Objective Acute lung injury (ALI) and acute respiratory distress syndrome (ARDS) are common and life-threatening disease in children with mortality as high as 40%-70%. Alveolar type Ⅱ cells (ATII cells),characterized by the presence of lamellar bodies (LBs),synthesize and secret surfactant proteins (SPs),which contribute significantly to surfactant homeostasis and pulmonary immunity.The functions of ATⅡ cells including pulmonary surfactant production are autocratically dominated by the structural integrity of ATII cells.Our study is focused on the ultrastructural alterations of AT Ⅱ cells in rats with lipopolysaccharide(LPS)-induced ALI.Methods Rat ALI models were established by intraperitoneal injection of LPS (4 mg/kg).0.9 % NS with same amount was given in the normal control group.The rats were randomly chosen and sacrificed at 24, 48 and 72 hrs after LPS injection (8 rats at each time point).Lung samples (1 mm3 of the size) were obtained from the lower parts of left lungs and fixed with 2.5% glutaraldehyde for the transmission electron microscope examination.Results The microvilli around ATII cells disappeared and the number of LBs increased at 24 hrs after LPS administration.LBs rearranged like a ring around the nuclei.It was commonly seen that two nuclei were present in one AT Ⅱ cell.Vacuole-like deformity prominently occurred in cytoplasm at 48 hrs.Giant LBs presented at the same time.The shapes of nuclei were irregular and some of the borders were unclear at 48 and 72 hrs.The remnant of ruptured LBs scattered in cytoplasm at 72 hrs.The number of LBs reduced obviously.Karyolysis occurred in some of the nuclei.Conclusions The ALI-related alterations of ATII cells characterized by the changes of LBs,nuclei,and nucleoli were time-dependent. ATII cell injury was serious at 48 and 72 hrs.This may lead to the insufficiency of pulmonary surfactant synthesis and unstability of pulmonary homeostasis,which contributed to to the pathogenesis of acute lung injury.

Objective To explore the prognostic value of MCF in elderly patients with cardiac amy-loidosis using CMR.Methods A retrospective analysis was conducted on 54 elderly patients with cardiac amyloidosis diagnosed in our hospital.All patients underwent CMR imaging.They were di-vided into a survival group of 25 cases and a mortality group of 29 cases based on clinical out-comes.Correlations of MCF with CMR parameters and biochemical indicators were evaluated.Cox regression analysis was performed to identify independent predictors of patient survival.Survival analysis was used to assess the value of MCF in predicting patient prognosis.Results The surviv-al group had significantly higher MCF than the mortality group[(70.63±24.72)％vs(43.59± 13.36)％,P=0.001].As MCF increasing,LVEF level was in an increasing trend,while LVMI,LVGPWT,ECV,and troponin T and NT-proBNP levels showed a decreasing trend.Multivariate Cox regression analysis revealed that MCF was an independent predictor of patient survival(HR=0.922,95％CI:0.866-0.981,P=0.011).Kaplan-Meier survival curve showed that the patients with MCF＞57％had significantly higher survival rates than those with MCF ≤57％(P＜0.01).Conclusion MCF is an effective imaging indicator for evaluating the prognosis of elderly patients with cardiac amyloidosis,which can help identify high-risk patients and guide clinical treatment.