Time-resolved hair analysis of MDMA enantiomers by GC/MS-NCI

The aim of the study was to determine the enantioselective disposition of 3,4-methylenedioxymethamphetamine (MDMA) and other amphetamine-type stimulants (ATS) in segmented hair specimens of self-declared ecstasy abusers, who took part in a double-blind placebo-controlled six-way crossover study during approximately 7 weeks, during which they received a 75 and a 100 mg dose of racemic MDMA twice. Hair specimens were washed and cut into pieces of 2 cm length. After digestion and solid phase extraction, the enantiomers were derivatized with a chiral agent (2S,4R)-N-heptafluorobutyryl-4-heptafluorobutoyloxy-prolyl chloride, developed at the authors laboratory and quantified by gas chromatography coupled to mass spectrometry operating in the negative chemical ionization mode. Most of the hair specimens that were tested positive for MDMA showed a predominance of the (R)-enantiomer. The R/S ratios of MDMA varied between 1.02 and 2.75 and total concentrations ranged from 0.1 to 20.1 ng/mg. The enantiomers of its metabolite 3,4-methylenedioxyamphetamine (MDA) were also quantified in most hair segments. The R/S ratios of MDA varied between 0.60 and 1.60, while the concentrations of the enantiomers ranged from 10 to 160 pg/mg hair. When segmental analysis was performed on single hair specimens, no inversion of the R versus S ratios of MDMA and MDA was observed. The predominance of (R)-MDMA in hair was in accordance with those already published for other matrices. Furthermore, both enantiomers of amphetamine (AM) were also detected in hair segments of four volunteers and the R/S ratios ranged from 1.00 to 1.47.     

Y-chromosomal STR haplotypes in a population from the Amazon region, Brazil

Haplotype and allele frequencies of the nine Y-STR (DYS19, DYS389 I, DYS389 II, DYS390, DYS391, DYS392, DYS393, DYS385 I/II) were determined in a population sample of 200 unrelated males from Belém, Brazil. The most common haplotypes are shared by 1.5% of the sample, while 186 haplotypes are unique. The haplotype diversity is 0.9995+/-0.0006. The data obtained were compared to those of other Brazilian populations. AMOVA indicates that 99.91% of all the haplotypical variation is found within geopolitical regions and only 0.09% is found among regions.     

Cyberbullying in Portuguese Schools: Prevalence and Characteristics

This study examined the extent and nature of cyberbullying in 23 Portuguese schools. A sample of 3,525 sixth-, eighth-, and eleventh-grade students completed a self-response questionnaire assessing their perceptions and experiences of cyberbullying. The findings showed that 7.6% of students have been victimized, and 3.9% have bullied others at least once over the last year. The incidences of victimization were higher for females and for the older students. In contrast, more boys reported having bullied others in the eleventh grade. The most frequent medium of cyberbullying was via websites, whilst sending offensive messages was the most widely reported type of behavior. Telling someone about cyberbullying is among the most frequent coping strategies used by cybervictims, who usually chose to tell their friends rather than adults. Implications of these findings for students, schools, and parents are discussed.     

Application of mesocellular siliceous foams (MCF) for surface-assisted laser desorption ionization mass spectrometry (SALDI-MS) Analysis of fingermarks

Recent advances in nanotechnology applied in forensic sciences have contributed to consider new approaches including chemical evaluation of latent fingermarks. Significant improvement to the detection of small organic molecules has been reached with matrix-free methods associated to laser desorption/ionization mass spectrometry. The present study investigated the application of mesocellular siliceous foam (MCF) as an ionizing agent for laser desorption/ionization (LDI-MS) analysis of fingermarks as a proof of concept research. Fingermarks from three different donors were deposited directly onto a MALDI target plate and α-CHCA matrix solution, MCF ethanolic suspension or MCF/magnetic powder mixture were used for treatment. Microscopy characterization of MCF support showed particles with irregular morphology and variable sizes, and a unordered porous surface with pores diameter ranging from about 10 to 20?nm. Results showed less intense peaks in the spectra produced by the MCF support (control). Analysis of fingermarks showed ions related to endogenous and exogenous molecular components, including possible lipids from human sebum and quaternary ammonium cations commonly present in cosmetics. Promising and reproducible results were obtained for the fingermarks dusted with the MCF/magnetic powder mixture. Considering the forensic applications of nanomaterials for the analysis of small molecules in biological samples by matrix-free LDI techniques, the advantages of silica based materials should be further investigated.     

Allele frequencies of six miniSTR loci in the population of Northern Portugal

A possible approach to try to recover information from degraded DNA is to reduce the size of the PCR products by designing primers that bind as close as possible to the STR repeat region, known as miniSTRs. Allele frequencies and forensic parameters for the six miniSTRs loci D1S1677, D2S441, D4S2364, D10S1248, D14S1434 and D22S1045 were investigated in a sample group consisting of 228 anonymous apparently healthy unrelated individuals living in North of Portugal. The results show that all loci were in Hardy–Weinberg equilibrium. The combined power of discrimination and power of exclusion for the six loci were 0.99999 and 0.9789, respectively. All but one (D4S2364) loci showed a moderate degree of polymorphism (observed heterozygosity >0.6). The allele sizes ranged between 66 and 118 bp in our population, which is beneficial for typing degraded samples than those of a commercial STR kit.     

Influence of bleaching on the enantiomeric disposition of amphetamine-type stimulants in hair

The aim of this work was to study the influence of hair bleaching on the enantiomeric ratios of amphetamine-type stimulants (ATS), including amphetamine, methamphetamine, 3,4-methylenedioxyamphetamine, 3,4-methylenedioxymethamphetamine and 3,4-methylenedioxyethylamphetamine. Hair specimens from 14 STA users were treated with a commercial bleaching product during 40 min. After alkaline digestion and solid-phase extraction of bleached and non-bleached hair, the STA enantiomers were derivatised with an in-house synthesised chiral reagent, the (2S,4R)-N-heptafluorobutyryl-4-heptafluorobutoyloxy-prolyl chloride. The diastereoisomers were quantified by GC/MS-NCI. The results showed that the concentrations of all enantiomers decreased in bleached hair in comparison with the non-treated hair (median values between 20 and 39%). The enantiomeric ratios of the STA in bleached hair were not significantly different from those determined in non-treated hair. Our findings pointed out that bleaching treatments decrease concentrations of STA in hair without influencing their enantiomeric ratios.