[Metagenomic next-generation sequencing-based retrospective investigation of the drug resistance sites of Mycoplasma pneumoniae in children]

Objective: To analyze the drug-resistant gene loci of Mycoplasma pneumoniae (MP) using metagenomic next-generation sequencing (mNGS). Methods: From November 2022 to October 2023, 697 clinical samples (including sputum, alveolar lavage fluid and blood) of 686 children with Mycoplasma pneumoniae positive detected by mNGS were retrospectively analyzed. Samples were divided into intensive care unit (ICU) group and non-ICU group, Chi-square test was used to compare groups, and Mann-Kendall trend test was used to analyze the change trend of the detection rate of drug resistance gene loci over time. Results: Of the 697 samples, 164 were from the ICU group and 533 were from the non-ICU group. The detection rate of Mycoplasma pneumoniae resistance gene was 44.3% (309/697), and all detected drug-resistant gene loci of MP were A2063G. The detection rate of Mycoplasma pneumoniae in ICU group was 50.0% (82/164), and the detection rates of Mycoplasma pneumoniae resistance gene loci in sputum, alveolus lavage fluid and blood samples were 75.0% (18/24) and 48.4% (62/128), respectively. The detection rate in sputum was higher than alveolus lavage fluid samples (χ2=5.72,P=0.017). The detection rate of Mycoplasma pneumoniae in non-ICU group was 42.6% (227/533), the detection rate of Mycoplasma pneumoniae resistance gene loci in sputum and alveolar lavage fluid was 40.0% (16/40), 44.3% (201/454), and no detection rate in blood samples (0/12). There was no significant difference in the detection rate of alveolar lavage fluid and sputum (χ2=0.27, P=0.602). From November 2022 to October 2023, the detection rate of submitted samples showed an increasing trend month by month (overall: Z=3.99, ICU inspection group: Z=2.93, non-ICU group: Z=3.01, all P<0.01). Among the bacteria commonly detected with Mycoplasma pneumoniae, Streptococcus pneumoniae accounted for the highest proportion, the detection rate was 15.5% (108/697), and Epstein-Barr virus accounted for the highest proportion of 17.6% (123/697). Conclusions: From November 2022 to October 2023, the detection rate of Mycoplasma pneumoniae drug resistance gene loci showed an increasing trend. The detection rate of drug resistance gene loci in sputum samples of ICU group was higher than alveolus lavage fluid. No new drug resistance site were detected.

Frontostriatal circuit dysfunction leads to cognitive inflexibility in neuroligin-3 R451C knockin mice

Cognitive and behavioral rigidity are observed in various psychiatric diseases, including in autism spectrum disorder (ASD). However, the underlying mechanism remains to be elucidated. In this study, we found that neuroligin-3 (NL3) R451C knockin mouse model of autism (KI mice) exhibited deficits in behavioral flexibility in choice selection tasks. Single-unit recording of medium spiny neuron (MSN) activity in the nucleus accumbens (NAc) revealed altered encoding of decision-related cue and impaired updating of choice anticipation in KI mice. Additionally, fiber photometry demonstrated significant disruption in dynamic mesolimbic dopamine (DA) signaling for reward prediction errors (RPEs), along with reduced activity in medial prefrontal cortex (mPFC) neurons projecting to the NAc in KI mice. Interestingly, NL3 re-expression in the mPFC, but not in the NAc, rescued the deficit of flexible behaviors and simultaneously restored NAc-MSN encoding, DA dynamics, and mPFC-NAc output in KI mice. Taken together, this study reveals the frontostriatal circuit dysfunction underlying cognitive inflexibility and establishes a critical role of the mPFC NL3 deficiency in this deficit in KI mice. Therefore, these findings provide new insights into the mechanisms of cognitive and behavioral inflexibility and potential intervention strategies.

[Source Analysis and Health Risk Assessment of PAHs in PM2.5, Lüliang City]

To investigate the seasonal variation, health risks, and potential sources of polycyclic aromatic hydrocarbons(PAHs) in PM2.5 in the Lüliang area, PM2.5 samples were collected in Lishi District(downtown area) and Xiaoyi City(suburban area) from October 23, 2018 to July 1, 2019, and the concentrations of 14 PAHs were determined using gas chromatography-mass spectrometry(GC-MS). The annual average concentration of PAHs was 95.50 ng·m-3, and the concentration of 5-6 ring PAHs was mainly(49.7%), with 3 ring PAHs accounting for a relatively low proportion(8.3%).The concentration of PAHs in Lüliang City showed a seasonal pattern of winter>autumn>spring>summer. The results of the ILCRs model and Monte Carlo simulation showed that the toxicity of PAHs in Lüliang City followed the rule of adults>youth>children. Except in summer, the ILCRs values in the Lishi area were between 10-6 and 10-4, much higher than those in Xiaoyi City, indicating that there was a high potential risk of polycyclic aromatic hydrocarbons in the urban area. Through the characteristic ratio method and positive matrix factorization(PMF), it was shown that the PAHs in Lüliang City were mainly from the combustion of coal and biomass(61.9%) and vehicle exhaust emissions(38.1%). Based on the backward trajectory and potential source factor contribution analysis model, it was determined that the potential sources of PAHs in Lüliang City were mainly distributed in southern Shanxi, northern Shaanxi, and western Inner Mongolia.

Targeted VEGFA therapy in regulating early acute kidney injury and late fibrosis

Damage to peritubular capillaries is a key process that contributes to acute kidney injury (AKI) progression. Vascular endothelial growth factor A (VEGFA) plays a critical role in maintaining the renal microvasculature. However, the physiological role of VEGFA in various AKI durations remains unclear. A severe unilateral ischemia‒reperfusion injury model was established to provide an overview of VEGFA expression and the peritubular microvascular density from acute to chronic injury in mouse kidneys. Therapeutic strategies involving early VEGFA supplementation protecting against acute injury and late anti-VEGFA treatment for fibrosis alleviation were analyzed. A proteomic analysis was conducted to determine the potential mechanism of renal fibrosis alleviation by anti-VEGFA. The results showed that two peaks of extraglomerular VEGFA expression were observed during AKI progression: one occurred at the early phase of AKI, and the other occurred during the transition to chronic kidney disease (CKD). Capillary rarefaction progressed despite the high expression of VEGFA at the CKD stage, and VEGFA was associated with interstitial fibrosis. Early VEGFA supplementation protected against renal injury by preserving microvessel structures and counteracting secondary tubular hypoxic insults, whereas late anti-VEGFA treatment attenuated renal fibrosis progression. The proteomic analysis highlighted an array of biological processes related to fibrosis alleviation by anti-VEGFA, which included regulation of supramolecular fiber organization, cell-matrix adhesion, fibroblast migration, and vasculogenesis. These findings establish the landscape of VEGFA expression and its dual roles during AKI progression, which provides the possibility for the orderly regulation of VEGFA to alleviate early acute injury and late fibrosis.

[Survey of Helicobacter pylori levofloxacin and clarithromycin resistance rates and drug resistance genes in Ningxia, 2020-2022]

Objective: To explore the rate of Helicobacter pylori (Hp) resistance to levofloxacin and clarithromycin and the common mutation patterns of resistance genes in Ningxia, and to assess the concordance between phenotypic resistance and genotypic resistance. Methods: Cross-sectional study. Patients diagnosed with Hp infection in 14 hospitals in Ningxia region from February 2020 to May 2022 were retrospectively selected. Hp strains were isolated from gastric biopsy specimens of Hp-infected patients and subjected to phenotypic drug sensitivity testing and detection of resistance genes to analyze the rate of Hp resistance to levofloxacin and clarithromycin and the common mutation patterns of resistance genes in Ningxia region; and the concordance rate and Kappa concordance test were used to assess the concordance between phenotypic resistance and genotypic resistance. Results: A total of 1 942 Hp strains were isolated and cultured, and among the infections, 1 069 cases (55.0%) were male and 873 cases (45.0%) were female, aged (50.0±12.5) years (15-86 years). The rates of Hp resistance to levofloxacin and clarithromycin in Ningxia were 42.1% (818/1 942) and 40.1% (779/1 942), respectively, and the rate of dual resistance to both was 22.8% (443/1 942). The rate of resistance to levofloxacin and clarithromycin of Hp strains from female patients was higher than in male patients (levofloxacin: 50.4%(440/873) vs 35.4%(378/1 069); clarithromycin: 44.4%(388/873) vs 36.6%(391/1 069), both P<0.001). Among the GyrA gene mutations associated with levofloxacin resistance, the differences in mutation rate of amino acid at positions 87 and 91 were statistically significant in both drug-resistant and sensitive strains(both P<0.001), except for Asn87Thr. Hp strains were statistically significant for levofloxacin (Kappa=0.834, P<0.001) and clarithromycin (Kappa=0.829, P<0.001) had good concordance in resistance at the phenotypic and genotypic levels. Conclusion: The resistance of Hp to levofloxacin and clarithromycin in Ningxia region is severe, and there is good consistency between genotypic and phenotypic resistance.

A novel nomogram for predicting overall survival in peripheral T cell lymphoma patients.. [DOI: 10.21203/rs.3.rs-2823604/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0]

Background The prognosis of peripheral T cell lymphomas (PTCLs) varies greatly. This study aimed at generating a prognostic nomogram based on differentially expressed genes (DEGs).Methods Firstly, we collected RNA transcripts from Gene Expression Omnibus and identified DEGs. Secondly we used univariate Cox regression, Least absolute shrinkage and selection operator (LASSO) to screen the independent risk factors to construct nomogram in the training cohort. Thirdly, we evaluate its prediction accuracy via decision curves analysis (DCA), receiver operating characteristic (ROC) and calibration rate to confirm its performance on survival in training and validation cohort. Then we carried out subgroup analysis in training and validation to eliminate the effects of age, gender, and pathological subtype. Lastly, to verify feasibility of nomogram in practice, we applied immunohistochemistry to clinical samples and analyzed the relationship between IHC scores and prognosis.Results The 702 DEGs between 40 PTCLs and 20 non-tumor patients were identified. Then ANGPTL2, CPSF4, CLIC4 and OTUD6B were screened out as independent risk factors via univariate Cox regression and LASSO. The DCA, ROC, Harrell’s concordance index (c-index) and calibration rate showed nomogram predicting more accurately than any single specific transcript. The results showed PTCLs with higher nomogram-score had a longer survival, regardless of age, gender and pathological subtype. Finally, the high expression level of ANGPTL2, CPSF4 and OTUD6B related to poor prognosis. Higher expression of CLIC4 related to longer survival.Conclusion This nomogram showed the favorable clinical applicability, regardless of age, gender and pathological subtype.

[Preliminary analysis of pulse-step-sine test results in healthy population]

Objective: To analyze the characteristics of pulse-step-sine (PSS) test in healthy people of different ages and to discuss its clinical value. Methods: From July 10, 2018 to December 9, 2020, a total of 78 healthy volunteers, including 40 males and 38 females, were enrolled and divided into youth group, middle age group and old age group. The I Portal NOTC rotational-chair system (NKI) was applied for PSS detection to analyze the clinical characteristics of gain, phase, asymmetry, and slope of step and sinusoidal components. Statistical analysis was performed using SPSS17.0 software. Results: In the same age group, there were no statistically significant differences in left and right step gain, slope gain and sine gain (All P values were greater than 0.05). Pairwise comparison between different age groups showed that there was no significant difference in the corresponding parameters between the youth group and the middle age group. Compared with young group, the old age group had a significantly lower step gain value in their left side (P<0.01) but not in the right side (P>0.05).The left and right slopes of the old age group were significantly lower than those of the young group and the middle group, and the differences were statistically significant (All P values<0.05). Conclusion: The PSS test can detect bilateral and unilateral horizontal semicircular canal function with good tolerance in different age groups, better than the traditional rotational chair examination to determine the well-compensated unilateral vestibular function. PSS test is a new vestibular detection method.

[Etiology and epidemiology of hand, foot and mouth disease in China]

Hand, foot and mouth disease (HFMD) has been widespread in the world, and caused fever, rashes and other clinical symptoms of children, and sometimes inducing respiratory failure, brainstem encephalitis, and other complications, even death. The disease is mainly caused by enterovirus 71 (EV-A71) and coxsackievirus 16 (CV-A16). Since 2013, the proportion of HFMD cases caused by other enteroriruses has gradually increased, causing severe and even fatal cases. This paper summarizes the research progress in the epidemiological and etiological characteristics of HFMD in China since 2008.

[Correlation analysis of 3D-FLAIR MRI characteristics of the inner ear and vestibular function in the patients with vestibular neuritis]

Objective: The characteristics of 3D-FLAIR MRI images of the inner ear of patients with vestibular neuritis were preliminarily studied to explore the possible pathogenesis of vestibular neuritis, and the correlation analysis was conducted in combination with vestibular function to provide a basis for accurate diagnosis of vestibular neuritis. Methods: A total of 36 patients with vestibular neuritis (VN) from December 2019 to October 2020 were collected from the Vertigo Department of Shandong Provincial ENT Hospital, Cheeloo College of Medicine, Shandong University. There were 36 cases (18 females, 18 males) with unilateral acute vestibular neuritis, 17 cases of left ear and 19 cases of right ear. According to the results of 3D-FLAIR MRI in the inner ears, the patients were divided into the enhanced group and the non-enhanced group (the health side served as the normal control group). The results of vestibular function examination in the two groups were compared. SPSS19.0 software was used for statistical processing to analyze the relationship between the vestibular function and the characteristics of 3D-FLAIR imaging in the inner ears. Results: Abnormal enhancement of 3D-FLAIR was found in 31 cases (86.1%) of the 36 cases, including 14 cases of both vestibular nerve and vestibular terminal organ enhancement, eight cases of superior vestibular nerve enhancement alone, seven cases of vestibular terminal organ enhancement alone, and two cases of cochlear enhancement alone. Observation of abnormal reinforcement of vestibular nerve showed: twenty-one cases of superior vestibular nerve reinforcement, one case of superior and inferior vestibular nerve reinforcement. No abnormalities were found in 3D-FLAIR of inner ear in 5 cases. According to the analysis of vestibular function results, there were 19 cases (52.8%) with total vestibular involvement, sixteen cases (44.4%) with superior vestibular involvement alone, and one case (2.8%) with inferior vestibular involvement alone. Comparison of vestibular function between the five cases (non-enhancement group) and the 31 cases (enhanced group) in the 3D-FLAIR group of the inner ears showed that the CP values of caloric tests in the enhanced group were higher (60.81±3.49 vs 34.12±7.37), with statistically significant difference (t=-2.898, P<0.01). Conclusion: In patients with vestibular neuritis, 3D-FLAIR MRI scan of the inner ear provides visual imaging evidence for clinical practice, considering that the lesion site of vestibular neuritis is not only in the vestibular nerve, but also in the vestibular end organ. Patients with 3D-FLAIR enhanced in the inner ear may have more significant vestibular function damage.

Polarized proton acceleration in ultraintense laser interaction with near-critical-density plasmas

The production of polarized proton beams with multi-GeV energies in ultraintense laser interaction with targets is studied with three-dimensional particle-in-cell simulations. A near-critical density plasma target with prepolarized proton and tritium ions is considered for the proton acceleration. The prepolarized protons are initially accelerated by laser radiation pressure before injection and further acceleration in a bubblelike wakefield. The temporal dynamics of proton polarization is tracked via the Thomas-Bargmann-Michel-Telegdi equation and it is found that the proton polarization state can be altered by both the laser field and the magnetic component of the wakefield. The dependence of the proton acceleration and polarization on the ratio of the ion species is determined and it is found that the protons can be efficiently accelerated as long as their relative fraction is less than 20%, in which case the bubble size is large enough for the protons to obtain sufficient energy to overcome the bubble injection threshold.

[Immunomicroecology: concept and applications]

Microorganism exerts a profound impact on the development and function of human immunity. Vice versa, immunity also affects the constitution and function of human microbiota. Hence, a new concept, immunomicroecology, has been put forward as an inevitable consequence of the development in the fields of microecology and immunology. Here, we describe the reciprocities between immunological system and microecological system, and elaborate the concept, developing course, and prospects of immunomicroecology.

A resonance suppression method in platform style inertial reference unit via particle swarm optimization notch filter

With the development of laser communication, remote sensing imaging, and other technologies, an inertial reference unit (IRU) plays an essential part in the line-of-sight (LOS) stabilization system used for acquiring, pointing, and tracking targets. The IRU provides a stable reference beam to realize accurate LOS pointing under external disturbances. Compared with the frame style IRU, the platform style IRU (PIRU) can achieve a higher bandwidth and better precision. However, mechanical resonance is introduced by a flexure hinge inevitably in the PIRU, which affects the performance of the LOS stabilization system. In this paper, an open-loop dynamic model of PIRU is established. Identification experiments are carried out with results indicating a 28.7 dB resonance peak at 27.07 Hz in the x axis and a 30.3 dB resonance peak at 26.59 Hz in the y axis. An asymmetric notch filter is used to suppress the resonance peak to achieve a higher control bandwidth. A fitness function is designed to represent the effect of resonance suppression. A particle swarm optimization algorithm is used to search for an optimal solution of the fitness function to obtain the parameters of the asymmetric notch filter. Experimental results show that the resonance peak is reduced by 97.88% and the system bandwidth reaches 159.31 Hz.

Propofol inhibited gastric cancer proliferation via the hsa-miR-328-3p/STAT3 pathway

PURPOSE

The aim of the present study was to elucidate the functional role of hsa-miR-328-3p/STAT3 pathway in the effects of propofol on gastric cancer proliferation.

METHODS

Bioinformatics was used to analyze the molecular expression differences of hsa-miR-328-3p/STAT3 axis in stomach adenocarcinoma (n = 435) and normal samples (n = 41) from TCGA database. The expression of the above molecules in gastric cancer cells SGC-7901 and normal gastric mucosal cells GES-1 was verified via qPCR. The dual-luciferase assay was carried out to confirm the interaction between hsa-miR-328-3p and STAT3. Subsequently, the cell proliferation and the expression of the above molecules in SGC-7901 and GES-1 cells were evaluated after 10 μM propofol treatment. Finally, we analyzed whether propofol still inhibited the proliferation of gastric cancer by suppressing STAT3 pathway after hsa-miR-328-3p down-regulation.

RESULTS

Compared with normal samples, the expression of hsa-miR-328-3p was significantly down-regulated in stomach adenocarcinoma samples, while the expression of STAT3 and downstream target genes (MMP2, CCND1 and COX2) was up-regulated. The results were consistent with those in GES-1 and SGC-7901 cell lines. Meanwhile, we found that hsa-miR-328-3p can bind to the 3'-UTR of the potential target gene STAT3. Furthermore, propofol significantly inhibited the proliferation of gastric cancer cell line SGC-7901, where hsa-miR-328-3p was up-regulated and the expression of STAT3 and downstream proliferation-related target genes were down-regulated. However, the growth inhibition of propofol on SGC-7901 cell was significantly reversed after the inhibition of hsa-miR-328-3p.

CONCLUSIONS

To sum up, propofol suppressed the STAT3 pathway via up-regulating hsa-miR-328-3p to inhibit gastric cancer proliferation.

[The roles of two HIV self-testing models in promoting HIV-testing among men who have sex with men]

Objective: To evaluate the roles between two different HIV self-testing models in promoting HIV-testing among men who have sex with men (MSM). Methods: This paper focuses on two HIV self-testing service models. The first; is the online self-testing model (HIV self-testing conventional model) with the sexual health promotion network platform. The other one is an innovative HIV self-testing model (secondary distribution model), based on the previous program. The two different self-testing models, including the number of indexes and alters, the positive rate, and the demographics of indexes and alters, are compared. The influence of volunteers with or without leadership on the number of HIV self-test kits distributed or self-use is analyzed through the leadership survey scale. Results: The return rates of HIV self-testing results in the two models are 94.7%(323/341) and 99.2%(1 141/1 150), respectively, within 30 days. The proportion of alters in the secondary distribution is significantly higher (45.9%,281/612) than the conventional HIV self-testing (6.3%,20/318). In the secondary distribution model, the difference between the number of indexes and alters indicators including age, marital status, residence, sex orientation, anal sex with men in the past six months, and HIV test are statistically significant (χ² test, all P<0.05). The opinion leader of MSM has significantly impacted the promotion of HIV self-testing (P<0.05). Conclusions: Both models can promote HIV self-testing, result return, and HIV positive detection among MSM. In terms of expanding the testing and detection of HIV positive, the secondary distribution mode shows more obvious advantages, which significantly promotes a large number of MSM who have never been tested for HIV to undergo HIV testing. Influential indexes have a significant effect on increasing the HIV testing rate and promoting HIV testing among MSM.

Removable retropubic uterine compression suture for controlling postpartum hemorrhage

OBJECTIVE

To minimize the adverse events of uterine compression suture in controlling postpartum hemorrhage (PPH) and to search for a prophylactic approach to potential PPH.

METHODS

A retrospective analysis was performed in 39 women with removable retropubic uterine compression suture (RRUCS) to stop PPH due to uterine atony during cesarean section (CS). The procedure was to suspend and compress the uterus to the retropubic abdominal wall using an absorbable suture.

RESULTS

The technique was sufficient to stanch bleeding immediately in 36 patients (92.31%, 36/39). No morbidity or abnormalities occurred in women who underwent RRUCS. Subsequent pregnancies occurred in 10 cases, but the others lacked the desire for future pregnancy.

CONCLUSION

RRUCS is a simple, safe, and effective technique in controlling atonic PPH; it is also used as a prophylactic application in patients with potential PPH after CS.

The Impacts of Urban Manufacturing Agglomeration on the Quality of Water Ecological Environment Downstream of the Three Gorges Dam

As an important way to promote economic growth and to improve ecological environment quality, industrial agglomeration strategy has been widely accepted and implemented in various regions of China. In theory, industrial agglomeration is conducive to reducing pollution emissions. However, this needs to be tested in reality. The purpose of this paper is to test the impacts of manufacturing industry agglomeration on the quality of water ecological environment in 17 prefecture-level cities downstream of the Three Gorges Dam. Therefore, a theoretical model was established to test the direct and indirect effects. Empirically, results show that the direct effect of manufacturing agglomeration on the quality of water ecological environment is −0.426, which provides statistical evidence for the important role of manufacturing agglomeration in improving the quality of water ecological environment. The indirect effect of manufacturing agglomeration on ammonia nitrogen (NH3-N) is 0.118% through technological innovation, the indirect effect on NH3-N is 0.114% through economic growth, and the indirect effect on NH3-N is 0.254% through industrial structure. Due to the low overall level of the manufacturing industry and its reliance on dirty technologies, the indirect effects of industrial agglomeration are not conducive to improving the quality of the water ecological environment. Therefore, it is necessary to establish a long-term mechanism to promote the evolution of the regional economy along a path that is conducive to the improvement of the water ecological environment.

[A preliminary study on the mixed teaching of human parasitology based on MOOC resources and the experimental teaching digital platform]

The mixed teaching model combines the advantages of traditional teaching and network teaching in the "Internet +" era, which has become one of the important trends in the higher education teaching development. In order to follow this development trend, the human parasitology teaching team makes a reasonable use of modern information techniques, actively promotes the construction and application of online resources, and conducts mixed online and offline teaching based on MOOC resources and the experimental teaching digital platform. This mixed teaching model has shown a positive impact on both teaching and learning among teachers and students; however, students' personalized independent and deep learning remains unsatisfactory. It is suggested that the online course resources construction, teaching design and digital literacy remain to be increased, so as to create a high-level, innovative and challenging online-offline mixed "golden course".

[Antibiotic analysis and whole genome sequencing of two nocardia farcinica strains causing joint infection]

Objective: To analyze the molecular characteristics and antibiotic susceptibility of two strains of Nocardia farcinica isolated from patients with joint infection using whole genome sequencing. Methods: Two strains of Nocardia farcinica causing knee-joint infections in two elderly patients were collected in January 2020. Whole genome sequencing was used to determine the nocardia species. Drug sensitivity test was performed using the micro-broth dilution and E-test method according to CLSI M24 guideline. ABRicate was used to analyze drug resistance and virulence genes. Snippy and other bioinformatic tools were used for genomic comparison, and to construct SNP homologous tree. Results: The clinical isolates in this study were both Nocardia farcinica. Antimicrobial susceptibility test showed the isolates were resistant to ceftriaxone, cefepime, cefotaxime and trimethoprim/sulfamethoxazole (TMP/SMX). Imipenem, linezolid and amoxicillin-clavulanic acid showed good activity. Four antibiotic resistance genes including class A β-lactamase gene far-1, RNA polymerase binding protein gene RbpA, multi-drug resistance efflux pump transcription activator gene MtrA and regulatory transcription factor gene vanR-O were identified in the Nocardia farcinica genomes, which conferred resistance to beta-lactams, rifampicin, macrolides and vancomycin respectively. No acquired TMP/SMX resistance genes were identified. There are multiple missense mutations in the dihydrofolate reductase family genes. Four virulence genes of icl, mbtH, phoP, and relA that are homologous to Mycobacterium tuberculosis were found. SNP homologous tree analysis showed the two Nocardia strains were closely related, and there were only ten SNP sites, six compound substitutions and one deletion mutation between them. Conclusions: Whole genome sequencing technology is helpful to explore the molecular characteristics and resistance mechanisms of Nocardia species. Nocardia farcinica has a trend of spreading in China. Resistance to TMP/SMX is worthy of attention. The mutation of genes involved in the metabolic pathway of dihydrofolate might be one of multiple TMP/SMX resistance mechanisms.

Efficient, green, and rapid strategy for separating actinomycin D and X2 using supercritical fluid chromatography

Actinomycin D has long been used as a first-line antitumor drug in clinical practice. Actinomycin X₂, a new drug lead, is often isolated along with actinomycin D. The minor differences between the two actinomycin analogs pose a daunting challenge in separation. In this study, supercritical fluid chromatography (SFC) was successfully utilized for the purification of actinomycin X₂ and actinomycin D from a marine derived Streptomyces sp. DQS-5. After one-step SFC purification, the purities of these two compounds were determined to be 97.3 % and 97.8 %, respectively. This method provides a green alternative for the separation of these pharmacologically important actinomycin antibiotics. This study also demonstrated the development of a simple and rapid method for the separation of natural products based on SFC.

[Clinical analysis of 12 cases of spontaneous uterine rupture caused by placenta percreta]

Objective: To investigate the clinical characteristics and early identification of spontaneous rupture of uterus caused by placenta percreta. Methods: The clinical data of 12 patients with spontaneous uterine rupture caused by placenta percreta and admitted to the First Affiliated Hospital of Zhengzhou University from June 2014 to December 2019 were collected. The age, gestational age, gestational history, clinical manifestations, diagnostic methods, uterine operation history, rupture location, surgical method, treatment and outcome were analyzed. Results: (1) General condition: the median age of pregnant women was 37 years (range: 30-43 years), and the median gestational week of uterine rupture was 29⁺⁶ weeks (range: 18⁺³-36⁺³ weeks). (2) Clinical manifestation: among the 12 pregnant women, 9 showed different degrees of abdominal pain; chest distress accompanied by waist soreness, abdominal distension in 2 cases; one asymptomatic pregnant women was found with uterine rupture during elective cesarean section. Preoperative color Doppler ultrasonography indicated that 9 of the 12 pregnant women had peritoneal effusion, and 6 of them underwent diagnostic peritoneal puncture or posterior vault puncture for non-clotting blood extraction. (3) Uterine operation history and rupture location: among the 12 cases of spontaneous rupture of uterus caused by placenta percreta pregnant women, 10 had placenta previa after cesarean section, including 4 cases of rupture at the incision of the original cesarean section, 3 cases of rupture at the penetrating placental implantation of the lower segment of the anterior wall of the uterus, and 1 case of placenta percreta occurred at the myomectomy site of the right angle of the uterus. Among the 2 pregnant women with spontaneous uterine rupture caused by penetrating placental implantation without a history of cesarean section, 1 case with history of multiple abortions, and uterine rupture occurred at the bottom of the palace, 1 had rupture of placental penetrating implantation after hysteroscopic electroresection of endometrial polyps, and the uterine rupture occurred at the anterior wall of the lower segment of the uterus. (4) Maternal and fetal outcomes: 11 pregnant women were injected with suspension RBC and 1 pregnant woman was not injected with blood products. Nine cases underwent hysteroplasty and 3 cases underwent subtotal hysterectomy. There were 11 maternal survivors and 1 maternal death; 7 neonates survived and 6 stillbirths. Conclusions: Uterine rupture caused by placenta percreta is of great harm to mother and infant, due to its heterogeneity in clinical manifestations, which increases the possibility of misdiagnosis. For pregnant women with risk factors of placenta percreta, early diagnosis should be made during pregnancy. For those who have been diagnosed with placenta percreta, when there is typical or atypical uterine rupture, doctors should be alert to the occurrence of uterine rupture.

Large Isospin Asymmetry in ^{22}Si/^{22}O Mirror Gamow-Teller Transitions Reveals the Halo Structure of ^{22}Al

β-delayed one-proton emissions of ^{22}Si, the lightest nucleus with an isospin projection T_{z}=-3, are studied with a silicon array surrounded by high-purity germanium detectors. Properties of β-decay branches and the reduced transition probabilities for the transitions to the low-lying states of ^{22}Al are determined. Compared to the mirror β decay of ^{22}O, the largest value of mirror asymmetry in low-lying states by far, with δ=209(96), is found in the transition to the first 1^{+} excited state. Shell-model calculation with isospin-nonconserving forces, including the T=1, J=2, 3 interaction related to the s_{1/2} orbit that introduces explicitly the isospin-symmetry breaking force and describes the loosely bound nature of the wave functions of the s_{1/2} orbit, can reproduce the observed data well and consistently explain the observation that a large δ value occurs for the first but not for the second 1^{+} excited state of ^{22}Al. Our results, while supporting the proton-halo structure in ^{22}Al, might provide another means to identify halo nuclei.

[The evaluation value of transient elastography for liver characteristics in obese children]

Objective: To evaluate the feasibility of transient elastography (FibroTouch) in obese children and to investigate the liver characteristics of obese children based on FibroTouch. Methods: Children (5-18 years of age) from the Guangzhou Women and Children's Medical Center were examined by FibroTouch. The fat attenuation parameter (FAP) was used to assess liver fat deposition, and liver stiffness measurement (LSM) was used to assess liver fibrosis. The children were divided into obesity group (n=67) and non-obesity group (n=139). The FAP, LSM, and their influencing factors were analysed in the obese group. Results: The total effective rate of FibroTouch in non-sedated children aged 5-18 years (n=229) was 97.8%. The FAP value 259.4 (235.9-275.5) dB/m in obese children was significantly higher than that in the control group 178.1 (168.7-195.6) dB/m, (Z=-10.586, P<0.001). The LSM value in obese children 5.9 (4.5-7.5) kPa was significantly higher than that in non-obese children 3.2 (2.3-4.1) kPa, (Z=-8.832, P<0.001). The proportion of liver fibrosis in obese group was 30%, and that of nonalcoholic fatty liver was 65.7%. Logistic regression analysis showed that BMI percentile (≥ 95%) was an independent factor for significant liver fibrosis (OR=1.267, 95%CI: 1.056-1.519, P=0.011) and nonalcoholic fatty liver disease (OR=1.248, 95%CI: 1.007-1.546, P=0.043). Conclusions: FibroTouch can be successfully applied to obese children. Fibrotouch can accurately evaluate the liver fibrosis and fat attenuation parameters in obese children. Obese children have higher FAP and LSM, which increase the risk of non-alcoholic fatty liver and liver fibrosis.

[Clinical characteristics of patients with indication of cardiac implantable electronic devices implantation complicating with acute pulmonary thromboembolism]

Objective: To investigate the clinical characteristics of inpatients with the indication of cardiac implantable electronic devices (CIED) therapy and combined acute pulmonary thromboembolism (APTE). Methods: We retrospectively screened 8 641 inpatients who admitted with the indication of CIED implantation in Fuwai Hospital from January 2014 to May 2019. The clinical characteristics, management strategies and clinical outcome were analyzed for patients diagnosed as APTE. Results: APTE were identified in 45 (5‰) patients in this cohort, there were 18(40%) male patients, the average age was (73±8) years old and body mass index was (27±10) kg/m².Thirty-two (70%) patients were at intermediate-risk and 13 (30%) at low-risk. Anti-coagulation therapy was initiated in 38(84%) patients, and 30 patients underwent CIED implantation (27 pacemaker, 2 CRT and 1 ICD). No postoperative bleeding or pocket hematoma were detected in the 23 patients taking anticoagulation medication before implantation. During an average of (30±7) months' follow up, thrombus was dissolved in 20 patients, hemorrhage complications were observed in 2 patients (1 cerebral hemorrhage and 1 hematuria), anticoagulation therapy was discontinued in these 2 patients. Among 15 patients without immediate CIED implantation and treated with anticoagulation therapy during hospitalization, 2 patients developed complete paroxysmal Ⅲ° atrioventricular block, and recovered after therapy during hospitalization. Seven patients were re-hospitalized for CIED implantation due to bradycardia. Five patients died during follow-up (3 sudden cardiac death, 1 APTE combined with cerebral infarction, and 1 pulmonary infection). Conclusion: APTE is not rare in patients with the indication of CIED implantation, CIED implantation and anti-coagulation therapy are safe for these patients, and transient atrioventricular block could be detected in APTE patients.

Analysis of a registry database for esophageal cancer from high-volume centers in China

Esophageal cancer has a high incidence among malignancies in China, but a comprehensive picture of the status of its surgical management in China has hitherto not been available. A nationwide database has recently been established to address this issue.

METHOD

A National Database was setup through a network platform, and data was collected from 70 high-volume centers (>100 esophagectomies/per year) across China. Data was entered between January 2009 and December 2014, and was analyzed in June 2015 after a minimal follow-up of 6 months for all patients. 8181 patients with complete data who received surgery for primary esophageal cancer on the Database were included in the analysis.

RESULT

In this series, there were 6052 males and 2129 females, with a mean age of 60.5 years (range: 22-90 years). The pathology in 95.5% of patients was squamous cell carcinoma. The pathological stage distribution was 1.2% in stage 0, 2.5% in Ia, 11.5% in Ib, 14.8% in IIa, 36.1% in IIb, 19.3% in IIIa, 8.3% in IIIb, 6.2% in IIIc. 1800 patients (22.0%) with locally advanced disease received preoperative neoadjuvant therapy and 3592 patients (43.9%) underwent postoperative adjuvant chemotherapy and/or radiotherapy. The esophagectomies were performed through left thoracotomy approach in 5870 cases (72.6%), through right chest approach in 2215 cases (27.4%) including right thoracotomy (21.3%) and VATS (6.1%). The 30-day postoperative mortality rate was 0.6% (43 patients), and the overall postoperative complication rate was 11.6% (951 patients). The 1-, 3-, and 5-year overall survival rates were 82.6%, 61.6%, and 52.9%, respectively.

CONCLUSION

This National Registry Database from high-volume centers provides a comprehensive picture of surgical management for esophageal cancer in China for the first time. Squamous cell carcinoma predominates, but there is heterogeneity with respect to the surgical approach and perioperative oncologic management. Overall, surgical mortality and morbidity rates are low, and good survival rates have been achieved due to improvement of surgical treatment technology in recent years.

[Effect of pedicled thoracodorsal artery perforator flap on the repair of moderate to severe axillary scar contracture deformity]

Objective: To investigate the effect of pedicled thoracodorsal artery perforator (TDAP) flap on the repair of axillary moderate to severe scar contracture deformity. Methods: From January 2012 to January 2017, 29 patients with axillary moderate to severe scar contracture deformity were admitted to the the Second Xiangya Hospital of Central South University, including 18 females and 11 males, aged 14-42 years. There were 3 patients with cicatricial contracture deformity of bilateral axillas and 26 patients with cicatricial contracture deformity of unilateral axilla. After relevant preoperative examinations were completed and basic diseases were controlled, axillary scar was removed or released under the anesthesia of endotracheal intubation. The areas of wounds ranged from 7.5 cm×5.0 cm to 21.0 cm×8.5 cm after the operation. The pedicled TDAP flaps were used to repair the defects, which were thinned based on demand of the recipient sites before being transferred. The areas of flaps ranged from 9.0 cm×6.0 cm to 22.0 cm×10.0 cm. The donor sites were sutured directly. The status of thinned flaps, the survival of flaps after the operation and during follow-up, and the shoulder joint function during follow-up were observed. Results: Thirty-two pedicled TDAP flaps were harvested for repairing the defects. Among them, 14 flaps were transferred directly without thinning and the thickness of the flaps ranged from 9.0 mm to 15.0 mm, with average thickness of 13.6 mm.While the other 18 flaps were thinned, and the thickness of the thinned flaps ranged from 5.0 mm to 8.0 mm, with average thickness of 7.5 mm. The distal parts of 3 flaps in 3 patients showed small size of blackening or necrosis within 72 hours after the operation, and 2 of them were thinned and the other one was not. Finally, the 3 flaps were healed after hyperbaric oxygen therapy, dressing change, or other treatments. One flap occurred vein congestion 8 hours after the operation caused by pressure on the pedicle, and the color of the flap turned back to normal after the pressure was relieved. The rest of the flaps survived well. All the patients were followed up for 9 to 36 months, with an average of 18 months. All the flaps survived well, the color of the flaps was nearly the same as the recipient sites, and none of the flaps developed obvious contraction. The shoulder joint function of all patients was significantly improved compared with that before operation, with abduction angles of shoulder joints ranged from 90.0-145.0°, with an average of 130.0°. Conclusions: Pedicled TDAP flap is an relatively ideal choice for the repair of moderate to severe axillary scar contracture deformity, and better results will be achieved if the flaps are thinned to a appropriate thickness according to the condition of axillary defects.

[Cost-effectiveness of HIV self-testing strategy in men who have sex with men]

Objective: To analyze the cost-effectiveness and willingness-to-pay of HIV self-testing (HIVST) strategy and facility-based HIV rapid testing (HIV-RDT) strategy in men who have sex with men (MSM) in Zhuhai, and provide scientific evidence for making health policy. Methods: From the perspective of health service providers, the data of the costs and effectiveness of two HIV testing strategies in MSM in Zhuhai during January-September 2019 were collected, and a decision-tree model of cohort of 10 000 MSM was constructed by using software TreeAge Pro 2019 to measure the cost-effectiveness ratio (CER) and the incremental cost-effectiveness ratio (ICER). One-way and probability sensitivity analysis was performed for the uncertainty of the parameters in the model, and the cost-effectiveness and affordability curve was introduced to estimate the affordability of two strategies. Results: After the mobilization of MSM community-based organization through Internet and social media, 2 303 MSM had HIVST, in whom 33 were HIV positive (1.7%), and 816 MSM received HIV-RDT, in whom 35 were HIV positive (4.3%). The cost for per screening was 60.45 yuan and 240.43 yuan (RMB) respectively, and the cost for per positive screening was 4 218 yuan and 5 606 yuan (RMB) rerspectively. The results of the decision-tree model showed that the mean cost for a MSM using HIVST and using HIV-RDT was 44.67 yuan and 148.42 yuan (RMB) respectively, and the ICER was negative. HIVST strategy was a more cost-effective option when the willing-to-pay was below 6 528 yuan (RMB) for per positive screening, and HIV-RDT strategy was a more cost-effective option when the investment was higher than 6 528 yuan (RMB). Conclusion: HIVST strategy in Zhuhai is a public health project with economic value, and policy makers should strengthen the support to MSM community-based organization to promote the application of HIVST among MSM.

Macrophage regulation of graft-vs-host disease

Hematopoietic stem cell transplantation has become a curative choice of many hematopoietic malignancy, but graft-vs-host disease (GVHD) has limited the survival quality and overall survival of hematopoietic stem cell transplantation. Understanding of the immune cells’ reaction in pathophysiology of GVHD has improved, but a review on the role of macrophages in GVHD is still absent. Studies have observed that macrophage infiltration is associated with GVHD occurrence and development. In this review, we summarize and analyze the role of macrophages in GVHD based on pathophysiology of acute and chronic GVHD, focusing on the macrophage recruitment and infiltration, macrophage polarization, macrophage secretion, and especially interaction of macrophages with other immune cells. We could conclude that macrophage recruitment and infiltration contribute to both acute and chronic GVHD. Based on distinguishing pathology of acute and chronic GVHD, macrophages tend to show a higher M1/M2 ratio in acute GVHD and a lower M1/M2 ratio in chronic GVHD. However, the influence of dominant cytokines in GVHD is controversial and inconsistent with macrophage polarization. In addition, interaction of macrophages with alloreactive T cells plays an important role in acute GVHD. Meanwhile, the interaction among macrophages, B cells, fibroblasts, and CD4+ T cells participates in chronic GVHD development.

[Epidemiological characteristic and current status of surgical treatment for esophageal cancer by analysis of national registry database]

Objective: To investigate the epidemiological characteristics and current status of surgical management for esophageal cancer in China. Methods: A national database was setup through a network platform. The clinical data of esophageal cancer treated by surgery was collected from 70 major hospitals in China between January 2009 and December 2014. Results: Complete data of 8 181 cases of esophageal cancer patients who underwent surgery were recorded in the database and recruited in the analysis. Among them, 6 052 cases were male and 2 129 were female, the average age was 60.5 years.The epidemiological investigation results showed that 148 cases (1.8%) had history of psychological trauma, 7 527 cases (92.0%) were lower social economic status, 5 072 cases (62.0%) were short of fresh vegetables and fruits, 6 544 cases (80.0%) ate rough food frequently, 3 722 cases (45.5%) drank untreated water directly from lake or river or shallow well, 3 436 cases (42.0%) had a unhealthy eating habit, including habits of eating food fast (507 cases, 6.2%), eating hot food or drinking hot tea/soup (998 cases, 12.2%), eating fried food (1 939 cases, 23.7%), 4 410 cases (53.9%) had the habits of smoking cigarettes and 2 822 cases (34.5%) drank white wine frequently.The pathological results showed that 7 813 cases (95.5%) were squamous cell carcinoma, 267 cases were adenocarcinoma (3.3%), 25 cases were adenosquamous cell carcinoma (0.3%) and 50 cases were small cell carcinoma (0.6%). A total of 1 800 cases (22.0%) received preoperative neoadjuvant therapy due to locally advanced disease or difficulty of resection. The esophagectomies were performed through left thoracotomy approach in 5 870 cases (71.8%), through right chest approach in 2 215 cases (27.1%), and the remain 96 cases (1.2%) received surgery though other approaches.A total of 8 001 cases (97.8%) underwent radical resection, the other 180 cases (2.2%) received palliative resection. The 30-day postoperative mortality rate was 0.5%, the overall ≥ grade Ⅱ postoperative complication rate was 11.6% (951 cases). The 1-yr, 3-yr, and 5-yr overall actual survival rates were 82.6%, 61.6%, and 52.9%, respectively. Conclusions: The data analysis of the national database for esophageal cancer shows that bad eating habits or eating rough food without enough nutrients, lower social and economic status, drinking white wine and smoking cigarettes frequently may be correlated with tumorigenesis of esophageal cancer. However, strong evidences produced by prospective observation studies are needed. Overall, the long-term survival of esophageal cancer patients has been improved gradually due to the application of advanced surgical techniques and reasonable multimodality treatment.

[Correlation research between imaging performance and pulmonary function of pneumoconiosis patients at stage three]

Objective: To study the imaging performance and pulmonary function of pneumoconiosis patients at stage three. Methods: 89 cases of pneumoconiosis patients at stage three for high thousand volt back chest, chest CT, pulmonary function, analysis the relationship of high thousand volt back chest, chest CT manifestations and pulmonary function. Results: In patients with chest X-ray progressive massive fibrosis range of 2.31-102.95 cm(2), divide patients according to the X-ray performance into three groups, the difference of each group pulmonary function index FVC、FEV(1)、PEF、MEF(75%)、MEF(50%)、MEF(25%)、MVV is statistically significant (P<0.01) , the difference of FEV(1)/FVC%、RV/TLC、DLCO is no statistical significance (P>0.05) . Checked by related, in pneumoconiosis patients at stage three, the X-ray manifestations and pulmonary function index FVC、FEV(1)、FEV(1)/FVC%、PEF、MEF(75%)、MEF(50%)、MEF(25%)、MVV、DLCO showed a negative correlation (r=-0.326, -0.438, -0.251, -0.344, -0.317, -0.337, -0.425, -0.347, -0.230) . With the deterioration of the X-ray imaging findings, pulmonary function index FVC、FEV(1)、FEV(1)/FVC%、PEF、MEF(75%)、MEF(50%)、MEF(25%)、MVV、DLCO is a trend of decrease (P<0.05) . The X-ray changes is not associated with RV/TLC. By linear regression analysis, FVC、FEV(1)、FEV(1)/FVC%、PEF、MEF(75%)、MEF(50%)、MEF(25%)、MVV、DLCO regression equation are meaningful. The RV/TLC regression equations is meaningless. The volume of the patients with chest CT progressive massive fibrosis range of 4.86~179.74 cm(3), divide patients according to the chest CT performance into three groups, the difference of each group pulmonary function index FVC、FEV(1)、PEF、MEF(75%)、MEF(50%)、MEF(25%)、MVV、RV/TLC is statistically (P<0.05) , the difference of FEV(1)/FVC%、DLCO is no statistical significance (P>0.05) . Checked by related, in pneumoconiosis patients at stage three, chest CT manifestations and pulmonary function index FVC、FEV(1)、FEV(1)/FVC%、PEF、MEF(75%)、MEF(50%)、MEF(25%)、MVV showed a negative correlation (r=-0.360, -0.419, -0.256, -0.432, -0.366, -0.326, -0.254, -0.405, ) , It is not associated with the RV/TLC、DLCO. With the deterioration of the chest CT imaging findings, pulmonary function index FVC、FEV(1)、FEV(1)/FVC%、PEF、MEF(75%)、MEF(50%)、MEF(25%)、MVV is a trend of decrease (P<0.05) . By linear regression analysis, FVC、FEV(1)、FEV(1)/FVC%、PEF、MEF(75%)、MEF(50%)、MEF(25%)、MVV regression equations are meaningful. The RV/TLC、DLCO regression equations are meaningless. Conclusion: It is correlated with chest X-ray, chest CT manifestations and pulmonary function in pneumoconiosis patients at stage three, that could help guide clinicians comprehensive evaluation in patients with pulmonary function status.

[Iodine status of vulnerable populations in Henan Province of China three years after the implementation of new iodized salt standard]

Iodine nutrition surveillance of vulnerable population was conducted in 18 cities of Henan Province in 2015. The medians and quartiles of urinary iodine concentration in women of reproductive-age (n=3 318), pregnant women (n=36 366), lactating women (n=4 153), infants <2 years of age (n=1 017), and children aged 8-10 years (n=4 806) were 202.1(124.0, 310.0), 192.4(133.6, 262.4), 168.3(119.1, 248.3), 214.2(156.1, 272.3) and 90.0 (121.8, 285.6) μg/L, respectively. Iodine status of the vulnerable populations was generally regarded as adequate in Henan Province. But the median of urinary iodine concentration of reproductive-age women were slightly above the adequate level. The proportions above iodine adequate level were 26.7% in reproductive-age women, 29.4% in pregnant women and 22.5% in children aged 8-10 years.

P6017Permanent left bundle branch area pacing for atrioventricular block: feasibility, safety and acute effect

Background

Left bundle branch area pacing (LBBAP), lacks adequate evaluation for AVB.

Purpose

We aimed to assess the feasibility, safety, and acute clinical outcomes of permanent LBBAP in patients with AVB.

Methods

We retrospectively recruited AVB patients with indication for ventricular pacing who had underwent LBBAP from May to Sep. 2018. ECG characteristics, pacing parameters, echocardiographic parameters and adverse events were evaluated during follow-up. Successful LBBAP was defined as the paced QRS morphology of RBBB pattern and QRSd less than 130ms.

Results

A total of 33 patients were involved in this study (mean age: 55.1±18.5 years; 66.7% male, 48.4% with bundle branch block,BBB). LBBAP was successfully performed in 90.9% (30/33) of all patients. The mean capture threshold of LBBAP was 0.76±0.26 V/0.4 ms during the procedure and 0.64±0.20 V/0.4ms at 3-month follow-up. The paced QRSd was 112.8±10.9 ms during the procedure and 116.8±10.4ms at 3-month follow-up. Baseline left or right BBB was corrected by LBBAP (153.3±27.8 ms vs. 122.2±9.9 ms) with a success rate of 68.7% (11/16). One ventricular septal lead perforation occurred soon after the procedure and LBBAP was successfully repeated by lead revision. Cardiac function and left ventricular synchronization at three-month follow-up presented slightly improvement as compared with baseline.

Table 1. Complications and changes in pacing parameters within 3 months after LBBAP Pacing parameters LBBAP (N=30) During the procedure Before discharge 3-month follow up Sensing amplitude, mV 14.4±5.1 15.8±11.7 14.6±4.6 Pacing threshold@0.4ms, V 0.76±0.26 0.59±0.16 0.64±0.20 Pacing impedance, Ω 691.7±133.8 588.0±79.3 554.7±93.7 Paced QRSd at 3.0V@0.4 ms output, ms 112.8±10.9 114.4±14.2 116.8±10.4 VP, % NA NA 79.4±24.6 Complications, n (%) 1 (3.3) 0 (0.0) 0 (0.0) Infection, n (%) 0 (0.0) 0 (0.0) 0 (0.0) Septal perforation, n (%) 1 (3.3) 0 (0.0) 0 (0.0) Dislodgement, n (%) 0 (0.0) 0 (0.0) 0 (0.0) QRSd, QRS duration; VP, ventricular pacing percentage.

Figure 1. Characteristics of LBBAP

Conclusion

Permanent LBBAP yielded stable threshold, narrow QRSd and preserved left ventricle synchrony with few complications. Our preliminary results indicate that LBBAP holds promise as an attractive physiological pacing strategy for AVB.

[Clinical analysis of scimitar syndrome in 6 pediatric patients]

Objective: To characterize the clinical features and outcomes of scimitar syndrome (SS) to aid the understanding of this syndrome. Methods: This retrospective study included 6 children who were diagnosed with SS at the pediatric cardiovascular center of Beijing Anzhen Hospital from January 2012 to September 2018. SS was diagnosed by echocardiography and confirmed by cardiac computed tomography angiography(CTA) or surgery. All data were collected to analyze the clinical and imaging characteristics and prognosis. Results: Among the 6 SS children (aged 2 months to 15 years; 5 males) weighed 5.6-17.1 kg. Three cases were infant type, the clinical manifestations were recurrent respiratory tract infection with growth retardation, including 2 cases with severe pulmonary hypertension, while 3 cases with adult type, were asymptomatic. Cardiac CTA imaging showed that the right single or all pulmonary veins descended through the diaphragm and converged into the inferior vena cava. One case was isolated infracardiac partial anomalous pulmonary venous connection (PAPVC) without other malformations. The remaining 5 cases complicated with atrial septal defect, different vascular and trachea malformations as well as spinal malformations. Vascular malformations included pulmonary veins stenosis, abnormal origin of pulmonary artery branches, collateral branches of systemic artery supplying local lung tissue, and persistent left superior vena cava. The treatment varied according to the specific location of anomalous pulmonary venous connection, the degree of pulmonary hypertension and the severity of clinical symptoms. Four cases underwent one-stage radical surgery, one case accepted intervention to occlude the collateral artery which was supplying the right lower lung and received stage Ⅱ radical surgery half a year later, and the remaining one case died from pulmonary hypertension crisis preoperation. Conclusions: Isolated SS can easily miss diagnosis due to mild clinical symptoms. Patients with complicated malformations can benefit from combination therapy. SS associated with severe pulmonary hypertension can lead to early death. Therefore, early diagnosis and appropriate treatment can improve the prognosis of patients.

[Clinical analysis of seven cases of H1N1 influenza-associated encephalopathy in children]

Objective: To investigate the clinical manifestations, diagnosis, and treatment of H1N1 influenza A-associated encephalopathy (IAE) in children. Methods: The clinical manifestations, laboratory tests, cranial magnetic resonance imaging (MRI), electroencephalography (EEG) examinations and treatments of seven children with H1N1 IAE hospitalized in Guangzhou Women and Children's Medical Center from December 2018 to January 2019 were retrospectively analyzed. Results: Five of the seven children with H1N1 IAE were female. The age at admission was 4 years and 5 months (range 7 months-9 years). Neurological symptoms occurred simultaneously or early (0-3 days) after the flu-like symptom appeared. The main clinical manifestations of neurological symptoms were seizures (repeated seizures in five cases and status convulsion in two cases, including one case of unexpected fever and repeated seizures in a nine-year old girl) accompanied with altered consciousness (drowsiness in five cases and coma in two cases). Cranial MRI in three cases displayed multifocal lesions, mainly in the bilateral thalamus, brainstem and cerebellar hemisphere. MRI also showed reversible splenial lesion in the corpus callusumin in three cases. EEG tracings were characterized by diffuse slow wave activity in four cases, and status epilepticus was monitored in one case. All the 7 cases were treated with oral oseltamivir. Three cases were treated with pulsed methylprednisolone and intravenous immunoglobulin. One case was treated with intravenous immunoglobulin alone and all the patients received oral oseltamivir. All the patients survived, with three patients had minor neurological sequelae at discharge. Conclusions: The main clinical manifestations of H1N1 IAE are seizures and altered consciousness. Cranial MRI combined with EEG is helpful for early diagnosis. Intravenous immunoglobulin and (or) methylprednisolone should be considered for severe cases.

Acute Toxicity and Hazardous Concentrations of Zinc to Native Freshwater Organisms Under Different pH Values in China

Zinc bioavailability to aquatic organisms varies greatly under different pH values. In the present study, five native species in China and four common international test species were selected to investigate the influence of changing pH on acute zinc toxicity. The results showed that the higher trophic levels exhibited increasing sensitivity to zinc as pH decreased. However, when the pH value was between 8 and 11, the acute toxicity of zinc was relatively constant. In addition, by using a species-sensitivity distribution (SSD) method, the short-term hazardous concentrations of zinc at different pH values (based on the 5th percentiles of the pH-specific SSDs) were determined to be 17.26 µg/L (pH 4), 48.31 µg/L (pH 5), 80.34 µg/L (pH 6) and 230.6 µg/L (pH 7), respectively. The present study provides useful information for deriving water quality criteria and assessing the risks of metals in the near future.

[BRAF gene mutations in ameloblastic fibromas]

OBJECTIVE

To investigate the BRAF gene mutations in ameloblastic fibroma (AF), and to further analyze the relationship between the BRAF mutation and clinical characteristics so as to provide new reference to the study of AF's molecular pathology.

METHODS

Sixteen cases diagnosed as AF at the Department of Oral Pathology, Peking University School of Stomatology between January 1990 and December 2017 were collected. Genomic DNA was extracted from formalin-fixed, paraffin embedded tissues using the QIAamp DNA Mini Kit (Qiagen, Germany) according to the manufacturer's instructions. Polymerase chain reaction (PCR) and direct sequencings were used to detect the BRAF gene mutations. The clinicopathological data, such as the age, location of the lesion, symptoms and treatments were retrospectively analyzed.

RESULTS

The sixteen cases of AF involved nine women and seven men aged 2-67 years. Three lesions occurred in the maxilla and thirteen in the mandible. The most common presenting symptom of AF was a painless slowly enlarging mass with swelling. Ten patients received conservative treatment and the other six patients received radical surgery. Three cases relapsed during the study period. BRAF gene mutation was found in sixteen of all the sixteen samples analyzed (100%). The BRAF mutation was a point mutation with a thymine-adenine transversion at nucleotide 1 799 of 15 exons, resulting in a change at residue 600 that substituted glutamine for valine. This mutation was the strongest activator of the downstream RAS/RAF/MEK/ERK-MAPK signaling pathway. This helped to bring about a gain-of-function mutation due to a V600E substitution. Many studies identified that BRAF regulated survival, apoptosis, and proliferation of cells by inducing MAPK pathways activation. For the existing cases, none of the age, sex, location, recurrence and treatments had a statistically significant correlation with BRAF mutation.

CONCLUSION

Our findings demonstrated high prevalence of BRAF V600E mutation in AF. The pathogenic role remains to be clarified．.

[The relationship between autoimmune thyroiditis and pregnancy outcomes of patients with PCOS following in vitro fertilization and embryo transfer IVF-ET]

Objective: To investigate the impact of autoimmune thyroiditis (AIT) on pregnancy outcomes in patients with polycystic ovary syndrome (PCOS) following the in vitro fertilization and embryo transfer (IVF-ET) by analyzing their pregnancy outcomes. Methods: The patients undergoing IVF-ET treatment diagnosed with PCOS in Peking University Third Hospital from May 2010 to December 2014 were investigated. According to the anti-thyroid antibodies (TPOAb or TGAb), patients were divided into AIT group and non-AIT group. The pregnancy outcomes of two groups were analysed for investigate the effect of AIT on pregnancy outcomes. Results: Four hundred and ninety patients with PCOS were enrolled, 119 (24.3%) of AIT group and 371 (75.7%) of non-AIT group. Patients with PCOS had a higher incidence (24.3%) of AIT. There was no correlation between AIT and the different pregnancy outcomes.TSH was negatively correlated with pregnancy as a risk factor. Hyperandrogenemia was negatively correlated with clinical pregnancy as a risk factor. Hyperprolactinemia was negatively correlated with delivery as a risk factor, while TSH was positively correlated with delivery. Conclusions: The incidence of AIT was higher in patients with PCOS. AIT was not the risk factor of adverse pregnancy outcomes for PCOS women undergoing IVF. The metabolic disorders (including hyperinsulinemia, hyperandrogenemia and hyperprolactinemia) were the risk factors of adverse pregnancy outcomes. Patients in AIT group had the high TSH level. They should be received more care and monitoring to make it conducive to delivery.

[Three-level logistic analysis related to influencing factors on condom use among female sex workers aged 35 years and above in Qingdao]

Objective: To analyze the influencing factors on condom use among 35-years-or-older female sex workers (OFSWs) in Qingdao by using the three-level logistic model. Methods: From March to June 2014, OFSWs were recruited in Qingdao, using respondent-driven sampling. Related information on OFSWs and their recent five sexual partners (not including husband) were obtained by conducting a questionnaire survey on OFSWs. A Three-level logistic regression model was conducted to analyze the influencing factors of condom use between OFSWs and their sexual partners. Results: A total of 420 OFSWs participated the survey as well as information on 2 100 sexual partners. Results from the empty model showed that the use of condoms among OFSWs having an aggregation that related to the levels of working sites and their own behaviors. Results from the three-levels of logistic model analysis showed that, OFSWs that having had junior middle school education (OR=1.450, 95%CI: 1.054-1.994)/high school education or above (OR=2.264, 95%CI: 1.215-4.222), knowing the function of condom use (OR=2.004, 95%CI: 1.273-3.154) would have higher rates of condom use. OFSWs with higher score of attitude on condom use (OR=0.796, 95%CI: 0.745-0.849), having had syphilis infections in the past (OR=0.657, 95%CI: 0.478-0.902) would have lower rate of condom use. For the sexual partners, the rate of condom use among OFSWs' regular partners were higher than that of OFSWs' boyfriends (OR=15.291, 95%CI: 8.441-27.700; OR=29.032, 95%CI: 15.413-54.682). Conclusion: Condom use of OFSWs was affected by behaviors of both OFSWs themselves and their sexual partners. Prevention and control programs should focus on OFSWs and their sexual partners at the same time. The key intervention contents should include target populations as: OFSWs with low level of education, having had infections of syphilis, those who do not use condoms with their trusted partners.

[The predictive value of parathyroid hormone levels and decreases for postoperative hypocalcemia after total thyroidectomy]

Objective:To investigate the predictive value of parathyroid hormone levels and decreases for postoperative hypocalcemia after total thyroidectomy. Method:We reviewed 71 consecutive patients who underwent total thyroidectomy, measured postoperative hypocalcemia, parathyroid hormone (PTH) values within 24 hours after surgery, divided them into subgroups accroding to hypocalcemia symptom. Combining with postoperative serum calcium，postoperative PTH values and decreases (△PTH), we used the receiver operating characteristic curve (ROC) analysis to assessment of predictive value. Result:The mean value of postoperative serum calcium, postoperative PTH and △PTH between subgroups have a significant difference (P<0.01). ROC area under the curve (AUC) of △PTH is 0.9706, with cutoff value 0.7366. AUC of postoperative PTH is 0.9580, with cutoff value 14.82 ng/L. Conclusion:The postoperative PTH and △PTH is a reliable indicator to judging postoperative hypocalcemia after total thyroidectomy.