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Biomedical subjects

R Dirnhofer

Publications and source records attributed to R Dirnhofer.

At least 19 recordsLinked to original sources
PubMed1992

[Population genetic Hae III/RFLP and HLA-DQ-alpha data of a Caucasian population sample in Switzerland].

DNA from unrelated individuals (Caucasians; n = 200-271) from Switzerland were digested with Hae III and successively hybridized to the DNA probes D1S7, D2S44, D4S139, D10S28, D14S13, D17S26 and D17S79. An allele frequency distribution was determined for each locus. Furthermore, from the same individuals (n = 200) after amplification of DNA the allele and genotype frequencies at the HLA-DQ alpha locus were determined. The allele frequency distribution in Swiss Caucasians is statistically similar to American Caucasian population samples. In criminal cases a DNA-profile derived from four single-locus probes always leads to a very high value of discrimination and in paternity testing the probability of paternity always exceeds 99.9% regardless to the reference population used for biostatistical evaluation. Therefore for use in forensic analysis and paternity testing pooled caucasian databases might be used for the determination of the frequency of occurrence of a DNA-profile.

Alleles↗
PubMed1992

[Conversion of forensic paternity determination to DNA analysis].

For many years, the resolution of disputed paternity cases by genetic means relied on laboratory blood tests of red cell antigens and red cell and serum protein electrophoresis. These systems are generally characterized as lacking polymorphism and having low powers of exclusion, therefore it was necessary to use a panel of up to 23 marker systems. Over the past five years, a variety of DNA restriction fragment length polymorphism (RFLP) systems have been developed that characterize individuals at the DNA level. In this paper we describe the implementation of a Hae III RFLP system utilized in our laboratory for the resolution of disputed parentage cases as well as forensic casework. Since the analysis of highly polymorphic VNTR loci has proven to be the most powerful method to date for the determination of biological relatedness the utilization of the conventional methodologies should be completely replaced.

Adult↗
PubMed1992

[Effects of nonoxinol 9 on RFLP typing of postcoital vaginal smears].

Nonoxinol 9 effectively inactivates high titres of HIV in vitro, which suggest its use for reducing HIV-transmission via sexual intercourse. Therefore, the suggestion has been made for the treatment of sexual assault victims with a topical anti-HIV agent such as nonoxinol 9 as soon as possible after a sexual assault has occurred. From the forensic point of view it becomes pertinent to determine whether or not nonoxinol 9 would have an adverse effect on the high-molecular weight deoxyribonucleic acid (DNA) in vaginal swabs and thereby impact RFLP results. The study demonstrates that nonoxinol 9 does not have a negative effect on the ability to produce RFLP patterns. Therefore, the early administration of the topical anti-HIV agent nonoxinol 9 has to be considered as an important step in the medical treatment of sexual assault victims.

DNA↗
PubMed1991

Typing of deoxyribonucleic acid (DNA) extracted from compact bone from human remains.

The application of deoxyribonucleic acid (DNA) typing methods for the potential identification of unknown human remains was investigated. DNA was isolated from compact bone tissue from badly decomposed bodies and from known and unknown human remains, using a decalcification and ion wash procedure. Restriction fragment length polymorphism (RFLP) analysis of variable number of tandem repeats (VNTR) loci yielded results in some cases, but more often the DNA was too degraded to produce RFLP patterns. No RFLP profiles could be obtained from putrefied soft tissues. However, DNA extracted from compact bone tissue of human remains up to eleven years old was successfully amplified using the polymerase chain reaction (PCR) for the VNTR loci D1S80, D17S5, COL2A1, and APO B, as well as the HLA-DQ alpha locus. This is especially significant, since PCR results were obtained from those samples whose DNA had been degraded substantially and had yielded no RFLP patterns. All DNA types determined from the compact bone tissue from decomposed bodies whose identification had been established first by other means (and whose parents or offspring were available for typing) demonstrated mendelian inheritance of the alleles of the loci analyzed. These results suggest that amplification and typing of DNA extracted from compact bone of human remains could be useful in establishing the identity of a person, as well as in excluding possible false identifications.

Bone and Bones↗
PubMed1979

[Apparently contradictory homozygosity of gc- and esd-markers in three generations (author's transl)].

In a paternity case we found contradictory blood group antigens in the serum- and enzyme-polymorphisms Gc and EsD of the child, her mother and grandparents. A possible accidental exchange of the child could be excluded by biostatistical calculations of the probabilities of motherhood, fatherhood and parenthood, and the descent from the parents was proven in both generations. The serological findings may be explained by the concurrent existence of silent genes or of genes that cannot be determined as yet. The genetic information Gc degrees descended from the grandfather and that for EsD degrees from the grandmother. Both were transmitted from the mother to the child. Thus, the case could be cleared by statistical considerations only.

Antigens↗
PubMed1979

[Mechanical tolerance of tentorium cerebelli (author's transl)].

In some cases of accidents primary traumatic brain stem hemorrhages are seen in conjunction with lesions of the tentorium cerebelli. In order to decide, whether accelerations of the infra- or supratentorial brain tissue are actually capable of causing tentorium lesions, burst and teartests of tentorium tissue were conducted. The mean dynamic biaxial tearing force was found to be about 4 bar. This value supports the hypothesis that a main injury causing factor of the tentorium in cases without skull fracture could be the relative motion between the tentorium and the brain hemispheres. The mass of the cerebellum however seems to be insufficient to cause such injury producing deceleration forces on the tentorium.

Acceleration↗
PubMed1979

[The effect of blood-filled meshwork of arachnoid villi in connection with posttraumatic brain edema (author's transl)].

Based on the Kellie-Munro doctrine according to which the intracranial compartments--blood, brain, and CSF--are in a state of pressure and volume equilibrium, we examined if traumatic lesions of the liquor absorption passages could change the intracranial pressure (ICP). Therefore, we reviewed the arachnoid villi and granulations of patients which died as a result of head injuries. In cases of traumatic subarachnoidal hemorrhages the meshwork of arachnoid villi are filled throughout with blood. By microscopical examination we observed findings in the network of spaces of the villi like they are known in prestatic and static conditions of capillary system (clothing of erythrocytes). The pathophysiological significance of the findings, especially with regard to the dynamic of posttraumatic brain edema, is discussed.

Adult↗
PubMed1978

[Exceptional suicide of a physician (author's transl)].

A 57 years old psychiatrist committed suicide through insufflation of powder from a chemical fire extinguisher his respiratory and gastrointestinal tract. Death was due not to mechanically induced asphyxia but to asystolia. The latter disturbance is explained as a vagal reaction to trauma because of the characteristic position of the corpse at the scene and because the victim did not exhibit any signs of gas or foreign body embolism. A further point of interest in the context of trauma mechanism, is the absence of significant disruptions in spite of the high pressure (10-12 atu) developed by the extinguisher. No conclusive interpretation can be given about the psychological mechanisms behind this suicidal act. On the other side the modality of the procedure used by the victim became manifest already a few months before the critical act.

Heart Arrest↗
PubMed1978

[The enlarged diagnosis of the fatal penicillin accident. Immunehistologic demonstration of antigen-antibody complexes and of antibodies against the tubular basement membrane after administraiton of depot penicillin].

In a case of fatal penicillin allergy it proved possible at autopsy to demonstrate (by immunohistological examination of basal membranes of proximal renal tubuli) antigen-antibody complexes belonging to the penicillin (BPO) group and to an anti-penicilloyl antibody of the IgG type. In addition, complement C3 was detected. Antibodies against the basal membranes or renal tubuli were also demonstrated in material eluted from the kidney, although an inflammatory reaction ot the immunoligical changes had not yet been observed in light microscopy. It is undecided whether this discrepancy is due to the low dose of penicillin administered or the relatively short time lag between first injection and time of fatality. It is assumed that, pathogenetically, a reaction of the serum sickness type is probably involved. For etiological clarification the use of immunohistological methods in addition to serological procedures provides further indices for an antecedent sensitization to penicillin, because assay effectiveness does not decrease even after a lengthy postmortal time-lapse. On the other hand, tissues and serum for examination should be frozen at low temperatures immediately after autopsy.

Antigen-Antibody Complex↗
PubMed1977

[A fatal food poisoning caused by bacillus cereus (author's transl)].

The autopsy of a 37 year old man who had died under extraordinary circumstances showed a bromatoxism by bacillus cereus. The verification of the bacillus was possible although the man had already died 2-3 days before; and that in spite of the existence of early beginning rottenness. With the help of morphological findings the pathogenetic effect of the toxins (exotoxin and enterotoxin) of bacillus cereus is discussed. Blood cultures of the heart alone are not sufficient to prove a causal connexion between infection and death. For this purpose bacteriological examination of the organs (liver, spleen, kidney, lungs and brain) is at the same time necessary. An aseptic method, which is described in detail, is the absolute condition for useful results. The forensic value of proof of the bacteriological examination is secured and improved by an additional verification of bacteria in histological specimen coloured by Gram.

Adult↗
PubMed1977

[Concerning the development of brainstem injuries (author's transl)].

Since the etiology of traumatic brainstem lesions has not been completely clarified we tried to analyse this question from autopsy material with special consideration of the effects of rotational acceleration of the head resulting from an impact force. Seventeen cases without a skull fracture were investigated. We considered the tentorium as a suitable indicator for possible relative movements occuring between cerebral hemispheres and the cerebellum as well as the brainstem since, because of its attachment to the skull, it follows all excursions of the skull directly and simultaneously. The brain, however, due to its inertia, remains stationary in the beginning so that injuries may occur on the structures mentioned. The results of the autopsies confirmed these assumptions, for both uni- and bilateral tears as well as hemorrhages in the tentorium cerebelli were found. Associated were subarchnoid hemorrhages over the upper vermis and thin layered hematomas between the tentorium and the cerebellum. In all cases the brainstems showed both microscopic and macroscopic hemorrhages of the isthmus cerebri and in some cases of the cerebral peduncles and the cerebellar brachia conjunctiva. These hemorrhages are attributed to shearing forces and tension arising from movements between tentorium and the surrounding brain components. The mechanical effects on the brainstem and its surrounding structures at various rotational accelerations of the head (along transversal, vertical and sagital axis) are discussed. The combination of brainstem lesions with injuries of the tentorium suggests that the brainstem injury was a primary result of the impact. Finally the possible significance of rotational acceleration for brainstem injuries caused by whiplash mechanism of the head in connection with improperly used automobile safety belts or inadequate headrests is discussed.

Accidents, Traffic↗
PubMed1976

[The determination of time of death utilizing a considerable difference between urine-and blood alcohol (author's transl)].

Examining a case of death due to a subarachnoidal hemorraghe of a ruptured cerebral aneurysm the approximate time of death could only be determined by a considerable difference between alcohol contents of urine and blood. Since the urinary bladder was filled and a continuous diuresis until the moment of death could be assumed it was possible to calculate the average period of time during which the stated concentration of urine alcohol was formed, and to estimate the survival time.

Adult↗
PubMed1975

[Concerning survival time in primary hematomas of the brain-stem (author's transl)].

The autopsy on a 54-year old man, who had a motorcycle-accident 17 days before and suffered a head injury, showed a large traumatic hemorrhage in the oral pontine region. The lesion must be considered primarily traumatic because of the brain-stem symptoms which appeared immediately after the accident (immediate unconsciousness, extension spasms, miosis) the macroscopic and histological findings (proliferation around the hemorrhage, hematoidin in the centre of the hemorrhage) and the biomechanical circumstances (impact on the occiput). Furthermore, considering the clinical findings and the autopsy results, pathogenetic factors which might have produced secondary hemorrhage seem to be unlikely. It seems as if the timing of death after traumatic hemorrhage in the oral pontine region depends less on the direct lesion in these areas, but on the extension of the hemorrhage to the caudal brainstem with concomittant edema. For the differentiation between primary and secondary brainstem lesions the duration of the survival time is therefore only of relative significance.

Accidents, Traffic↗
PubMedDate not supplied

[Self-strangulation?].

A sixty year old man was found stangled to death with a part-elastic belt. As the ecchymosis, which are typically found above the mark of strangling, were missing, considerable doubt emerged at first as to the cause of death and to a suicide by strangling. Measurements of the elasticity of the instrument of strangulation, of the size of the neck and the head, as well as self-experiments aimed at reconstruction the circumstances had, in pathophysiological respect, the result of a method of self-strangulation similar to a typical hanging. The remaining circumstances also point to a suicide.

Forensic Medicine↗