Erythromycin and gallbladder motor function.
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Biomedical subjects
Publications and source records attributed to D Festi.
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It has been recently shown that the newest hypocholesterolemic agent, simvastatin, lowers the biliary cholesterol saturation index and that its association with ursodeoxycholic acid renders it more effective. To determine the mechanism by which simvastatin decreases the biliary cholesterol saturation index, we evaluated hepatic secretion rates of cholesterol, bile acids and phospholipids, and cholic acid pool size, turnover and synthesis in eight hyperlipidemic patients (five women and three men, age range = 38 to 65 yr). These assessments were conducted before treatment, after 4 wk of simvastatin (40 mg/day), after 4 wk of ursodeoxycholic acid (600 mg/day) and after a further 4 wk of a combination therapy of simvastatin (40 mg/day) plus ursodeoxycholic acid (600 mg/day). The cholesterol saturation index was significantly reduced with simvastatin (from 1.51 +/- 0.10 to 0.94 +/- 0.05, mean +/- S.E.; p less than 0.02), with ursodeoxycholic acid (from 1.51 +/- 0.10 to 0.86 +/- 0.03, mean +/- S.E.; p less than 0.02) and with the combination of simvastatin plus ursodeoxycholic acid (from 1.51 +/- 0.01 to 0.70 +/- 0.05, p less than 0.02). The cholesterol saturation index during combination therapy was significantly lower (p less than 0.02) than that reached during the use of simvastatin and ursodeoxycholic acid. Both simvastatin and ursodeoxycholic acid significantly reduced the hepatic secretion rate of cholesterol (from 130 +/- 14 mumols/hr to 81 +/- 12 mumols/hr, p less than 0.01, and 70 +/- 9 mumols/hr, p less than 0.01) without affecting bile acid and phospholipid outputs.(ABSTRACT TRUNCATED AT 250 WORDS)
Several factors are involved in the development of gallstone formation: formation of supersaturated bile; nucleation; formation, retention and adhesion of cholesterol crystals and eventually stone growth. The dynamics of the gallbladder may play a key role in the overall process. The pathophysiologic theory of cholesterol gallstone formation and the knowledge of their physico-chemical properties support the modern concept of gallstone therapy. Chenodeoxycholic and ursodeoxycholic have been widely used as cholesterol gallstone dissolving agents and evaluated in terms of efficacy and safety.
Hepatic uptake and biliary secretion have been evaluated in the isolated perfused rat liver for cholic, chenodeoxycholic, ursodeoxycholic acid, both free and taurine-conjugated; the physicochemical properties of the bile acids have also been calculated and related to these experimental parameters. Cholic acid disappearance rate from the perfusate was the fastest, followed by that of ursodeoxycholic and chenodeoxycholic; it was also faster for taurine-conjugated bile acids than for their respective unconjugated forms. The recovery in bile was higher for conjugated than for unconjugated bile acids, and among each class, was higher for cholic than for chenodeoxycholic and ursodeoxycholic. The hepatic uptake correlated negatively (r = -0.99) with the bile acid lipophilicity, while the biliary secretion correlated with the solubility of the molecules. These results show the effect of the physicochemical properties of BA on their hepatic handling, at the physiological concentration of BA in the portal blood.
The intestinal absorption of bile acids (BA) with different chemical structure has been evaluated in the rabbit, after intestinal infusion of different concentrations (0.25-30 mM) of BA, by mesenteric blood sampling. Cholic (CA), chenodeoxycholic (CDCA), ursodeoxycholic (UDCA) acid, free and taurine (T-) conjugated, together with glycocholic (GCA) acid and deoxycholic acid (DCA) were studied. The apparent uptake parameters were calculated. All conjugated BA showed active transport (T max, nmol min-1 cm-1 int.), with Tmax values in the following order: TCA > TUDCA > TCDCA; unconjugated BA showed passive uptake, with values in the following order: DCA > CDCA > UDCA > CA. GCA and CA showed both passive uptake and active transport. For all BA studied the % uptake in the ileal segment considered was less than 10%, BA uptake being thus limited by transport and/or diffusion kinetics, rather than by flow velocity. The liquid resistance to BA radial diffusion inside the lumen was evaluated, and the infusate-to-blood uptake parameters corrected for it, in order to get the uptake parameters from the epithelium-to-liquid interface to mesenteric blood: the apparent Km decreased, passive uptake coefficient increased, while Tmax was unchanged. The passive component of the uptake, corrected for the luminal resistance, correlated with the BA hydrophobicity (r = 0.963; P < 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)
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Obesity is a condition associated with an increased frequency of gallstone disease. This study attempted to evaluate the comparative effects of two gallstone-dissolving agents, chenodeoxycholic acid and ursodeoxycholic acid, on bile acid metabolism and biliary lipid secretion in obese subjects in order to identify the bile acid of choice in preventing and treating gallstone disease in obesity. Twenty obese subjects (greater than 120% ideal body wt) were randomly treated with ursodeoxycholic acid (10 mg.kg-1.day-1.1 mo-1) and then with chenodeoxycholic acid (15 mg.kg-1.day-1.1 mo-1) or with chenodeoxycholic acid first and then with ursodeoxycholic acid. Patients 1-10 were studied while eating an unrestricted weight-maintenance diet, whereas patients 11-20 were eating a 1080-kcal/d hypocaloric diet. Biliary lipid composition, cholesterol saturation index, and biliary bile acid pattern were evaluated in all subjects before and after each treatment period; in subjects 6-10 and 16-20, biliary lipid secretion rates and bile acid pool size were also evaluated. Both ursodeoxycholic acid and chenodeoxycholic acid decreased cholesterol outputs and cholesterol saturation index. However, during the weight-maintenance period the decrease induced by chenodeoxycholic acid was not significant. Biliary cholesterol outputs and cholesterol saturation index were always lower during ursodeoxycholic acid administration than during chenodeoxycholic acid therapy. Ursodeoxycholic acid levels during ursodeoxycholic acid administration and chenodeoxycholic acid levels during chenodeoxycholic acid administration increased in bile to 50% and 77%, respectively, of total bile acid levels. Bile acid pool size remained unchanged during chenodeoxycholic acid administration and was significantly reduced by ursodeoxycholic acid administration during the weight-reduction period. In conclusion, ursodeoxycholic acid in obese subjects seems more effective than chenodeoxycholic acid, at least during weight maintenance, in reducing cholesterol saturation of bile. This effect is related to a significant decrease of biliary cholesterol output.
Gallbladder motility was evaluated by ultrasonography in 75 cholesterol gallstone patients and in 77 matched control subjects. All 75 gallstone patients were candidates for oral bile acid therapy (radiolucent gallstones, less than 2 cm in diameter, in well-opacified gallbladder), and 38 of them were also studied during ursodeoxycholic acid administration. An additional 20 gallstone patients were studied 1 year after confirmed gallstone dissolution with oral bile acids. Gallstone patients showed significantly greater fasting and residual volumes, a decreased percent of gallbladder emptying, but a similar absolute emptying and emptying rate compared with the control subjects. Greater fasting volumes and reduced percents of gallbladder emptying were also found in gallstone-free patients who achieved complete dissolution with oral bile acids. After ursodeoxycholic acid administration, fasting gallbladder volumes were greater, and percents of gallbladder emptying were further decreased than in untreated gallstone patients. In conclusion, greater fasting volumes, and not reduced gallbladder contractility, account for the defective gallbladder function in radiolucent (cholesterol-rich) gallstone patients. This condition is likely to precede, and possibly to promote, gallstone formation because it persists after gallstone dissolution. Ursodeoxycholic acid administration worsens the defect observed in gallstone patients. This finding also suggests, although indirectly, that the expected normalization of cholesterol saturation during oral bile acid administration is not paralleled by an improvement in gallbladder function.
The intestinal absorption of bile acids has so far been studied from the measurement of the biliary secretion after their intestinal infusion. In the present investigation, the ileal absorption capacity for two different bile acids has been evaluated by means of an intestinal perfusion technique and the simultaneous blood drainage from the mesenteric vein corresponding to the isolated loop. Taurocholic acid and unconjugated cholic acid were infused at different concentrations (0.5-10.0 mM), at a flow rate of 4 ml/min/cm intest. Taurocholic acid absorption increased to a maximum with dose, then reaching a plateau, suggesting that a saturable process had taken place. Cholic acid uptake showed a saturable, possibly active, process, together with a nonsaturable one. These results are consistent with the physicochemical properties of the two bile acids. The technique seems so far suitable for the study of the intestinal absorption of substances undergoing the enterohepatic circulation, since it provides a direct measure of the absorbed fraction, without any distortion arising from the hepatic uptake and biliary secretion.
Gemfibrozil, like clofibrate, is effective in lowering both serum cholesterol and triglycerides and in increasing high-density lipoproteins. The information available about its effects on biliary lipids is still limited, and conflicting results have been reported. In this study we evaluated the effect of gemfibrozil (1.2 g/day) and clofibrate (2.0 g/day), in a single-blind crossover design for 6 weeks with a 4-week washout period, on the biliary cholesterol saturation index (SI) in stimulated hepatic bile and on the hepatic secretion rate of biliary lipids in patients with hyperlipidemia. Clofibrate increased cholesterol SI (from 1.70 +/- 0.14 to 2.05 +/- 0.24), whereas gemfibrozil decreased it (from 1.70 +/- 0.14 to 1.54 +/- 0.16). The results were not statistically significant. The hepatic secretion rate of cholesterol was significantly (p less than 0.04) increased by clofibrate therapy, whereas it was significantly (p less than 0.04) decreased after gemfibrozil; a significant (p less than 0.04) decrease in the hepatic secretion rate of bile acids, bile acid pool size, and bile acid fecal excretion (p less than 0.04) was also found after gemfibrozil administration. Gemfibrozil interferes extensively with bile acid metabolism, but it does not increase biliary cholesterol secretion, as clofibrate does. These results suggest that gemfibrozil does not seem to increase the risk of gallstone formation in patients with hyperlipidemia.
Inter and intra-observer agreement in classifying the presence of gallstones by ultrasonographic images according to established criteria was studied. A film recording of 50 routine ultrasonographic examinations of the gallbladder was read by each of the 46 observers who participated in the Multicenter Italian Study on Epidemiology of Cholelithiasis (M.I.COL.). The overall Kappa score for inter-observer agreement was 0.649, while intra-observer agreement was "good" or "excellent" (Kappa scores greater than 0.60) in 75% of the observers. No statistical difference for inter-observer agreement between "novices" and "expert" echographers was found in the overall Kappa statistic or in category-specific Kappa scores (gallstone, no gallstone, doubtful and inconclusive examinations) The present study suggests that the development of explicit criteria by a group of trained echographers does not eliminate inter- and intra-observer disagreement in categorizing subjects for gallbladder stones.
Ursodeoxycholic acid (UDCA) has been reported to improve liver function tests when administered to patients with cholestatic liver diseases, such as primary biliary cirrhosis (PBC). However, its effects on biliary lipid metabolism in patients with PBC are still unknown. In this study we report the effect that UDCA (600 mg/day, for four weeks) had on biliary cholesterol saturation index, biliary bile acid pattern and pool size, and biliary lipid output in seven female patients (ages 34-58 years) with PBC, stages I to III. A significant improvement of liver function tests was observed after four weeks of treatment. Saturation index was significantly decreased from 1.23 +/- 0.1 to 0.7 +/- 0.08 (P less than 0.02); this effect was due to the significant decrease of biliary cholesterol concentration from 6.7 +/- 0.36 to 3.6 +/- 0.37 percent molar (P less than 0.02). A significant decrease of cholesterol output (from 88 +/- 9 to 55 +/- 10 mumol/hr, P less than 0.02) was also observed. The amount of cholic acid, the predominant bile acid in bile, significantly decreased (from 47.3 +/- 3.5 to 35.4 +/- 2.6 percent molar, P less than 0.02), as did amounts of chenodeoxycholic and deoxycholic acids, while the amount of UDCA rose from 1.6 +/- 1.0 to 34.0 +/- 1.3 percent molar (P less than 0.02). Total bile acid pool size was not affected by UDCA, but the evaluation of individual bile acid pool sizes showed an increased proportion of UDCA relative to the endogenous bile acids.(ABSTRACT TRUNCATED AT 250 WORDS)
Recurrence is a major problem in the medical treatment of gallstones but its extent is still uncertain. The aim of this study was to determine the magnitude of this event and to assess the effectiveness of a postdissolution treatment in preventing it. We evaluated the long-term recurrence rate after 96 confirmed dissolutions observed in 86 subjects (71 women, 15 men) over a 12-yr follow-up period. A low-dose postdissolution treatment (ursodeoxycholic acid, 300 mg/day) was administered to 36 subjects, whereas in the remaining 60 cases no postdissolution treatment was given. By actuarial life-table analysis, the cumulative proportion of gallstone recurrence was 12.5% at the first year, rising to 61% at the 11th year. Postdissolution treatment was effective in reducing the frequency of gallstone recurrence (p = 0.0067), but this was mainly related to its effect on younger subjects (less than or equal to 50 yr old). In older subjects the recurrence rate was unaffected by treatment. The probability of gallstone recurrence was significantly higher in subjects with multiple stones before dissolution treatment than in those who had had solitary stones (p = 0.0091). No other factor predictive of gallstone recurrence could be identified.
Fourteen lesions (nine hepatocellular carcinomas, four hepatic metastases from gastric carcinoma, and one peritoneal metastasis from transitional cell carcinoma) in 12 patients were treated with percutaneous injection of 95% ethyl alcohol under guidance with ultrasound. Requirements for this procedure included inadequate response to conventional treatment or refusal of surgery, easy identification of the tumor with sonography, and a tumor diameter less than 4 cm. Three to nine administrations (75 in all) were performed for each lesion according to its size and to the results of the fine needle biopsy. All lesions had posttreatment sonographic structural changes of fibronecrotic degeneration. All lesions less than 3.2 cm in diameter (11 cases) that underwent the final fine needle biopsy were negative for malignant cells and had volume reductions up to 100%. No biochemical changes or untoward clinical sequelae were detected. Percutaneous intratumoral alcohol injection is inexpensive, easy to perform, and potentially valuable in the treatment of selected small neoplastic lesions of the liver and abdomen.
Bile acid fecal excretion and dihydroxy bile acid concentration in the fecal water of patients with large (N = 6) and small (N = 8) ileal resection, colectomy (N = 5), and healthy controls (N = 10) have been studied in order to evaluate the degree of bile acid malabsorption and the occurrence of bile acid diarrhea in intestinal resections of different extent. Bile acid malabsorption was severe in large ileal resections, mild in small ones, and slight in colectomy. The fecal pH seems to be a limiting factor in the occurrence of a bile acid diarrhea, playing a critical role in determining the dihydroxy bile acid solubility in the fecal water. These results seem to suggest that the bile acids may induce water secretion in the colon not only in small but also in large ileal resections.
Serum cholic and chenodeoxycholic acid conjugates were measured in fasting conditions and after meals in 14 patients with bile acid malabsorption due to ileal resection. Mean serum fasting levels of both primary bile acids did not differ from the controls. After meals, serum cholic acid peaks were lower in patients with ileal resection than in control subjects (p less than 0.001), while chenodeoxycholic acid peaks were reduced in colectomised patients (p less than 0.01). In the sera from patients with ileal resection, the glycine/glycine + taurine ratio for cholic and chenodeoxycholic acid increased (p less than 0.001) from morning to evening, and glycine/glycine + taurine ratio for chenodeoxycholic acid was significantly (p less than 0.01) different from the controls in the sera collected in the evening. The results are consistent with the concept of a better intestinal conservation of chenyl, mainly of the glycine conjugated from, than of cholylconjugates, in patients with ileal resection; this is probably because of passive absorption in the intestine. The postprandial peaks of serum cholic acid conjugates may therefore be regarded as a test of ileal dysfunction, while peaks of chenodeoxycholic acid conjugates suggest colonic impairment.
We studied some aspects of bile acid metabolism in 25 patients affected by Gilbert's syndrome, 5 patients with hemolytic anemia, and 25 control subjects in order to assess whether bile acids as well as bilirubin are affected in unconjugated hyperbilirubinemic conditions. We measured serum cholic and chenodeoxycholic acid conjugates fasting and postprandially, the plasma disappearance of intravenously injected cholyl[1-14C]glycine, 14CO2 in breath, and 14C in stools after oral administration of the same isotope. Mean serum fasting level of conjugated cholic acid was significantly reduced in hyperbilirubinemic patients (p less than 0.01) in comparison with the controls, while the postprandial elevation was similar. The cholyl[1-14C]glycine hepatic uptake was faster in the patients with Gilbert's syndrome, but no significant difference was found as far as 14CO2 in breath and 14C in stools were concerned. Additional in vitro studies showed that increasing bilirubin concentrations displace glycocholic acid and, to a lesser extent, glycochenodeoxycholic acid from their binding to albumin, the affinity constant of the latter bile acid being 30 times greater than that of the former one. This competition between bilirubin and bile acids explains the faster hepatic uptake of cholic acid conjugates and hence their lower serum levels in unconjugated hyperbilirubinemic conditions. In addition, low levels of cholic acid conjugates, together with normal serum chenodeoxycholic acid conjugate levels, discriminate Gilbert's syndrome from other causes of hyperbilirubinemia.
To test whether long-term oral dosage with chenodiol (chenodeoxycholic acid) used for dissolution of cholesterol gallstones would cause impairment of small-intestinal structuree or function, ten patients were studied before and after three months of oral chenodiol administration, 15 mg/kg of body weight per day. Small-intestinal structure was assessed by roentgenogram and intestinal biopsy, using both light and electron microscopy. Small-intestinal function was assessed by xylose, fat and vitamin B12, lactose, and bile-acid absorption. Bile acid metabolism was also characterized by the breath test for deconjugation using carbon dioxide labeled with radioactive carbon 14. No significant abnormalities were found. The results suggest that oral chenodiol administration does not impair intestinal structur or function in doses used for gallstone dissolution.