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Biomedical subjects

A Ohtsu

Publications and source records attributed to A Ohtsu.

86 records · Page 5Linked to original sources
PubMed1983

Estradiol suppresses electrically-induced arterial thrombosis by increasing prostaglandin biosynthesizing activity of the aorta in rats.

The anti-thrombotic effect of estradiol was studied using an electrically induced thrombus model in rats. Estradiol treatment significantly inhibited the thrombus formation induced by electric shock. In the meantime, a stimulation of prostacyclin biosynthesis by estradiol in aortas was found. This is the first report showing the correlation between the effects of the estradiol on the thrombus formation in an experimental model and on the prostacyclin production by aortas in the same animal system.

Animals↗
PubMed1981

Aggregation of platelets induced by novel synthetic secoprostaglandins.

Two series of 8-acetly-12-hydroxyalkadienoic acids and 14-hydroxy-9-oxoalkadienoic acid which can be regarded as 11,12- and 8,12- secoprostaglandin E2 were synthesized and evaluated for their biological properties. Key members of each series, 11,12-(8Ac-HAD) and 8, 12-seco-11-norprostaglandin E2 (14H-OAD), were found to induce platelet aggregation which were inhibited by preincubation of platelet rich plasma with prostaglandin I2 but not inhibited by indomethacin, 8Ac-HAD produced dose-dependent potent contraction of rabbit aorta. Injection of 8Ac-HAD (1 mg/kg) into vein of rat induced sudden death of the animal. Both compounds were stable and platelet aggregating activity did not decrease at least for four hours at 0 degree C. Structure-activity relationship study of the series were carried out. Reduction of the acetyl carbonyl and methoxime formation of 8Ac-HAD lowered platelet aggregating activity, and 8-propionyl substituent and 12-deoxy derivative of 8Ac-HAD showed no activity. 12 (R)-Isomer and dl 12-methyl derivative of 8Ac-HAD retained the platelet aggregating activity. Modification of omega-chain did not cause any essential effect on the activity. Unlike 8Ac-HAD, several modification of 14H-OAD failed to maintain the aggregating activity.

Animals↗
PubMed1980

Structure-activity relationships of novel 3-acylpyrrole derivatives: new inhibitors of platelet aggregation.

Several N-substituted-3-acyl-2, 5-dimethyl pyrrole derivatives were examined for their potency to inhibit aggregation of platelets in vitro and extra vivo in guinea pigs. A structure-activity relationship study showed that the substitution at 3 position of the pyrrole ring affected in vitro activity of inhibiting platelet aggregation. Compounds with 3-benzoyl or 3-thenoyl substituent had greater potency than those with 3-aliphatic acyl substituent. Modification of benzoyl, such as para substitution of phenyl group or reduction of carbonyl group, decreased the activity. There was no clear correlation between that N-substitution of the pyrrole ring and in vitro anti-platelet activity. However, compounds with a longer alkyl chain in the N-substituent had weaker activity. The in vitro inhibitory activity on prostaglandin synthetase of these compounds, though less potent compared with their antiplatelet activity, has a close correlation with the latter. N-substituents of the pyrrole ring had the effect on extra vivo activity. Compounds which have no N-alpha-methyl group and no hetero atoms such as oxygen or sulfur in the N-substituent diminished the extra vivo activity.

Animals↗
PubMed1980

Inhibition of prostaglandin synthesizing enzymes by haptoglobin and plasma of rats with inflammation.

Administration of carrageenin or adjuvant to rats to induce inflammation produced increases in the plasma haptoglobin level. Simultaneously, there was an increase in the activity of the plasma inhibitor of prostaglandin E2 synthesis. Partially purified haptoglobin inhibited the microsomal over-all conversion of arachidonic acid to prostaglandin E2. The addition of the haptoglobin inhibited two heme-dependent reactions catalyzed by a purified enzyme of seminal vesicle microsome, i.e., the prostaglandin G2 synthesis from arachidonic acid and the conversion of prostaglandin G2 to H2. However, the plasma inhibitory activity was accounted for only partially by the haptoglobin contained in the plasma from treated rats.

Animals↗
PubMed1977

Development of an intravenous gamma-globulin with Fc activities. I. Preparation and characterization of S-sulfonated human gamma-globulin.

S-sulfonated gamma-globulin (S-GG) was prepared by treating gamma-globulin with sulfite and tetrathionate ions. About four interchain disulfide bonds were selectively cleaved to give S-sulfonate groups. Although the above treatment strongly suppresses anticomplementary activity and nonspecific skin reactivity, the resulting S-GG retains high antibody activity. Furthermore, S-GG was found to maintain satisfactory levels for prolonged periods in vivo. The physicochemical and antigenic analyses of S-GG suggest that the S-sulfonation induces structural modification only at restricted sites.

Complement Fixation Tests↗
PubMedDate not supplied

Haplotype structures of the UGT1A gene complex in a Japanese population.

Genetic polymorphisms of UDP-glucuronosyltransferases (UGTs) are involved in individual and ethnic differences in drug metabolism. To reveal co-occurrence of the UGT1A polymorphisms, we first analyzed haplotype structures of the entire UGT1A gene complex using the polymorphisms from 196 Japanese subjects. Based on strong linkage disequilibrium between UGT1A8 and 1A10, among 1A9, 1A7, and 1A6, and between 1A3 and 1A1, the complex was divided into five blocks, Block 8/10, Block 9/6, Block 4, Block 3/1, and Block C, and the haplotypes for each block were subsequently determined/inferred. Second, using pyrosequencing or direct sequencing, additional 105 subjects were genotyped for 41 functionally tagged polymorphisms. The data from 301 subjects confirmed the robustness of block partitioning, but several linkages among the haplotypes with functional changes were found across the blocks. Thus, important haplotypes and their linkages were identified among the UGT1A gene blocks (and segments), which should be considered in pharmacogenetic studies.

Asian People↗
PubMedDate not supplied

Streptococcus milleri infection and pericardial abscess associated with esophageal carcinoma: report of two cases.

We report 2 cases of esophageal carcinoma with esophago-mediastinal fistula that developed pericardial abscess due to Streptococcus intermedius infection. Streptococcus intermedius, a generally harmless commensals in healthy humans, is not usually associated with infections of the oral cavity but may account for non-oral purulent infections. This report, however, highlights that Streptococcus intermedius infection can be life-threatening for some patients such as those with esophageal carcinoma with fistula.

Abscess↗
PubMedDate not supplied

Drainage area of the head of the pancreas by computed tomography under endoscopic retrograde pancreatography (ERP-CT).

BACKGROUND/AIMS: This study evaluated the drainage area of the capitular branches of the pancreas head by computed tomography under endoscopic retrograde pancreatography (ERP-CT). METHODOLOGY: ERP-CT was performed in 43 patients. The drainage area of the capitular branches of Wirsung's and Santorini's ducts were evaluated by dividing the pancreatic head into two areas, the anterior area and the posterior area. RESULTS: The pancreatic duct pattern was classified in 4 types; normal type, ansa type, loop type, and embryonic type. In normal type duct pattern, all inferior capitular branches of Wirsung's duct drained the posterior area and all inferior capitular branches of Santorini's duct drained the anterior area. In ansa type duct pattern, all inferior branches from Wirsung's duct drained the posterior area and inferior branches from Santorini's duct drained the anterior area and the posterior area. In loop type duct pattern, all inferior branches from Santorini's duct drained the posterior area and inferior branches from Wirsung's duct drained the anterior area and the posterior area. Middle capitular branches were detected only in normal B, normal C, and loop type. CONCLUSIONS: ERP-CT is a useful procedure that provided three-dimensional morphology of the capitular branch of the pancreas head.

Cholangiopancreatography, Endoscopic Retrograde↗
PubMedDate not supplied

Primary squamous cell carcinoma of the stomach: a case report with a review of Japanese and Western literature.

A case of a 75 year-old male with primary squamous cell carcinoma of the stomach is reported. It is extremely rare to see squamous cell carcinoma developing in the stomach, without being accompanied by a component of adenocarcinoma. Up to the present, 18 Japanese and 62 Western cases of this type of carcinoma have been reported in the literature. The origin of this malignancy has not been well elucidated yet and thus, several plausible hypotheses have been proposed. In this presented case, the tumor consisted of only squamous cell carcinoma and the focus of squamous metaplasia was not found histologically in the adjacent mucosa. Therefore, it may be considered that the carcinoma arises from misplaced squamous cell nests of the stomach.

Aged↗