PFNA

Project ID

2633

Category

PFAS

Added on

Aug. 10, 2017, 7:19 a.m.

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Journal Article

Abstract  Kupffer cells are resident macrophages of the liver and play an important role in its normal physiology and homeostasis as well as participating in the acute and chronic responses of the liver to toxic compounds. Activation of Kupffer cells directly or indirectly by toxic agents results in the release of an array of inflammatory mediators, growth factors, and reactive oxygen species. This activation appears to modulate acute hepatocyte injury as well as chronic liver responses including hepatic cancer. Understanding the role Kupffer cells play in these diverse responses is key to understanding mechanisms of liver injury. Idiosyncratic drug-induced liver disease results in morbidity and mortality, impacting severely on the development of new pharmacological agents. Modulation of the response of Kupffer cells by drugs has been suggested as a cause for the idiosyncratic response. Similarly, liver damage seen in chronic ethanol consumption appears to be modulated by Kupffer cell activation. More recent evidence has noted a contributory role of Kupffer cell activation in the process of hepatic carcinogenesis. Several nongenotoxic carcinogens, for example, activate Kupffer cells resulting in the release of cytokines and/or reactive oxygen species that induce hepatocyte cell proliferation and may enhance clonal expansion of preneoplastic cells leading to neoplasia. Kupffer cells therefore appear to play a central role in the hepatic response to toxic and carcinogenic agents. Taken together, the data presented in this symposium illustrate to the toxicologist the central role played by Kupffer cells in mediating hepatotoxicity.

Journal Article

Abstract  Deafness is a common result of severe hypothyroidism during development in humans and laboratory animals; however, little is known regarding the sensitivity of the auditory system to more moderate changes in thyroid hormone homeostasis. The current investigation compared the relative sensitivity of auditory function, motor function, and growth to the effects of moderate to severe perinatal hypothyroidism in the rat. Rats received propylthiouracil (PTU) in drinking water at concentrations of 0, 1, 5, and 25 ppm from Gestation Day 18 until postnatal day (PND) 21, and the effects on their offspring were evaluated. At 1 ppm, PTU did not affect any of the measured endpoints. Serum thyroxin concentrations were sharply reduced in the 5 and 25 ppm PTU groups at all ages sampled (PND 1, 7, 14, and 21). Marked reductions in serum triiodothyronine (T3) concentrations were also detected for all ages > or = 7 at 25 ppm PTU, whereas no effects of 5 ppm PTU on serum T3 were apparent until PND 21. Compared to the controls, pups exposed to the highest dose of PTU demonstrated a delay in eye opening, reduced body weights, decreased and/or delayed preweaning motor activity, and persistent, postweaning hyperactivity. Only slight and transient effects on eye opening and ontogeny of motor activity were seen at the intermediate dose of PTU (5 ppm). Reflex modification audiometry revealed that, compared to controls, adult offspring from the 5 and 25 ppm treatment groups showed dose-dependent auditory threshold deficits (35 to > 50 dB) at all frequencies tested (1, 4, 16, 32, and 40 kHz). Such dose-dependent effects indicate that the developing auditory system may be sensitive to mild hypothyroidism, suggesting the possible need for routine audiometric screening for infants and children at risk for iodine deficiency, myxedema, and/or exposure to thyrotoxic environmental agents.

Journal Article

Abstract  Developmental iodine deficiency (ID) leads to inadequate thyroid hormone that impairs learning and memory with an unclear mechanism. Here, we show that hippocampal extracellular signal-regulated kinase (ERK1/2) and cAMP response element-binding protein (CREB) are implicated in the impaired learning and memory in lactational and adolescent rat hippocampus following developmental ID and hypothyroidism.

Three developmental rat models were created by administrating dam rats with either iodine-deficient diet or propylthiouracil (PTU, 5 ppm or 15 ppm)-added drinking water from gestational day (GD) 6 till postnatal day (PN) 28. Then, the total and phorsporylated ERK1/2 and total and phorsporylated CREB in the hippocampus were detected with western blot on PN14, PN21, PN28 and PN42.

The iodine-deficient and hypothyroid pups showed lower serum FT3 and FT4 levels, smaller body size, and delayed eyes opening. The mean number of surviving cells in the hippocampus of the iodine-deficient and 15 ppm PTU-treated rats was significantly reduced compared to controls (P < 0.05). Iodine-deficient and 15 ppm PTU-treatment groups demonstrated significantly lower level of total and phosphorylated ERK1/2 and CREB than the controls on PN14, PN21 and PN28 (P < 0.05, respectively). The reduction of ERK1/2 and CREB was not reversible with the restoration of serum thyroid hormone concentrations on PN42.

Developmental ID and hypothyroidism down-regulate hippocampal ERK1/2 and CREB in lactational and adolescent rats.

Journal Article

Abstract  This position paper delineates the expert recommendations of the Regulatory Affairs Committee of the American Society for Veterinary Clinical Pathology for the use of preclinical, clinical pathology endpoints in assessment of the potential for drug-induced hepatic injury in animals and humans. Development of these guidelines has been based on current recommendations in the relevant preclinical and human clinical trial literature; they are intended to provide a method for consistent and rigorous interpretation of liver-specific data for the identification of hepatic injury in preclinical studies and potential liability for hepatic injury in human patients.

Journal Article

Abstract  The biodegradability of several potential endocrine disrupting compounds, namely 4-n-nonylphenol (4-n-NP), nonylphenol monoethoxylate (NP1EO), nonylphenol diethoxylate (NP2EO), bisphenol A (BPA), triclosan (TCS), di-(2-ethylhexyl)-phthalate (DEHP), perfluorooctanoate (PFOA) and perfluorononanoate (PFNA) was evaluated in this study, using OECD method 301F (manometric respirometry test) and activated sludge as inoculum. According to the results, 4-n-NP and BPA meet the strict definition of ready biodegradability and they are not expected to be persistent during the activated sludge process. Partial biodegradation was observed for DEHP (58.7+/-5.7%, n=3), TCS (52.1+/-8.5%, n=3) and NP1EO (25.9+/-8.1%, n=3), indicating their possible biodegradation in wastewater treatment systems, while no biodegradation was observed for NP2EO, PFOA and PFNA. Experiments in the co-presence of a readily biodegradable compound showed the absence of co-metabolic phenomena during 4-n-NP, BPA and TCS biodegradation. Using first order kinetics to describe biodegradation of the target compounds, half-lives of 4.3+/-0.6, 1.3+/-0.2, 1.8+/-0.5, 6.9+/-2.6 days were calculated for 4-n-NP, BPA, TCS and DEHP, respectively. Toxicity tests using marine bacterium Vibrio fischeri showed that biodegradation of 4-n-NP, NP1EO, BPA and TCS is a simultaneous detoxification process, while possible abiotic or biotic transformations of NP2EO, DEHP, PFOA and PFNA during respirometric test resulted to significant increase of their toxicities.

Journal Article

Abstract  Many goitrogenic xenobiotics that increase the incidence of thyroid tumors in rodents exert a direct effect on the thyroid gland to disrupt one of several possible steps in the biosynthesis, secretion, and metabolism of thyroid hormones. This includes (a) inhibition of the iodine trapping mechanism, (b) blockage of organic binding of iodine and coupling of iodothyronines to form thyroxine (T4) and triiodothyronine (T3), and (c) inhibition of thyroid hormone secretion by an effect on proteolysis of active hormone from the colloid. Another large group of goitrogenic chemicals disrupts thyroid hormone economy by increasing the peripheral metabolism of thyroid hormones through an induction of hepatic microsomal enzymes. This group includes central nervous system-acting drugs, calcium channel blockers, steroids, retinoids, chlorinated hydrocarbons, polyhalogenated biphenyls, and enzyme inducers. Thyroid hormone economy also can be disrupted by xenobiotics that inhibit the 5'-monodeiodinase that converts T4 in peripheral sites to biologically active T3. Inhibition of this enzyme by FD&C Red No. 3 lowers circulating T3 levels, which results in a compensatory increased secretion of thyroid stimulating hormone (TSH), follicular cell hypertrophy and hyperplasia, and an increased incidence of follicular cell tumors in 2-yr or lifetime studies in rats. Physiologic perturbations alone, such as the feeding of an iodine-deficient diet, partial thyroidectomy, natural goitrogens in certain foods, and transplantation of TSH-secreting pituitary tumors in rodents also can disrupt thyroid hormone economy and, if sustained, increase the development of thyroid tumors in rats. A consistent finding with all of these goitrogens, be they either physiologic perturbations or xenobiotics, is the chronic hypersecretion of TSH, which places the rodent thyroid gland at greater risk to develop tumors through a secondary (indirect) mechanism of thyroid oncogenesis associated with hormonal imbalances.

Journal Article

Abstract  Perfluorooctanoic acid (PFOA) is an environmentally persistent chemical used in the manufacturing of a wide array of industrial and commercial products. PFOA has been shown to induce tumors of the liver, testis and pancreas (tumor triad) in rats following chronic dietary administration. PFOA belongs to a group of compounds that are known to activate the PPARα receptor. The PPARα activation Mode of Action was initially addressed in 2003 [9] and further refined in subsequent reviews [92-94]. In the intervening time, additional information on PFOA effects as well as a further refinement of the Mode of Action framework warrants a re-examination of this compound for its cancer induction Mode of Action. This review will address the rodent (rat) cancer data and cancer Mode of Action of PFOA for tumors of the liver, testes and pancreas.

Journal Article

Abstract  Perfluoroalkyl substances (PFASs) can interfere with male reproductive function, but evidence in humans is limited. Six hundred four fertile men (199 from Greenland, 197 from Poland and 208 from Ukraine) were enrolled in the study. We measured four PFASs in serum (PFOS, PFOA, PFNA and PFHxS) and concurrent DNA damage in spermatozoa by sperm chromatin structure assay (SCSA) and in situ terminal deoxynucleotidyl transferase dUTP nick-end labeling (TUNEL) assay, apoptotic markers in semen (Fas-receptor and Bcl-xL), and reproductive hormones in serum. No association between PFASs and SCSA, apoptotic markers or reproductive hormones emerged. We observed a slight increase in SHBG and TUNEL-positivity with increased PFOA exposure in men from Greenland. Thus, consistent evidence that PFAS exposure interferes with sperm DNA fragmentation, apoptosis or reproductive hormones was not found.

Journal Article

Abstract  Perfluorinated compounds (PFCs) are persistent and bioaccumulative organic compounds used as additives in many industrial products. After use, these compounds enter wastewater treatment plants (WWTP) and long-chain PFCs are primarily accumulated in sludge. The aim of this study was to determine the occurrence and behavior of five PFCs in sludge from 15 WWTP from Spain and Germany that receive both urban and industrial wastes. The PFCs studied were perfluorooctanesulfonate (PFOS), perfluorohexanesulfonate (PFHxS), perfluorobutanesulfonate (PFBS), perfluorooctanoic acid (PFOA), and perfluorononanoic acid (PFNA). One gram of freeze-dried, sieved, and homogenized sludge was extracted using an ultrasonic bath with methanol and glacial acetic acid. After that, the extract was recovered and evaporated to dryness with a TurboVap and then 1 mL of acetonitrile was added and the extract was cleaned up with black carbon. Liquid chromatography coupled to mass spectrometry operated in selected reaction monitoring was used to determine target compounds. Quality parameters are provided for the set of compounds studied. PFCs were detected in all samples. In Spanish sludge, ∑PFC ranged from 0.28 to 5.20 ng/g dry weight (dw) with prevalence of PFOS, while in German sludge, ∑PFC ranged from 20.7 to 38.6 ng/g dw and PFBS was the dominant compound. As a next step, the evolution of PFC concentrations within the sludge treatment steps (primary sludge, anaerobic digested sludge, and centrifuged sludge) was evaluated and differences among levels and patterns were observed and were attributed to the influent water quality and treatment used. Finally, we estimated the amount of PFCs discharged via sludge in order to determine the potential impact to the environment according to different sludge usage practices in the two regions investigated. This manuscript provided an intra-European overview of PFC distribution in sludge. Levels and compound distribution depend on the WWTP sampled. This study demonstrates that PFCs are persistent to sludge treatment and the loads in sludge may pose a future environmental risk, if not controlled.

Journal Article

Abstract  Bifenthrin (BF), a broad-spectrum and widely used synthetic pyrethroid, is a typical chiral pesticide. More attention is being paid to the health risk assessment of the enantioselective toxicity of BF isomers. In this study, we used rat ovarian granulosa cells as in vitro model to investigate effects of BF enantiomers on the biosynthesis of two hormones, progesterone and prostaglandin E2 (PGE2), which are critical for mammalian reproduction. We showed that 1S-cis-BF, but not 1R-cis-BF significantly decreased the secretion of progesterone and PGE2 in granulosa cells. 1S-isomer of BF reduced the expression of genes P450scc, StAR, PBR and DBI, as well as COX-2, which are involved in regulating the rate-limiting steps of progesterone or PGE2 biosynthesis. The transcriptional activation of StAR and COX-2 promoter were disrupted by 1S-cis-BF. Furthermore, activity of protein kinase C (PKC), an important signaling mediator of progesterone and PGE2 synthesis, was differentially inhibited by 1S-cis-BF. The data of molecular docking revealed that one hydrogen bond was formed between 1S-cis-BF and PKC protein. In conclusion, we firstly reported in this study the enantioselective disrupting effects of BF isomers on progesterone and PGE2 synthesis via PKC pathway in rat ovarian cells. Our findings suggest that the enantioselective toxicity of chiral pesticides should be considered for evaluating mammalian reproductive health, a toxicologic endpoint of great concern in health risk assessment.

Journal Article

Abstract  BIOSIS COPYRIGHT: BIOL ABS. Since early 1980s Drosophila melanogaster larvae heterozygous for recessive visible markers and those with defective DNA repair capability have been intensively used as simple in vivo testers of mutagenicity of environmental agents. In pallalel with this activity, the somatic tests have recently been deployed as tools for the detection of modifiers of the mutagenicity and understanding of basic mechanisms of the effects. Here, I characterize the somatic systems in relation to the biotransforming

Journal Article

Abstract  Perfluorinated compounds (PFCs) are widely used in everyday life and one of the main recipients of these compounds is waste water treatment plants (WWTPs). Due to the structure and physicochemical properties of PFCs, these compounds could be redistributed from influent water to sludge. This work reports a new validated protocol for the analysis of 13 perfluorinated acids, 4 perfluorosulfonates and the perfluorooctanesulfonamide. The present work has been focused to develop a sensitive and robust method for the analysis of 18 PFCs in sewage sludge, based on pressurized solvent extraction (PSE) followed by solid phase extraction (SPE) clean-up, analytes separation by liquid chromatography and analysis in a hybrid quadrupole-linear ion trap mass spectrometer (LC-QLiT-MS/MS) working in single reaction monitoring (SRM) mode. The final methodology was validated using a blank sewage sludge fortified at different concentration levels. The method limits of detection were ranging in general from 15 to 79 ng/kg. These values were comparable to the decision limit (CCα) and the detection capability (CCβ), which were 17-1134 ng/kg and 18-1347 ng/kg, respectively. The percentage of recovery was from 79 to 111% in the most cases at different spiked levels. Finally, the repeatability of the method was in the range 4% (PFOS and PFOA) to 25% (RSD %). In order to evaluate the applicability of the method, 5 sludge samples were analyzed. The results showed that the 18 PFCs were present in all samples. However, the concentrations for most of them were below the limits of quantification. The compound present at higher concentrations was perfluorooctanesulfonate (PFOS), which was in concentrations from 53.0 to 121.1 μg/kg. The other PFCs were at concentrations between 0.3 and 30.3 μg/kg.

Journal Article

Abstract  Introduction: Cancer is a complex disease, characterized by redundant aberrant signaling pathways as a result of genetic perturbations at different levels. Botanicals consist of a complex mixture of constituents and exhibit pharmacological effects by the interaction of many phytochemicals. The multitarget nature of botanicals could, therefore, be a relevant strategy to address the biological complexity that characterizes tumors. Areas covered: This article reviews the current status of botanicals in the oncological field and the challenges associated with their complex nature. Expert opinion: Botanicals are an important new pharmacological strategy, which are potentially exploitable in the oncological area but are characterized by a number of problems still unresolved. Content variation of products is one of the primary problems with botanicals and, consequently, there is a concern about the therapeutic consistency in marketed batches. Furthermore, metabolic interactions with antineoplastic drugs and the genotoxic potential of botanicals need to be properly addressed throughout the various phases of botanical drug development. These issues not only pose a serious problem to the approvability of those botanical products as new drugs but also present as a limitation to their post-approval clinical use.

Journal Article

Abstract  Perfluoroalkylated compounds (PFCs) are used in fire-fighting foams, treatment of clothes, carpets and leather products, and as lubricants, pesticides, in paints and medicine. Recent developments in chemical analysis have revealed that fluorinated compounds have become ubiquitously spread and are regarded as a potential threats to the environment. Due to the carbon-fluorine bond, which has a very high bond strength, these chemicals are extremely persistent towards degradation and some PFCs have a potential for bioaccumulation in organisms. Of particular concern has been the developmental toxicity of PFOS and PFOA, which has been manifested in rodent studies as high mortality of prenatally exposed newborn rats and mice within 24 h after delivery. The nervous system appears to be one of the most sensitive targets of environmental contaminants. The serious developmental effects of PFCs have lead to the upcoming of studies that have investigated neurotoxic effects of these substances. In this review the major findings of the neurotoxicity of the main PFCs and their suggested mechanisms of action are presented. The neurotoxic effects are discussed in light of other toxic effects of PFCs to indicate the significance of PFCs as neurotoxicants. The main findings are that PFCs may induce neurobehavioral effects, particularly in developmentally exposed animals. The effects are, however, subtle and inconclusive and are often induced at concentrations where other toxic effects also are expected. Mechanistic studies have shown that PFCs may affect the thyroid system, influence the calcium homeostasis, protein kinase C, synaptic plasticity and cellular differentiation. Compared to other environmental toxicants the human blood levels of PFCs are high and of particular concern is that susceptible groups may be exposed to a cocktail of substances that in combination reach harmful concentrations.

Journal Article

Abstract  Perfluorinated compounds (PFCs) are man-made fluoro-surfactants that are identified as global pollutants and can pose health risks to humans and wildlife. Two aspects of risk assessment were conducted in this study, including exposure and response. Exposure was estimated by using the concentrations of PFCs in fish and applying standard exposure factors. Among different PFCs, PFOS, PFOA, PFNA, PFDA, PFUdA and PFTrDA were detected. Total concentrations of PFC in fish ranged from 0.27-8.4 ng g(-1) to 0.37-8.7 ng g(-1) respectively in Hong Kong and Xiamen. The calculated hazard ratio (HR) of PFOS for all fish was less than 1.0. However, the HR for mandarin fish in Hong Kong and bighead carp, grass carp and tilapia in Xiamen, had HR values of approximately 0.5, indicating that frequent consumption of these 4 more contaminated fish species might pose an unacceptable risk to human health. Our data support the notion that the released/disposed chemical pollutants into water systems make fish a source of environmental toxicants to humans. The risks and potential effects of PFCs to health of coastal population in the Pearl River Delta are of concern.

Journal Article

Abstract  In this study, the presence of 18 perfluorinated compounds was investigated in biota and environmental samples from the Antarctica and Tierra de Fuego, which were collected during a sampling campaign carried out along February and March 2010. 61 samples were analysed including fish, superficial soils, guano, algae, dung and tissues of Papua penguin by liquid chromatography coupled to tandem mass spectrometry. The concentrations of PFCs were ranging from 0.10 to 240 ng/g for most of the samples except for penguin dung, which presented levels between 95 and 603 ng/g for perfluorooctane sulfonate, and guano samples from Ushuaia, with concentration levels of 1190-2480 ng/g of perfluorohexanoic acid. PFCs acids presented, in general, the highest levels of concentration and perfluorooctanesulfonate was the most frequently found compound. The present study provides a significant amount of results, which globally supports the previous studies, related to the transport, deposition, biodegradation and bioaccumulation patterns of PFCs.

Journal Article

Abstract  Spatial trends of concentrations of perfluorinated chemicals (PFCs) were investigated in harbour seal liver tissue from seven locations in Denmark, ranging from the Wadden Sea in the southern North Sea to the Western Baltic. All samples were collected during the phocine distemper epizootic in 2002 which provided access to a large number of comparable samples over a short time period. PFOS was dominating (mean: 92% of ∑PFC) among the PFCs in the samples, followed by considerably lower concentrations of PFHxS (1.8%), PFDA (1.7%), PFNA (1.6%) PFUnA (1.5%), PFOA (0.9%) and PFOSA (0.5%). The concentrations of all the investigated compounds showed significant differences among the seven locations. PFOS showed the highest concentrations in the Wadden Sea, where high burdens have also been recorded in German seals. Most compounds showed a trend towards higher concentrations at one or both extremes of the geographic range. Two different patterns of relative PFC concentrations were detected; one in the inner Danish waters where PFOSA and PFUnA were more prevalent and another in the Wadden Sea and Limfjord where PFOA, PFHxS and PFNA were found in greater proportions. These patterns probably represent Baltic and North Sea contamination sources.

Journal Article

Abstract  Perfluorooctanesulfonate (PFOS) at 1.6-39 ng/g ww and 4.8-200 pg/mL, respectively, perfluorooctanoate (PFOA) at 0.06-0.28 ng/g ww and<0.05-1.8 pg/mL, and perfluorodecanoate (PFDA) at 0.13-0.57 ng/g ww and 0.05-1.8 pg/mL, were detected in all specimens of European Beaver's (Castor fiber) liver as well as in whole blood of Cod (Gadus morhua), Velvet Scoter (Melanitta fusca), Eider Duck (Sommateria mollisima), Long-tailed Duck (Clangula hyemalis), Razorbill (Alca torda), Red-throated Diver (Gavia stellata) sampled in Poland. At smaller concentrations and at less frequency was perfluorononanoate (PFNA) at 0.05-1.4 ng/g ww and<0.2-2 pg/mL, perfluorohexanoate (PFHxA) at 0.03-0.23 ng/g ww and<0.05-0.69 pg/mL, while perfluorohexanesulfonate (PFHxS) at 0.05-4.3 pg/mL and perfluorooctanesulfonamidoacetate (PFOSA) at 0.1-13 pg/mL were also found in Cod as well as in molluscivorous diving-ducks and fish-eating birds but not in Beaver, while perfluoroheptanoate (PFHpA) at<0.05-0.74 pg/mL was found only in Cod.

Journal Article

Abstract  Perfluorinated compounds (PFCs) are environmentally widespread, persistent, and bioaccumulative chemicals with multiple toxicities reported in experimental models and wildlife, including immunomodulation. The two most commonly detected compounds, which also generally occur in the highest concentrations in environmentally exposed organisms, are perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS). PFOA and PFOS have been reported to alter inflammatory responses, production of cytokines, and adaptive and innate immune responses in rodent models, avian models, reptilian models, and mammalian and nonmammalian wildlife. Mounting evidence suggests that immune effects in laboratory animal models occur at serum concentrations below, within the reported range, or just above those reported for highly exposed humans and wildlife. Thus, the risk of immune effects for humans and wildlife exposed to PFCs cannot be discounted, especially when bioaccumulation and exposure to multiple PFCs are considered. This review contains brief descriptions of current and recently published work exploring immunomodulation by PFOA, PFOS, and other PFCs in rodent models, alternative laboratory models, and wildlife.

Journal Article

Abstract  In the first part of a series of studies to account for perfluorooctane sulfonate (PFOS)-induced sheep red blood cell (SRBC)-specific immunoglobulin M (IgM) antibody suppression in mice, a survey of clinical and immunotoxicological endpoints was examined. Adult female B₆C₃F₁ mice were exposed orally for 28 days to a total administered dose (TAD) of 0, 0.1, 0.5, 1, or 5 mg PFOS/kg. Uterus wet weight was significantly decreased compared with control at the 5 mg/kg dose. No indications of wasting syndrome, malnutrition, alteration of thyroid homeostasis, or signs of overt toxicity were observed. Numbers of splenic CD19+/CD21⁻, CD19+/CD21+, B220+/CD40+, CD4+/CD154⁻, CD4+/CD154+, and MHC-II+ cells were not altered. Additionally, ex vivo interleukin-4 (IL-4), IL-5, and IL-6 production by in vitro anti-CD3- or phorbol myristate acetate-stimulated CD4+ T-cells was not affected. Ex vivo IL-6 production by B-cells was significantly increased by in vitro stimulation with either anti-CD40 or lipopolysaccharide. Increased IL-6 production by B-cells was the most sensitive endpoint assessed resulting in alterations at the lowest dose tested (0.1 mg/kg TAD) following anti-CD40 stimulation. Further studies are required to characterize effects on inflammatory markers such as IL-6 at environmentally relevant concentrations of PFOS and to determine the key events associated with PFOS-induced IgM suppression to address potential human health risks.

Journal Article

Abstract  Perfluorooctanoic acid (PFOA), a member of the perfluoroalkyl acids that have wide commercial applications, has recently been detected in humans and wildlife. The current study characterizes the developmental toxicity of PFOA in the mouse. Timed-pregnant CD-1 mice were given 1, 3, 5, 10, 20, or 40 mg/kg PFOA by oral gavage daily from gestational day (GD) 1 to 17; controls received an equivalent volume (10 ml/kg) of water. PFOA treatment produced dose-dependent full-litter resorptions; all dams in the 40-mg/kg group resorbed their litters. Weight gain in dams that carried pregnancy to term was significantly lower in the 20-mg/kg group. At GD 18, some dams were sacrificed for maternal and fetal examinations (group A), and the rest were treated once more with PFOA and allowed to give birth (group B). Postnatal survival, growth, and development of the offspring were monitored. PFOA induced enlarged liver in group A dams at all dosages, but did not alter the number of implantations. The percent of live fetuses was lower only in the 20-mg/kg group (74 vs. 94% in controls), and fetal weight was also significantly lower in this group. However, no significant increase in malformations was noted in any treatment group. The incidence of live birth in group B mice was significantly lowered by PFOA: ca. 70% for the 10- and 20-mg/kg groups compared to 96% for controls. Postnatal survival was severely compromised at 10 or 20 mg/kg, and moderately so at 5 mg/kg. Dose-dependent growth deficits were detected in all PFOA-treated litters except the 1-mg/kg group. Significant delays in eye-opening (up to 2-3 days) were noted at 5 mg/kg and higher dosages. Accelerated sexual maturation was observed in male offspring, but not in females. These data indicate maternal and developmental toxicity of PFOA in the mouse, leading to early pregnancy loss, compromised postnatal survival, delays in general growth and development, and sex-specific alterations in pubertal maturation.

DOI
Book/Book Chapter

Abstract  This text provides a concise and clearly presented discussion of all the elements in a meta-analysis. It is illustrated with worked examples throughout, with visual explanations, using screenshots from Excel spreadsheets and computer programs such as Comprehensive Meta-Analysis (CMA) or Strata.

Journal Article

Abstract  A special challenge in the new European Union chemicals legislation, Registration, Evaluation and Authorisation of Chemicals, will be the toxicological evaluation of chemicals for reproductive toxicity. Use of valid quantitative structure-activity relationships (QSARs) is a possibility under the new legislation. This article focuses on a screening exercise by use of our own and commercial QSAR models for identification of possible reproductive toxicants. Three QSAR models were used for reproductive toxicity for the endpoints teratogenic risk to humans (based on animal tests, clinical data and epidemiological human studies), dominant lethal effect in rodents (in vivo) and Drosophila melanogaster sex-linked recessive lethal effect. A structure set of 57,014 European Inventory of Existing Chemical Substances (EINECS) chemicals was screened. A total of 5240 EINECS chemicals, corresponding to 9.2%, were predicted as reproductive toxicants by one or more of the models. The chemicals predicted positive for reproductive toxicity will be submitted to the Danish Environmental Protection Agency as scientific input for a future updated advisory classification list with advisory classifications for concern for humans owing to possible developmental toxic effects: Xn (Harmful) and R63 (Possible risk of harm to the unborn child). The chemicals were also screened in three models for endocrine disruption.

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