Browsing by Author "Van Rensburg, C. J."

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    Clinical characteristics of and prognosis in acute transmural anterior, transmural inferior and non-transmural myocardial infarction : a comparative retrospective study
    (Health & Medical Publishing Group, 1985) Van Rensburg, C. J.; Przybojewski, J. Z.; Soolman, J.
    This retrospective study was undertaken to determine whether there was any difference in the clinical characteristics of and prognosis in white patients admitted to the Intensive Coronary Care Unit (ICCU) at Tygerberg Hospital with acute non-transmural, transmural anterior and transmural inferior myocardial infarction (MI). The three groups were carefully matched, taking into consideration the possible influence of previous MI and congestive cardiac failure (CCF). There were 187 patients with nontransmural MI, and 176 with transmural anterior and 209 with transmural inferior MI. Patients with acute transmural anterior MI had the worst prognosis while at the ICCU, at 3-months' follow-up and at long-term follow-up (mean 22,2 months). This group had the greatest frequency of CCF, cardiogenic shock, acute pericarditis, ventricular premature beats, ventricular tachycardia, left anterior hemiblock and complete left bundle-branch block and the highest mortality. Acute transmural inferior MI was responsible for the highest frequency of ventricular fibrillation in the ICCU and had a worse prognosis than non-transmural MI. Acute non-transmural MI resulted in the highest incidence of early and late myocardial re-infarction; although death in the ICCU was least frequent, mortality among this group had increased dramatically by 3 months' follow-up. Hence, acute non-transmural MI is not benign and an unstable period exists for 3 months thereafter. Because of this, more aggressive diagnostic measures should be instituted during this period in order possibly to improve prognosis in this group. It would appear that this is the first such study undertaken in South Africa.
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    Identification of clinically-informative biomarkers within the spectrum of gastro-oesophageal reflux disease in the South African population
    (Stellenbosch : University of Stellenbosch, 2006-03) Van Rensburg, C. J.; Kotze, Maritha J.; Wright, C.; De Jong, G.; University of Stellenbosch. Faculty of Health Sciences. Dept. of Pathology. Anatomical Pathology.
    Patients with chronic gastro-oesophageal reflux disease are predisposed to Barrett’s metaplasia and oesophageal adenocarcinoma. The availability of molecular markers that can objectively identify patients with Barrett’s oesophagus at increased risk of carcinoma is highly desirable. A literature search was conducted to identify potentially useful biomarkers for genotype-phenotype correlation studies in South African patients with Barrett’s oesophagus. The COX-2, c-myb and c-myc genes selected for mRNA expression analysis were analysed in 26 patients with Barrett’s metaplasia (BM) without dysplasia; 14 with Barrett’s oesophagus and dysplasia (BD); 2 patients with Barrett’s adenocarcinoma (BAC); 19 with erosive oesophagitis (ERD); 25 with non-erosive oesophagitis (NERD) and 19 control individuals with a normal gastroscopy and no gastro-oesophageal reflux disease (GORD) symptoms. In the BD/BAC group, 69% (11/16) showed increased c-myb mRNA expression compared with 35% (9/26) in the BM group (p = 0.03). A statistically significant difference (p = 0.002) in c-myb expression was also observed between Barrett’s patients (20/42, 48%) and the control groups (9/63, 14%). In the BD patients, 21% (3/14) had increased c-myc mRNA expression compared with none in those with BM (p < 0.05) and BAC. No significant differences in mRNA expression levels were observed between ethnic groups for the genes analysed. In an attempt to determine whether the low expression level of c-myc in the study cohort may be related to possible gene-gene interaction, DNA samples of 199 individuals were subjected to genotyping of the functional GT-repeat polymorphism in the promoter region of the NRAMP1/SLC11A1 gene. Both these genes are involved in iron metabolism and c-myc is known to repress NRAMP1/SLC11A1. Genotype and allele frequencies were similar in all the groups studied with the 3/3 genotype being the most common. However, none of the three above-mentioned BD patients with increased c-myc mRNA expression had the 3/3 genotype. Therefore, although small in number, c-myc-NRAMP1/SLC11A1 interaction may be of adverse significance in patients with allele 2. TP53 mutation analysis was performed on 68 Barrett’s patients, and TP53 immuno-staining on oesophageal biopsy specimens of 55 subjects. Sporadic TP53 mutations were not identified in any of the patients with BM or dysplasia without BAC. Immuno-histochemistry staining of 2+ and 3+ intensity was similar in patients with metaplasia and dysplasia (58%). The low mutation frequency and relative non-specificity of TP53 immunostaining observed in Barrett’s patients seem to preclude its widespread use as a screening tool. TP53 mutation detection may however be useful for risk stratification once dysplasia has been diagnosed, as mutations G245R and D281Y were identified in two patients with BAC. Of the genes studied in the South African population, c-myb represents the most useful marker for early detection of an increased cancer risk in Barrett’s patients. In future, patients with Barrett’s oesophagus may benefit from genetic assessment to complement existing cancer surveillance and treatment strategies.
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    Syphilitic coronary ostial stenosis : case reports
    (Health & Medical Publishing Group, 1983) Przybojewski, J. Z.; Van Rensburg, C. J.
    Two young Coloured men with proven syphilitic coronary ostial stenosis had severe angina pectoris unresponsive to conventional medication. One underwent an aortic valve replacement for severe aortic insufficiency associated with subtotal ostial occlusion of the right coronary artery (RCA), which was corrected by an aortocoronary bypass graft; the left coronary artery (LCA) ostium was normal and patent. The other patient had total occlusion of the LCA ostium which resulted in an extensive transmural anteroseptal and anterolateral myocardial infarction; the RCA ostium was unaffected and the aortic valve appeared normal. He was considered unsuitable for cardiac surgery and continued to receive anti-anginal drug therapy with quite satisfactory improvement in symptoms. Non-atheromatous coronary artery disease must always be sought for and excluded when a non-White patient presents with symptoms of ischaemic heart disease. Although atheromatous coronary artery involvement is becoming increasingly prevalent among 'westernized' Black and Coloured subjects, it is still relatively unusual in comparison with the extremely high incidence in the White population.