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J van Zyl

Publications and source records attributed to J van Zyl.

14 recordsLinked to original sources
PubMed2004

Efficacy and safety of pantoprazole versus ranitidine in the treatment of patients with symptomatic gastroesophageal reflux disease.

BACKGROUND/AIM: Gastroesophageal reflux disease (GERD) is a prevalent disease associated with a high symptom burden and a reduced quality of life. This multicenter, randomized, double-blind study compared relief from key GERD symptoms (heartburn, acid eructation, and pain on swallowing) and from other gastrointestinal symptoms (epigastric pain, vomiting, nausea, flatulence, retching, and retrosternal feeling of tightness) and safety profiles of the proton pump inhibitor pantoprazole and the H2 antagonist ranitidine in patients suffering from symptomatic GERD. METHODS: The patients [338 intention-to-treat (ITT) population; 284 per-protocol (PP) population] received 20 mg pantoprazole (once daily in the morning) plus ranitidine placebo (once daily in the evening; ITT n = 167, PP n = 136) or pantoprazole placebo (once daily in the morning) plus 300 mg ranitidine (once daily in the evening; ITT n = 171, PP n = 148) for 28 days. The primary efficacy criterion (ITT and PP populations) was relief from key GERD symptoms (heartburn, acid eructation, and pain on swallowing) after 28 days of treatment. Secondary criteria (PP) included relief from key GERD symptoms on day 14, relief from all gastrointestinal symptoms on days 14 and 28, and relief from key GERD symptoms on days 14 and 28. Safety evaluations included adverse events and laboratory assessments. RESULTS: Significantly more pantoprazole-treated patients were free from key GERD symptoms at day 28 (68.3%, n = 114) as compared with ranitidine-treated patients (43.3%, n = 74; 95% confidence interval for odds ratio 1.84-4.51). Pantoprazole was also significantly more efficacious in controlling all gastrointestinal symptoms of GERD. By day 28, 51.5% (n = 70) of the pantoprazole-treated patients were completely symptom free versus 31.1% (n = 46) of the ranitidine-treated patients (95% confidence interval for odds ratio 1.45-3.83). Both treatments were well tolerated. CONCLUSION: Pantoprazole is significantly superior to ranitidine in the treatment of key and associated gastrointestinal symptoms of GERD and is well tolerated.

2-Pyridinylmethylsulfinylbenzimidazoles↗
PubMed2000

Risk of breast cancer in relation to the use of injectable progestogen contraceptives and combined estrogen/progestogen contraceptives.

Recent studies have suggested that progestogen-only contraceptives and combined estrogen/progestogen oral contraceptives (COCs) may increase the risk of breast cancer among women less than 35 years of age or among recent users. The authors conducted a case-control study, in which cases of breast cancer (n = 484) [corrected] and controls (n = 1,625) hospitalized for conditions unrelated to contraceptive use were interviewed from 1994 to 1997 in hospitals in greater Cape Town, South Africa. The women were aged 20-54 years, resided in a defined area around Cape Town, and were Black or of mixed racial descent. The relative risk for exposure to injectable progestogen contraceptives (IPCs), mostly depot medroxyprogesterone acetate, was 0.9 (95% confidence interval (CI) 0.7, 1.2). There were no consistent associations within categories of age or recency or duration of use. For exposure to COCs, the overall relative risk was 1.2 (95% CI 1.0, 1.5). Among women below age 35 years, the relative risk was 1.7 (95% CI 1.0, 3.0), and it was unrelated to the duration or recency of use. The findings suggest that IPCs do not increase the risk of breast cancer, and that COCs may increase the risk among women below age 35 years, although bias cannot be excluded.

Adult↗
PubMed2000

Breast cancer incidence and determinants of cancer stage in the Western Cape.

OBJECTIVE: To describe the overall and age-specific incidence rates for breast cancer and determinants of the stage of breast cancer at the time of diagnosis in the Western Cape, South Africa. METHODS: Data were derived from a case-control study of the association between injectable progestagen contraceptives and breast cancer conducted over a 4-year period from January 1994 to December 1997. In all, 485 cases were drawn from a study population consisting of coloured and black women under the age of 55 years, who presented with a first occurrence of invasive breast cancer at two tertiary hospitals in Cape Town. A questionnaire was administered and information on a large number of variables was recorded. RESULTS: The 249 cases who were interviewed during the first 2 years of the study constituted the numerator for estimates of incidence rates. The overall incidence rate was 23.1 per 100,000 women per year. The incidence rate for coloured women was 25.6 per 100,000, almost twice that for black women (14.7 per 100,000). The incidence rate in urban areas was 26.6 per 100,000, almost twice that in the rural areas (16.3 per 100,000). Stages 1 and 2 accounted for 57.8% of the cases. Early stage at diagnosis was significantly associated with a higher educational level, membership of a medical aid, residence in an urban area and a positive family history. CONCLUSION: The data suggest that there is scope for improvement in the detection of the disease through education and access to diagnostic measures, particularly in rural and disadvantaged populations.

Adult↗
PubMed1997

A case control study of breast cancer risk and exposure to injectable progestogen contraceptives. Methods and patterns of use among controls.

OBJECTIVE: To describe the patterns of use of injectable progestogen contraceptives (IPCs) among coloured and black women in the Western Cape. These data are part of an ongoing study in the Western Cape, the main aim of which is to explore the relationship between IPCs and breast cancer. DESIGN: A population-based case-control study of breast cancer risk in relation to the use of IPCs among coloured and black women. SETTING: The Western Cape, including the Cape metropole and surrounding rural areas. STUDY SUBJECTS: All coloured and black women with newly diagnosed breast cancer, resident in the study area and below age 55 years, who present at either of the two tertiary care hospitals in the Western Cape are recruited. Controls are a sample of hospitalised patients representative of the populations from which the patients are drawn. Cases are frequency-matched to controls according to cross-tabulation of age, ethnic group and residential area in a ratio of approximately 1:3. MEASUREMENTS: Questionnaires are administered by trained nurse interviewers, information is elicited on a wide range of variables, including sociodemographic variables, medical history, family history of breast disease, lifetime history of all methods of contraception and use of non-contraceptive female steroids, reproductive variables, cigarette smoking, alcohol consumption and other potentially confounding variables. RESULTS: Between January and December 1994, 122 incident cases and 389 controls were enrolled. Ever-use of IPCs among the controls was 72% (N = 280) and use for 5 years or more was 30% (N = 117). Use of IPCs in the distant past was common, with 61% (N = 232) of all controls having initiated use 10 or more years previously. Current use was also high (19%). Other contraceptive methods were used far less commonly. CONCLUSION: Coloured and black women in South Africa have been using and continue to use IPCs for more commonly and for longer periods than women anywhere else in the world. It is therefore especially important to evaluate the risk of breast cancer and other health effects of IPCs. The rates of use identified in this study ensure that there will be adequate statistical power to evaluate long-term use, use in the distant past and current use of IPCs.

Adult↗
PubMed1996

Bronchopulmonary dysplasia in infants with respiratory distress syndrome in a developing country: a prospective single centre-based study.

UNLABELLED: The aim of this prospective study was to determine the incidence of bronchopulmonary dysplasia (BPD) in and the outcome of neonates ventilated for respiratory distress syndrome (RDS). The study was conducted in a developing country prior to the use of surfactant replacement therapy and the results are compared to published reports from the developed world. BPD was defined as oxygen dependency beyond day 28 of life. The incidence of BPD over a 9-month-period was 8.2% of all neonates requiring ventilation (n = 169) and 41% (n = 38) of neonates ventilated for RDS (n = 92). Of those neonates who developed BPD, 26% were still being ventilated on day 28. Of the infants, 21 (55%) developed type 1 BPD and 17 (45%) type 2 BPD. There was no statistical difference in the severity of lung disease on any of the study days between type 1 and type 2 BPD although neonates with type 2 BPD required assisted ventilation and supplemental oxygen for a longer period: 30 versus 12 days and 95 versus 49 days, respectively. Of those neonates who developed BPD, 8 (21%) died prior to discharge from hospital and a further 5 infants (17%) died subsequent to discharge. Of the latter five, three died from treatable causes (gastroenteritis n = 2, pneumonia n = 1). Of the 25 (83%) children seen at follow up, 68% were developing normally, 20% were classified as having suspect development and 12% had developed cerebral palsy at corrected postnatal ages of 12-24 months. None of the results differed significantly from those of neonates being ventilated in the developed world, except for the causes of post-discharge deaths. CONCLUSION: Health services providing ventilation for neonates in the developing world will have to take the needs of children with BPD into account when planning a neonatal service which should include among others a widely available and easily accessible primary health care system.

Birth Weight↗
PubMed1994

Lipid peroxidation and platelet membrane fluidity--implications for Alzheimer's disease?

In humans, the fluidity of cell membranes generally decreases with age. Unexpectedly, several laboratories have found increased fluidity of platelet membranes (mainly endoplasmic reticulum) in patients with Alzheimer's disease (AD) compared with controls. In the present study, free radical induced lipid peroxidation was found to increase the fluidity of platelet membranes. Hydroxyl radicals were generated in the presence of Fe2+ and EDTA at low concentrations of ascorbate. It is hypothesised that platelet membranes are unable to restore their microviscosity by incorporating cholesterol. There may be a link between the result obtained in this study, the recently discovered decreased cholesterol content of affected AD neuronal membranes, and the increased frequency of epsilon 4 apolipoprotein E (a cholesterol carrier) found in AD patients.

Alzheimer Disease↗
PubMed1991

Improved method for the routine identification of toxigenic Escherichia coli by DNA amplification of a conserved region of the heat-labile toxin A subunit.

This report describes a DNA amplification procedure for routine identification of heat-labile-toxin-producing Escherichia coli. Two oligonucleotide primers were used in a polymerase chain reaction procedure to amplify a highly conserved region of the A subunit of the heat-labile enterotoxin gene. Amplifications were done directly on E. coli colonies from plates when Salmonella, Shigella, or parasite infections were excluded as agents of the severe diarrhea in the patients. The conditions for the polymerase chain reaction method were empirically determined, and the procedure is inexpensive, sensitive, and specific. Positive results can be obtained over a wide variation in bacterial numbers, with no inhibition of Thermus aquaticus DNA polymerase. Detection of the amplified product can be done by agarose gel electrophoresis, which is specific and sensitive enough for routine diagnosis of this pathogen in clinical isolates. If greater sensitivity and specificity are required, hybridization with 32P- or alkaline phosphatase-labeled oligonucleotide probes can be used. Our results suggest that heat-labile-toxin-producing E. coli is responsible for about 9% of nondiagnosed diarrhea cases in Tygerberg Hospital, Tygerberg, Republic of South Africa.

Alkaline Phosphatase↗
PubMed1972

[Acute erythremia].

Explore the source record for details and available documents.

Acid Phosphatase↗
PubMedDate not supplied

Effect of nicotinic acid conjugated to DNA-transfecting complexes targeted at the transferrin receptor of HeLa cells.

A conjugate consisting of streptavidin (biotinylated transferrin)-biotinylated polylysine for DNA delivery to cells was modified by partial nicotinylation of the polylysine component of the conjugate and used for transfection studies. A conjugate of biotin10-nicotinyl60-polylysine250 containing 60 weakly basic nicotinyl (pyridine-3-carboxyl) residues was prepared. The design of the modified polylysine was directed to the possible binding of H+ ions in the endosome-lysosomal vesicles (pH 5-6) by the nicotinyl groups, thus circumventing the use of chloroquine. The results obtained, however, while showing a 5- to 6-fold increase in luciferase transfection activity still necessitated an absolute requirement for chloroquine. A further polylysine conjugate containing a larger number of nicotinyl residues, biotin10-nicotinyl120-polylysine250, also was prepared and studied. This macromolecule stimulated luciferase activity to a small extent and was also dependent on chloroquine. Smaller biotinylated polylysine100 conjugates containing nicotinyl groups were also prepared. These were biotin10-nicotinyl30-polylysine100, and biotin10-nicotinyl60-polylysine100, respectively. Both substances, however, gave opaque, hazy aqueous solutions with precipitates on standing and could not be used for further experimental work. The results indicate that the introduction of weakly basic nicotinyl (pyridine-3-carboxyl) groups onto polylysine250 give conjugates that are unable to replace the lysosomotrophic agent chloroquine in the HeLa cell sysem studied. A 5- to 6-fold increase in luciferase activity, however, was found with biotin10-nicotinyl60-polylysine250.

Biotin↗