Women are more prone to knee injuries than men, and the findings of a new study suggest this may involve more than just differences in muscular and skeletal structure - it shows that males and females also differ in the way they transmit the nerve impulses that control muscle force. Scientists at Oregon State University found that men control nerve impulses similar to individuals trained for explosive muscle usage - like those of a sprinter - while the nerve impulses of women are more similar to those of an endurance-trained athlete, like a distance runner. In particular, the research may help to explain why women tend to suffer ruptures more often than men in the anterior cruciate ligament of their knees during non-contact activities. These ACL injuries are fairly common, can be debilitating, and even when repaired can lead to osteoarthritis later in life.
Nanoscale Films Developed At MIT Promote Bone Growth, Creating A Stronger Seal Between Implants And Patients' Own Bone.
Every year, more than a million Americans receive an artificial hip or knee prosthesis. Such implants are designed to last many years, but in about 17 percent of patients who receive a total joint replacement, the implant eventually loosens and has to be replaced early, which can cause dangerous complications for elderly patients. To help minimize these burdensome operations, a team of MIT chemical engineers has developed a new coating for implants that could help them better adhere to the patient's bone, preventing premature failure. "This would allow the implant to last much longer, to its natural lifetime, with lower risk of failure or infection, " says Paula Hammond, the David H. Koch Professor in Engineering at MIT and senior author of a paper on the work appearing in the journal Advanced Materials.
A bacterium historically associated with cat scratch fever and transmitted predominately by fleas may also play a role in human rheumatoid illnesses such as arthritis, according to new research from North Carolina State University. Bartonella is a bacterium that is maintained in nature by fleas, ticks and other biting insects. It can be transmitted to humans both by these parasites as well as by bites or scratches from infected cats and dogs. The most commonly known Bartonella-related illness is cat scratch disease, caused by B. henselae, a species of Bartonella that can be carried in a cat's blood for months to years. In collaboration with Dr. Robert Mozayeni, a rheumatologist based in Maryland, and Dr. Ricardo Maggi, a research assistant professor at NC State, Dr. Ed Breitschwerdt, professor of internal medicine at NC State's College of Veterinary Medicine and adjunct professor of medicine at Duke University, tested blood samples from 296 patients for evidence of Bartonella infection.
Obesity and the painful autoimmune disorder rheumatoid arthritis are each becoming more common, raising a logical question: Could one have something to do with the other? For women, it appears there is a link, Mayo Clinic researchers say. They studied hundreds of patients and found a history of obesity puts women at significant risk of developing rheumatoid arthritis. Their findings are published online in the American College of Rheumatology journal Arthritis Care & Research. In rheumatoid arthritis, the immune system attacks tissues, inflaming joints and sometimes also affecting other organs and causing fever and fatigue. Rheumatoid arthritis tends to initially impact the hands and feet and then spread to the knees, ankles, hips and shoulders. It is more common in women than in men.
AUTOIMMUNITY Understanding bone loss in rheumatoid arthritis patients Rheumatoid arthritis causes joint stiffness and pain for over 2 million Americans. The disease is caused by an errant attack on healthy tissue by the body's immune system. Antibodies found in some patients target specific types of modified proteins, called citrullinated proteins, and are associated with an increased risk of bone destruction. Dr. Georg Schett and fellow researchers at University of Erlangen-Nuremberg in Germany suspected that these particular self-reactive antibodies directly influence bone loss that can sometimes occur in rheumatoid arthritis. They found that antibodies against citrullinated proteins bind to osteoclasts, specialized cells that break down bone tissue. In a mouse model system, they demonstrated that infusion of antibodies recognizing a cirtullinated protein activated osteoclasts and triggered bone resorption, resulting in the breakdown of bone and release of calcium.