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Induced pluripotent stem cell (iPSC)-based models are excellent platforms to understand blood development, and iPSC-derived blood cells have translational utility as clinical testing reagents and transfusable cell therapeutics. The advent and expansion of multiomics analysis, including but not limited to single nucleus RNA sequencing (snRNAseq) and Assay for Transposase-Accessible Chromatin sequencing (snATACseq), offers the potential to revolutionize our understanding of cell development. This includes developmental biology using in vitro hematopoietic models. However, it can be technically challenging to isolate intact nuclei from cultured or primary cells. Different cell types often require tailored nuclear preparations depending on cellular rigidity and content. These technical difficulties can limit data quality and act as a barrier to investigators interested in pursuing multiomics studies. Specimen cryopreservation is often necessary due to limitations with cell collection and/or processing, and frozen samples can present additional technical challenges for intact nuclear isolation. In this manuscript, we provide a detailed method to isolate high-quality nuclei from iPSC-derived cells at different stages of in vitro hematopoietic development for use in single-nucleus multiomics workflows. We have focused the method development on the isolation of nuclei from iPSC-derived adherent stromal/endothelial cells and non-adherent hematopoietic progenitor cells, as these represent very different cell types with regard to structural and cellular identity. The described troubleshooting steps limited nuclear clumping and debris, allowing the recovery of nuclei in sufficient quantity and quality for downstream analyses. Similar methods may be adapted to isolate nuclei from other cryopreserved cell types.

The CHOPWT17_TPM1KOc28 iPSC line was generated to interrogate the functions of Tropomyosin 1 (TPM1) in primary human cell development. This line was reprogrammed from a previously published wild type control iPSC line., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 The Author(s). Published by Elsevier B.V. All rights reserved.)

Rapid diagnostic tools available to the emergency physician caring for cardiac arrest patients are limited. Focused ultrasound (US), and in particular, focused echocardiography, is a useful tool in the evaluation of patients in cardiac arrest. It can help identify possible causes of cardiac arrest like tamponade and pulmonary embolism, which can guide therapy. US can also yield prognostic information, with lack of cardiac activity being highly specific for failure to achieve return of spontaneous circulation. US may also be used to aid in procedural guidance. Recently, focused transesophageal echocardiography has been used in the emergency department setting., (Copyright © 2023 Elsevier Inc. All rights reserved.)

Introduction: Ultrasonography has an important role in the evaluation of Emergency Department (ED) patients presenting with early pregnancy complaints. Both transabdominal (TAUS) and transvaginal ultrasound (TVUS) can be utilized. While TVUS generally allows for greater detail, it is unclear how much added benefit exists in performing TVUS once an intrauterine pregnancy (IUP) has been identified on TAUS., Methods: This was a retrospective study utilizing Radiology Department ultrasound examinations obtained in first trimester pregnancy ED patients during a consecutive four month period in 2019. Studies wherein both TAUS and TVUS were both performed were included. Two ED physicians with specialized training in point of care ultrasound reviewed only the TAUS images from these studies. Their findings were compared to the Radiologist interpretation, which was inclusive of both TAUS and TVUS components of the study., Results: 108 studies met inclusion criteria. Amongst these, 82 had IUP's identified on the radiologist report. 69 studies had an IUP identified by ED physician review of the TAUS images, with 1 false positive. Each case of intrauterine fetal demise (IUFD) was identified on ED physician review of TAUS. Two ectopic pregnancies were present, neither of which was mistaken for IUP on ED physician TAUS review. There were 15 studies with subchorionic hemorrhage and 3 studies with an ovarian cyst noted on the radiologist report., Conclusion: Following the identification of an IUP on TAUS, the added diagnostic value of TVUS amongst this cohort of ED patients was low. Given the added time and cost of TVUS, selective instead of routine usage should be encouraged., Competing Interests: The authors report no conflicts of interest in this work., (© 2023 Thom et al.)

Introduction: Neuropathy of the lateral femoral cutaneous nerve, also known as meralgia paresthetica, causes pain and paresthesia to the anterolateral thigh. It commonly results from nerve irritation from extrinsic compression; however, it may occur spontaneously. Symptoms from this condition can be debilitating, and the pain may be ascribed to other conditions leading to delays in diagnosis. Peripheral nerve blockade can be useful both diagnostically and therapeutically for meralgia paresthetica., Case Report: Two female patients in their sixties presented to the emergency department for chronic, atraumatic, left upper thigh pain. In both cases the patients had hyperalgesia and paresthesia to the anterolateral, upper thigh. The emergency physician performed an ultrasound-guided nerve block of the lateral femoral cutaneous nerve for each patient, which resulted in temporary, complete resolution of their pain., Conclusion: Meralgia paresthetica is an uncommon but painful condition that can elude diagnosis. Physical exam findings such as allodynia and hyperalgesia of the anterolateral thigh in the absence of back pain is suggestive of the diagnosis. Utrasound-guided nerve blockade can be helpful to the emergency physician to confirm the diagnosis and provide non-opioid pain relief to the patient.

Introduction It is commonly taught that positioning the patient in the left lateral decubitus (LLD) position will improve transthoracic echocardiography (TTE) image quality. Despite this, no previous studies have been performed that study this practice. Our goal was to quantify the difference in image quality of TTE views between the supine and LLD positions.  Methods This was a prospective study in a single academic Emergency Department (ED) of a convenience sample of 30 patients. Three separate ED physicians performed TTE views in both the supine and LLD position on each patient. The order of position was randomized. Images were then reviewed on a previously validated TTE image quality scale by two blinded ED physicians with specialized training in ultrasound. The scale used a 0 to 5 (highest quality) metric for quality assessment. Interpretability of right ventricular and left ventricular function was also assessed. Results The mean image quality for the supine position was 2.85 (standard deviation {SD} 1.1) and 3.05 (SD 1.2) for the LLD position (p=0.044). In the subset of parasternal and apical windows, the mean quality for the supine position was 2.87 (SD 1.1) and 3.23 (SD 1.1) for the LLD position (p=0.003). The number of studies in which right ventricular function was interpretable was significantly higher in the LLD position (62% versus 42%, p=0.044). Conclusions There was a statistically significant increase in image quality when TTE was performed in the LLD position as compared to supine. This was especially pronounced in the apical four and parasternal windows., Competing Interests: The authors have declared that no competing interests exist., (Copyright © 2022, Ottenhoff et al.)

Background: The majority of Genome Wide Associate Study (GWAS) loci fall in the non-coding genome, making causal variants difficult to identify and study. We hypothesized that the regulatory features underlying causal variants are biologically specific, identifiable from data, and that the regulatory architecture that influences one trait is distinct compared to biologically unrelated traits., Results: To better characterize and identify these variants, we used publicly available GWAS loci and genomic annotations to build 17 Trait Specific Annotation Based Locus (TSABL) predictors to identify differences between GWAS loci associated with different phenotypic trait groups. We used a penalized binomial logistic regression model to select trait relevant annotations and tested all models on a holdout set of loci not used for training in any trait. We were able to successfully build models for autoimmune, electrocardiogram, lipid, platelet, red blood cell, and white blood cell trait groups. We used these models both to prioritize variants in existing loci and to identify new genomic regions of interest., Conclusions: We found that TSABL models identified biologically relevant regulatory features, and anticipate their future use to enhance the design and interpretation of genetic studies., (© 2022. The Author(s).)

Introduction: Abdominal compartment syndrome (ACS) is a rare condition in which increased intra-abdominal pressure causes multiorgan dysfunction through decreased perfusion. Causes of this condition are variable, and early recognition is critical for favorable patient outcomes. Measurement of bladder pressure is recommended for diagnosis., Case Report: A 64-year-old female on clozapine with a two-year history of chronic constipation presented to the emergency department in extremis with a protuberant abdomen. After resuscitative measures, computed tomography showed a dilated, stool-filled colon with a decompressed inferior vena cava and decreased perfusion. She died despite surgical decompression., Conclusion: Severe constipation is a rare cause of ACS, and there is a lack of evidence-based guidelines. Options for bedside decompression are limited. To reduce morbidity and mortality in this population, early recognition of ACS is imperative. Initial interventions should support hemodynamics and respiration. Definitive management is surgical decompression.

Background: Genetic associations link hematopoietic traits and disease end-points, but most causal variants and genes underlying these relationships are unknown. Here, we used genetic colocalization to nominate loci and genes related to shared genetic signal for hematopoietic, cardiovascular, autoimmune, neuropsychiatric, and cancer phenotypes., Methods: Our aim was to identify colocalization sites for human traits among established genome-wide significant loci. Using genome-wide association study (GWAS) summary statistics, we determined loci where multiple traits colocalized at a false discovery rate < 5%. We then identified quantitative trait loci among colocalization sites to highlight related genes. In addition, we used Mendelian randomization analysis to further investigate certain trait relationships genome-wide., Results: Our findings recapitulated developmental hematopoietic lineage relationships, identified loci that linked traits with causal genetic relationships, and revealed novel trait associations. Out of 2706 loci with genome-wide significant signal for at least 1 blood trait, we identified 1779 unique sites (66%) with shared genetic signal for 2+ hematologic traits. We could assign some sites to specific developmental cell types during hematopoiesis based on affected traits, including those likely to impact hematopoietic progenitor cells and/or megakaryocyte-erythroid progenitor cells. Through an expanded analysis of 70 human traits, we defined 2+ colocalizing traits at 2123 loci from an analysis of 9852 sites (22%) containing genome-wide significant signal for at least 1 GWAS trait. In addition to variants and genes underlying shared genetic signal between blood traits and disease phenotypes that had been previously related through Mendelian randomization studies, we defined loci and related genes underlying shared signal between eosinophil percentage and eczema. We also identified colocalizing signals in a number of clinically relevant coding mutations, including sites linking PTPN22 with Crohn's disease, NIPA with coronary artery disease and platelet trait variation, and the hemochromatosis gene HFE with altered lipid levels. Finally, we anticipate potential off-target effects on blood traits related novel therapeutic targets, including TRAIL., Conclusions: Our findings provide a road map for gene validation experiments and novel therapeutics related to hematopoietic development, and offer a rationale for pleiotropic interactions between hematopoietic loci and disease end-points.

Background: Identifying causal variants and genes from human genetic studies of hematopoietic traits is important to enumerate basic regulatory mechanisms underlying these traits, and could ultimately augment translational efforts to generate platelets and/or red blood cells in vitro. To identify putative causal genes from these data, we performed computational modeling using available genome-wide association datasets for platelet and red blood cell traits., Results: Our model identified a joint collection of genomic features enriched at established trait associations and plausible candidate variants. Additional studies associating variation at these loci with change in gene expression highlighted Tropomyosin 1 (TPM1) among our top-ranked candidate genes. CRISPR/Cas9-mediated TPM1 knockout in human induced pluripotent stem cells (iPSCs) enhanced hematopoietic progenitor development, increasing total megakaryocyte and erythroid cell yields., Conclusions: Our findings may help explain human genetic associations and identify a novel genetic strategy to enhance in vitro hematopoiesis. A similar trait-specific gene prioritization strategy could be employed to help streamline functional validation experiments for virtually any human trait.

Human induced pluripotent stem cell (iPSC)-based model systems can be used to produce blood cells for the study of both hematologic and non-hematologic disorders. This commentary discusses recent advances that have utilized iPSC-derived red blood cells, megakaryocytes, myeloid cells, and lymphoid cells to model hematopoietic disorders. In addition, we review recent studies that have defined how microglial cells differentiated from iPSC-derived monocytes impact neurodegenerative disease. Related translational insights highlight the utility of iPSC models for studying pathologic anemia, bleeding, thrombosis, autoimmunity, immunodeficiency, blood cancers, and neurodegenerative disease such as Alzheimer's., Competing Interests: Conflicts of Interest The authors declare no relevant conflicts of interest.

Background: Renal colic is a frequently encountered diagnosis among emergency department patients. Point-of-care (POC) ultrasound has taken on an increasingly important role in the diagnostic strategy of this disease, as it has been shown to be an effective modality for diagnosis and for guiding management. The primary pathology that the emergency physician will evaluate for in cases of suspected renal colic is hydronephrosis, which is a dilatation of the renal pelvis and calyces resulting from a distal obstruction such as a ureteral stone. However, other significant findings can be seen, one of which is the extravasation of urine around the kidney secondary to a forniceal, or calyceal, rupture., Case Series: We present three cases of unanticipated perinephric fluid collections identified initially on POC ultrasound in cases of suspected simple renal colic. Concomitant hydronephrosis was also seen in each of these cases. Why Should an Emergency Physician Be Aware of This? While the utilization of POC ultrasound in cases of suspected renal colic increases, we should be prepared to encounter and identify perinephric fluid collections in our evaluations. Although the ideal management of these cases is not completely defined from the current literature, we benefit from knowing how to identify these on POC ultrasound, understanding the underlying pathophysiology, and appreciating the possibility of complications that may arise., (Copyright © 2018 Elsevier Inc. All rights reserved.)

Inherited platelet disorders (IPD) are a heterogeneous group of rare disorders that affect platelet number and function and often predispose to other significant medical complications. In spite of the identification of over 50 IPD disease-associated genes, a molecular diagnosis is only identified in a minority (10%) of affected patients without a clinically suspected etiology. We studied a cohort of 21 pediatric patients with suspected IPDs by exome sequencing (ES) to: (1) examine the performance of the exome test for IPD genes, (2) determine if this exome-wide diagnostic test provided a higher diagnostic yield than has been previously reported, (3) to evaluate the frequency of variants of uncertain significance identified, and (4) to identify candidate variants for functional evaluation in patients with an uncertain or negative diagnosis. We established a high priority gene list of 53 genes, evaluated exome capture kit performance, and determined the coverage for these genes and disease-related variants. We identified likely disease causing variants in 5 of the 21 probands (23.8%) and variants of uncertain significance in 52% of patients studied. In conclusion, ES has the potential to molecularly diagnose causes of IPD, and to identify candidate genes for functional evaluation. Robust exome sequencing also requires that coverage of genes known to be associated with clinical findings of interest need to be carefully examined and supplemented if necessary. Clinicians who undertake ES should understand the limitations of the test and the full significance of results that may be returned., (© 2017 Wiley Periodicals, Inc.)

Background: Point-of-care ultrasound has an increasing role in characterizing soft-tissue infections and has been described previously in the evaluation of necrotizing fasciitis (NF). The identification of air within the soft tissues can be very suggestive of NF in the correct clinical context., Case Report: A 78-year-old male presented to the emergency department with extensive lower-extremity redness and edema. A point-of-care ultrasound revealed hyperechoic areas within the soft tissues consistent with air, and the patient was taken to surgery and found to have NF. A 60-year-old female presented to the emergency department with physical examination findings consistent with severe cellulitis and associated sepsis. A point-of-care ultrasound revealed hyperechoic areas within the soft tissue that were very similar to the prior case. An emergent surgical consultation was placed due to concern for soft-tissue air and NF. However, these hyperechoic areas were found to be subcutaneous calcifications on subsequent imaging. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: Air within the soft tissue is easy to identify on point-of-care ultrasound and can expedite surgical evaluation in cases of suspected NF. Calcifications can mimic the appearance of air on ultrasound and the distinction between these objects can often be made based on the echotexture of the posterior acoustic shadow. Attention to the posterior acoustic shadow can facilitate correct identification of various structures and pathologies in a variety of clinical settings., (Copyright © 2016 Elsevier Inc. All rights reserved.)

Diseases affecting hemoglobin synthesis and function are extremely common worldwide. More than 1000 naturally occurring human hemoglobin variants with single amino acid substitutions throughout the molecule have been discovered, mainly through their clinical and/or laboratory manifestations. These variants alter hemoglobin structure and biochemical properties with physiological effects ranging from insignificant to severe. Studies of these mutations in patients and in the laboratory have produced a wealth of information on hemoglobin biochemistry and biology with significant implications for hematology practice. More generally, landmark studies of hemoglobin performed over the past 60 years have established important paradigms for the disciplines of structural biology, genetics, biochemistry, and medicine. Here we review the major classes of hemoglobin variants, emphasizing general concepts and illustrative examples.