A single-cell transcriptomic map of the developing Atoh1 lineage identifies neural fate decisions and neuronal diversity in the hindbrain.

Proneural transcription factors establish molecular cascades to orchestrate neuronal diversity. One such transcription factor, Atonal homolog 1 (Atoh1), gives rise to cerebellar excitatory neurons and over 30 distinct nuclei in the brainstem critical for hearing, breathing, and balance. Although Atoh1 lineage neurons have been qualitatively described, the transcriptional programs that drive their fate decisions and the full extent of their diversity remain unknown. Here, we analyzed single-cell RNA sequencing and ATOH1 DNA binding in Atoh1 lineage neurons of the developing mouse hindbrain. This high-resolution dataset identified markers for specific brainstem nuclei and demonstrated that transcriptionally heterogeneous progenitors require ATOH1 for proper migration. Moreover, we identified a sizable population of proliferating unipolar brush cell progenitors in the mouse Atoh1 lineage, previously described in humans as the origin of one medulloblastoma subtype. Collectively, our data provide insights into the developing mouse hindbrain and markers for functional assessment of understudied neuronal populations.

Dental implant failures in Utah and US veteran cohorts.

INTRODUCTION: Approximately, 5.5 million dental implants are estimated to be surgically placed in the United States yearly, with an anticipated long-term failure rate ranging from 3% to 10%. At the Salt Lake City Dental Clinic within the Department of Veterans Affairs (VHA), specific protocols have been established to mandate that clinicians present every dental implant case for review by a committee. To understand the effectiveness of this approach, a comparative data analysis was undertaken to compare local dental implant failure data against national VHA data. METHODS: Leveraging electronic health records of veterans spanning from 2000 to 2021, we gathered procedural records related to dental implant placement or failure, demographic information, and medical history for individuals who received dental care at various dental clinics within the nationwide VHA network. Subsequently, statistical analyses were conducted using mixed-effects Poisson regression models with cluster-robust standard errors. Incident rate ratios (IRRs) for Utah-specific and nationwide cohorts were ascertained. RESULTS: The Utah VHA dental clinical data showed that there was a slightly lower prevalence of implant failure at 6.7% compared to the national cohort, which had a rate of 6.9%. The implant level failure rates were also low, with 4.20 (confidence interval [CI]: 3.68, 4.81) per 1000 implant placements per year for Utah cohorts. The adjusted IRR indicated a relative 16% reduction in risk among Utah Veterans (IRR 0.84, 95% CI [0.76-0.92]; p < 0.001). CONCLUSIONS: The stringent protocols in place at Salt Lake City, which integrate evidence-based practices and expert opinion for evaluating patient suitability for dental implant placement and subsequent care, contributed to the reduced risk among Utah Dental Clinic veterans pool compared to veterans of other states.

Atoh1 drives the heterogeneity of the pontine nuclei neurons and promotes their differentiation.

Pontine nuclei (PN) neurons mediate the communication between the cerebral cortex andthe cerebellum to refine skilled motor functions. Prior studies showed that PN neurons fall into two subtypes based on their anatomic location and region-specific connectivity, but the extent of their heterogeneity and its molecular drivers remain unknown. Atoh1 encodes a transcription factor that is expressed in the PN precursors. We previously showed that partial loss of Atoh1 function in mice results in delayed PN development and impaired motor learning. In this study, we performed single-cell RNA sequencing to elucidate the cell state-specific functions of Atoh1 during PN development and found that Atoh1 regulates cell cycle exit, differentiation, migration, and survival of PN neurons. Our data revealed six previously not known PN subtypes that are molecularly and spatially distinct. We found that the PN subtypes exhibit differential vulnerability to partial loss of Atoh1 function, providing insights into the prominence of PN phenotypes in patients with ATOH1 missense mutations.

MeCP2 regulates Gdf11, a dosage-sensitive gene critical for neurological function.

Loss- and gain-of-function of MeCP2 causes Rett syndrome (RTT) and MECP2 duplication syndrome (MDS), respectively. MeCP2 binds methyl-cytosines to finely tune gene expression in the brain, but identifying genes robustly regulated by MeCP2 has been difficult. By integrating multiple transcriptomics datasets, we revealed that MeCP2 finely regulates growth differentiation factor 11 (Gdf11). Gdf11 is down-regulated in RTT mouse models and, conversely, up-regulated in MDS mouse models. Strikingly, genetically normalizing Gdf11 dosage levels improved several behavioral deficits in a mouse model of MDS. Next, we discovered that losing one copy of Gdf11 alone was sufficient to cause multiple neurobehavioral deficits in mice, most notably hyperactivity and decreased learning and memory. This decrease in learning and memory was not due to changes in proliferation or numbers of progenitor cells in the hippocampus. Lastly, loss of one copy of Gdf11 decreased survival in mice, corroborating its putative role in aging. Our data demonstrate that Gdf11 dosage is important for brain function.

Disruption of the ATXN1-CIC complex reveals the role of additional nuclear ATXN1 interactors in spinocerebellar ataxia type 1.

Spinocerebellar ataxia type 1 (SCA1) is a paradigmatic neurodegenerative disease in that it is caused by a mutation in a broadly expressed protein, ATXN1; however, only select populations of cells degenerate. The interaction of polyglutamine-expanded ATXN1 with the transcriptional repressor CIC drives cerebellar Purkinje cell pathogenesis; however, the importance of this interaction in other vulnerable cells remains unknown. Here, we mutated the 154Q knockin allele of Atxn1154Q/2Q mice to prevent the ATXN1-CIC interaction globally. This normalized genome-wide CIC binding; however, it only partially corrected transcriptional and behavioral phenotypes, suggesting the involvement of additional factors in disease pathogenesis. Using unbiased proteomics, we identified three ATXN1-interacting transcription factors: RFX1, ZBTB5, and ZKSCAN1. We observed altered expression of RFX1 and ZKSCAN1 target genes in SCA1 mice and patient-derived iNeurons, highlighting their potential contributions to disease. Together, these data underscore the complexity of mechanisms driving cellular vulnerability in SCA1.

Critical care paramedics' experiences of performing an emergency scalpel cricothyroidotomy: a qualitative study.

Introduction: A scalpel cricothyroidotomy or front of neck access (FONA) is a rarely performed part of airway management for when other steps have failed and the patient cannot be intubated or ventilated. Increasingly advanced and specialist paramedics are being trained to perform this procedure within the pre-hospital environment. Methods: Advanced and specialist paramedics within a UK ambulance service that had performed a FONA were invited to participate in this qualitative research. Semi-structured interviews were used to gather information on the participants' experiences. This information underwent thematic analysis to develop codes which were then grouped into themes. Results: Seven participants were interviewed between December 2020 and January 2021. Three main themes were identified: the procedure, isolation and training. The main complications described were bleeding in excess of expectations, moving structures, surgical emphysema and a false track. Conclusion: Complications appeared common; training to perform a FONA should include complications and an approach to their management similar to other airway management procedures. Isolation was a common theme within this study, however remote support from a peer appeared beneficial.

Disruption of MeCP2-TCF20 complex underlies distinct neurodevelopmental disorders.

MeCP2 is associated with Rett syndrome (RTT), MECP2 duplication syndrome, and a number of conditions with isolated features of these diseases, including autism, intellectual disability, and motor dysfunction. MeCP2 is known to broadly bind methylated DNA, but the precise molecular mechanism driving disease pathogenesis remains to be determined. Using proximity-dependent biotinylation (BioID), we identified a transcription factor 20 (TCF20) complex that interacts with MeCP2 at the chromatin interface. Importantly, RTT-causing mutations in MECP2 disrupt this interaction. TCF20 and MeCP2 are highly coexpressed in neurons and coregulate the expression of key neuronal genes. Reducing Tcf20 partially rescued the behavioral deficits caused by MECP2 overexpression, demonstrating a functional relationship between MeCP2 and TCF20 in MECP2 duplication syndrome pathogenesis. We identified a patient exhibiting RTT-like neurological features with a missense mutation in the PHF14 subunit of the TCF20 complex that abolishes the MeCP2-PHF14-TCF20 interaction. Our data demonstrate the critical role of the MeCP2-TCF20 complex for brain function.

Losing Dnmt3a dependent methylation in inhibitory neurons impairs neural function by a mechanism impacting Rett syndrome.

Methylated cytosine is an effector of epigenetic gene regulation. In the brain, Dnmt3a is the sole 'writer' of atypical non-CpG methylation (mCH), and MeCP2 is the only known 'reader' for mCH. We asked if MeCP2 is the sole reader for Dnmt3a dependent methylation by comparing mice lacking either protein in GABAergic inhibitory neurons. Loss of either protein causes overlapping and distinct features from the behavioral to molecular level. Loss of Dnmt3a causes global loss of mCH and a subset of mCG sites resulting in more widespread transcriptional alterations and severe neurological dysfunction than MeCP2 loss. These data suggest that MeCP2 is responsible for reading only part of the Dnmt3a dependent methylation in the brain. Importantly, the impact of MeCP2 on genes differentially expressed in both models shows a strong dependence on mCH, but not Dnmt3a dependent mCG, consistent with mCH playing a central role in the pathogenesis of Rett Syndrome.

Presence of a pre-hospital enhanced care team reduces on scene time and improves triage compliance for stab trauma.

BACKGROUND: A reduction in pre-hospital scene time for patients with penetrating trauma is associated with reduced mortality, when combined with appropriate hospital triage. This study investigated the relationship between presence of pre-hospital enhanced care teams (ECT) (Critical Care Paramedics (CCPS) or Helicopter Emergency Medical Service (HEMS)), on the scene time and triage compliance, of penetrating trauma patients in a UK ambulance service. The primary outcome was whether scene time reduces when an ECT is present. A secondary outcome was whether the presence of an ECT improved compliance with the trust's Major Trauma Decision Tree (MTDT). METHODS: All suspected penetrating trauma incidents involving a patient's torso were identified from the Trust's computer-aided dispatch (CAD) system between 31st March 2017 and 1st April 2018. Only patients who sustained central penetrating trauma were included. Any incidents involving firearms were excluded due to the prolonged times that can be involved when waiting for specialist police units. Data relevant to scene time for each eligible incident were retrieved, along with the presence or absence of an ECT. The results were analysed to identify trends in the scene times and compliance with the MTDT. RESULTS: One hundred seventy-one patients met the inclusion criteria, with 165 having complete data. The presence of an ECT improved the median on-scene time in central stabbing by 38% (29m50s vs. 19m0s, p = 0.03). The compliance with the trust's MTDT increased dramatically when an ECT is present (81% vs. 37%, odds ratio 7.59, 95% CI, 3.70-15.37, p < 0.0001). CONCLUSIONS: The presence of an ECT at a central stabbing incident significantly improved the scene time and triage compliance with a MTDT. Ambulance services should consider routine activation of ECTs to such incidents, with subsequent service evaluation to monitor patient outcomes. Ambulance services should continue to strive to reduce scene times in the context of central penetrating trauma.

Digitally Augmented Learning in Implant Dentistry.

The economic forces in the dental education industry yield a high cost for a dental degree, yet the financial return for this education yields a small margin above the costs for this degree. Industries with unfavorable return to investment ratios tend to be vulnerable to changes. Productive technologies are emerging that may be useful in improving the return to investment ratios in dental education. Virtual reality and online learning provide productive value that could be useful to the dental education industry. A description and use cases of virtual reality in dental implantology education are provided.

Complex Dental Implant Cases: Algorithms, Subjectivity, and Patient Cases Along the Complexity Continuum.

Algorithms for predictable outcomes, or checklists in health care, have been widely supported due to their highly effective outcomes. This article shares "algorithmic roadmaps" to restore single-tooth, partially edentulous, and fully edentulous complex dental implant cases in the patient population. A review of the current literature is presented to provide systematic assessments followed by criteria in a checklist format that allows the surgeon and restorative dentist to determine whether a removable or fixed implant prosthesis is the best patient option. Several cases have been chosen to illustrate the algorithms the authors used to provide an optimized prognosis for surgical/restorative success.

Targeted response? An exploration of why ambulance services find government targets particularly challenging.

INTRODUCTION OR BACKGROUND: Ambulance services have historically found their targets particularly challenging. This article explores some areas of this multifaceted problem. SOURCES OF DATA: Research articles, government publications and published audit data. AREAS OF AGREEMENT: Demand is increasing in many areas of healthcare, but whilst hospitals saw a 7% increase in demand in recent times, ambulance services saw nearly double that. The services ambulance trusts provide have evolved from that of a transport service to that of a mobile health provider, and they have become victims of their own success. AREAS OF CONTROVERSY: Ambulance targets have never evolved to match evolving care. Ambulance personnel strive to avoid hospital attendance where appropriate, but this can be difficult for a 24-hour service, when not all referral pathways have 24-hour referral systems. GROWING POINTS: We discuss why demand might be growing disproportionately for ambulance services, and challenge the appropriateness of the targets themselves. AREAS TIMELY FOR DEVELOPING RESEARCH: Possible formats for revised ambulance targets are discussed.

The chromatin remodeling protein CHD7, mutated in CHARGE syndrome, is necessary for proper craniofacial and tracheal development.

BACKGROUND: Heterozygous mutations in the chromatin remodeling gene CHD7 cause CHARGE syndrome, a developmental disorder with variable craniofacial dysmorphisms and respiratory difficulties. The molecular etiologies of these malformations are not well understood. Homozygous Chd7 null mice die by E11, whereas Chd7(Gt/+) heterozygous null mice are a viable and excellent model of CHARGE. We explored skeletal phenotypes in Chd7(Gt/+) and Chd7 conditional knockout mice, using Foxg1-Cre to delete Chd7 (Foxg1-CKO) in the developing eye, ear, nose, pharyngeal pouch, forebrain, and gut and Wnt1-Cre (Wnt1-CKO) to delete Chd7 in migrating neural crest cells. RESULTS: Foxg1-CKO mice exhibited postnatal respiratory distress and death, dysplasia of the eye, concha, and frontal bone, hypoplastic maxillary shelves and nasal epithelia, and reduced tracheal rings. Wnt1-CKO mice exhibited frontal and occipital bone dysplasia, hypoplasia of the maxillary shelves and mandible, and cleft palate. In contrast, heterozygous Chd7(Gt/+) mice had apparently normal skeletal development. CONCLUSIONS: Conditional deletion of Chd7 in ectodermal and endodermal derivatives (Foxg1-Cre) or migrating neural crest cells (Wnt1-Cre) results in varied and more severe craniofacial defects than in Chd7(Gt/+) mice. These studies indicate that CHD7 has an important, dosage-dependent role in development of several different craniofacial tissues.

Macrocerebellum, epilepsy, intellectual disability, and gut malrotation in a child with a 16q24.1-q24.2 contiguous gene deletion.

Macrocerebellum is a rare condition characterized by enlargement of the cerebellum with conservation of the overall shape and cytoarchitecture. Here, we report on a child with a distinctive constellation of clinical features including macrocerebellum, epilepsy, apparent intellectual disability, dysautonomia, gut malrotation, and poor gut motility. Oligonucleotide chromosome microarray analysis identified a 16q24.1-q24.2 deletion that included four OMIM genes (FBXO31, MAP1LC3B, JPH3, and SLC7A5). Review of prior studies describing individuals with similar or overlapping16q24.1-q24.2 deletions identified no other reports of macrocerebellum. These observations highlight a potential genetic cause of this rare disorder and raise the possibility that one or more gene(s) in the 16q24.1-q24.2 interval regulate cerebellar development.

CHD7 and retinoic acid signaling cooperate to regulate neural stem cell and inner ear development in mouse models of CHARGE syndrome.

CHARGE syndrome is a multiple congenital anomaly disorder that leads to life-threatening birth defects, such as choanal atresia and cardiac malformations as well as multiple sensory impairments, that affect hearing, vision, olfaction and balance. CHARGE is caused by heterozygous mutations in CHD7, which encodes an ATP-dependent chromatin remodeling enzyme. Identification of the mechanisms underlying neurological and sensory defects in CHARGE is a first step toward developing treatments for CHARGE individuals. Here, we used mouse models of Chd7 deficiency to explore the function of CHD7 in the development of the subventricular zone (SVZ) neural stem cell niche and inner ear, structures that are important for olfactory bulb neurogenesis and hearing and balance, respectively. We found that loss of Chd7 results in cell-autonomous proliferative, neurogenic and self-renewal defects in the perinatal and mature mouse SVZ stem cell niche. Modulation of retinoic acid (RA) signaling prevented in vivo inner ear and in vitro neural stem cell defects caused by Chd7 deficiency. Our findings demonstrate critical, cooperative roles for RA and CHD7 in SVZ neural stem cell function and inner ear development, suggesting that altered RA signaling may be an effective method for treating Chd7 deficiency.

Wide-field compact catadioptric telescope spanning 0.7-14 µm wavelengths.

We present a wide-field compact f-1.2, f-1.6 effective illumination catadioptric telescope that spans the wavelengths 0.7-14.0 µm. Such a telescope replaces several telescopes designed for different infrared bands, while having a track length shorter than most single-band telescopes. Incorporated with a suitable multiband focal plane array, many wavelength bands may be imaged simultaneously in the same instrument. We have constructed and tested prototypes of the telescopes and found the performance is near the predicted values.

Disruption of RAB40AL function leads to Martin--Probst syndrome, a rare X-linked multisystem neurodevelopmental human disorder.

BACKGROUND AND AIM: Martin--Probst syndrome (MPS) is a rare X-linked disorder characterised by deafness, cognitive impairment, short stature and distinct craniofacial dysmorphisms, among other features. The authors sought to identify the causative mutation for MPS. METHODS AND RESULTS: Massively parallel sequencing in two affected, related male subjects with MPS identified a RAB40AL (also called RLGP) missense mutation (chrX:102,079,078-102,079,079AC→GA p.D59G; hg18). RAB40AL encodes a small Ras-like GTPase protein with one suppressor of cytokine signalling box. The p.D59G variant is located in a highly conserved region of the GTPase domain between ß-2 and ß-3 strands. Using RT-PCR, the authors show that RAB40AL is expressed in human fetal and adult brain and kidney, and adult lung, heart, liver and skeletal muscle. RAB40AL appears to be a primate innovation, with no orthologues found in mouse, Xenopus or zebrafish. Western analysis and fluorescence microscopy of GFP-tagged RAB40AL constructs from transiently transfected COS7 cells show that the D59G missense change renders RAB40AL unstable and disrupts its cytoplasmic localisation. CONCLUSIONS: This is the first study to show that mutation of RAB40AL is associated with a human disorder. Identification of RAB40AL as the gene mutated in MPS allows for further investigations into the molecular mechanism(s) of RAB40AL and its roles in diverse processes such as cognition, hearing and skeletal development.

Ivory wave: the next mephedrone?

BACKGROUND: Since the classification of miaow miaow (mephedrone) as a class B drug in April this year, a new drug is emerging as a so-called 'legal high'. Deaths have already been attributed to ivory wave in different parts of the country. METHOD: A case study is presented, and relevant literature is explored in order to better understand the drug and its effects in the human body. RESULTS: Overstimulation of the nervous system can cause acute paranoid psychosis, dizziness, hyperthermia and potential fitting. Effects on the cardiovascular system include tachycardia, chest pains, S-T segment changes, and blood pressure variations with potential renal implications. CONCLUSION: Ivory wave's popularity seems to be growing and it seems quite plausible that this drug could become 'the next mephedrone'. Clinicians should be aware of its likely presentations, dangers, and management.