These fish hold clues to human eyesight … and other health news [video]

What do spinach leaves, zebrafish and 3-D printing have in common? They all are involved with the latest medical advances to help people around the world live longer, healthier lives.

Check out some of the latest developments in health technology below.

Cultivating new heart tissue

Transforming a spinach leaf into human heart tissue is close to reality. Scientists at the Worcester Polytechnic Institute in Massachusetts discovered that human cells can grow over the vein-streaked structure of a spinach leaf and build a working system of vessels.

The findings are important because repairing the tiny networks of delicate blood vessels needed to deliver oxygen is almost impossible.

“We have a lot more work to do, but so far this is very promising,” Glenn Gaudette, the study’s co-author, told National Geographic.

Fishy secrets for repairing eyesight

Scientists went underwater to find a new way to repair retinas. James Patton of Vanderbilt University in Tennessee discovered that the zebrafish, a small tropical fish native to southeast Asia, can regain sight after being blinded.

The retinas of zebrafish are almost identical to those of humans. Patton’s team has identified a promising chemical that might explain the fish’s regenerative abilities, and plans to test the findings with mice and then humans.

Print a kidney, prep for surgery

Doctors at the University of Rochester in New York have found a way to simulate complex surgeries with 3-D printed organs that look and feel like the real thing.

Using a patient’s own medical scans, surgeons can print exact models of organs and muscles and assemble them into replicas for practice. Experienced surgeons can attempt complicated techniques, and medical students can gain experience on hydrogel models before working with patients.

“While pilots have simulators that allow them to spend hours of training in a realistic environment, there really is no lifelike equivalent for surgeons,” said Ahmed Ghazi of the University of Rochester. Until now.

Stopping a top killer in hospitals

There’s new hope for treating sepsis, a deadly condition in which the body’s efforts to fight an infection also damage its own organs. Typically one-third of all patients who develop sepsis die.

Facing a patient with a dire case, Dr. Paul Marik of Sentara Norfolk General Hospital in Virginia tried something different: He treated the patient with an infusion of corticosteroids and vitamin C. The unconventional treatment worked for her, and for almost all of Marik’s next 50 patients with sepsis.

While the results must be confirmed with controlled studies, the treatment, which costs about as much as a dose of antibiotics, is a positive step in the fight against a top killer.

Reprogramming cells to fight disease

Cells as computers? Scientists at Boston University have enabled cells to respond to logical instructions by “programming” a protein that cuts, moves and splices strands of DNA.

Pharmaceutical companies are using this process to teach immune cells to better detect cancerous tissue.

April 7 is World Health Day.