Roundup: First New Class of Antibiotics in Decades; Smoking Linked to Brain Shrinkage; and More News

MIT Researchers Identify New Class of Antibiotics Using Type of Artificial Intelligence

Researchers with the Massachusetts Institute of Technology (MIT) have discovered new compounds -- essentially the first new class of antibiotics in several decades -- that can kill a drug-resistant bacterium responsible for more than 10,000 deaths in the U. S. every year.

In a study published in Nature, the researchers indicated that these compounds could kill methicillin-resistant Staphylococcus aureus (MRSA) grown in a lab dish and in two mouse models of MRSA infection. "The compounds also show very low toxicity against human cells, making them particularly good drug candidates," MIT said in a statement.

A key innovation of the new study is that the researchers used a type of artificial intelligences (AI) known as “deep learning.” The compounds were identified using AI models that can learn to identify "chemical structures" that are associated with antimicrobial activity. "These models then sift through millions of other compounds, generating predictions of which ones may have strong antimicrobial activity," MIT stated.

“The insight here was that we could see what was being learned by the models to make their predictions that certain molecules would make for good antibiotics. Our work provides a framework that is time-efficient, resource-efficient, and mechanistically insightful, from a chemical-structure standpoint, in ways that we haven’t had to date,” said James Collins, the Termeer Professor of Medical Engineering and Science at MIT’s Institute for Medical Engineering and Science (IMES), in a statement.

MRSA, which infects more than 80,000 people in the U.S. every year, often causes skin infections or pneumonia. Severe cases can lead to sepsis, a potentially fatal bloodstream infection.

Over the past several years, Mr. Collins and his colleagues in MIT’s Abdul Latif Jameel Clinic for Machine Learning in Health (Jameel Clinic) have begun using deep learning to try to find new antibiotics. Their work has yielded potential drugs against other drug-resistant bacteria.

Smoking can Cause Brain Shrinkage, But Quitting Could Stop Further Loss, New Study Finds

The many health hazards of smoking, the primary cause of lung cancer, are mounting as new research finds that smoking can shrink the brain.

Researchers at Washington University School of Medicine in St. Louis also found that quitting smoking prevents further loss of brain tissue. However, stopping smoking doesn’t restore the brain to its original size, they also concluded. The new study’s findings, published in Biological Psychiatry: Global Open Science, help shed light on why smokers are at high risk of age-related cognitive decline and even Alzheimer’s disease.

“Up until recently, scientists have overlooked the effects of smoking on the brain, in part because we were focused on all the terrible effects of smoking on the lungs and the heart,” said senior author Laura J. Bierut, M.D., the Alumni Endowed Professor of Psychiatry, in a statement. “But as we’ve started looking at the brain more closely, it’s become apparent that smoking is also really bad for your brain.”

Scientists have previously known that smoking and shrinking brain volume are linked, but have yet to be clear on a cause. The role of genetics is another factor. Brain size and smoking behavior are heritable. About half of a person’s risk of smoking can be attributed to his or her genes, the study’s authors said.

For the study, data was analyzed from the UK Biobank, a publicly available biomedical database that contains genetic, health and behavioral information on half a million people, mostly of European descent. A subset of more than 40,000 UK Biobank participants underwent brain imaging, which can be used to determine brain volume. In total, the team analyzed de-identified data on brain volume, smoking history and genetic risk for smoking for 32,094 people, states a news release on the study.

Researchers calculated the number of smoking years for individuals who reported smoking one pack or 20 cigarettes daily. Their brain scans were compared to people who never smoked or smoked fewer than 100 cigarettes.

Those who smoked more experienced a higher level of brain shrinkage, the researchers found.

“You can’t undo the damage that has already been done, but you can avoid causing further damage,” explained the study’s first author, Yoonhoo Chang, a graduate student, in a statement. “Smoking is a modifiable risk factor. There’s one thing you can change to stop aging your brain and putting yourself at increased risk of dementia, and that’s to quit smoking.”

‘Light Physical Activity’ Could be Vital in Reversing Childhood Obesity, Says International Study