Genetic variability of 16 Y-chromosome STRs in a sample from Equatorial Guinea (Central Africa)

Nine Y-STR loci from the "minimal haplotype" included in Y-STR Haplotype Reference Databases (YHRD) together with eight additional Y-STRs (DYS437, DYS438, DYS439, DYS460, DYS461, GATA C4, GATA H4 and GATA A10) were analyzed in a sample of 101 males from Equatorial Guinea living in Madrid. Haplotype and allelic frequencies were calculated and genetic diversities were estimated for each genetic system as well as for the whole haplotype. An unexpected high frequency (6%) of intermediate alleles (13.2 and 14.2) was found in DYS385. For DYS19, two alleles were found in one sample. Another sample failed to amplify with DYS393 primers using either PowerPlex Y System (Promega Corporation) or the Y-PLEXtrade mark 12 (Reliagene, New Orleans, LA) commercial kits. Comparison between Equatorial Guinea and another African population (Mozambique; South East Coast) revealed a significant pairwise Phi(st) value between them (Phi(st)=0.03309; P=0.00000).     

Metal and metalloid multi-elementary ICP-MS validation in whole blood, plasma, urine and hair. Reference values

Four multi-elementary metal and metalloid quantification methods using inductively coupled plasma mass spectrometry (ICP-MS) were developed and validated in human whole blood, plasma, urine and hair by means of a single preparation procedure for each sample. The ICP-MS measurements were performed using a Thermo Elemental X7CCT series and PlasmaLab software without a dynamic reaction cell. With this procedure 27-32 elements can be simultaneously quantified in biological matrices: Li, Be, B, Al, V, Cr, Mn, Co, Ni, Cu, Zn, Ga, Ge, As, Se, Rb, Sr, Mo, Pd, Ag, Cd, Sn, Sb, Te, Ba, W, Pt, Hg, Tl, Pb, Bi, U. Whole blood, plasma and urine samples (0.4 ml each) were diluted with purified water, acid, triton X100 and butanol. Rhodium was used as internal standard. The urine sample results were corrected for enzymatic creatinine determination. Twenty-five milligrams hair samples were acid mineralized after a decontamination procedure and diluted as previously described for biological fluids. To be validated, each element had to show linearity with a correlation coefficient higher than 0.99. The intra-assay and inter-assay inaccuracy, measured as the variation coefficient, were below 5 and 10% respectively. Global performance was assessed by a quality control program. Our laboratory is a registered participant of the Institut National de Santé Publique du Québec (Sainte-Foy, Canada) inter-laboratory comparison program for whole blood, urine, and beard hair of non-occupationally exposed individuals spiked with selected elements. In our study multi-element metal and metalloid analysis was assessed for 27 elements in whole blood, 27 elements in plasma, 30 elements in urine and 32 elements in hair, from 0 to 25, or 250 to 1000 ng/ml, depending on the element. Quantification limits ranged from 0.002 ng/ml (U) to 8.1 ng/ml (Al) for whole blood, from 0.002 ng/ml (U) to 7.7 ng/ml (Al) for plasma, from 0.001 ng/ml (U) to 2.2 ng/ml (Se) for urine, and from 0.2 pg/mg (Tl) to 0.5 ng/mg (B) for hair. Normal values were determined in whole blood (n=100), plasma (n=100), urine (n=100), and hair (n=45) of healthy volunteers, leading to approximately 10,000 analyses. All results are presented and discussed. Clinical toxicology and forensic toxicology applications are also reported. ICP-MS has made significant advances in the field of clinical biology, particularly in toxicological analysis. This is due to the use of extremely effective equipment that permits better clinical and forensic toxicological analysis of metal and metalloid status of each individual patient.     

Mitochondrial DNA error prophylaxis: assessing the causes of errors in the GEP'02-03 proficiency testing trial

A qualitative and quantitative analytical method was developed and validated for the determination of 49 licit and illicit drugs in oral fluid. Small oral fluid samples, volume 1mL, were collected from volunteers using a modified Omni-Sal device and the analytes were extracted from an oral fluid/buffer mixture using a single Bond Elut Certify solid phase extraction cartridge. Liquid chromatography-tandem mass spectrometry (LC-MS-MS) and gas chromatography-repetitive full scan mass spectrometry (GC-MS) were used in parallel to analyze the extracts for the targeted drugs. Extracts were analyzed by GC-MS in their underivatized form and as their pentafluoropropionyl derivatives. Deuterated internal standards were used for quantification of drugs of abuse by LC-MS-MS to minimize matrix effects. Methadone-d(9) and tumoxetine were used as the internal standards for quantification of non-derivatized and derivatized analytes respectively by GC-MS. Linearity was demonstrated over the range 5-200 ng/mL and limits of detection were less than 4 ng/mL for each drug analyzed. The method demonstrated acceptable recoveries for most of the analytes and good intra- and inter-day precision. Acquisition of data by repetitive full scan GC-MS allows the addition of further analytes to the target menu.     

A case of commingled remains from rural South Africa

In the spring of 2003, bush cutters discovered a large grain bag filled with human skeletal remains in a forest in South Africa. Differential taphonomic processes observed on the bones suggested that the individuals had not died at the same time or had decomposed under different circumstances. The remains were sorted using gross morphological techniques which included assessing the number of skeletal elements present, visual pair matching, articulation, process of elimination and taphonomy. Standard techniques were used to estimate age, sex, racial affinity and stature. A minimum number of individuals (MNI) of 10 was established, which included 7 adult males, 1 adult female and 2 juveniles. Trauma was observed on only one individual. Approximately, 80% of the skeletal remains were missing. These various skeletal elements may have been lost by accident, normal taphonomic processes or taken by scavengers. Possible origins for these skeletal remains include removal from a formal grave, found in the veldt or murdered.     

Interpretation of postmortem change in cadavers in Spain

Estimating time since death is especially difficult in the examination of poorly preserved cadavers and depends on the experience of the examiner and comparison with previously documented cases showing similar characteristics. The present study reports on information obtained over the past ten years through the work of the Laboratorio de Antropología y Odontología Forense (LAF) of the Instituto Anatómico Forense de Madrid, Spain, in particular evaluating how the type of fracture influences postmortem change. From the original 225 forensic cases examined between 1992 and 2002 in the LAF, a sample of 29 cases were selected from various regions of the Spanish mainland. A data collection protocol was established to reflect factors which the existing specialized literature, documenting the relation existing in the sample analyzed between time since death and the extent of postmortem change, which in the environments examined are distributed into the following phases: Phase 1 (putrefaction): one week to one month on the surface and two months in water. Phase 2 (initial skeletonization): two months on the surface and five to six months in water. Phase 3 (advanced skeltonization): six months to 1.5 years on the surface and 2.5 years buried. Phase 4 (complete skeletonization): about one year on the surface and three years buried. This paper also provide useful information on the impact of carrion insect activity, location, climate, seasonality, and predator.     

Nine autosomal STRs genotype profiles in a sample from Córdoba (Argentina)

Nine STRs loci have been typed in a sample from Córdoba (Argentina).     

Etiology of pulmonary thromboembolism in the absence of commonly recognized risk factors

Pulmonary thromboembolism is an often fatal complication of venous thrombosis. Any component or combination of the components composing Virchow's triad (venostasis, hypercoagulability, and endothelial damage) increases the propensity for a thrombophilic state. Hypercoagulable states may be inherited or acquired. While the etiology in many cases may be evident either on physical examination or on evaluation of the decedent's medical history, this is often not the case. We conducted a retrospective study of cases presenting to the Jefferson County Coroner/Medical Examiner's Office in Birmingham, Alabama, who were given a diagnosis of pulmonary embolism. A search of cases within the past 23 years yielded 81 cases. An underlying cause was determined in 70 cases (86%). The remaining 11 (14%) cases had no identifiable cause. We believe that a number of these cases may represent an underlying thrombophilic disorder. Since these disorders may be of an inherited or acquired nature, the determination of an etiology may be relevant to the decedent's family. Postmortem blood analyses may in selected cases be useful and appropriate for the detection of some of these disorders. However, such analyses are not practical in all cases, with each case having to be evaluated on its own merits.     

Analysis of the CODIS autosomal STR loci in four main Colombian regions

Genotype polymorphism studies at the 13 loci STRs included in the combined DNA index system [CODIS and PCR-based short tandem repeat loci, in: Proceedings of the Second European Symposium on Human Identification, Promega Corporation, Madison, WI, 1998, pp. 73-88; J. Forensic Sci. 46 (2001) 453] (CODIS: D3S1358, HUMvWA31, HUMFGA, D8S1179 D21S11, D18S51, D5S818, D13S317, D7S820, HUMTH01, HUMTPOX, HUMCSF1PO and D16S539) were carried out in a sample of 1429 unrelated Colombian individuals belonging to 25 different departments. As many other countries in Latino-America, Colombia shows an important admixture component, basically integrated by Amerindians, European-descendants and African-descendants. Due to the fact that only partial population analyses have been carried out in the country, the main aim of the present analysis is to establish a database of forensic interest based on the widely used CODIS systems covering the main Colombian regions.