Group B streptococcal beta-hemolysin induces nitric oxide production in murine macrophages

Group B streptococcus (GBS) is the leading cause of sepsis in neonates. Nitric oxide (NO) release plays a role in the hypotension that characterizes septic shock. To examine the role of the GBS beta-hemolysin in NO production, the murine macrophage line RAW 264. 7 was exposed to a wild-type (WT) GBS isolate and to hyperhemolytic (HH) and nonhemolytic (NH) transposon mutants derived from that isolate. After activation of macrophages by the WT strain, the HH mutant, or cell-free extracts of beta-hemolysin, nitrite release into the supernatant increased >10-fold and inducible NO synthase (iNOS) levels in cell lysates increased up to 10-fold compared with treatment with the NH mutant or extracts from that mutant. Hemolysin-induced NO production was dependent on protein tyrosine kinases and NF-kappaB, but not on extracellular signal-related kinase-1/2-mitogen-activated kinases or protein kinase A. These results indicate that GBS beta-hemolysin induces murine macrophage iNOS via intracellular pathways similar to those that mediate lipopolysaccharide-induced iNOS activation.

Downregulation of ileal bile acid absorption in bile-duct-ligated rats

BACKGROUND/AIMS

Accumulation of toxic bile acids in cholestasis contributes to liver injury and depends on their synthesis, secretion and intestinal absorption. In the present study, we investigated the effect of cholestasis on the active ileal absorption of bile acids in vivo and the adaptation of transporters involved in ileal bile acid absorption.

METHODS

Male Wistar rats underwent ligation of the common bile duct or biliary diversion. Sham-operated rats served as controls. Active ileal bile acid absorption of taurocholate was measured by an intestinal perfusion technique. Transporter mRNA levels of the Na+/bile acid cotransporting protein (IBAT), ileal lipid binding protein (ILBP) and organic anion transporter subtype 3 (Oatp3) and protein expression of IBAT and ILBP were determined in the distal ileum.

RESULTS

After bile duct ligation the intestinal absorption rates of taurocholate were lower (p<0.05) and after biliary diversion absorption rates were higher compared to sham-operated animals (p<0.05). The absorption rates were inversely correlated to serum bile acid concentrations. Levels of IBAT-, ILBP- and Oatp3- mRNA were not different between the groups. However, in cholestatic rats, the expression of the 99-kDa dimer of IBAT was decreased compared to controls (p<0.05), whereas the 46-kDa monomeric protein of IBAT and the expression of ILBP was unchanged. After biliary diversion a similar pattern of protein expression was observed, despite an increased absorption rate.

CONCLUSIONS

Cholestasis leads to a decreased active ileal absorption of taurocholate. The changes in protein expression may not account for the different absorption rates. The intestinal absorption of bile acids seems to be regulated by their systemic concentration.

Helicobacter pylori vacA genotypes and cagA gene in a series of 383 H. pylori-positive patients

BACKGROUND

Only 10-15% of all patients infected with Helicobacter pylori develop peptic ulcer disease (PUD) or gastric cancer. Apart from immunological factors in the host, virulence determinants of H. pylori such as the vacuolating cytotoxin (VacA) or the cytotoxin-associated protein A (CagA) might represent a predisposition for the development of PUD.

METHODS

We studied antral biopsies of 383 H. pylori-positive patients with peptic ulcer disease (PUD) or other H. pylori-related diseases for H. pylori vacA genotypes and the presence of the cagA gene by PCR.

RESULTS

VacA genotypes and cagA status could be completely determined in 357 (93.2%) of the patients. In 91 (93.8%) of 97 patients with PUD, the vacA s1 genotype (s1m1, 45; s1m2, 46 patients) was present. The vacA s2m2 genotype was found in only 6 (6.2%) of 97 patients with PUD. In contrast, 180 (75.3%) of 239 patients (s1m1, 89; s1m2, 91 patients) without PUD and without gastric malignancies harbored strains with the vacA s1 genotype. The vacA genotype s2m2 was found in 59 (24.7%) of these patients. The presence of the cagA gene was closely associated with the vacA genotype s1 and found in 124 (88.6%) and in 113 (80.7%) of patients with the s1m1 or s1m2 genotypes, respectively, whereas strains with the genotype s2m2 were almost exclusively cagA negative.

CONCLUSION

Most H. pylori strains found in patients with PUD possess the vacA s1 genotype and the cagA gene. Patients with this type of H. pylori strain but without PUD might be at higher risk of developing PUD. In contrast, the risk for PUD might be significantly decreased in those patients who are infected by H. pylori strains with the vacA s2 genotype lacking the cagA gene.

Sodium, hydrogen exchange type 1 and bile ductular secretory activity in the guinea pig

Biliary epithelial cells (BECs) express different Na(+), H(+) exchange (NHE) isoforms. In this study, the potential role of NHE in ductular bile secretion is assessed. Experiments were performed in guinea pig perfused livers and isolated BECs. Inhibition of NHE was achieved by hypotonic stress and by using the unspecific NHE inhibitor, amiloride, or the specific NHE 1 inhibitor, cariporide (HOE 642). Hypotonic stress inhibited basal bile flow by 46% and prevented secretin stimulation of bile flow by reducing biliary bicarbonate output by 50%. Secretin increased bile flow from 3.7 +/- 0.8 microL/min/g to 4.78 microL/min/g (P <.01); subsequent exposure to hypotonic stress decreased secretin-stimulated bile flow by 35% and biliary bicarbonate secretion by approximately 50%. Inhibition of NHE by amiloride or cariporide resulted in a similar reduction of secretin-stimulated bile flow and bicarbonate secretion. Basal bile flow was unaffected by the NHE inhibitors. In isolated guinea pig BECs, regulatory volume decrease and inhibition of NHE was demonstrated after hypotonic stress under basal and secretin-stimulated conditions. In contrast, hypotonic exposure inhibited Cl(-), HCO(3)(-) exchange activity in isolated BECs only during basal conditions but incompletely after secretin stimulation. Our study shows that hypotonic stress inhibits basal bile flow in the guinea pig by inhibition of Cl(-), HCO(3)(-) exchange. NHE1 is not involved in basal bile formation. Increased choleresis after ductular stimulation by secretin depends on intact NHE1 activity. These data indicate that BEC volume changes have profound effects on biliary secretory function.

Effect of tauroursodeoxycholic acid on bile acid-induced apoptosis in primary human hepatocytes

BACKGROUND/AIMS

The accumulation of endogenous bile acids contributes to hepatocellular damage during cholestatic liver disease. To evaluate the potential role of apoptotic cell death due to increased concentrations of bile acids, primary human hepatocytes were treated with hydrophobic and hydrophilic bile acids. Because the Fas receptor-ligand system may mediate apoptosis in human liver cells, the effect of toxic bile acids on hepatocellular Fas receptor expression was evaluated.

MATERIALS AND METHODS

Primary human hepatocytes were incubated with 50 and 100 microM glycochenodeoxycholic acid (GCDCA) and co-incubated with equimolar concentrations of tauroursodeoxycholic acid (TUDCA). To evaluate cytolytic and apoptotic effects, morphological alterations, hepatocellular enzyme release, nuclear DNA fragmentation and hepatocellular Fas receptor expression were evaluated.

RESULTS

Apoptotic cell death was significantly increased after exposure to 50 microM GCDCA. Bile acid-induced apoptosis was not accompanied by hepatocellular Fas receptor overexpression. Tauroursodeoxycholic acid reduced apoptosis, as indicated by a significant reduction of oligonucleosomal DNA cleavage. Fas receptor expression was not significantly affected by tauroursodeoxycholic acid. At higher concentrations, direct cytolytic cell destruction was observed.

CONCLUSION

Primary human hepatocytes represent a suitable model to study bile acid-induced apoptotic cell death. In these hepatocytes, already low bile acid concentrations might induce apoptotic cell death, which is not triggered by hepatocellular Fas receptor overexpression. Apoptotic DNA fragmentation was significantly reduced by co-incubation with tauroursodeoxycholic acid. The reduction of bile acid-induced apoptosis by ursodeoxycholic acid and its conjugates may contribute to the beneficial effects of these hydrophilic bile acids used for medical treatment of several cholestatic liver diseases.

Functional interactions between oxidative stress, membrane Na(+) permeability, and cell volume in rat hepatoma cells

BACKGROUND & AIMS

Oxidative stress leads to a rapid initial loss of liver cell volume, but the adaptive mechanisms that serve to restore volume have not been defined. This study aimed to evaluate the functional interactions between oxidative stress, cell volume recovery, and membrane ion permeability.

METHODS

In HTC rat hepatoma cells, oxidative stress was produced by exposure to H(2)O(2) or D-alanine plus D-amino acid oxidase (40 U/mL).

RESULTS

Oxidative stress resulted in a rapid decrease in relative cell volume to 0.85 +/- 0.06. This was followed by an approximately 100-fold increase in membrane cation permeability and partial volume recovery to 0.97 +/- 0.05 of original values. The volume-sensitive conductance was permeable to Na(+) approximately K(+) >> Tris(+), and whole-cell current density at -80 mV increased from -1.2 pA/pF at 10(-5) mol/L H(2)O(2) to -95.1 pA/pF at 10(-2) mol/L H(2)O(2). The effects of H(2)O(2) were completely inhibited by dialysis of the cell interior with reduced glutathione, and were markedly enhanced by inhibition of glutathione synthase.

CONCLUSIONS

These findings support the presence of dynamic functional interactions between cell volume, oxidative stress, and membrane Na(+) permeability. Stress-induced Na(+) influx may represent a beneficial adaptive response that partially restores cell volume over short periods, but sustained cation influx could contribute to the increase in intracellular [Na(+)] and [Ca(2+)] associated with cell injury and necrosis.

Seropositivity for MIA and S100 in patients with gastrointestinal carcinomas

Serum levels of melanoma inhibiting activity (MIA) and S100, both markers in malignant melanoma, are increased only in few patients with non-melanocytic tumors. We examined a series of serum samples from patients with colorectal (CRC) (N=56), gastric (GC) (N=43), pancreatic (PC) (N=29), hepatocellular (HCC) (N=30), cholangiocellular and gallbladder carcinoma (CCC) (N=18). MIA and S100 were measured by commercially available assays. Positive serum levels for MIA and S100 were found in 16.1% and 5.4% of the patients with CRC, 11.6% and 9.3% with GC, 34.5% and 13.8% with PC, 0% and 30% with HCC and 16.7% with CCC, respectively. All patients with sera positive for either MIA or S100 suffered from advanced tumors and received palliative treatment. Elevated serum levels of MIA and S100 are frequent in patients with gastrointestinal cancer. Further investigation is warranted to define the role of MIA or S100 seropositivity in gastrointestinal cancer with regard to follow-up.

Interaction of endothelial cells and neutrophils in vitro: kinetics of thrombomodulin, intercellular adhesion molecule-1 (ICAM-1), E-selectin, and vascular cell adhesion molecule-1 (VCAM-1): implications for the relevance as serological disease activity markers in vasculitides

Recently markers of endothelial cell activation or injury gained increasing interest as serological parameters of disease activation in vasculitides. Among these, soluble serum thrombomodulin, ICAM-1, VCAM-1 and E-selectin are of particular interest. However, only thrombomodulin showed the expected close correlation. The objective of this study was to investigate in vitro the kinetics of these endothelial cell receptors after interaction of unstimulated or cytokine-activated polymorphonuclear neutrophils (PMN) and endothelial cells in order to find evidence explaining these different clinical findings. Over the time period of up to 48 h of incubation the kinetics of thrombomodulin, ICAM-1, E-selectin, and VCAM-1 levels in the supernatant of endothelial cells in co-culture with neutrophils were determined in vitro by ELISA under basal and partially cytokine-activated (tumour necrosis factor-alpha) conditions. Increased levels of ICAM-1, E-selectin and VCAM-1 were already found due to cytokine activation of endothelial cells alone. This increase was augmented after coincubation with neutrophils. In contrast, a significant increase of thrombomodulin in the supernatant was only found due to cell injury after cell-cell interaction of cytokine-activated endothelial cells with neutrophils. In conclusion, this in vitro model of the kinetics of soluble endothelial cell receptors after cell-cell interaction of cytokine-activated PMN and endothelial cells underlines the advantage of thrombomodulin in contrast to the adhesion molecules as a marker of endothelial damage. Therefore, soluble thrombomodulin seems to be a promising, valuable serological disease activity marker in vasculitides.

Serum thrombomodulin-a reliable marker of disease activity in systemic lupus erythematosus (SLE): advantage over established serological parameters to indicate disease activity

To date no specific serological parameter is available to assess disease activity in SLE. Soluble serum thrombomodulin is a new marker of endothelial cell injury and vasculitis. The objective of this study was to compare in vivo soluble thrombomodulin as marker of disease activity in SLE with established and recent serological parameters. One hundred and twenty-four sera of 30 patients with proven SLE with different disease activities were tested for serum levels of thrombomodulin, intercellular adhesion molecule-1 (ICAM-1), E-selectin, vascular cell adhesion molecule-1 (VCAM-1), IL-2R, IL-6, IL-10, dsDNA by ELISA and dsDNA additionally by radioimmunoassay (RIA). C-reactive protein (CRP), complement component C3, IgG, creatinine, anti-nuclear antibodies (ANA) and intermediate filament antibodies were measured by standard laboratory tests. The clinical disease activity was evaluated by the Systemic Lupus Activity Measure (SLAM). Correlations of the different serological SLE disease activity parameters with the SLAM scores revealed the highest significance for serum thrombomodulin (correlation coefficient 0.82). This was further confirmed by the intra-individual analysis of follow-up sera. In addition, a moderate correlation could be found for IL-6, IL-10, ICAM-1, CRP and erythrocyte sedimentation rate (ESR). In summary, soluble thrombomodulin is the most important serological parameter of disease activity in SLE currently available, as shown by the in vivo studies. Soluble thrombomodulin might be a valuable serological parameter for therapeutical considerations.

HFE downregulates iron uptake from transferrin and induces iron-regulatory protein activity in stably transfected cells

Hereditary hemochromatosis (HH) is a common autosomal-recessive disorder of iron metabolism. More than 80% of HH patients are homozygous for a point mutation in a major histocompatibility complex (MHC) class I type protein (HFE), which results in a lack of HFE expression on the cell surface. A previously identified interaction of HFE and the transferrin receptor suggests a possible regulatory role of HFE in cellular iron absorption. Using an HeLa cell line stably transfected with HFE under the control of a tetracycline-sensitive promoter, we investigated the effect of HFE expression on cellular iron uptake. We demonstrate that the overproduction of HFE results in decreased iron uptake from diferric transferrin. Moreover, HFE expression activates the key regulators of intracellular iron homeostasis, the iron-regulatory proteins (IRPs), implying that HFE can affect the intracellular "labile iron pool." The increase in IRP activity is accompanied by the downregulation of the iron-storage protein, ferritin, and an upregulation of transferrin receptor levels. These findings are discussed in the context of the pathophysiology of HH and a possible role of iron-responsive element (IRE)-containing mRNAs.

[Long-term collagenous sprue--remission with a gluten-free diet]

We report on a 56-year-old caucasian female, 154 cm, 38 kg, who was admitted to the hospital in extremely poor, cachectic condition with pretibial edemas, ascites and pleural effusion with a history of severe watery diarrhea up to 15 times daily. The patient's history with permanent meteorism, recurrent episodes of watery diarrhea and dystrophy dates back to her early childhood. Multiple biopsies from the distal part of the duodenum showed a complete atrophy of villi with an extensive subepithelial layer of collagenous fibers. No antigliadin or antiendomysial antibodies could be detected. Under a strictly gluten-free diet, the patient's symptoms quickly improved. During the follow-up of one year, no recurrence of diarrhea and meteorism has been seen. The patient showed a continuous improvement of her general condition and nutritional state with a weight gain to 50 kg. Repeated control biopsies still revealed a pronounced villous atrophy. However, no subepithelial collagenous fibers were detectable. A diagnosis fitting to the patient's clinical symptoms of severe malabsorption, would be the rare "collagenous sprue", which is considered to be gluten-insensitive. However, the patient's good response to a gluten-free diet raises the possibility, that the collagenous layer represents a manifestation of more severe forms of common celiac disease. In this case, it would not be necessary to regard collagenous sprue as a distinct entity.

Localization of the Wilson's disease protein in human liver

BACKGROUND & AIMS

Wilson's disease is an autosomal-recessive disorder of copper metabolism that results from the absence or dysfunction of a copper-transporting P-type adenosine triphosphatase that leads to impaired biliary copper excretion and disturbed holoceruloplasmin synthesis. To gain further insight into the role of the Wilson's disease protein in hepatic copper handling, its localization in human liver was investigated.

METHODS

By use of a specific antibody, localization of the Wilson's disease protein was studied in liver membrane fractions and liver sections by immunoblotting, immunohistochemistry, and double-label confocal scanning laser microscopy.

RESULTS

The 165-kilodalton protein, found by immunoblotting, was most abundant mainly in isolated plasma membrane fractions enriched in canalicular domains. Immunohistochemistry revealed intracellular punctuate staining of hepatocytes in certain regions of the liver, whereas a canalicular membrane staining pattern was observed in other regions. Double-labeling studies showed that in the latter regions the transporter is present mainly in vesicular structures just underneath the canalicular membrane that are positive for markers of the trans-Golgi network. A weak staining of the canalicular membrane, identified by staining for P-glycoprotein, was observed.

CONCLUSIONS

These results show that in human liver the Wilson's disease protein is predominantly present in trans-Golgi vesicles in the pericanalicular area, whereas relatively small amounts of the protein appear to localize to the canalicular membrane, consistent with a dual function of the protein in holoceruloplasmin synthesis and biliary copper excretion.

Cell specific effects of glucocorticoid treatment on the NF-kappaBp65/IkappaBalpha system in patients with Crohn's disease

BACKGROUND/AIMS/PATIENTS: Glucocorticoid treatment is known to reduce nuclear factor-kappa B (NF-kappaB)p65 binding activity and activation in lamina propria cells of patients with Crohn's disease. However, lamina propria cells of glucocorticoid treated patients did not show increased expression of IkappaBalpha, and the hypothesised upregulation of IkappaBalpha by glucocorticoid treatment has not yet been shown in vivo. To investigate whether cells other than lamina propria localised mononuclear cells contribute to increased IkappaBalpha, resection gut specimens from patients matched for Crohn's disease activity index (CDAI) with or without glucocorticoid treatment were studied, and changes in the NF-kappaB/IkappaBalpha system were determined in the lamina propria as well as in underlying submucosal and endothelial cells.

METHODS

Changes in the NF-kappaB/IkappaBalpha system were determined by immunohistochemistry, electrophoretic mobility shift assay, and western blot analysis in resected gut specimens from patients matched for CDAI and van Hees index with or without long term glucocorticoid treatment.

RESULTS

Resection gut specimens from patients with Crohn's disease under glucocorticoid treatment had significantly lower nuclear NF-kappaBp65 levels in mononuclear, epithelial, and endothelial cells than samples from CDAI and van Hees index matched patients not having glucocorticoid treatment. Nuclear NF-kappaBp65 showed a strong positive correlation with both the CDAI (r = 1 for both groups) and the van Hees index (r = 0.605 for untreated and r = 0.866 for glucocorticoid treated specimens). Lower nuclear translocation of NF-kappaBp65 in the glucocorticoid treated group was paralleled by higher IkappaBalpha levels in vascular endothelial cells, but not in infiltrating mononuclear cells.

CONCLUSION

A comparison of resection gut specimens from untreated and treated CDAI matched patients with Crohn's disease showed downregulation of NF-kappaB binding activity and NF-kappaBp65 expression and cell specific induction of endothelial IkappaBkappa expression in the glucocorticoid treated group. As the two groups showed similar disease activity (CDAI, van Hees index), the activation of the NF-kappaBp65/IkappaBalpha system must be only part of the inflammatory cascade leading to the clinical appearance of Crohn's disease.

[Flu-like infection and liver disease after a stay in the tropics]

HISTORY AND ADMISSION FINDINGS

A 38-year-old patient, an experienced traveller to the tropics, fell ill with a flu-like infection, a fever of up to 38.6 degrees C and nausea on returning from an 8-week trip to southern Africa (Namibia, Zambia and Zimbabwe). Physical examination was unremarkable, except for slight physical debility. His father had died of liver cirrhosis of unknown aetiology, aged 68 years.

INVESTIGATIONS

Laboratory tests revealed eosinophilia (12% on a count of 7,800 WBC/microliter, increased transaminase activities [SGPT 142 U/l, SGOT 50 U/l, gamma GT 32 U/l], slightly increased serum ferritin [1057 ng/dl], but normal serum iron and transferrin levels). Untreated stool contained Schistosoma mansoni eggs. Tests for a haemochromatosis gene and its type showed a homozygotic C282Y variant. Liver biopsy demonstrated chronic portal hepatitis with parenchymal transformation and marked haemosiderin deposits in liver epithelium.

DIAGNOSIS, TREATMENT AND COURSE

The schistosomiasis was treated with praziquantel, 40 mg/kg by mouth on one day, divided in three doses, without complication. The haemochromatosis was treated symptomatically, at first by weekly bloodletting 500 ml while monitoring serum ferritin concentration. Life-long bloodletting at longish intervals is anticipated.

CONCLUSIONS

The incidence of some infectious diseases has greatly risen as a result of an increase in tourism to distant lands. In particular, the diagnosis of frequent parasitic diseases should become part of the expertise in internal medicine. The combination of several diseases should be considered in the differential diagnosis.

[Megaloblastic anemia in a psychogenic eating disorder]

HISTORY AND ADMISSION FINDINGS

A 68-year-old woman had progressively lost strength over the past 5 years and become bed-ridden. She reported gradually reducing her diet during the last few years, for the last two years restricting herself to oatmeal, biscuits and water. Acute exacerbation of dyspnoea, dizziness, tachycardia and cardiac arrhythmias for the last 3 month necessitated her emergency admission when she was found to have oedema of the limbs and definite jaundice, as well as predominantly distal sensory deficits in the legs, a slightly ataxic gait and poor reflexes in the limbs.

INVESTIGATIONS

She was found to have pancytopenia with marked megaloblastic anaemia (haemoglobin 4.8 mg/dl, mean red cell volume 141.8 fl, leukocytopenia 41/nl), marked haemolysis (lactate dehydrogenase 1629 U/l, haptohaemoglobin < 0.1 g/l, total bilirubin concentration 4.5 mg/dl). Pernicious anaemia was excluded: no antibodies against parietal cells and intrinsic factor, and no atrophic gastritis in a gastric biopsy.

DIAGNOSIS, TREATMENT AND COURSE

Megaloblastic anaemia due to dietary deficiencies with early funicular myelosis was suspected. After infusion of four erythrocyte concentrates and vitamin B12 administration the symptoms and blood picture improved within days.

CONCLUSION

Although dietary causes of megaloblastic anaemia are rare in Central Europe, they must be considered in the differential diagnosis, especially in the elderly and those with psychogenic disorders.

Therapy of pseudomyxoma peritonei of appendiceal origin--surgical resection and intraperitoneal chemotherapy

Pseudomyxoma peritonei (PMP) is rare clinical entity presenting with mucus-producing lesions on the peritoneal surface. PMP is found in middle-aged or older patients in approximately two out of 10,000 laparotomies. Most of the reported cases are due to a primary process located in either appendix or the ovaries. PMP presents with an insidious onset of symptoms, and is characterized by long-term survival with good general health and absence of visceral invasion or distant metastasis. The treatment of choice for PMP is surgical resection and the removal of free mucus. Despite a high rate of disease recurrence, adjuvant or palliative chemotherapy has not yet been clearly established. In our opinion, intraperitoneal application may be more effective than a systemic regimen because only local treatment can provide sufficient concentrations of chemotherapeutic agents. In view of the lack of standardized treatment regimens and based on our experience, we recommend intraperitoneal chemotherapy with 5-FU and mitomycin C or cisplatin. We report ten cases of PMP of appendiceal origin and present a review of the literature on this disease and its treatment.

Direct determination of Helicobacter pylori vacA genotypes and cagA gene in gastric biopsies and relationship to gastrointestinal diseases

OBJECTIVE

Our aim was to detect Helicobacter pylori (H. pylori) from gastric biopsies of 248 patients using a novel, polymerase chain reaction (PCR)-based methodology, which simultaneously facilitates the determination of H. pylori vacA genotypes and cagA gene.

METHODS

A simple methodology for sample preparation was established and PCR was performed with primer systems for the 16S rRNA, vacA, and cagA genes, thus circumventing the need to culture H. pylori and to extract DNA from biopsy samples.

RESULTS

Infection with H. pylori was detected in 147 (59.3%) of 248 patients. The vacA signal sequence genotype s1 was present in 104 (81.3%) of 128 H. pylori-positive patients, and 24 (18.8%) patients had the genotype s2. The vacA middle region types m1 and m2 were detected in 46 (35.9%) and 79 (61.7%) patients, respectively. The combinations s1/m2 (43%) and s1/m1 (35.9%) were found more frequently than s2/m2 (18.8%). The cagA gene was detected in 75 (72.1%) of 104 H. pylori-positive biopsies with the vacA genotype s1. All 24 biopsies with the type s2 were cagA negative. Strains of the type vacA s1 were found in 97% of H. pylori-positive patients with peptic ulcer disease and were associated with the presence of the cagA gene, whereas 96% of the strains of the type vacA s2 were detected in patients who only had nonulcer dyspepsia.

CONCLUSIONS

Using a novel PCR-based methodology, H. pylori 16S rRNA gene, vacA genotypes, and cagA gene can now be rapidly detected directly in gastric biopsies with high accuracy. These data demonstrate that infection with H. pylori strains of the vacA s1 genotype and the cagA gene are more likely to result in peptic ulcer disease. Determination of vacA genotypes and cagA gene may contribute to the potential clinical identification of patients at different levels of risk.

Expression of a bile acid transporter in biliary epithelial cells from normal and cholestatic rat livers

A sodium dependent bile acid carrier has recently been cloned and characterized in rat ileum. The present study demonstrates the presence of a mRNA species specific for the rat ileal bile acid carrier (r-IBAT) in rat biliary epithelial cells. Moreover, immunohistochemistry with a peptide specific antibody demonstrates protein expression in biliary epithelial cells from normal and bile duct ligated rat livers. Besides a cytoplasmic staining a predominant staining of the apical membrane could be observed. These observations indicate that biliary epithelial cells are involved in bile acid transport across the biliary tree. In addition the carrier could also play a role in the signal transduction of bile acid induced ductular secretion.

Influence of cholestasis on absorption of ursodeoxycholic acid

Ursodeoxycholic acid (UDCA) has beneficial effects in cholestatic liver diseases. Absorption of UDCA is slow and incomplete. In the present study the effect of cholestasis on absorption was evaluated in 10 patients with pancreatic carcinoma and extrahepatic biliary drainage. At days 3 and 10 after insertion of the biliary drain, all patients received 750 mg UDCA in three divided doses. On both occasions intestinal absorption of UDCA was determined to evaluate the influence of cholestasis. Serum bilirubin was used as indicator of cholestasis. Biliary output of UDCA served as measure of absorption and was determined by gas-liquid chromatography. At days 4 and 11 bile consisted of less than 2% of UDCA, indicating that UDCA excretion was complete within 24 hr and no accumulation of UDCA had occurred. After insertion of the drain, serum bilirubin decreased from 12.2 +/- 2.4 mg/dl at day 3 to 5.4 +/- 0.9 mg/dl at day 10. Biliary secretion of bile acids increased from 2.0 +/- 0.3 to 3.1 +/- 0.4 mmol/day, whereas percentage of ursodeoxycholic acid in bile did not significantly increase (41.1% vs 42.1%). Absorption of UDCA increased from 39.8 +/- 5.0% to 61.1 +/- 6.2% of the administered dose, indicating an improvement of the absorption rate after decrease of cholestasis by 53.65% (P < 0.05). In conclusion, in severe cholestasis absorption of orally administered UDCA is markedly reduced. This may have implications in the treatment of patients with cholestatic disease.

[Therapy of Wilson disease]

Wilson disease is a copper storage disease with autosomal-recessive trait that is predominantly a disorder of the adolescent and young adult. Clinical manifestations are dominated by hepatic and/or neurological symptoms. Diagnostic procedures include determination of total serum copper, free serum copper and serum ceruloplamin concentrations as well as urinary copper excretion. Confirmation of diagnosis may be achieved by liver biopsy and histological determination of copper content. The aim of treatment is reduction of tissue copper concentration and detoxification of copper. Drugs applied are the chelating agents. D-penicillamine and trientine, or zinc. The chelating agents induce renal and biliary copper excretion and increased synthesis of metallothionein, which attaches and detoxifies intracellular copper, leading to impaired absorption and binding of excess intracellular copper. Treatment with zinc results in induction of hepatic and intestinal metallothionein synthesis. Regular examinations of the parameters of copper metabolism are necessary in order to control the therapeutic effect. Free copper serum concentrations and urinary copper excretion should reach values below 10 micrograms/dl and 80 micrograms/day, respectively. A significant improvement of clinical symptoms and normalization of parameters of copper metabolism can be expected earliest six months after onset of therapy. Anti-copper treatment may be accompanied by copper-reduced diet. Lifelong therapy is required and provides life-expectancy near to normal. Interruption of treatment leads to reaccumulation of copper, often resulting in fulminant hepatic failure. This can also be observed as initial presentation in 5% of cases (predominant age 12 to 25 years). End stage liver disease and fulminant hepatic failure are indications for liver transplantation by which the genetic defect is phenotypically cured. Here decoppering treatment is no longer required. Whether severe neurological disorders may also be improved is not clear until today.

Clinical relevance of hepatitis G virus (HGV) infection in heart transplant patients

To investigate whether the recently discovered hepatitis G virus (HGV) influences the clinical outcome of heart transplant recipients under immunosuppression, we determined the prevalence of HGV infections correlated with liver function and survival in 51 patients. Presence of HGV RNA and anti-E2, a marker for resolved HGV infection, were serially tested in sera from patients before and after heart transplantation (HTX) by nested RT-PCR and ELISA. Four of 51 (7.8%) patients before transplantation, and 22 of 50 patients (44%) after transplantation showed signs of persistent or resolved HGV infection. HGV infection was not associated with impairment of liver function or with patient survival. In summary, presence of HGV infection does not influence the clinical outcome in heart transplant patients.