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Biomedical subjects

R L Cowie

Publications and source records attributed to R L Cowie.

17 recordsLinked to original sources
PubMed1992

Seizures and neurocysticercosis in black men.

Men from a working population of black gold-miners were studied prospectively during an 8-month period to determine the incidence and aetiology of seizures in this population. Computed tomography (CT) of the brain was the primary investigation. From the total population of 97,000, 175 men with seizure disorders were admitted to the study and of these 165 underwent brain CT. In addition 138 subjects, who had brain CT for reasons other than seizures during the study period, served as controls. Sixty-three patients (38%) and 20 controls (14%) (P less than 0.0005) were considered to have definite or possible neurocysticercosis (NCC). Focal cerebral atrophy was the next most common abnormality and was found in 38 patients (23%) and 4 controls (3%) (P less than 0.0005). Otherwise unsuspected diagnoses, including tuberculoma, cerebral contusion and subdural haematoma, were made on CT in 10 cases. In 43% of patients with definite NCC, there was CT evidence of active disease and these subjects might be suitable candidates for treatment with antiparasitic chemotherapy. The high frequency of NCC in both the seizure patients and the control group indicates a need for more active public health measures. CT of the brain was extremely useful in determining seizure aetiology in this population.

Brain Diseases↗
PubMed1991

Silicosis, chronic airflow limitation, and chronic bronchitis in South African gold miners.

In a cross-sectional study of a working population of black South African gold miners, 1,197 men were studied with respiratory and occupational questionnaires, lung function tests, and chest radiographs. The study was designed to examine the effects of silicosis on respiratory symptoms and lung function. A total of 857 men with chronic, simple silicosis and 340 men without silicosis were included in the sample. Other determinants of lung disease including the duration and intensity of underground dust exposure and tobacco smoking were also examined. Three distinct pulmonary disorders could be discerned: silicosis-associated pulmonary dysfunction with dyspnea on effort; chronic airflow limitation, which was related to the duration of underground exposure; and a chronic bronchitic symptom complex, which reflected the intensity of dust exposure in the workplace. Chronic, uncomplicated silicosis was found to be associated with significant loss of lung function, and all of the measured indices, FVC, FEV1, FEV1/FVC%, maximal midexpiratory flow rate (MMEF), and lung diffusion for carbon monoxide measured by the single-breath method (DLCO) were reduced. When comparing men with Category 3/3 nodule profusion with men without silicosis, reductions of FVC of 351 ml, FEV1 of 447 ml, MMEF of 1.04 L/s, and DLCO of 4.7 ml/min/mm Hg (p = 0.0001) were detected after controlling for age, height, the direct effects of the underground environment, and tobacco smoking. Dyspnea on effort was more common in the men with silicosis (p less than 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1990

Captopril in hypertensive black men in southern Africa.

A group of 55 black men with mild or moderate hypertension who were being treated with methyldopa, prazosin, and a thiazide diuretic in combination with sotalol, were studied before and after changing their treatment to captopril and a thiazide diuretic. The level of blood pressure control was similar in the 11 men with mild hypertension but the 44 men with moderate hypertension were less well controlled with captopril and a thiazide diuretic. In the men with moderate hypertension the mean increase in the systolic blood pressure after the change in treatment was 4.7 mmHg (not significant) and in the diastolic pressure 6.2 mmHg (P less than 0.02). The mean blood pressure was higher during treatment with captopril in 37 men and lower in 18 men (P = 0.01). Thirty-seven men found both regimens acceptable and 33 of these men preferred the captopril regimen; however, 15 men said they did not like the captopril regimen while only 4 men did not like the methyldopa/prazosin regimen (P less than 0.01). Side-effects from the captopril regimen were reported by 18 of the men and from the methyldopa/prazosin regimen by 6 men (P less than 0.02). It was concluded that the captopril/thiazide regimen was less effective than the methyldopa/prazosin/sotalol/thiazide regimen for the control of moderate hypertension in this population of black men. Although the men who liked both regimens preferred the captopril regimen, that regimen was associated with significantly more side-effects and was disliked by more of the men than was the methyldopa/prazosin regimen.

Captopril↗
PubMed1990

Short-course chemotherapy for pulmonary tuberculosis with a rifampicin-isoniazid-pyrazinamide combination tablet.

The effectiveness of a tablet containing a combination of rifampicin, isoniazid and pyrazinamide (Rifater; Mer-National) in the treatment of pulmonary tuberculosis was examined by comparing it with a previously evaluated four-drug regimen. Of 150 black goldminers with a first case of pulmonary tuberculosis, 69 were randomly allocated to receive the combination tablet (RHZ), 5 tablets per day on weekdays for 100 treatment-days, and 81 the four-drug regimen (streptomycin, rifampicin, isoniazid and pyrazinamide) (RHZS). Non-compliance was detected in 42% of the RHZ group and in 16% of the RHZS group. Two patients in the RHZ group and 4 in the RHZS group had to have their treatment altered because routine investigations revealed drug-resistant mycobacteria. Treatment was unsuccessful in 10 patients in the RHZ group, with 4 men failing to complete the regimen and being lost to follow-up, 3 cases of failure of conversion of sputum on the regimen, and 3 relapses. The results for the RHZS group were similar, with 4 failures to complete the regimen, 2 treatment failures and 4 relapses. Evaluation of RHZ showed it to be comparable with a previously evaluated, successful short-course regimen (RHZS). The high incidence of non-compliance probably reflects reduced supervision of this wholly oral regimen.

Adult↗
PubMed1990

Features of systemic sclerosis (scleroderma) in South African goldminers.

Systemic sclerosis is more common among men exposed to silica-containing dust than in the general male population. The clinical features of systemic sclerosis in a group of 24 black goldminers are described. The better-known presenting features of systemic sclerosis, including Raynaud's phenomenon and dysphagia, were rare in this population. Initial presentation was usually with nonspecific features including swelling of the feet or hands, weakness, arthralgia or symptoms of respiratory or cardiac disease. Clinical evidence of pleural or pericardial involvement was more common than is usually described in non-occupational systemic sclerosis. Interstitial lung disease was frequently encountered and renal disease was rare.

Adult↗
PubMed1990

The mycobacteriology of pulmonary tuberculosis in South African gold miners.

Two bacteriological surveys of gold miners with pulmonary tuberculosis diagnosed for the first time, have shown a stable level of primary drug resistance which is substantially lower than that reported for the home areas of these men. Initial drug resistance was detected in 12.7% of the 205 cultures of Mycobacterium tuberculosis in 1983-1984 and in 10.7% of 253 cultures in 1988-1989. Resistance to isoniazid was detected in 5.4% and 5.5% of the strains tested, to streptomycin in 6.8% and 5.1% and to rifampicin in 0% and 0.8% respectively. In a separate study, the sputum bacteriology of 691 miners with relapsed pulmonary tuberculosis was examined. M. tuberculosis was cultured from the sputum of 547 of the men and environmental mycobacteria (EM) in the remainder. Drug resistant tuberculosis was found in 20.5% of the previously treated men: isoniazid resistance in 14.3%, streptomycin resistance in 11.2% and rifampicin resistance in 3.7%. All of the rifampicin resistant strains were also resistant to isoniazid and 85% were resistant to streptomycin as well. Only EM were cultured from 29 of the 234, 1983-1984 sputum cultures, from 23 of the 276, 1988-1989 cultures and from 144 of the 691 relapse cultures. Mycobacterium kansasii (67%) was the commonest EM cultured.

Antitubercular Agents↗
PubMed1989

The five ages of pulmonary tuberculosis and the South African goldminer.

Pulmonary tuberculosis was the inevitable and terminal illness for goldminers during the 25 years after the opening of the Witwatersrand goldmines in 1886. Pioneer research and enlightened legislation resulted in reduced dust levels and less aggressive silicosis and progressively reduced the risk and severity of disease. Later antituberculosis drugs improved the outcome for those miners who still developed the condition. New generation antituberculosis drugs and short-course chemotherapy made it possible to cure pulmonary tuberculosis, even in men with silicosis. Nevertheless the incidence of pulmonary tuberculosis in black goldminers remains high. In the future, attention should be paid to improvement of disease detection; the role of chemoprophylaxis in men with silicosis and in other high-risk groups; and to sociopolitical modification, notably of the migrant labour system.

Gold↗
PubMed1989

Pulmonary dysfunction in gold miners with reactive airways.

In a cross sectional study of a working population of black South African gold miners a sample of 1197 older miners was examined. Airway reactivity determined by a greater than 10% response of the forced expiratory volume in one second (FEV1) to inhaled salbutamol was detected in 139 (12%) of the men. No relation was found between the extent of exposure to the underground environment and the frequency of airway reactivity. There was evidence of increased chronic airflow limitation in the men with reactive airways. This increase persisted after controlling for age, tobacco smoking, and for the presence and degree of silicosis. On average, the presence of reactive airways was associated with reduced (after bronchodilator) forced vital capacity (FVC) of 118 ml, 95% confidence interval (CI) 16 to 220 ml, FEV1 of 168 ml (95% CI 74-262 ml), FEV1/FVC% of 3% (95% CI 2.3-3.7%), and maximal mid-expiratory flow of 300 ml/s (95% CI 86-514 ml/s). Although there was no evidence that airway reactivity was induced by this occupational exposure, those with reactive airways appeared to be more susceptible to the adverse effects of the underground environment on the bronchial tree.

Airway Resistance↗
PubMed1989

Pulmonary tuberculosis in South African gold miners.

In 1977, a comprehensive tuberculosis management program was introduced at a medical facility which then served approximately 65,000 black gold miners. The effectiveness of this program was evaluated from the relapse rate after treatment in 2,776 men. Post-treatment follow-up averaged 23.5 months. Limited information on potential determinants of relapse was available for all subjects and more detailed information for subsets. The drug regimen was the major determinant of relapse. Age was not a determinant of relapse nor was primary resistance of Mycobacterium tuberculosis to antituberculosis drugs, which was infrequent. The initial extent and severity of disease had a direct relation with the risk of relapse. The risk of relapse was greatest during the first 3 yr after treatment but persisted for the duration of the observation period. Neither continued exposure to mine dust nor the presence of pre-existing silicosis were shown to be determinants of relapse. A 4.5-month, four-drug weekday regimen was identified as being particularly effective in this working population and may be suitable for use in other working populations in the developing world.

Actuarial Analysis↗
PubMed1987

Silica-dust-exposed mine workers with scleroderma (systemic sclerosis).

The incidence of scleroderma (systemic sclerosis) was found to be increased in a population of black men who were gold miners. Ten men with scleroderma were detected during a five-year period. The annual incidence of the disease in this population in the group aged 33 to 57 years was estimated to be 81.8 per million. All of the men with scleroderma had disturbances of pulmonary function which were not present in a control group of silica-dust-exposed men without scleroderma. Not all of the subjects with scleroderma had silicosis, but all had been occupationally exposed to silica dust. There was a significant increase in the prevalence of tuberculosis in the past in the group with scleroderma, compared with a group of men with silicosis from the same population. The nature of the association of tuberculosis with scleroderma has not been defined.

Adult↗
PubMed1977

An inexpensive apparatus (airflometer) to assess lung function.

The Airflometer is presented as an inexpensive instrument suitable for lung function testing in general clinical practice. Utilizing the close correlation between the Airflometer (AFM) reading and the forced expiratory volume in 1 second (FEV1), we have produced a nomogram from which the AFM reading for normal males and females can be predicted.

Adolescent↗