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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

PCR-based typing of DNA extracted from cigarette butts.

Limited genetic marker information can be obtained from saliva by typing by conventional serological means. Thus, the application of PCR-based DNA typing methods was investigated as a potential approach for typing genetic markers in saliva. DNA was isolated from 200 cigarettes smoked by 10 different individuals (20 cigarettes per individual) and from 3 cigarette butts recovered from 2 crime scenes (adjudicated cases) using a Chelex 100 extraction procedure. The amount of recovered human DNA was quantified by slot-blot analysis and ranged from approximately less than 2-160 ng DNA per cigarette butt for the 200 samples, and 8 ng, 50 ng, and 100 ng for the cigarette butts from the adjudicated cases. The DNA was successfully amplified by the polymerase chain reaction (PCR) for the HLA-DQ alpha locus (99 out of 100 samples) as well as for the variable number of tandem repeat (VNTR) locus D1S80 (99 out of 100 samples). Amplification and typing of DNA was successful on all samples recovered from the crime scenes. The results suggest that PCR-based typing of DNA offers a potential method for genetically characterizing traces of saliva on cigarette butts.

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↗
PubMed1990

[Tablet residues in gastrointestinal contents? A polarization microscopy screening method for rapid evaluation at the autopsy table].

When tablet residues are found in the gastrointestinal tract during autopsy, this does not only indicate the possible presence of intoxication, but may also provide indications with the regard to the kind of intoxication (e.g. suicide) if the amount of tablets is considered. If tablets have already dissolved and thus large portions can no longer be detected with the naked eye, a definitive appraisal with regard to the presence of tablet residues is often difficult or even impossible on the autopsy table. A polarization microscopic screening method is described which enables identification of characteristic tablet auxiliary substances (maize starch, sodium carboxymethyl starch, microcristalline cellulose or sodium carboxymethyl cellulose) to be identified immediately and simply in the gastrointestinal contents. It also enables a rapid orientative screening for tablet residues in glasses found or the fluid these contained as well as in aspirated material and vomit. If the active agent of the tablet can be detected by chemical toxicology, the polarization microscopic diagnosis of abundant tablet auxiliary substances is compatible with intake of large amounts of drugs, which makes self-administration highly probable.

Drug Overdose↗
PubMed1990

[Changes in skeletal muscles in death caused by hypothermia].

The review of 32 deaths resulting from hypothermia yielded mostly the common pathological findings as bright red livores, haemolytic frost marks of the skin and Wichnewski erosions of the gastric mucosa. In addition the muscle system of the body core (musc. ileopsoas) showed hemorrhages and histologically necrosis of its fibres in form of segmental and discoid sarcoplasmatic alteration. These changes are a quite specific sign of death due to hypothermia, as far as mechanical injury can be excluded. For best result however a special autopsy technique and an appropriate histological staining are advisable.

Adult↗
PubMed1990

[Midazolam--a forensic problem drug?].

Benzodiazepine derivates can cause transient global amnesia even when administered in therapeutical doses. As amnesia seems to be more frequent than supposed, it is relevant for traffic medicine. We shall discuss forensic cases in which Midazolam amnesia was suspected with special attention to the interpretation of toxicological data.

Accidents, Traffic↗
PubMed1989

[Formation of a "crow's foot pattern" in the smoke residue in homicide by forehead gunshot injury].

We report a "crowsfoot-like" pattern in the smoke marks around the entrance of a close-range bullet wound in the center of the forehead; the weapon in this homicide was a revolver. This pattern only occurs if the facial muscles that form expression are completely contracted at the moment the shooting occurs and if the victim expects the event. The wrinkles gather around the entrance of the bullet, and this wound pattern may indicate that the shot was expected by the victim and represent a piece of the mosaic that might help clarify the circumstances in a case.

Brain Injuries↗
PubMed1989

[Craniocerebral trauma in a newborn infant--precipitous labor or a fall after birth].

The autopsy of a newborn child that was found wrapped up in a plastic bag revealed a biparietal fracture of the skull. Only after knowing all circumstances it was possible to explain the origin of this fracture. A plausible reconstruction was possible after the inspection of the scene, the autopsy and by taking into consideration the statement of the mother. Thus it is could be decided that the death of the newborn child occurred by an accident while an infanticide, birth injury or labor precipitate causing the fracture was excluded.

Accidental Falls↗
PubMed1987

Barbiturate poisoning and gastrointestinal propulsion.

Anaesthetic doses of pentobarbitone (50 mg/kg) were found to inhibit gastric emptying and gastrointestinal transit in the rat. Gastric emptying was more profoundly suppressed than gastrointestinal transit. Phenobarbitone (150 mg/kg) had a similar effect. Since pentobarbitone and phenobarbitone also blocked the peristaltic reflex in the isolated small intestine of the guinea-pig, it would appear that the inhibitory effect of anaesthetic doses of barbiturates on gastrointestinal motility is mainly due to a direct action on the digestive tract. Together with the observation that considerable amounts of phenobarbitone were found in the stomach of an intoxicated patient 3 days after drug intake, these results might indicate that gastric lavage should also be considered in the treatment of protracted barbiturate poisoning.

Animals↗
PubMed1986

[Fatal epidural hemorrhage after a 2-week interval].

This in a report on a 15-year old school girl who sustained a skull fracture after a fall. Apart from an initial syncope and signs of commotio cerebri no severe cerebral deficiencies were apparent. She died suddenly soon after her discharge and 2 weeks after the accident. The officially confirmed cause of death (based on autopsy by order of a court) was an epidural hemorrhage. This hemorrhage originated from a reruptured traumatic pseudoaneurysma of the arteria meningea media. The morphological findings are presented. The legal problems are discussed especially in the light of recently re-introduced conservative treatment of epidural hemorrhage diagnosed by computed tomography.

Adolescent↗
PubMed1985

Parathion and gastrointestinal transit in the rat.

The possibility of in vivo or post-mortem acceleration of gastrointestinal transit was investigated in the rat after sublethal or lethal doses of the insecticide parathion. Parathion did not change gastrointestinal transit time before or after death in the poisoned rat.

Animals↗