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S K Gupta

Publications and source records attributed to S K Gupta.

At least 901 records · Page 50Linked to original sources

Inhibition of aflatoxin formation by 2-mercaptoethanol.

2-Mercaptoethanol inhibits growth of Aspergillus parasiticus NRRL 3240 and aflatoxin formation by the fungus. When added to the resuspended medium, 2-mercaptoethanol inhibited [1-14C]acetate incorporation into both aflatoxins and neutral lipids, thereby showing that it acts at an early stage of aflatoxin biosynthesis. The inhibition is probably due to its chelating action on zinc, which is essential for aflatoxin production. It is proposed that any chelating agent that selectively binds to zinc will inhibit aflatoxin formation.

Acetates↗

Effect of zinc on adenine nucleotide pools in relation to aflatoxin biosynthesis in Aspergillus parasiticus.

The adenylic acid systems of Aspergillus parasiticus were studied in zinc-replete and zinc-deficient media. The adenosine 5'-triphosphate levels of the fungus were high during exponential phase and low during stationary phase in zinc-replete cultures. On the other hand, the levels of adenosine 5'-diphosphate and adenosine 5'-monophosphate were low during exponential phase of growth and high during stationary phase. The adenosine 5'-triphosphate levels during exponential phase may indicate higher primary metabolic activity of the fungus. On the other hand, high adenosine 5'-monophosphate levels during stationary phase may inhibit lipid formation and may enhance aflatoxin levels. The inorganic phosphorus content was low in a zinc-replete medium throughout the growth period, thereby favoring aflatoxin biosynthesis. The energy charge during the exponential phase was high but low during the stationary phase. In general the energy charge values were lower because of high adenosine 5'-monophosphate content.

Adenine Nucleotides↗

The effect of zinc and phytic acid on the incorporation of 1-14C-acetate into aflatoxin by resting mycelia of Aspergillus parasiticus.

The effect of zinc and phytic acid on [1-14C]-acetate incorporation into aflatoxins by resting mycelium was studied. When different levels of ZnSO4 were used to study its effect on the incorporation of [1-14C]-acetate into aflatoxins, it was found that the specific radioactivity incorporation into aflatoxins was maximum at the level of 10 mM-ZnSO4. At this concentration the change in the specific radioactivities of aflatoxins B1 + B2 and aflatoxins G1 + G2 were +74.61% and +29.66%, respectively. On the other hand, phytic acid had an inhibitory effect on the incorporation of [1-14C]-acetate. These observations have been correlated in order to find out why soyabean is unable to produce aflatoxins by Aspergillus parasiticus.

Acetates↗

Rhinosporidiosis.

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Adolescent↗

Evaluation of growth hormone release in children using arginine and L-dopa in combination.

L-Dopa in a dose ranging from 125-500 mg and arginine monochloride in a dose of 0.5 gm/kg were given simultaneously to 56 children with short stature (height less than third percentile). Sixteen of these children were subsequently diagnosed as having growth hormone deficiency. The diagnosis of hyposomatotropism was based on clinical findings and on responses to the combination test and to arginine and L-dopa administered as separate tests. All of the remaining 40 children had a normal GH response of greater than 6 ng/ml to the combination test. However, in this group, nine children were identified who responded to the combination test but who failed to respond to arginine and L-dopa in individual tests. The data suggest that a positive response to arginine and L-dopa in combination in children, who do not respond to the usual provocative tests when administered individually, may fail to identify children with partial GH deficiency who would benefit from treatment. The integrated stimulated GH response in the 31 children in whom a normal GH response to all three tests occurred suggests that the effects of L-dopa and arginine are additive.

Adolescent↗

Preparation and anticoagulant activity of trimethylsilyl heparin in Carbowax.

Trimethylsilyl heparin, when administered intraduodenally or intragastrically to rats, did not increase intestinal absorption and, consequently, the clotting times were not influenced. However, suspension of sodium heparin in Carbowax 200 prolonged the whole blood clotting time at a dose of 50 mg/kg when given intraduodenally or intragastrically to rats.

Animals↗