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Comment by Dr. Krishna Kumari Challa on November 7, 2024 at 11:28am

Research in Thailand supports stool DNA as non-invasive alternative for colorectal cancer screening

A recent prospective cross-sectional study  demonstrates that multitarget stool DNA testing is highly sensitive and specific for detecting colorectal cancer (CRC) among  individuals. Researchers  think that this testing method could serve as a viable non-invasive alternative to colonoscopy, especially in settings where colonoscopy is less accessible or less accepted by patients.

Researchers focused on evaluating the diagnostic performance of the multitarget stool DNA testing for detecting CRC and advanced adenoma, using colonoscopy as the reference standard. The study included both asymptomatic and symptomatic patients who underwent stool DNA testing followed by colonoscopy. The multitarget stool DNA test targeted methylation statuses of SDC2, ADHFE1, and PPP2R5C genes. Sensitivity, specificity, and other diagnostic parameters were analyzed.

In the study, data from 274 patients (mean age 62 years, with a predominantly female cohort at 60.6%) was evaluated. Colorectal cancer was identified in 17.2% of participants, while 6.2% were found to have advanced adenomas, which are precursors to cancer.

The multitarget stool DNA test, a non-invasive screening method, yielded impressive results: it detected CRC with a sensitivity of 91.5% and a specificity of 90.3%, accurately identifying cancer in over 90% of cases. The test's sensitivity was consistent across both right-sided and left-sided colon lesions, at 92.3% and 91.2%, respectively.

For advanced colorectal neoplasms, which include both CRC and advanced adenomas, the test demonstrated a sensitivity of 75% and a specificity of 91.9%, marking it as a promising tool for the early detection of serious colorectal conditions. These findings highlight the test's potential as an effective screening option for detecting CRC, especially for larger lesions, although some limitations remain for detecting smaller-sized abnormalities.

BGI Genomics' COLOTECT stool DNA testing kits were used for sample and raw data collection. COLOTECT is a non-invasive tool for early colorectal cancer detection based on DNA methylation testing, targeting the methylation profile of colorectal exfoliated cells to assess the risk of colorectal cancer and advanced adenomas.

This tool requires no special equipment, imposes no dietary restrictions, and is entirely non-invasive. In recent years, DNA methylation-based colorectal cancer detection has gained recognition, being incorporated into multiple CRC screening guidelines and expert consensus worldwide.

Varut Lohsiriwat et al, Diagnostic Accuracy of Multitarget Stool DNA Test for Colorectal Cancer Screening and Detecting in Thailand, Asian Pacific Journal of Cancer Prevention (2024). DOI: 10.31557/APJCP.2024.25.10.3661

Comment by Dr. Krishna Kumari Challa on November 7, 2024 at 11:24am

Fecal transplants may involve more than bacterial transfer, study suggests

In a novel study that identified male chromosome genetic material in the intestines of female patients undergoing fecal transplants, researchers  say they have significantly expanded scientific understanding of how some of these transplants may succeed and work.

Fecal microbiota transplant, or FMT, is a procedure in which stool from healthy donors is transplanted via colonoscopy into the bowels of people with dangerous and recurrent infections caused by a bacterium called Clostridioides difficile (C. difficile). Many previous studies show that the transplanted fecal material from healthy donors restores the balance of good bacteria that are markers of a healthy gut in people whose recurrent C.difficile infections have been treated with heavy duty antibiotics that wipe out "good" bacteria as well as bad.

Recurrent C. difficile infection is an often debilitating condition marked by severe diarrhea and inflammation of the colon. Researchers say the infections are notoriously difficult to treat, with conventional antibiotic therapies often failing to provide long-term relief and cure of the infection.

The new study, described in the journal Gastro Hep Advances on October 18, shows that transfer donor cells that line the intestinal tract along with the donor's fecal matter may be responsible for improved outcomes for at least some patients.

This study suggests the possibility of donor intestinal epithelial cell transfer during fecal microbiota transplant, rather than the mere transfer of bacteria from donor fecal samples, can be more effective.

Donor intestinal epithelial cells live in the inner lining of the colon and the small intestine. These cells maintain the intestine's structural integrity and functional capacity. Humans shed millions of these cells into the fecal stream every day. In the new study, the researchers found that the SRY gene responsible for the male-defining characteristics of Y chromosomes, along with evidence of the Y chromosome itself, was detected in the fecal samples of some female patients receiving FMT from male donors.

The long-term detection of the Y chromosome suggests that, in addition to the intestinal microbiota restoration, FMT may facilitate epithelial repair in the gut lining resulting in the altered milieu of the intestinal ecosystem. These observations open up a deeper understanding of the mechanism by which FMT works.

This research points to a much more complex interaction between the donor microbiome and the recipient's gut environment than previously reported.

This finding suggests that stool is a much more complex excretion than we thought it was.

However, more studies are needed in a larger group of female patients who receive FMT from healthy male donors to determine the extent of epithelial "engraftment" in the intestines of FMT patients.

Sudhir K. Dutta et al, Detection of human Y chromosome and SRY gene in fecal samples of female patients following fecal microbiota transplantation, Gastro Hep Advances (2024). DOI: 10.1016/j.gastha.2024.10.008

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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

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