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Comment by Dr. Krishna Kumari Challa on September 14, 2022 at 12:00pm

The blood stem cell research that could change medicine of the future

Biomedical engineers and medical researchers have independently made discoveries about embryonic blood stem cell creation that could one day eliminate the need for blood stem cell donors.

The achievements are part of a move in regenerative medicine towards the use of "induced pluripotent stem cells" to treat disease, where stem cells are reverse engineered from adult tissue cells rather than using live human or animal embryos.

But while we have known about induced pluripotent stem cells since 2006, scientists still have plenty to learn about how cell differentiation in the human body can be mimicked artificially and safely in the lab for the purposes of delivering targeted medical treatment.

Two studies have emerged  in this area that shine new light on not only how the precursors to blood stem cells occur in animals and humans, but how they may be induced artificially.

In a study published today in Cell Reports, researchers demonstrated how a simulation of an embryo's beating heart using a microfluidic device in the lab led to the development of human blood stem cell "precursors," which are stem cells on the verge of becoming blood stem cells.

 They made a device mimicking the heart beating and the blood circulation and an orbital shaking system which causes shear stress—or friction—of the blood cells as they move through the device or around in a dish."

These systems promoted the development of precursor blood stem cells which can differentiate into various blood components—white blood cells, red blood cells, platelets and others. They were excited to see this same process—known as hematopoiesis—replicated in the device.

And in an article published in Nature Cell Biology in July, another group of researchers revealed the identity of cells in mice embryos responsible for blood stem cell creation. They researchers looked for the mechanism that is used naturally in mammals to make blood stem cells from the cells that line blood vessels, known as endothelial cells. They  identified the cells in the embryo that can convert both embryonic and adult endothelial cells into blood cells in the process.

Both studies are significant steps towards an understanding of how, when, where and which cells are involved in the creation of blood stem cells. In the future, this knowledge could be used to help cancer patients, among others, who have undergone high doses of radio- and chemotherapy, to replenish their depleted blood stem cells.

 Robert E. Nordon, Mimicry of embryonic circulation enhances the hoxa hemogenic niche and human blood development, Cell Reports (2022). DOI: 10.1016/j.celrep.2022.111339. www.cell.com/cell-reports/full … 2211-1247(22)01167-6

Vashe Chandrakanthan et al, Mesoderm-derived PDGFRA+ cells regulate the emergence of hematopoietic stem cells in the dorsal aorta, Nature Cell Biology (2022). DOI: 10.1038/s41556-022-00955-3

Comment by Dr. Krishna Kumari Challa on September 14, 2022 at 9:50am

Research says  the best way to soothe a crying infant is by carrying them on a 5-minute walk

Most parents have experienced frustration when their infants cry excessively and refuse to sleep. Scientists have found that the best strategy to calm them down is by holding and walking with them for five minutes. This evidence-based soothing strategy is presented in a paper published September 13 in the journal Current Biology.

Many parents suffer from babies' nighttime crying. That's such a big issue, especially for inexperienced parents, that can lead to parental stress and even to infant maltreatment in a small number of cases.

researchers compared 21 infants' responses while under four conditions: being held by their walking mothers, held by their sitting mothers, lying in a still crib, or lying in a rocking cot. The team found that when the mother walked while carrying the baby, the crying infants calmed down and their heart rates slowed within 30 seconds. A similar calming effect occurred when the infants were placed in a rocking cot, but not when the mother held the baby while sitting or placed the baby in a still crib.

This suggests that holding a baby alone might be insufficient in soothing crying infants, contradicting the traditional assumption that maternal holding reduces infant distress. At the same time, movement has calming effects, likely activating a baby's transport response. The effect was more evident when the holding and walking motions continued for five minutes. All crying babies in the study stopped crying, and nearly half of them fell asleep.

But when the mothers tried to put their sleepy babies to bed, more than one-third of the participants became alert again within 20 seconds. The team found that all babies produced physiological responses, including changes in heart rate, that can wake them up the second their bodies detach from their mothers. However, if the infants were asleep for a longer period before being laid down, they were less likely to awaken during the process, the researchers found.

They recommend that parents hold crying infants and walk with them for five minutes, followed by sitting and holding infants for another five to eight minutes before putting them to bed. The protocol, unlike other popular sleep training approaches such as letting infants cry until they fall asleep themselves, aims to provide an immediate solution for infant crying. 

You might ask, don't we already know this? 

But we need science to understand a baby's behaviours, because they're much more complex and diverse than we thought. What you think you know is different from what a scientific study reveals.

Kumi O. Kuroda, A method to soothe and promote sleep in crying infants utilizing the Transport Response, Current Biology (2022). DOI: 10.1016/j.cub.2022.08.041. www.cell.com/current-biology/f … 0960-9822(22)01363-X

Comment by Dr. Krishna Kumari Challa on September 13, 2022 at 10:29am

Study finds antibiotics may make melanoma worse, by depleting the gut microbiome

The use of broad-spectrum antibiotics in mice with malignant melanoma, an aggressive form of skin cancer, accelerated their metastatic bone growth, likely because the drugs depleted the mice's intestinal flora and weakened their immune response, according to a new study by researchers.

The findings underscore the importance of the gut microbiome in overall health and suggest that doctors should carefully weigh the gastrointestinal effects when they use antibiotic therapies while treating cancer or other diseases.

Any disease or therapy that harms the gut microbiome could have a negative impact on our health.

This new study  found that the gut microbiome restrains the progression of melanoma bone lesions in mice by promoting the expansion of intestinal natural-killer (NK) cells and T helper (Th1) cells and enhancing their migration to the tumour site. Using oral antibiotics depleted the gut microbiome and reduced the population of intestinal NK cells and Th1 cells. This made the mice more vulnerable for tumour growth. They had a higher melanoma tumor burden than control mice whose gut microbiomes were intact.

https://www.jci.org/articles/view/157340

Comment by Dr. Krishna Kumari Challa on September 13, 2022 at 10:16am

Scientists discover how air pollution triggers lung cancer

Scientists  have identified the mechanism through which air pollution triggers lung cancer in non-smokers, a discovery one expert hailed as "an important step for science—and for society".

The research illustrated the health risk posed by the tiny particles produced by burning fossil fuels, sparking fresh calls for more urgent action to combat climate change. It could also pave the way for a new field of cancer prevention.

Scientists presented the research, which has not yet been published in a peer-reviewed journal, at the European Society for Medical Oncology's annual conference in Paris.

Air pollution has long been thought to be linked to a higher risk of lung cancer in people who have never smoked.

Researchers found that exposure to tiny PM2.5 pollution particles—which are less than 2.5 microns across—led to an increased risk of mutations in the EGFR gene. In laboratory studies on mice, they  showed that the particles caused changes in the EGFR gene as well as in the KRAS gene, both of which have been linked to lung cancer.

Finally, they analyzed nearly 250 samples of human lung tissue never exposed to carcinogens from smoking or heavy pollution.

Even though the lungs were healthy, they found DNA mutations in 18 percent of EGFR genes and 33 percent of KRAS genes.

They're just sitting there and the mutations seem to increase with age. On their own, they probably are insufficient to drive cancer.

But when a cell is exposed to pollution it can trigger a "wound-healing response" that causes inflammation. And if that cell harbours a mutation, it will then form a cancer.

In another experiment on mice, the researchers showed that an antibody could block the mediator—called interleukin 1 beta—which sparks the inflammation, stopping cancer from getting started in the first place.

LBA1 'Mechanism of action and an actionable inflammatory axis for air pollution induced non-small cell lung cancer in never smokers' will be presented by Charles Swanton during Presidential Symposium 1 on Saturday, 10 September, 16:30 to 18:00 CEST in Paris Auditorium. Annals of Oncology, Volume 33 Supplement 7, September 2022. www.esmo.org/meetings/esmo-congress-2022

Comment by Dr. Krishna Kumari Challa on September 10, 2022 at 8:52am

A plastic film that can kill viruses using room lights

Researchers  have developed a plastic film that can kill viruses that land on its surface with room light. The self-sterilizing film is the first of its kind—it is low cost to produce, can be readily scaled and could be used for disposable aprons, tablecloths, and curtains in hospitals. It is coated with a thin layer of particles that absorb UV light and produce reactive oxygen species—ROS. These kill viruses, including SARS-CoV-2.

The technology used to create the film also ensures it is degradable—unlike the current disposable plastic films it would replace, which is much more environmentally friendly. The breakthrough could lead to a significant reduction in the transmission of viruses in healthcare environments but also in other settings that uses plastic films—for example, food production factories.

Researchers tested the film for anti-viral activity using four different viruses—two strains of influenza A virus, a highly-stable picornavirus called EMCV and SARS-CoV-2—exposing it to either UVA radiation or with light from a cool white light fluorescent lamp.

They found that the film is effective at killing all of the viruses—even in a room lit with just white fluorescent tubes.

Ri Han et al, Flexible, disposable photocatalytic plastic films for the destruction of viruses, Journal of Photochemistry and Photobiology B: Biology (2022). DOI: 10.1016/j.jphotobiol.2022.112551

Comment by Dr. Krishna Kumari Challa on September 10, 2022 at 8:49am

Gut microbes may lead to therapies for mental illness, study reports

The role of the microbiome in intestinal and systemic health has garnered close attention among researchers for many years. Now evidence is mounting that this collection of microorganisms in the human gut can also impact a person's neurological and emotional health, according to a recent perspective article in Science by a UT Southwestern researcher.

Scientists are unraveling the relationship of the microbiome to the brain, including connections to diseases such as depression and amyotrophic lateral sclerosis (ALS). 

Jane A. Foster, Modulating brain function with microbiota, Science (2022). DOI: 10.1126/science.abo4220

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Comment by Dr. Krishna Kumari Challa on September 10, 2022 at 8:46am

Antibiotics given in infancy may have adverse impact on adult gut health

Preterm and low birth-weight babies are routinely given antibiotics to prevent⁠—not just treat⁠—infections, which they have a high risk of developing. A new study published in The Journal of Physiology has found that early life exposure to antibiotics in neonatal mice has long-lasting effects on their microbiota, enteric nervous system, and gut function. This could mean that babies given antibiotics may grow up to experience gastrointestinal issues.

This discovery by a research team  is the first to show that antibiotics given to neonatal mice yields these long-lasting effects that result in disturbed gastrointestinal function, including the speed of motility through the gut and diarrhea-like symptoms in adulthood.

The research team gave mice an oral dose of vancomycin every day for the first ten days of their lives. They were then reared normally until they were young adults, and their gut tissue was looked at to measure its structure, function, microbiota, and nervous system. The investigators found that changes were also dependent on the sex of the mice. The females had long whole gut transit and the males had lower fecal weight than the control group. Both males and females had greater fecal water content, which is a diarrhea-like symptom.

Neonatal antibiotics have long-term sex-dependent effects on the enteric nervous system, The Journal of Physiology (2022). DOI: 10.1113/JP282939

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Comment by Dr. Krishna Kumari Challa on September 9, 2022 at 10:20am

The first known surgical amputation

Prehistoric child’s amputation is oldest surgery of its kind

Skeleton missing lower left leg and dated to 31,000 years ago provides the earliest known evidence for surgical limb removal.

The skeleton of a person who lived 31,000 years ago bears hallmarks of the deliberate removal of their lower left leg — the earliest known surgery of its kind. Discovered in a limestone cave in Borneo, the remains pre-date the previous oldest known case of limb amputation by more than 20,000 years. The person appears to have survived for at least six to nine years after the surgery.

Comment by Dr. Krishna Kumari Challa on September 9, 2022 at 9:45am

Two new trials find no link between vitamin D supplements and reduced risk of COVID-19

Two large clinical trials published by The BMJ today show that boosting vitamin D levels in adults during the SARS-CoV-2 pandemic was not associated with protection against respiratory tract infections or COVID-19.

Vitamin D metabolites have long been recognized to support innate immune responses to respiratory viruses and bacteria, and some studies have shown that vitamin D may protect against respiratory tract infections, particularly among those who are vitamin D-deficient.

Vitamin D has therefore received much attention for its potential role in preventing and treating COVID-19, but most studies published so far are observational and have shown mixed results.

The first trial was carried out in the UK between December 2020 and June 2021 and involved 6,200 adults (16 years and over) not using vitamin D supplements at enrollment.

Half (3,100 participants) were offered a vitamin D blood test and those found to have low vitamin D levels (2,674; 86%) received either 3200 IU/day or 800 IU/day of vitamin D supplements for six months, while the other half (controls) received no test or supplements.

Neither of the vitamin D doses showed any effect on diagnosed acute respiratory tract infections or lateral flow test or RT-PCR-confirmed COVID-19 cases over a six-month follow-up period. The number of adverse events was similar between groups, and no serious adverse event was attributed to study supplements.

The second trial was conducted in Norway between November 2020 and June 2021 using cod liver oil, which contains low doses of vitamin D and vitamin A as well as omega-3 fatty acids.

A total of 34,741 adults (18-75 years) who were not using vitamin D supplements received either 5 mL cod liver oil or 5 mL placebo (corn oil) daily for six months. The majority of participants (86%) who were tested had adequate vitamin D levels at the start of the study.

Again, the researchers found no effect of cod liver oil on acute respiratory infections or PCR-confirmed COVID-19, compared with placebo. The cod liver oil group had no more side effects than the placebo group and only low-grade side effects were reported.

Effect of a test-and-treat approach to vitamin D supplementation on risk of all cause acute respiratory tract infection and covid-19: phase 3 randomised controlled trial (CORONAVIT), The BMJ (2022). DOI: 10.1136/bmj-2022-071230

Comment by Dr. Krishna Kumari Challa on September 9, 2022 at 9:42am

Intelligent microscopes for detecting rare biological events

Now researchers need not wait for hours together to image bacterial cells division

Biophysicists have now found a way to automate microscope control for imaging biological events in detail while limiting stress on the sample, all with the help of artificial neural networks. Their technique works for bacterial cell division, and for mitochondrial division. The details of their intelligent microscope are described in Nature Methods.

Suliana Manley, Event-driven acquisition for content-enriched microscopy, Nature Methods (2022). DOI: 10.1038/s41592-022-01589-x. www.nature.com/articles/s41592-022-01589-x

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