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Comment by Dr. Krishna Kumari Challa on September 14, 2024 at 7:14am

Ingredient in hair dye led to a woman's vision loss

An ingredient in the hair dye a French woman used caused her to develop a vision-robbing retinopathy, researchers report.

When she switched to a dye without these ingredients, called aromatic amines, her vision troubles resolved, according to a team led by Dr. Nicolas Chirpaz, an ophthalmologist at Edouard Herriot Hospital, in Lyon.

Such cases could be rare, the researchers said, but spreading awareness of the danger "may allow prompt consideration to remove exposure to such hair dye" so eyes aren't permanently damaged, Chirpaz and colleagues said.

They published their case report Sept. 12 in the journal JAMA Ophthalmology.

As the French team noted, this isn't the first time hair dye has been linked to retinopathy: Three prior cases were reported in 2022 among "middle-aged women following exposure to hair dyes containing aromatic amines."

In the latest case, a 61-year-old woman with no prior history of vision trouble came to doctors with progressively blurry vision in both eyes "a few days after dyeing her hair with hair dye containing aromatic amines," Chirpaz' group said. The aromatic amine in the dye used in this case was para-phenylenediamine.

Upon examination, the woman was found to have multiple retinal detachments that resembled the damage that can occur in retinopathies that are tied to certain enzymes found in the eye, called MEK1 or MEK2.

The woman's eyes also displayed an unhealthy "thickening of the neurosensory retina," the French team found.

Tests were conducted to rule out a host of possible causes, including infections and even cancer. In the end, retinal damage caused by the ingredient in hair dye was "diagnosed based on the temporal association between symptoms and hair dye exposure," the team said.

The woman soon switched her brand of hair dye, and her vision returned to 20/20 within a month. "Four years later, the patient reported using aromatic amines–free hair dye and has not experienced any recurrence," the study authors said.

Part 1

Comment by Dr. Krishna Kumari Challa on September 14, 2024 at 7:09am

Swallowing triggers a release of serotonin, research reveals

Why do you eat and what makes you eat more?

Researchers have identified an important control circuit involved in the eating process. The study has revealed that fly larvae have special sensors, or receptors, in their esophagus that are triggered as soon as the animal swallows something. If the larva has swallowed food, they tell the brain to release serotonin. This messenger substance—which is often also referred to as the feel-good hormone—ensures that the larva continues to eat.

The researchers assume that humans also have a very similar control circuit. The results were published in the journal Current Biology.

 It's the good feeling you have after swallowing that is largely responsible for you continuing to eat.

Researchers  identified a sort of "stretch receptor" in the esophagus. It is wired to a group of six neurons in the larva's brain that are able to produce serotonin. This neuromodulator is also sometimes called the "feel-good hormone." It ensures, for example, that we feel rewarded for certain actions and are encouraged to continue doing them.

The serotonin neurons receive additional information about what the animal has just swallowed. They can detect whether it is food or not and also evaluate its quality.

This mechanism is of such fundamental importance that it probably also exists in humans. If it is defective, it could potentially cause eating disorders such as anorexia or binge eating. It may therefore be possible that the results of this basic research could also have implications for the treatment of such disorders.

Andreas Schoofs et al, Serotonergic modulation of swallowing in a complete fly vagus nerve connectome, Current Biology (2024). DOI: 10.1016/j.cub.2024.08.025

Comment by Dr. Krishna Kumari Challa on September 14, 2024 at 6:53am

Earth to have new mini-moon for two months

A pair of asteroid dynamics researchers  have found that a small asteroid will make one orbit around the Earth starting this month before departing back into other parts of the solar system.

In their paper published in the journal Research Notes of the AAS, the researchers describe how the Earth tends to capture asteroids on a regular basis and outline their calculations showing the path of 2024 PT₅ as it comes close to Earth.

Prior research has shown that many asteroids fall into partial or full elliptical paths around the Earth before eventually being flung away. Back in 2006, for example, a small asteroid circled the Earth for approximately a year—and another one did so for several years before leaving in 2020.
In this new effort, the researchers were looking at a small asteroid that was discovered last month as part of the Asteroid Terrestrial-Impact Last Alert System. Prior research had shown that the asteroid was not on a collision course with Earth, and the researchers suspected it might instead become bound by the planet's gravity for a while.

The researchers noted that the asteroid is small, only 10 meters across. By noting its current size, speed and path, the pair were able to calculate its path over the next few months. They found that it was going to come close enough to the Earth to become bound by its gravity, if only for a couple of months.

Their work shows that it will circle the Earth one time, taking 53 days, starting at the end of this month and then leaving near the middle of November.
The researchers  found that it likely came from the Arjuna asteroid belt, which is made up of many asteroids with orbits around the sun similar to Earth's. 

Carlos de la Fuente Marcos et al, A Two-month Mini-moon: 2024 PT₅ Captured by Earth from September to November, Research Notes of the AAS (2024). DOI: 10.3847/2515-5172/ad781f

Comment by Dr. Krishna Kumari Challa on September 14, 2024 at 6:47am

Potential cause of vascular disease

Researchers have identified a key driver of a blood vessel disorder known as fibromuscular dysplasia (FMD) which affects up to 5% of the adult population and can lead to high blood pressure, heart attack, or stroke.

In a study published September 13 in Nature Cardiovascular Research, the team said changes in the gene UBR4 played an important role as a key driver of FMD. They suggested the discovery could be an important step toward developing a therapeutic approach for the disorder.

Fibromuscular dysplasia involves abnormal cell growth in the walls of the arteries, including the carotid, renal, and coronary arteries. Though anyone can develop the condition, it has a distinct sexual bias, affecting women in about 90% of cases. Unlike other vascular diseases such as atherosclerosis, FMD is not caused by a build-up of plaque, and many people are unaware they have the disorder.

Among the serious medical conditions it can lead to—depending on which artery is affected—are aneurysm (bulging and weakening of the artery), dissection (tearing of the arterial wall), stroke, and heart attack. Restricted blood flow from FMD can also result in high blood pressure, pulsatile tinnitus (whooshing sound in the ears that occurs with each heart beat), and migraine headaches.

Researchers used skin biopsies from 83 women with FMD as well as from 71 healthy female controls to obtain and grow fibroblast cells, which then underwent gene sequencing to pinpoint the genetic differences between patients and the matched healthy controls.

Applying advanced statistical methods known as "systems biology" enabled the scientists to create the first-ever mouse models that recapitulated certain aspects of the disease in humans, and to uncover important insights into its causal pathways and disease drivers.

"These insights included the finding that changes in UBR4 levels—which cause significant changes in the expression levels of other genes in the FMD-associated supernetwork—collectively led to major changes in vascular cell function.

These alterations in turn led to a demonstrable widening of the arteries in mice, which is one of the features of FMD in humans.

By identifying a gene and its gene regulatory network that appear to account for a significant portion of FMD heritability, scientists think they have taken a major step toward a therapeutic solution.

 Integrative Gene Regulatory Network Analysis Discloses Key Driver Genes of Fibromuscular Dysplasia, Nature Cardiovascular Research (2024).

Comment by Dr. Krishna Kumari Challa on September 14, 2024 at 6:35am

The research also shows plants can precisely control and modify the shape and size of these patterns using multiple mechanisms, with possible implications for plant evolution. By fine-tuning these designs, plants may gain a competitive advantage in the contest to attract pollinators or maybe start attracting different species of insects.

Lucie Riglet et al, Hibiscus bullseyes reveal mechanisms controlling petal pattern proportions that influence plant-pollinator interactions, Science Advances (2024). DOI: 10.1126/sciadv.adp5574. www.science.org/doi/10.1126/sciadv.adp5574

Part 2

Comment by Dr. Krishna Kumari Challa on September 14, 2024 at 6:35am

Flowers use adjustable 'paint by numbers' petal designs to attract pollinators

Flowers like hibiscus use an invisible blueprint established very early in petal formation that dictates the size of their bullseyes—a crucial pre-pattern that can significantly impact their ability to attract pollinating bees.

The study also found that bees prefer larger bullseyes over smaller ones and fly 25% faster between artificial flower disks with larger bullseyes—potentially boosting efficiency for both bees and blossoms. The findings are published in Science Advances.

Patterns on the flowers of plants guide insects, like bees, to the center of the flower, where nectar and pollen await, enhancing the plant's chances of successful pollination. 

Finding out how these petal patterns form and how they have evolved into the vast diversity we see today, including spots, stripes, veins, and bullseyes is an interesting subject. 

: Researchers compared the relative success of the bullseye patterns in attracting pollinators using artificial flower discs that mimicked the three different bullseye dimensions. The bees not only preferred the medium and larger bullseyes over the small bullseye, they were also 25% quicker visiting these larger flower discs. Credit: Lucie Riglet

Using a small hibiscus plant as a model, researchers compared closely related plants with the same flower size but three differently sized bullseye patterns featuring a dark purple center surrounded by white—H. richardsonii (small bullseye covering 4% of the flower disk), H. trionum (medium bullseye covering 16%) and a transgenic line (mutation) of H. trionum (large bullseye covering 36%).

They found that a pre-pattern is set up on the petal surface very early in the flower's formation, long before the petal shows any visible color. The petal acts like a 'paint-by-numbers' canvas, where different regions are predetermined to develop specific colors and textures long before they start looking different from one another.

Part 1

Comment by Dr. Krishna Kumari Challa on September 13, 2024 at 10:11am

Social media became a storefront for deadly fake pills

Fentanyl overdoses have become a leading cause of death for minors in the last five years or so, even as overall drug use has dropped slightly. In a 2022 analysis of fentanyl-laced prescription pills, the DEA found that six out of 10 contained a potentially lethal dose of the drug.

And social media, where tainted, fake prescription drugs can be obtained with just a few clicks, is a big part of the problem. Experts, law enforcement and children's advocates say companies like Snap, TikTok, Telegram and Meta Platforms, which owns Instagram, are not doing enough to keep children safe.

The stories of these victims often play out similarly: The kids hear you can get pills on social media. A few taps later and then a package arrives. They retreat to the sanctity of their bedroom and take a pill. Fifteen minutes later, they're dead. No one even knows until the next morning.

https://medicalxpress.com/news/2024-09-dealers-paradise-social-medi...

Comment by Dr. Krishna Kumari Challa on September 13, 2024 at 10:04am

How the immune system fails as cancer arises

Cancer has been described as "a wound that does not heal," implying that the immune system is unable to wipe out invading tumor cells. A new discovery confirms that a key molecule can reprogram immune cells that normally protect against infection and cancer, turning them into bad guys that promote cancer growth.

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How genes shape personality traits: New links discovered

Your DNA has long been known to play a role in shaping your personality. Now, researchers at Yale School of Medicine (YSM) have taken another step in determining exactly how by identifying a number of new genetic sites associated with specific personality traits. They published their findings in Nature Human Behaviour.

Comment by Dr. Krishna Kumari Challa on September 13, 2024 at 9:49am

Dams built to prevent coastal flooding can worsen it

The common practice of building dams to prevent flooding can actually contribute to more intense coastal flood events, according to a new study.

The study, published in the Journal of Geophysical Research: Oceans, studied the effects of dams built in coastal estuaries, where rivers and ocean tides interact. Those massive infrastructure projects are surging in popularity globally, in part to help offset intensifying storms, salt intrusion and sea-level raise fueled by climate change.

By analyzing data and measurements from Charleston Harbor, South Carolina, dating back more than a century, researchers determined that coastal dams don't necessarily mitigate flooding. Dams can either increase or decrease flood risks, depending on the duration of a surge event and friction from the flow of water.

We usually think about storm surges becoming smaller as you go inland, but the shape of the basin can actually cause it to become larger.

Estuaries are typically shaped like a funnel, narrowing as they go inland. Introducing a dam shortens the estuary with an artificial wall that reflects storm surge waves moving inland. The narrowing channel shape also makes small reflections that change with the surge duration. Researchers  compared those storm-fueled waves to splashes in a bathtub, with certain wave frequencies causing water to slosh over the sides.

After using Charleston Harbor as a case study, researchers used computer modeling to gauge the flood response at 23 other estuaries in diverse geographic areas. Those encompassed both dammed and naturally occurring estuary systems, including Cook Inlet in Alaska.

The models confirmed that the basin shape and alterations that shorten it with a dam are the key component in determining how storm surges and tides move inland. At the right amplitude and duration, waves in dammed environments grow instead of diminishing.

The study also determined that areas far from coastal dams could still be directly influenced by human-created infrastructure.

Steven L. Dykstra et al, Reflection of Storm Surge and Tides in Convergent Estuaries With Dams, the Case of Charleston, USA, Journal of Geophysical Research: Oceans (2024). DOI: 10.1029/2023JC020498

Comment by Dr. Krishna Kumari Challa on September 13, 2024 at 9:42am

Geoscientists detect rapid uplift at a volcano in Tanzania

When a volcano is about to erupt, the surrounding land puffs up like a squeezed balloon. The technical term is "transient deformation," and  researchers have detected and tracked this short-lived movement for the first time using satellite observations of Ol Doinyo Lengai, an active Tanzanian volcano.

Their results appeared in a paper published earlier this summer in Geophysical Research Letters.

According to the study, increasing pressure inside a volcano's magma reservoir can cause the land to bulge. When the pressure decreases, the reservoir deflates again and the land falls back.

Researchers have been able to detect transient motion in volcanic activity, and this is a precursor for any kind of eruption.

This research could help  authorities have a better idea of what is happening with the volcano and take precautionary measures. 

Ntambila Daud et al, Detecting Transient Uplift at the Active Volcano Ol Doinyo Lengai in Tanzania With the TZVOLCANO Network, Geophysical Research Letters (2024). DOI: 10.1029/2023GL108097

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