Current treatments of primary sclerosing cholangitis

Primary Sclerosing Cholangitis (PSC) is a chronic cholestatic disease characterized by hepatic inflammation and obliterative fibrosis, resulting in both intra- and extra-hepatic bile duct strictures. End-stage liver disease and bile duct carcinoma represent frequent complications. Incidence and prevalence of PSC in USA have been recently estimated as 0.9 per 100,000 person-years, and 1-6 per 100,000 person-years, respectively. Major diagnostic criteria include the presence of multifocal strictures, beadings of bile ducts, and compatible biochemical profile, once excluded secondary causes of cholangitis. Since the aetiology of PSC remains poorly defined, medical therapy is currently limited to symptom improvement and prolonged survival. Ursodeoxycholic acid (UDCA), corticosteroids and immunosuppressants have been proposed alone or in combination to improve the clinical outcome. In selected cases, surgical or endoscopic procedures need to be considered. Orthotopic liver transplantation (OLT) is at the moment the only definitive approach although disease relapse has been reported. In this article the state of the art in PSC treatment and future promises in this field are reviewed.

Differential effects of motilin on interdigestive motility of the human gastric antrum, pylorus, small intestine and gallbladder

Motilin was infused in this study with the aim of examining refractory characteristics for motilin stimulation of antral phase III and fasting gallbladder emptying. Moreover, interdigestive pyloric and small intestinal motility from duodenum to ileum were studied, as these may be target organs for motilin. Eight fasting, healthy male volunteers received, on separate subsequent days, repeated infusions of 13leucine-motilin (8 pmol (kg min)(-1) for 5 min) or saline at 30 min after phase IIIs in the duodenum. Interdigestive motility of the antrum, pylorus, duodenum, jejunum and ileum was measured for maximum 10 h by using a 21-lumen perfused catheter. Gallbladder motility was measured by ultrasonography. Motilin infusions induced antral phase IIIs, but only after a preceding phase III of duodenal origin. Under this condition, time-interval to phase III at the duodenal recording site was 30 +/- 13 (SEM) min after motilin, compared with 79 +/- 14 min after saline (P < 0.01), and compared with 121 +/- 13 min for motilin infusion following an antral phase III (P < 0.001). Motilin did not affect small intestinal motility or isolated pyloric pressure waves (IPPWs). However, the number of IPPWs was significantly affected by the origin of the preceding phase III, irrespective of whether motilin or saline was infused. Gallbladder volume decreased significantly within 10 min after each motilin infusion. We conclude that this study clearly demonstrates differential regional effects of motilin. Motilin initiates antral phase IIIs, but stimulation is subject to a refractory period which is clearly prolonged after a preceding antral phase III. Motilin induced gallbladder emptying, however, is not subject to a refractory state. Small intestinal phase IIIs as well as pyloric IPPWs are not affected by motilin.

Intraduodenal conjugated bile salts exert negative feedback control on gall bladder emptying in the fasting state without affecting cholecystokinin release or antroduodenal motility

BACKGROUND

Intraduodenal bile salts exert negative feedback control on postprandial gall bladder emptying.

AIMS

We wished to examine whether a similar control mechanism occurs in the fasting state.

METHODS

Intraduodenal bile salt depletion was achieved by 12 g of cholestyramine. Thereafter, in study A (seven subjects), the effects on gall bladder volume (by ultrasound) and antroduodenal motility of intraduodenal infusions of taurocholate egg yolk-phosphatidylcholine micelles were assessed. In study B (nine subjects), the effects on gall bladder volume of infusing mixed micelles composed of taurocholate (100 mM) and low (26 mM) or high (68 mM) amounts of egg yolk-phosphatidylcholine, or low amounts of dipalmitoylphosphatidylcholine were determined.

RESULTS

Cholestyramine induced strong and prolonged gall bladder contraction without cholecystokinin release. In study A, micellar infusions increased gall bladder volume without affecting migrating motor complex cycle length. In study B, intraduodenal infusion induced strong increases in gall bladder volume in the case of taurocholate micelles containing low amounts of egg yolk-phosphatidylcholine, moderate increases in micelles containing low amounts of dipalmitoylphosphatidylcholine but no change in micelles containing high amounts of egg yolk-phosphatidylcholine, in all cases without altered plasma cholecystokinin levels. Phosphatidylcholine hydrolysis was significantly higher after infusion of egg yolk-phosphatidylcholine compared with infusion of dipalmitoylphosphatidylcholine containing micelles. Intermixed micellar-vesicular bile salt concentrations (responsible for detergent effects) were higher in egg yolk-phosphatidylcholine than in dipalmitoylphosphatidylcholine containing model biles and if lyso-phosphatidylcholine was included.

CONCLUSIONS

Intraduodenal bile salts exert negative feedback on fasting gall bladder volume. The modulating effects of various phospholipids may relate to their effects on intermixed micellar-vesicular bile salt concentrations.

Acute intraduodenal bile salt depletion leads to strong gallbladder contraction, altered antroduodenal motility and high plasma motilin levels in humans

Cholecystokinin is the main hormone involved in postprandial gallbladder contraction. There is also considerable gallbladder contraction in the fasting state, associated with phase III of the gastrointestinal migrating motor complex and release of the hormone motilin. It has been proposed that intraduodenal bile salts exert a negative-feedback control on postprandial cholecystokinin release and resulting gallbladder contraction. We wanted to elucidate whether a similar control mechanism on gallbladder contraction exists in the fasting state. We therefore performed gallbladder ultrasonography and 24-h antroduodenal motility registrations and determined plasma cholecystokinin and motilin levels in six healthy subjects before and after acute (4 g) and chronic (8 days; 8 g day(-1)) oral cholestyramine. Acute cholestyramine strongly decreased gallbladder volumes and increased motilin without changed cholecystokinin levels. There was a negative relationship between gallbladder volumes and plasma motilin levels. Although there was a persistent fasting pattern of antroduodenal motility, its cycle length was increased (P < 0.03) with markedly longer phase II (P < 0. 005). Fasting gallbladder volumes 24 h later were still strongly decreased but gradually increased to pretreatment levels. Before and after 8 days cholestyramine, interdigestive and postprandial gallbladder emptying, intestinal migrating motor complex and hormone levels did not differ. We conclude that acute (but not chronic) intraduodenal bile salt depletion with cholestyramine affects gallbladder and antroduodenal motility, possibly partly related to motilin release.

Lipid solubilization in human gallbladder versus hepatic biles

BACKGROUND/AIMS

Cholesterol crystallizes more rapidly in gallbladder than in hepatic biles, supposedly due to formation of cholesterol-supersaturated vesicles in concentrated gallbladder biles because of preferential micellization of phospholipids compared to cholesterol. We therefore aimed to compare lipid solubilization in hepatic and gallbladder biles.

METHODS

Mixed micellar and vesicular phases were separated from hepatic and associated gallbladder biles of seven cholesterol gallstone patients by using state-of-the-art gel filtration with bile salts at intermixed micellar/intervesicular compositions and concentrations in the eluant.

RESULTS

Vesicles were found in 6 out of 7 hepatic biles, but only in 2 of the corresponding gallbladder biles. Both percentage (7.8+/-5.1 vs. 36.3+/-7.6%; p = 0.01) and amount (0.9+/-0.2 vs. 1.7+/-0.3 mM; p = 0.06) of vesicular cholesterol were lower in gallbladder biles. Similar results were found for vesicular phospholipids (1.3+/-0.8 vs. 11.6+/-6.0%; p = 0.05; and 0.3+/-0.1 vs. 1.1+/-0.5 mM; p = 0.07). The vesicular cholesterol/ phospholipid ratio was 1.7+/-0.5 in hepatic bile but 4.3 and 1.8 in the 2 gallbladder biles which contained vesicles. Mixed micelles in gallbladder biles had a higher cholesterol saturation index than mixed micelles in hepatic biles (1.43+/-0.11 vs. 1.15+/-0.07; p = 0.02).

CONCLUSIONS

Concentration of bile in the gallbladder leads to decreased vesicular lipid contents. The finding of supersaturated mixed micelles in the absence of vesicles in a significant number of patients points to the possibility of non-vesicular modes of crystallization.

Asymmetric distribution of phosphatidylcholine and sphingomyelin between micellar and vesicular phases. Potential implications for canalicular bile formation

Both phosphatidylcholine (PC) and sphingomyelin (SM) are the major phospholipids in the outer leaflet of the hepatocyte canalicular membrane. Yet, the phospholipids secreted into bile consist principally (>95%) of PC. In order to understand the physical;-chemical basis for preferential biliary PC secretion, we compared interactions with bile salts (taurocholate) and cholesterol of egg yolk (EY)SM (mainly 16:0 acyl chains, similar to trace SM in bile), buttermilk (BM)SM (mainly saturated long (>20 C-atoms) acyl chains, similar to canalicular membrane SM) and egg yolk (EY)PC (mainly unsaturated acyl chains at sn-2 position, similar to bile PC). Main gel to liquid-crystalline transition temperatures were 33. 6 degrees C for BMSM and 36.6 degrees C for EYSM. There were no significant effects of varying phospholipid species on micellar sizes or intermixed-micellar/vesicular bile salt concentrations in taurocholate-phospholipid mixtures (3 g/dL, 37 degrees C, PL/BS + PL = 0.2 or 0.4). Various phases were separated from model systems containing both EYPC and (EY or BM)SM, taurocholate, and variable amounts of cholesterol, by ultracentrifugation with ultrafiltration and dialysis of the supernatant. At increasing cholesterol content, there was preferential distribution of lipids and enrichment with SM containing long saturated acyl chains in the detergent-insoluble pelletable fraction consisting of aggregated vesicles. In contrast, both micelles and small unilamellar vesicles in the supernatant were progressively enriched in PC. Although SM containing vesicles without cholesterol were very sensitive to micellar solubilization upon taurocholate addition, incorporation of the sterol rendered SM-containing vesicles highly resistant against the detergent effects of the bile salt. These findings may have important implications for canalicular bile formation.

Prognostic factors and long-term effects of ursodeoxycholic acid on liver biochemical parameters in patients with primary biliary cirrhosis. Dutch Multi-Centre PBC Study Group

BACKGROUND/AIMS

Serum bilirubin is a prognostic factor in untreated primary biliary cirrhosis (PBC), but this has been less extensively documented for patients treated with UDCA. The aims of this study were to define the effects of UDCA on serum liver tests and to assess prognostic factors in patients on prolonged UDCA treatment.

METHODS

Analysis of laboratory parameters obtained before and during treatment with UDCA of 203 PBC patients who were followed for a mean of 48 months. Univariate and multivariate analyses were performed to assess the prognostic value of pre-entry and follow-up variables with respect to treatment failure and survival.

RESULTS

Actuarial 5-year incidences of treatment failure and transplantion-free survival were 27 and 79%, respectively. According to the univariate analysis the following variables were significantly associated with prognosis: pre-entry presence of cirrhosis and pre-treatment levels of serum bilirubin and albumin, bilirubin levels during follow-up, the occurrence of biochemical remission and normalisation of serum bilirubin. Multivariate analysis revealed that bilirubin during follow-up was the best predictor. Alkaline phosphatase, aspartate aminotransferase and IgM decreased significantly during the first 6 months of treatment and subsequently remained at this lower level. Serum bilirubin showed the same initial pattern, but a significant increase was observed after 4 years of treatment.

CONCLUSIONS

Serum bilirubin in both UDCA-treated and untreated patients is the most powerful predictor of prognosis for PBC. The partial therapeutic efficacy of UDCA is illustrated by the finding that serum bilirubin, in contrast to alkaline phosphatase and the transaminases, appears to increase after 4 years of treatment.

Triple therapy with ursodeoxycholic acid, prednisone and azathioprine in primary biliary cirrhosis: a 1-year randomized, placebo-controlled study

BACKGROUND/AIMS

Treatment with ursodeoxycholic acid has been shown to decrease the rate of disease progression in patients with primary biliary cirrhosis, although the effect is modest. Since primary biliary cirrhosis has many features of an autoimmune disorder, immunosuppressives added to ursodeoxycholic acid may be of value in the treatment of primary biliary cirrhosis.

METHODS

A 1-year randomized, double-blind, placebo-controlled trial was carried out in 50 patients with primary biliary cirrhosis, who had already been treated with ursodeoxycholic acid for at least 1 year, but had not achieved complete disease remission. Patients were randomized to additional prednisone (30 mg per day initially, tapered to 10 mg daily after 8 weeks) and azathioprine (50 mg daily) or placebo. A subgroup of patients received cyclical etidronate and calcium. The principal aim of the study was to assess the short-term benefits and risks of the combined bile acid and low-dose immunosuppressive regimen. Primary endpoints were effects on symptoms, liver biochemistry, liver histology, bone mass and the occurrence of adverse events.

RESULTS

Pruritus (p=0.02), alkaline phosphatase, aspartate aminotransferase, IgM and procollagen-III-propeptide improved significantly (all p<0.002) in the combined treatment group as compared to the placebo group. Histological scores for disease activity and disease stage decreased significantly within the combination treatment group (p<0.001).

CONCLUSIONS

In patients with primary biliary cirrhosis receiving ursodeoxycholic acid, there is an additional beneficial effect of 1-year treatment with prednisone and azathioprine on symptoms and biochemical, fibrogenetic and histological parameters. These results strongly encourage the evaluation of this triple treatment regimen in long-term controlled trials of adequate size to document its effect on clinical events.

After a decade of Helicobacter pylori in The Netherlands. A survey of the practice of the members of the Dutch Society of Gastroenterology

BACKGROUND

Knowledge of Helicobacter pylori infection has grown rapidly during the last decade and management of its associated pathology has changed concordantly.

METHODS

We surveyed the management of H. pylori infection among members of the Dutch Society of Gastroenterology in 1995 via a postal questionnaire.

RESULTS

Almost all 226 respondents (response rate 54%) treated patients for H. pylori infection and the responses suggested that at least 0.1% of Dutch citizens were treated for H. pylori infection in 1995 by this group of specialists. 98% of the respondents treated the H. pylori infection in patients with duodenal ulcer, 91% in cases of gastric ulcer, 56% in cases of gastric lymphoma, 33% in cases of premalignant changes in gastric mucosal histology, 32% in cases of non-ulcer dyspepsia, and 30% in cases of chronic use of proton pump inhibitors. The main diagnostic methods used were histology (93%), urease test (60%), and culture (46%). Triple therapy was most commonly used (54%), followed by quadruple therapy (26%) and double therapy (13%). Follow-up detection of H. pylori was routinely done by 42% of the respondents, while 48% did so only when confirmation of eradication was considered clinically relevant. Most specialists did follow-up detection after 8-12 weeks.

CONCLUSIONS

In 1995 most Dutch specialists treated H. pylori in patients with associated ulcer disease. There was no consensus on its role in other diseases. Diagnostic methods and treatment regimens for eradication differed widely.

Membrane cholesterol content of cholesterol/phospholipid vesicles determines the susceptibility to both damage and protection by bile salts: implications for bile physiology

OBJECTIVES

To investigate the effect of membrane lipid composition on the susceptibility to bile salt damage and protection.

DESIGN

Artificial model cholesterol/phospholipid (c/p) membranes (vesicles) with a varying cholesterol (0-15 mM) and phospholipid content (3-30 mM), and with a c/p ratio ranging up to 1.70, were prepared by sonication. We examined the effect of incubation with increasing concentrations of either tauroursodeoxycholate (TUDC), taurocholate (TC) or taurodeoxycholate (TDC) alone, or with proportionally varying mixtures of TUDC and TDC.

METHOD

Vesicle integrity was assessed by the change in optical absorbance at 340 nm.

RESULTS

Absorption of the bile salt-vesicle mixture decreased, with increasing bile salt concentration and hydrophobicity: TUDC less than TC less than TDC. Moreover, bile salt-induced damage also depended on membrane composition: vesicles containing more than 5 mM cholesterol and with a c/p ratio greater than 0.8 were less likely to be solubilized by 30 mM bile salt. Similarly, only in cholesterol-rich vesicles (c/p > 0.5) was a protective effect of TUDC against membrane disruption by TDC revealed upon incubation with various TUDC/TDC mixtures.

CONCLUSION

Apart from the bile salt concentration and hydrophobicity, the cholesterol content of vesicles is pivotal, both in the bile salt-induced solubilization of cholesterol/phospholipid vesicles and in the potency of TUDC to prevent this.

Apolipoprotein E4 genotype and gallbladder motility influence speed of gallstone clearance and risk of recurrence after extracorporeal shock-wave lithotripsy

Extracorporeal shock-wave lithotripsy (ESWL) is an effective treatment in selected gallstone patients, but stone recurrence is a major drawback. Factors potentially influencing gallstone clearance and recurrence were studied in 84 patients in whom stone dissolution was diagnosed after ESWL plus bile salt therapy for initial solitary (n = 55) or multiple (n = 29) radiolucent stones. Apolipoprotein E (apoE) genotyping and gallbladder motility (sonography) were studied in a representative subgroup of patients (n = 50). The median follow-up after ESWL was 36 months (range, 4.5-67 months). Gallstone clearance was achieved after 8.7 months (range, 0.2-30 months). Independent factors significantly enhancing gallstone clearance were the presence of E4 allele; small initial gallstone size and number; effectiveness of fragmentation; and good gallbladder emptying (P = .002). Gallstone recurrence was seen in 30 patients after 18.6 months (range, 1.0-50 months). Cumulative gallstone recurrence rate (life-table analysis) was 15% within 1 year, increasing to 60% within 5.5 years. Although the probability of gallstone recurrence tended to be smaller in patients with initial solitary stones than in those with multiple stones during early follow-up, differences disappeared after long-term follow-up. Effective gallbladder emptying (residual volume < or = 6 mL) and apolipoprotein E4 (apoE4) independently influenced gallstone recurrence. Recurrence rate was higher (log rank test, P = .037) in those patients who were homozygous and heterozygous for the E4 allele compared with the individuals who were not expressing the apoE4 allele. Accordingly, there was an overrepresentation of the allele frequency for E4 in the group with gallstone recurrence (P =.03). Patients with small postprandial residual gallbladder volumes (</= 6 mL) had a lower probability of stone recurrence than those with large residual gallbladder volumes (log rank test, P = .0215). Biliary pain was more frequent with recurrence (55% vs. 13%, P = .001). The present study indicates that apoE4 genotype is associated with increased speed of gallstone clearance as well as a high risk of recurrence after ESWL. This finding points to a possible role for genetic factors in the pathogenesis of cholesterol gallstones. Effective gallbladder emptying is important for speed of clearance and prevention of recurrence. Patients with initial solitary stones have a decreased early- but not long-term gallstone recurrence rate.

Prospective evaluation of psychosocial adaptation to stoma surgery: the role of self-efficacy

Self-efficacy, one's expectations regarding the ability to perform some specific task, was studied prospectively in the adaptation process of stoma patients. One week after surgery, stoma-related self-efficacy was assessed in 59 patients (26 cancer patients and 33 patients with benign diseases) who had undergone intestinal stoma surgery. Twenty-nine items concerning self-efficacy were formulated. Factor analysis with oblique rotation resulted in two factors: a social functioning-related self-efficacy factor and a stoma care-related self-efficacy factor. Psychosocial adjustment was assessed by means of the Psychosocial Adjustment to Illness Scale (PAIS-SR) at 4 and 12 months after surgery. The PAIS-SR renders one global adjustment score and (in this study) five subscores for adjustment to specific life domains: vocational environment, domestic environment, sexual relationship, social environment, and psychological distress. In a multiple regression analysis, the relevance of self-efficacy for later adjustment was determined after partialing out the effects of relevant sociodemographic and medical factors. Strong evidence was found for the important role of self-efficacy in the process of adapting to a stoma; stronger feelings of self-efficacy shortly after the operation predicted fewer psychosocial problems in the course of the first postoperative year. Stoma care-related self-efficacy appears especially important in the first phase after surgery. Social functioning-related self-efficacy explains significant proportions of the variances in PAIS-SR total score and PAIS-SR subscores, in both the short (4 months after surgery) and long runs (12 months after surgery). If patients expect to be able to take care of their stoma, their postoperative adjustment is relatively good. By strengthening patients' self-efficacy, this adaptation process may be accelerated, and the psychological and social burden can be lightened.

Abnormalities of antroduodenal motility in type I diabetes

OBJECTIVE

In the present study, a recently developed manometric technique was used to study antroduodenal motility in ambulant type I diabetic subjects.

RESEARCH DESIGN AND METHODS

In 12 patients with type I diabetes, antroduodenal manometry was performed for 20 h during the fasting period and the postprandial period after a standardized dinner and breakfast. All patients had evidence of cardiac autonomic neuropathy and complained of dyspeptic symptoms. During the manometric study, the blood glucose levels were frequently monitored and kept close to euglycemia in the diabetic patients. The results were compared with 12 healthy control subjects.

RESULTS

The migrating motor complex cycles observed in the diabetic subjects were longer than in the control subjects, 118.9 +/- 46.0 vs. 87.0 +/- 21.6 min (P < 0.05). This increase was attributable to a prolonged phase II, 78.0 +/- 35.5 vs. 37.7 +/- 18.5 min (P < 0.05). In the diabetic subjects, antral phase III was seen significantly less than in the control subjects, 16.7 vs. 43.3% (P < 0.005). In 50% of the diabetic patients, total absence of antral phase III was observed-this phenomenon was not seen in the healthy control subjects. After dinner, the antral motility index was less in diabetic subjects compared with the healthy volunteers, indicating antral hypomotility (P < 0.01). Six diabetic patients showed abnormal duodenal activity such as early recurrence of phase III and bursts after dinner. No significant differences in antral motility index or in duodenal motility patterns were observed after breakfast. Six diabetic patients complained of dyspeptic symptoms after dinner, whereas none had dyspeptic symptoms after breakfast. In 67% of the patients, nausea was reported after an early phase III or a burst.

CONCLUSIONS

This study shows that prolonged ambulatory antroduodenal manometry is a feasible technique in patients. Recording multiple migrating motor complexes showed that interdigestive motor abnormalities of the stomach and duodenum are common in diabetic patients. Furthermore, it shows the occurrence of antral hypomotility and abnormal duodenal motility patterns after a high-calorie meal, with dyspeptic symptoms in diabetic patients being related to the composition of the meal.

Cholesterol gallstone formation in man and potential treatments of the gallbladder motility defect

Cholelithiasis affects 10-15% of the adult population in Western society, and about 75% of gallstones are of cholesterol type. Hepatic hypersecretion of cholesterol with the formation of instable cholesterol-rich vesicles in bile, an imbalance between nucleation-inhibiting and nucleation-promoting proteins with further aggregation of cholesterol crystals in a gallbladder with a motility defect (stasis), all play a role in the pathogenesis of cholesterol gallstones. Experimental animal models suggest that gallstone formation can be prevented by improving gallbladder emptying. Thus, a better understanding of the causes underlying the impaired gallbladder motor function in patients with gallstones might lead to the selection of therapeutic approaches for those individuals who are at increased risk for the formation or recurrence of gallstones. The present article focuses on current concepts and theories on the pathogenesis of cholesterol gallstones with emphasis on the gallbladder motility defect. Several treatment strategies for the correction of gallbladder hypomotility are also discussed.

The effect of bile acid hydrophobicity on nucleation of several types of cholesterol crystals from model bile vesicles

Nucleation of cholesterol crystals is thought to occur from cholesterol-phospholipid vesicles. We tested the hypothesis that bile acids are necessary for nucleation of cholesterol crystals. Model bile vesicles were prepared by KBr density ultracentrifugation of supersaturated model bile and mixed with one of the following bile acids: ursodeoxycholate, taurocholate, cholate, chenodeoxycholate or deoxycholate in final concentrations of 3, 30 and 100 mM. Vesicles were also mixed with various combinations of ursodeoxycholate and deoxycholate. Nucleation was assessed semi-quantitatively with polarizing microscopy. After 5 days, samples were again subjected to ultracentrifugation. Addition of 3 and 30 mM taurocholate, cholate, chenodeoxycholate and deoxycholate to vesicles induced nucleation. The extent of nucleation increased significantly with increasing bile acid hydrophobicity: deoxycholate > chenodeoxycholate > cholate > taurocholate (p < 0.05). At 100 mM bile acid this order was reversed (p < 0.05) because most of the cholesterol was solubilized in micelles as shown by ultracentrifugation after 5 days. Percentages of vesicular cholesterol decreased with increasing hydrophobicity: deoxycholate < chenodeoxycholate < cholate < taurocholate (p < 0.05). Ursodeoxycholate did not induce nucleation. At least seven cholesterol crystal shapes could be distinguished and all crystal types could be found after addition of various combinations of ursodeoxycholate+deoxycholate. We conclude that in this model: (a) bile acid species play an important role in the precipitation of cholesterol crystals from model bile vesicles; (b) the more hydrophobic bile acids induce more cholesterol crystal precipitation; and (c) the hydrophobicity of bile acids influences cholesterol crystal morphology.

Pioneer in the gluten free diet: Willem-Karel Dicke 1905-1962, over 50 years of gluten free diet

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Therapy with ursodeoxycholic acid in cholestatic liver disease

Ursodeoxycholic acid (UDCA) has beneficial effects on symptoms, liver biochemistry and, possibly, liver histology in primary biliary cirrhosis and other cholestatic liver diseases. UDCA may exert these beneficial effects by a direct hepatoprotective effect, by influencing the enterohepatic circulation of endogenous bile salts, by enhancing bile flow through a cholehepatic shunt mechanism or by immune modulation. In the present article, established and potential indications for UDCA are reviewed.

Pathophysiology and treatment of functional dyspepsia

Functional dyspepsia (or 'non-ulcer') is usually defined as chronic or intermittent upper abdominal symptoms for which no organic cause can be found. Division of functional dyspepsia into subgroups such as reflux-like, ulcer-like, dysmotility-like and non-specific dyspepsia has been proposed, but lacks a scientific basis. Gastric acid hypersecretion, Helicobacter pylori-associated gastritis, gastric and small intestinal motor disorders, psychological and neurohormonal factors all might play a role in the pathogenesis. The heterogeneity of the underlying abnormalities makes it unlikely that one single treatment modality will ever be beneficial to all patients. In general practice, a therapeutic trial, with either a prokinetic or an acid secretion inhibiting drug, is usually carried out before diagnostic procedures are performed to exclude organic abnormalities. In the choice of the initial therapy, some guidance can be derived from the prominent symptoms. In a study in 30 H. pylori-negative patients with functional dyspepsia ranitidine (150 mg bid) significantly reduced the severity of heartburn. The effect was most pronounced in patients of the reflux-like subgroup.

A simple reverse-phase high pressure liquid chromatographic determination of conjugated bile acids in serum and bile using a novel radial compression separation system

A new HPLC method for analyzing conjugated bile acids in bile and especially in serum is presented. For separation of novel radial compression system with a 10-cm flexible-walled reverse phase column (RCM-100 Module, Waters Ass.) packed with micro-Bondapak C18 was used. Without any laborious hydrolysis and derivatization steps, 10 conjugated bile acids are separated easily with a mobile phase of methanol/0.01 mol/1 KH2PO4 (150:50, v/v; pH 6.0) in about 30 min, determined with a variable UV detector at 200 nm and a flow rate of only 0.5 ml/min. Dexamethasone was used as internal standard. Conjugated bile acids are extracted from serum with Sep-pak C18 cartridges after a 1:8 dilution with a mixture of the mobile phase and 0.2 mol/l NaOH (6:8, v/v). Extraction from bile was also performed using Sep-pak cartridges after a 1:20 dilution with 0.5 mol/l phosphate buffer (pH 7.0). The complete analysis time of the method, with Sep-pak extraction, is less than one hour. Recoveries for the different conjugated bile acid varied from 89.4% to 96.7% in serum. The HPLC method for serum and bile was validated for the primary bile acids cholate and chenodeoxycholate against the previously described GLC method. Agreement between the two methods was excellent. Duplicate analyses in serum and bile samples also showed that the reproducibility was good.

Effect of a standardized wheat bran preparation on serum lipids in young healthy males

Feeding of a chemically standardized coarse wheat bran product in a dose of 0.5 g/kg body weight per day over a period of 4 weeks in young healthy male volunteers did cause a significant reduction in total serum cholesterol as well as in total serum triglycerides of 10 and 24%, respectively. Very low density lipoprotein-, high density lipoprotein-, and low density lipoprotein-cholesterol levels tended to diminish during bran feeding. The most marked reduction was observed in the high density lipoprotein- cholesterol fraction. Although the duration of this study was relatively short, it is concluded, that these results could have therapeutic consequences for the dietary management of hyperlipidemia. However, the lowering of high density lipoprotein-cholesterol could also be interpreted as unfavorable since an inverse relationship between high density lipoprotien-cholesterol levels and the occurrence of coronary heart disease has been established.

Diurnal serum levels of primary conjugated bile acids. Assessment by specific radioimmunoassays for conjugates of cholic and chenodeoxycholic acid

The serum levels of conjugates of chenodeoxycholic acid (chenyl conjugates) and of cholic acid (cholyl conjugates) were determined by specific radioimmunoassays during a 24-hour period, which included three liquid meals and an overnight fast, in five healthy volunteers, five patients with previous cholecystectomy, five patients with documented bile acid malabsorption because of ileal resection, and four pregnant women. In healthy subjects, fasting-state levels of chenyl conjugates, when compared with those of cholyl conjugates, were higher; postprandially, levels of chenyl conjugates rose to a peak sooner (30 minutes vs 60 minutes) and to higher levels (5.2 +/- 1.3 muM vs 2.0 +/- 0.5 muM, M +/- SE). In cholecystectomised patients, the integrated areas under the curve for both bile acids were similar to those of the healthy controls, but postprandial peaks were less marked. In patients with bile acid malabsorption, postprandial rises of chenyl conjugates were lower but remained relatively constant throughout the day, whereas cholyl conjugate levels diminished progressively with each successive meal, consistant with depletion of the cholyl, but not the chenyl, pool. In three of four pregnant women, the postprandial rise of chenyl conjugates was disproportionately less compared with that of healthy controls. These results confirm the dynamic complexity of serum bile acid levels in man and indicate that the major circulating primary bile acids are chenyl conjugates. They support previous proposals that jejunal absorption of chenyl conjugates is important in the normal enterohepatic circulation of bile acids; and they suggest an abnormality in the enterohepatic circulation in pregnancy.

Familial and nonfamilial benign recurrent cholestiasis distinguished by plasma disappearance of indocyanine green but not cholylglycine

To determine whether a defect in uptake of organic anions is present in patients with benign recurrent cholestasis, the plasma disappearance of simultaneously injected indocyanine green and cholyglycine-1-14C was measured in eight patients with asymptomatic benign recurrent cholestasis, four with the familial type, as well as 22 healthy control subjects. Evans blue was also simultaneously injected to permit correction for variation in blood volume and speed of mixing. Uptake of indocyanine green was decreased in all three patients with nonfamilial benign recurrent cholestatsis, but normal or increased in the four patients uith the familial form of the disorder. By contrast, cholyglycine-1-14C uptake was abnormal in one patient with each type of the disorder. Thus, patients with nonfamilial benign recurrent cholestasis have a defect in indocyanine green uptake, and patients with benign recurrent cholestasis are heterogeneous with respect to organic anion uptake.

Radioimmunoassay of bile acids: development, validation, and preliminary application of an assay for conjugates of chenodeoxycholic acid

A rapid, sensitive, precise radioimmunoassay for conjugates of chenodeoxycholic (chenic) acid has been developed and validated. Immunogen was prepared with chenylglycine couples to bovine serum albumin, emulsified in Freund's complete adjuvant, and injected intracutaneously in rabbits. Antibodies of moderate titer (used at 1:7500 final dilution) were obtained. Tracer of high specific activity was prepared by reductive tritiation of delta11-chenylglycine. The binding step required 1 hr at room temperature; separation of bound tracer was achieved by addition of ammonium sulfate. The limit of sensitivity of the assay was about 20 nmoles per liter, and the lower limit of the working range was 0.4 mumole per liter. The assay was validated by measuring levels in samples of fasting state serum to which known amounts of chenylglycine had been added; the assay was also validated by means of gas-liquid chromatography on sera from jaundiced patients. The median fasting state serum level in 56 Caucasians and blacks was 0.9 mumole per liter (upper limit of normal (95% confidence) being 2.3), which is in the same range as that reported by others using gas-liquid chromatography. A 5- to 10-fold increase in levels of chenyl conjugates was observed 1 hr after the ingestion of a liquid meal in healthy persons.

A facile hydrolysis-solvolysis procedure for conjugated bile acid sulfates

Methods for hydrolyzing and solvolyzing conjugated bile acid sulfates were compared on reference mixtures of conjugated and unconjugated bile acid sulfates gas-liquid chromatography to assess recovery, and thin-layer chromatography and zonal scanning to define the products occurring after hydrolysis. Conventional methods in which solvolysis preceded vigorous alkaline saponification gave incomplete recoveries. However, essentially complete recovery of primary and secondary bile acid sulfates was obtained with a mild alkaline saponification procedure followed by acidification and extraction into ether, in shich complete solvolysis was shown to occur within 12 hours. Based on these findings, we developed and validated a simple hydrolysis-solvolysis procedure; the method features mild alkaline hydrolysis, acidification to pH 1, and extraction with ether followed by a 1-hour incubation.