Measurement of gallbladder motor functions: an overview.

Control of gallbladder motor functions involve a constant interplay between several stimulatory and inhibitory hormones and neurotransmitters. Gallbladder response to a stimulus is complicated involving rapid alternation of emptying and refilling during the postprandial period. Conventional methodology is not capable of evaluating both emptying and refilling in a quantitative manner, and hence previous studies have yielded a large variation in results in health and conflicting results in gallstone patients. There is therefore, a need for improved methodology. Postprandial refilling and turnover of bile are important parameters that need to be assessed when addressing gallbladder motor function and its role in the pathogenesis of cholesterol gallstone disease.

Ursodeoxycholic acid alone or with chenodeoxycholic acid for dissolution of cholesterol gallstones: a randomized multicentre trial. The British-Italian Gallstone Study group.

BACKGROUND: Combination therapy using ursodeoxycholic acid plus chenodeoxycholic acid has been advocated for dissolution of cholesterol gallstones because the two bile acids have complementary effects on biliary lipid metabolism and cholesterol solubilization. AIM: To compare the clinical efficacy of combination therapy with ursodeoxycholic acid monotherapy. PATIENTS AND METHODS: A total of 154 symptomatic patients with radiolucent stones (< or = 15 mm) in functioning gallbladders were enrolled from six centres in England and Italy. They were randomized to either a combination of chenodeoxycholic acid plus ursodeoxycholic acid (5 mg.day/kg each) or to ursodeoxycholic acid alone (10 mg.day/kg). Dissolution was assessed by 6-monthly oral cholecystography and ultrasonography for up to 24 months. RESULTS: Both regimens reduced the frequency of biliary pain and there was no significant difference between them in terms of side-effects or dropout rate. Complete gallstone dissolution on an intention-to-treat basis was similar at all time intervals. At 24 months this was 28% with ursodeoxycholic acid alone and 30% with combination therapy. The mean dissolution rates at 6 and 12 months were 47% and 59% with ursodeoxycholic acid, and 44% and 59% with combination therapy, respectively. CONCLUSION: There is no substantial difference in the efficacy of combined ursodeoxycholic acid and chenodeoxycholic acid and that of ursodeoxycholic acid alone in terms of gallstone dissolution rate, complete gallstone dissolution, or relief of biliary pain.

Postprandial refilling and turnover: specific gallbladder motor function defects in patients with gallstone recurrence.

BACKGROUND AND AIMS: Impaired gallbladder motor functions are important in the pathogenesis of primary cholesterol gallstones, and possibly in the pathogenesis of recurrent gallstones. By using ultrasonography and cholescintigraphy simultaneously, we recently defined new parameters of gallbladder motor function (postprandial refilling and turnover in addition to emptying), which were markedly impaired in gallstone patients. The aim of this study was to assess the value of these new parameters in distinguishing patients with from those without gallstone recurrence. METHODS: We studied 11 patients with gallstone recurrence, 11 without gallstone recurrence (at least 40 months after complete dissolution by oral bile acids) and 11 healthy controls. Simultaneous measurements of gallbladder volume (ultrasound) and gallbladder counts (gamma-camera scintigraphy) were carried out in the fasting state and at 10 min intervals following meal ingestion, for a period of 90 min. Gallbladder refilling, turnover of bile and turnover index were calculated, as well as gallbladder emptying by both cholescintigraphy and ultrasound. RESULTS: Patients with gallstone recurrence had reductions in gallbladder emptying, postprandial refilling and gallbladder bile turnover. They also had a significant reduction in the turnover index (1.7 +/- 1.4) compared to controls (3.5 +/- 0.3, P < 0.01) and to patients without gallstone recurrence (3.1 +/- 1.5, P < 0.05). Patients without gallstone recurrence had only a small reduction in emptying and no reduction in postprandial refilling or turnover compared to controls. CONCLUSIONS: We conclude that impairment of gallbladder emptying persists in all patients after gallstone dissolution, albeit to a more pronounced extent in patients with recurrence; but that impairment of postprandial refilling and turnover are specific defects in patients with recurrence.

Review article: measurement of gall-bladder motor function in health and disease.

Normal gall-bladder (GB) motor function plays an important role in the enterohepatic circulation of bile acids in health, and abnormal GB motor function has serious clinical implications. The old concept that the GB empties gradually during meals and fills between meals is still believed by many. This paper describes the techniques used in the measurement of GB motor function and discusses the information provided by these techniques in health and disease.

Risk factors for the development of gallstone recurrence following medical dissolution. The British-Italian Gallstone Study Group.

OBJECTIVE: To assess risk factors for gallstone recurrence following non-surgical treatment. DESIGN: A prospective follow-up of a multicentre cohort of post-dissolution gallstone patients. SETTING: Six gastroenterology units in the UK and Italy. PARTICIPANTS: One hundred and sixty-three patients with confirmed gallstone dissolution following non-surgical therapy (bile acids or lithotripsy plus bile acids), followed up by ultrasound scan and clinical assessment at 6-monthly intervals for up to 6 years (median, 25 months; range, 6-70 months). OUTCOME MEASURES: Subject-related variables (sex, age, height, weight, body mass index), gallstone-related variables (number, diameter, presence of symptoms, months to complete stone clearance), treatment modalities (bile acid therapy, extracorporeal shock wave lithotripsy) and follow-up related variables (weight change, use of non-steroidal anti-inflammatory agents, statins, pregnancies and/or use of oestrogens) were assessed by univariate and multivariate analysis as putative risk factors for gallstone recurrence. RESULTS: Forty-five gallstone recurrences were observed during the follow-up period. Multiple primary gallstones and length of time to achieve gallstone dissolution were the only variables associated with a significant increase in the recurrence rate. Appearance of biliary sludge during follow-up was also significantly related to development of gallstone recurrence. Use of statins or non-steroidal anti-inflammatory agents did not confer protection against recurrence. CONCLUSIONS: Patients with primary single stones are the best candidates for non-surgical treatment of gallstones, because of a low risk of gallstone recurrence. The positive association of recurrence with biliary sludge formation and time to dissolution of primary stones may provide indirect confirmation for the role of impaired gallbladder motility in the pathogenesis of this condition.

Demonstration and partial characterisation of phospholipid methyltransferase activity in bile canalicular membrane from hamster liver.

BACKGROUND/AIMS: Methylation of phosphatidylethanolamine to phosphatidylcholine predominantly takes place in mitochondrial-associated membrane and the endoplasmic reticulum of the liver. The transport of the phospholipids from endoplasmic reticulum to the bile canalicular membrane is via vesicular and protein transporters. In the bile canalicular membrane a flippase enzyme helps to transport phosphatidylcholine specifically to the biliary leaflet. The phosphatidylcholine then enters the bile where it accounts for about 95% of the phospholipids. We postulated that the increased proportion of phosphatidylcholine in the bile canalicular membrane and the bile compared to the transport vesicles may be due to a methyltransferase activity in the bile canalicular membrane which, using s-adenosyl methionine as the substrate, converts phosphatidylethanolamine on the cytoplasmic leaflet to phosphatidylcholine, which is transported to the biliary leaflet. The aim of our study was to demonstrate and partially characterise methyltransferase activity in the bile canalicular membrane. METHODS: Organelles were obtained from hamster liver by homogenisation and separation by sucrose gradient ultracentrifugation. These, along with phosphatidylethanolamine, were incubated with radiolabelled s-adenosyl methionine. Phospholipids were separated by thin-layer chromatography and radioactivity was counted by scintigraphy. RESULTS: We demonstrated methyltransferase activity (nmol of SAMe converted/mg of protein/h at 37 degrees C) in the bile canalicular membrane of 0.442 (SEM 0.077, n=8), which is more than twice that found in the microsomes at 0.195 (SEM 0.013, n=8). The Km and pH optimum for the methyltransferase in the bile canalicular membrane and the microsomes were similar (Km 25 and 28 microM, respectively, pH 9.9 for both). The Vmax was different at 0.358 and 0.168 nmol of SAMe converted/mg of protein/h for the bile canalicular membrane and the microsomes, respectively. CONCLUSION: The presence of the methyltransferase activity in the bile canalicular membrane may be amenable to therapeutic manipulation.

Optimum dose of ursodeoxycholic acid in primary biliary cirrhosis.

BACKGROUND: Ursodeoxycholic acid (UDCA) improves liver function tests and prolongs survival in primary biliary cirrhosis (PBC). The dose of 10- 15 mg/kg/day used in the large trials has largely been based on that used for gallstone dissolution. The only dose-response study of UDCA in PBC suggested that a dose of 8 mg/kg/day was the most efficacious. However, disease stage of the patients was not known, higher doses of UDCA were not tried and there was no 'washout period' between the different doses. The aim of this study was to determine the optimum dose of UDCA in early-stage PBC (stage 1 and 2). METHODS: Twenty-four biopsy-proven early-stage PBC patients (one male, 23 female) received five doses of UDCA (0, 300, 600, 900, 1200 mg/day) each for 8 weeks with 4-week washout periods between doses. Symptoms (pruritus, fatigue, diarrhoea) were assessed on a four-point scale (none, mild, moderate, severe). Liver function tests (LFTs) were performed using conventional methods, and serum bile acids were measured using gas liquid chromatography. RESULTS: The dose of 900 mg/day produced the greatest enrichment of UDCA in serum bile acids; although there was no difference in the enrichment of UDCA between the different doses. There was a trend towards normalization of the abnormal LFTs in a dose-dependent manner (for y-glutamyl transferase (yGT), alkaline phosphatase (ALP), alanine transaminase (ALT) and IgM). Multi-factorial analysis showed that UDCA treatment, irrespective of dose, was significantly better than placebo for all the variables. The 900 and 1200 mg doses were better than both 300 and 600 mg using yGT and total bilirubin as variables, better than 300 mg using ALP and IgM as variables, and better than 600 mg using albumin as a variable. No variables showed a significant difference between 900 and 1200 mg. CONCLUSION: The optimum dose of UDCA is 900 mg/day (equivalent to 13.5 mg/kg/day).

Prescribing habits in primary biliary cirrhosis: a national survey.

BACKGROUND: Primary biliary cirrhosis (PBC) is a chronic cholestatic liver disease of unknown aetiology. A number of drugs have been used in its treatment, but only ursodeoxycholic acid (UDCA) has been shown to improve survival. Our aims were to determine the current prescribing habits in PBC of all practising gastroenterologists in the UK. METHODS: A postal questionnaire was sent to 454 gastroenterologists in 1996, followed by a second questionnaire a month later to the non-responders. RESULTS: Of 454 doctors sent questionnaires, 379 (83%) replied. Of these, 58 were excluded from further analysis as they were not practising gastroenterologists. There are an estimated 4337 patients with PBC being seen by gastroenterologists in hospitals. Of these, only 1376 (32%) are being seen in liver units. Ninety-one per cent of gastroenterologists look after patients with PBC (median 10 patients, range 1-500). Ninety-five per cent of gastroenterologists prescribe UDCA but there is a large dose range (median 11.5 mg/kg/day, range 1.5-23.1). Of these, 93% also prescribe cholestyramine. Only 45 (14%) gastroenterologists prescribed other treatments for PBC (13 colchicine, 24 steroids, nine penicillamine, 13 immunosuppressants). Only 53 (17%) treat the symptoms/complications of PBC (37 fat-soluble vitamins, 15 calcium, six bisphosphonates, one hormone replacement therapy, 10 antihistamines, 10 rifampicin). CONCLUSIONS: UDCA is being prescribed for PBC by the majority of practising gastroenterologists but over a wide dose range. Very few gastroenterologists are using preventive treatment for osteoporosis in this high-risk group. Other treatments, as yet unproven in trials, are being prescribed by a minority of gastroenterologists.

Soluble intercellular adhesion molecule-1 in primary biliary cirrhosis: effect of ursodeoxycholic acid and immunosuppressive therapy.

OBJECTIVES: Soluble intercellular adhesion molecule-1 (sICAM-1) is thought to be released by a variety of cells at sites of inflammation, and their serum levels have been used as markers of inflammatory and immune activity. Our aim was to determine the effect of therapy with ursodeoxycholic acid alone and in combination with azathioprine and prednisone on serum sICAM-1 levels in primary biliary cirrhosis. DESIGN/METHODS: Twenty-four patients with primary biliary cirrhosis and 17 healthy subjects were studied. Primary biliary cirrhosis patients received ursodeoxycholic acid for 12 months and were then randomized in a double-blind fashion to receive prednisone and azathioprine, or placebo in addition to ursodeoxycholic acid. RESULTS: sICAM-1 levels were significantly higher in primary biliary cirrhosis patients than healthy subjects and fell by a median of 20% after 12 months' therapy with ursodeoxycholic acid (P<0.0004). Addition of azathioprine and prednisone to ursodeoxycholic acid resulted in a further reduction of sICAM-1 levels by a median of 25% (P< 0.01). Reductions in sICAM-1 were accompanied by improvement in liver function tests but not in the lymphocyte activation marker, soluble interleukin-2 receptor. CONCLUSION: sICAM-1 levels in primary biliary cirrhosis are reduced by ursodeoxycholic acid. Further reductions were achieved by adding prednisone and azathioprine. These reductions probably reflect an improvement in hepatobiliary excretion and a reduction in cellular production of sICAM-1.

Serum intercellular adhesion molecule-1 in alcoholic liver disease and its relationship with histological disease severity.

BACKGROUND: Infiltration of the liver by leukocytes is a histological feature of alcoholic liver disease. Intercellular adhesion molecule-1 (ICAM-1) mediates the migration of lymphocytes from the circulation to target sites of inflammation. It has been demonstrated in the liver of alcoholic liver disease subjects and as a circulating soluble form (sICAM-1). The origin of sICAM-1 and its relationship to disease severity is unknown, although it has been postulated that it may arise from activated T lymphocytes and is an inflammatory marker. AIMS: The aim of the study was to determine the relationship of sICAM-1 to clinical and histological severity of alcoholic liver disease and to serum T-cell (soluble interleukin-2 receptor (sIL-2R), beta 2-microglobulin) and monocyte (neopterin) immune activation markers. METHODS: Serum from 48 outpatients with biopsy proven alcoholic liver disease (steatosis = 9, cirrhosis = 28, hepatitis +/- cirrhosis = 11), 31 with primary biliary cirrhosis and 27 normals was assayed for sICAM-1, sIL-2R, beta 2-microglobulin, and neopterin. RESULTS: sICAM-1 was significantly elevated, p = 0.0001, in alcoholic liver disease and primary biliary cirrhosis patients compared to normals. Circulating sIL-2R (p = 0.0001) and beta 2-microgloblin (p = 0.0034) were significantly elevated in alcoholic liver disease compared to controls. There was a highly significant correlation between levels of sICAM-1 and histological grade of disease, Rs = 0.80 (p = 0.0001), but no significant correlation with clinical correlates of disease severity or circulating immune activation markers. CONCLUSIONS: sICAM-1 is elevated in alcoholic liver disease, is a marker of histological severity of disease and does not appear to originate from activated T lymphocytes. Measurements of sICAM-1 may be useful in assessing histological severity of alcoholic liver disease.

Repeated bile acid therapy for the long-term management of cholesterol gallstones.

BACKGROUND/AIMS: Following non-surgical treatment, cholesterol gallstones recur in a high proportion of patients, and recurrence cannot be predicted nor effectively prevented. Our aim was to test prospectively the viability and the efficacy of repeated bile acid therapy, in which recurrent stones are diagnosed at an early stage by regular ultrasound monitoring and promptly retreated, as a strategy for the management of these patients in clinical practice. METHODS: One hundred and seventy-two consecutive patients were recruited upon achieving complete gallstone dissolution using non-surgical therapy (bile acids or lithotripsy plus bile acids), and followed up at 6-monthly intervals by ultrasound scan. Gallstone recurrence was promptly treated by a combination of ursodeoxycholic acid plus chenodeoxycholic acid (5 mg/kg per day each) for a period of 2 years, or less if complete redissolution was achieved. Median follow-up period was 34 months (range 6-70). RESULTS: Forty-five patients had gallstone recurrence; of these, 39 underwent one or more repeated courses of bile acid therapy (follow-up data available in 27). Gallstone recurrence rate was 15% at 1 year and 47% at 5 years. Average annual redissolution rate of recurrent gallstones (intention to treat) was 41%. The proportion of gallstone-free patients in the whole population was 88%, 84%, 77%, 78%, 75% at 1-5 years, respectively, and rose to > 90% at 3 years onwards in patients with single primary stones. CONCLUSIONS: We conclude that repeated bile acid therapy maintains the majority of patients gallstone free, and is therefore an effective long-term management strategy, especially in patients with primary single gallstones.

Determination of gallbladder bile lithogenicity in patients with primary biliary cirrhosis.

Patients with primary biliary cirrhosis have a higher prevalence of gallstone disease. Aim of this study was to determine whether gallbladder bile of these patients is lithogenic. We studied 11 patients with early stage primary biliary cirrhosis, and compared them with 16 control subjects. We combined a cholescintigraphic method with nasoduodenal bile sampling to measure the mass of lipids within the gallbladder. Cholesterol saturation index, as measured by standard techniques, was similar in patients with primary biliary cirrhosis and controls (medians: 0.85 vs 0.90). Primary biliary cirrhosis patients showed a significant reduction in the masses of cholesterol, phospholipids and bile acids, as well as in percent biliary deoxycholic acid, as measured by high pressure liquid chromatography (medians 8.6% vs 17.4% in controls; p < 0.05). Percent deoxycholic acid directly correlated with cholesterol mass in all subjects (r = 0.48; p < 0.05). Biliary lipid coupling were similar in the two groups. We conclude that, in patients with early stage primary biliary cirrhosis, gallbladder bile is not lithogenic and biliary lipid coupling is normal, due to a parallel reduction in the masses of cholesterol, phospholipids and bile acids. The significant reduction in percent deoxycholic acid, characteristic of cholestasis, may help explain this biliary lipid mass pattern, that differs from that of cholesterol gallstone patients.

Intrahepatic biliary cholesterol and phospholipid transport in humans: effect of obesity and cholesterol cholelithiasis.

The mode of transport of biliary lipids within the hepatocyte and the role of the bile canalicular membrane (BCM) in biliary lipid secretion are not well understood. We hypothesized that biliary cholesterol and phospholipid are co-transported across the hepatocyte in vesicular form from the endoplasmic reticulum to the bile across the BCM. We obtained wedge liver biopsies and fasting gallbladder bile from 15 cholesterol gallstone patients and 10 control subjects. BCM, basolateral membrane (BLM), and many microsomal vesicular fractions were isolated by centrifugation. One of the vesicular fractions (V3) was enriched in both the microsomal and the BCM marker enzymes and had a high phosphatidylcholine proportion in its phospholipid with a fatty acid pattern similar to biliary phosphatidylcholine. Moreover, its cholesterol content was increased in the obese cholesterol gallstone subjects, who had an increase in cholesterol synthesis, as indicated by the increased activity of the HMG-CoA reductase. The cholesterol content correlated with HMG-CoA reductase activity. A direct correlation was found between cholesterol/phospholipid ratio in V3, BCM, and in bile but not in the BLM. These data are in agreement with the assumption that this vesicular fraction is involved in the transport of cholesterol and phospholipid from the endoplasmic reticulum to the site of secretion in the BCM, and thence to bile, and that this transport is enhanced in obese gallstone patients.

Direct assessment of the mechanism for a raised serum bile acid level in chronic liver disease.

BACKGROUND: Impaired hepatic uptake is the major cause of raised serum bile acid levels in liver disease, but confirmation in humans by direct measurement is lacking. The synthetic gamma-labelled bile acid 75Se-homocholic acid taurine (75SeHCAT) provides a tool for the direct measurement of hepatic bile acid handling. OBJECTIVE: To determine the interrelationships among hepatic handling of 75SeHCAT, the kinetics of its disappearance from plasma and serum bile acid levels in patients with chronic liver disease. DESIGN: We studied 12 patients with primary biliary cirrhosis and 14 with cirrhosis arising from other causes. Fasting serum bile acid levels were measured enzymatically. After intravenous administration of 75SeHCAT, we determined plasma disappearance rates (initial K1, late K2) from serial blood samples and hepatic uptake and excretory rates directly from dynamic abdominal gamma-camera scanning. Both scanning and sampling were carried out over a period of 90 min. RESULTS: Serum bile acid concentrations correlated with K1 and with hepatic uptake (Rs = -0.53, P < 0.01; Rs = -0.47, P < 0.02, respectively) but neither with K2 nor with the excretory rate. K1 and uptake were reduced (P < 0.05) in patients with high serum bile acid levels and in those with varices. Serum bile acid levels were higher in patients with varices (P < 0.05), which might suggest that portosystemic shunting occurred. However, this is unlikely because the varices were not independent of liver function. CONCLUSION: Hepatic bile acid uptake and excretion are independent processes. Hepatic uptake is related to initial, whereas hepatic excretion is related to late, plasma disappearance. Impaired hepatic uptake is a major determinant of the rise in serum bile acid levels in chronic liver disease.

Prospective, multicenter study on value of computerized tomography (CT) in gallstone disease in predicting response to bile acid therapy.

The aim of the study was to assess the value of quantitative attenuation values (Hounsfield units) and of gallstone pattern by computerized tomography in predicting response to bile acid therapy. We carried out a prospective study in a multicenter setting on 90 consecutive outpatients with radiolucent gallstones. All received bile acid therapy (UDCA 10 mg/kg/day or UDCA + CDCA 5 mg/kg/day of each) up to two years. Hounsfield units for gallstones were recorded using standardized criteria and six categories of patterns were defined: hypodense, isodense, homogenously dense, laminated, rimmed and speckled. We assessed gallstone dissolution rate (percent reduction in volume), response to therapy (> 25% reduction in volume), and final outcome of therapy. Eighty-one percent of patients with hypodense/isodense and all four patients with speckled stone pattern responded to therapy, whereas none of the 10 patients with laminated/rimmed and only 45% of patients with homogenously dense stone pattern did. Complete dissolution was achieved by 68%, 50%, 35%, 0% of the hypodense/isodense, speckled, homogenously dense, rimmed/laminated gallstones, respectively. The use of Hounsfield units did not show an advantage over gallstone pattern for predicting either response or final outcome to bile acid therapy. We conclude that computerized tomography analysis of gallstones is of value in predicting response to bile acid therapy and that gallstone pattern alone predicts response in most cases without the need for quantitative assessment.

Postprandial gallbladder motor function: refilling and turnover of bile in health and in cholelithiasis.

BACKGROUND & AIMS: Impaired gallbladder emptying is implicated in gallstone disease. Ultrasonography and scintigraphy have shown conflicting results because the former is influenced by postprandial refilling, whereas the latter is not influenced by refilling. The aim of this study was to measure postprandial refilling and turnover of bile by combining the two techniques. METHODS: Simultaneous scintigraphy and ultrasonography were used in 14 patients with gallstones and 11 healthy controls. Measurements were performed while the patients were fasting and at 10-minute intervals after a standard meal for 90 minutes, and the measurements were used to calculate postprandial refilling, turnover of bile (in milliliters), and turnover index. RESULTS: Ultrasonography and scintigraphy provided different gallbladder emptying patterns. Compared with controls, patients with gallstones had impaired emptying by both scintigraphy (P < 0.0001) and ultrasonography (P < 0.01). Postprandial refilling and turnover were both reduced between 60 and 90 minutes (P < 0.05), and the turnover index was markedly reduced (1.8 vs. 3.5; P < 0.001). CONCLUSIONS: Simultaneous scintigraphy and ultrasonography provide a new model of gallbladder motor function showing that refilling begins immediately postprandially. In healthy controls, the gallbladder postprandially handles up to six times its basal volume within a period of 90 minutes, but this turnover of bile is markedly reduced in cholelithiasis causing a reduced washout effect of the gallbladder contents, including cholesterol crystals.