38 research outputs found

    Pump-induced platelet aggregation in albumin-coated extracorporeal systems

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    AbstractObjective: Coating of extracorporeal systems with heparin does not prevent platelet activation and subsequent bleeding disorders. We investigated whether this could be due to elevated shear stress caused by a roller pump. Methods: Human or rat blood was made to flow through an uncoated or an albumin-coated medical polyvinyl chloride tube with or without a roller pump. Aggregation of platelets in the tubing was recorded continuously with a photometric device. Results: Although in vitro gravitational flow in uncoated tubes caused immediate platelet aggregation and platelet loss, this remained absent in coated tubes. When the pump was started in experiments with a coated tube strong platelet aggregation was observed and platelet count fell within 5 minutes to 78% ± 2% and 71% ± 3% of control values in human and rat blood, respectively. In vivo, no aggregation was observed during spontaneous flow in rats with an albumin-coated tube running from the carotid artery to the femoral artery, but aggregation started as soon as the blood was pumped. Pump-induced platelet aggregation, both in vitro and in vivo, could be prevented with aurintricarboxylic acid, which specifically inhibits shear-induced platelet aggregation as has recently been shown. Pump perfusion of blood in an uncoated tube did not elicit platelet aggregation. Conclusions: Pump perfusion of blood in coated systems elicits shear-induced platelet aggregation, which may be prevented by administration of substances that block the binding of von Willebrand factor to glycoprotein Ib receptors on the platelets. The effects of pumping on platelets are masked in uncoated circuits because of the dominant influence of blood-material contact. (J Thorac Cardiovasc Surg 1999;118:946-52

    Mapping Arginase Expression with <sup>18</sup>F-Fluorinated Late-Generation Arginase Inhibitors Derived from Quaternary α-Amino Acids

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    Arginase hydrolyzes L-arginine and influences levels of polyamines and nitric oxide. Arginase overexpression is associated with inflammation and tumorigenesis. Thus, radiolabeled arginase inhibitors may be suitable PET tracers for staging arginase-related pathophysiologies. We report the synthesis and evaluation of 2 radiolabeled arginase inhibitors, 18F-FMARS and 18F-FBMARS, developed from α-substituted-2-amino-6-boronohexanoic acid derivatives. Methods: Arylboronic ester-derived precursors were radiolabeled via copper-mediated fluorodeboronation. Binding assays using arginase-expressing PC3 and LNCaP cells were performed. Autoradiography of lung sections from a guinea pig model of asthma overexpressing arginase and dynamic small-animal PET imaging with PC3-xenografted mice evaluated the radiotracers' specific binding and pharmacokinetics. Results:18F-fluorinated compounds were obtained with radiochemical yields of up to 5% (decay-corrected) and an average molar activity of 53 GBqâ‹…ÎŒmol-1 Cell and lung section experiments indicated specific binding that was blocked up to 75% after pretreatment with arginase inhibitors. Small-animal PET studies indicated fast clearance of the radiotracers (7.3 ± 0.6 min), arginase-mediated uptake, and a selective tumor accumulation (SUV, 3.0 ± 0.7). Conclusion: The new 18F-fluorinated arginase inhibitors have the potential to map increased arginase expression related to inflammatory and tumorigenic processes. 18F-FBMARS showed the highest arginase-mediated uptake in PET imaging and a significant difference between uptake in control and arginase-inhibited PC3 xenografted mice. These results encourage further research to examine the suitability of 18F-FBMARS for selecting patients for treatments with arginase inhibitors

    Glycerophosphodiesterase GDE2 Promotes Neuroblastoma Differentiation through Glypican Release and Is a Marker of Clinical Outcome

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    Neuroblastoma is a pediatric embryonal malignancy characterized by impaired neuronal differentiation. A better understanding of neuroblastoma differentiation is essential for developing new therapeutic approaches. GDE2 (encoded by GDPD5) is a six-transmembrane-domain glycerophosphodiesterase that promotes embryonic neurogenesis. We find that high GDPD5 expression is strongly associated with favorable outcome in neuroblastoma. GDE2 induces differentiation of neuroblastoma cells, suppresses cell motility, and opposes RhoA-driven neurite retraction. GDE2 alters the Rac-RhoA activity balance and the expression of multiple differentiation-associated genes. Mechanistically, GDE2 acts by cleaving (in cis) and releasing glycosylphosphatidylinositol-anchored glypican-6, a putative co-receptor. A single point mutation in the ectodomain abolishes GDE2 function. Our results reveal GDE2 as a cell-autonomous inducer of neuroblastoma differentiation with prognostic significance and potential therapeutic value.</p

    Effectiveness of life skills training on increasing self-esteem of high school students

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    AbstractObjective This study designed to investigate effectiveness of training life skills on adolescents’ students. Method This study is a pseudo-experimental study which accomplished on 160 students in Karaj city. Subjects of the study selected randomly from list of students in all of the schools of Karaj; then they divided randomly in two groups. Trained counsellors taught the life skills to students of the study group, and 80 reminder subjects assigned as control group. After educating the training program, subjects administered Cooper Smith self-esteem questionnaire (58-items version). Results Findings of the study indicated that life skills training lead to significant increase of self-esteem in study group in contrast to control group subjects. Conclusion Psycho education and mental health programs such as life skills training could cause to increase the necessary skills in students and decline school and educational problems

    Biological and Clinical Implications of Gene-Expression Profiling in Diffuse Large B-Cell Lymphoma:A Proposal for a Targeted BLYM-777 Consortium Panel as Part of a Multilayered Analytical Approach

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    Gene-expression profiling (GEP) is used to study the molecular biology of lymphomas. Here, advancing insights from GEP studies in diffuse large B-cell lymphoma (DLBCL) lymphomagenesis are discussed. GEP studies elucidated subtypes based on cell-of-origin principles and profoundly changed the biological understanding of DLBCL with clinical relevance. Studies integrating GEP and next-generation DNA sequencing defined different molecular subtypes of DLBCL entities originating at specific anatomical localizations. With the emergence of high-throughput technologies, the tumor microenvironment (TME) has been recognized as a critical component in DLBCL pathogenesis. TME studies have characterized so-called “lymphoma microenvironments" and “ecotypes”. Despite gained insights, unexplained chemo-refractoriness in DLBCL remains. To further elucidate the complex biology of DLBCL, we propose a novel targeted GEP consortium panel, called BLYM-777. This knowledge-based biology-driven panel includes probes for 777 genes, covering many aspects regarding B-cell lymphomagenesis (f.e., MYC signature, TME, immune surveillance and resistance to CAR T-cell therapy). Regarding lymphomagenesis, upcoming DLBCL studies need to incorporate genomic and transcriptomic approaches with proteomic methods and correlate these multi-omics data with patient characteristics of well-defined and homogeneous cohorts. This multilayered methodology potentially enhances diagnostic classification of DLBCL subtypes, prognostication, and the development of novel targeted therapeutic strategies. Simple Summary: This review summarizes gene-expression profiling insights into the background and origination of diffuse large B-cell lymphomas (DLBCL). To further unravel the molecular biology of these lymphomas, a consortium panel called BLYM-777 was designed including genes important for subtype classifications, genetic pathways, tumor-microenvironment, immune response and resistance to targeted therapies. This review proposes to combine this transcriptomic method with genomics, proteomics, and patient characteristics to facilitate diagnostic classification, prognostication, and the development of new targeted therapeutic strategies in DLBCL

    Study protocol for a multicenter randomized controlled trial to compare the efficacy of end-ischemic dual hypothermic oxygenated machine perfusion with static cold storage in preventing non-anastomotic biliary strictures after transplantation of liver grafts donated after circulatory death: DHOPE-DCD trial

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    Background: The major concern in liver transplantation of grafts from donation after circulatory death (DCD) donors remains the high incidence of non-anastomotic biliary strictures (NAS). Machine perfusion has been proposed as an alternative strategy for organ preservation which reduces ischemia-reperfusion injury (IRI). Experimental studies have shown that dual hypothermic oxygenated machine perfusion (DHOPE) is associated with less IRI, improved hepatocellular function, and better preserved mitochondrial and endothelial function compared to conventional static cold storage (SCS). Moreover, DHOPE was safely applied with promising results in a recently performed phase-1 study. The aim of the current study is to determine the efficacy of DHOPE in reducing the incidence of NAS after DCD liver transplantation. Methods: This is an international multicenter randomized controlled trial. Adult patients (≄18 yrs. old) undergoing transplantation of a DCD donor liver (Maastricht category III) will be randomized between the intervention and control group. In the intervention group, livers will be subjected to two hours of end-ischemic DHOPE after SCS and before implantation. In the control group, livers will be subjected to care as usual with conventional SCS only. Primary outcome is the incidence of symptomatic NAS diagnosed by a blinded adjudication committee. In all patients, magnetic resonance cholangiography will be obtained at six months after transplantation. Discussion: DHOPE is associated with reduced IRI of the bile ducts. Whether reduced IRI of the bile ducts leads to lower incidence of NAS after DCD liver transplantation can only be examined in a randomized controlled trial. Trial registration: The trial was registered in Clinicaltrials.gov in September 2015 with the identifier NCT02584283

    Blood Pressure During Endovascular Treatment Under Conscious Sedation or Local Anesthesia

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    OBJECTIVE: To evaluate the role of blood pressure (BP) as mediator of the effect of conscious sedation (CS) compared to local anesthesia (LA) on functional outcome after endovascular treatment (EVT). METHODS: Patients treated in the Multicenter Randomized Clinical Trial of Endovascular Treatment for Acute Ischemic Stroke in the Netherlands (MR CLEAN) Registry centers with CS or LA as preferred anesthetic approach during EVT for ischemic stroke were analyzed. First, we evaluated the effect of CS on area under the threshold (AUT), relative difference between baseline and lowest procedural mean arterial pressure (∆LMAP), and procedural BP trend, compared to LA. Second, we assessed the association between BP and functional outcome (modified Rankin Scale [mRS]) with multivariable regression. Lastly, we evaluated whether BP explained the effect of CS on mRS. RESULTS: In 440 patients with available BP data, patients treated under CS (n = 262) had larger AUTs (median 228 vs 23 mm Hg*min), larger ∆LMAP (median 16% vs 6%), and a more negative BP trend (-0.22 vs -0.08 mm Hg/min) compared to LA (n = 178). Larger ∆LMAP and AUTs were associated with worse mRS (adjusted common odds ratio [acOR] per 10% drop 0.87, 95% confidence interval [CI] 0.78-0.97, and acOR per 300 mm Hg*min 0.89, 95% CI 0.82-0.97). Patients treated under CS had worse mRS compared to LA (acOR 0.59, 95% CI 0.40-0.87) and this association remained when adjusting for ∆LMAP and AUT (acOR 0.62, 95% CI 0.42-0.92). CONCLUSIONS: Large BP drops are associated with worse functional outcome. However, BP drops do not explain the worse outcomes in the CS group

    Genome sequencing and analysis of the versatile cell factory Aspergillus niger CBS 513.88

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    The filamentous fungus Aspergillus niger is widely exploited by the fermentation industry for the production of enzymes and organic acids, particularly citric acid. We sequenced the 33.9-megabase genome of A. niger CBS 513.88, the ancestor of currently used enzyme production strains. A high level of synteny was observed with other aspergilli sequenced. Strong function predictions were made for 6,506 of the 14,165 open reading frames identified. A detailed description of the components of the protein secretion pathway was made and striking differences in the hydrolytic enzyme spectra of aspergilli were observed. A reconstructed metabolic network comprising 1,069 unique reactions illustrates the versatile metabolism of A. niger. Noteworthy is the large number of major facilitator superfamily transporters and fungal zinc binuclear cluster transcription factors, and the presence of putative gene clusters for fumonisin and ochratoxin A synthesis

    Genetic variation at CYP3A is associated with age at menarche and breast cancer risk : a case-control study

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    Abstract Introduction We have previously shown that a tag single nucleotide polymorphism (rs10235235), which maps to the CYP3A locus (7q22.1), was associated with a reduction in premenopausal urinary estrone glucuronide levels and a modest reduction in risk of breast cancer in women age ≀50 years. Methods We further investigated the association of rs10235235 with breast cancer risk in a large case control study of 47,346 cases and 47,570 controls from 52 studies participating in the Breast Cancer Association Consortium. Genotyping of rs10235235 was conducted using a custom Illumina Infinium array. Stratified analyses were conducted to determine whether this association was modified by age at diagnosis, ethnicity, age at menarche or tumor characteristics. Results We confirmed the association of rs10235235 with breast cancer risk for women of European ancestry but found no evidence that this association differed with age at diagnosis. Heterozygote and homozygote odds ratios (ORs) were OR = 0.98 (95% CI 0.94, 1.01; P = 0.2) and OR = 0.80 (95% CI 0.69, 0.93; P = 0.004), respectively (P trend = 0.02). There was no evidence of effect modification by tumor characteristics. rs10235235 was, however, associated with age at menarche in controls (P trend = 0.005) but not cases (P trend = 0.97). Consequently the association between rs10235235 and breast cancer risk differed according to age at menarche (P het = 0.02); the rare allele of rs10235235 was associated with a reduction in breast cancer risk for women who had their menarche age ≄15 years (ORhet = 0.84, 95% CI 0.75, 0.94; ORhom = 0.81, 95% CI 0.51, 1.30; P trend = 0.002) but not for those who had their menarche age ≀11 years (ORhet = 1.06, 95% CI 0.95, 1.19, ORhom = 1.07, 95% CI 0.67, 1.72; P trend = 0.29). Conclusions To our knowledge rs10235235 is the first single nucleotide polymorphism to be associated with both breast cancer risk and age at menarche consistent with the well-documented association between later age at menarche and a reduction in breast cancer risk. These associations are likely mediated via an effect on circulating hormone levels

    Toll-like receptor 4-induced interleukin-1 defines the intestinal microbiome and mucosal immune response in arthritis-prone IL-1 receptor antagonist deficient mice

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    Background: Mice deficient in interleukin-1 receptor antagonist (IL-1Ra-/-) spontaneously develop a T cell-driven autoimmune arthritis, which we previously showed to depend on the presence of commensal microbiota. Recent findings suggest alteration of intestinal microbiome in new-onset rheumatoid arthritis (RA). Objectives: The aim of this study was to investigate the role of IL-1 receptor signaling and Toll-like receptor (TLR) 2 and TLR4 in defining the intestinal microbiota and the associated mucosal and systemic immune response during arthritis. Methods: Multiplex 454 pyrosequencing of fecal bacterial 16S rRNA was used to define intestinal microbial communities in BALB/c wild type (WT), IL-1Ra-/- and IL-1Ra/TLR double knock-out (DKO) mice. For gene sequencing analysis, a customized workflow based on Quantitative Insights Into Microbial Ecology (QIIME version 1.2) was adopted. T cell differentiation was assessed in small intestine lamina propria (SI-LP) and spleen using flow cytometry and gene expression was assessed by qPCR. Results: IL-1Ra-/- mice had a significant reduction in microbial diversity compared to WT mice. Both alpha diversity (number of unique taxonomic entities) and phylogenetic diversity (PD) whole tree (based on taxonomic distance) were significantly diminished in IL-1Ra-/- mice. Interestingly, the loss of species diversity was absent in IL-1Ra/TLR4 DKO, but not IL-1Ra/TLR2 DKO mice, suggesting that IL-1R-driven skewing of bacterial diversity depends on TLR4. IL-1Ra-/- mice exhibited significantly increased abundance of the genus Helicobacter and reduced Prevotella (p=0.008 and p =0.004, respectively). Importantly, significant alterations in the genera Xylanibacter, Prevotella, Streptococcus, and Ruminococcus were markedly normalized in TLR4, but not TLR2, deficient mice, identifying a role for TLR4 in IL-1 mediated shifts in microbial community. In line with the relevance of intestinal microbiota in mucosal T cell polarization, IL-1Ra-/- mice had greatly increased Th17 in SI-LP. Interestingly, SI-LP Th17% significantly correlated with arthritis score. Although intestinal mRNA expression of IL-1 itself remained unaltered, IL-23p19 expression was increased. Both IL-1b and IL-23 were significantly diminished in IL-1Ra/TLR4 DKO mice, suggesting a TLR4-mediated regulation. These mucosal responses paralleled systemic response and arthritis development, since Th17% and associated genes such as RORÎłt were increased in IL-1Ra-/- and reduced in IL-1Ra/TLR4 DKO mice which had less severe arthritis. Conclusions: These data suggest a TLR4-mediated regulation of intestinal microbiome, and mucosal and splenic immune responses controlling arthritis severity, potentially through an IL-1 and IL-23 dependent mechanism. Understanding the molecular and cellular mechanisms linking the intestinal T cell response with arthritis may help identifying novel therapeutic targets in RA
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