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Comment by Dr. Krishna Kumari Challa on November 15, 2022 at 12:01pm

X Chromosome Silenced in Some Cancers in Males

A study finds that XIST, the gene that shuts down one X chromosome in people who have two, is linked to cancer in males. 

Humans only need one active X chromosome, which means that people with two must shut one down to avoid doubling up on its protein products. The gene tasked with inactivating one X, called XIST, codes for a long noncoding RNA that coats and epigenetically silences the extra X chromosome early in the development of people with two X chromosomes. XIST has previously been linked to cancer in females, as well as to testicular cancer. Now, in a study published November 9 in Cell Systems, researchers have found XIST activity in cancers in various somatic tissues of males, too. 

Irregular XIST activity has been linked to testicular cancers, which arise from male germ cells. But in the new study, the researchers found high levels of XIST RNA in male somatic cells sampled from cancerous tissues. While the study doesn’t show a causal link been XIST expression and male cancers, it finds that XIST shuts down X chromosome gene expression in adult male somatic cells, which are thought to need the proteins encoded on the X chromosome. This silencing likely has deleterious effects, the researchers say. 

We’ve known about the testicular cancers having XIST, and we’ve probably suspected that there’s XIST in some other [cancers], but to actually do such a detailed study across all types of cancers and find out the details is really important.

https://www.cell.com/cell-systems/fulltext/S2405-4712(22)00403-3

Comment by Dr. Krishna Kumari Challa on November 15, 2022 at 11:34am

Treated wastewater can be more dependable and less toxic than commo...

Recycled wastewater is not only as safe to drink as conventional potable water, it may even be less toxic than many sources of water we already drink daily, Stanford University engineers have discovered.

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Global carbon emissions at record levels with no signs of shrinking...

Global carbon dioxide emissions from all human activities remain at record highs in 2022, and fossil fuel emissions have risen above pre-pandemic levels, according to a new analysis by an international body of scientists.

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Safety in space: Synthetic hibernation could provide protection fro...

It is still a glimpse into the future: Astronauts could be put into artificial hibernation and in this state be better protected from cosmic radiation. At present, there are already promising approaches to follow up such considerations.

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Climate change creates complications for concrete

Pennsylvania drivers know the effects that weather can have on paved roads—potholes, cracks and other pavement woes are a common occurrence. Climate change is accelerating the process, with devastating consequences for infrastructure.

Comment by Dr. Krishna Kumari Challa on November 15, 2022 at 11:03am

Oldest evidence of the controlled use of fire to cook food

The remains of a huge carp fish (2 meters/6.5 feet long), analyzed by researchers recently mark the earliest signs of cooking by prehistoric human to 780,000 years ago, predating the available data by some 600,000 years.

A close analysis of the remains of a carp-like fish found at the Gesher Benot Ya'aqov (GBY) archaeological site in Israel shows that the fish were cooked roughly 780,000 years ago. Cooking is defined as the ability to process food by controlling the temperature at which it is heated and includes a wide range of methods.

Until now, the earliest evidence of cooking dates to approximately 170,000 years ago. The question of when early man began using fire to cook food has been the subject of much scientific discussion for over a century. These findings shed new light on the matter and was published in Nature Ecology and Evolution.

Irit Zohar, Evidence for the cooking of fish 780,000 years ago at Gesher Benot Ya'aqov, Israel, Nature Ecology & Evolution (2022). DOI: 10.1038/s41559-022-01910-z. www.nature.com/articles/s41559-022-01910-z

Comment by Dr. Krishna Kumari Challa on November 14, 2022 at 10:05am

Making melanoma immortal: Scientists discover key genetic step in cancer's race to live forever

Scientists  have discovered the missing puzzle piece in the mystery of how melanoma tumors control their mortality.

In a paper published in Science last week, they described how they discovered the perfect combination of genetic alterations that tumors use to promote explosive growth and prevent their own demise, a development that could change the way oncologists understand and treat melanoma.

Telomeres, protective caps at the of the end of the chromosome, are required to prevent DNA from degrading. In healthy cells, telomeres become shorter with each cycle of replication until they become so short that the cell can no longer divide. Disruptions in maintenance of the length of the telomeres can lead to severe disease. Short telomere syndromes lead to premature aging and death, but extra-long telomeres are associated with cancer.

For years, scientists have observed strikingly long telomeres in melanoma tumors, especially in comparison with other cancer types.

There's some special link between melanoma and telomere maintenance. For a melanocyte to transform into cancer, one of the biggest hurdles is to immortalize itself. Once it can do that, it's well on its way to cancer.

The telomerase protein is responsible for elongating telomeres, protecting them from damage and preventing cell death. Telomerase is inactive in most cells, but many types of cancers use mutations in the telomerase gene, TERT, that activate this protein and allow cells to continue growing. Melanoma is particularly well-known for doing just this.

About 75% of melanoma tumors contain mutations in the TERT gene that stimulate protein production and increase telomerase activity. Yet, when scientists mutated TERT in melanocytes, they weren't able to produce the same long telomeres seen in their patient's tumors. It turned out that TERT promoter mutations were just half of the story.

 To find the missing link between melanoma, TERT promoter mutations and long telomeres, scientists combed through cancer mutation databases. They had previously discovered a region in a telomere binding protein called TPP1, which was often mutated in melanoma tumors. They now found that the mutations in TPP1 were strikingly similar to those of TERT; they were located in the newly annotated promoter region of TPP1 and stimulated production of the protein. This was exciting to researchers because TPP1 has long been known to stimulate telomerase activity.

So they  added mutated TERT and TPP1 back to cells, the two proteins synergized to create the distinctively long telomeres seen in melanoma tumors. TPP1 was the missing factor scientists had been searching for, and it was hiding in plain sight all along.

This discovery has changed the way scientists understand the onset of melanoma, but it also has the potential to improve treatment. By identifying a telomere maintenance system that is unique to cancer, scientists have a new target for treatments.

Pattra Chun-On et al, TPP1 promoter mutations cooperate with TERT promoter mutations to lengthen telomeres in melanoma, Science (2022). DOI: 10.1126/science.abq0607. www.science.org/doi/10.1126/science.abq0607

Comment by Dr. Krishna Kumari Challa on November 13, 2022 at 11:35am

Protected from a form of cell death, women are more resilient to kidney disease

In the battle of the sexes, women beat men in their ability to recover from kidney injury. Scientists now know why.

Females, it turns out, have an advantage at the molecular level that protects them from a form of cell death that occurs in injured kidneys. This protection could be exploited as a potential therapeutic.

 It is a form of cell death called ferroptosis, which 's only recently discovered. This form of cell death is dependent on iron and oxidative stress. It has been identified as a key player in kidney diseases.

Using genetic and single-cell RNA transcriptomic analysis in mice, the researchers found that being female confers striking protection against ferroptosis through a particular pathway called nuclear factor erythroid 2–related factor 2, or NRF2.

In females, NRF2 is highly active, keeping cell death in check. In males, however, the sex hormone testosterone reduces the activity of NRF2, thus promoting ferroptosis and undermining cell resiliency in kidney injury.

Further experiments showed that chemically activating NRF2 protected male kidney cells from ferroptosis, demonstrating that NRF2 could be a potential therapeutic target to prevent failed renal repair after acute kidney injury.

Tomokazu Souma, Sex differences in resilience to ferroptosis underlie sexual dimorphism in kidney injury and repair, Cell Reports (2022). DOI: 10.1016/j.celrep.2022.111610. www.cell.com/cell-reports/full … 2211-1247(22)01479-6

Comment by Dr. Krishna Kumari Challa on November 13, 2022 at 10:47am

First ever clinical trial of lab-grown red blood cell transfusion

Researchers are taking part in the world’s first clinical trial of red blood cells that have been grown in a laboratory for transfusion into another person.

Comment by Dr. Krishna Kumari Challa on November 12, 2022 at 11:20am

'Threat multiplier': How climate change affects health

Deadlier than COVID, or even rivalling cancer? Researchers have been increasingly attempting to calculate the effect climate change will have on health if the world does not act quickly to reduce carbon emissions.

The World Health Organization, which says climate change is the single biggest health threat facing humanity, has called for the issue to be "front and centre" in negotiations at the COP27 summit being held in Egypt.

But quantifying the overall impact is an extremely complicated task, experts told AFP, because global warming affects health in many different ways, from the immediate dangers of rising heat and extreme weather to longer-term food and water shortages, air pollution and disease.

The WHO estimates that climate change will cause 250,000 extra deaths a year from malnutrition, malaria, diarrhoea and heat stress between 2030 and 2050.That is widely thought to be a "massively conservative estimate" of the true toll, partly because it only comes from four sources. And Climate change is a threat multiplier.

As climate change worsens, we're going to see the biggest threats to human health increase.Nearly 70 percent of all deaths worldwide are from diseases that could be made worse by global warming, according to a report this year from the IPCC, the United Nations' panel of climate experts.

Another major health threat comes from food shortages. Nearly 100 million additional people faced severe food insecurity in 2020 compared to 1981-2010, according to a report last month from The Lancet Countdown, a leading effort to quantify climate change's impact on health.

Extreme drought has increased by nearly a third over the last 50 years, it added, putting hundreds of millions at risk of lacking access to fresh water.

And air pollution contributed to 3.3 million deaths in 2020, 1.2 million of which were directly related to fossil fuel emissions, the report found.

Researchers have also been sounding the alarm that warmer temperatures are pushing virus-carrying animals like mosquitoes into new areas, increasing the spread of existing diseases—and raising the risk of new ones jumping across to humans.

The likelihood of dengue transmission rose by 12 percent over the last 50 years, while warming temperatures extended malaria season in parts of Africa by 14 percent, The Lancet Countdown report said.

Projecting into the future, a new platform launched last week by the United Nations Development Programme and the Climate Impact Lab warned that global warming could become deadlier than cancer in some parts of the world.

Under the modelling research's worst-case scenario in which fossil fuel emissions are not rapidly scaled back, climate change could cause death rates to increase by 53 deaths per 100,000 people worldwide by 2100—around double the current rate for lung cancer.

For the current global population, that would mean 4.2 million additional deaths a year, more than the official toll from COVID-19 in 2021.

Climate change will influence every aspect of public health in the future.

Source:  AFP

https://phys.org/news/2022-11-threat-climate-affects-health.html?ut...

Comment by Dr. Krishna Kumari Challa on November 12, 2022 at 11:09am

Nanocrystals store light energy and drive chemical reactions

Chemistry is increasingly making use of the trick plants can do with photosynthesis: driving chemical reactions that run poorly or do not occur spontaneously at all with light energy. This requires suitable photocatalysts that capture light energy and make it available for the reaction. In the journal Angewandte Chemie, a  research team has now introduced layered core/shell quantum dots that efficiently drive challenging organic transformations. Their low toxicity is a particular advantage.

Quantum dots are finely dispersed nanoscopic crystals of inorganic semiconductors. They absorb strongly in an adjustable range of the spectrum and are easy to recycle. Until now, photocatalytic quantum dots have been based almost exclusively on the highly toxic elements cadmium and lead. This and their limited efficiency have been the main barriers to their broader use.

A research team  has now introduced novel quantum dots with very low toxicity and very high performance. They are activated by commercially available blue LEDs—the UV light that is usually required is not needed. The secret to their success lies in their core/shell structure and the variable coatings that can be used to "store" the light energy.

The quantum dots are only a few nanometers wide. Their core consists of zinc selenide (ZnSe) and is surrounded by a thin shell made of zinc sulfide (ZnS). Blue light raises the zinc selenide to an excited state in which it can easily give up electrons. The shell prevents the electrons from immediately being captured by so-called defects. The team equipped the surface of the shell with special benzophenone ligands that "suck up" the electrons from the quantum dots, store them, and make them available for organic reactions. For example, the team was able to carry out reductive dehalogenations of aryl chlorides and additive-free polymerizations of acrylates—important reactions that run poorly or not at all by conventional photocatalysts. A second version was made by coating the surface with biphenyl ligands that can directly absorb energy from excited quantum dots. This brings them into a long-lived, highly energetic triplet state. The triplet energy "stored" in this way can be transferred to specific organic molecules, which then also enter a triplet state. In this state, they can undergo chemical reactions that are not possible in their ground state. As a demonstration, the team carried out [2+2] homo-cycloadditions of styrene and cycloadditions of carbonyls with alkenes. These produce four-membered rings (cyclobutanes or oxetanes, respectively), which are substances that are important starting materials in areas such as pharmaceutical development.

 Chengming Nie et al, Low‐Toxicity ZnSe/ZnS Quantum Dots as Potent Photoreductants and Triplet Sensitizers for Organic Transformations, Angewandte Chemie International Edition (2022). DOI: 10.1002/anie.202213065

Comment by Dr. Krishna Kumari Challa on November 12, 2022 at 11:06am

Nanocrystals store light energy and drive chemical reactions

Chemistry is increasingly making use of the trick plants can do with photosynthesis: driving chemical reactions that run poorly or do not occur spontaneously at all with light energy. This requires suitable photocatalysts that capture light energy and make it available for the reaction. In the journal Angewandte Chemie, a Chinese research team has now introduced layered core/shell quantum dots that efficiently drive challenging organic transformations. Their low toxicity is a particular advantage.

Comment by Dr. Krishna Kumari Challa on November 12, 2022 at 10:30am

A microscopic video shows a virus (purple track) as it finds its way to the surface of human intestinal cells (green).

Researchers have captured the first real-time footage of viruses on the move, right before they hijack a cell.

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