The Experts below are selected from a list of 129 Experts worldwide ranked by ideXlab platform
Han Jianfen - One of the best experts on this subject based on the ideXlab platform.
-
the iga anti toxoplasma gondii antibody profiles in sera and Intestinal Secretions of the orally infected balb c mice
Journal of Tropical Medicine, 2004Co-Authors: Han JianfenAbstract:Objective This study was performed to determine the mucosal immune response following Toxoplasma gondii oral infection and observe the responses of IgA antibodies in sera and Intestinal Secretions in BALB/c mice. Methods Six- to 8-week-old BALB/c mice were divided into control group and infected group. The ascites containing tachyzoites of RH strain of infected mice were collected and adjusted to 5×10~4 tachyzoites per 0.5ml. The infected group was orally feeded with 5×10~4 tachyzoites, while the control group was given PBS solution instead. Five mice in each group were killed per time-point at day 2, 4, 6, 8, 10, 13, 16, 19, 22, and 25 after infection. The sera and Intestinal Secretions were obtained and the anti-T. gondii IgA antibodies were detected by ELISA. Results The level of IgA antibody in the sera and Intestinal Secretions were changed greatly. In the sera, IgA antibody persisted at low level until the 8th day post infection (pi), then it was gradually increased and reached maximum at day 10pi. It was then declined to the level of the control group, but had tendency of increase around day 25pi. Compare with the control group, the anti-T. gondii IgA showed a great increase at day 10 and day 25pi. The IgA antibody level in the Intestinal Secretions was higher than that in the sera. They increased with the time after infection and reached the peak at day 13pi with a sudden decline at day 8. The antibody level in the Intestinal Secretions between the infected and the control group showed extraordinary difference at day 8 and 13pi. Conclusion During the period of infection in the BALB/c mice orally administered with toxoplasma, the IgA antibody in the Intestinal Secretions was the major effector at the local site as the first protective barrier defending the parasite. The time course of IgA production and its fluctuation were influenced by the strain virulence and the immunity properties of the mice.
Donald G Weir - One of the best experts on this subject based on the ideXlab platform.
-
mucosal and systemic iga anti gliadin antibody in celiac disease contrasting patterns of response in serum saliva and Intestinal Secretions
Digestive Diseases and Sciences, 1991Co-Authors: Ciaran P Kelly, C Feighery, Richard B Gallagher, M J Gibney, Donald G WeirAbstract:Serum IgA anti-gliadin antibody estimation is a recognized screening method for celiac disease. However, celiac disease is primarily a small Intestinal mucosal disorder, and so we have examined the possibility that secreted, mucosal IgA anti-gliadin antibody might provide a more relevant measure of gluten sensitivity than that obtained from serum tests. Serum IgA anti-gliadin antibody and serum, salivary, and small Intestinal aspirate IgA anti-gliadin antibody were measured by enzyme-linked immunosorbent assay. Serum IgA and IgG anti-gliadin antibody were markedly increased in untreated celiacs (N=31) as compared to normals (N=20) or disease controls (N=39) (P<0.0001). Levels were lower in treated (N=30) than untreated celiacs (P<0.001). In Intestinal aspirates both untreated and treated patients had similar levels of IgA anti-gliadin antibody (P=0.48), but both were significantly higher than in controls (P<0.01). Salivary IgA anti-gliadin antibody, by contrast, was not increased in celiac patients as compared to controls. Serum IgA anti-gliadin antibody was the most sensitive (84%) and specific (95%) test for detecting untreated celiac disease. It was also the most useful in patient follow-up where it provides an early objective indicator of adherence to a gluten-free diet. Mucosal IgA responses to gliadin in celiac disease appear to be compartmentalized, with different portions of the gastroIntestinal tract functioning as separate immunological organs. Our results also demonstrate that serum and secretory IgA production are under independent control.
Bernard P Arulanandam - One of the best experts on this subject based on the ideXlab platform.
-
contribution of polymeric immunoglobulin receptor to regulation of Intestinal inflammation in dextran sulfate sodium induced colitis
Journal of Gastroenterology and Hepatology, 2006Co-Authors: Ashlesh K Murthy, Candice N Dubose, Jeffrey A Banas, Jacqueline J Coalson, Bernard P ArulanandamAbstract:Background Inflammatory bowel disease (IBD) affects approximately 4 million people worldwide and can be caused by dysregulated mucosal immune responses to the Intestinal commensal microflora. Immunoglobulin A (IgA) is considered to be the principal antibody in Intestinal Secretions and functions to prevent commensals and pathogenic organisms from gaining access to epithelial cell surfaces. Immunoglobulin A deficiency in humans has been associated with celiac disease and ulcerative colitis. However, the precise role of IgA in the pathogenesis of these disorders is yet to be fully understood. Methods Mice with a targeted disruption in IgA production (IgA(-/-) mice) and polymeric immunoglobulin receptor (pIgR(-/-) mice) were analyzed for the contribution of secretory immunity in the pathogenesis of dextran sulfate sodium (2.5%)-induced colitis. Results It was found that dextran sulfate sodium-treated pIgR(-/-) mice displayed greater loss of bodyweight and had severe clinical illness compared to similarly treated IgA(-/-) mice and wild-type animals. Additionally, colonic tissues from the pIgR(-/-) mice exhibited progressively and significantly greater degrees of mucosal edema, ulceration, crypt abscesses and macrophage infiltration when compared to similarly treated IgA(-/-) mice and wild-type animals. Conclusions The results indicate that secretory immunoglobulins contribute to protection of the colonic mucosa against dextran sulfate sodium-induced epithelial injury, although the isotype of the secretory immunoglobulin (IgA or IgM) may not be a decisive factor in such protection. Collectively, the pIgR and/or the secretory component are important for the maintenance of epithelial integrity and mucosal homeostasis in the colonic epithelium.
Ciaran P Kelly - One of the best experts on this subject based on the ideXlab platform.
-
mucosal and systemic iga anti gliadin antibody in celiac disease contrasting patterns of response in serum saliva and Intestinal Secretions
Digestive Diseases and Sciences, 1991Co-Authors: Ciaran P Kelly, C Feighery, Richard B Gallagher, M J Gibney, Donald G WeirAbstract:Serum IgA anti-gliadin antibody estimation is a recognized screening method for celiac disease. However, celiac disease is primarily a small Intestinal mucosal disorder, and so we have examined the possibility that secreted, mucosal IgA anti-gliadin antibody might provide a more relevant measure of gluten sensitivity than that obtained from serum tests. Serum IgA anti-gliadin antibody and serum, salivary, and small Intestinal aspirate IgA anti-gliadin antibody were measured by enzyme-linked immunosorbent assay. Serum IgA and IgG anti-gliadin antibody were markedly increased in untreated celiacs (N=31) as compared to normals (N=20) or disease controls (N=39) (P<0.0001). Levels were lower in treated (N=30) than untreated celiacs (P<0.001). In Intestinal aspirates both untreated and treated patients had similar levels of IgA anti-gliadin antibody (P=0.48), but both were significantly higher than in controls (P<0.01). Salivary IgA anti-gliadin antibody, by contrast, was not increased in celiac patients as compared to controls. Serum IgA anti-gliadin antibody was the most sensitive (84%) and specific (95%) test for detecting untreated celiac disease. It was also the most useful in patient follow-up where it provides an early objective indicator of adherence to a gluten-free diet. Mucosal IgA responses to gliadin in celiac disease appear to be compartmentalized, with different portions of the gastroIntestinal tract functioning as separate immunological organs. Our results also demonstrate that serum and secretory IgA production are under independent control.
Richard P H Thompson - One of the best experts on this subject based on the ideXlab platform.
-
the regulation of mineral absorption in the gastroIntestinal tract
Proceedings of the Nutrition Society (United Kingdom), 1999Co-Authors: Jonathan J Powell, Ravin Jugdaohsingh, Richard P H ThompsonAbstract:The absorption of metal ions in the mammalian single-stomached gut is fortunately highly selective, and both luminal and tissue regulation occur. Initially, assimilation of metal ions in an available form is facilitated by the Intestinal Secretions, chiefly soluble mucus (mucin) that retards hydrolysis of ions such as Cu, Fe and Zn. Metal ions then bind and traverse the mucosally-adherent mucus layer with an efficiency M+ > M2+ > M3+. At the mucosa Fe3+ is probably uniquely reduced to Fe2+, and all divalent cations (including Fe2+) are transported by a membrane protein (such as divalent cation transporter 1) into the cell. This minimizes absorption of toxic trivalent metals (e.g. A13+). Intracellular metal-binding molecules (such as mobilferrin) may be present at the intracellular side of the apical membrane, anchored to a transmembrane protein such as an integrin complex. This mobilferrin would receive the metal ion from divalent cation transporter 1 and, with part of the integrin molecule, transport the metal to the cytosol for safe sequestration in a larger complex such as ferritin or‘paraferritin’. β2-Microglobulin and HFE (previously termed human leucocyte antigen H) may be involved in stabilizing metal mobilferrin-integrin to form this latter complex. Finally, a systemic metal-binding protein such as transferrin may enter the antiluminal (basolateral) side of the cell for binding of the sequestered metal ion and delivery to the circulation. Regulatory proteins, such as HFE, may determine the degree of ion transport from Intestinal cells to the circulation. Gradients in pH and perhaps pCa or even pNa could allow the switching of ions between the different transporters throughout this mechanism.
-
the regulation of mineral absorption in the gastroIntestinal tract
The Proceedings of the Nutrition Society, 1999Co-Authors: Jonathan J Powell, Ravin Jugdaohsingh, Richard P H ThompsonAbstract:The absorption of metal ions in the mammalian single-stomached gut is fortunately highly selective, and both luminal and tissue regulation occur. Initially, assimilation of metal ions in an available form is facilitated by the Intestinal Secretions, chiefly soluble mucus (mucin) that retards hydrolysis of ions such as Cu, Fe and Zn. Metal ions then bind and traverse the mucosally-adherent mucus layer with an efficiency M+ > M2+ > M3+. At the mucosa Fe3+ is probably uniquely reduced to Fe2+, and all divalent cations (including Fe2+) are transported by a membrane protein (such as divalent cation transporter 1) into the cell. This minimizes absorption of toxic trivalent metals (e.g. Al3+). Intracellular metal-binding molecules (such as mobilferrin) may be present at the intracellular side of the apical membrane, anchored to a transmembrane protein such as an integrin complex. This mobilferrin would receive the metal ion from divalent cation transporter 1 and, with part of the integrin molecule, transport the metal to the cytosol for safe sequestration in a larger complex such as ferritin or 'paraferritin'. beta 2-Microglobulin and HFE (previously termed human leucocyte antigen H) may be involved in stabilizing metal mobilferrin-integrin to form this latter complex. Finally, a systemic metal-binding protein such as transferrin may enter the antiluminal (basolateral) side of the cell for binding of the sequestered metal ion and delivery to the circulation. Regulatory proteins, such as HFE, may determine the degree of ion transport from Intestinal cells to the circulation. Gradients in pH and perhaps pCa or even pNa could allow the switching of ions between the different transporters throughout this mechanism.
