Structural Basis for Gating and Activation of RyR1.

The type-1 ryanodine receptor (RyR1) is an intracellular calcium (Ca(2+)) release channel required for skeletal muscle contraction. Here, we present cryo-EM reconstructions of RyR1 in multiple functional states revealing the structural basis of channel gating and ligand-dependent activation. Binding sites for the channel activators Ca(2+), ATP, and caffeine were identified at interdomain interfaces of the C-terminal domain. Either ATP or Ca(2+) alone induces conformational changes in the cytoplasmic assembly ("priming"), without pore dilation. In contrast, in the presence of all three activating ligands, high-resolution reconstructions of open and closed states of RyR1 were obtained from the same sample, enabling analyses of conformational changes associated with gating. Gating involves global conformational changes in the cytosolic assembly accompanied by local changes in the transmembrane domain, which include bending of the S6 transmembrane segment and consequent pore dilation, displacement, and deformation of the S4-S5 linker and conformational changes in the pseudo-voltage-sensor domain.

A thin mantle transition zone beneath the equatorial Mid-Atlantic Ridge.

The location and degree of material transfer between the upper and lower mantle are key to the Earth's thermal and chemical evolution. Sinking slabs and rising plumes are generally accepted as locations of transfer1,2, whereas mid-ocean ridges are not typically assumed to have a role3. However, tight constraints from in situ measurements at ridges have proved to be challenging. Here we use receiver functions that reveal the conversion of primary to secondary seismic waves to image the discontinuities that bound the mantle transition zone, using ocean bottom seismic data from the equatorial Mid-Atlantic Ridge. Our images show that the seismic discontinuity at depths of about 660 kilometres is broadly uplifted by 10 ± 4 kilometres over a swath about 600 kilometres wide and that the 410-kilometre discontinuity is depressed by 5 ± 4 kilometres. This thinning of the mantle transition zone is coincident with slow shear-wave velocities in the mantle, from global seismic tomography4-7. In addition, seismic velocities in the mantle transition zone beneath the Mid-Atlantic Ridge are on average slower than those beneath older Atlantic Ocean seafloor. The observations imply material transfer from the lower to the upper mantle-either continuous or punctuated-that is linked to the Mid-Atlantic Ridge. Given the length and longevity of the mid-ocean ridge system, this implies that whole-mantle convection may be more prevalent than previously thought, with ridge upwellings having a role in counterbalancing slab downwellings.

Stabilization of interdomain closure by a G protein inhibitor.

Inhibitors of heterotrimeric G proteins are being developed as therapeutic agents. Epitomizing this approach are YM-254890 (YM) and FR900359 (FR), which are efficacious in models of thrombosis, hypertension, obesity, asthma, uveal melanoma, and pain, and under investigation as an FR-antibody conjugate in uveal melanoma clinical trials. YM/FR inhibits the Gq/11/14 subfamily by interfering with GDP (guanosine diphosphate) release, but by an unknown biophysical mechanism. Here, we show that YM inhibits GDP release by stabilizing closure between the Ras-like and α-helical domains of a Gα subunit. Nucleotide-free Gα adopts an ensemble of open and closed configurations, as indicated by single-molecule Förster resonance energy transfer and molecular dynamics simulations, whereas GDP and GTPγS (guanosine 5'-O-[gamma-thio]triphosphate) stabilize distinct closed configurations. YM stabilizes closure in the presence or absence of GDP without requiring an intact interdomain interface. All three classes of mammalian Gα subunits that are insensitive to YM/FR possess homologous but degenerate YM/FR binding sites, yet can be inhibited upon transplantation of the YM/FR binding site of Gq. Novel YM/FR analogs tailored to each class of G protein will provide powerful new tools for therapeutic investigation.

MFSD12 mediates the import of cysteine into melanosomes and lysosomes.

Dozens of genes contribute to the wide variation in human pigmentation. Many of these genes encode proteins that localize to the melanosome-the organelle, related to the lysosome, that synthesizes pigment-but have unclear functions1,2. Here we describe MelanoIP, a method for rapidly isolating melanosomes and profiling their labile metabolite contents. We use this method to study MFSD12, a transmembrane protein of unknown molecular function that, when suppressed, causes darker pigmentation in mice and humans3,4. We find that MFSD12 is required to maintain normal levels of cystine-the oxidized dimer of cysteine-in melanosomes, and to produce cysteinyldopas, the precursors of pheomelanin synthesis made in melanosomes via cysteine oxidation5,6. Tracing and biochemical analyses show that MFSD12 is necessary for the import of cysteine into melanosomes and, in non-pigmented cells, lysosomes. Indeed, loss of MFSD12 reduced the accumulation of cystine in lysosomes of fibroblasts from patients with cystinosis, a lysosomal-storage disease caused by inactivation of the lysosomal cystine exporter cystinosin7-9. Thus, MFSD12 is an essential component of the cysteine importer for melanosomes and lysosomes.

Protein Kinase Signaling Networks Driven by Oncogenic Gq/11 in Uveal Melanoma Identified by Phosphoproteomic and Bioinformatic Analyses.

Metastatic uveal melanoma (UM) patients typically survive only 2 to 3 years because effective therapy does not yet exist. Here, to facilitate the discovery of therapeutic targets in UM, we have identified protein kinase signaling mechanisms elicited by the drivers in 90% of UM tumors: mutant constitutively active G protein α-subunits encoded by GNAQ (Gq) or GNA11 (G11). We used the highly specific Gq/11 inhibitor FR900359 (FR) to elucidate signaling networks that drive proliferation, metabolic reprogramming, and dedifferentiation of UM cells. We determined the effects of FR on the proteome and phosphoproteome of UM cells as indicated by bioinformatic analyses with CausalPath and site-specific gene set enrichment analysis. We found that inhibition of oncogenic Gq/11 caused deactivation of PKC, Erk, and the cyclin-dependent kinases CDK1 and CDK2 that drive proliferation. Inhibition of oncogenic Gq/11 in UM cells with low metastatic risk relieved inhibitory phosphorylation of polycomb-repressive complex subunits that regulate melanocytic redifferentiation. Site-specific gene set enrichment analysis, unsupervised analysis, and functional studies indicated that mTORC1 and 6-phosphofructo-2-kinase/fructose-2,6-biphosphatase 2 drive metabolic reprogramming in UM cells. Together, these results identified protein kinase signaling networks driven by oncogenic Gq/11 that regulate critical aspects of UM cell biology and provide targets for therapeutic investigation.

Historical Redlining and Present-Day Nonsuicide Firearm Fatalities.

BACKGROUND: Redlining began in the 1930s with the Home Owners' Loan Corporation (HOLC); this discriminatory practice limited mortgage availability and reinforced concentrated poverty that still exists today. It is important to understand the potential health implications of this federally sanctioned segregation. OBJECTIVE: To examine the relationship between historical redlining policies and present-day nonsuicide firearm fatalities. DESIGN: Maps from the HOLC were overlaid with incidence of nonsuicide firearm fatalities from 2014 to 2022. A multilevel negative binomial regression model tested the association between modern-day firearm fatalities and HOLC historical grading (A ["best"] to D ["hazardous"]), controlling for year, HOLC area-level demographics, and state-level factors as fixed effects and a random intercept for city. Incidence rates (IRs) per 100 000 persons, incidence rate ratios (IRRs), and adjusted IRRs (aIRRs) for each HOLC grade were estimated using A-rated areas as the reference. SETTING: 202 cities with areas graded by the HOLC in the 1930s. PARTICIPANTS: Population of the 8597 areas assessed by the HOLC. MEASUREMENTS: Nonsuicide firearm fatalities. RESULTS: From 2014 to 2022, a total of 41 428 nonsuicide firearm fatalities occurred in HOLC-graded areas. The firearm fatality rate increased as the HOLC grade progressed from A to D. In A-graded areas, the IR was 3.78 (95% CI, 3.52 to 4.05) per 100 000 persons per year. In B-graded areas, the IR, IRR, and aIRR relative to A areas were 7.43 (CI, 7.24 to 7.62) per 100 000 persons per year, 2.12 (CI, 1.94 to 2.32), and 1.42 (CI, 1.30 to 1.54), respectively. In C-graded areas, these values were 11.24 (CI, 11.08 to 11.40) per 100 000 persons per year, 3.78 (CI, 3.47 to 4.12), and 1.90 (CI, 1.75 to 2.07), respectively. In D-graded areas, these values were 16.26 (CI, 16.01 to 16.52) per 100 000 persons per year, 5.51 (CI, 5.05 to 6.02), and 2.07 (CI, 1.90 to 2.25), respectively. LIMITATION: The Gun Violence Archive relies on media coverage and police reports. CONCLUSION: Discriminatory redlining policies from 80 years ago are associated with nonsuicide firearm fatalities today. PRIMARY FUNDING SOURCE: Fred Lovejoy Housestaff Research and Education Fund.

Influence of Antibiotic Exposure Intensity on the Risk of Clostridioides difficile Infection.

BACKGROUND: Antibiotics are a strong risk factor for Clostridioides difficile infection (CDI), and CDI incidence is often measured as an important outcome metric for antimicrobial stewardship interventions aiming to reduce antibiotic use. However, risk of CDI from antibiotics varies by agent and dependent on the intensity (i.e., spectrum and duration) of antibiotic therapy. Thus, the impact of stewardship interventions on CDI incidence is variable, and understanding this risk requires a more granular measure of intensity of therapy than traditionally used measures like days of therapy (DOT). METHODS: We performed a retrospective cohort study to measure the independent association between intensity of antibiotic therapy, as measured by the antibiotic spectrum index (ASI), and hospital-associated CDI (HA-CDI) at a large academic medical center between January 2018 and March 2020. We constructed a marginal Poisson regression model to generate adjusted relative risks for a unit increase in ASI per antibiotic day. RESULTS: We included 35,457 inpatient encounters in our cohort. Sixty-eight percent of patients received at least one antibiotic. We identified 128 HA-CDI cases, which corresponds to an incidence rate of 4.1 cases per 10,000 patient-days. After adjusting for known confounders, each additional unit increase in ASI per antibiotic day is associated with 1.09 times the risk of HA-CDI (Relative Risk = 1.09, 95% Confidence Interval: 1.06 to 1.13). CONCLUSIONS: ASI was strongly associated with HA-CDI and could be a useful tool in evaluating the impact of antibiotic stewardship on HA-CDI rates, providing more granular information than the more commonly used days of therapy.

Targeting cancer-associated fibroblasts in the bone marrow prevents resistance to CART-cell therapy in multiple myeloma.

Pivotal clinical trials of B-cell maturation antigen-targeted chimeric antigen receptor T (CART)-cell therapy in patients with relapsed/refractory multiple myeloma (MM) resulted in remarkable initial responses, which led to a recent US Food and Drug Administration approval. Despite the success of this therapy, durable remissions continue to be low, and the predominant mechanism of resistance is loss of CART cells and inhibition by the tumor microenvironment (TME). MM is characterized by an immunosuppressive TME with an abundance of cancer-associated fibroblasts (CAFs). Using MM models, we studied the impact of CAFs on CART-cell efficacy and developed strategies to overcome CART-cell inhibition. We showed that CAFs inhibit CART-cell antitumor activity and promote MM progression. CAFs express molecules such as fibroblast activation protein and signaling lymphocyte activation molecule family-7, which are attractive immunotherapy targets. To overcome CAF-induced CART-cell inhibition, CART cells were generated targeting both MM cells and CAFs. This dual-targeting CART-cell strategy significantly improved the effector functions of CART cells. We show for the first time that dual targeting of both malignant plasma cells and the CAFs within the TME is a novel strategy to overcome resistance to CART-cell therapy in MM.

Architecture of the human GATOR1 and GATOR1-Rag GTPases complexes.

Nutrients, such as amino acids and glucose, signal through the Rag GTPases to activate mTORC1. The GATOR1 protein complex-comprising DEPDC5, NPRL2 and NPRL3-regulates the Rag GTPases as a GTPase-activating protein (GAP) for RAGA; loss of GATOR1 desensitizes mTORC1 signalling to nutrient starvation. GATOR1 components have no sequence homology to other proteins, so the function of GATOR1 at the molecular level is currently unknown. Here we used cryo-electron microscopy to solve structures of GATOR1 and GATOR1-Rag GTPases complexes. GATOR1 adopts an extended architecture with a cavity in the middle; NPRL2 links DEPDC5 and NPRL3, and DEPDC5 contacts the Rag GTPase heterodimer. Biochemical analyses reveal that our GATOR1-Rag GTPases structure is inhibitory, and that at least two binding modes must exist between the Rag GTPases and GATOR1. Direct interaction of DEPDC5 with RAGA inhibits GATOR1-mediated stimulation of GTP hydrolysis by RAGA, whereas weaker interactions between the NPRL2-NPRL3 heterodimer and RAGA execute GAP activity. These data reveal the structure of a component of the nutrient-sensing mTORC1 pathway and a non-canonical interaction between a GAP and its substrate GTPase.

Safety and Efficacy Report for the Use of Poly-4-Hydroxybutyrate as a Retropubic Mid-Urethral Sling (MUS) for Stress Urinary Incontinence: A Prospective 24 Months Follow-Up of New Poly-4-Hydroxybutyrate TephaFlex SUI Bioresorbable MUS.

STUDY OBJECTIVE: To investigate the feasibility and safety of the retropubic mid-urethral sling (MUS) procedure with a resorbable mesh implant made of poly-4-hydroxybutyrate (P4HB). DESIGN: A prospective clinical cohort study with 24 months follow-up. SETTING: A tertiary academic hospital. PATIENTS: Seventeen women with moderate to severe stress urinary incontinence (SUI). INTERVENTIONS: A retropubic MUS procedure with P4HB sling. MEASUREMENTS AND MAIN RESULTS: Seventeen women underwent an uncomplicated MUS procedure with a new sling made of resorbable P4HB. Following safety criteria, there has been no need to stop the study before 24 months' end point. Three serious adverse events were reported during follow-up: (1) inability to void urine after 1 week postsurgery, (2) a hysterectomy and bilateral oophorectomy performed due to a precancerous endometrial lesion at 16 months after initial MUS procedure and (3) exposed mesh with a part of device sheath left behind. These participants underwent an uncomplicated reintervention with no additional and/or permanent harm. Reinterventions because of failure of cure contained 3 second MUS procedures and one admission of urethral bulking agent. Seventy-six percent and 47 percent of patients were objectively cured of SUI at 12 and 24 months, respectively. CONCLUSIONS: Preliminary evidence suggests that a sling made of P4HB can be safely used for MUS procedures and could be an alternative for permanent polypropylene slings in patients that prefer the use of nonpermanent material.

Genome-wide CRISPR screens reveal multitiered mechanisms through which mTORC1 senses mitochondrial dysfunction.

In mammalian cells, nutrients and growth factors signal through an array of upstream proteins to regulate the mTORC1 growth control pathway. Because the full complement of these proteins has not been systematically identified, we developed a FACS-based CRISPR-Cas9 genetic screening strategy to pinpoint genes that regulate mTORC1 activity. Along with almost all known positive components of the mTORC1 pathway, we identified many genes that impact mTORC1 activity, including DCAF7, CSNK2B, SRSF2, IRS4, CCDC43, and HSD17B10 Using the genome-wide screening data, we generated a focused sublibrary containing single guide RNAs (sgRNAs) targeting hundreds of genes and carried out epistasis screens in cells lacking nutrient- and stress-responsive mTORC1 modulators, including GATOR1, AMPK, GCN2, and ATF4. From these data, we pinpointed mitochondrial function as a particularly important input into mTORC1 signaling. While it is well appreciated that mitochondria signal to mTORC1, the mechanisms are not completely clear. We find that the kinases AMPK and HRI signal, with varying kinetics, mitochondrial distress to mTORC1, and that HRI acts through the ATF4-dependent up-regulation of both Sestrin2 and Redd1. Loss of both AMPK and HRI is sufficient to render mTORC1 signaling largely resistant to mitochondrial dysfunction induced by the ATP synthase inhibitor oligomycin as well as the electron transport chain inhibitors piericidin and antimycin. Taken together, our data reveal a catalog of genes that impact the mTORC1 pathway and clarify the multifaceted ways in which mTORC1 senses mitochondrial dysfunction.

Oncogenic Gq/11 signaling acutely drives and chronically sustains metabolic reprogramming in uveal melanoma.

Metabolic reprogramming has been shown to occur in uveal melanoma (UM), the most common intraocular tumor in adults. Mechanisms driving metabolic reprogramming in UM are poorly understood. Elucidation of these mechanisms could inform development of new therapeutic strategies for metastatic UM, which has poor prognosis because existing therapies are ineffective. Here, we determined whether metabolic reprogramming is driven by constitutively active mutant α-subunits of the heterotrimeric G proteins Gq or G11 (Gq/11), the oncogenic drivers in ∼90% of UM patients. Using PET-computed tomography imaging, microphysiometry, and GC/MS, we found that inhibition of oncogenic Gq/11 with the small molecule FR900359 (FR) attenuated glucose uptake by UM cells in vivo and in vitro, blunted glycolysis and mitochondrial respiration in UM cell lines and tumor cells isolated from patients, and reduced levels of several glycolytic and tricarboxylic acid cycle intermediates. FR acutely inhibited glycolysis and respiration and chronically attenuated expression of genes in both metabolic processes. UM therefore differs from other melanomas that exhibit a classic Warburg effect. Metabolic reprogramming in UM cell lines and patient samples involved protein kinase C and extracellular signal-regulated protein kinase 1/2 signaling downstream of oncogenic Gq/11. Chronic administration of FR upregulated expression of genes involved in metabolite scavenging and redox homeostasis, potentially as an adaptive mechanism explaining why FR does not efficiently kill UM tumor cells or regress UM tumor xenografts. These results establish that oncogenic Gq/11 signaling is a crucial driver of metabolic reprogramming in UM and lay a foundation for studies aimed at targeting metabolic reprogramming for therapeutic development.

Disruption of the nectin-afadin complex recapitulates features of the human cleft lip/palate syndrome CLPED1.

Cleft palate (CP), one of the most common congenital conditions, arises from failures in secondary palatogenesis during embryonic development. Several human genetic syndromes featuring CP and ectodermal dysplasia have been linked to mutations in genes regulating cell-cell adhesion, yet mouse models have largely failed to recapitulate these findings. Here, we use in utero lentiviral-mediated genetic approaches in mice to provide the first direct evidence that the nectin-afadin axis is essential for proper palate shelf elevation and fusion. Using this technique, we demonstrate that palatal epithelial conditional loss of afadin (Afdn) - an obligate nectin- and actin-binding protein - induces a high penetrance of CP, not observed when Afdn is targeted later using Krt14-Cre We implicate Nectin1 and Nectin4 as being crucially involved, as loss of either induces a low penetrance of mild palate closure defects, while loss of both causes severe CP with a frequency similar to Afdn loss. Finally, expression of the human disease mutant NECTIN1W185X causes CP with greater penetrance than Nectin1 loss, suggesting this alteration may drive CP via a dominant interfering mechanism.

Prehospital Transport Time and Outcomes for Pediatric Trauma: A National Study.

INTRODUCTION: Historically, emergency medical services have aimed to deliver trauma patients to definitive care within the 60 min (min) "Golden Hour" to optimize survival. There is little evidence to support or refute this for pediatric trauma. The objective of this investigation was to describe national trends in prehospital transport time, in relation to the "Golden Hour," and pediatric trauma outcomes. METHODS: Retrospective cohort study of patients (<15 y old) receiving emergency medical services trauma transport between 2017 and 2019. Transport time (less than or greater than 60 min) was the exposure variable, and analyses were adjusted for injury severity score (ISS). Continuous variables with a normal distribution were compared by t-test was and skewed variables were compared by Mann-Whitney U-test. Categorical variables were compared by Chi-Square test. RESULTS: 54,489 patients met our criteria: 49,628 blunt and 4861 penetrating. Most patients (62.2%) had transport times less than 60 min: 30,389 (61.2%) blunt and 3479 (71.6%) penetrating. The overall mortality rate was 1.6%, 1.2% for blunt and 5.5% for penetrating. For blunt trauma, mortality was higher for transport times less than 60 min (1.5%). For penetrating trauma, mortality was lower for transport times less than 60 min (0.7%). Mean ISS was greater for blunt (7.9) compared to penetrating trauma (7.1), and greater for both trauma types with transport times less than 60 min. For both trauma types, mean length of stay was significantly longer for transport times greater than 60 min, when adjusting for ISS (P < 0.001). CONCLUSIONS: We did not find evidence that prehospital transport within the "Golden Hour" had a substantial association with survival, though it may be associated with length of stay. There are many factors contributing to trauma outcomes, so efforts should continue to expand access and pediatric readiness.

Dynamic pressure-volume loop analysis by simultaneous real-time cardiovascular magnetic resonance and left heart catheterization.

BACKGROUND: Left ventricular (LV) contractility and compliance are derived from pressure-volume (PV) loops during dynamic preload reduction, but reliable simultaneous measurements of pressure and volume are challenging with current technologies. We have developed a method to quantify contractility and compliance from PV loops during a dynamic preload reduction using simultaneous measurements of volume from real-time cardiovascular magnetic resonance (CMR) and invasive LV pressures with CMR-specific signal conditioning. METHODS: Dynamic PV loops were derived in 16 swine (n = 7 naïve, n = 6 with aortic banding to increase afterload, n = 3 with ischemic cardiomyopathy) while occluding the inferior vena cava (IVC). Occlusion was performed simultaneously with the acquisition of dynamic LV volume from long-axis real-time CMR at 0.55 T, and recordings of invasive LV and aortic pressures, electrocardiogram, and CMR gradient waveforms. PV loops were derived by synchronizing pressure and volume measurements. Linear regression of end-systolic- and end-diastolic- pressure-volume relationships enabled calculation of contractility. PV loops measurements in the CMR environment were compared to conductance PV loop catheter measurements in 5 animals. Long-axis 2D LV volumes were validated with short-axis-stack images. RESULTS: Simultaneous PV acquisition during IVC-occlusion was feasible. The cardiomyopathy model measured lower contractility (0.2 ± 0.1 mmHg/ml vs 0.6 ± 0.2 mmHg/ml) and increased compliance (12.0 ± 2.1 ml/mmHg vs 4.9 ± 1.1 ml/mmHg) compared to naïve animals. The pressure gradient across the aortic band was not clinically significant (10 ± 6 mmHg). Correspondingly, no differences were found between the naïve and banded pigs. Long-axis and short-axis LV volumes agreed well (difference 8.2 ± 14.5 ml at end-diastole, -2.8 ± 6.5 ml at end-systole). Agreement in contractility and compliance derived from conductance PV loop catheters and in the CMR environment was modest (intraclass correlation coefficient 0.56 and 0.44, respectively). CONCLUSIONS: Dynamic PV loops during a real-time CMR-guided preload reduction can be used to derive quantitative metrics of contractility and compliance, and provided more reliable volumetric measurements than conductance PV loop catheters.

Characterizing Unhealthy Alcohol Use Patterns and Their Association with Alcohol Use Reduction and Alcohol Use Disorder During Follow-Up in HIV Care.

Outcomes of PWH with unhealthy alcohol use, such as alcohol use reduction or progression to AUD, are not well-known and may differ by baseline patterns of unhealthy alcohol use. Among 1299 PWH screening positive for NIAAA-defined unhealthy alcohol use in Kaiser Permanente Northern California, 2013-2017, we compared 2-year probabilities of reduction to low-risk/no alcohol use and rates of new AUD diagnoses by baseline use patterns, categorized as exceeding: only daily limits (72% of included PWH), only weekly limits (17%), or both (11%), based on NIAAA recommendations. Overall, 73.2% (95% CI 70.5-75.9%) of re-screened PWH reduced to low-risk/no alcohol use over 2 years, and there were 3.1 (95% CI 2.5-3.8%) new AUD diagnoses per 100 person-years. Compared with PWH only exceeding daily limits at baseline, those only exceeding weekly limits and those exceeding both limits were less likely to reduce and likelier to be diagnosed with AUD during follow-up. PWH exceeding weekly drinking limits, with or without exceeding daily limits, may have a potential need for targeted interventions to address unhealthy alcohol use.

Racial and Ethnic Disparities in Access to Pediatric Trauma Centers in the United States: A Geographic Information Systems Analysis.

STUDY OBJECTIVE: Injury is the leading cause of death and disability for children, making access to pediatric trauma centers crucial to pediatric trauma care. Our objective was to describe the pediatric population with timely access to a pediatric trauma center by demographics and geography in the United States. METHODS: Level 1, 2, and 3 pediatric trauma center locations were provided by the American Trauma Society. Geographic information systems road network and rotor wing analysis determined US Census Block Groups with the ground and/or air access to a pediatric trauma center within a 60-minute transport time. We then described, at the national and state levels, the 2020 pediatric population (< 15 years old) with and without pediatric trauma center access by ground and air, stratified by race, ethnicity, and urbanicity. RESULTS: There were 157 pediatric trauma centers (82 Level 1, 64 Level 2, 11 Level 3). Of the 2020 US pediatric population, 33,352,872 (54.5%) had timely access to Level 1-3 pediatric trauma centers by ground and 45,431,026 (74.1%) by air. The percentage of children with access by race and ethnicity were (by ground, by air): American Indian/Alaskan Native (31.0%, 43.5%), White (48.7%, 71.3%), Native Hawaiian/Pacific Islander (59.3%, 61.0%), Hispanic (60.2%, 76.9%), Black (64.2%, 78.0%), and Asian (76.5%, 89.5%). Only 48.2% of children living in rural block groups had access, compared with 83.6% in urban block groups. CONCLUSION: Significant disparities in current access to pediatric trauma centers exist by race and ethnicity, and geography, leaving some children at risk for poor trauma outcomes.

Auditory roughness: a delicate balance.

Auditory roughness in medical alarm sounds is an important design attribute, and has been shown to impact user performance and perception. While roughness can assist in decreased signal-to-noise ratios (perceived loudness) and communicate urgency, it might also impact patient recovery. Therefore, considerations of neuroscience correlates, music theory, and patient impact are critical aspects to investigate in order to optimise alarm design.

KICSTOR recruits GATOR1 to the lysosome and is necessary for nutrients to regulate mTORC1.

The mechanistic target of rapamycin complex 1 (mTORC1) is a central regulator of cell growth that responds to diverse environmental signals and is deregulated in many human diseases, including cancer and epilepsy. Amino acids are a key input to this system, and act through the Rag GTPases to promote the translocation of mTORC1 to the lysosomal surface, its site of activation. Multiple protein complexes regulate the Rag GTPases in response to amino acids, including GATOR1, a GTPase activating protein for RAGA, and GATOR2, a positive regulator of unknown molecular function. Here we identify a protein complex (KICSTOR) that is composed of four proteins, KPTN, ITFG2, C12orf66 and SZT2, and that is required for amino acid or glucose deprivation to inhibit mTORC1 in cultured human cells. In mice that lack SZT2, mTORC1 signalling is increased in several tissues, including in neurons in the brain. KICSTOR localizes to lysosomes; binds and recruits GATOR1, but not GATOR2, to the lysosomal surface; and is necessary for the interaction of GATOR1 with its substrates, the Rag GTPases, and with GATOR2. Notably, several KICSTOR components are mutated in neurological diseases associated with mutations that lead to hyperactive mTORC1 signalling. Thus, KICSTOR is a lysosome-associated negative regulator of mTORC1 signalling, which, like GATOR1, is mutated in human disease.

A Building Block Approach for the Total Synthesis of YM-385781.

YM-254890 and FR900359 are potent and selective inhibitors of the Gq/11-signaling pathway. As such, they have been attractive targets for both synthesis and biological studies. Yet in spite of this effort, a versatile synthetic approach to the molecules that allows for the rapid construction of a variety of non-natural and labelled analogs and an increase in the amount of those analogs available remains elusive. We report here a convergent building block approach to the molecules that can solve this challenge.