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In this work, Chemical Vapour Deposition (CVD) has been used to synthesize boron nitride (BN) nanostructures, particularly nanotubes, and selectively introduce defects into the lattice of the synthesized BN nanostructures through ion implantation. Scanning electron microscopy (SEM) images show clear evidence of BN nanostructures and BN nanotubes (BNNTs), with the latter appearing as long, thin structures with diameters ranging from â30-80 nm. Raman analysis show an E2g mode of vibration assigned to hexagonal BN (h-BN) at 1366 cm-1 after ion implantation, with increased intensity. Grazing incidence X-ray diffraction (GIXRD) spectra revealed a prominent peak between 54 and 56°, corresponding to the (004) h-BN reflection, which was used to determine the average lattice parameter câ0.662 nm representing the stacking direction of the BN layers. The majority of the samples had broad peaks, indicative of a nanocrystalline material. The only exception was the sample grown at 1200 °C, which was found to have a Scherrer crystallite size >100 nm. In contrast, the rest of the samples had an average size of 3.5 nm. Notable observations in this study include a significant rise in the size of the Raman derived crystallite domains in the nanostructures synthesized at 1100 and 1200 °C after ion implantation with boron ions at fluence 5 × 1014 ions/cm2.
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Background: The second wave of coronavirus disease 2019 (COVID-19), dominated by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) Beta variant, has been reported to be associated with increased severity in South Africa (SA). Objectives: To describe and compare clinical characteristics, management and outcomes of COVID-19 patients admitted to an intensive care unit (ICU) in SA during the first and second waves. Methods: In a prospective, single-centre, descriptive study, we compared all patients with severe COVID-19 admitted to ICU during the first and second waves. The primary outcomes assessed were ICU mortality and ICU length of stay (LOS). Results: In 490 patients with comparable ages and comorbidities, no difference in mortality was demonstrated during the second compared with the first wave (65.9% v. 62.5%, p=0.57). ICU LOS was longer in the second wave (10 v. 6 days, p<0.001). More female admissions (67.1% v. 44.6%, p<0.001) and a greater proportion of patients were managed with invasive mechanical ventilation than with non-invasive respiratory support (39.0% v. 14%, p<0.001) in the second wave. Conclusion: While clinical characteristics were comparable between the two waves, a higher proportion of patients was invasively ventilated and ICU stay was longer in the second. ICU mortality was unchanged.
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Disturbances in the oral microbiome are associated with periodontal disease initiation and progression and diabetes mellitus (DM), but how this contributes to the cause-and-effect relationship between periodontal disease and DM is poorly understood. We examined the bacterial composition in plaque samples from 128 South Africans with periodontal disease across glycemic statuses using 16S rDNA sequencing of regions 2, 3, 4, 6-7, 8, and 9. Of the 9 phyla identified, Firmicutes, Proteobacteria, Bacteroidetes, Fusobacteria, and Actinobacteria made up >98%. Fusobacteria and Actinobacteria were significantly more abundant in subjects with diabetes, while Proteobacteria were less abundant. However, in the presence of gingival bleeding and DM, as compared with DM without gingival bleeding, Actinobacteria were markedly reduced while Bacteroidetes were more abundant. In contrast, no differences in Actinobacteria or Bacteroidetes abundance were observed between DM with and without pocket depth (PD) ≥4 mm. At the genus level, similar changes in relative abundance were observed in the presence of DM and periodontal disease. Our findings remained in conditional logistic regression models adjusted for age, sex, waist circumference, and the 5 most dominant phyla. For example, Actinobacteria significantly increased the odds of diabetes by 10% in subjects with gingival bleeding, while Fusobacteria increased this odd by 14%; yet, among subjects with PD ≥4 mm, Fusobacteria decreased the odds of DM by 47%. Our findings have confirmed the alterations in the composition of the oral microbiota across glycemic statuses as well as different stages of periodontal disease. However, it is not clear whether these differences were the consequence of hyperglycemia or the presence of periodontal diseases. Therefore, we recommend further investigations in a longitudinal study design.
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Diabetes Mellitus , Microbiota , Enfermedades Periodontales , Fusobacterias , Humanos , Estudios Longitudinales , Boca , Enfermedades Periodontales/complicaciones , ARN Ribosómico 16S/genéticaRESUMEN
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.
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COVID-19 , Servicios de Laboratorio Clínico/tendencias , Técnicas de Laboratorio Clínico/tendencias , Atención a la Salud , Atención Ambulatoria , Bilirrubina/sangre , Análisis Químico de la Sangre/tendencias , Electroforesis de las Proteínas Sanguíneas , Creatinina/sangre , Electroforesis/tendencias , Hemoglobina Glucada/metabolismo , Humanos , Lípidos/sangre , Estudios Retrospectivos , SARS-CoV-2 , Pruebas de Función de la Tiroides/estadística & datos numéricos , Tirotropina/sangre , Tiroxina/sangre , Triyodotironina/sangre , Urinálisis/tendenciasRESUMEN
Small-dense low density lipoprotein (sdLDL) is increasingly viewed as a marker for evaluating atherogenic risk, however its clinical uptake is hampered by the cumbersomeness of available methods. Consequently, a number of alternative methods for the estimation of sdLDL have been developed and none have been tested in a population from Africa. We evaluated an equation to estimate sdLDL-C from classic lipid parameters in South Africans. This is a cross-sectional study involving 1550 participants in which direct measurement of sdLDL in 237 participants was performed using a homogeneous enzymatic assay. Their mean age (standard deviation, SD) was 54.2 (14.7) years. 156 (65.8%) were normotolerant, 29 (12.2%) prediabetes, 17 (7.2%) screen detected diabetes and 35 (14.8%) known diabetes. Measured sdLDL values ranged from 0.17 to 3.39 versus-1.85 to 2.52 mmol/L calculated sdLDL. There was a significant positive correlation between the two measurements with a Pearson correlation coefficient of 0.659 (95%CI: 0.581-0.726). In a regression model, the adjusted R2 was 0.440 after adding age, 0.441 after further adding gender, then 0.443 with dysglycemia and lastly 0.447 upon adding body mass index. With the exception of HDL-cholesterol levels that decreased across increasing quintiles of calculated sdLDL, our data showed significant correlations between sdLDL and cardiometabolic risk factors, all p values < 0.0001. In conclusion, this study has shown that calculated sdLDL can be efficiently used to approximate population levels of sdLDL; however the modest correlation indicate that at the individual level, it will poorly approximate true sdLDL levels, with possible implications for risk stratification.
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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=1â969) 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.
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Presión Sanguínea , Hipertensión/epidemiología , Factores de Edad , Consumo de Bebidas Alcohólicas/epidemiología , Población Negra , Índice de Masa Corporal , Estudios Transversales , Escolaridad , Femenino , Intolerancia a la Glucosa/epidemiología , Humanos , Masculino , Persona de Mediana Edad , Prevalencia , Factores Sexuales , Fumadores/estadística & datos numéricos , Sudáfrica/epidemiología , Circunferencia de la Cintura , Población BlancaRESUMEN
Diabetes mellitus (DM) has reached epidemic proportions across the globe with the largest increases seen in sub-Saharan Africa. Those that are diagnosed are largely poorly controlled. This review summarizes the limitations of the use of glycated haemoglobin (HBA1c) in Africa and current knowledge on the utility of glycated albumin and fructosamine in African patients. The diagnosis and monitoring of DM in African patients may be compromised by associated conditions like sickle cell anaemia, chronic kidney disease and HIV infection. Glycated albumin reflects short term glycaemia and is not affected by many conditions that alter HbA1c. It can be measured enzymatically, and this review discusses methods for analysis, and discusses the advantages and limitations in specific situations with an emphasis on conditions that also affect HbA1c.
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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.
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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 â¥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
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Médula Ósea , Auditoría Clínica , Electroforesis , Prevalencia , Sudáfrica , Centros de Atención TerciariaRESUMEN
BACKGROUND: Diabetes mellitus contributes significantly to the burden of disease in South Africa (SA). Monitoring of glycaemic control with glycosylated haemoglobin (HbA1c) is recommended, even though current laboratory-based testing does not support immediate clinical decision-making. OBJECTIVES: To evaluate the costs and consequences for quality of care by introducing point-of-care (POC) testing for HbA1c for patients with type 2 diabetes at community health centres in Cape Town, SA. METHODS: A quasi-experimental study was conducted at two control and two intervention sites in the same sub-district. The DCA Vantage Analyzer (Siemens, Germany) for POC testing was introduced at the intervention sites for 12 months. Patients were randomly selected from the diabetes register at the intervention (n=300) and control (n=300) sites, respectively, and data were collected from patient records at baseline and 12 months. Focus group interviews were performed at the intervention sites. Technical quality and cost implications were evaluated. RESULTS: POC testing was feasible, easy to integrate into the organisation of care, resulted in more immediate feedback to patients (p<0.001) and patients appeared more satisfied. POC testing did not improve test coverage, treatment intensification, counselling or glycaemic control. There was an incremental cost of ZAR2 110 per 100 tests. Compliance with quality control was poor, although control tests showed good reliability. CONCLUSION: This study does not support the introduction of POC testing for HbA1c in public sector primary care practice in the current context. POC testing should be evaluated further in combination with interventions to overcome clinical inertia and strengthen primary healthcare.
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Obesity is increasing in Africa, but the underlying genetic background largely remains unknown. We assessed existing evidence on genetic determinants of obesity among populations within Africa. MEDLINE and EMBASE were searched and the bibliographies of retrieved articles were examined. Included studies had to report on the association of a genetic marker with obesity indices and the presence/occurrence of obesity/obesity trait. Data were extracted on study design and characteristics, genetic determinants and effect estimates of associations with obesity indices. According to this data, over 300 polymorphisms in 42 genes have been studied in various population groups within Africa mostly through the candidate gene approach. Polymorphisms in genes such as ACE, ADIPOQ, ADRB2, AGRP, AR, CAPN10, CD36, C7orf31, DRD4, FTO, MC3R, MC4R, SGIP1 and LEP were found to be associated with various measures of obesity. Of the 36 polymorphisms previously validated by genome-wide association studies (GWAS) elsewhere, only FTO and MC4R polymorphisms showed significant associations with obesity in black South Africans, Nigerians and Ghanaians. However, these data are insufficient to establish the true nature of genetic susceptibility to obesity in populations within Africa. There has been recent progress in describing the genetic architecture of obesity among populations within Africa. This effort needs to be sustained via GWAS studies.
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Población Negra/genética , Predisposición Genética a la Enfermedad/genética , Estudio de Asociación del Genoma Completo , Obesidad/genética , Proteínas/genética , África/epidemiología , Dioxigenasa FTO Dependiente de Alfa-Cetoglutarato , Índice de Masa Corporal , Predisposición Genética a la Enfermedad/epidemiología , Humanos , Obesidad/epidemiología , Fenotipo , Polimorfismo GenéticoRESUMEN
OBJECTIVES: To assess changes in body mass and metabolic profiles in patients with first-episode schizophrenia receiving standardised, assured treatment and to identify predictors and moderators of the effects. METHODS: We investigated the changes in body mass, fasting blood glucose and lipids in 107 largely antipsychotic naïve, first-episode schizophrenia patients who were treated according to a standard algorithm with long-acting injectable flupenthixol decanoate over 12 months. RESULTS: Eighty-three (78%) participants completed the 12 months of treatment, and 104 (97%) received 100% of the prescribed injections during their participation. There were significant increases in BMI (P<.0001), waist circumference (P=0.0006) and triglycerides (P=0.03) and decrease in HDL (P=0.005), while systolic (P=0.7) and diastolic blood pressure (P=0.8), LDL (P=0.1), cholesterol (P=0.3), and glucose (P=0.9) values did not change over time. The triglyceride: HDL ratio increased by 91%. Change in BMI was only correlated with change in triglycerides (P=.008). The only significant predictor of BMI increase was non-substance abuse (P=.002). CONCLUSIONS: The risks of weight gain and metabolic syndrome associated with antipsychotic treatment in first-episode schizophrenia are not restricted to second generation antipsychotics. This is a global problem, and developing communities may be particularly susceptible.
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Antipsicóticos/administración & dosificación , Antipsicóticos/efectos adversos , Glucemia/metabolismo , Índice de Masa Corporal , Colesterol/sangre , Flupentixol/análogos & derivados , Síndrome Metabólico/inducido químicamente , Esquizofrenia/tratamiento farmacológico , Triglicéridos/sangre , Adulto , Biomarcadores/sangre , Estudios de Cohortes , Femenino , Flupentixol/administración & dosificación , Flupentixol/efectos adversos , Humanos , Masculino , Síndrome Metabólico/sangre , Metaboloma , Esquizofrenia/sangre , Sudáfrica , Aumento de Peso/efectos de los fármacosRESUMEN
Early-onset type 2 diabetes is regarded as disease occurring before the age of 40 years. It is well described, and increasing in prevalence, but there is little information from Africa. We therefore assessed the prevalence of early-onset type 2 diabetes in Nairobi, Kenya; and investigated its association with family history. Of 140 patients with type 2 diabetes, 33 (24%) had an early onset. There was a positive family history of diabetes in 85% of those with early onset, compared with 56% of those with usual onset (p=0.009). This suggests that relatives of those with early-onset type 2 diabetes should have regular diabetes screening
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/epidemiología , Diabetes Mellitus/genética , Kenia , AnamnesisRESUMEN
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 L55M were 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.
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Arildialquilfosfatasa/genética , Polimorfismo Genético , Adulto , Anciano , Arildialquilfosfatasa/sangre , Diabetes Mellitus/enzimología , Diabetes Mellitus/genética , Femenino , Frecuencia de los Genes , Humanos , Masculino , Persona de Mediana Edad , Estrés Oxidativo , SudáfricaRESUMEN
Background. Genetic variants in the nuclear transcription receptor, PPARG, are associated with cardiometabolic traits, but reports remain conflicting. We determined the frequency and the clinical relevance of PPARG SNPs in an African mixed ancestry population. Methods. In a cross-sectional study, 820 participants were genotyped for rs1800571, rs72551362, rs72551363, rs72551364, and rs3856806, using allele-specific TaqMan technology. The homeostatic model assessment of insulin (HOMA-IR), ß-cells function (HOMA-B%), fasting insulin resistance index (FIRI), and the quantitative insulin-sensitivity check index (QUICKI) were calculated. Results. No sequence variants were found except for the rs3856806. The frequency of the PPARG-His447His variant was 23.8% in the overall population group, with no difference by diabetes status (P = 0.215). The His447His allele T was associated with none of the markers of insulin resistance overall and by diabetes status. In models adjusted for 2-hour insulin, the T allele was associated with lower prevalent diabetes risk (odds ratio 0.56 (95% CI 0.31-0.95)). Conclusion. Our study confirms the almost zero occurrences of known rare PPARG SNPs and has shown for the first time in an African population that one of the common SNPs, His447His, may be protective against type 2 diabetes.
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BACKGROUND: South Africa has the highest burden of tuberculosis (TB) in the World Health Organization (WHO) African region. Using traditional TB diagnostic tools, the diagnosis of pleural TB (PTB) is highly unrewarding. Elevated levels of pleural fluid adenosine deaminase (FADA) have been shown to be useful in the diagnosis of PTB; however, similar levels may be found in some other medical conditions leading to misdiagnosis. Following queries from clinicians concerning the likely high false-positive (FP) rate of FADA from our laboratory, we performed a retrospective audit of all high FADA results generated over a 12-month period. OBJECTIVES: To determine the positive predictive value (PPV) of FADA, the frequent causes of FPs in our laboratory and the demographic characteristics of tuberculous pleural effusions (TPEs) and non-tuberculous pleural effusions (NTPEs). METHODS: High FADA results generated in the past year were extracted with corresponding TB culture results, fluid cell count, cytology/ histology results, radiology reports and HIV results. Hospital records were reviewed for the final diagnosis in each case. Diagnosis of PTB was based on the WHO case definition of TB. RESULTS: A total of 159 results were reviewed: 133 (83.6%) were TPE, hence FADA had a PPV of 83.6%. Neoplasm was the most common cause of an FP in 13/26 (50%) NTPEs. While TPE was more common than NTPE in younger people, both groups had an equal gender distribution. CONCLUSION: FADA had a high PPV for PTB in our laboratory. We recommend its continued use as a rapid and reliable diagnostic tool for PTB.
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Adenosina Desaminasa/análisis , Costo de Enfermedad , Infecciones por VIH/complicaciones , Derrame Pleural/enzimología , Tuberculosis Pleural/diagnóstico , Adulto , Reacciones Falso Positivas , Femenino , Humanos , Renta , Masculino , Auditoría Médica , Estudios Retrospectivos , SudáfricaRESUMEN
We evaluated the association of indices of paraoxonase (PON1) and oxidative status with subclinical cardiovascular disease (CVD) in mixed-ancestry South Africans. Participants were 491 adults (126 men) who were stratified by diabetes status and body mass 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 positively with measures of lipid oxidation. Sex, age, BMI, and diabetes altogether explained 29.2% of CIMT, with no further improvement from adding 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.
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Arildialquilfosfatasa/metabolismo , Enfermedades Cardiovasculares/metabolismo , Estrés Oxidativo , Adulto , Anciano , Antioxidantes/química , Antioxidantes/metabolismo , Población Negra , Índice de Masa Corporal , Hidrolasas de Éster Carboxílico/metabolismo , Enfermedades Cardiovasculares/enzimología , Enfermedades Cardiovasculares/patología , Grosor Intima-Media Carotídeo , Diabetes Mellitus Tipo 2/diagnóstico , Humanos , Lipoproteínas LDL/sangre , Masculino , Malondialdehído/sangre , Persona de Mediana Edad , Factores de Riesgo , SudáfricaRESUMEN
AIMS: To determine the phenotypes associated with progression to type 2 diabetes or worsening in glucose tolerance during a 3-year follow-up of a community-based cohort in Cape Town, South Africa. METHODS: A total of 198 eligible subjects (72.3% women) aged 55.2 years, from the Bellville-South community were followed-up between 2008 and 2011. Baseline and follow-up data collections included glucose tolerance status, anthropometric, blood pressure, lipids, insulin, γ-glutamyltransferase, cotinine, creatinine and HbA1c. Progression in glucose tolerance status at 3-year was the composite of new-onset diabetes and any worsening in glucose tolerance status. RESULTS: The cumulative incidence of progression in glucose tolerance status was: 16.2% (32 participants including 11 with new-onset diabetes), and increased in a stepwise fashion with the number of components of metabolic syndrome (MetS). In age and sex-adjusted logistic regression analyses, MetS [odd ratio: 3.08 (95% CI: 1.34-7.10)], HbA1c [5.26 (1.94-14.24)], HDL-cholesterol [0.05 (0.01-0.33)], γ-glutamyltransferase [1.99 (1.07-3.67)], triglycerides [1.71 (1.13-2.58)] and total/HDL-cholesterol [1.45 (1.08-1.93)] were significant predictors of progression, while borderline effects were observed for baseline glucose and diastolic blood pressure. Markers of adiposity were mostly stable or improved among non-progressors during follow-up, but deteriorated significantly among progressors, resulting in significant statistical interactions. CONCLUSIONS: High rates of deterioration of glucose status over time were found in our population, with nearly one-fifth of them acquiring a glucose tolerance worse status within a very short follow-up. Our study extends to this setting the well-known utility of phenotypes of MetS single or in combination, in predicting worsening in glucose tolerance status.
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Diabetes Mellitus/epidemiología , Femenino , Intolerancia a la Glucosa/epidemiología , Humanos , Síndrome Metabólico/epidemiología , Persona de Mediana Edad , Factores de Riesgo , Sudáfrica/epidemiologíaRESUMEN
The aim of this pilot study was to assess the 30-year risk for cardiovascular disease (CVD) in the South Africa population of mixed-ancestry in individuals with non-diabetic hyperglycaemia, and undiagnosed and self-reported diabetes. Participants were drawn from an urban community of the Bellville South suburb of Cape Town. In total, 583 subjects without a history of CVD were eligible for lifetime CVD risk estimation. Gender-specific prediction for CVD risk was calculated using the 30-year CVD interactive risk calculator. High CVD risk (> 20%) was evident in normoglycaemic and younger subjects (under 35 years). The significant predictors of CVD were sibling history of diabetes, and triglyceride, low-density lipoprotein cholesterol and glycated haemoglobin levels (p < 0.001). The high lifetime risk in normoglycaemic and younger subjects may be considered a warning that CVD might take on epidemic proportions in the near future in this country. We recommend the inclusion of education on CVD in school and university curricula.