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Biomedical subjects

T Matsuda

Publications and source records attributed to T Matsuda.

At least 685 records · Page 38Linked to original sources
PubMed1995

Recombinant hirudin for the treatment of disseminated intravascular coagulation in patients with haematological malignancy.

The purpose of this pilot study was to determine the effect of recombinant hirudin (r-hirudin) on coagulopathy and the relationship between concentrations of thrombin-antithrombin III (ATIII) complex (TAT) and thrombin-hirudin complex (THC) in patients with disseminated intravascular coagulation (DIC). Five patients with haematological malignancy associated with DIC were studied. r-Hirudin was administered by continuous intravenous infusion at a dose of 0.005 mg/kg/h for 4-9 days to each patient. Fibrin/fibrinogen degradation products (FDP), D-dimer, TAT and plasmin-alpha 2 antiplasmin complex (PAP) concentrations decreased after treatment with r-hirudin in four patients studied. However, in one patient, serum creatinine increased to 1.7 mg/dl and aPTT was prolonged to 74.4s. Statistical analysis disclosed significant positive correlations between plasma concentrations of hirudin and THC, and between concentrations of THC and TAT. The concentrations of THC were much higher than those of TAT. In conclusion, these findings indicate that r-hirudin more strongly inhibited thrombin than did ATIII without heparin, and that administration of r-hirudin to renal insufficiency required individual adjustment of dosage. The present findings also suggest that r-hirudin can be considered a new agent for the treatment of DIC.

Acute Disease↗
PubMed1995

K+ channel-opening properties of a novel compound, NIP-121, in guinea pig myocardium as compared with those of cromakalim.

Myocardial effects of NIP-121, a novel compound with potent vasorelaxant activity, were examined in comparison with those of cromakalim in isolated tissue and cells from guinea pig hearts. NIP-121 and cromakalim concentration-dependently reduced the action potential duration (APD) of isolated papillary muscle; the effect was antagonized by glibenclamide. In isolated ventricular tissue, NIP-121 and cromakalim decreased the contractile force concentration dependently. In these two experiments, the potency of NIP-121 was approximately 20 times higher than that of cromakalim. The effects of NIP-121 and cromakalim on membrane currents were examined in voltage-clamped ventricular myocytes. NIP-121 (10(-6) M) and cromakalim (3 x 10(-5) M) increased the steady-state outward currents. The normal inwardly rectifying current-voltage relationship changed to a linear relationship that reversed at the K+ current reversal potential. The current activated by NIP-121 and cromakalim was inhibited either by glibenclamide or by increased intracellular ATP concentration. NIP-121, at this concentration, had little effect on the calcium current. Thus, NIP-121 was demonstrated to produce AP shortening and decrease in contractile force through activation of ATP-sensitive K+ currents in cardiac muscle, with a potency approximately 20 times higher than that of cromakalim.

Action Potentials↗
PubMed1995

Establishment and characterization of non-small cell lung cancer cell lines resistant to mitomycin C under aerobic conditions.

To elucidate the mechanisms of acquired resistance to mitomycin C (MMC) in non-small cell lung cancer (NSCLC), we established two MMC-resistant NSCLC sublines by continuous exposure to MMC, using PC-9 as a parent cell line. The sublines, PC-9/MC2 and PC-9/MC4, were 6.4- and 10-fold more resistant to MMC than their parent cell line, respectively, at the IC50 value as determined by MTT assay. They exhibited cross-resistance to EO9, but were not resistant to cisplatin, vindesine, etoposide, carboquone, or KW-2149, a novel MMC derivative. They were collaterally sensitive to adriamycin and menadione. Accumulation of the drug was decreased in the resistant sublines to about 60% of that in the parent cells. Cytosolic DT-diaphorase (DTD) activities were decreased to 13.5 +/- 3.2 in PC9/MC2 and 1.3 +/- 0.6 in PC-9/MC4 from 261.5 +/- 92.7 nmol/min/mg protein in the parent PC-9. NADH:cytochrome b5 reductase activities in both of the resistant cell lines were significantly decreased as compared to that in the parent cell line. Addition of dicumarol resulted in a two-fold increase in IC50 value in PC-9, whereas the IC50 value showed no change in PC-9/MC4. Moreover, dicumarol did not affect the sensitivities to KW-2149 but decreased the sensitivities to EO9 in both the parent and the resistant cell lines. Formation of an alkylating metabolite was significantly decreased in the resistant cells, in parallel to the degree of resistance. We concluded that deficient drug activation due to decreased DTD activity was important as a mechanism of resistance to MMC in PC-9, a relatively DTD-rich NSCLC cell line.

Aerobiosis↗
PubMed1995

Bronchial hyperresponsiveness and airway neutrophil accumulation induced by interleukin-8 and the effect of the thromboxane A2 antagonist S-1452 in guinea-pigs.

Interleukin-8 (IL-8) has been shown to be a chemotactic factor for neutrophils, T-lymphocytes and eosinophils, but it is unknown whether the IL-8-induced inflammatory cell accumulation into the airways can cause the bronchial hyperresponsiveness (BHR) characteristic of asthma. IL-8 at a dose of 0.5 or 5 micrograms/kg was administered intranasally to guinea-pigs twice a week for 3 weeks. One day after the last administration, animals were anesthetized and artificially ventilated through tracheal cannula and lateral pressure at the cannula (Pao) was measured as an overall index of airway responses to increasing concentrations of inhaled histamine (25, 50, 100, and 200 micrograms/ml). The IL-8 treatment significantly enhanced bronchial responsiveness to histamine in a dose-dependent manner (ANOVA P < 0.01). The provocative concentration of histamine causing a 100% increase in Pao (PC100) at a dose of 0.5 and 5 micrograms/kg of IL-8 was 68.1 (GSEM 1.12) and 35.6 (GSEM 1.25) micrograms/ml, respectively. The latter was significantly (P < 0.01) lower than that in control animals treated with PBS (93.3 [GSEM, 1.14] micrograms/ml). The IL-8 treatment also induced a significant influx of neutrophils, but not eosinophils, in bronchoalveolar lavage (BAL) fluid (18.3 +/- 8.8 and 30.6 +/- 8.3% in animals treated with 0.5 and 5 micrograms/kg, respectively, of IL-8 vs 3.6 +/- 0.7% in phosphate buffered saline-(PBS)-treated animals). Furthermore, we examined the effect of the thromboxane receptor antagonist S-1452 (0.01 or 0.1 mg/kg, i.p. 24 and 1 h before anesthesia) on this IL-8 induced BHR. S-1452 significantly inhibited the BHR dose-dependently (ANOVA P < 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

Administration, Intranasal↗
PubMed1995

Detection of the urine jet phenomenon using Doppler color flow mapping.

BACKGROUND: Ultrasonic Doppler color flow mapping was applied to detect urinary flow in this study. The purpose of the study was to provide fresh insight into urodynamic and functional studies of the kidney and ureter. METHODS: Ultrasonic Doppler color flow mapping was performed from the abdominal surface to detect the urine jet phenomenon from the ureteral orifice in 25 healthy men and four healthy boys. In the cases in which the jet phenomenon was observed, the maximum velocity, mean velocity, successive time and frequency were measured. In 23 of the 25 men, the measurement was performed under normal circumstances and during diuresis. RESULTS: In 23 (92%) of the 25 men and in three (75%) of the four boys, the urine jet phenomenon was clearly visualized under normal conditions. The measured maximum velocity, mean velocity, successive time and frequency on the left side under normal conditions for the men were 31.8 +/- 15.3 cm/sec, 20.0 +/- 10.2 cm/sec, 2.5 +/- 1.3 sec and 1.2 +/- 0.5/min, respectively. The magnitude of each of these parameters was smaller in the case of the boys. CONCLUSIONS: The detection of the jet phenomenon by Doppler color flow mapping is a promising new way of examining renal or ureteral function noninvasively.

Adult↗
PubMed1995

Increase of noradrenaline release in the hypothalamus of freely moving rat by postsynaptic 5-hydroxytryptamine1A receptor activation.

1. 5-Hydroxytryptamine (5-HT) plays a role in the regulation of noradrenergic neurones in the brain, but the precise mechanism of regulation of noradrenaline (NA) release by 5-HT1A receptors has not been defined. The present study describes the effect of a highly potent and selective 5-HT1A receptor agonist, 5-(3-[[(2S)-1,4-benzodioxan-2-ylmethyl)]amino]propoxy)-1,3-b enzodioxole HC1 (MKC-242), on NA release in the hypothalamus using microdialysis in the freely moving rat. 2. Subcutaneous injection of MKC-242 (0.5 mg kg-1) increased extracellular levels of NA and its metabolite, 3-methoxy-4-hydroxyphenylglycol, in the hypothalamus and hippocampus. 3. The 5-HT1A receptor agonists, 8-hydroxy-2-(di-n-propylamino) tetralin (8-OH-DPAT) (0.2 mg kg-1) and buspirone (3 mg kg-1) mimicked the effect of MKC-242 in increasing NA release in the hypothalamus. 4. The effects of MKC-242 and 8-OH-DPAT in the hypothalamus were antagonized by pretreatment with WAY100135 (10 mg kg-1), a silent 5-HT1A receptor antagonist. 5. Local administration of 8-OH-DPAT (10-100 microM), citalopram (1 microM), a 5-HT reuptake inhibitor, and MDL72222 (10 microM), a 5-HT3 receptor antagonist, into the hypothalamus, had no effect on NA release. 6. Intracerebroventricular injection with 5,7-dihydroxytryptamine caused a marked reduction in brain 5-HT content, but the treatment affected neither basal NA levels nor the MKC-242-induced increase in NA release. 7. The effect of MKC-242 in increasing NA release was not attenuated by repeated treatment with the drug (0.5 mg kg-1, once a day for 2 weeks). 8. The present results suggest that activation of postsynaptic 5-HT1A receptors increases NA release in the hypothalamus.

5,7-Dihydroxytryptamine↗
PubMed1995

Sustained negative inotropism mediated by alpha-adrenoceptors in adult mouse myocardia: developmental conversion from positive response in the neonate.

1. Inotropic responses to alpha-adrenoceptor stimulation and the effects of antagonists were examined in isolated ventricular preparations from neonatal and adult mice. 2. Phenylephrine, in the presence of propranolol, produced positive inotropic responses in neonates up to 1 week after birth, while it produced negative inotropic responses in mice older than 3 weeks. 3. Both positive and negative responses to phenylephrine in neonates and adults, respectively, were antagonized by prazosin, WB4101 (2-([2,6-dimethoxyphenoxyethyl]aminomethyl)-1,4-benzodioxane) and 5-methylurapidil, but not by atropine, yohimbine or chlorethylclonidine. 4. Noradrenaline (NA) produced positive inotropic responses both in the neonate and adult; the responses were observed in a lower concentration-range in the neonate than in the adult. WB4101 produced a significant leftward shift of the concentration-response curve for noradrenaline in adult preparations while only a slight rightward shift was observed in the neonate. 5. Our results demonstrate the presence of alpha-adrenoceptor-mediated inotropic responses in the mouse ventricular myocardia. The response to phenylephrine changes from a positive to a negative effect during postnatal development. The responses are mediated by alpha 1-adrenoceptors, and modulate the overall inotropic response to NA in the adult.

Adrenergic alpha-Agonists↗
PubMed1995

Haemostatic and fibrinolytic parameters in septic patients with leukopenia or leukocytosis.

Induction of leukocytopenia by cytotoxic drugs protects against the generalized Shwartzman reaction induced by endotoxin. To elucidate the relationship between leukocyte number and in haemostatic and fibrinolytic disturbances in human sepsis, we studied 32 septic patients with abnormal leukocyte counts. Twenty patients had sepsis in the setting of leukopenia after chemotherapy for haematological malignancies. Twelve patients with leukocytosis developed sepsis associated with benign disorders. Concentrations of thrombin-antithrombin III complex (TAT), plasminogen activator inhibitor-1 (PAI-1) and plasma thrombomodulin (TM) in the leukocytosis group of (12.0 +/- 11.0, 40.2 +/- 27.0 and 5.5 +/- 2.3 ng/ml, respectively) were significantly elevated compared to the leukopenia group of (3.8 +/- 2.3, 18.0 +/- 15.0 and 3.1 +/- 1.0 ng/ml, respectively) and controls (3.3 +/- 0.4, 10.5 +/- 5.3, 3.0 +/- 0.5 ng/ml, respectively). On the other hand, there were no significant differences in these values between leukopenia group and controls. Thus leucocytes may play important roles in thrombin generation, PAI-1 release and injury to endothelial cells.

Adult↗
PubMed1995

Effect of sympathectomy on inotropic responsiveness to alpha-adrenoceptor stimulation in developing mouse myocardia.

Effects of postnatal sympathectomy on inotropic responsiveness to alpha-adrenoceptor stimulation were examined in mouse myocardia to determine whether the developmental conversion of alpha-adrenoceptor-mediated inotropic responses from positive to negative is triggered by sympathetic innervation. Sympathectomy was performed chemically by consecutively administering 6-hydroxydopamine for 14 days after birth and confirmed by the absence of inotropic responses to tyramine. In newborn myocardia, phenylephrine, in the presence of propranolol, produced concentration-dependent positive inotropic responses. Three weeks after birth, phenylephrine, in the presence of propranolol, produced concentration-dependent negative inotropic responses, both in control and in sympathectomized myocardia; no difference was observed between the two groups of mice in the maximum decrease in contractile force produced by phenylephrine. The sensitivity (pD2 value) to phenylephrine was significantly higher in sympathectomized myocardia. In conclusion, sympathetic innervation of the mouse ventricular myocardium is not required for the developmental conversion of the alpha-adrenoceptor-mediated inotropic response from positive to negative.

Adrenergic alpha-Agonists↗
PubMed1995

Metabolic alterations in the neonate and infant brain during development: evaluation with proton MR spectroscopy.

PURPOSE: To evaluate the usefulness of hydrogen-1 magnetic resonance (MR) spectroscopy in the evaluation of the developing brain. MATERIALS AND METHODS: Localized MR spectra were obtained with an echo time of 272 msec from the brain of 78 neonates and infants aged 1 week to 100 months. All patients were retrospectively classified into three groups on the basis of neurologic development: abnormal (group 2, n = 21), normal despite minor neurologic signs (group 1, n = 23), and normal (group 0, n = 34). RESULTS: Seventeen patients in group 2 and eight patients in group 1 revealed abnormally low N-acetylaspartate (NAA)/choline or NAA/creatine ratios compared with those obtained in group 0. MR spectroscopy was slightly more useful in the differentiation of patients in groups 2 and 1 (chi 2 test, P < .005) than MR imaging (P < .01). CONCLUSION: H-1 MR spectroscopy provides prognostic information about the brain in healthy and neurologically damaged infants and augments the value of MR imaging.

Aspartic Acid↗
PubMed1995

Depressed sensitivity of the hepatoportal NaCl receptors in rats with carbon tetrachloride-induced liver cirrhosis.

In normal rats, the activity of the hepatoportal NaCl-sensitive afferent nerves is increased by portal injection of hypertonic NaCl. In the present article, we have found this effect to be markedly reduced in rats with CCl4-induced liver cirrhosis (CT rats). Liver tissue norepinephrine content, a marker of tissue innervation, was also decreased in the treated rats. Over the 12 wk CCl4-treatment period, no significant difference in Na balance was found between control and CT rats when both groups were given normal NaCl (0.45%) food. However, when both were given high NaCl (8%) food, the Na balance of CT rats was positive and greater than that of controls. These results indicate that the sensitivity of the hepatoportal NaCl receptors is decreased even when the degree of liver cirrhosis is slight. This mechanism plays an important role in maintaining Na balance during intake of high NaCl food.

Animals↗
PubMed1995

Intravenous injection of acetaldehyde but not ethanol induces histamine-mediated bronchoconstriction in guinea pigs.

Recently ethanol-induced bronchoconstriction associated with elevated serum levels of acetaldehyde and histamine was reported in Japanese asthmatic patients, but there is no investigation of the airway response to intravenous injection of acetaldehyde. We therefore performed a study in guinea pigs to test the hypothesis that intravenous injection of acetaldehyde has bronchospastic action via histamine release. At first, we investigated the airway response to increasing doses (8.0, 26.4, and 80 mg/ml) of injected ethanol or acetaldehyde in guinea pigs. Secondarily, increasing doses of acetaldehyde were injected in guinea pigs pretreated with an intraperitoneal injection of 20 mg/kg diphenhydramine or saline (control). Finally, injection of acetaldehyde was performed after intraperitoneal injection of 0.5 mg/kg atropine sulfate or saline (control). Injected acetaldehyde caused bronchoconstriction in a dose-dependent manner, but ethanol did not. The bronchoconstriction induced by injected acetaldehyde was completely prevented by pretreatment with diphenhydramine. Atropine had no preventing effect against the acetaldehyde-induced bronchoconstriction. In conclusion, intravenous injection of acetaldehyde causes bronchoconstriction via histamine release in guinea pigs.

Acetaldehyde↗
PubMed1995

Acute nonlymphocytic leukemia complicated by Garcin's syndrome.

A 15-year-old girl was diagnosed as having acute nonlymphocytic leukemia (ANLL, FAB M2) in January 1990 and achieved complete remission with chemotherapy. She was readmitted to our hospital with a hearing disturbance and hoarseness in October 1990. A suprapharyngeal tumor was found on cranial MRI, and bone marrow leukemic cells were slightly increased in number. Involvement of leukemic cells was proven by biopsy of the tumor. Therefore, we made a diagnosis of ANLL relapse with Garcin's syndrome. To our knowledge, this is the first reported case of leukemia complicated by Garcin's syndrome.

Adolescent↗
PubMed1995

Modulation of baroreceptor activity by nitric oxide and S-nitrosocysteine.

The goal of this study was to determine whether nitric oxide (NO) and the NO donor, S-nitrosocysteine (cysNO), modulate the activity of carotid sinus baroreceptors. Baroreceptor activity was recorded from the vascularly isolated carotid sinus in anesthetized rabbits. Baroreceptor activity decreased in a dose-dependent manner after injection of either NO or cysNO as constant pressure was maintained, and activity recovered spontaneously over time, within seconds to minutes. The baroreceptor pressure-activity relation was shifted significantly to the right by cysNO, with a profound suppression of activity at high pressure. Baroreceptor activity at 160 mm Hg averaged 76 +/- 8%, 60 +/- 6%, and 36 +/- 5% of the control maximum during exposure to 10(-4), 2 to 3 x 10(-4), and 10(-3) mol/L cysNO, respectively. The inhibition of activity by the L and D isomers of cysNO was equivalent and was blocked by reduced hemoglobin, suggesting that the effect was mediated by NO. The suppression of baroreceptor activity by cysNO was not related to vascular relaxation as measured by videomicrometer. Inhibition of soluble guanylate cyclase with methylene blue or 6-anilinoquinoline-5,8-quinone (LY83583, 10(-5) mol/L) did not attenuate and dibutyryl cGMP (10(-3) mol/L) did not mimic the suppression of baroreceptor activity by cysNO, suggesting a cGMP-independent mechanism. Activation of endogenous NO formation with thimerosal (10(-5) to 10(-4) mol/L) reduced maximum baroreceptor activity in five of eight experiments to 59 +/- 7% of the control maximum.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1995

Bronchodilator and bronchoprotective effects of cilostazol in humans in vivo.

Cilostazol is a selective orally active phosphodiesterase (PDE) III inhibitor. This study was conducted to evaluate whether inhibition of PDE subtype III can reduce bronchial responsiveness. We examined the effects of cilostazol on bronchial responsiveness to methacholine in eight normal subjects by a single-blinded, crossover study. Each subject received 200 mg of cilostazol or placebo in random order. The subjects underwent methacholine challenge test 3 h after administration of each drug on two occasions separated by 5 d or more. The geometric mean value of provocative concentration of methacholine causing a 20% fall in FEV1 (PC20-FEV1) and the mean value (+/- SEM) of maximum expiratory flow on partial flow-volume curve at isovolume of 40% FVC above residual volume (PEF40) after administration of cilostazol were 25.3 (geometric standard error of the mean [GSEM], 1.35) mg/ml and 3.78 +/- 0.31 L/s, which were significantly (p < 0.02 and p < 0.05) greater than those after the placebo administration (6.81 [GSEM, 1.42] mg/ml and 2.71 +/- 0.39 L/s). All subjects complained of mild to severe headache when cilostazol was given. These findings suggest that PDE III inhibitors such as cilostazol have bronchodilator and bronchoprotective effects in humans. Further studies regarding smaller oral dosing of or aerosol administration of cilostazol or the other PDE III inhibitors are needed to determine clinical usefulness.

3',5'-Cyclic-AMP Phosphodiesterases↗
PubMed1995

Repeated inhalation challenge with exogenous and endogenous histamine released by acetaldehyde inhalation in asthmatic patients.

We previously reported that inhaled acetaldehyde, a metabolite of ethanol and a main factor in alcohol-induced asthma, causes bronchoconstriction indirectly through endogenously released histamine in asthmatic subjects. No study has examined the difference between tachyphylaxis in response to endogenous as opposed to exogenous histamine. Therefore, we examined tachyphylaxis occurring in response to repeated inhalation of histamine or acetaldehyde in nine asthmatic subjects. The mean acetaldehyde concentration causing a 20% decrease in FEV1 increased significantly from 18.4 (geometric standard error of the mean (GSEM = 0.14) to 45.2 (GSEM = 0.14) mg/ml over a period of 1 h (p < 0.002), whereas the mean histamine concentrations causing a 20% decrease in FEV1 were identical. No correlations were observed between the change in bronchial responsiveness to each solution and the change in baseline FEV1. These results suggest that tachyphylaxis in response to histamine is observed only when the latter is released endogenously. We believe that this is the first report suggesting tachyphylaxis caused by endogenous histamine.

Acetaldehyde↗
PubMed1995

A randomized trial of E5510 versus aspirin in patients with transient ischemic attacks. The Japanese E5510 TIA study-1 (JETS-1) Group.

In a randomized double-blind trial, the Study Group compared the efficacy of E5510, a novel antiplatelet agent, and aspirin in preventing the recurrence of transient ischemic attacks (TIA). In total, 227 patients who suffered from TIA in the twelve weeks prior to the study were enrolled. They were randomly allocated to three treatment groups, ie, 71 patients in the E5510 4 mg group, 77 patients in the E5510 2 mg group, and 79 patients in the aspirin 324 mg group, and were treated for twelve to twenty-four weeks. The incidence of recurrent TIA or stroke was 21.5% in the aspirin group and was significantly lower in the E5510 groups, being 8.5% in the 4 mg group (P < 0.05) and 11.7% in the 2 mg group (P < 0.05). Adverse events were observed in 5 cases in the 4 mg group, in 8 cases in the 2 mg group, and in 10 cases in the aspirin group, but none of them were serious. Since safety was judged to be comparable among the three groups, E5510 appears to be an antiplatelet agent for the treatment of TIA with a clinical benefit over aspirin.

Aged↗