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 investigate the clinical effect of percutaneous curved vertebroplasty in the treatment of thoracolum-bar osteoporotic vertebral compression fractures (OVCFs). Methods: All of 85 patients with single thoracolumbar vertebral OVCFs who met the admission criteria from January 2017 to July 2018 were divided into three groups according to the random dig-its table method. They were treated with percutaneous curved vertebroplasty, routine unipedicular PVP and routine bipedicular PVP respectively. There were 25 patients in the percutaneous curved vertebroplasty group, 6 males and 19 females; aged 56-80 years, with an average age of 70.6±9.7 years. Fracture vertebral body distribution: T₁₀ 2 cases, T₁₁ 4 cases, T₁₂ 3 cases, L₁ 9 cases, L₂ 3 cases, L₃ 1 case, L₄ 1 case and L₅ 2 cases. There were 32 patients in the routine unipedicular PVP group, 6 males and 26 fe-males; aged 58-75 years, with an average age of 69.5±9.3 years. Fracture vertebral body distribution: T₁₀ 2 cases, T₁₁ 4 cases, T₁₂ 5 cases, L₁ 11 cases, L₂ 6 cases, L₃ 1 case, L₄ 1 case and L₅ 2 cases. There were 28 patients in the routine bipedicular PVP group, 5 males and 23 females; aged 59-81 years, with an average age of 69.8±8.8 years. Fracture vertebral body distribution: T₁₀ 2 cases, T₁₁ 4 cases, T₁₂ 4 cases, L₁ 10 cases, L₂ 4 cases, L₃ 1 case, L₄ 1 case and L₅ 2 cases. The operation time, injected cement volume, in-traoperative blood loss were recorded and analyzed. Preoperative, postoperative 1 week and 3 months visual analogue scale scores and oswestry disability index were adopted to value the clinical improvements. Preoperative, postoperative 1 week and 3 months relative vertebral height and kyphosis correction, and the cement leakage rate were measured and analyzed. Results: There was no significant difference in the data of gender, age, VAS scores, ODI and distribution of fracture vertebrae among the three groups (P>0.05), and the baseline data was comparable. The average VAS score in the percutaneous curved vertebroplasty group was 2.3±0.5 at 1 week after surgery, that of the routine unipedicular PVP group was 2.4±0.4 and that of the routine bipe-dicular PVP group was 2.4±0.4; the average ODI in the percutaneous curved vertebroplasty group was 19.8%±3.9%, that of the routine unipedicular PVP group was 20.0%±4.1% and that of the routine bipedicular PVP group was 19.9%±3.8%; they were lower than the preoperative data, which were statistically significant (P<0.001). The average relative vertebral height in the percutaneous curved vertebroplasty group was 48.99%±9.23% at 3 months after surgery, that of the routine unipedicular PVP group was 47.11%±10.12% and that of the routine bipedicular PVP group was 46.71%±11.16%; the average kyphosis cor-rection in the percutaneous curved vertebroplasty group was 6.21%±1.94%, that of the routine unipedicular PVP group was 5.22%±2.07% and that of the routine bipedicular PVP group was 5.97%±2.09%; there was 1 cement leakage case in the per-cutaneous curved vertebroplasty group; those of the routine unipedicular PVP group were 4 cases and those of the routine bipe-dicular PVP group were 6 cases; there was no significant difference among the three groups (P>0.05). Operation time 39.10±2.00 min vs 38.70±1.70 min, injected cement volume 3.60±0.11 ml vs 3.50±0.13 ml and blood loss 5.10±0.30 ml vs 5.00±0.40 ml of the percutaneous curved vertebroplasty group and the routine unipedicular PVP group were less than those of the routine bipedicular PVP group, which were statistically significant (P<0.05). Conclution Percutaneous curved vertebroplasty could achieve satisfactory clinical outcomes for OVCFs, with advantages of less operation time, less blood loss, limited X-ray expo-sure, less injected cement volume, and more balanced augmentation for stabilization of the affected vertebrae and total verte-bral column.