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Biomedical subjects

A Górski

Publications and source records attributed to A Górski.

At least 19 recordsLinked to original sources
PubMed1999

Adhesion molecule expression stimulated by Bacteroides thetaiotaomicron cell-surface antigens.

Bacteroides thetaiotaomicron, a Gram-negative anaerobic rod belonging to the Bacteroides fragilis group (BFG), is involved in many systemic and local, most frequently suppurative infections in man. The cell envelope of these rods is composed of two carbohydrate-containing antigens: lipopolysaccharide (LPS) and capsular polysaccharide (CPS). Adhesion molecules ICAM-1, VCAM-1 and E-selectin (ELAM-1) are induced on the endothelial cells by mediators of inflammation. The aim of this study was to assay the ability of B. thetaiotaomicron surface antigens to induce adhesion molecule expression on the endothelial cells. The influence of LPS and CPS on the expression of adhesion molecules on HMEC-1 cell line was examined in an ELISA test. ELISA was performed with monoclonal mouse anti-human: ICAM-1, VCAM-1 and E-selectin antibodies of the IgG class. B. thetaiotaomicron lipopolysaccharides revealed the ability to induce ICAM-1, VCAM-1 and E-selectin expression on the endothelial cells. Their activities were similar, but lower than the activity of Eschericha coli LPS. ICAM-1 was the most stimulated adhesion molecule. The strongest activation by LPS was achieved at the concentrations of 10.0 and 1.0 micrograms/ml. The ability of capsular polysaccharide to induce the expression of adhesion molecules was considerably weaker.

Animals↗
PubMed1998

T-cell interactions with extracellular matrix proteins in periodontal disease.

Lymphoid cell infiltration of periodontal tissues undergoing pathological destruction suggests a functional interdependence between connective tissue proteins such as collagen, fibronectin and elastin and mononuclear cells, mainly T lymphocytes. The aim of the study was to assess T lymphocyte proliferation after stimulation by mAb OKT3 and then costimulation by ECM (extracellular matrix) proteins, as well as T-cell adhesion to connective tissue proteins in patients with adult periodontitis, early-onset periodontitis, chronic gingivitis and experimental gingivitis. Controls included patients with clinically healthy periodontium. Statistical analysis of results showed a significantly decreased level of T lymphocyte proliferation in response to costimulating action of ECM proteins among patients with adult periodontitis as compared to the control group. Reactivity of T-cells was much higher in experimental gingivitis than in adult periodontitis, and significantly lower in chronic gingivitis than in controls. In addition, T-cell interaction with ECM proteins was abnormal in early-onset periodontitis patients, but was not statistically significant.

Adult↗
PubMed1998

T cell adhesion to the extracellular matrix proteins as a determinant of pregnancy success or failure.

Recent studies emphasize an important role of the extracellular matrix (ECM) proteins in the regulation of T cell function. The role of the T cell:ECM interaction during pregnancy has not been established yet. ECM proteins promote acquisition of the adhesive and degradive properties required by the embryo for successful implantation. T cells presented at the maternal-foetal interface may regulate the maternal immune response to the foetal allograft. T cell adhesion to collagen IV (C-IV), elastin (E) and fibronectin in 35 women with threatened abortion and in five normal pregnant women were studied. The relationship between T cell adhesion to ECM and pregnancy outcome was analyzed. Correlation between T cell adhesion to fibronectin and C-IV and pregnancy success or failure were observed. Our studies indicate that there is enhanced T cell adhesion to C-IV and fibronectin in women with unexplained threatened abortion, especially in those with a previous history of recurrent spontaneous abortion (RSA).

Abortion, Threatened↗
PubMed1998

Increased expression of adhesion molecule CD18 (LFA-1beta) on the leukocytes of peripheral blood in patients with acute ischemic stroke.

OBJECTIVES: The aim of this study was to investigate whether adhesion molecules play a role in acute ischemic stroke. MATERIAL AND METHODS: Using immunofluorescence phenotyping and flow cytometry, the expression of leukocyte adhesion molecules CD54, CD11a, CD11b and CD18 in peripheral blood were measured within 12 h after onset of ischemia in 20 patients with stroke. Follow-up measurements were performed at 7 and 30 days after ictus. RESULTS: CD18 immunofluorescence was significantly increased on the leukocytes within 12 h after onset in patients with stroke compared with the age-matched control group (20 patients with other neurological diseases). Follow-up measurement of CD18 revealed normal results as found in the control group. CONCLUSION: Our data support the idea that adhesion molecules are involved in tissue injury in ischemic stroke.

Aged↗
PubMed1998

Apoptosis of T cells in the first trimester human decidua.

PROBLEM: Apoptosis has been accepted as a mechanism for maintaining tolerance in the immune system. The induction of apoptotic cell death can also be a possible outcome of the lymphocyte activation. Expression of Fas ligand (FasL) by the human trophoblast has been proposed as a mechanism providing protection against the lytic action of decidual immune cells. The aim of this study was to determine whether decidual T cells undergo apoptosis during abortion. METHOD OF STUDY: We studied apoptosis of T cells isolated from the first-trimester decidua in 12 women after spontaneous or elective abortion. We used gel electrophoresis to detect DNA fragmentation. Cells undergoing DNA fragmentation also were identified by DNA analysis using flow cytometry. This method was based on the accumulation of ethanol-fixed apoptotic cells in the sub-G0/G1 peak of the DNA content as a result of the loss of DNA fragments from the cells and because of a reduced DNA ability to be stained by propidium iodide. In addition, the expression of Fas antigen on the surface of decidual T cells (CD3+) also was determined. RESULTS: We did not detect apoptosis by the "ladder" technique. However, the apoptotic index (the percentage of positive cells per total number of cells) ranged from 2% to 24% using flow cytometry. CONCLUSIONS: Trophoblast cells usually fail to stimulate alloantigen-specific T cells, but they may express nonclassical major histocompatibility complex alloantigens to which mothers can produce immunoglobulin G alloantibody, which requires T helper cell activation. The apoptosis of T cells in the human decidua, probably through Fas-FasL signaling, may be a defense mechanism against rejection of the fetal allograft by the maternal immune system.

Abortion, Spontaneous↗
PubMed1998

[The evaluation of expression of T-lymphocytes and NK cell surface receptors in women with threatened miscarriage].

OBJECTIVES: Recent studies emphasise an important role of immunological mechanisms in pregnancy maintenance. Therefore, unravelling mechanisms regulating placentogenesis are critical to understanding the pathogenesis of recurrent spontaneous abortion. MATERIALS AND METHODS: We studied 49 women with threatened abortion and 24 healthy pregnant women. In addition, we studied 17 women with the history of recurrent spontaneous abortion and 10 healthy nonpregnant women in reproductive age with the previous successful pregnancy outcome. CD3, CD45 RO, CD4, CD8, CD16 expression on peripheral blood lymphocytes were studied using flow cytometry. RESULTS: We determined that there is significantly higher CD4 expression in pregnant recurrent aborters compared to control (p < 0.05). Pregnant recurrent spontaneous aborters, with the successful pregnancy outcome have significantly lower CD16 expression compared to those, who abort (p < 0.05). CONCLUSION: Our studies may indicate that T cell and NK cell can be involved in the pathogenesis of pregnancy loss.

Abortion, Threatened↗
PubMed1998

Lymphocyte interactions with extracellular matrix proteins and endothelium in renal allograft recipients.

Recent data indicate that extracellular matrix (ECM) proteins can provide costimulatory signals during the process of T cell activation. Those proteins accumulate in situ during allograft rejection; therefore, it may be expected that local ECM: T cell interactions may be relevant in the immunopathology of rejection. T cell adhesion from allograft of recipients with stable renal function (RAR-S) and patients with biopsy-proven chronic rejection (RAR-CH) to ECM proteins (collagen type IV, fibronectin, elastin) was measured. Furthermore, T cell: endothelial interactions in vitro were studied. Adhesion of PHA-activated T cells from both groups of allograft recipients to fibronectin, collagen type IV and elastin was significantly lower than in healthy blood donors. Moreover, similar pattern of activity was observed when T cell attachment to resting and activated endothelium was studied. There were no significant differences in the number of circulating CD45RO and CD4 positive T cells. We observed a higher (although not significantly) adhesion of the T cells to resting human dermal microvascular endothelial cells (HMEC) in the chronic stages of rejection, which can suggest that the immunosuppressive protocol used in the treatment of chronic rejection is insufficient to control immunopathologic phenomena occurring in that process. Therefore, it may be argued that too low immunosuppression can be one of the factors responsible for the development of this complication.

Cell Adhesion↗
PubMed1997

Role of extracellular matrix proteins in organ transplantation.

Recent data indicate that the extracellular matrix (ECM) proteins can regulate the process of T cell activation. Lymphocytes express an array of surface integrin and non-integrin receptors (adhesion molecules) mediating those phenomena. Since ECM proteins accumulate in situ during allograft rejection, it is likely that such T cell: ECM interactions are relevant in the immunopathology of rejection. Adhesion molecules are also thought to affect the very early events between host leukocytes and vascular endothelium. Therefore, immunomodulation of T cell interactions with the ECM proteins and endothelium may lead to the development of novel therapeutic strategies in clinical organ transplantation.

Animals↗
PubMed1997

HIV-protein-mediated alterations in T cell interactions with the extracellular matrix proteins and endothelium.

Recent data point to the immunoregulatory role of extracellular matrix (ECM) proteins in the process of T cell activation. We studied the effects of HIV proteins on those interactions as well as on endothelial adhesion molecule expression. Gp 120 and gp 41 inhibited CD3-triggered T cell co-stimulation by the ECM proteins, while Nef was stimulatory. T cell adhesion to the ECM proteins was affected in a similar fashion. Furthermore, tat induced E-selectin (but not VCAM-1 and ICAM-1) endothelial expression. Those findings may be relevant for the understanding of immunopathology of AIDS.

Cell Adhesion↗
PubMed1996

Gamma delta + T cells in Wilson's disease.

Little is currently known about the role of gamma delta + T cells in disease pathogenesis. We have demonstrated elevated levels of gamma delta + T cells in the peripheral blood and cerebrospinal fluid of patients with Wilson's disease compared with other neurological diseases. The percentage of V delta 1 +/ gamma delta + T cells was between 20% and 50% in all patient groups; gamma delta + T cells in blood correlated with copper concentrations. The antigen reactivity of gamma delta + T cells and how the antigens relate to the gamma delta + T cells found in WD remains unknown. It remains unclear whether there is a direct reason for the elevated gamma delta + T cells population found in WD. Immunohistochemistry of frozen autopsy material from brain and liver of WD patients could allow exact localization of gamma delta + T cells and heat shock proteins in future studies.

Adult↗