Search results for "DATES"
showing 10 items of 80 documents
Co-regulation between cyclo-oxygenase-2 and inducible nitric oxide synthase expression in the time-course of murine inflammation.
2000
Many in vitro studies have used cell cultures to focus on the relationships between cyclo-oxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS) isoforms. We have investigated the time-course of regulation and the role of COX-2 and iNOS in a model of experimental inflammation in mice, the air pouch injected with zymosan. This study demonstrates that there is an early acute phase (4 h) mediated mainly by eicosanoids, with high levels of prostaglandin E2 (PGE2) produced by cyclo-oxygenase-1. In addition, in the later phase (from 12 h) there is a participation of nitric oxide (NO) and PGE2 accompanied by co-induction of both iNOS and COX-2. These enzymes were detected in migrating leuk…
Induction of rapid and reversible cytokeratin filament network remodeling by inhibition of tyrosine phosphatases
2002
The cytokeratin filament network is intrinsically dynamic, continuously exchanging subunits over its entire surface, while conferring structural stability on epithelial cells. However, it is not known how cytokeratin filaments are remodeled in situations where the network is temporarily and spatially restricted. Using the tyrosine phosphatase inhibitor orthovanadate we observed rapid and reversible restructuring in living cells, which may provide the basis for such dynamics. By examining cells stably expressing fluorescent cytokeratin chimeras, we found that cytokeratin filaments were broken down and then formed into granular aggregates within a few minutes of orthovanadate addition. After …
Light-induced resistance of the keratin network to the filament-disrupting tyrosine phosphatase inhibitor orthovanadate.
2003
Epidermal keratinocytes respond to low-dose light irradiation by inducing signaling cascades that lead to long-term effects on gene transcription thereby protecting cells against damage. In contrast, little is known about immediate light-induced alterations of structural proteins. We have made the intriguing observation that light produces fundamental changes in the properties of the keratin filament system of cultured epidermoid A-431 cells. A short light exposure (1–10 min) causes the keratin cytoskeleton to become immediately resistant to the tyrosine phosphatase inhibitor orthovanadate, which otherwise disrupts the keratin filament network completely in just a few minutes. This protecti…
Tyrosine Phosphorylation Modulates the Vascular Responses of Mesenteric Arteries from Human Colorectal Tumors
2013
The aim of this study was to analyze whether tyrosine phosphorylation in tumoral arteries may modulate their vascular response. To do this, mesenteric arteries supplying blood flow to colorectal tumors or to normal intestine were obtained during surgery and prepared for isometric tension recording in an organ bath. Increasing tyrosine phosphorylation with the phosphatase inhibitor, sodium orthovanadate produced arterial contraction which was lower in tumoral than in control arteries, whereas it reduced the contraction to noradrenaline in tumoral but not in control arteries and reduced the relaxation to bradykinin in control but not in tumoral arteries. Protein expression of VEGF-A and of th…
A mediterranean perspective of the neolithization process. The cave of Nerja in the context of andalusia (Spain)
2013
[EN] This paper offers an overview for the Early Neolithic of the southern coast of Andalusia (Spain). Analyses of materials recovered during the 1979-87 excavations in Nerja cave by professor Francisco Jordá Cerdá, including new radiocarbon dates on domestic taxa, allow us to examine the Mesolithic-Neolithic transition. Paleoenvironmental and paleoeconomic data (stratigraphy and bioarcheological data) combined with archaeological data (ornaments, bone tools, lithics, and ceramics were analysed) to provide a regional perspective on the neolithisation of the western Mediterranean. There is an apparent 500-year gap between occupations by the last coastal foragers and the earliest Neolithic fa…
Growth and development of Ambrosia artemisiifolia L. under different trophic conditions
2014
Ambrosia artemisiifolia L. (common ragweed) is an annual weed regarded as an invasive plant in France. This species can be found in a large range of soil types with regard to texture, pH or nutrient contents. Furthermore, its tolerance to different forms of stress increases its spread potential. This work was undertaken to evaluate the development and growth of common ragweed under different trophic conditions in a common garden. Three cohorts of 15 plants per treatments were sown in spring 2013 and the effects of nitrogen and irrigation were compared on each sowing dates. During the first weeks, vegetative appearance is strongly linked with the sum of temperature. For the first cohort, the…
Transformations socio-spatiales de Besançon : analyse exploratoire multi-dates
2009
This article proposes an analysis of socio-spatial configurations of various districts in the city of Besançon over the intercensal period from 1990 to 1999. This study is based on a multi-date exploratory statistical analysis trying to clarify the sustainable or unsustainable structures in the urban system. Census data for 1990 and 1999 are used to generate twenty or so indicators which characterize the enumeration districts of Besançon (these statistical areas are known as IRIS in French census). According to a factor analysis, we can observe the trajectories of the IRIS between the two chosen dates, which depend on the considered indicators. This analysis highlights the sociospatial orga…
Yodatos bajo condiciones extremas: Transiciones de fase inducidas por la presión, propiedades estructurales, vibracionales y electrónicas
2022
La estructura cristalina de los yodatos metálicos juega un papel importante en la respuesta SHG, así como también lo hacen la estructura de bandas electrónica y la energía de bandgap de la misma. Por ello, en esta tesis doctoral se estudia en profundidad y se presentan y analizan resultados de la estructura cristalina a alta presión, las vibraciones atómicas y la estructura de bandas electrónica de cuatro yodatos metálicos. Estos son el yodato de hierro, Fe(IO3)3, el yodato de cobalto, Co(IO3)2, el yodato de zinc, Zn(IO3)2, y yodato de magnesio Mg(IO3)2. Estos materiales han sido estudiados por medio de difracción de rayos X a alta presión (HPXRD), dispersión Raman a alta presión (HPRS), es…
Polish local democracy in crisis? Non-competitive elections and the supply of candidates for councillors
2022
Competitive elections are the basis of democracy; without them there is no freedom of choice. Elections without competition are associated with the façade nature of elections in undemocratic systems. There are, however, exceptions to the belief that in a democratic system every election must be competitive. We can also observe them in Poland, particularly in small communes with up to 20,000 inhabitants. They take two forms: non-competitive elections of commune leaders and councillors. The latter case is known in the literature under the legal term of filling seats without voting. In 2018, as many as 8% of Polish councillors obtained their mandate without votes. In 2018 compared to 2014, the…
Effects of sulphonylureas on spontaneous motility and induced contractions in rat isolated uterus
1986
Abstract To clarify the action of sulphonylureas on calcium, the effect of tolbutamide and ghbenclamide has been investigated on a Ca-dependent process, the contractile activity of uterine smooth muscle. Both sulphonylureas antagonized the contractions evoked by CaCl2 in a non-competitive manner when the uterus was maintained in depolarizing solution and did not affect the spontaneous contractions of rat uterus. The capacity of tolbutamide and ghbenclamide to relax vanadate-induced contraction of rat uterus in Ca-free medium suggests that sulphonylureas may have an intracellular site of action related to cytosolic free Ca levels, or effect a reduction in Ca action.