Objective To compare the pressor responses to ephedrine during general anesthesia with different drugs.Methods Sixty ASA physical status Ⅰ or Ⅱ patients,scheduled for elective gastrointestinal tumor resection under general anesthesia,aged 20-64 yr,weighing 45-90 kg,were included in this study.The patients were randomized to receive dexmedetomidine + remifentanil + sevoflurane (group Ⅰ,n =20),propofol + remifentanil + sevoflurane (group Ⅱ,n =20),or dexmedetomidine + propofol + remifentanil + sevoflurane (group Ⅲ,n =20) to maintain the depth of anesthesia.Ephedrine 0.1 mg/kg was injected intravenously when the systolic blood pressure (SBP) was decreased to about 90 mm Hg during anesthesia.Blood pressure was monitored and recorded at 1-min intervals for 10 min after the injection.The onset time (TSBP,TDBP,TMAP) for ephedrine to raise the SBP,diastolic blood pressure (DBP) and mean arterial pressure (MAP) and the maximal amplitude (△SBP,△DBP,△MAP) were also recorded.Results Compared with Ⅱ group,TSBP,TDBP and TMAP were significantly shortened,and △SBP,△DBP and △MAP were increased in Ⅰ and Ⅲ groups (P ＜ 0.05).Conclusion Compared with propofol + remifentanil + sevoflurane combined anesthesia,dexmedetomidine + remifentanil + sevoflurane combined anesthesia and dexmedetomidine + propofol + remifentanil + sevoflurane combined anesthesia augment the pressor responses to ephedrine in patients.

Objective To solve the problem that the rat retina paraffin sections are easily exfoliated from the slides and each layer are easily separation and fracture,we need to find a way to improve the retina paraffin section method and evaluate the tissue fixation. Methods We used 4 fixation liquids including 10%paraformaldehyde,4%paraformaldehyde, 4% paraformaldehyde and 95% alcohol and glacial acetic acid mixed liquid (FAA fixatiue solution ) combined with paraformaldehyde to fix the retinal tissue, and observed the fixation efficacy under microscope after HE staining. Results The effects of 10%paraformaldehyde and 4%paraformaldehyde fixed samples showed moderate separation and fracture of retina,but the HE staining retinal slices pre-treated by the FAA fixafive solution had bright and uniform color,although occasionally some parts of the retina were exfoliated from the slide, but it was not easy to take off,and had complete structure without separation and rupture. Conclusion The retina paraffin section fixed by FAA ixafive solution with 4% paraformaldehyde is superior to pure paraformaldehyde, and the paraformaldehyde concentration has no obviously influence on HE staining results.