1,720,971 research outputs found
Interleukin-2 stimulates TGFbeta Production in epithelial cell line
No full textAbstract
The presence of receptors for the cytokine IL-2 was assessed in the IEC-6 cell line established from normal rat crypt epithelium and primary intestinal epithelial cells. 125I-IL-2 was found to specifically bind to subconfluent IEC-6 cells. Maximal binding was observed within 30 min after addition of the ligand; binding could be inhibited by excess unlabeled IL-2 or addition of antibody to the IL-2 receptor. Both intermediate and low affinity receptors with approximate Kd of 10 and 100 pM, respectively were present. Kinetic analysis were consistent with the results of Western blot analysis using an antisera to the 75-kD IL-2 receptor beta chain. IL-2 receptors appeared to be functional; addition of IL-2 led to modulation of proliferation with initial stimulation at 24 h followed by inhibition at 48 h. This effect could be blocked by addition of antibody to the IL-2 receptor beta chain. IL-2 treatment could be shown to enhance expression (range = 4- to 50-fold stimulation) of TGF-beta, as well as the lectin protein mac-2, in IEC-6 cells. The relevance of observations in the IEC-6 cell line to intestinal mucosa in vivo was supported by the demonstration of a gradient of expression of the IL-2 receptor in primary rat intestinal epithelial cells by Western blot analysis. In addition, mRNA for the IL-2 receptor-beta chain was demonstrated by Northern blot analysis using mRNA from primary rat intestinal epithelial cells depleted of detectable contaminating intraepithelial lymphocytes by two cycles of fractionation on Percoll gradients. Collectively, these observations suggest that the range of cellular targets of the putative lymphokine IL-2 is broader than appreciated, and IL-2 may serve to integrate epithelial and lymphocyte responses in the intestinal mucosa
Peptide growth factors: role in epithelial-lamina propria cell interactions
No full texthe intestinal mucosa is distinguished by a dynamic population of epithelial cells at its
surface which undergoes nearly complete turnover every few days. In adition to the
epithelium, the mucosa encompasses an underlying heterogenous population of immune
and other cell populations within the lamina propria. A number of observations suggest that
dynamic interactions occur between the epithelium and the immune cell populations present
in the lamina propria. These interactions may play an important role in both effectin
Macrophage and lymphocyte subpopulations in magnifying endoscopic lesions of Crohn's disease.
No full textUsing dye staining and a magnifying colonoscope, small lesions in the rectum of patients with Crohn's disease (which had otherwise appeared normal on sigmoidoscopy) can be detected. Subpopulations of macrophages and lymphocytes in the abnormal and adjacent normal areas of the rectum were studied using a panel of monoclonal antibodies. There was a distinct increase in RFD9+ and 3G8+ macrophages in the abnormal areas compared with the normal. The CD4:CD8 ratio of lymphocytes in the two areas remained unchanged
Interleukin-2 stimulates TGFbeta Production in epithelial cell line
No full textAbstract
The presence of receptors for the cytokine IL-2 was assessed in the IEC-6 cell line established from normal rat crypt epithelium and primary intestinal epithelial cells. 125I-IL-2 was found to specifically bind to subconfluent IEC-6 cells. Maximal binding was observed within 30 min after addition of the ligand; binding could be inhibited by excess unlabeled IL-2 or addition of antibody to the IL-2 receptor. Both intermediate and low affinity receptors with approximate Kd of 10 and 100 pM, respectively were present. Kinetic analysis were consistent with the results of Western blot analysis using an antisera to the 75-kD IL-2 receptor beta chain. IL-2 receptors appeared to be functional; addition of IL-2 led to modulation of proliferation with initial stimulation at 24 h followed by inhibition at 48 h. This effect could be blocked by addition of antibody to the IL-2 receptor beta chain. IL-2 treatment could be shown to enhance expression (range = 4- to 50-fold stimulation) of TGF-beta, as well as the lectin protein mac-2, in IEC-6 cells. The relevance of observations in the IEC-6 cell line to intestinal mucosa in vivo was supported by the demonstration of a gradient of expression of the IL-2 receptor in primary rat intestinal epithelial cells by Western blot analysis. In addition, mRNA for the IL-2 receptor-beta chain was demonstrated by Northern blot analysis using mRNA from primary rat intestinal epithelial cells depleted of detectable contaminating intraepithelial lymphocytes by two cycles of fractionation on Percoll gradients. Collectively, these observations suggest that the range of cellular targets of the putative lymphokine IL-2 is broader than appreciated, and IL-2 may serve to integrate epithelial and lymphocyte responses in the intestinal mucosa
Bacteroides fragilis enterotoxin (BFT) induces the expression of interleukin-8 (IL-8) and transforming growth factor beta (TGF-BETA) by human colonic epithelial cells
No full textBacteroides fragilis enterotoxin induces the expression of IL-8 and transforming growth factor-beta (TGF-b) by human colonic epithelial cells
No full textFunctional interleukin-2 receptors on intestinal epithelial cells
No full textThe presence of receptors for the cytokine IL-2 was assessed in the IEC-6 cell line established from normal rat crypt epithelium and primary intestinal epithelial cells.125I-IL-2 was found to specifically bind to subconfluent IEC-6 cells. Maximal binding was observed within 30 min after addition of the ligand; binding could be inhibited by excess unlabeled IL-2 or addition of antibody to the IL-2 receptor. Both intermediate and low affinity receptors with approximate Kdof 10 and 100 pM, respectively were present. Kinetic analysis were consistent with the results of Western blot analysis using an antisera to the 75-kD IL-2 receptor β chain. IL-2 receptors appeared to be functional; addition of IL-2 led to modulation of proliferation with initial stimulation at 24 h followed by inhibition at 48 h. This effect could be blocked by addition of antibody to the IL-2 receptor β chain. IL-2 treatment could be shown to enhance expression (range = 4- to 50-fold stimulation) of TGF-β, as well as the lectin protein mac-2, in IEC-6 cells. The relevance of observations in the IEC-6 cell line to intestinal mucosa in vivo was supported by the demonstration of a gradient of expression of the IL-2 receptor in primary rat intestinal epithelial cells by Western blot analysis. In addition, mRNA for the IL-2 receptor-β chain was demonstrated by Northern blot analysis using mRNA from primary rat intestinal epithelial cells depleted of detectable contaminating intraepithelial lymphocytes by two cycles of fractionation on Percoll gradients. Collectively, these observations suggest that the range of cellular targets of the putative lymphokine IL-2 is broader than appreciated, and IL-2 may serve to integrate epithelial and lymphocyte responses in the intestinal mucosa
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
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