The fax-1 nuclear hormone receptor regulates axon pathfinding and neurotransmitter expression.

Specification of neuron identity requires the activation of a number of discrete developmental programs. Among these is pathway selection by growth cones: in order for a neuron's growth cone to respond appropriately to guidance cues presented by other cells or the extracellular matrix, the neuron must express genes to mediate the response. The fax-1 gene of C. elegans is required for pathfinding of axons that extend along the ventral nerve cord. We show that fax-1 is also required for pathfinding of axons in the nerve ring, the largest nerve bundle in the nematode, and for normal expression of FMRFamide-like neurotransmitters in the AVK interneurons. The fax-1 gene encodes a member of the superfamily of nuclear hormone receptors and has a DNA-binding domain related to the human PNR and Drosophila Tailless proteins. We observe fax-1 expression in embryonic neurons, including the AVK interneurons, just prior to axon extension, but after neurogenesis. These data suggest that fax-1 coordinately regulates the transcription of genes that function in the selection of axon pathways, neurotransmitter expression and, perhaps, other aspects of the specification of neuron identity.

Ethical issues and paclitaxel (TAXOL) administration.

Although less concrete than the practical issues involved in the administration of paclitaxel, the ethical concerns are nonetheless important. Anything that elicits the broad range of emotions shown by individuals seeking, receiving, or administering paclitaxel is bound to raise ethical concerns. General ethical principles can be applied to the "paclitaxel experience." It is helpful to look at ethical principles within the context of pressure exerted on caregivers to provide paclitaxel. These pressures include high media profile of the drug, reported drug activity, and environmental issues. The high media profile has led to tremendous public demand, which has in turn influenced access and referral issues. When a new, promising drug is released, it is important for those nurses who have worked with the drug in clinical trials to participate in the transfer of technical information to the community. This must include information designed to sensitize caregivers to the variety of issues and concerns raised in relation to the drug that they provide.

Stress of occupational exposure to blood or body fluids: managing the response.

Education and universal precautions alone may be insufficient to ameliorate the potential crisis situation brought about by fear of occupational exposure to blood or body fluids. The authors discuss typical initial reactions to exposure and propose specific steps to be taken in this initial period prior to the introduction of medical exam and counseling.