CASP4/11 Contributes to NLRP3 Activation and COVID-19 Exacerbation.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection triggers activation of the NLRP3 inflammasome, which promotes inflammation and aggravates severe COVID-19. Here, we report that SARS-CoV-2 induces upregulation and activation of human caspase-4/CASP4 (mouse caspase-11/CASP11), and this process contributes to NLRP3 activation. In vivo infections performed in transgenic hACE2 humanized mice, deficient or sufficient for Casp11, indicate that hACE2 Casp11-/- mice were protected from disease development, with the increased pulmonary parenchymal area, reduced clinical score of the disease, and reduced mortality. Assessing human samples from fatal cases of COVID-19, we found that CASP4 was expressed in patient lungs and correlated with the expression of inflammasome components and inflammatory mediators, including CASP1, IL1B, IL18, and IL6. Collectively, our data establish that CASP4/11 promotes NLRP3 activation and disease pathology, revealing a possible target for therapeutic interventions for COVID-19.

Secondary respiratory early and late infections in mechanically ventilated patients with COVID-19.

BACKGROUND: Patients with COVID-19 receiving mechanical ventilation may become aggravated with a secondary respiratory infection. The aim of this study was to describe secondary respiratory infections, their predictive factors, and outcomes in patients with COVID-19 requiring mechanical ventilation. METHODS: A cohort study was carried out in a single tertiary hospital in Santiago, Chile, from 1st June to 31st July 2020. All patients with COVID-19 admitted to the intensive care unit that required mechanical ventilation were included. RESULTS: A total of 175 patients were enrolled, of which 71 (40.6%) developed at least one secondary respiratory infection during follow-up. Early and late secondary infections were diagnosed in 1.7% and 31.4% respectively. Within late secondary infections, 88% were bacterial, 10% were fungal, and 2% were of viral origin. One-third of isolated bacteria were multidrug-resistant. Bivariate analysis showed that the history of corticosteroids used before admission and the use of dexamethasone during hospitalization were associated with a higher risk of secondary infections (p = 0.041 and p = 0.019 respectively). Multivariate analysis showed that for each additional day of mechanical ventilation, the risk of secondary infection increases 1.1 times (adOR = 1.07; 95% CI 1.02-1.13, p = 0.008) CONCLUSIONS: Patients with COVID-19 admitted to the intensive care unit and requiring mechanical ventilation had a high rate of secondary infections during their hospital stay. The number of days on MV was a risk factor for acquiring secondary respiratory infections.

Identification of immunomodulatory drugs that inhibit multiple inflammasomes and impair SARS-CoV-2 infection.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) induces mild or asymptomatic COVID-19 in most cases, but some patients develop an excessive inflammatory process that can be fatal. As the NLRP3 inflammasome and additional inflammasomes are implicated in disease aggravation, drug repositioning to target inflammasomes emerges as a strategy to treat COVID-19. Here, we performed a high-throughput screening using a 2560 small-molecule compound library and identified FDA-approved drugs that function as pan-inflammasome inhibitors. Our best hit, niclosamide (NIC), effectively inhibits both inflammasome activation and SARS-CoV-2 replication. Mechanistically, induction of autophagy by NIC partially accounts for inhibition of NLRP3 and AIM2 inflammasomes, but NIC-mediated inhibition of NAIP/NLRC4 inflammasome are autophagy independent. NIC potently inhibited inflammasome activation in human monocytes infected in vitro, in PBMCs from patients with COVID-19, and in vivo in a mouse model of SARS-CoV-2 infection. This study provides relevant information regarding the immunomodulatory functions of this promising drug for COVID-19 treatment.

Monitoring SARS-CoV-2 in the Wastewater and Rivers of Tapachula, a Migratory Hub in Southern Mexico.

The COVID-19 pandemic has been monitored by applying different strategies, including SARS-CoV-2 detection with clinical testing or through wastewater-based epidemiology (WBE). We used the latter approach to follow SARS-CoV-2 dispersion in Tapachula city, located in Mexico's tropical southern border region. Tapachula is a dynamic entry point for people seeking asylum in Mexico or traveling to the USA. Clinical testing facilities for SARS-CoV-2 monitoring are limited in the city. A total of eighty water samples were collected from urban and suburban rivers and sewage and a wastewater treatment plant over 4 months in Tapachula. We concentrated viral particles with a PEG-8000-based method, performed RNA extraction, and detected SARS-CoV-2 particles through RT-PCR. We considered the pepper mild mottle virus as a fecal water pollution biomarker and analytical control. SARS-CoV-2 viral loads (N1 and N2 markers) were quantified and correlated with official regional statistics of COVID-19 bed occupancy and confirmed cases (r > 91%). Our results concluded that WBE proved a valuable tool for tracing and tracking the COVID-19 pandemic in tropical countries with similar water temperatures (21-29 °C). Monitoring SARS-CoV-2 through urban and suburban river water sampling would be helpful in places lacking a wastewater treatment plant or water bodies with sewage discharges.

A Consensus Algorithm for Multi-Objective Battery Balancing

Batteries stacks are made of cells in certain series-parallel arrangements. Unfortunately, cell performance degrades over time in terms of capacity, internal resistance, or self-discharge rate. In addition, degradation rates are heterogeneous, leading to cell-to-cell variations. Balancing systems can be used to equalize those differences. Dissipative or non-dissipative systems, so-called passive or active balancing, can be used to equalize either voltage at end-of-charge, or state-of-charge (SOC) at all times. While passive balancing is broadly adopted by industry, active balancing has been mostly studied in academia. Beyond that, an emerging research field is multi-functional balancing, i.e., active balancing systems that pursue additional goals on top of SOC equalization, such as equalization of temperature, power capability, degradation rates, or losses minimization. Regardless of their functionality, balancing circuits are based either on centralized or decentralized control systems. Centralized control entails difficult expandability and single point of failure issues, while decentralized control has severe controllability limitations. As a shift in this paradigm, here we present for the first time a distributed multi-objective control algorithm, based on a multi-agent consensus algorithm. We implement and validate the control in simulations, considering an electro-thermal lithium-ion battery model and an electric vehicle model parameterized with experimental data. Our results show that our novel multi-functional balancing can enhance the performance of batteries with substantial cell-to-cell differences under the most demanding operating conditions, i.e., aggressive driving and DC fast charging (2C). Driving times are extended (>10%), charging times are reduced (>20%), maximum cell temperatures are decreased (>10 °C), temperature differences are lowered (~3 °C rms), and the occurrence of low voltage violations during driving is reduced (>5×), minimizing the need for power derating and enhancing the user experience. The algorithm is effective, scalable, flexible, and requires low implementation and tuning effort, resulting in an ideal candidate for industry adoption.

Intubation timing as determinant of outcome in patients with acute respiratory distress syndrome by SARS-CoV-2 infection.

PURPOSE: To determine whether time-to-intubation was associated with higher ICU mortality in patients with COVID-19 on mechanical ventilation due to respiratory insufficiency. MATERIALS AND METHODS: We conducted an observational, prospective, single-center study of patients with confirmed SARS-CoV-2 infection hospitalized with moderate to severe ARDS, connected to mechanical ventilation in the ICU between March 17 and July 31, 2020. We examined their general and clinical characteristics. Time-to-intubation was the time from hospital admission to endotracheal intubation. RESULTS: We included 183 consecutive patients; 28% were female, and median age was 62 years old. Eighty-eight patients (48%) were intubated before 48 h (early) and ninety-five (52%) after 48 h (late). Patients intubated early had similar admission PaO2/FiO2 ratio (123 vs 99; p = 0.179) but were younger (59 vs 64; p = 0.013) and had higher body mass index (30 vs 28; p = 0.006) compared to patients intubated late. Mortality was higher in patients intubated late (18% versus 43%), with admission PaO2/FiO2 ratio < 100 mmHg (OR 5.2; p = 0.011), of older age (OR 1.1; p = 0.001), and with previous use of ACE inhibitors (OR 4.8; p = 0.026). CONCLUSIONS: In COVID-19 patients, late intubation, Pafi <100, older age, and previous ACE inhibitors use were associated with increased ICU mortality.

Fallacy of the last bed dilemma.

The COVID-19 pandemic highlights the relevance of adequate decision making at both public health and healthcare levels. A bioethical response to the demand for medical care, supplies and access to critical care is needed. Ethically sound strategies are required for the allocation of increasingly scarce resources, such as rationing critical care beds. In this regard, it is worth mentioning the so-called 'last bed dilemma'. In this paper, we examine this dilemma, pointing out the main criteria used to solve it and argue that we cannot face these ethical issues as though they are only a dilemma. A more complex ethical view regarding the care of COVID-19 patients that is focused on proportional and ordinary treatments is required. Furthermore, discussions and forward planning are essential because deliberation becomes extremely complex during an emergency and the physicians' sense of responsibility may be increased if it is faced only as a moral dilemma.

COVID-19: Is reinfection possible?

The COVID-19 pandemic has spread rapidly in many countries, overburdening health systems and causing numerous economic and social impacts. Most studies on the subject have focused on epidemiology, diagnosis, and treatment, however, there remains a scientific gap concerning the possibility of reinfection. The purpose of this bibliographic review is to gather information from studies aimed at this possibility, and to clarify what we know so far. It was found that in many situations cured patients are being released from hospitals, however, in some cases, the discharge criteria are not effective. Patients are presenting positive RT-PCR tests. There are several factors that might interfere so that patients cured of COVID-19 continue to test positive, and this would not necessarily represent a case of recurrence, as the test cannot differentiate the viral RNA from the complete virus, which alone is capable of causing the active infection. This review demonstrates that in order to rule out the possibility of COVID-19 reinfection in cured patients, more robust methods need to be adopted as criteria for both clinical discharge and post-hospital follow-up.

Early versus deferred anti-SARS-CoV-2 convalescent plasma in patients admitted for COVID-19: A randomized phase II clinical trial.

BACKGROUND: Convalescent plasma (CP), despite limited evidence on its efficacy, is being widely used as a compassionate therapy for hospitalized patients with COVID-19. We aimed to evaluate the efficacy and safety of early CP therapy in COVID-19 progression. METHODS AND FINDINGS: The study was an open-label, single-center randomized clinical trial performed in an academic medical center in Santiago, Chile, from May 10, 2020, to July 18, 2020, with final follow-up until August 17, 2020. The trial included patients hospitalized within the first 7 days of COVID-19 symptom onset, presenting risk factors for illness progression and not on mechanical ventilation. The intervention consisted of immediate CP (early plasma group) versus no CP unless developing prespecified criteria of deterioration (deferred plasma group). Additional standard treatment was allowed in both arms. The primary outcome was a composite of mechanical ventilation, hospitalization for >14 days, or death. The key secondary outcomes included time to respiratory failure, days of mechanical ventilation, hospital length of stay, mortality at 30 days, and SARS-CoV-2 real-time PCR clearance rate. Of 58 randomized patients (mean age, 65.8 years; 50% male), 57 (98.3%) completed the trial. A total of 13 (43.3%) participants from the deferred group received plasma based on clinical aggravation. We failed to find benefit in the primary outcome (32.1% versus 33.3%, odds ratio [OR] 0.95, 95% CI 0.32-2.84, p > 0.999) in the early versus deferred CP group. The in-hospital mortality rate was 17.9% versus 6.7% (OR 3.04, 95% CI 0.54-17.17 p = 0.246), mechanical ventilation 17.9% versus 6.7% (OR 3.04, 95% CI 0.54-17.17, p = 0.246), and prolonged hospitalization 21.4% versus 30.0% (OR 0.64, 95% CI, 0.19-2.10, p = 0.554) in the early versus deferred CP group, respectively. The viral clearance rate on day 3 (26% versus 8%, p = 0.204) and day 7 (38% versus 19%, p = 0.374) did not differ between groups. Two patients experienced serious adverse events within 6 hours after plasma transfusion. The main limitation of this study is the lack of statistical power to detect a smaller but clinically relevant therapeutic effect of CP, as well as not having confirmed neutralizing antibodies in donor before plasma infusion. CONCLUSIONS: In the present study, we failed to find evidence of benefit in mortality, length of hospitalization, or mechanical ventilation requirement by immediate addition of CP therapy in the early stages of COVID-19 compared to its use only in case of patient deterioration. TRIAL REGISTRATION: NCT04375098.

COVID-19-Related Challenges in Dental Education: Experiences From Brazil, the USA, and Australia

Objective: To describe and compare how three dental schools from different countries (Australia, Brazil, and the USA) have managed experiences in dental education during the COVID-19 crisis. Material and Methods: It is a descriptive study reporting the experience that three distinct dental schools faced during the COVID-19 pandemic. They represent countries that adopted different measures to tackle the pandemic and were undergoing different stages of the disease. Results: After the WHO declared the COVID-19 pandemic, the Federal University of Paraíba suspended all on-site teaching, research, and service activities. For the return to teaching activities, the use of information and communications technology resources for distance learning was recommended. At the School of Dental Medicine (University of Pittsburgh), all research activities were suspended or, otherwise, could not be interrupted because of the employment of unique materials or supplies. When the pandemic started, Australia was one of the first countries to introduce strong regulations related to social distancing, travel restrictions, testing and tracking of infected patients. As such, the universities started to be closed from mid-March, cancelling all clinical and pre-clinical activities, maintaining online theoretical activities, such as seminars, lectures, and journal clubs. Conclusion: Numerous and critical difficulties have arisen as a result of the pandemic for individuals, communities and institutions that will have long-lasting effects. Our students face disruption to their education and career;our professional colleagues will be challenged rebuilding their practices, while staff at all Dental Schools are experiencing various hardships.

Inflammasomes are activated in response to SARS-CoV-2 infection and are associated with COVID-19 severity in patients.

Severe cases of COVID-19 are characterized by a strong inflammatory process that may ultimately lead to organ failure and patient death. The NLRP3 inflammasome is a molecular platform that promotes inflammation via cleavage and activation of key inflammatory molecules including active caspase-1 (Casp1p20), IL-1ß, and IL-18. Although participation of the inflammasome in COVID-19 has been highly speculated, the inflammasome activation and participation in the outcome of the disease are unknown. Here we demonstrate that the NLRP3 inflammasome is activated in response to SARS-CoV-2 infection and is active in COVID-19 patients. Studying moderate and severe COVID-19 patients, we found active NLRP3 inflammasome in PBMCs and tissues of postmortem patients upon autopsy. Inflammasome-derived products such as Casp1p20 and IL-18 in the sera correlated with the markers of COVID-19 severity, including IL-6 and LDH. Moreover, higher levels of IL-18 and Casp1p20 are associated with disease severity and poor clinical outcome. Our results suggest that inflammasomes participate in the pathophysiology of the disease, indicating that these platforms might be a marker of disease severity and a potential therapeutic target for COVID-19.

Orientaciones éticas para la toma de decisiones médicas en el contexto de la pandemia de COVID-19 en Chile

The catastrophic emergency experienced by many countries with the COVID-19 pandemic emphasized the importance of bioethics for decision-making, both at the public health (equitable and effective policies) and at the clinical level. At the clinical level, the issues are the fulfillment of medical care demand with adequate health care teams, infrastructure, and supplies, and to cover critical care demands that surpass the available resources. Therefore, ethically correct approaches are required for the allocation of life sustaining resources. There are recommendations for the allocating life support during disasters based on multiple considerations, including ethical ones. However, the ethical criteria of existing guidelines are variable. Ethical principles usually considered are saving the greatest number of lives, saving the greatest number of years of life and the principle of the life cycle or the goal to give each individual equal opportunity to live through the various phases of life. However, the centrality of the human being and the search for the common good should be considered. Knowledge of public perspectives and moral benchmarks on these issues is essential. A successful assignment effort will require everyone's trust and cooperation. Decision making should be planned and discussed in advance, since in-depth deliberation will be extremely complex during the disaster. Our goal is to help the health care teams to wisely allocate resources in shortage periods.

[Ethical guidelines for medical decision-making during COVID-19 pandemic in Chile]. / Orientaciones éticas para la toma de decisiones médicas en el contexto de la pandemia de COVID-19 en Chile.

The catastrophic emergency experienced by many countries with the COVID-19 pandemic emphasized the importance of bioethics for decision-making, both at the public health (equitable and effective policies) and at the clinical level. At the clinical level, the issues are the fulfillment of medical care demand with adequate health care teams, infrastructure, and supplies, and to cover critical care demands that surpass the available resources. Therefore, ethically correct approaches are required for the allocation of life sustaining resources. There are recommendations for the allocating life support during disasters based on multiple considerations, including ethical ones. However, the ethical criteria of existing guidelines are variable. Ethical principles usually considered are saving the greatest number of lives, saving the greatest number of years of life and the principle of the life cycle or the goal to give each individual equal opportunity to live through the various phases of life. However, the centrality of the human being and the search for the common good should be considered. Knowledge of public perspectives and moral benchmarks on these issues is essential. A successful assignment effort will require everyone's trust and cooperation. Decision making should be planned and discussed in advance, since in-depth deliberation will be extremely complex during the disaster. Our goal is to help the health care teams to wisely allocate resources in shortage periods.