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Orit Pappo

Publications and source records attributed to Orit Pappo.

At least 37 records · Page 2Linked to original sources
PubMed2005

Treatment of chronic hepatitis C virus infection via antioxidants: results of a phase I clinical trial.

BACKGROUND: The pathogenesis of chronic hepatitis C virus (HCV) infection is associated with a defective host antiviral immune response and intrahepatic oxidative stress. Oxidative stress and lipid peroxidation play major roles in the fatty liver accumulation (steatosis) that leads to necro-inflammation and necrosis of hepatic cells. Previous trials suggested that antioxidative therapy may have a beneficial effect on patients with chronic HCV infection. AIMS: To determine the safety and efficacy of treatment of chronic HCV patients via a combination of antioxidants. METHODS: Fifty chronic HCV patients were treated orally on a daily basis for 20 weeks with seven antioxidative oral preparations (glycyrrhizin, schisandra, silymarin, ascorbic acid, lipoic acid, L-glutathione, and alpha-tocopherol), along with four different intravenous preparations (glycyrrhizin, ascorbic acid, L-glutathione, B-complex) twice weekly for the first 10 weeks, and followed up for an additional 20 weeks. Patients were monitored for HCV-RNA levels, liver enzymes, and liver histology. Assessment of quality of life was performed using the SF-36 questionnaire. RESULTS: In one of the tested parameters (eg, liver enzymes, HCV RNA levels, or liver biopsy score), a combination of antioxidants induced a favorable response in 48% of the patients (24). Normalization of liver enzymes occurred in 44% of patients who had elevated pretreatment ALT levels (15 of 34). ALT levels remained normal throughout follow-up period in 72.7% (8 of 11). A decrease in viral load (one log or more) was observed in 25% of the patients (12). Histologic improvement (2-point reduction in the HAI score) was noted in 36.1% of the patients. The SF-36 score improved in 26 of 45 patients throughout the course of the trial (58% of the patients). Treatment was well tolerated by all patients. No major adverse reactions were noted. CONCLUSIONS: These data suggest that multi antioxidative treatment in chronic HCV patients is well tolerated and may have a beneficial effect on necro-inflammatory variables. A combination of antiviral and antioxidative therapies may enhance the overall response rate of these patients.

Adolescent↗
PubMed2004

Inhibition of hepatic gluconeogenesis and enhanced glucose uptake contribute to the development of hypoglycemia in mice bearing interleukin-1beta- secreting tumor.

Mice bearing IL-1beta-secreting tumor were used to study the chronic effect of IL-1beta on glucose metabolism. Mice were injected with syngeneic tumor cells transduced with the human IL-1beta gene. Serum IL-1beta levels increased exponentially with time. Secretion of IL-1beta from the developed tumors was associated with decreased food consumption, reduced body weight, and reduced blood glucose levels. Body composition analysis revealed that IL-1beta caused a significant loss in fat tissue without affecting lean body mass and water content. Hepatic phosphoenolpyruvate carboxykinase and glucose-6-phosphatase activities and mRNA levels of these enzymes were reduced, and 2-deoxy-glucose uptake by peripheral tissues was enhanced. mRNA levels of glucose transporters (Gluts) in the liver were determined by real-time PCR analysis. Glut-3 mRNA levels were up-regulated by IL-1beta. Glut-1 and Glut-4 mRNA levels in IL-1beta mice were similar to mRNA levels in pair-fed mice bearing nonsecreting tumor. mRNA level of Glut-2, the major Glut of the liver, was down-regulated by IL-1beta. We concluded that both decreased glucose production by the liver and enhanced glucose disposal lead to the development of hypoglycemia in mice bearing IL-1beta-secreting tumor. The observed changes in expression of hepatic Gluts that are not dependent on insulin may contribute to the increased glucose uptake.

Animals↗
PubMed2004

Role of cytokine gene polymorphism and hepatic transforming growth factor beta1 expression in recurrent hepatitis C after liver transplantation.

Recurrent hepatitis C virus (HCV) infection after orthotopic liver transplantation (OLT) is nearly universal. Cytokines play an important role in the immune response to viral infection, and cytokine gene polymorphism affects the overall expression and secretion of cytokines. The objective of this study was to define the relationship between cytokine polymorphism and recurrent hepatitis C after OLT. Blood samples were collected from 36 patients at a mean of 44.6+/-30.4 months after OLT for chronic HCV infection. DNA was extracted from peripheral blood mononuclear cells, and polymerase chain reaction-sequence specific primers (PCR-SSP) analysis was performed on promoter sequences of transforming growth factor beta1 (TGF-beta1), interleukin 6 (IL-6) interleukin 10 (IL-10), tumor necrosis factor alpha (TNF-alpha) and interferon gamma (INF-gamma). Liver biopsies performed at diagnosis of recurrent disease were graded with the Knodell score, and hepatic TGF-beta1 expression was determined semiquantitatively by immunohistochemistry. The gene polymorphism of TGF-beta1 was correlated with its expression on hepatocytes and sinusoids. Polymorphism in all studied cytokine genes was correlated with recurrence, and interval to recurrence (>12 or < or =12 months post-OLT), and clinical (ascites, Child-Pugh score and death), biochemical parameters of recurrent HCV (serum alanine aminotransferase (ALT)), INR, albumin, bilirubin), and virological parameters (HCV genotype and load). Biopsies revealed recurrent HCV in 31 patients (86.1%); in 21 (67.7%), the interval to recurrence was 12 months. There was a statistically significant correlation between TGF-beta1 gene polymorphism, i.e., the genetic ability to produce high levels of TGF-beta1, and the intensity of TGF-beta1 staining on hepatocytes (p=0.003) and sinusoids (p=0.003), and the degree of fibrosis (p=0.02). A borderline correlation was found with the presence of ascites (p=0.007), but not with Child-Pugh score, synthetic liver function tests or HCV genotype and load. The genetic ability to produce low levels of IFN-gamma was correlated with recurrent disease (p=0.015). No such correlation was found for TGF-beta1 gene polymorphism. In conclusion, polymorphism in the TGF-beta1 gene correlates with its in situ hepatic expression in patients with recurrent HCV after liver transplantation. INF-gamma, but not TGF-beta1 gene polymorphism, correlates with early recurrent hepatitis C after transplantation. These findings might help to design preemptive prevention therapy in selected patients at risk.

Cohort Studies↗
PubMed2004

A pivotal role of cyclic AMP-responsive element binding protein in tumor progression.

Tumor microenvironment controls the selection of malignant cells capable of surviving in stressful and hypoxic conditions. The transcription factor, cyclic AMP-responsive element binding (CREB) protein, activated by multiple extracellular signals, modulates cellular response by regulating the expression of a multitude of genes. Previously, we have demonstrated that two cystein residues, at the DNA binding domain of CREB, mediate activation of CREB-dependent gene expression at normoxia and hypoxia. The construction of a dominant-positive CREB mutant, insensitive to hypoxia cue (substitution of two cystein residues at position 300 and 310 with serine in the DNA binding domain) and of a dominant negative CREB mutant (addition of a mutation in serine(133)), enabled a direct assessment, in vitro and in vivo, of the role of CREB in tumor progression. In this work, we demonstrate both in vitro and in vivo that CREB controls hepatocellular carcinoma growth, supports angiogenesis, and renders resistance to apoptosis. Along with the identification, by DNA microarray, of the CREB-regulated genes in normoxia and hypoxia, this work demonstrates for the first time that in parallel to other hypoxia responsive mechanisms, CREB plays an important role in hepatocellular carcinoma tumor progression.

Amino Acid Sequence↗
PubMed2004

Involvement of the CXCL12/CXCR4 pathway in the advanced liver disease that is associated with hepatitis C virus or hepatitis B virus.

Chronic hepatitis C virus (HCV) and hepatitis B virus (HBV) infection is accompanied by inflammation and fibrosis eventually leading to cirrhosis. The chemokine CXCL12 is involved in chronic inflammatory conditions. The role of the CXCL12/CXCR4 pathway in HCV- and HBV-associated liver inflammation and fibrosis was therefore studied. The levels and tissue localization of CXCL12 in liver and plasma of HCV and HBV patients were tested using immunohistochemistry and ELISA. The expression and function of CXCR4 on liver-infiltrating lymphocytes (LIL) were tested by FACS and transwell migration assays. We found that CXCL12 is expressed by bile duct epithelial cells in normal liver tissue. Bile duct proliferation and liver fibrosis in chronic HCV and HBV infection result in the anatomical re-distribution of CXCL12 in the liver. Moreover, CXCL12 is up-regulated in the endothelium of neo-blood-vessels formed in active inflammatory foci and is significantly elevated, compared with controls, in the plasma of patients with advanced liver fibrosis. Complementing these observations were others indicating that over 50% of LIL express CXCR4 and, in response to CXCL12, migrated and adhered to fibronectin. These observations suggest an important role for the CXCL12/CXCR4 pathway in recruitment and retention of immune cells in the liver during chronic HCV and HBV infection.

Cell Adhesion↗
PubMed2004

Heparanase expression during normal liver development and following partial hepatectomy.

Heparan sulphate proteoglycans are major components of the liver extracellular matrix. Their cleavage by heparanase (endo-beta-glucuronidase) may thus be involved in liver-specific normal and pathological processes. Heparanase mRNA and protein were expressed during liver development but not in the mature healthy liver. A biphasic gain of heparanase expression, detected by immunostaining, western blotting, and real-time RT-PCR, was clearly noted following partial hepatectomy, peaking at 12 and 96-168 h and subsiding 2 weeks post-surgery. Expression of heparan sulphate gradually increased throughout the regeneration process. Unlike heparanase, baseline levels of matrix metalloproteinase-2 (MMP-2) were detected in the intact liver, increasing up to 4 days following partial hepatectomy and subsiding at day 10. Bands matching MMP-9 were absent prior to hepatectomy, but visible 2 h post-hepatectomy. Thioacetamide-induced liver fibrosis was associated with increased levels of MMP-9 and MMP-2, correlating with the severity of the disease. Elevated heparanase levels were noted in the early stages of fibrosis, with no further increase evident in rats exhibiting higher fibrotic grades. Taken together, these data suggest a role for heparanase during liver development and remodelling.

Animals↗
PubMed2004

Clinical outcomes of surgical resections for primary liver sarcoma in adults: results from a single centre.

BACKGROUND: Primary hepatic sarcoma is a rare tumour with a poor prognosis. METHODS: From 1997 to 2002 eight patients had liver resection for primary sarcoma of the liver at our institution. The clinical characteristics, imaging findings, surgical procedures, adjuvant therapy and outcome were retrospectively reviewed. There were two patients each with angiosarcoma (AS), leiomyosarcoma (LMS), and undifferentiated embryonal sarcoma (UES), one patient with epithelioid hemangioendothelioma (EHE) and one patient with malignant peripheral nerve sheath sarcoma (PNSS). RESULTS: The most common presenting symptoms were right upper quadrant pain and fever. Typical imaging findings were a heterogenous mass with poorly defined margins, pseudocapsule and aberrant vasculature. Preoperative diagnosis of a primary liver sarcoma was made in 7/8 cases, either by fine needle aspiration (n = 5) or angiography (n = 2). Five right hepatectomies and three trisegmentectomies were performed. An R (0) resection was possible in three cases. Two patients developed complications and there was one death. Adjuvant chemoradiotherapy was administered to 5/7 patients. Systemic chemotherapy led to tumour regression in both patients with UES which enabled a second hepatic resection. CONCLUSIONS: The majority of patients with primary liver sarcoma present with right upper quadrant pain, fever and a liver mass. Differentiating the rare primary liver sarcoma from the much more common hepatocellular carcinoma (HCC) may aid in planning therapy. Patients with resectable tumours should be referred for surgery. Liver resection combined with adjuvant chemotherapy are the mainstays of treatment for UES in the adult.

Adult↗
PubMed2004

Prevention of fibrosis in experimental colitis by captopril: the role of tgf-beta1.

BACKGROUND & AIMS: There is a body of evidence to suggest that the local activation of angiotensin II (ANG II) plays a pivotal role in fibrogenic response involving the kidney, heart, lung, pancreas and liver. In such conditions, fibrosis is mediated, at least partially, through ANG II induction of the cytokine transforming growth factor-beta1 (TGF-beta1). Both ANG II and TGF-beta1 also seem to be involved in intestinal fibrosis and stenosis, particularly in Crohn's disease. The aim of the present study was, firstly, to determine the effects of the angiotensin-converting enzyme inhibitor, captopril, on colonic fibrosis in experimental colitis in rats and, secondly, to check the role of TGF-beta1 on these effects. METHODS: Colitis was induced in rats by intracolonic administration of TNBS. Colonic fibrosis was assessed 21 days later by macroscopic and microscopic evaluation. Levels of collagen alpha1 gene expression, hydroxyproline, angiotensin II and TGF-beta1 proteins, and TGF-beta1 mRNA were measured on the colonic tissue. RESULTS: In chronic colitis, captopril significantly reduced the score of macroscopic and histologic lesions, as well as the colonic tissue levels of collagen alpha1, hydroxyproline, ANG II and TGF-beta1 proteins, and TGF-beta1 mRNA. CONCLUSIONS: These data demonstrate for the first time that the prophylactic administration of captopril is effective in preventing colonic fibrosis in TNBS-induced colitis. The antifibrotic action of captopril could be due to the blockade of TGFbeta-1 overexpression, and/or to a direct down-regulation of TGFbeta-1 transcript.

Angiotensin-Converting Enzyme Inhibitors↗
PubMed2004

Induction of oral immune regulation towards liver-extracted proteins for treatment of chronic HBV and HCV hepatitis: results of a phase I clinical trial.

BACKGROUND: Anti-viral immunity can be modulated via oral feeding of viral proteins. Hepatitis B and C viral (HBV, HCV)-associated hepatocellular injury is mediated by a defective host anti-viral immune response. AIMS: To determine the effect of oral administration of a mixture of liver-extracted proteins with HBV/HCV proteins, on viral load, liver injury, and the anti-viral T-cell response of chronic HBV/HCV patients. METHODS: Fourteen patients with chronic HBV and 15 patients with chronic HCV were treated orally with hepatocyte-extracted proteins and HBV or HCV viral proteins for 24 weeks, and followed for an additional 26 weeks. Patients were monitored for HBV-DNA or HCV-RNA levels, liver enzymes and liver histology. Viral-directed T-cell immunity was assessed by IFNgamma and IL10 ELISPOT, viral-specific T-cell proliferation, cytotoxicity, and cytokines assays, and followed for peripheral natural killer T-cell (NKT) number. RESULTS: In both chronic HBV and HCV patients, oral administration of a mixture of selected liver-extracted proteins and viral proteins induced a favorable increase in viral-specific T-cell proliferation, and IFNgamma-secreting clones, along with a significant decrease in the anti-viral IL10-secreting T-cell clones. However, the effects of modulation of the anti-viral immunity differed between the HBV and HCV patients. In both groups, no major adverse events were noted. In chronic HBV patients, a significant decrease in viral load was observed in 5/14 (35.7%) of patients. HB surface antigen/HB nucleocapsid antigen scores on liver biopsy improved in 46.1% and 50%, respectively, and the histological necroinflammatory score improved in 4/13 (30.7%). Forty percent of the patients with elevated liver enzymes showed a favorable biochemical response. In contrast, an improvement in the histological necroinflammatory score was observed in only 2/12 (17%) of the chronic HCV patients. No significant decrease in HCV RNA was noted in any of these patients. CONCLUSIONS: Immune regulation of the anti-HBV/HCV immune response via oral administration of a mixture of liver-extracted and viral proteins significantly altered the viral-specific immunity. This effect was associated with clinical and virological improvements in chronic HBV patients.

Administration, Oral↗
PubMed2003

Femtosecond infrared laser-an efficient and safe in vivo gene delivery system for prolonged expression.

The major advantages of "naked DNA gene therapy" are its simplicity and a low or negligible immune response. Gene delivery by DNA electroporation (EP) involves injection of DNA and the application of a brief electric pulse to enhance cellular permeability. Although EP is an efficient gene transduction technique in rodents, it requires much higher voltages (>500 V) in larger animals, and hence, in practice it would be hazardous for human patients, as it would cause serious tissue damage. To overcome the obstacles associated with EP-mediated gene delivery in vivo, we developed a new method of gene transduction that uses laser energy. The femtosecond infrared titanium sapphire laser beam was developed specifically for enhancing in vivo gene delivery without risks of tissue damage. System optimization revealed that injection of 10 micro g naked DNA into the tibial muscle of mice followed by application of the laser beam for 5 s, focused to 2 mm depth upon an area of 95 x 95 micro m(2), resulted in the highest intensity and duration of gene expression with no histological or biochemical evidence of muscle damage. We assessed the potential clinical application of LBGT technology by using it to transfer the murine erythropoietin (mEpo) gene into mice. LBGT-mediated mEpo gene delivery resulted in elevated (>22%) hematocrit levels that were sustained for 8 weeks. Gene expression following LBGT was detected for >100 days. Hence, LBGT is a simple, safe, effective, and reproducible method for therapeutic gene delivery with significant clinical potential.

Animals↗
PubMed2003

Intrahepatic cholestasis after liver transplantation.

Cholestasis is a common sequela of liver transplantation. Although the majority of cases remain subclinical, severe cholestasis may be associated with irreversible liver damage, requiring retransplantation. Therefore, it is essential that clinicians be able to identify and treat the syndromes associated with cholestasis. In this review, we consider causes of intrahepatic cholestasis. These may be categorized by time of occurrence, namely, within 6 months of liver transplantation (early) and thereafter (late), although there may be an overlap in their causes. The causes of intrahepatic cholestasis include ischemia/reperfusion injury, bacterial infection, acute cellular rejection, cytomegalovirus infection, small-for-size graft, drugs for hepatotoxicity, intrahepatic biliary strictures, chronic rejection, hepatic artery thrombosis, ABO blood group incompatibility, and recurrent disease. The mechanisms of cholestasis in each category and the clinical presentation, diagnosis, treatment, and outcome are discussed in detail.

Cholestasis, Intrahepatic↗
PubMed2002

Mast cell dynamics and involvement in the development of peritoneal adhesions in the rat.

Mast cells have been implicated in the ethiopathology of post-operative peritoneal adhesions. However an evaluation of their role in this condition is missing. Adhesions were induced in rats using small intestinal scraping. These rats or rats injected ip with either Stem Cell Factor (SCF) or nedocromil sodium or compound 48/80 (day 0-20) were sacrificed for grading of peritoneal adhesions, for evaluating mast cells and inflammatory cells in adhesions and peritoneal lavage (histochemical staining) and for histamine content (peritoneal lavage, radioenzymatic assay) on days 1-21. Mast cell sonicate was added to intestinal fibroblast and their proliferation was assessed (cell counting). All the rats developed adhesions (day 1) and after 3 days the adhesion score remained constant. Early adhesions were avascular and made of fibrinous exudate containing many mast cells. Thereafter adhesions became denser, and the number of stainable mast cells decreased and then stabilized. On the first few days, inflammatory cells in the peritoneal lavage increased while mast cells and histamine content were significantly reduced indicating their activation. Injection of SCF for 1 week slightly increased peritoneal adhesion formation while nedocromil sodium reduced their development. Compound 48/80 had no significant influence. Addition of mast cell sonicate to normal intestine or to peritoneal adhesion fibroblasts resulted in a significant increase of fibroblast proliferation. In conclusion, mast cell presence correlated with the establishment of peritoneal adhesions, and their pharmacological modulation influenced adhesion formation. In vitro mast cell induced fibroplasia. Therefore, mast cells have a profibrogenic role in this model of peritoneal adhesions.

Animals↗
PubMed2002

Pregnancy and delivery in a patient with metastatic embryonal sarcoma of the liver.

BACKGROUND: Embryonal sarcoma of the liver is a rare undifferentiated mesenchymal neoplasm with a grave prognosis. CASE: We report a spontaneous uneventful pregnancy in a young woman with recurrent metastatic embryonal sarcoma of the liver after hepatectomy (twice) and radiochemotherapy. The patient chose to continue pregnancy despite her general condition and possible hazards to maternal and fetal well-being. She gave birth to a full-term healthy infant. Her disease recurred shortly after the delivery. CONCLUSION: According to a computerized search of the National Library of Medicine database, from 1966 to present, using the search terms "embryonal (or undifferentiated) sarcoma" and "liver" without language restrictions, this is the first reported case of pregnancy and delivery in a patient with embryonal sarcoma of the liver. It illustrates the clinical and ethical dilemmas associated with this complicated condition.

Adult↗
PubMed2002

Autoimmune cholangiopathy associated with systemic lupus erythematosus.

We report a 39-year-old female who presented over 11 years with autoimmune cholangiopathy associated with kaleidoscopic manifestations of systemic lupus erythematosus (SLE), including, arthritis, skin changes, pleuritis, diffuse proliferative glomerulonephritis, lymphadenopathy, splenomegaly, hyperglobulinemia, and major depression. While antimitochondrial antibodies (AMA) were absent, antinuclear (ANA) and anti-DNA antibodies were detected in high titres associated with hypocomplementemia. The patient also had vitamin B12 deficiency and antiphospholipid antibodies. The patient required steroids and repeated courses of cyclophosphamide for the management of lupus nephritis, and ursodeoxycholic acid (ursolite) administration resulted in amelioration of cholestatic laboratory abnormalities. This unusual case report and review of literature illustrate that immune liver disease may be an important clinical manifestation of SLE, especially autoimmune cholangiopathy.

Adult↗
PubMed2002

Role of mast cells and myofibroblasts in human peritoneal adhesion formation.

OBJECTIVE: To study fibroblasts and mast cells in human peritoneal adhesions and to evaluate whether their interaction plays a role in adhesion development. SUMMARY BACKGROUND DATA: Myofibroblasts play a critical role in wound repair/fibrosis. Mast cells influence the formation of peritoneal adhesions in a rat model, and they are modulators of fibroblast functions. METHODS: Peritoneal adhesion biopsies were processed for either histology (H&E, toluidine blue) or immunohistochemistry (tryptase, laminin, collagen type IV and VIII, and alpha-SMA) or grown as explants for obtention of fibroblasts. The effects of mast cell (HMC-1) sonicate and selected mast cell mediators and cytokines on fibroblast proliferation ([ (3)H]thymidine) and collagen synthesis ([ (3)H]proline) and on fibroblast contractile activity (tridimensional collagen lattice) were evaluated. Mast cell mediators influencing fibroblast proliferation were partially characterized by enzymatic susceptibility and FPLC gel filtration column chromatography. RESULTS: Most of the fibroblasts in peritoneal adhesions were identified as alpha-SMA-positive myofibroblasts. Mast cell hyperplasia was observed and more than one third of the mast cells were degranulated. Few mast cells showed a faint staining for laminin or collagen type IV and VIII. Mast cell sonicate increased fibroblast proliferation and contractile activity while decreasing collagen synthesis. Mast cell sonicate proliferating activities were found to be proteinase-sensitive with a molecular weight of more than 158 kd, of approximately 40 kd, and of less than 10 kd. TGF-beta and tryptase enhanced collagen synthesis; TNF-alpha and chymase decreased it. None of the selected mediators increased fibroblast proliferation. CONCLUSIONS: Myofibroblasts are the main connective tissue cells present in human peritoneal adhesions, and mast cells play a direct role in peritoneal adhesion formation.

Cell Division↗
PubMed2002

Exacerbation of pulmonary sarcoidosis after liver transplantation.

Patients with hepatic sarcoidosis rarely require orthotopic liver transplantation (OLT). Progression of granulomatous activity involving other organs after OLT has rarely been described. We describe a 32-year-old woman who underwent liver transplantation for sarcoidosis-associated end-stage liver disease. She presented 4 years later with shortness of breath, hilar lymphadenopathy, and interstitial lung abnormalities. Liver functions were normal. Open lung biopsy results revealed granulomata compatible with sarcoidosis. The patient made a complete recovery after corticosteroid treatment. To the best of our knowledge, this is a first description of severe exacerbation of pulmonary sarcoidosis in an immunosuppressed patient who underwent liver transplantation for sarcoidosis-associated liver disease.

Adult↗