Cytotoxicity of polycarbonate orthodontic brackets

Aim: To assess the cytotoxicity of polycarbonate orthodontic brackets. Methods: Polycarbonate brackets from two different manufacturers, namely, Composite bracket (Morelli™) and Silkon Plus bracket (American Orthodontics™), were assessed. In addition to these two experimental groups, other three control groups were included: Positive Control Group (C+) consisting of amalgam cylinders, Negative Control Group (C-) consisting of glass rods, and Cell Control Group (CC) consisting of cells not exposed to any material. All brackets were previously sterilized under ultra-violet light (UV) and, then, immersed in Eagle’s minimum essential media (MEM) for 24 hours, after which the supernatants were removed and placed into contact with L929 fibroblast cells. Cytotoxicity was evaluated at 24, 48, 72 and 168 hours. After contact with MEM, the cells were further incubated at 37oC for 24 hours and 100 mL of 0.01% neutral red dye were added. The cells were incubated again at 37ºC for three hours to incorporate the dye. After this period, the cells were fixed and viable cell counting was performed by spectrophotometry at 492 nm wavelength. Results: No statistically significant difference was found between the experimental groups (1 and 2) and the negative and cell control groups (p > 0.05). The Positive Control Group exhibited high cytotoxicity throughout experimental period are differed significantly from the other groups (p < 0.05). Conclusions: Polycarbonate orthodontic brackets were found not to be cytotoxic within the evaluated experimental period.

Toxic effects of five insecticides and their mixture on male albino rats

Five insecticides namely; abamectin, carbosulfan, fenpropathrin, methomyl and profenofos were given by gavages to male albino rats. These insecticides were administered daily for 28 days with doses equaled 1/20 LD 50 either singly or in a mixture of all the insecticides together. The study revealed significant decreases in body and kidneys weights, while increases in liver weights in all the treatments. Most of the treatments induced significant elevations in serum alanine aminotransferase [ALT] and aspartate aminotransferase [AST], while caused decreases in acetylcholinesterase [AChE] activities. Fenpropathrin and the mixture induced significant increase in total protein content of the serum, while the other treatments induced significant decreases. Creatinine concentrations recorded significant elevations in fenpropathrin and methomyl treatments, while significant decrease in case of Profenofos. Degenerative changes and granularity of hepatocytes with Kupffer cells activation were observed in the treatments with the mixture or and methomyl. Shrinking in Bowman's capsule and degenerative changes of epithelium lining renal tubules were observed in rats treated with the mixture. Moreover, necrotic changes associated with desquamation of epithelium lining tubules were shown in rats treated with the mixture, fenpropathrin and methomyl. From the biochemical data, the joint action was estimated for the mixture composed of the five insecticides. The mixture interacts antagonistically with most of the measured biochemical parameters

Neurotoxicologia clinica: los plaguicidas / Clinical neurotoxicology: pesticides

Los plaguicidas son compuestos quimicos de gran utilidad principalmente en la agriculatura. Su uso incorrecto e indiscriminado ha llevado a cuadros clinicos de neurotoxicidad importantes, en especial de Encefalopatia y Neuropatia Periferica. Se actualizan las diversas manifestaciones clinicas neurologicas en las intoxicaciones por Organofosforados, Organoclorados, Carbonatos, herbicidas como el Paraquat y los Repelentes de insectos