478 research outputs found

    Supplementation of diet with krill oil protects against experimental rheumatoid arthritis

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    <p>Abstract</p> <p>Background</p> <p>Although the efficacy of standard fish oil has been the subject of research in arthritis, the effect of krill oil in this disease has yet to be investigated. The objective of the present study was to evaluate a standardised preparation of krill oil and fish oil in an animal model for arthritis.</p> <p>Methods</p> <p>Collagen-induced arthritis susceptible DBA/1 mice were provided <it>ad libitum </it>access to a control diet or diets supplemented with either krill oil or fish oil throughout the study. There were 14 mice in each of the 3 treatment groups. The level of EPA + DHA was 0.44 g/100 g in the krill oil diet and 0.47 g/100 g in the fish oil diet. Severity of arthritis was determined using a clinical scoring system. Arthritis joints were analysed by histopathology and graded. Serum samples were obtained at the end of the study and the levels of IL-1α, IL-1β, IL-7, IL-10, IL-12p70, IL-13, IL-15, IL-17 and TGF-β were determined by a Luminex™ assay system.</p> <p>Results</p> <p>Consumption of krill oil and supplemented diet significantly reduced the arthritis scores and hind paw swelling when compared to a control diet not supplemented with EPA and DHA. However, the arthritis score during the late phase of the study was only significantly reduced after krill oil administration. Furthermore, mice fed the krill oil diet demonstrated lower infiltration of inflammatory cells into the joint and synovial layer hyperplasia, when compared to control. Inclusion of fish oil and krill oil in the diets led to a significant reduction in hyperplasia and total histology score. Krill oil did not modulate the levels of serum cytokines whereas consumption of fish oil increased the levels of IL-1α and IL-13.</p> <p>Conclusions</p> <p>The study suggests that krill oil may be a useful intervention strategy against the clinical and histopathological signs of inflammatory arthritis.</p

    Peripheral Effects of FAAH Deficiency on Fuel and Energy Homeostasis: Role of Dysregulated Lysine Acetylation

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    FAAH (fatty acid amide hydrolase), primarily expressed in the liver, hydrolyzes the endocannabinoids fatty acid ethanolamides (FAA). Human FAAH gene mutations are associated with increased body weight and obesity. In our present study, using targeted metabolite and lipid profiling, and new global acetylome profiling methodologies, we examined the role of the liver on fuel and energy homeostasis in whole body FAAH(-/-) mice.FAAH(-/-) mice exhibit altered energy homeostasis demonstrated by decreased oxygen consumption (Indirect calorimetry). FAAH(-/-) mice are hyperinsulinemic and have adipose, skeletal and hepatic insulin resistance as indicated by stable isotope phenotyping (SIPHEN). Fed state skeletal muscle and liver triglyceride levels was increased 2-3 fold, while glycogen was decreased 42% and 57% respectively. Hepatic cholesterol synthesis was decreased 22% in FAAH(-/-) mice. Dysregulated hepatic FAAH(-/-) lysine acetylation was consistent with their metabolite profiling. Fasted to fed increases in hepatic FAAH(-/-) acetyl-CoA (85%, p<0.01) corresponded to similar increases in citrate levels (45%). Altered FAAH(-/-) mitochondrial malate dehydrogenase (MDH2) acetylation, which can affect the malate aspartate shuttle, was consistent with our observation of a 25% decrease in fed malate and aspartate levels. Decreased fasted but not fed dihydroxyacetone-P and glycerol-3-P levels in FAAH(-/-) mice was consistent with a compensating contribution from decreased acetylation of fed FAAH(-/-) aldolase B. Fed FAAH(-/-) alcohol dehydrogenase (ADH) acetylation was also decreased.Whole body FAAH deletion contributes to a pre-diabetic phenotype by mechanisms resulting in impairment of hepatic glucose and lipid metabolism. FAAH(-/-) mice had altered hepatic lysine acetylation, the pattern sharing similarities with acetylation changes reported with chronic alcohol treatment. Dysregulated hepatic lysine acetylation seen with impaired FAA hydrolysis could support the liver's role in fostering the pre-diabetic state, and may reflect part of the mechanism underlying the hepatic effects of endocannabinoids in alcoholic liver disease mouse models

    Perceptions, attitudes and knowledge of evidence-based medicine in primary care in Spain: a study protocol

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    <p>Abstract</p> <p>Background</p> <p>The philosophy of evidence-based medicine (EBM) was introduced in the early 90s as a new approach to the practice of medicine, using the best available evidence to make decisions about health care. Despite ongoing controversy, EBM has developed enormously and physicians' attitude towards it is generally positive. Nevertheless, in Spain little is known about this topic. We will therefore undertake a study to explore perceptions, attitudes and knowledge about EBM among primary care physicians.</p> <p>Methods and design</p> <p>A mixed-method study combining qualitative and quantitative designs will target family practitioners in Spain with the objective of evaluating current attitudes and perceptions about evidence-based medicine. The project will consist of two phases: a first phase running focus groups to identify perceptions and attitudes of participants, and a second phase assessing their attitudes and knowledge about EBM by means of a survey. Both phases will explore these issues in three different subgroups: family practitioners, with or without previous formal education in EBM; members of working groups that formulate healthcare recommendations; and physicians in charge of training family practice residents. Additionally, we will undertake a systematic review to identify and synthesize the available evidence on this topic.</p> <p>Discussion</p> <p>The study will identify and gain insight into the perceived problems and barriers to the practice of evidence-based medicine among general practitioners in Spain. The project will also evaluate the main knowledge gaps and training needs, and explore how evidence-based medicine is being taught to family medicine residents, the medical practitioners of the future. Our results will aid researchers and health care planners in developing strategies to improve the practice of evidence-based medicine in our country.</p

    Bilateral inhibition of HAUSP deubiquitinase by a viral interferon regulatory factor protein

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    Herpesvirus-associated ubiquitin specific protease (HAUSP) regulates the stability of p53 and MDM2, implicating HAUSP as a therapeutic target for tuning p53-mediated anti-tumor activity. Here, we report the structural analysis of HAUSP with Kaposi’s sarcoma-associated herpesvirus vIRF4 and the discovery of two vIRF4-derived peptides, vif1 and vif2, as potent and selective HAUSP antagonists. This analysis reveals a bilateral belt-type interaction resulting in inhibition of HAUSP. The vif1 peptide binds the HAUSP TRAF domain, competitively blocking substrate binding, while the vif2 peptide binds both the HAUSP TRAF and catalytic domains, robustly suppressing its deubiquitination activity. Consequently, peptide treatments comprehensively blocked HAUSP, leading to p53-dependent cell cycle arrest and apoptosis in culture and tumor regression in xenograft mouse model. Thus, the virus has developed a unique molecular strategy to target the HAUSP-MDM2-p53 pathway, and these virus-derived short peptides represent biologically active HAUSP antagonists

    Probiotic treatment reduces appetite and glucose level in the zebrafish model.

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    The gut microbiota regulates metabolic pathways that modulate the physiological state of hunger or satiety. Nutrients in the gut stimulate the release of several appetite modulators acting at central and peripheral levels to mediate appetite and glucose metabolism. After an eight-day exposure of zebrafish larvae to probiotic Lactobacillus rhamnosus, high-throughput sequence analysis evidenced the ability of the probiotic to modulate the microbial composition of the gastrointestinal tract. These changes were associated with a down-regulation and up-regulation of larval orexigenic and anorexigenic genes, respectively, an up-regulation of genes related to glucose level reduction and concomitantly reduced appetite and body glucose level. BODIPY-FL-pentanoic-acid staining revealed higher short chain fatty acids levels in the intestine of treated larvae. These results underline the capability of the probiotic to modulate the gut microbiota community and provides insight into how the probiotic interacts to regulate a novel gene network involved in glucose metabolism and appetite control, suggesting a possible role for L. rhamnosus in the treatment of impaired glucose tolerance and food intake disorders by gut microbiota manipulation

    Ciprofloxacin induces apoptosis and inhibits proliferation of human colorectal carcinoma cells

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    Efficacy of chemotherapy in advanced stages of colorectal tumours is limited. The quinolone antibiotic ciprofloxacin was recently shown to inhibit growth and to induce apoptosis in human bladder carcinomas cells. We investigated the effect of ciprofloxacin on colon carcinoma lines in vitro. CC-531, SW-403 and HT-29 colon carcinoma and HepG2 hepatoma cells (control cells) were exposed to ciprofloxacin. Proliferation was assessed by bromodeoxyuridine-incorporation into DNA and apoptosis was measured by flow cytometry after propidium iodide or JC-1 staining. Expression of anti-apoptotic Bcl-2 and pro-apoptotic Bax was analyzed by semiquantitative Western blot analysis and activity of caspases 3, 8 and 9 by substrate-cleavage assays. Ciprofloxacin suppressed DNA synthesis of all colon carcinoma cells time- and dose-dependently, whereas the hepatoma cells remained unaffected. Apoptosis reached its maximum between 200 and 500 μg ml−1. This was accompanied by an upregulation of Bax and of the activity of caspases 3, 8 and 9, and paralleled by a decrease of the mitochondrial membrane potential. Ciprofloxacin decreases proliferation and induces apoptosis of colon carcinoma cells, possibly in part by blocking mitochondrial DNA synthesis. Therefore, qualification of ciprofloxacin as adjunctive agent for colorectal cancer should be evaluated

    Hepatitis C Virus Induces the Cannabinoid Receptor 1

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    BACKGROUND: Activation of hepatic CB(1) receptors (CB(1)) is associated with steatosis and fibrosis in experimental forms of liver disease. However, CB(1) expression has not been assessed in patients with chronic hepatitis C (CHC), a disease associated with insulin resistance, steatosis and metabolic disturbance. We aimed to determine the importance and explore the associations of CB(1) expression in CHC. METHODS: CB(1) receptor mRNA was measured by real time quantitative PCR on extracted liver tissue from 88 patients with CHC (genotypes 1 and 3), 12 controls and 10 patients with chronic hepatitis B (CHB). The Huh7/JFH1 Hepatitis C virus (HCV) cell culture model was used to validate results. PRINCIPAL FINDINGS: CB(1) was expressed in all patients with CHC and levels were 6-fold higher than in controls (P<0.001). CB(1) expression increased with fibrosis stage, with cirrhotics having up to a 2 fold up-regulation compared to those with low fibrosis stage (p<0.05). Even in mild CHC with no steatosis (F0-1), CB(1) levels remained substantially greater than in controls (p<0.001) and in those with mild CHB (F0-1; p<0.001). Huh7 cells infected with JFH-1 HCV showed an 8-fold upregulation of CB(1), and CB(1) expression directly correlated with the percentage of cells infected over time, suggesting that CB(1) is an HCV inducible gene. While HCV structural proteins appear essential for CB(1) induction, there was no core genotype specific difference in CB(1) expression. CB(1) significantly increased with steatosis grade, primarily driven by patients with genotype 3 CHC. In genotype 3 patients, CB(1) correlated with SREBP-1c and its downstream target FASN (SREBP-1c; R=0.37, FASN; R=0.39, p<0.05 for both). CONCLUSIONS/SIGNIFICANCE: CB(1) is up-regulated in CHC and is associated with increased steatosis in genotype 3. It is induced by the hepatitis C virus

    Alterations in LMTK2, MSMB and HNF1B gene expression are associated with the development of prostate cancer

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    <p>Abstract</p> <p>Background</p> <p>Genome wide association studies (GWAS) have identified several genetic variants that are associated with prostate cancer. Most of these variants, like other GWAS association signals, are located in non-coding regions of potential candidate genes, and thus could act at the level of the mRNA transcript.</p> <p>Methods</p> <p>We measured the expression and isoform usage of seven prostate cancer candidate genes in benign and malignant prostate by real-time PCR, and correlated these factors with cancer status and genotype at the GWAS risk variants.</p> <p>Results</p> <p>We determined that levels of <it>LMTK2 </it>transcripts in prostate adenocarcinomas were only 32% of those in benign tissues (p = 3.2 × 10<sup>-7</sup>), and that an independent effect of genotype at variant rs6465657 on <it>LMTK2 </it>expression in benign (n = 39) and malignant tissues (n = 21) was also evident (P = 0.002). We also identified that whilst <it>HNF1B(C) </it>and <it>MSMB2 </it>comprised the predominant isoforms in benign tissues (90% and 98% of total <it>HNF1B </it>or <it>MSMB </it>expression)<it>, HNF1B(B) and MSMB1 </it>were predominant in malignant tissue (95% and 96% of total <it>HNF1B </it>or <it>MSMB </it>expression; P = 1.7 × 10<sup>-7 </sup>and 4 × 10<sup>-4 </sup>respectively), indicating major shifts in isoform usage.</p> <p>Conclusions</p> <p>Our results indicate that the amount or nature of mRNA transcripts expressed from the <it>LMTK2</it>, <it>HNF1B </it>and <it>MSMB </it>candidate genes is altered in prostate cancer, and provides further evidence for a role for these genes in this disorder. The alterations in isoform usage we detect highlights the potential importance of alternative mRNA processing and moderation of mRNA stability as potentially important disease mechanisms.</p

    Infection of CD8+CD45RO+ Memory T-Cells by HIV-1 and Their Proliferative Response

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    CD8+ T-cells are involved in controlling HIV-1 infection by eliminating infected cells and secreting soluble factors that inhibit viral replication. To investigate the mechanism and significance of infection of CD8+ T-cells by HIV-1 in vitro, we examined the susceptibility of these cells and their subsets to infection. CD8+ T-cells supported greater levels of replication with T-cell tropic strains of HIV-1, though viral production was lower than that observed in CD4+ T-cells. CD8+ T-cell infection was found to be productive through ELISA, RT-PCR and flow cytometric analyses. In addition, the CD8+CD45RO+ memory T-cell population supported higher levels of HIV-1 replication than CD8+CD45RA+ naïve T-cells. However, infection of CD8+CD45RO+ T-cells did not affect their proliferative response to the majority of mitogens tested. We conclude, with numerous lines of evidence detecting and measuring infection of CD8+ T-cells and their subsets, that this cellular target and potential reservoir may be central to HIV-1 pathogenesis
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