Biomedical subjects

S Onodera

Publications and source records attributed to S Onodera.

At least 91 records · Page 5Linked to original sources

PubMed1995

Comparison of 5-hydroxytryptamine-induced contraction of rat pulmonary artery to that of aorta in vitro.

We investigated the nature of the contraction produced by 5-hydroxytryptamine (5-HT) in the rat pulmonary artery, and compared it with that produced in the rat aorta. Both ketanserin and ritanserin inhibited 5-HT-induced contraction in the pulmonary artery non-competitively. In contrast, ketanserin competitively antagonized the contraction in the aorta. Bunazosin, a selective alpha 1-blocker, partially inhibited 5-HT-induced contraction in the pulmonary artery, but not in the aorta. In both the pulmonary artery and aorta, 8-OH-DPAT, a 5-HT1A selective agonist, produced a concentration-dependent contraction. In the pulmonary artery, 5-HT and 8-OH-DPAT produced contractions with similar potencies. In contrast, 8-OH-DPAT was less potent than 5-HT in the aorta. Bunazosin inhibited 8-OH-DPAT-induced contraction in both vessels. However, pindolol, a 5-HT1A antagonist, did not inhibit 8-OH-DPAT-induced contraction in the pulmonary artery. These results suggest that 5-HT produces contraction via not only 5-HT2 receptor, but also non-5-HT2 receptor (probably alpha 1-adrenoceptor) in the rat pulmonary artery. Furthermore, 8-OH-DPAT does not activate the 5-HT1A receptor to produce a contraction, but does activate other receptors which interact with alpha 1-adrenoceptor.

8-Hydroxy-2-(di-n-propylamino)tetralin↗

PubMed1995

[Studies on histamine H2-receptor antagonistic property of FRG-8813, a novel anti-ulcer drug].

The present study was conducted to investigate the histamine H2-receptor antagonistic property of FRG-8813 by using isolated guinea pig right atria, gastric cells and cerebral cortex preparations. FRG-8813 inhibited the histamine-induced positive chronotropic response of the right atria and shifted the concentration-response curve of histamine to the right with suppression of the maximal response. Although the inhibitory effect of FRG-8813 was enhanced in a time-dependent manner and long-lasting, the antagonism was reversible. The potency of FRG-8813 was 2 times and 50 times greater than those of famotidine and cimetidine, respectively. FRG-8813 decreased the histamine-induced [14C]aminopyrine accumulation in gastric cells. Schild plot analysis showed that the slopes of FRG-8813, famotidine and cimetidine were 1.56, 1.40 and 1.07, respectively, suggesting that the mode of the antagonism of FRG-8813 is also unsurmountable in gastric cells. The lack of effect on dbcAMP- and bethanechol-induced [14C]aminopyrine accumulations indicated the selectivity of FRG-8813 for histamine H2-receptor. As in the right atria, the potency of H2-antagonism was 1.5 times and 40 times greater than those of famotidine and cimetidine, respectively. In the [3H]tiotidine binding study of the cerebral cortex preparation, the Ki values showed that the affinity of FRG-8813 was 2 times and 80 times more potent than those of famotidine and cimetidine, respectively. In conclusion, FRG-8813 is an unsurmountable and selective histamine H2-receptor antagonist with 2 times greater potency than famotidine. The antagonistic activity is reversible in spite of the time-dependent increase of the antagonism.

Acetamides↗

PubMed1995

Gastroprotective activity of FRG-8813, a novel histamine H2-receptor antagonist, in rats.

FRG-8813 ((+/-)-2-(furfurylsulfinyl)-N-[4-[4-(piperidinomethyl)-2- pyridyl]oxy-(Z)-2-butenyl]acetamide) is a novel histamine H2-receptor antagonist with gastric antisecretory and gastroprotective activities. The present study was designed to investigate the property of gastroprotective action. The oral ED50 values for inhibition of mucosal lesions against 1% NH3-, 60% ethanol in 0.15 N HCl-, 100% ethanol-, 0.6 N HCl- and sodium taurocholate in 0.4 N HCl-induced damage were 3.3, 11.1, 14.9, 23.3 and 23.1 mg/kg, respectively. FRG-8813 was gastroprotective despite pretreatment with omeprazole, suggesting that the protective effect is independent of its antisecretory activity. It is unlikely that FRG-8813 works as a mild irritant because it showed a gastroprotective effect after intraperitoneal injection, but oral administration itself did not influence the rat gastric mucosa. Although pretreatment with indomethacin or N-ethylmaleimide did not affect the gastroprotection of FRG-8813, chemical deafferentation induced by capsaicin abolished the gastroprotection. Furthermore, prior administration of tetrodotoxin, the calcitonin gene-related peptide (CGRP) antagonist hCGRP or NG-nitro-L-arginine attenuated the gastroprotection of FRG-8813 as well as that of capsaicin. In contrast to capsaicin, repeated administration of FRG-8813 neither enhanced the susceptibility of the mucosa to damage nor affected the gastroprotective action of short-term treatment. In conclusion, these results suggest that FRG-8813 has gastroprotective activity independently of acid antisecretory activity and that capsaicin-sensitive nerves may be partially or fully involved in the gastroprotective mechanisms of FRG-8813.

Acetamides↗

PubMed1995

[A study of tumor location and prognosis in renal pelvic and ureteral cancer].

A total of 245 patients with renal pelvic and ureteral cancer (transitional cell carcinoma) were retrospectively analysed for tumor location and prognosis. In 133 renal pelvic cancer patients, 34 patients (25.6%) had tumor in lower calyx, 33 patients (24.8%) in renal pelvis, 31 patient (23.3%) in upper calyx, 21 patients (15.8%) in whole renal pelvis and 7 patients (5.2%) in middle calyx, respectively. In 128 ureteral cancer patients, 60 patients (46.9%) had tumor in lower ureter, 27 patients (21.1%) in distal end of ureter, 26 patients (20.3%) in middle ureter, 12 patients (9.4%) in upper ureter and 3 patients (2.3%) in whole ureter. In combination of tumor location, 101 patients (41.2%) had tumor in only renal pelvis, 94 patients (38.4%) had in only ureter, 14 patients (5.7%) had in renal pelvis and ureter, 19 patients (7.8%) had in renal pelvis and bladder, 12 patients (4.9%) had in ureter and bladder, and 5 patients (2%) had in renal pelvis, ureter and bladder. Five year survival rate of renal pelvic cancer according to tumor location were 55.9% in upper calyx tumor, 60.8% in middle calyx tumor, 63.8% in lower calyx tumor, 60.2% in renal pelvic tumor and 63.8% in PUJ tumor, respectively. There were no significant difference between those 5 groups. Five years survival rate of ureteral cancer according to tumor location, 90% in upper ureteral tumor, 60.8% in middle ureteral tumor, 66.5% in lower ureteral tumor and 52.6% in tumor of distal end of ureter, respectively. Also in those 4 groups, there were no significant difference.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1995

Mesangiolysis associated with severe glomerular endocapillary proliferation of CD57 large granular lymphocytes.

A 54-year-old man developed renal failure, with renal biopsy findings of diffuse mesangiolysis with severe endocapillary proliferation. Immunohistochemical studies revealed that CD3-CD56-CD57+ large granular lymphocytes were present predominantly within glomerular tufts. Intercellular adhesion molecule-1 was more preferentially expressed in the glomerular endothelial cells with severe endocapillary proliferation as compared to those without endocapillary proliferation. These findings suggest that CD57+ large granular lymphocytes caused glomerular endothelial injury by a cell-mediated cytolytic mechanism, resulting in the development of mesangiolysis and microaneurysm formation.

Antigens, CD↗

PubMed1994

Absence of antioxidant effects of nifedipine and diltiazem on myocardial membrane lipid peroxidation in contrast with those of nisoldipine and propranolol.

Both the production of active oxygen species and cellular damage due to concurrent lipid peroxidation are believed to be important factors in the pathogenesis of cardiovascular diseases and the ageing process. Since cardiovascular drugs are often administered over a long term, it might be advantageous if they reduced lipid peroxidation. There have been conflicting reports concerning the antiperoxidant effect of nifedipine. Therefore, we investigated whether nifedipine could inhibit lipid peroxidation in a nonenzymatic active oxygen-generating system, utilizing rat crude myocardial membranes, and compared its effect with those of propranolol, nisoldipine, and diltiazem. Nifedipine and diltiazem had no inhibitory effects on the lipid peroxidation of myocardial membranes. In contrast, nisoldipine and propranolol had a concentration-dependent antiperoxidant effect, with IC50 values of 28.2 and 50.1 microM, respectively. In addition, nisoldipine appeared to possess dual antiperoxidant mechanisms, involving both preventive and chain-breaking properties.

Animals↗

PubMed1994

RNA structural requirements for stability and minus-strand synthesis in the dsRNA bacteriophage phi 6.

Bacteriophage phi 6 has a genome consisting of three segments of double-stranded RNA designated L, M, and S. Each virion contains one of each genomic segment. Empty procapsids can package plus-strand transcripts of the genomic segments if the 5' regions are intact. Minus-strand synthesis takes place if all three segments are packaged and if the 3' end of the segment is intact. The 3' ends of the segments contain four hairpin structures within a region of high sequence conservation. We now show that removal of parts of this region leads to progressive but limited loss of ability to support minus-strand synthesis. The defective 3' ends can be corrected by heterologous recombination with the termini of other segments. Segments that have small deletions in the conserved region and that support apparently normal minus-strand synthesis are highly recombinogenic.

Bacteriophage phi 6↗

PubMed1994

Sterol composition in polyene antibiotic-sensitive and resistant strains of Malassezia pachydermatis.

The membrane sterol compositions of ten strains of Malassezia pachydermatis were analysed by gas-liquid chromatography. Six of these were wild-type strains from clinical sources that were sensitive to polyene antibiotics, whereas the other four strains were resistant mutants that had arisen after treatment with N-methyl-N'-nitrosoguanidine or UV radiation. The wild-type strains contained 838.8 to 1291.7 micrograms of sterol per gram of freeze-dried mycelium. The sterols were composed of 79% ergosterol, 19% fecosterol and 2% lichesterol. The mutant strains contained 277.1 to 348.8 micrograms/g of sterols composed of 76% ergosterol and 24% fecosterol.

Chromatography, Thin Layer↗

PubMed1994

Mechanism of the biphasic effect of ethylenediaminetetraacetate on lipid peroxidation in iron-supported and reconstituted enzymatic system.

The biphasic action of ethylenediaminetetraacetate (EDTA), depending on its concentration, on lipid peroxidation was examined in an iron-supported and reconstituted enzymatic system. In the presence of NADPH-cytochrome P450 reductase and NADPH, Fe(3+)-PPi or Fe(3+)-ADP, though not reducible in the absence of EDTA, was markedly reduced with increasing concentration of EDTA. Lipid peroxidation, in the reconstituted system containing negatively charged liposomes, showed the maximal rate at 0.5 molar ratio of EDTA/iron, but no peroxidation occurred in positively charged liposomes, suggesting production of a positively charged iron complex as the prooxidant. Isotachophoresis indicated production of net-negative charge, EDTA-Fe(3+)-PPi complex, from Fe(3+)-PPi and EDTA at 1.1 ratio of EDTA/iron. The complex quenched Fe(2+)-PPi-supported lipid peroxidation. We suggest that EDTA-iron complexes of different charges are generated, depending on the amount of EDTA in the enzymatic system and, consequently, there is a switch between prooxidant and inhibitory effect at some critical ratio of EDTA/iron.

Animals↗

PubMed1994

Substrate specificity and subsite affinities of rabbit liver acid alpha-glucosidase.

The substrate specificity of rabbit liver acid alpha-glucosidase was investigated. The enzyme showed a wide specificity for various substrates, and hydrolyzed alpha-glucans such as glycogen and soluble starch. The k0 values (s-1) for maltose, kojibiose, nigerose, isomaltose, phenyl alpha-glucoside, panose, phenyl alpha-maltoside, soluble starch, beta-limit dextrin, amylopectin, shellfish glycogen, and rabbit liver glycogen were estimated to be 94.8, 18.8, 143, 3.6, 11.8, 27.8, 115, 99.2, 155, 83.5, 126, and 108, and the Km values (concentration of non-reducing terminal) for these substrates were 2.1, 1.8, 7.5, 36, 5.4, 1.9, 1.2, 0.90, 9.1, 1.0, 16, and 13 mM, respectively. Isomaltose and phenyl alpha-glucoside were unfavorable as substrates. The acid alpha-glucosidase is characterized by a relatively high activity toward glycogen. The k0 values (s-1) for maltotriose, -tetraose, -pentaose, -hexaose, -heptaose, and -octaose, and maltodextrin (n = 17) were 140, 140, 131, 132, 134, 132, and 74.3, and the Km values, 2.1, 1.8, 1.9, 3.4, 5.0, 4.9, 4.9 and 2.6 mM, respectively. Based on the rate parameters for the series of maltooligosaccharides, the subsite affinities (Ais) in the active site were evaluated as 0.54 (A1), 5.34 (A2), and 0.34 (A3) kcal/mol for subsites 1, 2, and 3, respectively. These three subsites were considered to be predominantly responsible for the binding of substrates to the active site.

Animals↗

PubMed1994

A microplate assay for sialidase activity using plant lectin binding to N-acetyllactosamine.

This paper presents a sensitive assay for sialidase activity based on the specific binding of lecting to N-acetyllactosamine. The substrate used for sialidase assay is fetuin (30-100 ng/50 microliters) with sialylated oligosaccharides, which was then coated on a 96-well microtiterplate. After removing sialic acids from the terminal positions of the glycoconjugate glycans by sialidase, it was subjected to biotin-labeled lectin (Ricinus communis agglutinin 120), which binds specifically to N-acetyllactosamine. This was followed by the addition of a peroxidase conjugated avidin-biotin complex. The amount of bound peroxidase was determined by a colorimetric assay. The sensitivity was enhanced 1000- to 10,000-fold compared to the colorimetric assay using a synthetic substrate such as 2-O-(p-nitrophenyl)-N-acetyl-alpha-D-neuraminic acid (PNPN). In the established method, only very small amounts of substrate and sialidase were required; therefore, it can be applied to the quantitative assay of some sialidases from Vibrio cholerae, streptococcus, the influenza virus and rat liver.

Amino Sugars↗

PubMed1994

Intraventricular changes in the beta-adrenoceptor-adenylate cyclase system of the rat heart with the progress of monocrotaline-induced right ventricular hypertrophy.

We investigated the changes in the membranous beta-adrenoceptor-adenylate cyclase system in the right ventricle, left ventricle and interventricular septum during the progress of monocrotaline-induced right ventricular hypertrophy and failure. The beta-adrenoceptor density was decreased in hypertrophied right ventricle 2 to 4 weeks after treatment. When the rats showed symptoms of right ventricular failure 4 weeks after treatment, the beta-adrenoceptor density was decreased in the interventricular septum. Both basal and forskolin-stimulated adenylate cyclase activities were decreased in the right ventricle at 3 and 4 weeks, and in the interventricular septum at 4 weeks, after treatment, which indicates that the catalytic activity of adenylate cyclase is reduced. Changes in isoproterenol plus Gpp (NH) p- or sodium fluoride-stimulated adenylate cyclase activity were generally similar to those in basal activity. These data indicate that a chamber-specific decrease in beta-adrenoceptor density begins in the early stages of right ventricular hypertrophy, and that beta-adrenoceptor density and adenylate cyclase activity in the interventricular septum are decreased in the advanced stages of heart failure in monocrotaline-treated rats.

5'-Nucleotidase↗

PubMed1994

[A case of muscle metastasis of renal cell carcinoma treated by local resection and tensor fascia lata myocutaneous flaps].

A 44-year-old male with a little finger tip-sized tumor palpable on the left epigastric wall and a left renal tumor detected on computerized tomography (CT) was referred to this hospital in June 1991. Nephrectomy was performed in July 1991 under the diagnosis of a left renal tumor. Histologically, the tumor was a renal cell carcinoma, grade 2, clear and granular cell type. The tumor in the left abdominal wall was not extracted. As a tumor also developed in the scapular tunica muscularis, tumors in the left musculus rectus abdominis and the scapular tunica muscularis were extracted to the extent possible in July of 1992. Histologically, these tumors were metastatic clear cell carcinomas. The tumor in the left musculus rectus abdominis recurred and another was palpable in the left lateral femur. In August of 1993, the tumors in the left musculus vastus lateralis and the left musculus abdominis were extracted together with the tunica muscularis, and the defective region on the abdominal wall was closed with a left musculus tensor fascia lata flap. No evidence of recurrence has been observed to date.

Adult↗

PubMed1994

[Evaluation of medicinal lymph node dissection in advanced gastric cancer].

In order to improve the results of surgical treatment in advanced gastric cancer, we performed preoperative targeted chemotherapy for metastatic lymph nodes. The solution which contained aclarubicin adsorbed on activated carbon was submucously injected around gastric tumor under endoscopic observation 2-7 days prior to the operation. We termed this method medicinal lymph node dissection (MLD). Our standard surgical treatment (SST) for gastric cancer consists of gastrectomy and extended lymph node dissection (N1 and N2 lymph nodes). Patients of curative resection with histologically positive lymph node metastasis were enrolled, as the subjects. We compared the cumulative survival rate in 47 patients treated with SST+MLD (MLD group) with that in 125 patients treated with SST only (control group). Five year survival rates in the MLD and control groups were 60% and 48%, respectively. The MLD group showed significantly higher survival rate in patients with N3, N4 and infrapyloric lymph node metastasis. A significant difference of the survival rate suggests the efficacy of SST+MLD against micrometastasis in N3 and para-aortic lymph nodes. The SST+MLD therapy is recommended to the advanced gastric cancer, especially in the lower third of the stomach.

Aclarubicin↗

PubMed1994

[A new index of acceleration plethysmogram and its clinical physiological evaluation].

The purposes of the present study were to examine a new index of acceleratingly plethysmogram (APG) and to discuss the possibility to apply the APG index. One hundred sixty-three subjects voluntarily participated in the present study. The mean values (n = 10) of individual coefficient of variance were 7.22% in wave height B, 8.26% in the total area of the lower part under the base line, and 7.28% in a new APG index. The coefficient of variance in the APG index calculated from the previous method (18.67%) was larger than that of the present study. We recognized the significantly polynomial relationship between the new APG index and types of APG. Further, the value of new APG index remarkably increased when the index was beyond 50. There were significant differences in age, blood pressure, rate of body fat, blood glucose, total cholesterol, HDL cholesterol, and index of arteriosclerosis between above 50 and below 50 in the new APG index. These results suggest that the present APG index is adequate about about the individual reproducibility, and it has the possibility to apply as an index of arteriosclerosis.

Adult↗

PubMed1994

[Effects of combination chemotherapy using 5-FU, leucovorin, and CDDP (FLP therapy) for noncurative resected or recurrent stomach cancer in outpatients].

We performed combination chemotherapy consisting of 5-FU, leucovorin, and CDDP (FLP therapy) against noncurative resected or recurrent stomach cancer in outpatients as of August 1991. Seventeen outpatients patients underwent FLP therapy until February 1993. Therapeutic responses, survival time after the operation or recurrence, rate at home, and the improvement of performance status (PS) were studied. The response rate was 54.5%, median survival time was 410 days, the rate at home was 75.5 +/- 14.7%, and the rate of improvement of PS was 82.4%. Toxicities were observed in 70.6%. Thrombocytopenia must be followed carefully, but it was encountered in only a few patients. FLP therapy for advanced or recurrent stomach cancer in outpatients was expected to improve the QOL.

Adult↗

PubMed1994

[A case of myelodysplastic syndrome with pericarditis due to atypical Mycobacterium].

A 28-year-old woman with high fever and cough was admitted because of an abnormal shadow on the chest X-ray film. Mycobacterium kansasii was detected by sputum culture. The complete blood cell count disclosed pancytopenia and the myelogram showed slight hypoplasia and abnormality of the cell morphology. We diagnosed her disease as atypical mycobacteriosis and myelodysplastic syndrome. We began medical therapy with antituberculous drugs against Mycobacterium kansassi, and the sputum culture became negative. She was discharged after 4 months, but cardiothoracic ratio (CTR) increased gradually and pericardial effusion was detected by echocardiogram during follow-up. She was admitted again. We did not perform exploratory puncture, because the pericardial effusion did not increase for 6 months after admission and she had no complaints. We continued the antituberculous drugs, and CTR and the pericardial effusion decreased during follow-up. We considered the diagnosis in this case to be pericarditis due to Mycobacterium kansasii.

Adult↗

PubMed1993

Re-evaluation of solid-phase adsorption and desorption techniques for isolation of trace organic pollutants from chlorinated water.

Amberlite XAD resin and activated carbon columns were tested for their abilities to concentrate trace organic pollutants in chlorinated water. Both XAD-2 and XAD-7 resin columns (20 ml) were capable of adsorbing about 30% of total organic halogen (TOX) present in 20 l of drinking water (pH 7) containing about 100 micrograms/l of TOX, whereas the carbon column (10 ml) adsorbed over 90% of TOX. The adsorption capacity of XAD-7 resin was found to be strongly dependent on the solution pH, as compared with those of XAD-2 and carbon adsorbents. Soxhlet and sonication extractions were also evaluated for their abilities to recover the adsorbed organics from the adsorbents, by measurements of TOX, chromatographable compounds and mutagenicity in the eluates. Soxhlet extraction gave higher recoveries than sonication, as measured with the above indices, but these differences were generally small (ca. 20%), with exception of the carbon extracts. The XAD-2 and XAD-7 extracts of drinking water also showed about 3-4 times higher mutagenic activity than the carbon extracts.

Acrylic Resins↗