Holger Wittig

A systematic regional study of dopamine and dopamine-derived salsolinol and norsalsolinol levels in human brain areas

Dopamine and the dopamine-derived tetrahydroisoquinoline alkaloids salsolinol and norsalsolinol were measured by high-performance liquid chromatography with electrochemical detection in 15 regions of the human brain. The regional distribution of dopamine in 32 brains was similar to previous reports with highest concentrations in the basal ganglia, especially in the striatum, followed by the substantia nigra and the hypothalamus. Significant amounts of salsolinol and norsalsolinol were only found in these dopamine-rich areas, whereas in the other regions no alkaloids were detected. These findings suggest that the concentration of the substrate dopamine may determine the alkaloid level during in vivo formation.

Forensic mass screening using mtDNA

At the forensic autopsy of a sexual murder victim, some trace hairs, possibly belonging to the perpetrator, were saved. Initially, the analysis of a pubic hair shaft only revealed the presence of the mitochondrial (mt) DNA haplotype profile consisting of the (CA)6 allele and the complete hypervariable region 1 (HV1) and 2 (HV2) sequence. Later, typing of some further telogene trace hairs, which had been stored for several years, yielded a nuclear short tandem repeat (STR) profile. We used both the mtDNA haplotype and the STR profile to start a DNA mass screening project involving 2,335 male citizens of the relevant communities. MtDNA screening was carried out by using the CA repeat amplification in combination with an SNP typing procedure based on the restriction site analysis of amplified d-loop sequences. The aim of our paper is to put mass screening with mtDNA up for discussion.

Loss of heteroplasmy in the displacement loop of brain mitochondrial DNA in astrocytic tumors.

The aim of this study was the determination of D‐loop heteroplasmy in astrocytic brain tumors. DNA fragments corresponding to the hypervariable region 2 of the mitochondrial displacement loop (D‐loop) from 12 astrocytic tumors and 2 corresponding brain samples were cloned into a plasmid vector. Heteroduplex analysis revealed high sequence variability in the brain samples and a subfraction of grade 2 and grade 3 tumors. Furthermore, the results were suggestive of a very low degree of heteroplasmy in all glioblastomas. This was confirmed by direct sequencing of 223 cloned DNA samples from nine individuals. Heteroplasmy was caused in most cases by a well‐known length polymorphism of a homopolymeric c‐tract. Heteroplasmy of the two reference brain samples was lost in the corresponding tumors. Genes Chromosomes Cancer 26:80–83, 1999.

Mitochondrial DNA in the central european population: Human identification with the help of the forensic mt-DNA D-Loop-Base Database

Sequencing of mtDNA is an advanced method for the individualisation of traces. Disadvantages of this method are expensive and time-consuming analysis and evaluation procedures as well as the necessary stock of population-genetic data which is still insufficient. Central European institutes of forensic medicine from Germany, Austria, and Switzerland have been working together since the beginning of 1998 to establish a mtDNA database. The aim is to build up a large stock of forensically established data and provide population-genetic data for frequency investigations, which will serve as a basis for expert opinions and scientific research. Good data quality is ensured by using original sequences only. Ring tests, which have been conducted to enhance analytical reliability, revealed a high correspondence rate of the analytical results obtained by the individual member institutes. Today 1410 sequences are available for comparison, of which 1285 sequences in the HV1 and HV2 regions cover the full ranges from 16051 to 16365 and from 73 to 340 (according to Anderson). The major part is formed by Central European sequences comprising 1256 data sets from Germany, Austria, and Switzerland. Today the database contains sequences from a total of 12 European, six African and three Asian countries including 100 sequences from Japan. This paper is aimed at discussing the individualisation potentials of mtDNA as well as the possibilities and limits of ethnic differentiation by means of pairwise sequence differences on the basis of the data stock available.

CT- und MRT-Befunde an isolierten Leichenherzen

ZusammenfassungAn 34 isolierten Leichenherzen wurden Computertomographie- (CT-) und Magnetresonanztomographie- (MRT-) Befunde mit pathologisch-anatomischen Befunden und postmortalen Veränderungen verglichen. Innere Totenflecke und postmortale Gerinnselbildungen waren in der MRT, beginnende Fäulnis durch die Darstellung kleiner Gasblasen in der CT gut zu diagnostizieren. Kardiale Verkalkungen der Klappen, der Koronarien und der Papillarmuskeln konnten computertomographisch in ihrem Befallsmuster exakt lokalisiert werden. Ein Septuminfarkt zeigte sich sehr deutlich im T2-gewichteten MR-Bild. Die kollagenen Myokardnarbenareale konnten durch die von ihrer Zusammensetzung abhängigen Kontrastierungen in der T2-Wichtung veranschaulicht werden. Morphologische Veränderungen, wie Hypertrophie und Dilatation, waren sehr deutlich in ihrem Ausmaß auch in der postmortalen Bildgebung zu beurteilen. Die virtuell und real gemessenen Kammerwandstärken stimmten überein. Ein verkalkter Venenbypass mit Thrombosierung war erkennbar. Lediglich eine agonale intramurale Blutung fiel in der primären postmortalen radiologischen Diagnostik aufgrund nur sehr dezenter Kontraste nicht auf. Insgesamt zeigte sich eine sehr gute Übereinstimmung der radiologischen Befunde mit den histologisch bestätigten Sektionsdiagnosen.AbstractComputed tomography (CT) and magnetic resonance imaging (MRI) findings obtained from 34 isolated autopsy hearts were compared to pathoanatomic findings and postmortem changes. MRI clearly revealed internal postmortem lividity and postmortem blood clot formation, whereas small gas bubbles demonstrated by CT referred to beginning putrefaction. The pattern of cardiac calcification of the valves, the coronary vessels and papillary muscles could be exactly located by employing CT. The T2-weighted MR image clearly showed a septal infarction. Due to their composition-based contrast, collagenic myocardial scar areas could be demonstrated in T2 weighted images. Morphological changes, such as hypertrophy and dilatation, could be evaluated for both extent and postmortem pattern. The actual ventricular wall thicknesses were identical with those measured. A calcified venous bypass with thromboses was detected. Primary postmortem radiological diagnosis only failed in a case of agonal intramural bleeding which was not detectable due to highly discreet contrast. In general, the radiological findings obtained were in very good correspondence with the histologically confirmed autopsy diagnoses.

Mitochondrial D-loop (CA)n repeat length heteroplasmy: frequency in a German population sample and inheritance studies in two pedigrees

Sequence analysis of the human mitochondrial genome (mtDNA) has proven to be a valuable tool in forensic identity testing and the analysis of crime scene stains. In contrast to the very expensive sequencing technique, typing of different length variants can greatly facilitate screening of a large number of traces for their relevance during casework. Within the mitochondrial control region, a dinucleotide (CA)n repeat locus is present. To assess the discrimination power of this marker, we have determined (CA)n allele distribution and the frequency of heteroplasmy in a population sample of 2,458 Germans. The inclination to develop heteroplasmic mixtures (CA)n/(CA)n−1 was positively correlated with the number of CA repeats in the mtDNA. In addition, we have studied the inheritance patterns of (CA)n repeat sequence heteroplasmy in two pedigrees. In one pedigree, we also found a length heteroplasmy in the homopolymeric C-tract (nt 303–309). Our data show stable inheritance of heteroplasmy within the homopolymeric C-stretch, but rather unstable inheritance regarding the (CA)n repeat locus.

Zur Frage der Transformation von Atem- in BlutalkoholkonzentrationenExperimentelle Untersuchungen mit einem geeichten Atemalkoholtestgerät Alcotest 7110 Evidential MK III

ZusammenfassungMit dem Alcotest 7110 Evidential MK III, durch die PTB in Braunschweig zugelassen und geeicht, steht ein hochwertiges Gerätesystem zur Messung der Alkoholkonzentration in der Ausatemluft zur Verfügung. Der Umrechnungsfaktor von Atem- in Blutalkoholkonzentrationen wurde von Schoknecht [17] im Gutachten des Bundesgesundheitsamtes 1992 experimentell als BAK/AAK-Quotient mit 2,098 ±0,11 bestimmt und auf 2,1 gerundet. Der Mittelwert von 455 zeitgleichen Wertepaaren der vorliegenden Arbeit lag bei 2,2. Der Maximalwert betrug 3,29, der Minimalwert 0,74. Die Streubreite stimmte im Wesentlichen mit den theoretischen Berechnungen von Wehner et al. [19] überein. Die gefundenen Quotienten wären theoretisch als Umrechnungsfaktoren von AAK in BAK denkbar. Aufgrund der sehr großen Variabilität sollte aber grundsätzlich in forensischen Gutachten eine Transformation von AAK in BAK und umgekehrt nicht erfolgen. Demzufolge erscheint auch eine Rückrechnung mit „transformierten” BAK-Werten oder die Berücksichtigung von angegebenem Nachtrunk nicht möglich. Insbesondere ist ein strafrechtsrelevanter AAK-Grenzwert auch nicht durch einfache Multiplikation zu errechnen, sondern bedarf einer breiten experimentellen psycho-physiologischen und verkehrsmedizinischen Grundlagenforschung.AbstractThe Alcotest 7110 Evidential MK III breath analyser calibrated and approved by PTB in Brunswick is a reliable instrument for measuring breath alcohol concentrations. The results obtained from experimental investigations of the variability of the blood alcohol-to-the breath alcohol ratio expressed by the quotient QBlAC/BrAC were basically identical to the theoretical calculations presented by Wehner et al. Based on the results obtained from experimental investigations to establish a factor for converting breath alcohol into blood alcohol concentrations, an opinion of the Bundesgesundheitsamt of 1992 indicated a blood alcohol to breath alcohol ratio of 2.098 ±0.11 rounded to 2.1 as proposed by Schoknecht [17]. The mean value established in the present paper from 455 sample pairs taken at the same time was 2.2. The maximum value was 3.29 and the minimum value was 0.74. The standard deviations were basically identical to the theoretical calculations of Wehner et al. [19]. Theoretically, the quotients established could be used as factors for converting breath alcohol into blood alcohol concentrations. However, due to large variability breath alcohol concentrations should not be converted into blood alcohol concentrations and vice versa in forensic opinions. This seems to be also true for the use of „transformed“ blood alcohol concentrations for back calculation to the time of offence and alleged after-drink. In particular, as a breath alcohol limit value relevant to criminal law cannot be calculated by a simple multiplication operation, solid research into the physiological and traffic-medical foundations as well as experiments are required to provide a reliable solution.

Variability of mitochondrial DNA in a population sample from Iceland

Over the past decade investigations of human mitochondrial DNA (mtDNA) have considerably contributed to our knowledge about human evolution and migration. The genome of the Icelandic population is of special interest since Iceland has been genetically isolated for centuries. The sequence of the hypervariable regions HVS-I and HVS-II of the mtDNA control region was generated for 100 Icelandic individuals. A total of 75 different mtDNA sequences were observed, of which 19 sequences were shared by more than one individual, 16 sequences were shared by two individuals and two sequences were shared by three individuals; the most frequent haplotype (16129 A, 16239 T, 00263 G and 00315.1 C) was found six times. Both the genetic diversity (0.9925+/-0.0031) and the average number of pairwise nucleotide differences (7.371) were comparable with most of the other European populations. However, we found a smaller number of distinct mitochondrial lineages, suggesting that founder effects and genetic drift may have exerted a visible influence on the Icelandic genetic diversity. We compared these data with 1400 other European sequences from the D-Loop-BASE database. The paper discusses the evolutionary relationship between Icelandic and Central European mtDNA under due consideration of the historical context. Finally, our study has been aimed at increasing the number of mtDNA sequences available throughout the world and contributing to human genome investigations.

DNA-Muster und herkömmlicher Erkennungsdienst. Ein Vergleich

ZusammenfassungDaten aus konservativen erkennungsdienstlichen Maßnahmen können ohne Richtervorbehalt auch bei minder schweren Straftaten erhoben und gespeichert werden. Hierbei werden Personaldaten und äußerlich erkennbare Merkmale dokumentiert. Obligate Fotos lassen ethnische Zugehörigkeiten, Körperbautypen und Krankheitssymptome zu erkennen. Die Daktyloskopie liefert mit Hilfe der „Dermatoglyphic-Methode“ ebenfalls Hinweise auf schwere Erbleiden (Down-Syndrom u.v.a.m). Mit dem DNS-Identifizierungsmuster werden 8 nichtkodierende autosomale Lozi und das Kerngeschlecht am Amelogeninort bestimmt. Insgesamt offenbart das DNS-Identifizierungsmuster wesentlich weniger persönlichkeitsrelevante Informationen als die anderen Methoden. Der Eingriff in die Persönlichkeit ist bei den konservativen Maßnahmen wesentlich größer. Es gibt keine Argumente für eine juristische Ungleichbehandlung der verschiedenen erkennungsdienstlichen Maßnahmen, sowohl in Bezug auf den Richtervorbehalt als auch auf den Straftatenkatalog. Allerdings muss das Probenvernichtungsgebot kontrollierbar eingehalten werden.AbstractData resulting from conservative methods of criminal identification can be collected and stored without judicial review even in cases of less serious crimes. This includes personal data and photographic documentation for ethnical identification, body types and symptoms of diseases or malformations. Moreover, dactyloscopic findings if evaluated by the dermatoglyphic method, would also be indicative of severe hereditary diseases such as Down’s syndrome. The DNA identification pattern includes the determination of eight non-coding autosomal loci and sex determination at the amelogenin locus which can yield results indicative of Down’s syndrome. Generally, the DNA identification pattern yields much less personal information compared to other conservative methods of identification. Therefore, from a scientific or legal viewpoint there is no justifiable reason for the unequal juridicial treatment of the various methods of criminal identification for both judicial review and catalogue of felonies. Of course, the requirement of specimen destruction needs to be transparently complied with.

D-Loop-BASE is online now Central European database of mitochondrial DNA

Abstract At the 18th Stain workshop held in Magdeburg in 1998, 15 university institutes of forensic medicine from Germany, Austria and Switzerland agreed to establish a Central European database of forensically secured mitochondrial DNA (mtDNA) sequences as a common project at the Magdeburg institute. Since then, more than 1600 sequences have been included into the D-Loop-BASE data stock which is now a profound basis for both frequency inquiries for expert opinions and scientific investigations into population genetic matters. Due to the consent agreement signed by the institutes involved, it was not possible in the beginning to access the data via the Internet, which made it difficult for all parties interested to use this database. Among the number of mtDNA databases in the Internet, there has been only one to date offering access to its data which, however, could be used for forensic purposes only to a limited extent. Together with the Institute of Technical Information Systems at the Magdeburg Otto-von-Guericke-University and the database administration, an Internet interface was developed which is available now under www.d-loop-base.de. Online inquiries for both the frequency of individual sequences and biostatistical parameters are possible now. But individual sequences will not be published. This paper shows the opportunities and limits of data inquiries.