429 research outputs found

    Vitamin A status of HIV-infected adults in South Africa

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    Introduction: Several studies in developed countries such as the USA have reported low serum or plasma vitamin A levels in adults with HIV disease. Limited data suggests that HIV-infected adults from developing countries show even lower vitamin A levels. Factors that contribute to a low vitamin A status include a poor intake, malabsorption and repeated episodes of infections resulting in a decreased hepatic mobilisation of vitamin A during the acute phase response, an accelerated utilisation of vitamin A or increased urinary losses of vitamin A. Aim: To determine the vitamin A status of HIV-infected adults without major active opportunistic infections with WHO clinical stages 1 to 4 HIV-infection. Methods: One hundred and thirty-two HIV-positive patients were included in a cross-sectional study at the outpatient clinic at Groote Schuur Hospital. Exclusion criteria included current use of multivitamin or vitamin A supplements, pregnancy, pyrexia (> 38 °C) and patients who had received TB treatment for less than 12 weeks. We obtained data on demographic characteristics, weight and height, CD4 lymphocyte levels, CD4:CD8 ratio, full blood count and plasma levels of retinal, retinal-binding protein, zinc and CRP. Results: The sample consisted of 51, 48 and 33 patients with WHO Stage 1/2, 3 and 4 HIV-infection, respectively. The proportion of patients with borderline vitamin A levels ( 100 mg/l. Seventy seven percent (39/51) of patients with early disease had CRP levels 40 mg/l. The median retinal level of patients with CRP levels> 40 mg/l (n=7) was 16.8 μg/l versus 27.3 μg/l and 30.2 μg/l in the other two categories (p < 0.05). A similar relationship between CRP and plasma zinc levels was observed, although not significant (p < 0.1). Multivariate analysis revealed that a borderline retinal status was independently associated with a 3-fold increase (95%CI: 2-5.6) in the risk of having stage 4 disease or AIDS after adjusting for CD4 lymphocyte count or the CD4:CD8 ratio, haemoglobin, plasma zinc and body weight. Conclusions: Patients with advanced disease are more likely to have a borderline vitamin A status in the absence of opportunistic infections. The majority of patients with symptomatic disease had mildly raised CRP levels, possibly reflecting HIV-viral activity. CRP levels were associated with low retinal levels only in a small number of subjects, possibly indicating the presence of underlying infection, despite the clinical review of our data. Although our data indicates an independent relationship between retinal levels and advanced disease, the cross-sectional design precludes causal inferences about this association

    Numerical and asymptotic solutions of generalised Burgers’ equation

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    The generalised Burgers’ equation has been subject to a considerable amount of research on how the equation should behave according to asymptotic analysis, however there has been limited research verifying the asymptotic analysis. In order to verify the asymptotic analysis, this paper aims to run long time and detailed numerical simulations of Burgers’ equation by employing suitable rescalings of Burgers’ equation. It is hoped that this technique will make it possible to notice subtle changes in the shock structure which would otherwise be impossible to observe. The main aim of this paper is to validate the numerical methods used in order to allow further research into shock evolution where further relaxation effects will be included

    Micronutrient supplementation in adults with HIV infection.

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    Background Micronutrient deficiencies are common among adults living with HIV disease, particularly in low-income settings where the diet may be low in essential vitamins and minerals. Some micronutrients play critical roles in maintenance of the immune system, and routine supplementation could therefore be beneficial. This is an update of a Cochrane Review previously published in 2010. Objectives To assess whether micronutrient supplements are effective and safe in reducing mortality and HIV-related morbidity of HIV-positive adults (excluding pregnant women). Search methods We performed literature searches from January 2010 to 18 November 2016 for new randomized controlled trials (RCTs) of micronutrient supplements since the previous review included all trials identified from searches prior to 2010. We searched the CENTRAL (the Cochrane Library), Embase, and PubMed databases. Also we checked the World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP) and the ClinicalTrials.gov trials registers. We also checked the reference lists of all new included trials. Selection criteria We included RCTs that compared supplements that contained either single, dual, or multiple micronutrients with placebo, no treatment, or other supplements. We excluded studies that were primarily designed to investigate the role of micronutrients for the treatment of HIV-positive participants with metabolic morbidity related to highly active antiretroviral therapy (HAART). Primary outcomes included all-cause mortality, morbidity, and disease progression. Data collection and analysis Two review authors independently selected trials for inclusion, and appraised trial quality for risk of bias. Where possible, we presented results as risk ratios (RR) for dichotomous variables, as hazard ratios (HRs) for time-to-event data, and as mean differences (MD) for continuous variables, each with 95% confidence intervals (CIs). Since we were often unable to pool the outcome data, we tabulated it for each comparison. We assessed the certainty of the evidence using the GRADE approach. Main results We included 33 trials with 10,325 participants, of which 17 trials were new trials. Ten trials compared a daily multiple micronutrient supplement to placebo in doses up to 20 times the dietary reference intake, and one trial compared a daily standard dose with a high daily dose of multivitamins. Nineteen trials compared supplementation with single or dual micronutrients (such as vitamins A and D, zinc, and selenium) to placebo, and three trials compared different dosages or combinations of micronutrients. Multiple micronutrients We conducted analyses across antiretroviral therapy (ART)-naive adults (3 trials, 1448 participants), adults on antiretroviral therapy (ART) (1 trial, 400 participants), and ART-naive adults with concurrent active tuberculosis (3 trials, 1429 participants). Routine multiple micronutrient supplementation may have little or no effect on mortality in adults living with HIV (RR 0.91, 95% CI 0.72 to 1.15; 7 trials, 2897 participants, low certainty evidence). Routine supplementation for up to two years may have little or no effect on the average of mean CD4+ cell count (MD 26.40 cells/mm³, 95% CI −22.91 to 75.70; 6 trials, 1581 participants, low certainty evidence), or the average of mean viral load (MD −0.1 log10viral copies, 95% CI −0.26 to 0.06; 4 trials, 840 participants, moderate certainty evidence). One additional trial in ART-naïve adults did report an increase in the time to reach a CD4+ cell count < 250 cells/mm³ after two years of high dose supplementation in Botswana (HR 0.48, 95% CI 0.26 to 0.88; 1 trial, 439 participants). However, the trial authors reported this effect only in the trial arm that received multiple micronutrients plus selenium (not either supplementation alone), which is inconsistent with the findings of other trials that used similar combinations of micronutrients and selenium. In one additional trial that compared high-dose multiple micronutrient supplementation with standard doses in people on ART, peripheral neuropathy was lower with high dose supplements compared to standard dose (incidence rate ratio (IRR) 0.81, 95% CI 0.7 to 0.94; 1 trial, 3418 participants), but the trial was stopped early due to increased adverse events (elevated alanine transaminase (ALT) levels) in the high dose group. Single or dual micronutrients None of the trials of single or dual micronutrient supplements were adequately powered to assess for effects on mortality or morbidity outcomes. No clinically significant changes in CD4 cell count (data not pooled, 14 trials, 2370 participants, very low or low certainty evidence) or viral load (data not pooled, seven studies, 1334 participants, very low or low certainty evidence), were reported. Supplementation probably does increase blood concentrations of vitamin D and zinc (data not pooled, vitamin D: 4 trials, 299 participants, zinc: 4 trials, 484 participants, moderate certainty evidence) and may also increase blood concentrations of vitamin A (data not pooled, 3 trials, 495 participants, low certainty evidence), especially in those who are deficient. Authors' conclusions The analyses of the available trials have not revealed consistent clinically important benefits with routine multiple micronutrient supplementation in people living with HIV. Larger trials might reveal small but important effects. These findings should not be interpreted as a reason to deny micronutrient supplements for people living with HIV where specific deficiencies are found or where the person's diet is insufficient to meet the recommended daily allowance of vitamins and minerals

    Cervical collar or physiotherapy versus wait and see policy for recent onset cervical radiculopathy: randomised trial

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    Objective To evaluate the effectiveness of treatment with collar or physiotherapy compared with a wait and see policy in recent onset cervical radiculopathy

    Waist circumference predicts clustering of cardiovascular risk factors in older South Africans

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    Objecti~'eand design. A cross-sectional analytical study to determine the cardiovascular risk factor profile of older residents of fishing villages on the West Coast of South Africa, and to det.ermine which anthropometric measures are associated with risk factors. Subjects. A convenient community-based sample of 152 subjects of mixed ancestry aged 55 years and over was recruited door-to-door using an address list of ageeligible subjects provided by the local public health care clinics. Methods. Cardiovascular relationships were im'estigated between: (i) number of risk factors (hypertension, hypercholesterolaemia, diabetes) and body mass index (8MI), waist-to-hip ratio (WHR), and waist circumference; and (ii) continuous cardiovascular risk factor variables and physical activity, smoking, dietary intake, and 24-hour urinary sodium and potassium concentrationS. Results. The prevalence of hypertension (~ 160/95 mmHg) was 74.3% (95% CI: 67.2 - 81.4%). Neither 24- hour urinary sodium nor potassium concentrations was associated with blood pressure (BP). Past, but not present, moderate-intensity physical activity, particularly that associated with occupation, was negatively associated with systolic BP (r = -0.24, P < 0.05). The prevalence of diabetes and hypercholesterolaemia (serum cholesterol ~ 6.5 mmolll) was 24.6% (95% CI: 17.2 - 32%) and 40% (95% CI: 31.8 - 48.2%),respectively. The percentage of subjects with 0, 1, or 2 or more cardiovascular risk factors was 13.4%,44.1% and 42.5%, respectively. Subjects with a waist circumference ~ 92 em had a significantly higher number of cardiovascular risk factors than those with a waist circumference < 92 cm (Xl =9.29, P < 0.01), and this association remained significant even after controlling for age, sex and smoking (P < 0.05). Neither 8MI tertiles according to sex, nor a 8MI cut-point ~ 30, was significantly associated with a clustering of risk factors. COllclusioll. In a sample of older South Africans of ntlxed ancestry at high risk of cardiovascular disease, waist circumference ~ 92 em predicts clustering of risk factors, Independentl)' of BMI. This simple, populationspecific reference value may provide a useful screening tool to identify at-risk Individuals for targeted prevention for coronary heart disease and associated metabolic disorders

    PMP22 related neuropathies: Charcot-Marie-Tooth disease type 1A and Hereditary Neuropathy with liability to Pressure Palsies

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    PMP22 related neuropathies comprise (1) PMP22 duplications leading to Charcot-Marie-Tooth disease type 1A (CMT1A), (2) PMP22 deletions, leading to Hereditary Neuropathy with liability to Pressure Palsies (HNPP), and (3) PMP22 point mutations, causing both phenotypes. Overall prevalence of CMT is usually reported as 1:2,500, epidemiological studies show that 20-64% of CMT patients carry the PMP22 duplication. The prevalence of HNPP is not well known. CMT1A usually presents in the first two decades with difficulty walking or running. Distal symmetrical muscle weakness and wasting and sensory loss is present, legs more frequently and more severely affected than arms. HNPP typically leads to episodic, painless, recurrent, focal motor and sensory peripheral neuropathy, preceded by minor compression on the affected nerve. Electrophysiological evaluation is needed to determine whether the polyneuropathy is demyelinating. Sonography of the nerves can be useful. Diagnosis is confirmed by finding respectively a PMP22 duplication, deletion or point mutation. Differential diagnosis includes other inherited neuropathies, and acquired polyneuropathies. The mode of inheritance is autosomal dominant and de novo mutations occur. Offspring of patients have a chance of 50% to inherit the mutation from their affected parent. Prenatal testing is possible; requests for prenatal testing are not common. Treatment is currently symptomatic and may include management by a rehabilitation physician, physiotherapist, occupational therapist and orthopaedic surgeon. Adult CMT1A patients show slow clinical progression of disease, which seems to reflect a process of normal ageing. Life expectancy is norma

    NET-RMDs study: networks of fatigue and pain in rheumatic and musculoskeletal diseases - protocol for an international cross-sectional study

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    Introduction Fatigue and pain are the main symptoms of rheumatic and musculoskeletal diseases (RMDs). Healthcare professionals have a primary role in helping patients to manage both these symptoms, which are part of a complex network of co-occurring factors including sleep problems, psychological distress, social support, body weight, diet, inactive lifestyle and disease activity. The patterns of relationships (networks) between these factors and these symptoms, fatigue and pain, are largely unknown. The current proposal aims to reveal them using network estimation techniques. We will also consider differences in networks for subgroups of people with (1) different RMDs and (2) different clusters (profiles) of biopsychosocial factors. Methods and analysis Adults with at least one RMD will be recruited to this online cross-sectional observational project. To provide a complete overview, a large sample size from different countries will be included. A brief online survey, using 0–10 numeric rating scales will measure, for the past month, levels of fatigue and pain as well as scores on seven biopsychosocial factors. These factors were derived from literature and identified by interviews with patients, health professionals and rheumatologists. Using this input, the steering committee of the project decided the factors to be measured giving priority to those that can be modified in self-management support in community health centres worldwide. Network estimation techniques are used to detect the complex patterns of relationships between these biopsychosocial factors, fatigue and pain; and how these differ for subgroups of people with different RMDs and profiles. Ethics and dissemination Ethical approval of national Institutional Review Boards was obtained. The online survey includes an information letter and informed consent form. The findings will be disseminated via conferences and publications in peer-reviewed scientific journals, while public media channels will be used to inform people with RMDs and other interested parties

    Automatic detection of actionable findings and communication mentions in radiology reports using natural language processing

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    __Objectives:__ To develop and validate classifiers for automatic detection of actionable findings and documentation of nonroutine communication in routinely delivered radiology reports. __Me
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