Helicobacter pylori infection, iNOS, and gastric cancer: the impact of another possible link.
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Helicobacter Infections↗
Biomedical subjects
Herbert Tilg
Publications and source records attributed to Herbert Tilg.
Management strategies in alcoholic liver disease.
Alcoholic liver disease (ALD) and its complications is still one of the most frequent causes of death in the Western world. Treatment modalities for both alcoholic steatohepatitis (ASH; the major inflammatory complication of ALD) and alcoholic liver cirrhosis are insufficient. Severe ASH is associated with a high mortality; although glucocorticoid treatment has been reported to improve survival, meta-analyses of clinical trials performed to date have failed to show a convincing benefit of such an approach. Most of the progress in understanding these diseases, especially ASH, has come from studies of cytokines. Various proinflammatory cytokines, such as tumor necrosis factor (TNF), have been proposed to have an important role in the pathophysiology of ALD and its complications. Pilot studies on the use of anti-TNF drugs, such as pentoxifylline or infliximab, in the treatment of ASH have now been performed with various levels of success. The treatment of patients with alcohol-related cirrhosis is mainly symptomatic and no therapies are currently available except orthotopic liver transplantation for end-stage liver disease. Independent of the stage of disease, abstinence from alcohol is the cornerstone of management. New treatment modalities for these diseases are eagerly awaited.
Fatty Liver↗
Adipocytokines: mediators linking adipose tissue, inflammation and immunity.
There has been much effort recently to define the role of adipocytokines, which are soluble mediators derived mainly from adipocytes (fat cells), in the interaction between adipose tissue, inflammation and immunity. The adipocytokines adiponectin and leptin have emerged as the most abundant adipocyte products, thereby redefining adipose tissue as a key component not only of the endocrine system, but also of the immune system. Indeed, as we discuss here, several adipocytokines have a central role in the regulation of insulin resistance, as well as many aspects of inflammation and immunity. Other adipocytokines, such as visfatin, have only recently been identified. Understanding this rapidly growing family of mainly adipocyte-derived mediators might be of importance in the development of new therapies for obesity-associated diseases.
Adiponectin↗
Gender and age specific differences in exhaled isoprene levels.
The analysis of volatile organic compounds (VOC) in the human breath has attracted a considerable amount of clinical and scientific interest during the last decade. In our study, we turned our attention to gender and age specific differences of exhaled volatile compounds, particularly on isoprene which is one of the most abundant organic molecules found in human exhaled air. A total of 126 test persons were enrolled in the study: 66 females and 60 males. Moreover, the participants were classified into six groups with regard to their age. In a standardized setting all of them had to exhale the endexpiratory breath into a sample bag. The volatile compounds at m/z values from 21 to 229 were analyzed by using proton-transfer-reaction-mass-spectrometry. Isoprene (at m/z 69) was found to be highly significantly (p<0.001) elevated in the exhaled air of male subjects. Furthermore, it could be shown that 19-29 years old subjects exhale significantly lower levels of isoprene than older adults (p=0.002). No significant differences between groups were detected for any other measured mass. In conclusion, the present study demonstrates gender and age specific differences of isoprene levels in the exhaled air. These findings may be of potential clinical relevance regarding the multifaceted roles of isoprene, representing both indicator and effector molecule.
Adult↗
Nonalcoholic fatty liver disease: Cytokine-adipokine interplay and regulation of insulin resistance.
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Adiponectin↗
Clinical challenges and images in GI. Pill esophagitis.
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Adult↗
Analysis of volatile compounds emitted by the Helicobacter pylori reference strain NCTC 11637 in vitro.
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Breath Tests↗
How to modulate inflammatory cytokines in liver diseases.
Most acute and chronic liver diseases are characterized by inflammatory processes with enhanced expression of various pro- and anti-inflammatory cytokines in the liver. These cytokines are the driving force of many inflammatory liver disorders often resulting in fibrosis and cirrhosis. Severe alcoholic hepatitis is a prototypic tumor necrosis factor-alpha (TNF-alpha)-associated disease. This knowledge has recently led to pilot studies with promising results investigating specific anti-TNF drugs such as infliximab or etanercept in the treatment of this disease, although a recently performed controlled French study did show a potential detrimental effect of this approach. Anti-TNF treatment strategies might also improve chronic hepatitis C infection as shown by one controlled trial using etanercept administered subcutaneously for 24 weeks. Furthermore, several case reports suggest that TNF-alpha neutralization is not harmful to patients chronically infected with this virus. In contrast, neutralization of TNF-alpha worsens and might even be associated with fatalities in chronic hepatitis B infection. Anti-inflammatory cytokines such as interleukin-10 (IL-10) have also been tried in patients with chronic liver diseases. Whereas IL-10 administered to patients with chronic hepatitis C virus infection shows indeed anti-inflammatory effects in the liver, it seems to act as a proviral agent thereby limiting its clinical utility. Another cytokine with major anti-inflammatory potential is the adipokine adiponectin, as its administration is beneficial in many experimental models of liver injury. Interference with cytokine pathways and/or administration of anti-inflammatory cytokines will be of major interest in the future therapy of many liver diseases.
Adiponectin↗
The effect of zoledronic acid on the function and differentiation of myeloid cells.
BACKGROUND AND OBJECTIVES: Bisphosphonates are widely used for treatment of osteoporosis and metastases of the skeletal system. Recent data suggest that bisphosphonates may not only reduce bone loss but also exert direct anti-tumor, anti-angiogenic and E inverted exclamation markE not T-cell activating effects, properties which depend at least partially on their affinity to phagocytosing and antigen-presenting cells (i.e. osteoclasts and monocytes). The latter represent the major source of dendritic cells (DC). Thus, we determined the immunomodulatory properties of zoledronic acid (ZA), a member of the latest generation of bisphosphonates. DESIGN AND METHODS: Primary human monocytes, macrophages, immature and mature dendritic cells were incubated with increasing doses of ZA for subsequent analysis of cell surface marker expression and cytokine production. In addition, phagocytic and allo-stimulatory properties, differentiation capacity, and NF-kB activation were determined. RESULTS: Therapeutic doses of ZA inhibited the in vitro generation of DC from monocytes, as shown by an impaired up-regulation of maturation markers. In parallel, ZA also impaired lipopolysaccharide-induced activation of NF-kB, which represents a critical factor for DC differentiation. Accordingly, the activation of allogeneic T cells by ZA-treated DC in a mixed-lymphocyte reaction was significantly reduced. Finally, ZA inhibited the production of tumor necrosis factor-a in monocyte-derived cells and impaired the phagocytic capacity of macrophages and immature DC. INTERPRETATION AND CONCLUSIONS: Therapeutic doses of ZA modulate monocyte, macrophage and DC function and might thereby modulate immune function.
Antigens, CD↗
Telomere length of in vivo expanded CD4(+)CD25 (+) regulatory T-cells is preserved in cancer patients.
PURPOSE: CD4(+)CD25(+) regulatory T-cells (Treg) are increased in the peripheral blood of cancer patients. It remains unclear whether this is due to redistribution or active proliferation. The latter would require the upregulation of telomerase activity, whose regulation also remains unknown for Treg. EXPERIMENTAL DESIGN: Treg and CD4(+)CD25(-) T-cells were isolated from peripheral blood of cancer patients (n=23) and healthy age-matched controls (n=17) and analyzed for their content of T-cell receptor excision circles (TREC) and for telomere length using flow-FISH, real-time PCR and Southern blotting. The in vitro regulation of telomerase of Treg was studied using PCR-ELISA in bulk cultures as well as in isolated proliferating and non-proliferating Treg. RESULTS: Treg isolated from peripheral blood of cancer patients exhibit significantly decreased levels of TREC when compared to Treg from healthy controls. Despite their in vivo proliferation, telomere length is not further shortened in Treg from cancer patients. Accordingly, telomerase activity of Treg was readily inducible in vitro. Notably, sorting of in vitro proliferating Treg revealed a significant telomere shortening in Treg with high-proliferative capacity. The latter are characterized by shortened telomeres despite high telomerase activity. CONCLUSIONS: Increased frequencies of Treg in peripheral blood of cancer patients are due to active proliferation rather than due to redistribution from other compartments (i.e., secondary lymphoid organs or bone marrow). In vivo expansion does not further shorten telomere length, probably due to induction of telomerase activity. In contrast, under conditions of strong in vitro stimulation telomerase induction seems to be insufficient to avoid progressive telomere shortening.
Aged↗
Up-regulation of the anti-inflammatory adipokine adiponectin in acute liver failure in mice.
BACKGROUND/AIMS: Recent reports suggest that the adipose tissue and adipokines are potent modulators of inflammation. However, there is only scarce knowledge on the functional role and regulation of endogenous adiponectin in non-fat tissues such as the liver under conditions of acute inflammation. METHODS: In the present study, we investigated adiponectin expression in healthy murine liver tissue and under inflammatory conditions in vivo. RESULTS: Adiponectin mRNA was readily detectable in healthy liver tissue and further increased in ConA-mediated acute liver failure. Adiponectin protein expression was mainly found in hepatic endothelial cells. In vitro adiponectin mRNA expression was detectable in several cell types, including primary hepatic sinusoidal endothelial cells, stellate cells, and macrophages. Mice pretreated with adiponectin before ConA administration developed reduced hepatic injury as shown by decreased release of transaminases and reduced hepatocellular apoptotis. Of note, TNF-alpha levels were not affected by adiponectin, whereas IL-10 production was increased. Neutralisation of IL-10 diminished the protective effect of adiponectin. CONCLUSIONS: Adiponectin expression is up-regulated in ConA-mediated acute liver failure. Therefore, adiponectin might play a role in the control and limitation of inflammation in the liver. Moreover, our data suggest a role for IL-10 in adiponectin-mediated hepatoprotection.
Adiponectin↗
The kinase inhibitor imatinib mesylate inhibits TNF-{alpha} production in vitro and prevents TNF-dependent acute hepatic inflammation.
Imatinib exerts potent antileukemic effects in vitro and in vivo. Despite its well known antitumor activity, the potential of imatinib for the treatment of inflammatory diseases remains elusive so far. Our current report provides strong evidence that imatinib has potent antiinflammatory effects. It potently inhibits LPS- and Con A-induced TNF-alpha production by human myeloid cells in vitro (peripheral blood mononuclear cells, CD14-selected monocytes, and monocyte-derived macrophages). Of note, the production of the antiinflammatory cytokine IL-10 was not significantly regulated by imatinib. In line with this observation, phosphorylation of IkappaB and subsequent DNA binding of NF-kappaB, which is critically involved in TNF-alpha, but not IL-10 expression, was reduced by imatinib. Using several murine models of acute hepatitis, we could corroborate our in vitro findings, as imatinib prevented macrophage- and TNF-alpha-dependent inflammatory damage of the liver induced by injection of either Con A or d-galactosamine/LPS by inhibition of hepatic TNF-alpha production. Of note, d-galactosamine/TNF-induced hepatitis was not affected, showing that imatinib does not directly inhibit TNF-alpha-induced hepatocellular cell death. These findings suggest a potent antiinflammatory role of imatinib by modulation of TNF-alpha production in monocytes/macrophages. This observation might be of therapeutic value for the treatment of TNF-mediated diseases.
Animals↗
Role of nuclear receptors and hepatocyte-enriched transcription factors for Ntcp repression in biliary obstruction in mouse liver.
Expression of the main hepatic bile acid uptake system, the Na+-taurocholate cotransporter (Ntcp), is downregulated during cholestasis. Bile acid-induced, farnesoid X receptor (FXR)-mediated induction of the nuclear repressor short heterodimer partner (SHP) has been proposed as a key mechanism reducing Ntcp expression. However, the role of FXR and SHP or other nuclear receptors and hepatocyte-enriched transcription factors in mediating Ntcp repression in obstructive cholestasis is unclear. FXR knockout (FXR-/-) and wild-type (FXR+/+) mice were subjected to common bile duct ligation (CBDL). Cholic acid (CA)-fed and LPS-treated FXR-/- and FXR+/+ mice were studied for comparison. mRNA levels of Ntcp and SHP and nuclear protein levels of hepatocyte nuclear factor (HNF)-1alpha, HNF-3beta, HNF-4alpha, retinoid X receptor (RXR)-alpha, and retinoic acid receptor (RAR)-alpha and their DNA binding were assessed. Hepatic cytokine mRNA levels were also measured. CBDL and CA led to Ntcp repression in FXR+/+, but not FXR-/-, mice, whereas LPS reduced Ntcp expression in both genotypes. CBDL and LPS but not CA induced cytokine expression and reduced levels of HNF-1alpha, HNF-3beta, HNF-4alpha, RXRalpha, and RARalpha to similar extents in FXR+/+ and FXR-/-. DNA binding of these transactivators was unaffected by CA in FXR+/+ mice but was markedly reduced in FXR-/- mice. In conclusion, Ntcp repression by CBDL and CA is mediated by accumulating bile acids via FXR and does not depend on cytokines, whereas Ntcp repression by LPS is independent of FXR. Reduced levels of HNF-1alpha, RXRalpha, and RARalpha in CBDL FXR-/- mice and reduced DNA binding in CA-fed FXR-/- mice, despite unchanged Ntcp levels, indicate that these factors may have a minor role in regulation of mouse Ntcp during cholestasis.
Animals↗
The RANKL/OPG system and bone mineral density in patients with chronic liver disease.
BACKGROUND/AIMS: Osteopenia and osteoporosis are common complications of chronic liver disease (CLD). Receptor activator of nuclear factor kappaB ligand (RANKL) and osteoprotegerin (OPG) regulate osteoclastogenesis and bone remodelling, and are involved in several inflammatory diseases. This study investigated the activation state of the RANKL/OPG system and its association with bone loss in CLD. METHODS: Serum levels of OPG and sRANKL were determined in 193 patients with CLD and 56 age- and gender-matched healthy controls. Cellular sources of OPG and RANKL were determined immunohistochemically. Dual-energy x-ray absorptiometry was performed to determine bone mineral density (BMD) of lumbar spine and femoral neck. RESULTS: sRANKL serum levels were significantly elevated in non-cirrhotic, but not cirrhotic patients compared to healthy controls. OPG serum levels were elevated 1.6-fold in non-cirrhotic and 2.8-fold in cirrhotic CLD patients. RANKL+ cells were mainly confined to portal fields, while OPG was broadly expressed. In the cirrhotic subgroup (87 patients) we observed a significantly higher OPG/sRANKL ratio in patients with osteopenia or osteoporosis of the lumbar spine and femoral neck region (T-score < -1) compared to those with normal BMD (T-score > or = -1). CONCLUSIONS: CLD is associated with alterations in RANKL/OPG serum levels, which could modulate bone loss in CLD.
Adult↗
Adiponectin and its receptors in patients with chronic hepatitis C.
BACKGROUND/AIMS: There is increasing interest in the influence of excess body weight and associated metabolic factors on the liver. In patients with non-alcoholic steatohepatitis, lower levels of adiponectin were associated with higher grades of hepatic steatosis and necroinflammatory activity, suggesting a pathophysiological role for this adipokine in liver disease. METHODS: We studied 194 consecutive patients with untreated chronic HCV, to assess the relationship between adiponectin and its receptors and hepatic steatosis, fibrosis and inflammation. RESULTS: Significant negative correlations between serum adiponectin and male gender, body mass index and serum insulin were observed. However, there was no association between serum adiponectin and stage of fibrosis and lower levels of serum adiponectin were associated with the presence of steatosis in males only. In contrast, there was a significant increase in serum adiponectin and hepatic adiponectin immunoreactivity with increasing inflammation. The hepatic mRNA expression of the adiponectin receptors, AdipoR1 and AdipoR2, displayed significant but opposite associations with phosphoenolpyruvate carboxykinase (PEPCK) gene expression, a substitute marker of hepatic insulin sensitivity. CONCLUSIONS: In patients with chronic HCV, adiponectin was associated with steatosis only in males and was paradoxically increased with inflammation. Our results suggest that the role of adiponectin in chronic liver diseases may be linked to gender and etiology.
Adiponectin↗
CD4+CD25+ regulatory T cells inhibit experimental anti-glomerular basement membrane glomerulonephritis in mice.
CD4+CD25+ regulatory T cells (Treg) are of critical importance for the maintenance of tolerance. The kidney is frequently involved in autoimmune diseases, such as lupus erythematosus or glomerulonephritis (GN). Therefore, the therapeutic efficacy of Treg in a T cell-dependent murine model of experimental anti-glomerular basement membrane (anti-GBM) GN was tested. Transfer of 1 x 10(6) CD4+CD25+ T cells (day -1) into mice that were previously immunized with rabbit IgG (day -3) and subsequently received an injection of anti-GBM rabbit serum (day 0) significantly attenuated the development of proteinuria when compared with animals that received an injection of 1 x 10(6) CD4+CD25- T cells (control group). Treg injection induced a dramatic decrease of glomerular damage as well as a marked decrease of CD4+ T cell, CD8+ T cell, and macrophage infiltration. Of note, deposition of immune complexes was not prevented by Treg, showing that Treg rather inhibited cell-mediated organ damage than priming of the humoral immune response. Accordingly, a significant reduction of IFN-gamma, TNF-alpha, and TGF-beta1 mRNA in kidneys from animals that received Treg injection was observed. Tracking of enhanced green fluorescence protein-transgenic Treg revealed a predominant migration to secondary lymphoid organs with a significant increase of regulatory T cells (CD4+CD25+CD69-CD45RB(low)) in the lymph nodes. In contrast, enhanced green fluorescence protein-and FoxP3-positive cells by reverse transcription-PCR and CD4+CD25+CD69-CD45RB(low) T cells by flow cytometry in the kidney of nephritic animals were not detected. This report provides first evidence that Treg are potent suppressors of anti-GBM GN. Treg therefore might be of therapeutic value for the treatment of severe GN in humans.
Adoptive Transfer↗
Neurokinin-1 receptor interacts with PrP(106-126)-induced dendritic cell migration and maturation.
Circulating monocytic cells may mediate neuroinvasion in transmissible spongiform encephalopathies by transporting prion protein (PrP) from sites of entry to the nervous system. Factors regulating monocyte-derived dendritic cell (DC) functions in neuronal tissue include neurogenic mediators, but their interactions with prion-infected DCs are unknown. Here, we report that neuropeptides regulate the interaction of DCs exposed to PrP(106-126). Inhibition of neurokinin-1-receptors activation with neurokinin-1-receptor antagonist or antibody attenuates substance P-induced enhancement of DC migration induced by PrP(106-126) and prion-protein-induced DC maturation. Other neuropeptides arrest chemotaxis. Data support a priming role of the neuropeptide substance P in PrP(106-126)-induced migration of DCs involving neurokinin-1-receptors.
Antibodies↗
Treatment strategies in nonalcoholic fatty liver disease.
Nonalcoholic fatty liver disease (NAFLD) is an increasingly recognized health problem. Increased fat accumulation in the liver is observed in 20-30% of the population in the Western world, and in approximately 10% of this cohort it is associated with nonalcoholic steatohepatitis, which is characterized by inflammation and fibrosis. Disease presentation of NAFLD ranges from asymptomatic disease to cirrhosis with the complication of liver failure and hepatocellular carcinoma. NAFLD is suspected on the basis of various clinical aspects (an elevated alanine aminotransferase concentration, presence of obesity and diabetes) that alone are not sufficient to establish diagnosis or prognosis. The major diagnostic procedure is liver biopsy, which allows assessment of liver injury. In most cases, NAFLD is associated with insulin resistance, which is therefore the target of most current NAFLD treatment modalities. Various treatment strategies such as weight loss and/or exercise, thiazolidinediones, metformin, lipid-lowering agents and antioxidants have been studied. So far, no single intervention has convincingly improved liver histology. It is recommended that patients at high risk of developing advanced liver disease, and who are not part of controlled studies, should receive nutritional counseling and take physical exercise to achieve moderate weight loss and improve insulin sensitivity.
Angiotensin II Type 1 Receptor Blockers↗