Objective To investigate the effects of 3 different ventilation methods,including conventional mechanical ventilation(CMV),high-frequency oscillatory ventilation(HFOV) and partial liquid ventilation(PLV),on the morphology of type Ⅱ alveolar epithelium cell (ACE Ⅱ) of newborn piglet with acute lung injury (ALI).Methods Twenty-four less than 3-day-old newborn piglets were enrolled.After ALI was established with saline lavage (38 ℃,0.035 L/kg),newborn piglets were randomly assigned to 4 study groups:control group(n =6,no ventilation),CMV group(n =6),HFOV group(n =6),and PLV group(n =6,38 ℃,0.018 L/kg).Piglets in the 4 groups were sacrificed after being ventilated for 24 hours,and the number,area,density of fluorescence of ACE Ⅱ were detected.Results Through 24 hours mechanical ventilation,the numbers of ACE Ⅱ in CMV group,HFOV group and PLV group remained were 30 ± 5,52 ± 5,81 ± 7,respectively,while areas of fluorescence were 340.40 ± 47.50,329.69 ± 124.50,295.55 ± 109.30,respectively,and there were significant differences among the 3 groups,and the population mean of density of fluorescence had significant difference among the 3 groups.The number of ACE Ⅱ remains was lowest in CMV group compared with HFOV group(P =0.026) and PLV group (P =0.000),and the density of fluorescence of ACE Ⅱ was lowest in CMV group compared with HFOV group (P =0.001) and PLV group (P =0.002).Conclusions Different mechanical ventilations have various effects for ACE Ⅱ,and CMV is the most harmful mechanical ventilation on ACE Ⅱ,while PLV is the least harmful.

Objective To investigate the efficient method which can culture and induce embryonic stem cells to neurocyte in vitro. Methods Isolate the blastula of 3.5 d from BALB/c species mouse. Culture the cells from inner cell mass (ICM) which were isolated by mechanical method on the mouse embryonic fibroblaste cell (MEF) feeder layer or 0.1% gelatin coated dishes. The stem cells were identified by characterized morphology, alkaline phosphatase stain, differential potency in vivo and immunochemistry stain. The isolated cells were differentiated by serial induction method that mimicking the intrinsic developmental process of the neural system. Results The isolated cells were positive for alkaline phosphatatse and SSEA-1 (stage specific embryonic antigen 1). Moreover they were identified pluripotent by differentiation in vivo. Therefore the isolated cells presented the characters of ESCs. Then the isolated cells were able to differentiate into neurocytes in vitro. Conclusion Mouse embryonic stem cells isolation, culture and differentiation system has been established.