The Italian journal of gastroenterology最新文献

To evaluate the effect of bile acid structure on total protein secretion and composition, 4 different bile acids, deoxycholic acid, chenodeoxycholic acid, cholic acid and ursodeoxycholic acid, in order of decreasing hydrophobicity, were infused intraduodenally in 5 cholecystectomized T-tube patients with interrupted enterohepatic circulation. Concentration and composition of biliary proteins were evaluated before and after acute substitution of the endogenous bile acid pool with each bile acid. Total biliary protein concentration and secretion increased progressively with increasing hydrophobicity of the infused bile acid and was highest for deoxycholic acid, followed by chenodeoxycholic acid, cholic acid and ursodeoxycholic acid. A significant increase in the 120 and 150 kDa protein bands on gel-electrophoresis was found after infusion with the more hydrophobic bile acids (deoxycholic acid and chenodeoxycholic acid). Quantitative and qualitative changes in biliary proteins, associated with the administration of bile acids that have different physico-chemical structures, may be relevant to the process of cholesterol crystal nucleation and the pathogenesis of gallstone formation.

A review is made of the literature regarding the present status of ursodeoxycholic acid in the treatment of primary biliary cirrhosis, focusing on the difficulties encountered in establishing the efficacy of this and any other therapy in the management of the disease. It is concluded that further studies or, at least, an updated meta-analysis including the final data emerging from the multicentre, long-term, randomised, double-blind, controlled trials currently under way are needed to establish the clinical importance of ursodeoxycholic acid as a therapeutic agent in primary biliary cirrhosis.

Aim of the investigation is to precisely study the morphological features of ventral pancreas ductography in pancreas divisum, in order to improve the radiological interpretation and differential diagnosis of this frequent pancreatic anomaly. The clinical part of the study was based on 610 endoscopic retrograde pancreatograms, with pancreas divisum diagnosed in 14 (2.3%) cases; while the anatomical part consisted of 203 postmortem pancreatograms of human pancreas obtained at autopsy, where pancreas divisum was found in 12 (5.9%) cases. The following ductal features of the ventral pancreas were studied: length and calibre of the main duct, number of side branches, calibre of the common bile duct and the biliopancreatic junction angle. No significant differences were detected between the results from the 2 groups, with the exception of side branches, which were more numerous in the anatomical series, probably because of higher injection pressure and consequent better opacification. These results underline the potential of the anatomical pancreatography serving as a model for studying the ductal system of pancreas divisum.

Measurement of anti-gliadin antibodies is considered a highly sensitive test for coeliac disease in children. Specificity, however, appears to vary due to the presence of anti-gliadin antibodies in other diseases. Sensitivity and specificity of anti-gliadin antibody measurement for coeliac disease in adults has, thus, been assessed using the ratio of the densitometric unit test/the mean +3SD of densitometric unit values of a pool of sera of healthy biopsy-proven controls. Anti-gliadin antibodies-A and G were measured separately with an enzyme-linked immunosorbent assay in 64 coeliacs (20 males; 44 females; age range 14-71 years) with diagnosis confirmed at jejunal biopsy; and in 60 controls (25 males; 35 females; age range 16-69 years) with normal jejunal biopsy. Detection of anti-gliadin antibodies-A and G had a sensitivity of 58% and 61%, respectively, and a specificity of 85% and 94%. For the procedure a Receiver Operating Characteristic analysis was used. Considering anti-gliadin antibodies-A and G values of at least 0.9 densitometric unit, sensitivity was 50% and 60%, respectively, whereas specificity was 100% for both. These findings confirm the low sensitivity of these measurements in adult coeliacs and thus the unreliability for screening. The high specificity, when using a threshold value of 0.9 densitometric unit, may be useful in the evaluation of adults with suspected coeliac disease.

Impaired postprandial gallbladder emptying may be an important factor in cholesterol crystals precipitation and subsequent gallstone formation. We previously found strongly increased bile salt concentrations in gallbladder bile of gallstone patients with weak (< 50% fasting volume) postprandial gallbladder contraction compared to patients with strong (> 50%) postprandial contraction. Therefore, we studied potential effects of various conjugated and unconjugated bile salts with different relative hydrophobicity on in vitro contractility of gallbladder muscle strips obtained at cholecystectomy. Strips were incubated 5 min with bile salt at concentrations of 10(-8)-10(-4)M. The effect of 10(-3)M acetylcholine was measured and related to preincubation control value. Bile salts used were, in order of increasing hydrophobicity: tauroursodeoxy-, ursodeoxy-, tauro-, taurodeoxy- and deoxycholate. Ursodeoxy- and tauroursodeoxycholate did not significantly reduce gallbladder contractility. Taurocholate significantly reduced contractility at concentrations of 10(-6) M and higher, taurodeoxycholate at 10(-7) M and higher and deoxycholate at 10(-5) M and higher. Contractility induced by acetylcholine 10(-3) M at a bile salt concentration of 10(-4) M was 66.0 +/- 11.7% (taurocholate), 50.2 +/- 6.2% (deoxycholate) and 44.8 +/- 11.5% (taurodeoxycholate) of control. The effect of bile salts correlated with their relative hydrophobicity (r = -0.97; p < 0.01). Suppressing effects on gallbladder muscle strip contractility were long lasting and remained after rinsing. Results show that bile salts in the physiological dose range inhibit in vitro gallbladder contraction. If this mechanism exists in vivo, it may have important implications for gallbladder motility regulation.

Fasting and postprandial gallbladder volumes have been measured by sonography both in healthy subjects and gallstone patients ingesting: (a) tauroursodeoxycholic acid; (b) ursodeoxycholic acid; (c) placebo. Each bile salt was given at a dose of 10 mg kg-1. Sonography was repeated in gallstone patients fed tauroursodeoxycholic acid or ursodeoxycholic acid (10 mg kg-1 day-1) for 1 month. Gallstone patients had gallbladder stasis (increase in fasting and residual volumes) and decreased postprandial emptying. Acute ingestion of tauroursodeoxycholic acid or ursodeoxycholic acid did not modify postprandial gallbladder emptying in both groups of subjects. After one month's therapy with tauroursodeoxycholic acid or ursodeoxycholic acid, fasting gallbladder volume further increased in gallstone patients, although gallbladder emptying remained unchanged. Thus, therapeutic doses of tauroursodeoxycholic acid or ursodeoxycholic acid do not acutely modify postprandial gallbladder emptying in either healthy subjects or gallstone patients. Chronic treatment with either bile salts results in an increase in fasting gallbladder volume without interfering with the extent of postprandial gallbladder emptying.

Liver affects the release and clearance of many hormones, but the interactions between gastrointestinal peptides and liver function are obscure. Aim of this study was to evaluate plasma concentrations of gastrointestinal peptides during acute hepatic cytonecrosis and during liver regeneration in man. The study was performed in ten patients with viral hepatitis (8 virus A, 2 virus B) in the acute phase (alanine transaminase = 3073 +/- 739 U/L; mean +/- SEM), and at days 7, 45 and 52 after the initial evaluation, during clinical and biochemical recovery (52nd day, alanine transaminase = 77 +/- 26). Plasma concentrations of the following hormones were evaluated by radioimmunoassay: glucagon, insulin, gastrin, vasoactive intestinal peptide, bombesin, neurotensin, cholecystokinin, secretin and motilin. Only serum bombesin and cholecystokinin were significantly (p < 0.01) increased in the acute phase of hepatitis (bombesin: 138 +/- 21 pg/ml; cholecystokinin: 57 +/- 7 pg/ml); they returned to normal values during convalescence (bombesin: 60 +/- 8; cholecystokinin: 31 +/- 4). During hepatocellular necrosis, plasma concentrations of cholecystokinin and bombesin, which are both cellular growth factors and regulatory signals of food introduction and satiety state, were increased by 83% and 130%, respectively. Increase of these hormones may cause the dyspepsia and lack of appetite that characterizes the initial phase of acute viral hepatitis.

Magnetic resonance cholangiopancreatography is a new, non-invasive imaging technique for visualization of the biliary ducts. Magnetic resonance cholangiopancreatography was performed on 136 patients (20-87 years old) with a superconductive magnet at 0.5T (Philips Gyroscan T5). Volumetric images on coronal planes were acquired; a T2 weighted turbo spin echo sequence (TR = 3000; TE = 700; number of excitations = 8; echo train length = 128; Acquisition time = 5'48") with respiratory compensation was performed. Images were reconstructed on coronal planes rotated at different angles using the MIP algorithm. When neoplastic disease was detected additional images on axial planes (SE Tlw: TR/TE 300/10 and turbo spin echo T2w: TR/TE 3000/120) were acquired. Magnetic resonance cholangiopancreatography allowed images of diagnostic value to be obtained in all cases. In choledocholithiasis, the technique had a sensitivity of 91.6%, specificity of 100% and overall diagnostic accuracy of 96.8%. Of the 48 patients with stenotic lesions, 16 cases were correctly characterized as benign and 30 as malignant. Two cases of focal chronic pancreatitis were misdiagnosed as pancreatic head carcinoma. In patients submitted to bilioenteric anastomosis, the technique was able to detect dilation of intrahepatic ducts, stenosis and associated stones in the 8 positive cases. In all 11 patients with chronic pancreatitis, dilated Wirsung duct and the stenotic tracts were revealed. In conclusion, magnetic resonance cholangiopancreatography can be considered as a technique able to completely replace diagnostic endoscopic retrograde cholangiopancreatography. However, further studies are necessary for a better evaluation of potential advantage and disadvantages.

Diagnostic paracentesis is usually considered the first test to be performed in the assessment of the ascitic patient and a large number of investigations on ascitic fluid have been proposed. To assess the value of a simplified procedure, serum to ascites albumin gradient and ascitic white blood cell counts were employed as a first step. One hundred and fifty-three paired serum and ascitic fluid samples were analysed and allowed patients to be divided into three groups: 1) serum to ascites albumin gradient > = 11 g/L and white blood cells < 0.5 x 10(9)/L predicted cirrhosis (or liver carcinoma) without peritonitis with 83% efficacy, 96% positive predictive value and 65% negative predictive value; 2) serum to ascites albumin gradient > = 11 g/L and white blood cells > = 0.5 x 10(9)/L predicted cirrhosis (or liver carcinoma) with peritonitis with 86% efficacy, 45% positive predictive value and 99% negative predictive value; 3) serum to ascites albumin gradient < 11 g/L predicted the other diagnoses with 92% efficacy, 77% positive predictive value and 95% negative predictive value. As serum to ascites albumin gradient > = 11 g/L and white blood cells < 0.5 x 10(9)/L predicted cirrhosis (or liver carcinoma) without peritonitis in 96% of the cases and excluded peritonitis in 99% of the cases, further fluid ascitic analyses could be considered as a second step only in patients with serum to ascites albumin gradient < 11 g/L and/or white blood cells > = 0.5 x 10(9)/L. In a group of ascitic patients where the prevailing diagnosis is cirrhosis (or liver carcinoma) without peritonitis, this simplified approach could provide a favourable cost/benefit ratio.