Objective To explore the survival/proliferation,apoptotic and death effects of keratinocyte growth factor (KGF) in alveolar epithelial type Ⅱ cells (AT Ⅱ Cs) exposed to hyperoxia.Methods Primary culture of AT Ⅱ Cs from the Sprague-Dawley rat fetuses was studied under room air condition (210 mL/L O2) and hyperoxic condition (950 mL/L O2) for 0.5-12.0 h.Various concentrations of KGF (15 μg/L,25 μg/L,50 μg/L,75 μg/L,100 μg/L)were added into the cell cultures.Cells were randomly divided into room-air group,room-air-KGF group,hyperoxic-exposure group and hyperoxic-exposure-KGF group.The levels of intracellular reactive oxygen species (ROS),cleaved cysteinyl aspartate specific proteinase-3 (Caspase-3),cell death and proliferation of AT Ⅱ Cs were measured by flow cytometer,Western Blot,release of lactate dehydrogenase assays (LDH assays) and 3-(4,5-Dimethyhhiazol-2-yl)-2,5-diphenyhetrazolium bromide assays (MTT assays),respectively.Results Under room air condition,KGF could significantly increase AT Ⅱ Cs proliferation with 15-100 μg/L in a dose-dependent manner and significantly decrease LDH production at concentrations of 25-100 μg/L.Exposure to hyperoxia resulted in a significant increase in intracellular ROS production in AT Ⅱ Cs in a time-dependent manner compared with that of the room air group.Cell viability decreased and LDH release increased significantly in a time-dependent manner when AT Ⅱ Cs were exposed to 950 mL/L O2 for more than 4 h.After exposure to hyperoxia for 0.5 h and 1 h,KGF could significantly increase AT Ⅱ Cs proliferation in 15-75 μ g/L and significantly decrease LDH production at concentrations of 25-75 μg/L.After exposure to hyperoxia up to 4 h,higher viability was observed in 15 μg/L and 25 μg/L KGF group,and lower death rate presented in 25-100 μg/L KGF group.Further,prolnged hyperoxic exposure for 8 h,high viabilitv was shown only in 50 μg/L KGF group,and less death rate was observed only in 75 μg/L KGF group.In addition,no significant difference in viability and mortality was found between hyperoxic group and hyperoxic-KGF group after hyperoxic exposure for 12 h.Expression of cleaved Caspase-3 was significant higher after 4 h and 8 h hyperoxic exposure than that in room-air group ;at the same time,by adding 25 μg/L and 75.μg/L KGF led to decreased expression of Caspase-3 was detected,compared to hyperoxic group.Conclusions KGF may promote survival/proliferation,inhibited apoptosis and death of rat fetal AT Ⅱ Cs in room air condition or under temporary exposure to hyperoxia in vitro.However,prolonged exposure to hyperoxia may decrease the sensitivity of AEC Ⅱ Cs to KGF and limit its protective effects on lung injury.

Objective To evaluate the value in the diagnosis of focal nodular hyperplasia( FNH) by combining micro-flow imaging ( MFI) and color Doppler flow imaging ( CDFI) . Methods A total of 32 patients with 32 FNH lesions were enrolled in this study . Each patient underwent CDFI ,MFI ,and contrast-enhanced ultrasonography ( CEUS ) examinations . The differences in the grade and characteristic distribution of blood flow in FNH were compared between CDFI and MFI . The results were further compared with CEUS . Results There was a significant difference between MFI and CDFI in detecting the blood flow in FNH . Twenty-six cases (81 .3％ ) were detected with blood flow of grade Ⅱ and Ⅲ by MFI , however , 18 cases ( 56 .3％ ) were detected of grade Ⅱ and Ⅲ by CDFI ( P = 0 .000) . A total of 12 (37 .5％ ) lesions were correctly showed spoke-wheel arterial flow peculiar by CDFI ,whereas the number increased to 23(71 .9％ ) in combination with MFI( P = 0 .013) . Conclusions In combination with MFI , CDFI can reveal more blood flow and detect more sensitively in FNH ,which helps to diagnose FNH . To a certain degree ,it can be applied to reduce the use of CEUS .