Disruptive potential

A number of other chemicals suspected of having endocrine disrupting potential also occur at high levels in the tissues of marine mammals. For example, tribiityltin compounds are present in the tissues of the Steller sea lion (Eumetopias juhatus) from Hokaido, Japan, and in stranded bottlenose dolphins (Tursiops truncatus) found along the US Atlantic and Gulf coasts.Additional chemicals detected include PAHs, toxaphene and chlordane. ... 

Calabrese EJ, Baldwin LA, Kostecki PT, et al. 1997. A toxicologically based weight-of-evidence methodology for the relative ranking of chemicals of endocrine disruption potential. Regul Toxicol Pharmacol 26 36-40. 

Petty et al. (1998, 2000) used a vitellogenin (VGT) assay to assess the endocrine disrupting potential of contaminants in purified SPMD extracts. VGT is an egg yolk phosphoprotein precursor that is synthesized in the liver of female teleosts in response to estrogen from the ovary (Bailey, 1957). A wide variety of environmental contaminants have been shown to have estrogenic activity (Colborn et al., 1993). Equal portions of purified extracts from SPMDs, exposed in the Missouri River after the flood of 1993 and from the IWWTP at the Nogales Wash deployment were individually injected into immature rainbow trout (Oncorhynchus mykiss) as described in Section 6.4. The SPMD extracts contained elevated levels of complex mixtures of contaminants, including PAHs and pesticides. The fish injected with these sample extracts exhibited VGT induction, while no induction was observed in fish injected with any of the blank sample extracts. 

The evaluation of existing data is an exercise that can take many forms. At present there is no generally accepted approach for the interpretation of the results of individual screens and tests. Moreover, there is no generally accepted WOE approach for the evaluation and interpretation of a series of screens or testing with the goal of classification of a chemical with regard to endocrine disruption potential. 

Despite this ambitious effort directed by the EPA, time and cost, and also limited screening and testing capabilities, mean that laboratory testing alone will not provide insight into the endocrine-disrupting potential of the many thousands of chemicals of interest. Statistical models and computational approaches hold out the promise of helping overcome this problem, and various efforts are under way in this regard. 

Results of CMR (Carcinogenic, Mutagenic, Reprotoxic) tests and statement on endocrine disrupting potential. 

Perkins, R., Anson, J., Blair, R., Branham, W.S., Dial, S., Fang, H., Hass, B.S., Moland, C., Shi, L., Tong, W., Welsh, W., Walker, J.D., and Sheehan, D.M., The endocrine disruptor knowledge base (EDKB), a prototype toxicological knowledge base for endocrine disrupting chemicals, in Handbook on Quantitative Structure Activity Relationships (QSARs) for Predicting Chemical Endocrine Disruption Potentials, Walker, J.D., Ed., SETAC Press, Pensacola, FL, 2003 (in press). 

Information on any other adverse effects to the environment should be included where available, such as environmental fate (exposure), ozone depletion potential, photochemical ozone creation potential, endocrine disrupting potential and/or global warming potential. 

Bisson, M. and A. Hontela. Cytotoxic and endocrine-disrupting potential of atrazine, diazinon, endosulfan and mancozeb in adrenocortical steroidogenic cells of rainbow trout exposed in vitro. Toxicol. Appl. Pharmacol. 180 110-117, 2002. 

Designed to cause harm Unknown source or quantity Information not readily available No specific safety plans in place Wider affected area Widespread consequential disruption Potentially many casualties Chemical effects could be accompanied by physical injuries... 

Constraints imposed by caldesmon that disrupt potentiation may not block myosin docking on actin. This process of modulating ATPase could in turn lead to or permit the development of the latch-state of tension maintenance displayed by tonic smooth muscles and observed at low Ca + concentration. This phenomenon probably involves stable actin-myosin binding and is associated with low actomyosin ATPase activity (Hai and Murphy, 1988 McDaniel et al, 1990). As envisioned, such tension maintenance would be incompatible with a troponin-tropomyosin form of regulation since tropomyosin would in that case block myosin docking at low Ca + concentrations. Hence, the caldesmon-tropomyosin system may be adapted for muscles that enter a latch-state. 

Toxicological studies have linked some phthalate esters to liver and kidney damage, and to possible testicular or reproductive birth defect problems, characterizing them as endocrine disruptors. In this way, up to 12 phthalate esters, such as DBF, BBP, DEHP, DIDP, and DINP are within the list of the proposed substances suspected to produce endocrine alterations published by the EU. The endocrine disruption potential of pthalate esters was recently reviewed by Harris and Sumpter. The U.S. Agency for Toxic Substances and Disease Registry (ASTDR), the World... 

Harris, C. A. and Sumpter, J. P., The endocrine disrupting potential of phthalates. In The Handbook of Environmental Chemistry, Part L, Endocrine Disruptors, Part /, Vol. 3, Metzler, M., Ed., Springer-Verlag, Berhn, pp. 169-201, 2001. 

Malathion shows a relatively high toxicity to fish, Morphological abnormalities in African catfish larvae exposed to malathion were observed (Lien ei al., 1997). Diazinon has no hormone-like activity but shows endocrine-disrupting potential in fish. In dispersed adrenocortical cells of rainbow trout, this compound suppressed cortisol secretion in response to ACTH in vitro (Bisson and Hontela,... 

From the appUcation of surfactants in household, handicraft and industry a large quantity of these compounds have been discharged with wastewaters and despite biological treatment considerable quantities of them have reached the environment Therefore surfactants continue to be an environmental concern. Knowledge of the endocrine disrupter potential of some surfactant metabolites had heightened pubhc interest about the fate of these pollutants. 

The determination of phenols was preferentially performed using GC-MS with analytes in underivatized or derivatized form, but LC-MS methods were also developed. API methods for the analysis of phenols in aqueous matrices were applied [315, 316, 317]. APCI-LC-MS was found to be more sensitive than ESI application despite the possibility of improving ESI-sensitivity by a post-column addition of diethyla-mine [317]. Detection limits were observed with 0.02-20 ng injected onto the column. The determination of alkylphenols and bisphenol A as compounds with endocrine disrupter potential was also performed by ESI-LC-MS from aqueous [318, 319] and sediment samples with detection limits in the low pg L range [346]. 

When contemplating LGI embolization there are some unique aspects of the history that need to be investigated. Knowing the past surgical history is important since prior intestinal surgery may have disrupted potential arterial collateral pathways and will increase the risk of an ischemic complication. If the patient has had radiation therapy to the... 

Wiener, L. F. and Capinera, J. L. (1979) Greenbug response to an alarm pheromone analog temperature and humidity effects, disruptive potential and analog releaser efficacy. Ann. ent. Soc. Am., 72, 369-71. 

Certain secondary structures in an RNA template may force the RTase to halt and/or terminate reverse transcription, which is often the cause of inefficient cDNA synthesis. To disrupt potential secondary structures, RNA templates are customarily denatured either by brief heating (30-60 sec at 100°C) or by treatment with methylmercuric hydroxide (CHjHgOH, 2.5 mM) followed by neutralization of the reagent with at least three times excess 2-MSH immediately prior to the addition of RTases (30). Despite the initial disruption of secondary structures hy either of the two methods mentioned earlier, RNA templates tend to regain, at least partially, their original secondary struaures during the period of incubation. The elevation of the reaction temperature, sometimes up to 55°C with AMV RTase, helps retard the process of refolding, while the elevated temperature increases the rate of polymerization by the RTase. However, the optimal temperature has to be compromised with the stability of the individual RTase. 

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