Metal nanoparticles capped with plant polyphenol for oxygen reduction electrocatalysis.

The development of a convenient and universal strategy for the synthesis of inorganic-organic hybrid nanomaterials with phenolic coating on the surface is of special significance for the preparation of electrocatalysts. In this work, we report an environmentally friendly, practical, and convenient method for one-step reduction and generation of organically capped nanocatalysts using natural polyphenol tannic acid (TA) as reducing agents and coating agents. TA coated metal (Pd, Ag and Au) nanoparticles are prepared by this strategy, among which TA coated Pd nanoparticles (PdTA NPs) show excellent oxygen reduction reaction activity and stability under alkaline conditions. Interestingly, the TA in the outer layer makes PdTA NPs methanol resistant, and TA acts as molecular armor against CO poisoning. We propose an efficient interfacial coordination coating strategy, which opens up new way to regulate the interface engineering of electrocatalysts reasonably and has broad application prospects.

Ni-doped MoS2 embedded in natural wood containing porous cellulose for piezo-catalytic degradation of tetracycline.

Wood is a natural material with low cost and easy recovery, which porous, layered, excellent structure and mechanical properties make it possible to apply in wastewater treatment. We have successfully grown MoS2 on natural wood containing porous cellulose and introduced the high conductivity circuit path provided by Ni nanoparticles to construct a new piezoelectric three-dimensional wood block for the efficient degradation of tetracycline. Ni/MoS2/Wood exhibited excellent piezo-catalytic degradation performance, and the degradation rate of tetracycline reached 95.96 % (k = 0.0411 min-1) under ultrasonic vibration. After 5 cycles, the degradation rate still reached 90.20 %. In addition, Ni/MoS2/Wood was used as the reactor filler to degrade tetracycline through piezoelectric response triggered by hydrodynamic force, and the degradation rate reached 90.27 % after 60 min. Further, the mechanism and the possible degradation pathways of tetracycline degradation were proposed. This low-cost, recyclable and stable three-dimensional wood block piezoelectric material provides a new idea for the practical application of wastewater treatment.

Vaccination in children with congenital heart disease: an observational study in a Beijing hospital.

INTRODUCTION: Underimmunization of CHD children is a public health concern in China. This study aimed to analyze the vaccination status of CHD children to provide additional evidence on optimal vaccination strategies and to make suggestions to promote appropriate vaccination services for these children. METHODS: This cross-sectional study evaluated 155 CHD children who received at least one vaccine at Peking University First Hospital. Vaccine-specific immunization rates were calculated. A telephone questionnaire survey was conducted that covered the following: the prognosis, reasons for delayed vaccinations and getting vaccination in the hospital. All statistical analyses were performed using the SPSS version 22 software. RESULTS: The left-to-right shunt group involved 138 children, while the other type CHD group involved 17. The vaccination rate was the highest for MPSV-AC (87.1%) and the lowest for DTaP (40.1%). The most frequent reason for vaccination in the hospital was refusal from community health centers (61.5%). No participant reported vaccine-related adverse effects. CONCLUSIONS: The age-appropriate vaccine-specific immunization rates in CHD children are low, with the lowest for DTaP. Refusal of community health centers was the primary reason. Our findings support that clinically stable CHD children may be safely vaccinated on a schedule similar to that of ordinary children in China. IMPACT: From our investigation, we found that the age-appropriate vaccine-specific immunization rates in children with CHD in China are low, with the lowest for diphtheria and tetanus toxoid and acellular pertussis. Refusal of community health centers to vaccinate was the primary reason for the low rates. We believe our study provides additional evidence on optimal vaccination strategies for children with CHD and it can be used to develop strategies to promote appropriate vaccination services for these children.

Exploration of validity evidence for core residency entrustable professional activities in Chinese pediatric residency.

Introduction: This study seeks to explore validity and reliability evidence for core residency entrustable professional activities (CR-EPAs) that were developed by Peking University First Hospital (PKUFH) in 2020. Methods: A prospective cohort study was conducted in PKUFH. Trainers (raters) assessed pediatric residents on CR-EPAs over 1 academic year, bi-annually. Critical components within a validity evidence framework were examined: response process (rater perceptions), the internal structure (reliability and contributions of different variance sources), and consequences (potential use of a cutoff score). Results: In total, 37 residents were enrolled, and 111 and 99 trainers' ratings were collected in Fall 2020 and Spring 2021, respectively. For rater perceptions, all the raters considered CR-EPAs highly operational and convenient. In all ratings, individual EPAs correlate with total EPA moderately, with Spearman correlation coefficients spanning from 0.805 to 0.919. EPA 2 (select and interpret the auxiliary examinations), EPA 5 (prepare and complete medical documents), EPA 6 (provide an oral presentation of a case or a clinical encounter), and EPA 7 (identify and manage the general clinical conditions) were EPAs correlated with other EPAs significantly. The results of the generalizability theory indicated that the variability due to residents is the highest (nearly 78.5%), leading to a large size of the reliability estimates. The matching results indicate that the lowest error locates at 5.933. Conclusion: The rating showed good validity and reliability. The ratings were reliable based on G-theory. CR-EPAs have a magnificent internal structure and have promising consequences. Our results indicate that CR-EPAs are a robust assessment tool in workplace-based training in a carefully designed setting.

Late-onset cblC deficiency around puberty: a retrospective study of the clinical characteristics, diagnosis, and treatment.

BACKGROUND: cblC deficiency is the most common type of methylmalonic aciduria in China. Late-onset patients present with various non-specific symptoms and are usually misdiagnosed. The purpose of this study is to investigate the clinical features of patients with late-onset cblC deficiency and explore diagnosis and management strategies around puberty. RESULTS: This study included 56 patients (35 males and 21 females) with late-onset cblC deficiency who were admitted to our clinic between 2002 and September 2021. The diagnosis was confirmed by metabolic and genetic tests. The clinical and biochemical features, disease triggers, outcome, and associated genetic variants were examined. The onset age ranged from 10 to 20 years (median age, 12 years). Fifteen patients (26.8%) presented with symptoms after infection or sports training. Further, 46 patients (82.1%) had neuropsychiatric diseases; 11 patients (19.6%), cardiovascular diseases; and 6 patients (10.7%), pulmonary hypertension. Renal damage was observed in 6 cases (10.7%). Genetic analysis revealed 21 variants of the MMACHC gene in the 56 patients. The top five common variants detected in 112 alleles were c.482G > A (36.6%), c.609G > A (16.1%), c.658_660delAAG (9.8%), c.80A > G (8.0%), and c.567dupT (6.3%). Thirty-nine patients carried the c.482G > A variant. Among 13 patients who exhibited spastic paraplegia as the main manifestation, 11 patients carried c.482G > A variants. Six patients who presented with psychotic disorders and spastic paraplegia had compound heterozygotic c.482G > A and other variants. All the patients showed improvement after metabolic treatment with cobalamin, L-carnitine, and betaine, and 30 school-aged patients returned to school. Two female patients got married and had healthy babies. CONCLUSIONS: Patients with late-onset cblC deficiency present with a wide variety of neuropsychiatric symptoms and other presentations, including multiple organ damage. As a result, cb1C deficiency can easily be misdiagnosed as other conditions. Metabolic and genetic studies are important for accurate diagnosis, and metabolic treatment with cobalamin, L-carnitine, and betaine appears to be beneficial.

Comparative water footprint assessment of fuel cell electric vehicles and compressed natural gas vehicles.

Utilization of renewable energy has become a current energy development trend. In this study, the water footprints of a fuel cell electric vehicle (FCEV) and a compressed natural gas vehicle (CNG) under different fuel scenarios were evaluated. The FCEV exhibits a low water footprint of 27.2 L/100 km under steam methane reforming hydrogen production technology. Hydrogen production using steam methane reforming and water electrolysis via wind can enable the FCEV industry to save more water resources. The percentage difference between different metallic materials in automobiles was analyzed. The water consumption by steel accounted for 73.6% and 80.5%, respectively. The fluctuation law of the water footprint was analyzed based on different power structures and steel water consumption coefficients. It was found that for low steel water consumption coefficient, wind power generation is conducive to slowing down the water consumption during the entire life cycle. In addition, a sensitivity analysis was performed for the FCEV and CNG under different fuel scenarios. Fuel technology and material structure have a significant impact on the total water footprint. The results of this study can provide guidance for the layout of the automobile industry and for water-saving measures in the future.

Vitamin D Deficiency and Vasovagal Syncope in Children and Adolescents.

Aims: To investigate the association of vitamin D deficiency with cardiovascular autonomic nervous system function in children and adolescents with vasovagal syncope (VVS). Methods: This study recruited 76 pediatric patients with VVS and 15 healthy children. The 25-hydroxyvitamin D levels in serum among the participants were evaluated. Heart rate variability analysis including SDNN, rMSSD, and SDANN was tested in patients with VVS. The correlation between indices of time-domain analysis and serum vitamin D status of the children with VVS was investigated. Results: In this work, 25-hydroxyvitamin D levels in serum among VVS cases remarkably decreased compared with those among healthy controls (48.76 ± 19.25 vs. 67.62 ± 15.46 nmol/L, p < 0.01). The vitamin D deficient patients with VVS exhibited a lower rMSDD value compared to the non-deficient group with VVS (45.56 ± 16.87 vs. 61.90 ± 20.38 ms, p < 0.001, respectively). Pearson correlation analysis indicated that serum 25-hydroxyvitamin D levels had positive correlation with rMSDD values (r = 0.466, p < 0.001). Conclusions: As suggested by our data, VVS children and adolescents with vitamin D deficiency may have cardiac autonomic dysfunction and cardiac vagal tone decreases with the reduction in vitamin D level.

Prediction of intravenous immunoglobulin resistance in Kawasaki disease in children.

BACKGROUND: We aimed to explore predictive measures for intravenous immunoglobulin (IVIG) resistance in children with Kawasaki disease (KD). METHODS: Patients diagnosed with KD were enrolled in this study. Univariate analysis and multiple logistic regression were utilized to analyze the clinical features and laboratory results prior to IVIG-treatment of the two groups. Independent predictors of IVIG resistance were analyzed, and a predictive model for KD children with IVIG resistance was constructed. RESULTS: A total of 277 children with KD, 180 boys and 97 girls, aged 2-128 (median 23) months, were enrolled in the study. Compared with the IVIG-responsive group, the IVIG-resistant group had higher levels of the peripheral neutrophil count, mean platelet volume, mean platelet volume-to-lymphocyte ratio and C-reactive protein, and total serum bilirubin, but lower levels of peripheral lymphocyte count, serum albumin and serum prealbumin. Age (in months), peripheral neutrophil count, lymphocyte count and mean platelet volume and serum albumin were independent indicators for IVIG resistance by multivariate logistic regression analysis. A logistic regression model and a scoring system were set up, where cut-off values of - 0.46 and 6.5 points yielded sensitivities of 83.9% and 77.4%, and specificities of 74.8% and 61.0%, respectively. The areas under the curve (AUC) were 0.808 in the logistic regression model, and 0.750 in the scoring system. CONCLUSION: Our model for predicting IVIG-resistant children with KD, involving age (months), peripheral neutrophil count, lymphocyte count and mean platelet volume and serum albumin prior to IVIG-treatment, is helpful for clinical prediction of children with IVIG-resistant KD.

Neutrophil-to-Lymphocyte Ratio Predicts Intravenous Immunoglobulin-Resistance in Infants Under 12-Months Old With Kawasaki Disease.

Objective: We evaluated the ability of peripheral blood neutrophil-to-lymphocyte ratio (NLR) to predict the intravenous immunoglobulin (IVIG) resistance in Kawasaki disease (KD) patients under 1-year of age. Methods: A total of 92 KD patients under the age of 1-year and who were hospitalized in Peking University First Hospital from June 2007 to August 2016 were recruited in this study. The clinical and laboratory data were analyzed to see if peripheral blood NLR was useful for predicting the IVIG-resistance in KD. Results: Totally 81 out of 92 patients were IVIG responders while 11 resistant to IVIG, with no significant difference in age, gender, ratio of the number of the incomplete to the number of complete KD, and the number of patients with coronary artery lesion between two groups (p > 0.05). Peripheral blood NLR was increased significantly in IVIG-resistant children compared to the IVIG responders [2.6 (interquartile range: 1.4, 3.8) vs. 1.7 (interquartile range: 0.9, 2.3), p = 0.039]. A cut-off value of NLR of 2.51 in KD patients younger than 1-year old yielded a sensitivity of 0.545 and specificity of 0.840, respectively, in the prediction of IVIG resistance. An area under the curve of 0.692 (95% confidence interval 0.526-0.859, p = 0.039) was determined. Conclusions: The peripheral blood NLR ≥ 2.51 is useful to predict the IVIG resistance in KD patients younger than 1-year old.

Gut microbiota analysis and its significance in vasovagal syncope in children.

BACKGROUND: Vasovagal syncope (VVS) is common in children and greatly affect both physical and mental health. But the mechanisms have not been completely explained. This study was designed to analyze the gut microbiota in children with VVS and explore its clinical significance. METHODS: Fecal samples from 20 VVS children and 20 matched controls were collected, and the microbiota were analyzed by 16S rRNA gene sequencing. The diversity and microbiota compositions of the VVS cases and controls were compared with the independent sample t test or Mann-Whitney U test. The correlation between the predominant bacteria and clinical symptoms was analyzed using Pearson or Spearman correlation test. RESULTS: No significant differences in diversity were evident between VVS and controls (P > 0.05). At the family level, the relative abundance of Ruminococcaceae was significantly higher in VVS children than in controls (median [Q1, Q3]: 22.10% [16.89%, 27.36%] vs. 13.92% [10.31%, 20.18%], Z = -2.40, P < 0.05), and LEfSe analysis revealed Ruminococcaceae as a discriminative feature (linear discriminant analysis [LDA] score > 4, P < 0.05). The relative abundance of Ruminococcaceae in VVS patients was positively correlated with the frequency of syncope (r = 0.616, P < 0.01). In terms of its correlation with hemodynamics, we showed that relative abundance of Ruminococcaceae was negatively correlated with the systolic and diastolic pressure reduction at the positive response in head-up tilt test (HUTT; r = -0.489 and -0.448, all P < 0.05), but was positively correlated with the mean pressure drop and decline rate (r = 0.489 and 0.467, all P < 0.05) as well as diastolic pressure drop and decline rate at the HUTT positive response (r = 0.579 and 0.589, all P < 0.01) in VVS patients. CONCLUSION: Ruminococcaceae was the predominant gut bacteria and was associated with the clinical symptoms and hemodynamics of VVS, suggesting that gut microbiota might be involved in the development of VVS.

A New Scoring System for Prediction of Intravenous Immunoglobulin Resistance of Kawasaki Disease in Infants Under 1-Year Old.

Background: Children with Kawasaki disease (KD) under 1-year old are at high risk for intravenous immunoglobulin (IVIG) resistance. The study was designed to explore the predictive measure of IVIG resistance in infants under 1-year old with KD. Methods: This study enrolled children under 1-year old suffering from KD in Peking University First Hospital and Wuhan Children's Hospital. All infants were divided into IVIG-responsive and IVIG-resistant groups. The differences in demographic characteristics, clinical features, and laboratory examinations were compared and the risk factors of IVIG resistant KD were analyzed. Furthermore, a scoring system was developed for predicting IVIG resistance in KD infants and an external validation was performed. Result: A total of 282 infants (194 boys, median age of 7.0 months) were enrolled in this study, of whom 23 children were IVIG-resistant. Compared with IVIG-responsive infants, those in the IVIG-resistant group had a high neutrophil-to-lymphocyte ratio (NLR), high platelet-to-lymphocyte ratio (PLR), high mean platelet volume-to-lymphocyte ratio (MPVLR) in peripheral blood, and low serum albumin, and low serum sodium before IVIG therapy (all P < 0.01). Multiple regression analysis indicated that high levels of peripheral NLR and MPVLR, and low levels of serum albumin and serum sodium were independent risk factors for IVIG resistant KD infants. A scoring system, which included peripheral NLR ≥ 2.69 (1 point), MPVLR ≥ 2.78 (1 point), serum albumin ≤ 30.7 g/L (1 point), and serum sodium ≤ 135.2 mmol/L (1 point), was established. A cut-off value of a total score of 2 points or higher yielded a sensitivity of 87.0% and a specificity of 78.4%, with an area under the curve of 0.891. External validation with clinical diagnostic standard showed that a cut-off value of total score of 2 points or higher for predicting the IVIG-resistance yielded a sensitivity of 70.0% and a specificity of 75.1%. Conclusion: For the first time, we proposed a predictive model of IVIG resistance in KD infants under 1-year old. The scoring system, which accounts for baseline peripheral NLR, MPVLR, and serum albumin and sodium, predicts with relatively high sensitivity and specificity for IVIG-resistant infants with KD under 1-year old.

Serum Resistin Negatively Correlates with Clinical Severity of Postural Tachycardia Syndrome in Children.

This study was designed to analyse the serum resistin level in children with postural tachycardia syndrome (POTS) and its clinical significance. Twenty-one children with POTS and 31 healthy children as controls participated in the study. Clinical characteristics, heart rate and blood pressure in the supine and upright positions were monitored and collected during an upright test, and the symptom scoring of POTS patients was recorded. The serum resistin levels of patients in both groups were determined by enzyme-linked immunosorbent assay. The change in serum resistin levels in the POTS group before and after standing, as well as its correlation with symptom scores and change in heart rate after standing, was analysed. Compared with the control group, the serum resistin levels in the POTS group were significantly increased (P < 0.01). The serum resistin levels in the POTS group before and after standing did not differ (P > 0.05). There was a negative correlation between the serum resistin levels and a change in heart rate from the supine to upright position (correlation coefficient = -0.615, P < 0.01). Moreover, serum resistin levels were negatively correlated with symptom scores (correlation coefficient = -0.493, P < 0.05). Serum resistin levels in children with POTS were significantly higher than those in healthy children and negatively correlated with a change in heart rate from the supine to upright position and symptom scores. These results suggest a protective role of increased resistin in the pathogenesis of POTS.

The configuration exchanging theory for transport properties and glass formation temperature of ionic liquids.

Understanding molecular motion in terms of molecular structure is an important issue for microscopic understanding of the nature of transport properties and glass transition, and for design of structured materials to meet specific demands in various applications. Herein, a novel molecular mechanism is proposed to connect macroscopic motion in ionic liquids with molecular structure via conformational conversions of the constituent ions or of the cation-anion pairs. New equations for description of relaxation time, diffusion coefficient, molar conductivity, and viscosity of ionic liquids are established. The equation parameters, which were determined from the temperature dependent heat capacities, self-diffusion coefficients, molar conductivities, and viscosities of typical ionic liquids, were used to produce predictions for the corresponding properties of other ionic liquids and for the glass transition temperatures of representative ionic liquids. All predictions are in nice agreements with the experimental results.

[Clinical analysis and follow-up study of cardiavascular system involvement in 10 children with methylmalonic aciduria combined with hyperhomocysteinemia].

OBJECTIVE: To study the clinical features and treatment outcomes of cardiovascular system involvement in children with methylmalonic aciduria combined with hyperhomocysteinemia (MMACHC). METHODS: The clinical data of 10 children with methylmalonic aciduria combined with hyperhomocysteinemia and who had cardiovascular system involvement were retrospectively analyzed and the treatment outcomes were followed up. RESULTS: In the 10 patients, there were 4 cases with initial presentations of cardiovascular system symptoms such as shortness of breath and dyspnea, 3 cases with urinary tract symptoms such as edema, hematuria and proteinuria, and 3 cases with nervous system symptoms such as developmental retardation and convulsions. The 10 patients had different types and severity of cardiovascular injuries. After 3 months to 8 years of follow-up, the congenital heart defects resolved naturally in 2 cases, and the patient with arrhythmia had no obvious changes. In 5 cases of hypertension, blood pressures recovered to normal in 3 cases, and 1 case was lost to follow-up. In 5 patients with pulmonary hypertension, 2 died, 2 recovered, and 1 case had mildly elevated pulmonary artery pressure. Seven patients underwent MMACHC gene testing, and 5 showed c.80A>G mutations. CONCLUSIONS: Metabolic disease should be taken into account for the children with unexplained pulmonary hypertension and hypertension with the onset of the shortness of breath and dyspnea. The severity of cardiovascular system involvement might be one of the most important factors affecting the prognosis of children with MMACHC. Cardiavascular system involvement of the patients may be related to MMACHC c.80A>G mutations.

Adrenomedullin alleviates pulmonary artery collagen accumulation in rats with pulmonary hypertension induced by high blood flow.

Collagen accumulation is one of the important pathologic changes in the development of pulmonary hypertension. Previous research showed that adrenomedullin (ADM) mitigates the development of pulmonary hypertension. The present study explored the role of ADM in the development of pulmonary artery collagen accumulation induced by high pulmonary blood flow, by investigating the effect of ADM [1.5 µg/(kg h)] subcutaneously administered by mini-osmotic pump on pulmonary hemodynamics, pulmonary vascular structure and pulmonary artery collagen accumulation and synthesis in rats with high pulmonary blood flow induced by aortocaval shunting. The results showed that ADM significantly decreased mean pulmonary artery pressure (mPAP) and the ratio of right ventricular mass to left ventricular plus septal mass [RV/(LV+SP)], attenuated the muscularization of small pulmonary vessels and relative medial thickness (RMT) of pulmonary arteries in rats with high pulmonary blood flow. Meanwhile, ADM ameliorated pulmonary artery collagen deposition represented by a decrease in lung tissue hydroxyproline, collagens I and III content and pulmonary artery collagens I and III expression, reduced collagen synthesis represented by a decrease in lung tissue procollagens I and III mRNA expression. The results suggest that ADM plays a protective role in the development of pulmonary hypertension induced by high blood flow, by inhibiting pulmonary procollagen synthesis and alleviating pulmonary artery collagen accumulation.

Diagnostic value of serum brain natriuretic peptide in syncope in children and adolescents.

AIM: This study was designed to evaluate the diagnostic value of B-type natriuretic peptide (BNP) in syncope in children and adolescents. METHODS: Serum BNP concentration was measured by electrochemiluminescence assay in 62 consecutive children and adolescents hospitalized for syncope. RESULTS: Of the 62 children and adolescents hospitalized for syncope, 39 had noncardiac syncope, of whom 37 (59.7%) had autonomic-mediated reflex syncope and two (3.2%) had syncope of unknown cause. Twenty-three patients (37.1%) had cardiac syncope: 11 of these had cardiac arrhythmias and 12 had structural cardiac/cardiopulmonary disease. Patients with cardiac syncope had significantly higher serum BNP than those with non-cardiac syncope (958.78 ± 2443.41 pg/mL vs 31.05 ± 22.64 pg/mL, p < 0.05). Logistic multivariate regression analysis revealed that urinary incontinence during syncopal episodes, ECG abnormalities and increased serum BNP levels were independent predictors of cardiac syncope. At a cut-off value of 40.65 pg/mL, serum BNP was associated with significant risk of a cardiac cause of syncope, with sensitivity of 73.9% and specificity of 70.0% for distinguishing cardiac syncope from noncardiac syncope. CONCLUSION: Serum BNP was helpful in differentiating cardiac syncope from noncardiac syncope in children and adolescents.

Sulfur dioxide derivatives improve the vasorelaxation in the spontaneously hypertensive rat by enhancing the vasorelaxant response to nitric oxide.

The present study was designed to explore the role of sulfur dioxide (SO(2)) in the regulation of vasorelaxation in the spontaneously hypertensive rat (SHR). Twenty-two Wistar rats and 15 SHRs were divided randomly into the following groups: Wistar-Kyoto (WKY) control (n = 8), WKY+Na(2)SO(3)/NaHSO(3) (n = 8), WKY+L-aspartic acid-ß-hydroxamate (HDX) (n = 6), SHR control (n = 8) and SHR+Na(2)SO(3)/NaHSO(3) (n = 7). Their blood pressure in vivo was measured by tail plethysmography. The vasorelaxant response of the thoracic aorta to acetylcholine (Ach) and sodium nitroprusside (SNP) in all rats was tested, respectively, in the experiment. At the same time, the SO(2) content of the WKY aorta after incubation with HDX and the vasorelaxant response to Ach after incubation with HDX were quantified. Nitric oxide (NO) production in the aorta of all rats was determined. We also measured the vasorelaxant responses of WKY aorta to different concentrations of SO(2) after incubation with the NO inhibitor, N(G)-nitro-L-arginine methyl ester (L-NAME). The blood pressure decreased significantly in SHRs treated with SO(2) derivatives (P < 0.05). Reduction of endogenous SO(2) in WKY vessels resulted in a decrease in the vasorelaxation induced by Ach. Vasorelaxation in response to both Ach and SNP increased in SHRs treated with SO(2) derivatives compared with SHR controls, but decreased in WKY given HDX compared with WKY controls (P < 0.05). The NO level in arterial tissues increased in SHRs treated with SO(2) derivatives (P < 0.05). However, the vasorelaxant response to SO(2) derivatives in the presence of L-NAME decreased markedly compared with WKY controls. The results suggest that SO(2) reduced blood pressure and increased vasorelaxation in SHR arteries via enhancing the vasorelaxant response to NO in isolated aortic rings and increasing the NO level of aortic tissues.

[Adrenomedullin alleviates collagen accumulation in pulmonary arteries of rats with hypoxic pulmonary hypertension].

OBJECTIVE: To observe the effect of adrenomedullin (ADM) on the pulmonary vascular collagen metabolism in hypoxic rats in order to study the effect of ADM on chronic hypoxic pulmonary vascular structural remodeling and its possible mechanism. METHODS: Nineteen male Wistar rats were randomly divided into three groups: normal control (n=6), hypoxia (n=7) and ADM-treated hypoxia (n=6). ADM was subcutaneously administered into rats of the ADM-treated hypoxia group by mini-osmotic pump (300 ng/h) for two weeks. After two weeks of hypoxic challenge, mean pulmonary arterial pressure (mPAP) was evaluated using a right cardiac catheterization procedure. The ratio of right ventricular mass to left ventricular plus septal mass[RV/ (LV+S)] was measured. The changes of pulmonary vascular microstructure were observed. Meanwhile, the expression levels of collagen I, collagen III and transforming growth factor (TGF)-ß in pulmonary arteries were detected by immunohistochemical assay. RESULTS: mPAP and RV/(LV+S) increased significantly in the hypoxia group compared with normal controls (P<0.01). The muscularization of small pulmonary vessels and the relative medial thickness of pulmonary arteries increased obviously in the hypoxia group compared with those in the normal control group (P<0.01). Meanwhile, the expression levels of collagen I, collagen III and TGF-ß of pulmonary arteries in the hypoxia group increased markedly compared with those in the normal control group. However, mPAP and RV/(LV+S) were significantly reduced in the ADM-treated hypoxia group compared with those in the hypoxia group (P<0.01). ADM ameliorated pulmonary vascular structural remodeling of hypoxic rats, with a decrease in the expression of collagen I, collagen III and TGF-ß of pulmonary arteries. CONCLUSIONS: ADM might play a regulatory role in the development of hypoxic pulmonary hypertension and hypoxic pulmonary vascular remodeling, through inhibiting the expression of TGF-ß and alleviating the collagen accumulation of pulmonary arteries.

[Clinical characteristics and follow-up study of tachycardia-induced cardiomyopathy in 12 children].

OBJECTIVE: Tachycardia induced cardiomyopathy (TIC), secondary to various tachyarrhythmias, is a reversible condition which can lead to cardiac enlargement and heart failure. The impairment of both structure and function of heart can be reverted completely or partially if tachyarrhythmias are ceased without delay. This study aimed to explore the clinical characteristics, therapeutic regimen and outcome of TIC in children. METHODS: Clinical data of 12 children with TIC, who came from Peking University First Hospital from Feb. 2003 to Jun. 2009, were retrospectively analyzed and followed up. The echocardiogram data on admission were compared with those from 12 homochronous cases with idiopathic dilated cardiomyopathy matched with 12 TIC cases in age and gender. RESULTS: Atrial tachycardia is the commonest arrhythmia in 12 TIC cases (75%). Four cases underwent catheterization for radiofrequency ablation and all succeeded. The cardiac rhythm of 6 out of 8 cases treated with drugs became sinus rhythm after 3 days to 2 weeks antiarrhythmic drugs treatment. The remaining 2 cases still retained atrial rhythm, but the ventricular heart rates declined to normal. The left ventricular end-diastolic dimensions of the 12 cases were decreased compared with those of pretherapy [(37.5 ± 5.3) mm vs. (43.0 ± 5.7) mm, P < 0.01], and the left ventricular ejection fractions were increased [(60.5% ± 5.6%) vs. (33.7% ± 10.3%), P < 0.01], after (3.4 ± 2.3) months. In our (4.3 ± 2.4) year-follow-up, all cases were fine, except in one case the tachyarrhythmia relapsed because of discontinuation of the drug treatment by her parents. The left ventricular end-diastolic dimensions in 12 TIC cases were smaller than those of the 12 age- and gender-matched idiopathic dilated cardiomyopathy [(43.0 ± 5.7) mm vs. (54.8 ± 7.5) mm, t = 7.9, P < 0.01], and the ejection fractions were higher [(33.7% ± 10.3%) vs. (21.8% ± 7.5%), t = 3.7, P < 0.01]. CONCLUSION: The diagnosis of TIC should be considered for the children with tachycardia, cardiac enlargement and cardiac insufficiency. The degree of cardiac enlargement and cardiac insufficiency might be of value for the differential diagnosis between TIC and idiopathic dilated cardiomyopathy. The rhythm control and ventricular rates control could all result in a favorite therapeutic efficacy.