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Biomedical subjects

B Brinkmann

Publications and source records attributed to B Brinkmann.

At least 145 records · Page 8Linked to original sources
PubMed1998

Microsatellite profiles reveal an unexpected genetic relationship between Asian populations.

Allelic frequencies for up to five short tandem repeat systems (HumTH01. HumVWA, HumF13B, HumCD4, HumD2111) were analyzed in seven population samples from Asia using the polymerase chain reaction and gel electrophoresis. No deviations from Hardy-Weinberg equilibrium were observed. Two new alleles of the CD4 and TH01 loci were detected, and sequenced and their molecular structure is presented. A phylogenetic tree based on Thai, Han Chinese (from the northeast of China), Japanese, German and Ovambo allelic frequencies was constructed and demonstrates the close relationship of the Asian populations. Additionally, allelic frequency data for the VWA and TH01 systems were determined for the south Chinese minorities Bai, Dai and Qiang and for Koreans and compared with the above data. The Bai and Dai populations were clear outliers of the cluster of all other Asians, indicating an unexpected pattern of genetic heterogeneity of the Chinese nation. Two clusters of Asian populations could be established: the Koreans and Japanese together with the Han and Qiang Chinese, and, forming a separate cluster, the Bai and Dai populations.

Alleles↗
PubMed1998

Mutation rate in human microsatellites: influence of the structure and length of the tandem repeat.

In 10,844 parent/child allelic transfers at nine short-tandem-repeat (STR) loci, 23 isolated STR mismatches were observed. The parenthood in each of these cases was highly validated (probability >99.97%). The event was always repeat related, owing to either a single-step mutation (n=22) or a double-step mutation (n=1). The mutation rate was between 0 and 7 x 10(-3) per locus per gamete per generation. No mutations were observed in three of the nine loci. Mutation events in the male germ line were five to six times more frequent than in the female germ line. A positive exponential correlation between the geometric mean of the number of uninterrupted repeats and the mutation rate was observed. Our data demonstrate that mutation rates of different loci can differ by several orders of magnitude and that different alleles at one locus exhibit different mutation rates.

Adult↗
PubMed1998

Phylogenetic resolution of complex mutational features at Y-STR DYS390 in aboriginal Australians and Papuans.

Y-chromosomal short tandem repeats (STRs) are used for the study of male aspects of human evolution as well as for forensic applications and paternity testing. Both applications require an understanding of the underlying mutational mechanisms that create variability. We describe complex mutations at the substructured DYS390 STR locus in 97 natives of the New Guinea/Australian region. Sequencing of short alleles in these populations indicates multirepeat deletions. All samples are further characterized using the five additional Y-STR loci DYS19, DXYS156-Y, DYS391, DYS392, and DYS393. Phylogenetic analysis of the resulting haplotypes yields ethnically specific clusters predating the settlement of Australia and Papua New Guinea (although archaic Homo sapiens or Homo erectus lineages are absent). The phylogeny confirms that DYS390 violates the stepwise mutation model and demonstrates that the DYS390 locus mutates relatively rapidly and retains its variability after structural change.

Alleles↗
PubMed1998

Experimental arrow wounds: ballistics and traumatology.

OBJECTIVE: To provide information on the ballistics and the wounding potential of different arrows or bolts fired from different weapons and to investigate the suitability of simulant media for experimental arrow wounds. METHODS: A longbow, a compound bow, and a crossbow were used to fire a variety of modern and ancient arrows. Fresh corpses of four adult pigs (47 shots) and blocks of gelatin and soap (48 shots) were used as target media, and the resulting wound tracts were examined. The range of fire was 8 m and the velocity was recorded at a distance of 3 m (and 16 m in additional shots) by light screen devices. RESULTS: The mean velocities recorded ranged from 45 m/s (longbow) to 67 m/s (compound bow). The excellent exterior ballistics of arrows results in only a small initial decrease in velocity of O.10 to 0.18 m x s(-1) x m(-1). The penetration depths were reproducible for the same arrowhead fired into the same simulant medium but differed considerably when compared with those in soft tissue. In nonbone tissue, the penetration depth was substantial (17-60 cm) and depended on velocity and especially on the type of arrowhead. All arrows penetrated deeply into the large body cavities and injured organs as long as no thick bone had to be perforated. Flat bones such as ribs were always perforated. Extraction of arrowheads from thick bone proved to be difficult in some cases. The wounding mechanism was a combination of incision and puncture, which facilitated deep penetration of tissue and produced clean-cut wounds. CONCLUSION: Gelatin and soap are not suitable for experimental arrow wounds. Every arrow wound carries a lethal potential. The severity of the wound depends primarily on the target area and the type of arrowhead. Extraction of arrowheads from thick bone has to be performed carefully.

Animals↗
PubMed1998

DNA recommendations 1997 of the International Society for Forensic Genetics.

The DNA commission of the International Society for Forensic Haemogenetics (ISFH) has over the years published a series of documents providing guidelines and recommendations concerning the application of DNA polymorphisms to problems of identification. This latest report provides recommendations relating to the nomenclature of short tandem repeat system (STR) typing systems which are at the forefront of systems used at present by forensic scientists and are likely to remain so for the immediate future.

Alleles↗
PubMed1997

Backspatter from experimental close-range shots to the head. II. Microbackspatter and the morphology of bloodstains.

Backspatter is the ejection of biological material from a gunshot entrance wound against the line of fire. Backspatter of blood was investigated experimentally in transverse gunshots to the heads of calves (n = 9) from shooting distances of 0-10 cm. The resulting bloodstains were documented on white paper placed horizontally 60 cm below the impact site. The morphology of bloodstains and the distribution of microstains (diameter < 0.5 mm) is reported. The number of microbackspatter stains per gunshot varied between 39 and 262 and the maximum travelling distance was 69 cm while the vast majority of micro-droplets accumulated between 0 and 40 cm. The direction a single droplet can take comprises every possible angle between the most tangential ones to the skin surface. Microstains exclusively were circular to slightly oval. The morphology of macrobackspatter stains (diameter > 0.5 mm) varied from round to elongated with circular, drop-like and stains in the form of exclamation marks predominating. Small macrostains (0.5-4 mm) made up more than 90% of the macrostains and no systematic relationship between distance travelled and size of the stains could be established. The necessity of appropriate lighting and magnification in the investigation of surfaces for backspatter is stressed because many microstains are located in the proximity of the entrance wound where the firearm and the shooting hand are located in cases of close-range shots.

Blood Stains↗
PubMed1997

[Identification of tissue samples in suspected accidental specimen interchange].

When there is a possibility that tissue samples have been interchanged, DNA analysis of the histological specimens can be carried out to correctly assign the specimens to a patient. The use of polymerase chain reaction enables results to be obtained even from degraded DNA in formalin-fixed and paraffin-embedded samples.

Adolescent↗
PubMed1997

Reaction patterns in selected lymphatic tissues associated with sudden infant death (SID).

In 50 cases of sudden infant death cervical, paratracheal and lung hilar lymph nodes, the thymus and the spleen were investigated by histology and immunohistochemistry (CD 20, 21, 45RO). The cases were divided into 3 groups based on autopsy findings including extensive histology: A --without pathological changes (N = 12), B --with minimal to intermediate inflammation (N = 23) and C --with severe inflammation (N = 15). In accordance with previous results the frequency of "pathological" lymph node changes, such as paracortical lymphoid hyperplasia and variegated hyperplasia of the pulp increased from group A to group C. The B-cell antigens reacted accordingly. A pronounced lymphodepletation of the thymus as a sign of a long lasting stimulation of the T-cell system was also observed increasingly from group A to C. In summary, in none of the cases results obtained were indicative of a defect of the T- or B-cell system. The results in group A seem to indicate that changes in the reaction pattern of the lymphoid tissues could be a more sensitive method of detection of early stages of inflammation than local histology.

Humans↗
PubMed1997

Sequence polymorphism at the tetranucleotide repeat of the human beta-actin related pseudogene H-beta-Ac-psi-2 (ACTBP2) locus.

The tetranucleotide repeat polymorphism in the human beta-actin related pseudogene H-beta-Ac-psi-2 (ACTBP2) locus has become a widely used short tandem repeat (STR) system in paternity testing and human identification. The discrimination index of this locus has been reported to be as high as 99.65%. To study the overall variability of this locus, 222 alleles were sequenced in our laboratory. Here, we report the sequences of the 102 different alleles observed. In addition to the length polymorphism, up to ten different sequence variants for single fragment lengths have been detected.

Actins↗
PubMed1997

Prior exposure of the entrance wound region from clothing is uncommon in firearm suicides.

According to an old rule still in use, gunshot suicides will rarely shoot through the clothing but will pull it aside to bare the skin. Thus, a bullet defect in the clothing would be an indicator for homicide or an accident. A total of 138 clearly defined gunshot suicides were analysed with regard to this topic. The thorax, which is commonly covered by textile, was the target for 27 suicides (19.5%). Of these 27 persons, 25 had fired through the clothing and 2 had placed the muzzle directly on the exposed skin, which represents a relative frequency of only 7%. Special features such as thick clothing or an affected state of mind did not appear to influence this behavior. Consequently, the perforation of textile does not suggest homicide or an accident - it is not applicable as a criterion for distinguishing different modes of death. Only in the rare cases when a gunshot victim is found with intact clothing covering the entrance wound can this finding be interpreted as an indication for suicide.

Clothing↗
PubMed1997

Laceration of the thoracic aorta from a .22 lr bullet.

A gunshot wound (.22 long rifle) to the chest including perforation of the aorta ascendens is presented. The small wound tract in soft tissue was characteristic for this type of ammunition and did not show any special peculiarities. However, arterial injury was not restricted to two small perforations, as expected in the light of previous wound ballistic findings. Three large longitudinal ruptures (3.0-4.5 cm in length and two of them independent of the perforations) additionally occurred, which led to rapid exsanguination. This extraordinary extent of vascular injury can be explained by perforation of the artery during the ventricular ejection phase, which causes a considerable dilation of the aorta analogous to a windkessel. The pre-existing dilation enables intraluminal temporary cavitation to have an "explosive" effect despite the high elastic tolerance to the vessel wall. The importance of tissue characteristics in gunshot wounds in general and the possible role of temporary cavitation inside the vessel in vascular gunshot wound production in particular are stressed.

Adult↗
PubMed1997

The expression of P-selectin in inflammatory and non-inflammatory lung tissue.

An initial attachment of leucocytes to blood vessel walls is mediated by selectins. A feature of adhesion mediated by P-selectin is the "rolling" of leucocytes on the endothelium. The time dependent expression of p-selectin in lung tissue was investigated in five groups of cases with different causes of death: carbon-monoxide and cyanide intoxication (n = 11), drowning (n = 5), hanging (n = 9), pneumonia (n = 13) and polytrauma with blunt thorax trauma (n = 14). In paraffin-embedded archival specimens immunostaining was achieved using an adapted APAAP-immunoperoxidase technique together with a wet autoclave method. P-selectin detection was scored by a semiquantitative method evaluating the intensity and incidence of positively stained endothelial cells. The distribution pattern of endothelial P-selectin of blood vessels in cases of pneumonia and septic shock were heterogenius and weak. In one case with lung contusion (survival time 3 h) moderate infiltrates of granulocytes were found near to septal and subpleural hemorrhages. In these inflammatory areas the positive endothelial immunostaining of small vessels was often weaker than in other lung segments or compared to the intensely stained platelets in corresponding vessels.

Carbon Monoxide Poisoning↗
PubMed1997

Genetic variation at five STR loci in subpopulations living in Turkey.

Five short tandem repeat (STR) systems HumVWA, HumTH01, HumCD4, HumF13B and HumFES were investigated in 2 subpopulations living in Turkey (Laz Turks and Kurds). The population genetic data were compared to a Turkish population sample from the Adana area. A closer genetic relationship was found to the Laz Turks than to the Kurdish sample which was also confirmed by phylogenetic tree reconstruction with seven populations from three major ethnic groups (Caucasian, Asian and African). In contrast to the Laz and Adana populations the Kurdish sample showed relatively low heterozygosity values and deviations from Hardy-Weinberg equilibrium in four of the five systems.

Alleles↗
PubMed1997

Multiple gunshot suicides: potential for physical activity and medico-legal aspects.

Out of 138 clearly defined gunshot suicides which were autopsied, 11 persons (8%) fired two or more gunshots to the body. From these 11, 5 cases involved 2 gunshots to the head where the bullets fired first had missed the brain. The trajectories were restricted to the chest in three cases and a combination of gunshots to the head and chest including two perforating heart wounds without immediate incapacitation occurred in three more cases. Reliable incapacitation is based on physiological effects (tissue disruption) and can only be achieved by decreasing the functioning capability of the CNS. This can be accomplished by direct disruption of brain tissue or indirectly by cerebral hypoxemia from massive bleeding. Targets of immediate incapacitation are restricted to certain CNS areas and targets of rapid incapacitation include the heart, the (thoracic) aorta and the pulmonary artery. Other major blood vessels and major organs (lungs, kidneys, liver, spleen) constitute targets of delayed incapacitation. This general classification can be derived from the literature and is illustrated by the cases presented. A thorough post mortem can exclude or quantify the potential for physical activity. Typical features of single gunshot suicides such as contact shots, classical entrance wound sites and soot/backspatter on a hand also occur in multiple gunshot suicides.

Adult↗
PubMed1997

Unusual self-inflicted injuries simulating a criminal offence.

A total of 14 cases with self-inflicted injuries intended to simulate a criminal offence are reported. Typical characteristics of self-infliction such as superficiality, localisation at the anterior aspect, parallel course or avoidance of areas with high sensitivity to pain are substantiated by most of the cases analysed. However, the majority of cases also comprised atypical features including large hematomas of the extremities, a gaping cut wound, lip laceration, hematoma of the eyelids, concussion of the brain, large burn injuries and signs of bonding. Therefore, atypical injuries, which are either found in isolation or in combination with typical injury patterns, cannot exclude self-infliction. Initially, most "victims" did not intend to report the matter to the police but the persons whose affection was to be obtained made the report. Psychopathological motivations are predominant but rational motives such as attempted insurance fraud also occur.

Adolescent↗