State-Dependent Inhibition of Nav1.8 Sodium Channels by VX-150 and VX-548.

Nav1.8 sodium channels (Nav1.8) are an attractive therapeutic target for pain because they are prominent in primary pain-sensing neurons with little expression in most other kinds of neurons.

Mechanisms of pacemaking in mammalian neurons.

Many neurons in the mammalian brain show pacemaking activity: rhythmic generation of action potentials in the absence of sensory or synaptic input. Slow pacemaking of neurons releasing modulatory transmitters is easy to rationalize. More surprisingly, many neurons in the motor system also show pacemaking activity, often rapid, including cerebellar Purkinje neurons that fire spontaneously at 20-100 Hz, as well as key neurons in the basal ganglia, including subthalamic nucleus neurons and globus pallidus neurons.

Downregulation of the silent potassium channel Kv8.1 increases motor neuron vulnerability in amyotrophic lateral sclerosis.

While voltage-gated potassium channels have critical roles in controlling neuronal excitability, they also have non-ion-conducting functions. Kv8.1, encoded by the KCNV1 gene, is a 'silent' ion channel subunit whose biological role is complex since Kv8.

Cannabidiol inhibits Na channels through two distinct binding sites.

Cannabidiol (CBD), a major non-psychoactive phytocannabinoid in cannabis, is an effective treatment for some forms of epilepsy and pain. At high concentrations, CBD interacts with a huge variety of proteins, but which targets are most relevant for clinical actions is still unclear. Here we show that CBD interacts with Na1.

Scalable generation of sensory neurons from human pluripotent stem cells.

Development of new non-addictive analgesics requires advanced strategies to differentiate human pluripotent stem cells (hPSCs) into relevant cell types. Following principles of developmental biology and translational applicability, here we developed an efficient stepwise differentiation method for peptidergic and non-peptidergic nociceptors. By modulating specific cell signaling pathways, hPSCs were first converted into SOX10 neural crest, followed by differentiation into sensory neurons.

Use-Dependent Relief of Inhibition of Nav1.8 Channels by A-887826.

Sodium channel inhibitors used as local anesthetics, antiarrhythmics, or antiepileptics typically have the property of use-dependent inhibition, whereby inhibition is enhanced by repetitive channel activation. For targeting pain, Nav1.8 channels are an attractive target because they are prominent in primary pain-sensing neurons, with little or no expression in most other kinds of neurons, and a number of Nav1.

Relations among gratitude, adaptation to disability, and flourishing among adults with disabilities: A longitudinal mediation model.

Purpose/objective: Flourishing, a primary outcome of rehabilitation psychology, is understudied among adults with disabilities. Gratitude has emerged as an individual strength that is both malleable and robust in predicting flourishing and adaptation to disability. The purpose of this study was to assess the influence of gratitude on flourishing over time and to analyze the potential mediating role of adaptation to disability on this relationship for a group of adults with disabilities.

The MyLO CRISPR-Cas9 toolkit: a markerless yeast localization and overexpression CRISPR-Cas9 toolkit.

The genetic tractability of the yeast Saccharomyces cerevisiae has made it a key model organism for basic research and a target for metabolic engineering. To streamline the introduction of tagged genes and compartmental markers with powerful Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR) - CRISPR-associated protein 9 (Cas9)-based genome editing tools, we constructed a Markerless Yeast Localization and Overexpression (MyLO) CRISPR-Cas9 toolkit with 3 components: (1) a set of optimized Streptococcus pyogenes Cas9-guide RNA expression vectors with 5 selectable markers and the option to either preclone or cotransform the gRNAs; (2) vectors for the one-step construction of integration cassettes expressing an untagged or green fluorescent protein/red fluorescent protein/hemagglutinin-tagged gene of interest at one of 3 levels, supporting localization and overexpression studies; and (3) integration cassettes containing moderately expressed green fluorescent protein- or red fluorescent protein-tagged compartmental markers for colocalization experiments. These components allow rapid, high-efficiency genomic integrations and modifications with only transient selection for the Cas9 vector, resulting in markerless transformations.

Functional expression of opioid receptors and other human GPCRs in yeast engineered to produce human sterols.

The yeast Saccharomyces cerevisiae is powerful for studying human G protein-coupled receptors as they can be coupled to its mating pathway. However, some receptors, including the mu opioid receptor, are non-functional, which may be due to the presence of the fungal sterol ergosterol instead of cholesterol. Here we engineer yeast to produce cholesterol and introduce diverse mu, delta, and kappa opioid receptors to create sensitive opioid biosensors that recapitulate agonist binding profiles and antagonist inhibition.

Cannabidiol activates neuronal Kv7 channels.

Cannabidiol (CBD), a chemical found in the plant, is a clinically effective antiepileptic drug whose mechanism of action is unknown. Using a fluorescence-based thallium flux assay, we performed a large-scale screen and found enhancement of flux through heterologously expressed human Kv7.2/7.

Anthrax toxins regulate pain signaling and can deliver molecular cargoes into ANTXR2 DRG sensory neurons.

Bacterial products can act on neurons to alter signaling and function. In the present study, we found that dorsal root ganglion (DRG) sensory neurons are enriched for ANTXR2, the high-affinity receptor for anthrax toxins. Anthrax toxins are composed of protective antigen (PA), which binds to ANTXR2, and the protein cargoes edema factor (EF) and lethal factor (LF).

Developing nociceptor-selective treatments for acute and chronic pain.

Despite substantial efforts dedicated to the development of new, nonaddictive analgesics, success in treating pain has been limited. Clinically available analgesic agents generally lack efficacy and may have undesirable side effects. Traditional target-based drug discovery efforts that generate compounds with selectivity for single targets have a high rate of attrition because of their poor clinical efficacy.

Bidirectional flow of the funny current (I) during the pacemaking cycle in murine sinoatrial node myocytes.

Sinoatrial node myocytes (SAMs) act as cardiac pacemaker cells by firing spontaneous action potentials (APs) that initiate each heartbeat. The funny current (I) is critical for the generation of these spontaneous APs; however, its precise role during the pacemaking cycle remains unresolved. Here, we used the AP-clamp technique to quantify I during the cardiac cycle in mouse SAMs.

Cannabidiol Inhibition of Murine Primary Nociceptors: Tight Binding to Slow Inactivated States of Na1.8 Channels.

The nonpsychoactive phytocannabinoid cannabidiol (CBD) has been shown to have analgesic effects in animal studies but little is known about its mechanism of action. We examined the effects of CBD on intrinsic excitability of primary pain-sensing neurons. Studying acutely dissociated capsaicin-sensitive mouse DRG neurons at 37°C, we found that CBD effectively inhibited repetitive action potential firing, from 15-20 action potentials evoked by 1 s current injections in control to 1-3 action potentials with 2 μm CBD.

Automated Audiometry in Quiet and Simulated Exam Room Noise for Listeners with Normal Hearing and Impaired Hearing.

Background: Up to 80% of audiograms could be automated which would allow more time for provision of specialty services. Ideally, automated audiometers would provide accurate results for listeners with impaired hearing as well as normal hearing. Additionally, accurate results should be provided both in controlled environments like a sound-attenuating room but also in test environments that may support greater application when sound-attenuating rooms are unavailable.

Inhibition of inflammatory pain and cough by a novel charged sodium channel blocker.

Background And Purpose: Many pain-triggering nociceptor neurons express TRPV1 or TRPA1, cation-selective channels with large pores that enable permeation of QX-314, a cationic analogue of lidocaine. Co-application of QX-314 with TRPV1 or TRPA1 activators can silence nociceptors. In this study, we describe BW-031, a novel more potent cationic sodium channel inhibitor, and test whether its application alone can inhibit pain associated with tissue inflammation and whether this strategy can also inhibit cough.

BK Channel Regulation of Afterpotentials and Burst Firing in Cerebellar Purkinje Neurons.

BK calcium-activated potassium channels have complex kinetics because they are activated by both voltage and cytoplasmic calcium. The timing of BK activation and deactivation during action potentials determines their functional role in regulating firing patterns but is difficult to predict a priori. We used action potential clamp to characterize the kinetics of voltage-dependent calcium current and BK current during action potentials in Purkinje neurons from mice of both sexes, using acutely dissociated neurons that enabled rapid voltage clamp at 37°C.

Risk Factors for Complications Associated With Minimally Invasive Medial Displacement Calcaneal Osteotomy.

Background: Few studies have reported the outcomes following minimally invasive medial displacement calcaneal osteotomy (MDCO) for correction of pes planovalgus deformities.

Methods: Charts were retrospectively reviewed for consecutive patients who underwent minimally invasive MDCO procedures by a single surgeon from 2013 to 2019 with more than 3 months of follow-up. A total of 160 consecutive patients who underwent 189 minimally invasive MDCO procedures were included in the study.

Early Bony Hip Reconstructive Surgery for Hip Subluxation in Children With Severe Cerebral Palsy.

Hip subluxation occurs frequently in children with severe cerebral palsy. This retrospective study examined the effects of age and type of bony surgery on radiographic outcomes of children with severe cerebral palsy who were treated for hip subluxation. The study included nonambulatory children with cerebral palsy undergoing bony hip reconstructive surgery consisting of proximal femoral varus derotational osteotomy (VDRO) alone or combined with pelvic osteotomy.

Imaging in Vaping-associated Lung Injury: Beyond the Haze.

E-cigarette or vaping, product associated lung injury is a rampant public health issue with a total of 2807 reported hospitalized patients in the United States as of February 18, 2020. Limited data, non-specific symptoms, non-responsiveness to antibiotics, and the lack of a specific biomarker, make it a diagnosis of exclusion. Overlap of clinical and imaging findings with other ongoing respiratory illness (MERS, SARS and COVID-19) poses a challenge in accurate diagnosis.

Biomechanical Comparison of Hook Plate vs Headless Compression Screw Fixation of Large Fifth Metatarsal Base Avulsion Fractures.

Background: Debate exists on the optimum fixation construct for large avulsion fractures of the fifth metatarsal base. We compared the biomechanical strength of 2 headless compression screws vs a hook plate for fixation of these fractures.

Methods: Large avulsion fractures were simulated on 10 matched pairs of fresh-frozen cadaveric specimens.

Load to Failure and Stiffness of Interference Screw vs Pulvertaft Weave for Distal Fixation in Peroneal Allograft Reconstruction.

Background: Allograft reconstruction of the peroneal tendons is an option for treatment of major tears of 1 or both peroneal tendons. No consensus on a superior distal fixation method has been reported. The purpose of the study was to compare load to failure and stiffness of a Pulvertaft weave (PTW) through a residual tendon stump to direct-to-bone interference screw (IS) fixation.

Lidocaine Binding Enhances Inhibition of Nav1.7 Channels by the Sulfonamide PF-05089771.

PF-05089771 is an aryl sulfonamide Nav1.7 channel blocker that binds to the inactivated state of Nav1.7 channels with high affinity but binds only weakly to channels in the resting state.