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Biomedical subjects

H Onodera

Publications and source records attributed to H Onodera.

At least 307 records · Page 17Linked to original sources
PubMed1984

Spontaneous tumors of the nervous system and associated organs and/or tissues in rats.

Spontaneous tumors of the nervous system and associated organs and/or tissues in 346 male and 346 female F344/DuCrj rats and 200 male and 177 female Slc:Wistar rats were examined. The main neurogenic tumors observed were gliomas and neurinomas, which were detected in both strains of rats. Out of 7 gliomas, 6 were found in the brain and 1 in the spinal cord, and out of 4 neurinomas, 2 were in the trigeminal nerves and the other 2 were in the spinal nerves. In addition, other types of tumors (2 granular cell tumors in the brain, 1 pinealoma, 3 ganglioneuromas in the adrenal gland, 1 undifferentiated carcinoma in the nasal cavity and 1 chordoma in the posterior neck region) were observed.

Animals↗
PubMed1984

Carcinogenicity of low doses of N-ethyl-N-nitrosourea in F344 rats; a dose-response study.

The threshold level of minimum carcinogenic dose of N-ethyl-N-nitrosourea (ENU) and the effect of dose on organ specificity were examined by continuous oral administration to both sexes of F344 rats of low doses of ENU at four concentrations (0.3, 1, 3 and 10 ppm) in the drinking water. ENU at 10 ppm selectively induced neurogenic tumors and tumors of the digestive tract, including duodenal tumors. Even at lower doses it enhanced the spontaneous development of some other tumors. A high dose of ENU (400 ppm) was previously found to induce duodenal tumors selectively. These results indicate that the organ specificity of ENU is influenced by the dose and that ENU has multi-potent carcinogenic activity in many organs and/or tissues. In this study, some specific tumors, such as those of the nervous system and digestive tract, seemed to require a minimum carcinogenic level of ENU (10 ppm) for their appearance. However, it seems that ENU is carcinogenic at much lower dose levels than 10 ppm because ENU enhanced the spontaneous development of some other tumors in many experimental groups. The so-called virtually safe doses inducing these specific tumors at a risk level of 10(-6) were calculated.

Animals↗
PubMed1983

Correlation of the real-time ultrasonographic appearance of hepatic hemangiomas with angiography.

The ultrasonographic appearance of hepatic hemangiomas was studied in 19 patients (31 lesions). The detectability rate by real-time ultrasonography was 77%. A hyperechoic, sharply-marginated and internally homogeneous lesion is highly suggestive of hemangioma. If the hypoechoic lesion has homogeneous internal echoes and/or strong marginal echoes, it is also suggestive of hemangioma. It is difficult to detect small lesions in the lower lateral part of the right lobe and lesions in the right lobe immediately under the diaphragm. Computed tomography should be the next procedure of choice in the evaluation process. If the computed tomography is not characteristic, angiography should be done to confirm the diagnosis.

Adult↗
PubMed1983

Induction of tumors in the small intestine and mammary gland of female Donryu rats by continuous oral administration of N-carboxymethyl-N-nitrosourea.

The carcinogenicity of N-carboxymethyl-N-nitrosourea (CMNU), a naturally occurring N-nitroso compound, was tested in female Donryu rats. Four groups of female Donryu rats were given 400, 200, 100, or 0 ppm of CMNU solution continuously as drinking water. The incidence of tumors was highest and the mean survival time shortest in the 400 ppm group. A dose-effect relationship was observed in the tumor incidence and the mean survival time and the incidences of tumors in all experimental groups were significantly different from those in the control group. In the 400 ppm group, tumors were detected most frequently in the small intestine, followed by the mammary gland. In contrast, most tumors were observed in the mammary gland in the other two experimental groups, although dose-dependent induction of tumors of the small intestine was also detected in these two groups. The organ specificity of CMNU is compared with that of other N-alkyl-N-nitrosourea derivatives.

Animals↗
PubMed1983

Carcinogenicity study of ammonia-process caramel in F344 rats.

The carcinogenicity of ammonia-process caramel, a food colouring, was examined in F344 rats. Caramel was dissolved in distilled water at levels of 0, 1 and 4% and groups of 50 male and 50 female rats were given 20-25 ml of one of these solutions/rat/day as their drinking water for 2 yr. There were no significant differences between the total incidences of tumours or mean survival times of control and experimental groups. A variety of tumours developed in all groups including the control group, and no dose-related effects were found either in the incidence or induction time of tumours in the various organs and tissues except in the pituitary gland of males, in which the incidence of tumours in males given 4% caramel solution was significantly higher than that in controls. Pituitary tumours are among the most common spontaneous tumours in ageing rats of this strain and have a variable incidence. In addition, almost all pituitary tumours detected in males given the 4% solution were microscopic tumours, and there was no significant difference between controls and treated groups in the incidence of hyperplasia or pre-neoplastic lesions in the pituitary gland. These results indicate that the significantly higher incidence of pituitary tumours in males given the 4% caramel solution was not related to caramel administration, but could be explained by the variability of the incidence of spontaneous pituitary tumours. Thus it is concluded that under these experimental conditions ammonia-process caramel was not carcinogenic in F344 rats.

Age Factors↗
PubMed1983

Diurnal profile of gallbladder size in diabetic patients: ultrasonographic evaluation of diabetic neurogenic gallbladder.

The diurnal change of gallbladder size was clearly measured with a real time ultrasonography. To visualize the gallbladder, 21 diabetic patients and 11 healthy subjects were scanned right subcostally in the supine position nine times between 8:00 a.m. and 8:00 p.m. Photographs of the images were produced on Polaroid film, and the area of gallbladder was calculated. The diurnal changes of the gallbladder size were expressed as the percentage of the size measured at 8:00 a.m. after an overnight fast. The gallbladder in normal control started contracting immediately after breakfast and reached 57.2 +/- 7.6% at 9:00 a.m. In the diabetic patients with and without autonomic neuropathy the gallbladder contracted to 80.9 +/- 14.5% and 72.4 +/- 14.8%, respectively, at 9:00 a.m. while the nadir of the diurnal profile curve in healthy subjects was 24.5 +/- 3.6% at 3:00 p.m., in the diabetic patients with and without autonomic neuropathy those were 57.7 +/- 6.1% at 6:00 p.m. and 41.3 +/- 8.3% at 8:00 p.m., respectively. This implies that the gallbladder contraction was delayed and poor in diabetic patients. In this paper, the gallbladder tonicity index is proposed, which is useful for the easy evaluation of autonomic state of gallbladder in diabetes mellitus.

Adolescent↗
PubMed1983

Microautoradiographic study on the tissue localization of liposome-entrapped or unentrapped 3H-labeled beta-galactosidase injected into rats.

The localization of intravenously injected liposome-entrapped or unentrapped 3H- beta-ga lactosidase in various tissues of rats was investigated by microautoradiography. The microautoradiographic silver grains, indicating the uptake of both forms of the enzyme were observed in all of the rat tissues studied, such as the liver, kidneys, spleen, lungs, heart, muscle and brain. The liver was found to be the most active in taking up both forms of the enzyme and probably Kupffer cells were primarily involved in the uptake of the enzyme. Also in the brain, the uptake of both forms of the enzyme was observed, though far less extensively, through the blood-brain barrier. The uptake of the enzyme in the brain was somewhat greater in the gray matter than in the white matter.

Animals↗
PubMed1983

Ultrasonic endoscopy.

With the use of a linear scan type ultrasonic endoscope, the possibility of gastric fiberscopy with ultrasonic procedure in the estimation of the extent of deep infiltration of gastric cancer and in the transgastric diagnosis of pancreatic tumors was studied. Results revealed that the echogenicity of the tumor was more clearly recorded by ultrasonic endoscopy than routine ultrasonography taken via the abdominal wall. With improvements in both the probe and manipulation technique, the device is expected to achieve far-reaching contributions to the diagnosis of the deep invasion of gastric cancer and small-sized pancreatic tumors.

Adult↗
PubMed1983

Neoplastic and non-neoplastic lesions in aging Slc: Wistar rats.

Spontaneous neoplastic and non-neoplastic lesions in 98 male and 100 female Slc: Wistar rats, which have been widely used in Japan for toxicological studies, were examined. As spontaneous tumors, the most frequent tumors in males were testicular interstitial cell tumors, followed by tumors of the hematopoietic organs, adrenal gland, thyroid gland, preputial gland, pituitary gland, liver and mammary gland. Those in females were tumors of the pituitary gland, mammary gland, hematopoietic organs, uterus and thyroid gland. The organ distribution and histological types of spontaneous tumors observed in Slc: Wistar rats were very similar to those in F-344/DuCrj rats, although the incidences of some tumors differed slightly in the two strains. Various non-neoplastic lesions were also observed in the heart, kidney, liver and many other organs. These results should be useful in evaluating the results of toxicological and carcinogenic studies on this strain of rat.

Animals↗