[A cohort study on the new infections and natural clearance of anal human papillomavirus types 16 and 18 in men who have sex with men]

Objective: To understand the infection status and elimination of anal human papillomavirus (HPV) among men who have sex with men (MSM) in Urumqi, Xinjiang. Methods: The sample size formula in cohort study, a dynamic cohort study method, was used, with the sample size estimated to be 712 according to the new infection rate of HPV16. With the help from non-government organzitions in Urumqi, we recruited 810 MSMs by the snowballing method, and a follow-up program was carried every six months. Anal exfoliated cells were collected to analyze HPV type 16 and 18 infection rates. For statistical analyses, Poisson regression was used to estimate the density of new infections and persistent infections. Cox proportional hazard model was used to explore the influencing factors on both new and persistent infections and the diseases' natural clearing. Results: A total of 810 MSM were recruited, and 482 MSMs with the number of follow-ups more than 2 times were included in the analysis, with the total follow-up numbers as 994.7 person-years. The median number of follow-up and follow-up times was 4 (P₂₅,P₇₅:3,5) times , and 2.2 (P₂₅,P₇₅:1.8, 2.6) years. The baseline infection rates of HPV16 and HPV18 were 8.5% (41/482) and 3.3% (16/482), respectively. And the baseline mixed infection rate of the two types was 0.6% (3/482). The first new infection densities of HPV16 and HPV18 were 10.06 (95%CI:8.12-12.45)/100 person-years and 5.24 (95%CI:3.95-6.96)/100 person-years. The rate of natural infection clearance of HPV16 and HPV18 were 71.2% (89/125) and 71.8% (46/64), respectively. The natural clearance rate of HPV18 after 1.5 years follow-up was higher than HPV16 (97.7% vs. 94.1%). The persistent infection rate of HPV16 and HPV18 were 4.5% (20/441) and 1.7% (8/466), respectively. The risk of persistent HPV16 infection among unmarried subjects was lower than that of married subjects (aHR=0.29,95%CI:0.12-0.71). The natural clearance rate of HPV18 without condom use in anal intercourse in the last six months was 2.63 times higher than that of condom use (95%CI:1.08-6.42). Conclusions: HPV16 and 18 new infections are more common among MSM in Urumqi, and the natural clearance rate is higher. Compared with HPV18, HPV16 has a higher density of new and persistent infections, a low natural clearance rate, and a greater risk of the diseases.

An incremental feeding pattern for Guangdong Small-ear Spotted gilts during gestation: effects on stillbirth rate and muscle weight of progeny

While an appropriate feed intake is crucial for the reproductive performance of sows, there is a lack of recommendations currently for feed allowance of Guangdong Small-ear Spotted gilts during gestation. The effects of 2 different feeding patterns during gestation on the reproductive performance of Guangdong Small-ear Spotted gilts were investigated by assigning 80 gilts to 2 feeding pattern groups with a randomized complete block design in accordance with initial body weight and back fat thickness, followed by treatment with an incremental feeding pattern (IFP) and a concaved feeding pattern, respectively, with no difference in total feed intake. The IFP group showed a significant decrease in the stillbirth rate (P < 0.05) and an upward trend in piglet mean birth weight (P = 0.06). Furthermore, the IFP group exhibited an increase in the weights of stomach, supraspinatus tendon, triceps, and psoas minor in neonatal piglets (P < 0.05). Overall, the results of the present investigation showed that IFP could significantly reduce the stillbirth rate of Guangdong Small-ear Spotted gilts and increase the muscle weight of progeny.

Infestation and distribution of chigger mites on Brown rat (Rattus norvegicus) in Yunnan Province, Southwest China

Chigger mites is a group of arthropods and some of them are vectors of scrub typhus. As a common synanthropic rodent species, the Brown rat (Rattus norvegicus) often harbors lots of ectoparasites including chigger mites. According to some "data mining" strategies, the present study took the advantage of the abundant original data from a long-term field ecological investigation between 2001 and 2015 to make a detailed analysis of chigger mites on R. norvegicus in Yunnan Province, Southwest of China. From 18 of 33 investigated counties, only 1414 chigger mites were collected from 1113 Brown rats with relatively low infestations. The 1414 individual chigger mites were identified as comprising 61 species, 11 genera and 2 subfamilies of the family Trombiculidae with a high species diversity (S=61, H'=3.13). Of 61 mite species, there were four main species, Walchia ewingi, Ascoschoengastia indica, W. koi and A. rattinorvegici, which accounted for 44.41% of the total mites. All the chigger mites were of aggregated distribution among different individuals of R. norvegicus. The Brown rats in the outdoor habitats harbored much more individuals and species of chigger mites with a higher mean abundance (MA=1.46) and mean intensity (MI=12.53) than in the indoor habitats (P<0.05). The overall infestation of the rats was significantly higher in the mountainous landscapes than in the flatland landscapes (P<0.001). The species similarity (C_ss) of the mites on the male and female rats reached 64.44% with sex biased infestations. The male rats harbored more species and individuals of the mites than the female rats. The adult rats harbored more species and individuals of the mites than the juvenile rats. The species abundance distribution of the mites was successfully fitted by Preston's lognormal model with ŝ(R)=15e^{-[0.31(R-1)]2} (α=0.31, R²=0.95). On the basis of fitting the theoretical curve by Preston's model, the total mite species on R. norvegicus was estimated to be 86 species, and 25 rare mite species were missed in the sampling field investigation. The curve tendency of the species-plot relationship indicates that R. norvegicus have a great potential to harbor many species of chigger mites, and more species of the mites would be collected if more rats are sampled.

Muscone alleviates myocardial ischemia-reperfusion injury via inhibition of oxidative stress and enhancement of SIRT3

This study aimed at probing into the function of muscone in ameliorating myocardial ischemiareperfusion (I/R) injury and exploring the underlying mechanism. To analyze the function of muscone, H9c2 cardiomyocytes were treated with hypoxia/reoxygenation (H/R) and Sprague-Dawley (SD) rats were treated with left anterior descending (LAD) of the coronary artery ligation for 30 min and reperfusion for 2 h to induce myocardial I/R injury. Quantitative real-time polymerase chain reaction (qRT-PCR) and Western blot were used to detect the expression of SIRT3. MTT assay and TUNEL assay were performed to investigate H9c2 viability and apoptosis, respectively. ELISA was employed to determine the expressions of inflammatory cytokines TNF-α, IL-6 and IL-1β, and myocardial injury markers CK and LDH. Oxidative stress markers MDA and SOD, and ROS expression levels were also detected. SIRT3 inhibitor 3-TYP was used to further confirm whether muscone worked via the augmentation of SIRT3. Herein, we found that muscone significantly inhibited inflammation and oxidative stress in H9c2 cardiomyocytes in a dose-dependent manner. H9c2 viability was promoted by muscone while apoptosis was inhibited. In SD rats, pre-treatment of muscone alleviated I/R injury-induced cardiac function dysregulation and left ventricle remolding. Furthermore, muscone increased SIRT3 expression at both mRNA and protein levels. With 3-TYP inhibiting SIRT3, the protective effects of muscone in H9c2 cardiomyocytes and SD rats were all significantly alleviated. In summary, muscone can attenuate inflammation, oxidative stress and cardiomyocytes injury in H9c2 cells treated with H/R and alleviate myocardial I/R injury of SD rats, which are dependent on SIRT3.

[The characteristics and citation analysis of the publications in National Medical Journal of China during 2016]

Objective: To analyze the characteristics and citations of articles in National Medical Journal of China (NMJC) during 2016, and to discuss the academic level and quality of the journal. Methods: All the literature published in NMJC during 2016 were retrieved through the Chinese Medical Citation index, and the citation frequency data in China's core journals of science and technology from January 2017 to December 2018 was obtained through Institute of Scientific and Technical Information of China. The citation status of articles published in NMJC was statistically analyzed by the method of literature metrology. The main indicators included the citation rate of articles published in each year, the citation frequency of all articles, the citation status of individual papers and authors, the regional and high-yield institution distribution of cited authors, and the main citation journals. Results: In 2016, a total of 962 articles were published in 22 columns of NMJC. The total number of published pages was 3 940, and the average number of articles was 4.09 pages. A total of 28 key topics have been published. The total citation was 2 077 times, with 2.16 times per paper. Among them, 322 papers were not cited, accounting for 33.47%. The maximum citation frequency of a single paper was 66 times. There were good citations in the columns of Guidelines, Epidemiology, New technology and methods, Clinical research and Editorial. Oncology, neurology/psychiatry, imaging/ultrasound/radiology, respiratory medicine and orthopedics accounted for a large part [40.43% (389 articles)]. Articles in neurosurgery, respiratory medicine, preventive medicine and gastrointestinal surgery were all cited with high frequency (all ≥2.75 times/article). A total of 483(50.21%) articles had obtained fund support, and the rate (68.12%) of them cited was slightly higher than that of articles without fund support (64.93%). A total of 23 articles were cited ≥10 times, and 16 first authors were cited ≥10 times. In addation, 26 corresponding authors were cited ≥10 times and 10 institutions were cited more than 15 times. The authors of the cited papers were distributed in 29 provinces (autonomous regions, municipalities directly under the central government), and there were more articles and higher total citation frequency in Beijing, Shanghai, Jiangsu and Tianjin. From 2017 to 2018, papers published in NMJC were cited 2 077 times by a total of 490 journals. Conclusions: The guidelines published in NMJC is highly cited. The editorial department should adjust the column setting timely, strengthen the planning of key topic selection and the solicitation and publicity of excellent papers, and further improve the influence of the magazine.

[Application of restricted cube spline in cox regression model]

Restricted cubic spline Cox proportional hazard regression model analysis is an important method of epidemiological multivariate survival analysis. By comparing the typical Cox regression model and the restricted cubic spline Cox regression model, this study expounds the limitations of the typical Cox regression model, and explains the basic principles and implementation process of the restricted cubic spline Cox proportional hazard regression model. When the follow-up data does not meet the application conditions of the typical Cox regression model, this method can be used to realize the correlation analysis between continuous exposure and outcomes.

[Long-term outcome of percutaneous balloon aortic valvuloplasty for children with congenital aortic valve stenosis]

Objective: To assess the efficacy and long-term outcome of percutaneous balloon aortic valvuloplasty (PBAV) for children with congenital aortic stenosis (CAS) and to explore risk factors for significant aortic regurgitation (AR) and reintervention after PBAV during follow up. Methods: This was a retrospective study. Children (≤18 years old) with CAS, who underwent PBAV in Guangdong Provincial Hospital from January 2004 to December 2018, were included in this study. Demographic, preoperative transthoracic echocardiography (TTE) and surgical data were collected. Postoperative complications were closely observed, and the patients were followed up at 1, 6, 12 months after the operation, and then at one year interval thereafter. Endpoint events included significant AR and reintervention. Reintervention was defined as any intervention that needed to be performed on the valve for various reasons, including re-PBAV, surgical valvuloplasty and valve replacement. Significant AR was defined as AR grade≥3 by TTE criteria. The results of the last TTE examination before the end of the study were collected. The Kaplan-Meier curve for long-term AR-free and intervention-free survival was plotted. Cox regression model was used to further analyze the risk factors for significant AR and reintervention after PBAV in CAS patients. Results: A total of 55 patients were enrolled in this study, and the age was 4.6(1.6, 6.5) years, with 37(67.3%) males. The peak systolic valve gradient fell from (80.3±30.6)mmHg to (38.5±18.5)mmHg(P<0.001, 1 mmHg=0.133 kPa). Surgical success rate was 89% (49/55). Acute post-PBAV AR occurred in 18 patients, including 3 patients with RA≥3 grade. In-hospital complications occurred in 6 patients (2 deaths, 2 cases of transient arrhythmia, and 2 cases of femoral artery embolization). Fifty patients accomplished the follow-up and the follow-up time was 6.2(3.4, 8.5) years. Significant AR was found in 20 patients. Significant AR-free survival rate was 53% at 5 years and 19% at 10 years. Reintervention was performed in 11 patients (4 with valvuloplasty and 7 with valve replacement), and the 5-year and 10-year intervention-free survival rates were 87% and 62%, respectively. Multivariate Cox regression analysis showed that acute post-PBAV AR was a risk factor for long-term significant AR (HR=2.398, 95%CI 1.007-5.712, P=0.048). Post-PBAV residual pressure gradient ≥ 35 mmHg (HR=4.747, 95%CI 1.116-19.329, P=0.030)and acute post-PBAV AR (HR=5.104, 95%CI 1.083-24.065, P=0.039)were risk factors for re-intervention. Conclusions: PBAV is safe and effective in the treatment of CAS in children, but attention should be paid on significant AR post procedure. Acute post-PBAV AR is a risk factor for re-intervention and significant AR post PBAV, and high post-PBAV residual pressure gradient is a risk factor for re-intervention.

MiR-638 regulates gastric cardia adenocarcinoma cell proliferation, apoptosis, migration and invasion by targeting MACC1

Gastric cardia adenocarcinoma (GCA) is one of the most common types of cancer and the incidence is increasing globally. MicroRNAs (miRNAs) have been reported to play critical roles in the progression of GCA. However, the exact role of miR-638 in GCA and its underlying mechanism remain largely unknown. The expression levels of miR-638 and metastasis-associated in colon cancer 1 (MACC1) were measured by quantitative real-time polymerase chain reaction (qRT-PCR). Cell proliferation, apoptosis, migration and invasion were detected by Cell Counting Kit-8 (CCK-8) assay, flow cytometry and transwell assay, respectively. Western blot analysis was performed to determine the protein levels of cleaved-caspase 3 (C-caspase 3) and MACC1. The possible binding sites of miR-638 and MACC1 were predicted by TargetScan online software and confirmed by dual-luciferase reporter assay and RNA immunoprecipitation (RIP) assay. A xenograft model was established to investigate the roles of MACC1 in GCA in vivo. The expression of miR-638 was evidently reduced and MACC1 expression was obviously enhanced in GCA tissues and cells. Overexpression of miR-638 or knockdown of MACC1 inhibited cell proliferation, migration and invasion but increased apoptosis in GCA cells. Moreover, MACC1 was a direct target of miR-638 and its upregulation attenuated the inhibitory effect of miR-638 overexpression on the progression of GCA. In addition, overexpression of miR-638 significantly decreased tumor growth by downregulating MACCI in vivo. In conclusion, miR-638 overexpression suppressed cell proliferation, migration and invasion but induced cell apoptosis by targeting MACC1 in GCA cells, providing a potential therapeutic strategy for the treatment of GCA.

Beneficial effect of Rhodopseudomonas palustris on in vitro rumen digestion and fermentation

As a member of photosynthetic bacteria, Rhodopseudomonas palustris, which has extraordinary metabolic versatility, has been applied as one of potential probiotics in feed industry. To explore whether R. palustris can increase rumen microbial viability and thus improve microbial fermentation, a 2×5 factorial experiment was conducted to evaluate the effect of R. palustris at dose rates of 0, 1.3, 2.6, 3.9, 5.2×10⁶ cfu/ml on ruminal fermentation of two representative total mixed rations (HY, a ration for high-yield (>32 kg/d) lactating cows; LY, a ration for low-yield (<25 kg/d) lactating cows). After a 48 h in vitro rumen incubation, both rations resulted in different fermentation characteristics. The HY in comparison with LY group presented greater in vitro dry matter disappearance (IVDMD), cumulative gas production (GP₄₈) and total volatile fatty acids (VFA, P<0.01). Increasing R. palustris addition linearly increased IVDMD (P<0.01) and GP₄₈ (P<0.05), and the IVDMD increment in response to R. palustris addition was greater in LY than HY group (6.4% vs 1.4%). Meanwhile, increasing R. palustris addition also linearly enhanced microbial protein synthesis and increased total VFA production (P<0.01), especially in LY group (up to 21.5% and 24.5% respectively). Unchanged acetate and declined propionate in molar percentage were observed in response to the R. palustris addition. Furthermore, increasing R. palustris addition altered fermentation gas composition in which molar O₂ proportion in headspace of fermentation system was linearly reduced by 46.1% in LY and 32.9% in HY group, respectively (P<0.01), and methane production in both ration groups was enhanced by 1.9-4.1% (P=0.02). In summary, the R. palustris addition exhibited high potential for promoting the growth of rumen microorganism and enhancing microbial fermentation towards non-glucogenic energy supply by maintaining an anaerobic environment to microbe equilibrium.

P4166Efficacy and safety of novel biodegradable device for closure of atrial septal defect: from preclinical study to first-in-man experience

Background

closure of atrial septal defect (ASD) has emerged as the treatment of choice for the majority of defect. The biodegradable ASD closure device is a novel, absorbable device made of poly-L_latic acid (PLLA). This study evaluates the feasibility, safety and effectiveness of PLLA biodegradable ASD closure device in a swine model and for the first time in human.

Objective

The study reports on the 24- and 36- month follow-up results of PLLA device implanted in a swine model and the first-in- man experience with 6-month follow-up.

Method

Preclinical study was done in a swine ASD model. In a clinical setting, 5 pediatric patients with a secundum ASD who a clinically left-to-right shunt were enrolled in our center. Percutaneous ASD closure procedure with PLLA device was performed with fluoroscopic and transcatheter echocardiography (TTE) guidance. Procedure results and clinical outcomes at 1 day, 30 days, 3 months and 6 months after closure procedure were analyzed.

Results

24- and 36-month follow-up results of preclinical study demonstrated that the PLLA device exhibited good endothelialization and degradability in a swine model. In clinical study, device implantation was successfully achieved in all of 5 patients (median age, 3.6 years; range, 3.1–6.5 years). The mean ASD size was (13.4±2.4)mm (range, 10–16mm). The mean pulmonary-to-systemic blood flow ratio (Qp:Qs) was (1.7±0.2):1 with a range of 1.5:1 to 2.0:1. The mean procedure time and the mean fluoroscopy time were (36.2±11.3) and (6.4±1.0)minutes, respectively. There was no evidence of short-term complications related to the device or the delivery system. No device dislodgement, significant aortic valve or mitral valve regurgitation, new onset cardiac arrhythmia, or other adverse events were reported.

Characteristics and procedure data of the 5 patients who underwent ASD closure procedure with PLLA device Patient No. Age Weight Gender Defect size Qp:Qs Mean Pulmonary Pressure Device size (mm) Sheath (Fr) Procedure time Fluoroscopy time Immediate residual shunt (years) (kg) (mm) (mmHg) (mm) (Fr) (min) (min) 1 4.9 23.5 Male 17 1.7:1 22 24 12 52 7.6 None 2 3.1 10.0 Male 14 2.0:1 19 20 12 26 5.4 None 3 6.5 21.0 Male 15 1.8:1 22 20 12 31 6.0 None 4 3.2 14.5 Female 12 1.5:1 13 18 10 44 7.3 None 5 3.6 12.5 Male 10 1.5:1 17 14 10 28 5.5 None

Conclusion

This study is the first to demonstrate the feasibility, safety and effectiveness of PLLA biodegradable device in human, with no evidence of short-term complications and a high rate of early shunt closure.

Acknowledgement/Funding

National Key R&D Program of China (Grant Number: 2016 YFC1100305)

[Analysis of 30 cases of inherited cardiac arrhythmia syndrome in children]

Objective: To analyze and summarize the diagnosis and treatment experience of common inherited cardiac arrhythmia syndrome in pediatric patients, and explore the most appropriate therapy. Methods: A retrospective review identified 30 pediatric cases (19 males, 11 females) diagnosed with long QT syndrome (LQTS), Brugada syndrome (BrS), catecholaminergic polymorphic ventricular tachycardia (CPVT), hypertrophic cardiomyopathy (HCM), arrhythmogenc right ventricular cardiomyopathy (ARVC) from January 2008 to December 2018 in the Pediatric Cardiology Department, Guangdong Provincial People's Hospital. Data obtained included the diagnosis, treatment and follow-up outcome. Results: The most common inherited cardiac arrhythmia syndromes were LQTS (n=14) including 1 case with epilepsy, CPVT (n=5), HCM (n=7), ARVC (n=1), and BrS (n=3). Twenty-seven cases were admitted to hospital due to syncope, whereas the remaining 3 cases of BrS had not presented with syncope before admission. The average onset age of inherited arrhythmia was (10.0±3.3) years. Genetic testing was performed on 20 patients. The median follow-up time was 40 months. Among 15 patients who underwent implantable cardioverter defibrillator (ICD) and survived, 2 patients had frequent ICD discharge. One patient underwent radiofrequency ablation, and the other one received left cardiac sympathetic denervation and an increased ICD defibrillation threshold, and the number of ICD discharge was significantly reduced. Among 10 patients who received drug therapy, 4 patients including two patients who discontinued treatment without advices died. Two patients whose parents refused treatment died, 1 case diagnosed with unexplained sudden cerebral death, and the remaining 2 cases without indication for drug therapy survived without any treatment. Conclusions: Mortality rate is high in pediatric patients with inherited cardiac arrhythmia and syncope. The therapeutic effect of drugs are not satisfactory, ICD implantation is the most effective treatment to prevent sudden cardiac death currently, but the postoperative frequent discharge should be brought to the forefront and handled in time.

Cooperation between galanin and insulin in facilitating glucose transporter 4 translocation in adipose cells of diabetic rats

The glucose transporter 4 (GLUT4) translocation is a vital link of insulin-induced glucose uptake in adipose tissue and skeletal muscle. It is an important topic in anti-diabetic research to explore novel agents to facilitate the role of insulin. The aim of this study was to verify the hypothesis that neuropeptide galanin may enhance insulin-induced GLUT4 translocation to increase glucose uptake in adipose tissue of type 2 diabetic models. Insulin and/or galanin were injected respectively or cooperatively into type 2 diabetic rats once a day for fifteen days. The results showed that administration of galanin significantly enhanced insulin-induced GLUT4 and vesicle-associated membrane protein 2 (VAMP2) translocation, Akt phosphorylation and glucose uptake, but not GLUT4 mRNA and protein expression levels in adipose cells. The beneficial roles of galanin on insulin-induced events may be blocked by MK-2206, an Akt inhibitor, indicating that the Akt phosphorylation is essential for promoting impact of galanin on the insulin-induced events. These results suggest that galanin may benefit insulin-induced GLUT4 and VAMP2 translocation, and subsequent glucose uptake via the activated Akt-VAMP2-GLUT4 pathway in adipose cells. These findings deepen our understanding of the anti-diabetic effect of galanin and its mechanism.

[A long-term follow-up study of cardiac resynchronization therapy for children with right ventricle-paced heart failure]

Objective: To evaluate the long-term effects of cardiac resynchronization therapy (CRT) in children with right ventricle-paced heart failure. Methods: Five children with chronically right ventricular-paced heart failure underwent operation of upgrading to CRT in Guangdong Cardiovascular Institute between July 2009 to January 2015. The first time the patients were implanted with endocardial permanent pacemaker was (11.6±4.6) years old. The New York Heart Association (NYHA) functional classification, QRS duration, left ventricular end diastolic diameter (LVDd), left ventricular ejection fraction (LVEF), standard deviation of peak systolic time of left ventricular wall (TS-SD) and follow-up data were retrospectively analyzed. Comparison between pre-and post-operation was performed using paired t test. Results: CRT significantly improved the NYHA class to Ⅰ-Ⅱdegree, reduced the QRS duration ((126±9)vs. (182±21)ms, t=-7.480, P=0.002) and the Z-score of LVDd (2.8±1.1 vs. 4.7±0.9, t=-2.880, P=0.045), and increased the LVEF (43%±10% vs. 28%±6%, t=3.350, P=0.029). No significant difference was found regarding the TS-SD ((48±17)vs. (95±41)ms, t=-2.240, P=0.090) pre- and post-CRT. The longest follow-up period was 9 years. During follow-up, 1 case died of ventricular fibrillation 2 years after upgrading, and 2 cases underwent CRT replacement due to battery depletion 7.2 years and 5.8 years after upgrading, respectively. Conclusion: CRT could be considered for children with chronically right ventricular-paced heart failure and improve heart function significantly.

Microwave-induced release and degradation of airborne endotoxins from Escherichia coli bioaerosol

Endotoxins are widely distributed toxins in the outer cell-wall membranes of Gram-negative bacteria and other microorganisms. Chronic exposure to endotoxins can induce and exacerbate airway symptoms and diseases. However, the release and degradation of airborne endotoxins from bioaerosol by microwave (MW) irradiation have not yet been reported. This study investigated the distribution and fate of airborne endotoxins during MW irradiation process, as well as the kinetics and thermodynamics of the degradation of airborne endotoxins. Results showed that MW irradiation induced cell lysis, thus considerably increasing the proportion of cells with ruptured membranes. Furthermore, MW irradiation changed the distribution of airborne endotoxins, sharply decreased the concentration of bound endotoxins from 230 EU/m3 to 68 EU/m3, and increased the concentration of free endotoxins from 21 EU/m3 to 122 EU/m3. These results indicated that MW irradiation released endotoxins from cells into the atmosphere. MW irradiation likely degraded endotoxins by exerting thermal effects, which achieved a total endotoxin removal efficiency of as high as 35%. Endotoxin degradation was a first-order reaction and required the activation energy of 26.3 kJ/mol.

[Efficacy of staging surgery in pulmonary atresia with intact ventricular septum]

Objective: To assess the feasibility and efficacy of a staged invasive treatment strategy for the treatment of pulmonary atresia with intact ventricular septum, in the first stage using a catheter-based stent placement, second-stage surgery, and three-stage atrial septal occlusion. Methods: Totally 19 children with pulmonary atresia with intact ventricular septum were enrolled at Department of Cardiovascular Surgery, the Children's Hospital of Zhejiang University School of Medicine from January 2009 to December 2017, including 11 male and 8 female patients. The age was (13.8±7.7) days (ranging from 3 to 35 days). The weight was (3.4±0.5) kg (ranging from 2.8 to 4.1 kg). Among them, there were 13 cases of type Ⅱ and 6 cases of type Ⅲ. Regular follow-up visits for patients with stage Ⅰ arterial duct stenting after 1, 3, and 6 months; and routine follow-ups for 1, 3, and 6 months after stage Ⅱ surgery.The t test was used to compare the oxygen saturation between pre-operation and post-operation. Results: All 19 patients underwent arterial catheterization. The preoperative peripheral oxygen saturation was (64.4±5.3)%, while increased to (86.0±3.0)% after operation (t=16.353, P=0.000). One patient died during follow-up and 2 patients lost follow-up. One patient received stent balloon dilatation due to oxygen saturation decrease.Twelve patients completed the second-stage surgery and 1 case died after surgery. The rest were alive, including 2 cases of double-ventricular correction and 9 cases of semi-ventricular treatment in one room; 2 cases had completed three-stage atrial septal occlusion. Conclusions: Stage Ⅰ arterial duct stent, stage Ⅱ surgery, and stage Ⅲ atrial septal occlusion to treat pulmonary atresia with intact ventricular septum in children is feasible and effective. The method can be used as the important treatment direction for pulmonary atresia with intact ventricular septum.

[Forensic Pathological Examination on 73 Medical Malpractice Cases of Pediatrics]

OBJECTIVES

To analyse 73 medical malpractice cases of pediatrics for discussing the importance of forensic pathology in solving the issues such as medical malpractice of pediatrics.

METHODS

From January 2002 to August 2016, 73 medical malpractice cases of pediatrics with age of death between 28 days old and 10 years old were collected from Institute of Judical Expertise of Nanjing Medical University. The relationship between causes of death and related medical institutions was retrospectively analysed.

RESULTS

In 73 cases, the male to female ratio was 1.70∶1, and ages of 28 days old to 1 year old were common （26 cases, 35.62%）, followed by ages between 1 year old and 3 years old （21 cases, 28.77%）. In 71 cases which had been determined the cause of death by postmortem examination, the main cause of death was disease, especially respiratory diseases （33 cases, 46.48%）, followed by cardiovascular diseases （12 cases, 16.90%）. In 75 medical institutes which involved with these medical malpractices, most were tertiary medical institutes （32, 42.67%）, followed by the sub-secondary （excluding the secondary） medical institutions （23, 30.67%）. The clinical diagnosis of 38 cases （52.05%） completely or mostly corresponded with the pathological findings. There were 35 cases （47.95%） undefined or misdiagnosed cases.

CONCLUSIONS

Autopsy and forensic pathological examination contribute to determine causes of death, which not only provide scientific evidence for medical malpractice of pediatrics, but also enrich and develop clinical medical knowledge, and thus improve diagnosis and treatment level in a certain extent.

Vector Form of Symmetry Degree

Symmetry degree is utilized to characterize the asymmetry of a physical system with respect to a symmetry group. The scalar form of symmetry degree (SSD) based on Frobenius-norm has been introduced recently to present a quantitative description of symmetry. Here we present the vector form of the symmetry degree (VSD) which possesses more advantages than the SSD. Mathematically, the dimension of VSD is defined as the conjugacy class number of the symmetry group, the square length of the VSD gives rise to the SSD and the direction of VSD is determined by the orders of the conjugacy classes. The merits of applying VSD both for finite and infinite symmetry groups include the additional information of broken symmetry operators with single symmetry breaking perturbation, and the capability of distinguishing distinct symmetry breaking perturbations which exactly give rise to degenerate SSD. Additionally, the VSD for physical systems under symmetry breaking perturbations can be regarded as a projection of the initial VSD without any symmetry breaking perturbations, which can be described by an evolution equation. There are the same advantages by applying VSD for the accidental degeneracy and spontaneous symmetry breaking.