Nanoscale potassium sensing based on valinomycin-anchored fluorescent gold nanoclusters.

Gold nanoclusters are a smart platform for sensing potassium ions (K+). They have been synthesized using bovine serum albumin (BSA) and valinomycin (Val) to protect and cap the nanoclusters. The nanoclusters (Val-AuNCs) produced have a red emission at 616 nm under excitation with 470 nm. In the presence of K+, the valinomycin polar groups switch to the molecule's interior by complexing with K+, forming a bracelet structure, and being surrounded by the hydrophobic exterior conformation. This structure allows a proposed fluorometric method for detecting K+ by switching between the Val-AuNCs' hydrophilicity and hydrophobicity, which induces the aggregation of gold nanoclusters. As a result, significant quenching is seen in fluorescence after adding K+. The quenching in fluorescence in the presence of K+ is attributed to the aggregation mechanism. This sensing technique provides a highly precise and selective sensing method for K+ in the range 0.78 to 8 µM with LOD equal to 233 nM. The selectivity of Val-AuNCs toward K+ ions was investigated compared to other ions. Furthermore, the Val-AuNCs have novel possibilities as favorable sensor candidates for various imaging applications. Our detection technique was validated by determining K+ ions in postmortem vitreous humor samples, which yielded promising results.

Effect of CYP2D6, 2C19, and 3A4 Phenoconversion in Drug-Related Deaths.

Molecular autopsy is a very important tool in forensic toxicology. However, many determinants, such as co-medication and physiological parameters, should be considered for optimal results. These determinants could cause phenoconversion (PC), a discrepancy between the real metabolic profile after phenoconversion and the phenotype determined by the genotype. This study's objective was to assess the PC of drug-metabolizing enzymes, namely CYP2D6, 2C19, and 3A4, in 45 post-mortem cases where medications that are substrates, inducers, or inhibitors of these enzymes were detected. It also intended to evaluate how PC affected the drug's metabolic ratio (MR) in four cases. Blood samples from 45 cases of drug-related deaths were analyzed to detect and determine drug and metabolite concentrations. Moreover, all the samples underwent genotyping utilizing the HaloPlex Target Enrichment System for CYP2D6, 2C19, and 3A4. The results of the present study revealed a statistically significant rate of PC for the three investigated enzymes, with a higher frequency of poor metabolizers after PC. A compatibility was seen between the results of the genomic evaluation after PC and the observed MRs of venlafaxine, citalopram, and fentanyl. This leads us to focus on the determinants causing PC that may be mainly induced by drug interactions. This complex phenomenon can have a significant impact on the analysis, interpretation of genotypes, and accurate conclusions in forensic toxicology. Nevertheless, more research with more cases in the future is needed to confirm these results.

Lead, Mercury, and Cadmium Concentrations in Blood Products Transfused to Neonates: Elimination Not Just Mitigation.

Lead (Pb), mercury (Hg), and cadmium (Cd) are identified as potent developmental neurotoxicants. Neonates are the main group receiving multiple blood transfusions. The exposure of neonates to these heavy metals (HMs) can occur through blood transfusions. This study aimed to determine the concentrations of lead (Pb), mercury (Hg), and cadmium (Cd) in various blood products (plasma, platelets, packed red blood cells (pRBCs), and whole blood (WB)) to explore the probability of concurrent exposure of these HMs and to identify the metal load per transfusion with risk assessment. Residual bloods from blood bank bags were collected after neonatal transfusion. Pb, Hg, and Cd concentrations were determined in 120 samples of blood products by inductively coupled plasma mass spectrometry (ICP-MS). Pb and Cd levels were over the normal levels in 19.2 and 5.9% of all blood units, respectively. In 35 and 0.8% of blood units, the Pb and Cd concentrations, respectively, were higher than that recommended for transfusions in premature neonates. The anticipated safe value was surpassed by 2.5% for Cd of all transfusions, primarily because of WB. However, Hg was detected only in 5.8% of all samples and their concentrations were within the normal range. The concurrent neonatal exposure to Pb, Hg, and Cd was statistically significant. Hazard quotients of Hg and Cr were >1 and Pb cancer risk was 2.41 × 10-4. To the best of our knowledge, this study is the first report examining Pb, Hg, and Cd in blood products other than WB and pRBCs using ICP-MS. This study demonstrated the exposure of neonates to Pb, Hg, and Cd during transfusion with a considerable amount of Pb. It confirms the significant concurrent exposure to the three HMs, which maximize their potential developmental neurotoxicity with a high probability of developing non-carcinogenic and carcinogenic health effects.

Metabolic ratios and SNPs implicated in tramadol-related deaths.

Tramadol (TR) metabolism is performed by polymorphic enzymes that are influenced by genetic polymorphisms. Within this scope, the study presented here aimed to describe 41 genetic variants within CYP2D6, CYP2B6, and CYP3A4 genes in 48 cases of TR-related death that may be involved in the response to TR and to assess whether there is a correlation between these genetic variants and metabolic ratios (MRs). Blood samples from 48 victims of a TR-related death were analyzed to determine the concentrations of TR and its metabolites [O-desmethyltramadol (M1) & N-desmethyltramadol (M2)] using a LC-MS/MS method. All the samples were also genotyped for 41 common CYP2D6, CYP2B6, and CYP3A4 single nucleotide polymorphisms (SNPs) using the HaloPlex Target Enrichment system. Cases with the T/- genotype (rs35742686 in CYP2D6) had significantly higher M2/M1 ratio than cases with T/T genotype and cases with the G/A genotype (rs35599367 in CYP3A4) had significantly higher MR2 (TR/M2) ratio than cases with G/G genotype. The frequency of tested SNPs which belong to CYP2D6, CYP2B6, and CYP3A4 revealed the over-presentation of 2 SNPs (rs1058172 in CYP2D6 and rs4803419 in CYP2B6) in TR overdose group, which could have toxicological implications. These results indicate these polymorphisms in CYP2D6, CYP2B6, and CYP3A4 might influence the function and could increase the risk of toxicity. However, these findings should be supported in future studies with larger groups of cases.

Sexual Harassment: Knowledge, Prevalence, Pattern, and Impacts Among Egyptian Female College Students.

Sexual harassment (SH) is an uprising problem worldwide, especially in Egypt. This study aims to determine the magnitude, patterns, and circumstances of SH among female students at Suez Canal University. A cross-sectional study was conducted on a representative female student sample (N = 644) from all the faculties using a self-administered anonymous questionnaire. The high prevalence of SH among college students in this study could be a consequence of the absence of knowledge about the legal framework. It mostly happened at all times of the day and night in the streets, and the least amount happened on the campus. Most of the harassers were younger than 20 years old and strangers. The majority of harassed females and surrounding people displayed negative reactions. None of the harassed females notified the authorities. The majority blamed men, and half claimed the SH act was due to the absence of religious principles. Moreover, the ignorance of the majority is with Egyptian law against SH. Both psychological and social impacts are significantly experienced by the harassed females. Thus, it is urgent to establish an institutional program (e.g., psycho-educative sessions during classes and peer training) or national awareness campaigns. Such programs and trainings aim to increase the awareness of students about the SH legal framework and how to deal with such acts, either as a victim or a witness, and how to provide the needed psychological assistance.

In the case of extensively putrefied bodies, the analysis of entomological samples may support and complement the toxicological results obtained with other alternative matrices.

Entomotoxicological analysis is not part of routine toxicological analysis. This work aims to present two cases to illustrate the potential of entomological samples as complementary matrices to identify substances in cases of advanced putrefaction. (Case#1) A woman wasexhumed after 14 months to ascertain the exact cause of death. She died after six weeks of hospitalization because of intestinal ischemia followed by multiorgan failure. (Case#2) The corpse of a woman, known to have a psychiatric disorder, was discovered in her apartment. The state of decomposition of the body was consistent with a post-mortem period of several weeks (approximately 6 weeks). Toxicological investigations were performed in the biological and entomological samples of case#1 (hair, adipocere, brain, and pupae) and of case#2 (hair, bone, flies, and pupae) using liquid chromatography with high-resolution mass spectrometry and tandem mass spectrometry detection methods. In case#1, several drugs and metabolites were detected. In particular, the pupae analyses allowed the objectification of morphine administration, whereas morphine was only found in adipocere, but not in hair nor in brain. In case#2, the pupae analyses allowed the detection of three metabolites of quetiapine, and the flies analyses allowed the detection of valpromide, which was only detected in hair. In conclusion, the pupae and flies analyses in these two cases complemented the results obtained in the other alternative biological samples, which may guide hypotheses about the possible causes of death. Nevertheless, additional data and case reports would be of benefit to assess the value of entomotoxicology in routine forensic investigations.

Substance Use among Adolescents: A Retrospective Study (2017-2018) in the Toxicology Unit, University Hospital of Lille, France.

Research on adolescent substance use is of utmost importance. Using local toxicological data, both prevalence and pattern of substance use (SU) and substance-related death (SRD) can be assessed to design effective prevention programs. A retrospective study of toxicology investigations of all adolescents referred to the medico-legal section of the Toxicology Unit of the University Hospital of Lille, France, for a 2-year period from 2017 to 2018. In the total sample of 1961 cases, adolescents accounted for 3.3% of the cases (n = 65). Among the adolescents, 16.9% were aged 10−14 years and 83.1% were aged >14−19 years. About 69.2% were males. Less than 70% of all presented adolescents used substances. More than two-thirds (74%) of positive detections were male. Illicit substances (43%) were the most detected substance followed by alcohol (20%) and prescription substances (20%). Tetrahydrocannabinol (THC) was extremely common as it was found in 29% of all adolescents. Cocaine and amphetamines were detected in 13.8% of total tested adolescents. Polysubstance use was common between alcohol and THC and among males. About one-third of deaths were due to substance use. About 54% of SRD was associated with polysubstance detection. It is recommended that illicit substances, ethanol, and prescription substances are targeted for testing among adolescents in order to provide appropriate prevention.

Tramadol-Related Deaths: Genetic Analysis in Relation to Metabolic Ratios.

Tramadol (TR) metabolism is mainly dependent on the enzymatic activity of CYP2D6, which is controlled by genetic polymorphisms. Individuals are classified as poor (PMs), intermediate (IMs), extensive (EMs) or ultrarapid metabolizers (UMs) according to their genotype or phenotype. The determination of the metabolic phenotype for CYP2D6 can be of utmost importance in forensic and clinical contexts that involve TR intake. The present study aimed to describe CYP2D6 genetic variants in cases of TR-related deaths and to assess which metabolic ratio(s) (MRs) would allow to determine CYP2D6 phenotype without having to perform genetic analyses. Forty-eight postmortem blood samples were selected from TR-related death cases previously analyzed in a forensic context in North of France between 2013 and 2019. Initial available data included blood concentrations of TR and its two main metabolites (M1 & M2) determined using an LC--MS-MS method. TR metabolism was expressed as various MRs comprising TR/M1, TR/M2 and M2/M1. After DNA extraction, sequencing was used for genetic variant detections that affect CYP2D6 activity/expression. In the present study, the allelic variants with the higher frequency were CYP2D6*1 (68%), followed by *4 (21%). The most frequent phenotype is EMs (59.6%), followed by IMs (23.4%), PMs (12.8%) and UMs (6.4%). There was no significant correlation between each calculated MR and the genotypically predicted phenotypes, except for M2/M1 which appears related to the PM phenotype. The observed distribution of CYP2D6 genetic variants in this TR-related death population was similar to that found in the general Caucasian population. The present study displayed that the blood M2/M1 ratio could be the best-correlated TR MR to the PM phenotype, and could thus be used in forensic contexts where genetic analyses are not possible or poorly informative. For the other phenotypes, especially the UM phenotype, genetic analysis appears to be the only reliable method to predict the CYP2D6 phenotype.

Substance abuse among children.

Substance abuse (SA) among children is a recognized challenge for policymakers and law enforcement and has life-threatening consequences owing to the impact on the children's development and the consequent increase in vulnerability. This work outlines several important issues related to SA among children: (1) SA prevalence including onset, common examples, extent, and spectrum of SA; (2) the presence of new psychoactive substances, which are rapidly spreading worldwide with limitations regarding their prevalence, detection, and interventions; (3) street children and their recruitment in drug supply; (4) SA and substance use disorder pathways, risk and protective factors for the development of SA; (5) SA consequences in the case of early initiation, including deaths; and (6) current preventive interventions for the pediatric population. In conclusion, this challenge requires consistent and unremitting attention in order to execute effective prevention programs with continuous re-evaluation of the situation.

Applications of forensic entomology: overview and update.

Despite the great strides made in fundamental and applied research, forensic entomology is constantly growing and considered to be an interconnected scientific discipline. Indeed, there is shortage in the available scientific literature in comparison to many other legal and biological subjects as well as in the number of forensic entomologists. The main goal of this work is to clarify the importance of forensic entomology by demonstration of their applications; it can provide important information about when, where, and how a particular death occurred. It can also identify the assailant and/or the victim or might highlight in some cases, the victim's state of neglect prior to death. It also aimed to demonstrate the impact of new emerging technologies; encouraging researchers to further pursue this line of research. More multidisciplinary research would lead to better understanding and identifying novel research areas. Consequently, that could meet scientific and legal expectations.

Postmortem identification of spermatozoa on human skin based on fluorescent monoclonal antibody method.

Identification of semen residues has relevant consequences, especially for what concerns the ascertainment of possible sexual assault. Forensic scientists usually focus on the vaginal swab for semen detection despite the importance of semen deposition on the skin. Postmortem identification of spermatozoa on putrefied human skin is still under investigation. Sperm Hy-Liter™ is an antibody technique, used to identify human spermatozoa heads in forensic stains. This approach has the potential to eliminate spermatozoa visualization problems in a traditional method. Therefore, the present study aimed to compare between the traditional method (light microscope and staining via hematoxylin/eosin) and a fluorescence-based method (by using fluorescent microscope and staining via Sperm Hy-Liter™) for postmortem identification of spermatozoa on human skin at different time intervals. A piece of human skin was divided into three strips; the first was a negative control while semen was spread on the second and third skin strips. The first (control) and second groups were stained by hematoxylin/eosin for light microscopic examinations. The third group was stained by Sperm Hy-Liter™ then examined under fluorescent microscope. The results revealed that the spermatozoa identifiability was up to 110 days based on Sperm Hy-Liter™ and fluorescent microscope, while it was up to 12 days via using hematoxylin/eosin and light microscope. Further studies are recommended in order to verify not only the accuracy of the used method on skin of dead victims but also to evaluate persistence of spermatozoa on different body sites and fabrics.

Identification of age and sex based on knee radiography.

The identification of age and sex constitutes the cornerstone in biological profile determination. Identification of age and sex depends mainly on ossification of bones and sexual dimorphism respectively. The knee is an ideal site for assessment of 3 epiphyseal unions at the same time. Moreover, patella is a compact bone that could display sexual dimorphic characters. A total of 479 anteroposterior and lateral radiographs of the knee were reviewed retrospectively in subjects aged between 10 and 20 years old; 255 males and 224 females. Epiphyseal union was scored as stage 0 (non-union), stage 1 (beginning union), stage 2 (active union), stage 3 (recent union) or stage 4 (complete union). Three measurements on patella (maximum height, width, and thickness) were used to determine sex by univariate and multivariate discriminant analysis. Intra- and inter-observer variability were excellent. Mean age increases with each stage of union and also varies between sexes. The relationship between the three knee epiphyses and chronological age was strong for both sexes. It has been noted that union occurs at an earlier age in the Chinese population. As expected, epiphyseal union in females occurred earlier than males. Interestingly, the present study exhibited that stage 2 of the three knee epiphyses occurs in males earlier than their female counterparts by 6 months. Compared with previous published data, the patella in this study was small and wide. The best discriminant functions for sex determination were 73% which is obtained by the combination of 2 measurements only; height/thickness and height/width. Thus, the patella is of limited value as sex indicator. Further studies on different areas within China are recommended in order to verify not only the accuracy of the used methods but also to enable evaluation of different ethnic groups. Further studies based on different anatomical regions for assessment of sex are also encouraged.

COII "long fragment" reliability in characterisation and classification of forensically important flies

INTRODUCTION: Molecular identification of collected flies is important in forensic entomological analysis guided with accurate evaluation of the chosen genetic marker. The selected mitochondrial DNA segments can be used to properly identify species. The aim of the present study was to determine the reliability of the 635-bp-long cytochrome oxidase II gene (COII) in identification of forensically important flies. MATERIAL AND METHODS: Forty-two specimens belonging to 11 species (Calliphoridae: Chrysomya albiceps, C. rufifacies, C. megacephala, Lucilia sericata, L. cuprina; Sarcophagidae: Sarcophaga carnaria, S. dux, S. albiceps, Wohlfahrtia nuba; Muscidae: Musca domestica, M. autumnalis) were analysed. The selected marker was amplified using PCR followed by sequencing. Nucleotide sequence divergences were calculated using the K2P (Kimura two-parameter) distance model, and a NJ (neighbour-joining) phylogenetic tree was constructed. RESULTS: All examined specimens were assigned to the correct species, formed distinct monophyletic clades and ordered in accordance with their taxonomic classification. Intraspecific variation ranged from 0 to 1% and interspecific variation occurred between 2 and 20%. CONCLUSIONS: The 635-bp-long COII marker is suitable for clear differentiation and identification of forensically relevant flies.

Reliability of long vs short COI markers in identification of forensically important flies.

AIM: To compare the reliability of short and long cytochrome oxidase I gene fragment (COI) in identification of forensically important Diptera from Egypt and China. METHODS: We analyzed 50 specimens belonging to 18 species. The two investigated markers were amplified by polymerase chain reaction (PCR) followed by direct sequencing. Nucleotide sequence divergences were calculated using the Kimura two-parameter (K2P) distance model and neighbor-joining (NJ) phylogenetic trees. RESULTS: Although both tested fragments showed an overlap between intra and interspecific variations, long marker had greater completeness of monophyletic separation with high bootstrap support. Moreover, NJ tree based on the long fragment clustered species more in accordance with their taxonomic classification than that based on the short fragment. CONCLUSION: In dipterous identification, it is recommended to use the long COI marker due to its greater reliability and safety.