Characterization of human DNA in environmental samples

Environmental samples from indoor surfaces can be confounded by dust, which is composed largely of human skin cells and has been documented to contain roughly tens of micrograms of total DNA per gram of dust. This study complements previous published work by providing estimates of the quantity of amplifiable human DNA found in environmental samples from a typical indoor environment, categorized by the intensity of human traffic and visible quantity of dust. Dust was collected by surface swabbing standard 576 cm² areas in eight locations, and evaluated for total DNA quantity, presence of human DNA (mitochondrial and nuclear loci using conventional PCR), quantity of human nuclear DNA using quantitative PCR, and STR analysis. The total DNA content of 36 dust samples ranged from 9 to 28 ng/cm², and contained 0.2–1.1 pg/cm² of human DNA. Overall, human DNA was detected in 97% of 36 dust samples and 61% of samples yielded allele distributions of varying degrees of complexity when subjected to STR analysis. The implications of this study are twofold. First, the presence of dust in evidence can be a significant contamination source in forensic investigations because the human DNA component is of sufficient quality and quantity to produce allele calls in STR analysis. This can be effectively managed by implementing stringent protocols for collection and analysis of potential biological samples. A second implication is the use of dust as a source of evidence for identification of inhabitants within a defined location. In the latter case, a number of additional studies would be necessary to identify relevant pretreatments for environmental dust samples and to develop the necessary deconvolution techniques to separate the composite genotypes obtained.     

Bio-Kraftstoff,Nachhaltigkeit, Boden- und Naturschutz

Zusammenfassung  Um ihr Klimapaket und die damit verbundenen Ziele im Bereich der erneuerbaren Energien umzusetzen, hat die Europ?ische Kommission eine Richtlinie zur F?rderung der Nutzung von Energie aus erneuerbaren Quellen vorgeschlagen. Um den Richtlinienentwurf rankt sich – auch noch zur Zeit – eine breite noch nicht abgeschlossene Diskussion, in deren Rahmen unter anderem Bedenken gegen die F?rderung von Energiepflanzen, die als nachhaltig deklariert wird, ge?u?ert werden, da blühende Kulturlandschaften dadurch verschandelt werden. Der Beitrag besch?ftigt sich mit der politischen und rechtlichen Diskussion des Richtlinien-Entwurfs.     

Klagebefugnis anerkannter Naturschutzvereine bei der Genehmigung von Bauvorhaben im Außenbereich

Ohne Zusammenfassung     

Fatalities in the bathtub

A retrospective analysis concerning deaths in the bathtub was carried out in the Institute of Legal Medicine in Hamburg. The study includes 245 death cases between 1971 and 1988 (1% of all autopsies). 66 cases proved to be natural deaths, 76 were classified as suicides, 39 as accidents and 13 as homicides; 51 fatalities remained unclear with respect to one of these groups. Among the natural deaths sudden cardiac deaths were dominating (n = 39), among the suicides the intoxications (n = 37) and electrocutions (n = 20), and among the accidents the intoxications by carbon monoxide (n = 17) and electrocutions (n = 12). Out of 13 homicides only 2 were committed directly in the bathtub: One by drowning of a child and one by electric current via a hair dryer; in the other cases the dead body was put into the bathtub post mortem. About 50% of the victims were alcoholized. Signs of drowning were present in about 40% of all cases; the most frequent finding was emphysema aquosum.     

Application of a simple extraction procedure using aqueous ammonia to the analysis of basic drugs in blood by gas chromatography

A simple and reliable previously reported extraction procedure has been extended to the analysis of a wide range of basic and neutral drugs in postmortem blood and other tissues. The method employs 200 microliters of blood treated with water and ammonia and extracted with diethyl ether. The concentrated extract is generally sufficiently clean for direct analysis by gas chromatography and high pressure liquid chromatography. Recovery, precision and linearity data are presented for selected drugs.