In the inner ear, cochlear and vestibular sensory epithelia utilize grossly similar cell types to transduce different stimuli: sound and acceleration. Each individual sensory epithelium is composed ...of highly heterogeneous populations of cells based on physiological and anatomical criteria. However, limited numbers of each cell type have impeded transcriptional characterization. Here we generated transcriptomes for 301 single cells from the utricular and cochlear sensory epithelia of newborn mice to circumvent this challenge. Cluster analysis indicates distinct profiles for each of the major sensory epithelial cell types, as well as less-distinct sub-populations. Asynchrony within utricles allows reconstruction of the temporal progression of cell-type-specific differentiation and suggests possible plasticity among cells at the sensory-nonsensory boundary. Comparisons of cell types from utricles and cochleae demonstrate divergence between auditory and vestibular cells, despite a common origin. These results provide significant insights into the developmental processes that form unique inner ear cell types.
Mammalian hearing requires the development of the organ of Corti, a sensory epithelium comprising unique cell types. The limited number of each of these cell types, combined with their close ...proximity, has prevented characterization of individual cell types and/or their developmental progression. To examine cochlear development more closely, we transcriptionally profile approximately 30,000 isolated mouse cochlear cells collected at four developmental time points. Here we report on the analysis of those cells including the identification of both known and unknown cell types. Trajectory analysis for OHCs indicates four phases of gene expression while fate mapping of progenitor cells suggests that OHCs and their surrounding supporting cells arise from a distinct (lateral) progenitor pool. Tgfβr1 is identified as being expressed in lateral progenitor cells and a Tgfβr1 antagonist inhibits OHC development. These results provide insights regarding cochlear development and demonstrate the potential value and application of this data set.
We highlight concerns regarding the approval of relugolix for patients with prostate cancer. These include the unsuitable comparator arm and primary endpoint in the HERO trial, as well as potential ...selection bias and the poor representativeness of the trial population. Dosing adherence to a daily tablet may also be an issue in comparison to injections at 3-mo intervals. Rigorous postmarketing trials of relugolix assessing clinically meaningful endpoints for these patients are needed.
MYC is a highly validated oncogenic transcription factor and cancer target. However, the disordered nature of this protein has made it a challenging target, with no clinical stage, direct ...small-molecule MYC inhibitors available. Recent work leveraging a large
chemical library and a rapid
screen has expanded the chemotypes of direct small-molecule inhibitors (MYCi). Novel MYCi represent a class of improved MYC chemical probes that bind directly to MYC to inhibit its function and to promote its degradation by enhancing GSK3β-mediated phosphorylation. One of these compounds, MYCi975, has shown remarkable tolerability and efficacy
and is associated with a selective effect on MYC target gene expression. Additional effects of MYCi on the tumor immune microenvironment including immune cell infiltration and upregulation of PD-L1 expression provide a rationale for combining MYCi with anti-PD-1/PD-L1 therapy to enhance antitumor efficacy. Our strategy for developing MYCi demonstrates an efficient way to identify selective and well-tolerated MYC inhibitors. The new MYCi provide tools for probing MYC function and serve as starting points for the development of novel anti-MYC therapeutics.
Clinicians use several measures to ascertain whether individual patients will tolerate liberation from mechanical ventilation, including the rapid shallow breathing index (RSBI).
Given varied use of ...different thresholds, patient populations, and measurement characteristics, how well does RSBI predict successful extubation?
We searched six databases from inception through September 2019 and selected studies reporting the accuracy of RSBI in the prediction of successful extubation. We extracted study data and assessed quality independently and in duplicate.
We included 48 studies involving RSBI measurements of 10,946 patients. Pooled sensitivity for RSBI of < 105 in predicting extubation success was moderate (0.83 95% CI, 0.78-0.87, moderate certainty), whereas specificity was poor (0.58 95% CI, 0.49-0.66, moderate certainty) with diagnostic ORs (DORs) of 5.91 (95% CI, 4.09-8.52). RSBI thresholds of < 80 or 80 to 105 yielded similar sensitivity, specificity, and DOR. These findings were consistent across multiple subgroup analyses reflecting different patient characteristics and operational differences in RSBI measurement.
As a stand-alone test, the RSBI has moderate sensitivity and poor specificity for predicting extubation success. Future research should evaluate its role as a permissive criterion to undergo a spontaneous breathing trial (SBT) for patients who are at intermediate pretest probability of passing an SBT.
PROSPERO; No.: CRD42020149196; URL: www.crd.york.ac.uk/prospero/.
Aberrant activation of the small GTPase Ras by oncogenic mutation or constitutively active upstream receptor tyrosine kinases results in the deregulation of cellular signals governing growth and ...survival in ∼30% of all human cancers. However, the discovery of potent inhibitors of Ras has been difficult to achieve. Here, we report the identification of small molecules that bind to a unique pocket on the Ras:Son of Sevenless (SOS):Ras complex, increase the rate of SOS-catalyzed nucleotide exchange in vitro, and modulate Ras signaling pathways in cells. X-ray crystallography of Ras:SOS:Ras in complex with these molecules reveals that the compounds bind in a hydrophobic pocket in the CDC25 domain of SOS adjacent to the Switch II region of Ras. The structure–activity relationships exhibited by these compounds can be rationalized on the basis of multiple X-ray cocrystal structures. Mutational analyses confirmed the functional relevance of this binding site and showed it to be essential for compound activity. These molecules increase Ras-GTP levels and disrupt MAPK and PI3K signaling in cells at low micromolar concentrations. These small molecules represent tools to study the acute activation of Ras and highlight a pocket on SOS that may be exploited to modulate Ras signaling.
When ingested by children, small quantities of beta-adrenergic antagonists (BAA) are described as dangerous and even potentially lethal ("one pill can kill"). We characterize demographics, clinical ...characteristics, and the rate of serious outcomes among pediatric patients with reported BAA ingestions.
This study was a retrospective review of U.S. patients <20 years old with reported single-agent BAA ingestions presenting to a health care facility between January 2000 and February 2020 for whom a poison control center was consulted. Data were abstracted from the National Poison Data System (NPDS). Medical outcomes were assessed by the NPDS scale of no effect, minor effect, moderate effect, major effect, and death. All relevant NPDS fatality narratives were reviewed.
A total of 35,436 reported exposures were identified. A total of 29,155 (82.3%) were <6 years old, of which 29,089 (99.8%) were unintentional. Twenty-five patients (<0.1%) <6 years old had major effects. A total of 2316 (8.8%) of patients with no/mild effects were admitted to a critical care unit. Of all cases, 1460 (4.1%) had hypotension and 1403 (4.0%) had bradycardia. One hundred nineteen (0.3%) developed hypoglycemia. The only four fatalities resulted from intentional ingestions in patients >10 years old who sustained cardiac arrest in the prehospital setting.
Reported BAA ingestions in this multiyear national pediatric cohort caused infrequent toxicity, and no fatalities resulted from an unintentional ingestion. The frequency of bradycardia, hypotension, and hypoglycemia were low. While severely poisoned patients require aggressive treatment, 8.8% of patients were admitted to a critical care unit despite having no or mild effects, which suggests an opportunity to reduce resource utilization.
Characterized by the accumulation of somatic mutations in blood cell lineages, clonal hematopoiesis of indeterminate potential (CHIP) is frequent in aging and involves the expansion of mutated ...hematopoietic stem and progenitor cells (HSC/Ps) that leads to an increased risk of hematologic malignancy. However, the risk factors that contribute to CHIP-associated clonal hematopoiesis (CH) are poorly understood. Obesity induces a proinflammatory state and fatty bone marrow (FBM), which may influence CHIP-associated pathologies. We analyzed exome sequencing and clinical data for 47,466 individuals with validated CHIP in the UK Biobank. CHIP was present in 5.8% of the study population and was associated with a significant increase in the waist-to-hip ratio (WHR). Mouse models of obesity and CHIP driven by heterozygosity of Tet2, Dnmt3a, Asxl1, and Jak2 resulted in exacerbated expansion of mutant HSC/Ps due in part to excessive inflammation. Our results show that obesity is highly associated with CHIP and that a proinflammatory state could potentiate the progression of CHIP to more significant hematologic neoplasia. The calcium channel blockers nifedipine and SKF-96365, either alone or in combination with metformin, MCC950, or anakinra (IL-1 receptor antagonist), suppressed the growth of mutant CHIP cells and partially restored normal hematopoiesis. Targeting CHIP-mutant cells with these drugs could be a potential therapeutic approach to treat CH and its associated abnormalities in individuals with obesity.
Opioid-reduction policies have been enacted by US states to address the opioid epidemic. Evidence of an association between policy implementation and decreased rates of pediatric opioid poisoning ...provides further justification for expanded implementation of these policies.
To examine the association of 3 state-level opioid-reduction policies with the rate of opioid poisoning in children and adolescents.
This interrupted time series analysis used data from the National Poison Data System (NPDS), a database of poisoning information reported to poison control centers across the US. Individuals younger than 20 years who experienced poisoning associated with 1 or more prescription opioids from January 1, 2005, to November 30, 2017, were included. The analysis focused on 3 widespread policy interventions: the prescription drug monitoring program (PDMP), pain clinic legislation, and opioid prescribing guidelines. Data analysis was performed from January 30, 2020, to March 30, 2020.
Any opioid poisoning in individuals younger than 20 years that was reported to the NPDS.
Opioid poisoning rates per million person-months before and after implementation of each of the 3 policies, overall and stratified by age (≤4 years, 5-9 years, 10-14 years, and 15-19 years).
A total of 338 476 opioid poisoning incidences in children and young adults were reported to the NPDS within the study period. Of this study population, the mean (SD) age was 9.74 (7.15) years, and 179 011 (52.9%) were female. The implementation of a PDMP was associated with a reduction in the monthly rate of opioid poisoning in children and adolescents (-0.07 per million person-months; 95% CI, -0.09 to -0.04) in the postimplementation period. This reduction was observed for all age groups except for the 10- to 14-year age group (-0.03 per million person-months; 95% CI, -0.05 to 0.00). Pain clinic legislation was associated with an immediate reduction in opioid poisoning (-6.22 per million person-months; 95% CI, -8.98 to -3.47). This association was statistically significant across all ages except for the 4 years or younger group. Analysis of the association of implementation of opioid prescribing guidelines was limited because of insufficient follow-up data and did not show an immediate or monthly change in the rate of opioid poisoning.
Results of this study suggest that certain state-level opioid-reduction policies were associated with decreases in pediatric opioid exposures across age groups. Further examination of the underlying mechanisms of these associations, including age group-specific outcomes, may expand and strengthen policies that reduce opioid poisoning, misuse, and overdoses in children and adolescents.
Looking for fragments: A fragment‐based screen using NMR spectroscopy was applied to discover ligands that bind to the GTPase K‐Ras and modulate the activity of the nucleotide exchange factor Sos. ...Structural data on how these fragment‐derived hits bind to the guanosine diphosphate–K‐Ras complex (see picture) provides a starting point for the future discovery of drugs that target K‐Ras activation and signaling.
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