Synergistic effects of cigarette smoke and saliva

Objectives: The aim of this study was to evaluate the cytotoxic effects of Cigarette Smoke on the human peripheral blood lymphocytes in the presence of stimulated or non-stimulated saliva in an in vitro model.Methods and Materials: Ten healthy volunteers in the age range of 21 to 29 were selected and samples of peripheral blood lymphocytes and saliva (whole and stimulated saliva) collected. Peripheral blood lymphocytes suspensions (PBS) were taken and exposed to 6 different media. Samples were collected from all media at both 20 and 80 minute time points. The survival rates of PBL were then determined at both 20 and 80 minute time points.Results: The cell survival rates following exposure to cigarette smoke (CS) in the presence of PBS supplemented with whole or stimulated saliva were significantly lower at 80 minutes when compared with the 20 minute rates (P<0.05).Conclusion: Tobacco effects were significantly increased in the presence of saliva especially stimulated saliva

A FUNCTIONAL ANALYSIS OF THE MEDIAL PTERYGOID MUSCLE DURING JAW CLOSING AND HORIZONTAL FORCE IN HUMANS

There is limited information regarding the normal function of the medial pterygoid (MP) muscle, a major jaw muscle. The aims of our study were to develop a methodology to record from the MP during standardized isometric jaw closing tasks, to determine the range of tasks over which activity can be recorded in the MP, and to determine whether there is evidence for functional heterogeneity within the MP muscle by comparing electromyographic (EMG) features in different regions of the MP. Fifteen healthy participants were included in the study. The EMG activity of the right MP was recorded with intramuscular electrodes during the performance of isometric jaw closing tasks onto a force transducer as well as isometric contralateral (i.e. to the left side), protrusive (straightforward) and ipsilateral (i.e. to the right side) jaw tasks using another force transducer in the same participants. The isometric tasks were ramp tasks (at a fast rate and at a slow rate) and step level tasks (at 2 force levels). A computed tomography (CT) scan was performed for all participants and the presence of MP activity, thresholds of single motor units, and root means square (RMS) activity were assessed in the tasks. The MP was active in all jaw closing tasks in all participants, but in the horizontal tasks, the MP was mostly active in the protrusive and contralateral tasks (85% of participants), while it was activated in 57% of the participants in the ipsilateral tasks. The mean force threshold value for the fast jaw closing ramp task was significantly (P<0.05) lower than for the slow jaw closing ramp task. However the differences were not significant for any of the horizontal tasks. The EMG activity of the MP in all jaw closing and horizontal tasks was positive except for the ipsilateral tasks when the MP was not active in the ipsilateral tasks at all. CT scan verifications of the electrodes locations suggest a more important role for the lateral part of the MP in the generation and/or control of the horizontal jaw force tasks than the medial part. Also, a crucial role for the medial part in the vertical jaw closing tasks is proposed. These findings support the functional heterogeneity of the MP due to its selective activation in various tasks. This study proposes an important role for the MP in the generation of closing and lateral forces and also supports a role for the MP as being functionally heterogeneous