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Biomedical subjects

K Otsuka

Publications and source records attributed to K Otsuka.

At least 343 records · Page 19Linked to original sources
PubMed1983

Studies of arrhythmias by 24-hour polygraphic recordings: relationship between atrioventricular block and sleep states.

The relationship between AV conduction disturbances and sleep states was investigated using continuous polygraphic recordings for one full night. The results were as follows: (1) In the case of first-degree AV block, the phasic shortening of the PQ interval was observed during rapid eye movement (REM) sleep. (2) In the case of second-degree AV block (Wenckebach type), the conduction ratio increased transiently during REM sleep and significant relationships were observed between the number of nonconducted P waves and the mean heart rate in each sleep stage. (3) In the case of advanced AV block, complete AV block was observed less frequently during REM sleep and the period of falling asleep. Since the reproducibility of these results from night to night has not yet been investigated, additional evaluation is required.

Adolescent↗
PubMed1983

Influence of electrical stimulation of the limbic structure on insulin level in rabbit's plasma.

The amygdala (AMYG) stimulation caused a marked decrease in the circulating level of insulin coincident with a considerable rise in the glucose level in rabbits. The stimulation of dorsal hippocampus (DHPC), on the other hand, greatly increased the insulin level and decreased the glucose level. The results suggested that the reciprocal influence of AMYG and DHPC on plasma levels of insulin and glucose played some roles in the regulation of insulin release and the homeostasis glucose metabolism in rabbits.

Amygdala↗
PubMed1983

Influence of lesion of the limbic-hypothalamic system on metabolic responses of acetate to daily repeated cold exposures in rabbits.

The effects of the lesions of basal medial hypothalamus and limbic structure on the acetate metabolic responses to daily repeated cold exposures in rabbit's liver has been investigated. The results obtained were summarized as follows: (1) The lesions of periventricular arcuate nucleus (ARC) had no effects on the acetate metabolism and on the acetate metabolic responses to the 1st cold exposure (cold exposure on the 1st day). (2) The metabolic pattern of acetate and the acetate metabolic responses to the 1st cold exposure were altered by the lesions of ventromedial hypothalamus (VMH), stria terminalis (ST) and dorsal fornix (FX). (3) The effects of cold exposure on the acetate metabolism were completely abolished by the seven times repetition of cold exposures in the rabbits with the lesions of ARC, VMH or ST, as the same as in each sham-operated group. (4) The acetate metabolic responses to cold exposure remained after the seven times repetition of cold exposure in the rabbits with the lesions of FX, but those disappeared completely in sham-operated animals. (5) From these results, it might be suggested that the VMH, amygdala(AMYG)-ST system, dorsal hippocampus(HPC)-FX system played some roles in the metabolic regulation of acetate and in the mechanisms of acetate metabolic responses to the 1st cold exposure, but the ARC did not participate in those mechanisms. And it was suggested that the HPC-FX system participated in the acetate metabolic adaptation to daily cold exposures, but the basal medial hypothalamus and AMYG-ST system did not participate in this process.

Acetates↗
PubMed1983

The usefulness of Holter monitoring in the evaluation of antiarrhythmic drug efficacy for tachycardia.

Using Holter monitoring tachycardia was found in 145 out of 2058 patients suffering from various underlying diseases. Three thousand seven hundred and forty monitorings were performed. The mean age of patients was 54.5 years with a range of 19 to 83 years. The observed tachycardia was classified into three types: tachycardia with short duration, tachycardia with long duration and tachycardia with complex form. The attacks of tachycardia were more frequently observed during periods of physical activity than during sleeping periods. The relationship of the number of tachycardia with short duration between 24-hour Holter monitorings was examined in order to establish day to day variability of the attacks. The 95% confidence interval about the resultant regression line was calculated and the percent reduction required for the evaluation of drug efficacy to avoid the chances of interference of spontaneous variation was found to be about 44.0, 55.0 and 82% when the total number of attacks during a 24-hour period were 50, 100 and 1,000, respectively. Holter monitoring showed higher positive results as compared to exercise testing for detection of tachycardia. Higher correlation coefficients between numbers of premature ventricular contractions (PVCs) and the plasma concentrations of procainamide or N-acetylprocainamide were observed in 3 or more successive PVCs than in individually occurring PVCs. Using repeated 24-hour Holter monitorings a significant reduction in the number of tachycardia was observed when the therapeutic concentration was reached after the combined or single administration of the drug. These results suggest that repeated Holter monitorings, exercise testing and determination of plasma level of the drug may be useful for the evaluation of antiarrhythmic drug efficacy for tachycardia.

Adult↗
PubMed1983

Possible significance of the pharmacological differentiation of beta-blocking agents in hemodynamic effects in essential hypertension.

Thirteen beta-blocking agents with different pharmacological properties were administered orally to 161 outpatients with essential hypertension for 5 weeks to assess their hemodynamic effects. Cardioselective ones, such as atenolol, metoprolol and acebutolol, reduced mean blood pressure (MBP) and the cardiac index. (CI) without any changes of the total peripheral resistance index. (TPRI). In the total 44 patients treated with these drugs, a positive correlation (r = 0.529, p less than 0.005) was found between the decrease in MBP and that of TPRI, but the decrease in MBP did not correlate with that of CI. Effects of non-cardioselective ones were classified arbitrarily into the following 3 patterns: 1) reduction of CI of more than 0.50 L/min/m2 and a slight increase of TPRI by more than 150 dyne . sec . cm-5 . m2 (nadolol, propranolol, o.prenolol and penbutolol), 2) reduction of TPRI by more than 150 dyne . sec . cm-5 . m2 (pindolol, bunitrolol and labetalol) and 3) the intermediate hemodynamic responses between the two patterns described above (carteolol, bupranolol and bufetolol). In all these 3 groups, the decrease in MBP correlated with that of TPRI (the first group, n = 45, r = 0.557, p less than 0.005; the second, n = 37, r = 0.525, p less than 0.005; the third, n = 35, r = 0.612, p less than 0.005), but did not correlate with the decrease of CI. These results suggest that the antihypertensive effects of beta-blocking agents mainly depend on the reduction of peripheral resistance, although their pharmacological properties are not uniform and their cardiodepressant effects are variable. Reduction of cardiac performance with these beta-blocking agents seemed to be a consequence of overall pharmacological actions including beta-receptor blockade, central effects and membrane stabilizing effects, and it may be antagonized by intrinsic sympathomimetic activity and the reduction in afterload for the heart. Vascular beta-receptor blocking action may play a part in decreasing the degree of reduction of the total peripheral resistance index, while their intrinsic sympathomimetic action on the vascular site may induce vasodilating effects.

Acebutolol↗
PubMed1982

Plasma pancreatic glucagon in pancreatic and primary diabetes, and liver cirrhosis: application of a correction to the radioimmunoassay for pancreatic glucagon.

Evidence is present that plasma contains non-specific factors which interfere with the 30K glucagon assays. A correction can be made for these interference factors because the factors can be quantitated following absorption of glucagon with charcoal-dextran. Using a correction factor the range of fasting plasma immunoreactive glucagon (IRG) in 12 totally pancreatectomized patients was below detectable limit. Fasting levels of IRG were determined on the plasma from 25 liver cirrhotics complicated by abnormal GTT, 13 pancreatic diabetics with chronic calcified pancreatitis (CCP), 25 adult-onset primary diabetics and 25 healthy subjects. When all samples were measured using no correction factor, the mean levels of IRG were 358 +/- 24 (mean +/- SE), 170 +/- 26, 178 +/- 16 and 178 +/- 7 pg/ml, respectively. Using a correction factor the mean level of IRG were 177 +/- 26, 16 +/- 4, 39 +/- 9 and 20 +/- 4 pg/ml, respectively. The mean values of the interference factor were not significantly different among all five groups. During an arginine infusion the interference factor remained unchanged despite an increase in IRG. It is available but not always necessary to apply a correction factor for 30K glucagon radioimmunoassay.

Aged↗
PubMed1982

Significance of the automaticity recovery phase following tachycardic overdrive.

The usefulness of automaticity recover time (ART) and automaticity recovery phase (ARP; the time requiring P-P cycles to return to the original P-P cycles following the termination of tachyarrhythmias) for evaluating the sinus node function was studied in 24 patients with tachyarrhythmias by recordings of 24-hour continuous electrocardiograms. Automaticity recovery time was not so valuable in evaluating sinus node function because the overlap of ART was observed between patients of normal sinus node function and patients with sick sinus syndrome. The pattern of ARP was classified into 4 types (I--IV). Type I showed qUick return to the original P-P after overdrive suppression, type II was characterized by first suppression and secondary acceleration, type III was the pattern characterized by repeated suppression after tachycardiac overdrive, and type IV was characterized by repetitive appearance of tachyarrhythmia and bradycardia. The period of each ARP was measured and the period of type II (42.2 +/- 16.6 sec) or III ARP (48.4 +/- 21.4 sec) was significantly longer than type I (22.1 +/- 11.1 sec). Type III ARP was considered to suggest sinus node dysfunction. In conclusion, it was suggested that not only the observation of ART but also ARP were valuable for evaluating more precise sinus node function. The observation of ARP is easily obtained from 24-hour continuous recordings of electrocardiograms.

Adolescent↗
PubMed1982

Observations of the effect of arrhythmias on the cerebral function by recordings of 24-hour continuous electrocardiograms. Comparison between the sick sinus syndrome and atrio-ventricular block.

The influence of arrhythmias on cerebral function was investigated in 8 patients with sick sinus syndrome (bradycardia tachycardia syndrome) and 8 patients with advanced or complete atrioventricular block using 24-hour continuous recordings of the electrocardiogram and conventional electroencephalogram recordings. Syncope was observed more frequently in the atrio-ventricular block group, and was observed frequently when the longest heart beat pause during a 24-hour day was longer than 2.2 sec. Cerebral infarction as a complication of these arrhythmias was observed only with the sick sinus syndrome group. The maximum heart rate during a 24-hour day and the difference between maximum and minimum heart rate were significantly lower in the atrioventricular block group than in the sick sinus syndrome group. The electroencephalogram results showed a slight slowing of the background activity and the appearance of slow wave bursts in both groups. These abnormal findings were improved during intracardiac pacing in the atrio-ventricular block group. A quantitative analysis of the frequency of the electroencephalogram at various heart rates demonstrated the optimum pacing rate for the cerebral function. These results suggest that both the cerebral function and the cardiac function must be considered in the treatment of patients with bradycardia arrhythmias.

Adult↗
PubMed1982

Sleep and night-type arrhythmias.

The relationship between arrhythmias and sleep states was investigated in patients with night-type arrhythmias, which were detected by 24-hour electrocardiogram recordings using the Holter Avionics system. These patients were examined using all-night polygraphic recordings and sleep states were divided in to 5 groups according to the standard sleep stage scoring manual as stage I, II, III, IV, and REM sleep. Patients were divided into 5 groups: (1) grade 2 ventricular premature contractions (VPCs), (2) grade 4a VPCs, (3) grade 4b VPCs, (4) supraventricular premature contractions, and (5) paroxysmal tachyarrhythmias such as paroxysmal atrial fibrillation or paroxysmal supraventricular tachycardia. The paroxysmal tachyarrhythmia group showed a significant increase in arrhythmia incidence during REM sleep (p less than 0.05). However, the subjects with other arrhythmias showed no significant increase during REM sleep, but grade 2 VPCs showed a tendency to increase in sleep stage IV (0.05 less than p less than 0.1). These results suggest that there are 2 types of arrhythmias influenced by sleep. The first type is affected by a phasic increase in sympathetic nervous tone during REM sleep and the second type is related to an increase in vagal tone during the night.

Adolescent↗