Comment

Comment by Dr. Krishna Kumari Challa on February 19, 2025 at 2:27pm

Comment by Dr. Krishna Kumari Challa on February 19, 2025 at 11:33am

Swimming in some lakes can lead to infection with Legionella, warn scientists

Swimming in some lakes with still water can lead to infection with Legionella, bacteria that can cause pneumonia, and people who engage in open water swimming should be aware of this risk, say the authors of a practice article published in the Canadian Medical Association Journal.

Legionella infection represents a public health hazard owing to its ability to spread through exposure to natural water bodies and human-made water reservoirs.

Legionella infection is an atypical cause of community-acquired pneumonia. Referred to as legionnaires' disease, it presents with fever, fatigue, respiratory symptoms, and sometimes diarrhea. Legionella bacteria thrive in the warm, stagnant water in plumbing systems, air conditioners, public spas, and even lakes and rivers.

Risk factors for legionnaires' disease include age older than 50 years, smoking history, chronic cardiovascular or kidney disease, diabetes, and a compromised immune system.

 Legionnaires' disease following lake swimming in Iowa, Canadian Medical Association Journal (2025). DOI: 10.1503/cmaj.241086. www.cmaj.ca/lookup/doi/10.1503/cmaj.241086

Comment by Dr. Krishna Kumari Challa on February 19, 2025 at 11:28am

Using CRISPR to remove extra chromosomes in Down syndrome

Gene editing techniques may eventually allow trisomy to be treated at the cellular level, according to an in vitro proof-of-concept study.

Down syndrome is caused by the presence of a third copy of the 21st chromosome. The condition occurs in approximately 1 in 700 live births and is relatively easy to diagnose at early stages of development. However, there are no treatments.

Researchers used the CRISPR-Cas9 gene editing system to cleave the third chromosome in previously generated trisomy 21 cell lines derived from both pluripotent cells and skin fibroblasts. The technique is able to identify which chromosome has been duplicated, which is necessary to ensure the cell does not end up with two identical copies after removal, but instead has one from each parent. 

The study is published in the journal PNAS Nexus.

The researchers were able to remove duplicate chromosomes from both induced pluripotent stem cells and fibroblasts. Suppressing chromosomal DNA repair ability increased the rate of duplicate chromosome elimination.

The authors show that the chromosomal rescue reversibly restores both gene expression and cellular phenotypes. The approach is not yet ready for in vivo application, however, in part because the current technique can also change the retained chromosomes.

Similar approaches could eventually be used in neurons and glial cells and form the basis of novel medical interventions for people with Down syndrome, say the researchers.

Ryotaro Hashizume et al, Trisomic rescue via allele-specific multiple chromosome cleavage using CRISPR-Cas9 in trisomy 21 cells, PNAS Nexus (2025). DOI: 10.1093/pnasnexus/pgaf022

Comment by Dr. Krishna Kumari Challa on February 19, 2025 at 11:17am

Scientists decode diet from stool DNA

You can cheat your strict and disciplined parents or partner, you can lie to your doctor or people who make surveys but you cannot escape from scientists!

Scientists have developed a breakthrough method to track diet using stool metagenomic data.

Developed by researchers at the Institute for Systems Biology (ISB), the new method, called MEDI (Metagenomic Estimation of Dietary Intake), detects food-derived DNA in stool samples to estimate dietary intake. MEDI leverages stool metagenomics, which refers to sequencing all the DNA present in fecal samples (including microbial, human, and food-derived DNA). This non-invasive, data-driven approach offers an objective alternative to traditional food diaries and questionnaires, which are still the gold standard in dietary assessment but can suffer from misreporting and compliance issues.

 Metagenomic estimation of dietary intake from human stool, Nature Metabolism (2025). DOI: 10.1038/s42255-025-01220-1

Comment by Dr. Krishna Kumari Challa on February 19, 2025 at 11:14am

Dream recall, defined as the probability of waking up in the morning with impressions and memories from a dream experience, showed considerable variability between individuals and was influenced by multiple factors. The study revealed that people with a positive attitude toward dreams and a tendency for mind-wandering were significantly more likely to recall their dreams. Sleep patterns also seemed to play a critical role: individuals who experienced longer periods of light sleep had a greater likelihood of waking with a memory of their dreams.
Younger participants showed higher rates of dream recall, while older individuals often experienced "white dreams" (a sensation of having dreamed without recalling any details). This suggests age-related changes in memory processes during sleep. Moreover, seasonal variations emerged, with participants reporting lower dream recall during winter compared to spring, hinting at the potential influence of environmental or circadian factors.
The findings suggest that dream recall is not just a matter of chance but a reflection of how personal attitudes, cognitive traits, and sleep dynamics interact.

The individual determinants of morning dream recall, Communications Psychology (2025). DOI: 10.1038/s44271-025-00191-z

Part 2

Comment by Dr. Krishna Kumari Challa on February 19, 2025 at 11:11am

What makes us remember our dreams? How sleep patterns and mindset shape recall

Some people wake up vividly recalling their dreams from the night, and can tell precise stories experienced during the night, while others struggle to remember even a single detail. Why does this happen? A new study, conducted by researchers  and published in Communications Psychology explores the factors that influence so-called "dream recall"—the ability to remember dreams upon awakening—and uncovers which individual traits and sleep patterns shape this phenomenon.

The reason why there is such a difference in recalling dreams remains a mystery. Some studies found that women, young persons, or people with a tendency to daydream, tend to better recall night dreams. But other studies did not confirm these findings.

Other hypotheses, such as that personality traits or cognitive abilities count, received even less support from data. During the recent COVID pandemic, the phenomenon of individual differences in morning dream recall attracted renewed public and scientific attention when an abrupt surge in morning dream recall was reported worldwide.

The new research was conducted in the years from 2020 to 2024, and involved over 200 participants, aged 18 to 70, who recorded their dreams daily for 15 days while their sleep and cognitive data were tracked using wearable devices and psychometric tests.

Each study participant was given a voice recorder to report, every day right after the awakening, about the experiences they had during sleep. Participants had to report whether they remembered having dreamed or not, if they had the impression of having dreamed but did not remember anything about the experience, and to describe the content of the dream if they were able to remember it.

For the duration of the study, participants also wore an actigraph, a sleep monitoring wristwatch that detects sleep duration, efficiency, and disturbances. At the beginning and end of the dream recording period, participants were subjected to psychological tests and questionnaires that measure various factors, from anxiety levels to interest in dreams, proneness to mind-wandering (the tendency to frequently shift attention away from the task at hand toward unrelated thoughts, or internal reflections), up to memory and selective attention tests.

part 1

Comment by Dr. Krishna Kumari Challa on February 19, 2025 at 10:40am

Burning plastic for cooking and heating: An emerging environmental crisis

A new research paper  "The Use of Plastic as a Household Fuel among the Urban Poor in the Global South" published in Nature Cities, has called for action to reduce the burning of plastics for heating and cooking, a common yet hazardous practice emerging in millions of households in developing nations due to a lack of traditional energy sources.

Researchers investigated the energy consumption of developing countries in Africa, Asia and Latin America, finding many were unable to afford clean fuels such as gas or electricity.

The team also found urban sprawl had made traditional fuels such as wood and charcoal difficult to find, while a lack of waste management meant plastic waste was in abundance.

Burning plastic releases harmful chemicals such as dioxins, furans and heavy metals into the air, which can have a range of health and welfare impacts such as lung diseases, the researchers point out.

These risks are particularly pronounced among women and children, as they spend more time at home.

But the pollution doesn't just stay in households who burn it: it spreads across neighborhoods and cities, affecting everyone.

The issue may affect millions of people who bear the burden of acute inequality in cities and could potentially have a bigger impact as plastic use increases and cities grow.

And many governments are not addressing the issue effectively because it's usually concentrated in areas such as slums, which are often neglected.

Possible ways to address the problem include subsidies for cleaner fuels to make them affordable for poorer families, better waste management to prevent plastic from piling up in slum areas, education campaigns to inform communities about the dangers of burning plastic and alternative low-cost, innovative cooking solutions tailored to lower-income areas, say the experts.

Bishal Bharadwaj et al, The use of plastic as a household fuel among the urban poor in the Global South, Nature Cities (2025). DOI: 10.1038/s44284-025-00201-5

Comment by Dr. Krishna Kumari Challa on February 19, 2025 at 9:21am

Biologists transform gut bacteria into tiny protein pharmacies

Hundreds of different species of microbes live in your gut. In the future, one of these might serve a new function: microscopic in-house pharmacist.

A new study published Feb. 18 in Nature Biotechnology shows how  gut bacteria can be directed to produce and release proteins within the lower gastrointestinal tract—eliminating a major roadblock to delivering drugs to that part of the body.

Oral medication is the most common and practical means of drug administration, but the stomach doesn't let much pass through unscathed. This is good when it comes to things like foodborne pathogens, but gut-focused therapies are regularly deactivated and flushed out.

In an unprecedented workaround, biologists engineered bacteria-eating viruses called phages to infect and reprogram bacterial cells to produce and release a sustained flow of a protein-based drug. Collaborating with immunologists they showed that this approach can be used to potentially treat chronic diseases.

Bacteriophages (phages for short) are viruses that naturally infect bacteria. Phages are harder to classify than bacteria and therefore less understood, but we do know how they attack bacteria.

After attaching to a bacterial cell, phages inject their own DNA and reprogram the cell so that it manufactures more phages—agents of the cell's own destruction. When the bacterial cell eventually succumbs, it explodes into a flood of new phages in a process called lysis. Millions of these events happening simultaneously produce a constant supply of a targeted protein inside the lower intestine.

Even though phages act (and look) like spider aliens, they are regular players on the gut-microbiome home team. 

So Biologists  engineered special phages that inject a little extra genetic material into the bacterial cell.

In addition to making a flurry of new phages, the instructions prompt the cell to produce a tagalong protein that can lend itself to targeted therapies inside the lower intestines.

Engineered proteins reduced inflammation and obesity in mice.

Nature Biotechnology (2025). DOI: 10.1038/s41587-025-02570-7. www.nature.com/articles/s41587-025-02570-7

Comment by Dr. Krishna Kumari Challa on February 19, 2025 at 9:15am

A commentary by Timothy Boyce and Ian Han at the University of Iowa, "Hyperacute Outer Retinal Dysfunction—A Retina on Fire," also published in JAMA Ophthalmology, suggests that HORD may represent a novel inflammatory-mediated retinal disorder.

The authors propose similarities with autoimmune encephalitis, suggesting a possible antibody-mediated mechanism. Early OCT findings, including vitritis, vascular sheathing, and intraretinal hyperreflective dots, point to acute inflammation as a potential driver of retinal damage.

Yizhe Cheng et al, Hyperacute Outer Retinal Dysfunction, JAMA Ophthalmology (2025). DOI: 10.1001/jamaophthalmol.2024.6372

Timothy M. Boyce et al, Hyperacute Outer Retinal Dysfunction—A Retina on Fire, JAMA Ophthalmology (2025). DOI: 10.1001/jamaophthalmol.2024.6488

Part 2

Comment by Dr. Krishna Kumari Challa on February 19, 2025 at 9:14am

Sudden vision loss in children: Study  points to a novel retinal disorder

A multicenter study led by researchers from the  Key Laboratory of Ophthalmology  has characterized a distinct retinal disorder in children following high fever illness. The study describes hyperacute outer retinal dysfunction (HORD), a condition marked by sudden bilateral vision loss, photoreceptor disruption, and variable recovery.

Eight pediatric patients between the ages of 3 and 7 experienced severe, sudden-onset vision loss approximately two weeks after a febrile illness. Despite initial poor visual acuity, most showed significant central vision recovery over one year. Comprehensive retinal imaging revealed characteristic ellipsoid zone (EZ) and external limiting membrane (ELM) disruptions. Electroretinography (ERG) findings demonstrated extinguished cone and rod responses, even in cases where vision improved.

In the study, "Hyperacute Outer Retinal Dysfunction," published in JAMA Ophthalmology, researchers examined eight children (16 eyes) referred to pediatric retina services in China. Patients had no prior history of visual impairment and underwent thorough ophthalmic and systemic evaluations. Exclusion criteria included inherited retinal disease, uveitis, and white dot syndromes.

Best-corrected visual acuity (BCVA) was assessed at baseline and during follow-up. Multimodal imaging included color fundus photography, ultra-widefield imaging, optical coherence tomography (OCT), fluorescence angiography, fundus autofluorescence, and electroretinography. Genetic and serological testing was conducted to rule out inherited and autoimmune retinal diseases. Patients received varying immunosuppressive treatments, including corticosteroids, intravenous immunoglobulin and methotrexate.

Initial symptoms included severe bilateral vision loss, nyctalopia, visual field constriction, and dyschromatopsia. At presentation, the patient's mean visual acuity was below the ability to count fingers correctly. OCT imaging showed diffuse EZ and ELM loss, while early fundus findings were largely unremarkable.

By the fourth week, signs of macular recovery appeared. At one year, 88% (7 of 8 patients) achieved visual acuity of 20/40 or better, with 50% (4 of 8) reaching 20/25 or better. Macular EZ and ELM appeared intact in 75% and 88% of eyes, respectively, though extrafoveal regions remained affected. ERG continued to show extinguished rod and cone responses despite visual improvement.

Systemic evaluations were unremarkable. No infectious or autoimmune triggers were identified, although two patients tested positive for specific antiretinal antibodies (antiPKC γ and antiRi). Treatment with corticosteroids and IVIG was initiated in most patients, though a definitive therapeutic effect of treatment remained unclear from the study.

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