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Comment by Dr. Krishna Kumari Challa on October 10, 2020 at 7:00am

Bacteria-fighting cells in the airways boost infection risk from viruses

Having more bacteria-fighting immune cells in the nose and throat may explain why some people are more likely to be infected by respiratory viruses.

researchers found that volunteers who succumbed to infection from respiratory syncytial virus (RSV) had more specialized white blood cells called neutrophils in their airways before exposure to the virus, compared to those who staved off infection. According to the researchers, this type of neutrophil-driven inflammation in the nose and throat—typically associated with fighting off bacterial infections—may compromise our ability to fight off invading viruses and make us more susceptible to viral infections. The findings could help researchers to understand why people respond differently to the same viral threat, predict who is more at risk of infection, and even lead to preventative treatments to protect against RSV and potentially other respiratory viruses, including influenza and coronaviruses. when they analyzed samples from participants' airways taken before they were exposed to the virus, the team found evidence of neutrophil activation in the nasal mucosa—the cells lining the inside of the nose—in those who became infected with the virus. These immune cells are known to release proteins which help create an antibacterial environment in response to a threat. But the researchers believe this antibacterial immune response may come at a cost, making a host more susceptible to viruses by effectively switching off the early warning system, letting them slip through the net to cause infection.

 Neutrophilic inflammation in the respiratory mucosa predisposes to RSV infection. Science, science.sciencemag.org/cgi/doi … 1126/science.aba9301

https://medicalxpress.com/news/2020-10-bacteria-fighting-cells-airw...

Comment by Dr. Krishna Kumari Challa on October 10, 2020 at 6:26am

**Do cloth masks work? Only if you machine wash them after every single use

A new publication from researchers  advises daily washing of cloth masks to reduce the likelihood of contamination and transmission of viruses like SARS-CoV-2. Cloth masks must be washed daily at high temperatures to be protective against infection, a new analysis shows. It was found that if cloth masks were washed in the hospital laundry, they were as effective as a surgical mask.

It is important to note that given the study was conducted over five years ago, the researchers did not test for SARS-CoV-2—instead, they included common respiratory pathogens such as influenza, rhinoviruses and seasonal coronaviruses in their analysis. It is based on self-reported washing data and was conducted by health workers in high risk wards in a healthcare setting.

"While someone from the general public wearing a cloth mask is unlikely to come into contact with the same amount of pathogens as healthcare worker in a high risk ward, we would still recommended daily washing of cloth masks in the community. COVID-19 is a highly infectious virus, and there is still a lot that we don't know about it, and so it's important that we take every precaution we can to protect against it and ensure masks are effective.

According to the analysis, handwashing the masks did not provide adequate protection. Healthcare workers who self-washed their masks by hand had double the risk of infection compared to those who used the hospital laundry

The WHO recommends machine washing masks with hot water at 60 degrees Celsius and laundry detergent, and the results of our analysis support this recommendation.

Washing machines often have a default temperature of 40 degree or 60 degrees, so do check the setting. At these very hot temperatures, handwashing is not possible. The clear message from this research is that cloth masks do work—but once a cloth mask has been worn, it needs to be washed properly each time before being worn again, otherwise it stops being effective.

There is much research on the design, fabric and construction of masks, but washing is also key for protection.

Chandini Raina MacIntyre et al. Contamination and washing of cloth masks and risk of infection among hospital health workers in Vietnam: a post hoc analysis of a randomized controlled trial, BMJ Open (2020). DOI: 10.1136/bmjopen-2020-042045

https://medicalxpress.com/news/2020-10-masks-machine.html?utm_sourc...

Comment by Dr. Krishna Kumari Challa on October 10, 2020 at 6:12am

'Universal law of touch' will enable new advances in virtual reality

Seismic waves, commonly associated with earthquakes, have been used by scientists to develop a universal scaling law for the sense of touch.

Rayleigh waves are created by impact between objects and are commonly thought to travel only along surfaces. The team discovered that, when it comes to touch, the waves also travel through layers of skin and bone and are picked up by the body's touch receptor cells.

Using mathematical modelling of these touch receptors the researchers showed how the receptors were located at depths that allowed them to respond to Rayleigh waves. The interaction of these receptors with the Rayleigh waves will vary across species, but the ratio of receptor depth vs wavelength remains the same, enabling the universal law to be defined.

The team also found that the interaction of the waves and receptors remained even when the stiffness of the outermost layer of skin changed. The ability of the receptors to respond to Rayleigh waves remained unchanged despite the many variations in this outer layer caused by, age, gender, profession, or even hydration.

For most mammals, touch is the first sense to develop. They must feel vibrations on the surface of their skin to enable them to respond to various stimuli in their environment, a process called vibrotaction. But how do mammals perceive these vibrations? Through mathematical modeling of the skin and touch receptors, researchers showed that vibrotaction is dominated by “surface” Rayleigh waves traveling cooperatively through all layers of the skin and bone. Applying their model to experimental data, they identified a universal scaling law for the depth of touch receptors across multiple species, indicating an evolutionarily conserved constant in the sensation of vibrations.

 J.W. Andrews el al., "A universal scaling law of mammalian touch," Science Advances (2020). advances.sciencemag.org/lookup … .1126/sciadv.abb6912

https://phys.org/news/2020-10-universal-law-enable-advances-virtual...

Comment by Dr. Krishna Kumari Challa on October 10, 2020 at 5:49am

Study reveals that methods to infer the connectivity of neural circuits are affected by systematic errors

Researchers  have recently carried out a study investigating the effectiveness of existing methods for algorithmically estimating the wiring of neural networks. Their findings suggest that even the most sophisticated among these methods are biased and tend to infer connections between neurons that are not actually connected, but rather highly correlated.

Because it is difficult to directly measure the wiring diagrams of neural circuits, there has long been an interest in estimating them algorithmically from multicell activity recordings. But this study shows even sophisticated methods, applied to unlimited data from every cell in the circuit, are biased toward inferring connections between unconnected but highly correlated neurons. This failure to 'explain why' connections occurs when there is a mismatch between the true network dynamics and the model used for inference, which is inevitable when modeling the real world.

Abhranil Das et al. Systematic errors in connectivity inferred from activity in strongly recurrent networks, Nature Neuroscience (2020). DOI: 10.1038/s41593-020-0699-2

https://medicalxpress.com/news/2020-10-reveals-methods-infer-neural...

Comment by Dr. Krishna Kumari Challa on October 10, 2020 at 5:31am

Some Fish Can Regenerate Their Eyes. Know what? Mammals Have Those Genes Too to do that.

But, they are switched off! Scientists want to switch them on again.

Damage to the retina is the leading cause of blindness in humans, affecting millions of people around the world. Unfortunately, the retina is one of the few tissues we humans can't grow back. Unlike us, other animals such as zebrafish are able to regenerate this tissue that's so crucial to our power of sight. We share 70% of our genes with these tiny little zebrafish, and scientists have just discovered some of the shared genes include the ones that grant zebrafish the ability to grow back their retinas.

The genes activated were involved in containing the injury, calling in immune cells to clean up damaged tissue and fight off potential invaders.

But then, a network that suppresses these genes kicked in only in their mouse subjects, keeping them from transforming into cells that produce other kinds of retinal cells. Researchers suspect that the loss of this ability may be linked to a trade-off between regenerating central nervous system cells and parasite resistance. Glia help restrict the spread of infections, and if they're turned into neuron-producing cells, they can't do this.

The researchers also noticed that after a retinal injury glial cells in all three species stopped making nuclear factor I (NFI), a protein that stops the cell from accessing bits of DNA, essentially turning genes off.

But in mice, this molecule started appearing again fairly soon. So, the team stopped Müller glia cells producing NFI and the cells started making retinal neurons in adult mice after injury.

This is a highly complicated system with many independent mechanisms involved that need to be further explored. But understanding these pathways may one day allow scientists to help us better repair damaged sight.

Gene regulatory networks controlling vertebrate retinal regeneration

Comment by Dr. Krishna Kumari Challa on October 10, 2020 at 5:30am

A bird is male on one side and female on the other

Male rose-breasted grosbeaks have some red-pink feathers while females’ are yellow and brown

A rose-breasted grosbeak has a pink breast spot and a pink “wing pit” and black feathers on its right wing — tell tale shades of males. But on its left side, the songbird displays yellow and brown plumage, hues typical of females.

Gynandromorphs are found in many species of birds, insects and crustaceans such as crabs and lobsters. This bird is likely the result of an unusual event when two sperm fertilize an egg that has two nuclei instead of one. The egg can then develop male sex chromosomes on one side and female sex chromosomes on the other, ultimately leading to a bird with a testis and other male characteristics on one half of its body and an ovary and other female qualities on the other half.

Unlike hermaphrodites, which also have genitals of both sexes, gynandromorphs are completely male on one side of the body and female on the other.

We don’t yet know if these birds behave more like males or females, or if they can reproduce

R.J. Agate et al. Neural, not gonadal, origin of brain sex differences in a gynandrom.... Proceedings of the National Academy of Sciences. Vol. 100, April 15, 2003, p. 4873. doi: 10.1073/pnas.0636925100.

RESEARCHERS AT POWDERMILL NATURE RESERVE OBSERVE RARE GYNANDROMORPH BIRD CONTAINING BOTH MALE AND FEMALE CHARACTERISTICS - Carnegie Museum of Natural History

https://carnegiemnh.org/press/researchers-at-powdermill-nature-rese...

Comment by Dr. Krishna Kumari Challa on October 10, 2020 at 5:29am

More Humans Are Growing an Extra Artery in Our Arms, Showing We're Still Evolving

Researchers have noticed an artery that temporarily runs down the centre of our forearms while we're still in the womb isn't vanishing as often as it used to.

That means there are more adults than ever running around with what amounts to be an extra channel of vascular tissue flowing under their wrist.

Since the 18th century, anatomists have been studying the prevalence of this artery in adults and our study shows it's clearly increasing.

The prevalence was around 10 percent in people born in the mid-1880s compared to 30 percent in those born in the late 20th century, so that's a significant increase in a fairly short period of time, when it comes to evolution.

Recently increased prevalence of the human median artery of the forearm: A microevolutionary change

The median artery has been considered as an embryonic structure, which normally regresses around the 8th week of gestation. However, various prevalences have been reported in adults since the 18th century. Furthermore, in a study by Henneberg and George (1995; Am J Phys Anthropol 96, 329–334), has suggested that increasing prevalence of the median artery during the 20th century was a ‘possible secular trend’. The present study, conducted nearly a quarter of a century later, is a continuation of that study. A total of 26 median arteries were found in 78 upper limbs obtained from Australians aged 51 to 101 years, who died in the period 2015–2016, a prevalence rate of 33.3%. Analysis of the literature showed that the presence of the median artery has been significantly increasing (p = .001) over time, from approximately 10% in people born in the mid‐1880s to approximately 30% by the end of the 20th century. The significance of the prevalence increased to a p value

https://onlinelibrary.wiley.com/doi/epdf/10.1111/joa.13224

Comment by Dr. Krishna Kumari Challa on October 9, 2020 at 6:10am

This ‘squidbot’ jets around and takes pics of coral and fish

Comment by Dr. Krishna Kumari Challa on October 9, 2020 at 6:08am

Millimetre-precision drug delivery to the brain

Researchers  have developed a method for concentrating and releasing drugs in the brain with pinpoint accuracy. This could make it possible in the future to deliver psychiatric and cancer drugs and other medications only to those regions of the brain where this is medically desirable.

In order to prevent a drug from acting on the entire brain and body, the new method involves special drug carriers that wrap the drugs in spherical lipid vesicles attached to gas-​containing ultrasound-​sensitive microbubbles. These are injected into the bloodstream, which transports them to the brain. Next, the scientists use focused ultrasound waves in a two-​stage process. Focused ultrasound is already employed in oncology to destroy cancer tissue at precisely defined points in the body. In the new invention, however, the scientists work with much lower energy levels, which do not damage the tissue.

Ozdas MS, Shah AS, Johnson PM, Patel N, Marks M, Yasar TB, Stalder U, Bigler L, von der Behrens W, Sirsi SR, Yanik MF: Non-​invasive molecularly-​specific millimeterresolution manipulation of brain circuits by ultrasound-​mediated aggregation and uncaging of drug carriers. Nature Communications, 1 October 2020, doi: 10.1038/s41467-​020-18059-7

https://ethz.ch/en/news-and-events/eth-news/news/2020/10/millimetre...

https://researchnews.cc/news/2923/Millimetre-precision-drug-deliver...

Comment by Dr. Krishna Kumari Challa on October 9, 2020 at 5:47am

Stomach Acid & Heartburn Drugs Linked with COVID-19 Outcomes

While sick with COVID-19, President Trump is taking an antacid. Doctors have been exploring whether these medicines can treat SARS-CoV-2 infections, and the results are mixed.

The uncertainty of the COVID-19 pandemic has made our stomachs churn, and now, evidence suggests that intense heartburn may be linked with worse symptoms of the disease. Some drugs that neutralize stomach acid, such as famotidine, which President Donald Trump is taking, are associated with reduced severity, but others, such as Prilosec, correlate with higher infection rates and risk of death, at least in patients hospitalized with SARS-CoV-2 infections.

https://www.the-scientist.com/news-opinion/stomach-acid-heartburn-d...

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