Search results for "Transformation"

Unexpected DNA damage caused by polycyclic aromatic hydrocarbons under standard laboratory conditions

2007

Abstract The genotoxicity of 15 polycyclic aromatic hydrocarbons was determined with the alkaline version of the comet assay employing V79 lung fibroblasts of the Chinese hamster as target cells. These cells lack the enzymes necessary to convert PAHs to DNA-binding metabolites. Surprisingly, 11 PAHs, i.e., benzo[ a ]pyrene (BaP), benz[ a ]anthracene, 7,12-dimethylbenz[ a ]anthracene, 3-methylcholanthrene, fluoranthene, anthanthrene, 11 H -benzo[ b ]fluorene, dibenz[ a,h ]anthracene, pyrene, benzo[ ghi ]perylene and benzo[ e ]pyrene caused DNA strand breaks even without external metabolic activation, while naphthalene, anthracene, phenanthrene and naphthacene were inactive. When the comet as…

Fast Decentralized Linear Functions via Successive Graph Shift Operators

2019

Decentralized signal processing performs learning tasks on data distributed over a multi-node network which can be represented by a graph. Implementing linear transformations emerges as a key task in a number of applications of decentralized signal processing. Recently, some decentralized methods have been proposed to accomplish that task by leveraging the notion of graph shift operator, which captures the local structure of the graph. However, existing approaches have some drawbacks such as considering special instances of linear transformations, or reducing the family of transformations by assuming that a shift matrix is given such that a subset of its eigenvectors spans the subspace of i…

Standard classes on the blow-up of $\mathbb{P}^n$ at points in very general position

2012

Individual and Collaborative Semiotic Work in Document Design

2017

This article examines the concepts of agency, transformation and transduction in the context of document design. These concepts have been previously used to describe communicative actions and sign-making among individuals: whereas agency focuses on the individual’s capabilities as a sign-maker, transformation and transduction describe how individuals transform meanings within one mode of communication or from one mode to another. Organizational communication, however, is rarely an individual effort, particularly in corporate settings: producing multimodal documents that communicate on behalf of entire organizations, such as annual reports, constitutes a collaborative effort involving a vari…

The use of cultured hepatocytes to investigate the metabolism of drugs and mechanisms of drug hepatotoxicity.

2001

Hepatotoxins can be classified as intrinsic when they exert their effects on all individuals in a dose-dependent manner, and as idiosyncratic when their effects are the consequence of an abnormal metabolism of the drug by susceptible individuals (metabolic idiosyncrasy) or of an immune-mediated injury to hepatocytes (allergic hepatitis). Some xenobiotics are electrophilic, and others are biotransformed by the liver into highly reactive metabolites that are usually more toxic than the parent compound. This activation process is the key to many hepatotoxic phenomena. Mitochondria are a frequent target of hepatotoxic drugs, and the alteration of their function has immediate effects on the ene…

Hypoxia-inducible factor 1 alpha expression increases during colorectal carcinogenesis and tumor progression

2008

Abstract Background Hypoxia-inducible factor 1 alpha (HIF-1α) is involved in processes promoting carcinogenesis of many tumors. However, its role in the development of colorectal cancer is unknown. To investigate the significance of HIF-1α during colorectal carcinogenesis and progression we examined its expression in precursor lesions constituting the conventional and serrated pathways, as well as in non-metastatic and metastatic adenocarcinomas. Methods Immunohistochemistry and Western blot is used to analyse HIF-1α expression in normal colonic mucosa, hyperplastic polyps (HPP), sessile serrated adenomas (SSA), low-grade (TA-LGD) and high-grade (TA-HGD) traditional adenomas as well as in n…

Transformation of primary human hepatocytes in hepatocellular carcinoma

2015

Hepatocellular carcinoma (HCC) is the most common primary liver cancer. Currently, there is limited knowledge of neoplastic transformation of hepatocytes in HCC. In clinical practice, the high rate of HCC local recurrence suggests the presence of different hepatocyte populations within the liver and particularly in the tumor proximity. The present study investigated primary human hepatocyte cultures obtained from liver specimens of patients affected by cirrhosis and HCC, their proliferation and transformation. Liver samples were obtained from seven HCC cirrhotic patients and from three patients with normal liver (NL). Immediately after surgery, cell outgrowth and primary cultures were obtai…

Validation of a semi-physiological model for caffeine in healthy subjects and cirrhotic patients.

2015

The objective of this paper was to validate a previously developed semi physiological model to simulate bioequivalence trials of drug products. The aim of the model was to ascertain whether the measurement of the metabolite concentration-time profiles would provide any additional information in bioequivalence studies (Fernandez-Teruel et al., 2009a,b; Navarro-Fontestad et al., 2010). The semi-physiological model implemented in NONMEM VI was used to simulate caffeine and its main metabolite plasma levels using caffeine parameters from bibliography. Data from 3 bioequivalence studies in healthy subjects at 3 different doses (100, 175 and 400mg of caffeine) and one study in cirrhotic patients …

Stability of hydrodynamical relativistic planar jets : II. Long-term nonlinear evolution

2004

In this paper we continue our study of the Kelvin-Helmholtz (KH) instability in relativistic planar jets following the long-term evolution of the numerical simulations which were introduced in Paper I. The models have been classified into four classes (I to IV) with regard to their evolution in the nonlinear phase, characterized by the process of jet/ambient mixing and momentum transfer. Models undergoing qualitatively different non-linear evolution are clearly grouped in well-separated regions in a jet Lorentz factor/jet-to-ambient enthalpy diagram. Jets with a low Lorentz factor and small enthalpy ratio are disrupted by a strong shock after saturation. Those with a large Lorentz factor an…

Minkowski-Lorentz Spaces Applications: Resolution of Apollonius and Dupin Problems

2019

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