Positive Trends in Racial Disparities for Head and Neck Microvascular Reconstructive Surgery.

OBJECTIVE: To evaluate national trends in racial disparities for patients undergoing head and neck reconstructive surgery. METHODS: Retrospective analysis using the 2008 to 2021 American College of Surgeons National Surgical Quality Improvement Program database. Patients receiving microvascular free tissue transfer were eligible for inclusion. Pediatric patients and those treated by non-otolaryngologists were excluded. Outcomes were analyzed with univariate and multivariable models. RESULTS: A total of 5831 head and neck free flap cases were analyzed, 4869 (83.5%) were White, 560 (9.6%) were Black or African American, and 402 (6.9%) were Asian, Native American, or other groups (ANAOG). The proportion of Black or African American patients and ANAOG patients undergoing free tissue transfer increased significantly over the time period (p = 0.047 and p = 0.010, respectively). However, there was a downtrend that started around 2017. In a multivariable model, Black or African American race was not associated with readmission (OR = 0.99 [95% CI 0.74, 1.31], p > 0.05), returning to the operating room (OR = 1.20 [95% CI 0.96, 1.49], p > 0.05), or any post-operative complication (OR = 0.83 [95% CI 0.68, 1.01], p > 0.05). There were also no significant associations found in the ANAOG population on multivariate analysis (p > 0.05 for all). CONCLUSION: The percentage of free tissue transfer performed in patients from minority backgrounds with head and neck cancer has been increasing in the United States. Outcomes after head and neck microvascular reconstruction are similar when stratified by race. However, racial disparities remain and further work is necessary to reduce these disparities. LEVEL OF EVIDENCE: Level IV Laryngoscope, 2024.

Role of STIM1 in stretch-induced signaling in human airway smooth muscle.

Alteration in the normal mechanical forces of breathing can contribute to changes in contractility and remodeling characteristic of airway diseases, but the mechanisms that mediate these effects in airway cells are still under investigation. Airway smooth muscle (ASM) cells contribute to both contractility and extracellular matrix (ECM) remodeling. In this study, we explored ASM mechanisms activated by mechanical stretch, focusing on mechanosensitive piezo channels and the key Ca2+ regulatory protein stromal interaction molecule 1 (STIM1). Expression of Ca2+ regulatory proteins, including STIM1, Orai1, and caveolin-1, mechanosensitive ion channels Piezo-1 and Piezo-2, and NLRP3 inflammasomes were upregulated by 10% static stretch superimposed on 5% cyclic stretch. These effects were blunted by STIM1 siRNA. Histamine-induced [Ca2+]i responses and inflammasome activation were similarly blunted by STIM1 knockdown. These data show that the effects of mechanical stretch in human ASM cells are mediated through STIM1, which activates multiple pathways, including Piezo channels and the inflammasome, leading to potential downstream changes in contractility and ECM remodeling.NEW & NOTEWORTHY Mechanical forces on the airway can contribute to altered contractility and remodeling in airway diseases, but the mechanisms are not clearly understood. Using human airway smooth muscle cells exposed to cyclic forces with static stretch to mimic breathing and static pressure, we found that the effects of stretch are mediated through STIM1, resulting in the activation of multiple pathways, including Piezo channels and the inflammasome, with potential downstream influences on contractility and remodeling.

Occult Nodal Metastases in Individuals with Clinically Node-Negative Salivary Gland Malignancies.

OBJECTIVES: Salivary gland malignancies comprise a heterogeneous group of pathologies, for which treatment of the clinically negative neck may vary depending on numerous factors. Herein we present data on occult nodal metastases (ONM) as well as survival and recurrence from a large series of cN0 salivary gland malignancies. METHODS: Retrospective chart review was conducted on 532 patients, with 389 patients with major salivary gland cancers and 143 patients with minor salivary gland cancers. Demographic and treatment data were included and rates of ONM, overall survival, local recurrence, regional recurrence, and distant recurrence were analyzed. RESULTS: We found that the overall rate of ONM for parotid was 27% (63/235), for submandibular/sublingual was 35% (18/52), and for minor was 15% (4/26). Analysis of ONM rate at each nodal level was also performed, finding higher rates of level IV and V ONM than prior studies. Submandibular/sublingual and minor salivary gland malignancies showed a predominance of ONMs at levels I-III. Our survival and recurrence rates were similar to those found in previous studies. CONCLUSION: Our data also demonstrate a predominance of ONM in levels I-III for submandibular/sublingual and minor salivary gland cancers, suggesting elective dissection in these levels. LEVEL OF EVIDENCE: 4 Laryngoscope, 134:1705-1715, 2024.

Mechanosensitive Channels in Lung Health and Disease.

The lung is an inherently mechanosensitive organ, where cells of the airway and parenchyma experience a range of mechanical forces throughout life including shear, stretch, and compression, in both health and disease. In this regard, pediatric and adult lung diseases such as wheezing and asthma, bronchopulmonary dysplasia (BPD), chronic obstructive pulmonary disease (COPD), and pulmonary fibrosis (PF) all involve macroscopic and cellular changes to the mechanical properties of the bronchial airways and/or parenchyma to varying extents. Accordingly, understanding how mechanical forces are sensed in the lung, and the responses of cells and tissues in the context of normal development and health versus disease conditions becomes highly relevant. There is increasing recognition that transduction of mechanical forces into cellular responses involves a number of channels, some of which are inherently mechanosensitive. Such channels trigger mechanotransduction pathways that may further mediate cellular remodeling, inflammation, and other pathophysiologic mechanisms in response to stretch, stiffness, and inflammatory cascades. Two particularly important channel families have emerged in pulmonary pathophysiology: the transient receptor potential vanilloid family with focus on member TRPV4 and the recently identified Piezo (PZ) channels. Here, we explore current understanding of the contributions of TRPV4 and PZ channels in lung health and disease states, focusing on the interactions between these mechanosensitive channels and their local environment including immune cells, the extracellular matrix, and cellular cytoskeletal elements. We further discuss potential areas for future research to better understand the impact of mechanical channels on pulmonary health and disease. © 2023 American Physiological Society. Compr Physiol 13:5157-5178, 2023.

Oxygen and mechanical stretch in the developing lung: risk factors for neonatal and pediatric lung disease.

Chronic airway diseases, such as wheezing and asthma, remain significant sources of morbidity and mortality in the pediatric population. This is especially true for preterm infants who are impacted both by immature pulmonary development as well as disproportionate exposure to perinatal insults that may increase the risk of developing airway disease. Chronic pediatric airway disease is characterized by alterations in airway structure (remodeling) and function (increased airway hyperresponsiveness), similar to adult asthma. One of the most common perinatal risk factors for development of airway disease is respiratory support in the form of supplemental oxygen, mechanical ventilation, and/or CPAP. While clinical practice currently seeks to minimize oxygen exposure to decrease the risk of bronchopulmonary dysplasia (BPD), there is mounting evidence that lower levels of oxygen may carry risk for development of chronic airway, rather than alveolar disease. In addition, stretch exposure due to mechanical ventilation or CPAP may also play a role in development of chronic airway disease. Here, we summarize the current knowledge of the impact of perinatal oxygen and mechanical respiratory support on the development of chronic pediatric lung disease, with particular focus on pediatric airway disease. We further highlight mechanisms that could be explored as potential targets for novel therapies in the pediatric population.

Hemiepiphysiodesis for Lower Extremity Coronal Plane Angular Correction in the Distal Femur and Proximal Tibia in Children With Achondroplasia.

BACKGROUND: Achondroplasia is the most prevalent form of skeletal dysplasia, affecting more than 250,000 individuals. Lower extremity angular deformities, particularly genu varum, are common in children with achondroplasia, often resulting in pain and limitation of function. The authors aim to determine the utility of lower extremity growth modulation with hemiepiphysiodesis in children with achondroplasia for correction of coronal plane deformities about the knee. METHODS: The authors performed a retrospective chart review of a single center from 1/1/2000 to 12/31/2020 to identify pediatric patients with achondroplasia treated with hemiepiphysiodesis as their initial procedure at the distal femur and/or proximal tibia. Patients with adequate records and who had completed their treatment were included. Data collected included duration of treatment, complications, need for osteotomy, and radiographic measurements including initial and final mechanical axis deviation, knee mechanical axis zone, mechanical lateral distal femoral angle and medial proximal tibia angle. RESULTS: Ten patients with 17 limbs met our criteria. Nine patients (15 limbs) were treated for genu varum and 1 patient (2 limbs) was treated for genu valgum. Prior to treatment, the mechanical axis fell in zone 3 in 59% of limbs and zone 2 in 41%. Average correction in mechanical axis deviation was 26.1 mm. Average change in mechanical lateral distal femoral angle was 10.3 degrees per limb, and average change in medial proximal tibia angle was 7.1 degrees per limb. Average treatment duration was 909 days. At final follow up, 81% (14/17) of limbs had the mechanical axis in zone 1, with the remaining 18% (3/17) in zone 2. No patient/limb underwent subsequent distal femur or proximal tibia osteotomy for coronal plane alignment. CONCLUSIONS: Children with achondroplasia can successfully be treated with hemiepiphysiodesis to correct coronal plane deformities at the distal femur and proximal tibia. Using this technique, no patient in our series required an osteotomy for genu varum/valgum. LEVEL OF EVIDENCE: Therapeutic level IV, Case series.

Functional α7 nicotinic receptors in human airway smooth muscle increase intracellular calcium concentration and contractility in asthmatics.

Although nicotinic acetylcholine receptors (nAChRs) are commonly associated with neurons in the brain and periphery, recent data indicate that they are also expressed in non-neuronal tissues. We recently found the alpha7 (α7nAChR) subunit is highly expressed in human airway smooth muscle (hASM) with substantial increase in asthmatics, but their functionality remains unknown. We investigated the location and functional role of α7nAChRs in hASM cells from normal versus mild-moderate asthmatic patients. Immunostaining and protein analyses showed α7nAChR in the plasma membrane including in asthmatics. In asthmatic hASM, patch-clamp recordings revealed significantly higher functional homomeric α7nAChR channels. Real-time fluorescence imaging showed nicotine, via α7nAChR, increases intracellular Ca2+ ([Ca2+]i) independent of ACh effects, particularly in asthmatic hASM, while cellular traction force microscopy showed nicotine-induced contractility including in asthmatics. These results indicate functional homomeric and heteromeric nAChRs that are increased in asthmatic hASM, with pharmacology that likely differ owing to different subunit interfaces that form the orthosteric sites. nAChRs may represent a novel target in alleviating airway hyperresponsiveness in asthma.NEW & NOTEWORTHY Cigarette smoking and vaping exacerbate asthma. Understanding the mechanisms of nicotine effects in asthmatic airways is important. This study demonstrates that functional alpha7 nicotinic acetylcholine receptors (α7nAChRs) are expressed in human airway smooth muscle, including from asthmatics, and enhance intracellular calcium and contractility. Although a7nAChRs are associated with neuronal pathways, α7nAChR in smooth muscle suggests inhaled nicotine (e.g., vaping) can directly influence airway contractility. Targeting α7nAChR may represent a novel approach to alleviating airway hyperresponsiveness in asthma.

Utilization of carbonated calcium phosphate cement for contouring cranioplasty in patients with syndromic craniosynostosis.

PURPOSE: Carbonated calcium phosphate (CCP) cement is an alloplastic material which has been increasingly utilized for cranioplasty reconstruction; however, there is a paucity of data investigating its use in patients with syndromic craniosynostosis. The purpose of this study was to characterize our institutional experience with CCP cement for secondary contouring cranioplasty in these patients to establish safety and aesthetic efficacy. METHODS: Patients with syndromic craniosynostosis undergoing cranioplasty with CCP cement from 2009 to 2022 were retrospectively reviewed for prior medical and surgical history, cranioplasty size, cement usage, and postoperative complications. Aesthetic ratings of the forehead region were quantified using the Whitaker scoring system at three timepoints: preoperative (T1), < 6 months postoperative (T2), and > 1 year postoperative (T3). RESULTS: Twenty-one patients were included. Age at surgery was 16.2 ± 2.8 years, forehead cranioplasty area was 135 ± 112 cm2, and mass of cement was 17.2 ± 7.8 g. Patients were followed for 3.0 ± 3.1 years. Whitaker scores decreased from 1.9 ± 0.4 at T1 to 1.4 ± 0.5 at T2 (p = 0.005). Whitaker scores at T2 and T3 were not significantly different (p = 0.720). Two infectious complications (9.5%) were noted, one at 4.5 months postoperatively and the other at 23 months, both requiring operative removal of CCP cement. CONCLUSION: Our results suggest that aesthetic forehead ratings improve after CCP contouring cranioplasty and that the improvement is sustained in medium-term follow-up. Complications were uncommon, suggesting that CCP is relatively safe though longer-term follow-up is needed before reaching definitive conclusions.

Functional neuroanatomy of craving in heroin use disorder: voxel-based meta-analysis of functional magnetic resonance imaging (fMRI) drug cue reactivity studies.

Background: The neuroanatomy of craving, typically investigated using the functional magnetic resonance imaging (fMRI) drug cue reactivity (FDCR) paradigm, has been shown to involve the mesocorticolimbic, nigrostriatal, and corticocerebellar systems in several substances. However, the neuroanatomy of craving in heroin use disorder is still unclear.Objective: The current meta-analysis examines previous research on the neuroanatomy of craving in abstinent individuals with opioid use disorder (OUD).Method: Seven databases were searched for studies comparing abstinent OUD versus healthy controls on drug > neutral contrast interaction at the whole-brain level. Voxel-based meta-analysis was performed using seed-based d mapping with permuted subject images (SDM-PSI). Thresholds were set at a family-wise error rate of less than 5% with the default pre-processing parameters of SDM-PSI.Results: A total of 10 studies were included (296 OUD and 187 controls). Four hyperactivated clusters were identified with Hedges' g of peaks that ranged from 0.51 to 0.82. These peaks and their associated clusters correspond to the three systems identified in the previous literature: a) mesocorticolimbic, b) nigrostriatal, and c) corticocerebellar. There were also newly revealed hyperactivation regions including the bilateral cingulate, precuneus, fusiform gyrus, pons, lingual gyrus, and inferior occipital gyrus. The meta-analysis did not reveal areas of hypoactivation.Conclusion: Recommendations based on the functional neuroanatomical findings of this meta-analysis include pharmacological interventions such as buprenorphine/naloxone and cognitive-behavioral treatments such as cue-exposure combined with HRV biofeedback. In addition, research should utilize FDCR as pre- and post-measurement to determine the effectiveness and mechanism of action of such interventions.

Hearing Outcomes in Failed Newborn Hearing Screening Infants With and Without Chronic Serous Otitis.

OBJECTIVE: To identify outcomes in hearing loss (HL) diagnosis and intervention in infants with a failed newborn hearing screen (NBHS) and otitis media with effusion (OME) compared to those with failed NBHS and without OME. STUDY DESIGN: Retrospective review. SETTING: Tertiary medical center. METHODS: A chart review was performed on infants referred to Primary Children's Hospital for failed NBHS from 2012 to 2018. Eighty infants with failed NBHS and OME and 55 with failed NBHS and no OME were included. Incidence of permanent HL along with the age of HL confirmation and early intervention (EI) enrollment were compared. RESULTS: The incidence of OME in infants with failed NBHS was 59.3%. Fifty-six percent of infants with OME and 12.5% of those without OME did not receive definitive hearing confirmation in either ear due to loss to follow-up or insufficient audiometric assessment. Permanent HL was identified in 11.3% (n = 9) of infants with OME and in 20.0% (n = 11) of those without OME. Infants with OME were significantly older at the time of HL confirmation (4.2 ± 2.1 months) and EI enrollment (5.4 ± 2.5 months) compared to those without OME at the time of HL confirmation (1.0 ± 1.0 months; p < .001) and EI enrollment (2.6 ± 1.8 months; p = .04). CONCLUSION: Infants with failed NBHS and OME are highly susceptible to a significant delay in HL confirmation or lack of confirmatory hearing tests. Timely OME resolution with earlier ventilation tube insertion by 3 months of age and follow-up audiologic assessment is recommended.

Genome Nexus: A Comprehensive Resource for the Annotation and Interpretation of Genomic Variants in Cancer.

PURPOSE: Interpretation of genomic variants in tumor samples still presents a challenge in research and the clinical setting. A major issue is that information for variant interpretation is fragmented across disparate databases, and aggregation of information from these requires building extensive infrastructure. To this end, we have developed Genome Nexus, a one-stop shop for variant annotation with a user-friendly interface for cancer researchers and clinicians. METHODS: Genome Nexus (1) aggregates variant information from sources that are relevant to cancer research and clinical applications, (2) allows high-performance programmatic access to the aggregated data via a unified application programming interface, (3) provides a reference page for individual cancer variants, (4) provides user-friendly tools for annotating variants in patients, and (5) is freely available under an open source license and can be installed in a private cloud or local environment and integrated with local institutional resources. RESULTS: Genome Nexus is available at https://www.genomenexus.org. It displays annotations from more than a dozen resources including those that provide variant effect information (variant effect predictor), protein sequence annotation (Uniprot, Pfam, and dbPTM), functional consequence prediction (Polyphen-2, Mutation Assessor, and SIFT), population prevalences (gnomAD, dbSNP, and ExAC), cancer population prevalences (Cancer hotspots and SignalDB), and clinical actionability (OncoKB, CIViC, and ClinVar). We describe several use cases that demonstrate the utility of Genome Nexus to clinicians, researchers, and bioinformaticians. We cover single-variant annotation, cohort analysis, and programmatic use of the application programming interface. Genome Nexus is unique in providing a user-friendly interface specific to cancer that allows high-performance annotation of any variant including unknown ones. CONCLUSION: Interpretation of cancer genomic variants is improved tremendously by having an integrated resource for annotations. Genome Nexus is freely available under an open source license.

HCC surveillance improves early detection, curative treatment receipt, and survival in patients with cirrhosis: A meta-analysis.

BACKGROUND & AIMS: There is controversy regarding the overall value of hepatocellular carcinoma (HCC) surveillance in patients with cirrhosis given the lack of data from randomized-controlled trials. To address this issue, we conducted a systematic review and meta-analysis of cohort studies evaluating the benefits and harms of HCC surveillance in patients with cirrhosis. METHODS: We performed a search of the Medline and EMBASE databases and national meeting abstracts from January 2014 through July 2020 for studies reporting early-stage HCC detection, curative treatment receipt, or overall survival, stratified by HCC surveillance status, among patients with cirrhosis. Pooled risk ratios (RRs) and hazard ratios, according to HCC surveillance status, were calculated for each outcome using the DerSimonian and Laird method for random effects models. RESULTS: We identified 59 studies including 145,396 patients with HCC, which was detected by surveillance in 41,052 (28.2%) cases. HCC surveillance was associated with improved early-stage detection (RR 1.86, 95% CI 1.73-1.98; I2 = 82%), curative treatment receipt (RR 1.83, 95% CI 1.69-1.97; I2 = 75%), and overall survival (hazard ratio 0.67, 95% CI 0.61-0.72; I2 = 78%) after adjusting for lead-time bias; however, there was notable heterogeneity in all pooled estimates. Four studies examined surveillance-related physical harms due to false positive or indeterminate surveillance results, but no studies examined potential financial or psychological harms. The proportion of patients experiencing surveillance-related physical harms ranged from 8.8% to 27.5% across studies, although most harms were mild in severity. CONCLUSION: HCC surveillance is associated with improved early detection, curative treatment receipt, and survival in patients with cirrhosis, although there was heterogeneity in pooled estimates. Available data suggest HCC surveillance is of high value in patients with cirrhosis, although continued rigorous studies evaluating benefits and harms are still needed. LAY SUMMARY: There has been ongoing debate about the overall value of hepatocellular carcinoma (HCC) screening in patients with cirrhosis given the lack of data from randomized-controlled trials. In a systematic review of contemporary cohort studies, we found that HCC screening is associated with improved early detection, curative treatment receipt, and survival in patients with cirrhosis, although there were fewer data quantifying potential screening-related harms. Available data suggest HCC screening is of high value in patients with cirrhosis, although continued studies evaluating benefits and harms are still needed.

Disparities in Adolescents' Obesogenic Behaviors, 2005-2017.

Objectives: Given the increasing national-level efforts to reduce disparities in obesogenic behaviors in youth, in this paper, we assessed the change in disparities in meeting guidelines for fruits and vegetables intake (FV), physical activity (PA), and sedentary behavior (SB) among adolescents in the United States in the last 13 years. Methods: Using the Youth Risk Behavior Surveillance System (2005-2017), overall and characteristic-specific (sex, age, race/ethnicity) disparities ratios for meeting FV, PA, and SB guidelines were calculated using the Extended Gastwirth Index Method. Linear regressions, one-way analysis of variance, and posthoc tests assessed change in characteristic-specific disparities over the years. Linear and quadratic trends assessed change in characteristic-specific contributions to overall disparities. Results: Sex-specific and age-specific disparities increased for meeting FV and PA and decreased for meeting SB guidelines. Race/ethnicity-specific disparities decreased for meeting FV and SB guidelines. Characteristics-specific contributions to overall disparities for each behavior changed over the years. Conclusions: Disparities in obesogenic behaviors are still an ongoing concern despite national-level efforts to improve adolescents' behaviors. The methodology allowed for meaningful disparities ratios that facilitated comparison of categorical demographic characteristics across the years and identifying targetable intervention groups to reduce disparities.

Trends in Female Authorship in Major Journals of 3 Oncology Disciplines, 2002-2018.

Importance: Gender disparity exists among authors of the oncology literature. Objective: To quantify trends in authorship by gender within a comprehensive data set of Medline-indexed oncology articles in medical journals with high impact factors. Design, Setting, and Participants: This cross-sectional study used Medline citations to examine archives of research journals from 3 disciplines in the oncology literature. Authors from all oncology-related articles with Medical Subject Headings terms assigned from 2002 to 2018 from 13 general oncology/medicine, radiation oncology, and surgical journals were included for analysis, encompassing clinical trials, observational studies (excluding case reports), reviews, systematic reviews, meta-analyses, and all other published articles. Data were analyzed between April and May 2020. Exposures: Authors were assigned genders based on societal naming norms via third-party gender identification service Gender-API.com. This assignment was internally validated based on manually obtained publicly available data on the internet. Main Outcomes and Measures: Trend in female authorship over time while considering journal type, authorship position, and article type. Results: A total of 420 526 authors from 58 368 articles were found, of which 400 945 were assigned a gender based on their name. In total, 29.5% (95% CI, 29.4%-29.6%) of authors were identified as female, rising from 25.5% (95% CI, 24.7%-26.3%) in 2002 to 31.7% (95% CI, 31.2%-32.3%) in 2018. Each subgroup of primary article type by journal type saw a rise in female authorship over the studied period. For primary articles, last authors were less likely to be women than first authors, regardless of journal type, year, and primary article type (eg, general oncology: odds ratio [OR], 0.60; 95% CI, 0.52-0.69). For general oncology articles, women were less likely to be authors of clinical trials at each authorship position than authors at that respective position for observational studies (first, second, and last authors: OR, 0.58; 95% CI, 0.49-0.67; other authors: OR, 0.84; 95% CI, 0.79-0.89). This difference was not seen for radiation oncology or surgical oncology journals. Conclusions and Relevance: This cross-sectional study found that female authorship in oncology research literature has increased. However, there remains a dearth of female senior authors, and the overall rise in female authorship has not kept up with the rise in female oncology faculty.

Utility of Transnasal Humidified Rapid Insufflation Ventilatory Exchange for Microlaryngeal Surgery.

OBJECTIVE: Microlaryngeal surgery typically requires oxygenation and ventilation via either an endotracheal tube (ETT), jet ventilation (JV), or intermittent apnea with an ETT. Transnasal Humidified Rapid Insufflation Ventilatory Exchange (THRIVE) delivered by high flow nasal cannula has been reported as an alternative technique. This method of apneic oxygenation and ventilation allows for stable, unobstructed visualization of immobile laryngeal structures. We aim to describe the technique and characterize intraoperative parameters related to its safety. STUDY DESIGN: Case Series. METHODS: The electronic medical record was reviewed for patients who underwent microlaryngoscopy using THRIVE technique. Patient demographics, procedural details, operative parameters, and anesthesia records were reviewed. Descriptive statistics were reported. RESULTS: A total of 53 patients underwent microlaryngoscopy using THRIVE as the sole method of ventilation, with 62% female. Median age was 51 years, and median BMI was 25 kg/m2 . Most patients were ASA class 2, and most had a Mallampati score of 2. The most common surgical indications were subglottic stenosis, vocal fold lesions, and vocal fold paralysis. Median apnea time was 16 minutes. At the end of case, median end tidal CO2 was 50 mmHg, and median minimum SpO2 was 95. Six cases required supplementation of THRIVE with JV or tracheal intubation for sustained oxygen desaturation. There was an increase in end tidal CO2 of 0.844 mmHg/min of apneic time. CONCLUSIONS: THRIVE is a safe and effective technique for oxygenation and ventilation in microlaryngeal, non-laser surgery in appropriately selected patients. To ensure safety, back-up plans such as jet ventilation and microlaryngeal ETT should be available. LEVEL OF EVIDENCE: 4 Laryngoscope, 131:587-591, 2021.

Striatal network modeling in Huntington's Disease.

Medium spiny neurons (MSNs) comprise over 90% of cells in the striatum. In vivo MSNs display coherent burst firing cell assembly activity patterns, even though isolated MSNs do not burst fire intrinsically. This activity is important for the learning and execution of action sequences and is characteristically dysregulated in Huntington's Disease (HD). However, how dysregulation is caused by the various neural pathologies affecting MSNs in HD is unknown. Previous modeling work using simple cell models has shown that cell assembly activity patterns can emerge as a result of MSN inhibitory network interactions. Here, by directly estimating MSN network model parameters from single unit spiking data, we show that a network composed of much more physiologically detailed MSNs provides an excellent quantitative fit to wild type (WT) mouse spiking data, but only when network parameters are appropriate for the striatum. We find the WT MSN network is situated in a regime close to a transition from stable to strongly fluctuating network dynamics. This regime facilitates the generation of low-dimensional slowly varying coherent activity patterns and confers high sensitivity to variations in cortical driving. By re-estimating the model on HD spiking data we discover network parameter modifications are consistent across three very different types of HD mutant mouse models (YAC128, Q175, R6/2). In striking agreement with the known pathophysiology we find feedforward excitatory drive is reduced in HD compared to WT mice, while recurrent inhibition also shows phenotype dependency. We show that these modifications shift the HD MSN network to a sub-optimal regime where higher dimensional incoherent rapidly fluctuating activity predominates. Our results provide insight into a diverse range of experimental findings in HD, including cognitive and motor symptoms, and may suggest new avenues for treatment.

Multimodal LA-ICP-MS and nanoSIMS imaging enables copper mapping within photoreceptor megamitochondria in a zebrafish model of Menkes disease.

Copper is essential for eukaryotic life, and animals must acquire this nutrient through the diet and distribute it to cells and organelles for proper function of biological targets. Indeed, mutations in the central copper exporter ATP7A contribute to a spectrum of diseases, including Menkes disease, with symptoms ranging from neurodegeneration to lax connective tissue. As such, a better understanding of the fundamental impacts of ATP7A mutations on in vivo copper distributions is of relevance to those affected by these diseases. Here we combine metal imaging and optical imaging techniques at a variety of spatial resolutions to identify tissues and structures with altered copper levels in the Calamitygw71 zebrafish model of Menkes disease. Rapid profiling of tissue slices with LA-ICP-MS identified reduced copper levels in the brain, neuroretina, and liver of Menkes fish compared to control specimens. High resolution nanoSIMS imaging of the neuroretina, combined with electron and confocal microscopies, identified the megamitochondria of photoreceptors as loci of copper accumulation in wildtype fish, with lower levels of megamitochondrial copper observed in Calamitygw71 zebrafish. Interestingly, this localized copper decrease does not result in impaired photoreceptor development or altered megamitochondrial morphology, suggesting the prioritization of copper at sufficient levels for maintaining essential mitochondrial functions. Together, these data establish the Calamitygw71 zebrafish as an optically transparent in vivo model for the study of neural copper misregulation, illuminate a role for the ATP7A copper exporter in trafficking copper to the neuroretina, and highlight the utility of combining multiple imaging techniques for studying metals in whole organism settings with spatial resolution.

Dynamic compressive loading enhances cartilage matrix synthesis and distribution and suppresses hypertrophy in hMSC-laden hyaluronic acid hydrogels.

Mesenchymal stem cells (MSCs) are being recognized as a viable cell source for cartilage repair, and there is growing evidence that mechanical signals play a critical role in the regulation of stem cell chondrogenesis and in cartilage development. In this study we investigated the effect of dynamic compressive loading on chondrogenesis, the production and distribution of cartilage specific matrix, and the hypertrophic differentiation of human MSCs encapsulated in hyaluronic acid (HA) hydrogels during long term culture. After 70 days of culture, dynamic compressive loading increased the mechanical properties, as well as the glycosaminoglycan (GAG) and collagen contents of HA hydrogel constructs in a seeding density dependent manner. The impact of loading on HA hydrogel construct properties was delayed when applied to lower density (20 million MSCs/ml) compared to higher seeding density (60 million MSCs/ml) constructs. Furthermore, loading promoted a more uniform spatial distribution of cartilage matrix in HA hydrogels with both seeding densities, leading to significantly improved mechanical properties as compared to free swelling constructs. Using a previously developed in vitro hypertrophy model, dynamic compressive loading was also shown to significantly reduce the expression of hypertrophic markers by human MSCs and to suppress the degree of calcification in MSC-seeded HA hydrogels. Findings from this study highlight the importance of mechanical loading in stem cell based therapy for cartilage repair in improving neocartilage properties and in potentially maintaining the cartilage phenotype.

RIP1-mediated regulation of lymphocyte survival and death responses.

RIP1 is an adaptor serine/threonine kinase associated with the signaling complex of death receptors (DRs) including Fas, TNFR1, and TRAIL-Rs which can initiate apoptosis. While DRs are dispensable throughout development, RIP1 deletion results in perinatal lethality. The developmental defect caused by absence of RIP1 remains unexplained. In previous studies, RIP1-deficient hematopoietic progenitors failed to reconstitute the T cell compartment and our recent data indicate a new role for RIP1 in TCR-induced activation of the pro-survival NF-κB pathway. Here, we show that RIP1 is also critical for B cell development. In addition, RIP1(-/-) B cells stimulated through LPS/TLR4 are impaired in NF-κB activation but have no major defect in the Akt pathway. Recently, RIP1 has also emerged as a critical player in necrosis-like death, necroptosis, in various cell lines. We have demonstrated that RIP1 deficiency can reverse the embryonic and T cell proliferation defects in mice lacking FADD, a caspase adaptor protein, which indicates a potential role for RIP1 in mediating in vivo necroptosis. We provide an overview and discussion of the accumulating data revealing insights into the diverse functions of RIP1 in survival and death signaling in lymphocytes.