Researchers have uncovered a new way that some bacteria survive when under siege by antibiotics.

This survival mechanism is fundamentally different from other known bacterial strategies. Understanding it may be useful for designing drugs that target hard-to-treat bacterial strains such as drug-resistant tuberculosis (TB), an increasingly urgent public health problem. The study is based on Mycobacterium smegmatis—a cousin of the microbe that causes TB—and its response to the TB drug isoniazid.

In October 2009, a Science report that patients with chronic fatigue syndrome (CFS) were infected with XMRV attracted a great deal of attention, but subsequent studies could not confirm this finding. Now, a new study in the 22 September edition of ScienceExpress reports that the lab tests used to detect the retrovirus called XMRV in patients with chronic fatigue syndrome are unreliable. The study is accompanied by a partial retraction of the original Science paper.

Researchers have figured out a way to grow a ready-made supply of blood vessels for transplant into patients undergoing heart surgery, reports a new study in the journal Science Translational Medicine.

The blood vessels, or “vascular grafts,” can be made ahead of time, so surgeons can grab them off the shelf when patients need them. Until now, no other vascular graft engineered from human tissue has tolerated simple storage.