Michel Durigon

Organ weight in 684 adult autopsies : new tables for a Caucasoid population

The weights of normal organs were retrospectively culled for the years 1987-1991 from 684 forensic autopsy cases. All the subjects were Caucasoid adults who died of external causes and showed no pathological changes. The weights of the following organs were available: the heart, the right and the left lung, the liver, the spleen, the pancreas, the right and the left kidney and the thyroid gland. The external parameters used for statistical correlation were the age, the height, the body weight and the body mass index (BMI) of the deceased. The weight of all the organs was shown to correlate with at least one external parameter, with the exception of thyroids in females. Organ weights decreased with age except for the heart and the thyroid, and increased in relation to body height and/or BMI. Except for the heart, the organ weight showed a better statistical correlation with the body height than the BMI. These updated tables of organ weight were compared with the data collected in previous studies. Such tables have to be regularly updated by pathologists in order to keep organ weight as a good criterion to be used in post-mortem diagnosis.

Analysis of 418 cases of sexual assault.

The aim of the study was to describe victim, assailant, assault characteristics for sexual assault victims according to the time between the last sexual assault and the examination, and to provide descriptive data on medico-legal findings. The study was based on 418 examined victims of sexual assault during the year 1998. Victims were referred from investigating police authorities. All examinations were performed with the use of colposcopy by physicians with special training in forensic medicine. Two groups of victims were defined:a first group of victims examined in emergency within 72 h after the last sexual assault;a second group of victims examined after 72 h. About 86% of the cases were female victims. The mean age of the cases of the first group was 22.4 years. Conversely, 76% of the victims examined after 72 h were under the age of 15 years. Vulnerability was present in 31% of the cases examined in emergency, including disabled and pregnant victims. Sexual assault happened once in 87% of the cases of the first group and in 64% of the cases of the second group. The victims home was the most frequent place of sexual assault (35% of the cases of the first group and 56% of the cases of the second group). The assailant was a stranger in 51% of the cases of the first group. In the second group of the victims, the assailant was a family member in 58% of the cases (the father in 30% of the cases). There was a single assailant in the majority of the cases for the two groups. Threats were used by the assailant in 66% of the victims examined in emergency and in 33% of the cases of the second group. The type of sexual assault was penetration in the majority of the cases for the two groups. Vaginal, oral and anal penetration was respectively involved in 55, 23 and 13% of the cases of the first group. General body trauma was found in 39.1% of the cases examined in emergency and in 6.3% of the cases of the second group. Genital trauma occurred in 35.7% of the cases of the first group and in 19.5% of the cases of the second group. Hymenal, vulvo-vaginal and anal lesions were respectively found in 11, 20 and 7% of the cases examined in emergency. Toxicological analysis was performed in 14.3% of the cases examined in emergency. In 47% of the tested cases, drug was detected. Cytology was performed in 61.5% of the cases examined in emergency. Detection of spermatozoa was found in 30.3% of these cases. Our study has shown that sexual assault victims had different characteristics according to the time between the sexual assault and the examination. Public health campaigns against sexual abuse and rape as well as medical management of the sexually assaulted victims should adapt to the needs and the characteristics of these two different populations of victims.

Y-STR DNA amplification as biological evidence in sexually assaulted female victims with no cytological detection of spermatozoa

Identification of spermatozoa is the biological evidence most often sought in specimens from rape victims. Absence of spermatozoa usually terminates biological investigations, and the victims testimony can be contested. We assessed the utility and reliability of PCR amplification using Y-chromosomal STR polymorphisms in specimens from female victims of sexual assault with negative cytology. One hundred and four swabs without spermatozoa detected by cytology were collected from 79 alleged sexually assaulted female victims and amplification of Y-STR and of amelogenin was performed.Overall, Y-chromosome was detected and evidenced sexual penetration in 28.8% of swabs. In the population of victims examined more than 48 h after the sexual assault, Y-STR were still evidenced in 30% of the cases. These results show that swabs should be taken from victims for Y-chromosome DNA typing even after long delays between sexual assault and medical examination.

Multiplex amplification of mitochondrial DNA for human and species identification in forensic evaluation

We describe a method combining in a single-round polymerase chain reaction amplifications of both cytochrome b and hypervariable D-loop mitochondrial DNA allowing species determination and individual human identification. Following the amplification step, amplicons are first screened on an agarose gel. The presence of only one band indicates that the sample is nonhuman, while the presence of two bands indicates a human origin. Subsequent DNA sequencing of the hypervariable D-loop region DNA allows for individual human identification as the presence of cytochrome b fragment does not interfere with the analysis. Similarly, further species determination on the basis of the phylogenetically variable cytochrome b gene is possible by sequencing of the cytochrome b DNA fragment.

DNA genotyping of unbuffered formalin fixed paraffin embedded tissues

Formalin-induced DNA degradation was studied at different fixation times (3, 7, 16 and 32 days) each on 10 formalin fixed paraffin embedded tissues (FFPET) stored for 15 years at room temperature. The four different extraction protocols used in this study showed that Chelex100 extracts performed the best at 3 and 7 days of formalin fixation (DFF) (with regard to the quantity and the quality of the DNA). However, Qiamp extracts showed better results for long sized alleles, as well for single polymerase chain reaction (PCR) amplifications after 16 and 32 DFF, as for multiplex PCR at shorter fixation times. DNA degradation is expressed by the size of the amplified alleles, only 100 bp templates surviving after 32 DFF (AMG locus). Single locus amplifications (CD4 and FES/FPS alleles) performed better than multiplex PCR (ProfilerPlus), with nearly 100% positive results at 7 DFF. In both types of amplifications, the success rate decreased proportionally with the time of formalin fixation and, consequently, with the size of the required DNA template.

Homicidal and suicidal sharp force fatalities: Autopsy parameters in relation to the manner of death

A retrospective, comparative study was carried out on 118 sharp force fatalities, including 70 homicides and 48 suicides, and covering a 22-year period from 1986 to 2008. The objective was to identify relevant parameters that may be used to distinguish between these two manners of death. The following parameters were analysed: age, gender, number of wounds, type of wounds, anatomical sites of the wounds, presence of wounds affecting bones or cartilage, the longitudinal axis of stab wounds located at the anterior part of the trunk, Injury Severity Score (ISS) and associated traumatic injuries. Our statistical analyses revealed several relevant parameters that may help differentiate the two manners of death. Homicide victims were younger than those who had committed suicide. Homicide cases showed associated stab and cut wounds, whereas suicide cases predominantly showed isolated cut wounds. Wounds located at the head, limbs, hands, nape of the neck, or back were predictive of a homicide, whereas wounds located solely at the anterior parts of the trunk, neck, or forearms were predictive of a suicide. The presence of bone or cartilage wounds was predictive of a homicide and their absence was predictive of a suicide. A vertical longitudinal axis of stab wounds located at the anterior part of the trunk was predictive of a homicide whereas a horizontal axis was predictive of a suicide. ISS was found to be significantly higher in homicide cases than in suicide cases. The presence of defensive or violence-associated traumatic wounds was predictive of a homicide whereas the presence of hesitation-associated wounds or the absence of associated traumatic wounds was predictive of a suicide.

Usefulness of Systematic Histological Examination in Routine Forensic Autopsy

Abstract:  The forensic community does not agree on the need to perform histological examination at forensic autopsy. The aim of our study was to determine the usefulness of systematic standard histology in forensic autopsies. A prospective study was carried out on 428 autopsy cases for which standard histological examination was systematic. Mechanism of death not shown by gross anatomic findings was discovered by histology in about 40% of the cases. Cause of death was established by only histology in 8.4% of the cases. Microscopic findings affected the manner of death in 13% of the cases. Histology provided complementary information about prior medical condition of the deceased in about 49% of the cases. Traumatic lesions were better documented by histology in about 22% of the cases. According to the results of our study, systematic standard histology for the main organs should be used in routine forensic autopsies.

Frequency of bone/cartilage lesions in stab and incised wounds fatalities

A retrospective study was carried out on 58 fatalities due to stab or incised wounds. The frequency of bone or cartilage lesions was analysed according to the number of wounds, the circumstances of death and the anatomical site. Our findings showed that bone/cartilage lesions were present in about 53% of the cases. Cartilage lesions were more frequent than bone lesions. The mean number of wounds in the group with bone/cartilage lesions was statistically higher than the mean number of wounds in the group without lesions (P=0.0068). The main cause of death was thoracic injury in the groups with and without bone/cartilage lesions. In case of skeletal remains, only bone or cartilage lesions allow to diagnose stab or incised wounds. The discovery of these lesions, often of small size, justifies a complete and careful examination of skeletal remains with the help of stereomicroscopy.

Skeletal Remains Presumed Submerged in Water for Three Years Identified Using PCR-STR Analysis

We describe the successful identification of the remains of a saponified body found in a dam by typing of nuclear DNA. Whereas DNA extracted from soft tissues yielded negative PCR results, DNA extracted from the bone by a slightly modified Qiagen procedure allowed the typing of sex (AMG locus) and of 10 additional STR loci. An identity document was found belonging to a man missing for 3 years and comparison of the results to the DNA profiles of his son and wife confirmed the identity. The longest delay reported until now for successful nuclear DNA genotyping after immersion in river water was 18 months. This case demonstrates a delay of up to 3 years.

Influence of ballistic and autopsy parameters on the manner of death in case of long firearms fatalities

A retrospective study was carried out on 132 fatalities due to gunshot wounds secondary to long firearms. One group of suicide (n=72) and one group of homicide (n=60) were statistically compared regarding age and sex of the victim, number of shots, range of fire, direction of the projectile(s), anatomical distribution of entrance sites, weapon and ammunition types and the nature of eventual associated traumatic lesions. The frequency of suicide was higher when the victims age increased. Females constituted about 43% of the homicide victims and about 8% of the suicide victims. 51.5% of the homicide victims and about 10% of the suicide victims had sustained more than one gunshot wound. Close range was respectively found in 53.5% of the homicide cases and in all suicide cases. Most of the suicide cases (85% of the cases) showed typical entrance sites. Entrance sites in the limbs and lateral or posterior wall of the chest were only encountered in homicide cases. Associated traumatic lesions were found in about 23% of the homicide cases and in 18% of the suicide cases. In case of suicidal gunshots to the left chest, both upwards and downwards directions, and also both right-to-left and left-to-right directions can occur. From 22 suicide cases showing entrance wound in the mouth, a downwards direction was found in only one. This study underlines the importance but also the limits of the autopsy findings (including direction of the projectile(s) related to the entrance site) for giving an indication of the manner of death (homicide vs. suicide).