Comment

Comment by Dr. Krishna Kumari Challa on April 15, 2025 at 8:38am

'Ozone-climate penalty' adds to India's air pollution

India's cities are already ranked among the world's most polluted, based on concentrations of fine particulate matter in the air. Now new research indicates they are battling rising levels of another life-threatening pollutant—surface ozone.

A study published in the journal Global Transitions says deaths from ozone in India exceeded 50,000 in 2022 and caused losses of around US$16.8 billion—about 1.5 times the government's total health spending that year.

Surface ozone is a toxic gas that not only affects public health but also impacts ecosystems and climate due to the greenhouse effect.

Ozone, a variant of oxygen, occurs at ground level as well as in the upper atmosphere. Formed naturally, the ozone in the stratosphere helps filter out harmful ultraviolet rays that are a part of the sun's radiation. However, surface ozone, also called ground-level ozone, is generated by interactions between pollutants. For example, nitrogen oxides found in vehicular exhaust can react with volatile organic compounds released by industrial activity and waste dumps to produce ozone. Surface ozone is the primary component of smog and can have negative effects on human health and the environment.

Short-term exposure to ozone increases the risk of death from heart disease, stroke, hypertension and respiratory issues, while long-term exposure may decrease lung capacity, induce oxidative stress, suppress immune response and cause lung inflammation.

Climate change, rising temperatures and altered weather patterns can raise surface ozone in a phenomenon described by experts as the "ozone-climate penalty". Factors that affect ozone generation include solar radiation, humidity, precipitation and the presence of precursors—substances that lead to the formation of a pollutant through a chemical reaction—such as methane, nitrogen oxides and volatile organic compounds.

Ozone pollution increases during the hot summer months and declines during the monsoon period from June to September as heavy rains wash out the pollutants, and reduced solar radiation limits photochemical reactions.

Critically, human exposure to fine particulate matter—known as PM_2.5—may worsen the health effects of ozone. 

PM_2.5 refers to particles smaller than 2.5 microns, which can enter the bloodstream through the lungs.

According to the 2024 World Air Quality Report, 11 of the world's 20 cities carrying the highest burden of PM_2.5 are in India.

A study (1) published in The Lancet Planetary Health found that the whole of the population of India lives in areas where PM_2.5 levels exceed WHO guidelines.

Part 1

Comment by Dr. Krishna Kumari Challa on April 13, 2025 at 2:10pm

Venom characteristics of a deadly snake depends on climate .... and can be predicted from local climate

Local climate can be used to predict the venom characteristics of a deadly snake that is widespread in India, helping clinicians to provide targeted therapies for snake bite victims, according to a study published in PLOS Neglected Tropical Diseases

Russell's viper (Daboia russelii) is found across the Indian subcontinent and is responsible for over 40% of snake bite-related deaths in India each year. Its venom is extremely variable, and snake bites cause different symptoms in different regions of India.

The toxic effects of snake venom are caused by the concentrations of different enzymes, which can be influenced by many factors, including prey availability and climate. However, the factors driving variation in Russell's viper venom are unknown.

To investigate, researchers analyzed venom samples from 115 snakes collected in 34 locations across India. They tested the activity of venom toxins, including enzymes that break down proteins, phospholipids and amino acids.

Next, they used historical climate data to understand the relationship between venom composition and the local climate where the snakes were caught. They found that temperature and rainfall partly explained regional variation in snake venom composition.

Protease activity showed the closest relationship to climate variables, whereas the activity of amino acid oxidases was unaffected by climate. Snakes in drier regions of India tended to have higher protease activity.

The researchers used this data to create a map of expected venom types across Russell's viper's range in India, which could be used to predict the clinical symptoms of snake bites in different regions.

The venom maps developed in this study could help clinicians select the most appropriate treatment for patients with snake bites, or to develop targeted therapies such as toxin-specific antibodies, the researchers say.

PLOS Neglected Tropical Diseases (2025). DOI: 10.1371/journal.pntd.0012949

Comment by Dr. Krishna Kumari Challa on April 12, 2025 at 3:41pm

Researchers identify simple rules for folding the genome

An international team of researchers have identified rules that tell cells how to fold DNA into the tightly packed, iconic X-shaped chromosomes formed during mitosis that help ensure the accurate passing of genetic information between cells during cell division.

Published in the journal Science, these findings illuminate basic biological functions underlying mitosis on a micrometer scale. Understanding how the cells accomplish this critical task may provide important new insights into inheritance and DNA stability and repair, as well as genetic mutations that lead to human diseases such as cancer.

 Kumiko Samejima et al, Rules of engagement for condensins and cohesins guide mitotic chromosome formation, Science (2025). DOI: 10.1126/science.adq1709

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Comment by Dr. Krishna Kumari Challa on April 10, 2025 at 11:38am

While often discussed as two main types, diabetes actually encompasses several categories, including type 1, type 2, gestational diabetes, and other specific types like MODY (Maturity-Onset Diabetes of the Young).
Here's a breakdown of the main types of diabetes:
Type 1 Diabetes:
An autoimmune condition where the body's immune system mistakenly attacks and destroys the insulin-producing cells in the pancreas.
Type 2 Diabetes:
A condition where the body becomes resistant to insulin, and the pancreas may not produce enough insulin to maintain normal blood sugar levels.
Gestational Diabetes:
A form of diabetes that develops during pregnancy, often due to hormonal changes that make the body less sensitive to insulin.
Other Specific Types of Diabetes:
MODY (Maturity-Onset Diabetes of the Young): A genetic form of diabetes that typically develops in childhood or early adulthood, often before the age of 25.
LADA (Latent Autoimmune Diabetes in Adults): A type of diabetes that is similar to type 1 but develops more slowly, with the damage to the insulin-producing cells in the pancreas happening gradually.
Neonatal Diabetes: A rare form of diabetes that occurs in newborns or infants.
Secondary Diabetes: Diabetes that develops as a result of other medical conditions or medications, such as cystic fibrosis, pancreatitis, or corticosteroid use.

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Comment by Dr. Krishna Kumari Challa on April 10, 2025 at 11:37am

Research leads to designation of new type of diabetes: Type 5

Malnutrition-related diabetes—typically affecting lean, malnourished teens and young adults in low- and middle-income countries—is now officially recognized as a distinct form of the disease, known as type 5 diabetes.

Diabetes that is caused by obesity, known as type 2 diabetes, accounts for the majority of diabetes cases in developing countries. But increasingly young people are being diagnosed with diabetes caused not by too much food but by too little—by malnutrition, in other words. Type 5 diabetes is estimated to affect 20-to-25 million people worldwide, mainly in Asia and Africa.

Doctors are still unsure how to treat these patients, who often don't live for more than a year after diagnosis.

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Comment by Dr. Krishna Kumari Challa on April 10, 2025 at 11:33am

Handheld electro-shockers can pose risk for individuals with cardiac implants, study finds

Research has found that handheld electro-shockers commonly used for self-defense can potentially interact with cardiac implantable electronic devices (CIEDs) such as pacemakers, putting individuals at risk.

The study in Heart Rhythm shows that the individual interactive risk is primarily based on the applied voltage, but also on the manufacturer and type of implanted CIED.

The use of TASER pistols by security forces has been controversial because of associated health risks for subjects receiving a TASER shock. In contrast to TASER pistols, which shoot electrical darts over a distance of up to 10 meters and transmit electrical currents through large parts of a person's body, a handheld electro-shocker delivers energy superficially by directly applying the device to a target.

The handheld electro-shockers tested in this study are legal to own and carry in most countries and therefore, patients with CIEDs might have an increased risk of coming into contact with these devices. This is the first time a study has evaluated the effects of these electro-shockers on CIEDs.

Effects of handheld electro-shockers on cardiac implantable electronic devices, Heart Rhythm (2025). DOI: 10.1016/j.hrthm.2025.02.025

Comment by Dr. Krishna Kumari Challa on April 10, 2025 at 11:24am

Study finds pet dogs pose significant threat to wildlife and ecosystems

New research into the overlooked environmental impact of pet dogs has found far-reaching negative effects on wildlife, ecosystems and climate.

While ecological damage caused by cats has been extensively studied, the new research found dogs, as the world's most common large carnivores, present a significant and multifaceted environmental threat.

The paper, "Bad Dog? The environmental effects of owned dogs," has been published in Pacific Conservation Biology.

The research found that human-owned, pet dogs disturb and directly harm wildlife, particularly shorebirds, even when leashed.

As well as predatory behavior like chasing wildlife, dogs leave scents, urine and feces, which can disrupt animal behavior long after the dogs have left. Studies have found that animals like deer, foxes and bobcats  are less active or completely avoid areas where dogs are regularly walked, even in the absence of the dogs.

Dog waste also contributes to pollution in waterways and inhibits plant growth, while wash-off from chemical treatments used to clean and guard dogs from parasites can add toxic compounds to aquatic environments. In addition, the pet food industry, driven by a vast global dog population, has a substantial carbon, land and water footprint.

Addressing these challenges required a careful balance between reducing environmental harm and maintaining the positive role of dogs as companions and working animals, say the researchers.

The sheer number of pet dogs globally, combined with uninformed or lax behaviors by some owners, is driving environmental issues that we can no longer ignore.

Bad Dog? The environmental effects of owned dogs, Pacific Conservation Biology (2025). doi.org/10.1071/PC24071

Comment by Dr. Krishna Kumari Challa on April 10, 2025 at 10:47am

A total of 173 newborns with antenatal opioid exposure and 96 unexposed controls were recruited from four sites across the United States. All infants were born at or after 37 weeks of gestation and underwent brain MRI scans before eight weeks of age.

Three-dimensional volumetric MRI scans were acquired during natural sleep using Siemens and Philips 3T scanners. Volumetric data were analyzed using covariance models that controlled for postmenstrual age at scan, sex, birth weight, maternal smoking, and maternal education.

Opioid-exposed newborns had significantly smaller total brain volume compared to unexposed controls: 387.51 cm3 vs. 407.06 cm3. Reductions were also found in cortical gray matter: 167.07 cm3 vs. 176.35 cm3, deep gray matter: 27.22 cm3 vs. 28.76 cm3, white matter: 159.90 cm3 vs. 166.65 cm3, cerebellum: 23.47 cm3 vs. 24.99 cm3, and brainstem: 6.80 cm3 vs. 7.18 cm3.

Amygdala volume was also reduced in opioid-exposed infants. Left amygdala volume measured 0.48 cm3 compared to 0.51 cm3 in controls. Right amygdala volume measured 0.51 cm3 vs. 0.55 cm3 in controls.
Methadone-exposed newborns showed significantly smaller white matter volume. Buprenorphine-exposed newborns showed significantly smaller right amygdala volume.

Newborns exposed to opioids only and those exposed to opioids plus other substances both exhibited significant reductions in cortical and deep gray matter, cerebellum, brainstem, right amygdala, and total brain volume. Polysubstance-exposed newborns also showed reductions in white matter and the left amygdala.
Researchers concluded that antenatal opioid exposure is associated with reductions in global, regional, and tissue-specific brain volumes in newborns. Structural differences were observed across multiple brain regions and varied by type of opioid exposure.

Methadone exposure was linked with reduced white matter volume. Buprenorphine exposure was associated with smaller right amygdala volume. Newborns with polysubstance exposure showed volume reductions in additional areas, including white matter and the left amygdala.

According to the authors, these structural brain differences may represent early biomarkers of later neurodevelopmental dysfunction.

Yao Wu et al, Antenatal Opioid Exposure and Global and Regional Brain Volumes in Newborns, JAMA Pediatrics (2025). DOI: 10.1001/jamapediatrics.2025.0277

Nethra K. Madurai et al, Following the Developing Brain Affected by Opioid Exposure, JAMA Pediatrics (2025). DOI: 10.1001/jamapediatrics.2025.0274

Part 2

Comment by Dr. Krishna Kumari Challa on April 10, 2025 at 10:45am

In utero opioid use associated with smaller brain regions in newborns

Researchers have found that newborns exposed to opioids in utero exhibited smaller brain volumes in multiple regions compared to unexposed infants.

Cortical gray matter, white matter, deep gray matter, cerebellum, brainstem, and the amygdala all showed reduced size, indicating possible early markers of neurodevelopmental impairment.

Opioid exposure affects a growing number of pregnancies in the world. An estimated 7% of pregnant individuals report using opioids during pregnancy. These substances cross the placenta and may interfere with fetal brain development.

Antenatal opioid exposure has been linked to lower infant cognitive and language scores, increased rates of attention-deficit/hyperactivity disorder, and difficulties with executive functioning.

Confounding influences such as socioeconomic status, co-exposure to other substances, parenting environment, and genetic factors complicate any direct causal interpretation. In some studies, once these environmental risks are controlled, associations between opioid exposure and neurodevelopmental outcomes weaken or disappear.

In the study, "Antenatal Opioid Exposure and Global and Regional Brain Volumes in Newborns," published in JAMA Pediatrics, researchers conducted a multisite, prospective observational study.

Part 1

Comment by Dr. Krishna Kumari Challa on April 10, 2025 at 8:58am

The researchers gathered interesting new insights about the effects of general anesthesia on the brain and its unique patterns of neural activity. In the future, the results of their study could inspire further cross-species research looking at the brain before, during and after the administration of anesthetics, which could in turn inform the development of interventions to facilitate the rehabilitation of both people and animals after medical procedures that require anesthesia.
The researchers hope that by learning how the brain reboots consciousness after anesthesia, they can learn how to help recovery of consciousness in patients who suffer from coma and other forms of chronic unconsciousness after a brain injury.

Andrea I. Luppi et al, General anaesthesia decreases the uniqueness of brain functional connectivity across individuals and species, Nature Human Behaviour (2025). DOI: 10.1038/s41562-025-02121-9

Part 2

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