Short-term triple therapy with lansoprazole 30 mg or 60 mg, amoxycillin and clarithromycin to eradicate Helicobacter pylori.

BACKGROUND: We investigated the efficacy of 30 vs. 60 mg lansoprazole daily in a 1-week triple therapy for eradication of Helicobacter pylori in a prospective randomized study. METHODS: Two hundred and fifteen consecutive out-patients with peptic ulcer disease or non-ulcer dyspepsia, in whom H. pylori infection was confirmed by histology and/or a urease biopsy test, were randomly assigned to a 1-week treatment with either 15 mg lansoprazole b.d. (LAC15 group) or 30 mg lansoprazole b.d. (LAC30 group) in combination with 1 g amoxycillin b.d. and 500 mg clarithromycin b.d. RESULTS: Eradication of H. pylori was successful in 87% (per protocol) and 82% (intention-to-treat) of the patients with LAC15 and in 94% (per protocol) and 87% (intention-to-treat) of the patients with LAC30. The difference was not significant. In both treatment groups, all peptic ulcers were healed at the check-up. Adverse effects were seen in 11 patients of the LAC15 group and 10 patients of the LAC30 group: they caused discontinuation of the therapy in four of the LAC15 group and two patients of the LAC 30 group. CONCLUSIONS: A 7-day triple therapy using lansoprazole (LAC15) is an efficient and economical regimen for the eradication of H. pylori.

Different protective effects of tauroursodeoxycholate, ursodeoxycholate, and 23-methyl-ursodeoxycholate against taurolithocholate-induced cholestasis.

The coinfusion of tauroursodeoxycholate (TUDC) prevents taurolithocholate (TLC) -induced cholestasis. 23-Methyl-ursodeoxycholate (MUDC) is a side-chain derivative of ursodeoxycholate (UDC). If conjugation with taurine is important for the protective effect of UDC, the MUDC may not be as able as TUDC to prevent TLC-induced cholestasis since it is poorly amidated by the liver. To answer this question, isolated livers of adult Sprague-Dawley rats were coinfused with MUDC (UDC, TUDC) and TLC. After 15 min, inflow rates of the bile acids were doubled. In further experiments taurine in excess was added to the coinfused bile acids. The uptake of bile acids was >90% in all groups, irrespective of whether they were perfused alone or in combination. Single perfusion of TLC caused a rapid decrease in bile flow. UDC and MUDC were hypercholeretic; TUDC moderately choleretic. During coinfusion experiments, TUDC not only completely abolished cholestasis but in addition increased bile flow and biliary bile acid secretion. UDC did prevent TLC cholestasis at the lower inflow rates. At high inflow rates, bile flow decreased significantly. Addition of taurine to this bile acid combination did not significantly improve the anticholestatic effect of UDC. At low and high infusion rates of MUDC, cholestasis induced by TLC was reduced very little. Cumulative bile flow over 30 min fell by approximately 70% as compared to that of singly perfused MUDC. Addition of taurine to the coinfused MUDC/TLC slightly, but less significantly, improved the anticholestatic effect of MUDC. Since MUDC is by far less protective than UDC (and TUDC) despite similar physiochemical properties, it is concluded that taurine conjugation of UDC seems to be a prerequisite to prevent TLC-induced cholestasis. The results imply that treatment of cholestatic liver diseases with taurine-conjugated UDC might be more appropriate than with unconjugated UDC in cases where taurine conjugation is defective or where taurine depletion has occurred.

Change of zonal bile acid processing after partial hepatectomy in the rat.

The aim of this study was to analyze whether partial hepatectomy alters functional liver heterogeneity with respect to bile acid processing. One, 5 and 21 days after liver resection (approximately 80% of liver mass) in male Sprague-Dawley rats (300-400 g), isolated livers were perfused in either the antegrade or the retrograde direction, respectively, with 32 nmol cholate/min per g liver. Uptake, metabolism and biliary secretion kinetics were determined by bolus injection of 14C-cholate. Uptake and biliary recovery (within 30 min) of cholate were > 90% in all groups. One day postresection, liver mass had already doubled and it regenerated to over 80% 5 days after resection. Serum bile acid concentration increased rapidly, peaking 6 h after resection (176.7 +/- 28.5 mumol/l) (mean +/- SEM). Twenty-one days after resection it fell to control values (23.2 +/- 3.8 mumol/l). T25 (T50), the time (min) necessary to excrete 25% (50) of the bile acid load into bile, was strikingly different between periportal and pericentral cells of controls (1.8 vs 5.7 and 3.4 vs 8.1). Five days after resection this difference became smaller (1.4 vs 2.9 and 2.8 vs 5.5) due to accelerated biliary cholate secretion in pericentral cells. Pericentral cells of controls metabolized cholate more extensively to taurocholate (approximately 83%) and glycocholate (approximately 13%) than periportal cells of controls (65%, 10%), leading to a 5-fold higher proportion of unmetabolized cholate in periportal than pericentral cells (25% vs 5%). Five days after resection the percentage of taurocholate decreased significantly at the expense of an increased formation of glycocholate.(ABSTRACT TRUNCATED AT 250 WORDS)

Pattern of bile acid regurgitation and metabolism during perfusion of the bile duct obstructed rat liver.

Bile acid processing in the long-term, bile duct obstructed rat liver was studied ex vivo. Twenty four and 72 h, respectively, after bile duct obstruction the isolated liver was perfused with taurodeoxycholate (16 nmol/min per g liver) the bile duct still being closed. Uptake, metabolism and regurgitation profile were traced by bolus injection of tritium-labeled bile acid; in addition, concurrent histological changes were examined by light- and electron microscopy. Ligation caused dilatation of the intrahepatic ductular branches and increased the serum bile acid concentration to 740 +/- 75 microM (controls: 16 +/- 2.12), reaching its maximum within 24 h. At 16 nmol/min per g liver uptake rate was > 96% in controls and in bile duct obstructed rats. Maximal uptake rates (assessed separately) differed between controls and bile duct obstructed rats (700 nmol/min per g liver vs. 460). Controls excreted more than 80% of labeled bile acid in bile within 10 min after bolus injection. Biliary recovery of label was virtually completed after 30 min. In bile duct obstructed rats excretion of label back to the perfusate effluent (regurgitation) started quantitatively 5 min after bolus application and peaked between 10 and 40 min; after 80 min, effluent recovery was incomplete (about 60% of bolus injected). Biliary bile acids of controls consisted of about 20% taurodeoxycholate-metabolites; bile acids in the perfusate effluent of bile duct obstructed rats of about 55%. The major metabolite in all animal groups was taurocholate; minor metabolites were tauroursocholate, tauro-3 alpha,7 = 0,12 alpha-cholanoic acid and 3-sulfo-taurodeoxycholate. Histologically, inflammation and periportal edema were present after 1 day of bile duct obstruction. After 3 days, marked proliferation of bile ductules was the dominant histological feature. It is concluded that during initial bile duct obstruction, bile acid processing is not altered, although ultrastructural alterations occur early.

Apoptosis during macrophage-dependent ocular tissue remodelling.

We have characterized the nature and pattern of cell death during regression of the pupillary membrane, a developmentally transient capillary network found in the anterior chamber of the eye. This analysis has revealed that the cellular components of the pupillary membrane include vascular endothelial cells in an intricate network of fine capillaries as well as attendant macrophages. The capillaries are situated on the anterior surface of the lens and held in relative position by a cobweb-like meshwork of extracellular matrix fibres that regress along with the cellular components of this structure. Cell death during regression of the pupillary membrane is characteristic of apoptosis. Specifically, apoptotic bodies containing condensed chromatin can be observed in vascular endothelial cells and genomic DNA isolated from the pupillary membrane shows the nucleosomal fragmentation pattern typical of apoptotic cells. Using a method for labelling fragmented DNA in tissue preparations (TUNEL), we have assessed the overall pattern of apoptotic cell death during pupillary membrane regression. We find that apoptosis occurs either in single cells in healthy vessels or synchronously along the entire length of a capillary segment. Both morphological and TUNEL analysis indicate that capillary regression occurs from junction to junction one segment at a time. We propose a model to explain the pattern of capillary regression observed and conclude from these and previous experiments (Lang and Bishop (1993) Cell 74, 453-462), that during regression of the pupillary membrane, the macrophage elicits target cell death by inducing apoptosis.

The transjugular intrahepatic portosystemic stent-shunt procedure for variceal bleeding.

BACKGROUND: Transjugular placement of an intrahepatic stent is a new technique to establish a portosystemic shunt for treatment of portal hypertension. A puncture needle is advanced in a catheter through the inferior vena cava into a hepatic vein; then an intrahepatic branch of the portal vein is punctured and an expandable stent of metallic mesh is implanted to establish the shunt. METHODS: We attempted the stent-shunt procedure in 100 of 112 consecutive patients with variceal bleeding due to cirrhosis, who were then followed for a mean (+/- SD) of 12 +/- 6 months. Of the 100 patients, 22 had Child-Pugh class C cirrhosis, 10 were treated on an emergency basis, and 68 had alcoholic cirrhosis. The shunt was established with use of Palmaz stents expanded to 8 to 12 mm in diameter. RESULTS: Technical success was achieved in 93 percent of the patients. The mean (+/- SD) time for the procedure was 1.2 +/- 0.3 hours. The shunt reduced the portal venous pressure gradient by 57 percent. Major complications were hemorrhage (intraabdominal bleeding in six patients, biliary bleeding in four, and bleeding in the liver capsule in three) and migration of the stent into the pulmonary artery (in two patients). At follow-up, stenosis of the shunt was evident in 21 patients and occlusion in 10 patients; 10 of these 31 patients had variceal rebleeding. Stenoses and occlusions of the shunt were all treated successfully by redilation, thrombolysis, or implantation of an additional stent. Hepatic encephalopathy (stages I to III) developed in 25 percent of the patients. The proportion of patients with shunts who remained free of variceal rebleeding was 92 percent at six months and 82 percent at one year. The 30-day mortality was 3 percent. The cumulative one-year survival was 85 percent. CONCLUSIONS: These results suggest that the transjugular placement of an intrahepatic portosystemic stent is an effective and safe treatment for variceal hemorrhage in patients with portal hypertension due to cirrhosis.

Transjugular intrahepatic portosystemic stent-shunt (TIPS) in the treatment of Budd-Chiari syndrome.

Budd-Chiari syndrome is characterized by splanchnic congestion due to obstruction of the hepatic venous outflow. A variety of treatment modalities have limited applicability due to their invasive nature, complications or low effectivity. The transjugular intrahepatic portosystemic stent-shunt (TIPS) offers a new treatment by creating an intraparenchymal duct between a main branch of the portal vein and hepatic vein i.e. the intrahepatic part of the inferior vena cava. This paper describes the treatment of two patients with fulminant and subacute Budd-Chiari syndrome treated 2 days and 2 months after the onset of clinical symptoms. It demonstrates that TIPS is a feasible treatment of Budd-Chiari syndrome that restores splanchnic blood flow, reduces collateral circulation and ascites and provides sufficient time to allow for elective liver transplantation, if indicated. Further studies are required to evaluate the effect of TIPS on liver function and survival.

[Splenic size and duplex sonography determination of blood flow in the vena lienalis and vena portae in liver cirrhosis]. / Milzgrösse und duplexsonographisch bestimmter Blutfluss in der Vena lienalis und der Vena portae bei Leberzirrhose.

Splenomegaly is a common finding in patients with portal hypertension. In the present study the relation between spleen size and blood flow in the splenic and portal vein was evaluated in 33 patients with alcoholic liver cirrhosis and portal hypertension using pulsed Doppler sonography (Ultramark 9, ATL, Solingen, FRG). There was a significant positive correlation between hilar spleen diameter (HD) and splenic vein diameter (r = .73, p less than .001) as expected as the consequence of portal hypertension. However, a positive correlation between HD and splenic vein flow (SBF) was found (r = .67, p less than .001). Furthermore, there was no negative correlation between HD and flow velocity in the splenic vein (r = .01, n.s.). Portal blood flow (830 +/- 360 ml/min) was fairly constant in spite of considerable variations in SBF (range: 120 to 1200 ml/min). The data of the present study indicate that splenomegaly in patients with liver cirrhosis and portal hypertension is not simply the consequence of portal congestion resulting in decreased SBF. Rather, increased SBF serves to maintain portal blood flow and thereby contributes to portal hypertension. In few patients (15%) SBF increased to more than 11/min may be an important factor for the severity of portal hypertension. Surgical shunt treatment should be adjusted in these patients.

Anion channels in rat liver canalicular plasma membranes reconstituted into planar lipid bilayers.

Previous studies from this laboratory have demonstrated a Cl(-)-HCO3- exchanger and have provided evidence for a Cl- conductance in rat liver canalicular plasma membrane vesicles. To further investigate the apical Cl- conductance, we performed single-channel analysis after incorporation of canalicular liver plasma membrane vesicles into planar lipid bilayers. This was necessary, because the canalicular membrane is not accessible for the patch-clamp technique. Two types of anion channels could be identified (30- and 90-pS conductance) corresponding to the class of small and intermediate channels, respectively. The kinetics of the small channel were found to be voltage dependent with a maximum for the open probability at -20 mV. In contrast, intermediate channel kinetics were voltage independent. The anion channels described above could allow electrogenic Cl- efflux, to compensate Cl- influx via the electroneutral Cl(-)-HCO3- exchanger. Further studies will be required to prove their functional importance in bile formation.

Mechanism of mercurial inhibition of sodium-coupled alanine uptake in liver plasma membrane vesicles from Raja erinacea.

In mammalian hepatocytes the L-alanine carrier contains a sulfhydryl group that is essential for its activity and is inhibited by mercurials. In hepatocytes of the evolutionarily primitive little skate (Raja erinacea), HgCl2 inhibits Na(+)-dependent alanine uptake and Na+/K(+)-ATPase and increase K+ permeability. To distinguish between direct effects of HgCl2 on the Na(+)-alanine cotransporter and indirect effects on membrane permeability, [3H]alanine transport was studied in plasma membrane vesicles. [3H]Alanine uptake was stimulated by an "out-to-in" Na+ but not K+ gradient and was saturable confirming the presence of Na(+)-alanine cotransport in liver plasma membranes from this species. Preincubation of the vesicles with HgCl2 for 5 min reduced initial rates of Na(+)-dependent but not Na(+)-independent alanine uptake in a dose-dependent manner (10-200 microM). In the presence of equal concentrations of NaCl or KCl inside and outside of the vesicles, 75 microM HgCl2 directly inhibited sodium-dependent alanine-[3H]alanine exchange, demonstrating that HgCl2 directly affected the alanine cotransporter. Inhibition of Na(+)-dependent alanine uptake by 30 microM HgCl2 was reversed by dithiothreitol (1 mM). HgCl2 (10-30 microM) also increased initial rates of 22Na uptake (at 5 sec), whereas 22Na uptake rates were decreased at HgCl2 concentrations greater than 50 microM. Higher concentrations of HgCl2 (100-200 microM) produced nonspecific effects on vesicle integrity. These studies indicate that HgCl2 inhibits Na(+)-dependent alanine uptake in skate hepatocytes by three different concentration-dependent mechanisms: direct interaction with the transporters, dissipation of the driving force (Na+ gradient), and loss of membrane integrity. Inactivation of the Na(+)-coupled alanine carrier by mercury in hepatocytes of this evolutionarily primitive vertebrate, as in mammals, suggests that the sulfhydryl groups on this transport protein are highly conserved.

Sulfated bile acids inhibit Na(+)-H+ antiport in human kidney brush-border membrane vesicles.

Patients with obstructive jaundice are at a high risk for acute renal failure after surgery. Direct toxic membrane effects of bile acids or bilirubin have been discussed as possible causes. Therefore, we investigated the influence of bile acids and conjugated bilirubin on Na(+)-H+ antiport and ion permeabilities in brush-border membrane vesicles isolated from the human kidney. Brush-border membrane vesicles were prepared by Mg2+ precipitation. These were highly purified as estimated from the 14-fold enrichment in the specific activity of alanine aminopeptidase. The pH-sensitive dye acridine orange was used to study the properties of proton uptake under different conditions. The brush-border membrane vesicles from human kidney cortex exhibited Na+ and K+ conductances, which were small compared with H+ conductance. Furthermore, these membranes possess an Na(+)-H+ antiporter that is sensitive to amiloride. Various bile acids (30 microM) had no significant effect on Na(+)-H+ antiport. However, the addition of sulfated bile acids resulted in a significant inhibition (greater than 50%) of the Na(+)-H+ antiporter. A nonspecific effect of sulfated bile acids on the vesicles was excluded by the use of ionophores to determine vesicle integrity and to estimate the various ion conductances. Therefore specific inhibition of the human renal Na(+)-H+ antiporter by sulfated bile acids occurs. This could result in an impaired cellular pH regulation and might play a role in postoperative acute renal failure in patients with obstructive jaundice.

Cryptic Na+,K(+)-ATPase activity in rat liver canalicular plasma membranes: evidence for its basolateral origin.

Controversy exists concerning the localization of the enzyme Na+,K(+)-ATPase to canalicular membranes in hepatocytes. Most studies find enzyme activity only at the basolateral plasma membrane domain of the hepatocyte. However, Na+,K(+)-ATPase activity has been detected recently in a canalicular membrane fraction prepared by Mg++ precipitation, suggesting that differences in membrane domain fluidity account for these discrepancies. To reinvestigate this question, we used free-flow electrophoresis to further purify canalicular liver plasma membranes originally separated by sucrose density centrifugation. With this technique, canalicular membranes devoid of Na+,K(+)-ATPase activity by routine assay were separated into six subfractions. More than 80% of the activities of canalicular marker enzymes was recovered in two subfractions closest to the anode, which were totally devoid of Na+,K(+)-ATPase activity. However, Na+,K(+)-ATPase activity could now be detected in the four other fractions that contained only small amounts of canalicular marker enzymes. The basolateral marker enzyme, glucagon-stimulated adenyl cyclase, comigrated with this cryptic Na+,K(+)-ATPase activity. Furthermore, addition of 6 mumol/L [12-(2-methoxyethoxy)-ethyl-8-(cis-2-n-octylcyclopropyl)-octanoate ], a membrane-fluidizing agent, to the original canalicular membrane preparation and to all subfractions did not stimulate or unmask latent Na+,K(+)-ATPase activity. Finally, when canalicular membranes isolated by Mg++ precipitation were subjected to free-flow electrophoresis, they could not be separated from the more positively charged Na+,K(+)-ATPase-containing fractions, probably because of alterations in surface charge. Together these findings suggest that Na+,K(+)-ATPase is a basolateral enzyme, that represents a small contaminant when present in canalicular liver plasma membranes and that methodological differences may account for previous discrepancies.

Evidence for mitochondrial origin of the HCO3(-)-ATPase in brush border membranes of rat proximal tubules.

High HCO3(-)-ATPase activity is known to exist in mitochondria of renal tubular cells. In brush border membrane (BBM) preparations of proximal tubules such an anion-stimulated enzyme was also found. However, these preparations always contained mitochondrial markers. The putative localization and the role of this ATPase in BBM is still controversial. Some authors consider the HCO3(-)-ATPase in the BBM to be a mitochondrial contamination; others attribute to this ATPase a key role in H+ transport in the proximal tubule. To reinvestigate this problem, BBMs from rat kidney cortex were isolated by a simple, rapid (1.5-h) Ca2+-precipitation method, yielding a BBM fraction enriched 12.4-fold with respect to the marker enzyme leucine aminopeptidase (LAP). There was no basolateral Na+-K+-ATPase and no mitochondrial succinate dehydrogenase detectable. Cytochrome c oxidase was drastically reduced to 7 +/- 1% of that observed in the homogenate (TH). The activity of HCO3(-)-ATPase in the BBM fraction was 19 +/- 4 IU/g protein, i.e., 27% that of the homogenate. As sonication of the TH exclusively increases the activity of HCO3(-)-ATPase, its relative activity was 7.5% and thus equal to that of the mitochondrial marker. In many BBM preparations no HCO3(-)-ATPase was detectable. In those BBM preparations in which traces of HCO3(-)-ATPase were found, this activity coincided with that of cytochrome c oxidase in the respective preparation. There was a constant activity ratio of cytochrome c oxidase/HCO3(-)-ATPase in the TH, BBM, and pellet 1. The activity of HCO3(-)-ATPase in BBM did not depend on the activity of LAP.(ABSTRACT TRUNCATED AT 250 WORDS)