A novel, reverse-phase-shifting, thermoreversible foaming hydrogel containing antibiotics for the treatment of thermal burns in a swine model - A pilot study.

BACKGROUND: This study compared a novel topical hydrogel burn dressing (CI-PRJ012) to standard of care (silver sulfadiazine) and to untreated control in a swine thermal burn model, to assess for wound healing properties both in the presence and absence of concomitant bacterial inoculation. METHODS: Eight equal burn wounds were created on six Yorkshire swine. Half the wounds were randomized to post-burn bacterial inoculation. Wounds were subsequently randomized to three treatments groups: no intervention, CI-PRJ012, or silver sulfadiazine cream. At study end, a blinded pathologist evaluated wounds for necrosis and bacterial colonization. RESULTS: When comparing CI-PRJ012 and silver sulfadiazine cream to no treatment, both agents significantly reduced the amount of necrosis and bacteria at 7 days after wound creation (p < 0.01, independently for both). Further, CI-PRJ012 was found to be significantly better than silver sulfadiazine (p < 0.02) in reducing bacterial colonization. For wound necrosis, no significant difference was found between silver sulfadiazine cream and CI-PRJ012 (p = 0.33). CONCLUSIONS: CI-PRJ012 decreases necrosis and bacterial colonization compared to no treatment in a swine model. CI-PRJ012 appeared to perform comparably to silver sulfadiazine. CI-PRJ012, which is easily removed with the application of room-temperature water, may provide clinical advantages over silver sulfadiazine.

The second molar dilemma in orthodontics: to bond or not to bond?

OBJECTIVES: To compare orthodontic treatment (OT) outcome in adolescents undergoing nonextraction fixed OT with or without bonding of second molars using the score of the American Board of Orthodontics Cast Radiograph Evaluation (C-R-Eval). MATERIALS AND METHODS: This study included healthy adolescents with skeletal Class I or mild Class II/Class III malocclusion, normal or deep overbite (OB), and mild-to-moderate dental crowding (<5 mm) who underwent nonextraction fixed OT with ("bonded" group) or without ("not-bonded" group) bonding of second molars. Patient treatment records, pre- and posttreatment digital models, lateral cephalograms, and orthopantomograms were assessed. The evaluated outcomes included leveling of the curve of Spee (COS), OB, control of incisor mandibular plane angle (IMPA), number of emergency visits (related to poking wires and/or bracket failure of the terminal molar tubes), treatment duration, and C-R-Eval. Treatment variables were compared across time points and among groups. RESULTS: The sample included 30 patients (mean age 16.07 ± 1.80 years) in the bonded group and 32 patients (mean age 15.69 ± 1.86 years) in the not-bonded group. The mean overall C-R-Eval score was significantly higher (P < .001) in the not-bonded group (25.25 ± 3.98) than in the bonded group (17.70 ± 2.97). There were no significant differences in mean changes of COS, OB, IMPA, or treatment duration among groups. The mean number of emergency visits was significantly higher in the bonded (3.3 ± 0.6) than the not-bonded group (1.9 ± 0.4) (P < .001). CONCLUSIONS: Bonding of second molars enhances the outcome of nonextraction fixed OT as demonstrated by the C-R-Eval without increasing treatment duration, irrespective of more emergency visits.

Influence of psychostimulants on bone mineral density and content among children with attention deficit hyperactivity disorder. A systematic review.

There is a controversy over the influence of psychostimulant medications on bone mineral density (BMD) and bone mineral content (BMC) among children with attention-deficit-hyperactivity-disorder (ADHD). The aim of the present systematic review was to assess the influence of psychostimulant medications on BMD and BMC among children with ADHD. A comprehensive search of electronic databases, including PubMed, Scopus, Embase, and Cochrane Library, was conducted to identify relevant studies published up until July 2023. Clinical studies that addressed the focused question "Do psychostimulant medications affect bone mineral density and content in children with ADHD?" were included. Letters to the Editor, studies on animal-models, ex-vivo and in-vitro studies, commentaries and reviews were excluded. The primary outcome measures were changes in BMD and BMC. Study quality was assessed using the risk of bias for non-randomized studies-exposure tool. Five non-randomized clinical studies were included. The number of participants ranged from 18 to 6489 with mean ages ranging from 7.3 to 13.75 years. The study durations ranged between five and seven years. In all studies osseous evaluation was done using dual-energy X-ray absorptiometry. The bone locations examined included total body, lumbar-spine, femur, femoral-neck, femoral body, and pelvis. Two studies reported that psychostimulant medications reduce BMC and BMD. In one study, bone turnover, serum leptin and fat levels were reduced in children using psychostimulant medications but no unusual reduction recorded among controls. In general, 80 % of the studies concluded that psychostimulant medications compromise BMC and BMD. Power analysis was done in one study. One study had a low RoB and the remaining demonstrated some concerns. Given the methodological concerns observed in the included studies, arriving at a definitive conclusion regarding the effects of psychostimulant medications on BMC, BMD, and bone turnover in children with ADHD is challenging. However, it is important to acknowledge that an association between psychostimulant medications and these bone-related parameters cannot be disregarded.

How Do Drivers Perceive Risks During Automated Driving Scenarios? An fNIRS Neuroimaging Study.

OBJECTIVE: Using brain haemodynamic responses to measure perceived risk from traffic complexity during automated driving. BACKGROUND: Although well-established during manual driving, the effects of driver risk perception during automated driving remain unknown. The use of fNIRS in this paper for assessing drivers' states posits it could become a novel method for measuring risk perception. METHODS: Twenty-three volunteers participated in an empirical driving simulator experiment with automated driving capability. Driving conditions involved suburban and urban scenarios with varying levels of traffic complexity, culminating in an unexpected hazardous event. Perceived risk was measured via fNIRS within the prefrontal cortical haemoglobin oxygenation and from self-reports. RESULTS: Prefrontal cortical haemoglobin oxygenation levels significantly increased, following self-reported perceived risk and traffic complexity, particularly during the hazardous scenario. CONCLUSION: This paper has demonstrated that fNIRS is a valuable research tool for measuring variations in perceived risk from traffic complexity during highly automated driving. Even though the responsibility over the driving task is delegated to the automated system and dispositional trust is high, drivers perceive moderate risk when traffic complexity builds up gradually, reflected in a corresponding significant increase in blood oxygenation levels, with both subjective (self-reports) and objective (fNIRS) increasing further during the hazardous scenario. APPLICATION: Little is known regarding the effects of drivers' risk perception with automated driving. Building upon our experimental findings, future work can use fNIRS to investigate the mental processes for risk assessment and the effects of perceived risk on driving behaviours to promote the safe adoption of automated driving technology.

Physicochemical stability of PF-05280014 (trastuzumab-qyyp; TrazimeraTM), a trastuzumab biosimilar, under extended in-use conditions.

INTRODUCTION: The stability and functional activity of the trastuzumab biosimilar PF-05280014 (trastuzumab-qyyp; TrazimeraTM), was assessed under extended in-use conditions. METHODS: PF-05280014 was diluted in 0.9% sodium chloride to final concentrations of 0.2 mg/mL and 4 mg/mL in 3 different types of infusion bags (polyolefin, ethylene vinyl acetate, and polyvinyl chloride). Infusion bags containing diluted PF-05280014 were stored at 25 ± 5° C for 24 h, before storage at 5 ± 3° C for 0, 1, 2, 4, or 6 weeks. Following extended storage, samples of PF-05280014 were removed from the infusion bags and stored at 25 ± 5° C for 24 h before biophysical and functional characterization. In addition to the visual characteristics of each sample at the various time points, the stability of PF-05280014 was assessed using a variety of biophysical techniques, including size-exclusion high-performance liquid chromatography, non-reducing sodium dodecyl sulfate capillary electrophoresis, cation-exchange chromatography, peptide mapping, far-UV circular dichroism spectroscopy, and differential scanning calorimetry. The functional activity of PF-05280014 was evaluated using a cell-based growth inhibition assay. RESULTS: For all PF-05280014 concentrations, time points and infusion bags tested, there were no significant differences in visual characteristics or in protein concentration. The were no significant changes in the relative abundance of molecular weight or charge variants throughout the 6-week study period. Similarly, there were no significant changes in primary structure or in secondary structure content during the study. The relative potency of PF-05280014 was also maintained throughout the 6-week period. CONCLUSIONS: The stability and functional activity of PF-05280014 was maintained following dilution in 0.9% sodium chloride and storage for up to 6 weeks at 2-8° C.

The urocortin peptides: biological relevance and laboratory aspects of UCN3 and its receptor.

The urocortins are polypeptides belonging to the corticotropin-releasing hormone family, known to modulate stress responses in mammals. Stress, whether induced physically or psychologically, is an underlying cause or consequence of numerous clinical syndromes. Identifying biological markers associated with the homeostatic regulation of stress could provide a clinical laboratory approach for the management of stress-related disorders. The neuropeptide, urocortin 3 (UCN3), and the corticotropin-releasing hormone receptor 2 (CRHR2) constitute a regulatory axis known to mediate stress homeostasis. Dysregulation of this peptide/receptor axis is believed to play a role in several clinical conditions including post-traumatic stress, sleep apnea, cardiovascular disease, and other health problems related to stress. Understanding the physiology and measurement of the UCN3/CRHR2 axis is important for establishing a viable clinical laboratory diagnostic. In this article, we focus on evidence supporting the role of UCN3 and its receptor in stress-related clinical syndromes. We also provide insight into the measurements of UCN3 in blood and urine. These potential biomarkers provide new opportunities for clinical research and applications of laboratory medicine diagnostics in stress management.

Discovery of VNRX-7145 (VNRX-5236 Etzadroxil): An Orally Bioavailable ß-Lactamase Inhibitor for Enterobacterales Expressing Ambler Class A, C, and D Enzymes.

A major antimicrobial resistance mechanism in Gram-negative bacteria is the production of ß-lactamase enzymes. The increasing emergence of ß-lactamase-producing multi-drug-resistant "superbugs" has resulted in increases in costly hospital Emergency Department (ED) visits and hospitalizations due to the requirement for parenteral antibiotic therapy for infections caused by these difficult-to-treat bacteria. To address the lack of outpatient treatment, we initiated an iterative program combining medicinal chemistry, biochemical testing, microbiological profiling, and evaluation of oral pharmacokinetics. Lead optimization focusing on multiple smaller, more lipophilic active compounds, followed by an exploration of oral bioavailability of a variety of their respective prodrugs, provided 36 (VNRX-7145/VNRX-5236 etzadroxil), the prodrug of the boronic acid-containing ß-lactamase inhibitor 5 (VNRX-5236). In vitro and in vivo studies demonstrated that 5 restored the activity of the oral cephalosporin antibiotic ceftibuten against Enterobacterales expressing Ambler class A extended-spectrum ß-lactamases, class A carbapenemases, class C cephalosporinases, and class D oxacillinases.

Microbiological Characterization of VNRX-5236, a Broad-Spectrum ß-Lactamase Inhibitor for Rescue of the Orally Bioavailable Cephalosporin Ceftibuten as a Carbapenem-Sparing Agent against Strains of Enterobacterales Expressing Extended-Spectrum ß-Lactamases and Serine Carbapenemases.

There is an urgent need for oral agents to combat resistant Gram-negative pathogens. Here, we describe the characterization of VNRX-5236, a broad-spectrum boronic acid ß-lactamase inhibitor (BLI), and its orally bioavailable etzadroxil prodrug, VNRX-7145. VNRX-7145 is being developed in combination with ceftibuten, an oral cephalosporin, to combat strains of Enterobacterales expressing extended-spectrum ß-lactamases (ESBLs) and serine carbapenemases. VNRX-5236 is a reversible covalent inhibitor of serine ß-lactamases, with inactivation efficiencies on the order of 104 M-1 · sec-1, and prolonged active site residence times (t1/2, 5 to 46 min). The spectrum of inhibition includes Ambler class A ESBLs, class C cephalosporinases, and class A and D carbapenemases (KPC and OXA-48, respectively). Rescue of ceftibuten by VNRX-5236 (fixed at 4 µg/ml) in isogenic strains of Escherichia coli expressing class A, C, or D ß-lactamases demonstrated an expanded spectrum of activity relative to oral comparators, including investigational penems, sulopenem, and tebipenem. VNRX-5236 rescued ceftibuten activity in clinical isolates of Enterobacterales expressing ESBLs (MIC90, 0.25 µg/ml), KPCs (MIC90, 1 µg/ml), class C cephalosporinases (MIC90, 1 µg/ml), and OXA-48-type carbapenemases (MIC90, 1 µg/ml). Frequency of resistance studies demonstrated a low propensity for recovery of resistant variants at 4× the MIC of the ceftibuten/VNRX-5236 combination. In vivo, whereas ceftibuten alone was ineffective (50% effective dose [ED50], >128 mg/kg), ceftibuten/VNRX-7145 administered orally protected mice from lethal septicemia caused by Klebsiella pneumoniae producing KPC carbapenemase (ED50, 12.9 mg/kg). The data demonstrate potent, broad-spectrum rescue of ceftibuten activity by VNRX-5236 in clinical isolates of cephalosporin-resistant and carbapenem-resistant Enterobacterales.

Curriculum Design and Scholarship for New Educators: A Professional Development Workshop for Medical Students.

Introduction: Medical students' professional development includes their role as educators. Despite greater opportunities to join medical education curriculum development, medical students' engagement in these activities remains limited. A recent national study on student leadership in curricular change revealed a formal lack of leadership and training in medical education as significant barriers. Medical students' unawareness of how to disseminate curricula as educational scholarship and its value to their careers also restricts the fullness of their formation as educators. Methods: We designed a 3-hour, interactive, project-focused conference workshop for medical students without prior knowledge in curriculum development. Of participants, 64 worked in 10 groups creating medical curricula using Kern's six-step approach in student-facilitated breakout sessions. Completed group projects were presented, including brief action plans for transforming their work into scholarship. The workshop was evaluated using a mixed-methods approach. Results: Of survey respondents, 44 mostly medical students, faculty, and administrators from different institutions rated the workshop as a very positive experience, and the pacing of the breakout groups as effective. A notable increase in self-reported mastery, as measured by learning objectives aligned with Kern's six-step model, was recorded from student respondents as compared to faculty. A sense of readiness to participate in curricular decisions either at the home institution or in individual career paths was evident from narrative comments. Discussion: Our workshop provided medical students with a foundation in curriculum development and educational scholarship. Session design provided flexibility in the pace of breakout sessions and allowed in-depth discussion of educational topics.

VISTA Re-programs Macrophage Biology Through the Combined Regulation of Tolerance and Anti-inflammatory Pathways.

We present the novel finding that V-domain Ig suppressor of T cell activation (VISTA) negatively regulates innate inflammation through the transcriptional and epigenetic re-programming of macrophages. Representative of VISTA re-programming is the ability of VISTA agonistic antibodies to augment LPS tolerance and reduce septic shock lethality in mice. This anti-inflammatory effect of anti-VISTA was mimicked in vitro demonstrating that anti-VISTA treatment caused a significant reduction in LPS-induced IL-12p40, IL-6, CXCL2, and TNF; all hallmark pro-inflammatory mediators of endotoxin shock. Even under conditions that typically "break" LPS tolerance, VISTA agonists sustained a macrophage anti-inflammatory profile. Analysis of the proteomic and transcriptional changes imposed by anti-VISTA show that macrophage re-programming was mediated by a composite profile of mediators involved in both macrophage tolerance induction (IRG1, miR221, A20, IL-10) as well as transcription factors central to driving an anti-inflammatory profile (e.g., IRF5, IRF8, NFKB1). These findings underscore a novel and new activity of VISTA as a negative checkpoint regulator that induces both tolerance and anti-inflammatory programs in macrophages and controls the magnitude of innate inflammation in vivo.

A constricted opening in Kir channels does not impede potassium conduction.

The canonical mechanistic model explaining potassium channel gating is of a conformational change that alternately dilates and constricts a collar-like intracellular entrance to the pore. It is based on the premise that K+ ions maintain a complete hydration shell while passing between the transmembrane cavity and cytosol, which must be accommodated. To put the canonical model to the test, we locked the conformation of a Kir K+ channel to prevent widening of the narrow collar. Unexpectedly, conduction was unimpaired in the locked channels. In parallel, we employed all-atom molecular dynamics to simulate K+ ions moving along the conduction pathway between the lower cavity and cytosol. During simulations, the constriction did not significantly widen. Instead, transient loss of some water molecules facilitated K+ permeation through the collar. The low free energy barrier to partial dehydration in the absence of conformational change indicates Kir channels are not gated by the canonical mechanism.

TBK1 and IKKε Act Redundantly to Mediate STING-Induced NF-κB Responses in Myeloid Cells.

Stimulator of Interferon Genes (STING) is a critical component of host innate immune defense but can contribute to chronic autoimmune or autoinflammatory disease. Once activated, the cyclic guanosine monophosphate (GMP)-adenosine monophosphate (AMP) (cGAMP) synthase (cGAS)-STING pathway induces both type I interferon (IFN) expression and nuclear factor-κB (NF-κB)-mediated cytokine production. Currently, these two signaling arms are thought to be mediated by a single upstream kinase, TANK-binding kinase 1 (TBK1). Here, using genetic and pharmacological approaches, we show that TBK1 alone is dispensable for STING-induced NF-κB responses in human and mouse immune cells, as well as in vivo. We further demonstrate that TBK1 acts redundantly with IκB kinase ε (IKKε) to drive NF-κB upon STING activation. Interestingly, we show that activation of IFN regulatory factor 3 (IRF3) is highly dependent on TBK1 kinase activity, whereas NF-κB is significantly less sensitive to TBK1/IKKε kinase inhibition. Our work redefines signaling events downstream of cGAS-STING. Our findings further suggest that cGAS-STING will need to be targeted directly to effectively ameliorate the inflammation underpinning disorders associated with STING hyperactivity.

Jumpstarting Team Cohesion with Team Activity Debriefings.

Although peer evaluations are essential to team-based learning, they can be problematic. Team activity debriefings (TAD) are advantageous because they focus on the team's problem-solving strategies and teamwork skills. Students (N = 100) who used both tools reported that TADs were more helpful in developing team cohesion, helping students understand the characteristics of well-functioning teams, and helping students work better as a team. Peer evaluations were more helpful in evaluating and improving their own contributions to the team. Using both tools may be the best way to foster teamwork skills and hold students accountable for making positive contributions to the team.

VISTA: A Target to Manage the Innate Cytokine Storm.

In recent years, the success of immunotherapy targeting immunoregulatory receptors (immune checkpoints) in cancer have generated enthusiastic support to target these receptors in a wide range of other immune related diseases. While the overwhelming focus has been on blockade of these inhibitory pathways to augment immunity, agonistic triggering via these receptors offers the promise of dampening pathogenic inflammatory responses. V-domain Ig suppressor of T cell activation (VISTA) has emerged as an immunoregulatory receptor with constitutive expression on both the T cell and myeloid compartments, and whose agonistic targeting has proven a unique avenue relative to other checkpoint pathways to suppress pathologies mediated by the innate arm of the immune system. VISTA agonistic targeting profoundly changes the phenotype of human monocytes towards an anti-inflammatory cell state, as highlighted by striking suppression of the canonical markers CD14 and Fcγr3a (CD16), and the almost complete suppression of both the interferon I (IFN-I) and antigen presentation pathways. The insights from these very recent studies highlight the impact of VISTA agonistic targeting of myeloid cells, and its potential therapeutic implications in the settings of hyperinflammatory responses such as cytokine storms, driven by dysregulated immune responses to viral infections (with a focus on COVID-19) and autoimmune diseases. Collectively, these findings suggest that the VISTA pathway plays a conserved, non-redundant role in myeloid cell function.

Discovery of Taniborbactam (VNRX-5133): A Broad-Spectrum Serine- and Metallo-ß-lactamase Inhibitor for Carbapenem-Resistant Bacterial Infections.

A major resistance mechanism in Gram-negative bacteria is the production of ß-lactamase enzymes. Originally recognized for their ability to hydrolyze penicillins, emergent ß-lactamases can now confer resistance to other ß-lactam drugs, including both cephalosporins and carbapenems. The emergence and global spread of ß-lactamase-producing multi-drug-resistant "superbugs" has caused increased alarm within the medical community due to the high mortality rate associated with these difficult-to-treat bacterial infections. To address this unmet medical need, we initiated an iterative program combining medicinal chemistry, structural biology, biochemical testing, and microbiological profiling to identify broad-spectrum inhibitors of both serine- and metallo-ß-lactamase enzymes. Lead optimization, beginning with narrower-spectrum, weakly active compounds, provided 20 (VNRX-5133, taniborbactam), a boronic-acid-containing pan-spectrum ß-lactamase inhibitor. In vitro and in vivo studies demonstrated that 20 restored the activity of ß-lactam antibiotics against carbapenem-resistant Pseudomonas aeruginosa and carbapenem-resistant Enterobacteriaceae. Taniborbactam is the first pan-spectrum ß-lactamase inhibitor to enter clinical development.

VNRX-5133 (Taniborbactam), a Broad-Spectrum Inhibitor of Serine- and Metallo-ß-Lactamases, Restores Activity of Cefepime in Enterobacterales and Pseudomonas aeruginosa.

As shifts in the epidemiology of ß-lactamase-mediated resistance continue, carbapenem-resistant Enterobacterales (CRE) and carbapenem-resistant Pseudomonas aeruginosa (CRPA) are the most urgent threats. Although approved ß-lactam (BL)-ß-lactamase inhibitor (BLI) combinations address widespread serine ß-lactamases (SBLs), such as CTX-M-15, none provide broad coverage against either clinically important serine-ß-lactamases (KPC, OXA-48) or clinically important metallo-ß-lactamases (MBLs; e.g., NDM-1). VNRX-5133 (taniborbactam) is a new cyclic boronate BLI that is in clinical development combined with cefepime for the treatment of infections caused by ß-lactamase-producing CRE and CRPA. Taniborbactam is the first BLI with direct inhibitory activity against Ambler class A, B, C, and D enzymes. From biochemical and structural analyses, taniborbactam exploits substrate mimicry while employing distinct mechanisms to inhibit both SBLs and MBLs. It is a reversible covalent inhibitor of SBLs with slow dissociation and a prolonged active-site residence time (half-life, 30 to 105 min), while in MBLs, it behaves as a competitive inhibitor, with inhibitor constant (Ki ) values ranging from 0.019 to 0.081 µM. Inhibition is achieved by mimicking the transition state structure and exploiting interactions with highly conserved active-site residues. In microbiological testing, taniborbactam restored cefepime activity in 33/34 engineered Escherichia coli strains overproducing individual enzymes covering Ambler classes A, B, C, and D, providing up to a 1,024-fold shift in the MIC. Addition of taniborbactam restored the antibacterial activity of cefepime against all 102 Enterobacterales clinical isolates tested and 38/41 P. aeruginosa clinical isolates tested with MIC90s of 1 and 4 µg/ml, respectively, representing ≥256- and ≥32-fold improvements, respectively, in antibacterial activity over that of cefepime alone. The data demonstrate the potent, broad-spectrum rescue of cefepime activity by taniborbactam against clinical isolates of CRE and CRPA.

HBO1 is required for the maintenance of leukaemia stem cells.

Acute myeloid leukaemia (AML) is a heterogeneous disease characterized by transcriptional dysregulation that results in a block in differentiation and increased malignant self-renewal. Various epigenetic therapies aimed at reversing these hallmarks of AML have progressed into clinical trials, but most show only modest efficacy owing to an inability to effectively eradicate leukaemia stem cells (LSCs)1. Here, to specifically identify novel dependencies in LSCs, we screened a bespoke library of small hairpin RNAs that target chromatin regulators in a unique ex vivo mouse model of LSCs. We identify the MYST acetyltransferase HBO1 (also known as KAT7 or MYST2) and several known members of the HBO1 protein complex as critical regulators of LSC maintenance. Using CRISPR domain screening and quantitative mass spectrometry, we identified the histone acetyltransferase domain of HBO1 as being essential in the acetylation of histone H3 at K14. H3 acetylated at K14 (H3K14ac) facilitates the processivity of RNA polymerase II to maintain the high expression of key genes (including Hoxa9 and Hoxa10) that help to sustain the functional properties of LSCs. To leverage this dependency therapeutically, we developed a highly potent small-molecule inhibitor of HBO1 and demonstrate its mode of activity as a competitive analogue of acetyl-CoA. Inhibition of HBO1 phenocopied our genetic data and showed efficacy in a broad range of human cell lines and primary AML cells from patients. These biological, structural and chemical insights into a therapeutic target in AML will enable the clinical translation of these findings.