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Biomedical subjects

Hideki Hashimoto

Publications and source records attributed to Hideki Hashimoto.

At least 37 records · Page 2Linked to original sources

Local electrostatic field induced by the carotenoid bound to the reaction center of the purple photosynthetic bacterium Rhodobacter sphaeroides.

Electroabsorption (EA) spectra were recorded in the region of the reaction center (RC) Qy absorption bands of bacteriochlorophyll (Bchl) and bacteriopheophytin, to investigate the effect of carotenoid (Car) on the electrostatic environment of the RCs of the purple bacterium Rhodobacter (Rb.) sphaeroides. Two different RCs were prepared from Rb. sphaeroides strain R26.1 (R26.1-RC); R26.1 RC lacking Car and a reconstituted RC (R26.1-RC+ Car) prepared by incorporating a synthetic Car (3,4-dihydrospheroidene). Although there were no detectable differences between these two RCs in their near infrared (NIR) absorption spectra at 79 and 293 K, or in their EA spectra at 79 K, significant differences were detected in their EA spectra at 293 K. Three nonlinear optical parameters of each RC were determined in order to evaluate quantitatively these differences; transition dipole-moment polarizability and hyperpolarizability (D factor), the change in polarizability upon photoexcitation (Deltaalpha), and the change in dipole-moment upon photoexcitation (Deltamu). The value of D or Deltaalpha determined for each absorption band of the two RC samples showed similar values at 77 or 293 K. However, the Deltamu values of the special pair Bchls (P) and the monomer Bchls absorption bands showed significant differences between the two RCs at 293 K. X-ray crystallography of the two RCs has revealed that a single molecule of the solubilizing detergent LDAO occupies part of the carotenoid binding site in the absence of a carotenoid. The difference in the value of Deltamu therefore represents the differential effect of the detergent LDAO and the carotenoid on P. The change of electrostatic field around P induced by the presence of Car was determined to be 1.7 x 10(5) [V/cm], corresponding to a approximately 10% change in the electrostatic field around P.

Carotenoids↗

Patient contribution to the medical dialogue and perceived patient-centeredness. An observational study in Japanese geriatric consultations.

BACKGROUND: Relatively few studies have directly addressed the interaction dynamics and consequences of a companion's presence in the medical visit, and their findings have been contradictory. OBJECTIVES: To examine how patient's contribution to the medical dialogue, with or without the presence of a visit companion, is related to the perception of the medical visit as patient-centered. DESIGN: Observational study using pre- and postvisit questionnaires and audiotape recording of medical visits. PARTICIPANTS: One hundred and fifty-five patients aged 65 or over; 63 in medical visits that included the presence of a companion and 82 in visits that did not include a companion. MAIN OUTCOME MEASURE: Patient ratings of visit patient-centeredness. RESULTS: Long visits (greater than 10 minutes long) and visits in which patients were verbally active were rated as more patient-centered by patients than other visits. Since patients were generally less verbally active in visits that included a companion, accompanied visits, especially if they were less than 10 minutes long, received lower patient-centered ratings than others. The presence of a companion was not related to length of the visit, suggesting that the verbal activity of the companion was off-set by decreased verbal activity of the patient. CONCLUSIONS: Our results have suggested that patients are more likely to perceive their physician and visit as patient-centered when they have an opportunity to engage directly in the medical dialogue. A minimal amount of "talk-time" for patients themselves should be safeguarded even in a short visit, when a companion is present.

Aged↗

Hypertension is the most common component of metabolic syndrome and the greatest contributor to carotid arteriosclerosis in apparently healthy Japanese individuals.

The cluster of metabolic and hemodynamic risk factors known as metabolic syndrome is known to be a risk factor for ischemic cardiovascular diseases and stroke. By analyzing the cross-sectional data from 8,144 individuals (age 19-88 years) who underwent general health screening, we have investigated the prevalence of metabolic syndrome, as diagnosed by modified-National Cholesterol Education Program (NCEP) criteria corresponding to the following five categories: triglycerides > or = 150 mg/dl; high density lipoprotein (HDL)-cholesterol < 40 mg/dl in men or < 50 mg/dl in women; fasting plasma glucose > or = 110 mg/dl; systolic/diastolic blood pressure > or = 130/85 mmHg; and body mass index > 25 kg/m2. We found that the prevalence of metabolic syndrome was 19% in men and 7% in women. After adjustment for age, metabolic syndrome was found to be significantly more prevalent in men than in women, with an odds ratio of 3.08 (95% confidence interval [CI] 2.62-3.61, p < 0.0001). Among the five metabolic/hemodynamic risk factor components, hypertension was observed most frequently in individuals with metabolic syndrome, at 85% in men and 87% in women. In addition, multivariate logistic regression analysis adjusted for age, sex, serum total cholesterol levels, and smoking status showed that hypertension possessed the greatest odds ratio (1.43, 95% CI 1.27-1.60) for carotid plaque among the metabolic/hemodynamic risk factors. These data emphasize the importance of controlling blood pressure for reducing the risk of both metabolic syndrome and carotid arteriosclerosis in apparently healthy individuals.

Aged↗

Gender and family composition related to discharge destination and length of hospital stay after acute stroke.

Informal care by family members still plays an important role in home care after acute stroke. This study determined the clinical and demographic factors, such as family structure, that predict discharge to home and length of hospital stay (LOS) after acute stroke hospitalization. We reviewed the sex, age, family structure before stroke, type of stroke, size of the lesion, activities of daily living (ADL) function at discharge, discharge destination, and LOS of stroke patients (114 cerebral infarctions and 44 intracerebral hemorrhages) admitted to a neurosurgical hospital. Patients with cerebral infarction were older than those with intracerebral hemorrhage (median 75 vs 66 years). Ninety-eight were discharged to home (62%). In the logistic regression analysis, low ADL function, medium or large infarction, and intracerebral hemorrhage (vs lacunar infarction) were significantly associated with discharge to a destination other than home. Of the patients discharged home, low ADL function was strongly associated with LOS in the multiple regression analysis. In addition, living with a spouse only had the opposite effect on LOS in men and women (p=0.050 and 0.071, respectively). LOS tended to be shorter for men with a wife, but longer for women with a husband. The structure and gender roles in a stroke patient's household may need further attention for the efficient use of hospital resources.

Acute Disease↗

[Evaluation and improvement of QOL among IBD patients].

This article provided a short review on the assessment of quality of life (QOL) among patients with ulcerative colitis. Quantitative approach with psychometric measures has empirically showed that psycho-social aspects of patient's QOL are often affected by her clinical, psychological, and social conditions. Although the control of disease activities plays a pivotal role for improving patient's QOL, more holistic approach such as psychoeducational intervention should also be considered to enhance patient's self-efficacy and sense of control. Besides, qualitative research suggests that helping patient's narrative reconstruction through enhanced communication with the physician may be the most powerful tool that the physician can provide for improving patient's QOL.

Colitis, Ulcerative↗

The very early events following photoexcitation of carotenoids.

The recent availability of laser pulses with 10-20 fs duration, tunable throughout the visible and near infrared wavelengths, has facilitated the investigation, with unprecedented temporal resolution, into the very early events of energy relaxation in carotenoids [Science 298 (2002) 2395; Synth. Metals 139 (2003) 893]. This has enabled us to clearly demonstrate the existence of an additional intermediate state, Sx, lying between the S2 (1(1)Bu+) and S1 (2(1)Ag-) states. In addition, by applying time-resolved stimulated Raman spectroscopy with femtosecond time resolution, it has also been shown that vibrational relaxation in electronic excited states plays an important role in these interconversions. In this mini-review, we describe briefly the current understanding of Sx and the other intermediate excited states that can be formed by relaxation from S2, mainly focusing attention on the above two topics. Emphasis is also placed on some of the major remaining unsolved issues in carotenoid photochemistry.

Carotenoids↗

Association between white blood cell count and carotid arteriosclerosis in Japanese smokers.

Recent studies have shown the relationship between general inflammatory markers and ischemic heart and cerebrovascular diseases. Here we have investigated the potential association between the circulating white blood cell count and carotid arteriosclerosis in apparently healthy individuals. Between 1994 and 1998, 3455 subjects who had undergone general health screening tests including carotid ultrasonography were enrolled in this study. The intertertile cutoff points for the white blood cell count were 5.1 x 10(3) and 6.4 x 10(3) microL(-1) in the male subjects and 4.6 x 10(3) and microL(-1) in the female subjects. The prevalence of carotid plaque in the first (lowest), the second, and the third tertiles was 19, 28, and 28% in the male subjects, respectively (P < 0.0001), and 10, 15, and 14% in the female subjects, respectively (n.s.). The multivariate analysis showed that the male subjects in the second and third tertiles had increased risk for carotid plaque with odds ratios of 1.54 (95% CI 1.18-2.01) and 1.47 (95% CI 1.11-1.95), respectively, compared to those in the first tertile. When male subjects were subdivided according to their smoking status, the association between white blood cell count and carotid plaque was significant in those who smoked, but not in those who had never smoked. These data suggested the possible association between the circulating white blood cell count and formation of carotid plaque in male smokers, but not in male never smokers or in females, in an apparently healthy Japanese population.

Arteriosclerosis↗

Psychosomatic status affects the relationship between subjective hearing difficulties and the results of audiometry.

OBJECTIVE: Subjective hearing difficulties are often used as a surrogate to audiometry in health check-up, although its effectiveness has not been tested in healthy workers. We conducted a study to test the usefulness of self-reported hearing difficulties for screening hearing impairment among healthy workers by comparing the results with those of audiometry. STUDY DESIGN AND SETTING: This was a cross-sectional observational study. A sample of 12,495 healthy workers in Japan without excess noise exposure was recruited at regular health check-up. Audiometry was conducted after self-administered questionnaire asking symptoms including hearing difficulties. The results were compared to those of audiometry as the gold standard. RESULTS: Overall prevalence of hearing impairment was 4.6% among the population. Subjective hearing difficulties showed 0.21 of sensitivity, 0.95 of specificity, and 0.93 of accordance against audiometry. When limited to those with more than two psychosomatic symptoms, however, the corresponding numbers were 0.43, 0.85, and 0.83. CONCLUSION: The assessment of subjective hearing difficulty may not be able to replace audiometry, but may be useful to detect psychosocial problems of hearing in the workplace.

Adolescent↗

The influence of locus of control on preferences for information and decision making.

Previous studies reported inconsistent relationship between the preference for information and that for decisional autonomy in medical encounters. We hypothesized that the relationship may be dependent on people's attribution beliefs on health. To test the hypothesis, demographically representative sample of Japanese population over the age of 18 (N = 3395) were invited into self-administered questionnaire survey. Preferences for information and decisional autonomy were measured by a translated version of autonomy preference index. Health attribution was measured by a scale modified from multi-dimensional health locus of control scales. After adjusting for socio-economic status, multivariable linear regression analysis revealed that information preference was positively associated with decisional preference among individuals who believed their health is less dependent on influential others. However, the reversed relationship was observed in case of individuals with attribution to others. The results suggested that individuals may use medical information for different purposes according to the types of health-related attribution beliefs.

Adaptation, Psychological↗

Protein regulation of carotenoid binding; gatekeeper and locking amino acid residues in reaction centers of Rhodobacter sphaeroides.

X-ray diffraction was used to determine high-resolution structures of the reaction center (RC) complex from the carotenoidless mutant, Rb. sphaeroides R-26.1, without or reconstituted with carotenoids. The results are compared with the structure of the RC from a semiaerobically grown Rb. sphaeroides strain 2.4.1. The investigation reveals the structure of the carotenoid in the different protein preparations, the nature of its binding site, and a plausible mechanism by which the carotenoid is incorporated unidirectionally in its characteristic geometric configuration. The structural data suggest that the accessibility of the carotenoid to the binding site is controlled by a specific "gatekeeper" residue which allows the carotenoid to approach the binding site from only one direction. Carotenoid binding to the protein is secured by hydrogen bonding to a separate "locking" amino acid. The study reveals the specific molecular interactions that control how the carotenoid protects the photosynthetic apparatus against photo-induced oxidative destruction.

Amino Acids↗

Excessive alcohol intake increases the risk of arterial stiffening in men with normal blood pressure.

Excessive alcohol intake is a known atherosclerotic cardiovascular risk factor. However, the relation between excessive alcohol intake and atherosclerotic cardiovascular risk in subjects with normal blood pressure has not been fully elucidated. This cross-sectional study investigated the relationship between alcohol intake and arterial stiffness, as assessed using brachial-ankle pulse wave velocity, in men with normal blood pressure. Middle-aged male workers who were found to have a normal blood pressure during an annual health check-up performed in May-July 2000 (n=1,682) were enrolled in the study. The subjects' laboratory data were analyzed, and information on drinking and smoking habits was obtained by a self-administered questionnaire. The brachial-ankle pulse wave velocity was measured using volume plethysmography. The mean brachial-ankle pulse wave velocities of men with an alcohol intake of 40-59 g/day and > or =60 g/day were larger than those of non-drinkers and men with an alcohol intake of <20 g/day. A multivariate general linear model was used to identify the association between alcohol intake and brachial-ankle pulse wave velocity after controlling for other risk factors using a multivariate analysis. An alcohol intake of more than 60 g of ethanol/day was significantly associated with an elevated brachial-ankle pulse wave velocity, after controlling for conventional atherosclerotic cardiovascular risk factors. In conclusion, the present results suggest that excessive alcohol intake increases the atherosclerotic cardiovascular risk associated with arterial stiffening in men with normal blood pressure.

Adult↗

Association between insulin resistance and carotid arteriosclerosis in subjects with normal fasting glucose and normal glucose tolerance.

OBJECTIVE: We examined the possible association between insulin resistance and carotid arteriosclerosis in subjects who had both normal fasting glucose and normal glucose tolerance after intake of a glucose load. METHODS AND RESULTS: Our subjects were individuals who underwent general health screening at our institute, which included carotid ultrasound and oral glucose tolerance testing. Of the 1238 subjects enrolled in our study, 738 (60%) were classified as normal, defined as a normal fasting glucose level and normal glucose tolerance, and 334 (27%) and 166 (13%) were classified as borderline and diabetic, respectively, according to the criteria of the Japan Diabetes Society. The homeostasis model assessment of insulin resistance (HOMA-IR) was used as the index to measure insulin resistance. In normal-type subjects, univariate analysis showed that insulin resistance, but not insulin secretion, was associated with the presence of carotid plaque. Multivariate analysis showed that HOMA-IR was positively associated with carotid plaque in normal-type subjects, with an odds ratio of 1.19 (95% confidence interval, 1.00 to 1.41; P<0.05). CONCLUSIONS: These data suggest the possibility that the presence of higher insulin resistance could be a risk factor for carotid arteriosclerosis in subjects with normal fasting glucose and normal glucose tolerance.

Adult↗

Reliability, validity, and responsiveness of the Japanese version of the Inflammatory Bowel Disease Questionnaire.

BACKGROUND: Inflammatory bowel disease affects the quality of a patient's life in many ways, but no validated instrument for measuring disease-specific quality of life in these patients is available in Japan. We developed a Japanese version of the Inflammatory Bowel Disease Questionnaire (IBDQ), together with the author of the original English-language version. METHODS: Translation and cross-cultural adaptation followed an accepted process. The reliability, validity, and responsiveness of the IBDQ's four subscales were then assessed in a prospective cohort of Crohn's disease patients who underwent hospitalization. RESULTS: Internal consistency was acceptable for all four subscales. Concurrent validity (with the Short Form [SF]36 as a reference) was as expected. Scores on the IBDQ could be used to discriminate patient subgroups with different levels of disease activity. Responsiveness was comparable to that of the SF36. CONCLUSIONS: This Japanese version of the IBDQ is reliable, valid, and responsive for assessing disease-specific quality of life in patients with Crohn's disease.

Adult↗

Validation of a Japanese patient-derived outcome scale for assessing total knee arthroplasty: comparison with Western Ontario and McMaster Universities osteoarthritis index (WOMAC).

We have developed a Japanese self-administered questionnaire based on an English version of the Western Ontario and McMaster Universities osteoarthritis index (WOMAC) to measure subjective function and pain status of patients who undergo a total knee arthroplasty procedure. Using multiple international cohorts, the performance of the developed Japanese scale was compared to the results of the WOMAC in the United Kingdom, United States, Canada, and Australia. The developed scale showed a comparable level of internal consistency and construct/criterion validity. The responsiveness of the scale was superior to the concurrently measured MOS Short Form 36 Physical Function scale. These results suggest that the developed scale is reliable, valid, and responsive for assessing the effectiveness of total knee arthroplasty in the Japanese context despite the cultural life style differences from Western countries.

Arthroplasty, Replacement, Knee↗

Health-related quality of life of Japanese patients with chronic heart failure: assessment using the Medical Outcome Study Short Form 36.

Chronic heart failure is characterized by impaired cardiac function, but the relationship between clinical indices and subjective perception is not clear. This study was undertaken to investigate the relationship between cardiac function, exercise capacity and clinical classification, and the health-related quality of life (HRQOL) in 91 outpatients with an left ventricular ejection fraction (LVEF) less than 40%. Exercise capacity was evaluated by the Specific Activity Scale, and HRQOL by the Medical Outcome Study Short Form 36. Exercise capacity and the cardiothoracic ratio were correlated with the HRQOL related to physical functioning, although the correlation between exercise capacity and mental health was not significant. LVEF was not related to HRQOL. Factor analysis revealed (1) LVEF was independent of physical functioning; (2) physical function and exercise capacity comprise a factor reflecting physical HRQOL; and (3) socio-emotional functioning is the third factor independent of LVEF and physical function. Physical and socio-mental HRQOL measurement included information independent of the widely used clinical indices such as LVEF and New York Heart Association classification. The evaluation of HRQOL should be included in the assessment of patient status.

Aged↗

Association between hepatitis C virus core protein and carotid atherosclerosis.

A link between certain infectious microorganisms and an increased risk of atherosclerotic disease has been suggested. By analyzing the data of subjects who had undergone general health-screening tests, a possible association between carotid atherosclerosis and seropositivity of antibody against hepatitis C virus (HCV) has been previously reported. In the present study, a possible link between carotid atherosclerosis and HCV core protein positivity was assessed, because it is postulated to be a better marker of viremia and thus persistent infection. Of the 1992 enrolled subjects, 496 (25%) had carotid artery plaque, and 25 (1.3%) were positive for HCV core protein. Carotid artery plaque was positive in 480/1967 (24%) and 16/25 (64%) of the core protein-negative and core protein-positive subjects, respectively (p<0.0001 by chi(2) test). Serum concentrations of transaminases were higher in core protein-positive subjects, but albumin concentrations were not significantly different between the 2 groups. Multivariate logistic regression analysis showed that HCV core protein positivity is an independent predictor of carotid plaque with an odds ratio of 5.61 (95% confidence interval 2.06-15.26, p<0.001). These data further support the possible link between persistent HCV infection and carotid atherosclerosis in the subjects without severe liver dysfunction.

Adult↗