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Biomedical subjects

M Viljoen

Publications and source records attributed to M Viljoen.

At least 37 records · Page 2Linked to original sources
PubMed1992

Whole blood serotonin levels in chronic renal failure.

Whole blood serotonin levels were investigated in a control group (n = 35) and in a group of chronic renal failure patients (n = 127) on various treatment regimen i.e. conservative treatment (n = 39), maintenance haemodialysis (n = 35) and after renal transplantation (n = 53). The whole blood serotonin levels, as determined by high performance liquid chromatography, were significantly lower in the chronic renal failure patients than in the control group (p = 0.0001). Whole blood serotonin levels were significantly lower in the white subjects than in the black subjects of the study (p = 0.0001).

Adult↗
PubMed1992

Tripartite structure of the Saccharomyces cerevisiae arginase (CAR1) gene inducer-responsive upstream activation sequence.

Arginase (CAR1) gene expression in Saccharomyces cerevisiae is induced by arginine. The 5' regulatory region of CAR1 contains four separable regulatory elements--two inducer-independent upstream activation sequences (UASs) (UASC1 and UASC2), an inducer-dependent UAS (UASI), and an upstream repression sequence (URS1) which negatively regulates CAR1 and many other yeast genes. Here we demonstrate that three homologous DNA sequences originally reported to be present in the inducer-responsive UASI are in fact three exchangeable elements (UASI-A, UASI-B, and UASI-C). Although two of these elements, either the same or different ones, are required for transcriptional activation to occur, all three are required for maximal levels of induction. The elements operate in all orientations relative to one another and to the TATA sequence. All three UASI elements bind protein(s); protein binding does not require arginine or overproduction of any of the putative arginine pathway regulatory proteins. The UASI-protein complex was also observed even when extracts were derived from arg80/argRI or arg81/argRII deletion mutants. Similar sequences situated upstream of ARG5,6 and ARG3 and reported to negatively regulate their expression are able to functionally substitute for the CAR1 UASI elements and mediate reporter gene expression.

Arginase↗
PubMed1992

Melatonin in chronic renal failure.

The melatonin status of patients in end-stage chronic renal failure (CRF) was evaluated by the determination of daytime plasma melatonin levels and by the investigation of the circadian rhythmicity of melatonin secretion. A significant increase in plasma melatonin concentration was found in all CRF patient groups investigated, i.e. CRF patients on conservative treatment (CT; n = 48), CRF patients on maintenance haemodialysis treatment (HD; n = 39) and CRF patients on peritoneal dialysis (PD; n = 32). Successful transplantation led to a marked reduction in plasma melatonin levels. The circadian rhythm of melatonin secretion would appear to be suppressed in CRF as the nocturnal secretory surge was absent in all HD patients and in 80% of the posttransplantation patients studied.

Circadian Rhythm↗
PubMed1992

[The status of clinical evaluation at South African universities].

The fact that clinical evaluation is a difficult and complex task of nursing education has been emphasized in the nursing literature since the early seventies. It is, nevertheless, a most important component of the teaching-learning process of nursing students and it has definite advantages. It: contributes to the improvement of the standard of nursing care; helps to identify problem areas for research; and contributes to high level professional preparation. In the light of these factors the aims of the study were to: determine and describe the position of clinical evaluation as a component of the teaching of undergraduate students in departments of nursing at universities in Southern Africa; draw up a proto-theoretical model for clinical evaluation. The second aim will be fully discussed in a follow-up article. The empirical data showed that nursing educationists in Southern Africa are not entirely up to standard regarding the skills required for clinical evaluation.

Clinical Competence↗
PubMed1991

Physical properties of the red blood cells in chronic renal failure.

The biophysical properties of red blood cells in three groups of chronic renal failure (CRF) patients were compared to those of a non-renal control group. A limited number of biochemical and other parameters influencing the physical characteristics of red cells were also studied. Physical characteristics varied from normal to strikingly abnormal depending on the presence of factors other than CRF. Uraemia per se, in contrast to general belief, would appear not to be the major determinant of red cell survival in CRF.

Adult↗
PubMed1990

Unmet health care needs in the aged in two rural South African communities.

An evaluation of the unmet health care needs of all the aged people in two rural villages in the northern Transvaal was undertaken by assessing 7 indicators of health status to determine the prevalence of significant health problems and of receipt of health care for such problems. Oral health problems were found in 81% of the sample, visual problems in 62%, low peak expiratory flow in 48%, significant gastrointestinal symptoms in 38%, significant urinary symptoms in 32%, anaemia in 23%, and a lack of independence in 14%. There were 283 problems needing care, for which treatment had been received in the last year in only 30 instances (11%). The lack of care is attributed mainly to the inaccessibility of health services and the lack of health care resources in 'homeland' areas.

Black or African American↗
PubMed1987

[The heart].

Explore the source record for details and available documents.

Arrhythmias, Cardiac↗
PubMed1986

Plasma vitamin E levels in a chronically hemolyzing group of dialysis patients.

Plasma vitamin E levels and the ascorbate cyanide test were assessed in 15 chronic hemodialysis (HD) patients (group A) exposed to persistently elevated chloramine levels in the dialysis water. The vitamin E levels in these patients, who had evidence of oxidant induced hemolytic anemia, were compared to 15 chronic HD patients exposed to low chloramine levels (group B) and 17 controls (group C). Vitamin E levels were found to be significantly lower in group A than in either groups B or C (p less than 0.001). Within group A, levels were lower in those patients who had a positive ascorbate cyanide test (p less than 0.05). Upon removal of chloramines from the dialysis water, vitamin E levels in group A were no longer significantly different from those found in groups B or C.

Ascorbic Acid↗