Validation of Large White Pig as an animal model for the study of cannabinoids metabolism: application to the study of THC distribution in tissues

This study presents a new animal model, the Large White Pig, which was tested for studying cannabinoids metabolism. The first step has focused on determination of plasma kinetics after injection of Delta(9)-tetrahydrocannabinol (THC) at different dosages. Seven pigs received THC by intravenous injections (50, 100 or 200 microg/kg). Plasma samples were collected during 48 h. Determination of cannabinoids concentrations were performed by gas chromatography/mass spectrometry. Results showed that plasma kinetics were comparable to those reported in humans. Terminal half-life of elimination was 10.6 h and a volume of distribution of 32 l/kg was calculated. In a second step, this model was used to determine the kinetic profile of cannabinoids distribution in tissues. Eight Large White male pigs received an injection of THC (200 microg/kg). Two pigs were sacrificed 30 min after injection, two others after 2, 6 and 24 h. Different tissues were sampled: liver, kidney, heart, lung, spleen, muscle, fat, bile, blood, vitreous humor and several brain areas. The fastest THC elimination was noted in liver tissue, where it was completely eliminated in 6 h. THC concentrations decreased in brain tissue slower than in blood. The slowest THC elimination was observed for fat tissue, where the molecule was still present at significant concentrations 24 h later. After 30 min, THC concentration in different brain areas was highest in the cerebellum and lowest in the medulla oblongata. THC elimination kinetics noted in kidney, heart, spleen, muscle and lung were comparable with those observed in blood. 11-Hydroxy-THC was only found at high levels in liver. THC-COOH was less than 5 ng/g in most tissues, except in bile, where it increased for 24 h following THC injection. This study confirms, even after a unique administration, the prolonged retention of THC in brain and particularly in fat, which could be at the origin of different phenomena observed for heavy users such as prolonged detection of THC-COOH in urine or cannabis-related flashbacks. Moreover, these results support the interest for this animal model, which could be used in further studies of distribution of cannabinoids in tissues.     

Analysis of artificially degraded DNA using STRs and SNPs--results of a collaborative European (EDNAP) exercise

Recently, there has been much debate about what kinds of genetic markers should be implemented as new core loci that constitute national DNA databases. The choices lie between conventional STRs, ranging in size from 100 to 450 bp; mini-STRs, with amplicon sizes less than 200 bp; and single nucleotide polymorphisms (SNPs). There is general agreement by the European DNA Profiling Group (EDNAP) and the European Network of Forensic Science Institutes (ENFSI) that the reason to implement new markers is to increase the chance of amplifying highly degraded DNA rather than to increase the discriminating power of the current techniques. A collaborative study between nine European and US laboratories was organised under the auspices of EDNAP. Each laboratory was supplied with a SNP multiplex kit (Foren-SNPs) provided by the Forensic Science Service, two mini-STR kits provided by the National Institute of Standards and Technology (NIST) and a set of degraded DNA stains (blood and saliva). Laboratories tested all three multiplex kits, along with their own existing DNA profiling technique, on the same sets of degraded samples. Results were collated and analysed and, in general, mini-STR systems were shown to be the most effective. Accordingly, the EDNAP and ENFSI working groups have recommended that existing STR loci are reengineered to provide smaller amplicons, and the adoption of three new European core loci has been agreed.     

Multiplex PCR and minisequencing of SNPs--a model with 35 Y chromosome SNPs

We have developed a robust single nucleotide polymorphism (SNPs) typing assay with co-amplification of 25 DNA-fragments and the detection of 35 human Y chromosome SNPs. The sizes of the PCR products ranged from 79 to 186 base pairs. PCR primers were designed to have a theoretical Tm of 60 +/- 5 degrees C at a salt concentration of 180 mM. The sizes of the primers ranged from 19 to 34 nucleotides. The concentration of amplification primers was adjusted to obtain balanced amounts of PCR products in 8mM MgCl2. For routine purposes, 1 ng of genomic DNA was amplified and the lower limit was approximately 100 pg DNA. The minisequencing reactions were performed simultaneously for all 35 SNPs with fluorescently labelled dideoxynucleotides. The size of the minisequencing primers ranged from 19 to 106 nucleotides. The minisequencing reactions were analysed by capillary electrophoresis and multicolour fluorescence detection. Female DNA did not influence the results of Y chromosome SNP typing when added in concentrations more than 300 times the concentrations of male DNA. The frequencies of the 35 SNPs were determined in 194 male Danes. The gene diversity of the SNPs ranged from 0.01 to 0.5.     

Brief Research Report: Age Factors Affecting the Believability of Repressed Memories of Child Sexual Assault

Two experiments investigated how mock jurors react to testimony involving claims of a repressed memory in a case involving child sexual assault. Participants read a fictional civil trial summary presented in one of three conditions: (a) immediate condition—the alleged victim testified immediately after the incident; (b) repressed condition—the alleged victim reported the assault 1–39 years later, after remembering it for the first time; or (c) not-repressed condition—the alleged victim reported the assault 1–39 years later, but the memory of the assault had been present for those years. When there was any type of delayed reporting, either the age of the alleged victim at the time of the assault was constant and her age at reporting varied (Experiment 1) or the age of the alleged victim at the time of the assault varied and her age at reporting remained constant (Experiment 2). The results showed that (1) a delay in reporting an incident adversely affected believability of the alleged victim and led to fewer rulings in support of the plaintiff compared to reporting it immediately, (2) longer delays in reporting generally led to lower alleged victim believability and fewer decisions in support of the plaintiff than shorter delays, (3) the age of the alleged victim at the time of the incident was a critical variable in determining belief of the alleged victim, and (4) men generally rated believability of the alleged victim lower and ruled in favor of the plaintiff less often than women. The results are discussed in terms of the psychosocial factors affecting the perception of delayed reporting in a child sexual assault trial.     

The effects of tone,focus, and incivility in election debates

Previous research has found mixed evidence for the effectiveness of negative campaigning. Therefore, scholars have recently turned their attention to the question whether there are different dimensions of negativity. The present study contributes both empirically and methodologically to this debate by investigating the effects of three German chancellor debates using real-time response measurements of audience reactions. Following Brooks and Geer (2007. “Beyond Negativity: The Effects of Incivility on the Electorate.” American Journal of Political Science 51 (1): 1–16. doi:10.1111/j.1540-5907.2007.00233.x), we distinguish between debate statements along three different dimensions: negative versus positive tone, policy- versus person-focus, and civility versus incivility. Also, we demonstrate how debate content and real-time response measurements of audience reactions can be analysed using econometric time-series techniques. Our analyses show that civil policy-focused statements have a positive impact, as expected, while person-focused or uncivil statements rarely have positive effects. In the concluding section, the implications of our findings are discussed and directions for further research identified.