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H J Weisser

Publications and source records attributed to H J Weisser.

14 recordsLinked to original sources
PubMed2001

Transfer of biological traces in cases of hanging and ligature strangulation.

In hanging and ligature strangulation, the noose mostly causes a mark or groove which is formed partly by compression of the skin and partly by abrasion with loss of the upper epidermal layers. The horny scales abraded from the neck may be transferred to the strangulation device or to the interposed textiles where they are sometimes visible at stereomicroscopic examination or even to the naked eye as silver-grey particles. The morphologic features of the epidermal transfer due to hanging and ligature strangulation is demonstrated by 14 case examples. The biological traces may be sufficient for comparative DNA typing by means of PCR-based methods. In 9 out of the 14 cases, genomic DNA typing was successful. Analysis of mtDNA succeeded in another two cases, although genomic DNA could not be detected. Beside the accumulation of solid epidermic particles the paper describes deposition of serous and fatty tissue fluid at the ligature (mainly adjacent to skin ridges).

Adult↗
PubMed2000

DNA typing of human remains found in damp environments.

DNA typing is often used to determine identity from human remains. The environment to which the material has been exposed, however, is crucial for the success of the investigation. Damp conditions in particular can cause a rapid degradation of DNA, even in bone and teeth, and thus reduce the chances of successful typing. Here, we present the results of investigations performed on four skulls that had been lying in a damp environment for periods ranging from almost 1 year to about 45 years. In none of these cases was DNA typing successful on bone or, where present, on teeth. Where remnants of brain tissue were used, however, complete STR typing was possible in one case, partial STR typing in another, and mtDNA sequencing could be carried out in three cases. These findings suggest that brain tissue is relatively resistant to putrefaction in damp environments and, unlike bone, appears to exhibit a certain degree of protection against DNA degradation.

Aged↗
PubMed2000

Is it possible to differentiate mtDNA by means of HVIII in samples that cannot be distinguished by sequencing the HVI and HVII regions?

The mitochondrial control region includes three so-called hypervariable (HV) regions, in which the polymorphic positions show a particularly high frequency. According to a population study of 200 unrelated individuals from Germany, HVI (positions 16,024-16,365, according to Anderson) showed 88 variable positions in a total length of 342 bp (26%) and HVII (positions 73-340) displayed 65 mutable sites in 268 bp (24%). HVIII (positions 438-574) exhibited a slightly lower variability, with 25 polymorphic sites within 137 bp (18%), but contrasted clearly with the background, which showed variability rates of only 7% (positions 16,366-16,569, 1-72) and 3% (positions 341-437), respectively. At present, the displacement (D)-loop database in Magdeburg comprises 904 sequences of the mitochondrial HVI region and HVII region from Germans, Austrians and Swiss. By means of this material, the extent to which the mtDNA sequences that do not differ in the HVI and HVII regions can be differentiated by additionally sequencing HVIII was investigated.

Austria↗
PubMed2000

Mitochondrial heteroplasmy among maternally related individuals.

The second hypervariable segment of the human mtDNA control region contains a homopolymeric tract of cytidines between nucleotides (nt) 303 and 315, interrupted by a thymidine at position 310, according to the Cambridge reference sequence. By direct sequencing, some individuals show blurred sequence chromatograms in this region which are not caused by a sequencing artefact but by high levels of length heteroplasmy. With respect to this length heteroplasmy ten maternally related individuals and two unrelated probands were examined. The relative proportions of length variants in the homopolymeric tract in selected individuals were determined by cloning and sequencing of multiple independent clones. All ten family members examined were heteroplasmic while the proportions of each genotype varied widely in different individuals. The size of a possible mitochondrial bottleneck during embryonic development of the offspring is discussed with respect to the changes in mitochondrial haplotypes within mother-offspring pairs. Our data are consistent with both slow and rapid segregation of mtDNAs between the generations, which would implicate a tight as well as a wide bottleneck. Therefore, a common bottleneck size in all individuals from this lineage seems to be very unlikely.

Chromosome Segregation↗
PubMed1999

PCR typing of human semen stains after SEM-EDX examination.

There is an increasing demand to use scanning electron microscopy in the forensic analysis of biological samples. Such analyses are routinely used for the investigation of blood stains, seminal stains, diatoms, residues on wounds and residues and trace elements in gunshot powder. The same samples are sometimes also required for identification via DNA analysis, e.g. blood stains, seminal stains or epidermal cells. The ionising radiation provokes damage to DNA and also to membrane and protein structure. The question therefore arises whether the usual sequence of such an investigation, i.e. prior application of SEM and afterwards analysis of DNA, can affect the success rate of the DNA analysis. We have therefore experimentally exposed semen samples to a defined electron beam for different time intervals varying between 1 and 25 min and afterwards performed quantitative and qualitative DNA analysis. Our studies revealed that sample treatment with an electron beam does not interfere with subsequent DNA typing by various currently used forensic PCR systems.

DNA↗
PubMed1998

Location and frequency of polymorphic positions in the mtDNA control region of individuals from Germany.

In order to identify polymorphic positions and to determine their frequency in the human mitochondrial D-loop containing region, the mitochondrial DNA (mtDNA) control region of 200 unrelated individuals from Germany were amplified and directly sequenced. Sequence comparison led to the identification of 190 mitochondrial lineages as defined by 202 variable positions. The most frequently occurring lineage comprised 5 individuals, whereas 186 types of D-loop sequences were observed in only one individual. Of the sequences studied 7% are not unique but show at least one counterpart with an identical haplotype. The majority (61%) of the control regions investigated showed between four and eight nucleotide positions deviating from the reference sequence. The maximum number of deviations observed in a single control region was 18. The majority of the variable positions in the D-loop region (88%) are located within three hypervariable regions. Sequence variations are caused by nucleotide substitutions, insertions or deletions. As compared to insertions and deletions, nucleotide substitutions make up the vast majority of the mutations (90%). We have predominantly found transitions (75%) and a significantly lower frequency of transversions (15%) whereas insertions (6%) as well as deletions (4%) are rather rare. Upon sequencing the mitochondrial control region from 200 German Caucasians the genetic diversity was estimated at 0.99. The probability of two randomly selected individuals from a population having identical mtDNA types is 0.6%.

Base Sequence↗
PubMed1996

mtDNA as a tool for identification of human remains. Identification using mtDNA.

Two cases are presented in order to emphasize the importance of mitochondrial DNA in forensic medicine. The first case involved a charred body which could not be identified by morphological means because of severe destruction of all tissues. The parallel use of PCR methods using genomic DNA and sequencing of the mitochondrial d-loop region produced unequivocal and reproducible results. In the second case, various parts of a highly decomposed body were investigated. The application of standard PCR methods for genomic DNA proved unsuitable to answer the question whether the body parts belonged to the same body. However, when sequencing of mitochondrial DNA segments amplified from tissue and bone samples was performed, clearly interpretable results were obtained.

Adult↗
PubMed1992

[RFLP analysis of single hairs].

Investigations were performed with the root of one hair torn out 6 times in parallel. Yield of DNA was about the same with 6 extraction methods tested. Hairs stored at RT up to 8 weeks in non sterile environment showed the same result as deeply frozen hairs. Hairs of one test person could not be typed in repeated investigations, whereas hairs of another person could successfully be typed in every case (n > 100). 35 hairs of 66 samples investigated from 11 other persons could be typed.

Chromosome Mapping↗
PubMed1991

DNA profiling of bloodstains on linen pretreated with remedies used for cleaning and maintaining clothes.

Linen was pretreated with 20 remedies for cleaning and maintaining clothes and 20 microliters blood was applied on each sample and dried. Restriction enzyme digest of bloodstain DNA was irregularly inhibited by highly concentrated residues of 2 detergents and a stain-remover and colour-brightener. An additional dialysis step to purify DNA (Gill 1987) reliably prevented disturbance. High molecular DNA was obtained in every case and bandshifts were not observed.

Bedding and Linens↗
PubMed1991

[Modification of DNA typing of blood stains by textile stain carriers].

Samples of 20 microliters blood were applicated von 55 different textiles, containing all usual materials for clothes, straight from the fabric and after thorough washing. DNA profiling was influenced only by blue jeans and blue terry towel straight from the fabric; in some of these samples there was an inhibition of the restriction enzyme digest that could not be prevented by an additional dialysis step.

ABO Blood-Group System↗
PubMed1990

The gene for Klebsiella bacteriophage K11 RNA polymerase: sequence and comparison with the homologous genes of phages T7, T3, and SP6.

We determined the nucleotide sequence of gene 1 of Klebsiella phage K11, which is a member of the T7 group of phages. The largest open reading frame corresponds to a polypeptide with 906 amino acids and a molecular weight of 100,383 daltons. The deduced amino acid sequence of this polypeptide shows 71% homology to the T7 RNA polymerase (the product of T7 gene 1), 72% homology to the T3 RNA polymerase and 27% homology to the SP6 RNA polymerase. Divergent evolution was clearly most pronounced in the amino-terminal portion.

Amino Acid Sequence↗
PubMedDate not supplied

[Significance of mitochondrial DNA for forensic stain analysis, identification and forensic lineage determination].

DNA testing using conventional STR systems may produce insufficient results, if the genomic DNA in the specimen is either highly degraded or the available quantity is very small (e.g. skin particles, hair shafts or ancient bones). In some of these cases the examination of mitochondrial DNA, which is present in considerably larger copy numbers in the cytoplasm, is more successful than that of nuclear DNA. Identification of unknown corpses by conventional DNA typing sometimes remains doubtful, if only samples from presumably distant relatives or putative brothers or sisters are available for comparison. Since mitochondrial DNA is generally transmitted in maternal lineages, its sequence pattern can be directly compared with those of other individuals and, in case of the same maternal lineage, corresponding sequence chromatograms are to be expected. In connection with nuclear DNA typing methods certain sequence motives may furnish clues to ethnic groups. The report presents three cases illustrating the application possibilities of mtDNA typing in forensic practice.

Adolescent↗