March 2008

Offspring of Women Exposed In Utero to Diethylstilbestrol (DES):
A Preliminary Report of Benign and Malignant Pathology in the Third Generation

Background: Animal studies suggest that prenatal exposure to the synthetic estrogen diethylstilbestrol (DES) causes epigenetic changes that may be transmitted to the next generation. Specifically, these studies show an elevated incidence of reproductive tumors in the female offspring of prenatally-exposed mice...

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March 2008

Defining biological communication

This article reviews conflicting definitions of biological communication, splitting them into two groups--adaptationist and information transfer. It holds the adaptationist definition to be superior, arguing that the information transfer definition loses much power by ignoring the dynamic evolutionary context of biology. It suggests as well that the adaptationist definition must consider the adaptation of both the sender and the receiver in order to be effective...

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January 2008

Phytoestrogens and Breast Cancer Prevention: Possible Mechanisms of Action

Phytoestrogens display an array of pharmacological properties, and in recent years
investigation of their potential as anti-cancer agents has increased dramatically. This article will review the published literature related to phytoestrogens and breast cancer as well as suggest the possible mechanisms that may underlie the relationship between phytoestrogens and breast cancer...


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January 2008

Molecular Cloning and Characterization of Estrogen, Androgen, and Progesterone Nuclear Receptors from a Freshwater Turtle

Steroid hormones are essential for the normal function of many organ systems in vertebrates. Reproductive activity in females and males, such as the differentiation, growth, and maintenance of the reproductive system, requires signaling by the sex steroids. Although extensively studied in mammals and a few fish, amphibians, and bird species, the molecular mechanisms of sex steroid hormone (estrogens, androgens, and progestins) action are poorly understood in reptiles...


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January 2008

High Binding Ability of Bisphenol A to Human Estrogen-Related Receptor-γ

Various lines of evidence have shown that bisphenol A acts as an endocrine disruptor when present in very low doses. It was recently demonstrated that BPA binds strongly to human estrogen-related receptor-γ (ERR-γ) in a binding assay using [3H]4-hydroxytamoxifen ([3H]4-OHT). It was also demonstrated that BPA inhibits the deactivation activity of 4-OHT...


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January 2008

Expressing Estrogen-Responsive Genes

Estrogens, upon recruitment of their cognate receptors, govern the expression of target genes. Perillo et al. (p. 202) show that transcription of estrogen-responsive genes is driven by hormone-dependent demethylation of a critical lysine in histone H3 to induce a local oxidative burst that modifies the surrounding DNA by guanine oxidation, which is subsequently removed by specific glycosylases. 8-oxo-guanine-DNA glycosylase 1 and the topoisomerase II enzyme are recruited to these loci and bend the intervening DNA-chromatin region to mark the site where transcription begins and drive expression of estrogen-responsive genes...


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