Blue light from smartphones may speed blindness

Agencies
August 9, 2018

Washington, Aug 9: Blue light emitted from smartphones and other digital devices can accelerate blindness by transforming vital molecules in the eye's retina into cell killers, a study has found.

Macular degeneration, an incurable eye disease that results in significant vision loss starting on average in a person's 50s or 60s, is the death of photoreceptor cells in the retina.

Those cells need molecules called retinal to sense light and trigger a cascade of signalling to the brain.

"We are being exposed to blue light continuously, and the eye's cornea and lens cannot block or reflect it," said Ajith Karunarathne, an assistant professor at University of Toledo in the US.

"It's no secret that blue light harms our vision by damaging the eye's retina. Our experiments explain how this happens, and we hope this leads to therapies that slow macular degeneration, such as a new kind of eye drop," said Karunarathne.

The study, published in the journal Scientific Reports, found that blue light exposure causes retinal to trigger reactions that generate poisonous chemical molecules in photoreceptor cells.

"It's toxic. If you shine blue light on retinal, the retinal kills photoreceptor cells as the signalling molecule on the membrane dissolves," said Kasun Ratnayake, a PhD student researcher working in Karunarathne's group.

"Photoreceptor cells do not regenerate in the eye. When they're dead, they're dead for good," said Ratnayak.

Karunarathne introduced retinal molecules to other cell types in the body, such as cancer cells, heart cells and neurons. When exposed to blue light, these cell types died as a result of the combination with retinal. Blue light alone or retinal without blue light had no effect on cells.

"No activity is sparked with green, yellow or red light. The retinal-generated toxicity by blue light is universal. It can kill any cell type," Karunarathne said.

The researcher found that a molecule called alpha tocoferol, a Vitamin E derivative and a natural antioxidant in the eye and body, stops the cells from dying.

However, as a person ages or the immune system is suppressed, people lose the ability to fight against the attack by retinal and blue light.

"If you look at the amount of light coming out of your cell phone, it's not great but it seems tolerable," Dr. in the UT Department of Chemistry and Biochemistry, said.

"Some cell phone companies are adding blue-light filters to the screens, and I think that is a good idea," said John Payton, visiting assistant professor at University of Toledo.

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Agencies
June 17,2020

Leading physicians are celebrating a small dose of good news that arrived Tuesday about dexamethasone, a cheap and widely used steroid shown to be able to save lives among COVID-19 patients, but also cautioning against releasing study results by press release during a global health emergency, like in the case of the latest dexamethasone study by University of Oxford.

"It will be great news if dexamethasone, a cheap steroid, really does cut deaths by one-third in ventilated patients with COVID19, but after all the retractions and walk backs, it is unacceptable to tout study results by press release without releasing the paper", Atul Gawande, surgeon and CEO of Haven Healthcare, tweeted.

"Bottom line is, good news," Dr. Fauci, America's foremost infectious diseases expert told a US newswire on Tuesday, soon after the dexamethasone results were announced in the UK.

Fauci, who has long championed the therapeutics-first view said that dexamethasone is a "significant improvement" in the available therapeutic options currently available.

On Medical Twitter and Facebook, doctors broadly agree that dexamethasone use aligns well with the way COVID19 attacks the body's immune system. Fauci said the results in the Oxford study make "perfect sense" in that context.

"We should see the number of people who actually survive go up, if the study holds up," virologist and epidemiologist Dr. Joseph Fair told a television network.

Global coronavirus cases crossed 8 million on Tuesday. In the US, Texas and Florida are facing a new wave of cases after lifting lockdown orders earlier than medical experts recommended. Amidst the relentless graph upwards, the dexamethasone study results injected hope for better survival rates among those most seriously ill.

World Health Organization chief scientist Soumya Swaminathan welcomed the results from the randomised control trial.

Dr Eugene Gu, Founder and CEO of CoolQuit tweeted that he is "genuinely impressed" with the UK dexamethasone trial. This may be a "game changer", he wrote.

"There's no conflict of interest as dexamethasone is a generic steroid. The mechanism of action makes sense because steroids can reduce cytokine storms and overactive immune systems that makes COVID-19 so deadly. The number needed to treat is 8 ventilated patients which is great."

The Oxford study found that dexamethasone reduced deaths by 35 percent in patients who needed treatment with breathing machines and by 20 percent in those only needing supplemental oxygen. Dexamethasone was one of 5 drugs studied in a large clinical trial in the United Kingdom named RECOVERY, short for Randomised Evaluation of COVID-19 Therapy.

Peter Horby, chief investigator of the University of Oxford clinical trial, said dexamethasone is the first drug to be shown to improve survival in COVID-19. Details of the study have not been released. The trial organisers said they made their announcement via a news release because of "the public health importance of these results." According to Horby's public comments, there was a lot of initial resistance to studying steroids.

During the study, 2,104 patients were randomly selected to be given 6 milligrams of dexamethasone once a day (either by mouth or by intravenous injection) for 10 days. That group was compared with 4,321 patients who received the usual care alone.

Researchers estimated that dexamethasone would prevent one death for every eight patients treated while on ventilators and one for every 25 patients on extra oxygen alone.

UK experts have called the study results a breakthrough in the fight against the virus. The researchers have promised they would publish the results soon.

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News Network
January 31,2020

Jan 31: Cervical cancer could be eliminated worldwide as a public health issue within the next 100 years, according to two studies which may lead to better strategies for screening and vaccination against the malignant disease.

According to the studies, published in the journal The Lancet, more than 74 million cervical cancer cases, and 60 million deaths could be averted, and the disease eliminated in the 78 countries which have the highest disease burden.

The researchers, including those from Laval University in Canada, said cervical cancer is the second most frequent cancer among women in low-income and lower-middle-income countries (LMICs) with 2,90,000 (51 per cent) of the 5,70,000 new cases worldwide reported in women living in LMICs.

In the current studies, the scientists used the WHO draft strategy of cervical cancer elimination which defines plans for vaccination against the disease's causative agent, the human papillomavirus (HPV).

These plans, they explained, call for 90 per cent of girls to be vaccinated against HPV by 2030, and for 70 per cent of women to be screened for cervical cancer once or twice in their lifetime.

About 90 per cent of women with precancerous lesions, or cervical cancer are also advised to receive appropriate treatment, according to the WHO draft strategy, the scientists said.

In the second study, the research team analysed the impact of three elements of the WHO strategy on deaths from cervical cancer -- modelling the impact of scaling up cancer treatment, as well as vaccination and screening

"Our findings emphasise the importance of acting immediately to combat cervical cancer on all three fronts," said Karen Canfell from the University of Sydney in Australia, who co-led both the studies.

"In just 10 years, it's possible to reduce deaths from the disease by a third and, over the next century, more than 60 million women's lives could be saved. This would represent an enormous gain in terms of both quality of life, and lives saved," Canfell said.

By adding the two screening tests, and with the treatment of precancerous cervical lesions, cases of the cancer may drop by 97 per cent, and 72 million cervical cancer cases could be averted over the next century, the researchers said.

Scaling-up of appropriate cancer treatment could avert 62 million cervical cancer deaths, the study noted.

"For the first time, we've estimated how many cases of cervical cancer could be averted if WHO's strategy is rolled out and when elimination might occur," said Marc Brisson, study co-author from Laval University.

"Our results suggest that to eliminate cervical cancer it will be necessary to achieve both high vaccination coverage, and a high uptake of screening and treatment, especially in countries with the highest burden of the disease," Brisson added.

Based on the results of the studies, WHO's cervical cancer elimination strategy has been updated which will be presented for adoption at the World Health Assembly in May 2020, the scientists noted.

"If the strategy is adopted and applied by member states, cervical cancer could be eliminated in high income countries by 2040, and across the globe within the next century, which would be a phenomenal victory for women's health," Brisson said.

"However, this can only be achieved with considerable international financial and political commitment, in order to scale-up prevention and treatment," he added.

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Agencies
July 30,2020

New York, Jul 30: Can the coronavirus spread through the air? Yes, it's possible.

The World Health Organisation recently acknowledged the possibility that Covid-19 might be spread in the air under certain conditions.

Recent Covid-19 outbreaks in crowded indoor settings — restaurants, nightclubs and choir practices — suggest the virus can hang around in the air long enough to potentially infect others if social distancing measures are not strictly enforced.

Experts say the lack of ventilation in these situations is thought to have contributed to spread, and might have allowed the virus to linger in the air longer than normal.

In a report published in May, researchers found that talking produced respiratory droplets that could remain in the air in a closed environment for about eight to 14 minutes.

The WHO says those most at risk from airborne spread are doctors and nurses who perform specialized procedures such as inserting a breathing tube or putting patients on a ventilator.

Medical authorities recommend the use of protective masks and other equipment when doing such procedures.

Scientists maintain it's far less risky to be outside than indoors because virus droplets disperse in the fresh air, reducing the chances of Covid-19 transmission.

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