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Biomedical subjects

P Betz

Publications and source records attributed to P Betz.

At least 19 recordsLinked to original sources

Hypoxic changes in Purkinje cells of the human cerebellum.

The significance of both Purkinje cell numbers and various neuronal changes for the diagnosis and timing of hypoxic-induced brain lesions was investigated in tissue samples from the cerebellar cortex of 52 individuals with a history of acute or prolonged cerebral hypoxia/ischemia before death. Furthermore, the area of the Purkinje cell somata (PC size) was measured using an automatic image processing and analysis system (LEICA QWin). Significantly reduced numbers of Purkinje cells (<6 cells/unit length of 1 mm) and a decreased portion (<50%) of intact Purkinje cells could be detected in individuals with a period of resuscitation of at least 2 h after acute circulatory arrest. Average cell numbers of less than 4 cells/unit were found in individuals who suffered from diffuse brain swelling and were ventilated for at least 3 days, as well as in individuals who died of brain death. Moreover, the Purkinje cells in these cases exhibited shrunken somata compared to the controls. Specimens that were stored at room temperature up to 30 h after removal at autopsy showed no significant autolytic changes of the Purkinje cells. After 46 h, however, reduced Purkinje cell numbers and shrunken cell bodies were found.

Adult↗

Severity and duration of mental deficiency symptoms after intravenous administration of propofol.

The severity and duration of cognitive performance capacity deficits after intravenous administration of propofol were determined using the validated psychological test procedure syndrome short test (SKT), a simple reaction test and original driving licence exam questions. The test battery was performed before, immediately after, as well as 1 and 2 h after propofol administration in 23 persons. Immediately after propofol anaesthesia, six individuals had a slight performance loss, and four subjects showed mild deficits, consistent with medium organic neuropsychologic disorder or dementia. The status of the subjects rapidly changed for the better, and 2 h after propofol anaesthesia, only one person (4%) showed slight deficits of memory and attention. Therefore, it is suggested that patients refrain from any participation in road traffic for at least 2 h after propofol anaesthesia. Driving a car should not be admitted until an interval of 6 h has elapsed.

Adult↗

Fatal impalement injury of the head due to a curtain rail.

During a dispute, a boy was injured by a curtain rail which penetrated the skull in the left frontal region and led to severe brain injury. Despite intensive medical care, death occurred 10 days later due to malignant cerebral edema. With regard to the question whether the trauma resulted from throwing or pushing, some biomechanical aspects are discussed including individual morphologic findings as well as the kinetic energy required for penetrating the skull. According to the calculated data, we conclude that the velocity necessary for penetrating could be reached by throwing the curtain rail.

Adolescent↗

Value of morphological parameters for grading of brain swelling.

This study investigated the value of both gross features and histological findings for grading of brain swelling. For this purpose, the grooving of the temporal gyri (unci) as well as the extension of the cones at the basal part of the cerebellum were measured in 42 brains obtained at autopsy. Furthermore, the distension of perivascular spaces in tissue samples from seven different regions of the brains was evaluated histologically, assisted by an automatic image processing and analysis system. In each individual, the normal range of brain weight was calculated on the basis of the body height, using the formulae by Röthig and Schaarschmidt. The difference between this calculated (normal) value and the brain weight evaluated at autopsy was considered as a reliable criterion for the grade of brain swelling. There was no statistical evidence of a positive correlation between the various parameters. Hence, it can be concluded that both gross section and histological findings are of minimal significance for grading of brain swelling.

Adolescent↗

On-site testing of illicit drugs: the use of the drug-testing device "Toxiquick".

Since 1998, driving under the influence of drugs such as amphetamine, MDMA, MDE, cannabis, cocaine, heroine and morphine is sanctioned due to Section 24a of the Road Traffic Regulations of Germany. Therefore, from December 2000 to June 2002 altogether 751 roadside tests with the immunochemical test device Toxiquick were conducted on 302 drivers (273 male and 29 female) on oral fluid samples obtained during control actions in Franconia. The results of the tests are compared to the results obtained through quantification of corresponding blood samples by GC/MS. In general, in 75% the roadside test produced correct results and therefore gave helpful assistance to the police officers into the right direction regarding drug abuse. Except for cannabinoids, the number of false negative results was relatively small, whereas false positive results ranged between 32.2% for opiates and 10.7% for benzoylecgonine.

Amphetamine↗

Development of a 13-locus PCR multiplex system for paternity testing.

In this study the development of a 13-locus multiplex-PCR system fitting the updated demands for paternity testing in Germany is described. For this purpose an existing multiplex PCR system that allows the simultaneous amplification of eight different STR loci together with the sex-specific locus amelogenin ( genRESMPX-2, Serac, Germany) was extended. Whereas some of the primers were taken from the underlying multiplex system, suitable primer sequences were chosen for the STR loci D19S433, TPOX, TH01, D16S539, D5S818, D2S1338 and FGA. Primers of loci resulting in potentially overlapping fragment sizes were labelled with the fluorescent dyes 6-FAM, JOE and NED. Reaction conditions, such as annealing temperature, concentrations of primers and polymerase or buffer conditions were optimised to obtain a robust amplification and reproducible genotype analysis for various sample sources. Full DNA profiles from single source samples were reliably typed from template DNA amounts of as low as 120 pg, suggesting a potential use of this system also in forensic casework analysis. With a mean exclusion chance (MEC) of 99.9989% and a power of discrimination (P(D)) of about 1x10(14) (Caucasians), the new multiplex PCR system provides a significant and sensitive system for forensic DNA analysis. On the basis of these studies, a commercial kit system is now provided by Serac (Bad Homburg, Germany, genRESMPX-3).

Allelic Imbalance↗

Sudden death due to a haemoglobin variant.

A previous healthy 35-year-old man was found dead in his truck. Shortly before death he merely complained of influenza-like symptoms. The histological examination revealed evidence of a massive accumulation of sickle cells in smaller blood vessels. After molecular genetic analysis, the preliminary diagnosis of "sickle cell disease" was finally changed to the diagnosis of a sickle cell trait. It is presumed that an epileptic attack which also has to be considered as a concurring cause of death, precipitated sickling of the erythrocytes and led to a fatal sickle cell crisis.

Adult↗

Neuronal apoptosis following human brain injury.

Neuronal apoptosis has been investigated in paraffin-embedded brain tissue from 103 individuals who had sustained blunt head injury by use of the in situ nick translation (ISNT) technique. In order to provide reliable data for a forensic wound age estimation, a quantitative morphometric analysis was performed. Apoptotic neuronal cells could be detected in a cortical contusion with a wound age of 45 min at the earliest and in the majority of the cases with postinfliction intervals up to 2 weeks, numerous ISNT-positive cells were found adjacent to the traumatically injured area. The presented data indicate that neuronal apoptosis peaks at about 1 day and persists for at least 22 weeks after blunt head injury. The time-dependent occurrence of apoptotic cells can contribute to a forensic timing of cortical contusions and complements other immunohistochemical parameters, especially in the early postinfliction interval.

Adolescent↗

Suicide by a power drill.

This is the report of a 62-year-old man who committed suicide by drilling through his anterior chest wall with an electric power drill. Death was caused by pericardial tamponade combined with bleeding into the pleural cavity. The skin lesion at the left hemithorax was similar to a bullet entrance wound.

Cardiac Tamponade↗

Air rifle injury with an entrance through the nose: a case report and review of the literature.

A case of attempted homicide is reported where a 31-year-old woman was shot in the left nostril with a pellet from an air rifle. The projectile channel reconstruction showed penetration of the nasal septum, the maxillary and sphenoid cavities and the dura mater, with the pellet finally lodging in the anterior cranial fossa between the sinus cavernosus and the internal carotid artery. The patient was finally discharged from hospital in a good physical condition without any neurological symptoms. Although the muzzle velocity of the air rifle was within the legal limits, the present case demonstrates the potential lethality of air weapons considering the site of entrance of the pellet.

Adult↗

Thermally induced entrance wound-like defect of the skull.

A case of death due to car fire is described where the carbonised skull of the cremated corpse showed an ovoid defect of the cranial bone. The question arose whether this formed fracture was caused by a gunshot. But the reconstruction of the cranial remains with detached parts of the tabula externa provided evidence that the suspicious defect was to be classified as an uncommon heat-induced post-mortem artefact.

Artifacts↗

Unusual craniocerebral injury caused by a pneumatic nail gun.

A man was found unconscious near a ladder in a house. After resuscitation he was brought to a hospital and X-rays of the skull showed that two 12-cm long nails had completely penetrated the cranial cavity. The nails were operatively removed and after treatment for 5 weeks, the patient was transferred to a rehabilitation centre with a decreasing hemiparesis on the left side and general deterioration and then, after an attempted suicide to a psychiatric hospital. The perforating cranio-cerebral injury from a pneumatic nail gun known to reach only low muzzle velocities is a very unusual finding.

Accidents, Occupational↗

Purification of STR-multiplex-amplified microsamples can enhance signal intensity in capillary electrophoresis.

In this study, the effect of sample purification on total signal intensities of samples amplified with genRES MPX-2 (nine-locus multiplex) prior to capillary electrophoretic analysis has been investigated. Sample purification with the Qiaquick PCR purification kit led to an increase of the relative fluorescent signal intensity by a factor of 3.8 +/- 0.8. In contrast, the application of larger sample volumes led to a decrease of signal intensities from 20% to 80%, depending on whether the samples were purified or not. In addition, increase of injection time showed a linear increase of signal intensity between 3 s and 10 s. Increasing the number of PCR cycles from 30 to 33 also led to a significant increase of signal intensities. Nevertheless, this increase greatly depended on the fragment lengths and was sometimes accompanied by the appearance of non-specific signals. In combination, optimisation of sample preparation and increase of injection time may intensify signals up to 12-fold, thereby increasing the overall sensitivity of the assay. This may be of special interest for forensic analysis of microspecimens containing limited amounts of DNA.

DNA↗

DNA analysis of fingernail debris using different multiplex systems: a case report.

A 55-year-old male nurse was accused of having introduced his fingers by force into the anus of a 20-year-old female patient. Debris from the fingernails of the suspect recovered 2 days after the incident was analysed with the VNTR locus D1S80, the triplex PCR system AmpFlSTR Blue kit, the AmpFlSTR Profiler kit and the pentaplex system genRES MPX. The D1S80 singleplex reaction revealed indications of DNA from the victim in the fingernail debris of the left hand. Using the AmpFlSTR Blue kit and AmpFlSTR Profiler, DNA alleles of the victim were found at four additional loci, while allelic drop-out was observed at five other loci. Only the pentaplex kit genRES MPX revealed alleles at all loci which could be assigned to the victim. Calculation of likelihood ratios resulted in a value of 1.4 x 10(5) using the combination of the multiplex systems AmpF1STR Blue kit and AmpFlSTR Profiler and 2.8 x 10(8) for the genRES MPX kit. This case demonstrates the high sensitivity of the new genRES MPX kit and that DNA profiling of fingernail debris is possible despite a time lapse of 2 days between the incident and recovery of the evidential material.

Adult↗

Course of glial immunoreactivity for vimentin, tenascin and alpha1-antichymotrypsin after traumatic injury to human brain.

In a total of 104 individuals who had sustained traumatic brain injury (TBI), the course of glial immunoreactivity was investigated at the injured cortical area during the first 30 weeks after the trauma, in order to provide data for a forensic wound age estimation. Glial cells were stained with antibodies against the intermediate filament protein vimentin, the extracellular matrix protein tenascin and the serine protease inhibitor alpha1-antichymotrypsin (alpha1-ACT). Injury-induced glial staining reactions could be observed, at the earliest, after a post-infliction interval of 3.1 h for alpha1-ACT, 22 h for vimentin and 7 days for tenascin.

Adolescent↗

Immunohistochemical investigations on the course of astroglial GFAP expression following human brain injury.

The course of GFAP expression by astrocytes has been immunohistochemically investigated during the first 30 weeks after human brain injury. In order to provide reliable data for a forensic wound age estimation, a quantitative morphometric analysis was performed considering the different topographic regions of the cortex as well as of the white matter. Compared to the GFAP immunoreactivity in unaltered control tissue, significantly increased numbers of GFAP positive astroglial cells could be detected adjacent to the cortical contusion from 1 day up to 4 weeks after brain injury.

Adolescent↗

Suicide in a lions' den.

The case of a young man who committed suicide in a lions' den of a zoo is presented. Special attention is paid to the injury pattern which was characterised by numerous penetrating, stab-like wounds and lesions. The remarkable circumstances and history of this incident are most likely connected to a psychological or psychiatric disorder of the victim.

Animals↗

A new pentaplex PCR system for forensic casework analysis.

In 1998 the Federal Criminal Police Office of Germany (BKA) established a central genetic database of offenders and suspects to facilitate comparisons with biological samples from future criminal offences. The five obligatory short tandem repeat (STR) loci in this database (TH01, SE33, vWA, FGA and D21S11) were co-amplified in a new PCR pentaplex analysing system together with the sex-specific locus amelogenin. Due to overlapping fragment sizes, amplification products were fluorescent dye-labelled with different colours, separated by electrophoresis and detected directly using the ABI PRISM 310 Genetic Analyzer. Reproducible and reliable results were obtained from as low as 125 pg template DNA, indicating high specificity and sensitivity of the assay. Environmental studies and enzymatic digest with DNase I revealed an excellent stability of the pentaplex system with typeable results even in cases of partially degraded DNA. Complete and reproducible DNA typing was possible in blood-stain mixtures with the minor component as low as 10%. Mean stutter peak intensities were analysed for all loci and ranged from 2.7 +/- 0.8% (TH01) to 10.6 +/- 1.6% (vWA) of the main signal intensity. Allele frequencies were determined in a North Bavarian population sample (n = 121). The combination of five systems resulted in a mean exclusion chance of 99.86% and a power of discrimination of 99.999996%. No deviation from Hardy-Weinberg equilibrium could be found.

Alleles↗