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Biomedical subjects

Y Motohashi

Publications and source records attributed to Y Motohashi.

At least 55 records · Page 3Linked to original sources
PubMed1993

Effects of 24-hour shift work with nighttime napping on circadian rhythm characteristics in ambulance personnel.

Forty-two ambulance personnel engaged in a 24-h shift system participated in a chronobiological field study to study the effects of 24-h shift work on circadian rhythm characteristics. Autorhythmometry of circadian rhythms of oral temperature, right and left grip strengths, and heart rate plus subjective assessment of drowsiness, fatigue, and attention was performed every approximately 4 h except during sleep for 7 days. Cosinor and power spectral analyses were applied to the longitudinal data of each individual. Changes in circadian period different from 24 h of oral temperature, grip strengths, and heart rate plus subjective drowsiness, fatigue, and attention were observed in ambulance personnel. The incidence of circadian periodicity different from 24 h in oral temperature and right and left grip strength was 28.6%, 35.7%, and 47.6%, respectively. The incidence was relatively lower than that of shift workers engaged in a discontinuous 8-h shift system we reported on previously. Working conditions allowing ambulance personnel to nap when not called for emergency (for > 4 h) might contribute to a stabilization of circadian rhythms. Furthermore, long nighttime ambulance service amounting to > 100 min was significantly associated with a high incidence of at least one prominent circadian period among oral temperature and right and left grip strength rhythms different from 24 h. In conclusion, 24-h shift work altered the characteristics of circadian rhythms of ambulance personnel; nighttime naps seemed to have a favorable effect on averting changes in circadian rhythms.

Adult↗
PubMed1992

Alteration of circadian rhythm in shift-working ambulance personnel. Monitoring of salivary cortisol rhythm.

In order to investigate the relationship between internal desynchronization and clinical intolerance to shift work, a set of circadian rhythms including salivary cortisol rhythm were monitored in seven shift-working ambulance personnel. Oral temperature, grip strength of both hands, subjective assessment of drowsiness, fatigue and attention were recorded approximately every four hours except during sleep, for seven days. Self-sampling of salivary cortisol, which was suitable evaluation of endocrine rhythm in field studies, was also tried in this study. cosinor (cosine curve fitting) method and power spectral analysis were used for time series data analysis. The internal desynchronizations between rhythms of physiological variables and sleep-wake cycle were observed in shift-working ambulance personnel. The incidence of internal desynchronization seemed to be higher in intolerant subjects, although the difference between tolerant and intolerant subjects did not reach a statistically significant level. The peak time of salivary cortisol rhythm during a twenty-four hour shift was phase-advanced as intolerant to shift work showed apparently an atypical circadian pattern of salivary cortisol with an abnormal peak at 21.00 h. In this subject, the clinical intolerance to shift work seemed to be associated with internal desynchronization of circadian rhythms. The present study confirmed the internal desynchronization of the circadian rhythm in physiological rhythms like oral temperature and grip strengths, and was in favour of the hypothesis of an internal desynchronization and clinical intolerance to shift work. The clinical implication of impairment of salivary cortisol rhythm remains to be further investigated.

Adult↗
PubMed1992

The impact of the economy on suicide and homicide rates in Japan and the United States.

A time series study of socioeconomic correlates of suicide and homicide in Japan and the USA from 1953 to 1982 revealed cross-national differences. Divorce rates were positively associated with rates of personal violence in the USA but negatively associated with these rates in Japan. Unemployment and female labor force participation also correlated differently with rates of personal violence in the two nations suggesting that different theories may be necessary to account for the variation in rates of personal violence in different societies.

Cross-Cultural Comparison↗
PubMed1992

[Blood coagulation, fibrinolysis and various values of Lansbury's activity index in rheumatoid arthritis patients].

To clarify pathophysiological significance of blood coagulation and fibrinolysis in rheumatoid arthritis (RA) patients with various values of Lansbury's activity index, we analysed by means of the urokinase activated platelet rich plasma thromboelastography. In RA patients, coagulation time (k) and reaction time (r)+k were shorter, maximal amplitude (ma) was larger and lysis time (LT) was longer comparing with those in healthy control. Especially LT and ma showed marked differences between RA patients and control subjects. The mild RA patients whose Lansbury's activity indexes were 0-19% had significant differences from healthy control subjects, in order of LT less than ma less than r+less than k, the probability values were smaller. Significant coefficients of positive correlations with Lansbury's activity index were higher in order of LT greater than LT/k greater than ma x LT. These findings suggested that RA patients had fibrin formation, which had close relations with maximal amplitude (ma) and lysis time (LT) which had positive correlation with Lansbury's activity index.

Activities of Daily Living↗
PubMed1992

[Analysis of blood coagulation and fibrinolysis in rheumatoid arthritis using the urokinase activated thromboelastography].

The urokinase activated thromboelastography is useful for the analysis of blood coagulation and fibrinolysis in rheumatoid arthritis (RA). In 43 RA patients without extraarticular symptoms (mean year old +/- SD = 50.3 +/- 10.9) and 20 healthy control subjects (mean year old +/- SD = 49.5 +/- 13.8, which is not significant), we have examined reaction time (r), coagulation time (k), r+k, maximal amplitude (ma), lysis time (LT) of the urokinase (final density = 85U/ml) activated platelet rich plasma thromboelastography. In RA patients r, k, r+k are shorter, ma is larger, LT is longer than in control subjects. Especially, k, ma and LT are remarkably statistically significant. these findings suggest that most of RA patients have hypercoagulability and/or prolongation of lysis time simultaneously, k, ma and LT are pathophysiologically important.

Adult↗
PubMed1991

Immunohistochemical study of temporal variations in cytochrome P-450 isozymes in rat testis and their modifications by the inductive effects of cadinenes.

Temporal variations in cytochrome P-450 isozymes of rat testis, PB-P-450 (forms of cytochrome P-450 strongly induced by phenobarbital) and MC-P-448 (forms of cytochrome P-450 strongly induced by 3-methylcholanthrene), were investigated immunohistochemically by the avidin-biotin-complex method using specific antibodies against PB-P-450 and MC-P-448 isozymes. Immunoreactivity to both PB-P-450 and MC-P-448 isozymes was observed in Leydig cells. The number of PB-P-450 positive Leydig cells was found to undergo significant time-of-day variation with a peak time of 0000 hours (light phase from 0800 to 2000 hours). Injection of cadinenes (300 mg/kg per day intraperitoneally at 48 and 96 h before sacrifice) induced PB-P-450 isozyme but did not induce MC-P-448 isozyme. The induction of PB-P-450 isozyme by cadinenes was time dependent, and the early dark phase (2000 and 0000 hours) was most sensitive. These results suggest that temporal variation of cytochrome P-450 isozymes is one of the important physiological variations in detoxification and activation of various xenobiotics and chemicals in the testis.

Animals↗
PubMed1991

Effects of socioeconomic factors on secular trends in suicide in Japan, 1953-86.

The effects of socioeconomic factors on secular trends in suicide rates in Japan for the periods 1953-72 and 1973-86 were investigated using twelve socioeconomic indicators. Multiple regression analysis showed that the socioeconomic indicators affecting suicide rates were not identical in the two periods. The rates in both sexes in 1953-72 were closely related to unemployment rate and the labour force but between 1973 and 1986, divorce rate and the proportion in tertiary industry were most influential. The changes reflect the socioeconomic changes in industrial structure in Japan in transition from an industrial to a service economy.

Adolescent↗
PubMed1991

Prediction of end-stage renal disease patient population in Japan by system dynamics model.

A prediction of the end-stage renal disease (ESRD) population in Japan from 1980 to 2000 was made using a system dynamics model based on previously published estimates. It is estimated that the ESRD population will be 145,750 (1111 per million population (pmp)) by the year 2000, if renal transplantation gradually increases and finally reaches 3000 (22.9 pmp) per year by 2000. This number is approximately 1.8-fold greater than the 1987 ESRD population (80,075). On the other hand, the projected number of people with ESRD could be 157,350 (1199 pmp) if the promotion of renal transplantation is unsuccessful until 2000 and the number of renal transplants is 800 (6.1 pmp) per year up to that time. In conclusion, the promotion of renal transplantation requires urgent attention to ensure adequate suppression of any future increase in the ESRD population in Japan.

Adolescent↗
PubMed1990

Circadian variations in trichloroethylene toxicity under a 12:12 hr light-dark cycle and their alterations under constant darkness in rats.

In order to investigate the circadian variations in acute toxicity of trichloroethylene (TRI), TRI (1.2 g/kg weight) or saline was injected intraperitoneally in a total of 88 male Wistar rats at four circadian stages (03.00, 09.00, 15.00, and 21.00:hr.min) under two different lighting regimens of a 12:12 hr light-dark cycle (LD; light from 06.00 to 18.00) and of constant darkness (DD). Circadian variations in TRI toxicity were confirmed in both LD and DD. The toxicity of TRI evaluated by the increase in glutamic-pyruvate transaminase activity (GPT) was greatest when injected at 09.00 in LD while at 21.00 in DD. The increases in blood urea nitrogen, serum total cholesterol and triglyceride concentrations reached peaks when injected at 09.00 in LD and 03.00 in DD. The circadian variations in serum trichloroethanol concentration were very similar to those in GPT in both LD and DD, showing a significant correlation (p less than 0.05). The present study revealed that circadian variations in TRI toxicity existed in LD and that these variations persisted in a free-running condition. The peak phase of TRI toxicity was located in a trough phase (09.00) in LD and in a peak phase (21.00 or 03.00) in DD of temperature rhythm. Thus, the phase relationship changed in DD, showing a desynchronization between TRI toxicity rhythm and temperature rhythm, which is an unusual phenomenon. This means that an unexpected potentiation of TRI toxicity during active phase which is not a critical phase in a well-synchronized state could occur in a free-running condition.

Animals↗
PubMed1990

Growth hormone (GH) and GH-releasing hormone response to ACTH 1-17 at different times of day. Evidence of a circadian stage dependence.

The effect of injection of ACTH 1-17 on the secretion of GH has been examined at three different circadian stages (07, 14 and 21 h) in the winter. Each week for six consecutive weeks the subjects were investigated before and after I.M. injection either of saline (controls) or 100 micrograms ACTH 1-17. Each subject was his own control. The peak plasma concentration of GH was always found 40 min after the injection. The larger absolute increase and the greater AUC curve were seen following the injections at 14.00 h and 21.00 h. The findings could not be attributed to an effect on GH-RH, since secretion of it remained unchanged during the test.

Adolescent↗
PubMed1990

Effect of shift work on the night-time secretory patterns of melatonin, prolactin, cortisol and testosterone.

In a study of the internal desynchronization of circadian rhythms in 12 shift workers, 4 of them, aged 25-34 years, agreed to be sampled every 2 h during their night shift (0000 hours to 0800 hours). They were oil refinery operators with a fast rotating shift system (every 3-4 days). We found marked changes in the secretory profiles of melatonin, prolactin and testosterone. Melatonin had higher peak-values resulting in a four-times higher amplitude than in controls. With respect to prolactin and testosterone, peak and trough times were erratic and the serum concentrations were significantly decreased in shift workers. Serum cortisol presented a decreased rhythm amplitude together with higher concentrations at 0000 hours in shift workers. This study clearly shows that fast rotating shift-work modifies peak or trough values and rhythm amplitudes of melatonin, prolactin, testosterone and cortisol without any apparent phase shift of these hormones. Whether the large rhythm amplitude of melatonin may be considered as a marker of tolerance to shift work, as reported for body temperature and hand grip strength, since it would help the subjects to maintain their internal synchronization, needs further investigation.

Adult↗
PubMed1990

Time-dependent effects of trichloroethylene on motor activity in rats.

Circadian variations in acute and subacute neurobehavioural effects of trichloroethylene (TRI: 1.2g/kg i.p.) were investigated in the rat under a light: dark = 12: 12 hr cycle. An acute effect of TRI evaluated by decreased muscle tone was maximal during the early dark phase (21:00). A subacute effect of TRI was evaluated by a continuous recording of spontaneous locomotor activity in the rat. The circadian rhythm in spontaneous locomotor activity was extensively impaired by the injection of TRI for three consecutive days. Spectral analysis of spontaneous locomotor activity showed that ultradian periods became more dominant than the circadian period, and the 1/f fluctuation of the spectrum disappeared after the injection of TRI. The effect of TRI on the circadian rhythm in spontaneous locomotor activity was circadian-phase dependent, and the treatment of TRI at 09:00 provoked greater circadian rhythm impairment than that at 21:00. The mechanisms of the time-dependent effect of TRI on neurobehaviour are the subject of further investigation.

Animals↗
PubMed1990

Circadian variation in suicide attempts in Tokyo from 1978 to 1985.

Circadian variations in suicide attempts in Tokyo from 1978 to 1985 were analyzed on the basis of records of the Ambulance Service of Tokyo. A significant circadian variation in suicide attempts was demonstrated by the cosinor method, power spectrum analysis (by the maximum-entropy method), and analysis of variance. The peak time for suicide attempts was established by cosinor analysis as about 1800 hours (6:00 P.M.). The circadian variation in suicide attempts seemed to be associated with endogenous rhythms such as mood, as well as with daily variation in social activities.

Adolescent↗
PubMed1990

[A case with reconstruction of the floor of the oral cavity and mandibular region with the D-P flap after resection of giant keloid and radiation scar of the mandibular].

The floor of the oral cavity and mandibular of a 27-year-old female was reconstructed with the D-P flap after resection of a giant keloid in the submandibular region and a radiation scar of the mandibular. The mandibular was reconstructed with a transplantation graft of the iliac bone and the functional properties and appearance were good.

Adult↗
PubMed1990

[Acute myeloblastic leukemia associated with 46, XY, del(5)(q22)].

A 38-year-old male admitted to the Internal Medicine of Surugadai Nihon University Hospital, complaining of general fatigue and throat pain. The laboratory examinations revealed leukocytosis (83, 900/microliters) and an appearance of myeloblasts (90.2%) in the peripheral blood. The nucleated cell count was 56 x 10(4)/microliters with 85.5% myeloblasts in bone marrow. He was diagnosed as acute myeloblastic leukemia (AML). Though he received two courses of combination chemotherapy with daunorubicin, BH-AC, 6 MP and prednisone, one course of combination with mitoxantrone, etoposide and cytosine arabinoside and one course of combination with aclarubicin cytosine arabinoside and prednisone, he could not achieved remission. A chromosome analysis revealed 46, XY del(5)(q22). The amount of DNA fragments hybridized to 4.5 Kb v-fms probe in blastoid cells was approximately a half amount of normal persons. It is not defined the relationship between the decrease of fms and leukemia in this case. He was diagnosed de novo AML, since he had not been received the therapy with potential mutagenic and carcinogenic agents and had not been exposed the irradiation on his works.

Adult↗