Search results for "TOXICITY"

The Antigerminative Activity of Twenty-Seven Monoterpenes

2010

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Toxicological properties of two fluorescent carbon quantum dots with onion ring morphology and their usefulness as bioimaging agents

2016

In the present work, two carbon quantum dots with onion ring morphology, C-NOR and C-NOR(Eu) with an average size of 40 nm differing in the absence or presence of Eu3+ as Lewis acids during their preparation were synthesized and fully characterized by several techniques. These nanoparticles can be internalized into human HeLa and Hep3B carcinoma cells where they exhibit interesting photoluminescent properties, in the same manner as in solution, confirming their utility as bioimaging agents. To address this possibility, a complete in vitro toxicological study has been performed here. Viability, proliferation, apoptosis and oxidative stress assessments upon limited or continuous exposure were…

Chronic toxicity of methylparathion to the rotifer Brachionus calyciflorus fed on Nannochloris oculata and Chlorella pyrenoidosa

1993

The effect of sublethal levels of methylparathion (0,1, 3, 5, 7 mg 1−1) on the freshwater rotifer, Brachionus calyciflorus, during their entire life cycle was studied. Rotifers were fed on two species of unicellular algae: Nannochloris oculata and Chlorella pyrenoidosa; both algal concentrations were 5 × 105 cell ml−1.

Inter- and intracellular signaling in amyotrophic lateral sclerosis: role of p38 mitogen-activated protein kinase.

2006

The pathogenetic processes underlying the selective motor neuron degeneration in amyotrophic lateral sclerosis (ALS) are complex and still not completely understood even in the cases of inherited disease caused by mutations in the Cu/Zn superoxide dismutase-dependent (SOD1) gene. Recent evidence supports the view that ALS is not a cell-autonomous disease and that glial-neuron cross-talk, throughout cytokines and other toxic factors like the nitric oxide and superoxide, is a crucial determinant for the induction of motor neuron death. This cell-cell interaction may determine the progression of the disease through processes that are likely independent of the initial trigger and that may conve…

Waterless Cleaning Compositions with Disinfection Properties: Efficacy and Environmental Aspects / Bezûdens Tîrîðanas Lîdzekïi Ar Dezinficçjoðo Iedar…

2015

Abstract The microbial ecology of different indoor environments determines the human microbiome. Hence, cleaning and disinfection of indoor environments like hospitals, apartments, automobiles, etc. are of great importance. Nonaqueous surface cleaning preparations (SCPs) are often used for this purpose. A cleaning composition may contain the following compounds: primary surfactant, cosurfactant, solvent, cosolvent, organotropic (organic solubilizing) agent, hydrotropic (water solubilising) agent, water and salts, and special additives. In this paper, the efficacy of complex preparations is discussed, focusing on the chemical composition and testing methods. Particular attention is paid to q…

Predictability and prediction of lowest observed adverse effect levels in a structurally heterogeneous set of chemicals

2005

A database of chronic lowest observed adverse effect levels (LOAELs) for 234 compounds, previously compiled from different sources (Toxicology Letters79, 131-143 (1995)), was modelled using graph theoretical descriptors. This study reveals that data are not homogeneous. Only those data originating from the U.S. Environmental Protection Agency (EPA) reports could be well modelled by multilinear regression (MLR) and linear discriminant analysis (LDA). In contrast, data available from the specific procedures of the National Toxicology Program (NTP) database introduced noise and did not render good models either alone, or in combination with the EPA data.

Structural invariants for the prediction of relative toxicities of polychloro dibenzo-p-dioxins and dibenzofurans

2004

Multivariate models are reported that can predict the relative toxicity of compounds with severe environmental impact, namely polychloro dibenzo-p-dioxins (PCDDs) and dibenzofurans (PCDFs). Multiple linear regression analysis (MLR) and partial least square projections of latent variables (PLS) show the usefulness of graph-theoretical descriptors, mainly topological charge indices (TCIs), in these series. The general trends of the group are correctly reproduced and better results are presented than have previously been published. In general, the more toxic compounds exhibit more symmetric molecular structures.

Pretrichodermamide C and N-methylpretrichodermamide B, two new cytotoxic epidithiodiketopiperazines from hyper saline lake derived Penicillium sp.

2015

Abstract Two new epidithiodiketopiperazines, pretrichodermamide C (1) and N-methylpretrichodermamide B (2) were isolated from the fungus Penicillium sp., derived from the sediment of a hyper saline lake located at Wadi El-Natrun in Egypt. The structures of 1 and 2 were unambiguously determined on the basis of one- and two-dimensional NMR spectroscopy and by high-resolution mass spectrometry, as well as by comparison with the literature. Compound 2 showed pronounced cytotoxicity against the murine lymphoma L5178Y cell line with an IC50 value of 2 μM.

Oligomerization of Concanavalin A in live cells detected by fluctuation analysis.

2009

MDMA Administration and Heat Shock Proteins Response: Foreseeing a Molecular Link

2010

Molecular and cellular mechanisms of MDMA-induced toxicity have been extensively studied in a number of experimental models. Nevertheless, only few studies investigated the involvement of HSPs ("molecular chaperones") in MDMA organs toxicity. In the present minireview we highlight this subject analysing the results of these studies conducted especially on brain tissue. Despite of it seems obvious that HSPs overexpression is a protective reaction against MDMA treatment, the molecular mechanisms for exerting their action are far to be undiscovered. At the same time, we need of comprehensive studies concerning the whole range of Hsps/chaperones expressions in all organs after acute and chronic…