Tag Archives: Receptor

The cat catches the coronavirus from owners | Instant News


Cases of Pets Contracting severe acute respiratory syndrome coronavirus 2 (SARS-cov-2) were registered since the beginning of the spread of coronavirus (COVID-19). Now the cat was the first animal in Britain to test positive after Contracting the virus from their owners.

The cat developed symptoms of shortness of breath. Dog owners took it to a veterinary clinic where it was initially suspected feline herpes virus, common respiratory infection in cats.

A sample from the cat tested positive for SARS-cov-2 in the framework of the research program at the University of Glasgow centre for virus research. This program aims to screen hundreds of samples for the presence of SARS-coronavirus-2 in the cat population of the country. The test was conducted in the Agency and health of plant and animal life in Weybridge, Surrey, on July 22.

The receptor ACE2 and human, illustration photo: Catherine Koh / Shutterstock In

Reverse zoonosis

Experts in health say that it is the first known human to cat transmission of SARS-cov-2 in the country, but that does not mean that the infection has not spread to people for their Pets.

Zoonoses is described as viral infections that jump from animals to humans, as coronavirusesthat generally occur in wild animals such as bats, camels and civets cats, among others. Severe acute respiratory syndrome (SARS) and middle East respiratory syndrome (MERS-Cov), which come from civet cats and camels. The current pandemic coronavirus was claimed to come from dinosaurs that have been infected by bats.

Pangolin. Image credit: 2630ben / Shutterstock In

Pangolin. Image credit: 2630ben / Shutterstock In

On the other hand, reverse zoonosis, when the virus first infects people, and then turns to animals. Since the emergence of the novel pandemic coronavirus, reports of infections in Dogs in Hong Kong and even at a tiger in a zoo in the United States.

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Siberian “Amur” tiger in the Bronx zoo. Image Credit: Vladimir Korostyshevskiy / Shutterstock In

Spread from humans to animals

The American centers for control and prevention (CDC) says that is still unknown, whence came the present disease coronavirus, but said it may come from an animal, like a bat.

“At this time, there is no evidence that animals play a significant role in the spread of the virus, which causes COVID-19. Based on the limited information currently available, the risk of spreading animal COVID-19 people is considered low,” the CDC said.

The health Agency added that more research is needed to shed light on how different animals can be affected COVID-19. As scientists try to learn more about the virus, it seems that it can be transmitted from people to animals in some situations.

“We are still learning about this virus, but it seems that it can be transmitted from people to animals in some situations, especially after close contact with a person sick with COVID-19,” the CDC explained.

The CDC also explained that cats, dogs and other animals can be infected with the novel coronavirus. However, he says that the experts don’t know all the animals that can be infected.

Animals and COVID-19

Three previous studies have discussed the risk of animal infection with SARS-coronavirus-2. In the study, researchers in the United Kingdom by the coronavirus can infect a broad range of animal speciesincluding dogs, cats, hamsters, rabbits, horses, goats, pigs, Buffalo, sheep, cattle, and lizards. These animals showed higher levels of viral entry.

The formation of syncytia following SARS-cov-2 spike expression. Effector cells expressing half of a dual luciferase-GFP reporter protein and SARS-cov-spike 2 were mixed with target cells expressing ACE2 proteins of the indicated nodes and the corresponding half of the reporter (see methods). Also the vector only control is enabled (pDISPLAY). Representative photomicrographs protein of GFP-positive syncytia formed as shown joint cultivation are. Images were captured using Incucyte live cell imager (Sartorius).

The formation of syncytia following SARS-cov-2 spike expression. Effector cells expressing half of a dual luciferase-GFP reporter protein and SARS-cov-spike 2 were mixed with target cells expressing ACE2 proteins of the indicated nodes and the corresponding half of the reporter (see methods). Also the vector only control is enabled (pDISPLAY). Representative photomicrographs protein of GFP-positive syncytia formed as shown joint cultivation are. Images were captured using Incucyte live cell imager (Sartorius).

Meanwhile, animals such as Turkey, chicken, and all kinds of bats supported lower levels of viral entry than the human angiotensin converting enzyme 2 (ACE2).the

Another study downloaded in BioRxiv identified SARS-cov-2 target cells in different tissues, a cat, a hamster, and pangolin. The most remarkable discovery was the fact that SARS-coronavirus-2 target cells was a high proportion of SARS-cov-2 target cells in cats.

Finally, scientists from the Chinese Academy of agricultural Sciences, the Chinese center for control and disease prevention, says SARS-cov-2 was capable of to engage and ACE2 receptors in a wide range of animal speciessuch as the greater horseshoe bat, domestic cat, dog, pig, goat, and Malayan pangolin.

Susceptibility to SARS-cov-2 from HEK293T cells provided by the different 2 species ACE2 I. HEK293T cells were transfected the plasmids expressing 3 ACE2 and pointed. Cells were infected with 0.5 MVD SARS-cov-2 24 h after transfection, 4, and was discovered for the replication of SARS-cov-2 ELISA.

Susceptibility to SARS-cov-2 from HEK293T cells provided by the different 2 species ACE2 I. HEK293T cells were transfected the plasmids expressing 3 ACE2 and pointed. Cells were infected with 0.5 MVD SARS-cov-2 24 h after transfection, 4, and was discovered for the replication of SARS-cov-2 ELISA.

Understanding zoonosis and reverse zoonosis of the pandemic coronavirus could help scientists study the behavior of the virus, and the likelihood of transmission from animals which can make containing the virus more difficult.

The impact of the pandemic coronavirus has already exceeded 16.48 million, resulting in the deaths of more than 654,000.

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Seaweed extract outperforms remdesivir in inhibiting SARS-cov-2 in studies of cells | Instant News


In the test of antiviral efficacy against the virus that causes COVID-19, an extract from edible seaweed, has exceeded remdesivir, the current standard antiviral used to combat the disease. Heparin, a common blood thinner, heparin and variant deprived of its anticoagulant properties, is performed at the same level with remdesivir in inhibiting SARS-cov-2 infection in mammalian cells.

Published online today in Opening Cellsthe study is the latest example of the lure of the strategy, researchers from the center for biotechnology and interdisciplinary studies (CBIS) at Rensselear Polytechnic Institute are developing against viruses such as the coronavirus that triggered the current global health crisis.

The spike protein on the surface of SARS-cov-2 clips on the ACE-2 receptor, a molecule on the surface of human cells. After installation, the virus inserts its genetic material into the cell by hijacking the cell machinery for the production of replica viruses. But the virus can just as easily be convince to lock the bait molecule that offers such devices. Neutralized the virus will be trapped and eventually degraded naturally.

Previous studies have shown that this technique works the decoy in the breeding of wild other viruses, including Dengue, zika and influenza A. to listen to the researchers discuss their findings by watching this video.

We learn to block viral infection, and this knowledge we’ll need if we want to confront the pandemic. The reality is that we have no good antivirals. To protect yourself against future pandemics, we need an Arsenal of approaches that we can quickly adapt to emerging viruses.”

Jonathan Dordick, the lead researcher and Professor of chemical and biological engineering rensselaer Polytechnic Institute

In Opening Cells paper tests of antiviral activity in three variants with heparin (heparin, trisulfated heparin, and without anticoagulant low molecular weight heparin) and two fucoidan (EPI-27 and RPI-28) derived from marine algae. All five compounds are long chains of sugar molecules, known as sulfated polysaccharides, structural conformation that the results of the binding study published earlier this month in anti-virus research is proposed as an effective bait.

Scientists have conducted studies of dose-response is known as the EC50 is the abbreviation for effective concentration of compound that inhibits 50% of viral infectivity — with each of the five compounds on mammalian cells. According to the results the EC50 is given in molar concentration, the lower the value of the signal more powerful composition.

IRTS-27 gave an EC50 value of approximately 83 molar, while similar to the previously published and independent in a test tube remdesivir on the same mammalian cells gave EC50 770 molar. Heparin gave EC50 of 2.1 microns, or about one-third as active as remdesivir, and the anticoagulant heparin gave similar EC50 5.0 µm, about one-fifth as active as remdesivir.

A separate test detected a toxic effect on the cells in any of the compounds, even at the highest concentration.

“What we want is a new way to get an infection,” said Robert Linhardt, Professor Rensselaer chemistry and chemical biology, which cooperates with the Dordick to develop a bait strategy. “Current thinking is that COVID-19 infection starts in the nose, and any of these substances could be the basis for a nasal spray. If you could just treat the infection, or early treatment even before you have the infection, you would have a way to block it before it enters the body”.

Added Dordick that compounds from algae “can serve as the basis for the oral approach, and delivery to address potential gastrointestinal infections.”

In the study of SARS-cov-2 sequencing data, Dordick and Linhardt identified several motifs on the structure of the spike protein, which is promised to Fit compatible with heparin, as a result, it was confirmed during the mandatory study. The spike protein is heavily encrusted in glycans, it is a fixture that protects it from human enzymes that can degrade it, and prepares it for binding with the specific receptor on the cell surface.

“This is a very complex mechanism that we, frankly, don’t know all the details, but we get more information,” said Dordick. “The only thing that was clear from this study is that the larger the molecule, the better suited you. More successful connections of large sulfated polysaccharides that offer a larger number of sites on the molecules to trap the virus.”

Molecular simulation-based binding study showed the sites on the spike protein where heparin can interact, increasing the prospects for such sulfated polysaccharides.

“This is a fascinating study of Professor Dordick and Linhardt among several ongoing studies in CBIS, as well as elsewhere in Rensselaer, for solving problems COVID-19 pandemic using new therapeutic approaches and repurpose existing drugs,” said CBIS Director Deepak Vashishth.

“Sulfated polysaccharides can effectively inhibit the SARS-cov-2 in vitro” was published in Opening Cells supported by the National research Foundation of Korea. In Rensselaer, Dordick and Linhardt were United in the study of Paul S. Kwon, Seok-Joon Kwon, Jin goes, fuming Zhang, and Kate Fraser and researchers at the Korea research Institute of Bioscience and biotechnology in Cheongju, Republic of Korea, and Zhejiang University of technology in Hangzhou, China.

Source:

Journal reference:

Kwon, S. P., et al. (2020) sulfated polysaccharides can effectively inhibit the SARS-cov-2 in vitro. The Opening Of The Cell. doi.org/10.1038/s41421-020-00192-8.

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SARS-cov-2 serological test for 50 cents a sample! | Instant News


Given the continued and alarming increase in both cases and deaths due COVID-19 around the world, scientists are still in search of effective tools for diagnosis of infection. One important way of testing for severe acute respiratory syndrome coronavirus 2 (SARS-cov-2) – serology, but this requires a supply of high-quality recombinant viral antigens.

A recent study published in the preprints server medRxiv* in July 2020 shows that it is indeed possible. The development of this inexpensive, but reliable and sensitive test could change the face of preventive measures for COVID-19 limited resources.

Spike Antigen

SARS-coronavirus-2 spike antigen is one of the most important viral antigens, with researchers focusing on it for the production of vaccines, antivirals and serological tests. Serology is important to track cases, contacts to display, epidemiological surveillance and identification of asymptomatic patients, and identify the mechanism of antiviral immunity.

In Spike protein consists of two subunits, S1 and S2, which mediate receptor binding and membrane fusion, respectively. This allows the virus to penetrate the cell. This protein is a target for neutralizing antibodies, and the most common serological tests for SARS-cov-2 is an enzyme immunosorbent analysis (ELISA) – based protein.

This test is popular for its simplicity and cross-reactivity against the spike proteins of other coronaviruses in the current edition. Moreover, its intensity corresponds to the level of neutralizing antibodies.

Study: characterizing the low-cost IFA

This study was based on the identification of the key features that will allow you to develop an inexpensive test enzyme immunoassay, based on the immunological reaction of antibodies with protein. The goal was to produce a test that will allow large-scale screening for infection in low-income.

Researchers have focused mainly on reducing the cost of manufacturing test by developing optimum means of production of the antigen and making the necessary changes in the method of collecting antigen and sample processing. As a result, they were able to develop a test that will cost less than 50 cents per sample.

To Produce Recombinant Antigen

The researchers cultured SARS-coronavirus-2 protein is in a stable condition prior to the merge in cell culture using a method that allows protein to be expressed stably and as a constitutive feature. It was through the integration of the transgene into the genome of cells in culture.

This adaptation leads to increased scalability, and low cost recombinant proteins. They also used methods of cotransfection gene’s, as well as open source plasmid, which has a selection handle to avoid having to wait for a synthetic gene that needs to be built and sent through the pandemic-disrupted supply chain. Thus, the result is a recombinant cell line expressing high levels of protein were produced within 24 days of transfection and still shows steady expression up to 100 days.

This achievement gives the opportunity to “develop a less expensive, long lasting batch refeed or perfusion technology for cell culture,” according to researchers. They also succeeded in finding an inexpensive nutrient media to support cell growth and high level production of protein. Thus, they have developed a workflow using low-cost methods to achieve the goal of increasing the density of cells in culture with high s secretion of the protein.

Affinity purification chromatography (AC) used resin was more expensive than originally planned ultrafiltration/diafiltration filter (UF/DF), but has become necessary because of failure of the latter to remove smaller contaminants protein. However, they found that it can be used for more than 30 cycles, which reduces the cost of its use.

Then they created an ELISA to detect anti-s antibodies in human serum, plasma, and eluted whole blood samples, called s-ufrj website IFA. They set the amount of highly purified protein (from AC) needed to ensure legible results between negative and positive samples, 150 NG.

Evaluation of sensitivity and specificity

Then the website ufrj Elisa was used to test 210 is negative and positive serum samples, 66 samples from 38 symptomatic COVID-19 patients, 124 samples from the pandemic, and 20 of COVID-19 negative people. They received 122 out of 124 negative samples, the specificity 98%. In addition, the samples 53/66 were positive for IgG, to reduce the sensitivity to 80%.

For comparison, obtained from a commercial IgG rapid diagnostic tests (RDTs), as approved by the Brazilian regulatory health organization, conducted by the Agency only 46% sensitivity.

Then they re-IgG-negative samples from S website ufrj ELISA IgM rapid test. They found that most samples that were negative for IgG and negative for IgM and IgG positive in the first test was IgM positive result of the proximate analysis as well. They, therefore, came to the conclusion that the two false-negative results from symptomatic patients, might have been samples collected early in the disease.

The increase in false positives with increasing duration of symptoms

When the website ufrj ELISA sample results were compared against the duration since symptom onset, they were more likely to be positive, as the duration increased, as a result of seroconversion some individuals who were PCR-positive, negative, scored on IFA for the first time, but positive for anti-s IgG antibodies for the second time. The level of seroconversion to Anti-s IgG antibodies with this test increased from 42% to 100% in direct proportion to the time of onset of symptoms, and from the tenth day, he was consistently above 90%.

An important finding was that the real test detects seroconversion earlier than the rapid test, which had a peak detection rate of 71%, even 20 days from the onset of symptoms.

They also tested the neutralizing ability COVID-19 patients with neutralization of plaque (MFN). Samples with high anti-s IgG antibodies titer was the highest titer of neutralization.

Simplify collection and storage of blood

The researchers also sought to overcome the traditional bottleneck of sample collection and processing in the clinical laboratory under refrigerated storage. They created a simple system for the collection of fingerprick blood in filter paper strips. The use of dried blood spot on filter paper showed comparable results of testing serum.

Dried blood samples (DBS) obtained by a prick of the finger with commercially available devices for piercing. 2.5 cm (W) x 7.5 cm (l) paper filter with three spots of blood from the same volunteers and a commercially available paper hole punching devices have been used DB (arrow), which eluted in the blood for ELISA testing.

The consequences

Thus, low cost of consumables, along with labor, transportation, and equipment costs, all must fit in a half dollar per test, which is approximately 200 times less than the tests currently used in the United States. Another advantage is that spots of blood in sealed plastic bags can be stored for 2 months at least, but still return accurate results serological.

Thus, this study concludes: “on the S website ufrj enzyme immunoassay, including the use of eluates from whole blood pricking her finger as samples, allows a wide serological survey of the population, irrespective of their geographical and socio-economic aspects”. It will be invaluable for the formation of public health strategies to prevent further waves of the pandemic.

*Important Notice

medRxiv publishes preliminary research reports that are not reviewed and therefore should not be considered as a convincing guide to clinical practice/behavior, health-related, or be considered as reliable information.

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Research finds that specific brain cells trigger sugar consumption and cravings | Instant News


New research has identified specific brain cells that control how much sugar you eat and how hungry you are for sweet foods.

Most people enjoy sweets from time to time. However, unchecked “sweets” can lead to excessive consumption of sugary foods and chronic health problems such as obesity and type 2 diabetes. Understanding the biological mechanisms that control sugar intake and preference for sweetness may have important implications for controlling and preventing these health problems.

The new research is led by Dr. Matthew Potthoff, associate professor of neuroscience and pharmacology at Carver University in Iowa, and Dr. Matthew Gillum at Copenhagen University in Denmark. The research focuses on the action of a hormone called fibroblast growth. Factor 21 (FGF21). This hormone is known to play a role in energy balance, weight control and insulin sensitivity.

This is the first study to truly identify where this hormone works in the brain, and provides very cool insights into how to regulate sugar intake. “

Matthew Potthoff, a member of the Eagle Diabetes Brotherhood Research Center at UI and the Iowa Neuroscience Institute

Potthoff and his colleagues previously discovered that FGF21 is made in the liver in response to elevated sugar levels and plays a role in the brain to suppress sugar intake and preference for sweetness.

Based on this discovery, the team now shows for the first time which brain cells respond to FGF21 signaling and how this interaction helps regulate sugar intake and sweetness preferences. The study was published in the journal Cell metabolism, Also revealed how hormones mediate their effects.

Although FGF21 is known to function in the brain, because hormone receptors are expressed at very low levels, it is difficult to “see”, so determining the exact cellular target becomes complicated. Using various techniques, the researchers were able to accurately identify which cells express the FGF21 receptor. By studying these cells, studies have shown that FGF21 targets glutamatergic neurons in the brain to reduce sugar intake and sweet taste preference. The researchers also showed that the effect of FGF21 on specific neurons in the hypothalamus of the peritoneum reduces sugar intake by enhancing the sensitivity of neurons to glucose.

Several drugs based on modified forms of FGF21 have been tested as treatments for obesity and diabetes. The new discovery may cause the new drug to more precisely target the different behaviors controlled by FGF21, which may help control how much sugar a person eats.

Resources:

Journal reference:

Jensen-Cody, so, Wait. (2020) FGF21 signaling to the hypothalamus glutamatergic neurons in the hypothalamus inhibits carbohydrate intake. Cell metabolism. doi.org/10.1016/j.cmet.2020.06.008.

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