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Biomedical subjects

J Sherma

Publications and source records attributed to J Sherma.

At least 37 records · Page 2Linked to original sources
PubMed1993

Fatty acid composition of Echinostoma trivolvis (Trematoda) rediae and adults and of the digestive gland-gonad complex of Helisoma trivolvis (Gastropoda) infected with the intramolluscan stages of this echinostome.

Gas-liquid chromatographic studies were done to determine the fatty acid composition of the digestive gland-gonad (DGG) complex of Helisoma trivolvis snails infected with the intramolluscan stages of Echinostoma trivolvis, of rediae freed from the DGG, of uninfected DGG, and of 41-day-old adult worms grown in golden hamsters. The DGG of infected snails showed significantly higher levels of stearic acid (18:0), hexatrienoic acid (16:3n-4), and docosahexanoic acid (22:6n-3) than that of uninfected snails. However, the DGG of uninfected snails showed significantly higher levels of 20:2 non-methylene-interrupted diene (NMID) and adrenic acid (22:4n-6) than that of infected snails. The profiles of other fatty acids were remarkably similar in both infected and uninfected snails. Adult worms showed significantly higher amounts of numerous saturated fatty acids and dienes as compared with the rediae. However, the rediae showed significantly higher amounts of certain monoenes and trienes as compared with the adults. Fatty acid differences between rediae and adults probably reflect differences in either the available lipid pools in the immediate host sites or the metabolic activity of each stage of this echinostome.

Animals↗
PubMed1991

Reversal of dietary-induced hyperlipidemia in Biomphalaria glabrata (Gastropoda).

1. To determine if dietary induced hyperlipidemia in snails could be reversed, thin-layer chromatography studies were done on lipids in the digestive gland-gonad (DGG) complex of Biomphalaria glabrata fed either hen's egg yolk for 2 weeks (Group A), yolk for 1 week followed by leaf lettuce for 1 week (Group B), or lettuce for 2 weeks (Group C). 2. The major lipid fractions in Group A were triacylglycerols, phosphatidylethanolamine, and phosphatidylcholine, along with lesser amounts of sterol esters, methyl esters, free fatty acids, free sterols and unidentified phospholipids. 3. Groups B and C had about one-half the amount of triacylglycerols than Group A and did not show sterol esters or methyl esters. 4. The triacylglycerol increase of the DGG resulting from the hen's egg diet could be reversed by returning the snails to the lettuce diet.

Animals↗
PubMed1990

Sterols in the plasma and digestive gland-gonad complex of Biomphalaria glabrata snails, fed lettuce versus hen's egg yolk, as determined by GLC.

1. Gas-liquid chromatography studies were done on sterols in plasma and the digestive gland-gonad (DGG) complex of Biomphalaria glabrata snails fed lettuce vs hen's egg yolk. 2. The major sterols present in the DGG of both populations were cholesterol, stigmasterol, beta-sitosterol, campesterol, and desmosterol. 3. The percentage composition of cholesterol in the DGG of yolk vs lettuce fed snails was 82 and 51, respectively. 4. The elution profiles of sterols in the plasma of yolk vs lettuce fed snails were similar; both contained desmosterol, campesterol, and stigmasterol, negligible amounts of cholesterol, and unidentified sterols. 5. The high lipid diet increased the level of cholesterol in the DGG but not in the plasma.

Animals↗
PubMed1989

Pesticides.

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Chromatography, Gas↗
PubMed1987

Pesticides.

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Pesticide Residues↗
PubMed1985

Pesticides.

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Carbamates↗
PubMed1978

Quantitative determination of carbaryl in apples, lettuce, and water by densitometry of thin layer chromatograms.

A method for the quantitative determination of carbaryl insecticide by in situ densitometry was developed. After separation on silica gel thin layer plates, carbaryl residues were detected by using p-nitrobenzenediazonium fluoborate reagent and quantitated by scanning the resultant blue spots with a fiber optics densitometer and comparing them with standards. The method was applied to water fortified with carbaryl at 8 ppb and apples and lettuce fortified at 0.10 ppm; all recoveries were greater than 89%. The 2 crop extracts were cleaned up by using the AOAC thin layer chromatographic method for visual estimation of carbaryl. Related carbamate insecticides were detected by using the same reagent, and the potential for quantitation was demonstrated.

Carbaryl↗
PubMed1975

Chromatographic analysis of fungicides.

The separation and analysis of a wide range of fungicides, by gas, liquid, column, paper, and thin-layer chromatography have been reviewed. Major attention has been given to methods for the identification and quantitation of individual and multiresidues of fungicides in environmental and agricultural samples.

Chromatography↗
PubMed1975

A multiclass, multiresidue analytical method for determining pesticide residues in air.

A multiresidue method for chlorinated, organophosphate and N-methyl carbamate insecticides has been developed for use in the National Air Monitoring Program. The method involves partitioning and extracting the pesticides from the ethylene glycol trapping solvent with methylene chloride followed by fractionation and cleanup by elution through a silica gel column. The chlorinated compounds are determined by electron capture GC, phosphate compounds by flame photometric GC, and carbamates by electron capture GC after derivatization with pentafluoropropionic anhydride. Recovery data and limits of detectability are presented for 11 chlorinated, 7 phosphate, and 7 carbamate pesticides at high and low levels. It is expected that the method will be applicable to many other compounds not successfully determined by the present analytical procedure, and that it may be adaptable for the analysis of pesticide residues in foods and other environmental samples.

Air↗