Outcomes and Adverse Effects of Baricitinib Versus Tocilizumab in the Management of Severe COVID-19.

OBJECTIVES: The National Institutes of Health and Infectious Diseases Society of America guidelines recommend tocilizumab or baricitinib in the management of severe COVID-19. Despite clinical trials on the individual agents, there are no large-scale studies comparing the two agents to guide the selection of one versus the other. The purpose of this study was to compare the outcomes and adverse effects of baricitinib versus tocilizumab in the management of severe COVID-19. DESIGN: Retrospective, observational cohort study. SETTING: Eleven acute care hospitals in a large health system in Georgia. PATIENTS: Adult patients with severe COVID-19 who received at least one dose of either baricitinib or tocilizumab between June 2021 and October 2021. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: The primary outcome was in-hospital mortality. The key secondary outcome was occurrence rate of adverse effects. A total of 956 patients were identified. The median age was 57 years, and 53% were of male sex. The median body mass index was 33.5, and more than 94% of the population was unvaccinated. Propensity score matching by baseline characteristics resulted in a total of 582 patients, 291 in each group. There was no difference in mortality between the two groups; however, the occurrence rate of adverse effects was significantly higher in the tocilizumab group compared with baricitinib: secondary infections (32% vs 22%; p < 0.01); thrombotic events (24% vs 16%; p < 0.01); and acute liver injury (8% vs 3%; p < 0.01). CONCLUSIONS: Our propensity score-matched, retrospective, observational study in patients hospitalized with severe COVID-19 showed no difference in mortality but significantly fewer adverse effects with baricitinib compared with tocilizumab. Our data suggest that baricitinib may be a better choice when treating patients with severe COVID-19, but additional prospective, randomized trials are needed to help clinicians choose the most optimal drug.

Structure-Activity Relationship of Lower Chlorinated Biphenyls and Their Human-Relevant Metabolites for Astrocyte Toxicity.

Exposure to polychlorinated biphenyls (PCBs) is associated with developmental neurotoxicity and neurodegenerative disorders; however, the underlying mechanisms of pathogenesis are unknown. Existing literature has focused mainly on using neurons as a model system to study mechanisms of PCB-mediated neurotoxicity, overlooking the role of glial cells, such as astrocytes. As normal brain function is largely astrocyte-dependent, we hypothesize that astrocytes play an important role in PCB-mediated injury to neurons. We assessed the toxicity of two commercial PCB mixtures, Aroclor 1016 and Aroclor 1254, and a non-Aroclor PCB mixture found in residential air called the Cabinet mixture, all of which contain lower chlorinated PCBs (LC-PCBs) found in indoor and outdoor air. We further assessed the toxicity of five abundant airborne LC-PCBs and their corresponding human-relevant metabolites in vitro models of astrocytes, namely, the C6 cell line and primary astrocytes isolated from Sprague-Dawley rats and C57BL/6 mice. PCB52 and its human-relevant hydroxylated and sulfated metabolites were found to be the most toxic compounds. No significant sex-dependent cell viability differences were observed in rat primary astrocytes. Based on the equilibrium partitioning model, it was predicted that the partitioning of LC-PCBs and their corresponding metabolites in biotic and abiotic compartments of the cell culture system is structure-dependent and that the observed toxicity is consistent with this prediction. This study, for the first time, shows that astrocytes are sensitive targets of LC-PCBs and their human-relevant metabolites and that further research to identify mechanistic targets of PCB exposure in glial cells is necessary.

Prolonged Detection of SARS-CoV-2 in a Patient With the Development of New Clinical Symptoms.

We present a case of a 65-year-old woman with a persistently positive nasopharyngeal swab for severe acute respiratory syndrome coronavirus 2 PCR who developed new complications of coronavirus disease 2019 (COVID-19) 63 days from illness onset. She presented with intermittent fevers, fluctuating disorientation, gait instability, diffuse corticospinal tract signs, and acute venous thromboembolism. No alternate diagnosis was identified. This case highlights the potential for prolonged SARS-CoV-2 PCR positivity and persistent multisystem complications (particularly neurological), even after several months of initial COVID-19 diagnosis.

Early Use of Remdesivir in Patients Hospitalized With COVID-19 Improves Clinical Outcomes: A Retrospective Observational Study.

BACKGROUND: Remdesivir treatment, like most antiviral drugs, is likely to be most effective when used early in the course of coronavirus disease 2019 (COVID-19). Optimal timing of remdesivir for the treatment of COVID-19 remains unclear. OBJECTIVES: The aim of this study was to determine whether early treatment with remdesivir improves clinical outcomes: length of stay, need for mechanical ventilation, and death. METHODS: We conducted a retrospective observational study of patients hospitalized with COVID-19 who received remdesivir therapy within 10 days of symptom onset at a large health system in Georgia, United States. RESULTS: We identified a total of 475 patients. Initiation of therapy 3 days or less from first positive SARS-CoV-2 improved length of stay (15.7 days) compared with those started on therapy more than 3 days after a positive test (19.3 days) (P = 0.03). In the ≤3 day group, further reduction in length of stay was seen in those with lower oxygen requirement at baseline (P < 0.0001). Length of stay was lower in the ≤3 day group both with and without the use of corticosteroids (P = 0.0003). The odds of requiring mechanical ventilation were higher for the >3 day group compared with the ≤3 day group (odds ratio, 1.5; 95% confidence interval, 0.8-2.7), and the odds of death were higher for the >3 day group versus the ≤3 day group (odds ratio, 1.74; 95% confidence interval, 0.9-3.2). CONCLUSIONS: Our data show that early treatment with remdesivir in patients hospitalized with COVID-19 shortened length of stay.

DNA sequence templates adjacent nucleosome and ORC sites at gene amplification origins in Drosophila.

Eukaryotic origins of DNA replication are bound by the origin recognition complex (ORC), which scaffolds assembly of a pre-replicative complex (pre-RC) that is then activated to initiate replication. Both pre-RC assembly and activation are strongly influenced by developmental changes to the epigenome, but molecular mechanisms remain incompletely defined. We have been examining the activation of origins responsible for developmental gene amplification in Drosophila. At a specific time in oogenesis, somatic follicle cells transition from genomic replication to a locus-specific replication from six amplicon origins. Previous evidence indicated that these amplicon origins are activated by nucleosome acetylation, but how this affects origin chromatin is unknown. Here, we examine nucleosome position in follicle cells using micrococcal nuclease digestion with Ilumina sequencing. The results indicate that ORC binding sites and other essential origin sequences are nucleosome-depleted regions (NDRs). Nucleosome position at the amplicons was highly similar among developmental stages during which ORC is or is not bound, indicating that being an NDR is not sufficient to specify ORC binding. Importantly, the data suggest that nucleosomes and ORC have opposite preferences for DNA sequence and structure. We propose that nucleosome hyperacetylation promotes pre-RC assembly onto adjacent DNA sequences that are disfavored by nucleosomes but favored by ORC.

Astrocyte Mitochondria Are a Sensitive Target of PCB52 and its Human-Relevant Metabolites.

Polychlorinated biphenyls (PCBs) are industrial chemicals that are ubiquitously found in the environment. Exposure to these compounds has been associated with neurotoxic outcomes; however, the underlying mechanisms for such outcomes remain to be fully understood. Recent studies have shown that astrocytes, the most abundant glial cell type in the brain, are susceptible to PCB exposure as well as exposure to human-relevant metabolites of PCBs. Astrocytes are critical for maintaining healthy brain function due to their unique functional attributes and positioning within the neuronal networks in the brain. In this study, we assessed the toxicity of PCB52, one of the most abundantly found PCB congeners in outdoor and indoor air, and two of its human-relevant metabolites, on astrocyte mitochondria. We exposed C6 cells, an astrocyte cell line, to PCB52 or its human-relevant metabolites and found that all the compounds showed increased toxicity in galactose-containing media compared to that in the glucose-containing media, indicating the involvement of mitochondria in observed toxicity. Additionally, we also found increased oxidative stress upon exposure to PCB52 metabolites. All three compounds caused a loss of mitochondrial membrane potential, distinct changes in the mitochondrial structure, and impaired mitochondrial function. The hydroxylated metabolite 4-OH-PCB52 likely functions as an uncoupler of mitochondria. This is the first study to report the adverse effects of exposure to PCB52 and its human-relevant metabolites on the mitochondrial structure and function in astrocytes.

Selective dopaminergic neurotoxicity modulated by inherent cell-type specific neurobiology.

Parkinson's disease (PD) is a debilitating neurodegenerative disease affecting millions of individuals worldwide. Hallmark features of PD pathology are the formation of Lewy bodies in neuromelanin-containing dopaminergic (DAergic) neurons of the substantia nigra pars compacta (SNpc), and the subsequent irreversible death of these neurons. Although genetic risk factors have been identified, around 90 % of PD cases are sporadic and likely caused by environmental exposures and gene-environment interaction. Mechanistic studies have identified a variety of chemical PD risk factors. PD neuropathology occurs throughout the brain and peripheral nervous system, but it is the loss of DAergic neurons in the SNpc that produce many of the cardinal motor symptoms. Toxicology studies have found specifically the DAergic neuron population of the SNpc exhibit heightened sensitivity to highly variable chemical insults (both in terms of chemical structure and mechanism of neurotoxic action). Thus, it has become clear that the inherent neurobiology of nigral DAergic neurons likely underlies much of this neurotoxic response to broad insults. This review focuses on inherent neurobiology of nigral DAergic neurons and how such neurobiology impacts the primary mechanism of neurotoxicity. While interactions with a variety of other cell types are important in disease pathogenesis, understanding how inherent DAergic biology contributes to selective sensitivity and primary mechanisms of neurotoxicity is critical to advancing the field. Specifically, key biological features of DAergic neurons that increase neurotoxicant susceptibility.

Thalamocortical organoids enable in vitro modeling of 22q11.2 microdeletion associated with neuropsychiatric disorders.

Thalamic dysfunction has been implicated in multiple psychiatric disorders. We sought to study the mechanisms by which abnormalities emerge in the context of the 22q11.2 microdeletion, which confers significant genetic risk for psychiatric disorders. We investigated early stages of human thalamus development using human pluripotent stem cell-derived organoids and show that the 22q11.2 microdeletion underlies widespread transcriptional dysregulation associated with psychiatric disorders in thalamic neurons and glia, including elevated expression of FOXP2. Using an organoid co-culture model, we demonstrate that the 22q11.2 microdeletion mediates an overgrowth of thalamic axons in a FOXP2-dependent manner. Finally, we identify ROBO2 as a candidate molecular mediator of the effects of FOXP2 overexpression on thalamic axon overgrowth. Together, our study suggests that early steps in thalamic development are dysregulated in a model of genetic risk for schizophrenia and contribute to neural phenotypes in 22q11.2 deletion syndrome.

A CRISPR-engineered isogenic model of the 22q11.2 A-B syndromic deletion.

22q11.2 deletion syndrome, associated with congenital and neuropsychiatric anomalies, is the most common copy number variant (CNV)-associated syndrome. Patient-derived, induced pluripotent stem cell (iPS) models have provided insight into this condition. However, patient-derived iPS cells may harbor underlying genetic heterogeneity that can confound analysis. Furthermore, almost all available models reflect the commonly-found ~ 3 Mb "A-D" deletion at this locus. The ~ 1.5 Mb "A-B" deletion, a variant of the 22q11.2 deletion which may lead to different syndromic features, and is much more frequently inherited than the A-D deletion, remains under-studied due to lack of relevant models. Here we leveraged a CRISPR-based strategy to engineer isogenic iPS models of the 22q11.2 "A-B" deletion. Differentiation to excitatory neurons with subsequent characterization by transcriptomics and cell surface proteomics identified deletion-associated alterations in proliferation and adhesion. To illustrate in vivo applications of this model, we further implanted neuronal progenitor cells into the cortex of neonatal mice and found potential alterations in neuronal maturation. The isogenic models generated here will provide a unique resource to study this less-common variant of the 22q11.2 microdeletion syndrome.

Rhombencephalitis due to Listeria monocytogenes.

Brain stem encephalitis is an unusual form of CNS listeriosis that is associated with a high mortality. This is a case of a 46 year-old male with a history of dermatomyositis on methotrexate who presented with fever, headache, assymetrical cranial nerve palsy and right hemiparesis. MRI showed a ring-enhancing lesions in medulla oblongata. CSF cultures grew Listeria monocytogenes. Despite treatment with ampicillin and gentamicin, the patient developed three rare manifestations of neurolisteriosis namely rhombencephalitis, hydrocephalus and brainstem hemorrhage and did not survive. Early detection and treatment is vital in preventing adverse outcomes.

Paragonimiasis presenting as an acute hemorrhagic stroke.

Cerebral paragonimiasis is rare and is usually seen in younger patients. This is a case of a 19-year-old male presenting as a hemorrhagic stroke with headache and blurred vision. He was found to have cystic thick-walled spaces with focal linear tracking towards the pleural space on computed tomography of the chest. CSF analysis showed pleocytosis with 4% eosinophils. Serological testing confirmed the diagnosis of paragonimiasis. He was treated with praziquantel, corticosteroid taper and anti-epileptic medication and discharged home in stable condition. CNS paragonimiasis is treatable, has a fairly good prognosis but can often be missed. In a young person presenting with an acute hemorrhagic stroke, the possibility of paragonimiasis should be kept on the differential diagnosis.

Development and validation of a predictive model for critical illness in adult patients requiring hospitalization for COVID-19.

BACKGROUND: Identifying factors that can predict severe disease in patients needing hospitalization for COVID-19 is crucial for early recognition of patients at greatest risk. OBJECTIVE: (1) Identify factors predicting intensive care unit (ICU) transfer and (2) develop a simple calculator for clinicians managing patients hospitalized with COVID-19. METHODS: A total of 2,685 patients with laboratory-confirmed COVID-19 admitted to a large metropolitan health system in Georgia, USA between March and July 2020 were included in the study. Seventy-five percent of patients were included in the training dataset (admitted March 1 to July 10). Through multivariable logistic regression, we developed a prediction model (probability score) for ICU transfer. Then, we validated the model by estimating its performance accuracy (area under the curve [AUC]) using data from the remaining 25% of patients (admitted July 11 to July 31). RESULTS: We included 2,014 and 671 patients in the training and validation datasets, respectively. Diabetes mellitus, coronary artery disease, chronic kidney disease, serum C-reactive protein, and serum lactate dehydrogenase were identified as significant risk factors for ICU transfer, and a prediction model was developed. The AUC was 0.752 for the training dataset and 0.769 for the validation dataset. We developed a free, web-based calculator to facilitate use of the prediction model (https://icucovid19.shinyapps.io/ICUCOVID19/). CONCLUSION: Our validated, simple, and accessible prediction model and web-based calculator for ICU transfer may be useful in assisting healthcare providers in identifying hospitalized patients with COVID-19 who are at high risk for clinical deterioration. Triage of such patients for early aggressive treatment can impact clinical outcomes for this potentially deadly disease.

Surface Proteomics Reveals CD72 as a Target for In Vitro-Evolved Nanobody-Based CAR-T Cells in KMT2A/MLL1-Rearranged B-ALL.

Alternative strategies are needed for patients with B-cell malignancy relapsing after CD19-targeted immunotherapy. Here, cell surface proteomics revealed CD72 as an optimal target for poor-prognosis KMT2A/MLL1-rearranged (MLLr) B-cell acute lymphoblastic leukemia (B-ALL), which we further found to be expressed in other B-cell malignancies. Using a recently described, fully in vitro system, we selected synthetic CD72-specific nanobodies, incorporated them into chimeric antigen receptors (CAR), and demonstrated robust activity against B-cell malignancy models, including CD19 loss. Taking advantage of the role of CD72 in inhibiting B-cell receptor signaling, we found that SHIP1 inhibition increased CD72 surface density. We establish that CD72-nanobody CAR-T cells are a promising therapy for MLLr B-ALL. SIGNIFICANCE: Patients with MLLr B-ALL have poor prognoses despite recent immunotherapy advances. Here, surface proteomics identifies CD72 as being enriched on MLLr B-ALL but also widely expressed across B-cell cancers. We show that a recently described, fully in vitro nanobody platform generates binders highly active in CAR-T cells and demonstrate its broad applicability for immunotherapy development.This article is highlighted in the In This Issue feature, p. 1861.

The Histone Variant H3.3 Is Enriched at Drosophila Amplicon Origins but Does Not Mark Them for Activation.

Eukaryotic DNA replication begins from multiple origins. The origin recognition complex (ORC) binds origin DNA and scaffolds assembly of a prereplicative complex (pre-RC), which is subsequently activated to initiate DNA replication. In multicellular eukaryotes, origins do not share a strict DNA consensus sequence, and their activity changes in concert with chromatin status during development, but mechanisms are ill-defined. Previous genome-wide analyses in Drosophila and other organisms have revealed a correlation between ORC binding sites and the histone variant H3.3. This correlation suggests that H3.3 may designate origin sites, but this idea has remained untested. To address this question, we examined the enrichment and function of H3.3 at the origins responsible for developmental gene amplification in the somatic follicle cells of the Drosophila ovary. We found that H3.3 is abundant at these amplicon origins. H3.3 levels remained high when replication initiation was blocked, indicating that H3.3 is abundant at the origins before activation of the pre-RC. H3.3 was also enriched at the origins during early oogenesis, raising the possibility that H3.3 bookmarks sites for later amplification. However, flies null mutant for both of the H3.3 genes in Drosophila did not have overt defects in developmental gene amplification or genomic replication, suggesting that H3.3 is not essential for the assembly or activation of the pre-RC at origins. Instead, our results imply that the correlation between H3.3 and ORC sites reflects other chromatin attributes that are important for origin function.

Swertisin an Anti-Diabetic Compound Facilitate Islet Neogenesis from Pancreatic Stem/Progenitor Cells via p-38 MAP Kinase-SMAD Pathway: An In-Vitro and In-Vivo Study.

Transplanting islets serves best option for restoring lost beta cell mass and function. Small bio-chemical agents do have the potential to generate new islets mass, however lack of understanding about mechanistic action of these small molecules eventually restricts their use in cell-based therapies for diabetes. We recently reported "Swertisin" as a novel islet differentiation inducer, generating new beta cells mass more effectively. Henceforth, in the present study we attempted to investigate the molecular signals that Swertisin generate for promoting differentiation of pancreatic progenitors into islet cells. To begin with, both human pancreatic progenitors (PANC-1 cells) and primary cultured mouse intra-islet progenitor cells (mIPC) were used and tested for Swertisin induced islet neogenesis mechanism, by monitoring immunoblot profile of key transcription factors in time dependent manner. We observed Swertisin follow Activin-A mediated MEPK-TKK pathway involving role of p38 MAPK via activating Neurogenin-3 (Ngn-3) and Smad Proteins cascade. This MAP Kinase intervention in differentiation of cells was confirmed using strong pharmacological inhibitor of p38 MAPK (SB203580), which effectively abrogated this process. We further confirmed this mechanism in-vivo in partial pancreatectomised (PPx) mice model, where we could show Swertisin exerted potential increase in insulin transcript levels with persistent down-regulation of progenitor markers like Nestin, Ngn-3 and Pancreatic Duodenal Homeobox Gene-1 (PDX-1) expression, within three days post PPx. With detailed molecular investigations here in, we first time report the molecular mode of action of Swertisin for islet neogenesis mediated through MAP Kinase (MEPK-TKK) pathway involving Ngn-3 and Smad transcriptional regulation. These findings held importance for developing Swertisin as potent pharmacological drug candidate for effective and endogenous differentiation of islets in cell based therapy for diabetes.