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Differentiating Factor (differentiating + factor)
Selected AbstractsHuman lactoferrin activates NF-,B through the Toll-like receptor 4 pathway while it interferes with the lipopolysaccharide-stimulated TLR4 signalingFEBS JOURNAL, Issue 9 2010Ken Ando Lactoferrin (LF) has been implicated in innate immunity. Here we reveal the signal transduction pathway responsible for human LF (hLF)-triggered nuclear factor-,B (NF-,B) activation. Endotoxin-depleted hLF induces NF-,B activation at physiologically relevant concentrations in the human monocytic leukemia cell line, THP-1, and in mouse embryonic fibroblasts (MEFs). In MEFs, in which both tumor necrosis factor receptor-associated factor 2 (TRAF2) and TRAF5 are deficient, hLF causes NF-,B activation at a level comparable to that seen in wild-type MEFs, whereas TRAF6-deficient MEFs show significantly impaired NF-,B activation in response to hLF. TRAF6 is known to be indispensable in leading to NF-,B activation in myeloid differentiating factor 88 (MyD88)-dependent signaling pathways, while the role of TRAF6 in the MyD88-independent signaling pathway has not been clarified extensively. When we examined the hLF-dependent NF-,B activation in MyD88-deficient MEFs, delayed, but remarkable, NF-,B activation occurred as a result of the treatment of cells with hLF, indicating that both MyD88-dependent and MyD88-independent pathways are involved. Indeed, hLF fails to activate NF-,B in MEFs lacking Toll-like receptor 4 (TLR4), a unique TLR group member that triggers both MyD88-depependent and MyD88-independent signalings. Importantly, the carbohydrate chains from hLF are shown to be responsible for TLR4 activation. Furthermore, we show that lipopolysaccharide-induced cytokine and chemokine production is attenuated by intact hLF but not by the carbohydrate chains from hLF. Thus, we present a novel model concerning the biological function of hLF: hLF induces moderate activation of TLR4-mediated innate immunity through its carbohydrate chains; however, hLF suppresses endotoxemia by interfering with lipopolysaccharide-dependent TLR4 activation, probably through its polypeptide moiety. [source] Grassland communities on a Sahelian peneplain in Burkina FasoFEDDES REPERTORIUM, Issue 1-2 2008J. V. Müller Dr. A detailed phytosociological analysis of grassland communities of a Sahelian peneplain in Burkina Faso (West Africa) is presented. The floristic structure of the vegetation was documented with 113 relevés, which were classified manually and in addition ordinated to characterize main floristic gradients. The topographical situation from high-lying areas of the peneplain with erosion of material to low-lying areas with accumulation of material turned out to be the most important differentiating factor in the data set. All grassland communities are dominated by annual grasses and have large distribution ranges. They colonize sandy-silty, loamy to clayey soils and can be water-saturated or repeatedly inundated during the rainy season, while dry, non-inundated habitats are also colonized. Many grasses are valuable fodder plants and are appreciated by livestock , the peneplain is economically highly important as a grazing ground. Whereas exozoochorous annual species are constantly present companions, perennial herbaceous species are almost completely missing. Stands were grouped into one alliance Panico laeti-Echinochloion colonae and only two phytocoenoses: a rankless Schoenefeldia gracilis -community (with two subcommunities: a typical subcommunity with a large ecological amplitude from sandy-silty to loamy soils, and an Aristida funiculata -subcommunity on sandy, dry, non-inundated soils) and Eragrostietum pilosae. The Eragrostietum pilosae grows in the low-lying areas of the peneplain and connects between communities of seasonally inundated lakes and the grasslands on the upper parts of the pene- plain. Following the topography, the two plant communities form a large transition (zonation complex). It is widespread across the study area and contains the diagnostic species of both plant communities. The plant communities are compared with other Sahelian grass-dominated plant communities, and with plant communities from the Sahara and the (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) Grasfluren einer sahelischen Rumpffläche in Burkina Faso In diesem Beitrag wird eine detaillierte pflanzensoziologische Analyse der Grasfluren einer sahelischen Rumpffläche in Burkina Faso (Westafrika) präsentiert. Die floristische Struktur der Vegetation wurde mit 113 pflanzensoziologischen Aufnahmen dokumentiert. Diese wurden zunächst manuell klassifiziert und anschließend einem Ordinationsverfahren unterzogen, um die wichtigsten Gradienten im floristischen Datensatz aufzuzeigen. Die topographische Geländesituation der Rumpffläche, beginnend mit hochgelegenen Bereichen mit Materialaustrag bis in die Niederungen mit Materialeintrag, wurde als wichtigster differenzierender Faktor des floristischen Datensatzes identifiziert. Alle untersuchten Pflanzengesellschaften der Grasfluren haben große Verbreitungsgebiete und werden von annuellen Gräsern dominiert. Sie sind auf sandig-schluffigen, lehmigen bis tonigen Böden zu finden. Sie können in der Regenzeit entweder wassergesättigt oder wiederholt überflutet sein. Die Grasfluren sind auch auf trockenen, nicht überfluteten Standorten nachgewiesen. Viele der Grasarten sind vom Weidevieh geschätzte Futterpflanzen , die Rumpffläche dient als wirtschaftlich bedeutendes Weideland. Exozoochore, einjährige Arten sind hochstet als Begleiter vorhanden. Hingegen fehlen mehrjährige, krautige Arten fast vollständig. Die Bestände konnten einem pflanzensoziologischen Verband Panico laeti-Echinochloion colonae und zwei Pflanzengesellschaften zugeordnet werden. Die ranglose Schoenefeldia gracilis -Gesellschaft kommt in zwei Untereinheiten vor: eine typische Untereinheit mit breiter ökologischer Amplitude von sandig-schluffigen bis lehmigen Böden, und eine Aristida funiculata Untereinheit auf trockenen, sandigen, nicht überfluteten Böden. Das Eragrostietum pilosae kommt in den tiefliegenden Bereichen Sudanian zone. A close floristic relationship of Sahelian grassland communities with Saharan vegetation could be shown. der Rumpffläche vor und vermittelt zwischen den Pflanzengesellschaften temporärer Seen und den Grasfluren der hochgelegenen Bereiche der Rumpffläche. Der Geländesituation folgend bilden beide Pflanzengesellschaften einen breiten Übergangsbereich (Zonationskomplex). Dieser Übergangsbereich ist im Untersuchungsgebiet weit verbreitet und enthält diagnostische Arten beider Pflanzengesellschaften. Die beschriebenen Einheiten werden mit anderen grasdominierten Pflanzengesellschaften des Sahels sowie der Sahara und der Sudanzone verglichen. Eine enge floristische Beziehung der sahelischen Grasfluren mit Vegetationseinheiten der Sahara wird aufgezeigt. [source] Plant communities along environmental gradients of high-arctic mires in Sassendalen, SvalbardJOURNAL OF VEGETATION SCIENCE, Issue 6 2002Archibald W. Vanderpuye Elvebakk & Prestrud (1996) for species; Elvebakk (1994) for syntaxa Abstract. The wet to moist bryophyte-dominated vegetation of Sassendalen, Svalbard, was classified into seven communities. These communities were grouped into (1) Cardamino nymanii-Saxifragion foliolosae marsh; (2) Caricion stantis fen; (3) Luzulion nivalis snowbed , including manured vegetation corresponding to moss tundras. All communities have a basically arctic distribution. Marshes are developed in habitats with a water table above the bryophyte vegetation surface and fens on sites with a water table level high above the permafrost but below the bryophyte surface. Moss tundras normally have no standing water table, but in Sassendalen they have a low water table due to their development on less steep slopes than in their normal habitat near bird cliffs. CCA confirms that the standing water level is the prime differentiating factor between the alliances, while aspect favourability and permafrost depth differentiate between the fen communities and temporary desiccation is important for the Catoscopium nigritum community. Carex subspathacea is a characteristic fen species in the absence of other Carex species dominating elsewhere in the Arctic. Arctic marshes are linked to an extremely cold environment. They have a very low species diversity with a few species dominating; Arctophila fulva, Pseudocalliergon trifarium, Scorpidium scorpioides and Warnstorfia tundrae are character species. Moss tundra as defined here appears to be restricted to Svalbard and, probably, neighbouring Novaya Zemlya. This may be due to the absence of rodents and the high seabird density, which is related to the mild sea currents reaching further to the north here and which implies manuring of surrounding ecosystems. Manuring in a very cold environment produces moss carpets with a thin active layer and accumulation of thick peat layers without a standing water level. In Sassendalen the role of arctic seabirds is replaced by Svalbard reindeer which are nonmigratory and are concentrated to favourable grazing areas where their manuring effect is intense. Their long-term manuring effect probably explains the occurrence of moss tundras in this weakly rolling landscape where seabird colonies are absent. [source] A retrovirus-based system to stably silence GDF-8 expression and enhance myogenic differentiation in human rhabdomyosarcoma cellsTHE JOURNAL OF GENE MEDICINE, Issue 8 2008Zhuo Yang Abstract Background Myostatin, also called GDF-8, a secreted growth and differentiating factor that belongs to the transforming growth factor-, superfamily, is a known negative regulator of myogenesis in vivo. Overexpression of GDF-8 contributes to the lack of differentiation in human rhabdomyosarcoma (RMS) cells. We investigated whether a retrovirus-based RNA interference (RNAi) system against GDF-8 expression in human RMS cells would enhance myogenic differentiation. Methods A retrovirus-based RNAi system was developed that utilized the U6-RNA polymerase III promoter to drive efficient expression and deliver the GDF8-specific short hairpin RNAs (shRNAs) in human RMS cell A204. In this system, the retrovirus vector was integrated into the host cell genome and allowed stable expression of shRNAs. GDF-8 expression was determined by real-time polymerase chain reaction and western blotting analysis. An 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay was performed to determine the cell proliferation. Myogenic differentiation markers were monitored by western blotting analysis. Cell cycle and apoptosis was determined by propidium iodide staining and analysed in a flow cytometer. Results In the siGDF8 A204 cell pools, the levels of both GDF-8 mRNA and protein were dramatically reduced by this RNAi system. In differentiation conditions, inhibition of myostatin synthesis led to enhanced cell cycle withdrawal, consequently stimulated myogenic differentiation and increased the rate of tumor cell apoptosis. Conclusions The results demonstrate that deactivation of myostatin by using retrovirus-based RNAi thus may be useful for therapy in rhabdomyosarcomas. Copyright © 2008 John Wiley & Sons, Ltd. [source] Insights into the acute cerebral metabolic changes associated with childhood diabetesDIABETIC MEDICINE, Issue 5 2005F. J. Cameron Abstract Aims Type 1 diabetes is a prevalent chronic disease in childhood with the commonest single cause of death being cerebral oedema in the context of diabetic ketoacidosis (DKA). The nature of the alterations in cerebral metabolism that may result in vulnerability to neuronal injury remains unknown. The aim of this study was to analyse the magnetic resonance imaging (MRI) and magnetic resonance spectroscopy (MRS) brain data from eight children with diabetes following acute presentation with hyperglycaemia with or without ketoacidosis, to determine the nature and timing of any alterations in cerebral structure and metabolism. Methods This study used MRI and MRS to investigate regional cerebral abnormalities in a small series of diabetic patients with and without DKA. Changes were compared with the clinical and biochemical features of the patients studied. Results Our small series of patients all demonstrated abnormal signal changes in the frontal region on fluid attenuated inversion recovery (FLAIR) MR imaging, suggestive of oedema, and spectroscopic abnormalities of increased taurine, myoinositol and glucose levels. The MR abnormalities varied in severity but did not correlate with any clinical or biochemical parameters. Conclusions These changes indicate that many diabetic children, particularly at presentation, may have alterations in cerebral metabolism with implications for the pathogenesis and treatment of the cerebral complications of DKA. In addition, our findings suggest that increased taurine may be one of the important differentiating factors in the response of the brain of diabetic children to DKA that may reflect an increase in their vulnerability to cerebral oedema compared with diabetic adults. [source] Progress in the Field of Electrospinning for Tissue Engineering ApplicationsADVANCED MATERIALS, Issue 32-33 2009Seema Agarwal Abstract Electrospinning is an extremely promising method for the preparation of tissue engineering (TE) scaffolds. This technique provides nonwovens resembling in their fibrillar structures those of the extracellular matrix (ECM), and offering large surface areas, ease of functionalization for various purposes, and controllable mechanical properties. The recent developments toward large-scale productions combined with the simplicity of the process render this technique very attractive. Progress concerning the use of electrospinning for TE applications has advanced impressively. Different groups have tackled the problem of electrospinning for TE applications from different angles. Nowadays, electrospinning of the majority of biodegradable and biocompatible polymers, either synthetic or natural, for TE applications is straightforward. Different issues, such as cell penetration, incorporation of growth and differentiating factors, toxicity of solvents used, productivity, functional gradient, etc. are main points of current considerations. The progress in the use of electrospinning for TE applications is highlighted in this article with focus on major problems encountered and on various solutions available until now. [source] Topical silver-impregnated dressings and the importance of the dressing technologyINTERNATIONAL WOUND JOURNAL, Issue 5 2009Keith Cutting ABSTRACT A wide variety of silver-impregnated wound dressings has become available in recent years. This has given the practitioner choice but little evidence by which an appropriate dressing may be selected. In many instances, the ancillary function(s) of the dressing will become differentiating factors that influence choice. For example, the dressing capacity to manage exudate, maintain an optimum moist environment, reduce or avoid maceration, maintain an intimate contact with the wound bed, promote autolytic debridement, sequester bacteria and bind matrix metallo proteases (MMPs) are some of those functions that are of clinical significance and may dictate choice. In this article we present the evidence for these functions, thereby enabling practitioners to evaluate comparative dressing attributes, and so make an informed choice of which silver dressing best suits the needs of the wound under differing circumstances. [source] Modulation of cancer cell line differentiation: A neglected proteomic analysis with potential implications in pathophysiology, diagnosis, prognosis, and therapy of cancerPROTEOMICS - CLINICAL APPLICATIONS, Issue 2 2008Roberto Scatena Professor Abstract The recent development of compounds that induce cell differentiation in various types of cancer cells has enabled the molecular mechanisms governing this kind of induced cancer regression to be investigated. Moreover, this approach to investigating the pathophysiology of neoplasia represents a promising experimental model for proteomic analysis of cancer cells. Modulating neoplastic cell differentiation grade may reveal cytodifferentiation-related protein expression changes, and doing so in vitro has the advantage of less biological variation. Hence, this analysis brings attention to molecular targets of the so-called differentiating factors (i.e., retinoids, hybrid polar compounds, tyrosine kinase inhibitors, etc.) as well as proteins that are frequently associated with differentiation/dedifferentiation processes. The in vitro study of these proteins and of their pathogenetic roles in cancer may ultimately result in the discovery of cancer biomarkers with diagnostic, prognostic, and therapeutic applications. [source] | |||||||||||||