Search PubMed⌕ Search

Biomedical subjects

Y Harada

Publications and source records attributed to Y Harada.

At least 667 records · Page 37Linked to original sources
PubMed1986

Inner ear damage induced by Mycobacterium fortuitum.

We used electron microscopy to investigate Mycobacterium fortuitum-induced changes in the inner ears of mice. We found that the inner and outer hair cells had degenerated and disappeared in the organ of Corti. Changes in the lower turn of the cochlea were more severe than those of the upper turn while the changes of the outer hair cells were more severe than those of the inner hair cells. Disappearance, fusion and ballooning of the sensory hairs were observed in the vestibular organs. The bacterial extract also induced inner ear damage which was similar to that caused by live M. fortuitum.

Animals↗
PubMed1986

An experimental study on the isolated lateral semicircular canal of the bull frog.

We used isolated lateral semicircular canals from the bull frog, Rana catesbeiana. The cupula was removed from the crista and a glass micropipette was used to depress the sensory cilia on the crista toward the utricular side. Five points on the crista were selected for stimulation. Decremental time constants of the lateral ampullary nerve action potentials were measured. The longest time constant was obtained from stimulation to the wide portion of the crista. The time constant progressively decreased as the narrow side of the crista was approached. These results indicate that the lateral semicircular canal crista is equivalent to the halved posterior semicircular canal crista in terms of both morphology and physiology.

Action Potentials↗
PubMed1986

Release of endogenous prostaglandins by mild hyperosmotic saline inhibits tetragastrin-stimulated gastric acid secretion in rats.

Filling of the gastric lumen of rats with 1.0 M NaCl solution (5 ml) for 10 min under urethane anesthesia caused an increase in the gastric fluid concentrations of prostaglandin (PG) E2, 13,14-dihydro-15-keto-PGE2 and 6-keto-PGF1 alpha as determined by radioimmunoassay. PGE2 was the major PG generated. The levels of PGE2 in the gastric fluid were increased dose-dependently after filling the lumen with 0.3, 0.5, 0.7 or 1.0 M NaCl solutions. The pH of the gastric fluid increased similarly after 0.5 to 1.0 M NaCl solutions. Indomethacin (10 mg/kg, i.p.) suppressed the PGE2 increase caused by 1.0 M NaCl solution, but did not prevent the increase of the pH of the gastric fluid induced by intragastric 1.0 M NaCl. Infusion of tetragastrin (62.5 micrograms/kg/hr, i.v., for 10 min) caused a marked increase of acid secretion without modifying intragastric concentration of PGE2. The acid secretion due to tetragastrin was completely inhibited after intragastric administration of 1.0 M NaCl solution, while indomethacin restored the tetragastrin-induced acid secretion, with prevention of a rise of intragastric PGE2 levels. These observations suggest that 1.0 M NaCl solutions suppress basal intragastric acid through a mechanism which is independent of prostaglandins. In contrast, the suppression of tetragastrin-induced acid secretion by intragastric 1.0 M NaCl solution appears to be mediated through a release of prostaglandins.

6-Ketoprostaglandin F1 alpha↗
PubMed1986

Gastric mucus glycoprotein in different rat strains.

The extent of gastric damage induced by aspirin was found to differ according to rat strain. The occurrence of ulcers varied, from high to low, in the following strain order: Donryu, Sprague-Dawley (SD) and Wistar. The content of corpus mucus glycoprotein was essentially the same in all the strains: about 6 mg as hexose of dry tissue. Antral mucus glycoprotein content increased in the order Wistar, SD and Donryu: 7.1, 8.3 and 9.1 mg, respectively. Gastric mucus glycoprotein carbohydrate composition was essentially the same in all three strains. The relatively low proportions of N-acetylglucosamine, galactose and sialic acid from the antrum was a characteristic feature in contrast to mucus glycoprotein from the corpus which contained a high proportion of these sugars.

Animals↗
PubMed1986

Development of the crista ampullaris in the mouse.

The process of development of the crista ampullaris has been investigated in the mouse using SEM. Cristae ampullaris of the CBA/CBA mice, from the 13.5th gestational day to the day 2 weeks by were studied. On the 13.5th gestational day, there were numerous microvilli and a primary cilium on the crista ampullaris. Sensory hairs first appeared on the 14.5th gestational day. The kinocilium and stereocilia were short and the length of the stereocilia was almost constant. The formation of the cupula, which had fine network-like structures, started on the 14.5th gestational day.

Animals↗
PubMed1986

Neurilemmoma of the larynx: (a case report).

The authors have treated a 61-year-old woman with neurilemmoma of the larynx. The tumour was located in the submucosal region of the arytenoid on the right side of the larynx. Surgical resection of the tumour had to be done by external neck excision instead of endoscopically.

Female↗
PubMed1986

Effect of ingested winged bean lectin on gastrointestinal function in the rat.

The present study was undertaken to provide further evidence for mechanisms proposed for the toxicity of ingested winged bean lectin in animals: to determine its effect on activities of some hydrolases localized in the brush border membrane of the small intestine. An adaptive increase in sucrase activity of rats given a high-sucrose diet (HSD) was restrained by the addition to HSD of a lectin fraction (WBLF) isolated from raw winged beans but not by that of heated WBLF or soybean trypsin inhibitor. Restraining effects of WBLF added to HSD on time-course changes in activities of sucrase, alkaline phosphatase and leucine aminopeptidase of rats after giving HSD were similar to those of concanavalin A, which had been observed in the previous study. These results substantiate that the mechanism of the toxicity of ingested winged bean lectin involves its binding to the luminal surface of the small intestine and in turn disturbing the functional formation of the brush border membrane.

Alkaline Phosphatase↗
PubMed1986

[Experimental study of the ototoxicity of fosfomycin].

Two tenths ml of 5% fosfomycin sodium solution (10 mg) was injected into the tympanic cavity of guinea pigs once a day for 7 days. Auditory brain stem response (ABR) was performed to examine the effect of the drug on the experimental animals. Additionally, a scanning electron microscopic study was also performed to observe the effect of the drug on outer hair cells of the organ of Corti and on vestibular sensory epithelia. No degenerative changes were observed in outer hair cell cilia of the organ of Corti and the vestibular sensory cilia at 1 day, 7 days, 14 days and 1 month after injection. No changes of the threshold of ABR were also noticed.

Animals↗
PubMed1986

Scanning electron microscopic observation of the crista ampullaris.

The crista ampullaris of the guinea pig and the bull frog were investigated by scanning electron microscopy. The crista ampullaris were freeze fractured or sheared followed by maceration with 0.1% OsO4 solution. Following this, three-dimensional intracellular structures were observed. The mitochondria of the sensory cells varied in shape from globular to long and slender. Golgi apparatus and endoplasmic reticulum of the sensory cells were also demonstrated clearly. Nerve elements, nerve endings and synaptic structures were also observed stereoscopically.

Animals↗