498 research outputs found

    Filogenetska analiza dijela gena VP2 pasjeg parvovirusa-2 izdvojenog u sjevernoj Indiji

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    Canine parvovirus-2 (CPV-2) infection is a serious problem causing a high rate of mortality in puppies. Despite the widespread vaccination of domestic dogs, a major impediment in the control of this deadly disease is the presence of different antigenic variants in field. Regular surveillance and constant monitoring of these variants, which might evade the host immune pressure and laboratory detection, is critically essential. Thus, the present study was aimed at understanding the molecular epidemiology of CPV-2 strains circulating in northern region of India. Polymerase Chain Reaction (PCR) positive samples were subjected to oligonucleotide sequencing and these isolates were found to be identical to CPV-2a except at positions 264, 297 and 440 amino acid residue, and thus typed as an antigenic variant of CPV-2a. The mutation at position 264 has not been reported from India before. Furthermore, global phylogenetic analysis confirmed the molecular relationship of these new CPV-2a isolates with sequences from China.Infekcija pasjim parvovirusom 2 predstavlja ozbiljan problem uzrokujući veliki mortalitet u štenadi. Usprkos proširenom cijepljenju pasa, veliku poteškoću u kontroli ove smrtonosne bolesti predstavljaju različite antigenske varijante terenskih izolata virusa. Od bitnog je značenja redoviti nadzor i trajna kontrola tih varijanti koje mogu izbjeći imunski pritisak domaćina i otežati laboratorijsku dijagnostiku. Stoga ovo istraživanje ima za cilj rasvijetliti molekularnu epizootiologiju sojeva pasjeg parvovirusa 2 koji kolaju na sjevernom području Indije. Uzorci pozitivni lančanom reakcijom polimerazom podvrgnuti su oligonukleotidnom sekvencioniranju. Ustanovljeno je da su ti izolati bili identični pasjem parvovirusu 2a, osim na mjestima aminokiselinskog ostatka 264, 297 i 440 što im upravo određuje pripadnost serotipu 2a. Mutacije na mjestu 264 dosada nisu bile opisane u Indiji. Globalnim filogenetskim analizama utvrđena je molekularna srodnost tih novih izolata pasjeg parvovirusa 2a s izolatima iz Kine

    Carbon-Based Nanomaterials as Novel Nanosensors [Editorial]

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    In recent years, nanosensor technology has experienced a rapid development because of the extensive scientific efforts in understanding of nanoscale phenomena and achieving innovative nanofabrication techniques. Carbon-based nanomaterials (CBNs), such as fullerenes, graphene, nanodiamonds, carbon nanotubes, and carbon nanodots, have recently gained considerable attention among scientific communities due to their unique chemical and physical properties. Thanks to intensive research efforts, the CBNs have found their place in a wide range of applications. These CBNs stand out as novel nanosensors due to their supreme performance in detecting heavy metal ions, gas molecules, food additives, antibodies, and toxic pesticides, as well as reporters for bioimaging. This special issue, to be published in 2017, addresses recent progress in the synthesis, characterization, structure-property relationships and applications of CBNs as novel nanosensors. We are confident that the accrual of these contributions will facilitate the applications of CBNs as innovative nanosensors in meeting the urgent needs for environmental monitoring, food safety control, healthcare, homeland security, and so forth. We have selected five papers, representing four different frontiers of this topic: graphene, silver nanoparticles, carbon nanotubes, and carbon nanodots

    The architecture and ppGpp-dependent expression of the primary transcriptome of Salmonella Typhimurium during invasion gene expression

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    <p>Abstract</p> <p>Background</p> <p>Invasion of intestinal epithelial cells by <it>Salmonella enterica </it>serovar Typhimurium (<it>S</it>. Typhimurium) requires expression of the extracellular virulence gene expression programme (ST<sup>EX</sup>), activation of which is dependent on the signalling molecule guanosine tetraphosphate (ppGpp). Recently, next-generation transcriptomics (RNA-seq) has revealed the unexpected complexity of bacterial transcriptomes and in this report we use differential RNA sequencing (dRNA-seq) to define the high-resolution transcriptomic architecture of wild-type <it>S</it>. Typhimurium and a ppGpp null strain under growth conditions which model ST<sup>EX</sup>. In doing so we show that ppGpp plays a much wider role in regulating the <it>S</it>. Typhimurium ST<sup>EX </sup>primary transcriptome than previously recognised.</p> <p>Results</p> <p>Here we report the precise mapping of transcriptional start sites (TSSs) for 78% of the <it>S</it>. Typhimurium open reading frames (ORFs). The TSS mapping enabled a genome-wide promoter analysis resulting in the prediction of 169 alternative sigma factor binding sites, and the prediction of the structure of 625 operons. We also report the discovery of 55 new candidate small RNAs (sRNAs) and 302 candidate antisense RNAs (asRNAs). We discovered 32 ppGpp-dependent alternative TSSs and determined the extent and level of ppGpp-dependent coding and non-coding transcription. We found that 34% and 20% of coding and non-coding RNA transcription respectively was ppGpp-dependent under these growth conditions, adding a further dimension to the role of this remarkable small regulatory molecule in enabling rapid adaptation to the infective environment.</p> <p>Conclusions</p> <p>The transcriptional architecture of <it>S</it>. Typhimurium and finer definition of the key role ppGpp plays in regulating <it>Salmonella </it>coding and non-coding transcription should promote the understanding of gene regulation in this important food borne pathogen and act as a resource for future research.</p

    Sodium and its manifold impact on our immune system

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    The Western diet is rich in salt, and a high salt diet (HSD) is suspected to be a risk factor for cardiovascular diseases. It is now widely accepted that an experimental HSD can stimulate components of the immune system, potentially exacerbating certain autoimmune diseases, or alternatively, improving defenses against certain infections, such as cutaneous leishmaniasis. However, recent findings show that an experimental HSD may also aggravate other infections (e.g., pyelonephritis or systemic listeriosis). Here, we discuss the modulatory effects of a HSD on the microbiota, metabolic signaling, hormonal responses, local sodium concentrations, and their effects on various immune cell types in different tissues. We describe how these factors are integrated, resulting either in immune stimulation or suppression in various tissues and disease settings

    High-Fat Diet: Bacteria Interactions Promote Intestinal Inflammation Which Precedes and Correlates with Obesity and Insulin Resistance in Mouse

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    Obesity induced by high fat (HF) diet is associated with inflammation which contributes to development of insulin resistance. Most prior studies have focused on adipose tissue as the source of obesity-associated inflammation. Increasing evidence links intestinal bacteria to development of diet-induced obesity (DIO). This study tested the hypothesis that HF western diet and gut bacteria interact to promote intestinal inflammation, which contributes to the progression of obesity and insulin resistance.Conventionally raised specific-pathogen free (CONV) and germ-free (GF) mice were given HF or low fat (LF) diet for 2-16 weeks. Body weight and adiposity were measured. Intestinal inflammation was assessed by evaluation of TNF-alpha mRNA and activation of a NF-kappaB(EGFP) reporter gene. In CONV but not GF mice, HF diet induced increases in body weight and adiposity. HF diet induced ileal TNF-alpha mRNA in CONV but not GF mice and this increase preceded obesity and strongly and significantly correlated with diet induced weight gain, adiposity, plasma insulin and glucose. In CONV mice HF diet also resulted in activation of NF-kappaB(EGFP) in epithelial cells, immune cells and endothelial cells of small intestine. Further experiments demonstrated that fecal slurries from CONV mice fed HF diet are sufficient to activate NF-kappaB(EGFP) in GF NF-kappaB(EGFP) mice.Bacteria and HF diet interact to promote proinflammatory changes in the small intestine, which precede weight gain and obesity and show strong and significant associations with progression of obesity and development of insulin resistance. To our knowledge, this is the first evidence that intestinal inflammation is an early consequence of HF diet which may contribute to obesity and associated insulin resistance. Interventions which limit intestinal inflammation induced by HF diet and bacteria may protect against obesity and insulin resistance

    Toll-Like Receptor 9-Dependent Macrophage Activation by Entamoeba histolytica DNA

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    Activation of the innate immune system by bacterial DNA and DNA of other invertebrates represents a pathogen recognition mechanism. In this study we investigated macrophage responses to DNA from the intestinal protozoan parasite Entamoeba histolytica. E. histolytica genomic DNA was purified from log-phase trophozoites and tested with the mouse macrophage cell line RAW 264.7. RAW cells treated with E. histolytica DNA demonstrated an increase in levels of tumor necrosis factor alpha (TNF-α) mRNA and protein production. TNF-α production was blocked by pretreatment with chloroquine or monensin. In fact, an NF-κB luciferase reporter assay in HEK cells transfected with human TLR9 demonstrated that E. histolytica DNA signaled through Toll-like receptor 9 (TLR9) in a manner similar to that seen with CpG-ODN. Immunofluorescence assays confirmed NF-κB activation in RAW cells, as seen by nuclear translocation of the p65 subunit. Western blot analysis demonstrated mitogen-activated protein kinase activation by E. histolytica DNA. E. histolytica DNA effects were abolished in MYD88−/− mouse-derived macrophages. In the context of disease, immunization with E. histolytica DNA protected gerbils from an E. histolytica challenge infection. Taken together, these results demonstrate that E. histolytica DNA is recognized by TLR9 to activate macrophages and may provide an innate defense mechanism characterized by the induction of the inflammatory mediator TNF-α

    GSK3β inhibition blocks melanoma cell/host interactions by downregulating N-cadherin expression and decreasing FAK phosphorylation.

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    This study addresses the role of glycogen synthase kinase (GSK)-3β signaling in the tumorigenic behavior of melanoma. Immunohistochemical staining revealed GSK3β to be focally expressed in the invasive portions of 12 and 33% of primary and metastatic melanomas, respectively. GSK3 inhibitors and small interfering RNA (siRNA) knockdown of GSK3β were found to inhibit the motile behavior of melanoma cells in scratch wound, three-dimensional collagen-implanted spheroid, and modified Boyden chamber assays. Functionally, inhibition of GSK3β signaling was found to suppress N-cadherin expression at the messenger RNA and protein levels, and was associated with decreased expression of the transcription factor Slug. Pharmacological and genetic ablation of GSK3β signaling inhibited the adhesion of melanoma cells to both endothelial cells and fibroblasts and prevented transendothelial migration, an effect rescued by the forced overexpression of N-cadherin. A further role for GSK3β signaling in invasion was suggested by the ability of GSK3β inhibitors and siRNA knockdown to block phosphorylation of focal adhesion kinase (FAK) and increase the size of focal adhesions. In summary, we have, to our knowledge, demonstrated a previously unreported role for GSK3β in modulating the motile and invasive behavior of melanoma cells through N-cadherin and FAK. These studies suggest the potential therapeutic utility of inhibiting GSK3β in defined subsets of melanoma

    Mass-to-light ratio gradients in early-type galaxy haloes

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    Since the near future should see a rapidly expanding set of probes of the halo masses of individual early-type galaxies, we introduce a convenient parameter for characterising the halo masses from both observational and theoretical results: \dML, the logarithmic radial gradient of the mass-to-light ratio. Using halo density profiles from LCDM simulations, we derive predictions for this gradient for various galaxy luminosities and star formation efficiencies ϵSF\epsilon_{SF}. As a pilot study, we assemble the available \dML\ data from kinematics in early-type galaxies - representing the first unbiassed study of halo masses in a wide range of early-type galaxy luminosities - and find a correlation between luminosity and \dML, such that the brightest galaxies appear the most dark-matter dominated. We find that the gradients in most of the brightest galaxies may fit in well with the LCDM predictions, but that there is also a population of fainter galaxies whose gradients are so low as to imply an unreasonably high star formation efficiency ϵSF>1\epsilon_{SF} > 1. This difficulty is eased if dark haloes are not assumed to have the standard LCDM profiles, but lower central concentrations.Comment: 17 pages, 13 figures. Accepted for publication on MNRA
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