[Causes of death and influencing factors of atrial fibrillation patients undergoing anticoagulation therapy]

Objective: To investigate the causes of death and predictors in patients with nonvalvular atrial fibrillation (AF) undergoing anticoagulation therapy. Methods: Consecutive anticoagulated nonvalvular AF patients were recruited from the China Atrial Fibrillation Registry (China-AF) Study from August 2011 to December 2018. After exclusion of patients with hypertrophic cardiomyopathy, dilated cardiomyopathy, or loss of follow-up within 1 year, 2 248 patients were included in this analysis. Enrolled patients were followed up were followed up for 3 and 6 months, and then every 6 months. The primary endpoint was death, including cardiovascular death, non-cardiovascular death and undetermined death. The patients were divided into survival group and death group according to the survival status after follow-up. Clinical information such as age and sex was collected. Cox proportional hazards regression was performed to identify associated risk factors for all-cause mortality, and Fine-Gray competing risk model was used to identify associated risk factors for cardiovascular mortality. Results: A total of 2 248 patients with atrial fibrillation receiving anticoagulant therapy died over a mean follow-up of (42±24) months, mean age was (67±10) years old and 41.1% (923/2 248) patients were female. The mortality rate was 2.8 deaths per 100 patient-years. The most common cause of death was cardiovascular deaths, accounted for 55.0% (120/218). Worsening heart failure was the most common cause of cardiovascular deaths (18.3% (40/218)), followed by bleeding events (12.9% (28/218)) and ischemic stroke (8.7% (19/218)). Multivariate Cox regression analysis showed that age (HR = 1.05, 95%CI 1.04-1.07, P<0.001), anemia (HR = 1.81, 95%CI 1.02-3.18, P = 0.041), heart failure (HR=2.40, 95%CI 1.75-3.30, P<0.001), ischemic stroke/transient ischemic attack (TIA)(HR = 1.59, 95%CI 1.21-2.13, P = 0.001) and myocardial infarction (HR = 2.93, 95%CI 1.79-4.81, P<0.001) were independently associated with all-cause death. Fine-Gray competing risk model showed that age (HR=1.05, 95%CI 1.02-1.08, P<0.001), heart failure (HR=2.81, 95%CI 1.79-4.39, P<0.001), ischemic stroke/TIA (HR=1.50, 95%CI 1.02-2.22, P=0.041) and myocardial infarction (HR=3.31, 95%CI 1.72-6.37, P<0.001) were independently associated with cardiovascular death. Conclusions: In anticoagulated nonvalvular AF patients, ischemic stroke represents only a small subset of deaths, whereas worsening heart failure is the most common cause of cardiovascular deaths. Heart failure, ischemic stroke/TIA, and myocardial infarction are associated with increased mortality.

[Effects of protein disulfide isomerase on hyperglycemia and hypoxia/reoxygenation injury in H9c2 cardiomyocytes]

Objective: To explore the effect of protein disulfide isomerase (PDI) in diabetic ischemic heart disease. Methods: We established an in vitro model of high glucose and hypoxia/reoxygenation in H9c2 rat myocardial cells. Cultured cells were divided into four groups: Control, high glucose (HG), hypoxia/reoxygenation (H/R) and HG+H/R. Changes in PDI expression mediated by PDI adenovirus(Ad-PDI) infection and siRNA(PDI-siRNA) transfection in myocardial cells were observed by inverted fluorescence microscopy. We also measured lactate dehydrogenase(LDH) activity and malondialdehyde(MDA) and high molecular weight(HMW)-APN concentrations. PDI, APN, cleaved caspase-3, and glucose regulated protein 78 (Grp78) protein expression were detected. Results: PDI expression was significantly decreased in the HG, H/R and HG+H/R groups compared to the Control group; however, LDH activity[(179.7±10.4) U/L、(218.4±18.4) U/L、(328.2±5.3) U/L vs (91.0±11.0) U/L], MDA concentration[(7.0±0.4) μmol/L、(10.0±1.0) μmol/L、(11.7±1.0) μmol/L vs (4.2±1.8) μmol/L], cleaved caspase-3, and Grp78 expression were increased. Interestingly, APN and HMW-APN expression were decreased [(2.01±0.21) μg/L、(1.64±0.27) μg/L、(1.20±0.14) μg/L vs (2.62±0.12) μg/L, all P<0.05]. Over expression of PDI attenuated high glucose and hypoxia/reoxygenation induced apoptosis and oxidative stress in H9c2 cardiomyocytes(all P<0.05), and simultaneously increased APN and HMW-APN expression [(2.86±0.03) μg/L vs (3.03±0.10) μg/L、(2.06±0.05) μg/L vs (2.31±0.06) μg/L、(1.83±0.07) μg/L vs (1.96±0.11) μg/L、(1.20±0.06) μg/L vs (1.39±0.09) μg/L]. PDI-siRNA transfection increased LDH activity, MDA concentration, and cleaved caspase-3 and Grp78 expression, and decreased APN and HMW-APN expression [(0.75±0.09) μg/L vs (0.59±0.09) μg/L、(0.62±0.04) μg/L vs (0.53±0.05) μg/L、(0.55±0.14) μg/L vs (0.51±0.12) μg/L、(0.48±0.12) μg/L vs (0.35±0.08) μg/L] in response to different treatments in cultured H9c2 cardiomyocytes (all P<0.05). Conclusion: PDI may regulate the expression of APN and HMW-APN, and play an important role in the function of diabetic ischemia-reperfusion cardiomyocytes.

Diffusion MRI Microstructural Abnormalities at Term-Equivalent Age Are Associated with Neurodevelopmental Outcomes at 3 Years of Age in Very Preterm Infants

BACKGROUND AND PURPOSE

Microstructural white matter abnormalities on DTI using Tract-Based Spatial Statistics at term-equivalent age are associated with cognitive and motor outcomes at 2 years of age or younger. However, neurodevelopmental tests administered at such early time points are insufficiently predictive of mild-moderate motor and cognitive impairment at school age. Our objective was to evaluate the microstructural antecedents of cognitive and motor outcomes at 3 years' corrected age in a cohort of very preterm infants.

MATERIALS AND METHODS

We prospectively recruited 101 very preterm infants (<32 weeks' gestational age) and performed DTI at term-equivalent age. The Differential Ability Scales, 2nd ed, Verbal and Nonverbal subtests, and the Bayley Scales of Infant and Toddler Development, 3rd ed, Motor subtest, were administered at 3 years of age. We correlated DTI metrics from Tract-Based Spatial Statistics with the Bayley Scales of Infant and Toddler Development, 3rd ed, and the Differential Ability Scales, 2nd ed, scores with correction for multiple comparisons.

RESULTS

Of the 101 subjects, 84 had high-quality DTI data, and of these, 69 returned for developmental testing (82%). Their mean (SD) gestational age was 28.4 (2.5) weeks, and birth weight was 1121.4 (394.1) g. DTI metrics were significantly associated with Nonverbal Ability in the corpus callosum, posterior thalamic radiations, fornix, and inferior longitudinal fasciculus and with Motor scores in the corpus callosum, internal and external capsules, posterior thalamic radiations, superior and inferior longitudinal fasciculi, cerebral peduncles, and corticospinal tracts.

CONCLUSIONS

We identified widespread microstructural white matter abnormalities in very preterm infants at term that were significantly associated with cognitive and motor development at 3 years' corrected age.

Toroidal soft x-ray array on the EXL-50 spherical tokamak

A toroidal soft x-ray array system for spectrum and intensity measurements on the EXL-50 spherical tokamak is described. Silicon drift detectors and digital multichannel analyzers are adopted for all 21 channels of the array, and an average energy resolution of 147 eV at 5.89 keV has been achieved at count rates over 500 kcps. In total, 20 channels of the array are symmetrically observed in both co- and counter-current directions on the EXL-50 mid-plane with a spatial resolution of around 10 cm, and the remaining one serves as a background reference channel. Tungsten emissions from tungsten coating of the limiters on the central post are observed. The influence of hard x rays on measured soft x-ray spectra and system operation is discussed.

[Amiodarone promotes heat-induced apoptosis, inflammation and oxidative stress in mouse HL1 atrial myocytes]

OBJECTIVE

To investigate the injury types of atrial myocytes induced by heat exposure and the effect of amiodarone on heat-induced injuries in atrial myocytes.

OBJECTIVE

The optimal temperature for heat exposure and optimal concentration of amiodarone were determined by measuring the cell viability exposed to different temperatures and different concentrations of amiodarone. Heat exposure of HL1 atrial myocytes was conducted using a water bath, and the effect of amiodarone on cell viability was assessed with MTS method; cell apoptosis was detected using flow cytometry, and the levels of IL-1β, IL-6, TNF-α, SOD and MDA were detected with enzyme-linked immunosorbent assay (ELISA).

OBJECTIVE

Compared with the blank control cells, the cells exposed to a temperature of 52 ℃ showed a significantly decreased survival rate and a lowered SOD activity (P < 0.001) with increased IL-1β and MDA levels (P < 0.01) and markedly increased apoptosis rate and IL-6 level (P < 0.001). Compared with the heat exposure group, amiodarone resulted in significantly decreased survival rate of the atrial myocytes (P < 0.01), obviously decreased SOD activity (P < 0.05), and increased cell apoptosis rate (P < 0.05) and IL-1β, IL-6, MDA and TNF-α levels (P < 0.01 or 0.001).

OBJECTIVE

Heat exposure induces apoptosis, inflammation and oxidative stress in mouse HL1 atrial myocytes, and amiodarone can enhance the effects of heat exposure to aggravate the cell injuries.

Development and preliminary test of a space-resolved vacuum-ultraviolet spectroscopy in EAST

The impurity radiation from the divertor region of the EAST tokamak is dominantly in the wavelength range of vacuum ultraviolet (VUV) due to the elevated edge electron temperature. A space-resolved VUV spectroscopy is developed to measure impurity radiation in the divertor region. An eagle-type VUV spectrometer with a focal length of 1 m is adopted in this system, equipped with a spherical grating and a charged-coupled device (CCD) detector. The performance of the VUV spectrometer is preliminarily tested on a synchrotron radiation facility. The wavelength calibration is conducted near 65 nm. It is found that the wavelength range observed by the CCD detector is about 11.07 nm around the central wavelength of about 65 nm. With a linear dispersion of 0.0053 nm/pixel, it is possible to measure the ion temperature lower than 20 eV at the edge region by analyzing the Doppler broadening of a carbon line. These test results show that the performance of the VUV spectrometer is capable of measuring divertor radiation and analyzing the ion temperature of edge impurity ions.

[CD44 regulates biological behavior and Ras signaling pathway in nasopharyngeal carcinoma stem cells]

Objective: To study the biological behavior of nasopharyngeal carcinoma stem cells and to explore the activation of Ras signaling pathway regulated by CD44. Methods: CNE2-SC and 5-8F-SC were nasopharyngeal carcinoma stem cells and obtained by serum-free suspension culture. Cell counting kit-8 (CCK-8) assay, colony formation assay, Transwell migration assay, cell adhesion array were used to investigate the growth, proliferation, migration and adhesion of nasopharyngeal carcinoma stem cells. Western blot test was used to detect the expressions of Ras signaling pathway related proteins and siRNA-mediated interference was used to determine the activation of Ras signaling pathway regulated by CD44. Results: The growth rates of CNE2-SC and 5-8F-SC cells were significantly lower than those of nasopharyngeal carcinoma cells at 24, 48 and 72 hours after inoculation (P<0.05). After 14 days of implantation, the colony formation rates of CNE2-SC (44.5±1.9)% and 5-8F-SC (47.4±1.8)% were higher than those of CNE2 (34.9±1.5)% and 5-8F (37.2±1.7)%, respectively(P<0.01). The migration cell number of CNE2-SC was (87.6±7.8), 3.97 times higher than that of CNE2 (P<0.01). The migration cell number of 5-8F-SC was (67.2±5.7), 3.07 times higher than 5-8F (P<0.01). The adhesion rates of CNE2-SC and CNE2 cells were (42.1±7.6)% and (8.9±2.0)%, respectively at 3 hours after inoculation and were (82.4±5.0)% and (12.1±2.2)% at 6 hours after inoculation, respectively. The adhesion rate of CNE2-SC cells was higher than that of CNE2 cells (all P<0.01). The adhesion rates of 5-8F-SC and 5-8F cells were (53.6±6.1)% and (7.3±1.5)% at 3 hours after inoculation, and (90.7±3.6)% and (11.0±1.2)% at 6 hours after inoculation, respectively. The adhesion rate of 5-8F-SC cells was higher than that of 5-8F cells (P<0.01). The expression levels of CD44, Ras and N-cadherin were significantly higher, while phosphatase and tensin homolog deleted on chromosome 10 (PTEN), E-cadherin in nasopharyngeal carcinoma stem cells were lower than those of the nasopharyngeal carcinoma cells. Furthermore, the levels of phosphorylated mitogen extracellular kinase1/2 (p-MEK1/2) and phosphorylated extracellular signal-regulated protein kinase1/2 (p-ERK1/2)were significantly increased in nasopharyngeal carcinoma stem cells (P<0.01). Correlation analysis showed that the protein expression levels of CD44 was highly positively correlated with RAS in nasopharyngeal carcinoma stem cells(r=0.985, P=0.002; r=0.962, P=0.038). Deletion of CD44 in CNE2-SC decreased the expression levels of HER-2, Ras and p-ERK1/2, p-Akt and phosphorylated protein kinase C-δ(p-PKCδ) (P<0.01). Conclusions: Despite compare to the nasopharyngeal carcinoma cell, nasopharyngeal carcinoma stem cells grows at a relatively slow rate, the capacities of clone formation, migration, adhesion are promoted. This may be related to the CD44-regulated abnormal activation of Ras signaling pathway.

Observation of a quantum phase transition in the quantum Rabi model with a single trapped ion

Quantum phase transitions (QPTs) are usually associated with many-body systems in the thermodynamic limit when their ground states show abrupt changes at zero temperature with variation of a parameter in the Hamiltonian. Recently it has been realized that a QPT can also occur in a system composed of only a two-level atom and a single-mode bosonic field, described by the quantum Rabi model (QRM). Here we report an experimental demonstration of a QPT in the QRM using a ¹⁷¹Yb⁺ ion in a Paul trap. We measure the spin-up state population and the average phonon number of the ion as two order parameters and observe clear evidence of the phase transition via adiabatic tuning of the coupling between the ion and its spatial motion. An experimental probe of the phase transition in a fundamental quantum optics model without imposing the thermodynamic limit opens up a window for controlled study of QPTs and quantum critical phenomena.

Quantum phase transition occurs in many-body systems with abrupt changes in the ground state around zero temperature. Here the authors report signatures of quantum phase transition in single trapped ion that can be described using quantum Rabi model.

[Whole genomic copy number variation score: an indicator of potential diagnostic and prognostic value for lung adenocarcinoma]

Objective: To verify the value of whole genomic copy number variation (WGCNV) detection and scoring system in the diagnosis and prognosis of lung adenocarcinoma. Methods: Seventy-six lung adenocarcinoma specimens including ninety-one tumor samples and twenty adjacent non-tumor lung tissue samples were collected using Laser capture microdissection (LCM). Whole genomic amplification (WGA) was used to enrich DNA and construct a sequencing library for next generation sequencing (NGS). Changes of larger than 5Mb CNV in this study were analyzed and scored. The nuclear grading and score of tumor cells in the surgery and pleural effusion cytology of lung adenocarcinoma specimens were evaluated separately. For each case, we evaluated (1) nuclear size, (2) mitotic counts, (3) nuclear atypia, (4) atypical mitoses. The data of disease-free survive (DFS) and overall survive (OS) were collected for assessing the prognostic value of WGCNV score. Meanwhile, receiver operating characteristic (ROC) and area under curve (AUC) were used to define a cut-off value and evaluate the diagnostic significance in lung adenocarcinoma. Results: The WGCNV scores of twenty adjacent non-tumor lung tissue samples were treated as normal control and all of WGCNV scores of tumor samples range from 0 to 9.95, the median score was 2.7. The WGCNV scores were divided into three groups: low score group <1.74, medium score grade 1.74~4.23, high score grade >4.23. The WGCNV score was positively associated with the nuclear grade scoring (r=0.780 90, P<0.001). The result for evaluation of prognostic value of the WGCNV scores showed that comparing with low WGCNV score group, Hazard Ratio (HR) of medium score group was 4.11 (95%CI=0.72~23.57) and high score group was 2.07 (95%CI=0.30~14.12). These results suggested that the risks of the medium and high WGCNV score group elevated. According to the analysis results of ROC curve, when the cut off value was 0.01, the sensitivity and specificity for lung adenocarcinoma diagnosis were 97.8% and 95.0% respectively, the positive predictive value (PPV) and negative predictive value (NPV) were 99.0% and 90.1%, respectively, the AUC was 0.981. In the differentiation of adenocarcinoma in situ (AIS) and minimally invasive adenocarcinoma (MIA) group and invasive adenocarcinoma group, when the cut off value was 1.8, the sensitivity and specificity between the two groups were 78.1% and 94.4%, and the PPV and NPV were 98.0% and 52.0%, respectively, the AUC was 0.896. Conclusion: This study verifies that WGCNV scoring system has a potential diagnostic and prognostic value in lung adenocarcinoma.

[Total laparoscopic left colectomy intracorporeal anastomosis]

Laparoscopic left colectomy (LLC) has been widely performed for treating patients with left hemicolon cancer. For less invasion, totally laparoscopic left colectomy intracorporeal anastomosis (TLC/IA) has been increasingly attempted and proposed. Up to now, there is no standard for intracorporeal anastomosis. Authors list various types of intracorporeal anastomosis in terms of technical details and postoperative complications. According to the literatures, side to side anastomosis with linear laparoscopic stapler is the mainstream method. Surgeons should make flexible choices based on personal technical characteristics, colon conditions and objective economic conditions of patients. An individualized anastomosis method is acceptable.

Nanomicelles potentiate histone deacetylase inhibitor efficacy in vitro

Background

Amphiphilic block copolymers used as nanomicelle drug carriers can effectively overcome poor drug solubility and specificity issues. Hence, these platforms have a broad applicability in cancer treatment. In this study, Pluronic F127 was used to fabricate nanomicelles containing the histone deacetylase inhibitor SAHA, which has an epigenetic-driven anti-cancer effect in several tumor types. SAHA-loaded nanomicelles were prepared using a thin-film drying method and characterized for size, surface charge, drug content, and drug release properties. Loaded particles were tested for in vitro activity and their effect on cell cycle and markers of cancer progression.

Results

Following detailed particle characterization, cell proliferation experiments demonstrated that SAHA-loaded nanomicelles more effectively inhibited the growth of HeLa and MCF-7 cell lines compared with free drug formulations. The 30 nm SAHA containing nanoparticles were able to release up to 100% of the encapsulated drug over a 72 h time window. Moreover, gene and protein expression analyses suggested that their cytoreductive effect was achieved through the regulation of p21 and p53 expression. SAHA was also shown to up-regulate E-cadherin expression, potentially influencing tumor migration.

Conclusions

This study highlights the opportunity to exploit pluronic-based nanomicelles for the delivery of compounds that regulate epigenetic processes, thus inhibiting cancer development and progression.

Research progress on flat epithelium of the inner ear

Sensorineural hearing loss and vertigo, resulting from lesions in the sensory epithelium of the inner ear, have a high incidence worldwide. The sensory epithelium of the inner ear may exhibit extreme degeneration and is transformed to flat epithelium (FE) in humans and mice with profound sensorineural hearing loss and/or vertigo. Various factors, including ototoxic drugs, noise exposure, aging, and genetic defects, can induce FE. Both hair cells and supporting cells are severely damaged in FE, and the normal cytoarchitecture of the sensory epithelium is replaced by a monolayer of very thin, flat cells of irregular contour. The pathophysiologic mechanism of FE is unclear but involves robust cell division. The cellular origin of flat cells in FE is heterogeneous; they may be transformed from supporting cells that have lost some features of supporting cells (dedifferentiation) or may have migrated from the flanking region. The epithelial-mesenchymal transition may play an important role in this process. The treatment of FE is challenging given the severe degeneration and loss of both hair cells and supporting cells. Cochlear implant or vestibular prosthesis implantation, gene therapy, and stem cell therapy show promise for the treatment of FE, although many challenges remain to be overcome.

Improved reliability of mechanical behavior for a thermal tempered lithium disilicate glass-ceramic by regulating the cooling rate

Traditional thermal tempering was applied to lithium disilicate (LD) glass-ceramic specimens with bar-like and disc-like shapes. The tempering process was conducted by heating the specimens to a temperature below the dynamic softening point, and then rapid cooling in silicone oil with different temperatures ranging from room-temperature to 300 °C to regulate the cooling rate. Effect of the oil-temperature on mechanical behavior of the tempered glass-ceramic was investigated. For the tempering at the lower oil-temperature (e.g., at room-temperature), it was found that the LD glass-ceramic specimens with both the bar-like and disc-like shapes could be remarkably strengthen and toughen, however, obvious anisotropy in fracture toughness was displayed by the specimens with the bar-like shape. With increasing the oil-temperature up to 250 °C, the mechanical anisotropy of the bar-like specimens could be significantly alleviated without much loss of the strengthening effect. The results can provide references for improving reliability of mechanical behavior for the tempered LD glass-ceramic by regulating the cooling condition according to specimen geometry.

[Comparison of compliance and cost effectiveness between brand-name statins and generic statins]

Objective: To explore the differences of adherence, lipid reduction and cost-effectiveness between brand-name and generic statins. Methods: Statins prescription records of adult patients aged 18 years and above with the first prescription of statins between January 2015 to December 2017, were collected from community health information system of Chaoyang district of Beijing. Medication compliancy after first prescription was compared between group only taking brand-name statins (41 496 records) and group only taking generic statins (60 491 records). Lipid reduction and cost-effectiveness were also compared between two groups. Results: The medication compliancy of generic statins was worse than brand-name statins (28.2% vs. 36.2%, P<0.001). After excluding the influence of age, sex, history of hypertension and diabetes, and community correlation, generic atorvastatin (20 mg/day) showed better total cholesterol reduction effect [(0.86±0.07) mmol/L] and better low density lipid-cholesterol reduction effect [(0.67±0.07) mmol/L] one year later in 199 patients who consistently used it compared with brand-name atorvastatin at same dosage in 232 patients [(0.40±0.10) mmol/L and (0.42±0.08) mmol/L] (P<0.001, P=0.003). From the perspective of cost effectiveness, generic atorvastatin (20 mg/day) can reduce more than 50% of medical expenses at the same cholesterol reduction level. Conclusions: Generic statins might replace brand-name statins with similar treatment effect but lower medical expenses although its compliancy needs improvement. However, the data of adverse reactions of generic statins are lacking, it is necessary to carry out high-quality clinical research to improve and promote the development of generic statins.

Topologically protected beam splitters and logic gates based on two-dimensional silicon photonic crystal slabs

The beam splitters are essential optical components that are widely used in various optical instruments. The robustness of beam splitters is very necessary to all-optical networks. Here we report the design of the topologically protected beam splitter, whose splitting ratio can change flexibly to an arbitrary ratio, such as 50:50, 33:67, 25:75, based on the two-dimensional silicon photonic crystal slab. By using the 50:50 beam splitter, all major logic gates (OR, AND, NOT, XOR, NAND, XNOR, and NOR) are suitably designed with the linear interference approach. Additionally, these devices exhibit robustness even though some disorders exist. It is expected that these robust and compact devices are potentially applicable in optical computing and signal processing.

Impact of macrophage infiltration in patients with st-segment elevation myocardial infarction caused by plaque erosion: an in vivo optical coherence tomography study

Background

Chronic inflammatory infiltration is a common process for atherosclerosis development. However, autopsy studies reveal that incidence rate of inflammatory infiltrates are less abundant in plaque erosion compared with plaque rupture.

Purpose

Studies performed by optical coherence tomography (OCT) have allowed to establish the severity of plaque inflammation by assessing macrophage infiltration (MØI). In this study, we aimed at assessing the impaction of MØI in plaque erosion among patients with STEMI by using OCT.

Methods

A total of 1561 patients with ST-segment elevation myocardial infarctions (STEMI) who underwent OCT imaging were enrolled in this study. According to the exclusion criteria, 312 patients with STEMI exhibiting plaque erosion were classified as MØI or no MØI.

Results

163 (52.2%) patients had MØI at the site of plaque erosion, whereas 149 (47.8%) patients had no evidence of MØI and patients of MØI group were significantly older (P=0.015). The result of angiography showed the prevalence of multi-vessel disease appeared more frequency (P=0.021) and diameter stenosis% were higher (P=0.031) in MØI group. OCT results showed the minimum fibrous-cap thickness was thinner (P&lt;0.001) and the maximum lipid arc was larger (P=0.005) in MØI group. Some patients underwent imaging follow-up at 1 year. There was no significant difference in the culprit plaque morphology progress among two groups (Figure 1A-1D).

Conclusions

This study demonstrated that plaque inflammation can increase culprit lesion severity and plaque vulnerability in patients with STEMI caused by plaque erosion.

Figure 1

Funding Acknowledgement

Type of funding source: None

[Research on ZNA probe in the quantitative detection of chlamydia trachomatis nucleic acid]

Objective: To investigate the performance of ZNA(ZIP Nucleic Acid) probes and its application in the quantitative detection of Chlamydia trachomatis (CT)nucleic acid. Methods: Use CT positive plasmids to compare the PCR amplification curves of ZNA probes coupled with different ZIP numbers. Compare ZNA probes with other three sets of probes [namely, 29mer ordinary Taqman probes (long-DNA probe), 20mer ordinary Taqman probes (short-DNA probe) and MGB probes] for stability in PCR amplification curves and repeated freezing and thawing, and the difference in the detection rate of low-concentration plasmids. Use CT positive clinical samples to compare the difference in amplification curves between ZNA probes, long-DNA probe, short-DNA probe and MGB probes, and the detection rate of low-concentration samples. Results: (1) The Ct value and fluorescence value of the probes coupled with 5ZIP units are both better than those coupled with a smaller number of ZIPs. And the difference is biggest when compared with only coupled with 1 ZIP unit: Ct value increased by 1.34 (sensitivity increased by 2.37 times), and fluorescence value increased by 30%. (2) The amplification efficiency of the ZNA probe coupled with 5 ZIPs is 2.14-2.64 times that of the preferred ordinary Taqman probe and MGB probe, and the fluorescence value is 17%-90% higher. (3) The probe freeze-thaw stability results show that the ZNA probe has the best stability, and the lowest concentration of Ct value has the smallest deviation (CV% = 1.4), which is better than the other three sets of probes (CV%=1.7-3.7). (4) Using 35 CT positive clinical samples to compare the PCR amplification performance, compared with other three sets of probes, the amplification sensitivity of ZNA probes was increased by 1.60, 0.99 and 1.06 times respectively. And the results of the consistency analysis of the Ct value show that compared with short-DNA probe and MGB probes, ZNA probes have better detection performance for clinical samples. (5) Use low concentration plasmid template (200, 100, 50 and 10 copies/mL respectively) to compare the amplification sensitivity of the four sets of probes, the detection rate of ZNA probe is the best. Especially, at the lowest concentration 10 copies/mL, the detection rate of the other sets of probes is only 15%-20%, but the ZNA probe is still 30%. (6) In 20 clinical samples with different low concentrations (200, 150, 100, and 50 copies/mL), the detection rate of ZNA probes was the highest, which were 100%, 95%, 90%, and 70%, respectively. Conclusions: Through testing of the amplification efficiency, fluorescence value, freeze-thaw stability, the amplification performance of clinical samples and the detection sensitivity of low-concentration samples, ZNA probes coupled with 5 ZIPs show better performance than ordinary Taqman probes and MGB probes. As a new probe technology with flexible design and easy synthesis, ZNA probe can further improve detection sensitivity of low concentration samples in the field of gene expression.

[The thromboembolism risk of low-risk atrial fibrillation patients with different clinical characteristics]

Objective: This study explored the thromboembolism risk of low-risk atrial fibrillation (AF) patients (CHA₂DS₂-VASc score of 0 or 1 for male and 1 or 2 for female) with different clinical characteristics to provide the basis for anticoagulation decision-making in these patients. Methods: We prospectively enrolled consecutive 2 862 nonvalvular low-risk AF patients between August 2011 to December 2018 in China-AF (China Atrial Fibrillation Registry) Study, their CHA₂DS₂-VASc score was 0 or 1 for male and 1 or 2 for female. According to their age, sex, presence or absence of hypertension, diabetes mellitus, congestive heart failure, and vascular disease at the time of enrolling, patients were divided into CHA₂DS₂-VASc score 0 score group, 1 score group, and 2 score group. Patients were followed up every 6 months by outpatient clinic visit or telephone interview. The outcome was a thromboembolic event, including ischemic stroke and systemic embolism. Univariate Cox regression analysis was used to compare the thromboembolism risk between the patients with different risk factors and CHA₂DS₂-VASc score 0 group. Results: A total of 2 862 low-risk atrial fibrillation patients were enrolled in this study. 915 patients (32.0%) were female, and age was (55.0±10.7) years old. There were 933 patients (32.6%) in CHA₂DS₂-VASc score 0 group, 1 401 patients (49.0%) in score 1 group and 528 patients (18.5%) in score 2 group. During follow-up (median 1.5 years, 5 811.82 person-years), 33 cases of thromboembolic events were recorded, the annual rate of thromboembolism was 0.57% (95%CI 0.40%~0.80%). The number of thromboembolic events in patients with CHA₂DS₂-VASc score 0, 1 and 2 were 8, 11 and 14, respectively, and the annual thromboembolism event rates were 0.40% (95%CI 0.20%-0.81%), 0.39% (95%CI 0.22%-0.71%) and 1.34% (95%CI 0.80%-2.27%), respectively. The risk of thromboembolism of CHA₂DS₂-VASc score 2 group (HR=3.53, 95%CI 1.48-8.44; P=0.005), especially female patients aged 65-74 years in CHA₂DS₂-VASc score 2 group (HR=2.67, 95%CI 1.63-4.38; P<0.000) was significantly higher than that in patients of CHA₂DS₂-VASc score 0 group. Conclusion: Low-Risk Atrial Fibrillation patients with CHA₂DS₂-VASc score 2, especially female patients aged 65-74 years old with CHA₂DS₂-VASc score 2 are at higher risk of thromboembolism in low-risk AF patients. For such patients, intensified oral anticoagulant therapy might be helpful to reduce the risk of thrombolism.

[Impact of history of hypertension and blood pressure levels on the risk of thromboembolism in nonvalvular atrial fibrillation patients]

Objective: To investigate the impact of history of hypertension and blood pressure levels on the thromboembolism risk in the setting of nonvalvular atrial fibrillation (NVAF). Methods: China Atrial Fibrillation Registry Study prospectively enrolled 25 512 atrial fibrillation (AF) patients between August 2011 and December 2018. After exclusion of patients with valvular AF, hypertrophic cardiomyopathy, receiving anticoagulation or ablation therapy at the enrollment, 7 757 patients were included in analysis. The primary endpoint was the time to the first occurrence of ischemic stroke or systemic embolism. Cox proportional hazards models were performed to evaluate whether a history of hypertension or blood pressure levels were independently associated with thromboembolism. Results: During a mean follow up of (35±25) months, 455 （5.9%）thromboembolic events occurred. The crude incidence rate of thromboembolism in patients with a history of hypertension was higher than that in patients without hypertension (2.38 vs. 1.35 per 100 patient-years, χ²=16.8，Log-rank P<0.001). Patients were further divided into 4 groups according to systolic blood pressure (SBP) levels at baseline, the crude incidence rate of thromboembolism significantly increased in proportion to the elevation of SBP levels (χ²=17.9，Log-rank P<0.001). However, there was no significant difference in thromboembolism risk among 4 groups stratified by diastolic blood pressure (DBP) levels (χ²=0.6，Log-rank P=0.907). Multivariable regression analysis showed that history of hypertension was independently associated with a 27% higher risk of thromboembolism (HR=1.27, 95%CI 1.01-1.61, P=0.045). Patients with SBP≥140 mmHg (1 mmHg=0.133 kPa) was associated with 36% higher risk of thromboembolism than patients with SBP<120 mmHg (HR=1.36, 95%CI 1.02-1.82, P=0.036). However, patients with SBP 120-129 mmHg or 130-139 mmHg were not at a higher risk of thromboembolism as compared to the patients with SBP<120 mmHg (SBP 120-129 mmHg: HR=1.23, 95%CI 0.90-1.67, P=0.193; SBP 130-139 mmHg: HR=1.30, 95%CI 0.95-1.77, P=0.098). In addition, DBP levels were not independently associated with the increased thromboembolism risk. Conclusion: A history of hypertension and SBP≥140 mmHg are independent predictors of thromboembolism risk in patients with NVAF. These results indicate that intensive efforts to lower SBP below 140 mmHg might be an important strategy to reduce the risk of stroke in patients with NVAF.

Visual conditions affecting eye growth alter diurnal levels of vitreous DOPAC

In chicks, the diurnal patterns of retinal dopamine synthesis and release are associated with refractive development. To assess the within-day patterns of dopamine release, we assayed vitreal levels of DOPAC (3,4-dihydroxyphenylacetic acid) using high performance liquid chromatography with electrochemical detection, at 4-h intervals over 24 h in eyes with experimental manipulations that change ocular growth rates. Chicks were reared under a 12 h light/12 h dark cycle; experiments began at 12 days of age. Output was assessed by modelling using the robust variance structure of Generalized Estimating Equations. Continuous spectacle lensdefocus or form deprivation: One group experienced non-restricted visual input to both eyes and served as untreated "normal" controls. Three experimental cohorts underwent monocular visual alterations known to alter eye growth and refraction: wearing a diffuser, a negative lens or a positive lens. After one full day of device-wear, chicks were euthanized at 4-h intervals over 24 h (8 birds per time/condition). Brief hyperopic defocus: Chicks wore negative lenses for only 2 daily hours either in the morning (starting at ZT 0; n = 16) or mid-day (starting at ZT 4; n = 8) for 3 days. Vitreal DOPAC was assayed. In chicks with bilateral non-restricted vision, or with continuous defocus or form-deprivation, there was a diurnal variation in vitreal DOPAC levels for all eyes (p < 0.001 for each). In normal controls, DOPAC was highest during the daytime, lowest at night, and equivalent for both eyes. In experimental groups, regardless of whether experiencing a growth stimulatory input (diffuser; negative lens) or growth inhibitory input (positive lens), DOPAC levels were reduced compared both to fellow eyes and to those of normal controls (p < 0.001 for each). These diurnal variations in vitreous DOPAC levels under different visual conditions indicate a complexity for dopaminergic mechanisms in refractive development that requires further study.

Limited Protection Conferred by Recombinant Newcastle Disease Virus Expressing Infectious Bronchitis Spike Protein

Recombinant Newcastle disease virus (NDV) LaSota (LS) expressing secreted trimeric spike (S)-ectodomain (Se) of infectious bronchitis virus (IBV) (rLS/IBV.Se) was developed and evaluated for protection conferred against IBV challenge. The IBV S-ectodomain protein, which is S excluding the transmembrane anchor and short cytoplasmic domain of S2, expressed from recombinant LS corresponds to an Arkansas (Ark)-type IBV. In a first experiment, chickens were primed at 1 day of age or primed at 1 day of age and boosted at 14 days of age with 10⁴ 50% embryo infectious doses (EID₅₀)/bird of rLS/IBV.Se and challenged with a virulent Ark strain. A single vaccination proved completely ineffective at protecting chickens against challenge, whereas priming and boosting reduced clinical signs and tracheal lesions but did not reduce viral load in lachrymal fluids. In experiment 2, the vaccine dose was increased to 10⁷ EID₅₀/bird and a different virulent Ark strain was used for challenge. In addition, chickens were singly immunized on either day 1 or day 10 after hatch. NDV antibody levels detected in vaccinated chickens were moderate, with hemagglutination inhibition titers varying between 4 and 5 log₂. Slightly higher antibody levels to NDV were observed in chickens vaccinated on day 10 versus day 1 but without the difference achieving statistical significance. In contrast, antibody responses measured using recombinant IBV S1 protein-coated ELISA plates were significantly greater in chickens vaccinated on day 10 than on day 1. The use of a higher rLS/IBV.Se dose substantially enhanced the success of a single vaccination compared to experiment 1. Signs and tracheal lesions were reduced more effectively in chickens vaccinated at day 10 after hatch. However, as in experiment 1, vaccination did not reduce the viral loads in tear fluids of challenged chickens. Similar results, in which no reduction in viral load in the trachea was apparent from rLS/IBV.S vaccination, have been obtained by others. Further work is needed to understand the immune responses induced by this recombinant virus that seems to provide some protection against the disease but does not reduce viral loads in the upper respiratory tract.