Japanese researchers reported yesterday that injections of bone marrow cells into the calf muscles of people with peripheral artery disease helped increase capillary growth compared with injections of harmless saline. The study, which is the first to randomly test bone marrow injections against saline, found that 31 of 45 people who received the bone marrow cell injections showed an improvement in ankle-to-leg blood pressure as early as four weeks after treatment, suggesting better blood flow because of the new capillaries. Walking pain and leg and foot ulcers also steadily declined throughout the 24-week study, the team reported. The findings point to "the clinical efficacy of growing new blood vessels using bone marrow cell transplantation," said lead author Hiroya Masaki, associate professor of laboratory medicine and clinical sciences at Kansai Medical University in Osaka.