PURPOSE: The purpose of this study was to investigate the activation of the respiratory centers during insufflation of the larynx with CO2 at different flow rates and concentrations. MATERIALS AND METHODS: The experiments were carried out in spontaneous air breathing rabbits, anesthetized with thiopental sodium (25mg kg(-1) i.v.). The larynx was separated from the oropharyngeal cavity and the trachea. The tidal volume (VT) and respiratory frequency (f min(-1)) were recorded from the lower tracheal cannula. The respiratory minute volume (VE) was calculated, the action potentials from the right phrenic nerve were recorded and the inspiratory (TI) and expiratory (TE) periods and the mean inspiratory flow rate (VT/TI) were calculated. The larynx was insufflated at flow rates of 500mL min(-1) and 750mL min(-1), with 7 and 12% CO2-Air by means of a respiratory pump. RESULTS: Insufflation of the larynx, with both gas mixtures, decreased the f and VT significantly. The TI and TE were found to increase significantly due to the decreasing in f. There was a significant decrease in VT/TI ratio. Following bilateral midcervical vagotomy, on the passing of both gas mixtures, significant decreases were observed in the VT, and the responses of f, TI and TE were abolished. After cutting the superior laryngeal nerve, the responses of the VT to both gas mixtures were abolished. CONCLUSION: In conclusion, the results of this study purpose that the stimulation of the laryngeal mechanoreceptors by the effect of hyper- capnia decreases the activation of the respiratory center
Air ; Animals ; Carbon Dioxide/chemistry/*pharmacology ; Female ; Laryngeal Nerves/drug effects/physiology ; Male ; Mechanoreceptors/drug effects/physiology ; Rabbits ; Reflex/*drug effects/physiology ; *Respiratory Mechanics/drug effects ; Tidal Volume

Background: In this retrospective cohort of patients with primary, post-polycythemia vera, or post-essential thrombocythemia myelofibrosis, 57 patients with MF who received ruxolitinib for MF-related symptoms or symptomatic splenomegaly were evaluated. Methods: The median age of the patients in this cohort was approximately 58 years. Of these, there were 33 patients (57.9%) in INT-1, 23 patients (40.4%) in INT-2, and 1 patient (1.8%) at high risk. Overall, spleen size reduction of at least 35% (spleen response) was achieved in 56.6% and 63.3% of all cohort and INT-1 risk at any time, respectively. Results: Symptom response and clinical improvement were observed in 21.7% and 60.7% of patients, respectively. Anemia and thrombocytopenia were prevalent, but manageable.About 73.7% of patients continued treatment during a median follow-up of 22 months.Two-year OS probability was approximately 84.5% (95% CI, 63.1‒94.0%) and 62.3% (95% CI, 37.5‒79.6%) for the intermediate-1 and -2 risk groups, respectively. Conclusion Real-life experience in a community-based hospital confirms the efficacy and safety profile of ruxolitinib in intermediate-risk myelofibrosis. Treatment discontinuation rates were lower than those in clinical trials.