Psychometrics of rating scales for externalizing disorders in Japanese outpatients: The ADHD-Rating Scale-5 and the Disruptive Behavior Disorders Rating Scale.

OBJECTIVES: This study validated the Japanese version of the Attention-Deficit/Hyperactivity Disorder-Rating Scale-5 (ADHD-RS-5) and the Disruptive Behavior Disorders Rating Scale. We extended the ADHD-RS-5 by adding the oppositional defiant disorder and conduct disorder subscales to compare the two rating scales psychometrically. METHODS: We examined the internal consistency, test-retest reliability, construct validity and criterion validity of the two rating scales in 135 Japanese outpatients aged 6-18 years. RESULTS: The internal consistency and test-retest reliability were good for all the subscales of the two rating scales except for the conduct disorder subscale of the ADHD-RS-5 extended. Good construct validity was revealed by expected correlational patterns between subscales from the two rating scales and the Children Behavior Checklist. The criterion validity was good for all the subscales of the two rating scales rated by parents, while teacher-ratings revealed substantially lower predictive ability for all the subscales. Agreement between parent- and teacher-ratings of the two rating scales was generally moderate and using predictive ratings alone of both ratings showed the best predictive ability among the integration methods examined. CONCLUSION: The two rating scales have sound psychometric properties and will aid in screening and severity assessment of externalizing disorders in Japanese clinical settings.

Positive association between blood glucose in physical examinations and self-reported fractures among middle-aged and elderly Japanese men: a prospective cohort study.

The association between blood glucose and fractures is not consistent across populations. Blood glucose was associated with fractures five years later in middle-aged and elderly men who underwent health examinations in Japan, respectively. Blood glucose-targeted fracture alerts are crucial for middle-aged and elderly individuals. OBJECTIVES: The evidence on blood glucose as a fracture risk marker has not been adequately examined in various populations, and there are no studies in middle-aged Japanese. We aimed to determine the association between blood glucose status and self-report fractures among middle-aged and elderly Japanese men. METHODS: The data from the Japan Multi-Institutional Collaborative Cohort (J-MICC) Okazaki Study were used. Hemoglobin A1c (HbA1c) and fasting plasma glucose (FPG) measured at baseline physical examinations were examined for association with fractures questioned five years later. Analyses were performed for the middle-aged and elderly respondents. RESULTS: The HbA1c was dichotomized into 290 (11.8%) with HbA1c ≥ 6.5% and 2165 (88.2%) with HbA1c < 6.5%. Compared to the group with an HbA1c < 6.5, the odds ratio for the risks of fracture among the group with an HbA1c ≥ 6.5% were 3.46 (95% confidence interval (CI), 1.75-6.84) in Model 1 (adjusted for age) and 3.60 (95% CI, 1.77-7.34) in Model 2 (adjusted for various confounding factors). These associations were also observed in both middle-aged and elderly generations, whereas no association was observed for FPG. CONCLUSIONS: Among Japanese men who have undergone physical examinations, those with an HbA1c of 6.5% or higher are at higher risk for fractures, and HbA1c-targeted fracture alerts are crucial for middle-aged and elderly individuals.

BMI and Cardiometabolic Traits in Japanese: A Mendelian Randomization Study.

BACKGROUND: Although many observational studies have demonstrated significant relationships between obesity and cardiometabolic traits, the causality of these relationships in East Asians remains to be elucidated. METHODS: We conducted individual-level Mendelian randomization (MR) analyses targeting 14,083 participants in the Japan Multi-Institutional Collaborative Cohort Study and two-sample MR analyses using summary statistics based on genome-wide association study data from 173,430 Japanese. Using 83 body mass index (BMI)-related loci, genetic risk scores (GRS) for BMI were calculated, and the effects of BMI on cardiometabolic traits were examined for individual-level MR analyses using the two-stage least squares estimator method. The ß-coefficients and standard errors for the per-allele association of each single-nucleotide polymorphism as well as all outcomes, or odds ratios with 95% confidence intervals were calculated in the two-sample MR analyses. RESULTS: In individual-level MR analyses, the GRS of BMI was not significantly associated with any cardiometabolic traits. In two-sample MR analyses, higher BMI was associated with increased risks of higher blood pressure, triglycerides, and uric acid, as well as lower high-density-lipoprotein cholesterol and eGFR. The associations of BMI with type 2 diabetes in two-sample MR analyses were inconsistent using different methods, including the directions. CONCLUSION: The results of this study suggest that, even among the Japanese, an East Asian population with low levels of obesity, higher BMI could be causally associated with the development of a variety of cardiometabolic traits. Causality in those associations should be clarified in future studies with larger populations, especially those of BMI with type 2 diabetes.

Association between awareness of limiting food intake and all-cause mortality: A cohort study in Japan.

BACKGROUND: Improving diets requires an awareness of the need to limit foods for which excessive consumption is a health problem. Since there are limited reports on the link between this awareness and mortality risk, we examined the association between awareness of limiting food intake (energy, fat, and sweets) and all-cause mortality in a Japanese cohort study. METHODS: Participants comprised 58,772 residents (27,294 men; 31,478 women) aged 35-69 years who completed baseline surveys of the Japan Multi-Institutional Collaborative Cohort Study from 2004 to 2014. Hazard ratios (HRs) for all-cause mortality and 95% confidence intervals (CIs) were estimated by sex using a Cox proportional hazard model, with adjustment for related factors. Mediation analysis with fat intake as a mediator was also conducted. RESULTS: The mean follow-up period was 11 years and 2,516 people died. Estimated energy and fat intakes according to the Food Frequency Questionnaire were lower in those with awareness of limiting food intake than in those without this awareness. Women with awareness of limiting fat intake showed a significant decrease in mortality risk (HR=0.73; 95% CI, 0.55 to 0.94). Mediation analysis revealed that this association was due to the direct effect of the awareness of limiting fat intake and that the total effect was not mediated by actual fat intake. Awareness of limiting energy or sweets intake was not related to mortality risk reduction. CONCLUSION: Awareness of limiting food intake had a limited effect on reducing all-cause mortality risk.

GWAS of folate metabolism with gene-environment interaction analysis revealed the possible role of lifestyles in the control of blood folate metabolites in Japanese - the J-MICC Study.

BACKGROUND: The present genome-wide association study (GWAS) aimed to reveal the genetic loci associated with folate metabolites as well as to detect related gene-environment interactions in Japanese. METHODS: We conducted the GWAS of plasma homocysteine (Hcy), folic acid (FA), and vitamin B12 (VB12) levels in the Japan Multi-Institutional Collaborative Cohort (J-MICC) Study participants who joined from 2005 to 2012, and also estimated gene-environment interactions. In the replication phase, we used data from the Yakumo Study conducted in 2009. In the discovery phase, data of 2,263 participants from four independent study sites of the J-MICC Study were analyzed. In the replication phase, data of 573 participants from the Yakumo Study were analyzed. RESULTS: For Hcy, MTHFR locus on chr 1, NOX4 on chr 11, CHMP1A on chr 16, and DPEP1 on chr 16 reached genome-wide significance (P < 5×10-8). MTHFR also associated with FA, and FUT2 on chr 19 associated with VB12. We investigated gene-environment interactions in both studies and found significant interactions between MTHFR C677T and ever drinking, current drinking, and physical activity > 33% on Hcy (ß = 0.039, 0.038 and -0.054, P = 0.018, 0.021 and < 0.001, respectively) and the interaction of MTHFR C677T with ever drinking on FA (ß = 0.033, P = 0.048). CONCLUSIONS: The present GWAS revealed the folate metabolism-associated genetic loci and gene-environment interactions with drinking and physical activity in Japanese, suggesting the possibility of future personalized CVD prevention.

Possible contribution of phosphate to the pathogenesis of chronic kidney disease in dolphins.

This study aimed to investigate whether phosphate contributes to the pathogenesis of chronic kidney disease (CKD) in dolphins. Renal necropsy tissue of an aged captive dolphin was analyzed and in vitro experiments using cultured immortalized dolphin proximal tubular (DolKT-1) cells were performed. An older dolphin in captivity died of myocarditis, but its renal function was within the normal range until shortly before death. In renal necropsy tissue, obvious glomerular and tubulointerstitial changes were not observed except for renal infarction resulting from myocarditis. However, a computed tomography scan showed medullary calcification in reniculi. Micro area X-ray diffractometry and infrared absorption spectrometry showed that the calcified areas were primarily composed of hydroxyapatite. In vitro experiments showed that treatment with both phosphate and calciprotein particles (CPPs) resulted in cell viability loss and lactate dehydrogenase release in DolKT-1 cells. However, treatment with magnesium markedly attenuated this cellular injury induced by phosphate, but not by CPPs. Magnesium dose-dependently decreased CPP formation. These data support the hypothesis that continuous exposure to high phosphate contributes to the progression of CKD in captive-aged dolphins. Our data also suggest that phosphate-induced renal injury is mediated by CPP formation in dolphins, and it is attenuated by magnesium administration.

Association between Dietary Patterns and Serum Low Density Lipoprotein Cholesterol in Japanese Women and Men: The Japan Multi-Institutional Collaborative Cohort (J-MICC) Study.

AIMS: The association between dietary patterns and serum low density lipoprotein (LDL) cholesterol would be changing in recent dietary habits in Japan. We investigated the relationship between dietary patterns and serum LDL cholesterol in a large general population. METHODS: From the baseline survey of Japan Multi-Institutional Collaborative Cohort Study between 2005 and 2013, 27,237 participants (13,994 were women) aged 35-69 years were cross-sectionally analyzed. Using a semi-quantitative food frequency questionnaire, five major sex-specific dietary patterns were identified using factor analysis. We assessed serum LDL cholesterol by quintiles of dietary pattern factor score. RESULTS: We identified dietary patterns; "vegetable rich pattern" , "meat and fried food rich pattern" and "high bread and low rice pattern" in women and men; "fish and shellfish rich pattern" and "high confectioneries and low alcohol pattern" in men; "healthy Japanese diet pattern" and "high alcohol and low rice pattern" in women. Serum LDL cholesterol in men was associated with "high bread and low rice pattern" score (Q5 was 4.2 mg/dL higher than Q1, p for trend ＜0.001) and "high confectioneries and low alcohol pattern" scores (Q5 was 9.5 mg/dL higher than Q1, p for trend ＜0.001). In women, serum LDL cholesterol was associated with "high bread and low rice pattern" score (Q5 was 7.1 mg/dL higher than Q1, p for trend ＜0.001). CONCLUSION: Some recent dietary patterns in Japan were associated with serum LDL cholesterol. Serum LDL cholesterol was associated with high bread and low rice pattern in both sex, and high confectioneries and low alcohol pattern in men.

Psychometrics of the kiddie schedule for affective disorders and schizophrenia present and lifetime version for DSM-5 in Japanese outpatients.

OBJECTIVE: The Schedule for Affective Disorders and Schizophrenia for School-Age Children-Present and Lifetime version (K-SADS-PL) is a widely used semi-structured diagnostic interview in child and adolescent psychiatry. However, the psychometric properties of its updated version, the K-SADS-PL for DSM-5, have scarcely been examined, especially for criterion validity. This study was designed to examine the inter-rater reliability, criterion validity and construct validity of the K-SADS-PL for DSM-5 in 137 Japanese outpatients. METHODS: Two of 12 experienced clinicians independently performed the K-SADS interview for each patient in a conjoint session, and the resulting consensus diagnosis was compared with a "best-estimate" diagnosis made by two of eight experienced clinicians using all available information for the patient. RESULTS: The inter-rater reliability was excellent, as shown by κ > 0.75 for all disorders, with the exception of current separation anxiety disorder. The criterion validity was fair to good, as shown by κ > 0.40 for all disorders, with the exception of current and lifetime agoraphobia. The construct validity was also good, as shown by theoretically expected associations between the K-SADS-PL diagnoses and subscales of the child behavior checklist. CONCLUSION: The K-SADS-PL for DSM-5, now available in Japanese, generates valid diagnoses in child and adolescent psychiatry.

Novel WNT10A variant in a Japanese case of nonsyndromic oligodontia.

Congenital tooth agenesis is one of the most common anomalies in humans. Many genetic factors are involved in tooth development, including MSX1, PAX9, WNT10A, and LRP6. Thus, mutations in these genes can cause congenital tooth agenesis in humans. In this study, we identified a novel nonsense WNT10A variant, NM_025216.3(WNT10A_v001):c.1090A > T, which produces a C-terminal truncated gene product, p.(Lys364*), in a sporadic form of congenital tooth agenesis. The variant was not found in the healthy parents and thus was considered to cause congenital tooth agenesis in the case.

Sex-specific Relationship Between Stress Coping Strategies and All-cause Mortality: Japan Multi-Institutional Collaborative Cohort Study.

BACKGROUND: Stress coping strategies are related to health outcomes. However, there is no clear evidence for sex differences between stress-coping strategies and mortality. We investigated the relationship between all-cause mortality and stress-coping strategies, focusing on sex differences among Japanese adults. METHODS: A total of 79,580 individuals aged 35-69 years participated in the Japan Multi-Institutional Collaborative Cohort Study between 2004 and 2014 and were followed up for mortality. The frequency of use of the five coping strategies was assessed using a questionnaire. Sex-specific, multivariable-adjusted hazard ratios (HRs) for using each coping strategy ("sometimes," and "often/very often" use versus "very few" use) were computed for all-cause mortality. Furthermore, relationships were analyzed in specific follow-up periods when the proportion assumption was violated. RESULTS: During the follow-up (median: 8.5 years), 1,861 mortalities were recorded. In women, three coping strategies were related to lower total mortality. The HRs for "sometimes" were 0.81 (95% confidence interval [CI], 0.67-0.97) for emotional expression, 0.79 (95% CI, 0.66-0.95) for emotional support-seeking, and 0.80 (95% CI, 0.66-0.98) for disengagement. Men who "sometimes" used emotional expression and sometimes or often used problem-solving and positive reappraisal had a 15-41% lower HRs for all-cause mortality. However, those relationships were dependent on the follow-up period. There was evidence that sex modified the relationships between emotional support-seeking and all-cause mortality (P for interaction = 0.03). CONCLUSION: In a large Japanese sample, selected coping strategies were associated with all-cause mortality. The relationship of emotional support-seeking was different between men and women.

A nationwide survey of Schaaf-Yang syndrome in Japan.

Schaaf-Yang syndrome (SYS) is a congenital disorder characterized by developmental delay, autism spectrum disorder and congenital joint contractures. In this study, a nationwide epidemiological questionnaire-based survey of SYS in the Japanese population was conducted to establish patient numbers, clinical features and genetic information. In the primary survey, we investigated the number of SYS patients. In the secondary survey, we obtained and analyzed detailed clinical and genetic information of SYS patients. This survey collected information on 25 genetically-confirmed patients. The major clinical symptoms included neonatal hypotonia (96% of the patients), poor suck in infancy (82%), developmental delay (100%) and joint contractures (83%). Other main symptoms and findings included characteristic facial features (100%), small hands (92%), eye abnormalities (92%) and short stature (79%). Based on the information collected on activities of daily living, 71% of patients were unable to walk, while 67%, 71%, and 81% of patients required full assistance with eating, toileting and bathing, respectively. Regarding inheritability, the genetic analysis of 21 patients revealed that 14 (67%) carried de novo truncating variants in the melanoma antigen L2 (MAGEL2) gene and seven (33%) had inherited truncating variants from their fathers who were carriers. This survey revealed the clinical and genetic features in Japanese SYS patients. The majority of SYS patients required assistance in many aspects of daily living, and there were a certain number of carriers of the imprinting disorder.

Associations between Work-Related Factors and Happiness among Working Older Adults: A Cross-Sectional Study.

BACKGROUND: As the global population ages, the number of older adults working after retirement is increasing. However, knowledge regarding working conditions for health and happiness among this population is insufficient. Therefore, we examined the association between work-related factors (e.g., employment status, daily working time, work-related stress) and happiness among working older adults. METHODS: This cross-sectional study recruited Japanese older adults, aged 65 years and older, who were engaged in paid work, during their annual health checkups. Self-administered questionnaires were used to assess happiness, employment status, daily working time, and work-related stress (i.e., job strain, job control, job suitability, and relationships at work). RESULTS: The data of 520 men and 168 women were analyzed (mean ages, 68.5 years and 68.0 years, respectively). The results of the multivariable ordinal logistic regression analysis indicated that low job suitability was negatively associated with happiness in men (odds ratio [OR]=0.46; 95% confidence interval [CI], 0.28-0.78; p=0.004). In women, long working hours and low job control were negatively associated with happiness-working >8 hours daily (OR=0.29; 95% CI, 0.12-0.71; p=0.008) and low job control (OR=0.29; 95% CI, 0.12-0.72; p=0.009). CONCLUSION: The results showed that low job suitability for men and long daily working time and low job control for women were negatively associated with happiness. These findings suggest the need to improve working conditions to enhance the well-being of working older adults.

Associations of metabolic syndrome and metabolically unhealthy obesity with cancer mortality: The Japan Multi-Institutional Collaborative Cohort (J-MICC) study.

PURPOSE: The association between metabolic syndrome (MetS) and the risk of death from cancer is still a controversial issue. The purpose of this study was to examine the associations of MetS and metabolically unhealthy obesity (MUHO) with cancer mortality in a Japanese population. METHODS: We used data from the Japan Multi-Institutional Collaborative Cohort Study. The study population consisted of 28,554 eligible subjects (14,103 men and 14,451 women) aged 35-69 years. MetS was diagnosed based on the criteria of the National Cholesterol Education Program Adult Treatment Panel III (NCEP-ATP III) and the Japan Society for the Study of Obesity (JASSO), using the body mass index instead of waist circumference. The Cox proportional hazards analysis was used to estimate adjusted hazard ratios (HR) and 95% confidence intervals (CI) for total cancer mortality in relation to MetS and its components. Additionally, the associations of obesity and the metabolic health status with cancer mortality were examined. RESULTS: During an average 6.9-year follow-up, there were 192 deaths from cancer. The presence of MetS was significantly correlated with increased total cancer mortality when the JASSO criteria were used (HR = 1.51, 95% CI 1.04-2.21), but not when the NCEP-ATP III criteria were used (HR = 1.09, 95% CI 0.78-1.53). Metabolic risk factors, elevated fasting blood glucose, and MUHO were positively associated with cancer mortality (P <0.05). CONCLUSION: MetS diagnosed using the JASSO criteria and MUHO were associated with an increased risk of total cancer mortality in the Japanese population.

Performance Status Modifies the Association Between Vitamin D Receptor Activator and Mortality or Fracture: A Prospective Cohort Study on the Japanese Society for Dialysis Therapy (JSDT) Renal Data Registry.

Immobilization osteoporosis is characterized by excess bone resorption. Vitamin D receptor activators (VDRA) might have adverse effects in immobilized patients. The objective of this study was to elucidate the impact of performance status (PS) on the associations between VDRA use and outcomes among hemodialysis patients. This is a prospective cohort study. Adults on hemodialysis in the Japanese Society for Dialysis Therapy (JSDT) Renal Data Registry were included. Exposure of interest was the use of VDRA. Outcomes were all-cause mortality and hip fracture. Associations between VDRA use and mortality or hip fractures were examined by Cox and Poisson regression analyses, respectively. Among 208,512 subjects, 128,535 were on VDRA. Poor PS was associated with higher calcium (Ca), lower parathyroid hormone, and higher alkaline phosphatase levels. The association between higher Ca levels and VDRA use was stronger among those with poor PS (p interaction 0.007). Adjusted hazard ratio (HR) (95% confidence interval [CI]) for mortality and incidence rate ratio (IRR) for hip fracture was 1.02 (95% CI, 0.99-1.05) and 0.93 (0.86-1.00) among users of VDRA, respectively. The VDRA use was associated with lower mortality and incidence of hip fractures among subjects with good PS but not among subjects with poor PS (p interaction 0.03 and 0.05). Effect modification by PS was observed for cardiovascular (CV) mortality but not for non-CV mortality. In conclusion, VDRA use was associated with better outcomes only among those with good PS. These results suggest that bone and mineral disorders among hemodialysis patients should be treated differently, depending on their performance status. © 2022 American Society for Bone and Mineral Research (ASBMR).

The Impact of Marital Transitions on Vegetable Intake in Middle-aged and Older Japanese Adults: A 5-year Longitudinal Study.

BACKGROUND: Marital transitions are associated with adverse health events, such as mortality and cardiovascular disease. Since marital transitions (eg, becoming widowed) are unavoidable life events, it is necessary to identify modifiable intermediate outcomes. Thus, we examined the association between marital transitions and vegetable intake among middle-aged and older Japanese adults. METHODS: This longitudinal study included Japanese adults aged 40-79 years who received an annual health checkup between 2007 and 2011 (baseline) and 5 years later (follow-up). Marital transitions were classified as whether and what type of transition occurred during the 5-year period and comprised five groups: consistently married, married to widowed, married to divorced, not married to married, and remained not married. Changes in total vegetable, green and yellow vegetable, and light-colored vegetable intake from baseline to follow-up were calculated using the Food Frequency Questionnaire. RESULTS: Data from 4,813 participants were analyzed (mean age, 59.4 years; 44.1% women). Regarding marital transitions, 3,960 participants were classified as "consistently married," 135 as "married to widowed," 40 as "married to divorced," 60 as "not married to married," and 529 as "remained not married." Multivariable linear regression analysis revealed that compared to consistently married, married to widowed was inversely associated with the change in total vegetable intake (ß = -16.64, SE = 7.68, P = 0.030) and light-colored vegetable intake (ß = -11.46, SE = 4.33, P = 0.008). CONCLUSION: Our findings suggest that being widowed could result in a reduced intake of vegetables. Hence, dietary counseling according to marital situation is necessary.

Assessing the Relationship Between High-sensitivity C-reactive Protein and Kidney Function Employing Mendelian Randomization in the Japanese Community-based J-MICC Study.

BACKGROUND: Inflammation is thought to be a risk factor for kidney disease. However, whether inflammatory status is either a cause or an outcome of chronic kidney disease remains controversial. We aimed to investigate the causal relationship between high-sensitivity C-reactive protein (hs-CRP) and estimated glomerular filtration rate (eGFR) using Mendelian randomization (MR) approaches. METHODS: A total of 10,521 participants of the Japan Multi-institutional Collaborative Cohort Study was analyzed in this study. We used two-sample MR approaches (the inverse-variance weighted (IVW), the weighted median (WM), and the MR-Egger method) to estimate the effect of genetically determined hs-CRP on kidney function. We selected four and three hs-CRP associated single nucleotide polymorphisms (SNPs) as two instrumental variables (IV): IVCRP and IVAsian, based on SNPs previously identified in European and Asian populations. IVCRP and IVAsian explained 3.4% and 3.9% of the variation in hs-CRP, respectively. RESULTS: Using the IVCRP, genetically determined hs-CRP was not significantly associated with eGFR in the IVW and the WM methods (estimate per 1 unit increase in ln(hs-CRP), 0.000; 95% confidence interval [CI], -0.019 to 0.020 and -0.003; 95% CI, -0.019 to 0.014, respectively). For IVAsian, we found similar results using the IVW and the WM methods (estimate, 0.005; 95% CI, -0.020 to 0.010 and -0.004; 95% CI, -0.020 to 0.012, respectively). The MR-Egger method also showed no causal relationships between hs-CRP and eGFR (IVCRP: -0.008; 95% CI, -0.058 to 0.042; IVAsian: 0.001; 95% CI, -0.036 to 0.036). CONCLUSION: Our two-sample MR analyses with different IVs did not support a causal effect of hs-CRP on eGFR.

Application of the RNA interference technique to Xenopus embryos: Specific reduction of the ß-catenin gene products by short double-stranded RNA produced by recombinant human Dicer.

RNA interference (RNAi) is a technique for suppressing the function of specific genes and is widely used in many organisms, including yeast, nematodes, flies, plants, mice, and cultured mammalian cells. As of date, this technique has not been successfully applied to Xenopus laevis embryos. In this study, we applied RNAi to Xenopus embryos using ß-catenin as a model gene. Injection of long double-stranded RNA (dsRNA) corresponding to the 3'-untranslated region of ß-catenin mRNA into embryos induced embryonic lethality without any specific phenotype. However, injection of short dsRNA, generated from long dsRNA by treatment with recombinant human Dicer, into embryos resulted in decreased expression of endogenous ß-catenin mRNA and protein, as well as decreased Wnt signaling activity in the embryos. The decrease in ß-catenin mRNA and protein levels was observed only after mid-blastula transition. Embryos injected with short dsRNA showed a characteristic phenotype of enlarged anterior structures and loss of posterior structures. These phenotypes, as well as the increased expression of the anterior gene and decreased expression of the posterior gene, suggest that RNAi against the ß-catenin gene suppresses the "late Wnt signaling" involved in proper anterior-posterior patterning of Xenopus embryos. The effect of RNAi on Xenopus embryos was also found to be sensitive to temperature. These results strongly suggest that the RNAi technique can be applied to Xenopus embryos using short dsRNAs, appropriate temperature control, and proper selection of target genes.

Novel MSX1 frameshift mutation in a Japanese family with nonsyndromic oligodontia.

Congenital tooth agenesis is a common anomaly in humans. We investigated the etiology of human tooth agenesis by exome analysis in Japanese patients, and found a previously undescribed heterozygous deletion (NM_002448.3(MSX1_v001):c.433_449del) in the first exon of the MSX1 gene. The deletion leads to a frameshift and generates a premature termination codon. The truncated form of MSX1, namely, p.(Trp145Leufs*24) lacks the homeodomain, which is crucial for transcription factor function.

The Impact of Job Conditions on Health-Related Quality of Life among Working Japanese Older Adults: A Five-Year Longitudinal Study Using J-MICC Okazaki Study Data.

OBJECTIVES: The number of older adults who continue working after retirement is increasing in Japan. Little is known about how job conditions affect older adults' health. We examined the association between job conditions and health-related quality of life (HRQOL) during a five-year follow-up study. METHODS: This study included participants aged 65 years or older from the Japan Multi-Institutional Collaborative Cohort Study in the Okazaki area recruited at baseline between 2007 and 2011 and followed up five years later. Participants completed a self-reported questionnaire on the physical and mental health aspects of HRQOL (SF-8™), employment status, and job conditions (job satisfaction, skill use, and job suitability). RESULTS: Data of 1,146 men and 522 women were analyzed (mean age: 69.1 and 68.6 years, respectively). Generalized mixed linear regression analysis revealed that, compared to the not-working group, skill use was positively associated with mental health aspects among men (skill use × time: ß = 0.16, SE = 0.08, p < 0.05), while poor job satisfaction and job suitability were negatively associated with mental health aspects among women (job satisfaction, not satisfied × time: ß = -0.93, SE = 0.47, p < 0.05; job suitability, not suitable × time: ß = -1.06, SE = 0.50, p < 0.05). CONCLUSIONS: Regarding job conditions among older adults, skill use in men was marginally associated with mental health, and poor job satisfaction and suitability in women were negatively associated with mental health. Considering the job conditions of older workers is necessary to protect their mental health.

Genome-wide association study of serum prostate-specific antigen levels based on 1000 Genomes imputed data in Japanese: the Japan Multi-Institutional Collaborative Cohort Study.

Prostate cancer is emerging as a significant global public health burden. The incidence and prevalence of prostate cancer has increased in Japan, as westernized lifestyles become more popular. Recent advances in genetic epidemiology, including genome-wide association studies (GWASs), have identified considerable numbers of human genetic factors associated with diseases. Several GWASs have reported significant loci associated with serum prostate-specific antigen (PSA) levels. One GWAS, which was based on classic GWAS microarray measurements, has been reported for Japanese so far. In the present study, we conducted a GWAS of serum PSA using 1000Genomes imputed GWAS data (n =1,216) from the Japan Multi-Institutional Collaborative Cohort (J-MICC) Study, to detect candidate novel genetic loci that influence serum PSA levels in Japanese. The association of SNPs/genetic variants with serum PSA as a continuous variable was tested using the linear Wald test. SNP rs10000006 in SGMS2 (sphingomyelin synthase 2) on chromosome 4 had genome-wide significance (P <5×10-8), and eight variants on three chromosomes (chromosomes 12, 14, 15) had genome-wide suggestive levels of significance (P <1×10-6). With an independent data set from the J-MICC Shizuoka Study (n = 2,447), the association of the SGMS2 SNP with blood PSA levels was not replicated. Although our GWAS failed to detect novel loci associated with serum PSA levels in the Japanese cohort, it confirmed the significant effects of previously reported genetic loci on PSA levels in Japanese. Importantly, our results confirmed the significance of KLK3 SNPs also in Japanese, implying that consideration of individual genetic information in prostate cancer diagnosis may be possible in the future.