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Comment by Dr. Krishna Kumari Challa on January 19, 2025 at 11:57am

Neuroimaging reveals 94% of gray matter in brains of mothers undergoes changes during pregnancy

A study led by the UAB has analyzed the brains of women during pregnancy for the first time using neuroimaging techniques. The study included non-pregnant mothers, whose partners were pregnant, to distinguish biological effects from those caused by the experience of being a mother. The research shows that there is a reduction and partial recovery of almost 5% of gray matter in 94% of the total gray matter volume of the brain, especially in regions linked to social cognition.

The researchers have published the first longitudinal neuroimaging (Magnetic Resonance Imaging) study in a cohort of more than a hundred women seeking to become mothers for the first time.

In total, the researchers have analyzed the brain of 179 women to study the structural changes that occur during the second and third trimester of pregnancy and the first six months postpartum, using a scan taken before conception as a baseline. For the first time, this cohort includes a group of non-gestational mothers as a control group: women whose partners underwent pregnancy during the study. The inclusion of this group of women made it possible to determine that the trajectory of brain changes is mainly attributed to the biological process of pregnancy, rather than to the experience of becoming a mother.

The findings reveal a dynamic trajectory in the brain during pregnancy and postpartum, significantly linked to the steroid hormone fluctuations inherent to pregnancy, and to the psychological well-being of the mothers.

This work has revealed that, during the first pregnancy, gray matter volume in the brain is reduced by up to 4.9%, with a partial recovery during the postpartum period. These changes are observed in 94% of the brain, being particularly prominent in regions linked to social cognition.

The study also demonstrates, for the first time, that the evolution of these morphological changes in the brain is associated with fluctuations in two estrogens (estriol-3-sulfate and estrone-sulfate), hormones that increase exponentially during pregnancy and return to basal levels after delivery. Specifically, the researchers observed that a greater increase and subsequent decrease in estrogen levels is associated with a greater decrease and subsequent recovery of brain gray matter volume.

Finally, in analyzing the possible influence of brain changes on maternal behaviour, this study discovered that women with a higher percentage of grey  matter volume recovery during postpartum reported a greater bond with their infant at 6 months postpartum, and that maternal well-being is a key factor that positively enhances the association between brain changes and maternal-filial bonding.

This study, which comprehensively characterizes normative brain changes during pregnancy and postpartum, stands out for both its sample size and rigorous methodological control, including carefully selected groups that allowed the distinguishing of pregnancy-specific changes from those linked to the experience of motherhood.

The data obtained not only establishes a key reference for understanding the neurobiology of the maternal brain, but also serves as a basis for future studies analyzing other neuroimaging modalities and more diverse samples, including women with clinical conditions such as postpartum depression , allowing progress towards a more complete and applied understanding of the brain in this vital period.

Camila Servin-Barthet et al, Pregnancy entails a U-shaped trajectory in human brain structure linked to hormones and maternal attachment, Nature Communications (2025). DOI: 10.1038/s41467-025-55830-0

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Comment by Dr. Krishna Kumari Challa on January 18, 2025 at 9:29am

Brains of people with sickle cell disease appear older, study finds

Individuals with sickle cell disease—a chronic illness where misshapen, sticky blood cells clump together, reducing oxygen delivery to organs—are at a higher risk for stroke and resulting cognitive disability. But even in the absence of stroke, many such patients struggle with remembering, focusing, learning and problem solving, among other cognitive problems, with many facing challenges in school and in the workplace.

Now a multidisciplinary team of researchers and physicians at Washington University School of Medicine in St. Louis has published a study that helps explain how the illness might affect cognitive performance in sickle cell patients without a history of stroke.

The researchers found such participants had brains that appeared older than expected for their age. Individuals experiencing economic deprivation, who struggle to meet basic needs, even in the absence of sickle cell disease, had more-aged-appearing brains, the team also found.

The study was published January 17 in JAMA Network Open.

Brain age modelling and cognitive outcomes in young adults with and without sickle cell anemia., JAMA Network Open (2025). DOI: 10.1001/jamanetworkopen.2024.53669

Comment by Dr. Krishna Kumari Challa on January 18, 2025 at 9:24am

Study provides insight into how some species thrive in dark, oxygen-free environments

Most life on Earth relies on the sun's energy for survival, but what about organisms in the deep sea that live beyond the reach of its rays? A new study led by Woods Hole Oceanographic Institution (WHOI), published in The ISME Journal, sheds light on how a species of foraminifera, single-celled organisms found in almost all marine habitats, thrives in a dark, oxygen-free environment.

For this foraminifera species, the answer is chemoautotrophy, a metabolic process that utilizes inorganic energy sources, perhaps sulfide, to take up carbon, enabling it to survive in oxygen-free environments. Chemoautotrophy has been observed within Bacteria and Archaea, which are microbial organisms without a true nucleus. However, foraminifera are eukaryotes, meaning they have a well-defined nucleus, which houses an organism's genetic material.

 Fatma Gomaa et al, Array of metabolic pathways in a kleptoplastidic foraminiferan protist supports chemoautotrophy in dark, euxinic seafloor sediments, The ISME Journal (2024). DOI: 10.1093/ismejo/wrae248

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Comment by Dr. Krishna Kumari Challa on January 18, 2025 at 9:14am

A chain reaction: HIV vaccines can lead to antibodies against antibodies

Many vaccines work by introducing a protein to the body that resembles part of a virus. Ideally, the immune system will produce long-lasting antibodies recognizing that specific virus, thereby providing protection.

But scientists have now discovered that for some HIV vaccines, something else happens: after a few immunizations the immune system begins to produce antibodies against immune complexes already bound to the viral protein alone.

They don't yet know whether this chain reaction, described in Science Immunology, hurts or helps the immune system's ability to fight HIV, but say that understanding it better could lead to improvements in HIV vaccines. The research was published in the journal on January 17, 2025.

Understanding these responses could lead to smarter vaccine designs and immunotherapeutics. It's an exciting step forward in fine-tuning antibody and vaccine-based strategies against HIV and other diseases.

Sharidan Brown et al, Anti-Immune Complex Antibodies are Elicited During Repeated Immunization with HIV Env Immunogens, Science Immunology (2025). DOI: 10.1126/sciimmunol.adp5218. www.science.org/doi/10.1126/sciimmunol.adp5218

Comment by Dr. Krishna Kumari Challa on January 17, 2025 at 11:55am

Finding Clues to Oxygen Production on Early Earth

Possible link between Earth’s rotation rate and oxygenation

Earth's Rotation Is Slowing Down, And Could Explain Why We Have Oxygen

Ever since its formation around 4.5 billion years ago, Earth's rotation has been gradually slowing down, and its days have gotten progressively longer as a result.

While Earth's slowdown is not noticeable on human timescales, it's enough to work significant changes over eons. One of those changes is perhaps the most significant of all, at least to us: lengthening days are linked to the oxygenation of Earth's atmosphere, according to a study from 2021.

Specifically, the blue-green algae (or cyanobacteria) that emerged and proliferated about 2.4 billion years ago would have been able to produce more oxygen as a metabolic by-product because Earth's days grew longer.

There are two major components to this story that, at first glance, don't seem to have a lot to do with each other. The first is that Earth's spin is slowing down. The reason Earth's spin is slowing down is because the Moon exerts a gravitational pull on the planet, which causes a rotational deceleration since the Moon is gradually pulling away. We know, based on the fossil record, that days were just 18 hours long 1.4 billion years ago, and half an hour shorter than they are today 70 million years ago. Evidence suggests that we're gaining 1.8 milliseconds a century.

The second component is something known as the Great Oxidation Event – when cyanobacteria emerged in such great quantities that Earth's atmosphere experienced a sharp, significant rise in oxygen. Without this oxidation, scientists think life as we know it could not have emerged; so, although cyanobacteria may cop a bit of side-eye today, the fact is we probably wouldn't be here without them.

https://www.nature.com/articles/s41561-021-00784-3

Comment by Dr. Krishna Kumari Challa on January 17, 2025 at 10:03am

Wildfires ignite infection risks by weakening the body's immune defenses and spreading bugs in smoke

We know fire can harm directly, causing injuries and death.

But wildfires, or bushfires, can also have indirect consequences for human health. In particular, they can promote the incidence and spread of a range of infections.

Most people appreciate that fires can cause burns and smoke inhalation, both of which can be life-threatening in their own right. What's perhaps less well known is that both burns and smoke inhalation can cause acute and chronic changes in the immune system. This can leave those affected vulnerable to infections at the time of the injury, and for years to come.

Burns induce profound changes in the immune system. Some parts go into overdrive, becoming too reactive and leading to hyper-inflammation. In the immediate aftermath of serious burns, this can contribute to sepsis and organ failure.

Comment by Dr. Krishna Kumari Challa on January 17, 2025 at 9:36am

The result of the study changes our understanding of sunburn and the skin's defense mechanisms: that RNA damage triggers a faster and more effective response, protecting the skin from further damage.
The fact that the DNA does not control the skin's initial response to UV radiation, but that something else does and that it does so more effectively and more quickly, is quite the paradigm shift.
We need to understand the function of RNA damage, as it may in the long term change our entire approach to prevention and treatment of sunburn."

"Many inflammatory skin diseases are worsened by sun exposure. Thus, understanding how our skin responds at the cellular level to UV damage opens the door to innovative treatments for certain chronic skin conditions.

Now rewrite the text books!

Anna Constance Vind et al, The ribotoxic stress response drives acute inflammation, cell death, and epidermal thickening in UV-irradiated skin in vivo, Molecular Cell (2024). DOI: 10.1016/j.molcel.2024.10.044

Part 2

Comment by Dr. Krishna Kumari Challa on January 17, 2025 at 9:34am

Damage to RNA, not DNA, found to be main cause of acute sunburn

We have all been told to avoid direct sunlight between 12 noon and 3 p.m., seek out shade and put on sunscreen and a hat. Nevertheless, most of us have experienced sunburn at least once. The skin turns bright red, feels irritated and needs cooling.

You may also have been told that sunburn damages the DNA. But that is not the full truth, according to researchers responsible for a new study conducted . The findings are published in the journal Molecular Cell.

Sunburn damages the DNA, leading to cell death and inflammation. So the textbooks say. But in this study researchers were surprised to learn that this is a result of damage to the RNA, not the DNA that causes the acute effects of sunburn!

RNA is similar to DNA, but whereas DNA is long lived, RNA is a more transient molecule. A type of RNA, known as messenger RNA (mRNA), functions as the intermediate 'messenger' that carries information from DNA to make proteins—the basic building blocks of cellular components.

DNA damage is serious as the mutations will get passed down to progenies of the cells, RNA damage happens all the time and does not cause permanent mutations. Therefore, we used to think that the RNA is less important, as long as the DNA is intact. But in fact, damages to the RNA are the first to trigger a response to UV radiation.

The new study was conducted on mice as well as human skin cells, and the objective was to describe the impact of UV radiation on the skin and what causes these damages. The researchers found the same skin response to UV radiation exists in both mice and human cells.

mRNA damage triggers a response in ribosomes (protein complexes that "read" the mRNA to synthesize protein), orchestrated by a protein known as ZAK-alpha—the so-called ribotoxic stress response—the new study shows. The response can be described as a surveillance system within the cells, which registers the RNA damage, leading to inflammatory signaling and recruitment of immune cells, which then leads to inflammation of the skin.

Researchers  found that the first thing the cells respond to after being exposed to UV radiation is damage to the RNA, and that this is what triggers cell death and inflammation of the skin. In mice exposed to UV radiation they found responses such as inflammation and cell death, but when they removed the ZAK gene, these responses disappeared, which means that ZAK plays a key role in the skin's response to UV-induced damage.

So you could say that everything depends on this one response, which monitors all protein translations occurring. The cells respond to the RNA damage, realizing that something is wrong, and this is what leads to cell death.

Part 1

Comment by Dr. Krishna Kumari Challa on January 17, 2025 at 9:19am

India achieves 'historic' space docking mission

India docked two satellites in space Thursday, a key milestone for the country's dreams of a space station and a manned moon mission, the space agency said.

The satellites, weighing 220 kilograms (485 pounds) each, blasted off in December on a single rocket from India's Sriharikota launch site. Later they separated.

The two satellites were maneuvered back together on Thursday in a "precision" process resulting in a "successful spacecraft capture", the Indian Space Research Organisation (ISRO) said, calling it a "historic moment".

India became the fourth country to achieve the feat—dubbed as SpaDeX, or Space Docking Experiment—after Russia, the United States and China.

The aim of the mission was to "develop and demonstrate the technology needed for rendezvous, docking, and undocking of two small spacecraft", ISRO said.

ISRO said the technology is "essential" for India's moon mission.

Source: ISRO

Comment by Dr. Krishna Kumari Challa on January 16, 2025 at 12:04pm

Mosquitoes defy droughts by drinking blood, ensuring survival and disease spread

Mosquitoes are able to survive prolonged droughts by drinking blood, which helps to explain how their populations quickly rebound when it finally rains, biologists found. 

A study examined how two species of mosquito known for infecting people with diseases such as malaria were able to survive nearly three weeks without rain.

The findings could help explain why the incidence of infection from mosquito-borne illness does not always decline during droughts. While there may be fewer mosquitoes, those that survive bite more often.

And mosquitoes appear to be benefiting from climate change as winters get warmer by biting people more!

 Christopher J. Holmes et al, Multiple blood feeding bouts in mosquitoes allow for prolonged survival and are predicted to increase viral transmission during dry periods, iScience (2025). DOI: 10.1016/j.isci.2025.111760

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