Publications by authors named "Nakanowatari J"

A peripherally located primitive neuroectodermal tumor (peripheral PNET) originating in subcutaneous tissues was observed in an adult Beagle. The highly aggressive tumor spread rapidly and metastasized to various organs. The neoplasm was diagnosed as a peripheral PNET on the basis of morphologic and immunohistochemical characteristics such as small round tumor cells, rosette formations, many interdigitating cytoplasmic processes, neurosecretory granules and microtubules, and positive immunohistochemical reactions to neurogenic markers.

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A giant cell tumor (GCT) was detected on the distal end of the femur in a 98-wk-old male Fischer 344 rat. The yellowish white mass had expanded, compressing adjacent muscle tissues. The tumor had an osteolytic and relatively homogeneous appearance and was composed of multinuclear giant cells scattered in a mass of mononuclear stromal cells.

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Gamma-Carboxyglutamic acid (Gla)-containing protein, synthesized in the presence of vitamin K, has been found in atherogenic plaques, but the pharmacological effect of vitamin K on atherosclerosis is unclear. We examined whether vitamin K2 (menatetrenone) could affect the progression of both atherosclerosis and hypercoagulability in hypercholesterolemic rabbits. Vitamin K2 in daily doses of 1, 10 and 100 mg/kg was given with a 0.

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The incidence of invasive spontaneous pituitary carcinomas in Fischer-344 rats were studied. The pituitaries were examined histopathologically together with surrounding tissues including sphenoid bone. The incidence of carcinoma was higher than that previously reported in Fischer-344 rats.

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Induction of cytochrome P-450 PCN (P-450 PCN) by non-steroidal compound, M79193 (cyclohexane spiro-2,6-chloro-1'-(3-dimethyl-aminopropyl) spiro(chroman-4,4'-imidazolidine)-2',5'-dione], was investigated in both sexes of rats. The immunohistochemical localization of P-450 PCN was also studied in liver lobules of untreated and M79193-treated male rats. Immunoblot analysis of rat liver microsomes with anti-P-450 PCN indicated that the amount of P-450 PCN increased 5- to 7-fold by the treatment with M79193, but no increase was observed in P-450 PB-1 (P450IIB1) or P-450 MC-1 (P-450IA1).

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The effect of clofibrate (CF) on proliferation of diethylnitrosamine (DEN)-initiated glutathione S-transferase placental form (GST-P)-positive preneoplastic and neoplastic lesions as studied in male F344 rats. Animals were given a single i.p.

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Differences in susceptibility of the urinary bladder epithelium to N-butyl-N-(4-hydroxybutyl)-nitrosamine (BBN) in various strains were examined. In experiment 1, 5 strains of male rats were given 0.025% BBN in the drinking water for 8 weeks followed by drinking water without BBN for 32 weeks.

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Differences in the susceptibilities to sodium saccharin of the urinary bladder epithelium in various strains of rats and other animal species were examined. In Experiment 1, male ACI, Wistar, F344 and Sprague-Dawley rats were administered 5.0% sodium saccharin in the diet for 52 weeks.

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Four groups of 21 male Wistar rats were given weekly subcutaneous injections of 1,2-dimethylhydrazine at a dose of 20 mg/kg body weight for 2, 4, 6 and 8 weeks, respectively, and 7 animals of each group were killed in weeks 24, 32 and 40. This treatment induced a clear dose-related increase in the total number of colonic carcinomas. The number of tubular adenocarcinomas, which were mostly located in the descending colon, was clearly dose-related, whereas the number of signet ring cell carcinomas, which developed in the ascending colon, was apparently dose-independent.

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The histochemistry of mucin in normal large intestine and in experimental colorectal cancers induced in Wistar rats with 1,2-dimethylhydrazine was analyzed by modifications of the concanavalin A-horseradish peroxidase method (paradoxical concanavalin A-staining) and high-iron diamine-Alcian blue (pH 2.5) staining (HID-AB). Quantitative analysis of each mucin reaction was done by the use of an image analyzer.

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The effect of partial cystectomy on the occurrence of pre-neoplastic lesions, papillary or nodular hyperplasia (PN hyperplasia), of the bladder in male F344 rats was studied in an experiment in which bladder carcinogens and promoters were given to the rats after initiation with BBN. The bladder carcinogens tested were N-ethyl-N-(4-hydroxybutyl)nitrosamine (EHBN) and N-4[4-(5-nitro-2-furyl)-2-thiazolyl]formamide (FANFT) and the bladder promoters were sodium saccharin, sodium cyclamate, and DL-tryptophan. Partial cystectomy significantly decreased the occurrence of PN hyperplasia in rats treated with EHBN and tended to inhibit that in rats given saccharin or tryptophan.

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The behavior of hyperplastic nodules following an in vivo short-term screening test for hepatocarcinogens was studied. Rats were injected ip with 200 mg/kg body weight of diethylnitrosamine (DEN), given basal diet containing 200 ppm of N-2-fluorenylacetamide (2-FAA) (group 1), 1000 ppm of the alpha-isomer of 1,2,3,4,5,6,-hexachlorocyclohexane (alpha-BHC) (group 2) or basal diet (group 3) from week 3 to week 8, and then given basal diet and tap water. They were subjected to partial hepatectomy at the end of week 3.

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The carcinogenic effects of aniline and norharman given alone or in combination were examined in rats. Neoplastic changes including hyperplastic changes of the urinary bladder were not found in all groups. Papillomas of forestomach were observed in 5 rats out of 110 rats.

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