102 research outputs found

    Surfactant behavior of sodium dodecylsulfate in deep eutectic solvent choline chloride/urea

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    Deep eutectic solvents (DES) resemble ionic liquids but are formed from an ionic mixture instead of being a single ionic compound. Here we present some results that demonstrate that surfactant sodium dodecyl sulfate (SDS) remains surface-active and shows self-assembly phenomena in the most commonly studied DES, choline chloride/urea. X-ray reflectivity (XRR) and small angle neutron scattering (SANS) suggest that the behavior is significantly different from that in water. Our SANS data supports our determination of the critical micelle concentration using surface-tension measurements and suggests that the micelles formed in DES do not have the same shape and size as those seen in water. Reflectivity measurements have also demonstrated that the surfactants remain surface-active below this concentration

    Description of amino acid and fatty acid content during initial development of Lophiosilurus alexandri (Siluriformes: Pseudopimelodidae), a carnivorous freshwater catfish

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    Samples of eggs, newly hatched larvae (NHL), and larvae at the end of the lecithotrophic period (eight days after hatching) (LPL) of Lophiosilurus alexandri were collected to determine the amino acid and fatty acid profiles. Crude protein did not change throughout initial development and the concentration of lipids was highest in NHL. The content of the indispensable amino acids (IAA) isoleucine, leucine, and valine decreased in LPL, while in eggs and NHL they remained high and similar in value. The dispensable amino acids (DAA), such as aspartic acid, tyrosine, and glycine, increased in LPL, while alanine decreased. The percentage of neutral lipids increased in LPL. The saturated fatty acid content decreased during ontogeny, while monounsaturated fatty acids decreased only in LPL. The polyunsaturated fatty acid content was highest in LP. Polar fatty acids were found in higher percentages in eggs and NHL, but lower in LPL. Saturated fatty acid content decreased during ontogenetic development, while that of monounsaturated fatty acids decreased only in LPL. Polyunsaturated fatty acid content was highest in LPL. Protein content was maintained during ontogenetic development, while amino acid classes experienced changes. Lophiosilurus alexandri preferentially uses saturated and monosaturated fatty acids as an energy source during its early development.Amostras de ovos, larvas recém-eclodidas (NHL) e larvas no final do período lecitotrófico (oito dias após a incubação)(LPL) de Lophiosilurus alexandri foram coletadas para determinar os perfis de aminoácidos e ácidos graxos. A proteína bruta não alterou durante o desenvolvimento inicial e a concentração de lipídios foi maior na NHL. O conteúdo dos aminoácidos indispensáveis (IAA) isoleucina, leucina e valina diminuíram em LPL, enquanto nos ovos e NHL eles permaneceram com valores elevados e semelhantes entre si. Os aminoácidos dispensáveis (DAA), como ácido aspártico, tirosina e glicina,aumentaram em LPL, enquanto a alanina diminuiu. A porcentagem de lipídios neutros aumentou em LPL. O teor de ácidos graxos saturados diminuiu durante a ontogenia, enquanto os ácidos graxos monoinsaturados diminuíram apenas em LPL. O teor de ácidos graxos poliinsaturados foi maior em LPL. Os ácidos graxos polares foram encontrados em porcentagens mais altas em ovos e NHL, e menores em LPL. O teor de ácidos graxos saturados reduziu durante o desenvolvimento ontogenético,enquanto que os ácidos graxos monoinsaturados diminuíram apenas em LPL. O teor de ácidos graxos poliinsaturados foi maior em LPL. O conteúdo de proteínas foi mantido durante o desenvolvimento ontogenético, enquanto as classes de aminoácidos sofreram mudanças. Lophiosilurus alexandri usa preferencialmente ácidos graxos saturados e monossaturados como fonte de energia durante o desenvolvimento inicial

    Lipid content and fatty acid dynamics of female muscle, oocytes and larvae of Prochilodus argenteus (Spix & Agassiz, 1829)

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    This work aimed to determine fatty acid dynamics and lipid composition of female muscle, oocytes, newly hatched larvae (NHL) and first feeding larvae (FFL) of Prochilodus argenteus. Oocytes and NHL had the highest percentages of total lipids. Neutral lipids (NL) and polar lipids (PL) remained constant from oocytes through the larval stages (P < 0.05). Among NL, C18:2n 6 had its highest percentage in muscle (P < 0.05) and C18:3n 3 in muscle and oocytes. The highest percentages of arachidonic acid (AA) were in muscle and FFL. The highest percentages of n-9 and n-6 series were in muscle. The highest values of n-3HUFA were in the larval stages while the highest of n-6HUFA were in muscle and FFL. Percentage of ∑SFA in LN was highest in oocytes, NHL and FFL (P < 0.05) while ∑MUFA was highest in muscle, oocytes and NHL. The highest percentages of ∑PUFA were in muscle and FFL. For PL, however, C18:2n 6 and AA were highest in muscle (P < 0.05) while eicosapentaenoic acid was highest in muscle and oocytes. Percentage of ∑SFA in LP was highest in NHL and lowest in FFL and muscle. The highest percentage of ∑MUFA was in oocytes, NHL and FFL (P < 0.05). The highest percentages for series n-9 were in oocytes and FFL (P < 0.05), while the highest percentages for series n-6 were in muscle and oocytes. The lowest percentage for n-6HUFA was in NHL. The n-3 fatty acids were incorporated into the yolk from body reserves, which were stored prior to vitellogenesis and mobilized to the oocytes. The increase in docosahexaenoic acid reflects the ability of the species to lengthen and desaturate C18:3n 3 yielding n-3HUFA, thus demonstrating the importance of this fatty acid during early development

    MiR-200 family controls late steps of postnatal forebrain neurogenesis via Zeb2 inhibition

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    During neurogenesis, generation, migration and integration of the correct numbers of each neuron sub-Type depends on complex molecular interactions in space and time. MicroRNAs represent a key control level allowing the flexibility and stability needed f

    How consistent are the transcriptome changes associated with cold acclimation in two species of the Drosophila virilis group?

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    This work was financially support by a Marie Curie Initial Training Network grant, “Understanding the evolutionary origin of biological diversity” (ITN-2008–213780 SPECIATION), grants from the Academy of Finland to A.H. (project 132619) and M.K. (projects 268214 and 272927), a grant from NERC, UK to M.G.R. (grant NE/J020818/1), and NERC, UK PhD studentship to D.J.P. (NE/I528634/1).For many organisms the ability to cold acclimate with the onset of seasonal cold has major implications for their fitness. In insects, where this ability is widespread, the physiological changes associated with increased cold tolerance have been well studied. Despite this, little work has been done to trace changes in gene expression during cold acclimation that lead to an increase in cold tolerance. We used an RNA-Seq approach to investigate this in two species of the Drosophila virilis group. We found that the majority of genes that are differentially expressed during cold acclimation differ between the two species. Despite this, the biological processes associated with the differentially expressed genes were broadly similar in the two species. These included: metabolism, cell membrane composition, and circadian rhythms, which are largely consistent with previous work on cold acclimation/cold tolerance. In addition, we also found evidence of the involvement of the rhodopsin pathway in cold acclimation, a pathway that has been recently linked to thermotaxis. Interestingly, we found no evidence of differential expression of stress genes implying that long-term cold acclimation and short-term stress response may have a different physiological basis.PostprintPeer reviewe

    Konsensusprotokoll zur Standardisierung von Entnahme und Biobanking des Liquor cerebrospinalis

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    Die Erforschung von Biomarkern in Körperflüssigkeiten bei neurodegenerativen und neuroinflammatorischen Erkrankungen blickt auf eine langjährige Geschichte zurück. Dennoch werden nur wenige Liquor cerebrospinalis (Liquor)-Biomarker in der klinischen Praxis verwendet. Einer der problematischen Faktoren in der Liquorbiomarker-Forschung ist die eingeschränkte Aussagekraft von Studien aufgrund einer nicht ausreichend großer Anzahl von Proben, die in Studien von einzelnen Zentren akquiriert werden können. Deshalb ist die Kooperation zwischen mehreren Zentren erforderlich, um große Biobanken von definierten Proben zu etablieren. Standardisierte Protokolle für Biobanking sind unumgänglich, um die durch die größere Anzahl von Liquorproben gewonnene statistische Aussagekraft sicherzustellen und nicht durch mangelhafte Präanalytik einzuschränken. Hier wird ein Konsensusbericht über Leitlinien zu Liquorentnahme und Biobanking durch das BioMS-eu Netzwerk für Liquorbiomarker-Forschung in Multipler Sklerose präsentiert. Schwerpunkte des Berichts sind Liquorentnahme, präanalytische Faktoren und klinische sowie sonstige Informationen. Biobanking-Protokolle sind für Liquor-Biobanken im Rahmen der Erforschung jeder neurologischen Krankheit anwendba

    Consensus Guidelines for CSF and Blood Biobanking for CNS Biomarker Studies

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    There is a long history of research into body fluid biomarkers in neurodegenerative and neuroinflammatory diseases. However, only a few biomarkers in cerebrospinal fluid (CSF) are being used in clinical practice. Anti-aquaporin-4 antibodies in serum are currently useful for the diagnosis of neuromyelitis optica (NMO), but we could expect novel CSF biomarkers that help define prognosis and response to treatment for this disease. One of the most critical factors in biomarker research is the inadequate powering of studies performed by single centers. Collaboration between investigators is needed to establish large biobanks of well-defined samples. A key issue in collaboration is to establish standardized protocols for biobanking to ensure that the statistical power gained by increasing the numbers of CSF samples is not compromised by pre-analytical factors. Here, consensus guidelines for CSF collection and biobanking are presented, based on the guidelines that have been published by the BioMS-eu network for CSF biomarker research. We focussed on CSF collection procedures, pre-analytical factors and high quality clinical and paraclinical information. Importantly, the biobanking protocols are applicable for CSF biobanks for research targeting any neurological disease

    Synergistic Interactions between HDAC and Sirtuin Inhibitors in Human Leukemia Cells

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    Aberrant histone deacetylase (HDAC) activity is frequent in human leukemias. However, while classical, NAD+-independent HDACs are an established therapeutic target, the relevance of NAD+-dependent HDACs (sirtuins) in leukemia treatment remains unclear. Here, we assessed the antileukemic activity of sirtuin inhibitors and of the NAD+-lowering drug FK866, alone and in combination with traditional HDAC inhibitors. Primary leukemia cells, leukemia cell lines, healthy leukocytes and hematopoietic progenitors were treated with sirtuin inhibitors (sirtinol, cambinol, EX527) and with FK866, with or without addition of the HDAC inhibitors valproic acid, sodium butyrate, and vorinostat. Cell death was quantified by propidium iodide cell staining and subsequent flow-cytometry. Apoptosis induction was monitored by cell staining with FITC-Annexin-V/propidium iodide or with TMRE followed by flow-cytometric analysis, and by measuring caspase3/7 activity. Intracellular Bax was detected by flow-cytometry and western blotting. Cellular NAD+ levels were measured by enzymatic cycling assays. Bax was overexpressed by retroviral transduction. Bax and SIRT1 were silenced by RNA-interference. Sirtuin inhibitors and FK866 synergistically enhanced HDAC inhibitor activity in leukemia cells, but not in healthy leukocytes and hematopoietic progenitors. In leukemia cells, HDAC inhibitors were found to induce upregulation of Bax, a pro-apoptotic Bcl2 family-member whose translocation to mitochondria is normally prevented by SIRT1. As a result, leukemia cells become sensitized to sirtuin inhibitor-induced apoptosis. In conclusion, NAD+-independent HDACs and sirtuins cooperate in leukemia cells to avoid apoptosis. Combining sirtuin with HDAC inhibitors results in synergistic antileukemic activity that could be therapeutically exploited
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