CRISPR-Cas9 knockin mice for genome editing and cancer modeling.

CRISPR-Cas9 is a versatile genome editing technology for studying the functions of genetic elements. To broadly enable the application of Cas9 in vivo, we established a Cre-dependent Cas9 knockin mouse. We demonstrated in vivo as well as ex vivo genome editing using adeno-associated virus (AAV)-, lentivirus-, or particle-mediated delivery of guide RNA in neurons, immune cells, and endothelial cells. Using these mice, we simultaneously modeled the dynamics of KRAS, p53, and LKB1, the top three significantly mutated genes in lung adenocarcinoma. Delivery of a single AAV vector in the lung generated loss-of-function mutations in p53 and Lkb1, as well as homology-directed repair-mediated Kras(G12D) mutations, leading to macroscopic tumors of adenocarcinoma pathology. Together, these results suggest that Cas9 mice empower a wide range of biological and disease modeling applications.

An eosinophil peroxidase activity assay accurately predicts eosinophilic chronic rhinosinusitis.

BACKGROUND: A definitive diagnosis of eosinophilic chronic rhinosinusitis (eCRS) requires invasive surgical tissue sampling and histologic enumeration of intact eosinophils. Eosinophil peroxidase (EPX) is an accurate biomarker of sinonasal tissue eosinophilia in CRS regardless of polyp status. A less invasive and rapid method that accurately identifies tissue eosinophilia would be of great benefit to patients. OBJECTIVE: We sought to evaluate a new clinical tool that uses a nasal swab and colorimetric EPX activity assay to predict a diagnosis of eCRS. METHODS: A prospective, observational cohort study was conducted using nasal swabs and sinonasal tissue biopsies obtained from patients with CRS electing endoscopic sinus surgery. Patients were classified as non-eCRS (n = 19) and eCRS (n = 35) on the basis of pathologically determined eosinophil counts of less than 10 or greater than or equal to 10 eosinophils/HPF, respectively. Swab-deposited EPX activity was measured and compared with tissue eosinophil counts, EPX levels, and CRS-specific disease metrics. RESULTS: EPX activity was significantly increased in patients with eCRS than in patients without eCRS (P < .0001). With a relative absorbance unit cutoff value of greater than or equal to 0.80, the assay demonstrated high sensitivity (85.7%) and moderate specificity (79.0%) for confirming eCRS. Spearman correlations between EPX activity and tissue eosinophil counts (rs = 0.424), EPX levels (rs = 0.503), and Lund-Kennedy endoscopy scores (rs = 0.440) in eCRS were significant (P < .05). CONCLUSIONS: This investigation evaluates a nasal swab sampling method and EPX activity assay that accurately confirms eCRS. This method could potentially address the unmet need to identify sinonasal tissue eosinophilia at the point-of-care, as well as to longitudinally monitor eosinophil activity and treatment response.

Cardiac Magnetic Resonance Fingerprinting: Potential Clinical Applications.

PURPOSE OF REVIEW: Cardiac magnetic resonance fingerprinting (cMRF) has developed as a technique for rapid, multi-parametric tissue property mapping that has potential to both improve cardiac MRI exam efficiency and expand the information captured. In this review, we describe the cMRF technique, summarize technical developments and in vivo reports, and highlight potential clinical applications. RECENT FINDINGS: Technical developments in cMRF continue to progress rapidly, including motion compensated reconstruction, additional tissue property quantification, signal time course analysis, and synthetic LGE image generation. Such technical developments can enable simplified CMR protocols by combining multiple evaluations into a single protocol and reducing the number of breath-held scans. cMRF continues to be reported for use in a range of pathologies; however barriers to clinical implementation remain. Technical developments are described in this review, followed by a focus on potential clinical applications that they may support. Clinical translation of cMRF could shorten protocols, improve CMR accessibility, and provide additional information as compared to conventional cardiac parametric mapping methods. Current needs for clinical implementation are discussed, as well as how those needs may be met in order to bring cMRF from its current research setting to become a viable tool for patient care.

Striatal transcriptome changes linked to drug-induced repetitive behaviors.

Disruptive or excessive repetitive motor patterns (stereotypies) are cardinal symptoms in numerous neuropsychiatric disorders. Stereotypies are also evoked by psychomotor stimulants such as amphetamine. The acquisition of motor sequences is paralleled by changes in activity patterns in the striatum, and stereotypies have been linked to abnormal plasticity in these reinforcement-related circuits. Here, we designed experiments in mice to identify transcriptomic changes that underlie striatal plasticity occurring alongside the development of drug-induced stereotypic behavior. We identified three schedules of amphetamine treatment inducing different degrees of stereotypy and used bulk RNAseq to compare striatal gene expression changes among groups of mice treated with the different drug-dose schedules and vehicle-treated, cage-mate controls. Mice were identified as naïve, sensitized, or tolerant to drug-induced stereotypy. All drug-treated groups exhibited expression changes in genes that encode members of the extracellular signal-regulated kinase (ERK) cascades known to regulate psychomotor stimulant responses. In the sensitized group with the most prolonged stereotypy, we found dysregulation of 20 genes that were not changed in other groups. Gene set enrichment analysis indicated highly significant overlap with genes regulated by neuregulin 1 (Nrg1). Nrg1 is known to be a schizophrenia and autism susceptibility gene that encodes a ligand for Erb-B receptors, which are involved in neuronal migration, myelination, and cell survival, including that of dopamine-containing neurons. Stimulant abuse is a risk factor for schizophrenia onset, and these two disorders share behavioral stereotypy phenotypes. Our results raise the possibility that drug-induced sensitization of the Nrg1 signaling pathway might underlie these links.

Evolving Rhinology: Understanding the Burden of Chronic Rhinosinusitis Today, Tomorrow, and Beyond.

PURPOSE OF REVIEW: To improve our appreciation of the burden of chronic rhinosinusitis (CRS) and to understand better how to ease that burden. RECENT FINDINGS: The burden of CRS is high. At an individual level, this burden is due to rhinologic symptoms as well as more systemic symptoms. At a societal level, the indirect costs of CRS, mostly due to reduced productivity, are higher than the direct costs. Surgical treatment has been found to be effective in addressing both the individual and societal burdens. Endotyping is just beginning to usher in the potential for personalized, precision treatments in CRS. We understand much about the burden of CRS but more remains to be learned, especially as newer expensive treatments become available. By appreciating the high burden of CRS, we can fulfill our mission to effectively lift that burden.

Comparing radiomic classifiers and classifier ensembles for detection of peripheral zone prostate tumors on T2-weighted MRI: a multi-site study.

BACKGROUND: For most computer-aided diagnosis (CAD) problems involving prostate cancer detection via medical imaging data, the choice of classifier has been largely ad hoc, or been motivated by classifier comparison studies that have involved large synthetic datasets. More significantly, it is currently unknown how classifier choices and trends generalize across multiple institutions, due to heterogeneous acquisition and intensity characteristics (especially when considering MR imaging data). In this work, we empirically evaluate and compare a number of different classifiers and classifier ensembles in a multi-site setting, for voxel-wise detection of prostate cancer (PCa) using radiomic texture features derived from high-resolution in vivo T2-weighted (T2w) MRI. METHODS: Twelve different supervised classifier schemes: Quadratic Discriminant Analysis (QDA), Support Vector Machines (SVMs), naïve Bayes, Decision Trees (DTs), and their ensemble variants (bagging, boosting), were compared in terms of classification accuracy as well as execution time. Our study utilized 85 prostate cancer T2w MRI datasets acquired from across 3 different institutions (1 for discovery, 2 for independent validation), from patients who later underwent radical prostatectomy. Surrogate ground truth for disease extent on MRI was established by expert annotation of pre-operative MRI through spatial correlation with corresponding ex vivo whole-mount histology sections. Classifier accuracy in detecting PCa extent on MRI on a per-voxel basis was evaluated via area under the ROC curve. RESULTS: The boosted DT classifier yielded the highest cross-validated AUC (= 0.744) for detecting PCa in the discovery cohort. However, in independent validation, the boosted QDA classifier was identified as the most accurate and robust for voxel-wise detection of PCa extent (AUCs of 0.735, 0.683, 0.768 across the 3 sites). The next most accurate and robust classifier was the single QDA classifier, which also enjoyed the advantage of significantly lower computation times compared to any of the other methods. CONCLUSIONS: Our results therefore suggest that simpler classifiers (such as QDA and its ensemble variants) may be more robust, accurate, and efficient for prostate cancer CAD problems, especially in the context of multi-site validation.

PP2A methylation controls sensitivity and resistance to ß-amyloid-induced cognitive and electrophysiological impairments.

Elevated levels of the ß-amyloid peptide (Aß) are thought to contribute to cognitive and behavioral impairments observed in Alzheimer's disease (AD). Protein phosphatase 2A (PP2A) participates in multiple molecular pathways implicated in AD, and its expression and activity are reduced in postmortem brains of AD patients. PP2A is regulated by protein methylation, and impaired PP2A methylation is thought to contribute to increased AD risk in hyperhomocysteinemic individuals. To examine further the link between PP2A and AD, we generated transgenic mice that overexpress the PP2A methylesterase, protein phosphatase methylesterase-1 (PME-1), or the PP2A methyltransferase, leucine carboxyl methyltransferase-1 (LCMT-1), and examined the sensitivity of these animals to behavioral and electrophysiological impairments caused by exogenous Aß exposure. We found that PME-1 overexpression enhanced these impairments, whereas LCMT-1 overexpression protected against Aß-induced impairments. Neither transgene affected Aß production or the electrophysiological response to low concentrations of Aß, suggesting that these manipulations selectively affect the pathological response to elevated Aß levels. Together these data identify a molecular mechanism linking PP2A to the development of AD-related cognitive impairments that might be therapeutically exploited to target selectively the pathological effects caused by elevated Aß levels in AD patients.

Postnasal drip and chronic cough in patients with chronic rhinitis treated with temperature-controlled radiofrequency neurolysis.

OBJECTIVE: To evaluate the contribution of postnasal drip (PND) and chronic cough (CC) to symptoms of patients with chronic rhinitis treated with temperature-controlled radiofrequency (TCRF) neurolysis of the posterior nasal nerve (PNN), and correlate PND and CC scores with components of the reflective total nasal symptom score (rTNSS). METHODS: Pooled data from three prospective studies: two single-arm studies and the index active treatment arm of a randomized controlled trial. Adult patients with baseline rTNSS ≥6 were treated with TCRF neurolysis at nonoverlapping regions of the PNN. PND and CC symptoms were evaluated on a 0 (none) to 3 (severe) scale. RESULTS: Data from 228 patients (57.9% women, 42.1% men) were included. The mean baseline rTNSS was 8.1 (95% confidence interval [CI], 7.8-8.3), which decreased to 3.2 (95% CI, 2.9-3.5) at 6 months. At baseline, 97.4% of patients had PND and 80.3% had CC. Median baseline PND and CC symptom scores were 3 (interquartile range [IQR], 2-3) and 2 (IQR, 1-2), respectively. At 6 months, this decreased to 1 (IQR, 0-2) and 0 (IQR, 0-1), respectively, showing significant improvement from baseline (both p < 0.001). Spearman correlation coefficients with components of rTNSS (rhinorrhea, congestion, itching, sneezing) were 0.16 to 0.22 for CC and 0.19 to 0.46 for PND, indicating only a weak to moderate correlation. CONCLUSION: PND and CC contribute to the symptomatology of chronic rhinitis and are significantly improved after TCRF neurolysis of the PNN. The inclusion of PND and CC symptoms in a chronic rhinitis assessment instrument could provide important additional information for the characterization of the disease state and outcomes after any therapeutic treatment.

Treatment of unilateral olfactory neuroblastoma: Appropriate extent of surgical resection and potential for olfactory preservation.

Historically, comprehensive surgical resection for olfactory neuroblastoma has included the bilateral olfactory epithelium, cribriform plate, overlying dura, olfactory bulbs and tracts. This results in postoperative anosmia that may significantly impact a patient's quality of life without definitive added benefit in survival. The prevalence of occult intracranial disease is low, especially for Hyams grade I and II tumors. A unilateral approach sparing the contralateral cribriform plate and olfactory system can be considered for select cases of early stage, low-grade tumors when the disease does not cross midline to involve the contralateral olfactory cleft or septal mucosa and when midline dural margins can be cleared with frozen pathology. Approximately half of patients who undergo unilateral resection may have residual olfaction even with adjuvant unilateral radiation. Early data suggest favorable disease-free survival and overall survival for patients who underwent the unilateral approach; however, larger sample studies are needed to confirm comparability to bilateral resections regarding oncologic outcomes.

Patient Questions Surrounding Posterior Nasal Nerve Ablation for Chronic Rhinitis.

Objective: In-office ablation of the posterior nasal nerve (PNN) has emerged as an effective treatment option for chronic rhinitis patients. This study explored questions patients commonly search online regarding this therapy and the quality of content available. Study Design: A retrospective analysis of online search criteria and sources was performed with subsequent analysis of results. Setting: Search and data acquisition was in September of 2023. Methods: Most common search terms related to cryotherapy and radiofrequency neurolysis of the PNN were identified with associated People Also Ask (PAA) questions. Questions were categorized and organized into subtopics and sources evaluated using readability and quality metrics. Results: A total of 255 unique PAA questions and 175 unique websites were identified. The most common subtopics were related to facts about chronic rhinitis (26.7%) and rhinitis treatment options (25.1%). Nearly a quarter (24.3%) of websites were from commercial sources. Quality metrics indicate difficult-to-read and low-quality materials. Conclusion: Existing online resources need improvement to provide patients material that is easier to read. Physicians counseling patients should be aware of these areas for adequate shared decision making.

Features of Importance in Nasal Endoscopy: Deriving a Meaningful Framework.

OBJECTIVE: Critical components of the nasal endoscopic examination have not been definitively established for either the normal examination or for clinical disorders. This study aimed to identify concordance among rhinologists regarding the importance of examination findings for various nasal pathologies. STUDY DESIGN: A consortium of 19 expert rhinologists across the United States was asked to rank the importance of findings on nasal endoscopy for 5 different sinonasal symptom presentations. SETTING: An online questionnaire was distributed in July 2023. METHODS: The questionnaire utilized JotForm® software and featured 5 cases with a set of 4 identical questions per case, each covering a common indication for nasal endoscopy. Rankings were synthesized into Normalized Attention Scores (NASs) and Weighted Normalized Attention Scores (W-NASs) to represent the perceived importance of each feature, scaled from 0 to 1. RESULTS: General concordance was found for examination findings on nasal endoscopy within each case. The perceived features of importance differed between cases based on clinical presentation. For instance, in evaluating postnasal drip, the middle meatus was selected as the most important structure to examine (NAS, 0.73), with mucus selected as the most important abnormal finding (W-NAS, 0.66). The primary feature of interest for mucus was whether it was purulent or not (W-NAS, 0.67). Similar analyses were performed for features in each case. CONCLUSION: The implicit framework existing among rhinologists may help standardize examinations and improve diagnostic accuracy, augment the instruction of trainees, and inform the development of artificially intelligent algorithms to enhance clinical decision-making during nasal endoscopy.

TREATMENT OF HYPOTONY WITH AN INTRAVITREAL GAS BUBBLE.

PURPOSE: To describe a case of successful resolution of severe hypotony and choroidal detachments following nonfiltering glaucoma surgery with an intravitreal injection of C 3 F 8 gas after a poor response to topical steroids and cycloplegia. METHODS: Retrospective chart review of a case report. RESULTS: 89 year-old male presented with a central retinal vein occlusion, hyphema, vitreous hemorrhage and neovascular glaucoma. After initial intravitreal injection of aflibercept he was treated with pars plana vitrectomy with panretinal photocoagulation and endocyclophotocoagulation to the ciliary body, but he continued to have elevated intraocular pressure. Subsequent external cyclophotocoagulation was performed but severe hypotony with inflammation, choroidal detachments, and corneal edema developed one week later without response to cycloplegic and steroid medications. A therapeutic injection of perfluorpropane (C3F8) gas led to resolution of the hypotony and choroid detachment and long-term maintenance of intraocular pressure. DISCUSSION/CONCLUSION: An intravitreal gas bubble can be a very useful outpatient procedure to immediately reverse hypotony, resolve choroidal detachment, and decrease associated inflammation. When hypotony does not respond to medical therapy with cycloplegic drops and steroid medications, then an intravitreal gas bubble can rapidly resolve these complications and result in stabilization of intraocular pressure long-term.

Sex Differences in Airway Diseases.

It is evident that sex and gender differences impact pathophysiology, disease burden, and treatment outcomes for a variety of systems and major illnesses including those affecting the unified airway. Important male-female differences in unified airway disease are driven by various intrinsic and extrinsic mechanisms including anatomic, morphometric, hormonal, genetic (and epigenetic), environmental, psycho-social, and comorbidity-related factors. This review highlights current knowledge of how patient sex influences epidemiology, diagnosis, treatment, and outcomes for diseases affecting the unified airway.

Utility of hospital frailty risk score in predicting postoperative outcomes of sinonasal malignancies.

KEY POINTS: Hospital frailty risk score (HFRS) correlates with complications, length of stay, and non-routine discharge. HFRS is a better predictor of postsurgical sequelae than age and Elixhauser comorbidity index.

Suicidal Behaviors Among Active-Duty US Service Members: Data from the 2018 Health-Related Behaviors Survey.

Background: This study aimed to 1) determine the prevalence of past-year suicidal ideation (SI) and attempts (SA) among active-duty SMs; 2) determine whether differences exist by age, sex, and race; and 3) assess whether prevalence estimates vary by risk profiles of mental health conditions and substance use. Methods: Data were from the 2018 Health-Related Behavior Survey (HRBS), a cross-sectional survey of active-duty SMs (n = 17,166). We used the logistic model to identify the factors of SI and SA and latent class analysis (LCA) to identify the risk profiles. Results: Among active duty SMs, 8.26% had SI and 1.25% had SA in the past year. Gender and age have been shown to influence how race might contribute to suicidal behaviors. Mental health conditions were associated with higher odds of SI and SA, as were younger ages; LGB identity; being separated, divorced, or widowed; use of e-cigarettes, dual use of e-cigarettes and cigarettes, or drugs; and history of deployment of less than 12 months. Frequencies of cigarette and e-cigarette use were also associated with SI and SA, indicating the odds were increasing by 0.3% for every additional cigarette or e-cigarette used. Five risk profiles were identified: class 1 (illegal drug use), class 2 (mental health needs with tobacco and alcohol use), class 3 (mental health conditions only), class 4 ("low risk" SMs with low levels of illegal drug use, mental health visits, tobacco use, and alcohol use), and class 5 (alcohol use). Compared to class 4 ("low risk"), all other risk profiles were associated with increased odds of suicidal behaviors. Conclusion: Despite the resources and increased access provided for mental health support, the prevalence of SI among active-duty SMs is greater than in the general population of the same age, likely due to additional military exposures and stressors.

CalDAG-GEFI down-regulation in the striatum as a neuroprotective change in Huntington's disease.

Huntingtin protein (Htt) is ubiquitously expressed, yet Huntington's disease (HD), a fatal neurologic disorder produced by expansion of an Htt polyglutamine tract, is characterized by neurodegeneration that occurs primarily in the striatum and cerebral cortex. Such discrepancies between sites of expression and pathology occur in multiple neurodegenerative disorders associated with expanded polyglutamine tracts. One possible reason is that disease-modifying factors are tissue-specific. Here, we show that the striatum-enriched protein, CalDAG-GEFI, is severely down-regulated in the striatum of mouse HD models and is down-regulated in HD individuals. In the R6/2 transgenic mouse model of HD, striatal neurons with the largest aggregates of mutant Htt have the lowest levels of CalDAG-GEFI. In a brain-slice explant model of HD, knock-down of CalDAG-GEFI expression rescues striatal neurons from pathology induced by transfection of polyglutamine-expanded Htt exon 1. These findings suggest that the striking down-regulation of CalDAG-GEFI in HD could be a protective mechanism that mitigates Htt-induced degeneration.

Perception of colonoscopy benefits: a gap in patient knowledge?

Our study aimed to determine, for patients who had undergone recent colonoscopy, associations between specific colonoscopy patient characteristics, exam characteristics and patients' perception of colonoscopy reducing their risk of dying from colorectal cancer. A cross-sectional analysis was conducted using data (2004-2008) from the New Hampshire Colonoscopy Registry, consisting of a Self-report Questionnaire, Colonoscopy Report form, and a Follow-up Questionnaire, which measured agreement responses to the statement, "Having a colonoscopy decreased my chances of dying from colon cancer". Chi-square tests and logistic regression were used to assess differences in patient responses by patient and colonoscopy characteristics. A majority of patients (N=5,672, 81%) agreed that having a colonoscopy decreased their chances of dying from colon cancer. Patients with a personal history of polyps were more likely to agree that colonoscopy reduced their chances of dying compared to patients without prior polypectomy [OR (95% CI) =1.34 (1.06, 1.69)] and patients with a family history of colorectal cancer were 33% more likely to agree to the statement than those without a family history [OR (95% CI) =1.33 (1.12, 1.58)]. Personal history of polyps and family history of colorectal cancer are significant predictors of patients' positive perception of colonoscopy, suggesting that personal experience, rather than the potential preventive effect of colonoscopy itself, may influence the perceived benefit of colonoscopy. Intervention efforts should be made to effectively disseminate knowledge of the preventive benefit of colonoscopy.

Sphenoid sinus cholesterol granulomas presenting with abducens nerve palsy.

We discuss two patients who presented with sphenoid sinus cholesterol granulomas and associated unilateral abducens nerve palsies. Two case reports from our institution are reported. A literature review of available articles is presented, discussing both cholesterol granulomas of the sphenoid sinus and sphenoid sinus lesions that present with unilateral abducens palsy. A total of nine cases of sphenoid sinus cholesterol granulomas have been previously reported in the literature. A wide variety of sphenoid sinus pathologies can present with unilateral abducens nerve palsies, however no sphenoid sinus cholesterol granulomas with this presentation were found in the literature. In conclusion, cholesterol granulomas should be included in the differential when a patient presents with an expansile mass of the sphenoid sinus and associated unilateral abducens nerve palsy.

Surgical repair of nasal septal perforations: A systematic review and meta-analysis.

BACKGROUND: A wide variety of techniques for the surgical repair of nasal septal perforations (NSPs) have been described. Surgical management of NSPs can be broadly divided into open versus endonasal approaches, with additional variables involving unilateral or bilateral flaps, use of grafts, and placement of splints. The objective of this study was to compare surgical approaches and their outcomes. METHODS: PubMed, EMBASE, and CINAHL Plus databases were examined for patients undergoing NSP repair. English-language studies reporting surgical management of patients with the primary diagnosis of NSP were included. Outcome measures of interest included perforation size, surgical approach characteristics, and success rate defined as complete closure assessed by surgeon postoperatively. The quality of articles was assessed with the methodological index for nonrandomized studies (MINORS) criteria. A random-effects model was used to calculate pooled proportions for the different outcomes. RESULTS: The electronic database search yielded 1076 abstracts for review. A total of 64 articles met the inclusion criteria, with 1591 patients: 1127 (71%) underwent an endonasal approach and 464 (29%) an open approach. The median (range) MINORS score was 10 (5-12) out of 16 points. Overall, 91% of patients had total closure (95% confidence interval [CI], 0.89-0.93, p < 0.01), with moderate heterogeneity between studies (I2  = 42.03%). There was no difference in closure success between open and endonasal approaches. Use of bilateral versus unilateral flaps, interposition grafts, and intranasal splints and packing were not associated with differences in outcomes. CONCLUSION: Nasal septal perforation surgical repair success rates are comparable regardless of technique.