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Biomedical subjects

S Uthayakumar

Publications and source records attributed to S Uthayakumar.

22 records · Page 2Linked to original sources

Lymphocyte subpopulations in bronchoalveolar lavage fluid in asbestos workers.

We examined peripheral blood and bronchoalveolar lavage (BAL) fluid lymphocyte subpopulations in 29 asbestos workers, 10 with and 19 without clinical or radiologic evidence of asbestosis. Peripheral blood lymphocyte subpopulations were also measured in 13 control subjects. The mean OKT4:OKT8 (T-helper/inducer:T-suppressor/cytotoxic lymphocyte) ratio in BAL fluid in the 29 asbestos workers was 0.96 (range, not detected to 3.33), significantly less than 1.76 (1.33 to 2.67) in peripheral blood (p less than 0.001). There were no significant differences in OKT4:OKT8 ratios in peripheral blood between the 10 patients with asbestosis, the 19 asbestos workers without asbestosis, and the 13 normal control subjects or in the OKT4:OKT8 ratios in BAL fluid between patients with asbestosis and asbestos workers without asbestosis. In the group as a whole, 83% of those who had suffered more than 5 yr of exposure to asbestos showed OKT4:OKT8 ratios less than 1.2, whereas in those who had suffered fewer than 5 yr of exposure, 80% showed ratios greater than 1.2 (p less than 0.02). No other relationships between OKT4:OKT8 ratios and clinical, radiographic, or physiologic variables were observed.

Adult↗

Bronchoalveolar lavage and clearance of 99m-Tc-DTPA in asbestos workers without evidence of asbestosis.

We performed BAL and measured the clearance of 99m-Tc-DTPA in 20 non-smoking subjects (mean age 50, range 36-68 years) occupationally exposed to asbestos (mean duration 14, range 3-30 years). All had normal lung function and none had clinical or radiological evidence of asbestosis. The mean BAL results were: total cells per ml 737 X 10(3) (360-1210), percentage macrophages 79 (49-96), percentage lymphocytes 13 (1-42), percentage neutrophils 8 (1-40), percentage eosinophils 0 (0-3), asbestos bodies per ml 83 (0-550). Eight subjects showed increased percentage of lymphocytes and four others showed increased percentages of neutrophils when compared with normal ranges in our laboratory. Higher percentages of neutrophils correlated with longer duration of exposure to asbestos (r = 0.54, P less than 0.025), and shorter time since last exposure to asbestos (r = -0.54, P less than 0.025). Four subjects showed faster clearance of 99m-Tc-DTPA than was observed in 31 normal non-smoking control subjects. There was a tendency for faster solute clearance to be associated with greater numbers of BAL macrophages (r = -0.39, P less than 0.10) but there were no significant relationships between solute clearance and other BAL variables. BAL profiles in asbestos workers may be abnormal in the absence of clinical or radiological evidence of asbestosis.

Adult↗

Bronchoalveolar lavage in the diagnosis of diffuse pulmonary shadowing.

Bronchoalveolar lavage (BAL) was performed during fibreoptic bronchoscopy in 79 patients with undiagnosed diffuse radiographic pulmonary shadowing and in 20 control subjects undergoing investigation for respiratory symptoms not associated with diffuse radiographic shadowing. The highest percentages of cells other than macrophages found in BAL fluid from the controls were 11% for lymphocytes and a total of 10% for neutrophils and eosinophils. 72 (91%) of the patients with diffuse shadowing had higher percentages of one or more of these inflammatory cell types than were found in any of the controls. Patients with increased lymphocytes differed in their eventual diagnosis from those without increase lymphocytes but with increases in other inflammatory cells (P less than 0.001). The use of BAL cell profiles as an aid to diagnosis in certain situations is illustrated by calculation of predictive values using Bayes' theorem. BAL has diagnostic value in the investigation of diffuse pulmonary shadowing if the cell profile is considered in conjunction with other information.

Adolescent↗

Is bacterial vaginosis associated with cervical intraepithelial neoplasia?

Previous research has produced conflicting results regarding the association of bacterial vaginosis (BV) and cervical intraepithelial neoplasia (CIN). These studies have been weakened in their conclusions mainly by failure to adequately control for the presence of sexually transmitted infections (STIs). One proposed mechanism suggesting that carcinogenic nitrosamines acting either independently or via human papilloma virus (HPV) has not been fully tested previously. We undertook a prospective, case-controlled, cross-sectional study where the presence of STIs, in particular human papillomavirus (HPV) which is known to be associated with the development of CIN, was controlled for. Women with BV were not found to have CIN more frequently than women with normal vaginal flora and the quantities of nitrosamines produced by women with BV did not differ significantly from women without BV. We thus found that BV is not associated with CIN.

Animals↗