A Suite of Transgenic Driver and Reporter Mouse Lines with Enhanced Brain-Cell-Type Targeting and Functionality.

Modern genetic approaches are powerful in providing access to diverse cell types in the brain and facilitating the study of their function. Here, we report a large set of driver and reporter transgenic mouse lines, including 23 new driver lines targeting a variety of cortical and subcortical cell populations and 26 new reporter lines expressing an array of molecular tools. In particular, we describe the TIGRE2.0 transgenic platform and introduce Cre-dependent reporter lines that enable optical physiology, optogenetics, and sparse labeling of genetically defined cell populations. TIGRE2.0 reporters broke the barrier in transgene expression level of single-copy targeted-insertion transgenesis in a wide range of neuronal types, along with additional advantage of a simplified breeding strategy compared to our first-generation TIGRE lines. These novel transgenic lines greatly expand the repertoire of high-precision genetic tools available to effectively identify, monitor, and manipulate distinct cell types in the mouse brain.

Conserved and divergent gene regulatory programs of the mammalian neocortex.

Divergence of cis-regulatory elements drives species-specific traits1, but how this manifests in the evolution of the neocortex at the molecular and cellular level remains unclear. Here we investigated the gene regulatory programs in the primary motor cortex of human, macaque, marmoset and mouse using single-cell multiomics assays, generating gene expression, chromatin accessibility, DNA methylome and chromosomal conformation profiles from a total of over 200,000 cells. From these data, we show evidence that divergence of transcription factor expression corresponds to species-specific epigenome landscapes. We find that conserved and divergent gene regulatory features are reflected in the evolution of the three-dimensional genome. Transposable elements contribute to nearly 80% of the human-specific candidate cis-regulatory elements in cortical cells. Through machine learning, we develop sequence-based predictors of candidate cis-regulatory elements in different species and demonstrate that the genomic regulatory syntax is highly preserved from rodents to primates. Finally, we show that epigenetic conservation combined with sequence similarity helps to uncover functional cis-regulatory elements and enhances our ability to interpret genetic variants contributing to neurological disease and traits.

Human neocortical expansion involves glutamatergic neuron diversification.

The neocortex is disproportionately expanded in human compared with mouse1,2, both in its total volume relative to subcortical structures and in the proportion occupied by supragranular layers composed of neurons that selectively make connections within the neocortex and with other telencephalic structures. Single-cell transcriptomic analyses of human and mouse neocortex show an increased diversity of glutamatergic neuron types in supragranular layers in human neocortex and pronounced gradients as a function of cortical depth3. Here, to probe the functional and anatomical correlates of this transcriptomic diversity, we developed a robust platform combining patch clamp recording, biocytin staining and single-cell RNA-sequencing (Patch-seq) to examine neurosurgically resected human tissues. We demonstrate a strong correspondence between morphological, physiological and transcriptomic phenotypes of five human glutamatergic supragranular neuron types. These were enriched in but not restricted to layers, with one type varying continuously in all phenotypes across layers 2 and 3. The deep portion of layer 3 contained highly distinctive cell types, two of which express a neurofilament protein that labels long-range projection neurons in primates that are selectively depleted in Alzheimer's disease4,5. Together, these results demonstrate the explanatory power of transcriptomic cell-type classification, provide a structural underpinning for increased complexity of cortical function in humans, and implicate discrete transcriptomic neuron types as selectively vulnerable in disease.

Preseptal transconjunctival approach in orbital floor fracture repairs to prevent postoperative lower eyelid malposition.

PURPOSE: Lower eyelid malposition can be a complication following orbital floor fracture surgeries. We present our incidence of lower eyelid malposition from a large case series of orbital floor fracture repairs using the 'swinging eyelid' approach and 'hang back' technique. METHODS: A retrospective review of all orbital fracture surgeries at our institution from November 2011 to March 2021 was performed. Primary outcomes included the incidence of lower eyelid malposition by category, the average time to presentation after primary surgery, and reoperation rates among cases with lower eyelid complications. RESULTS: A total of 438 cases that involved repair of the fractured orbital floor were identified. Six patients (1.37 %) developed lower eyelid malposition following primary orbital floor repair. Two patients (0.46 %) developed reverse ptosis of the lower eyelid. Two patients (0.46 %) returned with lower lid cicatricial ectropion. One patient (0.23 %) had postoperative lower eyelid retraction. One patient (0.23 %) had postoperative lower eyelid cicatricial entropion. No cases of lower lid flattening, lower eyelid fat flattening, or eyelid notch was noted. All patients with lower eyelid malposition underwent additional surgeries except one patient with reverse ptosis (83.3 %). The average time to the presentation of postoperative complications from the surgery date was 292.8 days (range = 49 days to 3.5 years). CONCLUSION: Lower eyelid malposition after orbital floor repair is a known complication that can be decreased by employing the 'swinging eyelid' with a preseptal approach and closure by the 'hang back' technique.

Wraparound nylon foil implant for isolated orbital floor fractures.

PURPOSE: There are a variety of implant materials available for orbital floor fracture repair. Implant selection is guided by surgeon experience, availability, and patient specific needs. The purpose of this study is to describe a "wraparound" technique for nylon foil implant placement for large, isolated floor fractures that provides excellent results with low incidence of enophthalmos or other complications. MATERIALS AND METHODS: A retrospective chart review from 2012 to 2020 was conducted in patients who underwent isolated orbital floor fracture repair with the use of the "wraparound" nylon foil implant. The surgical technique is described. Preoperative CT scans were assessed, and the patients were divided into groups based on the size of the floor fracture. Postoperative data was collected including Hertel measurements and complications related to the implant. RESULTS: There were eighty patients who underwent orbital floor fracture repair with the described technique and had adequate follow-up. There were 18 (22.5%) small-sized fractures, 32 (40%) medium-sized fractures, and 30 (37.5%) large-sized fractures in the study group. One patient (3.33%) in the large fracture group had clinically significant enophthalmos of 2 mm postoperatively. There were no other patients with clinically significant enophthalmos. There were no instances of any complications related to the implant, and no patients required implant removal. CONCLUSIONS: The "wraparound" technique for a nylon foil implant provides excellent results for isolated orbital floor fractures. It provides more support and stability than traditional nylon implants for larger fractures and has minimal complication rates.

Topical Oral and Intranasal Antiviral Agents for Coronavirus Disease 2019 (COVID-19).

With the largest viral loads in both symptomatic and asymptomatic patients with Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) present in the oral and nasal cavities, agents that act on these two areas have the potential for large therapeutic and prophylactic benefit. A literature review was conducted to elucidate the possible agents useful in treatment of SARS-CoV-2. These agents were evaluated for their current applications, adverse reactions, their current state of study, and any future considerations in their management of coronavirus disease 2019 (COVID-2019). Our review has found that, while there are many promising agents with proven efficacy in their in-vitro efficacy against SARS-CoV-2, more clinical trials and in-vivo studies, as well as safety trials, must be conducted before these agents can be effectively implemented.

A flexible organic reflectance oximeter array.

Transmission-mode pulse oximetry, the optical method for determining oxygen saturation in blood, is limited to only tissues that can be transilluminated, such as the earlobes and the fingers. The existing sensor configuration provides only single-point measurements, lacking 2D oxygenation mapping capability. Here, we demonstrate a flexible and printed sensor array composed of organic light-emitting diodes and organic photodiodes, which senses reflected light from tissue to determine the oxygen saturation. We use the reflectance oximeter array beyond the conventional sensing locations. The sensor is implemented to measure oxygen saturation on the forehead with 1.1% mean error and to create 2D oxygenation maps of adult forearms under pressure-cuff-induced ischemia. In addition, we present mathematical models to determine oxygenation in the presence and absence of a pulsatile arterial blood signal. The mechanical flexibility, 2D oxygenation mapping capability, and the ability to place the sensor in various locations make the reflectance oximeter array promising for medical sensing applications such as monitoring of real-time chronic medical conditions as well as postsurgery recovery management of tissues, organs, and wounds.

Ocular motility and diplopia measurements following orbital floor fracture repair.

PURPOSE: Diplopia and ocular motility restriction following orbital fracture repair are common complications. The reported rates in the literature differ greatly, in part due to varying definitions of diplopia and methods of measurement. The purpose of this study is to describe a practical and efficient in-office method for examining ocular motility and diplopia in orbital trauma patients and to report the outcomes in a series of patients who underwent orbital floor fracture repair. MATERIALS AND METHODS: A retrospective chart review from 2012 to 2019 was conducted in patients who underwent isolated orbital floor fracture repair within 3 weeks of trauma. All patients had examinations to assess extraocular motility and subjective diplopia using the described techniques. RESULTS: Ninety-three patients underwent orbital floor fracture repair and had adequate follow-up. Preoperatively, 71 (76%) patients had some restriction in motility and 59 (63%) patients complained of diplopia. Postoperatively, only 1 patient (1.09%) had clinically significant diplopia. Five (5.4%) additional patients demonstrated mild restriction in supraduction upon detailed ophthalmic examination that was not discovered upon subjective history. No patients had worsening of diplopia or motility after surgery. CONCLUSIONS: Diplopia and motility restriction following orbital fracture repair can be a persistent problem for some patients. It is important to perform a careful ophthalmic examination to detect motility deficits and diplopia that can be significant to the patient. The true rate of restriction and diplopia may be higher using detailed ophthalmic diagnostic techniques compared to subjective patient history.

Aerosol and droplet generation from orbital repair: Surgical risk in the pandemic era.

INTRODUCTION: The highly contagious COVID-19 has resulted in millions of deaths worldwide. Physicians performing orbital procedures may be at increased risk of occupational exposure to the virus due to exposure to secretions. The goal of this study is to measure the droplet and aerosol production during repair of the inferior orbital rim and trial a smoke-evacuating electrocautery handpiece as a mitigation device. MATERIAL AND METHODS: The inferior rim of 6 cadaveric orbits was approached transconjunctivally using either standard or smoke-evacuator electrocautery and plated using a high-speed drill. Following fluorescein inoculation, droplet generation was measured by counting under ultraviolet-A (UV-A) light against a blue background. Aerosol generation from 0.300-10.000 µm was measured using an optical particle sizer. Droplet and aerosol generation was compared against retraction of the orbital soft tissue as a negative control. RESULTS: No droplets were observed following the orbital approach using electrocautery. Visible droplets were observed after plating with a high-speed drill for 3 of 6 orbits. Total aerosol generation was significantly higher than negative control following the use of standard electrocautery. Use of smoke-evacuator electrocautery was associated with significantly lower aerosol generation in 2 of 3 size groups and in total. There was no significant increase in total aerosols associated with high-speed drilling. DISCUSSION AND CONCLUSIONS: Droplet generation for orbital repair was present only following plating with high-speed drill. Aerosol generation during standard electrocautery was significantly reduced using a smoke-evacuating electrocautery handpiece. Aerosols were not significantly increased by high-speed drilling.

Aerosol and droplet generation from mandible and midface fixation: Surgical risk in the pandemic era.

PURPOSE: The COVID-19 pandemic has led to concerns over transmission risk from healthcare procedures, especially when operating in the head and neck such as during surgical repair of facial fractures. This study aims to quantify aerosol and droplet generation from mandibular and midface open fixation and measure mitigation of airborne particles by a smoke evacuating electrocautery hand piece. MATERIALS AND METHODS: The soft tissue of the bilateral mandible and midface of two fresh frozen cadaveric specimens was infiltrated using a 0.1% fluorescein solution. Surgical fixation via oral vestibular approach was performed on each of these sites. Droplet splatter on the surgeon's chest, facemask, and up to 198.12 cm (6.5 ft) away from each surgical site was measured against a blue background under ultraviolet-A (UV-A) light. Aerosol generation was measured using an optical particle sizer. RESULTS: No visible droplet contamination was observed for any trials of mandible or midface fixation. Total aerosolized particle counts from 0.300-10.000 µm were increased compared to baseline following each use of standard electrocautery (n = 4, p < 0.001) but not with use of a suction evacuating electrocautery hand piece (n = 4, p = 0.103). Total particle counts were also increased during use of the powered drill (n = 8, p < 0.001). CONCLUSIONS: Risk from visible droplets during mandible and midface fixation is low. However, significant increases in aerosolized particles were measured after electrocautery use and during powered drilling. Aerosol dispersion is significantly decreased with the use of a smoke evacuating electrocautery hand piece.

Functional consequences of mutations in postsynaptic scaffolding proteins and relevance to psychiatric disorders.

Functional studies on postsynaptic scaffolding proteins at excitatory synapses have revealed a plethora of important roles for synaptic structure and function. In addition, a convergence of recent in vivo functional evidence together with human genetics data strongly suggest that mutations in a variety of these postsynaptic scaffolding proteins may contribute to the etiology of diverse human psychiatric disorders such as schizophrenia, autism spectrum disorders, and obsessive-compulsive spectrum disorders. Here we review the most recent evidence for several key postsynaptic scaffolding protein families and explore how mouse genetics and human genetics have intersected to advance our knowledge concerning the contributions of these important players to complex brain function and dysfunction.

How does cross-conjugation influence thiol additions to enones? A computational study of thiol trapping by the naturally occurring divinyl ketones zerumbone and α-santonin.

Density functional theory calculations are reported which explore how the kinetics and thermodynamics of thiol additions to enones are affected by the incorporation of the enone into a cross-conjugated divinyl ketone moiety. Computations with ωB97X-D//M06-2X indicate that in the parent acyclic system (1,4-pentadien-3-one), cross-conjugation has a small stabilizing effect on the thiol adduct, making the ΔG for the addition slightly more negative, and a larger stabilizing effect on the transition state, lowering ΔG‡. By contrast, in the parent six-membered cyclic system (2,5-cyclohexadien-1-one), cross-conjugation makes ΔG significantly less negative while causing only a small increase in ΔG‡. Both scenarios correspond to a more reversible addition. Thiol additions to two naturally occurring divinyl ketones, zerumbone and α-santonin, are examined. Previous NMR-based assays had shown that zerumbone forms mono- and bis-thiol adducts while α-santonin showed no detectable adduct formation. Computations reveal that the eleven-membered ring structure of zerumbone accelerates thiol trapping, relative to an analogous acyclic model. For α-santonin, the computations reveal that thiol addition is actually also rather facile, and it likely does occur, but the adduct is unstable and rapidly eliminates the thiol. These results illustrate that the inability to detect a thiol adduct in an experimental assay does not necessarily imply that the adduct does not form; instead it may simply be a manifestation of a rapid addition/elimination equilibrium in which the adduct concentration is below the limits of detectability.

Patient satisfaction survey experience among American otolaryngologists.

BACKGROUND: Patient Satisfaction (PS) is a commonly used metric in health care settings to assess the quality of care given by physicians. Monitoring physicians in this way may impact physician quality of life. Studies evaluating this impact are not available. This study sought to examine the physician experience of measuring PS among practicing otolaryngologists. METHODS: Using an online survey platform, a 34-item survey was given to practicing otolaryngologists through email distribution. The survey included questions about physician, practice and patient demographics, as well as inquiries regarding the way in which PS was measured and how it affected physician work and personal life. Data from these questions were reviewed and analyzed. RESULTS: 174 otolaryngologists responded to the survey. A majority of physicians' (55.3%) PS scores had been tracked with 89.9% reporting being tracked for a length of at least 1 year. PS scores for individual physicians were noted to be inconsistent and vary significantly between reports. Measuring patient satisfaction led to increased occupational stress, yet most physicians (63.8%) felt the monitoring did not lead to improvements in their practice. Some physicians (36.2%) reported that the collection of patient satisfaction scores had negatively influenced the way they practiced medicine, including the pressure to order superfluous tests or to prescribe unnecessary medications. CONCLUSION: Overall, physicians are negatively affected by the tracking of patient satisfaction scores. Occupational stress caused by the collection of patient satisfaction scores may contribute to physician burnout.

Nasal bone fractures and the use of radiographic imaging: An otolaryngologist perspective.

OBJECTIVE: To determine radiologic preferences of practicing otolaryngologists regarding isolated nasal bone fractures. STUDY DESIGN: An 8-question survey on isolated nasal bone fractures was designed. SETTING: Surveys were sent to all otolaryngology residency program directors for distribution among residents and faculty. Additional surveys were distributed to private practice otolaryngology groups. RESULTS: 140 physicians responded to the survey. 57% of the respondents were practicing otolaryngologists (75% with 10+ years of experience), while 43% of respondents were residents-in-training. 56% of respondents treated 1-5 nasal bone fractures per month. 80% of all respondents reported imaging being performed prior to consultation. If imaging was obtained before consultation, plain films and computed tomography (CT) maxillofacial/sinus scans were the most frequent modalities. 33% of residents and 70% of practicing otolaryngologists report imaging as 'rarely' or 'never' helpful in guiding management. 42% of residents and 20% of practicing otolaryngologists report asking for imaging when it wasn't already obtained. Decreased use of radiography was associated with greater years in practice and higher frequency of fractures treated. CONCLUSIONS AND RELEVANCE: Otolaryngologists seldom request imaging to evaluate and treat isolated nasal bone fractures. When ordered, imaging is utilized more often among residents-in-training and non-otolaryngology consulting physicians. This study highlights an opportunity to educate primary care and emergency room providers as well as otolaryngology residents on the value of comprehensive physical exam over radiographic imaging in the work-up of isolated nasal fractures. In addition, widespread adoption of a "no x-ray policy" in this setting may result in better resource utilization.

Post-operative epiphora following the transcutaneous medial canthal incision.

PURPOSE: The safety profile of the transcutaneous medial canthal incision for access to the medial orbit is assessed with a focus on the risk of post-operative iatrogenic epiphora. METHODS: A retrospective chart review of patients undergoing medial orbitotomy via the transcutaneous medial canthal incision was performed. Patients with a minimum of 3 months of follow-up were included and post-operative complications were assessed and characterized. RESULTS: One-hundred-fifty patients were included in the study. A total of 4 complications were identified, including one each of the following: nasolacrimal duct obstruction, hypertrophic scar, suture granuloma and soft tissue infection. Only the nasolacrimal duct obstruction required surgical intervention. DISCUSSION: Access to the medial orbit has been achieved through a variety of approaches, each with their own benefits and risk profile. The transcaruncular approach has increased in usage as a means to avoid a visible cutaneous scar and decrease the risk of iatrogenic epiphora, however, there are specific patients who may have relative contraindications to this approach. The current study demonstrates the low risk profile of the transcutaneous medial canthal incision, specifically the minimal risk of iatrogenic damage to the nasolacrimal outflow system. This approach is another useful tool which orbit surgeons should be familiar with to offer as an option to patients requiring medial orbitotomy.

A hybrid technique to address exposure keratopathy secondary to facial nerve paresis: A combination of a lateral tarsorrhaphy and lateral wedge resection.

PURPOSE: To present the results of treating combined lower eyelid laxity, retraction and midface descent secondary to facial nerve weakness with a hybrid surgical procedure. MATERIALS AND METHODS: A retrospective analysis of patients from January 2015 to January 2017 who underwent a hybrid surgical technique for the treatment of corneal exposure secondary to facial nerve paresis with a single surgeon was performed. Age, gender, and presence of exposure symptoms were recorded pre-operatively. Outcomes assessed included improvement of lower eyelid laxity and position, operative complications, and post-operative symptomatic relief. RESULTS: A total of 11 patients underwent unilateral eyelid surgery. All patients had symptomatic relief and good functional outcomes defined as improvement in eyelid laxity, lower eyelid position, and objective corneal exposure. No cases required reoperation during an average follow up of 174.5 days. CONCLUSIONS: Combining portions of a tarsorrhaphy and lateral wedge resection technique is a simple and effective procedure to improve lower eyelid position and limit corneal exposure secondary to facial nerve paresis.