Interaction between remimazolam and propofol for sedation during hysteroscopy / 中华麻醉学杂志

Objective:To evaluate the interaction between remimazolam and propofol for sedation during hysteroscopy.Methods:American Society of Anesthesiologists Physical Status classification Ⅰ or Ⅱ patients, aged 20-45 yr, with body mass index of 18-28 kg/m 2, scheduled for elective hysteroscopy, were included. The test was conducted in two steps. Up-and-down sequential allocation was used to determine the median effective dose (ED 50) of remimazolam (group A) and propofol (group B). The ED 50 obtained in A and B groups were then used as the standard to determine the combination regimen in group C (0.25×ED 50 of remimazolam+ 0.75×ED 50 of propofol as the initial dose), in group D (0.5×ED 50 of remimazolam+ 0.5×ED 50 of propofol as the initial dose), and in group E (0.75×ED 50 of remimazolam+ 0.25×ED 50 of propofol as the initial dose). Up-and-down sequential allocation was used to determine the ED 50 of propofol when propofol and remimazolam were combined in C, D and E groups. The interaction between the sedative effects of two drugs was analyzed using the isobolographic analysis method, and the interaction coefficient and synergistic dose ratio of two drugs were calculated. Results:The ED 50 of remimazolam was 0.180 mg/kg in group A, and the ED 50 of propofol was 1.167 mg/kg in group B. The results of isobolographic analysis showed that remimazolam and propofol had a synergistic effect. When remimazolam 0.045, 0.090 and 0.135 mg/kg were combined with propofol 0.546, 0.288 and 0.160 mg/kg, the interaction coefficients were 1.393, 1.339 and 1.127 respectively. The synergistic dosage ratio of remimazolam and propofol was 1.0∶(3.2 to 12.0). Conclusions:Remimazolam and propofol have a synergistic effect on sedation when used for hysteroscopy, and the dose ratio is 1.0∶(3.2-12.0).

Side population cells and progress in cancer stem cell research / 中南大学学报(医学版)

In recent years, cancer stem cells have become a hotspot for global researchers. Cancer stem cell theory deems that cells with self-renewal and differentiation potential play a key role in tumor resistance and relapse. These cells are named cancer stem cells. At present, the sorting methods include the side population cell sorting technique, screening techniques based on cell surface special markers, tumor sphere cultures, label retaining cell, ALDEFLUOR assays and so on. Side population cells are a small part of cells with the capacity of efflux DNA fluorescent dye Hoechst 33342 and present a low staining intensity in flow cytometry plot. Side population cells are rich in cancer stem cells, and its sorting method has been considered simple and effective in cancer stem cell research.