Topics in the arithmetic of Del Pezzo and K3 surfaces

In this thesis we study the arithmetic of certain del Pezzo surfaces and K3 surfaces.We prove that all the del Pezzo surfaces of degree 2 over a finite field are unirational. We compute the Picard lattice of the members of a family of K3 surfaces given by double covers of the projective plane. Finally, we provide an explicit example of a K3 surface over the field of rational numbers with a particular Picard lattice of rank 2

Topics in the arithmetic of del Pezzo and K3 surfaces

  In this thesis we study the unirationality of del Pezzo surfaces of degree 2 over finite fields, proving that every such surface is unirational. We explicitly compute the Picard lattice of the members of a 1-dimensional family of K3 surfaces. We produce an explicit example of a K3 surface having a particular Picard lattice of rank 2.  ALGANTNumber theory, Algebra and Geometr

Are the Expanded Baveno VI Criteria really safe to screen compensated cirrhotic patients for high-risk varices?

The Expanded Baveno VI criteria [1] have been recently proposed as a new screening strategy for high-risk varices (HRV), able to increase the rate of spared upper endoscopies (EGDs) and improve upon the original Baveno VI Criteria [2]. To date, few studies have investigated the performance and safety of these criteria [3,4]. The recent work by Bae et al. [4] is the first one to report a high rate (>5%) of missed HRV by the expanded criteria, questioning their efficiency in safely ruling out HRV (sensitivity 81%, NPV 93%, LR- 0.30

Peningkatan Kemampuan Public Speaking melalui Metode Pelatihan Anggota Forum Komunikasi Remaja Islam

Public speaking is the process of speaking to a group of people in a structured, deliberate manner intended to inform, influence, or entertain the listeners. Speaking in front of audience is not an easy task. It needs a good speaking skill. Fear and nervousness become major problem, especially for beginners who have not experienced in public speaking. This also occurs in members of the Muslim Youth Forum Gayamsari (Foksari). Their speaking competence is inadequate. That is why Public Speaking training activity is held. It is expexted to improve their skills. This activity is performed in two stages, namely the delivery of content and practice. Based on the evaluation, the results obtained are very significant. The existence of enthusiastic participants indicates that they are very interested. Besides, there is a seriousness of the participants who attend a series of events organized by the team from beginning to end

Interleukin 28 polymorphisms and hepatocellular carcinoma development after direct acting antiviral therapy for chronihepatitis c

Background & Aims: Cirrhotic patients with hepatitis C virus (HCV) infection remain at risk of developing hepatocellular carcinoma (HCC) even after the sustained virologic response (SVR). We aimed to evaluate whether the IL28 (rs12979860) single nucleotide polymorphism (SNP) may constitute a predisposing genetic factor and to identify the SVR patients at risk of HCC. Methods: Two hundred patients undergoing DAAs treatment for chronic hepatitis C with advanced fibrosis (F3-F4) were consecutively enrolled. Besides normal routine laboratory testing for HCV, patients’ sera were evaluated also for retinol, retinol-binding protein 4 and the following SNPs: PNPLA3 (rs738409), TM6SF2 (rs58542926), MBOAT7 (rs641738), IL28B (rs12979860), TIMP-1 (rs4898), TIMP-2 (rs8179090), NF-kB promoter (rs28362491). Statistical analyses were conducted using Stata/SE 14.2 statistical software (Stata Corp, College Station, TX). Results: Almost all patients (197/200) obtained SVR24. Seventeen patients had a previous history of treated HCC before DAAs. Six patients developed HCC recurrence and five patients developed de novo HCC after a mean period of 18 months since EOT. All these patients had SVR. A significant association between IL28B – TT genotype and HCC development after DAAs therapy was observed (OR 4.728, CI 95% 1.222 – 18.297, p=0.024). Conclusion: IL28B rs12979860 polymorphism was significantly associated with HCC development after DAAs. Assessment of this SNP may better identify patients at risk of developing HCC after treatment. Further prospective studies are required to confirm these hypotheses

Non-invasive tests for the prediction of post-hepatectomy liver failure in the elderly

Post-hepatectomy liver failure (PHLF) is associated with great morbidity and mortality after resection of hepatocellular carcinoma. Previous studies have underlined that advanced age could be a potential factor influencing post-operative complications and long-term survival. In the past, candidates for resection were based on the Child-Pugh classification, the predictive value of which was rather low. The selection of patients undergoing resection in Western countries is based on the assessment of portal hypertension (PH), which is clinically assessed by measurement of the hepatic venous pressure gradient, an invasive and costly process. Thus, there have been several attempts to identify the best non-invasive test (NIT) to accurately predict PHLF. Most biochemical NITs for the prediction of PHLF are focused on evaluation of underlying liver cirrhosis and PH. Amongst them, FIB-4, which also includes the patient’s age, seems to have more robust supporting results. In Europe and the USA., the most tested and reliable NIT for predicting PHLF is the evaluation of liver stiffness measurement, which is also influenced by age. Imaging parameters are promising tools which are used only in specialized centers however, and when available. Liver volume parameters, as well as contrast-enhanced data, demonstrate good accuracy in predicting PHLF. In this scenario, the evaluation of sarcopenia and bone mineral density through contextual imaging allows the delineation of PHLF in at-risk elderly patients. Further studies focused on parameters for the evaluation of PHLF in elderly patients are needed

A combined model based on spleen stiffness measurement and Baveno VI criteria to rule out high-risk varices in advanced chronic liver disease

BACKGROUND & AIMS: Recently, Baveno VI guidelines suggested that esophagogastroduodenoscopy (EGD) can be avoided in patients with compensated advanced chronic liver disease (cACLD) who have a liver stiffness measurement (LSM) 150,000/mm3. We aimed to: assess the performance of spleen stiffness measurement (SSM) in ruling out patients with high-risk varices (HRV); validate Baveno VI criteria in a large population and assess how the sequential use of Baveno VI criteria and SSM could safely avoid the need for endoscopy. METHODS: We retrospectively analyzed 498 patients with cACLD who had undergone LSM/SSM by transient elastography (TE) (FibroScan®), platelet count and EGDs from 2012 to 2016 referred to our tertiary centre. The new combined model was validated internally by a split-validation method, and externally in a prospective multicentre cohort of 115 patients. RESULTS: SSM, LSM, platelet count and Child-Pugh-B were independent predictors of HRV. Applying the newly identified SSM cut-off (≤46 kPa) or Baveno VI criteria, 35.8% and 21.7% of patients in the internal validation cohort could have avoided EGD, with only 2% of HRVs being missed with either model. The combination of SSM with Baveno VI criteria would have avoided an additional 22.5% of EGDs, reaching a final value of 43.8% spared EGDs, with <5% missed HRVs. Results were confirmed in the prospective external validation cohort, as the combined Baveno VI/SSM ≤46 model would have safely spared (0 HRV missed) 37.4% of EGDs, compared to 16.5% when using the Baveno VI criteria alone. CONCLUSIONS: A non-invasive prediction model combining SSM with Baveno VI criteria may be useful to rule out HRV and could make it possible to avoid a significantly larger number of unnecessary EGDs compared to Baveno VI criteria only. LAY SUMMARY: Spleen stiffness measurement assessed by transient elastography, the most widely used elastography technique, is a non-invasive technique that can help the physician to better stratify the degree of portal hypertension and the risk of esophageal varices in patients with compensated advanced chronic liver disease. Performing spleen stiffness measurement together with liver stiffness measurement during the same examination is simple and fast and this sequential model can identify a greater number of patients that can safely avoid endoscopy, which is an invasive and expensive examination

Predictive factors for hepatocellular carcinoma recurrence after curative treatments

Hepatocellular carcinoma (HCC) is the fifth most common neoplasm worldwide. Recurrence of HCC after resection or loco-regional therapies represents an important clinical issue as it affects up to 70% of patients. This can be divided into early or late, if it occurs within or after 24 months after treatment, respectively. While the predictive factors for early recurrence are mainly related to tumour biology (local invasion and intrahepatic metastases), late recurrences are mainly related to de novo tumour formation. Thus, it is important to recognize these factors prior to any treatment in each patient, in order to optimize the treatment strategy and follow-up after treatment. The aim of this review is to summarize the current evidence available regarding predictive factors for the recurrence of HCC, according to the different therapeutic strategies available. In particular, we will discuss the role of new ultrasound-based techniques and biological features, such as tumor-related and circulating biomarkers, in predicting HCC recurrence. Recent advances in imaging-related parameters in computed-tomography scans and magnetic resonance imaging will also be discussed

Farnesyltransferase inhibitors and human malignant pleural mesothelioma: a first-step comparative translational study.

It is known that the potential clinical use of farnesyltransferase inhibitors (FTI) could be expanded to include cancers harboring activated receptor tyrosine kinases. Approximately 70% of malignant pleural mesotheliomas (MPM) overexpress epidermal growth factor receptors (EGFR) and a subset express both EGFR and transforming growth factor A (TGF-A), suggesting an autocrine role for EGFR in MPM. We checked on MPM cells (10 human cell lines, 11 primary cultures obtained by human biopsies, and 7 short-term normal mesothelial cell cultures) concerning the following: (a) the relative overexpression of EGFR (Western blotting, flow cytometry, immunohistochemistry), (b) the relative expression of EGFR ligands (EGF, amphiregulin, TGF-A, ELISA), (c) the relative increase of the activated form of Ras (Ras-bound GTP) after EGF stimulation (Ras activation assay), (d) the efficacy of five different FTIs (HDJ2 prenylation, cell cytotoxicity, and apoptosis using ApopTag and gel ladder). EGFR was overexpressed in MPM cells compared with normal pleural mesothelial cells in equivalent levels as in non\u2013small cell lung cancer cells A549. MPM cells constitutively expressed EGFR ligands; however, Ras activation was attenuated at high EGF concentrations (100 ng/mL). Growth of MPM cells was substantially not affected by treatment with different FTIs (SCH66336, BMS- 214662, R115777, RPR-115135, and Manumycin). Among these, BMS-214662 was the only one moderately active. BMS-214662 triggered apoptosis in a small fraction of cells (not higher than 30%) that was paralleled by a slight decrease in the levels of TGF-A secreted by treated MPM cells. Our data highlighted the concept that the same signaling pathway can be regulated in different ways and these regulations can differ between different cells of different origin

A Novel FibroScan Examination Dedicated to Spleen Stiffness Measurement.

Esophageal varices (EVs) are among the most severe complications of cirrhosis, with a prevalence of 50% to 60% among cirrhotic patients. International guidelines therefore recommend that cirrhotic patients should be screened for the presence of EVs. The main objective of this study was to introduce a new spleen-dedicated FibroScan (Echosens, Paris, France) examination and to assess its performance in detecting large EVs (grade 2 and 3). This novel examination has been validated in simulation and phantom studies and has been used in a population of patients with chronic liver disease. The study described here suggests that the novel spleen-dedicated FibroScan examination performs better than the standard FibroScan for the detection of large EVs (area under the curve = 0.70 for the standard examination and 0.79 [p &lt;0.01] for the spleen examination), but further clinical studies are needed to investigate the role of spleen stiffness in the management of cirrhotic patients