Rejected

This study aimed to investigate the effect of chronic traction apophysitis of the medial epicondyle (MEC) on medial ulnar collateral ligament (MUCL) insufficiency in high school baseball players.

Pulmonary functions are controlled by afferent nerves which convey peripheral information to the central nervous system. Cell bodies of these afferent nerves are found predominantly in the vagal ganglia (VG) with some in the dorsal root ganglia (DRG). These neurons are highly heterogeneous based on their developmental origins, anatomical sources, and physiochemical properties. Vagal ganglia are composed of nodose (placode origin), and jugular ganglia (neural crest origin). Most vagal afferent nerves innervating the lung are unmyelinated C-fibers which are activated by capsaicin, the selective agonist of transient receptor potential vanilloid 1 (TRPV1). TRPV1 detects noxious stimuli and its activation results in defensive reflexes. Both nodose and jugular ganglia have TRPV1+ nociceptive C-fiber but it is not currently known where they terminate within the lung. In addition, there is lack of information regarding pulmonary afferent nerves projecting from the DRG, which also are derived from the neural crest. Here, we used cell-type specific Cre knock-in strains in combination with injections with adeno-associated viral vectors (AAV) carrying a Cre-sensitive reporter allele to label specific subsets of vagal and DRG afferent nerves in lung. Pirt-cre (marker for all sensory neurons), TRPV1-cre (nociceptors) and Tac1-cre (jugular, DRG) strains received unilateral injections of AAV9-flex-EGFP into nodose ganglia, and/or AAV9-flex-tdTomato into thoracic DRG (between T1-T3). VG, DRG and lung were collected 4 weeks post-injection and cryosectioned. Native fluorescent signals were amplified using anti-DsRed and anti-GFP immunoreactivity, and images were taken using an Andor Dragonfly spinning disk confocal microscope. Viral transfection was confirmed by expression of GFP in VG or tdTomato in DRG. Lung images were analyzed for VG/DRG nerve innervations based on diameters of airways (small: ≤175 µm, medium: 175-376 µm, large: ≥376 µm). >95% of the conducting airways was innervated by vagal Pirt+ afferent nerves. About half of the conducting airways also had vagal Pirt+ fibers which projected out into the alveolar regions (mean distance 200±50 µm). Only 20% of the airways were innervated by Pirt+ DRG fibers, none of which projected into the alveolar regions. Vagal-Pirt(+) nerves innervate most of the airways regardless of size, but DRG-Pirt(+) nerves innervate mostly large diameter airways. ~75% of airways are innervated by vagal TRPV1+ afferents, some of which project into the alveolar regions. There is virtually no TRPV1+ innervation of the lung projected from the DRG. ~75% of large/medium sized airways were innervated by vagal originating nerves in Tac1-cre, but none of these fibers projected into the alveolar spaces. Some large diameter airways were also innervated by Tac1+ fibers from DRG neurons. Together, our approach with the unilateral intraganglionic injections of AAV, into the VG and DRG, carrying a cre-dependent reporter allele allows identification of specific subsets of afferent nerves in the VG and DRG innervating the lung.

Kratom (Mitragyna speciosa) is consumed by 10-15 million individuals in the US for its mood-elevating effects, as an alternative to traditional opiates for pain relief and to attenuate opiate withdrawal symptoms. Complex natural products, such as kratom, contain a variety of chemicals whose combined effects can only be understood by the meticulous identification and characterization of the individual chemicals and their effects in preclinical model systems. Twenty-five indole and oxindole kratom alkaloids were evaluated for mu (MOR), delta (DOR) and kappa (KOR) opiate receptors binding affinities, opiate receptor mediated G-protein activation, inhibition of forskolin stimulated cAMP accumulation and b-arrestin2 recruitment. Several indole and oxindole alkaloids exhibited partial agonism at the MOR (7-hydroxymitragynine, corynoxine A > epiallo-isopaynantheine, isospeciofoline, speciociliatine, corynoxine B > mitragynine, 3-epicorynoxine B > paynantheine and speciogynine) – all of which also exhibited strong G protein bias. Mitraciliatine and isopaynantheine were weak MOR antagonists. Speciophylline exhibited positive allosteric modulatory activity at the MOR as evidenced by increased affinity of DAMGO binding and potentiation of [met]-enkephalin-induced inhibition of forskolin stimulated cAMP activity in the absence of intrinsic activity. Corynoxine A induced displayed similar affinity at the mu opiate receptor as 7 hydroxymitragynine but was less potent in the nociceptive hot plate assay and the mechanical allodynia von Frey test. Corynoxine did not significantly alter respiration or heart rate or induce a conditioned place preference. Results demonstrate the pharmacological complexity of kratom alkaloids and have important implications for determining the combined effects of less abundant indole and oxindole alkaloids with regard to the therapeutic as well as potential harmful effects of kratom.

Ischemic reperfusion during stroke treatment increases the pathological progression of stroke. Reperfusion with r-TPA and mechanical thrombectomy applied to stroke patients increases the risk of intracerebral hemorrhage. In addition, various molecular signals initiated during ischemic reperfusion exacerbate the disease due to increased endothelial permeability. However, a detailed molecular therapeutic regimen with r-TPA and mechanical thrombectomy could limit the detrimental effects and increase the survival rate. Lysophosphatidic acid (LPA) is a bioactive phospholipid regulated in physiological and pathological conditions. LPA is produced by the enzyme autotaxin (ATX). ATX and LPA have been observed to deteriorate physiological status in various diseases such as myocardial infarction, Alzheimer's disease, liver fibrosis, neuropathic pain etc. In cerebral ischemic-reperfusion, the ATX-LPA axis could initiate the endothelium disruption.

G protein-coupled receptors (GPCRs) regulate diverse physiological processes in health and disease through activation of the heterotrimeric G protein subunits, Gα and Gβγ. G proteins in turn activate effector enzymes, such as phospholipase C β (PLCβ), to produce second messengers. The PLCβ subfamily has modest basal activity which is robustly increased by direct binding of Gα . PLCβ1-3 are also directly activated by Gβγ. PLCβ hydrolyzes phosphatidylinositol-4,5-bisphosphate (PIP ) to generate diacylglycerol (DAG) and inositol-1,4,5 trisphosphate (IP ), activating protein kinase C (PKC) and increasing intracellular Ca . Inhibition of G protein-dependent activation of PLCβ has been shown to have therapeutic potential in multiple pathologies, including inflammation, cardiac hypertrophy, opioid analgesia, and cancer. Much has been learned about how Gα binds to and activates PLCβ from structural and functional studies, but there is no consensus as to the binding site for Gβγ on PLCβ, or its mechanism of activation. Gα and Gβγ synergistically activate PLCβ, suggesting the G proteins bind to nonoverlapping sites on the lipase and activate through independent mechanisms. Atomic resolution structures of the Gβγ-PLCβ complex are needed to fully understand the mechanism of Gβγ activation of PLCβ. We have isolated a stable, active Gβγ-PLCβ3 complex and are using single particle cryo-electron microscopy (cryo-EM) to investigate its structure. We have so far identified two particle populations using heterogeneous refinement, and generated reconstructions at 4 and 7 Å resolution. The structures reveal strong density for Gβγ binding to PLCβ through multivalent interactions with its pleckstrin homology (PH) domain, EF hands, and C2 domain, dispelling controversies about the Gβγ binding site that have persisted for over three decades. The greatest difference between structures is the position of Gβγ with respect to the PH-EF hand interface. Surprisingly, one conformation of the Gβγ-PLCβ complex is compatible with simultaneous binding of Gα , which has not been reported in any other Gβγ-effector enzyme structure. This suggests that Gβγ may also function as a scaffold for Gα and PLCβ, in which a pre-activated complex is maintained at the membrane. Dissociation of activated Gα would allow rotation of Gβγ, leading to full engagement of PLCβ and maximum activation. Further investigation into the scaffolding and activating roles of Gβγ in PLCβ activation will be essential in developing chemical probes to selectively target this pathway.

Opioid drugs provide effective pain relief but come with considerable side-effects including addiction and respiratory depression which can be lethal with overdose. During the COVID19 pandemic, the opioid epidemic reached almost 100,000 deaths in the United States, highlighting the urgent need to identify pain killers with reduced liability so they can be safely prescribed. One approach to develop safe pain killers is to combine existing opioid analgesics with drugs reducing respiratory depression. Using our novel biotechnology platforms in larval zebrafish, we propose to identify new molecular targets and drugs with potent analgesic properties, reduced respiratory liability, and without addictive properties.

A 43-year-old woman presented to our hospital with headache accompanied with nausea and intermittent vomiting without abdominal pain. The patient had undergone ventriculoperitoneal shunt placement for hydrocephalus owing to quadrigeminal cistern arachnoid cyst. Cranial computed tomography demonstrated enlarged bilateral ventricles, and the abdominal radiograph demonstrated a reverse U-shaped catheter that seemed to have been fractured in the left peritoneal cavity.

The choroid plexus has been shown to play a crucial role in CNS inflammation. Previous studies found larger choroid plexus in multiple sclerosis (MS) compared with healthy controls. However, it is not clear whether the choroid plexus is similarly involved in MS and in neuromyelitis optica spectrum disorder (NMOSD). Thus, the aim of this study was to compare the choroid plexus volume in MS and NMOSD.