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BACKGROUND AND HYPOTHESIS: The Cognitive Model of Negative Symptoms is a prominent model that posits that defeatist performance beliefs (DPB) are a key psychological mechanism underlying negative symptoms in those with schizophrenia (SZ). However, the ecological validity of the model has not been established, and temporally specific evaluations of the model's hypotheses have not been conducted. This study tested the model's key hypotheses in real-world environments using ecological momentary assessment (EMA). STUDY DESIGN: Fifty-two outpatients with SZ and 55 healthy controls (CN) completed 6 days of EMA. Multilevel models examined concurrent and time-lagged associations between DPB and negative symptoms in daily life. STUDY RESULTS: SZ displayed greater DPB in daily life than CN. Furthermore, greater DPB were associated with greater concurrently assessed negative symptoms (anhedonia, avolition, and asociality) in daily life. Time-lagged analyses indicated that in both groups, greater DPB at time t led to elevations in negative symptoms (anhedonia, avolition, or asociality) at tâ +â 1 above and beyond the effects of negative symptoms at time t. CONCLUSIONS: Results support the ecological validity of the Cognitive Model of Negative Symptoms and identify a temporally specific association between DPB and subsequent negative symptoms that is consistent with the model's hypotheses and a putative mechanistic pathway in Cognitive Behavioral Therapy for negative symptoms. Findings suggest that DPB are a psychological factor contributing to negative symptoms in real-world environments. Implications for measuring DPB in daily life and providing just-in-time mobile health-based interventions to target this mechanism are discussed.
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Introduction: Initiation of antiretroviral treatment (ART) in patients early after HIV-infection and long-term suppression leads to low or undetectable levels of HIV RNA and cell-associated (CA) HIV DNA and RNA. Both CA-DNA and CA-RNA, overestimate the size of the HIV reservoir but CA-RNA as well as p24/cell-free viral RNA can be indicators of residual viral replication. This study describes HIV RNA amounts and levels of cytokines/soluble markers in 40 well-suppressed adolescents who initiated ART early in life and investigated which viral markers may be informative as endpoints in cure clinical trials within this population. Methods: Forty adolescents perinatally infected with HIV on suppressive ART for >5 years were enrolled in the CARMA study. HIV DNA and total or unspliced CA-RNA in PBMCs were analyzed by qPCR/RT-qPCR and dPCR/RT-dPCR. Cell-free HIV was determined using an ultrasensitive viral load (US-VL) assay. Plasma markers and p24 were analyzed by digital ELISA and correlations between total and unspliced HIV RNA and clinical markers, including age at ART, Western Blot score, levels of cytokines/inflammation markers or HIV CA-DNA, were tested. Results: CA-RNA was detected in two thirds of the participants and was comparable in RT-qPCR and RT-dPCR. Adolescents with undetectable CA-RNA showed significantly lower HIV DNA compared to individuals with detectable CA-RNA. Undetectable unspliced CA-RNA was positively associated with age at ART initiation and Western Blot score. We found that a higher concentration of TNF-α was predictive of higher CA-DNA and CA-RNA. Other clinical characteristics like US-VL, time to suppression, or percent CD4+ T-lymphocytes were not predictive of the CA-RNA in this cross-sectional study. Conclusions: Low CA-DNA after long-term suppressive ART is associated with lower CA-RNA, in concordance with other reports. Patients with low CA-RNA levels in combination with low CA-DNA and low Western Blot scores should be further investigated to characterize candidates for treatment interruption trials. Unspliced CA-RNA warrants further investigation as a marker that can be prioritized in paediatric clinical trials where the sample volume can be a significant limitation.
Subject(s)
Cell-Free Nucleic Acids , HIV Infections , Humans , Adolescent , Child , Cross-Sectional Studies , RNA , Anti-Retroviral Agents/therapeutic use , Cytokines , HIV Infections/drug therapy , DNAABSTRACT
Modern HIV-1 treatment effectively suppresses viral amplification in people living with HIV. However, the persistence of HIV-1 DNA as proviruses integrated into the human genome remains the main barrier to achieving a cure. Next-generation sequencing (NGS) offers increased sensitivity for characterising archived drug resistance mutations (DRMs) in HIV-1 DNA for improved treatment options. In this study, we present an ultra-sensitive targeted PCR assay coupled with NGS and a robust pipeline to characterise HIV-1 DNA DRMs from buffy coat samples. Our evaluation supports the use of this assay for Pan-HIV-1 analyses with reliable detection of DRMs across the HIV-1 Pol region. We propose this assay as a new valuable tool for monitoring archived HIV-1 drug resistance in virologically suppressed individuals, especially in clinical trials investigating novel therapeutic approaches.
Subject(s)
Anti-HIV Agents , HIV Infections , HIV Seropositivity , HIV-1 , Humans , HIV-1/genetics , HIV Infections/drug therapy , Genotype , Drug Resistance, Viral/genetics , Anti-HIV Agents/pharmacology , Anti-HIV Agents/therapeutic use , Anti-Retroviral Agents/therapeutic use , Mutation , High-Throughput Nucleotide SequencingABSTRACT
Background: Training future doctors in the skills of evidence-based medicine (EBM) is clearly important. Journal club (JCs) are well-recognized educational interventions for teaching EBM. In contrast to postgraduate medical education, JCs use in undergraduate medical education (UME) has not been adequately explored. We conducted a realist review of the effectiveness of JCs in UME to unpack the underlying mechanisms by which the intervention works (or fails) in teaching EBM. Methods: The scope of review was the evaluation of the effectiveness of JCs in UME settings. We searched major bibliographic databases - MEDLINE, Embase, ERIC, PSYCInfo, CINAHL, Scopus, and Web of Science and found fifteen articles eligible for inclusion. Data was extracted aided by a modified Kirkpatrick framework and presented in evidence tables. Themes and chains of inference were identified, and finally, we formulated new hypotheses on how and why JC intervention works. Results: Mandatory vs. voluntary JC did not differentially impact attendance of JC in UME settings though JC duration beyond two hours decreased attendees' self-reported satisfaction. Coupling lectures to JCs positively impacts knowledge gain and retention. Coupled Mentorship or using critical appraisal worksheets helped the achievement of manuscript writing skills and a positive attitude towards EBM. Conclusions: Journal clubs are effective interventions to teach EBM in UME settings and are well-received by learners. They improve specific learning outcomes of knowledge gain and retention, skills of manuscript writing and critical appraisal. However, we found no evidence that these translates to the practice of EBM nor impacts patient outcomes.
Contexte: Il est important que les compétences enseignées aux futurs médecins soient conformes à l'approche de la médecine fondée sur les données probantes (MFDP) et les clubs de lecture (CL) sont reconnus comme une intervention pédagogique en ce sens. Le recours aux CL dans la formation prédoctorale a été peu étudié, contrairement à la place qu'ils occupent au postdoctorat. Nous avons effectué une revue réaliste de l'efficacité des CL dans la formation de premier cycle pour décortiquer les mécanismes sous-jacents qui déterminent la réussite ou l'échec de cette méthode pédagogique en ce qui a trait à l'enseignement de la MFDP. Méthodes: La revue visait l'évaluation de l'efficacité des CL dans la formation médicale prédoctroale. Nous avons effectué des recherches dans les principales banques de données bibliographiques MEDLINE, Embase, ERIC, PSYCInfo, CINAHL, Scopus et Web of Science et avons trouvé quinze articles répondant à nos critères d'inclusion. Nous avons utilisé le modèle modifié de Kirkpatrick pour la collecte de données, que nous avons présentées sous forme de tableaux de preuves. Nous avons dégagé des thèmes et élaboré des chaînes d'inférences, puis formulé de nouvelles hypothèses sur le comment et le pourquoi de l'efficacité des CL. Résultats: Le caractère obligatoire ou facultatif de l'activité n'a pas eu d'effet différentiel sur la participation des étudiants de premier cycle aux CL, mais leur satisfaction autodéclarée diminuait lorsque la durée de la séance dépassait deux heures. En revanche, le fait de conjuguer les CL à des conférences a eu un effet positif sur l'acquisition et la rétention des connaissances et le fait de les conjuguer au mentorat ou à l'utilisation de feuilles d'évaluation critique a contribué à l'acquisition de compétences en rédaction et à l'adoption par les étudiants d'une attitude positive à l'égard de la MFDP. Conclusions: Les clubs de lecture constituent un moyen efficace et bien accueilli par les apprenants pour enseigner la MFDP au prédoctorat. Ils améliorent les résultats d'apprentissage spécifiques sur le plan de l'acquisition et de la rétention des connaissances, ainsi que les compétences en matière de rédaction et d'évaluation critique. Toutefois, nous n'avons trouvé aucune indication que ces effets puissent se répercuter dans la pratique de la MFDP ou dans les résultats pour les patients.
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Education, Medical, Undergraduate , Education, Medical , Humans , Students , Databases, Bibliographic , Evidence-Based MedicineABSTRACT
Background A recent randomized trial, the MICHELLE trial, demonstrated improved posthospital outcomes with a 35-day course of prophylactic rivaroxaban for patients hospitalized with COVID-19 at high risk of venous thromboembolism. We explored how often these findings may apply to an unselected clinical population of patients hospitalized with COVID-19. Methods and Results Using a 35-hospital retrospective cohort of patients hospitalized between March 7, 2020, and January 23, 2021, with COVID-19 (MI-COVID19 database), we quantified the percentage of hospitalized patients with COVID-19 who would be eligible for rivaroxaban at discharge per MICHELLE trial criteria and report clinical event rates. The main clinical outcome was derived from the MICHELLE trial and included a composite of symptomatic venous thromboembolism, pulmonary embolus-related death, nonhemorrhagic stroke, and cardiovascular death at 35 days. Multiple sensitivity analyses tested different eligibility and exclusion criteria definitions to determine the effect on eligibility for postdischarge anticoagulation prophylaxis. Of 2016 patients hospitalized with COVID-19 who survived to discharge and did not have another indication for anticoagulation, 25.9% (n=523) would be eligible for postdischarge thromboprophylaxis per the MICHELLE trial criteria (range, 2.9%-39.4% on sensitivity analysis). Of the 416 who had discharge anticoagulant data collected, only 13.2% (55/416) were actually prescribed a new anticoagulant at discharge. Of patients eligible for rivaroxaban per the MICHELLE trial, the composite clinical outcome occurred in 1.2% (6/519); similar outcome rates were 5.7% and 0.63% in the MICHELLE trial's control (no anticoagulation) and intervention (rivaroxaban) groups, respectively. Symptomatic venous thromboembolism events and all-cause mortality were 6.2% (32/519) and 5.66% in the MI-COVID19 and MICHELLE trial control cohorts, respectively. Conclusions Across 35 hospitals in Michigan, ≈1 in 4 patients hospitalized with COVID-19 would qualify for posthospital thromboprophylaxis. With only 13% of patients actually receiving postdischarge prophylaxis, there is a potential opportunity for improvement in care.
Subject(s)
COVID-19 , Venous Thromboembolism , Aftercare , Anticoagulants/therapeutic use , COVID-19/complications , Humans , Patient Discharge , Randomized Controlled Trials as Topic , Retrospective Studies , Rivaroxaban/therapeutic use , Venous Thromboembolism/epidemiology , Venous Thromboembolism/etiology , Venous Thromboembolism/prevention & controlABSTRACT
OBJECTIVE: A lack of universal definitions for response and remission in pediatric obsessive-compulsive disorder (OCD) has hampered the comparability of results across trials. To address this problem, we conducted an individual participant data diagnostic test accuracy meta-analysis to evaluate the discriminative ability of the Children's Yale-Brown Obsessive-Compulsive Scale (CY-BOCS) in determining response and remission. We also aimed to generate empirically derived cutoffs on the CY-BOCS for these outcomes. METHOD: A systematic review of PubMed, PsycINFO, Embase and CENTRAL identified 5,401 references; 42 randomized controlled clinical trials were considered eligible, and 21 provided data for inclusion (N = 1,234). Scores of ≤2 in the Clinical Global Impressions Improvement and Severity scales were chosen to define response and remission, respectively. A 2-stage, random-effects meta-analysis model was established. The area under the curve (AUC) and the Youden Index were computed to indicate the discriminative ability of the CY-BOCS and to guide for the optimal cutoff, respectively. RESULTS: The CY-BOCS had sufficient discriminative ability to determine response (AUC = 0.89) and remission (AUC = 0.92). The optimal cutoff for response was a ≥35% reduction from baseline to posttreatment (sensitivity = 83.9, 95% CI = 83.7-84.1; specificity = 81.7, 95% CI = 81.5-81.9). The optimal cutoff for remission was a posttreatment raw score of ≤12 (sensitivity = 82.0, 95% CI = 81.8-82.2; specificity = 84.6, 95% CI = 84.4-84.8). CONCLUSION: Meta-analysis identified empirically optimal cutoffs on the CY-BOCS to determine response and remission in pediatric OCD randomized controlled clinical trials. Systematic adoption of standardized operational definitions for response and remission will improve comparability across trials for pediatric OCD.
Subject(s)
Obsessive-Compulsive Disorder , Child , Humans , Obsessive-Compulsive Disorder/diagnosis , Obsessive-Compulsive Disorder/drug therapy , Research DesignABSTRACT
BACKGROUND: Ergot, caused by the fungal pathogen Claviceps purpurea, infects the female flowers of a range of cereal crops, including wheat. To understand the interaction between C. purpurea and hexaploid wheat we undertook an extensive examination of the reprogramming of the wheat transcriptome in response to C. purpurea infection through floral tissues (i.e. the stigma, transmitting and base ovule tissues of the ovary) and over time. RESULTS: C. purpurea hyphae were observed to have grown into and down the stigma at 24 h (H) after inoculation. By 48H hyphae had grown through the transmitting tissue into the base, while by 72H hyphae had surrounded the ovule. By 5 days (D) the ovule had been replaced by fungal tissue. Differential gene expression was first observed at 1H in the stigma tissue. Many of the wheat genes differentially transcribed in response to C. purpurea infection were associated with plant hormones and included the ethylene (ET), auxin, cytokinin, gibberellic acid (GA), salicylic acid and jasmonic acid (JA) biosynthetic and signaling pathways. Hormone-associated genes were first detected in the stigma and base tissues at 24H, but not in the transmitting tissue. Genes associated with GA and JA pathways were seen in the stigma at 24H, while JA and ET-associated genes were identified in the base at 24H. In addition, several defence-related genes were differential expressed in response to C. purpurea infection, including antifungal proteins, endocytosis/exocytosis-related proteins, NBS-LRR class proteins, genes involved in programmed cell death, receptor protein kinases and transcription factors. Of particular interest was the identification of differential expression of wheat genes in the base tissue well before the appearance of fungal hyphae, suggesting that a mobile signal, either pathogen or plant-derived, is delivered to the base prior to colonisation. CONCLUSIONS: Multiple host hormone biosynthesis and signalling pathways were significantly perturbed from an early stage in the wheat - C. purpurea interaction. Differential gene expression at the base of the ovary, ahead of arrival of the pathogen, indicated the potential presence of a long-distance signal modifying host gene expression.
Subject(s)
Claviceps/physiology , Plant Diseases/genetics , Plant Diseases/microbiology , Transcriptome/genetics , Triticum/genetics , Triticum/microbiology , Gene Expression Profiling , Gene Expression Regulation, Plant/drug effects , Genes, Plant , Plant Growth Regulators/pharmacology , RNA-Seq , Time Factors , Triticum/drug effectsABSTRACT
Importance: Venous thromboembolism (VTE) is a common complication of COVID-19. It is not well understood how hospitals have managed VTE prevention and the effect of prevention strategies on mortality. Objective: To characterize frequency, variation across hospitals, and change over time in VTE prophylaxis and treatment-dose anticoagulation in patients hospitalized for COVID-19, as well as the association of anticoagulation strategies with in-hospital and 60-day mortality. Design, Setting, and Participants: This cohort study of adults hospitalized with COVID-19 used a pseudorandom sample from 30 US hospitals in the state of Michigan participating in a collaborative quality initiative. Data analyzed were from patients hospitalized between March 7, 2020, and June 17, 2020. Data were analyzed through March 2021. Exposures: Nonadherence to VTE prophylaxis (defined as missing ≥2 days of VTE prophylaxis) and receipt of treatment-dose or prophylactic-dose anticoagulants vs no anticoagulation during hospitalization. Main Outcomes and Measures: The effect of nonadherence and anticoagulation strategies on in-hospital and 60-day mortality was assessed using multinomial logit models with inverse probability of treatment weighting. Results: Of a total 1351 patients with COVID-19 included (median [IQR] age, 64 [52-75] years; 47.7% women, 48.9% Black patients), only 18 (1.3%) had a confirmed VTE, and 219 (16.2%) received treatment-dose anticoagulation. Use of treatment-dose anticoagulation without imaging ranged from 0% to 29% across hospitals and increased over time (adjusted odds ratio [aOR], 1.46; 95% CI, 1.31-1.61 per week). Of 1127 patients who ever received anticoagulation, 392 (34.8%) missed 2 or more days of prophylaxis. Missed prophylaxis varied from 11% to 61% across hospitals and decreased markedly over time (aOR, 0.89; 95% CI, 0.82-0.97 per week). VTE nonadherence was associated with higher 60-day (adjusted hazard ratio [aHR], 1.31; 95% CI, 1.03-1.67) but not in-hospital mortality (aHR, 0.97; 95% CI, 0.91-1.03). Receiving any dose of anticoagulation (vs no anticoagulation) was associated with lower in-hospital mortality (only prophylactic dose: aHR, 0.36; 95% CI, 0.26-0.52; any treatment dose: aHR, 0.38; 95% CI, 0.25-0.58). However, only the prophylactic dose of anticoagulation remained associated with lower mortality at 60 days (prophylactic dose: aHR, 0.71; 95% CI, 0.51-0.90; treatment dose: aHR, 0.92; 95% CI, 0.63-1.35). Conclusions and Relevance: This large, multicenter cohort of patients hospitalized with COVID-19, found evidence of rapid dissemination and implementation of anticoagulation strategies, including use of treatment-dose anticoagulation. As only prophylactic-dose anticoagulation was associated with lower 60-day mortality, prophylactic dosing strategies may be optimal for patients hospitalized with COVID-19.
Subject(s)
Anticoagulants/therapeutic use , COVID-19/complications , Hospitalization/trends , SARS-CoV-2 , Venous Thromboembolism/prevention & control , Aged , COVID-19/epidemiology , Female , Hospital Mortality/trends , Humans , Incidence , Male , Middle Aged , Retrospective Studies , Survival Rate/trends , United States/epidemiology , Venous Thromboembolism/epidemiology , Venous Thromboembolism/etiologyABSTRACT
The ongoing pandemic of SARS-CoV-2 calls for rapid and cost-effective methods to accurately identify infected individuals. The vast majority of patient samples is assessed for viral RNA presence by RT-qPCR. Our biomedical research institute, in collaboration between partner hospitals and an accredited clinical diagnostic laboratory, established a diagnostic testing pipeline that has reported on more than 252,000 RT-qPCR results since its commencement at the beginning of April 2020. However, due to ongoing demand and competition for critical resources, alternative testing strategies were sought. In this work, we present a clinically-validated procedure for high-throughput SARS-CoV-2 detection by RT-LAMP in 25 minutes that is robust, reliable, repeatable, sensitive, specific, and inexpensive.
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BACKGROUND: Emergence of variants with specific mutations in key epitopes in the spike protein of SARS-CoV-2 raises concerns pertinent to mass vaccination campaigns and use of monoclonal antibodies. We aimed to describe the emergence of the B.1.1.7 variant of concern (VOC), including virological characteristics and clinical severity in contemporaneous patients with and without the variant. METHODS: In this cohort study, samples positive for SARS-CoV-2 on PCR that were collected from Nov 9, 2020, for patients acutely admitted to one of two hospitals on or before Dec 20, 2020, in London, UK, were sequenced and analysed for the presence of VOC-defining mutations. We fitted Poisson regression models to investigate the association between B.1.1.7 infection and severe disease (defined as point 6 or higher on the WHO ordinal scale within 14 days of symptoms or positive test) and death within 28 days of a positive test and did supplementary genomic analyses in a cohort of chronically shedding patients and in a cohort of remdesivir-treated patients. Viral load was compared by proxy, using PCR cycle threshold values and sequencing read depths. FINDINGS: Of 496 patients with samples positive for SARS-CoV-2 on PCR and who met inclusion criteria, 341 had samples that could be sequenced. 198 (58%) of 341 had B.1.1.7 infection and 143 (42%) had non-B.1.1.7 infection. We found no evidence of an association between severe disease and death and lineage (B.1.1.7 vs non-B.1.1.7) in unadjusted analyses (prevalence ratio [PR] 0·97 [95% CI 0·72-1·31]), or in analyses adjusted for hospital, sex, age, comorbidities, and ethnicity (adjusted PR 1·02 [0·76-1·38]). We detected no B.1.1.7 VOC-defining mutations in 123 chronically shedding immunocompromised patients or in 32 remdesivir-treated patients. Viral load by proxy was higher in B.1.1.7 samples than in non-B.1.1.7 samples, as measured by cycle threshold value (mean 28·8 [SD 4·7] vs 32·0 [4·8]; p=0·0085) and genomic read depth (1280 [1004] vs 831 [682]; p=0·0011). INTERPRETATION: Emerging evidence exists of increased transmissibility of B.1.1.7, and we found increased virus load by proxy for B.1.1.7 in our data. We did not identify an association of the variant with severe disease in this hospitalised cohort. FUNDING: University College London Hospitals NHS Trust, University College London/University College London Hospitals NIHR Biomedical Research Centre, Engineering and Physical Sciences Research Council.
Subject(s)
COVID-19/virology , Genome, Viral , SARS-CoV-2/genetics , Severity of Illness Index , Whole Genome Sequencing , Aged , Aged, 80 and over , Cohort Studies , Female , Humans , London , Male , Middle Aged , Phylogeny , United Kingdom , Viral Load , Virus SheddingABSTRACT
The widespread use of complementary products poses a challenge to clinicians in the perioperative period and may increase perioperative risk. Because dietary supplements are regulated differently from traditional pharmaceuticals and guidance is often lacking, the Society for Perioperative Assessment and Quality Improvement convened a group of experts to review available literature and create a set of consensus recommendations for the perioperative management of these supplements. Using a modified Delphi method, the authors developed recommendations for perioperative management of 83 dietary supplements. We have made our recommendations to discontinue or continue a dietary supplement based on the principle that without a demonstrated benefit, or with a demonstrated lack of harm, there is little downside in temporarily discontinuing an herbal supplement before surgery. Discussion with patients in the preoperative visit is a crucial time to educate patients as well as gather vital information. Patients should be specifically asked about use of dietary supplements and cannabinoids, as many will not volunteer this information. The preoperative clinic visit provides the best opportunity to educate patients about the perioperative management of various supplements as this visit is typically scheduled at least 2 weeks before the planned procedure.
Subject(s)
Dietary Supplements , Intraoperative Complications/prevention & control , Postoperative Complications/prevention & control , Preoperative Care/standards , Delphi Technique , Dietary Supplements/adverse effects , Humans , Intraoperative Complications/etiology , Postoperative Complications/etiology , Preoperative Care/methods , Quality ImprovementABSTRACT
All coronaviruses known to have recently emerged as human pathogens probably originated in bats1. Here we use a single experimental platform based on immunodeficient mice implanted with human lung tissue (hereafter, human lung-only mice (LoM)) to demonstrate the efficient in vivo replication of severe acute respiratory syndrome coronavirus (SARS-CoV), Middle East respiratory syndrome coronavirus (MERS-CoV) and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), as well as two endogenous SARS-like bat coronaviruses that show potential for emergence as human pathogens. Virus replication in this model occurs in bona fide human lung tissue and does not require any type of adaptation of the virus or the host. Our results indicate that bats contain endogenous coronaviruses that are capable of direct transmission to humans. Our detailed analysis of in vivo infection with SARS-CoV-2 in human lung tissue from LoM showed a predominant infection of human lung epithelial cells, including type-2 pneumocytes that are present in alveoli and ciliated airway cells. Acute infection with SARS-CoV-2 was highly cytopathic and induced a robust and sustained type-I interferon and inflammatory cytokine and chemokine response. Finally, we evaluated a therapeutic and pre-exposure prophylaxis strategy for SARS-CoV-2 infection. Our results show that therapeutic and prophylactic administration of EIDD-2801-an oral broad-spectrum antiviral agent that is currently in phase II/III clinical trials-markedly inhibited SARS-CoV-2 replication in vivo, and thus has considerable potential for the prevention and treatment of COVID-19.
Subject(s)
COVID-19 Drug Treatment , COVID-19/prevention & control , Cytidine/analogs & derivatives , Hydroxylamines/administration & dosage , Hydroxylamines/therapeutic use , Administration, Oral , Alveolar Epithelial Cells/immunology , Alveolar Epithelial Cells/pathology , Alveolar Epithelial Cells/virology , Animals , COVID-19/immunology , Chemoprevention , Chiroptera/virology , Clinical Trials, Phase II as Topic , Clinical Trials, Phase III as Topic , Cytidine/administration & dosage , Cytidine/therapeutic use , Cytokines/immunology , Epithelial Cells/virology , Female , Heterografts , Humans , Immunity, Innate , Interferon Type I/immunology , Lung/immunology , Lung/pathology , Lung/virology , Lung Transplantation , Male , Mice , Post-Exposure Prophylaxis , Pre-Exposure Prophylaxis , SARS-CoV-2/immunology , SARS-CoV-2/pathogenicity , Virus ReplicationABSTRACT
During development, cells gain positional information through the interpretation of dynamic morphogen gradients. A proposed mechanism for interpreting opposing morphogen gradients is mutual inhibition of downstream transcription factors, but isolating the role of this specific motif within a natural network remains a challenge. Here, we engineer a synthetic morphogen-induced mutual inhibition circuit in E. coli populations and show that mutual inhibition alone is sufficient to produce stable domains of gene expression in response to dynamic morphogen gradients, provided the spatial average of the morphogens falls within the region of bistability at the single cell level. When we add sender devices, the resulting patterning circuit produces theoretically predicted self-organised gene expression domains in response to a single gradient. We develop computational models of our synthetic circuits parameterised to timecourse fluorescence data, providing both a theoretical and experimental framework for engineering morphogen-induced spatial patterning in cell populations.
Subject(s)
Escherichia coli/cytology , Escherichia coli/growth & development , Escherichia coli/genetics , Computer Simulation , Gene Expression Regulation, Bacterial , Gene Regulatory Networks , Models, Biological , Synthetic Biology , Transcription FactorsABSTRACT
Reaction-diffusion processes across layered media arise in several scientific domains such as pattern-forming E. coli on agar substrates, epidermal-mesenchymal coupling in development, and symmetry-breaking in cell polarization. We develop a modeling framework for bilayer reaction-diffusion systems and relate it to a range of existing models. We derive conditions for diffusion-driven instability of a spatially homogeneous equilibrium analogous to the classical conditions for a Turing instability in the simplest nontrivial setting where one domain has a standard reaction-diffusion system, and the other permits only diffusion. Due to the transverse coupling between these two regions, standard techniques for computing eigenfunctions of the Laplacian cannot be applied, and so we propose an alternative method to compute the dispersion relation directly. We compare instability conditions with full numerical simulations to demonstrate impacts of the geometry and coupling parameters on patterning, and explore various experimentally relevant asymptotic regimes. In the regime where the first domain is suitably thin, we recover a simple modulation of the standard Turing conditions, and find that often the broad impact of the diffusion-only domain is to reduce the ability of the system to form patterns. We also demonstrate complex impacts of this coupling on pattern formation. For instance, we exhibit non-monotonicity of pattern-forming instabilities with respect to geometric and coupling parameters, and highlight an instability from a nontrivial interaction between kinetics in one domain and diffusion in the other. These results are valuable for informing design choices in applications such as synthetic engineering of Turing patterns, but also for understanding the role of stratified media in modulating pattern-forming processes in developmental biology and beyond.
Subject(s)
Models, Biological , Animals , Developmental Biology , Diffusion , Escherichia coli , Humans , Kinetics , Mathematical ConceptsABSTRACT
All known recently emerged human coronaviruses likely originated in bats. Here, we used a single experimental platform based on human lung-only mice (LoM) to demonstrate efficient in vivo replication of all recently emerged human coronaviruses (SARS-CoV, MERS-CoV, SARS-CoV-2) and two highly relevant endogenous pre-pandemic SARS-like bat coronaviruses. Virus replication in this model occurs in bona fide human lung tissue and does not require any type of adaptation of the virus or the host. Our results indicate that bats harbor endogenous coronaviruses capable of direct transmission into humans. Further detailed analysis of pandemic SARS-CoV-2 in vivo infection of LoM human lung tissue showed predominant infection of human lung epithelial cells, including type II pneumocytes present in alveoli and ciliated airway cells. Acute SARS-CoV-2 infection was highly cytopathic and induced a robust and sustained Type I interferon and inflammatory cytokine/chemokine response. Finally, we evaluated a pre-exposure prophylaxis strategy for coronavirus infection. Our results show that prophylactic administration of EIDD-2801, an oral broad spectrum antiviral currently in phase II clinical trials for the treatment of COVID-19, dramatically prevented SARS-CoV-2 infection in vivo and thus has significant potential for the prevention and treatment of COVID-19.
ABSTRACT
Movement, behavioral, and neuropsychiatric disorders in children have been linked to infections and a group of anti-neuronal autoantibodies, implying dopamine receptor-mediated encephalitis within the basal ganglia. The purpose of this study was to determine if anti-neuronal biomarkers, when used as a group, confirmed the acute disease in Sydenham chorea (SC) and pediatric autoimmune neuropsychiatric disorder associated with streptococcal infections (PANDAS). IgG autoantibodies against four neuronal autoantigens (tubulin, lysoganglioside GM1, and dopamine receptors D1 and D2) were detected in SC sera (N=8), sera and/or cerebrospinal fluid (CSF) from two groups of PANDAS cases (N=25 first group and N=35 second group), sera from Tourette's syndrome (N=18), obsessive-compulsive disorder (N=25), attention deficit hyperactivity disorder (N=18), and healthy controls (N=28) by direct enzyme-linked immunosorbent assay (ELISA). IgG specific for neuronal autoantigens was significantly elevated during the acute symptomatic phase, and the activity of calcium/calmodulin-dependent protein kinase II (CaMKII) pathway was significantly elevated in human neuronal cells. Five assays confirmed the disease in SC and in two groups of children with PANDAS. In 35 acute onset PANDAS patients, 32 sera (91.4%) were positive for one or more of the anti-neuronal autoantibodies compared with 9 of 28 healthy controls (32.1%, p<0.0001). Importantly, CSF of 32 (91.4%) PANDAS patients had one or more detectable anti-neuronal autoantibody titers and CaMKII activation. Among healthy control subjects with elevated serum autoantibody titers for individual antigens, none (0%) were positively associated with elevated positive CaMKII activation, which was a striking contrast to the sera of PANDAS subjects, who had 76-89% positive association with elevated individual autoantibody titers and positive CaMKII activity. At 6 months follow-up, symptoms improved for more than 80% of PANDAS subjects, and serum autoantibody titers also significantly decreased. Results reported herein and previously published studies in our laboratory suggest the antibody biomarkers may be a useful adjunct to clinical diagnosis of SC, PANDAS, and related disorders and are the first known group of autoantibodies detecting dopamine receptor-mediated encephalitis in children.
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An amendment to this paper has been published and can be accessed via a link at the top of the paper.
ABSTRACT
Hospitalized patients with acute medical illnesses are at risk for venous thromboembolism (VTE) during and after a hospital stay. Risk factors include physical immobilization and underlying pathophysiologic processes that activate the coagulation pathway and are still present after discharge. Strategies for optimal pharmacologic VTE thromboprophylaxis are evolving, and recommendations for VTE prophylaxis can be further refined to protect high-risk patients after hospital discharge. An early study of extended VTE prophylaxis with a parenteral agent in medically ill patients yielded inconclusive results with regard to efficacy and bleeding. In the Acute Medically Ill VTE Prevention with Extended Duration Betrixaban (APEX) trial, extended use of betrixaban halved symptomatic VTE, decreased hospital readmission, and reduced stroke and major adverse cardiovascular events compared with standard enoxaparin prophylaxis. Based on findings from APEX, the Food and Drug Administration approved betrixaban in 2017 for extended VTE prophylaxis in acute medically ill patients. In the Reducing Post-Discharge Venous Thrombo-Embolism Risk (MARINER) study, extended use of rivaroxaban halved symptomatic VTE in high-risk medical patients compared with placebo. In 2019, rivaroxaban was approved for extended thromboprophylaxis in high-risk medical patients, thus making available a new strategy for in-hospital and post-discharge VTE prevention. To address the critical unmet need for VTE prophylaxis in medically ill patients at the time of hospital discharge, the North American Thrombosis Forum (NATF) is launching the Anticoagulation Action Initiative, a comprehensive consensus document that provides practical guidance and straightforward, patient-centered recommendations for VTE prevention during hospitalization and after discharge.