Blue sharks can change colour to camouflage say scientists
The research shows the secret to the blue shark's colour lies in the tooth-like scales on its skin.The guanine crystals act as blue reflectors while another structure, called melanosomes, absorb other wavelengths of colour. Professor Dean from the City University of Hong Kong said: "These components are packed into separate cells, reminiscent of bags filled with mirrors and bags with black absorbers, but kept in close association so they work together."When you combine these materials together, you also create a powerful ability to produce and change colour."
The researchers had to look at a shark's fin really closely under lots of powerful microscopes. They used simulations on a computer to recreate and understand the structures under different circumstances.Professor Dean continued: "Very fine scale alterations resulting from something as simple as humidity or water pressure changes could alter body colour, that then shape how the animal camouflages or counter-shades in its natural environment." The research suggests even something as simple as swimming deeper in the ocean could make the sharks look a deeper colour of blue as the guanine crystals are forced closer together with the increased pressure from the water.
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The Sun
a day ago
- The Sun
‘Game-changing' Alzheimer's drug could STOP disease in its tracks – as the ‘most powerful weapon' against condition yet
A NEW "game-changing" drug could stop the progression of Alzheimer's disease, early trials suggest. Scientists say the treatment - called trontinemab - could be the most powerful weapon yet against dementia, as they look into giving the drug to people with no symptoms in the hopes of preventing disease. 1 Phase two trial results for trontinemab were presented at he Alzheimer's Association International Conference in Toronto. Researchers said the drug seemed to clear plaques - the abnormal build-up of proteins around brain cells that cause damage and disrupt function - quicker than other drugs licensed to treat Alzheimer's. Trontinemab cleared out plaques and eliminated visible signs of the the disease within 28 weeks for nine out of 10 patients. Drug-maker Roche is now conducting another trial to see if plaque clearance also improves patients' memory. The 18-month study includes 1,600 people, the Telegraph reported. Separate research will examine whether the drug could be given to people without any signs of dementia, just as statins are used to ward off heart disease. Experts hope the drug could stop patients from developing dementia symptoms at all, if it is given early enough. They described the findings so far as 'very promising', suggesting that the drug was much more powerful than existing ones while leading to fewer side effects - as it was able to clear plaques better within seven months that other drugs can in 18 months. Roche's chief medical officer Levi Garraway said: 'Alzheimer's disease represents one of the greatest challenges in healthcare today and tackling it requires early detection and effective therapeutics. 'Trontinemab is designed to target a key driver of Alzheimer's disease biology more effectively in the brain. "Combining new treatment avenues with advanced diagnostics may enable earlier and potentially more effective intervention. "With plans for phase three trials in both early symptomatic and pre-clinical Alzheimer's disease, we are advancing science with the goal of delaying - and ultimately preventing - progression of this devastating condition.' Prof Sir John Hardy, the chairman of molecular biology of neurological disease at University College London's Institute of Neurology told the Telegraph trontinemab could be 'game-changing'. The scientist, who was the first to identify the role of amyloid plaques in Alzeheimer's, said: 'This is absolutely great news. "It sucks the plaque out of the brain really quickly, much faster than we have seen with lecanemab or donanemab.' Both are Alzheimer's drugs approved for used in the UK, which target amyloid proteins in the brain to slow disease progression. However, neither treatment is offered on the NHS, as the National Institute for Health and Care Excellence (Nice) deemed them too expensive - in large part because patients need frequent scans to monitor for brain swelling and bleeds. Prof Hardy added: 'There is no doubt [trontinemab] could be game-changing. "We hope that if we can use these drugs to people early, we can halt the progression of disease, even before people have symptoms. "Now we need to see the size of the clinical effect. 'These results show it is much faster and safer than previous drugs, which means less monitoring. "That brings down the cost significantly, it means fewer MRI scans, so that would surely mean it would get Nice approval.' Early signs of dementia It's not unusual for your memory to lapse a bit as you get older. But dementia is different from 'just getting old' as it will cause noticeable - rather than gradual - changes to mental abilities and make managing everyday tasks and activities increasingly difficult. The symptoms of dementia may be small to start with, but get worse over time. Below are some examples of possible signs. Memory loss Memory loss is a key sign of dementia. This can include: Forgetting something you were only recently told. You may ask for the same information repeatedly – for example, 'Are the doors locked?' Putting objects in unusual places – for example, putting your house keys in the refrigerator. Being unable to learn new tasks, like how to use a new washing machine. Planning and decision making issues People with dementia can have difficulty with planning and decision making. This can include: Getting very confused when planning or thinking things through. Struggling to stay focused on a single task. Not making informed, careful decisions when dealing with money or looking at risks. Finding it hard to manage regular payments, budgets or monthly bills. Problems with language and understanding In people with dementia, this can manifest as: Having frequent problems finding the right word or regularly referring to objects as 'that thing'. Finding it hard to take part in conversations. Regularly being unable to follow what someone is saying even without distractions. Losing sense of time and place Dementia can cause problems with orientation, including: Losing track of the date, season or the passage of time. Getting lost in a place that is familiar or that should be easy to find your way around – for example, a supermarket. Regularly being unable to follow what someone is saying even without distractions. Problems with vision and perception This can mean having problems making sense of what you see. For example, having difficulty judging distances on stairs, or mistaking reflections or patterns for other objects. Mood and behavioural changes Finally, dementia can also make people act differently or shift their mood. This can mean: Becoming withdrawn and losing interest in work, friends or hobbies. Feeling unusually sad, anxious, frightened or low in confidence. Getting easily upset at home, at work, with friends or in places that usually feel comfortable or familiar. Trials for lecanemab and donanemab showed the drugs helped clear toxic clumps out of the brain and slow nerve damage caused by Alzheimer's by 27 per cent and 35 per cent respectively, over the course of 18 months. But the treatments did present a risk of brain swelling and brain bleeds, meaning patients needed intense monitoring. Trontinemab appears to be safer and cause fewer side effects, with less than five per cent of patients showing abnormal results on their brain scans. All of these cases were quickly resolved, researchers said. The drug - administered by infusion into the bloodstream - also doesn't need to be given a frequently. Upcoming trials will examine the impact of giving the drug to patients once a month for six months, then every three months. Trontinemab has been designed to efficiently bypass the blood-brain barrier, a protective layer of cells that stops harmful substances in the blood stream from attacking the brain and spinal cord. This barrier can make it hard for many drugs to reach the brain. Prof Jonathan Schott, the chief medical officer at Alzheimer's Research UK, told the Telegraph: 'We urgently need a range of treatments for Alzheimer's that are effective and safe for the people affected by this devastating disease. 'Evidence presented at the Alzheimer's Association conference in Toronto on trontinemab is very promising, showing that the drug can effectively and rapidly clear amyloid from the brain, seemingly with very few side effects. 'We now need to see whether these early stage results carry through to later stage clinical trials, which are planned to start later this year, including in the UK. "These trials will show whether the drug is not only safe, but impacts on memory, thinking and quality of life.' He said it was 'exciting' that the drug would now be tested in some people without symptoms under the phase three trials.
Telegraph
a day ago
- Telegraph
Obesity fuels surge in liver cancer
Obesity is helping to fuel a surge in liver cancer cases around the world, academics have warned. The number of new cases of liver cancer globally is set to double from 0.87 million in 2022 to 1.52 million in 2050, according to projections published as part of a new Lancet Commission on Liver Cancer paper. A team of experts, led by academics in Hong Kong, said the proportion of liver cancers caused by the disease's most common cause – the Hepatitis B virus – is set to reduce over the coming years. Cases caused by the Hepatitis C virus are also expected to decline proportionately. However, liver cancer cases caused by alcohol and obesity are set to increase. Experts predicted that by 2050, some 21 per cent of liver cancers will be caused by alcohol. And 11 per cent will be caused by a severe form of metabolic dysfunction-associated steatotic liver disease (MASLD) – known as fatty liver disease, where excessive fat builds up in a person's liver. The severe form of this condition is called metabolic dysfunction-associated steatohepatitis. The research team points out that 60 per cent of liver cancers are preventable. The researchers also said that global deaths from liver cancer are expected to rise from 760,000 in 2022 to 1.37 million in 2050. 'These data suggest that preventive measures targeting a comprehensive number of risk factors for hepatocellular carcinoma are sorely needed,' the team of experts wrote. The main treatment for MASLD is a balanced diet, being physically active and potentially losing weight. Prof Jian Zhou, chairman of the commission from Fudan University in China, said: 'Liver cancer is a growing health issue around the world. 'It is one of the most challenging cancers to treat, with five-year survival rates ranging from approximately five per cent to 30 per cent. 'We risk seeing close to a doubling of cases and deaths from liver cancer over the next quarter of a century without urgent action to reverse this trend.' Professor Stephen Chan, of the Chinese University of Hong Kong, who was the first author of the study, added: 'As three in five cases of liver cancer are linked to preventable risk factors, mostly viral hepatitis, alcohol and obesity, there is a huge opportunity for countries to target these risk factors, prevent cases of liver cancer and save lives.' Commenting on the study, Pamela Healy, chief executive of the British Liver Trust, said: 'Liver cancer is the fastest-rising cause of cancer death in the UK, and just 13 per cent of people diagnosed will survive for five years or more. 'We know that the biggest risk factors are having pre-existing liver cirrhosis or viral hepatitis, and this new analysis highlights that MASLD, also known as fatty liver disease, is expected to be linked to an increasing number of cases. 'As well as improving early detection through surveillance of people with cirrhosis, it is essential that we tackle these underlying causes and prioritise public health. 'By supporting people to maintain a healthy weight, cut down on alcohol and get tested and treated for hepatitis, we can prevent many cases of liver cancer and save lives.' In 2022, some 64 per cent of adults in England were estimated to be overweight or obese.
The Guardian
a day ago
- The Guardian
Sight of someone potentially infectious causes immune response, research suggests
Whether it's the person brandishing a tissue on the train or the child with the telltale signs of chickenpox, the threat of an infection can be enough for us to beat a retreat. Now researchers using virtual reality avatars have shown that the mere sight of a potentially contagious person is enough to mobilise our immune system too. 'Although surprising, our finding that immune responses can be triggered by simulated infections presented in VR is consistent with the principle of the smoke detector in biological systems,' the authors said, adding the behavioural system that helps us avoid catching diseases is 'exquisitely sensitive' to cues that may suggest someone is sick. Writing in the journal Nature Neuroscience, the researchers reported how they fitted 248 healthy people with VR headsets and carried out five experiments, each involving a minimum of 32 participants. In each experiment, participants initially watched three faces of the same sex as themselves repeatedly loom towards them, bearing a neutral expression. Participants were then split into groups and shown the same three faces multiple times, either with a neutral expression or signs of viral infections such as skin rashes. In some experiments, an additional subset of participants were shown the faces displaying an expression of fear. In one experiment, participants were asked to press a button as fast as possible after receiving a mild touch to their face while an avatar was shown. The team found that when the avatars showed signs of sickness, participants pressed the button when the faces appeared further away than for faces showing a neutral or fearful expression. Results from EEG tests to investigate the electrical activity of the brain tallied with these findings. As expected, as avatars loomed closer, the brain system that represents the space closely surrounding our body became activated. However, this activation differed when the avatars showed signs of infection compared with neutral expressions, even when they appeared far away. These differences, the team add, were localised in areas of the brain involved in detecting and filtering threats. The team found that functional MRI (fMRI) brain scans supported these results, further revealing that when infectious avatars were shown there was a greater connection between this threat-detection network and part of the brain called the hypothalamus, which acts as a key regulation centre for the body. The team also found differences in participants' blood when they were shown the infectious avatars compared with neutral or fearful faces. '[In terms of cells], we saw mainly that there is an activation of an immune cell family called the innate lymphoid cells (ILCs)that [are] early responders in immunity to basically alarm other immune cells,' said Prof Camilla Jandus of the University of Geneva and an author of the study. The team added that they found a similar activation of ILCs when they examined the blood of individuals who had received an influenza vaccine but had not been exposed to the VR setup. Dr Esther Diekhof of the University of Hamburg, who was not involved in the work, said the study chimed with previous research, including that of her own team. 'The study provides yet another good example for the existence of a mechanism that responds to potential contagion threats even before the immune system has come into contact with pathogens,' she said. But Prof Benedict Seddon, of University College London, said questions remained, including whether the observed responses help the immune system actually fight an infection. 'When we get infected, by Sars-CoV for instance, it can take a day or two for the infection to establish and for the immune system to become aware of it and respond, a long time after the initial encounter that stimulated this short-lived mobilisation,' he said.
