CDC modifies contact time for close contact with COVID-19 recommendations because of prison guard infections; A superspreader event in Boston was a biotech conference in February; Dr. Dawn proposes distributing patriotic flag masks to counter the anti-mask crowd; Avastin drug improves smooth knee cartilage regrowth from cartilage stem cell injections; Improvements in stem cell treatments for Parkinson's disease; Longevity and other side effects of metals in dental implants; About scintillating scotomas, with and without migraine headaches; Drugs to avoid if you have the fast heart rate condition, Wolff-Parkinson-White syndrome; Discussion of the safety of air travel in the COVID-19 world; Telehealth comments and an explanation of the problems of bisphosphonates to treat osteoporosis; Exciting new discovery of a pair of salivary glands in the back of the throat! Sensitivities for cancer linked to cell phones may depend on particular SNPs; Certain genetic variations in the immune system explain more extreme reactions to Coronavirus in children