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Biomedical subjects

R Matre

Publications and source records attributed to R Matre.

At least 145 records · Page 8Linked to original sources
PubMed1984

In situ characterization of cell infiltrates in human dental periapical granulomas. 2. Demonstration of receptors for the complement components C3b and C3d.

The inflammatory cell infiltrates in human dental periapical granulomas were studied through the demonstration of receptors (R) for fragments C3b and C3d of the complement component C3, C3bR and C3dR were detected in cryostat sections by the closed chamber hemadsorption technique. Sheep erythrocytes sensitized with rabbit IgM antibody and coated with human C3B or C3d were used as indicator cells. Of the 62 granulomas studied, 23 showed strong or moderate C3bR activity, and weak C3dR activity was detected in 5 out of 25 specimens. The C3bR activity was abolished by treatment with 0.25 mM periodic acid, indicating that carbohydrate is a part of the C3bR. Using an antiserum to C3R as first layer in indirect immunofluorescence experiments, the C3R was localized to cell membranes. The low C3dR activity indicates that a minor part of the mononuclear cells in the human periapical granulomas were B lymphocytes.

Adult↗
PubMed1984

In situ characterization of cell infiltrates in human dental periapical granulomas. 3. Demonstration of T lymphocytes.

Cryostat sections of 66 snap-frozen dental periapical granulomas were examined for T lymphocytes by the closed chamber hemadsorption technique using sheep erythrocytes (E) treated with 2-aminoethylisothiouronium bromide hydrobromide (AET) as indicator cells (AET-E). T lymphocytes were also demonstrated by immunofluorescent staining using a rabbit anti-T lymphocyte antiserum. Eighty-six % of the granulomas showed adherence of AET-E, and often a focal AET-E adherence pattern was seen, indicating a localized infiltration of T lymphocytes. Diffuse, moderate binding of AET-E to sections of some granulomas may be due to recirculating T lymphocytes traversing the tissue. The results of the immunofluorescence test parallelled the results obtained in the hemadsorption test. The results show that mononuclear cell infiltrates of periapical dental granulomas usually contain T lymphocytes. Although their pathogenetic function in dental periapical granulomas is still not known, infiltrates of T lymphocytes indicate that cellular immune reactions are involved.

Adult↗
PubMed1984

In situ characterization of the foam cells in early human atherosclerotic lesions.

Erythrocytes (E) sensitized with IgG antibodies bound to the fatty streaks in cryostat sections of early human atherosclerotic lesions. E sensitized with IgA or IgM antibodies of F(ab') 2 fragments of IgG did not bind. The binding was inhibited by intact IgG and by Fc fragments but not by F (ab')2 fragments or by albumin, indicating the presence of receptors for the Fc part of IgG (FcR). E sensitized with IgM antibodies and human complement did not bind. The FcR were also studied using soluble immune complexes of horseradish peroxidase (HRP) and rabbit IgG antibodies to HRP. The peroxidase activity was detected histochemically. The bound complexes were localized to most of the lipid cells (foam cells) in the lesions. The cytoplasm of the FcR positive foam cells stained diffusely for acid alpha- naphthyl acetate esterase. Most of the foam cells were stained with monoclonal antibodies against HLA-DR antigens. The data indicate that most foam cells in early atherosclerotic lesions are derived from monocytes.

Adult↗
PubMed1984

A monoclonal antibody inhibiting human placental Fc gamma-receptor activity.

Fc gamma receptor (FcR) from human placenta was solubilized using EDTA and 2-mercaptoethanol and purified by affinity chromatography on human IgG-coated Sepharose 4B. BALB/C mice were immunized with FcR and monoclonal antibodies were obtained by growing hybridoma cells following fusion of spleen cells with P3 X 63Ag8 myeloma cells. Using an immunofluorescence technique, the IgG1 monoclonal antibody secreted by clone B1D6 stained the FcR-positive areas in sections of placental tissue. The endothelium of the foetal stem vessels stained more strongly than did the trophoblasts. The antibody also inhibited the haemadsorption to placental tissue of erythrocytes (E) sensitized with IgG antibodies (A), (EA), and inhibited the agglutination of EA by FcR. The data indicate that the monoclonal antibody reacts with the placental FcR at the binding site for IgG, or with an epitope close to the binding site. Apparently, the FcR in different anatomical areas in the placenta have a common antigenic determinant.

Antibodies, Monoclonal↗
PubMed1984

Myasthenia gravis: difference between thymoma-associated antibodies and cross-striational skeletal muscle antibodies.

Serum from 20 of 137 patients (15%) with myasthenia gravis (MG) contained antibodies to a citric acid extract (CAE) of skeletal muscle. A thymoma was found in all 19 of these patients who were thymectomized. There was no evidence of thymoma in patients who did not have CAE antibodies. Serum from 40 of the same 137 patients (30%) contained antibodies that gave a cross-striational immunofluorescent pattern in skeletal muscle. This pattern was seen with serum from 16 of the 20 thymoma patients, but also with serum from 24 patients without thymoma. The cross-striation antibodies were not absorbed by CAE coated on to tanned sheep erythrocytes. Accordingly, antibodies detected in the two tests have different specificities.

Antibodies↗
PubMed1984

Plasma exchange in patients with Guillain-Barré syndrome: clinical improvement in patients with serum IgG antibodies to peripheral nerve tissue.

The mixed hemagglutination technique was used to demonstrate IgG antibodies to peripheral nerve tissue in sera from patients with Guillain-Barré syndrome. The clinical effect and the effect on the antibodies of plasma exchange (PE) were examined in 24 patients, 16 patients with acute form and 8 patients with the chronic form of the disease. Neurological examination with muscle testing and neurophysiological examination of the patients were performed before and immediately after the PE. Before PE antibodies were detected in sera from 15 of the patients. These patients showed clinical improvement during the treatment, however in one of the patients only after a time interval of 2 weeks. After PE, antibodies were detected in sera from only 3 of the patients. The 9 patients without detectable antibodies showed no clinical improvement.

Adolescent↗
PubMed1983

Ultrastructural demonstration of Fc gamma-receptors in sarcoid skin lesions.

Immune complexes of horseradish peroxidase oxidase (HRP) and rabbit IgG antibodies to HRP were used to study the Fc gamma-receptors in granulomas of cutaneous sarcoidosis. Cryostat sections of skin biopsies were incubated with HRP-anti-HRP, and the peroxidase activity was demonstrated with 3,3-diaminobenzidine tetrahydrochloride and H2O2. Most cells in the granulomas, both epithelioid and giant cells, were stained. By electron microscopy, the reaction products were localized to the plasma membranes of the cells as well-defined granular deposits. No reaction product was demonstrated intra- or extracellularly.

Granuloma↗
PubMed1983

Myasthenia gravis. Antibodies to skeletal muscle cell surface antigens.

Sera from 28 of 137 patients with myasthenia gravis (MG) (i.e. 20%) contained antibodies which stained the surface of skeletal muscle cells in an indirect immunofluorescence test. Forty of the 137 sera (i.e. 30%) contained cross-striational antibodies. Absorption experiments showed that the antibodies staining the muscle cell surface were different from those staining the cross-striational bands. Twenty of the sera (i.e. 15%) contained antibodies which agglutinated sheep erythrocytes (SE) coated with a citric acid extract of skeletal muscle (CAE). These antibodies were closely associated with the presence of a thymoma. There was a positive correlation between the antibodies agglutinating CAE-coated SE and those staining the muscle cell surface. Absorption experiments indicated that the antibodies to CAE were directed against muscular antigens located in or near the sarcolemma.

Antibodies↗
PubMed1983

Stage-related correlations between immunoglobulins and complement components in preoperative sera from patients with gastric carcinoma.

Immunoglobulins A, G and M and complement components C3, C4 and C1-INH were quantitated in sera taken preoperatively from 168 patients with gastric carcinoma. The values were grouped according to stages (pTNM). The concentrations of C4 and C1-INH increased with advancing stage of disease and were above normal mean values in all stages. The concentration of IgG was below the normal mean value among all the patients and with the lowest concentration in stage III. Concentrations of IgA and C3 were above normal means but without significant relation to stages. There was a positive correlation between the concentrations of IgG and C1-INH in sera from patients with stage IV carcinoma, while the same correlation was negative in stages I-III. Although the results varied among the patients within each stage, the profiles of immunoglobulin and complement concentrations are of value in the preoperative staging of the disease.

Adult↗
PubMed1983

Interferon in suction blister fluid from psoriatic lesions.

Interferon (IFN) (at least 16 units/ml) was demonstrated in suction blister fluid obtained from lesional skin in nine of thirteen patients with psoriasis vulgaris and in two patients with allergic contact dermatitis, but not in blister fluid from unaffected skin. IFN was detected in only three of the sera from the patients with psoriasis. The difference in results between the blister fluid and the sera from these patients was statistically significant (P less than 0.025). Evidence was obtained which indicated that the activity was probably IFN-gamma (immune IFN), but the additional presence of IFN-alpha in some of the fluids could not be excluded. The data indicate that IFN is produced locally in the psoriatic lesions, most likely by activated T lymphocytes.

Adult↗
PubMed1983

The ontogeny of T-cell antigens in the thymus.

T-cell-specific antigens were examined in tissue sections of thymus from 24 fetuses, infants, and children. OKT6 monoclonal antibodies faintly stained some thymocytes at 11 weeks of gestation, whereas OKT3, OKT4 and OKT8 did not stain the thymocytes before 14 weeks of gestation. OKT4, OKT6 and OKT8 preferentially stained the cortical thymocytes, in contrast to OKT3, which preferentially stained the medullary thymocytes. The fraction of OKT3- and OKT6-positive cells increased gradually during fetal life. At 24 weeks of gestation about half of the medullary thymocytes were stained by OKT3 and nearly all the cortical thymocytes were stained by OKT6. The fraction of cells stained with OKT4 and OKT8 was maximal at 14-20 weeks of gestation and decreased slightly with increasing age. The preference for either cortex or medulla of cells possessing the various antigens was less pronounced in fetal life than in infancy and childhood. An anti-T-cell antiserum produced in rabbit stained most thymocytes at 10 weeks of gestation. The staining intensity increased gradually until 17 weeks of gestation and then remained constant.

Animals↗
PubMed1983

Myasthenia gravis: the specificities of skeletal muscle and thymus antibodies.

Antibodies against skeletal muscle antigens and against thymic myoid cells were examined in sera from 40 patients with myasthenia gravis (MG). Using an indirect immunofluorescence technique, antibodies against the surface of muscle cells were found in 23 sera, and antibodies against muscle cell cross-striations in 28 sera. Antibodies against thymic myoid cells were found in 27 sera, stained cells also occurring in fetal thymus from 14 weeks of gestation and in hyperplastic thymus from MG patients. Sera which stained myoid cells also stained muscle cell cross-striations. Sera from all the 20 patients with thymoma contained antibodies to a citric acid extract of skeletal muscle (CAE) as detected by indirect haemagglutination, whereas sera from 20 comparable patients without thymoma did not contain CAE antibodies. The myoid cell antibodies could be absorbed by homogenized muscle, but not by CAE-coated sheep erythrocytes. Different antibody patterns are seen among different MG patients; close associations were found between cross-striational and myoid cell antibodies, and between CAE-antibodies and a thymoma.

Antibody Specificity↗
PubMed1983

Effects of hydrocortisone and protein synthesis inhibitors on FcIgG receptors on cultured fetal rat brain cells.

The in vitro effect of protein synthesis inhibitors on FcIgG receptor (FcR) expression was studied in secondary cultures of fetal rat brain cells (FBC). Hemadsorption of antibody-coated sheep erythrocytes was used for the detection of FcR-positive cells. The addition of actinomycin D 0.5 and 2.5 micrograms/ml or cycloheximide 1.0 and 5.0 micrograms/ml to the growth medium did not change the FcR activity after 4 and 12 h. When the cells were cultured in medium containing hydrocortisone 10(-6) and 10(-7) M for 1, 2 or 3 days, the number of FcR-positive cells increased markedly. Confluent cultures of FBC and FBC undergoing in vitro neoplastic transformation were FcR negative. Hydrocortisone did not induce FcR activity in these cultures. The results indicate that the persistence of FcR on cultured FBC is not dependent on de novo protein synthesis. Hydrocortisone seems to prolong the period of FcR expression in FcR-positive cells.

Animals↗
PubMed1983

Demonstration of Ia-like antigens on T lymphocytes in lesions of psoriasis, lichen planus and discoid lupus erythematosus.

A combined indirect immunofluorescence technique with a murine monoclonal antibody against human Ia-like antigens (OKIal) and an IgG F(ab')2 preparation of a rabbit anti-T lymphocyte serum was used to study Ia-like antigens on T lymphocytes in skin lesions of psoriasis, lichen planus and discoid lupus erythematosus. The majority of the T lymphocytes in the various skin lesions expressed Ia-like antigens. T lymphocytes expressing Ia-like antigens were also demonstrated in the dermis and the epidermis in sections of unaffected skin, although of a markedly lower proportion than in affected skin. The results may indicate that the T lymphocytes in these skin lesions are activated cells involved in cell-mediated immune reactions.

HLA-D Antigens↗
PubMed1983

Development and distribution of HLA-DR antigens and Fc gamma receptors in the human thymus.

HLA-DR antigens and receptors for the Fc part of IgG (Fc gamma R) were studied in cryostat sections of thymus tissue from 24 fetuses, infants and children, using indirect immunofluorescence and indirect immunoperoxidase technique. HLA-DR antigens, detected by a monoclonal antibody (OKIa 1), occurred on the thymic epithelial cells at 11 weeks of gestation, while Fc gamma R, detected by immune complexes and by human heat-aggregated IgG, were present at 10 weeks of gestation. The intensity of the staining for HLA-DR antigens was maximal at about 18 weeks of gestation, while the Fc gamma R activity was maximal at 10-11 weeks. HLA-DR antigens also occurred along the membrane of a few thymocytes, especially in the cortex, while Fc gamma R-activity occurred along the membrane of most of the immature thymocytes. Thymocytes in suspension were examined from children only. Such thymocytes were not stained by OKIa 1, and only 2-6% had detectable Fc gamma R.

Animals↗
PubMed1983

HLA-DR antigens and Fc gamma receptors in fetal and infant thymus, examined by a double-marker technique.

HLA-DR antigens and receptors for the Fc part of IgG (Fc gamma R) were examined in cryostat sections and imprints of 12 thymuses from fetuses, infants and children. A double-marker technique, with an anti-T cell serum produced in rabbit and the monoclonal antibody OKIal, was used to study the localization of the thymocytes and the HLA-DR antigens. Membrane-bound HLA-DR antigens were found on about 5% of the thymocytes. A larger proportion of the thymocytes were surrounded by HLA-DR-positive material, probably associated with the thymic epithelial cells. Fc gamma R detected by human aggregated IgG were found on most epithelial cells, but only on a few thymocytes. However, in some areas Fc gamma R were demonstrated on most of the cells stained by the anti-T cell serum. A similar pattern for staining of Fc gamma R was obtained using an anti-Fc gamma R serum produced in rabbit. Fc gamma R were detected on one-third to one-half of the OKT3+ or OKT8+ thymocytes, but only on a few OKT4+ cells. Fc gamma R were present on nearly all the OKT6+ thymocytes at 11 weeks of gestation, whereas in thymuses from older individuals only a few OKT6+ cells had Fc gamma R. The proportions of double-stained cells did not vary much in fetuses older than 14 weeks of gestation, in infants or in children. The results indicate that HLA-DR antigens and Fc gamma R are not correlated to any specific stage of cell maturation.

Antibodies, Monoclonal↗