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Biomedical subjects

H Yoshimura

Publications and source records attributed to H Yoshimura.

At least 397 records · Page 22Linked to original sources
PubMed1988

Brain microsomal oxidation of delta 8- and delta 9-tetrahydrocannabinol.

Brain microsomes of mice, rats, guinea pigs and rabbits catalyzed the oxidation of delta 8- and delta 9-tetrahydrocannabinol to their monohydroxylated metabolites. The most prominent metabolite was the 4'-hydroxylated metabolite on the pentyl side chain of the cannabinoids in all species tested, except that the 5'-hydroxylation of delta 9-tetrahydrocannabinol was most abundant in the guinea pig. These results are quite different from the metabolic profile of the cannabinoids with hepatic microsomes.

Animals↗
PubMed1988

Oxygenation mechanism in the oxidation of xenobiotic aldehyde to carboxylic acid by mouse hepatic microsomes.

11-Oxo-delta 8-tetrahydrocannabinol was oxidized to delta 8-tetrahydrocannabinol-11-oic acid by mouse hepatic microsomes. The oxygenation mechanism in the reaction was confirmed by the incorporation of oxygen-18 from molecular oxygen into delta 8-tetrahydrocannabinol-11-oic acid. The oxygenation of aldehyde to carboxylic acid represents a novel mechanism in biological oxidation of aldehyde to carboxylic acid.

Aldehydes↗
PubMed1988

Acute and chronic effects of ginseng saponins on maternal aggression in mice.

The present study investigated the acute and chronic effects of crude ginseng saponin (CGS), pure ginsenoside Rb1 (GS-Rb1) and ginsenoside Rg1 (GS-Rg1) on maternal aggression in mice. Maternal aggression was determined on postpartum days 5 and 7 in female mice that had been housed alone since the end of the 4-day mating period. Acute intraperitoneal administration of CGS (50 and 100 mg/kg) and GS-Rb1 (2.5 and 5 mg/kg) significantly suppressed maternal aggression in a dose-dependent manner, whereas GS-Rg1 was ineffective. As compared with the vehicle-treated group, chronic treatment with CGS (50 mg/kg) and GS-Rb1 (2.5 mg/kg) significantly suppressed maternal aggression without causing motor dysfunction, whereas GS-Rg1 (2.5 mg/kg) showed a tendency to facilitate maternal aggression. These findings indicate that the root of Panax ginseng contains a psychoactive ingredient, GS-Rb1, which can suppress maternal aggression.

Aggression↗
PubMed1988

[Characterization of thyroglobulin and thyroid peroxidase activity in patients with functioning thyroid benign tumors].

The content and chemical and immunological properties of thyroglobulin (Tg) and the activity of thyroid peroxidase (TPO) were studied in nodular and extranodular (periphery) thyroid tissue from patients with functioning thyroid tumors (hot nodules). From the present observations, the tumor extracts contained fairly large amounts of Tg, similar to that in the periphery tissue, while the content of Tg was markedly decreased in non-functioning thyroid tumors (cold nodules). The iodine content of Tg was significantly higher in nodular tissue compared with periphery tissue. These observations were in contrast to the results seen in the cold nodules in which hormone synthesis was defective. On the nature of carbohydrate moiety as compared with normal tissue, oligosaccharides of Tg from the periphery tissues changed in a manner similar to that of tumor oligosaccharides. That is, high-mannose type oligosaccharides were markedly decreased whereas multiantennary and unidentified oligosaccharides were increased. These observations were similar to those of non-functioning tumors. The content of sialic acid decreased markedly both in the tumor and periphery tissues. Immunologically, Tg preparations of the tumor and periphery tissue did not show the same affinity to the antibodies, depending on the content of iodine. Therefore, it seems that the contribution of the iodine content and iodo-amino acid has little or no significance in the heterogeneous nature of Tg-immunogenecity. Benign tumors and the periphery tissue were subjected to assay for thyroid peroxidase activity by the method employing guaiacol as the second substrate. The specific activities of the tumors were generally higher than those of periphery tissues, both in functioning and non-functioning benign tumors. In non-functioning carcinoma, on the other hand, TPO activities were lower in tumor portions than in periphery portions. This indicates that non-functioning thyroid carcinomas have a different characteristic.

Adenoma↗
PubMed1988

Psychotropic effects of ginseng saponins on agonistic behavior between resident and intruder mice.

The psychotropic actions of crude ginseng saponins, pure ginsenoside Rb1 (GS-Rb1) and ginsenoside Rg1 (GS-Rg1) obtained from the root of Panax ginseng, were evaluated from their effects on agonistic behavior in mice. A resident-intruder test situation was used. When the resident mouse was treated with crude ginseng saponins (25, 50 and 100 mg/kg i.p.), aggressive episodes (offensive sideways posture and attack bite) were significantly suppressed in a dose-dependent manner. However, the agonistic behavior was not altered when the intruder was treated with crude ginseng saponins. GS-Rb1 (2.5, 5 ad 10 mg/kg i.p.) also significantly suppressed aggressive episodes when given to the resident, whereas GS-Rg1 (2.5, 5 and 10 mg/kg i.p.) was ineffective. Neither GS-Rb1 nor GS-Rg1 given to the intruder caused any significant changes in the behavior of the resident. Although the highest dose of crude ginseng saponins suppressed locomotion frequency, it appears that both crude ginseng saponins and GS-Rb1 possess a specific psychotropic action on agonistic behavior.

Aggression↗
PubMed1988

Induction of antigen-specific IgA-forming cells in the middle ear mucosa.

Antigen-specific IgA-forming cells were induced in the middle ear mucosa by the use of soluble and particulate forms of dinitrophenylated ovalbumin. Hartley guinea pigs were locally immunized in the duodenum (group A) and trachea (group B) with the particulate form of dinitrophenylated ovalbumin one week after systemic priming with the soluble form. Otitis media was then induced with the intratympanic inoculation of the antigen. The control animals (group C) received only intratympanic inoculation after systemic priming. The mean titers of salivary IgA antibody of groups A and B were significantly greater than that of group C, and the mean value of serum IgG antibody titers of group C was significantly greater than those of groups A and B. The occurrences of otitis media in groups A and B were significantly suppressed, and histologic changes of the middle ear mucosa of groups A and B were slighter than those of group C. Antigen-specific IgA-forming cells were detected in the inflamed middle ear mucosa from group A and B animals, while these cells could not be found in group C animals. These results demonstrate the immunization strategy whereby the mucosal IgA immunity of the middle ear cavity can be effectively induced and enhanced to prevent otitis media.

Animals↗
PubMed1988

An attempt of immunodiagnosis by means of mixed passive hemagglutination (MPHA) test for human pulmonary dirofilariasis.

The mixed passive hemagglutination (MPHA) test was used for the first time in an attempt to diagnose human pulmonary dirofilariasis in a comparison with the results of ELISA. Eight of nine patients tested with the MPHA test were positive and one was false-positive; these results coincided exactly with those of ELISA. Qualitative agreement between the MPHA test and ELISA was 90.4% of 374 human sera. The present study indicates that the MPHA test seems to be a promising diagnostic tool for human pulmonary dirofilariasis.

Adult↗
PubMed1988

Computed tomography detection of small daughter nodules in hepatocellular carcinoma after iodized oil infusion into the hepatic artery.

The detectability of small daughter nodules of hepatocellular carcinoma by computed tomography after hepatic arterial infusion of Lipiodol (iodized oil) and by infusion hepatic angiography was studied in 102 cases. The Lipiodol was selectively accumulated by the tumor. Tumors and small daughter nodules appeared as high-density areas on computed tomography. In 24 cases daughter nodules were identified only by computed tomography. In 50 cases computed tomography demonstrated superior ability to detect the daughter nodules when compared with infusion hepatic angiography. In 21 cases the daughter nodules were detected for the first time in areas other than the main site of the primary tumor. Lipiodol-computed tomography is very effective in the diagnosis of daughter nodules of hepatocellular carcinoma.

Angiography↗
PubMed1988

Electroporation of cell membrane visualized under a pulsed-laser fluorescence microscope.

Controlled permeability can be conferred to cell membranes by exposing cells to a microsecond electric pulse of sufficient intensity (electroporation). By constructing a fluorescence microimaging system with a submicrosecond time resolution we have been able to resolve temporally and spatially the events in a single cell under a microsecond electric pulse. An enormous membrane conductance, corresponding to a loss of 0.01-0.1% of the membrane area, was observed in those membrane regions where the transmembrane potential induced by the electric pulse exceeded a critical value. The conductance decreased to a low level in a submillisecond after the pulse, leaving a moderately electroporated cell.

Animals↗
PubMed1988

Purification and characterization of two forms of chicken liver cytochrome P-450 induced by 3,4,5,3',4'-pentachlorobiphenyl.

3,4,5,3',4'-Pentachlorobiphenyl (PenCB), one of the most potent 3-methylcholanthrene (MC)-type inducers of hepatic enzymes in animals, caused a remarkable induction of liver microsomal monooxygenases, particularly 7-ethoxyresorufin (7-ER) O-deethylase, benzo(a)pyrene (BP) 3-hydroxylase, and testosterone 16 alpha-hydroxylase in chickens, but not NADPH-cytochrome c(P-450) reductase and cytochrome b5. Two forms of cytochrome P-450 (P-450) in liver microsomes of PenCB-treated chickens were purified and characterized. The absorption maxima of the CO-reduced difference spectra of both enzymes (chicken P-448 L and chicken P-448 H) were at 448 nm. From the oxidized form of their absolute spectra, chicken P-448 L was a low-spin form and chicken P-448 H was a high-spin form. They had molecular masses of 56 and 54 kDa, respectively. In a reconstituted system, 7-ER O-deethylation, BP 3-hydroxylation, and testosterone 16 alpha-hydroxylation were catalyzed at high rates by chicken P-448 L but not by chicken P-448 H. Chicken P-448 L also catalyzed N-demethylation of aminopyrine, benzphetamine, and ethylmorphine with relatively low activity. On the other hand, chicken P-448 H functioned only in catalyzing estradiol 2-hydroxylation. These results were supported by an inhibition study of microsomal monooxygenases using an antibody against each enzyme. Immunochemical studies revealed that the enzymes differ from each other but are both inducible by PenCB-treatment. Chicken P-448 L and chicken P-448 H respectively comprise about 82 and 7% of the total P-450 content in chicken liver microsomes.

Animals↗
PubMed1988

Enhanced thyroid iodine metabolism in patients with triiodothyronine-predominant Graves' disease.

Some patients with hyperthyroid Graves' disease have increased serum T3 and normal or even low serum T4 levels during treatment with antithyroid drugs. These patients with elevated serum T3 to T4 ratios rarely have a remission of their hyperthyroidism. The aim of this study was to investigate thyroid iodine metabolism in such patients, whom we termed T3-predominant Graves' disease. Mean thyroid radioactive iodine uptake was 51.0 +/- 18.1% ( +/- SD) at 3 h, and it decreased to 38.9 +/- 20.1% at 24 h in 31 patients with T3-predominant Graves' disease during treatment. It was 20.0 +/- 11.4% at 3 h and increased to 31.9 +/- 16.0% at 24 h in 17 other patients with hyperthyroid Graves' disease who had normal serum T3 and T4 levels and a normal serum T3 to T4 ratio during treatment (control Graves' disease). The activity of serum TSH receptor antibodies was significantly higher in the patients with T3-predominant Graves' disease than in control Graves' disease patients (60.5 +/- 19.2% vs. 20.4 +/- 18.2%; P less than 0.001). From in vitro studies of thyroid tissue obtained at surgery, both thyroglobulin content and iodine content in thyroglobulin were significantly lower in patients with T3-predominant Graves' disease than in the control Graves' disease patients. Thyroid peroxidase (TPO) activity determined by a guaiacol assay was 0.411 +/- 0.212 g.u./mg protein in the T3-predominant Graves' disease patients, significantly higher than that in the control Graves' disease patients (0.129 +/- 0.112 g.u./mg protein; P less than 0.01). Serum TPO autoantibody levels determined by immunoprecipitation also were greater in T3-predominant Graves' disease patients than in control Graves' disease patients (52.6 +/- 27.7% vs. 32.4 +/- 11.4%; P less than 0.05). Binding of this antibody to TPO slightly inhibited the enzyme activity of TPO, but this effect of the antibody was similar in the two groups of patients. The data suggest enhanced iodine metabolism in the thyroid gland of patients with T3-predominant Graves' disease, which may relate to the discordant T3 overproduction in patients with this type of Graves' disease.

Adolescent↗
PubMed1988

Identification of cannabielsoin, a new metabolite of cannabidiol formed by guinea-pig hepatic microsomal enzymes, and its pharmacological activity in mice.

Metabolism of cannabidiol (CBD), one of the major components of marihuana, was studied in the guinea pig both in vitro and in vivo. Analyses of metabolites by gas chromatography and gas chromatography-mass spectrometry proved that cannabielsoin (CBE) was formed from CBD as a novel metabolite, and that the amount was about one-sixth of 7-hydroxy-CBD, which was the most abundant metabolite under in vitro conditions in the presence of microsomal monooxygenase (cytochrome P-450). CBE was also found in the liver of the guinea pig that was given CBD (100 mg/kg) intraperitoneally 1 h before sacrifice. The effects of CBE on pentobarbital-induced sleep and body temperature were assessed in the mouse; CBE possessed little activity in either case.

Animals↗