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Biomedical subjects

S Satoh

Publications and source records attributed to S Satoh.

At least 595 records · Page 33Linked to original sources
PubMed1990

Effects of adenosine on adrenergically induced renal vasoconstriction in dogs.

The role of exogenous and endogenous adenosine in the neural control of renal blood flow was studied in anesthetized dogs. The plasma norepinephrine (NE) concentration was measured by high-performance liquid chromatography and the renal NE secretion rate was calculated. Renal nerve stimulation (1-3 Hz) reduced renal blood flow and increased NE secretion rate. The intrarenal arterial injection of NE (0.3-1.0 micrograms) also reduced renal blood flow. Infusion of adenosine (10-100 micrograms/min) into the renal artery attenuated the increase in NE secretion rate induced by renal nerve stimulation, but the nerve stimulation-induced decrease in renal blood flow was unaffected. On the other hand, adenosine potentiated the NE-induced renal blood flow response. Similar results were obtained with an adenosine potentiator, dipyridamole (1-10 micrograms/min). An adenosine receptor blocker, theophylline (0.3-1.0 mg/min), potentiated the NE secretion rate response induced by nerve stimulation, without any change in the renal blood flow response. The NE-induced renal blood flow response was attenuated by theophylline. These results suggest that adenosine inhibits neural NE release and enhances vasoconstriction in the dog kidney during sympathetic stimulation under in vivo conditions. These post- and presynaptic mechanisms may thus be activated by endogenous adenosine.

Adenosine↗
PubMed1990

Endothelin causes contraction of canine and bovine arterial smooth muscle in vitro and in vivo.

We have studied the effect of endothelin, an endothelium-derived peptide, on isolated canine and bovine cerebral arteries in vitro and on canine vertebral blood flow (VBF) in vivo. Endothelin produced a dose-dependent contraction of canine and bovine arterial smooth muscle with ED50 values ranging from 4 to 8 nM. The response to endothelin developed slowly and persisted as a sustained contraction. Maximal contraction by endothelin required the presence of extracellular calcium and was independent of the presence of endothelium. The maximal contraction produced by endothelin was approximately 2-3 times greater than that produced by neuropeptide Y or angiotensin II. The injection of endothelin into the vertebral artery decreased vertebral blood flow (VBF) dose-dependently without affecting systemic blood pressure or heart rate. The decrease in VBF produced by endothelin was long-lasting, like that produced by neuropeptide Y, but more potent. The present data, together with our previous study demonstrating that the intracisternal injection of endothelin induces an unusually long-lasting decrease in the basilar artery diameter angiographically, suggests that endothelin may act as a long-lasting vasoconstrictor in cerebral vascular disease.

Angiotensin II↗
PubMed1990

The antiarrhythmic effect of flecainide on halothane-epinephrine induced arrhythmias in dogs.

The antiarrhythmic effect of flecainide acetate (FCN), a newly developed class I antiarrhythmic drug, was evaluated on epinephrine (E)-halothane induced arrhythmias in dogs. The arrhythmogenic dose of E (ADE) under 1% of halothane was significantly increased from 0.71 +/- 0.08 to 1.08 +/- 0.11 and 1.84 +/- 0.23 micro g.kg(-1).min(-1) by the administration of 2 and 4 mg.kg(-1) of FCN, respectively. The arrhythmias induced by ADE in the absence of FCN were stopped by 1.78 +/- 0.29 mg.kg(-1) of FCN in bolus injections. These results suggest that FCN can be used for the treatment of arrhythmias that E contributes to under halothane anesthesia.

Journal Article↗
PubMed1990

Fetal eye movement assessed with real-time ultrasonography: are there rapid and slow eye movements?

The goal of this study was to determine whether rapid eye movement and slow eye movement exist during the eye-movement period in the human fetus in utero. We studied 21 fetuses with real-time ultrasonography, 10 from 33 to 36 weeks and 11 from 37 to 41 weeks' gestation. We used the duration of eye-movement unit as a parameter and calculated the cumulative duration from the shortest to a given duration of eye movement per individual case. A scattergram of cumulative duration versus given duration obtained from all cases in each age group was analyzed with piecewise linear regression to search for a critical point(s). Critical given duration points were noted and reached statistical significance at 0.62 second and at 0.76 second during 33 to 36 and 37 to 40 weeks of gestation, respectively. These findings reveal two different types of eye movement: one with a duration of less than 0.6 to 0.8 second and the other with a duration of greater than 0.6 to 0.8 second. These findings are compatible with previous criteria on rapid and slow eye movements, respectively, at 33 weeks of gestation onward. The mean value of cumulative duration at the critical point increased from 29.0% between 33 and 36 weeks to 47.1% between 37 and 41 weeks of gestation, indicating an increase in the proportionate amount of time maintaining rapid eye movement as gestation advances.

Eye Movements↗
PubMed1990

Relationship between heart rate and rhythm, and cardiac performance assessed in the human fetus in utero.

To evaluate the relationship between heart rate and rhythm, and cardiac performance, in the human fetus in utero, observed over a long-term period in gestation, we made a total of 138 studies in 114 fetuses from 18 to 41 weeks of gestation; 104 having heart rate changes without rhythm disturbances ("control group"), 6 with complete atrioventricular block and 4 with supraventricular tachycardia. Using M-mode echocardiogram, we measured end-diastolic dimension and fractional shortening in the right and left ventricles. The corresponding heart rate for each cardiac cycle was measured using the interval between two consecutive end-systolic points. In fetuses in the group of controls, the values for fractional shortening in both ventricles were almost constant with advancing gestational age, unrelated to an increase in end-diastolic dimensions of either ventricle. There was no correlation between changes in heart rate and changes in the value of ventricular fractional shortening at any period of gestation studied. In the fetuses with atrioventricular block, dimensions and fractional shortenings in both ventricles were significantly larger than those in the group of control fetuses at the same stage of gestation. This indicates that the fetal heart is capable of acclimatizing itself, beginning as early as 18-25 weeks of gestation, to long-lasting bradycardia in which an increased stroke volume would be required. In fetuses with supraventricular tachycardia, end-diastolic dimensions were larger and fractional shortening was significantly smaller in both ventricles than in fetuses from the control group from 26-30 weeks of gestation onwards. This suggests tachycardia-induced cardiomyopathy occurring during intrauterine life.

Echocardiography↗
PubMed1990

Chronological development of the fetal stomach assessed using real-time ultrasound.

To elucidate processes involved in the developing fetal stomach in utero, we examined chronological changes in maximum longitudinal and anteroposterior gastric dimensions in 618 fetuses from 16 to 41 weeks of gestation, using real-time ultrasound. Three statistically critical points were evident at 26-27, 32-33, and 36-37 weeks of gestation. Both dimensions increased from 16-17 to 26-27 weeks, remained fairly constant between 26-27 and 32-33 weeks, increased again from 32-33 to 36-37 weeks, and then decreased from 36-37 weeks onwards. These findings suggest that there are four different phases underlying the development of gastric function in the human fetus, corresponding to the time-periods divided by the three critical points of gestational age.

Embryonic and Fetal Development↗
PubMed1990

Coronary zero flow pressure and intramyocardial pressure in transiently arrested heart.

STUDY OBJECTIVE: The aim of the study was to examine the relation between zero flow pressure and intramyocardial pressure in the inner and outer layers of the myocardium. DESIGN: Zero flow pressure was obtained in maximally vasodilated excised hearts by decreasing perfusion pressure (at 2 mm Hg.s-1) during transient heart arrest. Intramyocardial pressures in inner and outer myocardium were measured simultaneously with needle tip pressure transducers at depths of 8.0(SD 2.6) and 3.3(1.2) mm from the epicardium respectively. Ventricular and atrial pressure could be controlled at will. EXPERIMENTAL MATERIAL: The excised hearts of eight mongrel dogs, body weight 14.0(0.8) kg, were used. MEASUREMENTS AND MAIN RESULTS: During left ventricular pressure elevation (0, 15, 30 mm Hg), zero flow pressures were 9.1(2.4), 13.8(2.2), and 19.1(5.1) mm Hg, respectively. Corresponding values of intramyocardial pressure at the outer myocardium were in good agreement with the zero flow pressures, at 9.1(3.4), 13.4(2.8), and 20.8(5.4) mm Hg. Values at the inner myocardium increased from 7.4(2.4) to 18.9(8.6) and 32.9(13.0) mm Hg. The latter two values were significantly higher than the corresponding values of zero flow pressure and intramyocardial pressure at the outer myocardium (p less than 0.05, p less than 0.01). In isotransmural pressure elevation, the three pressures increased almost equally. CONCLUSIONS: The results show that zero flow pressure is strongly affected by intramyocardial tissue pressure, and if uneven intramyocardial pressure distribution is present the value of zero flow pressure depends on the lower values of intramyocardial pressure.

Animals↗
PubMed1990

Adrenoceptor-blocking activity and cardiohemodynamic effects of carvedilol in animals.

The beta-blocking activities of a new beta-adrenoceptor blocking drug, carvedilol, evaluated in isolated atria and trachea of the guinea pig were 2.0 (beta 1) and 3.2 times (beta 2), respectively, as potent as those of propranolol. Carvedilol exhibited the alpha-blocking activities in the aorta of guinea pigs and rats. Carvedilol was 2 and 50 times less potent in guinea pigs and rats, respectively, than prazosin as an alpha-blocker. Thus, the alpha-blocking activities were twice as potent as the beta-blocking activity in the rat and one-fifth that of the beta-blocking activity in the guinea pig. In anesthetized open-chest dogs, the beta-blocking activity of carvedilol was 1.5 times more potent than that of propranolol and had 3.8 times the alpha-blocking activity. Thus, carvedilol is a nonselective beta-blocking drug with a potent alpha-blocking activity. Carvedilol and propranolol showed dose-dependent and significant decreases in the blood pressure, total cardiac output, left ventricular pressure, dp/dt, heart rate, coronary flow, and oxygen consumption in anesthetized open-chest dogs. Carvedilol decreased the total peripheral resistance significantly (the decrease was not proportional to the decreases in the blood pressure at high doses), while propranolol increased it significantly and dose-dependently. These results indicate the importance of alpha-adrenoceptor blocking activity in the decrease in blood pressure produced by carvedilol.

Adrenergic alpha-Antagonists↗
PubMed1990

Effects of a novel Ca2+ entry blocker, CD-349, and TMB-8 on renal vasoconstriction induced by angiotensin II and vasopressin in dogs.

The effects of a Ca2+ entry blocker CD-349 and an intracellular Ca2+ release inhibitor TMB-8 on renal vasoconstriction induced by angiotensin II (ANG II) and arg-vasopressin (AVP) were examined in anesthetized dogs. Intrarenal bolus injection of ANG II (3-10 ng/kg), AVP (5-20 ng/kg) or a Ca2+ entry promotor Bay K 8644 (0.1-0.4 micrograms/kg) produced a dose-dependent decrease in renal blood flow (RBF). Intrarenal infusion of CD-349 (0.03-0.3 micrograms/kg/min) suppressed the RBF responses to ANG II, AVP, and Bay K 8644. The RBF responses to ANG II and AVP were augmented slightly by intrarenal infusion of Bay K 8644 (0.3 micrograms/kg/min). Intrarenal infusion of TMB-8 (0.03-0.1 mg/kg/min) also suppressed the RBF responses to ANG II and AVP, whereas it did not affect the RBF response to Bay K 8644. These results suggest that vasoconstriction induced by ANG II or AVP is mediated both by the influx of Ca2+ through dihydropyridine-sensitive Ca2+ channels and the release of Ca2+ from TMB-8-sensitive Ca2+ pools in the in vivo dog kidney.

3-Pyridinecarboxylic acid, 1,4-dihydro-2,6-dimethy↗
PubMed1990

Blood component induction of cerebral vasospasm.

The role of blood components in cerebral vasospasm was evaluated using an in vivo canine model. An intracisternal injection of 5 ml of washed red blood cells (RBCs) and platelet-rich plasma (PRP) resulted in acute vasospasm of the basilar artery as seen by angiography. This was comparable with the degree of vasospasm induced by an injection of the same amount of whole blood. Repeated injections of blood components or whole blood on Days 1 and 3 induced chronic vasospasm, as shown by angiography on Day 7. Results clearly indicate that chronic vasospasm was produced by RBCs and PRP, and it was in a dose-dependent manner with increasing concentrations of RBCs (hematocrit: 30, 50, and 70%). The vasospasm induced by both components closely reproduced that seen with whole blood. Neither acute nor chronic vasospasm induced by blood component injection was associated with clot formation in the subarachnoid space, as confirmed by an autopsy. These results suggest that the extravasation of RBCs and PRP into the subarachnoid space produces cerebral vasospasm by mechanisms independent of blood clot formation.

Animals↗
PubMed1990

Effects of atrial natriuretic peptide on phenylephrine-induced renin release in dogs.

1. The effect of atrial natriuretic peptide (ANP) on alpha-adrenoceptor agonist-induced renin release was examined in the de-ennervated kidney of the anaesthetized dog pretreated with propranolol (1 mg/kg, intravenous). 2. Phenylephrine (50 ng/kg per min) infused into the renal artery increased the renal secretion rate of renin (RSR) without affecting systemic blood pressure or renal blood flow. 3. Although basal RSR was unaffected, the phenylephrine-induced increase in RSR was abolished during intrarenal arterial infusion of ANP (10 ng/kg per min). 4. The results suggests that exogenously administered ANP could suppress alpha-adrenoceptor-mediated renin release in the dog.

Animals↗
PubMed1990

Depression in members of a new religious sect in Japan.

We investigated 226 people belonging to a regional church of a new religious sect (hereinafter referred to as religious group) and 899 ordinary people living in the rural area near this church (hereinafter referred to as nonreligious group) with a questionnaire using Zung's Self-Rating Depression Scale (SDS). In males ranging in age from 40 to 69, the mean scores of 7 SDS items out of 20 were significantly higher in the religious group than in the nonreligious group. Males at the age of 70 or older in both groups, however, did not show any significant difference in these items. It suggests that the religious affiliation exerted mentally good effects on the older male members.

Adaptation, Psychological↗
PubMed1990

Rectal carcinoid tumor metastasizing to the thyroid and pancreas. An autopsy case exploiting immunohistochemistry for differentiation from tumors involving multiple endocrine organs.

A 58-year-old male patient with rectal carcinoid tumor is presented. The tumor extensively involved the lymph nodes and liver, and multiple tumors were also recognized in the pancreas and thyroid. Grossly, it was uncertain whether the latter were metastases from the rectal carcinoid or all were coincident primary tumors involving multiple endocrine organs, so-called multiple endocrine neoplasia (MEN) syndrome. Histologic, histochemical and electron microscopic examinations of the tumors in both the pancreas and thyroid showed similar features to those of the rectal carcinoid. The neoplastic cells in all involved organs commonly expressed positive immunoreactivity for somatostatin, but negativity for carcinoembryonic antigen, calcitonin, calcitonin gene-related peptide, thyroglobulin, insulin, glucagon and pancreatic polypeptide. These immunohistochemical results confirmed that the tumors observed in multiple endocrine organs were indeed metastatic from the rectal carcinoid, rather than being a new combination of MEN syndrome. Some neuroendocrine tumors may develop widespread metastasis, sometimes creating problems with differentiation from multiple primary endocrine tumors. Immunohistochemistry may be of great help in setting this issue.

Carcinoid Tumor↗
PubMed1990

Percutaneous treatments for biliary diseases.

Percutaneous treatment of biliary disease was administered in 173 cases, mainly among high-risk or elderly patients. Diagnosis was acute cholecystitis in 32 cases, acute cholangitis in 16, hepatic abscess in five, gallbladder stones in 28, common bile duct stones in 11, intrahepatic stones in five, malignant obstructive jaundice in 61, and benign biliary stenosis in 15. The treatment was successful in 158 of 173 cases (91.3%). Complications were encountered in 17 (9.8%). Most of these occurred during the initial period and were mild and controllable with conservative treatments. There were two deaths (1.2% of patients); one was not related to the procedure. These data suggest that percutaneous treatments are safe and effective even among elderly or high-risk patients with biliary diseases.

Adult↗
PubMed1990

Smooth muscles from spastic coronary artery segments show hypercontractility to histamine.

An animal model of coronary spasm was produced in Göttingen miniature pigs by a selective endothelial denudation of the coronary artery. Five months after the denudation, intracoronary bolus administration of 10 micrograms/kg histamine reduced the luminal diameter angiographically by 57 +/- 16 and 17 +/- 10% (P less than 0.01) in the previously denuded and contralateral control coronary arteries. Muscle fibers of 0.08-0.1 mm wide were prepared from circumferential bundles of the medial smooth muscle in the spastic and nonspastic coronary arteries. Upward shifts of either dose-tonic contraction relationships in Ca2(+)-containing solution or dose-monophasic contraction relationships in Ca2(+)-free solution were noted in muscle fibers taken from the spastic site compared with those from the nonspastic site with no difference between the mean effective dose values. After skinning the muscle fibers with saponin, there was no significant difference in the Ca2+ concentration-tension relationships between the two fibers. These findings suggest that an increased number of histaminergic receptors and/or augmentation of signal transduction, but not Ca2+ sensitivity of the contractile proteins in the medial smooth muscle cells, cause histamine-induced coronary hypercontraction.

Animals↗
PubMed1990

Increased dependence on slow filling for left ventricular diastolic filling in patients with coronary artery disease and a depressed systolic function--assessment with radionuclide ventriculography.

Contributions of rapid filling, slow filling and atrial systole to the left ventricular (LV) filling volume were analyzed with the use of radionuclide ventriculography at rest, both globally and regionally, in 34 patients with isolated disease of the left anterior descending coronary artery. The patients included 17 with a normal ejection fraction (EF greater than or equal to 50%; group 1) and 17 with a depressed EF (less than 50%; group 2), and the data were compared with those obtained from 13 normal subjects. A computer program subdivided the LV image into 4 regions, and time-activity curves were constructed globally and regionally by reverse-gating from the R wave. In both groups the contribution of rapid filling to the LV filling volume was decreased significantly in the affected septal and apical regions, and in the global left ventricle compared with that in normal subjects. In group 1, the contribution of atrial systole showed an increase in these affected regions and in the global left ventricle. In contrast, in group 2, the atrial contribution was not increased globally or regionally as much as was expected. However, the contribution of slow filling was either increased significantly or tended to increase in the affected regions and in the global left ventricle. There were negative correlations between the contribution of rapid filling and that of slow filling in the global left ventricle (r = -0.73, p less than 0.001) and in each of the septal, apical and lateral regions (r greater than or equal to -0.60, p less than 0.001), which suggested that the contribution of slow filling as well as of atrial systole undergoes an increase as rapid filling is impaired. Thus, in patients with coronary artery disease, the left ventricle relies on slow filling as well as atrial systole to affect diastolic LV filling in the affected regions and in the global left ventricle in the presence of LV systolic dysfunction.

Adult↗
PubMed1990

[Mental health in software engineers. I. Frequency of mental complaints, physical complaints and psychiatric disorders].

This study examined the physical complaints, mental complaints and psychiatric disorders in software engineers. Subjects were 101 male software engineers. They were evaluated by a semistructured interview. Psychiatric diagnosis was based on DSM-III (Diagnostic and Statistical Manual of Mental Disorders, third edition). The results are summarized as follows: 1) Physical complaints were observed in 68% of the subjects with 25% of the subjects complaining of physical ill-health. This study showed that 12% of the subjects had hypertension, 12%, gastritis or gastro-duodenal ulcer, 14%, allergic disease, and 19% miscellaneous diseases. 2) Of the subjects 62% had mental complaints and 31% mental ill-health. Depressive symptom was the most frequent mental complaint with 32% of the subjects diagnosed as DSM-III. The common diagnoses were adjustment disorders (19%), major affective disorders (6%), psychological factors affecting physical condition (5%) and dysthymic disorder (3%). Only one subject sought professional help from a psychiatrist for relief of mental complaints. The data suggest the severity of mental ill health in software engineers, but methodological limitations preclude a firm conclusion at this time. Further studies should be made on the mental health state in software engineers.

Adult↗