COVID-19: angiotensin-converting enzyme 2 (ACE2) expression and tissue susceptibility to SARS-CoV-2 infection

Structural aspects of SARS-CoV-2 mutations: Implications to plausible infectivity with ACE-2 using computational modeling approach

Some of the SARS-CoV-2 variants are said to be more infectious than the previous others and are causing panic around the globe. Cases related to Delta plus (δ+) and omicron (ο) variants are on the rise worldwide. This sudden surge warrants an investigation into the reasons for its binding with ACE-2. The present study attempts to find out the structural basis of binding interactions of SARS-CoV-2 mutants based on computational modeling and comparative analysis. In silico strategies including protein-protein docking, mutation analysis, molecular dynamics, and binding energy calculations were used to study the binding of the 'receptor binding domain' (RBD) of the seven 'variants of concern' which include Alpha (α), Beta (β), Gamma (γ), Kappa (κ), Delta (δ), Delta plus (δ+) and omicron (ο) with ACE-2 (human angiotensin-converting enzyme-2) and with antibodies. Among all the variants dealt with in this study, Delta plus and omicron were found to be binding more strongly to ACE-2 than others due to inherent mutations and the consequent change in the hydrophilic and hydrophobic environment of the binding site. Furthermore, molecular dynamic (MD) simulations and subsequent MM/PBSA calculations provided useful structural insights into key residues participating in the interaction. Infectivity of a virus could be dependent on the interplay of evading antibodies and simultaneously attaching strongly with the host receptor. A cross-correlation between mutant spike proteins' binding with ACE-2 and antibodies provides a holistic assessment of the binding nature of these mutants vis-à-vis native virus and offers opportunities for designing potential therapeutics against these new mutants.

A Machine Learning Model for Predicting Hospitalization in Patients with Respiratory Symptoms during the COVID-19 Pandemic

A machine learning approach is a useful tool for risk-stratifying patients with respiratory symptoms during the COVID-19 pandemic, as it is still evolving. We aimed to verify the predictive capacity of a gradient boosting decision trees (XGboost) algorithm to select the most important predictors including clinical and demographic parameters in patients who sought medical support due to respiratory signs and symptoms (RAPID RISK COVID-19). A total of 7336 patients were enrolled in the study, including 6596 patients that did not require hospitalization and 740 that required hospitalization. We identified that patients with respiratory signs and symptoms, in particular, lower oxyhemoglobin saturation by pulse oximetry (SpO₂) and higher respiratory rate, fever, higher heart rate, and lower levels of blood pressure, associated with age, male sex, and the underlying conditions of diabetes mellitus and hypertension, required hospitalization more often. The predictive model yielded a ROC curve with an area under the curve (AUC) of 0.9181 (95% CI, 0.9001 to 0.9361). In conclusion, our model had a high discriminatory value which enabled the identification of a clinical and demographic profile predictive, preventive, and personalized of COVID-19 severity symptoms.

Analysis of potential risk factors associated with COVID-19 and hospitalization

Coronavirus disease 2019 (COVID-19) was found to cause complications in certain groups of people, leading to hospitalization. Several factors have been linked to this, such as gender, age, comorbidity, and race. Understanding the precise reasons for the COVID-19-induced complications might help in designing strategies to minimize hospitalization. A retrospective, cross-sectional observational study was conducted for patients in a COVID-19-designated specialty hospital after obtaining ethical clearance. Patients' demographic and clinical characteristics, such as age, gender, race, vaccinated status, complications, comorbidities, and medications, were retrieved from the hospital medical database. The data were statistically analyzed to determine the association between the predictors and the outcomes of COVID-19. An odds ratio (both unadjusted and adjusted) analysis was carried out to determine the risk factors for hospitalization [non-intensive care (non-ICU) and intensive care (ICU)] due to COVID-19. The data from the study indicated that the majority of patients hospitalized due to COVID-19 were male (>55%), aged > 60 years (>40%), married (>80%), and unvaccinated (>71%). The common symptoms, complications, comorbidities, and medications were fever, pneumonia, hypertension, and prednisolone, respectively. Male gender, patients older than 60 years, unemployed, unvaccinated, complicated, and comorbid patients had an odds ratio of more than 2 and were found to be significantly (p < 0.05) higher in ICU admission. In addition, administration of prednisolone and remdesivir was found to significantly reduce (p < 0.05) the odds ratio in ICU patients. The analysis of the data suggested that male gender, age above 60 years, and unvaccinated with comorbidities increased the complications and resulted in hospitalization, including ICU admission. Hypertension and type 2 diabetes associated with obesity as metabolic syndrome could be considered one of the major risk factors. Preventive strategies need to be directed toward these risk factors to reduce the complications, as well as hospitalization to defeat the COVID-19 pandemic.

SARS-CoV-2 Infection in Pregnancy: Placental Histomorphological Patterns, Disease Severity and Perinatal Outcomes

The association between maternal COVID-19 infection, placental histomorphology and perinatal outcomes is uncertain. The published studies on how placental structure is affected after SARS-CoV-2 virus in COVID-19-infected pregnant women are lacking. We investigated the effects of maternal SARS-CoV-2 infection on placental histomorphology and pregnancy outcomes. A retrospective cohort study on 47 pregnant women with confirmed SARS-CoV-2 infection, matched with non-infected controls, was conducted. Relevant clinicopathological data and primary birth outcomes were recorded. Histomorphology and SARS-CoV-2 immunohistochemistry analyses of placental tissues were performed. Only 1 of 47 cases showed SARS-CoV-2 immunoreactivity in the syncytiotrophoblasts. Histologically, decidual vasculopathy (n = 22/47, p = 0.004), maternal vascular thrombosis (n = 9/47, p = 0.015) and chronic histiocytic intervillositis (n = 10/47, p = 0.027) were significantly higher in the COVID-19-infected placentas when compared to the control group. Maternal vascular thrombosis was a significant feature in the active COVID-19 group. A significant lower gestational age (p < 0.001)) at delivery and a higher caesarean section rate (p = 0.007) were observed in the active SARS-CoV-2-infected cases, resulting in a significant lower fetal-placental weight ratio (p = 0.022) and poorer Apgar score (p < 0.001). Notably, active (p = 0.027), symptomatic (p = 0.039), severe-critical (p = 0.002) maternal COVID-19 infection and placental inflammation (p = 0.011) were associated with an increased risk of preterm delivery. Altered placental villous maturation and severe-critical maternal COVID-19 infection were associated with an elevated risk of poor Apgar scores at birth (p = 0.018) and maternal mortality (p = 0.023), respectively.

Research progress of biosensors for detection of SARS-CoV-2 variants based on ACE2

Currently, the coronavirus disease 2019 (COVID-19) pandemic is ravaging the world, causing serious crisis in economy and human health. The top priority is the detection and drug development of the novel coronavirus. The gold standard for real-time diagnosis of coronavirus disease is the reverse transcription-polymerase chain reaction (RT-PCR), which is usually operatively complex and time-consuming. Biosensors are known for their low cost and rapid detection, which are developing rapidly in detecting severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The current study showed that the spike protein of SARS-CoV-2 will bind to angiotensin-converting hormone 2 (ACE2) to mediate the entry of the virus into cells. Interestingly, the affinity between ACE2 and SARS-CoV-2 spike protein increases with the mutation of the virus. Using ACE2 as a biosensor recognition receptor to detect SARS-CoV-2 will effectively avoid the decline of detection accuracy and false negative caused by variants. In fact, due to the variation of the virus, it may even lead to enhanced detection performance. In addition, ACE2-specific drugs to prevent SARS-CoV-2 from entering cells will be effectively evaluated using the biosensors even with virus mutations. Here, we reviewed the biosensors for rapid detection of SARS-CoV-2 by ACE2 and discussed the advantages of ACE2 as an antibody for the detection of SARS-CoV-2 variants. The review also discussed the value of ACE2-based biosensors for screening for drugs that modulate the interaction between ACE2 and SARS-CoV-2.

Are hemoglobin-derived peptides involved in the neuropsychiatric symptoms caused by SARS-CoV-2 infection?

Follow-up of patients affected by COVID-19 has unveiled remarkable findings. Among the several sequelae caused by SARS-CoV-2 viral infection, it is particularly noteworthy that patients are prone to developing depression, anxiety, cognitive disorders, and dementia as part of the post-COVID-19 syndrome. The multisystem aspects of this disease suggest that multiple mechanisms may converge towards post-infection clinical manifestations. The literature provides mechanistic hypotheses related to changes in classical neurotransmission evoked by SARS-CoV-2 infection; nonetheless, the interaction of peripherally originated classical and non-canonic peptidergic systems may play a putative role in this neuropathology. A wealth of robust findings shows that hemoglobin-derived peptides are able to control cognition, memory, anxiety, and depression through different mechanisms. Early erythrocytic death is found during COVID-19, which would cause excess production of hemoglobin-derived peptides. Following from this premise, the present review sheds light on a possible involvement of hemoglobin-derived molecules in the COVID-19 pathophysiology by fostering neuroscientific evidence that supports the contribution of this non-canonic peptidergic pathway. This rationale may broaden knowledge beyond the currently available data, motivating further studies in the field and paving ways for novel laboratory tests and clinical approaches.

COVID-19 in Kidney Transplant Recipients With Diabetes Mellitus: A Propensity Score Matching Analysis

Kidney transplant recipients present higher rates of pre-existing comorbidities, in particular diabetes mellitus (DM), hypertension, and cardiac disease. We aimed to verify the main risk factors related to DM that contribute to COVID-19 progression and mortality in a kidney transplant setting. From March to August 2020, we evaluated 300 kidney transplant recipients affected by COVID-19. We used propensity score matching (PSM) to estimate the impact of DM on COVID-19. After matching, all baseline characteristics were well balanced between those with and without DM (n = 100 in each group). Case fatality rate, the requirement of invasive mechanical ventilation (IMV), and acute kidney injury (AKI) were associated with previous fasting blood glucose, and C-reactive protein (CRP), and lactate dehydrogenase (LDH) levels on admission. These findings were similar in kidney transplant patients with and without DM. Glycemia on admission and estimated glomerular filtration rate (eGFR) either on admission or basal correlated to the need of IMV and development of AKI, respectively. Poor glycaemic control, eGFR, markers of inflammation (CRP) and tissue damage (LDH) were indicative of COVID-19 burden in kidney transplant recipients and may be useful tools for risk-stratifying this population, independently of the DM status, during the pandemic.

THE RELATIONSHIP BETWEEN PHYSICAL ACTIVITY AND SEVERITY OF COVID-19 SYMPTOMS IN NON-HOSPITALISED INDIVIDUALS

Background

The study explored the relationship between physical activity (PA) behaviour and severity of symptoms in people infected by coronavirus disease 2019 (COVID-19).

Methods

Five hundred and thirty-three people [16% males, mean age: 45 ± 11 years, body mass index (BMI): 23.3 ± 20] took part in the study. All participants were post-COVID-19 infection. An online questionnaire was used to gather data on; participants demographics, comorbidities and treatment, symptomatology of COVID-19, quality of life (QoL) and pre- and post-COVID-19 infection PA.

Results

Logistic regression revealed that only a high BMI (>25) increased the severity of (odds ratio 1.01; 95% confidence interval, 0.99–1.03) symptoms from none to mild-to-moderate. Weekly PA behaviour (min/week) did not affect the primary outcome (symptom severity) as a predictor variable and neither differ (P > 0.05) between symptomatology for both moderate (no symptoms: 181.3 ± 202.1 vs. mild-to-moderate symptoms: 173 ± 210.3) and vigorous (no symptoms: 89.2 ± 147 vs. mild-to-moderate symptoms: 88.9 ± 148.3) PA. QoL (i.e. mobility, self-care, usual activities, pain/discomfort, anxiety/depression and perceived health) was significantly (P < 0.05) worse post-COVID-19 infection.

Conclusions

Our findings did not present an association between PA levels and mild-to-moderate COVID-19 symptoms. However, all participants exceeded the lower limit of the World Health Organization recommended, adult PA dose. This might explain the lack of PA effect, on mild-to-moderate symptoms post-COVID-19 infection. Future studies should explore the effects of PA levels in more severe cases (e.g. hospitalizations) and assess the effectiveness of PA to reduce hospitalizations, and mortality rates as a result of COVID-19 infection.

Overstimulation of the ergoreflex—A possible mechanism to explain symptoms in long COVID

Long COVID refers to a multitude of symptoms that persist long after SARS-CoV-2 infection. Fatigue and breathlessness are the most common symptoms of long COVID across a range of studies. They are also cardinal symptoms of chronic heart failure (CHF). In this review, we propose that fatigue and breathlessness in patients with long COVID may be explained by skeletal muscle abnormalities, in a manner similar to patients with CHF. The ergoreflex is a cardiorespiratory reflex activated by exercise, which couples ventilation and cardiovascular function to exercise intensity. At least part of the symptomatology of CHF is related to abnormal skeletal muscle and an enhanced ergoreflex, resulting in heightened sympathetic, vasoconstrictor and ventilator drives. Similarly, SARS-CoV-2 infection results in a hyperinflammatory and hypercatabolic state. This leads to reduction in skeletal muscle mass and altered function. We postulate that the ergoreflex is chronically overstimulated, resulting in fatigue and breathlessness. Exercise training preserves muscle mass and function as well as reduces ergoreflex activation; therefore may have a role in improving symptoms associated with long COVID. Should the ergoreflex be proven to be an important pathophysiological mechanism of long COVID, tailored exercise interventions should be trialed with the aim of improving both symptoms and perhaps outcomes in patients with long COVID.

[Clinical features of children with coronavirus disease 2019 Delta variant infection after vaccination with inactivated SARS-CoV-2 vaccine]

OBJECTIVES

To study the clinical features of children with coronavirus disease 2019 (COVID-19) Delta variant infection vaccinated or not vaccinated with inactivated severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccine.

METHODS

A total of 11 children with COVID-19 Delta variant infection who were vaccinated with inactivated SARS-CoV-2 vaccine and were hospitalized in the designated hospital in Henan Province, China, from November 3 to December 17, 2021 were enrolled as the vaccinated group. Thirty-one children with COVID-19 Delta variant infection who were not vaccinated and were hospitalized during the same period were enrolled as the unvaccinated group. A retrospective analysis was performed on their epidemiological data, clinical features, and laboratory examination results.

RESULTS

There was no significant difference in gender composition and disease classification between the two groups (P>0.05), and there was also no significant difference in the incidence rates of the clinical symptoms such as cough, expectoration, and fever between the two groups (P>0.05). No significant difference was found between the two groups in leukocyte count, lymphocyte percentage, alanine aminotransferase, and serum creatinine (P>0.05). Compared with the unvaccinated group, the vaccinated group had significantly lower levels of aspartate aminotransferase, lactate dehydrogenase, and creatine kinase-MB (P<0.05). There was no significant difference between the two groups in the proportion of children with elevated C-reactive protein or procalcitonin and the levels of peripheral blood cytokines (P>0.05). The vaccinated group had significantly lower counts of B lymphocytes and total T lymphocytes (CD3+) than the unvaccinated group (P<0.05). Compared with the unvaccinated group, the vaccinated group had a significantly higher positive rate of IgG on admission and at week 2 of the course of disease (P<0.05), as well as a significantly higher Ct value of nucleic acid at weeks 1 and 2 of the course of disease (P<0.05).

CONCLUSIONS

Vaccination with inactivated SARS-CoV-2 vaccine may reduce myocardial injury caused by SARS-CoV-2 Delta variant. For children with SARS-CoV-2 Delta variant infection after the vaccination, more attention should be paid to their immune function.

RG203KR Mutations in SARS-CoV-2 Nucleocapsid: Assessing the Impact Using a Virus-Like Particle Model System

Since its origin in late 2019, the SARS-CoV-2 virus has been constantly mutating and evolving. Current studies mostly employ spike protein (S) pseudovirus systems to determine the effects of mutations on the infectivity and immunogenicity of variants.

Remdesivir use and risks of acute kidney injury and acute liver injury among patients hospitalised with COVID-19: a self-controlled case series study

BACKGROUND AND AIM

To investigate and quantify the risks of AKI and ALI associated with remdesivir use, given the underlying diseases of SARS-CoV-2 infection.

METHODS

This self-controlled case series (SCCS) study was conducted using electronic hospital records between 23 January 2020 and 31 January 2021 as retrieved from the Hong Kong Hospital Authority which manages all laboratory-confirmed COVID-19 cases in Hong Kong. Outcomes of AKI and ALI were defined using the KDIGO Guideline and Asia Pacific Association of Study of Liver consensus guidelines. Incidence rate ratios (IRR) for AKI and ALI following the administration of remdesivir (exposure) in comparison to a non-exposure period were estimated using the conditional Poisson regression models.

RESULTS

Of 860 COVID-19 patients administered remdesivir during hospitalisation, 334 (38.8%) and 137 (15.9%) had incident ALI and AKI, respectively. Compared with the baseline period, both ALI and AKI risks were increased significantly during the pre-exposure period (ALI: IRR = 6.169, 95% CI = 4.549-8.365; AKI: IRR = 7.074, 95% CI = 3.763-13.298) and remained elevated during remdesivir treatment. Compared to the pre-exposure period, risks of ALI and AKI were not significantly higher in the first 2 days of remdesivir initiation (ALI: IRR = 1.261, 95% CI = 0.915-1.737; AKI: IRR = 1.261, 95% CI = 0.889-1.789) and between days 2 and 5 of remdesivir treatment (ALI: IRR = 1.087, 95% CI = 0.793-1.489; AKI: IRR = 1.152, 95% CI = 0.821-1.616).

CONCLUSION

The increased risks of AKI and ALI associated with intravenous remdesivir treatment for COVID-19 may be due to the underlying SARS-CoV-2 infection. The risks of AKI and ALI were elevated in the pre-exposure period, yet no such increased risks were observed following remdesivir initiation when compared to the pre-exposure period.

Differences in saliva ACE2 activity among infected and non-infected adult and pediatric population exposed to SARS-CoV-2

BACKGROUND

Variations in the ACE2 activity in saliva could explain the striking differences of susceptibility to infection and risk of severe disease.

METHODS

We analyze the activity of ACE2 in saliva in different population groups across a wide age range and disease status during April to June 2020, before SARS-CoV-2 vaccine implementation, and we establish differences between infected people and participants considered resistant (highly exposed healthcare workers and children who cohabited with parents with COVID-19 without isolation and remain IgG negative).

RESULTS

We included 74 adults, of which 47 (64%) were susceptible and 27 (36%) were resistant, and 79 children, of which 41 (52%) were susceptible and 38 (48%) were resistant. Resistant adults have significantly lower ACE2 activity in saliva than susceptible adults and non-significant higher values than susceptible and resistant children. ACE2 activity is similar in the susceptible and resistant pediatric population (p = 0.527). In contrast, we observe an increase in activity as the disease's severity increases among the adult population (mild disease vs. severe disease, 39 vs. 105 FU, p = 0.039; severe disease vs. resistant, 105 vs. 31 FU, p < 0.001).

CONCLUSIONS

using an enzymatic test, we show that ACE2 activity in saliva correlates with the susceptibility to SARS-Cov-2 infection and disease severity. Children and adults with low-susceptibility to SARS-Cov-2 infection showed the lowest ACE2 activity. These findings could inform future strategies to identify at-risk individuals.

Enzymes in the time of COVID-19: An overview about the effects in the human body, enzyme market, and perspectives for new drugs

The rising pandemic caused by a coronavirus, resulted in a scientific quest to discover some effective treatments against its etiologic agent, the severe acute respiratory syndrome‐coronavirus 2 (SARS‐CoV‐2). This research represented a significant scientific landmark and resulted in many medical advances. However, efforts to understand the viral mechanism of action and how the human body machinery is subverted during the infection are still ongoing. Herein, we contributed to this field with this compilation of the roles of both viral and human enzymes in the context of SARS‐CoV‐2 infection. In this sense, this overview reports that proteases are vital for the infection to take place: from SARS‐CoV‐2 perspective, the main protease (M^pro) and papain‐like protease (PL^pro) are highlighted; from the human body, angiotensin‐converting enzyme‐2, transmembrane serine protease‐2, and cathepsins (CatB/L) are pointed out. In addition, the influence of the virus on other enzymes is reported as the JAK/STAT pathway and the levels of lipase, enzymes from the cholesterol metabolism pathway, amylase, aspartate aminotransferase, alanine aminotransferase, lactate dehydrogenase, and glyceraldehyde 3‐phosphate dehydrogenase are also be disturbed in SARS‐CoV‐2 infection. Finally, this paper discusses the importance of detailed enzymatic studies for future treatments against SARS‐CoV‐2, and how some issues related to the syndrome treatment can create opportunities in the biotechnological market of enzymes and the development of new drugs.

Molecular characteristics, immune evasion, and impact of SARS-CoV-2 variants

The persistent COVID-19 pandemic since 2020 has brought an enormous public health burden to the global society and is accompanied by various evolution of the virus genome. The consistently emerging SARS-CoV-2 variants harboring critical mutations impact the molecular characteristics of viral proteins and display heterogeneous behaviors in immune evasion, transmissibility, and the clinical manifestation during infection, which differ each strain and endow them with distinguished features during populational spread. Several SARS-CoV-2 variants, identified as Variants of Concern (VOC) by the World Health Organization, challenged global efforts on COVID-19 control due to the rapid worldwide spread and enhanced immune evasion from current antibodies and vaccines. Moreover, the recent Omicron variant even exacerbated the global anxiety in the continuous pandemic. Its significant evasion from current medical treatment and disease control even highlights the necessity of combinatory investigation of the mutational pattern and influence of the mutations on viral dynamics against populational immunity, which would greatly facilitate drug and vaccine development and benefit the global public health policymaking. Hence in this review, we summarized the molecular characteristics, immune evasion, and impacts of the SARS-CoV-2 variants and focused on the parallel comparison of different variants in mutational profile, transmissibility and tropism alteration, treatment effectiveness, and clinical manifestations, in order to provide a comprehensive landscape for SARS-CoV-2 variant research.

Molecular Imaging on ACE2-dependent Transocular Infection of Coronavirus

A transocular infection has been proved as one of the main approaches that severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) invades the body, and angiotensin‐converting enzyme 2 (ACE2) plays a key role in this procedure. Dynamic and quantitative details on virus distribution are lacking for virus prevention and drug design. In this study, a radiotraceable pseudovirus packed with an enhanced green fluorescent protein (EGFP) gene, ¹²⁵I‐CoV, was prepared and inoculated in the unilateral eye of humanized ACE2 (hACE2) mice or ACE2‐knockout (ACE2‐KO) mice. Single‐photon emission computed tomography/computed tomography images were acquired at multiple time points to exhibit ACE2‐dependent procedures from invasion to clearance. Positron emission tomography (PET) and western blot were performed to quantify ACE2 expression and verify the factors affecting transocular infection. For the transocular infection of coronavirus (CoV), the renin–angiotensin–aldosterone system (RAAS), lungs, intestines, and genital glands were the main targeted organs. Due to the specific anchor to ACE2‐expressed host cells, virus concentrations in genital glands, liver, and lungs ranked the top three most and stabilized at 3.75 ± 0.55, 3.30 ± 0.25, and 2.10 ± 0.55% inoculated dose (ID)/mL at 48 h post treatment. Meanwhile, ACE2‐KO mice had already completed the in vivo clearance. In consideration of organ volumes, lungs (14.50 ± 3.75%ID) and liver (10.94 ± 0.71%ID) were the main in‐store reservoirs of CoV. However, the inoculated eye (5.52 ± 1.85%ID for hACE2, 5.24 ± 1.45%ID for ACE2‐KO, p > 0.05) and the adjacent brain exhibited ACE2‐independent virus infection at the end of 72 h observation, and absolute amount of virus played a key role in host cell infection. These observations on CoV infection were further manifested by infection‐driven intracellular EGFP expression. ACE2 PET revealed an infection‐related systematic upregulation of ACE2 expression in the organs involved in RAAS (e.g., brain, lung, heart, liver, and kidney) and the organ that was of own local renin–angiotensin system (e.g., eye). Transocular infection of CoV is ACE2‐dependent and constitutes the cause of disturbed ACE2 expression in the host. The brain, genital glands, and intestines were of the highest unit uptake, potentially accounting for the sequelae. Lungs and liver were of the highest absolute amount, closely related to the respiratory diffusion and in vivo duplication. ACE2 expression was upregulated in the short term after infection with CoV. These visual and quantitative results are helpful to fully understanding the transocular path of SARS‐CoV‐2 and other CoVs.

The Variable Nature of Vitamin C—Does It Help When Dealing with Coronavirus?

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is still spreading worldwide. For this reason, new treatment methods are constantly being researched. Consequently, new and already-known preparations are being investigated to potentially reduce the severe course of coronavirus disease 2019 (COVID-19). SARS-CoV-2 infection induces the production of pro-inflammatory cytokines and acute serum biomarkers in the host organism. In addition to antiviral drugs, there are other substances being used in the treatment of COVID-19, e.g., those with antioxidant properties, such as vitamin C (VC). Exciting aspects of the use of VC in antiviral therapy are its antioxidant and pro-oxidative abilities. In this review, we summarized both the positive effects of using VC in treating infections caused by SARS-CoV-2 in the light of the available research. We have tried to answer the question as to whether the use of high doses of VC brings the expected benefits in the treatment of COVID-19 and whether such treatment is the correct therapeutic choice. Each case requires individual assessment to determine whether the positives outweigh the negatives, especially in the light of populational studies concerning the genetic differentiation of genes encoding the solute carriers responsible forVC adsorption. Few data are available on the influence of VC on the course of SARS-CoV-2 infection. Deducing from already-published data, high-dose intravenous vitamin C (HDIVC) does not significantly lower the mortality or length of hospitalization. However, some data prove, among other things, its impact on the serum levels of inflammatory markers. Finally, the non-positive effect of VC administration is mainly neutral, but the negative effect is that it can result in urinary stones or nephropathies.

In vitro and in silico Evaluation of ACE2 and LOX Inhibitory Activity of Eucalyptus Essential Oils, 1,8-Cineole, and Citronellal

Eucalyptus essential oils are well-known and used especially in upper respiratory tract pathologies or diseases as herbal drug preparations. In the present study, the in vitro angiotensin-converting enzyme 2 (ACE2) and lipoxygenase (LOX) enzyme inhibitory potentials of commercial Eucalyptus globulus Labill. and Eucalyptus citriodora Hook. essential oils were evaluated for their potential anti-coronavirus disease 2019 (COVID-19), and anti-inflammatory effects. In addition, the major components, 1,8-cineole and citronellal, were evaluated for their ability to bind at the active site of either human ACE2 or human 5-LOX using an in silico setting. Before activity evaluation, Eucalyptus globulus and E citriodora essential oils were analysed by GC/FID and GC/MS, where 1,8-cineole (30%), and citronellal (80%) were identified as the major components, respectively. The in vitro ACE2 inhibition was calculated as 94.9% for E globulus, and that of E citriodora essential oil as 83.4%. In vitro LOX inhibition experiments for essential oils in the same order showed inhibitions of 71.3 and 91.4%, respectively, at 20 µg/mL test concentrations in microplate-based fluorometric assays. In addition, protein–ligand docking, and interaction profiling was used to gain structural and mechanistic insights into the in silico ACE2 and LOX inhibitory potentials of the major Eucalyptus essential oil constituents, 1,8-cineole as well as citronellal. The resulting data supported the in vitro findings; however, further in vivo studies are needed to confirm the activity.

MicroRNAs in the development of potential therapeutic targets against COVID-19: A narrative review

Background

As the therapeutic regimens against the COVID-19 remain scarce, the microRNAs (miRNAs) can be exploited to generate efficient therapeutic targets. The miRNAs have been found to play pivotal roles in the several regulatory functions influencing the prognosis of viral infection. The miRNAs have a prospective role in the up and down regulation of the ACE2 receptors. This review examines the clinical applications, as well as the possible threats associated with the use of miRNAs to combat the deleterious consequences of SARS-CoV-2 infection.

Methodology

This article was compiled to evaluate how the miRNAs are involved in the SARS-CoV-2 pathogenesis and infection, and their potential functions which could help in the development of therapeutic targets against the COVID-19. The sources of the collected information include the several journals, databases and scientific search engines such as the Google scholar, Pubmed, Science direct, official website of WHO, among the other sites. The investigations on the online platform were conducted using the keywords miRNA biogenesis, miRNA and ACE2 interaction, therapeutic role of miRNAs against SARS-CoV-2 and miRNA therapy side effects.

Results

This review has highlighted that the miRNAs can be exploited to generate potential therapeutic targets against the COVID-19. Changes in the miRNA levels following viral replication are an essential component of the host response to infection. The collection and modification of miRNA modulates may help to minimize the deleterious consequences of SARS-CoV-2 infection, such as by controlling or inhibiting the generation of cytokines and chemokines. The degradation of viral RNA by the cellular miRNAs, along with the reduced expression of ACE2 receptors, can substantially reduce the viral load. Specific miRNAs have been found to have an antiviral influence, allowing the immune system to combat the infection or forcing the virus into a latency stage.

Conclusion

This review summarizes several studies revealing the involvement of miRNAs in diverse and complex processes during the infection process of SARS-CoV-2. The miRNAs can substantially reduce the viral load by degradation of viral RNA and reduced expression of ACE2 receptors, besides mitigating the deleterious consequences of the exaggerated secretion of cytokines. Extensive investigations need to be done by the scientific community to utilize the miRNA based strategies for the development of effective therapeutic targets against the COVID-19.

Advances in Nanomaterial-Based Platforms to Combat COVID-19: Diagnostics, Preventions, Therapeutics, and Vaccine Developments

The COVID-19 pandemic caused by the SARS-CoV-2, a ribonucleic acid (RNA) virus that emerged less than two years ago but has caused nearly 6.1 million deaths to date. Recently developed variants of the SARS-CoV-2 virus have been shown to be more potent and expanded at a faster rate. Until now, there is no specific and effective treatment for SARS-CoV-2 in terms of reliable and sustainable recovery. Precaution, prevention, and vaccinations are the only ways to keep the pandemic situation under control. Medical and scientific professionals are now focusing on the repurposing of previous technology and trying to develop more fruitful methodologies to detect the presence of viruses, treat the patients, precautionary items, and vaccine developments. Nanomedicine or nanobased platforms can play a crucial role in these fronts. Researchers are working on many effective approaches by nanosized particles to combat SARS-CoV-2. The role of a nanobased platform to combat SARS-CoV-2 is extremely diverse (i.e., mark to personal protective suit, rapid diagnostic tool to targeted treatment, and vaccine developments). Although there are many theoretical possibilities of a nanobased platform to combat SARS-CoV-2, until now there is an inadequate number of research targeting SARS-CoV-2 to explore such scenarios. This unique mini-review aims to compile and elaborate on the recent advances of nanobased approaches from prevention, diagnostics, treatment to vaccine developments against SARS-CoV-2, and associated challenges.

Post-Coronavirus Disease 2019 Pulmonary Fibrosis: Wait or Needs Intervention

Coronavirus disease 2019 (COVID-19) has become a major health burden worldwide, with over 450 million confirmed cases and 6 million deaths. Although the acute phase of COVID-19 management has been established, there is still a long way to go to evaluate the long-term clinical course or manage complications due to the relatively short outbreak of the virus. Pulmonary fibrosis is one of the most common respiratory complications associated with COVID-19. Scarring throughout the lungs after viral or bacterial pulmonary infection have been commonly observed, but the prevalence of post-COVID-19 pulmonary fibrosis is rapidly increasing. However, there is limited information available about post-COVID-19 pulmonary fibrosis, and there is also a lack of consensus on what condition should be defined as post-COVID-19 pulmonary fibrosis. During a relatively short follow-up period of approximately 1 year, lesions considered related to pulmonary fibrosis often showed gradual improvement; therefore, it is questionable at what time point fibrosis should be evaluated. In this review, we investigated the epidemiology, risk factors, pathogenesis, and management of post-COVID-19 pulmonary fibrosis.

Biomarkers of Volume Overload and Edema in Heart Failure With Reduced Ejection Fraction

From a pathogenetic point of view, heart failure (HF) is characterized by the activation of several neurohumoral pathways with a role in maintaining the cardiac output and the adequate perfusion pressure in target organs and tissues. Decreased cardiac output in HF with reduced ejection fraction causes activation of the sympathetic nervous system, the renin angiotensin aldosterone system, arginine-vasopressin system, natriuretic peptides, and endothelin, all of which cause water and salt retention in the body. As a result, patients will present clinically as the main symptoms: dyspnea and peripheral edema caused by fluid redistribution to the lungs and/or by fluid overload. By studying these pathophysiological mechanisms, biomarkers with a prognostic and therapeutic role in the management of edema were identified in patients with HF with low ejection fraction. This review aims to summarize the current data from the specialty literature of such biomarkers with a role in the pathogenesis of edema in HF with low ejection fraction. These biomarkers may be the basis for risk stratification and the development of new therapeutic means in the treatment of edema in these patients.

Long COVID, neuropsychiatric disorders, psychotropics, present and future

Long COVID refers to the lingering symptoms which persist or appear after the acute illness. The dominant long COVID symptoms in the two years since the pandemic began (2020-2021) have been depression, anxiety, fatigue, concentration and cognitive impairments with few reports of psychosis. Whether other symptoms will appear later on is not yet known. For example, dopamine-dependent movement disorders generally take many years before first symptoms are seen. Post-stroke depression and anxiety may explain many of the early long COVID cases. Hemorrhagic, hypoxic and inflammatory damages of the central nervous system, unresolved systematic inflammation, metabolic impairment, cerebral vascular accidents such as stroke, hypoxia from pulmonary damages and fibrotic changes are among the major causes of long COVID. Glucose metabolic and hypoxic brain issues likely predispose subjects with pre-existing diabetes, cardiovascular or lung problems to long COVID as well. Preliminary data suggest that psychotropic medications may not be a danger but could instead be beneficial in combating COVID-19 infection. The same is true for diabetes medications such as metformin. Thus, a focus on sigma-1 receptor ligands and glucose metabolism is expected to be useful for new drug development as well as the repurposing of current drugs. The reported protective effects of psychotropics and antihistamines against COVID-19, the earlier reports of reduced number of sigma-1 receptors in post-mortem schizophrenic brains, with many antidepressant and antipsychotic drugs being antihistamines with significant affinity for the sigma-1 receptor, support the role of sigma and histamine receptors in neuroinflammation and viral infections. Literature and data in all these areas are accumulating at a fast rate. We reviewed and discussed the relevant and important literature.

Influence of Increasing Age and Body Mass Index of Gender in COVID-19 Patients

Background: The impact of gender on outcomes in patients suffering from coronavirus disease 2019 (COVID-19) is frequently debated. However, the synchronous influence of additional risk factors is seldom mentioned. With increasing emphasis on identifying patients who are at risk of complications from COVID-19, we decided to conduct a retrospective review to assess the influence of age and body mass index (BMI) on gender-based differences in outcomes. Materials and Methods: A retrospective review of 1288 patients was conducted at a tertiary care hospital. Binary logistic regression was used to assess differences in risk factors and outcomes between genders. The associations between predictors and outcomes were described using odds ratios in tables, forest plots, and regression curves plotted using Sigma Plot. Results: Majority of patients were women (53.6% vs. 46.4%). Median BMI in men was higher than women (p = 0.003). Key predictors for all-cause morbidity/mortality in men were diabetes, chronic kidney disease, and regular use of angiotensin-converting enzyme inhibitors. In women, age >65 and regular use of inhaled steroid were additional risk factors. Men had a higher risk of acute respiratory distress syndrome (2.83 [1.70-4.70]), acute renal failure (1.96 [1.20-3.20]), and had a longer length of stay (0.11 [1.52]). Obesity has a stronger bearing on outcomes in women, and age has a more pronounced effect on outcomes in men. Conclusion: Extremes of BMI and older age are associated with worse outcomes in both men and women. Obesity has a stronger bearing on outcomes of COVID-19 infection in women, while the effect of older age on outcomes is more pronounced in men.

The NLRP3 inflammasome: molecular activation and regulation in spermatogenesis and male infertility; a systematic review

Background

Infertility related to varicocele, infections, metabolic dysfunctions, oxidative stress and environmental toxicants is also associated with inflammatory processes that ultimately lead to the activation of the inflammasome pathway (IP). IP is classically activated by DAMPs, MAMPs or LAMPs, which stand for Damage-, Microbe- or Lifestyle-Associated Molecular Patterns, respectively. The most important player in IP activation is the NLRP3 (NOD[Nuclear oligomerization domain]-, LRR[Leucine rich repeat]- and pyrin domain-containing protein 3) which functions as an intracellular sensor of D/M/L-AMPs resulting in activation of caspase-1, promotion of apoptosis, pyroptosis and generation of inflammatory cytokines. This review addresses the question of whether IP activation might be associated with male infertility situations.

Results & conclusions

We conducted a systematic review of articles published in the Google Scholar, and PubMed databases through October 2021. It turns out that inflammasome activation and its consequences including cytokine storms, apoptosis and pyroptosis could be associated with the reduced sperm count as well as the structural and functional sperm defects recorded in several situations associated with male infertility suggesting that anti-inflammatory therapeutic strategies could be possibly considered to restore male fertility in future research.

COVID-19 infection: an overview on cytokine storm and related interventions

Coronavirus disease 2019 (COVID-19) caused by the severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) has posed a significant threat to global health. This virus affects the respiratory tract and usually leads to pneumonia in most patients and acute respiratory distress syndrome (ARDS) in 15% of cases. ARDS is one of the leading causes of death in patients with COVID-19 and is mainly triggered by elevated levels of pro-inflammatory cytokines, referred to as cytokine storm. Interleukins, such as interleukin-6 (1L-6), interleukin-1 (IL-1), interleukin-17 (IL-17), and tumor necrosis factor-alpha (TNF-α) play a very significant role in lung damage in ARDS patients through the impairments of the respiratory epithelium. Cytokine storm is defined as acute overproduction and uncontrolled release of pro-inflammatory markers, both locally and systemically. The eradication of COVID-19 is currently practically impossible, and there is no specific treatment for critically ill patients with COVID-19; however, suppressing the inflammatory response may be a possible strategy. In light of this, we review the efficacy of specific inhibitors of IL6, IL1, IL-17, and TNF-α for treating COVID-19-related infections to manage COVID-19 and improve the survival rate for patients suffering from severe conditions.

Association of Congenital and Acquired Cardiovascular Conditions With COVID-19 Severity Among Pediatric Patients in the US

IMPORTANCE

Identifying the associations between severe COVID-19 and individual cardiovascular conditions in pediatric patients may inform treatment.

OBJECTIVE

To assess the association between previous or preexisting cardiovascular conditions and severity of COVID-19 in pediatric patients.

DESIGN, SETTING, AND PARTICIPANTS

This retrospective cohort study used data from a large, multicenter, electronic health records database in the US. The cohort included patients aged 2 months to 17 years with a laboratory-confirmed diagnosis of COVID-19 or a diagnosis code indicating infection or exposure to SARS-CoV-2 at 85 health systems between March 1, 2020, and January 31, 2021.

EXPOSURES

Diagnoses for 26 cardiovascular conditions between January 1, 2015, and December 31, 2019 (before infection with SARS-CoV-2).

MAIN OUTCOMES AND MEASURES

The main outcome was severe COVID-19, defined as need for supplemental oxygen or in-hospital death. Mixed-effects, random intercept logistic regression modeling assessed the significance and magnitude of associations between 26 cardiovascular conditions and COVID-19 severity. Multiple comparison adjustment was performed using the Benjamini-Hochberg false discovery rate procedure.

RESULTS

The study comprised 171 416 pediatric patients; the median age was 8 years (IQR, 2-14 years), and 50.28% were male. Of these patients, 17 065 (9.96%) had severe COVID-19. The random intercept model showed that the following cardiovascular conditions were associated with severe COVID-19: cardiac arrest (odds ratio [OR], 9.92; 95% CI, 6.93-14.20), cardiogenic shock (OR, 3.07; 95% CI, 1.90-4.96), heart surgery (OR, 3.04; 95% CI, 2.26-4.08), cardiopulmonary disease (OR, 1.91; 95% CI, 1.56-2.34), heart failure (OR, 1.82; 95% CI, 1.46-2.26), hypotension (OR, 1.57; 95% CI, 1.38-1.79), nontraumatic cerebral hemorrhage (OR, 1.54; 95% CI, 1.24-1.91), pericarditis (OR, 1.50; 95% CI, 1.17-1.94), simple biventricular defects (OR, 1.45; 95% CI, 1.29-1.62), venous embolism and thrombosis (OR, 1.39; 95% CI, 1.11-1.73), other hypertensive disorders (OR, 1.34; 95% CI, 1.09-1.63), complex biventricular defects (OR, 1.33; 95% CI, 1.14-1.54), and essential primary hypertension (OR, 1.22; 95% CI, 1.08-1.38). Furthermore, 194 of 258 patients (75.19%) with a history of cardiac arrest were younger than 12 years.

CONCLUSIONS AND RELEVANCE

The findings suggest that some previous or preexisting cardiovascular conditions are associated with increased severity of COVID-19 among pediatric patients in the US and that morbidity may be increased among individuals children younger than 12 years with previous cardiac arrest.

Asymptomatic or mildly symptomatic COVID-19 patients with craniomaxillofacial injuries have an increase risk of surgical site infection

The aim of this paper was to evaluate the association between ‘asymptomatic or mildly symptomatic’ severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection (AS/MS-COVID) and surgical site infection (SSI) after repair of craniomaxillofacial injury (CMFI). Using a case-control study design with a match ratio of 1:4, we enrolled a cohort of AS/MS-COVID cases with immediately treated CMFI during a one-year period. The main predictor variable was SARS-CoV-2 infection (yes/no), and the outcome of interest was SSI (yes/no). The other variables were demographic, clinical, and operative. Appropriate statistics were computed, and p<0.05 was considered statistically significant. The study group comprised 257 cases (28.8% female; 13.2% aged ≥ 60 years; 10.5% with fractures; 39.7% with involvement of nasal/oral/orbital tissue [viral reservoir organs, VROs]; 81.3% with blunt trauma; 19.1% developed an SSI [vs 6.8% in the control group]) with a mean (SD) age of 39.8 (16.6) years (range 19–87). There was a significant relation between SARS-CoV-2 infection and SSI events (p<0.0001; odds ratio 3.22; 95% confidence interval 2.17 to 4.78). On subgroup analysis, SSIs significantly increased with age ≥ 60 years, presence and treatment of fracture, contact with VROs, and prolonged antibiotic use (PAU). However, multivariate logistic regression analysis confirmed a positive effect only from old age, contact with VROs, and PAU (relative risk = 1.56, 2.52, and 2.03, respectively; r = 0.49; p = 0.0001). There was a significant 2.8-fold increase in SSIs among AS/MS-COVID cases, especially in those aged ≥ 60 years, or those with injuries to VROs, or both, who therefore required PAU.

Neutralizing the free radicals could alleviate the disease severity following an infection by positive strand RNA viruses

Free radical release due to oxidative stress is gaining importance in the field of viral pathogenesis. Recent studies suggest the involvement of oxidative stress and ROS levels in regulating disease virulence during RNA virus infection. Most of the RNA virus infections lead to vascular dysfunction and disease severity. However, the biology of free radicals in maintaining vascular endothelium integrity is not completely understood. In the present review, we discuss some of the common features in positive-strand RNA virus infections such as dengue and SARS-CoV-2 and suggest that anti-oxidant therapy could pave the way to develop therapeutic strategies in combating emerging and re-emerging RNA viruses.

Do the Successive Waves of SARS-CoV-2, Vaccination Status and Place of Infection Influence the Clinical Picture and COVID-19 Severity among Patients with Persistent Clinical Symptoms? The Retrospective Study of Patients from the STOP-COVID Registry of the PoLoCOV-Study

The severity of ailments caused by SARS-CoV-2 varies and the clinical picture has already evolved during the pandemic, complicating diagnostics. In Poland, no study has been performed to assess the clinical picture of patients across the successive pandemic waves. The aim of the study was to present the characteristics of patients who present to medical center because of persistent symptoms after COVID-19, and to study differences between hospitalized/non-hospitalized, vaccinated/non-vaccinated individuals and between different waves in Poland. This is a retrospective study evaluating the clinical presentation of COVID-19 patients from the STOP-COVID registry of the PoLoCOV-Study. This registry includes patients who present to the medical center because of persistent clinical symptoms after the isolation. The patients' data were obtained from individuals who suffered from COVID-19 between September 2020 and December 2021.The patients were divided into groups according to the infection rate increase pattern (II/III/IV pandemic wave), status of vaccination and place of isolation. Regardless of the pandemic wave, the patients' most commonly reported weaknesses were a cough and a headache. The arterial hypertension and hyperlipidemia were the most frequent concomitant chronic conditions. Hospitalized patients more often reported weakness or a cough while home-isolated patients were more likely to have rhinitis or a headache. Patients who completed the vaccination course showed a shorter duration of clinical symptoms and a lower mean number of symptoms. Additionally, vaccinated individuals reported less taste and/or olfactory dysfunction than unvaccinated individuals. To conclude, the persistence of the pandemic has resulted in significant changes observed in the clinical picture. Successive waves caused deterioration in the subjective assessment of the disease severity. A cough seemed to occur more frequently in the later pandemic waves.

Investigating expressed RNA variants that are related to disease severity in SARS-CoV-2-infected patients with mild-to-severe disease

Background

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) continues to be a significant public health challenge globally. SARS-CoV-2 is a novel virus, and the understanding of what constitutes expressed RNAseq variants in healthy, convalescent, severe, moderate, and those admitted to the intensive care unit (ICU) is yet to be presented. We characterize the different expressed RNAseq variants in healthy, severe, moderate, ICU, and convalescent individuals.

Materials and methods

The bulk RNA sequencing data with identifier PRJNA639275 were downloaded from Sequence Reads Archive (SRA). The individuals were divided into: (1) healthy, n = 34, moderate, n = 8, convalescent, n = 2, severe, n = 16, and ICU, n = 8. Fastqc version 0.11.9 and Cutadapt version 3.7 were used to assess the read quality and perform adapter trimming, respectively. STAR was used to align reads to the reference genome, and GATK best practice was followed to call variants using the rnavar pipeline, part of the nf-core pipelines.

Results

Our analysis demonstrated that different sets of unique RNAseq variants characterize convalescent, moderate, severe, and those admitted to the ICU. The data show that the individuals who recover from SARS-CoV-2 infection have the same set of expressed variants as the healthy controls. We showed that the healthy and SARS-CoV-2-infected individuals display different sets of expressed variants characteristic of the patient phenotype.

Conclusion

The individuals with severe, moderate, those admitted to the ICU, and convalescent display a unique set of variants. The findings in this study will inform the test kit development and SARS-CoV-2 patients classification to enhance the management and control of SARS-CoV-2 infection in our population.

Anti-Inflammatory Effects and Decreased Formation of Neutrophil Extracellular Traps by Enoxaparin in COVID-19 Patients

Neutrophil Extracellular Traps (NETs) are a contributing factor of vascular thrombosis and alveolar damage in COVID-19 patients. As enoxaparin is currently used to inhibit vascular thrombosis, this study aimed to investigate whether enoxaparin also reduced inflammation and NETs in COVID-19 patients. Patients with COVID-19 infection were classified into three groups: mild, moderate, and severe (n = 10 for all groups). Plasma was collected from patients and healthy donors (n = 10). Neutrophils isolated from healthy controls were incubated with COVID-19 or healthy plasma, and with or without enoxaparin pretreatment in vitro. Neutrophils and plasma isolated from patients treated with enoxaparin were also investigated. The levels of inflammatory cytokines and NET products such as dsDNA, NE, MPO−DNA and Histone−DNA complexes in plasma and supernatants were measured using immunofluorescence staining and ELISA kits. The expression of inflammatory signaling genes by neutrophils (RELA, SYK, ERK and PKC) was measured using real-time qPCR. The levels of NET products were elevated in the plasma of COVID-19 patients, particularly in the severe group (p < 0.01). Moreover, plasma from the severe group enhanced NET formation (p < 0.01) from neutrophils in vitro. Enoxaparin pretreatment in vitro decreased plasma-induced NETs in a dose-dependent manner and down-regulated the expression of inflammatory genes (p < 0.05). Patients treated with prophylactic enoxaparin showed lower inflammatory cytokine levels and expression of inflammatory genes (p < 0.05). Increased NETs were associated with the severity of COVID-19 infection, particularly in patients with severe pneumonia, and could be used as biomarkers to assess disease severity. Enoxaparin pretreatment inhibited NETs and reduced the expression of inflammatory cytokines, and these effects mostly persisted in patients treated with prophylactic enoxaparin.

Intestinal Ischemia: Unusual but Fearsome Complication of COVID-19 Infection

The pathophysiology of gastrointestinal damage in coronavirus disease (COVID-19) is probably multifactorial. It is not clear whether the etiology of intestinal ischemia may be directly related to viral replication or may result from hyper-coagulability following SARS-CoV-2 infection.To confirm a pathogenic role of COVID-19, we retrospectively investigated the presence of SARS-CoV-2 virus in the ischemic bowel of five COVID-19 patients undergoing emergency surgery for intestinal ischemia in the period of March 2020-May 2021. Immunohistochemical positivity with weak intensity was observed in four out of five cases, but only one case was strongly positive both at immunohistochemistry and at molecular analysis. The histological alterations in the intestinal tissue samples showed similarity with the well-known alterations described in typical targetorgans of the virus (e.g., the lung). This observation suggests a similar mechanism of action of the virus. Further larger studies are, thus, required to confirm this preliminary finding. Clinicians should carefully monitor all COVID-19 patients for the possible presence of a SARS-CoV-2 intestinal infection, a potential cause of ischemia and bowel perforation.

The Influence of Sex, Gender, and Age on COVID-19 Data in the Piedmont Region (Northwest Italy): The Virus Prefers Men

Several important sex and gender differences in the clinical manifestation of diseases have been known for a long time but are still underestimated. The infectious Coronavirus 2019 disease pandemic has provided evidence of the importance of a sex and gender-based approach; it mainly affected men with worse symptomatology due to a different immune system, which is stronger in women, and to the Angiotensin-converting enzyme 2 and Transmembrane protease serine 2 roles which are differently expressed among the sexes. Additionally, women are more inclined to maintain social distance and smoke less. Analysis of data on the infectious Coronavirus 2019 disease testing from people admitted to the Amedeo di Savoia Hospital, a regional referral center for infectious diseases, has been applied to the whole of 2020 data (254,640 records). A high percentage of data in the dataset was not suitable due to a lack of information or entering errors. Among the suitable samples, records have been analyzed for positive/negative outcomes, matching records for unique subjects (N = 123,542), to evaluate individual recurrence of testing. Data are presented in age and sex-disaggregated ways. Analyses of the suitable sample also concerned the relation between testing and hospital admission motivation and symptoms. Our analysis indicated that a sex and gender-based approach is mandatory for patients and the National Health System’s sustainability.

SARS-CoV-2: An Overview of the Genetic Profile and Vaccine Effectiveness of the Five Variants of Concern

With the onset of the COVID-19 pandemic, enormous efforts have been made to understand the genus SARS-CoV-2. Due to the high rate of global transmission, mutations in the viral genome were inevitable. A full understanding of the viral genome and its possible changes represents one of the crucial aspects of pandemic management. Structural protein S plays an important role in the pathogenicity of SARS-CoV-2, mutations occurring at this level leading to viral forms with increased affinity for ACE2 receptors, higher transmissibility and infectivity, resistance to neutralizing antibodies and immune escape, increasing the risk of infection and disease severity. Thus, five variants of concern are currently being discussed, Alpha, Beta, Gamma, Delta and Omicron. In the present review, a comprehensive summary of the following critical aspects regarding SARS-CoV-2 has been made: (i) the genomic characteristics of SARS-CoV-2; (ii) the pathological mechanism of transmission, penetration into the cell and action on specific receptors; (iii) mutations in the SARS-CoV-2 genome; and (iv) possible implications of mutations in diagnosis, treatment, and vaccination.

Bioavailability Enhancement of Cepharanthine via Pulmonary Administration in Rats and Its Therapeutic Potential for Pulmonary Fibrosis Associated with COVID-19 Infection

Cepharanthine (CEP) has excellent anti-SARS-CoV-2 properties, indicating its favorable potential for COVID-19 treatment. However, its application is challenged by its poor dissolubility and oral bioavailability. The present study aimed to improve the bioavailability of CEP by optimizing its solubility and through a pulmonary delivery method, which improved its bioavailability by five times when compared to that through the oral delivery method (68.07% vs. 13.15%). An ultra-performance liquid chromatography tandem-mass spectrometry (UPLC-MS/MS) method for quantification of CEP in rat plasma was developed and validated to support the bioavailability and pharmacokinetic studies. In addition, pulmonary fibrosis was recognized as a sequela of COVID-19 infection, warranting further evaluation of the therapeutic potential of CEP on a rat lung fibrosis model. The antifibrotic effect was assessed by analysis of lung index and histopathological examination, detection of transforming growth factor (TGF)-β1, interleukin-6 (IL-6), α-smooth muscle actin (α-SMA), and hydroxyproline level in serum or lung tissues. Our data demonstrated that CEP could significantly alleviate bleomycin (BLM)-induced collagen accumulation and inflammation, thereby exerting protective effects against pulmonary fibrosis. Our results provide evidence supporting the hypothesis that pulmonary delivery CEP may be a promising therapy for pulmonary fibrosis associated with COVID-19 infection.

Multisystem Inflammatory Syndrome and Autoimmune Diseases Following COVID-19: Molecular Mechanisms and Therapeutic Opportunities

Coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome-coronavirus 2 (SARS-CoV-2), has led to huge concern worldwide. Some SARS-CoV-2 infected patients may experience post–COVID-19 complications such as multisystem inflammatory syndrome, defined by symptoms including fever and elevated inflammatory markers (such as elevation of C reactive protein (CRP), erythrocyte sedimentation rate, fibrinogen, procalcitonin test, D-dimer, ferritin, lactate dehydrogenase or IL-6, presence of neutrophilia, lymphopenia, decreased albumin, and multiple organ dysfunction). Post–COVID-19 complications may also manifest as autoimmune diseases such as Guillain-Barré syndrome and systemic lupus erythematosus. Signaling disorders, increased inflammatory cytokines secretion, corticosteroid use to treat COVID-19 patients, or impaired immune responses are suggested causes of autoimmune diseases in these patients. In this review, we discuss the molecular and pathophysiological mechanisms and therapeutic opportunities for multisystem inflammatory syndrome and autoimmune diseases following SARS-CoV-2 infection with the aim to provide a clear view for health care providers and researchers.

CVD and COVID-19: Emerging Roles of Cardiac Fibroblasts and Myofibroblasts

Cardiovascular disease (CVD) is the leading cause of death worldwide. Current data suggest that patients with cardiovascular diseases experience more serious complications with coronavirus disease-19 (COVID-19) than those without CVD. In addition, severe COVID-19 appears to cause acute cardiac injury, as well as long-term adverse remodeling of heart tissue. Cardiac fibroblasts and myofibroblasts, being crucial in response to injury, may play a pivotal role in both contributing to and healing COVID-19-induced cardiac injury. The role of cardiac myofibroblasts in cardiac fibrosis has been well-established in the literature for decades. However, with the emergence of the novel coronavirus SARS-CoV-2, new cardiac complications are arising. Bursts of inflammatory cytokines and upregulation of TGF-β1 and angiotensin (AngII) are common in severe COVID-19 patients. Cytokines, TGF-β1, and Ang II can induce cardiac fibroblast differentiation, potentially leading to fibrosis. This review details the key information concerning the role of cardiac myofibroblasts in CVD and COVID-19 complications. Additionally, new factors including controlling ACE2 expression and microRNA regulation are explored as promising treatments for both COVID-19 and CVD. Further understanding of this topic may provide insight into the long-term cardiac manifestations of the COVID-19 pandemic and ways to mitigate its negative effects.

The COVID-19 pandemic - what have urologists learned?

On 11 March 2020, the WHO declared the coronavirus disease 2019 (COVID-19) outbreak a pandemic and COVID-19 emerged as one of the biggest challenges in public health and economy in the twenty-first century. The respiratory tract has been the centre of attention, but COVID-19-associated complications affecting the genitourinary tract are reported frequently, raising concerns about possible long-term damage in these organs. The angiotensin-converting enzyme 2 (ACE2) receptor, which has a central role in severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) invasion, is highly expressed in the genitourinary tract, indicating that these organs could be at a high risk of cell damage. The detection of SARS-CoV-2 in urine and semen is very rare; however, COVID-19 can manifest through urological symptoms and complications, including acute kidney injury (AKI), which is associated with poor survival, severe structural changes in testes and impairment of spermatogenesis, and hormonal imbalances (mostly secondary hypogonadism). The effect of altered total testosterone levels or androgen deprivation therapy on survival of patients with COVID-19 was intensively debated at the beginning of the pandemic; however, androgen inhibition did not show any effect in preventing or treating COVID-19 in a clinical study. Thus, urologists have a crucial role in detecting and managing damage of the genitourinary tract caused by COVID-19.

Receptor binding domain of SARS-CoV-2 is a functional αv-integrin agonist

Among the novel mutations distinguishing SARS-CoV-2 from similar respiratory coronaviruses is a K403R substitution in the receptor-binding domain (RBD) of the viral spike (S) protein within its S1 region. This amino acid substitution occurs near the angiotensin-converting enzyme 2 (ACE2)-binding interface and gives rise to a canonical RGD adhesion motif that is often found in native extracellular matrix proteins, including fibronectin. In the present study, the ability of recombinant S1-RBD to bind to cell surface integrins and trigger downstream signaling pathways was assessed and compared to RGD-containing, integrin-binding fragments of fibronectin. S1-RBD supported adhesion of both fibronectin-null mouse embryonic fibroblasts as well as primary human small airway epithelial cells. Cell adhesion to S1-RBD was cation- and RGD-dependent, and was inhibited by blocking antibodies against α v and β 3 , but not α 5 or β 1 , integrins. Similarly, direct binding of S1-RBD to recombinant human α v β 3 and α v β 6 integrins, but not α 5 β 1 integrins, was observed by surface plasmon resonance. Adhesion to S1-RBD initiated cell spreading, focal adhesion formation, and actin stress fiber organization to a similar extent as fibronectin. Moreover, S1-RBD stimulated tyrosine phosphorylation of the adhesion mediators FAK, Src, and paxillin, Akt activation, and supported cell proliferation. Together, these data demonstrate that the RGD sequence within S1-RBD can function as an α v -selective integrin agonist. This study provides evidence that cell surface α v -containing integrins can respond functionally to spike protein and raise the possibility that S1-mediated dysregulation of ECM dynamics may contribute to the pathogenesis and/or post-acute sequelae of SARS-CoV-2 infection.

Aging versus youth: Endocrine aspects of vulnerability for COVID-19

Coronavirus Disease 2019 (COVID-19) is characterized with a wide range of clinical presentations from asymptomatic to severe disease. In patients with severe disease, the main causes of mortality have been acute respiratory distress syndrome, cytokine storm and thrombotic events. Although all factors that may be associated with disease severity are not yet clear, older age remains a leading risk factor. While age-related immune changes may be at the bottom of severe course of COVID-19, age-related hormonal changes have considerable importance due to their interactions with these immune alterations, and also with endothelial dysfunction and comorbid cardiometabolic disorders. This review aims to provide the current scientific evidence on the pathogenetic mechanisms underlying the pathway to severe COVID-19, from a collaborative perspective of age-related immune and hormonal changes together, in accordance with the clinical knowledge acquired thus far.

Immunopathological changes, complications, sequelae and immunological memory in COVID-19 patients

Confirmed SARS-CoV-2-caused disease (COVID-19) cases have reached 275.65 million worldwide. Although the majority of COVID-19 patients present mild to moderate symptoms, some have severe complications including death. We first reviewed the pathogenesis on ACE2, a binding receptor of SARS-CoV-2 expressed in multiple organs, and prevalent multinucleate syncytia in the lung tissues of COVID-19 patients. Then, we evaluated the pathological, immunological changes and sequelae in the major organs. Finally, we reviewed the immunological memory after SARS-CoV-2 infection and vaccination. The binding of SARS-Cov-2 to ACE2 receptor results in reduced ACE2 protein levels, which may lead to elevated susceptibility to inflammation, cell death, organ failure, and potentially severe illness. These damages increase the risk of health problems over a long period, which result in many complications. The complications in multiple organs lead to the increased risk of long-term health problems that require additional attention. A multidisciplinary care team is necessary for further management and recovery of the COVID-19 survivors. Many COVID-19 patients will probably make antibodies against SARS-CoV-2 virus for most of their lives, and the immunity against reinfection would last for 3-61 months.

Dysregulation in erythrocyte dynamics caused by SARS-CoV-2 infection: possible role in shuffling the homeostatic puzzle during COVID-19

Introduction

The evolving COVID-19 pandemic became a hallmark in human history, not only by changing lifestyles, but also by enriching scientific knowledge on viral infection and its consequences.

Objective

Although the management of cardiorespiratory changes is pivotal to a favorable prognosis during severe clinical findings, dysregulation of other systems caused by SARS-CoV-2 infection may imbalance erythrocyte dynamics, such as a bidirectional positive feedback loop pathophysiology.

Method and Results

Recent evidence shows that SARS-CoV-2 is capable of affecting the genetics and dynamics of erythrocytes and this coexists with a non-homeostatic function of cardiovascular, respiratory and renal systems during COVID-19. In hypothesis, SARS-CoV-2-induced systematical alterations of erythrocytes dynamics would constitute a setpoint for COVID-19-related multiple organ failure syndrome and death.

Conclusion

The present review covers the most frequent erythrocyte-related non-homeostatic findings during COVID-19 capable of providing mechanistic clues of SARS-CoV-2-induced infection and inspiring therapeutic-oriented scientific evidence.

Post-COVID-19 Liver Injury: Comprehensive Imaging With Multiparametric Ultrasound

OBJECTIVES

This study aimed to define patterns of liver injury after severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection using multiparametric ultrasound (mpUS) in a variable patient population with differing severities of COVID-19.

METHODS

Ninety patients were enrolled into the study: 56 had SARS-CoV-2 3-9 months prior to enrolment; 34 served as a clinically healthy control group. All patients underwent an mpUS evaluation of the liver (elastography, dispersion and attenuation imaging). Seventy-six patients had abdominal magnetic resonance (MR) and noncontrast enhanced thoracic computed tomography (CT) scans performed at the same day. All patients were screened for biochemical markers of liver injury.

RESULTS

Liver elasticity, viscosity, and steatosis values were significantly altered in patients after COVID-19, with particularly higher fibrosis scores compared to the control group (P < .001). Increased biochemical markers of liver injury correlated with changes in mpUS (P < .05), but not with findings on CT or MR findings. Seventeen of 34 hospitalized patients had a moderate or severe course of the disease course with more pronounced changes in mpUS. Increased body mass index was found to influence liver injury and correlated with more severe forms of COVID-19 (P < .001).

CONCLUSIONS

COVID-19 can cause liver injury observable using mpUS. More severe forms of COVID-19 and patient obesity are related to increased values of liver damage observed. In comparison to MRI and CT, mpUS appears to be more sensitive to involvement of liver parenchyma. Further research is warranted to establish this promising method for evaluating post-COVID-19 liver involvement in the aftermath of the pandemic.

Testosterone as a Biomarker of Adverse Clinical Outcomes in SARS-CoV-2 Pneumonia

Background: The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) may affect testicles. Lower testosterone levels have been associated with worse clinical outcomes and higher mortality. Our objective was to evaluate the hypothalamic−pituitary−gonadal axis of men admitted with SARS-CoV-2 pneumonia and its link with the pneumonia-treatment intensification. Short-term changes in hormonal parameters were also assessed. Methods: Men admitted with SARS-CoV-2 pneumonia were recruited in two different hospitals in Piedmont, Italy. In all patients, the assessment of total testosterone (TT), calculated free testosterone (cFT), gonadotropins, inhibin B (InhB), and other biochemical evaluations were performed at admission (T0) and before discharge (T1). Through a review of medical records, clinical history was recorded, including data on pneumonia severity. Results: Thirty-five men (median age 64 [58−74] years) were recruited. Lower TT and cFT levels at T0 were associated with CPAP therapy (p = 0.045 and 0.028, respectively), even after adjusting for age and PaO2/FIO2 ratio in a multivariable analysis. In those discharged alive, lower TT and cFT levels were associated with longer hospital stay (p < 0.01). TT, cFT, and InhB were below the normal range at T0 and significantly increased at T1 (TT 1.98 [1.30−2.72] vs. 2.53 [1.28−3.37] ng/mL, p = 0.038; cFT (0.0441 [0.0256−0.0742] vs. 0.0702 [0.0314−0.0778] ng/mL, p = 0.046; InhB 60.75 [25.35−88.02] vs. 77.05 [51.15−134.50], p < 0.01). Conclusions: Both TT and cFT levels are associated with adverse clinical outcomes in men admitted with SARS-CoV-2 pneumonia. As TT, cFT and InhB levels increase before discharge, short-term functional recovery of steroidogenesis and an indirect improvement of spermatozoa functional status could be hypothesized.

The Role of Vitamin D in Supporting Health in the COVID-19 Era

The genomic activity of vitamin D is associated with metabolic effects, and the hormone has a strong impact on several physiological functions and, therefore, on health. Among its renowned functions, vitamin D is an immunomodulator and a molecule with an anti-inflammatory effect, and, recently, it has been much studied in relation to its response against viral infections, especially against COVID-19. This review aims to take stock of the correlation studies between vitamin D deficiency and increased risks of severe COVID-19 disease and, similarly, between vitamin D deficiency and acute respiratory distress syndrome. Based on this evidence, supplementation with vitamin D has been tested in clinical trials, and the results are discussed. Finally, this study includes a biochemical analysis on the effects of vitamin D in the body's defense mechanisms against viral infection. In particular, the antioxidant and anti-inflammatory functions are considered in relation to energy metabolism, and the potential, beneficial effect of vitamin D in COVID-19 is described, with discussion of its influence on different biochemical pathways. The proposed, broader view of vitamin D activity could support a better-integrated approach in supplementation strategies against severe COVID-19, which could be valuable in a near future of living with an infection becoming endemic.

Detailed videocapillaroscopic microvascular changes detectable in adult COVID-19 survivors

Objective

COVID-19 is a multisystem disease that causes endothelial dysfunction and organ damage. Aim of the study was to evaluate the microvascular status in COVID-19 survivors with past different disease severity, in comparison with age and sex-matched primary Raynaud's phenomenon (PRP) patients and control subjects (CNT), including possible effects of concomitant therapies.

Methods

Sixty-one COVID-19 survivors (mean age 58 ± 13 years, mean days from disease onset 126 ± 53 and mean days from recovery 104 ± 53), thirty-one PRP patients (mean age 59 ± 15 years, mean disease duration 11 ± 10 years) and thirty CNT (mean age 58 ± 13 years) underwent nailfold videocapillaroscopy (NVC) examination. The following capillaroscopic parameters were searched and scored (0–3): dilated capillaries, giant capillaries, isolated microhemorrhages, capillary ramifications (angiogenesis) and capillary number, including absolute capillary number per linear millimeter at the nailfold bed.

Results

The mean nailfold capillary number per linear millimeter was significantly lower in COVID-19 survivors when compared with PRP patients and CNT (univariate and multivariate analysis p < 0.001). On the contrary, COVID-19 survivors showed significantly less isolated microhemorrhages than PRP patients and CNT (univariate and multivariate analysis, p = 0.005 and p = 0.012, respectively). No statistically significant difference was observed between COVID-19 survivors and control groups concerning the frequency of dilated capillaries and capillary ramifications. COVID-19 selective therapies showed a promising trend on preserving capillary loss and deserving further investigations.

Conclusions

SARS-CoV-2 seems to mainly induce a significant loss of capillaries in COVID-19 survivors at detailed NVC analysis in comparison to controls. The presence of a significant reduced score for isolated microhaemorrhages in COVID-19 survivors deserves further analysis.

Neuromuscular rehabilitation interventions and COVID-19 management in a case of incomplete paraplegia with neurogenic bladder, post T3-T5 ependymoma

Spinal ependymomas are a group of mostly slow-growing tumors that can cause non-traumatic spinal cord injury with insidious clinical symptomatology ranging from neck or back pain to as-sociated sensory-motor impairment. Due to their neurological and systemic frailty, patients with spinal cord injury might be especially vulnerable to the effects of SARS-CoV-2 infection and the resulting respiratory impairment. CASE PRESENTATION: We present the case of a 66 year old women admitted in our Neuromuscular Rehabilitation Clinic Division for severe in-complete paraplegia and neurogenic bladder. She was previously diagnosed in the Neurosurgi-cal Ward with a thoracic grade II (classic) ependymoma and underwent a gross tumor resection. During the neurorehabilitation program the patient was diagnosed with COVID-19. The multi-drug related treatments were associated with supportive oxygen therapy and neuromuscular and respiratory rehabilitation techniques. RESULTS: Despite of the patient’s favorable rehabili-tation, consisting of walking abilities with support in a walking frame on short distances, her prognosis may be worsened by resting neurogenic bladder symptoms. COVID-19 has led to im-portant acute respiratory morbidity in our patient, regardless of the mild course of the disease, and might further cause a post-infectious respiratory impairment. ONCLUSION: Spinal cord in-jury remains a life-long condition and emphasizes the necessity of supporting the affected pati-ents on the long run. Keywords: students, balance, postural stability, physical exercise, progress, motor skills

Does air pollution explain COVID-19 fatality and mortality rates? A multi-city study in São Paulo state, Brazil

Since air pollution compromise the respiratory system and COVID-19 disease is caused by a respiratory virus, it is expected that air pollution plays an important role in the current COVID-19 pandemic. Exploratory studies have observed positive associations between air pollution and COVID-19 cases, deaths, fatality, and mortality rate. However, no study focused on Brazil, one of the most affected countries by the pandemic. Thus, this study aimed to understand how long-term exposure to PM₁₀, PM_2.5, and NO₂ contributed to COVID-19 fatality and mortality rates in São Paulo state in 2020. Air quality data between 2015 and 2019 in 64 monitoring stations within 36 municipalities were considered. The COVID-19 fatality was calculated considering cases and deaths from the government's official data and the mortality rate was calculated considering the 2020 population. Linear regression models were well-fitted for PM_2.5 concentration and fatality (R² = 0.416; p = 0.003), NO₂ concentration and fatality (R² = 0.232; p = 0.005), and NO₂ concentration and mortality (R² = 0.273; p = 0.002). This study corroborates other authors' findings and enriches the discussion for having considered a longer time series to represent long-term exposure to the pollutants and for having considered one of the regions with the highest incidence of COVID-19 in the world. Thus, it reinforces measures to reduce the concentration of air pollutants which are essential for public health and will increase the chance to survive in future respiratory disease epidemics.