Bone paste promises castless union
A new "bone paste" that can be injected directly into bones, where it hardens in minutes, could dramatically improve treatment for the more than 1.5 million Americans who break their bones every year. The material, called Norian SRS, becomes as strong as real bone about 12 hours after injections, says its inventor, Brent R. Constantz, CEO of the Norian Corp., Cupertino, CA. Now under trial nationwide, the material can hold together splintered bones, fill gaps in bones caused by osteoporosis, or reinforce metal plates and screws used for severely broken bones. When injected into broken bones, Constantz explains, SRS becomes "completely interpenetrated" with the bone. When the bone-destroying cells begin to secrete acid to eat away bone, the acid also eats away the SRS, effectively ridding the body of the foreign substance. The material, Constantz believes, has significant advantages over other bone "glues" now in use. One, called PMMA (polymethylmethacrylate), has proved highly useful in joint replacement surgery, but less effective for broken bones. Ceramic products and injections of ground-up bone tissue from the patient's body do not provide the strength and structure the SRS apparently can. FAX (408) 252-3355.
Painless intracranial pressure measures tested
Scientists at NASA's Ames Research Center, Mountain View, CA, have under test two diagnostic devices to measure pressure inside the head, or intracranial pressure (ICP)-without penetrating the skull or skin. If successful, the tests would help determine whether increased ICP contributes to headaches, nasal congestion, and space motion sickness. One device, developed by Dr. John Cantrell and Dr. Tom Yost at NASA's Langley Research Center, transmits an ultrasound wave through the front of the skull to a small disk secured to the forehead. The wave passes through the brain tissue, reflects off the opposite side of the skull, and is received by a sensor in the disk for measurement. The second technique uses a very light mechanical stimulus applied to the forehead that is transferred through the skull and received by sensors on the scalp. Changes in pressure inside the head can be measured by examining changes in the response signal. Scientific Atlanta of Atlanta, and CytoProbe Corp., San Diego, developed this system. FAX Ann Hutchison at (415) 604-6999.
Spider silk could replace torn ligaments
An athlete with a torn ligament receives an artificial ligament in an operation that leaves no scar. Several weeks later, the athlete is back on the field with a knee as strong as before. Such an operation could become routine one day, according to Randy Lewis, a professor of molecular biology at the University of Wyoming Laramie. The creature that could make this possible: the spider. Spiders produce different kinds of silk. Lewis has singled out dragline silk that spiders use for the outer framework of their webs for his work. Gram for gram, Lewis says, dragline silk's tensile strength is greater than that of steel. Lewis has isolated the two proteins that make up the silk. They are somewhat unique in how they are held together. While most proteins are bonded with chemical links, spider-silk proteins