A. Mbewu - Academia.edu (original) (raw)

Papers by A. Mbewu

Research paper thumbnail of Coronary artery disease and risk factors in Black South Africans--a comparative study

Ethnicity & disease, 2004

The purpose of this study was to identify and compare coronary risk factors in different South Af... more The purpose of this study was to identify and compare coronary risk factors in different South African ethnic groups with angiographically documented significant coronary artery disease (CAD). An observational retrospective analysis. Hospital records of 500 consecutive patients with no previous coronary interventions who underwent coronary angiography at Chris Hani Baragwanath Hospital, Soweto over a 2-year period were reviewed. Patients with significant CAD were selected for this study. Data analyzed included demographics, presenting diagnoses, coronary risk factors, number of coronary arteries significantly affected and extent of CAD, left ventricular ejection fraction (LVEF), and the main treatment modality for CAD. Of the 206 patients with significant CAD, 85 were Africans and 121 were non-Africans. There were significantly more females in the African group (31% vs 12%, P=.0023) and hypertension was more prevalent in the same group (78% vs 55%, P=.0006). Serum total (TC) and low...

Research paper thumbnail of Myocardial infarction in a young woman during pregnancy

Journal of Obstetrics and Gynaecology, 1995

Research paper thumbnail of Antiretroviral therapy is only part of it

Bulletin of the World Health Organization, 2001

Research paper thumbnail of Celecoxib--is it worth celebrating?

South African medical journal = Suid-Afrikaanse tydskrif vir geneeskunde, 2000

Research paper thumbnail of Betabloqueantes para la hipertensión

Research paper thumbnail of Fluoxetine and ventricular torsade — is there a link?

International Journal of Cardiology, 1995

Research paper thumbnail of Serum lipoprotein (A) impairs the outcome of streptokinase therapy for myocardial infarction (MI)

Research paper thumbnail of Serum lipoprctein(a) following myocardial infarction

Research paper thumbnail of The immediate effect of streptokinase on serum lipoprotein(a) concentration and the effect of myocardial infarction on serum lipoprotein(a), apolipoproteins A1 and B, lipids and C-reactive protein

Atherosclerosis, 1993

(Lp(a)) has close structural homology with plasminogen and, at least in vitro, may interfere with... more (Lp(a)) has close structural homology with plasminogen and, at least in vitro, may interfere with tibrinolysis. Any changes in the serum Lp(a) concentration during and following myocardial infarction (MI) and whether the serum Lp(a) level is affected by streptokinase (SK) are therefore of interest. Serum Lp(a) levels immediately before and 3 h after completion of an intravenous infusion of SK in.39 patients with acute MI were not significantly different (median 31.3 mg/dl before and 35.9 mg/dl after). Furthermore, SK added during the serum Lp(a) assay did not affect the result, except at very high concentrations of SK (1000 units/ml). Serum Lp(a) and fasting lipids were measured daily for 3 days following definite MI in 13 patients and then after 14 and 42 days. There was no significant change in serum Lp(a) following MI. In marked contrast, C-reactive protein levels in these patients increased steeply immediately following MI. ,Thus, there was no early 'acute-phase response' in serum Lp(a) levels after MI. However, greater variation in its concentration was observed at day 14 than at other times. Serum cholesterol, apolipoprotein B and apolipoprotein Al concentrations decreased significantly following MI, whereas a significant transient increase in serum triglycerides occurred. Forty-two days after MI all lipid and lipoprotein values had regained their day 1 levels, except for apo Al, which remained depressed.

Research paper thumbnail of Global mandate in CVD prevention: From molecules to markets

Research paper thumbnail of Introductory Remarks: African Perspective on Natural Products and Molecular Medicine

Annals of the New York Academy of Sciences, 2005

Research paper thumbnail of A comparative study of six commercial lipoprotein(a) assays in seventeen laboratories within the British Isles

Annals of clinical biochemistry, 1996

Seventeen laboratories in the British Isles participated in a study to compare six different comm... more Seventeen laboratories in the British Isles participated in a study to compare six different commercially available immunoassays for serum lipoprotein(a) (Lp(a)) and to establish reasons for the variations in the measurement of serum Lp(a) concentrations. Pooled serum was distributed neat and after dilution at a central laboratory. In addition, the central laboratory sent unpooled serum sampled monthly from six healthy volunteers to each of the participating laboratories for 12 months. The assays all gave linear dilution curves which were parallel, although the reported values varied twofold. There were major differences in the values assigned to different manufacturers' calibrants which was not explained by whether the units employed were whole Lp(a), the protein moiety of Lp(a) or simply apolipoprotein(a). The coefficient of variation for the reported value of Lp(a) over 12 months was 33%. The component variation was 10% after adjustment for inter-laboratory and intra-laborato...

Research paper thumbnail of Plasma homocysteine and arterial thromboembolic disease

South African medical journal = Suid-Afrikaanse tydskrif vir geneeskunde, 2003

Research paper thumbnail of Celecoxib--the debate rages on

South African medical journal = Suid-Afrikaanse tydskrif vir geneeskunde, 2001

Research paper thumbnail of Aorto-iliac occlusive disease in the various population groups of South Africa

South African medical journal = Suid-Afrikaanse tydskrif vir geneeskunde, 2000

Research paper thumbnail of AIDS management options for SA

South African medical journal = Suid-Afrikaanse tydskrif vir geneeskunde, 2000

Research paper thumbnail of A prospective study of serum lipoproteins after coronary artery bypass surgery

QJM : monthly journal of the Association of Physicians, 1994

We examined the acute and long-term effects of coronary artery bypass (CABG) surgery on serum lip... more We examined the acute and long-term effects of coronary artery bypass (CABG) surgery on serum lipid, lipoprotein and apolipoprotein levels. One series of 34 patients having CABG surgery was studied pre-operatively and for six weeks afterwards, and another 22 patients were investigated before and two years after CABG surgery. None of the patients studied received any lipid-lowering drug therapy or specific dietary advice. In both groups, pre-operative serum lipoprotein (a) (Lp(a)) and serum triglyceride concentrations were raised and serum high-density lipoprotein (HDL) cholesterol and apolipoprotein AI (apo AI) were low compared to healthy people. Acutely, there were profound decreases of 40-60% in the serum levels of cholesterol (p < 0.001), low-density lipoprotein cholesterol (p < 0.05), triglycerides (p < 0.01), Lp(a) (p < 0.05) and apolipoprotein B (apo B) (p < 0.05). There was a small decrease in serum apo A1 (p < 0.05), and serum HDL cholesterol showed no cha...

Research paper thumbnail of Underweight, overweight and obesity among South African adolescents: results of the 2002 National Youth Risk Behaviour Survey

Public Health Nutrition, 2009

Objective: The present paper reports the prevalence of underweight, overweight and obesity by gen... more Objective: The present paper reports the prevalence of underweight, overweight and obesity by gender, ethnicity and grade, among participants in a 2002 national survey among South African school-going youth that included height and weight measurements. Design: A stratified two-stage sample was used. Nationally representative rates of underweight, overweight and obesity were calculated using weighted survey data and compared using x 2 analysis. Setting: In all, 9224 grade 8 to grade 11 students, present at school in selected classes within selected South African government-funded schools in all nine provinces, participated in this study. Most of the students were between 13 and 19 years of age. Results: Higher rates of underweight were observed for males than females as well as for black and 'coloured' than white students. Within each gender group, black and 'coloured' students had significantly higher rates of underweight than their white counterparts. Higher percentages of females than males were overweight and obese, overall and among black students. Furthermore, white male students had significantly higher rates of overweight than their black and 'coloured' counterparts. Among females, black and white students had significantly higher rates than 'coloured' students. Students in higher grades showed significantly lower rates of underweight and higher rates of overweight. Discussion: These data confirm that South Africa, a developing nation in socioeconomic transition, is experiencing both undernutrition and overnutrition. However, these problems are disproportionately distributed by gender, socioeconomics and ethnicity. Continued surveillance of nutritional status may be one important component of a national strategy to prevent and control malnutrition.

Research paper thumbnail of Commentary: Sexually transmitted infection in South Africa: 50 years after Sidney Kark

International Journal of Epidemiology, 2003

... The mass movements of the diamond rush and gold rush were the greatest dislocations hitherto ... more ... The mass movements of the diamond rush and gold rush were the greatest dislocations hitherto experienced in South Africa—presaging the forced removals of the apartheid years; which may themselves have played a part in the rapid spread of that other modern day STI: HIV. ...

Research paper thumbnail of Serum Lp(a) lipoprotein concentration and outcome of thrombolytic treatment for myocardial infarction

Heart, 1994

Background-Lp(a) lipoprotein has structural homology with plasminogen and has been shown to inhib... more Background-Lp(a) lipoprotein has structural homology with plasminogen and has been shown to inhibit plasminogen activation in vitro.

Research paper thumbnail of Coronary artery disease and risk factors in Black South Africans--a comparative study

Ethnicity & disease, 2004

The purpose of this study was to identify and compare coronary risk factors in different South Af... more The purpose of this study was to identify and compare coronary risk factors in different South African ethnic groups with angiographically documented significant coronary artery disease (CAD). An observational retrospective analysis. Hospital records of 500 consecutive patients with no previous coronary interventions who underwent coronary angiography at Chris Hani Baragwanath Hospital, Soweto over a 2-year period were reviewed. Patients with significant CAD were selected for this study. Data analyzed included demographics, presenting diagnoses, coronary risk factors, number of coronary arteries significantly affected and extent of CAD, left ventricular ejection fraction (LVEF), and the main treatment modality for CAD. Of the 206 patients with significant CAD, 85 were Africans and 121 were non-Africans. There were significantly more females in the African group (31% vs 12%, P=.0023) and hypertension was more prevalent in the same group (78% vs 55%, P=.0006). Serum total (TC) and low...

Research paper thumbnail of Myocardial infarction in a young woman during pregnancy

Journal of Obstetrics and Gynaecology, 1995

Research paper thumbnail of Antiretroviral therapy is only part of it

Bulletin of the World Health Organization, 2001

Research paper thumbnail of Celecoxib--is it worth celebrating?

South African medical journal = Suid-Afrikaanse tydskrif vir geneeskunde, 2000

Research paper thumbnail of Betabloqueantes para la hipertensión

Research paper thumbnail of Fluoxetine and ventricular torsade — is there a link?

International Journal of Cardiology, 1995

Research paper thumbnail of Serum lipoprotein (A) impairs the outcome of streptokinase therapy for myocardial infarction (MI)

Research paper thumbnail of Serum lipoprctein(a) following myocardial infarction

Research paper thumbnail of The immediate effect of streptokinase on serum lipoprotein(a) concentration and the effect of myocardial infarction on serum lipoprotein(a), apolipoproteins A1 and B, lipids and C-reactive protein

Atherosclerosis, 1993

(Lp(a)) has close structural homology with plasminogen and, at least in vitro, may interfere with... more (Lp(a)) has close structural homology with plasminogen and, at least in vitro, may interfere with tibrinolysis. Any changes in the serum Lp(a) concentration during and following myocardial infarction (MI) and whether the serum Lp(a) level is affected by streptokinase (SK) are therefore of interest. Serum Lp(a) levels immediately before and 3 h after completion of an intravenous infusion of SK in.39 patients with acute MI were not significantly different (median 31.3 mg/dl before and 35.9 mg/dl after). Furthermore, SK added during the serum Lp(a) assay did not affect the result, except at very high concentrations of SK (1000 units/ml). Serum Lp(a) and fasting lipids were measured daily for 3 days following definite MI in 13 patients and then after 14 and 42 days. There was no significant change in serum Lp(a) following MI. In marked contrast, C-reactive protein levels in these patients increased steeply immediately following MI. ,Thus, there was no early 'acute-phase response' in serum Lp(a) levels after MI. However, greater variation in its concentration was observed at day 14 than at other times. Serum cholesterol, apolipoprotein B and apolipoprotein Al concentrations decreased significantly following MI, whereas a significant transient increase in serum triglycerides occurred. Forty-two days after MI all lipid and lipoprotein values had regained their day 1 levels, except for apo Al, which remained depressed.

Research paper thumbnail of Global mandate in CVD prevention: From molecules to markets

Research paper thumbnail of Introductory Remarks: African Perspective on Natural Products and Molecular Medicine

Annals of the New York Academy of Sciences, 2005

Research paper thumbnail of A comparative study of six commercial lipoprotein(a) assays in seventeen laboratories within the British Isles

Annals of clinical biochemistry, 1996

Seventeen laboratories in the British Isles participated in a study to compare six different comm... more Seventeen laboratories in the British Isles participated in a study to compare six different commercially available immunoassays for serum lipoprotein(a) (Lp(a)) and to establish reasons for the variations in the measurement of serum Lp(a) concentrations. Pooled serum was distributed neat and after dilution at a central laboratory. In addition, the central laboratory sent unpooled serum sampled monthly from six healthy volunteers to each of the participating laboratories for 12 months. The assays all gave linear dilution curves which were parallel, although the reported values varied twofold. There were major differences in the values assigned to different manufacturers' calibrants which was not explained by whether the units employed were whole Lp(a), the protein moiety of Lp(a) or simply apolipoprotein(a). The coefficient of variation for the reported value of Lp(a) over 12 months was 33%. The component variation was 10% after adjustment for inter-laboratory and intra-laborato...

Research paper thumbnail of Plasma homocysteine and arterial thromboembolic disease

South African medical journal = Suid-Afrikaanse tydskrif vir geneeskunde, 2003

Research paper thumbnail of Celecoxib--the debate rages on

South African medical journal = Suid-Afrikaanse tydskrif vir geneeskunde, 2001

Research paper thumbnail of Aorto-iliac occlusive disease in the various population groups of South Africa

South African medical journal = Suid-Afrikaanse tydskrif vir geneeskunde, 2000

Research paper thumbnail of AIDS management options for SA

South African medical journal = Suid-Afrikaanse tydskrif vir geneeskunde, 2000

Research paper thumbnail of A prospective study of serum lipoproteins after coronary artery bypass surgery

QJM : monthly journal of the Association of Physicians, 1994

We examined the acute and long-term effects of coronary artery bypass (CABG) surgery on serum lip... more We examined the acute and long-term effects of coronary artery bypass (CABG) surgery on serum lipid, lipoprotein and apolipoprotein levels. One series of 34 patients having CABG surgery was studied pre-operatively and for six weeks afterwards, and another 22 patients were investigated before and two years after CABG surgery. None of the patients studied received any lipid-lowering drug therapy or specific dietary advice. In both groups, pre-operative serum lipoprotein (a) (Lp(a)) and serum triglyceride concentrations were raised and serum high-density lipoprotein (HDL) cholesterol and apolipoprotein AI (apo AI) were low compared to healthy people. Acutely, there were profound decreases of 40-60% in the serum levels of cholesterol (p < 0.001), low-density lipoprotein cholesterol (p < 0.05), triglycerides (p < 0.01), Lp(a) (p < 0.05) and apolipoprotein B (apo B) (p < 0.05). There was a small decrease in serum apo A1 (p < 0.05), and serum HDL cholesterol showed no cha...

Research paper thumbnail of Underweight, overweight and obesity among South African adolescents: results of the 2002 National Youth Risk Behaviour Survey

Public Health Nutrition, 2009

Objective: The present paper reports the prevalence of underweight, overweight and obesity by gen... more Objective: The present paper reports the prevalence of underweight, overweight and obesity by gender, ethnicity and grade, among participants in a 2002 national survey among South African school-going youth that included height and weight measurements. Design: A stratified two-stage sample was used. Nationally representative rates of underweight, overweight and obesity were calculated using weighted survey data and compared using x 2 analysis. Setting: In all, 9224 grade 8 to grade 11 students, present at school in selected classes within selected South African government-funded schools in all nine provinces, participated in this study. Most of the students were between 13 and 19 years of age. Results: Higher rates of underweight were observed for males than females as well as for black and 'coloured' than white students. Within each gender group, black and 'coloured' students had significantly higher rates of underweight than their white counterparts. Higher percentages of females than males were overweight and obese, overall and among black students. Furthermore, white male students had significantly higher rates of overweight than their black and 'coloured' counterparts. Among females, black and white students had significantly higher rates than 'coloured' students. Students in higher grades showed significantly lower rates of underweight and higher rates of overweight. Discussion: These data confirm that South Africa, a developing nation in socioeconomic transition, is experiencing both undernutrition and overnutrition. However, these problems are disproportionately distributed by gender, socioeconomics and ethnicity. Continued surveillance of nutritional status may be one important component of a national strategy to prevent and control malnutrition.

Research paper thumbnail of Commentary: Sexually transmitted infection in South Africa: 50 years after Sidney Kark

International Journal of Epidemiology, 2003

... The mass movements of the diamond rush and gold rush were the greatest dislocations hitherto ... more ... The mass movements of the diamond rush and gold rush were the greatest dislocations hitherto experienced in South Africa—presaging the forced removals of the apartheid years; which may themselves have played a part in the rapid spread of that other modern day STI: HIV. ...

Research paper thumbnail of Serum Lp(a) lipoprotein concentration and outcome of thrombolytic treatment for myocardial infarction

Heart, 1994

Background-Lp(a) lipoprotein has structural homology with plasminogen and has been shown to inhib... more Background-Lp(a) lipoprotein has structural homology with plasminogen and has been shown to inhibit plasminogen activation in vitro.