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Biomedical subjects

Y Motohashi

Publications and source records attributed to Y Motohashi.

At least 19 recordsLinked to original sources
PubMed2001

Diurnal variations in alpha power density and subjective sleepiness while performing repeated vigilance tasks.

OBJECTIVE: Diurnal variations in EEG activity and subjectively rated sleepiness while performing repeated vigilance tasks were examined. METHODS: Nine diurnally active healthy males underwent repeated vigilance tasks at 08:00, 11:00, 14:00, 17:00 and 20:00 h. An electroencephalogram (EEG) was taken while the subjects performed the tasks with their eyes open. The alpha power spectra (8.6-13.3 Hz) of EEG was integrated. Subjectively rated sleepiness, reaction time and oral temperature were also measured. RESULTS: Significant diurnal variations were found for alpha power, subjectively rated sleepiness and oral temperature. The alpha power was significantly smaller at 08:00 than at 11:00, 14:00, 17:00 and 20:00 h. The subjectively rated sleepiness was significantly larger at 08:00 than at 11:00, 17:00 and 20:00 h. The diurnal variation in alpha power did not correspond to that in subjectively rated sleepiness. On the other hand, repeated vigilance tasks increased the alpha power, subjectively rated sleepiness and reaction time at each time of day. The increase in alpha power was significantly greater at 14:00 than at 08:00 and 20:00 h. CONCLUSIONS: The diurnal variation was found in alpha power while performing vigilance tasks. Furthermore, the increase in alpha power with repetition of the task depended on the time of day.

Adult↗
PubMed2001

Changes in postural sway during a period of sustained wakefulness in male adults.

Nocturnal variations in postural sway during a period of sustained wakefulness were studied in seven healthy male adults. Postural sways with the subject's eyes open and with them closed were measured every hour from 22:00 to 04:00 h the following day. Parameters of postural sway [rectangle area (RA), root mean square of length in the anterior-posterior direction (RMSL-y), and medium-frequency-band (0.2-1.0 Hz) power of postural sway in the lateral (MF-x) and anterior-posterior (MF-y) directions] showed significant nocturnal variations. RA, RMSL-y, MF-x and MF-y increased after midnight and reached peaks at 04:00 h. Moreover, changes in RA and MF-y depended on visual conditions. The increases in RA and MF-y were larger with the eyes closed than with them open. These postural sway parameters showed positive correlations with subjectively rated sleepiness and negative correlations with electroencephalographic alpha activity. The results suggest that changes in postural sway during the night are influenced by the increase in sleepiness.

Activity Cycles↗
PubMed2001

Postural sway during cane use by patients with stroke.

OBJECTIVE: To quantitatively evaluate the effects of body support with a cane on postural sway by measuring gravity-center sway of patients with stroke who reside at home. DESIGN: The subjects were 41 patients with stroke and 36 healthy independent elderly people. Each subject stood in the standard Romberg position on a gravicorder under two conditions: without support and with a cane. RESULTS: In both groups, the largest area of gravity-center sway occurred when the subjects stood without support. The area of gravity-center sway of the patients with stroke was significantly greater than that of the healthy independent elderly. In the patients with stroke group, the percentage decrease in the standing position with the cane was 58.0% in the men and 53.9% in the women, as opposed to 67.7% in the men and 67.8% in the women in the group of healthy independent elderly. CONCLUSION: The authors quantitatively evaluated the effects of body support with a cane on postural sway of patients with stroke. The effect of body support with cane on postural sway of patients with stroke was more effective than that of healthy independent elderly.

Aged↗
PubMed2001

Quantitative EEG data and comprehensive ADL (Activities of Daily Living) evaluation of stroke survivors residing in the community.

The purpose of this study was to investigate the hypothesis that EEG values match other comprehensive activities of daily living (ADL) evaluations between stroke survivors and normal controls. Various functions related to ADL were examined by means of ADL assessments (Measurement of Competence in the Elderly Living at Home, Barthel Index, Stroke Impairment Assessment Set, time needed to walk 10 metres) and biosocial synchronization (the questionnaire on biosocial rhythms of daily living). EEG was undertaken using a computer-assisted portable EEG recorder. The power spectra were computed using a fast Fourier transformation analysis (FFT). The absolute and relative powers (percent of the total EEG power) of 5 frequency bands (delta, theta, alpha 1, alpha 2 and beta) and the peak frequency were analyzed. In comparing stroke survivors and the independent elderly, the latter had higher scores than the former in assessments of various functions related to ADL. The absolute and relative power of the delta band were lower in normal controls, and the relative power of the alpha (2) band and the peak frequency were higher than those of stroke survivors. Among the correlations between EEG and ADL assessments, the absolute and relative power of the alpha (2) band correlated significantly with ADL assessments of stroke survivors with right hemiplegia. The peak frequency was significantly increased in cases with high ADL scores. In conclusion, significant correlations were identified between the quantitative EEG data of stroke survivors in the chronic stage, living in the community, and ADL-related functions. Computer-assisted portable EEG recording is a potentially useful screening tool for objectively evaluating the functional levels of stroke survivors in field work.

Activities of Daily Living↗
PubMed2001

NeuroD/beta2 gene G-->A polymorphism may affect onset pattern of type 1 diabetes in Japanese.

OBJECTIVE: The majority of type 1 diabetes is considered to be autoimmune with, for the most part, abrupt development. However, type 1 diabetes with slow onset, or the so-called slowly progressive type 1 diabetes or latent autoimmune diabetes in adults, has been recently recognized and is considered to be autoimmune-related. Although some investigators tried to explain the difference in onset pattern by the genetic background, including HLA type, it has not been established thus far. We hypothesized that the difference in onset pattern may relate to regeneration or differentiation of pancreatic beta-cells, and we therefore focused on the NeuroD/BETA2 gene, which encodes a transcription factor for the insulin gene and beta-cell differentiation. RESEARCH DESIGN AND METHODS: We examined the NeuroD/BETA2 gene polymorphism in 105 Japanese type 1 diabetic patients and in 122 nondiabetic Japanese subjects in a case-control study, and we stratified the patients according to their onset pattern and islet-associated autoantibody positivity. RESULTS: Regardless of the existence of islet-associated autoantibody, we found a significant difference in A allele frequency between type 1 diabetic patients with acute-onset type and control subjects. However, no difference was found between type 1 slow-onset diabetic patients and control subjects. CONCLUSIONS: These results support our hypothesis that NeuroD/BETA2 may affect the ability of regeneration of beta-cells, leading to a difference in the onset pattern and clinical course of type 1 diabetes.

Adolescent↗
PubMed2001

[A case of gastric cancer with liver metastases successfully treated with combination therapy of systemic and hepatic arterial infusion chemotherapy].

A 67-year-old man was admitted to our hospital because of advanced gastric cancer associated with metastases to the liver, the lymph nodes along the lesser curvature and the infradiaphragmatic lymph nodes. As we considered the primary lesion and the liver metastases to be unresectable, we treated him with combination therapy of systemic and hepatic arterial infusion chemotherapy. The regimen of systemic chemotherapy consisted of cisplatin (CDDP) and UFT. Hepatic arterial infusion chemotherapy included 5-fluorouracil (5-FU), doxorubicin (DXR) and mitomycin C (MMC). We repeated this therapy six times. The size of the primary lesion and the lymph node metastases decreased significantly after the chemotherapy. The size of the liver metastases did not change, but they appeared to necrotize. The patient maintained a good quality of life during the therapy. He finally died of peritonitis carcinomatosa 18 months after the diagnosis. This case indicated that combination therapy of systemic and hepatic arterial infusion chemotherapy was effective in cases of unresectable gastric cancer associated with liver metastases.

Administration, Oral↗
PubMed2000

Dietary short-chain fructooligosaccharides increase calbindin-D9k levels only in the large intestine in rats independent of dietary calcium deficiency or serum 1,25 dihydroxy vitamin D levels.

Dietary short-chain fructooligosaccharides (Sc-FOS) increase mucosal calbindin-D9k (CaBP) levels in the large intestine whereas levels in the small intestine are decreased in rats. In the present study, we investigated the mechanism by which Sc-FOS induce this increase in CaBP in the large intestine by measuring intestinal CaBP levels in rats fed normal and calcium-deficient diets. Dietary groups included a calcium-containing (0.5%) diet with or without Sc-FOS (100 g/kg diet) and a calcium-deficient (abt. 0.01%) diet with or without Sc-FOS (100 g/kg diet). The rats were fed these diets for 10 days following which they were killed and the intestine removed for collection of the entire mucosa which was divided into four segments, i.e., proximal and distal segments of the small intestine, the cecum and the colorectum. Mucosal CaBP and plasma calcium (Ca), 1,25-dihydroxycholecalciferol (1,25(OH)2D3), 25-hydroxycholecalciferol (25(OH)D3), parathyroid hormone (PTH) and calcitonin levels were measured. Feeding of calcium deficient diet resulted in an increase in CaBP levels in the small intestine, but did not influence levels in the large intestine. Moreover, a significant positive correlation between plasma 1,25(OH)2D3 and CaBP levels in the case of both small intestinal segments (proximal, r = 0.77012, p < 0.00007; distal, r = 0.75056, p < 0.00014) was observed, but not in the case of the large intestinal segments. Sc-FOS increased CaBP levels in the large intestine. These results suggest that the large intestinal CaBP levels do not change in response to dietary calcium conditions and are not regulated by circulating 1,25(OH)2D3 indicating that the effect of Sc-FOS on CaBP levels in the large intestine is independent of the action of 1,25(OH)2D3.

Animals↗
PubMed2000

Diurnal variation in the P300 component of human cognitive event-related potential.

Diurnal variation in the P300 component of the human cognitive event-related potential (ERP) was examined. The P300 component is considered to be a measure of neuroelectric activity related to cognitive functions such as attention allocation and information processing. Nine diurnally active healthy male subjects whose sleep-wake rhythms were synchronized prior to the experiment were studied. The P300 components oral temperature, heart rate, left- and right-hand grip strength, reaction time, subjectively rated sleepiness, attention level, and fatigue were measured at 08:00, 11:00, 14:00, 17:00, and 20:00. Significant diurnal variations in P300 latency, P300 amplitude, oral temperature, heart rate, left- and right-hand grip strength, subjectively rated sleepiness, and attention level were observed. The P300 latency at 08:00 was significantly longer than at 11:00, 17:00, and 20:00, while the P300 amplitude at 08:00 was significantly greater than at 17:00 and 20:00. The P300 latency was correlated positively with subjectively rated sleepiness and negatively correlated with subjectively rated attention level. These results suggest the existence of diurnal variation in human cognitive functions.

Adult↗
PubMed2000

Circadian rhythm abnormalities of wrist activity of institutionalized dependent elderly persons with dementia.

BACKGROUND: The study objective was to clarify the descriptive characteristics of circadian rhythm abnormalities of wrist activity of the institutionalized elderly with dementia. METHODS: We studied 82 elderly persons with dementia who were institutionalized in a long-term medical care facility. The ambulatory continuous monitoring of their wrist activity was conducted for 7 days at 1-minute intervals. The time series data were analyzed using the double-plotted chronogram, spectral analysis was performed using the fast Fourier transformation and periodogram analysis was performed as well. RESULTS: The frequency of circadian rhythm abnormalities of wrist activity rhythm in elderly persons with dementia was 57.3% (47 out of 82). The abnormalities were classified into four categories: severely impaired circadian rhythm type with no boundary between day and night, free-running rhythm type, decreased circadian amplitude type, and accentuation of ultradian rhythm type. CONCLUSION: This four-category classification system provides a scientific approach for studying the mechanisms of circadian activity rhythm abnormalities of elderly persons with dementia.

Activity Cycles↗
PubMed2000

Time-of-day effects of ethanol consumption on EEG topography and cognitive event-related potential in adult males.

Time-of-day effects of ethanol consumption on EEG topography and cognitive event-related potential in adult males were studied. Ethanol (0.5 g/kg) or control drink was orally administered to nine healthy males at 10:00 and 18:00. The alpha 2 amplitude was significantly lower than that of the control at 0.5, 2.5 and 4.5 hours after ethanol consumption in the morning. These effects were observed in the left hemisphere and were only found after consumption in the morning. The subjectively rated attention was significantly lower than that of the control at 0.5 and 2.5 hours after ethanol consumption in the morning and at 0.5 hours after ethanol consumption in the evening. In contrast, the search speed of serial search task and P300 amplitude was significantly lower than that of the control at 2.5 hours after ethanol consumption in the evening. These results demonstrate that effects of ethanol are dependent on time-of-day of consumption. Ethanol consumption significantly lowered the alpha 2 amplitude when consumed in the morning, and lowered P300 amplitude when consumed in the evening.

Adult↗
PubMed2000

Reliability and validity of the questionnaire to determine the biosocial rhythms of daily living in the disabled elderly.

The questionnaire to determine the biosocial rhythms of daily living in the disabled elderly was newly developed. This questionnaire was aimed to evaluate a state of synchronization of biological rhythms in the disabled elderly. Eighteen items of the questionnaire relating to the synchronization of biological rhythms were finally selected by the test-retest method that was conducted for 68 disabled elderly living in a community with a duration of one year. The factor analysis showed that the questionnaire consisted of five factors: outdoor activities, ultradian rhythms, subjective evaluation of health status, social support, and sleep habits. The cumulative contribution rate of five factors was 53.2%. Reliability of the questionnaire was confirmed by a calculation of the Equal-length Spearman-Brown coefficients ranging from 0.60 to 0.80. Regarding the construct validity of the questionnaire, results of factor analysis showed five factors that were consistent with the synchronizers known in chronobiology. The total score of the questionnaire was significantly correlated to Barthel Index score and the competence score, suggesting that it partly reflects the activities of daily living of the disabled elderly. We conclude that a new questionnaire to determine the biosocial rhythm of daily living in the disabled elderly is useful to evaluate the biosocial synchronization of the disabled elderly because of its high reliability and validity.

Activities of Daily Living↗
PubMed2000

Examination of lacZ mutant induction in the liver and testis of Muta Mouse following injection of halogenated aliphatic hydrocarbons classified as human carcinogens.

Possible induction of lacZ mutation was examined in the liver and testis of Muta Mouse following the administration of carcinogenic halogenated compounds, namely 1,2-dichloroethane (DCE), 1,2-dibromoethane (DBE), carbon tetrachloride, or 1,2-dibromo-3-chloropropane (DBCP). Slight increases were observed on the mutant frequency in the testis DNA isolated from the mice 14 days after treatment with DBCP at 40 mg/kg or with DBE at 60 mg/kg but not in the liver. Further investigation was necessary to confirm the mutation induction by these chemicals in the testis including experiments with longer sampling intervals. No increase was detected in the frequency following DCE administration of single doses of up to 150 mg/kg or of consecutive injections of up to 280 mg/kg. Marginal but biologically insignificant responses were observed in the liver from the carbon tetrachloride exposed mice. The present results suggest that these carcinogenic chemicals are less efficient for induction of gene mutation in the liver of Muta Mouse.

Animals↗
PubMed1999

Induction of lacZ mutation by 7,12-dimethylbenz[a]anthracene in various tissues of transgenic mice.

The induction of gene mutations was examined in MutaMouse after an intraperitoneal injection of 7, 8-dimethylbenz[a]anthracene (DMBA) at 20 mg/kg in a collaborative study participated by four laboratories. Although the DMBA dose used was lower than the level that has been reported to induce micronucleated erythrocytes maximally in several mouse strains, a killing effect appeared after day 9 of the post-treatment interval. Mutations in lacZ transgene were detected by the positive selection assay following in vitro packaging of phage lambda from the genomic DNA of the transgenic animals that survived. The mutant induction was evaluated in the bone marrow, liver, skin, colon, kidney, thymus, and testis 7 to 28 days after the treatment. In the bone marrow, the mutant frequency reached a maximum, approximately a 30-fold increase, 14 days after the treatment and the increased frequency persisted at least up to day 28 of the post-treatment. Induction of mutants was detected in the liver, colon, thymus, and skin to lesser extents. Marginal responses were obtained in the kidney and testis. The slight increases in the mutant frequencies in the kidney and testis observed in some laboratories were within laboratory-to-laboratory or animal-to-animal variations. In contrast to the gene mutation induction in the bone marrow, the frequency of micronucleated reticulocytes increased transiently 3 days after the treatment and returned to a control level before day 8 of the post-treatment. It was suggested that DMBA induced gene mutation is fixed in stem cells depending on cell proliferation while DNA damages responsible for chromosome breakage are not transmitted to progeny cells.

9,10-Dimethyl-1,2-benzanthracene↗
PubMed1999

Evaluation of complex activities in daily living of elderly Japanese with visual impairment.

This study was conducted to determine whether elderly subjects with visual impairment differ in the performance of complex activities in daily living from those without visual impairment. The study subjects were residents in two homes for the aged in Japan, and consisted of 37 elderly people with visual impairment, and 42 elderly people, serving as controls; ages ranged from 64 to 95 years. Complex activities of the subjects were ascertained by interview using a 46-item questionnaire. The visually impaired elderly had lower performance levels for telephone use (p = 0.007), shopping (p = 0.049), cleaning up one's room (p = 0.001), and utilization of medical facilities (p = 0.001) in instrumental ADL (IADL); for interest in TV or radio (p = 0.004) and religious faith (p = 0.042) in "enriching activities"; and for visiting behaviors (p < 0.05) in "social role". The performances of complex activities by the elderly with visual impairment were diminished in specific categories, but not overall, and this may be attributable to poor mobility and/or more passive attitudes in their daily activities.

Activities of Daily Living↗
PubMed1999

[Evaluation of 24-hour home help services in a community by the focus group interview method].

The 24-hour home help services that provide day and night care services at home becomes a public health interest in Japan. The purpose of this study was to evaluate the system of 24-hour home help services in a community that has successfully developed it. Participants of this focus group interview were home helpers who were actually engaged in 24-hour home help services in A town of Akita Prefecture. The focus group session was tape-recorded and the tapes were transcribed. The transcripts were evaluated and summarized in order to identify major categories and number of descriptive statements in each category. The results were as follows. First, the home helpers considered that their system of 24-hour home help services could be technically transferred to other communities in Japan. Secondary, the political leadership and the democratic system of community participation were the essential elements for promoting the 24-hour home help services. Thirdly, the regular meetings for discussion about cases and opinion exchanges were required more extensively in the future.

Community Networks↗
PubMed1998

Body support effect on standing balance in the visually impaired elderly.

OBJECTIVE: To evaluate the effectiveness of body support in compensating for decreased standing balance stability in elderly persons with visual impairment. DESIGN: Standing balance was measured in a cross-section of elderly persons from two nursing homes--one for aged individuals with visual impairment, the other for aged individuals without visual impairment. PARTICIPANTS: The subjects were 44 visually impaired persons with a mean age of 79.0 yrs and 39 people without visual impairment, mean age 76.3 yrs. OUTCOME MEASURES: The area of gravity-center sway was measured with subjects standing on a gravicorder for 30sec in three positions: (1) without support, (2) with cane, (3) with light support by touching a wall. RESULTS: Both men and women in the visually impaired group swayed more than their sighted counterparts when standing without support, the only statistically significant difference between the two groups. For all subjects, the greatest degree of sway occurred when subjects stood unsupported, and the least sway occurred when subjects touched a wall for support. CONCLUSION: In visually impaired elderly persons, touching a wall for body support while standing is more effective than using a cane.

Aged↗
PubMed1998

Associations between anthropometric indices of adiposity and atherogenic risk factors in Japanese working women aged 21-40 years.

This study was conducted to explore whether anthropometric indices of obesity are associated with atherogenic risk factors in young adult working women in Japan. The subjects were 492 women in an occupational setting. Predictor variables were body mass index (BMI), the sum of triceps and subscapular skinfold thickness (SFT), and the waist to hip ratio (WHR). Outcome variables were serum total cholesterol, triglyceride and blood pressures. The average age of the subjects was 26.3 (SD 3.9) years. The upper quartiles of BMI and SFT were significantly associated with all atherogenic risk factors, while the upper quartiles of WHR were not. Multiple comparisons revealed the 4th quartiles of BMI (> 22.25) and SFT (> 39 mm) to have significantly higher values for all atherogenic risk factors. We found that BMI and skinfold thickness were more relevant to the prediction of atherogenic risk factors than WHR in young adult Japanese women.

Adipose Tissue↗