117 research outputs found

    Current Algebra of Super WZNW Models

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    We derive the current algebra of supersymmetric principal chiral models with a Wess-Zumino term. At the critical point one obtains two commuting super Kac-Moody algebra as expected, but in general there are intertwining fields connecting both right and left sectors, analogously to the bosonic case. Moreover, in the present supersymmetric extension we have a quadratic algebra, rather than an affine Lie algebra, due to the mixing between bosonic and fermionic fields since the purely fermionic sector displays a Lie algebra as well.Comment: 13 page

    Discriminant analysis on small cell lung cancer and non-small cell lung cancer by means of NSE and CYFRA-21.1

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    A correct diagnosis of small cell lung cancer (SCLC) and non-small cell lung cancer (NSCLC) is essential both for prognostic and therapeutic reasons. We used discriminant analysis as a method to optimize the discriminant power of serum tumour marker levels for differentiation between SCLC and NSCLC. A panel of serum markers, including neurone specific enolase (NSE), cytokeratin fragment antigen 21.1 (CYFRA-21.1), tissue polypeptide antigen (TPA) and carcinoembryonic antigen (CEA) was obtained in 50 consecutive NSCLC and 17 SCLC. Data were analysed by the BMDP statistical program after logarithmic transformation of marker levels. The variables selected were NSE and CYFRA-21.1. Considered together, they were able to give a 97% rate of correct classification. The formula generated (canonic variable, CV) was validated on a group of seven SCLC and 22 NSCLC patients. Only two errors occurred. We therefore conclude that the canonic variable tested, based on NSE and CYFRA-21.1, provides a good discrimination between the two types of lung cancer. The method is rapid, relatively inexpensive, and based on simple serum tests

    Idiopathic Pulmonary Fibrosis (IPF) incidence and prevalence in Italy

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    Background: Studies of Idiopathic Pulmonary Fibrosis (IPF) epidemiology show regional variations of incidence and prevalence; no epidemiological studies have been carried out in Italy. Objective: To determine incidence and prevalence rates of IPF in the population of a large Italian region.Methods: in this cross-sectional study study data were collected on all patients of 18 years of age and older admitted as primary or secondary idiopathic fibrosing alveolitis (ICD9-CM 516.3) to Lazio hospitals, from 1/1/2005 to 31/12/2009, using regional hospital discharge, population and cause of death databases. Reporting accuracy was assessed on a random sample of hospital charts carrying the ICD9-CM 516.3, 516.8, 516.9 and 515 codes, by reviewing radiology and pathology findings to define cases as IPF “confident”, “possible” or “inconsistent”. Results: Annual prevalence and incidence of IPF were estimated at 25.6 per 100,000 and 7.5 per 100,000 using the ICD9-CM code 516.3 without chart audit while they were estimated at 31.6 per 100,000 and at 9,3 per 100,000 for the IPF “confident” definition after hospital chart audit. Conclusion: The data provide a first estimate of IPF incidence in Italy and indicate that incidence and prevalence in southern European regions may be similar to those observed in northern Europe and North America. (Sarcoidosis Vasc Diffuse Lung Dis 2014; 31: 191-197

    Assessment of portal hypertension severity using machine learning models in patients with compensated cirrhosis

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    Background & Aims: In individuals with compensated advanced chronic liver disease (cACLD), the severity of portal hypertension (PH) determines the risk of decompensation. Invasive measurement of the hepatic venous pressure gradient (HVPG) is the diagnostic gold standard for PH. We evaluated the utility of machine learning models (MLMs) based on standard laboratory parameters to predict the severity of PH in individuals with cACLD. Methods: A detailed laboratory workup of individuals with cACLD recruited from the Vienna cohort (NCT03267615) was utilised to predict clinically significant portal hypertension (CSPH, i.e., HVPG ≥10 mmHg) and severe PH (i.e., HVPG ≥16 mmHg). The MLMs were then evaluated in individual external datasets and optimised in the merged cohort. Results: Among 1,232 participants with cACLD, the prevalence of CSPH/severe PH was similar in the Vienna (n = 163, 67.4%/35.0%) and validation (n = 1,069, 70.3%/34.7%) cohorts. The MLMs were based on 3 (3P: platelet count, bilirubin, international normalised ratio) or 5 (5P: +cholinesterase, +gamma-glutamyl transferase, +activated partial thromboplastin time replacing international normalised ratio) laboratory parameters. The MLMs performed robustly in the Vienna cohort. 5P-MLM had the best AUCs for CSPH (0.813) and severe PH (0.887) and compared favourably to liver stiffness measurement (AUC: 0.808). Their performance in external validation datasets was heterogeneous (AUCs: 0.589-0.887). Training on the merged cohort optimised model performance for CSPH (AUCs for 3P and 5P: 0.775 and 0.789, respectively) and severe PH (0.737 and 0.828, respectively). Conclusions: Internally trained MLMs reliably predicted PH severity in the Vienna cACLD cohort but exhibited heterogeneous results on external validation. The proposed 3P/5P online tool can reliably identify individuals with CSPH or severe PH, who are thus at risk of hepatic decompensation. Impact and implications: We used machine learning models based on widely available laboratory parameters to develop a non-invasive model to predict the severity of portal hypertension in individuals with compensated cirrhosis, who currently require invasive measurement of hepatic venous pressure gradient. We validated our findings in a large multicentre cohort of individuals with advanced chronic liver disease (cACLD) of any cause. Finally, we provide a readily available online calculator, based on 3 (platelet count, bilirubin, international normalised ratio) or 5 (platelet count, bilirubin, activated partial thromboplastin time, gamma-glutamyltransferase, choline-esterase) widely available laboratory parameters, that clinicians can use to predict the likelihood of their patients with cACLD having clinically significant or severe portal hypertension

    Oesophageal varices predict complications in compensated advanced non-alcoholic fatty liver disease

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    Background & Aims: We aimed to evaluate the impact of oesophageal varices (OV) and their evolution on the risk of complications of compensated advanced chronic liver disease (cACLD) caused by non-alcoholic fatty liver disease (NAFLD). We also assessed the accuracy of non-invasive scores for predicting the development of complications and for identifying patients at low risk of high-risk OV. Methods: We performed a retrospective assessment of 629 patients with NAFLD-related cACLD who had baseline and follow-up oesophagogastroduodenoscopy and clinical follow-up to record decompensation, portal vein thrombosis (PVT), and hepatocellular carcinoma. Results: Small and large OV were observed at baseline in 30 and 15.9% of patients, respectively. The 4-year incidence of OV from absence at baseline, and that of progression from small to large OV were 16.3 and 22.4%, respectively. Diabetes and a ≥5% increase in BMI were associated with OV progression. Multivariate Cox regression revealed that small (hazard ratio [HR] 2.24, 95% CI 1.47–3.41) and large (HR 3.86, 95% CI 2.34–6.39) OV were independently associated with decompensation. When considering OV status and trajectories, small (HR 2.65, 95% CI 1.39–5.05) and large (HR 4.90, 95% CI 2.49–9.63) OV at baseline and/or follow-up were independently associated with decompensation compared with the absence of OV at baseline and/or follow-up. The presence of either small (HR 2.8, 95% CI 1.16–6.74) or large (HR 5.29, 95% CI 1.96–14.2) OV was also independently associated with incident PVT. Conclusion: In NAFLD-related cACLD, the presence, severity, and evolution of OV stratify the risk of developing decompensation and PVT. Impact and implications: Portal hypertension is the main driver of liver decompensation in chronic liver diseases, and its non-invasive markers can help risk prediction. The presence, severity, and progression of oesophageal varices stratify the risk of complications of non-alcoholic fatty liver disease. Easily obtainable laboratory values and liver stiffness measurement can identify patients at low risk for whom endoscopy may be withheld, and can also stratify the risk of liver-related complications

    Monitoring the quality of laboraties and the prevalence of resistance to antituberculosis drugs: Italy, 1998-2000

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    In 1998 a network of 20 regional tuberculosis (TB) laboratories (the Italian Multicentre Study on Resistance to Antituberculosis drugs (SMIRA) network) was established in Italy to implement proficiency testing and to monitor the prevalence of drug resistance nationwide. The network managed 30% of all TB cases reported in Italy each year. The aim of the present report is to describe: 1) the accuracy of drug-susceptibility testing in the network; 2) the prevalence of drug resistance for the period 1998-2000. Data were collected from the network laboratories. Sensitivity to streptomycin and ethambutol increased from the first survey (1998-1999) to the second survey (2000) from 87.7 to 91.9%. Specificity, predictive values for resistance and susceptibility, efficiency and reproducibility were consistent in both surveys. In previously untreated cases, the prevalence of multidrug-resistance was the same in both surveys (1.2%), while a slight decrease from the first to the second survey was observed for monoresistance to rifampicin (from 0.8 to 0.4%) and isoniazid (from 2.9 to 2%,). The significant association found between isoniazid resistance and immigration is a useful indicator for both clinicians managing individual tuberculosis cases and public health services planning control strategies

    Role of the berylliosis-associated HLA-DPGlu69 supratypic variant in determining the response to beryllium in a blood T-cells beryllium-stimulated proliferation test

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    Exposure to beryllium (Be) compounds may cause sensitization as revealed by blood T-cell proliferation against Be in a standardized Be-stimulated T-cell proliferation test (BeLPT). Further, susceptibility to Be hypersensitivity has been associated with the expression of HLA-DP allelic variants carrying a glutamate residue at position 69 of the beta-chain (HLA-DPGlu69) in more than 80% of affected subjects and, at lower frequency, with other HLA-DP, -DQ and -DR alleles/polymorphisms. The aim of this study was to assess whether heterozygous or homozygous carriage of the HLA-DPGlu69 marker may dictate the intensity of the T-cell response to Be in vitro
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