Cholecalciferol induces apoptosis via autocrine metabolism in epidermoid cervical cancer cells.

The anti-cancer effects of vitamin D are of fundamental interest. Cholecalciferol is sequentially hydroxylated endogenously to calcidiol and calcitriol. Here, SiHa epidermoid cervical cancer cells were treated with cholecalciferol (10-2600 nmol/L). Cell count and viability were assayed using Crystal Violet and Trypan Blue, respectively. Apoptosis was assessed using flow cytometry for early and late biomarkers along with brightfield microscopy and transmission electron microscopy. Autocrine vitamin D metabolism was analysed by reverse transcription-quantitative PCR and immunoblotting for activating enzymes: 25-hydroxylases (CYP2R1 and CYP27A1) and 1α-hydroxylase (CYP27B1), the catabolic 24-hydroxylase (CYP24A1), and the vitamin D receptor (VDR). Data were analysed using one-way ANOVA and Bonferroni post-hoc test, and p < 0.05 was considered significant. After cholecalciferol, cell count (p = 0.011) and viability (p < 0.0001) decreased, apoptotic biomarkers were positive, mitochondrial membrane potential decreased (p = 0.0145), and phosphatidylserine externalisation (p = 0.0439), terminal caspase activity (p = 0.0025), and nuclear damage (p = 0.004) increased. Microscopy showed classical features of apoptosis. Gene and protein expression were concordant. Immunoblots revealed increased CYP2R1 (p = 0.021), VDR (p = 0.04), and CYP24A1 (p = 0.0274) and decreased CYP27B1 (p = 0.031). The authors conclude that autocrine activation of cholecalciferol to calcidiol may mediate VDR signalling of growth inhibition and apoptosis in SiHa cells.

Sentinel seroprevalence of SARS-CoV-2 in Gauteng Province, South Africa, August - October 2020.

BACKGROUND: Estimates of prevalence of anti-SARS-CoV-2 antibody positivity (seroprevalence) for tracking the COVID-19 epidemic are lacking for most African countries. OBJECTIVES: To determine the prevalence of antibodies against SARS-CoV-2 in a sentinel cohort of patient samples received for routine testing at tertiary laboratories in Johannesburg, South Africa. METHODS: This sentinel study was conducted using remnant serum samples received at three National Health Laboratory Service laboratories in the City of Johannesburg (CoJ) district. Collection was from 1 August to 31 October 2020. We extracted accompanying laboratory results for glycated haemoglobin (HbA1c), creatinine, HIV, viral load and CD4 T-cell count. An anti-SARS-CoV-2 targeting the nucleocapsid (N) protein of the coronavirus with higher affinity for IgM and IgG antibodies was used. We reported crude as well as population-weighted and test-adjusted seroprevalence. Multivariate logistic regression analysis was used to determine whether age, sex, HIV and diabetic status were associated with increased risk for seropositivity. RESULTS: A total of 6 477 samples were analysed, the majority (n=5 290) from the CoJ region. After excluding samples with no age or sex stated, the model population-weighted and test-adjusted seroprevalence for the CoJ (n=4 393) was 27.0% (95% confidence interval (CI) 25.4 - 28.6). Seroprevalence was highest in those aged 45 - 49 years (29.8%; 95% CI 25.5 - 35.0) and in those from the most densely populated areas of the CoJ. Risk for seropositivity was highest in those aged 18 - 49 years (adjusted odds ratio (aOR) 1.52; 95% CI 1.13 - 2.13; p=0.0005) and in samples from diabetics (aOR 1.36; 95% CI 1.13 - 1.63; p=0.001). CONCLUSIONS: Our study conducted between the first and second waves of the pandemic shows high levels of current infection among patients attending public health facilities in Gauteng Province.

The gunshot-related injuries in trauma (GRIT) study: A profile of patients affected by gunshot-related orthopaedic injuries across South Africa.

BACKGROUND: South Africa (SA) has one of the highest gun-related mortality rates in the world - 20 people per day. The available data, however, do not reflect the substantial number of patients suffering non-lethal firearm injuries. Gunshot-related injury has been recognised as a highly costly healthcare problem by individual treating centres in SA and other countries; however, no 'national picture' has been examined in detail. OBJECTIVES: To explore the burden of gunshot-related orthopaedic injuries across SA. METHODS: A multicentre research network was established in SA, and 37 orthopaedic units across 9 provinces participated. A prospective, observational cohort study was performed during a 2-week period in 2019. Patients were screened, enrolled and reported by local orthopaedic teams. Patients were included if they had at least one acute gunshot-related orthopaedic fracture referred to the orthopaedic service. Patients were asked additional questions around baseline health-related quality-of-life (HRQOL) and personal circumstances. Follow-up was at 8 weeks after injury. RESULTS: Thirty-seven centres enrolled 135 patients over the 2-week study period. Western Cape Province had the highest number of reported cases (n=52; 39%), followed by Gauteng (n=35; 26%) and KwaZulu-Natal (n=29; 21%). The median age of patients was 30.5 years and the majority were male (89%). Forty-three percent of patients had been either shot or stabbed prior to this injury. Fifty-two percent of all patients required fracture fixation surgery and 11% required wound debridement without fracture fixation. HRQOL data were collected successfully at baseline, but follow-up data were available for <25% of cases. CONCLUSIONS: Gunshot-related orthopaedic injuries represent a significant burden of disease in the SA healthcare environment. This study highlights several areas for further research in the management of the injuries and associated outcomes.

COVID-19 and Vulnerable Populations in Sub-Saharan Africa.

The novel corona virus 2019 (COVID-19) outbreak which started in Hubei province in China has now spread to every corner of the earth. While the pandemic started later in Africa, it is now found in all African countries to varying degrees. It is thought that the prevalence and severity of disease is influenced by a number of non-communicable diseases (NCDs) which are all becoming increasingly prevalent in sub-Saharan Africa (SSA). In addition, SSA bears the major burden of human immunodeficiency virus (HIV) and tuberculosis (TB) infections. While data from Europe and the United States show that children are spared severe disease, it is uncertain if the same holds true in SSA where children suffer from sickle cell disease and malnutrition in addition to other infectious diseases. There is limited data from Africa on the effects of these conditions on COVID-19. In this review, we discuss the epidemiology of some of these conditions in Africa and the possible pathogenesis for the interactions of these with COVID-19.

Retrograde venous bullet embolism into renal vein.

SUMMARY: The unpredictable nature and behaviour of bullet emboli can pose unique diagnostic and management challenges, related to the absence of exit wounds or variable trajectories. However, embolisation into the vascular system is an extremely unusual occurrence, with fewer than 200 such cases described since 1900. Given the relative paucity of such literature reports, it is not surprising that guidelines for the optimal management of some of these emboli are neither clear cut, nor universally accepted. We report the second case of retrograde venous bullet embolism to the right renal vein following a gunshot injury to the right chest and the surgical solution.

An audit of upper gastrointestinal endoscopy performed on patients at Prince Mshiyeni Memorial Hospital in Durban, KwaZulu-Natal.

BACKGROUND: Resource constraints have resulted in upper gastrointestinal endoscopy (UGE) being deferred where possible. However, delayed investigation is costly and leads to disease progression. This study audits the UGE done at a single institution. It was motivated by the observation that public hospitals often experience an acute shortage of endoscopes, which are prone to frequent breaks and service delivery is further compromised by an increased workload. METHOD: This was a retrospective observational descriptive study of patients aged 20 to 45 years who had undergone gastrointestinal endoscopy (UGE) at Prince Mshiyeni Memorial Hospital (PMMH) in KwaZulu-Natal, during the period January 2015 to December 2015. One hundred and ninety-four patients' charts and UGE reports were reviewed. Data were analysed using SPSS Statistics version 24. The level of significance was set at p < 0.05. Variables were expressed as mean ± standard deviation or medians (interquartile range IQR) as appropriate. Mean ± standard deviation was compared using the Student's t-test. Proportions and categorical variables were compared using the Pearson's chi-square test or Fisher's exact test as appropriate. An ethical approval was obtained from the University of KwaZulu-Natal BREC (BE 447/17) and the KwaZulu-Natal Department of Health Ethics Committee. RESULTS: Epigastric pain was found to be the most common indication for UGE, with a total of 112 (57.7%) out of total of 194 patients, followed by upper gastrointestinal bleeding (UGIB) (42) (21.6%). Amongst patients presenting with epigastric pain, only 12(10.7%) patients could be confirmed that they had received acid suppression therapy prior to the testing. In the age group 20-25 years, there was a highest number of patients presenting with corrosive substance ingestion, 11 (25.0%). The commonest finding was gastritis in 99 patients (51.0%), followed by normal findings in 50 (25.7%) patients. CONCLUSION: Epigastric pain was the most common indication and gastritis was the predominant finding.

Glycated haemoglobin (HbA1c ) and fasting plasma glucose relationships in sea-level and high-altitude settings.

AIM: Higher haemoglobin levels and differences in glucose metabolism have been reported among high-altitude residents, which may influence the diagnostic performance of HbA1c . This study explores the relationship between HbA1c and fasting plasma glucose (FPG) in populations living at sea level and at an altitude of > 3000 m. METHODS: Data from 3613 Peruvian adults without a known diagnosis of diabetes from sea-level and high-altitude settings were evaluated. Linear, quadratic and cubic regression models were performed adjusting for potential confounders. Receiver operating characteristic (ROC) curves were constructed and concordance between HbA1c and FPG was assessed using a Kappa index. RESULTS: At sea level and high altitude, means were 13.5 and 16.7 g/dl (P > 0.05) for haemoglobin level; 41 and 40 mmol/mol (5.9% and 5.8%; P < 0.01) for HbA1c ; and 5.8 and 5.1 mmol/l (105 and 91.3 mg/dl; P < 0.001) for FPG, respectively. The adjusted relationship between HbA1c and FPG was quadratic at sea level and linear at high altitude. Adjusted models showed that, to predict an HbA1c value of 48 mmol/mol (6.5%), the corresponding mean FPG values at sea level and high altitude were 6.6 and 14.8 mmol/l (120 and 266 mg/dl), respectively. An HbA1c cut-off of 48 mmol/mol (6.5%) had a sensitivity for high FPG of 87.3% (95% confidence interval (95% CI) 76.5 to 94.4) at sea level and 40.9% (95% CI 20.7 to 63.6) at high altitude. CONCLUSION: The relationship between HbA1c and FPG is less clear at high altitude than at sea level. Caution is warranted when using HbA1c to diagnose diabetes mellitus in this setting.

Salivary Cortisol and Cortisone do not Appear to be Useful Biomarkers for Monitoring Hydrocortisone Replacement in Addison's Disease.

Salivary cortisol has been used to monitor hydrocortisone replacement in patients with Addison's disease (AD). Since salivary cortisol is metabolised to salivary cortisone, it may be an adjunctive analyte to assess adequacy of hydrocortisone replacement in patients with AD. We aimed to characterise the exposure of salivary cortisol and cortisone in patients and healthy controls. We measured salivary cortisol and cortisone by liquid chromatography-tandem mass spectrometry and constructed a day curve (08:00 until 24:00 h) with 16 time points in 25 AD patients taking their usual hydrocortisone dose and in 26 healthy controls. The median (interquartile range) area under the curve (AUC) for cortisol was not different for patients, compared with controls [55.63 (32.91-151.07) nmol*min*l-1 vs. 37.49 (27.41-52.00) nmol*min*l-1; p=0.098, respectively], whereas the peak cortisol Cmax was higher in patients [32.61 (5.75-146.19) nmol/l vs. 8.96 (6.96-12.23) nmol/l; p=0.013], compared with controls. The AUC for cortisone [23.65 (6.10-54.76) nmol*min*l-1 vs. 227.73 (200.10-280.52) nmol*min*l-1; p≤ 0.001, respectively], and peak cortisone Cmax was lower in patients than in controls [11.11 (2.91-35.85) nmol/l vs. 33.12 (25.97-39.95) nmol/l; p=0.002]. The AUC for salivary cortisol and salivary cortisone were not correlated with any measures of hydrocortisone dose. The time-course and AUC of salivary cortisol were similar between Addison's patients and healthy controls. Patients had substantially lower salivary cortisone AUC, compared to healthy controls. Salivary cortisol AUC and pharmacokinetics were not related to hydrocortisone dose and thus are not likely useful markers for the adequacy of hydrocortisone replacement.

A review of traumatic chylothorax.

BACKGROUND: Traumatic chylothorax is an extremely rare complication following thoracic trauma or surgery. The aetiology of traumatic chylothorax is dominated by iatrogenic causes, with a reported incidence of 0.5% to 3% following oesophageal surgery. The mortality from a chylothorax post oesophagectomy can be as high as 50%. Iatrogenic causes in total account for approximately 80% of traumatic causes. Non-iatrogenic traumatic chylothoraces are exceedingly uncommon. The complication rate in blunt thoracic trauma is said to be 0.2% to 3%, whilst in penetrating trauma, the incidence is 0.9% to 1.3%. If recognised late or managed poorly, this condition has devastating complications, including nutritional depletion, physiological derangements and immunological depression. This review revisits the anatomy of the thoracic duct, the physiology of chyle production and associated dynamics as well as the current management strategies available for traumatic chylothorax. METHODS: A review of selected English literature from 1980 to 2015 was undertaken. Databases used included Pubmed, Cochrane and Science Direct. Publications of both traumatic and postoperative chylothorax were reviewed. The appropriate literature was analysed by comparing and contrasting content with particular emphasis on management issues. Keywords and phrases were used to achieve a streamlined and focused review of the topic. CONCLUSION: Chylothorax remains a rare complication of thoracic surgery and thoracic trauma. The potential complications can result in serious morbidity and can even be fatal. Understanding the pathophysiology of a chyle leak underpins the principles of management. The overall success of conservative management ranges from 20% to 80%. The timing of surgical intervention remains debatable. Benefits of early surgical intervention are clearly documented, resulting in a gradual shift toward early operative treatment with reports suggesting thoracic duct ligation yielding a 90% success rate. Technological advances such as thoracic duct embolisation, with a potential success rate of 90%, and thoracoscopic interventions are attractive alternatives to orthodox open surgery.

Obesity risk in rural, urban and rural-to-urban migrants: prospective results of the PERU MIGRANT study.

BACKGROUND: Although migration and urbanization have been linked with higher obesity rates, especially in low-resource settings, prospective information about the magnitude of these effects is lacking. We estimated the risk of obesity and central obesity among rural subjects, rural-to-urban migrants and urban subjects. METHODS: Prospective data from the PERU MIGRANT Study were analyzed. Baseline data were collected in 2007-2008 and participants re-contacted in 2012-2013. At follow-up, outcomes were obesity and central obesity measured by body mass index and waist circumference. At baseline, the primary exposure was demographic group: rural, rural-to-urban migrant and urban. Other exposures included an assets index and educational attainment. Cumulative incidence, incidence ratio (IR) and 95% confidence intervals (95% CI) for obesity and central obesity were estimated with Poisson regression models. RESULTS: At baseline, mean age (±s.d.) was 47.9 (±12.0) years, and 53.0% were females. Rural subjects comprised 20.2% of the total sample, whereas 59.7% were rural-to-urban migrants and 20.1% were urban dwellers. A total of 3598 and 2174 person-years were analyzed for obesity and central obesity outcomes, respectively. At baseline, the prevalence of obesity and central obesity was 20.0 and 52.5%. In multivariable models, migrant and urban groups had an 8- to 9.5-fold higher IR of obesity compared with the rural group (IR migrants=8.19, 95% CI=2.72-24.67; IR urban=9.51, 95% CI=2.74-33.01). For central obesity, there was a higher IR only among the migrant group (IR=1.95; 95% CI=1.22-3.13). Assets index was associated with a higher IR of central obesity (IR top versus bottom tertile 1.45, 95% CI=1.03-2.06). CONCLUSIONS: Peruvian urban individuals and rural-to-urban migrants show a higher incidence of obesity compared with their rural counterparts. Given the ongoing urbanization occurring in middle-income countries, the rapid development of increased obesity risk by rural-to-urban migrants suggests that measures to reduce obesity should be a priority for this group.

Comparison of equations for the calculation of LDL-cholesterol in hospitalized patients.

BACKGROUND: The Friedewald equation is widely used to calculate LDL-C for cardiovascular risk prediction but is less accurate with comorbidities and extreme lipid values. Several novel formulae have been reported to outperform the Friedewald formula. METHODS: We examined 14,219 lipid profiles and evaluated four formulae (Friedewald, Chen, de Cordova, Hattori) and compared these to direct measurement of LDL-C across various triglyceride (TG), total cholesterol (TC) and HDL-cholesterol (HDL-C) ranges using Beckman reagents and instruments. Linear regression and ROC analysis were performed. RESULTS: The de Cordova formula showed a high correlation with directly measured LDL-C (r=0.90, P<0.001), comparable to the Friedewald calculated values for directly measured LDL-C (r=0.95, P<0.001). The de Cordova formula was favorable in some ranges of HDL, TC and the lowest TG range (r=0.97, P<0.001) but performed least well in comparison with the three other LDL-C calculations (AUC=0.8331), demonstrating inconsistent bias. The Chen formula performed better than Friedewald (AUC=0.9049). The Hattori formula outperformed all formulae including Friedewald over various ranges of lipid values (AUC=0.9097). CONCLUSIONS: We observe favorable correlations of the de Cordova formula with Friedewald at low TG values. However, the Hattori formula appears to be best for application in hospitalized patients, even at extreme lipid values.

Salivary cortisol day curves in Addison's disease in patients on hydrocortisone replacement.

Using salivary cortisol (SC) measurements, cortisol exposure in Addison's disease patients on hydrocortisone replacement was determined and compared with healthy controls. Cortisol pharmacokinetics was assessed in 31 patients with Addison's disease on replacement hydrocortisone doses (median daily dose 20 mg; range 5-50 mg) and 30 healthy control subjects. Saliva samples (n=16) were collected between 08:00 and 00:00 h in 1 day, using a passive drool technique. Cortisol exposure was evaluated by noncompartmental approach. In the patients, cortisol exposure was significantly higher than in controls: median inter-quartile range (IQR) peak cortisol (C(max)) 174.5 (59.3-837.0) vs. 6.50 (4.7-19.3) nmol/l, p=0.0001; area under the curve (AUC) 390.1 (177.1-928.9) vs. 21.4 (14.6-28.4) minutes*nmol/l, p=0.0001, trough cortisol level (C(min)) 0.49 (0.49-0.96) vs. 0.49 (0.49-0.49) nmol/l, p=0.02, occurring at 480.0 (0.1-660.0) vs. 405.0 (180.0-570.0) min, p=0.56. First peak cortisol was 174.5 (53.0-754.7) vs. 6.27 (3.90-8.47) nmol/l, p=0.0001 and second peak cortisol 18.90 (5.22-76.9) vs. 3.12 (1.76-4.79) nmol/l, p=0.0001. The time to first peak cortisol differed between the 2 groups, 30 (30-75) vs. 0.1 (0.1-30) minutes; p=0.0001. At doses studied, hydrocortisone replacement therapy results in cortisol pharmacokinetics being markedly different from endogenous cortisol profiles in healthy control subjects. Addison's disease patients had significantly higher SC levels compared to healthy control subjects.

Investigation of glucocorticoid receptor polymorphisms in relation to metabolic parameters in Addison's disease.

BACKGROUND: Uncertainty exists whether glucocorticoid receptor (GCR) polymorphisms play a role in steroid-related side effects in Addison's disease (AD) patients on hydrocortisone. The polymorphisms Bcll and N363S appear to increase sensitivity to cortisol, while the ER22/23EK polymorphism has been associated with resistance to cortisol. METHOD: One hundred and forty seven AD patients, and gender, and ethnicity-matched controls were recruited in South Africa. Three polymorphisms in the GCR were studied, using PCR followed by restriction fragment length analysis. Associations with BMI, lipids, glucose and inflammatory markers were investigated. RESULTS: In both patients and controls, the Bcll polymorphism occurred more frequently in whites than in other ethnic groups studied but was not associated with any of the metabolic parameters tested. The ER22/23EK polymorphism was associated with an increased BMI in both patients (29.4 vs 24.7  kg/m²) and control subjects (26.3 vs 24.2  kg/m²). The ER22/23EK polymorphism was also associated with lower LDL cholesterol in control subjects (3.46 vs 3.93  mmol/l) and in patients (3.52 vs 4.10  mmol/l). N363S was associated with increased BMI in controls 29.9  kg/m² vs wild type 24.8  kg/m². Median hydrocortisone doses were greater in patients heterozygous for either ER22/23EK 30.0  mg or N363S 25.0  mg polymorphisms than in wild type patients 20.0  mg (both comparisons). CONCLUSION: Alterations in lipids, BMI and hydrocortisone dose were associated with two polymorphisms. Further larger studies are warranted to corroborate these findings.

Plasma free fatty acid reference interval in South African neonates in the first week of life.

BACKGROUND: Non-esterified fatty acid (NEFA) levels are an important diagnostic tool in the investigation of neonatal hypoglycaemia. NEFA reference intervals have not been reported for neonates previously. METHODS: The objective of this study was to determine an NEFA reference interval for neonates. RESULTS: Heparinized plasma obtained from 106 healthy neonates in the first week of life was analysed using the Roche "Free fatty acid, Half-micro test" kit. Results were then analysed statistically for normality (Shapiro-Wilk test) and reference interval determined non-parametrically (bootstrap method). CONCLUSIONS: NEFA levels displayed a non-Gaussian distribution and the reference interval (2.5th and 97.5th percentiles) was 0.2-1.5 mmol/L (90% confidence intervals 0.1-0.3 and 1.4-2.0 mmol/L, respectively). The NEFA reference interval in South African neonates less than a week old is similar to that described in infants (1-12 months), indicating that this reference range can be used over the entire neonatal period.

Insulin Resistance Induced by Antiretroviral Drugs: Current Understanding of Molecular Mechanisms

The increase in incidence of HIV infection continues to be a major public health problem across the world; but more especially in sub- Saharan Africa. Treatment with highly active antiretroviral therapy (HAART) has improved the prognosis of patients with AIDS; but it has also increased the incidence of various metabolic disorders; in particular insulin resistance accompanied by dyslipidaemia; hyperglycaemia and lipodystrophy. This is often accompanied by frank type 2 diabetes and increased mortality from cardiovascular disease. It is important to understand the mechanistic basis for these side-effects as the incidence of these is likely to increase as the rollout of antiretroviral drugs continues

Quality of teaching in chemical pathology: ability of interns to order and interpret laboratory tests.

BACKGROUND AND OBJECTIVE: There has been a steady decline in the overt teaching of many basic and pathology sciences in the medical curriculum worldwide. As interns are the doctors most likely to request and act on tests, an assessment of their confidence in dealing with laboratory investigations was undertaken. METHODS: Interns at two hospitals in Cape Town, South Africa, were asked to complete a structured questionnaire designed to assess their confidence in ordering and interpreting a number of tests. The questionnaire also probed their desire for further teaching and the preferred delivery vehicle for such teaching. RESULTS AND CONCLUSIONS: 61 out of 117 questionnaires were returned. Interns were confident in the use of common tests, but 23% were not confident in interpreting a test that they were confident in ordering. All respondents felt they would benefit from teaching in at least one area and lectures were the preferred method, although the majority felt it very likely that they would complete an online tutorial if available. The results suggest that institutions need to devise strategies to fulfil the learning needs of new graduates in the area of chemical pathology and clinical biochemistry.

Relationship between vitamin D, calcium and parathyroid hormone in Cape Town.

AIM: The aim of this study was to test the hypothesis that vitamin D deficiency is associated with abnormal levels of calcium and parathyroid hormone (PTH). METHODS: Vitamin D requests at a tertiary hospital in South Africa over 2 years were retrospectively analysed along with calcium and PTH levels. RESULTS: Only when the 25-hydroxyvitamin D (25(OH)D) level dropped below 25 nmol/l, was there a significant rise in PTH. A subnormal 25(OH)D level was also not always related to hypocalcaemia, as more than half of patients with their 25(OH)D level below 25 nmol/l had calcium levels in the reference range. However, all patients with calcium levels below 1.8 mmol/l were shown to have vitamin D insufficiency. CONCLUSION: Hypovitaminosis D may co-exist with a blunted PTH response. Therefore, assumptions about vitamin D status should not be made based on PTH and calcium values. 25(OH)D measurements should be requested when vitamin D deficiency is clinically suspected, irrespective of biochemical results.