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Comment by Dr. Krishna Kumari Challa on April 9, 2025 at 9:53am

Scientists make water-repellent replacement for toxic 'forever chemicals'

A team of international scientists has invented a substitute for synthetic chemicals, called PFAS (perfluoroalkyl substances), which are widely used in everyday products despite being hazardous to health and the environment.

Until now, it was believed fluorine—the element in such products which forms a highly effective barrier between substances like air and water, making them water repellent—could not easily be replaced because of its unique properties.

But scientists have discovered that the unique "bulky" attribute of fluorine, which makes it especially good at filling space, can actually be replicated in a different, non-toxic form. The findings are published in the Journal of Colloid and Interface Science.

From fire-fighting foam to furniture, food packaging and cookware, to make-up and toilet tissue, PFAS products are everywhere. Despite the risks to human health, and the fact they don't degrade, perfluoroalkyl substances persist in the environment, finding an alternative with comparable properties has proven elusive. But after many years of intensive research,  researchers have made a great breakthrough now. 

The results of their discovery are published in a study which unpacks the chemical structure of PFAS and pinpoints the characteristic "bulkiness" they sought to replicate in a safer form. It also demonstrates how non-fluorinated components, containing only non-toxic carbon and hydrogen, could be equally effective replacements.

Through extensive experimentation, it turns out these 'bulky' fragments feature in other common chemical systems like fats and fuels. So scientists took those principles and created modified chemicals which have these positive attributes and are also much safer.

Using their specialized laboratories for chemical synthesis, they substituted the fluorine in PFAS with certain groups containing only carbon and hydrogen. The whole process has taken about 10 years and the implications are very significant not least because PFAS is used in so many different products and situations.

The researchers now plan on using these principles discovered in the lab to design commercially viable versions of PFAS substitutes.

Masanobu Sagisaka et al, New fluorine-free low surface energy surfactants and surfaces, Journal of Colloid and Interface Science (2025). DOI: 10.1016/j.jcis.2025.03.018

Comment by Dr. Krishna Kumari Challa on April 8, 2025 at 11:58am

The gut microbiome as a predictive factor for kidney rejection

Kidney is one of the most  transplanted organs in the world. 

 For patients with advanced kidney failure, a kidney transplant remains the best treatment option.

The demand is correspondingly high:  several patients around the world  are on the waiting list for a kidney transplant. A serious risk for patients who have already received a transplant is rejection of the transplant. This is a defensive reaction of the body against the foreign tissue, which can lead to a complete loss of organ function in an emergency.

Why transplants are sometimes rejected and sometimes not depends largely on immune mechanisms. The causes are complex and often poorly understood. To help answer this question, researchers have analyzed the changes in the composition and function of the gut microbiome of kidney transplant patients .

They discovered an altered signature in the gut microbiome that preceded transplant rejection. This study, published in the American Journal of Transplantation, offers a possible starting point for recognizing the risk of rejection at an early stage.

Our gut is home to countless microorganisms that play an important role in how our immune system works. This is known as the microbiome. The majority of these, over 90%, are bacteria. These bacteria and the substances they produce communicate with our body—especially with the cells that protect us from disease. They therefore help to control and strengthen our immune system, which is important for both healthy and sick people.

In patients with chronic kidney disease, the composition of the gut microbiome is severely altered, resulting in lower concentrations of anti-inflammatory short-chain fatty acids (SCFA) and increased concentrations of pro-inflammatory metabolites from the microbiome.

In their study, researchers analyzed the changes in the composition and function of the gut microbiome of patients after kidney transplantation. They found changes in the gut microbiome that were already detectable before the transplant rejection reaction.

It was noticeable that in patients who showed a rejection reaction, bacteria that typically occur in patients with advanced kidney failure, such as Fusobacterium and disease-associated genera such as Streptococcus, increased again. This was not the case in the other group studied, the "non-rejection group."

Overall, the analyses showed that the production potential of short-chain fatty acids in the stool is reduced before kidney rejection. This is indicated by the reduced frequency of bacterial enzymes from which short-chain fatty acids are produced before rejection.

The previously observed dynamic regeneration of the microbiome after kidney transplantation may be significantly disturbed in the case of transplant rejection: prior to rejection, profound changes in the composition of the microbiome occur, characterized by reduced diversity and a low number of SCFA-producing bacterial populations.

The results suggest that the microbiome plays an important role in how the immune system reacts after a kidney transplant. This observation can help to identify the risk of transplant rejection at an early stage or perhaps influence it therapeutically .

Johannes Holle et al, Gut microbiome alterations precede graft rejection in kidney transplantation patients, American Journal of Transplantation (2025). DOI: 10.1016/j.ajt.2025.02.010

Comment by Dr. Krishna Kumari Challa on April 8, 2025 at 11:29am

Your season of conception could influence how your body stores fat

Individuals who were conceived in colder seasons are more likely to show higher brown adipose tissue activity, increased energy expenditure and a lower body mass index (BMI), and lower fat accumulation around internal organs, compared with those conceived in warmer seasons, suggests a study published in Nature Metabolism. The findings, based on an analysis involving more than 500 participants, indicate a potential role for meteorological conditions influencing human physiology.

Although eating habits and exercise are key indicators of fat loss, exposure to cold and warmth also plays a part. In colder temperatures, the body generates more heat (cold-induced thermogenesis) via brown adipose tissue activity and stores less fat in the form of white adipose tissue than it does in hotter temperatures.

Researchers analyzed brown adipose tissue density, activity and thermogenesis in 683 healthy male and female individuals between ages 3 and 78 in Japan, whose parents were exposed to cold temperatures (defined in the study as between 17 October and 15 April) or warm temperatures (between 16 April and 16 October) during the fertilization and birth periods.

Individuals who were conceived during the cold season showed higher brown adipose tissue activity, which then correlated with increased energy expenditure, increased thermogenesis, lower visceral fat accumulation and lower BMI into adulthood. More specifically,  the researchers show that a key factor in determining brown adipose tissue activity in human offspring is a large daily temperature variation and lower ambient temperature during the pre-conception period.

Takeshi Yoneshiro et al, Pre-fertilization-origin preservation of brown fat-mediated energy expenditure in humans, Nature Metabolism (2025). DOI: 10.1038/s42255-025-01249-2

Comment by Dr. Krishna Kumari Challa on April 8, 2025 at 11:24am

scientists discover babies can sense their heartbeat and breathing

Body signals such as heartbeat and breathing accompany us constantly, often unnoticed as background noise of our perception. Even in the earliest years of life, these signals are important as they contribute to the development of self-awareness and identity. But can babies  perceive their own body signals?

A recent study from Wiener Kinderstudien Lab at the University of Vienna demonstrates for the first time that babies as young as 3 months can perceive their own heartbeat. In addition, the team also investigated the first-time infants' perception of their own breathing and found developments during the first two years of life. The results are now published in the journal eLife.

The perception of internal body signals is closely linked to emotional awareness, mental health, and self-perception. Early in life, the ability to perceive one's own body signals may be particularly important, as it often forms the basis for interactions with caregivers—for example, babies rely on their caregivers to respond appropriately to signs of hunger or discomfort. Moreover, the development of self-awareness and identity partly depends on the perception and experience of one's own body.

The study shows that even 3-month-old babies can perceive their own heartbeat and that this ability remains relatively stable during the first two years of life. At the same time, the findings indicate that the perception of breathing improves significantly during the second year. Interestingly, the ability to perceive the heartbeat and breathing does not appear to be related—much like in adults.

Results showed that even at an early age, babies recognize the correspondence between their own heartbeat or breathing rhythm and the animated figures. 

Markus R Tünte et al, Respiratory and cardiac interoceptive sensitivity in the first two years of life, eLife (2023). DOI: 10.7554/eLife.91579

Comment by Dr. Krishna Kumari Challa on April 8, 2025 at 10:43am

Particularly noteworthy is the newly discovered bitter compound oligoporin D, which stimulates the bitter taste receptor type TAS2R46 even at the lowest concentrations (approx. 63 millionths of a gram/liter). To illustrate: the concentration corresponds to one gram of oligoporin D dissolved in about 106 bathtubs of water, where one gram corresponds approximately to the weight of a knife tip of baking soda.

 Lea M. Schmitz et al, Taste-Guided Isolation of Bitter Compounds from the Mushroom Amaropostia stiptica Activates a Subset of Human Bitter Taste Receptors, Journal of Agricultural and Food Chemistry (2025). DOI: 10.1021/acs.jafc.4c12651

Part 2

Comment by Dr. Krishna Kumari Challa on April 8, 2025 at 10:42am

Mushroom study identifies most bitter substance known to date

The molecular world of bitter compounds has so far only been partially explored. Researchers have now isolated three new bitter compounds from the mushroom Amaropostia stiptica and investigated their effect on human bitter taste receptors.

In doing so, they discovered one of the potentially most bitter substances known to date. The study results, published in the Journal of Agricultural and Food Chemistry, expand our knowledge of natural bitter compounds and their receptors, thus making an important contribution to food and health research.

The BitterDB database currently contains more than 2,400 bitter molecules. For about 800 of these very chemically diverse substances, at least one bitter taste receptor is specified. However, the bitter compounds recorded are mainly from flowering plants or synthetic sources. Bitter compounds of animal, bacterial or fungal origin, on the other hand, are still rarely represented in the database.

Researchers assume that bitter taste receptors have developed to warn against the consumption of potentially harmful substances. However, not all bitter compounds are toxic or harmful, and not every toxin tastes bitter, as the example of the death cap mushroom toxin shows. But why is that the case?

Studies have also shown that the sensors for bitter substances are not only found in the mouth, but also in organs such as the stomach, intestines, heart and lungs, as well as on certain blood cells. Since we do not "taste" with these organs and cells, the question arises as to the physiological significance of the receptors there.

Comprehensive data collections on bitter compounds and their receptors could help us to find answers to these open questions.

The more well-founded data we have on the various bitter compound classes, taste receptor types and variants, the better we can develop predictive models using systems biology methods to identify new bitter compounds and predict bitter taste receptor-mediated effects. This applies to both food constituents and endogenous substances that activate extraoral bitter taste receptors.

The research team that undertook this study examined the Bitter Bracket (Amaropostia stiptica) as part of a collaborative project. The mushroom is non-toxic, but tastes extremely bitter.

Using modern analytical methods, the research group  has succeeded in isolating three previously unknown compounds and elucidating their structures. Using a cellular test system, the researchers then showed that the compounds activate at least one of the approximately 25 human bitter taste receptor types.

Part 1

Comment by Dr. Krishna Kumari Challa on April 8, 2025 at 8:57am

Cox proportional hazards models were used to estimate the risk of each condition by obesity class, adjusting for sex, age, race or ethnicity, income, and education. Researchers also calculated population-attributable fractions for each condition by obesity class.

Obesity was present in 42.4% of the study population, including 21.2% with class I obesity, 11.3% with class II, and 9.8% with class III. Compared to those with normal weight, individuals with obesity were more likely to be female, Black, have lower income and education levels, and have higher blood pressure and waist-to-hip ratios.

Prevalence and incidence rates increased progressively with higher obesity classes for all 16 health outcomes. Observed associations with class III obesity were strongest for obstructive sleep apnea (hazard ratio 10.94), type 2 diabetes mellitus (7.74), and metabolic dysfunction–associated liver disease (6.72). Weaker associations were found for asthma (2.14), osteoarthritis (2.06), and atherosclerotic cardiovascular disease (1.96).

Obesity was associated with elevated risk across all subgroups, with consistent patterns by sex and race. Population-attributable fractions showed that obesity explained 51.5% of obstructive sleep apnea cases and 36.3% of metabolic liver disease cases, and 14.0% of all osteoarthritis cases in the study population were estimated to be attributable to obesity.

Increased risk, particularly at higher severity levels, was associated with all 16 health outcomes studied. Risks rose in a stepwise manner across obesity classes, with the highest burden observed among individuals with class III obesity. Findings remained consistent across demographic subgroups and were supported by data from a large, diverse national cohort.

Associations between obesity and several conditions such as sleep apnea, type 2 diabetes, liver disease, and heart failure were strong and statistically robust. Population-attributable fractions indicated that a substantial proportion of these conditions may be preventable through effective obesity management.

Zhiqi Yao et al, Associations between Class I, II, or III Obesity and Health Outcomes, NEJM Evidence (2025). DOI: 10.1056/EVIDoa2400229

Part 2

Comment by Dr. Krishna Kumari Challa on April 8, 2025 at 8:56am

Obesity severity tied to increased risk across 16 common conditions

New research has found that obesity, particularly severe obesity, is strongly associated with the incidence of 16 common health outcomes. Associations remained consistent across sex and racial groups. Strong associations were observed for obstructive sleep apnea, type 2 diabetes, and metabolic dysfunction-associated steatotic liver disease.

Obesity is a risk factor for adverse health outcomes involving multiple organ systems. Prior studies have analyzed conditions individually, limiting understanding of obesity's total health burden. External validity has also been limited by underrepresentation of individuals with class III obesity and of diverse demographic groups.

In the study, "Associations between Class I, II, or III Obesity and Health Outcomes," published in NEJM Evidence, researchers conducted a longitudinal cohort study to understand how different levels of obesity relate to a wide array of health conditions across a diverse U.S. population.

Participants contributed electronic health records, physical measurements, and survey data. Body mass index (BMI) was calculated at enrollment and used to classify individuals as normal weight, overweight, or obese, with further stratification into obesity classes I, II, and III.

Sixteen pre-identified health conditions were evaluated: hypertension, type 2 diabetes, hyperlipidemia or dyslipidemia, heart failure, atrial fibrillation, atherosclerotic cardiovascular disease, chronic kidney disease, pulmonary embolism, deep vein thrombosis, gout, liver disease linked to metabolic dysfunction, biliary calculus, obstructive sleep apnea, asthma, gastroesophageal reflux disease, and osteoarthritis.

Part 1

Comment by Dr. Krishna Kumari Challa on April 7, 2025 at 10:15am

Urban birds host drug-resistant bacteria

Indian cormorants (Phalacocorax fuscicollis) can spread antimicrobial-resistant bacteria in their droppings. Intrigued by the smell of cormorant droppings, veterinary microbiologist Siddhartha Narayan Joardar and his team analysed some of the bird poo and found a strain of E. coli that produced enzymes that helped it resist certain antibiotics. The birds probably pick up the bacterium by eating fish from ponds contaminated by human wastewater, the team suggests. “Growing evidence shows the presence of antimicrobial-resistant bacteria in common urban birds,” says Joardar, which poses a public health threat if it spills over into humans.

https://www.nature.com/articles/d44151-025-00042-0?utm_source=Live+...

https://www.ijah.in/upload/snippet/707_84.pdf

Comment by Dr. Krishna Kumari Challa on April 7, 2025 at 8:47am

When looking at specific dementia subtypes, all unmarried participants also showed reduced risk for Alzheimer's disease and Lewy body dementia. In contrast, no consistent associations were observed for vascular dementia or frontotemporal lobar degeneration in fully adjusted models. Divorced and never-married groups were also less likely to progress from mild cognitive impairment to dementia.

Risk patterns appeared slightly stronger among men, younger individuals, and participants referred to clinics by health professionals. Yet stratified analyses showed minimal variation, suggesting that the associations held across a wide range of demographic and clinical subgroups.

Researchers concluded that unmarried individuals, particularly those who were divorced or never married, had a lower risk of developing dementia than those who remained married. These associations persisted even after adjusting for physical and mental health, lifestyle factors, genetics, and differences in clinical referral and evaluation.
Alzheimer's disease and Lewy body dementia were higher in married participants. Risk of progression from mild cognitive impairment to dementia was also higher.
The findings contrast with prior studies linking unmarried status to increased dementia risk and offer new evidence on how relationship status may relate to cognitive outcomes when diagnosis is measured under standardized conditions.

Selin Karakose et al, Marital status and risk of dementia over 18 years: Surprising findings from the National Alzheimer's Coordinating Center, Alzheimer's & Dementia (2025). DOI: 10.1002/alz.70072

Part 2

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