Syncope is one of the most common emergencies in the pediatric population.Autonomic -mediated reflex syncope,including postural tachycardia syndrome and vasovagal syncope,is the main cause.Although the clinical manifestations are similar,each subtype has its optimal treatment option.With the development of translational medicine in recent years,as well as the emergence of biomarkers,precision medicine has become possible,and will be the main direction in the future researches.

OBJECTIVE:To study the therapeutic effect of L-arginine on collagen metabolism of pulmonary artery in rats with high pulmonary blood flow METHODS:The rat model of pulmonary hypertension was established with an abdominal aorta and inferior vena cava shunting L-arginine was intragastrically given to the rats with shunt in L-arginine group(1g/(kg?d)) for 11 weeks After 11 weeks of experiment,the expressions of collagen Ⅰ and collagen Ⅲ in pulmonary artery were detected by immunohistochemical assay RESULTS:The expressions of collagen Ⅰ and collagen Ⅲ in shunt group elevated obviously compared with those in control group(P

Myocarditis is one of the most common acquired heart diseases in children,and one of the most common causes of a pediatric dilated cardiomyopathy phenotype.The myocarditis is a difficult issue in the diagnosis and the optimal means of therapy.A recent Pediatric Cardiomyopathy Registry (PCMR) analysis in the largest group of pediatric myocarditis patients ever studied confirmed that the most common outcome in pediatric myocarditis was cardiac recovery,but approximately 30％ of pediatric myocarditis patients would die or undergo heart transplantation.Animal studies and adult experience suggested that autoimmunity might contribute to cardiac dysfunction in myocarditis.Immunosuppressive and immunomodulating therapy for pediatric myocarditis remains controversial.Small case series have shown benefit of these therapies in pediatric myocarditis.A limited number of biomarkers associated both good (recovery) and poor (death or transplantation) outcomes could be identified.We should do our best to find these biomarkers in the future.

Syncope is a common clinical problem in children and adolescents. It is a major challenge for practicing physicians, and medical resource utilization and expenses associated with syncope management are enormous. A diagnostic protocol to syncope must be developed for children and adolescents for convenient and effective final diagnosis, and an analysis of cost-effectiveness is meaningful. Thus, according to the studies of syncope in children in China,the Chinese Pediatric Cardiology Society proposed the guidelines for diagnosis of syncope in children in China, and developed a simplified diagnostic protocol for children and adolescents with syncope. According to a multi-center prospective study,the diagnostic protocol in children and adolescents with syncope results in an improvement of diagnostic yield.

Hypertension in children and adolescents is defined as systolic blood pressure(SBP)and/ or dias-tolic blood pressure(DBP)≥95th percentile for age,gender and height,on at least 3 occasions. Primary hypertension is more common among children of older age or adolescents,while secondary hypertension accounts for more cases for younger children. Among causes of secondary hypertension,renovascular diseases,renal parenchymal diseases,cardio-vascular diseases,and endocrine diseases are common. An initial evaluation can be reached after history taking and physical examination,to decide whether it should be primary or secondary hypertension. Laboratory tests and procedures can further confirm the classification and etiology. There is an increase in prevalence of hypertension in children and adolescents,and an in - time diagnosis and evaluation of hypertension is important to help patients receive a better management of their conditions.

Arrhythmia-induced cardiomyopathy (AIC) is a myocardial disease condition in which left ventricular dysfunction and cardiomegaly are induced or mediated by atrial or ventricular arrhythmias.The pathophysiological mechanisms remain unclear.Early recognition of AIC and provision of prompt treatment with pharmacological or ablative techniques could result in symptom resolution and recovery of ventricular function.But,the long-term prognosis of these patients is not clear and needs further observation and research.

Sulfur dioxide (SO_2) is an ordinary air pollutant globally and harm to human health. L-cysteine is the major sulfur-containing amino acid and its normal metabolism can produce hydrogen sulfur (H_2S) and SO_2. It is realized that H_2S has various bioactivities and is the third gasotransmitter after nitric oxide (NO) and carbon monoxide (CO). Recently, attention has been paid to the physiologic effects of endogenous SO_2 and its derivatives (bisulfite and sulfite) in vivo, and recognized that SO_2 and its derivatives can lower blood pressure, change heart rates, participate in inflammatory reactions, and so on, suggesting that endogenous SO_2 may modulate the physiologic functions in vivo as a bioactive molecule.

Objective: To explore the effects of ligustrazine on the secretion of hydrogen sulfide in the ventricular tissues of rats under physiological condition.Methods:32 rats were divided into control group,high dose group of ligustrazine(150?g/ml),medium dose group of ligustrazine(15?g/ml) and low dose group of ligustrazine(1.5?g/ ml) at random.The left and right ventricular tissues were incubated in 37℃ thermostatic water bath for 4 hours with Krebs solution as supernatant.After incubation of the ventricular tissues,the sensitive electrode-based method was used to detect the content of H2S in the supernatant.Results: In the left ventricular tissues,there were on dif-ference of the H2S level betweenthe 1.5?g/ml ligustrazine group(0.17?0.03),15?g/ml ligustrazine group(0.17?0.03)and control group.However,compared with control group, the H2S level in hige dose group of ligustrazine decreased obviously(P0.05),but the H2S level in the 150?g/ml ligustrazine group(0.46?0.09)was significantly lower than that in the control group(0.64?0.13)(P

Aim To explore the effect of hydrogen sulfide (H2S) donor on the pathogenesis of atherosclerosis in apolipoprotein E knock out mice (Apo E-/-).Methods 6-week old C57BL/6J and Apo E-/-mice were divided into normal group, Apo E-/-group and Apo E-/-+ sodium hydrosulfide(NaHS)group,with 8 mice in each group. They were fed chow diet until 16-week old. The serum levels of total cholesterol, low density lipoprotein and high density lipoprotein were determined and the changes of atherosclerosis plaque size were observed. Sulfide electrode-based method was used to measure the serum level of H2S.Results The serum levels of total cholesterol[(12.59?3.11 vs 2.32?0.40) ?mol?L-1]and low density lipoprotein[(1.33?0.43 vs 0.13?0.03) ?mol?L-1] in Apo E-/-mice were significantly higher than those in normal group, while the serum levels of high density lipoprotein[(0.45?0.13 vs 1.49?0.21) ?mol?L-1]and H2S in Apo E-/-mice[(44.64?4.52 vs 57.69?7.03) ?mol?L-1]were significantly lower than those in normal group. Meanwhile, the atherosclerosis plaque[(139316.6?30362.93 vs 0) ?m2] was obvious in Apo E-/-mice. After NaHS was administrated, there were no obvious changes in the serum levels of total cholesterol, low density lipoprotein and high density lipoprotein in Apo E-/-mice, while the serum level of H2S[(52.21?7.24 vs 44.64?4.52) ?mol?L-1]increased significantly and the size of atherosclerosis plaque[(85927.84?1922.73 vs 139316.6?30362.93) ?m2]diminished significantly.Conclusions H2S postponed the proceeding of atherosclerosis and diminished the size of atherosclerosis plaque.

Objective To explore the effect of hydrogen sulfide(H2S) on intercellular adhesion molecule-1(ICAM-1) in the pathogenesis of atherosclerosis in apoE knockout(apoE-/-) mice.Methods Six week-old C57BL/6J and apoE-/-mice were divided into control C57BL/6J group,apoE-/-group,apoE-/-+ sodium hydrosulfide(NaHS,a donor of H2S) group and apoE-/-+ DL-propargylglycine(PPG,an inhibitor of H2S synthase).There were 8 mice in each group.They were fed chow diet for 10 weeks.Serum H2S was measured by sulfide electrode-based method,serum ICAM-1 was determined by ELISA.Aortic ICAM-1 mRNA was detected by RT-PCR.The changes of atherosclerosis plaque size were observed by oil red O staining.Results Serum H2Slevel significantly decreased in apoE-/-mice(P