Ontogeny of the oestrogen receptors ESR1 and ESR2 during gonadal development in the tammar wallaby, Macropus eugenii.

Oestrogen has wide ranging effects in development mediated mainly via the two oestrogen receptors, alpha (ESR1, also known as ERalpha) and beta (ESR2, also known as ERbeta). Oestrogen is the key factor that directs the indifferent gonad to become an ovary in many non-mammalian vertebrates. Oestrogen is not required for early ovarian differentiation in mammals but can disrupt normal testicular development in eutherians. Surprisingly, exogenous oestrogen can cause sex reversal of an XY gonad in two marsupials, the North American opossum and the tammar wallaby. To understand the mechanism by which oestrogen induces sex reversal, we characterised the genes for ESR1 and ESR2 and examined their expression during gonadal differentiation in the tammar wallaby, Macropus eugenii. Both receptors were expressed in the somatic cells and germ cells of the indifferent gonad in both XX and XY foetuses throughout all stages of development, and persisted in these cells into adulthood. ERs were also present in many other tissues including kidney, pituitary and mammary gland. ER mRNA was not significantly altered by exogenous oestrogen in cultured XY gonads but the receptors translocated to the nucleus in its presence. These findings confirm that there is conserved expression of the ERs in the indifferent gonad despite the lack of available ligand during early gonadal development. The receptors can respond to exogenous estrogen at this early stage and are capable of transducing signals in the early mammalian gonad. However, the selective forces that maintained conserved ER expression in this tissue remain unknown.

The development of the National Reporting and Learning System in England and Wales, 2001-2005.

In 2001, the National Patient Safety Agency (NPSA) was created as part of a wider reform process to improve quality of care for patients in the National Health Services of England and Wales. The NPSA was charged with developing and implementing a national system for collecting and learning from reported patient safety incidents. Between 2003 and 2005, 303 447 incidents were reported from a wide range of health care settings. As a result, a range of interventions have been developed to improve safety. A number of lessons have been distilled from the experience of England and Wales, including that: clinical risk management system characteristics should be aligned with those of the national reporting system; and safety culture and information dissemination must be addressed at the same time as any new reporting system is implemented. These lessons should be of use to other countries implementing similar patient safety strategies.