811 research outputs found

    Acellular Injectable Biomaterials for Treating Cardiovascular Disease

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    In the last decade, the field of tissue engineering has emerged as a potential therapeutic strategy for the regeneration and/or repair of various tissues afflicted by cardiovascular disease, such as myocardial infarction (MI) or peripheral artery disease (PAD). Among the different tissue engineering strategies, injectable hydrogels have been extensively studied and show encouraging results in both small and large animal models. An injectable hydrogel provides a favorable microenvironment for endogenous regeneration or repair, and depending on the material's design can be used either alone or as a carrier to deliver therapeutic molecules or stem cells. The type of injectable biomaterial is key for a successful hydrogel-based treatment, and in this chapter, we will focus on acellular injectable biomaterial approaches for both MI and PAD

    Rat Adipose Tissue-Derived Stem Cells Transplantation Attenuates Cardiac Dysfunction Post Infarction and Biopolymers Enhance Cell Retention

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    Background: Cardiac cell transplantation is compromised by low cell retention and poor graft viability. Here, the effects of co-injecting adipose tissue-derived stem cells (ASCs) with biopolymers on cell cardiac retention, ventricular morphometry and performance were evaluated in a rat model of myocardial infarction (MI). Methodology/Principal Findings: (99m)Tc-labeled ASCs (1 x 10(6) cells) isolated from isogenic Lewis rats were injected 24 hours post-MI using fibrin a, collagen (ASC/C), or culture medium (ASC/M) as vehicle, and cell body distribution was assessed 24 hours later by gamma-emission counting of harvested organs. ASC/F and ASC/C groups retained significantly more cells in the myocardium than ASC/M (13.8+/-2.0 and 26.8+/-2.4% vs. 4.8+/-0.7%, respectively). Then, morphometric and direct cardiac functional parameters were evaluated 4 weeks post-MI cell injection. Left ventricle (LV) perimeter and percentage of interstitial collagen in the spare myocardium were significantly attenuated in all ASC-treated groups compared to the non-treated (NT) and control groups (culture medium, fibrin, or collagen alone). Direct hemodynamic assessment under pharmacological stress showed that stroke volume (SV) and left ventricle end-diastolic pressure were preserved in ASC-treated groups regardless of the vehicle used to deliver ASCs. Stroke work (SW), a global index of cardiac function, improved in ASC/M while it normalized when biopolymers were co-injected with ASCs. A positive correlation was observed between cardiac ASCs retention and preservation of SV and improvement in SW post-MI under hemodynamic stress. Conclusions: We provided direct evidence that intramyocardial injection of ASCs mitigates the negative cardiac remodeling and preserves ventricular function post-MI in rats and these beneficial effects can be further enhanced by administrating co-injection of ASCs with biopolymers.Fundacao de Amparo a Pesquisa do Estado de Sao Paulo (FAPESP)[01/0009-0]Fundacao de Amparo a Pesquisa do Estado de Sao Paulo (FAPESP)[05/54695-3]Fundacao de Amparo a Pesquisa do Estado de Sao Paulo (FAPESP)[04/06784-4]Ministerio da Ciencia e Tecnologia/Conselho Nacional de Desenvolvimento Cientifico e Tecnologico/Ministerio da Saude/Departamento Ciencia e Tecnologia (MCT/CNPq/MS/DECIT)[552324/20005-1]Ministerio da Ciencia e Tecnologia/Conselho Nacional de Desenvolvimento Cientifico e Tecnologico/Ministerio da Saude/Departamento Ciencia e Tecnologia (MCT/CNPq/MS/DECIT)[10120104096700]CNPq[141276/2004-5

    Report of the Working Group on Commercial Catches (WGCATCH)

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    The Working Group on Commercial Catches (WGCATCH), chaired by Mike Arm- strong (UK) and Hans Gerritsen (Ireland), met in ICES HQ, Copenhagen, Denmark, 10–14 November 2014. The meeting was attended by 34 experts from 21 laboratories or organizations, covering 16 countries. Currently, an important task for WGCATCH is to improve and review sampling sur- vey designs for commercial fisheries, particularly those for estimating quantities and size or age compositions of landings and discards and providing data quality indica- tors. However, the scope of WGCATCH is broader than this, covering many other aspects of collection and analysis of data on fishing activities and catches. This will be end-user driven, and coordinated with the work of other ICES data EGs such as the Working Group on Biological Parameters (WGBIOP), the Planning Group on Data Needs for Assessments and Advice (PGDATA) and the Working Group on Recrea- tional Fisheries Surveys (WGRFS) to ensure synergy and efficiency. The report of the meeting commences with background information on the formation of WGCATCH and its overall role. The remainder of the report provides the out- comes for each of the Terms of Reference (ToRs) and responses to external requests, the proposed future work plan and the ToRs for the 2015 meeting. The group formed two large subgroups to deal with the two major terms of reference which are the development of guidelines for carrying out sampling of catches on shore and the provision of advice on adapting sampling programmes to deal with the landing obligation. In order to evaluate methods and develop guidelines for best practice in carrying out sampling of commercial sampling of commercial fish catches onshore, a question- naire was circulated before the meeting. This questionnaire was structured around guidelines developed by the ICES Workshop on Practical Implementation of Statisti- cally Sound Catch Sampling Programmes (WKPICS) for best practice at each stage of the sampling process, and asked for a description of current practices at each of these stages. Based on these questionnaires, common and specific problems were cata- logued and potential solutions were identified. At the same time, the discussion of the questionnaires provided a form of peer-review of the sampling designs and iden- tified where improvements could be made. WGCATCH provided guidelines for de- signing a sampling survey and summarized earlier guidelines provided by the 2010 Workshop on methods for merging métiers for fishery based sampling (WKMERGE) The other main subject addressed by WGCATCH concerns the provision of advice on adapting sampling protocols to deal with the impact of the introduction of the land- ing obligation, which will alter discarding practices and result in additional catego- ries of catch being landed. A second questionnaire was circulated before the meeting to allow the group to identify the fleets that will be affected and possible issues that are anticipated, as well as to propose solutions to adapt existing monitoring and sampling schemes and to quantify bias resulting from the introduction of this regula- tion. WGCATCH outlined a range of likely scenarios and the expected effects of these on fishery sampling programmes, and developed guidelines for adapting sam- pling schemes. The group also explored a range of analyses that could be conducted in order to quantify bias resulting from the introduction of the landing obligation. Finally a number of pilot studies/case studies were summarized, highlighting the practical issues involve

    Injectable Materials for the Treatment of Myocardial Infarction and Heart Failure: The Promise of Decellularized Matrices

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    Cardiovascular disease continues to be the leading cause of death, suggesting that new therapies are needed to treat the progression of heart failure post-myocardial infarction. As cardiac tissue has a limited ability to regenerate itself, experimental biomaterial therapies have focused on the replacement of necrotic cardiomyocytes and repair of the damaged extracellular matrix. While acellular and cellular cardiac patches are applied surgically to the epicardial surface of the heart, injectable materials offer the prospective advantage of minimally invasive delivery directly into the myocardium to either replace the damaged extracellular matrix or to act as a scaffold for cell delivery. Cardiac-specific decellularized matrices offer the further advantage of being biomimetic of the native biochemical and structural matrix composition, as well as the potential to be autologous therapies. This review will focus on the requirements of an ideal scaffold for catheter-based delivery as well as highlight the promise of decellularized matrices as injectable materials for cardiac repair

    NADPH Oxidase Limits Innate Immune Responses in the Lungs in Mice

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    Background: Chronic granulomatous disease (CGD), an inherited disorder of the NADPH oxidase in which phagocytes are defective in generating superoxide anion and downstream reactive oxidant intermediates (ROIs), is characterized by recurrent bacterial and fungal infections and by excessive inflammation (e.g., inflammatory bowel disease). The mechanisms by which NADPH oxidase regulates inflammation are not well understood. Methodology/Principal Findings: We found that NADPH oxidase restrains inflammation by modulating redox-sensitive innate immune pathways. When challenged with either intratracheal zymosan or LPS, NADPH oxidase-deficient p47phox-/- mice and gp91phox-deficient mice developed exaggerated and progressive lung inflammation, augmented NF-kB activation, and elevated downstream pro-inflammatory cytokines (TNF-α, IL-17, and G-CSF) compared to wildtype mice. Replacement of functional NADPH oxidase in bone marrow-derived cells restored the normal lung inflammatory response. Studies in vivo and in isolated macrophages demonstrated that in the absence of functional NADPH oxidase, zymosan failed to activate Nrf2, a key redox-sensitive anti-inflammatory regulator. The triterpenoid, CDDO-Im, activated Nrf2 independently of NADPH oxidase and reduced zymosan-induced lung inflammation in CGD mice. Consistent with these findings, zymosan-treated peripheral blood mononuclear cells from X-linked CGD patients showed impaired Nrf2 activity and increased NF-kB activation. Conclusions/Significance: These studies support a model in which NADPH oxidase-dependent, redox-mediated signaling is critical for termination of lung inflammation and suggest new potential therapeutic targets for CGD

    Loss of Dnmt3b function upregulates the tumor modifier Ment and accelerates mouse lymphomagenesis

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    DNA methyltransferase 3B (Dnmt3b) belongs to a family of enzymes responsible for methylation of cytosine residues in mammals. DNA methylation contributes to the epigenetic control of gene transcription and is deregulated in virtually all human tumors. To better understand the generation of cancer-specific methylation patterns, we genetically inactivated Dnmt3b in a mouse model of MYC-induced lymphomagenesis. Ablation of Dnmt3b function using a conditional knockout in T cells accelerated lymphomagenesis by increasing cellular proliferation, which suggests that Dnmt3b functions as a tumor suppressor. Global methylation profiling revealed numerous gene promoters as potential targets of Dnmt3b activity, the majority of which were demethylated in Dnmt3b–/– lymphomas, but not in Dnmt3b–/– pretumor thymocytes, implicating Dnmt3b in maintenance of cytosine methylation in cancer. Functional analysis identified the gene Gm128 (which we termed herein methylated in normal thymocytes [Ment]) as a target of Dnmt3b activity. We found that Ment was gradually demethylated and overexpressed during tumor progression in Dnmt3b–/– lymphomas. Similarly, MENT was overexpressed in 67% of human lymphomas, and its transcription inversely correlated with methylation and levels of DNMT3B. Importantly, knockdown of Ment inhibited growth of mouse and human cells, whereas overexpression of Ment provided Dnmt3b+/+ cells with a proliferative advantage. Our findings identify Ment as an enhancer of lymphomagenesis that contributes to the tumor suppressor function of Dnmt3b and suggest it could be a potential target for anticancer therapies

    The hypomethylating agent Decitabine causes a paradoxical increase in 5-hydroxymethylcytosine in human leukemia cells

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    The USFDA approved "epigenetic drug", Decitabine, exerts its effect by hypomethylating DNA, demonstrating the pivotal role aberrant genome-wide DNA methylation patterns play in cancer ontology. Using sensitive technologies in a cellular model of Acute Myeloid Leukemia, we demonstrate that while Decitabine reduces the global levels of 5-methylcytosine (5mC), it results in paradoxical increase of 5-hydroxymethylcytosine (5hmC), 5-formylcytosine (5fC) and 5-carboxylcytosine (5caC) levels. Hitherto, the only biological mechanism known to generate 5hmC, 5fC and 5caC, involving oxidation of 5mC by members of Ten-Eleven-Translocation (TET) dioxygenase family, was not observed to undergo any alteration during DAC treatment. Using a multi-compartmental model of DNA methylation, we show that partial selectivity of TET enzymes for hemi-methylated CpG dinucleotides could lead to such alterations in 5hmC content. Furthermore, we investigated the binding of TET1-catalytic domain (CD)-GFP to DNA by Fluorescent Correlation Spectroscopy in live cells and detected the gradual increase of the DNA bound fraction of TET1-CD-GFP after treatment with Decitabine. Our study provides novel insights on the therapeutic activity of DAC in the backdrop of the newly discovered derivatives of 5mC and suggests that 5hmC has the potential to serve as a biomarker for monitoring the clinical success of patients receiving DAC

    Disclosure of cancer diagnosis and quality of life in cancer patients: should it be the same everywhere?

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    <p>Abstract</p> <p>Background</p> <p>Evidence suggests that truth telling and honest disclosure of cancer diagnosis could lead to improved outcomes in cancer patients. To examine such findings in Iran, this trial aimed to study the various dimensions of quality of life in patients with gastrointestinal cancer and to compare these variables among those who knew their diagnosis and those who did not.</p> <p>Methods</p> <p>A consecutive sample of patients with gastrointestinal cancer being treated in Cancer Institute in Tehran, Iran was prospectively evaluated. A psychologist interviewed patients using the Iranian version of the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire (EORTC QLQ-C30). Patients were categorized into two groups: those who knew their diagnosis and those who did not. Independent sample t-test was used for group comparisons.</p> <p>Results</p> <p>In all 142 patients were interviewed. A significant proportion (52%) of patients did not know their cancer diagnosis and 48% of patients were aware that they had cancer. They were quite similar in most characteristics. The comparison of quality of life between two groups indicated that those knew their diagnosis showed a significant lower degree of physical (P = 0.001), emotional (P = 0.01) and social functioning (P < 0.001), whereas the global quality of life and other functional scales including role functioning and cognitive functioning did not show significant result. There were no statistically significant differences between symptoms scores between two groups, except for fatigue suggesting a higher score in patients who knew their diagnosis (P = 0.01). The financial difficulties were also significantly higher in patients who knew their cancer diagnosis (P = 0.005). Performing analysis of variance while controlling for age, educational status, cancer site, and knowledge of cancer diagnosis, the results showed that the knowledge of cancer diagnosis independently still contributed to the significant differences observed between two groups.</p> <p>Conclusion</p> <p>Contrary to expectation the findings indicated that patients who did not know their cancer diagnosis had a better physical, social and emotional quality of life. It seems that due to cultural differences between countries cancer disclosure guidelines perhaps should be differing.</p

    Arsenic trioxide, a potent inhibitor of NF-κB, abrogates allergen-induced airway hyperresponsiveness and inflammation

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    BACKGROUND: Overactivation of nuclear factor κB (NF-κB) orchestrates airway eosinophilia, but does not dampen airway hyperresponsiveness in asthma. NF-κB repression by arsenic trioxide (As(2)O(3)) contributes to apoptosis of eosinophils (EOS) in airways. Here we provide evidence that As(2)O(3 )abrogates allergen (OVA)-induced airway eosinophilia by modulating the expression of IκBα, an NF-κB inhibitory protein, and decreases the airway hyperresponsiveness. METHODS: Using a murine model of asthma, the airway hyperresponsiveness was conducted by barometric whole-body plethysmography. Airway eosinophilia, OVA-specific IgE in serum, and chemokine eotaxin and RANTES (regulated upon activation, normal T cell expressed and secreted) in bronchoalveolar lavage fluid were measured by lung histology, Diff-Quick staining, and ELISA. Chemokine-induced EOS chemotactic activity was evaluated using EOS chemotaxis assay. Electrophoretic mobility shift assay and Western blot analysis were performed to assess pulmonary NF-κB activation and IκBα expression, respectively. RESULTS: As(2)O(3 )attenuated the allergen-induced serum IgE, chemokine expression of eotaxin and RANTES, and the EOS recruitment in bronchoalveolar lavage fluid, which is associated with an increased IκBα expression as well as a decreased NF-κB activation. Also, As(2)O(3 )suppressed the chemotaxis of EOS dose-dependently in vitro. Additionally, As(2)O(3 )significantly ameliorated the allergen-driven airway hyperresponsiveness, the cardinal feature underlying asthma. CONCLUSION: These findings demonstrate an essential role of NF-κB in airway eosinophilia, and illustrate a potential dissociation between airway inflammation and hyperresponsiveness. As(2)O(3 )likely exerts its broad anti-inflammatory effects by suppression of NF-κB activation through augmentation of IκBα expression in asthma
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