Multidisciplinary Advanced Surgical Planning for Slide Tracheoplasty Using 3D-Printed Models.

OBJECTIVE: The objective of this study was to develop and assess multidisciplinary advanced surgical planning (ASP) sessions using three dimensional (3D) printed models for cervicothoracic slide tracheoplasty (CST). We hypothesized that these sessions would improve surgeon confidence, streamline intraoperative planning, and highlight the utility of 3D modeling. METHODS: 3D-printed patient-specific trachea models were used in pre-operative ASP sessions consisting of a multidisciplinary case discussion and hands-on slide tracheoplasty simulation. Participants completed a survey rating realism, utility, impact on the final surgical plan, and pre- and post-session confidence. Statistical analysis was performed via Wilcoxon and Kruskal-Wallis tests. RESULTS: Forty-eight surveys were collected across nine sessions and 27 different physicians. On a 5-point Likert scale, models were rated as "very realistic", "very useful" (both median of 4, IQR 3-4 and 4-5, respectively). Overall confidence increased by 1.4 points (+/- 0.7, p < 0.0001), with the largest change seen in those with minimal prior slide tracheoplasty experience (p = 0.005). Participants felt that the sessions "strongly" impacted their surgical plan or anticipated performance (median 4, IQR 4-5), regardless of training level or experience. CONCLUSION: 3D-printed patient-specific models were successfully implemented in ASP sessions for CST. Models were deemed very realistic and very useful by surgeons across multiple specialties and training levels. Surgical planning sessions also strongly impacted the final surgical plan and increased surgeon confidence for CST. LEVEL OF EVIDENCE: IV Laryngoscope, 2024.

Identification of Optimal Tissue-Marking Dye Color for Pathological Evaluation in Fluorescence Imaging Using IRDye800CW.

PURPOSE: Fluorescence-guided surgery using a tumor-specific antibody-dye conjugate is useful in various cancer types. Fluorescence imaging is a valuable tool both intraoperatively and postoperatively for ex vivo imaging. The color of inks used for tumor specimens during ex vivo specimen processing in pathology is an important consideration for fluorescence imaging since the absorption/emission of the dyes may interfere with the fluorescent dye. This study assesses suitable ink colors for use specifically with IRDye800CW fluorescence imaging. PROCEDURES: Eight tissue-marking inks or dyes (TMDs) commonly used for pathological evaluation were assessed. Agarose tissue-mimicking phantoms containing Panitumumab-IRDye800CW were used as an initial model. Mean fluorescence intensity was measured at 800 nm using both Pearl Trilogy as a closed-field fluorescence imaging system and pde-neo II as an open-field fluorescence imaging system before and after TMD application. An in vivo mouse xenograft model using the human head and neck squamous cell carcinoma FaDu cell line was then used in conjunction with TMDs. RESULTS: The retained IRDye800CW fluorescence on Pearl Trilogy was as follows: yellow at 91.0 ± 4.5%, red at 90.6 ± 2.7%, orange at 88.2 ± 2.2%, violet at 56.6 ± 1.1%, lime at 40.9 ± 1.8%, green at 19.3 ± 2.8%, black at 13.3 ± 0.6%, and blue at 8.1 ± 0.2%. The retained IRDye800CW fluorescence on pde-neo II was as follows: yellow at 86.5 ± 6.4%, red at 77.0 ± 6.2%, orange at 76.9 ± 2.8%, lime at 72.5 ± 9.5%, violet at 59.7 ± 0.4%, green at 30.1 ± 6.9%, black at 17.0 ± 2.7%, and blue at 6.7 ± 1.7%. The retained IRDye800CW fluorescence in yellow and blue TMDs was 42.1 ± 14.9% and 0.2 ± 0.2%, respectively in the mouse experiment (p = 0.039). CONCLUSION: Yellow, red, and orange TMDs should be used, and blue and black TMDs should be avoided for evaluating tumor specimens through fluorescence imaging using IRDye800CW.

Whole transcriptome-based skin virome profiling in typical epidermodysplasia verruciformis reveals α-, ß-, and γ-HPV infections.

HPVs are DNA viruses include approximately 450 types that are classified into 5 genera (α-, ß-, γ-, µ-, and ν-HPV). The γ- and ß-HPVs are present in low copy numbers in healthy individuals; however, in patients with an inborn error of immunity, certain species of ß-HPVs can cause epidermodysplasia verruciformis (EV), manifesting as recalcitrant cutaneous warts and skin cancer. EV presents as either typical or atypical. Manifestations of typical EV are limited to the skin and are caused by abnormal keratinocyte-intrinsic immunity to ß-HPVs due to pathogenic sequence variants in TMC6, TMC8, or CIB1. We applied a transcriptome-based computational pipeline, VirPy, to RNA extracted from normal-appearing skin and wart samples of patients with typical EV to explore the viral and human genetic determinants. In 26 patients, 9 distinct biallelic mutations were detected in TMC6, TMC8, and CIB1, 7 of which are previously unreported to our knowledge. Additionally, 20 different HPV species, including 3 α-HPVs, 16 ß-HPVs, and 1 γ-HPV, were detected, 8 of which are reported here for the first time to our knowledge in patients with EV (ß-HPV-37, -47, -80, -151, and -159; α-HPV-2 and -57; and γ-HPV-128). This study expands the TMC6, TMC8, and CIB1 sequence variant spectrum and implicates new HPV subtypes in the pathogenesis of typical EV.

A Validated 3D Printed Laryngeal Suturing Simulator for Endoscopic Laryngeal Cleft Repair.

OBJECTIVES: Endoscopic laryngeal cleft repair (ELCR) with endolaryngeal suturing is an advanced surgical skill. This study objective was to assess the validity of 3-dimensionally (3D) printed laryngeal suturing simulator for ELCR. STUDY DESIGN: Development and validation of a simulator for ELCR. METHODS: An ELCR model was developed using 3D printed and readily available materials. Participants were surveyed before and after a simulation session using five-point Likert scale questions. Performance data was assessed using blinded expert video review and rated using a novel objective structured assessment of technical skills (OSATS) for endoscopic laryngeal suturing. RESULTS: Twenty-one participants ranging from residents to attendings completed the simulation session. Survey respondents reported on a five-point Likert scale that the model was "easy to use" and "quite realistic" (both mean of 4). Confidence improved significantly in 86% of participants (p < 0.01). Overall OSATS scores (out of a total of 55) showed a median improvement in technical skills of 11.7 points (p = 0.004). OSATS demonstrated good intra-rater (κ = 0.689 and 0.677) and moderate inter-rater (κ = 0.573) reliability. Completion times improved from the first to the last suture by a median time of 512 to 350 s (decrease of 202 s, p = 0.002). Participants with no prior ELCR experience improved more than those with in vivo experience. CONCLUSION: This study demonstrates the validity of a simulator utilizing 3D printed larynges for ELCR. A novel OSATS for endoscopic laryngeal suturing was successfully implemented. Confidence, technical skills, and completion times improved with the use of the model across a variety of participants. Laryngoscope, 133:785-791, 2023.

Inherited ichthyosis as a paradigm of rare skin disorders: Genomic medicine, pathogenesis, and management.

Great advances have been made in the field of heritable skin disorders using next-generation sequencing (NGS) technologies (ie, whole-genome sequencing, whole-exome sequencing, whole-transcriptome sequencing, and disease-targeted multigene panels). When NGS first became available, the cost and lack of access to these technologies were limiting factors; however, with decreasing sequencing costs and the expanding knowledge base of genetic skin diseases, fundamental awareness of NGS has become prudent. The heritable ichthyoses comprise a genotypically and phenotypically heterogeneous group of monogenic keratinization disorders characterized by persistent scaling, with at least 55 distinct genes currently implicated in causing nonsyndromic and syndromic forms of the disease. By providing a simplified overview of available NGS techniques and applying them in the context of ichthyosis, one of the most common genodermatoses, we hope to encourage dermatologists to offer, when appropriate, genetic testing earlier in patients with unsolved presentations. With the aid of NGS, dermatologists can provide diagnostic certainty in cases of suspected genodermatoses and offer potentially life-changing genome-guided and targeted therapies as they become available.

Beyond Laryngeal Clefts: Interarytenoid Injection Augmentation to Predict Success of Suture Augmentation in Children.

OBJECTIVE: To assess the efficacy of interarytenoid injection augmentation (IAIA) and the ability of IAIA to predict response to interarytenoid suture augmentation (IASA) based on diet advancement on video fluoroscopic swallow studies (VFSS). METHODS: Retrospective cohort analysis of patients with persistent pharyngeal dysphagia at a tertiary children's hospital with VFSS pre- and post-IAIA were included between March 2011 and June 2019. RESULTS: Median age of the 229 patients was 2.2 years (5.8 months-19 years). Interarytenoid mucosal height (IAMH) was found to be above the false vocal folds in 112 patients (53.4%) and at true vocal folds in 10 (4.9%) patients. On VFSS post-IAIA, 95 (41.5%) patients were successfully advanced in recommended diet consistency, 115 (50.2%) were stable, and 19 (8.3%) needed thicker consistency. Paired t-tests on pre- and post-operative consistency scores showed significant improvement, p-value of <0.0001, 95% confidence interval (CI; 0.50-0.85). Poisson regression found no covariates with significant association with improvement on IAIA. For IASA patients, 35/60 (58.3%) improved on post-op VFSS. Paired t-tests on pre- and post-operative consistency scores showed significant improvement, p-value of <0.0001, 95% CI (0.63-1.33). Positive predictive value for IAIA predicting response to IASA was 77% with positive likelihood ratio of 2.3. The response to IAIA versus no response to IAIA likelihood ratios were found to have a statistically significant difference (p < 0.05). CONCLUSIONS: Our study suggests IAIA yields objective improvement in swallow function on VFSS in nearly half of our patients and may be a reliable diagnostic tool to predict response to IASA in patients with persistent pharyngeal dysphagia with or without a laryngeal cleft. LEVEL OF EVIDENCE: 3 Laryngoscope, 133:1749-1756, 2023.

Acquired ichthyosis, asteatotic dermatitis or xerosis? An update on pathoetiology and drug-induced associations.

Acquired ichthyosis (AI) is a relatively rare cutaneous entity characterized by transient, generalized scaling and pruritus in the absence of family history of ichthyosis or atopic disease. The hyperkeratosis in AI can range from the mild, white-to-brown scaling resembling that in ichthyosis vulgaris (IV) to the more prominent dark brown scaling phenotype, similar to that found in lamellar ichthyosis. The disease can wax and wane in relation to endogenous and/or exogenous factors. Histopathology of AI is similar to that found in IV. AI is usually of cosmetic concern to patients but can, in some cases, reflect the presence of more serious conditions, including malignancies, autoimmune diseases or metabolic disorders. In some cases, AI can be an adverse effect of a medication or the cutaneous symptom of a toxic exposure. Other conditions, such as severe xerosis or eczema, can present with clinical findings similar to AI, making diagnosis a challenge. Furthermore, cases of AI are sporadic throughout the literature and have been documented across a wide variety of medical settings distinct from dermatology, which often contribute to misdiagnosis of this disease. Definitive management requires prompt identification and treatment of the inciting factors combined with conservative therapies, which can include topical emollients, keratolytics, retinoids or corticosteroids, and in rare cases, oral retinoids.

Linear Immunoglobulin A (IgA) Bullous Dermatosis Mimicking Stevens-Johnson Syndrome.

Linear IgA bullous dermatosis (LABD) is a rare autoimmune blistering disease characterized by linear IgA deposition along the dermo-epidermal junction on direct immunofluorescence (DIF). LABD appears clinically as erythematous polycyclic lesions in younger patients but can show considerable phenotypic heterogeneity in older patients, often leading to misdiagnoses such as bullous pemphigoid, pemphigus vulgaris, Stevens-Johnson syndrome/toxic epidermal necrolysis (SJS/TEN), or other bullous conditions. Cases of LABD mimicking SJS/TEN require prompt skin biopsies for histopathology and DIF for disease differentiation and medical decision-making. In cases of suspected drug-induced LABD or SJS/TEN, identification and removal of the offending agent are paramount. The preferred treatment for LABD is oral dapsone, while SJS/TEN may respond better to cyclosporine or a combination of intravenous immunoglobulin and systemic corticosteroids. This case highlights the rare occurrence of LABD mimicking SJS/TEN and emphasizes the details that clinicians must know to guide patient management.

Ichthyosis follicularis syndromes in patients with mutations in GJB2.

Ichthyosis follicularis (IF) manifests as generalized spiny follicular projections found in syndromic diseases secondary to SREBF1 and MBTPS2 mutations. We sought the genetic cause of IF in two distinct families from a cohort of 180 patients with ichthyosis. In Family 1, the proband (Patient 1) presented with IF, bilateral sensorineural hearing loss and punctate palmoplantar keratoderma. Using DNA from peripheral blood lymphocytes, two compound heterozygous mutations, c.526A>G and c.35delG, were discovered in GJB2. In Family 2, the proband (Patient 2) presented with a previously unreported IF phenotype in the context of keratitis-ichthyosis-deafness syndrome, and whole-exome sequencing found a de novo heterozygous mutation, c.148G>A in GJB2. Histopathology was consistent with porokeratotic eccrine ostial and dermal duct naevus (PEODDN) and IF in Patients 1 and 2, respectively. Our findings add to the clinical and histopathological spectrum of IF and emphasize the association of PEODDN-like entities with GJB2 variants.

Aquatic Antagonists: Jellyfish Stings.

Jellies, more commonly known as jellyfish, are a common cause of stings in oceans throughout the world. Most stings result in immediate painful skin reactions that can be treated with hot water immersion and careful removal of adherent tentacles. Rarely, certain jellyfish species can cause life-threatening systemic reactions that must be treated promptly and monitored in the acute care setting. Wearing a full-body stinger suit or applying a sting-inhibiting lotion are common strategies that may reduce the risk for jellyfish injuries. Avoidance of waters during jellyfish season is prudent in regions that harbor more dangerous species of jellyfish, particularly along the Australian and Indo-Pacific coastlines.

Comparison of Slide Tracheoplasty Technique on Postoperative Anatomic Outcomes in Three-Dimensional Printed Models.

OBJECTIVES/HYPOTHESIS: We hypothesized that the use of three-dimensional (3D) printed tracheal models to reproducibly simulate surgical technique variations in slide tracheoplasty would demonstrate the quantitative impact of surgical variables on postoperative tracheal dimensions. STUDY DESIGN: Prospective analysis of three-dimensional printed surgical simulation models. METHODS: Slide tracheoplasty was performed on 3D printed long segment tracheal stenosis models with combinations of tracheal transection incision angle (90°, 45° beveled superior to inferior, 45° beveled inferior to superior) and tracheal transection location relative to the stenosis (at midpoint, 2 mm each superior and inferior to midpoint). Postoperative computed tomography (CT) scans measured changes in tracheal length, volume, and cross-sectional area compared to controls. Statistical analysis was performed using one-way analysis of variance and unpaired two-tailed t-tests. RESULTS: Slide tracheoplasty yielded 27 reconstructed tracheas. On average, slide tracheoplasty reduced total tracheal length by 36%. Beveled tracheal incisions yielded 9.5% longer final tracheas than straight transection incisions (P < .0001). Cross-sectional area at the stenosis midpoint increased from 9.0 mm2 to 45 mm2 but did not vary with technique (P > .05). Total tracheal luminal volume increased from 900 mm3 to 1378 mm3 overall and was largest with beveled incisions (P = .03). More material was discarded with straight incisions compared to beveled (89 mg vs. 19 mg, P < .0001). CONCLUSIONS: Beveled tracheal transection incisions resulted in increased tracheal length, longer anastomotic segments, increased volume, and reduced tissue waste as compared to straight incisions. Offsetting the incision from the midpoint of stenosis did not significantly affect reconstructed tracheal morphology. Using 3D printed models for surgical simulation can be helpful for the quantitative study of the effect isolated surgical variables on technical outcomes. LEVEL OF EVIDENCE: 3 Laryngoscope, 132:1306-1312, 2022.

A single-cell atlas and lineage analysis of the adult Drosophila ovary.

The Drosophila ovary is a widely used model for germ cell and somatic tissue biology. Here we use single-cell RNA-sequencing (scRNA-seq) to build a comprehensive cell atlas of the adult Drosophila ovary that contains transcriptional profiles for every major cell type in the ovary, including the germline stem cells and their niche cells, follicle stem cells, and previously undescribed subpopulations of escort cells. In addition, we identify Gal4 lines with specific expression patterns and perform lineage tracing of subpopulations of escort cells and follicle cells. We discover that a distinct subpopulation of escort cells is able to convert to follicle stem cells in response to starvation or upon genetic manipulation, including knockdown of escargot, or overactivation of mTor or Toll signalling.

Development of clinical care guidelines for faculty and residents in the era of COVID-19.

BACKGROUND: The global COVID-19 pandemic brings new challenges to otolaryngology resident education. Surgical volume and clinic visits are curtailed, personal protective equipment for operating room participation is restricted, and the risk of COVID-19 disease transmission during heretofore routine patient care is the new norm. METHODS: We describe a small-team "cohorting" protocol including guidelines for faculty and resident in common clinical scenarios with attention paid to the risk of common otolaryngologic procedures. RESULTS: A rotating small-team approach was implemented at each clinical site, limiting interaction between department members but providing comprehensive coverage. Faculty were involved at the earliest phase of clinical interactions. Guidelines delineated faculty and resident roles based on risk stratification by patient COVID status and anticipated procedures. Special consideration was given to high-risk procedures such as endoscopy and tracheotomy. CONCLUSIONS: A small-team-based approach with guidelines for faculty/resident roles may mitigate risk while optimizing patient care and maximizing education.

Impact of Primary Language and Insurance on Pediatric Hearing Health Care in a Multidisciplinary Clinic.

Objective This study aims to describe the effects of primary language and insurance status on care utilization among deaf or hard-of-hearing children under active otolaryngologic and audiologic care. Study Design Cross-sectional analysis. Setting Multidisciplinary hearing loss clinic at a tertiary center. Subjects and Methods Demographics, hearing loss data, and validated survey responses were collected from 206 patients aged 0 to 19 years. Two-sided t tests and χ2 tests were used to obtain descriptive statistics and hypothesis testing. Results Of the sample, 52.4% spoke primarily English at home. Non-English-speaking children and families were less likely to receive psychiatric counseling (12.2% vs 35.2% in the English group, P < .001) and reported more difficulty obtaining educational interventions ( P = .016), and 68.9% had public insurance. Parents of publicly insured children were less likely to know the type or degree of their child's hearing loss (56.9% vs 75.4%, P = .022), and these children were older on presentation to the clinic (8.5 vs 6.5 years of age, P = .01) compared to privately insured children. Publicly insured children were less likely to receive cochlear implants ( P = .046) and reported increased difficulty obtaining hearing aids ( P = .047). While all patients reported impairment in hearing-related quality of life, publicly insured children aged 2 to 7 years were more likely to perform below minimum thresholds on measures of auditory/oral functioning. Conclusion Even when under active care, deaf or hard-of-hearing children from families who do not speak English at home or with public insurance face more difficulty obtaining educational services, cochlear implants, and hearing aids. These findings represent significant disparities in access to necessary interventions.

Sinonasal Quality of Life in Children With Cystic Fibrosis.

IMPORTANCE: Sinusitis is the most common otolaryngologic complaint in children with cystic fibrosis (CF). However, basic knowledge about the effect of sinusitis on these children is lacking. OBJECTIVE: To evaluate the incidence and quality-of-life impact of chronic rhinosinusitis (CRS) in an unbiased cohort of children with CF. DESIGN, SETTING, AND PARTICIPANTS: Survey study of consecutive pediatric patients with CF presenting for routine quarterly evaluation at a tertiary CF clinic at an academic pediatric hospital. Surveys were completed during the period from December 2012 to January 2013. MAIN OUTCOMES AND MEASURES: Surveys designed to assess major criteria for diagnosis of CRS and a validated pediatric sinonasal quality-of-life instrument, the Sinonasal-5 (SN-5). Statistical analysis was performed to evaluate association between demographic features and survey responses. RESULTS: Of the 102 consecutive eligible patients, 47 children (46%) aged 2 to 20 years (mean [SD] age, 12.9 [5.6] years; 24 [51%] female) completed the surveys. Depending on the exact diagnostic criteria used, 5 (11%) to 18 (38%) of children with CF had CRS. Mean domain (2.16; 95% CI, 2.02-2.30) and overall visual-analog scale (8.26; 95% CI, 8.01-8.51) scores on the SN-5 were consistent with minimal effect on quality of life and comparable to historical posttreatment scores. Mean scores on nasal obstruction (3.07; 95% CI, 2.80-3.34) and sinusitis (2.68;; 95% CI, 2.42-2.94) were the most affected domains, whereas allergy (1.83; 95% CI, 1.65-2.01), emotional disturbance (1.76; 95% CI, 1.56-1.96), and activity restriction (1.43; 95% CI, 1.31-1.57) were minimally affected. Children with a diagnosis of CRS had higher mean SN-5 scores (2.60; 95% CI, 2.31-2.89 vs 2.05; 95% CI, 1.90-2.20; difference of 0.55; 95% CI, 0.29-0.80). Twenty-five patients (53%) had undergone some treatment for sinusitis. There was no association between SN-5 score and CRS treatment history. CONCLUSIONS AND RELEVANCE: In this study, the incidence of symptomatic CRS was high, but quality-of-life impact was relatively low among children with CF. Use of standardized assessment scales, including consensus diagnostic criteria and validated quality-of-life surveys, may be helpful to guide referral and management decisions.

Precision Tumor Recognition by T Cells With Combinatorial Antigen-Sensing Circuits.

T cells can be re-directed to kill cancer cells using chimeric antigen receptors (CARs) or T cell receptors (TCRs). This approach, however, is constrained by the rarity of tumor-specific single antigens. Targeting antigens also found on bystander tissues can cause life-threatening adverse effects. A powerful way to enhance ON-target activity of therapeutic T cells is to engineer them to require combinatorial antigens. Here, we engineer a combinatorially activated T cell circuit in which a synthetic Notch receptor for one antigen induces the expression of a CAR for a second antigen. These dual-receptor AND-gate T cells are only armed and activated in the presence of dual antigen tumor cells. These T cells show precise therapeutic discrimination in vivo-sparing single antigen "bystander" tumors while efficiently clearing combinatorial antigen "disease" tumors. This type of precision dual-receptor circuit opens the door to immune recognition of a wider range of tumors. VIDEO ABSTRACT.

Synthetic control of mammalian-cell motility by engineering chemotaxis to an orthogonal bioinert chemical signal.

Directed migration of diverse cell types plays a critical role in biological processes ranging from development and morphogenesis to immune response, wound healing, and regeneration. However, techniques to direct, manipulate, and study cell migration in vitro and in vivo in a specific and facile manner are currently limited. We conceived of a strategy to achieve direct control over cell migration to arbitrary user-defined locations, independent of native chemotaxis receptors. Here, we show that genetic modification of cells with an engineered G protein-coupled receptor allows us to redirect their migration to a bioinert drug-like small molecule, clozapine-N-oxide (CNO). The engineered receptor and small-molecule ligand form an orthogonal pair: The receptor does not respond to native ligands, and the inert drug does not bind to native cells. CNO-responsive migration can be engineered into a variety of cell types, including neutrophils, T lymphocytes, keratinocytes, and endothelial cells. The engineered cells migrate up a gradient of the drug CNO and transmigrate through endothelial monolayers. Finally, we demonstrate that T lymphocytes modified with the engineered receptor can specifically migrate in vivo to CNO-releasing beads implanted in a live mouse. This technology provides a generalizable genetic tool to systematically perturb and control cell migration both in vitro and in vivo. In the future, this type of migration control could be a valuable module for engineering therapeutic cellular devices.

Actin dynamics rapidly reset chemoattractant receptor sensitivity following adaptation in neutrophils.

Neutrophils are cells of the innate immune system that hunt and kill pathogens using directed migration. This process, known as chemotaxis, requires the regulation of actin polymerization downstream of chemoattractant receptors. Reciprocal interactions between actin and intracellular signals are thought to underlie many of the sophisticated signal processing capabilities of the chemotactic cascade including adaptation, amplification and long-range inhibition. However, with existing tools, it has been difficult to discern actin's role in these processes. Most studies investigating the role of the actin cytoskeleton have primarily relied on actin-depolymerizing agents, which not only block new actin polymerization but also destroy the existing cytoskeleton. We recently developed a combination of pharmacological inhibitors that stabilizes the existing actin cytoskeleton by inhibiting actin polymerization, depolymerization and myosin-based rearrangements; we refer to these processes collectively as actin dynamics. Here, we investigated how actin dynamics influence multiple signalling responses (PI3K lipid products, calcium and Pak phosphorylation) following acute agonist addition or during desensitization. We find that stabilized actin polymer extends the period of receptor desensitization following agonist binding and that actin dynamics rapidly reset receptors from this desensitized state. Spatial differences in actin dynamics may underlie front/back differences in agonist sensitivity in neutrophils.

A robust method to derive functional neural crest cells from human pluripotent stem cells.

Neural crest (NC) cells contribute to the development of many complex tissues of all three germ layers during embryogenesis, and its abnormal development accounts for several congenital birth defects. Generating NC cells-including specific subpopulations such as cranial, cardiac, and trunk NC cells-from human pluripotent stem cells will provide a valuable model system to study human development and disease. Here, we describe a rapid and robust NC differentiation method called "LSB-short" that is based on dual SMAD pathway inhibition. This protocol yields high percentages of NC cell populations from multiple human induced pluripotent stem and human embryonic stem cell lines in 8 days. The resulting cells can be propagated easily, retain NC marker expression over multiple passages, and can spontaneously differentiate into several NC-derived cell lineages, including smooth muscle cells, peripheral neurons, and Schwann cells. NC cells generated by this method represent cranial, cardiac and trunk NC subpopulations based on global gene expression analyses, are similar to in vivo analogues, and express a common set of NC alternative isoforms. Functionally, they are also able to migrate appropriately in response to chemoattractants such as SDF-1, FGF8b, and Wnt3a. By yielding NC cells that likely represent all NC subpopulations in a shorter time frame than other published methods, our LSB-short method provides an ideal model system for further studies of human NC development and disease.