TOP MEDICAL NEWS 12/August/2022

Here are the top medical news for the day:

How the ovarian reserve is established

Researchers define the epigenetic machinery that governs the establishment and function of the mammalian ovarian reserve, providing molecular insights into female reproductive health and lifespan, in a new study published in Nature Communications.

"In human females over the age of 35, you see a decline in fertility," said lead researcher of the paper. "Our study may give us the foundation to understand how female fertility is established and maintained at the molecular level and why it declines with age."

Ref:

Satoshi Namekawa et. al, PRC1-mediated epigenetic programming is required to generate the ovarian reserve, Nature Communications, 10-Aug-2022, DOI: 10.1038/s41467-022-31759-6

Higher risk of dementia if an upper heart chamber is abnormal

Structural or functional abnormalities within the heart's left atrium, with or without symptoms, may increase a person's risk of developing dementia later in life by 35%, according to new research published in the Journal of the American Heart Association. Dementia risk increased even among those who did not experience atrial fibrillation or stroke, two conditions known to be associated with dementia.

Atrial cardiopathy is associated with an increased risk of stroke and atrial fibrillation, which are both linked to an enhanced risk of dementia. In a study led by Michelle C. Johansenthe research team aimed to determine the relationship between atrial cardiopathy and dementia, and if so, whether it is independent of atrial fibrillation and stroke.

Ref:

Michelle C. Johansen et. al, Risk of Dementia Associated With Atrial Cardiopathy: The ARIC Study, Journal of the American Heart Association, DOI: 10.1161/JAHA.121.025646

New drug candidate fights off more than 300 drug-resistant bacteria

Gram-negative bacteria are especially difficult to treat because they have strong defense systems – tough cell walls that keep most antibiotics out and pumps that efficiently remove those antibiotics that get inside. The microbes can also mutate to evade multiple drugs. Furthermore, treatments that do work aren't very specific, eradicating many kinds of bacteria, including those that are beneficial. So, Paul Hergenrother and colleagues wanted to design a drug that could infiltrate the defenses of gram-negative bacteria and treat infections, while leaving other helpful microbes intact.

The team started with an antibiotic that was active against gram-positive bacteria and made a series of structural modifications that they believed would allow it to act against gram-negative strains. One of the modified compounds, dubbed fabimycin, proved potent against more than 300 drug-resistant clinical isolates, while remaining relatively inactive toward certain gram-positive pathogens and some typically harmless bacteria that live in or on the human body.

Ref:

Paul Hergenrother et. al, An Iterative Approach Guides Discovery of the FabI Inhibitor Fabimycin, a Late-Stage Antibiotic Candidate with In Vivo Efficacy against Drug-Resistant Gram-Negative Infections, ACS Central Science, 10.1021/acscentsci.2c00598,10-Aug-2022

Surprising way in which Multiple sclerosis drug works

Cells that make myelin are sensitive to adenosine triphosphate (ATP) and nitric oxide (NO), molecules that are present in high amounts in the blood and brain lesions of MS patients. Red blood cells can release NO directly, but they can also stimulate NO production in the lining of blood vessels by releasing ATP. NO can then go on to damage nerves in MS patients.

Zinc, C-peptide — which is secreted by the pancreas along with insulin — and albumin are key players in the latter process, and they can latch onto red blood cells. Because interferon beta can bind zinc, it seemed possible that the drug helped patients by sopping up this mineral, so Dana Spence and colleagues wanted to investigate further.

Ref:

Dana Spence et. al, "Interferon-β Decreases the Hypermetabolic State of Red Blood Cells from Patients with Multiple Sclerosis", ACS Chemical Neuroscience,DOI: 10.1021/acschemneuro.2c00332 ,10-Aug-2022