Development and characterization of a preclinical mouse model of alkali-induced limbal stem cell deficiency.

PURPOSE: Limbal stem cell deficiency (LSCD) secondary to ocular surface alkali burn is a blinding condition that features corneal conjunctivalization. Mechanistic insights into its pathophysiology are lacking. Here, we developed a mouse model that recapitulates human disease to comprehensively delineate the clinicopathological features of a conjunctivalized cornea. METHODS: LSCD was induced in the right eyes of 6-8-week-old C57BL/6 male and female mice (n = 151) by topical administration of 0.25N sodium hydroxide on the cornea. Uninjured left eyes served as controls. Clinical, histological, phenotypic, molecular, and immunological assessments were performed at multiple time-points over 6-months. RESULTS: Clinically, alkali burn caused persistent corneal opacity (p = 0.0014), increased punctate staining (p = 0.0002), and reduced epithelial thickness (p = 0.0082) compared to controls. Total LSCD was confirmed in corneal whole mounts by loss of K12 protein (p < 0.0001) and mRNA expression (p = 0.0090). Instead, K8+, K13+, K15+ and MUC5AC+ conjunctival epithelia prevailed. 20 % of injured corneas developed islands of K12+ epithelia, suggesting epithelial transdifferentiation. Squamous metaplasia was detected in 50 % of injured corneas. Goblet cell density peaked early post-injury but decreased over time (p = 0.0047). Intraepithelial corneal basal nerve density remained reduced even at 6-months post-injury (p = 0.0487). CONCLUSIONS: We developed and comprehensively characterized a preclinical mouse model of alkali-induced LSCD. Understanding the pathophysiological processes that transpire on the ocular surface in LSCD is key to discovering, testing, and advancing biological and pharmacological interventions that can be dispensed prior to or in conjunction with stem cell therapy to rehabilitate the cornea and restore vision.

Multimodal Retinal Imaging Classification for Parkinson's Disease Using a Convolutional Neural Network.

Purpose: Changes in retinal structure and microvasculature are connected to parallel changes in the brain. Two recent studies described machine learning algorithms trained on retinal images and quantitative data that identified Alzheimer's dementia and mild cognitive impairment with high accuracy. Prior studies also demonstrated retinal differences in individuals with PD. Herein, we developed a convolutional neural network (CNN) to classify multimodal retinal imaging from either a Parkinson's disease (PD) or control group. Methods: We trained a CNN to receive retinal image inputs of optical coherence tomography (OCT) ganglion cell-inner plexiform layer (GC-IPL) thickness color maps, OCT angiography 6 × 6-mm en face macular images of the superficial capillary plexus, and ultra-widefield (UWF) fundus color and autofluorescence photographs to classify the retinal imaging as PD or control. The model consists of a shared pretrained VGG19 feature extractor and image-specific feature transformations which converge to a single output. Model results were assessed using receiver operating characteristic (ROC) curves and bootstrapped 95% confidence intervals for area under the ROC curve (AUC) values. Results: In total, 371 eyes of 249 control subjects and 75 eyes of 52 PD subjects were used for training, validation, and testing. Our best CNN variant achieved an AUC of 0.918. UWF color photographs were the most effective imaging input, and GC-IPL thickness maps were the least contributory. Conclusions: Using retinal images, our pilot CNN was able to identify individuals with PD and serves as a proof of concept to spur the collection of larger imaging datasets needed for clinical-grade algorithms. Translational Relevance: Developing machine learning models for automated detection of Parkinson's disease from retinal imaging could lead to earlier and more widespread diagnoses.

Impact of Cannabis Use on Immune Cell Populations and the Viral Reservoir in People With HIV on Suppressive Antiretroviral Therapy.

BACKGROUND: Human immunodeficiency virus (HIV) infection remains incurable due to the persistence of a viral reservoir despite antiretroviral therapy (ART). Cannabis (CB) use is prevalent amongst people with HIV (PWH), but the impact of CB on the latent HIV reservoir has not been investigated. METHODS: Peripheral blood cells from a cohort of PWH who use CB and a matched cohort of PWH who do not use CB on ART were evaluated for expression of maturation/activation markers, HIV-specific T-cell responses, and intact proviral DNA. RESULTS: CB use was associated with increased abundance of naive T cells, reduced effector T cells, and reduced expression of activation markers. CB use was also associated with reduced levels of exhausted and senescent T cells compared to nonusing controls. HIV-specific T-cell responses were unaffected by CB use. CB use was not associated with intact or total HIV DNA frequency in CD4 T cells. CONCLUSIONS: This analysis is consistent with the hypothesis that CB use reduces activation, exhaustion, and senescence in the T cells of PWH, and does not impair HIV-specific CD8 T-cell responses. Longitudinal and interventional studies with evaluation of CB exposure are needed to fully evaluate the impact of CB use on the HIV reservoir.

Frequent first-trimester pregnancy loss in rhesus macaques infected with African-lineage Zika virus.

In the 2016 Zika virus (ZIKV) pandemic, a previously unrecognized risk of birth defects surfaced in babies whose mothers were infected with Asian-lineage ZIKV during pregnancy. Less is known about the impacts of gestational African-lineage ZIKV infections. Given high human immunodeficiency virus (HIV) burdens in regions where African-lineage ZIKV circulates, we evaluated whether pregnant rhesus macaques infected with simian immunodeficiency virus (SIV) have a higher risk of African-lineage ZIKV-associated birth defects. Remarkably, in both SIV+ and SIV- animals, ZIKV infection early in the first trimester caused a high incidence (78%) of spontaneous pregnancy loss within 20 days. These findings suggest a significant risk for early pregnancy loss associated with African-lineage ZIKV infection and provide the first consistent ZIKV-associated phenotype in macaques for testing medical countermeasures.

Type 2 diabetes influences intraepithelial corneal nerve parameters and corneal stromal-epithelial nerve penetration sites.

INTRODUCTION: The quantification of intraepithelial corneal basal nerve parameters by in vivo confocal microscopy represents a promising modality to identify the earliest manifestations of diabetic peripheral neuropathy. However, its diagnostic accuracy is hampered by its dependence on neuron length, with minimal consideration for other parameters, including the origin of these nerves, the corneal stromal-epithelial nerve penetration sites. This study sought to utilize high-resolution images of murine corneal nerves to analyze comprehensively the morphological changes associated with type 2 diabetes progression. MATERIALS AND METHODS: ßIII-Tubulin immunostained corneas from prediabetic and type 2 diabetic mice and their respective controls were imaged by scanning confocal microscopy and analyzed automatically for nerve parameters. Additionally, the number and distribution of penetration sites was manually ascertained and the average length of the axons exiting them was computed. RESULTS: The earliest detectable changes included a significant increase in nerve density (6.06 ± 0.41% vs 8.98 ± 1.99%, P = 0.03) and branching (2867.8 ± 271.3/mm2 vs 4912.1 ± 1475.3/mm2 , P = 0.03), and in the number of penetration sites (258.80 ± 20.87 vs 422.60 ± 63.76, P = 0.0002) at 8 weeks of age. At 16 weeks, corneal innervation decreased, most notably in the periphery. The number of penetration sites remained significantly elevated relative to controls throughout the monitoring period. Similarly, prediabetic mice exhibited an increased number of penetration sites (242.2 ± 13.55 vs 305.6 ± 30.96, P = 0.003) without significant changes to the nerves. CONCLUSIONS: Our data suggest that diabetic peripheral neuropathy may be preceded by a phase of neuron growth rather than regression, and that the peripheral cornea is more sensitive than the center for detecting changes in innervation.

Artificial intelligence in dementia.

PURPOSE OF REVIEW: Artificial intelligence tools are being rapidly integrated into clinical environments and may soon be incorporated into dementia diagnostic paradigms. A comprehensive review of emerging trends will allow physicians and other healthcare providers to better anticipate and understand these powerful tools. RECENT FINDINGS: Machine learning models that utilize cerebral biomarkers are demonstrably effective for dementia identification and prediction; however, cerebral biomarkers are relatively expensive and not widely available. As eye images harbor several ophthalmic biomarkers that mirror the state of the brain and can be clinically observed with routine imaging, eye-based machine learning models are an emerging area, with efficacy comparable with cerebral-based machine learning models. Emerging machine learning architectures like recurrent, convolutional, and partially pretrained neural networks have proven to be promising frontiers for feature extraction and classification with ocular biomarkers. SUMMARY: Machine learning models that can accurately distinguish those with symptomatic Alzheimer's dementia from those with mild cognitive impairment and normal cognition as well as predict progressive disease using relatively inexpensive and accessible ocular imaging inputs are impactful tools for the diagnosis and risk stratification of Alzheimer's dementia continuum. If these machine learning models can be incorporated into clinical care, they may simplify diagnostic efforts. Recent advancements in ocular-based machine learning efforts are promising steps forward.

Gluten-free diet adherence and implications for the diagnosis of coeliac disease.

Coeliac disease (CD) is an autoimmune disorder caused by the ingestion of gluten containing foods in genetically susceptible individuals, with a worldwide prevalence of up to 1%. Currently, the only available treatment is a gluten-free diet (GFD). Screening for CD is primarily performed using serum based testing for anti-tissue transglutaminase (tTG) antibodies. Patients must be on a gluten containing diet at the time of testing to ensure an accurate serological result. We investigated the prevalence of a GFD in hospital clinic settings and the general population using survey data to estimate the proportion of CD patients that may be misdiagnosed for CD based on serological tests. Data were collected at clinics of a metropolitan hospital in Sydney, Australia, and the general population. Data from Medicare Benefits Scheme and tTG results from a large Australian private laboratory were reviewed for comparison. Of 778 participants who responded to the survey, 58 (7.5%) were on a GFD. More patients attending the immunology (15.9%) and gastroenterology (12.1%) clinics adopted a GFD than those attending the diabetes (2.6%) or endocrinology (6.1%) clinics, or in the general population (4.3%). More females than males excluded gluten from their diet (p<0.0001). Medicare statistics between 2013 and 2019 demonstrated an increase in CD serological testing; however, tTG data from a private pathology highlighted a stable level of elevated tTG antibodies of 3% of total tests performed. The high number of individuals on a GFD is likely impacting the ability to accurately diagnose CD using serum-based testing.

Use of High-Refractive Index Hydrogels and Tissue Clearing for Large Biological Sample Imaging.

Recent advances in tissue clearing and light sheet fluorescence microscopy have improved insights into and understanding of tissue morphology and disease pathology by imaging large samples without the requirement of histological sectioning. However, sample handling and conservation of sample integrity during lengthy staining and acquisition protocols remains a challenge. This study overcomes these challenges with acrylamide hydrogels synthesised to match the refractive index of solutions typically utilised in aqueous tissue clearing protocols. These hydrogels have a high-water content (82.0 ± 3.7% by weight). The gels are stable over time and FITC-IgG readily permeated into and effluxed out of them. Whilst the gels deformed and/or swelled over time in some commonly used solutions, this was overcome by using a previously described custom refractive index matched solution. To validate their use, CUBIC cleared mouse tissues and whole embryos were embedded in hydrogels, stained using fluorescent small molecule dyes, labels and antibodies and successfully imaged using light sheet fluorescence microscopy. In conclusion, the high water content, high refractive index hydrogels described in this study have broad applicability to research that delves into pathophysiological processes by stabilising and protecting large and fragile samples.

Outcomes of patients with refractory out-of-hospital cardiac arrest transported to an ECMO centre compared with transport to non-ECMO centres.

Objective: To compare the outcomes of patients with refractory out-of-hospital cardiac arrest (OHCA) transported to a hospital that provides extracorporeal membrane oxygenation (ECMO) during cardiopulmonary resuscitation (ECPR) with patients transported to hospitals without ECPR capability. Design, setting: Retrospective review of patient care records in a pre-hospital and hospital setting. Participants: Adult patients with OHCA who left the scene and arrived with cardiopulmonary resuscitation in progress at 16 hospitals in Melbourne, Australia, between January 2016 and December 2019. Intervention: For selected patients transported to the ECPR centre, initiation of ECMO. Main outcome measures: Survival to hospital discharge and 12-month quality of life. Results: There were 223 eligible patients during the study period. Of 49 patients transported to the ECPR centre, 23 were commenced on ECMO. Of these, survival to hospital with good neurological recovery (Cerebral Performance Category [CPC] score 1/2) occurred in 4/23 patients. Four other patients developed return of spontaneous circulation in the ECPR centre before cannulation of whom one survived, giving overall good functional outcome at 12 months survival of 5/49 (10.2%). There were 174 patients transported to the 15 non-ECPR centres and 3/174 (2%) had good functional outcome at 12 months. After adjustment for baseline differences, the odds ratio for good neurological outcome after transport to an ECPR centre compared with a non-ECPR centre was 4.63 (95% CI, 0.97-22.11; P = 0.055). Conclusion: The survival rate of patients with refractory OHCA transported to an ECPR centre remains low. Outcomes in larger cities might be improved with shorter scene times and additional ECPR centres that would provide for earlier initiation of ECMO.

The Multiple Object Avoidance (MOA) task measures attention for action: Evidence from driving and sport.

Performance in everyday tasks, such as driving and sport, requires allocation of attention to task-relevant information and the ability to inhibit task-irrelevant information. Yet there are individual differences in this attentional function ability. This research investigates a novel task for measuring attention for action, called the Multiple Object Avoidance task (MOA), in its relation to the everyday tasks of driving and sport. The aim in Study 1 was to explore the efficacy of the MOA task to predict simulated driving behaviour and hazard perception. Whilst also investigating its test-retest reliability and how it correlates to self-report driving measures. We found that superior performance in the MOA task predicted simulated driving performance in complex environments and was superior at predicting performance compared to the Useful Field of View task. We found a moderate test-retest reliability and a correlation between the attentional lapses subscale of the Driving Behaviour Questionnaire. Study 2 investigated the discriminative power of the MOA in sport by exploring performance differences in those that do and do not play sports. We also investigated if the MOA shared attentional elements with other measures of visual attention commonly attributed to sporting expertise: Multiple Object Tracking (MOT) and cognitive processing speed. We found that those that played sports exhibited superior MOA performance and found a positive relationship between MOA performance and Multiple Object Tracking performance and cognitive processing speed. Collectively, this research highlights the utility of the MOA when investigating visual attention in everyday contexts.

Fast and Accurate Ophthalmic Medication Bottle Identification Using Deep Learning on a Smartphone Device.

PURPOSE: To assess the accuracy and efficacy of deep learning models, specifically convolutional neural networks (CNNs), to identify glaucoma medication bottles. DESIGN: Algorithm development for predicting ophthalmic medication bottles using a large mobile image-based dataset. PARTICIPANTS: A total of 3750 mobile images of 5 ophthalmic medication bottles were included: brimonidine tartrate, dorzolamide-timolol, latanoprost, prednisolone acetate, and moxifloxacin. METHODS: Seven CNN models were initially pretrained on a large-scale image database and subsequently retrained to classify 5 commonly prescribed topical ophthalmic medications using a training dataset of 2250 mobile-phone captured images. The retrained CNN models' accuracies were compared using k-fold cross-validation (k = 10). The top 2 performing CNN models were then embedded into separate iOS apps and evaluated using 1500 mobile images not included in the training dataset. MAIN OUTCOME MEASURES: Prediction accuracy, image processing time. RESULTS: Of the 7 CNN architectures, MobileNet v2 yielded the highest k-fold cross-validation accuracy of 0.974 (95% confidence interval [CI], 0.966-0.980) and the shortest average image processing time at 3.45 (95% CI, 3.13-3.77) sec/image. ResNet V2 had the second highest accuracy of 0.961 (95% CI, 0.952-0.969). When the 2 app-embedded CNNs were compared, in terms of accuracy, MobileNet V2, with an image prediction accuracy of 0.86 (95% CI, 0.84-0.88), was significantly greater than ResNet V2, 0.68 (95% CI, 0.66-0.71) (Table 1). Sensitivities and specificities varied between medications (Table 1). There was no significant difference in average imaging processing time, 0.32 (95% CI, 0.28-0.36) sec/image and 0.31 (95% CI, 0.29-0.33) sec/image for MobileNet V2 and ResNet V2, respectively. Information on beta-testing of the iOS app can be found here: https://lin.hs.uci.edu/research/. CONCLUSIONS: We have retrained MobileNet V2 to accurately identify ophthalmic medication bottles and demonstrated that this neural network can operate in a smartphone environment. This work serves as a proof-of-concept for the production of a CNN-based smartphone application to empower patients by decreasing risk for error.

Increased Shoulder Distraction Force and Shoulder Horizontal Abduction in Professional Baseball Pitchers With Discordant Torso Rotation Order.

BACKGROUND: Inefficient energy transfer from the pelvis and trunk has been shown to increase compensation at the level of the shoulder. Kinetic chain sequencing of the core segments is underexamined in professional baseball pitchers, especially as it relates to changes in upper extremity kinetics. PURPOSE: To evaluate elbow and shoulder kinetics in a cohort of professional pitchers differentiated by instances of discordant pelvic to upper torso sequencing during the pitch. STUDY DESIGN: Descriptive laboratory study. METHODS: 285 professional baseball pitchers were evaluated using 3D motion capture (480 Hz). Pitchers were divided into "chronological" and "discordant" groups based on whether maximum pelvic rotation velocity occurred before (chronological) or after (discordant) maximum upper torso rotation velocity during the pitch motion. Pelvic, upper torso, and shoulder kinematic parameters, shoulder distraction force, shoulder internal rotation torque, and pitch efficiency (PE) were compared between groups. RESULTS: Pitchers with discordant torso sequencing (n = 30; 110 pitches) had greater shoulder horizontal adduction at maximum external rotation (mean difference, 3.6°; 95% CI, -5.2° to -2.0°; t = -4.5; P < .001) and greater maximum shoulder external rotation (mean difference, 3.7°; 95% CI, 5.7° to 1.5°; t = -3.5; P < .001) than chronological pitchers (n = 255; 2974 pitches). PE did not differ between groups (P = .856), whereas ball velocity was significantly faster in the discordant group (mean difference, 0.6 m/s; 95% CI, -1.1 to -0.3 m/s; t = -3.3; P = .0012). Chronological pitchers had significantly reduced shoulder distraction force (mean difference, -4.7% body weight (BW); 95% CI, -7.9% to -1.5% BW; t = -2.9; P = .004) with no difference in shoulder internal rotation torque (P = .160). These kinematic and kinetic differences were not observed when accounting for interpitcher variability. CONCLUSION: Between pitchers, those who had a discordant pelvic to upper torso sequence experienced significantly greater shoulder distraction forces, potentially compensating by increasing maximum shoulder external rotation and horizontal abduction. Achieving maximal pelvic rotation velocity before maximal rotation velocity may be advantageous in preventing compensation at the upper extremity and excessive throwing arm loading. CLINICAL RELEVANCE: Identifying risk factors for increased upper extremity forces has potential implications in injury prevention. Specifically, mitigating shoulder distraction forces may be beneficial in reducing risk of injury.

Nuclear Leukocyte Immunoglobulin-like Receptor A3 Is Monomeric and Is Involved in Multiple Layers of Regulated Gene Expression and Translation.

The leukocyte immunoglobulin-like receptor A3 (LILRA3) is a soluble protein primarily expressed by peripheral blood monocytes and is abundant in sera of healthy donors. Extracellular LILRA3 is anti-inflammatory and displays neuro-regenerative functions in vitro. However, its intracellular expression, distribution, and function(s) remain unknown. Using a combination of high-resolution confocal and super-resolution microscopy, we identified intracellular expression of native LILRA3 in the nucleus of peripheral blood monocytes and in vitro-derived macrophages. This unexpected nuclear localization of LILRA3 was confirmed in LILRA3-GFP-transfected HEK293T cells. Western blot of proteins fractionated from primary macrophages and the transfected HEK293T cells confirmed nuclear localization of the native and expressed LILRA3 proteins. Interestingly, most of the LILRA3 in the nucleus was in a monomeric form like the biologically active secreted protein, while that in the other cellular compartments was in mixed monomeric, dimeric, and oligomeric forms. The predominant presence of monomeric LILRA3 in the nucleus was independently corroborated in transfected live HEK293T cells using the number and molecular brightness (N&B) analysis method. Immunoprecipitation and mass spectrometric peptide sequencing studies revealed that nuclear LILRA3 co-immunoprecipitated with several nuclear proteins involved in host protein synthesis machinery via direct interactions to a key multifunctional RNA-binding protein, the Ewing sarcoma breakpoint region 1 protein (EWS) (data are available via ProteomeXchange with identifier PXD024602). The biological significance of the nuclear expression of LILRA3 and its interaction with these key proteins remain to be elucidated.

Cerebrospinal fluid free light chain quantitation is a specific biomarker for inflammatory neurological disorders in a paediatric patient cohort.

The analysis of cerebrospinal fluid (CSF) is routinely used in the diagnostic work-up of a range of inflammatory, infective, and congenital neurological conditions. Many diagnostic tests used in this analysis have poor sensitivity; as such, we investigated the utility of CSF free light chain (FLC) analysis as an adjunct to currently used assays in a paediatric population with neurological disorders. Kappa (κ) and lambda (λ) FLC levels were quantitated in blinded CSF samples by two nephelometric platforms. Results were correlated to clinical diagnoses and classified according to inflammatory/infective or non-inflammatory pathogenesis. FLC results were also compared to currently used CSF diagnostic tests including oligoclonal bands (OCB), CSF IgG and albumin levels, and differential cell count. Of 70 samples analysed, 29 (41%) had an inflammatory or infective diagnosis and 41 (59%) presented with a range of non-inflammatory aetiologies. Thirteen patients had elevated κFLC or λFLC as detected on the IMMAGE 800, defined as greater than the detection limit of the assay (0.600 mg/L for CSF κFLC, and 0.490 mg/L for CSF λFLC), and of these 12 (92%) had an inflammatory disease (sensitivity 41.4%, specificity 97.6%). On the BN II using optimal cut-offs of 0.27 mg/L and 0.12 mg/L for CSF κFLC and λFLC respectively, 24 (34%) patients had elevated results, of which 21 (88%) had an inflammatory disease (sensitivity 72.4%, specificity 92.7%). Analysis of FLC correlated better with diagnostic classification of the diseases than OCB, cell counts and CSF IgG levels. The results of this study support the use of CSF FLC analysis in the diagnosis of paediatric neuroinflammatory conditions.

Neuronal-epithelial cell alignment: A determinant of health and disease status of the cornea.

PURPOSE: How sensory neurons and epithelial cells interact with one another, and whether this association can be considered an indicator of health or disease is yet to be elucidated. METHODS: Herein, we used the cornea, Confetti mice, a novel image segmentation algorithm for intraepithelial corneal nerves which was compared to and validated against several other analytical platforms, and three mouse models to delineate this paradigm. For aging, eyes were collected from 2 to 52 week-old normal C57BL/6 mice (n ≥ 4/time-point). For wound-healing and limbal stem cell deficiency, 7 week-old mice received a limbal-sparing or limbal-to-limbal epithelial debridement to their right cornea, respectively. Eyes were collected 2-16 weeks post-injury (n=4/group/time-point), corneas procured, immunolabelled with ßIII-tubulin, flat-mounted, imaged by scanning confocal microscopy and analyzed for nerve and epithelial-specific parameters. RESULTS: Our data indicate that nerve features are dynamic during aging and their curvilinear arrangement align with corneal epithelial migratory tracks. Moderate corneal injury prompted axonal regeneration and recovery of nerve fiber features. Limbal stem cell deficient corneas displayed abnormal nerve morphology, and fibers no longer aligned with corneal epithelial migratory tracks. Mechanistically, we discovered that nerve pattern restoration relies on the number and distribution of stromal-epithelial nerve penetration sites. CONCLUSIONS: Microstructural changes to innervation may explain corneal complications related to aging and/or disease and facilitate development of new assays for diagnosis and/or classification of ocular and systemic diseases.

The Relationship Between the Functional Gait Assessment and Quality-of-Life Data in Patients Undergoing Vestibular Schwannoma Resection.

OBJECTIVE: To examine the relationship between the Functional Gait Assessment (FGA) and quality of life (QOL) measurements relating to balance before and after vestibular schwannoma (VS) resection and to assess the role of preoperative FGA in predicting postoperative QOL. STUDY DESIGN: A prospective clinical study of adult patients undergoing VS resection between September 2018 and December 2019. FGA was administered 1 week before and after surgery. Dizziness Handicap Inventory (DHI) and Penn Acoustic Neuroma Quality of Life (PANQOL) were administered preoperatively and at 3 months postoperatively. SETTING: Single tertiary center. PATIENTS: Patients (age ≥ 18 years old) with VS undergoing microsurgical resection. Excluded were patient with previous surgery or radiation. INTERVENTION: VS resection. MAIN OUTCOMES AND MEASURES: Primary outcome: correlation between FGA and QOL surveys. Secondary outcome: correlation between preoperative measurements of balance and postoperative PANQOL. RESULTS: One hundred thirty-eight patients were analyzed (mean age: 48 years old, 65.9% female). The translabyrinthine approach was most commonly performed. Under multivariate analysis, preoperative FGA significantly correlated with preoperative PANQOL balance score (p < 0.0001), preoperative PANQOL total score (p = 0.0002), and preoperative DHI (p < 0.0001). However, postoperative FGA did not significantly correlate with postoperative PANQOL balance or total scores (p = 0.446 and p = 0.4, respectively), or postoperative DHI (p = 0.3). Univariate analysis demonstrated that preoperative DHI and preoperative FGA were predictive of changes in postoperative PANQOL balance and total scores. However under multivariate analysis, preoperative FGA did not predict changes in postoperative PANQOL balance or total score (p = 0.24; p = 0.28, respectively). Preoperative DHI remained predictive of changes in postoperative PANQOL balance (p = 0.03) score but not of postoperative PANQOL total score (p = 0.37). CONCLUSIONS: Although FGA and QOL data significantly correlated in the preoperative setting, our results did not suggest that preoperative FGA can be used to determine postoperative QOL. Additionally, the lack of correlation between FGA and QOL measurements in the acute postoperative setting suggests that further research is needed to determine contributors to postoperative QOL.

Extracorporeal Cardiopulmonary Resuscitation in Adults. Interim Guideline Consensus Statement From the Extracorporeal Life Support Organization.

DISCLAIMER: Veno-arterial extracorporeal membrane oxygenation (ECMO) is increasingly being deployed for selected patients in cardiac arrest who do not attain a native circulation with conventional CPR (ECPR). This ELSO guideline is intended to be a practical guide to implementing ECPR and the early management following establishment of ECMO support. Where a paucity of high-quality evidence exists, a consensus has been reached amongst the authors to provide guidance to the clinician. This guideline will be updated as further evidence in this field becomes available.

Correction to: CT angiograms of the neck in strangulation victims: incidence of positive findings at a level one trauma center over a 7-year period.

The original source of the flowchart in Fig. 3 has not been referenced and acknowledged correctly in the original article. This is now corrected.

Dose-dependent benzalkonium chloride toxicity imparts ocular surface epithelial changes with features of dry eye disease.

PURPOSE: Inclusion of the preservative benzalkonium chloride (BAC) in ophthalmic solutions is prevalent, despite the noted potential for exacerbating dry eye disease (DED). Whilst studies incorporating BAC have assessed its' effects as a mouse model of DED, the impact on limbal epithelia is under-studied. Our investigation aimed to comprehensively assess the impact of different BAC dosing regimens and their suitability as a mouse model of DED. METHODS: C57BL/6J mice (n = 72) were administered topical BAC (0.05-0.2%) over 7 days. Fluorescein staining, corneal smoothness index, and immuno-histological analyses were applied to determine architectural and cellular changes on the ocular surface following BAC treatment. The effect of BAC (0.0001-0.01%) on cultivated primary mouse corneo-limbal epithelial cells (CLECs) (n = 6) was examined using morphological and functional assays. RESULTS: Whilst 0.2% BAC induced severe corneal epithelial defects, 0.1% BAC dispensed once daily over 7 days, induced punctate fluorescein staining without detriment to corneal smoothness. Histochemical staining revealed disorganized basal corneal epithelial cells with enlarged cytoplasmic halos. Furthermore, PAS+ goblet cells were decreased. BAC treatment also modulated K14 expression and distribution within the limbus. In cultured CLEC, BAC triggered cell contraction and vacuolation, increased LDH release and elevated cell necrosis by 4.1-fold. Concentrations of BAC as low as 0.0001% decreased colony formation. CONCLUSIONS: This study describes how exposing C57BL/6 mice to BAC induce some clinicopathological features of DED seen in humans, and therefore provides the foundations to explore the consequences on the ocular surface, particularly on limbal epithelia and its' stem cells.

Peripheral (not central) corneal epithelia contribute to the closure of an annular debridement injury.

Corneal epithelia have limited self-renewal and therefore reparative capacity. They are continuously replaced by transient amplifying cells which spawn from stem cells and migrate from the periphery. Because this view has recently been challenged, our goal was to resolve the conflict by giving mice annular injuries in different locations within the corneolimbal epithelium, then spatiotemporally fate-mapping cell behavior during healing. Under these conditions, elevated proliferation was observed in the periphery but not the center, and wounds predominantly resolved by centripetally migrating limbal epithelia. After wound closure, the central corneal epithelium was completely replaced by K14+ limbal-derived clones, an observation supported by high-resolution fluorescence imaging of genetically marked cells in organ-cultured corneas and via computational modeling. These results solidify the essential role of K14+ limbal epithelial stem cells for wound healing and refute the notion that stem cells exist within the central cornea and that their progeny have the capacity to migrate centrifugally.