Search results for "TOXICOLOGY"
showing 10 items of 4114 documents
Metabolic detoxification: implications for thresholds.
2000
The fact that chemical carcinogenesis involves single, isolated, essentially irreversible molecular events as discrete steps, several of which must occur in a row to finally culminate in the development of a malignancy, rather suggests that an absolute threshold for chemical carcinogens may not exist. However, practical thresholds may exist due to saturable pathways involved in the metabolic processing, especially in the metabolic inactivation, of such compounds. An important example for such a pathway is the enzymatic hydrolysis of epoxides via epoxide hydrolases, a group of enzymes for which the catalytic mechanism has recently been established. These enzymes convert their substrates via…
Cadmium, Copper and Tributyltin effects on fertilization of Paracentrotus lividus (Echinodermata)
2009
Marine environments are continuously being threatened by a large number of xenobi- otics from anthropogenic sources. The effect of chemical pollution on living organisms are numerous and may impair reproductive success of adults species of marine invertebrate and vertebrate through effects on gamete quality. Echinoderms are characterized by external fertilizzation and gametes, free of any type of protection, may be in contact with toxic substances so the reproductive success depends largely on the environment conditions. The purpose of this work is to assess the effects on the in vitro fertiliza- tion of exposure of sea urchin Paracentrotus lividus gametes to xenobiotic substances as CuSO4,…
Statement complementing the EFSA Scientific Opinion on application (EFSA‐GMO‐DE‐2011‐95) for the placing on the market of genetically modified maize …
2018
Abstract The GMO Panel was previously not in the position to complete the food/feed safety assessment of maize 5307 due to an inadequate 28‐day toxicity study necessary for an appropriate assessment of eCry3.1Ab protein. Following a mandate from the European Commission, the GMO Panel assessed a supplementary 28‐day toxicity study in mice on the eCry3.1Ab protein (1,000 mg/kg body weight (bw) per day) to complement its scientific opinion on application EFSA‐GMO‐DE‐2011‐95 for the placing on the market of the maize 5307 for food and feed uses, import and processing. The supplementary 28‐day toxicity study did not show adverse effects. Taking into account the previous assessment and the new in…
Assessment of genetically modified sugar beet H7‐1 for renewal of authorisation under Regulation (EC) No 1829/2003 (application EFSA‐GMO‐RX‐006)
2017
Efsa Panel On Genetically Modified Organisms (gmo)Scientific opinionRequestor: European Commission (DG SANTE)Question number: EFSA-Q-2017-00026; Following the submission of application EFSA-GMO-RX-006 under Regulation (EC) No 1829/2003 fromKWS SAAT SE and Monsanto Company, the Panel on Genetically Modified Organisms of the EuropeanFood Safety Authority (GMO Panel) was asked to deliver a scientific risk assessment on the datasubmitted in the context of the renewal of authorisation application for the herbicide-tolerantgenetically modified sugar beet H7-1. The data received in the context of this renewal applicationcontained a systematic search and evaluation of literature, updated bioinforma…
Understanding the Influence of Eating Patterns on Binge Drinking: A Mediation Model
2020
Background: Binge drinking is an important health problem, and it has been related to binge eating and fat intake in animal models, but this relationship has not been tested in humans. The first objective of this study was to analyze whether binge eating and fat intake are related to binge drinking in a youth sample. The second objective was to analyze whether binge eating and fat intake mediate the relationship between individual factors associated with binge eating and fat intake (sex, body mass index (BMI), drive for thinness, body dissatisfaction, eating styles, impulsivity, and food addiction) and binge drinking. Methods: A sample of 428 undergraduate students filled out several questi…
Testing the Intermediary Role of Perceived Stress in the Relationship between Mindfulness and Burnout Subtypes in a Large Sample of Spanish Universit…
2020
The burnout syndrome is the consequence of chronic stress that overwhelms an individual&rsquo
Stereochemical features of the hydrolysis of 9,10-epoxystearic acid catalysed by plant and mammalian epoxide hydrolases
2002
cis-9,10-Epoxystearic acid was used as a tool to probe the active sites of epoxide hydrolases (EHs) of mammalian and plant origin. We have compared the stereochemical features of the hydrolysis of this substrate catalysed by soluble and membrane-bound rat liver EHs, by soluble EH (purified to apparent homogeneity) obtained from maize seedlings or celeriac roots, and by recombinant soybean EH expressed in yeast. Plant EHs were found to differ in their enantioselectivity, i.e. their ability to discriminate between the two enantiomers of 9,10-epoxystearic acid. For example, while the maize enzyme hydrated both enantiomers at the same rate, the EH from soybean exhibited very high enantioselecti…
Colorimetric quantitation of trace amounts of sodium lauryl sulfate in the presence of nucleic acids and proteins
1992
A fast and sensitive procedure for the colorimetric detection of sodium lauryl sulfate (SDS) is presented. The assay is based upon the formation of a chloroform-extractable ion pair between lauryl sulfate and methylene blue that is quantified spectrophotometrically with an estimated detection limit of 150 ng of SDS. The method is suitable for the monitoring of contaminating traces of SDS in protein or nucleic acid samples that have the potential to interfere with enzymatic manipulations such as proteolytic digest, restriction analysis, or reverse transcription. Since the procedure is extremely simple and no special equipment is required it is accessible to every researcher concerned with SD…
Effective and environmental half-lives of radiocesium in game from Poland.
2021
For the first time changes in the 137Cs activity in game throughout Poland, including its most contaminated part known as the Opole Anomaly, were analyzed. Due to its long physical half-life, 137Cs continuously demonstrates high activity both in soil and biota. The species of game mammals, along with forest fruit and mushrooms, tend to accumulate this radionuclide, becoming one of the main sources of secondary contamination in people. In this study the 137Cs activity in roe deer, wild boar and red deer muscle tissue samples, within the years of 1986–2019, were studied. The effective and environmental half-lives were determined for each of the mentioned species for four regions including NE …
Substituted Dibenzothiophenes I: Synthesis, Chromatography, Mass Spectrometry and Structure Elucidation by1H NMR Spectroscopy
1992
Abstract Some polychlorinated and polymethylated dibenzothiophenes have been synthesized to serve as model compounds in environmental analysis. In order to obtain pure isomers, the synthesis mixtures have been fractionated with reversed-phase high performance liquid chromatography. In spite of a high sensitivity, mass spectrometry does not provide any reliable way to determine the precise structures of different isomers. Therefore, 1H NMR spectroscopy has been utilized as an aid in their analysis. The structures for two isomeric tetramethyldibenzothiophenes could be suggested on the basis of their 1H NMR spectra. Also some proposals for possible structures of two isomeric trimethyldibenzoth…