[Analysis on the technical characteristics and clinical efficacy of robotic-assisted intersphincteric resection for patients with low rectal cancer]

Objective: To explore the technical characteristics and short-term clinical efficacy of robotic-assisted intersphincteric resection (ISR) for patients with low rectal cancer. Methods: A retrospective cohort study was used. Inclusion criteria: (1) rigid colonoscopy showed lower margin of the tumor ≤5 cm from the anal verge; (2) preoperative rectal MRI or endorectal ultrasound revealed staging T1-2, or T3 patients receiving concurrent chemoradiotherapy; (3) patients less than 70 years old with good function of anal sphincter before surgery; (4) no synchronous multiple primary carcinoma, and no distant metastasis; (5) the method of operation was agreed by the patient. Exclusion criteria: (1) T4 stage tumors; (2) sphincter dysfunction before operation; (3) recurrent tumors; (4) lower edge of tumors beyond the dentate line; (5) death due to non-rectal cancer during follow-up and unsatisfactory follow-up data. The clinical data of 21 patients with low rectal cancer meeting inclusion criteria undergoing robotic-assisted ISR at our department from January 2015 to June 2018 were collected. Parameters during and after operation were observed. Anorectal manometry was performed at 3, 6, and 12 months after the operation, and anal function was evaluated at 3, 6, and 12 months after the closure of the stoma by Kirwan classification and Wexner fecal incontinence score. The key steps of the operation are as follows: according to the principle of total mesorectal excision, the robot continued to enter into the levator ani hiatusdistally, and dissectin the sphincter space; according to the scope of sphincter resection, ISRwas divided into partial ISR, subtotal ISR, and total ISR; subtotal and total ISR usually needed to be combined with transanal pathway. The reconstruction of digestive tract was performed by double stapler anastomosis under laparoscope orhand-sewnanastomosis under direct vision, and preventive ileostomy was completed in the right lower abdomen. Results: Of 21 patients, 13 were male and 8 were female with mean age of (57.5±16.3) years. All the patients successfully completed the operation without conversion to laparotomy. Fourteen cases (66.7%) adopted partial ISR through complete transabdominal approach, 6 cases (28.6%) adopted the subtotal ISR through combined transabdominal and transanal approachs, and 1 case (4.8%) adopted the total ISR through the combined transabdominal and transanal approachs. The total operation time was (213.1±56.3) minutes, including (27.3±5.4) minutes for mechanical arm installation and (175.7±51.6) minutes for robotic operation. The amount of intraoperative hemorrhage was (62.8±23.2) ml, and no blood transfusion was performed in any patient. All patients underwent prophylactic ileostomy, and the stoma was closed 3-6 months after the operation. Except one case of anastomotic leakage, all other stomas were closed successfully. The postoperative hospitalization time was (7.6±2.2) days, and time to fluid intake was (3.3±0.9) days. One case of anastomotic leakage, one case of anastomotic stenosis, one case of inflammatory external hemorrhoids and one case of urinary retention occurred after surgery,and all of them were cured by conservative treatment. The mean diameter of tumors was (2.9±1.2) cm, and the number of harvested lymph node was 12.8 ± 3.3. In the whole group, the circumcision margin was negative, the proximal margin was (12.2 ± 2.1) cm, the distal margin was (1.1 ± 0.4) with all negative, and the R0 resection rate was 100%. The results of anorectal manometry showed that the preoperative rest pressure, rectal maximum squeeze pressure, initial sensory volume and maximum tolerated volume were (45.19±8.46) mmHg, (128.18±18.80) mmHg, (44.33±10.11) ml and (119.00±19.28) ml, respectively;these parameters reduced significantly 3 months after operation and they were (23.44±5.54) mmHg, (93.72±12.15) mmHg, (17.72±5.32) ml and (70.44±10.9) ml, respectively. The differences were statistically significant (all P<0.001). The resting pressure and the rectal maximum squeeze pressure returned to preoperative levels 12 months after operation, which were (39.33±6.64) mmHg and (120.58±16.47) mmHg, respectively (both P>0.05), while the initial sensory volume and the maximum tolerated volume failed to reach the preoperative state, which were (30.67±7.45) ml and (92.25±10.32) ml, respectively (both P<0.05). The patients were followed up for (22.1±10.6) months without local recurrence and distant metastasis. Eighteen patients were evaluated for anal function: Kirwan classification was grade I for 6 cases, grade II for 7 cases, grade III for 4 cases, and grade IV for 1 case; Wexner incontinence score was 8.6±0.8; 14 cases had good defecation control. Conclusion: The clinical efficacy of ISR with Da Vinci robot in the treatment of low rectal cancer is satisfactory.

[Safety of del Nido cardioplegia in coronary artery bypass grafting combined with heart valve replacement in adults]

Objective: To investigate the safety and myocardial protective effect of del Nido cardioplegia in coronary artery bypass grafting combined with heart valve replacement in adults. Methods: From April 2018 to April 2019, 84 patients undergoing coronary artery bypass grafting combined with heart valve replacement under cardiopulmonary bypass (CPB) in the Second Affiliated Hospital of Nantong University and Shanghai Chest Hospital were selected, and divided into del Nido cardioplegia (n=44) group and Thomas cardioplegia (n=40) group using a random number table. The concentration of troponin was measured before anesthesia induction and 2, 12 and 24 hours after the termination of CPB, respectively. Results: The preoperative characteristics of each group were similar, including age, underlying diseases, and body surface area (all P>0.05). The frequency of intraoperative cardioplegia infusion in the del Nido group was significantly lower than that in the Thomas group (P=0.03). Compared with the del Nido group, troponin concentration in the Thomas group increased significantly at 12 hours [(4.59±0.76) μg/L vs (2.20±0.53) μg/L, t=-16.653, P<0.001] and 24 hours [(6.70±0.97) μg/L vs (1.96±0.58) μg/L, t=-26.975, P<0.001] after CPB. No statistically significant differences were found in the postoperative recovery of cardiac autonomic rhythm (P=0.887), cardiac defibrillation (P=0.880), positive inotropic drugs (P=0.163) and left ventricular ejection fraction (P=0.338) between the two groups. Conclusions: It is safe to use del Nido cardioplegia in coronary artery bypass grafting combined with heart valve replacement in adults, which can reduce the frequency of cardioplegia infusion and simplify the surgical procedure. The trend of troponin concentration suggests that del Nido cardioplegia has a better myocardial protective effect.

Parent-of-origin has no detectable effect on survival days of Marek's disease virus infected White Leghorns

Marek's Disease (MD) is a neoplastic disease of chickens and remains as a chronic infectious disease that threatens the poultry industry. Improving genetic resistance to MD in poultry is an important long-term goal, which would significantly augment the current control measures against MD and eventually reduce the annual economic loss. In this study, survival patterns of F2 birds from 2 reciprocal crosses were compared to examine possible difference in survival between the reciprocal crosses in response to MD virus (MDV) challenge. A total of 246 and 224 F2 chicks derived from reciprocal crosses of lines 63 × 72 and lines 72 × 63, respectively, were sampled from an MDV challenge trial and survival days were recorded from the MDV-inoculation date to the end of experiment. Statistical analyses, including Principal Component Analysis (PCA) followed by a cox-regression model, showed there was no significant difference in survival days between reciprocal crosses (P > 0.05). To the best of our knowledge, this is the first MD survival study on reciprocal crosses of 2 genetically diversified lines of chickens differing in MD resistance. This report documented the experimental evidence that the genetic lineage of grandparental (maternal or paternal) effect on survival days was minimal, if present at all.

[Effect of downregulation of phosphatase and tensin homolog gene expression on p130crk- related substrate protein and paxillin signal transduction in activated hepatic stellate cells in vitro]

Objective: To investigate the role of adenovirus-mediated short hairpin RNA (shRNA) in down-regulating the expression of phosphatase and tensin homologue deleted on chromosome ten (PTEN) on p130Crk-related substrates(p130Cas) and paxillin signal transduction to activate hepatic stellate cell (HSC) in vitro. Methods: The rat hepatic stellate cell line, HSC-T6 was cultured and activated in vitro. The adenovirus was used as a vector to transiently transfect shRNA targeting PTEN to activate HSC in vitro, and then PTEN low expression model of activated HSC in vitro was established. Western blot and real-time fluorescence quantitative PCR were used to detect the protein and mRNA expression of PTEN, p130cas and paxillin in activated HSC. The experiment was divided into control group (HSC were transfected with DMEM medium instead of adenovirus), Ad-GFP group (HSC were infected with empty the adenovirus expressing green fluorescent protein (GFP) alone), and Ad-shRNA/PTEN group (HSC were infected with the recombinant adenovirus containing both shRNA targeting PTEN and GFP gene). One-way analysis of variance was used for comparison of multiple groups, and LSD test was used for inter-group comparison. Results: shRNA targeting PTEN was successfully transfected and significantly down-regulated the PTEN protein and mRNA expression of HSC in vitro (P < 0.05), and the PTEN low expression model of HSC in vitro was successfully constructed. Compared with the expression of p130cas mRNA in the three groups of HSC, the expression fold of p130cas mRNA in the Ad-GFP group and the Ad-shRNA / PTEN group was 1.01 times and 1.52 times, respectively. The expression of p130cas mRNA in HSC of the Ad-shRNA / PTEN group was significantly higher than control group and Ad-GFP group (P < 0.05), but there was no statistically significant difference between the control group and the Ad-GFP group (P > 0.05). The expression of p130cas protein in the three groups was higher than that in the control group (0.74 ± 0.07) and the Ad-GFP group (0.72 ± 0.02); P < 0.05, but there was no statistically significant difference between the Ad-GFP group and the control group (P > 0.05). The expression of paxillin mRNA in the three groups of HSCs was compared with the expression of paxillin mRNA in the control group of HSC being 1, the expression folds of paxillin mRNA in the Ad-GFP group and Ad-shRNA / PTEN group were 0.97 times and 1.58 times, respectively. The expression of paxillin mRNA in the Ad-shRNA / PTEN group was higher than that in the control group and the Ad-GFP group (P < 0.05), and there was no statistically significant difference between the control group and the Ad-GFP group (P > 0.05). The expression of paxillin protein in the three groups of HSCs was higher in the Ad-shRNA / PTEN group (0.91 ± 0.05) than control group (0.46 ± 0.03) and Ad-GFP group (0.50 ± 0.04), P < 0.05, and there was no statistically significant difference between the Ad-GFP group and the control group (P > 0.05). Conclusion: Down-regulation of PTEN expression can significantly boost p130cas and signal transduction activity of paxillin protein in activated HSC in vitro.

Cell-free Mycobacterium tuberculosis DNA test in pleural effusion for tuberculous pleurisy: a diagnostic accuracy study

OBJECTIVES

Tuberculous pleurisy (TP) diagnosis remains difficult, with the sensitivity of Xpert MTB/RIF (Xpert) and mycobacterial culture (culture) only about 30-50%. We aimed to assess the diagnostic performance of a cell-free Mycobacterium tuberculosis DNA test (cf-TB) in pleural effusion for TP.

METHODS

Adults (≥18 years) with suspected TP presenting with pleural effusion were consecutively recruited, and pleural effusion specimens were prospectively collected in Beijing Chest Hospital, Beijing, China. After centrifuging pleural effusion, sediments were used for culture, Xpert and T-SPOT.TB assay, whereas supernatants were used for cf-TB and adenosine deaminase assay. The diagnostic performance was assessed against a composite reference standard.

RESULTS

From June 2015 to December 2018, we prospectively evaluated 286 adults with suspected TP. One hundred twenty-two participants were classified as definite TP based on the prespecified composite reference standard. The cf-TB produced a sensitivity of 79.5% (97/122, 95% confidence interval (CI) 72.4- 86.7) for definite TP, which was superior to Xpert (38.5% (29.9-47.2); 47/122; p < 0.001) and culture (27.1% (19.2-34.9); 33/122; p < 0.001). With pleural effusion Xpert and/or culture as the reference standard, cf-TB showed 96.6% (57/59, 95% CI 92.0-100.0) sensitivity, which was also significantly higher than Xpert (79.7%, 95% CI 69.4-89.9; 47/59; p 0.004) and culture (55.9%, 95% CI: 43.3-68.6; 33/59; p < 0.001).

CONCLUSIONS

The cf-TB clearly showed improved sensitivity compared with Xpert and culture. We recommend cf-TB as the first-line test for TP diagnosis.

Distinct effects of antihypertensives on depression in the real-world setting: A retrospective cohort study

BACKGROUND

Evidence is increasing that pathways of antihypertensives may have a role in the pathogenesis of depression. However, how the class of antihypertensives affects depression risk remains unclear.

METHODS

The effects of different classes of antihypertensives on depression were explored using an insurance database in Beijing, China. Antihypertensives in our study included calcium channel blockers (CCBs), angiotensin-converting enzyme inhibitors (ACEIs), angiotensin II receptor blockers (ARBs), beta-blockers (BBs), and diuretics (DIUs). Those initially treated with only one class of antihypertensives were included. Stratified analysis was conducted for demographic characteristics, comorbidities, and statin prescriptions.

RESULTS

In total, 181,709 newly detected hypertension patients were included. The median follow-up period was 4.33 years and 19,030 participants were with depression by the end. After adjusting for covariates, the incidence density (95% confidence interval, CI) of depression in the BB, ACEI, DIU, CCB, and ARB groups was 3.16 (2.98-3.33), 3.10 (2.91-3.29), 2.70 (2.45-2.94), 2.67 (2.53-2.81), and 2.30 (2.16-2.43) per 100 person-years, respectively. Compared with ARB group, the hazard ratio (95% CI) of depression for BB, ACEI, DIU, and CCB group was 1.37 (1.32-1.43), 1.35 (1.28-1.42), 1.17 (1.08-1.27), and 1.16 (1.12-1.21), respectively. Stratified analysis suggested the highest depression ID remained within the BB or ACEI group.

LIMITATIONS

Detailed clinical information was unavailable, which may introduce bias. Patients on monotherapy as initial treatment were included and caution is needed for extrapolation.

CONCLUSIONS

Compared with ARBs, there may be a class effect of other antihypertensives on the risk of depression.

Differences between caregiver-perceived and dentist-assessed oral health status of patients among intellectual disabilities

OBJECTIVE

This study compared the caregiver-perceived and dentist-determined oral health status of patients with intellectual disabilities to determine factors that affect caregiver-perception of patients' oral health.

MATERIALS AND METHODS

297 patients [mean (SD) age = 51.9 (12.5) years] and 56 professional caregivers [42.1 (8.2) years] from three institutional facilities took part. Data were acquired via self-administered questionnaires by caregivers and oral examination by dentists. Oral hygiene condition, numbers of decayed and missing teeth, and periodontal disease reported by caregivers and dentists were compared using paired t-test and Pearson correlation. Demographic and dental factors of the patients and caregivers were analyzed using chi square and Fisher's exact tests.

RESULTS

Caregivers underestimated decayed and missing teeth compared to dentists (p⟨0.05). Oral hygiene condition and periodontal disease were similarly rated by the two groups. Tooth brushing, diet type, sex, and overall oral health status of the patients were associated with caregiver perception (p⟨0.05). Career length and time since caregivers last received dental care were also related factors (p⟨0.05).

CONCLUSION

Professional caregivers of adult patients with intellectual disabilities had different perceptions of oral health status based on patient and caregiver circumstances.

MicroRNA-495 inhibits the progression of non-small-cell lung cancer by targeting TCF4 and inactivating Wnt/β-catenin pathway

OBJECTIVE

Different effects of microRNA-495 (miR-495) on human cancers have been exhibited in recent years. However, the specific function of miR-495 remains uncertain in non-small-cell lung cancer (NSCLC). Thus, we aim to explore the role of miR-495 in NSCLC.

PATIENTS AND METHODS

The expressions of miR-495 and transcription factor 4 (TCF4) were detected through quantitative Real-time polymerase chain reaction (qRT-PCR) assay. Western blot was used to measure the protein expression of relative genes. The relationship between miR-495 and TCF4 was testified by the dual-luciferase reporter gene assay. The function of miR-495 was investigated through cell counting kit-8 (CCK-8) assay and transwell assay.

RESULTS

MiR-495 was downregulated in NSCLC tissues. Overexpression of miR-495 inhibited the migration, invasion and proliferation of NSCLC cells. Further, TCF4 was a direct target gene of miR-495. TCF4 was highly expressed in NSCLC tissues. In addition, miR-495 inhibited the progression of NSCLC through targeting TCF4. Furthermore, miR-495 inhibited EMT and Wnt/β-catenin pathway in NSCLC.

CONCLUSIONS

MiR-495 inhibited the progression of NSCLC by targeting TCF4 and inactivating Wnt/β-catenin pathway.

Measurement of ϒ(1S) Elliptic Flow at Forward Rapidity in Pb-Pb Collisions at sqrt[s_{NN}]=5.02 TeV

The first measurement of the ϒ(1S) elliptic flow coefficient (v_{2}) is performed at forward rapidity (2.5<y<4) in Pb-Pb collisions at sqrt[s_{NN}]=5.02  TeV with the ALICE detector at the LHC. The results are obtained with the scalar product method and are reported as a function of transverse momentum (p_{T}) up to 15  GeV/c in the 5%-60% centrality interval. The measured ϒ(1S)v_{2} is consistent with 0 and with the small positive values predicted by transport models within uncertainties. The v_{2} coefficient in 2<p_{T}<15  GeV/c is lower than that of inclusive J/ψ mesons in the same p_{T} interval by 2.6 standard deviations. These results, combined with earlier suppression measurements, are in agreement with a scenario in which the ϒ(1S) production in Pb-Pb collisions at LHC energies is dominated by dissociation limited to the early stage of the collision, whereas in the J/ψ case there is substantial experimental evidence of an additional regeneration component.

Role of microRNA-218-5p in the pathogenesis of chronic obstructive pulmonary disease

OBJECTIVE

Chronic obstructive pulmonary disease (COPD) is an inflammatory lung disease characterized by inflammatory cell activation and the release of inflammatory mediators. By measuring microRNA expression in the plasma of COPD subjects, we aimed to identify the clinical relevance of plasma miRNA levels in these patients.

PATIENTS AND METHODS

A total of 40 COPD patients and 40 healthy controls were enrolled in the study. The COPD model of C57BL/6 mice was also developed by exposing them to cigarette smoke (CS). The expression of microRNA-218-5p was detected by qRT-PCR in all the subjects and mice. The serum level of IL-18 and TGF-β1 was also detected via ELISA kit. To investigate the effects of miR-218-5p, 10 mg/kg of miR-218-5p inhibitor (miR-218-5p antagonist), a scrambled control or PBS (solvent) was intranasally administered on the first and the fourth exposure day, before the start of CS exposure.

RESULTS

The results showed that miR-218-5p was significantly down-regulated in patients with COPD, compared to normal subjects. There was a negative correlation between the plasma miR-218-5p level and the duration of disease since diagnosis in COPD ex-smokers. CS-induced COPD mice experiments with a miR-218-5p inhibitor demonstrated a protective role of miR-218-5p in cigarette smoke-induced inflammation and COPD.

CONCLUSIONS

These findings supported that miR-218-5p may, therefore, play an important role in the pathogenesis of COPD.

IL-33 induced inflammation exacerbated the development of chronic obstructive pulmonary disease through oxidative stress

OBJECTIVE

We aimed at exploring the role of IL-33 in mouse chronic obstructive pulmonary disease and its potential molecular mechanism.

MATERIALS AND METHODS

The chronic obstructive pulmonary disease (COPD) mice model was established by cigarette smoking (CS). COPD mice were randomly assigned into PBS group and IL-33 antibody group. The peripheral blood and lung tissues of mice from two groups were collected for the following experiments. Pathological changes of the lung tissues in both groups were analyzed by hematoxylin and eosin (HE) staining. IL-33 positive cells in lung tissues were detected by immunohistochemistry. Then, the mRNA and protein levels of IL-33, sST2, ERK and TNF-α in the mice peripheral blood of the two groups were accessed by Real-time polymerase chain reaction (RT-PCR) and Western blot. Finally, the indicators related to oxidative stress, including superoxide dismutase (SOD), malondialdehyde (MDA) and reactive oxygen species (ROS) in the mice serum of two groups were measured.

RESULTS

After successful construction of COPD mouse model by CS, HE staining illustrated that the structure of airway wall of lung tissue in mice from PBS group was irregular. The ciliated columnar epithelium presented significant degeneration, necrosis and shedding. A large amount of inflammation cell infiltration was observed in vascular tissues. The alveolar epithelial structure was severely damaged and alveolar septum was narrowed and ruptured. Adjacent alveoli were found to be fused into larger cysts. The above pathological changes were relatively better in mice from IL-33 antibody group. Immunohistochemical results demonstrated that IL-33 was remarkably deposited in the lung tissue of PBS group. The mRNA and protein levels of IL-33, sST2, ERK and TNF-α in peripheral blood of PBS group were much higher than those of IL-33 antibody group. At the same time, SOD level in PBS group decreased, while MDA level and ROS production increased.

CONCLUSIONS

IL-33 aggravates lung injury in COPD mice by increasing inflammation response and oxidative stress, which may serve as a target for predicting and treating COPD.

Investigations of Anisotropic Flow Using Multiparticle Azimuthal Correlations in pp, p-Pb, Xe-Xe, and Pb-Pb Collisions at the LHC

Measurements of anisotropic flow coefficients (v_{n}) and their cross-correlations using two- and multiparticle cumulant methods are reported in collisions of pp at sqrt[s]=13  TeV, p-Pb at a center-of-mass energy per nucleon pair sqrt[s_{NN}]=5.02  TeV, Xe-Xe at sqrt[s_{NN}]=5.44  TeV, and Pb-Pb at sqrt[s_{NN}]=5.02  TeV recorded with the ALICE detector. The multiplicity dependence of v_{n} is studied in a very wide range from 20 to 3000 particles produced in the midrapidity region |η|<0.8 for the transverse momentum range 0.2<p_{T}<3.0  GeV/c. An ordering of the coefficients v_{2}>v_{3}>v_{4} is found in pp and p-Pb collisions, similar to that seen in large collision systems, while a weak v_{2} multiplicity dependence is observed relative to nucleus-nucleus collisions in the same multiplicity range. Using a novel subevent method, v_{2} measured with four-particle cumulants is found to be compatible with that from six-particle cumulants in pp and p-Pb collisions. The magnitude of the correlation between v_{n}^{2} and v_{m}^{2}, evaluated with the symmetric cumulants SC(m,n) is observed to be positive at all multiplicities for v_{2} and v_{4}, while for v_{2} and v_{3} it is negative and changes sign for multiplicities below 100, which may indicate a different v_{n} fluctuation pattern in this multiplicity range. The observed long-range multiparticle azimuthal correlations in high multiplicity pp and p-Pb collisions can neither be described by pythia 8 nor by impact-parameter-Glasma, music, and ultrarelativistic quantum molecular dynamics model calculations, and hence, provide new insights into the understanding of collective effects in small collision systems.

P6592Novel heart-specific LncRNAs identified by deep sequencing contribute to pathogenesis in arrhythmogenic cardiomyopathy

Background

Arrhythmogenic Cardiomyopathy (AC) is one of main causes of sudden cardiac death in young people with limited understanding of molecular mechanism. LncRNAs are emerging as important regulators of cardiovascular diseases, but their roles in AC remain elusive.

Purpose

This study is to identify novel lncRNAs in AC genome wide and investigate their functions.

Methods and results

Extremely deep RNA-seq was performed for AC right ventricles (RVs, n=9) and left ventricles (LVs, n=6), normal RVs (n=5) and LVs (n=6), and dilated cardiomyopathy (DCM) RVs (n=4). Novel lncRNAs were accurately identified with epigenetic annotations. In comparison with normal and DCM, 1,925 novel lncRNAs transcripts specifically upregulated in AC RVs were identified. Most of AC-specific lncRNAs were highly expressed in heart, located in distal regions (>3 kb) from coding gene and marked by H3K4me1 or H3K27ac, indicating that these lncRNAs might act as cis-elements to regulate gene expression. Enrichment analysis revealed that AC-specific lncRNAs were associated with AC phenotypes like RV enlargement and dysfunction. Interestingly, their potential target genes were significantly enriched in lipid metabolism and calcium signaling pathways. In-vitro experiments demonstrated that LncRNA AC1, a novel AC-specific lncRNA, was significantly positively correlated with adipogenic genes expression. And overexpression of LncRNA AC1 promoted adipogenic genes expression and droplet deposition in human derived iPSC-CM and cardiac fibroblast.

ESC-AC lncRNA study abstract

Conclusion

We identified novel AC-specific lncRNAs related to adipogenesis and validated them in-vitro. Our findings also provide fundamental resource for the potential development of basic translation study for AC.

Acknowledgement/Funding

This study was supported by CAMS Innovation Fund for Medical Sciences (2016-I2M-1-015)

Verification and Validation of SuperMC3.2 Using VENUS-3 Benchmark Experiments

Methodological processes for nuclear power plant (NPP) pressure vessels' (PV) neutron fluence rate determination take the form of experimental measurement or theoretical calculations. However, the process of experimental measurement takes longer periods, as it requires the incorporation of surveillance capsules into a PV system undergoing normal NPP operation. Therefore, strong reliance on computation and modeling of radiation-induced degradation is given much attention. In this work, the VENUS-3 benchmark has been analyzed using SuperMC code, with the intention of validating SuperMC for accurate reactor neutronics; dosimetry response calculations for in-core/ex-core structural components, particularly with respect to the VENUS-3 configuration type pressurized water reactors (PWRs). In this work, complete three-dimensional (3D) geometry including the source modeling for VENUS-3 facility has been developed with SuperMC. Neutron transport and calculations of equivalent fission flux for the experimental target quantities, 115In (n, n′), 58Ni (n, p), and 27Al (n, α), are also achieved. The calculation results show good agreement with the experimental measurement. The greater majority of the calculated values (C/E) were within the required accuracy of ±10% for reactor components' dosimetry calculations. Most of the calculated values were contained within 5% deviation from the experimental data. Additional calculations and detailed analysis for fast neutron flux distribution and iron displacement per atom rate (dpa/s), including the characteristic effect of partial length shielded assembly (PLSA) on VENUS-3 core barrel, are also discussed. It is therefore evidenced that the effectiveness of SuperMC code for in-core/ex-core reactor neutronics computations has been convincingly demonstrated through the VENUS-3 benchmark testing.

P5350Atrial fibrillation prediction using P wave signal-averaged ECG in patients with embolic stroke of undetermined source

Background

Approximately 10–25% of ischemic strokes are of unknown origin. Determining their potential association with subclinical atrial fibrillation (SCAF) is important for proper secondary prevention. We investigated whether SCAF can be predicted by assessing the atrial substrate with signal-averaged electrocardiography (SAECG).

Methods

Between April 2015 and February 2018, we recruited 125 consecutive patients with embolic stroke of undetermined source (ESUS) and 125 patients with paroxysmal atrial fibrillation (AF) patients as control. All participants underwent P wave SAECG at baseline and ESUS patients were followed up with ECG and Holter ECG, at baseline, 3, 6, and 12 months after discharge, and every 12 months thereafter.

Results

In the ESUS group (69 males, 68.4±12.1 years), 32 (25.6%) patients were diagnosed with SCAF during follow-up. There were no significant differences between both groups in terms of P wave duration [PWD] (ESUS vs. AF, P=0.321). PWD demonstrated a significant predictive efficacy for SCAF detection during follow-up (C-index of standard PWD=0.657, 95% confidence interval (CI) 0.552–0.761, P=0.008).

Stroke recurrence occurred in 22 patients (17.6%) and was significantly associated with PWD but not SCAF (odds ratio 2.756, 95% CI 1.061–7.161, P=0.037).

Conclusion

PWD, an ECG biomarker associated with atrial substrate directly contributes to AF and ESUS, is useful for predicting SCAF. The potential for using this simple ECG biomarker for screening for SCAF amongst ESUS patients merits further exploration.

First Observation of an Attractive Interaction between a Proton and a Cascade Baryon

This Letter presents the first experimental observation of the attractive strong interaction between a proton and a multistrange baryon (hyperon) Ξ^{-}. The result is extracted from two-particle correlations of combined p-Ξ^{-}⊕p[over ¯]-Ξ[over ¯]^{+} pairs measured in p-Pb collisions at sqrt[s_{NN}]=5.02  TeV at the LHC with ALICE. The measured correlation function is compared with the prediction obtained assuming only an attractive Coulomb interaction and a standard deviation in the range [3.6, 5.3] is found. Since the measured p-Ξ^{-}⊕p[over ¯]-Ξ[over ¯]^{+} correlation is significantly enhanced with respect to the Coulomb prediction, the presence of an additional, strong, attractive interaction is evident. The data are compatible with recent lattice calculations by the HAL-QCD Collaboration, with a standard deviation in the range [1.8, 3.7]. The lattice potential predicts a shallow repulsive Ξ^{-} interaction within pure neutron matter and this implies stiffer equations of state for neutron-rich matter including hyperons. Implications of the strong interaction for the modeling of neutron stars are discussed.

[Study on the current status of postgraduates training in public health and preventive medicine in China in 2016]

To investigate the current status of postgraduates training in public health and preventive medicine in China. In this study, a questionnaire survey was conducted among directors of enrollment and teaching in 22 universities with postgraduate admission qualifications in corresponding disciplines nationwide. In 2016, full-time postgraduates were mainly academic masters. In addition to the graduate entrance examination, the common enrollment mode in colleges was to enroll a high qualified student with recommendations from relevant experts or institutions and an exemption from entrance examination (20/22). The emphasis on training contents between academic and public health master was different. Currently, the scale of public health postgraduate enrollment in public health and preventive medicine in China is stable, and the training program is reasonable, but there is an issue of monotonous model and uneven distribution of enrollment.

[Investigation on the current status of the cultivation of the master of public health (MPH) in colleges in China]

In order to understand the status of the cultivation of the masters of public health (MPH) in colleges in China and improve the cultivation model, an electronic questionnaire survey were conducted among 22 schools of public health in colleges. The result showed that the size and the enrolment scale of Chinese MPH students were relatively small, and the training objectives were still unclear. There was no obvious difference between the curriculum setting for MPH and academic master degree. The practical skill-oriented courses and emergency response ability of public health practice were insufficient. The cultivation model of MPH should be improved in future.

[Analysis of the contradiction between the supply and demand of Chinese graduate students' emergency professional ability in public health and preventive medicine in China]

In order to underst and the status of health emergency personnel training development and raising coping measures, electronic questionnaire surveys were conducted among 22 colleges and universities in different region of China. The result showed that colleges universities in China invested less in the training of emergency personnel. It is different and emphasized particularly for the cultivation of emergency professional ability among different types of public health students. Universities and employer hold relative evaluation of students' emergency professional ability with distinct regional differences.

The role of HLA variation in lymphoma aetiology and survival

Epidemiologic and laboratory evidence has consistently supported a strong inflammatory and immune component for lymphoma aetiology. These studies have consistently implicated variation in the immune gene, human leucocyte antigen (HLA), to be associated with lymphoma risk. In this review, we summarize the historical and recent evidence of HLA in both lymphoma aetiology and survival. The recent momentum in uncovering HLA associations has been propelled by the conduct of genome-wide association studies (GWAS), which has permitted the evaluation of imputed HLA alleles in much larger sample sizes than historically feasible with allelotyping studies. Based on the culmination of smaller HLA typing studies and larger GWAS, we now recognize several HLA associations with Hodgkin (HL) and non-Hodgkin lymphomas (NHLs) and their subtypes. Although other genetic variants have also been implicated with lymphoma risk, it is notable that HLA associations have been reported in every NHL and HL subtype evaluated to date. Both HLA class I and class II alleles have been linked with NHL and HL risk. It is notable that the associations identified are largely specific to each lymphoma subtype. However, pleiotropic HLA associations have also been observed. For example, rs10484561, which is in linkage disequilibrium with HLA-DRB1*01:01˜DQA1*01:01˜DQB1*05:01, has been implicated in increased FL and DLBCL risk. Opposing HLA associations across subtypes have also been reported, such as for HLA-A*01:01 which is associated with increased risk of EBV-positive cHL but decreased risk of EBV-negative cHL and chronic lymphocytic leukaemia/small cell lymphoma. Due to extensive linkage disequilibrium and allele/haplotypic variation across race/ethnicities, identification of causal alleles/haplotypes remains challenging. Follow-up functional studies are needed to identify the specific immunological pathways responsible in the multifactorial aetiology of HL and NHL. Correlative studies linking HLA alleles with known molecular subtypes and HLA expression in the tumours are also needed. Finally, additional association studies investigating HLA diversity and lymphoma survival are also required to replicate initial associations reported to date.

[Three-dimensional finite element analysis of cantilever fixed bridge supported by implants with mandibular central incisor]

Objective: To investigate effect of the contact surface between the bridge and the adjacent teeth on the stress distribution of the implant and bone tissue and the displacement of the prosthesis in the cantilever fixed implant bridge restoring missing mandibular central incisors. Methods: Two-dimensional images of the mandible and dentition in healthy adults were obtained using CT data. A three-dimensional finite element model of cantilever fixed bridge supported by implants with mandibular central incisor was established by computer reconstruction technique.The contact surface between the bridge and the adjacent natural tooth was designed as "oval" and "trapezoid". The "trapezoid" has a slightly smaller median diameter on the labial side and a slightly larger medial diameter on the lingual side. Loading of 120 N was applied on the tangential margin of the middle line of the long axis of the bridge 41. The direction was set at 0°, which was parallel to the long axis of the tooth and downward. The buccal to lingual and downward angles were 30°, 45° and 60°, respectively, perpendicular to the long axis of the tooth and 90° to the lingual side.The stress distribution of the implant and surrounding bone tissue and the displacement of the prosthesis were compared between the two models. Results: Under axial and buccolingual loading, the maximum equivalent stress peak in the implant and surrounding bone tissue in the cantilever with trapezoidal contact surface design and the maximum displacement of the prosthesis were lower. Moreover, the distribution of stress was more balanced and the concentration range of stress was smaller. With the loading angle increasing, this trend was more obvious. When loading angle increased to 90°, the maximum equivalent stress and the maximum displacement of the elliptic contact surface model implant and surrounding bone tissue were 196 and 101 MPa and 0.196 mm, respectively, while the trapezoidal contact surface model were 157 and 72 MPa and 0.164 mm, respectively. Conclusions: The trapezoidal contact surface of the bridge and the adjacent teeth in the cantilever fixed bridge supported by implants with mandibular central incisor is beneficial to reduce the impact of the leverage on the implant and surrounding bone tissue.

Systematic identification of lncRNAs and circRNAs-associated ceRNA networks in human lumbar disc degeneration

Lumbar disc degeneration (LDD) is a common cause of low back and neck pain. The molecular mechanisms underlying LDD, however, are unclear. Noncoding RNAs have been reported to participate in human diseases. We investigated a series of public datasets (GSE67566, GSE56081 and GSE63492) and identified 568 mRNAs, 55 microRNAs (miRNAs), 765 long noncoding RNAs (lncRNAs), and 586 circular RNAs (circRNAs) that were expressed differently in LDD than in normal discs. We constructed lncRNAs and circRNAs regulated competing endogenous RNAs (ceRNA) networks in LDD. Four lncRNAs, DANCR, CASK-AS1, SCARNA2, and LINC00638), and three circRNAs, hsa_circ_0005139, hsa_circ_0037858, and hsa_circ_0087890, were identified as key regulators of LDD progression. We found that hsa-miR-486-5p regulated the crosstalk among circRNA hsa_circ_0000189, lncRNA DANCR and 6 mRNAs, PYCR2, TOB1, ARHGAP5, RBPJ, CD247, SLC34A1. Gene ontology (GO) analysis demonstrated that these differently expressed lncRNAs and circRNAs were involved in cellular component organization or biogenesis, gene expression and negative regulation of metabolic processes. Our findings provide useful information for exploring new mechanisms for LDD and candidates for therapeutic targets.

Hormone replacement therapies, oral contraceptives, reproductive factors and colorectal adenoma risk: a systematic review and dose-response meta-analysis of observational studies

AIM

The association between the use of oral contraceptives and hormone replacement therapy (HRT) or other reproductive factors and the risk of colorectal adenoma (CRA) remains controversial. Our study aimed to review the evidence by conducting a dose-response meta-analysis to investigate this association.

METHODS

We searched PubMed and Embase databases for relevant studies published until May 2017. Traditional and dose-response meta-analyses were conducted. Sensitivity analysis was performed to evaluate the robustness of the results. Cumulative meta-analysis was used to assess the risk of different oral contraceptive formulations or generations.

RESULTS

A total of 19 observational studies, with 21 923 CRA cases and 1 030 711 participants, were included in the meta-analysis. Ever HRT use showed a potential inverse association with CRA risk [relative risk (RR) 0.83, 95% CI 0.70-1.00]. The dose-response meta-analysis further demonstrated that HRT use could reduce CRA risk. Compared with no HRT use, the predicted RRs were 0.82 (95% CI 0.67-0.99), 0.76 (95% CI 0.59-0.98) and 0.77 (95% CI 0.62-0.96) for 3, 6 and 9 years of HRT use, respectively. All other factors were not statistically significantly associated with CRA risk.

CONCLUSIONS

This study indicated that only HRT use might reduce the risk of developing CRA. Any advice regarding HRT use to prevent CRA should be tailored to the individual risks and potential benefits. Large, well-designed prospective studies with long-term follow-up are required to further clarify the aetiology of CRA.

[Role of erythroblast-like Ter cells in the pathogenesis of collagen-induced arthritis]

OBJECTIVE

To explore the role of Ter cells in the development of the collagen-induced arthritis (CIA), we detected their quantity changes in the spleen of different stages of CIA mice and analyzed the correlation between Ter cells and the joint scores, and we also analyzed the correlation between Ter cells and the frequencies of T and B cell subsets, so as to further understand the pathogenesis of rheumatoid arthritis.

METHODS

The six to eight weeks DBA/1 mice were used to prepare CIA model. After the second immunization, we began to evaluate the joint score. According to the time of CIA onset and the joint score, the CIA mice were divided into three stages: early, peak and late stages. According to the final joint score, the CIA mice at the peak stage were subdivided into the high score group (score>8) and the low score group (score≤8). The frequencies of Ter cells in the spleen of the naïve mice and the CIA mice at various stages and the frequencies of T and B cell subsets in the spleen of the CIA mice at the peak stage were detected by flow cytometry, then we carried on the correlation analysis.

RESULTS

The frequencies of Ter cells in the spleen of the CIA mice was significantly higher than those of the naïve mice (8.522%±2.645% vs. 1.937%±0.725%, P<0.01), the frequencies of Ter cells in the spleen of the high score group mice was significantly lower than those of the low score group (6.217%±0.841% vs. 10.827%±0.917%, P<0.01). The frequencies of Th1 cells in the spleen of the high score group mice was significantly higher than those of the low score group mice (1.337%±0.110% vs. 0.727%±0.223%, P<0.05). The frequencies of Th17 cells in the spleen of the high score group mice was higher than those of the low score group mice (0.750%±0.171% vs. 0.477%±0.051%, P=0.099). The frequencies of germinal center B cells in the spleen of the high score group mice was significantly higher than those of the low score group mice (1.243%±0.057% vs. 1.097%±0.015%, P<0.05). Correlation analysis results showed that the frequencies of Ter cells in the spleen of the CIA mice at the peak stage was strongly negatively correlated with the frequencies of CD4+ T, Th1, Th17, and germinal center B cells, and was strongly positively correlated with the frequencies of B10 cells, indicating that these cells might have a protective effect in CIA. Studies on dynamic changes showed that the frequencies of Ter cells in the spleen of the CIA mice at the late stage was significantly lower than those at the peak stage (0.917%±0.588% vs. 8.522%±2.645%, P<0.001), suggesting the protective effect of these cells in arthritis.

CONCLUSION

Ter cells were significantly increased in the spleen of the CIA mice at peak stage, and were negatively correlated with joint scores and pathogenic immune cells, and positively correlated with protective immune cells. Ter cells were significantly decreased in the spleen of the CIA mice at the late stage. What we mentioned above suggests that Ter cells might be involved in the progression of rheumatoid arthritis as an immunomodulatory cell,but further in vivo and in vitro experiments are needed to verify its specific effects and mechanism.

[The protective effect of pigment epithelial-derived factor modified human umbilical cord mesenchymal stem cells on rats with diabetic retinopathy]

Objective: To investigate the effect of pigment epithelial-derived factor (PEDF) gene-modified human umbilical cord mesenchymal stem cells (MSC) on rats with diabetic retinopathy (DR). Methods: Experimental study. Human umbilical cord MSC were transfected by lentivirus packaging PEDF-MSC-green fluorescent protein (GFP) and GFP-MSC plasmid vectors, and the expression of PEDF and vascular endothelial growth factor (VEGF) was measured in the cell culture medium. Fifty adult male Sprague-Dawley rats were randomly divided into five groups: normal control group (group A), DR control group (group B), phosphate-buffered saline (PBS) treated group (group C), GFP-MSC treated group (group D) and PEDF-MSC-GFP treated group (group E), with 10 rats in each group. Streptozotocin was intraperitoneally injected to make early DR models. After four-month intervention, groups D and E were given intravitreal injection of GFP-MSC and PEDF-MSC-GFP; group C was given intravitreal injection of phosphate-buffered saline; groups A and B did not receive special treatment. The changes of retina in different groups were detected by hematoxylin and eosin staining, and the thickness of inner plexiform layer, inner nuclear layer and outer nuclear layer was measured by computer-based image analytical system. Immunohistochemistry was applied to observe PEDF and VEGF. Real-time quantitative polymerase chain reaction was used to detect the expression of PEDF and VEGF mRNA. Results: The expression of CD105, CD73 and CD90 was positive, while the expression of CD34, CD45, CD11b, CD19 and HLA-DR was negative. ELISA results showed that after transfection PEDF protein expression in the supernatant of PEDF-MSC (84.09±7.07) μg/L was higher than the control group (9.03±0.14) μg/L (P<0.05). At 2 weeks after intravitreal injection, green fluorescence was observed in the rat vitreous of groups D and E under a fluorescence microscope; no obvious green fluorescence was found in the retina. After 2 months of intravitreal injection, the thickness of inner plexiform layer in group E was significantly decreased; the thickness of inner nuclear layer and outer nuclear layer was higher (P<0.05). Immunohistochemical staining showed that 2 months after intravitreal treatment, the average optical density values of PEDF were improved, but the average optical density values of VEGF were decreased in group E (P<0.05). Real-time polymerase chain reaction showed that 2 months after treatment, the expression level of PEDF mRNA in group E was improved, but the expression level of VEGF mRNA was decreased (P<0.05). Conclusions: Intravitreal injection of PEDF-MSC could up-regulate the expression of PEDF and down-regulate the expression of VEGF in diabetic rats and may represent a novel candidate resource for cell therapy of DR nerve damage. (Chin J Ophthalmol, 2017, 53, 540-547).

Genetic influences on eight psychiatric disorders based on family data of 4 408 646 full and half-siblings, and genetic data of 333 748 cases and controls

BACKGROUND

Most studies underline the contribution of heritable factors for psychiatric disorders. However, heritability estimates depend on the population under study, diagnostic instruments, and study designs that each has its inherent assumptions, strengths, and biases. We aim to test the homogeneity in heritability estimates between two powerful, and state of the art study designs for eight psychiatric disorders.

METHODS

We assessed heritability based on data of Swedish siblings (N = 4 408 646 full and maternal half-siblings), and based on summary data of eight samples with measured genotypes (N = 125 533 cases and 208 215 controls). All data were based on standard diagnostic criteria. Eight psychiatric disorders were studied: (1) alcohol dependence (AD), (2) anorexia nervosa, (3) attention deficit/hyperactivity disorder (ADHD), (4) autism spectrum disorder, (5) bipolar disorder, (6) major depressive disorder, (7) obsessive-compulsive disorder (OCD), and (8) schizophrenia.

RESULTS

Heritability estimates from sibling data varied from 0.30 for Major Depression to 0.80 for ADHD. The estimates based on the measured genotypes were lower, ranging from 0.10 for AD to 0.28 for OCD, but were significant, and correlated positively (0.19) with national sibling-based estimates. When removing OCD from the data the correlation increased to 0.50.

CONCLUSIONS

Given the unique character of each study design, the convergent findings for these eight psychiatric conditions suggest that heritability estimates are robust across different methods. The findings also highlight large differences in genetic and environmental influences between psychiatric disorders, providing future directions for etiological psychiatric research.

[Investigation on the status of multidrug-resistant gram-negative bacteria induced by occupational exposure among medical staff in ICU]

Objective: To understand the natural carriage status of multidrug resistant gram-negative bacteria in ICU medical personmel and control growp of 69 hospitals in Tianjin. Methods: From April 2007 to October 2016, 2902 samples of nasal vestibule and hand swabs were collected from 1296 ICU medical personmel and 155 non medical personmel (control group) , and 14 kinds of antimicrobial agents were used to test the sensitivity of gram-negative bacilli. Results: 332 Gram-negative bacteria were isolated from medical personmel, of which 139 were multidrug resistant; 70 gram-negative bacteria were isolated from control group, and 20 of which were multidrug resistant. There was no significant difference (P>0.05) in the incidence of nasal vestibular colonization between medical personmel group (231/1296) and control group (32/155) . The control group (38/155) had a higher rate of hand bacteria carriage than medical staff group (101/1296) (P<0.01) . The proportion of multidrug resistant gram-negative bacteria was 28.57% (20/70) in control group, which was significantly lower than medical personmel group (41.87%, 139/332) (P<0.05) . Conclusion: For the nasal vestibule, the medical personnel and control guoup have the same gram-negative bacteria carrying rate, but the multidrug resistant bacteria isolation rate from the medical staff group are significantly higher which may due to vocational contamination of pathogen in ICU; while the gram-negative bacteria in the hands of the medical staff group are significantly lower than those of the control group, which might attribute to the difference of hand sanitation technique of two groups.