Objective:To investigate mucosal injury after high-dose methotrexate (HD-MTX) chemotherapy in treatment of children with acute lymphoblastic leukemia (ALL), and to analyze the association with methotrexate blood concentration, risk stratification and clinical efficacy.Methods:The data of 95 children with ALL who received 539 times of HD-MTX chemotherapy in the First Hospital of Harbin from November 2015 to October 2018 were retrospectively analyzed, and the association of mucosal injury with methotrexate blood concentration, disease risk degree and clinical efficacy was also analyzed.Results:Among 95 children who received 539 times of HD-MTX chemotherapy, the total incidence of mucosal injury was 8.4% (45/539); the incidence of mucosal injury was 4.6% (11/239), 7.6% (8/105), 13.3% (26/195), respectively in the low-risk group, middle-risk group and high-risk group. With the elevation of disease risk, the incidence of mucosal injury was increased ( χ2 = 10.787, P < 0.05). There was no correlation of the degree of mucosal injury with methotrexate blood concentration and disease risk degree (all P > 0.05), and the mucosal injury was not related with the clinical efficacy ( P > 0.05). Conclusion:After the application of HD-MTX in children with ALL, adjustment of the dose of rescue drug by monitoring of methotrexate blood concentration can improve the safety of therapeutic drugs.

Objective:To explore the therapeutic effect of low-dose arsenous acid/tretinoin with or without low-dose cytarabine induction regimen on myelodysplastic syndromes (MDS) with TET2 gene mutation in children.Methods:Nine children with MDS who were hospitalized at the First Hospital of Harbin from March 2009 to April 2018 were collected, including 3 cases of refractory cytopenia of childhood (RCC), 4 cases of MDS with excess of blasts type Ⅰ (MDS-EBⅠ) and 2 cases of MDS with excess of blasts type Ⅱ (MDS-EBⅡ). The next-generation gene sequencing method (NGS) was applied to detect the TET2 gene mutation in bone marrow cells of children with MDS. The low-dose arsenous acid/tretinoin with or without low-dose cytarabine induction regimen was adopted to conduct tiered therapy on children with MDS. The clinical efficacy was assessed in line with the MDS response evaluation criteria adopted by the MDS International Working Group (IWG) in 2006.Results:Among the 9 patients, the short-term clinical efficacy was observed in 8 cases. Two patients with TET2 gene mutation achieved the short-term clinical efficacy of bone marrow complete remission (mCR) and hematological improvement (HI). Among 7 patients without TET2 gene mutation, 4 patients obtained CR, 1 patients obtained mCR and HI, and 1 patients obtained stable disease (SD) in terms of the short-term clinical efficacy.Conclusion:The low-dose arsenous acid/tretinoin with or without low-dose cytarabine regimen may be beneficial to MDS children with TET2 gene mutation.

Dengue viruses(DENV) are seriously affected by cell autophagy in intracellular replication,transmission between host,and the pathogenic mechanism.Here,the latest research progress of complex interplay between DENV and cell autophagy were reviewed in this paper.Autophagy,a cellular procedural protein degradation pathway generally possessed by all eukaryotes plays a key role in response to outside pressure and maintaining cellular homeostasis.This catabolic pathway also promotes cell survival against the invasion of pathogens such as various viruses.However,autophagy plays an opposite role in the replication of DENV.Autophagy not only provides a replication site for viruses to replicate,but also provides a source of energy for this process.Cell autophagy also participates in the pathogenesis of some DENV infection.In short,autophagy contributes to the replication of DENV.

Objective: To explore the spatial-temporal distribution and epidemic characteristics of hemorrhagic fever with renal syndrome (HFRS) in Hebei province from 2005 to 2016. Methods: Records of HFRS cases reported from each county in Hebei during January 2005 to December 2016 were collected from National Notifiable Disease Surveillance System (NNDSS). Global and local spatial association statistics were used to measure the spatial autocorrelation and software GeoDa 1.2.0. Software SaTScan 9.4.1 was used to analyze spatiotemporal clusters. Software ArcGIS 10.2 was used to visualize the yearly scan results. Results: In Hebei province, a total of 8 437 human HFRS cases reported from 170 counties with an annual incidence rate of 0.99/100 000 population during 2005-2016. The peak incidence season was spring. Global spatial autocorrelation analysis on the incidence of HFRS at county-level showed that the value of Moran’s I were all above 0 (P<0.05), indicating that the significant spatial cluster. The result of local indicators on spatial association (LISA) analysis revealed that identified hot spots were mainly in northeastern area, while cold spots were found in some counties of central and southern areas. Spatial-temporal scan detected that the primary cluster of HFRS incidence was mainly distributed in Qinhuangdao city and Tangshan city, including 11 counties (city/district): Beidaihe district, Haigang district, Funing district, Shanhaiguan district, Changli county, Lulong county and Qinglong Manchu autonomous county in Qinhuangdao city, and Qian’an city, Laoting county, Luanzhou city and Luannan county in Tangshan city (RR=39.64, P<0.001), during January-July in 2005. Conclusions There were significant spatial-temporal cluster of HFRS in Hebei from 2005 to 2016. The cluster areas of HFRS were mainly in northeastern Hebei, it is necessary to strengthen the prevention and control programs of HFRS in these areas.

Objective: To evaluate the efficacy and safety of drug-coated balloons (DCB) for de novo large coronary vessels. Methods: One hundred and two patients were retrospectively enrolled in this study, there were 104 lesions with the reference lumen diameter of target vessel more than 2.8 mm and patients were treated with DCB in de novo lesions during May 2015 and July 2017 in our center. Coronary artery angiography and quantitative coronary angiography were performed in 82 (80.4%) patients at follow up period ((8.1±1.7) months post procedure). The endpoints were late lumen loss (LLL) at follow up,and major adverse cardiac events (MACE) including cardiac death, myocardial infarction (MI), target lesion revascularization (TLR) and stent or target lesion thrombosis at 12 months post procedure. Results: Ninety-eight lesions were treated with DCB only, 6 (5.9%) bailout drug-eluting stent (DES) were used because of severe coronary dissection, 2 patients (2.0%) received revascularization driven by acute ischemic events during hospitalization. Cutting balloons and NSE balloons were used in 65.4% (68/104) and 26.0% (27/104) lesions. The lesion length was (12.57±3.58) mm and the DCB length was (19.87±4.55) mm. The late lumen loss was (0.01±0.52) mm during angiographic follow up. The TLR rate and overall MACE rate was 3.9% (4/102) and 3.9% (4/102) and there was no death,MI and target lesion thrombosis at 12 months follow up. Conclusion DCB treatment for de novo large coronary vessels is effective and safe.

Objective To ohserve the effect of individualized exercise programs on the activity tolerance and life quality of heart failure patients with a preserved ejection fraction.Methods Heart failure patients with a preserved left ventricular ejection fraction (LVEF) were randomized to an exercise training group (n=55) or a control group (n =53).Both groups were given optimized heart failure drug therapy,while the exercise training group was additionally provided with individualized exercise training.The LVEFs,6-minute walking distances (6MWDs),Minnesota living with heart failure questionnaire (MLHFQ) scores and adverse events were noted before the experiment and after 12 months of the intervention.Results After one year,no significant differences were found in the groups' average LVEFs or in the ineidence of adverse events,while the average 6MWD and the average MLHFQ score of the exercise training group were significantly better than those of the control group.The average MLHFQ seore decrease (7.8 points) was statistically and practically significant.Conclusion Individualized exercise training can significantly improve the activity tolerance and quality of life of patients with a preserved ejection fraction.It is safe,but the impacts on the ejection fraction are small.

Objective To assess the influence of metabolic syndrome(MS)on the success rate of catheter ablation for the treatment of atrial fibrillation (AF)in the elderly. Methods A retrospective study included a total of 221 aged patients with AF who underwent AF ablation for the first time. The patients were divided into two groups :an MS group(n＝72)and a control group(without MS)(n＝149) . The MS group had a mean age of (67.1 ± 5.2) years ;the control group had a mean age of (68.3 ± 5.7) years. Forty-six patients in the MS group and 105 patients in the control group experienced paroxysmal atrial fibrillation. Prognoses in two groups were compared at the end of the follow-up. Results At the end of the follow-up ,the success rates of the procedure in the MS group and the control group were 37.5%(n ＝ 27)and 51.7%(n ＝ 77) ,respectively (χ2＝ 3.917 ,P ＝ 0.049) .Recurrence happened in 19 patients of the MS group and 28 patients of the control group ,and they underwent a repeat ablation. The overall success rates after the last ablation in the two groups were 51.4%(n＝37)and 65.8%(n＝98) ,respectively (χ2＝4.224 ,P＝0.034).In the multivariable model adjusted for risk factors ,MS(HR＝1.42 ,95% CI :1.11-1.64 ,P＝0.033)and left atrial diameter(HR＝ 1.83 ,95% CI :1.27-3.19 , P ＝ 0.017 ) were independent predictors for recurrence. Conclusions MS can affect the success rate of catheter ablation for AF in elderly patients and the effect remains even after the procedures are repeated

Objective: To evaluate the efficacy and safety of three-dimensional electroanatomical mapping system for catheter ablation of paroxysmal supraventricular tachycardiain (PSVT) children. Methods: Clinical data from 187 children with paroxysmal supraventricular tachycardia undergoing radiofrequency catheter ablation in our department between January 2012 and April 2016 were analyzed. Among the patients, 91 cases were treated with traditional two-dimensional X-ray radiofrequency ablation, 96 cases were treated with radiofrequency ablation guided by three-dimensional electroanatomical mapping system. Postoperative electrocardiogram and echocardiography follow-up was performed at 1, 3, 6, 12, and 24 months. The success rate, recurrence rate, complication rate, operation time and amount of X-ray exposure were compared between the two groups. Kaplan-Meier survival curve was used to analyze the PSVT-free survival rate of the patients between the 2 groups. Results: The mean follow-up time was (739±92) days. The success rate (95.8%(92/96) vs. 94.5%(86/91), P=0.912), recurrence rate (5.4%(5/92) vs. 4.7%(4/86), P=0.807), complication rate (4.2%(4/96) vs. 5.5%(5/91), P=0.379), operation time ((73±31)min vs. (79±36)min, P=0.124) were similar between the two groups. However, X-ray exposure time ((8.1±2.9)min vs. (21.3±8.4)min, P=0.026), amount of X-ray ((23±11)mGy vs. (58±23)mGy, P=0.013) were significantly lower in the three-dimensional electroanatomical mapping system group than in the traditional two-dimensional X-ray radio frequency ablation group. PSVT-free survival rate was similar between the two groups (χ²=0.060, P=0.807) . Conclusion Three-dimensional electroanatomical mapping system is safe and effective for radiofrequency ablation of paroxysmal supraventricular tachycardia in children, and can significantly reduce the amount of radiation as compared to the traditional two-dimensional X-ray radiofrequency ablation.

Objective To investigate the effect of thyroxine replacement therapy with residual subclinical hypothyroidism on the success rate of catheter ablation in elderly patients with atrial fibrillation(AF).Methods Among the consecutive patients with AF who underwent a first AF ablation in our center between 2009 and 2012,we identified 56 patients(41 paroxysmal AF,15 persistent AF)with subclinical clinical hypothyroidism after receiving thyroid hormone replacement therapy as study group.The control group consisted of 56 patients with euthyroidism and no history of thyroid dysfunction.All patients underwent catheter ablation.Results At the end of follow up,37.5%(21/56)patients were AF free after the first procedure in the study group,in comparison to 64.3%(36/56)in control group(χ2=8.655,P=0.003).Last procedure was performed in 27 patients of study group and in 15 patients of control group.After the last performed ablation,62.5%(35/56)study group patients and 80.4%(45/56)controls group patients had no recurrence(χ2=4.653,P=0.031).The major complications rate did not differ between two groups(P=0.642).Conclusions Thyroid hormone replacement therapy with residual subclinical hypothyroidism reduces catheter ablation success rate in elderly patients with atrial fibrillation.

Objective To establish a fluorescent antibody virus neutralization (FAVN) test for hantavirus (HV).Methods With the method of dilution serum and fixed virus,the serum samples were diluted with different concentration,and with virus-liquid were mixed in 96 culture plate hole,37 ℃ for 1 hour.Then the mixture of serum and virus was added to Veto-E6 cells which had grown into a monolayer,and cultivated in the 37 ℃,5％ CO2 incubator for 7 days; the 96-well plate was fixed and stained.The results were observed under a fluorescence microscope.The neutralization titer was calculated according to the formula.Results The suitable cell concentrations is 4 × 104 ～ 4.5 × 104/hole,and the proper temperature for neutralize is 37 ℃.30 serum specimens of HFRS were tested by FAVN and PRNT,the FAVN is more sensitive and stable.Conclusion FAVN is easier,faster and more sensitive than the others.