MR arthrography: impact of steroids, local anesthetics, and iodinated contrast material on gadolinium signal intensity in phantoms at 1.5 and 3.0 T.

Purpose: To determine if gadolinium signal intensity at direct magnetic resonance (MR) arthrography is affected by the addition of steroids, anesthetics, or iodinated contrast material.

Materials And Methods: This study did not require approval by the institutional review board because no patients or patient data were involved. An in vitro study was performed to evaluate various concentrations of three gadolinium contrast agents (gadopentetate dimeglumine, gadobenate dimeglumine, and gadofosveset trisodium) diluted in either saline or iodinated contrast material (50% and full-strength iohexol 300).

Evidence against the involvement of oxidative stress in fatty acid inhibition of insulin secretion.

Prolonged exposure to elevated levels of fatty acids adversely affects pancreatic beta-cell function. Here we investigated 1) whether ceramide synthesis, which we reported to mediate fatty acid inhibition of insulin gene expression, also inhibits insulin secretion and 2) whether fatty acid inhibition of insulin secretion involves the generation of reactive oxygen species (ROS), nitric oxide (NO), or prostaglandin E(2) (PGE(2)). A 72-h culture of islets in the presence of palmitate or oleate resulted in a marked decrease in glucose-induced insulin release assessed in 1-h static incubations.