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Biomedical subjects

Y Ichimaru

Publications and source records attributed to Y Ichimaru.

66 records · Page 4Linked to original sources
PubMed1983

[Behavioral and electroencephalographic study of 7-chloro-1-methyl-5-phenyl-1 H-1,5-benzodiazepine-2,4-(3H,5H)-dione (clobazam)].

Behavioral and electroencephalographic effects of clobazam (CBZ), a 1, 5 benzodiazepine, were investigated in mice, rats and rabbits and compared with the effects of diazepam (DZP) and chlordiazepoxide (CDP). In EEG studies of rabbits, CBZ, DZP and CDP at doses of 2-10 mg/kg, i.v., caused a drowsy pattern, i.e., high voltage slow waves in the frontal cortex and the desynchronization of hippocampal theta wave. EEG arousal responses induced not only by auditory stimulation but also by electric stimulation of the mesencephalic reticular formation were inhibited by CBZ; CBZ was less potent than DZP, but more potent than CDP. On hypothalamic self-stimulation behavior of rats, low rate responses induced by low current brain stimulation, VI or DRL procedure were increased by oral administration of the three drugs. CBZ was less potent than DZP in the above respondings, but the same potency as CDP in VI or DRL responding and more potent in low rate responding induced by low current stimulation. The preventive effect of CBZ on MES convulsion in mice was less potent than DZP, but 2.5 times as potent as CDP. The preventive effect of CBZ was 1.3 times as potent as DZP and 2.5 times as potent as CDP. CBZ reduced the hyperemotionality of olfactory bulbectomized rats, and this effect was less than DZP in suppressing muricide. The muscle relaxant effect of CBZ in inclined screen and rotarod tests of mice was less than that of DZP. CBZ was 2.2 times as potent as CDP in potentiating thiopental sleep in mice, but less than DZP. These results indicate that CBZ is qualitatively similar to 1, 4 benzodiazepines, DZP and CDP, and is more potent than CDP, but less potent than DZP.

Animals↗
PubMed1983

[Effects of 2-(4-methylaminobutoxy) diphenylmethane hydrochloride (MCI-2016), an omega-aminoalkoxybenzene derivative, on the gastric lesions induced by conditioned emotional stimulus].

Effects of 2-(4-methylaminobutoxy) diphenylmethane hydrochloride (MCI-2016) were studied on gastric lesions induced by conditioned emotional stimulus (CES) in mice. The gastric were produced by the communication box reported by Ogawa et al. The communication box was divided into 48 compartments by transparent plastic walls. Twenty-four mice in each compartment were subjected to footshock through the grid on the floor (sender), and the other 24 mice were not (responder). The mice were subjected to CES for 12 hr. The incidences of the gastric lesions in the responder and sender groups were 72.9 and 98.8%, respectively. MCI-2016 at doses of 20-50 mg/kg (X2), p.o., reduced the incidence of gastric lesions in the responder group; and diazepam at a dose of 2 mg/kg (X2), imipramine at doses of 10 and 20 mg/g (X2), p.o., amitriptyline at doses of 5 and 10 mg/kg, (X2), p.o., and sulpiride 100 mg/kg (X2) reduced the incidences of gastric lesions in the responder group. These findings have indicated that MCI-2016 has an antiulcerative action against gastric erosion induced by CES.

Animals↗
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↗
PubMed1981

Usefulness of 24-hour recordings of electrocardiogram for the diagnosis and treatment of arrhythmias with special reference to the determination of indication of artificial cardiac pacing.

Twenty-four-hour recordings of electrocardiogram (ECG) were obtained from 1528 subjects. Sick sinus syndrome (SSS) was observed in 34 and advanced or complete AV block (CAVB) in 13 subjects. During the period studied 21 patients had died, who showed complicated ventricular premature contractions in 9 (multiform 6, short run 2, repetitive 2). Seventy-three patients with artificial cardiac pacing who were admitted at three different institutions were analyzed. The discrepancy of degree of block was observed between His bundle electrocardiographic findings and 24-hour ECG recordings. In 15 patients there was no correlation between sinus node recovery time following overdrive suppression and pauses following the termination of tachycardia (r = 0.0896, N. S.). In 49 normal subjects 24-hour heart rate ranged from a high of 170 to a low of 36 beats/min. Longest R-R interval ranged from 2.08 to 0.86 sec (mean 1.25 +/- 0.22 sec). The critical level of longest R-R interval to differentiate between normal group and groups with SSS or CAVB was about 1.6 sec. Above results suggest that Holter monitoring permits a precise diagnosis of arrhythmias and that both HBE and Holter monitoring should be used for the determination of pacemaker implantation especially in those with syncope or dizziness but without evidence of marked bradycardia.

Adolescent↗
PubMed1981

[Behavioral and EEG effects of coixol (6-methoxybenzoxazolone), one of the components in Coix Lachryma-Jobi L. var. ma-yuen Stapf].

Coixol (6-methoxybenzoxazolone) contained in Coix Lachryma-Jobi L. var. ma-yuen Stapf was compared with chlorzoxazone with respect to behavioral and EEG effects in mice and rats. Coixol 50-100 mg/kg, i.p. decreased locomotor activities of both species and produced hypothermia in rats. These effects of coixol were the same in potency as chlorzoxazone given in the same dose. Coixol was approximately twice as potent as chlorzoxazone in potentiating thiopental-induced sleep. This compound attenuated the writhing syndrome induced by 1% acetic acid and increased the threshold to jumping response induced by foot shock, to the same degree as seen with chlorzoxazone. Coixol was equipotent to chlorzoxazone in preventing convulsions induced by maximal electro-shock, while it was about 1.5 times more potent than chlorzoxazone in suppressing pentylenetetrazol-induced convulsion. Coixol 20-100 mg/kg inhibited the lever pressing response of hypothalamic self-stimulation in rats. In rats with chronically implanted electrodes, coixol 50-100 mg/kg induced drowsy patterns on the spontaneous EEG. The EEG arousal response to the external auditory stimulation was inhibited by the same doses of coixol, whereas it failed to suppress the arousal response to the midbrain reticular stimulation. These results indicate that coixol has pharmacological properties qualitatively similar to chlorzoxazone and acts as a central muscle relaxant with an anti-convulsant effect.

Analgesics↗
PubMed1979

[Behavioral and EEG effects of Zingiber mioga Roscoe (water soluble fraction) (author's transl)].

Behavioral and EEG effects of water soluble fraction extracted from Zingiber mioga Roscoe (Z. mioga) were investigated in mice, rats and rabbits. Z. mioga was dissolved in isotonic saline and given i.p. into mice and rats, and i.v. into rabbits, respectively. Z. mioga at doses of 50 approximately 400 mg/kf produced a marked reduction in locomotor activity of mice in the open-field test. The peak time of reduction was 30 min after the injection. In mice, Z. mioga at the same doses lowered significantly the rectal temperature and prolonged the sleeping time induced by thiopental-Na (40 mg/kg, i.v.). Z. mioga at a dose of 400 mg/kg had no anticonvulsant effects and it produced a slight muscle relaxation in mice. Z. mioga at doses of 50 approximately 200 mg/kg induced a significant inhibition of the active conditioned avoidance response of the rat in a shuttle box without affecting the unconditioned escape response. In the step-down method, however, the passive conditioned avoidance response was rarely affected by Z. mioga, but the response was suppressed by chlorpromazine. In rabbits with chronically implanted electrodes, Z. mioga at doses of 20--30 mg/kg induced a drowsy pattern of spontaneous EEG, ilel high voltage slow waves in the neocortex and amygdala, and desynchronization in the case of hippocampal theta waves. The EEG arousal response to the external auditory stimulation was inhibited by the same doses of Z. mioga, whereas it failed to suppress the arousal response to either the midbrain reticular or posterior hypothalamic stimulation, as with chlorpromazine. Neither the recruiting response nor the photic driving response were affected by Z. mioga. On the other hand, the limbic after-discharges to the hippocampal or amygdaloid stimulation were enhanced by Z. mioga as well as chlorpromazin, but they were inhibited by diazepam. The EEG effects of Z. mioga were qualitatively similar to chlorpromazine, but not to diazepam. These results indicate the similarity of behavioral and EEG effects of Z. mioga to those seen with neuroleptics such as chlorpromazine.

Animals↗