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Biomedical subjects

C N Paramasivan

Publications and source records attributed to C N Paramasivan.

At least 73 records · Page 4Linked to original sources

Susceptibility of south Indian strains of Mycobacterium tuberculosis to tuberactinomycin.

A total of 114 strains of Mycobacterium tuberculosis isolated from sputum samples of 114 patients of pulmonary tuberculosis in south India, were coded and tested for their in vitro susceptibility to tuberactinomycin (Tum) incorporated in Lowenstein-Jensen (LJ) medium. Of these strains, 95 (83.3%) and 15 (13.2%) were susceptible to Tum at 25 and 50 mg/l respectively. Only 4 (3.5%) strains were inhibited at 100 mg/l or more. Of the 37 drug sensitive strains, 2 (5.4%) were not susceptible to Tum at 25 mg/l compared to 17 (22.1%) of 77 strains-resistant to one or more of antituberculosis drugs (P less than 0.02). The drug susceptibility pattern of the strains revealed that there was no significant association of resistance between Tum and streptomycin or rifampicin or ethambutol or ethionamide or isoniazid. However, 15 (53.6%) of 28 kanamycin (K) resistant strains were not susceptible to Tum at 25 mg/l. This cross resistance between Tum and K was further studied in 24 and 15 K sensitive and resistant strains respectively, by correlating their proportion resistance at 16 mg/l and it was found to have a significant positive correlation (r = 0.55; P less than 0.01).

Drug Resistance, Microbial↗

Human tuberculosis sera show prominent antibody responses to particulate fractions of Mycobacterium tuberculosis.

Sera from smear-positive pulmonary tuberculosis patients and normal control subjects in Madras were analyzed by Western blotting for their reactivity with soluble and particulate (membrane-rich and cell wall-rich) antigen fractions extracted by sonication from Mycobacterium tuberculosis H37Rv. Discrimination between patient and control sera was best with particulate antigen fractions: 60% of patient sera reacted with a 38-kD antigen band and 90% reacted with a 55-kD band. Reactions of control sera with the 38- and 55-kD bands were infrequent and faint. The results suggest that a serodiagnostic test might be based on quantitation of responses to these two antigens.

Adolescent↗

Association of pulmonary tuberculosis and HLA in south India.

In 204 patients with smear-positive pulmonary tuberculosis HLA-A10, B8 and DR2 were more frequently found than in 404 control subjects (p = 0.01); the greatest attributable risk (0.29) was associated with HLA-DR2. The radiographic extent of disease was also associated with HLA-DR2 (p = 0.0001). In 152 patients with smear-negative pulmonary tuberculosis, the frequencies of HLA-A10 and B8, but not DR2, were greater in the control subjects (p = 0.001 and 0.01 respectively). HLA-DR2 may be involved in the pathogenesis of advanced pulmonary tuberculosis. Study of endogamous, genetically disparate populations (caste) revealed other HLA associations (A3, B12 and DR4) unique to them, suggesting that genes linked with the HLA complex might also be significant in the pathogenesis of tuberculosis.

Adult↗

Five year results of a 3-month and two 5-month regimens for the treatment of sputum-positive pulmonary tuberculosis in south India.

A controlled study of three short-course regimens was undertaken in South Indian patients with newly diagnosed, sputum-positive pulmonary tuberculosis. The patients were allocated at random to one of three regimens: a) Rifampicin, streptomycin, isoniazid and pyrazinamide daily for 3 months (R3); b) the same regimen as above but followed by streptomycin, isoniazid and pyrazinamide twice-weekly for a further period of 2 months (R5); c) the same as R5 but without rifampicin (Z5). A bacteriological relapse requiring treatment occurred by 5 years in 16.8% of 113 R3, 5.2% of 97 R5, and 20.0% of 115 Z5 patients with organisms sensitive to streptomycin and isoniazid initially. The differences in the relapse rates between the R3 and R5 regimens and the R5 and Z5 regimens were statistically significant (p less than 0.01 for both). Considering patients with organisms initially resistant to streptomycin or isoniazid or both, 7 of 52 patients (4 R3, 2 R5, 1 Z5) had a bacteriological relapse requiring retreatment.

Adolescent↗

Species level identification of non-tuberculous mycobacteria from South Indian BCG trial area during 1981.

In 1981, non-tuberculous mycobacteria (NTM) were obtained from 8.6% of 16 907 sputum specimens in a trial in the Chingleput district of Madras state to test the efficacy of BCG vaccination in the prevention of tuberculosis, but from only 0.6% of 672 autoclaved specimens cultured as part of a quality control procedure. This finding suggested that the NTM were truly derived from the sputum of the BCG trial subjects. The mycobacterial species could be identified in 966 (96.6%) of the first 1000 isolates of NTM: 54.6% were potential pathogens and 73.0% were slow growing. The species isolated most frequently were M. avium/intracellulare (22.6% of all NTM), M. terrae (12.5%) and M. scrofulaceum (10.5%). Those species accounting for 8-5% of all NTM were M. fortuitum, M. chelonei, M. flavescens, M. gordonae and M. vaccae.

BCG Vaccine↗

Effect of storage of sputum specimens at room temperature on smear and culture results.

A study of 41 specimens of sputum stored for up to 28 days at room temperature in a tropical country showed that smear results were not affected by storage, the positivity being 83% before storage and 80-83% after. The culture positivity was 88% before storage, and 83%, 68%, 22%, 13% and 0% after 3, 7, 14, 21 and 28 days of storage respectively. The reduction in positivity on storage attains significance at 7 days (P = 0.05). Another study involved 163 specimens of sputum and storage for 3, 5 or 7 days. Each specimen was examined before storage and after 2 periods of storage, at random. The smear results were again not affected. There was, however, significant loss of viability, the proportion culture positive being reduced from 92% before storage to 83% at 3 days (P = 0.05), 71% at 5 days (P less than 0.01) and 63% at 7 days (P less than 0.001). The contamination rate was 5%, 7%, 12% and 18% respectively. It is concluded that sputum should not be stored at room temperature for longer than 3 days for culture but it can be stored for 4 weeks without any loss of smear-positivity.

Bacteriological Techniques↗

Mycetomas in Madras.

In 90 of 150 cases clinically diagnosed as mycetoma in the Department of Pathology, Madras Medical College, from January 1964 to June 1975, histopathological study revealed granules. Besides special staining procedures, cultural methods were undertaken in recent cases. The age and sex incidence, site of lesion and the species of fungi identified on the basis of histological morphology of the granules are analysed. The disease was predominatly seen in the age group 21-40. Men were more frequently affected than women and the commonest site of the lesion was foot. Actinomycotic mycetoma (68-9%) was more often found than the maduromycotic type. Madurella mycetomi (37-8%) and Actinomadura madurae (26-7%) were the commonest causal agents. Nocardia spp. were the next most common (21-1%) followed by A. pelletieri (15-5%), S. somaliensis (5-6%) and presumably Allescheria/Cephalosporium spp. from only 3 cases of white grain mycetoma.

Acremonium↗

Antimicrobial resistance and incidence of R factor among Salmonella isolated from patients with enteric fever and other clinical conditions in Madras, India (1975-1976)

The incidence of transmissible drug resistance among Salmonella isolated from patients with enteric fever and other clinical conditions is reported. All of the Salmonella isolated were studied for antimicrobial resistance. Of the 336 strains, five were multiply resistant to drugs including chloramphenicol, and four of these strains transmitted resistance to Escherichia coli F-Lac+. Multiply drug resistant E. coli were isolated from 12 patients receiving chloramphenicol, and in seven cases the E. coli transmitted drug resistance to sensitive Salmonella isolated from the same patients. The occurrence of multiple drug resistance among Salmonella was not found to be restricted to a single serogroup, and multiple drug resistance in Salmonella paratyphi A in India is reported for the first time. Although the incidence of Salmonella carring R factor is negligible, the unpredictability of its occurrence poses a potential threat in a country where typhoid is endemic.

Chloramphenicol↗