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Biomedical subjects

T Satake

Publications and source records attributed to T Satake.

299 records · Page 17Linked to original sources
PubMedDate not supplied

Ages at peak velocity and peak velocities for seven body dimensions in Japanese children.

Seven body dimensions of 37 Japanese children, 16 boys and 21 girls, were measured longitudinally at 6-monthly intervals from 9 through 15 years of age. Spline curves were fitted to the longitudinal data of each dimension to obtain age at peak velocity and magnitude of peak velocity for each child. Ages at peak velocity for each dimension occurred, on average, later in boys than in girls. Mean peak velocities were also larger in boys except for chest circumference. Ages at peak velocity occurred, on average, earlier in Japanese than in European and North American children.

Adolescent↗
PubMedDate not supplied

Myocardial concentration of norepinephrine and cyclic AMP in ventricular fibrillation during acute myocardial ischemia.

To clarify the relationship between the concentrations of norepinephrine (NE) and cyclic AMP (c-AMP) in the myocardium and the incidence of ventricular fibrillation (VF), we studied 48 dogs in which VF was induced by the ligation of the left anterior descending coronary artery. The animals were divided into two groups of equal size: The first received no drugs, the second received d,l-propranolol (0.5 mg/kg) 15 min before coronary ligation. Myocardial samples were taken at regular intervals from normal and ischemic areas to determine NE and c-AMP concentrations. In the untreated group, no significant change in the concentrations of NE and c-AMP was observed in 12 dogs that did not develop VF. In the other 12 dogs that developed VF, there was a significant increase in c-AMP in the ischemic area immediately after the onset of the dysrhythmia. A significant increase in NE concentration both in normal and ischemic myocardium was observed in only 8 of these latter 12 dogs. Premedication with propranolol significantly reduced the incidence of VF, but it still occurred in 5 out of 24 dogs. Increase in c-AMP without an increase in NE in ischemic area was observed in these five dogs. These results suggest that c-AMP may play a role in the development of VF during acute ischemia.

Animals↗
PubMedDate not supplied

Pretreatment with chlorpromazine prevents phospholipid degradation and creatine kinase depletion in isoproterenol-induced myocardial damage in rats.

We investigated the effect of chlorpromazine on myocardial phospholipid content and composition and on myocardial creatine kinase (CK) activity in rats with isoproterenol-induced myocardial damage. A single subcutaneous injection of isoproterenol (40 mg/kg) increased heart weight but decreased myocardial phospholipid content and CK activity 24 h after administration. Total phospholipid content was significantly correlated with myocardial CK activity. The decrease of total phospholipid content was accompanied by an increase of the lysophosphatidylcholine (LPC)/phosphatidylcholine (PC) ratio, indicating that conversion from PC to LPC had occurred. Intraperitoneal injection of chlorpromazine (30 mg/kg) prior to isoproterenol injection inhibited the decrease in total phospholipid content and CK activity and the increase in the LPC/PC ratio, but did not affect the increase in heart weight. Pretreatment with propranolol (20 mg/kg) reversed the effects of isoproterenol. On the other hand, dexamethasone (12 mg/kg) and verapamil (50 mg/kg) had no significant effects on the above parameters of myocardial damage. These results suggest that prevention of myocardial phospholipid disruption inhibits enzyme depletion from the myocardium and that chlorpromazine helps to prevent isoproterenol-induced myocardial damage by improving phospholipid metabolism.

Animals↗
PubMedDate not supplied

Simultaneous measurement of intraosseous and cerebrospinal fluid pressures in lumbar region.

Intraosseous pressure (IOP) and cerebrospinal fluid pressure (CSFP) in the lumbar region were measured simultaneously in two groups of patients with either spinal canal stenosis or disc herniation, to compare dynamic changes with positional changes, and to learn whether these pressure changes may have some role in the onset of claudication. IOP and CSFP showed almost the same change patterns with positional changes in two groups. They were lowest in the prone position and highest at the standing position. In standing with flexion, they were almost the same as in the prone position, but in extension they increased above the standing pressure. These dynamic pressure changes could act as a compression force to the cauda equina in the patient with spinal canal stenosis.

Adult↗
PubMedDate not supplied

Endotoxin affects the expansion modes of liver macrophages after partial hepatectomy.

We studied the effect of increased endotoxin levels on the expansion modes of liver macrophages after two-thirds partial hepatectomy using anti-endotoxin polymyxin B. The expansion consists of dual modes: local proliferation and immigration. Local proliferation of mature cells was evaluated by the S-phase proportion measured by flow cytometric DNA analysis. This proportion (11.8 +/- 1.3% before hepatectomy) decreased to 6.0 +/- 1.1% at 12 h and reached a maximum of 21.9 +/- 2.7% on the 5th day after hepatectomy. In polymyxin B treated rats, the proportion reached a maximum of 21.1 +/- 1.6% at 48 h without any preceding decrease. Immigration of macrophage precursors was evaluated by the decreasing proportion of latex beads-containing cells that were marked as resident liver macrophages by injection of latex beads before hepatectomy. This proportion (98.7 +/- 0.2% before hepatectomy) was significantly decreased to 90.5 +/- 1.6% at 48 h. In polymyxin B treated rats, however, the proportion showed no significant decrease within 3 days. These results indicate that endogenous endotoxin, which suppresses the local proliferation and promotes extrahepatic recruitment, regulates the number of liver macrophages in regenerating rat liver.

Animals↗
PubMedDate not supplied

Biochemical changes in airways after antigen inhalation.

These results suggest that activation of phospholipase A2 after antigen exposure triggers an increase in leukotriene synthesis resulting in inflammatory cell influx into the airway and contraction of bronchial smooth muscle. That is, it was demonstrated that inhaled antigen concerns with IgE-mast cell system, but, on the other hand it might act as non specific stimuli.

Administration, Oral↗
PubMedDate not supplied

Effects of sodium channel blockers on electrical field stimulation-induced guinea-pig tracheal smooth muscle contraction.

The effects of sodium channel blockers, a conventional one: tetrodotoxin, and clinically available ones: cibenzoline, flecainide and SUN 1165 [N-(2,6-dimethylphenyl)-8-pyrrolizidine-acetamide hydrochloride hemihydrate] on electrical field stimulation-induced and carbachol-induced guinea-pig tracheal smooth muscle contraction were investigated. Electrical field stimulation was performed at 50 V with 20 Hz and 0.8 msec square pulse duration. Carbachol (5 x 10(-8) M) was used for induction of tracheal contractions. All agents were administered before electrical field stimulation or carbachol administration. Electrical field stimulation-induced tracheal smooth muscle contraction was dose-dependently reduced by all sodium channel blockers used. The effects of sodium channel blockers on electrical field stimulation-induced contraction were greater than those on carbachol-induced contractions, except for SUN 1165 which reduced similarly both electrical field stimulation- and carbachol-induced contractions. These results indicate that the sodium influx is closely related to the acetylcholine release, resulting in smooth muscle contraction. Since the parasympathetic nervous system may be involved in the genesis of various pathological conditions, such as bronchial asthma, sodium channel blockers could contribute to the management of these conditions.

Animals↗
PubMedDate not supplied

Changes in the number of beta-adrenergic receptors of lymphocytes in patients with varying degrees of congestive heart failure.

This study was designed to determine changes in the number of beta-adrenergic receptors of circulating lymphocytes in patients with varying degrees of congestive heart failure. Thirty-seven patients with congestive heart failure were classified into four groups according to the functional classifications of the New York Heart Association (class I, 12 patients; class II, 12 patients; class III, eight patients; class IV, five patients). The control group consisted of 24 healthy volunteers. Binding assays of beta-adrenergic receptors in circulating lymphocytes and plasma norepinephrine concentrations were determined in each group. Compared with the control group, the number of beta-adrenergic receptors in patients of the class-III and class-IV groups was reduced by 37% and 36%, respectively, and plasma norepinephrine concentrations of class-III and class-IV patients were increased by 3.5 times and 5.9 times, respectively. No significant changes in the numbers of beta-adrenergic receptors or in plasma norepinephrine concentrations were observed in patients of the class-I and class-II groups. These findings show a decrease in the number of beta-adrenergic receptors in patients with high plasma norepinephrine concentrations. It is suggested that the chronically high concentration of norepinephrine, resulting from activation of the sympathetic nervous system associated with severe congestive heart failure, is linked with the down regulation of beta-adrenergic receptors. The action of sympathomimetic amines may therefore be altered in patients with congestive heart failure.

Heart Failure↗
PubMedDate not supplied

Biochemical and antiarrhythmic effects of three calcium channel antagonists in ischemic canine hearts.

The cardioprotective and antiarrhythmic effects of diltiazem, nilvadipine, and verapamil were evaluated in 33 dogs. The left anterior descending coronary artery (LAD) was occluded for two hours, 25 minutes after saline administration (controls); ten minutes after diltiazem (0.25 mg/kg); 15 minutes after nilvadipine (1 micrograms/kg/min); or ten minutes after verapamil (0.4 mg/kg). Changes in blood pressure and heart rate were monitored throughout the experiment. Two hours after LAD occlusion, mitochondria were prepared from ischemic and nonischemic areas and their function was measured polarographically. Fractionation of myocardial tissue from the ischemic and nonischemic areas was performed and activities of lysosomal enzymes were measured. LAD occlusion induced mitochondrial dysfunction and leakage of lysosomal enzymes in the ischemic area. Administration of the calcium antagonists preserved mitochondrial function and prevented leakage of lysosomal enzymes. All three calcium antagonists reduced the incidence of ventricular arrhythmias during ischemia. The results indicate that calcium may play an important role in the development of biochemical and electrical disturbances during ischemia.

Acetylglucosaminidase↗
PubMedDate not supplied

Thin slice CT study of solitary pulmonary nodules with emphasis on the relation to vasculatures.

Thin (2 mm) and thick (10 mm) slice X-ray computed tomography (CT) scanning was performed in 49 and 31 patients, respectively, to assess the morphology of solitary pulmonary nodules or masses and to determine the relationship between the tumor and surrounding vasculature. When the pulmonary vein passed singly into the tumor or was larger than the artery (pattern I), 38 of 40 nodules (95%) were malignant (p less than 0.001). When the pulmonary artery passed singly into the tumor or was larger than the vein (pattern II) and when no pulmonary vessel passed into the tumor but when a pulmonary vessel was compressed by the tumor or passed through it (pattern III), only 11 of 19 nodules (58%) were malignant. Based on the morphology and vasculature patterns the accuracy of diagnosis with thin slice CT was 80.9% while that of thick slice CT was 67.7%. Thin slice CT can increase the diagnostic accuracy of primary lung cancer.

Adult↗