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Comment by Dr. Krishna Kumari Challa on Friday

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.

Comment by Dr. Krishna Kumari Challa on Friday

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

Comment by Dr. Krishna Kumari Challa on June 21, 2022 at 9:07am

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

Comment by Dr. Krishna Kumari Challa on June 21, 2022 at 8:51am

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

Comment by Dr. Krishna Kumari Challa on June 21, 2022 at 8:42am

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

Comment by Dr. Krishna Kumari Challa on June 21, 2022 at 8:24am

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

Comment by Dr. Krishna Kumari Challa on June 18, 2022 at 10:24am

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-...

Comment by Dr. Krishna Kumari Challa on June 18, 2022 at 9:37am

Bluetooth signals can be used to identify and track smartphones

Comment by Dr. Krishna Kumari Challa on June 18, 2022 at 9:33am

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

Comment by Dr. Krishna Kumari Challa on June 18, 2022 at 9:30am

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

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