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Human exposure to pentabromodiphenyl ether (PBDE) mixture (DE-71) and its PBDE-47 congener can occur both in utero and during lactation. Here we tested the hypothesis that PBDE-induced neonatal hepatic transcriptomic alterations in Wistar Han rat pups can inform on potential toxicity and carcinogenicity after longer-term PBDE exposures. Wistar Han rat dams were exposed to either DE-71 or PBDE-47 daily from gestation day (GD 6) through postnatal day four (PND 4). Total plasma thyroxine (T4) was decreased in PND 4 pups. In liver, transcripts for CYPs and conjugation enzymes, Nrf2, and ABC transporters were upregulated. In general, the hepatic transcriptomic alterations after exposure to DE-71 or PBDE-47 were similar and provided early indicators of oxidative stress and metabolic alterations, key characteristics of toxicity processes. Based on liver transcript patterns, the mean BMDLs (mean benchmark dose, lower confidence limit) of the most sensitive biological processes were lower for PBDE-47 than for the PBDE mixture. Neonatal rat liver transcriptomic data provide early indicators on molecular pathway alterations that may lead to toxicity and/or carcinogenicity if the exposures continue for longer durations. These early toxicogenomic indicators may be used to help prioritize chemicals for a more complete toxicity and cancer risk evaluation.

Pentabromodiphenyl ethers (PBDE) are found in human tissue, in household dust, and in the environment, and a particular concern is the potential for the induction of cancer pathways from these fat-soluble persistent organic pollutants. Only one PBDE cancer study has been conducted and that was for a PBDE mixture (DE-71). Because it is not feasible to test all PBDE congeners in the environment for cancer potential, it is important to develop a set of biological endpoints that can be used in short-term toxicity studies to predict disease outcome after long-term exposures. In this study, PBDE-47 was selected as the test PBDE congener to evaluate and compare toxicity to that of the carcinogenic PBDE mixture. The toxicities of PBDE-47 and the PBDE mixture were evaluated at PND 22 in Wistar Han rat (Crl: WI (Han)) pups after in utero/postnatal exposure (0, 0.1, 15, or 50 mg/kg; dams, GD6-21; pups, PND 12-PND 21; oral gavage daily dosing). By PND 22, PBDE-47 caused centrilobular hypertrophy and fatty change in liver, and reduced serum thyroxin (T(4)) levels; similar effects were also observed after PBDE mixture exposure. Transcriptomic changes in the liver included induction of cytochrome p450 transcripts and up-regulation of Nrf2 antioxidant pathway transcripts and ABC membrane transport transcripts. Decreases in other transport transcripts (ABCG5 & 8) provided a plausible mechanism for lipid accumulation, characterized by a treatment-related liver fatty change after PBDE-47 and PBDE mixture exposure. The benchmark dose calculation based on liver transcriptomic data was generally lower for PBDE-47 than for the PBDE mixture. The up-regulation of the Nrf2 antioxidant pathway and changes in metabolic transcripts after PBDE-47 and PBDE mixture exposure suggest that PBDE-47, like the PBDE mixture (NTP 2016, TR 589), could be a liver toxin/carcinogen after long-term exposure.

Background Evidence from animal studies suggests that DDT and DDE can adversely affect immuno-competence while human data are less conclusive. We aimed to assess the association of plasma concentrations of DDT and DDE with biomarkers of inflammation among reproductive-aged women residing in homes sprayed with DDT through Indoor Residual Spraying (IRS). Methods This study included 416 women from the Study of Women and Babies, South Africa (2010–2011). DDT, DDE, and biomarkers of inflammation (immunoglobulins A, G and M, interleukins 1β, 6, and 8, tumor necrosis factor-α, C-reactive protein, serum amyloid-A, intercellular adhesion molecule-1, vascular cell adhesion molecule-1) were quantified in plasma. Linear regression was used to assess associations of DDT and DDE with each natural log-transformed biomarker. Models were adjusted for age, body mass index, parity, income, and season; beta estimates were expressed as percent differences. Results Compared to women with the lowest plasma concentrations of DDT and DDE, those with the highest concentrations of both compounds had higher levels IL-1β, IL6, and TNF- α. While associations were statistically significant for both DDT and DDE, the magnitude of the associations was slightly stronger for DDT. Compared to women in the lowest quintile of DDT, women in the highest quintile were estimated to have 53.0% (95%CI: 21.7%, 84.4%), 28.1% (95%CI: 6.4%, 49.8%), and 26.6% (95%CI: 12.0%, 41.1%) higher levels of IL-1β, IL6, and TNF- α, respectively. Conclusions Our results suggest that increased plasma concentrations of DDT and DDE resulting from exposure to IRS may increase concentrations of pro-inflammatory biomarkers among reproductive-aged women in South Africa.

Background:Pregnant women who are physically active have a lower risk of preeclampsia and gestational diabetes than women who are less active. One possible mechanism is a reduction in low-grade inflammation, as measured by plasma concentrations of C-reactive protein (CRP). The association between exercise and CRP in pregnant women, however, has not been adequately investigated.Methods:A total of 537 pregnant women, enrolled around the 17th week of gestation in the Norwegian Mother and Child Cohort Study in 2003 to 2004, were studied. Self-reported recreational exercise was recalled for both 3 months before pregnancy and early pregnancy. The total energy expenditure from recreational exercise (total recreational exercise, metabolic equivalent of task [MET]-hr/week) was estimated, and low-, moderate- and vigorous-intensity exercise was defined. Plasma CRP concentrations were measured during pregnancy.Results:In adjusted linear regression models, mean CRP concentration was 1.0% lower [95% CI = –1.9% to 0.2%] with each 1 MET-hr/week of total recreational exercise before pregnancy. In addition, vigorous-intensity exercise before pregnancy was more strongly related to a reduction in CRP levels than low- or moderate-intensity exercise. However, we observed no association between recreational exercise during pregnancy and plasma CRP levels.Conclusion:Recreational exercise before pregnancy, especially vigorous exercise, may reduce the risk of maternal inflammation during pregnancy.

At elevated levels, fluoride (F−) exposure has been associated with adverse human health effects. In rodents, F− exposure has been reported to induce deficits in motor performance and learning and memory. In this study, we examined Long-Evans hooded male rats maintained on a standard diet (20.5 ppm F−) or a low F− diet (3.24 ppm F−) with drinking water exposure to 0, 10, or 20 ppm F− from gestational day 6 through adulthood. At postnatal day 25, brain F− levels were 0.048 or 0.081 μg/g and femur 235 or 379.8 μg/g for 10 and 20 ppm F−, respectively. Levels increase with age and in adults, levels for plasma were 0.036 or 0.025 μg/ml; for the brain 0.266 or 0.850 μg/g; and for the femur, 681.2 or 993.4 μg/g. At these exposure levels, we observed no exposure-related differences in motor, sensory, or learning and memory performance on running wheel, open-field activity, light/dark place preference, elevated plus maze, pre-pulse startle inhibition, passive avoidance, hot-plate latency, Morris water maze acquisition, probe test, reversal learning, and Y-maze. Serum triiodothyronine (T3), thyroxine (T4), and thyroid stimulating hormone (TSH) levels were not altered as a function of 10 or 20 ppm F− in the drinking water. No exposure-related pathology was observed in the heart, liver, kidney, testes, seminal vesicles, or epididymides. Mild inflammation in the prostate gland was observed at 20 ppm F−. No evidence of neuronal death or glial activation was observed in the hippocampus at 20 ppm F−. Electronic supplementary material The online version of this article (10.1007/s12640-018-9870-x) contains supplementary material, which is available to authorized users.

Black cohosh rhizome, available as a dietary supplement, is most commonly marketed as a remedy for dysmenorrhea and menopausal symptoms. A previous subchronic toxicity study of black cohosh dried ethanolic extract (BCE) in female mice revealed a dose-dependent ineffective erythropoiesis with a macrocytosis consistent with the condition known as megaloblastic anemia. The purpose of this study was to investigate potential mechanisms by which BCE induces these particular hematological changes. B6C3F1/N female mice (32/group) were exposed by gavage to vehicle or 1,000 mg/kg BCE for 92 days. Blood samples were analyzed for hematology, renal and hepatic clinical chemistry, serum folate and cobalamin, red blood cell (RBC) folate, and plasma homocysteine and methylmalonic acid (MMA). Folate levels were measured in liver and kidney. Hematological changes included decreased RBC count; increased mean corpuscular volume; and decreased reticulocyte, white blood cell, neutrophil, and lymphocyte counts. Blood smear evaluation revealed increased Howell–Jolly bodies and occasional basophilic stippling in treated animals. Plasma homocysteine and MMA concentrations were increased in treated animals. Under the conditions of our study, BCE administration caused hematological and clinical chemistry changes consistent with a functional cobalamin, and possibly folate, deficiency. Further studies are needed to elucidate the mechanism by which BCE causes increases in homocysteine and MMA.

Background: Perfluoroalkyl substances (PFASs) are widespread and persistent environmental pollutants. Previous studies, primarily among non-pregnant individuals, suggest positive associations between PFAS levels and certain blood lipids. If there is a causal link between PFAS concentrations and elevated lipids during pregnancy, this may suggest a mechanism by which PFAS exposure leads to certain adverse pregnancy outcomes, including preeclampsia. Methods: This cross-sectional analysis included 891 pregnant women enrolled in the Norwegian Mother and Child (MoBa) Cohort Study in 2003–2004. Non-fasting plasma samples were obtained at mid-pregnancy and analyzed for nineteen PFASs. Total cholesterol, high-density lipoprotein (HDL) cholesterol, low-density lipoprotein cholesterol, and triglycerides were measured in plasma. Linear regression was used to quantify associations between each PFAS exposure and each lipid outcome. A multiple PFAS model was also fitted. Results: Seven PFASs were quantifiable in >50% of samples. Perfluorooctane sulfonate (PFOS) concentration was associated with total cholesterol, which increased 4.2 mg/dL per inter-quartile shift (95% CI = 0.8, 7.7) in adjusted models. Five of the seven PFASs studied were positively associated with HDL cholesterol, and all seven had elevated HDL associated with the highest quartile of exposure. Perfluoroundecanoic acid showed the strongest association with HDL: HDL increased 3.7 mg/dL per inter-quartile shift (95% CI = 2.5, 4.9). Conclusion: Plasma concentrations of PFASs were positively associated with HDL cholesterol, and PFOS was positively associated with total cholesterol in this sample of pregnant Norwegian women. While elevated HDL is not an adverse outcome per se, elevated total cholesterol associated with PFASs during pregnancy could be of concern if causal. Keywords: The Norwegian Mother and Child Cohort Study, MoBa, Perfluoroalkyl substances, Perfluorooctanoic acid, Perfluorooctane sulfonate

Perfluorinated and polyfluorinated compounds (PFCs) are man-made chemicals produced since the 1950s and extensively used in a wide range of industrial and consumer applications, including polymers, repellents, surfactants, adhesives, food packaging, and fire-fighting foams.1 These compounds are characterized by a hydrophilic head moiety attached to a hydrophobic carbon chain of varying length that is saturated with fluorine atoms (perfluorinated).2 Due to their extreme resistance to degradation and potential to bioaccumulate, PFCs have been found in practically all environmental media and biota worldwide, including humans.3,4 PFCs have been found in non-occupationally exposed adults, children, cord blood, and human breastmilk.5-9 The most widely studied PFCs are perfluorooctane sulfonate (PFOS) and perfluorooctanoate (PFOA). Their half-lives in humans have been determined in retired workers from PFC production facilities, with a median of 4.6 years for PFOS and 3.4 years for PFOA.10 Due to the environmental behavior and toxicity of PFCs, the major producer of PFOS has phased out its production, and its use has been restricted under the Stockholm Convention on Persistent Organic Pollutants (http://chm.pops.int). Further measures have been introduced to reduce industrial emissions of PFOA.11 Following these measures, studies have demonstrated a decrease in body burdens of PFOS and PFOA since around the year 2000.12,13 Nevertheless, human health concerns regarding exposure to low levels of PFCs persist. The toxicity of PFOS and PFOA has been extensively studied in experimental animals, with hepatotoxicty, developmental toxicity, immunotoxicity, hormonal effects, and carcinogenicity identified as the effects of most concern.14,15 In contrast, epidemiologic studies of the relation between PFCs and various health outcomes are limited and inconsistent. A recent study of pregnant women in the Danish National Birth Cohort linked maternal serum concentrations of PFCs with subfecundity,16 finding increased relative odds of subfecundity among women in the highest quartile of both PFOS (odds ratio [OR]=1.8 [95% confidence interval (CI)=1.1-3.0]) and PFOA (2.5 [1.5-4.4]). A woman’s pregnancy history and previous duration of breastfeeding may be important determinants of her PFC body burden and, therefore, influence her PFC plasma concentration.17,18 PFOS and PFOA have been quantified in cord blood, demonstrating their ability to cross the placental barrier.5,8,9 Studies have also documented declining maternal levels of PFOS and PFOA during pregnancy5,9 and declining maternal levels of PFOA following delivery.5 Further, PFCs have been detected in breast milk7, a recent study among primarily breastfed infants reported lower maternal PFOS and PFOA concentrations six months after birth compared with pregnancy levels.5 Further, the PFC body burden among parous women will be affected by the elapsed time since the previous birth (interpregnancy interval). The longer the interpregnancy interval, the greater amount of time there will be for PFC levels to increase toward prepregnancy baseline following the previous birth. The interpregnancy interval is also a reflection, in part, of the woman’s underlying fecundability, which is the construct being measured by time to pregnancy. It is possible among parous women for an association between PFC levels and time to pregnacy, to be due to reverse causality. That is, parous women with long times to pregnancy have higher PFC levels because they also have long interpregnancy intervals. In the previous Danish study of PFC levels and subfecundity, separate effect estimates for parous and nulliparous women were not provided. Due to the potential for reverse causality, it is important to distinguish between women with or without a prior pregnancy. The goal of the present study was to examine the relation between PFOS and PFOA and subfecundity, with separate analyses for parous and nulliparous women.

Obesity and obesity-related illnesses are global epidemics impacting the health of adults and children. The purpose of the present work is to evaluate a genetically intact obese mouse model that more accurately reflects the impact of aging on diet-induced obesity and type 2 diabetes in humans. Male C57Bl/6J mice consumed either a control diet or one in which 60% kcal were due to lard beginning at 5–6 weeks of age. Body weight and fat measurements were obtained and necropsy performed at 15, 20, 30, and 40 weeks of age. Serum chemistry, histopathology, gene expression of the liver, and renal and hepatic function were also evaluated. In concert with significant increases in percent body fat and weight, mice fed the high-fat versus control diet had significantly increased levels of serum cholesterol. At ages 20 and 30 weeks, serum glucose was significantly higher in obese versus controls, while serum insulin levels were ≥4-fold higher in obese mice at ages 30 and 40 weeks. The effect of age exacerbated the effects of consuming a high-fat diet. In addition to being hyperinsulinemic and leptin resistant, older obese mice exhibited elevated hepatic PAI-1 and downregulation of GLUT4, G6PC, IGFBP-1, and leptin receptor mRNA in the liver, steatosis with subsequent inflammation, glomerular mesangial proliferation, elevated serum ALT, AST, and BUN, and increased numbers of pancreatic islets.

Clinical chemistry data are routinely generated as part of preclinical animal toxicity studies and human clinical studies. With large-scale studies involving hundreds or even thousands of samples in multiple treatment groups, it is currently difficult to interpret the resulting complex, high-density clinical chemistry data. Accordingly, we conducted this study to investigate methods for easy visualization of complex, high-density data. Clinical chemistry data were obtained from male rats each treated with one of eight different acute hepatotoxicants from a large-scale toxicogenomics study. The raw data underwent a Z-score transformation comparing each individual animal's clinical chemistry values to that of reference controls from all eight studies and then were visualized in a single graphic using a heat map. The utility of using a heat map to visualize high-density clinical chemistry data was explored by clustering changes in clinical chemistry values for >400 animals. A clear distinction was observed in animals displaying hepatotoxicity from those that did not. Additionally, while animals experiencing hepatotoxicity showed many similarities in the observed clinical chemistry alterations, distinct differences were noted in the heat map profile for the different compounds. Using a heat map to visualize complex, high-density clinical chemistry data in a single graphic facilitates the identification of previously unrecognized trends. This method is simple to implement and maintains the biological integrity of the data. The value of this clinical chemistry data transformation and visualization will manifest itself through integration with other high-density data, such as genomics data, to study physiology at the systems level.

Objective Maternal nutrition has long-term effects on offspring characteristics. Similar effects mediated through fathers have not been tested. Methods Outbred Swiss male mice were fasted one or six times 1 to 4 wk before mating. Offspring were killed at age intervals of 4 to 10 wk and their sera were analyzed for glucose, corticosterone, and insulin-like growth factor-1. Statistical linear mixed effects models were used to determine treatment (paternal diet restriction versus control) differences and possible effects of covariates, including sex, litter membership, and litter size. Results Paternal food deprivation resulted in a consistent decrease in average serum glucose in male and female offspring. Significant changes in corticosterone and insulin-like growth factor-1 were found for some groups. The results indicated a male-mediated transgenerational effect on metabolism- and growth-related parameters, in particular glucose. Conclusions Effects of paternal nutritional experiences on offspring metabolism, if confirmed, would be novel and could have far-reaching implications in the context of transgenerational effects on chronic diseases.

The DNA demethylating agent 5-AZA-2′-deoxyxytidine (5-AZA-CdR) alters gene expression in mice exposed during developmental stages and causes malformations and growth suppression. The aim of this study was to determine if 5-AZA-CdR-induced growth retardation is associated with alterations in energy metabolism or in serum IGF-1 levels. Mice were exposed in utero to 5-AZA-CdR at gestation day 10. At postnatal day 21, exposed pups were weaned and body weights recorded. At 3 months of age, reproductive capacity was studied. At 5 months old, after body weight was recorded mice were killed and serum was collected to determine serum glucose, corticosterone, and IGF-1 levels. The body weights of both treated males and females were reduced at weaning compared with controls, but by 5 months of age, only the male body weight was affected. Reproductive capacity of males and females was reduced with males being more affected. Levels of corticosterone and glucose were not altered. Serum IGF-1 levels were lower in males exposed in utero to 5-AZA-CdR when compared to controls, but not in females, and correlated significantly with body weights. Our data suggest that the decreased levels of IGF-1 associated with the treatment could be the cause of the observed growth retardation in the in utero-exposed mice. A gender dimorphic effect, where males are more affected, is evident.

Anti-Mullerian hormone is a peptide growth factor that was first recognized for its effects on sex differentiation in the male fetus.1 In adult women, antiMullerian hormone is produced by granulosa cells and is a marker of ovarian reserve.2 Animal studies indicate that antiMullerian hormone inhibits the recruitment of new follicles from the primordial follicle pool and is involved in regulating the number of growing follicles, and selecting follicles for ovulation.3 Data suggest that women have a fixed ovarian reserve, starting with approximately 1–2 million follicles at birth, after which oocyte numbers decline.4 By menopause, fewer than 1,000 follicles remain.5 This decline in oocytes mirrors a decline in antiMullerian hormone concentration, which peaks sometime during late adolescence or early adulthood, thereafter decreasing until antiMullerian hormone is undetectable among post-menopausal women.6, 7 Anti-Mullerian hormone has been extensively studied among infertile women, and its utility in predicting ovarian response in assisted reproductive technology among this population has been well established.6, 8, 9 Attention has now focused on studying the distribution and determinants of antiMullerian hormone concentrations in the general population. Although there have been recent appeals to investigators to consider the assessment of antiMullerian hormone as a primary outcome measure when examining effects of exposures that may target the ovary,8 few such investigations exist. The aim of the present study was to investigate environmental factors affecting antiMullerian hormone concentrations in reproductive-age women in rural South Africa. Environmental effects on anti-Mullerian hormone are plausible; for example, chemotherapy, radiation, and smoking are known to decrease its concentration.10–14 We were especially interested in the environmental exposure of cooking over open wood fires, due to shared toxic contaminants of cigarette smoke and combustion by-products of biomass fuel burning, and we hypothesized that women who cooked over open wood fires would have lower anti-Mullerian hormone concentrations. Indoor residual spraying for malaria control (using either dichlorodiphenyltrichloroethane [DDT] or pyrethroids) also occurred in some of the study villages. Given the animal studies showing their adverse effects on the ovary,15–18 we hypothesized that exposure to these pesticides would be associated with decreased antiMullerian hormone concentrations. In addition, given the paucity of data on antiMullerian hormone in women other than those seeking treatment at fertility clinics, we also aimed to describe the associations between demographic, lifestyle, and reproductive factors and antiMullerian hormone concentrations in this South African sample.

We investigated the effects of altered endogenous nighttime melatonin concentrations on mammary tumor production in an N-nitroso-N-methylurea (NMU)-induced breast cancer model in female Fischer 344 (F344)/N rats. Experiments were designed 1) to evaluate whether short-duration intermittent exposures to light at night would affect the nocturnal rise of melatonin, resulting in a decrease in nighttime serum melatonin concentrations, 2) to evaluate whether any suppression of nighttime serum melatonin concentrations could be maintained for a period of weeks, and 3) to determine the effects of suppressed serum melatonin concentrations on the incidence and progression of NMU-induced breast cancer. In vivo studies were used to assess serum melatonin concentrations after 1 day and 2 and 10 weeks of nightly administration of short-duration intermittent light exposure at night and incidence of NMU-induced tumors. Five 1-minute exposures to incandescent light every 2 hours after the start of the dark phase of the light: dark cycle decreased the magnitude of the nocturnal rise of serum melatonin concentrations in rats by approximately 65%. After 2 weeks of nightly intermittent light exposures, an average decrease of the peak nighttime serum melatonin concentrations of approximately 35% occurred. The amelioration continued and, at 10 weeks, peak nighttime serum melatonin concentrations were still decreased, by approximately 25%. Because peak endogenous nighttime serum melatonin values could be moderately suppressed for at least 10 weeks, a 26-week NMU mammary tumor study was conducted. Serum melatonin concentrations and incidence, multiplicity, and weight of NMU-induced mammary tumors were assessed. A group of pinealectomized (Px) animals was also included in the tumor study. No effect on the development of mammary tumors in an NMU-induced tumor model in rats occurred when endogenous nighttime serum melatonin concentrations were moderately suppressed by short-duration intermittent light exposures at night. At necropsy, there were no alterations in mammary tumor incidence (28/40 NMU controls, 28/40 NMU + light, 31/40 NMU + Px), multiplicity (2.18 tumors/tumor-bearing NMU control, 1.89 NMU + light, 2.39 NMU + Px), or average tumor weight (1.20 g NMU control, 1.19 g NMU + light, 0.74 g NMU + Px). Tumor burden had no effect on the serum melatonin cycle. At 26 weeks, however, animals exposed to intermittent light at night exhibited approximately 3-fold higher serum melatonin concentrations as compared with controls. Additionally, rats that had been pinealectomized at 4 weeks of age had serum melatonin concentrations that were markedly higher than the expected baseline concentrations for pinealectomized rats (

alpha-Methylstyrene (AMS) is a chemical intermediate used in the synthesis of specialty polymers and copolymers. Inhalation studies of AMS were conducted because of the lack of toxicity data and the structural similarity of AMS to styrene, a toxic and potentially carcinogenic chemical. Male and female B6C3F1 mice were exposed to 0, 600, 800, or 1000 ppm AMS 6 h/day, 5 days/week, for 12 days. After 1 exposure, 21% (5/24) of female mice were found dead in the 1000-ppm group, 56% (10/18) in the 800-ppm group, and 6% (1/18) in the 600-ppm concentration group. After 12 exposures, relative liver weights were significantly increased and relative spleen weights were significantly decreased in both male and female mice at all concentrations. No microscopic treatment-related lesions were observed. A decrease in hepatic glutathione (GSH) was associated with AMS exposure for 1 and 5 days. Male and female F344 rats were exposed to 0, 600 or 1000 ppm AMS for 12 days. No mortality or sedation occurred in AMS-exposed rats. Relative liver weights were significantly increased in both males and females after 12 exposures to 600 or 1000 ppm. An increased hyaline droplet accumulation was detected in male rats in both concentration groups; no significant microscopic lesions were observed in other tissues examined. Exposure of male and female F344 rats and male NBR rats to 0, 125, 250 or 500 ppm AMS, 6 h/day for 9 days resulted in increased accumulation of hyaline droplets in the renal tubules of male F344 rats in the 250 and 500 ppm concentration groups. Although AMS and styrene are structurally very similar, AMS was considerably less toxic for mice and more toxic for male rats than styrene.

Perfluoroalkyl substances (PFAS) are persistent and ubiquitous environmental contaminants, and human exposure to these substances may be related to preeclampsia, a common pregnancy complication. Previous studies have found serum concentrations of PFAS to be positively associated with pregnancy-induced hypertension and preeclampsia in a population with high levels of exposure to perfluorooctanoate. Whether this association exists among pregnant women with background levels of PFAS exposure is unknown. Using data from the Norwegian Mother and Child Cohort Study conducted by the Norwegian Institute of Public Health, we carried out a study of nulliparous pregnant women enrolled in 2003-2007 (466 cases, 510 noncases) to estimate associations between PFAS concentrations and an independently validated diagnosis of preeclampsia. We measured levels of 9 PFAS in maternal plasma extracted midpregnancy; statistical analyses were restricted to 7 PFAS that were quantifiable in more than 50% of samples. In proportional hazards models adjusted for maternal age, prepregnancy body mass index (weight (kg)/height (m)(2)), educational level, and smoking status, we observed no strongly positive associations between PFAS levels and preeclampsia. We found an inverse association between preeclampsia and the highest quartile of perfluoroundecanoic acid concentration relative to the lowest quartile (hazard ratio = 0.55, 95% confidence interval: 0.38, 0.81). Overall, our findings do not support an increased risk of preeclampsia among nulliparous Norwegian women with background levels of PFAS exposure.

Divinylbenzene (DVB) is a crosslinking monomer used primarily for copolymerization with styrene to produce ion-exchange resins. The toxicity of inhaled DVB was investigated because of the potential for worker exposure and the structural similarity of DVB to styrene, a potential carcinogen. Male and female B6C3F1 mice were exposed to 0, 25, 50, or 75 ppm DVB for 6 hr/day, 5 days/week for up to 2 weeks. Six mice/sex/dose group were killed after 3, 5, and 10 exposures and six mice/sex in the 75 ppm group were killed 7 days after 10 exposures. The most severe effects occurred in the nasal cavity and liver, with less severe effects occurring in the kidneys. In the nasal cavity olfactory epithelium acute necrosis and inflammation were present at early time points followed by regeneration, architectural reorganization, and focal respiratory metaplasia by 7 days after the last exposure. Olfactory epithelial changes were concentration-dependent with extensive involvement at 75 ppm and peripheral sparing at 25 ppm. There was also necrosis and regeneration of olfactory-associated Bowman's glands as well as the lateral nasal (Steno's) glands. Hepatocellular centrilobular (CL) necrosis was observed only in the 75 ppm dose group and was similar to that caused by styrene. A time-dependent progression was observed, characterized by CL degeneration after 1 exposure, necrosis after 3 and 5 exposures, and chronic inflammation with CL karyomegaly after 10 exposures and 7 days after the 10th exposure. Hepatic GSH levels were decreased in a dose-dependent manner. In the kidneys, transient tubular damage was observed in some male mice exposed to 75 ppm, and appeared to be a response to DVB-induced tubular epithelial injury.

Previous studies from our laboratory found that when boric acid (BA) was administered in the diet to rats, boron levels in bone were approximately fourfold greater than serum levels. The current studies were undertaken to determine if these elevations produced adverse effects on several bone-related measures, including serum electrolyte levels, bone structure, and bone strength. Data from two studies are presented: in the first study, young adult male rats consumed a powdered diet containing 0, 3000, 4500, 6000, or 9000 ppm BA for 9 weeks. Endpoints were serum calcium, phosphorous, potassium, and chloride, as well as blood and bone boron concentrations ([B]) measured weekly during the 9-week exposure period, and at 8, 16, 24, and 32 weeks after the end of exposure. In the second study, the male and female young adult rats diet contained 0, 200, 1000, 3000, or 9000 ppm BA for 12 weeks; endpoints measured weekly were serum levels of calcium, phosphorous, and magnesium, bone [B], and bone structure (humerus) and strength (tibia, femur, and lumbar vertebrae). In treated rats, calcium was reduced in the first study but not the second. Serum phosphorous was reduced in both studies; potassium was unchanged, chloride was increased by 1%, and magnesium was reduced in all BA-exposed groups in the second study, to a maximal 19% reduction. Bone [B] was consistently increased in all treated groups, to concentrations approximately fourfold those of serum. After cessation of exposure, serum and urinary boron concentrations dropped to within control values within a week. However, even 32 weeks after the end of exposure, bone [B] remained threefold greater than controls. Male tibia and femur resistance to bending was unchanged. However, vertebral strength in compression was significantly increased by 5-10% in all dose groups (200 to 9000 ppm). The pattern was substantially similar in females. Only the humerus was examined by light microscopy and was found to be unchanged at any level of BA consumption. These data show that, despite a reduction in some serum electrolyte levels, BA consumption increased vertebral resistance to crush force, without detectably altering the microscopic structure of the humerus or the resistance of femur and tibia to a bending load. This increase in compression resistance occurred at exposure levels substantially below those that were previously reported to be reproductively toxic.

Background/Aims: Determinants of internal exposure to DDT and DDE among people who live in homes sprayed with DDT for malaria control have been little-studied. Methods: This analysis includes 383 w...

Background: Few studies have examined predictors of DDT (dichlorodiphenyltrichloroethane) and DDE (dichlorodiphenyldichloroethylene) levels among residents in homes sprayed with DDT for malaria control with the aim of identifying exposure-reduction strategies. Methods: The present analysis included 381 women enrolled in the Study of Women and Babies (SOWB) during 2010–2011, from eight South African villages in the Limpopo Province, South Africa. Indoor residual spraying (IRS) occurred in half of the villages. Questionnaires regarding various demographic and medical factors were administered and blood samples were obtained. We classified the women into three exposure groups by type of residence: unsprayed village (n = 175), IRS village in household with a low likelihood of DDT use (non-DDT IRS household, n = 106), IRS village in household with a high likelihood of DDT use (DDT IRS household, n = 100). We used multivariable models of natural log-transformed DDT plasma levels (in micrograms per liter) and DDE (in micrograms per liter) to identify predictors for each group. Results: Median levels of DDT and DDE among women in unsprayed villages were 0.3 [interquartile range (IQR): 0.1–0.9] and 1.7 (IQR: 0.7–5.5), respectively. Median levels of DDT and DDE among women in DDT IRS households were 2.6 (IQR: 1.1–6.6) and 8.5 (IQR: 4.7–18.0), respectively. In unsprayed villages, women with water piped to the yard, rather than a public tap, had 73% lower DDT (95% CI: –83, –57%) and 61% lower DDE (95% CI: –74, –40%) levels. In DDT IRS households, women who reported taking more than six actions to prepare their home before IRS (e.g., covering water and food) had 40% lower DDT levels (95% CI: –63, –0.3%) than women who took fewer than four actions. Conclusion: The predictors of DDT and DDE plasma levels identified in the present study may inform interventions aimed at decreasing exposure. Among households where DDT is likely to be used for IRS, education regarding home preparations may provide an interventional target. Citation: Whitworth KW, Bornman RM, Archer JI, Kudumu MO, Travlos GS, Wilson RE, Longnecker MP. 2014. Predictors of plasma DDT and DDE concentrations among women exposed to indoor residual spraying for malaria control in the South African Study of Women and Babies (SOWB). Environ Health Perspect 122:545–552; http://dx.doi.org/10.1289/ehp.1307025

Acute toxicity studies were conducted on copper gallium diselenide (CGS), copper indium diselenide (CIS), and cadmium telluride (CT), three novel compounds used in the photovoltaic and semiconductor industries. Female Sprague-Dawley rats (six rats/dose) were administered 0, 12, 25, 50, or 100 mg/kg body wt of CGS, CIS, or CT by intratracheal instillation. At 72 hr after treatment, body weight gain was significantly decreased in the 100 mg/kg CIS group and in all CT dose groups. Lung weights were increased in most chemical-treated rats, with CT causing the greatest increase. Total numbers of cells in bronchoalveolar lavage fluid (BALF) were significantly increased in treated rats and were greatest in the 100 mg/kg CIS group. Differential cell counts of BALF demonstrated a marked decrease in the percentage of alveolar macrophages and an increase in the percentage of polymorphonuclear leukocytes in all dose groups of all three chemicals. Slight to moderate increases in lactate dehydrogenase activity were observed in BALF from CGS- and CIS-treated rats; marked increases were observed in CT-treated rats. BALF protein was significantly increased in rats treated with CIS and CT. Microscopic examination revealed lymphoid hyperplasia in lungs of rats treated with all three chemicals. CT caused necrosis of the terminal bronchiolar epithelium and epithelium of the alveolar duct region with inflammation, prominent fibrin exudates, and type II cell hyperplasia. CGS and CIS also caused intraalveolar inflammation and type II cell hyperplasia, but did not cause the necrosis and fibrin exudate observed in lungs of CT-treated rats. Based on changes in lung weight, BALF indices, and histopathology, CT was the most toxic for the lung; CIS had intermediate toxicity and CGS was the least toxic. The solubilities of CGS and CIS were relatively low and similar at both pH levels and do not readily explain the observed differences in pulmonary toxicity. The solubility of CdTe was considerably greater than that of CGS and CIS and likely contributed to the greater toxicity of this compound.

Acetaminophen (APAP) intoxication has been shown to activate Kupffer cells. Kupffer cell activation is also associated with the release of proinflammatory cytokines which can induce a variety of pathophysiological responses. These studies examined whether proinflammatory cytokines are produced in response to a hepatotoxic dose of APAP, and if so, the role they play in the observed pathological response. Female B6C3F1 mice received 500 mg APAP/kg in the presence and absence of antibodies against tumor necrosis factor-alpha (TNF-alpha), interleukin-1-alpha (IL-1 alpha), and IL-1 receptor antagonist (IL-1ra). Serum TNF-alpha, IL-1 alpha, and liver-associated enzyme levels were measured. In addition, the levels of mRNA transcripts for IL-1 alpha, IL-6, and TNF-alpha from livers of treated mice were examined by reverse transcription-polymerase chain reaction (RT-PCR). Administration of APAP resulted in an immediate reduction in body temperature as well as elevated serum levels of IL-1 alpha and TNF-alpha that reached a peak at 12 and 16 hr, respectively. The reduction in body temperature was partially blocked by injection of antibodies against TNF-alpha or IL-1 alpha. Furthermore, neutralization of TNF-alpha delayed the increase in serum IL-1 alpha and liver enzyme levels. In contrast, pretreatment with IL-1ra antisera exacerbated the effect of APAP on body temperature and increased the release of liver enzymes. These data suggest that TNF-alpha and IL-1 alpha are released in response to APAP intoxication and are responsible for certain pathological manifestations of APAP-induced hepatotoxicity.

Inhalation exposure to styrene at concentrations that cause metabolic saturation results in significantly greater hepatotoxicity in B6C3F1 mice than in Swiss mice; females of both strains are more susceptible than males. These studies were conducted to investigate the mouse strain and gender differences in susceptibility to hepatotoxicity caused by repeated exposure to styrene at concentrations that do not cause metabolic saturation. Male and female B6C3F1 and Swiss mice (8 weeks old) were exposed to 0, 150, or 200 ppm styrene for 6 hr/day, 5 days/week, for up to 2 weeks. Changes in body and liver weights, serum alanine aminotransferase (ALT) and sorbitol dehydrogenase (SDH) levels, liver histopathology, and total liver glutathione (GSH) were evaluated after 2, 3, 5, and 10 exposures (six mice/sex/strain/time point/concentration). Blood levels of styrene and styrene-7,8-oxide (SO) were measured in mice exposed to 200 ppm styrene for 2,3, or 5 days (six mice/sex/strain/time point/concentration). Serum ALT and SDH levels were significantly elevated only in female B6C3F1 mice after 3 exposures to 200 ppm styrene; enzyme levels had returned to control levels when measured after 5 and 10 exposures. Degeneration and coagulative necrosis of centrilobular hepatocytes were observed in female B6C3F1 mice exposed 2, 3, and 5 days to 150 or 200 ppm styrene; incidences of these lesions were greater in the 200 ppm than in the 150 ppm dose group. After 10 days of exposure to 150 or 200 ppm styrene, hepatocellular lesions had resolved, although a residual chronic inflammation was present in livers of most female B6C3F1 mice.(ABSTRACT TRUNCATED AT 250 WORDS)

Because of the potential increased use of phosphine (PH3) as a fumigant and the lack of adequate toxicity data, short-term inhalation studies were conducted to characterize the toxicity of PH3 for Fischer 344 (F344) rats and B6C3F1 mice. Male rats and mice were exposed to 0, 1, 5, or 10 ppm PH3 for up to 4 days, and males and females to 0, 1.25, 2.5, or 5 ppm for 2 wk. In the 4-day study, all rats died by the end of the third exposure to 10 ppm, and all mice were euthanized in moribund condition after the fourth exposure to 10 ppm. Clinical pathology data were obtained only for mice, due to early mortality of rats. There were no significant treatment-related effects in hematological indices in mice exposed to 1 or 5 ppm; at 10 ppm there was a moderate anemia, and leukocyte counts were significantly decreased. There were significant biologically relevant increases in serum activity of alanine aminotransferase (ALT) and sorbitol dehydrogenase (SDH) and in the concentration of urine nitrogen (UN) at ...

Background: Recent findings suggest that maternal smoking during pregnancy may play a role in the development of metabolic alterations in offspring during childhood. However, whether such exposure increases the risk of developing similar metabolic alterations during adulthood is uncertain. Objective: We evaluated the association of in utero exposure to maternal tobacco smoke with plasma lipids, apolipoprotein B (apoB), and C-reactive protein (CRP) in adulthood. Methods: The study was based on a subsample of the Norwegian Mother and Child Cohort Study (MoBa) and included 479 pregnant women with plasma lipids, apoB, and CRP measurements. Information on in utero exposure to tobacco smoke, personal smoking, and other factors were obtained from the women by a self-completed questionnaire at enrollment, at approximately 17 weeks of gestation. Results: Women exposed to tobacco smoke in utero had higher triglycerides [10.7% higher; 95% confidence interval (CI): 3.9, 17.9] and lower high-density lipoprotein cholesterol (HDL) (–1.9 mg/dL; 95% CI: –4.3, 0.5) compared with unexposed women, after adjusting for age, physical activity, education, personal smoking, and current body mass index (BMI). Exposed women were also more likely to have triglycerides ≥ 200 mg/dL [adjusted odds ratio (aOR) = 2.5; 95% CI: 1.3, 5.1] and HDL < 50 mg/dL (aOR = 2.3; 95% CI: 1.1, 5.0). Low-density lipoprotein cholesterol, total cholesterol, and apoB were not associated with the exposure. CRP was increased among exposed women; however, after adjustment for BMI, the association was completely attenuated. Conclusions: In this population, in utero exposure to tobacco smoke was associated with high triglycerides and low HDL in adulthood, 18–44 years after exposure. publishedVersion

Both gene methylation changes and genetic instability have been noted in offspring of male rodents exposed to radiation or chemicals, but few specific gene targets have been established. Previously, we identified the gene for ribosomal RNA, rDNA, as showing methylation change in sperm of mice treated with the preconceptional carcinogen, chromium(III) chloride. rDNA is a critical cell growth regulator. Here, we investigated the effects of paternal treatments on rDNA in offspring tissue. A total of 93 litters and 758 offspring were obtained, permitting rigorous mixed-effects models statistical analysis of the results. We show that the offspring of male mice treated with Cr(III) presented increased methylation in a promoter sequence of the rDNA gene, specifically in lung. Furthermore polymorphic variants of the multi-copy rDNA genes displayed altered frequencies indicative of structural changes, as a function of both tissue type and paternal treatments. Organismal effects also occurred: some groups of offspring of male mice treated with either Cr(III) or its vehicle, acidic saline, compared with those of untreated mice, had altered average body and liver weights and levels of serum glucose and leptin. Males treated directly with Cr(III) or acidic saline presented serum hormone changes consistent with a stress response. These results establish for the first time epigenetic and genetic instability effects in a gene of central physiological importance, in offspring of male mice exposed preconceptionally to chemicals, possibly related to a stress response in these males.

Perfluorooctane sulfonate and perfluorooctanoic acid are perfluorinated compounds (PFCs) widely distributed in the environment. Previous studies of PFCs and birth weight are equivocal. The authors examined this association in the Norwegian Mother and Child Cohort Study (MoBa), using data from 901 women enrolled from 2003 to 2004 and selected for a prior case-based study of PFCs and subfecundity. Maternal plasma samples were obtained around 17 weeks of gestation. Outcomes included birth weight z scores, preterm birth, small for gestational age, and large for gestational age. The adjusted birth weight z scores were slightly lower among infants born to mothers in the highest quartiles of PFCs compared with infants born to mothers in the lowest quartiles: for perfluorooctane sulfonate, β = −0.18 (95% confidence interval: −0.41, 0.05) and, for perfluorooctanoic acid, β = −0.21 (95% confidence interval: −0.45, 0.04). No clear evidence of an association with small for gestational age or large for gestational age was observed. Perfluorooctane sulfonate and perfluorooctanoic acid were each associated with decreased adjusted odds of preterm birth, although the cell counts were small. Whether some of the associations suggested by these findings may be due to a noncausal pharmacokinetic mechanism remains unclear.

Background—Insulin-like growth factor–I (IGF-I) and insulin stimulate cell proliferation in uterine leiomyoma (fibroid) tissue. We hypothesized that circulating levels of these proteins would be associated with increased prevalence and size of uterine fibroids. Methods—Participants were 35–49-year-old, randomly selected members of an urban health plan who were enrolled in 1996–1999. Premenopausal participants were screened for fibroids with ultrasound. Fasting blood samples were collected. Associations between fibroids and diabetes, plasma IGF-I, IGF binding protein 3 (BP3), and insulin were evaluated for blacks (n = 585) and whites (n = 403) by using multiple logistic regression. Results—IGF-I showed no association with fibroids in blacks, but in whites the adjusted odds ratios (aORs) for both mid and upper tertiles compared with the lowest tertile were 0.6 (95% confidence intervals [CI] = 0.3–1.0 and 0.4–1.1, respectively). Insulin and diabetes both tended to be inversely associated with fibroids in blacks. The insulin association was with large fibroids; aOR for the upper insulin tertile relative to the lowest was 0.4 (0.2–0.9). The aOR for diabetes was 0.5 (0.2–1.0). Associations of insulin and diabetes with fibroids were weak for whites. BP3 showed no association with fibroids. Conclusions—Contrary to our hypothesis, high circulating IGF-I and insulin were not related to increased fibroid prevalence. Instead, there was suggestion of the opposite. The inverse association with diabetes, although based on small numbers, is consistent with previously reported findings. Future studies might investigate vascular dysfunction as a mediator between hyperinsulinemia or diabetes and possible reduced risk of fibroids.

Orally active dual mu-/delta-opioid receptor antagonist, H-Dmt-Tic-Lys-NH-CH(2)-Ph (MZ-2) was applied to study body weight gain, fat content, bone mineral density, serum insulin, cholesterol and glucose levels in female ob/ob (B6.V-Lepob/J homozygous) and lean wild mice with or without voluntary exercise on wheels for three weeks, and during a two week post-treatment period under the same conditions. MZ-2 (10mg/kg/day, p.o.) exhibited the following actions: (1) reduced body weight gain in sedentary obese mice that persisted beyond the treatment period without effect on lean mice; (2) stimulated voluntary running on exercise wheels of both groups of mice; (3) decreased fat content, enhanced bone mineral density (BMD), and decreased serum insulin and glucose levels in obese mice; and (4) MZ-2 (30 microM) increased BMD in human osteoblast cells (MG-63) comparable to naltrexone, while morphine inhibited mineral nodule formation. Thus, MZ-2 has potential application in the clinical management of obesity, insulin and glucose levels, and the amelioration of osteoporosis.

Background: Insulin-like growth factor I (IGF-I) stimulates cell proliferation and inhibits apoptosis in the lung and other tissues by interacting with the IGF-I receptor. The major binding protein for IGF-I, insulin-like growth factor-binding protein 3 (IGFBP-3), modulates the effects of IGF-I but also inhibits cell growth and induces apoptosis independent of IGF-I and its receptor. In a prospective study of men in Shanghai, China, we examined the association between serum levels of IGF-I and IGFBP-3 and the subsequent risk of lung cancer. Methods: From 1986 to 1989, serum was collected from 18 244 men aged 45–64 years living in Shanghai without a history of cancer. We analyzed IGF-I and IGFBP-3 levels in serum from 230 case patients who developed incident lung cancer during follow-up and from 740 control subjects. Results: Among 230 case patients and 659 matched control subjects, increased IGF-I levels were not associated with increased risk of lung cancer. However, for subjects in the highest quartile relative to the lowest quartile of IGFBP-3, the odds ratio (OR) for lung cancer, adjusted for smoking and IGF-I, was 0.50 (95% confidence interval [CI] = 0.25 to 1.02). When the analysis was restricted to ever smokers (184 case patients and 344 matched control subjects), the OR for lung cancer in men in the highest quartile of IGFBP-3 relative to those in the lowest quartile, adjusted for smoking and IGF-I, was 0.41 (95% CI = 0.18 to 0.92). Conclusions: In this prospective study of Chinese men, higher serum levels of IGF-I did not increase the risk of lung cancer. However, subjects with higher serum levels of IGFBP-3 were at reduced risk of lung cancer. This finding is consistent with experimental data that indicate that IGFBP-3 can inhibit cellular proliferation and induce apoptosis independent of IGF-I and the IGF-I receptor. [J Natl Cancer Inst 2002;94: 749–54]

Sorbitol dehydrogenase (SDH) is a liver-specific enzyme sensitive to the detection of acute hepatocellular injury in rats; however, its usefulness has been questioned as being a highly labile enzyme. The purpose of this study was to determine the stability of serum and plasma SDH activity from both untreated rats and those treated with a single low dose injection of D-(þ)-galactosamine hydrochloride, a known hepatotoxicant. After collection and initial SDH activity analysis, aliquots of serum and plasma were stored at 21 C, 4 C, and 80 C and analyzed at various time points. Serum SDH activity was stable for 4 hr at 21 C. At 4 C, serum SDH activity was stable for 24 hr, after which it significantly increased; it was not stable at 80 C. Plasma SDH activity was significantly increased by 4 hr at 21 C and 4 C, and by 48 hr at 80 C. Analysis of plasma SDH activity should occur shortly after blood collection. Analysis of serum SDH activity should occur within 4 hr of collection or stored at 4 C and measured within 24 hr. Extended storage at 4 C or 80 C for the measurement of serum or plasma SDH activity cannot be recommended due to the observed substantial elevations in SDH activity.

The National Toxicology Program is conducting a chemical class study to investigate the structure-activity relationships for the toxicity of alpha,beta-unsaturated ketones. Ethyl vinyl ketone (EVK) was selected for study because it is a representative straight-chain aliphatic alpha,beta-unsaturated ketone with extensive use and widespread exposure. Short-term inhalation studies of EVK were conducted to provide toxicity data for comparison with the related alpha,beta-unsaturated ketones 2-cyclohexene-1-one (CHX) and methyl vinyl ketone (MVK). These data will be used in designing chronic toxicity and carcinogenicity studies of these ketones. Male and female F344 rats and B6C3F1 mice were exposed to 0, 2, 4, or 8 ppm EVK 6 h/day, 5 days/wk for 13 wk. The nasal cavity was the major target organ of EVK in both rats and mice. Pathologic findings in both the olfactory and respiratory epithelium were observed. Lesions consisted primarily of olfactory epithelial necrosis, atrophy and regeneration, and/or hyperplasia and squamous metaplasia of the respiratory epithelium. Squamous metaplasia of the respiratory epithelium was present in all rats and mice exposed to 4 and 8 ppm EVK, and these lesions were more severe in rats than in mice. Few systemic effects were observed in rats and mice exposed to EVK. A transient decrease in total leukocytes due to decrements in lymphocyte and monocyte populations was present in male rats after exposure to 8 ppm for 3 and 21 days; however, this effect was not present after exposure for 13 wk. There were no chemical-related effects on micronucleus formation in mice, or on sperm motility and vaginal cytology in either species. EVK, like other alpha,beta-unsaturated ketones, is a reactive, direct-acting gaseous irritant with toxicity limited primarily to the upper respiratory tract.

The National Toxicology Program is conducting a chemical class study to investigate the structure-activity relationships for the toxicity of alpha,beta-unsaturated ketones. Methylvinyl ketone (MVK) was selected for study because it is a representative straight-chain aliphatic alpha,beta-unsaturated ketone and because of its extensive use and widespread exposure. Short-term inhalation studies of MVK were conducted to provide toxicity data for comparison with other alpha,beta-unsaturated ketones and for use in designing chronic toxicity and carcinogenicity studies. In 2-week studies, rats and mice were exposed to 0, 0.25, 0.5, 1, 2, 4, or 8 ppm MVK 6 h/day, 5 days/week for 12 exposures. Morbidity and early deaths occurred in all male and female rats after 1 exposure and in 2 male mice after 10 exposures to 8 ppm. Rats exhibited nasal cavity toxicity and lung necrosis at 4 ppm. No toxicity was observed in animals exposed to less than 2 ppm. Based on these results a 13-week study was conducted at 0, 0.5, 1, and 2 ppm MVK. As observed in the 2-week study, the nasal cavity was the main target organ and rats were more sensitive than mice. Respiratory and olfactory epithelial necrosis were prominent by day 21 in the rat. At study termination these lesions were still evident but not as severe as noted earlier. Additionally, changes such as olfactory epithelial regeneration and metaplasia (respiratory) as well as respiratory epithelial hyperplasia and metaplasia (squamous) were clearly evident. Nasal lesions in mice were limited to a subtle squamous metaplasia of transitional and/or respiratory epithelium covering predominantly the tips of naso- and maxilloturbinates in Levels I and II. A transient, leukopenia was observed in rats exposed to 2 ppm, however, this effect was not present after 13 weeks of exposure. In mice, leukocyte counts were significantly decreased at all exposure concentrations after 13 weeks of exposure. Absolute testicular and epididymal weights and sperm counts were decreased at the high dose only. MVK can be characterized as a reactive, direct-acting gaseous irritant. MVK exposure causes the same nasal cavity lesions as the cyclic alpha,beta-unsaturated ketone, 2-cyclohexen-1-one, although at lower exposure concentrations.

Copper gallium diselenide (CGS), copper indium diselenide (CIS), and cadmium telluride (CdTe) are novel compounds used in the photovoltaic and semiconductor industries. This study was conducted to characterize the relative toxicities of these compounds and to evaluate the pulmonary absorption and distribution after intratracheal instillation. Female Sprague–Dawley rats were administered a single equimolar dose (70 m m ) of CGS (21 mg/kg), CIS (24 mg/kg), CdTe (17 mg/kg), or saline by intratracheal instillation. Bronchoalveolar lavage fluid (BALF) protein, fibronectin, inflammatory cells, lung hydroxyproline, and tissue distribution were measured 1, 3, 7, 14, and 28 days after instillation. Relative lung weights were significantly increased in CIS- and CdTe-treated rats at most time points. Inflammatory lesions in the lungs consisting of an influx of macrophages, lymphocytes, and PMNs were most severe in CdTe-treated rats, intermediate in CIS-treated rats, and minimal in rats receiving CGS. Hyperplasia of alveolar type 2 cells was present in CIS- and CdTe-treated rats and was greatest in CdTe-treated rats. Pulmonary interstitial fibrosis was observed in CdTe-treated rats at all time points. All three compounds caused marked increases in total BALF cell numbers, with the greatest increase observed in CIS-treated rats. BALF protein, fibronectin, and lung hydroxyproline were significantly increased in all treated animals and were highest in CdTe-treated animals. There was no apparent pulmonary absorption or tissue distribution of CGS. Indium levels increased in extrapulmonary tissues of CIS-treated rats, although Cu and Se levels remained unchanged. CdTe was absorbed from the lung to a greater extent than CGS and CIS. Cd and Te levels decreased in the lung and increased in extrapulmonary tissues. Of these compounds CdTe presents the greatest potential health risk because it causes severe pulmonary inflammation and fibrosis and because it is readily absorbed from the lung may potentially cause extrapulmonary toxicity.

In order to address data gaps identified by the NAS report Pesticides in the Diets of Infants and Children, a study was performed using methoxychlor (MXC). Female rats were gavaged with MXC at 0, 5, 50, or 150 mg/kg/day for the week before and the week after birth, whereupon the pups were directly dosed with MXC from postnatal day (pnd) 7. Some dams were killed pnd7 and milk and plasma were assayed for MXC and metabolites. For one cohort of juveniles, treatment stopped at pnd21; a modified functional observational battery was used to assess neurobehavioral changes. Other cohorts of juveniles were dosed until pnd42 and evaluated for changes to the immune system and for reproductive toxicity. Dose-dependent amounts of MXC and metabolites were present in milk and plasma of dams and pups. The high dose of MXC reduced litter size by approximately 17%. Ano-genital distance was unchanged, although vaginal opening was accelerated in all treated groups, and male prepuce separation was delayed at the middle and high doses by 8 and 34 days, respectively. In the neurobehavioral evaluation, high-dose males were more excitable, but other changes were inconsistent and insubstantial. A decrease in the antibody plaque-forming cell response was seen in males only. Adult estrous cyclicity was disrupted at 50 and 150 MXC, doses which also showed reduced rates of pregnancy and delivery. Uterine weights (corrected for pregnancy) were reduced in all treated pregnant females. High-dose males impregnated fewer untreated females; epididymal sperm count and testis weight were reduced at the high, or top two, doses, respectively. All groups of treated females showed uterine dysplasias and less mammary alveolar development; estrous levels of follicle stimulating hormone were lower in all treated groups, and estrus progesterone levels were lower at 50 and 150 MXC, attributed to fewer corpora lutea secondary to ovulation defects. These data collectively show that the primary adult effects of early exposure to MXC are reproductive, show that 5 mg/kg/day is not a NO(A)EL in rats with this exposure paradigm (based on changes in day of vaginal opening, pubertal ovary weights, adult uterine and seminal vesicle weights, and female hormone data) and imply that the sites of action are both central and peripheral.

These studies define the site and mechanisms of reproductive toxicity of ethylene glycol monomethyl ether (EGME) in a nongravid female animal model using in vivo and in vitro methods. In vivo studies assessed vaginal cytology and histology, ovarian histology, and serum hormones in 80- to 90-day-old, adult, regularly cycling, female Sprague-Dawley rats treated daily with EGME or vehicle by oral gavage. Dose-response and time-course studies (four to nine rats per group per treatment) determined that 300 mg/kg EGME suppressed cyclicity without systemic toxicity within 3 to 8 days, and doses less than 100 mg/kg had no effect. Pathogenesis studies (six to nine rats per time and treatment) determined that 300 mg/kg EGME elevated serum progesterone within 32 hr after dosing, while serum estradiol, FSH, LH, and prolactin remained at baseline levels. In EGME-treated rats, cyclicity was suppressed, ovulation was inhibited, and corpora lutea were hypertrophied. Thus, EGME appeared to target the ovarian luteal cell. To further examine the toxicity in vitro, luteal cells were recovered from 23-day-old, hCG-primed Sprague-Dawley rats and treated with 0-10 mM methoxy acetic acid (MAA), the proximate toxic metabolite of EGME. MAA (1-10 mM) maintained elevated progesterone levels as production declined in untreated cells at 24 and 48 hr of culture. Progesterone production was maintained independent of LH-stimulated cAMP levels. MAA decreased ATP, but only at 48 hr and at 2.5 mM or greater concentrations. Thus, these studies establish that the ovarian luteal cell is a target of EGME and MAA in vivo and in vitro and that the effect on luteal cell progesterone production is likely independent of LH-stimulated cAMP pathways.

Administration of 500 mg/kg acetaminophen (APAP) to female B6C3F1 mice resulted in well-documented pathophysiological changes in the liver manifested as increased serum concentration of liver enzymes (aspartate aminotransferase, alanine aminotransferase, lactate dehydrogenase, and serum sorbitol dehydrogenase), centrilobular congestion, and hepatocellular degeneration and necrosis. The role of proinflammatory cytokines, including tumor necrosis factor alpha (TNF-alpha) and interleukin 1 alpha (IL-1 alpha), on the hepatotoxicity of APAP was examined at 4, 8, 12, and 24 hr following APAP administration. Neutralization of TNF-alpha or IL-1 alpha with specific antibodies partially prevented the hepatotoxic effects of APAP at the 4- and 8-hr time points. In addition, prior administration of anti-TNF-alpha antibodies shortened the recovery time following APAP treatment. While IL-1 receptor antagonist (IL-1ra) had only a modest protective effect against APAP-induced liver damage, as determined by serum enzyme release, IL-1ra had no effect on the degree of hepatic congestion or necrosis at any of the time points examined. On the other hand, administration of antibodies against IL-1ra exacerbated APAP-induced liver toxicity. These results suggest that TNF-alpha and IL-1 alpha play an important role in the degree of damage and recovery that the liver undergoes following APAP intoxication.

Environmental and dietary factors modify genomes and phenotypes. The extents of these modifications are not clear. DNA methylation and genotypes of the multi-copy 45S rRNA gene were quantified in 4 tissues at 3 developmental stages (sperm of 128 treated males, 98 litters of 876 day-8 embryos, and lung, liver, and a subset of sperm from 93 litters of 758 6-week adult offspring) in 3 treatment groups. Mixed models for adjusting confounding factors were used for all statistical analyses. Single injections of 1 mmol/kg chromium(III), [Cr(III)], an environmental agent and a dietary supplement, or acid saline (AS) vehicle were given to male mice only, which were then euthanized or bred 2 weeks later. A trend toward hypomethylation in the rRNA spacer promoter region but no frequency differences in 5 sequence variants of the rRNA, defined by 4 single nucleotide polymorphisms, were observed in sperm 2 weeks after Cr(III) treatment as compared to AS and untreated (UT) groups. This epigenetic trend disappeared at the day-8 embryo stage for both genders after paternal treatments with Cr(III) and/or AS. In offspring at 6 weeks of age, significant hypermethylation of the rRNA spacer-promoter was detected in the lung of the male offspring from Cr(III)-treated fathers, reversing the hypomethylation trend seen in the sperm 2 weeks after Cr(III) treatment. There was also a change in genotype: a significant reduction of the rRNA CGC variant in Cr(III) and/or AS groups in lung and liver in males, and in lung in females. Further examinations of the regressions of individual sequence variants on DNA methylation and on other variants revealed significant modifications to those correlates by Cr(III) and/or AS but to different degrees depending on the developmental stages, thus supporting the hypothesis of paternal exposure-induced epigenetic and genetic reprogramming. These genomic reprogrammings were accompanied by phenotypic changes related to paternal Cr(III) or AS treatment, including increased body and liver weights and alterations in serum glucose and leptin. Male mice treated with either Cr(III) or AS demonstrated a typical chemical stress response, as indicated by acute reduction in serum insulin and leptin, followed later by increases in these hormones. Taken together, this multi-faceted cross-generational study uncovers modifiable epigenetic and genetic reprogramming during development and differentiation. Paternal stress apparently had multiple effects on genomes and phenotypes, in their offspring. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 184.

Experimental evidence suggests that the oxidative metabolites 2,3- and 2,5-dihydroxybenzoic acid (DIOH) may be responsible for the nephrotoxicity of salicylic acid (SAL). In the present study, enzymuria in conjunction with glucose (GLU) and protein (PRO) excretion were used as endpoints to compare the relative nephrotoxicity of SAL with 2,3- and 2,5-DIOH. In addition, the effect of age on enzymuria and GLU and PRO excretion following treatment with SAL or 2,3- and 2,5-DIOH was investigated because the elderly are at greater risk for SAL-induced nephrotoxicity. Three and 12-month male Fischer 344 rats were administered either no treatment, vehicle, SAL, 2,3-DIOH, or 2,5-DIOH at 500 mg/kg p.o. in 5 ml/kg corn oil/DMSO (5:1). Effects of these treatments on functional integrity of renal tissue was assessed from 0--72 h after dosing by measurement of urinary creatinine, GLU, and PRO, as well as excretion of proximal and distal tubular renal enzymes. Enzymes measured as indicators of proximal tubular damage were N-acetyl-beta-glucosaminidase (NAG), gamma glutamyltransferase (GGT), alanine aminotransferase (ALT), and alkaline phosphatase (AP), while urinary lactate dehydrogenase (LD) and aspartate aminotransferase (AST) were measured as indicators of distal tubular damage. In comparison to 3-month vehicle-treated rats, 2,3- and 2,5-DIOH caused a significant increase between 0-8 h in excretion of urinary GLU and activities of AST, NAG, and LD, with peak effects occurring between 4-8 h. Toxic effects of either metabolite were not evident beyond 24 h, and toxicity of 2,5-DIOH was significantly greater in comparison to 2,3-DIOH. SAL treatment resulted in similar effects on enzymuria as well as GLU and PRO excretion, but peak effects did not occur until 16-24 h, and often persisted until 72 h after dosing. Maximal enzymuria in response to SAL treatment was significantly greater in 12- vs. 3-month rats for AST, NAG, and LD. In response to 2,3-DIOH treatment, the maximal response was significantly greater in 12- vs. 3-month rats for LD and AST, and for NAG in response to 2,5-DIOH treatment. The results of this study suggest that both 2,3- and 2,5-DIOH are nephrotoxic metabolites of SAL, but implicate 2,5-DIOH as the more potent nephrotoxic metabolite. The relative lack of an age effect for 2,3- and 2,5-DIOH vs. SAL supports the hypothesis [2] that age-related differences in biotransformation of SAL, and not increased tissue sensitivity to 2,3- or 2,5-DIOH, contribute to the age-related increase in susceptibility to SAL-induced nephrotoxicity.

Clinical pathology data can significantly contribute to the characterization of a disease process if suitable time points for sample collection are chosen and combined with the measurement of biochemical analytes that are sensitive and specific for damage to a potential target organ. Using a well-defined model for hepatotoxicity, we correlated histopathological lesions in the liver with changes in selected serum analytes. Groups of Fischer-344 rats were treated with carbon tetrachloride (280 mg/kg in corn oil) for 1, 2, 4, 6, 8 or 10 days. Subgroups were allowed to recover for 1, 5 or 8 days, at which time blood and liver specimens were collected. Histologically, necrosis was detected in livers from rats treated for 1 and 2 days and allowed to recover for 1 day. This was followed by generalized fatty change in animals treated for longer periods. The maximum severity of fatty change occurred 7–12 days (total experimental time). A sharp rise and fall (48 h) in cytosolic enzyme activities were seen in serum. This preceded gradual increases in all analytes measured which eventually peaked at 9–11 days (total experimental time). The pattern seen in biochemical analytes paralleled the development of marked fatty change. We discuss relationships between the histologic and biochemical findings and conclude that appropriate clinical biochemistry measurements in a toxicology experiment can provide valuable mechanistic information.

In animals and human beings exposed to arsine gas (AsH3) a severe and fulminant lysis of erythrocytes occurs. Little is known about the effects of subchronic exposure on the hematopoietic system or about the mechanism of hemolysis produced by arsine gas. To examine these, we exposed male and female mice to 0.000, 0.025, 0.500 and 2.500 ppm arsine gas for 6 h a day, 5 days a week during a 90-day period. After 5, 15, and 90 days of exposure, blood was collected and routine hematologic profiles were performed to document the effects of arsine gas on peripheral blood. A moderate hemolytic anemia, indicated by decreases in erythrocyte counts, hematocrits, hemoglobin concentrations and increases in mean corpuscular hemoglobins and mean corpuscular hemoglobin concentrations, was seen in blood samples collected after 5 days of exposure. In blood collected after 15 and 90 days of exposure, the anemia was less severe but a greater increase in mean corpuscular volumes and absolute reticulocyte counts revealed an active regenerative response. Higher concentrations of methemoglobin in animals in the 2.500 ppm exposure group (measured after 90 days of exposure) indicated that the rate of oxidation of heme (ferrous to ferric) increased due to exposure to arsine gas. Additionally, the presence of Heinz bodies in blood smears stained with brilliant cresyl blue and decreases in reduced glutathione concentrations in red blood cells exposed to arsine gas in vitro provide evidence that the mechanism of hemolysis involves depletion of intracellular reduced glutathione resulting in an oxidation of sulfhydryl groups in hemoglobin and possibly red cell membranes.

Mice administered multiple doses of cyclophosphamide demonstrated a marked resistance to infection with the bacterium, Listeria monocytogenes . In contrast, acute exposure rendered mice more susceptible to infection than untreated controls. Resistance to infection with Listeria , a facultative intracellular organism, is thought to be dependent upon normal antimicrobial activity early after infection and subsequently through generation of primed T cells. Examination of various macrophage and immune functions, however, failed to demonstrate a significant difference between the two cyclophosphamide-treated groups although both groups were immunosuppressed when compared to untreated controls. Adoptive transfer studies into X-irradiated recipients revealed that repopulation with bone marrow cells from subchronic but not acute cyclophosphamide-treated mice, restored resistance. Furthermore, the numbers of granulocyte/macrophage progenitor cells in the bone marrow were elevated in subchronically treated mice but not acute or unexposed controls. These data suggest the selection of a granulocyte/macrophage progenitor cell possessing a high degree of antilisterial activity following subchronic cyclophosphamide treatment. The effects induced by this exposure regimen are probably related to the enrichment of this cell population resulting from the cell cycle stage specific activity of the drug.

Healthy male Fischer 344 rats were sampled at 6, 12, 18, and 24 months of age. There was no gross pathological evidence or deviations in body weight, hematology, or clinical chemistry that were indicative of disease. Mixed populations of thymus, spleen, and pulmonary cells were obtained for enzymatic analyses. Key enzymes from the hexose monophosphate shunt, glycolysis and the tricarboxylic acid cycle were evaluated to determine if there were tissue-specific or pathway-specific changes that occurred during aging. The enzyme responses among the tissues were not consistent during the aging process. Generally the activities of the glucose metabolizing enzymes in thymus and pulmonary lavage cells decreased with age whereas they increased in the spleen cells. Between 18 and 24 months enzymes representative of all three glucose metabolic pathways decreased in pulmonary lavage cells, whereas the decreases in thymic cells were mainly restricted to glycolytic enzymes. By contrast there were two- to ten-fold increases during aging in all of the splenic enzymes measured except malate dehydrogenase. The alterations in tissue enzyme activities probably reflected the changing cellular populations during aging, and in the thymic and pulmonary lavage cellular environment resulted in a loss of energy production by glucose oxidation, compared to the vigorous activity maintained in spleen.

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Hepatic clearance is a major route of endotoxin detoxification. In the present study, the potential relationship between TCDD-induced endotoxin hypersensitivity and hepatotoxicity was examined. Acute doses of 50, 100, o 200 μg TCDD/kg body weight induced an endotoxin hypersensitive state in B6C3F 1 mice as demontrated by increased mortality 24–48 h following i.v. injection of endotoxin. This hypersensitive state occurred when endotoxin was administered 7 days following TCDD exposure, but not 1 day post-TCDD exposure. TCDD did not affect endogenous serum endotoxin levels. However, clearance of injected endotoxin was significantly inhibited following exposure to TCDD. Six hours post endotoxin treatment serum triglycerides were significantly increased in TCDD/endotoxin-treated mice compared to either treatment alone. Methylprednisolone and uridine were both examined in this model due to their roles in inflammation and RNA synthesis, respectively. Both compounds significantly reversed the mortality associated with the combined exposure. [ 3 H]Uridine incorporation into liver was decreased following TCDD treatment alone, further suggesting impaired RNA synthesis. Studies performed on congenic mice indicate that the observed effects segregate with the Ah locus. The ability of methylprednisolone and uridine to reverse the mortality associated with TCDD/endotoxin treatment is consistent with an inflammatory response and impaired hepatic detoxification mechanisms. Thus, changes in hepatic handling of endotoxin, caused by progressive TCDD-induced liver dysfunction, may be responsible for the endotoxin hypersensitivity.

A testing battery will be described for assessing alterations in immunological function and host resistance following exposure of B6C3F1 mice to TCDD, DES and BP. TCDD is a major contaminant of the defoliant 2,4,5 T (agent orange); DES is a potent synthetic estrogen used therapeutically to prevent menopausal symptoms and post-coital implantation, and as a weight promotant in cattle; and BP is the principal carcinogen in cigarette smoke and coal tar. Mice exposed perinatally to TCDD (5, 1 μg/kg) exhibited marked thymus atrophy and depressed mitogenic responses. Resistance to Listeria monocytogenes, gram-negative endotoxin and transplantable syngeneic tumor cells were likewise impaired. The mice appeared to have a specific T-cell defect associated with a receptor for TCDD present at high levels in thymic tissue. Mice exposed to DES at 8.0, 2.0 and 0.2 mg/kg of body weight for 5 days exhibited severe thymus atrophy accompanied by depression of the following parameters: antibody PFC response to SRBC and LPS; delayed cutaneous hypersensitivity; lymphoproliferative response to T- and B-cell mitogens and alloantigens; bone marrow cellularity; and stem and granulocyte-macrophage progenitor cell proliferation. Macrophages were activated relative to phagocytic, proliferative and tumoricidal responses with evidence of suppressor cell activity. Host resistance parameters were likewise impaired. Thus, DES exposure resulted in RES stimulation, severely depressed immunological and host resistance function, due in part to macrophage suppressor cells and possibly a T-cell defect. Finally, BP was dosed at 400, 200 and 50 mg/kg of body weight over 10 days. BP exposed mice demonstrated depressed antibody PFC responses; lymphoproliferative responses to mitogens; and depressed numbers of bone marrow macrophage-granulocyte progenitors. Macrophage function and host resistance to Listeria and tumor cells were unaffected. These data demonstrate the sensitivity of the immune response for detecting selective or non-specific chemical toxicity and support the hypothesis that certain carcinogens may operate via immunological mechanisms.