Ventricular Arrhythmias and Sudden Death Following Percutaneous Pulmonary Valve Implantation in Pediatric Patients.

Reports have suggested a transient increase in ventricular ectopy early after percutaneous pulmonary valve implantation (PPVI). Little is known about the potential for more serious ventricular arrhythmias (VA) in children who undergo PPVI. We sought to evaluate the incidence of severe VA following PPVI in a pediatric population and to explore potential predictive factors.

Ghrelin in the summer flounder: immunolocalization to the gastric glands and action on plasma cortisol levels.

We searched for evidence of the hormone ghrelin in the stomach of a juvenile, marine teleost, the summer flounder. Using antiserum against the conserved core of the ghrelin peptide, immunoreactivity was observed in the simple, branching epithelium that comprises the gastric glands. The immunoreaction was especially strong in the glandular epithelium located deep in the tissue.

Evidence for the onset of feedback regulation of cortisol in larval summer flounder.

We investigated the functional development of feedback regulation of cortisol levels during early development in a marine teleost, summer flounder, using a novel pharmaceutical approach. Larvae were immersed for 4h in the glucocorticoid agonist dexamethasone (20 microM) and/or the glucocorticoid-receptor antagonist RU486 (0.12 microM) at 1, 7, or 21 days after hatching.

Cortisol is necessary for seawater tolerance in larvae of a marine teleost the summer flounder.

Larval-stage summer flounder (Paralichthys dentatus) were immersed in the corticosteroid-receptor blocker RU486 to test the effects of cortisol deficiency on salinity tolerance. Premetamorphic larvae held at 10 (near isosmotic) or 30 (hyperosmotic) parts per thousand ( per thousand) seawater survived well over 5d in 0, 0.012, or 0.

Adaptation for water balance in the partial gastrointestinal tract of summer flounder.

Marine teleosts continually drink and absorb water across the intestine to prevent dehydration. Surprisingly, summer flounder that are missing most of their intestine, due to necrotizing enteritis, maintain osmotic homeostasis. Here, we tested the hypothesis that this remnant gastrointestinal tract undergoes compensatory adaptation for fluid uptake.

Osmoregulatory physiology of pyloric ceca: regulated and adaptive changes in chinook salmon.

Functions of the anatomically obvious, yet peculiar, pyloric ceca of the fish gut have been a source of conjecture for over two millennia since Aristotle hypothesized on digestive utilities. Here, we demonstrate regulated and adaptive changes in osmoregulatory physiology of ceca from chinook salmon (Onchorhynchus tshawytscha). Transfer of salmon from freshwater to seawater (both short- and long-term) significantly stimulated both fluid uptake from 5.

Tissue culture of sockeye salmon intestine: functional response of Na+-K+-ATPase to cortisol.

A method to culture tissue explants of the intestine from freshwater-adapted sockeye salmon (Oncorhynchus nerka) was developed to assess possible direct effects of cortisol on Na(+)-K(+)-ATPase activity. As judged by several criteria, explants from pyloric ceca and the posterior region of the intestine remained viable during short-term (6-day) culture, although Na(+)-K(+)-ATPase activity declined and basolateral components of the enterocytes were observed to be partially degraded. Addition of cortisol to the culture medium maintained Na(+)-K(+)-ATPase activity (over 2-12 days) above that of control explants and, in some cases, was similar to levels before culture.

Temporal changes in intestinal Na+, K(+)-ATPase activity and in vitro responsiveness to cortisol in juvenile chinook salmon.

Seasonal changes in endogenous Na+, K(+)-ATPase activity were measured in pyloric ceca and posterior intestine of juvenile chinook salmon (Oncorhynchus tshawytscha) maintained in fresh water over 18 months. In tissues from these same fish, the in vitro responsiveness of Na+, K(+)-ATPase activity to 10 microg cortisol/ml was assessed. There were pronounced increases in endogenous Na+, K(+)-ATPase activity in summer for both intestinal regions, in underyearlings and yearlings.

Pseudobranch and gill Na(+), K(+)-ATPase activity in juvenile chinook salmon, Oncorhynchus tshawytscha: developmental changes and effects of growth hormone, cortisol and seawater transfer.

The teleost pseudobranch is a gill-like structure often fused to the anterior of the opercular cavity. Pseudobranch cells are mitochondria rich and have high levels of Na(+), K(+)-ATPase activity. In this study, pseudobranch Na(+), K(+)-ATPase activity in juvenile chinook salmon (Oncorhynchus tshawytscha) was compared to gill Na(+), K(+)-ATPase activity, a known marker of parr-smolt transformation, in three experiments.

Cortisol mediates the increase in intestinal fluid absorption in Atlantic salmon during parr-smolt transformation.

We have previously shown in Atlantic salmon that the rate of fluid absorption by the posterior intestine (Jv) is elevated during the smolt stage in spring as a preadaptive development for osmoregulation in seawater. In the present study, we examined developmental differences in the responsiveness of Jv to cortisol and the corticosteroid antagonist, RU 486, through the parr-smolt transformation. Freshwater, juvenile salmon were administered slow-release implants of cortisol (50 micrograms/g body wt), RU 486 (1 mg/g body wt), or the implant without steroid (controls) at seven times from November 1992 through June 1993.

Cortisol stimulates intestinal fluid uptake in Atlantic salmon (Salmo salar) in the post-smolt stage.

The fluid uptake rate of the posterior intestine of salmonids increases during the parr-smolt transformation. Intestinal fluid uptake in post-smolt Atlantic salmon was investigated after treatment with cortisol and growth hormone (GH), alone or together. Two replicate experiments were conducted in August 1991 and August 1992.

Changes in intestinal fluid transport in Atlantic salmon (Salmo salar L) during parr-smolt transformation.

We examined changes in fluid transport by the intestine of Atlantic salmon (Salmo salar L) undergoing parrsmolt transformation during springtime. In vitro measurements of fluid transport rate (Jv) across non-everted middle and posterior intestinal sac preparations were made in late April and early June 1990 and from February through June 1991 for juvenile smolting fish. Intestinal Jv was also compared between parr- and smolt-stage salmon in both years.