Interconnecting Federated Clouds by Using Publish-Subscribe Service

Cloud Federation is an emerging computing model where multiple resources from independent Cloud providers are leveraged to create large-scale distributed virtual computing clusters, operating as into a single Cloud organization. This model enables the implementation of environmental diversity for Cloud applications, and overcomes the provisioning and scalability limits of a single Cloud, by introducing minimal additional cost for the Cloud consumer. In such a scenario, it is necessary to leverage on specific networking technologies that enable the effective support of inter-Cloud communication services between Cloud providers. This paper proposes an interconnection solution for Cloud federations based on publish/subscribe services. Moreover, we discuss some fundamental concerns needed to satisfy the inter-Cloud communication requirements in terms of reliability and availability. Finally, we present some experimental results that highlight some key reliability and denial of service vulnerability concerns in this domain.     

Detection of Tissue Factor Antigen and Coagulation Activity in Coronary Artery Thrombi Isolated from Patients with ST-Segment Elevation Acute Myocardial Infarction

Introduction

Although ruptured atherosclerotic plaques have been extensively analyzed, the composition of thrombi causing arterial occlusion in patients with ST-segment elevation acute myocardial infarction has been less thoroughly investigated. We sought to investigate whether coagulant active tissue factor can be retrieved in thrombi of patients with STEMI undergoing primary percutaneous coronary intervention.

Methods

Nineteen patients with ST-segment elevation acute myocardial infarction referred for primary percutaneous coronary intervention were enrolled in this study. Coronary thrombi aspirated from coronary arteries were routinely processed for paraffin embedding and histological evaluation (4 patients) or immediately snap frozen for evaluation of tissue factor activity using a modified aPTT test (15 patients). Immunoprecipitation followed by immunoblotting was also performed in 12 patients.

Results

Thrombi aspirated from coronary arteries showed large and irregular areas of tissue factor staining within platelet aggregates, and in close contact with inflammatory cells. Some platelet aggregates stained positive for tissue factor, whereas others did not. Monocytes consistently stained strongly for tissue factor, neutrophils had a more variable and irregular tissue factor staining, and red blood cells did not demonstrate staining for tissue factor. Median clotting time of plasma samples containing homogenized thrombi incubated with a monoclonal antibody that specifically inhibits tissue factor-mediated coagulation activity (mAb 5G9) were significantly longer than their respective controls (88.9 seconds versus 76.5 seconds, respectively; p<0.001). Tissue factor was also identified by immunoprecipitation in 10 patients, with significant variability among band intensities.

Conclusions

Active tissue factor is present in coronary artery thrombi of patients with ST-segment elevation acute myocardial infarction, suggesting that it contributes to activate the coagulation cascade ensuing in coronary thrombosis.     

MicroRNA-486-3p Regulates γ-Globin Expression in Human Erythroid Cells by Directly Modulating BCL11A

MicroRNAs (miRNAs) play key roles in modulating a variety of cellular processes through repression of mRNAs target. The functional relevance of microRNAs has been proven in normal and malignant hematopoiesis. While analyzing miRNAs expression profile in unilineage serum-free liquid suspension unilineage cultures of peripheral blood CD34⁺ hematopoietic progenitor cells (HPCs) through the erythroid, megakaryocytic, granulocytic and monocytic pathways, we identified miR-486-3p as mainly expressed within the erythroid lineage. We showed that miR-486-3p regulates BCL11A expression by binding to the extra-long isoform of BCL11A 3′UTR. Overexpression of miR-486-3p in erythroid cells resulted in reduced BCL11A protein levels, associated to increased expression of γ-globin gene, whereas inhibition of physiological miR-486-3p levels increased BCL11A and, consequently, reduced γ-globin expression. Thus, miR-486-3p regulating BCL11A expression might contributes to fetal hemoglobin (HbF) modulation and arise the question as to what extent this miRNA might contribute to different HbF levels observed among β-thalassemia patients. Erythroid cells, differentiated from PB CD34⁺ cells of a small cohort of patients affected by major or intermedia β-thalassemia, showed miR-486-3p levels significantly higher than those observed in normal counterpart. Importantly, in these patients, miR-486-3p expression correlates with increased HbF synthesis. Thus, our data indicate that miR-486-3p might contribute to different HbF levels observed among thalassemic patients and, possibly, to the clinical severity of the disease.     

Identifying Correlations between Chromosomal Proximity of Genes and Distance of Their Products in Protein-Protein Interaction Networks of Yeast

In this article we present evidence for a relationship between chromosome gene loci and the topological properties of the protein-protein interaction network corresponding to the set of genes under consideration. Specifically, for each chromosome of the Saccharomyces cerevisiae genome, the distribution of the intra-chromosome inter-gene distances was analyzed and a positive correlation with the distance among the corresponding proteins of the protein-protein interaction network was found. In order to study this relationship we used concepts based on non-parametric statistics and information theory.We provide statistical evidence that if two genes are closely located, then it is likely that their protein products are closely located in the protein-protein interaction network, or in other words, that they are involved in the same biological process.     

Long-term survival and immunological parameters in metastatic melanoma patients who responded to ipilimumab 10 mg/kg within an expanded access programme

Background

Ipilimumab can result in durable clinical responses among patients with advanced melanoma. However, no predictive marker of clinical activity has yet been identified. We provide preliminary data describing the correlation between immunological parameters and response/survival among patients with advanced melanoma who received ipilimumab 10 mg/kg in an expanded access programme.

Methods

Patients received ipilimumab 10 mg/kg every 3 weeks (Q3W) for four doses (induction) and Q12W from week 24 (W24) as maintenance therapy. Tumor assessments were conducted Q12W. Expression of inducible T cell costimulator (ICOS) on CD4⁺ and CD8⁺ T cells was assessed at baseline, W7, W12 and W24, and the ratio between absolute neutrophils (N) and lymphocytes (L) determined at baseline, W4, W7 and W10.

Results

Median overall survival among 27 patients was 9.6 months (95 % CI 3.2–16.1), with 3- and 4-year survival rates of 20.4 %. Five patients survived >4 years. Patients with an increase in the number of circulating ICOS⁺ T cells at W7 were more likely to experience disease control and have improved survival. An N/L ratio below the median at W7 and W10 was also associated with better survival compared with an N/L ratio above the median.

Conclusions

Ipilimumab can induce long-term survival benefits in heavily pretreated patients with metastatic melanoma. Changes in the number of circulating ICOS⁺ T cells or N/L ratio during ipilimumab treatment may represent early markers of response. However, given the limited sample size, further investigation is required.     

New Type of Outer Membrane Vesicle Produced by the Gram-Negative Bacterium Shewanella vesiculosa M7T: Implications for DNA Content

Outer membrane vesicles (OMVs) from Gram-negative bacteria are known to be involved in lateral DNA transfer, but the presence of DNA in these vesicles has remained difficult to explain. An ultrastructural study of the Antarctic psychrotolerant bacterium Shewanella vesiculosa M7^T has revealed that this Gram-negative bacterium naturally releases conventional one-bilayer OMVs through a process in which the outer membrane is exfoliated and only the periplasm is entrapped, together with a more complex type of OMV, previously undescribed, which on formation drag along inner membrane and cytoplasmic content and can therefore also entrap DNA. These vesicles, with a double-bilayer structure and containing electron-dense material, were visualized by transmission electron microscopy (TEM) after high-pressure freezing and freeze-substitution (HPF-FS), and their DNA content was fluorometrically quantified as 1.8 ± 0.24 ng DNA/μg OMV protein. The new double-bilayer OMVs were estimated by cryo-TEM to represent 0.1% of total vesicles. The presence of DNA inside the vesicles was confirmed by gold DNA immunolabeling with a specific monoclonal IgM against double-stranded DNA. In addition, a proteomic study of purified membrane vesicles confirmed the presence of plasma membrane and cytoplasmic proteins in OMVs from this strain. Our data demonstrate the existence of a previously unobserved type of double-bilayer OMV in the Gram-negative bacterium Shewanella vesiculosa M7^T that can incorporate DNA, for which we propose the name outer-inner membrane vesicle (O-IMV).     

Response to metal stress of Nicotiana langsdorffii plants wild-type and transgenic for the rat glucocorticoid receptor gene

Recently our findings have shown that the integration of the gene coding for the rat gluco-corticoid receptor (GR receptor) in Nicotiana langsdorffii plants induced morphophysiological effects in transgenic plants through the modification of their hormonal pattern. Phytohormones play a key role in plant responses to many different biotic and abiotic stresses since a modified hormonal profile up-regulates the activation of secondary metabolites involved in the response to stress. In this work transgenic GR plants and isogenic wild type genotypes were exposed to metal stress by treating them with 30 ppm cadmium(II) or 50 ppm chromium(VI). Hormonal patterns along with changes in key response related metabolites were then monitored and compared. Heavy metal up-take was found to be lower in the GR plants. The transgenic plants exhibited higher values of S-abscisic acid (S-ABA) and 3-indole acetic acid (IAA), salicylic acid and total polyphenols, chlorogenic acid and antiradical activity, compared to the untransformed wild type plants. Both Cd and Cr treatments led to an increase in hormone concentrations and secondary metabolites only in wild type plants. Analysis of the results suggests that the stress responses due to changes in the plant's hormonal system may derive from the interaction between the GR receptor and phytosteroids, which are known to play a key role in plant physiology and development.     

Comparative characterization of novel ene‐reductases from cyanobacteria

The growing importance of biocatalysis in the syntheses of enantiopure molecules results from the benefits of enzymes regarding selectivity and specificity of the reaction and ecological issues of the process. Ene‐reductases (ERs) from the old yellow enzyme family have received much attention in the last years. These flavo‐enzymes catalyze the trans‐specific reduction of activated C?C bonds, which is an important reaction in asymmetric synthesis, because up to two stereogenic centers can be created in one reaction. However, limitations of ERs described in the literature such as their moderate catalytic activity and their strong preference for NADPH promote the search for novel ERs with improved properties. In this study, we characterized nine novel ERs from cyanobacterial strains belonging to different taxonomic orders and habitats. ERs were identified with activities towards a broad spectrum of alkenes. The reduction of maleimide was catalyzed with activities of up to 35.5 U mg^?1 using NADPH. Ketoisophorone and (R)‐carvone, which were converted to the highly valuable compounds (R)‐levodione and (2R,5R)‐dihydrocarvone, were reduced with reaction rates of up to 2.2 U mg^?1 with NADPH. In contrast to other homologous ERs from the literature, NADH was accepted at moderate to high rates as well: Enzyme activities of up to 16.7 U mg^?1 were obtained for maleimide and up to 1.3 U mg^?1 for ketoisophorone and (R)‐carvone. Additionally, excellent stereoselectivities were achieved in the reduction of (R)‐carvone (97–99% de). In particular, AnabaenaER3 from Anabaena variabilis ATCC 29413 and AcaryoER1 from Acaryochloris marina MBIC 11017 were identified as useful biocatalysts. Therefore, novel ERs from cyanobacteria with high catalytic efficiency were added to the toolbox for the asymmetric reduction of alkenes. Biotechnol. Bioeng. 2013; 110: 1293–1301. © 2012 Wiley Periodicals, Inc.