STR analysis of artificially degraded DNA-results of a collaborative European exercise

Degradation of human DNA extracted from forensic stains is, in most cases, the result of a natural process due to the exposure of the stain samples to the environment. Experiences with degraded DNA from casework samples show that every sample may exhibit different properties in this respect, and that it is difficult to systematically assess the performance of routinely used typing systems for the analysis of degraded DNA samples. Using a batch of artificially degraded DNA with an average fragment size of approx. 200 bp a collaborative exercise was carried out among 38 forensic laboratories from 17 European countries. The results were assessed according to correct allele detection, peak height and balance as well as the occurrence of artefacts. A number of common problems were identified based on these results such as strong peak imbalance in heterozygous genotypes for the larger short tandem repeat (STR) fragments after increased PCR cycle numbers, artefact signals and allelic drop-out. Based on the observations, strategies are discussed to overcome these problems. The strategies include careful balancing of the amount of template DNA and the PCR cycle numbers, the reaction volume and the amount of Taq polymerase. Furthermore, a careful evaluation of the results of the fragment analysis and of automated allele calling is necessary to identify the correct alleles and avoid artefacts.     

Trace analysis of peroxide explosives by high performance liquid chromatography-atmospheric pressure chemical ionization-tandem mass spectrometry (HPLC-APCI-MS/MS) for forensic applications

An HPLC-APCI-MS(/MS) method for the (trace) analysis of the most commonly encountered peroxide explosives, hexamethylenetriperoxidediamine (HMTD) and triacetonetriperoxide (TATP), has been developed. With this method, HMTD and TATP have been analyzed in the same run. (Pseudo-)molecular ions of these peroxides have been obtained as base peak under the same condition. A series of product ions was produced from these pseudo-molecular ions ([HMTD - 1]+ and [TATP + NH4]+) in the MS/MS analysis. We also pioneered in showing that a TATP molecular ion [TATP + H]+ can be observed with HPLC-MS/MS. The limit of detection for HMTD and TATP was 0.26 and 3.3 ng, respectively, on column by HPLC-MS in the Full Scan mode and 0.08 and 0.8, respectively, by HPLC-APCI-MS/MS in Selected Reaction Monitoring (single mass unit) mode. The method presented has been applied successfully for the identification of peroxides in the bulk solid state (powder sample), as well as in post-blast extracts originating from a forensic case. For the post-blast extracts, the use of tandem MS has been shown clearly to be of crucial importance for the identification and detection of the peroxide explosives.     

Allele frequencies data and statistic parameters for 16 STR loci-D19S433, D2S1338, CSF1PO, D16S539, D7S820, D21S11, D18S51, D13S317, D5S818, FGA, Penta E, TH01, vWA, D8S1179, TPOX, D3S1358-in the Rio de Janeiro population, Brazil

Allele frequencies for 16 short tandem repeats (STR) loci were determined with a sample of 230-300 unrelated individuals from the population of Rio de Janeiro, Brazil. The loci are the most commonly used in forensic and paternity testing, being analysed by the Identifiler (Applied Biosystems) and PowerPlex 2.1 (Promega) commercial kits. It was proved that Penta E and D18S51 are the most polymorphic loci.     

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.     

Allelic frequencies at 12 STR loci in Colombian population

Three hundred and twenty-six to four hundred and fifty-one individuals were typed for 12 STR markers and revealed by silver stain method and assisted by a computer analysis. Forensic and Hardy-Weinberg values were found. The Kodak ds 1D Image Analysis Software V 2.0.3 EDAS DC 120 System was a useful tool for determining the correct size of pattern bands that were out allelic ladders, alleles 18 and 17 from F13A01, 15 from TPOX and 4 from TH01 were determined by this method and some corroborated by automatic analysis.     

STR data for 09 autosomal STR markers from Rio Grande do Sul (southern Brazil)

Allele frequencies for 09 STR autosomal loci (D3S1358, D5S818, D7S820, D8S1179, D13S317, D18S51, D21S11, FGA and VWA) included in the AmpFlSTR Profiler Plus were obtained from a sample of unrelated individuals from Rio Grande do Sul (southern Brazil).     

What Patent Data Reveal about Universities: The Case of Belgium

In recent years, there has been a surge in patenting by Belgian universities. It appears that this increase can be attributed to growth of biotechnology, where there is a greater propensity to patent, to a desire on the part of universities to enhance commercialization through technology transfer offices (TTOs), and to effective collaboration between universities and government-sponsored research centers. Our qualitative analysis reveals that patent statistics could be a misleading indicator of an individual university's technological productivity, since many inventions are developed at universities, yet applied by other institutions.     

Glucose and lactate in vitreous humor compared with the determination of fructosamine for the postmortem diagnosis of diabetes mellitus

Diabetes mellitus is a chronic metabolic illness responsible for a great number of deaths. In postmortem diagnosis, because of the difficulty involved in interpreting blood glucose levels and relatively nonspecific pathologic features, biochemical markers in vitreous humor are useful. The aim of this study was to compare the results obtained for the combined determination of lactate and glucose with fructosamine levels recorded in the vitreous humor of two diagnostic groups (one diabetic and the other nondiabetic). The authors intended to ascertain the capacity of different markers measured in vitreous humor to diagnose diabetes mellitus. Fifty-one cadavers (mean age, 58.7 years; standard deviation, 17.09) were studied. The mean postmortem interval was 16.4 hours (standard deviation, 9.05). Cases were assigned to two diagnostic groups according to whether they were previously diagnosed as either diabetic or nondiabetic. Statistically significant differences for glucose, fructosamine, and the sum values of glucose and lactate were found between the two diagnostic groups. The highest levels were obtained in the group of cases with a previous diagnosis of diabetes mellitus. After the comparison of receiver operating characteristic curves, the sum values of glucose and lactate in vitreous humor is a better predictor of antemortem diabetes mellitus than the fructosamine.     

Piperazine-like compounds: a new group of designer drugs-of-abuse on the European market

1-Aryl-piperazine compounds are, depending on their substituents, selective for certain serotonin receptors and together with their easy availability and their so-called legal status, this group of psychoactive compounds are potential designer drugs-of-abuse. Internet in that respect is an important source of information and distribution facilities. Because this development may have consequences for the interpretation of future clinical and forensic toxicological case studies, some analytical aspects of 1-benzyl-piperazine (BZP), 1-[4-methoxyphenyl]-piperazine (pMeOPP) and 1-[3-trifluoromethylphenyl]-piperazine (TFMPP) were studied. BZP was not detected by the AxSYM FPIA technology designed to determine amphetamine-like compounds, but had showed some cross reactivity with EMIT d.a.u.. The cross reactivities at 300 and 12,000ng/ml (RS)-amphetamine equivalents were 0.4 and 1.3%, respectively. Although BZP was not identified directly by the REMEDi HS Drug Profiling System, it can be detected by this HPLC/UV scanning system. Using GC/NPD without derivatisation, BZP, pMeOPP and TFMPP can be analysed for and applying GC/MS without or with acetylation or trifluoroacetylation, these compounds can be identified unambiguously. The usefulness of GC/NPD and GC/MS in this respect was demonstrated by the quantitative and qualitative analysis of the content of a capsule with the synthetic stimulant A2, which proved to contain 86.4mg of BZP.