Disruptor

Endoei ine Disruptor Sereening and Testing Advisory Committee, Einal Report, EPA, Washington, 1998. 

European Commission, European Workshop on the Impact of Endocrine Disruptors on Human Health and Wildlife, Weybridge, 2—4 Dec. 1996, Environment and Climate Researeh Programme, European Commission, DG XII, Brussels, Report EUR 17549. 

It is also clear that it is difficult to relate cause and effect to any specific chemical since, with the exception of point source effluents, many waterways contain a multitude of chemicals, of which the active endocrine disruptor may not be that which has been measured in the water or tissue. For such reasons, many studies have used in vitro experiments in which isolated tissue, either from a control animal or one captured in a polluted water system, is exposed to a single pollutant in the laboratory. Such experiments have shown significant disruption to testicular activity by a wide range of xenobiotics, including cadmium, lindane, DDT, cythion, hexadrin and PCBs. ... 

Table 1 Chemicals which can be considered as potential endocrine disruptors in fish"...

Recently, attention has focused on the potential hazardous effects of certain chemicals on the endocrine system because of the abihty of these chemicals to mimic or block endogenous hormones, or otherwise interfere with the normal function of the endocrine system. Chemicals with this type of activity are most commonly referred to as endocrine disruptors. Some scientists believe that chemicals with the ability to disrupt the endocrine system are a potential threat to the health of humans, aquatic animals, and wildlife. Others believe that endocrine disrupting chemicals do not pose a significant health risk, particularly in light of the fact that hormone mimics exist in the natural environment. Examples of natural hormone mimics are the isoflavinoid phytoestrogens (Adlercreutz 1995 Livingston 1978 Mayr et al. 1992). 

NMR Studies on Lipid Bilayer Interfaces Coupled with Anesthetics and Endocrine Disruptors... 

FIG. 1 Molecular structures of the drugs examined in the delivery study the general anesthetics, alkanols (I), halothane (II), enflurane (III), isoflurane (IV), halogenated cyclobutane (V) the local anesthetics, dibucaine hydrochloride (VI), procaine hydrochloride (VII), tetracaine hydrochloride (VIII), lidocaine hydrochloride (IX), benzyl alcohol (X) the endocrine disruptor, bisphenol A (XI), and alkylbenzenes, benzene (XII), toluene (XIII), ethylbenzene (XIV), and propylbenzene (XV). 

In this section, we focus on how to determine DD sites by NMR. The specification of the DD sites in bilayers can be done by utilizing the NMR signals of both drugs and membrane lipids. An example of the delivery site determination is given for the case of two benzene derivatives, propylbenezene (PrBe) and benzyl alcohol (BzOH) in egg phosphatidylcholine (EPC) bilayers [46]. Alkylbenzenes are suspected to be endocrine disruptors, and BzOH is one of the local anesthetics. 

V. LIPID BILAYER INTERFACES COUPLED WITH ENDOCRINE DISRUPTORS, BISPHENOL A, AND ALKYLBENZENES... 

As an example of suspected endocrine disruptors (EDs), studies of the estrogenic action of bisphenol A (BPA) have been in progress in medical, physiological, and biological fields. In this situation, physicochemical approaches are required to get the structural information of BPA trapped in biomembranes. Most recently, we have determined the site and the orientation of BPA trapped in phospholipid vesicles by NMR, using the HCS rule [47]. In particular, we have succeeded in monitoring the NMR spectral changes of phospholipid vesicles, which are induced by the BPA delivery. 

In recent years the interest of environmental analytical chemistry was turned to the so-called emerging contaminants or new unregulated contaminants including pharmaceuticals, endocrine disruptors, detergents, personal care products, plasticizers, flame retardants, gasoline additives, etc. These compounds are released continuously to the environment and can be found in water, sediments, soils, etc. In most of the cases they are found at trace level concentration (ng/L) therefore, powerful analytical capabilities are required for their determination. 

Convention on Control of Transboundary Movements of Hazardous Wastes and their Disposal and 69 ratified the ban on all kinds of hazardous waste export from wealthy OECD-countries to non-OECD countries, large amounts of waste electrical and electronic equipment (WEEE) are shipped overseas for recycling, the majority to China as reported by Brigden et al. [2] and Puckett et al. [3], lesser quantities to India and Western Africa reported by Kuper and Hojsik [4]. WEEE contains a variety of harmful substances like endocrine disruptors and persistent organic pollutants (POPs). Additionally, hazardous substances may be formed during informal recycling. This often practised informal treatment without proper equipment for metal extraction and labour safety heavily affects the environment and human health of workers and the inhabitants of whole stretches of land. 

Langdon KA, Wame MS, Smemik RJ, Shareef A, Kookana RS (2011) Selected personal care products and endocrine disruptors in biosolids an Australia-wide survey. Sci Total Environ 409 1075-1081... 

Frequency and Intensity. Most ultrasonic baths operate in the 30 -80 kHz range. Frequency is rarely an important factor, provided the frequency is low enough to permit cavitation. The cell disruptors normally adapted for sonochemical uses operate at 20 kHz. The intensity must be enough to produce cavitation. Beyond that, optimum intensities for heterogeneous reactions have not been determined. 

Bioanalytical and Chemical Methods for Endocrine Disruptors Volume Editors D. Barcelo and P.-D. Hansen Vol. 5/J, 2009... 

Kasprzyk-Hordern B, Dinsdale RM, Guwy AJ (2008) The occurrence of pharmaceuticals, personal care products, endocrine disruptors and illicit drugs in surface water in South Wales, UK. Water Res 42 3498-3518... 

Porte C, Janer G, Lorusso LC, Ortiz-Zarragoitia M, Cajaraville MP, Fossi MC, Canesi L (2006) Endocrine disruptors in marine organisms approaches and perspectives. Comp Bio-chem Physiol C 143 303-315... 

The chemical structure of the substances capable of interacting with a determinate nuclear receptor is tremendously varied. For now no pattern exists that permits one to assure that a particular substance is going to interact with the receptor to produce an agonist or antagonist effect. In recent years the concept of endocrine disruptors has been introduced to describe the substances that are capable of modifying the endocrine equilibrium. Some of them act by binding with nuclear hormone receptors, while others interfere with the processes of regulation of hormone secretion (Lathers 2002 Melnick et al. 2002 Nakata 2002 Powles 2002 Brown et al. 2002 Sonnenschein et al. 1998). 

Endocrine disruptors apparently affect all nuclear receptors. Thus, a notable increment in impotence, alterations of the libido and of oligospermia in workers exposed to pesticides has been described. These alterations are due to the action of some compounds with estrogen-mimetic action and to their interaction with the androgen receptor. Additionally, alterations of thyroid function have been detected in rats exposed to dioxin and other toxic agents,... 

Lathers CM (2002) Endocrine disruptors a new scientific role for clinical pharmacologists Impact on human health, wildlife, and the environment. J Clin Pharmacol 2 7... 

Melnick R, Lucier G, Wolfe M, Hall R, Stancel G, Prins G, Gallo M, Reuhl K, Ho SM, Brown T, Moore J, Leakey J, Haseman J, Kohn M (2002) Summary of the National Toxicology Program s report of the endocrine disruptors low-dose peer review. Environ Health Perspect 110 427... 

Nakata K (2002) Theoretical approach to endocrine disruptors. Front Biosci 7 c68... 

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