COVID-19: Invasion, pathogenesis and possible cure - A review

An Overview of Pediatric Pulmonary Complications During COVID-19 Pandemic: A Lesson for Future

BACKGROUND

The pediatric community is considered a suitable target for controlling the spread and mortality of viral diseases. In late December 2019, a respiratory disease due to the novel coronavirus, later COVID-19, hit the globe. The COVID-19 global disruption had direct and indirect impacts on different aspects of child health. Therefore, surveillance, preventive approaches, and treatment plans for children came into the spotlight.

OBJECTIVE

This study aims to discuss the clinical pictures as well as laboratory and radiological findings of the infected children during the COVID-19 pandemic. The focus of this study is to express the clinical manifestations of respiratory disease in pediatric SARS-CoV-2, available therapeutic options, vaccine recommendations, and long COVID sequelae in affected children. This review could serve as a hint for upcoming challenges in pediatric care during future pandemics.

RESULTS

The clinical presentation of COVID-19 in pediatrics can range from mild pulmonary disease to acute respiratory distress syndrome (ARDS). Supportive care is a crucial component of the management of pediatric COVID-19. However, the importance of specializing in how to treat patients with more severe conditions cannot be overstated. Additionally, clinicians must consider prevention strategies as well as potential complications.

CONCLUSION

Although the infected patients are dipping day by day, there is a lack of clinical guidelines for pediatric SARS-CoV-2-associated pulmonary diseases. Understanding of the physicians about all aspects of pediatric care during the COVID-19 pandemic could lead to enhanced quality of future patient care and safety, reduced costs of health policies, and surveil the risk that patients with respiratory viruses can expose to society.

Use of high-resolution fluorescence in situ hybridization for fast and robust detection of SARS-CoV-2 RNAs

Early, rapid, and accurate diagnostic tests play critical roles not only in the identification/management of individuals infected by SARS-CoV-2, but also in fast and effective public health surveillance, containment, and response. Our aim has been to develop a fast and robust fluorescence in situ hybridization (FISH) detection method for detecting SARS-CoV-2 RNAs by using an HEK 293 T cell culture model. At various times after being transfected with SARS-CoV-2 E and N plasmids, HEK 293 T cells were fixed and then hybridized with ATTO-labeled short DNA probes (about 20 nt). At 4 h, 12 h, and 24 h after transfection, SARS-CoV-2 E and N mRNAs were clearly revealed as solid granular staining inside HEK 293 T cells at all time points. Hybridization time was also reduced to 1 h for faster detection, and the test was completed within 3 h with excellent results. In addition, we have successfully detected 3 mRNAs (E mRNA, N mRNA, and ORF1a (-) RNA) simultaneously inside the buccal cells of COVID-19 patients. Our high-resolution RNA FISH might significantly increase the accuracy and efficiency of SARS-CoV-2 detection, while significantly reducing test time. The method can be conducted on smears containing cells (e.g., from nasopharyngeal, oropharyngeal, or buccal swabs) or smears without cells (e.g., from sputum, saliva, or drinking water/wastewater) for detecting various types of RNA viruses and even DNA viruses at different timepoints of infection.

Pathogenesis of COVID19 and the applications of US FDA-approved repurposed antiviral drugs to combat SARS-CoV-2 in Saudi Arabia: A recent update by review of literature

Still, there is no cure for the highly contagious severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-caused coronavirus disease 2019 (COVID19). The COVID19 pandemic caused health emergencies which resulted in enormous medical and financial consequences worldwide including Saudi Arabia. Saudi Arabia is the largest Arab country of the Middle East. The urban setting of Saudi Arabia makes it vulnerable towards SARS-CoV-2 (SCV-2). Religious areas of this country are visited by millions of pilgrims every year for the Umrah and Hajj pilgrimage, which contributes to the potential COVID19 epidemic risk. COVID19 throws various challenges to healthcare professionals to choose the right drugs or therapy in clinical settings because of the lack of availability of newer drugs. Current drug development and discovery is an expensive, complex, and long process, which involves a high failure rate in clinical trials. While repurposing of United States Food and Drug Administration (US FDA)-approved antiviral drugs offers numerous benefits including complete pharmacokinetic and safety profiles, which significantly shorten drug development cycles and reduce costs. A range of repurposed US FDA-approved antiviral drugs including ribavirin, lopinavir/ritonavir combination, oseltamivir, darunavir, remdesivir, nirmatrelvir/ritonavir combination, and molnupiravir showed encouraging results in clinical trials in COVID19 treatment. In this article, several COVID19-related discussions have been provided including emerging variants of concern of, COVID19 pathogenesis, COVID19 pandemic scenario in Saudi Arabia, drug repurposing strategies against SCV-2, as well as repurposing of US FDA-approved antiviral drugs that might be considered to combat SCV-2 in Saudi Arabia. Moreover, drug repurposing in the context of COVID19 management along with its limitations and future perspectives have been summarized.

The efficacy and safety of ginger (Zingiber officinale) rhizome extract in outpatients with COVID-19: A randomized double-blind placebo-control clinical trial

BACKGROUND

Ginger, a potent antiviral, anti-inflammatory, and antioxidant remedy, is a potential therapeutic option for COVID-19. However, there was not enough clinical evidence about ginger and COVID-19. We evaluated the efficacy and safety of ginger on clinical and paraclinical features in outpatients with COVID-19.

METHODS

In this randomized controlled trial, the outpatients with confirmed COVID-19 were randomly assigned in a 1:1 ratio to receive ginger (1000 mg 3 times a day for 7 days) or placebo. The primary outcome was viral clearance after the end of the intervention. Oxygen saturation (SPO2), body temperature, respiratory rate (RR), hospital admission, and the incidence of adverse events were also assessed.

RESULTS

A total of 84 patients (42 in the ginger and 42 in the control groups) were randomized. The viral clearance was not statistically improved in the ginger group (41.6%) compared to the placebo group (42.8%). The findings indicated that SPO2, body temperature, and RR had no significant difference between the groups at the end of the intervention. The imaging finding indicated pulmonary infiltrate significantly reduced on the 7th day of the intervention in the ginger group. The percentage of patients with SPO2 <96% in the ginger group decreased over the study compared to the placebo group. Moreover, the need for hospital admission and the incidence of adverse drug events were not different between the groups over the follow-up period.

CONCLUSIONS

Ginger had no significant impact on the clinical and paraclinical parameters of patients. However, this intervention demonstrated a safe profile of adverse events and reduced pulmonary infiltrate.

TRIAL REGISTRATION

The trial was registered as IRCT20200506047323N1.

Domestic firearm violence against women (2018-2021)

Background

Over 50 % of US female homicides occur during domestic violence, with half involving firearms. Public health measures to control COVID-19 may have isolated individuals with abusive partners at a time when firearm sales and new firearm ownership surged. This study sought to evaluate trends in domestic firearm violence (DFV) over time, hypothesizing that rates of DFV increased in the wake of COVID-19.

Materials and methods

A retrospective query of the Gun Violence Archive (2018-2021) was conducted for incidents of DFV. The primary outcome was the number of DFV-related shootings. Statistical testing, including one-way and two-way ANOVAs, was performed to compare monthly rates of DFV over time and to compare DFV per 100,000 women in states with strong versus weak gun laws.

Results

Average monthly DFV incidents rose nationwide during this study's time period, though injuries and fatalities did not. States with weaker gun laws had increased incidents, deaths, and injuries from 2018 to 2021 (all p<0.05). In a two-way ANOVA, stronger gun laws were associated with fewer incidents of DFV when compared with weaker gun law states. We also found that the use of a long gun in DFV more often resulted in a victim's death when compared to a handgun (p<0.01).

Conclusion

DFV incidents increased over time. States with weaker gun laws bore the brunt of the violence, demonstrating that DFV may be curtailed through legislative efforts. Methods of injury prevention aimed at preventing and reducing domestic violence and improving firearm safety may curtail DFV.

Oral microbiota study of the patients after hospitalisation for COVID-19, considering selected dental indices and antibiotic therapy using the next generation sequencing method (NGS)

Background

Poor oral hygiene and the increased incidence and severity of periodontitis may exacerbate SARS-CoV-2 infection. The aim was to evaluate the oral microbiota of 60 participants divided into groups: COVID-19 convalescents who received antibiotics during hospitalization (I), COVID-19 convalescents without antibiotic therapy (II) and healthy individuals (III).

Materials and Methods

Dental examination was conducted, and oral health status was evaluated using selected dental indexes. Clinical samples (saliva, dorsal swabs, supragingival and subgingival plaque) were collected and used for metagenomic library to the next-generation sequencing (NGS) preparation.

Results

Each of the clinical materials in particular groups of patients showed a statistically significant and quantitatively different bacterial composition. Patients from group I showed significantly worse oral health, reflected by higher average values of dental indexes and also a higher percentage of Veillonella, Tannerella, Capnocytophaga and Selenomonas genera in comparison to other groups. Additionally, a statistically significant decrease in the amount of Akkermansia type in both groups with COVID-19 was observed for all materials.

Conclusions

The primary factor affecting the composition of oral microbiota was not the SARS-CoV-2 infection itself, but the use of antibiotic therapy. The increased percentage of pro-inflammatory pathogens observed in COVID-19 patients underscores the importance of preventing periodontal disease and improving oral hygiene in the future.

Mesenchymal Stem Cells in the Treatment of COVID-19

Since the emergence of the coronavirus disease 2019 (COVID-19) pandemic, many lives have been tragically lost to severe infections. The COVID-19 impact extends beyond the respiratory system, affecting various organs and functions. In severe cases, it can progress to acute respiratory distress syndrome (ARDS) and multi-organ failure, often fueled by an excessive immune response known as a cytokine storm. Mesenchymal stem cells (MSCs) have considerable potential because they can mitigate inflammation, modulate immune responses, and promote tissue regeneration. Accumulating evidence underscores the efficacy and safety of MSCs in treating severe COVID-19 and ARDS. Nonetheless, critical aspects, such as optimal routes of MSC administration, appropriate dosage, treatment intervals, management of extrapulmonary complications, and potential pediatric applications, warrant further exploration. These research avenues hold promise for enriching our understanding and refining the application of MSCs in confronting the multifaceted challenges posed by COVID-19.

Rapid Virucidal Activity of Japanese Saxifraga Species-Derived Condensed Tannins against SARS-CoV-2, Influenza A Virus, and Human Norovirus Surrogate Viruses

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), influenza A virus (IAV), and norovirus are global threats to human health. The application of effective virucidal agents, which contribute to the inactivation of viruses on hands and environmental surfaces, is important to facilitate robust virus infection control measures. Naturally derived virucidal disinfectants have attracted attention owing to their safety and eco-friendly properties. In this study, we showed that multiple Japanese Saxifraga species-derived fractions demonstrated rapid, potent virucidal activity against the SARS-CoV-2 ancestral strain and multiple variant strains, IAV, and two human norovirus surrogates: feline calicivirus (FCV) and murine norovirus (MNV). Condensed tannins were identified as active chemical constituents that play a central role in the virucidal activities of these fractions. At a concentration of 25 μg/mL, the purified condensed tannin fraction Sst-2R induced significant reductions in the viral titers of the SARS-CoV-2 ancestral strain, IAV, and FCV (reductions of ≥3.13, ≥3.00, and 2.50 log₁₀ 50% tissue culture infective doses [TCID₅₀]/mL, respectively) within 10 s of reaction time. Furthermore, at a concentration of 100 μg/mL, Sst-2R induced a reduction of 1.75 log₁₀ TCID₅₀/mL in the viral titers of MNV within 1 min. Western blotting and transmission electron microscopy analyses revealed that Sst-2R produced structural abnormalities in viral structural proteins and envelopes, resulting in the destruction of viral particles. Furthermore, Saxifraga species-derived fraction-containing cream showed virucidal activity against multiple viruses within 10 min. Our findings indicate that Saxifraga species-derived fractions containing condensed tannins can be used as disinfectants against multiple viruses on hands and environmental surfaces. IMPORTANCE SARS-CoV-2, IAV, and norovirus are highly contagious pathogens. The use of naturally derived components as novel virucidal/antiviral agents is currently attracting attention. We showed that fractions from extracts of Saxifraga species, in the form of a solution as well as a cream, exerted potent, rapid virucidal activities against SARS-CoV-2, IAV, and surrogates of human norovirus. Condensed tannins were found to play a central role in this activity. The in vitro cytotoxicity of the purified condensed tannin fraction at a concentration that exhibited some extent of virucidal activity was lower than that of 70% ethanol or 2,000 ppm sodium hypochlorite solution, which are popular virucidal disinfectants. Our study suggests that Saxifraga species-derived fractions containing condensed tannins can be used on hands and environmental surfaces as safe virucidal agents against multiple viruses.

Safety, Biodistribution, and Dosimetry Study of Meplazumab, a Potential COVID-19 Therapeutic Drug, with 131I-Labeling and SPECT Imaging

Coronavirus disease 2019 (COVID-19) is a serious threat to public health and is in urgent need of specific drugs. Meplazumab, a humanized monoclonal antibody targeting CD147, was confirmed to competitively block the binding between the spike of syndrome coronavirus 2 (SARS-CoV-2) and CD147, making meplazumab a promising candidate drug for COVID-19. In this study, biodistribution and dosimetry of 131I-labeled meplazumab were performed to further evaluate its potential as a therapeutic drug for COVID-19. 131I-meplazumab was both safe and tolerant in mice and healthy volunteers. A biodistribution study was performed in normal mice, and blood samples were used for pharmacokinetic analysis. Three healthy volunteers were included and subjected to single-photon-emission computed tomography (SPECT) imaging of 131I-meplazumab within 2 weeks. The distribution in mice and humans was consistent with the in vivo distribution of CD147. Biodistribution and SPECT imaging results exhibited that the liver was the organ with the highest uptake for both mice and humans. Deiodination of 131I-meplazumab can be observed in vivo, and taking Lugol's solution can protect the thyroid gland effectively. The pharmacokinetic characteristics of 131I-meplazumab in mice and humans best fit the two-compartment model. The clearance half-life (T1/2β) in mice and humans was 117.4 and 223.5 h, respectively. The results indicated that its pharmacokinetic properties in vivo were ideal. The effective dose calculated from healthy volunteers was 0.811 ± 0.260 mSv·MBq-1, which was twice the value calculated from mice. It was safe and feasible to perform human clinical imaging experiments using a diagnostic dose of 131I-meplazumab after thyroid closure by Lugol's solution. This study will provide more experimental basis for advancing the clinical translation of meplazumab and will be valuable in evaluating therapeutic interventions for patients with COVID-19, as well as providing a reference for clinical translation studies of other antibody drugs.

Gas6/TAM Axis Involvement in Modulating Inflammation and Fibrosis in COVID-19 Patients

Gas6 (growth arrest-specific gene 6) is a widely expressed vitamin K-dependent protein that is involved in many biological processes such as homeostatic regulation, inflammation and repair/fibrotic processes. It is known that it is the main ligand of TAMs, a tyrosine kinase receptor family of three members, namely MerTK, Tyro-3 and Axl, for which it displays the highest affinity. Gas6/TAM axis activation is known to be involved in modulating inflammatory responses as well as fibrotic evolution in many different pathological conditions. Due to the rapidly evolving COVID-19 pandemic, this review will focus on Gas6/TAM axis activation in SARS-CoV-2 infection, where de-regulated inflammatory responses and fibrosis represent a relevant feature of severe disease manifestation. Furthermore, this review will highlight the most recent scientific evidence supporting an unsuspected role of Axl as a SARS-CoV-2 infection driver, and the potential therapeutic advantages of the use of existing Axl inhibitors in COVID-19 management. From a physiological point of view, the Gas6/TAM axis plays a dual role, fostering the tissue repair processes or leading to organ damage and loss of function, depending on the prevalence of its anti-inflammatory or profibrotic properties. This review makes a strong case for further research focusing on the Gas6/TAM axis as a pharmacological target to manage different disease conditions, such as chronic fibrosis or COVID-19.

The Rationale for Using Corticosteroids in COVID-19 Encephalopathy: Lessons From a Case Report With Evidence From Literature

The coronavirus disease 2019 (COVID-19) virus primarily affects the pulmonary system, but neurological manifestations and complication of COVID-19 has been reported in abundance in the literature. We present a case of a middle-aged Caucasian male who was brought to the emergency department for altered mental status. His chief complaints were neurological rather than respiratory. A positive severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) reverse transcription polymerase chain reaction (RT-PCR) nasal swab confirmed the diagnosis. Brain imaging showed mildly dilated ventricles with no other acute findings. As the patient did not require oxygen, he was treated with remdesivir alone without corticosteroids, which is also a precipitating factor of psychosis but, unfortunately, thickly used in practice. That led to remarkable results in full recovery without exposing the patient to steroid therapy. We strongly believe that remdesivir alone is sufficient in treating COVID-19-induced encephalopathy in a patient who does not require oxygen, and evidence supports this practice.

Investigating the correlation between COVID-19 and the progression of chronic liver disease

INTRODUCTION

The novel coronavirus disease 2019 has thrown light on various heterogeneous afflictions of newly emerging viruses on the human body. Early reports demonstrated direct effect of novel coronavirus on the liver, but subsequently, this did not stand up to validation. The SARS-CoV-2 virus affects the liver differentially; in healthy compared to those with preexisting liver disease.

AREAS COVERED

This exhaustive paper reviews the current, literature on mechanisms by which COVID-19 affects the healthy liver and those with preexisting liver disease such as alcohol-related and nonalcoholic fatty liver, autoimmune liver disease, chronic liver disease and cirrhosis, hepatocellular carcinoma, viral hepatitis, and liver transplant recipients, with special mention on drug-and herb-induced liver injury with COVID-19 therapies. Search methodology: the review (Dec. 2022 - Jan. 2023) is based on PubMed (NLM) search using the keyword 'COVID' with supplementary searches using 'fibrosis;' 'liver;' 'cirrhosis;' 'CLD;' 'NAFLD;' 'NASH;' 'hepatocellular carcinoma;' 'hepatitis;' 'fatty liver;' 'alcohol;' 'viral;' 'transplant;' and 'liver failure.'

EXPERT OPINION

Direct liver tropism of SARS-CoV-2 does not cause liver damage. Adverse events following infection depend on the severity of liver disease, the severity of COVID-19, and other risk factors such as metabolic syndrome and older age. Alcohol-related liver disease independently predicts adverse outcomes.

Can Lactoferrin, a Natural Mammalian Milk Protein, Assist in the Battle against COVID-19?

Notwithstanding mass vaccination against specific SARS-CoV-2 variants, there is still a demand for complementary nutritional intervention strategies to fight COVID-19. The bovine milk protein lactoferrin (LF) has attracted interest of nutraceutical, food and dairy industries for its numerous properties-ranging from anti-viral and anti-microbial to immunological-making it a potential functional ingredient in a wide variety of food applications to maintain health. Importantly, bovine LF was found to exert anti-viral activities against several types of viruses, including certain SARS-CoV-2 variants. LF's potential effect on COVID-19 patients has seen a rapid increase of in vitro and in vivo studies published, resulting in a model on how LF might play a role during different phases of SARS-CoV-2 infection. Aim of this narrative review is two-fold: (1) to highlight the most relevant findings concerning LF's anti-viral, anti-microbial, iron-binding, immunomodulatory, microbiota-modulatory and intestinal barrier properties that support health of the two most affected organs in COVID-19 patients (lungs and gut), and (2) to explore the possible underlying mechanisms governing its mode of action. Thanks to its potential effects on health, bovine LF can be considered a good candidate for nutritional interventions counteracting SARS-CoV-2 infection and related COVID-19 pathogenesis.

Reaching the Final Endgame for Constant Waves of COVID-19

Despite intramuscular vaccines saving millions of lives, constant devastating waves of SARS-CoV-2 infections continue. The elimination of COVID-19 is challenging, but necessary in order to avoid millions more people who would suffer from long COVID if we fail. Our paper describes rapidly advancing and innovative therapeutic strategies for the early stage of infection with COVID-19 so that tolerating continuing cycles of infection should be unnecessary in the future. These therapies include new vaccines with broader specificities, nasal therapies and antiviral drugs some targeting COVID-19 at the first stage of infection and preventing the virus entering the body in the first place. Our article describes the advantages and disadvantages of each of these therapeutic options which in various combinations could eventually prevent renewed waves of infection. Finally, important consideration is given to political, social and economic barriers that since 2020 hindered vaccine application and are likely to interfere again with any COVID-19 endgame.

Clinical Characteristics of 254 COVID-19 Inpatients in Yichang, Hubei, China, and Efficacy of Integrated Chinese and Western Medicine Treatment

Introduction

There is no effective treatment plan for coronavirus disease 2019 (COVID-19). We employed a combination of Chinese and Western medicine treatment for some COVID-19 inpatients.

Methods

This study was a prospective cohort study that observed non-critical COVID-19 inpatients. The differences will be observed in the time from admission to two consecutive 2019-nCoV nucleic acid test negatives and the Visual Analog Scale (VAS) score between the two groups.

Results

A total of 254 confirmed COVID-19 patients were included in this study. The median time from the admission to two consecutive negative nucleic acid tests was 14 days for the integrated Chinese and Western Medicine (ICWM) group, while the Western Medicine (WM) group was 16 days. Besides, the median VAS score of the ICWM group was 0, which was an average decrease of 2 points compared to the time of admission.

Conclusion

For non-critical COVID-19 patients, it was safe and have more benefits to add traditional Chinese medicine decoction based on WM treatment.

Potential of ATR-FTIR-Chemometrics in Covid-19: Disease Recognition

The COVID-19 pandemic has caused major disturbances to human health and economy on a global scale. Although vaccination campaigns and important advances in treatments have been developed, an early diagnosis is still crucial. While PCR is the golden standard for diagnosing SARS-CoV-2 infection, rapid and low-cost techniques such as ATR-FTIR followed by multivariate analyses, where dimensions are reduced for obtaining valuable information from highly complex data sets, have been investigated. Most dimensionality reduction techniques attempt to discriminate and create new combinations of attributes prior to the classification stage; thus, the user needs to optimize a wealth of parameters before reaching reliable and valid outcomes. In this work, we developed a method for evaluating SARS-CoV-2 infection and COVID-19 disease severity on infrared spectra of sera, based on a rather simple feature selection technique (correlation-based feature subset selection). Dengue infection was also evaluated for assessing whether selectivity toward a different virus was possible with the same algorithm, although independent models were built for both viruses. High sensitivity (94.55%) and high specificity (98.44%) were obtained for assessing SARS-CoV-2 infection with our model; for severe COVID-19 disease classification, sensitivity is 70.97% and specificity is 94.95%; for mild disease classification, sensitivity is 33.33% and specificity is 94.64%; and for dengue infection assessment, sensitivity is 84.27% and specificity is 94.64%.

A Novel Antiviral Protein Derived from Oenanthe javanica: Type I Interferon-Dependent Antiviral Signaling and Its Pharmacological Potential

Pathogenesis-related (PR) proteins produced in plants play a crucial role in self-defense against microbial attacks. Previously, we have identified a novel PR-1-like protein (OPRP) from Oenanthe javanica and examined its pharmacologic relevance and cell signaling in mammalian cells. Purified full-length OPRP protein significantly increased toll-like receptor 4 (TLR4)-dependent expression levels of genes such as inducible nitric oxide synthase (iNOS), tumor necrosis factor α (TNF-α), interleukin 6 (IL-6), and CD80. We also found that small peptides (OPRP2 and OPRP3) designed from OPRP remarkably upregulated myxovirus resistance (Mx1), 2′-5′ oligoadenylate sythetase (OAS), and interferon (IFN) α/β genes in mouse splenocytes as well as human epithelial cells. Notably, OPRP protein distinctively activated STAT1 phosphorylation and ISGF-3γ. Interestingly, OPRP2 and OPRP3 were internalized to the cytoplasm and triggered dimerization of STAT1/STAT2, followed by upregulation of type I IFN-dependent antiviral cytokines. Moreover, OPRP1 successfully inhibited viral (Pseudo SARS-CoV-2) entry into host cells. Taken together, we conclude that OPRP and its small peptides (OPRP1 to 3) present a new therapeutic intervention for modulating innate immune activity through type I IFN-dependent antiviral signaling and a new therapeutic approach that drives an antiviral state in non-immune cells by producing antiviral cytokines.

How to Restore Oxidative Balance That Was Disrupted by SARS-CoV-2 Infection

Coronavirus 2019 disease (COVID-19) is caused by different variants of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) which emerged in December of 2019. COVID-19 pathogenesis is complex and involves a dysregulated renin angiotensin system. Severe courses of the disease are associated with a dysregulated immunological response known as cytokine storm. Many scientists have demonstrated that SARS-CoV-2 impacts oxidative homeostasis and stimulates the production of reactive oxygen species (ROS). In addition, the virus inhibits glutathione (GSH) and nuclear factor erythroid 2-related factor 2 (NRF2)-a major antioxidant which induces expression of protective proteins and prevents ROS damage. Furthermore, the virus stimulates NOD-, LRR- and pyrin domain-containing protein 3 (NLRP3) inflammasomes which play a significant role in inducing a cytokine storm. A variety of agents with antioxidant properties have shown beneficial effects in experimental and clinical studies of COVID-19. This review aims to present mechanisms of oxidative stress induced by SARS-CoV-2 and to discuss whether antioxidative drugs can counteract detrimental outcomes of a cytokine storm.

Human Cell Organelles in SARS-CoV-2 Infection: An Up-to-Date Overview

Since the end of 2019, the whole world has been struggling with the life-threatening pandemic amongst all age groups and geographic areas caused by Severe Acute Respiratory Syndrome Coronavirus (SARS-CoV-2). The Coronavirus Disease 2019 (COVID-19) pandemic, which has led to more than 468 million cases and over 6 million deaths reported worldwide (as of 20 March 2022), is one of the greatest threats to human health in history. Meanwhile, the lack of specific and irresistible treatment modalities provoked concentrated efforts in scientists around the world. Various mechanisms of cell entry and cellular dysfunction were initially proclaimed. Especially, mitochondria and cell membrane are crucial for the course of infection. The SARS-CoV-2 invasion depends on angiotensin converting enzyme 2 (ACE2), transmembrane serine protease 2 (TMPRSS2), and cluster of differentiation 147 (CD147), expressed on host cells. Moreover, in this narrative review, we aim to discuss other cell organelles targeted by SARS-CoV-2. Lastly, we briefly summarize the studies on various drugs.

The Inflammatory Cytokine Imbalance for Miscarriage, Pregnancy Loss and COVID-19 Pneumonia

Pregnancy can be defined a vascular event upon endocrine control. In the human hemo-chorial placentation the chorionic villi penetrate the wall of the uterine spiral arteries, to provide increasing amounts of nutrients and oxygen for optimal fetal growth. In any physiological pregnancy the natural maternal response is of a Th1 inflammatory type, aimed at avoiding blood loss through the arteriolar wall openings. The control of the vascular function, during gestation as in any other condition, is achieved through the action of two main types of prostanoids: prostaglandin E2 and thromboxane on the one hand (for vasoconstriction and coagulation), prostacyclin on the other (for vasodilation and blood fluidification). The control of the maternal immune response is upon the responsibility of the fetus itself. Indeed, the chorionic villi are able to counteract the natural maternal response, thus changing the inflammatory Th1 type into the anti-inflammatory Th2. Clinical and experimental research in the past half century address to inflammation as the leading cause of abortion, pregnancy loss, premature delivery and related pulmonary, cerebral, intestinal fetal syndromes. Increased level of Interleukin 6, Interleukin 1-beta, Tumor Necrosis Factor-alfa, Interferon-gamma, are some among the well-known markers of gestational inflammation. On the other side, COVID-19 pneumonia is a result of extensive inflammation induced by viral replication within the cells of the respiratory tract. As it may happen in the uterine arteries in the absence of an effective fetal control, viral pneumonia triggers pulmonary vascular coagulation. The cytokines involved in the process are the same as those in gestational inflammation. As the fetus breathes throughout the placenta, fetal death from placental thrombosis is similar to adult death from pulmonary thrombosis. Preventing and counteracting inflammation is mandatory in both conditions. The most relevant literature dealing with the above-mentioned concepts is reviewed in the present article.