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Biomedical subjects

T Waner

Publications and source records attributed to T Waner.

At least 73 records · Page 4Linked to original sources

Spontaneous ameloblastic fibro-odontoma in a female mouse.

A spontaneous ameloblastic fibro-odontoma is described in a 73-wk-old female mouse. The tumor was located in the molar mandibular region. The diagnosis was made on the basis of the histologic presence of odontogenic epithelial tissue embedded in mesodermal tissue resembling dental papilla, and containing in addition dentin and enamel. The positive reaction for keratin and vimentin confirmed the presence of ectodermal and mesodermal elements respectively in the tumor.

Animals↗

Population distribution profiles of the activities of blood alanine and aspartate aminotransferase in the normal F344 inbred rat by age and sex.

Data on the blood enzyme activities of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) were collected from control male and female F344 rats participating in toxicity studies at 17, 30, 56, 80 and 106 weeks of age. The data were skewed to the right with significant deviation from normality. Applying the Box-Cox transformation, it was concluded that approximately normal distributions could be obtained by using the reciprocal transformation. In general, the males showed a greater degree of heterogeneity for both enzymes. Enzyme activities at 17 weeks were lowest for both ALT and AST. There was a high correlation between the activities of blood ALT and AST, with some animals showing dramatic transient increases. Significant differences among studies with respect to the enzyme activities in rats of the same age were demonstrated.

Aging↗

Spontaneous uterine granular cell tumour in a Fischer 344 rat.

The microscopic features of a spontaneous uterine granular cell tumour in a Fischer 344 rat are described. The location of the tumour is novel for the rat. The neoplasm is characterized by the presence of cells with cytoplasmic granules which were PAS positive and diastase resistant. Electron microscopy and immunohistochemistry results are presented and the origin of the tumour is discussed.

Animals↗

Gingival hyperplasia in rats induced by oxodipine--a calcium channel blocker.

Oxodipine, a new calcium channel blocker, induced gingival hyperplasia in rats. This is the first time that a calcium channel blocker has been documented as resulting in gingival hyperplasia in rats. In contrast to diphenylhydantoin, the hyperplastic changes induced by oxodipine were not precipitated by any prior irritation. The histology consisted of purely fibroblastic proliferation without infiltrate of inflammatory cells.

Animals↗

Drug-induced decrease of serum alanine and aspartate aminotransferase activity in the rat, as a result of treatment with oxodipine, a new calcium channel blocker.

Chronic oral administration of oxodipine, a new calcium channel blocker, resulted in a reduction in the blood enzyme activity of alanine and aspartate aminotransferase. The reductions were both time and dose related. The decline in enzyme activities was accompanied by microscopic hepatic changes, which in the opinion of the authors should have been associated with an increase in the enzyme activities of alanine aminotransferase and aspartate aminotransferase. The effect was only partially reversed one month after the cessation of oxodipine treatment.

Alanine Transaminase↗

Toxicity study in rats of a tellurium based immunomodulating drug, AS-101: a potential drug for AIDS and cancer patients.

Male and female Sprague Dawley rats were injected intraperitoneally for 4 weeks with ammonium trichloro (dioxyethylene-0-0'-) tellurate, an immunomodulating drug at doses ranging from 3 to 24 mg/kg/week. Routine laboratory examinations included body weight, food consumption, clinical chemistry and hematological examinations. At termination of the experiment, all rats were sacrificed and subjected to a detailed necropsy. Few mortalities were recorded during the course of the study. Clinical signs included hind limb paresis and paraphimosis. A garlic odor pervaded the room. Body weight and food consumption were adversely affected in a dose-related manner. Effects were elicited on the hematological system; changes being noted in the platelet and leukocyte counts as well. Clinical chemistry evaluation revealed signs of hepatoxicity, especially in the female treated groups. The level of beta-globulin was increased. At necropsy organs were found to have a grayish-blue discoloration. Tellurium related histopathological changes were observed in the eyes, liver, thymus, bone marrow, heart and kidneys. An attempt has been made to compare the toxicity of this drug with other tellurium-containing compounds. A good correlation was found. Novel effects of the drug were retinopathy and replacement of bone marrow by bony or fibrous tissue. The possibility that some of the effects may have been elicited due to selenium-vitamin E deficiency has been considered.

Acquired Immunodeficiency Syndrome↗

Quantitative evaluation of chlortoluran-induced splenic hemosiderosis by means of an image analyzer.

This study investigated a technique for the quantification of hemosiderin layed down in the spleen. The model used was the rat to which the urea-based herbicide chlortoluran was fed for 90 days. There was good correlation between hematological, biochemical, histological and image analytical techniques when splenic hemosiderosis was of a moderate to severe degree. Where hemosiderosis was of a slight nature, only the technique of image analysis was able to detect the on-going changes.

Animals↗

The renal carcinogenic effect of Merpafol in the Fischer 344 rat.

Three groups of Fischer 344 rats were fed Merpafol (Makhteshim, Israel), an agricultural fungicide, in increasing concentrations for a period of 2 years. A control group was maintained under identical conditions, but without the addition of the fungicide in the diet. A range of nonneoplastic and neoplastic lesions were observed in the kidneys of rats fed Merpafol. The histogenesis of the renal tumors is discussed in relation to chemical-induced epithelial hyperplasia and cystic tubular dilation. Comparative aspects of renal cyst development and carcinoma in humans are also discussed.

Adenoma↗

Reference blood chemical values in ostriches (Struthio camelus).

Reference blood chemical values were determined for 65 male and 61 female ostriches (Struthio camelus) 1 month to 72 months of age. Plasma values of glucose, total protein, triglycerides, cholesterol, uric acid, urea, bilirubin, creatinine, osmolality, electrolytes, and enzyme activity were determined. In general, differences in various values appeared mainly among age groups and less so between sexes. Older ostriches had lower plasma glucose values and enzyme activity than did younger ostriches. High plasma sodium and chloride concentrations in young ostriches correlated with high plasma osmolalities. Plasma calcium values were lower in laying ostriches. Uric acid concentrations were markedly higher than were urea concentrations in all ostriches.

Age Factors↗

Gingival hyperplasia in dogs induced by oxodipine, a calcium channel blocking agent.

Subchronic oral exposure of dogs to Oxodipine, a new calcium channel blocker of the dihydropyridine-type, resulted in dose-related gingival hyperplastic changes. The doses at which an effect was elicited were 24 and 73 times the intended therapeutic dose for man. The effects were first noted after 7 weeks of treatment, and were limited to the high and intermediate dose groups of both sexes. Macroscopically, a generalized enlargement of the maxillary and mandibular facial and lingual gingivae were noted. The histological changes were similar to those described in man for Nifedipine and hydantoin-related drugs. An increase in the activity of alkaline phosphatase and a decrease in alanine aminotransferase was demonstrated. This article is the first to describe gingival hyperplasia in dogs induced in a dose-dependent manner by a calcium channel blocker.

Alanine Transaminase↗

Thyroxine (T4) and triiodothyronine (T3) levels in the Fischer 344 inbred rat.

Plasma levels of T3 and T4 were measured in male and female Fischer 344 (F344/Cr1) inbred rats aged 10, 17, 30, 56, 80 and 106 weeks in order to document the hormone profile of this strain of rat. In general, levels of T4 were higher in males than in females. Levels of T3 were lower in females for the first 17 weeks, similar for rats of age 30 weeks, and thereafter higher in the females than the males. T4 concentration decline was age-associated in both sexes. T3 levels declined in the males only, but remained relatively constant in the females throughout their lifespan. Generally, T4/T3 ratios declined throughout the lifespan of the Fischer rat.

Aging↗

Induction of gastrointestinal tumors in mice fed the fungicide folpet: possible mechanisms.

Dietary administration of the fungicide folpet, N-(trichloromethylthio) phthalimide, to B6C3F1 mice at dose levels of 1,000, 5,000 and 10,000 ppm induced a dose-related appearance of duodenal atypical hyperplasia, adenomas and adenocarcinomas. The appearance in some of these animals of gastric papillomas and gastric squamous cell carcinomas was correlated in many instances to the presence of duodenal obstructions. It is suggested that the gastric lesions appeared subsequent to, and as an indirect result of, these partial lumenal duodenal obstructions. We suggest that the presence of duodenal obstructions is consistent with the notion that reflux of folpet, bile acids and pancreatic enzymes into the stomach may have acted to irritate and consequently stimulate local neoplastic proliferation. In addition, the duodenal obstructions may have resulted in delayed emptying time of the stomach contents with consequential stagnation. This would cause high concentrations of folpet to act locally on the gastric mucosa.

Adenocarcinoma↗

Constipation and megacolon in rats related to treatment with oxodipine, a calcium antagonist.

The constipatory effects of oxodipine, a dihyrdopyridine-type calcium antagonist, have been described in a 3-mo, 12-mo, and 30-mo feeding toxicity study in rats. This paper reports the occurrence of megacolon in rats as a result of the constipatory effects of chronic administration of oxodipine. The first mortality due to oxodipine was seen after about 1 yr of treatment at a dose of 225 mg/kg/day. The toxic effects noted were dose-, time-, and sex-related. Female rats appeared more sensitive to the constipatory effects of the drug. The dose at which the effect occurred in both male and female rats was from about 75 to 675 times the recommended therapeutic dose for humans. To the best knowledge of the authors, this is the first report of a calcium channel blocker causing constipation in rats.

Animals↗