Eukaryotic chromosome DNA replication: where, when, and how?

DNA replication is central to cell proliferation. Studies in the past six decades since the proposal of a semiconservative mode of DNA replication have confirmed the high degree of conservation of the basic machinery of DNA replication from prokaryotes to eukaryotes. However, the need for replication of a substantially longer segment of DNA in coordination with various internal and external signals in eukaryotic cells has led to more complex and versatile regulatory strategies. The replication program in higher eukaryotes is under a dynamic and plastic regulation within a single cell, or within the cell population, or during development. We review here various regulatory mechanisms that control the replication program in eukaryotes and discuss future directions in this dynamic field.

Sex steroid hormones and allergic diseases in children: a pilot birth cohort study in the Japan Environment and Children's Study cohort.

BACKGROUND: Numerous studies suggest that sex steroids might play a role in sex disparity observed in allergic diseases in adults. However, whether sex hormones influence allergic diseases in children remains unclear. The aim of the present study was to examine the association of sex steroid hormones with allergic disease in Japanese children. METHODS: The present cross-sectional study included 145 6-year-old children participating in a pilot birth cohort study in the Japan Environment and Children's Study. Data on allergic diseases were obtained from questionnaires, and serum levels of sex steroid hormones and allergen-specific IgE were measured. Logistic regression was performed to evaluate the association of sex hormones with allergic diseases. RESULTS: After adjusted sex, amount of body fat at 6 years, parental history of allergic disease, and exposure to tobacco smoke, serum dehydroepiandrosterone sulfate level was significantly associated with reduced odds of any allergic disease (adjusted odds ratio, 0.58; 95% confidence interval, 0.36-0.93; P = 0.024) and serum follicle-stimulating hormone level was significantly associated with increased odds of any allergic disease (adjusted odds ratio, 2.04; 95% confidence interval, 1.01-4.11, P = 0.046). Dehydroepiandrosterone sulfate level showed a significant association with number of allergic diseases. CONCLUSIONS: The current study findings suggest that sex hormones may play an important role in the development of allergic diseases in prepubertal children.

Fluctuations of aeroallergen-specific immunoglobulins and children's allergic profiles: Japan Environment & Children's Study of a pilot cohort.

BACKGROUND: Allergen-specific immunoglobulins have a crucial role in allergic diseases. Most wheeze episodes develop before school age, and allergic rhinitis later develops during early elementary school years. However, the clinical background and cytokine/chemokine profiles associated with changes in immunoglobulins during early school-age are poorly understood. METHODS: This study used blood samples from children participating in the JECS Pilot Study. We examined nineteen kinds of aeroallergen-specific immunoglobulins (IgE, IgG1, IgG4, and IgA) levels in patients at age 6 and age 8. Fluctuations of Der f 1- and Cry j 1-specific immunoglobulins levels during the two periods were compared to assess the frequency of allergic statuses and clusters of cytokine/chemokine profiles. RESULTS: The medians of aeroallergen-specific IgE levels did not fluctuate, and almost all IgG1 and IgG4 decreased. In IgA, four (e.g., Der f 1) increased, whereas the other four (e.g., Cry j 1) decreased. The ratio of the Der f 1-specific IgG1 level at age 8 to that at age 6 was higher in children with poor asthma control than in children with better asthma control. Moreover, the cytokine/chemokine cluster with relatively lower IL-33 and higher CXCL7/NAP2 was associated with lower Der f 1- and Cry j 1-specific IgG4 levels, but not IgE levels. CONCLUSIONS: The cluster of cytokine/chemokine profiles characterized by lower IL-33 and higher CXCL7/NAP2 was associated with the maintenance of aeroallergen-specific IgG4 levels. This result provides a basis for considering the control of aeroallergen-specific immunoglobulins.

Downregulated expression of intestinal P-glycoprotein in rats with cisplatin-induced acute kidney injury causes amplification of its transport capacity to maintain "gatekeeper" function.

The expression of transporters on the apical and basal membranes of renal proximal tubular cells are down- or upregulated to various extents under cisplatin (CDDP)-induced acute kidney injury (AKI). However, little is known about the changes in transporters in tissues other than the kidney under CDDP-induced AKI. This study aimed to investigate the modulation of the expression/function of intestinal efflux transporters, P-glycoprotein (P-gp) and breast cancer resistance protein (Bcrp), in CDDP-induced AKI rats. On day 3 after the intraperitoneal administration of CDDP (5 mg/kg) to rats, the expression levels of P-gp and Bcrp were compared with those of normal rats. Further, the absorption of three P-gp substrates (6α-methylprednisolone, rhodamine 123, and gatifloxacin) was evaluated in both groups using conventional loop techniques. In the CDDP-induced AKI rats, P-gp expression in the ileum was markedly decreased to approximately 38% of that in the normal rats. However, no significant changes in Bcrp expression were observed in the AKI rats. In contrast with the reduction in P-gp expression in the AKI rats, the absorption of the three P-gp substrates remained almost the same or decreased in the AKI group. The addition of verapamil (a potent P-gp inhibitor) increased the absorption of the three P-gp substrates to the values obtained from the normal rats. In conclusion, our results suggested that P-gp expression is downregulated in rats with CDDP-induced AKI but that P-gp maintains its potency as a "gatekeeper" against the absorption of xenobiotics by amplifying its individual transport capacity under these conditions.

Exploratory analysis of plasma cytokine/chemokine levels in 6-year-old children from a birth cohort study.

This study aimed to reveal a new dimension of allergy profiles in the general population by using machine learning to explore complex relationships among various cytokines/chemokines and allergic diseases (asthma and atopic dermatitis; AD). We examined the symptoms related to asthma and AD and the plasma levels of 72 cytokines/chemokines obtained from a general population of 161 children at 6 years of age who participated in a pilot birth cohort study of the Japan Environment and Children's Study (JECS). The children whose signs and symptoms fulfilled the criteria of AD, which are mostly based on questionnaire including past symptoms, tended to have higher levels of the two chemokine ligands, CCL17 and CCL27, which are used for diagnosis of AD. On the other hand, another AD-related chemokine CCL22 level in plasma was higher only in children with visible flexural eczema, which is one of AD diagnostic criteria but was judged on the same day of blood examination unlike other criteria. Here, we also developed an innovative method of machine learning for elucidating the complex cytokine/chemokine milieu related to symptoms of allergic diseases by using clustering analysis based on the random forest dissimilarity measure that relies on artificial intelligence (AI) technique. To our surprise, the majority of children showing at least any asthma-related symptoms during the last month were divided by AI into the two clusters, either cluster-2 having elevated levels of IL-33 (related to eosinophil activation) or cluster-3 having elevated levels of CXCL7/NAP2 (related to neutrophil activation), among the total three clusters. Future studies will clarify better approach for allergic diseases by endotype classification.

Psychometric profile of the Ages and Stages Questionnaires, Japanese translation.

BACKGROUND: This study assessed the psychometric profile of 10 questionnaires (every 6 months, from 6 to 60 months) from the Japanese translation of the Ages and Stages Questionnaires, third edition (J-ASQ-3). METHODS: Data from 439 children in a birth cohort were used to identify the J-ASQ-3 score distribution, establish cut-off scores, and calculate the instrument's internal consistency. Data were also collected from 491 outpatients to examine J-ASQ-3 test-retest reliability and concurrent validity, which was examined using the Kyoto Scale of Psychological Development (KSPD) and the Japanese version of the Denver Developmental Screening Test II (J-Denver II). Both the original and the alternative screening criteria of the ASQ-3 were used (failure in at least one and at least two domains, respectively). RESULTS: Cronbach's alpha for each J-ASQ-3 subscale on each questionnaire ranged from 0.45 to 0.89. Test-retest reliability was >0.75 for the subscales on almost all questionnaires. Concurrent validity was also adequate. In comparison with the screening results of the KSPD, the overall sensitivity and specificity were 96.0% and 48.8%, respectively, when the ASQ-3 original criterion was used, and 92.1% and 74.9%, respectively, when the alternative criterion was used. In comparison with the screening results of the J-Denver II, the overall sensitivity and specificity were 75.6% and 74.7%, respectively, when the ASQ-3 original criterion was used, and 56.3% and 93.0%, respectively, when the alternative criterion was used. CONCLUSIONS: This study quantified the psychometric profiles of the Japanese translations of 10 ASQ-3 questionnaires. We demonstrated the validity of the J-ASQ-3 and determined new cut-off scores. Further studies with larger samples from a greater range of locations are required to clarify the suitability of this tool for all Japanese children.

Factors associated with occupation changes after pregnancy/delivery: result from Japan Environment & Children's pilot study.

BACKGROUND: In Japan, although the number of females who continue to work after marriage has recently increased, the proportion of those working while parenting their infants is still not clearly increasing, indicating that it is still difficult for them to continue working after delivery. The present study aimed to clarify factors influencing females' continuation of work, using data obtained by continuously following up the same subjects and focusing on occupation changes, family environments, and the type of employment after pregnancy or delivery. METHODS: Based on the results of the questionnaire survey, which was conducted involving 164 participants at 4 universities, as part of the Japan Environment and Children's Pilot Study (JECS Pilot Study) led by the Ministry of Environment and the National Institute for Environmental Studies, the occupational status was compared between the detection of pregnancy (weeks 0 to 7) and 1 year after delivery. RESULTS: compared with changed their occupations significantly more frequently (OR = 5.07, 95% CI = 2.57-10.01, P < 0.001). Furthermore, on examining in detail, occupation changes were particularly marked among (OR = 12.48, 95% CI = 4.43-35.15, P < 0.001). This tendency was especially shown among < > (OR = 10.36, 95% CI = 1.59-67.38, P = 0.014) and < > (OR = 15.15, 95% CI = 2.55-90.17, P = 0.003). CONCLUSIONS: Analysis revealed that the type of employment, rather than the category of occupation, was associated with the continuation of work after pregnancy or delivery more closely, as compared with continued to work less frequently. Furthermore, on comparison of the category of occupation among , < > and < > were shown to be more likely to continue to be engaged in the same occupation after pregnancy or delivery. These differences may be related to availability of the child-care leave program and other support resources, therefore, it may be important to establish social systems that enable all females, to use these support resources if they wish, and actively work, while delivering and parenting their children.

Regional differences in infant 25-Hydroxyvitamin D: Pilot study of the Japan Environment and Children's Study.

BACKGROUND: In recent years, a resurgence in the number of infants with vitamin D deficiency has been noted. In addition to seasonal differences in exposure to ultraviolet (UV) rays, regional differences in dietary habits and lifestyles may affect susceptibility to vitamin D deficiency. No studies have been conducted, however, on infants in multiple regions of Japan to determine the extent of differences in vitamin D status. METHODS: 25-Hydroxyvitamin D (25OHD) was measured on radioimmunoassay in 126 infants aged 2-4 years, who participated in the Pilot Study of the Japan Environment and Children's Study (JECS) by the Ministry of Environment of Japan. A multiple regression model with 25OHD level as the outcome variable, and season and region as explanatory variables, was generated. RESULTS: Both region and season during which infants participated in this study significantly affected 25OHD level (P = 0.0087 and <0.0001, respectively; Wald test). Reflecting decreased exposure to UV rays, infants who were examined in winter had lower 25OHD than those examined in summer. Infants from both Fukuoka Prefecture (33°N) and Kumamoto Prefecture (32°N), however, had lower 25OHD than those from Tochigi Prefecture (36°N), contrary to expectations given the extent of UV exposure. CONCLUSIONS: Regional differences in daily habits and/or environmental factors affect 25OHD level in Japanese infants. The JECS is expected to identify those factors to provide guidance on preventing infantile vitamin D deficiency.

Investigation on the Interactions between Various Drugs and Aojiru (Green Juice) Using a Simple Centrifugation Method.

The objective of this study was to evaluate the interactions between various drugs and aojiru (green juice), a popular health food in Japan, using a simple centrifugation method. The mixture of drug solution and aojiru suspension was gently shaken and centrifuged. The drug concentration in the supernatant fluid was then determined by HPLC. The concentration of rhodamine 123 (Rho-123), a model compound, in the supernatant fluid significantly decreased after mixing with aojiru, indicating extensive binding of Rho-123 to the insoluble components of aojiru. When administered into rat small intestinal loops together with aojiru, the plasma Rho-123 concentrations became much smaller than those when administered alone. This result strongly suggested that a strong interaction observed in vitro was well reflected in modulated absorption. Among seven drugs tested, chlorpromazine and imipramine exerted binding properties to aojiru similar to or greater than Rho-123. As a small part of both Rho-123 and imipramine was released when the aojiru precipitate was resuspended, their binding to aojiru was considered to be tight. The binding of diltiazem, fexofenadine, glibenclamide, metformin, and norfloxacin to aojiru was much weaker or almost negligible compared with that of chlorpromazine and imipramine. The present results suggest that aojiru can decrease the intestinal absorption of some clinically relevant drugs through tight binding in the small intestine and that the present centrifugation method is useful for predicting in vivo interactions between drugs and aojiru.

Association of excessive mobile phone use during pregnancy with birth weight: an adjunct study in Kumamoto of Japan Environment and Children's Study.

BACKGROUND: Low birth weight has been shown to be closely associated with neonatal mortality and morbidity, inhibited growth, poor cognitive development, and chronic diseases later in life. Some studies have also shown that excessive mobile phone use in the postnatal period may lead to behavioral complications in the children during their growing years; however, the relationship between mobile phone use during pregnancy and neonatal birth weight is not clear. The aim of the present study was to determine the associations of excessive mobile phone use with neonatal birth weight and infant health status. METHODS: A sample of 461 mother and child pairs participated in a survey on maternal characteristics, infant characteristics, and maternal mobile phone usage information during pregnancy. RESULTS: Our results showed that pregnant women tend to excessively use mobile phones in Japan. The mean infant birth weight was lower in the excessive use group than in the ordinary use group, and the frequency of infant emergency transport was significantly higher in the excessive use group than in the ordinary use group. CONCLUSIONS: Excessive mobile phone use during pregnancy may be a risk factor for lower birth weight and a high rate of infant emergency transport.

Rif1 regulates the replication timing domains on the human genome.

DNA replication is spatially and temporally regulated during S-phase. DNA replication timing is established in early-G1-phase at a point referred to as timing decision point. However, how the genome-wide replication timing domains are established is unknown. Here, we show that Rif1 (Rap1-interacting-factor-1), originally identified as a telomere-binding factor in yeast, is a critical determinant of the replication timing programme in human cells. Depletion of Rif1 results in specific loss of mid-S replication foci profiles, stimulation of initiation events in early-S-phase and changes in long-range replication timing domain structures. Analyses of replication timing show replication of sequences normally replicating early is delayed, whereas that normally replicating late is advanced, suggesting that replication timing regulation is abrogated in the absence of Rif1. Rif1 tightly binds to nuclear-insoluble structures at late-M-to-early-G1 and regulates chromatin-loop sizes. Furthermore, Rif1 colocalizes specifically with the mid-S replication foci. Thus, Rif1 establishes the mid-S replication domains that are restrained from being activated at early-S-phase. Our results indicate that Rif1 plays crucial roles in determining the replication timing domain structures in human cells through regulating higher-order chromatin architecture.

Relieving pain and distress during venipuncture: Pilot study of the Japan Environment and Children's Study (JECS).

Pain management for needle-related procedures is poor in Japan. In many countries the use of lidocaine/prilocaine cream for the relief of pain associated with venipuncture has been approved. In children, a psychological approach has also been shown to be effective in reducing pain with venipuncture. We developed a multidisciplinary procedure that combines a cream (2.5% lidocaine and 2.5% prilocaine) and pharmacological approaches such as preparation, education, positioning and distraction. We evaluated the feasibility and acceptability of the procedure for young children. Among 132 pediatric participants, 58.3% did not cry during venipuncture. According to caregiver questionnaire, 71.9% felt that the multidisciplinary procedure eliminated the fear of needle-related procedures in the children; 90.9% were satisfied with it and 75.8% thought it should be applied to all children undergoing venipuncture. The present results suggest that the multidisciplinary procedure is feasible, acceptable and suitable for use in children undergoing venipuncture.

Prevalence and interannual changes in multiple chemical sensitivity in Japanese workers.

OBJECTIVE: We aimed to evaluate the prevalence rates and interannual fluctuations in multiple chemical sensitivity (MCS) in Japanese workers. METHODS: We assessed MCS using the Quick Environmental Exposure and Sensitivity Inventory, employing both Miller and Japanese criteria. Workers of two manufacturing companies located in Kyushu, Japan, were assessed, with company A surveyed in 2003, 2006 and 2011, and company B in 2003 and 2011. RESULTS: In company A, the Miller criteria-based MCS prevalence rate was higher in 2011 than in 2003, and according to the Japanese criteria, it was higher in 2011 than 2006. In company B, the Miller criteria-based MCS prevalence rate was lower in 2011 than in 2003. CONCLUSION: The results indicated that MCS exists among industrial workers in Japan. We found no statistically significant interannual changes in MCS rates.

Preferential meropenem absorption activated by 1α,25-dihydroxyvitamin D3 and shared with foscarnet, a phosphate transporter substrate, in the rat ileum.

Meropenem (MEPM) is used for the treatment of serious infectious diseases solely as. INJECTABLE: Therefore, the development of an oral formulation would expand its clinical utility. To this end, an exact understanding of the absorption characteristics of MEPM is essential. In this study, MEPM absorption in the rat small intestine was investigated using an in situ loop technique and an in vitro diffusion chamber method. The disappearance ratios of MEPM (0.1 mM) were in the order of ileum > duodenum > jejunum. The extensive MEPM disappearance in the ileum was significantly reduced in the presence of foscarnet, a Na+-dependent phosphate transporter (NaPi-T) substrate, whereas glycylsarcosine, thiamine, taurocholic acid, and biapenem had no effects. The mucosal-to-serosal (M-to-S) permeation of MEPM across the rat ileal segments was very small under normal experimental conditions. However, on addition of 1α,25-dihydroxyvitamin D3 (1,25(OH)2D3) to the experimental medium, the M-to-S permeation of MEPM markedly increased, showing a more than 7-fold greater apparent permeation coefficient. The present results suggest that MEPM is preferentially absorbed in the rat ileum, sharing with foscarnet, and that 1,25(OH)2D3 potentially activates the absorption of MEPM there. A likely candidate for involvement in MEPM absorption was NaPi-T or a related transporter.

Association between antinuclear antibody positivity and chemical exposure among pregnant Japanese women: A cross-sectional study based on the Japan environment and Children's study.

Antinuclear antibodies (ANAs) are detected in healthy individuals, they are more prevalent in women than in men. Pregnant women are immunologically unique, but epidemiological data on ANA positivity in them remain limited. The exposure received from the mother during the fetal period impacts the future health of the fetus and has thus received increased attention in recent years. Thus, we investigated the association between ANA positivity and chemical exposure among pregnant Japanese women, registered in the Japan Environment and Children's Study (JECS). ANA titers were assessed by indirect immunofluorescence with HEp-2 cells at a cutoff dilution of 1:40. Sociodemographic and other data were obtained in the JECS from a self-administered questionnaire. We analyzed 1,235 Japanese women in their first trimester of pregnancy. The ANA prevalence was 17.2%. Among ANA-positive women, a speckled pattern was the most common (95.3%), followed by a homogeneous pattern (72.3%). Exposure to chemicals more than once a week significantly increased the probability of ANA positivity (kerosene, petroleum, benzene, or gasoline: adjusted odds ratio [AOR], 2.11; 95% confidence interval [95% CI], 1.03-4.34; chlorine bleach or germicide: AOR, 1.97; 95% CI, 1.10-3.54; organic solvents: AOR, 5.34; 95% CI, 1.40-20.36; and photocopying machines or laser printers: AOR, 1.73; 95% CI, 1.17-2.54). ANA positivity was associated with exposure to several chemicals in Japanese women. Our exploratory results suggested that ANAs as potential markers of chemical exposure warrant further research.

Relationship between the Mediterranean Diet Score in Pregnancy and the Incidence of Asthma at 4 Years of Age: The Japan Environment and Children's Study.

Several scoring methods for the Mediterranean diet, which is considered as a healthy diet, are available, but studies that have compared more than one of these scores are rare. In addition, the applicability of Mediterranean diet scoring has not been sufficiently examined outside of Mediterranean regions. We collected data on the Mediterranean diet during pregnancy and the incidence of type 1 allergies in offspring from the Japan Environment and Children's Study. Using multiple Mediterranean diet scoring methods, we analyzed the effect of adherence to the Mediterranean diet in pregnancy on the allergies of the offspring. Overall, 46,532 pairs of mothers and children were analyzed. In Japan, a high adherence to the Mediterranean diet during pregnancy was associated with a lower incidence of asthma in the offspring (odds ratio: 0.896, 95% confidence interval: 0.835, 0.962). Furthermore, we found that the selection of the Mediterranean diet scoring method and the setting of the reference value significantly altered the results. Our findings suggest that an appropriate selection of scoring methods and a reference value for food items are important to analyze the effects of adherence to the Mediterranean diet inside and outside of Mediterranean regions.

Impaired Height Growth Associated with Vitamin D Deficiency in Young Children from the Japan Environment and Children's Study.

Vitamin D is essential for calcium absorption and bone homeostasis. Although short-stature children were reported to have low vitamin D concentrations, there is no clear evidence of a link between vitamin D and height growth in young children not limited to those with short stature. We collected height and weight data at 2 and 4 years of age, serum vitamin D concentrations at 4 years, and questionnaire results on sun exposure from the Japan Environment and Children's Study (JECS). We then analyzed the relationship between vitamin D deficiency and height growth. We also analyzed the correlation between serum vitamin D concentration and sun exposure. Overall, 3624 participants from JECS were analyzed. We identified cases of subclinical vitamin D deficiency and insufficiency. We further found that definitive vitamin D deficiency (<10 ng/mL) impaired height growth by 0.6 cm per year even in young children not limited to those with short stature. Furthermore, we clarified that children with vitamin D deficiency had reduced outdoor activity, especially during winter. In children with either short or normal stature, definitive vitamin D deficiency was associated with height growth decline, and reduction in outdoor activity, especially during winter, was a risk factor for vitamin D deficiency.

[Investigation of Leftover Hyperphosphatemia Drugs in Hemodialysis Outpatients].

Currently, various hyperphosphatemia drugs are administered orally to hemodialysis patients in order to lower serum phosphorus levels. However, it is known that medication adherence is poor, possibly due to greater pill burden taken each time and their complicated schedules. Therefore, large amounts of unused hyperphosphatemia drugs are likely to be leftover. The increase in leftover prescribed drugs leads to the unnecessary elevation of medical care costs. To date, however, the available information on leftover hyperphosphatemia drugs in hemodialysis outpatients is limited. In this study, we performed an interview survey of medication adherence to hyperphosphatemia drugs among 60 hemodialysis outpatients and evaluated the cost of the leftover drugs. Thirty-four patients showed good adherence. On the other hand, 19 patients self-adjusted to take hyperphosphatemia drugs according to their daily diet. When assessing the serum phosphorus levels for these patients over the past year, the values often exceeded the targeted range (3.5-6.0 mg/mL). Furthermore, 35 patients kept hyperphosphatemia drugs at their home. When estimating the cost derived from leftover drugs using the bootstrap method, main distribution of drug cost was shown to be in the range of 2000 to 2500 yen. This drug cost seemed to in part reflect preparation for an emergency. A serious problem was that 14 patients had previous experience in discarding hyperphosphatemia drugs. This study suggested that more appropriate pharmaceutical care according to each patient's situation is essential in improving phosphorus control in hemodialysis outpatients and in reducing the waste of medical resources.

Inhibitory effects of indoxyl sulfate and creatinine on the renal transport of meropenem and biapenem in rats.

Carbapenem antibiotics are excreted preferentially in the urine after intravenous administration, with organic anion transporters (OATs) known to be involved in the renal tubular secretion of carbapenem antibiotics. Various uremic toxins (UTs) accumulate in the blood of patients with end-stage renal failure, and some UTs such as indoxyl sulfate (IS) and creatinine (Cr) are excreted in the urine via OATs. However, information about the possible interactions between these UTs and carbapenems in the renal secretion remains limited. In this study, we investigated the effects of IS and Cr on the renal transport of anionic meropenem and zwitterionic biapenem by using rat renal cortical slices. The uptake of meropenem and biapenem in the renal cortical slices was significantly decreased in the presence of 0.1 mM IS or 1 mM Cr. When biapenem and Cr were co-administered to rats intravenously, biapenem clearance from the plasma was clearly retarded, reflecting the current in vitro results. However, IS and Cr exerted no inhibitory effect on the uptake of metformin, a substrate of renal organic cation transporter (OCT) 2, in the renal cortical slices. Thus, our findings indicate that IS and Cr interfere with the renal secretion of carbapenem antibiotics by preferentially inhibiting OATs.