Demonstration of the stabilization technique for nonplanar optical resonant cavities utilizing polarization.

Based on our previously developed scheme to stabilize nonplanar optical resonant cavities utilizing polarization caused by a geometric phase in electromagnetic waves traveling along a twisted path, we report an application of the technique for a cavity installed in the Accelerator Test Facility, a 1.3-GeV electron beam accelerator at KEK, in which photons are generated by laser-Compton scattering. We successfully achieved a power enhancement of 1200 with 1.4% fluctuation, which means that the optical path length of the cavity has been controlled with a precision of 14 pm under an accelerator environment. In addition, polarization switching utilizing a geometric phase of the nonplanar cavity was demonstrated.

Risk modification by CYP1A1 and GSTM1 polymorphisms in the association of cigarette smoking and systemic lupus erythematosus in a Japanese population.

OBJECTIVES: Exposure to reactive oxygen species (ROS) through cigarette smoking is thought to contribute to the development of systemic lupus erythematosus (SLE). Metabolic enzymes are involved in ROS production. The aim of this study was to evaluate the modifying effect of metabolic polymorphisms on the association of cigarette smoking with SLE risk in a Japanese population. METHODS: We investigated the relationship of the cytochrome P450 (CYP) 1A1 rs4646903 and glutathione S-transferase (GST) M1 deletion polymorphisms to SLE risk with attention to interaction with cigarette smoking among 151 SLE cases and 421 controls in female Japanese subjects. Unconditional logistic regression was used to compute the odds ratios (ORs) and their 95% confidence intervals (CIs), with adjustments for several covariates. RESULTS: Smokers with the CC genotype of CYP1A1 rs4646903 were significantly associated with increased risk of SLE (OR 9.72, 95% CI 2.73-34.6). Similarly, smokers with the combined CYP1A1 rs4646903/GSTM1 'at-risk' genotype were significantly associated with increased risk of SLE (OR 17.5, 95% CI 3.20-95.9). More than 60% of the excess risk for SLE in smokers with the CC genotype and smokers with the combined 'at-risk' genotype was due to an additive interaction. A lack of association of the GSTM1 genotypes with smoking was observed. CONCLUSIONS: Our results suggest that a combination of smoking and either the CYP1A1 rs4646903 genotype or the combined metabolic genotype plays an important role in SLE susceptibility in our Japanese population. Additional studies are warranted to confirm the metabolic polymorphism-smoking interaction suggested in the present study.

Cigarette smoking, N-acetyltransferase 2 polymorphisms and systemic lupus erythematosus in a Japanese population.

Cigarette smoking may be associated with an increased risk of systemic lupus erythematosus (SLE), but the underlying mechanism of this association remains unclear. N-acetyltransferase 2 (NAT2) is highly variable and detoxifies aromatic amines, an important class of carcinogens in tobacco smoke. Individuals who possess homozygous polymorphic alleles have a slower rate of metabolic detoxification of aromatic amines. We investigated the relationship of the NAT2 polymorphism to the risk of SLE with special reference to the interaction with cigarette smoking among 152 SLE cases and 427 controls in a female Japanese population. NAT2 4, NAT2 5B, NAT2 6A and NAT2 7B alleles were detected with polymerase chain reaction-restriction fragment length polymorphism. Individuals carrying the 4/4 genotype are rapid acetylators, whereas those with homozygous non- 4 genotypes have a slow acetylator phenotype. Cigarette smoking was associated with an increased risk of SLE (odds ratio [OR] = 2.26; 95% confidence interval [CI] = 1.46-3.50). The slow acetylator genotype of NAT2 was significantly associated with an increased risk of SLE (OR = 2.34, 95% CI = 1.21-4.52) compared with the rapid acetylator genotype. A gene-environment interaction was suggested, with a combination of the NAT2 slow acetylator genotype and smoking conferring significantly higher risk (OR = 6.44, 95% CI = 3.07-13.52; attributable proportion due to interaction = 0.50, 95% CI = 0.12-0.88), compared with the NAT2 rapid acetylator genotype and no history of smoking. This study suggests that, in this Japanese population, the NAT2 slow acetylator status may be a determinant in susceptibility to SLE.

Fruit and vegetable intake and risk of amyotrophic lateral sclerosis in Japan.

BACKGROUND: There has been little interest in the role of nutrition in the prevention of amyotrophic lateral sclerosis (ALS). We investigated the relationship between dietary intake of vegetables, fruit, and antioxidants and the risk of ALS in Japan. METHODS: Between 2000 and 2004, we recruited 153 ALS patients aged 18-81 years with disease duration of 3 years within the study period in accordance with El Escorial World Federation of Neurology criteria. Three hundred and six gender- and age-matched controls were randomly selected from the general population. Information on dietary factors was collected using a validated self-administered diet history questionnaire. RESULTS: A higher consumption of all fruits and vegetables and fruit alone in the highest quartiles was associated with a statistically significantly reduced risk of ALS. Although not statistically significant, a beneficial association between intake of all vegetables, green and yellow vegetables and other vegetables and ALS was found. No statistically significant dose-response relationship was observed between intake of beta-carotene, vitamin C and vitamin E and the risk of ALS. CONCLUSION: Our findings suggest that higher intake of food rich in antioxidants such as fruit and vegetables confer protection against the development of ALS.

Depression among caregivers of the frail elderly in Japan before and after the introduction of the Public Long-Term Care Insurance System.

Cross sectional studies were conducted in five towns in Japan before and after the introduction of the Long-term Care Insurance System (LTCIS), in order to evaluate the factors relating to depression among family caregivers for the frail elderly. Depressive caregivers were more likely to consult with their doctors, to be in poor health, to care for demented elderly with behavioral disturbances than the non-depressive caregivers both before and after the LTCIS. Before LTCIS, depressive caregivers were more likely to attend to the elderly for more than 16 hours per day than their counterparts. After the LTCIS, depressive caregivers were more likely to be a spouse, to care for a frail elderly male, and less likely to be able to go out without accompanying the elderly than their counterparts. Even after the introduction of LTCIS, half of the caregivers were depressive. It is suggested that a government agency should be created to support not only the frail elderly but also their caregivers.

Efficient propagation of polarization from laser photons to positrons through compton scattering and electron-positron pair creation.

We have demonstrated for the first time the production of highly polarized short-pulse positrons with a finite energy spread in accordance with a new scheme that consists of two-quantum processes, such as inverse Compton scattering and electron-positron pair creation. Using a circularly polarized laser beam of 532 nm scattered off a high-quality, 1.28 GeV electron beam, we have obtained polarized positrons with an intensity of 2 x 10(4) e+ /bunch. The magnitude of positron polarization has been determined to be 73 +/- 15(stat) +/- 19(syst)% by means of a newly designed positron polarimeter.

Dietary fat and meat intake and idiopathic pulmonary fibrosis: a case-control study in Japan.

SETTING: There is sparse epidemiologic information regarding the role of dietary factors in the development of idiopathic pulmonary fibrosis (IPF). OBJECTIVE: To examine the relationship between specific types of fatty acids and selected foods high in fat and IPF in Japan. DESIGN: Included were 104 cases aged > or = 40 years who had been diagnosed in the last 2 years in accordance with the most recent criteria. Controls aged > or = 40 years consisted of 56 hospitalised patients diagnosed as having acute bacterial pneumonia and four out-patients with common cold. RESULTS: Intake of saturated fatty acids, mono-unsaturated fatty acids, n-6 polyunsaturated fatty acids and meat was independently associated with an increased risk of IPF. Specifically, the multivariate OR for comparison of the highest with the lowest quartile of intake of saturated fatty acids was 6.26 (95%CI 1.79-24.96, P for trend = 0.01) and for meat it was 7.19 (95%CI 2.15-27.07, P for trend = 0.02). Intake of cholesterol, n-3 polyunsaturated fatty acids, fish, eggs and dairy products was not related to the risk. CONCLUSION: These findings suggest that consumption of saturated fatty acids and meat may increase the risk of IPF.

Polarimetry of short-pulse gamma rays produced through inverse Compton scattering of circularly polarized laser beams.

We have developed a polarimetry of ultrashort pulse gamma rays based on the fact that gamma rays penetrating in the forward direction through a magnetized iron carry information on the helicity of the original gamma rays. Polarized, short-pulse gamma rays of (1.1+/-0.2)x10(6)/bunch with a time duration of 31 ps and a maximum energy of 55.9 MeV were produced via Compton scattering of a circularly polarized laser beam of 532 nm off an electron beam of 1.28 GeV. The first demonstration of asymmetry measurements of short-pulse gamma rays was conducted using longitudinally magnetized iron of 15 cm length. It is found that the gamma-ray intensity is in good agreement with the simulated value of 1.0x10(6). Varying the degree of laser polarization, the asymmetry for 100% laser polarization was derived to be (1.29+/-0.12)%, which is also consistent with the expected value of 1.3%.

Patterns of outcome of caregiving for the impaired elderly: a longitudinal study in rural Japan.

This longitudinal study investigates the experiences among Japanese caregivers who provide informal care at home to the impaired elderly over one year. Little is known about longitudinal changes in caregivers' burden in Japan. Between 1998-1999, 47 pairs of impaired elderly and their caregivers were followed in Matsuyama Town in a rural area of northern Japan. Caregivers were interviewed initially and then again 12 months later. Findings indicated that the mean score of the Zarit Burden Interview at Time 2 was significantly lower than that of Time 1, suggesting that caregivers adapted to their role over time. Outcomes were further categorized as successful and unsuccessful, depending on the pattern of change over one year. Two factors were related to the outcome in univariate analyses: caring for someone with dementia, and caregiver being a spouse. Logistic regression demonstrated that caring for someone with dementia was five times more likely to be associated with an unsuccessful outcome. The caregiver spouse was five times more likely to be associated with a successful outcome, while daughters-in-law were more likely to have an unsuccessful outcome. The present study suggests that (1) changes in well-being among caregivers in Japan are similar to those observed in most studies in the West, and (2) there was evidence of both the adaptation and wear-and-tear models among caregivers over time.

Awareness of the new long-term care insurance system and social services for elderly care in non-medical junior college students.

The present study was conducted in order to investigate the awareness of the new long-term care insurance and social services for the elderly care among young people. Non-medical junior college students answered a self-administered questionnaire about the new long-term insurance and other related matters. The present study revealed that only a small percentage of students knew about "the new public long-term care insurance system" (13% for males and 11% for females), "care-manager" (11% and 8%), or "care-plan" (9% and 5%) in 1999, just one year before this insurance system took effect. In contrast, more than one third of the students knew about "home-help service" (41% and 47%), "long-term care institution for the elderly" (33% and 35%), and "elderly care nursing home" (33% and 36%). However, these rates were much lower than the rates among nursing students in 1998. An educational program for non-medical students should be recommended to help them to understand our rapidly aging society and to take an interest in public policies and social services for the elderly in Japan.

Depression among caregivers of elderly patients on chronic hemodialysis.

The present study was conducted to investigate depression in caregivers of elderly hemodialysis patients. Caregivers answered a self-administered questionnaire about various factors that may affect their depression, and also completed a Center for Epidemiologic Studies Depression Scale evaluation (CESD). The frail elderly who received regular nurse visits were used as controls. Compared with the caregivers of controls, those of hemodialysis patients spent less time on caregiving and had more time to go out unaccompanied by their patients. Males were numerous among hemodialysis patients than in the controls. Compared with the controls, hemodialysis patients were less likely to be older old (80 years old and more), diagnosed as demented or severely limited in activities of daily living (ADL). On the other hand, we did not find any significant difference between the two groups with regard to either the prevalence of depression, the rate of those who experienced any life event such as to cause depression within 6 months (e.g., death of family member), duration of caregiving or time looking after patients. Caregivers of hemodialyis patients may feel a heavy burden because they are obliged to play an important role in supporting patients on dialysis. They seem to need more social support regardless of whether or not their patients suffer from dementia.

Burden among caregivers of frail elderly in Japan.

The present study was conducted in order to investigate the factors related to the feelings of psychological stress, called heavy burden, in caregivers who took care of frail elderly in the eastern part of Fukuoka Prefecture, Kyushu, Japan. Fifty-eight caregivers answered a self-administered questionnaire, involving the Japanese version of the Zarit Caregiver Burden Interview (ZBI) and thus described their own caregiving situation. Compared to caregivers with a light burden, heavily burdened caregivers were less likely to have time to go out without patients, but were more likely to consult physicians. Heavily burdened caregivers spent a longer time on looking after the elderly as well as on physical caregiving, and also used more social services than lightly burdened caregivers. However, the physical disabilities of the patients did not differ between the two groups. Even after controlling for confounding factors, the time spent on looking after frail elderly was found to be a significant factor related to the caregivers' heavy burden (10-24 hrs vs. 0-9 hrs; odds ratio: 5.35, 95% confidence interval: 1.17-25.58). These findings suggest that looking after frail elderly for a long time seems to be an important factor related to caregivers' developing psychological feelings of heavy burden.

The new public long-term care insurance system and feeling of burden among caregivers of the frail elderly in rural Japan.

The present study was conducted to investigate the factors related to the feelings of burden (i.e., stress) among caregivers of the frail elderly in rural Japan after the introduction of the new public long-term care insurance system in 2000. Forty-one out of 42 caregivers answered a self-administered questionnaire (i.e., the Japanese version of the Zarit Caregiver Burden Interview (ZBI)) regarding their caregiving situation. Compared with lightly burdened caregivers (n = 20; ZBI > or = 41), those heavily burdened (n = 21; ZBI < or = 40) attended the frail elderly with greater numbers of behavioral disturbances (2.2 +/- 2.6 vs. 0.6 +/- 1.0, p = 0.02) and those with dementia (60.9% vs. 39.1%, p = 0.08). Heavily burdened caregivers spent a longer time with the elderly (17.9 +/- 6.1 hours vs. 11.8 +/- 8.4 hours, p = 0.01) as well as in providing for their physically care (14.0 +/- 7.9 hours vs. 8.6 +/- 8.2 hours, p = 0.04), thus having less time to go out unaccompanied by their patients (1.1 +/- 1.6 hours vs. 2.4 +/- 2.3 hours, p = 0.04). Such caregivers tended to be depressed (70.0% vs. 42.9%, p = 0.08), although they used more social services (5.2 +/- 2.0 vs. 3.7 +/- 2.1, p = 0.03) than the lightly burdened caregivers. In addition, more than half of caregivers (56.1%) in the present study were depressed. This rate was higher than the rates in our studies before the introduction of the new public long-term care insurance system (a rural town: 53.3%, an urban town 46.6%). Furthermore, the number of social services used by caregivers did not seem to increase after the introduction of this insurance system (before: 4.1 +/- 2.0, after: 4.4 +/- 2.1). These findings suggest that the quantity and quality of social services for the frail elderly and their caregivers may not suffice even after the introduction of the new public long-term care insurance system.

Role of hypertension, dyslipidemia and diabetes mellitus in the development of coronary atherosclerosis in Japan.

The present study evaluated the effect of hypertension (HT), dyslipidemia and diabetes mellitus (DM) on the development of coronary atherosclerosis in the Japanese population, using a cross-sectional study of 433 patients (254 men and 179 women) aged 30 years or older who underwent coronary angiography for suspected or known coronary heart disease angina at 5 cardiology departments in the Fukuoka area between September 1996 and August 1997. Patients with a disease duration of 6 months or more were excluded. The main outcome measure was angiographically defined coronary artery stenosis and was found to a significant degree in 146 patients (33.7%). HT, DM, low levels of high-density lipoprotein cholesterol (HDL-C) and hypertriglyceridemia remained as significant coronary artery disease (CAD) risk factors even after controlling for age, sex, hospital, smoking, alcohol use, body mass index and leisure time physical activity. However, hypercholesterolemia was not a significant risk factor after adjusting for these variables. After controlling for these variables, DM, low HDL-C and hypertriglyceridemia were significant CAD risk factors for men, but only DM was a significant CAD risk factor in women. These results indicate that in Japan DM, low HDL-C and hypertriglyceridemia may be more important CAD risk factors than hypercholesterolemia.

[Effects of acupuncture therapy on low back pain and/or knee pain in elderly patients].

In April 1999, 75 elderly patients (mean age: 79 years old) with low back pain and/or knee pain visited an acupuncture and physical therapy unit in a geriatric hospital. A cross-sectional study was carried out in order to evaluate the effects of acupuncture therapy on low back pain and/or knee pain in elderly patients. Among them, 60 patients answered that their pain diminished following their therapy. The proportion of patients who were treated with acupuncture therapy were higher in these 60 patients than the other 15 patients (55.5% vs. 26.7%, p = 0.05). The result suggests that acupuncture therapy may be able to relieve low back pain and/or knee pain in elderly patients. However, 46% of the patients with acupuncture therapy were also treated with other types of physical therapy. Further studies should be recommended to confirm the effects of acupuncture therapy on low back pain and/or knee pain.

Caregiver depression predicts early discontinuation of care for disabled elderly at home.

This longitudinal study investigates the caregiving experiences among Japanese caregivers who provided informal care at home for disabled elderly between 1998 and 1999. Forty-seven caregivers of the impaired elderly continued caregiving at home in Matsuyama Town, a rural area of northern Japan, while 18 caregivers discontinued it. The mean score of the Center for Epidemiologic Studies Depression Scale in 1998 among those who gave up caregiving was significantly higher than that of those who continued caregiving, indicating that depression predicts early discontinuation of care in the home. This is one of the few studies in Japan to suggest that initial caregiver depression is a factor in the decision to terminate care for the disabled elderly at home.

Obesity, body fat distribution and coronary atherosclerosis among Japanese men and women.

OBJECTIVE: To investigate the relation of the obesity and body-fat distribution with angiographically defined coronary atherosclerosis. DESIGN: Cross-sectional study in a clinical setting. SUBJECTS: Three hundred and twenty men (median age, 59 y) and 212 women (median age, 67 y) who underwent coronary angiography for suspected or known coronary heart disease at 5 cardiology departments between September 1996 and August 1997. Patients with disease duration >1 y were excluded. MEASUREMENTS: The body mass index (BMI) and the waist to hip circumference ratio (WHR) were used as main exposure variables, and either the presence of significant coronary stenosis or the Gensini's score (> or =10 vs<10) as an outcome variable, in a sex-specific multiple logistic regression analysis controlling for age, hospital, and other coronary risk factors. RESULTS: Among male patients, BMI was progressively higher with an increasing number of vessels involved (P trend=0.05); the adjusted odds ratios for the presence of significant stenosis across quartiles of BMI were 1.0 (reference), 1.1, 1.9 and 2.5 (P trend=0.02), and the positive association was more pronounced for younger patients. Among females, however, such associations were not evident. Employing the Gensini's score as an outcome gave similar results. WHR was not significantly associated with either outcome regardless of sex. CONCLUSION: These results suggested that BMI was predictive of coronary stenosis among male patients, but not among female patients. Unlike most previous studies, this study failed to detect a positive association with WHR.