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Comment by Dr. Krishna Kumari Challa on November 7, 2024 at 10:20am

'Potential misdiagnosis is just a click away': Researchers find design flaws and oversight issues in certain health apps

AI-powered apps offering medical diagnoses at the click of a button are often limited by biased data and a lack of regulation, leading to inaccurate and unsafe health advice, a new study found.

 Researchers presented symptom data from known medical cases to two popular, representative apps to see how well they diagnosed the conditions. While the apps sometimes gave correct diagnoses, they often failed to detect serious conditions, according to findings published in the Journal of Medical Internet Research. This potentially resulted in delayed treatment.

The researchers identified two main issues with the health apps they studied: biased data and a lack of regulation.

The bias issue is known as the "garbage in, garbage out" problem.

These apps often learn from skewed datasets that don't accurately reflect diverse populations.

Because the apps rely on data from smartphone users, they tend to exclude lower-income individuals. Race and ethnicity are also underrepresented in the data, said the authors. This creates a cycle where an app's assessments are based on a narrower group of users, leading to more biased results and potentially inaccurate medical advice.

While apps often include disclaimers stating they do not provide medical advice, the scholar argues that users' interpretations of these disclaimers—if read—do not always align.

The second issue is the "black box" nature of AI systems, where the technology evolves with minimal human oversight. Researchers say lack of transparency means even an app's developers may not fully understand how it reaches conclusions.

Without clear regulations, developers aren't held accountable, making doctors reluctant to recommend these tools. For users, this means a potential misdiagnosis is just a click away.

Ma'n H Zawati et al, Does an App a Day Keep the Doctor Away? AI Symptom Checker Applications, Entrenched Bias, and Professional Responsibility, Journal of Medical Internet Research (2024). DOI: 10.2196/50344

Comment by Dr. Krishna Kumari Challa on November 7, 2024 at 9:49am

Drowsy driving: Not taken as seriously as drunk driving, but it can kill

Some time back my brother-in-law who did two back to back night shifts, actually they 're 48 hour nonstop work shifts, at Airport (he 's  Airport manager for his International  airlines) was driving his car and told us temporarily felt drowsy and hit a person on the road. Luckily the person just fell down with and had just two light bruises but demanded money and my brother in law had to part with Rs.10000 as compensation. From then onwards he has been refusing to work continuously for more than 24 hours. 

Folks are more likely to drive drowsy than drive drunk, even though both raise the risk of a fatal crash, a new survey now shows confirming his fears.

About four in 10 adults say they'll find alternative transportation when they haven't gotten enough sleep, according to a poll conducted online.

By comparison, nearly seven in 10 adults say they won't drive after having a few drinks.

Drowsy driving is a significant threat to road safety, just like drunk, drugged or distracted driving can be, according to scientific studies.

Researchers want the public to know that sleeping only three to four hours before driving is like having a few drinks, and encourage everyone to have a backup plan in place for when they are not alert enough to drive safely, like choosing ride share or taxi options, or calling friends and family to help you and others stay safe.

Drowsy driving is responsible for one in every five deadly motor vehicle crashes, and one of every 10 crashes that result in hospitalization, according to the AAA Foundation for Traffic Safety.

A survey also found that:

• Only half of adults are likely to delay or change plans to avoid driving drowsy, compared to more than eight in 10 following a few drinks
• Just 50% are likely to avoid driving when they haven't gotten enough sleep, compared to almost 90% who've had a few drinks
• More people have urged someone else not to drive because of drinking than for being too tired

Being awake and alert in the driver's seat is as important as not being under the influence, so don't hesitate to change your plans when you shouldn't drive.

To avoid drowsy driving, the NSF recommends that people:

• Get seven to nine hours of sleep
• Plan long trips with a companion who can help a driver stay alert and take the wheel when necessary
• Schedule regular stops every 100 miles or two hours
• Be mindful of warning signs like frequent blinking, yawning or having difficulty with lane and speed control

Source: https://www.nhtsa.gov/risky-driving/drowsy-driving

Comment by Dr. Krishna Kumari Challa on November 7, 2024 at 9:36am

Dentists are pulling 'healthy' and treatable teeth to profit from implants, experts warn

Dental implants have been used for more than half a century to surgically replace missing or damaged teeth with artificial duplicates, often with picture-perfect results. While implant dentistry was once the domain of a small group of highly trained dentists and specialists, tens of thousands of dental providers now offer the surgery and place millions of implants each year.

Amid this booming industry, some implant experts worry that many dentists are losing sight of dentistry's fundamental goal of preserving natural teeth and have become too willing to remove teeth to make room for expensive implants, according to a months-long investigation by KFF Health News and CBS News.

In interviews, 10 experts said they had each given second opinions to multiple patients who had been recommended for mouths full of implants that the experts ultimately determined were not necessary.

Separately, lawsuits filed have alleged that implant patients  have experienced painful complications that have required corrective surgery, while other lawsuits alleged dentists at some implant clinics have persuaded, pressured, or forced patients to remove teeth unnecessarily.

The experts warn that implants, for a single tooth or an entire mouth, expose patients to costs and surgery complications, plus a new risk of future dental problems with fewer treatment options because their natural teeth are forever gone.

There are many cases where teeth're perfectly fine, and they're being removed unnecessarily.

2024 KFF Health News. Distributed by Tribune Content Agency, LLC.

https://medicalxpress.com/news/2024-11-dentists-healthy-treatable-t...

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Comment by Dr. Krishna Kumari Challa on November 7, 2024 at 9:27am

Biologists discover how plants evolved multiple ways to override genetic instructions

Biologists  have discovered the origin of a curious duplication that gives plants multiple ways to override instructions that are coded into their DNA. This research could help scientists exploit a plant's existing systems to favor traits that make it more resilient to environmental changes, like heat or drought stress.

This new research focuses on DNA methylation, a normal biological process in living cells wherein small chemical groups called methyl groups are added to DNA. This activity controls which genes are turned on and off, which in turn affects different traits—including how organisms respond to their environments.

Part of this job involves silencing, or turning off, certain snippets of DNA that move around within an organism's genome. These so-called jumping genes, or transposons, can cause damage if not controlled. The entire process is regulated by enzymes, but mammals and plants have developed different enzymes to add methyl groups.

Mammals only have two major enzymes that add methyl groups in one DNA context, but plants actually have multiple enzymes that do that in three DNA contexts.

The question is—why do plants need extra methylation enzymes?

Certain genes or combinations of genes are contributing to certain features or traits. If researchers find precisely how they are regulated, then they can find a way to innovate  technology for crop improvement.

Jianjun Jiang et al, Substrate specificity and protein stability drive the divergence of plant-specific DNA methyltransferases, Science Advances (2024). DOI: 10.1126/sciadv.adr2222. www.science.org/doi/10.1126/sciadv.adr2222

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Comment by Dr. Krishna Kumari Challa on November 7, 2024 at 9:14am

Pathogens that cling to microplastics may survive wastewater treatment

Wastewater treatment fails to kill several human pathogens when they hide out on microplastics in the water, reports a study published November 6, 2024 in the open-access journal PLOS ONE.

Wastewater treatment plants are designed to remove contaminants from wastewater, but microplastics persist and can become colonized by a sticky microbial biofilm. Previous research has suggested that these microbial communities, called plastispheres, include potential pathogens, and thus might pose a risk to human health and the environment when treated wastewater and sludge are released.

In the new study, researchers identified food-borne pathogens in plastispheres living on three types of plastic in wastewater. They cultured the microorganisms and used genetic techniques to understand the diversity and members of the plastisphere communities.

The team found evidence of pathogenic bacteria and viruses, including Listeria monocytogenes, Escherichia coli, norovirus and adenovirus. They also successfully grew Klebsiella pneumoniae and Acinetobacter spp. from raw and treated wastewater, indicating that the plastisphere biofilms likely protect the pathogens from wastewater treatment.

These findings highlight the potential of plastispheres to harbor and spread pathogens, which poses a challenge to safely reusing wastewater. Without efficient wastewater treatment and plastic waste management, wastewater could act as a vehicle for transferring plastic-associated pathogens into the food chain.

The researchers emphasize that continued research and innovation are essential to remove microplastics—and their pathogens—from wastewater.

 Wastewater-associated plastispheres: A hidden habitat for microbial pathogens?, PLOS ONE (2024). DOI: 10.1371/journal.pone.0312157

Comment by Dr. Krishna Kumari Challa on November 7, 2024 at 9:07am

Waste Heat to Electricity

Comment by Dr. Krishna Kumari Challa on November 7, 2024 at 8:52am

Climate change is contributing to drought in the American West even without rainfall deficits, scientists find

Higher temperatures caused by anthropogenic climate change made an ordinary drought into an exceptional drought that parched the American West from 2020–2022. A study by UCLA and National Oceanic and Atmospheric Administration climate scientists has found that evaporation accounted for 61% of the drought's severity, while reduced precipitation only accounted for 39%. The research found that evaporative demand has played a bigger role than reduced precipitation in droughts since 2000, which suggests droughts will become more severe as the climate warms.

Research has already shown that warmer temperatures contribute to drought, but this is the first study that actually shows that moisture loss due to demand is greater than the moisture loss due to lack of rainfall," say the authors of a study published in Science Advances.

For generations, drought has been associated with drier-than-normal weather. This study further confirms we've entered a new paradigm where rising temperatures are leading to intense droughts, with precipitation as a secondary factor.

A warmer atmosphere holds more water vapour before the air mass becomes saturated, allowing water to condense and precipitation to form. In order to rain, water molecules in the atmosphere need to come together. Heat keeps water molecules moving and bouncing off each other, preventing them from condensing. This creates a cycle in which the warmer the planet gets, the more water will evaporate into the atmosphere—but the smaller fraction will return as rain. Therefore, droughts will last longer, cover wider areas and be even drier with every little bit that the planet warms.

 Yizhou Zhuang et al, Anthropogenic warming has ushered in an era of temperature-dominated droughts in the western United States, Science Advances (2024). DOI: 10.1126/sciadv.adn9389

Comment by Dr. Krishna Kumari Challa on November 7, 2024 at 8:43am

Researchers show astrocytes in the brain play a role in memory retrieval

A study published in Nature by researchers  changes the way we understand memory. Until now, memories have been explained by the activity of brain cells called neurons that respond to learning events and control memory recall.

The present work  expanded this theory by showing that non-neuronal cell types in the brain called astrocytes—star-shaped cells—also store memories and work in concert with groups of neurons called engrams to regulate storage and retrieval of memories.

The researchers show that during learning events, such as fear conditioning, a subset of astrocytes in the brain expresses the c-Fos gene. Astrocytes expressing c-Fos subsequently regulate circuit function in that brain region.

The c-Fos-expressing astrocytes are physically close with engram neurons.

Furthermore, the researchers found that engram neurons and the physically associated astrocyte ensemble are also functionally connected. Activating the astrocyte ensemble specifically stimulates synaptic activity or communication in the corresponding neuron engram. This astrocyte-neuron communication flows both ways; astrocytes and neurons depend on each other.

The team also found that astrocytes activated by learning events have elevated levels of the NFIA protein, and preventing NFIA production in these astrocytes suppresses memory recall. Importantly, this suppression is memory specific.

These findings speak to the nature of the role of astrocytes in memory.

Benjamin Deneen, Learning-associated astrocyte ensembles regulate memory recall, Nature (2024). DOI: 10.1038/s41586-024-08170-w. www.nature.com/articles/s41586-024-08170-w

Comment by Dr. Krishna Kumari Challa on November 7, 2024 at 8:26am

Those featured circles, ecDNAs, are small and often contain a few genes on their circular DNA. Frequently, these genes are cancer-associated genes called oncogenes. When a cancer cell contains multiple oncogene-encoding ecDNAs, they can supercharge the cell's growth and allow it to evade internal checkpoints meant to regulate cell division.

The ecDNAs also sometimes encode genes for proteins that can tamp down the immune system's response to a developing cancer—further advantaging tumor growth.
Until recently, it was thought that only about 2% of tumors contained meaningful amounts of ecDNA. But in 2017, research showed that the small circles were widespread and likely to play a critical role in human cancers.

In 2023, researchers further showed that their presence jumpstarts a cancerous transformation in precancerous cells.

In the first of the three papers researchers built on 2017 finding by analyzing the prevalence of ecDNA in nearly 15,000 cancer patients and 39 tumor types.

They found that 17.1% of tumors contained ecDNA, that ecDNA was more prevalent after targeted therapy or cytotoxic treatments like chemotherapy, and that the presence of ecDNA was associated with metastasis and poorer overall survival.

The researchers also showed that the circles can contain not just cancer-driving oncogenes and genes that modulate the immune response, but also that others can contain only DNA sequences called enhancers that drive the expression of genes on other circles by linking two or more ecDNAs together.
The ecDNAs with enhancer elements don't confer any benefit to the cell on their own; they have to work with other ecDNAs to spur cancer cell growth. If looked at through a conventional lens, the presence of ecDNAs that solely encode enhancers wouldn't seem to be a problem. But the teamwork and physical connection between different types of circles is actually very important in cancer development."
Through these studies researchers learned critical lessons about which cancer patients are affected and what genes or DNA sequences are found in ecDNAs. They identified the genetic backgrounds and mutational signatures that give them clues as to how cancers originate and thrive.

Howard Chang, Coordinated inheritance of extrachromosomal DNAs in cancer cells, Nature (2024). DOI: 10.1038/s41586-024-07861-8. www.nature.com/articles/s41586-024-07861-8

Paul Mischel, Enhancing transcription–replication conflict targets ecDNA-positive cancers, Nature (2024). DOI: 10.1038/s41586-024-07802-5. www.nature.com/articles/s41586-024-07802-5

Charles Swanton, Origins and impact of extrachromosomal DNA, Nature (2024). DOI: 10.1038/s41586-024-08107-3. www.nature.com/articles/s41586-024-08107-3

Part2

Comment by Dr. Krishna Kumari Challa on November 7, 2024 at 8:19am

Cracking the code of DNA circles in cancer: Scientists uncover potential therapy

A trio of research papers from Stanford Medicine researchers and their international collaborators transforms scientists' understanding of how small DNA circles—until recently dismissed as inconsequential—are major drivers of many types of human cancers.

The papers, published simultaneously in Nature on Nov. 6, detail the prevalence and prognostic impact of the circles, called ecDNA for extrachromosomal DNA, in nearly 15,000 human cancers; highlight a novel mode of inheritance that overthrows a fundamental law of genetics; and describe an anti-cancer therapy targeting the circles that is already in clinical trials.

The team, jointly known as eDyNAmiC, are a group of international experts led by professor of pathology Paul Mischel, MD. In 2022, Mischel and the eDyNAmiC team were awarded a grant to learn more about the circles.

Cancer Grand Challenges, a research initiative co-founded by Cancer Research UK and the National Cancer Institute in the United States, supports a global community of interdisciplinary, world-class research teams to take on cancer's toughest challenges.

We're in the midst of a completely new understanding of a common and aggressive mechanism that drives cancer, say these scientists. 

Each paper alone is noteworthy, and taken together they represent a major inflection point in how we view cancer initiation and evolution.

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