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Comment by Dr. Krishna Kumari Challa on November 1, 2024 at 11:11am

What is unusual is that women who are generally overweight and gain a lot of weight during pregnancy usually have an increased risk of giving birth to large babies. This also applies to women who develop gestational diabetes.

On average, women with PCOS have higher BMIs, gain more weight during pregnancy, and 25 percent develop gestational diabetes. However, the outcome is the opposite: these women give birth to babies who are smaller than average. We still don't know why, but we see that the placenta is affected in these women.
Even though the placenta in these women is smaller in size, it seems to deliver more nutrients relative to the baby's body weight compared to a normal placenta. It is a placenta in overdrive.
The placenta delivers nutrients to the baby through the umbilical cord. In women with PCOS, we see that the placenta is generally smaller in size. At the same time, it must provide everything the baby needs, so it has to work very hard to meet these demands. Sometimes, however, the placenta can't keep up, which can lead to placental insufficiency and, in rare cases, fetal death.
There are no definitive answers tot eh question "why"?
Previously, researchers thought the cause was linked to the high levels of male sex hormones, but they have not been able to fully connect the two. Researchers also know that women with PCOS have a slightly different immune profile during pregnancy.
The researchers have also followed up on some of the children when they were 7 years old. They saw that the children born to mothers with PCOS generally had more central obesity, meaning they were larger around the waist.

Other studies have shown that children born to mothers with PCOS are at higher risk of developing overweight and obesity at a young age. Research has also shown that low birth weight is linked to the development of type 2 diabetes and cardiovascular disease later in life.
We see differences in children as early as seven or eight years old, where children born to mothers with PCOS have a larger waist circumference and higher BMI.

Maren Sophie Aaserud Talmo et al, Growth Restriction in the Offspring of Mothers With Polycystic Ovary Syndrome, JAMA Network Open (2024). DOI: 10.1001/jamanetworkopen.2024.30543

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Part 2

Comment by Dr. Krishna Kumari Challa on November 1, 2024 at 11:06am

Obesity combined with polycystic ovary syndrome in mothers poses risk to children

Women with polycystic ovary syndrome (PCOS) and obesity are at a higher risk of giving birth to smaller babies in terms of birth weight, length, and head circumference, according to a recent study conducted.

 

One in eight women is affected by the hormone disorder PCOS. PCOS is commonly characterized by elevated levels of male sex hormones, infrequent or irregular menstrual periods, and the formation of small cysts on the ovaries.

In the study, 390 children born to women with PCOS were compared to around 70,000 children from the Norwegian Mother, Father and Child Cohort Study (MoBa).

The researchers found that on average, the babies born to mothers with PCOS weighed less, were shorter, and had a smaller head circumference  at birth. This was particularly the case when the mothers were obese, meaning they had a BMI over 30.

The findings are published in the journal JAMA Network Open.

PCOS is a disease that follows women throughout their lives and can trigger different metabolic diseases and problems such as diabetes, high blood pressure, and obesity. Women with PCOS are generally more likely to develop overweight and obesity.

In women of normal weight who have PCOS, researchers only find that their children have a lower birth weight compared to women who do not have PCOS. Instead, the group of children born to mothers with obesity stands out the most. These babies weigh less, are shorter and have a smaller head circumference. Obesity places an additional burden on mothers who have PCOS as well as their children.

Part 1

Comment by Dr. Krishna Kumari Challa on November 1, 2024 at 10:42am

Causal relationship seen between GERD and hypertension

There is a positive causal relationship between gastroesophageal reflux disease (GERD) and hypertension, according to a study published online Sept. 23 in Frontiers in Cardiovascular Medicine.

Researchers  investigated the causal  between GERD and hypertension using a two-sample Mendelian randomization analysis.

The researchers reported that a total of 16 single nucleotide polymorphisms strongly associated with GERD were screened out, and the inverse variance weighting suggested a causal relationship between GERD and hypertension (odds ratio, 1.057). A similar relationship was seen using a weighted median (odds ratio, 1.051). No heterogeneity or horizontal pleiotropy was seen, suggesting a robustness of the outcome.

"Although the specific mechanism was not elucidated, this study provides another perspective on the risk factors for the development of hypertension," the authors write. "Timely diagnosis and treatment of GERD can significantly improve and reduce the development of associated hypertension and deserves further research and application."

Weige Li et al, Study of the causal relationship between gastroesophageal reflux disease and hypertension through two-sample Mendelian randomization analysis, Frontiers in Cardiovascular Medicine (2024). DOI: 10.3389/fcvm.2024.1326348

Comment by Dr. Krishna Kumari Challa on November 1, 2024 at 10:21am

Low sugar intake in utero and in early childhood found to significantly reduce risk of midlife chronic disease

A low-sugar diet in utero and in the first two years of life can meaningfully reduce the risk of chronic diseases in adulthood, a new study has found, providing compelling new evidence of the lifelong health effects of early-life sugar consumption.

Published in Science, the study finds that children who experienced sugar restrictions during their first 1,000 days after conception had up to 35% lower risk of developing type 2 diabetes and as much as 20% less risk of hypertension as adults. Low sugar intake by the mother prior to birth was enough to lower risks, but continued sugar restriction after birth increased the benefits.

 Tadeja Gracner et al, Exposure to sugar rationing in the first 1000 days of life protected against chronic disease, Science (2024). DOI: 10.1126/science.adn5421

Comment by Dr. Krishna Kumari Challa on November 1, 2024 at 10:16am

Scientists engineer 'glowing' gel to improve eye surgery

Cataracts—a condition that causes clouding of the eye's lens and deteriorating vision—will affect nearly everyone who lives long enough. Now  scientists have pioneered a new color-changing hydrogel that could reduce complications from cataract surgery, one of the world's most commonly performed procedures.

During cataract surgery, doctors remove the cloudy lens and replace it with an artificial one. The procedure requires injecting a clear hydrogel to keep the eye inflated and protect the cornea. However, incomplete removal of this gel can lead to increased eye pressure, pain, and even long-term vision loss.

Researchers have created a clear gel that turns fluorescent green under blue light, allowing surgeons to verify complete removal following surgery. This innovation could enhance both the safety and efficiency of cataract surgery and other eye procedures, according to the researchers.

Now, when surgeons finish up a case, they can rest assured that all the gel has been removed versus beforehand when they just had to do their best and hope they'd gotten it all.

Their results were featured on the cover of the Journal of Cataract & Refractive Surgery.

 Erick E. Rocher et al, Fluorescein-conjugated hyaluronic acid enables visualization of retained ophthalmic viscosurgical device in anterior chamber, Journal of Cataract & Refractive Surgery (2024). DOI: 10.1097/j.jcrs.0000000000001503

Comment by Dr. Krishna Kumari Challa on November 1, 2024 at 10:01am

It's time to rewrite the textbooks: 

Chemists just broke a 100-year-old rule

I love this!

Chemists have found a big problem with a fundamental rule of organic chemistry that has been around for 100 years—it's just not true. And they say, It's time to rewrite the textbooks.

Organic molecules, those made primarily of carbon, are characterized by having specific shapes and arrangements of atoms. Molecules known as olefins have double bonds, or alkenes, between two carbon atoms. The atoms, and those attached to them, ordinarily lie in the same 3D plane. Molecules that deviate from this geometry are uncommon.

The rule in question, known as Bredt's rule in textbooks, was reported in 1924. It states that molecules cannot have a carbon-carbon double bond at the ring junction of a bridged bicyclic molecule, also known as the "bridgehead" position. The double bond on these structures would have distorted, twisted geometrical shapes that deviate from the rigid geometry of alkenes taught in textbooks.

Olefins are useful in pharmaceutical research, but Bredt's rule has constrained the kind of synthetic molecules scientists can imagine making with them and prevented possible applications of their use in drug discovery.

A paper published by scientists in the journal Science has invalidated that idea. They show how to make several kinds of molecules that violate Bredt's rule, called anti-Bredt olefins, or ABOs, allowing chemists to find practical ways to make and use them in reactions.

People aren't exploring anti-Bredt olefins because they think they can't (very bad for science).

"We shouldn't have rules like this—or if we have them, they should only exist with the constant reminder that they're guidelines, not rules. It destroys creativity when we have rules that supposedly can't be overcome", say the scientists.

What this study shows is that contrary to one hundred years of conventional wisdom, chemists can make and use anti-Bredt olefins to make value-added products.

There's a big push in the pharmaceutical industry to develop chemical reactions that give three-dimensional structures like these because they can be used to discover new medicines.

Luca McDermott et al, A solution to the anti-Bredt olefin synthesis problem, Science (2024). DOI: 10.1126/science.adq3519. www.science.org/doi/10.1126/science.adq3519

Comment by Dr. Krishna Kumari Challa on November 1, 2024 at 8:59am

Part 2

Comment by Dr. Krishna Kumari Challa on November 1, 2024 at 8:55am

Bats have acoustic cognitive maps

Echolocating bats have been found to possess an acoustic cognitive map of their home range, enabling them to navigate over kilometer-scale distances using echolocation alone.

This finding, published in Science, was demonstrated by researchers.

Would you be able to instantly recognize your location and find your way home from any random point within a three-kilometer radius, in complete darkness, with only a flashlight to guide you?

Echolocating bats face a similar challenge, with a local and directed beam of sound—their echolocation—to guide their way. Bats have long been known for their use of echolocation to avoid obstacles and orient themselves.

The researchers have now shown that bats can identify their location even after being displaced and use echolocation to perform map-based navigation over long distances.

Remarkably in experiments, even with echolocation alone, 95% of the displaced bats  returned to their roosts within minutes, demonstrating that bats can conduct kilometer-scale navigation using only this highly directional, and relatively local, mode of sensing. However, it was also shown that, when available, bats improve their navigation using vision.

The model created revealed that bats tend to fly near environmental features with higher "echoic entropy"—areas that provide richer acoustic information.

Bats can use this acoustic information to distinguish between environmental features such as a tree and a road, and thus use them as acoustic landmarks.

After being displaced, these  bats first identify their new location and then fly home, using environmental features with distinctive acoustic cues as landmarks. This behaviour suggests they possess an acoustic mental map of their home range.

Aya Goldshtein, Acoustic cognitive map-based navigation in echolocating bats, Science (2024). DOI: 10.1126/science.adn6269. www.science.org/doi/10.1126/science.adn6269

Comment by Dr. Krishna Kumari Challa on October 31, 2024 at 11:55am

Once again, tuberculosis becomes world's top infectious disease killer

In the highest tally ever recorded for tuberculosis cases, the World Health Organization report that over 8 million people worldwide were diagnosed with the lung disease last year.

Of that number, 1.25 million people died of TB, the new report found, meaning that it is once again the leading cause of deaths from infectious disease after COVID-19 displaced it briefly during the pandemic.

The fact that TB still kills and sickens so many people is an outrage, when we have the tools to prevent it, detect it and treat it," WHO Director-General Dr. Tedros Adhanom Ghebreyesus said in an agency news release. "WHO urges all countries to make good on the concrete commitments they have made to expand the use of those tools, and to end TB."

Some countries are hit harder by the disease than others. It continues to mostly affect people in Southeast Asia, Africa and the Western Pacific. India, Indonesia, China, the Philippines and Pakistan account for more than half of the world's cases, the WHO noted.

According to the report, 55% of people who developed TB were men, while 33% were women and 12% were children and young adolescents. Many new TB cases were driven by five major risk factors: undernutrition, HIV infection, alcohol use disorders, smoking [especially among men] and diabetes.

Tackling these issues, along with other social determinants such as poverty, requires a coordinated approach, the WHO added.

https://www.who.int/news/item/29-10-2024-tuberculosis-resurges-as-t...

Comment by Dr. Krishna Kumari Challa on October 31, 2024 at 11:47am

Electric fans fail to lower core body temperature of seniors during heat waves, study finds

A team of physiologists at the University of Ottawa's Human and Environmental Physiology Research Unit reports that use of an electric fan during periods of high temperatures by older people does not lower core body temperatures. In their study, published in JAMA, the group conducted experiments with elderly volunteers using fans in high-temperature conditions.

As several heat waves have struck parts of North America, high numbers of older people have died of heat stroke. This was notable due to the location of many of the deaths—the Pacific Northwest, where extremely high temperatures are rare. Because of the rarity of such high temperatures, many people in the region do not have air conditioners. Prior research has shown that older people are at higher risk of dying of heat stroke due to their lessened ability to reduce their body temperature. One notable problem is less efficient sweating.

During heat waves, officials in the affected regions suggested that older people without access to air conditioning use electric fans to stay cool. In this new effort, the research team tested the approach to see if the advice was valid.

The researchers recruited 18 people ranging in age from 65 to 72, who sat in a climate-controlled temperature chamber with an electric fan. The temperature and the fan settings were both controlled by the research team. All the volunteers were monitored during the experiments to ensure they did not become overheated.

The researchers kept the temperature inside the chamber at a steady 36°C, with a humidity level of 45%. The fans had three spin settings: off, slow and fast. All three settings were tested with the volunteers.

The researchers found that neither the slow nor the fast setting had any measurable impact on core body temperature—it was the same as if the fan was off. They also found that the slow setting did little to make the volunteers feel cooler, but the fast setting did, which, they suggest, was dangerous. Because they felt somewhat cool, the volunteers did not realize that their core body temperatures might be rising to dangerous levels.

 Fergus K. O'Connor et al, Effect of Electric Fans on Body Core Temperature in Older Adults Exposed to Extreme Indoor Heat, JAMA (2024). DOI: 10.1001/jama.2024.19457

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