Effect of occlusal splint on interleukin 6, malondialdehyde and 8-hydroxydeoxyguanosine levels in the synovial fluid of patients with temporomandibular disorders.

The actual role of splint therapy in preventing excessive loading of the temporomandibular joint (TMJ) is still debated. Lower intra-articular pressure levels have been measured in patients wearing occlusal splints, which may also reduce oxidative stress in the articular spaces. The aim of this study was to determine whether splint therapy reduces oxidative stress and inflammation in TMJ internal derangement patients by measuring interleukin 6 (IL-6), malondialdehyde (MDA), and 8-hydroxydeoxyguanosine (8-OHdG) levels in the synovial fluid (SF). Twenty-four patients with a temporomandibular disorder (TMD) were included in the study. TMJ SF samples were obtained prior to arthrocentesis. Twelve patients used a 2-mm hard acrylic, maxillary stabilization-type splint for 3 months after arthrocentesis. Twelve patients had no treatment after the SF aspiration. Second SF samples were obtained from all patients at 3 months post arthrocentesis. IL-6, MDA, and 8-OHdG levels in the samples were evaluated. All patients showed a significant symptomatic improvement after treatment (P < 0.005). No statistical correlation was found between the two groups concerning pre-treatment and 3-month SF levels of MDA, 8-OHdG, and IL-6. Although splint therapy was found to be successful in eliminating clinical symptoms of TMD, the results showed no beneficial effect on inflammation and oxidative stress markers in the synovial fluid.

Examination of caspase-dependent apoptotic and necrotic changes in rat kidney exposed to different doses of permethrin.

We investigated dose-related pathological alterations and apoptosis in rat kidney tissue exposed to permethrin. Histopathological findings, apoptotic cell death and urinary 3-phenoxybenzoic acid concentrations (3-PBA) were evaluated. Different doses of permethrin were administered to animals by oro-gastric gavage. A dose-dependent increase of urine 3-PBA concentration was observed in all the permethrin-treated groups. SDS-PAGE separated 30-45 kD and 100-220 kD protein bands in all experimental groups. Histopathologically, degenerative changes were observed in the epithelial lining of the S1, S2, and S3 segments of the renal proximal tubules. Apoptotic cells were seen in the inner stripe of the outer medulla in Group I, and both the cortex and medulla in Groups II and III. Immunohistochemical staining of caspase 3 and caspase 9 also was observed in the same areas. Our results suggest that damage to regions of the proximal tubules is dose-related, and caspase-9-dependent, mitochondria-related apoptotic cell death could play an important role in permethrin-induced nephrotoxicity. We also observed morphologically necrotic cells. We concluded that both necrosis and apoptosis are produced by permethrin.