In The News (10/06)
Bioengineered Cartilage Repairs Osteoarthritic Knees
Despite the debilitating erosion of cartilage in osteoarthritc knees, the disease¯at least in its early stages¯presents a positive environment for the formation of new cartilage when bioengineered cartilage is implanted. Researchers at the University of Bristol in the U.K. found that custom-made patches¯constructed of erythrocytes (red blood cells) isolated from healthy cartilage, cultured, seeded onto hyaluronic acid scaffolds, and grown for 14 days before implantation¯not only induced cartilage regeneration in as soon
as 11 months in injured knees, but they were even more effective in knees with early OA. In the study, 23 patients with chondral defects (a chipped bone resulting from a direct blow to a bent knee) received implants and were biopsied an average 16 months later. Implants in 10 of the 23 patients¯nine of whom had already developed OA¯exhibited the appearance of normal cartilage. Though it has long been believed that OA might inhibit the success of cartilage implants, researchers concluded that early-stage OA in fact appears to enhance the process.
Turn Off Pain? Just Flip The Switch
Though pain-killing drugs work wonders in providing relief from acute pain, they are largely ineffective in dealing with chronic, long-lasting pain. But here’s the good news. Researchers have discovered a “switch”¯a nerve-cell protein¯that effectively blocks chronic pain. Called protein kinases G(PKG), upon injury or inflammation PKG is turned on and activated. Once activated, molecules containing the protein set off other processes that send pain messages to the brain. As long as PKG remains on, pain persists. Conversely, turning PKG off relieves the pain. Early attempts at alleviating chronic pain have focused on “second order” neurons in the spinal cord that
relay pain messages to the brain. Since current drugs are unable to inhibit the activity of these neurons, researchers focused on the more accessible “first order” neurons in the body’s periphery that send messages to the spinal cord. According to the journal Neuroscience, investigators have applied for a patent to develop a new class of drugs that will not only turn on PKG, but inhibit it as well.
Diuretics Linked To Recurrent Gout Attacks
If you’ve ever suffered from gout, eliminate the diuretics. According to a report in the Journal of Rheumatology, recent use of diuretics (often prescribed for the treatment of hypertension and congestive heart failure) more than triples the risk of recurrent gout. In a study involving 197 patients who suffered a gout attack in the past year, those who used diuretics in the two days preceding an attack increased their risk of recurrent gout by 3.6-fold. Given the wide availability of other agents for the treatment of of hypertension and congestive heart failure, researchers recommend avoiding diuretics, particularly thiazide and loop diuretics, to reduce the risk of recurrent gout attacks.
Early Infliximab Treatment Cuts Costs Of RA
Though expensive ($2,500 for an average two-hour infusion), early treatment of rheumatoid arthritis with infliximab (Remicade) will offset its cost in the long run. So concludes a group of Finnish researchers who set out to see whether the benefits of infliximab, an immunosuppressive drug that reduces the effects of tumor necrosis factor (a protein that increases inflammation), outweighed its cost. Often combined with methotrexate to slow the progression of joint damage in moderate or severe RA, the drug’s costs were analyzed one year before and one year following initiation of treatment in 74 patients. Based on an analysis of inpatient and outpatient care,
orthopaedic surgeries, other drugs used, sick days, and rehabilitation in the year before and after treatment, it was found that one year of treatment significantly increased total medical costs, but also significantly improved the patients’ condition. The mean increase in medical costs during infliximab therapy was 12 euros ($15), but work disability costs decreased by 130 euros ($164). Infliximab, unlike other disease-modifying antirheumatic drugs, is claimed to reduce disease activity within weeks rather than several months.