Objective To investigate whether microRNA-21-5p(miR-21)plays a protective role in hyperoxia-induced acute lung injury(HALI)by regulating ferroptosis through the STAT3/P53/SLC7A11 axis.Methods The interaction between STAT3 and P53 was analyzed by co-immunoprecipitation(Co-IP).Fifty 9-week-old male C57BL/6J mice were randomly divided into normoxia(Control)group,HALI group,miR-21 overexpression(miR-21)group,STAT3 inhibitor(HY-13818)group,and ferrostatin-1(Fer-1)group.After the mice from the miR-21 group received miR-21-5p AAV6 or empty vector via tracheal catheter instillation,the animals were then monitored for 3 weeks.The HY-13818 group was intraperitoneally injected with HY-13818(10 mg/kg)3 times weekly for 2 weeks.The Fer-1 group received 0.8 mg/kg ferrostatin-1 via tail vein injection once daily for 2 consecutive days during modeling.The HALI model was established by exposure to>90%oxygen.After 48 h of hyperoxia,blood samples were collected via orbital sampling for RT-PCR analysis of miR-21 expression.Lung tissues were harvested for wet/dry weight ratio and assessment of histopathological changes via HE staining for lung injury score.Activity of superoxide dismutase(SOD)and contents of malondialdehyde(MDA),Fe2?,glutathione(GSH),and reactive oxygen species(ROS)were measured using photocolorimetry,spectrophotometry and fluorometry.Western blotting was used to evaluate the protein expression of STAT3,P53,SLC7A11,and GPX4.Results The results of Co-IP showed that STAT3 could bind to P53.The HALI group exhibited obviously destroyed alveolar structure,disordered arrangement,thickened interval,with a large number of infiltrated neutrophils and collapsed alveoli,and had significantly increased pathological score of lung injury and ratio of lung Wwet/Ddry weight when compared with the Control group(P<0.05).In the miR-21 group,HY-13818 group and Fer-1 group,the severity of lung injury was significantly reduced,and the pathological score of lung injury and the ratio of Wwet/Ddry weight were decreased(P<0.05)when compared with the HALI group.Compared with the control group,the contents of MDA,Fe2+and ROS were increased(P<0.05),the activity of SOD and content of GSH were declined(P<0.05),the protein levels of STAT3 and P53 were increased(P<0.05),and those of SLC7A11 and GPX4 were decreased(P<0.05)in the HALI group.Compared with the HALI group,decreased MDA and ROS levels(P<0.05),enhanced SOD activity,Fe2+and GSH levels(P<0.05),down-regulation of STAT3 and P53(P<0.05)and up-regulation of SLC7A11 and GPX4(P<0.05)were observed in the miR-21 group and HY-13818 group.Conclusion MiR-21 alleviates HALI,which may be related to its inhibition of ferroptosis through the STAT3/P53/SLC7A11 axis.

Objective:To analyze and compare difference of ultrasonic blood flow of left internal mammary artery(LIMA) and right internal mammary artery(RIMA)as graft to left anterior descending artery(LAD) in patients undergoing off-pump coronary artery bypass grafting(OPCABG).Methods:From October 2017 to October 2019, a total of 363 patients who underwent OPCAB including 329 patients in LIMA-LAD group and 34 patients in RIMA-LAD group, were included in this study. Transthoracic ultrasound examination on IMA was performed before OPCABG. The blood flow , the value of PI(pulsation index) and diastolic flow(DF) of LIMA and RIMA to left anterior descending were measured and recorded by intraoperative TTFM. Patients underwent coronary artery CT examinations at 1 week after OPCABG to discover the patency of grafts.Results:The pre-operative diameter of RIMA was larger and the blood flow and pulsation index of RIMA was better than that of LIMA before OPCABG( P<0.001). But there was no significant difference in the flow, pulsation index and DF value of graft between the two groups after IMA were anastomosed to LAD( P>0.05). In situ skeletonized graft of RIMA did not show the advantage of increased blood flow. Compared with the preoperative parameters of flow of internal mammary artery, both the left and right grafts of IMA were significantly better in blood flow and pulsation index( P<0.001). Considering the remarkable difference in age between the two groups, Flow, PI and DF were compared again after propensity score matching, and there was still no statistical difference between the two groups( P>0.05). A total of 313 patients in LIMA-LAD group completed coronary CTA examination one week after surgery, among which 4 grafts had different degrees of problems. A total of 34 patients in RIMA-LAD group completed coronary CTA examination, one case indicated that the CTA imaging in distal segment was not clear, and the other results had no obvious abnormality. There was no significant difference in postoperative rate of coronary CTA completion( P=0.381) and rate of graft failure( P=0.405) between the two groups. Conclusion:Compared with the preoperative parameters of blood flow of internal mammary artery, both the left and right IMA grafts are significantly better in flow and pulsation index. The pre-operative diameter of RIMA is larger and the blood flow and pulsation index of RIMA is better than that of LIMA before OPCABG. But there is no significant difference in the flow, pulsation index and DF value of graft between the two groups after IMA are anastomosed to LAD. In situ skeletonized graft of RIMA do not show the advantage of increased blood flow.

Objective:To observate the changing trend of flow of in-situ bilateral internal mammary artery as grafts during perioperative period in patients undergoing coronary artery bypass grafting(CABG), and to compare the parameters of flow between LIMA and RIMA.Methods:A total of 57 patients , 50 males and 7 femails, mean aged(57.8±10.1) years, underwent bilateral IMA CABG in our hospital from August 2016 to January 2019. Transthoracic ultrasound of IMA examination was performed before CABG. The blood flow, the PI(pulsation index) and other parameters were measured and recorded by intraoperative TTFM.Results:There was no significant difference of the average diameter and PI between LIMA and RIMA, but the preoperative flow of RIMA is higher( P=0.026) in our study. There was no significant difference of the average flow and PI between LIMA and RIMA recorded by TTFM( P>0.05), but the higher diastolic flow(DF) in LIMA grafts( P=0.022) compared with RIMA grafts may be associated with the different target sites( P<0.05). Compared with the preoperative flow and PI of IMA, the intraoperative flow and PI of both LIMA and RIMA grafts were better( P<0.001). Conclusion:Compared with the preoperative flow of IMA, both flow of LIMA and RIMA are better. In spite of the targets exist difference , there are no significant difference of the average flow and PI between LIMA graft and RIMA graft recorded by TTFM.

Objective:To explore the effect of artificial intelligence teaching-picture system in training the bone marrow cell morphological reading ability of clinical medical students.Methods:A total of 110 five-year undergraduate students were divided into experimental group (artificial intelligence picture teaching method) and control group (traditional teaching method) in the bone marrow cell morphology reading ability training. On the basis of multimedia teaching, the experimental group was given the teaching by using the bone marrow cell morphology picture storage and transmission system for retrieval, learning and computer adaptive test. Then objective evaluation of image recognition ability and questionnaire were used to compare the teaching effect.Results:The image recognition ability was significantly better in the experimental group than in the control group [(89.6±5.7) vs. (81.4±4.9), P<0.01]. Furthermore, the experimental group showed more obvious advantages in cell morphology recognition [(74.7±4.0) vs. (68.7±4.9)] and diagnosis of hematological diseases [(14.9±3.0) vs. (12.9±2.4)] than the control group (both P<0.01). Questionnaire survey showed that the students expressed their affirmation and support for the artificial intelligence teaching-picture system in the bone marrow cell morphological reading ability training. Conclusion:The application of artificial intelligence teaching-picture system can greatly improve the teaching effect, mobilize students' learning enthusiasm and expand learning resources, which is worthy of further promotion and application.

OBJECTIVETo assess the role of oxidative metabolism and nitric oxide synthesis for elucidating their pathophysiological mechanisms in a Tibetan patient with essential hypertension.

METHODSThe serum levels of total superoxide dismutase (T-SOD), malondialdehyde (MDA), total antioxidant capacity (T-AOC), nitric oxide (NO) and nitric oxide synthase (NOS) were assayed in sixty native Tibetans (thirty hypertensive patients and thirty healthy volunteers as control).

RESULTSThe levels of T-SOD, T-AOC, NO and NOS were significantly lower in the patient group than in the control group (P < 0.01); MDA was significantly higher in the patient group than in the control group (P < 0.01). The level of MDA had a strong negative correlation with T-SOD, T-AOC, NO and NOS (r = -0.82, -0.76, -0.79, -0.73, respectively, P < 0.001 for all).

CONCLUSIONTibetan patients with essential hypertension (EH) may have underlying oxidative metabolism dysfunction and depressed NO synthesis, both responsible for the hypertensive process.

Adult ; Altitude ; Endothelium, Vascular ; physiology ; Female ; Humans ; Hypertension ; etiology ; Male ; Middle Aged ; Nitric Oxide ; biosynthesis ; Oxidation-Reduction ; Tibet

The muscle tonus of 7 (43 trials) swimmers were measured by the side of theswimming pool before and after training when they felt muscle stiffness and sore-ness. The muscle tonus and EMG of 10 (20 trails) swimmers and 5 (10 trails) runnrswere also measured and taken in the laboratory when they had a pain in the muscleafter training. The results showed that after training the muscle tonus was significantly higherthan before and the athletes had muscle stiffness and soreness. After stretching,not only the muscle tonus decreased, the athletes also felt better. The amplitude of the EMG appeared higher in the first stretching. then it be-came lower and lower with the stretching even showed electric silence. At the sametime, the muscle tonus decreased and the soreness was relieved. This study suggested that the early muscle soreness and stiffness are not cau-sed by local tissue edema, which is thought to be due to biochemical end-productsof metabolism, especially lactic acid. If muscle soreness and stiffness after vigo-rous exercises are the result of tissue edema, they can not be readily relieved byway of stretching technique since the water causing tissue edema cannot be remo-ved from the muscle tissue to the circulation in only about 30 seconds. Therefore, in our opinion, the early muscle soreness and stiffness are not cau-sed by biochemical but by physiological reasons, i. e. the physiological reflex spasmrelated with the functional state of the muscle spindle sensing system. Of course.this still needs to be confirmed by more extensive study in the future.