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Biomedical subjects

G A Maylin

Publications and source records attributed to G A Maylin.

At least 19 recordsLinked to original sources
PubMed1990

Absence of cadmium in the blood of horses fed oats grown on municipal sludge-amended soil.

Effluents from a number of industries which are typically treated in municipal sewage plants result in cadmium-containing sludge. Disposal of such sewage sludge by application to agricultural land can result in uptake of cadmium by crops. In this study, oats were grown on soils which had been amended with sewage sludge from Syracuse, New York. The cadmium concentration in the sludge-grown oats was 1.79 ppm dry weight. Horses were fed the sludge-grown oats for 6 weeks during which time blood samples were taken for the determination of cadmium. No significant differences (p greater than 0.05) were found in the concentration of cadmium in the blood of the horses consuming the oats compared with that in the blood before feeding began (control). The well-known efficient accumulation of renal cadmium by horses may account for a lack of significantly increased cadmium in blood during the feeding period.

Animal Feed↗
PubMed1989

Changes in articular cartilage after intra-articular injections of methylprednisolone acetate in horses.

Eight mature horses with no prior signs of joint disease or history of intra-articular therapy were treated with 8 weekly intra-articular injections of methylprednisolone acetate. Treatments were given at a dose of 120 mg/joint into the right radiocarpal and intercarpal joints, with the left joints as untreated controls. Articular cartilage samples were obtained at necropsy 1, 4, and 8 weeks after the last injection. Compared with controls, cartilage from injected joints had a loss of hematoxylin basophilia and decreased intensity of staining in safranin O fast green dye. Chondrocyte necrosis and hypocellularity were observed in all samples of cartilage from treated joints. Proteoglycan content and its rate of synthesis were reduced. There was a progressive loss of proteoglycan content, whereas proteoglycan synthesis increased somewhat 4 and 8 weeks after treatment. Collagen content was unchanged, but its rate of synthesis was markedly inhibited. Collagen synthesis did not recover, but remained decreased at 5 to 15% of the values from untreated cartilage. Water percentage was increased, but fibronectin content was not significantly different. A single injection of methylprednisolone acetate was also given into the right metacarpophalangeal joints of 3 of the 8 horses in this group, with the left joints serving as untreated controls. Sixteen weeks after the treatment, cartilage of the treated joints had a loss of histochemical staining and proteoglycan content was reduced to 50% of control values. The mean rate of proteoglycan synthesis and mean fibronectin content were increased, but the differences were not statistically significant (P greater than 0.05). Other variables were essentially unchanged.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1987

Background lead levels in dairy cattle: updated values for 1986.

Lead poisoning continues to be a problem in cattle. The toxicologic significance of blood lead levels requires the differentiation of background blood lead from toxic levels. A ten-fold variation of background blood lead levels reported in previous studies has prompted us to conduct our own survey. Our results indicate significantly lower background blood lead levels in New York State cattle analyzed in 1986 than in those levels previously reported elsewhere.

Animals↗
PubMed1987

Fluoride intoxication in dairy calves.

Chronic fluoride intoxication in dairy cattle, caused by feeding fluoride contaminated commercial feed, was previously described in a dairy herd. Dental fluorosis and a catastrophic decrease in milk yield were the foremost findings. In calves born to the fluoride intoxicated cows, congenital fluorosis was manifested by brown discoloration of enamel, enamel hypoplasia, brown mottling of bone, severe retardation of cartilage cell differentiation, atrophy of osteoblasts, osteopenia, atrophy of bone marrow cells, serous atrophy of bone marrow fat and severely stunted growth.

Animal Feed↗
PubMed1986

Toxic and protective constituents in pet foods.

An analytical survey of mutagens, nitrosamines, polychlorinated biphenyls, toxic elements, and gamma-emission, as well as the toxicologically protective constituents zinc, selenium, and vitamin C, in 48 pet foods was conducted. Aside from high concentrations of fluoride and iodide in some samples and the expectedly higher concentrations of mercury and selenium in certain cat foods containing fish, the samples were notably free of the other toxic constituents. Direct-acting and promutagens and nitrosamines were not detectable in any of the samples. gamma-Emission was very low in all of the foods. Polychlorinated biphenyls were only detected in one cat food.

Animal Feed↗
PubMed1986

Toxic effects of food-borne fluoride in silver foxes.

Chronic ingestion of excessive amounts of fluoride from commercial fox food is associated with agalactia in vixens resulting in the starvation deaths of large numbers of kits in three fox herds. Evidence of infectious disease or poor management could not be found and a causal relationship between fluoride and high kit mortality is suggested.

Animal Feed↗
PubMed1986

Milk production of cows fed fluoride contaminated commercial feed.

A commercial feed concentrate and a mineral mix with excessive amounts of fluoride were introduced into a Holstein dairy herd with an average milk production well above national standards. Milk production decreased drastically, and during the following 6 years the deficit in milk production in the herd ranging from 52 to 120 milking cows was 1.5 million Kg (3 1/4 million lbs.). The tolerance levels set by the National Academy of Sciences for fluoride ingestion by lactating cow were found to be inadequate.

Animal Feed↗
PubMed1984

Analysis of propionylpromazine and its metabolites in horse urine.

The metabolism of propionylpromazine in the horse was studied. Although propionylpromazine is not currently approved or recommended for use in horses, it has been used illegally to alter their performance. Propionylpromazine hydrochloride was administered intramuscularly at clinical and subclinical doses. Three metabolites were detected in urine. The major metabolite was identified as 2-(1-hydroxypropyl) promazine sulfoxide. The detection of this metabolite in routine drug testing has been described.

Animals↗
PubMed1984

Vascular pathology in phenylbutazone intoxicated horses.

Three mature Thoroughbred geldings were given 13.63 mg phenylbutazone/Kg bodyweight intravenously for 3 days and repeated in one horse 4 days later. After 4, 7 and 10 days (double treatment), degeneration of the wall of small veins occurred in all horses. The veins were dilated and/or showed hyalin degeneration. The phlebopathy was interpreted to be paramount in phenylbutazone intoxication. All other manifestations, including erythro- and leukodiapedesis, submucosal edema and ulceration of the gastrointestinal mucosa, phlebothrombosis and significant changes in the hemogram and serum chemistry, were considered secondary to the vein lesions.

Animals↗
PubMed1983

Determination of drugs in biological samples by thin-layer chromatography-tandem mass spectrometry.

In this work thin-layer chromatography-tandem mass spectrometry (TLC-MS-MS) allowed detection and confirmation of caffeine and nicotine in human urine and of butorphanol, betamethasone, and clenbuterol in equine urine. In most cases of trace analysis of labile compounds the drugs could not be identified unless they were developed on a TLC plate, scraped from the plate and the TLC scrape eluted with a suitable organic solvent prior to MS-MS. Usually a sample prepared in this way still had several components in it, but was sufficiently cleaned up to allow collision-induced dissociation (CID) experiments to unequivocally identify the drug. In contrast, trace levels of labile drugs could not be identified by CID experiments either directly from the raw urine extracts or by thermally desorbing them from the TLC scrape.

Animals↗
PubMed1983

Dental fluorosis in cattle.

Five expressions of dental fluorosis are described in cattle exposed to industrial fluoride pollution: 1. Hypercementosis with tooth ankylosis, cementum necrosis and cyst formation; 2. Delayed eruption of permanent incisor teeth; 3 Necrosis of alveolar bone with recession of bone and gingiva; 4. Oblique eruption of permanent teeth, hypoplasia of teeth with diastemata; and 5. Rapid progression of dental lesions. The five entities are not recognized in the "standard for the classification of dental fluorosis" by the National Academy of Sciences. Since this classification it too limited and superficial, adherence to this standard has left severe cases of fluoride intoxication in cattle undetected in field surveys.

Alveolar Process↗
PubMed1982

The extraction and isolation of dexamethasone-related compounds.

Radiolabeled dexamethasone (9-fluoro-16 alpha-methyl-11 beta, 17, 21-trihydroxy-1,4-pregnadiene-3,20-dione) was utilized to develop a practical and relatively expedient method of detection for dexamethasone and its major metabolite in horse urine. The effects of solvent, pH, salt saturation, and back extraction on the extraction efficiency of dexamethasone-related compounds and the presence of endogenous background were evaluated. Final isolations of dexamethasone and its major urinary metabolite were procured by successive thin-layer chromatography (TLC) in three different developing systems.

Animals↗
PubMed1982

Milk production of cows exposed to industrial fluoride pollution.

Milk sales records for a dairy herd showed that milk production did not decrease during the first 4 yr of exposure of cows to fluoride pollution from an aluminum plant. During the next 3 yr milk production decreased, but not significantly. From yr 8 of exposure there was a significant decrease, which persisted through yr 19, when the dairy operation was terminated. From yr 15 through yr 19, the milk yield averaged less than 60% of the expected value.

Aluminum↗