Medical Notes: Week of May 31, 2020

A newly developed smartphone app is remarkably effective at predicting if a person is infected with Covid-19. Then biomarkers for ALS or Lou Gehrig’s disease can be found in a person’s teeth in the first decade of life. Then, a study shows that changing the way physical therapy is done can improve strength by an additional 30 percent. And finally, The labels on drinks for kids don’t help adults figure out which ones are real fruit juice and which are sugary, artificially flavored imitations.

Far too few tests are available for Covid-19 right now. But a newly developed smartphone app is remarkably effective at predicting if a person is infected. The app, relies on people telling the app every day whether they have a cough, a loss of smell or taste, fatigue, and if they’ve been skipping meals. That information over time allows the app to be 80 percent accurate on whether a person is Covid-positive. The journal Nature Medicine says those who come up positive can get help more quickly, self-quarantine, and start tracking contacts. The app is called the “Covid symptom study app” and it’s available at the Apple App Store or Google Play.

Symptoms for the degenerative disease ALS or Lou Gehrig’s disease usually don’t show up until middle age. But a study in the Annals of Clinical and Translational Neurology has found biomarkers for the disease in a person’s teeth in the first decade of life. Scientists at Mount Sinai in New York used lasers to map what are called growth rings in the teeth… and discovered that those who go on to develop ALS metabolize metals differently than those who won’t develop the disease. Scientists hope to create preventive pathways with the new knowledge.

People who tear a ligament may never get back to their previous strength, even with reconstruction and aggressive physical therapy. Those who tear an ACL in the knee, for example, often lose up to 40 percent of their muscle. But now a study in the Journal of Athletic Training shows that changing the way physical therapy is done can improve strength by an additional 30 percent. The key is using “eccentric” exercise, like the downward swing of a bicep curl rather than the upswing. Therapists have feared the injury potential of eccentric exercise… but the study found very little risk.

And finally…a study that confirms what you probably already knew. The labels on drinks for kids don’t help adults figure out which ones are real fruit juice and which are sugary, artificially flavored imitations. The study in the American Journal of Public Health calls on the FDA to change its rules to give parents some help.