Clues on the dynamics of DNA replication in Giardia lamblia.

Genomic replication is a critical, regulated process that ensures accurate genetic information duplication. In eukaryotic cells, strategies have evolved to prevent conflicts between replication and transcription. Giardia lamblia, a binucleated protozoan, alternates between tetraploid and octaploid genomes during its cell cycle. Using single-molecule techniques like DNA combing and nanopore-based sequencing, we investigated the spatio-temporal organization of DNA replication, replication fork progression and potential head-on replication-transcription collisions in Giardia trophozoites. Our findings indicate that Giardia chromosomes are replicated from only a few active origins, which are widely spaced and exhibit faster replication rates compared to those in other protozoan parasites. Immunofluorescence assays revealed that ∼20% of trophozoites show asynchronous replication between nuclei. Forksense and gene ontology analyses disclosed that genes in regions with potential head-on collisions are linked to chromatin dynamics, cell cycle regulation and DNA replication/repair pathways, possibly explaining the observed asynchronous replication in part of the population. This study offers the first comprehensive view of replication dynamics in Giardia, which is the pathogen that causes giardiasis, a diarrheal disease impacting millions worldwide.

Tracking the recruitment and evolution of snake toxins using the evolutionary context provided by the Bothrops jararaca genome.

Venom is a key adaptive innovation in snakes, and how nonvenom genes were co-opted to become part of the toxin arsenal is a significant evolutionary question. While this process has been investigated through the phylogenetic reconstruction of toxin sequences, evidence provided by the genomic context of toxin genes remains less explored. To investigate the process of toxin recruitment, we sequenced the genome of Bothrops jararaca, a clinically relevant pitviper. In addition to producing a road map with canonical structures of genes encoding 12 toxin families, we inferred most of the ancestral genes for their loci. We found evidence that 1) snake venom metalloproteinases (SVMPs) and phospholipases A2 (PLA2) have expanded in genomic proximity to their nonvenomous ancestors; 2) serine proteinases arose by co-opting a local gene that also gave rise to lizard gilatoxins and then expanded; 3) the bradykinin-potentiating peptides originated from a C-type natriuretic peptide gene backbone; and 4) VEGF-F was co-opted from a PGF-like gene and not from VEGF-A. We evaluated two scenarios for the original recruitment of nontoxin genes for snake venom: 1) in locus ancestral gene duplication and 2) in locus ancestral gene direct co-option. The first explains the origins of two important toxins (SVMP and PLA2), while the second explains the emergence of a greater number of venom components. Overall, our results support the idea of a locally assembled venom arsenal in which the most clinically relevant toxin families expanded through posterior gene duplications, regardless of whether they originated by duplication or gene co-option.

Phylogenetically diverse diets favor more complex venoms in North American pitvipers.

The role of natural selection in the evolution of trait complexity can be characterized by testing hypothesized links between complex forms and their functions across species. Predatory venoms are composed of multiple proteins that collectively function to incapacitate prey. Venom complexity fluctuates over evolutionary timescales, with apparent increases and decreases in complexity, and yet the causes of this variation are unclear. We tested alternative hypotheses linking venom complexity and ecological sources of selection from diet in the largest clade of front-fanged venomous snakes in North America: the rattlesnakes, copperheads, cantils, and cottonmouths. We generated independent transcriptomic and proteomic measures of venom complexity and collated several natural history studies to quantify dietary variation. We then constructed genome-scale phylogenies for these snakes for comparative analyses. Strikingly, prey phylogenetic diversity was more strongly correlated to venom complexity than was overall prey species diversity, specifically implicating prey species' divergence, rather than the number of lineages alone, in the evolution of complexity. Prey phylogenetic diversity further predicted transcriptomic complexity of three of the four largest gene families in viper venom, showing that complexity evolution is a concerted response among many independent gene families. We suggest that the phylogenetic diversity of prey measures functionally relevant divergence in the targets of venom, a claim supported by sequence diversity in the coagulation cascade targets of venom. Our results support the general concept that the diversity of species in an ecological community is more important than their overall number in determining evolutionary patterns in predator trait complexity.

A traveling SARS-CoV-2 laboratory as part of a pandemic response among vulnerable Brazilian populations.

BACKGROUND: Brazil has been dramatically hit by the SARS-CoV-2 pandemic and is a world leader in COVID-19 morbidity and mortality. Additionally, the largest country of Latin America has been a continuous source of SARS-CoV-2 variants and shows extraordinary variability of the pandemic strains probably related to the country´s outstanding position as a Latin American economical and transportation hub. Not all regions of the country show sufficient infrastructure for SARS-CoV-2 diagnosis and genotyping which can negatively impact the pandemic response. METHODS: Due to this reason and to disburden the diagnostic system of the inner São Paulo State, the Butantan Institute established the Mobile Laboratory (in Portuguese: LabMovel) for SARS-CoV-2 testing which started a trip of the most important "hotspots" of the most populous Brazilian region. The LabMovel initiated in two important cities of the State: Aparecida do Norte (an important religious center) and the Baixada Santista region which incorporates the port of Santos, the busiest in Latin America. The LabMovel was fully equipped with an automatized system for SARS-CoV-2 diagnosis and sequencing/genotyping. It also integrated the laboratory systems for patient records and results divulgation including in the Federal Brazilian Healthcare System. RESULTS: Currently,16,678 samples were tested, among them 1,217 from Aparecida and 4,564 from Baixada Santista. We tracked the delta introductio in the tested regions with its high diversification. The established mobile SARS-CoV-2 laboratory had a major impact on the Public Health System of the included cities including timely delivery of the results to the healthcare agents and the Federal Healthcare system, evaluation of the vaccination status of the positive individuals in the background of exponential vaccination process in Brazil and scientific and technological divulgation of the fieldwork to the most vulnerable populations. CONCLUSIONS: The SARS-CoV-2 pandemic has demonstrated worldwide the importance of science to fight against this viral agent and the LabMovel shows that it is possible to integrate researchers, clinicians, healthcare workers and patients to take rapid actions that can in fact mitigate this and other epidemiological situations.

Stability of Morphine Sulfate-Clonidine and Sufentanil-Clonidine Mixtures.

BACKGROUND: Spinal analgesia is recommended for intractable cancer pain. Morphine-clonidine and sufentanil-clonidine are often used in association in intrathecal drug delivery systems, injected by intraabdominal pumps. To refill these pumps and to limit patient transport, it may be necessary to ship the mixtures in polypropylene syringes to peripheral establishments located near patient homes. The purpose of this study is to determine the stability of morphine-clonidine and sufentanil-clonidine mixtures in polypropylene syringes to ensure the best and safest transport conditions and in implantable pumps for intrathecal use. MATERIALS AND METHODS: The stability study method was conceived according to the International Council for Harmonization guidelines. For polypropylene syringes, four different mixtures of morphine-clonidine and sufentanil-clonidine were assessed over seven days. Two storage temperatures were tested (5 ± 3 °C and 25 ± 2 °C). For implantable pumps, two different mixtures of morphine-clonidine and sufentanil-clonidine were assessed over 28 days and stored at 37 °C. RESULTS: For the morphine-clonidine mixtures in polypropylene syringes, all mixtures remained stable for five days in both storage conditions (5 ± 3 °C and 25 ± 2 °C) because of relative concentrations systematically positioned between 90% and 110% (95% CIs of the mean of three samples). The two mixtures in implantable pumps remained stable for 28 days. For the sufentanil-clonidine mixtures in polypropylene syringes, cold conservation kept all the preparations stable for seven days, whereas a quick degradation was observed after only two days for ambient storage conditions. This result is similar to that with an implantable pump, in which the concentration is <90% on day 7 for low concentration mixtures. No visual modification, no significant pH modification, and no changes in turbidity assays were observed in either study. CONCLUSION: This study shows the stability of the morphine-clonidine mixtures in syringes stored at 5 °C for five days and in implantable pumps stored at 37 °C for 28 days. For the sufentanil-clonidine mixtures, the results show stability in syringes for seven days at 5 °C. Pump results show stability of seven days for low concentrations and 28 days for high concentrations.

SARS-COV-2 genomic monitoring in the state of São Paulo unveils two emerging AY.43 sublineages.

Delta VOC is highly diverse with more than 120 sublineages already described as of November 30, 2021. In this study, through active monitoring of circulating severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) variants in the state of São Paulo, southeast Brazil, we identified two emerging sublineages from the ancestral AY.43 strain which were classified as AY.43.1 and AY.43.2. These sublineages were defined by the following characteristic nonsynonymous mutations ORF1ab:A4133V and ORF3a:T14I for the AY.43.1 and ORF1ab:G1155C for the AY.43.2 and our analysis reveals that they might have a likely-Brazilian origin. Much is still unknown regarding their dissemination in the state of São Paulo and Brazil as well as their potential impact on the ongoing vaccination process. However, the results obtained in this study reinforce the importance of genomic surveillance activity for timely identification of emerging SARS-CoV-2 variants which can impact the ongoing SARS-CoV-2 vaccination and public health policies.

The association of pre-transplant atrial fibrillation with in-hospital outcomes in patients undergoing orthotopic liver transplantation: A propensity score matching analysis.

INTRODUCTION: In this study, we sought to evaluate the prevalence and association of pre-transplant atrial fibrillation (AF) on 30-day postoperative outcomes in patients undergoing orthotopic liver transplant (OLT). METHOD: The National Inpatient Sample Database was queried from 2011 to 2017 for relevant ICD-9 and ICD-10 procedural and diagnostic codes. Baseline characteristics and in-hospital outcomes were compared in patients who underwent OLT with AF and those without. RESULTS: Among 45,357 patients who underwent OLT, women made up 35.8% of the overall population. The prevalence of AF before transplant was 2932 (6.5%) with a trend toward increasing prevalence, with an average annual change rate of 4.19%. Applying propensity score matching to control for potential confounding factors, there was no association between pre-transplant AF and in-hospital mortality in patients undergoing OLT, however there was a higher incidence of perioperative complications including: acute kidney injury, ventricular tachycardia, major bleeding, blood product transfusion, and septic shock. CONCLUSION: In patients undergoing OLT, pre-transplant AF is increasing in prevalence and appears to be associated with similar in-hospital mortality but worse perioperative outcomes. Greater emphasis should be placed on AF in the preoperative cardiovascular risk stratification of patients undergoing OLT.

Replacement and Parallel Simplification of Nonhomologous Proteinases Maintain Venom Phenotypes in Rear-Fanged Snakes.

Novel phenotypes are commonly associated with gene duplications and neofunctionalization, less documented are the cases of phenotypic maintenance through the recruitment of novel genes. Proteolysis is the primary toxic character of many snake venoms, and ADAM metalloproteinases, named snake venom metalloproteinases (SVMPs), are largely recognized as the major effectors of this phenotype. However, by investigating original transcriptomes from 58 species of advanced snakes (Caenophidia) across their phylogeny, we discovered that a different enzyme, matrix metalloproteinase (MMP), is actually the dominant venom component in three tribes (Tachymenini, Xenodontini, and Conophiini) of rear-fanged snakes (Dipsadidae). Proteomic and functional analyses of these venoms further indicate that MMPs are likely playing an "SVMP-like" function in the proteolytic phenotype. A detailed look into the venom-specific sequences revealed a new highly expressed MMP subtype, named snake venom MMP (svMMP), which originated independently on at least three occasions from an endogenous MMP-9. We further show that by losing ancillary noncatalytic domains present in its ancestors, svMMPs followed an evolutionary path toward a simplified structure during their expansion in the genomes, thus paralleling what has been proposed for the evolution of their Viperidae counterparts, the SVMPs. Moreover, we inferred an inverse relationship between the expression of svMMPs and SVMPs along the evolutionary history of Xenodontinae, pointing out that one type of enzyme may be substituting for the other, whereas the general (metallo)proteolytic phenotype is maintained. These results provide rare evidence on how relevant phenotypic traits can be optimized via natural selection on nonhomologous genes, yielding alternate biochemical components.

Evaluating the impact of chronic obstructive pulmonary disease on in-hospital outcomes following left ventricular assist device implantation.

BACKGROUND: Chronic obstructive pulmonary disease (COPD) is a cause of ventricular dysfunction. However, in the setting of patients with heart failure undergoing left ventricular assist device (LVAD) implantation, there is a paucity of data on the association between COPD and in-hospital outcomes. METHODS AND RESULTS: Retrospective cohort study based on the NIS including patients ≥18 years who underwent LVAD implantation from 2011 to 2017. Multivariate regression was used to evaluate the impact of COPD on in-hospital outcomes. A total of 25,503 patients underwent LVAD implantation, of which 13.8% also had COPD. COPD group was older (median 62 vs. 58 years), and more males (82% vs. 76.4%, p < .001 for both). COPD group had more hypertension, diabetes, atrial tachyarrhythmias, dyslipidemia, prior stroke, coronary artery diseases, pulmonary hypertension, and chronic kidney disease (p < .001 for all). No differences in strokes, infections, mechanical circulatory support, and LVAD thrombosis. There was a higher incident of inpatient acute kidney injury, major bleeding, cardiac complications, thromboembolism, and cardiac arrest in patients without COPD (p < .05 for all). Compared with no-COPD group, COPD group had a lower mortality (6.2% vs. 12.4%; odds ratio, 0.59; confidence interval, 0.512-0.685; p < .05). CONCLUSION: Patients with COPD undergoing LVAD implantation have more comorbidities, without an associated increase mortality.

In-hospital outcomes in unhoused patients with cardiogenic shock in the United States: Insights from The National Inpatient Sample 2011-2019.

BACKGROUND: Unhoused patients face significant barriers to receiving health care in both the inpatient and outpatient settings. For unhoused patients with heart failure who are in extremis, there is a lack of data regarding in-hospital outcomes and resource utilization in the setting of cardiogenic shock (CS). HYPOTHESIS: Unhoused patients hospitalized with CS have increased mortality and decreased use of invasive therapies as compared to housed patients. METHODS: The National Inpatient Sample (NIS) database was queried from 2011 to 2019 for relevant ICD-9 and ICD-10 codes to identify unhoused patients with an admission diagnosis of CS. Baseline characteristics and in-hospital outcomes between patients were compared. Binary logistic regression was used to adjust outcomes for prespecified and significantly different baseline characteristics (p < .05). RESULTS: We identified a weighted sample of 1 202 583 adult CS hospitalizations, of whom 4510 were unhoused (0.38%). There was no significant difference in the comorbidity adjusted odds of mortality between groups. Unhoused patients had lower odds of receiving mechanical circulatory support, left heart catheterization, percutaneous coronary intervention, or pulmonary artery catheterization. Unhoused patients had higher adjusted odds of infectious complications, undergoing intubation, or requiring restraints. CONCLUSIONS: These data suggest that, despite having fewer traditional comorbidities, unhoused patients have similar mortality and less access to more aggressive care than housed patients. Unhoused patients may experience under-diuresis, or more conservative care strategies, as evidenced by the higher intubation rate in this population. Further studies are needed to elucidate long-term outcomes and investigate systemic methods to ameliorate barriers to care in unhoused populations.

In-Hospital Outcomes in Patients With Non-ST Segment Elevation Myocardial Infarction and Concomitant Neurodevelopmental Disorders in the United States: Insights From the National Inpatient Sample 2011-2020.

Patients with neurodevelopmental disorders (NDDs) encounter significant barriers to receiving quality health care, particularly for acute conditions such as non-ST segment elevation myocardial infarction (NSTEMI). This study addresses the critical gap in knowledge regarding in-hospital outcomes and the use of invasive therapies in this demographic. By analyzing data from the National Inpatient Sample database from 2011 to 2020 using the International Classification of Diseases, Ninth Edition (ICD-9) and Tenth Edition (ICD-10) codes, we identified patients with NSTEMI, both with and without NDDs, and compared baseline characteristics, in-hospital outcomes, and the application of invasive treatments. The analysis involved a weighted sample of 7,482,216 NSTEMI hospitalizations, of which 30,168 (0.40%) patients had NDDs. There were significantly higher comorbidity-adjusted odds of in-hospital mortality, cardiac arrest, endotracheal intubation, infectious complications, ventricular arrhythmias, and restraint use among the NDD cohort. Conversely, this group exhibited lower adjusted odds of undergoing left heart catheterization, percutaneous coronary intervention, or coronary artery bypass graft surgery. These findings underscore the disparities faced by patients with NDDs in accessing invasive cardiac interventions, highlighting the need for further research to address these barriers and improve care quality for this vulnerable population.

In-hospital outcomes of septal myectomy vs. alcohol septal ablation for hypertrophic cardiomyopathy with outflow tract obstruction: An update and insights from the national inpatient sample from 2011 to 2019.

Septal Myectomy (SM) and Alcohol Septal Ablation (ASA) improve symptoms in patients with Hypertrophic Cardiomyopathy with outflow tract obstruction (oHCM). However, outcomes data in this population is predominantly from specialized centers. The National Inpatient Database was queried from 2011 to 2019 for relevant international classification of diseases (ICD)-9 and -10 diagnostic and procedural codes. We compared baseline characteristics and in-hospital outcomes of patients with oHCM who underwent SM vs ASA. A p-value < 0.001 was considered statistically significant. We identified 15,119 patients with oHCM who underwent septal reduction therapies, of whom 57.4% underwent SM, and 42.6% underwent ASA. Patients who underwent SM had higher all-cause mortality (OR: 1.8 (1.3-2.5)), post-procedure ischemic stroke (OR: 2.3 (1.7-3.2)), acute kidney injury (OR: 1.4 (1.2-1.7)), vascular complications (OR: 3.6 (2.3-5.3)), ventricular septal defect (OR: 4.4 (3.2-6.1)), cardiogenic shock (OR: 1.7 (1.3-2.3)), sepsis (OR: 3.2 (1.9-5.4)), and left bundle branch block (OR: 3.5 (3-4)), compared to ASA. Patients who underwent ASA had higher post-procedure complete heart block (OR: 1.3 (1.1-1.4)), right bundle branch block (OR: 6.3 (5-7.7)), ventricular tachycardia (OR: 2.2 (1.9-2.6)), supraventricular tachycardia (OR: 1.6 (1.4-2)), and more commonly required pacemaker insertion (OR: 1.4 (1.3-1.7)) (p < 0.001 for all) compared to SM. This nationwide analysis evidenced that patients undergoing SM had higher in-hospital mortality and periprocedural complications than ASA; however, those undergoing ASA had more post-procedure conduction abnormalities and pacemaker implantation. The implications of these findings warrant further investigation regarding patient selection strategies for these therapies.

Integrating high-throughput analysis to create an atlas of replication origins in Trypanosoma cruzi in the context of genome structure and variability.

Trypanosoma cruzi is the etiologic agent of the most prevalent human parasitic disease in Latin America, Chagas disease. Its genome is rich in multigenic families that code for virulent antigens and are present in the rapidly evolving genomic compartment named Disruptive. DNA replication is a meticulous biological process in which flaws can generate mutations and changes in chromosomal and gene copy numbers. Here, integrating high-throughput and single-molecule analyses, we were able to identify Predominant, Flexible, and Dormant Orc1Cdc6-dependent origins as well as Orc1Cdc6-independent origins. Orc1Cdc6-dependent origins were found in multigenic family loci, while independent origins were found in the Core compartment that contains conserved and hypothetical protein-coding genes, in addition to multigenic families. In addition, we found that Orc1Cdc6 density is related to the firing of origins and that Orc1Cdc6-binding sites within fired origins are depleted of a specific class of nucleosomes that we previously categorized as dynamic. Together, these data suggest that Orc1Cdc6-dependent origins may contribute to the rapid evolution of the Disruptive compartment and, therefore, to the success of T. cruzi infection and that the local epigenome landscape is also involved in this process.IMPORTANCETrypanosoma cruzi, responsible for Chagas disease, affects millions globally, particularly in Latin America. Lack of vaccine or treatment underscores the need for research. Parasite's genome, with virulent antigen-coding multigenic families, resides in the rapidly evolving Disruptive compartment. Study sheds light on the parasite's dynamic DNA replication, discussing the evolution of the Disruptive compartment. Therefore, the findings represent a significant stride in comprehending T. cruzi's biology and the molecular bases that contribute to the success of infection caused by this parasite.

Epidemiology of the SARS-CoV-2 Omicron Variant Emergence in the Southeast Brazilian Population.

The aim of this study was to describe epidemiological characteristics and perform SARS-CoV-2 genomic surveillance in the southeastern region of São Paulo State. During the first months of 2022, we compared weekly SARS-CoV-2 infection prevalence considering age, Ct value, and variants' lineages. An increase in the number of SARS-CoV-2-positive cases until the fourth epidemiological week of 2022 was observed. From the fourth epidemiological week onwards, the number of tests for SARS-CoV-2 diagnosis began to decrease, but the number of positive samples for SARS-CoV-2 remained high, reaching its most expressive level with a rate of 60% of infected individual cases. In this period, we observed a progressive increase in SARS-CoV-2 infection within the 0-10 age group throughout the epidemiological weeks, from 2.8% in the first epidemiological week to 9.2% in the eighth epidemiological week of 2022. We further observed significantly higher Ct values within younger patient samples compared to other older age groups. According to lineage assignment, SARS-CoV-2 (BA.1) was the most prevalent (74.5%) in the younger group, followed by BA.1.1 (23%), BA.2 (1.7%), and Delta (1%). Phylogenetic analysis showed that BA.2 sequences clustered together, indicating sustained transmission of this Omicron VOC sub-lineage by that time. Our results suggest the initial dissemination steps of the Omicron's sub-linage BA.2 into the younger group, due to specific genomic features of the detected sequences. These data provide interesting results related to the spread, emergence, and evolution of the Omicron variant in the southeast Brazilian population.

Trends and In-Hospital Outcomes of Patients With Baseline Right Bundle Branch Block Who Underwent Transcatheter Aortic Valve Implantation.

This study aimed to explore contemporary in-hospital outcomes and trends of transcatheter aortic valve implantation (TAVI) outcomes in patients with baseline right bundle branch block (RBBB) using data collected from a nationwide sample. Using the National Inpatient Sample, we identified patients hospitalized for an index TAVI procedure from 2016 to 2019. Primary outcomes included in-hospital all-cause mortality, complete heart block, and permanent pacemaker (PPM) implantation. A total of 199,895 hospitalizations for TAVI were identified. RBBB was present in 10,495 cases (5.3%). Patients with RBBB were older (median age 81 vs 80 years, p <0.001) and less likely to be female (35% vs 47.4%, p <0.001). After adjusting for differences in baseline characteristics and elective versus nonelective admission, patients with RBBB had a higher incidence of complete heart block (adjusted odds ratio [aOR] 4.77, confidence interval [CI] 4.55 to 5.01, p <0.001) and PPM implantation (aOR 4.15, CI 3.95 to 4.35, p <0.001) and no difference in-hospital mortality rate (aOR 0.85, CI 0.69 to 1.05, p = 0.137). Between 2016 and 2019, there was a 3.5% and 2.9% decrease in in-hospital PPM implantation in patients with and without RBBB, respectively. In conclusion, from 2016 to 2019, the rate of in-hospital PPM implantation decreased during index TAVI hospitalization in both patients with and without RBBB. However, in those with baseline RBBB, complete heart block complication rates requiring PPM implantation remain relatively high. Further research and advances are needed to continue to reduce complication rates and the need for PPM implantation.

Comparing morphological and secretory aspects of cephalic glands among the New World coral snakes brings novel insights on their biological roles.

Oral and other cephalic glands have been surveyed by several studies with distinct purposes. Despite the wide diversity and medical relevance of the New World coral snakes, studies focusing on understanding the biological roles of the glands within this group are still scarce. Specifically, the venom glands of some coral snakes were previously investigated but all other cephalic glands remain uncharacterized. In this sense, performing morphological and molecular analysis of these glands may help better understand their biological role. Here, we studied the morphology of the venom, infralabial, rictal, and harderian glands of thirteen species of Micrurus and Micruroides euryxanthus. We also performed a molecular characterization of these glands from selected species of Micrurus using transcriptomic and proteomic approaches. We described substantial morphological variation in the cephalic glands of New World coral snakes and structural evidence for protein-secreting cells in the inferior rictal glands. Our molecular analysis revealed that the venom glands, as expected, are majorly devoted to toxin production, however, the infralabial and inferior rictal glands also expressed some toxin genes at low to medium levels, despite the marked morphological differences. On the other hand, the harderian glands were dominated by the expression of lipocalins, but do not produce toxins. Our integrative analysis, including the prediction of biological processes and pathways, helped decipher some important traits of cephalic glands and better understand their biology.

SARS-CoV-2 Rapid Antigen Test Based on a New Anti-Nucleocapsid Protein Monoclonal Antibody: Development and Real-Time Validation.

SARS-CoV-2 diagnostic tests have become an important tool for pandemic control. Among the alternatives for COVID-19 diagnosis, antigen rapid diagnostic tests (Ag-RDT) are very convenient and widely used. However, as SARS-CoV-2 variants may continuously emerge, the replacement of tests and reagents may be required to maintain the sensitivity of Ag-RDTs. Here, we describe the development and validation of an Ag-RDT during an outbreak of the Omicron variant, including the characterization of a new monoclonal antibody (anti-DTC-N 1B3 mAb) that recognizes the Nucleocapsid protein (N). The anti-DTC-N 1B3 mAb recognized the sequence TFPPTEPKKDKKK located at the C-terminus of the N protein of main SARS-CoV-2 variants of concern. Accordingly, the Ag-RDT prototypes using the anti-DTC-N 1B3 mAB detected all the SARS-CoV-2 variants-Wuhan, Alpha, Gamma, Delta, P2 and Omicron. The performance of the best prototype (sensitivity of 95.2% for samples with Ct ≤ 25; specificity of 98.3% and overall accuracy of 85.0%) met the WHO recommendations. Moreover, results from a patients' follow-up study indicated that, if performed within the first three days after onset of symptoms, the Ag-RDT displayed 100% sensitivity. Thus, the new mAb and the Ag-RDT developed herein may constitute alternative tools for COVID-19 point-of-care diagnosis and epidemiological surveillance.

Retrospective Insights of the COVID-19 Epidemic in the Major Latin American City, São Paulo, Southeastern Brazil.

São Paulo is the financial center of Brazil, with a population of over 12 million, that receives travelers from all over the world for business and tourism. It was the first city in Brazil to report a case of COVID-19 that rapidly spread across the city despite the implementation of the restriction measures. Despite many reports, much is still unknown regarding the genomic diversity and transmission dynamics of this virus in the city of São Paulo. Thus, in this study, we provide a retrospective overview of the COVID-19 epidemic in São Paulo City, Southeastern, Brazil, by generating a total of 9995 near-complete genome sequences from all the city's different macro-regions (North, West, Central, East, South, and Southeast). Our analysis revealed that multiple independent introduction events of different variants (mainly Gamma, Delta, and Omicron) occurred throughout time. Additionally, our estimates of viral movement within the different macro-regions further suggested that the East and the Southeast regions were the largest contributors to the Gamma and Delta viral exchanges to other regions. Meanwhile, the North region had a higher contribution to the dispersion of the Omicron variant. Together, our results reinforce the importance of increasing SARS-CoV-2 genomic monitoring within the city and the country to track the real-time evolution of the virus and to detect earlier any eventual emergency of new variants of concern that could undermine the fight against COVID-19 in Brazil and worldwide.

Comparison of In-Hospital Outcomes and Readmission Rates of Transcatheter Aortic Valve Implantation in Mixed Aortic Valve Disease Versus Pure Aortic Stenosis.

Recently, transcatheter aortic valve implantation (TAVI) has been performed in patients with combined aortic stenosis (AS) and aortic regurgitation. We sought to evaluate in-hospital outcomes and readmission rates after TAVI in patients with mixed aortic valve disease (MAVD). A total of 100,573 TAVI procedures were identified between 2011 and 2017 using International Classification of Diseases, Ninth Revision and International Classification of Diseases, Tenth Revision procedure codes the from Nationwide Readmissions Database. We separated patients into 2 cohorts, those with MAVD and those with pure AS. The primary outcome was all-cause inpatient mortality after TAVI, and secondary outcomes included rates of 30- and 90-day readmissions and postprocedural complications. A total of 3,260 patients had MAVD (median age 83 years, 43.5% women). In-hospital mortality (2.5% vs 2.6%, p = 0.531) and rates of paravalvular leak (1.0% vs 1.3%, p = 0.056) were similar between the MAVD and pure AS groups. Major bleeding (7.4% vs 9.6%, p <0.001), 30-day readmission (0.5% vs 8.8%, p <0.001) and 90-day readmission rates (0.8% vs 16.0%, p <0.001), acute kidney injury (12.9% vs 15.1%, p <0.001), postoperative ischemic stroke (2.0% vs 5.7%, p <0.001), and mechanic circulatory support use (1.9% vs 4.5%, p <0.001) were less prevalent in the MAVD cohort. Using a multivariate logistic regression model to adjust for confounding factors, MAVD was not predictive of mortality in patients who underwent TAVI (adjusted odds ratio [adjOR] 1.25, 95% confidence interval [CI] 0.99 to 1.57, p = 0.056); however, MAVD was associated with: decreased odds of 30-day readmission (adjOR 0.05, 95% CI 0.03 to 0.08, p <0.001), 90-day readmission rates (adjOR 0.04, 95% CI 0.03 to 0.06, p <0.001), and higher odds of pacemaker implantation (adjOR 1.46, 95% CI 1.29 to 1.65, p <0.001). In conclusion, despite differences in the aortic valve and left ventricular anatomy (pressure vs volume-related adaptive changes) in patients with MAVD and pure AS, TAVI appears safe and feasible. However, patients with MAVD were more likely to have permanent pacemakers implanted. The results of our study warrant further randomized controlled studies to confirm these findings.