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Comment by Dr. Krishna Kumari Challa yesterday

Adverse outcomes increased with long-term inhaled corticosteroids in COPD

For patients with chronic obstructive pulmonary disorder (COPD), long-term inhaled corticosteroid (ICS) treatment is associated with increased rates of adverse composite and specific individual outcomes, according to a study published in the March/April issue of the Annals of Family Medicine.

examined electronic health record data for individuals older than 45 years with COPD to assess long-term ICS risks. The prevalent cohort had a COPD diagnosis any time during the observation period (318,385 individuals), and the inception cohort had a COPD diagnosis after entry into the database (209,062 individuals).

A composite outcome of any new diagnosis of type 2 diabetes, cataracts, pneumonia, osteoporosis, or nontraumatic fracture and recurrent event outcomes of repeated pneumonia or nontraumatic fracture were compared for long- versus short-term ICS exposure (>24 months versus <4 months).

The researchers found that the composite dichotomous outcome was significantly greater for long- versus short-term ICS use for both the prevalent and inception cohorts (hazard ratios, 2.65 and 2.60, respectively). The absolute risk difference of the composite outcome was 20.26% for the inception cohort, with a number needed to harm of five.

For recurrent pneumonia and recurrent fracture, the hazard ratios were significantly increased in the prevalent and inception cohorts (hazard ratios, 2.88 and 2.85 for pneumonia, respectively; 1.77 and 1.57 for fracture, respectively).

"The clinical use of and indications for ICS therapy in COPD should be carefully considered for each individual before initiation of long-term ICS therapy," the authors write.

Wilson D. Pace et al, Adverse Outcomes Associated With Inhaled Corticosteroid Use in Individuals With Chronic Obstructive Pulmonary Disease, The Annals of Family Medicine (2025). DOI: 10.1370/afm.240030

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Comment by Dr. Krishna Kumari Challa yesterday

Measles outbreak leads to dangerous vitamin A toxicity

As a measles outbreak spreads across the U.S., doctors are now seeing a new and unexpected danger: children getting sick from taking too much vitamin A.

At Covenant Children's Hospital in Lubbock, Texas, several unvaccinated children showed signs of liver problems after taking large amounts of vitamin A, according to Dr. Lara Johnson, the hospital's chief medical officer.

U.S. Department of Health and Human Services Secretary Robert F. Kennedy Jr. has promoted vitamin A during the outbreak, even suggesting it might help prevent measles. But doctors say this isn't true.

If people have the mistaken impression that you have an either-or choice of MMR vaccine or vitamin A, you're going to get a lot of kids unnecessarily infected with measles. That's a problem, especially during an epidemic.

And second, you have this unregulated medicine in terms of doses being given and potential toxicities, say the doctors.

The measles, mumps and rubella (MMR) vaccine is the only proven way to prevent measles. It is 97% effective after two doses. 

Vitamin A can be helpful as a supplement for people with measles when given the right dose by a doctor. But taking too much, especially without medical supervision, can be dangerous.

Vitamin A is fat-soluble and can build up in the body. This can lead to dry skin, blurry vision, bone problems and liver damage. In pregnant women, it can even cause birth defects.

If kids are well nourished,  they don't need extra vitamin A.

Recovery for patients with acute toxicity can be rapid when the vitamin is discontinued. Sadly, some of the more serious problems with vitamin A toxicity are not always reversible.

The Council for Responsible Nutrition (CRN), a group representing supplement makers, also warned parents not to give their children high doses of vitamin A.

"While vitamin A plays an important role in supporting overall immune function, research hasn't established its effectiveness in preventing measles infection. CRN is concerned about reports of high-dose vitamin A being used inappropriately, especially in children," it said in a statement.

Doctors say some parents may be following questionable advice from social media or health influencers.

Source: News agencies

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Comment by Dr. Krishna Kumari Challa yesterday

They found that population, environment, and language all significantly contribute to the variation in hearing across human groups, but it wasn't clear whether this was due to the whole body being affected by the environment or due to long-term adaptations to varying soundscapes, noise levels, or exposure to pollution.

The researchers suggest that people living in forests could have higher sensitivity because they've adapted to soundscapes with lots of non-human sounds, where vigilance is essential for survival. Or it could be due to being exposed to lower levels of pollution.

People living at higher altitudes may have reduced sensitivity due to a number of reasons, including the impact of lower atmospheric pressure on measurements, potential sound reduction in high altitude environments, or physiological adaptations to lower oxygen levels.

The team also found a difference between urban and rural populations, with those living in cities having a shift towards higher frequencies, possibly due to filtering out low-frequency traffic noise.

Patricia Balaresque et al, Sex and environment shape cochlear sensitivity in human populations worldwide, Scientific Reports (2025). DOI: 10.1038/s41598-025-92763-6

Part 2

Comment by Dr. Krishna Kumari Challa yesterday

Women can hear better than men: Researchers find amplitude more influenced by sex than age

Scientists have found that sex is the leading factor explaining differences in hearing sensitivity, with women having significantly more sensitive hearing than men.

Hearing problems are on the rise worldwide, and while hearing sensitivity is well known to decrease with age, little research has been done on the other biological and environmental factors that influence them, such as sex, ear side, language, ethnicity, and local environment.

So researchers conducted hearing tests for 450 individuals across 13 global populations—Equador, England, Gabon, South Africa, and Uzbekistan. These populations were selected to capture a wide range of ecological and cultural contexts, including underrepresented rural and non-European groups.

They investigated the sensitivity of the cochlea in the ear, looking at how it transmitted brain signals in response to different amplitudes and frequencies of sound by measuring so-called Transient-Evoked Otoacoustic Emissions (TEOAE).

It's already well known that people generally have better hearing in their right ear, compared with their left, and that hearing usually declines with age. However, the researchers were surprised by their results on the effects of sex and the environment.

Their findings, published in the journal Scientific Reports, show that hearing amplitude is more influenced by sex than age, with women showing an average of two decibels more sensitive hearing than men across all the populations studied.

The second most significant influence was the environment, which not only affected the response to volume but also the range of frequencies of sound perceived. People living in forest areas had the highest hearing sensitivity and those living at high altitudes had the lowest.

Part 1

Comment by Dr. Krishna Kumari Challa yesterday

The phenomenon that organisms survive in dormancy over very long periods of time and can therefore potentially recolonize habitats under suitable conditions is also known from other studies—for example for plant seeds or small crustaceans, some of which remain viable for several centuries, even millennia.

However, the successful resurrection of a dormant stage after such a long time, as in the case of S. marinoi, has rarely been documented. At around 7000 years old, the tiny cells of this diatom are among the oldest organisms to have been successfully revived from an intact dormant stage. From aquatic sediments, no older such cases are known to date.

Sarah Bolius et al, Resurrection of a diatom after 7000 years from anoxic Baltic Sea sediment, The ISME Journal (2025). DOI: 10.1093/ismejo/wrae252

Part 3

Comment by Dr. Krishna Kumari Challa yesterday

The researchers examined sediment cores taken from 240 meters water depth in the Eastern Gotland Deep during an expedition with the research vessel Elisabeth Mann Borgese in 2021.

In favorable nutrient and light conditions, viable algae could be awakened from dormancy from nine sediment samples and individual strains were isolated. The samples were taken from different sediment layers that represent a time span of around 7,000 years and thus the main climate phases of the Baltic Sea.
The diatom species Skeletonema marinoi was the only phytoplankton species that was revived from all samples. It is very common in the Baltic Sea and typically occurs during the spring bloom. The oldest sample with viable cells of this species was dated to an age of 6,871 ± 140 years.

"It is remarkable that the resurrected algae have not only survived 'just so,' but apparently have not lost any of their 'fitness,' i. e. their biological performance ability. They grow, divide and photosynthesize like their modern descendants.
The measurement of photosynthetic performance also showed that even the oldest algae isolates can still actively produce oxygen—with average values of 184 micromoles of oxygen per milligram of chlorophyll per hour. These are also values that are comparable to those of current representatives of this species.
The researchers also analyzed the genetic profiles of the resurrected algae using microsatellite analysis—a method in which certain short DNA segments are compared. The result: The samples from sediment layers of different ages formed distinctive genetic groups.

Firstly, this ruled out the possibility that cross contamination could have occurred during the cultivation of the strains from sediment layers of different ages. Secondly, this proves that successive populations of S. marinoi in the Baltic Sea have changed genetically over the millennia.
Part 2

Comment by Dr. Krishna Kumari Challa yesterday

After 7,000 years without light and oxygen in Baltic Sea mud, researchers bring prehistoric algae back to life

A research team was able to revive dormant stages of algae that sank to the bottom of the Baltic Sea almost 7,000 years ago. Despite thousands of years of inactivity in the sediment without light and oxygen, the investigated diatom species regained full viability.

The study, published in The ISME Journal, was carried out as part of a collaborative research project PHYTOARK, which aims at a better understanding of the Baltic Sea's future by means of paleoecological investigations of the Baltic Sea's past.

Many organisms, from bacteria to mammals, can go into a kind of "sleep mode," known as dormancy, in order to survive periods of unfavorable environmental conditions.

They switch to a state of reduced metabolic activity and often form special dormancy stages with robust protective structures and internally stored energy reserves. This also applies to phytoplankton, microscopically small plants that live in the water and photosynthesize. Their dormant stages sink to the bottom of water bodies, where they are covered by sediment over time and preserved under anoxic conditions.

Such deposits are like a time capsule containing valuable information about past ecosystems and the inhabiting biological communities, their population development and genetic changes.

In this new study,  researchers analyzed specifically for viable phytoplankton dormant cells from the past. 

This approach bears the rather unusual name of 'resurrection ecology': Dormant stages that can be clearly assigned to specific periods of Baltic Sea history due to the clear stratification of the Baltic Sea sediment are to be brought back to life under favorable conditions, then they are genetically and physiologically characterized and compared with present-day phytoplankton population.

By analyzing other sediment components, so-called proxies, it will also be possible to draw conclusions about past salinity, oxygen and temperature conditions.

By combining all this information, they aim to better understand how and why Baltic Sea phytoplankton has adapted genetically and functionally to environmental changes.

Part 1

Comment by Dr. Krishna Kumari Challa yesterday

Following injury in organoids, stem-like cells migrated into the damaged area and produced new retinal cells. Gene activity during the repair process matched patterns observed during natural fetal development.
In a mouse model of inherited retinal degeneration, transplanted cells remained viable for up to 24 weeks. Donor cells integrated into the host retina, developed into mature retinal types, and formed connections with neighboring cells. Treated animals exhibited improved retinal structure and stronger visual responses compared to controls.
Human retinal stem-like cells demonstrated the capacity to regenerate tissue and restore visual function across both fetal tissue and retinal organoid models. In both injury models and transplant experiments, the cells demonstrated the ability to restore retinal structure and contribute to visual function.
Post-transplantation, the cells remained viable for at least 24 weeks, differentiated into photoreceptors, ganglion cells, and bipolar cells, and formed functional synapses with host tissue. Treated mice demonstrated improved retinal morphology and performance in visual function assays across multiple time points. No intraocular tumors were observed following transplantation.

Compared to previously studied retinal progenitor cells, this population showed broader differentiation capacity and longer-term viability. Transplanted cells contributed to retinal structure and restored visual function in mice, without adverse effects.

Results suggest that retinal organoids may serve as a source of human stem-like cells for future research and therapeutic development. Further studies will be needed to assess safety, immune compatibility, and effectiveness in models that more closely resemble human disease.

Hui Liu et al, Identification and characterization of human retinal stem cells capable of retinal regeneration, Science Translational Medicine (2025). DOI: 10.1126/scitranslmed.adp6864

Part 2

Comment by Dr. Krishna Kumari Challa yesterday

Human retinal stem-like cells with potential to repair vision loss discovered

Researchers  have identified a population of human neural retinal stem-like cells able to regenerate retinal tissue and support visual recovery.

Vision loss caused by retinal degeneration affects millions worldwide. Conditions such as retinitis pigmentosa and age-related macular degeneration involve the irreversible loss of light-sensitive neural cells in the retina. While current treatments may slow progression, they do not replace damaged tissue.

For decades, scientists have explored whether stem cells could be used to regenerate the retina, but the existence of true retinal stem cells in humans has remained uncertain. In fish and amphibians, the outer edge of the retina houses stem cells that regenerate tissue continuously. Whether a comparable system exists in the human eye has been debated for more than two decades.

In the study, "Identification and characterization of human retinal stem cells capable of retinal regeneration," published in Science Translational Medicine, researchers used single-cell and spatial transcriptomic methods to investigate the presence and identity of retinal stem-like cells in humans.

Researchers examined human fetal retinal tissue from four donors at 21 weeks of gestation, using spatial transcriptomics and single-nucleus sequencing to identify and localize cell types in the retina.

Researchers analyzed gene expression and chromatin accessibility to detect populations with stem cell–like properties. Additional samples from donors between 16 and 22 weeks of gestation were used to confirm the location of these cells in the peripheral retina.

A distinct population of neural retinal stem-like cells was identified in the peripheral retina of human fetal tissue. Located in the ciliary marginal zone, these cells showed molecular features consistent with self-renewal and the ability to differentiate into all major retinal cell types. Similar cells appeared in the same anatomical region of retinal organoids, with overlapping gene expression profiles.

Part 1

Comment by Dr. Krishna Kumari Challa on Friday

An Easy Way to Remove Microplastics From Your Drinking Water

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