Low- versus high-dose nitroglycerin infusion in the management of acute pulmonary edema.

BACKGROUND: Nitroglycerin (NTG) is commonly used for the management of pulmonary edema in acute heart failure presentations. Although commonly initiated at low infusion rates, higher infusion rates have favorable pharmacodynamic properties and may improve outcomes in the management of acute pulmonary edema. OBJECTIVES: To characterize the clinical outcomes including the time to resolution of severe hypertension when using an initial low dose (<100 µg/min) versus high-dose (≥100 µg/min) strategy. METHODS: This was a retrospective study performed at a single, tertiary academic emergency department in Atlanta, GA. We describe the blood pressure effects and key safety outcomes (intubation, hypotension, intensive care unit admissions) during the first hour of treatment of acute pulmonary edema. RESULTS: 41 patients were included in the final sample. 27 (66%) received low dose NTG and 14 (34%) received high dose NTG. The high dose group reached their blood pressure faster on average (hazard ratio = 3.5, 95% CI: 1.2-10.1). 8/14 (57%) of patients in the high dose group reached their BP target within the first hour of treatment, compared to 6/27 (22%) in the low dose group. Observed incidence of safety outcomes were similar between the two groups. CONCLUSIONS: Higher initial NTG doses may be an effective way to decrease times to achieve blood pressure targets and should be the focus of future trials.

Anatomic Characteristics of the Adolescent Cricothyroid Membrane on Computed Tomography Scans.

BACKGROUND: The cricothyroid membrane (CTM) is the most important anatomic structure when performing emergency front-of-neck access (FONA) procedures. Adolescence is a period of rapid morphologic change in laryngeal structures, including the CTM. We hypothesized that the adolescent CTM would be sufficiently different from pediatric or adult anatomy to merit special consideration in FONA. OBJECTIVE: The aim of the study was to define the procedurally relevant CTM anatomy in an adolescent population. METHODS: This was a retrospective, multicenter cohort study composed of patients who underwent a diagnostic computed tomography scan during routine clinical care. Inclusion criteria were ages 16 to 19 years and a computed tomography of the neck with or without contrast. The primary outcome was CTM height measured in the midsagittal plane using electronic calipers. RESULTS: One hundred thirty-four imaging studies met inclusion criteria. The average CTM height was strongly associated with age and ranged between 5.4 and 6.2 mm in male adolescents and 4.6 and 5.8 mm in female adolescents. We predicted that standard cuffed endotracheal and tracheostomy tubes recommended for FONA procedures (5.0- and 6.0-mm devices) could potentially fail for most patients in our cohort. CONCLUSIONS: The adolescent CTM is smaller than previously recognized. We recommend having a variety of equipment sizes readily available at any site where airway management in adolescents may occur.

A streamlined whole blood CyTOF workflow defines a circulating immune cell signature of COVID-19.

Mass cytometry (CyTOF) represents one of the most powerful tools in immune phenotyping, allowing high throughput quantification of over 40 parameters at single-cell resolution. However, wide deployment of CyTOF-based immune phenotyping studies are limited by complex experimental workflows and the need for specialized CyTOF equipment and technical expertise. Furthermore, differences in cell isolation and enrichment protocols, antibody reagent preparation, sample staining, and data acquisition protocols can all introduce technical variation that can confound integrative analyses of large data-sets of samples processed across multiple labs. Here, we present a streamlined whole blood CyTOF workflow which addresses many of these sources of experimental variation and facilitates wider adoption of CyTOF immune monitoring across sites with limited technical expertise or sample-processing resources or equipment. Our workflow utilizes commercially available reagents including the Fluidigm MaxPar Direct Immune Profiling Assay (MDIPA), a dry tube 30-marker immunophenotyping panel, and SmartTube Proteomic Stabilizer, which allows for simple and reliable fixation and cryopreservation of whole blood samples. We validate a workflow that allows for streamlined staining of whole blood samples with minimal processing requirements or expertise at the site of sample collection, followed by shipment to a central CyTOF core facility for batched downstream processing and data acquisition. We apply this workflow to characterize 184 whole blood samples collected longitudinally from a cohort of 72 hospitalized COVID-19 patients and healthy controls, highlighting dynamic disease-associated changes in circulating immune cell frequency and phenotype.

Dentate Nucleus Neuronal Density: A Postmortem Study of Essential Tremor Versus Control Brains.

BACKGROUND: Essential tremor involves the cerebellum, yet quantitative analysis of dentate nucleus neurons has not been conducted. OBJECTIVES: To quantitatively compare neuronal density or neuronal number in the dentate nucleus of essential tremor versus age-matched controls. METHODS: Using a 7-µm thick Luxol fast blue hematoxylin and eosin-stained paraffin section, dentate nucleus neuronal density (neurons/mm2 ) was determined in 25 essential tremor cases and 25 controls. We also applied a stereological approach in a subset of four essential tremor cases and four controls to estimate total dentate nucleus neuronal number. RESULTS: Dentate nucleus neuronal density did not differ between essential tremor cases and controls (P = 0.44). Total dentate nucleus neuronal number correlated with neuronal density (P = 0.007) and did not differ between essential tremor cases and controls (P = 0.95). CONCLUSIONS: Neuronal loss, observed in the Purkinje cell population in essential tremor, did not seem to similarly involve the dentate nucleus in essential tremor. © 2020 International Parkinson and Movement Disorder Society.

Pediatric Difficult Airway Response Team Utilization in the Emergency Department: A Case Series.

OBJECTIVES: A multidisciplinary pediatric difficult airway team was created at our institution to respond to hospital-wide airway emergencies. We report the characteristics, indications, and outcomes of these activations that occur in the pediatric emergency department (PED). METHODS: Retrospective, single-center cohort study comprised all difficult airway team activations occurring in the PED from the program's inception in 2008 to 2018. Ages of ≤18 years were included. For each case, detailed information was abstracted, including patient factors, PED context and milieu, airway interventions, and airway outcomes. RESULTS: There were 15 difficult airway response team activations in the PED during the study period, or 1.4 activations per year. The most common indications for activation were contaminated airways (n = 7; 47%) and history of difficult intubation (n = 4; 27%). Definitive airway management was successful in all cases, except for a single case where intervention was unnecessary. The most commonly performed definitive airway intervention was direct laryngoscopy (n = 6; 40%). There were no instances of emergency front-of-neck access. CONCLUSIONS: Difficult airways in the PED were uncommon. Most cases were resolved with familiar equipment including direct laryngoscopy, video laryngoscopy, and supraglottic airways.

A Modified Injector and Sample Acquisition Protocol Can Improve Data Quality and Reduce Inter-Instrument Variability of the Helios Mass Cytometer.

Mass cytometry is a powerful tool for high-dimensional single cell characterization. Since the introduction of the first commercial CyTOF mass cytometer by DVS Sciences in 2009, mass cytometry technology has matured and become more widely utilized, with sequential platform upgrades designed to address specific limitations and to expand the capabilities of the platform. Fluidigm's third-generation Helios mass cytometer introduced a number of upgrades over the previous CyTOF2. One of these new features is a modified narrow bore sample injector that generates smaller ion clouds, which is expected to improve sensitivity and throughput. However, following rigorous testing, we find that the narrow-bore sample injector may have unintended negative consequences on data quality and result in lower median and higher coefficients of variation in many antibody-associated signal intensities. We describe an alternative Helios acquisition protocol using a wider bore injector, which largely mitigates these data quality issues. We directly compare these two protocols in a multisite study of 10 Helios instruments across 7 institutions and show that the modified protocol improves data quality and reduces interinstrument variability. These findings highlight and address an important source of technical variability in mass cytometry experiments that is of particular relevance in the setting of multicenter studies. © 2019 International Society for Advancement of Cytometry.

Heterotopic Purkinje Cells: a Comparative Postmortem Study of Essential Tremor and Spinocerebellar Ataxias 1, 2, 3, and 6.

Essential tremor (ET) is among the most common neurological diseases. Postmortem studies have noted a series of pathological changes in the ET cerebellum. Heterotopic Purkinje cells (PCs) are those whose cell body is mis-localized in the molecular layer. In neurodegenerative settings, these are viewed as a marker of the progression of neuronal degeneration. We (1) quantify heterotopias in ET cases vs. controls, (2) compare ET cases to other cerebellar degenerative conditions (spinocerebellar ataxias (SCAs) 1, 2, 3, and 6), (3) compare these SCAs to one another, and (4) assess heterotopia within the context of associated PC loss in each disease. Heterotopic PCs were quantified using a standard LH&E-stained section of the neocerebellum. Counts were normalized to PC layer length (n-heterotopia count). It is also valuable to consider PC counts when assessing heterotopia, as loss of PCs extends both to normally located as well as heterotopic PCs. Therefore, we divided n-heterotopias by PC counts. There were 96 brains (43 ET, 31 SCA [12 SCA1, 7 SCA2, 7 SCA3, 5 SCA6], and 22 controls). The median number of n-heterotopias in ET cases was two times higher than that of the controls (2.6 vs. 1.2, p < 0.05). The median number of n-heterotopias in the various SCAs formed a spectrum, with counts being highest in SCA3 and SCA1. In analyses that factored in PC counts, ET had a median n-heterotopia/Purkinje cell count that was three times higher than the controls (0.35 vs. 0.13, p < 0.01), and SCA1 and SCA2 had counts that were 5.5 and 11 times higher than the controls (respective p < 0.001). The median n-heterotopia/PC count in ET was between that of the controls and the SCAs. Similarly, the median PC count in ET was between that of the controls and the SCAs; the one exception was SCA3, in which the PC population is well known to be preserved. Heterotopia is a disease-associated feature of ET. In comparison, several of the SCAs evidenced even more marked heterotopia, although a spectrum existed across the SCAs. The median n-heterotopia/PC count and median PC in ET was between that of the controls and the SCAs; hence, in this regard, ET could represent an intermediate state or a less advanced state of spinocerebellar atrophy.

Cyclical Abdominal Pain in an Adolescent Female: A Case Report of Agenesis of the Lower Vagina.

Congenital agenesis of the lower vagina is a rare disorder characterized by separation between the unaffected proximal vagina and the distal vagina by a band of fibrous tissue. The typical presentation is an early adolescent female with chronic, cyclic abdominal pain and primary amenorrhea. In this case report, we describe an adolescent who presented to the pediatric emergency department on 2 occasions with a chief complaint of lower abdominal pain.

Climbing fiber-Purkinje cell synaptic pathology in tremor and cerebellar degenerative diseases.

Changes in climbing fiber-Purkinje cell (CF-PC) synaptic connections have been found in the essential tremor (ET) cerebellum, and these changes are correlated with tremor severity. Whether these postmortem changes are specific to ET remains to be investigated. We assessed CF-PC synaptic pathology in the postmortem cerebellum across a range of degenerative movement disorders [10 Parkinson's disease (PD) cases, 10 multiple system atrophy (MSA) cases, 10 spinocerebellar ataxia type 1 (SCA1) cases, and 20 ET cases] and 25 controls. We observed differences in terms of CF pathological features across these disorders. Specifically, PD cases and ET cases both had more CFs extending into the parallel fiber (PF) territory, but ET cases had more complex branching and increased length of CFs in the PF territory along with decreased CF synaptic density compared to PD cases. MSA cases and SCA1 cases had the most severely reduced CF synaptic density and a marked paucity of CFs extending into the PF territory. Furthermore, CFs in a subset of MSA cases formed collateral branches parallel to the PC layer, a feature not seen in other diagnostic groups. Using unsupervised cluster analysis, the cases and controls could all be categorized into four clusters based on the CF pathology and features of PC pathology, including counts of PCs and their axonal torpedoes. ET cases and PD cases co-segregated into two clusters, whereas SCA1 cases and MSA cases formed another cluster, separate from the control cluster. Interestingly, the presence of resting tremor seemed to be the clinical feature that separated the cases into the two ET-PD clusters. In conclusion, our study demonstrates that these degenerative movement disorders seem to differ with respect to the pattern of CF synaptic pathology they exhibit. It remains to be determined how these differences contribute to the clinical presentations of these diseases.

Cerebellar Pathology in Familial vs. Sporadic Essential Tremor.

Familial and sporadic essential tremor (ET) cases differ in several respects. Whether they differ with respect to cerebellar pathologic changes has yet to be studied. We quantified a broad range of postmortem features (Purkinje cell (PC) counts, PC axonal torpedoes, a host of associated axonal changes, heterotopic PCs, and hairy basket ratings) in 60 ET cases and 30 controls. Familial ET was defined using both liberal criteria (n = 27) and conservative criteria (n = 20). When compared with controls, ET cases had lower PC counts, more torpedoes, more heterotopic PCs, a higher hairy basket rating, an increase in PC axonal collaterals, an increase in PC thickened axonal profiles, and an increase in PC axonal branching. Familial and sporadic ET had similar postmortem changes, with few exceptions, regardless of the definition criteria. The PC counts were marginally lower in familial than sporadic ET (respective p values = 0.059 [using liberal criteria] and 0.047 [using conservative criteria]). The PC thickened axonal profile count was marginally lower in familial ET than sporadic ET (respective p values = 0.037 [using liberal criteria] and 0.17 [using conservative criteria]), and the PC axonal branching count was marginally lower in familial than sporadic ET (respective p values = 0.045 [using liberal criteria] and 0.079 [using conservative criteria]). After correction for multiple comparisons, however, there were no significant differences. Overall, familial and sporadic ET cases share very similar cerebellar postmortem features. These data indicate that pathological changes in the cerebellum are a part of the pathophysiological cascade of events in both forms of ET.

Cerebellar Pathology in Early Onset and Late Onset Essential Tremor.

Early onset and late onset essential tremor (ET) cases differ in several respects. Whether they differ with respect to cerebellar pathologic changes remains to be determined. We quantified a broad range of postmortem features (Purkinje cell (PC) counts, PC axonal torpedoes and associated axonal changes, heterotopic PCs, and hairy basket ratings) in 30 ET cases with age of tremor onset <50 years, 30 ET cases with age of tremor onset ≥50 years, and 30 controls (total n = 90). We also used two alternative age of onset cut-points (<40 vs. ≥40 years, and <60 vs. ≥60 years) to define early onset vs. late onset ET. We found that ET cases with tremor onset <50 years and tremor onset ≥50 years had similar PC counts (8.78 ± 1.70 vs. 8.86 ± 1.24, p = 0.839), PC axonal torpedo counts (17.87 ± 18.27 [median =13.00] vs. 12.90 ± 10.60 [median =9.0], p = 0.486) and associated axonal pathology (all p values >0.05), heterotopic PC counts (9.90 ± 11.55 [median =6.00] vs. 5.40 ± 5.10 [median =3.50], p = 0.092), and hairy basket ratings (1.95 ± 0.62 [median =2.00] vs. 2.05 ± 0.92 [median =2.00], p = 0.314). When using the age of onset cut-points of 40 or 60 years, results were similar. Early onset and late onset ET cases share similar cerebellar postmortem features. These data do not support the notion that these age-of-onset related forms of ET represent distinct clinical-pathological entities.

Evidence for a quadruplex structure in the polymorphic hs1.2 enhancer of the immunoglobulin heavy chain 3' regulatory regions and its conservation in mammals.

Regulatory regions in the genome can act through a variety of mechanisms that range from the occurrence of histone modifications to the presence of protein-binding loci for self-annealing sequences. The final result is often the induction of a conformational change of the DNA double helix, which alters the accessibility of a region to transcription factors and consequently gene expression. A ∼300 kb regulatory region on chromosome 14 at the 3' end (3'RR) of immunoglobulin (Ig) heavy-chain genes shows very peculiar features, conserved in mammals, including enhancers and transcription factor binding sites. In primates, the 3'RR is present in two copies, both having a central enhancer named hs1.2. We previously demonstrated the association between different hs1.2 alleles and Ig plasma levels in immunopathology. Here, we present the analysis of a putative G-quadruplex structure (tetraplex) consensus site embedded in a variable number tandem repeat (one to four copies) of hs1.2 that is a distinctive element among the enhancer alleles, and an investigation of its three-dimensional structure using bioinformatics and spectroscopic approaches. We suggest that both the role of the enhancer and the alternative effect of the hs1.2 alleles may be achieved through their peculiar three-dimensional-conformational rearrangement. © 2016 Wiley Periodicals, Inc. Biopolymers 105: 768-778, 2016.

Mapping Purkinje Cell Placement Along the Purkinje Cell Layer: an Analysis of Postmortem Tissue from Essential Tremor Patients vs. Controls.

Postmortem studies have reported Purkinje cell loss in essential tremor (ET), and we recently demonstrated a significant increase in the mean distance between Purkinje cell bodies (i.e., a larger gap length distance) in ET cases vs. controls, likely reflecting a disease-associated reduction in Purkinje cells. We now analyze the regularity of distribution of Purkinje cells along the Purkinje cell layer to determine whether there is greater disorganization in ET cases than in age-matched controls. A standard parasagittal, formalin-fixed, tissue block was harvested from the neocerebellum of 50 ET cases and 25 age-matched controls. The gap length distance (µm) between Purkinje cells was quantified using a nearest neighbor analysis in which the distance between each Purkinje cell body was measured in OpenLAB software, version 5 (Improvision, Waltham, MA) by drawing a freehand line between adjacent Purkinje cell bodies along the entirety of the Purkinje cell layer within a given image. We analyzed the subject-specific variation in the organization of Purkinje cells along the Purkinje cell layer. The 50 ET cases and 25 controls were similar in age at death, gender, and brain weight. Overall, greater variation in gap length distance (i.e., more disorganization) was associated with greater gap length distance (p < 0.001) and younger age (p = 0.020). However, the variation in the Purkinje cell gap length distance (i.e., Purkinje cell organization) did not differ in ET cases and controls (p = 0.330). We observed that the regularity of the distribution of Purkinje cells along the Purkinje cell layer did not differ between ET cases and controls. Several alternative biological interpretations for this finding are discussed.

Iberdomide increases innate and adaptive immune cell subsets in the bone marrow of patients with relapsed/refractory multiple myeloma.

Iberdomide is a potent cereblon E3 ligase modulator (CELMoD agent) with promising efficacy and safety as a monotherapy or in combination with other therapies in patients with relapsed/refractory multiple myeloma (RRMM). Using a custom mass cytometry panel designed for large-scale immunophenotyping of the bone marrow tumor microenvironment (TME), we demonstrate significant increases of effector T and natural killer (NK) cells in a cohort of 93 patients with multiple myeloma (MM) treated with iberdomide, correlating findings to disease characteristics, prior therapy, and a peripheral blood immune phenotype. Notably, changes are dose dependent, associated with objective response, and independent of prior refractoriness to MM therapies. This suggests that iberdomide broadly induces innate and adaptive immune activation in the TME, contributing to its antitumor efficacy. Our approach establishes a strategy to study treatment-induced changes in the TME of patients with MM and, more broadly, patients with cancer and establishes rational combination strategies for iberdomide with immune-enhancing therapies to treat MM.

Tumor-immune signatures of treatment resistance to brentuximab vedotin with ipilimumab and/or nivolumab in Hodgkin lymphoma.

PURPOSE: To investigate the cellular and molecular mechanisms associated with targeting CD30-expressing Hodgkin Lymphoma (HL) and immune checkpoint modulation induced by combination therapies of CTLA-4 and PD1. PATIENTS AND METHODS: Phase 1/2, multicenter, open-label, trial NCT01896999 enrolled patients with refractory or relapsed HL (R/R HL) after one or more lines of therapy, with adequate performance status and organ function. Using peripheral blood, we assessed soluble proteins, cell composition, T cell clonality, and tumor antigen-specific antibodies in 54 patients enrolled in the phase 1 component of the trial. RESULTS: NCT01896999 reported high (>75%) overall objective response rates with brentuximab-vedotin (BV) in combination with ipilimumab (I) and/or nivolumab (N) in patients with R/R HL. We observed durable increase in soluble PD-1 and plasmacytoid dendritic cells as well as decreases in plasma CCL17, ANGPT2, MMP12, IL13, and CXCL13 in N-containing regimens (BV+N and BV+I+N) compared with BV+I (p<0.05). Non-responders and patients with short progression free-survival showed elevated CXCL9, CXCL13, CD5, CCL17, adenosine-deaminase, and MUC16 at baseline or after one treatment cycle and a higher prevalence of NY-ESO-1-specific autoantibodies (p<0.05). CONCLUSIONS: The results suggest a circulating tumor-immune-derived signature of BV±I+N treatment resistance that may be useful for patient stratification in combination checkpoint therapy.

A Phase II Open-Label Randomized Clinical Trial of Preoperative Durvalumab or Durvalumab plus Tremelimumab in Resectable Head and Neck Squamous Cell Carcinoma.

PURPOSE: Clinical implications of neoadjuvant immunotherapy in patients with locally advanced but resectable head and neck squamous cell carcinoma (HNSCC) remain largely unexplored. PATIENTS AND METHODS: Patients with resectable HNSCC were randomized to receive a single dose of preoperative durvalumab (D) with or without tremelimumab (T) before resection, followed by postoperative (chemo)radiotherapy based on multidisciplinary discretion and 1-year D treatment. Artificial intelligence (AI)-powered spatial distribution analysis of tumor-infiltrating lymphocytes and high-dimensional profiling of circulating immune cells tracked dynamic intratumoral and systemic immune responses. RESULTS: Of the 48 patients enrolled (D, 24 patients; D+T, 24 patients), 45 underwent surgical resection per protocol (D, 21 patients; D+T, 24 patients). D±T had a favorable safety profile and did not delay surgery. Distant recurrence-free survival (DRFS) was significantly better in patients treated with D+T than in those treated with D monotherapy. AI-powered whole-slide image analysis demonstrated that D+T significantly reshaped the tumor microenvironment toward immune-inflamed phenotypes, in contrast with the D monotherapy or cytotoxic chemotherapy. High-dimensional profiling of circulating immune cells revealed a significant expansion of T-cell subsets characterized by proliferation and activation in response to D+T therapy, which was rare following D monotherapy. Importantly, expansion of specific clusters in CD8+ T cells and non-regulatory CD4+ T cells with activation and exhaustion programs was associated with prolonged DRFS in patients treated with D+T. CONCLUSIONS: Preoperative D±T is feasible and may benefit patients with resectable HNSCC. Distinct changes in the tumor microenvironment and circulating immune cells were induced by each treatment regimen, warranting further investigation.

High-flow nasal cannula use in children with respiratory distress in the emergency department: predicting the need for subsequent intubation.

BACKGROUND: High-flow nasal cannula (HFNC) is a safe, well-tolerated, and noninvasive method of respiratory support that has seen increasing use in the care of children with respiratory distress. High-flow nasal cannula may be able to prevent intubations in infants and children with respiratory distress. OBJECTIVE: The objective of this study was to determine the clinical and patient characteristics that predict success or failure of HFNC therapy in children presenting to the pediatric emergency department (PED) with respiratory distress. DESIGN/METHODS: A retrospective cohort review was conducted of all children younger than 2 years evaluated in 2 PEDs between June 2011 and September 2012 who received HFNC therapy within 24 hours of initial triage. Data extraction included clinical variables, demographic variables, and patient outcomes. Therapy failure was defined as the clinical decision to intubate a patient after an antecedent trial of HFNC. Multivariable logistic regression was performed to identify factors associated with intubation following HFNC. RESULTS: Four hundred ninety-eight cases meeting criteria for inclusion were identified. The most common final diagnosis was acute bronchiolitis (n = 231, 46%), followed by pneumonia (n = 138, 28%) and asthma (n = 38, 8%). Of the 498 patients, 42 (8%) of patients failed therapy and required intubation following HFNC trial. Risk factors associated with HFNC failure were triage respiratory rate greater than 90th percentile for age (odds ratio [OR], 2.11; 95% confidence interval [CI], 1.01-4.43), initial venous PCO2 greater than 50 mm Hg (OR, 2.51; 95% CI, 1.06-5.98), and initial venous pH less than 7.30 (OR, 2.53; 95% CI, 1.12-5.74). A final diagnosis of bronchiolitis was observed to be protective with respect to intubation (OR, 0.40; 95% CI, 0.17-0.96). CONCLUSIONS: In infants with all-cause respiratory distress presenting in the PED, triage respiratory rate greater than 90th percentile for age, initial venous PCO2 greater than 50 mm Hg, and initial venous pH less than 7.30 were associated with failure of HFNC therapy. A diagnosis of acute bronchiolitis was protective with respect to intubation following HFNC. This finding may help guide clinicians who use HFNC by identifying a patient population at higher risk of failing therapy.