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Biomedical subjects

J Sherma

Publications and source records attributed to J Sherma.

14 recordsLinked to original sources

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

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

Pesticides.

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Chromatography, Gas

Pesticides.

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Pesticide Residues

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

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

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