first to identify lipoprotein-associated uptake and efflux mechanisms regulating CoQ10 distribution across the BBB. The results imply that the uptake of exogenous CoQ10 into the brain might be improved by the administration of LDLR inhibitors, or by interventions to stimulate luminal activity of SR-B1 transporters
Do Quality Improvement Initiatives Improve Outcomes for Patients in Antiretroviral Programs in Low- and Middle-Income Countries? A Systematic Review.
BACKGROUND: There have been a range of quality improvement (QI) and quality assurance initiatives in low- and middle-income countries to improve antiretroviral therapy (ART) treatment outcomes for people living with HIV. To date, these initiatives have not been systematically assessed and little is known about how effective, cost-effective, or sustainable these strategies are in improving clinical outcomes. METHODS: We conducted a systematic review adhering to PRISMA guidelines (PROSPERO ID: CRD42017071848), searching PubMed, MEDLINE, Embase, Web of Science, and the Cochrane database of controlled trials for articles reporting on the effectiveness of QI and quality assurance initiatives in HIV programs in low- and middle-income countries in relation to ART uptake, retention in care, adherence, viral load suppression, mortality, and other outcomes including cost-effectiveness and long-term sustainability. RESULTS: One thousand eight hundred sixty articles were found, of which 29 were included. QI approaches were categorized as follows: (1) health system approaches using QI methods; (2) QI learning networks including collaboratives; (3) standard-based methods that use QI tools to improve performance gaps; and (4) campaigns using QI methods. The greatest improvements were seen in ART uptake [median increase of 14.0%; interquartile range (IQR) -9.0 to 29.3], adherence [median increase of 22.0% (IQR -7.0 to 25.0)], and viral load suppression [median increase 26.0% (IQR -8.0 to 26.0)]. CONCLUSIONS: QI interventions can be effective in improving clinical outcomes; however, there was significant variability, making it challenging to identify which aspects of interventions lead to clinical improvements. Standardizing reporting and assessment of QI initiatives is needed, supported by national quality policies and directorates, and robust research
A temporal dimension to the influence of pollen rewards on bee behaviour and fecundity in Aloe tenuior
The net effect of pollen production on fecundity in plants can range from negative – when self-pollen interferes with fecundity due to incompatibility mechanisms, to positive – when pollen availability is associated with increased pollinator visitation and fecundity due to its utilization as a reward. We investigated the responses of bees to pollen and nectar rewards, and the effects of these rewards on pollen deposition and fecundity in the hermaphroditic succulent shrub Aloe tenuior. Self-pollinated plants failed to set fruit, but their ovules were regularly penetrated by self-pollen tubes, which uniformly failed to develop into seeds as expected from ovarian self-incompatibility (or strong early inbreeding depression). Bees consistently foraged for pollen during the morning and early afternoon, but switched to nectar in the late afternoon. As a consequence of this differential foraging, we were able to test the relative contribution to fecundity of pollen- versus nectar-collecting flower visitors. We exposed emasculated and intact flowers in either the morning or late afternoon to foraging bees and showed that emasculation reduced pollen deposition by insects in the morning, but had little effect in the afternoon. Despite the potential for self-pollination to result in ovule discounting due to late-acting self-sterility, fecundity was severely reduced in artificially emasculated plants. Although there were temporal fluctuations in reward preference, most bee visits were for pollen rewards. Therefore the benefit of providing pollen that is accessible to bee foragers outweighs any potential costs to fitness in terms of gender interference in this species
A survey of factors that influence diabetes self-management in people with severe mental illness
Aims/Objectives: The purpose of the study was (1) to understand patients and family caregivers’ experiences in managing severe hypoglycaemic events (SHE) and (2) to determine factors influencing their management.
Methods: A constructivist informed grounded theory design was used, with data derived from interviews with patients and their family members after experiencing a SHE and treated by Swiss emergency medical services or the emergency department.
Results: Patients identified different phases that they transitioned through while acquiring and developing skills in the prevention and management of SHE. These transitional phases were influenced by significant factors that affected their daily decision making. Some of the factors identified included family members’ involvement, different forms of knowledge as well as perception, interpretation and reflection. These factors were the main variables identified by patients and their family members to come to terms with the challenging life events associated with diabetes.
Conclusions: This study highlights the importance of a family-centred approach to better support patients and their family members in managing and potentially preventing SHE. The findings will enable the identification of opportunities to intervene during emergency care provision as well as the development of brief interventions and resources for use by healthcare professionals
HIV Prevention in High-Risk Women in South Africa: Condom Use and the Need for Change
INTRODUCTION: Young women are at disproportionate risk of HIV infection in South Africa. Understanding risk behaviors and factors associated with ability to negotiate safe sex and condom use is likely to be key in curbing the spread of HIV. Traditionally prevention efforts have focused on creating behavioral changes by increasing knowledge about HIV/AIDS. METHODS: This was a cross-sectional analysis from a prospective observational cohort study of 245 women at a high-risk of HIV infection in KwaZulu-Natal, South Africa. RESULTS: Participants demonstrated a high level of HIV/AIDS knowledge. Overall, 60.3% of participants reported condom use. Reported condom use at last sexual encounter varied slightly by partner type (57.0% with steady versus 64.4% with casual partners), and self-perceived ability to choose to use a condom was significantly lower with steady partners compared to casual partners (p<0.01). In multivariate analysis, women who had high school education were more likely to use condoms at their last sex encounter compared to those with only primary school education (RR of 1.36 (95% Confidence Interval (CI) 1.06-1.75) and 1.46 (95% CI 1.13-1.88) for grades 8-10 and 11-12, respectively). Those who used condoms as a contraceptive method were twice as likely to use condoms compared to women who did not report using them as a contraceptive method. Greater perceived ability to choose to use condoms was associated with higher self-reported condom use at last encounter, irrespective of partner type (RR = 2.65 (95% CI 2.15-32.5). DISCUSSION: Self-perceived ability to use condoms, level of formal education and condom use as a contraceptive were all significantly associated with self-reported condom use at last sexual encounter. These findings suggest that that gender inequality and access to formal education, as opposed to lack of HIV/AIDS knowledge, prevent safer sexual practices in South Africa
inVestIgating the pSychologIcal and ecONomic impAct of cataRact surgerY in Vietnam: The VISIONARY observational study protocol
<p>Abstract</p> <p>Background</p> <p>Visual impairment caused by cataracts not only affects an individual's quality of life but can also have a profound impact on other important psychological factors and on the economic circumstances of individuals and their households. Cataract surgery is an effective intervention to restore vision and is also associated with other positive consequences including improvements in quality of life, economic and psychological outcomes. While there has been an increase in the number and quality of cataract surgeries performed in Vietnam, the programs currently in place are still unable to meet the existing demand and need for surgery. Data on both the cost-effectiveness of cataract surgery and the economic and psychological impact of untreated cataract in this setting is lacking.</p> <p>Methods/Design</p> <p>This study, investigating the psychological and economic impact of cataract surgery in Vietnam (VISIONARY), will recruit and interview a sample of adults (18 years or over) who are referred for cataract surgery by one of the following sites and their outreach programs: Hue Eye Hospital; Thai Binh Eye Hospital; Binh Dinh Department of Health Eye Hospital and the Vinh Long Department of Health Social Disease Centre. All participants (those who have cataract surgery and those who do not have surgery) will be followed up at six and 12 months.</p> <p>Discussion</p> <p>This study is designed to examine the impact of low vision on household economic circumstances and psychological outcomes as well as to investigate the effectiveness and cost-effectiveness of cataract surgery in Vietnam. It will help to inform international and national non-government organisations working in the country and local policy-makers on priorities for further investment in eye-health services in this setting and their relevance to broader economic development goals.</p
Entomological Surveillance of Behavioural Resilience and Resistance in Residual Malaria Vector Populations.
The most potent malaria vectors rely heavily upon human blood so they are vulnerable to attack with insecticide-treated nets (ITNs) and indoor residual spraying (IRS) within houses. Mosquito taxa that can avoid feeding or resting indoors, or by obtaining blood from animals, mediate a growing proportion of the dwindling transmission that persists as ITNs and IRS are scaled up. Increasing frequency of behavioural evasion traits within persisting residual vector systems usually reflect the successful suppression of the most potent and vulnerable vector taxa by IRS or ITNs, rather than their failure. Many of the commonly observed changes in mosquito behavioural patterns following intervention scale-up may well be explained by modified taxonomic composition and expression of phenotypically plastic behavioural preferences, rather than altered innate preferences of individuals or populations. Detailed review of the contemporary evidence base does not yet provide any clear-cut example of true behavioural resistance and is, therefore, consistent with the hypothesis presented. Caution should be exercised before over-interpreting most existing reports of increased frequency of behavioural traits which enable mosquitoes to evade fatal contact with insecticides: this may simply be the result of suppressing the most behaviourally vulnerable of the vector taxa that constituted the original transmission system. Mosquito taxa which have always exhibited such evasive traits may be more accurately described as behaviourally resilient, rather than resistant. Ongoing national or regional entomological monitoring surveys of physiological susceptibility to insecticides should be supplemented with biologically and epidemiologically meaningfully estimates of malaria vector population dynamics and the behavioural phenotypes that determine intervention impact, in order to design, select, evaluate and optimize the implementation of vector control measures
Status of insecticide susceptibility in Anopheles arabiensis from Mwea rice irrigation scheme, Central Kenya
BACKGROUND: Control of the Anopheline mosquito vectors of malaria by use of insecticides has been shown to impact on both morbidity and mortality due to this disease. Evidence of insecticide resistance in different settings necessitates surveillance studies to allow prompt detection of resistance should it arise and thus enable its management. Possible resistance by Anopheles arabiensis mosquitoes from Mwea rice irrigation scheme in Central Kenya to insecticides in the four classes of insecticides approved by WHO for indoor residual spraying was investigated. METHODS: Susceptibility to DDT (an organochlorine), fenitrothion (an organophosphate), bendiocarb (a carbamate), lambdacyhalothrin and permethrin (both pyrethroids) was tested using standard WHO diagnostic bioassay kits. Bioassays were performed on non-blood fed mosquitoes one- to three-day old. Knockdown was recorded every 10 min and mortality 24 h post-exposure was noted. RESULTS: Mortality 24 h post-exposure was 100% for all insecticides except for lambdacyhalothrin, which averaged 99.46%. Knockdown rates at 10 min intervals were not significantly different between the Mwea population and the susceptible KISUMU strain of Anopheles gambiae sensu stricto control. The KDT(50 )and KDT(95 )values for the Mwea population were either lower than those for the control or higher by factors of no more than 2 for most comparisons and compared well with those of An. gambiae sensu lato categorized as susceptible in other studies. CONCLUSION: These results suggest that the Mwea population of An. arabiensis is susceptible to all the insecticides tested. This implies that vector control measures employing any of these insecticides would not be hampered by resistance
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