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Probabilistic fracture mechanics (PFM) is considered a promising methodology in assessing the integrity of structural components in nuclear power plants because it can rationally represent the influence parameters in their probabilistic distributions without over-conservativeness. In Japan, Japan Atomic Energy Agency has developed a PFM analysis code PASCAL4 (PFM Analysis of Structural Components in Aging LWRs Version 4) which enables the probabilistic integrity assessment of reactor pressure vessels (RPVs) considering neutron irradiation embrittlement and pressurized thermal shock events. Several efforts have been made to verify PASCAL4 to ensure that this code can provide reliable analysis results. In particular, a Japanese working group, which consists of different participants from the industry and from universities and institutes, has been established to conduct the verification studies. This paper summarizes verification activities of the working group in the past two years. Based on those verification activities, the reliability and applicability of PASCAL4 for structural integrity assessments of Japanese RPVs have been confirmed with great confidence.

Several components of nuclear power plants are made of cast austenitic stainless steel (CASS) because of its high corrosion resistance and strength. The inservice inspection based on ultrasonic testing (UT) has to be conducted for CASS components in accordance with fitness-for-service codes such as the Japan Society of Mechanical Engineers Rules on Fitness-for-Service for Nuclear Power Plants. However, a high-accuracy evaluation of flaws in CASS components through UT is difficult because the ultrasonic waves are scattered and attenuated by coarse grains, and their beam is distorted by the anisotropy resulting from the grain orientations. Numerical simulations are useful and reasonable ways for better understanding the ultrasonic wave propagation behavior in CASS. To effectively achieve this, the simulation model should include a three-dimensional (3D) grain structure. If a casting simulation can predict the solidification structure in a CASS, the wave propagation could be simulated also for a more realistic situation. In this study, we predicted the solidification structure of statically CASS by using a cellular automaton (CA) coupled with the finite element method and fed this structure into an explicit finite element model (FEM) for simulating the propagation of waves emitted by angle beam probes. Afterward, these simulated wave propagations were compared with those measured by a 3D laser Doppler vibrometer (LDV), showing almost good agreement between predicted and experimental results.

Nowadays, it has been recognized that probabilistic fracture mechanics (PFM) is a promising methodology in structural integrity assessments of aged pressure boundary components of nuclear power plants, because it can rationally represent the influencing parameters in their inherent probabilistic distributions without over conservativeness. A PFM analysis code PFM analysis of structural components in aging light water reactor (PASCAL) has been developed by the Japan Atomic Energy Agency to evaluate the through-wall cracking frequencies of domestic reactor pressure vessels (RPVs) considering neutron irradiation embrittlement and pressurized thermal shock (PTS) transients. In addition, efforts have been made to strengthen the applicability of PASCAL to structural integrity assessments of domestic RPVs against nonductile fracture. A series of activities has been performed to verify the applicability of PASCAL. As a part of the verification activities, a working group was established with seven organizations from industry, universities, and institutes voluntarily participating as members. Through one-year activities, the applicability of PASCAL for structural integrity assessments of domestic RPVs was confirmed with great confidence. This paper presents the details of the verification activities of the working group, including the verification plan, approaches, and results.

Diastereoselective direct hydroarylation of glycals with aromatic compounds was realized by use of an iridium/binap catalyst, giving the corresponding C-glycosyl compounds in high yields. The use of binap with the different absolute configuration enabled the stereoselective synthesis of α- or β-C-glycosyl arenes irrespective of the chirality of the glycals....

Due to the significant spread of a new type of coronavirus (SARS-CoV-2) infection (COVID-19) in China, the Chinese government blockaded several cities in Hubei Province. Japanese citizens lost a means of transportation to return back to Japan. The National Center for Global Health and Medicine (NCGM) helped the operation of charter flights for evacuation of Japanese residents from Hubei Province, and this article outlines our experiences. A total of five charter flights were dispatched, and the majority of returnees (793/829 [95.7%]) were handled at NCGM. A large number of personnel from various departments participated in this operation; 107 physicians, 115 nurses, 110 clerical staff, and 45 laboratory technicians in total. Several medical translators were also involved. In this operation, we conducted airborne precautions in addition to contact precautions. Eye shields were also used. The doctors collecting the pharyngeal swab used a coverall to minimize the risk of body surface contamination from secretions and droplets. Enhanced hand hygiene using alcohol hand sanitizer was performed. Forty-eight persons were ultimately hospitalized after the triage at NCGM operation, which was more than the number of persons triaged at the airport (n = 34). Of those hospitalized after NCGM triage, 8.3% (4/48 patients) ultimately tested positive for SARS-CoV-2, significantly higher than the positive rate among subjects not triaged (4/48 [8.3%] vs. 9/745 [1.2%]: p = 0.0057). NCGM participated in a large-scale operation to evacuate Japanese nationals from the COVID-19 epidemic area. We were able to establish a scheme through this experience that can be used in the future.

Probabilistic fracture mechanics (PFM) is a rational methodology in structural integrity evaluation for nuclear power plants, and several PFM analysis codes have been developed. In general, the statistical distributions of random variables such as initial crack sizes and material properties are expressed as probability density functions, and a set of random variables are sampled from those functions for each repeated failure analysis to obtain the cumulative failure probability. Since most random variables are considered to have physical upper and lower limits in their distribution, it is essential to set reasonable cut-offs in the functions to avoid improper samplings. If a sufficient quantity of measured data is available, their population is supposed to intrinsically include the information from such limits. In this study, we developed a PFM analysis code, that can sample the variables based on the direct sampling of measured data by sampling with replacement in order to rationally evaluate the failure probability. The difference in failure probability was discussed between the general sampling procedure, which uses probability density functions, and the direct sampling procedure. Consequently, the failure probability obtained by the direct sampling procedure was approximately an order of magnitude lower than that obtained by the general sampling procedure.

Introduction: Sentinel surveillance in Japan is used to estimate national influenza incidence under the assumption that Sentinel Medical Institutions (SMIs) are randomly selected. The current method might lead to overestimation when SMIs are recruited on a voluntary basis. Aims & Objectives: We aimed to improve influenza incidence estimation using auxiliary information without this assumption. Materials and Method: We used reports of influenza from SMIs in 2015, together with the number of all disease outpatients in September 2014 at all medical institutions from the Survey of Medical Institutions of Japan, as auxiliary information. The influenza incidence was estimated by the method using auxiliary information and the current method (without auxiliary information). Result and Conclusion: Influenza incidence rate per 1,000 population in 2015 estimated by using auxiliary information and by the current method was 63.7 (95% Confidence Interval (CI), 61.0-66.3) and 96.5 (95% CI, 93.0-100.0), respectively. The ratio of these estimates was 0.66. Our findings suggest that influenza incidence estimated by using the number of all disease outpatients as auxiliary information is more accurate than estimates by the current method.

The surveillance test specified in JEAC4201 requires the fracture toughness evaluation of base metal at 1/4-T thickness and T-L orientation, where the initial fracture toughness generally is the minimum in whole thickness at any orientation. In the present study, actual through-wall fracture toughness distribution from a commercial RPV base metal on both of T-L and L-S (actual through crack orientation) orientations were evaluated from Zion Unit 1, which was decommissioned after 25 years (15EFPY) commercial operation. A base metal block of 40mm(T) × 216mm(L) × 216mm(S) was retrieved from belt line region by effort of ORNL and provided to CRIEPI under the USA - Japan collaborative agreement on civil nuclear research framework called CNWG. Through-wall fracture toughness distribution was characterized by means of the Master Curve method utilized by 4mm thickness C(T) “Mini-C(T)” specimens. Near surface material possessed significantly high fracture toughness at amount of 40 degrees Celsius lower reference temperature (To) than those in center thickness locations, despite of higher neutron fluence gained during service operation. Pressurized thermal shock evaluation by probabilistic fracture mechanics code PASCAL4 demonstrated that through-wall fracture probability can be remarkably lowered by considering through-wall fracture toughness distribution.

Epidemiological evidence on the relationships between the vitamin D receptor (VDR) single nucleotide polymorphisms (SNPs) rs731236 (TaqI), rs7975232 (ApaI), rs1544410 (BsmI), and rs2228570 (FokI) and Parkinson's disease (PD) is inconsistent. We investigated these relationships in 229 sporadic PD patients within six years of onset in Japan. Controls were 357 patients without neurodegenerative disease. Adjustment was made for sex, age, region of residence, and smoking. A significant inverse association was found between SNP rs2228570 and the risk of sporadic PD under the additive but not the co-dominant or dominant model (P=0.048); however, this fell below significance after adjustment for multiple comparisons (adjusted P=0.46). No significant relationships were found between SNPs rs731236, rs7975232, or rs1544410 and the risk of sporadic PD in any genetic model. VDR haplotypes inferred in the current study were not associated with sporadic PD. Compared with subjects with the GA or AA genotype of SNP rs2228570 who had ever smoked, those with the GG genotype who had never smoked had a 3.78-fold increased risk of sporadic PD; however, no significant interaction was observed. VDR SNP rs2228570 may be associated with sporadic PD in Japan. Smoking did not significantly modify the relationship between SNP rs2228570 and sporadic PD.

Performance demonstration certification of non-destructive inspection for cast stainless steel (CASS) has been planned but the target flaw depth to be detected has not been determined yet in Japan. The target flaw size is closely connected to the allowable flaw size which is determined by flaw evaluation of the rules on fitness-for-service. However duplex micro-structure of CASS makes low permeability of ultrasonic wave and large flaw size of UT detectability, which might not be acceptable by flaw evaluation. The current JSME rules for fitness-for-service allow only deterministic procedure. For rational mitigation of the acceptable flaw size, application of probabilistic fracture mechanics (PFM) is one of the useful countermeasures. In the paper, benchmark problems for a CASS pipe were proposed with intention applying and verifying PFM codes to CASS pipe's issue. As the fracture modes, fatigue crack extension, plastic collapse and ductile crack initiation were assumed. The PFM analyses were performed in the condition of the combination of crack extension and plastic collapse or ductile fracture to verify the basic functions of the PFM codes. Six organizations participated in the benchmark analysis and failure probabilities from them were compared. As a result the failure probability of each problem by each code showed good agreement and the code for application of CASS issue has been verified. The sensitivity of the failure criterion on the failure probability was discussed.

Iridium-catalyzed C–H alkylation of 3-carbonyl-2-(alkylamino)pyridines via secondary sp3 C–H activation adjacent to the nitrogen atom, with terminal alkenes proceeded to give the corresponding α-secondary amines in high yields. The reaction was efficiently catalyzed by a cationic iridium complex coordinated with 1,5-cyclooctadiene.

Epidemiological evidence on the relationships between PARK16 single nucleotide polymorphisms (SNPs) and Parkinson's disease (PD) is inconsistent. We examined this issue in Japan. Included were 229 cases within six years of PD onset. Controls were 356 patients without neurodegenerative disease. Compared with subjects with the AA genotype of SNP rs823128, those with the AG genotype, but not the GG genotype, had a significantly reduced risk of sporadic PD. Compared with the AA genotype of SNP rs947211, both the AG genotype and the GG genotype were significantly related to an increased risk of sporadic PD. Using subjects with the AA genotype of SNP rs823156 as a reference group, there were significant inverse relationships under the additive and dominant models. No significant relationships were found between SNPs rs16856139 or rs11240572 and sporadic PD. The CAAAC, the TGAGA, and the CAGAC haplotypes were significantly related to sporadic PD. The additive interaction between SNP rs823128 and smoking affecting sporadic PD was significant, although the multiplicative interaction was not significant. The PARK16 SNPs rs823128, rs947211, and rs823156 and the CAAAC, TGAGA, and CAGAC haplotypes may be significantly associated with sporadic PD in Japan. New evidence of an additive interaction between SNP rs823156 and smoking is suggested.

Objectives: This study aimed to investigate the clinical characteristics of polymyositis/dermatomyositis (PM/DM) in Japan by analyzing data from the nationwide registration system.Methods: The data of the registration system in 2009 were analyzed to investigate patient numbers, sex, clinical symptoms, therapies, complications, and prognosis of PM/DM.Results: The total number of PM/DM cases was approximately 17,000, and the female/male sex ratio was 2.7:1. Almost all patients improved as a result of therapy, but many suffered from sequelae such as muscle weakness.Conclusions: The results characterize significant aspects of Japanese PM/DM patients. However, a further prospective survey is required to clarify the true epidemiology and natural history of PM/DM.

In nuclear power plants, a number of cracks attributed to stress corrosion cracking (SCC) have been detected in welds made with nickel alloy weld metals. One of characteristics of these cracks is that the crack depth is greater than one half of the crack length. When a crack is detected in a component of a nuclear power plant during an in-service inspection, a flaw evaluation is conducted according to the requirement of fitness-for-service codes such as the JSME Rules on Fitness-for-Service for Nuclear Power Plants and the ASME Boiler and Pressure Vessel Code. Here, the stress intensity factor plays an important role for predicting crack growth behavior due to fatigue and/or SCC. Although several solutions of the stress intensity factor are already given in the codes, no solutions are available for the cracks having an aspect ratio greater than unity. Surface cracks with an aspect ratio greater than unity are characterized as semicircular. To evaluate these cracks in a rational manner, we developed a database of influence coefficients by means of the influence function method in conjunction with the finite element method. By using these influence coefficients, a solution for the stress intensity factor was developed for a semi-elliptical surface crack with high-aspect-ratio up to 8.0 subjected to a fifth-order-polynomial stress distribution.

Background Autosomal recessive congenital ichthyosis (ARCI) and ichthyosis syndrome (IS) are rare genetic skin disorders. Objective To estimate the number of patients with ARCI and IS in Japan and clarify the clinicoepidemiologic features of these diseases. Methods We performed a nationwide survey of patients treated for ARCI or IS during January 2005-December 2009. We developed diagnostic criteria and conducted a primary survey in a stratified random sample of Japanese hospitals to quantify the number of outpatients and inpatients with ARCI or IS. We performed a secondary survey of clinicoepidemiologic features in positive cases. Results The estimated number of patients receiving treatment for ARCI and IS during 2005-2009 was 220 (95% confidence interval [CI] 180-260). The estimated disease distribution was as follows: 95 (95% CI 80-110) patients with nonbullous congenital ichthyosiform erythroderma, 30 (95% CI 20-40) with lamellar ichthyosis, 15 (95% CI 10-20) with harlequin ichthyosis, and 85 (95% CI 50-120) with IS. Limitations Patients with a mild case of the disease might not have visited a dermatology department, potentially causing underestimation of affected patients. Conclusion We report the estimated number of patients with ARCI and IS in Japan and sex differences in the age distribution.

In nuclear power plants, inner surface of reactor pressure vessel, which is made of low-alloy steel, is cladded by austenitic stainless steel to improve corrosion resistance of vessel. In an evaluation of fatigue crack propagation behavior at J-welding portions of bottom mounted instrumentation in reactor pressure vessel, crack propagation crossing dissimilar materials interface between base metal of low-alloy steel and stainless steel cladding is assumed. Fatigue crack growth rate of the cladding is predicted to be captured by that of the base metal because thickness of the cladding is very thin compared that of the base metal. In this study, fatigue crack propagation analyses of cladded plates under cyclic loading were performed using XFEM, which can model crack independently of finite elements, as a preliminary study for crack propagation analyses considering dissimilar materials interface.

Probabilistic fracture mechanics (PFM) has been recognized as a promising methodology in structural integrity assessments of aged pressure boundary components of nuclear power plants because it can rationally represent the influencing parameters in their inherent probabilistic distributions without over conservativeness. In Japan, a PFM analysis code PASCAL (PFM Analysis of Structural Components in Aging LWR) has been developed by the Japan Atomic Energy Agency (JAEA) to evaluate the through-wall cracking frequencies of Japanese reactor pressure vessels (RPVs) considering neutron irradiation embrittlement and pressurized thermal shock (PTS) transients. In addition, efforts have been made to strengthen the applicability of PASCAL to structural integrity assessments of domestic RPVs against non-ductile fracture. On the other hand, unlike deterministic analysis codes, the verification of PFM analysis codes is not easy. A series of activities has been performed to verify the applicability of PASCAL. In this study, as a part of the verification activities, a working group was established in Japan, with seven organizations from industry, universities and institutes voluntarily participating as members. Through one year activities, the applicability of PASCAL for structural integrity assessments of domestic RPVs was confirmed with great confidence. This paper presents the details of the verification activities of the working group including the verification plan, approaches and results.

Background: The sentinel surveillance system in Japan provides estimates of nationwide influenza incidence. Although prefectural influenza incidences can be estimated using data from the current surveillance system, such estimates may be imprecise. Methods: We calculated the numbers of sentinel medical institutions (SMIs) needed in the surveillance system to estimate influenza incidences in prefectures, under the assumption that the standard error rates in 75% of influenza epidemic cases are less than 10%. Epidemic cases observed in 47 prefectures during the 2007/2008, 2008/2009, and 2009/2010 seasons, respectively, were used. Results: The present total number of SMIs was 6669. With respect to current standards, the increases required in prefectures ranged from 0 to 59, and the total increase required in the number of SMIs was 1668. Conclusions: We used sentinel surveillance data for Japan to calculate the number of SMIs required to estimate influenza incidence in each prefecture.

Stress intensity factor solutions are often used as a dominant fracture mechanics parameter for fatigue crack growth analysis. In ASME Boiler and Pressure Vessel Code Section XI as well as JSME Rules on Fitness-for-Service for Nuclear Power Plants, fatigue crack growth is predicted on the basis of the stress intensity factor range. Stress intensity factor solutions are frequently provided by the correction factors, which are tabulated as the functions of structure and/or crack sizes. In this study, the effect of the variation of the correction factors on the crack growth analysis results was investigated for pipes with surface cracks. The evaluation accuracy required for the correction factors of the stress intensity factor solutions was then examined and recommended from the comparison with the necessary accuracy of the parameters used for the fatigue crack growth analysis.Copyright © 2013 by ASME

It has been suggested that P-glycoprotein (P-gp), the product of multidrug resistance 1 (MDR1) gene, regulates the brain entry of various xenobiotics. Impaired function of P-gp may be associated with an increased risk of Parkinson's disease (PD). The aim of this study was to investigate the impact of a MDR1 C3435T polymorphism on PD risk alone or in combination with environmental factors. A total of 238 patients with PD and 368 controls were genotyped for the MDR1 C3435T polymorphism. Subjects with the TT genotype of the C3435T polymorphism showed a nonsignificantly increased risk of PD [odds ratio (OR)=1.49, 95% confidence interval (CI)=0.85-2.25] compared with those with the CC genotype. A gene-environment interaction was suggested, with a combination of at least one T allele and ever drinking conferring significantly higher risk (OR=1.83, 95% CI=1.07-3.15, p=0.029), compared with the CC genotype and never drinking. No significant interaction of smoking or occupational pesticide use with the C3435T polymorphism was observed. Our results suggest that the C3435T polymorphism may not play an important role in PD susceptibility in Japanese. Evidence of an interaction between the C3435T polymorphism and alcohol consumption was suggested.

In organic chemistry, Comparative Molecular Field Analysis (CoMFA) can be defined as a regression analysis between reaction outcomes and molecular fields, wherein we can extract and visualize important structural information from the coefficients of the constructed regression models. In CoMFA, partial least-squares (PLS) regression, which determines all coefficients in the model, is used for fitting the regression models. However, in organic reactions, steric effects are observed only near the reactive site, indicating that a large number of regression coefficients in the CoMFA of organic reactions should be assigned as 0. The regularized regression method, LASSO/Elastic Net, allows us to fit the regression model while assigning 0 values to unimportant coefficients. Although LASSO/Elastic Net should be suitable for CoMFA, there is no example of its use for organic reaction analysis. Herein, we examine the performance of LASSO/Elastic Net for the quantification of steric effects in CoMFA. We employ digitized molecular structures (the indicator field) as molecular fields that represent steric effects. LASSO/Elastic Net regressions provide highly interpretable models that include less noise than those from PLS regression. © 2017 Wiley Periodicals, Inc.

In petrochemical and nuclear power plants, inner surface of components, such as pressure vessels and piping, which are made of carbon steels or low-alloy steels, is often cladded by austenitic stainless steels to improve the corrosion resistance of those components. In the evaluation of a crack postulated near the inner surface of cladded components, the following two different kinds of cracks are often assumed: One is a surface crack penetrated through cladding and the other is a subsurface crack under cladding. In order to evaluate the structural integrity of those components in a rational manner, it is important to investigate the crack propagation behavior. In particular, it should be evaluated whether a subsurface crack penetrates through cladding or is arrested at the interface between cladding and base metal. In this study, ductile crack propagation analysis for a subsurface elliptical crack in cladded plates was performed using elastic-plastic XFEM, which can model the crack independent of finite elements.

Previous studies reported that exposure to dioxins was associated with an increased risk of various diseases in general populations. The aim of this study was to examine the association between levels of dioxins in blood and allergic and other diseases. We conducted a cross-sectional study on 1,063 men and 1,201 women (aged 15–76 years), who were living throughout Japan and not occupationally exposed to dioxins, during 2002–2010. In fasting blood samples, polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), and dioxin-like PCBs (DL-PCBs) were analyzed by isotope dilution high-resolution gas chromatography/mass spectrometry. We obtained information on life style and self-reported history of diseases using a questionnaire. Blood pressure, blood levels of hemoglobin A1c, and serum lipids were also measured. Multiple logistic regression models were used to analyze the association between dioxin levels in blood and various diseases. Toxic equivalents of PCDDs/PCDFs and total dioxins showed significant inverse dose–response relationships with atopic dermatitis, after adjustments for potential confounders. The highest quartile for total dioxins had an adjusted odds ratio of 0.26 (95 % confidence interval 0.08–0.70) compared to the reference group (first quartile). The odds ratios for hypertension, diabetes mellitus, hyperlipidemia, gout in men, and gynecologic diseases in women significantly increased with increasing toxic equivalents of PCDDs/PCDFs, DL-PCBs, and total dioxins in blood. The present findings suggest that background exposure to dioxins was associated with reduced risk of atopic dermatitis. The results also support the idea that low-level exposure to dioxins is associated with an increased risk of diabetes, hypertension, and hyperlipidemia.

A numerical method for evaluating the stress intensity factors (SIFs) of a three-dimensional interface crack between dissimilar anisotropic materials subjected to thermal and mechanical stresses is proposed. The M1-integral method was applied to an interfacial crack between three-dimensional anisotropic bimaterials under thermal stress. The moving least square approximation was utilized to calculate the value of the M1-integral. The M1-integral in conjunction with the moving least square approximation can be used to calculate the SIFs from nodal displacements obtained by finite element analysis. SIF analyses were performed for double edge cracks in jointed dissimilar isotropic semi-infinite plates subjected to thermal load. Excellent agreement was achieved between the numerical results obtained by the present method and the exact solution. In addition, we computed the SIFs of an external circular interfacial crack in jointed dissimilar anisotropic solids under thermal stress and showed the distributions of SIFs along the crack front. The distribution of stress and the crack opening displacement obtained by the asymptotic solution using the computed SIFs were compared with those obtained by the finite element analysis with fine mesh. They were almost identical to each other, except for the minor component of SIFs that is much smaller than the major component of SIFs. These results indirectly demonstrate the accuracy of the obtained SIFs.

The aim of this study was to describe age, gender distribution, and age at onset of systemic lupus erythematosus (SLE), polymyositis/dermatomyositis (PM/DM), and systemic sclerosis (SSc) in Japan. We used epidemiological information on 21,405, 6,327, and 10,058 patients with SLE, PM/DM, and SSc, respectively, in a Japanese nationwide registration database of patients with intractable diseases. All three diseases occur predominantly in women, with the female-to-male ratio being 8.2:1, 2.6:1, and 7.7:1 for SLE, PM/DM, and SSc, respectively. The most susceptible age for SLE is 15–44 and 20–39 years for males and females, respectively. For PM/DM it is 45–64 and 40–64 years and for SSc, 50–69 and 40–59 for men and women, respectively. The basic descriptive epidemiological characteristics of SLE, PM/DM, and SSc in Japan, such as gender distribution, present age, and age at onset, were surveyed nationwide for fiscal 2007. It was found that these characteristics were similar to those in Western populations. Our finding provides new information on the natural history of disease development.

A numerical method is proposed for evaluating the stress intensity factors of a three-dimensional bimaterial interfacial crack using tetrahedral finite elements. This technique is based on the M1-integral method and employs the moving least-squares approximation. Stress or strain in the M1-integral equation is automatically approximated from the nodal displacements obtained by the finite element analysis using the moving least-squares method. Therefore, the presented method needs no elemental information from the finite element analysis. In this study, stress intensity factor analyses of some typical three-dimensional interface crack problems using the tetrahedral finite elements are demonstrated.

Background: Nearly all epidemiologic studies examining the association between the risk of Parkinson’s disease (PD) and diet have focused on single foods and specific nutrients. However, epidemiologic evidence for the association of dietary pattern with PD, namely the measurement of overall diet by considering the cumulative effects of nutrients is extremely limited. We conducted a hospital-based case–control study in Japan to examine the relationship between dietary patterns and the risk of PD. Methods: Patients with PD diagnosed using the UK PD Society Brain Bank criteria (n = 249) and controls without neurodegenerative diseases (n = 368) were recruited. At the time of recruitment, dietary intake during the preceding 1 month was assessed using a validated, self-administered diet history questionnaire. Dietary patterns from 33 predefined food groups (energy-adjusted food g/day) were extracted by factor analysis. Results: Three dietary patterns were identified: ‘Healthy’, ‘Western’ and ‘Light meal’ patterns. After adjustment for potential non-dietary confounding factors, the Healthy pattern, characterized by a high intake of vegetables, seaweed, pulses, mushrooms, fruits and fish, was inversely associated with the risk of PD with a border-line significance (P for trend = 0.06). Multivariate Odds ratio (95% confidence intervals) for PD in the highest quartile of the Healthy pattern was 0.54 (0.32–0.92) compared with the lowest quartile. No associations with PD were detected for the other two dietary patterns. Conclusion: In this case–control study in Japan, a dietary pattern consisting of high intakes of vegetables, fruits and fish may be associated with a decreased risk of PD.

Apolipoprotein E (APOE) is associated with increased oxidative stress, which is caused by reactive oxygen species (ROS). Enhanced cytochrome P450 2E1 (CYP2E1) activity may also increase formation of neurotoxins such as ROS. As Parkinson’s disease (PD) is a neurodegenerative disorder, both the APOE and CYP2E1 genes that are involved in neurodegeneration by oxidative stress may be associated with PD risk. We investigated the relationship of the APOE and CYP2E1 rs2864987 polymorphisms and PD risk with special attention to the interaction with alcohol consumption among 238 patients with PD and 296 controls in a Japanese population. The frequencies of the ɛ2, ɛ3, and ɛ4 alleles of the APOE polymorphism among controls were 3.72, 86.7, and 9.63%, respectively. As compared with the APOE e3/e3 genotype, the 2/e4 genotype was associated with an increased risk of PD (adjusted odds ratio (OR) = 9.50, 95% (confidence interval) CI = 1.12–80.6). The presence of the e3 allele was associated with a decreased risk of PD. Meanwhile, CYP2E1 rs2864987 was not associated with PD risk. Although CYP2E1 is involved in the metabolism of alcohol, there was no evidence of interaction between alcohol consumption and CYP2E1 rs2864987. Our results suggested that the APOE polymorphism might play an important role in PD susceptibility in our Japanese population. Future studies involving larger control and case populations and better alcohol consumption histories will undoubtedly lead to a more thorough understanding of the role of polymorphisms of genes related to the generation of ROS in PD development.