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Biomedical subjects

G du Toit

Publications and source records attributed to G du Toit.

13 recordsLinked to original sources
PubMed2005

Diagnostic accuracy of chest radiography in detecting mediastinal lymphadenopathy in suspected pulmonary tuberculosis.

OBJECTIVE: To estimate the diagnostic accuracy of chest radiography in the detection of chest lymphadenopathy in children with clinically suspected pulmonary tuberculosis. METHODS DESIGN: Prospective cross sectional study. SETTING: A short stay ward in a children's hospital in South Africa. PATIENTS: Consecutive children under 14 years of age admitted with suspected pulmonary tuberculosis. DIAGNOSTIC TEST: Antero-posterior and/or lateral chest x rays interpreted independently and blind to the reference standard by three primary care clinicians and three paediatricians, all with a special interest in tuberculosis. Reference standard: Spiral chest computed tomography (CT) with contrast injection. RESULTS: One hundred children (median age 21.5 months) were enrolled. Lymphadenopathy was present in 46 of 100 reference CT scans and judged to be present in 47.1% of x ray assessments. Overall sensitivity was 67% and specificity 59%. Primary care clinicians were more sensitive (71.5% v 63.3%, p = 0.047) and less specific (49.8% v 68.9%, p<0.001) than paediatricians. Overall accuracy was higher for the paediatricians (diagnostic odds ratio 3.83 v 2.49, p = 0.008). The addition of a lateral to an antero-posterior view did not significantly increase accuracy (diagnostic odds ratio 3.09 v 3.73, p = 0.16). Chance adjusted inter-observer agreement (kappa) varied widely between viewer pairs, but was around 30%. CONCLUSIONS: Detection of mediastinal lymphadenopathy on chest x ray to diagnose pulmonary tuberculosis in children must be interpreted with caution. Diagnostic accuracy might be improved by refining radiological criteria for lymphadenopathy.

Child, Preschool↗
PubMed2003

Limited Pap screening associated with reduced risk of cervical cancer in South Africa.

BACKGROUND: We investigated the effect of Pap smear screening on the incidence of invasive cancer of the cervix in the Western Cape, South Africa where screening is limited. METHODS: Data were derived from a case-control study of the association of hormonal contraceptives and invasive cervical cancer. Incident cases (n = 524) of invasive cervical cancer who presented at two tertiary hospitals and controls (n = 1540) series matched for age, race, and place of residence were interviewed. Information on a wide range of variables was collected including whether the women had previously had a Pap smear taken and the number and timing of smears. Odds ratios (OR) and 95% CI were calculated using multiple logistic regression. RESULTS: The OR of cervical cancer was reduced among women who had ever had a smear (OR = 0.3, 95% CI: 0.3-0.4). The OR declined with increasing number of smears to 0.2 for >/=>3 smears (trend P = 0.0003). Among women who had a smear <5 years previously the OR was 0.3, but even if the smear was taken >/=15 years previously the women remained at reduced risk (OR = 0.5). CONCLUSION: The data suggest that even limited Pap smear screening reduces the risk of cervical cancer. Should a screening programme be successfully implemented, the incidence of cervical cancer might be reduced by as much as 70%.

Adult↗
PubMed2002

Prevalence of pre-cancerous lesions and cervical cancer in South Africa--a multicentre study.

OBJECTIVES: To describe the age-specific prevalence rates of cancer of the cervix in South African women presenting for screening. DESIGN: A multicentre prevalence survey in 10 geographically defined areas following a common core protocol. Services were located in existing service sites, with the exception of KwaZulu-Natal which used a mobile service. Women aged 20 years and above were eligible for inclusion. OUTCOME MEASURES: Age-specific cervical cytologically diagnosed abnormality rates according to the Bethesda classification. RESULTS: During the study 20,603 women participated. Eighty per cent of the sample had never had a Pap smear before and just over 91% had not had a Pap smear in the last 5 years. In this study population 468 women screened (2.42%) were found to have low-grade squamous intra-epithelial lesions (LSIL) and the average age of these women was 33.1 years; 366 (1.8%) had high-grade SIL (HSIL) and these women were statistically significantly older at 37.97 years of age; and 92 women (0.47%) were found to have cytologically diagnosed invasive cancer. These women were significantly older, with an average age of 51.3 years. A clear relationship was found between age and LSIL, with younger women having a high rate of LSIL which decreases with increasing age. A similar but inverse relationship between age and invasive cancer is described, with the rate being low in young women and increasing with increasing age. A clear relationship between HSIL and age is not described in these data. The adequacy rate (satisfactory and satisfactory but limited) of the slides was 95%, and just under 92% of the study sample received their results. Not all women were appropriately referred and it was not possible to assess if women referred for treatment received it. CONCLUSIONS: These data indicate that cancer of the cervix is a common disease and that, similar to other countries, it is a disease of older women. These data give some positive indicators for future screening--older women will present for screening and the majority of women received their results. However, improvements in health system functioning are needed. A uniform national cytology reporting system is required as well as clear guidelines for providers on what action to take based on cytology reports. Linkage between the site of screening and treatment centre is inadequate and requires urgent attention in order to decrease cervical cancer mortality.

Adult↗
PubMed1993

Maternal nicotine exposure during pregnancy and development of emphysema-like damage in the offspring.

The aim of this investigation was to determine whether nicotine exposure (1 mg/kg body mass/d) during pregnancy and lactation contributes to the rupturing of alveolar septa in the lungs of neonatal rats. These rats received nicotine only via the placenta and mother's milk. The results show that maternal nicotine exposure interferes with elastic tissue formation. It also interferes with alveoli formation and causes the development of emphysema-like lesions. It is therefore suggested that maternal nicotine intake from smoking during pregnancy and lactation may interfere with lung development and maturation to an extent that increases susceptibility to emphysema.

Animals↗
PubMed1989

The use of banked femoral head bone allograft in spinal surgery.

A safe, simple, and inexpensive method of harvesting femoral head allograft bone and storing it in a mechanical deep-freeze is discussed. This banked bone has been used in 39 patients for posterior spinal fusions. The allograft bone was used only where insufficient autograft bone could be harvested, where the autograft bone was regarded as inferior in quality or when harvesting autograft bone would have been hazardous to the patient. The allograft bone was found to be very reliable in helping to achieve a solid spinal fusion.

Adolescent↗