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Biomedical subjects

T Hirata

Publications and source records attributed to T Hirata.

At least 415 records · Page 23Linked to original sources
PubMed1987

The interaction of pancuronium and vecuronium with cardiac muscarinic receptors.

The interaction of vecuronium, a monoquaternary analogue of pancuronium, with the cardiac muscarinic receptors in canine hearts was investigated in vitro by [3H] QNB binding assay and compared with that of pancuronium. Both pancuronium and vecuronium, which are nicotinic antagonists of competitive types, inhibited the binding of [3H] QNB to cardiac muscarinic receptors with values of IC50 of 5.41 X 10(-7) mol/l and 3.97 X 10(-6) mol/l respectively. According to the Kd and Bmax values on the Scatchard plot, pancuronium, while not influencing the number of receptors, had a 3-fold greater inhibitory effect than vecuronium on the affinity of the muscarinic receptors. The KI values of vecuronium and pancuronium showed that pancuronium had a 7.3-fold greater affinity with the receptors than vecuronium. We concluded that vecuronium had a direct inhibitory action on the binding of [3H] QNB to the canine heart muscarinic receptors, but this action was much weaker than pancuronium.

Animals↗
PubMed1987

Clinical use of CA 125 and its combination assay with other tumor marker in patients with ovarian carcinoma.

The serum levels of CA 125 and CA 19-9 were determined by an immunoradiometric assay employing the monoclonal antibody OC 125 and anti-CA 19-9 antibody in 88 patients with ovarian carcinoma. When a cut-off value of CA 125 was set below 35 U/ml in the control group, serum elevated levels of CA 125 were found in 86.7% of the patients with surgically demonstrable ovarian serous cystadenocarcinoma, in 100% (4/4 cases) of clear-cell carcinoma, in 50% (2/4 cases) of endometrioid carcinoma, in 100% (5/5 cases) of undifferentiated carcinoma, and in 80% of the recurrent cases. Using a cut-off value of 37 U/ml, serum elevated levels of CA 19-9 were detected in 68.2% of mucinous cystadenocarcinoma, in 28.9% of serous cystadenocarcinoma, in 75% (3/4 cases) of metastatic ovarian carcinoma, and in 37.5% of the recurrent cases. A statistical analysis of the combination assay using CA 125, CA 19-9, tissue polypeptide antigen (TPA), immunosuppressive acidic protein (IAP), ferritin and CEA was carried out by multivariate method (discriminatory analysis) in 45 patients with ovarian carcinoma and 50 healthy subjects. As a result before treatment, positive rates of a single tumor marker were 79.7% with CA 125, 42.7% with CA-19-9, 73.1% with IAP, 61.7% with TPA, 64.3% with ferritin and 25.4% with CEA, respectively. A combination assay of these markers was useful for detecting identification of ovarian carcinoma, by which it gave a higher accuracy of ovarian cancer detection.

Adenocarcinoma↗
PubMed1987

Aminothiazolylglycyl derivatives of carbacephems. I. Synthesis and antibacterial activity of novel carbacephems with substituted aminothiazolyl groups.

A series of new carbacephem compounds which have substituted aminothiazolylglycyl side chain have been prepared starting from corresponding carbacephems with aminothiazolylmethoxyimino group. Among them, the compound having 3,4-dihydroxybenzoyl group showed very sharp activity against Pseudomonas aeruginosa. Moreover, the optical resolution of alpha carbon of aminothiazolylglycyl moiety was carried out through preparation of optically active side chain and the (S)-isomer (KT-4380) was found to be the most active against Pseudomonas sp. as well as other Gram-negative strains.

Anti-Bacterial Agents↗
PubMed1987

Aminothiazolylglycyl derivatives of carbacephem antibiotics. II. Synthesis and antibacterial activity of novel aminothiazolyl cephem compounds with hydroxypyridone moiety.

The synthesis and antimicrobial activity of novel carbacephem antibiotics which have amido moiety of (S)-aminothiazolylglycyl side chain are described. Among them, the compound having 5-hydroxy-4-pyridon-2-carboxyl group (KT-4697) showed exceptionally strong activity against Pseudomonas aeruginosa as well as Gram-negative bacteria. A cephalosporin with this acyl group namely KT-4788 with methylpyridiniumthiomethyl group at C-3 was found to be the most active against Gram-positive and Gram-negative strains including P. aeruginosa.

Catechol O-Methyltransferase↗
PubMed1987

[Clinical experience of the newly developed ultrasound lithotripter].

At present, to perform percutaneous nephrolithotomy (PNL), the ultrasound lithotripter (US) is most widely used, permitting simultaneous breakup of a calculus and suction of fragments. Recently, we have used the OLYMPUS LUS (oscillation frequency 23 kHz, maximum amplitude 60 microns) in 24 cases of renal calculi (including 6 staghorn and 5 multiple), 4 cases of ureteral calculi and 2 cases of reno-ureteral calculi. Although the degree of breakability varied depending on the substance of the calculi, cystine calculi, generally deemed relatively hard, could also be fragmented. The calculi which were found in the ureter were all situated in the upper portion of the ureter. Direct access by the US probe was possible in 1 case, but in 5 other cases the electrohydraulic lithotripter (EHL) was applied first and larger fragments blasted back into the pelvis were broken up and suctioned with the US. Residual calculi were recognized in 4 cases of 6 staghorn calculi and 2 cases of 5 multiple calculi, all of which were found within calyces and were small enough to allow spontaneous passage. In all the other 24 cases, calculi were destructed and removed with the US. We consider that most renal and ureteral calculi can be broken up and suctioned with the US, virtually regardless of the kind of substance, as long as they are situated in the areas accessible by the US probe. The 60 micron amplitude hardly posed any risk of serious injury to the renal parenchyma, not to mention the pelvic mucosa.

Adult↗
PubMed1987

[Clinical experience of the newly developed electrohydraulic lithotripter].

The electrohydraulic lithotripter (EHL) is a calculus-breaking device used in percutaneous nephrolithotomy (PNL). The conventional EHL has a shortcoming in that its breakability decreases in the saline irrigation environment. The newly developed EHL (Lithotron EL-21 OLYMPUS) is designed to discharge optimum sparks during saline irrigation, without having to dilute the solution, thus providing greater convenience. We used the new EHL in 17 cases of renal calculi, 11 cases of ureteral calculi and 2 cases of reno-ureteral calculi, with a breakup efficiency of 96.7%. As a direct, incidental complication, perforation of the ureter occurred in one case of ureteral calculi (uneventful spontaneous recovery detected 3 days afterward). The new EHL has a breakup capability suitable for the PNL: the EHL provides a safe procedure, provided that one takes sufficient caution to the correct positioning of the probe against the target calculus when activating it. Since the probe shaft is flexible, permitting use with the flexible endoscope, the EHL is particularly effective in treating ureteral and renal calculi in cases where access by the rigid US probe is not feasible. One disadvantage of the EHL is that it lacks the fragment-collecting capability that the ultrasound lithotripter features.

Adolescent↗
PubMed1987

Functional heterogeneity of human monocytes--with a special reference to flow cytometric assays.

A large number of human mononuclear cells were simultaneously separated into fractions enriched in B cells, T cells, large granular lymphocytes (LGL) and monocytes by centrifugal elutriation. Lymphocyte populations were analyzed using monoclonal antibodies. In particular, highly enriched natural killer cells, Leu7+ cells, were collected in the intermediate fractions. Monocytes, which were identified as esterase positive cells, and Leu M3 cells were collected at higher counterflow rates and in the final fraction. The purity of monocytes in the final fraction was 81%. The oxidative metabolic activity (H2O2 production) and non-specific esterase activity of individual monocytes was estimated in the analysis of functional heterogeneity of monocytes using flow cytometry. 2',7'-dichlorofluorescein diacetate (DCFH-DA) and fluorescein diacetate (FDA) were used as indicators in the measurement of H2O2 generation and esterase activity. Intracellular generation of a fluorescence product (H2O2 Production; average percentage of fluorescence positive cells) of monocytes in the stimulation of phorbol myristate acetate (PMA, 100 ng/ml) was greater in larger than smaller cells. H2O2 production gradually increased from 6% and 25-38% and 60% in the intermediate and final fractions respectively. Furthermore, the average fluorescence intensity of the large monocyte population in the final fraction was 1.13-1.31 fold more active than that of the smaller cells. Thus, the functional heterogeneity of human monocytes was further confirmed in the assays of H2O2 production exposed to PMA and FDA hydrolysis using flow cytometry. Furthermore, the CCE system can isolate lymphocyte subsets and LGL.

Antigens, Surface↗
PubMed1986

Effect of a selective thrombin inhibitor MCI-9038 on fibrinolysis in vitro and in vivo.

The effect of a selective thrombin inhibitor, (2R, 4R)-4-methyl-1-[N2-[(3-methyl-1,2,3,4-tetrahydro-8-quinolinyl)sulfonyl]- L-arginyl]-2-piperidinecarboxylic acid (MCI-9038), on the fibrinolysis induced by t-PA and u-PA was studied in vitro and in vivo. MCI-9038 remarkably reduced the lysis time of the plasma clot generated by the addition of calcium chloride to the plasma at the concentration ranging from 0.01 to 0.3 microM. Heparin also reduced the plasma clot lysis time with a lower effect than MCI-9038. The fibrin crosslinkage in the plasma clot was inhibited by MCI-9038 or heparin. MCI-9038 potently inhibited the factor XIIIa generation from factor XIII by thrombin. The effect on the in vivo thrombolysis was studied on the arterial thrombosis generated by the endothelial cell injury of the rabbit carotid artery by acetic acid. t-PA dissolved the thrombi with the infusion at 0.96 mg/kg over 2 h without a significant activation of a systemic fibrinolysis. u-PA dissolved the thrombi with the infusion at 180,000 and 360,000 IU/kg over 2 h. At a dose of 0.48 mg/kg t-PA or 90,000 IU/kg u-PA, the thrombi were not dissolved, but the combined use of MCI-9038 at 1.2 mg/kg over 2 h effectively dissolved the thrombi. Thus, combination of MCI-9038 with plasminogen activators accelerated thrombolysis of an experimental thrombosis in rabbits.

Animals↗
PubMed1986

Expression of the transferrin receptor gene during the process of mononuclear phagocyte maturation.

The expression of transferrin receptors by blood monocytes, human alveolar macrophages, and in vitro matured macrophages was evaluated by immunofluorescence, radioligand binding, and Northern analysis, using the monoclonal anti-human transferrin receptor antibody OKT9, [125I]-labeled human transferrin and a [32P]-labeled human transferrin receptor cDNA probe, respectively. By immunofluorescence, the majority of alveolar macrophages expressed transferrin receptors (86 +/- 3%). The radioligand binding assay demonstrated the affinity constant (Ka) of the alveolar macrophage transferrin receptor was 4.4 +/- 0.7 X 10(8) M-1, and the number of receptors per cell was 4.4 +/- 1.2 X 10(4). In marked contrast, transferrin receptors were not present on the surface or in the cytoplasm of blood monocytes, the precursors of the alveolar macrophages. However, when monocytes were cultured in vitro and allowed to mature, greater than 80% expressed transferrin receptors by day 6, and the receptors could be detected by day 3. Consistent with these observations, a transferrin receptor mRNA with a molecular size of 4.9 kb was demonstrated in alveolar macrophages and in vitro matured macrophages but not in blood monocytes. Thus, although blood monocytes do not express the transferrin receptor gene, it is expressed by mature macrophages, an event that probably occurs relatively early in the process of monocyte differentiation to macrophages.

Adult↗
PubMed1986

Are beta-adrenergic receptors in ventricular muscles of carp heart (Cyprinus carpio) mostly the beta-2 type?

The positive inotropic effect of isoproterenol was quantified in the presence of several beta-adrenergic blocking agents in ventricular strips of carp heart. Isoproterenol had a concentration-dependent positive inotropic effect. The effect was markedly inhibited by propranolol and carteolol, but was extremely insensitive to atenolol. Practolol totally failed to alter the effect. These results indicated that the positive inotropic effect of isoproterenol may be mediated by mostly beta-2 adrenergic receptors in ventricular strips of carp heart.

Adrenergic beta-Antagonists↗
PubMed1986

Organ failures due to low cardiac output syndrome following open heart surgery.

During the period from August, 1977 to December, 1984, a total of 3003 patients who received open heart surgery were treated postoperatively at the ICU of National Cardiovascular Center. Low cardiac output syndrome (LOS) developed in 669 (22.3%) patients. Organ failures due to LOS were studied in these patients. Although the overall mortality of postoperative patients was 5.6% and improved to around 4% in the later years, death rate of patients with LOS was persistently high (22.8%) and showed no tendency to improve even in the latest years. Moreover, the clinical results of those LOS patients who developed organ failure were extremely poor; the mortality of patients with respiratory failure (RF) accounted for 36.8% and that of patients with other organ failure exceeded 50%. The incidence of impaired organs in LOS patients was 49.9% in RF, 29.9% in acute renal failure (ARF), 18.4% in hepatic failure (HF), 16.4% in disseminated intravascular coagulation (DIC), 15.5% in central nervous system failure (CNSF), and 11.1% in gastrointestinal bleeding (GIB). Pathophysiological mechanisms as well as the management of these major complications caused by LOS are also discussed. Some patients developed multiple organ failure (MOF). Plasma exchange (PE) was performed on 16 patients who developed MOF. Improvement of various organ functions was obtained and consequently three patients were successfully treated by means of PE. Removal of various substances toxic to organs, supplement of deficient substances and cessation of the vicious cycle produced by the interaction of impaired organs in patients with MOF are major roles of PE in the treatment of MOF.

Acute Kidney Injury↗
PubMed1986

[Effects of 4-(o-benzylphenoxy)-N-methylbutylamine hydrochloride (MCI-2016, bifemelane hydrochloride) on coagulation, fibrinolysis, hemolysis, hemorheological properties and platelet aggregation].

MCI-2016 showed little influence on coagulation (APTT) and fibrinolysis (plasma clot lysis activated by urokinase) at doses (concentrations) as high as 300 mg/kg, p.o. or 8.6 X 10(-4) M. Hemolytic action of MCI-2016 was only observed at the concentrations above 2 mM. The drug also showed no influence on blood glucose level (30-300 mg/kg, p.o.). Effects of MCI-2016 on hemorheological properties were studied either in vitro or ex vivo. Above the doses (concentrations) of 100 mg/kg, p.o. and 10 microM, MCI-2016 suppressed the mechanical hemolysis and accelerated the membrane filtration rate. These effects of MCI-2016 were superior to those of cinepazide, Ca-hopantenate, meclofenoxate and pentoxyfylline. MCI-2016 also inhibited platelet aggregation induced by collagen with the IC 50 of 35 to 60 microM (rabbit and human platelets). Secondary aggregations of ADP and epinephrine were also inhibited by MCI-2016. As for reference drugs, bencyclane showed inhibitory patterns similar to MCI-2016. Other drugs examined exhibited little effect. In summary, it may be suggested that MCI-2016 exhibits beneficial influences in the clinical fields of cerebrovascular diseases.

Animals↗
PubMed1986

[Effects of oral administration of UFT in unresectable gastric cancer with liver metastasis].

A 62-year-old male was admitted because of upper abdominal mass. Exploratory laparotomy revealed unresectable gastric cancer, liver metastases and swelling of regional lymph nodes. Histological examination showed papillotubular adenocarcinoma. After 6 months' postoperative administration of UFT at a daily dose of 600 mg, X-ray and endoscopic examination revealed remarkable improvement of the gastric cancer. Computed tomography and ultrasonography showed disappearance of the mass in the liver and a remarkable decrease in the size of paraaortic lymph nodes. The cancer marker, serum CEA also decreased from 5.2 ng/ml to 2.1 ng/ml. At present, the abdominal mass is not palpable and the patient is asymptomatic except for pigmentation and being followed up in the outpatient department. This case suggests the possibility that UFT may be effective for advanced gastric cancer with liver metastases.

Adenocarcinoma↗