AIM:To evaluate the ability of endoscopic ultrasound(EUS) elastography to distinguish benign from malignant pancreatic masses and lymph nodes.METHODS:A multicenter study was conducted and included 222 patients who und...AIM:To evaluate the ability of endoscopic ultrasound(EUS) elastography to distinguish benign from malignant pancreatic masses and lymph nodes.METHODS:A multicenter study was conducted and included 222 patients who underwent EUS examination with assessment of a pancreatic mass(n=121) or lymph node(n=101).The classification as benign or malignant,based on the real time elastography pattern,was compared with the classif ication based on the B-mode EUS images and with the fi nal diagnosis obtained by EUS-guided fi ne needle aspiration(EUS-FNA) and/or by surgical pathology.An interobserver study was performed.RESULTS:The sensitivity and specificity of EUS elastography to differentiate benign from malignant pancreatic lesions are 92.3% and 80.0%,respectively,compared to 92.3% and 68.9%,respectively,for the conventional B-mode images.The sensitivity and specificity of EUS elastography to differentiate benign from malignant lymph nodes was 91.8% and 82.5%,respectively,compared to 78.6% and 50.0%,respectively,for the B-mode images.The kappa coefficient was 0.785 for the pancreatic masses and 0.657 for the lymph nodes.CONCLUSION:EUS elastography is superior compared to conventional B-mode imaging and appears to be able to distinguish benign from malignant pancreatic masses and lymph nodes with a high sensitivity,specificity and accuracy.It might be reserved as a second line examination to help characterise pancreatic masses after negative EUS-FNA and might increase the yield of EUS-FNA for lymph nodes.展开更多
AIM: To study the role of advanced glycation end products (AGE) and their specific receptor (RAGE) in the pathogenesis of liver fibrogenesis. METHODS: In vitro RAGE expression and extracellular matrix-related ge...AIM: To study the role of advanced glycation end products (AGE) and their specific receptor (RAGE) in the pathogenesis of liver fibrogenesis. METHODS: In vitro RAGE expression and extracellular matrix-related gene expression in both rat and human hepatic stellate cells (HSC) were measured after stimulation with the two RAGE ligands, advanced glycation end product-bovine serum albumin (AGE- BSA) and N'-(carboxymethyl) lysine (CML)-BSA, or with tumor necrosis factor-α (TNF-α). In vivo RAGE expression was examined in models of hepatic fibrosis induced by bile duct ligation or thioacetamide. The effects of AGE-BSA and CML-BSA on HSC proliferation, signal transduction and profibrogenic gene expression were studied in vitro. RESULTS: In hepatic fibrosis, RAGE expression was enhanced in activated HSC, and also in endothelial cells, inflammatory cells and activated bile duct epithelia. HSC expressed RAGE which was upregulated after stimulation with AGE-BSA, CML-BSA, and TNF-α.RAGE stimulation with AGE-BSA and CML-BSA did not alter HSC proliferation, apoptosis, fibrogenic signal transduction and fibrosis- or fibrolysis-related gene expression, except for marginal upregulation of procollagen α1( I ) mRNA by AGE-BSA. CONCLUSION: Despite upregulation of RAGE in activated HSC, RAGE stimulation by AGE does not alter their fibrogenic activation. Therefore, RAGE does not contribute directly to hepatic fibrogenesis.展开更多
MM: Persistent cholestasis is a rare complication of severe trauma or infections. Little is known about the possible pathomechanisms and the clinical course.METHODS: Secondary sclerosing cholangitis was diagnosed in...MM: Persistent cholestasis is a rare complication of severe trauma or infections. Little is known about the possible pathomechanisms and the clinical course.METHODS: Secondary sclerosing cholangitis was diagnosed in five patients with persistent jaundice after severe trauma (one burn injury, three accidents, one power current injury). Medical charts were retrospectively reviewed with regard to possible trigger mechanisms for cholestasis, and the clinical course was recorded.RESULTS: Diagnosis of secondary sclerosing cholangitis was based in all patients on the primary sclerosing cholangitis (PSC)-Iike destruction of the intrahepatic bile ducts at cholangiography after exclusion of PSC. In four patients, arterial hypotension with subsequent ischemia may have caused the bile duct damage, whereas in the case of power current injury direct thermal damage was assumed to be the trigger mechanism. The course of secondary liver fibrosis was rapidly progressive and proceeded to liver cirrhosis in all four patients with a follow-up 〉2 years. Therapeutic possibilities were limited.CONCLUSION: Posttraumatic sderosing cholangitis is a rare but rapidly progressive disease, probably caused by ischemia of the intrahepatic bile ducts via the peribiliary capillary plexus due to arterial hypotension.Gastroenterologists should be aware of this disease in patients with persistent cholestasis after severe trauma.展开更多
The current World Health Organization classification system of primary brain tumors is solely based on morphologic criteria. However, there is accumulating evidence that tumors with similar histology have distinct mol...The current World Health Organization classification system of primary brain tumors is solely based on morphologic criteria. However, there is accumulating evidence that tumors with similar histology have distinct molecular signatures that significantly impact treatment response and survival. Recent practice-changing clinical trials have defined a role for routine assessment of O-6-methylguanine-DNA methyltransferase(MGMT) promoter methylation in glioblastoma patients, especially in the elderly, and 1p and 19q codeletions in patients with anaplastic glial tumors. Recently discovered molecular alterations including mutations in IDH-1/2, epidermal growth factor receptor(EGFR), and BRAF also have the potential to become targets for future drug development. This article aims to summarize current knowledge on the molecular biology of high-grade gliomas relevant to daily practice.展开更多
Causality assessment of suspected drug induced liver injury(DILI) and herb induced liver injury(HILI) is hampered by the lack of a standardized approach to be used by attending physicians and at various subsequent eva...Causality assessment of suspected drug induced liver injury(DILI) and herb induced liver injury(HILI) is hampered by the lack of a standardized approach to be used by attending physicians and at various subsequent evaluating levels. The aim of this review was to analyze the suitability of the liver specific Council for International Organizations of Medical Sciences(CIOMS) scale as a standard tool for causality assessment in DILI and HILI cases. PubMed database was searched for the following terms: drug induced liver injury; herb induced liver injury; DILI causality assessment; and HILI causality assessment. The strength of the CIOMS lies in its potential as a standardized scale for DILI and HILI causality assessment. Other advantages include its liver specificity and its validation for hepatotoxicity with excellent sensitivity, specificity and predictive validity, based on cases with a positive reexposure test. This scale allows prospective collection of all relevant data required for a valid causality assessment. It does not require expert knowledge in hepatotoxicity and its results may subsequently be refined. Weaknesses of the CIOMS scale include the limited exclusion of alternative causes and qualitatively graded risk factors. In conclusion, CIOMS appears to be suitable as a standard scale for attending physicians, regulatory agencies, expert panels and other scientists to provide a standardized, reproducible causality assessment in suspected DILI and HILI cases, applicable primarily at all assessing levels involved. 2014 Baishideng Publishing Group Co., Limited. All展开更多
The diagnosis of herbal hepatotoxicity or herb induced liver injury(HILI) represents a particular clinical and regulatory challenge with major pitfalls for the causality evaluation.At the day HILI is suspected in a pa...The diagnosis of herbal hepatotoxicity or herb induced liver injury(HILI) represents a particular clinical and regulatory challenge with major pitfalls for the causality evaluation.At the day HILI is suspected in a patient,physicians should start assessing the quality of the used herbal product,optimizing the clinical data for completeness,and applying the Council for International Organizations of Medical Sciences(CIOMS) scale for initial causality assessment.This scale is structured,quantitative,liver specific,and validated for hepatotoxicity cases.Its items provide individual scores,which together yield causality levels of highly probable,probable,possible,unlikely,and excluded.After completion by additional information including raw data,this scale with all items should be reported to regulatory agencies and manufacturers for further evaluation.The CIOMS scale is preferred as tool for assessing causality in hepatotoxicity cases,compared to numerous other causality assessment methods,which are inferior on various grounds.Among these disputed methods are the Maria and Victorino scale,an insufficiently qualified,shortened version of the CIOMS scale,as well as various liver unspecific methods such as thead hoc causality approach,the Naranjo scale,the World Health Organization(WHO) method,and the Karch and Lasagna method.An expert panel is required for the Drug Induced Liver Injury Network method,the WHO method,and other approaches based on expert opinion,which provide retrospective analyses with a long delay and thereby prevent a timely assessment of the illness in question by the physician.In conclusion,HILI causality assessment is challenging and is best achieved by the liver specific CIOMS scale,avoiding pitfalls commonly observed with other approaches.展开更多
AIM:To analyze the pathogenetic role and potential clinical usefulness of the epidermal growth factor receptor(EGFR)and the human epidermal growth factor receptor 2(HER2)in patients with advanced biliary tract cancer(...AIM:To analyze the pathogenetic role and potential clinical usefulness of the epidermal growth factor receptor(EGFR)and the human epidermal growth factor receptor 2(HER2)in patients with advanced biliary tract cancer(BTC). METHODS:EGFR and HER2 expression was studied in biopsy samples from 124 patients(51%women; median age 64.8 years),with advanced BTC diagnosed between 1997 and 2004.Five micrometers sections of paraffin embedded tissue were examined by standard, FDA approved immunohistochemistry.Tumors with scores of 2+or 3+for HER2 expression on immunochemistry were additionally tested for HER2 gene amplification by fluorescence in situ hybridisation(FISH).RESULTS:34/124 patients(27.4%)had gallbladder cancer,47(37.9%)had intrahepatic BTC and 43(34.7%)had extrahepatic or perihilar BTC.EGFR expression was examined in a subset of 56 samples. EGFR expression was absent in 22/56 tumors(39.3%). Of the remaining samples expression was scored as 1+in 12(21.5%),2+in 13(23.2%)and 3+in 9(16%), respectively.HER2 expression was as follows:score 0 73/124(58.8%),score 1+27/124(21.8%),score 2+ 21/124(17%)and score 3+4/124(3.2%).HER2 gene amplification was present in 6/124,resulting in an overall amplification rate of 5%. CONCLUSION:Our data suggest that routine testing and therapeutic targeting of HER2 does not seem to be useful in patients with BTC,while targeting EGFR may be promising.展开更多
AIM: To analyze the validity of applied test criteria and causality assessment methods in assumed Herbalife hepatotoxicity with positive reexposure tests. METHODS: We searched the Medline database for suspected cases ...AIM: To analyze the validity of applied test criteria and causality assessment methods in assumed Herbalife hepatotoxicity with positive reexposure tests. METHODS: We searched the Medline database for suspected cases of Herbalife hepatotoxicity and retrieved 53 cases including eight cases with a positive unintentional reexposure and a high causality level for Herbalife. First, analysis of these eight cases focused on the data quality of the positive reexposure cases, requiring a baseline value of alanine aminotransferase(ALT) < 5 upper limit of normal (N) before reexposure, with Nas the upper limit of normal, and a doubling of the ALT value at reexposure as compared to the ALT value at baseline prior to reexposure. Second, reported methods to assess causality in the eight cases were evaluated, and then the liver specific Council for International Organizations of Medical Sciences (CIOMS) scale validated for hepatotoxicity cases was used for quantitative causality reevaluation. This scale consists of various specific elements with scores provided through the respective case data, and the sum of the scores yields a causality grading for each individual case of initially suspected hepatotoxicity. RESULTS: Details of positive reexposure test conditions and their individual results were scattered in virtually all cases, since reexposures were unintentional and allowed only retrospective rather than prospective assessments. In 1/8 cases, criteria for a positive reexposure were fulfilled, whereas in the remaining cases the reexposure test was classified as negative (n = 1), or the data were considered as uninterpretable due to missing information to comply adequately with the criteria (n = 6). In virtually all assessed cases, liver unspecific causality assessment methods were applied rather than a liver specific method such as the CIOMS scale. Using this scale, causality gradings for Herbalife in these eight cases were probable (n = 1), unlikely (n = 4), and excluded (n = 3). Confounding variables in- cluded low data quality, alternative diagnoses, poor exclusion of important other causes, and comedication by drugs and herbs in 6/8 cases. More specifically, problems were evident in some cases regarding temporal association, daily doses, exact start and end dates of product use, actual data of laboratory parameters such as ALT, and exact dechallenge characteristics. Short-comings included scattered exclusion of hepatitis A-C, cytomegalovirus and Epstein Barr virus infection with only globally presented or lacking parameters. Hepatitis Evirus infection was considered in one single patient and found positive, infections by herpes simplexvirus and varicella zoster virus were excluded in none. CONCLUSION: Only one case fulfilled positive reexposure test criteria in initially assumed Herbalife hepatotoxicity, with lower CIOMS based causality gradings for the other cases than hitherto proposed.展开更多
AIM: This study evaluated colorectal mucosal histamine release in response to blinded food challenge-positive and-negative food antigens as a new diagnostic procedure. METHODS: 19 patients suffering from gastrointes...AIM: This study evaluated colorectal mucosal histamine release in response to blinded food challenge-positive and-negative food antigens as a new diagnostic procedure. METHODS: 19 patients suffering from gastrointestinally mediated allergy confirmed by blinded oral provocation were investigated on grounds of their case history, skin prick tests, serum IgE detection and colorectal mucosal histamine release by ex vivo mucosa oxygenation. Intact tissue particles were incubated/stimulated in an oxygenated culture with different food antigens for 30 min. Specimens challenged with anti-human immunoglobulin E and without any stimulus served as positive and negative controls, respectively. Mucosal histamine release (% of total biopsy histamine content) was considered successful (positive), when the rate of histamine release from biopsies in response to antigens reached more than twice that of the spontaneous release. Histamine measurement was performed by radioimmunoassay. RESULTS: The median (range) of spontaneous histamine release from colorectal mucosa was found to be 3.2 (0.1%-25.8%) of the total biopsy histamine content. Food antigens tolerated by oral provocation did not elicit mast cell degranulation 3.4 (0.4%-20.7%, P=0.4), while anti-IgE and causative food allergens induced a significant histamine release of 5.4 (1.1%-25.6%, P = 0.04) and 8.1 (1.5%-57.9%, P = 0.008), respectively. 12 of 19 patients (63.1%) showed positive colorectal mucosal histamine release in accordance with the blinded oral challenge responding to the same antigen (s), while the specificity of the functional histamine release to accurately recognise tolerated foodstuffs was found to be 78.6%. In comparison with the outcome of blinded food challenge tests, sensitivity and specificity of history (30.8% and 57.1%), skin tests (47.4% and 78.6%) or antigen-specific serum IgE determinations (57.9% and 50%) were found to be of lower diagnostic accuracy in gastrointestinally mediated allergy. CONCLUSION: Functional testing of the reactivity of colorectal mucosa upon antigenic stimulation in patients with gastrointestinally mediated allergy is of higher diagnostic efficacy.展开更多
To evaluate prospectively 4 selected serum fibrosis markers (tenascin, hyaluronan, collagen Ⅵ, TIMP-1) before, during and 12 mo after IFN treatment of children with chronic hepatitis B. METHODS: Forty-seven consec...To evaluate prospectively 4 selected serum fibrosis markers (tenascin, hyaluronan, collagen Ⅵ, TIMP-1) before, during and 12 mo after IFN treatment of children with chronic hepatitis B. METHODS: Forty-seven consecutive patients with chronic hepatitis B (range 4-16 years, mean 8 years) underwent IFN treatment (3 MU tiw for 20 wk). Fibrosis stage and inflammation grade were assessed in a blinded fashion before and 12 mo after end of treatment. Serum fibrosis markers were determined using automated assays.RESULTS: IFN treatment improved histological inflammation but did not change fibrosis in the whole group or in subgroups. Only hyaluronan correlated significantly with histological fibrosis(r = 0.3383, P = 0.022). Basal fibrosis markers did not differ between responders (42.5%) and nonresponders(57.5%). During IFN treatment only serum tenascin decreased significantly in the whole group and in nonresponders. When pretreatment values were compared to values 12 mo after therapy, TIMP-1 increased in all patients and in nonresponders, and hyaluronan decreased in all patients and in responders.CONCLUSION: Tenascin reflects hepatic fibrogenesis and inflammation which decreases during IFN treatment of children with chronic hepatitis B. TIMP-1 correlates with nonresponse and hyaluronan with histological fibrosis.展开更多
The question whether epithelial-mesenchymal transition (EMT) occurs during liver fibrogenesis is a controversial issue. In vitro studies confirm that hepatocytes or cholangiocytes undergo EMT upon transforming growth ...The question whether epithelial-mesenchymal transition (EMT) occurs during liver fibrogenesis is a controversial issue. In vitro studies confirm that hepatocytes or cholangiocytes undergo EMT upon transforming growth factor beta (TGF-beta) stimulation, whereas in vivo experiments based on genetic fate mapping of specific cell populations suggest that EMT does not occur in fibrotic animal models. In this review we present current data supporting or opposing EMT in chronic liver disease and discuss conditions for the occurrence of EMT in patients. Based on the available data and our clinical observations we hypothesize that EMT-like alterations in liver cirrhosis are a side effect of high levels of TGF-beta and other pro-fibrotic mediators rather than a biological process converting functional parenchyma, i.e., hepatocytes, into myofibroblasts at a time when essential liver functions are deteriorating.展开更多
AIM: To study the interleukin-1(IL-1) pathway as a therapeutic target for liver fibrosis in vitro and in vivo using the ATP-binding cassette transporter b4^(-/-)(Abcb4^(-/-)) mouse model.METHODS: Female and male Abcb4...AIM: To study the interleukin-1(IL-1) pathway as a therapeutic target for liver fibrosis in vitro and in vivo using the ATP-binding cassette transporter b4^(-/-)(Abcb4^(-/-)) mouse model.METHODS: Female and male Abcb4^(-/-) mice from 6 to 13 mo of age were analysed for the degree of cholestasis(liver serum tests), extent of liver fibrosis(hydroxyproline content and Sirius red staining) and tissue-specific activation of signalling pathways such as the IL-1 pathway [quantitative polymerase chain reaction(q PCR)]. For in vivo experiments, murine hepatic stellate cells(HSCs) were isolated via pronasecollagenase perfusion followed by density gradient centrifugation using female mice. Murine HSCs were stimulated with up to 1 ng/m L IL-1β with or without 2.5 μg/m L Anakinra, an IL-1 receptor antagonist, respectively. The proliferation of murine HSCs was assessed via the Brd U assay. The toxicity of Anakinra was evaluated via the fluorescein diacetate hydrolysis(FDH) assay. In vivo 8-wk-old Abcb4^(-/-) mice with an already fully established hepatic phenotype were treated with Anakinra(1 mg/kg body-weight daily intraperitoneally) or vehicle and liver injury and liver fibrosis were evaluated via serum tests, q PCR, hydroxyproline content and Sirius red staining. RESULTS: Liver fibrosis was less pronounced in males than in female Abcb4^(-/-) animals as defined by a lower hydroxyproline content(274 ± 64 μg/g vs 436 ± 80 μg/g liver, respectively; n = 13-15; P < 0.001; MannWhitney U-test) and lower m RNA expression of the profibrogenic tissue inhibitor of metalloproteinase-1(TIMP)(1 ± 0.41 vs 0.66 ± 0.33 fold, respectively; n = 13-15; P < 0.05; Mann-Whitney U-test). Reduced liver fibrosis was associated with significantly lower levels of F4/80 m RNA expression(1 ± 0.28 vs 0.71 ± 0.41 fold, respectively; n = 12-15; P < 0.05; Mann-Whitney U-test) and significantly lower IL-1β m RNA expression levels(1 ± 0.38 vs 0.44 ± 0.26 fold, respectively; n = 13-15; P < 0.001; Mann-Whitney U-test). No gender differences in the serum liver parameters [bilirubin; alanine aminotransferase(ALT); aspartate aminotransferase and alkaline phosphatase(AP)] were found. In vitro, the administration of IL-1β resulted in a significant increase in HSC proliferation [0.94 ± 0.72 arbitrary units(A.U.) in untreated controls, 1.12 ± 0.80 A.U. at an IL-1β concentration of 0.1 ng/m L and 1.18 ± 0.73 A.U. at an IL-1β concentration of 1 ng/m L in samples from n = 6 donor animals; P < 0.001; analyses of variance(ANOVA)]. Proliferation was reduced significantly by the addition of 2.5 μg/m L Anakinra(0.81 ± 0.60 A.U. in untreated controls, 0.92 ± 0.68 A.U. at an IL-1β concentration of 0.1 ng/m L, and 0.91 ± 0.69 A.U. at an IL-1β concentration of 1 ng/m L; in samples from n = 6 donor animals; P < 0.001; ANOVA) suggesting an anti-proliferative effect of this clinically approved IL-1 receptor antagonist. The FDH assay showed this dose to be non-toxic in HSCs. In vivo, Anakinra had no effect on the hepatic hydroxyprolinecontent, liver serum tests(ALT and AP) and profibrotic(collagen 1α1, collagen 1α2, transforming growth factor-β, and TIMP-1) and anti-fibrotic [matrix metalloproteinase 2(MMP2), MMP9 and MMP13 ] gene expression after 4 wk of treatment. Furthermore, the hepatic IL-1β and F4/80 m RNA expression levels were unaffected by Anakinra treatment.CONCLUSION: IL-1β expression is associated with the degree of liver fibrosis in Abcb4^(-/-) mice and promotes HSC proliferation. IL-1 antagonism shows antifibrotic effects in vitro but not in Abcb4^(-/-) mice.展开更多
Chronic intestinal failure(CIF)is a rare but feared complication of Crohn’s disease.Depending on the remaining length of the small intestine,the affected intestinal segment,and the residual bowel function,CIF can res...Chronic intestinal failure(CIF)is a rare but feared complication of Crohn’s disease.Depending on the remaining length of the small intestine,the affected intestinal segment,and the residual bowel function,CIF can result in a wide spectrum of symptoms,from single micronutrient malabsorption to complete intestinal failure.Management of CIF has improved significantly in recent years.Advances in home-based parenteral nutrition,in particular,have translated into increased survival and improved quality of life.Nevertheless,60%of patients are permanently reliant on parenteral nutrition.Encouraging results with new drugs such as teduglutide have added a new dimension to CIF therapy.The outcomes of patients with CIF could be greatly improved by more effective prevention,understanding,and treatment.In complex cases,the care of patients with CIF requires a multidisciplinary approach involving not only physicians but also dietitians and nurses to provide optimal intestinal rehabilitation,nutritional support,and an improved quality of life.Here,we summarize current literature on CIF and short bowel syndrome,encompassing epidemiology,pathophysiology,and advances in surgical and medical management,and elucidate advances in the understanding and therapy of CIF-related complications such as catheter-related bloodstream infections and intestinal failure-associated liver disease.展开更多
AIM: Grapefruit-seed extract (GSE) containing flavonoids, possesses antibacterial and antioxidative properties but whether it influences the gastric defense mechanism and gastroprotection against ethanol- and stres...AIM: Grapefruit-seed extract (GSE) containing flavonoids, possesses antibacterial and antioxidative properties but whether it influences the gastric defense mechanism and gastroprotection against ethanol- and stress-induced gastric lesions remains unknown. METHODS: We compared the effects of GSE on gastric mucosal lesions induced in rats by topical application of 100% ethanol or 3.5 h of water immersion and restraint stress (WRS) with or without (A) inhibition of cyclooxygenase (COX)-1 activity by indomethacin and rofecoxib, the selective COX-2 inhibitor, (B) suppression of NO-synthase with L-NNA (20 mg/kg ip), and (C) inactivation by capsaicin (125 mg/kg sc) of sensory nerves with or without intragastric (ig) pretreatment with GSE applied 30 min prior to ethanol or WRS. One hour after ethanol and 3.5 h after the end of WRS, the number and area of gastric lesions were measured by planimetry, the gastric blood flow (GBF) was assessed by H2-gas clearance technique and plasma gastrin levels and the gastric mucosal generation of PGE2, superoxide dismutase (SOD) activity and malonyldialdehyde (MDA) concentration, as an index of lipid peroxidation were determined. RESULTS: Ethanol and WRS caused gastric lesions accompanied by the significant fall in the GBF and SOD activity and the rise in the mucosal MDA content. Pretreatment with GSE (8-64 mg/kg i g) dose- dependently attenuated gastric lesions induced by 100% ethanol and WRS; the dose reducing these lesions by 50% (ID50) was 25 and 36 mg/kg, respectively, and this protective effect was similar to that obtained with methyl PGE2 analog (5 μg/kg i g). GSE significantly raised the GBF, mucosal generation of PGE2, SOD activity and plasma gastrin levels while attenuating IVlDA content. Inhibition of PGE2 generation with indomethacin or rofecoxib and suppression of NO synthase by L-NNA or capsaicin denervation reversed the GSE-induced protection and the accompanying hyperemia. Cotreatment of exogenous calcitonine gene-related peptide (CGRP) with GSE restored the protection and accompanying hyperemic effects of GSE in rats with capsaicin denervation. CONCLUSION: GSE exerts a potent gastroprotective activity against ethanol and WRS-induced gastric lesions via an increase in endogenous PG generation, suppression of lipid peroxidation and hyperemia possibly mediated by NO and CGRP released from sensory nerves.展开更多
The overall survival for patients with advanced hepatocellular carcinoma(HCC)is still limited.Although the multi-kinase inhibitor sorafenib has recently been approved for this disease,response rates are still low and ...The overall survival for patients with advanced hepatocellular carcinoma(HCC)is still limited.Although the multi-kinase inhibitor sorafenib has recently been approved for this disease,response rates are still low and patients often face dose-limiting toxicities which lead to a reduction in prognosis and treatment success.We here report a patient with metastasized HCC who shows a sustained response for more than 30 mo to sorafenib therapy after failure of a first line therapy with gemcitabine,oxaliplatin and bevacizumab.展开更多
文摘AIM:To evaluate the ability of endoscopic ultrasound(EUS) elastography to distinguish benign from malignant pancreatic masses and lymph nodes.METHODS:A multicenter study was conducted and included 222 patients who underwent EUS examination with assessment of a pancreatic mass(n=121) or lymph node(n=101).The classification as benign or malignant,based on the real time elastography pattern,was compared with the classif ication based on the B-mode EUS images and with the fi nal diagnosis obtained by EUS-guided fi ne needle aspiration(EUS-FNA) and/or by surgical pathology.An interobserver study was performed.RESULTS:The sensitivity and specificity of EUS elastography to differentiate benign from malignant pancreatic lesions are 92.3% and 80.0%,respectively,compared to 92.3% and 68.9%,respectively,for the conventional B-mode images.The sensitivity and specificity of EUS elastography to differentiate benign from malignant lymph nodes was 91.8% and 82.5%,respectively,compared to 78.6% and 50.0%,respectively,for the B-mode images.The kappa coefficient was 0.785 for the pancreatic masses and 0.657 for the lymph nodes.CONCLUSION:EUS elastography is superior compared to conventional B-mode imaging and appears to be able to distinguish benign from malignant pancreatic masses and lymph nodes with a high sensitivity,specificity and accuracy.It might be reserved as a second line examination to help characterise pancreatic masses after negative EUS-FNA and might increase the yield of EUS-FNA for lymph nodes.
基金Supported by Grants from the Interdisciplinary Center for Clinical Research(IZKF,Project B39)the Johannes and Frieda Marohn Foundation of the University of Erlangen-Nuremberg,Germany
文摘AIM: To study the role of advanced glycation end products (AGE) and their specific receptor (RAGE) in the pathogenesis of liver fibrogenesis. METHODS: In vitro RAGE expression and extracellular matrix-related gene expression in both rat and human hepatic stellate cells (HSC) were measured after stimulation with the two RAGE ligands, advanced glycation end product-bovine serum albumin (AGE- BSA) and N'-(carboxymethyl) lysine (CML)-BSA, or with tumor necrosis factor-α (TNF-α). In vivo RAGE expression was examined in models of hepatic fibrosis induced by bile duct ligation or thioacetamide. The effects of AGE-BSA and CML-BSA on HSC proliferation, signal transduction and profibrogenic gene expression were studied in vitro. RESULTS: In hepatic fibrosis, RAGE expression was enhanced in activated HSC, and also in endothelial cells, inflammatory cells and activated bile duct epithelia. HSC expressed RAGE which was upregulated after stimulation with AGE-BSA, CML-BSA, and TNF-α.RAGE stimulation with AGE-BSA and CML-BSA did not alter HSC proliferation, apoptosis, fibrogenic signal transduction and fibrosis- or fibrolysis-related gene expression, except for marginal upregulation of procollagen α1( I ) mRNA by AGE-BSA. CONCLUSION: Despite upregulation of RAGE in activated HSC, RAGE stimulation by AGE does not alter their fibrogenic activation. Therefore, RAGE does not contribute directly to hepatic fibrogenesis.
文摘MM: Persistent cholestasis is a rare complication of severe trauma or infections. Little is known about the possible pathomechanisms and the clinical course.METHODS: Secondary sclerosing cholangitis was diagnosed in five patients with persistent jaundice after severe trauma (one burn injury, three accidents, one power current injury). Medical charts were retrospectively reviewed with regard to possible trigger mechanisms for cholestasis, and the clinical course was recorded.RESULTS: Diagnosis of secondary sclerosing cholangitis was based in all patients on the primary sclerosing cholangitis (PSC)-Iike destruction of the intrahepatic bile ducts at cholangiography after exclusion of PSC. In four patients, arterial hypotension with subsequent ischemia may have caused the bile duct damage, whereas in the case of power current injury direct thermal damage was assumed to be the trigger mechanism. The course of secondary liver fibrosis was rapidly progressive and proceeded to liver cirrhosis in all four patients with a follow-up 〉2 years. Therapeutic possibilities were limited.CONCLUSION: Posttraumatic sderosing cholangitis is a rare but rapidly progressive disease, probably caused by ischemia of the intrahepatic bile ducts via the peribiliary capillary plexus due to arterial hypotension.Gastroenterologists should be aware of this disease in patients with persistent cholestasis after severe trauma.
文摘The current World Health Organization classification system of primary brain tumors is solely based on morphologic criteria. However, there is accumulating evidence that tumors with similar histology have distinct molecular signatures that significantly impact treatment response and survival. Recent practice-changing clinical trials have defined a role for routine assessment of O-6-methylguanine-DNA methyltransferase(MGMT) promoter methylation in glioblastoma patients, especially in the elderly, and 1p and 19q codeletions in patients with anaplastic glial tumors. Recently discovered molecular alterations including mutations in IDH-1/2, epidermal growth factor receptor(EGFR), and BRAF also have the potential to become targets for future drug development. This article aims to summarize current knowledge on the molecular biology of high-grade gliomas relevant to daily practice.
文摘Causality assessment of suspected drug induced liver injury(DILI) and herb induced liver injury(HILI) is hampered by the lack of a standardized approach to be used by attending physicians and at various subsequent evaluating levels. The aim of this review was to analyze the suitability of the liver specific Council for International Organizations of Medical Sciences(CIOMS) scale as a standard tool for causality assessment in DILI and HILI cases. PubMed database was searched for the following terms: drug induced liver injury; herb induced liver injury; DILI causality assessment; and HILI causality assessment. The strength of the CIOMS lies in its potential as a standardized scale for DILI and HILI causality assessment. Other advantages include its liver specificity and its validation for hepatotoxicity with excellent sensitivity, specificity and predictive validity, based on cases with a positive reexposure test. This scale allows prospective collection of all relevant data required for a valid causality assessment. It does not require expert knowledge in hepatotoxicity and its results may subsequently be refined. Weaknesses of the CIOMS scale include the limited exclusion of alternative causes and qualitatively graded risk factors. In conclusion, CIOMS appears to be suitable as a standard scale for attending physicians, regulatory agencies, expert panels and other scientists to provide a standardized, reproducible causality assessment in suspected DILI and HILI cases, applicable primarily at all assessing levels involved. 2014 Baishideng Publishing Group Co., Limited. All
文摘The diagnosis of herbal hepatotoxicity or herb induced liver injury(HILI) represents a particular clinical and regulatory challenge with major pitfalls for the causality evaluation.At the day HILI is suspected in a patient,physicians should start assessing the quality of the used herbal product,optimizing the clinical data for completeness,and applying the Council for International Organizations of Medical Sciences(CIOMS) scale for initial causality assessment.This scale is structured,quantitative,liver specific,and validated for hepatotoxicity cases.Its items provide individual scores,which together yield causality levels of highly probable,probable,possible,unlikely,and excluded.After completion by additional information including raw data,this scale with all items should be reported to regulatory agencies and manufacturers for further evaluation.The CIOMS scale is preferred as tool for assessing causality in hepatotoxicity cases,compared to numerous other causality assessment methods,which are inferior on various grounds.Among these disputed methods are the Maria and Victorino scale,an insufficiently qualified,shortened version of the CIOMS scale,as well as various liver unspecific methods such as thead hoc causality approach,the Naranjo scale,the World Health Organization(WHO) method,and the Karch and Lasagna method.An expert panel is required for the Drug Induced Liver Injury Network method,the WHO method,and other approaches based on expert opinion,which provide retrospective analyses with a long delay and thereby prevent a timely assessment of the illness in question by the physician.In conclusion,HILI causality assessment is challenging and is best achieved by the liver specific CIOMS scale,avoiding pitfalls commonly observed with other approaches.
文摘AIM:To analyze the pathogenetic role and potential clinical usefulness of the epidermal growth factor receptor(EGFR)and the human epidermal growth factor receptor 2(HER2)in patients with advanced biliary tract cancer(BTC). METHODS:EGFR and HER2 expression was studied in biopsy samples from 124 patients(51%women; median age 64.8 years),with advanced BTC diagnosed between 1997 and 2004.Five micrometers sections of paraffin embedded tissue were examined by standard, FDA approved immunohistochemistry.Tumors with scores of 2+or 3+for HER2 expression on immunochemistry were additionally tested for HER2 gene amplification by fluorescence in situ hybridisation(FISH).RESULTS:34/124 patients(27.4%)had gallbladder cancer,47(37.9%)had intrahepatic BTC and 43(34.7%)had extrahepatic or perihilar BTC.EGFR expression was examined in a subset of 56 samples. EGFR expression was absent in 22/56 tumors(39.3%). Of the remaining samples expression was scored as 1+in 12(21.5%),2+in 13(23.2%)and 3+in 9(16%), respectively.HER2 expression was as follows:score 0 73/124(58.8%),score 1+27/124(21.8%),score 2+ 21/124(17%)and score 3+4/124(3.2%).HER2 gene amplification was present in 6/124,resulting in an overall amplification rate of 5%. CONCLUSION:Our data suggest that routine testing and therapeutic targeting of HER2 does not seem to be useful in patients with BTC,while targeting EGFR may be promising.
文摘AIM: To analyze the validity of applied test criteria and causality assessment methods in assumed Herbalife hepatotoxicity with positive reexposure tests. METHODS: We searched the Medline database for suspected cases of Herbalife hepatotoxicity and retrieved 53 cases including eight cases with a positive unintentional reexposure and a high causality level for Herbalife. First, analysis of these eight cases focused on the data quality of the positive reexposure cases, requiring a baseline value of alanine aminotransferase(ALT) < 5 upper limit of normal (N) before reexposure, with Nas the upper limit of normal, and a doubling of the ALT value at reexposure as compared to the ALT value at baseline prior to reexposure. Second, reported methods to assess causality in the eight cases were evaluated, and then the liver specific Council for International Organizations of Medical Sciences (CIOMS) scale validated for hepatotoxicity cases was used for quantitative causality reevaluation. This scale consists of various specific elements with scores provided through the respective case data, and the sum of the scores yields a causality grading for each individual case of initially suspected hepatotoxicity. RESULTS: Details of positive reexposure test conditions and their individual results were scattered in virtually all cases, since reexposures were unintentional and allowed only retrospective rather than prospective assessments. In 1/8 cases, criteria for a positive reexposure were fulfilled, whereas in the remaining cases the reexposure test was classified as negative (n = 1), or the data were considered as uninterpretable due to missing information to comply adequately with the criteria (n = 6). In virtually all assessed cases, liver unspecific causality assessment methods were applied rather than a liver specific method such as the CIOMS scale. Using this scale, causality gradings for Herbalife in these eight cases were probable (n = 1), unlikely (n = 4), and excluded (n = 3). Confounding variables in- cluded low data quality, alternative diagnoses, poor exclusion of important other causes, and comedication by drugs and herbs in 6/8 cases. More specifically, problems were evident in some cases regarding temporal association, daily doses, exact start and end dates of product use, actual data of laboratory parameters such as ALT, and exact dechallenge characteristics. Short-comings included scattered exclusion of hepatitis A-C, cytomegalovirus and Epstein Barr virus infection with only globally presented or lacking parameters. Hepatitis Evirus infection was considered in one single patient and found positive, infections by herpes simplexvirus and varicella zoster virus were excluded in none. CONCLUSION: Only one case fulfilled positive reexposure test criteria in initially assumed Herbalife hepatotoxicity, with lower CIOMS based causality gradings for the other cases than hitherto proposed.
文摘AIM: This study evaluated colorectal mucosal histamine release in response to blinded food challenge-positive and-negative food antigens as a new diagnostic procedure. METHODS: 19 patients suffering from gastrointestinally mediated allergy confirmed by blinded oral provocation were investigated on grounds of their case history, skin prick tests, serum IgE detection and colorectal mucosal histamine release by ex vivo mucosa oxygenation. Intact tissue particles were incubated/stimulated in an oxygenated culture with different food antigens for 30 min. Specimens challenged with anti-human immunoglobulin E and without any stimulus served as positive and negative controls, respectively. Mucosal histamine release (% of total biopsy histamine content) was considered successful (positive), when the rate of histamine release from biopsies in response to antigens reached more than twice that of the spontaneous release. Histamine measurement was performed by radioimmunoassay. RESULTS: The median (range) of spontaneous histamine release from colorectal mucosa was found to be 3.2 (0.1%-25.8%) of the total biopsy histamine content. Food antigens tolerated by oral provocation did not elicit mast cell degranulation 3.4 (0.4%-20.7%, P=0.4), while anti-IgE and causative food allergens induced a significant histamine release of 5.4 (1.1%-25.6%, P = 0.04) and 8.1 (1.5%-57.9%, P = 0.008), respectively. 12 of 19 patients (63.1%) showed positive colorectal mucosal histamine release in accordance with the blinded oral challenge responding to the same antigen (s), while the specificity of the functional histamine release to accurately recognise tolerated foodstuffs was found to be 78.6%. In comparison with the outcome of blinded food challenge tests, sensitivity and specificity of history (30.8% and 57.1%), skin tests (47.4% and 78.6%) or antigen-specific serum IgE determinations (57.9% and 50%) were found to be of lower diagnostic accuracy in gastrointestinally mediated allergy. CONCLUSION: Functional testing of the reactivity of colorectal mucosa upon antigenic stimulation in patients with gastrointestinally mediated allergy is of higher diagnostic efficacy.
基金Supported by the Interdisciplinary Center for Clinical Research(IZKF) of the University of Erlangen-Nuernberg, Germany
文摘To evaluate prospectively 4 selected serum fibrosis markers (tenascin, hyaluronan, collagen Ⅵ, TIMP-1) before, during and 12 mo after IFN treatment of children with chronic hepatitis B. METHODS: Forty-seven consecutive patients with chronic hepatitis B (range 4-16 years, mean 8 years) underwent IFN treatment (3 MU tiw for 20 wk). Fibrosis stage and inflammation grade were assessed in a blinded fashion before and 12 mo after end of treatment. Serum fibrosis markers were determined using automated assays.RESULTS: IFN treatment improved histological inflammation but did not change fibrosis in the whole group or in subgroups. Only hyaluronan correlated significantly with histological fibrosis(r = 0.3383, P = 0.022). Basal fibrosis markers did not differ between responders (42.5%) and nonresponders(57.5%). During IFN treatment only serum tenascin decreased significantly in the whole group and in nonresponders. When pretreatment values were compared to values 12 mo after therapy, TIMP-1 increased in all patients and in nonresponders, and hyaluronan decreased in all patients and in responders.CONCLUSION: Tenascin reflects hepatic fibrogenesis and inflammation which decreases during IFN treatment of children with chronic hepatitis B. TIMP-1 correlates with nonresponse and hyaluronan with histological fibrosis.
基金Supported by Munker S,Weng HL were supported by ChineseGerman Cooperation Group project,No.GZ 1263Ding HG was supported by the National Science Fund,No.81672725+1 种基金the Capital Science and Technology Development Fund,No.2014-1-2181Beijing Municipal Administration of Hospitals Clinical Medicine Development of Special Funding,NoZYLX201610
文摘The question whether epithelial-mesenchymal transition (EMT) occurs during liver fibrogenesis is a controversial issue. In vitro studies confirm that hepatocytes or cholangiocytes undergo EMT upon transforming growth factor beta (TGF-beta) stimulation, whereas in vivo experiments based on genetic fate mapping of specific cell populations suggest that EMT does not occur in fibrotic animal models. In this review we present current data supporting or opposing EMT in chronic liver disease and discuss conditions for the occurrence of EMT in patients. Based on the available data and our clinical observations we hypothesize that EMT-like alterations in liver cirrhosis are a side effect of high levels of TGF-beta and other pro-fibrotic mediators rather than a biological process converting functional parenchyma, i.e., hepatocytes, into myofibroblasts at a time when essential liver functions are deteriorating.
基金Supported by The Münchener Medizinische Wochenschrift(MMW)B.Braun-Stiftung(to Reiter FP)the Deutsche Forschungsgemeinschaft(HO 4460/2-1 to Hohenester S and RU 742/6-1 to Rust C)
文摘AIM: To study the interleukin-1(IL-1) pathway as a therapeutic target for liver fibrosis in vitro and in vivo using the ATP-binding cassette transporter b4^(-/-)(Abcb4^(-/-)) mouse model.METHODS: Female and male Abcb4^(-/-) mice from 6 to 13 mo of age were analysed for the degree of cholestasis(liver serum tests), extent of liver fibrosis(hydroxyproline content and Sirius red staining) and tissue-specific activation of signalling pathways such as the IL-1 pathway [quantitative polymerase chain reaction(q PCR)]. For in vivo experiments, murine hepatic stellate cells(HSCs) were isolated via pronasecollagenase perfusion followed by density gradient centrifugation using female mice. Murine HSCs were stimulated with up to 1 ng/m L IL-1β with or without 2.5 μg/m L Anakinra, an IL-1 receptor antagonist, respectively. The proliferation of murine HSCs was assessed via the Brd U assay. The toxicity of Anakinra was evaluated via the fluorescein diacetate hydrolysis(FDH) assay. In vivo 8-wk-old Abcb4^(-/-) mice with an already fully established hepatic phenotype were treated with Anakinra(1 mg/kg body-weight daily intraperitoneally) or vehicle and liver injury and liver fibrosis were evaluated via serum tests, q PCR, hydroxyproline content and Sirius red staining. RESULTS: Liver fibrosis was less pronounced in males than in female Abcb4^(-/-) animals as defined by a lower hydroxyproline content(274 ± 64 μg/g vs 436 ± 80 μg/g liver, respectively; n = 13-15; P < 0.001; MannWhitney U-test) and lower m RNA expression of the profibrogenic tissue inhibitor of metalloproteinase-1(TIMP)(1 ± 0.41 vs 0.66 ± 0.33 fold, respectively; n = 13-15; P < 0.05; Mann-Whitney U-test). Reduced liver fibrosis was associated with significantly lower levels of F4/80 m RNA expression(1 ± 0.28 vs 0.71 ± 0.41 fold, respectively; n = 12-15; P < 0.05; Mann-Whitney U-test) and significantly lower IL-1β m RNA expression levels(1 ± 0.38 vs 0.44 ± 0.26 fold, respectively; n = 13-15; P < 0.001; Mann-Whitney U-test). No gender differences in the serum liver parameters [bilirubin; alanine aminotransferase(ALT); aspartate aminotransferase and alkaline phosphatase(AP)] were found. In vitro, the administration of IL-1β resulted in a significant increase in HSC proliferation [0.94 ± 0.72 arbitrary units(A.U.) in untreated controls, 1.12 ± 0.80 A.U. at an IL-1β concentration of 0.1 ng/m L and 1.18 ± 0.73 A.U. at an IL-1β concentration of 1 ng/m L in samples from n = 6 donor animals; P < 0.001; analyses of variance(ANOVA)]. Proliferation was reduced significantly by the addition of 2.5 μg/m L Anakinra(0.81 ± 0.60 A.U. in untreated controls, 0.92 ± 0.68 A.U. at an IL-1β concentration of 0.1 ng/m L, and 0.91 ± 0.69 A.U. at an IL-1β concentration of 1 ng/m L; in samples from n = 6 donor animals; P < 0.001; ANOVA) suggesting an anti-proliferative effect of this clinically approved IL-1 receptor antagonist. The FDH assay showed this dose to be non-toxic in HSCs. In vivo, Anakinra had no effect on the hepatic hydroxyprolinecontent, liver serum tests(ALT and AP) and profibrotic(collagen 1α1, collagen 1α2, transforming growth factor-β, and TIMP-1) and anti-fibrotic [matrix metalloproteinase 2(MMP2), MMP9 and MMP13 ] gene expression after 4 wk of treatment. Furthermore, the hepatic IL-1β and F4/80 m RNA expression levels were unaffected by Anakinra treatment.CONCLUSION: IL-1β expression is associated with the degree of liver fibrosis in Abcb4^(-/-) mice and promotes HSC proliferation. IL-1 antagonism shows antifibrotic effects in vitro but not in Abcb4^(-/-) mice.
文摘Chronic intestinal failure(CIF)is a rare but feared complication of Crohn’s disease.Depending on the remaining length of the small intestine,the affected intestinal segment,and the residual bowel function,CIF can result in a wide spectrum of symptoms,from single micronutrient malabsorption to complete intestinal failure.Management of CIF has improved significantly in recent years.Advances in home-based parenteral nutrition,in particular,have translated into increased survival and improved quality of life.Nevertheless,60%of patients are permanently reliant on parenteral nutrition.Encouraging results with new drugs such as teduglutide have added a new dimension to CIF therapy.The outcomes of patients with CIF could be greatly improved by more effective prevention,understanding,and treatment.In complex cases,the care of patients with CIF requires a multidisciplinary approach involving not only physicians but also dietitians and nurses to provide optimal intestinal rehabilitation,nutritional support,and an improved quality of life.Here,we summarize current literature on CIF and short bowel syndrome,encompassing epidemiology,pathophysiology,and advances in surgical and medical management,and elucidate advances in the understanding and therapy of CIF-related complications such as catheter-related bloodstream infections and intestinal failure-associated liver disease.
文摘AIM: Grapefruit-seed extract (GSE) containing flavonoids, possesses antibacterial and antioxidative properties but whether it influences the gastric defense mechanism and gastroprotection against ethanol- and stress-induced gastric lesions remains unknown. METHODS: We compared the effects of GSE on gastric mucosal lesions induced in rats by topical application of 100% ethanol or 3.5 h of water immersion and restraint stress (WRS) with or without (A) inhibition of cyclooxygenase (COX)-1 activity by indomethacin and rofecoxib, the selective COX-2 inhibitor, (B) suppression of NO-synthase with L-NNA (20 mg/kg ip), and (C) inactivation by capsaicin (125 mg/kg sc) of sensory nerves with or without intragastric (ig) pretreatment with GSE applied 30 min prior to ethanol or WRS. One hour after ethanol and 3.5 h after the end of WRS, the number and area of gastric lesions were measured by planimetry, the gastric blood flow (GBF) was assessed by H2-gas clearance technique and plasma gastrin levels and the gastric mucosal generation of PGE2, superoxide dismutase (SOD) activity and malonyldialdehyde (MDA) concentration, as an index of lipid peroxidation were determined. RESULTS: Ethanol and WRS caused gastric lesions accompanied by the significant fall in the GBF and SOD activity and the rise in the mucosal MDA content. Pretreatment with GSE (8-64 mg/kg i g) dose- dependently attenuated gastric lesions induced by 100% ethanol and WRS; the dose reducing these lesions by 50% (ID50) was 25 and 36 mg/kg, respectively, and this protective effect was similar to that obtained with methyl PGE2 analog (5 μg/kg i g). GSE significantly raised the GBF, mucosal generation of PGE2, SOD activity and plasma gastrin levels while attenuating IVlDA content. Inhibition of PGE2 generation with indomethacin or rofecoxib and suppression of NO synthase by L-NNA or capsaicin denervation reversed the GSE-induced protection and the accompanying hyperemia. Cotreatment of exogenous calcitonine gene-related peptide (CGRP) with GSE restored the protection and accompanying hyperemic effects of GSE in rats with capsaicin denervation. CONCLUSION: GSE exerts a potent gastroprotective activity against ethanol and WRS-induced gastric lesions via an increase in endogenous PG generation, suppression of lipid peroxidation and hyperemia possibly mediated by NO and CGRP released from sensory nerves.
文摘The overall survival for patients with advanced hepatocellular carcinoma(HCC)is still limited.Although the multi-kinase inhibitor sorafenib has recently been approved for this disease,response rates are still low and patients often face dose-limiting toxicities which lead to a reduction in prognosis and treatment success.We here report a patient with metastasized HCC who shows a sustained response for more than 30 mo to sorafenib therapy after failure of a first line therapy with gemcitabine,oxaliplatin and bevacizumab.
基金Supported by Grants of the Deutsche Forschungsgemeinschaft(to zur Wiesch JS),No.DFG Grant LU B62/2-1 and No.SFB841 A6the Deutsches Zentrum für Infektionsforschung(to zur Wiesch JS)
文摘AIM: To evaluate the safety and efficacy of pegylated interferon alfa-2a and ribavirin therapy in elderly patients with chronic hepatitis C infection.