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Biomedical subjects

R Matre

Publications and source records attributed to R Matre.

At least 91 records · Page 5Linked to original sources

Expression of complement C3b/C4b receptors (CR1) on erythrocytes from patients with myasthenia gravis.

The complement C3b/C4b receptor (CR1) expression on erythrocytes (E) (ECR1) from patients with myasthenia gravis (MG) and from blood donors was measured using haemadsorption and indirect hemagglutination techniques. The ECR1 expression in patients with MG appeared to be normal. This was also true for the subgroup of MG patients with additional autoimmune diseases. No correlation between ECR1 expression and severity of myasthenic symptoms was demonstrated.

Adolescent↗

IgG subclass antibodies to serogroup B meningococcal outer membrane antigens following infection and vaccination.

IgG and IgG subclass antibodies to the outer membrane antigens from Neisseria meningitidis (serogroup B, serotype 15:P1.16) were quantitated by an enzyme-linked immunosorbent assay (ELISA) in sera from 40 patients with group B:15:P1.16 meningococcal disease and 24 volunteers immunized with a serotype 15:P1.16 outer membrane vesicle vaccine. A second injection was given 6 weeks after the first immunization. Patient sera obtained two and six weeks after onset of the disease had significantly higher levels of total IgG, IgG1, IgG2, and IgG3 antibodies to the outer membrane antigens than acute sera, convalescent sera from patients with systemic non-meningococcal bacterial infections and sera from healthy controls. The levels of total IgG and IgG1 remained high one and three years later. Sera from the vaccinees showed high levels of total IgG and IgG1 6, 12 and 26 weeks after the first immunization and high levels of IgG3 6 weeks after the second immunization. No increase of IgG2 or IgG4 levels was observed in the postimmunization sera. Immunoblotting of three convalescent sera demonstrated individual patterns of IgG subclass binding to various outer membrane antigens with most distinct binding of IgG1 and IgG3 antibodies to the class I protein, the H.8 lipoprotein and the lipopolysaccharide. Since IgG1 and IgG3 are the most effective antibodies for complement activation and phagocytosis, group B meningococcal disease and immunization with the serotype 15:P1.16 outer membrane vesicle vaccine stimulate production of those IgG subclasses which have the strongest opsonic and bactericidal activity.

Adolescent↗

Glomerular CR1 express in situ cofactor activity for degradation of C3b.

Adherence of sheep erythrocytes (E) sensitized with IgM antibodies (A) and C3b (EAC3b) to C3b/C4b receptors (CR1) in cryostat sections of human renal glomeruli was studied using the closed chamber technique. The adsorption was stable for at least 3 h at 37 degrees C. In the presence of purified factor I, the indicator cells, however, detached from the sections after 30 min at 37 degrees C. Factor H was not required. The release was not due to loss of CR1 activity in the tissue. The detached indicator cells were negative in the immune adherence test and were agglutinated by antibody to C3d, but not by antibody to C3c. Western blot of the detached indicator cells revealed the presence of C3d and C3c was found in the chamber fluid. Accordingly, detachment of the indicator cells was due to degradation of C3b to C3d with the release of C3c into the chamber fluid. Protease inhibitors did not prevent the detachment of the indicator cells. EAC3b incubated with sections of renal glomeruli preincubated with anti-CR1 antibody were not degraded. The results therefore indicate that CR1 in situ in renal glomeruli can provide the necessary cofactor activity for factor I-mediated degradation of C3b to C3d and C3c.

Complement C3b↗

The distribution of Fc gamma RI, Fc gamma RII and Fc gamma R III on Langerhans' cells and keratinocytes in normal skin.

The distribution of Fc-receptors for IgG (FcR) on human epidermal cells (EC) was characterized in situ using monoclonal antibodies (MoAbs) by indirect immunofluorescence staining of cryosections. The results showed heterogeneity of FcR expression on Langerhans' cells (LC) and keratinocytes (KC). The MoAb IV.3 against FcR II (CDw32) gave granular staining of most LC whereas the MoAb 32.2 against FcR I (CD64) occasionally stained a few dendritic cells. 32.2 demonstrated weak granular staining along the outer aspect of KC in stratum spinosum and stratum basale and intense staining of stratum corneum and stratum granulosum. The MoAbs Leu 11b against FcR III (CD16) and B1D6 reacting with a placental FcR with low affinity for IgG gave intense linear membrane staining of KC. Leu 11b produced strongest staining of stratum granulosum and B1D6 the strongest staining of stratum spinosum and basale. The results confirm our previous observations of FcR in situ on LC and KC in normal skin using functional assays and demonstrate that these EC possess different types of low affinity FcR. The data support the contention of an immune function of KC. FcR may be mediators for interaction between KC and LC. The FcR activity in stratum granulosum may have an immune function as a barrier against microorganisms and other antigens.

Antibodies, Monoclonal↗

Who gets a second primary cancer after gastric cancer surgery?

Eleven patients presented with a second primary cancer during follow-up after surgery for gastric carcinoma. In these patients the serum concentrations of C1-INH and IgG prior to gastric cancer surgery were similar to those of 53 patients with recurrence of gastric cancer. In these two groups, the preoperative C1-INH concentrations were higher and IgG lower (P less than 0.001 and P less than 0.05) when compared to 36 patients alive and disease-free 5 years after surgery. The median time between surgery and signs of recurrence was 11 months, whereas the median time until signs of the second primary cancer was 4 years. A patient with gastric carcinoma who pre-operatively has high C1-INH and low IgG is liable either to have recurrence or to develop a second primary cancer. Our data indicate that these variables represent a cancer susceptibility feature appropriate to the host.

Aged↗

In situ localization of interferons in psoriatic lesions.

An indirect immunofluorescence technique, using murine monoclonal antibodies (MoAbs) against human IFN-alpha and human IFN-gamma was used to study IFNs in cryostat sections from psoriatic skin lesions. The IFNs were more pronounced in sections from highly active psoriasis than in sections from stationary psoriasis. In highly active psoriatic lesions IFN-alpha was localized to keratinocytes is stratum basale, to some epidermal dendritic cells, probably Langerhans cells, and to some mononuclear cells in dermis. IFN-alpha was usually not detected in sections from stationary psoriasis. IFN-gamma was localized to stratum corneum, to keratinocytes around microabcesses and to mononuclear cells in the dermal cell infiltrates, predominantly in highly active psoriatic lesions. Both IFN-alpha and IFN-gamma were localized to some endothelial cells in the papillary dermis. The MoAbs did not stain sections from unaffected skin from patients with psoriasis or sections from healthy individuals. The findings indicate that the IFN system in the skin may be of significance in the pathophysiology of psoriasis.

Antibodies, Monoclonal↗

Solubilization of human peripheral nerve Fc gamma receptors and purification of a functional 40 kDa receptor.

Extracts from myelinated and unmyelinated nerves, prepared using Tris-HCl buffer with EDTA and ME, contained functionally active receptors for the Fc region of IgG (FcR). This was evident from the results obtained in indirect haemagglutination and rosette inhibition assays. Using a monoclonal antibody, a functional active 40-kDa FcR was purified from the nerve extracts. The receptor was a single-chained glycoprotein with low affinity for native IgG, apparently belonging to the FcRII family. In addition, peripheral nerve extracts contain FcR not recognised by the monoclonal antibody.

Antibodies, Monoclonal↗

Isolation and characterization of complement receptors CR1 from human peripheral nerves.

Extracts from myelinated and unmyelinated nerves, prepared using Nonidet P-40, contained receptors for C3b/C4b (CR1). Extracts from myelinated nerves inhibited EAC3b rosette formation with peripheral blood leucocytes and agglutinated EAC3b, whereas extract from unmyelinated nerves did not. Rosette formation with EAC3bi or EAC3d was not affected. CR1 in extracts from myelinated nerves also expressed decay-accelerating activity of the alternative pathway C3 convertase and cofactor activity in factor I-mediated cleavage of C3b, whereas CR1 in extract from unmyelinated nerves did not. Monoclonal anti-CR1 antibodies, but not monoclonal anti-CR2 (C3d receptors) or anti-CR3 (C3bi receptors) antibodies inhibited the functional activities. Accordingly, CR1 are the only C3 receptor present in the extracts and only CR1 in myelinated nerve extracts are functionally active. CR1 in both myelinated and unmyelinated nerve extracts had a molecular weight of approximately 190 kDa. The electrophoretic mobility did not change after reduction and the 190 kDa band was stained by concanavalin A, indicating that the CR1 are single-chained glycoproteins. Binding to lentil lectin-Sepharose 4B further sustained the glycoprotein nature of the CR1. Periodic acid abolished functional activities of CR1, whereas trypsin and heat did not, indicating the functional significance of the carbohydrate moiety. That CR1 are functionally active in myelinated nerves, but not in unmyelinated nerves, may therefore be due to differences in the carbohydrate moiety. The cofactor and decay-accelerating activities of CR1 may be of significance in the pathogenesis of demyelinating polyneuropathies by limiting complement activation.

Antibodies, Monoclonal↗

Localization of Fc gamma receptors and complement receptors CR1 on human peripheral nerve fibres by immunoelectron microscopy.

The localization of receptors for the Fc part of IgG (Fc gamma R) and for the complement C3b/C4b components (CR1) on human peripheral nerve fibres was investigated by indirect immunoperoxidase staining of frozen nerve sections with monoclonal antibodies. Transmission electron microscopy revealed that Fc gamma R and CR1 are localized to the entire surface membrane and inner membrane (axolemma) of the Schwann cell. Myelin and axons were not stained. The presence of Fc gamma R and CR1 in human Schwann cells adds further evidence for the immunocompetence of these cells.

Animals↗

Serum C1-esterase inhibitor, an essential and independent prognosticator of gastric carcinoma.

The preoperative concentrations of IgG were lower (P less than 0.002) and the concentrations of C4 and C1-INH higher (P less than 0.01 and P less than 0.001) in 29 patients with recurrence after potentially curative resection of gastric carcinoma, than in 31 patients alive and disease-free 5 years after surgery. These differences between the two groups of patients were consistent within each of six groups of disease extent. In each of the two groups of patients, the preoperative concentrations of IgG, C4 and C1-INH had no significant variation with the extent of disease (P greater than 0.05 or greater). Of our variables, C1-INH was the most potent prognosticator and discriminated between patients with and without recurrence with 80% accuracy. Furthermore, the predictive prognostic value of C1-INH at the time of surgery was superior to the prognostic value of the extent of disease (F values 27.00 and 12.69). Apparently, the preoperative C1-INH concentration is an essential and independent prognostic parameter of gastric carcinoma. We assume that C1-INH reflects an additional prognostic feature appropriate to the tumour or the host. Our finding that the interval between surgery and death from recurrence had an inverse relation to the preoperative C1-INH concentration also supports this assumption.

Adenocarcinoma↗

Effect of hyperbaric oxygen treatment on immunological parameters in multiple sclerosis.

Hyperbaric oxygen (HBO) treatment has been reported to cause amelioration of clinical symptoms in patients with multiple sclerosis (MS). We have treated 10 MS patients with hyperbaric oxygen (100% O2 at 2 atmospheres absolute for 90 min daily for a total of 20 exposures), and performed immunological studies on peripheral blood and cerebrospinal fluid (CSF). After treatment there was a significant increase in total and helper T lymphocyte counts in peripheral blood, as well as an increase in both E, Fc gamma and C3b receptor-bearing lymphocytes. The responses to the mitogens PHA, con A and PWM were unchanged. Granulocytes showed an increased proportion of Fc gamma receptor and C3b receptor positive cells after treatment. The O2 consumption of granulocytes also increased, but phagocytosis, as measured by chemiluminescence, was unchanged. Serum IgA levels were slightly increased, while IgG and IgM concentrations remained unchanged after treatment. Cerebrospinal fluid cell counts, protein and IgG concentrations, as well as IgG indexes remained unchanged.

Adult↗

Associated disorders in myasthenia gravis: autoimmune diseases and their relation to thymectomy.

The prevalence of myasthenia gravis (MG) in the counties of Hordaland and Sogn & Fjordane on January 1, 1984 was 9.6 per 100,000 inhabitants. Other autoimmune diseases were found in 11 out of 48 MG patients. The occurrence of autoimmune thyroiditis (5 patients, 10.4%) and systemic lupus erythematosus (4 patients, 8.3%) in the MG patients was clearly higher than that reported in the general population. Rheumatoid arthritis was found in 2 patients (4.2%). The autoimmune diseases were mainly recorded among the nonthymectomized MG patients. In addition to those with definite diseases of autoimmune nature, 3 other MG patients had thyroid antibodies and 1 had antinuclear factor without clinical evidence of autoimmune disease. Seven MG patients (14.6%) had unspecific arthralgia during active periods of MG. Two MG patients had ankylosing spondylitis.

Arthritis, Rheumatoid↗

Purification of a functional 40 kD human placental Fc gamma-receptor using a monoclonal antibody.

F(ab')2-fragments of a mouse monoclonal antibody (B1D6) reacting with placental receptors for the Fc part of IgG (FcR) were used as affinity reagents for the purification of an antigen from placental extract (PE). The antigen agglutinated ovine erythrocytes (E) sensitized with rabbit antibodies (A) (EA), but not E or E sensitized with F(ab')2-fragments. It reduced the EA rosette-formation with mononuclear cells and the binding of soluble immune complexes to placental tissue. The antigen bound to aggregated IgG and Fc-fragments of IgG, but not to native IgG or F(ab')2-fragments of IgG. The data indicate that the purified antigen possesses FcR activity with low affinity for IgG. SDS-PAGE and Western blot showed one distinct band of approximately 40 kD. The electrophoretic mobility did not change after reduction and the band reacted with concanavalin A indicating that the FcR are single-chained glycoproteins.

Antibodies, Monoclonal↗

The acute effect of passive Heymann nephritis on renal blood flow and glomerular filtration rate in rats.

The acute renal hemodynamic changes during induction of passive Heymann nephritis (PHN) may be of importance for the understanding of the pathogenesis of this model. We studied the renal blood flow (RBF) and glomerular filtration rate (GFR) during and after infusion of anti-FxlA into the left renal artery of rats for 10 min. 3 control groups were given 0.9% NaCl, 1 and 2 mg of normal rabbit IgG, respectively. The experimental groups were given 1 and 2 mg IgG fraction of anti-FxlA. Compared to controls, both RBF and GFR were substantially reduced during the first 20-30 min after infusion and remained unaltered for the rest of the observation period. After 20-30 min, RBF in the 1-mg group was 4.8 +/- 0.77 ml/min/g kidney weight versus control, 6.4 +/- 1.23 (NS), and in the 2-mg group, 3.5 +/- 0.65 ml/min/g versus control, 6.4 +/- 1.07 (p less than 0.05). Similarly, in the 1-mg group, GFR was 0.40 +/- 0.08 ml/min/g versus control, 0.76 +/- 0.11 (p less than 0.05), and in the 2-mg group, 0.14 +/- 0.05 versus control, 0.77 +/- 0.12 (p less than 0.0001). The reductions were greater in the 2-mg than in the 1-mg infused experimental groups, but this difference did not reach statistical significance. Immunofluorescence showed typical granular fluorescence of rabbit IgG along the glomerular basement membrane, and electron microscopy showed subepithelial immune deposits. This indicates that in the initial phase of PHN, corresponding with the formation of immune complexes, a pronounced fall in RBF and GFR occurs.

Animals↗

Serum opsonins to serogroup B meningococci in meningococcal disease.

The opsonic activity to serogroup B meningococci (B:15:P1.16) was measured in sera from 101 patients with meningococcal disease using a chemiluminescence method. On admission to hospital the opsonic activity was lower in 12 patients who died than in survivors (p = 0.0007). A close association was observed between the opsonic activity and the duration of symptoms before admission, the severity of the disease, and the levels of IgG antibodies to the outer membrane complex (15:P1.16). The opsonic activity was low in 2 premorbid sera compared to healthy controls. The mean opsonic activity peaked 2 weeks after admission and was still high 3-5 years later. Meningococcal strains of different serogroups, serotypes and subtypes induced a similar increase in opsonic activity to B:15:P1.16 meningococci. No increase in activity was observed in sera from patients with meningitis and septicemia caused by other bacteria. Serum opsonins seem to be of significant importance in the host defence against serogroup B meningococci.

Adolescent↗

Fc gamma-receptor as a functional marker on epidermal Langerhans' cells in situ.

Fc gamma-receptors (FcR) in cryostat sections of normal human skin were detected with soluble immune complexes of horseradish peroxidase (HRP) and rabbit IgG anti-HRP (HRP-anti-HRP). The binding of HRP-anti-HRP to Langerhans' cells (LC) was demonstrated using a double immunofluorescence staining in which LC were identified with a CD1a specific monoclonal antibody (Leu 6). The immune complexes gave granular staining of CD1a+ epidermal cells in sections of all specimens from normal skin. The mean percentage of CD1a+ cells that were FcR+ was 49 +/- 11 (n = 8). The FcR+/CD1a+ cells had a clearly defined dendritic pattern. The staining intensity of LC with HRP-anti-HRP was weaker than the intense staining of CD1a-macrophages in the dermis. Results of inhibition experiments indicate that human epidermal LC express low affinity FcR, but the presence of high affinity FcR as well cannot be excluded. The demonstration of FcR expression on normal LC clarifies previous uncertainty on LC membrane receptors, though the functional significance of these receptors is still not well understood.

Antigen-Antibody Complex↗

Immunological changes following treatment of psoriasis with cyclosporin.

Five patients treated for severe plaque psoriasis with cyclosporin were studied. Cryostat sections of biopsies taken from the same lesional skin areas before and during therapy were examined for immunological surface markers, and deposits of immunoglobulins and complement using a panel of monoclonal and polyclonal antibodies. Fc gamma-receptors (FcR) were detected using soluble immune complexes of horseradish peroxidase (HRP)-anti-HRP. During therapy the dermal accumulation of T-lymphocytes (CD3+, CD4+, CD8+ and IL2R+ cells), macrophages (OKM1+), CD1a+ and FcR+ cells decreased, paralleling clinical improvement. However, in normalized skin there were still patchy accumulations of mononuclear cells in some dermal papillae close to the dermo-epidermal junction. In the epidermis CD8+ and IL2R+ cells rapidly disappeared during clinical improvement. The numbers of epidermal dendritic CD1a+ and HLA-DR+ cells increased and their distribution pattern became regular. The percentage of CD1a+ epidermal cells expressing FcR was reduced during therapy. IgM deposits regularly found along the dermal vessels and the dermoepidermal junction before therapy gradually disappeared. Serum levels of IgA increased and C4 decreased, though not significantly. Serum levels of gamma-IFN, alpha 2-IFN and TNF remained unchanged. The findings indicate that cyclosporin inhibits various sides of the immune response.

Adult↗