Calmodulin regulation of gallbladder ion transport becomes dysfunctional during gallstone formation in prairie dogs.

Gallbladder absorption is increased prior to gallstone formation in prairie dogs and may promote cholesterol crystallization. Recent studies indicate that Ca2+-calmodulin (CaM) tonically inhibits gallbladder electrolyte absorption in prairie dogs fed a nonlithogenic diet. We hypothesized that dietary cholesterol alters CaM-dependent regulation of gallbladder ion transport, a possible link between increased gallbladder absorption and gallstone formation.

Endogenous prostaglandins modulate chloride secretion by prairie dog gallbladder.

In addition to concentrating bile, the gallbladder secretes chloride (Cl-) and mucus into its lumen. We recently observed that gallbladder Cl- secretion is increased in prairie dogs during the formation of cholesterol crystals, a period of altered mucosal prostaglandin synthesis. Pathologic Cl- secretion is characteristic of other epithelial disorders such as cystic fibrosis and hypercalciuric nephrolithiasis and may be important in gallstone pathogenesis.

Octreotide stimulates Ca++ secretion by the gallbladder: a risk factor for gallstones.

Background: Gallstone formation during octreotide therapy has been linked to elevated levels of gallbladder bile Ca++, a well-known prolithogenic factor. Although the subcutaneous administration of octreotide raises gallbladder bile Ca++ in prairie dogs, the mechanism for this effect is unknown. Octreotide has been shown to increase gallbladder Na+ and water absorption in Ussing chamber studies.

Redesigning the surgery clerkship at MCP Hahnemann School of Medicine to address the educational needs of generalists.

This article describes how the surgery clerkship at MCP Hahnemann School of Medicine was redesigned to provide all students a well-rounded general professional education and to address the specific educational needs of generalists. During the 12-week clerkship, students spend eight weeks on two different general surgery rotations, which include significant experiences in outpatient settings. The evaluation and management of common general surgical problems, as well as the holistic approach to patient care, are emphasized.

Elevated biliary calmodulin during gallstone formation: the role of bile acids.

Hepatic bile synthesis is altered during experimental gallstone formation. In response to cholesterol, there is a hydrophobic shift in hepatic bile acid synthesis and hypersecretion of phospholipids. These changes decrease the vesicular capacity for cholesterol and favor crystallization.