139 research outputs found

    The il1β have a protective action in the acute phase of the pilocarpine-induced epilepsy model

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    INTRODUCTION: There is contradictory information regarding the of effects il1β and il1rn in epilepsy. We aimed to evaluate the effect of silencing both genes in the acute phase of the pilocarpine-induced epilepsy model. METHODS: We used RNA interference in order to achieve gene silencing. RESULTS: We obtained significant gene silencing in the central nervous system. In addition, we observed phenotypic effects including differences in mortality rates of animals 5 days after pilocarpine injections. CONCLUSION: Our results indicate that il1β seems to have a protective effect in the acute phase of the pilocarpine-induced epilepsy model.INTRODUÇÃO: Existem contradições na literatura quanto aos efeitos dos genes il1β e il1rn nas epilepsias. Nosso objetivo foi avaliar os efeitos do silenciamento desses dois genes na fase aguda do modelo de epilepsia induzido pela pilocarpina. MÉTODOS: Para alterar a expressão dos genes il1β e il1rn utilizamos a técnica de interferência por RNA. RESULTADOS: Obtivemos taxas de silenciamento significativas para os dois genes no sistema nervoso central. Observamos efeitos fenotípicos significativos, incluindo a alteração na taxa de mortalidade dos animais 5 dias após a indução do modelo. CONCLUSÕES: A il1β parece exercer um papel protetor na fase aguda do modelo de epilepsia induzido pela pilocarpina.979

    Long-Term Prognostic Impact of CT-Leaman Score in Patients with Non-Obstructive CAD: Results from the COronary CT Angiography EvaluatioN For Clinical Outcomes InteRnational Multicenter (CONFIRM) Study

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    BACKGROUND: Non-obstructive coronary artery disease (CAD) identified by coronary computed tomography angiography (CCTA) demonstrated prognostic value. CT-adapted Leaman score (CT-LeSc) showed to improve the prognostic stratification. Aim of the study was to evaluate the capability of CT-LeSc to assess long-term prognosis of patients with non-obstructive (CAD). METHODS: From 17 centers, we enrolled 2402 patients without prior CAD history who underwent CCTA that showed non-obstructive CAD and provided complete information on plaque composition. Patients were divided into a group without CAD and a group with non-obstructive CAD (<50% stenosis). Segment-involvement score (SIS) and CT-LeSc were calculated. Outcomes were non-fatal myocardial infarction (MI) and the combined end-point of MI and all-cause mortality. RESULTS: Patient mean age was 56±12years. At follow-up (mean 59.8±13.9months), 183 events occurred (53 MI, 99 all-cause deaths and 31 late revascularizations). CT-LeSc was the only multivariate predictor of MI (HRs 2.84 and 2.98 in two models with Framingham and risk factors, respectively) and of MI plus all-cause mortality (HR 2.48 and 1.94 in two models with Framingham and risk factors, respectively). This was confirmed by a net reclassification analysis confirming that the CT-LeSc was able to correctly reclassify a significant proportion of patients (cNRI 0.28 and 0.23 for MI and MI plus all-cause mortality, respectively) vs. baseline model, whereas SIS did not. CONCLUSION: CT-LeSc is an independent predictor of major acute cardiac events, improving prognostic stratification of patients with non-obstructive CAD.Dr. Min has served on themedical advisory boards Arineta; He is a consultant to Heart Flowand Cardiovascular Research Foundation; and has received research support from GE Healthcare.info:eu-repo/semantics/publishedVersio

    Automated Nuclear Analysis of Leishmania major Telomeric Clusters Reveals Changes in Their Organization during the Parasite's Life Cycle

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    Parasite virulence genes are usually associated with telomeres. The clustering of the telomeres, together with their particular spatial distribution in the nucleus of human parasites such as Plasmodium falciparum and Trypanosoma brucei, has been suggested to play a role in facilitating ectopic recombination and in the emergence of new antigenic variants. Leishmania parasites, as well as other trypanosomes, have unusual gene expression characteristics, such as polycistronic and constitutive transcription of protein-coding genes. Leishmania subtelomeric regions are even more unique because unlike these regions in other trypanosomes they are devoid of virulence genes. Given these peculiarities of Leishmania, we sought to investigate how telomeres are organized in the nucleus of Leishmania major parasites at both the human and insect stages of their life cycle. We developed a new automated and precise method for identifying telomere position in the three-dimensional space of the nucleus, and we found that the telomeres are organized in clusters present in similar numbers in both the human and insect stages. While the number of clusters remained the same, their distribution differed between the two stages. The telomeric clusters were found more concentrated near the center of the nucleus in the human stage than in the insect stage suggesting reorganization during the parasite's differentiation process between the two hosts. These data provide the first 3D analysis of Leishmania telomere organization. The possible biological implications of these findings are discussed

    A Krill Oil Supplemented Diet Suppresses Hepatic Steatosis in High-Fat Fed Rats

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    Krill oil (KO) is a dietary source of n-3 polyunsaturated fatty acids, mainly represented by eicosapentaenoic acid and docosahexaenoic acid bound to phospholipids. The supplementation of a high-fat diet with 2.5% KO efficiently prevented triglyceride and cholesterol accumulation in liver of treated rats. This effect was accompanied by a parallel reduction of the plasma levels of triglycerides and glucose and by the prevention of a plasma insulin increase. The investigation of the molecular mechanisms of KO action in high-fat fed animals revealed a strong decrease in the activities of the mitochondrial citrate carrier and of the cytosolic acetyl-CoA carboxylase and fatty acid synthetase, which are both involved in hepatic de novo lipogenesis. In these animals a significant increase in the activity of carnitine palmitoyl-transferase I and in the levels of carnitine was also observed, suggesting a concomitant stimulation of hepatic fatty acid oxidation. The KO supplemented animals also retained an efficient mitochondrial oxidative phosphorylation, most probably as a consequence of a KO-induced arrest of the uncoupling effects of a high-fat diet. Lastly, the KO supplementation prevented an increase in body weight, as well as oxidative damage of lipids and proteins, which is often found in high-fat fed animals

    Plasticity of Adult Human Pancreatic Duct Cells by Neurogenin3-Mediated Reprogramming

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    AIMS/HYPOTHESIS: Duct cells isolated from adult human pancreas can be reprogrammed to express islet beta cell genes by adenoviral transduction of the developmental transcription factor neurogenin3 (Ngn3). In this study we aimed to fully characterize the extent of this reprogramming and intended to improve it. METHODS: The extent of the Ngn3-mediated duct-to-endocrine cell reprogramming was measured employing genome wide mRNA profiling. By modulation of the Delta-Notch signaling or addition of pancreatic endocrine transcription factors Myt1, MafA and Pdx1 we intended to improve the reprogramming. RESULTS: Ngn3 stimulates duct cells to express a focused set of genes that are characteristic for islet endocrine cells and/or neural tissues. This neuro-endocrine shift however, is incomplete with less than 10% of full duct-to-endocrine reprogramming achieved. Transduction of exogenous Ngn3 activates endogenous Ngn3 suggesting auto-activation of this gene. Furthermore, pancreatic endocrine reprogramming of human duct cells can be moderately enhanced by inhibition of Delta-Notch signaling as well as by co-expressing the transcription factor Myt1, but not MafA and Pdx1. CONCLUSIONS/INTERPRETATION: The results provide further insight into the plasticity of adult human duct cells and suggest measurable routes to enhance Ngn3-mediated in vitro reprogramming protocols for regenerative beta cell therapy in diabetes

    Identification and Characterisation of Pseudomonas 16S Ribosomal DNA from Ileal Biopsies of Children with Crohn's Disease

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    Molecular analysis of bacterial 16S rRNA genes has made a significant contribution to the identification and characterisation of bacterial flora in the human gut. In particular, this methodology has helped characterise bacterial families implicated in the aetiology of inflammatory bowel disease (IBD). In this study we have used a genus specific bacterial 16S PCR to investigate the prevalence and diversity of Pseudomonas species derived from the ileum of children with Crohn's disease (CD), and from control children with non-inflammatory bowel disease (non-IBD) undergoing their initial endoscopic examination. Fifty eight percent of CD patients (18/32) were positive using the Pseudomonas PCR, while significantly fewer children in the non-IBD group, 33% (12/36), were PCR positive for Pseudomonas (p<0.05, Fischer's exact test). Pseudomonas specific 16S PCR products from 13 CD and 12 non-IBD children were cloned and sequenced. Five hundred and eighty one sequences were generated and used for the comparative analysis of Pseudomonas diversity between CD and non-IBD patients. Pseudomonas species were less diverse in CD patients compared with non-IBD patients. In particular P.aeruginosa was only identified in non-IBD patients

    Direct application of compound-specific radiocarbon analysis of leaf waxes to establish lacustrine sediment chronology

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    Author Posting. © Springer, 2007. This is the author's version of the work. It is posted here by permission of Springer for personal use, not for redistribution. The definitive version was published in Journal of Paleolimnology 39 (2008): 43-60, doi:10.1007/s10933-007-9094-1.This study demonstrates use of compound-specific radiocarbon analysis (CSRA) for dating Holocene lacustrine sediments from carbonate-hosted Ordy Pond, Oahu, Hawaii. Long-chain odd-numbered normal alkanes (n-alkanes), biomarkers characteristic of terrestrial higher plants, were ubiquitous in Ordy Pond sediments. The δ13C of individual n-alkanes ranged from −29.9 to −25.5‰, within the expected range for n-alkanes synthesized by land plants using the C3 or C4 carbon fixation pathway. The 14C ages of n-alkanes determined by CSRA showed remarkably good agreement with 14C dates of rare plant macrofossils obtained from nearby sedimentary horizons. In general, CSRA of n-alkanes successfully refined the age-control of the sediments. The sum of n-alkanes in each sample produced 70–170 μg of carbon (C), however, greater age errors were confirmed for samples containing less than 80 μg of C. The 14C age of n-alkanes from one particular sedimentary horizon was 4,155 years older than the value expected from the refined age-control, resulting in an apparent and arguable age discrepancy. Several lines of evidence suggest that this particular sample was contaminated by introduction of 14C-free C during preparative capillary gas chromatography. This study simultaneously highlighted the promising potential of CSRA for paleo-applications and the risks of contamination associated with micro-scale 14C measurement of individual organic compounds.This project was funded by Petroleum Research Fund (PRF #40088-ACS) and in part by Sigma Xi, The Scientific Research Society (Grants in aid of research, 2003)

    Dimerization of FIR upon FUSE DNA binding suggests a mechanism of c-myc inhibition

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    c-myc is essential for cell homeostasis and growth but lethal if improperly regulated. Transcription of this oncogene is governed by the counterbalancing forces of two proteins on TFIIH—the FUSE binding protein (FBP) and the FBP-interacting repressor (FIR). FBP and FIR recognize single-stranded DNA upstream of the P1 promoter, known as FUSE, and influence transcription by oppositely regulating TFIIH at the promoter site. Size exclusion chromatography coupled with light scattering reveals that an FIR dimer binds one molecule of single-stranded DNA. The crystal structure confirms that FIR binds FUSE as a dimer, and only the N-terminal RRM domain participates in nucleic acid recognition. Site-directed mutations of conserved residues in the first RRM domain reduce FIR's affinity for FUSE, while analogous mutations in the second RRM domain either destabilize the protein or have no effect on DNA binding. Oppositely oriented DNA on parallel binding sites of the FIR dimer results in spooling of a single strand of bound DNA, and suggests a mechanism for c-myc transcriptional control

    Glucosamine and chondroitin sulfate supplementation to treat symptomatic disc degeneration: Biochemical rationale and case report

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    BACKGROUND: Glucosamine and chondroitin sulfate preparations are widely used as food supplements against osteoarthritis, but critics are skeptical about their efficacy, because of the lack of convincing clinical trials and a reasonable scientific rationale for the use of these nutraceuticals. Most trials were on osteoarthritis of the knee, while virtually no documentation exists on spinal disc degeneration. The purpose of this article is to highlight the potential of these food additives against cartilage degeneration in general, and against symptomatic spinal disc degeneration in particular, as is illustrated by a case report. The water content of the intervertebral disc is a reliable measure of its degeneration/ regeneration status, and can be objectively determined by Magnetic Resonance Imaging (MRI) signals. CASE PRESENTATION: Oral intake of glucosamine and chondroitin sulfate for two years associated with disk recovery (brightening of MRI signal) in a case of symptomatic spinal disc degeneration. We provide a biochemical explanation for the possible efficacy of these nutraceuticals. They are bioavailable to cartilage chondrocytes, may stimulate the biosynthesis and inhibit the breakdown of their extracellular matrix proteoglycans. CONCLUSION: The case suggests that long-term glucosamine and chondroitin sulfate intake may counteract symptomatic spinal disc degeneration, particularly at an early stage. However, definite proof requires well-conducted clinical trials with these food supplements, in which disc de-/regeneration can be objectively determined by MRI. A number of biochemical reasons (that mechanistically need to be further resolved) explain why these agents may have cartilage structure- and symptom-modifying effects, suggesting their therapeutic efficacy against osteoarthritis in general

    Estrogen receptor transcription and transactivation: Basic aspects of estrogen action

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    Estrogen signaling has turned out to be much more complex and exciting than previously thought; the paradigm shift in our understanding of estrogen action came in 1996, when the presence of a new estrogen receptor (ER), ERβ, was reported. An intricate interplay between the classical ERα and the novel ERβ is of paramount importance for the final biological effect of estrogen in different target cells
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