<qa>  What is the name of the study that was conducted in North America and Europe?This is a phase III, multicenter, randomized patients are assigned different treatments based on chance, double-blind neither the patient nor the physician knows whether drug or placebo is being taken, or at what dosage, placebo-controlled study designed to determine the safety and effectiveness of Infliximab in the treatment of patients with psoriatic arthritis. This is an experimental medical research study. A total of 200 people in North America and Europe participated in this study during the 17 month study period. Patients will receive infusions of either placebo or 5 or 10 mgkg infliximab Remicade at weeks 0,2, 6, 14, 16, 18, 22, 30, 38, and 46. Safety evaluations will be performed at specified intervals throughout the study and will consist of laboratory tests, vital signs such as blood pressure, physical examinations and the occurrence and severity of adverse events as well as other study specific procedures. Patients will receive either placebo or 5 mgkg induction infusions weeks 0, 2 and 6 followed by maintenance infusions every 8 weeks until week 46. In the placebo group, patients may early escape at week 16 and crossover at week 24 to infliximab;. In the 5mgkg group, dose escalation if needed at week 38. 