Biomedical subjects

P Wiegand

Publications and source records attributed to P Wiegand.

At least 37 records · Page 2Linked to original sources

PubMed1995

Microsatellite polymorphisms reveal phylogenetic relationships in primates.

We amplified, via PCR, DNA segments from intron 1 of the tyrosine hydroxylase gene (TH01) and intron 40 of the von Willebrand factor gene (VWA) in ten nonhuman primate genera. In humans both introns contain polymorphic microsatellites with tetrameric repeats. Compared to the allelic ranges in human populations relatively short repeat arrays could be detected for the nonhuman primates typed, presumably reflecting an ancient precursor state at both microsatellite loci. Furthermore, our results provide evidence for an association of the average number of repeats present in different primate genera and their divergence time from man. DNA sequencing of VWA orthologues revealed a relatively high variability in the arrangement of repeats in the 5'-repeat arrays, the generation of which could probably be explained by polar mutational events.

Animals↗

PubMed1995

CMV-DNA detection in parenchymatous organs in cases of SIDS.

A nested PCR approach has been developed especially for the detection of small amounts of cytomegalovirus (CMV) DNA in autopsy samples. Lung tissue and submandibular glands in 118 cases of infant death (92 SIDS cases, 13 natural deaths due to other defined causes and 13 unnatural deaths) were investigated by this technique and compared to the results obtained by other CMV detection methods (histology, immunohistochemistry, in situ hybridization and PCR). CMV-DNA could be detected in the lung tissue in 7 cases of SIDS using nested PCR. Compared to conventional PCR (3 positive cases in lung tissue) the nested approach always gave glear results and showed less additional bands. In all cases where CMV could be detected in the lungs, positive results were also obtained in the submandibular glands. The nested PCR method proved to be a more sensitive technique than the other detection methods including PCR and hot start, and even minimal amounts of target DNA could be detected in the presence of human and bacterial background DNA.

Autopsy↗

PubMed1995

Phenotype differences of STRs in 7 human populations.

A maximum of 6 STR systems (TH01, VWA, ACTBP2, FES, F13B, D21S11) was investigated in 7 human populations (Germans, Turks, Moroccans, Japanese, Chinese, Papuans, Ovambos). In each population no deviations from Hardy-Weinberg equilibrium were observed. Out of each population the phenotypes of 50 individuals (comprising 3 to 6 STRs) were randomly selected. Based on the phenotype frequencies interpopulation comparisons were carried out using the frequencies of each other population. Within major ethnic groups only minor differences in phenotype frequencies were found. Between major ethnic groups differences of up to several orders of magnitude could be observed. The most discriminative STRs for interpopulation comparisons were TH01, FES and F13B.

China↗

PubMed1995

GEDNAP IV and V. The 4th and 5th Stain Blind Trials using DNA technology.

In the collaborative exercise GEDNAP IV one EDTA blood sample (2 ml) and 5 bloodstains (0.5 ml on cotton) were investigated and in GEDNAP V, a total of 8 bloodstains (0.5 ml on cotton), including 2 mixed bloodstains. DNA typing was carried out using the RFLP systems YNH24/Hinf I and MS43a/Hinf I and the PCR systems HLA DQ alpha, D1S80, ApoB and YNZ22. In both exercises approximately 20 laboratories obtained results using the RFLP systems. Of the PCR systems, D1S80 was the most commonly used (14 labs in GEDNAP IV; 18 labs in GEDNAP V). The interlaboratory standard deviation for YNH24 in both exercises was approx. 0.6%, for MS43a 0.7-2.2% (GEDNAP IV) and 0.4-1.4% (GEDNAP V), depending on the fragment size. The fragment size calculation performed in each laboratory yielded a standard deviation twice that obtained when the fragment size calculation was performed centrally (IfR, Münster). In GEDNAP III, a system-specific corridor was developed to define the limits of deviation; this was modified for the present study by combining the fragment size ranges of YNH24 and MS43a. In both studies a subgroup of laboratories was involved in preliminary exercises using three PCR VNTRs and the system HLA DQ alpha. Owing to the substantial variation in experience of the participating laboratories with PCR typing the results obtained in these two studies do not fulfil the basic quality criteria of the GEDNAP studies.

Apolipoproteins B↗

PubMed1995

Observation of null alleles apparently due to deletions.

After examining 2 paternity cases in 17 classical, 4 RFLP and 5 PCR-VNTR systems, isolated pseudo-exclusions were observed in the polymorphism D2S44 (YNH24). In both cases the "exclusions" were due to apparent opposite homozygosity. The application of different restriction enzymes, PCR amplification and varying electrophoretic conditions each led to an equivalent result of a 1-band-pattern with a mismatch between both father/child pairs. From these results the authors conclude that a complete or almost complete loss of the alleles is the most probable explanation.

Alleles↗

PubMed1995

Frequency profiles of 3 STRs in a Turkish population.

Population genetic studies were carried out on Caucasians from southern Turkey (n = 204 individuals) using the short tandem repeat (STR) systems HumTHO1, HumVWA and HumACTBP2. After electrophoresis in polyacrylamide gels, 6 alleles could be identified for HumTHOI, 7 alleles for VWA and 26 alleles for ACTBP2. No significant deviations from Hardy-Weinberg equilibrium could be observed.

Belgium↗

PubMed1995

PCR analysis of the short tandem repeat (STR) system HUMVWA31. Allele and genotype frequencies in an Italian population sample.

A population study in a sample of 211 unrelated individuals from 2 cities in North and Central Italy was carried out to investigate the short tandem repeat (STR) system HUMVWA31. Separation of PCR- amplified DNA fragments was performed by high-resolution horizontal denaturing polyacrylamide gel electrophoresis (PAGE) followed by silver staining. The 7 common alleles were found, together with a new smaller allele. Distribution of the observed genotypes did not deviate from Hardy-Weinberg (H-W) equilibrium. The power of discrimination for this locus was 0.93 and the chance of exclusion was 0.61. Good agreement was found between the allele frequencies in 2 Italian population samples and previous studies on Caucasians. The results of this study suggest that this STR system may be a useful tool in forensic investigations.

Alleles↗

PubMed1995

Structure of new mutations in 2 STR systems.

Isolated father/child mismatches in cases with a high probability of paternity (W > 99.9%) have been investigated using short tandem repeat (STR) systems. According to the high probability of paternity new mutations could be assumed in these cases. A new mutation could be observed in 3 cases using the STR system HumACTBP2. Two of these cases showed a deletion and 1 case an insertion of 1 repeat (AAAG-motif) which could be verified by sequencing. In another paternity case a new mutation--1-repeat insertion (TCTA-motif)--in the HumVWA system was detected and verified by sequencing. These findings led to a new mutation rate of 0.7% (n = 453 meioses) for HumACTBP2 and 0.2% for HumVWA (n = 484 meioses).

Adult↗

PubMed1995

Population genetic study from the Zagreb area using 3 STR systems.

Population genetic studies were carried out on Caucasians from north-west Croatia (Zagreb-area) using the short tandem repeat (STR) systems HumTHO1, HumVWA and HumACTBP2. After electrophoresis in PAG, 6 alleles could be identified for HumTHO1 in a sample size of 100 unrelated individuals and 7 alleles were found for VWA. For ACTBP2, 25 alleles have been identified. No significant deviations from Hardy-Weinberg equilibrium could be observed.

Alleles↗

PubMed1995

D1S80 (pMCT118): analysis of 3 ethnic subpopulations living in Brussels.

Population genetic studies were carried out on 3 ethnic subpopulations living in Brussels (119 Belgians, 120 Turks and 137 Moroccans). DNA extraction was performed using the Chelex method. After DNA amplification the DNA fragments were separated electrophoretically in horizontal polyacrylamide gels. A total of 32 alleles (between 21 and 25 alleles in each subpopulation) including 8 "interalleles" could be differentiated. The allele frequencies were compared with population data from a German study and no significant differences could be observed.

Alleles↗

PubMed1994

Population data and forensic efficiency values for the STR systems HumVWA, HumMBP and HumFABP.

Population studies were carried out on Caucasians from north-west Germany using the short tandem repeat (STR) systems HumVWA (locus: 12p12-12pter), HumMBP (locus: 18q23-pter) and HumFABP (locus: 4q28-q31). After electrophoresis 9 alleles could be identified for HumVWA in a sample size of 321 unrelated individuals and 4 alleles were found for HumFABP in 106 individuals. For HumMBP-A 10 alleles and for HumMBP-B 7 alleles and 1 intermediate allele were determined in a sample size of 143 individuals. No deviations from Hardy-Weinberg equilibrium could be observed. In a small family study (HumVWA-n = 129; HumMBP-n = 59; HumFABP-n = 48) no new mutations could be found for HumMBP-A and HumFABP whereas 2 mutations were found in HumMBP-B and one mutation in HumVWA. Positive results could be obtained from 1 ng-20 pg (HumVWA, HumFABP) and 1 ng-100 pg (HumMBP) template DNA.

Alleles↗

PubMed1994

Comparison of different methods for CMV detection.

The submandibular glands were investigated in 77 cases of SIDS using histology, immunohistochemistry (IHC), in situ hybridization (ISH) and PCR to detect cytomegalovirus (CMV) inclusion disease. The aim of the investigation was to establish the detection of CMV by PCR as a model for the detection of other types of virus by PCR, especially for the detection of viruses which affect the respiratory system of babies. In 14 cases the CMV detection was possible. Typical changes of duct cells associated with CMV infection were observed in 9 by histology and in 4 further cases by IHC. In comparison to these methods, ISH showed a higher sensitivity but only one more positive case was found. Theoretically the PCR method is more sensitive than ISH and more convenient from the practical aspect. Detection of CMV by PCR was possible in 10 out of 14 positive cases. All PCR positive cases were cases showing an active disease but not latent infection.

Cytomegalovirus↗

PubMed1993

[Individualized DNA analysis in insurance medicine clarifications].

DNA investigations for the clarification of problems in insurance medicine can be subdivided into 3 groups (1) Traffic accidents (2) identification (3) questionable fraud cases. The development in individualisation by DNA analysis has progressed from the initial restriction fragment length polymorphisms (RFLPs) to the PCR-based polymorphisms. PCR systems are characterised by a very high sensitivity of detection and a high degree of success with highly degraded biological material. The current possibilities for DNA analysis are described and exemplified with special reference to PCR-based polymorphisms.

Accidents, Traffic↗

PubMed1993

Forensic validation of the STR systems SE 33 and TC 11.

Population studies on Caucasians from northwest Germany were carried out using the short tandem repeat (STR) systems SE 33 (Locus: ACTBP2) and TC 11 (Locus: 11p15.5). After electrophoresis in PAG 26 alleles could be identified for SE 33 in a sample size of 180 unrelated individuals and 6 alleles were found for TC 11 in 110 individuals. The combined mean exclusion chance for both systems was 0.96 and the discrimination index 0.999. No significant deviations from Hardy-Weinberg equilibrium could be demonstrated. In a small sample of families (SE 33 - n = 21; TC 11 - n = 30) no new mutations could be found. Positive and reproducible results for both STRs could be obtained from 50 pg template DNA.

Alleles↗

PubMed1993

DNA typing of debris from fingernails.

In 3 series paired volunteers were asked to gently scratch each other with the fingernails to produce superficial abrasions only of the stratum corneum. In a 4th series scratch marks were produced in the skin of cadavers but additionally including the deeper epidermal layers. Debris was removed using a thorough technique in series 1 and 2 and a careful technique in series 3. After DNA extraction, the debris was typed using the STR systems HUMACTBP2 (SE33), HUMTH01 (TC11) and HUMVWFA31 (VWA). In the material obtained from series 1 (i.e. scratching with no prior cleaning of the nails) and series 2 (i.e. cleaning of the nails prior to the experiment) the debris was removed with a sharp instrument and only the DNA pattern of the person who carried out the scratching could be detected. In the 3rd series extraneous material was removed very carefully from under the fingernails to avoid contamination with DNA from the nails. In 71% of these cases DNA patterns of the person who had been scratched or mixed DNA patterns of both persons could be detected. In the experiments with postmortem skin the DNA pattern of the cadaver could be detected in all cases. These results show that in crime cases where the perpetrator has been scratched by the victim, sufficient material can be obtained from under the fingernails for DNA typing if removal of the particles is carried out with sufficient care.

DNA↗

PubMed1992

Population genetics and forensic efficiency data of 4 AMPFLP's.

Family studies were carried out in a population sample from north west Germany using 4 amplifiable VNTR polymorphic systems D1S80 (MCT118), ApoB, D17S30 (YNZ22) and COL2A1. Separation was carried out in polyacrylamide gels and visualised using silver staining. In family studies (n = 30) no evidence of new mutations was found. The population study of unrelated individuals (mothers and putative fathers) showed that all 4 systems were highly polymorphic and similar to other population studies. The combined exclusion chance was calculated to be approximately 99% and the combined discrimination index 1.5.10(-4). The Hardy-Weinberg equilibrium was checked by forming groups of alleles and no significant deviations could be found in all systems.

Alleles↗

PubMed1992

DNA extraction from mixtures of body fluid using mild preferential lysis.

A modification to the DNA extraction method "preferential lysis" (Gill et al. 1985) is proposed which can be applied to DNA mixtures of vaginal cells and spermatozoa. In mixtures with a low sperm content the further loss of sperm DNA caused by the extraction can be avoided by using "mild preferential lysis". Amplification by PCR (polymerase chain reaction) then yields sufficient DNA to be able to identify both components in the mixture.

Body Fluids↗

PubMed1992

Some technical parameters influencing the precision and accuracy of fragment size determination for RFLP's.

A comparison was carried out between 3 computer-assisted systems for the estimation of DNA fragment length: (1) the "Digitab" system (developed at our institute), (2) the FBI analysis system (FBI Quantico, USA) and (3) the BioImage system (Waters/Millipore, USA). Both the FBI system and the BioImage system were found to be much more precise than the manual Digitab system. In an additional experiment, a possible influence of the field strength on the "accuracy" of fragment size measurement was checked. Lowering the field strength to approx. 1V/cm led to a statistically significant increase in the measured fragment size.

Computer Systems↗