Evaluation of the IDS One-Step ELISA kits for the detection of illicit drugs in hair

This work presents the validation of a new immunological assay, the One-Step enzyme-linked immunosorbent assay (ELISA) tests from International Diagnostic Systems Corp. for the screening of drugs of abuse (cannabis, amphetamines, opiates, and cocaine) in human hair, with subsequent GC-MS confirmation. After decontamination and segmentation into small pieces, 50 mg of hair sample were incubated in 1 ml of methanol during 16 h at 40 degrees C. A 100 microL aliquot was collected and evaporated to dryness in presence of 100 microL of methanol/hydrochloric acid (99:1, v/v) to avoid amphetamines loss. The dried extract was dissolved in 100 microL of the "sample and standard diluent" solution included in the kit. This solution was submitted to analysis according to the recommended instructions of the manufacturer. During the validation phase, GC-MS confirmations were conducted according to our fully validated and published methods for opiates, cocaine, cannabis, and amphetamines determinations in hair. In a last development step, these procedures were slightly modified to directly confirm ELISA results by GC-MS using the methanolic extract. Ninety-three specimens were simultaneously screened by the ELISA tests (103 for tetrahydrocannabinol (THC)) and confirmed by GC-MS. Twenty were found positive for cannabis (THC: 0.10-6.50 ng/mg), 21 for cocaine (0.50-55.20 ng/mg), 24 for opiates (6-acetylmorphine (6-AM): 0.20-11.60 ng/mg, MOR: 0.20-8.90 ng/mg, codeine (COD): 0.20-5.90 ng/mg), and 13 for amphetamines (AP: 0.20 and 0.27 ng/mg, methamphetamine (MAP): 0.30 and 1.10 ng/mg, methylenedioxymethamphetamine (MDMA): 0.22-17.80 ng/mg). No false negative results were observed according to the Society of Hair Testing's (SoHT) cutoffs (0.5 ng/mg for cocaine, 0.2 ng/mg for opiates and amphetamines, and 0.1 ng/mg for THC). The One-Step ELISA kits appear suitable due to their sensitivity and specificity for drug of abuse screening in hair. This technology should find interest in workplace drug testing or driving license regranting, especially when many samples have to be tested with a high rate of negative samples, as ELISA is an easy and high-throughput method.     

Hair analysis for diphenhydramine after surreptitious administration to a child

Diphenhydramine is one of the first effective antihistamine agents to have been discovered. The compound is also used for its sedative and antiemetic effects. The first case involving repetitive sedation linked to the use of diphenhydramine as a drug-facilitated crime and subsequent impairment of a 9-year-old female victim is reported. Due to the long delay between the alleged crime and clinical examination, collection of blood or urine was of little value. Hence, the laboratory developed an original approach based on hair testing by LC-MS/MS. A single strand of hair from the victim was sampled about 7 weeks after the last suspected administration and was cut into small segments. After cutting into small pieces, about 20 mg of hair per segment was incubated overnight in a phosphate buffer (pH 8.4). The aqueous phase was extracted with 5 ml of a mixture of methylene chloride/diethyl ether (80/20), in presence of diazepam-d5, used as internal standard (IS). The hair extract was separated on an XTerra MS C18 column using a gradient of acetonitrile and formate buffer. Detection was based on two daughter ions: transitions m/z 256.2-152.1 and 167.1 and m/z 289.9-154.0 for diphenhydramine and the IS, respectively. In the hair of the child, diphenhydramine was detected at concentrations in the range 33-39 pg/mg, depending on the segment.     

Analysis of body fluid mixtures by mtDNA sequencing: An inter-laboratory study of the GEP-ISFG working group

The mitochondrial DNA (mtDNA) working group of the GEP-ISFG (Spanish and Portuguese Group of the International Society for Forensic Genetics) carried out an inter-laboratory exercise consisting of the analysis of mtDNA sequencing patterns in mixed stains (saliva/semen and blood/semen). Mixtures were prepared with saliva or blood from a female donor and three different semen dilutions (pure, 1:10 and 1:20) in order to simulate forensic casework. All labs extracted the DNA by preferential lysis and amplified and sequenced the first mtDNA hypervariable region (HVS-I). Autosomal and Y-STR markers were also analysed in order to compare nuclear and mitochondrial results from the same DNA extracts. A mixed stain prepared using semen from a vasectomized individual was also analysed. The results were reasonably consistent among labs for the first fractions but not for the second ones, for which some laboratories reported contamination problems. In the first fractions, both the female and male haplotypes were generally detected in those samples prepared with undiluted semen. In contrast, most of the mixtures prepared with diluted semen only yielded the female haplotype, suggesting that the mtDNA copy number per cell is smaller in semen than in saliva or blood. Although the detection level of the male component decreased in accordance with the degree of semen dilution, it was found that the loss of signal was not consistently uniform throughout each electropherogram. Moreover, differences between mixtures prepared from different donors and different body fluids were also observed. We conclude that the particular characteristics of each mixed stain can deeply influence the interpretation of the mtDNA evidence in forensic mixtures (leading in some cases to false exclusions). In this sense, the implementation of preliminary tests with the aim of identifying the fluids involved in the mixture is an essential tool. In addition, in order to prevent incorrect conclusions in the interpretation of electropherograms we strongly recommend: (i) the use of additional sequencing primers to confirm the sequencing results and (ii) interpreting the results to the light of the phylogenetic perspective.     

Justice at risk! An evaluation of a pseudoscientific analysis of a witness’ nonverbal behavior in the courtroom

Psychology and law have developed as disciplines through rigorous data collection, exploration and analysis, and the publication of findings through peer-review processes. Such findings are then used to implement evidence-based practices within a variety of settings. However, in parallel to factually and scientifically based knowledge, ‘alternative’ science, or pseudoscience, has gained in popularity. The present case study aims to evaluate the empirical evidence and theoretical underpinnings of a publically accessible analysis of a suspected serial killer’s nonverbal behavior during a bond hearing published online by two ‘synergologists’. The case study emphasizes how a ‘synergological’ analysis to understanding and interpreting human behavior fails to use empirical data, making generalized inferences based on erroneous assumptions. The case study also highlights the detrimental effects such assumptions may have within the justice system and why pseudoscientific analytical approaches should be vigorously challenged by research scientists.     

Assessment of assertion and problem-solving skills in wife abusers and their spouses

The present study provided an assessment of assertion and problem solving skills in couples characterized by wife abuse. A role play test and problem solving interaction task were administered to couples who were (a) physically abusive, (b) maritally discordant but nonviolent, and (c) satisfactorily married. Results indicated that members of abusive dyads exhibited deficits on selected behavioral components of assertion. However, few differences were observed between these dyads and the maritally discordant, nonviolent condition. Findings are discussed in terms of (1) the need for further evaluation of interpersonal skill variables in physically abusive males, (2) issues in selection of measures and subjects, and (3) the need to consider the possible interactive effects of multiple factors in family violence research.