Effect of diuretics on kidney stone-forming risk – an investigation using multiple timed urine collections

Introduction: Thiazide diuretics can lower urinary calcium excretion, helping to prevent recurrent calcium kidney stones. As dietary intake and urine chemistry varies throughout the day, a 24-h urine collection may not provide sufficient information to guide the optimal management in individual patients. Using multiple timed urine collections, we sought to identify times during the day when stone-forming risk is higher, allowing for therapy to be more accurately targeted. Methods: In a prospective study, healthy adult volunteers took a 4-week course of either hydrochlorothiazide (HCTZ) 25 mg/d or indapamide 2.5 mg/d. They were assessed at baseline, and at days 7, 14 and 28. At each time point, blood samples were taken for analysis and multiple timed urine samples were collected throughout the day, together with one overnight sample. Results: Diuretic treatment was well tolerated. Daily calcium and citrate excretion decreased, while ionized calcium and phosphate excretion were unchanged. Ionized calcium-divalent phosphate and ionized calcium-oxalate products were unchanged. In the timed urine samples, calcium excretion was decreased, particularly by indapamide, in the morning. Indapamide, but not HCTZ, decreased urinary citrate excretion, most obviously in overnight and early morning urines. No changes in ionized calcium were observed. Decreased divalent phosphate excretion was observed at several time points in the indapamide group. The ionized calcium-divalent phosphate product tended to decrease at most time points in both groups but no significant changes were observed in the ionized calcium-oxalate product. Conclusions: Indapamide 2.5 mg/d has a stronger protective effect against forming calcium kidney stones than HCTZ 25 mg/d. Most of the benefits appear to be achieved during the daytime and it may therefore be beneficial to prescribe medication twice daily or in the evening to maximize the protective effects of these agents. The benefits of indapamide treatment were attenuated by a reduction in urinary citrate excretion, an effect which has not been previously described

Clinical staff knowledge and awareness of point of care testing best practices at Tygerberg Hospital, South Africa

Background: Point-of-care testing (POCT) is defined as testing done near or at the site of patient care with the goal of providing rapid information and improving patient outcomes. Point-of-care testing has many advantages and some limitations which affect its use and implementation. Objective: The aim of the audit was to determine the current practices, staff attitudes and training provided to hospital clinical staff. Methods: The audit was conducted with the use of a questionnaire containing 30 questions. One hundred and sixty questionnaires were delivered to 55 sites at Tygerberg Academic Hospital in Cape Town, South Africa, from 21 June 2016 to 15 July 2016. A total of 68 questionnaires were completed and returned (42.5% response rate). Results: Most participants were nursing staff (62/68, 91%), and the rest were medical doctors (6/68, 9%). Most participants (66/68, 97%) performed glucose testing, 16/68 (24%) performed blood gas testing and 17/68 (25%) performed urine dipstick testing. Many participants (35/68, 51%) reported having had some formal training in one or more of the tests and 25/68 (37%) reported having never had any formal training in the respective tests. Many participants (46/68, 68%) reported that they never had formal assessment of competency in performing the respective tests. Conclusion: Participants indicated a lack of adequate training in POCT and, thus, limited knowledge of quality control measures. This audit gives an indication of the current state of the POCT programme at a tertiary hospital and highlights areas where intervention is needed to improve patient care and management

Illicit drug use and violence in acute psychosis among acute adult admissions at a South African psychiatric hospital

Background and objective: The prevalence of mental illness and illicit substance use has increased markedly in South Africa\u2019s Western Cape Province, over the last 2 decades; potentially increasing demand for psychiatric care. This paper describes the demographic and substance use profile of patients admitted to Lentegeur (LGH), the largest of the four psychiatric hospitals in the Province. Methods: Medical records, patient interviews and other clinical notes were used to collect data on demographics, illicit substance use, violent behaviour and utilization of rehabilitative services for patients (n=535) admitted to LGH between 1 August 2012 and 31 January 2013. Results: Majority of admissions were male (65.6%) and younger (69.8% < 35 years) compared to females (62.6% >35 years). Overall, 255 (49%) used an illicit substance, (24% females and 63% males). Majority of substance users were youth (18\u201335 years) in both males (83.1%) and females (73.8%). Cannabis and methamphetamine were the most popular drugs in males (56.3% and 34.9%) and females (17.9% and 16.2%) with the highest rates being among the youth. Violence was common among both men (60.7%) and women (40.8%); among the violent, 67% of males and 35.6% of female used substances. Only 5.5% of drug users utilized formal drug rehabilitation services. Conclusion: Substance use and violence were high, yet only a small proportion of the patients utilised available drug rehabilitation services. This may have implications on psychotic relapses, morbidity and subsequent pressure on financial resources within the health care system. Efforts are needed to maximise utilisation of existing rehabilitative resources for these patients

The NESHIE and CP Genetics Resource (NCGR): A database of genes and variants reported in neonatal encephalopathy with suspected hypoxic ischemic encephalopathy (NESHIE) and consequential cerebral palsy (CP)

DATA AVAILABILTY : All data generated or analysed during this study are included in this published article, supplementary information files, and the NCGR database repository. Access to the NCGR database is available at http://ncgr.bi.up.ac.za/. Additional data will be made available on request.SUPPLEMENTARY DATA : SUPPLEMENTARY FIG. 1. User input for a complex query generated using NCGR's filter functionality to prioritise genes likely to predispose individuals to NESHIE. Abbreviations: CP: cerebral palsy; NESHIE: neonatal encephalopathy with suspected hypoxic ischemic encephalopathy; HPO: human phenotype ontology; NCGR: NESHIE and CP genetics resource.SUPPLEMENTARY FIG. 2. Protein-protein interaction network constructed using genes that were prioritised based on evidence of potential involvement in a genetic predisposition to neonatal encephalopathy with suspected hypoxic ischaemic encephalopathy (NESHIE). Protein products of the input set of genes are represented by blue nodes. Additional direct and secondary interactors of the input set are represented in grey.SUPPLEMENTARY DATA A. Methods used to perform gene ontology enrichment and protein-protein interaction network analyses.SUPPLEMENTARY DATA B. Gene Ontology enrichment resultsSUPPLEMENTARY TABLE 1. Variant Details table data.SUPPLEMENTARY TABLE 2. Ensembl Variant Effect Prediction table data.SUPPLEMENTARY TABLE 3. Gene Details table data.SUPPLEMENTARY TABLE 4. Gene Human Phenotype Ontology table data.SUPPLEMENTARY TABLE 5. MutationTaster Variant Effect Prediction table data.SUPPLEMENTARY TABLE 6. Study Details table data.SUPPLEMENTARY TABLE 7. Study Findings table data.Neonatal encephalopathy (NE) with suspected hypoxic ischaemic encephalopathy (HIE) (NESHIE) is a complex syndrome occurring in newborns, characterised by altered neurological function. It has been suggested that genetic variants may influence NESHIE susceptibility and outcomes. Unlike NESHIE, for which a limited number of genetic studies have been performed, many studies have identified genetic variants associated with cerebral palsy (CP), which can develop from severe NESHIE. Identifying variants in patients with CP, as a consequence of NESHIE, may provide a starting point for the identification of genetic variants associated with NESHIE outcomes. We have constructed NCGR (NESHIE and CP Genetics Resource), a database of genes and variants reported in patients with NESHIE and CP (where relevant to NESHIE), for the purpose of collating and comparing genetic findings between the two conditions. In this paper we describe the construction and functionality of NCGR. Furthermore, we demonstrate how NCGR can be used to prioritise genes and variants of potential clinical relevance that may underlie a genetic predisposition to NESHIE and contribute to an understanding of its pathogenesis.The Bill & Melinda Gates Foundation, Seattle, USA; the South African Medical Research Council, Cape Town, South Africa; and the University of Pretoria through the Institute for Cellular and Molecular Medicine.https://www.elsevier.com/locate/ygenohj2023BiochemistryGeneticsImmunologyMicrobiology and Plant Patholog

Chronic kidney diseases in mixed ancestry South African populations : prevalence, determinants and concordance between kidney function estimators

Publication of this article was funded by the Stellenbosch University Open Access Fund.The original publication is available at http://www.biomedcentral.com/bmcnephrolBackground: Population-based data on the burden of chronic kidney disease (CKD) in sub-Saharan Africa is still very limited. We assessed the prevalence and determinants of CKD, and evaluated the concordance of commonly advocated estimators of glomerular filtration rate (eGFR) in a mixed ancestry population from South Africa. Methods: Participants were a population-based sample of adults selected from the Bellville-South community in the metropolitan city of Cape Town. eGFR was based on the Cockroft-Gault (CG), Modification of Diet in Kidney Disease (MDRD) and CKD Epidemiology Collaboration (CKD-EPI) equations (with and without adjustment for ethnicity). Kidney function staging used the Kidney Disease Outcome Quality Initiative (KDOQI) classification. Logistic regressions and kappa statistic were used to investigate determinants of CKD and assess the agreement between different estimators. Results: The crude prevalence of CKD stage 3–5 was 14.8% for Cockcroft-Gault, 7.6% and 23.9% respectively for the MDRD with and without ethnicity correction, and 7.4% and 17.3% for the CKD-EPI equations with and without ethnicity correction. The highest agreement between GFR estimators was between MDRD and CKD-EPI equations, both with ethnicity correction, Kappa 0.91 (95% CI: 0.86-0.95), correlation coefficient 0.95 (95% CI: 0.94-0.96). In multivariable logistic regression models, sex, age and known hypertension were consistently associated with CKD stage 3–5 across the 5 estimators Conclusions: The prevalence of CKD stages greater than 3 is the highest reported in Africa. This study provides evidence for support of the CKD-EPI equation for eGFR reporting and CKD classification.Stellenbosch University Open Access FundPublishers' versio

Oxidative and haemostatic effects of copper, manganese and mercury, alone and in combination at physiologically relevant levels: an ex vivo study

Water contamination with metals due to anthropogenic activity is increasing and subsequent exposure increases the risk of associated toxicity. Exposure is not limited to a single metal but usually involves mixtures of different metals at different concentrations. Little is known about the contribution of this type of exposure, in humans, to the development of non-communicable diseases such as cardiovascular disease, and an increased risk to thrombosis. The World Health Organization has established limits for metal levels in drinking water and this includes levels for copper (Cu), manganese (Mn) and mercury (Hg). In this study, at 100X these limits, the ability of the metals’ oxidative effects as catalysts of the Fenton reaction and/or ability to bind glutathione (GSH) were determined. The haemostatic effects of these metals, alone and in combination, at the World Health Organization limit were then evaluated. The ultrastructural and viscoelastic alterations of exposed ex vivo whole blood were also evaluated using scanning electron microscopy and thromboelastography® (TEG), respectively. Cu, alone and in combination with Mn and/or Hg, induced hydroxyl radical formation and reduced GSH levels. Ex vivo exposure caused deformation of erythrocytes and accelerated platelet activation especially for Cu, alone and in combination, with Mn. Reduction in the lysis potential of the clot was also observed for all combinations, especially Cu in combination with Hg as well as Mn alone. Although the TEG findings were not statistically significant, the trends indicate that the exposure to these metals, alone and in combination, adversely affects thrombus formation in ex vivo blood, thereby potentially increasing the risk in exposed individuals for thrombosis.The National Research Foundation under grant number 92768.https://journals.sagepub.com/home/hethj2019AnatomyPhysiolog

Evaluation of Typhoid Conjugate Vaccine Effectiveness in Ghana (TyVEGHA) Using a Cluster-Randomized Controlled Phase IV Trial: Trial Design and Population Baseline Characteristics.

Typhoid fever remains a significant health problem in sub-Saharan Africa, with incidence rates of >100 cases per 100,000 person-years of observation. Despite the prequalification of safe and effective typhoid conjugate vaccines (TCV), some uncertainties remain around future demand. Real-life effectiveness data, which inform public health programs on the impact of TCVs in reducing typhoid-related mortality and morbidity, from an African setting may help encourage the introduction of TCVs in high-burden settings. Here, we describe a cluster-randomized trial to investigate population-level protection of TYPBAR-TCV®, a Vi-polysaccharide conjugated to a tetanus-toxoid protein carrier (Vi-TT) against blood-culture-confirmed typhoid fever, and the synthesis of health economic evidence to inform policy decisions. A total of 80 geographically distinct clusters are delineated within the Agogo district of the Asante Akim region in Ghana. Clusters are randomized to the intervention arm receiving Vi-TT or a control arm receiving the meningococcal A conjugate vaccine. The primary study endpoint is the total protection of Vi-TT against blood-culture-confirmed typhoid fever. Total, direct, and indirect protection are measured as secondary outcomes. Blood-culture-based enhanced surveillance enables the estimation of incidence rates in the intervention and control clusters. Evaluation of the real-world impact of TCVs and evidence synthesis improve the uptake of prequalified/licensed safe and effective typhoid vaccines in public health programs of high burden settings. This trial is registered at the Pan African Clinical Trial Registry, accessible at Pan African Clinical Trials Registry (ID: PACTR202011804563392)

Evaluation of Typhoid Conjugate Vaccine Effectiveness in Ghana (TyVEGHA) Using a Cluster-Randomized Controlled Phase IV Trial: Trial Design and Population Baseline Characteristics.

Typhoid fever remains a significant health problem in sub-Saharan Africa, with incidence rates of >100 cases per 100,000 person-years of observation. Despite the prequalification of safe and effective typhoid conjugate vaccines (TCV), some uncertainties remain around future demand. Real-life effectiveness data, which inform public health programs on the impact of TCVs in reducing typhoid-related mortality and morbidity, from an African setting may help encourage the introduction of TCVs in high-burden settings. Here, we describe a cluster-randomized trial to investigate population-level protection of TYPBAR-TCV®, a Vi-polysaccharide conjugated to a tetanus-toxoid protein carrier (Vi-TT) against blood-culture-confirmed typhoid fever, and the synthesis of health economic evidence to inform policy decisions. A total of 80 geographically distinct clusters are delineated within the Agogo district of the Asante Akim region in Ghana. Clusters are randomized to the intervention arm receiving Vi-TT or a control arm receiving the meningococcal A conjugate vaccine. The primary study endpoint is the total protection of Vi-TT against blood-culture-confirmed typhoid fever. Total, direct, and indirect protection are measured as secondary outcomes. Blood-culture-based enhanced surveillance enables the estimation of incidence rates in the intervention and control clusters. Evaluation of the real-world impact of TCVs and evidence synthesis improve the uptake of prequalified/licensed safe and effective typhoid vaccines in public health programs of high burden settings. This trial is registered at the Pan African Clinical Trial Registry, accessible at Pan African Clinical Trials Registry (ID: PACTR202011804563392)

Copy number variants as modifiers of breast cancer risk for BRCA1/BRCA2 pathogenic variant carriers

The risk of germline copy number variants (CNVs) in BRCA1 and BRCA2 pathogenic variant carriers in breast cancer is assessed, with CNVs overlapping SULT1A1 decreasing breast cancer risk in BRCA1 carriers.The contribution of germline copy number variants (CNVs) to risk of developing cancer in individuals with pathogenic BRCA1 or BRCA2 variants remains relatively unknown. We conducted the largest genome-wide analysis of CNVs in 15,342 BRCA1 and 10,740 BRCA2 pathogenic variant carriers. We used these results to prioritise a candidate breast cancer risk-modifier gene for laboratory analysis and biological validation. Notably, the HR for deletions in BRCA1 suggested an elevated breast cancer risk estimate (hazard ratio (HR) = 1.21), 95% confidence interval (95% CI = 1.09-1.35) compared with non-CNV pathogenic variants. In contrast, deletions overlapping SULT1A1 suggested a decreased breast cancer risk (HR = 0.73, 95% CI 0.59-0.91) in BRCA1 pathogenic variant carriers. Functional analyses of SULT1A1 showed that reduced mRNA expression in pathogenic BRCA1 variant cells was associated with reduced cellular proliferation and reduced DNA damage after treatment with DNA damaging agents. These data provide evidence that deleterious variants in BRCA1 plus SULT1A1 deletions contribute to variable breast cancer risk in BRCA1 carriers.Peer reviewe