122 research outputs found

    CMB Observations: improvements of the performance of correlation radiometers by signal modulation and synchronous detection

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    Observation of the fine structures (anisotropies, polarization, spectral distortions) of the Cosmic Microwave Background (CMB) is hampered by instabilities, 1/f noise and asymmetries of the radiometers used to carry on the measurements. Addition of modulation and synchronous detection allows to increase the overall stability and the noise rejection of the radiometers used for CMB studies. In this paper we discuss the advantages this technique has when we try to detect CMB polarization. The behaviour of a two channel correlation receiver to which phase modulation and synchronous detection have been added is examined. Practical formulae for evaluating the improvements are presented.Comment: 18 pages, 3 figures, New Astronomy accepte

    Activation of the Heat Shock Factor 1 by Serine Protease Inhibitors AN EFFECT ASSOCIATED WITH NUCLEAR FACTOR-ÎşB INHIBITION

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    Heat shock proteins (HSPs) have a cytoprotective role in several human diseases, including ischemia and viral infection. Nuclear factor-kappaB (NF-kappaB) is a critical regulator of inflammation and virus replication. Here we report that a class of serine protease inhibitors with NF-kappaB-inhibitory activity are potent HSP inducers via activation of heat shock transcription factor 1 (HSF1) in human cells. 3,4-Dichloroisocoumarin, the most effective compound, rapidly induces HSF1 DNA binding activity and phosphorylation, leading to transcription and translation of heat shock genes for a period of several hours. HSF1 activation is independent of de novo protein synthesis and is correlated in a concentration- and time-dependent manner with NF-kappaB inhibition. Cysteine protease inhibitors E64 and calpain inhibitor II, which do not block NF-kappaB activation, do not induce HSF DNA binding activity. HSP induction by 3,4-dichloroisocoumarin is associated with antiviral activity during rhabdovirus infection. These results identify a new class of HSP inducers and indicate a link between the regulatory pathways of HSF and NF-kappaB, suggesting novel strategies to simultaneously switch on cytoprotective genes and down-regulate inflammatory and viral genes

    Inhibition of HSP70 expression by calcium ionophore A23187 in human cells. An effect independent of the acquisition of DNA-binding activity by the heat shock transcription factor

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    Heat shock proteins (HSPs) are induced in mammalian cells in a variety of pathophysiological states and have an important role in cytoprotection in vitro and in vivo. In this study, we report that the calcium ionophore A23187, a glucose-regulated protein (GRP) inducer, dramatically inhibits HSP70 synthesis and HSP70 mRNA transcription after induction by heat shock, sodium arsenite, or prostaglandin A1 treatment in human K562 cells. A23187 does not suppress, and it actually prolongs, the DNA-binding activity of the human heat shock transcription factor (HSF), while it alters HSF1 phosphorylation in heat shock-treated cells. To inhibit HSP70 expression, A23187 needs to be present during heat shock, while treatment before or after heat shock does not affect HSP70 mRNA transcription. The GRP inducer thapsigargin, which specifically inhibits the endoplasmic reticulum Ca2+-ATPase, has no effect on heat-induced HSP70 synthesis, indicating that A23187 inhibitory activity is not due to depletion of intracellular calcium stores and is independent of the concomitant induction of GRP genes. Inhibition of HSP70 expression is correlated with alterations in HSF1 phosphorylation in heat-shocked cells, but not in sodium arsenite-treated cells, indicating that different mechanisms may be involved in mediating A23187 inhibitory activity

    Comparative Proteomic Profiling of Divergent Phenotypes for Water Holding Capacity across the Post Mortem Ageing Period in Porcine Muscle Exudate

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    peer-reviewedTwo dimensional Difference Gel Electrophoresis (2-D DIGE) and mass spectrometry were applied to investigate the changes in metabolic proteins that occur over a seven day (day 1, 3 and 7) post mortem ageing period in porcine centrifugal exudate from divergent meat quality phenotypes. The objectives of the research were to enhance our understanding of the phenotype (water holding capacity) and search for biomarkers of this economically significant pork quality attribute. Major changes in protein abundance across nine phenotype-by-time conditions were observed. Proteomic patterns were dominated by post mortem ageing timepoint. Using a machine learning algorithm (l1-regularized logistic regression), a model was derived with the ability to discriminate between high drip and low drip phenotypes using a subset of 25 proteins with an accuracy of 63%. Models discriminating between divergent phenotypes with accuracy of 72% and 73% were also derived comparing respectively, high drip plus intermediate phenotype (considered as one phenotype) versus low drip and comparing low drip plus intermediate phenotype (considered as one phenotype) versus high drip. In all comparisons, the general classes of discriminatory proteins identified include metabolic enzymes, stress response, transport and structural proteins. In this research we have enhanced our understanding of the protein related processes underpinning this phenotype and provided strong data to work toward development of protein biomarkers for water holding capacity.This research was funded through the Irish National Development Plan through the Food Institutional Research Measure of the Department of Food Agriculture and the Marine, Project 06RDNUIG470

    Preclinical evaluation of IL2-based immunocytokines supports their use in combination with dacarbazine, paclitaxel and TNF-based immunotherapy

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    Antibody-cytokine fusion proteins ("immunocytokines”) represent a promising class of armed antibody products, which allow the selective delivery of potent pro-inflammatory payloads at the tumor site. The antibody-based selective delivery of interleukin-2 (IL2) is particularly attractive for the treatment of metastatic melanoma, an indication for which this cytokine received marketing approval from the US Food and drug administration. We used the K1735M2 immunocompetent syngeneic model of murine melanoma to study the therapeutic activity of F8-IL2, an immunocytokine based on the F8 antibody in diabody format, fused to human IL2. F8-IL2 was shown to selectively localize at the tumor site in vivo, following intravenous administration, and to mediate tumor growth retardation, which was potentiated by the combination with paclitaxel or dacarbazine. Combination treatment led to a substantially more effective tumor growth inhibition, compared to the cytotoxic drugs used as single agents, without additional toxicity. Analysis of the immune infiltrate revealed a significant accumulation of CD4+ T cells 24h after the administration of the combination. The fusion proteins F8-IL2 and L19-IL2, specific to the alternatively spliced extra domain A and extra domain B of fibronectin respectively, were also studied in combination with tumor necrosis factor (TNF)-based immunocytokines. The combination treatment was superior to the action of the individual immunocytokines and was able to eradicate neoplastic lesions after a single intratumoral injection, a procedure that is being clinically used for the treatment of Stage IIIC melanoma. Collectively, these data reinforce the rationale for the use of IL2-based immunocytokines in combination with cytotoxic agents or TNF-based immunotherapy for the treatment of melanoma patients

    Non-hematologic toxicity of bortezomib in multiple myeloma: the neuromuscular and cardiovascular adverse effects

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    The overall approach to the treatment of multiple myeloma (MM) has undergone several changes during the past decade. and proteasome inhibitors (PIs) including bortezomib, carfilzomib, and ixazomib have considerably improved the outcomes in affected patients. The first-in-class selective PI bortezomib has been initially approved for the refractory forms of the disease but has now become, in combination with other drugs, the backbone of the frontline therapy for newly diagnosed MM patients, as well as in the maintenance therapy and relapsed/refractory setting. Despite being among the most widely used and highly effective agents for MM, bortezomib can induce adverse events that potentially lead to early discontinuation of the therapy with negative effects on the quality of life and outcome of the patients. Although peripheral neuropathy and myelosuppression have been recognized as the most relevant bortezomib-related adverse effects, cardiac and skeletal muscle toxicities are relatively common in MM treated patients, but they have received much less attention. Here we review the neuromuscular and cardiovascular side effects of bortezomib. focusing on the molecular mechanisms underlying its toxicity. We also discuss our preliminary data on the effects of bortezomib on skeletal muscle tissue in mice receiving the drug

    Simultaneous idiopathic segmental infarction of the great omentum and acute appendicitis: a rare association

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    Idiopathic segmental infarction of the greater omentum is an uncommon cause of acute abdomen. The etiology is still unclear and the symptoms mimic acute appendicitis. Its presentation simultaneously with acute appendicitis is still more infrequent. We present a case of a 47-year old woman without significant previous medical history, admitted with an acute abdomen, in which the clinical diagnosis was acute appendicitis and in whom an infarcted segment of right side of the greater omentum was also found at laparotomy. As the etiology is unknown, we highlighted some of the possible theories, and emphasize the importance of omental infarction even in the presence of acute appendicitis as a coincident intraperitoneal pathological condition

    A novel in-frame deletion in MYOT causes an early adult onset distal myopathy

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    Missense mutations in MYOT encoding the sarcomeric Z-disk protein myotilin cause three main myopathic phenotypes including proximal limb-girdle muscular dystrophy, spheroid body myopathy, and late-onset distal myopathy. We describe a family carrying a heterozygous MYOT deletion (Tyr4_His9del) that clinically was characterized by an early-adult onset distal muscle weakness and pathologically by a myofibrillar myopathy (MFM). Molecular modeling of the full-length myotilin protein revealed that the 4-YERPKH-9 amino acids are involved in local interactions within the N-terminal portion of myotilin. Injection of in vitro synthetized mutated human MYOT RNA or of plasmid carrying its cDNA sequence in zebrafish embryos led to muscle defects characterized by sarcomeric disorganization of muscle fibers and widening of the I-band, and severe motor impairments. We identify MYOT novel Tyr4_His9 deletion as the cause of an early-onset MFM with a distal myopathy phenotype and provide data supporting the importance of the amino acid sequence for the structural role of myotilin in the sarcomeric organization of myofibers

    Whole-exome sequencing in patients with protein aggregate myopathies reveals causative mutations associated with novel atypical phenotypes

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    BACKGROUND: Myofibrillar myopathies (MFM) are a subgroup of protein aggregate myopathies (PAM) characterized by a common histological picture of myofibrillar dissolution, Z-disk disintegration, and accumulation of degradation products into inclusions. Mutations in genes encoding components of the Z-disk or Z-disk-associated proteins occur in some patients whereas in most of the cases, the causative gene defect is still unknown. We aimed to search for pathogenic mutations in genes not previously associated with MFM phenotype.METHODS: We performed whole-exome sequencing in four patients from three unrelated families who were diagnosed with PAM without aberrations in causative genes for MFM.RESULTS: In the first patient and her affected daughter, we identified a heterozygous p.(Arg89Cys) missense mutation in LMNA gene which has not been linked with PAM pathology before. In the second patient, a heterozygous p.(Asn4807Phe) mutation in RYR1 not previously described in PAM represents a novel, candidate gene with a possible causative role in the disease. Finally, in the third patient and his symptomatic daughter, we found a previously reported heterozygous p.(Cys30071Arg) mutation in TTN gene that was clinically associated with cardiac involvement.CONCLUSIONS: Our study identifies a new genetic background in PAM pathology and expands the clinical phenotype of known pathogenic mutations

    Integrated forest management to prevent wildfires under Mediterranean environments

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    This review presents a multidisciplinary framework for integrating the ecological, regulatory, procedural and technical aspects of forest management for fi res prevention under Mediterranean environments. The aims are to: i) provide a foreground of wildfi re scenario; ii) illustrate the theoretical background of forest fuel management; iii) describe the available fuel management techniques and mechanical operations for fi re prevention in forest and wildland-urban interfaces, with exemplifi cation of case-studies; iv)allocate fi re prevention activities under the hierarchy of forest planning. The review is conceived as an outline commentary discussion targeted to professionals, technicians and government personnel involved in forestry and environmental management
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