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Science & Medicine News
Heart-Stopping Surgery
Surgeons are testing new
techniques and devices for minimally invasive heart surgery that will allow a
surgical team to work on a motionless heart. The system circumvents the need to
break the breast bone and create a large, painful chest opening. The new
procedure, which uses a technique known as port-access surgery, is unprecedented
because it allows the surgical team to stop the heart while repairing it, said
Dr. Bruce A. Reitz, head of the surgical team and chair of cardiothoracic
surgery. Reitz predicted that the new procedure could eventually shorten
recovery time and reduce pain after bypass surgery in about 30 percent of the
approximately 300,000 coronary artery bypasses performed annually in the United
States.
Tumor Growth
Stanford researchers and colleagues elsewhere have discovered a
cellular mechanism that provides important insight into how cancer evolves and
why some solid tumors are resistant to chemotherapy and radiation. Researchers
have known for roughly a decade that the cellular protein p53 has something to do
with controlling tumors. Now they have found that p53 works as an emergency brake
on cancer development by killing cells that attempt to proliferate in
oxygen-deficient regions of tumors. Cells with mutant forms of p53 have no such
brake, and as a result they can survive low-oxygen conditions, said Amato
Giaccia, assistant professor of radiation oncology at the medical school. The
discovery of this mechanism could lead to the development of more effective
cancer treatments, the researchers said. The research is described in the Jan. 4
Nature magazine.
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