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.

Purpose To explore the influence of different spin-locking frequencies on T1ρ values based on a 3.0T MR system.Materials and Methods Thirty-eight healthy adult volunteers underwent cardiac magnetic resonance imaging at the First Affiliated Hospital of Anhui Medical University from July to September 2023.T1ρ mapping and short-axis cine imaging with steady-state free precession sequences were performed with 3.0T MR system.T1ρ mapping sequence in three short-axis slices with three spin-lock frequencies at the amplitude of 5 Hz,300 Hz,400 Hz,and 500 Hz was scanned,respectively.T1ρ relaxation times and myocardial fibrosis index were quantified for each slice and each myocardial segment,the difference in T1ρ of different spin-locking frequencies and myocardial fibrosis index was analyzed using one-way repeated-measures analysis of variance method.Results T1ρ of 5 Hz,300 Hz,400 Hz,and 500 Hz were(33.9±2.8)ms,(43.4±2.1)ms,(45.4±2.6)ms and(46.5±2.4)ms,respectively;and T1ρ values showed a significant progressive increase from the low spin-lock frequency to the high spin-lock frequency of the heart(300 Hz vs.400 Hz:P<0.001;300 Hz vs.500 Hz:P<0.001;400 Hz vs.500 Hz:P=0.043).In addition,the measured myocardial fibrosis index at 300 Hz,400 Hz and 500 Hz were(9.4±2.2)ms,(11.3±2.9)ms and(12.6±2.7)ms,respectively.Statistical analysis underscored significant variations among these measurements(300 Hz vs.400 Hz:P<0.001;300 Hz vs.500 Hz:P<0.001;400 Hz vs.500 Hz:P=0.033).Conclusion In this prospective study,myocardial T1ρ values for the specific cardiac magnetic resonance setting are provided,and we found that spin-lock frequency can affect the T1ρ values.

Objective:To investigate the application of cardiac magnetic resonance (CMR) quantitative techniques in evaluating myocardial involvement differences between new onset and longstanding systemic lupus erythematosus (SLE) patients.Methods:From August 2020 to April 2023, 14 new onset and 15 longstanding SLE patients treated at the First Affiliated Hospital of Anhui Medical University were prospectively included as the study group. Additionally, 18 age-, gender-, body surface area-, and body mass index-matched healthy volunteers were included as the control group. Clinical baseline data, electrocardiograms, and CMR results including left ventricular ejection fraction (LVEF), left ventricular end-systolic volume index (LVESVI), left ventricular end-diastolic volume index (LVEDVI), cardiac index (CI), left ventricular stroke volume index (LVSVI), left ventricular mass index (LVMI), myocardial strain, native T 1 values, and T 2 values were collected. One-way analysis of variance (ANOVA) or Kruskal-Wallis H test was used to compare the quantitative parameters among the three groups. Bonferroni correction was applied for pairwise group comparisons. Results:The native T 1 values [1 114.50 (1 089.33, 1 150.39) ms, 1 085.32 (1 051.31, 1 129.75) ms] and T 2 values [(55.9±3.4) ms, (53.3±1.5) ms] of new onset and longstanding SLE patients were higher than those of the healthy control group [native T 1 values 1052.62 (1024.75, 1077.59) ms, H=17.72, P<0.001; T 2 values (51.2±1.3) ms, F=18.70, P<0.001]. The T 2 values of the new onset SLE group was higher than that of the longstanding SLE group ( P<0.05). The LVEDVI[86.87 (80.80, 93.55) ml/m 2], LVSVI [54.63 (50.42, 59.03) ml/m 2], and LVMI [48.39 (41.65, 53.26) g/m 2] of the new onset SLE group were higher than those of the control group [LVEDVI: 71.11 (65.80, 81.28) ml/m 2, Z=3.02, P=0.003; LVSVI: 42.17 (40.36, 51.33) ml/m 2, Z=2.76, P=0.006; LVMI: 38.48 (35.22, 43.83) g/m 2, Z=3.10, P=0.002]. The LVEDVI and LVSVI of the new onset SLE group were also higher than those of the longstanding SLE group [LVEDVI: 73.30 (69.87, 84.71) ml/m 2, Z=1.97, P=0.048; LVSVI: 45.53 (42.28, 50.98) ml/m 2, Z=2.34, P=0.020]. Conclusion:Myocardial involvement is more severe in new onset SLE patients, whereas acute myocardial injury is alleviated in longstanding SLE patients. Therefore, early detection of cardiac involvement in SLE patients is crucial for improving prognosis.