41 research outputs found
Coarsening Dynamics of Domains in Lipid Membranes
We investigate isothermal diffusion and growth of micron-scale liquid domains within membranes of free-floating giant unilamellar vesicles with diameters between 80 and 250 Am. Domains appear after a rapid temperature quench, when the membrane is cooled through a miscibility phase transition such that coexisting liquid phases form. In membranes quenched far from a miscibility critical point, circular domains nucleate and then progress within seconds to late stage coarsening in which domains grow via two mechanisms 1), collision and coalescence of liquid domains, and 2), Ostwald ripening. Both mechanisms are expected to yield the same growth exponent, alpha = 1/3, where domain radius grows as time(alpha). We measure alpha = 0.28 +/- 0.05, in excellent agreement. In membranes close to a miscibility critical point, the two liquid phases in the membrane are bicontinuous. A quench near the critical composition results in rapid changes in morphology of elongated domains. In this case, we measure alpha = 0.50 +/- 0.16, consistent with theory and simulation
Natural occurrence, exposure assessment & risk characterization of Alternaria mycotoxins in apple by‑products in Argentina
Data on the natural occurrence of Alternaria mycotoxins in apple by-products is lacking in Argentina and the risk of exposure to these mycotoxins has not been characterized before. The levels of alternariol (AOH), alternariol monomethyl ether (AME), altenuene (ALT), tenuazonic acid (TeA), tentoxin (TEN), altertoxin-I (ATX-I), altertoxin-II (ATX-II), alternariol 3-sulfate (AOH-3-S), alternariol 3-glucoside (AOH-3-G), alternariol monomethyl ether 3-sulfate (AME-3-S), and alternariol monomethyl ether 3-glucoside (AME-3-G) were determined in clarified and cloudy apple juices, marmalades, and apple-based infant food from the Argentinean market, and the risk of exposure was characterized. Detectable levels of AME, TEN, TeA, AME-3-S and AOH-3-G were found in clarified juices, while the same mycotoxins plus AOH were found in cloudy apple juices in higher concentrations. AME, TEN, TeA and AOH-3G were detected in marmalades, and AOH, AME, TEN and TeA in apple infant food. Probabilistic exposure assessment and risk characterization were carried out for children between 6 months and 5 years old in Argentina. The highest risk of exposure affected children between 6 and 23 months from the consumption of apple infant food and mainly associated with the alternariols. Better control strategies to prevent the incorporation of Alternaria mouldy core into the process line and the establishment of legislation for Alternaria mycotoxins are needed in Argentina
Clinical Significance of SERPINA1 Gene and Its Encoded Alpha1-antitrypsin Protein in NSCLC
High expression of SERPINA1 gene encoding acute phase protein, alpha1-antitrypsin (AAT), is associated with various tumors. We sought to examine the significance of SERPINA1 and AAT protein in non-small-cell lung cancer (NSCLC) patients and NSCLC cell lines. Tumor and adjacent non-tumor lung tissues and serum samples from 351 NSCLC patients were analyzed for SERPINA1 expression and AAT protein levels. We also studied the impact of SERPINA1 expression and AAT protein on H1975 and H661 cell behavior, in vitro. Lower SERPINA1 expression in tumor but higher in adjacent non-tumor lung tissues (n = 351, p = 0.016) as well as higher serum levels of AAT protein (n = 170, p = 0.033) were associated with worse survival rates. Specifically, in NSCLC stage III patients, higher blood AAT levels (>2.66 mg/mL) correlated with a poor survival (p = 0.002). Intriguingly, levels of serum AAT do not correlate with levels of C-reactive protein, neutrophils-to-leukocyte ratio, and do not correlate with SERPINA1 expression or AAT staining in the tumor tissue. Additional experiments in vitro revealed that external AAT and/or overexpressed SERPINA1 gene significantly improve cancer cell migration, colony formation and resistance to apoptosis. SERPINA1 gene and AAT protein play an active role in the pathogenesis of lung cancer and not just reflect inflammatory reaction related to cancer development.This study was supported in part by the German Centre for Lung Research, grant numbers 82DZL00402 and 82DZL002A1.S
Development and application of salting-out assisted liquid/liquid extraction for multi-mycotoxin biomarkers analysis in pig urine with high performance liquid chromatography/tandem mass spectrometry
Metabolomics guided pathway analysis reveals link between cancer metastasis, cholesterol sulfate, and phospholipids
Background -- Cancer cells that enter the metastatic cascade require traits that allow them to survive within the circulation and colonize distant organ sites. As disseminating cancer cells adapt to their changing microenvironments, they also modify their metabolism and metabolite production. Methods -- A mouse xenograft model of spontaneous tumor metastasis was used to determine the metabolic rewiring that occurs between primary cancers and their metastases. An “autonomous” mass spectrometry-based untargeted metabolomic workflow with integrative metabolic pathway analysis revealed a number of differentially regulated metabolites in primary mammary fat pad (MFP) tumors compared to microdissected paired lung metastases. The study was further extended to analyze metabolites in paired normal tissues which determined the potential influence of metabolites from the microenvironment. Results -- Metabolomic analysis revealed that multiple metabolites were increased in metastases, including cholesterol sulfate and phospholipids (phosphatidylglycerols and phosphatidylethanolamine). Metabolite analysis of normal lung tissue in the mouse model also revealed increased levels of these metabolites compared to tissues from normal MFP and primary MFP tumors, indicating potential extracellular uptake by cancer cells in lung metastases. These results indicate a potential functional importance of cholesterol sulfate and phospholipids in propagating metastasis. In addition, metabolites involved in DNA/RNA synthesis and the TCA cycle were decreased in lung metastases compared to primary MFP tumors. Conclusions -- Using an integrated metabolomic workflow, this study identified a link between cholesterol sulfate and phospholipids, metabolic characteristics of the metastatic niche, and the capacity of tumor cells to colonize distant sites
Consensus guidelines for the use and interpretation of angiogenesis assays
The formation of new blood vessels, or angiogenesis, is a complex process that plays important roles in growth and development, tissue and organ regeneration, as well as numerous pathological conditions. Angiogenesis undergoes multiple discrete steps that can be individually evaluated and quantified by a large number of bioassays. These independent assessments hold advantages but also have limitations. This article describes in vivo, ex vivo, and in vitro bioassays that are available for the evaluation of angiogenesis and highlights critical aspects that are relevant for their execution and proper interpretation. As such, this collaborative work is the first edition of consensus guidelines on angiogenesis bioassays to serve for current and future reference
SLAMF7 and IL-6R define distinct cytotoxic versus helper memory CD8+ T cells
The prevailing ‘division of labor’ concept in cellular immunity is that CD8+ T cells primarily utilize cytotoxic functions to kill target cells, while CD4+ T cells exert helper/inducer functions. Multiple subsets of CD4+ memory T cells have been characterized by distinct chemokine receptor expression. Here, we demonstrate that analogous CD8+ memory T-cell subsets exist, characterized by identical chemokine receptor expression signatures and controlled by similar generic programs. Among them, Tc2, Tc17 and Tc22 cells, in contrast to Tc1 and Tc17 + 1 cells, express IL-6R but not SLAMF7, completely lack cytotoxicity and instead display helper functions including CD40L expression. CD8+ helper T cells exhibit a unique TCR repertoire, express genes related to skin resident memory T cells (TRM) and are altered in the inflammatory skin disease psoriasis. Our findings reveal that the conventional view of CD4+ and CD8+ T cell capabilities and functions in human health and disease needs to be revised
Highly Predictive Model for a Protective Immune Response to the A(H1N1)pdm2009 Influenza Strain after Seasonal Vaccination
Understanding the immune response after vaccination against new influenza strains is highly important in case of an imminent influenza pandemic and for optimization of seasonal vaccination strategies in high risk population groups, especially the elderly. Models predicting the best sero-conversion response among the three strains in the seasonal vaccine were recently suggested. However, these models use a large number of variables and/or information post- vaccination. Here in an exploratory pilot study, we analyzed the baseline immune status in young
Fate of free and modified Alternaria mycotoxins during the production of apple concentrates
Mouldy core is a frequent apple fungal disease, mainly caused by toxigenic Alternaria species. Mouldy core is hardly detected in pre-selection procedures when the apples are destined for industrialization, and to date no information is available on the fate of Alternaria toxins during apple concentrate production. Therefore, we evaluated the effect of this process on the natural contamination levels of 10 Alternaria metabolites: alternariol (AOH), alternariol monomethyl ether (AME), altenuene (ALT), tenuazonic acid (TeA), tentoxin (TEN), altertoxin-I (ATX-I), alternariol 3-sulfate (AOH-3-S), alternariol 3-glucoside (AOH-3-G), alternariol monomethyl ether 3-sulfate (AME-3-S), and alternariol monomethyl ether 3-glucoside (AME-3-G). Six stages (grinding, turbos, decanter muds, pre-concentration, concentrate and rejection) of five independent Red Delicious and one of Granny Smith apple concentrate processes were sampled. Four out of the six processes included clarification, while two did not. The Granny Smith raw material was the least contaminated one, both in quality and quantity of Alternaria mycotoxins. Quantifiable levels of AOH, AME, TeA and TEN, were observed in the ground apples of the Red Delicious processes. Regarding the modified mycotoxins, only AME-3-S was present in the raw material; nevertheless, AOH-3-S and AOH-3-G were detected along the process. ALT, ATX-I, and AME-3-G were not detected at any stage. Clear and cloudy processes showed similar variations on mycotoxin quantities until the clarification step, in which all the mycotoxins analysed underwent a significant reduction to non-quantifiable levels. Only TeA remained at detectable levels in one of the clarified final products. The concentration in the final cloudy product increased with respect to the raw material for AOH (301%), AME (221%), TEN (872%) and TeA (1024%). This is the first report of AOH-3-S and AME-3-S in apple-by-products. The clarification stage in apple concentrate production has a relevant role in reducing Alternaria toxins to safe levels in the final products. A major risk might be associated with cloudy apple-by-products.Fil: Pavicich, Maria Agustina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Micología y Botánica. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Micología y Botánica; Argentina. University of Ghent; BélgicaFil: De Boevre, Marthe. University of Ghent; BélgicaFil: Vidal, Arnau. University of Ghent; BélgicaFil: Iturmendi, Facundo. Universidad Nacional de Río Negro; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Mikula, Hannes. Institute of Applied Synthetic Chemistry; AustriaFil: Warth, Benedikt. Universidad de Viena; AustriaFil: Marko, Doris. Universidad de Viena; AustriaFil: De Saeger, Sarah. University of Ghent; BélgicaFil: Patriarca, Andrea Rosana. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Micología y Botánica. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Micología y Botánica; Argentin
FAM83A and FAM83B as Prognostic Biomarkers and Potential New Therapeutic Targets in NSCLC
Although targeted therapy has improved the survival rates in the last decade, non-small-cell lung cancer (NSCLC) is still the most common cause of cancer-related death. The challenge of identifying new targets for further effective therapies still remains. The FAMily with sequence similarity 83 (FAM83) members have recently been described as novel oncogenes in numerous human cancer specimens and shown to be involved in epidermal growth factor receptor (EGFR) signaling. Here, gene expression of FAM83A and B was analyzed in a cohort of 362 NSCLC patients using qPCR. We further investigated relations in expression and their prognostic value. Functional assays in NSCLC cell lines were performed to evaluate FAM83A and B involvement in proliferation, anchorage-independent growth, migration, and the EGFR pathway. We observed a highly increased gene expression level of FAM83A (ø = 68-fold) and FAM83B (ø = 20-fold) which resulted in poor survival prognosis (p < 0.0001 and p = 0.002). Their expression was influenced by EGFR levels, pathway signaling, and mutation status. Both genes affected cell proliferation, and FAM83A depletion resulted in reduced migration and anchorage-independent growth. The results support the hypothesis that FAM83A and B have different functions in different histological subtypes of NSCLC and might be new therapeutic targets