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Biomedical subjects

M Okawa

Publications and source records attributed to M Okawa.

At least 91 records · Page 5Linked to original sources
PubMed1997

Vitamin B12 treatment for delayed sleep phase syndrome: a multi-center double-blind study.

The active form of vitamin B12 (methylcobalamin) has been reported to be effective on sleep-wake rhythm disorders. Previous studies, however, were performed under open trial, and the effect of vitamin B12 has not been properly evaluated. The aim of this double-blind study was to investigate the efficacy of methylcobalamin on delayed sleep phase syndrome (DSPS). Methylcobalamin (3 mg/day) or placebo was administered for 4 weeks. The subjects were 50 patients with DSPS aged 13-55 years (26.8 +/- 1.3), 27 of whom received the active drug while 23 received the placebo. No significant differences were observed between the 2 groups in subjective evaluations of mood or drowsiness during the daytime or in night sleep by sleep-log evaluation. These results indicate that 3 mg methylcobalamin administered over 4 weeks is not an effective treatment for DSPS.

Adolescent↗
PubMed1997

[Antinuclear antibody screening by an enzyme-linked immunosorbent assay using multiple nuclear antigens].

We assessed the clinical value of an enzyme-linked immunosorbent assay (ELISA) kit (MESACUP ANA, MANA) which uses multiple nuclear antigens for screening antinuclear antibody (ANA). Since the screening procedure for ANA by the indirect fluorescence method (FANA) requires trained personnel and gives rather subjective results, development of a suitable screening test for ANA by ELISA which uses specific nuclear antigens has been long awaited. Serum samples from 350 patients with connective tissue diseases (CTD), and from 300 normal subjects were assayed for ANA by ELISA and the results were compared with those of FANA and of single-antigen ELISAs for RNP, Sm, SS-A, SS-B, Scl-70, Jo-1, dsDNA, and ssDNA. For discrimination between patients with systemic lupus erythematosus and normal subjects, the sensitivity, specificity and accuracy for MANA were 85.7%, 97.5%, and 91.6%, and those for FANA were 95.8%, 77.0%, and 86.4%, respectively. Analysis of CTD sera showing discordant results between FANA and MANA using single-antigen ELISAs revealed that FANA - MANA + sera (n = 8) contained antibodies against SS-A (n = 1) or dsDNA (n = 3) or ssDNA (n = 3), and that some FANA + MANA - sera (n = 82), which were frequently found in RA patients (43/98, 43.9%), also contained antibodies against RNP (n = 3) or ssDNA (n = 13). MANA + normal sera (n = 9) were found to contain antibodies against SS-A (n = 1) or dsDNA (n = 1) or ssDNA (n = 2). In conclusion, MANA was found to be objective, much less labor intensive and suitable for screening large numbers of CTD sera for disease-specific ANAs.

Antibodies, Antinuclear↗
PubMed1996

Effects of a small dose of triazolam on P300 and resting EEG.

The aim of the present study was to clarify whether cognitive impairments caused by benzodiazepines (BDZs) are a consequence of their specific direct effects on cognitive function or whether they are explained as secondary effects of increased sleepiness. Ten healthy men (mean age, 33.9 years) participated in two experimental sessions in a randomized cross-over, double-blind study: in one session subjects were given a placebo and in the other they were given 0.125 mg triazolam (TRZ). Each experimental session was conducted on 1 day. After a pre-drug EEG recording and an event-related potential (ERP) recording, under an oddball paradigm, subjects took the TRZ or placebo orally at 1000 hours. Thereafter, EEG and ERP recording sessions, following the same procedure as the pre-drug sessions, were conducted at 1, 2, 4, 6 and 8 h after drug administration. The EEG and ERP recordings from Cz and Pz referred to the bilaterally linked ear electrodes were used. We found that P300 latency was significantly prolonged in TRZ condition at 2 h (Pz) and 4 h (Cz and Pz) after TRZ, and that the P300 amplitude was significantly reduced at 2 h (Cz and Pz) and 4 h (Pz) after TRZ, compared to the same times after placebo. The absolute power values for the theta (4-7 Hz), alpha 1 (8-9 Hz), and alpha 2 (10-12 Hz) bands did not differ at any measurement time between the treatments. Only the beta band (13-19 Hz) power value was significantly elevated after the TRZ administration (versus placebo). No significant sedative effects were detected in subjective measurements. These results indicate that a single oral dose of 0.125 mg TRZ caused cortical changes without distinct general sedation or subjective sleepiness.

Adult↗
PubMed1996

Delayed phase jumps of sleep onset in a patient with non-24-hour sleep-wake syndrome.

We studied a 30-year-old man with non-24-hour sleep-wake syndrome. To investigate the relationship between environmental light-dark cycles and his sleep-wake rhythm, we documented his sleep log and rectal temperature data without any therapeutic interventions. We found that 1) the patient's sleep-wake pattern consisted of two different components, appearing alternatively, with a period of 27.2 days: regular free-run (R free-run), consisting of a daily 30- to 60-minute regular delay of sleep onset; and jumping free-run (J free-run), with clusters of delayed (> 4 hours) phase jumps in sleep onset (DP jump): 2) the frequency of sleep onset was higher during late evening hours to midnight hours than in the daytime; 3) DP jumps occurred exclusively when the prior sleep onset was delayed into the daytime; and 4) a cluster of DP jumps was likely to start when the patient's low temperature zone (a period in which rectal temperature was below average) at subjective night was illuminated by sunlight. These results suggest that DP jumps in the patient may occur due to illumination of the delay portion of the phase-response curve.

Adult↗
PubMed1996

A multicenter study of sleep-wake rhythm disorders: clinical features of sleep-wake rhythm disorders.

A multicenter study of sleep-wake rhythm disorders (i.e. non-24 hour sleep-wake syndrome; non-24), delayed sleep phase syndrome (DSPS), irregular sleep-wake pattern (irregular sleepers), and long sleepers, was conducted with the co-operation of 25 institutions. One hundred and twenty-one primary sleep-wake rhythm disorders were diagnosed and were classified as 13 non-24, 90 DSPS, 12 irregular and six long sleepers. The mean onset age was about 20 years old and psycho-social factors associating the onset of the disorder were identified in 36% of these patients. The major factors of sleep-wake disorders were personal relationships, advancing to a higher level education, gaining employment, and changes in environment. Most patients were 'night active' prior to appearance of their symptoms. Increase in night activities of modern society seem to result in the occurrence of such sleep-wake rhythm disorders.

Adult↗
PubMed1996

A multicenter study of sleep-wake rhythm disorders: therapeutic effects of vitamin B12, bright light therapy, chronotherapy and hypnotics.

One hundred and six subjects with primary sleep-wake rhythm disorders [13 non-24 hour sleep-wake syndrome (non-24), 76 delayed sleep phase syndrome (DSPS), 11 irregular sleep-wake pattern (irregular) and six long sleepers] were treated with vitamin B12, bright light, chronotherapy and/or hypnotics. These therapies caused moderate or remarkable improvement in 32% of the non-24, 42% of DSPS, 45% of irregular and 67% of long sleepers. A lack of adequate sleep, unpleasant feelings at waking and daytime drowsiness were also improved in DSPS.

Adolescent↗
PubMed1996

Seasonal variation of mood and behaviour in a healthy middle-aged population in Japan.

A population survey of seasonality in six representative cities in Japan was conducted using the Japanese version of the Seasonal Pattern Assessment Questionnaire (SPAQ). The questionnaires were given to 951 parents (male: female ratio 1:1 age range 34-59 years) of high-school students. Significant regional differences in seasonal variations of mood, length of sleep, and weight were observed; the proportion of individuals reporting high seasonality in the two northern cities was significantly higher than that in the other areas. These results provide evidence for a northern predominance in the prevalence of seasonal affective disorder in Japan.

Adult↗
PubMed1996

On the EEG component waves of multi-infarct dementia seniles.

Component waves of EEGs led from the F3-A1, C3-A1, O1-A1, and O2-A2 scalp regions of 24 multi-infarct dementia seniles (MID) patients (ages 58 to 85 years, average 73.3 years) and eight to 19 normal, healthy, adult (NA) subjects were obtained by autoregressive component analysis. Some differences in the component waves were demonstrated between the two groups of subjects. (1) The characteristics of the EEG component waves, including the natural, damping, and resonance frequencies, their power, regularity, etc. were determined, and compared between MID patients and NA subjects. (2) No significant difference was found between male and female patients in the occurrence rate of 11 types of component waves. (3) On the average, the alpha wave frequency was lower in MID patients. (4). Slow alpha waves (7.5 to 9.4 Hz) of MID patients were superior to those of NA subjects, whereas typical alpha waves (9.5 to 11.4 Hz) were inferior to those of NA subjects. (5) The power of alpha waves in the F3-A1 and C3-A1 regions of MID patients was superior to that of NA subjects, whereas the result was reversed in the O1-A1 and O2-A2 regions. However, there was less regularity of alpha waves in all regions among MID patients. (6) The theta wave frequency in all regions was higher in MID patients than in NA subjects. (7) Both the power and regularity of theta waves of MID patients were superior to those of NA subjects in all regions. (8) The average number of delta waves that appeared in the O1-A1 and O2-A2 regions was larger in MID patients than in NA subjects. EEG were led from the F3-A1, C3-A1, O1-A1, and O2-A2 scalp regions of multi-infarct dementia seniles (MID) patients, who had sleep disorders, such as reversed day-time sleep patterns or irregular sleep-wake patterns, frequently accompanied by behavior disorders, such as wandering, violent behavior, and/or delirium. Examination by the method of EEG pattern discrimination revealed some differences in EEG component waves in comparison with normal, healthy, adult (NA) subjects.

Adult↗
PubMed1996

Favorable effect of transcranial electrostimulation on behavior disorders in elderly patients with dementia: a double-blind study.

The efficacy of transcranial electrostimulation for sleep-wake and behavior disorders in elderly patients with dementia was tested in a double-blind study. The subjects were 27 inpatients with multi-infarct dementia (12 males and 15 females, aged 58-86). They were randomly divided into two groups: active treatment (n = 14) and placebo treatment (n = 13). For electrostimulation, a device (HESS-100) was used which delivered repetitive rectangular electric pulses of 6-8 V at increasing frequencies from 6 to 80 Hz, each pulse lasting 0.2 ms and with a root mean square value of 256-530 microA. Electrostimulation was performed for 20 minutes from 10:00 h every morning. The active or placebo treatment was performed for 2 weeks in each group. The electrostimulation was significantly effective in behavior disorders such as wandering or nocturnal delirium, and decreased motivation during the daytime. It was also effective in improving night sleep. Electroencephalograms confirmed increased vigilance levels in the daytime both during and after the treatment.

Aged↗
PubMed1996

Prolonged interval from body temperature nadir to sleep offset in patients with delayed sleep phase syndrome.

In order to clarify the relationship between sleep-wake and core body temperature rhythms in the delayed sleep phase syndrome (DSPS), we conducted simultaneous monitoring of these rhythms in seven patients with DSPS and nine healthy control subjects for 6-10 days during their conventional sleep-wake schedules. The sleep onset and offset times were determined visually from sleep logs, and the temperature data were fitted to 24-hour cosinor curves by the least squares method. The sleep onset and offset times and temperature nadir were delayed significantly in patients with DSPS compared with the control subjects (p = 0.01, 0.003 and 0.02, respectively). We also found that sleep length and the temperature nadir to sleep offset interval were significantly longer in the DSPS than the control group (p = 0.03 and 0.02, respectively). The latter finding suggests that the inability of the patients with DSPS to normally phase-advance their circadian rhythm may be a consequence of masking of the advance portion of their phase-response curve by the last hours of their prolonged sleep episodes.

Adult↗
PubMed1995

Effects of vitamin B12 on human circadian body temperature rhythm.

To clarify the effect of vitamin B12 on the human circadian clock, five healthy male adults participated in two constant routine procedures, 2 or 3 weeks apart. In one, subjects received intravenous saline injections (placebo trial) and in the other, intravenous injections of methylcobalamin (MB12) (drug trial). Intravenous administration of MB12 increased rectal temperature in the later hours of the daytime during the constant routine. The activity did not change between treatments in any period during the constant routine. During the later hours of the constant routine, alertness assessed with visual analog scale was higher in the drug trial than in the placebo trial. The period in which drug treatment produced greater alertness almost coincided with that in which MB12 elevated rectal temperature. These results may provide evidence of an effect of vitamin B12 on the circadian clock.

Adult↗
PubMed1995

Enzymatic synthesis of mannobioses and mannotrioses by reverse hydrolysis using alpha-mannosidase from Aspergillus niger.

Various manno-oligosaccharides including alpha-D-man-(1 --> 2)-D man and alpha-D-man-(1 --> 2)-alpha-D-man-(1 --> 2)-D-man were formed when a highly concentrated mannose solution was incubated in the presence of alpha-mannosidase from Aspergillus niger. alpha-D-Man-(1 --> 2)-D-man and alpha-D- man-(1 --> 2)-alpha-D-man-(1 --> 2)-D-man were isolated by activated carbon chromatography followed by high performance liquid chromatography using an amino-silica column. In addition to the above oligosaccharides, alpha-D-man-(1 --> 3)-D-man, alpha-D-man-(1 --> 6)-D-man, and alpha-D-man-(1 --> 2)-alpha-D-man-(1 -->6)-D-man were also isolated.

Aspergillus niger↗
PubMed1995

Incidental Lewy body disease in a patient with REM sleep behavior disorder.

We studied an 84-year-old man with a 20-year history of nocturnal violent behavior during sleep, but no other clinically evident neuropsychiatric disorders. Polysomnographic investigations confirmed that he suffered from REM sleep behavior disorder (RBD). Histopathologic examination revealed he had Lewy body disease with a marked decrease of pigmented neurons in the locus ceruleus and substantia nigra. These histologic findings represent the first documented evidence of a loss of brainstem monoaminergic neurons in clinically idiopathic RBD and suggest that Lewy body disease might provide an explanation for idiopathic RBD in the aged.

Aged↗