RESUMEN
We studied how patient beliefs regarding the need for antibiotics, as measured by expectation scores, and antibiotic prescribing outcome affect patient satisfaction using data from 2,710 urgent-care visits. Satisfaction was affected by antibiotic prescribing among patients with medium-high expectation scores but not among patients with low expectation scores.
RESUMEN
The relationship between mercury (Hg) and selenium (Se) toxicity is complex, with coexposure reported to reduce, increase, and have no effect on toxicity. Different interactions may be related to chemical compound, but this has not been systematically examined. Our goal was to assess the interactive effects between the two elements on growth in the nematode Caenorhabditis elegans, focusing on inorganic and organic Hg (HgCl2 and MeHgCl) and Se (selenomethionine, sodium selenite, and sodium selenate) compounds. We utilized aqueous Hg/Se dosing molar ratios that were either above, below, or equal to 1 and measured the internal nematode total Hg and Se concentrations for the highest concentrations of each Se compound. Observed interactions were complicated, differed between Se and Hg compounds, and included greater-than-additive, additive, and less-than-additive growth impacts. Biologically significant interactions were only observed when the dosing Se solution concentration was 100-25,000 times greater than the dosing Hg concentration. Mitigation of growth impacts was not predictable on the basis of internal Hg/Se molar ratio; improved growth was observed at some internal Hg/Se molar ratios both above and below 1. These findings suggest that future assessments of the Hg and Se relationship should incorporate chemical compound into the evaluation.
Asunto(s)
Caenorhabditis elegans/efectos de los fármacos , Caenorhabditis elegans/crecimiento & desarrollo , Mercurio/toxicidad , Selenio/toxicidad , Animales , Interacciones Farmacológicas , Contaminantes Ambientales/toxicidad , Cloruro de Mercurio/toxicidad , Mercurio/administración & dosificación , Ácido Selénico/toxicidad , Selenio/administración & dosificación , Selenometionina/toxicidad , Selenito de Sodio/toxicidadRESUMEN
Molecular dynamics (MD) simulations of phosphatidylinositol (4,5)-bisphosphate (PIP2) and phosphatidylinositol (3,4,5)-trisphosphate (PIP3) in 1-palmitoyl 2-oleoyl phosphatidylcholine (POPC) bilayers indicate that the inositol rings are tilted approximately 40 degrees with respect to the bilayer surface, as compared with 17 degrees for the P-N vector of POPC. Multiple minima were obtained for the ring twist (analogous to roll for an airplane). The phosphates at position 1 of PIP2 and PIP3 are within an Angström of the plane formed by the phosphates of POPC; lipids in the surrounding shell are depressed by 0.5-0.8 A, but otherwise the phosphoinositides do not substantially perturb the bilayer. Finite size artifacts for ion distributions are apparent for systems of approximately 26 waters/lipid, but, based on simulations with a fourfold increase of the aqueous phase, the phosphoinositide positions and orientations do not show significant size effects. Electrostatic potentials evaluated from Poisson-Boltzmann (PB) calculations show a strong dependence of potential height and ring orientation, with the maxima on the -25 mV surfaces (17.1 +/- 0.1 A for PIP2 and 19.4 +/- 0.3 A for PIP3) occurring near the most populated orientations from MD. These surfaces are well above the background height of 10 A estimated for negatively charged cell membranes, as would be expected for lipids involved in cellular signaling. PB calculations on microscopically flat bilayers yield similar maxima as the MD-based (microscopically rough) systems, but show less fine structure and do not clearly indicate the most probable regions. Electrostatic free energies of interaction with pentalysine are also similar for the rough and flat systems. These results support the utility of a rigid/flat bilayer model for PB-based studies of PIP2 and PIP3 as long as the orientations are judiciously chosen.
Asunto(s)
Simulación por Computador , Membrana Dobles de Lípidos/química , Modelos Químicos , Fosfatidilcolinas/química , Fosfatidilinositol 4,5-Difosfato/química , Fosfatos de Fosfatidilinositol/química , Cloruros/química , Modelos Moleculares , Sodio/química , Electricidad Estática , Propiedades de Superficie , Factores de TiempoRESUMEN
A 2-year-old, purebred Holstein heifer with exercise intolerance and cardiovascular compromise was diagnosed at postmortem with tetralogy of Fallot, which typically results in death within a few months of life. Survival past the age of 2 was unexpected. The concurrent endocarditis of the pulmonic valve is discussed.