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Biomedical subjects

N H Altman

Publications and source records attributed to N H Altman.

At least 55 records · Page 3Linked to original sources
PubMed1986

Topical fluorouracil. II. Postoperative administration in an animal model of glaucoma filtering surgery.

Unilateral posterior lip sclerectomies were performed in ten owl monkeys. Five milligrams of fluorouracil was injected subconjunctivally in each operated eye immediately after surgery. Three drops (approximately 2.4 mg/drop) of fluorouracil were instilled ten minutes apart in each operated eye twice daily on postoperative days 1 through 7 and once daily on postoperative days 8 through 15, 17, 19, and 21. One monkey died on the seventh postoperative day; its death could not be attributed to systemic fluorouracil toxicity. All of the operated eyes had filtering blebs after the full course of fluorouracil, but seven also had corneal epithelial defects. By the seventh postoperative week, two of the operated eyes manifested moderately severe corneal opacification. Ten weeks postoperatively, the electroretinographic a- and b-wave amplitudes averaged 17% and 12% less, respectively, in the seven operated eyes without clinically significant corneal opacification than in the unoperated fellow eyes. Only two eyes had blebs after the 12th postoperative week. Histopathologic examination was performed on five eyes, of which only two revealed patent sclerostomies. Although topical fluorouracil appears to delay bleb scarring, the corneal findings suggest that it may be more toxic than subconjunctival fluorouracil.

Administration, Topical↗
PubMed1986

Focal mucinosis in dogs: seven cases and review of cutaneous mucinoses of man and animals.

Seven dogs had one or more asymptomatic nodules, papules, or plaques on the skin or oral mucosa. The primary histologic feature was the accumulation of excess mucin within the dermis or submucosa. Based upon the clinical presentation and the histopathologic changes, it was proposed that these lesions represent the canine analogue of focal mucinosis in man, and that the same name be applied to the lesion in dogs. The criteria for the diagnosis of focal mucinosis were: (1) the presence of a single (rarely multiple) papule, nodule, or plaque which may be firm, rubbery, or soft, (2) the accumulation of mucin which disrupts and separates collagen fibers, (3) mild to extensive fibroblast proliferation, and (4) a mild mononuclear cell infiltration. The mucinoses of man and animals were reviewed.

Animals↗
PubMed1985

Cardiomyopathy in stranded pygmy and dwarf sperm whales.

Necropsy and histologic examinations were performed in 23 pygmy sperm whales (Kogia breviceps) and 6 dwarf sperm whales (Kogia simus) that had been stranded singly or in cow-calf pairs along the southeastern coastline of the United States. At necropsy, the gross findings in the adult whales included pale, flabby right ventricles. Microscopically, lesions in the hearts of the whales were characterized by moderate to extensive myocellular degeneration, atrophy, and fibrosis. Similar changes were not seen in 5 of 6 sexually immature whales or in the whale calves. Hepatic changes were consistent with heart failure. The cause of the myocardial lesions was not determined. The systemic effects of failing myocardium probably were a major reason for the stranding of the adult whales.

Age Factors↗
PubMed1982

The effect of methionine on the progression of hepatocellular carcinoma induced by ethionine.

Female Wistar rats were fed a semisynthetic diet containing 0.3% DL-ethionine for 52 weeks and, most of them bearing hepatocellular carcinomas, were switched to a basal diet for one week and then received 80 mg DL-methionine per rat (cir. 25 mg/100 g body wt) by gavage once per day, five times a week, over a period of 13 weeks. Methionine treatment significantly affected progression of hepatic tumors induced by DL-ethionine administration. The frequency of rats with hepatocellular carcinomas in the methionine treated group was significantly lower than that in control groups. It therefore appears that methionine treatment resulted in a remission of the malignant process.

Animals↗
PubMed1980

Failure of pure 1-naphthylamine to induce bladder tumors in dogs.

1-Naphthylamine was administered p.o. to beagles for approximately 9 years at a daily dose of 15 mg/kg (5 days a week). At autopsy, no tumors or other pathological changes were observed in the bladders of any of these animals. With the possible exception of the excessive accumulation of lipofuscin in the hepatocytes of these dogs, no test compound-related pathological changes in other tissues of the body were observed. Analysis of the urine revealed the presence of small amounts of N-oxidation products (1-nitrosonaphthalene plus N-hydroxy-1-naphthylamine), ranging from 2.85 to 125 microgram, following a dose of 1-naphthylamine. The theoretical significance of these findings is discussed.

1-Naphthylamine↗
PubMed1979

A spontaneous outbreak of polychlorinated biphenyl (PCB) toxicity in rhesus monkeys (Macaca mulatta): clinical observations.

A spontaneous, progressive disease occurred in a large domestic breeding colony of rhesus monkeys (Macaca mulatta). The disease was characterized by slow but continuous weight loss, alopecia, acne, facial edema, diarrhea and trauma from other monkeys. Breeding efficiency was impaired with a high incidence of abortions and stillbirths. Live offspring were small and unthrifty contributing to a high infant mortality rate. The cause of this disease was polychlorinated biphenyls (PCSs) which were present in the concrete sealant on the cage floors. Removing the sealant and resurfacing the floors alleviated the problem.

Aggression↗
PubMed1978

Suspected ascorbic acid deficiency in a colony of squirrel monkeys (Saimiri sciureus).

Subperiosteal cranial hematomas were observed in five female squirrel monkeys. The absence of trauma in the clinical history, the characteristic clinical changes, and the pathological lesions suggested that the animals were scorbutic. Analysis of feed which was soaked in water, or left on the ground for varying time periods at different temperatures, indicated that there was loss of ascorbic acid. During the manufacture of monkey feed, ascorbic acid is dusted on as a final process. The practice of soaking feed resulted in the "washing off" or the destruction of ascorbic acid. This disease outbreak emphasized the important of management practices in a primate colony.

Animals↗
PubMed1977

Studies of rhesus monkey (Macaca mulatta) hemoglobin.

One hemaglobin was found in the adult rhesus monkey (Macaca mulatta) by the technique of isoelectric focusing. In addition to the adult hemoglobin, one fetal hemaglobin was observed in neonates of the same species. The alpha and non-alpha globins of rhesus monkey hemoglobins showed similar electrophoretic mobilities as those of human hemoglobin A by cellulose acetate membrane electrophoresis. It appeared that the rhesus monkey hemoglobin system is a good model system for the study of human hemoglobin development.

Animals↗
PubMed1977

Identification of hemoglobins within individual rhesus monkey (Macaca mulatta) erythrocytes.

Rabbit and goat antibodies to monkey adult and fetal hemoglobin were prepared and purified to apparent monospecificity. After conjugation with fluorescein isothiocyanate, the antibodies were employed to identify the hemoglobin types within individual cells in peripheral erythrocyte smears. The percentage of neonatal monkey erythrocytes containing fetal hemoglobin was found to decrease with time. The existence of adult or fetal hemoglobin in the erythrocytes appeared to be mutually exclusive.

Age Factors↗
PubMed1976

The influence of DL-methionine on the metabolism of S-adenosylethionine in rats chronically treated with DL-ethionine.

The concentration of S-adenosylethionine in the liver of ethionine-fed rats was increased gradually during the process of carcinogenesis. This increase may have been due to the decreased capacity of the treated rats to acetylate ethionine sulfoxide. Ethionine sulfoxide is considered as the main reserve pool of ethionine for the synthesis of S-adenosylethionine. When the ethionine diet was supplemented by DL-methionine (0.3 to 0.9%), the increase in the concentration of S-adenosylethionine during the period of observation (28 to 150 days) was lower and the acetylation of ethionine sulfoxide was significantly higher. The concentration of the total S-adenosyl compounds in the liver of rats on a diet supplemented with DL-methionine was increased over the concentration of S-adenosylethionine in rats fed ethionine alone, and the S-adenosylethionine portion of this fraction was only about 30% lower. The supplementation of the diet with methionine restored the diurnal oscillation of adenosine 5'-triphosphate in the liver, which had been absent in rats ingesting only ethionine.

Adenosine↗
PubMed1975

The effect of cupric acetate on ethionine metabolism.

The addition of cupric acetate, a potent inhibitor of ethionine carcinogenesis, to a diet containing ethionine increased the ethionine toxicity. The concentration of S-adenosylethionine in liver was found to be significantly higher when compared to animals fed only ethionine in the diet. Ethionine forms a complex(es) with cupric acetate that is insoluble at a pH higher than 4; however, this complex can be solubilized at a low pH. Ethionine, if administered p.o. in the form of this complex, was absorbed from the intestinal lumen in the same order of magnitude as when administered alone; however, as the body weight increased over 200 g, the portion of absorbed ethionine decreased. The absorption of ethionine bound in the complex was completed within 16 hr compared to 2 hr for free ethionine. This time delay was accompanied by a shift in the concentration maximum of ethionine metabolities in the liver form 8 to 24 hr. When ethionine was administered alone, it was metabolized in the intestinal lumen as demonstrated by the analysis of the soluble intestinal contents; the presence of cupric acetate inhibited this process. The chromatographic analysis of ethionine metabolites in urine of rats treated by the complex revealed an increased excretion of ethionine sulfoxide and other ethionine metabolities at the expense of N-acetylethionine sulfoxide. The increased concentration of S-adenosylethionine in the liver in chronic experiments may be, at least partly, a result of a diminished capacity of the rat to detoxify (acetylate) ethionine sulfoxide, which is considered the main reserve pool of ethionine for the maintenance of a high level of S-adenosylethionine.

Animals↗