174 research outputs found

    Lockdown: Dynamic Control-Flow Integrity

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    Applications written in low-level languages without type or memory safety are especially prone to memory corruption. Attackers gain code execution capabilities through such applications despite all currently deployed defenses by exploiting memory corruption vulnerabilities. Control-Flow Integrity (CFI) is a promising defense mechanism that restricts open control-flow transfers to a static set of well-known locations. We present Lockdown, an approach to dynamic CFI that protects legacy, binary-only executables and libraries. Lockdown adaptively learns the control-flow graph of a running process using information from a trusted dynamic loader. The sandbox component of Lockdown restricts interactions between different shared objects to imported and exported functions by enforcing fine-grained CFI checks. Our prototype implementation shows that dynamic CFI results in low performance overhead.Comment: ETH Technical Repor

    her2 status in premalignant dysplastic gastric lesions

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    Abstract is not required for Editorialis not required for Editorial (This page in not part of the published article.) International Journal of Case Reports and Images, Vol. 6 No. 8, August 2015. ISSN – [0976-3198] Int J Case Rep Images 2015;6(8):530–533. www.ijcasereportsandimages.com Barresi et al. 530 CASE REPORT OPEN ACCESS HER2 status in premalignant dysplastic gastric lesions Valeria Barresi, Antonio Ieni, Giovanni Tuccari The epidermal growth factor receptor family is constituted by four members with similar structures: HER1/erbB1, HER2/erbB2, HER3/erbB3 and HER4/ erbB4. These receptors play an important role in the processes of proliferation and differentiation of normal cells [1]. The binding of the ligand to these receptors causes the creation of homodimers and heterodimers as well as the activation of downstream signaling pathways [1]. Hence, any aberrations in their structure or function can cause transformation of normal cells to malignant cells with consequent tumor development and progression [1]. However, on the basis of results from an international randomized controlled trial (ToGA), the patients with advanced gastric adenocarcinoma (GC) positive for HER2 over-expression could be eligible for a target treatment with trastuzumab [2]. A significant reduction in the risk of mortality was appreciable when trastuzumab was added to the chemotherapy regimen [2]. There is general agreement with regard to a higher HER2 positivity in gastroesophageal junction cancer (24–35%) compared with GC (9.5–21%) [3]. The rate of HER2 immunoreactivity seemed to be vary variable in relation to the different neoplastic histotype of the stomach [4]. Generally, all studies have reported a prevalence of HER2 amplification in advanced GC of Valeria Barresi1, Antonio Ieni1, Giovanni Tuccari1 Affiliations: 1Azienda Ospedaliera Universitaria "Gaetano Martino" and Department of Human Pathology "Gaetano Barresi", Section of Anatomic Pathology, University of Messina, Messina 98123, Italy. Corresponding Author: Giovanni Tuccari, MD, Full Professor of Pathology Department of Human Pathology, "Gaetano Barresi" University of Messina, A.O.U. "Policlinico G. Martino" Pad. D, Via Consolare Valeria, 98125 – MESSINA (Italy); Ph: +39-90-2212539; Fax:+39-90-2928150 E-mail: [email protected] Received: 16 June 2015 Published: 01 August 2015 EdiTO iAlS OPEN A CE S intestinal type (81.6–91%) in comparison with diffuse or mixed ones (4–7.9%) [4]. In addition, a progressive increase in HER2 overexpression has been appreciated moving from the poorly cohesive WHO histotype to mitochondrion-rich adenocarcinomas (MRC), tubular adenocarcinomas and hepatoid carcinomas (HAS), these latter representing the top rate of HER2 positivity, characterized by an extremely poor prognosis [4]. Furthermore, HER2 overexpression was also significantly associated with a high grade, advanced stage and high Ki67-LI value, becoming thus an additional morphological parameter able to affect the mortality of patients with GC [5]. Finally, some investigations have been recently reported regarding the concordance of HER status in primary gastric cancer and corresponding lymph nodes or distant metastases, with either positive or negative conversion in HER2 overexpression [6, 7]. Generally speaking, chronic atrophic gastritis and intestinal metaplasia of the stomach have been regarded to as pre-neoplastic lesions, even if data from literature points towards the existence of other pathways, in which intestinal metaplasia may not play a role, as described by Japanese authors [8]. However, the true precancerous gastric lesion should be considered dysplasia, which includes cellular and structural atypia, also codified under the term intraepithelial neoplasia (IEN), a pathological condition that lies between atrophic gastritis and GC [9]. It is well known, that IEN may develop in the gastric or intestinal metaplastic epithelium and it can be categorized into four categories: indefinite for intraepithelial neoplasia, low-grade intraepithelial neoplasia (LG-IEN), high-grade intraepithelial neoplasia (HG-IEN) and suspicious for invasive cancer [10]. The IEN histological distinction as low or high-grade depends on the severity of architectural and cytological atypia. In LG-IEN, the mucosal structure is only faintly modified maintaining tubular differentiation with the proliferative zone limited to the outward portion, whereas HG-IEN exhibits increasing distortion of the mucosal architecture, resulting in crowded possibly irregular glands with obvious cellular atypia and proliferative activity distributed throughout the lesion [10]. High-grade intraepithelial neoplasia i

    Expression of cytokeratin 7 and 20 in pathological conditions of the bile tract

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    Expression of cytokeratin 7 (CK7) and cytokeratin 20 (CK20) helps to establish the origin of biliary and metastatic carcinomas. We investigated the expression of CK7 and CK20 in inflammatory, metaplastic and neoplastic conditions of the bile ducts, and evaluated possible relationships between the CK expression pattern and extrahepatic bile duct/gallbladder carcinomas (EBDCs) or intrahepatic bile duct carcinomas (IBDCs). We used immunohistochemistry for the investigation of 48 formalin-fixed, paraffin-embedded specimens grouped as: A) lithiasic or inflamed surgically resected extrahepatic bile ducts/gallbladders: all were CK7+/CK20+; B) percutaneous liver biopsies from patients with chronic hepatitis C primary biliary cirrhosis and primary sclerosing cholangitis: all were CK7+/CK20-; C) EBDCs: all were CK7+/CK20+, except for two cases which were CK7-/CK20-; D) IBDCs: all were CK7+/CK20-, except for one case showing CK20 positivity. Metaplastic changes were seen only among specimens in groups A and C: in these cases, CK20 was either focally or diffusely expressed. Our study suggests that the expression of cytokeratins under specific stimuli can be different from normal tissues, and that sometimes CK20 expression can be related to and precede the occurrence of metaplastic alterations

    An Updated Review of Cribriform Carcinomas with Emphasis on Histopathological Diagnosis and Prognostic Significance

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    Cribriform is a histopathological term used to describe a neoplastic epithelial proliferation in the form of large nests perforated by many quite rounded different-sized spaces. This growth pattern may be seen in carcinomas arising in different organs, and shows important prognostic implications. Therefore, recent data in literature suggest that cribriform carcinoma is a histologically and clinically distinctive type of tumour that should be separated from other similar tumour types. In this article, the pathology of cribriform adenocarcinoma of the prostate, lung, breast, stomach, colon, thyroid, and skin is discussed with particular reference to morphologic and immunohistochemical features, differential diagnosis, and clinical behaviour

    An experimental and modeling combined approach in preparative Hydrophobic Interaction Chromatography

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    Chromatography is a technique widely used in the purification of biopharmaceuticals, and gener-ally consists of several chromatographic steps. In this work, Hydrophobic Interaction Chroma-tography (HIC) is investigated as a polishing step for the purification of therapeutic proteins. Ad-sorption mechanisms in hydrophobic interaction chromatography are still not completely clear and a limited amount of published data is available. In addition to new data on adsorption isotherms for some proteins (obtained both by high-throughput and frontal analysis method), and a comparison of different models proposed in the literature, two different approaches are compared in this work to investigate HIC. The predictive approach exploits an in-house code that simulates the behavior of the component in the column using the model parameters found from the fitting of experimental data. The estimation approach, on the other hand, exploits commercial software in which the model parameters are found by the fitting of a few experimental chromatograms. The two approaches are validated on some bind-elute runs: the predictive approach is very informative, but the experi-mental effort needed is high; the estimation approach is more effective, but the knowledge gained is lower. The second approach is also applied to an in-development industrial purification process and successfully resulted in predicting the behavior of the system, allowing for optimization with a reduction in the time and amount of sample needed
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