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Biomedical subjects

S Murata

Publications and source records attributed to S Murata.

At least 253 records · Page 14Linked to original sources
PubMed1986

Isolation and identification of uridine(5')-diphospho(1)-2,3-diacetamido-2,3-dideoxy-alpha-D- glucopyra nuronic acid from Pseudomonas aeruginosa P1-III.

A new uridine nucleotide was isolated from Pseudomonas aeruginosa P1-III (Habs serotype 5). On the basis of 13C-n.m.r. and p.m.r. spectroscopy, mass spectrometry, i.r.-absorption spectroscopy and circular dichrometry, the structure of the new compound was unequivocally identified as uridine(5')-diphospho(1)-2,3-diacetamido-2,3-dideoxy-alpha-D-gl ucopyranuronic acid.

Chemical Phenomena↗
PubMed1986

No evidence for linkage between the loci for coagulation factor XIII-A and HLA.

The linkage analysis between the locus for coagulation factor XIII-A (F13A) and HLA region genes (HLA-A, -C, -B) was performed. In males, the maximum of lod scores between F13A and HLA was 0.33 at 0 = 0.30, and in females lod scores were negative at all values of 0. The results provided no evidence for close linkage between F13A and HLA genes.

Chromosome Mapping↗
PubMed1986

[An electromyographic study of the effect of synthetic motilin on gastric motility in dogs].

To clarify the effect of synthetic motilin on gastric motility, the electromyograms after the bolus injection of synthetic motilin in dogs were investigated. The results were summarized as follows: After the bolus injection of synthetic motilin, the discharge interval was shortened and the propagation velocity was accelerated. Therefore, synthetic motilin stimulated gastric muscle in dogs. The dose-response effect of synthetic motilin on discharge interval was observed. On propagation velocity, the dose-response effect was observed, too. Between motilin and secretin, competitive antagonistic action was observed on electromyographic study. On the occasion of the combined use of motilin and tetragastrin, additive effect was observed. After atropine injection, synthetic motilin stimulated gastric muscle. After vagotomy, synthetic motilin also stimulated gastric muscle. After feeding, it was appeared that synthetic motilin did not stimulated gastric muscle.

Animals↗
PubMed1986

[New additional operation in the prevention of gastric stasis after selective gastric vagotomy with antrectomy].

The new additional operation for the prevention of the gastric stasis after the selective gastric vagotomy with antrectomy (SV + A) was performed. Our additional operative procedure was followed: After selective gastric vagotomy and antrectomy, gastroduodenostomy was anastomosed at acute angle with the longitudinalis of the stomach. Then, both lesser and greater omentum were incised outside of the gastric vessels. After these procedure, posterior wall sided to lesser curvature was fixed with the edge of the hepatogastric ligament and posterior wall sided to greater curvature was fixed with the retroperitoneum inferior to the pancreas by several sutures. The outcome of these treatments of the additional operation on SV + A enabled to shorten the duration of drainage of gastric juice, as well as smooth intake. By fluoroscopic examination one month after operation, gastric stasis was observed on SV + A due to the contrast medium stored in the ptotic corpus, whereas, in the case of SV + A with our additional operation, smooth gastric emptying was observed without any stasis of the contrast medium, because the corpus was placed upper from the anastomosis portion. In conclusion, our additional operation to SV + A was able to perform easy and safely, and was observed the effective prevention of gastric stasis.

Duodenal Ulcer↗
PubMed1986

Therapeutic effect of SF-2103A, a novel carbapenem antibiotic, in combination with cefotaxime, cefoperazone and other cephalosporins.

Combinations of SF-2103A with cefotaxime, cefoperazone or cefazolin showed synergistic efficacy at a wide range of combination ratios against experimental infection in mice due to Proteus vulgaris GN76/C-1, producing type Ic cephalosporinase, Escherichia coli No. 29/36 RGN823, producing type IIIa (TEM-2) penicillinase and E. coli GN206, producing type Ib cephalosporinase. These effects by SF-2103A were greater than those seen with sulbactam. The in vitro and in vivo synergistic activities were roughly correlated. Potent in vivo activity of SF-2103A was related to good pharmacokinetic properties, with blood half-life of 30 minutes and urinary recovery of 55.2% after parenteral administration to rats. Furthermore, SF-2103A was stable to rat kidney homogenate. The high stability of SF-2103A in aqueous and biological media was correlated with the sulfonate group at C-3.

Animals↗
PubMed1986

[Evaluation of a tumor-associated antigen CA 15-3 in the sera of patients with breast cancer].

Serum levels of CA 15-3 were determined in normal women and patients with breast cancer and other diseases. The serum concentration of normal subjects was 9.8 +/- 4.4 units/ml (mean +/- S.D., n = 97). The patients with primary and recurrent breast cancer had significantly higher levels of CA 15-3, their values being 23.1 +/- 59.6 (n = 47) and 127.6 +/- 179.7 (n = 32) units/ml, respectively. When the value of 20 units/ml was used as the cutoff for the normal value, the positive rates were 4%, 26% and 75% in normal women and breast cancer patients primary and recurrent, respectively. No increased levels were found in the sera of patients with benign breast diseases or with gastrointestinal, thyroid, lung and other cancers. The elevated levels of CA 15-3 decreased after successful therapy both in primary and recurrent breast cancer patients, while there was no change in nonresponders. The measurement of serum CA 15-3 would be useful for monitoring the therapy and for detection of the recurrence of breast cancer.

Adolescent↗
PubMed1986

Pharmacokinetics of doxorubicin, (2"R)-4'-O-tetrahydropyranyl-adriamycin and aclarubicin.

The following paragraphs summarize the properties of ADR, THP and ACR in terms of their pharmacokinetics. The blood level of anthracyclines shows a three-phase function of decline: alpha, beta and gamma phases. Compared with other classes of anticancer agents, the anthracyclines are characterized by an extremely short T1/2(alpha) and an extremely long T1/2(gamma). These characteristics reflect the facts that anthracyclines are rapidly transferred to the tissues and that they are retained for a long time in the body. In comparison with ADR, the T1/2(alpha) of THP is relatively short and T1/2(alpha, beta and gamma) of ACR are also short. Anthracyclines show large values for K12 and K13, transfer rate constants of the drug from the blood to the tissues, and small values for K21 and K31 transfer rate constants of the drug from the tissues to the blood. This means that these drugs are rapidly transferred to the tissues, from which they are then slowly released. The order of magnitude of K12 and K13 was THP greater than ACR greater than ADR. The order for K21 and K31 was ACR greater than THP greater than ADR. Anthracyclines are also characterized by small distribution volumes (V1) in the blood circulation, and very large distribution volumes (V2 and V3) in the tissue compartments. The order of magnitude for V2 and V3 was THP greater than ADR greater than ACR. Anthracyclines achieved high concentrations in such thoracic and abdominal organs such as lung, heart, thymus, liver, kidney, spleen and digestive tract. ADR showed the highest levels in liver and kidney, while THP and ACR showed their highest concentrations in lung and spleen. A decrease in the drug concentration in various organs is slow in the case of ADR, while rapid in the cases of THP and ACR. Most of the distributed drug is the unchanged form with ADR, whereas metabolites are common with ACR. THP is partially converted to ADR in liver. Anthracyclines were usually excreted over a long period of time at a high rate in the bile and at a low rate in the urine. Orally-administered ACR showed considerably good absorption from the digestive tract. The metabolism of anthracyclines was carried out in vivo and resulted in the formation of bioactive glycoside metabolites and inactive aglycone metabolites.(ABSTRACT TRUNCATED AT 400 WORDS)

Aclarubicin↗
PubMed1986

The dissociation between the plasma levels of aminopeptidases A and B in spontaneously hypertensive rats.

We performed a longitudinal study for 20 weeks on spontaneously hypertensive rats (SHR) and Wistar-Kyoto rats (WKR) to determine the relationship between peptide metabolism and the age-dependent increase in blood pressure. In both SHR and WKR, the plasma level of aminopeptidase A (AP-A) clearly showed an age-dependent decrease. The plasma level of aminopeptidase B paralleled that of AP-A in WKR, but such an age-dependency was not observed in SHR, thus showing a dissociation between the two aminopeptidases. With age in both strains, the level of angiotensin-converting enzyme tended to decrease, while that of kallikrein activity tended to increase. In addition to these findings, a multivariate study testing the relationship of blood pressure to these enzyme activities, as well as to plasma levels of angiotensin I and renin activity, suggested abnormalities in the networks of proteolytic enzymes and in the peptide metabolism surrounding the renin-angiotensin system in SHR. These abnormalities may play some important roles in pathophysiological mechanisms of hypertension in SHR.

Aging↗
PubMed1986

Cardiovascular effects of the new positive inotropic agent denopamine with special reference to species difference and the effect on failing heart.

Cardiovascular effects of (-)-(R)-1-(p-hydroxyphenyl)-2-[(3,4-dimethoxyphenethyl)amino]ethanol (denopamine, TA-064) were investigated in various experimental animals. An intravenous bolus injection of denopamine dose-dependently increased the contractile force or the maximum rate of rise of left ventricular pressure (LV dp/dtmax in cynomolgus monkeys, miniature pigs, cats and rats. In these animals, the doses of denopamine which increased the contractile force by 30% of the control (ED30) were found to be 2-3 micrograms/kg. On the other hand, ED30 values for dl-isoprenaline ranged from 0.005 to 0.04 micrograms/kg. Thus, the potency of denopamine for increasing the contractility was approximately 1/60-1/300 that of dl-isoprenaline. It is noteworthy that the positive inotropic effect of denopamine was more pronounced than the positive chronotropic effect compared with those of isoprenaline, as estimated at ED30 for positive inotropy. In general, denopamine produced little effect on the blood pressure, and only a slight increase or an increasing tendency was observed in all of these animals. An intravenous continuous infusion of denopamine to monkeys or pigs produced qualitatively similar cardiovascular effects to those following intravenous bolus injection. When examined with monkeys, the positive inotropic effect and plasma levels of denopamine were closely related. Denopamine increased cardiac output, and reduced total peripheral resistance in pigs and dogs. In dogs, common carotid, superior mesenteric and femoral arterial blood flow were increased concomitant with the increase in cardiac output, while the vascular resistance of the corresponding vascular bed was reduced. Denopamine had no significant influence on central venous pressure in monkeys and pulmonary arterial pressure in dogs.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1986

[Comparative studies on the pharmacokinetics between THP and adriamycin in the same patients].

The pharmacokinetic properties of THP and ADM were comparatively studied in the same patients with various cancers. The concentration of ADM in either plasma or blood cells was higher than that of THP from 5 minutes to 24 hours after administration. The metabolites of ADM such as aglycones were detected in plasma until 3 hours after administration, but these were never detected in blood cells. By contrast, the metabolites of THP were detected until 24 hours after administration. These results suggested that THP was metabolized in tissues and excreted into urine and that the rate of metabolism and excretion of THP was faster than that of ADM. Distribution volumes (V1, V2, and V3) of THP were larger than those of ADM. The above results strongly suggested that THP would be easily transferred into the tissues, but that in the case of slower transferring tissues with lower K13 values, ADM rather than THP would be easily transferred to the tissues. These pharmacokinetic properties suggested that the toxicity of THP might be diminished compared with that of ADM.

Aged↗
PubMed1985

1-Azacycloalkyl-1,4-benzodiazepin-2-ones with antianxiety-antidepressant actions.

A series of 1-azacycloalkyl-1,4-benzodiazepin-2-ones were synthesized from 1-azacycloalkyl-2-benzoylanilines and corresponding imines and then evaluated for their central nervous system activities. Pharmacological data showed that some of these compounds have potent antidepressant properties, as assessed by their antagonism of tetrabenzine (TBZ) induced ptosis and their inhibition of [3H]norepinephrine uptake into rat brain synaptosomes, as well as their moderate antianxiety properties of preventing of pentylenetetrazol (PTZ) convulsion, suppressing conflict behavior, and displacing potential for [3H]diazepam binding. Introduction of a halogen substituent at position 7 of the 1,4-benzodiazepine ring lengthened the anti-PTZ effects, although the peak effect was slightly reduced and clearly enhanced the anti-PTZ and anticonflict properties. Introduction of Cl to the ortho position of the phenyl ring at position 5 greatly reduced the antidepressant properties. The secondary amine function of the azacyclic ring at position 1 was essential for the production of the antidepressant properties. Of these new series, 7-fluoro-5-(2-fluorophenyl)-1,3-dihydro-1-(4-piperidinyl)-2H-1,4-benzodi azepin-2 -one has the potential to become a useful antidepressant drug with a moderate antianxiety property.

Animals↗
PubMed1985

Stereochemistry of biopterin cofactor and facile methods for the determination of the stereochemistry of a biologically active 5,6,7,8-tetrahydropterin.

The structure of (-)-tetrahydrobiopterin, the cofactor for phenylalanine, tyrosine, and tryptophan hydroxylases, was determined as (6R, 1'R, 2'S)-6-(1',2'-dihydroxypropyl)-5,6,7,8-tetrahydropterin by X-ray crystallographic analysis. The CD spectra of (-)-tetrahydrobiopterin exhibits a negative Cotton effect at 290-240 nm in pH 3.2 solution. The relationship of the negative Cotton effect and the 6R configuration was supported by the application of CD analysis with 2-methyltetrahydronaphthalene as a model compound. The stereochemistries at the C(6) position of various biologically active 6-substituted tetrahydropterins were determined from the CD spectra. The relative configuration of two asymmetric centers, C(6), and C(1'), was determined by HPLC analysis on a strong cation exchange column.

Biopterins↗
PubMed1985

Relationship between enkephalinase inhibition of thiorphan in vivo and its analgesic activity.

The relationship between enkephalinase inhibition by thiorphan in vivo and analgesic activity in nociceptive tests was studied. The analgesic activity of thiorphan in various nociceptive tests was compared with that of a narcotic analgesic, morphine and antipyretic analgesic, antipyrine. Tail-flick test revealed that thiorphan applied intracerebroventricularly (i.c.v.) or intraperitoneally (i.p.) in rats markedly potentiated the analgesic activity of [D-Ala2, Met5]-enkephalin administered i.c.v. The amount of thiorphan in the mouse brain and the fragments of Met-enkephalin degraded by brain homogenate were assayed after intraperitoneal administration of 300 mg/kg thiorphan. The concentration of thiorphan in the brain arised to 18.2 +/- 2.4 nmol/g brain 30 min after intraperitoneal administration of thiorphan and then it quickly disappeared from the brain. As to the fragments of Met-enkephalin degraded by brain homogenate after i.p. administration of thiorphan, the concentration of tyrosine and tyrosyl-glycine (Tyr-Gly) was the same as that of the vehicle control, whereas only the amount of tyrosyl-glycyl-glycine (Tyr-Gly-Gly) decreased to 21.5% of the control value after 30 min, and then it recovered to 75% after 180 min. Thus, thiorphan inhibited enkephalinase activity alone demonstrating selective activity. Thiorphan at doses of 30-300 mg/kg demonstrated analgesic activity in the nociceptive tests of acetic acid writhing, hot-plate and tail-flick, whereas it did not have any activity in the tail-pinch test. Morphine showed analgesic activity in the four nociceptive tests employed. Antipyrine showed analgesic activity in three nociceptive tests but not in the tail-flick test. The dose response curves for morphine and antipyrine were parallel. The slope of the dose response curve for thiorphan, however, was shallower than those for two reference analgesics used. The role of main enkephalin degrading enzymes in the brain was discussed with respect to the analgesic action of thiorphan and its concentration in the brain.

Amino Acids, Sulfur↗