Biomedical subjects

S Hummel

Publications and source records attributed to S Hummel.

At least 19 recordsLinked to original sources

PubMed2000

[Determining the severity of venous insufficiency with duplex sonography].

OBJECTIVE: The volume flow in the common femoral vein (SV) as a representative parameter of the venous hemodynamics of the leg can be measured using duplex-sonography. A direct correlation between the SV-data and the clinical grade of the venous disease was postulated. PATIENTS/METHODS: SV was measured in 36 patients (62 limbs) with complete varicosis of the long saphenous vein, 18 patients (24 limbs) with an incomplete form of varicosis and 40 healthy persons (78 limbs). The assessments were done under standardized conditions. We found a significant difference of the SV-data between the three groups. RESULTS: The values of SV were significantly elevated in varicosis compared with the healthy limbs. The data determined in legs with complete varicosis were significantly raised compared to incomplete varicosis. The means were 0.38 l/min in complete varicosis, 0.26 l/min in incomplete varicosis and 0.13 l/min in healthy limbs. During a time course of 30 minutes the values were stable. CONCLUSIONS: The results demonstrate a significant correlation between the measured SV data and the grade of venous disease.

Adult↗

PubMed2000

Molecular sex identification of stillborn and neonate individuals ("Traufkinder") from the burial site Aegerten.

The study reconstructs the sex ratio of 121 stillborn and neonate individuals from the early modern burial site Aegerten, Switzerland. The immature individuals, who were not baptised before death, were buried along the walls of the church. To perform a molecular sex identification, bone samples from the infants were collected from different skeletal elements. Ancient DNA (aDNA) was isolated by a combination of automated phenol/chloroform extraction and precipitation with silica powder. A combination of manuell Chelex extraction and purification kit was also used to perform an extraction. Finally, the aDNA extracts were amplified with a primer system that amplifies a part of the amelogenin gene located on the human sex chromosomes. The morphometrical sex determination of the children suggests a large disproportion of female individuals (about 60%). This finding was compared to PCR-based amplification results. In contrast, the results of the molecular sex identification were a high proportion of male individuals. Looking at these results, it should be noted that the high mortality of male individuals during the last months of pregnancy and during the first month after birth is in accordance with the natural sequence of death also found in recent populations.

Female↗

PubMed2000

Evaluation of morphological sex determinations by molecular analyses.

The study presents an evaluation of morphological sex determinations of adult skeletal individuals based on traits of the ossa coxae and the cranium. The evaluation criterion was genetic analysis of the amelogenine gene, which represents parts of the X- and the Y-chromosome (Mannucci et al. 1994). The study was carried out on 33 human skeletons from an early modern burial site in Lower Saxony. In this skeletal series, 88% of the morphological sex determinations matched the genetic sex. The percentage of matches was further improved, if only those morphological determinations were taken into account that were classified as unambiguous by a self-evaluation. In the reverse case, a significant number of non-matching determinations (33%) resulted from those cases in which a sex determination still seemed possible but was classified as "ambiguous" in the self-evaluation. At least within this skeletal series, no clear connection could be detected between the number of matching results and the presence or absence of the ossa coxae. This might be due to a strong cranial dimorphism within this particular skeletal series.

Adult↗

PubMed2000

Megaplex DNA typing can provide a strong indication of the authenticity of ancient DNA amplifications by clearly recognizing any possible type of modern contamination.

Recent experiments revealed the perfect applicability of megaplex typing by autosomal short tandem repeats (STRs) to degraded DNA. The advantages of megaplex approaches lie in reduced amounts of sample material that are necessary and in remarkable time saving. Furthermore, megaplex typing clearly recognizes possible contaminations and thus has a large potential for indicating authenticity in ancient DNA analysis. This is demonstrated by three examples in which various types of contaminations could clearly be identified as such and even traced back to their origin. This would have been impossible using control samples, due to the sporadic nature of these types of contaminations.

Artifacts↗

PubMed2000

STR-genotyping of archaeological human bone: experimental design to improve reproducibility by optimisation of DNA extraction.

The analysis of degraded DNA with the help of short tandem repeat loci (STRs) is an important source of information both in forensic casework and in the anthropological context. The reproducibility of STR-genotyping of highly degraded or "ancient" DNA can be reduced by the generation of artifacts during PCR amplification. The frequency and amount of these artifacts--allelic dropout and the generation of shadow bands--are related to the quality and quantity of the extracted DNA amplified in a PCR reaction. Therefore, one important strategy to increase the reproducibility of STR-genotyping of samples containing degraded DNA is the optimisation of the DNA extraction.

Archaeology↗

PubMed2000

Ancient DNA-typing approaches for the determination of kinship in a disturbed collective burial site.

Several DNA-typing approaches are applied for identification and kinship analysis. Autosomal Short Tandem Repeat (STR) typing produces the genetic fingerprint that is unique to an individual. Y-chromosomal STR typing identifies individuals of the same paternal lineage, and sequence analysis of the hypervariable region of the mitochondrion can identify maternally related individuals. The combined approach of these DNA-typing methods allows the determination of kinship even in complex collective burial situations. In a bronze age collective site, the typing methods were tested for applicability to ancient DNA. For each approach, results were obtained, leading to the conclusion that the determination of kinship is achievable.

Bone and Bones↗

PubMed2000

STR allelic frequencies in a German skeleton collection.

Chromosomal DNA was isolated from bones from a German skeleton collection (Goslar, 18th century) and detected by PCR. Nine microsatellite regions were amplified by multiplex reactions using the AmpFlSTR Profiler Plus kit and analysed to obtain their allelic distribution. A statistical evaluation of the results revealed no allelic differentiation between the historic sample and a modern German one at each locus.

Alleles↗

PubMed2000

Ancient DNA fragments longer than 300 bp.

It is widely assumed that ancient DNA (aDNA) extracts contain no authentic templates longer than 300 bp. Here we present results which show that fragments of up to 800 bp in length can be reproducibly amplified from aDNA extracts. The amplification involves the short tandem repeat (STR) locus HUMVWA31A. Authentication of the amplified fragments is carried out by measures of expectancy.

DNA↗

PubMed2000

Reconstruction of kinship by fecal DNA analysis of orangutans.

Genetic analysis is a useful tool for assigning biological relationships. Thus, it will improve genetic management of wild animal populations and breeding colonies. Kinship analysis will give new insights into the behavior, sociobiology and genetic management of orangutans. In this study, chromosomal DNA from orangutan (Pongo pygmaeus ssp.) was extracted from excrements. Feces samples were screened for up to nine microsatellite markers from related zoo populations of orangutans (Pongo pygmaeus ssp.) kept at the Zoological Garden Berlin and the Zoological Garden Heidelberg, Germany. Family structures are documented in the "International Studybook of the Orangutan" (Perkins 1995) and the "Europäisches Erhaltungszucht Programm 1998" (Becker 1998). To examine whether human short tandem repeat loci (STR) are suitable for the reconstruction of kinship in orangutans, nine STRs, commonly used in forensic studies and the amelogenin system, were amplified in a multiplex-PCR approach (AmpFlSTR Profiler Plus). We were able to show that five of the nine human autosomal STRs in question amplified successfully in orangutans. Thus, we could reconstruct kinship structures of the Berlin and Heidelberg populations.

Amelogenin↗

PubMed2000

Palaeogenetic analysis of (pre)historic artifacts and its significance for anthropology.

The possibility of isolating ancient DNA (aDNA) from all kinds of (pre)historic anthropogenetic artifacts opens new perspectives. This study applies palaeogenetic techniques to three anthropological issues: 1. Palaeodiet. DNA sequences from organic residues in vessels identify Precolumbian Aztec diet. 2. (Pre)historic husbandry and economic structures. aDNA data can reveal the species and the genetic evolutionary stage of animals and plants and show the manner and the extent of their growth, cultivation, or domestication. 3. Production techniques, use, and functionality. Identification of the plant or animal source of an archaeological find can reveal the use or the function of the find. Examples from a Celtic "sausage-end" and an Aztec "eye salve" are given.

Archaeology↗

PubMed2000

Trace analysis of endogenous and exogenous biomolecules from archaeological skeleton materials.

An analytical procedure was developed for the determination of pharmacologically active substances in archaeological skeleton materials. In comparative model studies, added ("spiked") test biomolecules of varying chemical behaviours were extracted from sample matrices and percentage of the analytes recovered were estimated using gas chromatography/mass spectrometry (GC/MS) or high performance liquid chromatography (HPLC). For the sterols and steroids studied, several organic solvents were appropriate. Extraction yields for the alkaloid nicotine, representing non-endogenous basic agents, were increased by alkalizing with triethylamine or by extracting with a two-phase system consisting of an alkaline aqueous and an organic layer (toluene). The flavonol quercetin was extractable only in an acidic environment. In a screening for native biomolecules using GC/MS, nicotine was identified in individual samples, in addition to lipophilic substances such as the endogenous cholesterol and its degradation products and two phytosterols which may have migrated into the bones from the surrounding soil.

Alkaloids↗

PubMed1999

Optimized DNA extraction to improve reproducibility of short tandem repeat genotyping with highly degraded DNA as target.

The reproducibility of short tandem repeat (STR) genotyping of highly degraded DNA is often reduced due to artifacts generated during polymerase chain reaction (PCR) amplification. The frequency and amount of these artifacts are related to the quality and quantity of the DNA amplified. Consequently, the aim of this investigation was the optimization of DNA extraction to increase the reproducibility of STR genotyping of samples containing highly degraded DNA. Starting from a standard extraction protocol, systematic variation of individual parameters resulted in optimized protocols for three categories of ancient human bone material (different degrees of DNA degradation) and a consensus protocol for the extraction of a broad range of ancient DNA preservation states.

DNA↗

PubMed1999

Ancient DNA profiling by megaplex amplications.

Simultaneous amplification of nine human short tandem repeat (STR) DNA sequences and the amelogenin locus allows reducing to an absolute minimum the amount of sample material that is necessary for genetic identification or kinship analysis. Valuable remains can be studied this way without any visible damage, as is demonstrated by typing the DNA of a tooth root from the Saxon warrior Widukind, who died about 1200 years ago. The broad applicability of the megaplex approach is shown by typing bone and teeth specimens ranging from a few months to 3000 years of age employing AmpFISTR Profiler Plus. Additionally, megaplex STR typing is the method of choice for proving the authenticity of molecular results derived from ancient degraded DNA.

Amelogenin↗

PubMed1999

DNA preservation: a microsatellite-DNA study on ancient skeletal remains.

To determine the effect of environmental factors on the preservation of DNA, archeological teeth of approximately similar age but greatly differing site milieu were examined for DNA content. The complex relational system of locational milieu of the samples was reduced to its essential and, at the same time, easily measurable factors. These are temperature, humidity, pH value, the geochemical properties of the soil, the amount of postmortal organic substances and the general degree of microbial infestation in the respective soil. The relative DNA content in the samples was established by determining the rate of successful polymerase chain reaction (PCR) amplifications. Differences in quantity and quality of the results are attributed to the respective prevailing environmental factor or to the respective storage conditions. Dryness, low temperature and absence of microorganisms favors the preservation of DNA. The bioapatite of bones and teeth, like the DNA, are preserved under neutral or slightly alkaline conditions. Brief storage at room temperature does not affect the amount of amplifiable DNA but does affect the reproducibility of the results. Long storage outside a lab freezer reduces the amount and the reproducibility of DNA amplifications in ancient specimens.

Bone and Bones↗

PubMed1999

DNA profiling of orangutan (Pongo pygmaeus) feces to prove descent and identity in wildlife animals.

In this study, orangutan (Pongo pygmaeus ssp.) DNA was extracted from excrements, obtained from individual zoo populations. To examine whether human short tandem repeat loci (STR) are suitable for the reconstruction of kinship in orangutans, nine STRs, commonly used in forensic studies in man and the amelogenin system, were amplified in a multiplex polymerase chain reaction (PCR) approach. Five of the nine human autosomal STRs in question amplified successfully in orangutans. Furthermore, the experiments revealed that orangutans possess allele distributions comparable to humans in these systems. Fragment length determination allowed kinship structures to be reconstructed.

Animals↗

PubMed1999

Proving the authenticity of ancient DNA by comparative genomic hybridization.

In PCR-supported amplification of ancient, degraded DNA, contamination with contemporary DNA can lead to false-positive results, which frequently give rise to discussions in which the mere existence of ancient DNA is doubted. Our confirmation of ancient DNA using comparative genome hybridization (CGH) eliminates these doubts. Unlike PCR methods, CGH requires no amplification of the DNA to be analyzed if adequate amounts of specimen DNA is used. Thus, false results traceable to contaminations are practically ruled out. The examples provided here prove the authenticity of ancient DNA for a 250-year-old and a 3,000-year-old sample. At the same time, the CGH of ancient DNA offers the chance to gain insight into the pattern of DNA degradation and to monitor the preservation of certain chromosomal segments.

Chromosomes, Human↗

PubMed1999

Amplification of Y-chromosomal STRs from ancient skeletal material.

The adaptation to ancient DNA analysis of a Y-chromosomal STR (short tandem repeat) multiplex comprising the four STR systems DYS19, DYS390, and DYS389I/II shows the suitability of Y-chromosomal STR typing on ancient human remains. A new primer site for the system, DYS389I/II, resulting in products shortened by 94 bp, was chosen to serve the special needs of amplification of ancient DNA. For the first time, it was possible to amplify STR loci of the Y chromosome from historical and prehistorical bones of up to 3000 years old.

Bone and Bones↗

PubMed1998

Tree-pollen allergy is efficiently treated by short-term immunotherapy (STI) with seven preseasonal injections of molecular standardized allergens.

The efficacy and tolerance of short-term immunotherapy (STI) by seven preseasonal injections of tree-pollen allergens (ALK7 Frühblühermischung) was investigated in a double-blind, placebo-controlled, multicenter study with 111 rhinoconjunctivitis patients. Nasal and bronchial symptoms simultaneously analyzed, and nasal symptoms as a single end point, but not the overall score of nasal, bronchial, and conjunctival symptoms, showed a significantly lower increase with STI during birch-pollen exposure (both P=0.033, n=105, Mann-Whitney U-test). However, a selective analysis with patients from centers with high recruitment figures (n> or =10 patients, n=29 STI, n=32 placebo) showed a significantly lower increase of nasal, bronchial, and overall symptom score (STI 11.0 vs placebo 18.0, P=0.001, U-test). STI had equidirected effects on conjunctival, nasal, and bronchial symptoms analyzed as multiple end points, although conjunctival symptoms were not significantly different as a single end point. The seasonal increase in drug use was reduced by 62% in the STI group compared with placebo (P=0.032, t-test). Specific IgG4 increased only after STI (P<0.001); IgE was not significantly different. Eosinophil cationic protein remained unchanged with STI, but significantly increased with placebo in the pollen season (P=0.003). STI was well tolerated. In conclusion, STI was shown to be efficacious and safe for the treatment of patients with tree-pollen rhinoconjunctivitis.

Adolescent↗