OBJECTIVE:To study the mechanism by which L-arginine regulates hypoxic pulmonary vascular structural remodeling.METHODS:Eighteen Wistar rats were randomly divided into control group,hypoxic group and hypoxic+L-arginine group.Pulmonary artery pressure was measured with right cardiac catheterization.Micro-structure and ultra-structure of pulmonary tissue were observed and collagen I expression was evaluated with immunohistochemistry.RESULTS:Mean pulmonary artery pressure(mPAP) was(2.7?0.3)kPa in hypoxic rats and(2.1?0.1)kPa in control rats(P

Objective:To investigate the pediatricians' needs in the contents of continuing medical education (CME), and the influencing factors of participating in CME, so as to provide references for improving their vocational ability.Methods:Questionnaire survey was carried out for the pediatricians from county-level medical institutions in the nine provinces of China. The questionnaire contents included: basic information, CME contents needs, and influencing factors of participating in CME. SPSS 22.0 was used for chi-square test.Results:A total of 465 questionnaires was recovered, among which 463 were qualified, with a pass rate of 99.6%. Research showed that ① In terms of competency training needs, pediatricians had higher training demand for ability of diagnosis and treatment of children's diseases, pediatrics basic skills and skills related to children's health care, etc. Pediatricians with junior or intermediate title had higher training demand for ability of self-learning and access to learning resources ( P < 0.01); and pediatricians with senior title had higher training demand for teaching ability ( P < 0.05). ② In terms of pediatrics specialty content training needs, pediatricians had higher demand for neonatology, infectious, respiratory, critical medicine, developmental behavior and digestion in order. ③ Regarding the influencing factors of CME, too few opportunities to participate in training, too busy to have time to participate, and defects in curriculum arrangement were the main factors affecting the CME participation of pediatricians. Conclusion:Pediatricians with different professional title had different training needs for CME contents. Lack of CME resources, contradiction between work and study, and curriculum arrangement deficiencies might be the main influencing factors affecting the CME participation of pediatricians working at county-level medical institutions.

Objective To assess the wall elasticity of the common carotid artery using echo-tracking in healthy children and children with hyperlipidemia.Methods The study included 68 normal healthy children and 25 children with hyperlipidemia.All the subjects were 3-18 years old.They were divided into three groups according to ages 3-6 years old group,7-13 years old group and 14-18 years old group.Echo-tracking was used to measure the pressure-strain elastic modulus (E?),stiffness parameter(?)and arterial compliance (AC) of the common carotid artery.Results The average values of E? were different among the three age groups in normal healthy children (all P

[ ABSTRACT] AIM:To explore the regulatory effect of intermedin ( IMD) on pulmonary collagen synthesis and ac-cumulation in rats with pulmonary hypertension induced by high pulmonary blood flow.METHODS: Healthy male SD rats (n=20) were randomly divided into control group (n=7), shunt group (n=7) and shunt with IMD group (n=6).The shunting of abdominal aorta and inferior vena cava was produced in rats of shunt group and shunt with IMD group.After 8 weeks, IMD was administered into the rats of shunt with IMD group subcutaneously by mini-osmotic pump for 2 weeks.Mean pulmonary artery pressure (mPAP), relative medial thickness (RMT) of pulmonary arteries, contents of hydroxyproline, collagen type I and III, bone morphogenetic protein-2 (BMP-2), and the mRNA expression of procollagen I and III in lung tissues were measured and compared.RESULTS:Compared with control group, mPAP and RMT of medium and small pul-monary arteries in the rats of shunt group were significantly increased.Meanwhile, the lung hydroxyproline, collagens I and III and BMP-2 contents, and the mRNA expression of lung procollagen I and III were all significantly increased compared with control group.However, IMD significantly decreased mPAP, alleviated the changes of pulmonary vascular micro-struc-ture, decreased the collagen accumulation and pulmonary tissue homogenate BMP-2 contents, and inhibited the mRNA ex-pression of procollagen I and III in the lung tissue of shunting rats.CONCLUSION:IMD plays a protective role in the de-velopment of pulmonary hypertension and pulmonary vascular structural remodeling induced by high blood flow by inhibiting pulmonary collagen synthesis and accumulation, possibly in association with the BMP-2 pathway.

Objective To investigate the effect of adrenomedullin(ADM) on hypoxic pulmonary vascular structural remodeling and proadrenomedullin N-terminal 20-peptide(PAMP) in rats with hypoxic pulmonary hypertension.Methods Twenty-four male Wistar rats were randomly divided into control group(n=8),hypoxia group(n=8) and hypoxia with ADM group(n=8).ADM was subcutaneously administered into rats of hypoxia with ADM group by mini-osmotic pump(300 ng/h).The concentration of plasma PAMP was measured by radioimmunoassay,and the expression of PAMP in pulmonary artery was detected by immunohistochemical assay.Results Mean pulmonary arterial pressure,the ratio of right ventricular mass to left ventricular plus septal mass,and relative medial thickness and relative medial area of pulmonary arteries significantly increased in hypoxic rats as compared with that of controls(P

OBJECTIVE:To study the preventive and therapeutic actions of L-arginine on pulmonary hypertension induced by high pulmonary blood flow volume.METHODS:Male SD rats were randomly divided into control group(n=6),shunt group (n=7) and shunt+L-arginine group(n=8).Abdominal aorta-inferior vena cava shunt was performed to make the blood flow from left to right,11 weeks later,mPAP was detected with right cardiac catheter;the structure of pulmonary vessels and expression of PCNA of smooth muscle cells were observed.RESULTS:The mPAP of shunt group was obviously higher than that of control(P

AIM: To examine the alteration of pathologic structure and gaseous molecules in rats with pulmonary hypertension induced by high pulmonary blood flow.METHODS: Aortocaval shunting was produced for 11 weeks in rats, and pulmonary hemodynamics was evaluated.Pulmonary vascular micro- and ultra- structure was also examined.Meanwhile,the concentration of plasma nitric oxide (NO) and carbon monoxide (CO) was measured by spectrophotometry.The expression of endothelial nitric oxide synthase (eNOS) and heme oxygenase-1 (HO-1) in pulmonary arteries was detected by immunohistochemistry.RESULTS: After 11- week aortocaval shunting,pulmonary artery mean pressure was significantly increased.Muscularization of small pulmonary vessels and relative medial thickness and area of pulmonary arteries were obviously increased in shunting rats compared with controls.Ultrastructure of intrapulmonary arteries changed obviously in shunting rats.Meanwhile,plasma NO concentration was increased and eNOS expression in pulmonary artery endothelial cells was significantly augmented in rats of shunting group.Plasma carbon monoxide level and HO-1 expression in puomonary artery smooth muscle cells,however,were not altered in shunting rats.CONCLUSIONS: Pulmonary vascular structural remodeling is the important pathologic basis of pulmonary hypertension induced by a left-to-right shunt,and NO other than CO might play an important regulating role in the development of high pulmonary blood flow-induced pulmonary hypertension.

AIM: To explore the regulatory effect of adrenomedullin (ADM) on pulmonary oxidative stress in the rats with pulmonary hypertension induced by high blood flow.METHODS: Healthy male SD rats (n=22) were randomly divided into control group, shunt group and shunt with ADM group.Abdominal aorta and inferior vena cava shunting was produced in the rats in shunt group and shunt with ADM group.After 8 weeks, ADM (1.5 μg·kg-1·h-1) was administered into the rats in shunt with ADM group subcutaneously by mini-osmotic pump for 2 weeks.Mean pulmonary artery pressure (mPAP) was evaluated by a right cardiac catheterization procedure.The ratio of right ventricular mass to left ventricular plus interventricular septal mass [RV/(LV+SP)] and relative medial thickness (RMT) in pulmonary muscularized arteries were calculated.The content of malonaldehyde (MDA), total antioxidative capacity (T-AOC), and activity of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) in lung tissues were detected by colorimetry.The expression of NADPH oxidase 4 (NOX4) in the lung tissue was analyzed by Western blot.RESULTS: Compared with control group, the mPAP, RV/(LV+SP) and RMT in pulmonary muscularized arteries in shunt group were all significantly increased.The content of MDA and the expression of NOX4 in the lung tissues were significantly increased.The T-AOC, and activity of SOD and GSH-Px in the lung tissues were significantly decreased.However, mPAP, RV/(LV+SP) and RMT in pulmonary muscularized arteries in shunt with ADM group were significantly decreased as compared with shunt group.Meanwhile, ADM decreased the content of MDA and the expression of NOX4 in the lung tissues, but increased the T-AOC, and activity of SOD and GSH-Px in the lung tissue of shunt rats.CONCLUSION: ADM inhibits oxidative stress response in the development of pulmonary hypertension and pulmonary vascular structural remodeling induced by high pulmonary blood flow in the rats by down-regulating the NOX4 expression and strengthening the anti-oxidation response.

Objective: To examine the alteration of pathologic structure and endogenous hydrogen sulfide pathway in rats with pulmonary hypertension induced by high pulmonary blood flow. Methods: Sixteen SD rats were randomly divided into shunting group and control group. An 11 week aortocaval shunting was produced in rats of shunting group, and pulmonary artery mean pressure (mPAP) was evaluated using right cardiac catheterization. The ratios of right ventricular mass to body weight (RV/BW) and right ventricular mass to left ventricular plus septal mass[RV/(LV+S)] were also detected. Pulmonary vascular micro and ultra structures were examined. Meanwhile the concentration of plasma hydrogen sulfide (H 2S) was measured by spectrophotography. The gene expression of cystathionine ? lyase (CSE)was detected by in situ hybridization, and the activity of CSE in lung tissues was measured by H 2S production according to chemical analysis. Results: After 11 weeks of aortocaval shunting, pulmonary artery mean pressure was significantly increased. Muscularization of small pulmonary vessels and relative medial thickness of pulmonary arteries were obviously increased in shunting rats compared with controls. Ultrastructure of intrapulmonary arteries changed obviously in shunting rats. Meanwhile, plasma H 2S concentration was decreased and the activity of CSE (according to H 2S production) in lung tissues decreased in shunting rats. CSEmRNA expression by pulmonary arteries was significantly suppressed. Conclusion: Pulmonary vascular structural remodeling is the important pathologic basis for pulmonary hypertension induced by high pulmonary blood flow. The down regula tion of endogenous H 2S pathway might play an im portant role in the development of high pulmonary blood flow induced pulmonary hypertension.

Objective:To explore the application effect and feedback of online pediatrics teaching for the clerkship and internship stage of medical students of clinical medicine eight-year program.Methods:In this study, 38 clerkship medical students and 12 internship medical students of clinical medicine eight-year program in pediatrics department of Peking University First Hospital from February to March, 2020 were selected as research objects. They had two weeks of online teaching, including online flipped classroom, case-based learning (CBL), and problem-based learning (PBL). The effect of online teaching, and the feedback from these students were all investigated through the questionnaire survey.Results:All students were satisfied with the overall arrangement of the online teaching and believed that the results exceed [42% (21/50)] or meet [58% (29/50)] their expectations. According to the feedback, network congestion [82% (41/50)] was the biggest problem in online teaching, followed by the inability of effective interaction [20% (10/50)]. Students all believed that the online teaching arrangement was most helpful for the cultivation of theoretical knowledge (Total scores 4.58±0.50), autonomous learning ability (Total scores 4.42±0.58) and clinical reasoning (Total scores 4.42±0.58), but had minimal impact on the skills operation (Total scores 2.68±0.87) and scientific research ability (Total 2.98±0.98). For the ability of communication between doctors and patients, the scores of clerkship students (3.79±0.99) were significantly higher than those of internship students (3.08±0.67), ( P<0.05). Clerkship students considered that online flipped classroom was the most helpful teaching mode, while internship students believed online CBL teaching was the most helpful one. Majority of the students (94%) think it's necessary to keep online teaching in the future. Conclusion:Online teaching of pediatrics is approved by the medical students of clinical medicine eight-year program in the stage of clerkship and internship, and plays an important role in the cultivation of the ability of medical students, but it can't completely replace offline clinical practice.