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Comment by Dr. Krishna Kumari Challa on October 14, 2020 at 5:37am

Covid-19 reinfection casts doubt on virus immunity: study

COVID-19 patients may experience more severe symptoms the second time they are infected, according to research released this week confirming it is possible to catch the potentially deadly disease more than once.

The study charts the first confirmed case of COVID-19 reinfection in the United States. 

The patient, a 25-year-old man, was infected with two distinct variants of SARS-CoV-2, the virus that causes COVID-19, within a 48-day time frame.

The second infection was more severe than the first, resulting in the patient being hospitalised with oxygen support.

The study also reminded us the four other cases of reinfection confirmed globally, with one patient each in Belgium, the Netherlands, Hong Kong and Ecuador. Experts say the prospect of reinfection could have a profound impact on how the world battles through the pandemic. In particular, it could influence the hunt for a vaccine.

Vaccines work by triggering the body's natural immune response to a certain pathogen, arming it with antibodies it to fight off future waves of infection.

But it is not at all clear how long COVID-19 antibodies last.

For some diseases, such as measles, infection confers lifelong immunity. For other pathogens, immunity may be fleeting at best.

The authors said the US patient could have been exposed to a very high dose of the virus the second time around, triggering a more acute reaction.

Alternatively, it may have been a more virulent strain of the virus.

Another hypothesis is a mechanism known as antibody dependent enhancement—that is, when antibodies actually make subsequent infections worse, such as with dengue fever.

The researchers pointed out that reinfection of any kind remains rare, with only a handful of confirmed cases out of tens of millions of COVID-19 infections globally.

However, since many cases are asymptomatic and therefore unlikely to have tested positive initially, it may be impossible to know if a given COVID-19 case is the first or second infection.

https://www.thelancet.com/journals/laninf/article/PIIS1473-3099(20)30764-7/fulltext

https://medicalxpress.com/news/2020-10-covid-reinfection-virus-immu...

Comment by Dr. Krishna Kumari Challa on October 14, 2020 at 5:25am

Binge drinking may cause Alzheimer's disease—and it might strike younger and in a severe form

Binge drinking may be linked to both the onset and severity of Alzheimer's disease, but scientists have only now embarked on a path to decipher each molecular step involved in how excessive alcohol consumption leads to the most common form of dementia.

Excessive alcohol consumption is toxic to the brain. Binge drinking likely plays an insidious role in the alteration of a normal brain protein  into a biological rogue that is highly prevalent in Alzheimer's disease. The protein is identified by a simplistic monosyllabic name—tau.

In its normal conformation, tau is found in neurons modulating the stability of axonal microtubules. But in its abnormal conformation, tau has long been considered one of the leading hallmarks of Alzheimer's, and makes up the tangles in the notorious "plaques and tangles" pathology. The plaques are deposits of the protein beta amyloid. 

 The main aim of this study is how tau transforms from a normal protein into a neuron-annihilating cause of Alzheimer's under the influence of excessive alcohol. 

The scientists are delving into how tau can become phosphorylated, which means its structural conformation changes and its role in the brain becomes chemically altered under the influence of binge drinking. Studies have shown that frequent and heavy alcohol drinking is linked to earlier onset and increased severity of Alzheimer's disease.

It has been reported that alcohol consumption correlates with Alzheimer's-like cortical atrophy in individuals at high risk of developing the disease as well as younger age of onset.

In addition, chronic alcohol exposure caused neural tau phosphorylation in the hippocampus and memory-impairment in Alzheimer's-predisposed mice.

Archna Sharma et al. Potential Role of Extracellular CIRP in Alcohol-Induced Alzheimer's Disease, Molecular Neurobiology (2020). DOI: 10.1007/s12035-020-02075-1

https://medicalxpress.com/news/2020-10-binge-alzheimer-diseaseand-y...

Comment by Dr. Krishna Kumari Challa on October 13, 2020 at 7:47am

Where You Sit in a Room Can Influence Your Risk of Catching COVID-19

https://www.sciencealert.com/where-you-sit-in-a-classroom-might-inf...

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Non-Concussive Head Hits Influence the Brain’s Microstructure

Comparing the brain scans of high-impact rugby players with those of athletes in noncontact sports, such as rowing and swimming, revealed tiny, yet significant, differences in the brain’s white matter.

https://www.the-scientist.com/the-literature/non-concussive-head-hi...

Comment by Dr. Krishna Kumari Challa on October 13, 2020 at 6:42am

New Type of Immunotherapy Helps Mice with Hard-to-Treat Breast Cancer Survive Longer

Comment by Dr. Krishna Kumari Challa on October 13, 2020 at 6:40am

**Oral cancer pain predicts likelihood of cancer spreading

 Oral cancer is more likely to spread in patients experiencing high levels of pain, according to a team of researchers at New York University College of Dentistry that found genetic and cellular clues as to why metastatic oral cancers are so painful.

The findings—which appear in Scientific Reports, a journal published by Nature—may ultimately be used to alleviate oral cancer pain and refine surgical decision making when treating oral cancer.

Oral cancer can cause severe pain during everyday activities, including talking and eating. Previous research by Brian L. Schmidt, DDS, MD, PhD, director of the NYU Oral Cancer Center and one of the study’s authors, suggests that patients with metastatic oral cancer—cancer that spreads beyond the mouth—experience more pain than those whose cancer has not spread. The new study helps researchers understand why.

https://researchnews.cc/news/3000/Oral-cancer-pain-predicts-likelih...

Comment by Dr. Krishna Kumari Challa on October 13, 2020 at 6:24am

Carnivores living near people feast on human food, threatening ecosystems

Ecologists  have found that carnivores living near people can get more than half of their diets from human food sources, a major lifestyle disruption that could put North America's carnivore-dominated ecosystems at risk. The researchers studied the diets of seven predator species across the Great Lakes region of the U.S. They gathered bone and fur samples for chemical analysis from areas as remote as national parks to major metropolitan regions like Albany, New York. They found that the closer carnivores lived to cities and farms, the more human food they ate.

 Philip J. Manlick el al., "Human disturbance increases trophic niche overlap in terrestrial carnivore communities," PNAS (2020). www.pnas.org/cgi/doi/10.1073/pnas.2012774117

https://phys.org/news/2020-10-carnivores-people-feast-human-food.ht...

Comment by Dr. Krishna Kumari Challa on October 13, 2020 at 6:20am

Scientists engineer bacteria-killing molecules from wasp venom

A team led by scientists  has engineered powerful new antimicrobial molecules from toxic proteins found in wasp venom. The team hopes to develop the molecules into new bacteria-killing drugs, an important advancement considering increasing numbers of antibiotic-resistant bacteria which can cause illness such as sepsis and tuberculosis.

The  researchers altered a highly toxic small protein from a common Asian wasp species, Vespula lewisii, the Korean yellow-jacket wasp. The alterations enhanced the molecule's ability to kill bacterial cells while greatly reducing its ability to harm human cells. In animal models, the scientists showed that this family of new antimicrobial molecules made with these alterations could protect mice from otherwise lethal bacterial infections.

 Osmar N. Silva el al., "Repurposing a peptide toxin from wasp venom into antiinfectives with dual antimicrobial and immunomodulatory properties," PNAS (2020). www.pnas.org/cgi/doi/10.1073/pnas.2012379117

https://phys.org/news/2020-10-scientists-bacteria-killing-molecules...

Comment by Dr. Krishna Kumari Challa on October 13, 2020 at 5:57am

Dueling proteins give shape to plants

In an elegant choreography, plants take cues from their environment and channel them into flowers, roots, or branches.

Researchers have been studying two key groups of proteins that influence plant form and timing of developmental transitions. Terminal Flower 1 (TLF1) proteins promote branch formation. When it is repressed, flowers grow. Flowering Locus T (FT) proteins, on the other hand, promote flowering in response to seasonal cues like day length. Strangely enough, the two proteins are almost identical.

These two elements have significance galore. Besides flowering, they're involved in tuberization in potatoes, bulb formation in onions, tendril formation in grapes, growth cessation in trees, lots of things.

Manipulating these genes, some have argued, could lead to the next "green revolution" as one could theoretically "trick" a plant that normally only flowers in the long days of summer to flower quickly, and thus produce fruit or seed, in the short days of winter with a deft genetic edit of TFL1. Or, in an area with a longer growing season, a clever manipulation of growth architecture via FT could encourage increased branching and then a later, and more abundant, flowering and fruit development on the many branches.

Nature Communications (2020). DOI: 10.1038/s41467-020-18782

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Plants have already been bred to have reduced TFL1 activity. Tomato gardeners may know these as determinant plants, which set all their flowers at the same time, as opposed to the indeterminant variety, which continue to branch, flower, and fruit over a period of months. Determinant plants make commercial agriculture more efficient, as fruits can be harvested in one go as opposed to repeated passes.

https://phys.org/news/2020-10-dueling-proteins.html?utm_source=nwle...

Comment by Dr. Krishna Kumari Challa on October 13, 2020 at 5:26am

Experimental COVID-19 treatment given to Trump found to relieve symptoms in macaques and hamsters

A team of researchers with Regeneron Pharmaceuticals, Inc., working with the Texas Biomedical Research Institute, has found that the antibody cocktail given to President Trump was effective in reducing COVID-19 symptoms in rhesus macaques and golden hamsters. 

The US president had received an experimental antibody cocktail along with doses of vitamin D, zinc and a heartburn medicine. The experimental antibody cocktail he was given was provided courtesy of Regeneron Pharmaceuticals, Inc., a company that has been conducting research into the use of such antibody cocktails as therapies for a host of viral infections, including COVID-19. In this new effort, the researchers tested the antibody cocktail with rhesus macaques and golden hamsters.

In the first part of the study, the researchers administered the cocktail (which they call REGN-COV2) to healthy rhesus macaques. Prior research had shown that they can infected by the SARS-CoV-2 virus, but typically exhibit only mild symptoms. Three days after receiving the cocktail, the monkeys were injected with the SARS-CoV-2 virus and then monitored to see if the treatment had any impact. They found that monkeys who had received the treatment prior to infection exhibited far fewer symptoms than a control group and had a much lower viral load.

The researchers also injected some of the monkeys with the cocktail after they were infected and found that doing so also reduced symptoms and resulted in faster viral clearance. The researchers next repeated the same experiments with golden hamsters. They, too, have been found to be susceptible to COVID-19, but have much more severe symptoms, including major weight loss. They found that giving it to them two days before they were infected with the SARS-CoV-2 virus resulted in greatly reduced symptoms and they did not suffer weight loss. And giving it to the hamsters after an infection had set in also resulted in reduced symptoms and faster viral clearance.

The researchers suggest that REGN-COV2 may offer therapeutic benefits both as a treatment and as a preventative measure for COVID-19.

Alina Baum et al. REGN-COV2 antibodies prevent and treat SARS-CoV-2 infection in rhesus macaques and hamsters, Science (2020). DOI: 10.1126/science.abe2402

https://medicalxpress.com/news/2020-10-experimental-covid-treatment...

Comment by Dr. Krishna Kumari Challa on October 13, 2020 at 5:18am

New virtual reality software allows scientists to 'walk' inside cells

Virtual reality software which allows researchers to 'walk' inside and analyse individual cells could be used to understand fundamental problems in biology and develop new treatments for disease. The software, called vLUME, was created by scientists. It allows super-resolution microscopy data to be visualised and analysed in virtual reality, and can be used to study everything from individual proteins to entire cells.

Super-resolution microscopy, which was awarded the Nobel Prize for Chemistry in 2014, makes it possible to obtain images at the nanoscale by using clever tricks of physics to get around the limits imposed by light diffraction. This has allowed researchers to observe molecular processes as they happen. However, a problem has been the lack of ways to visualise and analyse this data in three dimensions.

vLUME is revolutionary imaging software that brings humans into the nanoscale. It allows scientists to visualise, question and interact with 3-D biological data, in real time all within a virtual reality environment, to find answers to biological questions faster. It's a new tool for new discoveries. Viewing data in this way can stimulate new initiatives and ideas.

vLUME: 3D virtual reality for single-molecule localization microscopy, Nature Methods (2020). DOI: 10.1038/s41592-020-0962-1

https://techxplore.com/news/2020-10-virtual-reality-software-scient...

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