Lepeophtheirus salmonis: characterization of prostaglandin E(2) in secretory products of the salmon louse by RP-HPLC and mass spectrometry.

Lepeophtheirus salmonis is an ectoparasitic copepod that causes serious disease outbreaks in both wild and farmed salmonids. As the relationship between L. salmonis and its hosts is not well understood, the current investigation was undertaken to investigate whether any immunomodulatory compounds could be identified from secretions of L. salmonis. By incubating live L. salmonis adults with the neurotransmitter dopamine in seawater, we were able to obtain secretions from the parasite. These were analyzed by RP-HPLC column, as well as LC-MS. L. salmonis secretions contained a compound with the same retention time and mass of PGE(2). The identity of this compound as PGE(2) was confirmed by MS-in source dissociation. The concentrations of PGE(2) in L. salmonis secretions ranged from 0.2 to 12.3 ng/individual and varied with incubation temperature and time kept off the host. Prostaglandin E(2) is a potent vasodilator and thought to aid in parasite evasion from host immune responses. This is the first reported evidence of prostaglandin production in parasitic copepod secretions and its implications for the host-parasite relationship are discussed.

A conceptual model of feminine hardiness.

Comprehensive literature reviews of hardiness consistently reveal empirical ambiguities and conceptual limitations. The article describes a grounded theory study focused on the conceptual nature of hardiness. In a group of 13 women with breast cancer, two major characteristics of hardiness emerged: a strong sense of purpose and the ability to endure. These characteristics are described in terms of their internal dimensions, manifestations, and outcomes. The findings are compared with the original conceptualization of hardiness, specifically its attributes of commitment, control, and challenge. The similarities and differences expand, extend, and modify the original definition of hardiness.