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Comment by Dr. Krishna Kumari Challa on November 17, 2023 at 11:25am

Researchers help reduce lead levels in Madagascar drinking water

A team of engineers and public health experts helped residents reduce their exposure to lead—a major global environmental pollutant that causes more than 1 million premature deaths each year. By combining efforts to replace water pumps and educate city technicians, these researchers helped decrease the blood lead levels of 87 percent of the children tested during their study.

The lead concentrations of the water from the pumps exceeded the World Health Organization's recommended limit of lead in drinking water—10 micrograms per liter. In some cases, the water contained more than 10 times the recommended limit.

The families and children are drinking this water and using it to cook their meals.

In low- and middle-income countries, there is a lack of regulations and understandings of the harmful effects of lead, as well as other comorbidities, such as improper nutrition, that can increase childhood lead absorption.

The pumps are the primary source of water for more than three-quarters of the coastal area of Madagascar, where there are about 9,000 pumps because tap water is not always affordable or available for the city's 280,000 people. 

Part 1

Comment by Dr. Krishna Kumari Challa on November 17, 2023 at 10:47am

How cell identity is preserved when cells divide

Every cell in the human body contains the same genetic instructions, encoded in its DNA. However, out of about 30,000 genes, each cell expresses only those genes that it needs to become a nerve cell, immune cell, or any of the other hundreds of cell types in the body.

Each cell's fate is largely determined by chemical modifications to the proteins that decorate its DNA; these modification in turn control which genes get turned on or off. When cells copy their DNA to divide, however, they lose half of these modifications, leaving the question: How do cells maintain the memory of what kind of cell they are supposed to be?

A new MIT study proposes a theoretical model that helps explain how these memories are passed from generation to generation when cells divide. The research team suggests that within each cell's nucleus, the 3D folding pattern of its genome determines which parts of the genome will be marked by these chemical modifications.

After a cell copies its DNA, the marks are partially lost, but the 3D folding allows each daughter cell to easily restore the chemical marks needed to maintain its identity. And each time a cell divides, chemical marks allow a cell to restore its 3D folding of its genome. This way, by juggling the memory between 3D folding and the marks, the memory can be preserved over hundreds of cell divisions.

 Jeremy A. Owen et al, Design principles of 3D epigenetic memory systems, Science (2023). DOI: 10.1126/science.adg3053. www.science.org/doi/10.1126/science.adg3053

Comment by Dr. Krishna Kumari Challa on November 17, 2023 at 10:32am

Bear genes show circadian rhythms even during hibernation

The internal clocks of grizzly bears appear to keep ticking through hibernation, according to a genetic study. This persistence highlights the strong role of circadian rhythms in the metabolism of many organisms including humans.

The genetic study confirmed observational evidence that bears' energy production still waxes and wanes in a daily pattern even as they slumber for several months without eating. The researchers also found that during hibernation the amplitude of the energy production was blunted, meaning the range of highs and lows was reduced. The peak also occurred later in the day under hibernation than during the active season, but the daily fluctuation was still there.  

This underscores the importance of the circadian rhythms themselves—that they give organisms the flexibility to still function in a state as extreme as a hibernating bear.

Other research has shown that circadian rhythms, the 24-hour physical cycles common to most living animals on Earth, have ties to metabolic health. In humans, major disruptions to these patterns, such as occur in night shift work, have been linked to metabolic problems like weight gain and higher prevalence of diabetes.

Ellery P. Vincent et al, Circadian gene transcription plays a role in cellular metabolism in hibernating brown bears, Ursus arctos, Journal of Comparative Physiology B (2023). DOI: 10.1007/s00360-023-01513-5

Comment by Dr. Krishna Kumari Challa on November 17, 2023 at 10:06am

One of the reasons ECT isn't more popular is that for a lot of people, it's easier and more convenient to just take a pill. However, in people for whom medications don't work, electroconvulsive therapy can be life-saving. Understanding how it works will help us discover ways to increase the benefits while minimizing side effects.

The researchers used electroencephalography (EEG) scans to study the brain activity of patients who received ECT therapy for depression. They also looked at another similar form of treatment called magnetic seizure therapy, which induces a seizure with magnets instead of electrodes. Both therapies showed increased aperiodic activity levels in patients' brains post-treatment.

One of the functions of aperiodic activity in the brain is helping control how neurons turn on and off. Our neurons are constantly going through cycles of excitation and inhibition that correspond with different mental states. Aperiodic activity helps boost inhibitory activity in the brain, effectively slowing it down.

Something we see regularly in the EEG scans of people who receive electroconvulsive or magnetic seizure therapy is a slowing pattern in the brain's electrical activity. This pattern has gone unexplained for many years, but accounting for the inhibitory effects of aperiodic activity helps explain it. It also suggests that these two forms of therapy are causing similar effects in the brain.

 Translational Psychiatry (2023). doi.org/10.1038/s41398-023-02631-y

Translational Psychiatry (2023). doi.org/10.1038/s41398-023-02634-9

Part 2

Comment by Dr. Krishna Kumari Challa on November 17, 2023 at 10:04am

New studies of brain activity explain benefits of electroconvulsive therapy

Electroconvulsive therapy (ECT), formerly known as electroshock therapy, involves inducing a brief seizure in the brain using controlled doses of electricity. While ECT is highly effective for certain mental illnesses, particularly depression, the reasons for its efficacy have long puzzled the fields of psychiatry and neuroscience.

Now, researchers  may have an answer. In two new studies published in Translational Psychiatry, they propose a new hypothesis that ECT alleviates depression symptoms by increasing aperiodic activity, a type of electrical activity in the brain that doesn't follow a consistent pattern and is generally considered to be the brain's background noise.

Electroconvulsive therapy has a great track record, but a bad reputation. The therapy is effective in up to 80% of patients who receive the treatment, most often for depression but occasionally for bipolar disorder or schizophrenia. However, despite this high success rate, electroconvulsive therapy is frequently associated with frightening images of people receiving painful, high voltage shocks.

A lot of people are surprised to learn that doctors still use electroconvulsive therapy, but the modern procedure uses highly controlled dosages of electricity and is done under anesthesia. It really doesn't look like what you see in movies or television.

While generally safe and effective, ECT does have drawbacks, including temporary confusion and cognitive impairment. It also requires multiple outpatient visits, which can present a barrier to some people who might otherwise benefit from the treatment.

Part 1

Comment by Dr. Krishna Kumari Challa on November 17, 2023 at 9:56am

1.3 million lives lost every year in just seven countries: The devastating impact of tobacco revealed

Every year 1.3 million lives are lost to cancers caused by smoking tobacco across the UK, US and BRICS nations (Brazil, Russia, India, China and South Africa), according to a new study.

Researchers have found that together, the seven countries represented more than half of the global burden of cancer deaths every year. They concluded that smoking, as well as three other preventable risk factors—alcohol, overweight or obesity, and human papillomavirus (HPV) infections—caused almost 2 million deaths combined.

Researchers concluded that the four preventable risk factors resulted in over 30 million years of life lost each year. Smoking tobacco had by far the biggest impact—leading to 20.8 million years of life being lost, the study said.

Some of the other key findings from the study include:

• Preventable risk factors were associated with different cancer types in different places. For example, in India, there were more premature deaths from head and neck cancer in men, and gynecological cancer in women, but in every other country, tobacco smoking caused the most years of life to be lost to lung cancer.

• Researchers believe that this is due to differences in each of the countries—cervical screening is less comprehensive in India and South Africa than in other countries like the UK and US, which would explain why there are more premature deaths from gynecological cancers due to HPV infection in India and South Africa. The higher number of years of life lost to head and neck cancer in men in India could be explained by smoking habits being different to those in the UK, with the general population smoking different tobacco products.

• There are gender differences in the number of cancer deaths and years of life lost to different risk factors. Men have higher rates of years of life lost to smoking and drinking alcohol, because smoking and drinking rates tend to be higher in men. In China, India and Russia, rates of years of life lost to tobacco smoking and alcohol were up to nine times higher in men than women.

• Meanwhile, being overweight or obese, and HPV infection, led to more cancer deaths and years of life lost in women than in men. In South Africa and India, HPV led to particularly high rates of years of life lost with a large gender imbalance. Rates were 60 times higher in women than men in South Africa, and 11 times higher in India, which highlights the urgent need for improved access to cervical screening and the HPV vaccination in these countries.

• The differences in cancers linked to HPV infection are stark—mortality rates are six times higher in South Africa than in the UK and US. Cervical cancer has been largely prevented by screening in the UK and US, and is on track to be almost eliminated through HPV vaccination in the UK.

International burden of cancer deaths and years of life lost from cancer attributable to four major risk factors: a population-based study in Brazil, Russia, India, China, South Africa, the United Kingdom, and United States, eClinicalMedicine (2023).

Comment by Dr. Krishna Kumari Challa on November 17, 2023 at 7:36am

Kelsey's ultrasound shows both of her uteruses with a baby in each. Source: (doubleuhatchlings/Instagram)

part2

Comment by Dr. Krishna Kumari Challa on November 16, 2023 at 11:41am

1 in 50 Million Chance: US Woman With Rare Double Uterus Is Pregnant in Both

 A 32-year-old woman from Alabama who was born with two uteruses is now pregnant in both.

Kelsey Hatcher, who is documenting her story on her Instagram account "doubleuhatchlings," knew from the age of 17 she has "uterus didelphys," a rare condition where a person has a double uterus, thought to affect about 0.3 percent of females.

It was during a routine eight-week ultrasound visit in May that the mother-of-three learned not only that she was having twins this time around – but that a fetus was present in each of her uteruses.

Most likely what happened is that she ovulated separately and had one egg come down each fallopian tube, meaning coming down on each side of the uterus, and then sperm traveled up on each separate uterus and fertilization occurred separately, according to her doctors. Both the fetuses are healthy.

Pregnancies in both uteruses are exceedingly rare – the odds were 1 in 50 million – with the last widely known case occurring in Bangladesh in 2019 when Arifa Sultana, then 20, gave birth to healthy twins 26 days apart.​

But the uteruses will contract at different times, which could be minutes, hours or even days apart, and the woman and her husband  are aware Cesarean sections – for one, or both – could be needed, depending on how things unfold.

Source: 

Agence France-Presse

part1

Comment by Dr. Krishna Kumari Challa on November 16, 2023 at 11:34am

50 Years of Data Links Insecticides to Global Decline of Human Sperm Counts: Meta Analysis

Insecticide exposure has been linked to lower sperm concentration in adult men worldwide, according to a new review of 25 studies spanning almost 50 years. The research team  says it's the most thorough systematic review of the topic so far.

These are strong findings as their method takes into account each study's limitations, so their published paper recommends reducing exposure to the two types of insecticides studied to preserve male fertility and increase the changes of parenthood.

people are primarily exposed to insecticides through the consumption of contaminated food and water.

These commonly-used insecticides' main mode of toxicity is the inhibition of enzymes involved in the normal breakdown of neurotransmitters like acetylcholine.

"No matter how you looked at it, the smaller studies or the larger studies, there was a consistent association with increased exposure to insecticides associated with decreased sperm concentration", according to the researchers.

The researchers note other studies have shown that semen quality is declining over time. A review in 2022 found that the average sperm count among participants, who were not considered infertile dropped by 51 percent between 1973 and 2018, from 101.2 million to 49 million per millilitre of semen.

There's a correlation between low sperm concentration and other factors of male health too, such as an increased risk of some cancers. However, finding two things to be related doesn't prove that one is responsible for or a result of the other, and we still don't know the mechanism behind the effects.

https://ehp.niehs.nih.gov/doi/10.1289/EHP12678

Comment by Dr. Krishna Kumari Challa on November 16, 2023 at 9:56am

Researchers discover alternative cosmic source of gold

Researchers have discovered that the explosion of a low-mass neutron star can be the alternative cosmic source for lanthanides and other heavy elements, including precious metals such as gold and platinum.

Neutron stars are the evolutionary end points of stars with a mass between 10 to 25 times that of the sun. After the final explosion, the star leaves behind a compact object with a mass comparable to the sun, and a diameter of about 20 km (the size of Manhattan). Such a compact object is stable enough to exist alone. But in a binary neutron star system, the interaction with the companion neutron star can trigger something dramatic. Traditionally, when two neutron stars are close enough, they merge and collide. This process is the major source of lanthanides and heavy elements in the universe. The collision can create the condition (known as the r-process) for the synthesis of these elements. The merger event was recently observed for the first time in 2017. However, it is highly uncertain if this channel alone is sufficient to explain the heavy elements in the cosmic scale. The team noticed that even without direct collision, the primary neutron star can lose mass to its companion neutron star by tidal force. Theoretical models expect that after shedding sufficient mass, the star becomes unstable, and it triggers uncontrolled pulsation and the later explosion.

The new results  confirm that the individual low mass neutron star is unstable, and it can explode. The chemical composition of the ejecta closely resembles the solar composition, especially in heavy elements. This suggests that this scenario could be another important method to explain the chemical element distribution in the universe.

This study sheds light on one of the fundamental questions about the universe: where all the chemical elements come from, and how did the universe evolve from only hydrogen and helium to a diversity of 118 elements. Lanthanides have close relations with modern technology. For example, neodymium is the main ingredient for manufacturing strong magnets. Heavy elements including precious metals, i.e., gold and platinum, are also abundantly produced by this channel.

 Chun-Ming Yip et al, R-process Nucleosynthesis of Subminimal Neutron Star Explosions, The Astrophysical Journal (2023). DOI: 10.3847/1538-4357/acf570

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