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Animal Connection Challenges
Published in Michael Hehenberger, Zhi Xia, Huanming Yang, Our Animal Connection, 2020
Michael Hehenberger, Zhi Xia, Huanming Yang
Angiotensin-converting enzyme 2 (ACE2) is attached to the outer surface (cell membranes) of cells in the lungs, arteries, heart, kidney, and intestines. By catalyzing the hydrolysis of angiotensin II (a vasoconstrictor peptide) into the vasodilator agent angiotensin (1–7), ACE2 lowers blood pressure. ACE2 thereby counters the activity of the related angiotensin-converting enzyme (ACE) by reducing the amount of angiotensin-II and increasing Ang(1–7).d It is well known that several human blood pressure reducing drugs are “ACE inhibitors.”383
Enrich to Rich—an Indigenous Model to Combat COVID-19
Published in Suman Lata Tripathi, Kanav Dhir, Deepika Ghai, Shashikant Patil, Health Informatics and Technological Solutions for Coronavirus (COVID-19), 2021
According to the genetic analysis of SARS-CoV-2, very close similarities between these viruses have been found in the virus. It is called corona virus. The mediating animal between bats and humans is the scaly cat. The scaly cat is known for its strange-looking scales and its habit of wrapping itself when its life is in danger, but they are smuggled into China for the scales and their meat. It mediates viral transmission from animals to humans. A virus has to reach human cells. It tries to establish a relationship with the proteins on the viral cell. Each cell contains some trace proteins. These proteins are called receptor proteins, e.g., the HIV virus only associates with CD4 lymphocytes. Once in contact with the scar protein, the virus enters the cell. The virus divides into cells. Thus the host cells become infected. If this does not happen, the virus cannot enter the cell. The corona virus has found a very simple way to get into the cells of the shelter. The glycoprotein spikes on the surface of the virus (spikes with spikes on the soles of the feet for walking on ice) are constantly peeking out of the surface. These are called glycoproteins. This is because this protein is accompanied by a sugar molecule. The glycoprotein that comes out makes the virus look like a crown of thorns. This is why the virus is called corona virus. Spike protein is attached to the actual shelter cell. This is called “S1 unit.” The structure of the “S1 unit” is so varied that the “S1 unit” is attached to many mammalian cells. Scientists have discovered exactly which endothelial cell protein is associated with the S1 unit of the SARS CoV2 virus. This pair is like the key to a seven-sided lock. Sticking to the surface cells of the human respiratory tract is a very minor matter in terms of corona virus. The SARS CO-V2 virus infects the protein in the receptor cell called ACE2 and causes further disease. Another worrying virus is influenza. All influenza viruses originate from waterfowl such as ducks, geese, terns, gulls and the like. Reaching humans from birds is the closest way to them. Because birds and humans are warm-blooded, their body temperatures are similar. In many cases, the parasite’s survival in the new shelter is a dead end. Bird flu has spread from bird to human but has not usually spread from one human to another, with the exception of the 2009 swine flu outbreak of H1N1. The virus spread so rapidly in humans that the outbreak of swine flu had to be declared ubiquitous. In 1918, the bird flu outbreak was global [2].
COVID-19: a pandemic challenging healthcare systems
Published in IISE Transactions on Healthcare Systems Engineering, 2021
Lidong Wang, Cheryl Ann Alexander
SARS-CoV-2 is a single-stranded RNA-enveloped virus. It targets cells via the S protein which binds to the angiotensin-converting enzyme 2 (ACE2) receptor. After binding to the ACE2 receptor, viral DNA actively transports into the cell using endosomes. Viral entry via the S protein through the host type-2 receptor is assisted with transport by the transmembrane serine protease TMPRSS2, found in the host ACE2 receptor. After viral particles are transported into the cell, viral polyproteins are synthesized and encode for the replicase-transcriptase complex which subsequently integrate the viral RNA and structural proteins, later assembling the viral particles for completion for release to infect the next host cell (Sanders et al., 2020). Researchers have confirmed ACE2 as the receptor which plays the necessary role in human-to-human transmission and infection of SARS-CoV-2. Data about single-cell RNA sequencing (scRNA-seq), which is available online, was collected to assess the cell specific expression of ACE2 in multiple fetal organs and the maternal-fetal interface. It was shown that ACE2 was greatly expressed in the cells of the interface. Also, ACE2 was expressed in specific cell categories of human fetal heart, lung, liver, except kidney (Li et al., 2020).
COVID-19 and the workplace: Research questions for the aerosol science community
Published in Aerosol Science and Technology, 2020
William G. Lindsley, Françoise M. Blachère, Nancy C. Burton, Brian Christensen, Cheryl F. Estill, Edward M. Fisher, Stephen B. Martin, Kenneth R. Mead, John D. Noti, Melissa Seaton
Animal models that are permissive to infection and mimic the pathogenesis of SARS-CoV-2 in humans are ideal for assessing the modes of transmission (Callaway 2020; Sutton and Subbarao 2015; Yuan et al. 2020). Key to transmission is the ability of the S protein of SARS-CoV-2 to bind the ACE2 receptor on host cells (Hoffmann et al. 2020; Wrapp et al. 2020). Wan et al. (2020) stated that mice will not be a good model unless they were genetically engineered to express the human ACE2 receptor but that pigs, ferrets, cats, and nonhuman primates may be good animal models because their ACE2 protein sequences are identical or very similar to human ACE2. Recent studies have shown that SARS-CoV-2 can replicate in macaques (Deng et al. 2020; Rockx et al. 2020; Yu et al. 2020b), golden Syrian hamsters (Chan et al. 2020), and ferrets (Shi et al. 2020). Kim et al. (2020) showed that ferrets could indirectly transmit SARS-CoV-2 to naïve ferrets housed in separate cages, which the authors suggest indicates airborne transmission.
Testing and surveillance strategies in the context of COVID-19 in India
Published in Indian Chemical Engineer, 2020
Somdatta Karak, Surabhi Srivastava, Rakesh K Mishra
The SARS-CoV-2 genome encodes 29 proteins and the virus needs the cellular machinery hijacked from the host for their synthesis and further replication. The spike proteins on the surface of SARS-CoV-2 bind with Angiotensin Converting Enzyme-2 (ACE-2) receptors on the host cells [10]. This binding facilitates the entry of the virus into the host cells. In humans, ACE-2 receptors are expressed in a wide variety of tissues including the heart, vessels, gut, lung (particularly in type 2 pneumocytes and macrophages), kidney, testis and brain [11]. The expression pattern corroborates the systemic damage seen in these organs in some COVID-19 patients.