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Background: Symptom relief post pneumatic dilation is traditionally used to assess treatment success in achalasia patients. Recently, we showed that symptom relief and objective oesophageal emptying are concordant in about [...]

Cortisol mediates physiological adaptations to stressors, including fuel mobilization to support increased energy demands and reduction of energy-expensive processes such as growth or immune function. Long-term stress, however, can be maladaptive since inhibition of important physiological processes cannot be prolonged without serious consequences. Upon encountering a stressor such as catching-&-releasing, fish exhibit rapid (in minutes) and profound (>50-fold) surges in plasma cortisol that are sustained so long as the stressor remains. Cortisol returns toward baseline at a rate that differs among species, regulated in part by metabolizing enzymes that inactivate cortisol, e.g., 11beta-hydroxysteroid dehydrogenase-type-2 (11-beta-HSD-2). The cortisol surge affects endocrine regulators of tissue growth & repair. An insulin-like growth factor-binding protein (IGFBP) is increased by cortisol and in several physiological conditions in which cortisol is elevated and growth is inhibited. The consistent presence of the IGFBP in growth-inhibited fish suggests its utility as a biomarker of the growth impacts of stress. Importantly, the IGFBP may remain elevated even after the cortisol surge has subsided, suggesting that the physiological impacts ofcortisol outlast its initial stress-induced surge. Thus, the nature of the stress response itself (e.g., role of 11[beta]-HSD-2) and its secondary effects (e.g., on growth) are significant considerations when assessing the biological impacts of catch-&-release or other stressors. [Funded by CA Sea Grant College Prog. NOAA NA06RG042 2002-03, proj. # R/F-192, & NSF grant IBN0115975.]

Multicellular animals, which evolved about 700 to 1000 myr ago, contain many of the genes found in yeast and other protists. Important and necessary for the evolution of multicellular animals was the evolution of new pathways for intercellular signaling that regulated more complex physiological responses. We focus on the contribution to this process of lipophilic molecules that interact with nuclear receptors and the aryl hydrocarbon receptor. Members of both gene families are found in invertebrates and vertebrates. We propose that environmental chemicals have been an important influence on the evolution of multicellular animals by providing a selective pressure for the evolution of proteins that signal the presence of these chemicals in the environment and enzymes that detoxify these chemicals. In some cases xenobiotics were recruited as signals that regulated differentiation and development. Indeed, this cooption of xenobiotic swords into adaptive plowshare signals contributed to the diverse physiology found in multicelluar animals.