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Biomedical subjects

E Linder

Publications and source records attributed to E Linder.

At least 91 records · Page 5Linked to original sources
PubMed1983

Membrane 126-kilodalton phosphoglycoprotein associated with human carcinomas identified by a hybridoma antibody to mammary carcinoma cells.

A large number of hybridomas producing antibodies to the membrane fraction of a human mammary carcinoma cell line have been produced. Among those hybridoma antibodies that bound to exposed surface membrane epitopes on the human mammary carcinoma cell line BT-20, one has been found to bind to all tested breast carcinoma cell lines as well as to a number of other human carcinomas by solid-phase radioimmunoassay. This hybridoma antibody, designated 10-3D2, does not bind to normal mammary epithelium, a variety of control cell lines, or selected normal human tissue homogenates. The 10-3D2 hybridoma antibody identifies by immunoprecipitation a membrane 126-kilodalton protein which is indistinguishable in different tumor cells. It is glycosylated by reference to incorporation of [3H]glucosamine and also is phosphorylated by reference to incorporation of 32P. It is present in a finely granular pattern on the cell surface of mammary carcinoma cells with concentration at the sites of apparent cell-cell contact. This 126-kilodalton phosphoglycoprotein, which we have consistently been unable to identify by immunoprecipitation of intrinsically labeled normal cells, may represent a heretofore unrecognized tumor-associated marker for human mammary carcinomas as well as certain other types of human neoplasms.

Antibodies, Monoclonal↗
PubMed1983

Antibody-independent binding and activation of complement by Schistosoma mansoni adult worms.

The in vitro binding serum complement (C) components to Schistosoma mansoni worms was studied. By exposing frozen sections of adult male and female parasites to normal human serum, binding of both classical and alternative pathway C components was observed. By immunofluorescence (IFL) microscopy selective binding of Clq, C4 and C3 to the schistosomal tegument, internal structures, the intestinal tract and eggs was seen. The C4 and C3 binding was completely abolished in the presence of 10 mM EDTA. EGTA also completely inhibited binding of C4 and most of the C3 binding. These results suggest that C binding to S. mansoni adult worms occurs mostly by the classical activation pathway. However, the partial Ca2+ independence of C3 binding and the demonstrated binding of the regulatory protein beta 1H suggests that worms are capable also of C3 binding by the alternative pathway. No C binding occurred to intact worms. Although some in vivo bound immunoglobulin appeared to be present occasionally at the parasite surface and in the gut, this material did not account for the demonstrated extensive C deposition upon incubation of frozen sections with normal human serum in vitro. Antibody independence of the observed classical pathway C binding was further indicated by binding of isolated Clq to the same structures capable of binding C components from serum.

Animals↗
PubMed1983

Cellular origin and differentiation of renal carcinomas. A fluorescence microscopic study with kidney-specific antibodies, antiintermediate filament antibodies, and lectins.

Frozen sections of human renal carcinomas were studied in indirect immunofluorescence using antibodies against intermediate filaments of cytokeratin, desmin and vimentin type, and against proximal tubular brush border and distal tubular Tamm-Horsfall glycoprotein antigens, as well as with fluorochrome-labeled lectins in an attempt to study the origin and stage of differentiation of renal carcinomas. Eighty per cent of the renal carcinomas expressed the brush border antigens, whereas the Tamm-Horsfall glycoprotein could not be found. Antibodies against epidermal cytokeratins reacted only with collecting ducts in normal kidney, whereas antibodies against cytokeratins of Madin-Darby canine kidney epithelial cell line also reacted with glomerular and tubular epithelium. In 93% of the carcinomas tumor cells showed reactivity with both types of antikeratin antibodies. Vimentin, the cytoskeletal protein of mesenchymal cells, was present in the carcinoma cells of 53% of the tumors, although it was not present in normal tubular epithelium. Moreover, vimentin was expressed together with cytokeratin in the carcinoma cells in 57% of the keratin-positive samples as judged by double immunostaining, whereas the muscle type of intermediate filament protein, desmin, was not seen in the malignant cells. Binding sites for Lotus tetragonolobus agglutinin and soybean agglutinin, normally present in the cells of proximal tubules, were lacking or only faintly detectable in the neoplastic cells. Dolichos biflorus agglutinin, normally present in collecting ducts, was not detected in the tumors. The results show that most renal carcinomas express cytokeratin antigens as a sign of their epithelial origin and also show characteristics of proximal tubular cells. On the other hand, the results indicate that lectin-binding sites typical for normal differentiated tubular cells are profoundly modified in renal carcinomas. Ulex europaeus agglutinin did not bind to the malignant cells but decorated the endothelial cells of the tumors.

Antigens↗
PubMed1983

Complement-mediated binding of monocytes to intermediate filaments in vitro.

An in vitro model for complement (C)-mediated monocyte binding to injured cells is described. This model is based on the property of cytoskeletal intermediate filaments (IMF) to directly and independently activate serum C via the classic pathway. Fixed monolayers of cultured fibroblasts, endothelial cells, and L 132 epithelial cells were each used as targets. The authors first subjected the target cells to limited detergent extraction in order to make permeable the plasma membrane, and then exposed them to normal human serum. Immunohistologic analysis demonstrated that this process permitted binding of clearly demonstrable amounts of C1q, C4, and C3 to cytoplasmic loci containing IMF. The target cells were then incubated for various lengths of time with peripheral blood mononuclear cells containing about 20% monocytes. Preferential binding of monocytes was demonstrated by histochemical and immunologic staining methods. Only 5% of the attached cells were B lymphocytes. By transmission electron microscopy the attached cells exhibited typical monocyte morphology. Attachment to target cells involved contact with areas rich in IMFs and led to signs of activation; both an increased number of cytoplasmic organelles and phagocytosis of target cell material were observed. Attachment of monocytes was clearly dependent on serum treatment of the targets; the ratio was 10:1 when compared with control experiments using target cells that had not been incubated with serum. It is reasonable to consider that bound monocyte-derived macrophages associate with activated C components, most likely C3b fragments or C1q, for which monocyte surface receptors have been established. This mechanism may be triggered in various inflammatory reactions involving cell and tissue injury and as an event in the final stages of macrophage-mediated removal of injured or nonviable cells.

Animals↗
PubMed1982

Creatine kinase isoenzyme (CK-BB) in combination to prostatic acid phosphatase measured by RIA in the diagnosis of prostatic cancer.

Creatine kinase isoenzyme (CK-BB) measured by mass was used to determine its value in the early diagnosis of prostatic cancer. Sera of patients with prostatic carcinoma of various stages (treated and untreated) were compared to normal male sera and sera of patients with benign hyperplasia of the prostate (BPH) with respect to CK-BB. The sera were simultaneously tested for PAP content. The sensitivity of the CK-BB-RIA was 1.63 +/- 0.08 microgram/1 and reproducibility in the higher and lower concentration range 7.6% and 10.5%, respectively. CK-BB alone or in combination with PAP is no marker for early detection of prostatic cancer. In individual cases changes occurred similar to those found with a malignant growth of the prostate.

Acid Phosphatase↗
PubMed1982

Distribution of exposed and hidden carbohydrates of Schistosoma mansoni adult worms demonstrated by selective binding of fluorochrome-conjugated lectins.

The distribution of exposed and hidden lectin-binding glycoconjugates in adult Schistosoma mansoni worms was studied. Fluorochrome-conjugated lectins were allowed to react both with intact worms and with frozen sections of worms. The results show a selective reactivity of lectins with tegumental surface structures, the intestine, eggs and basement membranes. Strong binding of wheat germ agglutinin (WGA) was seen to the exposed surface of intact worms. Peanut agglutinin (PNA), Ricinus communis agglutinin (RCA) and concanavalin A (Con A) gave a weaker reaction. There was a preferential affinity of PNA and RCA to the spikes covering the tubercles of male worms whereas Con A gave a more uniform staining pattern. Internal structures exposed in frozen sections of worms gave distinct staining reactions. Binding sites for Con A were widely distributed throughout the worm. PNA produced a more selective binding and was the only lectin staining basement membranes as distinct structures. There was a strong selective staining of the gut with soybean agglutinin (SBA) and RCA. Eggs seen in large quantitites inside female parasites reacted strongly with SBA and PNA and less intensely with RCA and WGA. The observed selectivity of lectin binding may reflect physiological function. The results may be important as a basis for using lectin affinity-chromatography for purification and characterization of worm constituents.

Animals↗
PubMed1982

Antibody-independent binding of Clq and activation of serum complement by human skin in vitro.

By exposing frozen sections of human skin to fresh normal human serum, binding and activation of complement was observed. Attached complement components Clq, C4, and C3 were detected by immunofluorescence microscopy using anticomplement conjugates. Isolated Clq bound to the same structures as serum Clq, C4, and C3 and binding of C4 and C3 was dependent on binding of Clq. The complement components bound to capillary endothelial cells and to fibrillar structures in the dermis and reacted with the epidermis. Complement binding dermal fibrillar structures in adult skin were scant but abundant in fetal skin. They had similar distribution as "microfibrils" demonstrable by human autoantibodies. Antibody independence of the Clq binding was shown using isolated Clq and by the observed constant and reproducible binding of complement of normal sera lacking antibodies to the described target structures. The observations suggest that antibody independent binding of complement should be considered as a possible mechanism leading to dermal complement deposition in vivo.

Adult↗
PubMed1982

Three step purification of C1q by DNA precipitation, ion exchange and lectin affinity chromatography.

The difficulties associated with the isolation of pure C1q in sufficient amounts are reflected by the substantial number of isolation procedures, which are being published. The two major problems are a low yield and contaminating immunoglobulins. In addition, some isolation protocols appear to produce C1q contaminated with an inhibitor (C1q-INH). The present isolation protocol involves precipitation of C1q by DNA, chromatography using Sephadex QAE A 50 followed by Con A affinity chromatography. By this combination of purification steps maximal advantage was taken of the cationic properties and high carbohydrate content of the C1q molecule. The yield was 1-2 mg C1q per 100 ml serum. The isolated C1q was free of any demonstrable contaminants as demonstrated by Ouchterlony double diffusion and polyacrylamide gel electrophoresis.

Chromatography, Affinity↗
PubMed1982

Ulex europaeus I lectin as a marker for vascular endothelium in human tissues.

Ulex europaeus I agglutinin, a lectin specific for some alpha-L-fucose-containing glycocompounds, was used in fluorescence microscopy to stain cryostat sections of human tissues. The endothelium of vessels of all sizes was stained ubiquitously in all tissues studied as judged by double staining with a known endothelial marker, antibodies against human clotting factor VIII. Cultured human umbilical vein endothelial cells, but not fibroblasts, also bound Ulex lectin. The staining was not affected by the blood group type of the tissue donor. In some tissues Ulex lectin presented additional binding to epithelial structures. Also, this was independent on the blood group or the ability of the tissue donor to secrete soluble blood group substances. Lotus tetragonolobus agglutinin, another lectin specific for some alpha-L-fucose-containing moieties failed to react with endothelial cells. Our results suggest that Ulex europaeus I agglutinin is a good histologic marker for endothelium in human tissues.

Blood Vessels↗
PubMed1982

Measurement of prostatic acid phosphatase in serum and bone marrow: radioimmunoassay and enzymic measurement compared.

We quantitated the concentrations of prostatic acid phosphatases (EC 3.1.3.2) in serum and bone-marrow aspirates with three commercial radioimmunoassay kits, and the catalytic activities with a thymolphthalein monophosphate-based enzyme test. The enzyme's immunological activity in serum was compared with its catalytic activity for its potential as a detector of early prostatic cancer and its performance as an early marker of metastatic activity in bone. Neither measurement is useful for detecting early stages of prostatic cancer. The spread of carcinoma to lymph nodes or to bone is detected with greater frequency by radioimmunoassay than by the enzymic test. Radioimmunoassay also detected metastasis to the bone more frequently than did physical methods. Analytical and clinical performance of the four methods is described.

Acid Phosphatase↗
PubMed1981

An immunofluorescence assay for complement activation by the classical pathway.

The functional integrity of classical complement pathway components was determined by an immunofluorescence (IFL) assay based on the capacity of cytoskeletal intermediate filaments (IMF) to bind C1q and to activate the complement pathway. The assay uses IMF-rich capillary endothelium of human term placentae as complement-activating substrate. IFL staining for bound C1q, C4 and C3 was demonstrated after incubation of the tissue sections with normal human sera in dilutions up to 1 : 80. Known inhibitors of C1q binding and inhibitors fo C3 convertase formation prevented binding of complement components. Eight of 100 sera from patients showed negative or reduced binding of complement whereas all of 100 control sera from healthy individuals were positive in the assay. Four negative patients' sera were studied further: 3 had markedly reduced hemolytic activity and normal levels of C3 and C4. The IFL assay for complement activation provides a simple method of evaluating complement deficiencies and of studying mechanisms and inhibitors of complement activation.

Autoantibodies↗
PubMed1981

Antibodies against polyriboadenylic acid in systemic lupus erythematosus and rheumatoid arthritis demonstrated by ELISA. Prevalence of and relation to antibodies against DNA and extractable nuclear antigens.

An enzyme-linked immunosorbent assay (ELISA) for the demonstration of class-specific antibodies against polyriboadenylic acid (poly-(A)) is described. The results revealed the presence of IgG-anti-poly(A) antibodies in 63% (22/35) of patients with systemic lupus erythematosus (SLE) and in 25% (22/88) of patients with rheumatoid arthritis (RA), the mean antibody level being significantly higher in the SLE patients. Anti-poly(A) antibodies of IgM class were seen in 15 and 17% of the patients, respectively. The prevalence of anti-poly(A) and anti-ssDNA antibodies of IgG class was similar in the patients with SLE, but the occurrence of antibodies against poly(A), DNA and extractable nuclear antigens varied independently of each other. In the RA-patients, a positive correlation was seen between the levels of IgG-anti-ssDNA and IgG-anti-poly(A) antibodies.

Adolescent↗
PubMed1981

Binding of C1q and complement activation by vascular endothelium.

Exposure of intermediate filaments of cultured cells to serum leads to antibody-independent binding of complement (C) component C1q, C4, and C3. The apparent C-activating property of cytoskeletal intermediate filaments was examined on a tissue level in The present study by using frozen sections of human kidney and term placentas as targets. The assay used fresh human serum or isolated C1q as sources of C and the bound C components were demonstrated by fluorescent conjugates against C1q, C4, and C3. A consistent finding was that the endothelium of vessel walls had the capacity to bind both C1q and C components C4 and C3. Less intense binding of C to vascular smooth muscle was noted. Binding of C1q was very rapid, taking place within 10 sec. Subsequently, accumulation of C4 and C3 was seen. Subsequently, accumulation of C4 and C3 was seen. Upon prolonged incubation, a decrease in demonstrable C1q and C4 was observed. Unfixed vascular endothelium bound both isolated C1q and C1q of EDTA- or enzyme inhibitor-treated serum. However, if unfixed, the binding structures appeared to be destroyed in the process of C activation. They were also readily destroyed by trypsin. The described observations seem to suggest a possible mechanism whereby C components may become deposited in vessel walls independently of antibodies.

Binding, Competitive↗