Evidence for a differential translocation of actinides across human lung epithelial cell monolayer in vitro according to their physicochemical properties and the presence of a chelating agent.

The epithelial cell plays a key role in the transfer of radionuclides from lungs to blood following pulmonary exposure. The present study was designed to evaluate the transfer across human lung epithelial cells of various actinides (plutonium, americium and uranium), the influence of the physicochemical properties of plutonium compounds and of the chelating agent diethylene triamine pentaacetic acid (DTPA). To address this question, Calu-3 cells grown in a bicameral culture system were used. The integrity of the epithelial barrier was evaluated by measuring transepithelial electrical resistance (TEER) and the passage of a fluorescent marker, lucifer yellow. Activity measurement in basal compartment following periodic collection of culture medium was made from 2 h to seven days. To facilitate data handling and analysis, the statistical tool STATBIODIS was used. The results indicate differences in transfer for the different elements, and according to Pu physicochemical properties. Though to various extents, the chelating agent DTPA always increased the transfer of Pu and Am across the epithelial cells, without altering the integrity of the epithelial barrier. This in vitro cell culture model, by mimicking translocation of actinides from lungs to blood, can represent a valuable tool to further understand the underlying mechanisms and properties controlling this process.

Comparison of hemodynamic responses and QTc intervals to tracheal intubation with the McGRATH MAC videolaryngoscope and the Macintosh direct laryngoscope in elderly patients.

Our hypothesis was that intubations with the McGRATH MAC videolaryngoscope in elderly patients would produce less hemodynamic responses and ECG changes than the Macintosh direct laryngoscope. The patients were divided into two groups: patients who were intubated using the McGRATH MAC (Group V, n = 45) and patients who were intubated using the Macintosh direct laryngoscope (Group L, n = 45). Systolic blood pressure (SBP), diastolic blood pressure (DBP), mean arterial blood pressure (MAP), heart rate (HR) were recorded before induction with anesthesia (baseline), immediately after induction and at 1 min, 3 min, and 5 min after intubation, with simultaneous ECG. When Group L was compared to Group V, there was an increase in the first, third and fitth minutes after intubation in terms of HR. SBP, MAP increased only at 1 min after intubation and DBP increased in the first and third minutes after intubation in Group L. In Group L, there was a significant difference in the HR values immediately after induction and the first minute after intubation compared with the baseline values. There was a difference in the SBP values immediately after induction and at 3 min and 5 min after intubation compared with the baseline values. There was a difference in DBP and MAP values immediately after induction and at 5 min after intubation. When the McGRATH MAC videolaryngoscope was compared with the Macintosh direct laryngoscope in elderly patients, the McGRATH MAC videolaryngoscope decreased the hemodynamic fluctuations due to tracheal intubation.