Validated GC/MS method for the simultaneous determination of clozapine and norclozapine in human plasma. Application in psychiatric patients under clozapine treatment.

A sensitive and specific GC/MS method for the determination of clozapine (CLZ) and its major metabolite norclozapine (NCLZ), in plasma has been developed, optimized and validated. Specimen preparation includes solid-phase extraction of both analytes using Bond-Elut Certify cartridge and further derivatization with TFAA. Clozapine-d8 was used as internal standard for the determination of CLZ and NCLZ. Limits of detection were 0.45 ng/mL for CLZ and 1.59 ng/mL for NCLZ, while limits of quantification were 1.37 ng/mL for CLZ and 4.8 ng/mL for NCLZ, as calculated by the calibration curves. The calibration curves were linear up to 600 ng/mL for CLZ and NCLZ. Absolute recovery ranged from 82.22% to 95.35% for both analytes. Intra- and interday accuracy was less than 7.13% and --12.52%, respectively, while intra- and interday precision was between 9.47% and 12.07%, respectively, for CLZ and NCLZ. The method covers all therapeutic range and proved suitable for the determination of CLZ and NCLZ not only in psychiatric patients but also in forensic cases with clozapine implication.

Fundamental issues in forensic semen detection / Problemas fundamentales en la detección forense de semen

Sperm detection can be an important factor in confirming sexual assault in cases of rape. A large number of cases received in a forensic laboratory involve sexual offenses, making it necessary to examine exhibits for the presence of seminal stains. The objective of this paper is to provide an overview of the most important methods and tests used in the identification of spermatozoa or constituents ofseminal fluid during the investigation ofalleged sexual assault cases in forensic medical practice. Furthermore, this paper focusses on the basic knowledge that is necessary to the graduate students who wish to specialize in forensic sciences.

La detección de esperma puede ser un factor importante a la hora de confirmar un ataque sexual en los casos de violación. Un gran número de los casos recibidos en el laboratorio forense tienen relación con ofensas sexuales, lo cual hace necesario examinar muestras de presencia de manchas seminales. El objetivo de este trabajo es proporcionar una apreciación global de los métodos y pruebas más importantes usados en la identificación de espermatozoos o constituyentes del fluido seminal durante la investigación de supuestos casos de ataque sexual, en la práctica médica forense. Además, este trabajo presta atención al conocimiento básico necesario para los estudiantes graduados que desean especializarse en las ciencias forenses.

Fundamental issues in forensic semen detection.

Sperm detection can be an important factor in confirming sexual assault in cases of rape. A large number of cases received in a forensic laboratory involve sexual offenses, making it necessary to examine exhibits for the presence of seminal stains. The objective of this paper is to provide an overview of the most important methods and tests used in the identification of spermatozoa or constituents of seminal fluid during the investigation of alleged sexual assault cases in forensic medical practice. Furthermore, this paper focusses on the basic knowledge that is necessary to the graduate students who wish to specialize in forensic sciences.

Assessing food additive toxicity using a cell model.

Food additives are widely used for technological purposes and their presence is often substantial daily diet. They have also been accused forvarious toxic reactions in humans. The toxicity of the food color tartrazine, the preservatives sodium nitrate and sodium benzoate, and the antioxidant BHT, was studied using the protozoan Tetrahymenapyriformis as a toxicological model. The 4 food additives were added to Tetrahymena cultures and DNA content of the protozoan nuclei measured by an image analysis system. These food additives caused a statistically significant increase in DNA content suggesting stimulation of the mitotic process. This system may contribute to the investigation of the cellular action of food additives, since mitogenic stimuli substantially alter susceptibility to chemical carcinogenesis.

Lead content of fresh milk samples from different sites in Athens.

Milk and dairy products constitute a major food, especially for infants and children, and relatively low levels of toxic elements can contribute significantly to dietary intakes and be hazardous for public health. The purpose of this survey was to define the levels of lead in milk samples of different origin, to establish the presence or absence of contamination. The milks from different sites of the metropolitan area of Athens contained negligible traces of lead and thus are safe for the public health.

Delat9-tetrahydrocannabinol content in cannabis plants of greek origin.

The delta9-tetrahydrocannabinol (delta9-THC) content was identified and determined quantitatively using a Gas Chromatography Detector (Gas Chromatography-Electron Ion Detector) instrument in samples of illicit herbal cannabis. Law enforcement authorities sent the samples to the Department of Forensic Medicine and Toxicology, University of Athens, for toxicological analysis. The concentrations of delta9-THC in these samples ranged from 0.08% to 4.41%. Such concentrations suggest that Greece might be at high risk, as an area for the illicit cultivation of "pedigree" cannabis plants. The forensic aspects of cannabis classification are discussed.

Phagocytosis of the protozoon Tetrahymena pyriformis as an endpoint in the estimation of cocaine salt and cocaine freebase toxicity.

Cells of the ciliated protozoon Tetrahymena pyriformis strain W, grown in a peptone-yeast medium, usually contain many phagocytic vacuoles. The phagocytic activity of this protozoon was studied in vivo using heat-inactivated yeast stained with carmine after exposing the cultures for 1 hour to different doses of cocaine hydrochloride or cocaine freebase (crack) (0.5, 1 or 2 mg/100 ml of protozoan culture).The number of vacuoles formed indicated the phagocytic activity. Cocaine hydrochloride and crack caused a decrease of the phagocytic activity of the protozoon (p < 0.05) when compared to the control cultures. Furthermore, the two chemical forms of cocaine, salt and free-base respectively, caused quantitatively different effects on the phagocytic activity. Crack produced an extensive decrease in phagocytosis, compared to equal concentrations of cocaine hydrochloride. These results suggest a possible relationship between cocaine abuse and the suppression of phagocytosis that may contribute to the impairment of immunity in drug misusers.

Bee pseudocholinesterase as an indicator of exposure to anticholinesterase insecticides.

The inhibition of pseudocholinesterase (butyrylcholinesterase) activity is a valid and sensitive biochemical indicator of exposure to anticholinesterase insecticides and is often mandatory of the agricultural use of these pesticides. In the present work we developed a modification of an easy and sensitive technique to detect the pseudocholinesterase inhibition due to pesticide exposure. Small amounts of head tissue are needed and low concentrations of the enzyme can be detected. The determination of pseudocholinesterase inhibition is a useful biomonitor of anticholinesterase pesticide exposure for bees in the same way that it is useful for the determination of exposure in humans.

Lead exposure of the child population in Greece.

Lead exposure of the child population was studied in three different areas in Greece: Kalamata which is a rural area of Southern Greece; Tavros, a district of Athens with a considerable industrial activity; and Lavrion, a small city near Athens where a lead-zinc mining and smelting industrial complex has existed for more than 90 years. The results were evaluated with respect to a number of individual, social and environmental variables (i.e. smelter, occupation of the father) especially those concerning the area of Lavrion which is the most heavily polluted area in Greece. The results of this study can be considered as an index for the extent of the lead pollution problem in the named areas of Greece.

["Palatolaryngeal hemiplegia" in transient brain stem ischemia--a contribution to neurogenic dysphagia]. / "Patatolaryngeale Hemiplegie" bei passagerer Hirnstammischämie--Ein Beitrag zur neurogenen Dysphagie.

A 65-year old man suffering from dysphagia with aspiration was examined. ENT examination showed a Horner syndrome and cranial nerve palsy with paralysis of the soft palate and one vocal cord (palatolaryngeal hemiplegia, Avellis' syndrome). Pharyngeal manometry and videofluoroscopy depicted an asynergic swallowing with cricopharyngeal achalasia. CT scans of mediastinum, head, neck, and skull base showed no signs of abnormality. MR imaging of the brain stem demonstrated an enrichment of contrast medium in the dorsal region of the upper medulla oblongata in the level of the centre of the glossopharyngeal and vagus nerve. This case demonstrates an uncommon cause of dysphagia which was related to transitory brain stem ischaemia. After a period of three weeks the patients' complaints vanished as well as the clinical features. In a follow-up of MR-imaging three months later no focal enhancement of contrast medium was seen confirming the diagnosis of a brain stem ischaemic lesion.

A simple method for the estimation of paraquat in tissue.

A short and simple method is described for the determination of paraquat in viscera in cases of fatal intoxication. Paraquat, which can dialyse through a cellulose semipermeable membrane into an aqueous media, was measured spectrophotometrically.