Low-dose ursodeoxycholic acid prolongs cholesterol nucleation time in gallbladder bile of patients with cholesterol gallstones

The high rate of stone recurrence represents a drawback of non-surgical therapy of cholesterol gallstone disease. Although most studies report that long-term bile acid treatment does not have protective effects, preliminary results suggest that low-dose ursodeoxycholic acid decreases the rate of gallstone recurrence in a subgroup of younger patients. To clarify the underlying mechanism we investigated whether low-dose ursodeoxycholic acid treatment influences biliary cholesterol saturation and/or nucleation time of cholesterol. Ten patients with cholesterol gallstones and functioning gallbladder received 250 mg ursodeoxycholic acid/day at bedtime 6-10 days prior to cholecystectomy. Eleven patients with cholesterol gallstones without treatment served as controls. Cholesterol crystals were present in the gallbladder bile of 7 out of the 10 patients receiving ursodeoxycholic acid and in all control biles. Ursodeoxycholic acid treatment significantly (P less than 0.02) decreased the cholesterol saturation index (mean +/- S.E.: 0.94 +/- 0.05 vs. 1.43 +/- 0.18) and led to an approximately 5-fold prolongation (P less than 0.005) of the cholesterol nucleation time (mean +/- S.E.: 12.0 +/- 2.4 vs. 2.3 +/- 0.7 days). We conclude that low-dose ursodeoxycholic acid might be effective in the prevention of post-dissolution gallstone recurrence by both decreasing cholesterol saturation and prolonging cholesterol nucleation time.     

Possible factors affecting the cholesterol nucleation time in human bile: A filtration study

This study examined the hypothesis that filtration through the MW 300 kD cut-off membrane (XM-300) may influence factors affecting the cholesterol nucleation time (the appearance time of cholesterol monohydrate crystal). Differences in biliary lipids, biliary protein, mucous glycoprotein and vesicular composition were examined before and after the XM-300 filtration in control and cholesterol gallstone patients. The nucleation time in the cholesterol gallstone patients was significantly faster than that in the control patients. However, the nucleation time in the gallstone patients was significantly prolonged following the XM-300 filtration resulting in a similar value to that of the control patients. No differences in concentrations of total protein, mucous glycoprotein or lipids composition were observed. The nucleation time did not correlate with the total lipid concentration, the concentrations of biliary mucous glycoprotein or total protein. The prolonged nucleation time of gallstone bile by the XM-300 filtration was primarily ascribed to the removal of vesicles, which was confirmed by gel chromatography. It was concluded that vesicles greater than MW 300 kD are primarily responsible for the rapid nucleation time.     

Lipid composition and cholesterol nucleation time in gallbladder bile of patients with cholesterol gallstones under choleretic treatment with Febuprol

The effect of a new potent choleretic drug (Febuprol) on lipid composition and cholesterol nucleation time in gallbladder bile was studied in 8 patients with cholesterol gallstones. Nine untreated patients with cholesterol cholecystolithiasis and functioning gallbladder served as controls. Under Febuprol treatment (3 X 100 mg for 6-10 days) mean concentrations of total bile acids (125.4 vs. 59.5 mmol/l), phospholipids (46.1 vs. 25.6 mmol/l) and total lipids (10.4 vs. 5.9 g/dl) were significantly higher (p less than 0.01) than in controls. No significant difference between both groups was calculated for the mean values of cholesterol (17.8 vs. 13.3 mmol/l), cholesterol saturation index (1.5 vs. 2.1) and cholesterol nucleation time (2.1 vs. 2.6 days). Our findings are compatible with a choleretic effect of Febuprol but no alteration of the rapid cholesterol crystallisation in gallbladder bile of patients with cholesterol gallstones was found.     

Cholesterol nucleation time in gallbladder bile of patients with solitary or multiple cholesterol gallstones.

Patients with multiple cholesterol gallbladder stones have been found to be at a higher risk for the recurrence of gallstones after successful nonsurgical treatment than those with a solitary stone. Cholesterol gallstone recurrence, like primary gallstone formation, probably involves a triple defect with supersaturation, abnormally rapid nucleation of cholesterol in bile and altered gallbladder motor function. We investigated whether the increased recurrence rate of patients with multiple stones might be caused by more rapid nucleation. Therefore the time required for cholesterol monohydrate crystals to appear in ultracentrifuged bile of patients with solitary (n = 71) or multiple (n = 42) cholesterol gallstones was determined. The cholesterol nucleation time was significantly (p less than 0.01) longer in the bile from patients with solitary stones (less than 1 to 16 days, median = 2.0 days) than in the bile from patients with multiple stones (less than 1 to 8 days, median = 1.0 days). Moreover, 15 of 71 (21.1%) patients with solitary cholesterol stones but only 1 of 42 (2.4%) patients with multiple cholesterol stones showed a normal (greater than 4 days) nucleation time. However, no difference in the cholesterol saturation index was found between the bile samples from patients with solitary stones and the bile samples from patients with multiple stones (1.55 +/- 0.65 vs. 1.54 +/- 0.59, mean +/- S.D., respectively). The more rapid cholesterol nucleation in gallbladder bile may, therefore, be the major risk factor causing the higher percentage of stone recurrence in patients with multiple cholesterol stones as compared with patients with solitary cholesterol stones.     

Nucleation time and age in patients with gallstones

The relationship between nucleation time (NT), total lipid concentration (TLC) and age was studied in a group of 45 gallstone patients (10 male, 35 female, age 50.1 +/- 14.5 yrs). Bile was obtained by direct fine needle puncture of the gallbladder under local anaesthesia and sonographic monitoring. There was a positive correlation between age and nucleation time (r = 0.626, p less than 0.001), in addition to a negative correlation between age and total bile lipid concentration (TLC) (r = -0.414, p = 0.005). The negative correlation between age and TLC indicates that gallbladder's ability to concentrate the bile decreases significantly with age. It is possible that the decreased concentration is a result of the chronic pathogenetic effects of gallbladder stones. Practically all patients showed a prolonged nucleation time after the 60th year (11.54 +/- 5.50 vs. 2.65 +/- 2.52 days). This would seem to indicate that these patients suffered primarily from bilirubin or calcified stones, currently unsuited for conservative therapy methods.     

Factors affecting the measurement of cholesterol nucleation in human gallbladder and duodenal bile

The study of cholesterol gallstone disease would be facilitated if the nucleation time of cholesterol crystals could be measured in duodenal bile and was correlated with nucleation occurring in vivo. Therefore, our aims were to determine (a) if nucleation time could be measured in duodenal bile, (b) the effect of bacteria, phospholipase, protease, and dilution on the measurement of nucleation time, and (c) the ability of nucleation time of duodenal bile to reflect changes occurring in vivo that promote the formation of gallstones and, therefore, the potential usefulness of nucleation time in predicting and studying the formation of gallstones. Gallbladder bile was obtained from 27 patients undergoing elective cholecystectomy and 19 patients undergoing diagnostic duodenal biliary drainage. Among the 14 bile samples collected by drainage that nucleated within 21 days, mean nucleation time was 6.3 +/- 2.8 days. The addition of inhibitors of phospholipase or protease prolonged nucleation time slightly. Bacteria were cultured from one bile sample at the time of collection and five samples at the time of nucleation. The addition of antibiotics had no effect on nucleation time. Dilution of bile collected at cholecystectomy to the concentration of duodenal bile prolonged nucleation time. In 4 of 5 obese patients receiving a very low calorie diet and predisposed to gallstones, the nucleation time in duodenal bile shortened, and the shortest nucleation times were associated with the formation of cholesterol crystals in vivo. Thus, measurement of nucleation time in duodenal bile may be useful in predicting and studying the formation of cholesterol gallstones.     

The effect of chenodeoxycholic acid (CDCA) on cholesterol absorption.

The effect of administration of chenodeoxycholic acid (CDCA) on cholesterol absorption has been investigated in 11 volunteers. Five hundred milligrams of cholesterol 5 muCi of C14 cholesterol, and 10 muCi of H3 sitosterol (as a nonabsorbable marker) were given with a standard meal. Feces were collected for 6 days and cholesterol absorption was estimated from the recovered C14 radioactivity. The study was repeated after 20 days of treatment with CDCA. Cholesterol saturation of bile and biliary bile acid composition were also studied. Percent CDCA in bile was 40.5 +/- 14.0 SDM before treatment and rose to 75.3 +/- 5.7 after treatment. Saturation index fell from 1.08 +/- 0.31 to 0.71 +/- 0.19. Cholesterol absorption was 33.2 +/- 11.0% of the administered dose in basal conditions and decreased to 14.9 +/- 9.7% after treatment (P less than 0.01). In all but 1 subject, CDCA administration was associated with a decreased intestinal transit time. In conclusion, in doses effective to desaturate bile, CDCA seems to decrease dietary cholesterol absorption. This effect could contribute to the desaturation of bile observed during treatment with this bile acid for dissolving gallstones.     

Nucleation time and lithogenic index in obese patients and in patients with cholecystolithiasis

The gallbladder bile of obese patients without gallstones is supersaturated with cholesterol. The cholesterol saturation index (CSI, LI) of 27 obese patients was 1.32 +/- 0.2. The CSI of 24 normal weight gallstone patients was determined with 1.16 +/- 0.37 and is therefore not significantly different from CSI of obese stone free individuals. The supersaturated bile from obese patients does not accelerated the nucleation of cholesterol crystals. The nucleation time of obese persons was statistically significant longer (16.0 +/- 3.0 days) than in gallstones patients (6.0 +/- 0.78 days) (p less than 0.001). In 50% of the patients with gallstones cholesterol monohydratcrystals were present in the native gallbladder bilde, whereas such crystals are found in only 3.7% of the obese group. Liquid crystals occurred more frequently and in larger number in the bile of the obese patients. The stone forming potency of gallbladder bile can be estimated better by the determination of nucleation time and cholesterol crystals occurrence than by the calculation of the saturation index (CSI).     

Gallbladder emptying in vivo, bile composition, and nucleation of cholesterol crystals in patients with cholesterol gallstones

Impaired postprandial gallbladder emptying may provide time for progressive bile concentration with formation of instable cholesterol-rich vesicles and fast nucleation of cholesterol crystals. The aim of this study was to assess postprandial gallbladder emptying, bile composition, and nucleation of cholesterol crystals in the same patient. In 30 patients with cholesterol gallstones, postprandial gallbladder emptying was measured ultrasonographically. In each patient, gallbladder bile composition (obtained at cholecystectomy) and nucleation of cholesterol crystals was determined. Patients were divided in 22 strong contractors (>50% postprandial gallbladder emptying) and 8 weak contractors. In weak contractors, bile salt and phospholipid concentrations were much higher than in strong contractors ( and , respectively). Cholesterol concentrations were comparable in strong and weak contractors. Consequently, total lipid concentration was significantly higher (15.5 ± 1.4 and 9.2 ± 0.7 g/dL; P < 0.001) and cholesterol saturation index significantly lower (0.90 ± 0.08 and 1.61 ± 0.17; P < 0.001) in weak contractors. Nucleation time, percentage of cholesterol in vesicles, bile salt species, and molecular species of phosphatidylcholine were not significantly different. Differences in bile composition can be linked to different patterns of post-prandial gallbladder emptying and may point to two different pathways of gallstone formation.     

Nucleation of cholesterol monohydrate crystals from hepatic and gall-bladder bile of patients with cholesterol gall stones.

Nucleation time and cholesterol saturation index of hepatic and gall-bladder bile were measured in 16 patients with cholesterol gall stones to determine whether a gall bladder or liver defect was responsible for the rapid nucleation time of gall-bladder bile in such patients. Although hepatic bile was consistently more saturated than gall-bladder bile, the in vitro nucleation time of gall-bladder bile was more rapid. Dilution of gall-bladder bile to hepatic bile concentrations did not affect nucleation time. The results indicate that the gall bladder plays an important role in the production of the rapidly nucleating bile which is found in patients with cholesterol gall stones, and that this role is not simply concentration of bile by the gall bladder. Normal and abnormal gall-bladder biles were also compared in a larger group of patients. The view that there is a nucleation defect in cholesterol cholelithiasis which is independent of cholesterol saturation was confirmed. Subgroups of normal and gall-stone population were defined by the nucleation time and saturation index. Results suggested that solitary stones may be produced under different conditions than multiple stones. Some putative nucleating factors were examined but none was found to distinguish between normal and gall-stone bile.     

Nucleation and growth of cholesterol crystals. Kinetic determinants in supersaturated native bile

Among the factors affecting the stability of supersaturated bile that culminates in the nucleation and growth of cholesterol crystals are biliary lipids. The abundance and composition of these lipids affect the composition of biliary vesicles that, if rich in cholesterol, are themselves unstable and that constitute precursor particles from which cholesterol crystals somehow arise. Kinetic factors can affect stability in either of two ways: They can inhibit cholesterol crystallization, thus stabilizing the system, or they can promote the process of cholesterol crystal nucleation, thus stabilizing the system.     

Rapid cholesterol nucleation time and cholesterol gall stone formation after subtotal or total colectomy in humans.

Changes in biliary lipid composition, pH, ionised calcium, total and unconjugated bilirubin, and cholesterol nucleation time of gall bladder bile samples were examined in six patients who had undergone subtotal or total colectomy between five months and seven years previously, and values were compared with those in control patients with no gall stones. The colectomy group mainly comprised patients with ulcerative colitis and familial adenomatosis coli, in whom only a short length of the terminal ileum (mean (SEM) 2.25 (0.57) cm) had been resected. The reconstruction procedures were ileoanal anastomosis in two patients, terminal ileostomy in two, ileorectal anastomosis in one, and J shaped ileal pouch-anal anastomosis in one patient. The distributions of age, sex, and relative body weight were similar in the two groups. The gall bladder bile was lithogenic in the post colectomy group--these patients had a significantly increased cholesterol saturation index (p < 0.01) and rapid cholesterol nucleation time (p < 0.05) compared with the control group. A significant increase in the molar percentage of cholesterol and a decrease in that of total bile acid associated with significantly decreased secondary bile acids (p < 0.05) were observed in the post colectomy group. Gall stones formed in two of six patients after colectomy were cholesterol stones containing more than 80% cholesterol by dry weight. Total and unconjugated bilirubin, pH, and ionised calcium values were similar in the two groups. The results indicate that after total or subtotal colectomy the composition of gall bladder bile increases the risk of cholesterol gall stone formation.     

Supersaturated bile from obese patients without gallstones supports cholesterol crystal growth but not nucleation

Cholesterol crystal formation was studied in gallbladder bile samples collected from 18 patients with cholesterol gallstones, 6 patients with black pigment stones, and 14 obese patients without gallstones. In the absence of seed crystals, bile from patients with cholesterol stones showed a much greater tendency to form cholesterol crystals in vitro than bile of similar cholesterol saturation from patients without cholesterol stones. The ability to form crystals was not related to the biliary hexosamine concentration, an indicator of mucin content. When small seed crystals of cholesterol monohydrate were added to each bile, the seed crystals dissolved in all biles (n = 8) with a cholesterol saturation index less than 0.76. In contrast, 29 of 30 biles with a cholesterol saturation index greater than 0.76 supported crystal growth, even when collected from patients without gallstones. These results indicate that the difference between supersaturated biles in the ability to form cholesterol crystals resides at the nucleation, rather than the growth, stage of crystal formation.     

Deoxycholic acid in gall bladder bile does not account for the shortened nucleation time in patients with cholesterol gall stones.

The relations between the concentration of deoxycholic acid (DCA), the cholesterol saturation index, and the nucleation time in gall bladder bile were measured to determine the role of DCA in bile in the pathogenesis of cholesterol gall stone disease. Bile was obtained from patients with cholesterol gall stones (n = 30), subjects without gall stones (n = 35), and patients with pigment gall stones (n = 9). Three of 30 cholesterol gall stone patients and 10 of 35 gall stone free subjects were treated with antibiotics by mouth to decrease the concentration of bile DCA and determine the effect of DCA on biliary lithogenecity. Both the percentage and concentration of DCA in bile were similar in patients with and without cholesterol gall stones despite significant differences in their cholesterol saturation indices and nucleation times. Neither the percentage nor the concentration of DCA in bile correlated with either the cholesterol saturation index or the nucleation time. Analysis of subgroups with matching cholesterol saturation indices showed no correlation between the proportion of DCA in the bile and the cholesterol nucleation time. The proportion of DCA in bile was decreased by antibiotic treatment, but this had no effect on the cholesterol saturation index or nucleation time. These results suggest that DCA in bile is not responsible for biliary cholesterol saturation or cholesterol nucleation time.     

UDCA联合异甘草酸镁治疗Ⅱ、Ⅲ期原发性胆汁性肝硬化患者的临床疗效观察

目的探讨熊去氧胆酸(UDCA)联合异甘草酸镁对早中期原发性胆汁性肝硬化(PBC)患者的临床疗效。方法选择我院收治的53例PBC患者,随机分为治疗组(28例)和对照组(25例),治疗组给予UDCA联合异甘草酸镁,对照组单独给予UDCA;比较两组患者临床症状改善和患者免疫指标水平变化情况。结果治疗后治疗组血清TBil、AST、ALT、γ-GGT、ALP均明显低于对照组(P0.05);治疗组治疗4周后总有效率为82.14%,对照组为60.87%,治疗组显著高于对照组,两组相比差异具有统计学意义(χ2=11.102,P=0.000)。治疗后两组患者免疫指标均显著降低,其中治疗组各免疫指标降低水平显著优于对照组,两组间相比差异具有统计学意义(P0.05)。结论 UDCA联合异甘草酸镁治疗Ⅱ、Ⅲ期PBC患者可以显著改善患者的临床症状,提高临床疗效,且不良反应轻微,可以考虑作为PBC的治疗方法之一。     

Correlation between biliaryα 1-acid glycoprotein concentration and cholesterol crystal nucleation time in gallstone disease

A biliary form of theα ₁-acid glycoprotein (AAG) promotes cholesterol crystallization in the lower-molecular-weight, concanavalin A-bound fraction of gallbladder bile. In addition, bile AAG concentration is higher in cholesterol gallstone patients with multiple stones than in control patients without gallstone disease. In this study we sought to determine whether the increased biliary concentration of AAG in cholesterol gallstone patients is accompanied by a more rapid nucleation time in patients with multiple stones. AAG concentration in native biles was measured by ELISA. Nucleation time was measured using a standard microscopy method. The concentration of biliary AAG was then related to nucleation time in biles from the same patients. Nucleation times were significantly shorter (≤5 days) in cholesterol gallstone patients with raised AAG concentrations (P<0.03). There was a significant (P=0.004) negative correlation (r=?0.53) between nucleation time and the AAG concentration in cholesterol gallstone patients with multiple stones. The concentration of biliary AAG appears to exert an important influence on the speed of cholesterol nucleation in bile in many patients with cholesterol gallstone disease.     

Influence of the HMG-CoA-reductase inhibitor lovastatin on cholesterol saturation index and nucleation time of duodenal bile

Owing to the presence of hyperlipoproteinemia IIa, twelve patients without gallstones were treated daily with 20 mg, 40 mg and 80 mg of Lovastatin, each dose being administered for 4 weeks. At the conclusion of each 4-week treatment phase, bile was obtained from the fasting patient following injection of 5 micrograms ceruletid i.v. with the aid of a duodenal tube. The long nucleation time of bile was not shortened by the therapy. The bile cholesterol saturation index showed a decline with Lovastatin, which was particularly obvious in patients with an initially oversaturated bile. In contrast to other lipid-reducing agents (e.g. fibrates), Lovastatin does not lead to increased lithogenesis of the bile, but may in certain circumstances have an prophylactic effect against the formation of gallstones.     

熊去氧胆酸联合多潘立酮治疗原发性胆汁反流性胃炎156例临床研究

目的探讨熊去氧胆酸（UDCA）联合多潘立酮对原发性胆汁反流性胃炎的治疗作用。方法156例原发性胆汁反流性胃炎病人随机分3组。UDCA组予UDCA250mg,1次／d,口服;多潘立酮组给予多潘立酮10mg,3次／d,口服;UDCA联合多潘立酮组给予UDCA250mg,1次／d,口服;联合多潘立酮10mg,3次／d,口服。3组疗程均为8周。采用临床疗效和胃镜随访量化表进行问卷调查,并建立病人的资料档案。结果UDCA联合多潘立酮对原发性胆汁反流性胃炎临床症状总有效率、胃镜征象改变有效率均高于UDCA组和多潘立酮组（P〈0．05）;且H．pylori阳性与H．pylori阴性患者疗效无显著性差异（P〉0．05）。结论UDCA联合多潘立酮能有效缓解胆汁反流性胃炎临床症状;Hpylori对其疗效可能无干扰作用。