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.     

Sudden death associated with a multifocal type II hemangioendothelioma of the liver in a 3-month-old infant

Sudden unexpected death in an infant caused by or associated with neoplasm is rare. We describe a case of a sudden death in an apparently healthy 3-month-old female, in which the autopsy revealed a multiple type II infantile hepatic hemangioendothelioma (IHE). This uncommon tumor has, untreated, a relatively high mortality rate, mainly due cardiac failure resulting from massive arteriovenous shunts, but the association with sudden infant death is very rare.     

Amniotic fluid embolism as cause of death in a car accident--a case report

Amniotic fluid embolism (AFE), a relatively rare complication in pregnancy, has a high mortality rate. We describe a case of a 38-week pregnant woman with such an embolism leading to almost immediate death after a blunt abdominal trauma inflicted in a motor vehicle accident and probably associated with improper positioning of a seat belt. It has been assumed that the pathophysiology of amniotic fluid embolism is related to an anaphylactoid reaction and that mast cell degranulation indicates this mechanism. Moreover, immunohistochemical antitryptase staining of pulmonary tissue samples in our case revealed mast cell degranulation.     

Effect of hair care and hair cosmetics on the concentrations of fatty acid ethyl esters in hair as markers of chronically elevated alcohol consumption

Fatty acid ethyl esters (FAEE) can be used as alcohol markers in hair. It was investigated in this study whether this diagnostic method is disturbed by hair care and hair cosmetics. Traces of ethyl myristate, ethyl palmitate, ethyl oleate and ethyl stearate were detected in all of 49 frequently applied hair care products by headspace solid phase microextraction (HS-SPME) and gas chromatography-mass spectrometry (GC-MS). The highest concentration was 0.003% in a hair wax. From experiments with separated hair samples of alcoholics as well as from the evaluation of the FAEE concentrations and the data about hair care of 75 volunteers (alcoholics, social drinkers and teetotalers) follows that usual shampooing, permanent wave, dyeing, bleaching or shading are of minor importance as compared to the drinking amount and other individual features. However, false positive results were found after daily treatment with a hair lotion containing 62.5% ethanol, with a deodorant and with a hair spray. As an explanation, it is assumed that FAEE are formed in the sebum glands also after regular topical application of products with a higher ethanol content.     

Detection and assay of cis- and trans-isomers of 4-methylaminorex in urine, plasma and tissue samples

The 4-methylaminorex (4-MAX) is an amphetamine-related psychostimulant drug that has appeared on the clandestine market with a street name of "U4Euh". This compound exists as four stereoisomers, trans-4R,5R, trans-4S,5S, cis-4R,5S and cis-4S,5R, of which the cis forms have been classified as Schedule I substances in the US. The increasing variety of designer drugs has highlighted the importance of detection, identification, and quantitative measurement of these drugs, including 4-MAX, in biological samples. In the present study, the isomers of 4-MAX were detected in urine of rats treated with the drugs by some but not all of the on-site immunoassays tested, mainly as amphetamine or methamphetamine. To facilitate identification of 4-MAX by laboratories specialized in drug analysis, the electron-ionization mass spectrum and TLC data for underivatized 4-MAX using a routine laboratory drug-screening procedure is provided. In addition, a GC/MS method is described for the quantitative determination of cis- and trans-4-MAX as tert-butyldimethylsilyl-derivatives in plasma, urine and tissue.     

Maternal Child-Rearing Attitudes and Role Satisfaction and Children's Temperament as Antecedents of Adolescent Depressive Tendencies: Follow-up Study of 6- to 15-Year-Olds

Development of depressive tendencies was assessed over a 9-year period in a random sample of 389 Finnish children. Predictors of maternal role satisfaction and hostile child-rearing attitudes, assessed when the children were ages 6 and 9 years, respectively, and a temperament predictor of perceived child difficultness, assessed when the children were age 6 years, were measured using questionnaires designed for this study. Depressive tendencies were assessed by a self-report at age 15 (modification of Beck's Depression Inventory). Using structural equation modeling, we tested a hypothesized model comprising direct as well as mediated effects between the childhood predictor variables and adolescent depressive tendencies. The results indicated support for a similar mediational model in girls and boys. Low maternal role satisfaction and maternal perceptions of child difficultness, measured when children were age 6 years, predicted hostile maternal child-rearing attitudes measured when children were age 9 years, which in turn had a significant direct effect on depressive tendencies among these children during adolescence. The only other direct effect was found solely in girls: Low maternal role satisfaction predicted adolescent depressive tendencies. These results underline the close interplay of child temperament and mothering factors in the development of depressive tendencies in girls and boys.     

Examples for use of the STR systems in stain assessment with special reference to Y chromosome systems

The authors describe 3 cases where Y-chromosomal systems were used for typing the biological traces. In the first case, a murder, for the major amount of cell material found on a dish towel (and analysed two years after the crime) female persons were excluded for the system amelogenin and Y-chromosomal systems. A brother of the victim could not be excluded for autosomal STR-systems. Upon confrontation with the results of the DNA-analysis (among other things), this brother confessed the murder of his sister some days later. He was found guilty by the court. In the second case described, a rape of two girls, many traces were analysed parallely with Y-chromosomal and autosomal PCR-systems. The objects where male DNA matching the suspect were found (a paper tissue, a sweat shirt and the knickers of the girls), also showed small amounts of alleles matching with the suspect for autosomal systems, while the major part in these systems was from the girls. The suspect was sentenced to many years imprisonment. In the third case, a possible rape of a young woman, a stained microscope slide of a vaginal swab had to be examined. Microscopically a few sperm heads could be seen in a surplus of leucocytes. The male proportion could be analysed only in the Y-chromosomal systems, not in the autosomal ones. For the frequency calculation of the Y-chromosomal allele combination the haplotype data bank of the Institute for Legal Medicine of the Humboldt university in Berlin was indispensable.