218 research outputs found

    Effect of Rickettsiella viridis endosymbionts introduced into Myzus persicae aphids on parasitism by Diaeretiella rapae:A combined strategy for aphid control?

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    Aphids are major crop pests in southeastern regions of Australia. Some aphid species harbor heritable facultative endosymbionts that may induce beneficial or detrimental impacts on aphids under certain ecological conditions. Aphid-parasitoid interactions can be greatly affected by facultative endosymbionts but there is still limited research on many species of economic significance. Here we assessed the effects of a facultative endosymbiont, Ricketsiella viridis, on parasitism of the major aphid pest, Myzus persicae, by Diaeretiella rapae. We found that R. viridis does not provide M. persicae with significant protection against D. rapae, with parasitoids showing a preference for probing aphids infected with R. viridis. The fecundity of M. persicae is reduced due to infection with R. viridis regardless of the presence of parasitoids. Moreover, we show that parasitoids may facilitate horizontal and subsequent vertical transmission of facultative endosymbionts in aphids which could increase the spread of deleterious effects associated with R. viridis. Based on these findings, simultaneous release of D. rapae and M. persicae infected with R. viridis in the early cropping season (lower population densities and cooler conditions) may contribute to an effective strategy for efficient management of this pest.</p

    4-(4-Chloro­phen­yl)-1-(2-hydr­oxy-2,2-di­phenyl­acet­yl)thio­semicarbazide

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    The asymmetric unit of the title compound, C21H18ClN3O2S, contains two mol­ecules in which the bond lengths and angles are almost identical. Intra­molecular N—H⋯S hydrogen bonds result in the formation of two five-membered rings. In the crystal structure, inter­molecular N—H⋯O hydrogen bonds link the mol­ecules into centrosymmetric dimers; these dimers are linked via inter­molecular O—H⋯S hydrogen bonds, leading to infinite corrugated layers parallel to the bc plane through R 2 2(16) ring motifs

    gamma-Diimine palladium(II) based complexes mediated polymerization of methyl methacrylate

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    The synthesis of new palladium(II) complexes of the type [Pd(A-N=C-ph-C=N-A) Cl-2] (4a-e) (A = cyclohexyl (a), 2-isoprpropyl (b), pyrenyl (c), naphthyl (d), and 2,6-diisopropyl (e)) is described. The isolated gamma-diimine ligands and their corresponding palladium(II) complexes were characterized by their physical properties, elemental analysis, H-1 NMR=, C-13 NMR, and infrared spectroscopy. The palladium(II) complexes (4a-e) were employed successfully as catalysts for atom transfer radical polymerization (ATRP) of methyl methacrylate (MMA) in the presence of ethyl-2-bromoisobutyrate (EBIB) as initiator at 90 degrees C. Polymerization with these catalyst systems afforded polymers with low molecular weight distribution (M-w/M-n) and syndio-rich atactic poly (MMA) with relatively higher [rr] diads. (C) 2013 Production and hosting by Elsevier B.V.Peer reviewe

    Host immune response modulation in avian coronavirus infection : tracheal transcriptome profiling in vitro and in vivo

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    Infectious bronchitis virus (IBV) is a highly contagious Gammacoronavirus causing moderate to severe respiratory infection in chickens. Understanding the initial antiviral response in the respiratory mucosa is crucial for controlling viral spread. We aimed to characterize the impact of IBV Delmarva (DMV)/1639 and IBV Massachusetts (Mass) 41 at the primary site of infection, namely, in chicken tracheal epithelial cells (cTECs) in vitro and the trachea in vivo. We hypothesized that some elements of the induced antiviral responses are distinct in both infection models. We inoculated cTECs and infected young specific pathogen-free (SPF) chickens with IBV DMV/1639 or IBV Mass41, along with mock-inoculated controls, and studied the transcriptome using RNA-sequencing (RNA-seq) at 3 and 18 h post-infection (hpi) for cTECs and at 4 and 11 days post-infection (dpi) in the trachea. We showed that IBV DMV/1639 and IBV Mass41 replicate in cTECs in vitro and the trachea in vivo, inducing host mRNA expression profiles that are strain- and time-dependent. We demonstrated the different gene expression patterns between in vitro and in vivo tracheal IBV infection. Ultimately, characterizing host–pathogen interactions with various IBV strains reveals potential mechanisms for inducing and modulating the immune response during IBV infection in the chicken trachea

    Targeting neuroinflammation for therapeutic intervention in neurodegenerative pathologies: A role for the peptide analogue of thymulin (PAT)

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    Introduction: Inflammation has a vital task in protecting the organism, but when deregulated, it can have serious pathological consequences. The central nervous system (CNS) is capable of mounting immune and inflammatory responses, albeit different from that observed in the periphery. Neuroinflammation, however, can be a major contributor to neurodegenerative diseases and constitute a major challenge for medicine and basic research. Areas covered: Both innate and adaptive immune responses normally play an important role in homeostasis within the CNS. Microglia, astrocytes and neuronal cells express a wide array of toll-like receptors (TLR) that can be upregulated by infection, trauma, injuries and various exogenic or endogenic factors. Chronic hyper activation of brain immune cells can result in neurotoxic actions due to excessive production of several pro-inflammatory mediators. Several studies have recently described an important role for targeting receptors such as nicotinic receptors located on cells in the CNS or in other tissues for the control of inflammation. Expert opinion: Thymulin and its synthetic peptide analogue (PAT) appear to exert potent anti-inflammatory effects at the level of peripheral tissues as well as at the level of the brain. This effect involves, at least partially, the activation of cholinergic mechanisms. © 2012 Informa UK, Ltd

    Arrhythmogenic calmodulin E105A mutation alters cardiac RyR2 regulation leading to cardiac dysfunction in zebrafish

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    Calmodulin (CaM) is a universal calcium (Ca2+)‐binding messenger that regulates many vital cellular events. In cardiac muscle, CaM associates with ryanodine receptor 2 (RyR2) and regulates excitation–contraction coupling. Mutations in human genes CALM1, CALM2, and CALM3 have been associated with life‐threatening heart disorders, such as long QT syndrome (LQTS) and catecholaminergic polymorphic ventricular tachycardia. A novel de novo LQTS‐associated missense CaM mutation (E105A) was recently identified in a 6‐year‐old boy, who experienced an aborted first episode of cardiac arrest. Herein, we report the first molecular characterization of the CaM E105A mutation. Expression of the CaM E105A mutant in zebrafish embryos resulted in cardiac arrhythmia and increased heart rate, suggestive of ventricular tachycardia. In vitro biophysical and biochemical analysis revealed that E105A confers a deleterious effect on protein stability and a reduced Ca2+‐binding affinity due to loss of cooperativity. Finally, the CaM E105A mutation resulted in reduced CaM–RyR2 interaction and defective modulation of ryanodine binding. Our findings suggest that the CaM E105A mutation dysregulates normal cardiac function by a complex mechanism involving alterations in both CaM–Ca2+ and CaM–RyR2 interactions

    Novel palladium(II) and platinum(II) complexes with a fluoropiperazinyl based ligand exhibiting high cytotoxicity and anticancer activity in vitro

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    cis-Dichloro-palladium(II) and cis-dichloro-platinum(II) complexes (2, 4) of the general formula [M(N-N)Cl2] (M=Pd(II) and Pt(II), N-N= 1,2-diamino-4-fluoro-5-(4-methyl-1-piperazinyl) benzene, (DFMPB)) and the dicationic palladium(II) complex [Pd(N-N)(CH3CN)2](BF4)2 (3) have been prepared and characterized by elemental analysis, 1H-NMR-, mass spectroscopy, and IR spectroscopy. The cytotoxic effect of these complexes against MDA-231 and MCF-7 human breast cancer cell lines and K562 human leukemia cell line has been studied. The influence was dose dependent and varies with cell type. The palladium(II) complex (2) showed superior cytotoxic effect compared with the corresponding platinum(II) complex and the standard, cisplatin, when tested against all the above cell lines. 2016 Kayed A. Abu-Safieh et al.Scopu

    Factors that influence a patient’s decision to engage in genetic research

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    IntroductionThe most challenging step in clinical research studies is patient recruitment. Many research studies do not reach their targets because of participant rejection. The purpose of this study was to assess patient as well as the community knowledge, motivation, and barriers to participate in genetic research.MethodsA cross-section study was conducted between September 2018 and February 2020 using face-to-face interviews with candidate patients from outpatient clinics at King Fahad Medical City (KFMC), Riyadh, Saudi Arabia. Additionally, an online survey was conducted to assess the community’s knowledge, motivation and barriers to participate in genetic research studies.ResultsIn total, 470 patients were interviewed for this study, with 341 being successfully recruited for the face to face interview, and the other patients being refused owing to time constraints. The majority percentage of the respondents were females. The respondents’ mean age was 30, and 52.6% reported having a college degree. The survey results from 388 participants illustrated that around 90% of the participants, participated voluntarily due to a good understanding of genetics studies. The majority held positive attitudes toward being part of genetic research, which exceeded the reported motivation score of &gt;75%. The survey indicated that &gt;90% of individuals were willing to participate to acquire therapeutic benefits or to receive continued aftercare. However, 54.6% of survey participants were worried about the side effects and the risks involved in genetic testing. A higher proportion (71.4%) of respondents reported that lack of knowledge about genetic research was one of the barriers to rejecting participation.ConclusionRespondents reported relatively high motivation and knowledge for participation in genetic research. However, study participants reported “do not know enough about genetic research” and “lack of time during clinic visit” as a barrier for participation in genetic research
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