125 results match your criteria: "National Institute of Toxicology[Affiliation]"

In order to compare the effects of cocaine at morphological, basal cytotoxicity, biochemical and molecular levels, cultured mouse neuroblastoma cells (Neuro-2a) were exposed to a range of concentrations of cocaine hydrochloride. Neuroblastoma cell proliferation, evaluated by quantification of total protein content, was very sensitive to cocaine, being increasingly inhibited from 12 to 72 hr of exposure (EC(50) = 3.1 mm at 24 hr).

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Polygodial is a natural sesquiterpene which exhibits pronounced pungency and a powerful antifeedant activity. At low concentrations, which do not alter general cell membrane permeability, polygodial increases the intracellular concentration of free calcium ([Ca(2+)](i)). Sensory neurotransmission depends on noradrenaline (NA) release, and vesicular exocytosis, in turn, is dependent on an increase in [Ca(2+)](i).

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A retrospective study of telephone calls concerning poisoning due to pharmaceutical products, attended by the Toxicological Information Service in Seville (Spain), is presented. The years 1993 and 1994 were analized. Demographic data including the age and sex of the patient, route of exposure, cause, type of poisoning and the therapeutic group, was obtained.

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A 12-year-old girl was taken to the Virgen Macarena Universitary Hospital in Seville, Spain, complaining of abdominal pain, nausea, palpitations, and difficulty in breathing. Her school teacher informed that the girl collapsed after a 100-m race at sports in school. Emergency rescue personnel found the patient pale, in a cold sweat, with low peripheral perfusion.

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Background: Poisoning caused by drugs of abuse or commonly used addictive medicines occurs with relative frequency and often leads, either directly or indirectly, to death. The interpretation of the blood and urine concentrations is, however, a complex and difficult problem.

Methods: We have reviewed the published data and subjected them to selection and unification on the basis of conservative criteria and our own experience.

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A retrospective study of 46 poisonings in children due to detergents, cleansing agents and bleach in 1994 and reported to the Toxicological Information Service in Seville (Spain) is presented. Most children affected were under the age of 4. The most frequent products implicated were dishwashing liquids, degreasers and bleach, and then glass cleaners and general household cleansing agent.

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The toxic effects of two metabolic inhibitors, dinitrophenol and iodoacetic acid, were compared. Mouse neuroblastoma cell cultures (Neuro-2a) were exposed to different concentrations of the toxic compounds for 24, 48 and 72 h to study basal toxicity effects (cell proliferation by quantification of total protein content (PR) and relative neutral red uptake (RNRU) by lysosomes). The following biochemical indicators assessed in the in vitro test system were: cytosolic phosphofructokinase (PFK) and enolase (ENL) activities in glycolysis; mitochondrial succinate dehydrogenase (SDH) activity in the citric acid cycle; lysosomal beta-galactosidase (GAL) activity; and neuronal acetylcholinesterase (AChE) activity.

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1. The described analytical procedure permits the simultaneous determination of the main n-hexane metabolites in urine. 2-Hexanone, 2-hexanol, 2, 5-hexanediol and 2, 5-hexanedione, were chosen to dose the rats used in this study.

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The toxicity of iron (II) and iron (III) chlorides was studied at different biochemical and cellular levels, including antioxidative and metabolic enzymes and two general indicators of cytotoxicity in Vero monkey kidney cells after 24-h exposure. Iron (II) was fourfold more toxic than Fe (III) in cell proliferation, with EC50 of 5.5 and 22 mM, respectively.

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Organic solvents that are metabolically transformable into gamma-diketones produce central- peripheral distal axonopathy. One of the mechanisms proposed to explain the development of this neuropathy has been the formation of pyrrole adducts between gamma-diketone metabolites and -amine groups of lysine residues on the neuronal cytoskeletal proteins. In vivo studies on the neurotoxic capability of different solvents, derivatives of n-hexane and n-heptane, have previously established the quantitative structure-activity sequence.

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Different cellular and biochemical cytotoxicity indicators have been assessed to evaluate the damages caused in Vero monkey kidney fibroblasts after 24 h exposure to paraquat (PQ), a widely used bipyridyl herbicide highly toxic through the active oxygen species that it generates by redox cycling. Cell viability, estimated by the relative neutral red uptake (EC50 = 0.5 mM), was more sensitive to PQ than cell proliferation, measured by total protein content (EC50 = 5 mM).

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We report the pathologic changes of the cardiac conduction tissue (CS) in 33 cases of sudden cardiac death. The cases were divided into two groups: those with severe atherosclerotic coronary lesion (> 75% cross-sectional area stenosis of at least one coronary artery), 15 cases, and those without significant coronary disease, 18 cases. In the first group, we observed major changes of the CS in eight cases.

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To compare the effects of cobalt at different cellular levels, cultured mouse neuroblastoma cells (Neuro-2a) were exposed for 24 hr to cobalt(II) chloride. The following toxicity indicators were assessed: cell proliferation by quantification of total protein content; cytoplasmic membrane integrity to cytosolic lactate dehydrogenase leakage; lysosomal hexosaminidase release; lactate dehydrogenase activity (LDH); mitochondrial succinate dehydrogenase activity (SDH); relative neutral red uptake by lysosomes (RNRU); lysosomal hexosaminidase activity (HEX), and acetylcholinesterase activity (AChE). The effect of cobalt on the various indicators differed.

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The toxic effects of arsenic at different cellular levels were assessed using two inorganic chemical species: sodium arsenite and sodium arsenate, representing the trivalent and pentavalent states of arsenic, respectively. Mouse neuroblastoma cell cultures (Neuro-2a) were exposed for 24 h, and cytotoxic effects evaluated were: cell proliferation by quantification of total protein content; cytoplasmic membrane integrity to cytosolic lactate dehydrogenase leakage; lysosomal hexosaminidase release; lactate dehydrogenase activity; mitochondrial succinate dehydrogenase activity; relative neutral red uptake by lysosomes; lysosomal hexosaminidase sphingolipid degradation activity; and acetylcholinesterase activity. As(III) was found to be five times more toxic than As(V) to neuroblastoma cell proliferation, but the relative extent of other alterations differed.

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To compare the effects of thallium at different cellular levels, cultured mouse neuroblastoma cells (Neuro-2A) were exposed for 24 hr to thallium(I) acetate. The following toxic indicators were assessed in the in vitro test system: cell proliferation by quantification of total protein content of the culture; cytoplasmic membrane integrity to cytosolic lactate dehydrogenase (LDH) leakage; lysosomal hexosaminidase release; lactate dehydrogenase activity; mitochondrial succinate dehydrogenase activity; relative neutral red uptake by lysosomes; lysosomal hexosaminidase sphingolipid degradation activity; acetylcholinesterase activity. The effects of thallium on the various indicators differed.

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An in vitro model system has been developed to establish dose-response relationships of mercuric chloride (HgCl(2)) and methylmercuric chloride (HgCH(3)Cl). Mouse neuroblastoma cell cultures (Neuro-2a) were exposed for 24 hr and cytotoxic effects evaluated with eight different endpoints. Toxic indicators assessed in the in vitro test system were as follows: cell proliferation by quantification of total protein content; cytoplasmic membrane integrity by cytosolic lactate dehydrogenase leakage; lysosomal membrane stability by hexosaminidase release; lactate dehydrogenase activity; mitochondrial succinate dehydrogenase activity; relative neutral red uptake by lysosomes; lysosomal hexosaminidase sphingolipid degradation activity; acetylcholinesterase activity.

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Intestinal ischemia induced by cocaine abuse is a rare condition. To this date, only three cases have been described. The diagnosis of bowel ischemia should be suspected whenever a cocaine addict has severe abdominal pain.

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The polymorphism of alpha-1-antitrypsin (PI) has been studied by hybrid isoelectric focusing in miniaturized immobilized pH gradient gels, with an interelectrode distance of 55 mm, in two narrow ranges of pH 4.35-4.75 and 4.

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The identification of group specific component (Gc) subtypes derived from blood-stains by separator isoelectric focusing in micro-ultrathin polyacrylamide gels (interelectrode distance: 50 mm) containing 4.5 to 5.4 pharmalytes is described.

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The identification of phenotypes of erythrocyte acid phosphatase (EAP), esterase D (EsD), group specific component (Gc), and alpha-1-antitrypsin (PI) by separator isoelectric focusing in micro-ultrathin polyacrylamide gels (interelectrode distance: 45 mm) is described. The protein patterns obtained are compared favorably with the patterns seen by isoelectric focusing in conventional polyacrylamide gel dimensions (interelectrode distance: 110 to 120 mm). The technique described allows greater stability of pH gradients and is a fast and economic method.

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