An updated review on pathogenic coronaviruses (CoVs) amid the emergence of SARS-CoV-2 variants: A look into the repercussions and possible solutions

SARS-CoV-2, responsible for COVID-19, shares 79% and 50% of its identity with SARS-CoV-1 and MERS-CoV, respectively. It uses the same main cell attachment and entry receptor as SARS-CoV-1, which is the ACE-2 receptor. However, key residues in the receptor-binding domain of its S-protein seem to give it a stronger affinity for the receptor and a better ability to hide from the host immune system. Like SARS-CoV-1 and MERS-CoV, cytokine storms in critically ill COVID-19 patients cause ARDS, neurological pathology, multiorgan failure, and increased death. Though many issues remain, the global research effort and lessons from SARS-CoV-1 and MERS-CoV are hopeful. The emergence of novel SARS-CoV-2 variants and subvariants raised serious concerns among the scientific community amid the emergence of other viral diseases like monkeypox and Marburg virus, which are major concerns for healthcare settings worldwide. Hence, an updated review on the comparative analysis of various coronaviruses (CoVs) has been developed, which highlights the evolution of CoVs and their repercussions.

Nanovaccines: A game changing approach in the fight against infectious diseases

The field of nanotechnology has revolutionised global attempts to prevent, treat, and eradicate infectious diseases in the foreseen future. Nanovaccines have proven to be a valuable pawn in this novel technology. Nanovaccines are made up of nanoparticles that are associated with or prepared with components that can stimulate the host's immune system. In addition to their delivery capabilities, the nanocarriers have been demonstrated to possess intrinsic adjuvant properties, working as immune cell stimulators. Thus, nanovaccines have the potential to promote rapid as well as long-lasting humoral and cellular immunity. The nanovaccines have several possible benefits, including site-specific antigen delivery, increased antigen bioavailability, and a diminished adverse effect profile. To avail these benefits, several nanoparticle-based vaccines are being developed, including virus-like particles, liposomes, polymeric nanoparticles, nanogels, lipid nanoparticles, emulsion vaccines, exomes, and inorganic nanoparticles. Inspired by their distinctive properties, researchers are working on the development of nanovaccines for a variety of applications, such as cancer immunotherapy and infectious diseases. Although a few challenges still need to be overcome, such as modulation of the nanoparticle pharmacokinetics to avoid rapid elimination from the bloodstream by the reticuloendothelial system, The future prospects of this technology are also assuring, with multiple options such as personalised vaccines, needle-free formulations, and combination nanovaccines with several promising candidates.

Immunomodulatory approaches in managing lung inflammation in COVID-19: A double-edge sword

INTRODUCTION

The novel coronavirus infectious disease 2019 (COVID-19) which is caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has emerged as a gigantic problem. The lung is the major target organ of SARS-CoV-2 and some of its variants like Delta and Omicron variant adapted in such a way that these variants can significantly damage this vital organ of the body. These variants raised a few eyebrows as the outbreaks have been seen in the vaccinated population. Patients develop severe respiratory illnesses which eventually prove fatal unless treated early.

MAIN BODY

Studies have shown that SARS-CoV-2 causes the release of pro-inflammatory cytokines such as interleukin (IL)-6, IL-1β and tumor necrosis factor (TNF)-α which are mediators of lung inflammation, lung damage, fever, and fibrosis. Additionally, various chemokines have been found to play an important role in the disease progression. A plethora of pro-inflammatory cytokines "cytokine storm" has been observed in severe cases of SARS-CoV-2 infection leading to acute respiratory distress syndrome (ARDS) and pneumonia that may prove fatal. To counteract cytokine storm-inducing lung inflammation, several promising immunomodulatory approaches are being investigated in numerous clinical trials. However, the benefits of using these strategies should outweigh the risks involved as the use of certain immunosuppressive approaches might lead the host susceptible to secondary bacterial infections.

CONCLUSION

The present review discusses promising immunomodulatory approaches to manage lung inflammation in COVID-19 cases which may serve as potential therapeutic options in the future and may prove lifesaving.

Gastrointestinal treatment-related adverse events of combined immune checkpoint inhibitors: a meta-analysis

Introduction: Combined immune checkpoint inhibitors can cause gastrointestinal adverse events. Methods: We performed a meta-analysis of pooled colonic, hepatic and pancreatic treatment-related adverse events of combined ICI. Results: 53 trials reporting treatment-related adverse events in 6581 patients. All grade diarrhea was the most common adverse event seen in 25.4% patients, followed by all grade hepatitis in nearly 13% patients and pancreatitis in nearly 7.5% patients. Conclusion: Our study provides pooled data of treatment-related adverse events from different combination immune checkpoint inhibitors use in solid tumors and demonstrates a high incidence of all grades and ≥3 grade gastrointestinal adverse events. Further studies are required to characterize these adverse events and assess their overall impact on treatment course and outcomes.

Regulatory T Cells (Tregs) and COVID-19: Unveiling the Mechanisms, and Therapeutic Potentialities with a Special Focus on Long COVID

The COVID-19 pandemic has caused havoc all around the world. The causative agent of COVID-19 is the novel form of the coronavirus (CoV) named SARS-CoV-2, which results in immune system disruption, increased inflammation, and acute respiratory distress syndrome (ARDS). T cells have been important components of the immune system, which decide the fate of the COVID-19 disease. Recent studies have reported an important subset of T cells known as regulatory T cells (Tregs), which possess immunosuppressive and immunoregulatory properties and play a crucial role in the prognosis of COVID-19 disease. Recent studies have shown that COVID-19 patients have considerably fewer Tregs than the general population. Such a decrement may have an impact on COVID-19 patients in a number of ways, including diminishing the effect of inflammatory inhibition, creating an inequality in the Treg/Th17 percentage, and raising the chance of respiratory failure. Having fewer Tregs may enhance the likelihood of long COVID development in addition to contributing to the disease's poor prognosis. Additionally, tissue-resident Tregs provide tissue repair in addition to immunosuppressive and immunoregulatory activities, which may aid in the recovery of COVID-19 patients. The severity of the illness is also linked to abnormalities in the Tregs' phenotype, such as reduced expression of FoxP3 and other immunosuppressive cytokines, including IL-10 and TGF-beta. Hence, in this review, we summarize the immunosuppressive mechanisms and their possible roles in the prognosis of COVID-19 disease. Furthermore, the perturbations in Tregs have been associated with disease severity. The roles of Tregs are also explained in the long COVID. This review also discusses the potential therapeutic roles of Tregs in the management of patients with COVID-19.

Variants of SARS-CoV-2: Influences on the Vaccines' Effectiveness and Possible Strategies to Overcome Their Consequences

The immune response elicited by the current COVID-19 vaccinations declines with time, especially among the immunocompromised population. Furthermore, the emergence of novel SARS-CoV-2 variants, particularly the Omicron variant, has raised serious concerns about the efficacy of currently available vaccines in protecting the most vulnerable people. Several studies have reported that vaccinated people get breakthrough infections amid COVID-19 cases. So far, five variants of concern (VOCs) have been reported, resulting in successive waves of infection. These variants have shown a variable amount of resistance towards the neutralising antibodies (nAbs) elicited either through natural infection or the vaccination. The spike (S) protein, membrane (M) protein, and envelope (E) protein on the viral surface envelope and the N-nucleocapsid protein in the core of the ribonucleoprotein are the major structural vaccine target proteins against COVID-19. Among these targets, S Protein has been extensively exploited to generate effective vaccines against COVID-19. Hence, amid the emergence of novel variants of SARS-CoV-2, we have discussed their impact on currently available vaccines. We have also discussed the potential roles of S Protein in the development of novel vaccination approaches to contain the negative consequences of the variants' emergence and acquisition of mutations in the S Protein of SARS-CoV-2. Moreover, the implications of SARS-CoV-2's structural proteins were also discussed in terms of their variable potential to elicit an effective amount of immune response.

Efficacy of topical hemostatic agents in malignancy-related GI bleeding: a systematic review and meta-analysis

BACKGROUND AND AIMS

Despite advances in endoscopic therapies, malignancy-related GI bleeding remains difficult to manage with high rates of treatment failure and rebleeding. Topical hemostatic agents (THAs) are easier to apply to the wide bleeding surface of tumors. We conducted this systematic review and meta-analysis to evaluate the efficacy of THAs in malignancy-related GI bleeding.

METHODS

We conducted a comprehensive search of multiple electronic databases to identify studies reporting on the use of THAs in malignancy-related GI bleeding. The primary outcome was the achievement of hemostasis; secondary outcomes were early rebleeding (≤3 days), delayed rebleeding (>3 days), aggregate rebleeding, all-cause mortality, and GI bleeding-related mortality. A meta-analysis of proportions was done for all outcomes.

RESULTS

Out of 355 citations, 16 studies with 530 patients were included. Primary hemostasis was achieved in 94.1% (95% confidence interval [CI], 91.5-96.0). Early rebleeding was seen in 13.9% (95% CI, 9.7-19.4) and delayed rebleeding in 11.4% (95% CI, 5.8-21.1). Aggregate rebleeding was seen in 24.2% (95% CI, 18.5-31.0). All-cause mortality was 33.1% (95% CI, 23.7-44.0), whereas GI bleeding-related mortality occurred in 5.9% (95% CI, 2.2%-14.8).

CONCLUSIONS

THAs are highly effective for achieving primary hemostasis in malignancy-related GI bleeding. It should be considered as an alternative to traditional endotherapy methods in malignancy-related GI bleeding. Future studies should be designed to evaluate its efficacy and safety as a primary method of hemostasis as compared with traditional endotherapy measures.

Spectrum, Outcomes, and Mortality Predictors of Acute Kidney Injury among Non-COVID-19 Patients during COVID-19 Pandemic: Data from Four Intensive Care Units

Introduction

The data of acute kidney injury (AKI), that is, community-acquired AKI (CA-AKI) and hospital-acquired AKI (HA-AKI) among non-COVID patients from intensive care units (ICU) during the coronavirus disease-2019 (COVID-19) pandemic are scarce. We planned to study the change in the profile of such patients compared to the pre-pandemic era.

Materials and methods

This prospective observational study was conducted at four ICUs dealing with non-COVID patients at a government hospital in North India, and was aimed at assessing outcomes, and mortality predictors of AKI among non-COVID patients during the COVID-19 pandemic. Renal and patient survival at ICU transfer-out and hospital discharge, ICU and hospital stay duration, mortality predictors, and dialysis requirement at discharge were evaluated. The current or previous COVID-19 infection, previous AKI or chronic kidney disease (CKD), organ donors, and organ transplant patients were excluded.

Results

Among the 200 non-COVID-19 AKI patients, diabetes mellitus (DM), primary hypertension, and cardiovascular diseases were the predominant comorbidities in descending order. The commonest cause of AKI was severe sepsis, followed by systemic infections and post-surgery patients. Dialysis requirements at ICU admission during ICU stay and above 30 days were seen in 20.5, 47.5, and 6.5% of patients, respectively. Incidence of CA-AKI and HA-AKI was 1.24:1, whereas dialysis requirement above 30 days was 0.85:1, respectively. The 30-day mortality was 42%. Hepatic dysfunction [hazard ratio (HR): 3.471], septicemia (HR: 3.342), age above 60 years (HR: 4.000), higher sequential organ failure assessment (SOFA) score (HR: 1.107; p = 0.001), anemia (p = 0.003), and low serum iron (p = 0.001) were important mortality predictors in AKI.

Conclusion

Compared to the pre-COVID era, CA-AKI was more common than HA-AKI due to restricted elective surgeries during the COVID-19 pandemic. Acute kidney injury with multiorgan involvement and hepatic dysfunction, elderly age with higher SOFA score and sepsis were predictors of adverse renal and patient outcomes.

How to cite this article

Singh B, Dogra PM, Sood V, Singh V, Katyal A, Dhawan M, et al. Spectrum, Outcomes, and Mortality Predictors of Acute Kidney Injury among Non-COVID-19 Patients during COVID-19 Pandemic: Data from Four Intensive Care Units. Indian J Crit Care Med 2023;27(2):119-126.

Prophylactic and therapeutic insights into trained immunity: A renewed concept of innate immune memory

Trained immunity is a renewed concept of innate immune memory that facilitates the innate immune system to have the capacity to remember and train cells via metabolic and transcriptional events to enable them to provide nonspecific defense against the subsequent encounters with a range of pathogens and acquire a quicker and more robust immune response, but different from the adaptive immune memory. Reversing the epigenetic changes or targeting the immunological pathways may be considered potential therapeutic approaches to counteract the hyper-responsive or hypo-responsive state of trained immunity. The efficient regulation of immune homeostasis and promotion or inhibition of immune responses is required for a balanced response. Trained immunity-based vaccines can serve as potent immune stimuli and help in the clearance of pathogens in the body through multiple or heterologous effects and confer protection against nonspecific and specific pathogens. This review highlights various features of trained immunity and its applications in developing novel therapeutics and vaccines, along with certain detrimental effects, challenges as well as future perspectives.

Regulatory T cells (Tregs) and their therapeutic potential against autoimmune disorders - Advances and challenges

Autoimmune diseases are caused when immune cells act against self-protein. This biological self-non-self-discrimination phenomenon is controlled by a distinct group of lymphocytes known as regulatory T cells (Tregs), which are key inflammatory response regulators and play a pivotal role in immune tolerance and homeostasis. Treg-mediated robust immunosuppression provides self-tolerance and protection against autoimmune diseases. However, once this system fails to operate or poorly operate, it leads to an extreme situation where immune system reacts against self-antigens and destroys host organs, thus causing autoimmune diseases. Tregs can target both innate and adaptive immunity via modulating multiple immune cells such as neutrophils, monocytes, antigen-presenting cells, B cells, and T cells. This review highlights the Treg-mediated immunosuppression, role of several markers and their interplay during Treg development and differentiation, and advances in therapeutic aspects of Treg cells to reduce severity of autoimmunity-related conditions along with emphasizing limitations and challenges of their usages.

Disease History, Pathogenesis, Diagnostics, and Therapeutics for Human Monkeypox Disease: A Comprehensive Review

The monkeypox disease is a zoonotic-infectious disease that transmits between animals and humans. It is caused by a double-stranded DNA virus belonging to the Orthopoxvirus genus that is closely related to the variola virus -the causative agent of smallpox. Although monkeypox infections were endemic to Western and Central Africa, the newly emerging monkeypox outbreak spread to more than 90 non-African countries. With the exception of the PCR-confirmed case of a return from Nigeria to the United Kingdom, the ongoing outbreak is largely unrelated to travel. In the most recent wave, cases are characteristically males in their thirties. Risk factors include close and particularly sexual contact with an infected person, and contact with fomites, infected animals or aerosolized-infectious material. Clinical diagnosis of monkeypox is confirmed with nucleic-acid amplification testing of samples originating from vesicles or genital lesions and using real-time or conventional PCR. Other methods, such as electron microscopy, immunohistochemistry, and virus culture are costly and time-consuming. In addition to timely diagnosis and contact tracing, restrictive measures to limit spread, such as isolation of infected patients, preventing contact with wild animals, and isolation of animals suspected to be viral reservoirs have shown promise. Although there are no specific treatments for monkeypox disease, the experience with smallpox suggests that the vaccinia vaccine, cidofovir, tecovirimat, and vaccinia immune globulin (IVG) may be beneficial for monkeypox treatment. In this review, we provide an update on the human-monkeypox disease with a special emphasis on its pathogenesis, prevention, diagnostics, and therapeutic measures.

Delta variant (B.1.617.2) of SARS-CoV-2: Mutations, impact, challenges and possible solutions

Since commencement of COVID-19 pandemic, several SARS-CoV-2 variants have emerged amid containment efforts via vaccination. The Delta variant (B.1.617.2), discovered in October 2020, was designated as a VOC by the WHO on May 11, 2021. The enhanced transmissibility of Delta variant has been associated with critical mutations such as D614G, L452R, P681R, and T478K in the S-protein. The increased affinity of the S-protein and ACE2 has been postulated as a key reason for decreased vaccine efficacy. As per evidence, the Delta variant possesses increased transmissibility and decreased vaccine efficacy compared to other VOCs like Alpha and Beta. This has led to concerns regarding the acquisition of novel mutations in the Delta variant and outbreaks in vulnerable communities, including vaccinated people. In this mini-review of Delta variant, we have explained its evolution and characteristics, the impact of spike mutations on infectivity and immune evasion, and measures to combat future outbreaks.

Omicron variant (B.1.1.529) and its sublineages: What do we know so far amid the emergence of recombinant variants of SARS-CoV-2?

Since the start of the COVID-19 pandemic, numerous variants of SARS-CoV-2 have been reported worldwide. The advent of variants of concern (VOCs) raises severe concerns amid the serious containment efforts against COVID-19 that include physical measures, pharmacological repurposing, immunization, and genomic/community surveillance. Omicron variant (B.1.1.529) has been identified as a highly modified, contagious, and crucial variant among the five VOCs of SARS-CoV-2. The increased affinity of the spike protein (S-protein), and host receptor, angiotensin converting enzyme-2 (ACE-2), due to a higher number of mutations in the receptor-binding domain (RBD) of the S-protein has been proposed as the primary reason for the decreased efficacy of majorly available vaccines against the Omicron variant and the increased transmissible nature of the Omicron variant. Because of its significant competitive advantage, the Omicron variant and its sublineages swiftly surpassed other variants to become the dominant circulating lineages in a number of nations. The Omicron variant has been identified as a prevalent strain in the United Kingdom and South Africa. Furthermore, the emergence of recombinant variants through the conjunction of the Omicron variant with other variants or by the mixing of the Omicron variant's sublineages/subvariants poses a major threat to humanity. This raises various issues and hazards regarding the Omicron variant and its sublineages, such as an Omicron variant breakout in susceptible populations among fully vaccinated persons. As a result, understanding the features and genetic implications of this variant is crucial. Hence, we explained in depth the evolution and features of the Omicron variant and analyzed the repercussions of spike mutations on infectiousness, dissemination ability, viral entry mechanism, and immune evasion. We also presented a viewpoint on feasible strategies for precluding and counteracting any future catastrophic emergence and spread of the omicron variant and its sublineages that could result in a detrimental wave of COVID-19 cases.

Modern drug discovery applications for the identification of novel candidates for COVID-19 infections

In early December 2019, a large pneumonia epidemic occurred in Wuhan, China. The World Health Organization is concerned about the outbreak of another coronavirus with the powerful, rapid, and contagious transmission. Anyone with minor symptoms like fever and cough or travel history to contaminated places might be suspected of having COVID-19. COVID-19 therapy focuses on treating the disease's symptoms. So far, no such therapeutic molecule has been shown effective in treating this condition. So the treatment is mostly supportive and plasma. Globally, numerous studies and researchers have recently started fighting this virus. Vaccines and chemical compounds are also being investigated against infection. COVID-19 was successfully diagnosed using RNA detection and very sensitive RT-PCR (reverse transcription-polymerase chain reaction). The evolution of particular vaccinations is required to reduce illness severity and spread. Numerous computational analyses and molecular docking have predicted various target compounds that might stop this condition. This paper examines the main characteristics of coronavirus and the computational analyses necessary to avoid infection.

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Importance of advanced genome sequencing in analyzing the sequential change in DNA and RNA due to SARS-CoV-2 genome.

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Lead Identification studies with computer drug-aided design.

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Prevalence of some flavonoid glycosides in medicinal plants which have potential protective effects against COVID-19 infections.

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Docking studies with alkaloids, vanillin derivatives and their actions suggest possible SARS- CoV-2 inhibition.

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Modeling studies outcomes about ligand-based and structure based activity.

Hepatitis E virus in pigs and the environment: An updated review of public health concerns

Hepatitis E virus (HEV) is an important public health problem and is responsible for both acute and chronic viral hepatitis. Public health implications of HEV are derived from its transmission route, either water-borne or food-borne, and its zoonotic potential. Not only in developing countries, but HEV cases are also found in a high number in developed countries. The spread of HEV to the environment might pollute surface waters, which could act as the source of infection for both humans and animals. Identification of the virus in animal products suggests the circulation of HEV within water and food chains. High seroprevalence and circulation of HEV in livestock, in particular pigs, as well as in environmental samples warrants further investigation into pig markets. HEV virulence in different environments and meat supply chains could shed light on the possible sources of infection in humans and the degree of occupational risk. The purpose of this review is to discuss HEV infections with an emphasis on livestock- and environment-related risk factors, and food-borne, water-borne, and zoonotic transmissions.

Comparative overview of emerging RNA viruses: Epidemiology, pathogenesis, diagnosis and current treatment

From many decades, emerging infections have threatened humanity. The pandemics caused by different CoVs have already claimed and will continue to claim millions of lives. The SARS, Ebola, MERS epidemics and the most recent emergence of COVID-19 pandemic have threatened populations across borders. Since a highly pathogenic CoV has been evolved into the human population in the twenty-first century known as SARS, scientific advancements and innovative methods to tackle these viruses have increased in order to improve response preparedness towards the unpredictable threat posed by these rapidly emerging pathogens. Recently published review articles on SARS-CoV-2 have mainly focused on its pathogenesis, epidemiology and available treatments. However, in this review, we have done a systematic comparison of all three CoVs i.e., SARS, MERS and SARS-CoV-2 along with Ebola and Zika in terms of their epidemiology, virology, clinical features and current treatment strategies. This review focuses on important emerging RNA viruses starting from Zika, Ebola and the CoVs which include SARS, MERS and SARS-CoV-2. Each of these viruses has been elaborated on the basis of their epidemiology, virulence, transmission and treatment. However, special attention has been given to SARS-CoV-2 and the disease caused by it i.e., COVID-19 due to current havoc caused worldwide. At the end, insights into the current understanding of the lessons learned from previous epidemics to combat emerging CoVs have been described. The travel-related viral spread, the unprecedented nosocomial outbreaks and the high case-fatality rates associated with these highly transmissible and pathogenic viruses highlight the need for new prophylactic and therapeutic actions which include but are not limited to clinical indicators, contact tracing, and laboratory investigations as important factors that need to be taken into account in order to arrive at the final conclusion.

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Recently published review articles on SARS-CoV-2 have mainly focused on its pathogenesis, epidemiology and available treatments.

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The pandemics caused by different CoVs have already claimed and will continue to claim millions of lives.

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This review focuses on important emerging RNA viruses starting from Zika, Ebola and the CoVs which include SARS, MERS and SARS-CoV-2.

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Globally, numerous studies and researchers have recently started fighting this virus.

Strengthening vaccines and medicines manufacturing capabilities in Africa: challenges and perspectives

Africa carries a high burden of infectious diseases. Every year, millions of Africans contract tuberculosis, malaria, and many other diseases. Malaria kills hundreds of thousands of children under the age of five years annually. More than 11,000 people died during the 2014–2016 Ebola outbreak in West Africa; still, occasional cases of Ebola, as well as monkeypox, periodically appear in the Democratic Republic of Congo. Since most of the African countries gained their independence during the 1960s, the continent has relied heavily on the outside world for diagnostics, medicines, vaccines, personal protective equipment, and other medical supplies. Africa consumes nearly 25% of the globally produced vaccines but imports 99% and 95% of its vaccines and medicines, respectively. The 55 African countries were not able to ensure the health of 1.3 billion Africans during the COVID‐19 pandemic but had to rely on other global initiatives and other countries for help and support. However, the pandemic and the shortage of vaccines may have been the much‐needed trigger for this situation to change. “When misfortunes increase, they erase each other.” Naguib Mahfouz (1911–2006).

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.

Gastrointestinal adverse effects of combined checkpoint inhibitors: A systematic review and meta-analysis

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Background: Combined immune checkpoint inhibitors (ICPI) have revolutionized treatment of solid tumors. Their use can lead to treatment-related adverse events (TRAEs) resulting in hospital admissions, treatment discontinuation and increased morbidity. We aim to evaluate gastrointestinal (GI) TRAEs of different combination ICPI. Methods: A comprehensive search of multiple databases from inception to October 2021 was performed. Phase 2 and 3 trials assessing safety and efficacy of combined ICPI in solid tumors were included. Trials reporting concurrent use of chemotherapy, immunosuppressants, targeted therapy, or sequential ICPI therapy were excluded. Primary outcome was pooled luminal, hepatic and pancreatic TRAEs. A meta-analysis of proportions was done for outcomes using a random-effects model. I2 % was used to assess heterogeneity. Results: Out of 3696 citations screened, 53 trials reporting TRAEs in 6186 patients were included. Data from 41 study arms of 35 trials in nivolumab plus ipilimumab (N+I), 15 study arms of 15 trials in durvalumab plus tremelimumab (D+T), 4 study arms of 3 trials in pembrolizumab plus ipilimumab (P+I). The most common indications for combined ICPI were melanoma (26.4%) and lung cancer (24.5%). Pooled GI TRAE rates from the D+T, P+I and two different dosing combinations of N+I are shown in the table. Conclusions: Our study provides pooled data of TRAEs from different combination ICPI use in solid tumors and demonstrates high incidence of all grades and ≥ 3 GI TRAEs. Combined ICPI related TRAEs should be recognized early, as it may require treatment discontinuation. Further studies are required to assess overall impact of TRAEs on treatment course and outcomes.[Table: see text]

Zoonotic diseases of fish and their prevention and control

Fish and aquatic-derived zoonotic diseases have caused considerable problems in the aquaculture industry and fishery worldwide. In particular, zoonotic diseases can pose widespread threats to humans. With the world’s growing population and potential global trade of aquaculture and fish, the risk of environmental contamination and development of fish and aquatic-derived zoonoses in humans are increasing. The important causes of zoonoses include bacteria, parasites, viruses, and fungi. The zoonotic bacterial agents are divided into two main groups: Gram-positive (Mycobacteriaceae, Streptococcaceae, Erysipelothricaceae families) and Gram-negative (Aeromonadaceae, Vibrionaceae, Pseudomondaceae, Enterobacteriaceae, and Hafniaceae families). The premier parasitic agents include cestodes (tapeworm; e.g. Diphyllobothrium spp.), trematodes (fluke; e.g. Opisthorchis spp.), and nematodes (round worm; e.g. Anisakis spp.). In addition, protozoan organisms such as Cryptosporidium spp. are also considered fish-derived zoonotic pathogens. Two groups of fish-associated fungi causing basidiobolomycosis and sporotrichosis also pose a zoonotic risk for humans. The majority of the fish-derived zoonotic diseases are transmitted to humans mainly via the consumption of improperly cooked or raw fish or fish products. Therefore, the incidence of zoonotic diseases can be reduced by properly processing fish and fish products, e.g. by thermal (heat/freezing) treatment. The prevalence of zoonotic agents in fishes varies seasonally and should be regularly monitored to evaluate the prevalence of pathogens in both wild and cultured fish populations. This review focuses on the fish zoonotic agents/diseases and their control and prevention.

Swine coronaviruses (SCoVs) and their emerging threats to swine population, inter-species transmission, exploring the susceptibility of pigs for SARS-CoV-2 and zoonotic concerns

Swine coronaviruses (SCoVs) are one of the most devastating pathogens affecting the livelihoods of farmers and swine industry across the world. These include transmissible gastroenteritis virus (TGEV), porcine epidemic diarrhea virus (PEDV), porcine respiratory coronavirus (PRCV), porcine hemagglutinating encephalomyelitis virus (PHEV), swine acute diarrhea syndrome coronavirus (SADS-CoV), and porcine delta coronavirus (PDCoV). Coronaviruses infect a wide variety of animal species and humans because these are having single stranded-RNA that accounts for high mutation rates and thus could break the species barrier. The gastrointestinal, cardiovascular, and nervous systems are the primary organ systems affected by SCoVs. Infection is very common in piglets compared to adult swine causing high mortality in the former. Bat is implicated to be the origin of all CoVs affecting animals and humans. Since pig is the only domestic animal in which CoVs cause a wide range of diseases; new coronaviruses with high zoonotic potential could likely emerge in the future as observed in the past. The recently emerged severe acute respiratory syndrome coronavirus virus-2 (SARS-CoV-2), causing COVID-19 pandemic in humans, has been implicated to have animal origin, also reported from few animal species, though its zoonotic concerns are still under investigation. This review discusses SCoVs and their epidemiology, virology, evolution, pathology, wildlife reservoirs, interspecies transmission, spill-over events and highlighting their emerging threats to swine population. The role of pigs amid ongoing SARS-CoV-2 pandemic will also be discussed. A thorough investigation should be conducted to rule out zoonotic potential of SCoVs and to design appropriate strategies for their prevention and control.

Assessing the risks associated with the emergence of Florona and possible preventive measures

The emergence of novel variants of SARS-CoV-2, especially the VOCs (variants of concern), has been considered a severe threat amid the mighty efforts of various nations to contain the negative repercussions of the COVID-19 pandemic caused by SARS-CoV-2. This article is protected by copyright. All rights reserved.

Immunomodulatory effects of zinc and its impact on COVID-19 severity

The COVID-19 pandemic has led to severe financial, clinical, and societal repercussions and imposed more pressure on the healthcare system of many nations. COVID-19 impacts the immune system by causing a systemic inflammatory reaction, often known as cytokine release syndrome (CRS). COVID-19 patients had elevated levels of pro-inflammatory cytokines and chemokines. In this context, many dietary interventions have been utilized to mitigate the adverse effects of COVID-19 by regulating the excessive secretion of cytokines and chemokines. Zinc, an anti-inflammatory and antioxidant mineral in food with a well-established role in immunity, is now being employed in several clinical studies against COVID-19. Zn deficiency has been correlated with the increased production of pro-inflammatory cytokines. As a result, we will summarise zinc's immunomodulatory effects in this article. We will investigate how zinc deficiency might contribute to a poor prognosis of COVID-19 disease by altering the release of particular cytokines.

Antioxidant effects of seaweeds and their active compounds on animal health and production - A Review

Natural antioxidants applied as feed additives can improve not only animals’ health and overall performance but also increase their resistance to environmental stress such as heat stress, bad housing conditions, diseases, etc. Marine organisms, for example seaweeds – red, brown, and green macroalgae contain a plethora of biologically active substances, including phenolic compounds, polysaccharides, pigments, vitamins, micro- and macroelements, and proteins known for their antioxidant activity, which can help in the maintenance of appropriate redox status in animals and show pleiotropic effects for enhancing good health, and productivity. The dysregulated production of free radicals is a marked characteristic of several clinical conditions, and antioxidant machinery plays a pivotal role in scavenging the excessive free radicals, thereby preventing and treating infections in animals. Supplementation of seaweeds to animal diet can boost antioxidant activity, immunity, and the gut environment. Dietary supplementation of seaweeds can also enhance meat quality due to the deposition of marine-derived antioxidant components in muscles. The use of natural antioxidants in the meat industry is a practical approach to minimize or prevent lipid oxidation. However, overconsumption of seaweeds, especially brown macroalgae, should be avoided because of their high iodine content. An important point to consider when including seaweeds in animal feed is their variable composition which depends on the species, habitat, location, harvest time, growing conditions such as nutrient concentration in water, light intensity, temperature, etc. This review highlights the beneficial applications of seaweeds and their extracted compounds, which have antioxidant properties as feed additives and impact animal health and production.

COVID-19 intranasal vaccines: current progress, advantages, prospects, and challenges

Multiple vaccines have recently been developed, and almost all the countries are presently vaccinating their population to tackle the COVID-19 pandemic. Most of the COVID-19 vaccines in use are administered via intramuscular (IM) injection, eliciting protective humor and cellular immunity. COVID-19 intranasal (IN) vaccines are also being developed that have shown promising ability to induce a significant amount of antibody-mediated immune response and a robust cell-mediated immunity as well as hold the added ability to stimulate protective mucosal immunity along with the additional advantage of the ease of administration as compared to IM injected vaccines. By inducing secretory IgA antibody responses specifically in the nasal compartment, the intranasal SARS-CoV-2 vaccine can prevent virus infection, replication, shedding, and disease development, as well as possibly limits virus transmission. This article highlights the current progress, advantages, prospects, and challenges in developing intranasal COVID-19 vaccines for countering the ongoing pandemic.

Olfactory dysfunction as a post-infectious symptom of SARS-CoV-2 infection

The unexpected onset smell and taste disability was being recognized as a COVID-19 related symptom. Loss of smell might occur alone or be followed by other COVID-19 symptoms, such as a dry cough, fever, headache, and shortness of breath. Other virus infections have been linked to anosmia (parainfluenza, rhinovirus, SARS, and others), affecting up to 20% of the adult population, which is much less common than SARS-CoV-2 infection. A hypothesis about the pathophysiology of post-infectious olfactory loss is that viruses could make an inflammatory response of the nasal mucosa or directly damage the olfactory neuroepithelium. However, in patients with COVID-19, loss of smell may occur without other rhino logic symptoms or suggestive nasal inflammation. According to evidence, anosmia-related SARS-CoV-2 could be a new viral syndrome unique to COVID-19. Furthermore, through experimental intranasal inoculation in mice, SARS-CoV-2 can be inoculated into the olfactory neural circuitry. This disease has not had the required focus, most likely because it is not life-threatening in and of itself. Though patients' quality of living is significantly reduced as their olfactory ability is lost, resulting in lowering and inadequate appetite, excessive or unbalanced food consumption, as well as an overall sense of insecurity. This review aims to give a quick overview of the latest epidemiological research, pathological mechanisms for the dysfunction of smell, and taste in patients infected with SARS-CoV-2. In addition, the initial diagnosis and treatment options for dysfunction are also discussed.

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The pathological mechanism of SARS-CoV-2 infection in olfactory dysfunction.

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Pathognomonic symptoms of sinonasal impairment in COVID-19 patients.

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Treatment of olfactory dysfunction after SARS-CoV-2 infection.

Coagulação por plasma de argônio como adjuvante à curetagem estendida em tumores de células gigantes do osso: Um estudo de 50 casos

Objetivo A curetagem estendida com adjuvantes de tumores de células gigantes do osso está associada a uma menor taxa de recidiva da neoplasia e à preservação da articulação adjacente. Este estudo foi feito para estimar a taxa de recidiva e o resultado funcional após o uso de plasma de argônio como adjuvante à curetagem estendida.

Métodos Cinquenta pacientes com tumores de células gigantes que atendiam a todos os critérios de inclusão foram selecionados para o estudo e submetidos à curetagem estendida com broca de alta velocidade e fotocoagulação com plasma de argônio entre julho de 2016 e janeiro de 2019. À consulta de acompanhamento, os pacientes foram avaliados quanto a quaisquer queixas de dor e sinais como sensibilidade, aumento local da temperatura e diminuição da amplitude de movimento da articulação adjacente. Radiologicamente, os pacientes foram avaliados quanto à presença de qualquer aumento de radiotransparência ao redor do manto de cimento e incorporação do enxerto subarticular. O questionário Musculoskeletal Tumor Society Score (MSTS) foi administrado aos pacientes e a amplitude de movimentação da articulação adjacente foi comparada à articulação contralateral.

Resultados Quatro pacientes apresentaram recidiva, o que corresponde a uma taxa de 8%. Seis meses após a cirurgia, 26 de 28 pacientes com tumor no membro inferior tinham capacidade de sustentação de peso de grau 5 e amplitude de movimento comparável à articulação saudável contralateral, com pontuação MSTS média de 27 (intervalo de 18 a 30).

Conclusão A curetagem estendida de tumores de células gigantes com coagulação por plasma de argônio está associada a baixas taxas de recidiva da neoplasia; é uma modalidade eficaz no tratamento desses tumores e o resultado funcional é comparável ao do membro saudável.

Convalescent plasma therapy against the emerging SARS-CoV-2 variants: Delineation of the potentialities and risks

Coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) has resulted in a catastrophic pandemic and severely impacted people's livelihoods worldwide. In addition, the emergence of SARS-CoV-2 variants has posed a severe threat to humankind. Due to the dearth of therapeutic options during the commencement of the pandemic, convalescent plasma therapy (CPT) played a significant part in the management of patients with severe form of COVID-19. Several recent studies have proposed various protective effects of CPT, such as antiviral, anti-inflammatory, anti-thrombotic, and immunomodulatory actions, curtailing the devastating consequences of the SARS-CoV-2 infection. On the contrary, several clinical studies have raised some serious concerns about the effectiveness and reliability of CPT in the management of patients with COVID-19. The protective effects of CPT in severely ill patients are yet to be proved. Moreover, the emergence of SARS-CoV-2 variants has raised concerns about the effectiveness of CPT against COVID-19. Therefore, to establish concrete evidence of the efficacy of CPT and adjudicate its inclusion in the management of COVID-19, an updated review of present literature is required, which could help in the development of an efficient therapeutic regimen to treat COVID-19 amid the emergence of new viral variants.

Comparative pathology, molecular pathogenicity, immunological features, and genetic characterization of three highly pathogenic human coronaviruses (MERS-CoV, SARS-CoV, and SARS-CoV-2)

The last two decades have witnessed the emergence of three deadly coronaviruses (CoVs) in humans: severe acute respiratory syndrome coronavirus (SARS-CoV), Middle East respiratory syndrome coronavirus (MERS-CoV), and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). There are still no reliable and efficient therapeutics to manage the devastating consequences of these CoVs. Of these, SARS-CoV-2, the cause of the currently ongoing coronavirus disease 2019 (COVID-19) pandemic, has posed great global health concerns. The COVID-19 pandemic has resulted in an unprecedented crisis with devastating socio-economic and health impacts worldwide. This highlights the fact that CoVs continue to evolve and have the genetic flexibility to become highly pathogenic in humans and other mammals. SARS-CoV-2 carries a high genetic homology to the previously identified CoV (SARS-CoV), and the immunological and pathogenic characteristics of SARS-CoV-2, SARS-CoV, and MERS contain key similarities and differences that can guide therapy and management. This review presents salient and updated information on comparative pathology, molecular pathogenicity, immunological features, and genetic characterization of SARS-CoV, MERS-CoV, and SARS-CoV-2; this can help in the design of more effective vaccines and therapeutics for countering these pathogenic CoVs.

Modulation of host epigenome by coronavirus infections and developing treatment modalities for COVID-19 beyond genetics

The recent Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2) outbreak has resulted in coronavirus disease 2019 (COVID-19) pandemic worldwide, affecting millions of lives. Although vaccines are presently made available, and vaccination drive is in progress to immunize a larger population; still the risk of SARS-CoV-2 infection and related mortality is persistent amid threats of the third wave of the ongoing pandemic. In the scenario of unavailability of robust and efficient treatment modalities, it becomes essential to understand the mechanism of action of the virus and deeply study the molecular mechanisms (both at the virus level and the host level) underlying the infection processes. Recent studies have shown that coronaviruses (CoVs) cause-specific epigenetic changes in the host cells to create a conducive microenvironment for replicating, assembling, and spreading. Epigenetic mechanisms can contribute to various aspects of the SARS-CoV-2 multiplication cycle, like expressing cytokine genes, viral receptor ACE2, and implicating different histone modifications. For SARS-CoV-2 infection, viral proteins are physically associated with various host proteins resulting in numerous interactions between epigenetic enzymes (i.e., histone deacetylases, bromodomain-containing proteins). The involvement of epigenetic mechanisms in the virus life cycle and the host immune responses to control infection result in epigenetic factors recognized as emerging prognostic COVID-19 biomarkers and epigenetic modulators as robust therapeutic targets to curb COVID-19. Therefore, this narrative review aimed to summarize and discuss the various epigenetic mechanisms that control gene expression and how these mechanisms are altered in the host cells during coronavirus infection. We also discuss the opportunities to exploit these epigenetic changes as therapeutic targets for SARS-CoV-2 infection. Epigenetic alterations and regulation play a pivotal role at various levels of coronavirus infection: entry, replication/transcription, and the process of maturation of viral proteins. Coronaviruses modulate the host epigenome to escape the host immune mechanisms. Therefore, host epigenetic alterations induced by CoVs can be considered to develop targeted therapies for COVID-19.