Publications by authors named "Constantinos Maravelias"

Anticholinesterase pesticides are widely used, and as a result they are involved in numerous acute and even fatal poisonings. The aim of this study was the development, optimization, and validation of a simple, rapid, specific, and sensitive gas chromatography-mass spectrometry method for the determination of 11 anticholinesterase pesticides (aldicarb, azinphos methyl, carbofuran, chlorpyrifos, dialifos, diazinon, malathion, methamidophos, methidathion, methomyl, and terbufos) in blood. Only 500 μL of blood was used, and the recoveries after liquid-liquid extraction (toluene/chloroform, 4:1, v/v) were more than 65.

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Background: A large number of plants, seeds, and berries have been used for medicinal, psychotropic, or aphrodisiac purposes for a thousand years. Mandragora officinarum belongs to the family of Solanaceae and is traditionally known as an aphrodisiac and is closely associated with witchcraft.

Objectives: In this study we report a case of an accidental poisoning after ingestion of some "aphrodisiac" berries and the contribution of the toxicological analysis in the case investigation.

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Vardenafil (VDN) is one of the three commercially available phosphodiesterase type 5 inhibitors and it is mainly used in the treatment of erectile dysfunction. A sensitive and specific gas chromatography/mass spectrometry (GC/MS) method for the determination of VDN in blood has been developed and validated. Sample preparation included solid-phase extraction and derivatization with N-methyl-N-tert-butyldimethylsilyl-trifluoroacetamide (MTBSTFA) and 1% tert-butyldimethylsilylchloride (TBDMSCl).

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The effect of cocaine and crack on the ploidy status of Feulgen-stained Tetrahymena pyriformis macronuclei using computerized DNA image analysis system was tested. For this purpose, selected doses of 5, 10 and 20 μg (per mL culture) of both drugs were administered for 2, 5 and 20 h to protozoa cultures and DNA image analysis of T. pyriformis nuclei was performed.

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A sensitive and specific GC/MS method for the determination of buprenorphine (BPN) and its main metabolite nor-buprenorphine (nor-BPN) in blood has been developed, optimized and validated. Sample preparation includes solid-phase extraction of both analytes and their derivatization with acetic anhydride in pyridine. BPN-d4 was used as internal standard for the determination of both analytes.

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Benzodiazepines are used widely in daily clinical practice, due to their multiple pharmacological actions. The frequent problems associated with the wide use of benzodiazepines, as well as the multiple incidents of poisonings, led to the necessity for the development of a precise, sensitive and rapid method for the simultaneous determination of the 23 most commonly used benzodiazepines (diazepam, nordiazepam, oxazepam, bromazepam, alprazolam, lorazepam, medazepam, flurazepam, fludiazepam, tetrazepam, chlordiazepoxide, clobazam, midazolam, flunitrazepam, 7-amino-flunitrazepam, triazolam, prazepam, nimetazepam, nitrazepam, temazepam, lormetazepam, clonazepam, camazepam) in blood. A gas chromatographic method combined with mass spectrometric detection was developed, optimized and validated for the determination of the above substances.

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Background: Anticholinergic plants contain a variety of alkaloids that are toxic if ingested. Datura innoxia belongs to the family of Solanaceae and contains two main toxic alkaloids, atropine and scopolamine.

Case Series: In this study we report the case series of seven individuals who were admitted to two different hospitals of Athens with an anticholinergic syndrome.

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Methadone is used extensively for the maintenance of opioid-addicted pregnant women. Because methadone and the two major metabolites, 2-ethylidene-1,5-dimethyl-3,3-diphenylpyrrolidine (EDDP) and 2-ethyl-5-methyl-3,3-diphenylpyrroline (EMDP), are excreted into breast milk, a sensitive and specific gas chromatographic-mass spectrometric method has been developed, optimized, and validated for their quantitative determination in human breast milk. The procedure combined protein precipitation with acetonitrile and solid-phase extraction, using Isolute Confirm HCX mixed-mode SPE columns, with minimal matrix effect.

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A simple HPLC method has been validated for the determination of sildenafil and its active metabolite (N-desmethylsildenafil) in human blood, using an octadecyl silica (ODS) hypersil column. The chromatographic run time is less than 25 min using a mobile phase of 35:65 (v/v) acetonitrile-0.015 M disodium hydrogen phosphate (Na(2)HPO(4)), triethylamine 0.

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A sensitive and specific GC/MS method for the determination of methadone (MDN) and its two main metabolites, 2-ethylidene-1,5-dimethyl-3,3-diphenylpyrrolidine (EDDP) and 2-ethyl-5-methyl-3,3-diphenylpyrroline (EMDP), in plasma samples obtained from venous and arterial umbilical cord blood and maternal blood has been developed, optimized and validated. Specimen preparation includes protein precipitation with acetonitrile and simultaneous solid-phase extraction of the three analytes. Methadone-d9 was used as internal standard for the determination of MDN and EMDP, while EDDP-d3 for EDDP.

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Glutaraldehyde (GA) is a high production volume chemical that is very reactive with a wide spectrum of medical, scientific and industrial applications. Since human exposure in anthropogenic and occupational environment occurs frequently, GA has been extensively tested for genotoxic activity in vitro and in vivo. However, there are conflicting results in the literature and there is a lack of information concerning the combined effects of exposure to both GA and ionizing radiation in human cells.

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