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Summary: Skeletal muscle generation of ammonia, an endogenous cytotoxin, is increased during exercise. Perturbations in ammonia metabolism consistently occur in chronic diseases, and may blunt beneficial skeletal muscle molecular responses and protein homeostasis with exercise. Phosphorylation of skeletal muscle proteins mediates cellular signaling responses to hyperammonemia and exercise. Comparative bioinformatics and machine learning-based analyses of published and experimentally derived phosphoproteomics data identified differentially expressed phosphoproteins that were unique and shared between hyperammonemic murine myotubes and skeletal muscle from exercise models. Enriched processes identified in both hyperammonemic myotubes and muscle from exercise models with selected experimental validation included protein kinase A (PKA), calcium signaling, mitogen-activated protein kinase (MAPK) signaling, and protein homeostasis. Our approach of feature extraction from comparative untargeted “omics” data allows for selection of preclinical models that recapitulate specific human exercise responses and potentially optimize functional capacity and skeletal muscle protein homeostasis with exercise in chronic diseases.

Pancreatic neuroendocrine tumors (PanNETs) represent a morphologically heterogeneous group which can prove challenging for pathologists to diagnose by cytology. The index case was initially misdiagnosed on an endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) as metastatic pancreatic adenocarcinoma with signet ring cell morphology; however, the resected surgical pathology specimen was histologically and immunohistochemically compatible with a well-differentiated neuroendocrine tumor with rhabdoid features. In light of the resection specimen, the cytopathology specimen was reviewed, with the spectrum of morphology appreciated in retrospect. This case prompted a search within our institution for challenging cases that highlight the gamut of PanNET morphologies. In this series, the cases presented highlight benign mimickers, rare diagnoses, differential diagnostic considerations, and the overlapping morphologies that PanNETs can exhibit in cytology specimens with comparison to their surgical counterparts. Specific importance is placed on morphology and immunohistochemistry to distinguish between PanNET and the differential diagnoses of ductal adenocarcinoma, clear cell variant of PanNET, neuroendocrine carcinoma, solid pseudopapillary neoplasm, and acinar cell carcinoma, as well as islet cell hyperplasia and nesidioblastosis, with important attention to interpretation of paucicellular specimen. Furthermore, we provide a review of immunohistochemical studies in cases where morphology is especially challenging.

Numbers don't speak for themselves – yet taking numbers for granted (numerism) is widespread. In fact, journalists often rely heavily on numbers precisely because they are widely considered objective. As a team of journalists and social scientists, we undertook a qualitative exploration of clauses and entire news reports that are particularly quantitatively dense. The dense clauses were often grammatically complex and assumed familiarity with sophisticated concepts. They were rarely associated with explanations of data collection methods. Meanwhile, the dense news reports were all about economy or health topics, chiefly brief updates on an ongoing event (e.g., stock market fluctuations; COVID-19 cases). We suggest that journalists can support public understanding by: Providing more detail about research methods; Writing shorter, clearer sentences; Providing context behind statistics; Being transparent about uncertainty; and Indicating where consensus lies. We also encourage news organizations to consider structural changes like rethinking their relationship with newswires and working closely with statisticians. [ABSTRACT FROM AUTHOR]

Objective: Commonly used terms like "obese person" have been identified as stigmatizing by those with lived experience. Thus, this study sought to revise a commonly used measure of weight stigmatizing attitudes, the Attitudes Toward Obese Persons (ATOP) scale. Methods: The original terminology in the 20‐item ATOP (e.g., "obese") was compared to a modified version using neutral terms (e.g., "higher weight"). Participants (N = 832) were randomized to either receive the original or modified ATOP. Results: There was a statistically significant difference, with a small effect size (d = −0.22), between the scores of participants who received the original ATOP (M = 69.25) and the modified ATOP (M = 72.85), t(414) = −2.27, p = 0.024. Through principal component analysis, the modified ATOP was best used as a brief, 8‐item unidimensional measure. In a second sample, confirmatory factor analysis verified the fit of the brief, 8‐item factor structure. Conclusions: Findings suggest that a modified, brief version of the ATOP (ATOP‐Heigher Weight; ATOP‐HW) with neutral language is suitable for assessing negative attitudes about higher‐weight people. The ATOP‐HW may slightly underestimate weight stigma compared to the original ATOP, or the language in the ATOP may magnify negative attitudes. Further examination of the terminology used in weight stigma measures is needed to determine how to best assess weight stigma without reinforcing stigmatizing attitudes. The present study's findings suggest that the use of neutral terms in measures of anti‐fat bias is a promising solution that warrants further investigation. [ABSTRACT FROM AUTHOR]

Transceptors, solute transporters that facilitate intracellular entry of molecules and also initiate intracellular signaling events, have been primarily studied in lower-order species. Ammonia, a cytotoxic endogenous metabolite, is converted to urea in hepatocytes for urinary excretion in mammals. During hyperammonemia, when hepatic metabolism is impaired, nonureagenic ammonia disposal occurs primarily in skeletal muscle. Increased ammonia uptake in skeletal muscle is mediated by a membrane-bound, 12 transmembrane domain solute transporter, Rhesus blood group-associated B glycoprotein (RhBG). We show that in addition to its transport function, RhBG interacts with myeloid differentiation primary response-88 (MyD88) to initiate an intracellular signaling cascade that culminates in activation of NFκB. We also show that ammonia-induced MyD88 signaling is independent of the canonical toll-like receptor-initiated mechanism of MyD88-dependent NFκB activation. In silico, in vitro, and in situ experiments show that the conserved cytosolic J-domain of the RhBG protein interacts with the Toll-interleukin-1 receptor (TIR) domain of MyD88. In skeletal muscle from human patients, human-induced pluripotent stem cell-derived myotubes, and myobundles show an interaction of RhBG-MyD88 during hyperammonemia. Using complementary experimental and multiomics analyses in murine myotubes and mice with muscle-specific RhBG or MyD88 deletion, we show that the RhBG-MyD88 interaction is essential for the activation of NFkB but not ammonia transport. Our studies show a paradigm of substrate-dependent regulation of transceptor function with the potential for modulation of cellular responses in mammalian systems by decoupling transport and signaling functions of transceptors. [ABSTRACT FROM AUTHOR]

Ammonia is a cytotoxic metabolite with pleiotropic molecular and metabolic effects, including senescence induction. During dysregulated ammonia metabolism, which occurs in chronic diseases, skeletal muscle becomes a major organ for nonhepatocyte ammonia uptake. Muscle ammonia disposal occurs in mitochondria via cataplerosis of critical intermediary metabolite α-ketoglutarate, a senescence-ameliorating molecule. Untargeted and mitochondrially targeted data were analyzed by multiomics approaches. These analyses were validated experimentally to dissect the specific mitochondrial oxidative defects and functional consequences, including senescence. Responses to ammonia lowering in myotubes and in hyperammonemic portacaval anastomosis rat muscle were studied. Whole-cell transcriptomics integrated with whole-cell, mitochondrial, and tissue proteomics showed distinct temporal clusters of responses with enrichment of oxidative dysfunction and senescence-related pathways/proteins during hyperammonemia and after ammonia withdrawal. Functional and metabolic studies showed defects in electron transport chain complexes I, III, and IV; loss of supercomplex assembly; decreased ATP synthesis; increased free radical generation with oxidative modification of proteins/lipids; and senescence-associated molecular phenotype–increased β-galactosidase activity and expression of p16INK, p21, and p53. These perturbations were partially reversed by ammonia lowering. Dysregulated ammonia metabolism caused reversible mitochondrial dysfunction by transcriptional and translational perturbations in multiple pathways with a distinct skeletal muscle senescence-associated molecular phenotype.

B cells play a significant role in the adaptive immune response by secreting immunoglobulins that can recognize and neutralize foreign antigens. They develop from hematopoietic stem cells, which also give rise to other types of blood cells, such as monocytes, neutrophils, and T cells, wherein specific transcriptional programs define the commitment and subsequent development of these different cell lineages. A number of transcription factors, such as PU.1, E2A, Pax5, and FOXO1, drive B cell development. Mounting evidence demonstrates that non-coding RNAs, such as microRNAs (miRNAs) and long non-coding RNAs (lncRNAs), modulate the expression of these transcription factors directly by binding to the mRNA coding for the transcription factor or indirectly by modifying cellular pathways that promote expression of the transcription factor. Conversely, these transcription factors upregulate expression of some miRNAs and lncRNAs to determine cell fate decisions. These studies underscore the complex gene regulatory networks that control B cell development during hematopoiesis and identify new regulatory RNAs that require additional investigation. In this review, we highlight miRNAs and lncRNAs that modulate the expression and activity of transcriptional regulators of B lymphopoiesis and how they mediate this regulation.

B cells produce high-affinity immunoglobulins (Igs), or antibodies, to eliminate foreign pathogens. Mature, naïve B cells expressing an antigen-specific cell surface Ig, or B cell receptor (BCR), are directed toward either an extrafollicular (EF) or germinal center (GC) response upon antigen binding. B cell interactions with CD4+ pre-T follicular helper (pre-Tfh) cells at the T-B border and effector Tfh cells in the B cell follicle and GC control B cell development in response to antigen. Here, we review recent studies demonstrating the role of B cell receptor (BCR) affinity in modulating T-B interactions and the subsequent differentiation of B cells in the EF and GC response. Overall, these studies demonstrate that B cells expressing high affinity BCRs preferentially differentiate into antibody secreting cells (ASCs) while those expressing low affinity BCRs undergo further affinity maturation or differentiate into memory B cells (MBCs).

Amy Attaway,1,2 Uddalak Majumdar,1,3 Robert A Sandhaus,4,5 Amy S Nowacki,6 James K Stoller2,7 1Cleveland Clinic Lerner School of Medicine, Cleveland, OH, USA; 2Respiratory Institute, Cleveland Clinic, Cleveland, OH, USA; 3Department of Hospital Medicine, Cleveland Clinic, Cleveland, OH, USA; 4Alpha-1 Antitrypsin Deficiency Program, National Jewish Health, Denver, CO, USA; 5Alpha-1 Foundation, Coral Gables, FL, USA; 6Department of Quantitative Health Sciences, Lerner Research Institute, Cleveland Clinic, Cleveland, OH, USA; 7Education Institute, Cleveland Clinic, Cleveland, OH, USACorrespondence: Amy AttawayRespiratory Institute, Cleveland Clinic, 9500 Euclid Avenue, Cleveland, OH 44195, USATel +1 216 445 2807Email attawaa@cc.orgBackground: Practice guidelines (PGs) attempt to standardize practice to optimize care. For uncommon lung diseases like alpha-1 antitrypsin deficiency (AATD), a paucity of definitive studies and geographic variation in prevalence may hamper guideline generation. The current study assembled and assesses the degree of concordance among available PGs regarding AATD.Methods: To assess concordance, 15 eligible guidelines focused on AATD were evaluated regarding recommendations surrounding 24 key clinical issues. A Delphi process achieved consensus on ratings for each statement among 3 reviewers. Agreement was quantified as the proportion of guideline comparisons with a matching rating.Results: The overall level of agreement was 47% (1190/2520 comparisons). The overall “affirmative agreement percentage” (ie, when guidelines agreed in endorsing a practice), was 42% (501/1190 comparisons). The agreement for individual clinical statements ranged from 26% to 75%. A broad consensus was seen in the recommendation to test all patients with a history of fixed obstruction on pulmonary function testing (either from asthma or COPD). Given that AATD is an under-recognized disease and that diagnosis often occurs at a late stage, the authors are encouraged by this consensus. Where overall the guidelines were less explicit was when to refer to a specialist or AATD center. Deciding on a treatment strategy requires a thorough understanding of the alpha 1 serum level, genotype, pulmonary function testing, and imaging, and therefore the authors feel that all patients would benefit from a specialty referral if the diagnosis of AATD is being considered.Conclusion: Available guidelines regarding AATD frequently disagreed in management recommendations. Possible explanations for discordance include differences in regional prevalence, availability of augmentation therapy, and insurance environments. Attempts to harmonize the various guidelines by empaneling a broadly representative international group of disease experts should be considered for AATD. Similar comparisons among guidelines for other diseases are recommended.Keywords: alpha-1 antitrypsin deficiency, practice guidelines, chronic obstructive pulmonary disease, clinical management

Inhaled Corticosteroids (ICS) are commonly prescribed to patients with severe COPD and recurrent exacerbations. It is not known what impact ICS cause in terms of COVID-19 positivity or disease severity in COPD. This study examined 27,810 patients with COPD from the Cleveland Clinic COVID-19 registry between March 8th and September 16th, 2020. Electronic health records were used to determine diagnosis of COPD, ICS use, and clinical outcomes. Multivariate logistic regression was used to adjust for demographics, month of COVID-19 testing, and comorbidities known to be associated with increased risk for severe COVID-19 disease. Amongst the COPD patients who were tested for COVID-19, 44.1% of those taking an ICS-containing inhaler tested positive for COVID-19 versus 47.2% who tested negative for COVID-19 (p = 0.033). Of those who tested positive for COVID-19 (n = 1288), 371 (28.8%) required hospitalization. In-hospital outcomes were not significantly different when comparing ICS versus no ICS in terms of ICU admission (36.8% [74/201] vs 31.2% [53/170], p = 0.30), endotracheal intubation (21.9% [44/201] vs 16.5% [28/170], p = 0.24), or mortality (18.4% [37/201] vs 20.0% [34/170], p = 0.80). Multivariate logistic regression demonstrated no significant differences in hospitalization (adj OR 1.12, CI: 0.90-1.38), ICU admission (adj OR: 1.31, CI: 0.82-2.10), need for mechanical ventilation (adj OR 1.65, CI: 0.69-4.02), or mortality (OR: 0.80, CI: 0.43-1.49). In conclusion, ICS therapy did not increase COVID-19 related healthcare utilization or mortality outcome in patients with COPD followed at the Cleveland Clinic health system. These findings should encourage clinicians to continue ICS therapy for COPD patients during the COVID-19 pandemic.

Background: We sought to determine whether COPD conferred a higher risk for healthcare utilization in terms of hospitalization and clinical outcomes due to COVID-19. Methods: A cohort study with covariate adjustment using multivariate logistic regression was conducted at the Cleveland Clinic Health System in Ohio and Florida. Symptomatic patients aged 35 years and older who were tested for SARS-CoV-2 between March 8 and May 13, 2020 were included. Findings: 15,586 individuals tested for COVID-19 at the Cleveland Clinic between March 8, 2020 and May 13, 2020 met our inclusion criteria. 12.4% of COPD patients (164/1319) tested positive for COVID-19 compared to 16.6% (2363/14,267) of the non-COPD population. 48.2% (79/164) of COVID-19 positive COPD patients required hospitalization and 45.6% (36/79) required ICU admission. After adjustment for covariates, rates of COVID-19 infection were not significantly different than the non-COPD population (adj OR 0.97; CI: 0.89–1.05), but COPD patients had increased healthcare utilization as demonstrated by risk for hospitalization (adj OR 1.36; CI: 1.15–1.60), ICU admission (OR 1.20; CI: 1.02–1.40), and need for invasive mechanical ventilation (adj OR 1.49; CI: 1.28–1.73). Unadjusted risk for in-hospital mortality was higher in the COPD population (OR 1.51; CI: 1.14–1.96). After adjusting for covariates however, the risk for in-hospital mortality was not significantly different than the non-COPD population (adj OR 1.08: CI: 0.81–1.42). Interpretation: Our analysis demonstrated that COPD patients with COVID-19 had a higher risk for healthcare utilization, although adjusted in-hospital mortality risk was not different than the non-COPD patients with COVID-19.