The Role of Extracellular Vesicles in Allergic Sensitization: A Systematic Review.

Allergies affect approximately 10-30% of people worldwide, with an increasing number of cases each year; however, the underlying mechanisms are still poorly understood. In recent years, extracellular vesicles (EVs) have been suggested to play a role in allergic sensitization and skew to a T helper type 2 (Th2) response. The aim of this review is to highlight the existing evidence of EV involvement in allergies. A total of 22 studies were reviewed; 12 studies showed EVs can influence a Th2 response, while 10 studies found EVs promoted a Th1 or Treg response. EVs can drive allergic sensitization through up-regulation of pro-Th2 cytokines, such as IL-4 and IL-13. In addition, EVs from MRSA can induce IgE hypersensitivity in mice towards MRSA. On the other hand, EVs can induce tolerance in the immune system; for example, pre-exposing OVA-loaded EVs prevented OVA sensitization in mice. The current literature thus suggests that EVs play an essential role in allergy. Further research utilizing human in vitro models and clinical studies is needed to give a reliable account of the role of EVs in allergy.

Extracellular DNA traps in a ctenophore demonstrate immune cell behaviors in a non-bilaterian.

The formation of extracellular DNA traps (ETosis) is a first response mechanism by specific immune cells following exposure to microbes. Initially characterized in vertebrate neutrophils, cells capable of ETosis have been discovered recently in diverse non-vertebrate taxa. To assess the conservation of ETosis between evolutionarily distant non-vertebrate phyla, we observed and quantified ETosis using the model ctenophore Mnemiopsis leidyi and the oyster Crassostrea gigas. Here we report that ctenophores - thought to have diverged very early from the metazoan stem lineage - possess immune-like cells capable of phagocytosis and ETosis. We demonstrate that both Mnemiopsis and Crassostrea immune cells undergo ETosis after exposure to diverse microbes and chemical agents that stimulate ion flux. We thus propose that ETosis is an evolutionarily conserved metazoan defense against pathogens.

ACR Appropriateness Criteria® Sudden Onset of Cold, Painful Leg: 2023 Update.

Acute onset of a cold, painful leg, also known as acute limb ischemia, describes the sudden loss of perfusion to the lower extremity and carries significant risk of morbidity and mortality. Acute limb ischemia requires rapid identification and the management of suspected vascular compromise and is inherently driven by clinical considerations. The objectives of initial imaging include confirmation of diagnosis, identifying the location and extent of vascular occlusion, and preprocedural/presurgical planning. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision process support the systematic analysis of the medical literature from peer reviewed journals. Established methodology principles such as Grading of Recommendations Assessment, Development, and Evaluation or GRADE are adapted to evaluate the evidence. The RAND/UCLA Appropriateness Method User Manual provides the methodology to determine the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where peer reviewed literature is lacking or equivocal, experts may be the primary evidentiary source available to formulate a recommendation.

Phylogenetic and Protein Structure Analyses Provide Insight into the Evolution and Diversification of the CD36 Domain "Apex" among Scavenger Receptor Class B Proteins across Eukarya.

The cluster of differentiation 36 (CD36) domain defines the characteristic ectodomain associated with class B scavenger receptor (SR-B) proteins. In bilaterians, SR-Bs play critical roles in diverse biological processes including innate immunity functions such as pathogen recognition and apoptotic cell clearance, as well as metabolic sensing associated with fatty acid uptake and cholesterol transport. Although previous studies suggest this protein family is ancient, SR-B diversity across Eukarya has not been robustly characterized. We analyzed SR-B homologs identified from the genomes and transcriptomes of 165 diverse eukaryotic species. The presence of highly conserved amino acid motifs across major eukaryotic supergroups supports the presence of a SR-B homolog in the last eukaryotic common ancestor. Our comparative analyses of SR-B protein structure identify the retention of a canonical asymmetric beta barrel tertiary structure within the CD36 ectodomain across Eukarya. We also identify multiple instances of independent lineage-specific sequence expansions in the apex region of the CD36 ectodomain-a region functionally associated with ligand-sensing. We hypothesize that a combination of both sequence expansion and structural variation in the CD36 apex region may reflect the evolution of SR-B ligand-sensing specificity between diverse eukaryotic clades.

Deep learning analysis of blood flow sounds to detect arteriovenous fistula stenosis.

For hemodialysis patients, arteriovenous fistula (AVF) patency determines whether adequate hemofiltration can be achieved, and directly influences clinical outcomes. Here, we report the development and performance of a deep learning model for automated AVF stenosis screening based on the sound of AVF blood flow using supervised learning with data validated by ultrasound. We demonstrate the importance of contextualizing the sound with location metadata as the characteristics of the blood flow sound varies significantly along the AVF. We found the best model to be a vision transformer trained on spectrogram images. Our model can screen for stenosis at a performance level comparable to that of a nephrologist performing a physical exam, but with the advantage of being automated and scalable. In a high-volume, resource-limited clinical setting, automated AVF stenosis screening can help ensure patient safety via early detection of at-risk vascular access, streamline the dialysis workflow, and serve as a patient-facing tool to allow for at-home, self-screening.

Depression and thoughts of self-harm and suicide among people living with dementia: results of a cross-sectional survey.

BACKGROUND: Depression is common among people with dementia. Despite most people with dementia living in the community, there have been few investigations of self-reported depressive symptoms and suicidal ideation among community-dwelling people with dementia in Australia. This study aimed to explore the proportion of people with mild, moderate and severe levels of depressive symptoms, and suicidal ideation among a sample of people living with dementia in Australia. Correlates of reporting depressive symptoms were also explored. METHODS: Adults diagnosed with dementia by a medical professional who were English speaking and community-dwelling were asked to complete a paper and pencil survey. Those who were unable to provide independent consent were excluded. Depression was assessed using the Geriatric Depression Scale -15, and suicidal ideation was assessed using two study-specific items. Multivariable analyses examined quality of life, unmet needs and sociodemographic factors associated with having a score of five or more on the Geriatric Depression Scale-15. RESULTS: Ninety-four people participated in the study. Thirty-seven percent (n = 35) reported some level of depressive symptoms, with most of these (21%, n = 20) classified as having mild depressive symptoms. Five participants (5%) reported they had had thoughts of being better off dead or hurting themselves, while three (3%) reported having had a plan to end their life. For each additional unmet need, the odds of being depressed increased by 25%(P < 0.001). For each point increase in quality of life, the odds of being depressed decreased by 48% (P < 0.001). CONCLUSIONS: The high proportion of people with dementia who report depressive symptoms suggests the need to routinely assess depressive symptoms among this group. There may also be benefits in assessing unmet needs and addressing these where possible as part of an approach to reducing depression among people living with dementia in the community.

ACR Appropriateness Criteria® Thoracoabdominal Aortic Aneurysm or Dissection: Treatment Planning and Follow-Up.

As the incidence of thoracoabdominal aortic pathology (aneurysm and dissection) rises and the complexity of endovascular and surgical treatment options increases, imaging follow-up of patients remains crucial. Patients with thoracoabdominal aortic pathology without intervention should be monitored carefully for changes in aortic size or morphology that could portend rupture or other complication. Patients who are post endovascular or open surgical aortic repair should undergo follow-up imaging to evaluate for complications, endoleak, or recurrent pathology. Considering the quality of diagnostic data, CT angiography and MR angiography are the preferred imaging modalities for follow-up of thoracoabdominal aortic pathology for most patients. The extent of thoracoabdominal aortic pathology and its potential complications involve multiple regions of the body requiring imaging of the chest, abdomen, and pelvis in most patients. The ACR Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision process support the systematic analysis of the medical literature from peer reviewed journals. Established methodology principles such as Grading of Recommendations Assessment, Development, and Evaluation or GRADE are adapted to evaluate the evidence. The RAND/UCLA Appropriateness Method User Manual provides the methodology to determine the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where peer reviewed literature is lacking or equivocal, experts may be the primary evidentiary source available to formulate a recommendation.

Another new species of Glossocephalus (Crustacea: Amphipoda: Hyperiidea: Oxycephalidae) from the Monterey Bay region, California, USA.

A new species of Glossocephalus, G. aurantium sp. nov., is described based on two female specimens collected from the Monterey Canyon, California, eastern Pacific Ocean. It was found associated with an undescribed lobate ctenophore. Glossocephalus aurantium is readily distinguished from its congeners by the large crescent-shaped bulbous eye fields relative to the size of the head capsule. The pereopod morphology is most similar to G. rebecae, recently described from the same general region by Zeidler and Browne (2015), but that species is readily distinguished by it's relatively narrow crescent-shaped eye fields. Apart from it's prominent bulbous eye structures, G. aurantium is distinguished from G. milneedwardsi by the morphology of the gnathopods (not spoon-shaped). In addition, pereopods 5 and 6 are slender (not paddle-like) and the head capsule is relatively larger with a sharp rostrum (not rounded).

Multi-institutional Retrospective Study of Percutaneous Cholangioscopy-Assisted Lithotripsy for Inoperable Calculous Cholecystitis.

PURPOSE: This study aimed to assess the safety and efficacy of percutaneous lithotripsy for gallstone eradication in patients with calculous cholecystitis with stones >1 cm. MATERIALS AND METHODS: Multi-institutional institutional review board approved retrospective review of patients who presented with calculous cholecystitis and were not determined to be surgical candidates. All patients underwent percutaneous cholecystostomy tube placement for acute infection, which was later exchanged for a large sheath for ShockPulse (Olympus, Tokyo, Japan) lithotripsy and stone destruction. Review parameters included procedural technical and clinical data, including clinical presentation, mean length of hospital stay, and postintervention symptom reduction. RESULTS: Twelve patients (mean age, 74.6 years; range, 52-94 years; 6 men and 6 women) underwent large-bore sheath (24-30 F) cholangioscopy-assisted gallstone destruction via rigid lithotripsy. The size of the gallstones ranged from 1.2 to 4.0 cm. All patients had prior cholecystostomy access for a mean of 25 weeks before gallstone extraction to ensure tract maturation via transhepatic or transperitoneal access. The technical success rate in single-session stone removal was 100%, with no major procedure-related adverse events. All patients were symptom- and pain-free after the procedure. The mean procedure time was 111.5 minutes, and the mean fluoroscopy time was 19.2 minutes. The median length of hospital stay was 1 day after the procedure. The mean time from percutaneous lithotripsy to biliary tube removal was 35 days (range, 17-45 days). CONCLUSIONS: Fluoroscopy-guided percutaneous rigid lithotripsy is a safe and effective procedure for gallstone destruction and extraction in patients who are poor surgical candidates with large lumen-occupying cholelithiasis.

Short midline catheters: High success rates for antibiotic therapy in children with cystic fibrosis.

OBJECTIVE: Short midline catheter use in paediatric populations appears to be increasing, however data on success rates and efficacy are sparse. This study aims to describe the success rate when midline venous catheters are employed as a single device for intravenous antibiotic therapy in paediatric patients with cystic fibrosis. METHODS: A retrospective cohort study was performed in a single institution, retrieving electronic medical record data from July 2017 through March 2020. The primary outcome was device success, defined as a catheter that remained functional until the end of antibiotic therapy. Reasons for device failure were categorized in a standard fashion. RESULTS: Primary outcome data were available for 116 catheter insertions, involving 49 patients and 55 proceduralists. The success rate was 84% (n = 98). Median age at insertion was 15 years (range 4-19) and median weight 52 kg (13-81). Soft, polyether block amide, Arrow® Seldinger Arterial Catheters were employed. Only 16 patients (14%) required general anaesthesia. Median time to failure was 6 days, and median time to successful completion of treatment was 13 days. Six of 18 failures occurred within 48 h and were likely insertion complications. The most common reasons for device failure were occlusion, extravasation, phlebitis and dislodgement. More than half of patients (56%) received antibiotic therapy at home. CONCLUSION: There is a high single device success rate when inserting short midlines for 13-day intravenous pulmonary antibiotic therapy in children with cystic fibrosis. These results should be confirmed with a prospective study.

Quantification of Respirable Aerosol Particles from Speech and Language Therapy Exercises.

INTRODUCTION: Voice assessment and treatment involve the manipulation of all the subsystems of voice production, and may lead to production of respirable aerosol particles that pose a greater risk of potential viral transmission via inhalation of respirable pathogens (eg, SARS-CoV-2) than quiet breathing or conversational speech. OBJECTIVE: To characterise the production of respirable aerosol particles during a selection of voice assessment therapy tasks. METHODS: We recruited 23 healthy adult participants (12 males, 11 females), 11 of whom were speech-language pathologists specialising in voice disorders. We used an aerodynamic and an optical particle sizer to measure the number concentration and particle size distributions of respirable aerosols generated during a variety of voice assessment and therapy tasks. The measurements were carried out in a laminar flow operating theatre, with a near-zero background aerosol concentration, allowing us to quantify the number concentration and size distributions of respirable aerosol particles produced from assessment/therapy tasks studied. RESULTS: Aerosol number concentrations generated while performing assessment/therapy tasks were log-normally distributed among individuals with no significant differences between professionals (speech-language pathologists) and non-professionals or between males and females. Activities produced up to 32 times the aerosol number concentration of breathing and 24 times that of speech at 70-80 dBA. In terms of aerosol mass, activities produced up to 163 times the mass concentration of breathing and up to 36 times the mass concentration of speech. Voicing was a significant factor in aerosol production; aerosol number/mass concentrations generated during the voiced activities were 1.1-5 times higher than their unvoiced counterpart activities. Additionally, voiced activities produced bigger respirable aerosol particles than their unvoiced variants except the trills. Humming generated higher aerosol concentrations than sustained /a/, fricatives, speaking (70-80 dBA), and breathing. Oscillatory semi-occluded vocal tract exercises (SOVTEs) generated higher aerosol number/mass concentrations than the activities without oscillation. Water resistance therapy (WRT) generated the most aerosol of all activities, ∼10 times higher than speaking at 70-80 dBA and >30 times higher than breathing. CONCLUSIONS: All activities generated more aerosol than breathing, although a sizeable minority were no different to speaking. Larger number concentrations and larger particle sizes appear to be generated by activities with higher suspected airflows, with the greatest involving intraoral pressure oscillation and/or an oscillating oral articulation (WRT or trilling).

A comparison of respiratory particle emission rates at rest and while speaking or exercising.

Background: The coronavirus disease-19 (COVID-19) pandemic led to the prohibition of group-based exercise and the cancellation of sporting events. Evaluation of respiratory aerosol emissions is necessary to quantify exercise-related transmission risk and inform mitigation strategies. Methods: Aerosol mass emission rates are calculated from concurrent aerosol and ventilation data, enabling absolute comparison. An aerodynamic particle sizer (0.54-20 µm diameter) samples exhalate from within a cardiopulmonary exercise testing mask, at rest, while speaking and during cycle ergometer-based exercise. Exercise challenge testing is performed to replicate typical gym-based exercise and very vigorous exercise, as determined by a preceding maximally exhaustive exercise test. Results: We present data from 25 healthy participants (13 males, 12 females; 36.4 years). The size of aerosol particles generated at rest and during exercise is similar (unimodal ~0.57-0.71 µm), whereas vocalization also generated aerosol particles of larger size (i.e. was bimodal ~0.69 and ~1.74 µm). The aerosol mass emission rate during speaking (0.092 ng s-1; minute ventilation (VE) 15.1 L min-1) and vigorous exercise (0.207 ng s-1, p = 0.726; VE 62.6 L min-1) is similar, but lower than during very vigorous exercise (0.682 ng s-1, p < 0.001; VE 113.6 L min-1). Conclusions: Vocalisation drives greater aerosol mass emission rates, compared to breathing at rest. Aerosol mass emission rates in exercise rise with intensity. Aerosol mass emission rates during vigorous exercise are no different from speaking at a conversational level. Mitigation strategies for airborne pathogens for non-exercise-based social interactions incorporating vocalisation, may be suitable for the majority of exercise settings. However, the use of facemasks when exercising may be less effective, given the smaller size of particles produced.

Isolation and Maintenance of In Vitro Cell Cultures from the Ctenophore Mnemiopsis leidyi.

The ability to isolate, monitor, and examine specific cells of interest enables targeted experimental manipulations that would otherwise be difficult to perform and interpret in the context of the whole organism. In vitro primary cell cultures derived from ctenophores thus serve as an important tool for understanding complex cellular and molecular interactions that take place both within and between various ctenophore cell types. Here we describe methods for reliably generating and maintaining primary cell cultures derived from the lobate ctenophore Mnemiopsis leidyi that can be used for a wide variety of experimental applications.

Comparing aerosol number and mass exhalation rates from children and adults during breathing, speaking and singing.

Aerosol particles of respirable size are exhaled when individuals breathe, speak and sing and can transmit respiratory pathogens between infected and susceptible individuals. The COVID-19 pandemic has brought into focus the need to improve the quantification of the particle number and mass exhalation rates as one route to provide estimates of viral shedding and the potential risk of transmission of viruses. Most previous studies have reported the number and mass concentrations of aerosol particles in an exhaled plume. We provide a robust assessment of the absolute particle number and mass exhalation rates from measurements of minute ventilation using a non-invasive Vyntus Hans Rudolf mask kit with straps housing a rotating vane spirometer along with measurements of the exhaled particle number concentrations and size distributions. Specifically, we report comparisons of the number and mass exhalation rates for children (12-14 years old) and adults (19-72 years old) when breathing, speaking and singing, which indicate that child and adult cohorts generate similar amounts of aerosol when performing the same activity. Mass exhalation rates are typically 0.002-0.02 ng s-1 from breathing, 0.07-0.2 ng s-1 from speaking (at 70-80 dBA) and 0.1-0.7 ng s-1 from singing (at 70-80 dBA). The aerosol exhalation rate increases with increasing sound volume for both children and adults when both speaking and singing.

Predictors of biliary intervention in patients hospitalized for COVID-19.

BACKGROUND: Gastrointestinal complications of coronavirus disease-2019 (COVID-19) include abnormal liver function and acalculous cholecystitis. Cholecystostomy performed during the COVID-19 pandemic reflected a shift toward non-surgical treatment of cholecystitis and increased number of critically ill patients suffering from acalculous cholecystitis. PURPOSE: (1) To determine demographic, clinical, laboratory, and ultrasound features associated with cholecystostomy placement during hospitalization for COVID-19. (2) To develop multivariable logistic regression modeling for likelihood of biliary intervention. METHODS: This retrospective review received institutional review board approval. Informed consent was waived. Between March 2020 and June 2020, patients with confirmed SARS-CoV2 infection admitted to New York-Presbyterian Hospital (NYP)/Weill Cornell Medical Center, NYP/Lower Manhattan Hospital, and NYP/Queens were evaluated for inclusion in this study. Inclusion criteria were (1) patient age ≥ 18, (2) confirmed COVID-19 infection by polymerase chain reaction testing of a nasopharyngeal swab, and (3) abdominal ultrasound performed during hospitalization. Exclusion criteria were (1) history of cholecystectomy and (2) biliary intervention performed prior to abdominal ultrasound. Patients were stratified into two groups based on whether they received cholecystostomy during hospitalization. Differences in demographics, medical history, clinical status, medications, laboratory values, and ultrasound findings between the two groups were evaluated using Chi-square test or Fisher's exact test for categorical variables and t test or Wilcoxon-rank sum test for continuous variables. Multivariable logistic regression was used to model likelihood of biliary intervention. RESULTS: Nine patients underwent cholecystostomy placement and formed the "Intervention Group." 203 patients formed the "No Intervention Group." Liver size and diuretics use during hospitalization were the only variables which were significantly different between the two groups, with p-values of 0.02 and 0.046, respectively. After controlling for diuretics use, the odds of receiving cholecystostomy increased by 30% with every centimeter increase in liver size (p = 0.03). ICU admission approached significance (p = 0.16), as did mechanical ventilation (p = 0.09), septic shock (p = 0.08), serum alkaline phosphatase level (p = 0.16), and portal vein patency (0.14). CONCLUSION: Patients requiring biliary intervention during hospital admission for COVID-19 were likely to harbor liver injury in the form of liver enlargement and require diuretics use.

The Early Social Cognition Inventory (ESCI): An examination of its psychometric properties from birth to 47 months.

Social cognition refers to a broad range of cognitive processes and skills that allow individuals to interact with and understand others, including a variety of skills from infancy through preschool and beyond, e.g., joint attention, imitation, and belief understanding. However, no measures examine socio-cognitive development from birth through preschool. Current test batteries and parent-report measures focus either on infancy, or toddlerhood through preschool (and beyond). We report six studies in which we developed and tested a new 21-item parent-report measure of social cognition targeting 0-47 months: the Early Social Cognition Inventory (ESCI). Study 1 (N = 295) revealed the ESCI has excellent internal reliability, and a two-factor structure capturing social cognition and age. Study 2 (N = 605) also showed excellent internal reliability and confirmed the two-factor structure. Study 3 (N = 84) found a medium correlation between the ESCI and a researcher-administered social cognition task battery. Study 4 (N = 46) found strong 1-month test-retest reliability. Study 5 found longitudinal stability (6 months: N = 140; 12 months: N = 39), and inter-observer reliability between parents (N = 36) was good, and children's scores increased significantly over 6 and 12 months. Study 6 showed the ESCI was internally reliable within countries (Australia, Canada, United Kingdom, United States, Trinidad and Tobago); parent ethnicity; parent education; and age groups from 4-39 months. ESCI scores positively correlated with household income (UK); children with siblings had higher scores; and Australian parents reported lower scores than American, British, and Canadian parents.

The Early Humor Survey (EHS): A reliable parent-report measure of humor development for 1- to 47-month-olds.

We created a 20-item parent-report measure of humor development from 1 to 47 months: the Early Humor Survey (EHS). We developed the EHS with Study 1 (N = 219) using exploratory factor analysis, demonstrating the EHS works with 1- to 47-month-olds with excellent reliability and a strong correlation with age, showing its developmental trajectory. We replicated the EHS with Study 2 (N = 587), revealing a one-factor structure, showing excellent reliability, and replicating a strong correlation with age. Study 3 (N = 84) found the EHS correlated with a humor experiment, however it no longer correlated once age was accounted for, suggesting low convergent validity. Subsamples of parents from Studies 2 and 3 showed excellent inter-observer reliability between both parents, and good longitudinal stability after 6 months. Combining participants from all studies, we found the EHS is reliable across countries (Australia, United Kingdom, United States), parent education levels, and children's age groups. We charted expected humor development by age (in months), and the expected proportion of children who would appreciate each humor type by age (in months). Finally, we found no demographic differences (e.g., country: Australia, Canada, United Kingdom, United States; parents' education) in humor when pooling all data. The EHS is a valuable tool that will allow researchers to understand how humor: (1) emerges; and (2) affects other aspects of life, e.g., making friends, coping with stress, and creativity. The EHS is helpful for parents, early years educators, and children's media, as it systematically charts early humor development.

Invasion genomics uncover contrasting scenarios of genetic diversity in a widespread marine invader.

Invasion rates have increased in the past 100 y irrespective of international conventions. What characterizes a successful invasion event? And how does genetic diversity translate into invasion success? Employing a whole-genome perspective using one of the most successful marine invasive species world-wide as a model, we resolve temporal invasion dynamics during independent invasion events in Eurasia. We reveal complex regionally independent invasion histories including cases of recurrent translocations, time-limited translocations, and stepping-stone range expansions with severe bottlenecks within the same species. Irrespective of these different invasion dynamics, which lead to contrasting patterns of genetic diversity, all nonindigenous populations are similarly successful. This illustrates that genetic diversity, per se, is not necessarily the driving force behind invasion success. Other factors such as propagule pressure and repeated introductions are an important contribution to facilitate successful invasions. This calls into question the dominant paradigm of the genetic paradox of invasions, i.e., the successful establishment of nonindigenous populations with low levels of genetic diversity.

Krüppel-like factor gene function in the ctenophore Mnemiopsis leidyi assessed by CRISPR/Cas9-mediated genome editing.

The Krüppel-like factor (Klf) gene family encodes transcription factors that play an important role in the regulation of stem cell proliferation, cell differentiation and development in bilaterians. Although Klf genes have been shown to specify functionally various cell types in non-bilaterian animals, their role in early-diverging animal lineages has not been assessed. Thus, the ancestral activity of these transcription factors in animal development is not well understood. The ctenophore Mnemiopsis leidyi has emerged as an important non-bilaterian model system for understanding early animal evolution. Here, we characterize the expression and functional role of Klf genes during M. leidyi embryogenesis. Zygotic Klf gene function was assessed with both CRISPR/Cas9-mediated genome editing and splice-blocking morpholino oligonucleotide knockdown approaches. Abrogation of zygotic Klf expression during M. leidyi embryogenesis resulted in abnormal development of several organs, including the pharynx, tentacle bulbs and apical organ. Our data suggest an ancient role for Klf genes in regulating endodermal patterning, possibly through regulation of cell proliferation.