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Comment by Dr. Krishna Kumari Challa on October 15, 2023 at 6:32am

Flu-resistant chickens
 Birds with small alterations to one gene are highly resistant to avian flu

Scientists have created the world’s first flu-resistant chickens in an advance that could pave the way for gene-edited poultry. The birds, which had small alterations to one gene, were highly resistant to avian flu, with nine in 10 birds showing no signs of infection when exposed to a typical dose of the virus.

However, infections were not completely blocked, and scientists say this would have to be achieved before genetically engineered chickens could be introduced to farms, due to the risk of the virus evolving to become more dangerous to humans.

https://www.nature.com/articles/s41467-023-41476-3

Comment by Dr. Krishna Kumari Challa on October 14, 2023 at 8:37am

The three types of households with their typical characteristics and food waste behaviours. Credit: Trang Nguyen using Canva.com, CC BY-NC-ND

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 a fire retardant in building materials

Comment by Dr. Krishna Kumari Challa on October 14, 2023 at 8:20am

Targeting a coronavirus ion channel could yield new COVID-19 drugs

The genome of the SARS-CoV-2 virus encodes 29 proteins, one of which is an ion channel called E. This channel, which transports protons and calcium ions, induces infected cells to launch an inflammatory response that damages tissues and contributes to the symptoms of COVID-19.

MIT chemists have now discovered the structure of the "open" state of this channel, which allows ions to flow through. This structure, combined with the "closed" state structure that was reported by the same lab in 2020, could help scientists figure out what triggers the channel to open and close. These structures could also guide researchers in developing antiviral drugs that block the channel and help prevent inflammation.

When SARS-CoV-2 infects cells, the E channel embeds itself inside the membrane that surrounds a cellular organelle called the ER-Golgi intermediate compartment (ERGIC). The ERGIC interior has a high concentration of protons and calcium ions, which the E channel transports out of ERGIC and into the cell cytoplasm. That influx of protons and calcium leads to the formation of multiprotein complexes called inflammasomes, which induce inflammation.

Previous research has shown that when SARS-CoV-2 viruses are mutated so that they don't produce the E channel, the viruses generate much less inflammation and cause less damage to host cells.

So the E channel is an antiviral drug target now. If you can stop the channel from sending calcium into the cytoplasm, then you have a way to reduce the cytotoxic effects of the virus.

Joao Medeiros-Silva et al, Atomic Structure of the Open SARS-CoV-2 E Viroporin, Science Advances (2023). DOI: 10.1126/sciadv.adi9007. www.science.org/doi/10.1126/sciadv.adi9007

Comment by Dr. Krishna Kumari Challa on October 14, 2023 at 8:08am

Research shows wildfire smoke may linger in homes long after initial blaze

Newly published research on indoor air quality  shows wildfire smoke may linger in homes long after the initial blaze has been put out or winds have shifted.

The findings, published in Science Advances, show that wildfire smoke can attach to home surfaces like carpet, drapes or counters—extending the exposure for those inside and potentially causing health problems even after an initial cleaning activity by air purifiers.

However, the research also shows that  surface cleaning—like vacuuming, dusting or mopping—can reduce exposure and limit risk. The team was able to show that the amount of smoke left on surfaces was proportional to the surface area that was cleaned. That means simple cleaning and specifically addressing large but little noticed spaces that may trap harmful compounds such as cabinets and HVAC systems could be beneficial right away.

 Jienan Li et al, The persistence of smoke VOCs indoors: partitioning, surface cleaning, and air cleaning in a smoke-contaminated house, Science Advances (2023). DOI: 10.1126/sciadv.adh8263. www.science.org/doi/10.1126/sciadv.adh8263

Comment by Dr. Krishna Kumari Challa on October 13, 2023 at 12:12pm

Hair Turns Gray Due to Stuck Stem Cells

Hair-colouring stem cells must swing back and forth between their maturity states to give hair its colour.

Like human aging, stem cell maturation is considered a one-way process; once an undifferentiated stem cell goes down the path to become a specific type of cell, there is no turning back. But that does not seem to be the case with melanocyte stem cells (McSC), which give rise to cells that produce hair and skin pigments. 

In a recent study, researchers investigated McSC in hair follicles and found that depending on microenvironment cues, McSCs can fluctuate between undifferentiated and differentiated states. The researchers also found that as the hair follicle ages, a larger number of melanocyte stem cells get stuck in an undifferentiated state, losing their ability to mature and produce melanin. Published in Nature, these results not only challenge the traditional view on how stem cells differentiate, but also offer clues to why hair turns gray with aging. 

The researchers were surprised to find that McSC did not reside in an area called the bulge as previously thought, but were instead located in a compartment known as the hair germ. When the hair started to grow, the McSC transitioned to an intermediate differentiation state from which they either transformed into fully mature melanocytes at the base of the growing hair or moved up to the hair bulge where they stayed as undifferentiated cells. Then these stem cells homed back to the hair germ as the hair entered the resting phase of its growth cycle.

Once they realized that the maturation of these cells depended on their location, the team next investigated which signals within those compartments drove these changes. In the new study, the team found that nearby epithelial cells in the hair germ released Wnt ligands that mature the McSC, but these signals were suppressed in the bulge where the cells regained their undifferentiated features.

Melanocytes give hair its color, and hair pigmentation reduces with aging. So, the researchers wondered what would happen to McSC mobility in an aged hair follicle. To accelerate the aging of hair follicles, the researchers plucked mouse hair to induce regeneration of the follicles and observed McSCs over time. In aged mice, they found more of the stem cells in the bulge area rather than going back to the hair germ.

These findings suggested that as the hair follicle ages, McSC get stuck in a region where less pigment-inducing signals are present. This mechanism might explain why hair turns gray much more rapidly than it falls off.

Although scientists knew that cells could swing back and forth between their maturity states when there were tissue injuries, the study results are exciting as they reveal that dedifferentiation can also occur under a physiological condition.

Since the researchers conducted all of the experiments in mice, questions remain as to whether the same events are also seen in humans.

Sun Q, et al. Dedifferentiation maintains melanocyte stem cells in a dynamic niche. Nature. 2023;616(7958):774-782.

Rabbani P, et al. Coordinated activation of Wnt in epithelial and melanocyte stem cel.... Cell. 2011;145(6):941-955.

Comment by Dr. Krishna Kumari Challa on October 13, 2023 at 11:16am

Monkey lives with gene-edited pig kidney A macaque lived for more than two years with a kidney from a gene-edited miniature pig — one of the longest-lasting interspecies organ transplants. It raises hopes that human organ shortages could one day be alleviated by using organs from donor animals. The donor pigs received 69 gene edits to prevent immune reactions after transplantation and to keep the organ healthy. Of the 15 monkeys that received a transplant, five survived for more than one year and one of those lived for 758 days.

https://www.nature.com/articles/s41586-023-06594-4.epdf?sharing_tok...

Comment by Dr. Krishna Kumari Challa on October 13, 2023 at 10:51am

By the numbers

• 97: Percentage of patients who develop anemia after eight days in the ICU
• 50: Percentage of transfusions given in the ICU in the absence of active bleeding
• 41: Amount of blood (in ml) taken per ICU patient per day for routine blood tests (equivalent of one full blood donation every eight days)
• 75: Percentage of patients who receive at least one blood transfusion within seven days of ICU admission (40% of all ICU patients)
• $450: Cost per unit of blood in Canada (not including indirect costs associated with testing, preparation, storage, administration, reactions)
• 90: Percentage of blood that is wasted in routine lab tests
• 10: Units of blood that could be saved per 100 patients with ICU stays of more than 48 hours if the results of this study were implemented

 Small-Volume Blood Collection Tubes to Reduce Transfusions in Intensive Care, JAMA (2023). DOI: 10.1001/jama.2023.20820. jamanetwork.com/journals/jama/ … 1001/jama.2023.20820

Part 2

Comment by Dr. Krishna Kumari Challa on October 13, 2023 at 10:50am

Large trial shows taking less blood for lab testing reduces transfusions in intensive care

A world-first clinical trial published in JAMA could provide an easy way to save tens of thousands of units of blood every year worldwide.

The trial, which involved more than 27,000 patients in 25 adult intensive care units (ICUs) across Canada, showed that taking less blood for lab tests using "small-volume" tubes reduced the need for almost one blood transfusion for every 10 patients. Most hospitals use standard tubes that automatically draw four to six milliliters (ml) of blood, but a typical laboratory test requires less than 0.5 ml of blood, meaning the rest (more than 90%) is wasted. Commercially available small-volume tubes have a weaker vacuum inside that automatically draws up to half as much blood. "While the amount of blood drawn per tube is relatively small, ICU patients typically require multiple blood samples taken multiple times every day. This can add up to significant blood loss that contributes to anemia, or low red blood cells. ICU patients are unable to produce more red blood cells to correct for this blood loss and often require treatment with a blood transfusion.

This trial showed that we can save one blood transfusion for every 10 ICU patients by simply switching to small-volume tubes for blood collection.

At a time when everyone is trying to find ways to make health care more sustainable, and preserve our supply of blood products, this study provides a simple solution that can be implemented without additional cost or negative effects. The study also has important implications for patients, as low red blood cells (anemia) can leave patients feeling tired and weak and is associated with can lead to other complications and longer hospital stays. While blood transfusions can usually correct anemia, there can be rare side effects, such as difficulty breathing, allergic reactions and infections.
Part 1

Comment by Dr. Krishna Kumari Challa on October 13, 2023 at 10:38am

Restoring nerve-muscle connections boosts strength of aging mice, study finds

A small molecule previously shown to enhance strength in injured or old laboratory mice does so by restoring lost connections between nerves and muscle fibers,  researchers have found.

The molecule, called PGE2, blocks the activity of an aging-associated enzyme, or gerozyme, called 15-PGDH that naturally increases in muscles as they age. The study showed that levels of the gerozyme increase in muscles after nerve damage and that it is prevalent in muscle fibers of people with neuromuscular diseases. The research is the first to show that damaged motor neurons—nerves connecting the spinal cord to muscles—can be induced to regenerate in response to a drug treatment and that lost strength and muscle mass can be at least partially regained. It suggests that, if similar results are seen in humans, the drug may one day be used to prevent muscle loss of muscle strength due to aging or disease or to hasten recovery from injury.

 Mohsen A. Bakooshli et al, Regeneration of neuromuscular synapses after acute and chronic denervation by inhibiting the gerozyme 15-prostaglandin dehydrogenase, Science Translational Medicine (2023). DOI: 10.1126/scitranslmed.adg1485

Comment by Dr. Krishna Kumari Challa on October 13, 2023 at 10:22am

To explore this avenue, the researchers recruited 22 people without sleep disorders and 27 patients with narcolepsy—that is, people who experience uncontrollable episodes of daytime sleepiness. People with narcolepsy have the particularity of having many lucid dreams,  in which they are aware of being asleep; some can sometimes even shape their dream scenario as they wish.

In addition, they easily and quickly enter REM sleep (the stage where lucid dreaming occurs) during the day, making them good candidates for studying consciousness during sleep under experimental conditions.

Participants in the study were asked to take a nap. The researchers gave them a "lexical decision" test, in which a human voice pronounced a series of real and made-up words. Participants had to react by smiling or frowning to categorize them into one or the other of these categories. Throughout the experiment, they were monitored by polysomnography—a comprehensive recording of their brain and heart activity, eye movements, and muscle tone.

Upon waking up, participants had to report whether they had or had not had a lucid dream during their nap and whether they remembered interacting with someone.

Most of the participants, whether narcoleptic or not, responded correctly to verbal stimuli while remaining asleep. These events were certainly more frequent during lucid dreaming episodes, characterized by a high level of awareness. 

By cross-referencing these physiological and behavioral data and the participants' subjective reports, the researchers also showed that it is possible to predict the opening of these windows of connection with the environment, i.e., the moments when sleepers were able to respond to stimuli. They were announced by an acceleration in brain activity and by physiological indicators usually associated with rich cognitive activity.

Türker B. et al. Behavioral and brain responses to verbal stimuli reveal transient periods of cognitive integration of the external world during sleep. Nature Neuroscience (2023). DOI: 10.1038/s41593-023-01449-7. www.nature.com/articles/s41593-023-01449-7

Part 3

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