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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

Comment by Dr. Krishna Kumari Challa on June 18, 2022 at 9:12am

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

Comment by Dr. Krishna Kumari Challa on June 18, 2022 at 8:40am

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

Comment by Dr. Krishna Kumari Challa on June 17, 2022 at 12:21pm

Climate change catastrophe: Phytoplankton Productivity Down 65%

Comment by Dr. Krishna Kumari Challa on June 16, 2022 at 11:10am

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...

Comment by Dr. Krishna Kumari Challa on June 16, 2022 at 9:27am

Gender Inclusive Science Communication-Opportunities & Challenges

Comment by Dr. Krishna Kumari Challa on June 16, 2022 at 8:56am

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

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