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Biomedical subjects

O Tanaka

Publications and source records attributed to O Tanaka.

At least 127 records · Page 7Linked to original sources
PubMed1994

The effect of bunazosin on monocrotaline-induced pulmonary hypertension in rats.

In order to estimate the long-term hemodynamic and histologic effects of bunazosin hydrochloride on primary pulmonary hypertension (PPH), for which effective internal therapy has not yet been proposed, we produced subacute pulmonary hypertension in 6 week old Sprague-Dawley rats by injecting one dose of monocrotaline. Bunazosin (10 mg/kg) was administered intraperitoneally every day and bodyweight and hemodynamic parameters were measured. Right ventricle (RV) and left ventricle with septum (LV +S) were weight separately. Medial thickness of the small pulmonary artery was calculated. In the bunazosin group, the increase of right ventricular systolic pressure (RVSP) as pulmonary arterial systolic pressure and the ratio of RVSP to pulmonary flow were limited, without causing systemic hypotension, compared to the control group. Weight ratio of RV/(LV +S) had a tendency to be limited in the bunazosin group. As for medial thickness, there was no significant difference between the two groups. It may be concluded that bunazosin hydrochloride should be considered for clinical trials in treatment of PPH in humans.

Adrenergic alpha-Antagonists↗
PubMed1994

Development of the lens in human embryos: a histochemical and ultrastructural study.

The early development of the lens was examined, using 36 externally normal human embryos at Carnegie stages 13-23 (4 to 8 weeks of gestation). Twenty-two embryos were sectioned serially and stained with periodic acid-Schiff and a modified method of PAS. In 14 embryos, not only the differential distribution of glycogen but also the ultrastructural change in the developing lens, with special reference to junctional complexes, were examined electron microscopically. At stage 15, when the lens vesicle was formed, glycogen was observed in the cytoplasm of the lens epithelium, especially in the posterior lens epithelium. From stages 16 to 18, when the posterior lens epithelium was differentiated into the primary lens fibers and elongated toward the anterior lens epithelium, the amount of glycogen increased in the basal cytoplasm of the primary lens fiber, where the intracellular organelles, such as the tubular vesicles, mitochondria and multivesicular bodies, began to aggregate. At stage 20, when the lens cavity was obliterated, glycogen was also present in the anterior lens epithelium. At stage 21, as the formation of the secondary lens fibers proceeded, glycogen was noted in the secondary lens fibers in the equator region. These findings suggest that the distribution of glycogen is associated with the formation of the primary and secondary lens fibers. In addition, we provide additional information that a lot of glycogen is distributed in the region where many intracellular organelles aggregate in the embryonic lens vesicles.

Glycogen↗
PubMed1994

Inhibitory effects of cucurbitane triterpenoids on Epstein-Barr virus activation and two-stage carcinogenesis of skin tumors.

To search for possible anti-tumor-promoters, we carried out a primary screening of 21 cucurbitane triterpenoids using an in vitro assay system. Of these triterpenoids, scandenoside R6 (6), 23,24-dihydrocucurbitacin F (14), 25-acetyl-23,24-dihydrocucurbitacin F (15), 2-O-beta-D-glucopyranosyl-23,24-dihydrocucurbitacin F (17) and cucurbitacin F (18) exhibited significant inhibitory effects on Epstein-Barr virus (EBV) activation induced by the tumor promoter, 12-O-tetradecanoyl-phorbol-13-acetate (TPA). Further, compounds 14 and 17 exhibited remarkable anti-tumor-promotion effects on mouse skin tumor promotion in an in vivo two-stage carcinogenesis test.

Animals↗
PubMed1994

Saponins from Vietnamese Ginseng, Panax vietnamensis HA et Grushv. Collected in central Vietnam. II.

Further investigation on the saponin composition of rhizomes and roots of Panax vietnamensis HA et GRUSHV. has resulted in the isolation and structural elucidation of seven new dammarane saponins named vina-ginsenosides-R3 (12), -R4 (11), -R5 (16), -R6 (17), -R7 (6), -R8 (20), -R9 (22), together with the identification of six known saponins including 20-gluco-ginsenoside-Rf (10), ginsenoside-Rc (4), notoginsenoside-R6 (9), quinquenoside-R1 (5), gypenoside XVII (2) and majoroside F1 (21). The structures of the novel saponins were established on the basis of chemical and spectral evidence. Vina-ginsenoside-R3 is the first naturally occurring glycoside of dammarenediol II, while vina-ginsenosides-R5 and -R6, two ocotillol-type saponins, are two other examples of saponins having the rare alpha-glucosyl linkage.

Carbohydrate Sequence↗
PubMed1994

Saponins from Vietnamese ginseng, Panax vietnamensis Ha et Grushv. collected in central Vietnam. III.

Five new dammarane saponins derived from four new aglycones were isolated from the rhizomes and roots of Panax vietnamensis Ha et Grushv. On the basis of physicochemical and spectral evidence, the structures of these compounds were established as 6-O-beta-D-glucopyranosyl 20(S),25-epoxydammarane-3 beta,6 alpha,12 beta,24 alpha-tetrol (1), 6-O-beta-D-xylopyranosyl-(1-->2)-beta-D-glucopyranosyl 20(S),25-epoxydammarane-3 beta,6 alpha,12 beta,24 alpha-tetrol (2), 6-O-beta-D-glucopyranosyl dammarane-3 beta,6 alpha,12 beta,20(S),24 xi,25-hexol (5), 3-O-[beta-D-glucopyranosyl-(1-->2)-beta-D-glucopyranosyl]-20-O-beta-D- glucopyranosyl dammarane-3 beta,12 beta,20(S),24 xi,25-pentol (8) and 6-O-beta-D-xylopyranosyl-(1-->2)-beta-D-glucopyranosyl 20(S),24(S)-epoxydammarane-3 beta,6 alpha,12 beta,25 xi,26-pentol (10). The trivial names, vina-ginsenoside-R10, -R11, -R12, -R13 and -R14, respectively, were assigned to the new saponins.

Carbohydrate Sequence↗
PubMed1994

Sweetness of glycyrrhetic acid 3-O-beta-D-monoglucuronide and the related glycosides.

To improve the taste profile of glycyrrhizin (1, the saponin of licorice root, relative sweetness to sucrose: x170), a variety of 3-O-glycosides of glycyrrhetic acid were prepared and their sweetness evaluated. It was found that a significant enhancement of sweetness was observed for the 3-O-beta-D-xyloside and the 3-O-beta-D-glucuronide (MGGR). Especially, MGGR had a high sweetness relative to sucrose; x941, and would appear to be a new potent sweetener.

Carbohydrate Sequence↗
PubMed1994

Investigations on the growth pattern of the maxillary sinus in Japanese human fetuses.

The growth pattern of the maxillary sinus was analyzed using 18 human fetuses of both sexes between 9 and 21 weeks of age postconception. The paraffin embedded specimens were cut in series in the frontal and the transversal plane, respectively. The inner surface of the maxillary sinuses was redrawn and surrounded with a digitizer and then the volumes were calculated. A correlation analysis as well as a simple linear regression analysis between the values of the maxillary sinus, different linear values of the nasal cavity and the crown-rump length (CRL) served to prove possible growth relations. The maxillary sinus' Anlage was already identifiable in the 29.8 mm (CRL) fetus. From this first appearance, the maxillary sinus expands not only in posterior direction but also in anterior direction from 11 weeks onwards. The maxillary sinus volume increased from 0.0008 mm3 at the age of 9 weeks to more than 9 mm3 at the age of 21 weeks. The results of the statistical analysis indicated, that the relationship between the maxillary sinus' Anlage and the nasal cavity were strongly influenced by the body size (CRL). This study suggests, that the growth of the maxillary sinus follows special regularities in the early fetal development.

Embryonic and Fetal Development↗
PubMed1994

[Aberrant expression of carbohydrate antigens in squamous cell carcinoma of the tongue].

An immunohistochemical study was performed to observe the aberrant expression of blood-related group antigens in squamous cell carcinomas of the tongue from 10 patients and 13 normal tongue tissues using seven monoclonal antibodies, A, B, H, X001, H001, Lea and Leb, and four lectins, PNA, VVA-B4, UEA-1 and LTA. In SCC, Leb antigens were expressed in all cases examined (10 cases). T and Tn antigens which were examined with PNA and VVA-B4 stains, were expressed in seven out of 10 and six out of 10 cases, respectively, while these two antigens were not found in normal tissues. A, B and H antigens were expressed in most normal tongue epithelial cells, strictly dependent on the patient blood type. But in SCC, A and B antigens were not detected in five out of seven cancer cells from blood group A, B and AB individuals, whereas H antigen was expressed in 5 out of 7 cancer cells from blood group A, B and AB individuals. These results suggest that the expression of blood group-related antigens in suppressed to that of more immature carbohydrate chains in the setting of tongue cancer.

Adult↗
PubMed1994

[A case of liver metastasis of leiomyosarcoma of residual stomach successfully treated by TAE and intra-hepato-arterial chemotherapy with infusion-a-port with administration of epirubicin].

A 60-year-old man who had a partial gastrectomy for gastric cancer 10 years ago was referred to our hospital for further examination for liver tumor. He was diagnosed as leiomyosarcoma of residual stomach associated with liver metastases. After preoperative transarterial embolization (TAE) with epirubicin of the anterior branch of right hepatic artery, residual stomach was resected, and the reservoir catheter and infusion arterial port were implanted. He was treated by intra-hepato-arterial chemotherapy of epirubicin. The patient has remained well for 2 years and 3 months without apparent complications.

Embolization, Therapeutic↗
PubMed1994

[Pulmonary root reconstruction with a cryopreserved pulmonary allograft for mechanical pulmonary valve thrombosis].

A 58-year-old woman suffering from congestive heart failure caused by a mechanical pulmonary valve thrombosis was operated on with a pulmonary allograft. She had experienced pulmonary valvotomy and resection of infundibular stenotic muscle for congenital pulmonary stenosis at the age of 23 years old. She got congestive heart failure caused by pulmonary regurgitation, and underwent pulmonary valve replacement with a St. Jude Medical (SJM) valve when she was 48 years old. She suffered from episodes of a thrombosed SJM valve in 1984 and 1993. Each time, thrombolytic treatment with urokinase or recombinant tissue-type plasminogen activator was effective. She suffered from the third episode of SJM valve thrombosis in January 1994. As thrombolytic treatment was not effective this time, the thrombosed SJM valve was resected and her pulmonary root was reconstructed with a cryopreserved pulmonary allograft. Postoperative course was uneventful, and she now enjoys her life without anticoagulant therapy.

Cryopreservation↗
PubMed1994

[Hypothermic cardiopulmonary bypass with circulatory arrest of the lower half of the body and selective perfusion of the upper and lower half of the body for thoracic aortic aneurysm operation].

A 62-year-old man with thoracoabdominal aortic aneurysm of Crawford type IA and a 61-year-old woman with triple descending thoracic aortic aneurysms were operated on under total cardiopulmonary bypass with hypothermic circulatory arrest of the lower half of the body (rectal temperature of 17-19 C) and low flow selective perfusion of the upper and lower half of the body. Low porosity woven Dacron UBE grafts without preclotting were used for the replacement of the aorta. Postoperative courses were uneventful without paraplegia and angiographic examination revealed excellent hemodynamic results.

Aortic Aneurysm, Thoracic↗
PubMed1994

[Research on the correlation between DNA recombinational mutation and cancer malignancy in human colon cancers].

The mutagenicity of quercetin, a flavonoid, was examined by means of DNA fingerprint analysis using the Pc-1 and Pc-2 minisatellite probes that efficiently detect mutations due to recombination. Treatment of FM3A and BMT-11 tumor cells with 55 microM quercetin resulted in gain and loss of bands in the fingerprints in both cell lines. The frequencies of the clones having undergone mutation were 9/26 and 2/11, using Pc-1 probe, respectively, in the two lines. These results seem to provide a molecular basis for the phenotypic variations of BMT-11 tumor cells induced by quercetin, giving direct evidence of genetic instability of the tumor cells. Moreover, we examined for a possible correlation between frequencies of DNA recombinational mutations and cancer malignancy in human colon cancers. DNA of four human colon cancer tissues and corresponding peripheral blood cells were prepared, respectively, and examined by DNA fingerprint analysis using hPc-1 polymorphic minisatellite probe. These four specimens exhibited no extra-bands resulting from recombination and/or DNA slippage at present. We would explain how the prognosis of cancer patients is related to frequencies of DNA recombinational mutation.

Aged↗
PubMed1993

Resting energy expenditure in patients undergoing transhiatal or transthoracic oesophagectomy for carcinoma of the thoracic oesophagus.

Resting energy expenditure (REE) was studied in five patients undergoing transhiatal and in 14 undergoing transthoracic oesophagectomy for carcinoma. All resections were performed with an intention to cure. REE was measured by indirect calorimetry before operation and on days 1, 3, 5 and 7 after surgery. Following transthoracic oesophagectomy, REE increased significantly on days 1, 3, 5 and 7 after operation, and on day 7 the value was significantly higher (P < 0.05) than that obtained after transhiatal surgery. Energy expenditure following transhiatal oesophagectomy is lower than that after transthoracic oesophagectomy; this may be a result of reduced surgical stress.

Adult↗
PubMed1993

Molecular cloning of a novel isotype of Mg(2+)-dependent protein phosphatase beta (type 2C beta) enriched in brain and heart.

Two complementary DNA (cDNA) clones (pTK-1 and -2) encoding two distinct isotypes of mouse Mg(2+)-dependent protein phosphatase beta (MPP beta-1 and -2, respectively) were isolated from a melanocyte cDNA library. Although mouse pTK-1 is orthologous to the rat cDNA (JW5) reported previously [Wenk, J., Trompeter, H.I., Pettrich, K.G., Cohen, P.T.W., Campbell, D.G., and Mieskes, G. (1992) FEBS Lett. 297, 135-138], pTK-2 is a novel cDNA clone. It was strongly suggested that the pTK-1 and -2 cDNAs are splicing variants of a single pre-mRNA. The difference in the amino acid sequences between MPP beta-1 and -2 was observed only at the carboxy-terminal regions. Both the recombinant MPP beta-1 and -2 expressed in Escherichia coli cells were immunoreactive to an anti-MPP beta antibody and exhibited Mg(2+)-dependent and okadaic acid-insensitive protein phosphatase activities with similar substrate specificities. Although the mRNA of MPP beta-1 was expressed ubiquitously in various mouse tissues, that of MPP beta-2 was expressed exclusively in brain and heart. These results suggest the difference in the physiological roles of these two enzyme isotypes.

Amino Acid Sequence↗
PubMed1993

Ultrastructure of the developing stomach in human embryos.

Ultrastructural development of the stomach was studied by light, scanning electron and transmission electron microscopy, using 19 human embryos at Carnegie stages from 14 to 23 (6.8-28.0 mm in crown-rump length, 5 to 8 weeks of gestation). The precise time of appearance of differentiated characteristic structures was examined electron microscopically. The first gastric pit, with radially arranged epithelial cells beneath which the basement membrane bulged into the mesenchyme, was observed on the lesser curvature at stage 22. Although the mesenchymal condensation which would develop into the inner circular muscle layer appeared at stage 18 onward, cytoplasmic myofibrils were not observed until stage 22. Nerve fibers were first observed at stage 16, and at later stages they gathered into bundles to form a nerve plexus external to the developing inner circular muscle layer. On the basis of accurate timing of the appearance and the mode of development of these structures, possible relations between developing gastric layers were discussed. Histocytochemically, glycogen or other carbohydrates were demonstrated in the cytoplasm of the gastric epithelium throughout the stages examined. These carbohydrates were localized mainly in vacuole-like spaces in the basal part of the epithelial cells. This subcellular localization, and the amount of carbohydrate, did not change significantly during the observed embryonic period. In the serosa, carbohydrates were not detected at stages 14 and 15, but observed consistently within the vacuoles in the cytoplasm from stage 17 onward. No other layer of the embryonic stomach had detectable carbohydrates.(ABSTRACT TRUNCATED AT 250 WORDS)

Embryo, Mammalian↗
PubMed1993

Primary small cell carcinoma of the esophagus with ectopic gastrin production. Report of a case and review of the literature.

A case of primary small cell carcinoma of the esophagus in which extensive hormonal studies could be performed is reported. The tumor was considered as a neuroendocrine tumor because the tumor cells showed intracytoplasmic argyrophilia, neurosecretory granules, and positive stain for neuron-specific enolase with Grimelius stain, electron microscopy, and immunohistochemistry, respectively. Furthermore, the tumor was regarded as a gastrin-producing tumor because of positive stain for gastrin in the tumor cells. The present case is the first case of primary small cell carcinoma of the esophagus with ectopic gastric production.

Carcinoma, Small Cell↗
PubMed1993

Prediction of plasma concentrations of mianserin and desmethylmianserin at steady state from those after an initial dose of mianserin.

The relationships between the plasma concentrations of mianserin and desmethylmianserin at 18 h after initial dosing and those at steady state were studied in 19 depressed patients receiving 30 mg of mianserin at bedtime. Significant linear relationships were observed for mianserin, desmethylmianserin, and mianserin plus desmethylmianserin. The present study thus suggests that the plasma concentrations of these compounds after an initial dose of mianserin can be used for the prediction of an optimal dose.

Adult↗