Effect of pre-intercalation on Li-ion diffusion mapped by topochemical single-crystal transformation and operando investigation.

Limitations in electrochemical performance as well as supply chain challenges have rendered positive electrode materials a critical bottleneck for Li-ion batteries. State-of-the-art Li-ion batteries fall short of accessing theoretical capacities. As such, there is intense interest in the design of strategies that enable the more effective utilization of active intercalation materials. Pre-intercalation with alkali-metal ions has attracted interest as a means of accessing higher reversible capacity and improved rate performance. However, the structural basis for improvements in electrochemical performance remains mostly unexplored. Here we use topochemical single-crystal-to-single-crystal transformations in a tunnel-structured ζ-V2O5 positive electrode to illustrate the effect of pre-intercalation in modifying the host lattice and altering diffusion pathways. Furthermore, operando synchrotron X-ray diffraction is used to map Li-ion site preferences and occupancies as a function of the depth of discharge in pre-intercalated materials. Na- and K-ion intercalation 'props open' the one-dimensional tunnel, reduces electrostatic repulsions between inserted Li ions and entirely modifies diffusion pathways, enabling orders of magnitude higher Li-ion diffusivities and accessing higher capacities. Deciphering the atomistic origins of improved performance in pre-intercalated materials on the basis of single-crystal-to-single-crystal topochemical transformation and operando diffraction studies paves the way to site-selective modification approaches for positive electrode design.

Cation reordering instead of phase transitions: Origins and implications of contrasting lithiation mechanisms in 1D ζ- and 2D α-V2O5.

Substantial improvements in cycle life, rate performance, accessible voltage, and reversible capacity are required to realize the promise of Li-ion batteries in full measure. Here, we have examined insertion electrodes of the same composition (V2O5) prepared according to the same electrode specifications and comprising particles with similar dimensions and geometries that differ only in terms of their atomic connectivity and crystal structure, specifically two-dimensional (2D) layered α-V2O5 that crystallizes in an orthorhombic space group and one-dimensional (1D) tunnel-structured ζ-V2O5 crystallized in a monoclinic space group. By using particles of similar dimensions, we have disentangled the role of specific structural motifs and atomistic diffusion pathways in affecting electrochemical performance by mapping the dynamical evolution of lithiation-induced structural modifications using ex situ scanning transmission X-ray microscopy, operando synchrotron X-ray diffraction measurements, and phase-field modeling. We find the operation of sharply divergent mechanisms to accommodate increasing concentrations of Li-ions: a series of distortive phase transformations that result in puckering and expansion of interlayer spacing in layered α-V2O5, as compared with cation reordering along interstitial sites in tunnel-structured ζ-V2O5 By alleviating distortive phase transformations, the ζ-V2O5 cathode shows reduced voltage hysteresis, increased Li-ion diffusivity, alleviation of stress gradients, and improved capacity retention. The findings demonstrate that alternative lithiation mechanisms can be accessed in metastable compounds by dint of their reconfigured atomic connectivity and can unlock substantially improved electrochemical performance not accessible in the thermodynamically stable phase.

Preclinical characterization of a non-peptidomimetic HIV protease inhibitor with improved metabolic stability.

Protease inhibitors (PIs) remain an important component of antiretroviral therapy for the treatment of HIV-1 infection due to their high genetic barrier to resistance development. Nevertheless, the two most commonly prescribed HIV PIs, atazanavir and darunavir, still require co-administration with a pharmacokinetic boosting agent to maintain sufficient drug plasma levels which can lead to undesirable drug-drug interactions. Herein, we describe GS-9770, a novel investigational non-peptidomimetic HIV PI with unboosted once-daily oral dosing potential due to improvements in its metabolic stability and its pharmacokinetic properties in preclinical animal species. This compound demonstrates potent inhibitory activity and high on-target selectivity for recombinant HIV-1 protease versus other aspartic proteases tested. In cell culture, GS-9770 inhibits Gag polyprotein cleavage and shows nanomolar anti-HIV-1 potency in primary human cells permissive to HIV-1 infection and against a broad range of HIV subtypes. GS-9770 demonstrates an improved resistance profile against a panel of patient-derived HIV-1 isolates with resistance to atazanavir and darunavir. In resistance selection experiments, GS-9770 prevented the emergence of breakthrough HIV-1 variants at all fixed drug concentrations tested and required multiple protease substitutions to enable outgrowth of virus exposed to escalating concentrations of GS-9770. This compound also remained fully active against viruses resistant to drugs from other antiviral classes and showed no in vitro antagonism when combined pairwise with drugs from other antiretroviral classes. Collectively, these preclinical data identify GS-9770 as a potent, non-peptidomimetic once-daily oral HIV PI with potential to overcome the persistent requirement for pharmacological boosting with this class of antiretroviral agents.

Off-Target In Vitro Profiling Demonstrates that Remdesivir Is a Highly Selective Antiviral Agent.

Remdesivir (RDV, GS-5734), the first FDA-approved antiviral for the treatment of COVID-19, is a single diastereomer monophosphoramidate prodrug of an adenosine analogue. It is intracellularly metabolized into the active triphosphate form, which in turn acts as a potent and selective inhibitor of multiple viral RNA polymerases. RDV has broad-spectrum activity against members of the coronavirus family, such as SARS-CoV-2, SARS-CoV, and MERS-CoV, as well as filoviruses and paramyxoviruses. To assess the potential for off-target toxicity, RDV was evaluated in a set of cellular and biochemical assays. Cytotoxicity was evaluated in a set of relevant human cell lines and primary cells. In addition, RDV was evaluated for mitochondrial toxicity under aerobic and anaerobic metabolic conditions, and for the effects on mitochondrial DNA content, mitochondrial protein synthesis, cellular respiration, and induction of reactive oxygen species. Last, the active 5'-triphosphate metabolite of RDV, GS-443902, was evaluated for potential interaction with human DNA and RNA polymerases. Among all of the human cells tested under 5 to 14 days of continuous exposure, the 50% cytotoxic concentration (CC50) values of RDV ranged from 1.7 to >20 µM, resulting in selectivity indices (SI, CC50/EC50) from >170 to 20,000, with respect to RDV anti-SARS-CoV-2 activity (50% effective concentration [EC50] of 9.9 nM in human airway epithelial cells). Overall, the cellular and biochemical assays demonstrated a low potential for RDV to elicit off-target toxicity, including mitochondria-specific toxicity, consistent with the reported clinical safety profile.

Key Metabolic Enzymes Involved in Remdesivir Activation in Human Lung Cells.

Remdesivir (RDV; GS-5734, Veklury), the first FDA-approved antiviral to treat COVID-19, is a single-diastereomer monophosphoramidate prodrug of an adenosine analogue. RDV is taken up in the target cells and metabolized in multiple steps to form the active nucleoside triphosphate (TP) (GS-443902), which, in turn, acts as a potent and selective inhibitor of multiple viral RNA polymerases. In this report, we profiled the key enzymes involved in the RDV metabolic pathway with multiple parallel approaches: (i) bioinformatic analysis of nucleoside/nucleotide metabolic enzyme mRNA expression using public human tissue and lung single-cell bulk mRNA sequence (RNA-seq) data sets, (ii) protein and mRNA quantification of enzymes in human lung tissue and primary lung cells, (iii) biochemical studies on the catalytic rate of key enzymes, (iv) effects of specific enzyme inhibitors on the GS-443902 formation, and (v) the effects of these inhibitors on RDV antiviral activity against SARS-CoV-2 in cell culture. Our data collectively demonstrated that carboxylesterase 1 (CES1) and cathepsin A (CatA) are enzymes involved in hydrolyzing RDV to its alanine intermediate MetX, which is further hydrolyzed to the monophosphate form by histidine triad nucleotide-binding protein 1 (HINT1). The monophosphate is then consecutively phosphorylated to diphosphate and triphosphate by cellular phosphotransferases. Our data support the hypothesis that the unique properties of RDV prodrug not only allow lung-specific accumulation critical for the treatment of respiratory viral infection such as COVID-19 but also enable efficient intracellular metabolism of RDV and its MetX to monophosphate and successive phosphorylation to form the active TP in disease-relevant cells.

Discovery of the pan-genotypic hepatitis C virus NS3/4A protease inhibitor voxilaprevir (GS-9857): A component of Vosevi®.

Treatment of hepatitis C virus (HCV) infection has been historically challenging due the high viral genetic complexity wherein there are eight distinct genotypes and at least 86 viral subtypes. While HCV NS3/4A protease inhibitors are an established treatment option for genotype 1 infection, limited coverage of genotypes 2 and/or 3 combined with serum alanine transaminase (ALT) elevations for some compounds has limited the broad utility of this therapeutic class. Our discovery efforts were focused on identifying an NS3/4A protease inhibitor with pan-genotypic antiviral activity, improved coverage of resistance associated substitutions, and a decreased risk of hepatotoxicity. Towards this goal, distinct interactions with the conserved catalytic triad of the NS3/4A protease were identified that improved genotype 3 antiviral activity. We further discovered that protein adduct formation strongly correlated with clinical ALT elevation for this therapeutic class. Improving metabolic stability and decreasing protein adduct formation through structural modifications ultimately resulted in voxilaprevir. Voxilaprevir, in combination with sofosbuvir and velpatasvir, has demonstrated pan-genotypic antiviral clinical activity. Furthermore, hepatotoxicity was not observed in Phase 3 clinical trials with voxilaprevir, consistent with our design strategy. Vosevi® (sofosbuvir, velpatasvir, and voxilaprevir) is now an approved pan-genotypic treatment option for the most difficult-to-cure individuals who have previously failed direct acting antiviral therapy.

Biochemical characterization and structure determination of a potent, selective antibody inhibitor of human MMP9.

Matrix metalloproteinase 9 (MMP9) is a member of a large family of proteases that are secreted as inactive zymogens. It is a key regulator of the extracellular matrix, involved in the degradation of various extracellular matrix proteins. MMP9 plays a pathological role in a variety of inflammatory and oncology disorders and has long been considered an attractive therapeutic target. GS-5745, a potent, highly selective humanized monoclonal antibody inhibitor of MMP9, has shown promise in treating ulcerative colitis and gastric cancer. Here we describe the crystal structure of GS-5745·MMP9 complex and biochemical studies to elucidate the mechanism of inhibition of MMP9 by GS-5745. GS-5745 binds MMP9 distal to the active site, near the junction between the prodomain and catalytic domain, and inhibits MMP9 by two mechanisms. Binding to pro-MMP9 prevents MMP9 activation, whereas binding to active MMP9 allosterically inhibits activity.

Characteristics of Patients With Constant Observers.

BACKGROUND: The use of constant observers ("sitters") has been common practice in many medical centers to maintain patient safety. RESULTS: A retrospective chart review of patients who required sitters from October 1, 2007 to September 31, 2013 at a large, private hospital serving a multiethnic community showed that the top reasons for sitters include suicide risk, agitation, fall risk, interfering with medical devices, and confusion/disorientation. Sitters were used for a mean of 3.4 days ranging from 1 to 287 days, with a mean hospital length of stay of 18.9 days. Although 42.4% of all cases with sitters had a psychiatric consultation, psychiatry was consulted on only 8.5% of those with agitation, 6.3% of those who were disoriented, and 12.7% of those with decisional capacity concerns. Psychiatry was consulted on 87.4% of patients with a constant observer for suicide risks. Sitters were most often discontinued when behaviors improved or when patients were discharged. CONCLUSION: This information will be useful for understanding the optimal way to implement a program that will increase patient safety and decrease cost.

Clinician Attitudes Toward Adoption of Pediatric Emergency Telemedicine in Rural Hospitals.

OBJECTIVE: Although there is growing evidence regarding the utility of telemedicine in providing care for acutely ill children in underserved settings, adoption of pediatric emergency telemedicine remains limited, and little data exist to inform implementation efforts. Among clinician stakeholders, we examined attitudes regarding pediatric emergency telemedicine, including barriers to adoption in rural settings and potential strategies to overcome these barriers. METHODS: Using a sequential mixed-methods approach, we first performed semistructured interviews with clinician stakeholders using thematic content analysis to generate a conceptual model for pediatric emergency telemedicine adoption. Based on this model, we then developed and fielded a survey to further examine attitudes regarding barriers to adoption and strategies to improve adoption. RESULTS: Factors influencing adoption of pediatric emergency telemedicine were identified and categorized into 3 domains: contextual factors (such as regional geography, hospital culture, and individual experience), perceived usefulness of pediatric emergency telemedicine, and perceived ease of use of pediatric emergency telemedicine. Within the domains of perceived usefulness and perceived ease of use, belief in the relative advantage of telemedicine was the most pronounced difference between telemedicine proponents and nonproponents. Strategies identified to improve adoption of telemedicine included patient-specific education, clinical protocols for use, decreasing response times, and simplifying the technology. CONCLUSIONS: More effective adoption of pediatric emergency telemedicine among clinicians will require addressing perceived usefulness and perceived ease of use in the context of local factors. Future studies should examine the impact of specific identified strategies on adoption of pediatric emergency telemedicine and patient outcomes in rural settings.

Simultaneous usage of dementia medications and anticholinergics among Asians and Pacific Islanders.

BACKGROUND: The simultaneous use of dementia medications and anticholinergic medications occurs frequently. Cholinesterase inhibitors and anticholinergic medications likely counteract one another, potentially exposing patients to medications with decreased benefit, more adverse effects, and higher cost of care. We identified the rate of concurrent prescriptions of cholinesterase inhibitors/memantine with anticholinergics in an urban hospital setting with a large Asian and Pacific Islander population. METHODS: This study is a retrospective review of patients hospitalized from 1 January 2006 to 31 December 2010 at a general hospital who simultaneously received US Food and Drug Administration-approved dementia medications (galantamine, rivastigmine, donepezil, and/or memantine) and anticholinergics. RESULTS: Overall, 304 patients receiving cholinesterase inhibitors/memantine also received anticholinergics. Of these patients, 64.1% were given high-potency anticholinergic medications, and 35.9% received medium-potency medications. Indications for the use of anticholinergic medication were urological (17.8%), gastrointestinal excluding nausea (32.6%), nausea (10.2%), psychiatric (7.9%), and other (31.6%). Asian patients received the combination of cholinesterase inhibitors/memantine and anticholinergics less frequently than Native Hawaiian or Caucasian patients (8.4% vs 12.2% and 13.3%, respectively; χ2 = 16.04, degrees of freedom = 2, P < 0.0003). CONCLUSIONS: Simultaneous prescribing of cholinesterase inhibitors, memantine, and anticholinergic medications was significantly less common than in previous studies, with some ethnic variability. The less frequent occurrence of concurrent medications in the Asian population may be because of variations in the rate of indications or in tolerability for anticholinergic medications among the population.

Structural, biochemical, and biophysical characterization of idelalisib binding to phosphoinositide 3-kinase δ.

Idelalisib (also known as GS-1101, CAL-101, IC489666, and Zydelig) is a PI3Kδ inhibitor that has recently been approved for the treatment of several hematological malignancies. Given its use in human diseases, we needed a clear picture of how idelalisib binds to and inhibits PI3Kδ. Our data show that idelalisib is a potent and selective inhibitor of the kinase activity of PI3Kδ. A kinetic characterization clearly demonstrated ATP-competitive inhibition, and several additional biochemical and biophysical assays showed that the compound binds reversibly and noncovalently to the kinase. A crystal structure of idelalisib bound to the p110δ subunit of PI3Kδ furthers our understanding of the binding interactions that confer the potency and selectivity of idelalisib.

Role of Mitochondrial RNA Polymerase in the Toxicity of Nucleotide Inhibitors of Hepatitis C Virus.

Toxicity has emerged during the clinical development of many but not all nucleotide inhibitors (NI) of hepatitis C virus (HCV). To better understand the mechanism for adverse events, clinically relevant HCV NI were characterized in biochemical and cellular assays, including assays of decreased viability in multiple cell lines and primary cells, interaction with human DNA and RNA polymerases, and inhibition of mitochondrial protein synthesis and respiration. NI that were incorporated by the mitochondrial RNA polymerase (PolRMT) inhibited mitochondrial protein synthesis and showed a corresponding decrease in mitochondrial oxygen consumption in cells. The nucleoside released by the prodrug balapiravir (R1626), 4'-azido cytidine, was a highly selective inhibitor of mitochondrial RNA transcription. The nucleotide prodrug of 2'-C-methyl guanosine, BMS-986094, showed a primary effect on mitochondrial function at submicromolar concentrations, followed by general cytotoxicity. In contrast, NI containing multiple ribose modifications, including the active forms of mericitabine and sofosbuvir, were poor substrates for PolRMT and did not show mitochondrial toxicity in cells. In general, these studies identified the prostate cell line PC-3 as more than an order of magnitude more sensitive to mitochondrial toxicity than the commonly used HepG2 cells. In conclusion, analogous to the role of mitochondrial DNA polymerase gamma in toxicity caused by some 2'-deoxynucleotide analogs, there is an association between HCV NI that interact with PolRMT and the observation of adverse events. More broadly applied, the sensitive methods for detecting mitochondrial toxicity described here may help in the identification of mitochondrial toxicity prior to clinical testing.

Binding kinetics, potency, and selectivity of the hepatitis C virus NS3 protease inhibitors GS-9256 and vedroprevir.

BACKGROUND: GS-9256 and vedroprevir are inhibitors of the hepatitis C virus NS3 protease enzyme, an important drug target. The potency, selectivity, and binding kinetics of the two compounds were determined using in vitro biochemical assays. METHODS: Potency of the compounds against NS3 protease and selectivity against a panel of mammalian proteases were determined through steady-state enzyme kinetics. Binding kinetics were determined using stopped-flow techniques. Dissociation rates were measured using dilution methods. RESULTS: GS-9256 and vedroprevir had measured Ki values of 89 pM and 410 pM, respectively, against genotype 1b NS3 protease; Ki values were higher against genotype 2a (2.8 nM and 39 nM) and genotype 3 proteases (104 nM and 319 nM) for GS-9256 and vedroprevir, respectively. Selectivity of GS-9256 and vedroprevir was >10,000-fold against all tested off-target proteases. Association rate constants of 4×10(5)M(-1)s(-1) and 1×10(6)M(-1)s(-1), respectively, were measured, and dissociation rate constants of 4.8×10(-5)s(-1) and 2.6×10(-4)s(-1) were determined. CONCLUSIONS: GS-9256 and vedroprevir are potent inhibitors of NS3 protease with high selectivity against off-target proteases. They have rapid association kinetics and slow dissociation kinetics. GENERAL SIGNIFICANCE: The NS3 protease is a key drug target for the treatment of hepatitis C. The potency, selectivity, and binding kinetics of GS-9256 and vedroprevir constitute a biochemical profile that supports the evaluation of these compounds in combination with other direct-acting antivirals in clinical trials for hepatitis C.

Characterizing analgesic use during air medical transport of injured children.

BACKGROUND: Pain management is an important aspect of emergency care for children suffering traumatic injuries. OBJECTIVES: The objectives of this study were to characterize analgesic administration to injured children during air medical transport, to describe factors associated with analgesic use, and to examine the effects of patient race on analgesia. METHODS: We used electronic records for patients transported by a regional air medical transport agency. We retrospectively examined data from 2003-2012 for patients ≤ 15 years old suffering traumatic injuries. We used bivariable analyses to identify associations for multivariable logistic regression models to determine factors associated with our outcomes -documentation of pain score and analgesic administration. RESULTS: Of 5,057 patients, the median age was 8 (IQR 3-12) years. The majority of patients were male (66%, 95% CI 64-66%), were white non-Hispanic (83%, 95% CI 82-84%), and had no pain score documented (61%, 95% CI 60-62%). While only 15% of patients received analgesics overall, 70% with an initial pain score ≥ 5 received analgesics. In unadjusted models, non-white race was associated with lower odds of having a pain score documented (OR 0.52, 95% CI 0.44-0.62) and receiving analgesics (OR 0.64, 95% CI 0.50-0.82). After adjusting for confounders, there was no evidence of racial differences in pain management. Multivariable analysis revealed that younger age, lack of intravenous access, higher Glasgow Coma Scale, systolic blood pressure <100, transportation from the scene, initial pain score <5, and not having a pain score documented were associated with lower odds of receiving analgesics. CONCLUSIONS: Few pediatric patients had pain scores documented and fewer received analgesics during air medical transport for injuries. Racial differences in analgesia seen in unadjusted analyses did not persist after controlling for confounders. Resources, training, and appropriate pain management protocols should be made available to facilitate pain assessment in children as a strategy for increasing appropriate analgesic use during transport.

Surface-mediated tunable self-assembly of single crystal semimetallic ErSb/GaSb nanocomposite structures.

Arrays of metallic nanostructures embedded within a semiconducting matrix are of great interest for applications in plasmonics, photonic crystals, thermoelectrics, and nanoscale ohmic contacts. We report a method for growing single crystal arrays of semimetallic vertical and horizontal ErSb nanorods, nanotrees, and nanosheets embedded within a semiconducting GaSb matrix. The nanostructures form simultaneously with the matrix and have epitaxial, coherent interfaces with no evidence of stacking faults or dislocations as observed by high-resolution transmission electron microscopy. By combining molecular beam epitaxy growth and in situ scanning tunneling microscopy, we image the growth surface one atomic layer at a time and show that the nanostructured composites form via a surface-mediated self-assembly mechanism that is controlled entirely at the growth front and is not a product of bulk diffusion or bulk segregation. These highly tunable nanocomposites show promise for direct integration into epitaxial semiconductor device structures and also provide a unique system in which to study the atomic scale mechanisms for nucleation and growth.

Utility of electroencephalography in toxin-induced seizures.

INTRODUCTION: Toxin-induced seizures differ from seizures occurring in epilepsy and have a high rate of complications. Electroencephalography (EEG) is routinely obtained when there is concern for nonconvulsive status epilepticus (NCSE). The purpose of this study was to characterize the typical findings after toxin-induced seizures, assess the rate of epileptiform discharges and NCSE, and identify any changes in management resulting from EEG. METHODS: Patients older than 16 years who had an EEG during hospitalization for drug-induced seizure or seizure-like activity were included. We reviewed 10 years of data (2013-2022) across our hospital system (four community hospitals and one academic center). Patients with a history of seizures and those with cardiac arrest prior to EEG were excluded. The primary outcome was incidence of epileptiform discharges on EEG. The secondary outcome was number of antiseizure medications (ASM) added after EEG. RESULTS: A total of 256 encounters were screened with 83 patient encounters included. A total of 53% (44/83) of EEGs showed some degree of generalized slowing. A total of 2.4% (2/83) of cases had epileptiform activity on EEG. No cases of nonconvulsive status were identified. No ASM was started in the two cases where epileptiform discharges were identified. CONCLUSIONS: During usual care of toxin-induced seizures, epileptiform discharges are uncommon.

Interactions of aqueous Ag+ with fulvic acids: mechanisms of silver nanoparticle formation and investigation of stability.

This study investigated the possible natural formation of silver nanoparticles (AgNPs) in Ag(+)-fulvic acid (FA) solutions under various environmentally relevant conditions (temperature, pH, and UV light). Increase in temperature (24-90 °C) and pH (6.1-9.0) of Ag(+)-Suwannee River fulvic acid (SRFA) solutions accelerated the appearance of the characteristic surface plasmon resonance (SPR) of AgNPs. The rate of AgNP formation via reduction of Ag(+) in the presence of different FAs (SRFA, Pahokee Peat fulvic acid, PPFA, Nordic lake fulvic acid, NLFA) and Suwannee River humic acid (SRHA) followed the order NLFA > SRHA > PPFA > SRFA. This order was found to be related to the free radical content of the acids, which was consistent with the proposed mechanism. The same order of AgNP growth was seen upon UV light illumination of Ag(+)-FA and Ag(+)-HA mixtures in moderately hard reconstituted water (MHRW). Stability studies of AgNPs, formed from the interactions of Ag(+)-SRFA, over a period of several months showed that these AgNPs were highly stable with SPR peak reductions of only ~15%. Transmission electron microscopy (TEM) and dynamic light scattering (DLS) measurements revealed bimodal particle size distributions of aged AgNPs. The stable AgNPs formed through the reduction of Ag(+) by fulvic and humic acid fractions of natural organic matter in the environment may be transported over significant distances and might also influence the overall bioavailability and ecotoxicity of AgNPs.

Diagnostic accuracy of a single point-of-care prehospital serum lactate for predicting outcomes in pediatric trauma patients.

BACKGROUND: Preliminary evidence suggests that a single prehospital lactate level (pLA) improves prediction of morbidity and mortality in adult trauma patients independent of vital signs. However, the value of pLA for pediatric trauma patients is unknown. Our objective was to determine whether pLA is associated with the need for critical care in pediatric trauma patients. METHODS: We conducted a cohort study of 217 patients transported by helicopter to a level I pediatric trauma center over 24 months. The primary outcome was the need for predefined critical care measures. Covariates included vital signs and Glasgow Coma Scale (GCS) scores documented by prehospital providers. RESULTS: Forty-one subjects required critical care. Abnormal prehospital vital signs were not associated with need for critical care. Overall, median pLA level for patients who required critical care was 2.1 mmol/L (interquartile range [IQR], 1.6-2.7 mmol/L) versus 1.7 mmol/L (IQR, 1.2-2.2 mmol/L) for those who did not (P = 0.01). In addition, there were 85 subjects who had normal vital signs and a normal GCS during transport. Of these, 11 (13%) required critical care. In the subset of patients with normal prehospital vital signs and GCS, median pLA level for patients who required critical care was 2.6 mmol/L (IQR, 1.8-2.6 mmol/L) versus 1.7 mmol/L (IQR, 1-2.1 mmol/L) for those who did not (P = 0.01). CONCLUSIONS: Prehospital lactate level was higher in pediatric trauma patients who required critical care, including those who had normal prehospital vital signs and GCS. In this cohort, lactate was an early identifier of children with severe traumatic injuries.

Effective Decontamination and Remediation After Elemental Mercury Exposure: A Case Report in the United States.

Elemental mercury exposure can result in significant toxicity. Source decontamination and remediation are often required after larger elemental mercury exposures, but the details of these processes are infrequently reported. In the case described herein, a 64-year-old woman and her husband were exposed to elemental mercury in their home after the husband purchased it online for the purpose of recreational barometer calibration. After the mercury reportedly spilled during the calibration process, a vacuum cleaner was used to decontaminate the affected surface; this led to extensive mercury contamination of the home. The couple was relocated from the home while remediation occurred over the course of several weeks. Vacuum cleaning of an elemental mercury spill can lead to extensive volatilization and recirculation of mercury vapor. For smaller mercury spills, careful removal of visible mercury beads by using an eyedropper, cardboard, and masking tape is recommended. Larger spills require professional decontamination and remediation and may necessitate involvement of governmental resources. Vacuum cleaning should not be used as an initial method of decontamination after elemental mercury exposure. Careful attention to source decontamination can reduce the emotional and financial costs associated with extensive remediation after elemental mercury exposure.

Evaluation of vascular delivery methodologies to enhance rAAV6-mediated gene transfer to canine striated musculature.

A growing body of research supports the development of recombinant adeno-associated viral (rAAV) vectors for delivery of gene expression cassettes to striated musculature as a method of treating severe neuromuscular conditions. However, it is unclear whether delivery protocols that achieve extensive gene transfer in mice can be adapted to produce similarly extensive gene transfer in larger mammals and ultimately patients. Consequently, we sought to investigate methodological modifications that would facilitate rAAV-mediated gene transfer to the striated musculature of canines. A simple procedure incorporating acute (i) occlusion of limb blood flow, (ii) exsanguination via compression bandage, and (iii) vector "dwell" time of <20 minutes, markedly enhanced the transduction of limb muscles, compared with a simple bolus limb infusion of vector. A complementary method whereby vector was infused into the jugular vein led to efficient transduction of cardiomyocytes and to a lesser degree the diaphragm. Together these methods can be used to achieve transgene expression in heart, diaphragm, and limb muscles of juvenile dogs using rAAV6 vectors. These results establish that rAAV-mediated gene delivery is a viable approach to achieving systemic transduction of striated musculature in mammals approaching the dimensions of newborn humans.