Liliana Santos

Postmortem Analyses Unveil the Poor Efficacy of Decontamination, Anti-Inflammatory and Immunosuppressive Therapies in Paraquat Human Intoxications

Background Fatalities resulting from paraquat (PQ) self-poisonings represent a major burden of this herbicide. Specific therapeutic approaches have been followed to interrupt its toxic pathway, namely decontamination measures to prevent PQ absorption and to increase its excretion from organism, as well as the administration of anti-inflammatory and immunosuppressive drugs. Until now, none of the postmortem studies resulting from human PQ poisonings have assessed the relationship of these therapeutic measures with PQ toxicokinetics and related histopathological lesions, these being the aims of the present study. Methodology/Principal Findings For that purpose, during 2008, we collected human fluids and tissues from five forensic autopsies following fatal PQ poisonings. PQ levels were measured by gas chromatography-ion trap mass spectrometry. Structural inflammatory lesions were evaluated by histological and immunohistochemistry analysis. The samples of cardiac blood, urine, gastric and duodenal wall, liver, lung, kidney, heart and diaphragm, showed quantifiable levels of PQ even at 6 days post-intoxication. Structural analysis showed diffused necrotic areas, intense macrophage activation and leukocyte infiltration in all analyzed tissues. By immunohistochemistry it was possible to observe a strong nuclear factor kappa-B (NF-κB) activation and excessive collagen deposition. Conclusions/Significance Considering the observed PQ levels in all analyzed tissues and the expressive inflammatory reaction that ultimately leads to fibrosis, we conclude that the therapeutic protocol usually performed needs to be reviewed, in order to increase the efficacy of PQ elimination from the body as well as to diminish the inflammatory process.

Mechanical characterization and constitutive modelling of the damage process in rectus sheath

The aim of this study is to characterize and model the damage process in the anterior rectus abdominal aponeurosis (anterior rectus sheath) undergoing finite deformations. The resistance of the anterolateral abdominal aponeuroses is important when planning the surgical repair of incisional hernias, among other medical procedures. Previous experiments in prolapsed vaginal tissue revealed that a softening process occurs before tissue rupture. This nonlinear damage behaviour requires a continuum damage theory commonly used to describe the softening behaviour of soft tissues under large deformations. The structural model presented here was built within the framework of non-linear continuum mechanics. Tissue damage was simulated considering different damage behaviours for the matrix and the collagen fibres. The model parameters were fit to the experimental data obtained from anterior rectus sheath samples undergoing finite deformations in uniaxial tension tests. The tests were carried out with samples cut along the direction of the collagen fibres, and transversal to the fibres. Longitudinal and transverse mechanical properties of human anterior rectus sheath are significantly different. The damage model was able to predict the stress-strain behaviour and the damage process accurately. The error estimations pointed to an excellent agreement between experimental results and model fittings. For all the fitted data, the normalized RMS error ε presented very low values and the coefficient of determination R(2) was close to 1. The present work constitutes the first attempt (as far as the authors know) to present a damage model for the human rectus sheath.

Sexual abuse of children. A comparative study of intra and extra-familial cases

The existing data suggest that individuals experiencing intra-familial abuse are affected more significantly than those experiencing extra-familial abuse. This study aims to identify possible differences between these types of abuse. A retrospective study was performed based on medico-legal reports related to children suspected of being sexually abused (n=1054). The results revealed that 40.2% of the suspected abuses were intra-familial and were significantly different than extra-familial cases with respect to the following: (a) the complainants were younger; (b) their relationship to the alleged abuser was closer; (c) the alleged abusers had higher rates of previous sexual abuse; (d) the suspected abuses were less intrusive physically; (e) there was less physical but more psychological violence; (f) the delay between the last abuse and the medico-legal examination was greater; and (g) there were fewer physical signs and DNA evidence (none in the great majority of cases). These results highlight aspects of intra-familial abuse that have been identified as factors influencing the severity of its consequences - physically, these instances of abuse were less intrusive but psychologically they were more intrusive than extra-familial abuse. This justifies the use of different strategies in the diagnosis and support for victims within the family.

Biomechanical Properties of Vaginal Tissue in Women with Pelvic Organ Prolapse

Background/Aims: To compare biomechanical properties of vaginal tissues between women with and without pelvic organ prolapse (POP) and investigate factors that may influence these properties. Methods: Forty patients submitted to POP surgery and 15 non-POP cadavers were evaluated. The tissue was excised from anterior and posterior middle third vagina. The biomechanical properties considered were stiffness (E) and maximum stress (Smax), and they were evaluated by means of uniaxial tension tests. Results: POP patients were associated with higher values of E (13.1 ± 0.8 vs. 9.5 ± 0.7 MPa; p < 0.001) and Smax (5.3 ± 0.5 vs. 3.2 ± 0.9 MPa; p < 0.001) in the anterior vaginal wall compared to the posterior wall. In contrast, non-POP women presented lower values of E (6.9 ± 1.1 vs. 10.5 ± 1.0 MPa; p = 0.01) and Smax (2.6 ± 0.4 vs. 3.5 ± 0.4 MPa; p = 0.043) in the anterior wall. The occurrence of POP was the only independent predictor of higher values of E and Smax in anterior vaginal samples (p = 0.003 and p = 0.008, respectively). Women with severe anterior vaginal prolapse presented higher levels of E and Smax in the anterior sample compared to those with lower POP stages (p = 0.001 and p = 0.01; respectively). Conclusion: Women with POP present significant changes of biomechanical properties in the vagina.

Genetic profiles and sex identification of found-dead wolves determined by the use of an 11-loci PCR multiplex.

A previously described canine-specific 9-STR multiplex, now including two markers for sex determination, was tested for the genotyping of 23 wolves from Northern and Central Portugal. The samples were collected at necropsies and presented varying states of preservation. Complete profiles were obtained in 74% of the samples, partial profiles in 22% and one completely null profile. This survey revealed 15 alleles not previously described in dogs, distributed among 6 STR loci. It is shown that this genotyping system, previously tested in domestic dogs, can be reliably used for obtaining complete genetic profiles in wolves with a matching probability of 2.45 x 10(-9) and compatible sex identification, even in sub-optimal samples. Moreover, a population structure analysis using the observed genotypes revealed that this multiplexed 11-loci panel may potentially be used for discriminating between wolves and dogs.

Identification of mtDNA Lineages of Sus scrofa by Multiplex Single Base Extension for the Authentication of Processed Food Products

A genetic method to identify the breed of origin could serve as a useful tool for inspecting the authenticity of the increasing number of monobreed foodstuffs, such as those derived from small local European pig breeds. Mitochondrial DNA (mtDNA) is practically the only reliable genomic target for PCR in processed products, and its haploid nature and strict maternal inheritance greatly facilitate genetic analysis. As a result of strategies that sought to improve the production traits of European pigs, most industrial breeds presently show a high frequency of Asian alleles, while the absence or low frequency of such Asian alleles has been observed in small rustic breeds from which highly prized dry-cured and other traditional products are derived. Therefore, the detection of Asian ancestry would indicate nonconformity in Protected Denomination of Origin products. This study presents a single base extension assay based on 15 diagnostic mtDNA single nucleotide polymorphisms to discriminate between Asian and European Sus scrofa lineages. The test was robust, sensitive and accurate in a wide range of processed foodstuffs and allowed accurate detection of pig genetic material and identification of maternal ancestry. A market survey suggested that nonconformity of products derived from Portuguese breeds is an unusual event at present, but regular surveys both in the local populations and in commercial products would be advisible. Taking into consideration the limitations presented by other methodologies, this mtDNA-based test probably attains the highest resolution for the direct genetic test for population of origin in Sus scrofa food products.

Vaginal Tissue Properties versus Increased Intra-Abdominal Pressure: A Preliminary Biomechanical Study

Background/Aims: This study aims to evaluate the pelvic floor (PF) tension response during simulated increased intra-abdominal pressure (IAP) and the vaginal biomechanical properties. Methods: A 3-dimensional computational finite element model for PF was developed based on magnetic resonance imaging from a nulliparous healthy volunteer. The model was used to simulate an IAP of 90 cm H2O and to evaluate the PF stresses in the longitudinal and transversal axes. The vaginal samples were obtained from 15 non-prolapsed female cadavers. A uniaxial tensile test to obtain stiffness and maximum stress of vaginal tissue in the longitudinal and transversal axes was performed. Results: The simulated IAP was associated with a similar PF stress state in the longitudinal and transversal axes. The stiffness and maximum stress in vaginal tissues presented a great variability between subjects. There was no difference in the vaginal tissue elasticity (6.2 ± 1.5 vs. 5.4 ± 1.1 MPa; p = 0.592) and maximum stress (2.3 ± 0.5 vs. 2.6 ± 0.9 MPa; p = 0.692) regarding the measurements in the longitudinal and transversal axes. Conclusion: The isotropic biomechanical behavior of vagina is in agreement with the PF stress state response during increased IAP.

Pedestrian Fatalities Resulting From Train–Person Collisions

Objective: Train–person collisions have a significant impact in our society, due to their negative economic and psychological effects. This work aims to study fatalities resulting from train–person collisions in Portugal. Methods: A retrospective study was conducted based on the analysis of autopsy reports related to train–person fatalities performed in the North Branch of the National Institute of Legal Medicine and Forensic Sciences. Results: Suicide was responsible for most of the cases, and males were more often involved in train–person collisions than females. Victims, between 40 and 59 years old, were found to be involved in a high percentage (39%) of the cases, and people older than 65 accounted for a significant percentage (40%) of the accidents. No seasonality was observed in suicide cases, but a decrease in accident numbers was registered in summer. Regarding weekday and time of day, afternoon and non–rush hour were the times when most suicides were observed, whereas accidents did not showed a specific weekday or time of day, except for rush hour, during which they were more frequent. Alcohol-positive blood analysis accounting for 25% of the cases. Conclusions: Differences from other European studies were found, which may be related to the different cultures of the countries/regions, as well as to the differences in the railway systems. More extensive studies must be performed in order to develop strategies to prevent train–person collisions.