Tag: 19/12/24

Study Likely to Change Standard of Care for Deadly Vertebrobasilar Stroke

Ischaemic and haemorrhagic stroke. Credit: Scientific Animations CC4.0

Endovascular therapy (EVT), a minimally invasive surgery performed inside the blood vessels, is 2 ½ times more likely than standard medical management to achieve a positive outcome after vertebrobasilar stroke that affects the back of the brain, including the brain stem. A meta-analysis of four randomised clinical trials, published in The Lancet, was led by UPMC Stroke Institute director Raul Nogueira, MD.

Investigators from the US, Netherlands and China formed a multi-centre collaboration of all four randomised trials of EVT in vertebrobasilar occlusion with data that provides the strongest evidence to date of the benefits of EVT over alternative approaches for complicated vessel obstructions in life-sustaining areas of the brain.

Although vertebrobasilar artery occlusions interrupting blood flow in the back of the brain account for only a small fraction of all ischaemic strokes, they are especially deadly. Without an appropriate intervention, vertebrobasilar strokes lead to high rates of severe disability and mortality that may exceed 70%.

“While the overwhelming benefit of EVT for acute ischaemic strokes due to occlusions of large vessels that supply the anterior brain has been well established, the benefit of this therapy for vertebrobasilar artery occlusion, one of the most devastating forms of stroke, has been more controversial,” said Nogueira, endowed professor of neurology and neurosurgery at the University of Pittsburgh.

To address this uncertainty, the consortium of investigators, called VERITAS, focused on providing more precise, comprehensive and statistically powered estimates of the benefits of EVT with a particular focus on specific patient subgroups of clinical interest.

As the primary coordinating centre for the study, the Pitt team established common variables, definitions and trial specifications that laid the groundwork for a core pooled dataset from the four randomised controlled clinical trials ATTENTION, BAOCHE, BASICS and BEST of EVT for stroke due to vertebrobasilar artery occlusion.

Meta-analysis showed that at three months after the surgery, despite higher rates of brain bleeds with the procedure, EVT significantly reduced patient mortality and overall post-stroke disability, increasing patients’ functional independence. Notably, patients who underwent EVT were nearly 2 ½ times more likely to regain their ability to walk independently compared to patients who received the current medical standard of care, including intravenous thrombolytics.

“The results of the VERITAS collaboration are expected to influence treatment guidelines and impact stroke care globally,” Nogueira said. “We hope that this analysis sets the foundation for improved recovery after vertebrobasilar strokes and helps more people regain their independence after this catastrophic medical event.”

Source: University of Pittsburgh

How Processing Depletes the Nutrients in Milk Substitutes

Photo by Pixabay on Pexels

A University of Copenhagen study of plant-based drinks reveals a common issue: they are lacking in proteins and essential amino acids compared to cow’s milk. The explanation lies in their extensive processing, causing chemical reactions that degrade protein quality in the product and, in some cases, produce new substances of concern.

Over the last decade, the global market for plant-based beverages has seen remarkable growth, with oat, almond, soy and rice drinks emerging as popular alternatives to cow’s milk in coffee and oatmeal during this time.

One of the likely reasons for millions of litres of plant-based drinks ending up in the shopping baskets of consumers is that their climate footprint is often lower than that of cow’s milk. But consumers would be mistaken if they considered plant-based beverages healthier than cow’s milk. This is highlighted in a new study conducted by the University of Copenhagen in collaboration with the University of Brescia, Italy.

In the study, published in Food Research International, researchers examined how chemical reactions during processing affect the nutritional quality of ten different plant-based drinks, comparing them with cow’s milk. The overall picture is clear:

“We definitely need to consume more plant-based foods. But if you’re looking for proper nutrition and believe that plant-based drinks can replace cow’s milk, you’d be mistaken,” says Department of Food Science professor Marianne Nissen Lund, the study’s lead author.

Long shelf life at the expense of nutrition

While milk is essentially a finished product when it comes out of a cow, oats, rice, and almonds require extensive processing during their conversion to a drinkable beverage. Moreover, each of the plant-based drinks tested underwent Ultra High Temperature (UHT) treatment, a process that is widely used for long-life milks around the world. In Denmark, milk is typically found only in the refrigerated sections of supermarkets and is low-pasteurized, meaning that it receives a much gentler heat treatment. 

“Despite increased plant-based drink sales, cow milk sales remain higher. Consequently, plant-based drinks undergo more intense heat treatments than the milk typically sold in Denmark, in order to extend their shelf life. But such treatment comes at a cost,” says Marianne Nissen Lund.

UHT treatment triggers a so-called “Maillard reaction”, a chemical reaction between protein and sugar that occurs when food is fried or roasted at high temperatures. Among other things, this reaction impacts the nutritional quality of the proteins in a given product.

“Most plant-based drinks already have significantly less protein than cow’s milk. And the protein, which is present in low content, is then additionally modified when heat treated. This leads to the loss of some essential amino acids, which are incredibly important for us. While the nutritional contents of plant-based drinks vary greatly, most of them have relatively low nutritional quality,” explains the professor.

For comparison, the UHT-treated cow’s milk used in the study contains 3.4 grams of protein per liter, whereas 8 of the 10 plant-based drinks analyzed contained between 0.4 and 1.1 grams of protein. The levels of essential amino acids were lower in all plant-based drinks. Furthermore, 7 out of 10 plant-based drinks contained more sugar than cow’s milk.

Heat treatment may produce carcinogens

Besides reducing nutritional value, heat treatment also generates new compounds in plant-based drinks. One such compound measured by the researchers in four of the plant-based drinks made from almonds and oats is acrylamide, a carcinogen that is also found in bread, cookies, coffee beans and fried potatoes, including French fries.

“We were surprised to find acrylamide because it isn’t typically found in liquid food. One likely source is the roasted almonds used in one of the products. The compound was measured at levels so low that it poses no danger. But, if you consume small amounts of this substance from various sources, it could add up to a level that does pose a health risk,” says Marianne Nissen Lund.

Additionally, the researchers detected α-dicarbonyl compounds and hydroxymethylfurfural (HMF) in several of the plant-based drinks. Both are reactive substances that could potentially be harmful to human health when present in high concentrations, although this is not the case here.

While professor of nutrition Lars Ove Dragsted is not particularly concerned about the findings either, he believes that the study highlights how little we know about the compounds formed during food processing:

“The chemical compounds that result from Maillard reactions are generally undesirable because they can increase inflammation in the body. Some of these compounds are also linked to a higher risk of diabetes and cardiovascular diseases. Although our gut bacteria break down some of them, there are many that we either do not know of or have yet to study,” says Lars Ove Dragsted of the Department of Nutrition, Execercise and Sports.

Professor Dragsted adds: “This study emphasizes why more attention should be paid to the consequences of Maillard reactions when developing plant-based foods and processed foods in general. The compounds identified in this study represent only a small fraction of those we know can arise from Maillard reactions.”

Make Your Own Food

According to Professor Marianne Nissen Lund, the study highlights broader issues with ultra-processed foods: 

“Ideally, a green transition in the food sector shouldn’t be characterized by taking plant ingredients, ultra-process them, and then assuming a healthy outcome. Even though these products are neither dangerous nor explicitly unhealthy, they are often not particularly nutritious for us either.”

Her advice to consumers is to: “generally opt for the least processed foods and beverages, and to try to prepare as much of your own food as possible. If you eat healthy to begin with, you can definitely include plant-based drinks in your diet – just make sure that you’re getting your nutrients from other foods.”

At the same time, Professor Lund hopes that the industry will do more to address these issues:
“This is a call to manufacturers to further develop their products and reconsider the extent of processing. Perhaps they could rethink whether UHT treatment is necessary or whether shorter shelf lives for their products would be acceptable.”

Source: University of Copenhagen

Researchers Develop New Test for Early Osteoarthritis Diagnosis

Photo by Mehmet Turgut Kirkgoz on Unsplash

Diagnosing osteoarthritis often occurs in the late stages when cartilage degradation is severe, making it difficult to distinguish it from other types of arthritis and to determine the best treatment plan. In work published in the Journal of Orthopaedic Research, investigators have developed and tested a new diagnostic test that uses two markers found in the synovial fluid of patients’ joints.

After assessing levels of cartilage oligomeric matrix protein and interleukin‐8, the team came up with an algorithm based on the ratio of these two markers and validated its efficacy in differentiating osteoarthritis from inflammatory arthritis in 171 human knee synovial fluid specimens.

“This study addresses an unmet need for objective diagnosis of osteoarthritis to improve clinical decision-making and patient outcomes,” said corresponding author Daniel Keter, BA, of CD Diagnostics, A Division of Zimmer Biomet.

Source: Wiley

AI Developed “Beer Goggles” Looking at Knee X-rays

Photo by Pavel Danilyuk on Pexels

Medicine, like most fields, is transforming as the capabilities of artificial intelligence expand at lightning speed. AI integration can be a useful tool to healthcare professionals and researchers, including in interpretation of diagnostic imaging. Where a radiologist can identify fractures and other abnormalities from an X-ray, AI models can see patterns humans cannot, offering the opportunity to expand the effectiveness of medical imaging.

A study led by Dartmouth Health researchers, in collaboration with the Veterans Affairs Medical Center in White River Junction, VT, and published in Nature’s Scientific Reports, highlights the hidden challenges of using AI in medical imaging research. The study examined highly accurate yet potentially misleading results – a phenomenon known as “shortcut learning.”

Using knee X-rays from the Osteoarthritis Initiative, researchers demonstrated that AI models could “predict” unrelated and implausible traits, such as whether patients abstained from eating refried beans or drinking beer. While these predictions have no medical basis, the models achieved surprising levels of accuracy, revealing their ability to exploit subtle and unintended patterns in the data.

“While AI has the potential to transform medical imaging, we must be cautious,” said Peter L. Schilling, MD, MS, an orthopaedic surgeon at Dartmouth Health’s Dartmouth Hitchcock Medical Center (DHMC) and an assistant professor of orthopaedics in Dartmouth’s Geisel School of Medicine, who served as senior author on the study. “These models can see patterns humans cannot, but not all patterns they identify are meaningful or reliable. It’s crucial to recognize these risks to prevent misleading conclusions and ensure scientific integrity.”

Schilling and his colleagues examined how AI algorithms often rely on confounding variables – such as differences in X-ray equipment or clinical site markers to make predictions – rather than medically meaningful features. Attempts to eliminate these biases were only marginally successful: the AI models would just “learn” other hidden data patterns.

The research team’s findings underscore the need for rigorous evaluation standards in AI-based medical research. Over-reliance on standard algorithms without deeper scrutiny could lead to erroneous clinical insights and treatment pathways.

“This goes beyond bias from clues of race or gender,” said Brandon G. Hill, a machine learning scientist at DHMC and one of Schilling’s co-authors. “We found the algorithm could even learn to predict the year an X-ray was taken. It’s pernicious; when you prevent it from learning one of these elements, it will instead learn another it previously ignored. This danger can lead to some really dodgy claims, and researchers need to be aware of how readily this happens when using this technique.”

“The burden of proof just goes way up when it comes to using models for the discovery of new patterns in medicine,” Hill continued. “Part of the problem is our own bias. It is incredibly easy to fall into the trap of presuming that the model ‘sees’ the same way we do. In the end, it doesn’t. It is almost like dealing with an alien intelligence. You want to say the model is ‘cheating,’ but that anthropomorphizes the technology. It learned a way to solve the task given to it, but not necessarily how a person would. It doesn’t have logic or reasoning as we typically understand it.”

To read Schilling and Hill’s study – which was also authored by Frances L. Koback, a third-year student at the Geisel School of Medicine at Dartmouth – visit bit.ly/4gox9jq.

Source: Dartmouth College

Books Beat TV When it Comes to Brain Health

…but is that any surprise?

Photo by Nong on Unsplash

It’s that time of the year when most of us get the chance to sit back and enjoy some well-deserved down time. But whether you reach for the TV controller, or a favourite book, your choice could have implications for your long-term brain health, say researchers at the University of South Australia who published their research in the Journals of Gerontology.

Assessing the 24-hour activity patterns of 397 older adults (aged 60+), researchers found that the context or type of activity that you engage in, matters when it comes to brain health. And specifically, that some sedentary (or sitting) behaviours are better for cognitive function than others.

When looking at different sedentary behaviours, they found that social or mentally stimulating activities such as reading, listening to music, praying, crafting, playing a musical instrument, or chatting with others are beneficial for memory and thinking abilities. Yet watching TV or playing video games are detrimental.

Researchers believe that there is likely a hierarchy of how sedentary behaviours relate to cognitive function, in that some have positive effects while others have negative effects.

It’s a valuable insight that could help reduce risks of cognitive impairment, particularly when at least 45% of dementia cases could be prevented through modifiable lifestyle factors.

In Australia, about 411,100 people (or one in every 1000 people) are living with dementia. Nearly two-thirds are women. Globally, the World Health Organization estimates that more than 55 million people have dementia with nearly 10 million new cases each year.

UniSA researcher Dr Maddison Mellow says that not all sedentary behaviours are equal when it comes to memory and thinking ability.

“In this research, we found that the context of an activity alters how it relates to cognitive function, with different activities providing varying levels of cognitive stimulation and social engagement,” Dr Mellow says.

“We already know that physical activity is a strong protector against dementia risk, and this should certainly be prioritised if you are trying to improve your brain health. But until now, we hadn’t directly explored whether we can benefit our brain health by swapping one sedentary behaviour for another.

“We found that sedentary behaviours which promote mental stimulation or social engagement — such as reading or talking with friends — are beneficial for cognitive function, whereas others like watching TV or gaming have a negative effect. So, the type of activity is important.

“And, while the ‘move more, sit less’ message certainly holds true for cardiometabolic and brain health, our research shows that a more nuanced approach is needed when it comes to thinking about the link between sedentary behaviours and cognitive function.”

Now, as the Christmas holidays roll around, what advice do researchers have for those who really want to indulge in a myriad of Christmas movies or a marathon of Modern Family?

“To achieve the best brain health and physical health benefits, you should prioritise movement that’s enjoyable and gets the heart rate up, as this has benefits for all aspects of health,” Dr Mellow says.

“But even small five-minute time swaps can have benefits. So, if you’re dead set on having a Christmas movie marathon, try to break up that time with some physical activity or a more cognitively engaged seated activity, like reading, at some point. That way you can slowly build up healthier habits.”

Source: University of South Australia

What is the Drug Captagon and How is it Linked to Syria’s Fallen Assad Regime?

Photo by James Coleman on Unsplash

Nicole Lee, Curtin University

After the fall of the al-Assad regime in Syria, large stockpiles of the illicit drug captagon have reportedly been uncovered.

The stockpiles, found by Syrian rebels, are believed to be linked to al-Assad military headquarters, implicating the fallen regime in the drug’s manufacture and distribution.

But as we’ll see, captagon was once a pharmaceutical drug, similar to some of the legally available stimulants we still use today for conditions including attention-deficit hyperactivity disorder (ADHD).

Captagon was once a pharmaceutical

Captagon is the original brand name of an old synthetic pharmaceutical stimulant originally made in Germany in the 1960s. It was an alternative to amphetamine and methamphetamine, which were both used as medicines at the time.

The drug has the active ingredient fenethylline and was initially marketed for conditions including ADHD and the sleeping disorder narcolepsy. It had a similar use to some of the legally available stimulants we still use today, such as dexamphetamine.

Captagon has similar effects to amphetamines. It increases dopamine in the brain, leading to feelings of wellbeing, pleasure and euphoria. It also improves focus, concentration and stamina. But it has a lot of unwanted side effects, such as low-level psychosis.

The drug was originally sold mostly in the Middle East and parts of Europe. It was available over the counter (without a prescription) in Europe for a short time before it became prescription-only.

It was approved only briefly in the United States before becoming a controlled substance in the 1980s, but was still legal for the treatment of narcolepsy in many European countries until relatively recently.

According to the International Narcotics Control Board pharmaceutical manufacture of Captagon had stopped by 2009.

The illicit trade took over

The illegally manufactured version is usually referred to as captagon (with a small c). It is sometimes called “chemical courage” because it is thought to be used by soldiers in war-torn areas of the Middle East to help give them focus and energy.

For instance, it’s been reportedly found on the bodies of Hamas soldiers during the conflict with Israel.

Its manufacture is relatively straightforward and inexpensive, making it an obvious target for the black-market drug trade.

Black-market captagon is now nearly exclusively manufactured in Syria and surrounding countries such as Lebanon. It’s mostly used in the Middle East, including recreationally in some Gulf states.

It is one of the most commonly used illicit drugs in Syria.

A recent report suggests captagon generated more than US$7.3 billion in Syria and Lebanon between 2020 and 2022 (about $2.4 billion a year).

What we know about illicit drugs generally is that any seizures or crackdowns on manufacturing or sale have a very limited impact on the drug market because another manufacturer or distributor pops up to meet demand.

So in all likelihood, given the size of the captagon market in the Middle East, these latest drug discoveries and seizures are likely to reduce manufacture only for a short time.

Nicole Lee, Adjunct Professor at the National Drug Research Institute (Melbourne based), Curtin University

This article is republished from The Conversation under a Creative Commons license. Read the original article.