Medicine, Science and the Law最新文献

The changes in the internal environment of the body after death due to lack of oxygen result in certain morphological changes in the blood cells. This study tests the hypothesis that after we take out blood from live individuals and store it in-vitro there will also be an anoxic environment which will result in morphological changes like what happens in-vivo after death. The idea was to simulate the anoxic in-vivo condition in-vitro, by storing the blood sample taken from live persons in a vial and to look for sequential changes with respect to time and to develop a scale to see how this scale of morphological changes correlates with the time since death in post-mortem samples collected. Blood samples preserved in EDTA was taken from 186 live volunteers and 60 cadavers whose exact time of death was known. Blood smear was made and stained with Leishman stain and observed under an oil immersion microscope. Cells were classified into four stages based upon the nuclear changes - normal, pyknosis (shrunken nucleus), vacuolated and fragmented nucleus and complete lysis. The sequence of change remained same in both in-vitro stored samples and cadaver in-vivo samples. But the changes in the cadaver samples were appearing rapidly as compared to the in-vitro stored samples. It is hard to completely refute the hypothesis that in-vitro and cadaver conditions would be similar, and changes exhibited would also be similar based on this single study. Further studies with much larger sample size need to be conducted to completely refute or prove the above hypothesis. Also, other co-existing factors which can affect morphology of the cells should be considered.

This is the first study to examine mental health issues, substance use, and suicide risk among incarcerated women in Paraguay, aiming to identify factors associated with these conditions, such as age and medical history. A cross-sectional study was conducted on 215 incarcerated women. Participants were assessed using the Symptom Checklist-90-Revised (SCL-90-R) to evaluate mental health symptoms, Columbia Suicide Severity Rating Scale (C-SSRS) for suicide risk, and MULTICAGE CAD-4 to measure alcohol and drug addiction. The chi-square test and odds ratios were applied to identify associations between mental health outcomes and associated factors, with a significance level of 5%. Our findings revealed that 40% of the participants had some level of suicide risk. Alcohol consumption was reported by 36.7% of the participants; 59.5% screened positive for alcohol-related problems, and 45.6% used drugs, with 73.5% screening positive for drug-related problems. Depression (23.7%) and somatization (21.4%) were the most frequent dimensions of mental health symptoms. Younger women (aged 18-38 years) were significantly more vulnerable to hostility, psychoticism, and interpersonal sensitivity. The study also identified a significant relationship between substance use and suicide risk, with substance users more likely to exhibit suicidal tendencies. Our study highlights the urgent need for integrated mental health and substance use interventions in Paraguayan prisons, especially for younger women who are at higher risk of mental health disorders. Suicide prevention strategies should be prioritized by incorporating mental health and substance use treatments. Further research is needed to explore these issues longitudinally and in different prison environments.

Y-Chromosomal short tandem repeat polymorphism (Y-STR) plays an important role in forensic practice due to its unique patrilineal inheritance pattern. Y-STRs of male individuals from different regions differ in terms of relevant forensic parameters and phylogenetic relationships. Although a large number of scholars have reported studies on the Y-STRs of different groups in different regions, there are still insufficient data on the Y-STR population genetics of the Lisu population in Kunming. To enrich the relevant research, a total of 801 healthy male participants from the Lisu ethnic group in Kunming, Yunnan Province, Southwest China, were included in this study. The DeepTyper Y41 Human DNA Typing Kit was used to co-amplify the 38 Y-STR loci. Haplotypes and associated forensic parameters were analyzed. Multidimensional scaling and neighbor-joining (N-J) phylogenetic tree were performed to complete the phylogenetic analyses based on the genetic distance (Rst) values in the Y-STR Haplotype Reference Database. 656 haplotypes were observed among the 801 male individuals. The value of haplotype diversity, haplotype matching probability and discrimination capacity was 0.9991, 0.0022 and 0.8190, respectively. Phylogenetic analyses showed that the Kunming Lisu population was closer to the Yunnan Han, the Liangshan Yi and the Yunnan Dai in phylogenetic relationship. Overall, this study enriches the research on population genetics on Y-STRs in Chinese ethnic minorities. The data can be utilized for population genetics and forensic research, specifically in the construction of genealogical databases.

When there are no witnesses, no substantive material evidence, no plausible motive, and, moreover, nothing beyond speculation to indicate that a crime has even occurred, then the prosecution of suspected serial killer nurses will be difficult. It will lean heavily on statistical arguments. There are two pillars to these arguments; the first is to show, on the basis of a believed inexplicable spike of deaths and life-threatening events, that the best explanation is that of criminal activity. While identifying a cluster is an awkward statistical question, it is not the one we address here. Our focus is on the second pillar of the argument, one that aims to show the accused as the most likely culprit in the light of roster chart evidence. The basis of this evidence comes from what is judged to be an unusually high correlation of the accused's presence with the events when they took place. We show that such roster chart evidence is unreliable. A visual inspection of any chart will be misinterpreted, the reader coming to an erroneous conclusion. We consider a recent case and, via careful calculation, show that what was believed to be strong evidence of culpability is, in truth, anything but. The often heard statement "whenever something went wrong, the nurse was always there," has no basis in fact.

The estimation of late post-mortem intervals (PMIs) represents a challenge for the routine forensic pathologist's practice. Few studies have evaluated the reliability of teeth as stable and protected matrices rich in DNA. The pilot study aims to verify the feasibility of Feulgen reaction colorimetric measurement on odontoblastic cells from the dental pulp of extracted teeth as a useful tool to estimate late PMIs. Ten teeth obtained from healthy patients who underwent tooth avulsion for clinical reasons were included in the sample and crown pulps were extracted at five different PMIs (T0-baseline, 14 days, 1 month, 1.5 months, and 2 months). The PMI was assumed as the time elapsed from the tooth avulsion up to the pulp extraction. The Feulgen reaction and the colorimetric analyses with ImageJ software on odontoblastic cells of dental pulps were pursued in order to measure the residual dental DNA integrity according to the PMls. The study provides evidence for the persistence of odontoblasts up to 2 months post-mortem in a recognizable organization, hence useful in late PMIs. The method based on Feulgen reaction could be a reliable tool for estimating the late PMI, correctly distinguishing between PMI 0 and 14 days, but also between PMI 14 days and 2 months. To the best of our knowledge, the Feulgen reaction has never been applied to study the possible correlation of the dental pulp cells' integrity and the PMI. Preliminary results suggest the feasibility of the proposed method for estimating the time elapsed since death, but further research is needed.

PurposeGunshot residue (GSR) analysis is a crucial forensic application in the investigation of firearm-related crimes. This analysis traditionally relies on samples collected from the hands of suspected shooters. However, post-shooting activities such as hand cleaning can significantly diminish the presence of GSR on the hands, which compromise the use of routine sampling techniques. This study explores the potential of the hyponychium - a sheltered anatomical region beneath the free edge of fingernail - as an alternative GSR sampling site that may retain particles longer despite post-shooting hand cleaning activities.MethodsUsing six participants, samples were collected from both hands and the hyponychium following firearm discharge, with GSR particle counts analyzed via scanning electron microscopy (SEM) coupled with energy-dispersive X-ray spectrometry (EDX). Post-shooting activities including hand wiping with paper towels, wet wipes, rinsing with water, and washing with soap and water were performed to evaluate GSR persistence in the hyponychium.ResultsObtained results demonstrated that the dorsum of the right hand initially contained the highest GSR particle count. However, all post-shooting cleaning methods significantly reduced the particle numbers on the hands, with washing with soapy water nearly eliminating detectable GSR. In contrast, the hyponychium consistently retained GSR particles, albeit at reduced levels, even after washing.ConclusionFindings suggested that the hyponychium is a promising supplementary sampling site for GSR analysis, particularly when conventional hand samples are compromised by post-shooting hand cleaning methods. This alternative approach may improve analytical accuracy in cases where critical evidence might otherwise be lost.

Drowning is a leading cause of injury-related deaths among youth worldwide, often linked to inadequate supervision and ineffective guardianship. While paediatric studies have examined demographics and risk factors, little is known about how these variables interact to influence rescue likelihood. This study addresses that gap using a multivariate binary logistic regression model to assess the odds of not receiving a rescue attempt, using fatality records (n = 638) from coroners and medical examiners across Canada (2006-2016). This approach captures all known accidental fatal drownings but findings cannot be generalized to include incidents in which the individual survived. The best model explained 45.1% of the variance in rescue outcomes (Nagelkerke Pseudo R² = .451) with 84.6% accuracy. Findings revealed that age, sex, alcohol use, perimortem activity, water body type and urban/rural location significantly impacted rescue attempts. However, chronic medical conditions and general bystander presence showed no significant relationship at the bivariate level. When demographics and situational factors were considered, bystander type (with adult, minors only or alone/not witnessed) became a key model contributor for predicting rescue attempt likelihood. Teenagers (15-18 years) accounted for 33.5% of drownings, followed by toddlers (2-4 years, 21.9%) and children (5-11 years, 20.5%). Compared to infants, older children and teens faced greater risks of not being rescued, and bystander presence does not equate to capable guardianship. Open water environments posed the highest risk, with ocean drownings 7.9 times more likely to result in no rescue attempt, compared to domestic settings.