607 research outputs found

    Sweroside Alleviated Aconitine-Induced Cardiac Toxicity in H9c2 Cardiomyoblast Cell Line

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    Aconitine is the main bioactive ingredient of Aconitum plants, which are well-known botanical herbs in China. Aconitine is also notorious for its high cardiotoxicity, as it can induce life-threatening ventricular arrhythmias. Unfortunately, there are few effective antidotes to aconitine toxicity. This study aimed to evaluate the potent protective effects of the ingredients from V. baillonii on aconitine toxicity on H9c2 cell line. Cell viability was assessed by methylthiazoltetrazolium bromide (MTT). Intracellular Ca2+ concentration alteration and reactive oxygen species (ROS) generation were observed by confocal microscopy and flow cytometry, respectively. Cellular oxidative stress was analyzed by measuring malondialdehyde (MDA) and superoxide dismutase (SOD) levels. Mitochondrial membrane potential (ΔΨ) was determined using JC-1 kit. RT-PCR and Hoechst staining techniques were conducted to determine the levels of autophagy/apoptosis. The mRNA levels of dihydropyridine receptor (DHPR), ryanodine receptors (RyR2) and sarcoplasmic reticulum Ca2+-ATPase (SERCA) were measured by RT-PCR. We screened six components from V. baillonii, among which, sweroside exhibited the strongest protective effects on aconitine-induced cardiac toxicity. Sweroside suppressed the aconitine-induced mRNA expressions of NaV1.5 (encoded by SCN5A), RyR2 and DHPR, and reversed the aconitine-induced decrease in mRNA level of SERCA, thus preventing the aconitine-induced persistent intracellular Ca2+ accumulation and avoiding intracellular Ca2+ overload. We further found that sweroside restabilized the aconitine-disrupted mitochondrial membrane potential (ΔΨ) and reversed the aconitine-induced increase in the mRNA levels of cell autophagy-related factors (Beclin-1, Caspase-3, and LC3- II) in H9c2 cells. In the whole-animal experiments, we observed that sweroside (50 mg/kg) alleviated effectively aconitine-induced arrhythmias by analysis of electrocardiogram (ECG) recording in rats. Our results demonstrate that sweroside may protect cardiomyocytes from aconitine toxicity by maintaining intracellular Ca2+ homeostasis, restabilizing mitochondrial membrane potential (ΔΨ) and avoiding cell autophagy/apoptosis

    Insights into the Ecological Roles and Evolution of Methyl-Coenzyme M Reductase-Containing Hot Spring Archaea

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    Several recent studies have shown the presence of genes for the key enzyme associated with archaeal methane/alkane metabolism, methyl-coenzyme M reductase (Mcr), in metagenome-assembled genomes (MAGs) divergent to existing archaeal lineages. Here, we study the mcr-containing archaeal MAGs from several hot springs, which reveal further expansion in the diversity of archaeal organisms performing methane/alkane metabolism. Significantly, an MAG basal to organisms from the phylum Thaumarchaeota that contains mcr genes, but not those for ammonia oxidation or aerobic metabolism, is identified. Together, our phylogenetic analyses and ancestral state reconstructions suggest a mostly vertical evolution of mcrABG genes among methanogens and methanotrophs, along with frequent horizontal gene transfer of mcr genes between alkanotrophs. Analysis of all mcr-containing archaeal MAGs/genomes suggests a hydrothermal origin for these microorganisms based on optimal growth temperature predictions. These results also suggest methane/alkane oxidation or methanogenesis at high temperature likely existed in a common archaeal ancestor

    PCBP-1 regulates alternative splicing of the CD44 gene and inhibits invasion in human hepatoma cell line HepG2 cells

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    <p>Abstract</p> <p>Background</p> <p>PCBP1 (or alpha CP1 or hnRNP E1), a member of the PCBP family, is widely expressed in many human tissues and involved in regulation of transcription, transportation process, and function of RNA molecules. However, the role of PCBP1 in CD44 variants splicing still remains elusive.</p> <p>Results</p> <p>We found that enforced PCBP1 expression inhibited CD44 variants expression including v3, v5, v6, v8, and v10 in HepG2 cells, and knockdown of endogenous PCBP1 induced these variants splicing. Invasion assay suggested that PCBP1 played a negative role in tumor invasion and re-expression of v6 partly reversed the inhibition effect by PCBP1. A correlation of PCBP1 down-regulation and v6 up-regulation was detected in primary HCC tissues.</p> <p>Conclusions</p> <p>We first characterized PCBP1 as a negative regulator of CD44 variants splicing in HepG2 cells, and loss of PCBP1 in human hepatic tumor contributes to the formation of a metastatic phenotype.</p

    Plasmoid ejection and secondary current sheet generation from magnetic reconnection in laser-plasma interaction

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    Reconnection of the self-generated magnetic fields in laser-plasma interaction was first investigated experimentally by Nilson {\it et al.} [Phys. Rev. Lett. 97, 255001 (2006)] by shining two laser pulses a distance apart on a solid target layer. An elongated current sheet (CS) was observed in the plasma between the two laser spots. In order to more closely model magnetotail reconnection, here two side-by-side thin target layers, instead of a single one, are used. It is found that at one end of the elongated CS a fan-like electron outflow region including three well-collimated electron jets appears. The (>1>1 MeV) tail of the jet energy distribution exhibits a power-law scaling. The enhanced electron acceleration is attributed to the intense inductive electric field in the narrow electron dominated reconnection region, as well as additional acceleration as they are trapped inside the rapidly moving plasmoid formed in and ejected from the CS. The ejection also induces a secondary CS

    Synthesis, spectral characterization and biological activities of phosphoryl amino acid esters

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    Phosphoryl amino acids and phosphoryl amino acid esters, as phosphorus analogs of amino acid, have attracted much attention because they show wide biological activities. In this paper, the tide compounds, 2-isopropoxy-(2-isopropyl-5-methyl-cyclohexyloxy)-phosphoryl amino acid esters, were synthesized in the presence of sulfuryl chloride with reasonable yields. Their structures were confirmed by IR, H-1 NMR, C-13 NMR, P-31 NMR and MS spectra, and the antibacterial and antitumor activities of these compounds were given in this paper

    Prospective, observational, multicenter study on minimally invasive gastrectomy for gastric cancer: robotic, laparoscopic and open surgery compared on operative and follow-up outcomes - IMIGASTRIC II study protocol: IMIGASTRIC II

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    Background:Several meta-analyses have tried to defi ne the role of minimally invasive approaches.&nbsp;However, further evidence to get a wider spread of these methods is necessary. Current&nbsp;studies describe minimally invasive surgery as a possible alternative to open surgery&nbsp;but deserving further clarifi cation. However, despite the increasing interest, the&nbsp;difficulty of planning prospective studies of adequate size accounts for the low level of&nbsp;evidence, which is mostly based on retrospective experiences.A multi-institutional prospective study allows the collection of an impressive amount&nbsp;of data to investigate various aspects of minimally invasive procedures with the&nbsp;opportunity of developing several subgroup analyses.A prospective data collection with high methodological quality on minimally invasive&nbsp;and open gastrectomies can clarify the role of diff erent procedures with the aim to&nbsp;develop specifi c guidelines.Methods and analysis:a multi-institutional prospective database will be established including information on&nbsp;surgical, clinical and oncological features of patients treated for gastric cancer with&nbsp;robotic, laparoscopic or open approaches and subsequent follow-up.The study has been shared by the members of the International study group on&nbsp;Minimally Invasive surgery for GASTRIc Cancer (IMIGASTRIC)The database is designed to be an international electronic submission system and a&nbsp;HIPPA protected real time data repository from high volume gastric cancer centers.Ethics:This study is conducted in compliance with ethical principles originating from the&nbsp;Helsinki Declaration, within the guidelines of Good Clinical Practice and relevantlaws/regulations.Trial registration number:NCT0275108

    Reevaluation of the Value of Autoparasitoids in Biological Control

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    Autoparasitoids with the capacity of consuming primary parasitoids that share the same hosts to produce males are analogous to intraguild predators. The use of autoparasitoids in biological control programs is a controversial matter because there is little evidence to support the view that autoparasitoids do not disrupt and at times may promote suppression of insect pests in combination with primary parasitoids. We found that Encarsia sophia, a facultative autoparasitoid, preferred to use heterospecific hosts as secondary hosts for producing males. The autoparasitoids mated with males originated from heterospecifics may parasitize more hosts than those mated with males from conspecifics. Provided with an adequate number of males, the autoparasitoids killed more hosts than En. formosa, a commonly used parasitoid for biological control of whiteflies. This study supports the view that autoparasitoids in combination with primary parasitoids do not disrupt pest management and may enhance such programs. The demonstrated preference of an autoparasitoid for heterospecifics and improved performance of males from heterospecifics observed in this study suggests these criteria should be considered in strategies that endeavor to mass-produce and utilize autoparasitoids in the future

    Selective Alpha-Particle Mediated Depletion of Tumor Vasculature with Vascular Normalization

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    BACKGROUND: Abnormal regulation of angiogenesis in tumors results in the formation of vessels that are necessary for tumor growth, but compromised in structure and function. Abnormal tumor vasculature impairs oxygen and drug delivery and results in radiotherapy and chemotherapy resistance, respectively. Alpha particles are extraordinarily potent, short-ranged radiations with geometry uniquely suitable for selectively killing neovasculature. METHODOLOGY AND PRINCIPAL FINDINGS: Actinium-225 ((225)Ac)-E4G10, an alpha-emitting antibody construct reactive with the unengaged form of vascular endothelial cadherin, is capable of potent, selective killing of tumor neovascular endothelium and late endothelial progenitors in bone-marrow and blood. No specific normal-tissue uptake of E4G10 was seen by imaging or post-mortem biodistribution studies in mice. In a mouse-model of prostatic carcinoma, (225)Ac-E4G10 treatment resulted in inhibition of tumor growth, lower serum prostate specific antigen level and markedly prolonged survival, which was further enhanced by subsequent administration of paclitaxel. Immunohistochemistry revealed lower vessel density and enhanced tumor cell apoptosis in (225)Ac-E4G10 treated tumors. Additionally, the residual tumor vasculature appeared normalized as evident by enhanced pericyte coverage following (225)Ac-E4G10 therapy. However, no toxicity was observed in vascularized normal organs following (225)Ac-E4G10 therapy. CONCLUSIONS: The data suggest that alpha-particle immunotherapy to neovasculature, alone or in combination with sequential chemotherapy, is an effective approach to cancer therapy
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