Search PubMed⌕ Search

Biomedical subjects

T Kouri

Publications and source records attributed to T Kouri.

34 records · Page 2Linked to original sources
PubMed1990

Occurrence of two germline-related rheumatoid factor idiotypes in rheumatoid arthritis and in non-rheumatoid seropositive individuals.

Human rheumatoid factor (RF) paraproteins express two distinct light chain cross-reactive idiotypes defined by the monoclonal antibodies 17.109 and 6B6.6. These germline gene-related cross-reactive idiotypes are both carried on VK3 light chains and are each present on about one-third of IgM RF paraproteins. We assessed the degree to which these idiotypes are represented in polyclonal RFs. We used rheumatoid arthritis (RA) and non-RA RF-positive sera selected from a large cross-sectional population study (the Mini-Finland Health Survey), and sera from a community-based follow-up study of recent-onset RA patients from Heinola, Finland. In the Mini-Finland Health Survey, elevated levels of the 17.109 RF idiotype were seen in sera of 13% of the RA and 19% of the non-RA group; 6B6.6 RF was seen in 26% of the RA and 28% of the non-RA group. In sera of the Heinola follow-up study, 17.109 RF was seen in 12% initially, but in only 3% at 8 years. Similarly, 6B6.6 RF was detected in 25% initially, but in only 7% at 8 years. Ten sera positive for RF prior to the onset of clinical RA were identified from individuals of a second large population study from Finland (North Karelia project); two of these sera exhibited the 6B6.6 idiotype; none exhibited the 17.109 idiotype. The data are consistent with the concept that these germline gene-related cross-reactive RF idiotypes occur frequently in the polyclonal RF of non-RA as well as RA sera, and that in RA the idiotypes may sometimes be reduced or lost as a consequence of somatic diversification of the RF through somatic mutation, usage of new germline genes, or both.

Arthritis, Rheumatoid↗
PubMed1990

Antibodies to synthetic peptides from Epstein-Barr nuclear antigen-1 in sera of patients with early rheumatoid arthritis and in preillness sera.

We studied IgG antibody levels to synthetic peptides (p62, E11 and E3) from Epstein-Barr nuclear antigen-1 (EBNA-1) protein sequence in sera of patients with rheumatoid arthritis (RA), in pre-RA and in rheumatoid factor (RF) positive non-RA sera from Finland. Anti-E11 and anti-E3 antibody levels were significantly elevated in RA sera, compared with both RF negative and RF positive nonrheumatoid controls. The concentrations of anti-E11 and anti-E3 antibodies in the preillness sera were lower than those in RA sera. Eight-year followup samples of patients with RA had slightly decreased levels of anti-E3 and anti-E11 antibodies compared with samples taken within 6 months of the disease onset. Anti-p62 antibody levels did not differ significantly between any of the groups studied. Thus, elevated levels of antibodies to 2 of the glycine containing EBNA-1 peptides were associated with clinical RA.

Adult↗
PubMed1989

DNA synthesis in prolyl 4-hydroxylase positive fibroblasts in situ in synovial tissue. An autoradiography-immunoperoxidase double labeling study.

DNA synthesis in prolyl 4-hydroxylase (PH; EC 1.14.11.2) positive fibroblasts in situ in synovial tissue was studied using an autoradiography-avidin-biotin-peroxidase complex (ABC) double labeling. Fibroblasts in monolayer culture and in situ in synovial tissue were PH positive, whereas freshly isolated peripheral blood lymphocytes, monocytes, dendritic cells and granulocytes were PH negative. In rheumatoid arthritis (RA) 37 +/- 3 (22-56)% of all DNA synthesizing cells in situ were PH containing fibroblasts, whereas all DNA synthesizing cells in patients with meniscus lesion were PH positive. In both conditions, more than half of the self-replicating fibroblasts were located in the lining cell layer. This is probably not an artifact caused by insufficient penetration of 3H-thymidine because most of the DNA synthesizing lymphocytes were deep down in the synovial stroma. In RA 51 +/- 8 (17-88) PH positive fibroblasts in the S phase of the cell cycle were observed/3 mm2 synovial tissue, whereas the corresponding figure in meniscus patients was only 1 +/- 1 (0-5) (p less than 0.01). This suggests that the local fibroblasts in RA are activated, probably as a result of various fibroblast growth factors produced locally as a result of the inflammatory synovitis. In RA however, less than 1% of all local fibroblasts were self-replicating in situ, whereas labeling indices over 5% were not uncommon in RA synovial fibroblast cultures. This finding suggests that uncontrolled fibroblast proliferation is regulated in vivo by negative feedback mechanisms.

Arthritis, Rheumatoid↗
PubMed1987

Activated T lymphocytes in patients with multiple sclerosis in clinical remission.

Activation state and proliferation of lymphocytes of 6 patients with definite multiple sclerosis in clinical remission were studied. Lymphocytes carrying MHC class II coded Ia antigen, glycoprotein gp 40/80 and interleukin-2 receptor were significantly higher in patients with MS in remission than in normal healthy controls. The entrance of T cells into the G1 and S phase of the cell cycle was studied using [3H]thymidine autoradiography in combination with immunocytochemistry (cell markers). The proportion of T cells in the S phase of the cell cycle in the peripheral blood was similar in the MS patient and in the control group.

Autoradiography↗
PubMed1987

Adherent cells from rheumatoid synovia: identity of HLA-DR positive stellate cells.

Rheumatoid synovia were enzymatically digested and the in vitro morphology of different types of plastic adherent cells was observed. Four main types of cells were found after 24 hours in culture: stellate cells which had nuclei resembling those of classical cultured fibroblasts, but which stained positively with I2 antibody (anti-HLA-DR antibody); fibroblastic cells; cells which resembled morphologically in vitro macrophages and which were I2 and OKM-1 positive; round monocytes. The stellate cells did not stain with anti-S-100 or OKT-6 antibodies, which are used to detect classical antigen presenting dendritic cells. Furthermore, in the presence of indomethacin the stellate shaped cells were replaced by new I2 positive cells with a typical fibroblast shape. These results support the view that the stellate cells in synovial cell cultures represent HLA-DR positive fibroblasts, probably B cells of synovial lining.

Arthritis, Rheumatoid↗
PubMed1985

Etiology of rheumatoid arthritis.

Definite genetic associations with immunological cooperative HLA-D(R) antigens have been demonstrated for rheumatoid arthritis (RA). Microbial etiology has not been proven, but some hope for the supporters of this view is still given by small viruses, plasmids of enteric bacteria or perhaps oncogen-like DNA-sequences. Yet, electrophoretical analysis of membrane proteins or surface glycoproteins of RA synovial cells does not show any differences compared to reference cells. Autoimmunity to several tissue elements has been demonstrated, but most of it is of secondary nature. Antigenicities of type II and III collagens are probably only contributory factors for HLA-DR4 positive individuals. Proteoglycans or minor cartilage collagens have not been extensively studied, so far. Endocrine, dietary or psychological influences might be triggering events for otherwise 'preloaded' individuals.

Animals↗
PubMed1984

Neurofibromatosis tumor and skin cells in culture. II. Structural proteins with special reference to the cytoskeletal and cell surface components.

Structural proteins of cultured neurofibromatosis (NF) tumor and skin cells were studied with reference to control skin fibroblasts. In polyacrylamide gel electrophoresis (PAGE)/fluorography the banding patterns of the cell lysates were markedly similar. NF tumor cells, however, produced a 60 kD band with a stronger and a 48 kD band with a lighter protein staining and metabolic labeling intensity. Furthermore, skin cells were also characterized by a 26 kD protein and the tumor cells by a 22 kD protein with high metabolic labeling intensity. Neuraminidase/galactose oxidase/NaB3H4-labeled NF skin and control skin cells possessed a 220 kD protein that was less intensively labeled in the tumor cells. The banding pattern of the skin cells was also characterized by a protein with slightly lower molecular weight (86 kD) than that of the tumor cell lysates (90 kD). In all cell lines studied indirect immunofluorescence stainings revealed bright arrays of vimentin type intermediary filaments but no desmin, cytokeratin, glial fibrillary acidic protein (GFAP), or neurofilament proteins. NF skin and control skin cells possessed well developed actin-containing bundles of microfilaments, while those of the tumor cells lacked a typical stress-fiber organization. The general morphology of the tumor cell cultures was also irregular. Transmission electron microscopy revealed no basic differences in the structure of intermediary filaments or microfilaments. The present data provide basic knowledge of neurofibromatosis skin and tumor cells and demonstrate that cultured cells originating from neurofibromas are defective in both their intracellular and extracellular organization.

Actins↗
PubMed1984

Antigenicity of proteins from cultured synovial fibroblasts.

We were able to characterize about 25 antigenic proteins of cultured synovial fibroblasts with apparent molecular weights of 15-230 kd by SDS-electrophoresis and immunoblotting using guinea pig antiserum. Some of these proteins were bovine-serum-derived, adsorbed onto fibroblasts from culture medium. Both rheumatoid and normal sera contained natural antibodies reacting with synovial fibroblast as well as bovine serum antigens when studied with immunoblotting. The amounts of antibodies were quantitated with enzyme immunoassay, measuring IgG and IgA class antibodies against plasma membrane preparations of rheumatoid and normal synovial fibroblasts. No rheumatoid arthritis-related changes were detected in synovial fibroblast protein antigens or antibodies against them in rheumatoid patient specimens.

Antibodies↗
PubMed1984

Surface membrane glycoproteins of macrophage-like synovial cells from rheumatoid and control patients.

Synovial cells were prepared by enzyme digestion and Percoll gradient centrifugation of rheumatoid arthritis (RA) synovial specimens or by trypsin-rinsing of non-inflammatory cadaver joints. Most (70-80%) of the cells from RA patients were OKIa -positive macrophage-like cells, 10-20% other OKIa -positive cells, and about 10% fibroblastic cells, whereas 90% of the normal synovial cells were OKIa -positive macrophage-like cells and the rest fibroblasts. These adherent synovial cells were compared with fibroblastic synovial cells obtained by sequential passaging of explanted dividing cells. Periodate-[3H]borohydride labelling followed by SDS-gradient gel electrophoresis demonstrated similar sialo-glycoprotein patterns in both the adherent synovial cells and synovial fibroblasts. The molecular weights of the main surface glycoproteins resembled closely those of skin fibroblasts but not those of peripheral blood monocytes. RA samples showed inconsistent heterogeneity. The results indicate either that all synovial cells possess a similar basic structure or that macrophages of peripheral blood origin express fibroblastic contact glycoproteins when settling down into synovium.

Arthritis, Rheumatoid↗
PubMed1984

Morphologic alterations in cultured human synovial fibroblasts induced by blood mononuclear cells.

Effects of peripheral blood mononuclear cells on cultured synovial fibroblasts were studied. When mononuclear cells from normal or rheumatoid blood were incubated on synovial fibroblast cultures, a part of the cells adhered to the fibroblasts. They were mainly T lymphocytes but also some B lymphocytes and monocytes. After a 10-hour incubation, adhered mononuclear cells induced morphologic alterations to synovial fibroblasts: appearance of stellate cells and thinning and branching of fibroblasts. No changes were seen when the cells were incubated in the presence of indomethacin. Cytotoxicity of peripheral blood mononuclear cells from 8 rheumatoid patients was also tested against three rheumatoid and three normal synovial fibroblast strains. Only 2 out of 48 combinations were cytotoxicity. The potentially cytotoxic mononuclear cells were bound equally well to rheumatoid and control synovial fibroblast cultures.

Arthritis, Rheumatoid↗
PubMed1984

Characterization of plasma membranes and rough endoplasmic reticulum of synovial cells cultured from rheumatoid arthritis patients.

[35S]methionine-labelled plasma membrane (PM) and rough endoplasmic reticulum (RER) proteins were analysed from synovial cell cultures derived from rheumatoid arthritis (RA) and reference patients. Pure RER was prepared by a modification of CsCl-containing sucrose-cushion method. The PM proteins were resolved into 30-35 bands using sodium dodecyl sulphate-electrophoresis in polyacrylamide gradient gels. The major polypeptides had apparent molecular masses of 170, 140, 110, 60, 40, 33, 23 and 14 kilodaltons. The major RER polypeptides had the apparent molecular masses of 170, 74, 58 and 35 kD. No reproducible differences were demonstrated in the polypeptide patterns or in the specific activities of the PM and ER (endoplasmic reticulum) marker enzymes between cells from RA and reference patients. The results reflect similarities of membrane structures in RA and reference cells, although differences have been reported in their metabolism.

Arthritis, Rheumatoid↗
PubMed1983

Plasma membrane glycoproteins of cultured rheumatoid synovial fibroblasts.

Fibroblast cultures were started from synovial tissue samples of 12 rheumatoid arthritic, 9 non-rheumatoid synovitic and 6 control patients. External galactose units of plasma membrane glycoproteins of confluent cells were labelled using the galactose oxidase-tritiated borohydride method. These surface-labelled cells were analyzed for possible differences in their glycoproteins by electrophoresis in SDS-containing polyacrylamide gradient gels. Total cell lysates were separated into 50-60 polypeptide bands. Fluorography of the gels revealed about 20 labelled plasma membrane glycoproteins. Some strain-specific differences were detected between the samples in all the groups, but no correlation with rheumatoid arthritis could be demonstrated.

Arthritis, Rheumatoid↗
PubMed1983

Effect of Mycoplasma pulmonis infection on protein and glycosaminoglycan synthesis of cultured connective tissue cells.

Human synovial cells, fetal skin fibroblasts and rat granulation tissue fibroblasts were experimentally infected with Mycoplasma pulmonis, a species identified as a contamination of cell cultures, and studied for collagen, total protein and glycosaminoglycan synthesis. Hyaluronic acid and sulfated glycosaminoglycan synthesis were stimulated in cultures where the infection reduced cell density, while they were retarded in cultures which had proliferated into higher density than the controls. An extra polypeptide with molecular weight of 20 kD was seen in [35S]methionine-labelled cells. Media of rat granulation tissue cells showed a shift of a 39-42 kD polypeptide to 33-36 kD position in [35S]methionine and [3H]proline labellings. Other minor changes were also noticed. Collagen synthesis or procollagen conversion to collagen were, however, not altered.

Animals↗
PubMed1983

Lentil lectin-bound glycoproteins of cultured rheumatoid synovial cells.

Synovial cell lines were cultured from 5 rheumatoid arthritis (RA) patients, from 4 patients with other synovial inflammation and from 4 non-inflammatory controls. Protein synthesis was studied by [35S]methionine labelling. Glycoproteins containing D-glucose or D-mannose were separated by affinity chromatography with immobilized lentil lectin and analysed by SDS-electrophoresis in polyacrylamide gradient gels (SDS-gradient PAGE). About 12% of labelled protein was bound to the lectin column (range 7.9-20.0%). Proteins of RA cells showed no differences in binding compared with proteins of the reference cells. At least 40 glycoproteins were separated by SDS-gradient PAGE. No new or missing bands were observed in RA cells, but several quantitative changes and microheterogeneity of some polypeptide molecular weights were noted.

Adult↗