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| The first electron microscope being carefully checked by Ernst Ruska (right), as Max Knoll (left) keenly observed in 1931.
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The advancement of medicine owes in large measure to a German engineer Ernst Ruska, whose invention of transmission electron microscope in 1931 won him the 1986 Nobel Prize in Physics, when it comes to infectious diseases. Encouraged by his physician brother Helmut Ruska to use the prototype instrument for the study of viruses, the course of virolo...
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Context 1
... published the scientific principle in 1932. 3 Thus was born the electron microscope (Figure 1). But then the resolving power was no better than that of a light microscope, and thus had no practical value. ...
Context 2
... amino acids in the RBD determines the receptor-binding affinity for CoVs, although the amino acid in each species is highly variable. For instance, SARS-CoVs (Figure 10) and Human CoV-NL63 are known to have high affinity for angiotensin -converting enzyme 2 (ACE2) in humans. But for specific binding to ACE2 receptor, they use different amino acids. ...
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Background
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Many viruses, such as coronaviruses, tend to spread airborne inside water microdroplets. Evaporation of the microdroplets may result in a reduction of their contagiousness. However, the evaporation of small droplets is a complex process involving mass and heat transfer, diffusion, convection and solar radiation absorption. Virological studies indic...
Objectives
To determine the variation in SARS-CoV-2 seroprevalence in school children and the relationship with self-reported symptoms.
Design
Baseline measurements of a longitudinal cohort study ( Ciao Corona ) from June to July 2020.
Setting
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Objective The coronavirus disease 2019 (COVID-19) is a pandemic viral disease, caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The impact of the disease among the obstetric population remains unclear, and the study of the placenta can provide valuable information. Adequate sampling of the placental tissue can help characteri...
Citations
... This protein is a multifunctional molecular machine that is released from the virus in the form of a crown [38]. A single-pass anchor, a short intracellular tail, and S1 and S2 subunits constitute the three structural components of the S protein [39,40]. S1, which binds to the host ACE2 receptor, and S2, which mediates the fusion of the viral cell membrane with the host [41,42]. ...
Coronavirus disease 2019 (COVID-19) is caused by a new member of the Coronaviridae family known as severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). There are structural and non-structural proteins (NSPs) in the genome of this virus. S, M, H, and E proteins are structural proteins, and NSPs include accessory and replicase proteins. The structural and NSP components of SARS-CoV-2 play an important role in its infectivity, and some of them may be important in the pathogenesis of chronic diseases, including cancer, coagulation disorders, neurodegenerative disorders, and cardiovascular diseases. The SARS-CoV-2 proteins interact with targets such as angiotensin-converting enzyme 2 (ACE2) receptor. In addition, SARS-CoV-2 can stimulate pathological intracellular signaling pathways by triggering transcription factor hypoxia-inducible factor-1 (HIF-1), neuropilin-1 (NRP-1), CD147, and Eph receptors, which play important roles in the progression of neurodegenerative diseases like Alzheimer's disease, epilepsy, and multiple sclerosis, and multiple cancers such as glioblastoma, lung malignancies, and leukemias. Several compounds such as polyphenols, doxazosin, baricitinib, and ruxolitinib could inhibit these interactions. It has been demonstrated that the SARS-CoV-2 spike protein has a stronger affinity for human ACE2 than the spike protein of SARS-CoV, leading the current study to hypothesize that the newly produced variant Omicron receptor-binding domain (RBD) binds to human ACE2 more strongly than the primary strain. SARS and Middle East respiratory syndrome (MERS) viruses against structural and NSPs have become resistant to previous vaccines. Therefore, the review of recent studies and the performance of current vaccines and their effects on COVID-19 and related diseases has become a vital need to deal with the current conditions. This review examines the potential role of these SARS-CoV-2 proteins in the initiation of chronic diseases, and it is anticipated that these proteins could serve as components of an effective vaccine or treatment for COVID-19 and related diseases.
... The envelope (E), membrane (M), and spike (S) structural proteins are anchored in the viral envelope, which is made up of a lipid bilayer. Approximately 74 surface spikes are present on a coronavirus (Bhat et al., 2021;Lalchhandama, 2020). Coronaviruses are zoonotic (Paramanya et al., 2021). ...
Diabetes has become a major metabolic disorder in the last few decades. It is manifested as dysregulation of glucose metabolism at one of the steps involving transport, absorption, and metabolic regulation by insulin. Changes in lifestyle and food consumption habits have also increased the number of people with diabetes. Some physicians prescribe synthetic drugs, controlled dietary plans, and regular exercises as part of diabetes management. Increased glucose level brings about several biochemical changes in the body. Structural alteration and functional loss of biomolecules are the consequences of changes brought about by glucose. Glycation is one of the major modifications of the long-lived proteins and other nitrogen-containing compounds. It leads to the generation of advanced glycation end products and free radicals under hyperglycaemic conditions. Scientists have continuously searched for a drug that could control the adverse effects of high glucose concentration, glycation, and oxidative stress. The focus is on looking for natural products or formulations as they are less harmful and more cost-effective than synthetic drugs. Among medicinal plants, Ficus carica has been widely used since ancient times and possesses many health-promoting activities like antidiabetic, antioxidant, antiobesity, anti-inflammatory, etc. These beneficial traits are due to various secondary metabolites, including phenolic acids, amino acids, hydrocarbons, fatty acids, volatile components, and other bioactive compounds. Latex contains a major amount of these compounds with some presence in leaves, fruit, and root. In this book chapter, the importance of Ficus carica phytochemicals in preventing diabetes, glycation, oxidative stress, and secondary complication of diabetes will be reviewed.
... In the previous two decades, closely related members of the betacoronavirus subfamily-SARS and MERS-have also caused outbreaks of worrying diseases [1,6,29,30,178]. SARS-CoV and MERS-CoV are also highly unlikely to be the first coronaviruses to cause severe illness in humans, as coronaviruses are known to cause severe disease in various animals and have accompanied humanity for most of its recent existence [36,129,[179][180][181][182][183]. Despite serological evidence lacking, based on the clinical picture and symptoms reported by the patients, some of which are highly similar to those induced by SARS-CoV-2 (mainly loss of taste and smell, clouding of consciousness, and encephalitis symptoms, all rarely seen in influenza), it is highly likely that the last great pandemic of the nineteenth century (1889-1891), the so-called Russian or Asian influenza, was also caused by a member of the coronavirus family [184,185]. ...
Definition: SARS-CoV-2, a member of the betacoronavirus group and causative agent of COVID-19, is a virus affecting multiple systems, not only the respiratory. One of the systems affected by the virus is the central nervous system, with neuropathological studies reporting a wide set of morphological phenomena-neuroinflammation, vascular and blood-brain barrier alterations, neurodegeneration, and accelerated aging, while contradicting data is present on the direct neuroinvasive potential of the virus and active viral replication within neurons. The depicted changes, other than an acute effect (which may contribute to the death of the patient), also have chronic sequelae in the context of post-COVID syndrome cognitive impediments, sleep, and mood disorders. The following chapter describes the basic neuropathological aspects of SARS-CoV-2 as based on the present evidence in scientific literature and proposes the term COVEP-COVID-associated encephalopathy to unite the undisputed effects of the infection on nervous system morphology and function.
... The severity of the symptoms of Covid 19 can range from very mild to severe, as some people develop only a few symptoms and others may not have any symptoms at all, yet they can spread the disease (transmitting the disease without showing symptoms on them), and symptoms such as dyspnoea and pneumonia may worsen [5]. In some people about a week after the onset of symptoms [6]. A COVID-19 diagnostic test is performed to find out if a person has the virus by: ...
... Structure of corona virus [6]. ...
Corona viruses are a family of viruses that can cause diseases such as the common cold and acute respiratory infection and in 2019, a new type of corona virus was discovered that caused an outbreak of a disease that originated in China. The virus is known as severe acute respiratory syndrome corona virus (SARS-CoV-2). The resulting disease is called emerging corona virus disease 2019 (COVID-19). In March 2020, the World Health Organization declared the corona virus (COVID-19) to be a global pandemic. In this research, a diagnostic kit was prepared that is used in the laboratory to detect infection with Acquired Corona Virus (COVID19) by the method of the enzyme immunoassay (ELISA). Conjugated secondary antibodies tagged with HRP which gives a color signal with the substrate added to it, its intensity depends on the amount of antibodies present in the pathological sample. We used a microtiter plate coated with the virus core and ns antigen and a conjugate product from Imbian Company, while the other of the kit components (reagents and buffers) were prepared in Al-Razi laboratories to be suitable for use. Tests were conducted on the prepared kit for 96 samples, including 55 samples for positive cases and 41 samples for negative cases, which were obtained from the specialized laboratories and patients. The tests showed conformity in the results compared to foreign kit used for this purpose and using the ELISA washer and reader devices available in Al-Razi center's laboratories. And by installing the method of preparation by fixing the method of preparation and obtaining identical results, Al-Razi center can produce pioneering batches and provide the laboratories of Ministry of Health of this type of diagnostic kits.
... Coronaviruses are representatives of a large group of RNA viruses [1]. According to their structure, these viruses have relatively large sizes, varying between 80 and 120 µm, but some members are characterized by smaller and significantly larger sizes-from 50 to 400 µm, with a molecular mass of about 40,000 kilodaltons [1][2][3][4]. The viral single-stranded RNA is enveloped by a double lipid membrane in which transmembrane and structural proteins are integrated, including the so-called spike proteins [5]. ...
Coronaviruses are a large group of RNA viruses, the most notable representatives of which are SARS-CoV, MERS-CoV and SARS-CoV-2. Human coronavirus infections were first documented in the 1960s, when members causing seasonal common colds were successfully replicated in human embryonal trachea and kidney cell cultures and classified based on electron microscopy. The history of coronaviruses stretched far back to that point, however, with some representatives causing disease in animals identified several decades prior and evolutionary data pointing towards the origin of this viral group more than 55 million years ago. In the short time period of research since they were discovered, coronaviruses have shown significant diversity, genetic peculiarities and varying tropism, resulting in the three identified causative agents of severe disease in humans—SARS, MERS and the most recent one, COVID-19, which has surpassed the previous two due to causing a pandemic resulting in significant healthcare, social and political consequences. Coronaviruses are likely to have caused pandemics long before, such as the so-called Asian or Russian influenza. Despite being epitheliotropic viruses and predominantly affecting the respiratory system, these entities affect multiple systems and organs, including the kidneys. In the kidneys, they actively replicate in glomerular podocytes and epithelial cells of the tubules, resulting in acute kidney injury, seen in a significant percentage of severe and fatal cases. Furthermore, the endothelial affinity of the viruses, resulting in endotheliitis, increases the likelihood of thrombotic microangiopathy, damaging the kidneys in a two-hit mechanism. As such, recently, COVAN has been a suggested nomenclature change indicating renal involvement in coronavirus infections and its long-lasting consequences.
... The coronavirus is further encircled by an outer membrane envelope comprised of lipids with specific proteins [membrane (M), envelope (E), and spike (S)] inserted to shape the viral envelope, maintain its size, and engage the host's cells [7]. The primary structural protein of the outer membrane that gives the membrane its overall form is the M protein, a type III membrane protein [8]. The E proteins, which are encased in the lipid layer, are in charge of morphogenesis, intracellular trafficking, and virion assembly [8]. ...
... The primary structural protein of the outer membrane that gives the membrane its overall form is the M protein, a type III membrane protein [8]. The E proteins, which are encased in the lipid layer, are in charge of morphogenesis, intracellular trafficking, and virion assembly [8]. The coronavirus's S protein, also known as the spike protein, is what gives it its distinctive halo-like look. ...
The coronavirus disease 2019 (COVID-19) pandemic determined the use of different research methods and investigations in the management of this novel infectious disease. The impact and development of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) at cellular level is still a challenge and many directions of investigation have been opened, a complex topic that has been explored is the bidirectional interaction between host micro-ribonucleic acids (miRNAs) and viral miRNA. The main point of this study is to analyze the transcriptional modifications induced by the viral infection at ocular level, mediated by miRNAs. It is known that the ocular transmission is a route of infection, and it can cause multiple neuro-ophthalmological manifestations, such as optic nerve dysfunction, eye movement abnormalities, oscillopsia and intracranial hypertension. We have managed to identify more than six miRNAs specifically involved in eye disorders that are strongly dysregulated by the SARS-CoV-2. These miRNAs regulate different pathways, such as the nuclear factor-kappa B (NF-κB) pathway, the expression of complement factor H (CFH) gene, the expression of transforming growth factor-beta (TGF-β), fibroblast growth factor (FGF) and platelet-derived growth factor (PDGF) genes. In the context of SARS-CoV-2 infection, many more molecular changes at ocular level need to be elucidated to better understanding the COVID-19.
... After binding to the ACE2, the spike is cleaved by aciddependent proteolysis of Human Airway Trypsin-like protease (HAT) and cathepsin and transmembrane protease Ser 2 (TMPRSS2), into two subunits of S1 and S2 20 . The S1 fragment consists the RBD section and the S2 fragment contains the C-terminal with the HR1 and HR2 (Heptad Repeat) sequences 21,22 . The RBD is the target of many primary neutralizing antibodies, for preventing the virus from binding to the receptor (ACE2/DPP4). ...
Background:
The highly contagious SARS-COV-2 virus spread rapidly from China and formed a global pandemic. The virus has infected over 509 million people worldwide and killed about 6.32 million up to date. Up on invasion, the Receptor Binding Domain (RBD) of Spike protein plays a crucial role in the entry of the virus into the host cell. The virus N protein is another protein that has a critical role for genome packaging.
Methods:
As bioinformatics approaches, the cassette design, codon adaptation, and protein stability were investigated in this study. Synthetic genes of RBD and N were cloned separately in pET28a + expression vector. They were transferred into Escherichia coli (E. coli) BL21 DE3 host cell, and expression of recombinant proteins was induced with IPTG. The recombinant proteins were purified by column chromatography and approved by Western blotting. Animal immunization was performed with each of the recombinant proteins individually and in combination of the two. The antibody titer of the blood serum from control and immunized mice groups was determined by ELISA technique. Finally, the anti-spike neutralization test was performed.
Results:
The expression and purification of RBD protein were monitored on SDS-PAGE, two bands of about 28 and 45 kDa for RBD and N appeared on gel distinctly, which were further validated by Western blotting. According to ELISA results, related antibodies were traced to a dilution of 1/64000 in immunized sera. The neutralization test exhibited produced antibodies' potency to bind the virus proteins. Using SPSS software, statistical analysis was performed by Duncan's test and T-test.
Conclusion:
According to the present study, recombinant proteins, either RBD alone or in combination with N adequately stimulated the immune response, and the raised antibodies could neutralize the virus in in vitro test.
... So far, a wide range of clinical symptoms have been seen in people infected SARS-CoV-2 for attachment. [5] The distribution of these communicating receptors in the different body organs determines the resulting disease's clinical presentation. ACE2R, for instance, has considerable expression in alveolar cells, and it is well known that COVID-19 causes serious lower respiratory tract presentations. ...
Background:
COVID-19 is responsible for the latest pandemic. Dipeptidyl peptidase-4 (DPP-4) is one of the cellular receptors of interest for coronavirus. The aim of this study was to assess the roles of DPP-4 inhibitors in prognosis of COVID-19 infection in patients with type 2 diabetes mellitus.
Materials and methods:
retrospective cohort study was performed in 2020 in military medical centers affiliated to AJA University of Medical Sciences in Tehran on 220 patients with type 2 diabetes mellitus who were admitted in medical centers with COVID-19 infection. We collected demographic data of patients including age, gender, drug history, usage of DPP-4 inhibitors, clinical presentations at the time of the first visit, and the disease outcome including hospitalization duration and need for respiratory assist.
Results:
The study population consisted of 133 males (60.5%) and 87 females (39.5%), with a mean age of 66.13 ± 12.3 years. Forty-four patients (20%) consumed DPP-4 inhibitors (sitagliptin and linagliptin). Patients who were treated with DPP-4 inhibitors required less oxygen (O2) therapies compared to other cases (76.7% vs. 88.6%, P = 0.04). Patients who were treated with DPP-4 inhibitors had significantly lower hospitalization duration compared to other cases (6.57 ± 2.3 days vs. 8.03 ± 4.4 days, respectively, P = 0.01). There were no significant differences between the two groups of patients regarding survival rates (P = 0.55). Age was a predictive factor for survival (odds ratio, 1.13; 95% confidence interval, 1.04-1.23; P = 0.004).
Conclusion:
DPP-4 inhibitors could significantly decrease hospitalization days in patients with type 2 diabetes mellitus who were hospitalized for COVID-19. However, DPP-4 inhibitor usage showed no statistically significant impact on survival. Age was the important prognostic factor.
... On average, the total molecular weight is 40,000 kDa. They're encased in a package containing a number of protein molecules (Lalchhandama, 2020). When the virus is outside the host cell, it is protected by the lipid bilayer envelope, membrane proteins, and nucleocapsid (Neuman et al., 2011). ...
... The S2 subunit creates the stem that secures the spike in the viral envelope and allows fusion during protease activation. As they are exposed on the viral surface, the two subunits remain non-covalently connected until they bind to the host cell membrane (Lalchhandama, 2020). Three S1 subunits are linked to two S2 subunits in a functionally active state. ...
Coronavirus is one of the most dangerous and contagious illnesses that arise from the introduction of host organisms into the biological system. As of March 2022, this sickness had caused more harm than good, with 479 million cases and 6.12 million deaths worldwide. These illnesses are unpredictable sources of social, financial, and economic distress. The rising incidence of infections is the most concerning aspect. Human coronaviruses were discovered in the 1960s using two distinct ways in the United Kingdom and the United States, while the first reports of coronavirus infection in animals occurred in the late 1920s when an acute respiratory infection of farmed hens developed in North America. Although some estimates place the common ancestor as far back as 55 million years or more, reflecting long-term co-evolution with bat and bird species, the most recent common ancestor (MRCA) of all coronaviruses is thought to have lived as recently as 8000 BCE. Coronaviruses have a single-stranded, positive-sense RNA genome that ranges in size from 26.4 to 31.7 kilobases. When the viral spike protein binds to its matching host cell receptor, infection occurs. There is no specific, effective, or 100 percent cure for coronavirus as of 2021, but supportive care, which includes treatment to relieve symptoms, fluid therapy, oxygen support, and prone positioning as needed, as well as medications or devices to support other affected vital organs, is the cornerstone of COVID-19 management.
... More than one organ may be impacted in very ill patients. Endothelial cells, the heart, the mind, the kidneys, the colon, the liver, the pharynx, and a variety of other tissues all have ACE2 receptors [1] . This virus has the ability to harm these organs right away. ...
... The overall molecular weight of corona virus is 40,000 kDa. Corona viruses are enclosed in an envelope lodge with some of the molecules of protein [1] . The virus of its membrane and nucleobases while it crust the host cell [2] . ...
... The overall molecular weight of corona virus is 40,000 kDa. Corona viruses are enclosed in an envelope lodge with some of the molecules of protein [1] . The envelope of virus is roughed of lipid bilayer where in the sheath and spike structural are berth [3] . ...
