Body Localization of ACE-2: On the Trail of the Keyhole of SARS-CoV-2

Angiotensin converting enzyme 2 in patients with sepsis associate with comorbidities but neither with mortality nor with organ failure

High levels of circulating angiotensin converting enzyme 2 (ACE2) are associated with several chronic diseases and mortality risk. Less is known about the prognostic value of ACE2 in patients with sepsis. In the present study, we aimed to investigate the association between plasma ACE2 levels on admission to the ED and 28-day mortality, organ failure, and level of care in a prospectively recruited observational study sample. Six hundred patients with sepsis admitted to the emergency in Malmö 2013-2015 were included in the analysis. Uni- and multivariable binary logistic regression was conducted to investigate the association between ACE2 and 28-day mortality, organ failure, and level of care. Plasma ACE2 levels were increased in patients with male sex, high age, and comorbidities, including diabetes, cardiovascular disease, and cancer. Plasma ACE2 levels associated with hospitalization and intermediate care unit stay in univariate but not multivariate analysis. Plasma ACE2 did neither associate with 28-day mortality, OR 1.19 (95% CI 0.86-1.65, p = 0.29), nor with organ failure, OR 1.08 (95% CI 0.73-1.56. p = 0.72). Future studies investigating the dynamics of circulating ACE2 levels in patients with sepsis longitudinally are warranted.

SARS-CoV-2 Entry Factors ACE2, TMPRSS2 and FURIN in Salivary Glands From Primary Sjögren's Disease

BACKGROUND

Salivary glands are the reservoir for severe acute respiratory syndrome Coronavirus 2 virus (SARS-CoV-2). It is known that SARS-CoV-2 uses angiotensin-converting enzyme 2 (ACE2), transmembrane serine protease 2 (TMPRSS2) and FURIN to infect cells. Salivary glands express these entry factors, and it is unclear if these molecules are expressed in salivary glands from primary Sjögren's disease (pSjD). This study assessed ACE2, TMPRSS2, and FURIN gene expression by RT-qPCR in pSjD compared to normal salivary gland and pleomorphic adenoma.

METHODS

An integrated study of ACE2, TMPRSS2, and FURIN gene expression across pSjD, pleomorphic adenoma, and normal salivary gland by RT-pPCR was performed. The association between gene expression and clinicopathological data was also examined.

RESULTS

pSjD showed ACE2 upregulation compared with normal salivary gland and pleomorphic adenoma (p < 0.05). TMPRSS2 and FURIN mRNA levels are also higher in pSjD compared to pleomorphic adenoma (p < 0.05). ACE2 expression levels were associated with anti-SSA/SSB positivity (p < 0.05). A strong correlation was observed between TMPRSS2 and FURIN in pSjD (r = 0.768; p = 0.001).

CONCLUSION

Our analysis revealed a high expression of ACE2 in pSjD. ACE2, TMPRSS2, and FURIN mRNA levels are increased in pSjD in comparison to pleomorphic adenomas. Neither ACE2, TMPRSS2, nor furin was consistently associated with SARS-CoV-2 positivity in pSjD. These findings may guide future investigations on the effects of SARS-CoV-2 in a subset of salivary gland diseases.

Impaired Cardiovascular Hemodynamics in Patients Hospitalized with COVID-19 Pneumonia

Background: SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2) infection may be associated with impaired cardiac function, especially in severe cases requiring hospitalization. Impedance cardiography (ICG) is a noninvasive method for assessing cardiac function. It could be useful for the early detection of hemodynamic dysfunction, particularly in patients with a severe course of COVID-19. Aim: This study aimed to analyze and compare the hemodynamic profiles of patients hospitalized with SARS-CoV-2-induced pneumonia to those of a control group. Methods: This prospective, observational, clinical study included 30 hospitalized patients (both men and women, mean age: 48 years) diagnosed with COVID-19 pneumonia (COVID group). Their data were compared to those of a retrospective control group (CG). The study participants were propensity score-matched based on clinical characteristics, including age, blood pressure (BP), and body mass index (BMI). ICG measurements of hemodynamic profiles were performed using a Niccomo device and included heart rate (HR), stroke volume index (SI), cardiac index (CI), velocity index (VI), acceleration index (ACI), Heather index (HI), systemic vascular resistance index (SVRI), and thoracic fluid content (TFC). Results: Patients with COVID-19 showed significantly higher HR (p < 0.0001) and SVRI (p = 0.0003) and lower values for several cardiac function parameters, including SI (p < 0.0001), VI (p < 0.0001), ACI (p = 0.004), and HI (p < 0.0001). Additionally, 11 patients (37%) in the COVID group had a low SI (<35 mL/m2), compared to only 1 patient (3%) in the control group (p < 0.0001). A statistically significant difference in left ventricular ejection fraction (LVEF) was also observed (p < 0.0001), although absolute values remained within the normal range. Conclusions: SARS-CoV-2 infection negatively affects the cardiovascular system, leading to impaired heart function even in low-risk patients. Impedance cardiography may serve as a simple, noninvasive tool for identifying individuals with cardiac dysfunction following COVID-19 pneumonia.

Does COVID-19 Cause Non-Dıpper Hypertension?

Coronavirus disease 2019 (COVID-19) remains a health problem worldwide. The present study aimed to investigate the effect of blood pressure (BP) on the circadian pattern and prevalence of new-onset non-dipper hypertension in the post-COVID period in patients with known hypertension. This prospective single-center study included 722 patients hospitalized for COVID-19 infection. Ambulatory BP (ABP) data were collected during their initial hospitalization. The ABP data were reassessed 1 month after the patients were discharged. The results were compared with a healthy control group with known hypertension but without COVID-19 infection. After exclusion criteria were applied, the study included 187 patients with COVID-19 and 136 healthy hypertensive controls. Post-COVID ABP showed that patients with COVID-19 had significantly higher mean 24-h systolic and diastolic BP, mean nighttime systolic and diastolic BP, and mean daytime diastolic BP than the control group. In addition, new-onset non-dipper hypertension was significantly higher in patients with COVID-19. This study demonstrated for the first time that the circadian pattern is disturbed and a non-dipper pattern develops in individuals with known hypertension during the post-COVID period.

Chronic Hepatitis B and COVID-19 Clinical Outcomes in the United States: A Multisite Retrospective Cohort Study

Background

There is conflicting evidence regarding the impact of chronic hepatitis B virus (HBV) on SARS-CoV-2 outcomes. Additionally, the impact of SARS-CoV-2 vaccination and variant periods on outcomes in HBV/SARS-CoV-2 coinfection remain unexplored.

Methods

We utilized the TriNetX database to compare adults with HBV/SARS-CoV-2 (vs SARS-CoV-2 alone) across 97 US healthcare systems from 2020 to 2023. We assessed the odds of all inpatient hospitalizations, intensive care unit admissions, mechanical ventilation, 30-day, 90-day, and overall mortality. In sensitivity analyses, we excluded HIV, hepatitis C virus, and transplant cases and stratified the HBV/SARS-CoV-2 cohort by cirrhosis status. We applied propensity score matching to address confounding and reported odds ratios (OR) with 95% confidence intervals (CI).

Results

Of 4 206 774 individuals with SARS-CoV-2, about 0.2% (8293) were HBV/SARS-CoV-2. Individuals with HBV/SARS-CoV-2 (vs SARS-CoV-2 alone) had higher odds of intensive care unit admissions (OR, 1.18; 95% CI, 1.02-1.36), 90-day (OR, 1.22; 95% CI, 1.01-1.41) and overall mortality (OR, 1.18; 95% CI, 1.06-1.33). In sensitivity analyses, those with HBV/SARS-CoV-2 and cirrhosis had a 2.0- to 2.50-fold higher odds of adverse outcomes. Notably, even individuals with HBV/SARS-CoV-2 without cirrhosis had higher odds of mortality. Vaccinated (vs unvaccinated) individuals with HBV/SARS-CoV-2 had 57%, 54%, and 29% reduction in 30-day, 90-day, and overall mortality, respectively. The pre-Delta variant period was associated with higher odds of hospitalization compared to the Omicron but not the Delta period.

Conclusions

Chronic HBV was associated with worse SARS-CoV-2 outcomes, whereas SARS-CoV-2 vaccination reduced the likelihood of adverse outcomes.

Increased gastrointestinal bleeding-related mortality during the COVID-19 pandemic

BACKGROUND

Despite its significant health burden, there is a lack of national-level temporal patterns in gastrointestinal bleeding (GIB) mortality.

OBJECTIVES

To comprehensively decipher the annual and monthly trend of GIB-related mortality in the United States.

DESIGN

Cross-sectional study.

METHODS

We analyzed the National Vital Statistic System database, which documents more than 99% of the annual deaths in the United States for GIB-related deaths from January 2010 to May 2023. Annual and monthly age-standardized mortality rates were estimated and categorized by age, sex, and bleeding site. Joinpoint regression was performed for trend analysis. Prediction modeling was conducted to determine the GIB-associated excess mortality.

RESULTS

A total of 529,094 and 210,641 GIB-associated deaths occurred before and after 2020, respectively. Following a stably decreasing trend between 2010 and 2019, there was an excess mortality rate during the pandemic which peaked in 2021. The monthly mortality trend showed spikes corresponding to the outbreak of variants. Importantly, excess GIB-related mortality resolved in 2023, with the convergence of predicted and observed mortality rates. Subgroup analysis showed that young males (aged 19-44 years) were affected the most during the pandemic, with excess mortality rates of 35.80%, 52.77%, and 31.46% in 2020, 2021, and 2022, respectively. While the increasing trend of upper GIB was accentuated during the pandemic, lower GIB showed a reversal of the pre-pandemic decreasing trend.

CONCLUSION

Our findings demonstrate the trend of GIB-related mortality, underscoring an increased excess death during the pandemic followed by a resolution in 2023. We identify subpopulations vulnerable to the pandemic.

Tackling persistent neurological symptoms in patients following acute COVID-19 infection: an update of the literature

INTRODUCTION

The COVID-19 pandemic has taught myriad lessons and left several questions we are yet to comprehend. Initially, the scientific community was concerned with the management of acute disease and immunization. Once the peak of the pandemic receded, it became clear that a proportion of patients were far from fully recovered. Researchers started to recognize those persisting symptoms as a new entity termed 'Long COVID,' where neurological symptoms are evident and have a major impact on quality of life.

AREAS COVERED

The main purpose of this narrative review is to analyze and synthesize the current literature regarding Long COVID, its relation to the nervous system, and to explore the evidence on treatments for persistent neurological symptoms. The most common reported and observed neurologic manifestations include fatigue, cognitive impairment, pain, polyneuropathy, and neuropsychiatric disorders. A variety of pharmacologic and non-pharmacologic therapies have been evaluated and yielded mixed results. Many of them focused on immunomodulation and none currently have U.S. FDA approval.

EXPERT OPINION

Challenges remain in terms of clinical characterization and prognosis of Long COVID, besides understanding its pathophysiology. Standardization of biomarkers and diagnostic criteria will allow the use of common nomenclature and data elements in the design of future clinical studies.

Muscle mass, muscle strength and the renin-angiotensin system

The renin-angiotensin system (RAS) is a classically known circulatory regulatory system. In addition to the previously known multi-organ circulatory form of the RAS, the existence of tissue RASs in individual organs has been well established. Skeletal muscle has also been identified as an organ with a distinct RAS. In recent years, the effects of RAS activation on skeletal muscle have been elucidated from several perspectives: differences in motor function due to genetic polymorphisms of RAS components, skeletal muscle dysfunction under conditions of excessive RAS activation such as heart failure, and the effects of the use of RAS inhibitors on muscle strength. In addition, the concept of the RAS itself has recently been expanded with the discovery of a 'protective arm' of the RAS formed by factors such as angiotensin-converting enzyme 2 and angiotensin 1-7. This has led to a new understanding of the physiological function of the RAS in skeletal muscle. This review summarizes the diverse physiological functions of the RAS in skeletal muscle and considers the potential of future therapeutic strategies targeting the RAS to overcome problems such as sarcopenia and muscle weakness associated with chronic disease.

The biological and psychological impact of the Coronavirus disease-19 pandemic on the characteristics of the menstrual cycle

The Coronavirus disease-19 (COVID-19) pandemic was declared in March 2020 by the World Health Organization. The severe acute respiratory syndrome-coronavirus-2 virus enters host cells through angiotensin-converting enzyme 2 receptors and transmembrane serine protease type II that are expressed in pulmonary alveoli, as well as in hepatocytes, endothelium, ovaries, uterus, vagina, thyroid, and other tissues. In addition to viral injury, the COVID-19 pandemic, through protective measures such as social isolation and lockdown, has promoted a scenario of psychosocial stress, especially in women. In this context of isolation, anxiety, fear, and mental distress, there is dysregulation of the hypothalamic-pituitary-adrenal axis and subsequent gonadal side effects. Furthermore, studies report an association between COVID-19 and temporary menstrual cycle alterations such, as increased cycle duration, decreased cycle duration, increased menstrual flow, dysmenorrhea, and amenorrhea. Regarding COVID-19 vaccination, menstrual irregularities have been observed in about half of the women, predominantly with a decrease in cycle duration and increased menstrual flow, but without fertility sequelae. The aim of this study was to review the most up-to-date information on the relationship between the COVID-19 pandemic and menstrual irregularities.

Binding affinity between coronavirus spike protein and human ACE2 receptor

Coronaviruses (CoVs) pose a major risk to global public health due to their ability to infect diverse animal species and potential for emergence in humans. The CoV spike protein mediates viral entry into the cell and plays a crucial role in determining the binding affinity to host cell receptors. With particular emphasis on α- and β-coronaviruses that infect humans and domestic animals, current research on CoV receptor use suggests that the exploitation of the angiotensin-converting enzyme 2 (ACE2) receptor poses a significant threat for viral emergence with pandemic potential. This review summarizes the approaches used to study binding interactions between CoV spike proteins and the human ACE2 (hACE2) receptor. Solid-phase enzyme immunoassays and cell binding assays allow qualitative assessment of binding but lack quantitative evaluation of affinity. Surface plasmon resonance, Bio-layer interferometry, and Microscale Thermophoresis on the other hand, provide accurate affinity measurement through equilibrium dissociation constants (KD). In silico modeling predicts affinity through binding structure modeling, protein-protein docking simulations, and binding energy calculations but reveals inconsistent results due to the lack of a standardized approach. Machine learning and deep learning models utilize simulated and experimental protein-protein interaction data to elucidate the critical residues associated with CoV binding affinity to hACE2. Further optimization and standardization of existing approaches for studying binding affinity could aid pandemic preparedness. Specifically, prioritizing surveillance of CoVs that can bind to human receptors stands to mitigate the risk of zoonotic spillover.

Is there a rationale for hyperbaric oxygen therapy in the patients with Post COVID syndrome? : A critical review

The SARS-CoV-2 pandemic has resulted in 762 million infections worldwide from 2020 to date, of which approximately ten percent are suffering from the effects after infection in 2019 (COVID-19) [1, 40]. In Germany, it is now assumed that at least one million people suffer from post-COVID condition with long-term consequences. These have been previously reported in diseases like Myalgic Encephalomyelitis (ME) and Chronic Fatigue Syndrome (CFS). Symptoms show a changing variability and recent surveys in the COVID context indicate that 10-30 % of outpatients, 50 to 70% of hospitalised patients suffer from sequelae. Recent data suggest that only 13% of all ill people were completely free of symptoms after recovery [3, 9]. Current hypotheses consider chronic inflammation, mitochondrial dysfunction, latent viral persistence, autoimmunity, changes of the human microbiome or multilocular sequelae in various organ system after infection. Hyperbaric oxygen therapy (HBOT) is applied since 1957 for heart surgery, scuba dive accidents, CO intoxication, air embolisms and infections with anaerobic pathogens. Under hyperbaric pressure, oxygen is physically dissolved in the blood in higher concentrations and reaches levels four times higher than under normobaric oxygen application. Moreover, the alternation of hyperoxia and normoxia induces a variety of processes at the cellular level, which improves oxygen supply in areas of locoregional hypoxia. Numerous target gene effects on new vessel formation, anti-inflammatory and anti-oedematous effects have been demonstrated [74]. The provision of intermittently high, local oxygen concentrations increases repair and regeneration processes and normalises the predominance of hyperinflammation. At present time only one prospective, randomized and placebo-controlled study exists with positive effects on global cognitive function, attention and executive function, psychiatric symptoms and pain interference. In conclusion, up to this date HBO is the only scientifically proven treatment in a prospective randomized controlled trial to be effective for cognitive improvement, regeneration of brain network and improvement of cardiac function. HBOT may have not only theoretical but also potential impact on targets of current pathophysiology of Post COVID condition, which warrants further scientific studies in patients.

Elimination of olfactory sensory neurons by zinc sulfate inoculation prevents SARS-CoV-2 infection of the brain in K18-hACE2 transgenic mice

Coronavirus disease-2019 (COVID-19), attributed to the severe acute respiratory syndrome-related coronavirus-2 (SARS-CoV-2), has posed global health challenges since it first emerged in 2019, and its impact continues to persist. The neurotropic nature of SARS-CoV-2 remains undisclosed, though researchers are proposing hypotheses on how the virus is transmitted to the central nervous system. One of the prevailing hypotheses is that SARS-CoV-2 travels through the olfactory nerve system via the olfactory epithelium (OE). Using a K18-human angiotensin converting-enzyme 2 (hACE2) transgenic mouse model with impaired olfactory sensory neurons (OSNs) induced by zinc sulfate, we examined the role of the olfactory nerve in the brain invasion by SARS-CoV-2. Mice lacking OSNs exhibited reduced levels of viral transmission to the brain, leading to significantly improved outcomes following SARS-CoV-2 infection. Moreover, a positive correlation was observed between viral persistence in the OE and brain infection. These results indicate that early inhibition of the olfactory nerve pathway effectively prevents viral invasion of the brain in K18-hACE2 mice. Our study underscores the significance of the olfactory nerve pathway in the transmission of SARS-CoV-2 to the brain.

Cardiovascular and kidney diseases are positively associated with neuroinflammation and reduced brain-derived neurotrophic factor in patients with severe COVID-19

Even though respiratory dysfunctions are the primary symptom associated with SARS-CoV-2 infection, cerebrovascular events, and neurological symptoms are described in many patients. However, the connection between the neuroimmune profile and the lung's inflammatory condition during COVID-19 and its association with the neurological symptoms reported by COVID-19 patients still needs further exploration. The present study characterizes the SARS-CoV-2 infectivity profile in postmortem nervous and lung tissue samples of patients who died due to severe COVID-19, and the pro-inflammatory factors present in both nervous and lung tissue samples, via a proteomic profiling array. Additionally, Brain-Derived Neurotrophic Factor (BDNF) levels and intracellular pathways related to neuroplasticity/neuroprotection were assessed in the samples. Out of the 16 samples analyzed, all samples but 1 were positive for the viral genome (genes E or N2, but only 3.9% presented E and N2) in the olfactory brain pathway. The E or N2 gene were also detected in all lung samples, with 43.7% of the samples being positive for the E and N2 genes. In the E/N2 positive brain samples, the Spike protein of SARS-CoV-2 co-localized with TUJ-1+ (neuron-specific class III beta-tubulin) and GFAP+ (glial fibrillary acidic protein) astrocytes. IL-6, but not IL-10, expression was markedly higher in most nervous tissue samples compared to the lung specimens. While intracellular adhesion molecule-1 (ICAM-1), interleukin-8 (IL-8), macrophage migration inhibitory factor (MIF), and plasminogen activator inhibitor 1 (PAI-1) were increased in lung samples from SARS-Cov-2 patients, only MIF and IL-18 were detected in nervous tissue samples. Correlation analysis suggested that high levels of IL-6 are followed by increased levels of IL-10 in the brain, but not in lung samples. Our analysis also demonstrated that the presence of comorbidities, such as cardiovascular disease, hypertension, and hypothyroidism, is associated with neuroinflammation, while chronic kidney conditions predict the presence of neurological symptoms, which correlate with lower levels of BDNF in the brain samples. Our results corroborate the hypothesis that a pro-inflammatory state might further impair neural homeostasis and induce brain abnormalities found in COVID-19 patients.

Cytoskeletal β-tubulin and cysteine cathepsin L deregulation by SARS-CoV-2 spike protein interaction with the neuronal model cell line SH-SY5Y

SARS-CoV-2 mainly infects the respiratory tract but can also target other organs, including the central nervous system. While it was recently shown that cells of the blood-brain-barrier are permissive to SARS-CoV-2 infection in vitro, it remains debated whether neurons can be infected. In this study, we demonstrate that vesicular stomatitis virus particles pseudotyped with the spike protein of SARS-CoV-2 variants WT, Alpha, Delta and Omicron enter the neuronal model cell line SH-SY5Y. Cell biological analyses of the pseudo-virus treated cultures showed marked alterations in microtubules of SH-SY5Y cells. Because the changes in β-tubulin occurred in most cells, but only few were infected, we further asked whether interaction of the cells with spike protein might be sufficient to cause molecular and structural changes. For this, SH-SY5Y cells were incubated with trimeric spike proteins for time intervals of up to 24 h. CellProfiler™-based image analyses revealed changes in the intensities of microtubule staining in spike protein-incubated cells. Furthermore, expression of the spike protein-processing protease cathepsin L was found to be up-regulated by wild type, Alpha and Delta spike protein pseudotypes and cathepsin L was found to be secreted from spike protein-treated cells. We conclude that the mere interaction of the SARS-CoV-2 with neuronal cells can affect cellular architecture and proteolytic capacities. The molecular mechanisms underlying SARS-CoV-2 spike protein induced cytoskeletal changes in neuronal cells remain elusive and require future studies.

Antiseptics: An expeditious third force in the prevention and management of coronavirus diseases

Notably, severe acute respiratory syndrome (SARS), Middle East respiratory syndrome (MERS) and coronavirus disease 2019 (COVID-19) have all had significant negative impact on global health and economy. COVID-19 alone, has resulted to millions of deaths with new cases and mortality still being reported in its various waves. The development and use of vaccines have not stopped the transmission of SARS coronavirus 2 (SARS-CoV-2), the etiological agent of COVID-19, even among vaccinated individuals. The use of vaccines and curative drugs should be supplemented with adoption of simple hygiene preventive measures in the fight against the spread of the virus, especially for healthcare workers. Several virucidal topical antiseptics, such as povidone-iodine (PVP-I), citrox, cyclodextrins among others, have been demonstrated to be efficacious in the inactivation of SARS-CoV-2 and other coronaviruses in both in vitro and in vivo studies. The strategic application of these virucidal formulations could provide the additional impetus needed to effectively control the spread of the virus. We have here presented a simple dimension towards curtailing the dissemination of COVID-19, and other coronaviruses, through the application of effective oral, nasal and eye antiseptics among patients and medical personnel. We have further discussed the mechanism of action of some of these commonly available virucidal solutions while also highlighting some essential controversies in their use.

Identification of COVID-19-Associated Hepatitis in Children as an Emerging Complication in the Wake of SARS-CoV-2 Infections: Ambispective Observational Study

Background

Although the pediatric population has largely remained free of severe COVID-19 symptoms, in some cases, SARS-CoV-2 infection has been associated with complications such as multiple inflammatory syndrome in children (MIS-C). We identified another a unique form of hepatitis occurring subsequent to asymptomatic SARS-CoV-2 infection, designated by us as COVID-19-associated hepatitis in children (CAH-C), in a subset of children who presented with hepatitis.

Objective

Our study describes the clinical presentations, temporal association, and viral parameters of the CAH-C cases and compares them to those of MIS-C cases or other known forms of hepatitis in children.

Methods

In an ambispective (retrospective and follow-up) observational study, records from April to July 2021 were reviewed for all children aged ≤14 years who were previously healthy and presented with a sudden onset of hepatitis, elevated transaminases, and nonobstructive jaundice. After performing all routine tests, those lacking marked inflammatory responses and without evidence of (1) other known causes of acute hepatitis or previous underlying liver disease and (2) multisystem involvement were classified as having CAH-C. Their characteristics were compared to those of children with MIS-C or other known forms of hepatitis.

Results

Among the 5539 children tested for SARS-CoV-2, a total of 475 (8.6%) tested positive and 47 (0.8%) presented with hepatitis. Among the 47 children with hepatitis, 37 (79%) had features of CAH-C: having symptoms of hepatitis only, without protracted illness (mean length of stay 5 d), and an uneventful recovery following supportive treatment. In contrast, the remaining 10 (21%) had features of MIS-C-associated hepatitis: multiple system involvement; protracted illness (mean length of stay 8 d); and requiring admission to critical care, with a mortality rate of 30% (3/10).

Conclusions

Our data suggest that CAH-C might be one of the new clinical complications associated with the emergence of newer variants of concern of SARS-CoV-2, which often result in changing presentations. Our findings should facilitate its early identification and thorough workup and aid its differentiation from other emerging syndromes in children, which would help initiate appropriate measures, enable better resource prioritization, and thus limit adversities.

Characteristics of Patients with Persistent COVID-19 Symptoms and Unscheduled Return Visits to a Centre for COVID-19 Evaluation

Background: This retrospective study aimed to evaluate the characteristics of patients with long COVID syndrome. Methods: This study included 457 adults who had at least one persistent symptom after COVID-19 infection. Results: The median time interval between the last SARS-CoV-2 infection and emergency room presentation was 3 months. Older patients had comorbidities (61.7 vs. 44.9 years, p < 0.0001), moderate or severe forms of COVID-19 (61.2 vs. 50.9 years, p < 0.0001), and respiratory symptoms (56.1 vs. 52.0 years, p = 0.0027). Non-vaccinated patients were older than vaccinated patients (56.0 vs. 51.5 years, p = 0.0008) and had residual lung abnormalities following COVID-19 infection (51.5% vs. 36.8%, p < 0.003). The time interval between the last SARS-CoV-2 infection and the hospital evaluation was shorter for vaccinated patients (3.2 vs. 3.9 months, p < 0.0001) and those with mild forms (3.3 vs. 4.12 months, p = 0.0001) versus non-vaccinated individuals. After the last SARS-CoV-2 infection, 107 patients developed impaired fasting glucose, impaired glucose tolerance, or diabetes mellitus, being patients with already known chronic diseases (p = 0.0002), or hypertension (p = 0.001). Conclusions: Our study pointed out the heterogeneity of symptoms following COVID-19, and they are associated with age, vaccination status, or severity of SARS-CoV-2 infection.

Radiotracers for Molecular Imaging of Angiotensin-Converting Enzyme 2

Angiotensin-converting enzymes (ACE) are well-known for their roles in both blood pressure regulation via the renin-angiotensin system as well as functions in fertility, immunity, hematopoiesis, and many others. The two main isoforms of ACE include ACE and ACE-2 (ACE2). Both isoforms have similar structures and mediate numerous effects on the cardiovascular system. Most remarkably, ACE2 serves as an entry receptor for SARS-CoV-2. Understanding the interaction between the virus and ACE2 is vital to combating the disease and preventing a similar pandemic in the future. Noninvasive imaging techniques such as positron emission tomography and single photon emission computed tomography could noninvasively and quantitatively assess in vivo ACE2 expression levels. ACE2-targeted imaging can be used as a valuable tool to better understand the mechanism of the infection process and the potential roles of ACE2 in homeostasis and related diseases. Together, this information can aid in the identification of potential therapeutic drugs for infectious diseases, cancer, and many ACE2-related diseases. The present review summarized the state-of-the-art radiotracers for ACE2 imaging, including their chemical design, pharmacological properties, radiochemistry, as well as preclinical and human molecular imaging findings. We also discussed the advantages and limitations of the currently developed ACE2-specific radiotracers.

Retrospective Study on the Features and Outcomes of a Tuscany COVID-19 Hospitalized Patients Cohort: Preliminary Results

Background: A few months after the COVID-19 pandemic onset, knowledge of SARS-CoV-2 infection and outcomes and treatments blew up. This paper aimed to evaluate the features of a Tuscany COVID-19 hospitalized cohort and to identify risk factors for COVID-19 severity. Methods: This retrospective observational COVID-19 cohort study (1 March 2020-1 March 2021) was conducted on patients ≥ 18 years old, admitted to Tuscany Hospital, and subjected to follow-up within 12 months after discharge. Patients were enrolled at Pisana, Senese and Careggi University Hospitals, and South East, North West, and Center Local Hospitals. Results: 2888 patients (M = 58.5%, mean age = 66.2 years) were enrolled, of whom 14.3% (N = 413) were admitted to an intensive care unit. Smokers were 25%, and overweight and obese 65%. The most used drugs were corticosteroids, antacids, antibiotics, and antithrombotics, all antiviral drugs, with slight differences between 2020 and 2021. A strong association was found between outcomes of evolution towards critical COVID-19 (non-invasive mechanical ventilation (NIV) and/or admission to intensive care) and smoking (RR = 4.91), ex-smoking (RR = 3.48), overweight (RR = 1.30), obese subjects (RR = 1.62), comorbidities (aRR = 1.38). The alteration of liver enzymes (aspartate aminotransferase, alanine aminotransferase, or gamma-glutamyl transpeptidase) was associated with NIV (aOR = 2.28). Conclusions: Our cohort, characterized by patients with a mean age of 66.2 years, showed 65% of patients were overweight and obese. Smoking/ex-smoking, overweight/obesity, and other comorbidities were associated with COVID-19 adverse outcomes. The findings also demonstrated that alterations in liver enzymes were associated with worse outcomes.

COVID-19 and menstrual-related disturbances: a Spanish retrospective observational study in formerly menstruating women

Introduction

Four years after the start of the pandemic, there is limited evidence on the impact of COVID-19 on the women's health regardless of their reproductive status.

Objective

The aim was to analyze the prevalence and associated factors of menstrual-related disturbances in formerly menstruating women following SARS-CoV-2 infection.

Study design

A retrospective observational study of adult women in Spain was conducted during the month of December 2021 using an online survey (N = 17,512). The present analysis includes a subpopulation of SARS-CoV-2-infected and formerly menstruating women (n = 72). The collected data included general characteristics, medical history, and specific information on COVID-19. Chi-square and Mann-Whitney U-tests were performed. Bivariate logistic regression analysis was then performed to investigate possible associations between the occurrence of menstrual-related disturbances after SARS-CoV-2 infection.

Results

38.8% of participants experienced menstrual-related disturbances following COVID-19. Among these, unexpected vaginal bleeding (20.8%) was the most common event, followed by spotting (11.1%) ( Table 1). Other reported changes were in the length (shorter = 12.5%) and flow (heavier = 30.3%) of menstrual bleeding in comparison to their previous experience. Regression analysis revealed that being a perimenopausal woman [adjusted odds ratio (AOR) 4.721, CI 95%, 1.022-21.796, p = 0.047] and having a previous diagnosis of menorrhagia (AOR 5.824 CI 95%, 1.521-22.310, p = 0.010) were factors associated with the event.

Conclusion

These findings could help health professionals provide their patients with up-to-date scientific information to empower them to actively manage their reproductive health, especially in societies where menstrual health is still taboo.

Role of IL-27 in COVID-19: A Thin Line between Protection and Disease Promotion

Cytokine storm is usually described as one of the main reasons behind COVID-associated mortality. Cytokines are essential protein molecules engaged in immune responses; they play a critical role in protection against infections. However, they also contribute to inflammatory reactions and tissue damage, becoming a double-edged sword in the context of COVID-19. Recent studies have suggested various cytokines and chemokines that play a crucial role in the immune response to SARS-CoV-2 infection. One such cytokine is interleukin 27 (IL-27), which has been found to be elevated in the blood plasma of patients with COVID-19. Within this study, we will explore the role of IL-27 in immune responses and analyze both the existing literature and our own prior research findings on this cytokine in the context of COVID-19. It affects a wide variety of immune cells. Regardless of the pathological process it is involved in, IL-27 is critical for upholding the necessary balance between tissue damage and cytotoxicity against infectious agents and/or tumors. In COVID-19, it is involved in multiple processes, including antiviral cytotoxicity via CD8+ cells, IgG subclass switching, and even the activation of Tregs.

Assessing the impact of COVID-19 on acute leukemia patients: a comparative analysis of hematological and biochemical parameters

BACKGROUND

The impact of COVID-19 infection on the blood system remains to be investigated, especially with those encountering hematological malignancies. It was found that a high proportion of cancer patients are at an elevated risk of encountering COVID-19 infection. Leukemic patients are often suppressed and immunocompromised, which would impact the pathology following COVID-19 infection. Therefore, this research aims to bring valuable insight into the mechanism by which COVID-19 infection influences the hematological and biochemical parameters of patients with acute leukemia.

METHODS

This retrospective investigation uses repeated measures to examine changes in hematological and biochemical parameters among patients with acute leukemia before and after COVID-19 infection at a major Saudi tertiary center. The investigation was conducted at the Ministry of National Guard-Health Affairs in Riyadh, Saudi Arabia, on 24 acute leukemia patients with COVID-19 between April 2020 and July 2023. The impact of COVID-19 on clinical parameters, comorbidities, and laboratory values was evaluated using data obtained from the electronic health records at four designated time intervals. The relative importance of comorbidities, testing preferences, and significant predictors of survival was ascertained.

RESULTS

The majority of leukemic COVID-19-infected patients, primarily detected through PCR tests, were diagnosed with acute lymphoblastic leukemia (70.8%). The hematological and biochemical parameters exhibited stability, except for a brief increase in ALT and a sustained rise in AST. These changes were not statistically significant, and parameters remained normal at all time points. Additionally, an increase in monocyte count was shown at time point-3, as well as platelet counts at time point 2.

CONCLUSION

While this study did not detect statistically significant effects of COVID-19 on biochemical and hematological parameters in acute leukemia patients, further investigation is needed to fully understand the potential adverse reactions and modifications following COVID-19 infection.

New insights into the pathogenesis of SARS-CoV-2 during and after the COVID-19 pandemic

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is responsible for the respiratory distress condition known as COVID-19. This disease broadly affects several physiological systems, including the gastrointestinal, renal, and central nervous (CNS) systems, significantly influencing the patient's overall quality of life. Additionally, numerous risk factors have been suggested, including gender, body weight, age, metabolic status, renal health, preexisting cardiomyopathies, and inflammatory conditions. Despite advances in understanding the genome and pathophysiological ramifications of COVID-19, its precise origins remain elusive. SARS-CoV-2 interacts with a receptor-binding domain within angiotensin-converting enzyme 2 (ACE2). This receptor is expressed in various organs of different species, including humans, with different abundance. Although COVID-19 has multiorgan manifestations, the main pathologies occur in the lung, including pulmonary fibrosis, respiratory failure, pulmonary embolism, and secondary bacterial pneumonia. In the post-COVID-19 period, different sequelae may occur, which may have various causes, including the direct action of the virus, alteration of the immune response, and metabolic alterations during infection, among others. Recognizing the serious adverse health effects associated with COVID-19, it becomes imperative to comprehensively elucidate and discuss the existing evidence surrounding this viral infection, including those related to the pathophysiological effects of the disease and the subsequent consequences. This review aims to contribute to a comprehensive understanding of the impact of COVID-19 and its long-term effects on human health.

Mapping ACE2 and TMPRSS2 co-expression in human brain tissue: implications for SARS-CoV-2 neurological manifestations

The Coronavirus Disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) primarily targets respiratory cells, but emerging evidence shows neurological involvement, with the virus directly affecting neurons and glia. SARS-CoV-2 entry into a target cell requires co-expression of ACE2 (Angiotensin-converting enzyme-2) and TMPRSS2 (Trans membrane serine protease-2). Relevant literature on human neurological tissue is sparse and mostly focused on the olfactory areas. This prompted our study to map brain-wide expression of these entry proteins and assess age-related changes. The normal brain tissue samples were collected from cerebral cortex, hippocampus, basal ganglia, thalamus, hypothalamus, brain stem and cerebellum; and were divided into two groups - up to 40 years (n = 10) and above 40 years (n = 10). ACE2 and TMPRSS2 gene expression analysis was done using qRT-PCR and protein co-expression was seen by immunofluorescence. The ACE2 and TMPRSS2 gene expression was observed to be highest in hypothalamus and thalamus regions, respectively. Immunoreactivity for both ACE-2 and TMPRSS2 was observed in all examined brain regions, confirming the presence of these viral entry receptors. Co-localisation was maximum in hypothalamus. Our study did not find any trend related to different age groups. The expression of both these viral entry receptors suggests that normal human brain is susceptibility to SARS-CoV-2, perhaps which could be related to the cognitive and neurological impairment that occur in patients.

Critical appraisal of how COVID-19 infection and imposed lockdowns have impacted gastroesophageal reflux: A review

Previous literature has demonstrated that COronaVIrus Disease of 2019 (COVID-19) impacts an individual gastrointestinal tract (GIT), causing symptoms like nausea, diarrhea, and loss of appetite. Severe acute respiratory syndrome coronavirus RNA has been discovered in the stool of infected individuals in earlier research. It was discovered that severe acute respiratory syndrome coronavirus was significantly expressed in the GIT, indicating that the virus can also infect the digestive system. Angiotensin-converting enzyme 2 functions as the viral receptor. The chronic illness known as gastroesophageal reflux disease (GERD) is typified by frequent reflux of stomach acid into the esophagus. By triggering the sensitized esophageal-bronchial neuronal circuit or aspirating into the airways (microaspiration), GER exacerbates respiratory diseases. Aspiration is a well-known risk to be considered when treating patients in intensive care units. Strong genetic correlations have been identified between COVID-19 infection and GERD susceptibility, suggesting a shared genetic basis for both conditions. Nonetheless, even though GERD, extraesophageal reflex, and COVID-19 have a number of significant risk factors and exhibit similar symptoms, the relationship between these illnesses has not yet been examined in depth. This review is the first of its kind to critically examine the association between the COVID-19 epidemic and GER and its associated diseases. The key objective of this work is to promote the creation of prevention plans, treatment plans, and guidelines while also enhancing and optimizing our understanding of the relationship between COVID-19 and GERs.

SARS-CoV-2-Related Olfactory Dysfunction: Autopsy Findings, Histopathology, and Evaluation of Viral RNA and ACE2 Expression in Olfactory Bulbs

BACKGROUND

The COVID-19 pandemic has been a health emergency with a significant impact on the world due to its high infectiousness. The disease, primarily identified in the lower respiratory tract, develops with numerous clinical symptoms affecting multiple organs and displays a clinical finding of anosmia. Several authors have investigated the pathogenetic mechanisms of the olfactory disturbances caused by SARS-CoV-2 infection, proposing different hypotheses and showing contradictory results. Since uncertainties remain about possible virus neurotropism and direct damage to the olfactory bulb, we investigated the expression of SARS-CoV-2 as well as ACE2 receptor transcripts in autoptic lung and olfactory bulb tissues, with respect to the histopathological features.

METHODS

Twenty-five COVID-19 olfactory bulbs and lung tissues were randomly collected from 200 initial autopsies performed during the COVID-19 pandemic. Routine diagnosis was based on clinical and radiological findings and were confirmed with post-mortem swabs. Real-time RT-PCR for SARS-CoV-2 and ACE2 receptor RNA was carried out on autoptic FFPE lung and olfactory bulb tissues. Histological staining was performed on tissue specimens and compared with the molecular data.

RESULTS

While real-time RT-PCR for SARS-CoV-2 was positive in 23 out of 25 lung samples, the viral RNA expression was absent in olfactory bulbs. ACE2-receptor RNA was present in all tissues examined, being highly expressed in lung samples than olfactory bulbs.

CONCLUSIONS

Our finding suggests that COVID-19 anosmia is not only due to neurotropism and the direct action of SARS-CoV-2 entering the olfactory bulb. The mechanism of SARS-CoV-2 neuropathogenesis in the olfactory bulb requires a better elucidation and further research studies to mitigate the olfactory bulb damage associated with virus action.

Theoretical Investigation of the Green-Synthesized Carbon-Based Nanomaterial Potential as Inhibitors of ACE2 for Blocking SARS-CoV-2 Binding

Since the emergence of SARS-CoV-2 in 2020, the world has faced a global pandemic, emphasizing the urgent need for effective treatments to combat COVID-19. This study explores the use of green-synthesized carbon-based nanomaterials as potential inhibitors of ACE2, a critical receptor for SARS-CoV-2 entry into host cells. Specifically, the study examines four carbon-based nanomaterials, namely, CD1, CD2, CD3, and CD4 in amino, graphitic, pyridinic, and pyrrolic forms, respectively, synthesized from curcumin, to investigate their binding affinity with ACE2. Molecular docking studies revealed that CD3 (pyridinic form) exhibited the highest binding affinity with ACE2, surpassing that of the control compound, curcumin. Notably, CD3 formed hydrophobic interactions and hydrogen bonds with key ACE2 residues, suggesting its potential to block the binding of SARS-CoV-2 to human cells. Moreover, molecular dynamics simulations demonstrated the stability of these ligand-ACE2 complexes, further supporting the promise of CD3 as an inhibitor. Quantum chemical analyses, including frontier molecular orbitals, natural bond orbital analysis, and the quantum theory of atoms in molecules, unveiled valuable insights into the reactivity and interaction strengths of these ligands. CD3 exhibited desirable chemical properties, signifying its suitability for therapeutic development. The study's findings suggest that green-synthesized carbon-based nanomaterials, particularly CD3, have the potential to serve as effective inhibitors of ACE2, offering a promising avenue for the development of treatments against COVID-19. Further experimental validation is warranted to advance these findings and establish new therapies for the ongoing global pandemic.

Neuroinvasion of severe acute respiratory syndrome corona virus-2 (SARS-CoV-2): future risk of epilepsy

Central nervous system (CNS) infection is one of the important risk factors for epilepsy. COVID-19 pandemic, which is caused by severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) has primarily been considered to involve respiratory system only, but it can also affect the CNS. A wide range of neurological manifestations have been reported in SARS-CoV-2 infected patients including seizures, status epilepticus, stroke, which are considered as important risk factors for the development of epilepsy. In post-mortem, brain tissue samples of COVID-19 patients have shown neuropathological changes and presence of SARS-CoV-2 RNA and viral proteins. In this review, mechanisms of SARS-CoV-2 neuroinvasion like neuronal retrograde trans-synaptic route and vascular route are described along with important neurological manifestations in COVID-19 patients such as seizures and cerebrovascular diseases, which have been found to be associated with the development of epilepsy. Hence, an increased risk of future burden of epilepsy in susceptible COVID-19 survivors has been proposed and preventive measures are suggested. The present review highlights about the possible association between neurological manifestations and future risk of epilepsy in COVID-19 patients.

The Renin-Angiotensin System (RAS) in COVID-19 Disease: Where We Are 3 Years after the Beginning of the Pandemic

The RAS is a hormonal system playing a pivotal role in the control of blood pressure and electrolyte homeostasis, the alteration of which is associated with different pathologies, including acute respiratory distress syndrome (ARDS). As such, it is not surprising that a number of studies have attempted to elucidate the role and balance of the renin-angiotensin system (RAS) in COVID-19. In this review article, we will describe the evidence collected regarding the two main enzymes of the RAS (i.e., ACE and ACE2) and their principal molecular products (i.e., AngII and Ang1-7) in SARS-CoV-2 infection, with the overarching goal of drawing conclusions on their possible role as clinical markers in association with disease severity, progression, and outcome. Moreover, we will bring into the picture new experimental data regarding the systemic activity of ACE and ACE2 as well as the concentration of AngII and Ang1-7 in a cohort of 47 COVID-19 patients hospitalized at the IRCCS Sacro Cuore-Don Calabria Hospital (Negrar, Italy) between March and April 2020. Finally, we will discuss the possibility of considering this systemic pathway as a clinical marker for COVID-19.

Clinical characteristics of 4,520 paediatric patients infected with the SARS-CoV-2 omicron variant, in Xi'an, China

Background and objective

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has broad tissue tropism and high transmission, which are likely to perpetuate the pandemic. The study aim to analyze the clinicopathogenic characteristics in paediatric patients.

Methods

In this single-centre study, we retrospectively included all confirmed cases infected by SARS-CoV-2 infection at Xi'an Children's Hospital, China, from 1 December to 31 December 2022. The demographic, clinical, laboratory, and radiological features of the patients were analysed.

Results

A total of 4,520 paediatric patients with SARS-CoV-2 omicron variant infections were included. Of these, 3,861 (85.36%) were outpatients, 659 (14.64%) were hospitalised patients, and nine patients (0.20%) died. Of the nine patients who died, five were diagnosed with acute necrotising encephalopathy (ANE). The most common symptoms were fever in 4,275 (94.59%) patients, cough in 1,320 (29.20%) patients, convulsions in 610 (13.50%) patients, vomiting in 410 (9.07%) patients, runny nose/coryza in 277 (6.13%) patients, hoarseness of voice in 273 (6.04%) patients. A blood cell analysis showed a slight elevation of monocytes (mean: 11.14 ± 0.07%). The main diagnoses for both outpatients and inpatients were respiratory infection with multisystem manifestations.

Conclusions

A high incidence of convulsions is a typical characteristic of children infected with SARS-CoV-2. Five of the nine COVID-19 fatalities were associated with ANE. This indicates that nervous system damage in children with SARS-CoV-2 infection is more significant.

COVID-19 and the brain: understanding the pathogenesis and consequences of neurological damage

SARS-CoV-2 has been known remarkably since December 2019 as a strain of pathogenic coronavirus. Starting from the earlier stages of the COVID-19 pandemic until now, we have witnessed many cases of neurological damage caused by SARS-CoV-2. There are many studies and research conducted on COVID-19-positive-patients that have found brain-related abnormalities with clear neurological symptoms, ranging from simple headaches to life-threatening strokes. For treating neurological damage, knowing the actual pathway or mechanism of causing brain damage via SARS-CoV-2 is very important. For this reason, we have tried to explain the possible pathways of brain damage due to SARS-CoV-2 with mechanisms and illustrations. The SARS-CoV-2 virus enters the human body by binding to specific ACE2 receptors in the targeted cells, which are present in the glial cells and CNS neurons of the human brain. It is found that direct and indirect infections with SARS-CoV-2 in the brain result in endothelial cell death, which alters the BBB tight junctions. These probable alterations can be the reason for the excessive transmission and pathogenicity of SARS-CoV-2 in the human brain. In this precise review, we have tried to demonstrate the neurological symptoms in the case of COVID-19-positive-patients and the possible mechanisms of neurological damage, along with the treatment options for brain-related abnormalities. Knowing the transmission mechanism of SARS-CoV-2 in the human brain can assist us in generating novel treatments associated with neuroinflammation in other brain diseases.

Natural products as a source of Coronavirus entry inhibitors

The COVID-19 pandemic has had a significant and lasting impact on the world. Four years on, despite the existence of effective vaccines, the continuous emergence of new SARS-CoV-2 variants remains a challenge for long-term immunity. Additionally, there remain few purpose-built antivirals to protect individuals at risk of severe disease in the event of future coronavirus outbreaks. A promising mechanism of action for novel coronavirus antivirals is the inhibition of viral entry. To facilitate entry, the coronavirus spike glycoprotein interacts with angiotensin converting enzyme 2 (ACE2) on respiratory epithelial cells. Blocking this interaction and consequently viral replication may be an effective strategy for treating infection, however further research is needed to better characterize candidate molecules with antiviral activity before progressing to animal studies and clinical trials. In general, antiviral drugs are developed from purely synthetic compounds or synthetic derivatives of natural products such as plant secondary metabolites. While the former is often favored due to the higher specificity afforded by rational drug design, natural products offer several unique advantages that make them worthy of further study including diverse bioactivity and the ability to work synergistically with other drugs. Accordingly, there has recently been a renewed interest in natural product-derived antivirals in the wake of the COVID-19 pandemic. This review provides a summary of recent research into coronavirus entry inhibitors, with a focus on natural compounds derived from plants, honey, and marine sponges.

Beyond acute infection: molecular mechanisms underpinning cardiovascular complications in long COVID

SARS-CoV-2, responsible for the global COVID-19 pandemic, has manifested significant cardiovascular implications for the infected population. These cardiovascular repercussions not only linger beyond the initial phase of illness but have also been observed in individuals who remain asymptomatic. This extended and pervasive impact is often called the post-acute COVID-19 syndrome (PACS) or "Long COVID". With the number of confirmed global cases approaching an alarming 756 million, the multifaceted challenges of Long COVID are undeniable. These challenges span from individual health complications to considerable burdens on worldwide healthcare systems. Our review comprehensively examines the complications of the persistent cardiovascular complications associated with COVID-19. Furthermore, we shed light on emerging therapeutic strategies that promise to manage and possibly mitigate these complications. We also introduce and discuss the profound concerns regarding the potential transgenerational repercussions of SARS-CoV-2, emphasizing the need for a proactive and informed approach to future research and clinical practice.

Effects of a randomized-controlled and online-supported physical activity intervention on exercise capacity, fatigue and health related quality of life in patients with post-COVID-19 syndrome

BACKGROUND

The Post-COVID-19 syndrome (PCS), which can occur after acute respiratory syndrome coronavirus 2 infection, leads to restrictions in everyday activity. Our study assessed the impact of an online-guided intervention which intended to facilitate physical activity on the mental and physical capability of PCS patients.

METHODS

We randomized 62 patients with PCS (20 male/ 42 female; age: 46 ± 12 years; body mass index: 28.7 ± 6.7 kg/m2) with a score ≥ 22 in the fatigue assessment scale (FAS) to a 3-month exercise-focused intervention (IG n = 30) or control period (CG n = 32). We assessed changes in exercise capacity (bicycle exercise test with measurements of gas exchange), fatigue, markers of health-related quality of life (HrQoL) and mental health.

RESULTS

The FAS score decreased significantly in both study groups (IG: 35.1 ± 7.4 to 31.8 ± 8.5 points; CG: 35.6 ± 7.4 to 32.6 ± 7.5 points, both p < 0.01). Exercise capacity did not increase in the CG or IG (within-group changes for IG: peak oxygen uptake: 0.9 ± 2.6 ml/min/kg, p = 0.098; peak power output: 6.1 ± 17.8 W, p = 0.076) with no significant changes in HrQoL and work ability. Patients with a FAS score at baseline ≥ 35 (severe fatigue) showed no change in exercise capacity with the 3-month intervention whereas the sub-group of patients with FAS < 35 points (moderate fatigue) showed improvements, independent of the study group.

CONCLUSIONS

Our 3-month intervention seems appropriate for patients with moderate fatigue, whereas those with more severe fatigue appear to be too restricted with respect to their mental or physical health status to perform exercise at a level which is sufficient to improve markers of physical performance.

TRIAL REGISTRATION

German Clinical Trials Register (registration trial number: DRKS00026245) on September 2 2021.

Insights into estrogen impact in oral health & microbiome in COVID-19

BACKGROUND

COVID-19 emerged in late 2019 and has occasioned more than 765 millions cumulative cases and 6.9 millions of deaths globally. Notably, around 70% of patients with severe COVID-19 are men. Therefore, it is to be presumed that women have a hormonal protector factor in inflammation and ACE2 expression. On the other hand, oral health status, and local microbiome can be key factors to respiratory viral infections control. Nevertheless, it has been poorly investigated. In our study 20 premenopausal, 18 postmenopausal and 22 men with COVID-19 were included. Oral health status, viral load, lingual ACE2 expression, as well as microbiome, estrogens and cytokines in saliva were analyzed.

RESULTS

Our results showed a lower expression of ACE2 in tongue cells of postmenopausal compared with premenopausal (p = 0.05), and a strong negative correlation between saliva estrogen and viral load (r = -0.76; p = 0.001). Respect to IFN-γ (p = 0.05), IL-1β, TNF-α, IL-18, and IL-23 levels were increased in postmenopausal. Oral microbiome signature of premenopausal was characterized by Prevotella melaninogenica (Log2 = 26.68; p = 1.34e-10), Haemophilus (Log2 = 23.99; p = 2.96e-9), and Alloprevotella (Log2 = 7.92; p = 0.0001). On the other hand, Leptotrichia (Log2 = -18.74; p = 0.001), Tanerella (Log2 = -17.08; p = 0.004), and Clostridiales (Log2 = -2.88; p = 0.04) represented the poor oral health group compared with the adequate group which was enriched with the commensal microorganism Neisseria perflava (Log2 = 26.70; p = 1.74e-7). Furthermore, the high viral load group was characterized by Prevotella nanceiensis (Log2 = 19.60; p = 6.06e-8), Prevotella melaninogenica (Log2 = 21.45; p = 9.59e-6), Alloprevotella (Log2 = 23.50; p = 2.70e-7) and bacteria from the red complex Porphyromonas endodentalis (Log2 = 21.97; p = 1.38e-7).

CONCLUSIONS

Postmenopausal and men have a poor oral health status which could be related to a detrimental progression of COVID-19 also linked to a lower expression of ACE2, lower saliva estrogen levels and oral dysbiosis. Nevertheless, functional studies are required for a deeper knowledge.

Liver damage profile in COVID-19 pregnant patients

INTRODUCTION

SARS-CoV-2 unsparingly impacts all areas of medicine. Pregnant women are particularly affected by the pandemic and COVID-19 related liver damage seems to be another threat to maternal and fetal health. The aim of this study is to define liver damage profile including bile acids serum levels in COVID-19 pregnant patients and to determine predictors of disease aggravation and poor obstetrics outcomes.

METHODS

This study has been carried out in the Obstetrics and Gynecology Department, at the National Medical Institute in Warsaw, Poland between 01.02.2021 and 01.11.2022 The study cohort comprises 148 pregnant patients with COVID-19 and 102 pregnant controls who has been tested negative for SARS-CoV-2.

RESULTS

COVID-19 pregnant patients presented liver involvement at admission in 41,9%. Hepatotoxic damage accounted for 27 (19.85%), cholestatic type was diagnosed in 11 (8.09%) and mixed type of liver injury was presented in 19 (13.97%) of patients. Higher serum levels of AST, ALT, GGT, total bilirubin and bile acids as well as mixed type of liver injury at admission were correlated with severe form of an illness. AST and ALT above upper reference limit as well as hepatotoxic type of liver damage predisposed pregnant patients with COVID-19 to poor obstetrics outcomes.

CONCLUSION

Hepatic damage in pregnant women with COVID-19 is a common, mild, transaminase-dominant, or mixed type of injury, and often correlates with elevated inflammatory markers. SARS-CoV-2 test should be performed as a part of differential diagnosis in elevated liver function tests. Although bile acids serum levels were commonly elevated they seems to be clinically irrelevant in terms of pregnancy outcomes. Video Abstract.

Epidemiology, Symptoms and Pathophysiology of Long Covid Complications

Long COVID, or post-acute sequelae of SARS-CoV-2 infection, reports to affect a significant proportion of COVID-19 survivors, leading to persistent and multi-organ complications. This review examines the epidemiology, symptoms of long COVID complications, including cardiac, hematological, vascular, pulmonary, neuropsychiatric, renal, gastrointestinal, musculoskeletal, immune dysregulation, and dermatological issues. By synthesizing the latest research, this article provides a comprehensive overview of the prevalence and detailed pathophysiological mechanisms underlying these complications. The purpose of this review is to enhance the understanding of diverse and complex nature of long COVID and emphasize the need for ongoing research, seeking to support future studies for better management of long COVID.

Mechanisms of SARS-CoV-2 Placental Transmission

The widespread occurrence of SARS-CoV-2 infections and the diverse range of symptoms have placed significant strain on healthcare systems worldwide. Pregnancy has also been affected by COVID-19, with an increased risk of complications and unfavorable outcomes for expectant mothers. Multiple studies indicate that SARS-CoV-2 can infiltrate the placenta, breach its protective barrier, and infect the fetus. Although the precise mechanisms of intrauterine transmission remain unclear, factors such as perinatal infection, macrophages, sexual intercourse, and the virus' interaction with host angiotensin-converting enzyme 2 (ACE2) and neuropilin-1 (NRP-1) proteins appear to play a role in this process. The integrity of the placental barrier fluctuates throughout pregnancy and appears to influence the likelihood of fetal transmission. The expression of placental cell receptors, like ACE2, changes during pregnancy and in response to placental damage. However, due to the consistent presence of others, such as NRP-1, SARS-CoV-2 may potentially enter the fetus at different stages of pregnancy. NRP-1 is also found in macrophages, implicating maternal macrophages and Hofbauer cells as potential routes for viral transmission. Our current understanding of SARS-CoV-2's vertical transmission pathways remains limited. Some researchers question the ACE2-associated transmission model due to the relatively low expression of ACE2 in the placenta. Existing studies investigating perinatal transmission and the impact of sexual intercourse have either involved small sample sizes or lacked statistical significance. This review aims to explore the current state of knowledge regarding the potential mechanisms of COVID-19 vertical transmission, identifying areas where further research is needed to fill the gaps in our understanding.

Unveiling the Clinical Spectrum of Post-COVID-19 Conditions: Assessment and Recommended Strategies

SARS-CoV-2 caused the pandemic of the rapidly evolving COVID-19. As of December 6, 2023, there were 765,152,854 COVID-19-recovering cases. Long-term consequences known as "long COVID" and "post-COVID-19 conditions" (PCCs) or "post-acute COVID-19 syndrome" are being reported more frequently in a subset of recovering patients. Systemic, neuropsychiatric, cardio-respiratory, and gastrointestinal symptoms are the most prevalent. The management of PCCs poses unique challenges due to the lack of official guidelines and the complex nature of the illness. This abstract highlights key principles derived from recent reviews and expert recommendations to provide healthcare professionals with a comprehensive approach to manage post-COVID-19 patients. Preventive medicine plays a crucial role in managing PCCs. While no specific medications are available for treatment, preventive measures such as COVID-19 vaccination, adherence to precautionary measures, regular consultations with medical professionals, monitoring symptoms and progress, and seeking information on symptom management are essential to assist patients in their recovery and improve their quality of life. Medical management requires transparent goal-setting and collaborative decision-making based on the patient's symptoms, comorbidities, and treatment objectives. Treatment plans for post-COVID-19 patients should focus on patient education, using registries and calendars to track symptoms and triggers, providing support and reassurance, and offering holistic support through peer networks and supportive psychotherapy techniques. Symptomatic and rehabilitative care, including well-established symptom management techniques, physical rehabilitation programs, and addressing mental health and well-being, are vital components of post-COVID-19 management. Lifestyle factors such as stress reduction, nutrition, and sleep should be incorporated into managing underlying medical conditions in post-COVID-19 patients. Regular follow-up visits and referrals to specialists are recommended to monitor the patient's progress and address specific organ system involvement or additional care needs. In summary, for the effective management of PCCs, a holistic approach should include preventive measures, patient education, supportive psychotherapy, symptomatic and rehabilitative care, medical management, counseling on lifestyle elements, and appropriate follow-up plans. However, it is crucial to stay updated with evolving guidelines and recommendations from healthcare authorities to provide the most effective and evidence-based care to post-COVID-19 patients.

Significance of Chronic Kidney Disease on Morbidity and Mortality in Hospitalized Patients With COVID-19

Background

Patients with comorbid illnesses are at risk for worse outcomes with a severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2; COVID-19). Our research examined patients with chronic kidney disease (CKD) to establish whether it remains an independent risk factor for mortality and morbidity in patients with COVID-19.

Methods

We conducted a retrospective cohort study using an electronic patient database in 2020. An observational dataset from 149 hospitals comprising a United States-based health system (HCA Healthcare) was analyzed. Hospitalized patients (N=11 086), aged 18 and above, with a COVID-19 polymerase chain reaction positive result between January 1, 2020, and September 1, 2020, were included in the initial data set.Primary outcomes were in-hospital death or discharge to hospice in patients with COVID-19. Secondary outcomes were individual components of the primary outcome including intensive care unit (ICU) admission, ventilator dependency, development of acute kidney injury (AKI), and in-hospital death. Baseline patient characteristics were recorded, including demographic variables and comorbidities.

Results

A total of 11 086 patients were included in the analysis. The study group included patients with CKD (5543 patients). Patients in the control group (5543 patients) were propensity matched for age, race, sex, and ethnicity. The primary outcome of in-hospital death or discharge to hospice was observed in 20.96% of patients with CKD compared to 11.91% of the control group with an odds ratio of 1.58 (confidence interval 1.37-1.80). ICU admission was required for 37.20% of patients in the CKD group and 21.63% of patients in the control group (P < .001). Ventilator dependency was found in 14.41% of patients in the CKD group and 8.59% of patients in the control group (P < .01). Development of AKI was seen in 5.65% of patients in the CKD group and 2.90% of patients in the control group (P < .01). A logistic regression model confirmed an independent association between underlying CKD and in-hospital death or discharge to hospice in patients with COVID-19.

Conclusion

Our study confirms an independent association between underlying CKD and poor outcomes among hospitalized patients with COVID-19, including in-hospital death or discharge to hospice.

Gastric Ischemia after SARS-CoV-2 Infection

Gastric ischemia is uncommon because the stomach has multiple collateral blood supplies. The etiology of gastric ischemia is vascular insufficiency caused by systemic hypotension, vasculitis, or disseminated thromboembolism. Mechanical causes include gastric volvulus and acute gastric distention. Uncommon as gastric ischemia is, we are the first to report a 65-year-old male who developed gastric ischemia leading to gastric pneumatosis 26 days after initial treatment for severe acute respiratory syndrome coronavirus-2 infection (SARS-CoV-2), via laparoscopic imaging. We conclude that physicians should be suspicious of gastric ischemia when the patient is infected with SARS-CoV-2 with severe abdominal pain and should proceed with medical conservative care instead of surgery.

Environmental dissemination of respiratory viruses: dynamic interdependencies of respiratory droplets, aerosols, aerial particulates, environmental surfaces, and contribution of viral re-aerosolization

During the recent pandemic of COVID-19 (SARS-CoV-2), influential public health agencies such as the World Health Organization (WHO) and the U.S. Centers for Disease Control and Prevention (CDC) have favored the view that SARS CoV-2 spreads predominantly via droplets. Many experts in aerobiology have openly opposed that stance, forcing a vigorous debate on the topic. In this review, we discuss the various proposed modes of viral transmission, stressing the interdependencies between droplet, aerosol, and fomite spread. Relative humidity and temperature prevailing determine the rates at which respiratory aerosols and droplets emitted from an expiratory event (sneezing, coughing, etc.) evaporate to form smaller droplets or aerosols, or experience hygroscopic growth. Gravitational settling of droplets may result in contamination of environmental surfaces (fomites). Depending upon human, animal and mechanical activities in the occupied space indoors, viruses deposited on environmental surfaces may be re-aerosolized (re-suspended) to contribute to aerosols, and can be conveyed on aerial particulate matter such as dust and allergens. The transmission of respiratory viruses may then best be viewed as resulting from dynamic virus spread from infected individuals to susceptible individuals by various physical states of active respiratory emissions, instead of the current paradigm that emphasizes separate dissemination by respiratory droplets, aerosols or by contaminated fomites. To achieve the optimum outcome in terms of risk mitigation and infection prevention and control (IPAC) during seasonal infection peaks, outbreaks, and pandemics, this holistic view emphasizes the importance of dealing with all interdependent transmission modalities, rather than focusing on one modality.

Pregnancy and SARS-CoV-2 infection with a focus on its vertical transmission, breastfeeding, cord blood banking, and vaccination during COVID-19 infection

The SARS-CoV-2 outbreak led to a health crisis worldwide. This infection can infect individuals, particularly pregnant women. In this review, we tried to find the possibility of vertical transmission of COVID-19 and investigate the effects of COVID-19 on pregnancy, breastfeeding, cord blood banking, and the effects of recommended vaccines on pregnant and lactating women. Keywords include COVID-19, congenital infection, SARS-CoV-2, pregnancy, and COVID-19 vaccines. Vertical transmission of SARS-CoV-2 was searched in scientific databases, such as PubMed, Google Scholar, and Scopus. The criteria for including studies in this article are the study of SARS-CoV-2 infection in pregnant women, fetuses, and neonates during pregnancy and while breastfeeding, and also the effect of COVID-19 vaccines on them. There are several conflicting results in the transmission of SARS-CoV-2 from the maternal-fetal interface. Since many neonates born from COVID-19-infected mothers had no signs of this infection, the possibility of SARS-CoV-2 congenital transmission cannot be confirmed. Also, SARS-CoV-2-infected women can breastfeed their babies if they have mild symptoms. Up till now, no adverse effect of COVID-19 vaccines has been identified on mothers, infants, and the fertility of men or women. Even so, more investigations are needed on the long-term effects of COVID-19 vaccines.

Intronic Variants of the Angiotensin-Converting Enzyme 2 Gene Modulate Plasma ACE2 Levels and Possibly Confer Protection against Severe COVID-19

Membrane-bound angiotensin-converting enzyme 2 (ACE2) receptor acts as the entry point for the novel coronavirus, SARS-CoV-2. Polymorphisms in the ACE2 gene may alter viral binding, regulate the expression of ACE2, and thus, affect disease severity. In this study, 68 COVID-19 patients with varying degrees of severity and 40 healthy controls were enrolled. The genetic landscape of the ACE2 gene was explored by whole exome sequencing of 29 individuals, and specific regions of ACE2 were analyzed for the rest of the participants via PCR, followed by barcode-tagged sequencing. The mean soluble ACE2 level in the plasma of healthy controls and patients did not vary significantly but was higher in the patient group (3.77 ± 1.55 ng/mL vs. 3.94 ± 1.42 ng/mL). Analysis of exon 1, exon 2, and exon 8 of the ACE2 gene revealed that these regions are highly conserved in our population. Investigation of exon 11 and its flanking intronic region revealed that deletions in a stretch of 18T nucleotides in the noncoding region significantly decrease ACE2 levels in plasma, as individuals harboring wild-type variants had higher plasma ACE2 levels compared to those harboring T1del, T2del, and T3del variants. However, the intronic variants were not found to be significantly associated with disease severity.

Variations in O-Glycosylation Patterns Influence Viral Pathogenicity, Infectivity, and Transmissibility in SARS-CoV-2 Variants

The highly glycosylated S protein plays a vital role in host cell invasion, making it the principal target for vaccine development. Differences in mutations observed on the spike (S) protein of SARS-CoV-2 variants may result in distinct glycosylation patterns, thus influencing immunological evasion, infectivity, and transmissibility. The glycans can mask key epitopes on the S1 protein and alter its structural conformation, allowing the virus to escape the immune system. Therefore, we comprehensively characterize O-glycosylation in eleven variants of SARS-CoV-2 S1 subunits to understand the differences observed in the biology of the variants. In-depth characterization was performed with a double digestion strategy and an efficient LC-MS/MS approach. We observed that O-glycosylation is highly conserved across all variants in the region between the NTD and RBD, whereas other domains and regions exhibit variation in O-glycosylation. Notably, omicron has the highest number of O-glycosylation sites on the S1 subunit. Also, omicron has the highest level of sialylation in the RBD and RBM functional motifs. Our findings may shed light on how differences in O-glycosylation impact viral pathogenicity in variants of SARS-CoV-2 and facilitate the development of a robust vaccine with high protective efficacy against the variants of concern.

Molecular Imaging of ACE2 Expression in Infectious Disease and Cancer

Angiotensin-converting enzyme 2 (ACE2) is a cell-surface receptor that plays a critical role in the pathogenesis of SARS-CoV-2 infection. Through the use of ligands engineered for the receptor, ACE2 imaging has emerged as a valuable tool for preclinical and clinical research. These can be used to visualize the expression and distribution of ACE2 in tissues and cells. A variety of techniques including optical, magnetic resonance, and nuclear medicine contrast agents have been developed and employed in the preclinical setting. Positron-emitting radiotracers for highly sensitive and quantitative tomography have also been translated in the context of SARS-CoV-2-infected and control patients. Together this information can be used to better understand the mechanisms of SARS-CoV-2 infection, the potential roles of ACE2 in homeostasis and disease, and to identify potential therapeutic modulators in infectious disease and cancer. This review summarizes the tools and techniques to detect and delineate ACE2 in this rapidly expanding field.

Tutorial review for peptide assays: An ounce of pre-analytics is worth a pound of cure

The recent increase in peptidomimetic-based medications and the growing interest in peptide hormones has brought new attention to the quantification of peptides for diagnostic purposes. Indeed, the circulating concentrations of peptide hormones in the blood provide a snapshot of the state of the body and could eventually lead to detecting a particular health condition. Although extremely useful, the quantification of such molecules, preferably by liquid chromatography coupled to mass spectrometry, might be quite tricky. First, peptides are subjected to hydrolysis, oxidation, and other post-translational modifications, and, most importantly, they are substrates of specific and nonspecific proteases in biological matrixes. All these events might continue after sampling, changing the peptide hormone concentrations. Second, because they include positively and negatively charged groups and hydrophilic and hydrophobic residues, they interact with their environment; these interactions might lead to a local change in the measured concentrations. A phenomenon such as nonspecific adsorption to lab glassware or materials has often a tremendous effect on the concentration and needs to be controlled with particular care. Finally, the circulating levels of peptides might be low (pico- or femtomolar range), increasing the impact of the aforementioned effects and inducing the need for highly sensitive instruments and well-optimized methods. Thus, despite the extreme diversity of these peptides and their matrixes, there is a common challenge for all the assays: the need to keep concentrations unchanged from sampling to analysis. While significant efforts are often placed on optimizing the analysis, few studies consider in depth the impact of pre-analytical steps on the results. By working through practical examples, this solution-oriented tutorial review addresses typical pre-analytical challenges encountered during the development of a peptide assay from the standpoint of a clinical laboratory. We provide tips and tricks to avoid pitfalls as well as strategies to guide all new developments. Our ultimate goal is to increase pre-analytical awareness to ensure that newly developed peptide assays produce robust and accurate results.

Macrophage-Derived Chemokine MDC/CCL22: An Ambiguous Finding in COVID-19

Macrophage-derived chemokine (MDC/CCL22) is a chemokine of the C-C subfamily. It is involved in T-cellular maturation and migration. Our previous research shows that plasma CCL22/MDC tends to show a statistically significant depletion of concentrations in acute patients and convalescents when compared to healthy donors. In the current work, we investigate existing views on MDC/CCL22 dynamics in association with various pathologies, including respiratory diseases and, specifically, COVID-19. Additionally, we present our explanations for the observed decrease in MDC/CCL22 concentrations in COVID-19. The first hypothesis we provide implies that viral products bind to MDC/CCL22 and block its activity. Another explanation for this phenomenon is based on dendritic cells population and the inhibition of their function.

Immunologic and Autoimmune-Related Sequelae of Severe Acute Respiratory Syndrome Coronavirus 2 Infection: Clinical Symptoms and Mechanisms of Disease

The COVID-19 pandemic has resulted in a significant number of people developing long-term health effects of postacute sequelae SARS-CoV-2 infection (PASC). Both acute COVID-19 and PASC are now recognized as multiorgan diseases with multiple symptoms and disease causes. The development of immune dysregulation during acute COVID-19 and PASC is of high epidemiologic concern. Both conditions may also be influenced by comorbid conditions such as pulmonary dysfunction, cardiovascular disease, neuropsychiatric conditions, prior autoimmune conditions and cancer. This review discusses the clinical symptoms, pathophysiology, and risk factors that affect both acute COVID-19 and PASC.