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Comment by Dr. Krishna Kumari Challa on November 26, 2024 at 7:16am

Scientists create a 'minimal cell membrane' with just two lipids

Lipids, or fats, are essential to life. They form the membranes around cells, protecting them from the outside. In nature, there is an enormous diversity of lipids, with each organism having its own unique combination. But what are the minimum lipid requirements for a cell to survive?

A research team   showed that cells can function with just two lipids. They created a cell with a minimal, adaptable membrane, offering a unique platform to study how lipid complexity evolved and how it can be engineered for synthetic life. Their findings are published in Nature Communications.

Membranes are like bubbles that encapsulate cells and separate them from their surroundings. Membranes also serve as platforms where molecules interact, coordinating processes essential to life.

"There is an enormous diversity of lipids in nature, and almost every organism has its own set of lipids, known as lipidome. Human cells, for example, employ hundreds of different types of lipids. Yet, these different mixtures of lipids, all provide solutions to the same key evolutionary challenges: creating a stable barrier and organizing biomolecules in space and time.

For their study, the group started with mycoplasma mycoides, a naturally simple pathogenic bacterium. Unlike most cells, mycoplasma cannot make its own lipids and must instead use those provided by its host. By systematically supplementing cells with different lipid combinations, the researchers narrowed down the essential combination needed for survival and division.

They found that the cells can survive on a "diet" of just two lipids: cholesterol and another so-called bilayer-forming lipid, phosphatidylcholine.

These two lipids are not necessarily the only ones that could support life but having both a bilayer-forming lipid, which provides the basic structure for the cell membrane, and a non-bilayer-forming lipid, such as cholesterol, which adds stability, seems to be a fundamental requirement.

The team observed the cells with a minimal lipid diet under an electron microscope and saw dramatic effects on cell shape and size. Some cells grew up to ten times their usual size, while others formed unusual shapes and deformations.

The researchers observed that  about half of the cells with only two lipids appeared completely normal. They were round and divided well. Despite the drastic reduction in lipid complexity, they continued to function surprisingly well.

Reverse engineering the complexity of life

Having identified the minimal lipid diet, the researchers applied it to a "minimal cell" called JVCI-Syn3A, which was engineered at the J. Craig Venter Institute to contain only the genes essential for survival. Now, with both a minimal genome and lipidome, this cell provides a powerful new tool for synthetic biology.

This minimal cell system provides a unique platform to study how lipids support life. Using the principles of bottom-up synthetic biology, researchers can now reintroduce different parts of the lipidome in a directed way and explore the corresponding changes in cell function.

This knowledge could one day help us design synthetic cells with bespoke membranes for special applications in biotechnology and medicine.

Isaac Justice et al, A tuneable minimal cell membrane reveals that two lipid species suffice for life, Nature Communications (2024). DOI: 10.1038/s41467-024-53975-y

Comment by Dr. Krishna Kumari Challa on November 26, 2024 at 6:47am

UTIs are extraordinarily common but kidney infections are not—now we know know why

Infections in the lower urinary tract rarely migrate to the kidneys, but the precise mechanism that the human body employs to keep the twin organs disease-free has remained a medical mystery—until now.

A multidisciplinary team solved the conundrum in an elegant series of experiments. Researchers found that highly specialized biological structures called neutrophil extracellular traps—NETs—are pivotal in protecting the kidneys from infection.

NETs are sticky webs of wispy strands that quite literally serve as traps. They ensnare bacteria that attempt to migrate northward to the kidneys from the lower urinary tract. NETs add to an array of antimicrobial activities mounted by the body to beat back infection.

Writing in Science Translational Medicine, the researchers presented compelling evidence that sticky mesh-like immune NETs serve as a crucial antibacterial defense against infection. The team's study not only revealed the presence of NETs in the urinary tract but also answered a longstanding question in UTI research: What spares the kidneys from pathogens?

"These findings highlight the role of NETosis in preventing ascending infections in the urinary tract.

NETosis refers to the formation of NETs, which prevent any of the various species of bacteria—E. coli, Enterococcal faecalis, Proteus mirabilis, among others—from migrating upward from the bladder to the kidneys. The study focused on E. coli, the most common bacterial cause of UTIs.

The process of NETosis is another wonder of human biology. It reveals how the body, and more specifically, the immune system, creates structures to ensnare pathogens. The key entity in NETosis is the neutrophil, an immune cell, which is signaled to undergo a unique form of cell death. As it succumbs, the neutrophil releases its DNA, histones, and granule proteins, leaving behind a mesh-like structure, a net. E. coli and other bacteria become entrapped just as insects are snared by a spider's web. The process of NETosis isn't rare because NETs are found in the urine of healthy people, the researchers confirmed.

Andrew P. Stewart et al, Neutrophil extracellular traps protect the kidney from ascending infection and are required for a positive leukocyte dipstick test, Science Translational Medicine (2024). DOI: 10.1126/scitranslmed.adh5090

Comment by Dr. Krishna Kumari Challa on November 25, 2024 at 9:17am

How humans evolved to be 'energetically unique'

Humans, it turns out, possess much higher metabolic rates than other mammals, including our close relatives, apes and chimpanzees, finds a Harvard study. Having both high resting and active metabolism, researchers say, enabled our hunter-gatherer ancestors to get all the food they needed while also growing bigger brains, living longer, and increasing their rates of reproduction.

Humans are off-the-charts different from any creature that we know of so far in terms of how we use energy.

The paper, published in Proceedings of the National Academy of Sciences, challenges a previous consensus that human and non-human primates' metabolic rates are either the same or lower than would be expected for their body size.

Using a new comparison method that they say better corrects for body size, environmental temperature, and body fat, the researchers found that humans, unlike most mammals including other primates, have evolved to escape a tradeoff between resting and active metabolic rates.

Animals take in calories through food and, like a bank account, spend them on expenses mostly divided between two broad metabolic categories: resting and physical activity.

In other primates, there is a distinct tradeoff between resting and active metabolic rates, which helps explain why chimpanzees, with their large brains, costly reproductive strategies, and lifespans, and thus high resting metabolisms, are "couch potatoes" who spend much of their day eating.

Generally, the energy animals spend on metabolism ends up as heat, which is hard to dissipate in warm environments. Because of this tradeoff, animals such as chimpanzees who spend a great deal of energy on their resting metabolism and also inhabit warm, tropical environments, have to have low activity levels.

"Humans have increased not only our resting metabolisms beyond what even chimpanzees and monkeys have, but—thanks to our unique ability to dump heat by sweating—we've also been able to increase our physical activity levels without lowering our resting metabolic rates.

The result is that we are an energetically unique species.

The team's analysis shows that monkeys and apes evolved to invest about 30 to 50% more calories in their resting metabolic rates than other mammals of the same size, and that humans have taken this to a further extreme, investing 60% more calories than similar-sized mammals.

Andrew K. Yegian et al, Metabolic scaling, energy allocation tradeoffs, and the evolution of humans' unique metabolism, Proceedings of the National Academy of Sciences (2024). DOI: 10.1073/pnas.2409674121

Comment by Dr. Krishna Kumari Challa on November 25, 2024 at 9:09am

Oldest known alphabet unearthed in ancient Syrian city

What appears to be evidence of the oldest alphabetic writing in human history is etched onto finger-length, clay cylinders excavated from a tomb in Syria by a team of Johns Hopkins University researchers.

The writing, which is dated to around 2400 BCE, precedes other known alphabetic scripts by roughly 500 years, upending what archaeologists know about where alphabets came from, how they are shared across societies, and what that could mean for early urban civilizations.

At Umm-el Marra, the archaeologists uncovered tombs dating back to the Early Bronze Age. One of the best-preserved tombs contained six skeletons, gold and silver jewelry, cookware, a spearhead, and intact pottery vessels. Next to the pottery, the researchers found four lightly baked clay cylinders with what seemed to be alphabetic writing on them.

Maybe they detail the contents of a vessel, or maybe where the vessel came from, or who it belonged to. Without a means to translate the writing, the researchers can only speculate.

Using carbon-14 dating techniques, researchers confirmed the ages of the tombs, the artifacts, and the writing.

The results were presented  at the American Society of Overseas Research's Annual Meeting on Nov 21st.

Comment by Dr. Krishna Kumari Challa on November 25, 2024 at 8:53am

A Rare, Fatal Skin Disease Has Been Cured in Patients For The First Time
A rare and potentially fatal skin infection with nightmarish outcomes may soon have a cure.

The infection starts as a seemingly harmless rash, and before a person knows it, more than 30 percent of the skin on their body begins to blister and peel off in sheets, usually starting with the face and chest before progressing to the mouth, eyes, and genitals.
Infections, organ failure, and pneumonia can soon follow. In a third of all cases, the condition proves fatal. For those who survive, recovery can take months and usually requires similar treatment to burn victims.

The debilitating infection is an immune response to medication, called toxic epidermal necrolysis (TEN), and while it is thankfully very rare, impacting a million or two people worldwide every year, its onset is highly unpredictable.

TEN is linked with more than 200 medications, and it can impact all age groups and ethnicities, although it tends to be more common in females than males and is 100 times more prevalent in those with the human immunodeficiency virus ( HIV).
An international team of researchers now have cured seven patients with TEN or a slightly less severe version of the infection, known as Stevens–Johnson syndrome (SJS). None of the patients reported side effects.
All seven people treated with this therapy in their study experienced rapid improvement and a full recovery, in staggering results that have likely unlocked a cure for the condition.
One of those patients was a 59-year-old man who developed TEN across 35 percent of his body after beginning treatment for lung cancer. The patient had lost so much skin, his predicted mortality risk was nearly 60 percent.

Upon taking a novel immune inhibitor, however, his infection stopped progressing. After 16 days, he was almost fully healed.
The class of drugs, called JAK inhibitors (JAKi), seem to work by suppressing an overactive immune pathway.

Scientists discovered the importance of this signaling pathway using skin samples from patients with TEN, to see which individual cells were driving the deadly disease. Altogether, they identified six proteins involved in the JAK/STAT pathway that are upregulated in those with the skin infection.

The JAK/STAT pathway is the main driver of skin inflammation, damaged skin cells, and epidermal detachment.

Using rodent models of TEN, researchers found that one to three days after taking an oral JAK inhibitor, the skin infections had noticeably improved.
All seven patients responded well to the treatment and were discharged in good health, paving the way for a future clinical trial.

https://www.nature.com/articles/s41586-024-08061-0#Sec9

Comment by Dr. Krishna Kumari Challa on November 25, 2024 at 8:09am

Physicists Transformed a Quantum Computer Into a Time Crystal
For the first time, physicists have transformed a quantum processor into a state of matter that seems to defy physics, a breakthrough that could be a step toward making quantum computing more practical.
Quantum computers promise to broaden the kinds of algorithms that can be run quickly and practically, potentially speeding up research into many fields, from particle physics to pharmacology to meteorology.

Monumental progress has been made in developing the technology's foundations, but as the technology scales up, errors become a major obstacle.

By experimentally making a quantum computer behave like a robust form of time crystal, a team of physicists from China and the US hope to make the technology less prone to errors as it scales.

Time crystals are groups of particles that display repeating patterns. Where the patterns that make up regular crystals like diamond and quartz echo through 3D space, time crystals move periodically like a pendulum, tick-tocking through time.

What makes them unique is their ability to do this in absence or in contrast to a driving 'push'. Time crystals oscillate in their lowest energy state to their own rhythm, like a child kicking out in their swing in defiance of their parent's repetitive nudges.

https://www.nature.com/articles/s41467-024-53077-9

Comment by Dr. Krishna Kumari Challa on November 23, 2024 at 12:24pm

Standing at work can be detrimental to blood pressure, study suggests

Hmmm! Whole day sitting is not good. Right.

Now a Finnish study found that prolonged standing at work had a negative impact on the research participants' 24-hour blood pressure. In contrast, spending more time sitting at work was associated with better blood pressure.

The study, published in the journal Medicine & Science in Sports & Exercise, suggests that activity behavior during working hours may be more relevant to 24-hour blood pressure than recreational physical activity.

Regular exercise is important for controlling blood pressure. In particular, more vigorous, aerobic exercise is effective for lowering blood pressure, but everyday physical activity can also have a beneficial impact. Previous studies have shown that exercise in leisure time is more beneficial for the cardiovascular system than physical activity at work, which can even be detrimental to health.

In the Finnish Retirement and Aging study (FIREA) conducted at the University of Turku, the physical activity of municipal employees approaching retirement age was measured using thigh-worn accelerometers during working hours, leisure time, and days off. In addition, the research participants used a portable blood pressure monitor that automatically measured their blood pressure every 30 minutes for 24 hours.

The latest results confirm previous findings that physical activity at work can be harmful to the heart and circulatory system. In particular, prolonged standing can raise blood pressure as the body boosts circulation to the lower limbs by constricting blood vessels and increasing the pumping power of the heart.

A standing desk can provide a nice change from sitting at the office, but too much standing can be harmful. It's a good idea to take a break from standing during the work day, either by walking every half an hour or sitting for some parts of the day, the researchers recommend.

In addition, the results of the study suggest that sedentary work in itself is not necessarily harmful to BP. Instead, researchers stress the importance of recreational physical activity.

It is good to remember that being physically active at work is not enough on its own. Engaging in diverse physical exercise during leisure time helps to maintain fitness, making work-related strain more manageable. Similarly, employees with predominantly sedentary jobs should ensure that they get enough exercise during their leisure time.

Jooa Norha et al, Associations between Leisure and Work Time Activity Behavior and 24 H Ambulatory Blood Pressure among Aging Workers, Medicine & Science in Sports & Exercise (2024). DOI: 10.1249/MSS.0000000000003594

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Comment by Dr. Krishna Kumari Challa on November 23, 2024 at 11:16am

2 million mph galaxy smash-up seen in unprecedented detail

A massive collision of galaxies sparked by one traveling at a scarcely-believable 2 million mph (3.2 million km/h) has been seen in unprecedented detail by one of Earth's most powerful telescopes.

The dramatic impact was observed in Stephan's Quintet, a nearby galaxy group made up of five galaxies first sighted almost 150 years ago.

It sparked an immensely powerful shock akin to a "sonic boom from a jet fighter"—the likes of which are among the most striking phenomena in the universe.

Stephan's Quintet represents "a galactic crossroad where past collisions between galaxies have left behind a complex field of debris", which has now been reawakened by the passage of the galaxy, NGC 7318b.

The collision was spotted by a team of scientists using the first observations from the new 20-million Euro (£16.7million) William Herschel Telescope Enhanced Area Velocity Explorer (WEAVE) wide-field spectrograph in La Palma, Spain.

The discovery of NGC 7318b smashing through Stephan's Quintet was observed by a team of more than 60 astronomers and has been published in Monthly Notices of the Royal Astronomical Society.

M I Arnaudova et al, WEAVE First Light Observations: Origin and Dynamics of the Shock Front in Stephan's Quintet, Monthly Notices of the Royal Astronomical Society (2024). DOI: 10.1093/mnras/stae2235

Comment by Dr. Krishna Kumari Challa on November 22, 2024 at 9:18am

During 30 years of monitoring, 4,356 premature deaths were recorded, including 1,459 from cancer, 304 from cardiovascular diseases, and 90 from respiratory diseases.

Overall, the rate of all-cause premature death for women with and without confirmed endometriosis was 2.0 and 1.4 per 1,000 person years, respectively.

After taking account of age and other confounding factors such as weight (BMI), diet quality, physical activity, and smoking status, endometriosis was associated with a 31% higher risk of premature death, largely driven by deaths due to gynecological cancers.

Uterine fibroids were unrelated to all-cause premature death, but were associated with a greater risk of death due to gynecological cancers.
The researchers acknowledge that these are observational findings that relied on self-reports.
Nevertheless, this was a large study with regular follow-up over nearly three decades, which reduced potential recall errors.
As such, they conclude, "Our results suggest that women with a history of endometriosis and uterine fibroids might have an increased long term risk of premature mortality extending beyond their reproductive lifespan."

"These conditions were also associated with an increased risk of death due to gynecological cancers. Endometriosis was also associated with a greater risk of non-cancer mortality. These findings highlight the importance for primary care providers to consider these gynecological disorders in their assessment of women's health."

 Yi-Xin Wang et al, Endometriosis and uterine fibroids and risk of premature mortality: prospective cohort study, BMJ (2024). DOI: 10.1136/bmj-2023-078797

Part 2

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Comment by Dr. Krishna Kumari Challa on November 22, 2024 at 9:15am

History of endometriosis and fibroids linked to heightened risk of early death, study suggests

Women with a history of endometriosis and uterine fibroids might have an increased long term risk of premature death, finds a large study published by The BMJ .

Endometriosis and uterine fibroids are common disorders among women of reproductive age. Endometriosis occurs when tissue similar to the lining of the womb grows in other places, such as the ovaries and fallopian tubes, while uterine fibroids are non-cancerous growths within or around the womb.

Growing evidence shows that both conditions are associated with a greater long term risk of chronic diseases, such as high blood pressure, heart disease, and some cancers, but their effect on risk of death before the age of 70 remains unclear.

To explore this further, researchers drew on information provided by 110,091 women taking part in the Nurses' Health Study II who were aged 25–42 years in 1989 and had no history of hysterectomy before endometriosis or fibroids diagnosis, cardiovascular diseases, or cancer.
Starting in 1993 and every two years thereafter, these women reported any diagnosis of endometriosis (confirmed by laparoscopy) and uterine fibroids (confirmed by ultrasound or hysterectomy).

Other potentially influential factors including age, ethnicity, reproductive history, HRT and oral contraceptive use, regular use of aspirin or anti-inflammatory drugs, and other health-related issues were also taken into account.

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