Search results for "MUCOSA"
showing 10 items of 1066 documents
Polyamines Impair Immunity to Helicobacter pylori by Inhibiting L-Arginine Uptake Required for Nitric Oxide Production
2010
International audience; BACKGROUND & AIMS: Helicobacter pylori-induced immune responses fail to eradicate the bacterium. Nitric oxide (NO) can kill H pylori. However, translation of inducible NO synthase (iNOS) and NO generation by H pylori-stimulated macrophages is inhibited by the polyamine spermine derived from ornithine decarboxylase (ODC), and is dependent on availability of the iNOS substrate L-arginine (L-Arg). We determined if spermine inhibits iNOS-mediated immunity by reducing L-Arg uptake into macrophages. METHODS: Levels of the inducible cationic amino acid transporter (CAT) 2, ODC, and iNOS were measured in macrophages and H pylori gastritis tissues. L-Arg uptake, iNOS expressi…
Histopathology of the gut in rheumatic diseases
2018
The gastrointestinal tract regulates the trafficking of macromolecules between the environment and the host through an epithelial barrier mechanism and is an important part of the immune system controlling the equilibrium between tolerance and immunity to non-self-antigens. Various evidence indicates that intestinal inflammation occurs in patients with rheumatic diseases. In many rheumatic diseases intestinal inflammation appears to be linked to dysbiosis and possibly represents the common denominator in the pathogenesis of different rheumatic diseases. The continuative interaction between dysbiosis and the intestinal immune system may lead to the aberrant activation of immune cells that ca…
Effects of cimetidine, atropine and prostaglandin E2 on rat mucosal erosions produced by intragastric distension
1980
Abstract The effects of three typical antisecretory agents: cimetidine, atrophine and prostaglandin E2 were compared on an acute rat gastric ulcer model which consisted of perfusing the stomach continuously, at a high intraluminal pressure (120 mm H2O), with a simulated gastric juice (0.1 M HCl plus 600 mg pepsin/1). As the acid and pepsin are given exogenously the inhibitory action of the antisecretory drugs is obviated in this model. Cimetidine and atropine failed to reduce gastric erosions, whereas prostaglandin E2 markedly reduced the severity of the mucosal lesions with respect to control values. Long-term treatment with cimetidine also failed to increase the resistance of the gastric …
Stimulated and unstimulated saliva samples have significantly different bacterial profiles
2018
Epidemiological studies use saliva on a regular basis as a non-invasive and easy-to-take sample, which is assumed to be a microbial representative of the oral cavity ecosystem. However, comparative studies between different kinds of saliva samples normally used in microbial studies are scarce. The aim of the current study was to compare oral microbiota composition between two different saliva samples collected simultaneously: non-stimulated saliva with paper points and stimulated saliva collected after chewing paraffin gum. DNA was extracted from saliva samples of ten individuals, then analyzed by 16S rRNA pyrosequencing to describe bacterial diversity. The results demonstrate significant d…
Clostridium difficile Toxins Disrupt Epithelial Barrier Function by Altering Membrane Microdomain Localization of Tight Junction Proteins
2001
ABSTRACT The anaerobic bacterium Clostridium difficile is the etiologic agent of pseudomembranous colitis. C. difficile toxins TcdA and TcdB are UDP-glucosyltransferases that monoglucosylate and thereby inactivate the Rho family of GTPases (W. P. Ciesla, Jr., and D. A. Bobak, J. Biol. Chem. 273:16021–16026, 1998). We utilized purified reference toxins of C. difficile , TcdA-10463 (TcdA) and TcdB-10463 (TcdB), and a model intestinal epithelial cell line to characterize their influence on tight-junction (TJ) organization and hence to analyze the mechanisms by which they contribute to the enhanced paracellular permeability and disease pathophysiology of pseudomembranous colitis. The increase i…
Mucoadhesive Polymeric Films to Enhance Barbaloin Penetration Into Buccal Mucosa: a Novel Approach to Chemoprevention.
2018
Nowadays, chemoprevention by administering natural supplements is considered an attractive strategy to reverse, suppress, or prevent the evolution of premalignant oral lesions. In particular, Barbaloin exhibits anti-proliferative, anti-inflammatory, and anti-cancer properties, and it results useful in multi-therapy with classic chemotherapeutics. Therefore, in this work, mucoadhesive buccal films, as locoregional drug delivery system able to provide a targeted and efficient therapeutic delivery of Barbaloin, are proposed. Thus, Aloin extract-loaded Eudragit (R) RL100 or Eudragit (R) RS100-based buccal films were designed in order to obtain an easily self-administrable formulation capable of…
Pro-and anti-fibrotic molecule balance in the bronchial mucosa of stable COPD patients
2015
Background: The mechanisms of inducing fibrotic events and remodeling in the airways of COPD are incompletely studied. Objectives: To investigate the expression of cytokines involved in the pro- and anti-fibrotic events in stable COPD. Methods: Expression of CTGF, TGFβ1-2-3, TGFβRI, TGFβRII, LTBP-1, TRAP-1, BAMBI, PP2Cα, Smad2-3-6-7, pSmad2, pSmad3, pro-collagen-I and collagen-I was measured in the bronchial mucosa using immunohistochemistry and RT-qPCR. Results: TGFβ1 was increased in the epithelium and TGFβ3 in the submucosa of healthy smokers and mild/moderate COPD compared to healthy non-smokers. In all smokers and patients with COPD TGFβ3+ cells in the submucosa correlated significantl…
Influence of capsaicin-sensitive afferent neurones on the acid secretory responses of the rat stomach in vivo.
1990
1. The influence of capsaicin-sensitive afferent neurones in modulating acid-secretory responses has been investigated in the continuously perfused stomach of the anaesthetized rat. 2. Ablation of primary afferent neurones, after systemic neonatal pretreatment with high doses of capsaicin, did not modify acid responses to direct stimuli of the oxyntic cell with histamine (5 mg kg-1), pentagastrin (20 micrograms kg-1) or carbachol (4 micrograms kg-1). 3. Acid responses to hypoglycaemia induced by insulin (0.3 iu kg-1) were not influenced by systemic capsaicin pretreatment or by acute coeliac ganglionectomy. Vagotomy abolished this secretory response. 4. The increase in acid output induced by…
Blood flow patterns spatially associated with platelet aggregates in murine colitis.
2009
In the normal murine mucosal plexus, blood flow is generally smooth and continuous. In inflammatory conditions, such as chemically-induced murine colitis, the mucosal plexus demonstrates markedly abnormal flow patterns. The inflamed mucosal plexus is associated with widely variable blood flow velocity as well as discontinuous and even bidirectional flow. To investigate the mechanisms responsible for these blood flow patterns, we used intravital microscopic examination of blood flow within the murine mucosal plexus during dextran sodium sulphate-and trinitrobenzenesulfonic acid-induced colitis. The blood flow patterns within the mucosal plexus demonstrated flow exclusion in 18% of the vessel…
Overexpression of bone morphogenetic protein-6 (BMP-6) in the epidermis of transgenic mice: inhibition or stimulation of proliferation depending on t…
1996
Bone morphogenetic protein-6 (BMP-6) belongs to the family of TGF-beta-related growth factors. In the developing epidermis, expression of BMP-6 coincides with the onset of stratification. Expression persists perinatally but declines after day 6 postpartum, although it can still be detected in adult skin by reverse transcriptase-polymerase chain reaction (RT-PCR) analysis. We constitutively overexpressed BMP-6 in suprabasal layers of interfollicular epidermis in transgenic mice using a keratin 10 promoter. All mice expressing the transgene developed abnormalities in the skin, indicating an active transgene-derived factor. Depending on the pattern of transgene expression, the effects on proli…