53 research outputs found

    Ázsiai orrszarvúak a Magyar Természettudományi Múzeum gyűjteményében = Asian rhinos in the Hungarian Natural History Museum

    Get PDF
    Descriptions of a Sumatran rhinoceros Dicerorhinus sumatrensis and a Javan rhinoceros Rhinoceros sondaicus specimen, housed in the Hungarian Natural History Museum are given. The Sumatran rhinoceros was probably captured in Peninsular Malaysia in 1894 and purchased by the Municipal Botanical and Zoological Gardens, Budapest, Hungary, whereas the Javan rhinoceros was shot by J. Xántus Hungarian explorer in Java in 1869. Both were later donated to the Hungarian Natural History Museum where they are preserved as mounted specimens and some bones. With 6 figure

    Critical role of extracellular vesicles in modulating the cellular effects of cytokines

    Get PDF
    Under physiological and pathological conditions, extracellular vesicles (EVs) are present in the extracellular compartment simultaneously with soluble mediators. We hypothesized that cytokine effects may be modulated by EVs, the recently recognized conveyors of intercellular messages. In order to test this hypothesis, human monocyte cells were incubated with CCRF acute lymphoblastic leukemia cell line-derived EVs with or without the addition of recombinant human TNF, and global gene expression changes were analyzed. EVs alone regulated the expression of numerous genes related to inflammation and signaling. In combination, the effects of EVs and TNF were additive, antagonistic, or independent. The differential effects of EVs and TNF or their simultaneous presence were also validated by Taqman assays and ELISA, and by testing different populations of purified EVs. In the case of the paramount chemokine IL-8, we were able to demonstrate a synergistic upregulation by purified EVs and TNF. Our data suggest that neglecting the modulating role of EVs on the effects of soluble mediators may skew experimental results. On the other hand, considering the combined effects of cytokines and EVs may prove therapeutically useful by targeting both compartments at the same time

    Differential detergent sensitivity of extracellular vesicle subpopulations

    Get PDF
    This work shows for the first time that exosomes are more resistant to detergents than microvesicles and apoptotic bodies.</p

    Development of a large-scale pathogen screening test for the biosafety evaluation of canine mesenchymal stem cells

    Get PDF
    Background The action of mesenchymal stem cells (MSCs) is the subject of intense research in the field of regenerative medicine, including their potential use in companion animals, such as dogs. To ensure the safety of canine MSC batches for their application in regenerative medicine, a quality control test must be conducted in accordance with Good Manufacturing Practices (GMP). Based on guidance provided by the European Medicines Agency, this study aimed to develop and validate a highly sensitive and robust, nucleic acid-based test panel for the detection of various canine pathogens. Analytical sensitivity, specificity, amplification efficiency, and linearity were evaluated to ensure robust assessment. Additionally, viable spike-in controls were used to control for optimal nucleic acid extraction. The conventional PCR-based and real-time PCR-based pathogen assays were evaluated in a real-life setting, by direct testing MSC batches. Results The established nucleic acid-based assays displayed remarkable sensitivity, detecting 100–1 copies/reaction of template DNA. They also exhibited high specificity and efficiency. Moreover, highly effective nucleic acid isolation was confirmed by the sensitive detection of spike-in controls. The detection capacity of our optimized and validated methods was determined by direct pathogen testing of nine MSC batches that displayed unusual phenotypes, such as reduced cell division or other deviating characteristics. Among these MCS batches of uncertain purity, only one tested negative for all pathogens. The direct testing of these samples yielded positive results for important canine pathogens, including tick-borne disease-associated species and viral members of the canine infectious respiratory disease complex (CIRDC). Notably, samples positive for the etiological agents responsible for enteritis (CPV), leptospirosis (Leptospira interrogans), and neosporosis (Neospora caninum) were also identified. Furthermore, we conducted biosafety evaluation of 12 MSC batches intended for therapeutic application. Eleven MSC batches were found to be free of extraneous agents, and only one tested positive for a specific pathogen, namely, canine parvovirus. Conclusion In this study, we established and validated reliable, highly sensitive, and accurate nucleic acid-based testing methods for a broad spectrum of canine pathogens

    Improved Characterization of EV Preparations Based on Protein to Lipid Ratio and Lipid Properties.

    Get PDF
    In recent years the study of extracellular vesicles has gathered much scientific and clinical interest. As the field is expanding, it is becoming clear that better methods for characterization and quantification of extracellular vesicles as well as better standards to compare studies are warranted. The goal of the present work was to find improved parameters to characterize extracellular vesicle preparations. Here we introduce a simple 96 well plate-based total lipid assay for determination of lipid content and protein to lipid ratios of extracellular vesicle preparations from various myeloid and lymphoid cell lines as well as blood plasma. These preparations included apoptotic bodies, microvesicles/microparticles, and exosomes isolated by size-based fractionation. We also investigated lipid bilayer order of extracellular vesicle subpopulations using Di-4-ANEPPDHQ lipid probe, and lipid composition using affinity reagents to clustered cholesterol (monoclonal anti-cholesterol antibody) and ganglioside GM1 (cholera toxin subunit B). We have consistently found different protein to lipid ratios characteristic for the investigated extracellular vesicle subpopulations which were substantially altered in the case of vesicular damage or protein contamination. Spectral ratiometric imaging and flow cytometric analysis also revealed marked differences between the various vesicle populations in their lipid order and their clustered membrane cholesterol and GM1 content. Our study introduces for the first time a simple and readily available lipid assay to complement the widely used protein assays in order to better characterize extracellular vesicle preparations. Besides differentiating extracellular vesicle subpopulations, the novel parameters introduced in this work (protein to lipid ratio, lipid bilayer order, and lipid composition), may prove useful for quality control of extracellular vesicle related basic and clinical studies

    Melanoma-Derived Exosomes Induce PD-1 Overexpression and Tumor Progression via Mesenchymal Stem Cell Oncogenic Reprogramming

    Get PDF
    Recently, it has been described that programmed cell death protein 1 (PD-1) overexpressing melanoma cells are highly aggressive. However, until now it has not been defined which factors lead to the generation of PD-1 overexpressing subpopulations. Here, we present that melanoma-derived exosomes, conveying oncogenic molecular reprogramming, induce the formation of a melanoma-like, PD-1 overexpressing cell population (mMSCPD-1+) from naïve mesenchymal stem cells (MSCs). Exosomes and mMSCPD-1+ cells induce tumor progression and expression of oncogenic factors in vivo. Finally, we revealed a characteristic, tumorigenic signaling network combining the upregulated molecules (e.g., PD-1, MET, RAF1, BCL2, MTOR) and their upstream exosomal regulating proteins and miRNAs. Our study highlights the complexity of exosomal communication during tumor progression and contributes to the detailed understanding of metastatic processes

    European Registry on Helicobacter pylori management (Hp-EuReg): Patterns and trends in first-line empirical eradication prescription and outcomes of 5 years and 21 533 patients

    Get PDF
    Objective The best approach for Helicobacter pylori management remains unclear. An audit process is essential to ensure clinical practice is aligned with best standards of care. Design International multicentre prospective non-interventional registry starting in 2013 aimed to evaluate the decisions and outcomes in H. pylori management by European gastroenterologists. Patients were registered in an e-CRF by AEG-REDCap. Variables included demographics, previous eradication attempts, prescribed treatment, adverse events and outcomes. Data monitoring was performed to ensure data quality. Time-trend and geographical analyses were performed. Results 30 394 patients from 27 European countries were evaluated and 21 533 (78%) first-line empirical H. pylori treatments were included for analysis. Pretreatment resistance rates were 23% to clarithromycin, 32% to metronidazole and 13% to both. Triple therapy with amoxicillin and clarithromycin was most commonly prescribed (39%), achieving 81.5% modified intention-to-treat eradication rate. Over 90% eradication was obtained only with 10-day bismuth quadruple or 14-day concomitant treatments. Longer treatment duration, higher acid inhibition and compliance were associated with higher eradication rates. Time-trend analysis showed a region-dependent shift in prescriptions including abandoning triple therapies, using higher acid-inhibition and longer treatments, which was associated with an overall effectiveness increase (84%-90%). Conclusion Management of H. pylori infection by European gastroenterologists is heterogeneous, suboptimal and discrepant with current recommendations. Only quadruple therapies lasting at least 10 days are able to achieve over 90% eradication rates. European recommendations are being slowly and heterogeneously incorporated into routine clinical practice, which was associated with a corresponding increase in effectiveness
    corecore