33 research outputs found

    Novel scalar boson decays in SUSY with broken r-parity

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    R parity violation can induce mixing of the supersymmetric Higgs bosons with the sneutrinos at the tree level. We study the effect of this mixing on the decays of Higgs scalars as well as sneutrinos in an effective model where the violation of R parity is included in the minimal supersymmetric model through bilinear lepton number violating superpotential terms. We show that a small violation of R parity can lead to a sizeable branching ratio for the supersymmetric Higgs boson decay mode H→χℓ (where χ denotes an electroweak gaugino and ℓ is either a tau neutrino or a tau lepton). Relevant constraints on R parity violation as well as those coming from SUSY particle searches still allow the decay H→χℓ to compete with the conventional decay H\ra b \bar{b}, at least for some ranges of parameters of the model. Moreover, the tau sneutrino will have dominant R parity violating decays to standard model fermions bb¯, τ+τ− or to the invisible mode νν¯ whenever the phase space for R parity conserving channels is closed

    Collider aspects of flavour physics at high Q

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    This review presents flavour related issues in the production and decays of heavy states at LHC, both from the experimental side and from the theoretical side. We review top quark physics and discuss flavour aspects of several extensions of the Standard Model, such as supersymmetry, little Higgs model or models with extra dimensions. This includes discovery aspects as well as measurement of several properties of these heavy states. We also present public available computational tools related to this topic.Comment: Report of Working Group 1 of the CERN Workshop ``Flavour in the era of the LHC'', Geneva, Switzerland, November 2005 -- March 200

    Is it time to reconsider the BCLC/AASLD therapeutic flow-chart?

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    PURPOSE: Recommendations of the Barcelona Clinic Liver Cancer (BCLC) therapeutic flow-chart, endorsed by the American Association for the Study of Liver Diseases (AASLD), are the most applied worldwide. Over recent years, however, several referral centers have questioned some of the BCLC treatment allocations and proposed alternative strategies. The present study plans to review and discuss these suggestions, with the aim to evaluate whether there are well-grounded reasons to reconsider some of the BCLC/AASLD recommendations. METHODS: A search was made into the MEDLINE database, focusing on randomized controlled trials, meta-analysis reviews, case-control studies, concordant clinical trials on novel therapies and studies reporting the opinion of respected experts. Their results and conclusions were compared stage by stage with BCLC/AASLD recommendations. RESULTS: In stage 0 (very early, or single <2 \u2009cm, or carcinoma in situ, Child A) radiofrequency should replace resection. In stage A (early, or single or three nodules up to 3\u2009 cm, Child A-B) radiofrequency and resection should expand their indications. In stage B (intermediate, or multinodular, Child A-B) resection and transplantation should expand their indications, while intra-arterial therapies are changing from conventional to selective treatments. In stage C (advanced, portal invasion or extrahepatic disease, Child A-B) systemic therapies should offer previously unknown promising options. CONCLUSION: In our opinion, so much evidence leads to suggest it is time to reconsider several BCLC/AASLD recommendations. Some treatments are comparable in results but vary in costs, local availability, or complication rates

    Temporal and tissue-specific expression of the MET ORF driven by the complete transcriptional unit of human A1AT gene in transgenic mice

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    We inserted the sequence coding for the cytoplasmic portion of the human MET receptor into an 18-kb genomic fragment containing the entire human A1AT gene (encoding alpha-1-antitrypsin). Stringent control of gene expression, at the transcriptional, post-transcriptional and translational levels, was ensured by insertion of the MET open reading frame into A1AT, thus maintaining: (i) all the elements that confer tissue-specific transcription initiation, (ii) all the sequences involved in transcript processing and (iii) all the sequences which influence messenger stability and translational efficiency. The expression pattern of this vector in transgenic mice was identical to that of the human A1AT transgene, as well as to that of A1AT in humans with regard to both temporal and tissue-specific regulation

    Observation of thoracic duct morphology in portal hypertension by endoscopic ultrasound

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    Thoracic duct dilation has been demonstrated in portal hypertension and hepatic cirrhosis by lymphangiography and laparotomy and at autopsy. It is thought to be secondary to increased hepatic lymph flow and has been described in the absence of ascites or esophageal varices. The aim of the present study was to observe thoracic duct morphology by endoscopic ultrasound in various subsets of patients with portal hypertension and hepatic cirrhosis and also to validate existing radiologic/surgical data. METHODS: The thoracic duct of 33 patients with cirrhosis and portal hypertension was studied by endoscopic ultrasound. Patients were divided into four groups: 1, patients with ascites and esophageal varices; 2, esophageal varices without ascites; 3, without esophageal varices or ascites; 4, extrahepatic portal hypertension due to pancreatic malignancy. The thoracic duct diameter was also measured in 14 control subjects (group 5). RESULTS: When the thoracic duct diameter for the five groups was compared with analysis of variance, significance was p < 0.0001; by pairwise comparison, group 1 differed from the other four groups (p < 0.05). Thoracic duct dilation (5.61 mm) was seen in group 1 patients, whereas no dilation was present in groups 2 through 4. Additionally, thoracic duct diameter in 33 portal hypertensive and/or cirrhotic patients was significantly different from that in the 14 control subjects (p = 0. 003). CONCLUSION: The thoracic duct can be reliably identified by EUS in patients with hepatic cirrhosis and portal hypertension. Dilation of the duct is seen only in patients with hepatic cirrhosis, ascites, and esophageal varices. No thoracic duct dilation is present in extrahepatic portal hypertension. Contrary to existing radiologic/surgical data, thoracic duct dilation is not seen in all patients with hepatic cirrhosis and portal hypertension signifying advanced disease. A dilated thoracic duct by endoscopic ultrasound should be considered yet another sign of portal hypertension

    Prediction of asymptomatic cirrhosis in chronic hepatitis C patients : accuracy of artificial neural networks compared with logistic regression models

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    OBJECTIVE: Models based on logistic regression analysis are proposed as noninvasive tools to predict cirrhosis in chronic hepatitis C (CHC) patients. However, none showed to be sufficiently accurate to replace liver biopsy. Artificial neural networks (ANNs), providing a prediction based on nonlinear algorithms, can improve the diagnosis of cirrhosis, a syndrome characterized by complex, nonlinear biological alterations. We compared ANNs with two logistic regression analysis-based models in predicting CHC histologically proven cirrhosis. METHODS: Liver biopsy was obtained in CHC patients of two different cohorts (an internal cohort including 244 patients and an external cohort including 220 patients). One hundred and forty-four patients from the internal cohort served as a training set to construct ANNs and a logistic regression model (LOGIT). These two models and the aspartate aminotransferase-to-platelet ratio index (APRI) were tested in the remaining 100 patients (internal validation set) and in the external cohort (external validation set). Diagnostic performances were evaluated by standard indices of accuracy. RESULTS: In the internal validation set, ANNs, LOGIT, and APRI showed similar discrimination powers (0.88, 0.87, and 0.87 respectively). However, ANNs showed the best positive predictive value (0.86 vs. 0.67 and 0.56) and positive likelihood ratio (40.2 vs. 13.4 and 8.4). In the external validation set, the discrimination power of ANNs (0.76) was significantly higher than those of LOGIT (0.67) and APRI (0.67). CONCLUSION: Compared to conventional models, ANNs performance in predicting CHC cirrhosis is slightly better and more reproducible

    Determination of CA 19-9 antigen in serum and pancreatic juice for differential diagnosis of pancreatic adenocarcinoma from chronic pancreatitis

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    Serum CA 19-9 levels were measured in 63 patients with ductal pancreatic adenocarcinoma and in 49 patients with chronic pancreatitis. Concentrations were abnormally high (greater than 40 U/ml) in 57 (90%) patients with cancer and only in 5 (10%) patients with chronic pancreatitis. All patients with falsely normal serum values had poorly differentiated carcinomas. Median CA 19-9 concentrations were progressively higher in patients with more advanced cancer. Fifteen of 16 (93%) patients with localized cancer has abnormal serum levels but only 5 (31%) of them had values greater than 120 U/ml, which was the highest score observed in patients with chronic pancreatitis. Pure pancreatic juice was obtained endoscopically from 23 patients with pancreatic cancer and from 20 with chronic pancreatitis. CA 19-9 concentrations in pancreatic juice were significantly higher in patients with cancer than in non-neoplastic patients. All 11 patients with resectable cancer investigated had a ratio of CA 19-9 to secretory protein concentration in pancreatic juice above the range of patients with chronic pancreatitis. We conclude that serum CA 19-9 determination is highly sensitive and specific for the differential diagnosis of pancreatic cancer versus chronic pancreatitis. However, moderately increased values (less than 120 U/ml), as seen in patients with localized pancreatic adenocarcinoma, are not conclusive for malignancy. The measurement of CA 19-9 to total protein ratio in pure pancreatic juice is proposed as an adjunctive, accurate diagnostic marker for early stages of pancreatic adenocarcinoma

    Association between heterozygosity for HFE gene mutations and hepatis viruses in hepatocellular carcinoma

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    Hepatitis B virus (HBV) and hepatitis C virus (HCV) infections are strong and independent risk factors for hepatocellular carcinoma (HCC) development. Patients with hereditary hemochromatosis (HH) are considered at risk of developing cancer. However, the interaction between HFE gene mutations and hepatitis viruses for HCC development has not been systematically searched for. To assess the interaction between HFE gene mutations and exogenous risk factors in the risk of HCC occurrence, a case-only approach, in which just a series of patients is enrolled, was used. Three hundred three cirrhotic patients (231 males, 72 females) from five liver units in different geographic areas of Italy, who developed HCC during regular follow-up between January 1999 and March 2003, and whose blood DNA was available, were analyzed. In all subjects, hepatitis B surface antigen (HBsAg), anti-HCV and HFE gene mutations were assayed; alcohol intake was recorded by history. The interaction between HFE genotypes and hepatitis viruses for HCC was estimated by multivariate analysis adjusting for the confounding effect of alcohol intake, area of residence and months of follow-up. Of the 303 HCC cases, 12 (4.0%) were heterozygous for the C282Y mutation, 93 (30.7%) for the H63D, and 198 (65.3%) homozygous for the wild allele. Multivariate analysis showed that C282Y heterozygous males were 3.8-fold (95% CI=1.0-15.2) more likely to be HBV positive and that H63D heterozygous females were 6.0-fold (95% CI=1.2-113.8) more likely to be HCV positive than wild type subjects. In conclusion, given the association between C282Y mutation and HBV infection in male patients with HCC, a careful evaluation and follow-up should be considered in the C282Y-positive subjects with hepatitis B virus related liver disease. The interaction between the H63D mutation and HCV, observed only in women, may reflect a higher sensitivity to H63D-induced iron metabolism abnormalities and a reduced antioxidant capability in the presence of an even minor increase of iron which may occur as a consequence of the coexistence of hepatitis C infection and heterozygosity for H
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