SPECIFIC AIMS:||To reverse hyperglycemia and insulin dependency in patients with Type 1 Diabetes Mellitus by islet cell transplantation;|To eliminate the incidence of hypoglycemia coma and unawareness in patients with Type 1 Diabetes Mellitus by islet cell transplantation;|To assess long-term safety and function of successful islet cell transplants in patients with Type 1 Diabetes Mellitus;|To determine whether the natural history of the microvascular, macrovascular and neuropathic complications of Diabetes Mellitus are altered following successful transplantation of islet cells; and|To assess the effect of infliximab in preventing early islet destruction, and thereby eliminating the need for a second donor's islet cells.|To assess the effect of etanercept in preventing early islet destruction.|To assess the effect of exenatide to improve islet graft function and survival in subjects that have returned to using exogenous insulin.|To assess the ability of exenatide to improve islet survival at time of transplantation.