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Comment by Dr. Krishna Kumari Challa on September 13, 2023 at 8:50am

Breast cancer recurrence may be triggered by chemotherapy injury to non-cancer cells

A standard chemotherapy drug injures surrounding non-cancer cells, which can then awaken dormant cancer cells and promotes cancer growth, according to a new study published September 12 in the open access journal PLoS Biology. The finding is important for understanding cancer recurrence and may point to important new targets to prevent it.

Advances in cancer treatment, including chemotherapy, have dramatically reduced mortality for many types of cancer, including breast cancer. Nonetheless, up to 23% of breast cancer patients experience recurrence within the first five years. Treatment is meant to kill all cancer cells, but often, some cells enter a state of dormancy, in which they stop dividing and become unresponsive to chemotherapeutic agents. Recurrence occurs when dormant cells re-awaken and start dividing again.

Some studies have indicated that chemotherapy itself may promote escape from dormancy, but the mechanism of this effect has not been clear.

To explore that question, the authors worked with both a cell model and a mouse model of breast cancer. Importantly, the cell model contained both cancer cells and non-cancer stromal cells, connective tissue cells that are found in breast and other tissue. They administered the chemotherapy drug docetaxel at physiologically relevant concentrations, and found that even at very low doses, stromal cells were injured, while cancer cells were not, and that treatment induced cell-cycle reentry in cancer cells.

The driver of this reawakening of dormant cells, the authors showed, was release of two key cell signaling molecules, granulocyte colony stimulating factor (G-CSF) and interleukin-6 (IL-6) by the injured stromal cells, which acted on the dormant cells to promote their growth, both in vitro and in vivo.

That provided the team with potential anti-cancer targets, and they showed that antibodies that neutralized either G-CSF or IL-6, or a drug that blocked the mediator of those signals within cancer cells, inhibited awakening from dormancy due to docetaxel treatment.

These findings have several important implications. First, they highlight the importance of surrounding cells, not just the cancer cells themselves, in determining the response to chemotherapy. Second, they provide a possible mechanistic foundation for the observation that high serum levels of IL-6 are associated with early recurrence in breast cancer patients receiving chemotherapy, potentially strengthening the utility of that biomarker in planning treatment. Third, they provide new targets for preventing recurrence.

Ganesan R, Bhasin SS, Bakhtiary M, Krishnan U, Cheemarla NR, Thomas BE, et al. (2023) Taxane chemotherapy induces stromal injury that leads to breast cancer dormancy escape. PLoS Biology (2023). DOI: 10.1371/journal.pbio.3002275

Comment by Dr. Krishna Kumari Challa on September 12, 2023 at 12:12pm

Bioengineered E. coli generates electricity from wastewater

In a breakthrough for the field of bioelectronics, researchers  have enhanced the ability of E. coli bacteria to generate electricity. The innovative approach offers a sustainable solution for organic waste processing while outperforming previous state-of-the-art technologies, opening new horizons for versatile microbial electricity production.

E. coli bacteria, a staple of biological research, have been harnessed to create electricity through a process known as extracellular electron transfer (EET). The  researchers engineered E. coli bacteria to exhibit enhanced EET, making them highly efficient "electric microbes." Unlike previous methods that required specific chemicals for electricity generation, the bioengineered E. coli can produce electricity while metabolizing a variety of organic substrates.

. By integrating components from Shewanella oneidensis MR-1, a bacterium famous for generating electricity, the researchers successfully constructed an optimized pathway that spans the inner and outer membranes of the cell. This novel pathway surpassed previous partial approaches, and led to a three-fold increase in electrical current generation compared to conventional strategies.

Importantly, the engineered E. coli exhibited remarkable performance in various environments, including wastewater collected from a brewery. While exotic electric microbes faltered, the modified E. coli thrived, showcasing its potential for large-scale waste treatment and energy production.

The implications of the study extend beyond waste treatment. Being able to generate electricity from a wide range of sources, the engineered E. coli can be utilized in microbial fuel cells, electrosynthesis, and biosensing—to name a few applications. In addition, the bacterium's genetic flexibility means that it can be tailored to adapt to specific environments and feedstocks, making it a versatile tool for sustainable technology development.

Mohammed Mouhib, Melania Reggente, Lin Li, Nils Schuergers, Ardemis A. Boghossian. Extracellular electron transfer pathways to enhance the electroactivity of modified Escherichia coli. Joule, 2023; DOI: 10.1016/j.joule.2023.08.006

Comment by Dr. Krishna Kumari Challa on September 12, 2023 at 10:01am

Researchers create optical device that can kill pathogens on surfaces while remaining safe for humans

While it has long been known that ultraviolet (UV) light can help kill disease-causing pathogens, the COVID-19 pandemic has put a spotlight on how these technologies can rid environments of germs. However, the excimer lamps and LEDs that can directly emit light in the required deep-UV wavelengths generally have low efficiency or suffer from short lifetimes. Moreover, UV light of the wrong wavelength can actually be harmful to human cells.

Now, researchers  have shown how an optical device made of aluminum nitride can be used to generate deep-UV light in a method wholly different from previous approaches. The team made use of a process called "second harmonic generation," which relies on the fact that the frequency of a photon, or particle of light, is proportional to its energy. The study is published in the journal Applied Physics Express.

Most transparent materials are considered "linear" with respect to their response to light, i.e., photons cannot interact with each other. However, inside certain "nonlinear" materials, two photons can be combined into a single photon with twice the energy, and thus, twice the frequency. In this case, two visible photons can be merged into a single deep-UV photon inside an aluminum nitride waveguide less than one micron wide. A waveguide is a channel of transparent material with physical dimensions chosen so that light of desired frequencies can travel easily. The waveguide helps take advantage of the nonlinear optical properties of the material, so that second harmonic generation can occur with the highest efficiency.

The wavelength of UV light created by the prototype device is within a very narrow range that has enough energy to kill germs but remains mostly harmless to humans.

 Hiroto Honda et al, 229 nm far-ultraviolet second harmonic generation in a vertical polarity inverted AlN bilayer channel waveguide, Applied Physics Express (2023). DOI: 10.35848/1882-0786/acda79

Comment by Dr. Krishna Kumari Challa on September 12, 2023 at 9:05am

Increasing severe maternal morbidity linked to heat exposure

Research provides strong evidence linking maternal heat exposure during pregnancy to an increased risk of severe maternal morbidity, with potential implications for public health strategies and interventions.

In a paper, "Analysis of Heat Exposure During Pregnancy and Severe Maternal Morbidity," published in JAMA Network Open, researchers explored the potential association between maternal environmental heat exposure and severe maternal morbidity (SMM).

The study included 403,602 pregnancies, with a mean age of 30.3 years, with data collected from Kaiser Permanente Southern California, a large integrated health care organization. Within the cohort, there were 3,446 cases of SMM (0.9%) over 10 years (2008 to 2018). Temperature values during pregnancy were assigned to individuals based on their geocoded home addresses.

Long-term heat exposure was measured by the proportions of heat days during pregnancy, categorized as moderate, high, and extreme heat days. The study observed significant associations between long-term heat exposure during pregnancy and SMM, particularly related to environmental heat exposure in the third trimester.

Short-term heat wave exposure during the last gestational week was assessed using nine different heat wave definitions based on temperature thresholds and durations. Short-term associations were significant under different heat wave definitions. The magnitude of associations generally increased from the least severe to the most severe heat wave exposure, with more significant associations observed with more severe heat exposure.

According to the Centers for Disease Control and Prevention, SMM "...includes unexpected outcomes of labor and delivery that result in significant short- or long-term consequences to a woman's health. Using the most recent list of indicators, SMM has been steadily increasing in recent years."

The researchers found an association between when pregnancies begin (the season of conception) and severe maternal morbidity (SMM). The authors mention that mothers who started pregnancy in the cold season (November through April) were more vulnerable to heat exposure and had higher associations between heat exposure and SMM compared to those who started pregnancy in the warm season (May to October).

This suggests that the timing of conception, leading to the stage of pregnancy during the hottest months, may influence the relationship between heat exposure and SMM.

The study concludes that both long-term and short-term maternal heat exposure during pregnancy is associated with a higher risk of severe maternal morbidity. These results have important implications for SMM prevention, especially considering climate change's current and future impacts.

The study also highlights the health disparities among mothers with different education levels. This suggests the need for targeted interventions to reduce SMM risk, particularly among mothers with low socioeconomic status.

Anqi Jiao et al, Analysis of Heat Exposure During Pregnancy and Severe Maternal Morbidity, JAMA Network Open (2023). DOI: 10.1001/jamanetworkopen.2023.32780

Comment by Dr. Krishna Kumari Challa on September 12, 2023 at 9:01am

What is maternal morbidity?

The World Health Organization defines maternal morbidity as any health condition attributed to and/or aggravated by pregnancy and childbirth that has negative outcomes to the woman’s well-being.

Comment by Dr. Krishna Kumari Challa on September 10, 2023 at 12:11pm

Mysterious shiny orb seen on seafloor off Alaska

Using a robotic arm, the researchers gently nudged the object, determining that it was quite soft, before collecting it via suction for further study. DNA analysis will be conducted to pin down the organism responsible for its creation.

Comment by Dr. Krishna Kumari Challa on September 8, 2023 at 9:32am

Chitin from crustaceans, insects, mushrooms engages the immune system during digestion

Digesting a crunchy critter starts with the audible grinding of its rigid protective covering—the exoskeleton. Unpalatable as it may sound, the hard cover might be good for the metabolism, according to a new study in mice.

The researchers found in mice that digesting chitin, an abundant dietary fiber in insect exoskeletons and also mushrooms and crustacean shells, engages the immune system. An active immune response was linked to less weight gain, reduced body fat and a resistance to obesity. 

The researchers found that a particular arm of the immune system also is involved in chitin digestion. Stomach distention after chitin ingestion activates an innate immune response that triggers stomach cells to ramp up production of enzymes, known as chitinases, that break down chitin. Of note, chitin is insoluble—incapable of being dissolved in liquid—and thus requires enzymes and harsh acidic conditions to digest.

The study  results show that chitin activates immune responses in the absence of bacteria.

The stomach cells change their enzymatic output through a process we refer to as adaptation. But it is surprising that this process is happening without microbial input, because bacteria in the gastrointestinal tract are also sources of chitinases that degrade chitin.

The research team found that the greatest impact on obesity in mice occurred when chitin activated the immune system but was not digested. Mice fed a high fat diet also were given chitin. Some mice lacked the ability to produce chitinases to break down chitin. The mice that ate chitin but couldn't break it down gained the least amount of weight, had the lowest body fat measurements and resisted obesity, compared with mice that didn't eat chitin and with those that did but could break it down.

If the mice could break down chitin, they still benefited metabolically, but they adapted by overproducing chitinases to extract nutrients from chitin.

 Do-Hyun Kim et al, A type 2 immune circuit in the stomach controls mammalian adaptation to dietary chitin, Science (2023). DOI: 10.1126/science.add5649. www.science.org/doi/10.1126/science.add5649

Comment by Dr. Krishna Kumari Challa on September 8, 2023 at 9:24am

Device to monitor transplanted organs detects early signs of rejection

Researchers have developed the first electronic device for continuously monitoring the health of transplanted organs in real time.

Sitting directly on a transplanted kidney, the ultrathin, soft implant can detect temperature irregularities associated with inflammation and other body responses that arise with transplant rejection. Then, it alerts the patient or physician by wirelessly streaming data to a nearby smartphone or tablet.

In a new study, the researchers tested the device on a small animal model with transplanted kidneys and found the device detected warning signs of rejection up to three weeks earlier than current monitoring methods. This extra time could enable physicians to intervene sooner, improving patient outcomes and well-being as well as increasing the odds of preserving donated organs, which are increasingly precious due to rising demand amid an organ-shortage crisis.

Surabhi R. Madhvapathy et al, Implantable bioelectronic systems for early detection of kidney transplant rejection, Science (2023). DOI: 10.1126/science.adh7726. www.science.org/doi/10.1126/science.adh7726

Comment by Dr. Krishna Kumari Challa on September 7, 2023 at 3:06pm

India's Lunar Lander Has Detected 'Movement' on The Moon: But Is It Seismic Activity?

India's Chandrayaan-3 mission may have just recorded the first seismic data on the Moon since the 1970s. If confirmed to be natural seismic data, it could finally help scientists understand how the Moon's insides are arranged. The rumblings were recorded by the Vikram lander's onboard Instrument for Lunar Seismic Activity (ILSA). It's the first Micro Electro Mechanical Systems (MEMS) technology-based instrument on the Moon and it was was able to record the seismic rumbles of the mission's Pragyan rover moving around on the surface. But it also picked up what could be a natural event, such as a quake or an impact.

ILSA's primary objective is to measure ground vibrations generated by natural quakes, impacts, and artificial events. The vibrations recorded during the rover's navigation on August 25, 2023, are depicted in the figure," the Indian Space Research Organisation (ISRO) wrote in a statement.

Additionally, an event, seemingly natural, recorded on August 26, 2023, is also shown. The source of this event is currently under investigation.

This is tremendously exciting; to date, the best seismic data we have for the Moon was that collected by the Apollo program in the late 1960s and 1970s. Scientists have been itching to get their hands on more since we still don't know how the Moon's inner layers are arranged . Seismic data would go a long way to resolving that.

Even though it's only been a few weeks since ISRO landed on the Moon, it's already conducted a bunch of scientific observations and detected the first elements at the south pole.

Now both lander and rover are currently in sleep mode. That's because it's now night where they are on the Moon, which lasts 14 days or so.

Vikram and Pragyan, like other lunar missions before them, are solar powered, which means they "sleep" at night, when their batteries can't recharge.
Vikram and Pragyan will emerge from slumber on 22 September, when they will recommence their explorations of the mysterious south pole of the Moon.

Source: ISRO

Comment by Dr. Krishna Kumari Challa on September 7, 2023 at 2:59pm

What Was the First Animal to Evolve a Brain?

In the absence of a precise definition of brain, pinning down its origins is difficult. But scientists have a theory.

Having a brain is so necessary to human experience that it’s almost impossible to imagine any life without it. However, many living organisms don’t have brains, and going back far enough in time will lead to an ancestor of our own that was equally brainless. So, when exactly did brains evolve?

Scientists home in on the brain’s evolutionary origins by sorting out the animals without brains. Sponges have no neurons, so they are easy to discount, and while the more sophisticated jellyfish and sea anemones have a network of neurons, they have no central neural “headquarters” characteristic of a brain. 

About 600 million years ago, another group of animals evolved that had bilateral symmetry, meaning that they had a front and a back. “The front is where the nervous system crystallizes because that’s the bit of the animal that’s meeting the environment head on”. The first brain-like mass of neurons likely evolved at the front end of a long, thin, worm-like animal. Everything else that descended from that has a descendent of that neutral structure.

Today, there are many species, including some invertebrates such as the octopus, with brains that work similar to ours. These brains control perception, behaviour, and higher functions like memory. They are complex and wondrous, and they all evolved from a clump of neurons in the head of a worm.

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