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Biomedical subjects

K Seto

Publications and source records attributed to K Seto.

At least 217 records · Page 12Linked to original sources

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↗

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↗

Influence of repeated cold exposures on adrenocorticoid formation in rabbits with lesioned limbic-hypothalamic system.

Experiments were carried out in the rabbit, with view to elucidating the role of limbic-hypothalamic system in the adrenocortical responses to repeated cold exposures. In each sham-lesioned group, in the rabbit with lesioned in bilateral stria terminalis and dorsal fornix, the formation of adrenocorticoids in adrenal was markedly increased by 1st cold exposure (cold exposure on 1st day), with the adrenocortical responses to 1st cold exposure being nearly the same in these groups. The bilateral lesions in periventricular arcuate nucleus and ventromedial hypothalamus decreased the adrenocortical responses to 1st cold exposure. In each sham-lesioned group, and in the rabbits with lesioned in bilateral periventricular arcuate nucleus, ventromedial hypothalamus and dorsal fornix, there were no effects of 7th cold exposure (cold exposure on 7th day) on the formation of adrenocorticoids. However, in the rabbits with lesioned in bilateral stria terminalis, the formation of adrenocorticoids was markedly increased by the 7th cold exposure. From these results it might be suggested that periventricular arcuate nucleus and ventromedial hypothalamus participated to adrenocortical response to 1st cold exposure, and the amygdala-stria terminalis system played some role in the establishment of adaptation to repeated cold exposures in adrenocortical responses.

Adrenal Cortex↗

Effect of acupuncture on adrenocortical hormone production in rabbits with a central lesion.

A study was made of adrenocortical hormone production under electroacupuncture stimulation of the Tsu-San-Li locus in rabbits with a lesion in the fornix, stria terminalis, ventromedial nucleus or arcuate nucleus. In rabbits with a lesion in the stria terminalis or ventromedial nucleus, electroacupuncture stimulation of Tsu-San-Li resulted in no increase in phase 1 but an increase in phase 2 of adrenocortical hormone production. In rabbits with a lesion in the fornix or arcuate nucleus electroacupuncture stimulation of Tsu-San-Li was followed by increased adrenocortical hormone production in the both phases. These results show that the stria terminalis and the ventromedial nucleus play a major role in the augmentation of adrenocortical hormone production by electroacupuncture stimulation of Tsu-San-Li.

Acupuncture Therapy↗

Effects of acupuncture on the citrate and glucose metabolism in the liver under various types of stress.

A study was made of the effect of acupuncture on citrate and glucose metabolism in the liver in terms of incorporation of 14C-1, 5-citric acid and 14C-u-glucose in some metabolites. The effect of acupuncture on citrate metabolism in the liver under control conditions was such as to increase production of G and reduce that of KB, FC and FFA. No effect of acupuncture on glucose metabolism in the liver under such conditions was observed. Both citrate and glucose metabolism were affected to a marked extent by immobilization stress or exposure to heat or cold. The deleterious effect of these types of stress was less prominent in animals receiving acupuncture at the Tsu-San-Li locus than in those treated otherwise or receiving no treatment.

Acupuncture Therapy↗

Effect of acupuncture on adrenocortical hormone production: I. Variation in the ability for adrenocortical hormone production in relation to the duration of acupuncture stimulation.

The effect of acupuncture on adrenocortical hormone production in adult female albino rabbits of New Zealand strain was investigated. There was significant increase compared to the control cortisol and corticosterone following application of acupuncture at the locus Tsu-San-Li. In the non-locus group, such treatment resulted in only a transient raise followed by a significant fall in cortisol and corticosterone. Acupuncture treatment with electric current for 1 hour proved to be unique in that it gave rise to no biphasic change in the 14C uptake of the steroids. These results indicate that adrenal production of corticosterone and cortisol was enhanced by acupuncture and electroacupuncture at the Tsu-San-Li locus.

Acupuncture Therapy↗