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Biomedical subjects

H Yoshimura

Publications and source records attributed to H Yoshimura.

At least 451 records · Page 25Linked to original sources
PubMed1986

Plasmacytoma of the thyroid gland.

Primary plasmacytoma of the thyroid gland is a rare disease, and clinicopathologic features of this disease are not fully understood. Six cases of primary plasmacytoma of the thyroid, in which immunoperoxidase procedures confirmed a monoclonal nature of proliferating plasma cells are presented. All patients had antithyroid antibodies in their serum together with histologic evidence of chronic lymphocytic thyroiditis, suggesting an intimate relationship of these diseases. Review of the literature revealed that 18 cases, 14 cases from Western countries and 4 cases from Japan, described primary thyroid plasmacytoma. The authors summarized the clinicopathologic features in the current and previously reported cases.

Adult↗
PubMed1986

Radiation therapy for nasopharyngeal carcinoma. Retrospective review of 105 patients based on a survey of Kansai Cancer Therapist Group.

One hundred five patients with nasopharyngeal carcinoma were treated with radiation therapy combined with or without chemotherapy at 16 of the participating institutes in Kansai Cancer Therapist Group, Japan, from January 1978 to December 1980. The study comprised 77 males and 28 females; their ages ranged from 15 to 80 years (mean, 53 years). Five-year survival rates according to stage were as follows: Stage I, 100%; Stage II, 67%; Stage III, 44%; and Stage IV, 34%. As far as Stage IV disease was concerned, the radiation therapy only group showed significantly poorer prognosis than the combined radiation and chemotherapy group (P less than 0.05). Concerning the N stage and treatment method, the radiation therapy only group showed a higher metastatic rate than the chemotherapy combined group (35% versus 14%, P less than 0.05).

Adolescent↗
PubMed1986

Effect of repeated administration of 11-hydroxy-delta 8-tetrahydrocannabinol, an active metabolite of delta 8-tetrahydrocannabinol, on the hepatic microsomal drug-metabolizing enzyme system of mice.

The effects of delta 8-tetrahydrocannabinol (delta 8-THC) and its major and active metabolite, 11-hydroxy-delta 8-tetrahydrocannabinol (11-OH-delta 8-THC), on the hepatic microsomal drug-metabolizing enzyme system were studied in mice. The repeated administration of 11-OH-delta 8-THC (5 mg/kg/day, i.v.) for 3 or 7 days increased significantly the activities of aniline hydroxylase and p-nitroanisole O-demethylase. By the same treatment, cytochrome P-450 content (3 days) or NADPH-cytochrome c reductase activity (7 days) was also increased significantly. The treatment with delta 8-THC for 7 days (5 mg/kg/day, i.v.) significantly increased aniline hydroxylase only. 11-OH-delta 8-THC increased the Vmax, but not the Km, values for both drug-metabolizing enzymes, whereas delta 8-THC decreases significantly the Km value (270 microM) for p-nitroanisole O-demethylase as compared with the control (398 microM). Repeated administration of these cannabinoids for 7 days also increased the metabolism of delta 8-THC by hepatic microsomes; this was attributed to an enhanced formation of 11-OH-delta 8-THC. In contrast, microsomal formation of 7 alpha-OH-delta 8-THC was decreased significantly by treatment with delta 8-THC. 11-OH-delta 8-THC, but not delta 8-THC, treatment increased the metabolism of 11-OH-delta 8-THC by hepatic microsomes. These findings indicate that delta 8-THC and 11-OH-delta 8-THC treatment can induce hepatic microsomal drug-metabolizing enzymes and affect differently the catalytic properties of the enzymes.

Aniline Hydroxylase↗
PubMed1986

Intermediate lymphocytic lymphoma of the thyroid. An immunologic and immunohistologic study.

Four cases of thyroid lymphomas are presented showing curious histologic difficult to distinguish from severe lymphocytic thyroiditis by routine histologic study alone. The age of the patients ranged from 39 to 63 years. Three female patients suffered from autoimmune (lymphocytic) thyroiditis for 2 to 20 years until the present illness. A male patient had no history of thyroiditis. Rapid growth of struma in these patients suggested an evolution of malignant lymphomas. Histologic study results showed that small atypical lymphoid cells with slightly irregular and indented nuclear contour surrounded randomly distributed secondary follicles as a wide mantle. Immunohistologic staining showed that these atypical small lymphoid cells expressed surface properties intermediate between mantle-zone lymphocytes and germinal center cells with a restricted expression of kappa chain in three cases. Stages of tumors were stage I in three cases and stage II in one case. The findings demonstrated were intermediate lymphocytic lymphomas of the thyroid.

Antibodies, Monoclonal↗
PubMed1986

Role of adrenergic alpha-receptors in regulation of acetylcholine release evoked by distension of guinea pig ileum.

The significance of adrenergic nerves in the regulation of acetylcholine (ACh) release evoked by distension of the guinea pig ileum was evaluated by pharmacological manipulations. ACh release was measured by bioassay. Release in response to distension was completely abolished by epinephrine and norepinephrine. Tyramine also suppressed the distension-evoked ACh release, while dopamine was ineffective. The release of ACh in the anal segment, adjacent to the distended part, was abolished by epinephrine and norepinephrine. Dibenamine and phentolamine abolished ACh release anal to the distension, but augmented release orally, while dichloroisoproterenol and propranolol were ineffective. The present results give direct evidence that adrenergic nerves modulate cholinergic transmission in the myenteric plexus through alpha-receptors.

Acetylcholine↗
PubMed1986

Embryolethality of bromofenofos in rats.

Bromofenofos, an organophosphorus anthelmintic, was suspended in deionized water and administered once daily to pregnant rats by gastric intubation on days 8 through 15 of pregnancy in doses of 0, 2.5, 5, 10 and 20 mg/kg. The dams were killed on day 21 of pregnancy, and the number of implants, resorptions and live fetuses was counted. All fetuses were weighed and examined by routine teratological methods. As the results showed, this compound was highly embryolethal in the 20 mg/kg group; approx. 91% of the implants were resorbed at this dose level. Although none of the fetuses were externally malformed in any group, the incidence of skeletal and internal malformations was significantly increased in fetuses in the 20 mg/kg group. Skeletal malformations observed at this dose level were bipartite vertebral centra and wavy ribs. Internal malformations involved anophthalmia, hydronephrosis and hypoplasia of the uterus.

Abnormalities, Drug-Induced↗
PubMed1986

Pulmonary asbestosis: CT study of subpleural curvilinear shadow. Work in progress.

High-resolution computed tomographic scans of 19 patients with pulmonary asbestosis revealed a subpleural curvilinear shadow (SCLS) parallel to the inner chest wall in the lungs of 15 (78.9%) patients. Most (46.7%) SCLS measured greater than 5 cm but less than 10 cm in length and occurred less than 1 cm from the inner chest wall in all cases. SCLS was distributed mainly in the lower lobe in patients with mild pulmonary fibrosis and in segments where fibrosis was mild in patients with honeycomb shadows. This may reflect initiation of pulmonary fibrosis leading to the formation of a honeycomb shadow. Radiologic-pathologic correlation, achieved in one postmortem specimen, seemed to indicate that SCLS was associated with the initial change of fibrosing bronchioloalveolitis, which is characteristic of pulmonary asbestosis.

Asbestosis↗
PubMed1986

Effect of administration route on the selective lymphatic delivery of cyclosporin A by lipid-surfactant mixed micelles.

The absorption and lymphatic delivery of a new immunosuppressive drug, cyclosporin A (CsA), with the aid of lipid surfactant mixed micelles (MM) system using different administration routes were studied in the thoracic duct cannulated rat model at a dose level of 7 mg/kg. The rectal or intraperitoneal (i.p.) administration of CsA indicated a small amount of CsA in the plasma and in the lymph for 6 h. As oral routes, intrastomach (i.s.) and intraduodenal (i.d.) administration of CsA were performed and high lymph CsA levels were obtained. The i.s. administration of CsA resulted in the highest CsA levels in the lymph, 16 micrograms/ml, about twenty times higher than the rectal or i.p. administration. These results strongly support the usefulness of an oral CsA dosage form for the selective lymphatic delivery of CsA in clinical immunosuppressive therapy by means of a new mixed micelles system.

Administration, Oral↗
PubMed1986

Effects of two cannabinoids on hepatic microsomal cytochrome P-450.

The effects of cannabidiol (CBD) and delta 9-tetrahydrocannabinol (delta 9-THC) on the synthesis and degradation of hepatic microsomal cytochrome P-450 were studied in mice. Cannabinoids used (10, 50 and 100 mg/kg, i.p.) did not affect delta-aminolevulinic acid synthetase activity in the liver. delta 9-THC-treatment (10, 50 and 100 mg/kg, i.p.) markedly stimulated heme oxygenase activity in hepatic 18000 X g supernatant fractions in a dose-dependent manner, whereas CBD-treatment was without effect. In vitro experiments, CBD and delta 9-THC (40 to 160 microM) markedly inhibited nicotinamide adenine dinucleotide phosphate (NADPH)-induced lipid peroxidation in hepatic microsomes. When CBD was incubated with the hepatic microsomes in the presence of an NADPH-generating system, cytochrome P-450 content decreased significantly. However, delta 9-THC showed no effects in similar experiments. The rate of decrease in the cytochrome P-450 content using CBD (160 microM) was 0.212 nmol/mg protein/20 min in microsomes from control mice. This value increased significantly in microsomes from phenobarbital-treated mice (0.792 nmol/mg protein/20 min) but not in those from 3-methylcholanthrene-treated mice (0.190 nmol/mg protein/20 min). The metabolic rate (per nmol cytochrome P-450) of CBD was also increased significantly by phenobarbital-treatment but not by 3-methylcholanthrene-treatment. These results suggest that CBD metabolites rather than CBD itself, play some role in the decreasing effect on cytochrome P-450 content in the hepatic microsomes in vitro, and that the microsomal formation of reactive metabolite of CBD is increased by phenobarbital-treatment.

5-Aminolevulinate Synthetase↗
PubMed1986

Suppressive effect of interferon inducer, polyriboinosinic acid-polyribocytidylic acid on induction of uridine diphosphate-glucuronyltransferases and monooxygenases in liver microsomes of rats.

The effect of polyriboinosinic acid-polyribocytidylic acid [poly(I).poly(C)] on glucuronyltransferase activities toward 4-nitrophenol and 4-hydroxybiphenyl in liver microsomes of Wistar rats was examined by its single or co-administration with 3-methylcholanthrene and phenobarbital. The increased 4-nitrophenol glucuronyltransferase activity by treatment with 3-methylcholanthrene was significantly suppressed following the co-administration with poly(I).poly(C), although the activity was not affected by the treatment with poly(I).poly(C) alone. In addition, 4-hydroxybiphenyl glucuronyltransferase activity decreased or tended to decrease by the treatment with poly(I).poly(C) alone, and the activity induced by phenobarbital was strikingly decreased following the co-administration with poly(I).poly(C). This result suggested that poly(I).poly(C) comprehensively decrease the induction of glucuronyltransferases regardless of their multiple forms. Furthermore, contents of cytochromes P-450 and b5 were also decreased by the treatment with poly(I).poly(C) alone or the co-administration with the inducers. Concomitantly, arylhydrocarbon hydroxylase and benzphetamine N-demethylase activities were significantly decreased by the treatment alone or the co-administration with the inducers. These findings supported a view that the suppressive effect of poly(I).poly(C) may be derived from the prevention of de novo synthesis of the apoprotein of the enzymes and/or the increased degradation.

Animals↗