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Comment by Dr. Krishna Kumari Challa on Friday

Tiny rotating hairs inside a microscopic cavity decide where your organs will grow
Organ asymmetry in humans originates during embryonic development, where rotating cilia in the embryonic node generate a directional fluid flow that influences left-right organ placement. Using an artificial node with magnetically controlled cilia and advanced simulations, it was demonstrated that both cilia-induced flow and morphogen transport together break left-right symmetry.

Heart to the left. Liver to the right. That's where you'll find these organs in a healthy human body, but surprisingly, in some people, the heart is on the right and the liver on the left. This normal or abnormal asymmetry can be traced back to your embryonic stage. In the early days of your development, a small fluid-filled cavity known as an embryonic node forms in your embryo. Inside, tiny micro-hairs known as cilia create a flow pattern that steers where organs grow in your body.

Researchers have revealed key details behind the process by building a world-first artificial embryonic node—using synthetic magnetically controlled cilia to generate a flow pattern—and then explore what happens in the node using advanced simulations. They published their findings on March 25 in the journal Science Advances.

It can be traced all the way back to your first period as an embryo. And it has to do with what happens in something called an embryonic node.

An embryonic node is a small cavity that contains a fluid (made up of water, proteins, hormones, and other substances). The top is closed off by a membrane, while the bottom layer is lined with a few hundred tiny micro-hairs called cilia. The whole node is just a few hundred micrometers across. "The cilia in the embryonic node rotate in the same direction, making a tilted conical motion. This generates an anticlockwise fluid flow inside the node, and it's this flow that is known to play a key role in the left-right symmetry.

Tanveer ul Islam et al, Artificial embryonic node elucidates the role of flow in left-right symmetry breaking in vertebrates, Science Advances (2026). DOI: 10.1126/sciadv.aec2328

Comment by Dr. Krishna Kumari Challa on Friday

Why cells respond 'incorrectly' in old age
Aging cells exhibit altered responses to external signals due to changes in chromatin structure within the nucleus. With age, chromatin becomes more open, leading to less accurate gene expression and increased activation of inappropriate genes. This impairs essential cellular processes and may contribute to age-related diseases, suggesting that targeting chromatin structure could support healthier aging.
Some of the signs of aging in human cells originate in the cell nucleus, because the packaged form of DNA changes with age. This has now been demonstrated by  researchers. It means that older cells can no longer react appropriately to external stimuli, and this can even lead to diseases. This insight could help scientists to curb such alterations and support better health in old age.

As we age, our cells age with us. Although they remain active, they become less flexible, stop dividing and sometimes respond incorrectly to signals. The reason for this lies in the cell nuclei, specifically in the chromatin—the packaged form of our DNA.

This is the finding of a study by researchers  who analyzed samples of skin cells taken from people of different ages in the laboratory. They have published their findings in the journal PNAS.

Using a microscope and molecular biological methods, the scientists examined how various skin cells reacted to a specific chemical messenger when mechanical tension was applied. They compared skin cells from ten-year-old children with those from 75-year-olds.

 the response of older people's cells to the same stimuli was different and significantly weaker. The scientists were able to attribute this to a specific cause: the chromatin in the cell nucleus changes with age. As a result, certain genes—sections of DNA that belong together—can no longer be read as accurately.

This process, known as gene expression, is important in order to produce the proteins required by the organism, because the genes store the instructions for building those proteins. However, if the shape of the chromatin changes with age, other processes may be triggered instead, which can harm the organism.

Shivashankar, G. V., Chromatin accessibility regulates age-dependent nuclear mechanotransduction, Proceedings of the National Academy of Sciences (2026). DOI: 10.1073/pnas.2522217123. doi.org/10.1073/pnas.2522217123

Comment by Dr. Krishna Kumari Challa on Thursday

The cloning limit does exist

After 20 years and more than 30,000 cloning attempts, researchers have found the limit on the number of times that a single mouse can be serially re-cloned — their attempts failed after 58 generations. The cloned mice looked normal and lived as long as normal mice, but accumulated mutations at an unusually high rate, which could be why attempts to clone them were eventually unsuccessful, the team says. The findings suggest that asexual reproduction is ultimately unsustainable for mice, and potentially for other mammals, too.

https://www.nature.com/articles/s41467-026-69765-7?utm_source=Live+...

Comment by Dr. Krishna Kumari Challa on Thursday

Walking pace may outperform blood pressure and cholesterol in predicting mortality risk, study suggests
Analysis of over 400,000 UK adults indicates that walking pace is a stronger predictor of mortality risk than blood pressure or cholesterol, particularly in individuals with chronic health conditions. Incorporating simple physical measures such as walking pace, handgrip strength, and resting heart rate enhances mortality risk prediction beyond traditional clinical factors.

The Utility of Measures of Physical Behavior, Function, and Fitness as Predictors of Mortality, Mayo Clinic Proceedings (2026). DOI: 10.1016/j.mayocpiqio.2026.100710

Comment by Dr. Krishna Kumari Challa on Thursday

The study reported that:

Out of nearly 3 million pregnancies, approximately 1% (n = 28,641) were affected by placental abruption.
During a 28-year follow-up period, children born to mothers who had a placental abruption during the pregnancy were 4.6 times more likely to die from cardiovascular disease than children born to mothers who experienced a normal placental separation from the uterus after delivery.
Children born to mothers who had a placental abruption faced nearly three times higher risk of being hospitalized for heart-related complications during the next 28 years. These conditions included heart failure, ischemic heart disease, heart attack, blocked arteries, and general cardiovascular disease.
The children's risk of stroke hospitalization was 2.4 times higher than for children whose mothers did not have a placental abruption.
These heart disease and stroke risks associated with abruption were even higher among children younger than 1 year old.
The association between placental abruption and increased cardiovascular risk remained similar after conducting an additional analysis contrasting cardiovascular disease risks between biological siblings (each mother served as their own control), suggesting that genetic and environmental factors did not explain this relationship.

Placental abruption is a sudden and often catastrophic event that cannot be prevented and comes with no warning. Older women or those expecting more than one baby, such as twins or triplets, have an increased risk of developing this condition.
Avoiding smoking, drinking alcohol, and using illegal drugs (particularly, cocaine) and maintaining good blood pressure control are also important, as they are linked to placental abruption.

Cardiovascular Disease in Singleton Offspring Born of Pregnancies Complicated by Placental Abruption: A Population-Based Retrospective Cohort Study, DOI: 10.1161/JAHA.125.045199

Part 2

Comment by Dr. Krishna Kumari Challa on Thursday

Premature placental separation may increase child's risk of heart disease by age 28

Children born after placental abruption face a 4.6-fold higher risk of early cardiovascular disease or death from cardiovascular disease by age 28 compared to those without this complication. Risks of heart-related hospitalization and stroke are also significantly elevated. The association persists even when accounting for genetic and environmental factors within families.
The risk of developing early cardiovascular disease or dying from cardiovascular disease by the age of 28 was about 4.6 times higher among people born to mothers who had a placental abruption during their pregnancy. This finding was compared to people whose birth did not have this complication, according to new research published in the Journal of the American Heart Association.
Placental abruption occurs when the placenta separates from the uterus before birth rather than after delivery, and this can lead to severe hemorrhaging or other serious complications for the mother and baby. According to the American Heart Association's 2026 Heart Disease and Stroke Statistics, most studies have reported an incidence of 0.5% to 1% for placental abruption in the general population.
The study suggests that placental abruption needs to be taken as a very serious complication for the mother and also potentially affecting the baby's cardiovascular health later in life.
Most treatments after a placental abruption focus on following the mother after a pregnancy complication. This study shows it is important that their children are also monitored to identify potential complications due to their increased risk of cardiovascular disease.

Comment by Dr. Krishna Kumari Challa on Thursday

Dengue fever is a growing problem: Why it's so hard to beat with vaccines

Dengue fever, caused by four related viral serotypes, is expanding globally due to climate and urbanization. Vaccine development is challenging because immunity to one serotype can worsen infection with another via antibody-dependent enhancement. Effective vaccines must induce balanced, strongly neutralizing responses to all serotypes. Vaccine performance varies by prior infection, age, and transmission intensity, requiring tailored strategies and ongoing safety monitoring.

https://theconversation.com/dengue-fever-is-a-growing-problem-why-i...

Comment by Dr. Krishna Kumari Challa on Thursday

How inflammation may prime the gut for cancer
Chronic gut inflammation can leave lasting epigenetic changes, or "molecular scars," in intestinal cells, making tissues more susceptible to cancer if a cancer-promoting mutation occurs later. These epigenetic alterations persist after inflammation subsides, are inherited by daughter cells, and may accelerate tumor growth, highlighting potential biomarkers and intervention targets for colorectal cancer risk.

Chronic inflammation can raise a person's risk of cancer, and a new study reveals key details about how that might happen in the gut and points to better ways to identify and reduce risk.
revealed in mice that after colitis (chronic intestinal inflammation), seemingly healed gut tissues may retain the memory of earlier inflammation through molecular "scars" that make it easier for cancer to take hold later on. These memories are encoded as changes in the epigenome that are handed down from cell to cell through many generations of cell division, with long-lasting effects on gene activity that can later drive tumor growth.
The work, appearing in Nature, suggests a two-hit process over time in which alterations in the genome—an epigenetic change and a cancer mutation—can accelerate tumor growth. It also points to ways to potentially identify and possibly intervene on these cancer-promoting factors with new biomarkers and therapeutics.

Surya Nagaraja et al, Epigenetic memory of colitis in stem cells promotes tumour growth, Nature (2026). DOI: 10.1038/s41586-026-10258-4. www.nature.com/articles/s41586-026-10258-4

Comment by Dr. Krishna Kumari Challa on Thursday

What is particularly noteworthy is the idea that it is not only epigenetic processes that influence an individual's behavior and, consequently, their environment, but that, conversely, the environment altered by individual decisions can also give rise to new epigenetic patterns.

For example, individuals may seek out a new living environment or alter their surroundings by building a nest, which in turn affects the epigenome—the totality of all epigenetic marks. Even without direct inheritance via the germline, the epigenome can thus be altered in offspring.

This has far-reaching consequences: such processes could buffer natural selection and thereby generate and maintain epigenetic diversity within populations.
For understanding ecological and evolutionary processes, this represents a shift in perspective. Rather than examining genetic or phenotypic differences in isolation, researchers should analyze genetic, epigenetic and observable traits of the same individuals together.

This concept helps explain how environmental change is linked to individualization. In times of climate change and biodiversity loss, it provides an important foundation for better assessing the adaptive capacity and resilience of natural populations.

Denis Meuthen et al, Exploring the interplay of epigenetics and individualization, Trends in Ecology & Evolution (2026). DOI: 10.1016/j.tree.2025.12.010

Part 2

Comment by Dr. Krishna Kumari Challa on Thursday

Why no individual is like another when epigenetics come into play
Epigenetic modifications—chemical changes to DNA that do not alter its sequence—regulate gene expression and contribute to individual behavioural differences among animals. These modifications can result from both environmental influences and intrinsic factors, creating a dynamic interplay where behaviour and environment reciprocally shape the epigenome. This process enhances individual ecological niches and maintains diversity within populations, influencing adaptation and evolution.

Why do animals behave differently, and what are the consequences of this? A research team now provides a new explanation: epigenetic processes—chemical markings on DNA—may play a key role. The study, published in the journal Trends in Ecology & Evolution, links individuality, environmental adaptation, genetics, ecology, and evolution in a novel way.
The researchers propose that individuality and epigenetic variation influence each other. This bidirectionality—this mutual interaction—helps us to better understand ecological and evolutionary processes, they say.
At the center of the study is epigenetics. This refers to chemical modifications of DNA in which small molecules attach to the genetic material. These modifications do not alter the genetic sequence itself, but they regulate how frequently a gene is translated into proteins. Proteins, in turn, shape the observable traits and characteristics of an organism.

Thus, the same genetic blueprint—the same genotype—can give rise to different appearances, known as phenotypes. The researchers propose that epigenetic mechanisms contribute to how animals develop their individual ecological niche.

An individual niche is the range of environmental conditions under which a specific individual with a given set of traits could possibly live and reproduce. It is a subset of the species' niche that arises from the interaction of the individual with its environment.
The researchers distinguish between epigenetic changes triggered by environmental factors and those that arise independently, such as genetically determined or spontaneously occurring modifications. All forms play different roles in shaping individual differences.
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