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Comment by Dr. Krishna Kumari Challa on May 18, 2024 at 8:31am

New technique to freeze brain tissue without harm

A team of medical researchers has developed a technique to freeze and thaw brain tissue without causing damage.
In their study, published in the journal Cell Reports Methods, the group tested bathing brain organoid tissue in candidate chemicals before freezing them using liquid nitrogen.

Prior research has shown that no matter how quickly brain matter is frozen, the freezing and thawing process always causes tissue damage. This has made it more difficult for researchers to study brain matter because research must be conducted immediately after obtaining a tissue sample. In this new effort, the team  found a way around this problem by soaking the tissue in a special solution before freezing.

The work involved dipping or soaking brain organoids (brain tissue grown from stem cells) in candidate compounds and then freezing and thawing them to see how they fared. After many attempts, they found one combination of solutions that worked best—a mix of ethylene glycol, methylcellulose DMSO and Y27632. They named the solution mix MEDY.

The research team then tested MEDY under a variety of conditions to see how well it prevented damage from freezing. The conditions involved changing variables, such as the age of the organoids prior to freezing and how long they were soaked in a MEDY solution. They then allowed the organoids to resume growing after they were thawed for up to 150 days.

The researchers found little difference between organoids that had been frozen and those that had not—even those that had been frozen for as long as 18 months.

As a final test, the research team used their technique on a sample of brain tissue obtained from a live human patient and found that it worked just as well.

The research team suggests that their technique should allow researchers to store brain tissue samples on a scale large enough to allow for new types of brain and nervous system research.

Weiwei Xue et al, Effective cryopreservation of human brain tissue and neural organoids, Cell Reports Methods (2024). DOI: 10.1016/j.crmeth.2024.100777

Comment by Dr. Krishna Kumari Challa on May 18, 2024 at 8:28am

Gut bacteria enhance cancer immunotherapy in mouse study

Roughly one in five cancer patients benefit from immunotherapy—a treatment that harnesses the immune system to fight cancer. Such an approach to beating cancer has seen significant success in lung cancer and melanoma, among others. Optimistic about its potential, researchers are exploring strategies to improve immunotherapy for cancers that don't respond well to the treatment, with the hope of benefiting more patients.

Cancer immunotherapy employs the body's immune cells to target and destroy tumors. One such treatment uses immune checkpoint inhibitor drugs to unleash the immune system by releasing the natural brakes that keep immune T cells quiet, a feature that prevents the body from harming itself. But some tumors fight back to suppress the attacking immune cells, damping the effectiveness of such inhibitors.

Now, researchers have found, in mice, that a strain of gut bacteria—Ruminococcus gnavus—can enhance the effects of cancer immunotherapy. The study, which appears May 17 in Science Immunology, suggests a new strategy of using gut microbes to help unlock immunotherapy's untapped cancer-fighting potential.

R. gnavus has been found in gut microbiota of cancer patients who respond well to immunotherapy. In clinical trials, fecal transplants from such individuals have helped some unresponsive patients reap immunotherapy's benefits.

Blanda Di Luccia et al, TREM2 deficiency reprograms intestinal macrophages and microbiota to enhance anti-PD-1 tumor immunotherapy, Science Immunology (2024). DOI: 10.1126/sciimmunol.adi5374. www.science.org/doi/10.1126/sciimmunol.adi5374

Comment by Dr. Krishna Kumari Challa on May 16, 2024 at 11:08am

Scientists generate heat over 1,000°C with solar power instead of fossil fuel

Instead of burning fossil fuels to smelt steel and cook cement, researchers in Switzerland want to use heat from the sun. The proof-of-concept study, published May 15 in the journal Device, uses synthetic quartz to trap solar energy at temperatures over 1,000°C (1,832°F), demonstrating the method's potential role in providing clean energy for carbon-intensive industries.

Glass, steel, cement, and ceramics are at the very heart of modern civilization, essential for building everything from car engines to skyscrapers. However, manufacturing these materials demands temperatures over 1,000°C and relies heavily on burning fossil fuels for heat. These industries account for about 25% of global energy consumption.

Researchers have explored a clean-energy alternative using solar receivers, which concentrate and build heat with thousands of sun-tracking mirrors. However, this technology has difficulties transferring solar energy efficiently above 1,000°C.

To boost the efficiency of solar receivers, the researchers  turned to semitransparent materials such as quartz, which can trap sunlight—a phenomenon called the thermal-trap effect. The team crafted a thermal-trapping device by attaching a synthetic quartz rod to an opaque silicon disk as an energy absorber.

When they exposed the device to an energy flux equivalent to the light coming from 136 suns, the absorber plate reached 1,050°C (1,922°F), whereas the other end of the quartz rod remained at 600°C (1,112°F).

Using a heat transfer model, the team also simulated the quartz's thermal-trapping efficiency under different conditions. The model showed that thermal trapping achieves the target temperature at lower concentrations with the same performance, or at higher thermal efficiency for equal concentration. 

Solar thermal trapping at 1000 ºC and above, Device (2024). DOI: 10.1016/j.device.2024.100399. www.cell.com/device/fulltext/S2666-9986(24)00235-7

Comment by Dr. Krishna Kumari Challa on May 16, 2024 at 11:00am

Identifying proteomic risk factors for cancer using prospective and exome analyses of 1,463 circulating proteins and risk of 19 cancers in the UK Biobank, Nature Communications (2024). www.nature.com/articles/s41467-024-48017-6

Karl Smith-Byrne et al, Identifying therapeutic targets for cancer among 2074 circulating proteins and risk of nine cancers, Nature Communications (2024). DOI: 10.1038/s41467-024-46834-3

Part 2

Comment by Dr. Krishna Kumari Challa on May 16, 2024 at 10:59am

Scientists discover blood proteins that may give cancer warning seven years before diagnosis

Two studies  have discovered proteins in the blood that could warn people of cancer more than seven years before it is diagnosed.

Scientists identified 618 proteins linked to 19 different types of cancer, including 107 proteins in a group of people who blood was collected at least seven years before diagnosis. The team has discovered that these proteins could be involved at the very earliest stages of cancer, where it could be prevented.

They think that some of these proteins could be used to detect cancer much earlier than is currently possible. In the future, this could help treat the disease at a much earlier stage or prevent it altogether.

The papers, titled "Identifying proteomic risk factors for cancer using prospective and exome analyses of 1,463 circulating proteins and risk of 19 cancers in the UK Biobank" and "Identifying therapeutic targets for cancer among 2,074 circulating proteins and risk of nine cancers," are published in Nature Communications.

In these studies, the team used a powerful technique called proteomics. Proteomics allows scientists to analyze a large set of proteins in tissue samples at a single point in time, to see how they interact with each other and find any important differences in proteins between different tissue samples.

In the first study, scientists analyzed blood samples from UK Biobank that had been taken from more than 44,000 people, including over 4,900 people who subsequently had a cancer diagnosis.

Using proteomics, the team analyzed a set of 1,463 proteins from a single sample of blood from each person. They compared the proteins of people who did and did not go on to be diagnosed with cancer to look for important differences between them and find out which ones were linked to cancer risk. The scientists also identified 182 proteins that differed in the blood three years before a cancer diagnosis took place.

In the second study, the scientists looked at genetic data from over 300,000 cancer cases to do a deep dive into which blood proteins were involved in cancer development and could be targeted by new treatments.

The scientists found 40 proteins in the blood that influenced someone's risk of getting 9 different types of cancer. While altering these proteins may increase or decrease the chances of someone developing cancer, the scientists also found that in some cases this may lead to unintended side effects.

However, the team stressed that they will need to do further research to find out the exact role these proteins play in cancer development, which of the proteins are the most reliable ones to test for, which tests could be developed to detect the proteins in the clinic, and which drugs could target these proteins.

Part 1

Comment by Dr. Krishna Kumari Challa on May 15, 2024 at 9:12am

Scientists develop sticky pesticide to combat pest insects

Researchers  have engineered a biological barrier that protects plants from diseases and pests. It concerns a sticky substance that is sprayed on leaves, to which pests stick.

The researchers hope that this insect glue will help to reduce the use of toxic chemical pesticides. They published their findings in the Proceedings of the National Academy of Sciences.

In the search for alternatives, scientists  turned to nature for inspiration. The carnivorous sundew plant has so-called glandular hairs that secrete a sticky substance to catch insects. The researchers wanted to mimic this to protect the plants and crops in a natural way.

The researchers succeeded in their endeavor.

They transformed vegetable rice oil into a yellow, sticky substance by blowing air over it and grinding it into small particles using a laboratory blender. This results in beads of about one millimeter in diameter that are as sticky as duct tape. The size matches one of the common pest insect: thrips. By catching these insects, plants stay healthier and are less likely to become infected with fungi that the thrips carry with them.

So far, the researchers mainly focused on this type of pest, but the insect glue may also work against other pests, such as the Suzuki fruit fly that currently threatens cherry cultivation. At the same time, the drops are small enough that beneficial insects, such as pollinators, do not get stuck.

Unlike chemical pesticides, insects are unlikely to develop resistance against this adhesive, the researchers think. 

Insects have already evolved so that they avoid adhesion, for example through hairs on their body and a bumpy surface. Increasing their body size remains one of the few escape methods from this sticky trap. That is not nearly as easy as developing tolerance to a chemical substance. If it happens at all, it takes many generations and only happens if the insect glue is used on a large scale.

After application, the sticky substance remains on the leaves for three months and cannot be washed off by rain. That is long enough to control pests until harvest. By spraying the insect glue on crops before the fruits develop, farmers minimize the chance of the pesticide getting onto the food. However, contact with food cannot be ruled out.

The advantage of this pesticide over chemical pesticides is that you can see the small, yellow drops. You can wash it off with water and dish soap. If you do ingest some of it, it is probably not harmful. As it is derived from vegetable oil.

 But scientists still need to investigate how (un)healthy it is exactly.

Ralph van Zwieten et al, Mimicking natural deterrent strategies in plants using adhesive spheres, Proceedings of the National Academy of Sciences (2024). DOI: 10.1073/pnas.2321565121

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Comment by Dr. Krishna Kumari Challa on May 15, 2024 at 8:56am

rDNA copy number was also linked with an individual's kidney function within the sample of individuals of European ancestry. A similar effect was seen in samples from other ancestries, but further research using larger sample sizes will be needed to confirm this connection.

 This research highlights the importance of analyzing the whole genome to better understand the factors impacting on our health. This study is also an example of how having access to large biobanks allows us to make unexpected discoveries, and provides new avenues for harnessing the power of genetics to understand human diseases.

Geneticists have long struggled to fully explain the genetic basis of many common complex traits and diseases. This  work suggests that at least part of this missing heritability resides in difficult to sequence regions of the genome such as those encoding ribosomal copy number variation.

Ribosomal DNA Copy Number Variation Associates with Hematological Profiles and Renal Function in the UK Biobank, Cell Genomics (2024). DOI: 10.1016/j.xgen.2024.100562. www.cell.com/cell-genomics/ful … 2666-979X(24)00128-9

Part 2

Comment by Dr. Krishna Kumari Challa on May 15, 2024 at 8:54am

Analysis suggests people with more copies of ribosomal DNA have higher risks of developing disease

Ribosomal DNA (rDNA) is present in hundreds of copies in the genome, but has not previously been part of genetic analyses. A new study of 500,000 individuals indicates that people who have more copies of rDNA are more likely to develop inflammation and diseases during their lifetimes.

Standard genetic analysis techniques have not studied areas of the human genome that are repetitive, such as ribosomal DNA (rDNA), a fundamental part of the molecular mechanism which makes proteins in cells.

A new study has discovered that genetic disposition to disease can be found in these previously understudied areas of the genome.

The results, published in Cell Genomics, suggest that wider genome analysis could bring opportunities for preventative diagnostics, novel therapeutics, and greater insight into the mechanism of different human diseases.

In this study, samples from 500,000 individuals in the UK Biobank project were analyzed. Researchers used new whole genome sequencing (WGS) techniques to identify differences in numbers of copies of rDNA in each sample, and compared them with other health metrics and medical records.
The researchers found that the number of copies of rDNA in an individual showed strong statistical association with well-established markers of systemic inflammation—such as neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), and systemic immune-inflammation index (SII). These statistically significant associations were seen in the genomes of individuals of different ethnicities, suggesting a common indicator for risks of future disease.

Part 1

Comment by Dr. Krishna Kumari Challa on May 15, 2024 at 8:51am

If, as has been historically the case, men are used as a standard model for various disorders, researchers may miss out on critical insight.

While the AI tools could report differences in brain-cell organization, they could not reveal which sex was more likely to have which features.

According to the researchers, the team next plans to explore the development of sex-related brain structure differences over time to better understand environmental, hormonal, and social factors that could play a role in these  changes.

Deep Learning with Diffusion MRI as in vivo Microscope Reveals Sex-related Differences in Human White Matter Microstructure, Scientific Reports (2024).

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Part 2

Comment by Dr. Krishna Kumari Challa on May 15, 2024 at 8:49am

Artificial intelligence tool detects sex-related differences in brain structure

Artificial intelligence (AI) computer programs that process MRI results show differences in how the brains of men and women are organized at a cellular level, a new study shows. These variations were spotted in white matter, tissue primarily located in the human brain's innermost layer, which fosters communication between regions.

The work appears in Scientific Reports.

Men and women are known to experience multiple sclerosis, autism spectrum disorder, migraines, and other brain issues at different rates and with varying symptoms. A detailed understanding of how biological sex impacts the brain is therefore viewed as a way to improve diagnostic tools and treatments. However, while brain size, shape, and weight have been explored, researchers have only a partial picture of the brain's layout at the cellular level.

The new study used an AI technique called machine learning to analyze thousands of MRI brain scans from 471 men and 560 women. Results revealed that the computer programs could accurately distinguish between biological male and female brains by spotting patterns in structure and complexity that were invisible to the human eye.

The findings were validated by three different AI models designed to identify biological sex using their relative strengths in either zeroing in on small portions of white matter or analyzing relationships across larger regions of the brain.

These findings provide a clearer picture of how a living, human brain is structured, which may in turn offer new insight into how many psychiatric and neurological disorders develop and why they can present differently in men and women.

For the research,  researchers started by feeding AI programs existing data examples of brain scans from healthy men and women and also telling the machine programs the biological sex of each brain scan. Since these models were designed to use complex statistical and mathematical methods to get "smarter" over time as they accumulated more data, they eventually "learned" to distinguish biological sex on their own. Importantly, the programs were restricted from using overall brain size and shape to make their determinations.

According to the results, all of the models correctly identified the sex of subject scans between 92% and 98% of the time. Several features in particular helped the machines make their determinations, including how easily and in what direction water could move through brain tissue.

These results highlight the importance of diversity when studying diseases that arise in the human brain.

Part 1

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