Book Description
This digital document is a journal article from Chemosphere, published by Elsevier in 2007. The article is delivered in HTML format and is available in your Amazon.com Media Library immediately after purchase. You can view it with any web browser.

Description:
The aim of this study was to test a specific method for the detection of Vitellogenin (Vtg) and Zona Radiata Proteins (Zrp) in plasma from peregrine falcon (Falco peregrinus) as specific biomarkers for the evaluation of the effects of endocrine disruptors. The method was assayed with different peregrine falcon individuals (including mature and immature birds of both sexes) from a Spanish population being studied in terms of their contamination with organochlorine compounds with endocrine disrupting properties. This study shows that mouse anti bird Vtg monoclonal antibody ND3C3 (Biosense) seems to be the most specific antibody in binding plasmatic lipoproteins in peregrine falcon when compared to other anti Vtg antibodies. Rabbit anti salmon Zrp polyclonal antibodies O146 (Biosense) show cross-reactivity with Zrp in the samples studied. These preliminary results confirm the applicability of both of these diagnostic tools assayed (induction of Vtg and Zrp) in detecting exposure to Endocrine Disrupting Chemicals (EDCs) in this species. The increase of Vtg and Zrp detected in male specimens suggest a potential hazard to EDCs in the peregrine falcon which represents a species still affected by organochlorine compounds, and in particular those with estrogenic activity. ... Read more

Book Description
This digital document is a journal article from Science of the Total Environment, The, published by Elsevier in 2004. The article is delivered in HTML format and is available in your Amazon.com Media Library immediately after purchase. You can view it with any web browser.

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Samples were collected from two stormwater canals and a recreational urban waterway known as Bayou St. John in New Orleans, Louisiana, USA and analyzed for a range of pharmaceuticals and personal care products (PPCPs) and endocrine disrupting chemicals (EDCs). Concentrations of 7 PPCPs and EDCs were measured by a method that provides for simultaneous extraction and quantification of the following compounds: clofibric acid, naproxen, ibuprofen, fluoxetine, clorophene, triclosan, bisphenol A. The method also was used as an indicator of the occurrence of estrogenic compounds by targeting estrone and 17@b-estradiol. The two canals (Orleans and London) are used to drain a portion of the city's stormwater directly into the Mississippi River or Lake Pontchartrain. Bayou St. John is located between the two canals and supplied with water from Lake Pontchartrain. Results from the 6-month sampling period indicated the following concentration ranges for the two stormwater canals: naproxen (ND - 145 ng/l), ibuprofen (ND - 674 ng/l), triclosan (ND - 29 ng/l) and bisphenol A (1.9-158 ng/l). Concentrations of these target analytes increased with cumulative rainfall. For bayou waters, only naproxen (2.1-4.8 ng/l) and bisphenol A (0.9-44 ng/l) were detected. Estrone was detected but determined non-quantifiable for multiple sampling events at the 3 sites. None of the other target analytes (clofibric acid, fluoxetine, clorophene, and 17@b-estradiol) were detected above their method detection levels. Results of this study demonstrate the occurrence of PPCPs and EDCs in New Orleans stormwater canals and Bayou St. John. Results also demonstrate the use of this analytical technique as an indicator of non-point source sewage contamination in New Orleans stormwater canals. ... Read more

Book Description
This digital document is an article from Environmental Health Perspectives, published by Thomson Gale on May 1, 2007. The length of the article is 6858 words. The page length shown above is based on a typical 300-word page. The article is delivered in HTML format and is available in your Amazon.com Digital Locker immediately after purchase. You can view it with any web browser.

Citation Details
Title: Tetrahydrofurandiols (THF-diols), leukotoxindiols (LTX-diols), and endocrine disruption in rats.(Research)(Case study)(Clinical report)
Author: Barry M. Markaverich
Publication: Environmental Health Perspectives (Magazine/Journal)
Date: May 1, 2007
Publisher: Thomson Gale
Volume: 115Issue: 5Page: 702(7)

Article Type: Case study, Clinical report

Distributed by Thomson Gale ... Read more

Book Description
The field of endocrine disruption or endocrine active compounds (EACs), which is just emerging and still controversial, is comprehensively covered by leading experts in Volume 3, Subvolumes L (the present volume, Part I) and M (Part II). The major classes of endocrine active chemicalsare discussed, as well as methods for their detection andtheir association with health disturbances in humans andwildlife. The etiology of several of the human diseasesassociated with endocrine disruptors, e.g. breast andprostate cancer, decreased fertility and malformations, isstill poorly understood, and the current state of knowledgeis presented. Since hormonally active agents appear to havethe potential of both adverse and beneficial effects, theevidence of health benefits associated with endocrine active compounds in humans is also presented. Basic chapters on the mode of action of EACs and on the etiology of the associated diseases facilitate the understanding of this complexsubject for non-medical readers. ... Read more

Book Description
"Preventing Children's Exposure to Endocrine Disruptors - A Teaching Aid" is a publication in the series "Protecting Children's Health." It is a slide show presentation to help parents and teachers understand the complex technical issues involved with this new category of chemical pollutants that threaten our children. These chemicals do not appear to harm adults. However, they harm our children and the younger the child is the greater is the risk of harm. The unborn child is thus at greatest risk. Endocrine disruptors affect the developing fetus and young children by causing a variety of endocrine and reproductive system defects including malformations of newborns, undecended testicles, abnormal sperm, low sperm counts, feminization of males and masculinization of females, thyroid dysfunction, various types of cancer such as cervical, breast and prostate cancer, etc. Dr. Keith presents an overview of what is known and what is not yet known about these chemical pollutants at a level that everyone can understand. The very latest developments are presented along with ways to prevent or minimize children's exposure to these chemicals. Using this knowledge, parents and teachers will be able to read and discuss new developments in this critical field as they unfold over the next several years. The slides may be used with Microsoft's PowerPoint Viewer for presentations or printed for handouts. Teachers will be able to use this publication for materials that can be used to discuss this topic at PTA meetings, other community and public outreach forums, and in the classroom. ... Read more

Book Description
This digital document is a journal article from Mutation Research-Reviews in Mutation Research, published by Elsevier in 2005. The article is delivered in HTML format and is available in your Amazon.com Media Library immediately after purchase. You can view it with any web browser.

Description:
Effluent discharges are released into aquatic environments as complex mixtures for which there is commonly either no knowledge of the toxic components or a lack of understanding of how known toxicants interact with other effluent components. Effects-directed investigations consist of chemical extraction and iterative fractionation steps directed by a biological endpoint that is designed to permit the identification or characterization of the chemical classes or compounds in a complex mixture responsible for the observed biological activity. Our review of the literature on effects-directed analyses of effluents for non-mutagenic as well as mutagenic endpoints showed that common extraction and concentration methods have been used. Since the mid-1980s, the methods have evolved from the use of XAD resins to C18 solid-phase extraction (SPE). Blue cotton, blue rayon, and blue chitin have been used specifically for investigations of mutagenic activity where polycyclic compounds were involved or suspected. After isolation, subsequent fractionations have been accomplished using SPE or a high-pressure liquid chromatography (HPLC) system commonly fitted with a C18 reverse-phase column. Substances in active fractions are characterized by gas chromatography/mass spectrometry (GC-MS) and/or other spectrometric techniques for identification. LC-MS methods have been developed for difficult-to-analyze polar substances identified from effects-directed studies, but the potential for LC-MS to identify unknown polar compounds has yet to be fully realized. Salmonella-based assays (some miniaturized) have been coupled with fractionation methods for most studies aimed at identifying mutagenic fractions and chemical classes in mixtures. Effects-directed investigations of mutagens have focused mostly on drinking water and sewage, whereas extensive investigations of non-mutagenic effects have also included runoff, pesticides, and pulp mill effluents. The success of effects-directed investigations should be based on a realistic initial objective of each project. Identification of chemical classes associated with the measured biological endpoint is frequently achievable; however, confirmation of individual compounds is much more difficult and not always a necessary goal of effects-directed chemical analysis. ... Read more

Book Description
This digital document is a journal article from Journal of Hazardous Materials, published by Elsevier in 2007. The article is delivered in HTML format and is available in your Amazon.com Media Library immediately after purchase. You can view it with any web browser.

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n-Butyl benzyl phthalate (BBP) is an endocrine-disrupting chemical. Biodegradation of BBP by a bacterium, Pseudomonas fluorescens B-1, isolated from the mangrove sediment, was investigated. The microorganism can utilize BBP as the sole carbon and energy source, where concentrations of BBP disappeared within 6 days under shake culture conditions. Effects of BBP concentration, pH, temperature, and salinity on BBP biodegradation were studied, respectively. The process of BBP biodegradation was monitored by reversed-phase high-performance liquid chromatography with ultra-violet detection after solid-phase extraction. The biodegradation of BBP could be fitted to a first-order kinetic model. The major metabolites of BBP degradation were identified as mono-butyl phthalate, mono-benzyl phthalate, phthalic acid and benzoic acid by gas chromatography-mass spectrometry, and a preliminary metabolic pathway of BBP was proposed. ... Read more

Book Description
This digital document is a journal article from Environmental Research, published by Elsevier in 2006. The article is delivered in HTML format and is available in your Amazon.com Media Library immediately after purchase. You can view it with any web browser.

Description:
Organochlorine compounds (OCCs), such as pesticides and polychlorinated biphenyls (PCBs), are persistent lipophilic chemicals identified as endocrine disruptors, mainly with estrogen-like effects. Northeastern Argentina, near the Parana River, is characterized by intensive farming and agricultural activities and industrial development, and is therefore prone to high incidences of environmental and dietary exposure to OCCs. Hence, we conducted a study to (1) estimate the organochlorine residues present in mammary fat tissue in a population of women from this littoral region and (2) identify potential sources of exposure to OCCs. Our subjects were 76 women (residing in and around Santa Fe city and not occupationally exposed to organochlorines) who underwent excision biopsy of a breast lesion or had plastic surgery. Both frequency of occurrence and levels of organochlorine residues were high in breast adipose tissue of all the participants. The organochlorine residues most frequently found were p,p'-dichlorodiphenyldichloroethylene (p,p'-DDE) in all the subjects analyzed, hexachlorobenzene (HCB) in 86.8%, and @b-hexachlorocyclohexane (@b-HCH) in 75.0%. The incidence of PCB congeners was very low. p,p'-DDE and @b-HCH residues reached the highest levels, 4794 and 1780ppb, respectively. The diet was a relevant source of exposure, consumption of animal fat and freshwater fish playing a significant role. Bioaccumulation was evidenced by the significant positive association between organochlorine levels and body mass index (p=0.0003) and the age of the patient (p=0.0002). The frequency and levels of OCCs found in our study population raise concerns regarding Argentinean exposure to these endocrine disruptors. ... Read more

Book Description
This digital document is a journal article from Comparative Biochemistry and Physiology, Part C, published by Elsevier in 2005. The article is delivered in HTML format and is available in your Amazon.com Media Library immediately after purchase. You can view it with any web browser.

Description:
Cadmium uptake was studied in isolated adrenocortical cells of rainbow trout (Oncorhynchus mykiss) and yellow perch (Perca flavescens) to test the hypothesis that the greater sensitivity of trout cells to Cd-induced disruption of cortisol secretion observed in previous studies is correlated to higher level of metal accumulation. There was no evidence for interspecies differences in accumulation level, and a specific transport mechanism of similar affinity has been characterized in both fish species. However, inhibition of Cd uptake by calcium was observed in rainbow trout exclusively. The free metal ion Cd^2^+ and chlorocomplexes CdCl"n^2^-^n both contribute to Cd accumulation with different level of contribution between fish species. We conclude that interspecies differences in sensitivity to Cd endocrine disrupting effect are not necessarily related to different levels of metal accumulation but would rather be linked to transport pathways and metal speciation. Cadmium/calcium competition for uptake could be a determinant of the early Cd-induced impaired cortisol secretion in trout but not perch cells. ... Read more

Book Description
This digital document is a journal article from Bioresource Technology, published by Elsevier in 2007. The article is delivered in HTML format and is available in your Amazon.com Media Library immediately after purchase. You can view it with any web browser.

Description:
An aerobic diethyl phthalate (DEP) degrading bacterium, DEP-AD1, was isolated from activated sludge. Based on its 16S rDNA sequence, this isolate was identified belonging to Sphingomonas genus with 99% similarity to Sphingomonas sp. strain C28242 and 98% similarity to S. capsulate. The specific degradation rate of DEP was concentration dependent with a maximum of 14mg-DEP/(Lh). Results of degradation tests showed that DEP-AD1 could also degrade monoethyl phthalate (MEP), dimethyl phthalate (DMP), dibutyl phthalate (DBP), and diethylhexyl phthalate (DEHP), but not phthalate and benzoate. ... Read more

Book Description
This digital document is a journal article from Analytica Chimica Acta, published by Elsevier in 2004. The article is delivered in HTML format and is available in your Amazon.com Media Library immediately after purchase. You can view it with any web browser.

Description:
A specific recognition material for bisphenol A (BPA) was prepared by using a covalent imprinting technique. A chloroform solution containing bisphenol A dimethacrylate as a template, ethylene glycol dimethacrylate as a cross-linking agent and 2,2'-azobis(isobutyronitrile) as an initiator was polymerized by UV initiation. When BPA was removed from the resulting polymer by hydrolysis of the ester bonds with aqueous sodium hydroxide, carboxylic acid residues were generated in the polymer. After the polymer was packed into a stainless steel column, retention factors of BPA and related compounds were measured. The imprinted polymer adsorbed BPA and structurally related compounds such as 4,4'-dihydroxybenzophenone, bis(4-hydroxyphenyl)sulfone and 4,4'-dihydroxybiphenyl. A typical association constant (K"a) was calculated to be 1.72x10^5M^-^1 by Scatchard analysis. Interestingly, 17@a- and 17@b-estradiol were also bound to the imprinted polymer (K"a=1.68x10^5M^-^1), indicating that the polymer could be used as artificial receptors for screening the compounds having estrogenic action. ... Read more

Book Description
This digital document is a journal article from Chemosphere, published by Elsevier in 2007. The article is delivered in HTML format and is available in your Amazon.com Media Library immediately after purchase. You can view it with any web browser.

Description:
Many pesticides possess hormonal activity and have thus been classified as endocrine disruptors. Pyrethroids are commonly used pesticides worldwide, but little has been done to characterize their antiandrogenic activity potential. We tested three frequently encountered pyrethroids (fenvalerate, cypermethrin, permethrin) and their metabolite 3-phenoxybenzoic acid (3-PBA) for antiandrogenic and androgenic activity using a human androgen receptor (AR) mediated luciferase reporter gene assay in CV-1 African green monkey kidney cell. The assay displayed appropriate response to the known AR agonist 5@a-dihydrotestosterone and AR antagonist nilutamide and flutamide. At 0.1mM, all the three tested pyrethroids significantly suppressed the luciferase expression. Further, their metabolite 3-PBA also showed antagonist activity. None of the test chemicals showed androgenic activity. Through the antiandrogenic pathways, exposure to certain pyrethroids may contribute to the damage of reproductive system. In conclusion, pyrethroid pesticides can act as antiandrogen in vitro, and metabolizing to 3-PBA cannot eliminate the antagonist activity. This result provides useful information for risk assessment of pyrethroid pesticides. ... Read more

Book Description
This digital document is a journal article from Environmental Research, published by Elsevier in 2005. The article is delivered in HTML format and is available in your Amazon.com Media Library immediately after purchase. You can view it with any web browser.

Description:
We tested the ultraviolet screen 3-(4-methylbenzylidene)-camphor (4-MBC; Eusolex 6300), which has been implicated as a potential endocrine disruptor, for its potential to bind to and activate endogenous estrogen receptors (ER) and to mediate ER-dependent changes in gene transcription, in hepatocytes of the water-dwelling South African clawed frog Xenopus laevis. We were able to confirm previous findings that 4-MBC accelerates cell proliferation in estrogen-dependent human breast cancer cells (MCF-7). Results of competitive binding assays of [^3H]17@b-estradiol and 4-MBC using cytosolic protein preparations from Xenopus hepatocytes indicated that 4-MBC weakly binds to the ER. 4-MBC at a concentration of 100@mmol/L is not able to completely replace estradiol from the receptor. However, when 4-MBC was tested in a gene induction assay using the relative amount of ER transcript as a marker for ER-dependent transcriptional activation, we found that micromolar concentrations of this substance produced an increase in the amount of ER mRNA that was not different from the amount of mRNA that was observed upon activation of cells with 17@b-estradiol in concentrations above 1nmol/L. The results indicate that 4-MBC has the potential to change physiological and developmental processes mediated by ER signaling mechanisms. It may therefore be a potentially harmful substance for water-dwelling animals when present in the environment at micromolar concentrations. ... Read more

Book Description
This digital document is a journal article from Chemosphere, published by Elsevier in 2004. The article is delivered in HTML format and is available in your Amazon.com Media Library immediately after purchase. You can view it with any web browser.

Description:
A rapid Biacore biosensor immunoassay of 4-nonylphenols was developed. Two types of antibodies were used in the study: polyclonal antibodies with high cross-reactivity towards technical 4-nonylphenol and a monoclonal antibody very specific to 4-n-nonylphenol. 9-(p-Hydroxyphenyl)nonanoic acid was immobilized onto surface of a sensor chip. The best assay sensitivity was achieved using a flow rate of 50 @mlmin^-^1 and injection time of 2 min. For the assay incorporating monoclonal antibodies a limit of detection 2 ngml^-^1 for 4-n-nonylphenol was achieved. With polyclonal antibodies one order lower sensitivity was observed for 4-nonylphenols. High background level of calibration curve for technical 4-nonylphenol was decreased by using IgG fraction of polyclonal antibodies in combination with lower amount of immobilised 9-(p-hydroxyphenyl)nonanoic acid. Sensitivity of the assay was improved by using a chip with a new derivative on a surface-N-aminobutyl [2-(4-hydroxyphenyl)ethylamine] (limit of detection--5 ngml^-^1). Applicability of the developed assays to ecological monitoring was checked in experiments using shellfish samples. 4-n-Nonylphenol from spiked samples was extracted into hexane followed by clean-up on NH2 SPE columns. Calibration curves generated for cockles, mussels and oyster samples were identical (limit of detection about 10 ngg^-^1) whereas for scallop samples a slight decrease (about 5-10%) of absolute response was observed. In the assay using the monoclonal antibody specific to 4-n-nonylphenol 31 shellfish samples were found to be negative. Results obtained with polyclonal antibodies indicated that two scallop samples contained a quantity of 4-nonylphenols. The developed biosensor assay could be applied for shellfish analysis as a preliminary screening method. ... Read more