Pathophysiology of coronavirus-19 disease acute lung injury

FOT Technique Applied for Monitoring of COVID-19 Pneumonia Reveals Small Airways Involvement

The fact that some SARS-CoV-2 pneumonia patients benefit from changing body position, and some from continuous positive airways pressure (CPAP), indicates the functional character of hypoxia. We hypothesize that such effects could be explained by the closure of small airways. To prove the hypothesis, we evaluated the patency of small airways in 30 oxygen-dependent, spontaneously breathing patients with SARS-CoV-2 pneumonia during their hospital stay using the FOT method and then compared the results with data obtained three months later. During the acute period, total resistance (R5) and peripheral resistance (R5-20) rose above the upper limit of normal (ULN) in 28% and 50% of all patients, respectively. Reactance indices X5, AX and Fres exceeded ULN in 55%, 68% and 66% of cases. Significant correlations were observed between PaO2/FiO2, the time spent in the hospital and R5, X5, AX and Fres. After 3 months, 18 patients were re-examined. During the hospital stay, 11 of them had risen above the upper limit of normal (ULN), for both resistance (R5-20) and reactance (X5, AX) values. Three months later, ULN for R5-20 was exceeded in only four individuals, but ULN for X5 and AX was exceeded in five individuals. Lung function examination revealed a combined restrictive/obstructive ventilatory failure and reduced CO transfer factor. We interpret these changes as lung tissue remodeling due to the process of fibrosis. We conclude that during acute period of SARS-CoV-2 pneumonia, dilated pulmonary blood vessels and parenchymal oedema induce functional closure of small airways, which in turn induce atelectasis with pulmonary right-to-left shunting, followed by the resulting hypoxemia.

Prediction of acute lung injury assessed by chest computed tomography, oxygen saturation/fraction of inspired oxygen ratio, and serum lactate dehydrogenase in patients with COVID-19

INTRODUCTION

In treating acute hypoxemic respiratory failure (AHRF) caused by coronavirus disease 2019 (COVID-19), clinicians choose respiratory therapies such as low-flow nasal cannula oxygenation, high-flow nasal cannula oxygenation, or mechanical ventilation after assessment of the patient's condition. Chest computed tomography (CT) imaging contributes significantly to diagnosing COVID-19 pneumonia. However, the costs and potential harm to patients from radiation exposure need to be considered. This study was performed to predict the quantitative extent of COVID-19 acute lung injury using clinical indicators such as an oxygenation index and blood test results.

METHODS

We analyzed data from 192 patients with COVID-19 AHRF. Multiple logistic regression was used to determine correlations between the lung infiltration volume (LIV) and other pathophysiological or biochemical laboratory parameters.

RESULTS

Among 13 clinical parameters, we identified the oxygen saturation/fraction of inspired oxygen ratio (SF ratio) and serum lactate dehydrogenase (LD) concentration as factors associated with the LIV. In the binary classification of an LIV of ≥20 % or not and with the borderline LD = 2.2 × [SF ratio]-182.4, the accuracy, precision, diagnostic odds ratio, and area under the summary receiver operating characteristic curve were 0.828, 0.818, 23.400, and 0.870, respectively.

CONCLUSIONS

These data suggest that acute lung injury due to COVID-19 pneumonia can be estimated using the SF ratio and LD concentration without a CT scan. These findings may provide significant clinical benefit by allowing clinicians to predict acute lung injury levels using simple, minimally invasive assessment of oxygenation capacity and biochemical blood tests.

ANALYSIS AND IDENTIFICATION OF FERROPTOSIS-RELATED GENE SIGNATURE FOR ACUTE LUNG INJURY

ABSTRACT

Background: Recent studies have shown that ferroptosis is involved in the evolution of acute lung injury (ALI), a serious respiratory pathological process leading to death. However, the regulatory mechanisms underlying ferroptosis in ALI remain largely unknown. The current study analyzed and identified a ferroptosis-related gene signature for ALI. Methods: Key genes associated with ferroptosis in ALI were identified by bioinformatics analysis. GSE104214, GSE18341, and GSE17355 datasets were downloaded from the Gene Expression Omnibus database. The signature genes were screened by least absolute shrinkage and selection operator regression, and the key genes of ALI were screened by weighted correlation network analysis (WGCNA), followed by immune infiltration analysis and functional enrichment analysis. In addition, mRNA expression of key genes in the lungs of mice with hemorrhagic shock (HS) and sepsis was verified. Results: A total of 2,132 differential genes were identified by various analyses, and 9 characteristic genes were detected using Lasso regression. We intersected nine signature genes with WGCNA module genes and finally determined four key genes ( PROK2 , IL6 , TNF , SLC7A11 ). All four key genes were closely correlated with immune cells and regulatory genes of ALI, and the expression of the four genes was significantly different in the lung tissues of HS and sepsis models. Besides, the ferroptosis-related molecules GPX4 and ACSL4 showed remarkable difference in these models. Conclusion: These results indicate that PROK2 , IL6 , TNF , and SLC7A11 may be key regulatory targets of ferroptosis during ALI. This study proved that ferroptosis is a common pathophysiological process in three ALI models.

Modulation of alveolar macrophage and mitochondrial fitness by medicinal plant-derived nanovesicles to mitigate acute lung injury and viral pneumonia

Acute lung injury (ALI) is generally caused by severe respiratory infection and characterized by overexuberant inflammatory responses and inefficient pathogens-containing, the two major processes wherein alveolar macrophages (AMs) play a central role. Dysfunctional mitochondria have been linked with distorted macrophages and hence lung disorders, but few treatments are currently available to correct these defects. Plant-derive nanovesicles have gained significant attention because of their therapeutic potential, but the targeting cells and the underlying mechanism remain elusive. We herein prepared the nanovesicles from Artemisia annua, a well-known medicinal plant with multiple attributes involving anti-inflammatory, anti-infection, and metabolism-regulating properties. By applying three mice models of acute lung injury caused by bacterial endotoxin, influenza A virus (IAV) and SARS-CoV-2 pseudovirus respectively, we showed that Artemisia-derived nanovesicles (ADNVs) substantially alleviated lung immunopathology and raised the survival rate of challenged mice. Macrophage depletion and adoptive transfer studies confirmed the requirement of AMs for ADNVs effects. We identified that gamma-aminobutyric acid (GABA) enclosed in the vesicles is a major molecular effector mediating the regulatory roles of ADNVs. Specifically, GABA acts on macrophages through GABA receptors, promoting mitochondrial gene programming and bioenergy generation, reducing oxidative stress and inflammatory signals, thereby enhancing the adaptability of AMs to inflammation resolution. Collectively, this study identifies a promising nanotherapeutics for alleviating lung pathology, and elucidates a mechanism whereby the canonical neurotransmitter modifies AMs and mitochondria to resume tissue homeostasis, which may have broader implications for treating critical pulmonary diseases such as COVID-19.

Early pandemic in-hospital outcomes and mortality risk factors in COVID-19 solid organ transplant patients

Background

Solid organ transplant (SOT) recipients with COVID-19 have a higher risk of mortality than those without COVID-19. However, it is unclear how SOT patient outcomes compare to the general population without SOT who contract COVID-19.

Methods

We used the National Inpatient Sample from January to December 2020 to investigate inpatient outcomes seen in SOT recipients after contracting COVID-19 compared to nontransplant patients. We identified our study sample using ICD-10 CM and excluded those <18 years of age and those with dual organ transplants. Inpatient outcomes were compared in SOT and non-SOT COVID cohorts, and we further evaluated predictors of mortality in the SOT with COVID population.

Results

Out of the 1,416,445 COVID-19 admissions included in the study, 8315 (0.59%) were single SOT recipients. Our analysis that adjusted for multiple baseline characteristics and comorbidities demonstrated that COVID-19 in SOT patients was associated with higher rates of acute kidney injury (adjusted odds ratio [aOR] 2.34, 95% confidence interval [CI] 1.81-3.02, P < 0.01), lower rates of acute respiratory distress syndrome (aOR 0.68, 95% CI 0.54-0.85, P < 0.01), and similar rates of cardiac arrest, pulmonary embolism, circulatory shock, cerebrovascular events, and in-hospital mortality. Age >65 was associated with mortality in SOT patients.

Conclusion

In this nationally representative sample, SOT patients presenting with COVID-19 experienced similar rates of mortality compared to those without SOT. SOT patients were more likely to develop acute kidney injury. Further research is needed to understand the complex relationship between transplant patient outcomes and COVID-19.

Role of epinephrine in attenuating cytokine storm, decreasing ferritin, and inhibiting ferroptosis in SARS-CoV-2

BACKGROUND

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the virus responsible for coronavirus disease 2019. It presents one of the most threatening pandemics in the history of humanity. The mortality and morbidity represent an unprecedented challenge to the modern medical era. SARS-CoV-2 results in acute respiratory distress syndrome, high concentrations of proinflammatory mediators, cytokine storm (CS) due to massive release of cytokines, hypercoagulation, and hemoglobin disintegration. Dysregulation of iron homeostasis, iron overload as indicated by high ferritin level, and ferroptosis are major factors in the pathogenesis of the disease. We report a case of SARS-CoV-2 in which the use of epinephrine (Epi) resulted in an unexpected attenuation of CS, decreasing ferritin level and inhibiting ferroptosis.

CASE PRESENTATION

A 64-year-old male patient with a history of multiple medical comorbidities had been diagnosed with SARS-CoV-2. Further evaluation showed marked increase in inflammatory markers, severe hyperferritinemia, and lymphopenia in laboratory blood tests. The characteristic score of CS was strongly positive, and in addition to regular treatment, the patient received Epi due to development of acute generalized skin rash, severe itching, and edema of lips and tongue. Epi may have successfully terminated not only the acute cutaneous condition, but also have attenuated CS, decreased ferritin level, and other inflammatory markers in addition to complete patient's recovery.

CONCLUSION

Epinephrine may attenuate CS and inhibit ferroptosis which is an iron-dependent, non-apoptotic mode of cell death. Epi interacts with ferric and/or ferrous iron and built a stable complex that impedes activation of beta-adrenergic receptors. Epi may cause marked decrease of ferritin and other inflammatory markers. Epi may be used to decrease iron overload which is associated with many medical diseases like type 2 diabetes mellitus and cardiometabolic diseases such as coronary heart disease and cerebrovascular disease. As a new clinical indication extensive studies are required for further assessment and possible therapeutic uses.

Effects of driving pressure-guided ventilation on postoperative pulmonary complications in patients with COVID-19 undergoing abdominal surgery: A post-hoc propensity score-matched analysis

Background

Application of individualized positive end-expiratory pressure (PEEP) based on minimum driving pressure facilitates to prevent from postoperative pulmonary complications (PPCs). Whether lung protective ventilation strategy can reduce the risk of PPCs in COVID-19 patients remains unclear. In this study, we compared the effects of driving pressure-guided ventilation with conventional mechanical ventilation on PPCs in patients with COVID-19.

Methods

Patients infected COVID-19 within 30-day before surgery were retrospectively enrolled consecutively. Patients were divided into two group: driving pressure-guided lung protective ventilation strategy group (LPVS group) and conventional mechanical ventilation group (Control group). Propensity score matching for variables selected was used by logistic regression with the nearest-neighbor method. The outcomes were the incidence of PPCs and hypoxemia in post-anesthesia care unit.

Results

There was no significant difference in the baseline data between both groups (P > 0.05). The incidence of PPCs (12.73 % vs 36.36 %, χ2 = 7.068, P = 0.008) and hypoxemia [18.18 % vs 38.18 %, χ2 = 4.492, P = 0.034], and lung ultrasound scores [4.68 ± 1.60 vs 8.39 ± 1.87, t = 8.383, P < 0.001] in LPVS group were lower than control group. The PEEP, airway pressure and plateau pressure in LPVS group were higher than control group, but driving pressure and tidal volume was lower than control group, the difference was statistically significant (P < 0.05).

Conclusion

Individualized PEEP ventilation strategy guided by minimum driving pressure could improve oxygenation and reduce the incidence of PPCs in surgical patients with COVID-19.

The Influence of Autoimmune Thyroid Diseases on Viral Pneumonia Development, Including COVID-19: A Two-Sample Mendelian Randomization Study

The association between thyroid function and viral pneumonia has undergone extensive examination, yet the presence of a causal link remains uncertain. The objective of this paper was to employ Two-Sample Mendelian Randomization (MR) analysis to investigate the connections between three thyroid diseases and thyroid hormone indicators with viral pneumonia and COVID-19. We obtained summary statistics datasets from seven genome-wide association studies (GWASs). The primary method used for estimating relationships was inverse-variance weighting (IVW). In addition, we employed weighted median, weighted mode, MR-Egger, and MR-PRESSO as supplementary analytical tools. Sensitivity analyses encompassed Cochran's Q test, MR-Egger intercept test, and MR-PRESSO. Our study revealed significant causal relationships between having a genetic predisposition to autoimmune thyroid disease (AITD) and an increased susceptibility to viral pneumonia (odds ratio [OR]: 1.096; 95% confidence interval [CI]: 1.022-1.176). Moreover, it demonstrated a heightened susceptibility and severity of COVID-19 (OR for COVID-19 susceptibility, COVID-19 hospitalization, and COVID-19 critical illness, with 95% CIs of 1.016, 1.001-1.032; 1.058, 1.003-1.116; 1.045, 1.010-1.081). However, no statistically significant associations were found between TSH, FT4, subclinical hypo- or hyperthyroidism, and the risk of viral pneumonia incidence, or the susceptibility and severity of COVID-19 (all p > 0.05). This study establishes a cause-and-effect relationship between AITD and the development of viral pneumonia, as well as the susceptibility and severity of COVID-19.

Rapid assays of SARS-CoV-2 virus and noble biosensors by nanomaterials

The COVID-19 outbreak caused by SARS-CoV-2 in late 2019 has spread rapidly across the world to form a global epidemic of respiratory infectious diseases. Increased investigations on diagnostic tools are currently implemented to assist rapid identification of the virus because mass and rapid diagnosis might be the best way to prevent the outbreak of the virus. This critical review discusses the detection principles, fabrication techniques, and applications on the rapid detection of SARS-CoV-2 with three categories: rapid nuclear acid augmentation test, rapid immunoassay test and biosensors. Special efforts were put on enhancement of nanomaterials on biosensors for rapid, sensitive, and low-cost diagnostics of SARS-CoV-2 virus. Future developments are suggested regarding potential candidates in hospitals, clinics and laboratories for control and prevention of large-scale epidemic.

[ARDS Diagnostics and Treatment after the Coronavirus Pandemic - Everything as it was?]

ARDS is a syndrome that can develop as a result of various underlying diseases. For a long time, the prevailing belief was that the course of the disease was comparable regardless of the underlying disease. However, even before the COVID-19 pandemic, it was suspected that there were different manifestations that could be treated more individually and thus reduce the high mortality rate of ARDS, which has remained unchanged for years. The various findings on the heterogeneity of the course of the disease in COVID-related ARDS appear to confirm these assumptions. It is therefore to be expected that the diagnosis and treatment of non-COVID-related ARDS will also have to be individualised according to such phenotypes in the future. However, as long as the effectiveness of such strategies has not been proven in clinical trials, the current recommendations for ARDS therapy will remain valid for the time being. However, the adjustments already formulated in this context to individual pathophysiological conditions with regard to respiratory mechanics, ventilation-perfusion distribution and possible cardiac dysfunction should be made more meticulously than has usually been the case to date.

Early versus late tracheostomy in critically ill COVID-19 patients

BACKGROUND

The role of early tracheostomy as an intervention for critically ill COVID-19 patients is unclear. Previous reports have described prolonged intensive care stays and difficulty weaning from mechanical ventilation in critically ill COVID-19 patients, particularly in those developing acute respiratory distress syndrome. Pre-pandemic evidence on the benefits of early tracheostomy is conflicting but suggests shorter hospital stays and lower mortality rates compared to late tracheostomy.

OBJECTIVES

To assess the benefits and harms of early tracheostomy compared to late tracheostomy in critically ill COVID-19 patients.

SEARCH METHODS

We searched the Cochrane COVID-19 Study Register, which comprises CENTRAL, PubMed, Embase, ClinicalTrials.gov, WHO International Clinical Trials Registry Platform, and medRxiv, as well as Web of Science (Science Citation Index Expanded and Emerging Sources Citation Index) and WHO COVID-19 Global literature on coronavirus disease to identify completed and ongoing studies without language restrictions. We conducted the searches on 14 June 2022.

SELECTION CRITERIA

We followed standard Cochrane methodology. We included randomized controlled trials (RCTs) and non-randomized studies of interventions (NRSI) evaluating early tracheostomy compared to late tracheostomy during SARS-CoV-2 infection in critically ill adults irrespective of gender, ethnicity, or setting.

DATA COLLECTION AND ANALYSIS

We followed standard Cochrane methodology. To assess risk of bias in included studies, we used the Cochrane RoB 2 tool for RCTs and the ROBINS-I tool for NRSIs. We used the GRADE approach to assess the certainty of evidence for outcomes of our prioritized categories: mortality, clinical status, and intensive care unit (ICU) length of stay. As the timing of tracheostomy was very heterogeneous among the included studies, we applied GRADE only to studies that defined early tracheostomy as 10 days or less, which was chosen according to clinical relevance.

MAIN RESULTS

We included one RCT with 150 participants diagnosed with SARS-CoV-2 infection and 24 NRSIs with 6372 participants diagnosed with SARS-CoV-2 infection. All participants were admitted to the ICU, orally intubated and mechanically ventilated. The RCT was a multicenter, parallel, single-blinded study conducted in Sweden. Of the 24 NRSIs, which were mostly conducted in high- and middle-income countries, eight had a prospective design and 16 a retrospective design. We did not find any ongoing studies. RCT-based evidence We judged risk of bias for the RCT to be of low or some concerns regarding randomization and measurement of the outcome. Early tracheostomy may result in little to no difference in overall mortality (RR 0.82, 95% CI 0.52 to 1.29; RD 67 fewer per 1000, 95% CI 178 fewer to 108 more; 1 study, 150 participants; low-certainty evidence). As an indicator of improvement of clinical status, early tracheostomy may result in little to no difference in duration to liberation from invasive mechanical ventilation (MD 1.50 days fewer, 95%, CI 5.74 days fewer to 2.74 days more; 1 study, 150 participants; low-certainty evidence). As an indicator of worsening clinical status, early tracheostomy may result in little to no difference in the incidence of adverse events of any grade (RR 0.94, 95% CI 0.79 to 1.13; RD 47 fewer per 1000, 95% CI 164 fewer to 102 more; 1 study, 150 participants; low-certainty evidence); little to no difference in the incidence of ventilator-associated pneumonia (RR 1.08, 95% CI 0.23 to 5.20; RD 3 more per 1000, 95% CI 30 fewer to 162 more; 1 study, 150 participants; low-certainty evidence). None of the studies reported need for renal replacement therapy. Early tracheostomy may result in little benefit to no difference in ICU length of stay (MD 0.5 days fewer, 95% CI 5.34 days fewer to 4.34 days more; 1 study, 150 participants; low-certainty evidence). NRSI-based evidence We considered risk of bias for NRSIs to be critical because of possible confounding, study participant enrollment into the studies, intervention classification and potentially systematic errors in the measurement of outcomes. We are uncertain whether early tracheostomy (≤ 10 days) increases or decreases overall mortality (RR 1.47, 95% CI 0.43 to 5.00; RD 143 more per 1000, 95% CI 174 less to 1218 more; I2 = 79%; 2 studies, 719 participants) or duration to liberation from mechanical ventilation (MD 1.98 days fewer, 95% CI 0.16 days fewer to 4.12 more; 1 study, 50 participants), because we graded the certainty of evidence as very low. Three NRSIs reported ICU length of stay for 519 patients with early tracheostomy (≤ 10 days) as a median value, which we could not include in the meta-analyses. We are uncertain whether early tracheostomy (≤ 10 days) increases or decreases the ICU length of stay, because we graded the certainty of evidence as very low.

AUTHORS' CONCLUSIONS

We found low-certainty evidence that early tracheostomy may result in little to no difference in overall mortality in critically ill COVID-19 patients requiring prolonged mechanical ventilation compared with late tracheostomy. In terms of clinical improvement, early tracheostomy may result in little to no difference in duration to liberation from mechanical ventilation compared with late tracheostomy. We are not certain about the impact of early tracheostomy on clinical worsening in terms of the incidence of adverse events, need for renal replacement therapy, ventilator-associated pneumonia, or the length of stay in the ICU. Future RCTs should provide additional data on the benefits and harms of early tracheostomy for defined main outcomes of COVID-19 research, as well as of comparable diseases, especially for different population subgroups to reduce clinical heterogeneity, and report a longer observation period. Then it would be possible to draw conclusions regarding which patient groups might benefit from early intervention. Furthermore, validated scoring systems for more accurate predictions of the need for prolonged mechanical ventilation should be developed and used in new RCTs to ensure safer indication and patient safety. High-quality (prospectively registered) NRSIs should be conducted in the future to provide valuable answers to clinical questions. This could enable us to draw more reliable conclusions about the potential benefits and harms of early tracheostomy in critically ill COVID-19 patients.

Is Transplantation With Coronavirus Disease 2019-Positive Donor Lungs Safe? A US Nationwide Analysis

BACKGROUND

Since the beginning of the pandemic, coronavirus disease 2019 (COVID-19) has caused debilitating lung failure in many patients. Practitioners have understandably been hesitant to use lungs from donors with COVID-19 for transplantation. This study aimed to analyze the characteristics and short-term outcomes of lung transplantation from donors with recent positive COVID-19 testing results.

METHODS

Lung transplantations performed between January 2020 and June 2022 were queried from the United Network for Organ Sharing database. Pediatric, multiorgan, and repeat lung transplantations were excluded. Propensity scoring matched recipients of lungs from donors with recent positive COVID-19 testing results to recipients of lungs from donors with negative COVID-19 testing results, and comparisons of 30-day mortality, 3-month mortality, and perioperative outcomes were performed.

RESULTS

A total of 5270 patients underwent lung transplantation during the study dates, including 51 patients who received lungs from donors with recent positive COVID-19 testing results. Forty-five recipients of lungs from donors with recent positive COVID-19 testing results were matched with 135 recipients of lungs from donors with negative COVID-19 testing results. After matching, there was no difference in 30-day (log-rank P = .42) and 3-month (log-rank P = .42) mortality. The incidence of other perioperative complications was similar between the groups.

CONCLUSIONS

The 30-day and 3-month survival outcomes were similar between recipients of lungs from donors with recent positive COVID-19 testing results and recipients of lungs from donors with negative COVID-19 testing results. This finding suggests that highly selected COVID-19-positive donors without evidence of active infection may be safely considered for lung transplantation. Further studies should explore long-term outcomes to provide reassurance about the safety of this practice.

[Driving pressure-guided lung protective ventilation strategy reduces postoperative pulmonary complications in patients recovered from COVID-19]

OBJECTIVE

To investigate the value of lung protective ventilation strategy (LPVS) guided by driving pressure for preventing postoperative pulmonary complications (PPCs) in patients recovered from COVID-19 and optimize intraoperative respiratory management.

METHODS

From December, 2022 to February, 2023, a total of 118 patients recovered from COVID-19 within a month (ASA Ⅰ~Ⅲ, aged ≥18 years) undergoing elective non-cardiac surgeries under general anesthesia in our hospital were randomized equally into LPVS group and control group.The patients in LPVS group received a tidal volume of 6 mL/kg with an individualized PEEP guided by minimum driving pressure and lung re-expansion every 30 min, and those in the control group received conventional mechanical ventilation.The incidence of PPCs and hypoxemia and pulmonary ultrasound score of the patients were compared between the two groups.

RESULTS

There was no significant difference in the baseline data between LPVS group and the control group (P>0.05).Compared with the control group, LPVS group showed significantly lower incidences of PPCs (16.95%vs 35.59%, χ2=5.294, P=0.021) and hypoxemia (15.25%vs 30.51%, χ2=3.890, P=0.049) with also lower pulmonary ultrasound scores (5.31±1.07 vs 8.32±2.34, t=8.986, P<0.001).The PEEP value, airway pressure and plateau pressure in LPVS group were significantly higher, but the driving pressure and the tidal volume were lower than those in the control group (P<0.05).

CONCLUSION

LPVS guided by driving pressure can improve oxygenation and reduce the risk of PPCs in patients recently recovered from COVID-19.

Impact of COVID infection on lung function test and quality of life

Post-COVID-19 pulmonary sequalae are well-recognized early in the pandemic. Survivorship clinics are crucial for managing at-risk patients. However, it is unclear who requires pulmonary function test (PFT) and when PFTs should be performed. We aim to investigate for whom and how these interval PFTs should be performed. We performed a single-centre, prospective cohort study on COVID-19 survivors between 1st May 2020 and 31st April 2022. These patients were followed up at 6, 9 and 12 months with interval PFT and Short Form-36 (SF-36) Health Survey. Those with PFT defects were offered a computed tomography scan of the thorax. Of the 46 patients recruited, 17 (37%) had severe/critical illness. Compared to those with mild/moderate disease, these patients were more likely to experience DLCO defects (59% versus 17%, p = 0.005) and had lower SF-36 scores (mean physical component summary score of 45 ± 12 versus 52 ± 8, p = 0.046). These differences were most notable at 6 months, compared to the 9- and 12-months intervals. DLCO defects were also associated with older age, raised inflammatory markers and extensive CXR infiltrates. Besides interstitial-like abnormalities, obesity and undiagnosed lung conditions accounted for 39% of the PFT abnormalities. Interval PFTs can be performed earliest 6 months post-COVID-19. Patients with normal tests were unlikely to develop new abnormalities and would not require repeat PFTs. Abnormal PFTs can be followed-up with repeat PFTs 6 monthly until resolution. Non-COVID-19 differentials should be considered for persistent PFT abnormalities.

Exosomal MicroRNAs: An Emerging Important Regulator in Acute Lung Injury

Acute lung injury (ALI) is a clinically life-threatening form of respiratory failure with a mortality of 30%-40%. Acute respiratory distress syndrome is the aggravated form of ALI. Exosomes are extracellular lipid vesicles ubiquitous in human biofluids with a diameter of 30-150 nm. They can serve as carriers to convey their internal cargo, particularly microRNA (miRNA), to the target cells involved in cellular communication. In disease states, the quantities of exosomes and the cargo generated by cells are altered. These exosomes subsequently function as autocrine or paracrine signals to nearby or distant cells, regulating various pathogenic processes. Moreover, exosomal miRNAs from multiple stem cells can provide therapeutic value for ALI by regulating different signaling pathways. In addition, changes in exosomal miRNAs of biofluids can serve as biomarkers for the early diagnosis of ALI. This study aimed to review the role of exosomal miRNAs produced by different sources participating in various pathological processes of ALI and explore their potential significance in the treatment and diagnosis.

N-Acetylglucosamine mitigates lung injury and pulmonary fibrosis induced by bleomycin

Lung injury and pulmonary fibrosis contribute to morbidity and mortality, and, in particular, are characterized as leading cause on confirmed COVID-19 death. To date, efficient therapeutic approach for such lung diseases is lacking. N-Acetylglucosamine (NAG), an acetylated derivative of glucosamine, has been proposed as a potential protector of lung function in several types of lung diseases. The mechanism by which NAG protects against lung injury, however, remains unclear. Here, we show that NAG treatment improves pulmonary function in bleomycin (BLM)-induced lung injury model measured by flexiVent system. At early phase of lung injury, NAG treatment results in silenced immune response by targeting ARG1+ macrophages activation, and, consequently, blocks KRT8+ transitional stem cell in the alveolar region to stimulate PDGF Rβ+ fibroblasts hyperproliferation, thereby attenuating the pulmonary fibrosis. This combinational depression of immune response and extracellular matrix deposition within the lung mitigates lung injury and pulmonary fibrosis induced by BLM. Our findings provide novel insight into the protective role of NAG in lung injury.

Screening compounds for treating the diabetes and COVID-19 from Miao medicine by molecular docking and bioinformatics

Both diabetes and Corona Virus Disease 2019 (COVID-19) are seriously harmful to human health, and they are closely related. It is of great significance to find drugs that can simultaneously treat diabetes and COVID-19. Based on the theory of traditional Chinese medicine for treating COVID-19, this study first sorted out the compounds of Guizhou Miao medicine with "return to the lung channel" and "clear heat and detoxify" effects in China. The active components against COVID-19 were screened by molecular docking with SARS-CoV-2 PLpro and angiotensin-converting enzyme II as targets. Furthermore, the common target dipeptidyl peptidase 4 (DPP4) of diabetes and COVID-19 was used as a screening protein, and molecular docking was used to obtain potential components for the treatment of diabetes and COVID-19. Finally, the mechanism of potential ingredients in the treatment of diabetes and COVID-19 was explored with bioinformatics. More than 80 kinds of Miao medicine were obtained, and 584 compounds were obtained. Further, 110 compounds against COVID-19 were screened, and top 6 potential ingredients for the treatment of diabetes and COVID-19 were screened, including 3-O-β-D-Xylopyranosyl-(1-6)-β-D-glucopyranosyl-(1-6)-β-D-glucopyranosyl oleanolic acid 28-O-β-D-glucopyranosyl ester, Glycyrrhizic acid, Sequoiaflavone, 2-O-Caffeoyl maslinic acid, Pholidotin, and Ambewelamide A. Bioinformatics analysis found that their mechanism of action in treating diabetes and COVID-19 may be related to regulating the expression of DPP4, angiotensin II type 1 receptor, vitamin D receptor, plasminogen, chemokine C-C-motif receptor 6, and interleukin 2. We believe that Guizhou Miao medicine is rich in potential ingredients for the treatment of diabetes and COVID-19.

Ebselen and Diphenyl Diselenide Inhibit SARS-CoV-2 Replication at Non-Toxic Concentrations to Human Cell Lines

The novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) was the causative agent of the COVID-19 pandemic, a global public health problem. Despite the numerous studies for drug repurposing, there are only two FDA-approved antiviral agents (Remdesivir and Nirmatrelvir) for non-hospitalized patients with mild-to-moderate COVID-19 symptoms. Consequently, it is pivotal to search for new molecules with anti-SARS-CoV-2 activity and to study their effects in the human immune system. Ebselen (Eb) is an organoselenium compound that is safe for humans and has antioxidant, anti-inflammatory, and antimicrobial properties. Diphenyl diselenide ((PhSe)₂) shares several pharmacological properties with Eb and is of low toxicity to mammals. Herein, we investigated Eb and (PhSe)₂ anti-SARS-CoV-2 activity in a human pneumocytes cell model (Calu-3) and analyzed their toxic effects on human peripheral blood mononuclear cells (PBMCs). Both compounds significantly inhibited the SARS-CoV-2 replication in Calu-3 cells. The EC₅₀ values for Eb and (PhSe)₂ after 24 h post-infection (hpi) were 3.8 µM and 3.9 µM, respectively, and after 48 hpi were 2.6 µM and 3.4 µM. These concentrations are safe for non-infected cells, since the CC₅₀ values found for Eb and (PhSe)₂ on Calu-3 were greater than 200 µM. Importantly, the concentration rates tested on viral replication were not toxic to human PBMCs. Therefore, our findings reinforce the efficacy of Eb and demonstrate (PhSe)₂ as a new candidate to be tested in future trials against SARS-CoV-2 infection/inflammation conditions.

A novel galactoxylan derived from Viola diffusa alleviates LPS-induced acute lung injury via antagonizing P-selectin-mediated adhesion function

Acute lung injury (ALI) greatly threatens human health worldwide. P-selectin is a potential target for the treatment of acute inflammatory diseases, and natural polysaccharides exhibit high-affinity for P-selectin. Viola diffusa, a traditional Chinese herbal, shows strong anti-inflammatory effects, but pharmacodynamic substances and underlying mechanisms are still unclear. In this study, a galactoxylan polysaccharide (VDPS) derived from Viola diffusa was isolated and characterized, evaluated the protective effect on LPS induced ALI and underlying mechanism. VDPS significantly alleviated LPS-induced pathological lung injury, and decreased the numbers of total cells and neutrophils as well as the total protein contents in the bronchoalveolar lavage fluid (BALF). Moreover, VDPS reduced proinflammatory cytokine production both in BALF and lung. Interestingly, VDPS significantly restrained the activation of NF-κB signaling in the lung of LPS-exposed mice, but it cannot inhibit LPS-induced inflammation in human pulmonary microvascular endothelial cells (HPMECs) in vitro. Additionally, VDPS disrupted neutrophil adhesion and rolling on the activated HPMECs. VDPS cannot impact the expression or cytomembrane translocation of endothelial P-selectin, but remarkably interrupt the binding of P-selectin and PSGL-1. Overall, this study demonstrated that VDPS can alleviate LPS-induced ALI via inhibiting P-selectin-dependent adhesion and recruitment of neutrophils on the activated endothelium, providing a potential treatment strategy for ALI.

Esculin alleviates LPS-induced acute lung injury via inhibiting neutrophil recruitment and migration

OBJECTIVES

Acute lung injury (ALI) poses a serious threat to human health globally, particularly with the Coronavirus 2019 (COVID-19) pandemic. Excessive recruitment and infiltration of neutrophils is the major etiopathogenesis of ALI. Esculin, also known as 6,7-dihydroxycoumarin, is a remarkable compound derived from traditional Chinese medicine Cortex fraxini. Accumulated evidence indicates that esculin has potent anti-inflammatory effects, but its pharmaceutical effect against ALI and potential mechanisms are still unclear.

METHODS

This study evaluated the protective effect of esculin against ALI by histopathological observation and biochemical analysis of lung tissues and bronchoalveolar lavage fluid (BALF) in lipopolysaccharide (LPS)-challenged ALI mice in vivo. The effects of esculin on N-formyl-met-leu-phe (fMLP)-induced neutrophil migration and chemotaxis were quantitatively assessed using a Transwell assay and an automated cell imaging system equipped with a Zigmond chamber, respectively. The drug affinity responsive target stability (DARTS) assay, in vitro protein binding assay and molecular docking were performed to identify the potential therapeutic target of esculin and the potential binding sites and pattern.

RESULTS

Esculin significantly attenuated LPS-induced lung pathological injury, reduced the levels of pro-inflammatory cytokines in both BALF and lung, and suppressed the activation of NF-κB signaling. Esculin also significantly reduced the number of total cells and neutrophils as well as myeloperoxidase (MPO) activity in the BALF. Esculin impaired neutrophil migration and chemotaxis as evidenced by the reduced migration distance and velocity. Furthermore, esculin remarkably inhibited Vav1 phosphorylation, suppressed Rac1 activation and the PAK1/LIMK1/cofilin signaling axis. Mechanistically, esculin could interact with β₂ integrin and then diminish its ligand affinity with intercellular adhesion molecule-1 (ICAM-1).

CONCLUSIONS

Esculin inhibits β₂ integrin-dependent neutrophil migration and chemotaxis, blocks the cytoskeletal remodeling process required for neutrophil recruitment, thereby contributing to its protective effect against ALI. This study demonstrates the new therapeutic potential of esculin as a novel lead compound.

Targeting immunometabolism against acute lung injury

Acute lung injury (ALI) and acute respiratory distress syndrome (ARDS) are life-threatening conditions triggered by multiple intra- and extra-pulmonary injury factors, characterized by complicated molecular mechanisms and high mortality. Great strides have been made in the field of immunometabolism to clarify the interplay between intracellular metabolism and immune function in the past few years. Emerging evidence unveils the crucial roles of immunometabolism in inflammatory response and ALI. During ALI, both macrophages and lymphocytes undergo robust metabolic reprogramming and discrete epigenetic changes after activated. Apart from providing ATP and biosynthetic precursors, these metabolic cellular reactions and processes in lung also regulate inflammation and immunity.In fact, metabolic reprogramming involving glucose metabolism and fatty acidoxidation (FAO) acts as a double-edged sword in inflammatory response, which not only drives inflammasome activation but also elicits anti-inflammatory response. Additionally, the features and roles of metabolic reprogramming in different immune cells are not exactly the same. Here, we outline the evidence implicating how adverse factors shape immunometabolism in differentiation types of immune cells during ALI and summarize key proteins associated with energy expenditure and metabolic reprogramming. Finally, novel therapeutic targets in metabolic intermediates and enzymes together with current challenges in immunometabolism against ALI were discussed.

Missense Variants of von Willebrand Factor in the Background of COVID-19 Associated Coagulopathy

COVID-19 associated coagulopathy (CAC), characterized by endothelial dysfunction and hypercoagulability, evokes pulmonary immunothrombosis in advanced COVID-19 cases. Elevated von Willebrand factor (vWF) levels and reduced activities of the ADAMTS13 protease are common in CAC. Here, we aimed to determine whether common genetic variants of these proteins might be associated with COVID-19 severity and hemostatic parameters. A set of single nucleotide polymorphisms (SNPs) in the vWF (rs216311, rs216321, rs1063856, rs1800378, rs1800383) and ADAMTS13 genes (rs2301612, rs28729234, rs34024143) were genotyped in 72 COVID-19 patients. Cross-sectional cohort analysis revealed no association of any polymorphism with disease severity. On the other hand, analysis of variance (ANOVA) uncovered associations with the following clinical parameters: (1) the rs216311 T allele with enhanced INR (international normalized ratio); (2) the rs1800383 C allele with elevated fibrinogen levels; and (3) the rs1063856 C allele with increased red blood cell count, hemoglobin, and creatinine levels. No association could be observed between the phenotypic data and the polymorphisms in the ADAMTS13 gene. Importantly, in silico protein conformational analysis predicted that these missense variants would display global conformational alterations, which might affect the stability and plasma levels of vWF. Our results imply that missense vWF variants might modulate the thrombotic risk in COVID-19.

Angiotensin II increases respiratory rhythmic activity in the preBötzinger complex without inducing astroglial calcium signaling

Angiotensin II (Ang II) is the primary modulator of the renin-angiotensin system and has been widely studied for its effect on the cardiovascular system. While a few studies have also indicated an involvement of Ang II in the regulation of breathing, very little is known in this regard and its effect on brainstem respiratory regions such as the preBötzinger complex (preBötC), the kernel for inspiratory rhythm generation, has not been investigated yet. This study reports that Ang II temporarily increases phrenic nerve activity in the working heart-brainstem preparation, indicating higher central respiratory drive. Previous studies have shown that the carotid body is involved in mediating this effect and we revealed that the preBötC also plays a part, using acute slices of the brainstem. It appears that Ang II is increasing the respiratory drive in an AT1R-dependent manner by optimizing the interaction of inhibitory and excitatory neurons of the preBötC. Thus, Ang II-mediated effects on the preBötC are potentially involved in dysregulating breathing in patients with acute lung injury.

SARS-CoV-2 infection and multi-organ system damage: A review

The SARS-CoV-2 infection causes COVID-19, which has affected approximately six hundred million people globally as of August 2022. Organs and cells harboring angiotensin-converting enzyme 2 (ACE2) surface receptors are the primary targets of the virus. However, once it enters the body through the respiratory system, the virus can spread hematogenously to infect other body organs. Therefore, COVID-19 affects many organs, causing severe and long-term complications, even after the disease has ended, thus worsening the quality of life. Although it is known that the respiratory system is most affected by the SARS-CoV-2 infection, many organs/systems are affected in the short and long term. Since the COVID-19 disease simultaneously affects many organs, redesigning diagnostic and therapy policies to fit the damaged organs is strongly recommended. Even though the pathophysiology of many problems the infection causes is unknown, the frequency of COVID-19 cases rises with age and the existence of preexisting symptoms. This study aims to update our knowledge of SARS-CoV-2 infection and multi-organ dysfunction interaction based on clinical and theoretical evidence. For this purpose, the study comprehensively elucidates the most recent studies on the effects of SARS-CoV-2 infection on multiple organs and systems, including respiratory, cardiovascular, gastrointestinal, renal, nervous, endocrine, reproductive, immune, and parts of the integumentary system. Understanding the range of atypical COVID-19 symptoms could improve disease surveillance, limit transmission, and avoid additional multi-organ-system problems.

STV-Na attenuates lipopolysaccharide-induced lung injury in mice via the TLR4/NF-kB pathway

BACKGROUND

Acute lung injury (ALI) is a potentially fatal disorder that is largely caused by inflammation. Sodium isostevanol (STV-Na) is a terpenoid produced from stevioside, which possesses anti-inflammatory and antioxidative stress characteristics. nevertheless, it is still unclear how STV-Na affects ALI. Therefore, we investigated the possible STV-Na therapeutic impacts on lipopolysaccharide (LPS)-induced (ALI).

METHODS

We employed hematoxylin-eosin staining to observe the impact of STV-Na on lung histopathological alterations and used kits to detect the oxidative stress status of lung tissues, such as superoxide dismutase, malondialdehyde, and glutathione. The reactive oxygen species and myeloperoxidase expression in the tissues of lung was assessed by immunofluorescence and immunohistochemistry. Additionally, we detected the impact of STV-Na on inflammatory cell infiltration in lung tissue using Wright-Giemsa staining solution and immunohistochemistry, which was found to reduce inflammation in lung tissue by enzyme-linked immunosorbent assay. Finally, using WB, we examined the impact of STV-Na on the TLR4/NF-kB pathway.

RESULTS

We observed that STV-Na attenuated lung histopathological alterations in LPS-induced lung damage in mice, reduced infiltration of inflammatory cell and oxidative stress in the tissue of lung, and via the TLR4/NF-kB pathway, there is a reduction in the inflammatory responses in mouse lung tissue.

CONCLUSIONS

These outcomes indicate that the response of inflammatory cells to LPS-induced ALI in mice was attenuated by STV-Na.

A Counterintuitive Neutrophil-Mediated Pattern in COVID-19 Patients Revealed through Transcriptomics Analysis

The COVID-19 pandemic has persisted for almost three years. However, the mechanisms linked to the SARS-CoV-2 effect on tissues and disease severity have not been fully elucidated. Since the onset of the pandemic, a plethora of high-throughput data related to the host transcriptional response to SARS-CoV-2 infections has been generated. To this end, the aim of this study was to assess the effect of SARS-CoV-2 infections on circulating and organ tissue immune responses. We profited from the publicly accessible gene expression data of the blood and soft tissues by employing an integrated computational methodology, including bioinformatics, machine learning, and natural language processing in the relevant transcriptomics data. COVID-19 pathophysiology and severity have mainly been associated with macrophage-elicited responses and a characteristic "cytokine storm". Our counterintuitive findings suggested that the COVID-19 pathogenesis could also be mediated through neutrophil abundance and an exacerbated suppression of the immune system, leading eventually to uncontrolled viral dissemination and host cytotoxicity. The findings of this study elucidated new physiological functions of neutrophils, as well as tentative pathways to be explored in asymptomatic-, ethnicity- and locality-, or staging-associated studies.

Capnodynamic monitoring of lung volume and blood flow in response to increased positive end-expiratory pressure in moderate to severe COVID-19 pneumonia: an observational study

Background

The optimal level of positive end-expiratory pressure (PEEP) during mechanical ventilation for COVID-19 pneumonia remains debated and should ideally be guided by responses in both lung volume and perfusion. Capnodynamic monitoring allows both end-expiratory lung volume (\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${\text{EELV}}_{{{\text{CO}}_{2} }}$$\end{document}EELVCO2) and effective pulmonary blood flow (EPBF) to be determined at the bedside with ongoing ventilation.

Methods

Patients with COVID-19-related moderate to severe respiratory failure underwent capnodynamic monitoring of \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${\text{EELV}}_{{{\text{CO}}_{2} }}$$\end{document}EELVCO2 and EPBF during a step increase in PEEP by 50% above the baseline (PEEP_low to PEEP_high). The primary outcome was a > 20 mm Hg increase in arterial oxygen tension to inspired fraction of oxygen (P/F) ratio to define responders versus non-responders. Secondary outcomes included changes in physiological dead space and correlations with independently determined recruited lung volume and the recruitment-to-inflation ratio at an instantaneous, single breath decrease in PEEP. Mixed factor ANOVA for group mean differences and correlations by Pearson’s correlation coefficient are reported including their 95% confidence intervals.

Results

Of 27 patients studied, 15 responders increased the P/F ratio by 55 [24–86] mm Hg compared to 12 non-responders (p < 0.01) as PEEP_low (11 ± 2.7 cm H₂O) was increased to PEEP_high (18 ± 3.0 cm H₂O). The \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${\text{EELV}}_{{{\text{CO}}_{2} }}$$\end{document}EELVCO2 was 461 [82–839] ml less in responders at PEEP_low (p = 0.02) but not statistically different between groups at PEEP_high. Responders increased both \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${\text{EELV}}_{{{\text{CO}}_{2} }}$$\end{document}EELVCO2 and EPBF at PEEP_high (r = 0.56 [0.18–0.83], p = 0.03). In contrast, non-responders demonstrated a negative correlation (r = − 0.65 [− 0.12 to − 0.89], p = 0.02) with increased lung volume associated with decreased pulmonary perfusion. Decreased (− 0.06 [− 0.02 to − 0.09] %, p < 0.01) dead space was observed in responders. The change in \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${\text{EELV}}_{{{\text{CO}}_{2} }}$$\end{document}EELVCO2 correlated with both the recruited lung volume (r = 0.85 [0.69–0.93], p < 0.01) and the recruitment-to-inflation ratio (r = 0.87 [0.74–0.94], p < 0.01).

Conclusions

In mechanically ventilated patients with moderate to severe COVID-19 respiratory failure, improved oxygenation in response to increased PEEP was associated with increased end-expiratory lung volume and pulmonary perfusion. The change in end-expiratory lung volume was positively correlated with the lung volume recruited and the recruitment-to-inflation ratio. This study demonstrates the feasibility of capnodynamic monitoring to assess physiological responses to PEEP at the bedside to facilitate an individualised setting of PEEP.

Trial registration: NCT05082168 (18th October 2021).

Supplementary Information

The online version contains supplementary material available at 10.1186/s13054-022-04110-0.

Targeting the Complement-Sphingolipid System in COVID-19 and Gaucher Diseases: Evidence for a New Treatment Strategy

Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2)-induced disease (COVID-19) and Gaucher disease (GD) exhibit upregulation of complement 5a (C5a) and its C5aR1 receptor, and excess synthesis of glycosphingolipids that lead to increased infiltration and activation of innate and adaptive immune cells, resulting in massive generation of pro-inflammatory cytokines, chemokines and growth factors. This C5a-C5aR1-glycosphingolipid pathway- induced pro-inflammatory environment causes the tissue damage in COVID-19 and GD. Strikingly, pharmaceutically targeting the C5a-C5aR1 axis or the glycosphingolipid synthesis pathway led to a reduction in glycosphingolipid synthesis and innate and adaptive immune inflammation, and protection from the tissue destruction in both COVID-19 and GD. These results reveal a common involvement of the complement and glycosphingolipid systems driving immune inflammation and tissue damage in COVID-19 and GD, respectively. It is therefore expected that combined targeting of the complement and sphingolipid pathways could ameliorate the tissue destruction, organ failure, and death in patients at high-risk of developing severe cases of COVID-19.

Inducible general knockout of Runx3 profoundly reduces pulmonary cytotoxic CD8+ T cells with minimal effect on outcomes in mice following influenza infection

Respiratory viruses pose a continuing and substantive threat to human health globally. Host innate and adaptive immune responses are the critical antiviral defense mechanisms to control viral replication and spread. The present study is designed to determine the role of transcription factor Runx3 in the host immune response to influenza A virus (IAV) infection. As Runx3 is required for embryonic development, we generated an inducible Runx3 global knockout (KO) mouse model and found that Runx3 KO in adult C57BL/6 mice minimally affected thymic function under normal conditions and survival was at least 250 days post Runx3 deletion. We applied the mouse model to IAV infection and found that Runx3 KO resulted in a huge reduction (>85%) in numbers of total and antigen-specific pulmonary CD8⁺ cytotoxic T cells during IAV infection, while it had a minor effect on pulmonary generation of CD4⁺ T cells. To our surprise, this general KO of Runx3 did not significantly alter viral clearance and animal survival following IAV infection. Interestingly, we found that Runx3 KO significantly increased the numbers of pulmonary innate immune cells such as macrophages and neutrophils and the production of pro-inflammatory cytokines during IAV infection. We further found that Runx3 was strongly detected in CCR2⁺ immune cells in IAV-infected mouse lungs and was induced in activated macrophages and dendritic cells (DCs). As pulmonary CD8⁺ cytotoxic T cells play a central role in the clearance of IAV, our findings suggest that Runx3 KO may enhance host innate immunity to compensate for the loss of pulmonary CD8⁺ cytotoxic T cells during IAV infection.

Smart face shield for the monitoring of COVID-19 physiological parameters: Personal protective equipment (PPE) for health-care workers (HCW’s) and COVID-19 patients

The COVID-19 pandemic has triggered instabilities in various aspects of daily life. This includes economic, social, financial, and health crisis. In addition, the COVID-19 pandemic with the evolution of different virus strains such as delta and omicron has led to frequent global lockdowns. These lockdowns have caused disruption of trade activities that in turn have led to the shortage of medical supplies, especially personal protective equipment’s (PPE’s). Health-care workers (HCW’s) have been at the forefront of the fight against this pandemic and are responsible for saving millions of lives worldwide. However, the PPE’s available to HCW’s in the form of face shields and face masks only provide face and eye protection without encapsulating the ability to continuously monitor vital COVID-19 parameters including body temperature, heart rate, and SpO2. Hence, in this study, we propose the design and utilization of a PPE in the form of smart face shield. The device has been integrated with the MAX30102 sensor for measuring the heart rate and oxygen saturation (SpO2) and the DS18B20 body temperature measuring sensor. The readings of these sensors are analyzed by a NodeMCU ESP8266 and measurements are displayed on a laptop screen. Also, the Wi-Fi module of NodeMCU ESP8266 enables compatibility with the ThingSpeak mobile application and permits HCW’s and patients recovering from COVID-19 to keep a track of their physiological parameters. Overall, this PPE has been observed to provide reliable readings and the results indicate that the designed prototype can be used for monitoring COVID-19 essential parameters.

Decrease in Angiotensin-Converting Enzyme activity but not concentration in plasma/lungs in COVID-19 patients offers clues for diagnosis/treatment

Although several therapeutics are used to treat coronavirus disease 2019 (COVID-19) patients, there is still no definitive metabolic marker to evaluate disease severity and recovery or a quantitative test to end quarantine. Because severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infects human cells via the angiotensin-converting-enzyme 2 (ACE2) receptor and COVID-19 is associated with renin-angiotensin system dysregulation, we evaluated soluble ACE2 (sACE2) activity in the plasma/saliva of 80 hospitalized COVID-19 patients and 27 non-COVID-19 volunteers, and levels of ACE2/Ang (1-7) in plasma or membrane (mACE2) in lung autopsy samples. sACE2 activity was markedly reduced (p < 0.0001) in COVID-19 plasma (n = 59) compared with controls (n = 27). Nadir sACE2 activity in early hospitalization was restored during disease recovery, irrespective of patient age, demographic variations, or comorbidity; in convalescent plasma-administered patients (n = 45), restoration was statistically higher than matched controls (n = 22, p = 0.0021). ACE2 activity was also substantially reduced in the saliva of COVID-19 patients compared with controls (p = 0.0065). There is a strong inverse correlation between sACE2 concentration and sACE2 activity and Ang (1-7) levels in participant plasmas. However, there were no difference in membrane ACE2 levels in lungs of autopsy tissues of COVID-19 (n = 800) versus other conditions (n = 300). These clinical observations suggest sACE2 activity as a potential biomarker and therapeutic target for COVID-19.

SARS-CoV-2 and COVID-19: A Narrative Review

The World Health Organisation has reported that the viral disease known as COVID-19, caused by SARS-CoV-2, is the leading cause of death by a single infectious agent. This narrative review examines certain components of the pandemic: its origins, early clinical data, global and UK-focussed epidemiology, vaccination, variants, and long COVID.

Silent Hypoxemia in the Emergency Department: A Retrospective Cohort of Two Clinical Phenotypes in Critical COVID-19

Introduction: Understanding hypoxemia, with and without the clinical signs of acute respiratory failure (ARF) in COVID-19, is key for management. Hence, from a population of critical patients admitted to the emergency department (ED), we aimed to study silent hypoxemia (Phenotype I) in comparison to symptomatic hypoxemia with clinical signs of ARF (Phenotype II). Methods: This multicenter study was conducted between 1 March and 30 April 2020. Adult patients who were presented to the EDs of nine Great-Eastern French hospitals for confirmed severe or critical COVID-19, who were then directly admitted to the intensive care unit (ICU), were retrospectively included. Results: A total of 423 critical COVID-19 patients were included, out of whom 56.1% presented symptomatic hypoxemia with clinical signs of ARF, whereas 43.9% presented silent hypoxemia. Patients with clinical phenotype II were primarily intubated, initially, in the ED (46%, p < 0.001), whereas those with silent hypoxemia (56.5%, p < 0.001) were primarily intubated in the ICU. Initial univariate analysis revealed higher ICU mortality (29.2% versus 18.8%, p < 0.014) and in-hospital mortality (32.5% versus 18.8%, p < 0.002) in phenotype II. However, multivariate analysis showed no significant differences between the two phenotypes regarding mortality and hospital or ICU length of stay. Conclusions: Silent hypoxemia is explained by various mechanisms, most physiological and unspecific to COVID-19. Survival was found to be comparable in both phenotypes, with decreased survival in favor of Phenotype II. However, the spectrum of silent to symptomatic hypoxemia appears to include a continuum of disease progression, which can brutally evolve into fatal ARF.

Aurantiamide Acetate Ameliorates Lung Inflammation in Lipopolysaccharide-Induced Acute Lung Injury in Mice

Purpose

Aurantiamide acetate (AA) is a dipeptide derivative with complex pharmacological activities and remarkable effects on preventing and treating various diseases. In the current study, we aimed to investigate whether AA can exert protective effects in a mouse model of ALI induced by LPS.

Materials and Methods

In this model, mice were given intranasal LPS for 3 days prior to receiving AA (2.5, 5, and 10 mg/kg) via oral gavage. An assessment of histopathological changes was performed by hematoxylin and eosin (HE). Proinflammatory cytokines were detected in bronchoalveolar lavage fluids (BALFs) by enzyme-linked immunosorbent assays (ELISAs). The effects of AA on protein expression of NF-κB and PI3K/AKT signaling pathways were determined by Western blot. In addition, lung wet/dry (W/D) weight ratio, myeloperoxidase (MPO) activity, cell counts, and protein content were also measured.

Results

According to results, AA pretreatment significantly reduced lung pathological changes, W/D ratio, MPO activity, and protein content. Additionally, AA resulted in a significant reduction in the number of total cells, neutrophils, and proinflammatory cytokines in the BALF after LPS stimulation. The subsequent study revealed that pretreatment with AA dose dependently suppressed LPS-induced activation of NF-κB as well as PI3K/AKT phosphorylation.

Conclusion

The results indicated that the AA had a protective effect on LPS-induced ALI in mice and could be a potential drug for ALI.

Diagnosis and management of covid-19 in pregnancy

Pregnant women with covid-19 are at greater risk of severe disease than their non-pregnant peers, and yet they are frequently denied investigations or treatments because of unfounded concerns about risk to the fetus. The basic principles of diagnosing and managing covid-19 are the same as for non-pregnant patients, and a multidisciplinary, expert team approach is essential to ensure optimal care. During pregnancy, treatment with corticosteroids should be modified to use non-fluorinated glucocorticoids. Il-6 inhibitors and monoclonal antibodies, together with specific antiviral therapies, may also be considered. Prophylaxis against venous thromboembolism is important. Women may require respiratory support with oxygen, non-invasive ventilation, ventilation in a prone position (either awake or during invasive ventilation), intubation and ventilation, and extracorporeal membrane oxygenation (ECMO). Pregnancy is not a contraindication for any of these supportive therapies, and the criteria for providing them are the same as in the general population. Decisions regarding timing, place, and mode of delivery should be taken with a multidisciplinary team including obstetricians, physicians, anesthetists, and intensivists experienced in the care of covid-19 in pregnancy. Ideally these decisions should take place in consultation with centers that have experience and expertise in all these specialties.

Interferon-γ Preferentially Promotes Necroptosis of Lung Epithelial Cells by Upregulating MLKL

Necroptosis, a form of programmed lytic cell death, has emerged as a driving factor in the pathogenesis of acute lung injury (ALI). As ALI is often associated with a cytokine storm, we determined whether pro-inflammatory cytokines modulate the susceptibility of lung cells to necroptosis and which mediators dominate to control necroptosis. In this study, we pretreated/primed mouse primary lung epithelial and endothelial cells with various inflammatory mediators and assessed cell type-dependent responses to different necroptosis inducers and their underlying mechanisms. We found that interferon-γ (IFNγ) as low as 1 ng/mL preferentially promoted necroptosis and accelerated the release of damage-associated molecular patterns from primary alveolar and airway epithelial cells but not lung microvascular endothelial cells. Type-I IFNα was about fifty-fold less effective than IFNγ. Conversely, TNFα or agonists of Toll-like receptor-3 (TLR3), TLR4, TLR7 and TLR9 had a minor effect. The enhanced necroptosis in IFNγ-activated lung epithelial cells was dependent on IFNγ signaling and receptor-interacting protein kinase-3. We further showed that necroptosis effector mixed lineage kinase domain-like protein (MLKL) was predominantly induced by IFNγ, contributing to the enhanced necroptosis in lung epithelial cells. Collectively, our findings indicate that IFNγ is a potent enhancer of lung epithelial cell susceptibility to necroptosis.

Pulmonary delivery of curcumin-loaded glycyrrhizic acid nanoparticles for anti-inflammatory therapy

Curcumin was loaded into the glycyrrhizic acid nanoparticles and delivered into the lungs for the treatment of acute lung injury.