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S Rajagopalan

Publications and source records attributed to S Rajagopalan.

118 records · Page 7Linked to original sources
PubMed1982

Heterogeneity of tetracycline resistance determinants in Streptococcus.

We found that naturally occurring tetracycline resistance in streptococci is encoded by more than one genetic determinant. Two of these distinct determinants were cloned, and the regions that are necessary and sufficient for expression of tetracycline resistance were defined by deletion analysis. These cloned determinants were further characterized by DNA-DNA hybridization experiments which also identified a third genetically unrelated tetracycline resistance determinant. Some of these genetic differences appear to represent mechanistic differences. The tetL determinant was associated with small nonconjugative plasmids and mediated resistance to tetracycline. The tetM determinant was most often "nonplasmid" associated and mediated resistance to minocycline as well as tetracycline. The tetN determinant was represented on a large conjugative plasmid and was genetically distinct from tetL and tetM, although phenotypically it resembled tetM.

Cloning, Molecular↗
PubMed1979

A unique subgenomic species of adenovirus 2 DNA generated under high multiplicities of infection.

We have identified a novel subgenomic viral DNA in KB cells infected with adenovirus 2 (Ad2) under high multiplicities of infection. KB cells were infected with Ad2 at multiplicities of infection greater than 100 PFU/cell. 32P-labeled viral DNA was selectively extracted by a modification of the method of Hirt (8) from the infected cells and analyzed by electrophoresis on agarose gels. In addition to full-length DNA (33 to 23 x 10(6) daltons), a unique subgenomic DNA species of about 12 to 13% (2.6 x 10(6) daltons) of full-length DNA in size was found in the infected cells. This subgenomic DNA was found to be double stranded and was not packaged inside the virus particles. This DNA could be isolated in large amounts (30 to 50% of total viral DNA) from infected cells. When cleaved with restriction endonuclease KpnI, the subgenomic DNA yielded two fragments, each corresponding to about 6% and 7% of the full-length genome in size.

Adenoviruses, Human↗
PubMed1966

Comparative value of sputum smear examination and culture examination in assessing the progress of tuberculous patients receiving chemotherapy.

Bacteriological response is generally considered the best criterion for assessing the efficacy of chemotherapy in patients with pulmonary tuberculosis. The bacteriological methods most commonly used are examination of sputum smears for tubercle bacilli, culture of bacilli from sputum specimens, and drug-sensitivity tests on positive cultures. Culture examination, though more sensitive than smear examination in detecting tubercle bacilli, is time-consuming and economically impracticable as a routine method in most developing countries. A study was therefore undertaken at the Tuberculosis Chemotherapy Centre, Madras, to determine the relative value of smear examination and culture examination in predicting the outcome of treatment and assessing the efficacy of chemotherapeutic regimens in 515 patients (all with bacteriologically confirmed disease and isoniazid-sensitive organisms on admission) receiving isoniazid, alone or with sodium PAS. The results showed that the value of smear examination of overnight sputum specimens at monthly intervals closely approached that of culture examination in assessing the progress of the patients, the percentages of correct predictions by smear and by culture being of the same order. Smear examination was slightly less effective than culture examination in detecting differences in the efficacies of regimens, but it has been estimated that this disadvantage can usually be compensated for by increasing the study population by about 20%.

Antitubercular Agents↗
PubMedDate not supplied

The spectrum of glomerular diseases in the kingdom of bahrain: an epidemiological study based on renal biopsy interpretation.

Glomerular diseases continue to be the leading cause of end-stage renal disease globally. Hence it is important to recognize the glomerular disease pattern in any given geographical area to understand the pathobiology in the region as well as the incidence and progression of the disorder. A total of 498 renal biopsies were performed on patients with proteinuria, hematuria, and mild to moderate renal impairment during a period of 13 years (between January 1990 and December 2002) at a tertiary care hospital. Primary glomerular disease accounted for two-thirds of the glomerular diseases, which was 44.8% of all renal biopsies. The most common histological lesion was minimal change disease (30%). Focal segmental glomerulosclerosis was the second most common lesion (23.8%) followed by membranoproliferative glomerulonephritis (14.3%). Secondary glomerular disease included 33.6% of glomerular diseases with 22.7% with lupus nephritis as the commonest lesion (38.9%) followed by diabetic nephropathy (31.9%) and hypertension (20.4%). Tubulointerstitial diseases accounted for 13.1% of all renal biopsies, whereas transplant diseases were noted in 12.2%. The miscellaneous group including inadequate biopsies, which constituted 7.2% of all the tissues. The results of this analysis were compared with surveys from other parts of the world.

Adolescent↗