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Biomedical subjects

L K Trejdosiewicz

Publications and source records attributed to L K Trejdosiewicz.

At least 55 records · Page 3Linked to original sources
PubMed1994

Mucosal interleukin-6 secretion in ulcerative colitis. Effects of anti-inflammatory drugs and T-cell stimulation.

BACKGROUND: We have studied modulation of mucosal interleukin-6 (IL-6) secretion by T-cell activation and by anti-inflammatory agents in inflammatory bowel disease. METHODS: In vitro secretion of IL-6 by biopsy specimens from patients with active ulcerative colitis was investigated in the presence of cyclosporin-A (CsA) and drugs that have other anti-inflammatory actions. Biopsy specimens from patients with quiescent ulcerative colitis or controls were stimulated with anti-CD3 antibody to activate mucosal T cells. RESULTS: Stimulation of control specimens increased IL-6 secretion (median increase, 147%; p < 0.003), which was prevented by CsA. In quiescent ulcerative colitis there was enhanced spontaneous secretion of IL-6 but a smaller, non-significant increase after T-cell activation (125%). Dexamethasone inhibited secretion in active ulcerative colitis (p < 0.006). 5-Aminosalicylic acid, 6-mercaptopurine, methotrexate, and indomethacin had no effect. There also tended to be a small reduction with CsA, but this just failed to reach statistical significance. CONCLUSIONS: In quiescent ulcerative colitis the enhanced spontaneous secretion of IL-6 may be a consequence of mucosal T-cell or macrophage activation: the smaller increase after T-cell stimulation suggests that one or both of these two cell types are already pre-activated.

Anti-Inflammatory Agents↗
PubMed1994

Normal human urothelial cells in vitro: proliferation and induction of stratification.

BACKGROUND: The purpose of the work was to establish urothelium as an in vitro model for the study of proliferation, stratification, and differentiation in "complex" epithelia. EXPERIMENTAL DESIGN: Normal human urothelial cells were cultured in a serum-free medium. The effects of epidermal growth factor (EGF), cholera toxin (CT), extracellular calcium and 13-cis-retinoic acid on cell growth, morphology, phenotype, and cytodifferentiation were studied using phase-contrast microscopy and indirect immunofluorescence. Stratification-related changes were additionally analyzed by transmission electron microscopy. RESULTS: Under optimized conditions, long-term cultures were successful in 44 (74.5%) out of 59 specimens. Bacterial infection was the most common cause of failure (9 cases). Primary urothelial cells required an initial plating density of > or = 10(4) cells/cm2 for survival; passaged cells survived much lower plating densities (> or = 2.5 x 10(2) cells/cm2). CT significantly improved cell attachment, but neither CT nor EGF were essential for growth. By contrast, cells failed to proliferate without bovine pituitary extract. In media containing bovine pituitary extract, CT, and EGF, cultures had a mean population doubling time of 14.7 +/- 1.8 hours, maintained a nonstratified phenotype, and expressed the cytokeratin (CK) profile of basal/intermediate urothelium: CK7, CK8, CK17, CK18 and CK19, with variable expression of CK13. CK20 was not expressed in vitro. CK14 and CK16 were also expressed, suggestive of squamous metaplasia in culture, which could be inhibited with 13-cis-retinoic acid. Increasing extracellular calcium from 0.09 to 0.9-4.0 mM slowed cell proliferation, induced stratification and desmosome formation, and increased expression of E-cadherin. High calcium, EGF, CT, and retinoic acid did not induce markers of late/terminal urothelial cytodifferentiation. CONCLUSIONS: We describe a simplified technique for the isolation and long-term culture of human urothelial cells. Urothelial cells in vitro are capable of rapid proliferation and can be induced to form integrated stratifying cell layers in high calcium medium. Stratification-related changes are not necessarily accompanied by urothelial cell maturation and differentiation.

Adolescent↗
PubMed1993

Urothelial tissue culture for bladder reconstruction: an experimental study.

An in vitro system for the growth of normal human urothelial cells has been developed. Urothelial cells were isolated from tissue samples in 38 patients and cultured in a defined serum-free medium. Confluent cell monolayers of 25 cm.2 were produced after 7 days in 32 cases. Subsequent subcultures at a 1:20 split ratio achieved confluency within another 7 days and a consistently high rate of growth was sustained for at least 7 passages. Characterization by immunofluorescence with a panel of antibodies demonstrated that the cultured cells were exclusively epithelial and retained the characteristic antigenic profile of normal urothelium, even after extended periods in culture. The only consistent cause of failure (6 of 38 cases) was bacterial contamination secondary to an underlying urinary tract infection in these patients.

Adolescent↗
PubMed1993

Beta-1 integrin cell adhesion molecules in the endometrium of fertile and infertile women.

In order to investigate whether the endometrium of women with unexplained infertility differs immunologically from the endometrium of normal fertile women, a panel of six monoclonal antibodies was used to characterize the presence of the beta 1-integrins or very-late-activation antigens (VLA) in the different endometrial compartments. Precisely timed endometrial biopsies at 4, 7, 10 and 13 days following the luteinizing hormone surge were obtained from 24 normal fertile women (group I) and 24 women suffering from unexplained infertility (group II). Frozen sections were labelled using an avidin-biotin peroxidase technique. VLA-1, VLA-2 and VLA-3 were present in glandular epithelium, stromal cells and vessels of both groups. VLA-4 was detected in group I but was absent from glandular and surface epithelium of group II. VLA-5 was not present in any of the specimens. VLA-6 was identified primarily in the basement membrane of vessels, glandular and surface epithelium in both patient groups. This study indicates that most beta 1-integrins are present in endometrium throughout the luteal phase of the menstrual cycle. The differences observed between the two groups may contribute to unexplained infertility.

Adult↗
PubMed1993

Peri-operative modulation of cellular immunity in patients with colorectal cancer.

The peri-operative cellular immune response is depressed in patients with gastrointestinal cancer, a factor which may facilitate malignant dissemination. We have investigated the effects of peri-operative rIL-2 and a combination of rIL-2 and interferon-alpha (IFN-alpha) on both peripheral blood lymphocyte function and number in patients undergoing surgical resection for colorectal cancer. Fifty-two patients were randomly allocated to either control, rIL-2 or rIL-2 with IFN-alpha treatment arms. In vitro studies were performed pre-operatively and on post-operative days 1, 4, 7 and 10. Natural killer (NK) and lymphokine-activated killer (LAK) cell function were profoundly depressed in control patients (P < 0.001; P < 0.01), an effect abrogated in both treatment groups; indeed NK function was augmented in the rIL-2 and IFN-alpha group on the first post-operative day in association with an increase in the percentage of cells expressing CD16 and CD56 (P < 0.01). Flow cytometric analysis of lymphocyte subsets in the control group was unremarkable, except for an early post-operative fall in numbers of lymphocytes. Treatment with either rIL-2 or rIL-2 and IFN-alpha produced an initial profound reduction in T lymphocyte numbers, followed by a 'rebound' lymphocytosis of activated CD3+ T cells, as demonstrated by a significant increase in co-expression of CD25, CD38 and CD45RO. No significant differences were observed between either of the treatment groups. Adjuvant immunotherapy affects peri-operative anti-tumour immune responses, and this may influence long term outcome in patients undergoing surgery for gastrointestinal cancer.

Colorectal Neoplasms↗
PubMed1993

Expression of interleukin-6 by intestinal enterocytes.

AIMS: To investigate the cellular source of the cytokine interleukin-6 (IL-6) in the small and large intestines of patients with inflammatory bowel disease, coeliac disease, and in controls. METHODS: IL-6 was detected in frozen sections of bowel by single and double label indirect immunofluorescence using rabbit polyclonal and murine monoclonal anti-IL-6 antibodies. The murine monoclonal antibodies RFDR1 (anti-MHC class II) and UCHT1 (anti-CD3) were used to localise macrophages and T lymphocytes, respectively. Lipopolysaccharide stimulated peripheral blood monocytes were used as positive control cells for IL-6 protein. RESULTS: IL-6 was demonstrated in the small and large intestine of patients with inflammatory bowel disease, coeliac disease, and in controls. The protein was present predominantly in enterocytes and colocytes in normal and inflamed mucosa, but not in the infiltrating inflammatory cells of the lamina propria. There were no discernable differences between patients with inflammatory bowel disease or coeliac disease and controls, nor between small and large bowel mucosa. Incubation of antibody with recombinant human IL-6 protein abolished the labelling. IL-6 protein was also present in lipopolysaccharide stimulated peripheral blood monocytes. CONCLUSIONS: The data suggest that enterocytes and colocytes may play an active part in the immune response of the gut. The presence of IL-6 in both inflamed and non-inflamed small and large intestine requires further investigation into the function of this cytokine in the gut.

Celiac Disease↗
PubMed1992

Intestinal intraepithelial lymphocytes and lymphoepithelial interactions in the human gastrointestinal mucosa.

Although representing a major immunological apparatus, it is not known how the immune system of the intestinal mucosa differentiates between dietary antigens (resulting in systemic tolerance) and potential pathogens. It is thought that intraepithelial T lymphocytes (IEL) may play a central role in local intestinal immunity and are likely to be important in immunity to gastrointestinal neoplasms and rejection responses to gut allografts. However, the biology of IEL and their unusual immunological microenvironments in the gastrointestinal mucosa are little understood. IEL are predominantly CD8+ TcR alpha beta+ CD3+ T cells which differ from lamina propria and peripheral T cells in many respects. IEL show low expression of CD5, CD6, LFA-1 (CD11a/CD18) and VLA-4, and high expression of HML-1. TcR gamma delta + IEL, although a minority population, are also phenotypically distinct, insofar as they are 50% CD8+, mainly V delta 1+ V gamma 9- and CD4- CD5-. IEL show poor proliferative responses to PHA, anti-CD3 and phorbol ester/calcium ionophore in vitro and have no clear functional role: they neither provide helper nor suppressor functions for Ig synthesis by B cells and do not mediate spontaneous cytotoxicity. However, there is evidence that IEL show preferential activation in response to sheep erythrocytes, presumably signalling via CD2. As normal and inflamed intestinal epithelia do not express ICAM-1, it seems unlikely that the LFA-1/ICAM-1 interaction is of importance to IEL activation. Rather, the CD2 (LFA-2) interaction with LFA-3 expressed by enterocytes may serve both to anchor IEL and to provide an accessory stimulus for activation. Nevertheless, the questions of antigenic specificity and immunological role remain unanswered.

Antigen-Presenting Cells↗
PubMed1992

Intracellular free Ca2+ fluxes and responses to phorbol ester in T lymphocytes from healthy elderly subjects.

A group of healthy elderly subjects (greater than or equal to 75 years) was selected by the strict criteria of the SENIEUR protocol, and compared with healthy young (less than or equal to 35 years) volunteers. Mitogenic responses of peripheral blood mononuclear cells to phytohaemagglutinin and anti-CD3 were significantly reduced in the elderly (P less than 0.0002), thereby confirming that even though in perfect health, elderly individuals show impaired cell-mediated immunity. However, no abnormality of intracellular free Ca2+ fluxes could be detected in purified T cells from the elderly subjects when stimulated with anti-CD3 antibody. Nevertheless, both the proliferative responses of purified T cells to phorbol ester and calcium ionophore (Ionomycin) and the phorbol ester-induced inhibition of the Ca2+ response were defective in the elderly subjects (P less than 0.003 and P less than 0.0002, respectively). These data suggest that signal transduction and the generation of second messengers proceed normally in T cells from the elderly, but downstream events mediated by activation of protein kinase C are dysfunctional.

Adult↗
PubMed1992

Impaired proliferative responses of peripheral blood B cells from splenectomized subjects to phorbol ester and ionophore.

The responses of peripheral blood B cells to mitogenic stimulation were examined in 12 splenectomized subjects without residual splenic function, as determined by pitted erythrocyte counts. These were compared to a group of healthy controls matched for age and sex. Polyclonal anti-immunoglobulin evoked a normal transient elevation in intracellular free Ca2+ in splenectomized subjects, thereby suggesting that the early events of the signal transduction pathway are not impaired. However, mitogenic stimulation by pre-treatment with phorbol ester and culture in presence of a calcium ionophore (Ionomycin) resulted in reduced uptake of 3H-thymidine and subsequent proliferation. Nevertheless, entry into the mitotic cycle, as assessed by expression of Ki67, was slightly, but not significantly impaired. Unlike in normal controls, where up to 7% of freshly-isolated B cells were Ki67+, almost no Ki67+ peripheral B cells were observed in splenectomized subjects. The data are consistent with the hypothesis that peripheral B cells in splenectomized subjects are in a reduced state of activation compared with normal controls and require additional growth factor stimulation before they can undergo mitosis.

Adolescent↗
PubMed1992

Murine intestinal humoral responses in chronic Schistosoma mansoni infections.

Specific and non-specific production of immunoglobulins (Ig) by the intestinal mucosa was examined in mice infected with the human blood fluke Schistosoma mansoni. Ileal and colonic mucosal tissue samples were cultured for 2 days, the medium replaced and the culture continued for a further 2 days. Ig concentrations and specific antibodies to soluble schistosome egg antigens in culture supernatants were estimated by isotype-specific ELISA. Cultured mucosae from control mice produced little IgG, but significant amounts of IgA and IgM on prolonged culture. IgG concentrations were increased in infected animals, mainly in the initial culture period, indicative of systemic, rather than local origins. By contrast, significantly increased local production of IgA and IgM occurred after the start of egg deposition in the intestinal mucosae. Although specific anti-egg antibodies of the IgG and IgM class were detected, none of the local IgA response was specific for schistosome eggs. We conclude that specific intestinal immune responses to schistosome eggs reflect systemic responses, whereas locally increased IgA production is largely non-specific. This pattern of response is likely to be related to the prior systemic exposure to schistosome eggs, which results in polyclonal local B-cell activation, but fails to trigger an antigen-specific IgA mucosal response.

Animals↗
PubMed1992

Specific circulating anti-gliadin IgG-class antibody does not mediate intestinal enteropathy in gliadin-fed mice.

The effects of specific circulating IgG antibody on the uptake of dietary antigen and in the generation of intestinal enteropathy have been investigated in Balb/c mice bred on a gluten-free diet. A monoclonal IgG1 antibody (GD3) was prepared against gliadin. After adoptive transfer into mice, this antibody was capable of mediating a type III hypersensitivity response in vivo to footpad challenge with gliadin. The titres of circulating GD3, as estimated in vitro by ELISA, correlated well with the degree of inflammation at sites of type III responses in vivo. Following footpad challenge with gliadin, titres of circulating GD3 antibody were reduced. GD3 antibody was tested for its ability to mediate inflammatory responses in vivo in the intestinal mucosa of mice fed with gliadin. Circulating GD3 antibody was removed selectively and specifically by dietary gliadin, compared to feeding with bovine serum albumin or maintenance on a gliadin-free diet only. However, we were unable to demonstrate any pathological changes in the intestine as a result of possible local antigen-antibody complex formation or deposition. Using radio-iodinated gliadin as a trace marker, no significant retention of gliadin in the intestinal mucosa was found in mice pre-injected with GD3 antibody. These data suggest that circulating IgG antibody has little effect on dietary antigen uptake in the gut, and alone is insufficient to mediate an enteropathy.

Animals↗
PubMed1992

Regulation of intestinal immunoglobulin production in response to dietary ovalbumin.

The effects of oral administration of ovalbumin (OVA) on intestinal immunoglobulin production was examined. Balb/c mice, bred and reared on an OVA-free diet, received either one dose or 14 consecutive daily intragastric doses of 25 mg OVA/dose. Single dose administration of OVA resulted in significant suppression of total immunoglobulins in the intestinal mucosa, particularly of the IgA isotype, although a very low titre anti-OVA IgG class antibody response was induced. After multiple peroral immunisations, there was more intestinal anti-OVA antibody induction and less suppression of total immunoglobulins. However, all the anti-OVA antibody was of the IgG isotype. In vitro production of mucosal immunoglobulins was not significantly reduced over 5 days, compared with controls, in either single or multiple administration groups, suggestive of a loss of T suppressor cell function in culture. Prior adoptive transfer of splenic and lymph node cells from mice preimmunised with OVA was capable of abrogating the local suppression of immunoglobulin production in vivo. Although adoptive transfer of bovine serum albumin-sensitised cells could also overcome some of the local suppression, complete restoration of normal immunoglobulin levels was not achieved. These data suggest that single oral administration of a novel dietary antigen induces a transient, non-specific suppression of intestinal immunoglobulin production, which can be overcome by antigen-specific T cells.

Administration, Oral↗
PubMed1992

Intracellular actin as a marker for myofibroblasts in vitro.

BACKGROUND: Myofibroblasts are found in a wide variety of normal tissues and pathological conditions. It is suggested that myofibroblasts are derived from normal fibroblasts and share with smooth muscle cells the expression of actin microfilament bundles. The aim of this study was to establish if the myofibroblast phenotype from tissue expander capsules and Dupuytren's nodules could be distinguished from normal dermal fibroblasts by quantitation of intracellular actin and the ratio of polymerized (filamentous) actin to nonpolymerized (globular) actin. EXPERIMENTAL DESIGN: Cell lines were established from six patients from each group. In addition to quantitation of intracellular actin, the cells were characterized by criteria of light microscopy, ultrastructure, actin immunofluorescence, and growth rates. RESULTS: Dermal fibroblasts were the smallest and the most spindle-shaped but grew rapidly and had few actin microfilament bundles. By contrast, myofibroblasts from expander capsules were larger and more stellate, proliferated slowly, and had the most prominent microfilament arrays. Cells from Dupuytren's nodules were intermediate in phenotype. Substantial and significant differences in intracellular actin contents were found, ranging from 0.69 +/- 0.05 micrograms/10(4) cells in fibroblasts and 0.77 +/- 0.15 micrograms/10(4) cells for Dupuytren's nodule cells to 1.46 +/- 0.44 micrograms/10(4) cells in expander capsule myofibroblasts (p < 0.05). Similar findings were found with respect to ratios of fibroblast to globular actins, being 0.22 for fibroblasts and 0.38 for Dupuytren's nodule cells compared with 0.70 for expander capsule myofibroblasts (p < 0.01). CONCLUSIONS: Measurement of intracellular actin contents and fibroblast:globular actin ratios offers a rapid, sensitive, and reliable technique for establishment of the myofibroblast phenotype and has considerable advantages over traditional ultrastructural approaches for the study of myofibroblast differentiation/regression and in vitro responses to experimental manipulation.

Actins↗
PubMed1991

Expression of leukocyte adhesion molecules by mucosal mononuclear phagocytes in inflammatory bowel disease.

Leukocyte adhesion molecules are important in cell-cell interactions of the immune system. Lymphocyte function-associated antigen 1 (cluster designation 11a) mediates interactions between T cells and mononuclear phagocytes through its ligand, the intercellular adhesion molecule 1 (CD54), whereas complement receptors 3 (CD 11b) and 4 (CD11c) are involved in complement-mediated phagocytosis. Expression of CD11 molecules and intercellular adhesion molecule 1 was studied in colonic biopsy specimens from 20 patients with inflammatory bowel disease and 10 normal controls. In normal colon, few mononuclear phagocytes expressed lymphocyte function-associated antigen 1 and intercellular adhesion molecule 1 at high densities. The major adhesion molecule was CD11c. Thus, the largest population of normal colonic mononuclear phagocytes was represented by quiescent, resident macrophages with likely phagocytic function. In inflammatory bowel disease, mononuclear phagocytes showed only a slight increase in CD11a expression and no significant change in expression of CD11b and CD11c. By contrast, the percentage of mononuclear phagocytes expressing intercellular adhesion molecule 1 was increased from 6.9% +/- 3.9% in controls to 69.2% +/- 12.8% in ulcerative colitis (P less than 0.001) and to 45.7% +/- 22.8% in Crohn's disease (P less than 0.01), showing a close relationship with histological activity. The increased expression of intercellular adhesion molecule 1 in inflammatory bowel disease indicates a state of immunological activation induced by local release of inflammatory cytokines. Such induction of intercellular adhesion molecule 1 on mononuclear phagocytes may be important in the maintenance of chronic inflammation by facilitating interactions with T cells and T-cell antigen recognition.

Adult↗
PubMed1991

Expression of the LFA-1 beta 2 integrin (CD11a/CD18) and ICAM-1 (CD54) in normal and coeliac small bowel mucosa.

The leucocyte adhesion molecules (beta 2 integrins) comprise CD11 alpha-chains and a common beta-chain (CD18). CD11a (leucocyte function-associated antigen 1, LFA-1) is expressed by most T cells, and is involved in antigen presentation by macrophages via its counter-receptor, intercellular adhesion molecule (ICAM-1, CD54). By criteria of double-label immunofluorescence of cryostat tissue sections, virtually all lamina propria T cells of the normal small bowel were found to express LFA-1 strongly. By contrast, only 30-60% of intra-epithelial lymphocytes (IEL) expressed detectable LFA-1, most of which were LFA-1 weak and CD18-. ICAM-1 was expressed strongly only by vascular endothelium. In coeliac disease, there was a modest increase of diffuse ICAM-1 expression in the lamina propria, mainly in the subepithelial zone, where ICAM-1+ macrophages were occasionally seen. There was also a slight overall increase in CD11a expression by IEL, seen predominantly in surface epithelium and mainly by the CD4+ minority subset, but not by CD4-CD8- (TcR gamma delta +) cells. These data suggest that the LFA-1/ICAM-1-dependent antigen presentation pathway is of minor importance to IEL in the normal small bowel, and does not assume a major role in coeliac disease.

Antigens, CD↗
PubMed1991

Gamma delta T cell receptor-positive cells of the human gastrointestinal mucosa: occurrence and V region gene expression in Heliobacter pylori-associated gastritis, coeliac disease and inflammatory bowel disease.

T cells expressing the gamma delta heterodimer of the T cell receptor (TCR) were studied with respect to their occurrence and expression of gamma delta TCR variable region (V) genes in the normal gastrointestinal mucosa and in a variety of inflammatory conditions. In controls, gamma delta TCR+ cells were a minority population confined to the epithelial compartment of stomach, small bowel and colonic mucosae. Unlike in the periphery, gastro-intestinal gamma delta TCR+ intraepithelial lymphocytes (IEL) were mainly V delta 1+ (89.98 +/- 17.70%); few were V delta 2+ (6.04 +/- 13.8%) or V gamma 9+ (11.38 +/- 10.73%). All gamma delta TCR+ IEL were CD5low; nearly half were CD8+ and the remainder were CD4-CD8- 'double negatives'. There was no significant change from normal in percentages of gamma delta TCR+ IEL in H. pylori-associated gastritis, Crohn's disease and ulcerative colitis. However, in coeliac disease, gamma delta TCR+ IEL were elevated from 2.54% (+/- 1.71) in controls to 29.6% (+/- 16.1) in untreated patients (P less than 0.001) and 18.5% (+/- 7.2) in treated patients (P less than 0.001) and more were CD4-CD8-. Otherwise, gamma delta TCR+ IEL phenotypes were little changed: the majority remained V delta 1+V delta 2-V gamma 9- and all were CD5low. These data suggest that increased gamma delta TCR+ IEL are not a generalized response to intestinal inflammation or to stress proteins, although the typical V delta 1+V delta 2-V gamma 9- CD5low phenotype is retained.

Adult↗
PubMed1990

The effect of zinc and vitamin C supplementation on the immune status of patients with Crohn's disease.

The immune status of 29 patients with Crohn's disease given oral supplements of Vitamin C, zinc or placebo for three-week periods was studied. Collectively, the patients showed T-cell hyporesponsiveness, as assessed by phytohaemagglutinin stimulation, which was significantly improved by Vitamin C. Both monocyte function, as assessed by latex phagocytosis, and pan T-Cell number were significantly reduced and were not influenced by supplementation. Humoral immunity, assessed by pokeweed mitogen-induced immunoglobulin synthesis, was normal and remained unchanged. Vitamin C supplements improved T-cell function in Crohn's disease, whereas neither Vitamin C nor zinc had a measurable effect on humoral immunity.

Journal Article↗