Re: Helicobacter pylori and atrophic gastritis: importance of the cagA status.
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Biomedical subjects
Publications and source records attributed to F Bazzoli.
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BACKGROUND & AIMS: Increasing evidence indicates that inherited susceptibility is important in the pathogenesis of colorectal neoplasia. The aim of this study was to clarify whether having only one first-degree relative with colorectal cancer increases the risk of developing adenomatous polyps and whether total colonoscopy is an appropriate screening measure in these patients. METHODS: The frequency of such a history was evaluated in 397 asymptomatic patients who underwent total colonoscopy. Of these patients, 155 had colorectal polyps and the remaining 242 did not have polyps. RESULTS: Among polyp cases, 27 of 155 (17.4%) had a positive history; among those without polyps, 12 of 242 (5.0%) had a positive history. Alternatively expressed, 27 of 39 patients (69%) with family history and 128 of 358 patients (36%) without family history had adenomas. The estimated risk for polyps associated with family history was 1.9. Among polyp cases, 14 of 27 patients (51.9%) with family history and 32 of 128 patients (25.0%) without family history had only proximal polyps (chi 2 test; P = 0.006; odds ratio, 3.2), In the same groups, frequency of high-grade dysplasia was 8 of 27 patients (29.6%) and 16 of 128 patients (12.5%), respectively (chi 2 test; P = 0.04; odds ratio, 2.9). CONCLUSIONS: Relative to subjects with no family history, asymptomatic patients with one first-degree relative with colorectal cancer had nearly double the risk of developing adenomatous polyps, greater frequency of severely dysplastic lesions, and significantly higher frequency of proximal polyp location. This suggests that total colonoscopy screening is indicated in these subjects.
OBJECTIVES: The appearance of gallstone opacification during oral bile acid administration indicates that stones are no longer susceptible to dissolution and represents, therefore, a definitive treatment failure. Ursodeoxycholic acid (UDCA) has been imputed to facilitate gallstone opacification; however, data regarding the comparative occurrence of gallstone opacification during UDCA and chenodeoxycholic acid (CDCA) administration are not yet available. Our objectives were to evaluate the frequency of acquired opacification in gallstone patients taking UDCA and in gallstone patients taking CDCA, to verify whether or not gallstone opacification is a peculiar side effect of UDCA treatment and, further, to evaluate gallstone opacification in gallstone patients receiving tauro-UDCA (TUDCA) to verify whether the administration of the more soluble tauroconjugate might prevent the deposition of calcium salts on the stone surface. METHODS: 106 gallstone patients on UDCA, 125 gallstone patients on CDCA, and 31 gallstone patients on TUDCA were evaluated. Before treatment, all patients had radiolucent gallstones as assessed by oral cholecystography; further cholecystographic evaluations were performed every 6 months during treatment. RESULTS: The frequency of gallstone opacification was 13.2% (14/106) in UDCA patients, 8.8% (11/125) in the CDCA patients, and 12.9% (4/31) in the TUDCA patients. The differences were not statistically significant (p = NS). Sex, stone size, dose of bile acid, and duration of treatment were not significantly related to an increased frequency of gallstone calcification in any of the treatment groups. The frequency of gallstone opacification appeared to be higher in older patients. CONCLUSIONS: 1) UDCA rich bile is not a major predisposing factor for acquired gallstone opacification; 2) the administration of TUDCA does not prevent gallstone opacification; 3) opacification could be related to the natural history of gallstone disease.
Ursodeoxycholic acid has been proposed for the treatment of primary biliary cirrhosis. The aim of this study was to evaluate the effect of ursodeoxycholic acid administration on bile acid metabolism in patients with early-stage primary biliary cirrhosis. Biliary bile acid composition, primary bile acid pool sizes, synthesis, and fractional turnover rate were measured before and after four weeks of ursodeoxycholic acid administration (600 mg/day) in nine patients with biopsy-proven primary biliary cirrhosis (stages I-III). Molar percentages of chenodeoxycholic, cholic, and deoxycholic acids in bile were significantly decreased by ursodeoxycholic acid administration, while its biliary concentration increased to 34.2% at the end of the same four-week period. The cholic and chenodeoxycholic acid pools decreased, although not significantly, while the deoxycholic acid pool was reduced by 60% (from 0.7 +/- 0.12 to 0.29 +/- 0.07 mmol, P < 0.002). Primary bile acid synthesis was slightly increased, and fractional turnover rate was significantly increased. The conversion rate of cholic to deoxycholic acid was measured and found to be significantly increased (P < 0.05) after ursodeoxycholic acid administration; however, serum levels of both free and conjugated deoxycholic acid were significantly decreased (from 23.2 +/- 9.7 to 3.8 +/- 1.9 mumol/liter, P < 0.001). We conclude that in patients with primary biliary cirrhosis, ursodeoxycholic acid administration replaces endogenous bile acids in the enterohepatic circulation by increasing bile acid fractional turnover rate without significant increments of their hepatic synthesis.
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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 rate of decrease of gallstone diameter appeared to be linear with oral bile acid treatment time, as estimated by inspection of graphic data of individual patient serial oral cholecystograms. A theoretical basis for this model was derived. The hypothesis of diameter decrease proportional to treatment time was tested with data from 223 patients with radiolucent gallbladder stones up to 20 mm in diameter treated with 7-8 or 14-15 mg.kg-1.day-1 of either ursodiol or chenodiol for 1 year, followed up after 3, 6, and 12 months of treatment. Linearity of individual sets of data points was tested by mathematical and statistical methods, including polynomial curve fitting, linear regression analysis, quadratic vs. linear analyses of covariance, and prediction of 12-month stone size by linear extrapolation from diameters at 0 and 6 months. Most patients (greater than 70%) had rates of gallstone diameter decrease that were almost linear with treatment time, independently of different dissolution rates on a given regimen. Additional treatment time needed may be estimated from cholecystograms or ultrasonograms performed before treatment and after several months.
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.
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.
The correlation between biliary and serum levels of ursodeoxycholic and chenodeoxycholic acids was studied in a double-blind controlled manner in 39 patients before and during treatment with ursodeoxycholic acid, 800 mg/day; ursodeoxycholic acid, 400 mg/day; chenodeoxycholic acid, 750 mg/day; chenodeoxycholic acid, 375 mg/day; and placebo, respectively. On a total of 74 occasions, fasting duodenal bile and venous blood samples were obtained simultaneously. Biliary bile acid composition was determined by gas-liquid chromatography and serum ursodeoxycholic and chenodeoxycholic acid concentrations by radioimmunoassays. There was a much closer correlation between the biliary and serum levels of ursodeoxycholic acid (r = 0.8184, P less than 0.001) than between those of chenodeoxycholic acid (r = 0.4707, P less than 0.01). In contrast to serum chenodeoxycholic, which showed many overlaps between pre- and posttreatment values, serum ursodeoxycholic acid proved to be a very sensitive, specific, and convenient means of predicting the presence of increased levels of ursodeoxycholic acid in the enterohepatic cycle.