Skip to main content

Endocrine Disrupting Chemicals In Food

In Order to Read Online or Download Endocrine Disrupting Chemicals In Food Full eBooks in PDF, EPUB, Tuebl and Mobi you need to create a Free account. Get any books you like and read everywhere you want. Fast Download Speed ~ Commercial & Ad Free. We cannot guarantee that every book is in the library!

Endocrine Disrupting Chemicals in Food

Endocrine Disrupting Chemicals in Food Book
Author : I Shaw
Publisher : Elsevier
Release : 2009-03-31
ISBN : 1845695747
Language : En, Es, Fr & De

GET BOOK

Book Description :

The rise in the incidence of health problems such as reproductive disorders and testicular and breast cancer has been linked by some to endocrine disrupting chemicals in the environment. The role of food in transmitting these chemicals is uncertain and a topic of considerable research. This important book addresses key topics in this area. The first part of the book reviews the impacts of endocrine disrupting chemicals on health and behaviour, with chapters on the effect of dietary endocrine disruptors in such areas as the developing foetus, cancer and bone health. Parts two and three focus on the origin and analysis of endocrine disruptors in food products and risk assessment. Topics addressed include surveillance, analysis techniques such as biosensors, exposure assessment and the relevance of genetics, epigenetics and genomic technologies to the study of endocrine disrupting chemicals. Concluding chapters discuss examples of selected endocrine disrupting chemicals associated with food, such as dioxins, polychlorinated biphenyls and brominated flame retardants, bisphenol A and phytoestrogens and phytosterols. With its distinguished editor and international team of contributors, Endocrine-disrupting chemicals in food is an essential reference for all those concerned with ensuring the safety of food. Reviews the impacts of endocrine disrupting chemicals on health and behaviour including cancer and reproductive disorders Addresses the origin and analysis of endocrine disruptors with chapters on surveillance and analysis techniques Examines the relevance of genetics, epigenetics and genomic technologies to endocrine disrupting chemicals

Endocrine Disrupting Chemicals in Food 9781845692186 KE QTN 0016 09

Endocrine Disrupting Chemicals in Food   9781845692186  KE QTN 0016 09 Book
Author : I. Shaw
Publisher : Unknown
Release : 2009
ISBN : 0987650XXX
Language : En, Es, Fr & De

GET BOOK

Book Description :

Download Endocrine Disrupting Chemicals in Food 9781845692186 KE QTN 0016 09 book written by I. Shaw, available in PDF, EPUB, and Kindle, or read full book online anywhere and anytime. Compatible with any devices.

Endocrine Disrupting Chemicals

Endocrine Disrupting Chemicals Book
Author : M. C. Edwards
Publisher : Unknown
Release : 2003
ISBN : 0987650XXX
Language : En, Es, Fr & De

GET BOOK

Book Description :

Download Endocrine Disrupting Chemicals book written by M. C. Edwards, available in PDF, EPUB, and Kindle, or read full book online anywhere and anytime. Compatible with any devices.

Analysis of Endocrine Disrupting Compounds in Food

Analysis of Endocrine Disrupting Compounds in Food Book
Author : Leo M. L. Nollet
Publisher : John Wiley & Sons
Release : 2011-06-09
ISBN : 0470961848
Language : En, Es, Fr & De

GET BOOK

Book Description :

Analysis of Endocrine Disrupting Compounds in Food provides a unique and comprehensive professional reference source covering most of the recent analytical methodology of endocrine disrupting compounds in food. Editor Nollet and his broad team of international contributors address the most recent advances in analysis of endocrine disrupting chemicals in food. While covering conventional (typically lab-based) methods of analysis, the book focuses on leading-edge technologies that recently have been introduced. The book looks at areas such as food quality assurance and safety. Issues such as persistent organic pollutants, monitoring pesticide and herbicide residues in food, determining heavy and other metals in food and discussing the impacts of dioxins, PCBs, PCDFs and many other suspected chemicals are covered. The book discusses the relationship between chemical compounds and hormone activity. What are the health impacts of different chemical compounds for men and animals? How are these compounds entering in foodstuffs? Analysis of Endocrine Disrupting Compounds in Food offers the food professional what its title promises – a compendium of sample preparation and analysis techniques of possible endocrine disrupting compounds in food. Special Features: Uniquely concentrates on analysis and detection methods of EDCs in foodstuffs Extensive coverage of the main types of globally available analytical techniques and methodologies Fully detailed properties, sample procedures, and analysis steps for each EDC Renowned editor Leo Nollet leads a broad team of international experts

Hormone Disruptive Chemical Contaminants in Food

Hormone Disruptive Chemical Contaminants in Food Book
Author : Ingemar Pongratz,Linda Bergander
Publisher : Royal Society of Chemistry
Release : 2011-10-28
ISBN : 1849732973
Language : En, Es, Fr & De

GET BOOK

Book Description :

Today, we are surrounded by a multitude of different chemicals that are essential components of our everyday life. As a consequence, there are various hazardous substances like dioxins, phthalates and flame-retardants circulating in the environment. These have an impact on ecosystems, wildlife and possibly human health. In recent years, the phenomenon called endocrine disruption has raised considerable concern. This book discusses the scientific basis of this issue using epidemiological and experimental in vitro and in vivo data about chemicals targeting the hormonal systems. It also provides an up-to-date review of international initiatives (including high-throughput screening, use of model organisms and in silico applications) aiming to screen, detect and functionally test these chemicals. The authors are highly experienced academics and acknowledged experts with both multidisciplinary and international expertise. The book provides an up-to-date, in-depth review of the current field of food safety research describing many of the "hot topics" currently debated. Recent media attention concerning, for example, dioxins in meat and bisphenol A in baby bottles has created a growing interest in food safety-related issues from both consumers and authorities. In addition, European legislation REACH, which requires industry to extensively test chemicals, has led to new initiatives within this area. This book presents a comprehensive overview of the recent international initiatives formed to meet the challenges of environmental pollutants in our food.

New EU criteria for endocrine disrupters

New EU criteria for endocrine disrupters Book
Author : Nordic Council of Ministers
Publisher : Nordic Council of Ministers
Release : 2018-08-30
ISBN : 9289356863
Language : En, Es, Fr & De

GET BOOK

Book Description :

Endocrine disruptors (EDs) are substances that adversely affect hormone function. The effects by EDs are thought to depend on both dose and timing of exposure, especially during foetal development. The upcoming EU regulation on identification of EDs, application biocides and pesticides, will have an impact on all actors of the food chain. The consequences of a ban of EDs in foods were discussed in a Nordic workshop (Uppsala, 29-30 Nov 2016) where risk assessors and managers from Nordic food authorities, industry, trade associations, consumer organizations and researchers were represented. It was recognized by all participants that a ban was particularly challenging for the production chain since there are few viable alternatives. A harmonized EU legislation based on scientific risk assessment was preferred compared to national specific legislation as it treats all the actors equally.

Endocrine disrupting Chemicals in Drinking Water

Endocrine disrupting Chemicals in Drinking Water Book
Author : United States. Congress. House. Committee on Energy and Commerce. Subcommittee on Energy and Environment
Publisher : Unknown
Release : 2012
ISBN : 0987650XXX
Language : En, Es, Fr & De

GET BOOK

Book Description :

Download Endocrine disrupting Chemicals in Drinking Water book written by United States. Congress. House. Committee on Energy and Commerce. Subcommittee on Energy and Environment, available in PDF, EPUB, and Kindle, or read full book online anywhere and anytime. Compatible with any devices.

Mechanistic Evaluation of Endocrine Disrupting Chemicals

Mechanistic Evaluation of Endocrine Disrupting Chemicals Book
Author : Camilla Taxvig
Publisher : Unknown
Release : 2011
ISBN : 0987650XXX
Language : En, Es, Fr & De

GET BOOK

Book Description :

Download Mechanistic Evaluation of Endocrine Disrupting Chemicals book written by Camilla Taxvig, available in PDF, EPUB, and Kindle, or read full book online anywhere and anytime. Compatible with any devices.

Is It Safe

Is It Safe  Book
Author : Sarah A. Vogel
Publisher : Univ of California Press
Release : 2013
ISBN : 0520273575
Language : En, Es, Fr & De

GET BOOK

Book Description :

We are all just a little bit plastic. Traces of bisphenol A or BPA, a chemical used in plastics production, are widely detected in our bodies and environment. Is this chemical, and its presence in the human body, safe? What is meant by safety? Who defines it, and according to what information? Is It Safe? narrates how the meaning of the safety of industrial chemicals has been historically produced by breakthroughs in environmental health research, which in turn trigger contests among trade associations, lawyers, politicians, and citizen activists to set new regulatory standards. Drawing on archival research and extensive interviews, author Sarah Vogel explores the roots of the contemporary debate over the safety of BPA, and the concerns presented by its estrogen-like effects even at low doses. Ultimately, she contends that science alone cannot resolve the political and economic conflicts at play in the definition of safety. To strike a sustainable balance between the interests of commerce and public health requires recognition that powerful interests will always try to shape the criteria for defining safety, and that the agenda for environmental health research should be protected from capture by any single interest group.

Food Toxicology

Food Toxicology Book
Author : Ashish Sachan,Suzanne Hendrich
Publisher : Unknown
Release : 2017-10
ISBN : 9781771886178
Language : En, Es, Fr & De

GET BOOK

Book Description :

Biomarkers in food toxicology / Juan Antonio Gimenez Bastida and Jose Moises Laparra Llopis -- Mucosal exposome and food toxicity biomarkers / Yuseok Moon -- Toxicity of ingested nanomaterials / Yi Cao -- Safety evaluation of chemistries used in the food and beverage processing and packaging industries / Martin Hoagland, Kathryn Sande, Alison Behling, and Nathan Pechacek -- Developmental neurotoxicity considerations for food additive safety / Yen-Ching Wu, Shruti V. Kabadi, and April Neal-Kluever -- Protective effect of food-grade lactic acid bacteria against oxidative stress / J.E. Aguilar-Toala, B. Vallejo-Cordoba, A.F. Gonzalez-Cordova, R. Garcia-Varela, H.S. Garcia, A. Hernandez-Mendoza -- Mycotoxins / Suzanne Hendrich -- Endocrine-disrupting chemicals in food and their toxicological implications / S. Raisuddin and Shikha Sharma -- Radionuclides in foods / Mohamed Abdelrazek Abdelaleem -- Metal toxicity in foods / M. Carmen Rubio Armendariz, Arturo Hardisson de la Torre, Angel J. Gutierrez Fernandez, Dailos Gonzalez Weller, Soraya Paz Montelongo, Consuelo Revert Girones, And Jose M. Caballero Mesa -- Toxicological risks of waste burning residues in foods : a view on low-income countries / Ilaria Proietti and Alberto Mantovani -- Introduction to epithelial-to-mesenchymal transition and its role as potential marker in food toxicology / Ludovic Peyre and Maeva Giraudo -- Regulation and monitoring of pesticide residues in water and food in Brazil / Luciano Zanetti Pessoa Candiotto, Luneia Catiane de Souza, Vanessa Jacob Victorino and Carolina Panis -- Aptamers as advanced nanosensing tools in food safety / Ashish Sachan

In Vivo Models for the Study of Endocrine Disrupting Chemicals

In Vivo Models for the Study of Endocrine Disrupting Chemicals Book
Author : Alireza Hossaini
Publisher : Unknown
Release : 2000
ISBN : 9788790978587
Language : En, Es, Fr & De

GET BOOK

Book Description :

Download In Vivo Models for the Study of Endocrine Disrupting Chemicals book written by Alireza Hossaini, available in PDF, EPUB, and Kindle, or read full book online anywhere and anytime. Compatible with any devices.

The Endocrine Disruptors

The Endocrine Disruptors Book
Author : Maria Marino
Publisher : Unknown
Release : 2007-01-01
ISBN : 9788178952833
Language : En, Es, Fr & De

GET BOOK

Book Description :

In recent years, it has become evident that many chemicals present in the environment can mimic, antagonize or alter the physiological actions of endogenous hormones. These compounds have been termed endocrine disrupters (EDs) and defined as exogenous substances that cause adverse health effects in an intact organism or in its progeny, consequent to changes in endocrine function [1]. EDs, even when present in minute amounts (part per trillion), could interfere with the synthesis, secretion, transport, metabolism, binding, action, or elimination of natural hormones responsible for homeostasis maintenance, reproduction, and developmental processes [2]. Currently more than 100 chemicals have been identified as EDs. Within this heterogeneous group of molecules we find: (a) synthetic chemicals used in industry, agriculture, and consumer products; (b) synthetic chemicals used as pharmaceutical drugs; and (c) natural chemicals found in human and animal food. About half of these compounds are substituted with halogen groups, mostly chlorine and bromine, and include dioxins, polychlorinated biphenyls, organochlorine pesticides, methoxychlor, dieldrin, and hexachlorocyclohexane. EDs have long environmental half-life resulting in a continue increase of their global concentration in the environment and can be detected and may concentrate at great distances from where they are produced, used or released. EDs have very low water solubility and extremely high lipid solubility, leading to their bioaccumulation in adipose tissue. Exposure to EDs can occur from a number of different sources: humans and animals can be exposed involuntarily by drinking contaminated polluted water, breathing contaminated air, ingesting food, contacting contaminated soil or even in the workplace. Although endocrine disruption has only received high-profile attention for just over a decade [2], the phenomenon does have a longer historical background. In the early 1900s, pig farmers in the USA complained of fertility problems in swine herds fed on moldy grain [3], and concern was stimulated in the 1940s by reports of infertility in sheep grazing on certain clovers in Western Australia [4]. Over the following two decades, estrogenic actions were evidenced in birds [5] and in mammals [6] owing to the dissemination of the agrochemical orto-dichlorodiphenyltrichloroethane (DDT), at the same time masculinization of bivalves and gastropods[7], with concomitant declines in population, was found in the 1970s with the introduction of tributyltin into antifouling paints for the boats, while feminization of fishes was observed in UK rivers in the presence of estrogenic components in sewage effluent [8]. Also the occurrence of genital abnormalities in both male and female alligators in Lake Apopka (FL, USA) were observed as effect of a spill of the pesticide difocol in 1980. After these first observations the scientific community increased the awareness of the consequences of exposure to chemicals which can interfere with reproductive functions [9]. Endocrine disruption in wildlife is now acknowledged to be a widespread problem, much resulting from environmental pollution, and, in the case of aquatic forms of wildlife, from the continuous exposure to these chemicals in the water. Extrapolation of the results of these researches on wildlife resulted in concern that the same compounds could interfere with hormone action in humans. Handling hazardous substances and the risk of exposure to chemicals are a painful part of modern life, as technology and science progress. Moreover, exposure to chemicals present in foods, at home, and at work is an important risk factor for human health, especially since our scientific knowledge is still not sufficient to ensure proper prevention. Nowadays there is justifiable concern that endocrine disruption could be the underlying cause of increasing female and male reproductive problems, thus endocrine disruption is one of the topics receiving much attention throughout all sectors of the society, and the debate between pharmaceutical companies and public health organisms is increasing. Both parts will call for urgent need of more research. The scientific challenge for the future is to identify the relevant real-life sources of exposure of the human population to endocrine-disrupting compounds and to find the appropriate remediation actions. This can be done: (a) by assessing the impact on human health of long-term, low-dose exposure to such chemicals; (b) by understanding the synergistic effects of the copious number of chemicals to which humans and animals are exposed; (c) by defining the variety of underlying mechanisms at molecular, cellular and physiological level, (d) by exploiting new technologies addressed to the remediation of the environment polluted by the presence of EDs, and (e) by designing and developing new sensors or biosensors capable of determining their concentration in traces. The review presented in this book has been written under the sponsorship of the Interuniversitary Consortium National Institute of Biostructures and Biosystems (INBB) , constituted by 26 Public Italian Universities. INBB is stimulating the research on endocrine disruptors, by encouraging and coordinating joint research projects between its members and those of other Italian public scientific institutions. This book represents one of the results of the meeting The biological and clinical research on endocrine disruptors: current status and perspectives , held in Rome during 2005 from October 27 to 28 and organized by INBB and ISPESL (Istituto Superiore Prevenzione e Sicurezza del Lavoro). The first three chapters of this book review the EDs effects on natural population living in aquatic ecosystems where EDs, due to their lipophilicity, tend to concentrate in sediments and in food webs. The edible mussel Mytilus (Chapter 1), a marine bivalve that can accumulate large amounts of organic contaminants, represents a species of economical, ecological and public health-related interest. Amphibians (Chapter 2) are favourite models for studying various aspects of reproduction, development of the central nervous system and metamorphosis. Moreover, there is great concern about the EDs and the dramatic decline of wild amphibian populations. In Chapter 3 different species of fishes are considered as experimental models to analyze, by both genomic and proteomic approaches, the expression of key molecules involved in reproduction and in detoxification processes. The following two chapters focus on the EDs effects on thyroid functions and on the development of central mechanisms controlling reproduction. Wildlife observations in polluted areas clearly demonstrate a significant incidence of thyroid imbalance in several species. Several EDs are now known or suspected to be thyroid disruptors altering thyroid economy at multiple levels. These compounds may interfere

Analyzing Biomonitoring Surveillance Data on Endocrine disrupting Chemicals for Population Exposure Patterns and Health Outcomes

Analyzing Biomonitoring Surveillance Data on Endocrine disrupting Chemicals for Population Exposure Patterns and Health Outcomes Book
Author : Jessica Webb Nelson
Publisher : Unknown
Release : 2010
ISBN : 0987650XXX
Language : En, Es, Fr & De

GET BOOK

Book Description :

Abstract: The National Health and Nutrition Examination Survey (NHANES), conducted by the Centers for Disease Control and Prevention, collects biomonitoring measurements on a representative sample of the U.S. population. This dissertation analyzed biomonitoring data on polyfluoroalkyl chemicals (PFCs) and bisphenol A (BPA), both endocrine disrupting chemicals, to address three key environmental health research questions. Chapter 2 studied the relationship between serum concentrations of four PFCs and cholesterol levels, obesity, and insulin resistance in 2003-2004 data. In adults, three PFCs were positively associated with total and non-HDL cholesterol. We did not see consistent associations with obesity or insulin resistance. Though studies in workers and highly exposed communities found similar results, these are the first reported for the general population. Chapter 3 analyzed 2003-2004 data to determine whether intake of certain foods predicted serum PFCs. We found that consumption of fast food, take-out hot beverages, red meat, potatoes, and snack foods was associated with certain PFCs. These findings indicate that PFCs may enter the food chain through both bioaccumulation and food packaging materials. Chapter 4 investigated differences by socioeconomic position (SEP) and race/ethnicity in body burdens of PFCs and BPA in 2003-2006 data. Urinary BPA was higher in people with lower incomes, whereas the opposite was true for serum PFCs. Children with very low food security or who received emergency food had particularly high BPA levels. Mexican Americans had the lowest levels of both chemicals of any racial/ethnic group. The evidence that diet contributes to the SEP differences was stronger for BPA than PFCs. Income, education, occupation, and food security were not interchangeable as measures of SEP; environmental epidemiology studies should give more consideration to the choice of measures. Biomonitoring surveillance programs such as NHANES present a tremendous resource to environmental health researchers. Though limited in their ability to examine exposure-disease relationships, these data can provide useful hypotheses for future study. The opportunity they offer to investigate predictors of and disparities in exposure is unparalleled. The Boston Consensus Conference on Biomonitoring, which gathered input from the lay public on questions surrounding biomonitoring, provides important additional insights about the conduct of biomonitoring surveillance programs.

Endocrine Disrupting Chemicals

Endocrine Disrupting Chemicals Book
Author : Sabrina Johnston
Publisher : Unknown
Release : 2016
ISBN : 9781634852470
Language : En, Es, Fr & De

GET BOOK

Book Description :

"Wide variety of pesticides and other synthetic chemicals may disrupt the normal function of the endocrine system, cause alteration and also attack the immune system of humans and wildlife at very low concentration levels. Chapter one of this book provides an overview of analytical methods, including sample preparation steps, chromatographic separation and detection of endocrine disrupting pesticides in a variety of food, environmental and biological matrices. Chapter two studies endocrine disrupting compound (EDC) exposure from recycled wastewater compared to other water related risks in developed and developing nations. Chapter three summarizes the role of EDCs on pregnancy and birth outcomes, included but not limited to fertility problems, premature birth, low birth weight, and miscarriage along with in-vitro, animal, and epidemiological studies. In the last chapter, the worst EDCs will be revealed and their related potential hazardous health risks to humans are discussed. Furthermore, suggestions to help the reader avoid such toxic chemicals are presented"--

Analysis of Legacy and Emerging Flame Retardants Plasticizers and Their Metabolites in Food and Breast Milk

Analysis of Legacy and Emerging Flame Retardants  Plasticizers and Their Metabolites in Food and Breast Milk Book
Author : Daniel Furlong
Publisher : Unknown
Release : 2019
ISBN : 0987650XXX
Language : En, Es, Fr & De

GET BOOK

Book Description :

"On a daily basis, we are exposed to a wide variety of chemicals, such as flame retardants and plasticizers, that are incorporated into consumer products. Even at low doses, some of these chemicals have been found to disrupt the body's endocrine system, these are known as endocrine disrupting chemicals (EDCs). Due to the ubiquity of these substances, it is important to monitor our potential exposure to EDCs through diet. With this in mind, a multiclass extraction method was developed, optimized and validated for Polybrominated Diphenyl Ethers (PBDEs), Dechloranes, Organophosphate esters (OPEs) and their metabolites (mOPEs). Good recoveries are obtained for all analytes in all matrices (49-122%) with good repeatability (RSD 1-10%). The extracts were run on LC-QqQ-MS/MS for the separation and quantification of OPEs and mOPEs as well as GC-MS for the separation and quantification of PBDEs and Dechloranes. The chromatographic separation of Tri-tolyl phosphate (TCP) and isopropylphenyl diphenyl phosphate (ip-PDPP) isomers was achieved for the first time using LC-QTOF-MS. The method was applied to various food samples including fish, chicken, vegetables, canned fish, bread and butter as well as breast milk. Moreover, the current method is quicker, and less costly than other methods due to the reduction of required materials and processing steps. The occurrence of 14 OPEs and mOPEs was investigated in 66 composite food samples purchased from the greater Montreal market. Also, 100 breast milk samples were collected from new mothers in Montreal. All OPEs analyzed were detected above the quantification limit in at least one matrix. To investigate the effect of food packaging on the potential migration of OPEs and mOPEs into food, both packaged and non-packaged food samples were collected; however, there was no difference in the levels of OPEs or mOPEs in these samples (P>0.05). The lipid dependence of OPEs was also investigated by comparing the lipid content of the sample to the total levels of contaminants present; no trend was observed, thus, further suggesting the lipid independence of OPEs. The metabolism of OPEs was assessed by normalizing the detected OPE by the respective mOPE; most samples, including breast milk contained higher levels of OPE to mOPE. A notable exception is bread having higher levels for Tris(1,3-dichloro-2-propyl) phosphate to Bis(1-chloro-2-propyl) phosphate (TDCPP/BCIPP), Tris-tolyl phosphate to di-tolyl phosphate (TCP/DCP) and Tris(2-chloroethyl) phosphate to Bis(2-chloroethyl) phosphate (TCEP/BCEP); this may be due to the high temperature processing needed to bake bread.Considering the daily average intake of food for the average Canadian, the dietary exposure to OPE was estimated to be 12800 +/- 1500 ng/day [18322 ng/kg bw/day]. Several population groups were considered for dietary exposure including men, women, children (5-11 years) and young children (1-4 years). For all groups, values of OPEs were several orders of magnitude lower than their corresponding health-based reference doses. mOPEs currently do not have reference dose values and therefore are not included in the exposure assessment. The exposure to OPEs through breast milk for young infants (3 months) was also considered. Both males and females as well as high and low consumption patterns were assessed. For all groups, values of OPEs were several orders of magnitude lower than their corresponding health-based reference doses. By using the developed multiclass extraction method, it was possible to estimate the current dietary exposure levels of OPEs and mOPEs for Canadians. Based on this preliminary risk assessment, the Canadian population is exposed to a tolerable level of OPEs through diet, however, careful monitoring should continue and be expanded to other food groups in order to obtain a complete picture of dietary exposure to EDCs. With these data, policy makers can make more informed decisions with regards to replacement chemicals." --

Endocrine Disrupting Chemicals

Endocrine Disrupting Chemicals Book
Author : Karen Riiber Mandrup
Publisher : Unknown
Release : 2022-01-23
ISBN : 9788792763761
Language : En, Es, Fr & De

GET BOOK

Book Description :

Download Endocrine Disrupting Chemicals book written by Karen Riiber Mandrup, available in PDF, EPUB, and Kindle, or read full book online anywhere and anytime. Compatible with any devices.

Development Optimization and Application of Nuclear Receptor Dependent Cell based Bioassays for Endocrine Disruptors

Development  Optimization  and Application of Nuclear Receptor Dependent Cell based Bioassays for Endocrine Disruptors Book
Author : Jennifer Colleen Brennan
Publisher : Unknown
Release : 2015
ISBN : 9781339064246
Language : En, Es, Fr & De

GET BOOK

Book Description :

Endocrine disrupting chemicals (EDCs) include a wide variety of structurally diverse compounds that affect normal signaling pathways in most all animal species by multiple mechanisms. Given the global distribution of EDCs in environmental, biological and food samples and commercial products, detection, relative quantitation, and assessment of their biological/toxicological effects is of paramount importance. While instrumental methods allow detection and quantitation of specific (known) EDCs in sample extracts, these methods do not allow identification and characterization of new EDCs. Accordingly, mechanism-based bioanalytical methods have been developed to assist in the identification and characterization of matrices and extracts containing EDCs. The so-called chemically-activated luciferase expression (CALUX) bioassays and related CALUX-type bioassays represent a collection of nuclear receptor-based recombinant cell bioassays for detection of EDCs, including estrogenic-, androgenic- and dioxin-like chemicals. Although CALUX assays are much cheaper and quicker than instrumental analysis and whole animal assays, there is a critical need to make these assays as biologically/toxicologically relevant and consistent with our current understanding of endocrine disruption in order to provide optimal data for selection of chemicals (or mixtures) which warrant in vivo assessment. This includes improved assay characteristics (i.e., minimal detection limits (MDLs)) and response to EDCs, inclusion of more receptors (i.e. multiple subtypes of a given nuclear receptor) and consideration of receptor cross-talk and related mechanisms. In this dissertation, I describe two significantly improved CALUX bioassay systems for EDCs. The first is a set of species-specific Ah receptor (AhR)-responsive CALUX cell lines that exhibit dramatically increased sensitivity (10-100-fold lower MDL (to sub pM concentrations)) and responsiveness to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD, dioxin) and related dioxin-like compounds (DLCs), compared to current dioxin-responsive CALUX cell lines. I demonstrate the utility of these novel AhR-responsive CALUX bioassays in analysis of sediment extracts. The second CALUX cell line (estrogen receptor (ER)-CALUX) is a modification of our existing estrogen-responsive human cell line (BG1Luc4E2). Although this cell line has received official regulatory approval from the USEPA and OECD (to the point of being included in the USEPA Endocrine Disruptor Screening Program) and is currently being utilized by the Tox21 program for chemical screening purposes, this cell line only expresses one of the two known human ER subtypes (ER[alpha]). Since both ER subtypes (ER[alpha] and ER[beta]) can differ in their ligand-specificity, cross-talk with other signaling and transcription factors and gene induction profiles, optimal cell bioassay assays should be able to detect the full spectrum of ER-active chemicals (i.e., activators/repressors of ER[alpha] and/or ER[beta]). Accordingly, we stably transfected the ER[alpha]-containing BG1LucE2 CALUX cell line with a human ER[beta] expression vector and screening of the resulting BG1LucER[beta] clones with the ER[beta]-selective ligands genistein and Br-ER[beta]-041 allowed identification and isolation of a clonal cell line (BG1LucER[beta]c9) expressing ER[beta] and highly responsive to ER[beta]-selective ligands. Comparison of the response of BG1Luc4E2 and BG1LucER[beta]c9 cell lines to a chemical library of 176 compounds revealed that the ER[alpha]/ER[beta]-containing BG1LucER[beta]c9 cell line can identify a greater number of potential estrogenic chemicals than the ER[alpha]-containing BG1Luc4E2 cell line. Since cross-talk between the AhR and ER has been identified as a potential mechanism for endocrine disruption in animals exposed to DLCs (which act to repress ER gene signaling), in the final chapter I explored cross-talk between AhR and ER in a human breast carcinoma cell line (SKBR3). I specifically focused on the effect of ER[alpha]/ER[beta] on AhR gene signaling in transiently transfected cells. In SKBR3 cells (which lack functional ER), we observed an ER[alpha] subtype-specific enhancement of AhR-dependent reporter gene expression (from the transfected AhR-responsive plasmid pGudLuc6.1) in the absence of added E2 and a repression of the ER-dependent enhancement of AhR signaling by stimulating transfected ER[alpha] with E2, PPT, or fulvestrant (no repression was observed with ER[beta]). The repressive effect of E2 could be abolished by co-incubation of E2-activated ER[alpha]-transfected SKBR3 cells with the ER antagonist 4-hydroxytamoxifen, demonstrating the requirement for functionally active ER[alpha]. Our ER-dependent repressive results in SKBR3 cells indicate that AhR has selective interactions with ER[alpha] versus ER[beta]. The results presented in this dissertation demonstrate that the CALUX reporter vectors and stable cell lines not only have application for highly sensitive high throughput screening for EDCs systems, but for in-depth mechanistic studies examining crosstalk between receptor signaling pathways which can play a critical role in endocrine disruption.

Endocrine Disrupting Chemicals

Endocrine Disrupting Chemicals Book
Author : Andrea C. Gore
Publisher : Springer Science & Business Media
Release : 2007-06-08
ISBN : 159745107X
Language : En, Es, Fr & De

GET BOOK

Book Description :

This book provides comprehensive coverage of the three most important themes in the field of Endocrine Disrupting Chemicals (EDC) research: the basic biology of EDCs, particularly their effects on reproductive systems; EDC effects on humans and wildlife, including biomedical considerations; and potential interventions and practical advice for dealing with the problem of EDCs.