Patients who are males ages 16 to 35, who are not allergic to aspirin or other nonsteroidal anti-inflammatory drugs (known as NSAIDs), sulfites, or certain anesthetics, and who in good health may be eligible for this study. Females are not eligible, owing to the risks that thalidomide presents to unborn children. To minimize the risk of fetal malformations, male patients who participate must use a condom during sexual intercourse for 4 weeks following the study and must not donate blood for 4 weeks.