Biomedical subjects

B J Pearlman

Publications and source records attributed to B J Pearlman.

3 recordsLinked to original sources

PubMed1979

Gallstone dissolution--a progress report.

Cholesterol gallstone formation occurs in three stages. First, the bile must be saturated with cholesterol, thereby allowing cholesterol crystals to form. Then, nucleation and growth of the gallstone can occur, although little is known about these latter two stages. Therapy for dissolution of gallstones is directed at desaturating the bile. Chenodeoxycholic acid (CDCA), the most extensively tested agent, is successful in dissolving 60 per cent of radiolucent gallstones; however, long-term safety remains to be demonstrated. Ursodeoxycholic acid (UDCA), the 7 beta epimer of CDCA, is a promising agent for cholesterol gallstone dissolution, but it, other potential agents, and dietary manipulations require more extensive study. An important problem, the prevention of recurrence of gallstones after dissolution, also needs resolution. Medical dissolution probably will be applicable as an alternative to cholecystectomy for most patients with radiolucent gallstones, but the specific relative indications remain to be determined. A variety of modalities, both medical and surgical, are being used for the treatment of retained or reformed bile duct stones. These include T-tube infusions, oral CDCA, and extraction either through the T-tube tract or after endoscopic papillotomy. Further studies, including controlled trials, are necessary to determine the relative indications for these methods.

Animals↗

PubMed1979

Cholesterol gallstone formation and prevention by chenodeoxycholic and ursodeoxycholic acids. A new hamster model.

Prior animal models of cholesterol gallstone formation have been criticized for their dissimilarity to the conditions of humans with gallstones. We present a new hamster model of cholesterol cholelithiasis that more closely approximates the human situation. Sixty female Golden Syrian hamsters (average weight 83.2 +/- 3.4 g) were allocated to six groups of 10 animals each. Groups were fed standard diet (containing 0.8 gm cholesterol/g of food) or increased cholesterol diet (containing 2.4 mg cholesterol/g of food), with or without ethinyl estradiol, 15 micrograms/kg/d. Two groups receiving both increased cholesterol and ethinyl estradiol also received either chenodeoxycholic acid or ursodeoxycholic acid, 20 mg/kg/d. The animsl were sacrificed at 12 wk. Cholesterol gallstones (78.3 +/- 5.0% cholesterol by weight) formed in 30% of the animals fed ethinyl estradiol, 50% of those fed increased cholesterol, and 90% of those fed the combination of both. Bile was saturated in all three groups, with the saturation index of the combination group (2.08 +/- 0.17) being the highest. In both groups receiving bile acid therapy, no gallstones were found, and the bile remained unsaturated. For the bile acid-fed groups, both hepatic HMG-CoAR and hepatic cholesterol 7 alpha-hydroxylase activities were reduced (P less than 0.01) when compared to the group fed standard diet and to the grou fed the combination. Thus, a new animal model of cholesterol gallstone formation has been developed in which chenodeoxycholic acid and ursodeoxycholic acid therapy prevented gallstone formation through mechanisms similar to those reported in cholesterol gallstone patients.

Animals↗

PubMed1978

Gallstones. The present and future of medical dissolution.

Adequate concentrations of bile acids and phospholipids are necessary to keep cholesterol in solution in bile. When the amount of cholesterol exceeds the capacity of bile acids and phospholipids to keep the cholesterol in micellar solution, bile becomes supersaturated; then, under appropriate conditions, cholesterol crystals form and gallstones may develop. Current dissolution therapy is aimed at desaturating the bile, thereby shifting the equilibrium of cholesterol from a crystalline phase back toward a micellar state, thus permitting gallstones to dissolve. Chenodeoxycholic acid is the drug being most extensively tested for efficacy in dissolution; at present, it is successful in about 60 per cent of cases. The primary mechanism of action appears to be suppression of biliary secretion of cholesterol. Further experience is needed to confirm the safety of chenodeoxycholic acid, to gain more precision in patient selection, and to determine ideal dose. The role of chenodeoxycholic acid in prophylaxis and in prevention of recurrence needs further study. Other potential agents for dissolution also deserve investigation.

Adult↗