147 research outputs found

    Pathways towards a sustainable future envisioned by early-career conservation researchers

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    Scientists have warned decision-makers about the severe consequences of the global environmental crisis since the 1970s. Yet ecological degradation continues and little has been done to address climate change. We investigated early-career conservation researchers' (ECR) perspectives on, and prioritization of, actions furthering sustainability. We conducted a survey (n = 67) and an interactive workshop (n = 35) for ECR attendees of the 5th European Congress of Conservation Biology (2018). Building on these data and discussions, we identified ongoing and forthcoming advances in conservation science. These include increased transdisciplinarity, science communication, advocacy in conservation, and adoption of a transformation-oriented social-ecological systems approach to research. The respondents and participants had diverse perspectives on how to achieve sustainability. Reformist actions were emphasized as paving the way for more radical changes in the economic system and societal values linked to the environment and inequality. Our findings suggest that achieving sustainability requires a strategy that (1) incorporates the multiplicity of people's views, (2) places a greater value on nature, and (3) encourages systemic transformation across political, social, educational, and economic realms on multiple levels. We introduce a framework for ECRs to inspire their research and practice within conservation science to achieve real change in protecting biological diversity

    Fecal pancreatic elastase-1 levels in older individuals without known gastrointestinal diseases or diabetes mellitus

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    Background - Structural changes occur in the pancreas as a part of the natural aging process. With aging, also the incidence of maldigestive symptoms and malnutrition increases, raising the possibility that these might be caused at least in part by inadequate pancreatic enzyme secretion due to degenerative processes and damage of the gland. Fecal elastase-1 is a good marker of pancreatic exocrine secretion. The aim of this study was to investigate the fecal elastase-1 levels among over 60 years old Finnish and Polish healthy individuals without any special diet, known gastrointestinal disease, surgery or diabetes mellitus. Methods - A total of 159 patients participated in this cross-sectional study. 106 older individuals (aged 60-92 years) were recruited from outpatient clinics and elderly homes. They were divided to three age groups: 60-69 years old (n = 31); 70-79 years old (n = 38) and over 80 years old (n = 37). 53 young subjects (20-28 years old) were investigated as controls. Inclusion criteria were age over 60 years, normal status and competence. Exclusion criteria were any special diet, diabetes mellitus, any known gastrointestinal disease or prior gastrointestinal surgery. Fecal elastase-1 concentration was measured from stool samples with an ELISA that uses two monoclonal antibodies against different epitopes of human elastase-1. Results - Fecal elastase-1 concentrations correlated negatively with age (Pearson r = -0,3531, P < 0.001) and were significantly lower among subjects over 70 years old compared to controls (controls vs. 70-79 years old and controls vs. over 80 years old, both P < 0.001). Among the over 60 years old subjects, the fecal elastase-1 concentrations were below the cut off level of 200 μg/g in 23 of 106 (21.7%) individuals [mean 112 (86-138) μg/g] indicating pancreatic exocrine insufficiency. Of those, 9 subjects had fecal elastase-1 level below 100 μg/g as a marker of severe pancreatic insufficiency. Conclusion - In our study one fifth of healthy older individuals without any gastrointestinal disorder, surgery or diabetes mellitus suffer from pancreatic exocrine insufficiency and might benefit from enzyme supplementation therapy.peerReviewe

    Targeting SDF-1/CXCR4 to inhibit tumour vasculature for treatment of glioblastomas

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    Local recurrence of glioblastomas is a major cause of patient mortality after definitive treatment. This review discusses the roles of the chemokine stromal cell-derived factor-1 and its receptor CXC chemokine receptor 4 (CXCR4) in affecting the sensitivity of glioblastomas to irradiation. Blocking these molecules prevents or delays tumour recurrence after irradiation by inhibiting the recruitment of CD11b+ monocytes/macrophages that participate in revascularising the tumour. We review the literature pertaining to the mechanism by which revascularisation occurs following tumour irradiation using experimental models. Areas of interest and debate in the literature include the process by which endothelial cells die after irradiation and the identity/origin of the cells that reconstitute the tumour blood vessels after injury. Understanding the processes that mediate tumour revascularisation will guide the improvement of clinical strategies for preventing recurrence of glioblastoma after irradiation

    Stromal Cell-Derived Factor-1/CXCL12 Contributes to MMTV-Wnt1 Tumor Growth Involving Gr1+CD11b+ Cells

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    BACKGROUND: Histological examinations of MMTV-Wnt1 tumors reveal drastic differences in the tumor vasculature when compared to MMTV-Her2 tumors. However, these differences have not been formally described, nor have any angiogenic factors been implicated to be involved in the Wnt1 tumors. METHODOLOGY/PRINCIPAL FINDINGS: Here, we show that MMTV-Wnt1 tumors were more vascularized than MMTV-Her2 tumors, and this correlated with significantly higher expression of a CXC chemokine, stromal cell-derived factor-1 (SDF1/CXCL12) but not with VEGFA. Isolation of various cell types from Wnt1 tumors revealed that SDF1 was produced by both tumor myoepithelial cells and stromal cells, whereas Her2 tumors lacked myoepithelial cells and contained significantly less stroma. The growth of Wnt1 tumors, but not Her2 tumors, was inhibited by a neutralizing antibody to SDF1, but not by neutralization of VEGFA. Anti-SDF1 treatment decreased the proportion of infiltrating Gr1(+) myeloid cells in the Wnt1 tumors, which correlated with a decrease in the percentage of endothelial cells. The involvement of Gr1(+) cells was evident from the retardation of Wnt1 tumor growth following in vivo depletion of these cells with an anti-Gr1-specific antibody. This degree of inhibition on Wnt1 tumor growth was comparable, but not additive, to the effect observed with anti-SDF1, indicative of overlapping mechanisms of inhibition. In contrast, Her2 tumors were not affected by the depletion of Gr1(+) cells. CONCLUSIONS/SIGNIFICANCE: We demonstrated that SDF1 is important for Wnt1, but not for HER2, in inducing murine mammary tumor and the role of SDF1 in tumorigenesis involves Gr1(+) myeloid cells to facilitate growth and/or angiogenesis

    Myeloid Cells Contribute to Tumor Lymphangiogenesis

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    The formation of new blood vessels (angiogenesis) and lymphatic vessels (lymphangiogenesis) promotes tumor outgrowth and metastasis. Previously, it has been demonstrated that bone marrow-derived cells (BMDC) can contribute to tumor angiogenesis. However, the role of BMDC in lymphangiogenesis has largely remained elusive. Here, we demonstrate by bone marrow transplantation/reconstitution and genetic lineage-tracing experiments that BMDC integrate into tumor-associated lymphatic vessels in the Rip1Tag2 mouse model of insulinoma and in the TRAMP-C1 prostate cancer transplantation model, and that the integrated BMDC originate from the myelomonocytic lineage. Conversely, pharmacological depletion of tumor-associated macrophages reduces lymphangiogenesis. No cell fusion events are detected by genetic tracing experiments. Rather, the phenotypical conversion of myeloid cells into lymphatic endothelial cells and their integration into lymphatic structures is recapitulated in two in vitro tube formation assays and is dependent on fibroblast growth factor-mediated signaling. Together, the results reveal that myeloid cells can contribute to tumor-associated lymphatic vessels, thus extending the findings on the previously reported role of hematopoietic cells in lymphatic vessel formation

    Hematopoietic Stem Cells Contribute to Lymphatic Endothelium

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    Although the lymphatic system arises as an extension of venous vessels in the embryo, little is known about the role of circulating progenitors in the maintenance or development of lymphatic endothelium. Here, we investigated whether hematopoietic stem cells (HSCs) have the potential to give rise to lymphatic endothelial cells (LEC). mice resulted in the incorporation of donor-derived LEC into the lymphatic vessels of spontaneously arising intestinal tumors.Our results indicate that HSCs can contribute to normal and tumor associated lymphatic endothelium. These findings suggest that the modification of HSCs may be a novel approach for targeting tumor metastasis and attenuating diseases of the lymphatic system

    TRPA1 Is a Polyunsaturated Fatty Acid Sensor in Mammals

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    Fatty acids can act as important signaling molecules regulating diverse physiological processes. Our understanding, however, of fatty acid signaling mechanisms and receptor targets remains incomplete. Here we show that Transient Receptor Potential Ankyrin 1 (TRPA1), a cation channel expressed in sensory neurons and gut tissues, functions as a sensor of polyunsaturated fatty acids (PUFAs) in vitro and in vivo. PUFAs, containing at least 18 carbon atoms and three unsaturated bonds, activate TRPA1 to excite primary sensory neurons and enteroendocrine cells. Moreover, behavioral aversion to PUFAs is absent in TRPA1-null mice. Further, sustained or repeated agonism with PUFAs leads to TRPA1 desensitization. PUFAs activate TRPA1 non-covalently and independently of known ligand binding domains located in the N-terminus and 5th transmembrane region. PUFA sensitivity is restricted to mammalian (rodent and human) TRPA1 channels, as the drosophila and zebrafish TRPA1 orthologs do not respond to DHA. We propose that PUFA-sensing by mammalian TRPA1 may regulate pain and gastrointestinal functions

    Circulating Endothelial Progenitor Cells Are Up-Regulated in a Mouse Model of Endometriosis

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    Endometriosis is a debilitating disease characterized by the growth of ectopic endometrial tissue. It is widely accepted that angiogenesis plays an integral part in the establishment and growth of endometriotic lesions. Recent data from a variety of angiogenesis-dependent diseases suggest a critical role of bone marrow–derived endothelial progenitor cells (EPCs) in neovascularization. In this study we examined the blood levels of EPCs and mature circulating endothelial cells in a mouse model of surgically induced endometriosis. Fluorescence-activated cell sorting analysis revealed elevated levels of EPCs in the blood of mice with endometriosis compared with control subject that underwent a sham operation. EPC concentrations positively correlated with the amount of endometriotic tissue and peaked 1 to 4 days after induction of disease. In a green fluorescent protein bone marrow transplant experiment we found green fluorescent protein–positive endothelial cells incorporated into endometriotic lesions but not eutopic endometrium, as revealed by flow cytometry and immunohistochemistry. Finally, treatment of endometriosis-bearing mice with the angiogenesis inhibitor Lodamin, an oral nontoxic formulation of TNP-470, significantly decreased EPC levels while suppressing lesion growth. Taken together, our data indicate an important role for bone marrow–derived endothelial cells in the pathogenesis of endometriosis and support the potential clinical use of anti-angiogenic therapy as a novel treatment modality for this disease
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