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421.
Vítor Borges Andrea Santos Cristina Belo Correia Margarida Saraiva Armelle Ménard Luís Vieira Daniel A. Sampaio Miguel Pinheiro Jo?o Paulo Gomes Mónica Oleastro 《Applied and environmental microbiology》2015,81(23):8155-8163
Meat and meat products are important sources of human intestinal infections. We report the isolation of Helicobacter pullorum strains from chicken meat. Bacteria were isolated from 4 of the 17 analyzed fresh chicken meat samples, using a membrane filter method. MIC determination revealed that the four strains showed acquired resistance to ciprofloxacin; one was also resistant to erythromycin, and another one was resistant to tetracycline. Whole-genome sequencing of the four strains and comparative genomics revealed important genetic traits within the H. pullorum species, such as 18 highly polymorphic genes (including a putative new cytotoxin gene), plasmids, prophages, and a complete type VI secretion system (T6SS). The T6SS was found in three out of the four isolates, suggesting that it may play a role in H. pullorum pathogenicity and diversity. This study suggests that the emerging pathogen H. pullorum can be transmitted to humans by chicken meat consumption/contact and constitutes an important contribution toward a better knowledge of the genetic diversity within the H. pullorum species. In addition, some genetic traits found in the four strains provide relevant clues to how this species may promote adaptation and virulence. 相似文献
422.
423.
Augusto Vitale Armelle Queyras 《Ethology : formerly Zeitschrift fur Tierpsychologie》1997,103(5):395-403
The main aim of this study was to verify if the response to novel foods in common marmoset (Callithrix jacchus) is influenced by different social settings. This question was tested in three tests involving four social groups. The data regarding the response to novel foods were collected from a total of eight food-naive young. In particular, we explored if direct contacts between food-naive and experienced individuals would have a different effect on the response to novel food by the first, in comparison with a situation in which only visual contacts were allowed. These two different social settings were then compared to a situation in which the response to novel food was not mediated by the experience of group-mates. The results showed a significantly higher number of intervals in which naive young, in social settings, were observed feeding compared with a control test. However, this result was confirmed only in the case of novel foods, not in the case of familiar foods. Furthermore, in the tests in which direct social contacts were allowed, naive young obtained food from group-mates significantly more often in the case of novel than familiar foods. This study suggests that although naive young, when left in pairs, responded quickly to novel foods without the need to observe or interact with experienced group-mates, a process of social facilitation was evident. Such a process was not observed in the case of familiar foods, confirming the hypothesis that social facilitation operates in order to acquire novel foods in the diet of the group in the long term. 相似文献
424.
Nathalie Bufi Michael Saitakis Stéphanie Dogniaux Oscar Buschinger Armelle Bohineust Alain Richert Mathieu Maurin Claire Hivroz Atef Asnacios 《Biophysical journal》2015,108(9):2181-2190
T lymphocytes are key modulators of the immune response. Their activation requires cell-cell interaction with different myeloid cell populations of the immune system called antigen-presenting cells (APCs). Although T lymphocytes have recently been shown to respond to mechanical cues, in particular to the stiffness of their environment, little is known about the rigidity of APCs. In this study, single-cell microplate assays were performed to measure the viscoelastic moduli of different human myeloid primary APCs, i.e., monocytes (Ms, storage modulus of 520 +90/−80 Pa), dendritic cells (DCs, 440 +110/−90 Pa), and macrophages (MPHs, 900 +110/−100 Pa). Inflammatory conditions modulated these properties, with storage moduli ranging from 190 Pa to 1450 Pa. The effect of inflammation on the mechanical properties was independent of the induction of expression of commonly used APC maturation markers, making myeloid APC rigidity an additional feature of inflammation. In addition, the rigidity of human T lymphocytes was lower than that of all myeloid cells tested and among the lowest reported (Young’s modulus of 85 ± 5 Pa). Finally, the viscoelastic properties of myeloid cells were dependent on both their filamentous actin content and myosin IIA activity, although the relative contribution of these parameters varied within cell types. These results indicate that T lymphocytes face different cell rigidities when interacting with myeloid APCs in vivo and that this mechanical landscape changes under inflammation. 相似文献
425.
Cell-extracellular matrix interactions stimulate the AP-1 transcription factor in an integrin-linked kinase- and glycogen synthase kinase 3-dependent manner. 总被引:8,自引:0,他引:8 下载免费PDF全文
Armelle A. Troussard Clara Tan T. Nathan Yoganathan Shoukat Dedhar 《Molecular and cellular biology》1999,19(11):7420-7427
426.
Isobel M. Ralston Jan Wauters Karel Heremans H. Brian Dunford 《Biophysical chemistry》1982,15(1):15-18
The activation volumes for the reactions of horseradish peroxidase compound II with L-tyrosine. 3-iodo-L-tyrosine. p-aminobenzoic acid and ferrocyanide were determined by using a high-pressure stopped-flow technique at 25°C and pH 7. For the tyrosines, the solvent electrostriction accompanying substrate ionization and H+ transfer from the substituted phenol to a basic group of the enzyme can account for the observed negative activation volumes. For p-aminobenzoic acid a simple electron transfer without H+ transfer appears to occur. The positive activation volume for ferrocyanide may be explained in terms of electron transfer associated with a large change in electrostriction of the inorganic redox couple. 相似文献
427.
Armelle Baeza-Squiban Emmanuelle Boisvieux-Ulrich Catherine Guilianelli Odile Houcine Gérard Geraud Christiane Guennou Francelyne Marano 《In vitro cellular & developmental biology. Animal》1994,30(1):56-67
Summary The differentiation of tracheal epithelial cells in primary culture was investigated according to the nature of the extracellular
matrix used. Cultures obtained by the explant technique were realized on a type I collagen substratum either as a thin, dried
coating or as a thick, hydrated gel supplemented with culture medium and serum. These two types of substratum induced distinct
cell morphology and cytokeratin expression in the explant derived cells. Where cells are less proliferating (from Day 7 to
10 of culture), differentiation was evaluated by morphologic ultrastructural observations, immunocytochemical detection of
cytokeratins, and determination of cytokeratin pattern by biochemical analysis.
The epithelium obtained on gel was multilayered, with small, round basal cells under large, flattened upper cells. The determination
of the keratin pattern expressed by cells grown on gel revealed an expression of keratin 13, already considered as a specific
marker of squamous metaplasia, that diminished with retinoic acid treatment. Present results demonstrated by confocal microscopy
that K13-positive cells were large upper cells with a dense keratin network, whereas lower cells were positively stained with
a specific monoclonal antibody to basal cells (KB37). Moreover, keratin neosynthesis analysis pointed out a higher expression
of K6, a marker of hyperproliferation, on gel than on coating. All these data suggest a differentiation of rabbit tracheal
epithelial cells grown on gel toward squamous metaplasia. By contrast, the epithelium observed on coating is nearly a monolayer
of very large and spread out cells. No K13-positive cells were observed, but an increase in the synthesis of simple epithelium
marker (K18) was detected. These two substrata, similar in composition and different in structure, induce separate differentiation
and appear as good tools to explore the mechanisms of differentiation of epithelial tracheal cells. 相似文献
428.
Aline Rigal Rime Michael-Jubeli Alex Nkengne Arlette Baillet-Guffroy Armelle Bigouret Ali Tfayli 《Journal of biophotonics》2021,14(9):e202100107
Skin aging is a multifactorial phenomenon that involves alterations at the molecular, cellular and tissue levels. Our aim was to carry out a multiparametric biophysical and Raman characterization of skin barrier between individuals of different age groups (<24 and >70 years old). Our results showed a significant decrease of lipids to proteins ratio overall the thickness of the stratum corneum and higher lateral packing in the outer part of the SC for elderly. This can explain the decrease in trans epidermal water loss measured values rather than only SC thickening. Both age groups showed similar water content at SC surface while elderly presented higher water content in deep SC and viable epidermis. Mechanical measurements showed a decrease in the elasticity and an increase in the fatigability with age and were correlated with partially bound water. Highest correlation and anti-correlation values were observed for the deepest part of the SC and the viable epidermis. 相似文献
429.
Bessou Cécile Tailleur Aurélie Godard Caroline Gac Armelle de la Cour Julie Lebas Boissy Joachim Mischler Pierre Caldeira-Pires Armando Benoist Anthony 《The International Journal of Life Cycle Assessment》2020,25(7):1217-1230
The International Journal of Life Cycle Assessment - Soil organic carbon (SOC) plays a key role in soil functioning and in greenhouse gas exchange with the atmosphere. Land use and land use changes... 相似文献
430.