RESUMEN
BACKGROUND: Mechanical insufflation-exsufflation (MI-E) is necessary for noninvasive management of respiratory clearance in patients with neuromuscular disorders (NMDs). Its utility has been proven, and the technique is recommended in a number of international guidelines for the management of patients with NMDs. However, the clearance of thick secretions adhering to the tracheobronchial walls could be problematic when these patients suffer from respiratory tract infections. To improve the effectiveness of the noninvasive technique, a novel device combining MI-E with high frequency oscillation (HFO) has been developed. However, the efficacy of HFO therapy in NMDs has not been well studied. OBJECTIVE: The aim of this study was to elucidate the effect of MI-E combined with HFO for mucus removal in NMD patients. To evaluate its efficacy, changes in transcutaneous oxygen saturation (SpO2), which may predict intratracheal mucus removal, will be measured before and after use of MI-E. METHODS: This is a single-center, nonblinded, nonrandomized prospective study that will enroll 5 subjects hospitalized in Kobe University Hospital owing to respiratory tract infection. All subjects will receive MI-E therapy a few times daily and will receive HFO every other day, for 6 days. Before and after MI-E use, SpO2 will be obtained and the change in SpO2 (ΔSpO2) between MI-E with and without HFO will be calculated. For every subject, the average of ΔSpO2 with or without HFO will be obtained and the null hypothesis that there is a mean change of 0 in the SpO2 between MI-E with and without HFO will be tested using the paired t test. If the treatment with HFO is found to be statistically significantly superior to the treatment without HFO, the study will conclude that HFO addition is more efficacious than no HFO addition. RESULTS: A total of 2 subjects have already been recruited and enrolled in this study as of August 2018. CONCLUSIONS: This unique protocol will assess the efficacy of adding HFO to MI-E during the acute phase of respiratory tract infection in patients with NMDs. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): DERR1-10.2196/12102.
RESUMEN
To establish an ex vivo expansion method of haematopoietic progenitor cells (HPCs) and erythroid cells, three-dimensional (3D) cultures of mouse bone marrow cells were performed, employing a porous polyvinyl formal (PVF) resin as a scaffold. In these cultures, the effects of oxygen concentration and co-cultures with stromal cells on the expansion of HPCs and erythroid cells were investigated. When bone marrow cells were cultured under 3D conditions, HPCs and erythroid cells expanded without supplementation of exogenous cytokines, irrespective of the presence of stromal cells. On the contrary, slight expansion of HPCs or erythroid cells was observed in monolayer cultures as controls, indicating that the 3D cultures using the PVF scaffold were far better in expanding HPCs and erythroid cells than the monolayer cultures. Under hypoxic conditions, bone marrow stromal cells allowed for a 3D culture of erythroid cells and HPCs at higher cell densities compared to cultures without stromal cells, and the duration of the expansion of HPCs and erythroid cells after initiating the 3D co-cultures was prolonged. The number of these cells increased throughout the culture period up to 3 weeks under hypoxic conditions, although the number decreased after 2 weeks under normoxic conditions. In conclusion, the 3D co-culture method of haematopoietic cells with stromal cells under hypoxic conditions was confirmed to be effective in expanding HPCs and erythroid cells, and this method seemed to be useful for developing an ex vivo expansion method for haematopoietic cells.