Distribution of urinary trace element exposure and dietary sources in women over 50 in an agricultural region- A community-based KoGES cohort study.

BACKGROUND: There is a noticeable lack of information on the levels of both non-essential and essential trace elements in women aged over 50. The main objective of this study is to investigate trace element concentrations and explore the influence of sociodemographic factors and dietary sources of exposure in this demographic. METHODS: We analyzed 19 trace elements, including manganese, cobalt, copper, zinc, molybdenum, chromium, nickel, arsenic, strontium, cadmium, tin, antimony, cesium, barium, tungsten, mercury, thallium, lead, and uranium, using ICP-MS and mercury analyzer. Urine samples were obtained from a cohort of 851 women aged over 50 who participated in the 8th KoGES-Ansung study (2017-2018). Multiple linear models were employed to explore associations between urinary trace element concentrations and sociodemographic factors and dietary sources of exposure. We used K-means clustering to discern patterns of exposure to trace elements and identify contributing factors and sources. RESULTS: Our findings indicate higher concentrations of molybdenum (Mo), arsenic (As), cadmium (Cd), and lead (Pb) in our study population compared to women in previous studies. The study population were clustered into two distinct groups, characterized by lower or higher urinary concentrations. Significant correlations between age and urinary concentrations were observed in Ni. Smoking exhibited positive associations with urinary Cd and As. Associations with dietary sources of trace elements were more distinct in women in the high-exposure group. Urinary antimony (Sb) was positively linked to mushroom and egg intake, As to mushroom and fish, and Hg to egg, dairy products, fish, seaweed, and shellfish. CONCLUSIONS: Our study underscores the significant gap in understanding urinary concentrations of trace elements in women aged over 50. With higher concentrations of certain elements compared to previous studies and significant correlations between age, smoking, and specific food sources, it is imperative to address this gap through targeted dietary source-specific risk management.

IDO1 scavenges reactive oxygen species in myeloid-derived suppressor cells to prevent graft-versus-host disease.

Tryptophan-catabolizing enzyme indoleamine 2,3-dioxygenase 1 (IDO1) also has an immunological function to suppress T cell activation in inflammatory circumstances, including graft-versus-host disease (GVHD), a fatal complication after allogeneic bone marrow transplantation (allo-BMT). Although the mononuclear cell expression of IDO1 has been associated with improved outcomes in GVHD, the underlying mechanisms remain unclear. Herein, we used IDO-deficient (Ido1-/-) BMT to understand why myeloid IDO limits the severity of GVHD. Hosts with Ido1-/- BM exhibited increased lethality, with enhanced proinflammatory and reduced regulatory T cell responses compared with wild type (WT) allo-BMT controls. Despite the comparable expression of the myeloid-derived suppressor cell (MDSC) mediators, arginase-1, inducible nitric oxide synthase, and interleukin 10, Ido1-/- Gr-1+CD11b+ cells from allo-BMT or in vitro BM culture showed compromised immune-suppressive functions and were skewed toward the Ly6ClowLy6Ghi subset, compared with the WT counterparts. Importantly, Ido1-/-Gr-1+CD11b+ cells exhibited elevated levels of reactive oxygen species (ROS) and neutrophil numbers. These characteristics were rescued by human IDO1 with intact heme-binding and catalytic activities and were recapitulated by the treatment of WT cells with the IDO1 inhibitor L1-methyl tryptophan. ROS scavenging by N-acetylcysteine reverted the Ido1-/-Gr-1+CD11b+ composition and function to an MDSC state, as well as improved the survival of GVHD hosts with Ido1-/- BM. In summary, myeloid-derived IDO1 enhances GVHD survival by regulating ROS levels and limiting the ability of Gr-1+CD11b+ MDSCs to differentiate into proinflammatory neutrophils. Our findings provide a mechanistic insight into the immune-regulatory roles of the metabolic enzyme IDO1.

Prenatal to peripubertal exposure to Di(2-ethylhexyl) phthalate induced endometrial atrophy and fibrosis in female mice.

Di(2-ethylhexy) phthalate (DEHP) is a widely used plasticizer that is ubiquitously found in the environment. Using a mouse model, we investigated the impact of early life DEHP exposure ranging from the prenatal to peripubertal developmental period of the female reproductive system. Pregnant female mice were allocated to three groups as follows: control, 100 mg/kg/day, and 500 mg/kg/day DEHP treatment. DEHP exposure was introduced through feeding during pregnancy (3 weeks) and lactation (3 weeks). After weaning, the offspring were also exposed to DEHP through feeding for another 2 weeks. Observations were conducted on female offspring at 10 and 24 weeks. The number of live offspring per dam was significantly lower in the high-DEHP-exposed group (500 mg/kg/day) compared to the control group (7.67 ± 1.24 vs. 14.17 ± 0.31; p < 0.05) despite no difference in pregnancy rates across the groups. Low-DEHP exposure (100 mg/kg/day) resulted to a decreased body weight (36.07 ± 3.78 vs. 50.11 ± 2.11 g; p < 0.05) and decreased left uterine length (10.60 ± 1.34 vs. 14.77 ± 0.82 mm; p < 0.05) in 24-week- old female mice. As early as 10 weeks, endometrial atrophy and fibrosis were observed, and endometrial cystic hyperplasia was noted in female mice at 24 weeks. Our study is the first to demonstrate that female mice exposed to DEHP in the early life developed endometrial fibrosis in the female offspring. Further studies on the consequences of these observations in fecundity and other reproductive functions are warranted.

Association between environmental chemical exposure and albumin-to-creatinine ratio is modified by hypertension status in women of reproductive age.

Chemicals have been identified as a potential risk factor of renal dysfunction. However, studies that consider both multiple chemicals and non-chemical risk factors, such as hypertension, are rare. In this study, we assessed the associations between exposure to several chemicals, including major metals, phthalates, and phenolic compounds, and the albumin-to-creatinine ratio (ACR). A group of Korean adult women in reproductive age (n = 438, aged between 20 and 49 years), who had previously been studied for association of several organic chemicals, was chosen for this purpose. We constructed multivariable linear regression models for individual chemicals and weighted-quantile sum (WQS) mixtures, by hypertension status. Among the study population, approximately 8.5% of the participants exhibited micro/macro-albuminuria (ACR ≥30 mg/g), and 18.5% and 3.9% exhibited prehypertension and hypertension, respectively. Blood cadmium and lead levels showed a stronger association with ACR only among women with prehypertension or hypertension. Among organic chemicals, depending on the statistial model, benzophenone-1 (BP-1) and mono(2-ethyl-5-hydroxyhexyl) phthalate (MEHHP) showed a significant association regardless of hypertension status, but most associations disappeared in the (pre)hypertensive group. These findings clearly indicate that hypertension status can modify and may potentiate the association of environmental chemicals with ACR. Our observations suggest that low-level environmental pollutant exposure may have potential adverse effects on kidney function among general adult women. Considering the prevalence of prehypertension in the general population, efforts to reduce exposure to cadmium and lead are necessary among adult women to minimize the risk of adverse kidney function.

Outcome of intraoperative injection of collagen in arthroscopic repair of full-thickness rotator cuff tear: a retrospective cohort study.

BACKGROUND: Rotator cuff (RC) pathologies are considered the most common cause of shoulder disability and pain. Arthroscopic repair of RC tears has proven to be an effective operation. Nonhealing and retear remain significant clinical problems and a challenge to surgeons. In addition, the essential biological augment to enhance RC tendon-bone healing is still under research. The purpose of the study was to assess the safety and efficacy of injection of atelocollagen and acellular dermal matrix (ADM) allograft in arthroscopic repair of full-thickness RC tears. METHODS: From January 2018 to March 2020, a total of 129 patients with full-thickness RC tear were treated by arthroscopic repair only (group 1, n = 36, with a mean age = 63.2 years), arthroscopic repair together with atelocollagen 1-mL injection (group 2, n = 44, with a mean age = 63 years), or RC tears together with ADM allograft 1-mL injection (group 3, n = 49, with a mean age = 64.6 years). They were prospectively studied. This study included patients with a repairable full-thickness tear of the supraspinatus tendon size <5 cm. We excluded patients with isolated tears of the subscapularis tendon, those with a previous shoulder surgery, and those who had any type of injection for less than 6 weeks. American Shoulder and Elbow Surgeons Standardized Shoulder Assessment Form score, Constant Shoulder score, visual analog scale pain score, and range of motion were evaluated preoperatively, at 3, 6, and 12 months of the postoperative period and the final follow-up. In addition, magnetic resonance imaging was performed at 2 months and 12 months postoperatively. RESULTS: The mean follow-up period was 20 months. All groups showed improvement in functional and pain score at the final follow-up; however, there is no superior outcome among the 3 groups (P > .05). After 2 months, the nonhealing rate was 11% (4 of 36) for group 1, 4% (2 of 44) for group 2, and 2% (1 of 49) for group 3 (P > .05). The retear rates after 12 months was 19.4% (7 of 36) for group 1, 13.6% (6 of 44) for group 2, and 20.4% (10 of 49) for group 3 (P > .05). Adverse events were not detected in any groups. CONCLUSION: Our study did not show superior clinical or radiologic outcomes of atelocollagen and ADM allograft injections in arthroscopic RC repair over 12 months of follow-up in comparison to the control group. However, adverse events related to atelocollagen and ADM allograft injection were not observed.

Biomarker-Determined Nonylphenol Exposure and Associated Risks in Children of Thailand, Indonesia, and Saudi Arabia.

Nonylphenol (NP) is an endocrine disruptor and environmental contaminant. Yet, data on individual body burdens and potential health risks in humans, especially among children, are scarce. We analyzed two specific urinary NP metabolites, hydroxy-NP (OH-NP) and oxo-NP. In contrast to parent NP, OH-NP has a much higher urinary excretion fraction (Fue), and both are insusceptible to external contamination. We investigated spot urine samples from school children of Thailand (n = 104), Indonesia (n = 89), and Saudi Arabia (n = 108) and could quantify OH-NP in 100% of Indonesian and Saudi children (median concentrations: 8.12 and 8.57 µg/L) and in 76% of Thai children (1.07 µg/L). Median oxo-NP concentrations were 0.95, 1.10, and <0.25 µg/L, respectively, in line with its lower Fue. Median daily NP intakes (DIs), back-calculated from urinary OH-NP concentrations, were significantly higher in Indonesia and Saudi Arabia [0.47 and 0.36 µg/(kg bw·d), respectively] than in Thailand [0.06 µg/(kg bw·d)]. Maximum DIs were close to the preliminary tolerable DI of 5 µg/(kg bw·d) from the Danish Environmental Protection Agency. Dominant sources of exposure or relevant exposure pathways could not be readily identified by questionnaire analyses and also potentially varied by region. The novel biomarkers provide long-needed support to the quantitative exposure and risk assessment of NP.

IL-7Rαlow CD8+ T Cells from Healthy Individuals Are Anergic with Defective Glycolysis.

Effector memory (EM) CD8+ T cells expressing lower levels of IL-7R α (IL-7Rαlow) from healthy individuals are partly compromised in vitro, but the identity of these cells has remained unclear. In this study, we demonstrate that human IL-7Rαlow EM CD8+ T cells are naturally occurring anergic cells in vivo and impaired in proliferation and IL-2 production but competent in IFN-γ and TNF-α production, a state that can be restored by IL-2 stimulation. IL-7Rαlow EM CD8+ T cells show decreased expression of GATA3 and c-MYC and are defective in metabolic reprogramming toward glycolysis, a process required for the proliferation of T cells. However, IL-7Rαlow EM CD8+ T cells can proliferate with TCR stimulation in the presence of IL-2 and IL-15, suggesting that these cells can be restored to normality or increased activity by inflammatory conditions and may serve as a reservoir for functional immunity.

Within- and between-person variability of urinary phthalate metabolites and bisphenol analogues over seven days: Considerations of biomonitoring study design.

Urine was used as a part of a human biomonitoring study based on the excretion kinetics of less-persistent contaminants, such as phthalates and bisphenol A (BPA). Despite the advantages of being non-invasive and easy to collect, urine can show a large variability of concentrations of phthalate metabolites and BPA within a person depending on sampling time. Therefore, it is essential to assess the variability of urinary concentrations for comprehensive sampling design in the context of exposure and risk assessments. In this study, 18 phthalate metabolites and eight BPs were measured in all spot urine (n = 401) collected from 12 participants for seven consecutive days to evaluate within- and between-person variabilities. The intraclass correlation coefficients (ICCs) for all spot urines were poor for monomethyl phthalate (ICC: 0.002) and BPA (0.121) but were moderate for monoethyl phthalate (0.514) and monobenzyl phthalate (0.462). Based on the results of di (2-ethylhexyl) phthalate (DEHP) metabolites, the half-life and differences in metabolic capability seem to affect the ICCs. Urinary mono (2-ethylhexyl) phthalate (MEHP), a primary metabolite of DEHP, was suggested as a short-term exposure marker of DEHP in our study. Creatinine- and specific gravity-adjusted concentrations of phthalate metabolites and BPs resulted in increased ICCs, implying requirements for randomly collected spot urine. Most analytes in the first morning voids (FMVs) were correlated significantly with those in the daily composites, suggesting the feasibility of FMVs to estimate the daily exposure dose. This study facilitates a more comprehensive sampling design and data interpretation strategy for human biomonitoring studies.

Sex, menopause, and age differences in the associations of persistent organic pollutants with thyroid hormones, thyroxine-binding globulin, and peripheral deiodinase activity: A cross-sectional study of the general Korean adult population.

Persistent organic pollutants (POPs) can disrupt the thyroid hormone system in humans. We assessed the associations of several POPs with serum thyroid hormones (T3 and T4) and thyroid-stimulating hormone, and investigated the modulating effects of sex, menopausal status, and age on these associations, in a subgroup of the adult population (n = 1250) from the Korean National Environmental Health Survey. PCB105 and PCB118 were negatively associated with total T4 in premenopausal females and males aged <50, whereas the associations were insignificant in other groups. PCB180, p,p'-DDE, and p,p'-DDT showed positive associations with total T3 in postmenopausal females; however, among males aged ≥50, PCB118, PCB138, and p,p'-DDE showed negative associations with total T3. The effects of exposure to multiple POPs were examined in multi-factor analyses. Factor 2 comprised PCB52, hexachlorobenzene, and BDE-47 was associated with an increase in free T4 in premenopausal females (ß = 0.015, p = 0.024), while Factor 1, which contained most POPs, was associated with a change in total T3 in postmenopausal females (ß = 0.032, p = 0.040) and males aged ≥50 (ß = -0.039, p = 0.023). Changes in total T4 or total T3 could be explained by differences in thyroxine-binding globulin (TBG) and peripheral deiodinase activity (GD). Negative associations of TBG with PCB105 in premenopausal females and PCB153 in males aged <50 may mediate the effect of decreasing total T4. PCB180, p,p'-DDE, p,p'-DDT, and Factor 1 were positively associated with GD, which is consistent with an increased total T3 in postmenopausal females. PCB118 was negatively associated with GD and total T3 in males aged ≥50. BDE-47 and ß-hexachlorocyclohexane were associated with thyroid autoantibodies in premenopausal females and males aged <50. Our observations suggest that the thyroid-disrupting effects of POPs may differ by sex, sex hormonal status, and age, and may be mediated by TBG and GD.

Lead, mercury, and cadmium exposures are associated with obesity but not with diabetes mellitus: Korean National Environmental Health Survey (KoNEHS) 2015-2017.

BACKGROUND: Associations of heavy metal exposures with obesity and obesity-related traits have been suggested, while those with nonalcoholic fatty liver disease (NAFLD) and diabetes mellitus (DM) are often inconsistent. METHODS: This study included 3787 adults aged ≥19 years who participated in the Korean National Environmental Health Survey 2015-2017, and investigated the association of toxic heavy metals with metabolic diseases. Lead (Pb), mercury (Hg), and cadmium (Cd) were measured either in urine (uHg, uCd) or total blood (bPb, bHg). Body mass index (BMI) was calculated, and DM cases were identified through a self-answered medication history. Hepatic Steatosis Index (HSI) as a surrogating index of NAFLD, was calculated using hepatic enzyme measurements, including aspartate aminotransferase (AST) and alanine aminotransferase (ALT). RESULTS: Adults in the highest quartile of bPb, bHg, and uHg showed significantly elevated odds of obesity (BMI ≥25 kg/m2), compared to the lowest quartile (OR 1.58 for bPb, 1.92 for bHg, and 1.81 for uHg). HSI was positively correlated with bHg, uHg, and uCd concentrations. The odds of NAFLD (HSI ≥36) were also increased with increasing quartile of bHg, uHg, and uCd concentrations. For DM, bPb showed a significant negative association, while bHg and uCd exhibited non-monotonic and inconclusive associations. CONCLUSIONS: Among the general adult population of Korea, both Pb and Hg exposures were associated with an increased risk of obesity. In addition, both Hg and Cd exposures were associated with increased odds of NAFLD. These metals, however, were not associated with an increased risk of DM.

Zebrafish (Danio rerio) as a model organism for screening nephrotoxic chemicals and related mechanisms.

Because of essential role in homeostasis of the body fluid and excretion of wastes, kidney damage can lead to severe impacts on health and survival of humans. For most chemicals, nephrotoxic potentials and associated mechanisms are unclear. Hence, fast and sensitive screening measures for nephrotoxic chemicals are required. In this study, the utility of zebrafish (Danio rerio) was evaluated for the investigation of chemical-induced kidney toxicity and associated modes of toxicity, based on the literature review. Zebrafish has a well-understood biology, and many overlapping physiological characteristics with mammals. One such characteristic is its kidneys, of which histology and functions are similar to those of mammals, although unique differences of zebrafish kidneys, such as kidney marrow, should be noted. Moreover, the zebrafish kidney is simpler in structure and easy to observe. For these advantages, zebrafish has been increasingly used as an experimental model for screening nephrotoxicity of chemicals and for understanding related mechanisms. Multiple endpoints of zebrafish model, from functional level, i.e., glomerular filtration, to transcriptional changes of key genes, have been assessed to identify chemical-induced kidney toxicities, and to elucidate underlying mechanisms. The most frequently studied mechanisms of chemical-induced nephrotoxicity in zebrafish include oxidative stress, inflammation, DNA damage, apoptosis, fibrosis, and cell death. To date, several pharmaceuticals, oxidizing agents, natural products, biocides, alcohols, and consumer chemicals have been demonstrated to exert different types of kidney toxicities in zebrafish. The present review shows that zebrafish model can be efficiently employed for quick and reliable assessment of kidney damage potentials of chemicals, and related toxic mechanisms. The toxicological information obtained from this model can be utilized for identification of nephrotoxic chemicals and hence for protection of public health.

Urinary Concentrations of Major Phthalate and Alternative Plasticizer Metabolites in Children of Thailand, Indonesia, and Saudi Arabia, and Associated Risks.

Phthalates are widely used in consumer products and are well-known for adverse endocrine outcomes. Di-(2-ethylhexyl) phthalate (DEHP), one of the most extensively used phthalates, has been rapidly substituted with alternative plasticizers in many consumer products. The aim of this study was to assess urinary phthalate and alternative plasticizer exposure and associated risks in children of three Asian countries with different geographical, climate, and cultural characteristics. Children were recruited from elementary schools of Saudi Arabia (n = 109), Thailand (n = 104), and Indonesia (n = 89) in 2017-2018, and their urine samples were collected. Metabolites of major phthalates and alternative plasticizers were measured in the urine samples by HPLC-MS/MS. Urinary metabolite levels differed substantially between the three countries. Metabolite levels of diisononyl phthalate (DiNP), diisodecyl phthalate (DiDP), di(2-ethylhexyl) terephthalate (DEHTP), and 1,2-cyclohexane dicarboxylic acid diisononyl ester (DINCH) were the highest in Saudi children: Median urinary concentrations of oxo-MiNP, OH-MiDP, 5cx-MEPTP, and OH-MINCH were 8.3, 8.4, 128.0, and 2.9 ng/mL, respectively. Urinary DEHP metabolite concentrations were the highest in the Indonesian children. The hazard index (HI) derived for the plasticizers with antiandrogenicity based reference doses (RfDAA) was >1 in 86%, 80%, and 49% of the Saudi, Indonesian, and Thai children, respectively. DEHP was identified as a common major risk driver for the children of all three countries, followed by DnBP and DiBP depending on the country. Among alternative plasticizers, urinary DEHTP metabolites were detected at levels comparable to those of DEHP metabolites or higher among the Saudi children, and about 4% of the Saudi children exceeded the health based human biomonitoring (HBM)-I value. Priority plasticizers that were identified among the children of three countries warrant refined exposure assessment for source identification and relevant exposure reduction measures.

Variability of urinary creatinine, specific gravity, and osmolality over the course of pregnancy: Implications in exposure assessment among pregnant women.

Due to dilution status of the urine, chemical concentrations measured in spot urine are frequently adjusted using correction factors, such as creatinine, specific gravity (SG), or osmolarity of the urine. Urinary correction factors, however, can be influenced dramatically by physiological changes such as pregnancy. Details about the variation of urine dilution over the course of pregnancy are not well characterized. In the present study, we investigated the variation of urine correction factors over time among the pregnant women of Korea (n = 69) and Thailand (n = 102). Creatinine, SG, and osmolality were determined in the urine samples obtained in each trimester of the participating women, and were compared by sampling time and by nationality. Implication of the variation in these correction factors was studied using phthalate metabolites measured in the urine samples as model chemicals. Urinary correction factors significantly varied across the trimesters especially in Korean pregnant women: urinary creatinine and osmolality were significantly lower in the third trimester (T3) urine than the first trimester (T1) urine. Urinary creatinine and SG of the T3 urine of Korean pregnant women were also significantly lower than those reported from the non-pregnant women who participated in Korean National Environmental Health Survey (KoNEHS) 2015-2017. Among Thai women, however, these correction factors were rather stable across the pregnancy. Differences in ethnicity, or in behavior such as water consumption amount may partly explain the differences. Temporal changes in these urine correction factors influenced the urinary phthalate metabolite concentrations adjusted for dilution, in both Korean and Thai pregnant women. The present observations show that the variations of urinary correction factors should be considered in exposure assessment of urinary chemicals for pregnant women, in order to circumvent potential bias due to physiological changes occurring during pregnancy, and to reduce errors in exposure classification and association.

Lead and mercury levels in repeatedly collected urine samples of young children: A longitudinal biomonitoring study.

Early life exposures to lead (Pb) and mercury (Hg) were reported to be associated with various adverse health outcomes. However, limited data was available for urinary Pb and Hg levels in young children and the proportion of children at risk by age, as well as inter- and intra-subject variations of urinary Pb and Hg levels. Therefore, we collected total 491 urine samples from 241 children by urine collection at birth and at intervals of 3 months until 27 months of age for each child (at 10 monitoring time points), measured urinary Pb and Hg levels, and then evaluated the proportion of children at risk by age and the intra-class correlation (ICC) of the urinary Pb and Hg levels. Both the urinary Pb and Hg levels were significantly different according to the monitoring time points (p < 0.0001 for both Pb and Hg). The number of children with Hg level over the Human BioMonitoring (HBM) I (7 µg/L) and II (25 µg/L) in the first urine at birth were 3 (2.2%) and 1 (0.7%), respectively, while the urinary samples at the other time points did not show Hg level over HBM I or HBM II. However, the exceedance rate for urinary Pb based on HBM values was not calculated due to unavailable HBM values. On the other hands, the proportion of the children with Pb and Hg levels over the reference value derived on the 95th percentile of representative samples (RV95) (1.7 µg/L for Canadian Pb and 0.4 µg/L for German Hg) was relatively high, ranging from 20.0% to 100.0% for Pb and from 13.6% to 100.0% for Hg. The ICC of the repeated measurements from birth to 27 months was 0 for Pb and 0.89 for Hg, while the ICC after the exclusion of the first urine at birth was 0.13 for Pb and 0.47 for Hg. Furthermore, the Pb and Hg exposures were consistent among the high-exposure group for Pb and among all population for Hg. Our data showed Korean children were exposed to relatively high levels of Pb and Hg. However, our Pb and Hg levels in children were based on only urine samples without urinary correction and without consideration of the levels in any other bio-samples such as bloods. Therefore, to explore the Pb and Hg exposures using urine samples warrant further investigation with large sample size considering urinary correction and other bio-samples in the future.

Exposure to organophosphate esters, phthalates, and alternative plasticizers in association with uterine fibroids.

Exposure to endocrine disrupting chemicals is suggested to be responsible for the development or progression of uterine fibroids. However, little is known about risks related to emerging chemicals, such as organophosphate esters (OPEs) and alternative plasticizers (APs). A case-control study was conducted to investigate whether exposures to OPEs, APs, and phthalates, were associated with uterine fibroids in women of reproductive age. For this purpose, the cases (n = 32) and the matching controls (n = 79) were chosen based on the results of gynecologic ultrasonography among premenopausal adult women in Korea and measured for metabolites of several OPEs, APs, and major phthalates. Logistic regression models were employed to assess the associations between chemical exposure and disease status. Factor analysis was conducted for multiple chemical exposure assessments as a secondary analysis. Among OPE metabolites, diphenyl phosphate (DPHP), 2-ethylhexyl phenyl phosphate (EHPHP), and 1-hydroxy-2-propyl bis(1-chloro-2-propyl) phosphate (BCIPHIPP) were detected in >80% of the subjects. Among APs, metabolites of di-isononyl phthalate (DINP) and di(2-propylheptyl) phthalate (DPrHpP) were detected in >75% of the urine samples. The odds ratios (ORs) of uterine fibroids were significantly higher among the women with higher exposures to tris(1,3-dichloro-2-propyl) phosphate (TDCIPP) and tris(2-butoxyethyl) phosphate (TBOEP), di(2-ethylhexyl) terephthalate (DEHTP), DPrHpP, and di-(iso-nonyl)-cyclohexane-1,2-dicarboxylate (DINCH). In addition, urinary concentrations of mono(2-ethyl-5-oxohexyl) phthalate (MEOHP), a sum of five di(2-ethylhexyl) phthalate metabolites (∑5DEHP), and mono(4-methyl-7-hydroxyoctyl) phthalate (OH-MINP) were significantly higher in the cases. In factor analysis, a factor heavily loaded with DPrHpP and DEHP was significantly associated with uterine fibroids, supporting the observation from the single chemical regression model. We found for the first time that several metabolites of OPEs and APs are associated with increased risks of uterine fibroids among pre-menopausal women. Further epidemiological and mechanistic studies are warranted to validate the associations observed in the present study.

Comparative analysis of endocrine disrupting effects of major phthalates in employed two cell lines (MVLN and H295R) and embryonic zebrafish assay.

Endocrine disruption potentials of phthalates have been widely recognized, but relatively little is known about relative potency of major phthalates. In the present study, six phthalates were chosen, i.e., dimethyl phthalate (DMP), diethyl phthalate (DEP), di(2-ethylhexyl) phthalate (DEHP), di-n-octyl phthalate (DnOP), diisononyl phthalate (DINP) and diisodecyl phthalate (DIDP), and their endocrine disruption effects were evaluated by employing two cell lines and an embryonic zebrafish assay. Binding affinity with estrogen receptors (ERs) and effects on steroidogenesis were evaluated with MVLN and H295R cell assays, respectively. In zebrafish embryos, transcription of genes regulating steroid hormone balance and estrogen receptors was measured. Exposure to DMP, DEP, DEHP, and DnOP significantly increased E2/T ratio in H295R cells. However, no significant binding affinity to ERs was observed in MLVN cells. Exposure to DEHP influenced the expression of vtg1, esr1, and cyp19a1b genes in zebrafish larvae. DMP, DEP, DINP, and DIDP exposure led to significant transcriptional changes even at lower exposure concentrations, suggesting their greater endocrine disruption potency than DEHP in zebrafish. Our findings demonstrate that endocrine disruption upon phthalate exposure varies between in vitro and in vivo assay, and a battery of tests are warranted to understand endocrine disruption potentials of phthalates. Consequences of long-term exposure to phthalates other than DEHP warrant further evaluations.

Rapid screening for ecotoxicity of plating and semiconductor wastewater employing the heartbeat of Daphnia magna.

Industrial wastewater discharge is one of major threats to the sustainability of aquatic environment. Rapid and sensitive detection of toxic wastewater discharge and appropriate control if necessary are therefore crucial. In the present study, a 1 h Daphnia magna exposure with heartbeat as an observation endpoint was developed and assessed for its utility as a rapid toxicity screening measure. Two types of metal-rich industrial wastewater, i.e., metal plating and the semiconductor industry were chosen as target samples, and the 1 h heartbeat assay was applied. Based on a literature search, four metals, i.e., Cu, Cr, Ni and Zn were identified as major chemicals of ecotoxicological concerns in these wastewaters. The effective concentrations determined for each metal from the D. magna 1 h heartbeat test were comparable to those derived from the conventional D. magna 48 h immobilization test. Copper sulfate (CuSO4) was determined as the most toxic, followed by potassium dichromate (K2Cr2O7), nickel sulfate (NiSO4) and zinc sulfate (ZnSO4). For ternary mixtures, the 1 h heartbeat test showed also comparable responses to those of the 48 h immobilization test, suggesting its utility for screening the toxicity of simple metal mixtures. For the site-sampled metal plating water, the rapid heartbeat assay showed similar responses to those of the 48 h immobilization assay. However, for the semiconductor industry wastewater, clearly different responses were observed in both the heartbeat and immobilization assays, probably due to the influence of other contaminants with different modes of action that are present in the wastewater. Our observations showed that the D. magna 1 h heartbeat test can be considered as a rapid ecotoxicity screening measure for certain wastewaters with simple metal mixtures.

Effects of tris(1,3-dichloro-2-propyl) phosphate (TDCPP) and triphenyl phosphate (TPP) on sex-dependent alterations of thyroid hormones in adult zebrafish.

Organophosphate flame retardants (OPFRs) have been widely used as alternatives to polybrominated diphenyl ethers for fire prevention. OPFRs are suspected of causing potential thyroid disruption in humans. In fish, their thyroid hormone modulation is reported but the mechanisms of this modulation are less understood. Thyroid-disturbing effects of OPFRs were evaluated using adult zebrafish (Danio rerio) following 14d exposure to tris(1,3-dichloro-2-propyl) phosphate (TDCPP) or triphenyl phosphate (TPP). Plasma concentrations of thyroid hormones were measured and transcriptions of several genes involved in thyroid function were quantified in brain, thyroid, and liver. Exposure to TDCPP or TPP led to significant decreases in plasma triiodothyronine (T3) and thyroxine (T4) concentrations in the male fish, while the increases were observed in the female fish. Exposure to the OPFRs also altered the transcription of regulatory genes and receptors in hypothalamus, pituitary, and thyroid of the fish in sex-dependent manner. In the male fish, transcriptions of corticotropin-releasing hormone (crh) and thyroid-stimulating hormone (tsh) in the brain were significantly up-regulated, probably as a compensation for hypothyroidism, but thyroglobulin (tg) and deiodinase 2 (dio2) were down-regulated in thyroid or liver. In contrast, in the females, transcriptions of crh and tsh genes were significantly down-regulated. These observations show that TDCPP and TPP exposure can lead to sex-dependent disruptions of thyroid hormone balances in the adult zebrafish through alterations of the hypothalamus-pituitary-thyroid (HPT) axis.

Endocrine disruption by several aniline derivatives and related mechanisms in a human adrenal H295R cell line and adult male zebrafish.

Aniline and aniline derivatives have been widely used in the production of pesticides, pharmaceuticals, cosmetic, dyes, rubber, and adhesives products. These chemicals can easily be released into the environment through industrial and municipal discharges or as degradation byproducts. Several studies have suggested that aniline and some of its derivatives could cause reproductive toxicity in aquatic organisms. However, knowledge on the endocrine disruption potentials of these chemicals is limited only to aniline and associated mechanisms are rarely investigated. The objective of this study was to investigate the potential of major aniline derivatives, i.e., 3,4-dichloroaniline (3,4-DCA), 1-naphthylamine (1-NPA), and 4,4'-methylenedianiline (4,4'-MDA), to disrupt sex steroid production and other biological processes. For this purpose, the human adrenal H295R cell line and adult male zebrafish (Danio rerio) were used. In the H295R cell line, all tested aniline derivatives decreased testosterone (T) levels. Regulatory changes of several steroidogenic genes, i.e., down-regulation of StAR or CYP17 genes, and up-regulation of CYP19A, observed in the H295R cells could explain the sex hormone disruption. In male zebrafish, generally similar directions of changes, i.e., decreases in T levels and increased E2/T ratios, were observed. Again, down-regulation of key steroidogenic genes such as cyp17 or 3ß-hsd, but slight up-regulation of cyp19a gene observed in the fish could explain the sex hormone changes. The results of our study demonstrate that all tested aniline derivatives could influence steroidogenesis and disrupt sex hormone balance toward reduced androgenicity. Consequences of anti-androgenicity following long-term exposure warrant further investigation.

Effects of gemfibrozil on sex hormones and reproduction related performances of Oryzias latipes following long-term (155 d) and short-term (21 d) exposure.

Gemfibrozil, a lipid-regulating pharmaceutical, has been widely used for treating dyslipidemia in humans and detected frequently in freshwater environments. Since plasma cholesterol is a precursor of steroid hormones, the use of gemfibrozil may influence the sex hormone balances. However, its endocrine toxicity following long-term exposure is not well understood. The purpose of the present study is to investigate the effects of gemfibrozil on sex hormones and reproductive outcomes in a freshwater fish, following a long-term (155 d) exposure. For this purpose, Japanese medaka embryos (F0) were exposed to a series of gemfibrozil concentrations, i.e., 0, 0.04, 0.4, 3.7, and 40 mg/L for 155 d, and reproductive parameters, sex hormones, and associated gene expressions were assessed. For comparison, a short-term exposure (21 d) was performed separately with adult medaka and measured for sex hormones and related gene expressions. Following the 155 d long-term exposure, the fecundity showed a decreasing pattern. In addition, at 3.7 mg/L gemfibrozil, testosterone (T) level in the female fish was significantly decreased, and the hatchability of F1 fish was significantly decreased. The estrogen receptor (er) or vitellogenin (vtg) genes in gonads and liver were up-regulated. However, plasma cholesterol levels did not show significant changes in both sexes. The observations from the short-term (21 d) exposure were different from those of the long-term exposure. Following the short-term exposure, decreased 17ß-estradiol (E2), and 11-ketotestosterone (11-KT) levels along with decrease plasma cholesterol were observed in the male fish. The hormone disruption following the short-term exposure appears to be associated with the hypocholesterolemic activity of gemfibrozil. Our results show that the mechanisms of gemfibrozil toxicity may depend on the exposure duration. Consequences of long-term exposure to other fibrates in the water environment warrant further investigations.