Neurotoxicity of anhydroecgonine methyl ester, a crack cocaine pyrolysis product.

Smoking crack cocaine involves the inhalation of cocaine and its pyrolysis product, anhydroecgonine methyl ester (AEME). Although there is evidence that cocaine is neurotoxic, the neurotoxicity of AEME has never been evaluated. AEME seems to have cholinergic agonist properties in the cardiovascular system; however, there are no reports on its effects in the central nervous system. The aim of this study was to investigate the neurotoxicity of AEME and its possible cholinergic effects in rat primary hippocampal cell cultures that were exposed to different concentrations of AEME, cocaine, and a cocaine-AEME combination. We also evaluated the involvement of muscarinic cholinergic receptors in the neuronal death induced by these treatments using concomitant incubation of the cells with atropine. Neuronal injury was assessed using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and lactate dehydrogenase (LDH) assays. The results of the viability assays showed that AEME is a neurotoxic agent that has greater neurotoxic potential than cocaine after 24 and 48 h of exposure. We also showed that incubation for 48 h with a combination of both compounds in equipotent concentrations had an additive neurotoxic effect. Although both substances decreased cell viability in the MTT assay, only cocaine increased LDH release. Caspase-3 activity was increased after 3 and 6 h of incubation with 1mM cocaine and after 6 h of 0.1 and 1.0mM AEME exposure. Atropine prevented the AEME-induced neurotoxicity, which suggests that muscarinic cholinergic receptors are involved in AEME's effects. In addition, binding experiments confirmed that AEME has an affinity for muscarinic cholinergic receptors. Nevertheless, atropine was not able to prevent the neurotoxicity produced by cocaine and the cocaine-AEME combination, suggesting that these treatments activated other neuronal death pathways. Our results suggest a higher risk for neurotoxicity after smoking crack cocaine than after cocaine use alone.

Identification of gunshot residues in fabric targets using sector field inductively coupled plasma mass spectrometry technique and ternary graphs.

During criminal investigations involving firearms, the detection of gunshot residues (GSRs) is one of the most important evidences. In the present study, a new method to identify trace evidences of GSRs, deposited around the bullet entrance hole, in different types of fabrics used as targets, is described. The experiments were carried out using a 0.38-inch caliber revolver, and 9-mm and 0.40-inch caliber pistols. Testimonies of 2.25 cm(2) of the fabrics were cut around the bullet entrance and digested with 10% nitric acid. Antimony, barium, and lead were analyzed in the remaining solution using a sector field inductively coupled plasma mass spectrometer. The concentrations of the elements were detected at levels up to few microgram per square centimeter. The use of ternary graphics allowed us to identify specific patterns of distribution for blank samples and the clear distinction between the revolver and pistols used.

Chemical identification of 2,5-dimethoxy-4-bromoamphetamine (DOB).

The consumption of synthetic drugs, generally known as designer drugs, has increased drastically in all parts of the world. Typical constituents of designer synthetic drugs are chemical substances derived from amphetamine but significant differences in effects caused and duration may result. In May, 2005, the civil state police of Sao Paulo seized thirty-one gelatinous capsules containing a very small quantity of a white powder inside (approximately 1.5 mg per capsule). This paper describes the analytical assays that were used to identify the seized material. Preliminary assays using colorimetric tests and high performance thin-layer chromatography indicated that the capsules content could be an amphetamine derivative. In the capillary zone electrophoresis assay, it was possible to observe that the analyzed material had basic characteristics. Mass spectrometry analysis revealed that the compound had the same molecular mass as 2,5-dimethoxy-4-bromoamphetamine (DOB) and its identity was confirmed through collision-induced dissociation (CID) experiments. Finally, the comparison of infrared sample spectrum with a spectra library provided further evidence of the DOB presence in the seized material. Although a reference standard material was not available, the information gathered from the different assays allowed the conclusion that the substance was, in fact, DOB, a substance with a powerful hallucinogenic action of proscribed use in the country and which was seized and identified for the first time in Brazil.

Carbon and nitrogen stable isotopes as indicative of geographical origin of marijuana samples seized in the city of São Paulo (Brazil).

The drug trafficking is one of the most serious problems related to the Public Safety in Brazil, especially in the most populous areas of the country, as is the case of the city of São Paulo. In this work, it was developed a methodology that can help tracking the traffic routes of marijuana samples seized in the city of São Paulo, based on stable carbon and nitrogen isotopes, which are related to the climate and plant growth conditions. A model to classify the origin of unknown samples was built using linear discriminant analysis based on about 150 samples apprehended in the main producing regions of the country. Results for 76 samples seized in the city of São Paulo showed that most of them were cultivated in a humid region with the same origin as those from Mato Grosso do Sul. The provenance of 13 outliers samples from Northeast region (an important producing region) also were evaluated and some of them presented same profile of those from Mato Grosso do Sul, pointing to the existence of the traffic routes between the Northeast and Midwest region, probably as a consequence of the intensive field raids by Brazilian Federal Government since 1999.