Objective To investigate the differentiation of rat bone marrow mesenchymal stem cells (MSCs) to renal tubular epithelial-like cells under different conditions. Methods MSCs were obtained from rat marrow. MSCs were isolated by gradient density centrifugation and plastic adherence and then purified. Surface markers were identified with flow cytometry after amplification in vitro. The purified MSCs of the third passage were cultured respectively as follows: (1) control group: DMEM medium with fetal bovine serum(FBS). (2) all-trans retinoic acid (ATRA) group: DMEM medium with FBS, ATRA and ischemic reperfusion-injured kidney tissue homogenate. (3)combination group: DMEM medium with FBS, ATRA, ischemic reperfusion-injured kidney tissue homogenate, epidermal growth factor (EGF) and bone morphogenetic protein 7 (BMP-7). After 7 days, the MSCs were collected for alkaline phosphatase (AKP) staining, cytokeratin-18 and E-cadherin immunocytochemical analysis. Results The positive rates of the third passage MSCs in CD44, CD90 and CD29 were 97.8%±0.9%, 96.8%±1.4% and 97.6%±2.4%,respectively, but in CD11b/c and CD34 were only 13.2%±0.6% and 1.2%±0.5%. The MSCs in control group were spindle. The MSCs in ATRA group were round and elliptic. The MSCs in combination group became cobblestone-like cells after 7 days. AKP staining showed that tubular epithelial-like cells from MSCs in control group were negative, some above cells in ATRA group were positive and number of above cells increased in combination group. Compared with negative control group, the ratios of cytokeratin-18 positive cells in ATRA group and combination group were respectively increassed by 29.47%±1.08% and 47.52%±2.13% (all P<0.05), the ratios of E-cadherin positive cells in ATRA group and combination group were respectively increased by 14.88%±2.46% and 36.15%±1.13% (all P<0.05). Conclusion MSCs may differentiate by renal tubular epithelial-like cells under the induction of ischemic reperfusion-injured kidney tissue homogenate and ATRA in vitro, which are further differentiated under the combined induction of EGF and BMP-7.

Objective To study the clinical value of electronic bronchoscope in diagnosis and treatment of recurrent dyspnea in neonates.Method From October 2014 to October 2017,the clinical data of recurrent dyspnea receiving electronic bronchoscopy examination and treatment in the neonatal intensive care unit of our hospital were retrospectively selected.Their clinical characteristics and treatment effects were summarized and analyzed.Result A total of 171 infants of neonatal recurrent respiratory infections were examined using electronic bronchoscope.The top four causes included endo－tracheo－bronchitis in 78 cases (45.6%), laryngomalacia, and tracheobronchomalacia in 22 cases (12.9%), airway stenosis in 14 cases (8.2%) and esophagotracheal fistula in 12 cases ( 7.0%).The complications of intraoperative and postoperative included decline of percutaneous oxygen saturation and /or heart rate (20.5%, 35/171), mucosal bleeding (12.3%, 21/171 ), and fever after bronchoalveolar lavage.Electronic bronchoscopy examination confirmed all the 171 neonates′diagnosis and some of them recovered after corresponding treatment.78 cases of infants with endo－tracheobronchitis were all cured.22 cases of laryngomalacia and tracheobronchomalacia and nine patients with airway stenosis improved and were discharged after treatment . One patient with subglottic stenosis received bronchoscopic holmium laser ablation therapy and the airway significantly expanded.No re－stenosis was found during follow－up.Conclusion Electronic bronchoscopy is an important method to determine the cause of recurrent dyspnea in newborns , and it′safe,reliable and can play a therapeutic role in some neonates.