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Mucus Layer (mucus + layer)
Selected AbstractsBacterial population analysis of human colon and terminal ileum biopsies with 16S rRNA-based fluorescent probes: Commensal bacteria live in suspension and have no direct contact with epithelial cellsINFLAMMATORY BOWEL DISEASES, Issue 10 2005Laurens A van der Waaij PhD Abstract Background: The commensal intestinal microflora has important metabolic and perhaps also immune modulatory functions. Evidence has accumulated that the microflora plays a role in the pathogenesis of inflammatory bowel disease. Therefore, there is a growing interest in the intestinal microflora and its interaction with the host. Presumably, this interaction takes place at the mucus layer. In this study, we investigated the microflora that is present at the mucus layer and addressed the following questions. Does a specific mucus-adherent microflora exist? Is there direct contact between commensal bacteria and epithelial cells? Methods: Snap-frozen biopsies were taken of 5 colon regions and of the terminal ileum in 9 subjects with a normal colon. Fecal samples were also collected. Bacteria were detected in cryosections with fluorescent in situ hybridization (FISH) with 16S ribosomal (r)RNA-targeted probes for all bacteria and specific probes for the major representatives of anaerobic microflora (bifidobacteria, Bacteroides, clostridia, atopobia) and aerobic microflora (Enterobacteriaceae, enterococci, streptococci, lactobacilli). Results: With this sensitive technique, bacteria were only observed at the luminal side of the intestinal mucus layer. Very few microcolonies were present at the mucus layer, and the composition of the bacterial microflora present in the feces was similar to that at the mucus layer of the terminal ileum and colon regions. Conclusions: We did not observe direct contact between bacteria and epithelial cells. The equal distribution of bacterial species suggests that intestinal commensal bacteria live in suspension in the lumen and that there is no specific mucus-adherent microflora. [source] Thickness and continuity of the adherent colonic mucus barrier in active and quiescent ulcerative colitis and Crohn's diseaseINTERNATIONAL JOURNAL OF CLINICAL PRACTICE, Issue 5 2008V. 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] Development and in vitro evaluation of a mucoadhesive vaginal delivery system for nystatinJOURNAL OF PHARMACEUTICAL SCIENCES, Issue 2 2009Juliane Hombach Abstract The purpose of the present study was to design and evaluate a novel vaginal delivery system for nystatin based on mucoadhesive polymers. L -Cysteine and cysteamine, respectively, were covalently attached to poly(acrylic acid), and the two different thiolated polymers were evaluated in vitro regarding their swelling behavior, mucoadhesive properties and release behavior. Tablets comprising these thiolated polymers and nystatin demonstrated a high stability in vaginal fluid simulant pH 4.2 and an increase in weight by swelling whereas control tablets comprising unmodified poly(acrylic acid) disintegrated and dissolved. The mucoadhesion time of tablets on freshly excised bovine vaginal mucosa on a rotating cylinder and the total work of adhesion of gels and tablets increased significantly due to the formation of disulfide bonds between the thiolated polymer and cysteine rich subdomaines of the mucus layer. The drug nystatin was released more slowly out of thiomer tablets and gels than out of PAA control tablets and gels. Therefore these thiolated polymers are promising delivery systems for nystatin providing a prolonged residence time and a sustained drug release in vitro under physiological relevant conditions. © 2008 Wiley-Liss, Inc. and the American Pharmacists Association J Pharm Sci 98:555,564, 2009 [source] Low-frequency dielectric spectroscopy as a tool for studying the compatibility between pharmaceutical gels and mucous tissueJOURNAL OF PHARMACEUTICAL SCIENCES, Issue 9 2003Helene HäGerström Abstract This interdisciplinary work demonstrates how low-frequency dielectric spectroscopy, a technique that is frequently used within physics, can be used to assess the possibilities of intimate surface contact between a polymer gel and mucous tissue, which is generally considered to be the first step in the mucoadhesion process. The dielectric responses of five different gels, of freshly excised porcine nasal mucosa and of systems made by combining the two were measured. All spectra were modeled by a Randles electric circuit containing a diffusion element, a barrier resistance in parallel with a capacitance, and a high-frequency resistance. The results were used to create a measure of the compatibility between the gel and the mucus, which we have named the compatibility factor. Thus, the compatibility factor provides us with a measure of the ease with which a charged species passes the interface between a gel and the mucus layer. The compatibility factor is calculated from the high frequency (kHz region) response of the gel, of the mucosa, and of the combined system. The two highest compatibility factors in this study were obtained for gels based on crosslinked poly(acrylic acid) and chitosan, which was in agreement with the results from mucoadhesion measurements that were performed using a tensile strength method. © 2003 Wiley-Liss, Inc. and the American Pharmacists Association J Pharm Sci 92:1869,1881, 2003 [source] Hypersalinity enhances the production of extracellular polymeric substance (eps) in the texas brown tide alga, aureoumbra lagunensis (PELAGOPHYCEAE)JOURNAL OF PHYCOLOGY, Issue 1 2000Hongbin Liu Laboratory experiments with batch cultures showed that the Texas brown tide alga, Aureoumbra lagunensis Stockwell, DeYoe, Hargraves et Johnson, produced a large amount of extracellular polymeric substance (EPS) that formed an extracellular polysaccharide mucus layer. Both dissolved and particulate carbohydrate and EPS concentrations increased as A. lagunensis cultures progressed from exponential growth phase, through stationary phase, to declining phase. Particulate carbohydrate and EPS concentrations per cell were more than three times higher during the declining phase than that in exponential growth phase, reflecting a large increase in the EPS mucus layer. The amounts of carbohydrate and EPS produced by A. lagunensis were significantly higher under hypersaline conditions. The thicker EPS mucus layer surrounding A. lagunensis cells under hypersaline conditions might be a protective adaptation that permits it to bloom under hypersaline conditions that most other phytoplankton cannot survive. This could be one of the reasons why the Texas brown tide persisted in the Laguna Madre, an often hypersaline coastal lagoon, for 7 years. [source] Treatment of Helicobacter pylori infection with intra-gastric violet light phototherapy: A pilot clinical trial,LASERS IN SURGERY AND MEDICINE, Issue 5 2009Anthony J. Lembo MD Abstract Background and Objective Helicobacter pylori infects the mucus layer of the human stomach and causes peptic ulcers and adenocarcinoma. We have previously shown that H. pylori accumulates photoactive porphyrins making the organism susceptible to inactivation by light, and that small spot endoscopic illumination with violet light reduced bacterial load in human stomachs. This study assessed the feasibility and safety of whole-stomach intra-gastric violet phototherapy for the treatment of H. pylori infection. Study Design/Materials and Methods A controlled, prospective pilot trial was conducted using a novel light source consisting of laser diodes and diffusing fibers to deliver 408-nm illumination at escalating total fluences to the whole stomach. Eighteen adults (10 female) with H. pylori infection were treated at three U.S. academic endoscopy centers. Quantitative bacterial counts were obtained from biopsies taken from the antrum, body, and fundus, and serial urea breath tests. Results The largest reduction in bacterial load was in the antrum (>97%), followed by body (>95%) and fundus (>86%). There was a correlation between log reduction and initial bacterial load in the antrum. There was no dose,response seen with increasing illumination times. The urea breath test results indicated that the bacteria repopulated in days following illumination. Conclusion Intra-gastric violet light phototherapy is feasible and safe and may represent a novel approach to eradication of H. pylori, particularly in patients who have failed standard antibiotic treatment. This was a pilot study involving a small number of patients. Further research is needed to determine if phototherapy can be effective for eradicating H. pylori. Lasers Surg. Med. 41:337,344, 2009. © 2009 Wiley-Liss, Inc. [source] Helicobacter pylori in patients can be killed by visible lightLASERS IN SURGERY AND MEDICINE, Issue 4 2005Robert A. Ganz MD Abstract Background Helicobacter pylori colonizes the mucus layer of the human stomach and may cause peptic ulcer and adenocarcinoma. Novel antimicrobial approaches are sought due to the occurrence of antibiotic resistance and consequent treatment failure. We report here that H. pylori is susceptible to inactivation by blue light. Study Design/Materials and Methods A controlled, prospective, blinded, trial of endoscopically delivered blue light to eradicate H. pylori in regions of the gastric antrum, in 10 patients between the ages of 21 and 80 who tested positive for H. pylori. Light (405 nm) (40 J/cm2) was delivered to a 1-cm diameter spot in the gastric antrum via optical fiber passed through the endoscope and weighed biopsies were taken from treated and control spots and colonies quantitatively cultured. Results Blue light killed 5 logs of bacteria in vitro. The mean reduction in H. pylori colonies per gram tissue between treated and control spots was 91% (7.4±4.8×106 vs. 8.1±1.9×107, two-tailed P<0.0001). Some patients had reductions approaching 99%. No differences were observed on histological examination of light-treated and control gastric tissue. Conclusion Blue light phototherapy may represent a novel approach to eradication of H. pylori, particularly, in patients who have failed standard antibiotic treatment. © 2005 Wiley-Liss, Inc. [source] Lectin Histochemical Aspects of Mucus Function in the Oesophagus of the Reticulated Python (Python reticulatus)ANATOMIA, HISTOLOGIA, EMBRYOLOGIA, Issue 4 2009W. Meyer Summary Using lectin histochemistry, the study characterizes basic functional aspects of the mucus produced by the oesophageal epithelium of the Reticulated python (Python reticulatus). Reaction staining varied as related to the two epithelium types present, containing goblet cells and ciliary cells. Remarkable intensities were achieved especially in the luminal mucus layer and the fine mucus covering the epithelial ciliary border for Con A (,-D-Man; ,-D-Glc) as part of neutral glycoproteins, Limax flavus agglutinin (NeuNac = NeuNgc), emphasizing that water binding hyaluronan provides a hydrated interface conductive to the passage of material and UEA-I (,-L-Fuc), corroborating the view that fucose-rich highly viscous mucus is helpful against mechanical stress during prey transport. [source] A real-life multicentre clinical practice study to evaluate the efficacy and safety of intravesical chondroitin sulphate for the treatment of interstitial cystitisBJU INTERNATIONAL, Issue 1 2009J. Curtis Nickel OBJECTIVE To report a multicentre, community based open-label study designed to assess the efficacy and safety of intravesical sodium chondroitin sulphate in the treatment of patients with the clinical diagnosis of interstitial cystitis (IC). Chondroitin sulphate is a naturally occurring glycosaminoglycan (GAG) in the bladder mucus layer and changes in this GAG have been implicated in the pathogenesis of IC, and small single-centre studies have suggested that intravesical chondroitin sulphate may have efficacy in IC. PATIENTS AND METHODS Patients with IC were treated with sodium chondroitin sulphate (Uracyst®, Stellar Pharmaceuticals Inc., London ON, Canada) solution 2.0% via urinary catheter weekly for 6 weeks and then monthly for 16 weeks for a total of 10 treatments. The primary efficacy endpoint was the percentage of responders to treatment as indicated by a marked or moderate improvement on a seven-point patient Global Response Assessment (GRA) scale at week 10 (4 weeks after the initial six treatments) compared with baseline. A major secondary efficacy endpoint (durability) was the percentage of responders on the GRA scale after 10 treatments. Additional secondary efficacy objectives were differences from baseline in Patient Symptom/Problem Index scores over the course of the treatment compared with baseline. RESULTS In all, 47% of the 53 enrolled patients with long standing moderately severe IC (mean [sd, range] diagnosis of IC 3.0 [3.4, 0.1,16] years; duration of symptoms 9.2 [9.2, 1,39] years; baseline symptom score 14.2 [3.2]) were responders at week 10. At 24 weeks, 60% were responders. There was a statistically and clinically significant decrease in the mean (sd) symptom and bother scores from baseline at 10 weeks and 24 weeks, at 9.0 (4.3) and 8.1 (5.0), respectively (P < 0.001). There were no significant safety issues during the study. CONCLUSIONS This multicentre community based real-life clinical practice study suggests that intravesical chondroitin sulphate may have an important role in the treatment of IC and validates the rationale for a randomized placebo-controlled trial. [source] | |||||||||||||