Single-nucleus and spatial landscape of the sub-ventricular zone in human glioblastoma.

The sub-ventricular zone (SVZ) is the most well-characterized neurogenic area in the mammalian brain. We previously showed that in 65% of patients with glioblastoma (GBM), the SVZ is a reservoir of cancer stem-like cells that contribute to treatment resistance and emergence of recurrence. Here, we built a single-nucleus RNA-sequencing-based microenvironment landscape of the tumor mass (T_Mass) and the SVZ (T_SVZ) of 15 GBM patients and 2 histologically normal SVZ (N_SVZ) samples as controls. We identified a mesenchymal signature in the T_SVZ of GBM patients: tumor cells from the T_SVZ relied on the ZEB1 regulatory network, whereas tumor cells in the T_Mass relied on the TEAD1 regulatory network. Moreover, the T_SVZ microenvironment was predominantly characterized by tumor-supportive microglia, which spatially co-exist and establish heterotypic interactions with tumor cells. Lastly, differential gene expression analyses, predictions of ligand-receptor and incoming/outgoing interactions, and functional assays revealed that the IL-1ß/IL-1RAcP and Wnt-5a/Frizzled-3 pathways are therapeutic targets in the T_SVZ microenvironment. Our data provide insights into the biology of the SVZ in GBM patients and identify specific targets of this microenvironment.

Soliton Based Dynamic Nuclear Polarization: An Overhauser Effect in Cyclic Polyacetylene at High Field and Room Temperature.

Polyacetylene, a versatile material with an electrical conductivity that can span 7 orders of magnitude, is the prototypical conductive polymer. In this letter, we report the observation of a significant Overhauser effect at the high magnetic field of 14.1 T that operates at 100 K and room temperature in both linear and cyclic polyacetylene. Significant NMR signal enhancements ranging from 24 to 45 are obtained. The increased sensitivity enabled the characterization of the polymer chain defects at natural abundance. The absence of end methyl group carbon-13 signals provides proof of the closed-loop molecular structure of cyclic polyacetylene. The remarkable efficiency of the soliton based Overhauser effect DNP mechanism at high temperature and high field holds promise for applications and extension to other conductive polymer systems.

Combinations of classical and non-classical voltage dependent potassium channel openers suppress nociceptor discharge and reverse chronic pain signs in a rat model of Gulf War illness.

In a companion paper we examined whether combinations of Kv7 channel openers (Retigabine and Diclofenac; RET, DIC) could be effective modifiers of deep tissue nociceptor activity; and whether such combinations could then be optimized for use as safe analgesics for pain-like signs that developed in a rat model of GWI (Gulf War Illness) pain. In the present report, we examined the combinations of Retigabine/Meclofenamate (RET/MEC) and Meclofenamate/Diclofenac (MEC/DIC). Voltage clamp experiments were performed on deep tissue nociceptors isolated from rat DRG (dorsal root ganglion). In voltage clamp studies, a stepped voltage protocol was applied (-55 to -40 mV; Vh=-60 mV; 1500 msec) and Kv7 evoked currents were subsequently isolated by Linopirdine subtraction. MEC greatly enhanced voltage dependent conductance and produced exceptional maximum sustained currents of 6.01 ± 0.26 pA/pF (EC50: 62.2 ± 8.99 µM). Combinations of RET/MEC, and MEC/DIC substantially amplified resting currents at low concentrations. MEC/DIC also greatly improved voltage dependent conductance. In current clamp experiments, a cholinergic challenge test (Oxotremorine-M, 10 µM; OXO), associated with our GWI rat model, produced powerful action potential (AP) bursts (85 APs). Optimized combinations of RET/MEC (5 and 0.5 µM) and MEC/DIC (0.5 and 2.5 µM) significantly reduced AP discharges to 3 and 7 Aps, respectively. Treatment of pain-like ambulatory behavior in our rat model with a RET/MEC combination (5 and 0.5 mg/kg) successfully rescued ambulation deficits, but could not be fully separated from the effect of RET alone. Further development of this approach is recommended.

Enzymatic debridement in critically injured burn patients - Our experience in the intensive care setting and during burn resuscitation.

BACKGROUND: Much of the recent literature on bromelain based enzymatic debridement of burn injury has focused on its use in smaller burn injury and specialist areas such as the hands or genitals (Krieger et al., 2012; Schulz et al., 2017a,b,c,d). This is despite the original papers describing its use in larger burn injury (Rosenberg et al., 2004, 2014). The current EMA license for Nexobrid™ advises that it should not be used for burn injuries of more than 15% TBSA and should be used with caution in patients with pulmonary burn trauma and suspected pulmonary burn trauma. The original safety and efficacy trial of NexoBrid™ limited its use to 15% TBSA aliquots with concern regarding the effect of bromelain on coagulation. In a European consensus paper of experienced burns clinicians, now on its second iteration, 100% of respondents agreed that "up to 30% BSA can be treated by enzymatic debridement based on individual decision" (Hirche et al., 2017). Hofmaenner et al.'s recent study on the safety of enzymatic debridement in extensive burns larger than 15% provides some further evidence that "bromelain based enzymatic debridement can be carried out safely in large-area burns" (Hofmaenner et al., 2020) but the literature is scant in these larger debridement areas. In our centre we have been using enzymatic debridement for resuscitation level burn injury since 2016. We have gained significant learning in this time; this article aims to describe our current protocol for enzymatic debridement in this patient population and highlight specific learning points that might aid other centres in using enzymatic debridement for larger burn injury. METHOD: We performed a search of the IBID database to identify all adult patients who satisfied the inclusion criteria of resuscitation level burn injury (defined as total burn surface area (TBSA) ≥15% in patients aged >16 years), or level 3 admission following burn injury and who underwent Enzymatic Debridement. A case note review was completed, and details comprising patient demographics, TBSA, mechanism of burn, presence of inhalation injury, sequencing of debridement, length of ICU and hospital stay, blood product utilisation and the need for autografting were recorded. No ethical approval has been sought for this retrospective review. RESULTS: We identified 29 patients satisfying the inclusion criteria (Table 1). Between June 2016 and June 2020 the average total burn size of patients who had at least some of their burn treated by enzymatic debridement increased from 21.4% in 2016/17 to 34.7% in 2019/20. In these patients the actual area treated by enzymatic debridement also increased from 11.9% TBSA to 20.3% TBSA. 19 patients (66%) had enzymatic debridement performed within 24 h of injury, a further 2 patients (7%) within 48 h after injury. Patients were more likely to have enzymatic debridement commenced in the first 24 h after injury if they had circumferential limb injury (39% vs 9%) or were planned for enzyme only debridement (78% vs 28%). Those who were planned for combination enzyme and surgical debridement were more likely to have enzymatic debridement commenced after the first 48 h (75%). We have performed enzymatic debridement overnight on one occasion, for a patient who presented with circumferential limb injury and was determined to undergo urgent debridement. CONCLUSION: Much of the literature has described the use of enzymatic debridement in smaller burns, and specialist areas. However, it is our opinion that the advantages of enzymatic debridement appear to be greater in larger burns with a facility for whole burn excision on the day of admission in the ICU cubicle. We have demonstrated significantly reduced blood loss, improved dermal preservation, reduced need for autografting, and a reduction in the number of trips to theatre. We would advocate that both the team and the patient need to be as prepared as they would be for a traditional surgical excision. The early part of our learning curve for enzymatic debridement in resuscitation level injuries was steep, and we were able to build on experience from managing smaller injuries. We recommend any team wishing to using enzymatic debridement gain experience in the same way and develop robust local pathways prior to attempting use in larger burn injuries.

Development of KVO treatment strategies for chronic pain in a rat model of Gulf War Illness.

We examined whether combinations of Kv7 channel openers could be effective modifiers of deep tissue nociceptor activity; and whether such combinations could then be optimized for use as safe analgesics for pain-like signs that developed in a rat model of GWI (Gulf War Illness) pain. Voltage clamp experiments were performed on subclassified nociceptors isolated from rat DRG (dorsal root ganglion). A stepped voltage protocol was applied (-55 to -40 mV; Vh = -60 mV; 1500 ms) and Kv7 evoked currents were subsequently isolated by linopirdine subtraction. Directly activated and voltage activated K+ currents were characterized in the presence and absence of Retigabine (5-100 µM) and/or Diclofenac (50-140 µM). Retigabine produced substantial voltage dependent effects and a maximal sustained current of 1.14 pA/pF ± 0.15 (ED50: 62.7 ± 3.18 µM). Diclofenac produced weak voltage dependent effects but a similar maximum sustained current of 1.01 ± 0.26 pA/pF (ED50: 93.2 ± 8.99 µM). Combinations of Retigabine and Diclofenac substantially amplified resting currents but had little effect on voltage dependence. Using a cholinergic challenge test (Oxotremorine, 10 µM) associated with our GWI rat model, combinations of Retigabine (5 uM) and Diclofenac (2.5, 20 and 50 µM) substantially reduced or totally abrogated action potential discharge to the cholinergic challenge. When combinations of Retigabine and Diclofenac were used to relieve pain-signs in our rat model of GWI, only those combinations associated with serious subacute side effects could relieve pain-like behaviors.

Middle Meningeal Artery Embolization Using Combined Particle Embolization and n-BCA with the Dextrose 5% in Water Push Technique for Chronic Subdural Hematomas: A Prospective Safety and Feasibility Study.

BACKGROUND AND PURPOSE: Embolization of the middle meningeal artery for treatment of refractory or recurrent chronic subdural hematomas has gained momentum during the past few years. Little has been reported on the use of the n-BCA liquid embolic system for middle meningeal artery embolization. We present the technical feasibility of using diluted n-BCA for middle meningeal artery embolization. MATERIALS AND METHODS: We sought to examine the safety and technical feasibility of the diluted n-BCA liquid embolic system for middle meningeal artery embolization. Patients with chronic refractory or recurrent subdural hematomas were prospectively enrolled from September 2019 to June 2020. The primary outcome was the safety and technical feasibility of the use of diluted n-BCA for embolization of the middle meningeal artery. The secondary end point was the efficacy in reducing hematoma volume. RESULTS: A total of 16 patients were prospectively enrolled. Concomitant burr-hole craniotomies were performed in 12 of the 16 patients. Two patients required an operation following middle meningeal artery embolization for persistent symptoms. The primary end point was met in 100% of cases in which there were no intra- or postprocedural complications. Distal penetration of the middle meningeal artery branches was achieved in all the enrolled cases. A 7-day post-middle meningeal artery embolization follow-up head CT demonstrated improvement (>50% reduction in subdural hematoma volume) in 9/15 (60%) patients, with 6/15 (40%) showing an unchanged or stable subdural hematoma. At day 21, available CT scans demonstrated substantial further improvement (>75% reduction in subdural hematoma volume). CONCLUSIONS: Embolization of the middle meningeal artery using diluted n-BCA and ethiodized oil (1:6) is safe and feasible from a technical standpoint. The use of a dextrose 5% bolus improves distal penetration of the glue.

Review of a forensic pseudoscience: Identification of criminals from bitemark patterns.

The forensic sciences are a combination of laboratory procedures and physical comparisons of objects associated with victims, perpetrators, and crime scenes. The former is largely university-based protocols adopted by crime labs. The latter is predominantly pattern-matching tools originally developed by police examiners or experts deemed by courts to be relevant to forensic matters. These Court accepted experts bring their reasoning and conclusions into the legal arena. This subgroup of forensics has undergone significant scrutiny in regards to its history of exaggerated claims and weak scientific foundations. This paper addresses the rise and fall of bitemark pattern analysis (i.e. "matching" bitemarks in human flesh to human teeth) in the environment of opposing interests and agendas.

Parahydrogen-Based Hyperpolarization for Biomedicine.

Magnetic resonance (MR) is one of the most versatile and useful physical effects used for human imaging, chemical analysis, and the elucidation of molecular structures. However, its full potential is rarely used, because only a small fraction of the nuclear spin ensemble is polarized, that is, aligned with the applied static magnetic field. Hyperpolarization methods seek other means to increase the polarization and thus the MR signal. A unique source of pure spin order is the entangled singlet spin state of dihydrogen, parahydrogen (pH2 ), which is inherently stable and long-lived. When brought into contact with another molecule, this "spin order on demand" allows the MR signal to be enhanced by several orders of magnitude. Considerable progress has been made in the past decade in the area of pH2 -based hyperpolarization techniques for biomedical applications. It is the goal of this Review to provide a selective overview of these developments, covering the areas of spin physics, catalysis, instrumentation, preparation of the contrast agents, and applications.

Forensic bitemark identification: weak foundations, exaggerated claims.

Several forensic sciences, especially of the pattern-matching kind, are increasingly seen to lack the scientific foundation needed to justify continuing admission as trial evidence. Indeed, several have been abolished in the recent past. A likely next candidate for elimination is bitemark identification. A number of DNA exonerations have occurred in recent years for individuals convicted based on erroneous bitemark identifications. Intense scientific and legal scrutiny has resulted. An important National Academies review found little scientific support for the field. The Texas Forensic Science Commission recently recommended a moratorium on the admission of bitemark expert testimony. The California Supreme Court has a case before it that could start a national dismantling of forensic odontology. This article describes the (legal) basis for the rise of bitemark identification and the (scientific) basis for its impending fall. The article explains the general logic of forensic identification, the claims of bitemark identification, and reviews relevant empirical research on bitemark identification-highlighting both the lack of research and the lack of support provided by what research does exist. The rise and possible fall of bitemark identification evidence has broader implications-highlighting the weak scientific culture of forensic science and the law's difficulty in evaluating and responding to unreliable and unscientific evidence.

Ghrelin.

BACKGROUND: The gastrointestinal peptide hormone ghrelin was discovered in 1999 as the endogenous ligand of the growth hormone secretagogue receptor. Increasing evidence supports more complicated and nuanced roles for the hormone, which go beyond the regulation of systemic energy metabolism. SCOPE OF REVIEW: In this review, we discuss the diverse biological functions of ghrelin, the regulation of its secretion, and address questions that still remain 15 years after its discovery. MAJOR CONCLUSIONS: In recent years, ghrelin has been found to have a plethora of central and peripheral actions in distinct areas including learning and memory, gut motility and gastric acid secretion, sleep/wake rhythm, reward seeking behavior, taste sensation and glucose metabolism.

Positive dental identification using tooth anatomy and digital superimposition.

Dental identification of unknown human remains continues to be a relevant and reliable adjunct to forensic investigations. The advent of genomic and mitochondrial DNA procedures has not displaced the practical use of dental and related osseous structures remaining after destructive incidents that can render human remains unrecognizable, severely burned, and fragmented. The ability to conclusively identify victims of accident and homicide is based on the availability of antemortem records containing substantial and unambiguous proof of dental and related osseous characteristics. This case report documents the use of digital comparative analysis of antemortem dental models and postmortem dentition, to determine a dental identification. Images of dental models were digitally analyzed using Adobe Photoshop(TM) software. Individual tooth anatomy was compared between the antemortem and postmortem images. Digital superimposition techniques were also used for the comparison. With the absence of antemortem radiographs, this method proved useful to reach a positive identification in this case.

Direct chemical evidence for eumelanin pigment from the Jurassic period.

Melanin is a ubiquitous biological pigment found in bacteria, fungi, plants, and animals. It has a diverse range of ecological and biochemical functions, including display, evasion, photoprotection, detoxification, and metal scavenging. To date, evidence of melanin in fossil organisms has relied entirely on indirect morphological and chemical analyses. Here, we apply direct chemical techniques to categorically demonstrate the preservation of eumelanin in two > 160 Ma Jurassic cephalopod ink sacs and to confirm its chemical similarity to the ink of the modern cephalopod, Sepia officinalis. Identification and characterization of degradation-resistant melanin may provide insights into its diverse roles in ancient organisms.

Magnetophoresis for enhancing transdermal drug delivery: Mechanistic studies and patch design.

Magnetophoresis is a method of enhancement of drug permeation across the biological barriers by application of magnetic field. The present study investigated the mechanistic aspects of magnetophoretic transdermal drug delivery and also assessed the feasibility of designing a magnetophoretic transdermal patch system for the delivery of lidocaine. In vitro drug permeation studies were carried out across the porcine epidermis at different magnetic field strengths. The magnetophoretic drug permeation "flux enhancement factor" was found to increase with the applied magnetic field strength. The mechanistic studies revealed that the magnetic field applied in this study did not modulate permeability of the stratum corneum barrier. The predominant mechanism responsible for magnetically mediated drug permeation enhancement was found to be "magnetokinesis". The octanol/water partition coefficient of drugs was also found to increase when exposed to the magnetic field. A reservoir type transdermal patch system with a magnetic backing was designed for in vivo studies. The dermal bioavailability (AUC(0-6h)) from the magnetophoretic patch system in vivo, in rats was significantly higher than the similarly designed non-magnetic control patch.

Evidence for a cortically mediated release from inhibition in the human cochlea.

PURPOSE: To determine cortical influence on the efferent medial olivocochlear bundle system. RESEARCH DESIGN: The effects of attention on contralateral suppression (CS) of click-evoked otoacoustic emissions were measured. STUDY SAMPLE: Fifteen normal-hearing listeners. RESULTS: CS was greatest in the nonattending condition and decreased significantly when attending to the click or broadband noise suppressor. The effects of attention on CS were not frequency dependent or due to changes in recording noise measures. CONCLUSIONS: Attention to either the ipsilateral, evoking stimulus or the contralateral suppressor causes a top-down, cortically mediated release from inhibition at the level of the cochlea that is measurable with common audiologic protocols and instrumentation. Future studies assessing the effects of attention on CS of click-evoked otoacoustic emissions in normal controls and individuals with various auditory or attentional deficits may provide valuable information about the capabilities of the cortex to affect peripheral processing in a normal and/or pathological system.

Expert disagreement in bitemark casework.

Bitemark cases continue to raise controversy due to the degree of expert disagreement which is frequently seen. Using a case mix of 49 bitemark cases from 2000 to 2007 each injury was independently assessed for its forensic significance using a previously described bitemark severity scale. Following the assessment, the mean value for the bites was categorized according to the crime type, the degree of expert agreement, and the judicial outcome. Results suggest that bitemarks found in child abuse cases have statistically significantly lower forensic value than those in other crime types, that bites where there is mutual agreement between experts will have higher forensic value than those where there is disagreement at trial, and that cases in which DNA has provided an exoneration will demonstrate similar quality to those where a conviction was secured. Forensic odontologists should carefully assess bitemark evidence and ensure that it meets certain minimums in relation to the presence of class and unique features before undertaking an analysis.

Transforming electrocortical mapping data into standardized common space.

Subdural grid electrodes are implanted routinely for the pre-surgical work up of epilepsy. While different approaches are available, many centers, including ours, visualize electrode locations by co-registering pre-operative 3-D MR images with post-implantation 3-D CT images. This method allows the determination of the electrode positions in relation to the individual patient's anatomy, but does not easily allow comparison across patients. The goal of this study was to develop and validate a method for transforming electrode positions derived from 3-D CT images into standardized space. We analyzed data from twelve patients with subdurally implanted electrodes. Volumetric CT and MRI images were co-registered and then normalized into common stereotactic space. Electrode locations were verified statistically by comparing distances between the anterior commissure and a representative sampling of 8 electrode sites per patient. Results confirm the accuracy of our co-registration method for comparing electrode locations across patients.

Problem-based analysis of bitemark misidentifications: the role of DNA.

The dental literature concerning bitemark methodology is surprisingly thin and sorely lacking in rigorous scientific testing. Contra to this fact, the bitemark legal caselaw is surprisingly strong and is used as a substitute for reliability testing of bite mark identification. In short, the Judiciary and the Prosecutors have loved forensic odontologists. This paper will focus on the author's participation as a Defense expert over the last seven years in over 50 bitemark prosecutions and judicial appeals. This sampling will act as an anecdotal survey of actual bitemark evidence. Certain trends regarding methods and reliability issues of odontologists will be discussed. Several of these cases have been later judicially overturned due to DNA analyses after the defendants were originally convicted. These diagnostic misadventures are being vocally discussed in the US media by news and legal investigators who are asking hard questions. The forensic dentistry community, however, is curiously silent. What actions are necessary by the profession to improve this assault on the 52-year tradition of bite mark identifications in the United States?