Electrodynamic Heart Model Construction and ECG Simulation

Objectives: In this paper, we present a unified electrodynamic heart model that permits simulations of the body surface potentials generated by the heart in motion. The inclusion of motion in the heart model significantly improves the accuracy of the simulated body surface potentials and therefore also the 12-lead ECG.

Methods: The key step is to construct an electromechanical heart model. The cardiac excitation propagation is simulated by an electrical heart model, and the resulting cardiac active forces are used to calculate the ventricular wall motion based on a mechanical model. The source-field point relative position changes during heart systole and diastole. These can be obtained, and then used to calculate body surface ECG based on the electrical heart-torso model.

Results: An electromechanical biventricular heart model is constructed and a standard 12-lead ECG is simulated. Compared with a simulated ECG based on the static electrical heart model, the simulated ECG based on the dynamic heart model is more accordant with a clinically recorded ECG, especially for the ST segment and T wave of a V1-V6 lead ECG. For slight-degree myocardial ischemia ECG simulation, the ST segment and T wave changes can be observed from the simulated ECG based on a dynamic heart model, while the ST segment and T wave of simulated ECG based on a static heart model is almost unchanged when compared with a normal ECG.

Conclusions: This study confirms the importance of the mechanical factor in the ECG simulation. The dynamic heart model could provide more accurate ECG simulation, especially for myocardial ischemia or infarction simulation, since the main ECG changes occur at the ST segment and T wave, which correspond with cardiac systole and diastole phases.

[Clinical features and prognosis of 18 cases of primary lymphocytic hypophysitis]

Objective: To analyze clinical features, prognosis and treatment of lymphocytic hypophysitis (LYH). Methods: The clinical data, treatments and outcomes of 18 cases diagnosed as LYH at Chinese PLA General Hospital between January 2001 and July 2017 was respectively reviewed. Results: Eighteen patients with histology-proven LYH (13 females and 5 males ) were identified. All lymphocytic adenohypophysitis (LAH) were females(n=6), two of whom were associated with pregnancy. Eleven patients (6 females and 5 males) had lymphocytic panhypophysitis (LPH) and one(female) had hypothalamitis. Pre-treatment evaluation revealed that 11 patients presented with symptoms of intracranial space-occupying lesions, 12 patients had symptoms of anterior pituitary hormone deficiencies, and 12 patients had central diabetes insipidus (CDI). All patients had space-occupying lesions on magnetic resonance imaging (MRI), which were symmetrically enlarged and homogenously enhanced with or without pituitary stalk thickening. Before or after surgery, 11 patients received immunosuppressant therapy or radiotherapy to alleviate space-occupying effect. After 4-204 months follow-up, 5 patients had a relapse and received immunosuppressants, radiotherapy or surgery to achieve remission. Full recovery (both symptomatic and radiographic) was seen in 6 patients, and 11 patients maintained stable replacement therapy. Conclusions: LYH presents with acute space-occupying effects such as headache, visual disturbances, hypopituitarism, CDI and mild hyperprolactinemia, especially with characteristic radiographic manifestations. Usually, surgery reliably establishes diagnosis, and immunosuppressant therapy is a necessity. On the whole, LYH has a good prognosis.

Distribution and quantitative analysis of CIDEa and CIDEc in broiler chickens: accounting for differential fat deposition between strains

1. Differences in the expression of CIDEa and CIDEc in 20 different tissues were examined. Both CIDEa and CIDEc mRNA transcripts were predominantly but variably expressed in white adipose tissue (WAT) but were also expressed at moderate levels in the kidney and liver and at lower levels in the ovary. Interestingly, among WAT types, both CIDEa and CIDEc were expressed at the lowest levels in heart coronary WAT. 2. To better understand the roles of CIDEa and CIDEc in the fat deposition of broiler chickens, the differences in lipid droplet (LD) size and mRNA levels of CIDEa and CIDEc between lean-type and fat-type broiler chicken lines were studied. LD sizes were larger in fat-type broiler lines, and CIDEa and CIDEc mRNA levels in white adipose, kidney and liver tissues were significantly higher in fat-type broiler lines than in their lean counterparts. 3. Developmental expression patterns of CIDEa and CIDEc mRNA were analysed in different tissue types (WAT, liver and kidney) in Arbor Acres broiler chickens, and CIDEa and CIDEc mRNA expression levels increased during sequential developmental stages, achieving peak expression levels at week 6. 4. These observations suggest that the functions of CIDEa and CIDEc reflect inherent characteristics of lipid metabolism that contribute to the differences in fat deposition between strains. The results in this study contribute to a more robust understanding of the tissue distribution and expression patterns of CIDEa and CIDEc mRNA and facilitate further research concerning the molecular mechanism underlying fat deposition in broiler chickens.

miR-146a rs2910164 polymorphism might be associated with coronary artery disease risk in Asians

Recently, several studies reported the association between miR-146a rs2910164 polymorphism and coronary artery disease (CAD) risk. However, the results were inconclusive. We therefore did a meta-analysis to investigate this association. Electronic databases, including PubMed, EMBASE, and China National Knowledge Infrastructure (CNKI) databases, were searched. The strength of association was assessed by calculating odds ratios (OR) and 95% confidence interval (CI). Five eligible studies included in this meta-analysis. The total sample size of this meta-analysis was 1565 cases and 1541 controls. We found that miR-146a rs2910164 polymorphism was significantly associated with an increased CAD risk (OR = 1.19; 95% CI 1.07 - 1.32; P = 0.002). In the subgroup analysis by race, miR-146a rs2910164 polymorphism was significantly associated with an increased CAD risk in Asians (OR = 1.18; 95% CI 1.04 - 1.33; P = 0.008). However, we did not find significant result in Caucasians (OR = 1.22; 95% CI 0.86 - 1.74; P = 0.25). In the subgroup analysis by age, we found that miR-146a rs2910164 polymorphism increased CAD risk in old population (OR = 1.22; 95% CI 1.09 - 1.38; P = 0.0008). In conclusion, this meta-analysis found that miR-146a rs2910164 polymorphism was significantly associated with CAD risk.

[Characterization of N-linked glycosylation sites on envelope proteins of simian/human immunodeficiency virus in peripheral blood of Chinese rhesus macaques during acute infection]

Objective: To investigate the number and distribution of N-linked glycosylation sites of simian/human immunodeficiency virus envelope proteins(SHIV_SF162P3)and SHIV transmission. Methods: Two female adult Chinese rhesus macaques(4 years old)were intravenously inoculated with 300 TCID50 SHIV_SF162P3. The macaques weighed 4 and 5 kg and were identified as Rh1 and Rh2. We collected plasma samples at days 3, 7, 10, 14, 17, 21, 24, 28, 35, 42, 49, 56, 63, 70 and 77 post-challenge. Subsequently, we monitored plasma viral load by real-time PCR after viral RNA isolation and cDNA synthesis. We amplified the full-length envelope gene by single genome amplification(SGA)at days 7, 14, 28 and 77. BioEdit, MEGA, and the HIV Databases were used to analyze envelope sequences. Sequence diversity and N-linked glycosylation sites were compared between virus stock and plasma viruses of the two macaques. Results: A total of 55 env sequences were obtained from virus stock and their average pairwise distances were(0.166 6± 0.096 3)%. Viral loads peaked at 7.68 and 7.49 log10 copies/ml at day 10 and reached the set point at day 42(4.27 and 4.81 log10 copies/ml). The percentages of envelope sequences containing 25 potential N-linked glycosylation sites(PNGSs)were 83%(20/24)and 94%(29/31)in Rh1 and Rh2, respectively, at day 7; these were significantly higher than the proportion in SHIV_SF162P3 stock(49%(27/55)). Viral diversity after infection increased with time whereas the proportion of sequences containing 25 PNGSs decreased and sequences containing 27 PNGSs gradually increased. In Rh1, the percentage of sequences containing 27 PNGSs increased to 29% at day 28 and reached 35% at day 77 in Rh2. By analyzing the number of PNGSs in the V1-V5 regions, we found that PNGS variation mainly occurred in the V4 loop. Compared with sequences containing 27 PNGSs, a seven amino acid(TWNNTIG)deletion was found in the V4 loop, which resulted in a loss of two PNGSs at positions 392 and 396. Conclusion: Low glycosylation of the SHIV_SF162P3 V4 loop may facilitate spread of the SHIV virus whereas viruses with highly glycosylated V4 loops showed replication advantages after infection.

Revealing potential long non-coding RNA biomarkers in lung adenocarcinoma using long non-coding RNA-mediated competitive endogenous RNA network

In our study, we aimed to reveal potential long non-coding RNAs (lncRNA) biomarkers in lung adenocarcinoma (LAD) using lncRNA-mediated competing endogenous RNAs (ceRNAs) network (LMCN). Competing lncRNA-mRNA interactions were identified using the hypergeometric test. Co-expression analysis for the competing lncRNA-mRNA interactions was implemented, and relying on the weight value >0.8, a highly competitive LMCN was further constructed. Degree distribution, betweenness and closeness for LMCN were carried out to analyze the network structure. Functional analyses of mRNAs in LMCN were carried out to further explore the biological functions of lncRNAs. Biclique algorithm was utilized to extract competing modules from the LMCN. Finally, we verified our findings in an independent sample set using qRT-PCR. Based on degrees >60, we identified 4 hubs, including DLEU2, SNHG12, HCP5, and LINC00472. Furthermore, 2 competing modules were identified, and LINC00472 in module 1 functioned as a hub in both LMCN and module. Functional implications of lncRNAs demonstrated that lncRNAs were related to histone modification, negative regulation of cell cycle, neuroactive ligand-receptor interaction, and regulation of actin cytoskeleton. qRT-PCR results demonstrated that lncRNAs LINC00472, and HCP5 were down-regulated in LAD tissues, while the expression level of SNHG12 was up-regulated in LAD tissues. Our study sheds novel light on the roles of lncRNA-related ceRNA network in LAD and facilitates the detection of potential lncRNA biomarkers for LAD diagnosis and treatment. Remarkably, in our study, LINC00472, HCP5, and SNHG12 might be potential biomarkers for LAD management.

[An analysis of four cases of misdiagnosed primary lymphocytic hypophysitis]

To improve the differential diagnosis of sellar region mass, 4 cases with sellar mass and misdiagnosed as lymphocytic hypophysitis (LYH) were reviewed retrospectively.The 4 patients (2 male and 2 female) aged 20-60 years old were all presented with symptoms of headache, polydipsia and polyuria.Biochemical studies confirmed the diagnoses of central diabetes insipidus and hypopituitarism.Head MRI scans showed LYH like image for all the cases, and, thus, high dose methylprednisolone pulse therapy (HDMPT) was applied to the patients.Their symptoms deteriorated and the sellar mass enlarged after a short period of partial improvement.Operations were performed in all the patients.Histology study showed craniopharyngioma with abscess, primary abscess, secondary hypophysitis caused by Wegener's granulomatosis, and germinoma with secondary hypophysitis, respectively.In conclusion, surgery or biopsy is necessary for those who presented with sellar region mass and was suspected to be with LYH, but with poor response or even worse after HDMPT.

Characterization of retroviral infectivity and superinfection resistance during retrovirus-mediated transduction of mammalian cells

Retroviral vectors including lentiviral vectors are commonly used tools to stably express transgenes or RNA molecules in mammalian cells. Their utilities are roughly divided into two categories, stable overexpression of transgenes and RNA molecules, which requires maximal transduction efficiency, or functional selection with retrovirus (RV)-based libraries, which takes advantage of retroviral superinfection resistance. However, the dynamic features of RV-mediated transduction are not well characterized. Here, we engineered two murine stem cell virus-based retroviral vectors expressing dual fluorescence proteins and antibiotic markers, and analyzed virion production efficiency and virion stability, dynamic infectivity and superinfection resistance in different cell types, and strategies to improve transduction efficiency. We found that the highest virion production occurred between 60 and 72 h after transfection. The stability of the collected virion supernatant decreased by >60% after 3 days in storage. We found that RV infectivity varied drastically in the tested human cancer lines, while low transduction efficiency was partially overcome with increased virus titer, prolonged infection duration and/or repeated infections. Furthermore, we demonstrated that RV receptors PIT1 and PIT2 were lowly expressed in the analyzed cells, and that PIT1 and/or PIT2 overexpression significantly improved transduction efficiency in certain cell lines. Thus, our findings provide resourceful information for the optimal conditions of retroviral-mediated gene delivery.

CATTLE (CAncer treatment treasury with linked evidence): An integrated knowledge base for personalized oncology research and practice

Despite the existence of various databases cataloging cancer drugs, there is an emerging need to support the development and application of personalized therapies, where an integrated understanding of the clinical factors and drug mechanism of action and its gene targets is necessary. We have developed CATTLE (CAncer Treatment Treasury with Linked Evidence), a comprehensive cancer drug knowledge base providing information across the complete spectrum of the drug life cycle. The CATTLE system collects relevant data from 22 heterogeneous databases, integrates them into a unified model centralized on drugs, and presents comprehensive drug information via an interactive web portal with a download function. A total of 2,323 unique cancer drugs are currently linked to rich information from these databases in CATTLE. Through two use cases, we demonstrate that CATTLE can be used in supporting both research and practice in personalized oncology.

Aligned copper nanorod arrays for highly efficient generation of intense ultra-broadband THz pulses

We demonstrate an intense broadband terahertz (THz) source based on the interaction of relativistic-intensity femtosecond lasers with aligned copper nanorod array targets. For copper nanorod targets with a length of 5 μm, a maximum 13.8 times enhancement in the THz pulse energy (in ≤20 THz spectral range) is measured as compared to that with a thick plane copper target under the same laser conditions. A further increase in the nanorod length leads to a decrease in the THz pulse energy at medium frequencies (≤20 THz) and increase of the electromagnetic pulse energy in the high-frequency range (from 20–200 THz). For the latter, we measure a maximum energy enhancement of 28 times for the nanorod targets with a length of 60 μm. Particle-in-cell simulations reveal that THz pulses are mostly generated by coherent transition radiation of laser produced hot electrons, which are efficiently enhanced with the use of nanorod targets. Good agreement is found between the simulation and experimental results.

Efficacy and safety of basiliximab in liver transplantation for patients with hepatitis B virus-related diseases: a single centre study

AIMS

We aim to evaluate the efficacy and safety of basiliximab in liver transplantation (LT) for patients with hepatitis B virus-related diseases.

METHODS

A total of 268 patients with hepatitis B virus-related diseases undergoing LT were enrolled and divided into two groups according to the usage of basiliximab. Total survival, the survival of high-risk patients defined by the posttransplant model for predicting mortality, acute rejection rate, biochemical parameters and other follow-up data were compared between the two groups.

RESULTS

Group Bas was composed of 131 patients who received basiliximab, and Group Triple enrolled the other 137 patients who did not. Between the two groups, there was no significant difference in the cumulative survival of patients without hepatocellular carcinoma (HCC) or in the cumulative survival of patients with HCC. For patients with benign end-stage liver diseases, Group Bas had more patients with a high risk of short- and medium-term mortality than Group Triple (22.81% vs. 8.85%, p = 0.017), but the survival curves of the two groups were not significantly different. The 1-year incidence of acute rejection was lower in Group Bas, although the difference was not significant (8.75% vs. 15.33%, p > 0.05). In both Group Bas and Group Triple, the level of serum creatinine (Scr) at 1 week posttransplantation was significantly lower than pretransplantation (61.00 vs. 88.50 μmol/l, p < 0.001; 61.50 vs. 74.00 μmol/l, p < 0.001; respectively). There was a significant difference in the pretransplantation Scr between the two groups (88.50 vs. 74.00 μmol/l, p = 0.005), but the values of Scr decreased to the same level 1 week (61.00 vs. 61.50 μmol/l, p > 0.05) and 4 weeks (61.00 vs. 59.00 μmol/l, p > 0.05) after transplantation. Significantly fewer recipients in Group Bas experienced hepatitis B relapse than in Group Triple (2/131 vs. 13/137, p = 0.006).

CONCLUSIONS

A basiliximab-induced immunosuppressive protocol is a safe regimen that achieves similar survival without increasing the acute rejection rate for LT recipients with hepatitis B virus-related diseases. For patients with benign end-stage liver diseases, this regimen reduces medium-term mortality in high-risk patients. This regimen remarkably improves renal function in the first month after LT and is correlated with a decreased hepatitis B recurrence rate in adult patients after LT.