SUNScholar - Browsing by Author "Erasmus, R. T."

Browsing by Author "Erasmus, R. T."

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Electrophoresis test prevalence, requesting patterns, yield and related bone marrow biopsy findings at a South African tertiary hospital : a 5-year retrospective audit
(Health and Medical Publishing Group, 2017) Naidoo, N.; Erasmus, R. T.; Grewal, R.; Zemlin, A. E.
Background. Studies of electrophoresis testing (serum protein electrophoresis (SPE), urine protein electrophoresis (UPE), immunofixation electrophoresis (IFE)) in a South African (SA) pathology laboratory setting are limited. Objectives. To evaluate the prevalence, testing pattern and yield of electrophoresis tests performed over a 5-year period in a tertiary academic laboratory and to relate these findings to bone marrow biopsy findings in a few selected cases. Methods. This was a retrospective audit of all SPE, UPE and IFE tests performed on new and follow-up adult patients (aged ≥18 years) from 2010 to 2015, using data from the Tygerberg Academic Hospital (Cape Town, SA) National Health Laboratory Service hospital information system database. A subgroup analysis of all patients with negative serum (SIFE) and/or urine immunofixation (UIFE) tests who had concurrent bone marrow biopsies close to the time of IFE testing was also performed. Results. A total of 5 086 SPE tests were performed (44.3% were follow-up tests, and of these patients 13.8% had SIFE tests); 1 299 UPE tests were performed (23.3% were follow-up tests, and of these patients 33.6% had UIFE tests). The mean ages of patients who had SIFE and UIFE tests were 59 years (standard deviation (SD) 14.2) and 60 years (SD 15), respectively. The female-to-male ratio was 1.1:1 for both SIFE and UIFE. The negative test yields for SIFE and UIFE were 31.3% and 52.1%, respectively. Bone marrow biopsy findings for patients with negative SIFE tests identified 8 out of the 20 biopsies (40.0%) as positive for myeloma. Conclusion. This audit provides baseline data on the prevalence of test requests, their source and the yield of electrophoresis testing in our laboratory. An increasing trend in SIFE and UIFE was evident.
Erythrocyte membrane fatty acids in patients with multiple sclerosis
(2009) Hon, G. M.; Hassan, M. S.; Van Rensburg, S. J.; Abel, S.; Marais, D. W.; Van Jaarsveld, P.; Smuts, C. M.; Henning, F.; Erasmus, R. T.; Matsha, T.
Background: Reports on fatty acids levels in multiple sclerosis remain inconclusive. Objective: To determine the erythrocyte membrane fatty acid levels in multiple sclerosis patients and correlate with Kurtzke Expanded Disability Status Scale. Methods: Fatty acid composition of 31 multiple sclerosis and 30 control individuals were measured by gas chromatography. Results: The membrane phosphatidylcholine C20:4 n-6 concentration was lower in the multiple sclerosis patients when compared to that of the control group, P = 0.04 and it correlated inversely with the EDSS and FSS. Conclusion: Decrease in C20:4 n-6 in the erythrocyte membrane could be an indication of depleted plasma stores, and a reflection of disease severity.
Gas chromatography results interpretation: Absolute amounts versus relative percentages
(InTech, 2012) Hon, G. M.; Abel, S.; Smuts, C. M.; van Jaarsveld, P.; Hassan, S.; Janse van Rensburg, S.; Erasmus, R. T.; Matsha, T. E.
The impact of COVID-19 on routine patient care from a laboratory perspective
(Health & Medical Publishing Group, 2020-11-05) Kruger, E. C.; Banderker, R.; Erasmus, R. T.; Zemlin, A. E.
Background. Globally, few studies have examined the effect of the COVID-19 pandemic on routine patient care and follow-up. Objectives. To evaluate the effect of the COVID-19 response on biochemical test requests received from outpatient departments (OPDs) and peripheral clinics serviced by the National Health Laboratory Service Chemical Pathology Laboratory at Tygerberg Hospital, Cape Town, South Africa (SA). Request volumes were used as a measure of the routine care of patients, as clinical information was not readily available. Methods. A retrospective audit was conducted. The numbers of requests received from OPDs and peripheral clinics for creatinine, glycated haemoglobin (HbA1c), lipid profiles, thyroid-stimulating hormone (TSH), free thyroxine, free tri-iodothyronine (fT3), serum and urine protein electrophoresis, serum free light chains and neonatal total serum bilirubin were obtained from 1 March to 30 June for 2017, 2018, 2019 and 2020. Results. The biggest impact was seen on lipids, creatinine, HbA1c, TSH and fT3. The percentage reduction between 1 March and 30 June 2019 and between 1 March and 30 June 2020 was 59% for lipids, 64% for creatinine and HbA1c, 80% for TSH and 81% for fT3. There was a noteworthy decrease in overall analyte testing from March to April 2020, coinciding with initiation of level 5 lockdown. Although an increase in testing was observed during June 2020, the number of requests was still lower than in June 2019. Conclusions. This study, focusing on the short-term consequences of the SA response to the COVID-19 pandemic, found that routine follow-up of patients with communicable and non-communicable diseases was affected. Future studies are necessary to evaluate the long-term consequences of the pandemic for these patient groups.
Increase in blood pressure over a 7-year period in a mixed-ancestry South African population
(Health & Medical Publishing Group, 2019) Davids, S. F. G.; Matsha, T. E.; Peer, N.; Erasmus, R. T.; Kengne, A. P.
Background. An increase in the prevalence of high blood pressure (BP) has been reported globally and in the South African (SA) population. Objectives. To investigate temporal changes in absolute BP levels and hypertension prevalence in the mixed-ancestry South Africans. Methods. Participants were from two independent cross-sectional surveys conducted during 2008/09 (N=928) and 2014/16 (N=1 969) in Bellville South, Cape Town, SA. Participants’ eligibility was based on several criteria, including age >20 years and neither bedridden nor pregnant. Data were obtained by administered questionnaires, clinical measurements (BP and anthropometry) and biochemical assessments (oral glucose tolerance tests and cotinine levels). Known hypertension was based on a self-reported history of doctor-diagnosed hypertension and ongoing treatment. Comparison across years was based on the crude prevalence of hypertension as well as direct age-standardised prevalence, based on the SA 2011 mixed-ancestry population distribution, in 10-year age increments. Results. In all, 708 participants (76.3%) in 2008/09 and 1 488 (75.6%) in 2014/16 were female. Between 2008/09 and 2014/16, mean systolic BP increased from 124 to 136 mmHg (absolute mean difference 15 mmHg) and mean diastolic BP from 75 to 85 mmHg (absolute mean difference 9 mmHg) in the overall sample. The prevalence of screen-detected hypertension increased from 11.6% to 24.8%, with a similar increase in males and females, while the prevalence of known cases remained stable. These changes remained significant after adjustment for age and gender. Conclusions. A rightward shift in absolute BP translated into a significant increase in the prevalence of hypertension over time in this population. The predominant increases in screen-detected hypertension suggest that the deteriorating profile was not matched by efforts to detect and manage individuals with higher-than-optimal BP levels.
Indices of paraoxonase and oxidative status do not enhance the prediction of subclinical cardiovascular disease in mixed-ancestry South Africans
(Hindawi Publishing Corporation, 2014-03-27) Macharia, M.; Kengne, A. P.; Blackhurst, D. M.; Erasmus, R. T.; Hoffmann, M.; Matsha, T. E.
We evaluated the association of indices of paraoxonase (PON1) and oxidative status with subclinical cardiovascular disease (CVD) in mixed-ancestry South Africans. Participantswere 491 adults (126 men)whowere stratified by diabetes status and bodymass index (BMI). Carotid intima-media thickness (CIMT) was used as a measure of subclinical CVD. Indices of PON1 and oxidative status were determined by measuring levels and activities (paraoxonase and arylesterase) of PON1, antioxidant activity (ferric reducing antioxidant power and trolox equivalent antioxidant capacity), and lipid peroxidation markers (malondialdehyde and oxidized LDL). Diabetic subjects (28.9%) displayed a significant decrease in PON1 status and antioxidant activity as well as increase in oxidized LDL and malondialdehyde. A similar profile was apparent across increasing BMI categories. CIMT was higher in diabetic than nondiabetic subjects (P < 0.0001) but showed no variation across BMI categories. Overall, CIMT correlated negatively with indices of antioxidant activity and positivelywithmeasures of lipid oxidation. Sex, age, BMI, and diabetes altogether explained 29.2% of CIMT,with no further improvement fromadding PON1 and/or antioxidant status indices.Though indices of PON1 and oxidative status correlate with CIMT, their measurements may not be useful for identifying subjects at high CVD risk in this population.
Monounsaturated fatty acids in blood cell membranes from patients with multiple sclerosis
(2011) Hon, G. M.; Hassan, M. S.; Van Rensburg, S. J.; Abel, S.; Erasmus, R. T.; Matsha, T.
The aim of this study was to investigate whether blood cell membrane monounsaturated fatty acids were associated with inflammation and disease outcome in patients with multiple sclerosis. The fatty acid composition in peripheral blood mononuclear cell and red blood cell membranes from 26 patients and 25 controls were determined by gas chromatography. Results showed positive associations between C-reactive protein and C16:1n-7, C18:1n-7, and C24:1n-9 in membranes from controls only. In general, C18:1n-9 and C20:1n-9 showed inverse correlations, while C16:1n-7 and C18:1n-7 showed positive correlations with disease outcome. Multiple sclerosis has a known inflammatory component. There is scarcity of literature on the role of monounsaturated fatty acids in inflammation, but results from this study suggested an association in healthy subjects between monounsaturated fatty acids and C-reactive protein, even at physiologically low levels. This association was not found in the plasma from patients. Furthermore, the n-9 and n-7 fatty acids played different roles in disease outcome, and therefore warrant inclusion, together with polyunsaturated fatty acids when investigating the inflammatory aspects of the disease.
Negative association of MC3R variants with weight and blood pressure in Cape Town pupils aged 11 - 16 years
(Health and Medical Publishing Group (HMPG), 2011-06) Yako, Y. Y.; Fanampe, B. L.; Hassan, S. M.; Erasmus, R. T.; Van der Merwe, L.; Matsha, T. E.
Background. Human and animal studies support the role of MC4R and MC3R in human obesity, but limited data are available on the genetic contribution to obesity in South African populations. Objective. To screen obese-overweight South African pupils for MC3R and MC4R polymorphisms that may play a role in the development of obesity. Design. A cross-sectional study screened 227 obese-overweight (115 black and 112 coloured) and 204 normal weight (94 black, 110 coloured) school pupils for the presence of MC4R and MC3R polymorphisms using a single strand conformation polymorphism, subsequent sequencing, and allele specific restriction enzyme analysis. Results. Two polymorphisms were detected in the MC3R (T6K and V81I) but none in MC4R. After adjusting for age, gender and case-control status, the frequency distributions of T6K and V81I genotype and allele varied significantly between the ethnic groups. The frequency of the V81I A allele was significantly lower in coloured overweight-obesity than normal pupils. In coloured pupils, both polymorphisms were associated with obesity indices and total cholesterol. The T6K A allele was also associated with lower blood pressure. Likewise, different T6K-V81I haplotypes demonstrated negative associations with obesity indices and blood pressure. Conclusion. We demonstrated that the MC3R polymorphisms have a protective effect on metabolic traits; however, further analysis is required to confirm whether this translates to a lower incidence of metabolic syndrome in coloured populations.
Non-esterified fatty acids in blood cell membranes from patients with multiple sclerosis
(2012) Hon, G. M.; Hassan, M. S.; Van Rensburg, S. J.; Abel, S.; Erasmus, R. T.; Matsha, T.
The literature on non-esterified fatty acid (NEFA) concentrations in blood cell membranes from patients with multiple sclerosis (MS) is scarce and reports on concentrations in brain tissue from these patients are inconsistent. NEFAs are needed for several biological functions, for example, as precursors for inflammatory eicosanoid synthesis. The objective of this study was therefore to compare NEFA concentrations in blood cell membranes from patients with that of healthy control subjects, and to correlate possible changes with disease outcome. NEFA C18:2n-6 (9,12-octadecadienoic acid) was decreased in peripheral blood mononuclear cell membranes from patients, median (quartile range): patients: 0.05 (0.02) and controls: 0.07 (0.14)μg/mg protein, p=0.007. C18:2n-6 also showed a weaker relationship with other fatty acids: with C16:0: patients: R=0.40, p=0.04; controls: R=0.82, p=0.000001. Saturated and MUFA showed positive correlations with the Bowel and bladder Functional System Scores (FSS). In contrast, in red blood cell membranes C18:2n-6 and C22:0 (docosanoic acid) showed inverse correlations with the Sensory and Brainstem FSS. The decrease in NEFA C18:2n-6 resulted in metabolic abnormalities between itself and saturated and monounsaturated NEFAs. Altered fatty acid composition in immune cell membranes would influence immune cell functions, and could possibly have contributed to the positive correlations between these fatty acids and disease outcome. © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
Paraoxonase 1 genetic polymorphisms in a mixed ancestry African population
(Hindawi Publishing Corporation, 2014-11-16) Macharia, M.; Kengne, A. P.; Blackhurst, D. M.; Erasmus, R. T.; Matsha, T. E.
Paraoxonase 1 (PON1) activity is markedly influenced by coding polymorphisms, Q/R at position 192 and M/L at position 55 of the PON1 gene. We investigated the frequencies of these polymorphisms and their effects on PON1 and antioxidant activities in 844 South African mixed ancestry individuals. Genotyping was done using allele-specific TaqMan technology, PON1 activities were measured using paraoxon and phenylacetate, oxidative status was determined by measuring the antioxidant activities of ferric reducing antioxidant power and trolox equivalent antioxidant capacity, and lipid peroxidation markers included malondialdehyde and oxidized LDL. The frequencies of Q192R and L55Mwere 47.6% and 28.8%, respectively, and the most common corresponding alleles were 192R (60.4%) and 55M (82.6%).The Q192 was significantly associated with 5.8 units’ increase in PON1 concentration and 15.4 units’ decrease in PONase activity after adjustment for age, sex, BMI, and diabetes, with suggestion of differential effects by diabetes status.The PON1 L55 variant was associated with none of the measured indices. In conclusion, we have shown that the Q192R polymorphism is a determinant of both PON1 concentration and activity and this association appeared to be enhanced in subjects with diabetes.
Peripheral blood mononuclear cell membrane fluidity and disease outcome in patients with multiple sclerosis
(2012) Hon, G. M.; Hassan, M. S.; Van Rensburg, S. J.; Abel, S.; Erasmus, R. T.; Matsha, T.
Immune cell membrane lipids are important determinants of membrane fluidity, eicosanoid production and phagocytosis and fatty acid metabolic abnormalities have been reported in immune cells from patients with multiple sclerosis. The aim of this study was to investigate the relationship between peripheral blood mononuclear cell membrane fluidity, permeability status, and disease outcome as measured by the Kurtzke expanded disability status scale. Phospholipids, fatty acids and cholesterol composition in peripheral blood mononuclear cells from 26 patients diagnosed with multiple sclerosis and 25 healthy control subjects were determined by colorimetric assay, gas chromatography and enzymatic assays, respectively. Membrane fluidity was calculated according to previously established formulae and correlated with C-reactive protein and the Kurtzke expanded disability status scale. There were no significant differences in membrane lipids in peripheral blood mononuclear cells from patients and controls. However, correlation studies showed lipid metabolic abnormalities, which were reflected in significant correlations between membrane fluidity as measured by both its fatty acid and phospholipid compositions, and the functional system scores. C-reactive protein showed positive correlations with phosphatidylcholine, phosphatidylserine, phosphatidylinositol and total phospholipids in membranes from control subjects. Metabolic abnormalities, as well as correlations between membrane fluidity and the functional system scores, suggested the involvement of these immune cell membranes in the disease progression. Furthermore, the changed relationship between membrane phospholipids and C-reactive protein, which has been shown to correlate with infectious episodes and clinical relapse, could be an indication of immune cell dysfunction in patients with multiple sclerosis. © 2011 Indian Society of Haematology & Transfusion Medicine.
Plasma non-esterified fatty acids in patients with multiple sclerosis
(2011) Hon, G. M.; Hassan, M. S.; Van Rensburg, S. J.; Abel, S.; Erasmus, R. T.; Matsha, T.
Self-induced vomiting : risk for oesophageal cancer?
(Health & Medical Publishing Group, 2006-03) Matsha, T.; Stepien, A.; Blanco-Blanco, E.; Brink, L. T.; Lombard, C. J.; Van Rensburg, S.; Erasmus, R. T.
Background. Chronic inflammation of the oesophagus is considered a precursor condition for the development of oesophageal cancer. Identification of the causes of chronic oesophageal irritation is therefore relevant in developing preventive measures. Self-induced vomiting is a cultural practice among the black population of South Africa, particularly those living in the Transkei, a region reported to have one of the highest incidences of oesophageal cancer worldwide. Methods. We retrospectively examined the association between the practice of self-induced vomiting and the development of cytological features of inflammation in 478 self-selected subjects living in Transkei who underwent early screening for oesophageal cancer. Screening involved brush biopsy, cytological investigation and a questionnaire interview. Results. The prevalence of self-induced vomiting was 80.5% and 79.1% in males and females, respectively, and this was stable across all ages. Furthermore, self-induced vomiting was found to be significantly and independently associated with oesophageal chronic inflammation (odds ratio 1.83, 95% confidence interval: 1.13 - 2.96, p = 0.013). Conclusion. While the association between the cultural practice of self-induced vomiting and oesophageal cancer has previously been hypothesised, this is the first study to report on an association between this practice and oesophageal chronic inflammation. Further studies that take into account the method used, frequency and duration of vomiting, age of commencement and fasting state of subjects practising self-induced vomiting coupled with accurate indicators of inflammation are needed to elucidate the role of self-induced vomiting in oesophageal pathogenesis.

Browsing by Author "Erasmus, R. T."

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