Fish eyes may hold key to blindness cure: study

March 11, 2017

Washington, Mar 11: Scientists, including one of Indian-origin, have identified a chemical signal in the zebrafish brain that helps it regenerate retina, a finding that may help cure blindness in humans.

fisheye

The discovery raises the possibility that human retinas can be induced to regenerate, naturally repairing damage caused by degenerative retinal diseases and injury, including age-related macular degeneration and retinitis pigmentosa, researchers said.

"The prevailing belief has been that the regeneration process in fish retinas is triggered by secreted growth factors, but our results indicate that the neurotransmitter GABA might initiate the process instead," said James Patton, Professor at Vanderbilt University in the US.

"All the regeneration models assume that a retina must be seriously damaged before regeneration takes place, but our studies indicate that GABA can induce this process even in undamaged retinas," said Patton.

It turns out that the structure of the retinas of fish and mammals are basically the same.

Although the retina is very thin - less than 0.5 millimetres thick - it contains three layers of nerve cells: photoreceptors that detect the light, horizontal cells that integrate the signals from the photoreceptors and ganglion cells that receive the visual information and route it to the brain.

In addition, the retina contains a special type of adult stem cell, called Muller glia, that span all three layers and provide mechanical support and electrical insulation. In fish retinas, they also play a key role in regeneration.

When regeneration is triggered, the Muller glia dedifferentiate, begin proliferating, and then differentiate into replacements for the damaged nerve cells. Muller glia are also present in mammalian retinas, but do not regenerate.

Graduate student Mahesh Rao got the idea that GABA - normally a fast-acting neurotransmitter best known for its role of calming nervous activity by inhibiting nerve transmission in the brain - might be the trigger for retinal regeneration.

He was inspired by the results of a study in the mouse hippocampus which found that GABA was controlling stem cell activity.

Working with Patton and assistant professor Dominic Didiano, Rao designed a series of experiments with zebrafish which determined that high concentrations of GABA in the retina keep the Miller glia quiescent and that they begin dedifferentiating and proliferating when GABA concentrations drop.

They tested their hypothesis in two ways: By blinding zebrafish and injecting them with drugs that stimulate GABA production and by injecting normal zebrafish with an enzyme that lowers the GABA levels in their eyes.

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Agencies
June 22,2020

A team of scientists has produced first open source all-atom models of full-length COVID-19 Spike protein that facilitates viral entry into host cells – a discovery that can facilitate a faster vaccine and antiviral drug development.

The group from Seoul National University in South Korea, University of Cambridge in the UK and Lehigh University in the US produced the first open-source all-atom models of a full-length S protein.

The researchers say this is of particular importance because the S protein plays a central role in viral entry into cells, making it a main target for vaccine and antiviral drug development.

"Our models are the first full-length SARS-CoV-2 spike (S) protein models that are available to other scientists," said Wonpil Im, a professor in Lehigh University.

"Our team spent days and nights to build these models very carefully from the known cryo-EM structure portions. Modeling was very challenging because there were many regions where simple modeling failed to provide high-quality models," he wrote in a paper published in The Journal of Physical Chemistry B.

Scientists can use the models to conduct innovative and novel simulation research for the prevention and treatment of Covid-19.

Though the coronavirus uses many different proteins to replicate and invade cells, the Spike protein is the major surface protein that it uses to bind to a receptor.

The total number of global COVID-19 cases was nearing 9 million, while the deaths have increased to over 467,000, according to the Johns Hopkins University.

With 2,279,306 cases and 119,967 deaths, the US continues with the world's highest number of COVID-19 infections and fatalities, according to the CSSE.

Brazil comes in the second place with 1,083,341 infections and 50,591 deaths.

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Agencies
July 2,2020

London, Jul 2: The World Health Organisation says smoking is linked to a higher risk of severe illness and death from the coronavirus in hospitalised patients, although it was unable to specify exactly how much greater those risks might be.

In a scientific brief published this week, the U.N. health agency reviewed 34 published studies on the association between smoking and Covid-19, including the probability of infection, hospitalisation, severity of disease and death.

WHO noted that smokers represent up to 18% of hospitalised coronavirus patients and that there appeared to be a significant link between whether or not patients smoked and the severity of disease they suffered, the type of hospital interventions required and patients' risk of dying.

In April, French researchers released a small study suggesting smokers were at less risk of catching Covid-19 and planned to test nicotine patches on patients and health workers — but their findings were questioned by many scientists at the time who cited the lack of definitive data.

WHO says "the available evidence suggests that smoking is associated with increased severity of disease and death in hospitalized Covid-19 patients. It recommends that smokers quit.

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Agencies
April 28,2020

As the world grapples with the impact of the novel coronavirus, daily interaction with the outside world --- public and retail spaces, restaurants, educational institutions, and even with each other has been and will continue to be reoriented prioritising personal hygiene and public health.

The sensibilities are building towards and leading to major changes in how the country's food service industry is expected to operate.

Based on a recent consumer survey by restaurant tech platform, Dineout, Indian diners are now ranking safety assurances and premier hygiene as top factors when it comes to choosing a restaurant to dine in.

The survey by Dineout conducted across 20 cities revealed that in a post-COVID-19 era, 81 per cent diners will prefer digital menus at restaurants, while 77 per cent of people will continue to want to dine out.

The survey found that 23 per cent people would prefer continuing with delivery/takeaway and online payment becomes the most preferred option with 60 per cent votes.
 
Diner's response to Contactless Dining:

 

Over 96 per cent demand better waitlist management
 
81 per cent consumers would rather scan a QR on their phone to place an order instead of handling physical menus or tablet-based digital menus.
 
After a dining experience, 60 per cent prefer seamless wallet-based digital payments over cash/cards 85 per cent would choose a digital valet over waiting in possibly contaminated public spaces and 84 per cent would prefer offering digital feedback over physical feedback collection.

 

What do people want to eat?
 
The report also revealed that most of India has been craving Pizza since the lockdown, except in Chennai, Hyderabad and Kolkata where their popular and indigenous Biryani recipes reign supreme. 
 
Which restaurants are diners waiting to go to?
 
77 per cent respondents claimed that they are waiting to dine out with friends and family once the lockdown is lifted.
 
Big Chill, Barbeque Nation and Social emerged as favourites in Delhi, while Mumbaikars picked Global Fusion, Poptates and Asia Kitchen. Bangaloreans miss going to pubs like Toit, Vapour and Barbeque Nation.
 
Aminia, Arsalan and Momo I Am emerge as the top picks in Kolkata.
 
Contrary to popular belief, Delhitties picked vegetarian over non-vegetarian food.
 
Bangaloreans and Lucknowis would rather have their drinks over food.
 
Besides the new parameters for restaurant selection, the factors deciding consumer delight have also seen a major overhaul as hygiene takes precedence. Consumers would prefer that the total number of reservations in a certain period be limited with the option to pre-select the seating, ample amounts of sanitisers at tables along with UV sanitised utensils whenever possible.
 
Hygiene ratings with detailed hygiene information, regular hygiene checks & usage of mask and disposable gloves by waiters are likely to be the new standard, with diners expecting service personnel to sanitise tables & chairs after every use.
 
Dineout recently unveiled the �contactless dining suite' to help restaurants survive and thrive in a post-COVID-19 world. The brand will also provide PPE Safety Kits to Restaurants to help ensure hygiene measures and is facilitating COVID free certification for restaurants through a licensed lab to ensure all microbiological tests are in place before restaurants restart post the lockdown.

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