Many different types of bacteria and viruses can cause pneumonia, but there is no easy way to determine which microbe is causing a particular patient's illness. This uncertainty makes it harder for doctors to choose effective treatments because the antibiotics commonly used to treat bacterial pneumonia won't help patients with viral pneumonia. In addition, limiting the use of antibiotics is an important step toward curbing antibiotic resistance.
One of the primary ways harmful bacteria acquire resistance to antibiotics is by receiving DNA from other bacteria that are already resistant. This DNA exchange is made via a process called conjugation, akin to bacterial sex, whereby two bacteria form an intimate attachment, and one transfers a packet of DNA to the other.
Oregon State University scientists have identified proteins that prevent a bacterial cell from becoming misguided by its own messaging, allowing it to instead wait for collective communication from its group.
Scientists discover and characterize a novel membraneless organelle that could play a role in Alzheimer's treatment
Researchers have discovered a novel organelle—a previously unknown cell structure whose function it is to help clean up faulty proteins in times of stress and keep cells functioning in top condition. Optimizing this membraneless organelle, which they call a BAG2 condensate, could lead to treatments for conditions that are the result of misfolded proteins, including Alzheimer's disease, Parkinson's disease and other neurodegenerative conditions. Their results are reported in a paper and published in the journal Nature Communications.
People have known for quite a while that are a few objects floating around in cells that don't have membranes. And it's never been clear how they're held together, what they are and what they're doing until relatively recently.
Thanks to advanced imaging techniques, scientists have uncovered structures that were once invisible, revealing cells for the truly complex and sophisticated systems that they are.
Of particular interest are biomolecular condensates, which don't have the recognizable cell membrane enclosure, but instead, are separated from the surrounding cytoplasm by a difference in density that can be loosely compared to a drop of oil in water. Thisliquid-liquid phase separationcreates a specialized, relatively concentrated environment for certain functions and reactions. For example, a stress granule is a membraneless organelle that appears when the cell is under stress—maybe there's too much glucose, maybe it's too hot or cold, maybe the cell is experiencing dehydration—and its job is to sweep up RNA floating around in the cytoplasm, storing those genetic instructions and pausing their translation into proteins. If your cell is under stress, you want to shut down making proteins so you can really conserve your energy and get past the stress.
But that's only part of the picture, according to the researchers.
When there's stress, what happens to the proteins that are already in the cell?. If they're under those stress conditions, some of those proteins could get damaged and they could misfold." Misfolds of the tauprotein, for example, can become pathological and turn into theneurofibrillary tanglesthat characterize Alzheimer's disease.
This is where the researchers' newly discovered BAG2 condensate comes in. Named for the BAG2 protein that it contains, the organelle, they found, is capable of sweeping up these faulty proteins in the cytoplasm and stuffing them into a proteasome—the cell's version of a trash can—located in the organelle.
A few proteins form a little barrel, and as the protein is threaded through that little cylinder, it gets degraded. This inactivates and breaks down the protein. Many proteasomes are present in cells at any given time, he added, but what makes this particular proteasome (labeled 20S) special is that it can accept proteins that are already somewhat misfolded and would not fit in the other cellular trash cans.
The limiting cap present on many proteasomes is not there in the BAG2 condensates. These promising results could point to a way to interrupt the development of Alzheimer's disease, which is marked by an accumulation of misfolded tau.
Daniel C. Carrettiero et al, Stress routes clients to the proteasome via a BAG2 ubiquitin-independent degradation condensate, Nature Communications (2022). DOI: 10.1038/s41467-022-30751-4
Shedding light on how bacteria communicate their way to causing infection
Scientists have identified proteins that prevent a bacterial cell from becoming misguided by its own messaging, allowing it to instead wait for collective communication from its group. The research is important because understanding this type of signaling, known as quorum sensing and integral to bacterial pathogens, opens the door to potential new drugs that can disrupt it and thwart infection. Findings were published in the Proceedings of the National Academy of Sciences.
Sometimes single-celled organisms need to work together with other cells. Bacteria and other single-celled microbes can coordinate behaviors and act as a group via quorum sensing, in which cells produce and sense a small chemical signal that is shared within the population. As the signal is released from cells and reaches a high enough concentration in their environment, a quorum is achieved—certain genes are simultaneously activated and specific group behaviors are set in motion.
It's a strength-in-numbers approach that allows bacteria to join forces to do things they could not do by themselves, like causing infection in animals and plants, acquiring certain nutrients and competing against other microbes.
Bacterial infection often involves toxins that only harm the host at high levels, when produced by all bacterial cells at once.
A major unresolved question about quorum sensing, the researchers said, has been why the signal that's produced inside an individual cell is not sensed by that same cell before it is released, spurring the cell into premature, solo action. What prevents signal 'short-circuiting' from happening? A set of proteins called antiactivators are crucial for short-circuit prevention. The proteins work as a quorum sensing "tuner" by causing cells to be less sensitive to the quorum signal.
This research shows how bacteria put the brakes on quorum sensing to achieve true communication in a group.
In addition to helping the quest for new antibiotics that can inhibit quorum sensing in bacterial pathogens, the findings also provide background knowledge useful for the engineering of cells with new properties in a field called synthetic biology.
Antiactivators prevent self-sensing in quorum sensing, Proceedings of the National Academy of Sciences (2022). DOI: 10.1073/pnas.2201242119.
New work upends understanding of how blood is formed
The origins of our blood may not be quite what we thought. Using cellular "barcoding" in mice, a groundbreaking study finds that blood cells originate not from one type of mother cell, but two, with potential implications for blood cancers, bone marrow transplant, and immunology.
Till now people thought that most of our blood comes from a very small number of cells that eventually become blood stem cells, also known as hematopoietic stem cells. Scientists are now surprised to find another group of progenitor cells that do not come from stem cells. They make most of the blood in fetal life until young adulthood, and then gradually start decreasing.
The researchers are now following up to see if the findings also apply to humans. If so, these cells, known as embryonic multipotent progenitor cells (eMPPs), could potentially inform new treatments for boosting aging people's immune systems. They could also shed new light on blood cancers, especially those in children, and help make bone marrow transplants more effective.
Researchers applied a barcoding technique they developed several years ago and documented in Cell. Using either an enzyme known as transposase or CRISPR gene editing, they inserted unique genetic sequences into embryonic mouse cells in such a way that all the cells descended from them also carried those sequences. This enabled the team to track the emergence of all the different types of blood cells and where they came from, all the way to adulthood.
Through barcoding, the researchers found that eMPPs, as compared with blood stem cells, are a more abundant source of most lymphoid cells important to the immune responses, such as B cells and T cells. They think the decrease in eMPPs that they observed with age may explain why people's immunity weakens as they get older.They are now trying to understand why these cells peter out in middle age, which could potentially allow us to manipulate them with the goal of rejuvenating the immune system.
In theory, there could be two approaches: extending the life of eMPP cells, perhaps through growth factors or immune signaling molecules, or treating blood stem cells with gene therapyor other approaches to make them more like eMPPs.
Finally, the recognition that there are two types of mother cells in the blood could revolutionize bone marrow transplant.
Sarah Bowling et al, An Engineered CRISPR-Cas9 Mouse Line for Simultaneous Readout of Lineage Histories and Gene Expression Profiles in Single Cells,Cell(2020).DOI: 10.1016/j.cell.2020.04.048
A Common Epilepsy Drug Causes Birth Defects, And We May Finally Know Why
Valproic acid – a drug commonly used to treat epilepsy and bipolar disorder – can cause birth defects and developmental disorders if taken during pregnancy, but the reason why has long been a mystery.
Now, in a study using mice and human tissue, scientists discovered that the medication locks some embryonic cells into a suspended state where they can't properly grow or divide.
By forcing key stem cellss into this state, called senescence, valproic acid may disrupt brain development in the womb and therefore cause cognitive and developmental disorders down the line, according to the study, published Tuesday (June 14) in the journal PLOS Biology.
An estimated 30 to 40 percent of infants exposed to the drug in the womb develop cognitive impairments orautism spectrum disorder, the study authors noted in their report, and these laboratory studies hint at why that happens.
In a subset of affected children, valproic acid exposure can also cause birth defects beyond the brain, including heart malformations and spina bifida, where part of the spinal column doesn't form properly and thus leaves the spinal cord exposed.
However, the new study suggests that these physical birth defects, though also linked to valproic acid, are triggered by a different mechanism than the cognitive impairment.
Which cells are involved in heart repair and how they communicate with each other
Thousands of people suffer heart attacks every year. In this case, the heart muscle is no longer supplied with sufficient blood and oxygen, and part of the heart muscle tissue dies and becomes scarred. The consequences can range from massive cardiac insufficiency to heart failure. Unlike the liver, the heart of an adult human being cannot regenerate. However, it is able to initiate repair processes. Exactly how these repair processes take place has not been known until now. Therefore, there are still no drugs that can specifically promote healing.
Now a research team has found out which cells are involved in heart repair and how they communicate with each other. The researchers have discovered a new messenger substance that controls wound healing, thus revealing an approach for a new therapy. The research has been published in Science.
The focus of the study is the receptor KIT. The protein is produced by various cells, including the hematopoietic stem cells in the bone marrow. Here, KIT plays an important role as a binding site for the so-called stem cell factor. This messenger substance activates the KIT-positive stem cells and causes them to develop into the various cells of the blood. KIT-positive cells are also found in the heart.
"However, these are not stem cells, as long suspected, but vascular cells. The KIT-positive vascular cells ensure that new heart vessels form after a heart attack. However, the stem cell factor necessary for KIT activation can barely be detected in the heart. The researchers have now resolved this contradiction. They discovered a new messenger substance in the heart that can also bind precisely to the KIT receptor and set the repair process in motion: the protein meteorin-like (METRNL).
After a heart attack, the immune systemreacts with an inflammatory response . The inflammatory cells produce METRNL, which stimulates the KIT-positive vascular cells to form new blood vessels.
Studies in the mouse modelshowed that without METRNL, heart repair no longer worked. In contrast, when mice were treated with METRNL, new vessels formed in the infarct area. This alleviates scarring and prevents severe heart failure.
The newly discovered messenger substance could now be the decisive building block to a drug that specifically supports heart repair.
Marc R. Reboll et al, Meteorin-like promotes heart repair through endothelial KIT receptor tyrosine kinase, Science (2022). DOI: 10.1126/science.abn3027
Electrons take the fast and slow lanes at the same time
Imagine a road with two lanes in each direction. One lane is for slow cars, and the other is for fast ones. For electrons moving along a quantum wire, researchers have discovered that there are also two "lanes," but electrons can take both at the same time!
Current in a wire is carried by the flow of electrons. When the wire is very narrow (one-dimensional, 1D) then electrons cannot overtake each other, as they strongly repel each other. Current, or energy, is carried instead by waves of compression as one particle pushes on the next.
It has long been known that there are two types of excitation for electrons, as in addition to their charge they have a property calledspin. Spin and charge excitations travel at fixed, but different speeds, as predicted by the Tomonaga-Luttinger model many decades ago. However, theorists are unable to calculate what precisely happens beyond only small perturbations, as the interactions are too complex. The Cambridge team has measured these speeds as their energies are varied, and find that a very simple picture emerges (now published in the journalScience Advances). Each type of excitation can have low or high kinetic energy, like cars on a road, with the well-known formulaE=1/2 mv2, which is a parabola. But for spin and charge the massesmare different, and, since charges repel and so cannot occupy the same state as another charge, there is twice as wide a range of momentum for charge as for spin. The results measure energy as a function of magnetic field, which is equivalent to momentum or speedv, showing these two energy parabolas, which can be seen in places all the way up to five times the highest energy occupied by electrons in the system.
It's as if the cars (like charges) are traveling in the slow lane but their passengers (like spins) are going more quickly, in the fast lane! Even when the cars and passengers slow down or speed up, they still remain separate!
These results now open the question of whether this spin-charge separation of the whole electron sea remains robust beyond 1D, e.g., in high-temperature superconducting materials. It may also now be applied to logic devices that harness spin (spintronics), which offer a drastic reduction (by three orders of magnitude!) of the energy consumption of a transistor, simultaneously improving our understanding of quantum matter as well as offering a new tool for engineering quantum materials
Pedro M. T. Vianez et al, Observing separate spin and charge Fermi seas in a strongly correlated one-dimensional conductor, Science Advances (2022). DOI: 10.1126/sciadv.abm2781
Transplanting kidneys without need for immune-suppressing drugs
Physicians have developed a way to provide pediatric kidney transplants without immune-suppressing drugs. Their key innovation is a safe method to transplant the donor's immune system to the patient before surgeons implant the kidney.
The medical team has named the two-transplant combination a "dual immune/solid organ transplant," or DISOT. A scientific paper describing the first three DISOT cases, all performed at Lucile Packard Children's Hospital Stanford, published online June 15 in the New England Journal of Medicine.
This innovation removes the possibility that the recipient will experience immune rejection of their transplanted organ. (Organ rejection is the most common reason for a second organ transplant.) The new procedure also rids recipients of the substantial side effects of a lifetime of immune-suppressing medications, including increased risks for cancer, diabetes, infections and high blood pressure.
The first three DISOT patients were children with a rare immune disease, but the team is expanding the types of patients who could benefit.
The doctors anticipate that the protocol will eventually be available to many people needing kidney transplants, starting with children and young adults, and later expanding to older adults. The researchers also plan to investigate DISOT's utility for other types of solid-organ transplants.
The scientific innovation from the team has another important benefit: It enables safe transplantation between a donor and recipient whose immune systems are genetically half-matched, meaning children can receive stem cell and kidney donations from a parent.
The idea of transplanting a patient with their organ donor's immune system has been around for decades, but it has been difficult to implement. Transplants of stem cells from bone marrow provide the patient with a genetically new immune system, as some of the bone marrow stem cells mature into immune cells in the blood. First developed for people with blood cancers, stem cell transplants carry the risk of the new immune cells attacking the recipient's body, a complication called graft-versus-host disease. Severe GVHD can be fatal.
Researchers working with adult patients have performed sequential stem cell and kidney transplants from living donors. When the donor was half-matched they had partial success, but patients were either unable to completely discontinue immune-suppressing drugs after transplant, or—in other trials not conducted at Stanford—they had unacceptably high risks of severe GVHD.
This new work introduced refinements that greatly improve the success of the two-transplant combination with much lower risk. This key innovation is a change in how the donor's stem cells are processed.
After stem cells are removed from the donor's body, technicians perform alpha-beta T cell depletion, which removes the type of immune cells that cause GVHD. Bertaina's team had showed that alpha-beta T cell depletion—which she developed while working in Italy prior to coming to Stanford—makes stem cell transplants safer and enables genetically half-matched transplants. The protocol is relatively gentle, making it safe for children with immune disorders who are too medically fragile for a traditional stem cell transplant. The alpha-beta T cells recover in the patient after 60 to 90 days, meaning they regain full immune function.
A study finds that injuries to certain areas of the brain were associated with quitting smoking more quickly, easily, and with no cravings.
Astudy of people who effortlessly quit smoking after a stroke or other brain injury—and of those who suffered an injury but then kept smoking—has pinpointed a brain network involved in addiction, researchers reported June 13 in Nature Medicine. Experts say the findings may help identify targets for therapies that could treat addictions.
Keeping objects levitated by sound airborne despite interference
A team of researchers has developed a way to keep objects levitated by sound waves airborne when other objects interfere with the levitation path. In their paper published in the journal Science Advances, the group describes their self-correcting levitation system.
Prior research has shown that it is possible to levitate objects by firing sound waves at them. Because sound waves are nothing more than air particles moving together in a certain way, the object being levitated will fall if an object interferes with the sound waves. In this new effort, the researchers developed new features to address this problem.
To protect the sound waves from interference, the researchers increased the number of speakersused—in their work, they used 256. They also added software to control each of the speakers. The speakers were arranged in a grid and objects were levitated by specifically shaped sound waves. By programming the speakers in specific ways, the team was able to get the system to work together to keep an object above the gridin the air despite interruptions. If some of the soundwaves were blocked, other sound waveswere redirected to take their place.
The researchers proved their system was viable by testing it using a 3D-printed white rabbit as an interference object. Objects were levitated around the rabbit regardless of its location. In one experiment, the researchers levitated beads around the rabbit that formed into a flying butterfly. They also levitated a piece of clear fabric that they used as a screen for projection of the rabbit they had printed. And they levitated a single drop of water over a glass of water, showing that their system would work even when the interfering object was a jiggling glass of liquid.
Ryuji Hirayama et al, High-speed acoustic holography with arbitrary scattering objects, Science Advances (2022). DOI: 10.1126/sciadv.abn7614
Lack of diversity of microorganisms in the gut or elevated gut metabolites implicated in heart failure severity
Some people who experience heart failure have less biodiversity in their gut or have elevated gut metabolites, both of which are associated with more hospital visits and greater risk of death, according to a systematic review of research findings.
The gut microbiome is a delicately balanced ecosystem comprised primarily of bacteria as well as viruses, fungi and protozoa. The microbiome can affect cardiovascular disease, which is a leading cause of death in many parts of the world.
For their overview, the investigators looked at seven years of genetic, pharmacologic and other types of research findings from around the world to generate a wide perspective on how the microbiome can influence heart failure. The investigators zeroed in on one harmful metabolite, trimethylamine-N-oxide (TMAO), that can be produced by churning gut microbiota when full-fat dairy products, egg yolks and red meat are consumed.
The Heart and Gut Relationship: A Systematic Review of the Evaluation of the Microbiome and Trimethylamine-N-Oxide (TMAO) in Heart Failure, Heart Failure Reviews (2022). DOI: 10.1007/s10741-022-10254-6
Scientists develop antimicrobial, plant-based food wrap designed to replace plastic
Aiming to produce environmentally friendly alternatives to plastic food wrap and containers, a scientist has developed a biodegradable, plant-based coating that can be sprayed on foods, guarding against pathogenic and spoilage microorganisms and transportation damage.
The scalable process could potentially reduce the adverse environmental impact of plastic food packaging as well as protect human health.
Their article, published in the science journalNature Food, describes the new kind of packaging technology using the polysaccharide/biopolymer-based fibers. Like the webs cast by the Marvel comic book character Spider-Man, the stringy material can be spun from a heating device that resembles a hair dryer and "shrink-wrapped" over foods of various shapes and sizes, such as an avocado or a sirloin steak. The resulting material that encases food productsis sturdy enough to protect bruising and contains antimicrobial agents to fight spoilage and pathogenic microorganismssuch as E. coli and listeria.
The research paper includes a description of the technology called focused rotary jet spinning, a process by which the biopolymer is produced, and quantitative assessments showing the coating extended the shelf lifeof avocados by 50 percent. The coating can be rinsed off with water and degrades in soil within three days, according to the study.
The new packaging is targeted at addressing a serious environmental issue: the proliferation of petroleum-based plastic products in the waste stream.
High-throughput coating with biodegradable antimicrobial pullulan fibres extends shelf life and reduces weight loss in an avocado model, Nature Food (2022). DOI: 10.1038/s43016-022-00519-6
Scientists transplant human photoreceptors to successfully recover daylight perception in mice
Transplantation of photoreceptor cells is a promising intervention that in the future could help recover vision in people with blinding diseases. A team of researchers developed a robust method to produce high numbers of human photoreceptor cells. The researchers show that such human photoreceptors can incorporate in bulk into partially degenerated mouse retinas. The incorporated photoreceptors developed characteristics of normal photoreceptors and allowed mice with damaged eyesight to detect daylight.
The new study represents a step forward in an effort to bring photoreceptor transplantations to patients with blinding diseases.
To massively increase the number of incorporated photoreceptors, the scientists optimized multiple critical factors. They established that the age of transplanted photoreceptors is decisive.
The team also found that the integration into the retina needs a longer time.
The interaction with the remaining, undamaged cells in the mouse retina turned out to be a key factor. About 30% of the cells in the retina are other cells that support the work of photoreceptors. In this case, researchers clearly saw that the interaction of transplanted cells with host retinal cells was crucial for successful incorporation and maturation. Some of these remaining cells provided a scaffold for the new photoreceptors and helped them organize correctly.
To produce photoreceptors, the team used stem cells to grow mini-retinas in a laboratory dish.
Obtaining a pure population of photoreceptors is yet another challenge. To address it researchers developed a new stem cell line in which cone photoreceptor cells have special tags. These tags do not interfere with their function but allow us to robustly sort photoreceptors from the rest of the cells in the mini-retinas.
Such induced pluripotent stem cell lines provide a virtually unlimited source of photoreceptors and can potentially be used in future clinical applications.
In this study, the team focused on mice with partially degenerated retinas that lacked only one out of two types of photoreceptors. The mice had only damaged cones, which are responsible for daylight vision, a situation similar to several blinding diseases in human patients.
World's biggest giant bacteria that can be seen without a microscope
These thin vermicelli-like threads are revealed to be single bacterial cells!
The unusual size is notable because bacteria aren't usually visible without the assistance of microscope. It's 5,000 times bigger than most bacteria
For most bacteria, their DNA floats freely within the cytoplasm of their cells. This newly discovered species of bacteria keeps its DNA more organized. "The big surprise of the project was to realize that these genome copies that are spread throughout the whole cell are actually contained within a structure that has a membrane. "And this is very unexpected for a bacterium."
It is a bacterium belonging to the genus Thiomargarita,. Scientists named it Ca.Thiomargarita magnifica.
This is a sulfur-oxidizing, carbon fixing bacterium and are important in mangrove eco systems . They contain membrane-bound compartments that contain DNA clusters . Scientists dubbed these organelles "pepins," The bacteria contain three times more genes than most bacteria and hundreds of thousands of genome copies (polyploidy) that are spread throughout the entire cell.
In terms of metabolism, it does chemosynthesis, which is a process analogous to photosynthesis for plants.
A team of researchers from the University of Tokyo, the Korea Research Institute of Bioscience and Biotechnology and the Center for Emergent Matter Science & Thin-Film Device Laboratory RIKEN 2-1 Hirosawa has developed a wearable antimicrobial nanomesh material that sticks to human skin, killing microbes nearly instantly. They have published their creation in Proceedings of the National Academy of Sciences.
Human tear fluids contain many proteins, metabolites, and other molecules whose concentrations change significantly with certain diseases. A research team has now developed a handy test kit for tears that can identify patients with jaundice. Their success is based on a hybrid sensor that simultaneously removes impurities from the sample. This approach could provide new methods for early detection and diagnosis based on complex bodily fluids, as the team reported in the journal Angewandte Chemie International Edition.
The chemical precursors of present-day biomolecules could have formed not only in the deep sea at hydrothermal vents, but also in warm ponds on the Earth's surface. The chemical reactions that may have occurred in this "primordial soup" have now been reproduced in experiments by an international team led by researchers of Friedrich Schiller University Jena, Germany. They even found that one of the nucleobases, which represent the code of our genetic material, could have originated from the surface of our planet
Unlike women, who are born with all the eggs they'll ever have, men can continue to produce sperm throughout their adult lives. To do so, they require a constant renewal of spermatogonial stem cells, which give rise to sperm.
A new study shows that breast cancer metastases form more efficiently while patients are sleeping. This finding could significantly change the way cancer is diagnosed and treated in future.
Breast cancer is one of the most common forms of cancer, according to the World Health Organization (WHO). Each year, around 2.3 million people worldwide contract the disease. If doctors detect breast cancer early enough, patients usually respond well to treatment. However, things become much more difficult if the cancer has already metastasised. Metastasis occurs when circulating cancer cells break away from the original tumour, travel through the body via blood vessels and form new tumours in other organs.
To date, cancer research has not paid much attention to the question of when tumours shed metastatic cells. Researchers previously assumed that tumours release such cells continuously. However, a new study by researchers at ETH Zurich, the University Hospital Basel and the University of Basel has now come to a surprising conclusion: circulating cancer cells that later form metastases mainly arise during the sleep phase of the affected individuals. The results of the study have just been published in the journal Nature.
Circadian rhythm-regulated hormones control metastasis When the affected person is asleep, the tumour awakens!
The researchers found that the tumour generates more circulating cells when the organism is asleep. Cells that leave the tumour at night also divide more quickly and therefore have a higher potential to form metastases, compared to circulating cells that leave the tumour during the day.
This research shows that the escape of circulating cancer cells from the original tumour is controlled by hormones such as melatonin, which determine our rhythms of day and night.
The study indicates that the time in which tumour or blood samples are taken for diagnosis may influence the findings of oncologists. It was an accidental finding along these lines that first put the researchers on the right track. Some scientists work early in the morning or late in the evening; sometimes they’ll also analyse blood at unusual hours. The scientists were surprised to find that samples taken at different times of the day had very different levels of circulating cancer cells.
Another clue was the surprisingly high number of cancer cells found per unit of blood in mice compared to humans. The reason was that as nocturnal animals, mice sleep during the day, which is when scientists collect most of their samples. These findings may indicate the need for healthcare professionals to systematically record the time at which they perform biopsies.
The researchers’ next step will be to figure out how these findings can be incorporated into existing cancer treatments to optimise therapies.
Zoi Diamantopoulou, Francesc Castro-Giner, Fabienne Dominique Schwab, Christiane Foerster, Massimo Saini, Selina Budinjas, Karin Strittmatter, Ilona Krol, Bettina Seifert, Viola Heinzelmann-Schwarz, Christian Kurzeder, Christoph Rochlitz, Marcus Vetter, Walter Paul Weber, Nicola Aceto. The metastatic spread of breast cancer accelerates during sleep. Nature, 2022; DOI: 10.1038/s41586-022-04875-y
Environmental factors predict risk of death: study
Along with high blood pressure, diabetes, and smoking, environmental factors such as air pollution are highly predictive of people's chances of dying, especially from heart attack and stroke, a new study shows.
the study showed that exposure to above average levels of outdoor air pollution increased risk of death by 20%, and risk of death from cardiovascular diseaseby 17%.
Using wood- or kerosene-burning stoves, not properly ventilated through a chimney, to cook food or heat the home also increasd overall risk of death (by 23% and 9%) and cardiovascular death risk (by 36% and 19%). Living far from specialty medical clinicsand near busy roads also increased risk of death.
Publishing in the journalPLOS ONEonline June 24, the findings come from personal and environmental health data collected from 50,045 mostly poor, rural villagers living in the northeast Golestan region of Iran. All study participants were over age 40 and agreed to have their health monitored during annual visits with researchers dating as far back as 2004.
Researchers say their latest investigation not only identifies environmental factors that pose the greatest risk to heart and overall health, but also adds much-needed scientific evidence from people in low- and middle -income countries
Spatial environmental factors predict cardiovascular and all-cause mortality: Results of the SPACE Study, PLoS ONE (2022).
Octopus brain and human brain share the same 'jumping genes'
The octopus is an exceptional organism with an extremely complex brain and cognitive abilities that are unique among invertebrates. So much so that in some ways it has more in common with vertebrates than with invertebrates. The neural and cognitive complexity of these animals could originate from a molecular analogy with the human brain, as discovered by a research paper recently published in BMC Biology.
The research shows that the same "jumping genes" are active both in the human brain and in the brain of two species, Octopus vulgaris, the common octopus, and Octopus bimaculoides, the Californian octopus. This discovery could help us understand the secret of the intelligence of these fascinating organisms.
Sequencing the human genome revealed as early as 2001 that over 45% of it is composed of sequences called transposons, so-called "jumping genes" that, through molecular copy-and-paste or cut-and-paste mechanisms, can "move" from one point to another of an individual's genome, shuffling or duplicating. In most cases, these mobile elements remain silent: they have no visible effects and have lost their ability to move. Some are inactive because they have, over generations, accumulated mutations; others are intact, but blocked by cellular defense mechanisms. From an evolutionary point of view, even these fragments and broken copies of transposons can still be useful, as "raw matter" that evolution can sculpt.
Among these mobile elements, the most relevant are those belonging to the so-called LINE (Long Interspersed Nuclear Elements) family, found in a hundred copies in the human genome and still potentially active. It has been traditionally thought that LINEs' activity was just a vestige of the past, a remnant of the evolutionary processes that involved these mobile elements, but in recent years new evidence emerged showing that their activity is finely regulated in the brain. There are many scientists who believe that LINE transposons are associated with cognitive abilities such as learning and memory: they are particularly active in the hippocampus, the most important structure of our brain for the neural control of learning processes.
The octopus' genome, like ours, is rich in "jumping genes," most of which are inactive. Focusing on the transposons still capable of copy-and-paste, the researchers identified an element of the LINE family in parts of the brain crucial for the cognitive abilities of these animals. The discovery was made possible thanks to next generation sequencing techniques, which were used to analyze the molecular composition of the genes active in the nervous system of the octopus.
The discovery of an element of the LINE family, active in the brain of the two octopuses species, is very significant because it adds support to the idea that these elements have a specific function that goes beyond copy-and-paste.
The brain of the octopus is functionally analogous in many of its characteristics to that of mammals. For this reason, also, the identified LINE element represents a very interesting candidate to study to improve our knowledge on the evolution of intelligence.
“Identification of LINE retrotransposons and long non-coding RNAs expressed in the octopus brain” by Giuseppe Petrosino, Giovanna Ponte, Massimiliano Volpe, Ilaria Zarrella, Federico Ansaloni, Concetta Langella, Giulia Di Cristina, Sara Finaurini, Monia T. Russo, Swaraj Basu, Francesco Musacchia, Filomena Ristoratore, Dinko Pavlinic, Vladimir Benes, Maria I. Ferrante, Caroline Albertin, Oleg Simakov, Stefano Gustincich, Graziano Fiorito and Remo Sanges, 18 May 2022, BMC Biology. DOI: 10.1186/s12915-022-01303-5
Monkeypox found to be evolving at a faster rate than expected
A team of researchers has found that the monkeypox virus has been evolving at a faster rate than expected. In their paper published in the journal Nature Medicine, the researchers describe their genetic study of the virus collected from 15 samples
Monkeypox is a double-stranded DNA virus from the same genus as smallpox, and it mostly infects people in Africa. Scientist have known of its existence since the 1950s. Despite its name, the virus is more commonly found in rodents than monkeys. Prior research has shown that there are two main varieties of monkeypox: West African and Congo Basin—the former is far less deadly and is the clade that has infected several thousand people outside Africa. Prior research has also shown that viruses like monkeypox typically only mutate once or twice in a given year.
In this new effort, the researchers collected samples from 15 patients and subjected them to genetic analysisto learn more about how quickly the virus is evolving. They found the virus has mutated at a rate six to 12 times as high as was expected. The researchers suggest the sudden accelerated rate of mutation in the virus may be a sign that the virus has developed a new way to infect people—currently, it is believed to move from person to person through close contact with open lesions, through body fluids or by airborne droplets.
Joana Isidro et al, Phylogenomic characterization and signs of microevolution in the 2022 multi-country outbreak of monkeypox virus, Nature Medicine (2022). DOI: 10.1038/s41591-022-01907-y
In studying the mutations, the researchers found signs suggesting that some of the mutations may have been due to exposure to thehuman immune system, most particularly enzymes of a type called APOBEC3—they kill viruses by inciting mistakes during copying ofgenetic code. If some of the viruses survived such an attack and passed on their genes, they would have givenfuture generationsa leg up against the human immune system. And that could explain why the virus has been mutating more rapidly than expected. The researchers also note that the virus may have been circulating at low levels in human communities or spreading among animals in other countries. They also note that the accelerated rate of evolution could be a response to the crackdown that ensued during the monkeypox outbreak in 2017.
Virus discovery offers clues about origins of complex life
The first discovery of viruses infecting a group of microbes that may include the ancestors of all complex life has been found, researchersreport inNature Microbiology. The discovery offers tantalizing clues about the origins of complex life and suggests new directions for exploring the hypothesis that viruses were essential to the evolution of humans and other complex life forms.
This study is opening a door to better resolving the origin of eukaryotes and understanding the role of viruses in the ecology and evolution of Asgard archaea. There is a hypothesis that viruses may have contributed to the emergence of complex cellular life.
There is a hypothesis called viral eukaryogenesis. It suggests that, in addition to bacteria and archaea, viruses might have contributed some genetic component to the development of eukaryotes. This latest discovery does not settle that debate, but it does offer some interesting clues.
The newly discovered viruses that infect currently living Asgard archaea do have some features similar to viruses that infect eukaryotes, including the ability to copy their own DNA and hijack protein modification systems of their hosts. The fact that these recovered Asgard viruses display characteristics of both viruses that infect eukaryotes and prokaryotes, which have cells without a nucleus, makes them unique since they are not exactly like those that infect other archaea or complex life forms.
The most exciting thing is they are completely new types of viruses that are different from those that we've seen before in archaea and eukaryotes, infecting our microbial relatives.
The Asgard archaea, which probably evolved more than 2 billion years ago and whose descendents are still living, have been discovered in deep sea sediments and hot springs around the world, but so far only one strain has been successfully grown in the lab. To identify them, scientists collect their genetic material from the environment and then piece together their genomes. In this latest study, the researchers scanned the Asgard genomes for repeating DNA regions known as CRISPR arrays, which contain small pieces of viral DNA that can be precisely matched to viruses that previously infected these microbes. These genetic "fingerprints" allowed them to identify these stealthy viral invaders that infect organisms with key roles in the complex origin story of eukaryotes.
We are now starting to understand the implication and role that viruses could have had in the eukaryogenesis puzzle.
Humanity must heal oceans made sick by climate change, pollution and overfishing in order to rescue marine life and save ourselves, experts warned ahead of a major UN conference.
By absorbing—decade after decade—a quarter of CO2 pollution and more than 90 percent of excess heat from global warming, oceans have kept Earth's terrestrial surface liveable.
Our species has returned the favor by dumping mountains of plastic waste into the sea, emptying the deep blue of big fish, and poisoning coastlines with toxic chemicals and agricultural runoff that create dead zones bereft of oxygen.
"If we don't do the right things now, we might end up with a dead oceans”
Functional connections between different brain networks can predict a person's age
Neuroscientists have been trying to understand for decades how the human brain changes over the lifespan. This could ultimately help to devise more effective treatments for neurological and cognitive disorders primarily observed in the elderly.
Researchers have recently carried out a study investigating the relationship between age and the functional coupling between specific neural networks in the brain. Their paper, published in Psychology and Aging, shows that the connectivity between certain brain regions can predict people's chronological age with a high level of accuracy.
The differences in cognitive functioning among people of different ages are well documented. The idea that these differences are associated with changes in brain connectivity (i.e., the way in which brain regions and networks communicate with each other) was introduced and discussed in many neuroscience papers.
The present one deals with the Q:Can we use patterns of brain connectivity when people are not doing any tasks to predict their age?
Scientists analyzed data collected from a large cohort of 547 participants between 18 and 88 years old, part of a publicly available brain imaging dataset compiled by theCambridge Centre for Aging and Neuroscience (CamCAN). By analyzing these data, they firstly investigated whether connectivity between the executive control network (ECN) and default mode network (DMN) regions in the brain can predict age.
To do this, they used a well-established statistical technique called multiple regression analysis. They further examined how connectivity between ECN, DMN, and another region, the salience network (SN)—which is thought to mitigate how ECN and DMN regions talk to each other—impacts the strength of the connections between ECN and DMN areas.
The analyses carried out now yielded many interesting findings. Most notably, the results showed that the functional connectivity between large-scale brain networks can predict age with good accuracy and that it varies across the lifespan. More specifically, they found that the connectivity between ECN and DMN brain regions accounts for a significant portion of age variability.
Interestingly, the researchers found that when they also included the SN (a set of brain regionsthat selects salient external or internal stimuli for the brain to focus its attention on) in their analyses, they could predict a person's age with even greater accuracy. In the future, their work could help to better understand the brain connectivity patterns associated with the decline in cognitive abilities observed in older age.
Evangelia G. Chrysikou et al, Large-scale network connectivity as a predictor of age: Evidence across the adult lifespan from the Cam-CAN data set, Psychology and Aging (2022). DOI: 10.1037/pag0000683
Bacteria's shapeshifting behaviour clue to new treatments for urinary tract infections
Urinary tract infections are both very common and potentially very dangerous. Thousands of women suffer from a UTI in their lifetime, and most of these women will have an infection requiring treatment with antibiotics.
Around 80 percent of UTIs are caused by uropathogenic E. coli (UPEC), which is increasingly resistant to antibiotics. E. coli-related death due to antimicrobial resistance is the leading cause of bacterial fatalities worldwide.
In a bid to aid discovery of new treatment options, researchers are using state-of-the-art microscopy to pinpoint how these bacteria spread and multiply.
The latest research examined the shapeshifting behavior of UPEC. During a UTI infection cycle, the bacteria form spaghetti-like filaments hundreds of times their normal lengths before reverting to their original form.
The study, which is published inNature Communications, used a human bladder cell infection model to generate the filaments, and look at their reversal back to rod shape.
While we don't fully understand why they do this extreme lifestyle make-over, we know they must revert to their original size before they can reinfect new bladder cells.
Researchers used advanced microscopy to follow two key cell division proteins and their localisation dynamics during reversal. We found that the normal rules for regulation of cell division in bacteria does not fully apply in filaments.
By giving the first clues into how the reversal of filamentation is regulated during infection, scientists may be laying the foundation for identifying new ways to combat UTIs.
The long filaments formed by the bacteria appeared to break open the infected human cells, through a previously unknown mechanism called infection-related filamentation (IRF).
The devastating eruption of these bacteria from the cellsof the bladder that they invade probably contributes to the extensive damage and pain experienced during a UTI.
If scientists identify why and how the bacteria shifts their shapes this enables alternative treatments or preventions.
Bill Söderström et al, Assembly dynamics of FtsZ and DamX during infection-related filamentation and division in uropathogenic E. coli, Nature Communications (2022). DOI: 10.1038/s41467-022-31378-1
Life in the Earth's interior is as productive as in some ocean waters
Terrestrial and marine habitats have been considered the ecosystems with the highest primary production on Earth by far. Microscopic algae in the upper layers of the oceans and plants on land bind atmospheric carbon (CO2) and produce plant material driven by photosynthesis. Since sunlight does not penetrate into the subsurface, hardly any such primary production is to be expected.
However, genetic analyses of microorganisms ingroundwaterhave indicated that even here many microorganisms are capable of primary production. In the absence of light, they must obtain the energy from oxidizinginorganic compounds, like from reduced sulfur of the surrounding rocks. However, the role of primary producers in the subsurface had never been confirmed before.
Groundwater is one of our most important sources of clean drinking water. The groundwater environment of the carbonate aquifers alone, which is the focus of the study, provides about ten percent of the world's drinking water. With this in mind, the researchers carried out measurements of microbial microorganism carbonfixation in a subsurface aquifer, 5 to 90 meters belowground.
Based on the measured carbon fixation rates, the researchers conservatively extrapolated global primary production in carbonate groundwater to be 110 million metric tons of carbon per year. Collectively, the net primary productivity of approximately 66 percent of the planet's groundwater reservoirs would total 260 million metric tons of carbon per year, which is approximately 0.5 percent that of marine systems and 0.25 percent of global net primary production estimates.
Since there is very little energy available in these nutrient-poor and permanently dark habitats, even a small percentage of the global primary production is a surprise.
The researchers also sought to identify the microorganisms responsible for fixing carbon and generating new biomass within the aquifer. Metagenomic analyses point to a highly abundant microorganism not closely related to previously studied bacteria, within an uncharacterized order of Nitrospiria. As food, these organisms are thought to form the basis of life for the entire groundwater ecosystem with all of its thousands of microbial species, similar to the role algae play in the oceans or plants on land.
Scientists in Thailand have established that a cat passed SARS-CoV-2 to a veterinary surgeon. Given the scale of the pandemic and the close contact between cats and people, some researchers are not surprised. But establishing the direction of viral spread — from cat to person or from person to cat — is tricky. In this case,a cat belonging to a COVID-19-positive family sneezed in the face o.... Such cases of cat-to-human transmission are probably rare, and researchers emphasize that people should care for their cats — and perhaps take extra precautions when handling cats that might be infected — and not abandon them.
Slicing through an onion damages cells, causing enzymes and other substances that are normally kept apart to spill out and react together. In standard onions the result is a sulphur-containing chemical called syn-propanethial-S-oxide, which resembles tear gas. This forms an irritating acid when it comes into contact with water in your eyes.
Some research groups have created onions that are genetically modified to lack an enzyme that leads to syn-propanethial-S-oxide, but these have not yet made it to market.
The tearless onions –Sunions– now in shops were created by repeatedly cross-breeding milder varieties containing lower levels of pyruvate. This substance is a by-product of the same reaction that forms syn-propanethial-S-oxide and also has a good measure of pungency.
Turning methane into methanol under ambient conditions using light
An international team of researchers has developed a fast and economical method of converting methane, or natural gas, into liquid methanol at ambient temperature and pressure. The method takes place under continuous flow over a photo-catalytic material using visible light to drive the conversion.
To help observe how the process works and how selective it is, the researchers used neutron scattering at the VISION instrument at Oak Ridge National Laboratory's Spallation Neutron Source.
The method involves a continuous flow of methane/oxygen-saturated water over a novel metal-organic framework (MOF) catalyst. The MOF is porous and contains different components that each have a role in absorbing light, transferring electrons and activating and bringing together methane and oxygen. The liquid methanol is easily extracted from the water. Such a process has commonly been considered "a holy grail of catalysis" and is an area of focus for research supported by the U.S. Department of Energy. Details of the team's findings, titled "Direct photo-oxidation of methane to methanol over a mono-iron hydroxyl site," are published inNature Materials.
Scientists discover norovirus and other 'stomach viruses' can spread through saliva
A class of viruses known to cause severe diarrheal diseases—including the one famous for widespread outbreaks on cruise ships—can grow in the salivary glands of mice and spread through their saliva, scientists have discovered. The findings show that a new route of transmission exists for these common viruses, which afflict billions of people each year worldwide and can be deadly.
The transmission of these so-called enteric viruses through saliva suggests that coughing, talking, sneezing, sharing food and utensils, and even kissing all have the potential for spreading the viruses. The new findings still need to be confirmed in human studies.
The findings, which appear in the journal Nature, could lead to better ways to prevent, diagnose, and treat diseases caused by these viruses, potentially saving lives.
Researchers have known for some time that enteric viruses, such as noroviruses and rotaviruses, can spread by eating food or drinking liquids contaminated with fecal matter containing these viruses. Enteric viruses were thought to bypass the salivary gland and target the intestines, exiting later through feces. Although some scientists have suspected there may be another route of transmission, this theory remained largely untested until now.
Now researchers will need to confirm that salivary transmission of enteric viruses is possible in humans. If they find that it is, the researchers said, they may also discover that this route of transmission is even more common than the conventional route. A finding such as that could help explain, they said, why the high number of enteric virus infections each year worldwide fails to adequately account for fecal contamination as the sole transmission route.
A new COVID-19 antibody detection method that does not require a blood sample
A key challenge in limiting the spread of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is identifying infected individuals. Now, investigators have developed a new antibody-based method for the rapid and reliable detection of SARS-CoV-2 that does not require a blood sample.
The ineffective identification of SARS-CoV-2-infected individuals has severely limited the global response to the COVID-19 pandemic, and the high rate of asymptomatic infections (16%–38%) has exacerbated this situation. The predominant detection method to date collects samples by swabbing the nose and throat. However, the application of this method is limited by its long detection time (4–6 hours), high cost, and requirement for specialized equipment and medical personnel, particularly in resource-limited countries.
An alternative and complementary method for the confirmation of COVID-19 infection involves the detection of SARS-CoV-2-specific antibodies. Testing strips based on gold nanoparticles are currently in widespread use for point-of-care testing in many countries. They produce sensitive and reliable results within 10–20 minutes, but they require blood samples collected via a finger prick using a lancing device. This is painful and increases the risk of infection or cross-contamination, and the used kit components present a potential biohazard risk.
To develop a minimally invasive detection assay that would avoid these drawbacks, researchers explored the idea of sampling and testing theinterstitial fluid(ISF), which is located in the epidermis and dermis layers of human skin. Although the antibody levels in the ISF are approximately 15%–25% of those in blood, it was still feasible that anti-SARS-CoV-2 IgM/IgG antibodies could be detected and that ISF could act as a direct substitute for blood sampling."
After demonstrating that ISF could be suitable for antibody detection, the researchers developed an innovative approach to both sample and test the ISF. They first developed biodegradable porous microneedles made of polylactic acid that draws up the ISF from human skin.
Then, they constructed a paper-based immunoassay biosensor for the detection of SARS-CoV-2-specific antibodies. By integrating these two elements, the researchers created a compact patch capable of on-site detection of the antibodies within 3 minutes (result from in vitro tests).
This novel detection device has great potential that is safe and acceptable to patients for the rapid screening of COVID-19 and many other infectious diseases. It holds promise for use in many countries regardless of their wealth, which is a key aim for the global management of infectious disease.
Anti SARS CoV 2 IgM/IgG antibodies detection using a patch sensor containing porous microneedles and a paper based immunoassay, Scientific Reports (2022). DOI: 10.1038/s41598-022-14725-6
Could carbon monoxide foam help fight inflammation?
Carbon monoxide is best known as a potentially deadly gas. However, in small doses it also has beneficial qualities: It has been shown to reduce inflammation and can help stimulate tissue regeneration.
We’ve known for years that carbon monoxide can impart beneficial effects in all sorts of disease pathologies, when given as an inhaled gas. However, it’s been a challenge to use it in the clinic, for a number of reasons related to safe and reproducible administration, and health care workers’ concerns, which has led to people wanting to find other ways to administer it.
A team of researchers has now devised a novel way to deliver carbon monoxide to the body while bypassing its potentially hazardous effects. Inspired by techniques used in molecular gastronomy, they were able to incorporate carbon monoxide into stable foams that can be delivered to the digestive tract.
In a study of mice, the researchers showed that these foams reduced inflammation of the colon and helped to reverse acute liver failure caused by acetaminophen overdose. The new technique, described earlier this week in a Science Translational Medicine paper, could also be used to deliver other therapeutic gases, the researchers say.
The ability to deliver a gas opens up whole new opportunities of how we think of therapeutics. We generally don’t think of a gas as a therapeutic that you would take orally (or that could be administered rectally), so this offers an exciting new way to think about how we can help patients.
Since the late 1990s, researchers have been studying the therapeutic effects of low doses of carbon monoxide. The gas has been shown to impart beneficial effects in preventing rejection of transplanted organs, reducing tumor growth, and modulating inflammation and acute tissue injury.
When inhaled at high concentrations, carbon monoxide binds to hemoglobin in the blood and prevents the body from obtaining enough oxygen, which can lead to serious health effects and even death. However, at lower doses, it has beneficial effects such as reducing inflammation and promoting tissue regeneration.
To tackle the challenge of delivering a gas, researchers came up with the idea of incorporating the gas into a foam, much the way that chefs use carbon dioxide to create foams infused with fruits, vegetables, or other flavours.
Culinary foams are usually created by adding a thickening or gelling agent to a liquid or a solid that has been pureed, and then either whipping it to incorporate air or using a specialized siphon that injects gases such as carbon dioxide or compressed air.
The team created a modified siphon that could be attached to any kind of gas cannister, allowing them to incorporate carbon monoxide into their foam. To create the foams, they used food additives such as alginate, methyl cellulose, and maltodextrin. Xantham gum was also added to stabilize the foams. By varying the amount of xantham gum, the researchers could control how long it would take for the gas to be released once the foams were administered.
After showing that they could control the timing of the gas release in the body, the researchers decided to test the foams for a few different applications. First, they studied two types of topical applications, analogous to applying a cream to soothe itchy or inflamed areas. In a study of mice, they found that delivering the foam rectally reduced inflammation caused by colitis or radiation-induced proctitis (inflammation of the rectum that can be caused by radiation treatment for cervical or prostate cancer).
Current treatments for colitis and other inflammatory conditions such as Crohn’s disease usually involve drugs that suppress the immune system, which can make patients more susceptible to infections. Treating those conditions with a foam that can be applied directly to inflamed tissue offers a potential alternative, or complementary approach, to those immunosuppressive treatments, the researchers say. While the foams were given rectally in this study, it could also be possible to deliver them orally, the researchers say.
Study explores coevolution of mammals and their lice
According to a new study, the first louse to take up residence on a mammalian host likely started out as a parasite of birds. That host-jumping event tens of millions of years ago began the long association between mammals and lice, setting the stage for their coevolution and offering more opportunities for the lice to spread to other mammals.
Reported in the journal Nature Ecology and Evolution, the study compared the genomes and family trees of lice and their mammalian hosts. The effort revealed that the two trees share a lot of parallel branches and twigs. Those branching points—where one group of mammals began diverging into new forms—often were echoed in the genomes of the lice that parasitized those mammals, the researchers reported.
In this paper, researchers used data from genome sequencing to show that a major newly recognized group of mammalian lice, including lice of humans, originated on the common ancestor of Afrotheria, a group of mammals primarily of African distribution that includes elephants, hyraxes and elephant shrews, among others. These lice then went on to colonize other major groups of mammals through the process of host switching.
Lice fall into two groups based on their eating habits. Chewing lice munch on skin or secretions, while sucking lice pierce the skin to consume the blood of their hosts. Both types feed on mammals, but sucking lice are exclusive to mammals.
Recent genomic studies revealed that sucking lice are closely related to two groups of chewing lice that also feed on mammals, and "each of the major groups within this newly identified lineage occurs on at least one member of Afrotheria.
8,000 kilometers per second: Star with the shortest orbital period around black hole discovered
Researchers have discovered the fastest known star, which travels around a black hole in record time. The star, S4716, orbits Sagittarius A*, the black hole in the center of our Milky Way, in four years and reaches a speed of around 8,000 kilometers per second. S4716 comes as close as 100 AU (astronomical unit) to the black hole—a small distance by astronomical standards. One AU corresponds to 149,597,870 kilometers. The study has been published in The Astrophysical Journal.
Florian Peißker et al, Observation of S4716—a Star with a 4 yr Orbit around Sgr A*, The Astrophysical Journal (2022). DOI: 10.3847/1538-4357/ac752f
LHCb discovers three new exotic particles: the pentaquark and the first-ever pair of tetraquarks
The international LHCb collaboration at the Large Hadron Collider (LHC) has observed three never-before-seen particles: a new kind of pentaquark and the first-ever pair of tetraquarks, which includes a new type of tetraquark. The findings, presented recently at a CERN seminar, add three new exotic members to the growing list of new hadrons found at the LHC. They will help physicists better understand how quarks bind together into these composite particles.
Quarks are elementary particles and come in six flavors: up, down, charm, strange, top and bottom. They usually combine together in groups of twos and threes to form hadrons such as the protons and neutrons that make up atomic nuclei. More rarely, however, they can also combine into four-quark and five-quark particles, or "tetraquarks" and "pentaquarks." These exotic hadrons were predicted by theorists at the same time as conventional hadrons, about six decades ago, but only relatively recently, in the past 20 years, have they been observed by LHCb and other experiments.
Most of the exotic hadrons discovered in the past two decades are tetraquarks or pentaquarks containing a charm quark and a charm antiquark, with the remaining two or three quarks being an up, down or strange quark or their antiquarks. But in the past two years, LHCb has discovered different kinds of exotic hadrons. Two years ago, the collaboration discovered a tetraquark made up of two charm quarks and two charm antiquarks, and two "open-charm" tetraquarks consisting of a charm antiquark, an up quark, a down quark and a strange antiquark. And last year it found the first-ever instance of a "double open-charm" tetraquark with two charm quarks and an up and a down antiquark. Open charm means that the particle contains a charm quark without an equivalent antiquark.
The discoveries announced now by the LHCb collaboration include new kinds of exotic hadrons. The first kind, observed in an analysis of "decays" of negatively charged B mesons, is a pentaquark made up of a charm quark and a charm antiquark and an up, a down and a strange quark. It is the first pentaquark found to contain a strange quark. The finding has a whopping statistical significance of 15 standard deviations, far beyond the 5 standard deviations that are required to claim the observation of a particle in particle physics.
The second kind is a doubly electrically charged tetraquark. It is an open-charm tetraquark composed of a charm quark, a strange antiquark, and an up quark and a down antiquark, and it was spotted together with its neutral counterpart in a joint analysis of decays of positively charged and neutral B mesons. The new tetraquarks, observed with a statistical significance of 6.5 (doubly charged particle) and 8 (neutral particle) standard deviations, represent the first time a pair of tetraquarks has been observed.
Defining the Anthropocene: Radioactive traces in ocean materials mark the start of the modern age
For the first time, researchers can offer a strong quantitative definition for the start of what is known as the Anthropocene, thanks to traces of radioactive material in marine sediments and corals. The Anthropocene period is considered important by researchers in many fields as it effectively marks a milestone for humanity's impact on Earth's environment and ecosystem.
Researchers combined records of nuclear fallout from atomic tests present in ocean sediments and coral skeletons. These records show a clear change in the ocean environment before, during and after a period of worldwide atomic testing, which the researchers have defined as marking the beginning of the Anthropocene.
Yusuke Yokoyama et al, Plutonium isotopes in the North Western Pacific sediments coupled with radiocarbon in corals recording precise timing of the Anthropocene, Scientific Reports (2022). DOI: 10.1038/s41598-022-14179-w
Scientists unravel the key to colon cancer relapse after chemotherapy
Approximately 1 in 25 people will develop colon cancer during their lifetime and nearly 2 million cases new cases are diagnosed worldwide each year. Chemotherapy is commonly used to treat colon cancer. While this treatment is initially effective in most cases, many patients relapse after treatment.
This study reveals that some tumor cells remain in a latent state and, after chemotherapy, they are reactivated, thus causing relapse. Their study is published in Nature Cancer.
In short, scientists have discovered that tumor stem cells with Mex3a protein activity remain in a state of latency that confers resistance to chemotherapy. Due to the action of the drugs used in this treatment, these cells adopt a state similar to the embryonic one, and sometime after chemotherapy, when the environment is more favorable, they are reactivated to regenerate the tumor in all its complexity. These persistent cells are responsible for cancer relapse after treatment.
Physicists see electron whirlpools for the first time
Though they are discrete particles, water molecules flow collectively as liquids, producing streams, waves, whirlpools, and other classic fluid phenomena.
Not so with electricity. While an electric current is also a construct of distinct particles—in this case,electrons—the particles are so small that anycollective behavioramong them is drowned out by larger influences as electrons pass through ordinary metals. But, in certain materials and under specific conditions, such effects fade away, and electrons can directly influence each other. In these instances, electrons can flow collectively like a fluid.
Now, physicists have observed electrons flowing in vortices, or whirlpools—a hallmark of fluid flow that theorists predicted electrons should exhibit, but that has never been seen until now.
It's a clear signature where electrons behave as a fluid, not as individual particles.
The observations, reported in the journalNature, could inform the design of more efficient electronics.
When electrons go in a fluid state, [energy] dissipation drops, and that's of interest in trying to design low-power electronics. This new observation is another step in that direction.
Mathematical calculations show that quantum communication across interstellar space should be possible
A team of physicists has used mathematical calculations to show that quantum communications across interstellar space should be possible. In their paper published in the journal Physical Review D, the group describes their calculations and also the possibility of extraterrestrial beings attempting to communicate with us using such signaling.
Over the past several years, scientists have been investigating the possibility of using quantum communications as a highly secure form of message transmission. Prior research has shown that it would be nearly impossible to intercept such messages without detection. In this new effort, the researchers wondered if similar types of communications might be possible acrossinterstellar space. To find out, they usedmaththat describes that movement of X-rays across a medium, such as those that travel between the stars. More specifically, they looked to see if their calculations could show the degree of decoherence that might occur during such a journey.
With quantum communications, engineers are faced with quantum particles that lose some or all of their unique characteristics as they interact with obstructions in their path—they have been found to be quite delicate, in fact. Such events are known as decoherence, and engineers working to build quantum networks have been devising ways to overcome the problem. Prior research has shown that the space between the stars is pretty clean. But is it clean enough forquantum communications? The math shows that it is. Space is so clean, in fact, that X-ray photons could travel hundreds of thousands of light years without becoming subject to decoherence—and that includes gravitational interference from astrophysical bodies. They noted in their work that optical and microwave bands would work equally well.
The researchers noted that because quantum communication is possible across the galaxy, if other intelligent beings exist in the Milky Way, they could already be trying to communicate with us using such technology and we could begin looking for them. They also suggest that quantum teleportation across interstellar space should be possible.
Arjun Berera et al, Viability of quantum communication across interstellar distances, Physical Review D (2022). DOI: 10.1103/PhysRevD.105.123033
Scientists discover how first quasars in universe formed
The mystery of how the first quasars in the universe formed—something that has baffled scientists for nearly 20 years—has now been solved by a team of astrophysicists whose findings are published in Nature.
The existence of more than 200 quasars powered by supermassive balckholes less than a billion years after the Big Bang had remained one of the outstanding problems in astrophysics because it was never fully understood how they formed so early.
Daniel Whalen et al, Revealing the origin of the first supermassive black holes,Nature(2022). DOI: 10.1038/d41586-022-01560-y ,www.nature.com/articles/d41586-022-01560-y
How a shape-shifting receptor influences cell growth
Receptors found on cell surfaces bind to hormones, proteins, and other molecules, helping cells respond to their environment. MIT chemists have now discovered how one of these receptors changes its shape when it binds to its target, and how those changes trigger cells to grow and proliferate.
This receptor, known as epidermal growth factor receptor (EGFR), is overexpressed in many types of cancer and is the target of several cancer drugs. These drugs often work well at first, but tumors can become resistant to them. Understanding the mechanism of these receptors better may help researchers design drugs that can evade that resistance.
Thinking about more general mechanisms to target EGFR is an exciting new direction, and gives you a new avenue to think about possible therapies that may not evolve resistance as easily.
The EGF receptor is one of many receptors that help control cell growth. Found on most types of mammalian epithelialcells, which line body surfaces and organs, it can respond to several types of growth factors in addition to EGF. Some types of cancer, especially lung cancer and glioblastoma, overexpress the EGF receptor, which can lead to uncontrolled growth.
Like most cellreceptors, the EGFR spans thecell membrane. An extracellular region of the receptor interacts with its target molecule (also called a ligand); a transmembrane section is embedded within themembrane; and an intracellular section interacts with cellular machinery that controls growth pathways.
The extracellular portion of the receptor has been analyzed in detail, but the transmembrane and intracellular sections have been difficult to study because they are more disordered and can't be crystallized.
Dr. Krishna Kumari Challa
Nanoparticle sensor can distinguish between viral and bacterial pne...
Many different types of bacteria and viruses can cause pneumonia, but there is no easy way to determine which microbe is causing a particular patient's illness. This uncertainty makes it harder for doctors to choose effective treatments because the antibiotics commonly used to treat bacterial pneumonia won't help patients with viral pneumonia. In addition, limiting the use of antibiotics is an important step toward curbing antibiotic resistance.
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Bacterial intimacy insights could help tackle antimicrobial resistance
One of the primary ways harmful bacteria acquire resistance to antibiotics is by receiving DNA from other bacteria that are already resistant. This DNA exchange is made via a process called conjugation, akin to bacterial sex, whereby two bacteria form an intimate attachment, and one transfers a packet of DNA to the other.
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Shedding light on how bacteria communicate their way to causing inf...
Oregon State University scientists have identified proteins that prevent a bacterial cell from becoming misguided by its own messaging, allowing it to instead wait for collective communication from its group.
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Polluted air cuts global life expectancy by two years
Microscopic air pollution caused mostly by burning fossil fuels shortens lives worldwide by more than two years, researchers reported Tuesday.
Jun 14, 2022
Dr. Krishna Kumari Challa
Scientists discover and characterize a novel membraneless organelle that could play a role in Alzheimer's treatment
Researchers have discovered a novel organelle—a previously unknown cell structure whose function it is to help clean up faulty proteins in times of stress and keep cells functioning in top condition. Optimizing this membraneless organelle, which they call a BAG2 condensate, could lead to treatments for conditions that are the result of misfolded proteins, including Alzheimer's disease, Parkinson's disease and other neurodegenerative conditions. Their results are reported in a paper and published in the journal Nature Communications.
People have known for quite a while that are a few objects floating around in cells that don't have membranes. And it's never been clear how they're held together, what they are and what they're doing until relatively recently.
Thanks to advanced imaging techniques, scientists have uncovered structures that were once invisible, revealing cells for the truly complex and sophisticated systems that they are.
Of particular interest are biomolecular condensates, which don't have the recognizable cell membrane enclosure, but instead, are separated from the surrounding cytoplasm by a difference in density that can be loosely compared to a drop of oil in water. This liquid-liquid phase separation creates a specialized, relatively concentrated environment for certain functions and reactions. For example, a stress granule is a membraneless organelle that appears when the cell is under stress—maybe there's too much glucose, maybe it's too hot or cold, maybe the cell is experiencing dehydration—and its job is to sweep up RNA floating around in the cytoplasm, storing those genetic instructions and pausing their translation into proteins. If your cell is under stress, you want to shut down making proteins so you can really conserve your energy and get past the stress.
But that's only part of the picture, according to the researchers.
When there's stress, what happens to the proteins that are already in the cell?. If they're under those stress conditions, some of those proteins could get damaged and they could misfold." Misfolds of the tau protein, for example, can become pathological and turn into the neurofibrillary tangles that characterize Alzheimer's disease.
This is where the researchers' newly discovered BAG2 condensate comes in. Named for the BAG2 protein that it contains, the organelle, they found, is capable of sweeping up these faulty proteins in the cytoplasm and stuffing them into a proteasome—the cell's version of a trash can—located in the organelle.
Part 1
Jun 15, 2022
Dr. Krishna Kumari Challa
A few proteins form a little barrel, and as the protein is threaded through that little cylinder, it gets degraded. This inactivates and breaks down the protein. Many proteasomes are present in cells at any given time, he added, but what makes this particular proteasome (labeled 20S) special is that it can accept proteins that are already somewhat misfolded and would not fit in the other cellular trash cans.
The limiting cap present on many proteasomes is not there in the BAG2 condensates. These promising results could point to a way to interrupt the development of Alzheimer's disease, which is marked by an accumulation of misfolded tau.
Daniel C. Carrettiero et al, Stress routes clients to the proteasome via a BAG2 ubiquitin-independent degradation condensate, Nature Communications (2022). DOI: 10.1038/s41467-022-30751-4
Jun 15, 2022
Dr. Krishna Kumari Challa
Shedding light on how bacteria communicate their way to causing infection
Scientists have identified proteins that prevent a bacterial cell from becoming misguided by its own messaging, allowing it to instead wait for collective communication from its group. The research is important because understanding this type of signaling, known as quorum sensing and integral to bacterial pathogens, opens the door to potential new drugs that can disrupt it and thwart infection. Findings were published in the Proceedings of the National Academy of Sciences.
Sometimes single-celled organisms need to work together with other cells. Bacteria and other single-celled microbes can coordinate behaviors and act as a group via quorum sensing, in which cells produce and sense a small chemical signal that is shared within the population. As the signal is released from cells and reaches a high enough concentration in their environment, a quorum is achieved—certain genes are simultaneously activated and specific group behaviors are set in motion.
It's a strength-in-numbers approach that allows bacteria to join forces to do things they could not do by themselves, like causing infection in animals and plants, acquiring certain nutrients and competing against other microbes.
Bacterial infection often involves toxins that only harm the host at high levels, when produced by all bacterial cells at once.
A major unresolved question about quorum sensing, the researchers said, has been why the signal that's produced inside an individual cell is not sensed by that same cell before it is released, spurring the cell into premature, solo action.
What prevents signal 'short-circuiting' from happening? A set of proteins called antiactivators are crucial for short-circuit prevention. The proteins work as a quorum sensing "tuner" by causing cells to be less sensitive to the quorum signal.
This research shows how bacteria put the brakes on quorum sensing to achieve true communication in a group.
In addition to helping the quest for new antibiotics that can inhibit quorum sensing in bacterial pathogens, the findings also provide background knowledge useful for the engineering of cells with new properties in a field called synthetic biology.
Antiactivators prevent self-sensing in quorum sensing, Proceedings of the National Academy of Sciences (2022). DOI: 10.1073/pnas.2201242119.
Jun 15, 2022
Dr. Krishna Kumari Challa
New work upends understanding of how blood is formed
The origins of our blood may not be quite what we thought. Using cellular "barcoding" in mice, a groundbreaking study finds that blood cells originate not from one type of mother cell, but two, with potential implications for blood cancers, bone marrow transplant, and immunology.
Till now people thought that most of our blood comes from a very small number of cells that eventually become blood stem cells, also known as hematopoietic stem cells. Scientists are now surprised to find another group of progenitor cells that do not come from stem cells. They make most of the blood in fetal life until young adulthood, and then gradually start decreasing.
The researchers are now following up to see if the findings also apply to humans. If so, these cells, known as embryonic multipotent progenitor cells (eMPPs), could potentially inform new treatments for boosting aging people's immune systems. They could also shed new light on blood cancers, especially those in children, and help make bone marrow transplants more effective.
Researchers applied a barcoding technique they developed several years ago and documented in Cell. Using either an enzyme known as transposase or CRISPR gene editing, they inserted unique genetic sequences into embryonic mouse cells in such a way that all the cells descended from them also carried those sequences. This enabled the team to track the emergence of all the different types of blood cells and where they came from, all the way to adulthood.
Through barcoding, the researchers found that eMPPs, as compared with blood stem cells, are a more abundant source of most lymphoid cells important to the immune responses, such as B cells and T cells. They think the decrease in eMPPs that they observed with age may explain why people's immunity weakens as they get older.They are now trying to understand why these cells peter out in middle age, which could potentially allow us to manipulate them with the goal of rejuvenating the immune system.
In theory, there could be two approaches: extending the life of eMPP cells, perhaps through growth factors or immune signaling molecules, or treating blood stem cells with gene therapy or other approaches to make them more like eMPPs.
Finally, the recognition that there are two types of mother cells in the blood could revolutionize bone marrow transplant.
Fernando Camargo, Lifelong multilineage contribution by embryonic-born blood progenitors, Nature (2022). DOI: 10.1038/s41586-022-04804-z. www.nature.com/articles/s41586-022-04804-z
Sarah Bowling et al, An Engineered CRISPR-Cas9 Mouse Line for Simultaneous Readout of Lineage Histories and Gene Expression Profiles in Single Cells, Cell (2020). DOI: 10.1016/j.cell.2020.04.048
Jun 16, 2022
Dr. Krishna Kumari Challa
Gender Inclusive Science Communication-Opportunities & Challenges
Jun 16, 2022
Dr. Krishna Kumari Challa
A Common Epilepsy Drug Causes Birth Defects, And We May Finally Know Why
Valproic acid – a drug commonly used to treat epilepsy and bipolar disorder – can cause birth defects and developmental disorders if taken during pregnancy, but the reason why has long been a mystery.
Now, in a study using mice and human tissue, scientists discovered that the medication locks some embryonic cells into a suspended state where they can't properly grow or divide.
By forcing key stem cellss into this state, called senescence, valproic acid may disrupt brain development in the womb and therefore cause cognitive and developmental disorders down the line, according to the study, published Tuesday (June 14) in the journal PLOS Biology.
An estimated 30 to 40 percent of infants exposed to the drug in the womb develop cognitive impairments or autism spectrum disorder, the study authors noted in their report, and these laboratory studies hint at why that happens.
In a subset of affected children, valproic acid exposure can also cause birth defects beyond the brain, including heart malformations and spina bifida, where part of the spinal column doesn't form properly and thus leaves the spinal cord exposed.
However, the new study suggests that these physical birth defects, though also linked to valproic acid, are triggered by a different mechanism than the cognitive impairment.
https://journals.plos.org/plosbiology/article?id=10.1371/journal.pb...
Jun 16, 2022
Dr. Krishna Kumari Challa
Climate change catastrophe: Phytoplankton Productivity Down 65%
Jun 17, 2022
Dr. Krishna Kumari Challa
Which cells are involved in heart repair and how they communicate with each other
Thousands of people suffer heart attacks every year. In this case, the heart muscle is no longer supplied with sufficient blood and oxygen, and part of the heart muscle tissue dies and becomes scarred. The consequences can range from massive cardiac insufficiency to heart failure. Unlike the liver, the heart of an adult human being cannot regenerate. However, it is able to initiate repair processes. Exactly how these repair processes take place has not been known until now. Therefore, there are still no drugs that can specifically promote healing.
Now a research team has found out which cells are involved in heart repair and how they communicate with each other. The researchers have discovered a new messenger substance that controls wound healing, thus revealing an approach for a new therapy. The research has been published in Science.
The focus of the study is the receptor KIT. The protein is produced by various cells, including the hematopoietic stem cells in the bone marrow. Here, KIT plays an important role as a binding site for the so-called stem cell factor. This messenger substance activates the KIT-positive stem cells and causes them to develop into the various cells of the blood. KIT-positive cells are also found in the heart.
"However, these are not stem cells, as long suspected, but vascular cells. The KIT-positive vascular cells ensure that new heart vessels form after a heart attack. However, the stem cell factor necessary for KIT activation can barely be detected in the heart. The researchers have now resolved this contradiction. They discovered a new messenger substance in the heart that can also bind precisely to the KIT receptor and set the repair process in motion: the protein meteorin-like (METRNL).
After a heart attack, the immune system reacts with an inflammatory response . The inflammatory cells produce METRNL, which stimulates the KIT-positive vascular cells to form new blood vessels.
Studies in the mouse model showed that without METRNL, heart repair no longer worked. In contrast, when mice were treated with METRNL, new vessels formed in the infarct area. This alleviates scarring and prevents severe heart failure.
The newly discovered messenger substance could now be the decisive building block to a drug that specifically supports heart repair.
Marc R. Reboll et al, Meteorin-like promotes heart repair through endothelial KIT receptor tyrosine kinase, Science (2022). DOI: 10.1126/science.abn3027
Jun 18, 2022
Dr. Krishna Kumari Challa
Electrons take the fast and slow lanes at the same time
Imagine a road with two lanes in each direction. One lane is for slow cars, and the other is for fast ones. For electrons moving along a quantum wire, researchers have discovered that there are also two "lanes," but electrons can take both at the same time!
Current in a wire is carried by the flow of electrons. When the wire is very narrow (one-dimensional, 1D) then electrons cannot overtake each other, as they strongly repel each other. Current, or energy, is carried instead by waves of compression as one particle pushes on the next.
It has long been known that there are two types of excitation for electrons, as in addition to their charge they have a property called spin. Spin and charge excitations travel at fixed, but different speeds, as predicted by the Tomonaga-Luttinger model many decades ago. However, theorists are unable to calculate what precisely happens beyond only small perturbations, as the interactions are too complex. The Cambridge team has measured these speeds as their energies are varied, and find that a very simple picture emerges (now published in the journal Science Advances). Each type of excitation can have low or high kinetic energy, like cars on a road, with the well-known formula E=1/2 mv2, which is a parabola. But for spin and charge the masses m are different, and, since charges repel and so cannot occupy the same state as another charge, there is twice as wide a range of momentum for charge as for spin. The results measure energy as a function of magnetic field, which is equivalent to momentum or speed v, showing these two energy parabolas, which can be seen in places all the way up to five times the highest energy occupied by electrons in the system.
It's as if the cars (like charges) are traveling in the slow lane but their passengers (like spins) are going more quickly, in the fast lane! Even when the cars and passengers slow down or speed up, they still remain separate!
These results now open the question of whether this spin-charge separation of the whole electron sea remains robust beyond 1D, e.g., in high-temperature superconducting materials. It may also now be applied to logic devices that harness spin (spintronics), which offer a drastic reduction (by three orders of magnitude!) of the energy consumption of a transistor, simultaneously improving our understanding of quantum matter as well as offering a new tool for engineering quantum materials
Pedro M. T. Vianez et al, Observing separate spin and charge Fermi seas in a strongly correlated one-dimensional conductor, Science Advances (2022). DOI: 10.1126/sciadv.abm2781
Jun 18, 2022
Dr. Krishna Kumari Challa
Transplanting kidneys without need for immune-suppressing drugs
Physicians have developed a way to provide pediatric kidney transplants without immune-suppressing drugs. Their key innovation is a safe method to transplant the donor's immune system to the patient before surgeons implant the kidney.
The medical team has named the two-transplant combination a "dual immune/solid organ transplant," or DISOT. A scientific paper describing the first three DISOT cases, all performed at Lucile Packard Children's Hospital Stanford, published online June 15 in the New England Journal of Medicine.
This innovation removes the possibility that the recipient will experience immune rejection of their transplanted organ. (Organ rejection is the most common reason for a second organ transplant.) The new procedure also rids recipients of the substantial side effects of a lifetime of immune-suppressing medications, including increased risks for cancer, diabetes, infections and high blood pressure.
The first three DISOT patients were children with a rare immune disease, but the team is expanding the types of patients who could benefit.
The doctors anticipate that the protocol will eventually be available to many people needing kidney transplants, starting with children and young adults, and later expanding to older adults. The researchers also plan to investigate DISOT's utility for other types of solid-organ transplants.
The scientific innovation from the team has another important benefit: It enables safe transplantation between a donor and recipient whose immune systems are genetically half-matched, meaning children can receive stem cell and kidney donations from a parent.
Part 1
Jun 18, 2022
Dr. Krishna Kumari Challa
The idea of transplanting a patient with their organ donor's immune system has been around for decades, but it has been difficult to implement. Transplants of stem cells from bone marrow provide the patient with a genetically new immune system, as some of the bone marrow stem cells mature into immune cells in the blood. First developed for people with blood cancers, stem cell transplants carry the risk of the new immune cells attacking the recipient's body, a complication called graft-versus-host disease. Severe GVHD can be fatal.
Researchers working with adult patients have performed sequential stem cell and kidney transplants from living donors. When the donor was half-matched they had partial success, but patients were either unable to completely discontinue immune-suppressing drugs after transplant, or—in other trials not conducted at Stanford—they had unacceptably high risks of severe GVHD.
This new work introduced refinements that greatly improve the success of the two-transplant combination with much lower risk. This key innovation is a change in how the donor's stem cells are processed.
https://www.nejm.org/doi/full/10.1056/NEJMoa2117028
After stem cells are removed from the donor's body, technicians perform alpha-beta T cell depletion, which removes the type of immune cells that cause GVHD. Bertaina's team had showed that alpha-beta T cell depletion—which she developed while working in Italy prior to coming to Stanford—makes stem cell transplants safer and enables genetically half-matched transplants. The protocol is relatively gentle, making it safe for children with immune disorders who are too medically fragile for a traditional stem cell transplant. The alpha-beta T cells recover in the patient after 60 to 90 days, meaning they regain full immune function.
Part 2
Jun 18, 2022
Dr. Krishna Kumari Challa
Bluetooth signals can be used to identify and track smartphones
Jun 18, 2022
Dr. Krishna Kumari Challa
Damage to Brain Network Curbs Urge to Smoke
A study finds that injuries to certain areas of the brain were associated with quitting smoking more quickly, easily, and with no cravings.
Astudy of people who effortlessly quit smoking after a stroke or other brain injury—and of those who suffered an injury but then kept smoking—has pinpointed a brain network involved in addiction, researchers reported June 13 in Nature Medicine. Experts say the findings may help identify targets for therapies that could treat addictions.
https://www.the-scientist.com/news-opinion/damage-to-brain-network-...
Jun 18, 2022
Dr. Krishna Kumari Challa
Keeping objects levitated by sound airborne despite interference
A team of researchers has developed a way to keep objects levitated by sound waves airborne when other objects interfere with the levitation path. In their paper published in the journal Science Advances, the group describes their self-correcting levitation system.
Prior research has shown that it is possible to levitate objects by firing sound waves at them. Because sound waves are nothing more than air particles moving together in a certain way, the object being levitated will fall if an object interferes with the sound waves. In this new effort, the researchers developed new features to address this problem.
To protect the sound waves from interference, the researchers increased the number of speakers used—in their work, they used 256. They also added software to control each of the speakers. The speakers were arranged in a grid and objects were levitated by specifically shaped sound waves. By programming the speakers in specific ways, the team was able to get the system to work together to keep an object above the grid in the air despite interruptions. If some of the sound waves were blocked, other sound waves were redirected to take their place.
The researchers proved their system was viable by testing it using a 3D-printed white rabbit as an interference object. Objects were levitated around the rabbit regardless of its location. In one experiment, the researchers levitated beads around the rabbit that formed into a flying butterfly. They also levitated a piece of clear fabric that they used as a screen for projection of the rabbit they had printed. And they levitated a single drop of water over a glass of water, showing that their system would work even when the interfering object was a jiggling glass of liquid.
Ryuji Hirayama et al, High-speed acoustic holography with arbitrary scattering objects, Science Advances (2022). DOI: 10.1126/sciadv.abn7614
Jun 21, 2022
Dr. Krishna Kumari Challa
Lack of diversity of microorganisms in the gut or elevated gut metabolites implicated in heart failure severity
Some people who experience heart failure have less biodiversity in their gut or have elevated gut metabolites, both of which are associated with more hospital visits and greater risk of death, according to a systematic review of research findings.
The gut microbiome is a delicately balanced ecosystem comprised primarily of bacteria as well as viruses, fungi and protozoa. The microbiome can affect cardiovascular disease, which is a leading cause of death in many parts of the world.
For their overview, the investigators looked at seven years of genetic, pharmacologic and other types of research findings from around the world to generate a wide perspective on how the microbiome can influence heart failure. The investigators zeroed in on one harmful metabolite, trimethylamine-N-oxide (TMAO), that can be produced by churning gut microbiota when full-fat dairy products, egg yolks and red meat are consumed.
The Heart and Gut Relationship: A Systematic Review of the Evaluation of the Microbiome and Trimethylamine-N-Oxide (TMAO) in Heart Failure, Heart Failure Reviews (2022). DOI: 10.1007/s10741-022-10254-6
Jun 21, 2022
Dr. Krishna Kumari Challa
Scientists develop antimicrobial, plant-based food wrap designed to replace plastic
Aiming to produce environmentally friendly alternatives to plastic food wrap and containers, a scientist has developed a biodegradable, plant-based coating that can be sprayed on foods, guarding against pathogenic and spoilage microorganisms and transportation damage.
The scalable process could potentially reduce the adverse environmental impact of plastic food packaging as well as protect human health.
Their article, published in the science journal Nature Food, describes the new kind of packaging technology using the polysaccharide/biopolymer-based fibers. Like the webs cast by the Marvel comic book character Spider-Man, the stringy material can be spun from a heating device that resembles a hair dryer and "shrink-wrapped" over foods of various shapes and sizes, such as an avocado or a sirloin steak. The resulting material that encases food products is sturdy enough to protect bruising and contains antimicrobial agents to fight spoilage and pathogenic microorganisms such as E. coli and listeria.
The research paper includes a description of the technology called focused rotary jet spinning, a process by which the biopolymer is produced, and quantitative assessments showing the coating extended the shelf life of avocados by 50 percent. The coating can be rinsed off with water and degrades in soil within three days, according to the study.
The new packaging is targeted at addressing a serious environmental issue: the proliferation of petroleum-based plastic products in the waste stream.
High-throughput coating with biodegradable antimicrobial pullulan fibres extends shelf life and reduces weight loss in an avocado model, Nature Food (2022). DOI: 10.1038/s43016-022-00519-6
Jun 21, 2022
Dr. Krishna Kumari Challa
Scientists transplant human photoreceptors to successfully recover daylight perception in mice
Transplantation of photoreceptor cells is a promising intervention that in the future could help recover vision in people with blinding diseases. A team of researchers developed a robust method to produce high numbers of human photoreceptor cells. The researchers show that such human photoreceptors can incorporate in bulk into partially degenerated mouse retinas. The incorporated photoreceptors developed characteristics of normal photoreceptors and allowed mice with damaged eyesight to detect daylight.
The new study represents a step forward in an effort to bring photoreceptor transplantations to patients with blinding diseases.
To massively increase the number of incorporated photoreceptors, the scientists optimized multiple critical factors. They established that the age of transplanted photoreceptors is decisive.
The team also found that the integration into the retina needs a longer time.
The interaction with the remaining, undamaged cells in the mouse retina turned out to be a key factor. About 30% of the cells in the retina are other cells that support the work of photoreceptors. In this case, researchers clearly saw that the interaction of transplanted cells with host retinal cells was crucial for successful incorporation and maturation. Some of these remaining cells provided a scaffold for the new photoreceptors and helped them organize correctly.
To produce photoreceptors, the team used stem cells to grow mini-retinas in a laboratory dish.
Obtaining a pure population of photoreceptors is yet another challenge. To address it researchers developed a new stem cell line in which cone photoreceptor cells have special tags. These tags do not interfere with their function but allow us to robustly sort photoreceptors from the rest of the cells in the mini-retinas.
Such induced pluripotent stem cell lines provide a virtually unlimited source of photoreceptors and can potentially be used in future clinical applications.
In this study, the team focused on mice with partially degenerated retinas that lacked only one out of two types of photoreceptors. The mice had only damaged cones, which are responsible for daylight vision, a situation similar to several blinding diseases in human patients.
https://www.jci.org/articles/view/154619
Jun 21, 2022
Dr. Krishna Kumari Challa
World's biggest giant bacteria that can be seen without a microscope
These thin vermicelli-like threads are revealed to be single bacterial cells!
The unusual size is notable because bacteria aren't usually visible without the assistance of microscope. It's 5,000 times bigger than most bacteria
For most bacteria, their DNA floats freely within the cytoplasm of their cells. This newly discovered species of bacteria keeps its DNA more organized. "The big surprise of the project was to realize that these genome copies that are spread throughout the whole cell are actually contained within a structure that has a membrane. "And this is very unexpected for a bacterium."
It is a bacterium belonging to the genus Thiomargarita,. Scientists named it Ca. Thiomargarita magnifica.
This is a sulfur-oxidizing, carbon fixing bacterium and are important in mangrove eco systems . They contain membrane-bound compartments that contain DNA clusters . Scientists dubbed these organelles "pepins," The bacteria contain three times more genes than most bacteria and hundreds of thousands of genome copies (polyploidy) that are spread throughout the entire cell.
In terms of metabolism, it does chemosynthesis, which is a process analogous to photosynthesis for plants.
Jean-Marie Volland et al, A centimeter-long bacterium with DNA contained in metabolically active membrane-bound organelles, Science (2022). DOI: 10.1126/science.abb3634. www.science.org/doi/10.1126/science.abb3634
Jun 24, 2022
Dr. Krishna Kumari Challa
Wearable antimicrobial copper nanomesh sticks to human skin, killin...
A team of researchers from the University of Tokyo, the Korea Research Institute of Bioscience and Biotechnology and the Center for Emergent Matter Science & Thin-Film Device Laboratory RIKEN 2-1 Hirosawa has developed a wearable antimicrobial nanomesh material that sticks to human skin, killing microbes nearly instantly. They have published their creation in Proceedings of the National Academy of Sciences.
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Diagnosing jaundice using tear fluids
Human tear fluids contain many proteins, metabolites, and other molecules whose concentrations change significantly with certain diseases. A research team has now developed a handy test kit for tears that can identify patients with jaundice. Their success is based on a hybrid sensor that simultaneously removes impurities from the sample. This approach could provide new methods for early detection and diagnosis based on complex bodily fluids, as the team reported in the journal Angewandte Chemie International Edition.
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How the first biomolecules could have been formed
The chemical precursors of present-day biomolecules could have formed not only in the deep sea at hydrothermal vents, but also in warm ponds on the Earth's surface. The chemical reactions that may have occurred in this "primordial soup" have now been reproduced in experiments by an international team led by researchers of Friedrich Schiller University Jena, Germany. They even found that one of the nucleobases, which represent the code of our genetic material, could have originated from the surface of our planet
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A newly identified stem cell regulator enables lifelong sperm produ...
Unlike women, who are born with all the eggs they'll ever have, men can continue to produce sperm throughout their adult lives. To do so, they require a constant renewal of spermatogonial stem cells, which give rise to sperm.
Jun 24, 2022
Dr. Krishna Kumari Challa
Breast cancer spreads at night
A new study shows that breast cancer metastases form more efficiently while patients are sleeping. This finding could significantly change the way cancer is diagnosed and treated in future.
Breast cancer is one of the most common forms of cancer, according to the World Health Organization (WHO). Each year, around 2.3 million people worldwide contract the disease. If doctors detect breast cancer early enough, patients usually respond well to treatment. However, things become much more difficult if the cancer has already metastasised. Metastasis occurs when circulating cancer cells break away from the original tumour, travel through the body via blood vessels and form new tumours in other organs.
To date, cancer research has not paid much attention to the question of when tumours shed metastatic cells. Researchers previously assumed that tumours release such cells continuously. However, a new study by researchers at ETH Zurich, the University Hospital Basel and the University of Basel has now come to a surprising conclusion: circulating cancer cells that later form metastases mainly arise during the sleep phase of the affected individuals. The results of the study have just been published in the journal Nature.
Circadian rhythm-regulated hormones control metastasis
When the affected person is asleep, the tumour awakens!
The researchers found that the tumour generates more circulating cells when the organism is asleep. Cells that leave the tumour at night also divide more quickly and therefore have a higher potential to form metastases, compared to circulating cells that leave the tumour during the day.
This research shows that the escape of circulating cancer cells from the original tumour is controlled by hormones such as melatonin, which determine our rhythms of day and night.
The study indicates that the time in which tumour or blood samples are taken for diagnosis may influence the findings of oncologists. It was an accidental finding along these lines that first put the researchers on the right track. Some scientists work early in the morning or late in the evening; sometimes they’ll also analyse blood at unusual hours. The scientists were surprised to find that samples taken at different times of the day had very different levels of circulating cancer cells.
Another clue was the surprisingly high number of cancer cells found per unit of blood in mice compared to humans. The reason was that as nocturnal animals, mice sleep during the day, which is when scientists collect most of their samples.
These findings may indicate the need for healthcare professionals to systematically record the time at which they perform biopsies.
The researchers’ next step will be to figure out how these findings can be incorporated into existing cancer treatments to optimise therapies.
Zoi Diamantopoulou, Francesc Castro-Giner, Fabienne Dominique Schwab, Christiane Foerster, Massimo Saini, Selina Budinjas, Karin Strittmatter, Ilona Krol, Bettina Seifert, Viola Heinzelmann-Schwarz, Christian Kurzeder, Christoph Rochlitz, Marcus Vetter, Walter Paul Weber, Nicola Aceto. The metastatic spread of breast cancer accelerates during sleep. Nature, 2022; DOI: 10.1038/s41586-022-04875-y
Jun 24, 2022
Dr. Krishna Kumari Challa
Environmental factors predict risk of death: study
Along with high blood pressure, diabetes, and smoking, environmental factors such as air pollution are highly predictive of people's chances of dying, especially from heart attack and stroke, a new study shows.
the study showed that exposure to above average levels of outdoor air pollution increased risk of death by 20%, and risk of death from cardiovascular disease by 17%.
Using wood- or kerosene-burning stoves, not properly ventilated through a chimney, to cook food or heat the home also increasd overall risk of death (by 23% and 9%) and cardiovascular death risk (by 36% and 19%). Living far from specialty medical clinics and near busy roads also increased risk of death.
Publishing in the journal PLOS ONE online June 24, the findings come from personal and environmental health data collected from 50,045 mostly poor, rural villagers living in the northeast Golestan region of Iran. All study participants were over age 40 and agreed to have their health monitored during annual visits with researchers dating as far back as 2004.
Researchers say their latest investigation not only identifies environmental factors that pose the greatest risk to heart and overall health, but also adds much-needed scientific evidence from people in low- and middle -income countries
Spatial environmental factors predict cardiovascular and all-cause mortality: Results of the SPACE Study, PLoS ONE (2022).
https://medicalxpress.com/news/2022-06-environmental-factors-death....
Jun 25, 2022
Dr. Krishna Kumari Challa
Octopus brain and human brain share the same 'jumping genes'
The octopus is an exceptional organism with an extremely complex brain and cognitive abilities that are unique among invertebrates. So much so that in some ways it has more in common with vertebrates than with invertebrates. The neural and cognitive complexity of these animals could originate from a molecular analogy with the human brain, as discovered by a research paper recently published in BMC Biology.
The research shows that the same "jumping genes" are active both in the human brain and in the brain of two species, Octopus vulgaris, the common octopus, and Octopus bimaculoides, the Californian octopus. This discovery could help us understand the secret of the intelligence of these fascinating organisms.
Sequencing the human genome revealed as early as 2001 that over 45% of it is composed of sequences called transposons, so-called "jumping genes" that, through molecular copy-and-paste or cut-and-paste mechanisms, can "move" from one point to another of an individual's genome, shuffling or duplicating. In most cases, these mobile elements remain silent: they have no visible effects and have lost their ability to move. Some are inactive because they have, over generations, accumulated mutations; others are intact, but blocked by cellular defense mechanisms. From an evolutionary point of view, even these fragments and broken copies of transposons can still be useful, as "raw matter" that evolution can sculpt.
Among these mobile elements, the most relevant are those belonging to the so-called LINE (Long Interspersed Nuclear Elements) family, found in a hundred copies in the human genome and still potentially active. It has been traditionally thought that LINEs' activity was just a vestige of the past, a remnant of the evolutionary processes that involved these mobile elements, but in recent years new evidence emerged showing that their activity is finely regulated in the brain. There are many scientists who believe that LINE transposons are associated with cognitive abilities such as learning and memory: they are particularly active in the hippocampus, the most important structure of our brain for the neural control of learning processes.
The octopus' genome, like ours, is rich in "jumping genes," most of which are inactive. Focusing on the transposons still capable of copy-and-paste, the researchers identified an element of the LINE family in parts of the brain crucial for the cognitive abilities of these animals. The discovery was made possible thanks to next generation sequencing techniques, which were used to analyze the molecular composition of the genes active in the nervous system of the octopus.
The discovery of an element of the LINE family, active in the brain of the two octopuses species, is very significant because it adds support to the idea that these elements have a specific function that goes beyond copy-and-paste.
The brain of the octopus is functionally analogous in many of its characteristics to that of mammals. For this reason, also, the identified LINE element represents a very interesting candidate to study to improve our knowledge on the evolution of intelligence.
“Identification of LINE retrotransposons and long non-coding RNAs expressed in the octopus brain” by Giuseppe Petrosino, Giovanna Ponte, Massimiliano Volpe, Ilaria Zarrella, Federico Ansaloni, Concetta Langella, Giulia Di Cristina, Sara Finaurini, Monia T. Russo, Swaraj Basu, Francesco Musacchia, Filomena Ristoratore, Dinko Pavlinic, Vladimir Benes, Maria I. Ferrante, Caroline Albertin, Oleg Simakov, Stefano Gustincich, Graziano Fiorito and Remo Sanges, 18 May 2022, BMC Biology.
DOI: 10.1186/s12915-022-01303-5
Jun 27, 2022
Dr. Krishna Kumari Challa
Monkeypox found to be evolving at a faster rate than expected
A team of researchers has found that the monkeypox virus has been evolving at a faster rate than expected. In their paper published in the journal Nature Medicine, the researchers describe their genetic study of the virus collected from 15 samples
Monkeypox is a double-stranded DNA virus from the same genus as smallpox, and it mostly infects people in Africa. Scientist have known of its existence since the 1950s. Despite its name, the virus is more commonly found in rodents than monkeys. Prior research has shown that there are two main varieties of monkeypox: West African and Congo Basin—the former is far less deadly and is the clade that has infected several thousand people outside Africa. Prior research has also shown that viruses like monkeypox typically only mutate once or twice in a given year.
In this new effort, the researchers collected samples from 15 patients and subjected them to genetic analysis to learn more about how quickly the virus is evolving. They found the virus has mutated at a rate six to 12 times as high as was expected. The researchers suggest the sudden accelerated rate of mutation in the virus may be a sign that the virus has developed a new way to infect people—currently, it is believed to move from person to person through close contact with open lesions, through body fluids or by airborne droplets.
Joana Isidro et al, Phylogenomic characterization and signs of microevolution in the 2022 multi-country outbreak of monkeypox virus, Nature Medicine (2022). DOI: 10.1038/s41591-022-01907-y
In studying the mutations, the researchers found signs suggesting that some of the mutations may have been due to exposure to the human immune system, most particularly enzymes of a type called APOBEC3—they kill viruses by inciting mistakes during copying of genetic code. If some of the viruses survived such an attack and passed on their genes, they would have given future generations a leg up against the human immune system. And that could explain why the virus has been mutating more rapidly than expected. The researchers also note that the virus may have been circulating at low levels in human communities or spreading among animals in other countries. They also note that the accelerated rate of evolution could be a response to the crackdown that ensued during the monkeypox outbreak in 2017.
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Jun 28, 2022
Dr. Krishna Kumari Challa
Virus discovery offers clues about origins of complex life
The first discovery of viruses infecting a group of microbes that may include the ancestors of all complex life has been found, researchers report in Nature Microbiology. The discovery offers tantalizing clues about the origins of complex life and suggests new directions for exploring the hypothesis that viruses were essential to the evolution of humans and other complex life forms.
There is a well-supported hypothesis that all complex life forms such as humans, starfish and trees—which feature cells with a nucleus and are called eukaryotes—originated when archaea and bacteria merged to form a hybrid organism. Recent research suggests the first eukaryotes are direct descendants of so-called A.... The latest research sheds light on how viruses, too, might have played a role in this billions-year-old history.
This study is opening a door to better resolving the origin of eukaryotes and understanding the role of viruses in the ecology and evolution of Asgard archaea. There is a hypothesis that viruses may have contributed to the emergence of complex cellular life.
There is a hypothesis called viral eukaryogenesis. It suggests that, in addition to bacteria and archaea, viruses might have contributed some genetic component to the development of eukaryotes. This latest discovery does not settle that debate, but it does offer some interesting clues.
Part1
Jun 28, 2022
Dr. Krishna Kumari Challa
The newly discovered viruses that infect currently living Asgard archaea do have some features similar to viruses that infect eukaryotes, including the ability to copy their own DNA and hijack protein modification systems of their hosts. The fact that these recovered Asgard viruses display characteristics of both viruses that infect eukaryotes and prokaryotes, which have cells without a nucleus, makes them unique since they are not exactly like those that infect other archaea or complex life forms.
The most exciting thing is they are completely new types of viruses that are different from those that we've seen before in archaea and eukaryotes, infecting our microbial relatives.
The Asgard archaea, which probably evolved more than 2 billion years ago and whose descendents are still living, have been discovered in deep sea sediments and hot springs around the world, but so far only one strain has been successfully grown in the lab. To identify them, scientists collect their genetic material from the environment and then piece together their genomes. In this latest study, the researchers scanned the Asgard genomes for repeating DNA regions known as CRISPR arrays, which contain small pieces of viral DNA that can be precisely matched to viruses that previously infected these microbes. These genetic "fingerprints" allowed them to identify these stealthy viral invaders that infect organisms with key roles in the complex origin story of eukaryotes.
We are now starting to understand the implication and role that viruses could have had in the eukaryogenesis puzzle.
Brett Baker, Genomes of six viruses that infect Asgard archaea from deep-sea sediments, Nature Microbiology (2022). DOI: 10.1038/s41564-022-01150-8. www.nature.com/articles/s41564-022-01150-8
Part 2
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Jun 28, 2022
Dr. Krishna Kumari Challa
Oceans saved us, now we can return the favour
Humanity must heal oceans made sick by climate change, pollution and overfishing in order to rescue marine life and save ourselves, experts warned ahead of a major UN conference.
By absorbing—decade after decade—a quarter of CO2 pollution and more than 90 percent of excess heat from global warming, oceans have kept Earth's terrestrial surface liveable.
Our species has returned the favor by dumping mountains of plastic waste into the sea, emptying the deep blue of big fish, and poisoning coastlines with toxic chemicals and agricultural runoff that create dead zones bereft of oxygen.
"If we don't do the right things now, we might end up with a dead oceans”
Jun 28, 2022
Dr. Krishna Kumari Challa
Functional connections between different brain networks can predict a person's age
Neuroscientists have been trying to understand for decades how the human brain changes over the lifespan. This could ultimately help to devise more effective treatments for neurological and cognitive disorders primarily observed in the elderly.
Researchers have recently carried out a study investigating the relationship between age and the functional coupling between specific neural networks in the brain. Their paper, published in Psychology and Aging, shows that the connectivity between certain brain regions can predict people's chronological age with a high level of accuracy.
The differences in cognitive functioning among people of different ages are well documented. The idea that these differences are associated with changes in brain connectivity (i.e., the way in which brain regions and networks communicate with each other) was introduced and discussed in many neuroscience papers.
The present one deals with the Q:Can we use patterns of brain connectivity when people are not doing any tasks to predict their age?
Scientists analyzed data collected from a large cohort of 547 participants between 18 and 88 years old, part of a publicly available brain imaging dataset compiled by the Cambridge Centre for Aging and Neuroscience (CamCAN). By analyzing these data, they firstly investigated whether connectivity between the executive control network (ECN) and default mode network (DMN) regions in the brain can predict age.
To do this, they used a well-established statistical technique called multiple regression analysis. They further examined how connectivity between ECN, DMN, and another region, the salience network (SN)—which is thought to mitigate how ECN and DMN regions talk to each other—impacts the strength of the connections between ECN and DMN areas.
Part 1
Jun 29, 2022
Dr. Krishna Kumari Challa
The analyses carried out now yielded many interesting findings. Most notably, the results showed that the functional connectivity between large-scale brain networks can predict age with good accuracy and that it varies across the lifespan. More specifically, they found that the connectivity between ECN and DMN brain regions accounts for a significant portion of age variability.
Interestingly, the researchers found that when they also included the SN (a set of brain regions that selects salient external or internal stimuli for the brain to focus its attention on) in their analyses, they could predict a person's age with even greater accuracy. In the future, their work could help to better understand the brain connectivity patterns associated with the decline in cognitive abilities observed in older age.
Evangelia G. Chrysikou et al, Large-scale network connectivity as a predictor of age: Evidence across the adult lifespan from the Cam-CAN data set, Psychology and Aging (2022). DOI: 10.1037/pag0000683
Part 2
Jun 29, 2022
Dr. Krishna Kumari Challa
Bacteria's shapeshifting behaviour clue to new treatments for urinary tract infections
Urinary tract infections are both very common and potentially very dangerous. Thousands of women suffer from a UTI in their lifetime, and most of these women will have an infection requiring treatment with antibiotics.
Around 80 percent of UTIs are caused by uropathogenic E. coli (UPEC), which is increasingly resistant to antibiotics. E. coli-related death due to antimicrobial resistance is the leading cause of bacterial fatalities worldwide.
In a bid to aid discovery of new treatment options, researchers are using state-of-the-art microscopy to pinpoint how these bacteria spread and multiply.
The latest research examined the shapeshifting behavior of UPEC. During a UTI infection cycle, the bacteria form spaghetti-like filaments hundreds of times their normal lengths before reverting to their original form.
The study, which is published in Nature Communications, used a human bladder cell infection model to generate the filaments, and look at their reversal back to rod shape.
While we don't fully understand why they do this extreme lifestyle make-over, we know they must revert to their original size before they can reinfect new bladder cells.
Researchers used advanced microscopy to follow two key cell division proteins and their localisation dynamics during reversal. We found that the normal rules for regulation of cell division in bacteria does not fully apply in filaments.
By giving the first clues into how the reversal of filamentation is regulated during infection, scientists may be laying the foundation for identifying new ways to combat UTIs.
The long filaments formed by the bacteria appeared to break open the infected human cells, through a previously unknown mechanism called infection-related filamentation (IRF).
The devastating eruption of these bacteria from the cells of the bladder that they invade probably contributes to the extensive damage and pain experienced during a UTI.
If scientists identify why and how the bacteria shifts their shapes this enables alternative treatments or preventions.
Bill Söderström et al, Assembly dynamics of FtsZ and DamX during infection-related filamentation and division in uropathogenic E. coli, Nature Communications (2022). DOI: 10.1038/s41467-022-31378-1
Jun 29, 2022
Dr. Krishna Kumari Challa
Life in the Earth's interior is as productive as in some ocean waters
Terrestrial and marine habitats have been considered the ecosystems with the highest primary production on Earth by far. Microscopic algae in the upper layers of the oceans and plants on land bind atmospheric carbon (CO2) and produce plant material driven by photosynthesis. Since sunlight does not penetrate into the subsurface, hardly any such primary production is to be expected.
However, genetic analyses of microorganisms in groundwater have indicated that even here many microorganisms are capable of primary production. In the absence of light, they must obtain the energy from oxidizing inorganic compounds, like from reduced sulfur of the surrounding rocks. However, the role of primary producers in the subsurface had never been confirmed before.
Groundwater is one of our most important sources of clean drinking water. The groundwater environment of the carbonate aquifers alone, which is the focus of the study, provides about ten percent of the world's drinking water. With this in mind, the researchers carried out measurements of microbial microorganism carbon fixation in a subsurface aquifer, 5 to 90 meters belowground.
Based on the measured carbon fixation rates, the researchers conservatively extrapolated global primary production in carbonate groundwater to be 110 million metric tons of carbon per year. Collectively, the net primary productivity of approximately 66 percent of the planet's groundwater reservoirs would total 260 million metric tons of carbon per year, which is approximately 0.5 percent that of marine systems and 0.25 percent of global net primary production estimates.
Since there is very little energy available in these nutrient-poor and permanently dark habitats, even a small percentage of the global primary production is a surprise.
The researchers also sought to identify the microorganisms responsible for fixing carbon and generating new biomass within the aquifer. Metagenomic analyses point to a highly abundant microorganism not closely related to previously studied bacteria, within an uncharacterized order of Nitrospiria. As food, these organisms are thought to form the basis of life for the entire groundwater ecosystem with all of its thousands of microbial species, similar to the role algae play in the oceans or plants on land.
Kirsten Küsel, Carbon fixation rates in groundwater similar to those in oligotrophic marine systems, Nature Geoscience (2022). DOI: 10.1038/s41561-022-00968-5. www.nature.com/articles/s41561-022-00968-5
Jun 30, 2022
Dr. Krishna Kumari Challa
First known case of COVID from a cat
Scientists in Thailand have established that a cat passed SARS-CoV-2 to a veterinary surgeon. Given the scale of the pandemic and the close contact between cats and people, some researchers are not surprised. But establishing the direction of viral spread — from cat to person or from person to cat — is tricky. In this case, a cat belonging to a COVID-19-positive family sneezed in the face o.... Such cases of cat-to-human transmission are probably rare, and researchers emphasize that people should care for their cats — and perhaps take extra precautions when handling cats that might be infected — and not abandon them.
Reference: Emerging Infectious Diseases paper
Jun 30, 2022
Dr. Krishna Kumari Challa
Tearless onions
How are they created and do they actually work?
Slicing through an onion damages cells, causing enzymes and other substances that are normally kept apart to spill out and react together. In standard onions the result is a sulphur-containing chemical called syn-propanethial-S-oxide, which resembles tear gas. This forms an irritating acid when it comes into contact with water in your eyes.
Some research groups have created onions that are genetically modified to lack an enzyme that leads to syn-propanethial-S-oxide, but these have not yet made it to market.
The tearless onions – Sunions – now in shops were created by repeatedly cross-breeding milder varieties containing lower levels of pyruvate. This substance is a by-product of the same reaction that forms syn-propanethial-S-oxide and also has a good measure of pungency.
Jun 30, 2022
Dr. Krishna Kumari Challa
Turning methane into methanol under ambient conditions using light
An international team of researchers has developed a fast and economical method of converting methane, or natural gas, into liquid methanol at ambient temperature and pressure. The method takes place under continuous flow over a photo-catalytic material using visible light to drive the conversion.
To help observe how the process works and how selective it is, the researchers used neutron scattering at the VISION instrument at Oak Ridge National Laboratory's Spallation Neutron Source.
The method involves a continuous flow of methane/oxygen-saturated water over a novel metal-organic framework (MOF) catalyst. The MOF is porous and contains different components that each have a role in absorbing light, transferring electrons and activating and bringing together methane and oxygen. The liquid methanol is easily extracted from the water. Such a process has commonly been considered "a holy grail of catalysis" and is an area of focus for research supported by the U.S. Department of Energy. Details of the team's findings, titled "Direct photo-oxidation of methane to methanol over a mono-iron hydroxyl site," are published in Nature Materials.
Sihai Yang, Direct photo-oxidation of methane to methanol over a mono-iron hydroxyl site, Nature Materials (2022). DOI: 10.1038/s41563-022-01279-1. www.nature.com/articles/s41563-022-01279-1
Jul 1, 2022
Dr. Krishna Kumari Challa
Scientists discover norovirus and other 'stomach viruses' can spread through saliva
A class of viruses known to cause severe diarrheal diseases—including the one famous for widespread outbreaks on cruise ships—can grow in the salivary glands of mice and spread through their saliva, scientists have discovered. The findings show that a new route of transmission exists for these common viruses, which afflict billions of people each year worldwide and can be deadly.
The transmission of these so-called enteric viruses through saliva suggests that coughing, talking, sneezing, sharing food and utensils, and even kissing all have the potential for spreading the viruses. The new findings still need to be confirmed in human studies.
The findings, which appear in the journal Nature, could lead to better ways to prevent, diagnose, and treat diseases caused by these viruses, potentially saving lives.
Researchers have known for some time that enteric viruses, such as noroviruses and rotaviruses, can spread by eating food or drinking liquids contaminated with fecal matter containing these viruses. Enteric viruses were thought to bypass the salivary gland and target the intestines, exiting later through feces. Although some scientists have suspected there may be another route of transmission, this theory remained largely untested until now.
Now researchers will need to confirm that salivary transmission of enteric viruses is possible in humans. If they find that it is, the researchers said, they may also discover that this route of transmission is even more common than the conventional route. A finding such as that could help explain, they said, why the high number of enteric virus infections each year worldwide fails to adequately account for fecal contamination as the sole transmission route.
https://www.mlo-online.com/disease/infectious-disease/article/21272...
https://researchnews.cc/news/14014/Scientists-discover-norovirus-an...
Jul 1, 2022
Dr. Krishna Kumari Challa
Asynchronous Reality — where everything remains real except the flow of time
Jul 1, 2022
Dr. Krishna Kumari Challa
A new COVID-19 antibody detection method that does not require a blood sample
A key challenge in limiting the spread of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is identifying infected individuals. Now, investigators have developed a new antibody-based method for the rapid and reliable detection of SARS-CoV-2 that does not require a blood sample.
The ineffective identification of SARS-CoV-2-infected individuals has severely limited the global response to the COVID-19 pandemic, and the high rate of asymptomatic infections (16%–38%) has exacerbated this situation. The predominant detection method to date collects samples by swabbing the nose and throat. However, the application of this method is limited by its long detection time (4–6 hours), high cost, and requirement for specialized equipment and medical personnel, particularly in resource-limited countries.
An alternative and complementary method for the confirmation of COVID-19 infection involves the detection of SARS-CoV-2-specific antibodies. Testing strips based on gold nanoparticles are currently in widespread use for point-of-care testing in many countries. They produce sensitive and reliable results within 10–20 minutes, but they require blood samples collected via a finger prick using a lancing device. This is painful and increases the risk of infection or cross-contamination, and the used kit components present a potential biohazard risk.
To develop a minimally invasive detection assay that would avoid these drawbacks, researchers explored the idea of sampling and testing the interstitial fluid (ISF), which is located in the epidermis and dermis layers of human skin. Although the antibody levels in the ISF are approximately 15%–25% of those in blood, it was still feasible that anti-SARS-CoV-2 IgM/IgG antibodies could be detected and that ISF could act as a direct substitute for blood sampling."
After demonstrating that ISF could be suitable for antibody detection, the researchers developed an innovative approach to both sample and test the ISF. They first developed biodegradable porous microneedles made of polylactic acid that draws up the ISF from human skin.
Then, they constructed a paper-based immunoassay biosensor for the detection of SARS-CoV-2-specific antibodies. By integrating these two elements, the researchers created a compact patch capable of on-site detection of the antibodies within 3 minutes (result from in vitro tests).
This novel detection device has great potential that is safe and acceptable to patients for the rapid screening of COVID-19 and many other infectious diseases. It holds promise for use in many countries regardless of their wealth, which is a key aim for the global management of infectious disease.
Anti SARS CoV 2 IgM/IgG antibodies detection using a patch sensor containing porous microneedles and a paper based immunoassay, Scientific Reports (2022). DOI: 10.1038/s41598-022-14725-6
Jul 2, 2022
Dr. Krishna Kumari Challa
Could carbon monoxide foam help fight inflammation?
Carbon monoxide is best known as a potentially deadly gas. However, in small doses it also has beneficial qualities: It has been shown to reduce inflammation and can help stimulate tissue regeneration.
We’ve known for years that carbon monoxide can impart beneficial effects in all sorts of disease pathologies, when given as an inhaled gas. However, it’s been a challenge to use it in the clinic, for a number of reasons related to safe and reproducible administration, and health care workers’ concerns, which has led to people wanting to find other ways to administer it.
A team of researchers has now devised a novel way to deliver carbon monoxide to the body while bypassing its potentially hazardous effects. Inspired by techniques used in molecular gastronomy, they were able to incorporate carbon monoxide into stable foams that can be delivered to the digestive tract.
In a study of mice, the researchers showed that these foams reduced inflammation of the colon and helped to reverse acute liver failure caused by acetaminophen overdose. The new technique, described earlier this week in a Science Translational Medicine paper, could also be used to deliver other therapeutic gases, the researchers say.
The ability to deliver a gas opens up whole new opportunities of how we think of therapeutics. We generally don’t think of a gas as a therapeutic that you would take orally (or that could be administered rectally), so this offers an exciting new way to think about how we can help patients.
Since the late 1990s, researchers have been studying the therapeutic effects of low doses of carbon monoxide. The gas has been shown to impart beneficial effects in preventing rejection of transplanted organs, reducing tumor growth, and modulating inflammation and acute tissue injury.
When inhaled at high concentrations, carbon monoxide binds to hemoglobin in the blood and prevents the body from obtaining enough oxygen, which can lead to serious health effects and even death. However, at lower doses, it has beneficial effects such as reducing inflammation and promoting tissue regeneration.
To tackle the challenge of delivering a gas, researchers came up with the idea of incorporating the gas into a foam, much the way that chefs use carbon dioxide to create foams infused with fruits, vegetables, or other flavours.
Part 1
Jul 2, 2022
Dr. Krishna Kumari Challa
Culinary foams are usually created by adding a thickening or gelling agent to a liquid or a solid that has been pureed, and then either whipping it to incorporate air or using a specialized siphon that injects gases such as carbon dioxide or compressed air.
The team created a modified siphon that could be attached to any kind of gas cannister, allowing them to incorporate carbon monoxide into their foam. To create the foams, they used food additives such as alginate, methyl cellulose, and maltodextrin. Xantham gum was also added to stabilize the foams. By varying the amount of xantham gum, the researchers could control how long it would take for the gas to be released once the foams were administered.
After showing that they could control the timing of the gas release in the body, the researchers decided to test the foams for a few different applications. First, they studied two types of topical applications, analogous to applying a cream to soothe itchy or inflamed areas. In a study of mice, they found that delivering the foam rectally reduced inflammation caused by colitis or radiation-induced proctitis (inflammation of the rectum that can be caused by radiation treatment for cervical or prostate cancer).
Current treatments for colitis and other inflammatory conditions such as Crohn’s disease usually involve drugs that suppress the immune system, which can make patients more susceptible to infections. Treating those conditions with a foam that can be applied directly to inflamed tissue offers a potential alternative, or complementary approach, to those immunosuppressive treatments, the researchers say. While the foams were given rectally in this study, it could also be possible to deliver them orally, the researchers say.
https://news.mit.edu/2022/carbon-monoxide-foam-inflammation-0629
Part2
Jul 2, 2022
Dr. Krishna Kumari Challa
Blood pressure e-tattoo promises continuous monitoring
Jul 2, 2022
Dr. Krishna Kumari Challa
100 Fun Facts collected from Google's "i'm feeling curious" feature
Jul 2, 2022
Dr. Krishna Kumari Challa
Study explores coevolution of mammals and their lice
According to a new study, the first louse to take up residence on a mammalian host likely started out as a parasite of birds. That host-jumping event tens of millions of years ago began the long association between mammals and lice, setting the stage for their coevolution and offering more opportunities for the lice to spread to other mammals.
Reported in the journal Nature Ecology and Evolution, the study compared the genomes and family trees of lice and their mammalian hosts. The effort revealed that the two trees share a lot of parallel branches and twigs. Those branching points—where one group of mammals began diverging into new forms—often were echoed in the genomes of the lice that parasitized those mammals, the researchers reported.
In this paper, researchers used data from genome sequencing to show that a major newly recognized group of mammalian lice, including lice of humans, originated on the common ancestor of Afrotheria, a group of mammals primarily of African distribution that includes elephants, hyraxes and elephant shrews, among others. These lice then went on to colonize other major groups of mammals through the process of host switching.
Lice fall into two groups based on their eating habits. Chewing lice munch on skin or secretions, while sucking lice pierce the skin to consume the blood of their hosts. Both types feed on mammals, but sucking lice are exclusive to mammals.
Recent genomic studies revealed that sucking lice are closely related to two groups of chewing lice that also feed on mammals, and "each of the major groups within this newly identified lineage occurs on at least one member of Afrotheria.
Kevin Johnson, Phylogenomics reveals the origin of mammal lice out of Afrotheria, Nature Ecology & Evolution (2022). DOI: 10.1038/s41559-022-01803-1. www.nature.com/articles/s41559-022-01803-1
Jul 5, 2022
Dr. Krishna Kumari Challa
8,000 kilometers per second: Star with the shortest orbital period around black hole discovered
Researchers have discovered the fastest known star, which travels around a black hole in record time. The star, S4716, orbits Sagittarius A*, the black hole in the center of our Milky Way, in four years and reaches a speed of around 8,000 kilometers per second. S4716 comes as close as 100 AU (astronomical unit) to the black hole—a small distance by astronomical standards. One AU corresponds to 149,597,870 kilometers. The study has been published in The Astrophysical Journal.
Florian Peißker et al, Observation of S4716—a Star with a 4 yr Orbit around Sgr A*, The Astrophysical Journal (2022). DOI: 10.3847/1538-4357/ac752f
Jul 6, 2022
Dr. Krishna Kumari Challa
LHCb discovers three new exotic particles: the pentaquark and the first-ever pair of tetraquarks
The international LHCb collaboration at the Large Hadron Collider (LHC) has observed three never-before-seen particles: a new kind of pentaquark and the first-ever pair of tetraquarks, which includes a new type of tetraquark. The findings, presented recently at a CERN seminar, add three new exotic members to the growing list of new hadrons found at the LHC. They will help physicists better understand how quarks bind together into these composite particles.
Quarks are elementary particles and come in six flavors: up, down, charm, strange, top and bottom. They usually combine together in groups of twos and threes to form hadrons such as the protons and neutrons that make up atomic nuclei. More rarely, however, they can also combine into four-quark and five-quark particles, or "tetraquarks" and "pentaquarks." These exotic hadrons were predicted by theorists at the same time as conventional hadrons, about six decades ago, but only relatively recently, in the past 20 years, have they been observed by LHCb and other experiments.
Most of the exotic hadrons discovered in the past two decades are tetraquarks or pentaquarks containing a charm quark and a charm antiquark, with the remaining two or three quarks being an up, down or strange quark or their antiquarks. But in the past two years, LHCb has discovered different kinds of exotic hadrons. Two years ago, the collaboration discovered a tetraquark made up of two charm quarks and two charm antiquarks, and two "open-charm" tetraquarks consisting of a charm antiquark, an up quark, a down quark and a strange antiquark. And last year it found the first-ever instance of a "double open-charm" tetraquark with two charm quarks and an up and a down antiquark. Open charm means that the particle contains a charm quark without an equivalent antiquark.
The discoveries announced now by the LHCb collaboration include new kinds of exotic hadrons. The first kind, observed in an analysis of "decays" of negatively charged B mesons, is a pentaquark made up of a charm quark and a charm antiquark and an up, a down and a strange quark. It is the first pentaquark found to contain a strange quark. The finding has a whopping statistical significance of 15 standard deviations, far beyond the 5 standard deviations that are required to claim the observation of a particle in particle physics.
The second kind is a doubly electrically charged tetraquark. It is an open-charm tetraquark composed of a charm quark, a strange antiquark, and an up quark and a down antiquark, and it was spotted together with its neutral counterpart in a joint analysis of decays of positively charged and neutral B mesons. The new tetraquarks, observed with a statistical significance of 6.5 (doubly charged particle) and 8 (neutral particle) standard deviations, represent the first time a pair of tetraquarks has been observed.
https://lhcb-outreach.web.cern.ch/2022/07/05/observation-of-a-stran...
Jul 6, 2022
Dr. Krishna Kumari Challa
Defining the Anthropocene: Radioactive traces in ocean materials mark the start of the modern age
For the first time, researchers can offer a strong quantitative definition for the start of what is known as the Anthropocene, thanks to traces of radioactive material in marine sediments and corals. The Anthropocene period is considered important by researchers in many fields as it effectively marks a milestone for humanity's impact on Earth's environment and ecosystem.
Researchers combined records of nuclear fallout from atomic tests present in ocean sediments and coral skeletons. These records show a clear change in the ocean environment before, during and after a period of worldwide atomic testing, which the researchers have defined as marking the beginning of the Anthropocene.
Yusuke Yokoyama et al, Plutonium isotopes in the North Western Pacific sediments coupled with radiocarbon in corals recording precise timing of the Anthropocene, Scientific Reports (2022). DOI: 10.1038/s41598-022-14179-w
Jul 6, 2022
Dr. Krishna Kumari Challa
Scientists unravel the key to colon cancer relapse after chemotherapy
Approximately 1 in 25 people will develop colon cancer during their lifetime and nearly 2 million cases new cases are diagnosed worldwide each year. Chemotherapy is commonly used to treat colon cancer. While this treatment is initially effective in most cases, many patients relapse after treatment.
This study reveals that some tumor cells remain in a latent state and, after chemotherapy, they are reactivated, thus causing relapse. Their study is published in Nature Cancer.
In short, scientists have discovered that tumor stem cells with Mex3a protein activity remain in a state of latency that confers resistance to chemotherapy. Due to the action of the drugs used in this treatment, these cells adopt a state similar to the embryonic one, and sometime after chemotherapy, when the environment is more favorable, they are reactivated to regenerate the tumor in all its complexity. These persistent cells are responsible for cancer relapse after treatment.
https://www.nature.com/articles/s43018-022-00402-0
Jul 6, 2022
Dr. Krishna Kumari Challa
Physicists see electron whirlpools for the first time
Though they are discrete particles, water molecules flow collectively as liquids, producing streams, waves, whirlpools, and other classic fluid phenomena.
Not so with electricity. While an electric current is also a construct of distinct particles—in this case, electrons—the particles are so small that any collective behavior among them is drowned out by larger influences as electrons pass through ordinary metals. But, in certain materials and under specific conditions, such effects fade away, and electrons can directly influence each other. In these instances, electrons can flow collectively like a fluid.
Now, physicists have observed electrons flowing in vortices, or whirlpools—a hallmark of fluid flow that theorists predicted electrons should exhibit, but that has never been seen until now.
It's a clear signature where electrons behave as a fluid, not as individual particles.
The observations, reported in the journal Nature, could inform the design of more efficient electronics.
When electrons go in a fluid state, [energy] dissipation drops, and that's of interest in trying to design low-power electronics. This new observation is another step in that direction.
Eli Zeldov, Direct observation of vortices in an electron fluid, Nature (2022). DOI: 10.1038/s41586-022-04794-y. www.nature.com/articles/s41586-022-04794-y
Jul 7, 2022
Dr. Krishna Kumari Challa
Mathematical calculations show that quantum communication across interstellar space should be possible
A team of physicists has used mathematical calculations to show that quantum communications across interstellar space should be possible. In their paper published in the journal Physical Review D, the group describes their calculations and also the possibility of extraterrestrial beings attempting to communicate with us using such signaling.
Over the past several years, scientists have been investigating the possibility of using quantum communications as a highly secure form of message transmission. Prior research has shown that it would be nearly impossible to intercept such messages without detection. In this new effort, the researchers wondered if similar types of communications might be possible across interstellar space. To find out, they used math that describes that movement of X-rays across a medium, such as those that travel between the stars. More specifically, they looked to see if their calculations could show the degree of decoherence that might occur during such a journey.
With quantum communications, engineers are faced with quantum particles that lose some or all of their unique characteristics as they interact with obstructions in their path—they have been found to be quite delicate, in fact. Such events are known as decoherence, and engineers working to build quantum networks have been devising ways to overcome the problem. Prior research has shown that the space between the stars is pretty clean. But is it clean enough for quantum communications? The math shows that it is. Space is so clean, in fact, that X-ray photons could travel hundreds of thousands of light years without becoming subject to decoherence—and that includes gravitational interference from astrophysical bodies. They noted in their work that optical and microwave bands would work equally well.
The researchers noted that because quantum communication is possible across the galaxy, if other intelligent beings exist in the Milky Way, they could already be trying to communicate with us using such technology and we could begin looking for them. They also suggest that quantum teleportation across interstellar space should be possible.
Arjun Berera et al, Viability of quantum communication across interstellar distances, Physical Review D (2022). DOI: 10.1103/PhysRevD.105.123033
Jul 7, 2022
Dr. Krishna Kumari Challa
Scientists discover how first quasars in universe formed
The mystery of how the first quasars in the universe formed—something that has baffled scientists for nearly 20 years—has now been solved by a team of astrophysicists whose findings are published in Nature.
The existence of more than 200 quasars powered by supermassive balckholes less than a billion years after the Big Bang had remained one of the outstanding problems in astrophysics because it was never fully understood how they formed so early.
Daniel Whalen, Turbulent cold flows gave birth to the first quasars, Nature (2022). DOI: 10.1038/s41586-022-04813-y. www.nature.com/articles/s41586-022-04813-y
Daniel Whalen et al, Revealing the origin of the first supermassive black holes, Nature (2022). DOI: 10.1038/d41586-022-01560-y , www.nature.com/articles/d41586-022-01560-y
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Jul 7, 2022
Dr. Krishna Kumari Challa
How a shape-shifting receptor influences cell growth
Receptors found on cell surfaces bind to hormones, proteins, and other molecules, helping cells respond to their environment. MIT chemists have now discovered how one of these receptors changes its shape when it binds to its target, and how those changes trigger cells to grow and proliferate.
This receptor, known as epidermal growth factor receptor (EGFR), is overexpressed in many types of cancer and is the target of several cancer drugs. These drugs often work well at first, but tumors can become resistant to them. Understanding the mechanism of these receptors better may help researchers design drugs that can evade that resistance.
Thinking about more general mechanisms to target EGFR is an exciting new direction, and gives you a new avenue to think about possible therapies that may not evolve resistance as easily.
The EGF receptor is one of many receptors that help control cell growth. Found on most types of mammalian epithelial cells, which line body surfaces and organs, it can respond to several types of growth factors in addition to EGF. Some types of cancer, especially lung cancer and glioblastoma, overexpress the EGF receptor, which can lead to uncontrolled growth.
Like most cell receptors, the EGFR spans the cell membrane. An extracellular region of the receptor interacts with its target molecule (also called a ligand); a transmembrane section is embedded within the membrane; and an intracellular section interacts with cellular machinery that controls growth pathways.
The extracellular portion of the receptor has been analyzed in detail, but the transmembrane and intracellular sections have been difficult to study because they are more disordered and can't be crystallized.
Part 1
Jul 7, 2022