Hormones, environmental

Raman spectroscopy can be used for live, in situ, temporal studies on the development of bone-like mineral (bone nodules) in vitro in response to a variety of biomaterials/scaffolds, growth factors, hormones, environmental conditions (e.g. oxygen pressure, substrate stiffness) and from a variety of cell sources (e.g. stem cells, FOBs or adult osteoblasts). Furthermore, Raman spectroscopy enables a detailed biochemical comparison between the TE bone-like nodules formed and native bone tissue. Bone formation by osteoblasts (OB) is a dynamic process, involving the differentiation of progenitor cells, ECM production, mineralisation and subsequent tissue remodelling. 

Cooper GS, Dooley MA, Treadwell EL, et al. Hormonal, environmental, and infectious risk factors for developing systemic lupus erythematosus. Arthritis Rheum 1998 41 1714-1724. 

Autoimmunity. Autoimmune diseases are disorders of immune regulation in which several different factors (e.g. viral, genetic, hormonal, environmental) may each play a role. Autoimmune diseases may belong to any of the four Coombs and Cell classifications of hypersensitivity and include the production of autoantibodies, destructive inflammatory cell infiltrates in various organs, and deposition of immune complexes in vascular beds. Chemically induced autoimmunity may result from any of several possible mechanisms. These include the alteration or release of autoantigens, or the cross-reaction of the chemical with autoantigens, or alternatively a direct effect on the immune system via lymphocytes or macrophages (60). 

Chemiluminescence has been studied extensively (2) for several reasons (/) chemiexcitation relates to fundamental molecular interactions and transformations and its study provides access to basic elements of reaction mechanisms and molecular properties (2) efficient chemiluminescence can provide an emergency or portable light source (J) chemiluminescence provides means to detect and measure trace elements and pollutants for environmental control, or clinically important substances (eg, metaboHtes, specific proteins, cancer markers, hormones, DNA) and (4) classification of the hioluminescent relationship between different organisms defines their biological relationship and pattern of evolution. 

Applications. Immunoassays are used in many different disciplines, having clinical, industrial, agricultural, and environmental appHcations. This technique has made possible rapid analysis of such varied analytes as vimses, toxins, hormones, foreign proteins, dmgs, and insecticides. 

Appraisal of Test Methods for Sex-Hormone Disrupting Chemicals. OECD Environmental Elealth... 

Figure 1 The major hormones involved in growth and funetion of the fetal/neonatal testis illustrating how exogenous, environmental oestrogens eould disrupt the normal balanee of these meehanisms.

Table 2 Some environmental ehemieals with the ability to mimie hormones in vitro and in...

Natural or synthethic receptor ligands that induce a conformational change (active conformation) and a signal transduction process upon receptor binding. Agonists may act as typical hormones or neurotransmitters or they may confer paracrine functions, recognize bacterial, viral or other environmental constituents via activating their dedicated receptors. 

Cellular phenotypes and their responses to environmental, hormonal, and growth-promoting stimuli depend... 

Crain DA, Noriega N, Vonier PM, et al. 1998. Cellular bioavailability of natural hormones and environmental contaminants as a function of serum and cystolic binding factors. Toxicol Ind Health 14(l/2) 261-273. 

GuiUette, L.J., Jr., Gross, T.S., and Masson et al. (1994). Developmental abnormalities of the gonad and abnormal sex hormone concentrations in juvenile alligators from contaminated and control lakes in Florida. Environmental Health Perspectives 102, 680-688. 

Kelce, W.R., Monosson, E., and Gamcsik, M.P. et al. (1994). Environmental hormone disrupters—evidence that Vinclozolin developmental toxicity is mediated by antiandrogenic metabolites. Toxicology and Applied Pharmacology 126, 276-285. 

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