Intramural: Journal Articles

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All papers that are published (or in the process of being published) in a scientific journal by SAMRC staff.

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Now showing 1 - 5 of 118
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    Medical Encounters in a 90-km Ultramarathon Running Event: A 6-year Study in 103 131 Race Starters—SAFER XVII
    (Wolters Kluwer, 2022-01-01) Sewry, N.; Schwellnus, M.; Boulter, J.; Seocharan, I.; Jordaan, E.; Biostatistics Unit, South African Medical Research Council, South Africa.
    Objective: To determine the incidence and nature of illness-related medical encounters (MEs) at a 90-km, ultramarathon, mass, community-based, endurance running event. Design: Retrospective, descriptive epidemiological study. Setting: Comrades Marathon (90 km), South Africa. Participants: One lakh three thousand one hundred thirty-one race starters over 6 years (2014-2019). Independent variables: Incidence of moderate and serious/life-threatening MEs. Main outcome measures: All MEs were recorded by race medical doctors on race day each year. Medical encounters were recorded by severity, organ system, and final specific diagnosis (2019 consensus statement definition on mass community-based events). Incidences (I: per 1000 starters; 95% confidence intervals) were calculated for MEs. Results: There were 1971 illness-related MEs, with an overall incidence of 19.1 (range, 18.3-20.0). The incidence for serious/life-threatening MEs was 1.8 (range, 1.6-2.1). Incidences of MEs by organ systems affected were as follows: fluid/electrolyte (8.8; 8.3-9.4), central nervous system (4.0; 3.7-4.5), and gastrointestinal system (2.9; 2.6-3.2). Dehydration (I = 7.5: 7.0-8.1) and exercise-associated muscle cramping (I = 3.2: 2.9-3.6) were the 2 most common specific diagnoses. Conclusion: The incidence of MEs in the 90-km Comrades Marathon was one of the highest incidences of MEs reported in an endurance running event (1 in 52 starters and 1 in 556 starters for serious/life-threatening MEs). Preventative measures to reduce MEs are needed, and further investigations into the risk factors associated with MEs could assist in managing the risk and better prepare athletes, race organizers, and medical directors.
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    Identification of potential biomarkers for predicting the early onset of diabetic cardiomyopathy in a mouse model
    (Nature Publishing Group, 2020-07-23) Johnson, R.; Nxele, X.; Cour, M.; Sangweni, N.; Jooste, T.; Hadebe, N.; Samodien, E.; Benjeddou, M.; Mazino, M.; Louw, J.; Lecour, S.; Rabia Johnson: Biomedical Research and Innovation Platform (BRIP), South African Medical Research Council
    Type 2 diabetes (T2D) is characterized by metabolic derangements that cause a shift in substrate preference, inducing cardiac interstitial fibrosis. Interstitial fibrosis plays a key role in aggravating left ventricular diastolic dysfunction (LVDD), which has previously been associated with the asymptomatic onset of heart failure. The latter is responsible for 80% of deaths among diabetic patients and has been termed diabetic cardiomyopathy (DCM). Through in silico prediction and subsequent detection in a leptin receptor-deficient db/db mice model (db/db), we confirmed the presence of previously identified potential biomarkers to detect the early onset of DCM. Differential expression of Lysyl Oxidase Like 2 (LOXL2) and Electron Transfer Flavoprotein Beta Subunit (ETFβ), in both serum and heart tissue of 6-16-week-old db/db mice, correlated with a reduced left-ventricular diastolic dysfunction as assessed by high-resolution Doppler echocardiography. Principal component analysis of the combined biomarkers, LOXL2 and ETFβ, further displayed a significant difference between wild type and db/db mice from as early as 9 weeks of age. Knockdown in H9c2 cells, utilising siRNA of either LOXL2 or ETFβ, revealed a decrease in the expression of Collagen Type I Alpha1 (COL1A1), a marker known to contribute to enhanced myocardial fibrosis. Additionally, receiver-operating curve (ROC) analysis of the proposed diagnostic profile showed that the combination of LOXL2 and ETFβ resulted in an area under the curve (AUC) of 0.813, with a cut-off point of 0.824, thus suggesting the favorable positive predictive power of the model and further supporting the use of LOXL2 and ETFβ as possible early predictive DCM biomarkers.
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    Health worker experiences of and perspectives on engaging men in HIV care: A qualitative study in Cape Town, South Africa
    (SAGE, 2020-05-29) Mbokazi, N.; Madzima, R.; Leon, N.; Lurie, M.N.; Cornell, M.; Schmidt, B.M.; Colvin, C.J.; Health Systems Research Unit & Cocrane South Africa, South African Medical Research Council
    Men generally fare worse than women across the HIV cascade. While we know much about how men perceive the health services, we know little about how health workers (HWs) themselves have experienced engaging with men and what strategies they have used to improve this engagement. We interviewed 12 HWs in public health care services in Cape Town to better understand their experiences and perspectives. Health workers felt there were significant gaps in men's engagement with HIV care and identified masculine gender norms, the persistent impact of HIV stigma, and the competing priorities of employment as key barriers. They also highlighted a number of health service-related challenges, including a poor perception of the patient-provider relationship, frustration at low service quality, and unrealistic expectations of the health services. Health workers also described several strategies for more effectively engaging men and for making the health services both more male friendly and more people friendly.
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    The effectiveness of peer and community health worker-led self-management support programs for improving diabetes health-related outcomes in adults in low-and-middle-income countries: A systematic review
    (BMC, 2020-06-06) Werfalli, M.; Raubenheimer, P.J.; Engel, M.; Musekiwa, A.; Bobrow, K.; Peer, N.; Hoegfeldt, C.; Kalula, S.; Kengne, A.P.; Levitt, N.S.; South African Medical Research Council
    Objective: Community-based peer and community health worker-led diabetes self-management programs (COMP-DSMP) can benefit diabetes care, but the supporting evidence has been inadequately assessed. This systematic review explores the nature of COMP-DSMP in low- and middle-income countries' (LMIC) primary care settings and evaluates implementation strategies and diabetes-related health outcomes. Methods: We searched the Cochrane Library, PubMed-MEDLINE, SCOPUS, CINAHL PsycINFO Database, International Clinical Trials Registry Platform,, Pan African Clinical Trials Registry (PACTR), and HINARI (Health InterNetwork Access to Research Initiative) for studies that evaluated a COMP-DSMP in adults with either type 1 or type 2 diabetes in World Bank-defined LMIC from January 2000 to December 2019. Randomised and non-randomised controlled trials with at least 3 months follow-up and reporting on a behavioural, a primary psychological, and/or a clinical outcome were included. Implementation strategies were analysed using the standardised implementation framework by Proctor et al. Heterogeneity in study designs, outcomes, the scale of measurements, and measurement times precluded meta-analysis; thus, a narrative description of studies is provided. Results: Of the 702 records identified, eleven studies with 6090 participants were included. COMP-DSMPs were inconsistently associated with improvements in clinical, behavioural, and psychological outcomes. Many of the included studies were evaluated as being of low quality, most had a substantial risk of bias, and there was a significant heterogeneity of the intervention characteristics (for example, peer definition, selection, recruitment, training and type, dose, and duration of delivered intervention), such that generalisation was not possible. Conclusions: The level of evidence of this systematic review was considered low according to the GRADE criteria. The existing evidence however does show some improvements in outcomes. We recommend ongoing, but well-designed studies using a framework such as the MRC framework for the development and evaluation of complex interventions to inform the evidence base on the contribution of COMP-DSMP in LMIC.
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    Unspoken inequality: How COVID-19 has exacerbated existing vulnerabilities of asylum-seekers, refugees, and undocumented migrants in South Africa
    (BMC, 2020-08-20) Mukumbang, F.C.; Ambe, A.N.; Adebiyi, B.O.; Burden of Disease Research Unit, South African Medical Research Council
    An estimated 2 million foreign-born migrants of working age (15-64) were living in South Africa (SA) in 2017. Structural and practical xenophobia has driven asylum-seekers, refugees, and undocumented migrants in SA to abject poverty and misery. The Coronavirus Disease 2019 (COVID-19) containment measures adopted by the SA government through the lockdown of the nation have tremendously deepened the unequal treatment of asylum-seekers and refugees in SA. This can be seen through the South African government's lack of consideration of this marginalized population in economic, poverty, and hunger alleviation schemes. Leaving this category of our society out of the national response safety nets may lead to negative coping strategies causing mental health issues and secondary health concerns. An effective response to the socioeconomic challenges imposed by the COVID-19 pandemic should consider the economic and health impact of the pandemic on asylum-seekers, refugees, and undocumented migrants.