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Biomedical subjects

N Kuwabara

Publications and source records attributed to N Kuwabara.

At least 73 records · Page 4Linked to original sources
PubMed1991

[Studies of morphometric analysis and cell cycle of gastric epithelia of rat administered minimal mixed bile acids].

The gastric epithelia of the rat after administrated with the minimal mixed bile acids and lysozyme for 9-weeks were studied using morphometric analysis and anti-Bromodeoxyuridine staining immunohistochemistry. Our results show that the atrophic changes and increased anti-BrdU antibody staining positive and mitotic cells of the pyloric glands area in the group administration only bile acids. Lysozyme inhibited bile acids activation on these changes of this area.

Animals↗
PubMed1990

Transplacentally induced anorectal malformations in rats.

Twenty-eight pregnant rats (Wistar-Imamichi) on the 11th gestation day were treated with a single intragastric administration of ethylenethiourea (ETU) of 100, 125, 150, and 200 mg/kg body weight, and received cesarean section on the 20th gestation day. No dam died following the ETU treatment. In these transplacentally treated rat fetuses, various types of externally visible malformations were frequently observed; absent or kinked short tail in 100% and spina bifida or myeloschisis in 48.6% to 86.8%. The incidences of these anomalies were significantly higher in males than females. The fetuses were fixed in Bouin's solution and embedded in paraffin, and the step-serial section were sagittally prepared. Then they were stained with phosphotungstic acid hematoxylin for the light microscopic examination. In a preparation of just midsagittal section, malformations of rectum and anus were investigated. The results were as follows: (1) the most appropriate dose of ETU might be 125 mg/kg, body weight of dam, which was suggested by number of the fetuses, prenatal development of the fetuses and incidences of externally visible anomalies in the fetuses; (2) various types of anorectal anomalies, including rectourethral fistula, rectocloacal fistula, covered anus-complete, anoperineal fistula, and anal membrane stenosis, were induced; (3) the incidence of anorectal anomalies was significantly higher in males than females; (4) in every type of anorectal anomalies, inner circular layer of smooth muscle was hypertrophied at the rectum end, which seemed to be considered as the internal sphincter muscle; and (5) the external sphincter muscle complex was hypoplastic in the high deformity fetuses associated with sacrococcygeal anomaly.

Anal Canal↗
PubMed1990

[Pathological studies of multiple submucosal gastric gland lesions in thirty-eight cases].

We have examined 38 stomachs with the adenocarcinoma and multiple submucosal gastric gland (SG) lesions. Almost the SG lesions consisted of the foveolar epithelium, which stained negative with alcian blue whereas the ordinary glands stained positive with con-A (III), or with both types of epithelium, and they had no atypicality. Only 14 out of 2,188 SG lesions (0.63%) showed atypical proliferation. Three hundred and forty-nine out of 1,535 SG that were examined by lysozyme staining were strongly lysozyme positive. Almost all the propria mucosa in the areas of the minute SG showed erosive lesions with an atrophy of ordinary glands, glandular erosion, and a regenerative epithelium. Eleven stomachs (11/38 cases, 29.0%) had multiple adenocarcinomas.

Adenocarcinoma↗
PubMed1989

Corrosive gastritis mimicking linitis plastica carcinoma.

A 59-year-old female with depressive tendencies was admitted suffering from hematemesis and abdominal pain, two hours after ingestion of an unknown amount of toilet bowl cleaner (hydrochloric acid, pH 1.0). A barium study 24 days after ingestion revealed rigid narrowing and granulation of the entire stomach. The esophagus and duodenum were normal. The radiographic results were similar to those obtained for linitis plastica carcinoma of the stomach, but biopsy specimens of the stomach revealed no cancer cells. A total gastrectomy was performed about two months after ingestion to relieve the persistent feeling of nausea. Specimens revealed a rigid and thickening lining and a denuded mucosal surface of the stomach. The cut surface of the specimen showed a remarkable fibrous thickening of the submucosal layer. Microscopic examination failed to reveal a normal mucosal layer except in a narrow area of the fornix, and remarkable fibrosis of the submucosal lining was noted. No cancer cells were found. Corrosive gastritis has a linitis plastica appearance with a predilection for the antrum. Radiological examination revealed the very rare manifestation of a rigid narrowing of the whole stomach mimicking linitis plastica type cancer.

Adenocarcinoma, Scirrhous↗
PubMed1989

Ovarian cysts in precocious puberty.

We describe a 7-year-old girl with precocious puberty in whom a single large cyst (5 cm) and several small cysts (8-10 mm) in the single remaining ovary were detected by the ultrasound examination. Endocrinological examinations confirmed the diagnosis of central precocious puberty. Pathologic findings after the removal of the cystic lesions revealed that the large cyst was derived from degenerated follicular cysts and the small cysts were identical to follicular cysts: all were considered to have been formed by gonadotropin stimulation. In general, surgical removal of an ovarian follicular cyst in central precocious puberty is inappropriate. However, in this unusual patient who had a degenerated large cyst, surgery seemed to be appropriate because of a previously removed teratoma in the contralateral ovary.

Child↗
PubMed1989

Spontaneous tumors in F-344/Jcl rats.

The age-related incidence of spontaneously occurring neoplastic and non-neoplastic lesions in untreated F-344/Jcl rats, used as controls in carcinogenicity testing, were studied from the histological examination of tissues from 469 males and 354 females. The incidence of spontaneous tumors was 83.2% in the males and 71.2% in the females. The most common neoplasms were leukemia (males: 24.3%, females: 24.0%), pituitary adenoma (males: 16.0%, females: 45.2%), pheochromocytoma (males: 14.7%, females: 7.3%), testicular interstitial cell tumor (males: 79.1%), and uterine endometrial stromal polyp(females: 16.4%). The incidence of other tumors of almost all the organs and/or tissues was low. Non-neoplastic lesions generally increased with advancing age of the animals.

Age Factors↗
PubMed1987

Lysozyme activity of cystic mucosal and submucosal glands in the stomal area of the gastric remnant.

In order to study the lysozyme activity in the cystic mucosal and submucosal glands in the stomal area of the gastric remnant, which is one of the components of gastritis cystica polyposa, we carried out a pathological and immunohistochemical examination of 55 patients with gastric remnants, including 19 with stomal carcinoma, after partial gastrectomy for benign gastro-duodenal diseases. These stomach specimens were examined immunohistochemically for lysozyme. The cytoplasm of some epithelial cells of cystic mucosal and submucosal glands, which showed characteristic changes in the gastro-intestinal stoma as well as background changes in the stomal carcinoma, showed a strongly positive reaction for lysozyme. These strongly lysozyme-positive cells in the cystic mucosal glands appeared more frequently in the cases of stomal carcinoma than in the non-cancerous controls.

Aged↗
PubMed1987

Induction of colorectal tumors in rats by sulfated polysaccharides.

Some sulfated polysaccharides, such as d-CGN, APS, and DSS, have carcinogenicity to the rat colorectum. These materials first induced colitis, secondly squamous metaplasia, and finally tumors at the colorectum. Initially, colitis was located in the columnar epithelium of the rectum and extended proximally thereafter. Squamous metaplasia persisted in almost all experimental rats and progressed irreversibly. The tumors were adenoma, adenocarcinoma, squamous cell papilloma, and squamous cell carcinoma. Macrophages containing these materials were observed in the lamina propria mucosa and submucosa of the colorectum. There were differences in the molecular weight of the substances and their tumor incidences. However, with regard to their carcinogenicity, these sulfated polysaccharides were inferred to be similar to each other in their target organs and process of tumor development. Consequently, these sulfated polysaccharides may be one entity of carcinogenic sulfates.

Amylopectin↗
PubMed1986

Circadian, sleep and brain temperature rhythms in cats under sustained daily light-dark cycles and constant darkness.

In adult cats, sleep-wake states and brain temperatures were determined under experimental LD cycles and prolonged DD. Convincing rhythms had not previously been well-established for this animal. The present results demonstrated daily fluctuation in total sleep time (TST) and in brain temperature (Tb). These comprise predominantly nocturnal wakefulness and high temperatures but include a bi-modal component marking dawn and dusk peaks. In addition there are ultradian variations with a period of 2-4 hour superimposed on the circadian rhythm. The latter continued at the beginning of prolonged DD, but gradually diminished and disappeared after about ten days. The TST circadian rhythm diminished more quickly than the Tb rhythm. This result suggests that the former is coupled more strongly to the circadian oscillator than the latter, and that the brain temperature rhythm could not depend on the circadian rhythm of sleep-wakefulness. These results encourage use of cats in further chronobiological studies of sleep and other physiological rhythms.

Activity Cycles↗
PubMed1986

A light and electron microscopic study of the regenerative epithelium in the intrahepatic bile duct. Experimental study of local direct instillation of paraquat into the intrahepatic bile ducts of rats.

To date, no reliable report on the regeneration of the intrahepatic bile duct epithelium following damage to the duct has been published. In this study, a direct instillation of paraquat dichloride into the intrahepatic bile ducts of rats was carried out, and the livers were examined under light and electron microscopy. One hour after treatment, the biliary epithelia showed degeneration and necrosis, and these changes remained for a considerable period in a large majority of the ducts examined. Three weeks after instillation, low columnar epithelium consisting of hyperchromatic nuclei and eosinophilic cytoplasm was present in a medium-sized bile duct, which was collared by marked periductal fibrosis. Electron microscopically, the eosinophilic epithelium showed a marked increase in the number of rough endoplasmic reticula, ribosomes, mitochondria, and filamentous structures, suggesting an active viability of the cell. Subsequently, the eosinophilic cells were replaced by normal-appearing epithelium, not associated with the periductal fibrosis. The data suggest that an epithelial regeneration occurred in the intrahepatic duct following injury and that this activity may be similar to that of the extrahepatic bile duct epithelium.

Animals↗
PubMed1985

Induction of colorectal adenocarcinoma in rats by amylopectin sulfate.

The carcinogenicity of orally administered amylopectin sulfate was studied in F344 rats. Amylopectin sulfate induced adenomas and adenocarcinomas in the rat colorectum. The incidences of tumor induction in groups that were given a 5% diet of amylopectin sulfate for 3, 6 and 9 months were 2 out of 20 rats (10%), 9 out of 20 rats (45%) and 12 out of 20 rats (60%), respectively. Squamous metaplasia of the colorectum persisted in all rats and progressed irreversibly. Amylopectin sulfate was deposited in the colorectal lamina propria, submucosa and regional lymph nodes. Amylopectin sulfate induced a lesion similar to that produced by degraded carrageenan in the rat colorectum.

Adenocarcinoma↗
PubMed1985

[Clinicopathological study of early gastric carcinoma of the cardiac portion].

Even nowadays, early gastric carcinoma of the cardiac portion still presents numerous diagnostic and pathological problems. Fifteen cases of early cancer of the cardiac portion were resected in the past 16 years. In order to clarify their characteristics, we carried out a comparison between the cardiac portion and the upper 3rd portion. The results were as follows: 1) There were cases of IIc type on the gross appearance of the cardiac portion. 2) As for the histological type, here were 14 cases of the differentiated type. on the other hand, there were 40% of the undifferentiated type of the upper 3rd portion. 3) Ten cases of early carcinoma of the cardiac portion had the lesion in the cardiac zone, while most of the early cancer of the upper 3rd portion had a strong connection with the fundic cone.

Adult↗
PubMed1985

[Clinicopathological study of minute cancer of the stomach].

Nineteen patients with solitary minute carcinoma (single cases) and 16 with foci of minute cancer, found as a component of multiple early gastric carcinoma (multiple cases) were studied. The results were as follows; 1) The histological type of the single cases was the differentiated type in 95%. 2) All lesions of the multiple cases were mucosal invasive carcinoma, while 16% of the single cases (3/19) had submucosal invasive carcinoma. 3) As for the distribution of the single and multiple cases according to the surrounding mucosal atrophy, the single eases were in the pyloric gland zone, the multiple cases in the intermediate zone.

Adenocarcinoma↗
PubMed1983

Experimental study of the pathogenesis of infantile obstructive cholangiopathy and its clinical evaluation.

1,4-phenylenediisothiocyanate was given to five groups of rats of different developmental stages (97 in all), and the changes in the hepatobiliary system were compared histopathologically. Three groups of rats given the drug after birth showed dilatation of the extrahepatic bile ducts with inflammation. Two groups given the drug during the fetal period or added after birth showed stenotic or atretic extrahepatic bile ducts due to thickening and fibrosis of the wall. This experimental model suggests that differences in the pathologic features of infantile obstructive cholangiopathy (biliary atresia, neonatal hepatitis, and bile duct dilatation) may be the result of various developmental stages in the pathogenic process. After the experiment, 11 cases of correctable type biliary atresia were compared to 24 cases of noncorrectable type in various aspects. It is suggested that the correctable type may have suffered pathogenic process later in the developmental stages than noncorrectable type.

Animals↗