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Background: There is global concern over significant threats from a wide variety of environmental hazards to which children face. Large-scale and long-term birth cohort studies are needed for better environmental management based on sound science. The primary objective of the Japan Environment and Children's Study (JECS), a nation-wide birth cohort study that started its recruitment in January 2011, is to elucidate environmental factors that affect children's health and development., Methods/design: Approximately 100,000 expecting mothers who live in designated study areas will be recruited over a 3-year period from January 2011. Participating children will be followed until they reach 13 years of age. Exposure to environmental factors will be assessed by chemical analyses of bio-specimens (blood, cord blood, urine, breast milk, and hair), household environment measurements, and computational simulations using monitoring data (e.g. ambient air quality monitoring) as well as questionnaires. JECS' priority outcomes include reproduction/pregnancy complications, congenital anomalies, neuropsychiatric disorders, immune system disorders, and metabolic/endocrine system disorders. Genetic factors, socioeconomic status, and lifestyle factors will also be examined as covariates and potential confounders. To maximize representativeness, we adopted provider-mediated community-based recruitment., Discussion: Through JECS, chemical substances to which children are exposed during the fetal stage or early childhood will be identified. The JECS results will be translated to better risk assessment and management to provide healthy environment for next generations.

From 2003 through 2005, we compared annual mean particulate matter (PM) and nitrogen dioxide (NO₂) concentrations as measured at fixed-site monitoring stations in 6 Japanese cities with those measured inside and outside subject residences and during personal monitoring. A total of 65 households participated in indoor and outdoor residential exposure monitoring. In summer and autumn, we also performed personal monitoring of one resident of each household. On each day, personal samplers were used to collect 24-h samples of PM and NO₂ simultaneously from the fixed sites, indoor and outdoor, and from those undergoing personal monitoring. We found good correlations between the fixed-site and outdoor measurements for annual mean (average of 7-day × 4-season) concentrations of PM₂.₅, PM₁₀₋₂.₅, PM10 and NO₂ (Spearman's rank correlation coefficients (ρ) ≥ 0.75). However, the correlations between the fixed-site and indoor measurements were moderate to low. In summer and autumn, the correlations between the fixed-site and personal mean concentrations of PM₂.₅ (ρ = 0.62), PM10 (ρ = 0.58), and NO₂ (ρ = 0.70) were acceptable. However, because people spend most of their time indoors, these correlations for annual mean concentrations were not estimated to be high. Our results are important in allowing researchers to estimate the effects of resulting measurement errors of PM and NO₂., (© 2013.)

Background: Excess body weight is an independent risk factor for primary liver cancer, and the role of adiponectin in the pathogenesis of obesity-related malignancies is a focus of research interest. Few prospective studies have examined the association between circulating adiponectin and liver cancer risk, so we investigated this association in a nested case-control study of a population-based prospective cohort in Japan., Methods: From 18,628 target participants of ages 40 to 69 years who returned the baseline questionnaire and provided blood samples, we selected those with either hepatitis B or C virus infection at baseline (n = 1,544). Among these, 90 were newly diagnosed with primary liver cancer from 1993 through 2006, and matched to 177 controls. The ORs of liver cancer development based on plasma levels of adiponectin were estimated with a conditional logistic regression model., Results: Median values of total and high-molecular-weight (HMW) adiponectin tended to be higher in the patients with liver cancer, and plasma levels of adiponectin were positively associated with liver cancer risk. Body mass index- and diabetes-adjusted ORs for the highest tertile of total and HMW adiponectin levels versus the lowest were 3.30 [95% confidence interval (CI), 1.45-7.53; Ptrend < 0.01] and 3.41 (95% CI, 1.50-7.73; Ptrend < 0.01), respectively. There was no effect modification by body mass index and diabetes., Conclusions: Higher plasma adiponectin levels were associated with an increased risk of primary liver cancer in middle-aged Japanese adults with hepatitis virus infection., Impact: Circulating adiponectin levels may be a risk marker for primary liver cancer., (©2013 AACR.)

Inorganic arsenic is known to be a human carcinogen. Previous studies have reported that DNA methylation changes are involved in arsenic-induced carcinogenesis, therefore, DNA methylation changes that are specific to arsenic-induced tumors would be useful to distinguish tumors induced by arsenic from tumors caused by other factors and to dissect arsenic carcinogenesis. Previous studies have shown that gestational arsenic exposure of C3H mice, which tend to spontaneously develop liver tumors, increases the incidence of tumors in male offspring. In this study we used the same experimental protocol as in those previous studies and searched for DNA regions where methylation status was specifically altered in the liver tumors of arsenic-exposed offspring by using methylated DNA immunoprecipitation-CpG island microarrays. The methylation levels of the DNA regions selected were measured by quantitative methylation-specific PCR and bisulfite sequencing. The results of this study clarified a number of regions where DNA methylation status was altered in the liver tumors in the C3H mice compared to normal liver tissues. Among such regions, we showed that a gene body region of the oncogene Fosb underwent alteration in DNA methylation by gestational arsenic exposure. We also showed that Fosb expression significantly increased corresponding to the DNA methylation level of the gene body in the arsenic-exposed group. These findings suggest that the DNA methylation status can be used to identify tumors increased by gestational arsenic exposure., (© 2013 Japanese Cancer Association.)

Objective: Dehydroepiandrosterone sulfate (DHEAS) appears to have a protective effect against depression, but evidence from prospective cohort studies is sparse. Therefore, we examined the association between serum DHEAS levels and depressive symptoms in older community-dwelling Japanese., Design: A community-based cohort study., Setting: Kurabuchi Town, Gunma Prefecture, Japan., Participants: A total of 554 residents (248 men and 306 women) age 65 years or older without depressive symptoms at baseline., Measurements: We performed a baseline examination of the subjects between 2005 and 2006 to determine serum DHEAS levels. The subjects were categorized into three groups based on age strata- and sex-specific tertiles of DHEAS. Depressive symptoms were assessed with the Geriatric Depression Scale 15-item version (GDS-15) in face-to-face home visit interviews carried out once in 2007 and once in 2008. The association of DHEAS with depressive symptoms (GDS-15 ≥ 6) was analyzed with the use of logistic regression models., Results: The incidence of depressive symptoms was 12.1% in men and 19.6% in women. In men, the multiadjusted odds ratio of depressive symptoms was 0.24 (95% confidence interval: 0.06-0.94, Wald χ2 = 4.20, degrees of freedom = 1, p = 0.04) for the highest tertile compared with the lowest. The association observed for the highest versus the lowest remained significant even after adjustment for physical performance and cognitive function. In women, DHEAS was not associated with depressive symptoms., Conclusions: In this study, higher serum DHEAS levels were found to be protectively and independently associated with the risk of developing depressive symptoms in men, but not in women., (Copyright © 2013 American Association for Geriatric Psychiatry. Published by Elsevier Inc. All rights reserved.)

While hearing aids are recommended for people with age-related hearing loss, many with impaired hearing do not use them. In this study, we investigated how many elderly people in the study area needed hearing aids, and the factors that determined continued wearing of the devices. The study area was Kurabuchi Town, Japan, where 1,437 residents (those aged 65 years or over) were eligible for participation in the study; 1,414 participated, of whom, 103 (7.3%) were already using hearing aids at the start of the study. After the primary screening, hearing aids were lent to 68 participants (4.8%) who did not already have one, 38 of whom (60.3% of the borrowers, representing 2.7% of the total aged population) went on to wear the hearing aid continuously. The Hearing Handicap Inventory for the Elderly (HHIE) score was significantly elevated among these 38 participants. This study indicated that hearing aids are of potential benefit to many local residents. Multivariate logistic regression revealed that HHIE scores were associated with the extent of HA usage. The adjusted odds ratio for a 1-unit increase in HHIE score was 1.08 (95% confidence interval: 1.02-1.14). Programs like this, in which people with impaired hearing are identified at the local level and given appropriate assistance, are useful models for future use in societies with aging populations.

Monitoring the pattern of intracellular Ca(2+) signals that control many diverse cellular processes is essential for understanding regulatory mechanisms of cellular functions. Various genetically encoded Ca(2+) indicators (GECIs) are used for monitoring intracellular Ca(2+) changes under several types of microscope systems. However, it has not yet been explored which microscopic system is ideal for long-term imaging of the spatiotemporal patterns of Ca(2+) signals using GECIs. We here compared the Ca(2+) signals reported by a fluorescence resonance energy transfer (FRET)-based ratiometric GECI, yellow cameleon 3.60 (YC3.60), stably expressed in DT40 B lymphocytes, using three different imaging systems. These systems included a wide-field fluorescent microscope, a multipoint scanning confocal system, and a single-point scanning confocal system. The degree of photobleaching and the signal-to-noise ratio of YC3.60 in DT40 cells were highly dependent on the fluorescence excitation method, although the total illumination energy was maintained at a constant level within each of the imaging systems. More strikingly, the Ca(2+) responses evoked by B-cell antigen receptor stimulation in YC3.60-expressing DT40 cells were different among the imaging systems, and markedly affected by the illumination power used. Our results suggest that optimization of the imaging system, including illumination and acquisition conditions, is crucial for accurate visualization of intracellular Ca(2+) signals., (Copyright © 2013 Elsevier Inc. All rights reserved.)

Objective: Most studies of the association between tinnitus and depression have been cross-sectional, making it difficult to draw any conclusions about the directionality of the association. This study aimed to clarify whether tinnitus precedes the development of depressive symptoms in a general older population., Methods: Residents of Kurabuchi Town, Gunma Prefecture, Japan (239 men, 296 women: ≥65years) without depressive symptoms were given health examinations in 2005-2006. Information on tinnitus was obtained via a questionnaire. Depressive symptoms were then assessed in a face-to-face home visit interviews carried out once in 2007 and once in 2008 according to the Geriatric Depression Scale 15-item version (GDS15)., Results: Among the men, the 2.5-year incidence of depressive symptoms (GDS15≥6) was higher in those with tinnitus than in those without (20.5% vs. 9.5%). In the multi-adjusted model, tinnitus was significantly associated with an increased risk of depressive symptoms (relative risk=2.07; 95% confidence interval=1.01-4.25). Among the women, no associations were found., Conclusion: In the present study, tinnitus was independently associated with the risk of depressive symptoms developing in men, but not in women. We believe primary care providers and public health staff should recognize tinnitus as a risk factor for depressive symptoms., (Copyright © 2013 Elsevier Inc. All rights reserved.)

Aim: Associations between long-term exposure to particulate matter (PM) and increased cardiovascular mortality have been reported, but few studies have investigated the associated incidence of cardiovascular disease, and none involved men., Methods: We used data on 78,057 participants (37,121 men, 40,936 women) to examine the associations of long-term exposure to PM with mortality and the incidence of cardiovascular diseases. Average PM levels in the relevant area during the study period were used as an index of individual exposure to each subject. Cox models adjusted for age, sex, smoking, environmental smoking, body mass index, and alcohol consumption were used, with further adjustments for nitrogen dioxide and sulfur dioxide exposure, systolic blood pressure, total cholesterol, and diabetes mellitus., Results: Increased PM levels were associated with an increased risk of incident coronary heart disease (CHD) and myocardial infarction (MI), particularly among smokers (adjusted hazard ratio (HR) per 10 µg/m(3) increase in PM for CHD: 1.39, 95% confidence interval (CI) 1.01-1.93; for MI: 1.52, 1.08-2.13) and among women (for CHD: 1.63, 0.91-2.92; for MI: 1.99, 1.07-3.70); however, the observed positive association of PM exposure with the incidence of CHD and MI was not robust, and the association disappeared when one of the areas (Akita) was excluded. The association with CHD mortality was not statistically significant (adjusted HR per 10 µg/m(3) increase in PM: 1.11, 0.92-1.33). There was an inverse association of long-term PM exposure with stroke mortality and incidence. There was no clear association between PM levels and lung cancer mortality and incidence., Conclusions: Long-term exposure to PM might increase the risk of incident CHD in middle-aged Japanese men and women. Our findings also suggest that women and smokers are especially vulnerable to PM exposure.

Objective: The purpose of the present study was to develop a risk estimation model for the 10-year risk of hepatocellular carcinoma (HCC) that could be easily used in a general population to aid in the prevention of HCC., Methods: Our prediction model was derived from data obtained on 17,654 Japanese aged 40 to 69 years who participated in health checkups (follow-up: 1993-2006). Cox proportional hazards regression was applied to obtain coefficients for each predictor., Results: During follow-up, a total of 104 cases of HCC were newly diagnosed. After checking the model fit, we incorporated age, sex, alcohol consumption, body mass index, diabetes, coffee consumption, and hepatitis B and C virus infection into the prediction model. The model showed satisfactory discrimination (Harrell's c-index=0.94) and was well calibrated (the overall observed/expected ratio=1.03, 95% confidence interval=0.83-1.29). We also developed a simple risk scoring system. Those subjects with total scores of 17 or more under this system (score range: -1 to 19) had an estimated 10-year HCC risk of over 90%; those with 4 points or less had an estimated risk of less than 0.1%., Conclusion: We developed a simple 10-year risk prediction model for HCC in the Japanese general population as a public education tool., (Copyright © 2012 Elsevier Inc. All rights reserved.)

Ca(2+) microdomains or locally restricted Ca(2+) increases in the cell have recently been reported to regulate many essential physiological events. Ca(2+) increases through the inositol 1,4,5-trisphosphate (IP(3)) receptor (IP(3)R)/Ca(2+) release channels contribute to the formation of a class of such Ca(2+) microdomains, which were often observed and referred to as Ca(2+) puffs in their isolated states. In this report, we visualized IP(3)-evoked Ca(2+) microdomains in histamine-stimulated intact HeLa cells using a total internal reflection fluorescence microscope, and quantitatively characterized the spatial profile by fitting recorded images to a two-dimensional Gaussian distribution. Ca(2+) concentration profiles were marginally spatially anisotropic, with the size increasing linearly even after the amplitude began to decline. We found the event centroid drifted with an apparent diffusion coefficient of 4.20 ± 0.50 μm(2)/s, which is significantly larger than those estimated for IP(3)Rs. The sites of maximal Ca(2+) increase, rather than initiation or termination sites, were detected repeatedly at the same location. These results indicate that Ca(2+) microdomains in intact HeLa cell are generated from spatially distributed multiple IP(3)R clusters or Ca(2+) puff sites, rather than a single IP(3)R cluster reported in cells loaded with Ca(2+) buffers.

Objectives: To investigate whether self-reported hearing loss in older adults is associated with a decline in their ability to perform instrumental activities of daily living (IADL) or a decline in social participation., Design: Prospective follow-up., Setting: Community., Participants: One thousand two hundred fifty-four adults aged 65 to 98., Measurements: Self-reported hearing loss, IADL, and social participation were evaluated through home-visit surveys. Self-reported hearing loss was measured according to responses to the question, "Do you have difficulty hearing and understanding what a person says to you in a quiet room if they speak normally to you, even when wearing your hearing aid?" Levels of IADL and social participation were measured using the subscales of the Tokyo Metropolitan Institute of Gerontology Index of Competence (TMIG-IC)., Results: Of the 921 participants with a perfect baseline IADL score and valid follow-up scores, 105 also self-reported hearing loss at baseline. Of this group, 44.8% (total n = 105) reported a decline in their IADL score over the 3-year follow-up period. After adjusting for major confounders, a statistically significant difference in experiencing an IADL decline over the 3-year period was found between those with hearing loss at baseline and those without (odds ratio (OR) = 1.79, 95% confidence interval (CI) = 1.12-2.87). Self-reported hearing loss at baseline did not have a statistically significant effect on decline in social participation (OR = 1.05, 95% CI = 0.63-1.76) over the 3-year follow-up period., Conclusion: Self-reported hearing loss was associated with a decline in IADL, but not with social participation., (© 2012, Copyright the Authors Journal compilation © 2012, The American Geriatrics Society.)

Iodine is a suspected risk factor for thyroid cancer. Seaweed accounts for about 80% of Japanese people's iodine intake. We examined the association between seaweed consumption and the risk of thyroid cancer in Japanese women. Women participating in the Japan Public Health Center-based Prospective Study (n=52 679; age: 40-69 years) were followed up for a mean of 14.5 years; 134 new thyroid cancer cases, including 113 papillary carcinoma cases, were identified. Seaweed consumption was assessed using a food-frequency questionnaire and divided into three categories: 2 days/week or less (reference); 3-4 days/week; and almost daily. The Cox proportional hazards model was applied to estimate hazard ratios (HRs) and 95% confidence intervals (CIs). Seaweed consumption was clearly associated with an increased risk of papillary carcinoma (HR for almost daily consumption compared with 2 days/week or less=1.71; 95% CI: 1.01-2.90; trend P=0.04). After stratification for menopausal status, an increased risk was observed in postmenopausal women (papillary carcinoma HR for almost daily consumption compared with 2 days/week or less=3.81, 95% CI: 1.67-8.68; trend P<0.01), but not in premenopausal women (HR=0.91, 95% CI: 0.44-1.91; trend P=0.76). This study identified a positive association between seaweed consumption and the risk of thyroid cancer (especially for papillary carcinoma) in postmenopausal women.

The authors propose a CT image segmentation method using structural analysis that is useful for objects with structural dynamic characteristics. Motivation of our research is from the area of genetic activity. In order to reveal the roles of genes, it is necessary to create mutant mice and measure differences among them by scanning their skeletons with an X-ray CT scanner. The CT image needs to be manually segmented into pieces of the bones. It is a very time consuming to manually segment many mutant mouse models in order to reveal the roles of genes. It is desirable to make this segmentation procedure automatic. Although numerous papers in the past have proposed segmentation techniques, no general segmentation method for skeletons of living creatures has been established. Against this background, the authors propose a segmentation method based on the concept of destruction analogy. To realize this concept, structural analysis is performed using the finite element method (FEM), as structurally weak areas can be expected to break under conditions of stress. The contribution of the method is its novelty, as no studies have so far used structural analysis for image segmentation. The method's implementation involves three steps. First, finite elements are created directly from the pixels of a CT image, and then candidates are also selected in areas where segmentation is thought to be appropriate. The second step involves destruction analogy to find a single candidate with high strain chosen as the segmentation target. The boundary conditions for FEM are also set automatically. Then, destruction analogy is implemented by replacing pixels with high strain as background ones, and this process is iterated until object is decomposed into two parts. Here, CT image segmentation is demonstrated using various types of CT imagery.

Objective: To estimate the prevalence and risk factors of dry eye disease (DED) in a rural setting in Japan., Design: Cross-sectional study., Participants: We included 3294 subjects, aged ≥ 40 years who were in the residential registry for Koumi town., Intervention: Subjects in a rural mountain area, Koumi town, completed questionnaires designed to detect dry eye diagnosis and risk factors., Main Outcome Measures: Clinically diagnosed DED was defined as the presence of a previous clinical diagnosis of DED by ophthalmologists or severe symptoms of DED (both dryness and irritation constantly or often). Current symptoms of DED and possible risk factors such as age, gender, educational history, smoking history, alcohol drinking history, height and weight, visual display terminal (VDT) use, and contact lens (CL) wear, and past/current history of certain common systemic diseases were the main outcome measures. We used logistic regression analysis to examine associations between DED and other demographic factors., Results: Of the 3294 eligible residents, 2791 residents (85%) completed the questionnaire. The percentage of women with a composite outcome of clinically diagnosed DED or severe symptoms (21.6%; 95% confidence interval [CI], 19.5-23.9) was higher than that of men (12.5%; 95% CI, 10.7-14.5; P<0.001). A low body mass index (BMI; odds ratio [OR], 2.07; 95% CI, 0.98-4.39), CL use (OR, 3.84; 95% CI, 1.46-10.10), and hypertension (HT) (OR, 1.39; 95% CI, 0.94-2.06) were risk factors for DED in men. Use of a VDT (OR, 2.33; 95% CI, 1.12-4.85), CL use (OR, 3.61; 95% CI, 2.13-6.10), and myocardial infarction or angina were the risk factors (OR, 2.64; 95% CI, 1.51-4.62), whereas high BMI was a preventive factor (OR, 0.69; 95% CI, 0.48-1.01) for DED in women., Conclusions: Among a Japanese cohort, DED leading to a clinical diagnosis or severe symptoms is prevalent. Use of CLs was a common dry eye risk factor in both genders. The condition is more prevalent in men with low BMI, HT, and in women with myocardial infarction or angina and VDT use. Relevant measures directed against the modifiable risks may provide a positive impact on public health and quality of life of Japanese., Financial Disclosure(s): The authors have no proprietary or commercial interest in any materials discussed in this article., (Copyright © 2011 American Academy of Ophthalmology. Published by Elsevier Inc. All rights reserved.)

Genetically encoded Ca(2+) indicators (GECIs) are promising tools for cell type-specific and chronic recording of neuronal activity. In the mammalian central nervous system, however, GECIs have been tested almost exclusively in cortical and hippocampal pyramidal cells, and the usefulness of recently developed GECIs has not been systematically examined in other cell types. Here we expressed the latest series of GECIs, yellow cameleon (YC) 2.60, YC3.60, YC-Nano15, and GCaMP3, in mouse cortical pyramidal cells as well as cerebellar Purkinje cells using in utero injection of recombinant adenoviral vectors. We characterized the performance of the GECIs by simultaneous two-photon imaging and whole-cell patch-clamp recording in acute brain slices at 33 ± 2°C. The fluorescent responses of GECIs to action potentials (APs) evoked by somatic current injection or to synaptic stimulation were examined using rapid dendritic imaging. In cortical pyramidal cells, YC2.60 showed the largest responses to single APs, but its decay kinetics were slower than YC3.60 and GCaMP3, while GCaMP3 showed the largest responses to 20 APs evoked at 20 Hz. In cerebellar Purkinje cells, only YC2.60 and YC-Nano15 could reliably report single complex spikes (CSs), and neither showed signal saturation over the entire stimulus range tested (1-10 CSs at 10 Hz). The expression and response of YC2.60 in Purkinje cells remained detectable and comparable for at least over 100 days. These results provide useful information for selecting an optimal GECI depending on the experimental requirements: in cortical pyramidal cells, YC2.60 is suitable for detecting sparse firing of APs, whereas GCaMP3 is suitable for detecting burst firing of APs; in cerebellar Purkinje cells, YC2.60 as well as YC-Nano15 is suitable for detecting CSs.

The inositol 1,4,5-trisphosphate (IP(3)) receptor (IP(3)R) is an intracellular Ca(2+) release channel, and its opening is controlled by IP(3) and Ca(2+). A single IP(3) binding site and multiple Ca(2+) binding sites exist on single subunits, but the precise nature of the interplay between these two ligands in regulating biphasic dependence of channel activity on cytosolic Ca(2+) is unknown. In this study, we visualized conformational changes in IP(3)R evoked by various concentrations of ligands by using the FRET between two fluorescent proteins fused to the N terminus of individual subunits. IP(3) and Ca(2+) have opposite effects on the FRET signal change, but the combined effect of these ligands is not a simple summative response. The bell-shaped Ca(2+) dependence of FRET efficiency was observed after the subtraction of the component corresponding to the FRET change evoked by Ca(2+) alone from the FRET changes evoked by both ligands together. A mutant IP(3)R containing a single amino acid substitution at K508, which is critical for IP(3) binding, did not exhibit this bell-shaped Ca(2+) dependence of the subtracted FRET efficiency. Mutation at E2100, which is known as a Ca(2+) sensor, resulted in ∼10-fold reduction in the Ca(2+) dependence of the subtracted signal. These results suggest that the subtracted FRET signal reflects IP(3)R activity. We propose a five-state model, which implements a dual-ligand competition response without complex allosteric regulation of Ca(2+) binding affinity, as the mechanism underlying the IP(3)-dependent regulation of the bell-shaped relationship between the IP(3)R activity and cytosolic Ca(2+).

Spinocerebellar ataxia type 15 (SCA15) is a group of human neurodegenerative disorders characterized by a slowly progressing pure cerebellar ataxia. The inositol 1,4,5-trisphosphate (IP(3)) receptor type 1 (IP(3)R1) is an intracellular IP(3)-induced Ca(2+) release channel that was recently identified as a causative gene for SCA15. In most case studies, a heterozygous deletion of the IP(3)R1 gene was identified. However, one Japanese SCA15 family was found to have a Pro to Leu (P1059L) substitution in IP(3)R1. To investigate the effect of the P1059L mutation, we analyzed the channel properties of the mutant human IP(3)R1 by expressing it in an IP(3)R-deficient B lymphocyte cell line. The P1059L mutant was a functional Ca(2+) release channel with a twofold higher IP(3) binding affinity compared to wild-type IP(3)R1. The cooperative dependence of the Ca(2+) release activity of the mutant on IP(3) concentration was reduced, but both wild-type and mutant receptors produced similar B cell receptor-induced Ca(2+) signals. These results demonstrate that the Ca(2+) release properties of IP(3)R1 are largely unaffected by the P1059L mutation., (Copyright © 2011 Elsevier Inc. All rights reserved.)

Background: The anticarcinogenic potential of green tea and coffee might be expected to reduce the risk of thyroid cancer, but epidemiological evidence is sparse. We examined green tea and coffee consumption in association with thyroid cancer risk in a general Japanese population., Methods: We analyzed data from a prospective cohort of 100,507 persons (48,802 men; 51,705 women) aged 40-69. Green tea and coffee consumption were assessed via a self-administered questionnaire. During a mean 14.2-year follow-up, we documented 159 thyroid cancer cases (26 in men; 133 in women), and Cox regression were used to calculated hazard ratios (HRs)., Results: Green tea consumption was not found to be associated with thyroid cancer risk in general. However, when women were stratified by menopausal status, the multivariable HR for ≥ 5 cups/day versus <1 cup/day was 1.66 (95% confidence interval (CI) = 0.85-3.23, trend p = 0.04) in premenopausal women, and was 0.47 (95% CI = 0.23-0.96, trend p = 0.06) in postmenopausal women. We found no association between coffee consumption and thyroid cancer risk in either sex., Conclusions: High green tea consumption may be positively associated with premenopausal thyroid cancer risk, but inversely associated with postmenopausal thyroid cancer risk.

Sarco/endoplasmic reticulum (SR/ER) Ca(2+)-ATPase (SERCA) is an intracellular Ca(2+) pump localized on the SR/ER membrane. The role of SERCA in refilling intracellular Ca(2+) stores is pivotal for maintaining intracellular Ca(2+) homeostasis, and disturbed SERCA activity causes many disease phenotypes, including heart failure, diabetes, cancer, and Alzheimer disease. Although SERCA activity has been described using a simple enzyme activity equation, the dynamics of SERCA activity in living cells is still unknown. To monitor SERCA activity in living cells, we constructed an enhanced CFP (ECFP)- and FlAsH-tagged SERCA2a, designated F-L577, which retains the ATP-dependent Ca(2+) pump activity. The FRET efficiency between ECFP and FlAsH of F-L577 is dependent on the conformational state of the molecule. ER luminal Ca(2+) imaging confirmed that the FRET signal changes directly reflect the Ca(2+) pump activity. Dual imaging of cytosolic Ca(2+) and the FRET signals of F-L577 in intact COS7 cells revealed that SERCA2a activity is coincident with the oscillatory cytosolic Ca(2+) concentration changes evoked by ATP stimulation. The Ca(2+) pump activity of SERCA2a in intact cells can be expressed by the Hill equation with an apparent affinity for Ca(2+) of 0.41 ± 0.0095 μm and a Hill coefficient of 5.7 ± 0.73. These results indicate that in the cellular environment the Ca(2+) dependence of ATPase activation is highly cooperative and that SERCA2a acts as a rapid switch to refill Ca(2+) stores in living cells for shaping the intracellular Ca(2+) dynamics. F-L577 will be useful for future studies on Ca(2+) signaling involving SERCA2a activity.

Studies have associated hearing impairment with adverse health outcomes, but the actual impact of hearing difficulty has been barely investigated. We investigated among older adults (i) the prevalence of hearing difficulty, (ii) the association of hearing difficulty with a composite outcome of dependence in activities of daily living (ADL) and death, and (iii) the population attributable risk fraction (PAF) of hearing difficulty. In 2005, a home-visit survey of 1364 Japanese older adults aged ≥65 (participation proportion=95.5%) was conducted to evaluate self-reports of hearing difficulty. Over 3 years, 99.4% of the initial sample was followed. Outcomes were measured by incidence of death or dependence in ADL. In the sample, the prevalence of hearing difficulty was 17.7% (age ≥65) and 25.7% (age ≥75). Hearing difficulty at high levels was associated with a composite outcome of dependence in ADL and mortality (adjusted odds ratio=OR and 95% confidence interval=95% CI=6.19 (1.92-19.92)) as well as with each outcome independently. Improving the hearing difficulty from high to moderate or no difficulty would reduce the composite outcome in 4.3% (age ≥65) and in 6.3% (age ≥75) of the target population. In conclusion, hearing difficulty was common, was associated with and had substantial impact on adverse health outcomes., (Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.)

Objective: To evaluate exercise intervention efficacy for the prevention and treatment of sarcopenia in the elderly., Methods: We conducted a systematic literature search of randomized controlled trials in the Physical Activity Guidelines Advisory Committee Report (before 2007), Pubmed, the Cochrane database, and Igaku Chuo Zasshi (January 2006 to August 2009)., Data Extraction: Two authors independently extracted relevant data. A total of 951 articles were found by search engines, and 9 studies were finally selected after a review by 2 experts. The content of these studies, especially duration, sets, periods, frequency, and intensity of exercise intervention were extracted and summarized in a results table. Five of 6 articles concluded that high-intensity resistance training significantly increased soft lean tissue and muscle mass. The remaining 3 articles indicated that moderate-intensity resistance training did not affect soft lean tissue or muscle mass., Conclusion: This systematic review suggested that high-intensity resistance training with sufficient periods, frequency, repetitions, and sets is effective to counteract the loss of muscle mass associated with advancing age.

Background: Although knee pain is common in older persons and can cause ambulatory limitation, its impact on self-reliance has rarely been examined in Japan, particularly in a community setting. The aim of this 3-year cohort study was to investigate the association of knee pain with dependence in activities of daily living (ADL) and mortality in community-dwelling older Japanese adults., Methods: In 2005, presence of knee pain was assessed by a home visit survey of 1391 older adults aged 65 years or older (participation proportion = 97.3%). A total of 1265 participants who were ADL-independent at baseline were followed for 3 years, and information on outcomes, namely death and dependence in ADL, was collected., Results: Participants who always had knee pain were more likely to become dependent in ADL than those who reported no knee pain (multivariate-adjusted OR, 1.98; 95% CI, 1.03-3.83); however, always having knee pain was not associated with mortality or a composite outcome of ADL dependence and death. Further analyses of each component of ADL dependence revealed that knee pain was associated with a need for assistance at home (long-term care eligibility, bathing, dressing, and transferring), but not with institutionalization., Conclusions: The participants were highly representative of the target population and the rate of follow-up was almost perfect (99.4%). The results suggest that knee pain is associated with future dependence in ADL, particularly a need for assistance at home.

The N-terminal ∼220-amino acid region of the inositol 1,4,5-trisphosphate (IP(3)) receptor (IP(3)R)/Ca(2+) release channel has been referred to as the suppressor/coupling domain because it is required for both IP(3) binding suppression and IP(3)-induced channel gating. Measurements of IP(3)-induced Ca(2+) fluxes of mutagenized mouse type 1 IP(3)R (IP(3)R1) showed that the residues responsible for IP(3) binding suppression in this domain were not essential for channel opening. On the other hand, a single amino acid substitution of Tyr-167 to alanine completely impaired IP(3)-induced Ca(2+) release without reducing the IP(3) binding activity. The corresponding residue in type 3 IP(3)R (IP(3)R3), Trp-168, was also critical for channel opening. Limited trypsin digestion experiments showed that the trypsin sensitivities of the C-terminal gatekeeper domain differed markedly between the wild-type channel and the Tyr-167 mutant under the optimal conditions for channel opening. These results strongly suggest that the Tyr/Trp residue (Tyr-167 in IP(3)R1 and Trp-168 in IP(3)R3) is critical for the functional coupling between IP(3) binding and channel gating by maintaining the structural integrity of the C-terminal gatekeeper domain at least under activation gating.

The three isoforms of the inositol 1,4,5-trisphosphate receptor (IP(3)R) exhibit distinct IP(3) sensitivities and cooperativities in calcium (Ca(2+)) channel function. The determinants underlying this isoform-specific channel gating mechanism have been localized to the N-terminal suppressor region of IP(3)R. We determined the 1.9 Å crystal structure of the suppressor domain from type 3 IP(3)R (IP(3)R3(SUP), amino acids 1-224) and revealed structural features contributing to isoform-specific functionality of IP(3)R by comparing it with our previously determined structure of the type 1 suppressor domain (IP(3)R1(SUP)). The molecular surface known to associate with the ligand binding domain (amino acids 224-604) showed marked differences between IP(3)R3(SUP) and IP(3)R1(SUP). Our NMR and biochemical studies showed that three spatially clustered residues (Glu-20, Tyr-167, and Ser-217 in IP(3)R1 and Glu-19, Trp-168, and Ser-218 in IP(3)R3) within the N-terminal suppressor domains of IP(3)R1(SUP) and IP(3)R3(SUP) interact directly with their respective C-terminal fragments. Together with the accompanying paper (Yamazaki, H., Chan, J., Ikura, M., Michikawa, T., and Mikoshiba, K. (2010) J. Biol. Chem. 285, 36081-36091), we demonstrate that the single aromatic residue in this region (Tyr-167 in IP(3)R1 and Trp-168 in IP(3)R3) plays a critical role in the coupling between ligand binding and channel gating.

We report ultrasensitive Ca(2+) indicators, yellow cameleon-Nano (YC-Nano), developed by engineering the Ca(2+)-sensing domain of a genetically encoded Ca(2+) indicator, YC2.60 or YC3.60. Their high Ca(2+) affinities (K(d) = 15-140 nM) and large signal change (1,450%) enabled detection of subtle Ca(2+) transients associated with intercellular signaling dynamics and neuronal activity, even in 100,000-cell networks. These indicators will be useful for studying information processing in living multicellular networks.

Asian dust, called 'kosa' in Japan, is the long-range transport of atmospheric pollutants originating from the desert areas of China and Mongolia. Although Asian dust has a long history of appearing in Japan, it is only quite recently that there is increasing concern for its possible adverse health effects. We reviewed the epidemiologic evidence of potential health effects of Asian dust events. PubMed was used to search for the following keywords: Asian dust, yellow sand, desert dust, dust storm, sandstorm, mortality, death, morbidity, hospitalization, hospital admission, health, pulmonary and respiratory. The search was limited to the epidemiologic studies published between January 1980 and May 2009. JMEDPlus was used to search for Japanese literature. Seventeen studies were retrieved from PubMed and one study from JMEDPlus. In addition, one study was identified for reviewing from the references of another study. In total, we identified 19 epidemiologic studies (3 for mortality, 13 for hospital visits or admissions and 3 for respiratory functions or symptoms) mainly from Taiwan and Korea. There were many combinations of outcomes and lagged exposures examined, and some suggested possible associations of dust exposure with an increase in mortality and hospital visits and admissions due to cardiovascular and respiratory diseases, whereas the rest of the studies did not show statistically significant associations. The evidence from these studies was limited because exposure assessments were inadequately described and potential confounders were insufficiently controlled. Well-designed epidemiological studies are required to clarify any potential health effects of Asian dust events in Japan.

Background: Mt. Oyama on Miyakejima Island erupted in June 2000 and all Miyake village citizens were forced to evacuate the island in the September, due to continuous eruptions and emission of unsafe amounts of volcanic gas, mainly sulfur dioxide (SO2). Beginning in February 2005, residents returned to live on the island despite the fact that volcanic gas was still being emitted., Objective: To examine changes in the respiratory systems of included children from February 2006 to November 2006., Methods: The study population was 141 children who participated in health checkups in November 2006, including 33 SO2 hypersusceptible children who had a current or past history of asthma, obstructive lung function, current symptoms of whistling and wheezing, and/or deterioration of respiratory symptoms. Respiratory effects were evaluated by a questionnaire for respiratory symptoms and by spirometry. SO2 was monitored at 7 sampling points within inhabited areas, and the mean SO2 concentration from February 2005 to November 2006 was 0.031 ppm. The area was categorized into four areas by average SO2 concentration, namely, areas L, H-1, H-2, and H-3, where the average SO2 levels were 0.019, 0.026, 0.032, and 0.045 ppm, respectively., Results: Compared to children in area L, the frequencies of "phlegm" and "irritation of the nose" were significantly greater in the children in areas H-2 and H-3. %FVC and %FEV1 in hypersusceptible children were significantly reduced in November 2006 as compared to February 2006 (P = 0.047, 0.027), though no reduction observed in normosusceptible children., Conclusion: Respiratory functions in hypersusceptible Miyakejima children may be affected by SO2 exposure, and further follow-up observation is necessary.

Objectives: To examine the association between hearing handicap and depressive symptoms in older community-dwelling Japanese., Design: Community-based cohort study., Setting: Kurabuchi Town, Gunma Prefecture, Japan., Participants: Five hundred eighty residents (261 men, 319 women) aged 65 and older without depressive symptoms., Measurements: In a baseline examination performed in 2005/06, participants answered the 10-item screening version of the Hearing Handicap Inventory for Elderly (HHIE-S). They were divided into two groups according to their scores: a group with no hearing handicap (HHIE-S scores of < or =8) and a hearing handicap group (HHIE-S scores of > or =10). The Geriatric Depression Scale was used to identify depressive symptoms in face-to-face home visit interviews conducted in 2008, and the association between hearing handicap and depressive symptoms was assessed using logistic regression., Results: The incidence of depressive symptoms was 19.6% in the group with a hearing handicap and 8.0% in the group without a hearing handicap. When compared with the subjects without hearing handicap, subjects with a hearing handicap had a multiadjusted odds ratio of depressive symptoms of 2.45 (95% confidence interval=1.26-4.77). The association remained significant even when hearing impairment measured with pure-tone audiometry was added to the multiadjusted model., Conclusion: A hearing handicap can predict future depressive symptoms in older community-dwelling people.

Background: The prevalence of tinnitus is reported to be high in older Western populations, and several risk factors have been suggested. However, community-based evidence on prevalence is limited and, to our knowledge, there is no such information from older non-Western populations. The purpose of this study was to determine the prevalence and factors associated with tinnitus in community-dwelling Japanese elders., Methods: In this community-based cross-sectional study, 1320 residents of Kurabuchi Town aged 65 years or older (584 men and 736 women; participation proportion = 98.7%) were interviewed at home in 2006, and information on tinnitus and factors associated with tinnitus was collected. We estimated the prevalence of tinnitus by age group and sex and used a logistic regression model to investigate associated factors., Results: The prevalence of tinnitus was 18.6% (men: 18.0%; women: 19.0%); there were no statistically significant differences by age group or sex. Hearing difficulty, depressive mood, prescribed medication, past/current history of coronary heart disease, and knee joint pain requiring medical consultation were associated with tinnitus., Conclusions: These findings suggest that tinnitus is common in Japanese aged over 65 years. Because the factors associated with tinnitus in this cross-sectional study are potentially modifiable, they should be thoroughly investigated in a longitudinal study.

Inositol 1,4,5-trisphosphate (IP(3)) receptors (IP(3)Rs) are IP(3)-gated Ca(2+) release channels localized on intracellular Ca(2+) stores and play a role in the generation of complex patterns of intracellular Ca(2+) signals. We show herein experimental protocols for the identification of associating proteins of IP(3)R isoforms from various cells and tissues using affinity column chromatography and for the specific knockdown of the expression of IP(3)R isoforms and their associating proteins using RNA interference. These methods will provide clues to understand the exact nature of how the signaling complex contributes to the generation of spatio-temporal patterns of intracellular Ca(2+) signals.

Background: Several epidemiological studies have shown that self-reported vision and hearing impairments are associated with adverse health outcomes (AHOs) in older populations; however, few studies have used objective sensory measurements or investigated the role of gender in this association. Therefore, we examined the association of vision and hearing impairments (as measured by objective methods) with AHOs (dependence in activities of daily living or death), and whether this association differed by gender., Methods: From 2005 to 2006, a total of 801 residents (337 men and 464 women) aged 65 years or older of Kurabuchi Town, Gunma, Japan, participated in a baseline examination that included vision and hearing assessments; they were followed up through September 2008. Vision impairment was defined as a corrected visual acuity of worse than 0.5 (logMAR = 0.3) in the better eye, and hearing impairment was defined as a failure to hear a 30 dB hearing level signal at 1 kHz in the better ear. Information on outcomes was obtained from the town hall and through face-to-face home visit interviews. We calculated the risk ratios (RRs) of AHOs for vision and hearing impairments according to gender., Results: During a mean follow-up period of 3 years, 34 men (10.1%) and 52 women (11.3%) had AHOs. In both genders, vision impairment was related to an elevated risk of AHOs (multi-adjusted RR for men and women together = 1.60, 95% CI = 1.05-2.44), with no statistically significant interaction between the genders. In contrast, a significant association between hearing impairment and AHOs (multi-adjusted RR = 3.10, 95% CI = 1.43-6.72) was found only in the men., Conclusion: In this older Japanese population, sensory impairments were clearly associated with AHOs, and the association appeared to vary according to gender. Gender-specific associations between sensory impairments and AHOs warrant further investigation.

Background: The one-leg standing (OLS) test is one of the balance tests used to diagnose musculoskeletal ambulation disability symptom complex (MARS), a condition newly defined by three professional Japanese medical societies in 2006 to help identify the symptoms of motor organ deterioration and establish preventive strategies. Although many studies have used the OLS test, none has shown conclusively that the test can be used as a practical marker of frailty among elderly people, especially in community settings. Based on the type of epidemiological study -- i.e., descriptive epidemiology and analytical epidemiology (observational and intervention studies) -- we reviewed evidence on three fundamental issues related to the OLS test: (1) testing procedures and reference values; (2) the associations between the OLS time and negative events; (3) improvement of the OLS time by intervention. These issues are key to any discussion of whether the OLS test can be used as a practical marker for predicting frailty in community-dwelling elderly populations., Methods: Articles were collected from MEDLINE databases using the search terms "one- leg standing" and the other names included in the same category., Results: Because various procedures are used to carry out the OLS test, the measured values for the OLS time varied widely from study to study. Some observational studies showed that the OLS time is related to negative events such as falls, declines in activity of daily living, and other morbidity. OLS times could be improved by several interventions., Conclusions: This review suggests that the OLS test can be a tool for predicting frailty in community-dwelling elderly populations. However, our review should be interpreted with caution because we did not confirm the evidence level of each of the studies we selected. Further research on this topic is needed.

Salt intake is an important risk factor for hypertension. Because it has been reported that increased salt intake dulls the taste of salt, measuring the sense of taste might be a good way of identifying individuals who consume excessive salt. Using a recently developed simple salt taste test, we investigated the relationship between the taste of salt and blood pressure. The subjects in this cross-sectional study were 823 Japanese adults (479 women and 344 men) 40 years old or older. Following a taste test with salt-impregnated taste strips, the subjects were divided into two groups: normal (recognition threshold of salt at <1.0% concentration) and taste impaired (>or=1.0%). We determined hypertension from the measured blood pressure. In women, the multi-adjusted odds ratio (95% CI) of hypertension in the impaired group was 2.47 (1.53-3.99) compared with the normal group, whereas no significant difference was observed between the two male groups. When we excluded subjects with moderate and severe hypertension, similar findings were observed. A sub-analysis of couples living alone showed a higher prevalence of hypertension among men whose wives were in the impairment group (58.8%) than in the normal group (36.7%, P=0.10). In conclusion, the taste of salt is associated with blood pressure in Japanese women, but not in men. Because most family meals in Japan are prepared by women, educating women about salt reduction may contribute to the prevention of hypertension, not only among women but also among their husbands and family members.-

Background: The number of studies that use objective and quantitative methods to evaluate facial skin aging in elderly people is extremely limited, especially in Japan. Therefore, in this cross-sectional study we attempted to characterize the condition of facial skin (hyperpigmentation, pores, texture, and wrinkling) in Japanese adults aged 65 years or older by using objective and quantitative imaging methods. In addition, we aimed to identify lifestyle factors significantly associated with these visible signs of aging., Methods: The study subjects were 802 community-dwelling Japanese men and women aged at least 65 years and living in the town of Kurabuchi (Takasaki City, Gunma Prefecture, Japan), a mountain community with a population of approximately 4800. The facial skin condition of subjects was assessed quantitatively using a standardized facial imaging system and subsequent computer image analysis. Lifestyle information was collected using a structured questionnaire. The association between skin condition and lifestyle factors was examined using multivariable regression analysis., Results: Among women, the mean values for facial texture, hyperpigmentation, and pores were generally lower than those among age-matched men. There was no significant difference between sexes in the severity of facial wrinkling. Older age was associated with worse skin condition among women only. After adjusting for age, smoking status and topical sun protection were significantly associated with skin condition among both men and women., Conclusions: Our study revealed significant differences between sexes in the severity of hyperpigmentation, texture, and pores, but not wrinkling. Smoking status and topical sun protection were significantly associated with signs of visible skin aging in this study population.

Background: Recent case reports and epidemiological studies suggest that inhalation of indium dust induces lung damage., Objectives: To elucidate the dose-dependent effects of indium on the lungs and to prove a causal relationship more clearly., Methods: A baseline observation was conducted on 465 workers currently exposed to indium, 127 workers formerly exposed to indium and 169 workers without indium exposure in 12 factories and 1 research laboratory from 2003 to 2006. Indium in serum (In-S) was determined as an exposure parameter, and its effects on the lungs were examined., Results: The means of In-S in the current, former and no exposure workers were 8.35, 9.63 and 0.56 ng/ml, respectively. The current and former exposure workers had significantly higher levels of KL-6, and showed significant dose-dependent increases in KL-6, SP-D, and SP-A. Current exposure workers with In-S of 3 ng/ml or above demonstrated a significant increase of KL-6 in both GM and prevalence exceeding the reference value. Approximately a quarter of the former exposure workers had interstitial changes as seen on chest HRCT. In-S of exposed workers who had been working before improvements of the working environment (Group Bef) and those who started working after improvements (Group Aft) were 12.29 and 0.81 ng/ml, respectively. Adjusted odds ratios indicated 87%, 71% and 44% reductions among Group Aft workers who exceeded the reference values of KL-6, SP-D and SP-A, respectively., Conclusion: Dose-dependent lung effects due to indium exposure were shown, and a decrease of indium exposure reduced the lung effects. An In-S value of 3 ng/ml may be a cut-off value which could be used to prevent early effects on the lungs.

Background: Mt. Oyama in Miyakejima Island erupted in June, 2000. All Miyake villagers were forced to evacuate from the island in September, 2000, due to continuous eruptions and emissions of unsafe amounts of volcanic gas, mainly SO2. From February, 2005, Miyake villagers returned to the island despite volcanic gas still being emitted., Objectives: This study examines the 2-yr changes in Miyake residents' respiratory systems from autumn 2004 to November 2006., Methods: The study population was 823 Miyake adult residents who participated in the health check-up in 2006. Respiratory effects were evaluated by a questionnaire for respiratory symptoms and spirometry. SO2 has been continuously monitored at 7 sampling points of the inhabited area. The mean SO2 concentration from February 2005 to November 2006 was 0.031 ppm. The area was categorized into 4 areas by SO2 concentration, namely, areas L, H-1, H-2 and H-3, where average SO2 concentrations were 0.019, 0.026, 0.032, and 0.045 ppm, respectively., Results: The study subjects showed no deterioration in lung function. Prevalence of cough and phlegm among all participants were significantly higher in 2006 than in 2004, and age-, sex- and smoking-adjusted odds ratios of cough and phlegm were 1.75 (95%CI 1.33-2.30) and 1.44 (1.12-1.87). Prevalence of chronic bronchitis-like symptoms among normosusceptive subjects in 2006 was 4.1% which was significantly higher than that of 2.1% in 2004 (p=0.035). Compared to area L, the frequencies of phlegm and irritation of the nose were significantly increased in areas H-2 and H-3., Conclusion: SO2 exposure-related respiratory symptoms were observed in adult Miyakejima residents after returning to the island.

Objectives: To evaluate the association of hearing impairment, vision impairment and their combination (dual sensory impairment) with negative well-being such as depression, subjective poor health and the reduced functional ability in community-dwelling older adults, and to determine whether any association varies by gender., Methods: Between 2005 and 2006, we objectively examined vision and hearing impairment (using best-corrected visual acuity and pure-tone audiometric test) in 843 people aged 65 years and older (351 males, 492 females) in a rural Japanese town. Through a home visit interview survey using a structured questionnaire, we also collected information on depression (the five-item Geriatric Depression Scale), subjective poor health, and reduced functional activity (the Tokyo Metropolitan Institute of Gerontology's Index of Competence)., Results: We observed gender differences in the association between sensory impairment and depression. Multiple logistic regression analysis revealed that hearing impairment in males (adjusted odds ratio: 2.22, 95% confidence interval; 1.07-4.61) and vision impairment in females (1.91, 1.14-3.21) were related to depression. Vision impairment and dual sensory impairment were also associated with subjective poor health and reduced functional activity in both sexes., Conclusions: Sensory impairment is significantly associated with negative well-being in older persons, and its association with depression may differ between males and females.

ATP enhances Ca(2+) release from inositol (1,4,5)-trisphosphate receptors (InsP(3)R). However, the three isoforms of InsP(3)R are reported to respond to ATP with differing sensitivities. Ca(2+) release through InsP(3)R1 is positively regulated at lower ATP concentrations than InsP(3)R3, and InsP(3)R2 has been reported to be insensitive to ATP modulation. We have reexamined these differences by studying the effects of ATP on InsP(3)R2 and InsP(3)R3 expressed in isolation on a null background in DT40 InsP(3)R knockout cells. We report that the Ca(2+)-releasing activity as well as the single channel open probability of InsP(3)R2 was enhanced by ATP, but only at submaximal InsP(3) levels. Further, InsP(3)R2 was more sensitive to ATP modulation than InsP(3)R3 under similar experimental conditions. Mutations in the ATPB sites of InsP(3)R2 and InsP(3)R3 were generated, and the functional consequences of these mutations were tested. Surprisingly, mutation of the ATPB site in InsP(3)R3 had no effect on ATP modulation, suggesting an additional locus for the effects of ATP on this isoform. In contrast, ablation of the ATPB site of InsP(3)R2 eliminated the enhancing effects of ATP. Furthermore, this mutation had profound effects on the patterns of intracellular calcium signals, providing evidence for the physiological significance of ATP binding to InsP(3)R2.

Objective: Studies in Western countries have revealed that urinary incontinence, non-intentional loss of urine, is a common condition in aged populations, and even younger individuals may suffer from urinary incontinence. However, in Japan, the evidence for community residents on this topic is limited. The aim of this study was to estimate the prevalence of urinary incontinence among middle aged using a structured questionnaire and older people and to provide useful information including frequency, voided volume, relation to parity as a risk factor and persons to consult for this condition., Methods: The study subjects consisted of 985 residents, 350 males (mean age 62.5 +/- 11.2 years)and 635 females (64.3 +/- 11.4), who participated in annual health check-ups and answered a self-reported questionnaire on urinary incontinence. The questionnaire included questions on frequency, voided volume, condition-specific QOL score, self-diagnostic item (above four from Scored International Consultation on Incontinence Questionnaire-Short Form Japanese version), person to consult for this condition and parity (only for females)., Results: The proportion of those with urinary incontinence was 11.4% in males and 34.5% in females, and the proportion increased with age (P for trend <0.01). In females, the proportion was high, even in their forties (30.4%). In this study, parity was associated with urinary incontinence: compared to females with no childbirth experience, those giving birth to 4 or more children showed an odds ratio of 4.26 (95% CI: 1.13-16.10). In females, an increase in frequency of urinary incontinence negatively affected the QOL. When asked who they would consult, the majority of males answered either a medical institution (54.2%) or family (34.0%). In females, 39.6% reported a medical institution, 22.6% reported family, 16.5% reported no one, 10.6% reported health nurses other than in medical institutions and 9.5% reported friends., Conclusions: The study results showed that urinary incontinence is a common condition in this population. Particularly, a large proportion of females suffer from this condition, even in their forties. The study also revealed that urinary incontinence might negatively affect the QOL and that there are some individuals who do not consult (or intend to consult) anyone about their problem. This information might be useful for planning health policy on the topic in the future.

Objectives: This study evaluated the association between job strain and subclinical indicators of arteriosclerosis simultaneously in the cerebral artery, the aorta, and the carotid artery., Methods: The participants in this cross-sectional study consisted of 352 male factory workers between the ages of 24.9 to 55.8 (mean 41.7) years who had not been exposed to any hazardous chemicals in Japan. Job strain was measured using a Japanese version of the Job Content Questionnaire developed by Karasek. The following subclinical indicators of arteriosclerosis were examined by noninvasive procedures: hyperintense spots in T2-weighted images in brain magnetic resonance imaging (MRI), pulse wave velocity of the aorta, and the stiffness parameter of the carotid artery using ultrasound and systolic and diastolic blood pressure., Results: After control for potential confounders, high job strain was associated with an increased prevalence of hyperintense spots (adjusted odds ratio 2.53, 95% confidence interval 1.14-5.63), and elevated pulse-wave velocity (adjusted increase in percent 3.5, 95% confidence interval 0.0-6.9). The stiffness parameter tended to be elevated in the high job-strain group although this trend was not statistically significant. Job strain showed no relation to blood pressure., Conclusions: In this study, job strain was associated with subclinical indicators of arteriosclerosis in different arteries although the association was not statistically significant for the carotid artery. New information is offered by brain MRI for arteriosclerosis in the cerebral artery. An increase in hyperintense spots may explain the link between job strain and cerebrovascular disease.

Introduction: The aim of this study was to assess the efficacies of early orchidopexy on later morphological changes in the testis using ultrasonography., Materials and Methods: The medical records of 23 consecutive patients with unilateral undescended testis operated on in our institution between 1992 and 2001 were reviewed in the historical cohort design. The subjects were divided into two groups according to their age at the time of surgery: group A included the patients who underwent surgery before age 2 (n = 13), and group B included those who were operated on at 2 years of age or older (n = 10). The mean undescended testicular volume and the incidence risk of morphological abnormalities detected by ultrasonography were compared between the two groups., Results: At 5 years after orchidopexy, the difference in the mean volume between the two groups was not statistically significant. The incidence risk of structural abnormalities at 5 years after orchidopexy was lower in group A than in group B (25.0 vs. 83.3%, p = 0.05)., Conclusions: This study thus provides evidence that orchidopexy at a younger age could prevent morphological changes in the undescended testis., ((c) 2008 S. Karger AG, Basel.)

Cytoplasmic Ca2+ signals are highly regulated by various ion transporters, including the inositol 1,4,5-trisphosphate (IP(3)) receptor (IP(3)R), which functions as a Ca2+ release channel on the endoplasmic reticulum membrane. Crystal structures of the two N-terminal regulatory regions from type 1 IP(3)R have been reported; those of the IP(3)-binding core (IP(3)R(CORE)) with bound IP(3), and the suppressor domain. This study examines the structural effects of ligand binding on an IP(3)R construct, designated IP(3)R(N), that contains both the IP(3)-binding core and the suppressor domain. Our circular dichroism results reveal that the IP(3)-bound and IP(3)-free states have similar secondary structure content, consistent with preservation of the overall fold within the individual domains. Thermal denaturation data show that, while IP(3) has a large effect on the stability of IP(3)R(CORE), it has little effect on IP(3)R(N), indicating that the suppressor domain is critical to the stability of IP(3)R(N). The NMR data for IP(3)R(N) provide evidence for chemical exchange, which may be due to protein conformational dynamics in both apo and IP(3)-bound states: a conclusion supported by the small-angle X-ray scattering data. Further, the scattering data show that IP(3)R(N) undergoes a change in average conformation in response to IP(3) binding and the presence of Ca2+ in the solution. Taken together, these data lead us to propose that there are two flexible linkers in the N-terminal region of IP(3)R that join stably folded domains and give rise to an equilibrium mixture of conformational sub-states containing compact and more extended structures. IP(3) binding drives the conformational equilibrium toward more compact structures, while the presence of Ca2+ drives it to a more extended set.

Three isoforms of the inositol 1,4,5-trisphosphate (IP(3)) receptor (IP(3)R), IP(3)R1, IP(3)R2, and IP(3)R3, have different IP(3)-binding affinities and cooperativities. Here we report that the amino-terminal 604 residues of three mouse IP(3)R types exhibited K(d) values of 49.5 +/- 10.5, 14.0 +/- 3.5, and 163.0 +/- 44.4 nm, which are close to the intrinsic IP(3)-binding affinity previously estimated from the analysis of full-length IP(3)Rs. In contrast, residues 224-604 of IP(3)R1 and IP(3)R2 and residues 225-604 of IP(3)R3, which contain the IP(3)-binding core domain but not the suppressor domain, displayed an almost identical IP(3)-binding affinity with a K(d) value of approximately 2 nm. Addition of 100-fold excess of the suppressor domain did not alter the IP(3)-binding affinity of the IP(3)-binding core domain. Artificial chimeric proteins in which the suppressor domain was fused to the IP(3)-binding core domain from different isoforms exhibited IP(3)-binding affinity significantly different from those of the proteins composed of the native combination of the suppressor domain and the IP(3)-binding core domain. Systematic mutagenesis analyses showed that amino acid residues critical for type-3 receptor-specific IP(3)-binding affinity are involved in Glu-39, Ala-41, Asp-46, Met-127, Ala-154, Thr-155, Leu-162, Trp-168, Asn-173, Asn-176, and Val-179. These results indicate that the IP(3)-binding affinity of IP(3)Rs is specifically tuned through the intramolecular attenuation of IP(3)-binding affinity of the IP(3)-binding core domain by the amino-terminal suppressor domain. Moreover, the functional diversity in ligand sensitivity among IP(3)R isoforms originates from at least the structural difference identified on the suppressor domain.

The inositol 1,4,5-trisphosphate (IP3) receptors (IP3Rs) are IP3-gated intracellular Ca2+ channels. We previously identified an IP3R binding protein, IRBIT, which binds to the IP3 binding domain of IP3R and is dissociated from IP3R in the presence of IP3. In the present study, we showed that IRBIT suppresses the activation of IP3R by competing with IP3 by [3H]IP3 binding assays, in vitro Ca2+ release assays, and Ca2+ imaging of intact cells. Multiserine phosphorylation of IRBIT was essential for the binding, and 10 of the 12 key amino acids in IP3R for IP3 recognition participated in binding to IRBIT. We propose a unique mode of IP3R regulation in which IP3 sensitivity is regulated by IRBIT acting as an endogenous "pseudoligand" whose inhibitory activity can be modulated by its phosphorylation status.

We developed genetically encoded fluorescent inositol 1,4,5-trisphosphate (IP3) sensors that do not severely interfere with intracellular Ca2+ dynamics and used them to monitor the spatiotemporal dynamics of both cytosolic IP3 and Ca2+ in single HeLa cells after stimulation of exogenously expressed metabotropic glutamate receptor 5a or endogenous histamine receptors. IP3 started to increase at a relatively constant rate before the pacemaker Ca2+ rise, and the subsequent abrupt Ca2+ rise was not accompanied by any acceleration in the rate of increase in IP3. Cytosolic [IP3] did not return to its basal level during the intervals between Ca2+ spikes, and IP3 gradually accumulated in the cytosol with a little or no fluctuations during cytosolic Ca2+ oscillations. These results indicate that the Ca2+ -induced regenerative IP3 production is not a driving force of the upstroke of Ca2+ spikes and that the apparent IP3 sensitivity for Ca2+ spike generation progressively decreases during Ca2+ oscillations.

We isolated cDNAs encoding type 2 and type 3 inositol 1,4,5-trisphosphate (IP(3)) receptors (IP(3)R2 and IP(3)R3, respectively) from mouse lung and found a novel alternative splicing segment, SI(m2), at 176-208 of IP(3)R2. The long form (IP(3)R2 SI(m2)(+)) was dominant, but the short form (IP(3)R2 SI(m2)(-)) was detected in all tissues examined. IP(3)R2 SI(m2)(-) has neither IP(3) binding activity nor Ca(2+) releasing activity. In addition to its reticular distribution, IP(3)R2 SI(m2)(+) is present in the form of clusters in the endoplasmic reticulum of resting COS-7 cells, and after ATP or Ca(2+) ionophore stimulation, most of the IP(3)R2 SI(m2)(+) is in clusters. IP(3)R3 is localized uniformly on the endoplasmic reticulum of resting cells and forms clusters after ATP or Ca(2+) ionophore stimulation. IP(3)R2 SI(m2)(-) does not form clusters in either resting or stimulated cells. IP(3) binding-deficient site-directed mutants of IP(3)R2 SI(m2)(+) and IP(3)R3 fail to form clusters, indicating that IP(3) binding is involved in the cluster formation by these isoforms. Coexpression of IP(3)R2 SI(m2)(-) prevents stimulus-induced IP(3)R clustering, suggesting that IP(3)R2 SI(m2)(-) functions as a negative coordinator of stimulus-induced IP(3)R clustering. Expression of IP(3)R2 SI(m2)(-) in CHO-K1 cells significantly reduced ATP-induced Ca(2+) entry, but not Ca(2+) release, suggesting that the novel splice variant of IP(3)R2 specifically influences the dynamics of the sustained phase of Ca(2+) signals.

The inositol 1,4,5-trisphosphate (IP(3)) receptor (IP(3)R) Ca(2+) channel plays pivotal roles in many aspects of physiological and pathological events. It was previously reported that IP(3)R forms clusters on the endoplasmic reticulum when cytosolic Ca(2+) concentration ([Ca(2+)](C)) is elevated. However, the molecular mechanism of IP(3)R clustering remains largely unknown, and thus its physiological significance is far from clear. In this study we found that the time course of clustering of green fluorescent protein-tagged IP(3)R type 1 (GFP-IP(3)R1), evoked by IP(3)-generating agonists, did not correlate with [Ca(2+)](C) but seemed compatible with cytoplasmic IP(3) concentration. IP(3) production alone induced GFP-IP(3)R1 clustering in the absence of a significant increase in [Ca(2+)](C) but elevated [Ca(2+)](C) without IP(3) production did not. Moreover IP(3)R1 mutants that do not undergo an IP(3)-induced conformational change failed to form clusters. Thus, IP(3)R clustering is induced by its IP(3)-induced conformational change to the open state. We also found that GFP-IP(3)R1 clusters colocalized with ERp44, a luminal protein of endoplasmic reticulum that inhibits its channel activity. This is the first example of ligand-induced clustering of a ligand-gated channel protein.