Search results for "POLYSACCHARIDE"
showing 10 items of 635 documents
Modulation of IL-1?, IL-6, IL-8, TNF-?, and TGF-? secretions by alveolar macrophages under NO2 exposure
2004
Activated alveolar macrophages (AMs) secrete interleukine (IL)1β, IL-6, IL-8, tumor necrosis factor-α (TNF-α), and transforming growth factor-β (TGF-β), whose inflammatory and fibroblast-activating characteristics may play a role in the maintenance of pulmonary inflammatory processes and subsequent fibrosis. Human AMs were transferred to a gas cylinder and exposed to NO2 in concentrations ranging from 0.1 to 0.5 ppm in synthetic air for 30 min at 37°C. AMs were fixed on a polycarbonate membrane and placed on culture medium. A culture was established, with the exposed AM (nonstimulated or stimulated with 1 μg/ml lipopolysaccharide [LPS]), and the remaining cells were used to determine the cy…
Modulation of endotoxin-induced neutrophil transendothelial migration by alveolar epithelium in a defined bilayer model.
2006
Within the alveolus, epithelial cells, due to their close association with endothelial cells, can potentially influence endothelial cell responsiveness during inflammation and their interaction with leukocytes. To investigate this, three lung epithelial cell lines (A549, Calu-3, or NCI-H441) were grown with endothelium on opposing surfaces of Transwell filters and the formation and stability of bilayers was rigorously evaluated. All epithelial lines disrupted endothelial monolayer formation on filters with 3- or 5-microm pores by breaching the filter, and this occurred regardless of seeding density, matrix composition, or duration of culture. Endothelial disruption was not detectable by ele…
Theophylline suppresses the release of tumour necrosis factor-alpha by blood monocytes and alveolar macrophages.
1994
The purpose of this study was to evaluate the effect of theophylline on tumour necrosis factor-alpha (TNF-alpha) release by human blood monocytes (BMo), and rat BMo and alveolar macrophages (AM). BMo and AM were incubated in the absence or presence of theophylline, and the cell-free supernatants were harvested and tested for TNF-alpha activity by bioassay. Theophylline dose-dependently reduced TNF-alpha release by human BMo: significant inhibition was observed at 100 microns (41 +/- 5.9% of controls) and at 50 microns (59 +/- 4.8% of controls), while the inhibitory activity of theophylline at 10 microns (71 +/- 8.9% of controls) was not statistically significant. This activity was maximal a…
Effects of bacterial lipopolysaccharides (LPS) and tumour necrosis factor-alpha (TNF alpha) on rat tracheal epithelial cells in culture: morphology, …
1996
Rat tracheal epithelial cells were cultured and the effects of LPS and TNF alpha on cell morphology, rate of proliferation and NO synthase activity were studied. NO synthase activity was determined by measuring the accumulation of 3H-L-citrulline during incubation of confluent monolayer with 3H-L-arginine. In untreated cells no significant 3H-L-citrulline formation was detected, and bradykinin and the calcium ionophore A 23187 failed to stimulate 3H-L-citrulline formation excluding a constitutively expressed, calcium-dependent NO synthase activity. After culturing the cells for 18 h in the presence of LPS (10 micrograms/ml) and TNF alpha (500 U/ml) a marked formation of 3H-L-citrulline coul…
Quantitative analysis of airway obstruction in lymphangioleiomyomatosis
2020
Lymphangioleiomyomatosis (LAM) is a rare, cystic lung disease with progressive pulmonary function loss caused by progressively proliferating LAM cells. The degree of airway obstruction has not been well investigated within the pathogenesis of LAM. Using a combination of ex vivo computed tomography (CT), microCT and histology, the site and nature of airway obstruction in LAM explant lungs was compared with matched control lungs (n=5 each). The total number of airways per generation, total airway counts, terminal bronchioles number and surface density were compared in LAM versus control. Ex vivo CT analysis demonstrated a reduced number of airways from generation 7 on (p<0.0001) in LAM compar…
Age-dependent regulation of antioxidant genes by p38α MAPK in the liver
2018
p38α is a redox sensitive MAPK activated by pro-inflammatory cytokines and environmental, genotoxic and endoplasmic reticulum stresses. The aim of this work was to assess whether p38α controls the antioxidant defense in the liver, and if so, to elucidate the mechanism(s) involved and the age-related changes. For this purpose, we used liver-specific p38α-deficient mice at two different ages: young-mice (4 months-old) and old-mice (24 months-old). The liver of young p38α knock-out mice exhibited a decrease in GSH levels and an increase in GSSG/GSH ratio and malondialdehyde levels. However, old mice deficient in p38α had higher hepatic GSH levels and lower GSSG/GSH ratio than young p38α knock-…
Radiation-Engineering of All Plastic Nanocomposite Films
2015
In recent years, polymer nanocomposites have fascinated scientists, engineers and industrialists on the premise that the creation of new and more performing polymeric materials is possible by the combination of different building blocks with controlled dimensions at the nanoscale. Unfortunately, uniform dispersion of the hetero-phase domains within the plastic matrix or on its surface often fails due to the unfavorable thermodynamics, thus resulting in migration and irreversible aggregation phenomena. In-situ generation of a dispersed hetero-phase within the same polymer matrix or in its precursors increases the chances of achieving a better control of morphology by eliminating the often cr…
Active properties of edible marine polysaccharide-based coatings containing Larrea nitida polyphenols enriched extract.
2020
The aim of this work was to develop active edible coatings based on marine polysaccharide matrices and polyphenols-enriched native plant extracts from arid and semiarid regions of Argentina. Initially, five plant extracts were characterized in terms of antioxidant, antibacterial and antiviral activity and the one with better biological properties and no toxicity or genotoxicity, Larrea nitida (Ln) extract, was incorporated into agar, alginate or agar/alginate matrices. The Ln extract-containing films were characterized in terms of physicochemical and polyphenols release performance in food simulants. The incorporation of Ln extract provided darker films, with a more saturated orange-brownis…
The conservation and diversity of ascidian cells and molecules involved in the inflammatory reaction: The Ciona robusta model
2021
Ascidians are marine invertebrate chordates belonging to the earliest branch (Tunicata) in the chordate phylum, therefore, they are of interest for studying the evolution of immune systems. Due to the known genome, the non-colonial Ciona robusta, previously considered to be C. intestinalis type A, is a model species for the study of inflammatory response. The internal defense of ascidians mainly relies on hemocytes circulating in the hemolymph and pharynx. Hemocytes can be in vivo challenged by LPS injection and various granulocyte and vacuolated cell populations differentiated to produce and release inflammatory factors. Molecular biology and gene expression studies revealed complex defens…
Release of isoamyl acetate from starch pastes of various structures : thermodynamic and kinetic parameters
2004
The release of isoamyl acetate from starch-based matrices was studied on the basis of a cumulative dynamic headspace analysis. Two corn starches were compared, which are known to yield pastes and gels differing in their structures and properties. These properties were assessed by viscometry and viscoelastic measurements. Aroma release was discussed as a function of the structure and texture parameters of the matrix. The release curves obtained from water and from the various starch-based matrices at 25 degrees C showed similar patterns but differed in their initial slopes and in the final plateau values. The lowest initial slopes were obtained for the normal starch dispersions that formed g…