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Biomedical subjects

H Satoh

Publications and source records attributed to H Satoh.

At least 865 records · Page 48Linked to original sources
PubMed1984

Effects of sublingual isosorbide dinitrate on left ventricular performance during exercise in patients with myocardial infarction.

In order to investigate left ventricular performance during exercise in patients with myocardial infarction and evaluate the effects of sublingual isosorbide dinitrate (ISDN) on left ventricular performance, we performed a symptom-limited multigraded exercise test using a bicycle ergometer in supine position. Thirty-seven patients with myocardial infarction were evaluated in order to clarify the hemodynamic responses to exercise with and without sublingual ISDN. Patients were subdivided into 3 groups according to the level of pulmonary capillary pressure (PCP) and cardiac index (CI) at peak exercise as follows: Group I (14 patients); PCP less than 18 mmHg, CI greater than or equal to 5.0 or CI less than 5.0 L/min/m2, Group II (11 patients); PCP greater than or equal to 18 mmHg, CI greater than or equal to 5.0 L/min/m2, Group III (12 patients); PCP greater than or equal to 18 mmHg, CI less than 5.0 L/min/m2. Exercise capacity without ISDN (control study) was correlated with left ventricular performance during exercise. Although left ventricular performance in patients who complained of dyspnea or chest pain at peak exercise was worse than those who complained of leg fatigue, we could not predict hemodynamics during exercise from the level of hemodynamic parameters at rest in each patient. Determinant factors of left ventricular performance during exercise were age, previous history of myocardial infarction, the severity of coronary artery lesion and the extent of left ventricular wall motion abnormality which was estimated by left ventriculogram as an index of infarct size. After sublingual ISDN (ISDN study), exercise capacity was improved. No patient terminated exercise because of chest pain and only one did because of dyspnea.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1984

Effects of nicorandil on the membrane currents of rabbit sino-atrial node cells.

The effects of nicorandil (SG-75) (3-500 micrograms/ml) on the membrane potential and currents of the rabbit sino-atrial node were studied using the voltage clamp technique. Low concentrations of nicorandil (3-10 micrograms/ml) increased the action potential duration (APD) and depolarized the maximum diastolic potential (DMP), but higher concentrations had no such effect and even decreased APD and tended to hyperpolarize MDP. Regardless of these effects, nicorandil decreased the heart rate concentration-dependently. On the current systems of the sino-atrial node, 3 micrograms/ml of nicorandil decreased the outward current (ik), but concentrations of over 10 micrograms/ml increased it. The voltage dependency of the steady-state activation of ik was unchanged. Nicorandil did not affect the inward current activated by hyperpolarization (Ih) and the slow inward current (is). These results suggest that the cardiac effects induced by nicorandil must have been produced by selective change in the conductance of ik.

Action Potentials↗
PubMed1984

Effects of cardioplegia induced by a Young's solution (YNG solution) on the blood-perfused canine papillary muscle preparation.

Experiments were carried out in the blood-perfused canine papillary muscle preparation to evaluate the protective effect of a cardioplegic solution, Young's solution (YNG solution), on the myocardial function. Both in spontaneously contracting preparations and in electrically paced (2 Hz) preparations, the time to the cardiac arrest and the time to the maximum blood flow were found to be significantly shorter when the cardiac arrest was induced with cardioplegic solutions than when it was induced with the cold modified Krebs-Ringer's solution (cold cardioplegia). The maximum blood flow of the paced preparation tended to be greater with cardioplegic solutions. The time to resumption of regular contractions was significantly shorter with YNG solution as compared with cold cardioplegia. The developed tension and the blood flow at the time of resumption of the regular contractions tended to approach the control value more quickly with YNG solution, as compared with other cardioplegic solutions and cold cardioplegia. It is concluded that YNG solution represents an optimal cardioplegic solution.

Animals↗
PubMed1984

The sequence and correlation of the changes in several parameters of energy metabolism induced by ischemic insult in heart muscle.

Samples of myocardium with varying degrees of ischemia were obtained from subendo- and subepicardium of nonischemic, ischemic border and center zones of canine left ventricles to assess the sequence of rapid alterations of several parameters of energy metabolism induced by myocardial ischemia. Ischemia was induced by occluding the left anterior descending coronary artery. The contents of creatine phosphate (CP) and ATP decreased significantly. There was a significant accumulation of lactate. The redox potential (Eh) and phosphorylation potential (l') also decreased sharply, but only a slight decrease in energy charge (E.C.) was noted. A close correlation was found between ATP and total adenine nucleotide (r = 0.99). There were various degrees of linear correlation between other parameters, except for ATP (and total adenine nucleotide) and Pi, and CP and l', which were uncorrelated. The sequence of rapid alterations in the parameters of energy metabolism induced by ischemia was: (1) l' and CP, (2) Pi, ATP and Eh, and finally (3) lactate and E.C. A significant increase of the heart rate and a decline of the mean blood pressure and left ventricular pressure (LVP) were also observed in association with a slight change in the maximum rate of rise of the left ventricular pressure (dP/dtmax).

Adenine Nucleotides↗
PubMed1984

[Evaluation on ceftriaxone in the pediatric field].

Fundamental and clinical evaluation on ceftriaxone (CTRX, Ro 13-9904) was performed in the pediatric field and the following results were obtained. The MIC of CTRX against the recently isolated 10 strains of B. pertussis was less than or equal to 0.05 microgram/ml at inoculum size of 10(6) CFU/ml. The blood level of CTRX after intravenous drip infusion with 10 to 20 mg/kg for 30 minutes to 1 hour reached a peak ranging from 45.3 to 137 micrograms/ml at the end of infusion. The effective blood level was maintained up to 12 hours to be 3.52 to 26.7 micrograms/ml at that time. The half-life time was over 6 hours in most cases, but the multiple intravenous dosage did not cause any elevation of the blood level. The urine excretion rate till 12 to 24 hours after intravenous drip infusion ranged from 58.2 to 84.2%. The excretion of CTRX into the cerebrospinal fluid was favorable in the acute period when administered by intravenous drip infusion in the child with S. pneumoniae purulent meningitis, which was considered to be satisfactory for treatment against the bacteria susceptible to CTRX. The active CTRX was transferred into the feces by the multiple dosage. CTRX was administered by intravenous drip infusion in 26 cases with acute pediatric infections. The clinical efficacy was observed in all the cases with upper/lower respiratory tract infections including bronchopneumonia and pertussis, and the cases with acute urinary tract infections caused by ABPC-resistant E. coli, administered by intravenous drip infusion twice daily with about 40-50 mg/kg/day. The bactericidal efficacy was seen against all bacteria except Salmonella. CTRX by intravenous drip infusion was effective against S. pneumoniae purulent meningitis; the clinical symptom was rapidly improved while the culture of causative strains from the cerebrospinal fluid turned negative. Although CTRX was clinically effective against Salmonella enteritis and typhoid, bacteriological and symptomatological relapses were observed in some cases. An increase in dose of CTRX is considered to be needed for these diseases. No adverse reaction was found clinically but soft stool in 1 case while eosinophilia and thrombocytosis were observed each in 1 out of 30 cases in laboratory test. The efficacy was good or higher in all the 26 cases (100%) administered by intravenous drip infusion. The above-mentioned results indicate that CTRX is useful in the pediatric field.

Bacteria↗
PubMed1984

Development of histamine tachyphylaxis in the guinea-pig mesenteric artery.

Histamine, norepinephrine and KCl each evoke contractile responses in isolated guinea-pig mesenteric artery. However, only the contractile response to histamine was characterized by acute desensitization or tachyphylaxis. The tachyphylaxis observed to histamine was independent of the time interval between successive administrations up to at least 1 hr. The histamine H1-receptor blocker, chlorpheniramine (10(-9) M), completely inhibited contractile responses to histamine (10(-5) M). In contrast, metiamide (10(-4) M), an H2-receptor blocker, potentiated contractions which were characterized by tachyphylaxis. Propranolol (10(-6) M), phentolamine (10(-6) M) and atropine (10(-6) M) affected neither the contractile response itself nor the tachyphylaxis to histamine (10(-5) M). Indomethacin (10(-5) M) and aspirin (3 X 10(-4) M) potentiated the initial contraction induced by histamine (10(-5) M) and completely abolished the tachyphylaxis. The response to the initial application of histamine (10(-5) M) was not affected by the reduction of [Ca++] to 0.25 mM or by diltiazem (10(-5) M) or verapamil (10(-5) M). The tachyphylaxis to histamine was, however, suppressed slightly but significantly by the reduction of [Ca++]o and by Ca++ antagonists. These results suggest that the development of tachyphylaxis to histamine in the isolated guinea-pig mesenteric artery may result from the production of prostaglandins which are sensitive to Ca++.

Animals↗
PubMed1984

[Pharmacological studies of a new sleep-inducer, 1H-1,2,4-triazolyl benzophenone derivative (450191-S) (V). General pharmacological activities].

General pharmacological activities of 450191-S were studied in various species of animals and compared with those of reference benzodiazepines (BDZ). 450191-S at doses of 10 mg/kg slightly decreased (-5 degrees C) the rectal temperature of rabbits. 450191-S decreased respiratory and heart rates in anesthetized cats, but the effects were less than those of diazepam or triazolam. 450191-S increased respiratory and heart rates in conscious dogs, but had no effect on the blood pressure, electrocardiogram and autonomic nervous system in cats and dogs. The drug displayed a slight spasmolytic activity in the small intestine of guinea pigs and a slight inhibitory effect on isolated non-pregnant and pregnant uteri of rats. These effects were less than those of diazepam or nitrazepam. Below doses of 25 mg/kg, 450191-S did not affect urinary volume and electrolyte excretions in rats. It also decreased brain norepinephrine (NE) turnover rates in rats, but decreased NE and dopamine turnover rates in mice. These effects of 450191-S were less than those of nitrazepam. 450191-S was found to be minimally irritating to the ocular mucosa in rabbits and did not irritate the stomach and small intestine in rats. These effects were also compared with those of active metabolites of 450191-S, M-1, M-2, M-A, M-3 and M-4, and the superiority of the mother compound over its metabolites was clarified.

Animals↗
PubMed1984

[Effects of N-696, a new beta-blocking agent, on canine experimental arrhythmias].

We evaluated antiarrhythmic effects of N-696 using canine digitalis ventricular arrhythmia models and electrophysiological actions of N-696 using canine ventricular muscles and isolated blood perfused A-V node preparations and compared the effects with those of propranolol. 1) N-696 at 30 mg/kg, i.v. was not effective on digitalis arrhythmia, but reduced the total heart rate and atrial rate for 60 min and transiently decreased the blood pressure. Propranolol at 3 mg/kg, i.v. transiently suppressed digitalis ventricular arrhythmia and decreased the total heart rate, atrial rate and blood pressure. The minimum effective plasma concentration of propranolol was 1.7 +/- 0.4 microgram/ml. 2) Ten to 100 micrograms/ml N-696 and 3 to 10 micrograms/ml propranolol did not affect the resting potential and the action potential duration at 75% repolarization of the canine ventricular muscle, but decreased the maximum rate of rise of the action potential in a dose-dependent fashion, and 100 micrograms/ml N-696 decreased significantly the action potential amplitude. The minimum effective drug concentration of N-696 was 60 micrograms/ml, and that of propranolol was 6 micrograms/ml. 3) N-696 (30 micrograms-3mg) dose-dependently delayed the A-V conduction time of the isolated blood perfused A-V node preparation when it was administered into the posterior septal artery (PSA) and the anterior septal artery (ASA). Propranolol (10-600 micrograms) also had similar effects, but the doses of N-696 delaying the A-V conduction time by 15% was about 8 to 21 times higher than those of propranolol.

Adrenergic beta-Antagonists↗
PubMed1984

[Antitumor activity of Lactobacillus casei YIT 9018 (LC 9018)--effect of administration route].

Antitumor activity of lactobacilli on Sarcoma 180 was investigated and was shown to be different from strain to strain. In general, Lactobacillus casei had higher antitumor activity compared with other species of lactobacilli. Among these, L. casei YIT 9018 (LC 9018) had significant antitumor activity against Meth A fibrosarcoma when administered into BALB/c mice intravenously, intraperitoneally, subcutaneously, intratumorally or orally. LC 9018 showed antitumor activity against rat ascites hepatoma by intravenous or oral administration, but this activity was lower than that against Meth A in mice.

Adjuvants, Immunologic↗