New molecule may reduce cellular damage after heart attack
LOS ANGELES, Jan 2: Scientists have developed molecules with the potential to deliver healing power to stressed cells - such as those involved in heart attacks, cancer and Alzheimers disease.
The research - done at a cellular level in the lab - involves the design of organic molecules that break down to release hydrogen sulphide when triggered by specific conditions such as increased oxidative stress.
Oxidative stress damages cells and is tied especially to heart disease and cancer, as well as Alzheimers and Parkinsons disease.
"We have discovered that small organic molecules can be engineered to release a molecule called carbonyl sulphide, which is the most prevalent sulphur-containing molecule in the atmosphere, but more importantly converts rapidly to hydrogen sulphide under biological conditions," said Michael Pluth, professor at University of Oregon in the US.
"We developed and demonstrated a new mechanism to release small molecules that provide therapeutic hydrogen sulphide," said Pluth.
Hydrogen sulphide, a colourless gas, has long been known for its dangerous toxicity - and its telltale smell of rotten eggs - in the environment, but it also is produced in mammals, including humans, with important roles in molecular signalling and cardiac health.
Researchers used benzyl thiocarbamates to design responsive organic molecules that release carbonyl sulphide.
They adapted the molecule so it remains nontoxic and stable until cellular conditions trigger it to release the carbonyl sulphide, which is converted to hydrogen sulphide by carbonic anhydrase enzymes in the body.
Finding a way to generate restorative hydrogen sulphide in the body has been a goal of many research labs around the world in the last two decades.
Researchers in 2013 developed a probe that detects the gas in biological samples, providing a framework to test potential donor molecules, either synthetically produced or isolated from natural products.
"To do that we need to develop new chemistry. We are synthetic chemists. We make molecules with the goal of developing new research tools or therapeutic tools," said Pluth.
"As for treating a disease, we are not there yet, but these cell-based studies suggest that those types of protective effects might be possible," he said.
During a heart attack or loss of blood flow, for example, increased levels of reactive oxygen species like hydrogen peroxide emerge, he added.
The recently developed donor molecules are programmed to react to the overexpression of reactive oxygen species.
Current hydrogen sulphide donors are generally slow-release molecules that donate hydrogen sulphide passively.
The research shows that it is possible to build molecular scaffolds to release carbonyl sulphide and then hydrogen sulphide by creating a trigger in the molecule to start the delivery process, researchers said.
There are no blue or green eyes. Everyone has brown, says expert
LONDON, Dec 18: Everyone has brown eyes and there are no blue or green colour eyes in real sense, an optometrist has said. There is only one pigment for eye colour, brown. Eye colours like blue, green, hazel, etc are what people might call an optical illusion. Pigments in our body are determined by something call melanin.
“Everyone has melanin in the iris of their eye, and the amount that they have determines their eye colour,” said Dr Gary Heiting, a licensed optometrist and senior editor of the eye care website All About Vision. “There’s really only (this) one type of pigment.”
Pigments in our body are determined by something call melanin. Irises are made up of a miniature version of melanin called melanocytes, which only come in one colour, brown, CNN reported. Even though all eyes are technically brown, the amount of melanocytes varies from person to person. There’s really only one “shade” of melanin - and it’s brown!, Heiting said.
However, people with lighter eyes have less melanocytes allowing light to be more easily absorbed and reflected, making their eyes appear lighter in colour. Brown-eyed people have more melanin, less light. The opposite is true for people with “blue” eyes. Those with less melanocytes cannot absorb as much light, so more light is reflected back out of the eye, Heiting was quoted as saying by the report.
This is called scattering - and when light is scattered, it reflects back at shorter wavelengths. On the colour spectrum, shorter light wavelengths correspond with the colour blue.
Almost half HIV infections worldwide undetected: WHO
GENEVA, Nov 29: The World Health Organization warned Tuesday that nearly half of all people with HIV around the globe do not know they are infected, and called for broader access to at-home testing kits.
The UN health agency said that 40 percent of people with the virus that causes AIDS, or more than 14 million people worldwide, are unaware of their status, according to 2015 estimates.
That marks a huge improvement over just a decade earlier, when only 12 percent of people with HIV were estimated to know they had the virus.
But the continued lack of diagnosis, remains a major obstacle to implementing WHO's recommendation for everyone with HIV to be offered anti-retroviral therapy, or ART.
Today, more than 80 percent of everyone diagnosed with HIV is receiving ART.
But WHO chief Margaret Chan warned that since so many people do not know their status, "millions of people with HIV are still missing out on life-saving treatment, which can also prevent HIV transmission to others."
"HIV self-testing should open the door for many more people to know their HIV status and find out how to get treatment and access prevention services," she said.
HIV self-testing means that people can, in the privacy of their own homes, use oral fluid or blood from a finger prick to determine their status in a matter of minutes.
WHO urges anyone who tests positive to seek confirmatory tests at a health clinic, where they can receive information about the disease and how to get counselling, as well as rapid referral to prevention, treatment and care services.
Self-testing has been shown to nearly double the frequency of HIV testing among men who have sex with men, and recent studies in Kenya found that the male partners of pregnant women were twice as likely to get tested if they were offered self-testing, WHO said.
"By offering HIV self-testing, we can empower people to find out their own HIV status and also to notify their partners and encourage them to get tested as well," Gottfried Hirnschall, head of WHO's HIV department, said in the statement.
Twenty-three countries currently have national policies in place supporting HIV self-testing, while others are developing such policies, but WHO warned that in much of the world wide-scale access to the tests remains limited.
The EU and WHO also reported Tuesday that one in seven people with HIV in Europe is unaware of their infection, as 2015 marked another record year for new HIV cases in the region.
Europe registered 153,407 new cases, up from 142,000 in 2014, the WHO said, a jump driven by cases in Russia and immigrants who acquired the virus after arrival.
The WHO regional office for Europe compiles data from 53 countries.
Cancer to kill 5.5 mn women a year by 2030: report
PARIS, Nov 1: Cancer will kill 5.5 million women - about the population of Denmark - per year by 2030, a near 60-per cent increase in less than two decades, a report said today.
As the global population grows and ages, the highest toll will be among women in poor and middle-income countries, it said, and much of it from cancers which are largely preventable.
"Most of the deaths occur in young- and middle-aged adults,", placing a heavy burden on families and national economies, said Sally Cowal, senior vice president of global health at the American Cancer Society, which compiled the report with pharmaceutical company Merck.
The review "highlights the large geographic inequality in availability of resources and preventive measures and treatment to combat the growing burden of cancer," she told AFP.
Cancer is already killing one in seven women around the world, said the report - the second highest cause of death after cardiovascular disease.
All four of the deadliest cancers - breast, colorectal, lung and cervical cancer - are mostly preventable or can be detected early, when treatment is more successful.
In poorer countries, a much smaller proportion of cancer cases are diagnosed and treated than in rich ones, while a much bigger group dies.
The relative burden is growing for developing countries as people live longer due to better basic healthcare.
Women in these countries are also increasingly exposed to known cancer risk factors "associated with rapid economic transition," said Cowal, "such as physical inactivity, unhealthy diet, obesity, and reproductive factors" such as postponing motherhood.
"Due to these changes, cancers that were once common only in high-income countries are becoming more prevalent," said the report entitled "The Global Burden of Cancer in Women."
It was presented today at the World Cancer Congress in Paris.
According to the International Agency for Research on Cancer, there were 6.7 million new cancer cases and 3.5 million deaths among women worldwide in 2012.
Of these, 56 per cent of cases and 64 per cent of deaths were in less developed countries.
"These numbers are expected to increase to 9.9 million cases and 5.5 million deaths among females annually by 2030 as a result of the growth and ageing of the population," said the new report.
The biggest concentration is in eastern Asia, with 1.7 million cases and a million deaths in 2012, mainly in China.
Walking, cycling can reduce your diabetes risk
WASHINGTON DC, Oct 18: Fast walking or cycling for recommended 150 minutes a week can reduce a person's risk of developing type 2 diabetes by up to 26 percent.
According to new research by UCL and the University of Cambridge, people who carry out an hour of moderate to vigorous exercise every day can reduce their risk of getting type 2 diabetes by 40 percent.
The study also revealed that any amount of physical activity can reduce the risk of developing the disease.
The research is the most comprehensive study to look at the impact of exercise, independent of other behavioural factors such as diet, on a person's risk of developing type 2 diabetes.
The UK Department of Health recommends 150 minutes of moderate to vigorous exercise a week, which includes brisk walking, gentle cycling or sports such as doubles tennis.
According to the Health Survey for England (2012), as many as a third of adults are not meeting this target.
The study, which analysed summarised data from over a million people, demonstrated that while any amount of physical activity is good for you, the benefits of exercise are greater for people who exceed this recommended level.
The study analysed data from 23 studies carried out in the USA, Asia, Australia and Europe. By combining observations from these studies, the researchers were able to separate out the effect of leisure time physical activity from other behavioural factors, and obtain better estimates of the effects of different physical activity levels.
Previous studies have often included changes to both diet and physical activity, making it difficult to isolate the impact of physical activity alone.
"Our results suggest a major potential for physical activity to slow down or reverse the global increase in type 2 diabetes and should prove useful for health impact modelling, which frequently forms part of the evidence base for policy decisions," said study leader Andrea Smith.
The prevalence of type 2 diabetes is growing rapidly due to rising obesity levels and is estimated to reach nearly 600 million cases worldwide by 2035.
"This research shows that some physical activity is good, but more is better," said co-author of the study Soren Brage.
"We already know that physical activity has a major role to play in tackling the growing worldwide epidemic of type 2 diabetes. These new results add more detail to our understanding of how changes in the levels of physical activity across populations could impact the incidence of disease. They also lend support to policies to increase physical activity at all levels. This means building environments that make physical activity part of everyday life," Brage added.