Male reproductive health and environmental xenoestrogens

EHP is a publication of the U.S. government. Publication of EHP lies in the public domain and is therefore without copyright. Research articles from EHP may be used freely; however, articles from the News section of EHP may contain photographs or figures copyrighted by other commercial organizations and individuals that may not be used without obtaining prior approval from both the EHP editors and the holder of the copyright. Use of any materials published in EHP should be acknowledged (for example, "Reproduced with permission from Environmental Health Perspectives") and a reference provided for the article from which the material was reproduced.Male reproductive health has deteriorated in many countries during the last few decades. In the 1990s, declining semen quality has been reported from Belgium, Denmark, France, and Great Britain. The incidence of testicular cancer has increased during the same time incidences of hypospadias and cryptorchidism also appear to be increasing. Similar reproductive problems occur in many wildlife species. There are marked geographic differences in the prevalence of male reproductive disorders. While the reasons for these differences are currently unknown, both clinical and laboratory research suggest that the adverse changes may be inter-related and have a common origin in fetal life or childhood. Exposure of the male fetus to supranormal levels of estrogens, such as diethlylstilbestrol, can result in the above-mentioned reproductive defects. The growing number of reports demonstrating that common environmental contaminants and natural factors possess estrogenic activity presents the working hypothesis that the adverse trends in male reproductive health may be, at least in part, associated with exposure to estrogenic or other hormonally active (e.g., antiandrogenic) environmental chemicals during fetal and childhood development. An extensive research program is needed to understand the extent of the problem, its underlying etiology, and the development of a strategy for prevention and intervention.Supported by EU Contract BMH4-CT96-0314

Viral-Mediated Gene Therapy for the Generation of Artificial Insulin-Producing Cells as a Therapeutic Treatment for Type 1 Diabetes Mellitus

Over the past decade, several approaches have been employed to develop cell and gene therapy strategies that generate artificial insulin-producing cells (IPCs) for potential therapeutic applications in the treatment of type 1 diabetes mellitus (T1D) . The genetic engineering of functional IPCs necessitates a broad understanding of the pancreatic developmental process and the β cell transcription factors that govern mature β cell differentiation and function. To successfully obtain functional IPCs, the type of vectors utilised for gene transfer and the selection of a suitable target cell for subsequent differentiation into IPCs is of fundamental importance. Techniques for manufacturing IPCs include the dedifferentiation and directed transdifferentiation of autologous or allogeneic cells ex vivo followed by transplantation and the in vivo transdifferentiation of target tissue via viral gene transfer. Ultimately, the goal is to construct IPCs that have the capacity to process, store and secrete insulin in response to fluctuating blood glucose levels, whilst avoiding the administration of immunosuppressants and recurrent autoimmune destruction, thereby indefinitely restoring normoglycaemia