Examining the use of alternative light sources in medico-legal assessments of blunt-force trauma: a systematic review.

The ability to analyze blunt-force trauma is crucial for deciphering valuable clues concerning mechanisms of injury and as evidence for medico-legal investigations. The use of alternate light sources (ALS) has been studied over the past decade, and is proposed to outperform conventional white light (CWL) during bruise assessments. In response to the growing interest of the technology worldwide, a systematic review of the literature was conducted according to the Preferred Reporting Items for Systematic Review and Meta-Analysis (PRISMA) to address the ability of ALS to detect and visualize bruising. From an initial 4055 records identified, ten studies met the eligibly criteria and were selected for this review. Evaluation also included a novel framework, referred to as SPICOT, to further systematically assess both scientific evidence and risk of bias in forensic literature. Analysis reveals that narrowband wavelengths within in the infrared or ultraviolet spectral ranges do not significantly outperform CWL in visualizing or detecting bruising. However, wavelengths within the visible spectrum, particularly 415 nm combined with longpass or bandpass yellow filters, are more effective. However, the majority of selected studies only address the sensitivity of ALS, and therefore, results may only be considered valid when the location of a bruise is known. Further investigation is required to understand the specificity of ALS, in particular how the use of topical cosmetic products, previous wounds/scar-tissue, tattoos, moles and freckles may affect detection. The ethical concern regarding the interpretation of enhanced visualized trauma should also be considered in prospect discussions prior to implementing ALS into routine practice. Nevertheless, this review finds that narrowband ALS within the visible spectrum demonstrates potential for improved injury documentation, outperforming CWL in the detection and visualization of bruising.

Postmortem CT analysis of paranasal sinuses using an experimental model of drowning.

Fluid-filled paranasal sinuses are suggested to be a valuable tool to distinguish between drowning and non-drowning postmortem, yet the mechanisms governing fluid entry remains unknown. We investigate if fluid-filled paranasal sinuses are caused by a passive influx from submersion or an active aspiration mechanism during drowning. The ovine nasal cavity and maxillary sinuses are remarkably similar anatomically to humans, and have been used for endoscopic surgical training in recent decades. We submerged 15 decapitated ovine heads from agricultural waste at a depth of 2 m in flowing water for 1, 8, and 24 h and 7 days. Paranasal sinuses were CT imaged and compared pre- and post-submersion to non-submerged controls. Furthermore, we examined the paranasal sinuses of a single homicide case of a non-drowned submerged subject. Results demonstrate that fluid passively enters the maxillary sinus postmortem in the non-drowned ovine heads following 1 h of submersion. Fluid volume was independent of submersion time and influenced by time out of water as well as handling, since volume was reduced between consecutive CT scans. In contrast to our hypothesis, the filling of the paranasal sinuses is due to passive influx of fluid from submersion rather than an active aspiration during drowning. The observation that paranasal sinuses were fluid-filled in a single medico-legal case of postmortem submersion supports the finding of passive influx. Consequently, careful interpretation of fluid-filled paranasal sinuses is required when bodies are found in water, as the finding cannot distinguish between postmortem submersion and drowning.

A probability model for estimating age in young individuals relative to key legal thresholds: 15, 18 or 21-year.

Age estimations are relevant for pre-trial detention, sentencing in criminal cases and as part of the evaluation in asylum processes to protect the rights and privileges of minors. No current method can determine an exact chronological age due to individual variations in biological development. This study seeks to develop a validated statistical model for estimating an age relative to key legal thresholds (15, 18, and 21 years) based on a skeletal (CT-clavicle, radiography-hand/wrist or MR-knee) and tooth (radiography-third molar) developmental stages. The whole model is based on 34 scientific studies, divided into examinations of the hand/wrist (15 studies), clavicle (5 studies), distal femur (4 studies), and third molars (10 studies). In total, data from approximately 27,000 individuals have been incorporated and the model has subsequently been validated with data from 5,000 individuals. The core framework of the model is built upon transition analysis and is further developed by a combination of a type of parametric bootstrapping and Bayesian theory. Validation of the model includes testing the models on independent datasets of individuals with known ages and shows a high precision with separate populations aligning closely with the model's predictions. The practical use of the complex statistical model requires a user-friendly tool to provide probabilities together with the margin of error. The assessment based on the model forms the medical component for the overall evaluation of an individual's age.

The histone H4 lysine 16 acetyltransferase hMOF regulates the outcome of autophagy.

Autophagy is an evolutionarily conserved catabolic process involved in several physiological and pathological processes. Although primarily cytoprotective, autophagy can also contribute to cell death; it is thus important to understand what distinguishes the life or death decision in autophagic cells. Here we report that induction of autophagy is coupled to reduction of histone H4 lysine 16 acetylation (H4K16ac) through downregulation of the histone acetyltransferase hMOF (also called KAT8 or MYST1), and demonstrate that this histone modification regulates the outcome of autophagy. At a genome-wide level, we find that H4K16 deacetylation is associated predominantly with the downregulation of autophagy-related genes. Antagonizing H4K16ac downregulation upon autophagy induction results in the promotion of cell death. Our findings establish that alteration in a specific histone post-translational modification during autophagy affects the transcriptional regulation of autophagy-related genes and initiates a regulatory feedback loop, which serves as a key determinant of survival versus death responses upon autophagy induction.

Mesenchymal Stromal Cell Secretion of Programmed Death-1 Ligands Regulates T Cell Mediated Immunosuppression.

Mesenchymal stromal cells (MSCs) exert broad immunosuppressive potential, modulating the activity of cells of innate and adaptive immune systems. As MSCs become accepted as a therapeutic option for the treatment of immunological disorders such as Graft versus Host Disease, our need to understand the intricate details by which they exert their effects is crucial. Programmed death-1 (PD-1) is an important regulator in T cell activation and homeostatic control. It has been reported that this pathway may be important in contact-dependent mediated immunomodulation by MSCs. The aim of this study was to establish whether MSCs, in addition to their cell-surface expression, are able to secrete PD-1 ligands (PD-L1 and PD-L2) and their potential importance in modulating contact-independent mechanisms of MSC immunosuppression. Here we report that MSCs express and secrete PD-L1 and PD-L2 and that this is regulated by exposure to interferon γ and tumor necrosis factor α. MSCs, via their secretion of PD-1 ligands, suppress the activation of CD4+ T cells, downregulate interleukin-2 secretion and induce irreversible hyporesponsiveness and cell death. Suppressed T cells demonstrated a reduction in AKT phosphorylation at T308 and a subsequent increase in FOXO3 expression that could be reversed with blockade of PD-L1. In conclusion, we demonstrate for the first time, that MSCs are able to secrete PD-1 ligands, with this being the first known report of a biological role for PD-L2 in MSCs. These soluble factors play an important role in modulating immunosuppressive effects of MSCs directly on T cell behavior and induction of peripheral tolerance. Stem Cells 2017;35:766-776.

Do cryopreserved mesenchymal stromal cells display impaired immunomodulatory and therapeutic properties?

We have recently reported that therapeutic mesenchymal stromal cells (MSCs) have low engraftment and trigger the instant blood mediated inflammatory reaction (IBMIR) after systemic delivery to patients, resulting in compromised cell function. In order to optimize the product, we compared the immunomodulatory, blood regulatory, and therapeutic properties of freeze-thawed and freshly harvested cells. We found that freeze-thawed MSCs, as opposed to cells harvested from continuous cultures, have impaired immunomodulatory and blood regulatory properties. Freeze-thawed MSCs demonstrated reduced responsiveness to proinflammatory stimuli, an impaired production of anti-inflammatory mediators, increased triggering of the IBMIR, and a strong activation of the complement cascade compared to fresh cells. This resulted in twice the efficiency in lysis of thawed MSCs after 1 hour of serum exposure. We found a 50% and 80% reduction in viable cells with freshly detached as opposed to thawed in vitro cells, indicating a small benefit for fresh cells. In evaluation of clinical response, we report a trend that fresh cells, and cells of low passage, demonstrate improved clinical outcome. Patients treated with freshly harvested cells in low passage had a 100% response rate, twice the response rate of 50% observed in a comparable group of patients treated with freeze-thawed cells at higher passage. We conclude that cryobanked MSCs have reduced immunomodulatory and blood regulatory properties directly after thawing, resulting in faster complement-mediated elimination after blood exposure. These changes seem to be paired by differences in therapeutic efficacy in treatment of immune ailments after hematopoietic stem cell transplantation.

Autologous Peripheral Blood Mononuclear Cells as Treatment in Refractory Acute Respiratory Distress Syndrome.

BACKGROUND: Acute respiratory distress syndrome (ARDS) is a devastating disorder. Despite enormous efforts in clinical research, effective treatment options are lacking, and mortality rates remain unacceptably high. OBJECTIVES: A male patient with severe ARDS showed no clinical improvement with conventional therapies. Hence, an emergent experimental intervention was performed. METHODS: We performed intratracheal administration of autologous peripheral blood-derived mononuclear cells (PBMCs) and erythropoietin (EPO). RESULTS: We found that after 2 days of initial PBMC/EPO application, lung function improved and extracorporeal membrane oxygenation (ECMO) support was reduced. Bronchoscopy and serum inflammatory markers revealed reduced inflammation. Additionally, serum concentration of miR-449a, b, c and miR-34a, a transient upregulation of E-cadherin and associated chromatin marks in PBMCs indicated airway epithelial differentiation. Extracellular vesicles from PBMCs demonstrated anti-inflammatory capacity in a TNF-α-mediated nuclear factor-x03BA;B in vitro assay. Despite improving respiratory function, the patient died of multisystem organ failure on day 38 of ECMO treatment. CONCLUSIONS: This case report provides initial encouraging evidence to use locally instilled PBMC/EPO for treatment of severe refractory ARDS. The observed clinical improvement may partially be due to the anti-inflammatory effects of PBMC/EPO to promote tissue regeneration. Further studies are needed for more in-depth understanding of the underlying mechanisms of in vivo regeneration.

Like a rolling histone: epigenetic regulation of neural stem cells and brain development by factors controlling histone acetylation and methylation.

BACKGROUND: The development of the nervous system is a highly organized process involving the precise and coordinated timing of many complex events. These events require proper expression of genes promoting survival, differentiation, and maturation, but also repression of alternative cell fates and restriction of cell-type-specific gene expression. SCOPE OF THE REVIEW: As the enzymes mediating post-translational histone acetylation and methylation are regulating higher order chromatin structure and controlling gene transcription, knowledge of the roles for these enzymes becomes crucial for understanding neural development and disease. The widespread expression and general biological roles for chromatin-modifying factors have hampered the studies of such enzymes in neural development, but in recent years, in vivo and in vitro studies have started to shed light on the various processes these enzymes regulate. In this review we summarize the implications of chromatin-modifying enzymes in neural development, with particular emphasis on enzymes regulating histone acetylation and methylation. MAJOR CONCLUSIONS: Enzymes controlling histone acetylation and methylation are involved in the whole process of neural development, from controlling proliferation and undifferentiated, "poised", state of stem cells to promoting and inhibiting neurogenic and gliogenic pathways and neuronal survival as well as neurite outgrowth. GENERAL SIGNIFICANCE: Aberrant enzymatic activities of histone acetyl transferases, deacetylases, and demethylases have been chemically and genetically associated with neural developmental disorders and cancer. Future studies may aim at linking the genetic and developmental studies to more in-depth biochemical characterization to provide a clearer picture of how to improve the diagnosis, prognosis, and treatment of such disorders. This article is part of a Special Issue entitled Biochemistry of Stem Cells.

A probability model for assessing age relative to the 18-year old threshold based on magnetic resonance imaging of the knee combined with radiography of third molars in the lower jaw.

OBJECTIVE: This study aims to generate a statistical model based on magnetic resonance imaging of the knee and radiography of third molars in the lower jaw, for assessing age relative to the 18-year old threshold. METHODS: In total, 58 studies correlating knee or tooth development to age were assessed, 5 studies for knee and 7 studies for tooth were included in the statistical model. The relation between the development of the anatomical site, based on a binary system, and age were estimated using logistic regression. Separate meta-populations for knee and tooth were generated from the individual based data for men and women. A weighted estimate of probabilities was made by combining the probability densities for knee and tooth. Margin of errors for males and females in different age groups and knee and tooth maturity were calculated within the larger framework of transition analysis using a logit model as a base. Evidentiary values for combinations of knee and tooth maturity were evaluated with likelihood ratios. RESULTS: For males, the sensitivity for the method was calculated to 0.78 (probability of correctly classifying adults), the specificity 0.90 (probability of correctly classifying minors), the negative predictive value 0.80 (proportion identified minors are minors) and the positive predictive value 0.89 (proportion identified adults are adults) indicating a model better at identifying minors than adults. The point at which half the female population has reached closed knee lies before the 18-year threshold, adding the knee as an indicator lowers specificity and increases sensitivity. The sensitivity when using tooth as an indicator for females is 0.24 and specificity 0.97, signifying few minors misclassified as adults but also a low probability of identifying adults. The negative predictive value for women when using tooth as the sole indicator is 0.56 and positive predictive value 0.88. Probabilities were calculated for males and females assuming a uniform age distribution between 15 and 21years. The calculated margin of error of minors classified as adults in a population between 15 and 21 years with the model was 11% for males and 12% for females. Further, the evidentiary value as well as margin of error vary for different combinations of knee and tooth maturity. CONCLUSION: The statistical model based on the combination of MRI knee and radiography of mandibular third molars is a valid method to assess age relative to the 18-year old threshold when applied on males and of limited value in females.