[Role of lncRNA Fez family zinc finger protein 1 antisense RNA1 in hepatocellular carcinoma]

Objective: To investigate the effect of long-chain non-coding RNA Fez family zinc finger protein 1 antisense RNA1 (lncRNA FEZF1-AS1) on the biological function of hepatocellular carcinoma (HCC). Methods: SMMC771 and BEL-7402 cells were transfected with sh-FEZF1-AS1 and OE-FEZF1-AS1, respectively. The expression of lncRNA FEZF1-AS1 was detected by real-time quantitative PCR. Cell proliferation was detected by Cell Counting Kit-8 (CCK-8), and apoptosis was detected by flow cytometry. The effects of lncRNA FEZF1-AS1 on invasion and migration were detected by Transwell and wound healing assays. The expression levels of adhesion molecules were detected by Western blot. The effect of lncRNA FEZF1-AS1 on the in vivo growth was verified by nude mice xenograft experiments. Results: The silencing or ectopic expression of lncRNA FEZF1-AS1 inhibited or promoted the proliferation of hepatocellular carcinoma cells. CCK-8 assay showed that the proliferation abilities of SMMC7721 and BEL-7402 cells in sh-FEZF1-AS1 transfection group significantly decreased, achieving (35.43±4.06)% and (34.68±3.97)%, respectively, on the fifth day. There were significant differences between sh-FEZF1-AS1 group and sh-NC group [52.21±8.46)% and (53.76±7.64)%] (all P<0.05). In contrast, the proliferation ability of SMMC7721 and BEL-7402 cells transfected with OE-FEZF1-AS1 was significantly increased, achieving (83.49±6.92)% and (80.31±3.13)%, respectively, on the fifth day. There were significant differences between OE-FEZF1-AS1 and OE-NC group [53.03±8.84)% and (55.11±7.09)%] (all P<0.05). The subsequent flow cytometry results showed that cell apoptotic rates of SMMC7721 and BEL-7402 cells transfected with sh-FEZF1-AS1 were (13.02±1.38)% and (11.88±1.29)%, respectively, which were significantly higher than those in sh-NC groups [(5.57±1.46)% and (8.06±1.42)%, respectively, all P<0.05]. In contrast, the apoptotic rates of SMMC7721 and BEL-7402 cells transfected with OE-FEZF1-AS1 were (3.01±0.39)% and (3.22±0.43)%, which were significantly lower than those in OE-NC groups [(6.68±0.96)% and (6.63±0.45)%, all P<0.05]. In addition, knockdown or overexpression of lncRNA FEZF1-AS1 expression inhibited or enhanced the migration and invasion abilities as well as the levels of adhesion molecules in hepatocellular carcinoma cells. After 30 days of feeding under the same conditions, the tumor volumes of sh-FEZF1-AS1 and sh-NC SMMC7721 cells xenograft mice models were (0.26±0.03) cm(3) and (0.63±0.06) cm(3), respectively, showing significant difference (P<0.05). The tumor volumes of sh-FEZF1-AS1 and sh-NC BEL-7402 cells were (0.31±0.02) cm(3) and (0.72±0.08) cm(3), and the difference was statistically significant (P<0.05). Conclusion: lncRNA FEZF1-AS1 may strengthen the growth, migration and invasion of hepatocellular carcinoma cells.

Detection of Spin-Vibration States in Single Magnetic Molecules

The spin states of magnetic molecules have advantageous attributes as carriers of quantum information. However, spin-vibration coupling in molecules causes a decay of excited spin states and a loss of spin coherence. Here, we detect excitations of spin-vibration states in single nickelocene molecules on Ag(110) with a scanning tunneling microscope. By transferring a nickelocene to the tip, the joint spin-vibration states with an adsorbed nickelocene were measured. Chemical variations in magnetic molecules offer the opportunity to tune spin-vibration coupling for controlling the spin coherence.

Genome-wide identification and expression analysis reveal the potential function of ethylene responsive factor gene family in response to Botrytis cinerea infection and ovule development in grapes (Vitis vinifera L.)

The prevention of Botrytis cinerea infection and the study of grape seedlessness are very important for grape industries. Finding correlated regulatory genes is an important approach towards understanding their molecular mechanisms. Ethylene responsive factor (ERF) gene family play critical roles in defence networks and the growth of plants. To date, no large-scale study of the ERF proteins associated with pathogen defence and ovule development has been performed in grape (Vitis vinifera L.). In the present study, we identified 113 ERF genes (VvERF) and named them based on their chromosome locations. The ERF genes could be divided into 11 groups based on a multiple sequence alignment and a phylogenetic comparison with homologues from Arabidopsis thaliana. Synteny analysis and Ka/Ks ratio calculation suggested that segmental and tandem duplications contributed to the expansion of the ERF gene family. The evolutionary relationships between the VvERF genes were investigated by exon-intron structure characterisation, and an analysis of the cis-acting regulatory elements in their promoters suggested potential regulation after stress or hormone treatments. Expression profiling after infection with the fungus, B. cinerea, indicated that ERF genes function in responses to pathogen attack. In addition, the expression levels of most ERF genes were much higher during ovule development in seedless grapes, suggesting a role in ovule abortion related to seedlessness. Taken together, these results indicate that VvERF proteins are involved in responses to Botrytis cinerea infection and in grape ovule development. This information may help guide strategies to improve grape production.

Predicting critical drug concentrations and torsadogenic risk using a multiscale exposure-response simulator

Torsades de pointes is a serious side effect of many drugs that can trigger sudden cardiac death, even in patients with structurally normal hearts. Torsadogenic risk has traditionally been correlated with the blockage of a specific potassium channel and a prolonged recovery period in the electrocardiogram. However, the precise mechanisms by which single channel block translates into heart rhythm disorders remain incompletely understood. Here we establish a multiscale exposure-response simulator that converts block-concentration characteristics from single cell recordings into three-dimensional excitation profiles and electrocardiograms to rapidly assess torsadogenic risk. For the drug dofetilide, we characterize the QT interval and heart rate at different drug concentrations and identify the critical concentration at the onset of torsades de pointes: For dofetilide concentrations of 2x, 3x, and 4x, as multiples of the free plasma concentration Cmax = 2.1 nM, the QT interval increased by +62.0%, +71.2%, and +82.3% compared to baseline, and the heart rate changed by -21.7%, -23.3%, and +88.3%. The last number indicates that, at the critical concentration of 4x, the heart spontaneously developed an episode of a torsades-like arrhythmia. Strikingly, this critical drug concentration is higher than the concentration estimated from early afterdepolarizations in single cells and lower than in one-dimensional cable models. Our results highlight the importance of whole heart modeling and explain, at least in part, why current regulatory paradigms often fail to accurately quantify the pro-arrhythmic potential of a drug. Our exposure-response simulator could provide a more mechanistic assessment of pro-arrhythmic risk and help establish science-based guidelines to reduce rhythm disorders, design safer drugs, and accelerate drug development.

The effect of hyaluronic acid on the corrosion of an orthopedic CoCrMo-alloy in simulated inflammatory conditions

During joint inflammation, various reactive oxygen species (ROS) are present in the surrounding tissue and joint fluid. In the laboratory, hydrogen peroxide (H₂O₂) is typically used to simulate inflammatory conditions, and media containing proteins and hyaluronic acid (HA) are employed to simulate joint synovial fluid. Electrochemical interactions between H₂O₂ and HA in the presence of a CoCrMo surface are expected, since HA molecules contain redox-active moieties. We hypothesized that any redox reactions of these moieties with ROS will mitigate the oxidizing effect of H₂O₂ on the CoCrMo surface, limiting the corrosion rate of the metal. Non-destructive electrochemical measurements (open circuit potential, linear polarization resistance and electrochemical impedance spectroscopy) were used to investigate the corrosion response of CoCrMo in synovial model fluid containing physiologically relevant concentrations of albumin proteins and hyaluronic acid, with and without H₂O₂. Two different molarities of H₂O₂, 3 mM and 30 mM, were tested. While both molarities are within physiological limits, 3mM is well within the range HA could mitigate, whereas 30 mM is not. Contrary to our hypothesis, HA did not alleviate corrosion in 3 mM H₂O₂ and even caused a corrosion increase in the case of 30 mM H₂O₂. The decrease in corrosion resistance of the alloy may be attributed to the complexation of degenerated HA molecular chains with chromium ions released from the metallic surface, which are necessary to build a protective oxide film. This finding has clinical implications, suggesting that HA accelerates corrosion of CoCrMo implants in the presence of strong inflammation.

Association between Tumor Acidity and Hypervascularity in Human Gliomas Using pH-Weighted Amine Chemical Exchange Saturation Transfer Echo-Planar Imaging and Dynamic Susceptibility Contrast Perfusion MRI at 3T

BACKGROUND AND PURPOSE

Acidification of the tumor microenvironment from abnormal metabolism along with angiogenesis to meet metabolic demands are both hallmarks of malignant brain tumors; however, the interdependency of tumor acidity and vascularity has not been explored. Therefore, our aim was to investigate the association between pH-sensitive amine chemical exchange saturation transfer echoplanar imaging (CEST-EPI) and relative cerebral blood volume (CBV) measurements obtained from dynamic susceptibility contrast (DSC) perfusion MRI in patients with gliomas.

MATERIALS AND METHODS

In this retrospective study, 90 patients with histologically confirmed gliomas were scanned between 2015 and 2018 (median age, 50.3 years; male/female ratio = 59:31). pH-weighting was obtained using chemical exchange saturation transfer echo-planar imaging estimation of the magnetization transfer ratio asymmetry at 3 ppm, and CBV was estimated using DSC-MR imaging. The voxelwise correlation and patient-wise median value correlation between the magnetization transfer ratio asymmetry at 3 ppm and CBV within T2-hyperintense lesions and contrast-enhancing lesions were evaluated using the Pearson correlation analysis.

RESULTS

General colocalization of elevated perfusion and high acidity was observed in tumors, with local intratumor heterogeneity. For patient-wise analysis, median CBV and magnetization transfer ratio asymmetry at 3 ppm within T2-hyperintense lesions were significantly correlated (R = 0.3180, P = .002), but not in areas of contrast enhancement (P = .52). The positive correlation in T2-hyperintense lesions remained within high-grade gliomas (R = 0.4128, P = .001) and in isocitrate dehydrogenase wild-type gliomas (R = 0.4300, P = .002), but not in World Health Organization II or in isocitrate dehydrogenase mutant tumors. Both magnetization transfer ratio asymmetry at 3 ppm and the voxelwise correlation between magnetization transfer ratio asymmetry and CBV were higher in high-grade gliomas compared with low-grade gliomas in T2-hyperintense tumors (magnetization transfer ratio asymmetry, P = .02; Pearson correlation, P = .01). The same trend held when comparing isocitrate dehydrogenase wild-type gliomas and isocitrate dehydrogenase mutant gliomas (magnetization transfer ratio asymmetry, P = .04; Pearson correlation, P = .01).

CONCLUSIONS

A positive linear correlation between CBV and acidity in areas of T2-hyperintense, nonenhancing tumor, but not enhancing tumor, was observed across patients. Local heterogeneity was observed within individual tumors.

Probing and imaging spin interactions with a magnetic single-molecule sensor

Magnetic single atoms and molecules are receiving intensifying research focus because of their potential as the smallest possible memory, spintronic, and qubit elements. Scanning probe microscopes used to study these systems have benefited greatly from new techniques that use molecule-functionalized tips to enhance spatial and spectroscopic resolutions and enable new sensing capabilities. We demonstrate a microscopy technique that uses a magnetic molecule, Ni(cyclopentadienyl)₂, adsorbed at the apex of a scanning probe tip, to sense exchange interactions with another molecule adsorbed on a Ag(110) surface in a continuously tunable fashion in all three spatial directions. We further used the probe to image contours of exchange interaction strength, revealing angstrom-scale regions where the quantum states of two magnetic molecules strongly mix. Our results pave the way for new nanoscale imaging capabilities based on magnetic single-molecule sensors.

Machine learning in drug development: Characterizing the effect of 30 drugs on the QT interval using Gaussian process regression, sensitivity analysis, and uncertainty quantification

Prolonged QT intervals are a major risk factor for ventricular arrhythmias and a leading cause of sudden cardiac death. Various drugs are known to trigger QT interval prolongation and increase the proarrhythmic potential. Yet, how precisely the action of drugs on the cellular level translates into QT interval prolongation on the whole organ level remains insufficiently understood. Here we use machine learning techniques to systematically characterize the effect of 30 common drugs on the QT interval. We combine information from high fidelity three-dimensional human heart simulations with low fidelity one-dimensional cable simulations to build a surrogate model for the QT interval using multi-fidelity Gaussian process regression. Once trained and cross-validated, we apply our surrogate model to perform sensitivity analysis and uncertainty quantification. Our sensitivity analysis suggests that compounds that block the rapid delayed rectifier potassium current I Kr have the greatest prolonging effect of the QT interval, and that blocking the L-type calcium current I CaL and late sodium current I NaL shortens the QT interval. Our uncertainty quantification allows us to propagate the experimental variability from individual block-concentration measurements into the QT interval and reveals that QT interval uncertainty is mainly driven by the variability in I Kr block. In a final validation study, we demonstrate an excellent agreement between our predicted QT interval changes and the changes observed in a randomized clinical trial for the drugs dofetilide, quinidine, ranolazine, and verapamil. We anticipate that both the machine learning methods and the results of this study will have great potential in the efficient development of safer drugs.

Down-regulated expression of Tim-3 promotes invasion and metastasis of colorectal cancer cells

To explore how Tim-3 is expressed and how its expression influences invasion and metastasis of colorectal cancer (CRC) cells. A total of 188 CRC patients were prospectively collected for this study. Meanwhile, 135 normal controls were incorporated during the same period. Intestinal samples of the CRC radical cancerous tissues, paracancerous tissues ( 5.0 cm beyond the cancer tissue) were collected for the following experiment. Furthermore, peripheral venous blood samples (10 ml) were collected from each subject. Immunohistochemical analysis, quantitative real-time polymerase chain reaction (RT-qPCR) and western blot were performed for the detection of Tim-3 in different tissues. The immunohistochemical staining results showed that a positive Tim-3 signal was localized in the cytoplasm and nucleus, observed as yellow or brown granules. Tim-3 was largely expressed in colon carcinoma tissues and normal colon mucosa tissues but was rarely expressed in the cell membrane. RT-qPCR results indicated that Tim-3 mRNA levels were significantly lower in CRC tissues than in paracancerous tissues and normal colon mucosa tissues. A trend of decreased Tim-3 mRNA levels was also found in the paracancerous tissues compared with the normal colon mucosa tissues (all P < 0.05). Western blot results revealed reduced Tim-3 protein expression in CRC tissues compared with normal colon mucosa tissues and paracancerous tissues, and Tim-3 protein expression was much lower in the paracancerous tissues than in the normal colon mucosa tissues (all P < 0.05). Furthermore, obviously lower Tim-3 mRNA levels were found in the poorly differentiated CRC patients and in those with lymph node metastasis and distant metastasis (all P < 0.05). Collectively, Tim-3 expression was mainly located in the cytoplasm and nucleus, showing down-regulated expression in colon carcinoma tissues compared with normal and paracancerous tissues. Reduced Tim-3 expression may promote CRC invasion and metastasis providing a medical reference for the treatment of CRC.

[Liver transplantation for polycystic liver disease: 11 cases report and literature review]

Objective: To explore the indications and safety of orthopedic liver transplantation for polycystic liver disease (PLD). Methods: Data of 11 patients with PLD who underwent orthotopic liver transplantation between 2004 and 2013 was retrospectively analyzed. Demographic, clinical and follow-up data were collected for statistical analysis. The survival rate was calculated by Kaplan-Meier method. Results: Over a period of 10 years, the patients received modified piggyback orthopedic liver transplantation (n=9) or combined liver-kidney transplantation (n=2) for PLD. The recipients' median age was 56 years. Seven patients were classified as Gigot type Ⅱ PLD, and four were classified as Gigot type Ⅲ PLD. Eight patients had severe decreased mobility (Eastern Cooperative Oncology Group, ECOG≥3). Only three cases were Child-Pguh Class C patients and the model for end-stage liver disease (MELD) score was>20. The mean hospitalization duration was (45.4±15.3) days, and the mean length of stay in intensive care unit was (4.1±1.9) days. The perioperative mortality was 18.2% and morbidity of complications was 63.6%. The median follow-up period was 111 months. Two patients died of severe complications after combined liver-kidney transplantation. One patient died of ischemia cholangitis during follow-up. The actuarial 1-, 5-and 10-year survival rate during the follow-up period was 82.2%, 81.8%, and 65.5%, respectively. Conclusions: Liver transplantation is the only curative and safe procedure for PLD, and it provides a good long-term prognosis and high quality of life for PLD patients. Liver transplantation could be a primary option in treating progressive or advanced PLD.

Spectroscopic Investigation of the Effect of Microstructure and Energetic Offset on the Nature of Interfacial Charge Transfer States in Polymer: Fullerene Blends

Despite performance improvements of organic photovoltaics, the mechanism of photoinduced electron–hole separation at organic donor–acceptor interfaces remains poorly understood. Inconclusive experimental and theoretical results have produced contradictory models for electron–hole separation in which the role of interfacial charge-transfer (CT) states is unclear, with one model identifying them as limiting separation and another as readily dissociating. Here, polymer–fullerene blends with contrasting photocurrent properties and enthalpic offsets driving separation were studied. By modifying composition, film structures were varied from consisting of molecularly mixed polymer–fullerene domains to consisting of both molecularly mixed and fullerene domains. Transient absorption spectroscopy revealed that CT state dissociation generating separated electron–hole pairs is only efficient in the high energy offset blend with fullerene domains. In all other blends (with low offset or predominantly molecularly mixed domains), nanosecond geminate electron–hole recombination is observed revealing the importance of spatially localized electron–hole pairs (bound CT states) in the electron–hole dynamics. A two-dimensional lattice exciton model was used to simulate the excited state spectrum of a model system as a function of microstructure and energy offset. The results could reproduce the main features of experimental electroluminescence spectra indicating that electron–hole pairs become less bound and more spatially separated upon increasing energy offset and fullerene domain density. Differences between electroluminescence and photoluminescence spectra could be explained by CT photoluminescence being dominated by more-bound states, reflecting geminate recombination processes, while CT electroluminescence preferentially probes less-bound CT states that escape geminate recombination. These results suggest that apparently contradictory studies on electron–hole separation can be explained by the presence of both bound and unbound CT states in the same film, as a result of a range of interface structures.

Near Real-Time Implementation of An Adaptive Seismocardiography – ECG Multimodal Framework for Cardiac Gating

Objective: Accurate gating for data acquisition of computed tomography (CT) is crucial to obtaining high quality images for diagnosing cardiovascular diseases. To illustrate the feasibility of an optimized cardiac gating strategy, we present a near real-time implementation based on fusing seismocardiography (SCG) and ECG. Methods: The implementation was achieved via integrating commercial hardware and software platforms. Testing was performed on five healthy subjects (age: 24–27; m/f: 4/1) and three cardiac patients (age: 41–71; m/f: 2/1), and compared with baseline quiescence derived from echocardiography. Results: The average latency introduced by computerized processing was 5.1 ms, well within a 100 ms tolerance bounded by data accumulation time for quiescence prediction. The average prediction error associated with conventional ECG-only versus SCG-ECG-based method over all subjects were 59.58 ms and 27.24 ms, respectively. Discussion: The results demonstrate that the multimodal framework can achieve improved quiescence prediction accuracy over the ECG-only-based method in near real-time.

Significant Efficacy of Apatinib in a Patient With Hepatocellular Carcinoma Lung Metastases After Liver Transplantation: A Case Report

Antiangiogenesis therapy plays an important role in the treatment of advanced hepatocellular carcinoma (HCC). However, treatment options for HCC recurrence after liver transplantation are currently limited. Apatinib is a small tyrosine kinase inhibitor molecule targeting vascular endothelial growth factor receptor-2. Here, we report for the first time one case of a patient with advanced HCC who received apatinib after occurring lung metastasis 7 months after liver transplantation. He took 500 mg of apatinib daily for one month, which was decreased to 250 mg daily because of side effects. The patient was confirmed to have a partial response, according to the Response Evaluation Criteria in Solid Tumors, for 10 months, and the progression-free survival time was greater than 21 months. Our data and experience have indicated that apatinib may be a good choice for HCC recurrence after liver transplantation.

Monolithic Axial and Radial Metal-Semiconductor Nanowire Heterostructures

The electrical and optical properties of low-dimensional nanostructures depend critically on size and geometry and may differ distinctly from those of their bulk counterparts. In particular, ultrathin semiconducting layers as well as nanowires have already proven the feasibility to realize and study quantum size effects enabling novel ultrascaled devices. Further, plasmonic metal nanostructures attracted recently a lot of attention because of appealing near-field-mediated enhancement effects. Thus, combining metal and semiconducting constituents in quasi one-dimensional heterostructures will pave the way for ultrascaled systems and high-performance devices with exceptional electrical, optical, and plasmonic functionality. This Letter reports on the sophisticated fabrication and structural properties of axial and radial Al-Ge and Al-Si nanowire heterostructures, synthesized by a thermally induced exchange reaction of single-crystalline Ge-Si core-shell nanowires and Al pads. This enables a self-aligned metallic contact formation to Ge segments beyond lithographic limitations as well as ultrathin semiconducting layers wrapped around monocrystalline Al core nanowires. High-resolution transmission electron microscopy, energy dispersive X-ray spectroscopy, and μ-Raman measurements proved the composition and perfect crystallinity of these metal-semiconductor nanowire heterostructures. This exemplary selective replacement of Ge by Al represents a general approach for the elaboration of radial and axial metal-semiconductor heterostructures in various Ge-semiconductor heterostructures.

[Screening of microRNAs targeting Notch signaling pathway implicated in inner ear development and the role of microRNA-384-5p]

Objective: To screen the key microRNAs targeting Notch signaling pathway in inner ear and investigate its potential regulating function. Methods: The interaction network and the Core-Notch network, involved with key genes in Notch signal pathway and differential-expressed microRNAs in inner ear, were constructed by bioinformatics methods. The important microRNAs in regulating Notch signaling pathway were screened via topological and GO analysis, followed by in vivo and in vitro investigation. Results: MiRNA-384-5p was identified as a key regulator specifically expressed in mouse brain and inner ear, which could down-regulate Notch1. The Notch1 expression was found significantly down-regulated in miRNA-384-5p-mimic-transfected HeLa cells. The dual-luciferase reporter gene assay further confirmed the effect of miRNA-384-5p on the down-regulation of Notch1 and Dll4 in Notch signaling pathway. Conclusions: The Core-Notch network is constructed to screen microRNAs implicated in inner ear development, and miRNA-384-5p is screened and verified to be target-regulating the Notch signaling pathway, which could be the potential target in the regeneration of impaired hair cells.