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Biomedical subjects

D J Lisk

Publications and source records attributed to D J Lisk.

At least 109 records · Page 6Linked to original sources

Element and polychlorinated biphenyl deposition and effects in sheep fed cabbage grown on municipal sewage sludge.

Sheep were fed a diet containing 30 per cent (dry weight) cabbage which had been grown on municipal sewage sludge from Syracuse, NY for 77 days. Slight increases were found in the concnetration of nickel in kidney, copper in liver and cadmium in certain animal organs as compared to those in sheep fed a control ration containing cabbage grown on soil. Polychlorinated biphenyls were also found at higher levels in the sludge-grown cabbage and in the livers of the respectively fed sheep as compared to controls. An increase in liver weight, proliferation of hepatic smooth endoplasmic reticulum and various degenerative changes were noted in the livers of the sheep fed the sludge-grown cabbage ration as compared to the controls.

Animal Feed↗

Toxicologic studies with sheep fed colored magazines and newsprint.

Paper containing colored inks from magazines and newspapers was fed as 23% of their ration to sheep for 175 days. A similar ration containing oat hulls in place of the paper was fed to control animals. The paper-fed animals consumed 29% more feed than the controls but the feed efficiency (kg animal weight gained/kg ration consumed) of the two rations was approximately equivalent. Lead contained in the paper accumulated in animal tissues. Hepatic microsomal mixed function oxidase activity was several fold higher in the paper-fed animals than the controls. Histopathologic examination of liver and kidney using light and electron microscopy revealed no lesions attributable to diet.

Animal Feed↗

Influence of dietary calcium selenium and methylmercury on eggshell thickness in Japanese quail.

A high Ca, semi-purified diet promoted greater egg production with thicker shells in Japanese quail hens. 7 ppm of dietary Se depressed egg weights with no effect on eggshell thickness. The addition of 20 ppm of MHg to either a low or high Ca diet containing Se depressed both egg production and eggshell thickness. Se residues of liver, kidney, and brain in Se-MHg fed quail were significantly higher than in Se treated quail, probably reflecting the ability of Se to bind with Hg. CA, an enzyme required for the formation of the carbonate radical of Ca carbonate in eggshells, was not reduced in the Se-MHg treated Japanese quail hens' blood or oviducts.

Animals↗

Residues of Dacthal herbicide in carrots.

Residues of Dacthal and its monoacid and diacid hydrolytic ester cleavage metabolites were determined in carrots to which the herbicide was applied on seven plot locations throughout the United States. Residue levels of Dacthal appeared more closely related to the rate of application than to other field parameters. Traces of the monoacid metabolite were found in a few samples. The diacid metabolite was not detected in any of the samples.

Herbicides↗

A water-extractable toxic compound in vinyl upholstery fabric.

A compound, highly toxic to goldfish, was found to be released from a vinyl (polyvinyl chloride) automotive upholstery fabric when the material was immersed in their water. The compound, a flame retardant used in such material, was identified by specific detector gas chromatography and mass spectrometry as triphenyl phosphate. Fish exposed to the immersed fabric or pure triphenyl phosphate showed neurologic intoxication and extensive histopathologic lesions.

Animals↗

Effect of diet on the hepatotoxicity of polybrominated biphenyls (FireMaster PB-6).

The consumption of diets formulated with Cruciferae vegetables, e.g., cauliflower, cabbage, and Brussels sprouts, has been shown to result in a stimulation of the intestinal and hepatic microsomal enzyme systems in rats. This study was designed to determine if this increase in intestinal and hepatic microsomal enzyme activity affected the hepatic response to polybrominated biphenyls (PBB). After three weeks of consuming either a semipurified or 25% cauliflower leaf-supplemented diet (CLD), male Sprague-Dawley rats were maintained for an additional 20 days on their respective diets containing either 0, 1, or 50 ppm PBB. A significant decrease in body weights, but not feed efficiency, was observed over all levels of PBB in animals consuming CLD compared to semipurified diets; consumption of up to 50 ppm of PBB had no effect on body weights with either diet. Relative liver weights (RLW), hepatic aryl hydrocarbon hydroxylase (AHH), N- and O-demethylase, as well as intestinal AHH were all increased in CLD-consuming animals before the addition of PBB. While PBB supplementation alone resulted in increased RLW, hepatic AHH, N- and O-demethylase, microsomal protein, and cytochrome P-450, rats consuming cauliflower diets + PBB had even higher RLW and N- and O-demethylase activity and microsomal protein concentrations. Hepatic PBB residue and total hepatic lipids were significantly reduced in CLD groups receiving 50 ppm PBB. These results suggest that the antitoxic effects of certain vegetables are related to more rapid metabolism and excretion of xenobiotic compounds.

Animals↗

Accumulation of mercury and selenium in tissues of kittens fed commercial cat food.

Six kittens, three males and three females, were fed exclusively for one hundred days a commercially canned red meat tuna found to contain elevated concentrations of Mercury (Hg) and Selenium (Se). A similarly sized control group was fed for the same period a dry commercial cat food comparatively low in the concentration of these elements. At the end of the feeding trial, concentrations of Hg Se were markedly higher in blood, bone, brain, kidney, liver, muscle and spleen of the kittens fed the tuna diet as compared to the corresponding controls. No behavioral abnormalities or pathological lesions were detected in any of the kittens.

Animal Feed↗

Lead and other elements in tissues of guinea pigs fed crown vetch grown adjacent to a highway.

Forty-four elements were determined in crown vetch sampled along a heavily travelled highway in Virginia. Twenty-four elements including Ba, Br, Cr, Pb, Sn, and Sr were higher in this vegetation than in control vetch. When the highway-grown vetch was fed as 45% (dry weight) of the diet to guinea pigs for 100 days, Ba, Br, Cr, Pb, Sn and Sr were found at higher concentrations in the various animal tissues than in those of guinea pigs similarly fed the control crown vetch.

Animal Feed↗