Search results for "Digest"
showing 10 items of 3038 documents
The genomic history of the Aegean palatial civilizations
2021
Summary The Cycladic, the Minoan, and the Helladic (Mycenaean) cultures define the Bronze Age (BA) of Greece. Urbanism, complex social structures, craft and agricultural specialization, and the earliest forms of writing characterize this iconic period. We sequenced six Early to Middle BA whole genomes, along with 11 mitochondrial genomes, sampled from the three BA cultures of the Aegean Sea. The Early BA (EBA) genomes are homogeneous and derive most of their ancestry from Neolithic Aegeans, contrary to earlier hypotheses that the Neolithic-EBA cultural transition was due to massive population turnover. EBA Aegeans were shaped by relatively small-scale migration from East of the Aegean, as e…
Lyophilization of lepidopteran midguts: a preserving method for Bacillus thuringiensis toxin binding studies
2004
Binding assays with brush border membrane vesicles (BBMV) from insect midguts are commonly used in the study of the interactions between Bacillus thuringiensis Cry toxins and their receptors. Collaboration between laboratories often require that frozen insect samples are sent in dry ice. Because of customs restrictions and delays, sample thawing is always a risk and often the biological material becomes ruined during shipping. We have tested lyophilization as an alternative method for preserving insect midguts for binding studies with B. thuringiensis Cry toxins. For this purpose, BBMV were prepared from both frozen and lyophilized midguts from three lepidopteran species: Spodoptera exigua,…
In Vivo and In Vitro Binding of Vip3Aa to Spodoptera frugiperda Midgut and Characterization of Binding Sites by 125 I Radiolabeling
2014
ABSTRACT Bacillus thuringiensis vegetative insecticidal proteins (Vip3A) have been recently introduced in important crops as a strategy to delay the emerging resistance to the existing Cry toxins. The mode of action of Vip3A proteins has been studied in Spodoptera frugiperda with the aim of characterizing their binding to the insect midgut. Immunofluorescence histological localization of Vip3Aa in the midgut of intoxicated larvae showed that Vip3Aa bound to the brush border membrane along the entire apical surface. The presence of fluorescence in the cytoplasm of epithelial cells seems to suggest internalization of Vip3Aa or a fragment of it. Successful radiolabeling and optimization of the…
A taphonomic investigation of small vertebrate accumulations produced by the snowy owl (Bubo scandiacus) and its implications for fossil studies
2019
17 pages; International audience; The action of predators, such as diurnal raptors, owls, mammals or humans, influence the nature of smallvertebrate fossil assemblages but currently their taphonomic features are still poorly understood. In this study,we investigate the taphonomic signature of the snowy owl (Bubo scandiacus) based on an analysis of pelletscollected at breeding sites located in Greenland and the Canadian Arctic. This taxon is widely distributedthrough the North Hemisphere and was an important predator in Pleistocene times. Taphonomic parameterssuggest that, contrary to previous assumptions, B. scandiacus produces, on average, moderate digestion of incisors,molars and post-cra…
Induction of CD36 and thrombospondin-1 in macrophages by hypoxia-inducible factor 1 and its relevance in the inflammatory process.
2012
Inflammation is part of a complex biological response of vascular tissue to pathogens or damaged cells. First inflammatory cells attempt to remove the injurious stimuli and this is followed by a healing process mediated principally by phagocytosis of senescent cells. Hypoxia and p38-MAPK are associated with inflammation, and hypoxia inducible factor 1 (HIF-1) has been detected in inflamed tissues. We aimed to analyse the role of p38-MAPK and HIF-1 in the transcriptional regulation of CD36, a class B scavenger receptor, and its ligand thrombospondin (TSP-1) in macrophages and to evaluate the involvement of this pathway in phagocytosis of apoptotic neutrophils. We have also assessed HIF-1α, p…
Lipid-mediated release of GLP-1 by mouse taste buds from circumvallate papillae: putative involvement of GPR120 and impact on taste sensitivity
2012
Glucagon-like peptide-1 (GLP-1) signaling modulates sweet-taste sensitivity in the mouse. Because circumvallate papillae (CVPs) express both GLP-1 and its receptor, a local regulation has been suggested. However, whether dietary lipids are involved in this regulation, as shown in the gut, is unknown. By using a combination of biochemical, immunohistochemical, and behavioral approaches, the present data i) confirm the role of GLP-1 signaling in the attraction for sucrose, ii) demonstrate that minute quantities of long-chain FAs (LCFAs) reinforce the attraction for sucrose in a GLP-1 receptor-dependent manner, iii) suggest an involvement of the LCFA receptor GPR120 expressed in taste buds in …
Proliferative response of CD4+ T cells and hepatitis B virus clearance in chronic hepatitis with or without hepatitis B e-minus hepatitis B virus mut…
1995
To assess the significance of cell-mediated immunity, T cells were derived from the peripheral blood and liver tissue of hepatitis B virus (HBV)-infected patients and controls. The analysis of the 3H-thymidine-uptake in response to a panel of recombinant HBV antigens revealed that peripheral blood mononuclear cells (PBMC) of the 25 viremic patients with inflammatory active, chronic hepatitis B, 16 with wild-type and nine with HBe-minus HBV mutant infection, showed stronger proliferative responses to HBc and HBe antigens than 16 asymptomatic nonviremic HBsAg carriers with normal aminotransferase levels (HBc: SI 19.3 +/- 3.9 vs. 13.0 +/- 3.2 vs. 8.0 +/- 1.2; P.01 and HBe: SI 16.6 +/- 4.0 vs. …
Molecular Basis for the Interaction of the Hepatitis B Virus Core Antigen with the Surface Immunoglobulin Receptor on Naive B Cells
2001
ABSTRACTThe nucleocapsid of the hepatitis B virus (HBV) is composed of 180 to 240 copies of the HBV core (HBc) protein. HBc antigen (HBcAg) capsids are extremely immunogenic and can activate naive B cells by cross-linking their surface receptors. The molecular basis for the interaction between HBcAg and naive B cells is not known. The functionality of this activation was evidenced in that low concentrations of HBcAg, but not the nonparticulate homologue HBV envelope antigen (HBeAg), could prime naive B cells to produce anti-HBc in vitro with splenocytes from HBcAg- and HBeAg-specific T-cell receptor transgenic mice. The frequency of these HBcAg-binding B cells was estimated by both hybridom…
Activation pattern of signal transducers and activators of transcription (STAT) factors in inflammatory bowel diseases.
2005
Cytokine signaling pathways involving transcription factors of the signal transducers and activators of transcription (STAT) family play a key role in the pathogenesis of inflammatory bowel diseases (IBD). STAT proteins are latent cytoplasmic transcription factors that induce transcription upon phosphorylation, dimerization, and nuclear translocation. However, their activation pattern in IBD is poorly understood. The aim of our study was to characterize STAT-expression in IBD.Mononuclear cells were isolated from 36 colonic specimens of Crohn's disease, ulcerative colitis, or from control patients. Cells were stimulated overnight with antibodies against human CD2 and CD28 and mononuclear cel…
Translating Inflammatory Bowel Disease Research into Clinical Medicine
2009
Recent studies have provided important insights into the pathogenesis of inflammatory bowel disease (IBD). The development of new therapeutic agents has been triggered by basic research and studies in mouse models of IBD. It is expected that improved translational research will lead to optimized therapy and new individualized treatment options.