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Mucosal Protection (mucosal + protection)

Distribution by Scientific Domains

Medical Sciences	75%
Life Sciences	25%

Selected Abstracts

Intranasal immunisation with inactivated RSV and bacterial adjuvants induces mucosal protection and abrogates eosinophilia upon challenge

EUROPEAN JOURNAL OF IMMUNOLOGY, Issue 5 2006
Nathalie Etchart
Abstract We have previously shown that following intranasal exposure to influenza virus, specific plasma cells are generated in the nasal-associated lymphoid tissue (NALT) and maintained for the life of the animal. However, we also showed that following infection with respiratory syncytial virus (RSV), specific plasma cells are generated in the NALT but wane quickly and are not maintained even after challenge, even though RSV-specific serum antibody responses remain robust. Only infection with influenza virus generated sterilising immunity, implying a role for these long-lived plasma cells in protection. We show here that the RSV-specific IgA NALT plasma cell population and lung antibody levels can be substantially boosted, both at acute and memory time points, by intranasal immunisation with inactivated RSV (iRSV) in combination with bacterial outer membrane vesicles (OMV) compared to live RSV alone. Finally, challenge with live RSV showed that immunisation with iRSV and OMV protect against both virus replication in the lung and the eosinophil infiltrate generated by either live RSV or iRSV alone. These data show that immunisation with iRSV and OMV maintains a NALT RSV-specific plasma cell population and generates an efficient protective immune response following RSV infection. See accompanying commentary: http://dx.doi.org/10.1002/eji.200636118 [source]

Protective effect of alpha-tocopherol in head and neck cancer radiation-induced mucositis: A double-blind randomized trial,,

HEAD & NECK: JOURNAL FOR THE SCIENCES & SPECIALTIES OF THE HEAD AND NECK, Issue 4 2004
Paulo Renato Ferreira MD
Abstract Background. the study was designed to test whether vitamin E (VE) provides oral mucosal protection in patients with irradiated cancers of the head and neck. Methods. Fifty-four patients with cancer of the oral cavity and oropharynx were randomly assigned to rinse the oral cavity in an oil solution containing either VE or placebo before every conventional fraction of 2 Gy and again 8 to 12 hours later during the 5 to 7 weeks of radiotherapy (RT). Results. Thirty-six events/167 patient-weeks (21.6%) and 54 events/161 patient-weeks (33.5%) of symptomatic mucositis were observed in VE and placebo groups, respectively (p = .038). VE reduced the risk by 36%. Subjective data at the end of the treatment revealed that VE decreased pain grades 2 to 3 during RT (3 of 28 patients vs 14 of 26 patients, p = .0001). No significant influence was detected in survival. Conclusion. VE decreased the incidence of symptomatic oral radio-induced mucositis in patients with cancer of the oropharynx and oral cavity. © 2004 Wiley Periodicals, Inc. Head Neck26: XXX,XXX, 2004 [source]

Thickness and continuity of the adherent colonic mucus barrier in active and quiescent ulcerative colitis and Crohn's disease

INTERNATIONAL JOURNAL OF CLINICAL PRACTICE, Issue 5 2008
V. Strugala
Summary Background:, The colon is covered by a mucus barrier that protects the underlying mucosa and alterations in this mucus barrier have been implicated in the aetiology of inflammatory bowel disease (IBD). This study investigated the thickness and continuity of the mucus barrier in ulcerative colitis (UC) and Crohn's disease (CD) in comparison to normal controls. Methods:, Rectal biopsies were taken from 59 patients and cryostat sections stained with periodic acid-Schiff's/Alcian blue to visualise the mucus layer. Mucus thickness and continuity and goblet cell density were measured using light microscopy. Results:, An essentially continuous adherent mucus layer was observed in normal human rectum and there was no change in the mucus barrier in quiescent UC. In active UC there was a trend for the mucus layer to become progressively thinner and significantly more discontinuous as disease severity increased. In severe active UC the mucus layer thickness and goblet cell density were significantly reduced compared with normal controls while the percentage discontinuity significantly increased. Conclusion:, It is not until severe UC that there is a global change in mucosal protection as a consequence of large regions lacking mucus, a decrease in secretory potential caused by a loss of goblet cells and a thinner, less effective mucus layer even when it is present. [source]

Peroxiredoxin I protects gastric mucosa from oxidative injury induced by H. pylori infection

JOURNAL OF GASTROENTEROLOGY AND HEPATOLOGY, Issue 4 2008
Daisuke Sato
Abstract Background and Aim:, Helicobacter pylori (H. pylori) infection enhances the production of reactive oxygen species and peroxynitrite, thereby resulting in oxidative tissue damage. In this study, we examined the role of peroxiredoxin I (Prx I), a stress-induced antioxidant enzyme, in protecting gastric mucosa from H. pylori -induced gastric mucosal injury. Methods:, Wild type (Prx I+/+) and Prx I-deficient type (Prx I,/,) mice were maintained for 2 to 12 months with or without infection of H. pylori, Sydney strain-1. Gastric mucosal expression of Prx I was assessed by immunoblot analysis and immunohistochemistry. The degree of gastritis was evaluated by the updated Sydney system and by mucosal levels of inflammatory cytokines (MIP-2, IL-1,, and TNF-,). Oxidative DNA injury and apoptosis were analyzed by mucosal level of 8-hydroxy-2,-deoxyguanosine, and the number of apoptotic cells stained with a single-stranded DNA antibody, respectively. Results:,H. pylori infection upregulated gastric mucosal Prx I expression in the Prx I+/+ but not the Prx I,/, mice. H. pylori infection also induced more severe gastritis and a more prominent increase in MIP level, more marked oxidative DNA injury, and apoptosis in the Prx I,/, than the Prx I+/+ mice. In the absence of H. pylori infection, no changes were demonstrated in gastric mucosa in either the Prx I+/+ or the Prx I,/, mice. Conclusion:, These data suggest that H. pylori infection upregulates gastric mucosal Prx I expression, and further, that Prx I plays an important role in gastric mucosal protection against oxidative injury induced by H. pylori infection. [source]

Sensory neurone responses to mucosal noxae in the upper gut: relevance to mucosal integrity and gastrointestinal pain

NEUROGASTROENTEROLOGY & MOTILITY, Issue 5 2002
P. Holzer
Abstract ,The digestive tract is supplied by extrinsic and intrinsic sensory neurones that, together with endocrine and immune cells, form a surveillance network that is essential to gut function. This article focuses on the responses of extrinsic afferent neurones to chemical insults of the gastrointestinal mucosa and their pathophysiological relevance to mucosal integrity and abdominal pain. Within the gastroduodenal region, spinal afferents subserve an emergency function because, in case of alarm by influxing acid, they stimulate mechanisms of mucosal protection via an efferent-like release of transmitters. Other sensory neurones signal chemical noxae to the brain, a task that is not confined to spinal afferents because vagal afferents communicate gastric acid and peripheral immune challenges to the brainstem and in this way elicit autonomic, endocrine, affective and behavioural reactions. Emerging evidence indicates that hypersensitivity of extrinsic afferent pathways to mechanical and chemical stimuli makes an important contribution to the abdominal hyperalgesia seen in functional dyspepsia and irritable bowel syndrome. Sensitization may be brought about by inflammatory processes that lead to up-regulation and functional alterations of receptors and ion channels on sensory neurones. Such sensory neurone-specific molecules, which include vanilloid (capsaicin) receptors, may represent important targets for novel drugs to treat abdominal pain. [source]

Nuclear receptors of the enteric tract: guarding the frontier

NUTRITION REVIEWS, Issue 2008
Daniel R Schmidt
In addition to its classical role in mineral homeostasis, the vitamin D receptor has been implicated in diverse physiologic and pathophysiologic processes including immunoregulation and cancer. Interestingly, the vitamin D receptor has been evolutionarily and functionally linked to a select group of nuclear receptors based on a common organism-wide tissue expression profile. These members of the nuclear receptor superfamily, which include the bile acid receptor, xenobiotic receptors, and several orphan nuclear receptors, comprise a transcriptional regulatory network that functions in nutrient uptake, xenobiotic metabolism, and mucosal protection. The major homeostatic functions of the enteric nuclear receptor network are the topic of this review. [source]

Structure of the Oesophagus and Morphometric, Histochemical,Immunohistochemical Profiles of the Oesophageal Gland During the Post-hatching Period of Japanese Quails (Coturnix coturnix japonica)

ANATOMIA, HISTOLOGIA, EMBRYOLOGIA, Issue 5 2009
H. Sa
Summary In the oesophagus, mucins, which originate from oesophageal submucosal glands, play an important role in the mucosal protection as a pre-epithelial barrier. In this study, the structure of cervical and thoracic parts of oesophagus of Japanese quail during the post-hatching period was compared, and the contents of carbohydrate and gastric mucin MUC5AC of the oesophageal glands in these parts were analysed at the light microscope levels by applying conventional histochemical and immunohistochemical methods. The oesophageal glands were present at hatching, located in the laminae propria. The numbers of glands were different in the cervical and thoracic parts, but the differences were found to be insignificant. The thoracic part has the oesophageal tonsils which are associated with the glands. Oesophageal tonsil was formed from day 5 after hatching. In quail of all ages, the secretory epithelium of glands contained neutral sialomucins and weakly sulphomucins. The cells in the neck region of secretory units contained sialomucins, while the cells of excretory ducts had strongly sulphomucins. Sialomucin containing cells in the secretory units increased with the advance of age and glandular development. But, in the secretory units, the sulphomucin content of glands was more in the thoracic part. The secretory epithelium of tonsil-associated glands contained mostly sulphomucins and a little sialomucin. From the hatching, MUC5AC mucin was detected in the cells of excretory ducts. Although the lymphoepithelium of the tonsil units exhibited negative reactions to all histochemical methods, it showed positive reaction to MUC5AC mucin antibody. In conclusion, the cervical and thoracic parts may be functionally different and the thoracic part of oesophagus was transformed into an immunological organ following day 5 after hatching. [source]

Properties of fucoidan from Cladosiphon okamuranus tokida in gastric mucosal protection

BIOFACTORS, Issue 4 2000
Hideyuki Shibata
Abstract To elucidate the anti-ulcer potential of Cladosiphon fucoidan, anti-peptic activity, bFGF stabilizing activity and inflammatory properties of this and related substances were investigated. Anti-peptic activity was observed with this and other sulfated polysaccharides such as dextran sulfate, carrageenan, and Fucus fucoidan. However, non-sulfated polysaccharides such as mannan and dextran did not exert the anti-peptic activity. The loss of bFGF bioactivity was prevented by all sulfated polysaccharides tested except chondroitin sulfate, at pH 7.4 and at pH 4.0. At pH 2.0, only heparin protected the bFGF activity. The generation of superoxide by macrophages and PMNs was stimulated by dextran sulfate, carrageenan, and Fucus fucoidan, whereas Cladosiphon fucoidan, heparin and chondroitin did not. Dextran sulfate, carrageenan, and Fucus fucoidan also stimulated the secretion of TNF, from macrophages, while Cladosiphon fucoidan did not. Thus, Cladosiphon fucoidan is a sulfated polysaccharide without inflammatory action. These results suggest that Cladosiphon fucoidan is a safe substance with potential for gastric protection. [source]