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Biomedical subjects

S Potgieter

Publications and source records attributed to S Potgieter.

13 recordsLinked to original sources
PubMed2003

Event related potentials during attention tasks in VLBW children with and without attention deficit disorder.

OBJECTIVE: Children born prematurely have a higher incidence of attention deficit disorder with or without hyperactivity. We have used visual event related potentials to study possible brain dysfunctions that could explain this higher incidence. METHODS: Very low birth weight (VLBW) children with and without AD/HD and term born children with and without AD/HD, were matched for IQ, age and socio-economic status (n=41, mean age 104 months). A visual oddball paradigm, consisting of target and non-target stimuli, was used with analysis of response times, error scores, N200, P300 and a P500 component. RESULTS: AD/HD children responded slower (F (1,38)=11.20, p<0.002); more varied (F (1,38)=21.77, p<0.000) and made more commission and omission errors (Kruskal-Wallis p<0.000). Non-target N200 was increased in amplitude (F (1.39)=4.01, p=0.05) with a wide anterior topography in children with AD/HD. The late positivity (P500) was decreased over central leads in children with AD/HD during the non-target stimuli (F (3,75)=3.00, p<0.036). No differences could be found in latency, amplitude or topography between VLBW children with AD/HD and term born children with AD/HD. CONCLUSIONS: Prematurity does not induce specific attentional brain dysfunction or maturation delays in stimulus processing during cognitive tasks. Other factors should be investigated to explain the higher incidence of AD/HD in VLBW children.

Analysis of Variance↗
PubMed1999

Immunological manifestations of HIV-infected children.

This cross-sectional study of stable HIV-infected children was designed to document the immunological manifestations of paediatric HIV infection and to determine whether inexpensive markers of immunosuppression could be identified. Investigations included lymphocyte count and subset analysis, levels of total protein, albumin, immunoglobulins, beta-2 microglobulin and neopterin. The median age of the 74 children studied was 16.5 months and 76% and 39% had subnormal percentage CD4+ counts and absolute CD4+ counts, respectively. According to the Centers for Disease Control (CDC) guidelines, 85% were moderately or severely immunosuppressed. The majority had elevated neopterin, beta-2 microglobulin, IgG, IgM and IgA concentrations. The IgG concentration correlated positively with total globulin, IgG1 and IgG3 concentrations. On bivariate analysis, the absolute CD4+ count correlated positively with total lymphocyte count (r = 0.28 < 0.48 < 0.64) and negatively with total IgG concentration (r = -0.47 < -0.27 < -0.04), IgG1 concentration (r = -0.51 < -0.31 < -0.08), and neopterin concentration (r = -0.49 < -0.28 < -0.04). There was no correlation between CD4+ count, total globulin or beta-2 microglobulin concentration. On multiple linear regression analysis only the total lymphocyte count correlated with CD4+ count. Furthermore, on bivariate analysis total lymphocyte count correlated positively with absolute CD8+ count (r = 0.82 < 0.88 < 0.92). In conclusion, although there was a positive correlation between absolute CD4+ count and total lymphocyte count, the clinical significance is questionable as the total lymphocyte count correlated more strongly with the absolute CD8+ count.

Analysis of Variance↗
PubMed1999

Plasma-soluble CD30 in childhood tuberculosis: effects of disease severity, nutritional status, and vitamin A therapy.

Plasma-soluble CD30 (sCD30) is the result of proteolytic splicing from the membrane-bound form of CD30, a putative marker of type 2 cytokine-producing cells. We measured sCD30 levels in children with tuberculosis, a disease characterized by prominent type 1 lymphocyte cytokine responses. We postulated that disease severity and nutritional status would alter cytokine responses and therefore sCD30 levels. Samples from South African children enrolled prospectively at the time of diagnosis of tuberculosis were analyzed. (Patients were originally enrolled in a randomized, double-blind placebo-controlled study of the effects of oral vitamin A supplementation on prognosis of tuberculosis.) Plasma samples collected at the time of diagnosis and 6 and 12 weeks later (during antituberculosis therapy) were analyzed. sCD30 levels were measured by enzyme immunoassay. The 91 children included in the study demonstrated high levels of sCD30 at diagnosis (median, 98 U/liter; range, 11 to 1,569 U/liter). Although there was a trend toward higher sCD30 levels in more severe disease (e.g., culture-positive disease or miliary disease), this was not statistically significant. Significantly higher sCD30 levels were demonstrated in the presence of nutritional compromise: the sCD30 level was higher in patients with a weight below the third percentile for age, in those with clinical signs of kwashiorkor, and in those with a low hemoglobin content. There was minimal change in the sCD30 level after 12 weeks of therapy, even though patients improved clinically. However, changes in sCD30 after 12 weeks differed significantly when 46 patients (51%) who received vitamin A were compared with those who had received a placebo. Vitamin A-supplemented children demonstrated a mean (+/- standard error of the mean) decrease in sCD30 by a factor of 0.99 +/- 0.02 over 12 weeks, whereas a factor increase of 1.05 +/- 0.02 was demonstrated in the placebo group (P = 0.02). We conclude that children with tuberculosis had high sCD30 levels, which may reflect the presence of a type 2 cytokine response. Nutritional compromise was associated with higher sCD30 levels. Vitamin A therapy resulted in modulation of sCD30 levels over time.

Adolescent↗
PubMed1998

Epidermoid tumours associated with lumbar punctures performed in early neonatal life.

Three children (ages 5, 7, and 12 years) with epidermoid tumours in the spinal canal, all of whom had a lumbar puncture during the early neonatal period, are reported. A considerable delay occurred from the first symptoms until the diagnosis was made. MRI of the lumbar spine was the method of choice in the diagnostic work-up. All three cases were successfully surgically treated. The link between lumbar punctures and epidermoid tumours and the possible risk factors involved are explored. Because of the variable clinical presentation, the possibility of the existence of these tumours should be considered in the differential diagnosis.

Age Factors↗
PubMed1998

[Grievances in South African hospitals: from a nursing service management perspective].

The nursing service manager is accountable for adequate and efficient personnel management in the nursing service and the management of grievances is an important aspect of the personnel management function. The question arises, however, how and when grievances in nursing services arose and developed? The purpose of this article is to give a historical description of the development and management of grievances in nursing services for the time frame 1652-1990. An historical analysis was undertaken by means of news paper analysis, as well as other written resources. The results show that the development of grievances are related to the development of hospitals in South Africa and that grievances were poorly managed. The following conclusions are made: grievances in nursing are related to the establishment of hospitals; the first official grievance was lodged in 1824 by a surgeon; grievance are mainly related to the working conditions, remuneration and management; complaints with salaries and food were lodged by nurses as early as 1869; it appears as if nursing service managers are not adequately skilled in the management of grievances experienced by nursing staff--the same mistakes are made leading to strike action by nurses/midwives; unhappiness with the inappropriate manner in which grievances are managed lead to industrial action by nursing staff since 1889. Continuous empowerment of nursing services managers in the management of grievances is important and therefore the development of a model for grievance management in nursing services is also recommended.

Collective Bargaining↗
PubMed1998

Survival of children in Cape Town known to be vertically infected with HIV-1.

OBJECTIVE: To determine the survival patterns of children in Cape Town known to be vertically infected with HIV. DESIGN: Retrospective record review of children diagnosed with symptomatic HIV infection during the period 1 December 1990-31 May 1995. SETTING: Hospitals in the Cape Town metropolitan area. PATIENTS: 193 children were known to be vertically HIV-infected. HIV diagnosis was based on the following criteria: two positive HIV enzyme-linked immunosorbent assays (ELISAs) in children older than 15 months and a positive ELISA together with a positive polymerase chain reaction (PCR) in younger children. The mothers of the children were known to be HIV-positive. On the basis of the presenting clinical findings children were assigned to a disease severity category (A, B or C) according to the Centers for Disease Control and Prevention (CDC)'s 1994 revised classification system for HIV infection in children. OUTCOME MEASURES: Survival was analysed according to the Kaplan-Meier method. Survival time was defined as the length of time between clinical diagnosis of HIV and death or last contact with the health services. Mortality risk in relation to specific variables at diagnosis such as age and clinical manifestations was determined by calculation of odds ratios (ORs) with 95% confidence intervals (CIs). RESULTS: The median age at diagnosis was 5 months; 72% of children were aged less than 1 year at diagnosis. According to the CDC clinical classification, 47 (24%) fell into category A, 111 (58%) into category B and 35 (18%) into category C. Of the 193 patients 85 (44%) were alive at the time of review, 65 (34%) had died and 43 (22%) were lost to follow-up. Risk of death was significantly associated with age less than 6 months (OR 4.7, CI 2.1-10.3) and severe disease, i.e. CDC category C (OR 2.7; CI 1.1-6.9) at time of diagnosis. The median survival for all the children from time of diagnosis was 32 months. Infants diagnosed before 6 months of age had significantly shorter median survival (10 months) compared with 36 months for those diagnosed at 7-12 months of age. For the children over the age of 12 months the cumulative proportion surviving at 48 months was 78%. Children with severe disease (category C) had a median survival of 21 months, significantly lower than that in category B (32 months). For the children in category A the cumulative proportion surviving at 48 months was 66%. CONCLUSION: The median survival of children with HIV was 32 months from time of diagnosis, and survival was influenced by age and disease severity.

Acquired Immunodeficiency Syndrome↗
PubMed1997

Vitamin A status and therapy in childhood pulmonary tuberculosis.

Low plasma vitamin A levels (mean, 18.1 +/- 10.3 micrograms/dl, 62% below normal) were demonstrated in South African children with pulmonary tuberculosis. More extensive or severe disease (e.g., additional extrapulmonary tuberculosis) and low levels of retinol binding protein, prealbumin, and albumin were associated with low vitamin A levels. High-dose vitamin A therapy had no effect on disease outcome.

Child↗
PubMed1997

[A model for handling grievances in nursing services].

A model for management of grievances in a nursing service is described, in terms of the guidelines for model generation, based on a qualitative, exploratory, descriptive and theory generating research strategy and design. Potgieter's (1992) research served as the conceptual framework for the description of a model case. The statements derived from this description was used as basis for the description of the model. The central concepts were identified, defined and classified. The model was implemented in practice and was evaluated by means of a retrospective case study. Guidelines for the implementation of the model were consequently described and the model was positively evaluated by a panel of experts. The testing of hypothesis is recommended to validate the model.

Employee Grievances↗