Search PubMed⌕ Search

Biomedical subjects

R Kumar

Publications and source records attributed to R Kumar.

At least 1,513 records · Page 84Linked to original sources
PubMed1977

Development of immune response during typhoid fever in man.

The development of both humoral and cell-mediated immune responses (CMIR) to antigens prepared from Salmonella typhi was investigated in patients suffering from typhoid fever. The antibodies were determined by the standard Widal test while the leucocyte migration test was used for CMIR. These immunological parameters were correlated with the duration of illness, the duration of chloramphenicol therapy and the severity of the illness. It was found that CMIR appeared after the first week of illness in uncomplicated cases of typhoid fever, where as it remained negative in the patients who had complications. The antibody titres were similar in the two groups. On further follow up of complicated cases, the clinical recovery coincided with the development of CMIR. It may be concluded that for recovery in typhoid fever CMIR is more important than antibodies.

Adult↗
PubMed1976

Side chain metabolism of 25-hydroxy-[26,27-14C] vitamin D3 and 1,25-dihydroxy-[26,27-14C] vitamin D3 in vivo.

Radioactive CO2 was detected in expired air after the administration of 25-hydroxy-[26,27-14C] vitamin d3 to vitamin D-deficient hypocalcemic rats; 14co2 was also detected after the administration of 1,25-dihydroxy-[26,27-14C] vitamin D3 to rats raised on the same diet. Nephretcomy totally abolished 14CO2 formation after administration of 25-hydroxy-[26,27-14C] vitamin D3 but not after the administration of 1,25-dihydroxy-[26,27-14C] vitamin D3. The production of 14CO2 commenced within 4 hours after injection of 1,25-dihydroxy-[26,27-14C] vitamin D3, suggesting a possible relevance of this reaction to the function of 1,25-dihydroxyvitamin D3. These results at least demonstrate a new metabolic pathway of vitamin D3 metabolism involving the oxidation of a portion of the side chain of 1,25-dihydroxyvitamin D3 to CO2.

Animals↗
PubMed1976

Metabolism of 1,25-dihydroxyvitamin D3: evidence for side-chain oxidation.

Approximately 7% of a 650-pmol dose of 25-hydroxyl[26,27-14C]vitamin D3 and 25% of a 325-pmol dose of 1,25-dihydroxyl[26,27-14C]vitamin D3 are metabolized to 14CO2 by vitamin D deficient rats. Nephrectomy prevents the metabolism of 25-hydroxy[26,27-14C]vitamin D3 to 14CO2 but not that of 1,25-dihydroxy[26,27-14C]vitamin D3. Less than 5% of the 14C from 24,25-dihydroxy[26,27-14C]vitamin D3 is metabolized to 14CO2. Feeding diets high in calcium and supplemented with vitamin D3 markedly diminishes the amount of 14CO2 formed from 25-hydroxy[26,27-14C]vitamin D3 but not that from 1,25-dihydroxyl[26,27-14C]vitamin D3. These results provide strong evidence that only 1-hydroxylated vitamin D compounds and especially 1,25-dihydroxyvitamin D3 undergo side-chain oxidation and cleavage to yield an unknown metabolite and CO2.

Animals↗