Mysterious Virus: A Review on Behavior and Treatment Approaches of the Novel Coronavirus, 2019-nCoV

Antiviral activity of a polysaccharide from Sargassum fusiforme against respiratory syncytial virus

This experiment examined the antiviral activity of polysaccharides from Sargassum fusiforme against respiratory syncytial virus (RSV) in vitro, including their mechanism of action and preliminary structural analysis. Four polysaccharides (SFP1, SFP2, SFP3, and SFP4) were purified from Sargassum fusiforme using a DEAE-52 cellulose column and an NW Super 150 gel column. CCK-8 and western blot were utilized to study the antiviral activities and mechanisms of the polysaccharides. Preliminary structural analysis was conducted using HPLC and NMR techniques. The findings suggest that SFP4 (120 kD) is an acidic chemical compound composed of 88.8 % total sugars, 0.13 % proteins, 10.8 % glucuronidic acids, and 21.1 % sulfates. It contains at least ten monosaccharides, primarily mannuronic acid and fucose. Among the four polysaccharides, SFP4 had the highest anti-RSV activity, with a therapeutic index (TI) exceeding 139. SFP4 exhibited noteworthy antiviral efficacy in both upper and lower respiratory cells that were infected, especially when administered as a prophylactic treatment 2 h in advance. Furthermore, SFP4 showed a dose-dependent antiviral effect, with the highest therapeutic index (TI > 320) observed at a concentration of 7.81 μg·mL-1 during the prophylactic phase. It was speculated that SFP4's antiviral effect is due to its ability to inhibit the attachment of G-proteins to cells.

Viral symptoms in children and SARS-COV-2: information for pediatric dentists for the control of transmission

The new coronavi rus, which has spread worldwide, has spiraled out of control in Brazil. The number of infected children has increased, and more Infants Special Care Units are needed to prevent deaths. This study aims to report the most common signs and symptoms in children infected by seasonal respiratory viruses and those infected by COVID-19. This knowledge is essential to educate pediatric dentists, who may contribute to identifying the difference in symptoms and notify the cases, thus preventing the spread of COVID-19. This study was carried out in a Family Health Center of Ipojuca, state of Pernambuco, Brazil, and included 54 children seen for dental emergency care. The parents provided information about the signs and symptoms of their children' s health conditions during the lockdown from March to July 2020. All children had a serological test to detect any exposure to the virus. Kolmogorov-Smirnov and Mann-Whitney tests were used to assess the distribution of the data and compare the quantitative variables between the groups. Among the study participants, 16.7% tested positive for COVID-19. The most prevalent symptoms were headache (38.9%), sneezing (35.2%), and fever (20.4%); six out of nine children with a positive test had symptoms after infection of an adult in the family. Children infected with COVID-19 showed similar clinical signs to those with negative results. Pediatric dentists should acquire knowledge to report on sick children and prevent the spread of the disease.

Plant-derived VLP: a worthy platform to produce vaccine against SARS-CoV-2

After its emergence in late 2019 SARS-CoV-2 was declared a pandemic by the World Health Organization on 11 March 2020 and has claimed more than 2.8 million lives. There has been a massive global effort to develop vaccines against SARS-CoV-2 and the rapid and low cost production of large quantities of vaccine is urgently needed to ensure adequate supply to both developed and developing countries. Virus-like particles (VLPs) are composed of viral antigens that self-assemble into structures that mimic the structure of native viruses but lack the viral genome. Thus they are not only a safer alternative to attenuated or inactivated vaccines but are also able to induce potent cellular and humoral immune responses and can be manufactured recombinantly in expression systems that do not require viral replication. VLPs have successfully been produced in bacteria, yeast, insect and mammalian cell cultures, each production platform with its own advantages and limitations. Plants offer a number of advantages in one production platform, including proper eukaryotic protein modification and assembly, increased safety, low cost, high scalability as well as rapid production speed, a critical factor needed to control outbreaks of potential pandemics. Plant-based VLP-based viral vaccines currently in clinical trials include, amongst others, Hepatitis B virus, Influenza virus and SARS-CoV-2 vaccines. Here we discuss the importance of plants as a next generation expression system for the fast, scalable and low cost production of VLP-based vaccines.

Network pharmacology, molecular docking integrated surface plasmon resonance technology reveals the mechanism of Toujie Quwen Granules against coronavirus disease 2019 pneumonia

BACKGROUND

The Coronavirus disease 2019 pneumonia broke out in 2019 (COVID-19) and spread rapidly, which causes serious harm to the health of people and a huge economic burden around the world.

PURPOSE

In this study, the network pharmacology, molecular docking and surface plasmon resonance technology (SPR) were used to explore the potential compounds and interaction mechanism in the Toujie Quwen Granules (TQG) for the treatment of coronavirus pneumonia 2019.

STUDY DESIGN

The chemical constituents and compound targets of Lonicerae Japonicae Flos, Pseudostellariae Radix, Artemisia Annua L, Peucedani Radix, Forsythiae Fructus, Scutellariae Radix, Hedysarum Multijugum Maxim, Isatidis Folium, Radix Bupleuri, Fritiliariae Irrhosae Bulbus, Cicadae Periostracum, Poria Cocos Wolf, Pseudobulbus Cremastrae Seu Pleiones, Mume Fructus, Figwort Root and Fritillariae Thunbrgii Bulbus in TQG were searched. The target name was translated to gene name using the UniProt database and then the Chinese medicine-compound-target network was constructed. Protein-protein interaction network (PPI), Gene ontology (GO) function enrichment and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis of the core targets were performed in the Metascape to predict its mechanism. The top 34 compounds in the Chinese medicine-compound-target network were docked with SARS-CoV-2 3CL enzyme and SARS--CoV--2 RNA-dependent RNA polymerase (RdRp) and then the 13 compounds with lowest affinity score were docked with angiotensin-converting enzyme 2 (ACE2), SARS-CoV-2 Spike protein and interleukin 6 to explore its interaction mechanism. Lastly, SPR experiments were done using the quercetin, astragaloside IV, rutin and isoquercitrin, which were screened from the Chinese medicine-compound-target network and molecular docking.

RESULTS

The Chinese medicine-compound-target network includes 16 medicinal materials, 111 compounds and 298 targets, in which the degree of PTGS2, TNF and IL-6 is higher compared with other targets and which are the disease target exactly. The result of GO function enrichment analysis included the response to the molecule of bacterial origin, positive regulation of cell death, apoptotic signaling pathway, cytokine-mediated signaling pathway, cytokine receptor binding and so on. KEGG pathway analysis enrichment revealed two pathways: signaling pathway- IL-17 and signaling pathway- TNF. The result of molecular docking showed that the affinity score of compounds including quercetin, isoquercitrin, astragaloside IV and rutin is higher than other compounds. In addition, the SPR experiments revealed that the quercetin and isoquercitrin were combined with SARS-CoV-2 Spike protein rather than Angiotensin-converting enzyme 2, while astragaloside IV and rutin were combined with ACE2 rather than SARS-CoV-2 Spike protein.

CONCLUSION

TQG may have therapeutic effects on COVID-19 by regulating viral infection, immune and inflammation related targets and pathways, in the way of multi-component, multi-target and multi-pathway.

Hepatitis B core-based virus-like particles: A platform for vaccine development in plants

Virus-like particles (VLPs) are a class of structures formed by the self-assembly of viral capsid protein subunits and contain no infective viral genetic material. The Hepatitis B core (HBc) antigen is capable of assembling into VLPs that can elicit strong immune responses and has been licensed as a commercial vaccine against Hepatitis B. The HBc VLPs have also been employed as a platform for the presentation of foreign epitopes to the immune system and have been used to develop vaccines against, for example, influenza A and Foot-and-mouth disease. Plant expression systems are rapid, scalable and safe, and are capable of providing correct post-translational modifications and reducing upstream production costs. The production of HBc-based virus-like particles in plants would thus greatly increase the efficiency of vaccine production. This review investigates the application of plant-based HBc VLP as a platform for vaccine production.

SARS-CoV-2: Immune Response Elicited by Infection and Development of Vaccines and Treatments

The World Health Organization (WHO) announced in March a pandemic caused by Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2). This new infectious disease was named Coronavirus Disease 19 (COVID-19), and at October 2020, more than 39,000,000 cases of SARS-CoV-2 have been detected worldwide leading to near 1,100,000 deaths. Clinically, COVID-19 is characterized by clinical manifestations, such as fever, dry cough, headache, and in more severe cases, respiratory distress. Moreover, neurological-, cardiac-, and renal-related symptoms have also been described. Clinical evidence suggests that migration of immune cells to the affected organs can produce an exacerbated release of proinflammatory mediators that contribute to disease and render the immune response as a major player during the development of the COVID-19 disease. Due to the current sanitary situation, the development of vaccines is imperative. Up to the date, 42 prototypes are being tested in humans in different clinical stages, with 10 vaccine candidates undergoing evaluation in phase III clinical trials. In the same way, the search for an effective treatment to approach the most severe cases is also in constant advancement. Several potential therapies have been tested since COVID-19 was described, including antivirals, antiparasitic and immune modulators. Recently, clinical trials with hydroxychloroquine-a promising drug in the beginning-were suspended. In addition, the Food and Drug Administration (FDA) approved convalescent serum administration as a treatment for SARS-CoV-2 patients. Moreover, monoclonal antibody therapy is also under development to neutralize the virus and prevent infection. In this article, we describe the clinical manifestations and the immunological information available about COVID-19 disease. Furthermore, we discuss current therapies under study and the development of vaccines to prevent this disease.

Impact of Corona Virus Disease 2019 on Oral- and Maxillofacial Surgery: Preliminary Results After the Curfew

INTRODUCTION

The COVID-19 pandemic affects basic health care in maxillofacial surgery (MFS) due to the shift in resources and the change in patient disorders treated during the pandemic. This paper aims to elucidate the medical and financial consequences driven by the measures for COVID-19 treatment in a tertiary care centre.

MATERIAL AND METHODS

To evaluate the impact of pandemic measures on daily routines of MFS, the surgical schedule during the first 2 weeks after the onset of the curfew (March 2020), and to compare it with the schedule of the same period of time 1 year earlier. Furthermore, postponed surgeries as well as cancelled follow-ups are listed. The loss of earning was calculated as well as the number and kind of postponed procedures.

RESULTS

The number of surgeries decreased by 45% (n = 163 in 2019 vs n = 89 in 2020), and the duration of the surgeries decreased from 94.2 minutes to 62.1 minutes. No elective surgeries, such as implantology, aesthetic surgery, or orthognathic surgery, took place. Furthermore, also trauma cases decreased from 9 to 3 cases. Considering all variables, the financial loss can be calculated as approximately 100,256.50 Euros per week.

CONCLUSION

The impact of COVID-19 on MFS is certainly of medical and economic importance and is related to the duration of the pandemic.