Ursodeoxycholic acid exerts no beneficial effect in patients with symptomatic gallstones awaiting cholecystectomy.

Ursodeoxycholic acid (UDCA) and impaired gallbladder motility purportedly reduce biliary pain and acute cholecystitis in patients with gallstones. However, the effect of UDCA in this setting has not been studied prospectively. This issue is important, as in several countries (including the Netherlands) scheduling problems result in long waiting periods for elective cholecystectomy.

Pharmacological manipulation of biliary water and lipids: potential consequences for prevention of acute biliary pancreatitis.

Acute biliary pancreatitis, caused by macroscopic cholesterol gallstones or microlithiasis, is often a severe disease with considerable morbidity and mortality. Formation of cholesterol gallstones and microlithiasis is caused by cholesterol crystallization from cholesterol supersaturated gallbladder bile. Particularly patients with fast and extensive crystallization, due to highly concentrated bile, low biliary phospholipid contents and gallbladder mucin hypersecretion seem at risk for pancreatitis.

Drugs affecting biliary lipid secretion and gallbladder motility: their potential role in gallstone treatment and prevention.

Gallstone disease in the Western world has an estimated prevalence of 10-15% and more than 75% are cholesterol-enriched gallstones. Defective gallbladder motility has been identified as an important pathogenic factor for cholesterol gallstone disease. Various agents may enhance or impair postprandial gallbladder motility, and their effects on interdigestive gallbladder and intestinal motility should also be taken into account.

Small gallstones, preserved gallbladder motility, and fast crystallization are associated with pancreatitis.

Acute pancreatitis is a severe complication of gallstones with considerable mortality. We sought to explore the potential risk factors for biliary pancreatitis. We compared postprandial gallbladder motility (via ultrasonography) and, after subsequent cholecystectomy, numbers, sizes, and types of gallstones; gallbladder bile composition; and cholesterol crystallization in 21 gallstone patients with previous pancreatitis and 30 patients with uncomplicated symptomatic gallstones.

Effects of hydrophobic and hydrophilic bile salts on gallstone growth and dissolution in model biles.

Unlabelled: Cholesterol crystallization is a prerequisite for gallstone formation and growth, whereas dissolution of crystallized cholesterol forms the basis of nonsurgical therapy. Crystallization has been studied in detail, but dissolution mechanisms and effects of gallstones are largely unknown.

Methods: We evaluated gallstone growth or dissolution, cholesterol crystallization and lipid distribution into various phases, in model biles with low or intermediate phospholipid contents (crystal-containing left two-phase or central three-phase zones), and with high phospholipid or low cholesterol contents (crystal-free right two-phase or bottom one-phase zones).

Smooth muscle function and dysfunction in gallbladder disease.

The gallbladder epithelium and smooth muscle layer are exposed to concentrated biliary solutes, including cholesterol and potentially toxic hydrophobic bile salts, which are able to influence muscle contraction. Physiologically, gallbladder tone is regulated by spontaneous muscle activity, hormones, and neurotransmitters released into the muscle from intrinsic neurons and extrinsic sympathetic nerves. Methods to explore gallbladder smooth muscle function in vitro include cholecystokinin (CCK) receptor-binding studies and contractility studies.

Micturition is associated with phase III of the interdigestive migrating motor complex in man.

Objectives: In previous manometric studies, we observed that micturition was associated with phase III of the migrating motor complex. The present study aimed to objectify this possible relationship and to examine whether modulation of micturition frequency influences migrating motor complex phase III incidence.

Methods: In a retrospective study, ambulatory antroduodenal manometry and micturition data of 27 subjects were analyzed.

Effects of hydrophobic and hydrophilic bile salt mixtures on cholesterol crystallization in model biles.

Unlabelled: The hydrophilic bile salt ursodeoxycholate is frequently used to dissolve cholesterol gallstones. We have now quantitated crystallization as a function of bile salt hydrophobicity, phospholipid content, cholesterol saturation and total lipid concentration (TLCo).

Methods: Crystallization in supersaturated model biles with low phospholipid contents (left two-phase-micelles and crystal-containing-zone) was assessed during 21 days by microscopy and chemical measurement of crystal mass.

Incorporation of cholesterol in sphingomyelin- phosphatidylcholine vesicles has profound effects on detergent-induced phase transitions.

Vesicle <--> micelle transitions are important phenomena during bile formation and intestinal lipid processing. The hepatocyte canalicular membrane outer leaflet contains appreciable amounts of phosphatidylcholine (PC) and sphingomyelin (SM), and both phospholipids are found in the human diet. Dietary SM enrichment inhibits intestinal cholesterol absorption.

Quantitation of cholesterol crystallization from supersaturated model bile.

Cholesterol crystallization is an essential step in gallstone formation. Although spectrophotometry and nephelometry have been used for quantitation of crystallization, potential effects of crystal size and shape have not been evaluated. We determined crystallization in model biles [total lipid concentration 7.