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Biomedical subjects

H Yoshimura

Publications and source records attributed to H Yoshimura.

At least 631 records · Page 35Linked to original sources
PubMed1980

Cholinergic mechanisms in scent marking behavior by Mongolian gerbils (Meriones unguiculatus).

The Mongolian gerbil reared in Japan manifested scent marking behavior in the similar behavioral topography as described by foreign researchers. The frequency of marking was affected by early isolation housing; isolated male gerbils exhibited a higher frequency of marking than aggregated males. The marking behavior was suppressed by scopolamine (1.5 mg/kg, IP), whereas methylscopolamine was ineffective. In order to elucidate the possible neural mechanisms, acetylcholinesterase (ACh-E) and choline acetyltransferase (Ch-Ac) activities were measured in 8 discrete areas of the brain (the cortex, striatum, amygdala, hypothalamus, midbrain, hippocampus, olfactory bulbs, and pons plus medulla oblongata). There was, however, no significant difference between isolated and aggregated gerbils in either ACh-E or Ch-Ac activity in any of the brain areas. These results suggest that other neural events, such as changes in the ACh turnover rate or in ACh release, may participate in the manifestation of scent marking behavior.

Acetylcholinesterase↗
PubMed1980

Pancreatic tumors induced by a single intraperitoneal injection of azaserine in partial pancreatectomized rats.

Pancreatic tumorigenesis of azaserine by a single intraperitoneal (i.p.) injection after partial pancreatectomy in male Wistar rats was studied. Pancreatic lesions developed in all rats 52 weeks after the administration of azaserine at doses of 50 mg (Group 1) or 100 mg/kg body wt (Group 2). Histologically, there were hyperplastic nodules in 4 of 12 rats and 4 of 7 rats, in Groups 1 and 2, respectively, adenomas 100% in both groups, and adenocarcinomas 2 of 7 rats of Group 2. It appears that pancreatic regeneration induced by partial pancreatectomy enhances the azaserine tumorigenesis.

4-Hydroxyaminoquinoline-1-oxide↗
PubMed1980

Carcinogenic effect of N-bis-(2-hydroxypropyl)nitrosamine in newborn rats.

The carcinogenic effect of N-bis(2-hydroxypropyl)nitrosamine (BHP) was studied in newborn Wistar rats. Tumors were induced in the lung (adenoma), pancreas (adenoma), kidney (nephroblastoma), and ovary (benign granulosa cell tumor) at 24 weeks after the treatment and in the lung (adenoma and adenocarcinoma), liver (hemangioma, hemangioendothelioma, and hepatocellular carcinoma), pancreas (adenoma), kidney (renal cell carcinoma and nephroblastoma), thyroid (adenocarcinoma) and ovary (benign and malignant granulosa cell tumors) at 52 weeks. The highest incidence of tumor was seen in the liver of rats applied BHP within 24 hours after birth. These results indicate that newborn Wistar rats are more susceptible to BHP than are adult rats.

Animals↗
PubMed1980

Drug resistance and R plasmids in Escherichia coli strains isolated from imported pet birds.

Drug resistance in Escherichia coli strains isolated from pet birds (mynahs, macaws, finches, common bengals, parrots, and flamingos) imported into Japan from 10 foreign countries in 1977 and 1978 was investigated. Of the 309 strains isolated from 127 pet birds in the Animal Quarantine Service, 232 (75.1%) were drug resistant. Furthermore, strains resistant to oxytetracycline hydrochloride, dihydrostreptomycin, and sulfadimethoxine were relatively common. Resistance patterns varied from single to sextuple resistance, and 148 (63.8%) of the resistant strains had conjugative R plasmids. These results suggest that the high incidence of drug resistance and R plasmids in E. coli strains isolated from these pet birds may be a reflection of the prophylactic use of antibiotics for the prevention of diseases which increasingly occur with importation of the birds. Furthermore, the results suggest that the birds may be potential reservoirs of drug-resistant E. coli for families who raise and have intimate contact with such birds.

Ampicillin↗
PubMed1980

Pathological study of multiple gastric carcinoma.

Multiple gastric carcinoma was investigated on 101 of 1901 resected stomachs. The frequency of multiple carcinoma was 4.7% and 6.9% of the advanced and early carcinomas, respectively. Male to female ratio was 2.9 to 1 with average age of 62.0 and that was 1.9 to 1 with average age of 57.7 in the total gastric carcinomas. The well-differentiated carcinomas with intimate relation to the intestinal metaplasia increased by aging and occupied about 70% of all lesions. The intestinal metaplasia usually showed higher grade in the cases with multiple carcinomas than those with single lesion. It should be considered that intestinal metaplasia plays the important role in the histogenesis of gastric carcinoma, especially in that of the well-differentiated one.

Adult↗
PubMed1980

Malignant transformation of adenoma in large intestine--especially on villous adenoma.

The incidence of 454 resected adenomas was histologically 87.8% of tubular, 7.7% of tubulovillous and 4.5% of villous adenomas, respectively. Eigtosigmoid region. Male to female ratio was 1 to 1.8, 1.5 to 1 and 1.8 to 1 for the villious, tubulovillous and tubular adenomas, respectively. Adenocarcinomas of large intestine consisted of 684 cases, 709 lesions and male to female ratio was 1 to 1.01. It should be considered that the adenomas in female may grow largely compared with those in male, with subsequent malignant transformation. Although the adenomas were found at the rate of 26.4% in the rectosigmoid region, 74.2% of the adenocarcinomas were found in this region, because the adenomas in this region grow largely compared with the other regions. Mucinous carcinomas were found in 33%, 23% and 9%, respectively, in the adenocarcinomas with remaining adenoma showing villous, tuvulovillous and tubular types.

Adenocarcinoma↗
PubMed1980

Motion of the interatrial septum in acute mitral regurgitation. Clinical and experimental echocardiographic studies.

The interatrial septal echocardiograms from 15 patients with acute mitral regurgitation due to ruptured chordae tendineae were compared with those from 14 normal subjects. On the cross-sectional echocardiogram, the interatrial septal configuration in patients with chordal rupture showed a characteristic pattern in which the interatrial septum (IAS) was flat or slightly convex toward the left atrium at end-diastole and became markedly convex toward the right atrium at end-systole. On the M-mode echocardiogram, the interatrial septal amplitude was greater in patients with chordal rupture (12.4 +/- 1.9 mm) than in normal subjects (9.4 +/- 0.9 mm). Systolic fluttering of the IAS was found in five of 10 patients with rupture of the chordae attached to the posterior mitral leaflet. This finding was thought to be specific for acute mitral regurgitation due to ruptured chordae to the posterior mitral leaflet. After operation, the amplitude of the IAS became normal or diminished and systolic fluttering of the IAS disappeared. Animal experiments performed to clarify the mechanism of these findings showed that increased systolic motion of the IAS resulted from an increased in the systolic left atrial-to-right atrial pressure gradient due to acute mitral regurgitation. The systolic fluttering of the IAS was thought to represent a jet stream against the IAS due to rupture of the chordae tendineae to the lateral half of the posterior mitral leaflet. We conclude that the interatrial septal echocardiogram reflects the hemodynamic changes due to acute mitral regurgitation and direction of the regurgitant jet against the IAS. This finding may prove to be important in diagnosing acute mitral regurgitation secondary to ruptured chordae tendineae.

Acute Disease↗
PubMed1980

Metabolism in vitro of sulindac. Sulfoxide-reducing enzyme systems in guinea pig liver.

The sulfoxide reduction of sulindac (cis-5-fluoro-2-methyl-1-[p-(methylsulfinyl)-benzylidenyl]indene-3-acetic acid), an anti-inflammatory agent, was demonstrated in vitro by cell-free preparations of guinea pig liver. The sulfoxide reductase activity was located in both fractions of microsomes and 105000X g supernatant. The microsomal reductase was NADPH- or NADH-dependent, and required the factor present in the soluble fraction for its activity. The factor was heat-labile and non-dialyzable. Furthermore, a partial purification of the microsomal NADPH-cytochrome c reductase resulted in a paralleled increase of the sulfoxide reductase activity. The present observations suggest that the soluble factor described above functions as an electron transfer component coupled with NADPH-cytochrome c reductase.

Animals↗
PubMed1980

Studies on enzymic cis-trans isomerization of nitrothiophene and nitrobenzene derivatives.

The enzymic cis-trans isomerization of nitrothiophene and nitrobenzene derivatives was comparatively investigated by using the geometrical isomers of 3-(5-nitro-2-thienyl)-2-(2-furyl)acrylamide and 3-(4-nitrophenyl)-2-(2-furyl)-acrylamide. As a result, the nitrothiophene derivative was mainly isomerized from the cis to the trans form by milk xanthine oxidase or rat liver microsomes supplemented with an electron donor. In the case of the nitrobenzene derivative, however, such enzymic cis-trans isomerization was not observed in these enzyme systems.

Animals↗
PubMed1980

UDP-glucuronyltransferase activities of rabbit liver microsomes for cannabinoids.

UDP-glucuronyltransferase activities for delta 8-tetrahydrocannabinol, 11-hydroxy-delta 8-tetrahydrocannabinol, cannabidiol and cannabinol were examined using liver microsomes of rabbits. The activities for cannabidiol and cannabinol were 2.5 and 19 times higher, respectively, than those for delta 8-tetrahydrocannabinol and 11-hydroxy-delta 8-tetrahydrocannabinol. Thus, the present study supports the view that glucuronide formation plays an important role in the metabolism of cannabinol, but does only a minor role in that of delta 8-tetrahydrocannabinol and 11-hydroxy-delta 8-tetrahydrocannabinol.

Animals↗
PubMed1980

Identification and determination of 11-oxo-delta8-tetrahydrocannabinol as an intermediate metabolite of delta8-tetrahydrocannabinol in the mouse brain and liver.

11-Oxo-delta 8-tetrahydrocannabinol (11-oxo-delta THC) was found in the mouse brain and liver extracts as a new in vivo metabolite of delta8-THC. The metabolite was detected by thin-layer chromatography using two aldehyde reagents together with a phenol reagent and identified as a heptafluorobutyrate by ECD-gas chromatography. This identification was further supported by gas chromatography-mass spectrometry. Content of the metabolite in the mouse liver was 0.09 or 0.19 microgram/g at 15 min after the i.v. injection of delta8-THC or 11-hydroxy-delta8-THC (11-OH-delta8-THC) at a dose of 10 mg/kg. On the contrary, 11-oxo-delta 8-THC was not precisely quantified (less than 0.01 microgram/g) in the brain after injection of delta 8-THC, although its content after the injection of 11-OH-delta 8 THC was 0.03 microgram/g.

Animals↗
PubMed1980

Studies of metabolic fate of a new antiallergic agent, azelastine (4-(p-chlorobenzyl)-2-[N-methylperhydroazepinyl-(4)]-1-(2H)-phthalazinone hydrochloride).

The metabolic fate of a new antiallergic agent, azelastine (4-(p-chlorobenzyl)-2-[N-methylperhydroazepinyl-(4)]-1-(2H)-phthalazinone hydrochloride) in rats and guinea pigs was investigated using its 14C-labelled compound. The blood level of radioactivity reached the maximum at 1-1.5 hr after oral administration, indicating the rapid absorption of the drug from gastrointestinal tract. A high concentration of radioactivity was detected in the lung of both species following either oral or intravenous administration. The major pathway of excretion of radioactivity was by way into feces, in both species. The radioactivity excreted in feces was attributable to that which was excreted in bile and exsorbed into gastrointegtinal tract. When the drug was given to pregnant rats, the concentration of radioactivity in the fetus was significantly lower than those in placenta and uterus, indicating the limited placental transfer of the drug. The successive oral administration of the drug in lower doses exerted no effect on the activity of microsomal drug-metabolizing enzymes of rat liver, while in higher doses, had a slight effect.

Administration, Oral↗