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Biomedical subjects

T Tsujimoto

Publications and source records attributed to T Tsujimoto.

At least 73 records · Page 4Linked to original sources
PubMed1992

Circadian rhythm abnormalities of deep body temperature in depressive disorders.

We investigated circadian rhythms of body temperature in 62 inpatients with major depressive episodes, by monitoring the deep body temperature through the abdominal skin every two hours for a consecutive 48-h period. The data were analyzed by both the least-squares method and the maximum entropy spectral analysis (MEM) and were compared with those in 29 normal volunteers who apparently had a regular 24-h sleep-wake schedule. Circadian rhythm phase disturbances in the depressed patients were likely to be manifested in a phase normal or a phase delay pattern rather than in a phase advance pattern. The amplitude of body temperature was significantly smaller and the mesor was higher in the depressed patients than in the normal subjects. Analysis by MEM revealed that the periods of circadian rhythm of body temperature tended to be longer in the depressed patients than in the normal subjects, though there was no significant difference. The power spectral density by MEM was significantly lower, and there were significantly more ultradian rhythm components in the depressed patients than in the normal subjects. These findings suggest that the fundamental rhythm disturbance in depression may be a weakening of the coupling processes between internal pacemakers and an abnormal sensitivity to environmental information.

Adult↗
PubMed1992

[Drug-induced psychiatric disturbance by lidocaine].

Lidocaine is widely used as an antiarrhythmic agent. One of the side effects of lidocaine is disorientation. Measurement was made of the plasma level of lidocaine in twelve consecutive cases. Lidocaine infusion had been given to these cases for more than twenty-four hours. Measurements were then made of the frequency of psychiatric disturbance. Psychiatric disturbances were recognised in six cases and the plasma levels in four cases among them were more than 5 micrograms.ml-1. The psychiatric disturbances disappeared within three hours after the cessation of lidocaine infusion. When disorientation occurs in a patient who receives lidocaine treatment, drug-induced psychiatric disturbance should be suspected.

Female↗
PubMed1991

[Anesthesia for combined carotid endarterectomy and coronary artery bypass grafting].

The anesthesia for combined carotid endarterectomy (CEA) and coronary artery bypass grafting (CABG) is mentioned in this report. Although electroencephalogram was set up to detect the sign of brain ischemia during surgery, it became unreliable because of electrical noise from the medical instruments. Another monitoring method, such as trans-cranial Doppler, was thought to be needed to avoid the electrical noise. In anesthesia, a gradual measured induction with judicious fluid loading was imperative along with a protection from the reflex response to pain stimuli. Thiopental was used to protect the brain from ischemic injury during CEA. The perfusion pressure during cardiopulmonary bypass was maintained at 55-65 mmHg, and no neurological complication was seen.

Aged↗
PubMed1991

Isolation and fundamental characteristics of a phospholipase B inhibitor from autolyzed Torulaspora delbrueckii.

Phospholipase B inhibitor was found in the autolyzate of yeast cells, Torulaspora delbrueckii. The inhibitor was purified to homogeneity by ethanol precipitation, gel filtration with Sephadex G-10, ion-exchange chromatography with DEAE-Sephacel, and gel filtration with Asahipak GS-320. On thin-layer chromatography the purified inhibitor was detected with the Hanes-Isherwood reagent, which is used to detect phosphorus. The activity of the inhibitor was not affected by heat treatment at 100 degrees C for 1 h. Heating at 100 degrees C for 1 h in 1 M HCl and 1 M NaOH lowered activity to 76 and 80% of the original values, respectively, but heating at 110 degrees C for 24 h in 6 M HCl completely abolished activity. The inhibitor was highly soluble in water, but practically insoluble in alcohol, acetone, ether, and chloroform. The degree of inhibition of enzyme activity was not proportional to the concentration of inhibitor. The inhibitor inhibited both membrane-bound and water-soluble phospholipase B activity from T. delbrueckii at the same level; however, the inhibitor did not inhibit the activity of phospholipase A2 from snake venom (Naja naja).

Chemical Precipitation↗
PubMed1991

[A case of severe near-drowning: the speech ability was regained on the 65th hospital day].

A 3 y.o. boy suffered cardiac arrest after submersion in a winter pond for more than fifteen minutes. He was transferred to our hospital and was successfully resuscitated. Although his neurological condition was severely damaged at the beginning, he started searching objects with his eyes on the 18th hospital day, speaking on the 65th hospital day and walking by himself on the 76th hospital day. His consciousness fully recovered eventually. The treatments consisted of "HYPER" as suggested by Conn AW, et al. and active anti-hypertensive therapy. These treatments and the cold temperature of winter time might have contributed to the good neurological recovery of the patient.

Child, Preschool↗
PubMed1991

[A case of sinus arrest during a surgical operation].

A 75-year old obese female was scheduled for mastectomy due to breast tumor. At the preoperative examinations, she had premature atrial contraction on electrocardiogram. But she had no clinical signs or symptoms regarding sick sinus syndrome. She was evaluated as ASA risk II and arranged for neuroleptanesthesia. During the operation, she developed severe bradycardia and asystole lasting for 7 seconds, which was not effectively controlled by atropine sulfate. Then cardiac rhythm resumed spontaneously and she recovered with no neurological deficits. On the postoperative examination of 24 hr-Holter ECG, she showed bradycardia and sinus arrest and she was diagnosed to have sick sinus syndrome.

Aged↗
PubMed1990

Cortical field potential associated with hand movement on warning-imperative visual stimulus and cerebellum in the monkey.

Latent time of the hand movement in response to a visual stimulus was found to be very short when a monkey was enough trained with a visual imperative stimulus preceded by a visual warning stimulus at a fixed time interval. Cerebellar hemispherectomy scarcely prolonged the reaction time of the warning-imperative, visually initiated (W-VI) movement in contrast to its marked delaying action upon the simple visually initiated reaction-time (S-VI) movement. Between the warning and imperative stimuli, sustained surface-negative, depth-positive field potentials were recorded in various areas of the prefrontal and premotor cortices and the supplementary motor area of both cerebral hemispheres, besides gradually increasing surface-negative, depth-positive deflections in the motor and somatosensory cortices contralateral to the moving hand. These observations suggest that the sustained activities in the prefrontal and premotor cortices elicited by the warning stimulus overcome deficiency of the cerebellar function for performing fast and stable timing movements.

Animals↗
PubMed1990

Cortical field potentials associated with hand movements triggered by warning and imperative stimuli in the monkey.

Monkeys were trained to move the hand in response to imperative visual stimulus (IS) given 1 s after warning visual stimulus (WS). With implanted electrodes in the cortices, surface-negative (s-N), depth-positive (d-P) sustained potentials between WS and IS were recorded in the prefrontal, premotor and supplementary motor areas in both hemispheres, and gradually increasing s-N, d-P potentials were seen in the forelimb areas of motor and somatosensory cortices contralateral to the hand. It is suggested that the sustained and gradually increasing potentials are related respectively to cortical activities associated with expectation and anticipation of the IS, and to those with a preparatory process for the movement. The latter appeared to be similar to the case of self-paced movements. These potentials may correspond respectively to the early and late components of CNV in the human.

Animals↗
PubMed1990

Circadian rhythms in depression. Part I: Monitoring of the circadian body temperature rhythm.

In order to develop a sampling strategy and a method for analyzing the circadian body temperature pattern, we monitored estimates of the temperature in four ways using rectal, oral, axillary and deep body temperature from the skin surface every hour for 72 consecutive hours in 10 normal control subjects. Data obtained were analyzed with the least-squares method to estimate the circadian rhythm. Deep body temperature from the skin surface correlated better with rectal temperature than with either oral or axillary temperature in all subjects. The correlation coefficient between rectal and deep body temperature from the skin surface ranged between 0.66 and 0.89. The acrophases calculated from the deep body temperature from the skin surface every 2 h for 48 h were consistent with those based on the rectal temperature every 10 min for 72 h. We believe that monitoring of the deep body temperature from the skin surface, in this manner, at intervals of 2 h for a period of 2 days, is a promising method for investigating circadian body temperature rhythm, because it causes less discomfort than other measures and has greater statistical validity for data computation.

Adult↗
PubMed1990

Circadian rhythms in depression. Part II: Circadian rhythms in inpatients with various mental disorders.

We investigated longitudinally the circadian body temperature rhythms in 65 inpatients with various mental disorders, 38 of whom had major depressive episodes, by estimating the deep body temperature from the skin surface every 2 h for a consecutive 48-h period. To estimate the circadian rhythm, the data obtained were analyzed by the least-squares method and maximum entropy spectral analysis (MEM). Circadian rhythm disturbances in patients with depression were likely to be manifested in phase variability rather than in phase advance. The amplitude of body temperature of the depressed group was significantly less than that of the control group. A positive correlation between the mesor and the severity of the depressive symptoms was found. Moreover, the body temperature of the patients with affective disorders, both in the depressive and in the manic state, tended to fluctuate so much as not only to fit poorly to sinusoid curves, but also to reduce the periodicity of the circadian rhythm. On the basis of these findings, we conclude that the essential feature of the rhythm disturbances in affective disorders is not the phase shift but the instability of the circadian temperature rhythm.

Adult↗
PubMed1990

Terminal sprouting is not responsible for enhanced transmitter release at disused neuromuscular junctions of the rat.

Chronic block of nerve-muscle activity is known to induce sprouting of motor nerve terminals and to enhance transmitter release at the neuromuscular junction. Increased transmitter release has been assumed to be a physiological correlate of disuse-induced sprouting of nerve terminals. We examined this assumption in the rat extensor digitorum longus muscle following chronic conduction block of the sciatic nerve with TTX. The minimal period of nerve block required for the expression of terminal sprouting was 3 d, whereas transmitter release, measured by the quantal analysis of end-plate potentials, was already enhanced within 24 hr of nerve block. Following 6 d of nerve block, sprouting was observed in about 35% of the motor nerve terminals examined. Under this condition, the total length of individual terminals was significantly greater in the terminals with sprouts than those without sprouts. However, enhancement of transmitter release occurred uniformly at these junctions regardless of the presence or absence of terminal sprouts. Also, transmitter release enhanced by nerve block for 2 d remained elevated for at least 4 d even after resumption of nerve activity without the formation of terminal sprouts. It is concluded that terminal sprouting and increased transmitter release induced in disused neuromuscular junctions are not causally related and that the signals for inducing these 2 events are at least quantitatively different.

Animals↗
PubMed1989

Suppression of visually initiated hand movement by stimulation of the prefrontal cortex in the monkey.

Five adult monkeys (Macaca fuscata) were trained for the go/no-go hand movement task with discrimination between two different color stimuli. The go stimulus was accompanied by a reward when a monkey lifted a lever by wrist extension within the stimulus duration (500 ms). Whereas the no-go stimulus was not. The monkey revealed the potential specific to the no-go response in the prefrontal cortex, called 'no-go potential', i.e. surface-negative, depth-positive deflexions in the cortex of the dorsal bank of the principal sulcus and of the rostroventral corner of the prefrontal region. Effects of electrical stimulation of these prefrontal areas upon the go response were observed and analyzed in order to study functional significances of the no-go potential. The surface and depth (2.0-3.0 mm) electrodes chronically implanted respectively in various cortical areas of both hemispheres, originally used for recording cortical field potentials, were utilized for bipolar stimulation of the cortical area. A train of brief electrical pulses was delivered to the loci producible of the no-go potential at different times after the onset of go visual stimulus. The stimulation suppressed the go movement by cancelling and delaying. The grade of the suppressor effect depended on the timing of electrical stimulation after the onset of visual stimulus, and was maximal at around the time of appearance of the no-go potential. The suppressor effect was compared with that produced by stimulating some other areas in the prefrontal cortex and the premotor cortex, and was found rather unique in those areas producible of the no-go potential.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1989

Morning and evening adrenocortical responses to ACTH stimulation in endogenously depressed patients: a preliminary report.

Adrenocortical stimulation with ACTH both in the morning (M-test) and in the evening (E-test) and the dexamethasone suppression test were carried out in patients suffering from endogenous depression (DEP) and normal controls (NOR). A greater cortisol release in DEP was recognized than in NOR in the M-test, an earlier peak response of DEP was shown in the M-test than in the E-test, and a lack of association between hypersecretion of cortisol during depression and cortisol output after ACTH administration was noted. These findings, together with the results of DST, suggest that excessive activity of the hypothalamic-pituitary-adrenal (HPA) axis in depression may result, partly, from adrenocortical hyperresponsiveness.

Adrenocorticotropic Hormone↗
PubMed1988

Chronic administration of tricyclic antidepressants suppresses hypothalamo-pituitary-adrenocortical activity in male rats.

The effect of chronic administration of the clinically effective antidepressants, imipramine, clomipramine and desipramine, on corticosterone (CS) release in male rats was investigated. Chronic administration of imipramine, clomipramine and desipramine at a dose of 20 mg/kg b.w./day, but not at a dose of 2 mg/kg b.w./day, suppressed blood CS concentration at 2000h and abolished its circadian rhythm. The normal circadian rhythm of CS release resumed seven days after the termination of imipramine injection. The acute administration of imipramine (20 mg/kg b.w./day) at 0800h but not at 2000h elevated CS concentrations. Chronic administration of imipramine (20 mg/kg b.w./day) tended to increase the inhibitory effect of dexamethasone on CS release. Adrenocortical sensitivity to exogenous adrenocorticotropic hormone tended to be decreased by chronic administration of imipramine (20 mg/kg b.w./day). These results indicate that antidepressants have effects on the hypothalamo-pituitary-adrenocortical axis which may confound psychoneuroendocrinological tests, such as the dexamethasone suppression test, for the diagnosis of affective disorders.

Adrenal Cortex↗