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Biomedical subjects

T Matsuda

Publications and source records attributed to T Matsuda.

At least 865 records · Page 48Linked to original sources
PubMed1993

Capnocytophaga sputigena bacteremia associated with acute leukemia.

During a three-year period, Capnocytophaga sputigena bacteremia occurred in three patients with acute leukemia receiving induction therapy on a hematology ward. Oral pathology such as periodontitis or severe mucositis was considered to be the most likely source of bacteremia. All three blood culture isolates were identified as that species by deoxyribonucleic acid (DNA) homology studies. Because of the phenotypical similarity of Capnocytophaga species, it is difficult to differentiate them by conventional bacteriological methods. All three isolates were susceptible to antibiotics active against most anaerobes. However, production of beta-lactamase was found in two isolates, one of which proved resistant to both piperacillin and ceftazidime. Therefore, the empiric use of imipenem or clindamycin may be justified in febrile granulocytopenic patients with cancer who develop significant oral lesions.

Acute Disease↗
PubMed1993

Effect of inhaled procaterol on cough receptor sensitivity to capsaicin in patients with asthma or chronic bronchitis and in normal subjects.

BACKGROUND: To evaluate the effect of inhaled beta 2 adrenergic agonists on the sensitivity of airway cough receptors, the effect of inhaled procaterol on cough induced by aerosolised capsaicin, a stimulant of C fibres, was studied in patients with asthma or chronic bronchitis and in normal subjects. METHOD: Eleven patients with asthma and 10 with chronic bronchitis and 14 normal subjects participated. Increasing concentrations of capsaicin solution were inhaled for 15 seconds by tidal breathing through the mouth at one minute intervals until five or more coughs were elicited, before and 30 minutes after inhalation of 20 micrograms procaterol or placebo (freon gas alone) through a metered dose inhaler. Cough threshold was defined as the lowest concentration of capsaicin that elicited five or more coughs. To evaluate the bronchodilator effect of procaterol and the bronchoconstrictor effect of inhaled capsaicin, forced expiratory volume in one second (FEV1) was measured before and one minute after a capsaicin provocation test. This test was carried out both before and 30 minutes after treatment with procaterol or placebo. RESULTS: The geometric mean value of cough threshold to capsaicin was significantly increased by procaterol and placebo in both groups of patients but not in the control subjects. The increment in the cough threshold was not significantly different between the treatments with procaterol and placebo in each group. FEV1 was significantly increased by procaterol but not by placebo in all three groups. CONCLUSIONS: Inhaled procaterol has no effect on airway cough receptor sensitivity to capsaicin. The attenuation of the cough sensitivity seen after inhalation of procaterol in patients with asthma and bronchitis may result from tachyphylaxis to capsaicin.

Administration, Inhalation↗
PubMed1993

Acute stroke in cats: comparison of dynamic susceptibility-contrast MR imaging with T2- and diffusion-weighted MR imaging.

PURPOSE: To evaluate the hemodynamics of acute stroke in cats by means of dynamic susceptibility-contrast magnetic resonance (MR) imaging compared with standard T2- and diffusion-weighted MR imaging. MATERIALS AND METHODS: Unilateral permanent occlusion of the middle cerebral artery was performed in 18 cats. MR imaging was performed with each method 2 hours (n = 2), 6 hours (n = 10), and 24 hours (n = 11) after occlusion. RESULTS: At every time point, dynamic MR images clearly showed ischemic regions of steady-state signal hyperintensity and areas of less dynamic decrease in signal intensity that corresponded closely to those seen on diffusion-weighted MR images. T2-weighted MR images did not reveal regions of high signal intensity 2 hours after occlusion. The measurements of relative blood volume obtained with the dynamic method were significantly lower in steady-state hyperintense ischemic areas of the affected side than those in the contralateral normal areas at 6 and 24 hours (P < .001). CONCLUSION: This dynamic method can advance the time of detection of early ischemia in comparison with T2-weighted MR imaging and provides functional information about hemodynamics not provided by other methods of MR imaging.

Acute Disease↗
PubMed1993

Functional role of Ca(2+)-activated K+ channels in resting state of carotid arteries from SHR.

Carotid arteries from spontaneously hypertensive rats (SHR) exhibited an active tone when exposed to a physiological salt solution; that is, the tension decreased when nifedipine was added. To determine the possible role of Ca(2+)-activated K+ (KCa) channels in the resting state of these arteries, the effects of agents that interact with these channels on tension and 86Rb efflux were compared in endothelium-denuded strips of carotid arteries from SHR and normotensive Wistar-Kyoto rats (WKY). The addition of charybdotoxin, a blocker of high-conductance KCa channels, to the resting strips produced a concentration-dependent contraction in SHR but not in WKY. In resting strips preloaded with 86Rb, the basal 86Rb efflux rate constant was significantly greater in SHR than in WKY. The addition of nifedipine to the resting strips decreased the basal 86Rb efflux rate constant only in SHR. The effect of nifedipine on tension and 86Rb efflux in 25.9 mM K(+)-contracted strips of WKY was comparable to the effect of this blocker in the resting strips of SHR. The basal 45Ca influx in resting strips of SHR was significantly increased when compared with WKY, and this increase in SHR was abolished by nifedipine. These results suggest that the transmembrane Ca2+ influx via L-type voltage-dependent Ca2+ channels was significantly increased in the resting state of carotid arteries from SHR and that the KCa channels were highly activated.

Animals↗
PubMed1993

Reduction of reperfusion injury by recombinant human superoxide dismutase administered intravenously just prior to reperfusion.

The reduction of reperfusion injury by intravenous administration of recombinant human superoxide dismutase (r-hSOD) was evaluated in a dog model. Two hours of left anterior coronary artery clamping were followed by 30 min of partial reperfusion and 30 min of full reperfusion. In the SOD group, r-hSOD (100,000 U/kg) was given intravenously 5 min before reperfusion. Measured left ventricular (LV) segments were classified thermographically by temperature drop into central (> or = 2 degrees C) and marginal (< 2 degrees C) areas. The regional LV functions were evaluated by percentages of both segmental (%SS) and active (%AS) shortening. In the central area, the %SS values after reperfusion were -9% in the control group and -3% in the SOD group (p < 0.05). The respective %AS values were 6 and 29% (p < 0.01). In the marginal area, both groups had %SS values of -3% and respective %AS values of 34 and 22% (all not significant) after reperfusion. In the central area, there was significantly better LV function recovery in the SOD group than in the control group.

Animals↗
PubMed1993

Changes in plasma levels of prothrombin fragment F 1 + 2 in cases of disseminated intravascular coagulation.

Plasma levels of prothrombin fragment F 1 + 2 (PTF) and thrombin-antithrombin III complex (TAT) were assayed in 86 cases of disseminated intravascular coagulation (DIC). A significant elevation of both parameters was observed in most cases of DIC, which suggested that the in vivo generation of thrombin is highly accelerated by the cleavage of the prothrombin molecule by factor Xa. On the contrary, no significant elevation of plasma levels of PTF was observed in cases of DIC with severe hepatic failure or fulminant hepatitis in spite of significant elevation of TAT. Plasma levels of PTF were directly proportional to those of TAT in 86 cases of DIC as a whole (r = 0.682, p < 0.001). The measurement of both parameters was considered to be useful to estimate the hemostatic activation in DIC.

Antithrombin III↗
PubMed1993

Three cases with different types of short-tailed spermatozoa.

Short-tailed spermatozoa were found in 3 men attending our subfertility clinic. Light microscopy revealed basically normal sperm heads, but a short tail was found in 90% or more of the spermatozoa. Scanning and transmission electron-microscopic examinations of the ejaculate revealed several types of short-tailed spermatozoa. In one case, the majority of the spermatozoa had a short, thick tail. In another case, all the spermatozoa were short-tailed, although two different types could be distinguished. As in the first case some spermatozoa were short- and thick-tailed, whereas others possessed an incomplete neck and middle piece, and a short, thick principal piece. In the third case, an elongated middle piece and short principal piece were found in almost all the short-tailed spermatozoa. Our electron-microscopic study revealed that the type of short-tailed spermatozoa was different in each patient.

Adult↗
PubMed1993

Effects of shock waves on the male reproductive system.

Although many reports concerning the effects of shock waves on the human body have been published, their effects on the male reproductive system are not well known. This report examines the effects of shock waves on human spermatozoa and rat testes. Semen samples were placed in water at 37 degrees C and 100, 200, 500, and 1,000 shock waves were applied. In proportion to an increasing number of shock waves, sperm motility and the percentage of viable sperm decreased, while the percentage of short-tailed sperm increased. In a second study 500 or 1,000 shock waves were applied to the testes of infant and adult male Wistar rats. Hematomas were observed macroscopically in the testes immediately after shock wave treatment. Light microscopy showed rupture of the basement membrane of the seminiferous tubules and outflow of spermatogenic cells. After 5 weeks, the treated testes appeared atrophic, with the absence of spermatogenic cells in the seminiferous tubules, except for Sertoli cells. Our data indicate that spermatozoa and the testis appear to be structurally damaged by shock waves.

Animals↗
PubMed1993

Hepatorenal reflex plays an important role in natriuresis after high-NaCl food intake in conscious dogs.

Responses of renal nerve activity and urinary Na+ and Cl- excretion were examined in chronically instrumented conscious dogs through feedings of boiled rice with or without NaCl. The boiled rice (20 g/kg body wt) without NaCl did not influence plasma Na+ and Cl- concentrations, renal nerve activity, or urinary Na+ excretion but decreased urinary Cl- excretion. On the other hand, boiled rice containing NaCl (0.4 g/kg body wt) increased plasma Na+ (+3.8 +/- 0.7 meq/l) and Cl- (+3.0 +/- 1.5 meq/l) concentrations, then decreased renal nerve activity by 61 +/- 4%, and increased urinary Na+ and Cl- excretions. In dogs with hepatic denervation, a decrease in renal nerve activity, which was observed in intact dogs in response to the high-NaCl food intake, was completely abolished along with significant attenuation of postprandial natriuresis. That is, only 9 +/- 5% of the loaded Na+ and 7 +/- 3% of the loaded Cl- were excreted during 4 consecutive hours in hepatic-denervated dogs, whereas 36 +/- 5% of the loaded Na+ and 36 +/- 4% of the loaded Cl- were excreted in intact dogs. In dogs with renal denervation, postprandial natriuresis was also attenuated. These results indicate that the high-NaCl food intake elicits a decrease in renal nerve activity, the decrease is predominantly mediated by the hepatic nerves, and the decrease in renal nerve activity plays an important role in augmentation of urinary Na+ and Cl- excretion. Thus, the hepatorenal reflex may play an important role in controlling extracellular fluid homeostasis during food intake.

Animals↗
PubMed1993

Aerosolized acetaldehyde induces histamine-mediated bronchoconstriction in asthmatics.

It has been reported that acetaldehyde may be a main factor of alcohol-induced bronchoconstriction in Japanese patients with asthma. The purpose of this study was to investigate the direct action of acetaldehyde on the airway in asthmatic and healthy nonasthmatic subjects. We investigated the bronchial response to inhalation of ascending doses (5, 10, 20, and 40 mg/ml) of acetaldehyde in nine asthmatic subjects, who were treated with placebo or terfenadine for 4 days in a double-blind, randomized, placebo-controlled, crossover fashion, and in nine age- and sex-matched healthy subjects. The bronchial responsiveness to inhaled methacholine was also measured in the same asthmatics on a separate day. Inhaled acetaldehyde caused marked (more than 20%) significant decrease in FEV1 in asthmatics after placebo, which was larger than that in asthmatics after terfenadine and in healthy subjects. There was no significant difference in the decrease in FEV1 between asthmatics treated with terfenadine and healthy subjects. There was a significant correlation between the methacholine and acetaldehyde concentrations producing a 20% fall in FEV1 in asthmatics. We conclude that acetaldehyde causes bronchoconstriction indirectly via histamine release in asthmatics, and that nonspecific bronchial hyperresponsiveness is a necessary precondition for the expression of acetaldehyde-produced bronchoconstriction.

Acetaldehyde↗
PubMed1993

Regulation of spontaneous acetylcholine release in the hypothalamic vasopressinergic supraoptic nucleus of a freely moving rat: a study by in vivo microdialysis.

We employed a brain microdialysis method to examine the possible regulation of spontaneous acetylcholine (ACh) release in the hypothalamic vasopressinergic supraoptic nucleus (SON) of rats. We monitored the basal ACh release in the SON-microdialysate. The addition of tetrodotoxin (10(-6) M) to the perfusate (saline containing 10(-4) M physostigmine) decreased the basal ACh release. A muscarinic receptor antagonist, atropine (non-selective) or pirenzepine (M1-selective), increased the basal ACh release in a concentration-dependent manner. The maximal increase occurred at 20-40 min after the start of the infusion of antagonists. The ED50 values for the stimulatory effects of atropine and pirenzepine were 9.4 x 10(-8) and approx. 10(-4) M, respectively. The effect of atropine (10(-6) M) was inhibited by simultaneous addition of the muscarinic agonist oxotremorine (10(-5) M). The results showed a negative feedback regulation of the spontaneous ACh release through the activation of muscarinic receptors in the SON. The weak effect of pirenzepine in increasing the ACh release, compared with atropine, suggests that ACh release in the nucleus is mainly regulated by the non-M1-muscarinic receptor subtype.

Acetylcholine↗
PubMed1993

Substance P injected into the hypothalamic supraoptic nucleus causes antidiuresis through the release of arginine-vasopressin in water-loaded and ethanol-anesthetized rats.

The effects of injection of substance P (SP) into the hypothalamic supraoptic vasopressinergic nucleus (SON) in water-loaded and ethanol-anesthetized rats were examined. Substance P and its analog [D-Pro2, D-Trp7,9]SP induced marked decreases in urine outflow, with a ED50 value of approx. 0.4 and 0.9 nmol, respectively. The antidiuresis of SP was inhibited by a prior injection of [D-Arg1, D-Trp7,9, Leu11]SP (spantide), an SP-receptor antagonist into the SON. After the injection of SP, urine osmotic pressure was increased by threefold, and the urine level of arginine-vasopressin (AVP) was elevated by 70-fold. The effects of SP and [D-Pro2, D-Trp7,9]SP were completely blocked by pretreatment with an intravenous injection of d(CH2)5-D-Tyr(Et)VAVP, an AVP (V1V2)-receptor antagonist. A prior injection of atropine, a muscarinic receptor antagonist, inhibited the effect of [D-Pro2, D-Trp7,9]SP, but not that of SP. The results suggest that SP, injected into the SON, causes antidiuresis through the release of AVP. A possible mechanism for the antidiureses induced by SP and [D-Pro2, D-Trp7,9]SP is discussed.

Anesthesia↗
PubMed1993

Effects of D-Ala2-D-Leu5-enkephalin, microinjected into the supraoptic and paraventricular nuclei, on urine outflow rate.

The effects of D-Ala2-D-Leu5-enkephalin (DADL, a delta-opioid agonist), microinjected directly into the hypothalamic supraoptic (SON) and paraventricular (PVN) nuclei, on urine outflow rate, urinary osmotic pressure, blood pressure, heart rate, respiratory rate and rectal temperature were investigated in water-loaded and ethanol-anesthetized rats. The microinjection of DADL into both the nuclei decreased urine outflow rate in a dose-dependent manner with an increase in urinary osmotic pressure, but did not change the other recorded parameters. The DADL-induced antidiuretic effect in the SON was inhibited by naloxone, but not by atropine, phenoxybenzamine, timolol nor a vasopressin antagonist, d(CH2)5-D-Tyr(Et)VAVP. The effect in the PVN was inhibited by naloxone, atropine, timolol and d(CH2)5-D-Tyr(Et)VAVP, but not by phenoxybenzamine. These results suggest that DADL causes antidiuretic effects mediated through opioid receptors in both the SON and PVN, and the underlying mechanisms are different between them. Involvement of delta-opioid receptors in the DADL-induced antidiureses was discussed.

Animals↗
PubMed1993

Microinjection of dynorphin into the supraoptic and paraventricular nuclei produces antidiuretic effects through vasopressin release.

The mechanisms for the antidiuretic effects of dynorphin (DYN), an endogenous kappa-agonist, microinjected into the hypothalamic supraoptic (SON) and paraventricular (PVN) nuclei were investigated. DYN decreased the urine outflow rate dose-dependently from 5 to 20 nmol in the SON and PVN, and it increased vasopressin release. Microinjection of des-Tyr-DYN (a non-opioid peptide) into the SON produced antidiuretic effects with similar potency to that of the DYN-induced effects. However, in the PVN, the effects of des-Tyr-DYN were very markedly weaker than those of DYN. The DYN-induced antidiureses in the SON were partially inhibited by phenoxybenzamine, timolol and atropine, but not by naloxone. Those in the PVN were partially inhibited by naloxone, timolol and atropine, but not by phenoxybenzamine. Synthetic specific kappa-agonists, U50, 488H and Tyr-Gly-Gly-Phe-Leu-Arg-Arg-Ile-Arg-Pro- Arg-Leu-Arg-Gly 5-aminopentylamide (DAKLI), microinjected into the PVN also produced antidiuretic effects in a dose-dependent manner. The order of antidiuretic potency was DAKLI > DYN > U50,488H, which was the same as that of kappa-receptor binding affinity. The DAKLI-induced antidiureses in the PVN were not inhibited by naloxone. These results suggested that DYN caused antidiureses by vasopressin release, through adrenergic and cholinergic mechanisms in the SON and PVN. Only the DYN-induced effects in the PVN were mediated, at least partially, through opioid receptors, perhaps the kappa-subtype.

3,4-Dichloro-N-methyl-N-(2-(1-pyrrolidinyl)-cycloh↗
PubMed1993

Failure of killed Corynebacterium parvum in induction of protection in C57BL/6 mice against Babesia rodhaini challenge infection.

We examined the survival rate of C57BL/6 mice challenged with Babesia rodhaini 21 days post-killed Corynebacterium parvum (KCP) inoculation in comparison with ICR mice. All KCP-inoculated ICR mice survived the challenge infection, while all KCP-inoculated C57BL/6 mice died. To account in part for the difference in protective effects of KCP, stimulatory effects of KCP on splenic phagocyte chemiluminescence (CL) response were investigated in C57BL/6 and ICR mice. The KCP-inoculated ICR mice exhibited significantly higher CL values than ICR mice without KCP inoculation. No significant difference in CL value was observed between C57BL/6 mice with and without KCP inoculation. These results taken together, the lack of resistance of the KCP-inoculated C57BL/6 mice to B. rodhaini infection may be attributed in part to small stimulatory effect of KCP on splenic phagocytes.

Animals↗
PubMed1993

Transient wheeze. Eosinophilic bronchobronchiolitis in acute eosinophilic pneumonia.

The clinicopathologic features of five patients with acute eosinophilic pneumonia who presented with transient wheeze as well as acute onset of high fever, severe hypoxemia, and diffuse pulmonary infiltrates are described. Eosinophilic pneumonia was diagnosed by bronchoalveolar lavage and transbronchial lung biopsy. The illness resolved rapidly with or without corticosteroid therapy. No relapse occurred. To characterize the transient wheeze, a transbronchoscopic bronchial biopsy and pulmonary function tests were performed. Specimens of bronchial wall revealed eosinophil infiltration into the bronchial mucosa. Pulmonary function tests demonstrated reduced diffusing capacity and small airway dysfunction. These findings suggested that eosinophil infiltration into the bronchial mucosa might temporarily cause transient wheeze, different from bronchial asthma, due to small airway dysfunction in acute eosinophilic pneumonia.

Acute Disease↗
PubMed1993

Correlation of nonspecific bronchial responsiveness to baseline pulmonary function in patients with asthma and sinobronchial syndrome.

To examine the relationship of nonspecific bronchial responsiveness to baseline pulmonary function, and to compare the reactivity in asthma and sinobronchitis, we measured the provocative concentration of methacholine, causing a 20% fall in forced expiratory volume in one second (PC20-FEV1) in 82 asthmatic patients, 54 patients with sinobronchial syndrome and 57 normal subjects. Log PC20-FEV1 was directly correlated to baseline pulmonary function. The strongest correlation was seen between log PC20-FEV1 and baseline FEV1 as a % of the predicted FEV1 (%FEV1), both in asthma (log PC20-FEV1 = 0.020 x %FEV1-1.988, r = 0.54, p < 0.01) and in sinobronchial syndrome (log PC20-FEV1 = 0.025 x %FEV1-1.233, r = 0.64, p < 0.01). From the regression equations, the mean value of PC20-FEV1 at 100% FEV1 was calculated as 1.02 and 18.5 mg/ml in asthmatic and sinobronchitic patients, respectively, and the value was 35.5 mg/ml in normal subjects. The PC20-FEV1 to %FEV1 relationship may be helpful to assess individually measured PC20-FEV1 values in patients with airway obstruction.

Adult↗