Orthodontic tooth movement after inhibition of cyclooxygenase-2.

Introduction: The purpose of this study was to compare the effects of a conventional nonsteroidal anti-inflammatory drug, diclofenac (Voltaren [Novartis, Barcelona, Spain]), and a specific cyclooxygenase-2 (COX-2) inhibitor, rofecoxib (Vioxx [MSD, Madrid, Spain]), on the inhibition of dental movement induced with a coil-spring orthodontic apparatus in rats.

Methods: Tooth movement was measured on the lateral cranial teleradiographs of 42 male Wistar rats in 6 experimental groups: (1) 50-g coil spring and 2 rofecoxib injections of 1 mg per kilogram of body weight; (2) similar orthodontic procedure and 2 diclofenac injections of 10 mg per kilogram of body weight; (3) the same orthodontic treatment and 0.9% saline-solution injections; and (4), (5), and (6) 100-g coil appliance and the same pharmacological treatment as 1, 2, and 3, respectively.

Age-dependent changes in the nervous and endocrine control of the thymus.

The immune system, especially the thymus, undergoes age-related modifications leading to structural and functional changes in the lymphoid organs and immunocompetent cells. Nevertheless, the consequences of thymic involution in the peripheral pool of T-cells are still a matter of controversy. The control of the thymic function is very complex and involves intrathymic signals, the autonomic nervous system, and the endocrine system.

Age-related changes in the avian primary lymphoid organs (thymus and bursa of Fabricius).

The avian primary lymphoid organs, the thymus and the bursa of Fabricius, undergo age-dependent changes leading in some cases to the complete atrophy of the organ. Nevertheless, the timetable of the involutive process as well as the consequences in the structure and functionality of the organs vary largely in the time frame and structural changes among species. On the other hand, and in contrast with the large body of literature reporting the structural and functional changes in mammalian primary lymphoid organs, the age-dependent changes in avian thymus and bursa of Fabricius are scarce, fragmentary, and heterogeneous.