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Y Takeda

Publications and source records attributed to Y Takeda.

At least 559 records · Page 31Linked to original sources
PubMed1995

Voltage-dependence of Ca2+ agonist effect of YC-170 on cardiac L-type Ca2+ channels.

1. We investigated the voltage-dependence of the agonist actions of YC-170, a dihydropyridine (DHP) derivative, on cardiac L-type Ca2+ channels in rabbit ventricular cells, using the patch clamp technique. The characteristics of YC-170 were compared with those of other DHP Ca2+ agonists (Bay K 8644, CGP 28392). Ca2+ channel activities were elicited by depolarizing pulses to 0 mV from a holding potential (HP) of either -80 mV or -40 mV. 2. YC-170 (10 microM) increased Ca2+ channel activities when HP was set at -80 mV. However, decreasing HP to -40 mV abolished the agonist action. The agonist effect of Bay K 8644 (1 microM) on Ca2+ channels was elicited to the same extent at either HP. CGP 28392 (10 microM) also increased Ca2+ channel activities at both HPs, but its agonist effect was significantly larger at an HP of -80 mV than at -40 mV. 3. All of the three DHP Ca2+agonists prolonged open times of Ca2+ channels, but the prolongation did not correspond to the voltage-dependence of Ca2+ agonist effects of the three DHPs. 4. YC-170 markedly reduced the closed time of the Ca2+ channel when the HP was at -80 mV, but prolonged it at HP of -40 mV. Bay K 8644 reduced closed times at an HP of -80 mV. At an HP of -40 mV, Bay K 8644 slightly reduced closed times. CGP 28392 reduced closed times at an HP of -80 mV and prolonged those at an HP of -40 mV. Thus the voltage-dependence of the agonist effects of these agents was in good agreement with the voltage-dependence of changes in closed times of Ca2+ channel. 5. Two mechanisms may be involved in the agonist action of YC-170; a prolongation of open times, and a reduction of closed times of Ca2+ channels, i.e. an increase in reopening. The former mechanism is not dependent on Hp and the latter mechanism is highly dependent on HP. Thus, the voltage-dependence of the agonist action may be attributed to the voltage-dependence of their enhancing effect on reopening of Ca2+ channels.

3-Pyridinecarboxylic acid, 1,4-dihydro-2,6-dimethy↗
PubMed1995

Emergence of tetracycline resistance due to a multiple drug resistance plasmid in Vibrio cholerae O139.

Of the 173 clinical strains of Vibrio cholerae O139 isolated from India, Bangladesh, and Thailand tested, six strains from India were resistant to tetracycline, ampicillin, chloramphenicol, kanamycin, and gentamicin. These six strains harbored a self-transmissible plasmid that mediated resistance to tetracycline, ampicillin, chloramphenicol, kanamycin, gentamicin, sulfamethoxazole, trimethoprim, and O/129. The multiple drug resistance plasmids were 200 kb in size and belonged to the incompatibility group C. Although a majority of the O139 strains (94.8%) were highly resistant to streptomycin, sulfamethoxazole, trimethoprim, and O/129, the tetracycline-susceptible strains so far tested were plasmid-negative. The data suggest the existence of two distinct multiple antimicrobial agent resistance (MAR) patterns in V. cholerae O139.

Ampicillin↗
PubMed1995

Detection of urovirulence factors in Escherichia coli by multiplex polymerase chain reaction.

Primers to amplify the genes encoding the virulence factors of uropathogenic Escherichia coli, such as pilus associated with pyelonephritis (pap), haemolysin (hly), aerobactin (aer) and cytotoxic necrotizing factor 1 (cnf1) genes, were designed. The above primers along with previously reported primers for S fimbriae (sfa) and afimbrial adhesin I (afaI) genes were combined to develop a multiplex polymerase chain reaction (PCR) for detection of the respective virulence factors and for the identification of uropathogenic E. coli. The multiplex PCR to detect pap, sfa, afaI, hly, aer and cnf1 genes was highly specific and the sensitivity was found to be about 5 x 10(3) colony forming units of E. coli per ml. A total of 194 E. coli strains isolated from patients with simple acute cystitis were examined by the multiplex PCR and the results were in complete agreement with that obtained by DNA colony hybridization test. The multiplex PCR developed was, therefore, concluded to be a useful, sensitive and rapid assay system to identify uropathogenic E. coli.

Base Sequence↗
PubMed1995

[Distribution of the genes of streptococcal pyrogenic exotoxin among clinical isolates of Streptococcus pyogenes from the pharynx].

The distribution of the genes of streptococcal pyrogenic exotoxin (speA, B and C) among the 400 clinical isolates of Streptococcus pyogenes from Japanese pharnyx was detected by the PCR method (Nihonrinsho 50: 326, 1992). Sixty, 399 and 303 isolates were positive for the speA, B and C genes, respectively. However, only one isolate had none of these genes. Several isolates possessed two or three genes, i.e., both speB & C, speA & B or speA, B & C were found in 258, 30 and 30 isolates, respectively. No isolate possessing both speA & C without speB was found in this study. We concluded that the PCR method is much more useful for the epidemiological study on streptococcal pyrogenic exotoxins (SPE) of S. pyogenes isolates because of specificity, rapidity and sensitivity of this method compared with the conventional SPE identification method.

Exotoxins↗
PubMed1995

Survey of in vitro susceptibilities of Vibrio cholerae O1 and O139 to antimicrobial agents.

Vibrio cholerae O139 (173 strains) and O1 (221 strains) were tested for their in vitro susceptibilities to 39 antimicrobial agents. Both O139 and O1 strains were highly susceptible to azithromycin, cephems, minocycline, penems, and newer fluoroquinolones. O139 strains (94.8%), O1 Indian El Tor strains (97%), and Bangladeshi El Tor strains (50%) were highly resistant to streptomycin, sulfamethoxazole, and trimethoprim and moderately resistant to chloramphenicol and furazolidone, in sharp contrast to O1 Peruvian El Tor and O1 classical strains. Some Bangladeshi El Tor strains (43.3%) showed tetracycline resistance as well.

Anti-Bacterial Agents↗
PubMed1995

Evaluation of DNA probes for specific detection of Vibrio cholerae O139 Bengal.

Two DNA probes, 2R1 and 2R3, prepared from a region in the chromosome specific for the lipopolysaccharide O side chains of Vibrio cholerae O139 (M.K. Waldor and J.J. Mekalanos, Lancet 343:1366, 1994) were examined for their specificity and sensitivity. Both probes did not hybridize with any strain of V. cholerae belonging to serogroups other than O139 and to any of the other species examined belonging to the family Vibrionaceae. Among the 126 strains of V. cholerae O139 examined, probe 2R1 hybridized with 125 strains while probe 2R3 hybridized with all 126 strains. Both probes were found to be highly specific and sensitive and can be used for the specific identification of V. cholerae O139.

Bacteriological Techniques↗
PubMed1995

Effect of T-kinin on microvascular permeability and its modulation by peptidases in rat airways.

T-kinin (Ile-Ser-bradykinin), the product of T-kininogen, has been found in rat plasma during systemic inflammation, but the effect of this kinin on airway inflammatory response is unknown. We examined the effect of T-kinin on vascular permeability in airways of anesthetized rats in vivo by using photometric measurement of the extravasated Evans blue. Intravenous injection of T-kinin (0.1-10 mumol/kg) increased dye extravasation in a dose-dependent manner, with 134% for trachea and 117% for bronchi by 1 mumol/kg. Pretreatment with bradykinin B2-receptor antagonist Hoe-140 (100 nmol/kg), but not the B1-receptor antagonist des-Arg9-Leu8-bradykinin (5 mg/kg), abolished plasma extravasation evoked by T-kinin (1 mumol/kg). NK1 tachykinin-receptor antagonist CP-99994 (4 mg/kg) did not affect T-kinin-induced vascular leakage. Pretreatment with captopril (2.5 mg/kg), angiotensin-converting enzyme inhibitor, potentiated T-kinin (100 nmol/kg)-induced plasma extravasation, whereas phosphoramidon (2.5 mg/kg), a neutral endopeptidase inhibitor, had no effect. We conclude that T-kinin produces airway vascular extravasation via stimulation of B2 receptors. The effect is modulated by endogenous angiotensin-converting enzyme and is not mediated via activation of sensory nerve.

Amino Acid Sequence↗
PubMed1995

Production of aldosterone in isolated rat blood vessels.

Angiotensin I (Ang I), Ang II, angiotensinogen, and renin are formed locally in the vasculature. We undertook this study to determine whether the rat mesenteric artery produces aldosterone and to investigate the effects of adrenalectomy, an angiotensin-converting enzyme inhibitor, Ang II, or potassium on aldosterone production in vascular tissue. Isolated rat mesenteric arteries were perfused with Krebs-Ringer solution for 4 hours. The perfusate was collected and chromatographed in a reversed-phase high-performance liquid chromatographic (HPLC) system. The fraction corresponding to synthetic aldosterone was collected and analyzed by mass spectrometry. The aldosterone concentration in the perfusate from the adrenalectomized rats and rats treated with an angiotensin-converting enzyme inhibitor was measured using radioimmunoassay after HPLC separation. The mass spectra of synthetic aldosterone and aldosterone isolated from the perfusate of rat mesenteric arteries were identical. Aldosterone production in the mesenteric arteries of adrenalectomized rats was increased and of rats treated with an angiotensin-converting enzyme inhibitor was reduced compared with that of controls. Ang II (1.9 x 10(10) mol/L) and potassium (6.0 mmol/L) increased aldosterone production in mesenteric arteries. This study shows that the rat mesenteric artery produces aldosterone and that the intravascular renin-angiotensin-aldosterone system may contribute to vascular tone.

Adrenalectomy↗
PubMed1995

Effects of an endothelin receptor antagonist in rats with cyclosporine-induced hypertension.

Cyclosporine, a potent immunosuppressant, is associated with the development of hypertension and nephrotoxicity. We have previously shown that endothelin release from the arteries is increased in rats with cyclosporine-induced hypertension. We conducted the present study to determine whether the specific endothelin type A (ETA) receptor antagonist FR 139317 prevents cyclosporine-induced hypertension and whether cyclosporine increases ETA receptor mRNA in blood vessels. Cyclosporine (25 mg/kg per day) given for 4 weeks increased blood pressure from 98 +/- 12 to 156 +/- 14 mm Hg; this increase was blunted by coadministration of 10 mg/kg per day FR 139317 (ie, blood pressure was 138 +/- 14 mm Hg) in Wistar-Kyoto rats. Cyclosporine induced greater vasoconstrictor responses to norepinephrine and angiotensin II in isolated mesenteric arteries. FR 139317 normalized the vasoconstrictor responses to angiotensin II and norepinephrine. Cyclosporine (25 mg/kg per day) given for 4 weeks increased ETA receptor mRNA expression in the rat aorta and mesenteric artery (170% and 176%, respectively). Little change was observed in ETB receptor mRNA. These results indicate that cyclosporine may increase blood pressure by increasing not only endothelin production but also ETA receptor in the vasculature. The specific ETA receptor antagonist FR 139317 may prevent the hypertension induced by cyclosporine.

Angiotensin II↗
PubMed1995

Enantioselective biotransformation of 1-isopropylnaphthalene in rabbits.

1-Isopropylnaphthalene (1) was administered orally to rabbits and the following eight metabolites, 2-(1-naphthyl)-2-propanol (7), 2-(1-naphthyl)-1-propanol (8: R/S = 83:17), 2-(1-naphthyl)-1,2-propanediol (9:R/S = 40:60), 4-isopropyl-1,2-naphthoquinone (10), 4-isopropyl-1-naphthol (11), 4-isopropyl-2-naphthol (12), 5-isopropyl-2-naphthol (13), and 2-(1-naphthyl)propanoic acid (14') as its methyl ester (14: R/S = 52:48), were isolated from urine. Among them, three metabolites (8, 9, and 14), possessing an asymmetric carbon atom in the molecule, were formed enantioselectively and five metabolites (7, 10, 11, 12, and 13) were formed regioselectively. The presumed metabolic pathways of 1-isopropylnaphthalene (1) in rabbits leading to these metabolites are discussed.

Administration, Oral↗
PubMed1995

Alangionosides G-M: glycosides of megastigmane derivatives from the leaves of Alangium premnifolium.

Phytochemical investigation of the 1-BuOH-soluble fraction of the MeOH extract of Alangium premnifolium resulted in the isolation of ten megastigmane glycosides, of which, two, (6R,9R)-3-oxo-alpha-ionol apiofuranosylglucopyranoside and roseoside with (6S,9R)-blumeol A as an aglycone were known. The structures of the eight new compounds were determined by spectroscopic methods.

Cyclohexanes↗
PubMed1995

Septic pulmonary emboli secondary to pyogenic liver abscess in a diabetic patient.

A 70-year-old woman with poorly controlled diabetes mellitus was admitted because of persistent remittent fever. Soon a liver abscess was detected as the cause of the fever by ultrasonography, and antibiotic therapy was started. However, suddenly serious dyspnea with chest and back pain developed. The morbid condition was definitely diagnosed as septic pulmonary emboli (SPE) with pulmonary perfusion scan. It should be recognized that liver abscess can be a latent focus of systemic metastatic complications such as SPE, and not only early detection but also prompt appropriate drainage of liver abscesses is essential.

Aged↗
PubMed1995

Y-shaped lower bilateral incisors. A previously undescribed oral malformation.

A case of Y-shaped lower bilateral central incisors found in an 18-year-old Japanese man is reported. Each of the central incisors had an abnormally high cusp located at the labial surface. The cause of this malformation of the lower central incisors is obscure, but we suspect that it was due to hyperplasia of the labial surface of the central lobe of the incisor during tooth development.

Adolescent↗
PubMed1995

[Detection of bacterial protein toxins by a bead-ELISA].

A highly sensitive bead-enzyme-linked immunosorbent assay to detect bacterial protein toxins was developed. Fab' of anti-toxin IgG was conjugated with horseradish peroxidase by the maleimide method and tetramethylbenzidine was used as a substrate. As the solid phase, a 6.5 mm diameter polystyrene bead was used and this was coated with the anti-toxin IgG. The sensitivities of the bead-ELISA for various bacterial protein toxins were as follows: less than 40 pg/ml for cholera enterotoxin (CT), less than 20 pg/ml for VT1 and less than 6 pg/ml for VT2 of enterohemorrhagic Escherichia coli. The bead ELISA was evaluated for direct detection of CT from stool specimens of patients with acute secretory diarrhea. Of the 75 stool samples examined, 59 yielded biochemically and serologically confirmed strains of Vibrio cholerae O1. The bead ELISA was positive for CT in stool supernatants in 50 (84.7%) of the 59 samples from which V. cholerae O1 was isolated. In addition, the bead ELISA was positive for three stool specimens which were negative by culture. These data indicate that the bead ELISA is a sensitive and simple method for direct detection of CT in nonsterile stool samples.

Acute Disease↗
PubMed1995

[Morphologic analysis of blood cells].

Accompanying hematology laboratory automation, the frequency of morphological observation of blood cells tends to decrease. Although 5-part differentials are performed by automated systems, counting of abnormal cells such as immature cells or leukemia cells still must be performed manually using smears. In the automated hematology laboratories, technicians more frequently find abnormal cells than before. Therefore, poor microscopic observation of blood cells markedly affects the diagnosis. Continuous training of the technologist is mandatory. Also, preparation of smear samples is important, i.e, well prepared slides must be stained properly with an appropriate dye. Technicians must be familiar with staining technology together with the knowledge of the characteristics of several staining methods. On the other hand, the technician's ability to differentiate white blood cells depends on the instructor's knowledge. This makes quality control and the standardization of differentials difficult. Still the problems must be solved under the cooperation of the various societies concerned.

Automation↗
PubMed1995

[The efficacy of transarterial immuno-embolization therapy in patients with unresectable hepatocellular carcinoma].

We devised a new therapeutic modality for multiple hepatocellular carcinoma (HCC) consisting of transarterial immuno-embolization (TIE) using OK-432 and fibrinogen, and applied the treatment to 22 patients with advanced HCC who had been insensitive to TAE, and 21 patients who had no treatment. Nineteen patients had a high AFP level of more than 200 ng/ml. The serum AFP level decreased in 15 patients after TIE, and in 7 patients the AFP level decreased to less than 30%. Furthermore, a marked reduction in tumor size was observed in 69% after TIE. We report 61% 1-year, and 3-year survival rate for cases who had been insensitive to TAE, and 86% 2-year survival rate for those who selected TIE as the first choice. A high fever of more than 38 degrees C occurred in all cases, and hypotension less than 80 mmHg was observed in 42% patients. No deterioration of liver function and no disturbance of the coagulation-fibrinolysis system due to TIE except in one patient with liver failure after TIE.

Carcinoma, Hepatocellular↗
PubMed1995

[Ischemic hepatitis due to anthracycline-induced cardiac insufficiency in a patient with acute myelocytic leukemia (M0)].

A 25 year-old woman diagnosed as acute myelocytic leukemia (M0) suffered a fourth relapse in February 1992 at which time she already had anthracycline-induced cardiac dysfunction. Although remission was induced by low dose cytosine arabinoside and etoposide combined with pirarubicin, she developed acute heart failure followed by extreme elevation of transaminases level and DIC. Abdominal echography and CT revealed small round lesions in the liver. We diagnosed this episode as ischemic hepatitis because of the following clinical findings; serological markers of virus hepatitis were negative, hypotension and reduced blood flow to the liver were seen, and both transaminases and LDH were markedly elevated. Dobutamin and oxygen inhalation were started, her liver function returned to almost normal levels 8 days later.

Adult↗