PI3K Isoforms in B Cells.

Phosphatidylinositol-3-kinases (PI3K) control many aspects of cellular activation and differentiation and play an important role in B cells biology. Three different classes of PI3K have been described, all of which are expressed in B cells. However, it is the class IA PI3Ks, and the p110δ catalytic subunit in particular, which seem to play the most critical role in B cells. Here we discuss the important role that class IA PI3K plays in B cell development, activation and differentiation, as well as examine what is known about the other classes of PI3Ks in B cells.

Correlation of Calculated Vancomycin Trough Concentrations and Exposure: A Monte Carlo Simulation.

BACKGROUND: Current recommendations are to dose vancomycin to target 24-hour area under the curve (AUC) of 400-600 mg·h/L to optimize efficacy and safety. Limited data support AUC monitoring, and some centers continue to use trough concentrations. A target of 10-20 mg/L has been proposed to reduce nephrotoxicity risk. OBJECTIVE: To use previously published pharmacokinetic equations in a Monte Carlo simulation relating AUC exposure to trough concentrations when targeting an AUC between 400 and 600 mg·h/L. METHODS: Previously published pharmacokinetic data were used as input parameters for a Monte Carlo simulation using previously published formulae to correlate AUC to simulated trough concentrations. Pharmacokinetic parameters were assumed to occur in a normal distribution pattern. We excluded irrelevant simulated cases. Maintenance doses of 15 mg/kg were rounded to the nearest 250 mg. Calculated trough concentrations for AUCs of both 400 and 600 mg·h/L were evaluated in each simulation. RESULTS: A total of 10 000 Monte Carlo simulations were performed. Targeting an AUC of 400 mg·h/L resulted in a mean trough concentration of 10.3 ± 0.8 mg/L. Targeting an AUC of 600 mg·h/L resulted in a mean trough concentration of 15.4 ± 1.2 mg/L. CONCLUSION AND RELEVANCE: We demonstrate that a lower trough concentration range may be supported by an AUC of 400-600 mg·h/L, which may reduce risk and rates of nephrotoxicity without compromising previously established efficacious target trough concentrations.

Distinct role of long 3' UTR BDNF mRNA in spine morphology and synaptic plasticity in hippocampal neurons.

The brain produces two brain-derived neurotrophic factor (BDNF) transcripts, with either short or long 3' untranslated regions (3' UTRs). The physiological significance of the two forms of mRNAs encoding the same protein is unknown. Here, we show that the short and long 3' UTR BDNF mRNAs are involved in different cellular functions. The short 3' UTR mRNAs are restricted to somata, whereas the long 3' UTR mRNAs are also localized in dendrites. In a mouse mutant where the long 3' UTR is truncated, dendritic targeting of BDNF mRNAs is impaired. There is little BDNF in hippocampal dendrites despite normal levels of total BDNF protein. This mutant exhibits deficits in pruning and enlargement of dendritic spines, as well as selective impairment in long-term potentiation in dendrites, but not somata, of hippocampal neurons. These results provide insights into local and dendritic actions of BDNF and reveal a mechanism for differential regulation of subcellular functions of proteins.

Ketamine-precipitated syndrome of inappropriate antidiuretic hormone secretion in a patient with persistent lumbar pain: a case report.

PURPOSE: To report on an unusual case of ketamine-precipitated syndrome of inappropriate antidiuretic hormone secretion (SIADH) in an individual managed by an outpatient pain specialty team. CLINICAL FEATURES: A 78-yr-old male presented to the emergency department with lethargy, malaise, nausea, and abdominal bloating three days following intravenous ketamine infusion for intractable postsurgical lumbar radicular pain with neuropathic features. The patient had a history of resected prostate cancer, hyperlipidemia, chronic kidney disease, and spinal stenosis and the cause of his symptoms was investigated. He was found to be hyponatremic and the treating team excluded reversible surgical and medical causes. A Naranjo score of 7 was calculated, suggesting that the correlation between ketamine and hyponatremia was "likely." Hence, a diagnosis of ketamine-precipitated SIADH was made. The patient was treated with fluid restriction and symptoms were controlled with antiemetics. He returned to baseline function with resolution of the hyponatremia within three days of discharge. CONCLUSION: This case is of clinical importance for providers using ketamine in the field of pain management as the effect of this medication reaction can be profound. Clinicians should develop an awareness that ketamine can potentiate adverse effects such as SIADH and they should monitor, detect, and manage as appropriate.

RéSUMé: OBJECTIF: Nous signalons un cas inhabituel de syndrome de sécrétion inappropriée d'hormones antidiurétiques (SIADH - syndrome of inappropriate antidiuretic hormone secretion) précipité par la kétamine chez une personne prise en charge par une équipe spécialisée en douleur en soins ambulatoires. CARACTéRISTIQUES CLINIQUES: Un homme de 78 ans s'est présenté à l'urgence souffrant de léthargie, de malaise, de nausées et de ballonnements abdominaux trois jours après avoir reçu une perfusion intraveineuse de kétamine pour le traitement d'une douleur radiculaire lombaire postopératoire rebelle avec des caractéristiques neuropathiques. Le patient avait des antécédents de résection de cancer de la prostate, d'hyperlipidémie, d'insuffisance rénale chronique et de sténose du canal rachidien, et la cause de ses symptômes a été évaluée. Il s'est avéré hyponatrémique et l'équipe soignante a exclu les causes chirurgicales et médicales réversibles. Un score Naranjo de 7 a été calculé, suggérant que la corrélation entre la kétamine et l'hyponatrémie était « probable ¼. Par conséquent, un diagnostic de SIADH précipité par la kétamine a été posé. Le patient a été traité par restriction hydrique et les symptômes ont été contrôlés par des antiémétiques. Il est revenu à son fonctionnement de référence avec la résolution de l'hyponatrémie dans les trois jours suivant son congé. CONCLUSION: Ce cas est important d'un point de vue clinique pour les praticiens qui utilisent la kétamine pour la prise en charge de la douleur, car l'effet de cette réaction médicamenteuse peut être profond. Les cliniciens devraient prendre conscience que la kétamine peut augmenter des effets indésirables tels que le SIADH et ils devraient monitorer, dépister et prendre en charge le patient, le cas échéant.

Kinase pathway inhibition restores PSD95 induction in neurons lacking fragile X mental retardation protein.

Fragile X syndrome (FXS) is the leading monogenic cause of autism and intellectual disability. FXS is caused by loss of expression of fragile X mental retardation protein (FMRP), an RNA-binding protein that regulates translation of numerous mRNA targets, some of which are present at synapses. While protein synthesis deficits have long been postulated as an etiology of FXS, how FMRP loss affects distributions of newly synthesized proteins is unknown. Here we investigated the role of FMRP in regulating expression of new copies of the synaptic protein PSD95 in an in vitro model of synaptic plasticity. We find that local BDNF application promotes persistent accumulation of new PSD95 at stimulated synapses and dendrites of cultured neurons, and that this accumulation is absent in FMRP-deficient mouse neurons. New PSD95 accumulation at sites of BDNF stimulation does not require known mechanisms regulating FMRP-mRNA interactions but instead requires the PI3K-mTORC1-S6K1 pathway. Surprisingly, in FMRP-deficient neurons, BDNF induction of new PSD95 accumulation can be restored by mTORC1-S6K1 blockade, suggesting that constitutively high mTORC1-S6K1 activity occludes PSD95 regulation by BDNF and that alternative pathways exist to mediate induction when mTORC1-S6K1 is inhibited. This study provides direct evidence for deficits in local protein synthesis and accumulation of newly synthesized protein in response to local stimulation in FXS, and supports mTORC1-S6K1 pathway inhibition as a potential therapeutic approach for FXS.

The Effect of Helium Ion Radiation on the Material Properties of Bone.

Ionizing radiation, from both space and radiation therapy, is known to affect bone health. While there have been studies investigating changes in bone density and microstructure from radiation exposure, the effects of radiation on material properties are unknown. The current study addresses this gap by assessing bone material property changes in rats exposed to helium-4 radiation through spherical micro-indentation. Rats were exposed to a single dose of 0, 5, and 25 cGy whole body helium-4 radiation. Animals were euthanized at 7, 30, 90, or 180-days after exposure. Spherical micro-indentation was performed on axial cross sections of the femur cortical bone to determine instantaneous and relaxed shear moduli. At 90-days after exposure, the 25 cGy exposure caused a significant decline in shear modulus compared to control and 5 cGy groups. The instantaneous modulus decreased 33% and the relaxed modulus decreased 32% as compared to the sham group. This decline was followed by a recovery of both moduli, which was observed by 180-days after exposure; at 180 days, the moduli were no longer statistically different from those at 7 or 30 days. The observed decrease at 90 days, followed by recovery to baseline levels, can be attributed to the biological mechanisms involved in bone formation that were affected by radiation, bone turnover, and systemic changes in hormones due to radiation exposure. Continued assessment of the mechanisms that drive such a response in material properties may enable identification of pathways for therapeutic countermeasures against radiation exposure.

FMRP Interacts with RARα in Synaptic Retinoic Acid Signaling and Homeostatic Synaptic Plasticity.

The fragile X syndrome (FXS) is an X-chromosome-linked neurodevelopmental disorder with severe intellectual disability caused by inactivation of the fragile X mental retardation 1 (FMR1) gene and subsequent loss of the fragile X mental retardation protein (FMRP). Among the various types of abnormal synaptic function and synaptic plasticity phenotypes reported in FXS animal models, defective synaptic retinoic acid (RA) signaling and subsequent defective homeostatic plasticity have emerged as a major synaptic dysfunction. However, the mechanism underlying the defective synaptic RA signaling in the absence of FMRP is unknown. Here, we show that RARα, the RA receptor critically involved in synaptic RA signaling, directly interacts with FMRP. This interaction is enhanced in the presence of RA. Blocking the interaction between FMRP and RARα with a small peptide corresponding to the critical binding site in RARα abolishes RA-induced increases in excitatory synaptic transmission, recapitulating the phenotype seen in the Fmr1 knockout mouse. Taken together, these data suggest that not only are functional FMRP and RARα necessary for RA-dependent homeostatic synaptic plasticity, but that the interaction between these two proteins is essential for proper transcription-independent RA signaling. Our results may provide further mechanistic understanding into FXS synaptic pathophysiology.

Molecular and cellular mechanisms underlying defective antibody responses.

Primary immune deficiency is caused by genetic mutations that result in immune dysfunction and subsequent susceptibility to infection. Over the last decade there has been a dramatic increase in the number of genetically defined causes of immune deficiency including those which affect B-cell function. This has not only identified critical nonredundant pathways that control the generation of protective antibody responses but also revealed that immunodeficiency and autoimmunity are often closely linked. Here we explore the molecular and cellular mechanisms of these rare monogenic conditions that disrupt antibody production, which also have implications for understanding the causes of more common polygenic immune dysfunction.

A Mouse Model for Skeletal Structure and Function Changes Caused by Radiation Therapy and Estrogen Deficiency.

Radiation therapy and estrogen deficiency can damage healthy bone and lead to an increased fracture risk. The goal of this study is to develop a mouse model for radiation therapy using a fractionated biologically equivalent dose for cervical cancer treatment in both pre- and postmenopausal women. Thirty-two female C57BL/6 mice 13 weeks of age were divided into four groups: Sham + non-irradiated (SHAM + NR), Sham + irradiated (SHAM + IRR), ovariectomy + non-irradiated (OVX + NR) and ovariectomy + irradiated (OVX + IRR). The irradiated mice received a 6 Gy dose of X-rays to the hindlimbs at Day 2, Day 4 and Day 7 (18 Gy total). Tissues were collected at Day 35. DEXA, microCT analysis and FEA were used to quantify structural and functional changes at the proximal tibia, midshaft femur, proximal femur and L1 vertebra. There was a significant (p < 0.05) decline in proximal tibia trabecular BV/TV from (1) IRR compared to NR mice within Sham (- 46%) and OVX (- 41%); (2) OVX versus Sham within NR mice (- 36%) and IRR mice (- 30%). With homogenous material properties applied to the proximal tibia mesh using FEA, there was (1) an increase in whole bone (trabecular + cortical) structural stiffness from IRR compared to NR mice within Sham (+ 10%) and OVX (+ 15%); (2) a decrease in stiffness from OVX versus Sham within NR mice (- 18%) and IRR mice (- 14%). Fractionated irradiation and ovariectomy both had a negative effect on skeletal microarchitecture. Ovariectomy had a systemic effect, while skeletal radiation damage was largely specific to trabecular bone within the X-ray field.

Activating PIK3CD mutations impair human cytotoxic lymphocyte differentiation and function and EBV immunity.

BACKGROUND: Germline gain-of function (GOF) mutations in PIK3CD, encoding the catalytic p110δ subunit of phosphoinositide 3-kinase (PI3K), result in hyperactivation of the PI3K-AKT-mechanistic target of rapamycin pathway and underlie a novel inborn error of immunity. Affected subjects exhibit perturbed humoral and cellular immunity, manifesting as recurrent infections, autoimmunity, hepatosplenomegaly, uncontrolled EBV and/or cytomegalovirus infection, and increased incidence of B-cell lymphoproliferation, lymphoma, or both. Mechanisms underlying disease pathogenesis remain unknown. OBJECTIVE: Understanding the cellular and molecular mechanisms underpinning inefficient surveillance of EBV-infected B cells is required to understand disease in patients with PIK3CD GOF mutations, identify key molecules required for cell-mediated immunity against EBV, and develop immunotherapeutic interventions for the treatment of this and other EBV-opathies. METHODS: We studied the consequences of PIK3CD GOF mutations on the generation, differentiation, and function of CD8+ T cells and natural killer (NK) cells, which are implicated in host defense against infection with herpesviruses, including EBV. RESULTS: PIK3CD GOF total and EBV-specific CD8+ T cells were skewed toward an effector phenotype, with exaggerated expression of markers associated with premature immunosenescence/exhaustion and increased susceptibility to reactivation-induced cell death. These findings were recapitulated in a novel mouse model of PI3K GOF mutations. NK cells in patients with PIK3CD GOF mutations also exhibited perturbed expression of differentiation-associated molecules. Both CD8+ T and NK cells had reduced capacity to kill EBV-infected B cells. PIK3CD GOF B cells had increased expression of CD48, programmed death ligand 1/2, and CD70. CONCLUSIONS: PIK3CD GOF mutations aberrantly induce exhaustion, senescence, or both and impair cytotoxicity of CD8+ T and NK cells. These defects might contribute to clinical features of affected subjects, such as impaired immunity to herpesviruses and tumor surveillance.

Activating mutations in PIK3CD disrupt the differentiation and function of human and murine CD4+ T cells.

BACKGROUND: Gain-of-function (GOF) mutations in PIK3CD cause a primary immunodeficiency characterized by recurrent respiratory tract infections, susceptibility to herpesvirus infections, and impaired antibody responses. Previous work revealed defects in CD8+ T and B cells that contribute to this clinical phenotype, but less is understood about the role of CD4+ T cells in disease pathogenesis. OBJECTIVE: We sought to dissect the effects of increased phosphoinositide 3-kinase (PI3K) signaling on CD4+ T-cell function. METHODS: We performed detailed ex vivo, in vivo, and in vitro phenotypic and functional analyses of patients' CD4+ T cells and a novel murine disease model caused by overactive PI3K signaling. RESULTS: PI3K overactivation caused substantial increases in numbers of memory and follicular helper T (TFH) cells and dramatic changes in cytokine production in both patients and mice. Furthermore, PIK3CD GOF human TFH cells had dysregulated phenotype and function characterized by increased programmed cell death protein 1, CXCR3, and IFN-γ expression, the phenotype of a TFH cell subset with impaired B-helper function. This was confirmed in vivo in which Pik3cd GOF CD4+ T cells also acquired an aberrant TFH phenotype and provided poor help to support germinal center reactions and humoral immune responses by antigen-specific wild-type B cells. The increase in numbers of both memory and TFH cells was largely CD4+ T-cell extrinsic, whereas changes in cytokine production and TFH cell function were cell intrinsic. CONCLUSION: Our studies reveal that CD4+ T cells with overactive PI3K have aberrant activation and differentiation, thereby providing mechanistic insight into dysfunctional antibody responses in patients with PIK3CD GOF mutations.

Immune Dysregulation and Disease Pathogenesis due to Activating Mutations in PIK3CD-the Goldilocks' Effect.

"This porridge is too hot!" she exclaimed. So, she tasted the porridge from the second bowl. "This porridge is too cold," she said. So, she tasted the last bowl of porridge. "Ahhh, this porridge is just right," she said happily and she ate it all up. While this describes the adventures of Goldilocks in the classic fairytale "The Story of Goldilocks and the Three Bears," it is an ideal analogy for the need for balanced signaling mediated by phosphatidylinositol-3-kinase (PI3K), a key signaling hub in immune cells. Either too little or too much PI3K activity is deleterious, even pathogenic-it needs to be "just right"! This has been elegantly demonstrated by the identification of inborn errors of immunity in key components of the PI3K pathway, and the impact of these mutations on immune regulation. Detailed analyses of patients with germline activating mutations in PIK3CD, as well as the parallel generation of novel murine models of this disease, have shed substantial light on the role of PI3K in lymphocyte development and differentiation, and mechanisms of disease pathogenesis resulting not only from PIK3CD mutations but genetic lesions in other components of the PI3K pathway. Furthermore, by being able to pharmacologically target PI3K, these monogenic conditions have provided opportunities for the implementation of precision medicine as a therapy, as well as to gain further insight into the consequences of modulating the PI3K pathway in clinical settings.

Minimally invasive direct pars repair with cannulated screws and recombinant human bone morphogenetic protein: case series and review of the literature.

OBJECTIVE The objective of this study was to describe the use of a minimally invasive surgical treatment of lumbar spondylolysis in athletes by a fluoroscopically guided direct pars screw placement with recombinant human bone morphogenetic protein-2 (rhBMP-2) and to report on clinical and radiographic outcomes. METHODS A retrospective review was conducted of all patients treated surgically for lumbar spondylolysis via a minimally invasive direct pars repair with cannulated screws. Demographic information, clinical features of presentation, perioperative and intraoperative radiographic imaging, and postoperative data were collected. A 1-cm midline incision was performed for the placement of bilateral pars screws utilizing biplanar fluoroscopy, followed by placement of a fully threaded 4.0-mm-diameter titanium cannulated screw. A tubular table-mounted retractor was utilized for direct pars fracture visualization and debridement through a separate incision. The now-visualized pars fracture could then be decorticated, with care taken not to damage the titanium screw when using a high-speed drill. Local bone obtained from the curettage was then placed in the defect with 1.05 mg rhBMP-2 divided equally between the bilateral pars defects. RESULTS Nine patients were identified (mean age 17.7 ± 3.42 years, range 14-25 years; 6 male and 3 female). All patients had bilateral pars fractures of L-4 (n = 4) or L-5 (n = 5). The mean duration of preoperative symptoms was 17.22 ± 13.2 months (range 9-48 months). The mean operative duration was 189 ± 29 minutes (range 151-228 minutes). The mean intraoperative blood loss was 17.5 ± 10 ml (range 10-30 ml). Radiographic follow-up was available in all cases; the mean length of time from surgery to the most recent imaging study was 30.8 ± 23.3 months (range 3-59 months). The mean hospital length of stay was 1.13 ± 0.35 days (range 1-2 days). There were no intraoperative complications. CONCLUSIONS Lumbar spondylolysis treatment with a minimally invasive direct pars repair is a safe and technically feasible option that minimizes muscle and soft-tissue dissection, which may particularly benefit adolescent patients with a desire to return to a high level of physical activity.

AMPA receptor/TARP stoichiometry visualized by single-molecule subunit counting.

Members of the transmembrane AMPA receptor-regulatory protein (TARP) family modulate AMPA receptor (AMPA-R) trafficking and function. AMPA-Rs consist of four pore-forming subunits. Previous studies show that TARPs are an integral part of the AMPA-R complex, acting as accessory subunits for mature receptors in vivo. The TARP/AMPA-R stoichiometry was previously measured indirectly and found to be variable and dependent on TARP expression level, with at most four TARPs associated with each AMPA-R complex. Here, we use a single-molecule technique in live cells that selectively images proteins located in the plasma membrane to directly count the number of TARPs associated with each AMPA-R complex. Although individual GFP-tagged TARP subunits are observed as freely diffusing fluorescent spots on the surface of Xenopus laevis oocytes when expressed alone, coexpression with AMPA-R-mCherry immobilizes the stargazin-GFP spots at sites of AMPA-R-mCherry, consistent with complex formation. We determined the number of TARP molecules associated with each AMPA-R by counting bleaching steps for three different TARP family members: γ-2, γ-3, and γ-4. We confirm that the TARP/AMPA-R stoichiometry depends on TARP expression level and discover that the maximum number of TARPs per AMPA-R complex falls into two categories: up to four γ-2 or γ-3 subunits, but rarely above two for γ-4 subunit. This unexpected AMPA-R/TARP stoichiometry difference has important implications for the assembly and function of TARP/AMPA-R complexes.

Characterization and flocculation mechanism of a bioflocculant from potato starch wastewater.

This study investigated the characterization and flocculation mechanism of a bioflocculant prepared using potato starch wastewater. The optimal culture conditions of this strain were determined as 4 g K2HPO4, 2 g KH2PO4, 0.2 g MgSO4, 0.1 g NaCl, and 2.0 g urea dissolved in 1.0 L potato starch wastewater with no need of adding carbon sources or adjusting pH value. Production of this bioflocculant was positively associated with cell growth, and a highest value of 0.81 g/L was obtained. During the kaolin suspension flocculation, charge neutralization and interparticle bridging were proposed as the main reasons for enhanced performance. Further, with potato starch wastewater, chemical oxygen demand (COD) and turbidity removal rates reached 52.4 and 81.7 %, respectively, at pH 7.5 when the bioflocculant dose was adjusted to 30 mg/L.

Effects of manipulating cyclic duration and pH on fermentative hydrogen production in an anaerobic sequencing batch reactor.

The effects of cyclic duration and pH on biological hydrogen production were investigated in an anaerobic sequencing batch reactor. Experiments were conducted using cyclic duration of (4, 8, and 12 h) in combination with pH (4, 5, and 6) in a 3 × 3 factorial design, while hydraulic retention time and organic loading rate were maintained at 24 h and 10.3 g COD L(-1).d(-1), respectively. At pH 4, the effect of cyclic duration on hydrogen production was found to be insignificant. However, in runs with pH 5 and 6, a shorter cyclic duration of 4 h led to lower hydrogen productivity. The operational condition (pH 6, cyclic duration 12 h) induced higher hydrogen production rate of 2.3 ± 0.6 L H2/L reactor.d, whereas higher hydrogen yield of 2.2 ± 0.4 mol H2/mol sucrose was achieved at pH 5 and the same 12 h cyclic duration. The differences in hydrogen production were not statistically significant between 8 h and 12 h cyclic duration. Higher hydrogen production rates were associated with biomass (mixed liquor volatile suspended solids) concentration ranging from 8-13 g L(-1), but further increase in biomass growth was not accompanied by increased hydrogen production. Furthermore, a food-to-microorganism ratio of 0.84 was found to result in higher hydrogen production rate.

A Simulation-Based Assessment of Levetiracetam Concentrations Following Fixed and Weight-Based Loading Doses: A Meta-Regression and Pharmacokinetic Modeling Analysis.

Current recommendations for refractory status epilepticus (SE) unresponsive to benzodiazepines suggest a loading dose of levetiracetam (LEV) of 60 mg/kg to a maximum of 4500 mg. LEV therapeutic drug monitoring can help guide therapy and is garnering increasing attention. The objective of this study is to simulate the probability of target attainment (PTA) of fixed dose and weight-based loading doses of LEV with respect to established therapeutic target concentrations. Meta-regression of the current literature was performed to evaluate the relationship between intravenous LEV loading dose and seizure cessation in refractory SE patients. A previously published pharmacokinetic model was used to simulate the PTA capacity of competing single intravenous dosing schemes (fixed vs weight-based dosing) to achieve maximum (Cpeak) and 12-h (C12h) plasma concentrations that exceed 12 mg/L. The meta-regression indicated that dosage was not a statistically significant modulator of seizure control at dosages between 20 and 60 mg/kg. Stochastic simulations showed all dosing schemes achieved plasma Cpeak >12 mg/L, but C12h levels were <12 mg/L in subjects over 60 kg with a fixed dose ≤2000 mg or in subjects <60 kg with a weight-based dose <30 mg/kg. Dosages of 40 and 60 mg/kg provided ≥90% PTAs across all weights. Using a weight-based loading dose of 40 mg/kg, up to a suggested maximum of 4500 mg, improves the likelihood of achieving a sustained therapeutic drug concentration after the initial LEV dose, whereas fixed <3000 mg may not achieve the desired concentration before maintenance dosing.

Using quality improvement approaches to increase emergency department provider engagement in research participant enrollment during COVID-19 and opioid overdose public health emergencies.

PURPOSE: We utilized quality improvement (QI) approaches to increase emergency department (ED) provider engagement with research participant enrollment during the opioid crisis and coronavirus disease (COVID-19) pandemic. The context of this work is the Evaluating Microdosing in the Emergency Department (EMED) study, a randomized trial offering buprenorphine/naloxone to ED patients through randomization to standard or microdosing induction. Engaging providers is crucial for participant recruitment to our study. Anticipating challenges sustaining long-term engagement after a 63% decline in provider referrals four months into enrollments, we applied Plan-Do-Study-Act (PDSA) cycles to develop and implement an engagement strategy to increase and sustain provider engagement by 50% from baseline within 9 months. METHODS: Our engagement strategy was centered on Coffee Carts rounds: 5-min study-related educational presentations for providers on shift; and a secondary initiative, a Suboxone Champions program, to engage interested providers as study-related peer educators. We used provider referrals to our team as a proxy for study engagement and report the percent change in mean weekly referrals across two PDSA cycles relative to our established referral baseline. RESULTS: A QI approach afforded real-time review of interventions based on research and provider priorities, increasing engagement via mean weekly provider referrals by 14.5% and 49% across two PDSA cycles relative to baseline, respectively. CONCLUSIONS: Our Coffee Carts and Suboxone Champions program are efficient, low-barrier, educational initiatives to convey study-related information to providers. This work supported our efforts to maximally engage providers, minimize burden, and provide life-saving buprenorphine/naloxone to patients at risk of fatal overdose.

RéSUMé: BUT: Nous avons utilisé des approches d'amélioration de la qualité (AQ) pour accroître l'engagement des fournisseurs des services d'urgence (SU) avec l'inscription des participants à la recherche pendant la crise des opioïdes et la pandémie de maladie à coronavirus (COVID-19). Le contexte de ce travail est l'étude Evaluating Microdosing in the Emergency Department (EMED), un essai randomisé offrant de la buprénorphine/naloxone aux patients aux urgences par randomisation à l'induction standard ou au microdosage. L'engagement des fournisseurs est crucial pour le recrutement des participants à notre étude. En anticipant les difficultés à maintenir un engagement à long terme après une baisse de 63 % des recommandations de fournisseurs quatre mois après les inscriptions, nous avons appliqué le Plan-Do-Study-Act (PDSA) cycles d'élaboration et de mise en œuvre d'une stratégie d'engagement visant à accroître et à maintenir l'engagement des fournisseurs de 50 % par rapport au niveau de référence dans les neuf mois. MéTHODES: Notre stratégie de mobilisation était axée sur les tournées de Coffee Carts : des présentations éducatives de cinq minutes sur l'étude pour les fournisseurs sur le quart de travail; et une initiative secondaire, un programme Suboxone Champions, pour mobiliser les fournisseurs intéressés en tant que pairs éducateurs liés à l'étude. Nous avons utilisé les recommandations des fournisseurs à notre équipe comme indicateur de la participation à l'étude et nous avons signalé le pourcentage de changement dans les recommandations hebdomadaires moyennes pour deux cycles PDSA par rapport à notre base de référence établie. RéSULTATS: Une approche d'AQ a permis d'examiner en temps réel les interventions en fonction des priorités de la recherche et des fournisseurs, ce qui a augmenté l'engagement par l'intermédiaire des recommandations hebdomadaires moyennes des fournisseurs de 14,5 % et de 49 % au cours de deux cycles de PDSA par rapport au niveau de référence, respectivement. CONCLUSION: Notre programme Coffee Carts and Suboxone Champions est une initiative éducative efficace et peu contraignante qui permet de transmettre aux fournisseurs des renseignements sur les études. Ce travail a appuyé nos efforts visant à mobiliser au maximum les fournisseurs, à réduire au minimum le fardeau et à fournir de la buprénorphine/naloxone vitale aux patients à risque de surdose mortelle.

Environmental factors and host sex influence the skin microbiota structure of Hong Kong newt (Paramesotriton hongkongensis) in a coldspot of chytridiomycosis in subtropical East Asia.

Chytridiomycosis, an infectious skin disease caused by the chytrid fungi, Batrachochytrium dendrobatidis and B. salamandrivorans, poses a significant threat to amphibian biodiversity worldwide. Antifungal bacteria found on the skin of chytrid-resistant amphibians could potentially provide defense against chytridiomycosis and lower mortality rates among resistant individuals. The Hong Kong newt (Paramesotriton hongkongensis) is native to East Asia, a region suspected to be the origin of chytrids, and has exhibited asymptomatic infection, suggesting a long-term coexistence with the chytrids. Therefore, the skin microbiota of this resistant species warrant investigation, along with other factors that can affect the microbiota. Among the 149 newts sampled in their natural habitats in Hong Kong, China, putative antifungal bacteria were found in all individuals. There were 314 amplicon sequence variants distributed over 25 genera of putative antifungal bacteria; abundant ones included Acinetobacter, Flavobacterium, and Novosphingobium spp. The skin microbiota compositions were strongly influenced by the inter-site geographical distances. Despite inter-site differences, we identified some core skin microbes across sites that could be vital to P. hongkongensis. The dominant cores included the family Comamonadaceae, family Chitinophagaceae, and class Betaproteobacteria. Moreover, habitat elevation and host sex also exhibited significant effects on skin microbiota compositions. The antifungal bacteria found on these newts offer an important resource for conservation against chytridiomycosis, such as developing probiotic treatments for susceptible species.

Osterix-driven LINC complex disruption in vivo diminishes osteogenesis at 8 weeks but not at 15 weeks.

The Linker of Nucleoskeleton and Cytoskeleton (LINC) complex is a crucial connective component between the nuclear envelope and the cytoskeleton involving various cellular processes including nuclear positioning, nuclear architecture, and mechanotransduction. How LINC complexes regulate bone formation in vivo, however, is not well understood. To start bridging this gap, here we created a LINC disruption murine model using transgenic mice expressing Cre recombinase enzyme under the control of the Osterix (Osx-Cre) which is primarily active in pre-osteoblasts and floxed Tg(CAG-LacZ/EGFP-KASH2) mice. Tg(CAG-LacZ/EGFP-KASH2) mice contain a lox-STOP-lox flanked LacZ gene which is deleted upon cre recombination allowing for the overexpression of an EGFP-KASH2 fusion protein. This overexpressed protein disrupts endogenous Nesprin-Sun binding leading to disruption of LINC complexes. Thus, crossing these two lines results in an  Osx- driven  LINC  disruption (ODLD) specific to pre-osteoblasts. In this study, we investigated how this LINC disruption affects exercise-induced bone accrual. ODLD cells had decreased osteogenic and adipogenic potential in vitro compared to non-disrupted controls and sedentary ODLD mice showed decreased bone quality at 8 weeks. Upon access to a voluntary running wheel, ODLD animals showed increased running time and distance; however, our 6-week exercise intervention did not significantly affect bone microarchitecture and bone mechanical properties.