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Biomedical subjects

T Motoyama

Publications and source records attributed to T Motoyama.

At least 91 records · Page 5Linked to original sources
PubMed1996

Deficiency in nitric oxide bioactivity in epicardial coronary arteries of cigarette smokers.

OBJECTIVES: This study sought to examine nitric oxide-mediated regulation of epicardial coronary arterial tone in cigarette smokers. BACKGROUND: Cigarette smoking is a major risk factor for coronary artery disease and is highly prevalent in patients with coronary spastic angina. Long-term exposure to cigarette smoking has been recently reported to suppress endothelium-dependent arterial relaxation in vivo humans. METHODS: Responses of epicardial coronary artery diameter to single or combined infusion of acetylcholine and NG-monomethyl-L-arginine (L-NMMA) into the left main coronary artery were examined in 11 current smokers and 17 nonsmokers using quantitative coronary angiography. RESULTS: Acetylcholine dilated one-third of the proximal segments and most of the distal segments of coronary arteries in nonsmokers, whereas it constricted most of the proximal and distal segments in smokers. L-NMMA decreased the basal diameter of coronary arteries in nonsmokers but had minimal effect on the basal diameter in smokers. L-NMMA abolished the dilator response to acetylcholine in the coronary arteries of nonsmokers but had minimal effect on the constrictor response to acetylcholine in the arteries of smokers. The dilator response to nitroglycerin was significantly increased in the coronary arteries of smokers compared with in those of nonsmokers. The constrictor response to L-NMMA at rest was significantly correlated with the dilator response to nitroglycerin and with the diameter changes to acetylcholine in both smokers and nonsmokers. CONCLUSIONS: Nitric oxide bioactivity at rest and at acetylcholine-stimulated conditions in smokers was decreased, leading to the supersensitivity of the artery to the dilator effect of nitroglycerin as well as the constrictor effect of acetylcholine in smokers. Cigarette smoking affects nitric oxide-mediated regulation of coronary artery tone.

Acetylcholine↗
PubMed1996

Nitric oxide activity is deficient in spasm arteries of patients with coronary spastic angina.

BACKGROUND: Coronary spasm can be induced by acetylcholine, serotonin, ergonovine, or histamine, all of which cause vasodilation when the endothelium is intact by releasing nitric oxide (NO). Coronary spasm is promptly relieved by nitroglycerin, which vasodilates through its conversion to NO. It is thus possible that NO release may be deficient in the spasm arteries in patients with coronary spastic angina (CSA). The aim of this study was to determine whether NO release is deficient in coronary arteries of patients with CSA. METHODS AND RESULTS: NG-monomethyl-L-arginine (L-NMMA), an inhibitor of NO synthase, was infused into coronary arteries in 21 patients with coronary spastic angina (CSA) and in 28 control patients. Coronary spasm was induced by intracoronary injection of acetylcholine and was documented angiographically in all patients with CSA. L-NMMA dose-dependently decreased basal luminal diameter of coronary arteries in control patients, whereas it had no effect on basal diameter of the spasm arteries in patients with CSA. L-NMMA abolished the dilator response to acetylcholine and enhanced the constrictor response to acetylcholine in control arteries, whereas it had no effect on the constrictor response to acetylcholine in spasm arteries. Intracoronary infusion of L-arginine did not affect the diameter of spasm or control arteries. The dilator response to nitroglycerin was increased markedly in spasm arteries compared with control arteries, whereas response to diltiazem did not differ between them. CONCLUSIONS: There is a deficiency in endothelial NO activity in spasm arteries, which leads to the supersensitivity of the artery to the vasodilator effect of nitroglycerin and to the vasoconstrictor effect of acetylcholine in patients with CSA. This deficient endothelial NO activity plays an important role in the pathogenesis of coronary spasm.

Acetylcholine↗
PubMed1996

The Aspergillus nidulans genes chsA and chsD encode chitin synthases which have redundant functions in conidia formation.

We previously isolated three chitin synthase genes (chsA, chsB, and chsC) from Aspergillus nidulans. In the present work, we describe the isolation and characterization of another chitin synthase gene, named chsD, from A. nidulans. Its deduced amino acid sequence shows 56.7% and 55.9% amino acid identity, respectively, with Cal1 of Saccharomyces cerevisiae and Chs3 of Candida albicans. Disruption of chsD caused no defect in cell growth or morphology during the asexual cycle and caused no decrease in chitin content in hyphae. However, double disruption of chsA and chsD caused a remarkable decrease in the efficiency of conidia formation, while double disruption of chsC and chsD caused no defect. Thus it appears that chsA and chsD serve redundant functions in conidia formation.

Amino Acid Sequence↗
PubMed1996

Recurrent placental site trophoblastic tumor of the uterus: clinical, pathologic, ultrastructural, and DNA fingerprint study.

Placental site trophoblastic tumor is a rare disease. Most benign cases of this disease show a few mitotic figures of the tumor while recurrent cases usually have more than 5 mitoses per 10 high-power fields. The present case was primarily treated by hysterectomy and chemotherapy and had 2 mitoses in 10 high-power fields. After 1 years and 4 months of therapy the patients was diagnosed as ovarian metastasis because of gradually increasing serum beta-human chorionic gonadotropin (hCG) level and abnormally high fluid levels of beta-hCG and human placental lactogen (hPL) punctured from her cystic ovarian tumor. This recurrent case was further treated with another regimen of chemotherapy for 7 courses, and the serum beta-hCG level had decreased at present. This report describes the recurrent case and discusses the histology of a few mitotic figures, electron microscopic findings, and results of the DNA fingerprint analysis of the primary tumor.

Adult↗
PubMed1996

Expression of bone morphogenetic proteins in human osteogenic and epithelial tumor cells.

In addition to osteosarcomas some epithelial tumors also show bone induction, which is supposedly due to bone morphogenetic proteins (BMPs). However, the types of BMPs expressed in different kinds of tumors have not been studied extensively. In this study five human osteosarcoma and six human carcinoma cell lines were examined to investigate the bone induction and BMP mRNA expression. The cultured cells were transplanted in the subcutaneous tissue of athymic nude mice with or without diffusion chambers. Reverse transcription-polymerase chain reaction (RT-PCR) was used for the detection of BMP mRNAs. All osteosarcoma cell lines expressing all BMPs (BMP-1 to 7) examined, successfully formed bone or osteoid tissue irrespective of the use of a diffusion chamber. Bone formation was induced by diffusion chamber in an osteosarcoma cell line OST and a gastric adenocarcinoma cell line MKN45. OST cells lacked BMP-3 and 7, and MKN45 cells lacked BMP-3, 5 and 6. Our data suggest that BMP-3, 5, 6 and 7 are not always essential for bone induction in tumor cells.

Adenocarcinoma↗
PubMed1996

Biphasic intra-abdominal desmoplastic small cell tumor in a patient with proximal spinal muscular atrophy.

A case is reported of intra-abdominal desmoplastic small cell tumor (IDSCT) with biphasic histologic features in a patient with proximal spinal muscular atrophy. The tumor was composed of small epithelial cell nests with spindle cell sarcomatous areas. Both areas were surrounded by a desmoplastic stroma. Immunohistochemical studies revealed reactivity for low molecular weight cytokeratin, epithelial membrane antigen, vimentin, desmin and Leu-7 in both areas. Electron microscopic examination demonstrated paranuclear aggregates of intermediate filaments, zonula adherens and basement membrane-like material in the epithelial cells, while spindle cells in the tumor had fewer intracytoplasmic organelles. However, intermediate or transitional forms of both types of tumor cells were frequently observed. Although IDSCT are known to express multi-phenotypes immunohistochemically, attention should be paid to the broad spectrum of cell morphology in these tumors.

Adult↗
PubMed1996

Ossifying fibromyxoid tumor of the retroperitoneum.

A case of ossifying fibromyxoid tumor (OFMT) in an unusual site, the retroperitoneum, in a 71 year old Japanese man is reported. The well demarcated tumor contained a large amount of mature bony tissue within the tumor. The tumor cells were round to spindle-shaped, and showed a high cellularity in some areas and were loosely arranged in other areas. Although the majority of tumor cells expressed vimentin, neuron specific enolase and Leu-7, there were no tumor cells positive for S-100 protein, myogenic or epithelial markers. We would like to emphasize that tumors classified as OFMT contain a wide spectrum of histologic features and heterogeneity.

Aged↗
PubMed1996

Small-cell neuroendocrine carcinoma of the uterine cervix associated with micro-invasive squamous cell carcinoma and adenocarcinoma in situ.

A case of small-cell neuroendocrine carcinoma of the uterine cervix associated with squamous cell carcinoma and adenocarcinoma in situ is reported. The tumor consisted mainly of uniform small cells with a population of intermediate cells that resembled carcinoid tumor cells. Foci of micro-invasive squamous cell carcinoma and adenocarcinoma in situ were recognized separately, adjacent to the main tumor. Both Grimelius stain and immunostaining of serotonin were positive for small-cell and intermediate-cell carcinoma. Neurosecretory granules were demonstrated by electron microscopy. Microacini with positive mucin staining and microvilli-like structures suggested glandular or exocrine differentiation of the tumor. Three distinctive types of differentiation, neuroendocrine, exocrine and squamous characteristics, were expressed in the tumor.

Adenocarcinoma↗
PubMed1996

Menstrual cyclic variation of endothelium-dependent vasodilation of the brachial artery: possible role of estrogen and nitric oxide.

Estrogens have been reported to influence endothelial functions. This article's aim is to examine whether endothelium-dependent vasodilation of brachial arteries is changed in parallel with the physiological variation of the ovarian hormones during the menstrual cycle in young healthy female subjects. With high-resolution ultrasonography, we measured the diameter and blood flow of brachial arteries at rest, during reactive hyperemia, and after sublingual nitroglycerin administration in 15 young healthy female subjects (mean 29.6 +/- 2.6 years). All female subjects were studied in each of three different phases of one menstrual cycle (M, menstrual phase; F, follicular phase; L, luteal phase). The increase in arterial diameter during reactive hyperemia was lowest in the menstrual phase and highest in the follicular phase (4.9 +/- 0.8% in M; 14.1 +/- 0.9% in F; 9.2 +/- 1.1% in L; p < 0.005 between any two means among the groups). No significant difference was apparent in the percentage of increase in blood flow during reactive hyperemia among the three phases. The percentage of increase in arterial diameter after nitroglycerin administration also was not significantly different among the three phases of the cycle. The serum estradiol level was lowest in the menstrual phase and was highest in the follicular phase (17.5 +/- 1.6 pg/ml in M, p < 0.0005, M versus F and L; 107.8 +/- 18.0 pg/ml in F, p < 0.05, F versus L; 74.4 +/- 7.3 pg/ml in L). The serum level of nitrite-nitrate, measured by the Griess reaction, was highest in the follicular phase and was lowest in the menstrual phase of the three different phases (40.4 +/- 7.9 mumol/l in M, p < 0.01, M versus F, and p < 0.05, M versus L; 106.7 +/- 17.6 mumol/l in F, p < 0.05, F versus L; 62.2 +/- 6.2 mumol/l in L). In conclusion, a significant variation of the endothelium-dependent vasodilation parallels the levels of serum estradiol and nitrite-nitrate during the menstrual cycle in female subjects.

Adult↗
PubMed1995

Ovarian carcinoid with severe constipation due to peptide YY production.

We report a patient with primary trabecular carcinoid of the ovary with severe constipation probably due to peptide YY production by the tumor. A 43-year-old female had complained of severe constipation for several months and was found to have a left ovarian tumor. The surgically resected tumor was diagnosed as trabecular carcinoid by light microscopic examination. The carcinoid tumor cells were intensely and uniformly stained by the Grimelius technique. Immunohistochemically, the tumor cells were strongly positive for peptide YY, which has a strong inhibitory action on intestinal motility. The patient has been free from constipation since the removal of the tumor. The present case supports previously reported findings that not typical carcinoid syndrome but rather severe constipation accompanies primary trabecular carcinoid of the ovary, and that peptide YY is presumably the cause of the constipation.

Adult↗
PubMed1995

In vitro differentiation and proliferation in a newly established human rhabdomyosarcoma cell line.

A newly established cell line, designated NRS-1, was derived from an alveolar rhabdomyosarcoma that developed in the left forearm of a 7-year-old girl. The cell line had a t(2; 13) chromosomal translocation. Reverse transcription-polymerase chain reaction demonstrated that 5' PAX3-3' FKHR chimeric transcript was expressed in NRS-1 cells. NRS-1 cells showed myogenic differentiation without any particular stimulus in vitro and exhibited various kinds of muscle markers. All-trans retinoic acid promoted cell differentiation in the myogenic direction. Transforming growth factor-beta (TGF-beta) inhibited myogenic differentiation of those cells and promoted cell proliferation.

Base Sequence↗
PubMed1995

Bone formation in vitro and in nude mice by human osteosarcoma cells.

Osteosarcomas contain variable amounts of bony tissue, but the mechanism of bone formation by osteosarcoma is not well understood. While a number of cultured human osteosarcoma cell lines have been established, they are maintained by different media and differ qualitatively with regard to bone formation. We examined different media for their ability to support bone formation in vitro and found the alpha-modification of Eagle's minimal essential medium supplemented with beta glycerophosphate was best for this purpose, because it contained the proper calcium and phosphate concentrations. Subsequently, we compared seven human osteosarcoma cell lines under the same experimental conditions to clarify their ability to induce bone formation. NOS-1 cells most frequently exhibited features of bone formation in vitro and in nude mice. Collagen synthesis by tumour cells themselves seemed to be the most important factor for bone volume. However, even HuO9 cells, which lacked collagen synthesis and failed to form bone in vitro, successfully formed tumours containing bone in nude mice. Histological analysis of HuO9 cells in diffusion chambers implanted in nude mice and the findings of polymerase chain reaction indicated that the phenomenon was probably due to bone morphogenetic protein.

Adolescent↗
PubMed1995

Combined choriocarcinoma, hepatoid adenocarcinoma, small cell carcinoma and tubular adenocarcinoma in the oesophagus.

We describe an oesophageal tumour composed of choriocarcinoma, hepatoid adenocarcinoma, small cell carcinoma and tubular adenocarcinoma. The choriocarcinomatous areas and hepatoid adenocarcinomatous areas contained beta human chorionic gonadotropin-positive cells and alpha fetoprotein-positive cells, respectively. The small cell carcinomatous areas contained cells positive for serotonin or adrenocorticotrophic hormone, while the tubular adenocarcinomatous areas contained cells positive for carcinoembryonic antigen. Non-neoplastic gastric type columnar epithelium was found directly adjoing the tumour at the oral side. This tumour, with its unprecedented histology combination of tissues may have originated in Barrett's oesophagus, although we could not confirm a history of chronic gastro-oesophageal reflux.

Adenocarcinoma↗
PubMed1995

Intracranial germ cell tumors: detection of p53 gene mutations by single-strand conformation polymorphism analysis.

Using polymerase chain reaction-single-strand conformation polymorphism (PCR-SSCP) analysis, p53 gene mutation was examined in 12 intracranial germ cell tumors (5 yolk sac carcinomas and 7 germinomas), many of which were derived from young patients in the first to the second decade. A total of 10 mutations were detected in 4 of the 12 cases and, in 3 of them, the mutations were multiple or tandem. Among the 10 mutations, 7 were missense, 1 was splicing and 2 were silent. The 7 missense mutations were located at previously proposed hot spot codons or in their vicinity or, when outside the hot spots, at a codon encoding an amino acid conserved in most vertebrates. These findings suggested that all 7 missense mutations may actually give rise to functional alteration of the p53 protein. The splicing mutation was considered to be a germ-line mutation, though its biological effect was equivocal, since the neoplastic tissue contained an additional mutation. The pattern of the mutations was predominancy of G:C-A:T transition with frequent involvement of the CpG site. These mutations were more frequently detected in yolk sac carcinomas (60%; 3/5 cases) than in germinomas (14%; 1/7 cases), suggesting that the contribution of the p53 mutation to carcinogenesis differed with the histological type of the intracranial germ cell tumor.

Adolescent↗
PubMed1995

Clear cell chondrosarcomas arising from rare sites.

Three cases are reported of clear cell chondrosarcoma arising from unusual sites: talus, rib and vertebra. Radiographically, two tumors showed osteolytic features and the vertebral tumor showed osteoplastic change. Histologically, all tumors consisted of clear cells that had a centrally placed nucleus surrounded by clear cytoplasm, osteoclast-like giant cells, areas of conventional chondrosarcoma, and various amounts of reactive bone. The tumor in the talus was initially diagnosed as benign chondroblastoma, but it recurred. The rib tumor showed marked cystic formation stimulating aneurysmal bone cyst. The osteoplastic radiographic feature in vertebral tumor was considered to be due to the abundant bone formation.

Adolescent↗
PubMed1995

[Experimental pulmonary metastasis of Chinese hamster mesenchymal chondrosarcoma cell lines].

Pulmonary metastases of chinese hamster mesenchymal chondrosarcoma cell lines, MCS-1 (undifferentiated type) and MCS-8 (differentiated type), were examined by intravenous transplantation into athymic nude mice. The incidence of pulmonary metastasis of MCS-1 was 100% and that of MCS-8 was 33% at the 23rd day after transfer. Mean number of metastatic nodules in the lung was 41 in the former and only 3 in the latter. Mean survival time of mice with MCS-1 injection (5 x 10(4) cells) was 27 days and that with MCS-8 (5 x 10(4) cells) was 48 days after transfer. At the 42nd day after transfer of MCS-8, however, the incidence of pulmonary metastasis was 100%. These data suggest that the tumor growth rate in the metastatic lesion, as well as the affinity to the target organ, is very important for evaluation of experimental metastasis.

Animals↗
PubMed1995

[Usefulness of intracardiac echocardiography for guidance of transseptal puncture procedure].

The clinical usefulness of intracardiac echocardiography (ICE) for the guidance of transseptal puncture procedure during percutaneous left heart bypass support (PLHBS) and percutaneous transvenous mitral commissurotomy (PTMC) was investigated to replace intraoperative transesophageal echocardiography monitoring which requires mild sedation and causes patient discomfort. The ICE procedure was assessed in 3 patients with PLHBS and 18 with PTMC using a 10 MHz rotating 8 French probe system especially developed for the purpose. Transseptal puncture procedure was observed by intraoperative ICE monitoring in the right atrium. The ICE images showed the transseptal puncture (Brokenbrough) needle as a point casting an acoustic shadow. By moving the ICE probe up and down, the excursion of the needle and its approach to the septal wall could be clearly observed. If the puncture needle is forced into the intra-atrial septum, the septal wall was clearly observed to protrude into the left atrium (tent-formation). In a tent-formation the puncture site could be determined by ICE alone. Intracardiac echocardiography guidance was useful and may improve the safety and reliability of the transseptal puncture procedure in PLHBS and PTMC.

Adult↗