Search PubMed⌕ Search

Biomedical subjects

A Ihan

Publications and source records attributed to A Ihan.

25 records · Page 2Linked to original sources
PubMed1997

Flow cytometric analysis of lymphocytes in cerebrospinal fluid in patients with tick-borne encephalitis.

INTRODUCTION: Cerebrospinal fluid (CSF) lymphocyte subsets were examined by flow cytometry in 33 patients with tick-borne encephalitis (TBE) in order to determine their values. PATIENTS AND METHODS: Lymphocytes were isolated from CSF and lymphocyte subsets were determined: lymphocytes T (CD3+), lymphocytes B (CD19+), NK cells (CD3-CD56+), helper T cells (CD3+CD4+) and cytotoxic T cells (CD3+CD8+). The expression of IL-2 receptors (CD25+) and transferrin receptors (CD71+) on T cells and HLA-DR molecules on T cell subsets was examined. Furthermore, possible relationships among different TBE patient population variables (gender, age, severity of disease, duration of meningitis) were considered. RESULTS: The analyses of the CSF lymphocyte population subsets are presented. Lymphocytes T (CD3+) were significantly higher in the CSF than in the peripheral blood as was the case with the T cells that expressed transferrin receptors (CD71). Lymphocytes B (CD19+) and NK cells (CD3-CD56+) prevailed in the peripheral blood. In the early course of the disease, a higher expression of HLA-DR molecules on T lymphocytes was observed, while later a higher expression of IL-2 receptors (CD25+) was observed. DISCUSSION: Significant differences in lymphocyte subsets between the CSF and the peripheral blood were found. Significant time-dependent changes of CSF lymphocyte subsets during course of infection were observed. The results of the present study give us deeper insight into CNS cellular immunopathogenic mechanisms in patients with TBE.

Adult↗
PubMed1997

Flow cytometric analysis of lymphocytes isolated from nasal polyps.

We analyzed by flow cytometry the expression of IL-2 receptors (alpha subunit-CD25) and ICAM-1 adhesion molecules (CD54) on T cells and subsets (CD4, CD8) isolated from nasal polyp tissue in allergic and non-allergic patients. We found a significant increase in IL-2 receptor and ICAM-1 molecule expression on T cells isolated from nasal polyp tissue compared to peripheral blood lymphocytes. We also found a significantly increased expression of ICAM-1 molecules on CD8+ cells in non-allergic compared to allergic patients. The latter may reflect a difference in cytotoxic immune response between allergic and non-allergic patients, but the result should be confirmed in a more extensive study including cytokine and immunoglobulin analysis. We hope that it would enable us to obtain a deeper insight into the local immune events and further to clarify the etiology and pathogenesis of nasal polyps and their relation to allergy.

Aged↗
PubMed1995

HLA-DR expression on CD8 lymphocytes from gastric mucosa in urease-positive and urease-negative gastritis.

We isolated lymphocytes from chronically inflamed gastric mucosa. We analysed the expression of IL-2 receptors (CD25), transferin receptors (CD71) and HLA-DR molecules on T lymphocytes by flow cytometric analysis in 16 patients with urease-positive and in 7 patients with urease-negative chronic gastritis. In G0, G1 and G2 histological type (Sydney classification) of gastritis the number of lymphocytes obtained from the gastric mucosa biopsies was too low for the flow cytometric analysis. However, in G3 histological type of chronic gastritis we obtained enough cells for the flow cytometric analysis in 75%. We demonstrated a significant increase in HLA-DR expression on CD8 cells from patients with urease-positive gastritis compared to urease-negative gastritis. We also observed a statistically non-significant increase in HLA-DR expression on CD3 cells, and in CD71 expression on both CD3 and CD8 cells in urease-positive gastritis. However, no difference in CD25 expression was found between the two types of gastritis.

CD3 Complex↗
PubMed1993

Apyrogenic synthetic desmuramyldipeptide, LK-409, with immunomodulatory properties.

The synthesis and some immunological characteristics of a new desmuramyl dipeptide 7-oxooctanoyl-L-alanyl-D-isoglutamine (LK-409) are presented. The effects of this compound were compared with those of N-acetylmuramyl-L-alanyl-D-isoglutamine (MDP). The influence of LK-409 on the number of B and T cells in spleen and the number of peritoneal macrophages was studied; Jerne's plaque forming cells assay was performed to monitor the effect of B cell differentiation. The blast transformation of T cells stimulated with concanavalin A was used to detect the influences on T lymphocytes. The activation of macrophages was studied as well. In contrast to MDP, LK-409 was apyrogenic in the doses applied but had similar immunomodulatory properties. Tested immunological properties and the absence of pyrogenicity and low toxicity make LK-409 a candidate for an immunomodulatory drug and a model molecule suitable for studying and understanding the dual activity of the MDP and its analogues.

Acetylmuramyl-Alanyl-Isoglutamine↗
PubMedDate not supplied

Diminished interferon-gamma production in gastric mucosa T lymphocytes after H. pylori eradication in duodenal ulcer patients.

BACKGROUND/AIMS: Helicobacter pylori (H. pylori) infects an estimated 50% of the world population; however, only a small proportion of individuals develop clinical symptoms of gastritis, peptic ulceration or gastric cancer. The variations in disease presentation may be due to differences in bacterial virulence and/or immune response to the pathogen. In a previous study we reported an increased expression of the IL-2 receptor in duodenal ulcer (DU) patients. The present study examines the expression of IL-2 receptor and intracellular lymphokine production in gastric mucosa infiltrating T lymphocytes in DU patients before and after H. pylori eradication. METHODOLOGY: T lymphocytes were isolated from gastric mucosa biopsies by using mechanical and enzymatic tissue desegregation. Ficoll-purified lymphocytes were incubated with monoclonal antibodies and analyzed by using 4-color flow cytometry analysis for the IL-2 receptor (CD25) and intracellular interferon-gamma (IFN-gamma) and IL-4 expression. Lymphocytes from 24 H. pylori-infected patients with severe gastric mucosa infiltration (G2 and G3 histological type in Sydney classification) were analyzed. RESULTS: We demonstrated a significant decrease in IL-2 receptor expression on gastric mucosa T cells 3 and 12 months after eradication of H. pylori. We also demonstrated a diminished IFN-gamma production 3 and 12 months after H. pylori eradication. CONCLUSIONS: Our results suggest that cellular immune activation in gastric mucosa is reversibly dependent on the presence of H. pylori.

Amoxicillin↗
PubMedDate not supplied

Il-2 receptor expression on gastric mucosa T lymphocytes is enhanced in duodenal ulcer patients compared with non-ulcer dyspeptic patients.

BACKGROUND/AIMS: Helicobacter pylori infects an estimated 50% of the world population, however only a small proportion of individuals develop clinical symptoms of gastritis, peptic ulceration or gastric cancer. The variations in disease presentation may be due to differences in bacterial virulence and/or immune response to the pathogen. This study examined the expression of IL-2 receptor and ICAM-1 molecules on gastric mucosa infiltrating T lymphocytes in two groups of H. pylori infected patients: one group with an active ulcer disease and the other with non-ulcerative chronic gastritis. MATERIAL AND METHODS: T lymphocytes were isolated from gastric mucosa biopsies by using mechanical and enzymatic tissue desegregation. Ficoll-purified lymphocytes were incubated with monoclonal antibodies and analyzed by using 3-color flow cytometry analysis for the IL-2 receptor (CD25) and ICAM-1 molecule (CD54) expression. Lymphocytes from 37 Helicobacter pylori infected patients with severe gastric mucosa infiltration (G2 and G3 histological type in Sydney classification) were analyzed; 18 patients had at least 5-year history of duodenal ulcer disease (group A) and 19 patients had at least 3-year history of non-ulcer dyspeptic disease (group B). RESULTS: We demonstrated a significant increase in IL-2 receptor expression on gastric mucosa T cells in ulcer patients (group A) compared with non-ulcer dyspeptic patients (group B). However, no difference in CD54 expression was found between the two groups of patients. CONCLUSIONS: Our results suggest the importance of the local immune response in the development of H. pylori related diseases. Also some interesting points for further study of the association between immune response against H. pylori and the development of duodenal ulcer disease were indicated.

Adult↗