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Biomedical subjects

I Gupta

Publications and source records attributed to I Gupta.

At least 91 records · Page 5Linked to original sources

A model study of fecapentaenes: mutagens of bacterial origin with alkylating properties.

Fecapentaene-14 and -12 are directly acting mutagens that do not require metabolic activation. Their unusual structure suggests a possible mechanism of action. A carbocation that is formed by the addition of an electrophilic species (such as a proton) to the enol ether is most probably the reactive species. A series of model enol ethers with conjugated systems of various lengths was prepared, and a correlation between mutagenicity and increasing reactivity of derived carbocations was found. The glycerol moiety does not play a crucial role in the overall reactivity of the fecapentaenes.

Alkylating Agents↗

On distribution of different fecapentaenes, the fecal mutagens, in the human population.

It has been shown by an HPLC analysis using a quarternary solvent mixture in an isocratic mode that human excretors of these fecal mutagens excrete both fecapentaene -12 and -14 but the ratios vary greatly between individuals. Since these mutagens are produced by the bacterial flora of the colon, this may indicate differences in the flora between these individuals or differences in the availability of different precursor molecules in their colons. Any relationship of these findings to the etiology of colonic cancer is not clear.

Adult↗

Aneurysm of the coronary sinus.

Two patients, an adult and a baby, with an aneurysm of the coronary sinus are described. This unusual anomaly was detected in the baby during angiographic investigations for congenital heart disease. The aneurysm was an unexpected postmortem finding in the adult. Although the adult died suddenly, there was no evidence that this could be linked to the presence of the aneurysm.

Adult↗

Giant cell tumour of the first metacarpal bone.

A rare case of giant cell tumour of first metacarpal bone which was aggressive in its clinical behaviour but histologically benign, is reported in a thirty-one year old male. The tumour was excised en-bloc with disarticulation of the thumb and index finger with a gratifying result. The literature on giant-cell-tumour of the metacarpal bone is reviewed.

Adult↗

Hydrocolpos with peritonitis in the newborn.

Two cases of hydrocolpos are described presenting soon after birth. One infant who died on the first day had an intrauterine peritonitis caused by compression of the caecum on the pelvic brim. The other surviving infant developed a caecal perforation secondary to Hirschsprung's disease. Neither infant had rectal atresia, which is the commonest cause of intestinal obstruction in these infants. The association of hydrocolpos with polydactyly in one of these cases may represent an autosomal recessive trait.

Female↗

Tyrosyluria in marasmus.

1. Plasma tyrosine and urinary p-hydroxyphenyl lactic acid (PHPLA) and p-hydroxyphenyl acetic acid (PHPAA) were studied in thirty patients with marasmus and twenty normal controls in the same age group. 2. In the control group conventional tyrosyluria was not observed but 30% of the group excreted high levels of PHPAA. In the group with marasmus, plasma tyrosine and urinary PHPLA and PHPAA values were signigificantly higher than the control values. However only 13.3% of the patients were considered to have conventional tyrosyluria and 52.3% were found to excrete high levels of PHPAA. 3. Administration of ascorbic acid resulted in a reduction of PHPLA excretion while it had no effect on PHPAA excretion. 4. It was inferred that (a) tyrosyluria in marasmus is due to the reduced activity of the hepatic enzyme 4-hydroxyphenyl pyruvate: oxygen oxidoreductase (hydroxylating, decarboxylating) (PHPAA-oxidase; EC 1.13.11.27) due to the deficiency of ascorbic acid and (b) high excretion of PHPAA is related to age and nutrition of the child and is unaffected by the administration of ascorbic acid. 5. It was further inferred that urinary excretion of PHPLA is a reliable index of tyrosyluria.

4-Hydroxyphenylpyruvate Dioxygenase↗