Allelic distribution of four tetranucleotide repeat loci (D3S1358, D18S51, D19S253, and FGA) in a population from Porto (North Portugal)

Allele frequencies for four short tandem repeat loci were determined in a population sample from Porto (North Portugal), using the polymerase chain reaction (PCR), in order to investigate possible genetic differences between populations from the center and north of Portugal. After denaturing PAGE electrophoresis, nine alleles were identified for D3S1358 (n = 256), 13 alleles for D18S51 (n = 235), 10 alleles for D19S253 (n = 238), and 15 alleles for FGA (n = 181). No deviations from Hardy-Weinberg equilibrium were found. The allele frequencies observed are similar to those of the Portuguese population compared except for the D3S1358 system.     

Cathartic effect of suicide attempts not limited to depression: a short-term prospective study after deliberate self-poisoning

The cathartic effect of suicide is traditionally defined as the existence of a rapid, significant, and spontaneous decrease in the depressive symptoms of suicide attempters after the act. This study was designed to investigate short-term variations, following a suicide attempt by self-poisoning, of a number of other variables identified as suicidal risk factors: hopelessness, impulsivity, personality traits, and quality of life. Patients hospitalized less than 24 hours after a deliberate (moderate) overdose were presented with the Montgomery-Asberg Depression and Impulsivity Rating Scales, Hopelessness scale, MMPI and World Health Organization's Quality of Life questionnaire (abbreviated versions). They were also asked to complete the same scales and questionnaires 8 days after discharge. The study involved 39 patients, the average interval between initial and follow-up assessment being 13.5 days. All the scores improved significantly, with the exception of quality of life and three out of the eight personality traits. This finding emphasizes the fact that improvement is not limited to depressive symptoms and enables us to identify the relative importance of each studied variable as a risk factor for attempted suicide. The limitations of the study are discussed as well as in particular the nongeneralizability of the sample and setting.     

Population data of Galicia (NW Spain) on the new Y-STRs DYS437, DYS438, DYS439, GATA A10, GATA A7.1, GATA A7.2, GATA C4 and GATA H4

Haplotype, allele frequencies and population data of eight Y-chromosome STR loci, DYS437, DYS438, DYS439, GATA A10, GATA A7.1, GATA A7.2, GATA C4 and GATA H4, were determined from a sample of 212 unrelated male individuals from Galicia (NW of Spain).     

The 2000-2001 GEP-ISFG Collaborative Exercise on mtDNA: assessing the cause of unsuccessful mtDNA PCR amplification of hair shaft samples

We report the results of Spanish and Portuguese working group (GEP) of International Society of Forensic Genetics (ISFG) Collaborative Exercise 2001-2002 on mitochondrial DNA (mtDNA) analysis. 64 laboratories from Spain, Portugal and several Latin-American countries participated in this quality control exercise. Five samples were sent to the participating laboratories, four blood stains (M1-M4) and a sample (M5) consisting of two hair shaft fragments. M4 was non-human (Felis catus) in origin; therefore, the capacity of the labs to identify the biological source of this sample was an integral part of the exercise. Some labs detected the non-human origin of M4 by carrying out immuno-diffussion techniques using antihuman serum, whereas others identified the specific animal origin by testing the sample against a set of animal antibodies or by means of the analysis of mtDNA regions (Cyt-b, 12S, and 16S genes). The results of the other three human blood stains (M1-M3) improved in relation to the last Collaborative Exercises but those related to hairs yielded a low rate of success which clearly contrasts with previous results. As a consequence of this, some labs performed additional analysis showing that the origin of this low efficiency was not the presence of inhibitors, but the low quantity of DNA present in these specific hair samples and the degradation.As a general conclusion the results emphasize the need of external proficiency testing as part of the accreditation procedure for the labs performing mtDNA analysis in forensic casework.     

Fatal overdoses of tramadol: is benzodiazepine a risk factor of lethality?

Tramadol is a centrally acting analgesic agent used in the treatment of mild to moderate pain. It has a low affinity to opioid receptors and inhibits the reuptake of norepinephrin and serotonin producing an analgesic action by blocking nociceptive impulses in the spine. Although 21 drug-combined fatalities including tramadol have been reported, only two fatal overdoses in adults with tramadol alone have been reported to date. We report four additional lethal intoxications, assess the toxicity of tramadol, the detection method and the possible interaction with other central nervous system (CNS) depressants, particularly benzodiazepines. Similarities between tramadol and buprenorphine are discussed, and a possible cytochrome P450-based interaction between tramadol and benzodiazepine is considered. To our knowledge, this relationship has never been reported in the literature.     

Results of the GEP-ISFG collaborative study on the Y chromosome STRs GATA A10, GATA C4, GATA H4, DYS437, DYS438, DYS439, DYS460 and DYS461: population data

The Spanish and Portuguese ISFG Working Group (GEP-ISFG) carried out a collaborative exercise in order to asses the performance of two Y chromosome STR tetraplexes, which include the loci DYS461, GATA C4, DYS437 and DYS438 (GEPY I), and DYS460, GATA A10, GATA H4 and DYS439 (GEPY II). The groups that reported correct results in all the systems were also asked to analyse a population sample in order to evaluate the informative content of these STRs in different populations. A total of 1020 males out of 13 population samples from Argentina, Brazil, Costa Rica, Macao, Mozambique, Portugal and Spain were analysed for all the loci included in the present study. Haplotype and allele frequencies of these eight Y-STRs were estimated in all samples. The lowest haplotype diversity was found in the Lara (Argentina) population (95.44%) and the highest (99.90%) in Macao (China). Pairwise haplotype analysis showed the relative homogeneity of the Iberian origin samples, in accordance with what was previously found in the European populations for other Y-STR haplotypes (http://www.ystr.org). As expected, the four non-Caucasian samples, Macao (Chinese), Mozambique (Africans), Costa Rica (Africans) and Argentina (Lara, Amerindians), show highly significant Phist values in the pairwise comparisons with all the Caucasian samples.     

Sudden unexplained death among persons 1-35 years old

Sudden unexplained death (SUD) on children and young people is unusual, although the real magnitude is unknown. The clinical and physiopathological characteristics are poorly defined. The aim of this work is to analyse the epidemiological, clinical and pathological characteristics of SUD on children and young people. In this population observational study, all sudden non-violent deaths between 1 and 35 years occurred in Bizkaia (north Spain) from 1991 to 1998 were investigated, analysing those diagnosed as SUD. Pathological records, circumstances of death and autopsy findings were obtained. Out of 107 cases of sudden death (SD), 19 were SUD. The mortality rate of SUD was 0.43/100,000 persons per year. Five had pathological antecedents: syncopal episodes in three cases and tachycardia and ventricular extrasystoles one each. The initial symptom was sudden collapse (N=13). In four cases, a precipitating factor was identified (two physical exercise and two emotional stress). Six cases died during sleep. Minimal pathological findings in coronary arteries, myocardium or conduction system was found in nine cases. Heart weight increased (under interval of confidence of 95%) was present in 12 cases. In conclusion, the SUD is very infrequent in children and young people. However, it has great clinical significance because it affects people in good health and occurs without warning symptoms. Some of these cases can be due to cardiac arrhythmias. In deaths in bed there is a high frequency of SUD. In the future, it may be possible that abnormalities at a molecular level will be detected in some of the cases identified today as SUD.