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R Nilsen

Publications and source records attributed to R Nilsen.

At least 73 records · Page 4Linked to original sources
PubMed1984

In situ characterization of mononuclear cells in human dental periapical inflammatory lesions using monoclonal antibodies.

Mononuclear cells in cryostat sections of human dental periapical inflammatory lesions were studied with the aid of murine monoclonal antibodies and with indirect immunofluorescence microscopy. T lymphocytes (OKT3-positive cells) made up a major part of the cells in the infiltrates. They were found mainly in clusters, although single cells were also seen. T helper cells (OKT4) were more numerous than suppressor/cytotoxic T cells (OKT8-positive cells), with a ratio of approximately 2:1. Langerhans cells (OKT6-positive cells) were not demonstrated: only a few scattered HNK 1-positive cells, probably natural killer cells, were detected. A large number of OKM1- and OKIa 1-positive cells were detected in the infiltrates. Their size and number varied considerably in the different areas of the sections. These cells are probably macrophages. Sheets of small OKIa 1-positive cells were also demonstrated, indicating the presence of B lymphocytes or activated T lymphocytes. The results indicate that immune reactions may be of importance in the pathogenesis of periapical inflammatory lesions.

Antibodies, Monoclonal↗
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

Enzyme histochemical characterization of mononuclear cells in human dental periapical chronic inflammatory lesions.

Cell infiltrates in sections of paraffin-embedded tissue of 36 human periapical inflammatory lesions (15 granulomas and 21 cysts) were examined by staining for acid alpha-naphthyl acetate esterase (ANAE). Thirty-four of the lesions showed ANAE reactive T lymphocytes, plasma cells and cells of the monocyte/macrophage cell line. Large granular lymphocytes (NK cells) could not be identified with certainty among the ANAE positive cells. Two specimens were free of ANAE reactive cells. Differential cell counts on sections from 15 lesions (7 granulomas and 8 cysts) showed that T lymphocytes were the predominating ANAE reactive cells (23%), followed by plasma cells (15%) and monocytes/macrophages (11%). 51% of the inflammatory cells were ANAE negative. There was no marked difference between the granulomas and the cysts. Inhibition with NaF (10-100 mM) gave a gradual reduction in number of ANAE positive cells, some macrophages being the only cells resistant to 100 mM NaF. The results suggest that both humoral and cellular immune reactions are likely to occur in periapical inflammatory lesions.

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

Deposits of immunoglobulins and complement factor C3 in human dental periapical inflammatory lesions.

Thirty-five human dental periapical lesions were studied by immunofluorescence technique using polyclonal anti-IgG (F(ab)2), anti-IgM (F(ab)2), anti-IgA (F(ab)2), anti-IgE and anti-C3c as well as monoclonal anti-IgE. Prewashed ethanol-fixed specimens showed a great number of plasma cells staining for IgG. Cells containing IgA, IgM or IgE were also seen. Deposits of immunoglobulins and C3c suggestive of immune complexes were demonstrated using a double staining technique combining FITC-labeled immunoglobulins with TRITC-conjugated C3c. The complexes were located intracellularly in macrophages, as well as in vessel walls and in the basement membrane zone of proliferating epithelium. Immune complexes may be involved in the epithelial proliferation in those granulomas which lead to cyst formation. Monoclonal anti-IgE demonstrated plasma cells and mast cells, as well as intercellular IgE in epithelial strands of granulomas. The role of IgE in the epithelium is obscure. The study strongly indicates the involvement of hypersensitivity reactions type I and III in periapical inflammatory lesions.

Adult↗
PubMed1983

Multicentric reticulohistiocytosis: a case report.

With the present case report we call attention to the clinical entity of multicentric reticulohistiocytosis (MR). Referring to earlier case reports on this rare condition we present the history, clinical and histopathological findings. We stress the importance of revealing possible underlying internal diseases, including malignancies, and also the importance of histological examination of synovium when synovectomies are carried out in patients with arthritis of unknown cause, as arthritis commonly precedes the mucocutaneous lesions by years.

Arthritis↗
PubMed1983

Characterization of mononuclear cells in sarcoid skin lesions using monoclonal antibodies.

Epithelioid cells, giant cells and mononuclear cells in cryostat sections of lesional skin from 5 patients with chronic cutaneous sarcoidosis were characterized using an indirect immunofluorescence test with monoclonal antibodies. OKM1 (monocyte) antibody stained both epithelioid cells and giant cells as well as some cells in the periphery of the granulomas. OKM1 which reacts with most monocytes in peripheral blood, did not react with tissue macrophages in sections of normal skin, liver, spleen and kidney. The results indicate that the epithelioid and giant cells in the sarcoid granulomas are derived from blood monocytes. OKT3 (pan T cell) antibody stained the majority of cells surrounding the epithelioid cell islands. Examination of adjacent sections showed that more OKT4+ (helper/inducer) than OKT8+ (suppressor/cytotoxic) cells were present in the sarcoid lesions examined.

Adult↗
PubMed1982

A procedure for selecting specific areas of sections for comparative light and electron microscopic studies.

The paper describes a method which enables correlative light and electron microscopical studies to be made of specific tissue structures or of individual cells. For this purpose a new specimen marker has been constructed. The device, which is attached to the objective of a light microscope, permits the operator to examine and exactly encircle the selected area without changing the objective. The technique is illustrated by two examples using immunoelectronmicroscopy.

Basement Membrane↗
PubMed1982

The localization of glomerular C3b receptor by immunoelectron microscopy.

By an indirect immunoperoxidase technique, rabbit antiserum to solubilized C3b receptor stained the glomeruli in cryostat sections of human kidney. The staining was localized to the glomerular basement membrane zone. Glomeruli in sections of aldehyde-fixed paraffin-embedded tissue did not stain. However, if the sections were pretreated with proteolytic enzymes, the glomeruli were stained by the antiserum as in the cryostat sections. Electron microscopy revealed that the reaction product was located in the cell membrane of the epithelial cells. In some cells the reaction product was also found in vacuoles in the cytoplasm. The basement membrane and endothelial and mesangial cells did not stain.

Basement Membrane↗
PubMed1982

In situ characterization of cell infiltrates in human dental periapical granulomas. 1. Demonstration of receptors for the Fc region of IgG.

The aims of the present study were to demonstrate FcR activity of dental periapical granulomas and to correlate the activity with the degree of lymphoreticular cell infiltration. Cryostat sections of 46 out of 51 granulomas adsorbed sheep erythrocytes(E) sensitized with rabbit IgG antibodies (A) (EA). No adsorption occurred using erythrocytes sensitized with F(ab')2 fragments of IgG. IgG and Fc fragments of human of rabbit IgG inhibited the binding of EA, whereas F(ab')2 fragments, human IgA, IgM or albumin did not, indicating the presence of receptors for the Fc region of IgG. Periodate, neutral formaldehyde and phospholipase C abolished the FcR activity whereas neuraminidase had no effect. Comparison of sections binding EA and adjacent sections stained with haematoxylin and eosin showed that EA adhered to areas infiltrated with mononuclear cells. The degree of binding of EA coincided with the density of mononuclear cell infiltration. Point attachments between the tissue sections and the adsorbed EA could be demonstrated by scanning electron microscopy. Sections with no infiltrates did not bind EA.

Adsorption↗
PubMed1982

Localization of Fc gamma receptors in the human central nervous system.

Immune complexes of horseradish peroxidase (HRP) and rabbit IgG antibodies to HRP were used to study the Fc gamma receptors in the human central nervous system (CNS). The peroxidase activity was demonstrated with 3,3'-diaminobenzidine tetrahydrochloride and H2O2. The majority of the pia and arachnoid cells of the leptomeninges, the stroma cells of the arachnoid granulations and the adventitial cells in the perivascular spaces of the nervous tissue were stained. The villi of the choroid plexus were also stained. By electron microscopy the reaction products were localized to the plasma membranes of the stroma cells and at the basal aspects of the epithelial cells in the choroid villi. In addition, reaction product was demonstrated on pericytes of some of the brain capillaries. The immune complexes did not bind to the brain parenchyma.

Animals↗
PubMed1981

Enzyme histochemical studies of acid phosphatase isoenzymes in induced heterotopic bone formation in guinea pigs.

A bone induction model was used to study the effect of different pretreatments and inhibitors added to the substrate media used for the histochemical demonstration of acid phosphatase activity. Two different acid phosphatases (AcP) were demonstrated. The AcP of matrix-producing cells exhibited resistance to pretreatment with EDTA while it was sensitive to tartrate added to the incubation medium. The AcP in dentin resorbing cells was EDTA sensitive but resistant to tartrate. The AcP activities in both resorbing and matrix-producing cells generally sensitive to fluoride, copper and molybdate. In some of the dentinoclasts, fluoride resistant AcP was observed. The results suggest previous investigations on normal bone formation, suggesting that at least two different isoenzymes of AcP exist. One of these seemed to be related to matrix production and mineralization of the new heterotopic bone.

Acid Phosphatase↗
PubMed1981

Enzyme histochemical studies of induced heterotopic cartilage and bone formation in guinea pigs with special reference to acid phosphatase.

Heterotopic bone and cartilage formation was studied in a bone induction model in abdominal muscles of guinea pigs using the demineralized allogenic dentin as inductive material. The light microscopic study showed high activity of acid phosphatase (AcP) and leucine aminopeptidase (LAP) in young matrix-producing cells. The highest activity was seen in cells surrounded by unmineralized matrix. In the surrounding matrix there was strong staining of AcP, especially in matrix with high glycosaminoglycan content. Electron microscopic studies of AcP in sections from unfixed frozen tissue showed intracellular activity mainly located in lysosomes. Extracellular AcP activity was found in matrix vesicles in the newly formed hard tissue. It was most pronounced in areas of cartilaginous differentiation. By means of energy dispersive X-ray microanalysis in a scanning transmission electron microscope, the deposits were confirmed to contain led precipitates. With the exception of some lysosomal staining, prefixation with formaldehyde prevented demonstration of the enzyme activity. Both AcP and LAP may be involved in degradation of organic components of the matrix which enable the matrix to mineralize.

Acid Phosphatase↗
PubMed1981

Ultrastructural and immuno-electron microscopic study in a case of epidermolysis bullosa acquisita.

Skin biopsies from a patient with epidermolysis bullosa acquisita (EBA) were studied ultrastructurally and by immuno-electron microscopy. The specimens were taken from non-predilection areas as well as of the skin predilection areas of the patient. In vivo deposits of IgG were found below the lamina densa associated with the anchoring fibrils in all areas of the skin. The bullae and the artificial friction blisters appeared in the same position on the dermal side of lamina densa. The results suggest that epidermolysis bullosa acquisita is a distinct nosologic entity. The close resemblance of epidermolysis bullosa acquisita to cicatricial pemphigoid in immunofluorescence studies makes the use of immuno-electron microscopy important in the classification of the diseases.

Adult↗