Here’s your weekly roundup of hot medical news!

Mending a broken heart with stem cells and microRNAs

Just like a deep wound causes a scar to form on the skin’s surface, the damage sustained during a heart attack can lead to scarred heart tissue. This scar tissue does not pump blood, putting more strain on the remaining normal muscle and leading to heart disease and failure. Currently, this condition is treated through implantable devices and, if necessary, heart transplant. Earlier this year, a study tracked the success of a technique that uses a patient’s own cardiac stem cells to repair damaged heart muscle. However, the latest development in repairing damaged heart muscles does not use stem cells at all, but rather turns scar tissue into heart muscle with microRNAs.

Controversial bird flu research finally published

A controversial study of the H5N1 bird flu virus has been published in the journal Nature. The study, and similar one that will be published in Science, sparked an international furor when it was accepted for publication, sparking concerns that the work, which included mutating H5N1 to be transmissible among mammals, could inspire bioterrorism. In the wild, bird flu is deadly, but does not spread easily between humans. In the published study, Yoshihiro Kawaoka and his colleagues at the University of Wisconsin–Madison, mutated the virus’ haemagglutinin (HA) gene, which produces a protein the virus uses to attach to host cells. The researchers found that the virus was able to spread among ferrets in different cages after just four mutations.

Genetic therapy for HIV effective in patients for over a decade

A new study has proven the long-term success of treating HIV patients with genetically modified T cells. Patients who received infusions of their own T cells, which had been genetically modified to kill HIV-infected cells, were found to be healthy up to 11 years after initial therapy. "We have 43 patients and they are all healthy," senior author Carl June, a professor of Pathology and Laboratory Medicine at Penn Medicine, said. "And out of those, 41 patients show long term persistence of the modified T cells in their bodies. Patients now have to take medicine for their whole lives to keep their virus under control, but there are a number of gene therapy approaches that might be curative."

Brain networks associated with teen drug use and ADHD

Teenage deaths in the industrialized world are often caused by impulsive, risky behaviors associated with alcohol and drug use. Robert Whelan and Hugh Garavan of the University of Vermont, and colleagues, conducted an imaging study of the brain of 1,896 14-year-olds, wherein they discovered that differences in brain networks precede drug and alcohol use. Network inactivity in the orbitofrontal cortex is associated with experimentation with alcohol, cigarettes and illegal drugs in early adolescence while network inactivity in another area is associated with attention-deficit hyperactivity disorder (ADHD). Both ADHD and early drug use are associated with poor inhibitory control, the capacity to put brakes on impulses in the brain. According to Garavan, “understanding brain networks that put some teenagers at higher risk ... could have large implications for public health.”