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Biomedical subjects

I Clemmensen

Publications and source records attributed to I Clemmensen.

At least 91 records · Page 5Linked to original sources
PubMed1981

Clumping of Staphylococcus aureus by human fibronectin.

Clumping of different staphylococci by fibronectin and other purified plasma proteins has been investigated. Purified fibronectin was capable of clumping Staphylococcus aureus strains in concentrations identical with concentrations of fibronectin in human plasma. S. epidermidis and S saprophyticus were not clumped by fibronectin. The binding of fibronectin to S. aureus was not mediated by protein-A, as a strain lacking protein-A clumped in the presence of fibronectin, and the presence of IgG could not inhibit the clumping of S. aureus strains. The fibronectin-binding component on the staphylococcal cell wall seems to be unrelated to the fibrinogen-binding clumping factor.

Agglutination↗
PubMed1980

Partial purification and characterization of a new fast-acting plasmin inhibitor from human platelets. Evidence for non-identity with the known plasma proteinase inhibitors.

An inhibitor of the plasma proteinase plasmin (EC 3.4.21.7) was partially purified from washed and lysed human blood platelets by (NH4)2SO4 fractionation and affinity chromatrography on Sepharose-linked purified plasminogen. The material contained none of the known plasma proteinase inhibitors when studied by crossed-immunoelectrophoresis and electroimmunoassay, but inhibited a clot-lysis-time assay and an esterolytic assay that used the synthetic substrate S-2251 (D-Val-Leu-Lys-p-nitroanilide). The inhibitory activity had the same mobility as the alpha 2-plasma proteins on preparative agarose-gel electrophoresis. Titration of the inhibitor preparation by active-site-titrated plasmin demonstrated a dissociation constant of approx. 0.1 nM. The inhibition was complete within 1 min. The inhibitor increased the mobility in agarose-gel electrophoresis of purified activator-free plasmin or 125I-labelled plasmin, as demonstrated by crossed-immunoelectrophoresis against specific immunoglobulins against plasminogen or by radioautography. The results strongly suggest the presence in platelets of a plasmin inhibitor different from the known plasma proteinase inhibitors.

Blood Platelets↗
PubMed1980

[Fibronectin].

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Fibronectins↗
PubMed1980

Immunoglobulins and albumin in sputum from patients with cystic fibrosis. A study of protein stability and presence of proteases.

Sputum sol phase from seventeen cystic fibrosis (CF) patients chronically infected in the lungs with mucoid Pseudomonas aeruginosa and presenting multiple precipitins in serum against this bacterium (CF + P) and 11 CF patients without P. aeruginosa infection (CF-P) were examined for proteolytic activity in a fibrin plate assay. The proteolytic activity was significantly higher (p smaller than 0.02) in sputum from CF + P patients than in sputum from CF-patients. This difference was only quantitative since sputum sol phase from both groups degraded fibrinogen to non-precipitable material. The proteolytic degradation of IgG, IgA, secretory IgA and albumin in the sputum sol phases was investigated by means of gel filtration and the stability of these proteins during various storage conditions was examined. Degradation of IgG, IgA, secretory IgA and albumin in the sputa was not demonstrable and the proteins were stable for at least 4 weeks at 4 degree C.

Adolescent↗
PubMed1980

Fibrinogen Copenhagen; an abnormal fibrinogen with defective polymerization and release of fibrinopeptide A, but normal adsorption of plasminogen.

A qualitatively abnormal fibrinogen was detected in the plasma of a 53 year old woman with severe arterial thrombotic disease. The concentrations of plasma fibrinogen and serum fibrinogen related material were normal. The abnormal fibrinogen was electrophoretically normal. The defects detected were an abnormality of polymerization of fibrin monomers and a decreased rate of release of fibrinopeptide A. The absorption of radiolabelled partially degraded plasminogen on to fibrin prepared from purified fibrinogen Copenhagen was normal.

Adsorption↗
PubMed1979

The extra-articular deposition of fibrinogen antigenic material in patients with rheumatoid arthritis.

Experimental suction blisters were elicited on extensor and flexor sites or forearm skin of patients both with rheumatoid arthritis and without rheumatoid diseases. The blister fluid obtained was investigated, together with rheumatoid bursa fluid and rheumatoid noduli material by crossed and quantitative immunoelectrophoresis for fibrinogen antigenic material, plasminogen and inhibitors of fibrinolysis. In rheumatoid noduli and rheumatoid bursa fluid, fibrinogen degradation products identical with those previously described in rheumatoid synovial fluid and in bullous dermatosis were found (3, 14). On the other hand, no fibrinogen antigenic material was found in the experimental suction blisters. These results indicate that the fibrinogen degradation products in rheumatoid inflammatory exudate are probably not specific for a rheumatoid process, but rather part of a general mechanism in inflammation.

Adult↗
PubMed1979

Fibrinogen/fibrin degradation products in exudates from bullous dematoses.

Inflammatory exudates from 10 patients with bullous skin diseases were analysed by immunochemical techniques including crossed immunoelectrophoresis. The results were compared with those obtained in fluid from suction bullae obtained in normal skin in 13 control subjects and synovial fluid from 20 patients with rheumatoid arthritis. Abnormal fibrinogen degradation products identical with those found in synovial fluid from patients with rheumatoid arthritis were detected in exudates from each of the patients with bullous dermatoses, whereas significantly smaller amounts of fibrinogen antigenic material were detected in fluid obtained by suction. The fibrinogen antigenic material demonstrated in exudates from pathological bullae, immunochemically similar to that found in rheumatoid synovial fluid, indicates that the presence of these products reflects the more general features of an inflammatory exudate.

Aged↗
PubMed1978

Purification and reaction mechanisms of the primary inhibitor of plasmin from human plasma.

The primary inhibitor of plasmin in human plasma was purified by a four-step procedure involving fractional (NH(4))(2)SO(4) precipitation, ion-exchange chromatography on a column of DEAE-Sepharose CL-6B and affinity chromatography on both a plasminogen-CH-Sepharose 4B column and a column of 6-aminohexanoic acid covalently coupled through the carboxylate function to AH-Sepharose 4B. No impurities in the final preparation could be detected when tested by immunoelectrophoresis against a range of specific antisera or against rabbit anti-human serum. On polyacrylamide-gel electrophoresis the inhibitor preparation showed a single band. The dissociation constant for the inhibitor-plasminogen complex was determined to be approx. 3mum at pH7.8. The reactions of the inhibitor with human plasmin and with bovine trypsin were studied. Comparison of the results obtained confirms the hypothesis previously presented, namely that the reaction of the inhibitor with plasmin involves at least two steps, the initial rapid formation of an enzyme-inhibitor complex followed by a slow irreversible transition to another complex. The results also indicate that the reaction of the inhibitor with trypsin involves just a single, irreversible step, so that this reaction seems to be less complicated than that of the inhibitor with plasmin. The ways in which 6-aminohexanoic acid influences the reactions were studied. The same value for the dissociation constant (approx. 26mum) for 6-aminohexanoic acid is obtained for both its effect on the reaction of the inhibitor with trypsin and for competitive inhibition of trypsin. The inhibitory effect of 6-aminohexanoic acid thus seems to be due to its blocking of the active site of trypsin. In contrast with this, the inhibitory effects of l-lysine and 6-aminohexanoic acid on the inhibitor-plasmin reaction occur at concentrations much too low to affect the active site of plasmin. The possible dependence of the reaction of the inhibitor with plasmin on a second site(s) on plasmin is discussed.

Aminocaproic Acid↗
PubMed1978

Inhibition of urokinase by complex formation with human antithrombin III in absence and presence of heparin.

Human antithrombin III was purified from fresh human plasma by affinity chromatography on heparin-Sepharose, affinity chromatography on concanavalin A Sepharose, gel filtration on Ultrogel AcA 34, ion exchange chromatography on DEAE A-50 Sephadex and preparative agarose gel electrophoresis. The hydrolytic activity of urokinase (plasminogen activator from urine) on acetyl-glycyl-L-lysine methylester acetate (Ac-gly-lys-OMeAc) was inhibited by antithrombin III in a slow time-dependent manner. Heparin accelerated the reaction between activator and inhibitor. Inhibition of catalytic activity was associated with the formation of an 1:1 molar complex between activator and inhibitor as revealed by sodium dodecyl sulphate polyacrylamide gel electrophoresis. The complex was also demonstrated by crossed immunoelectrophoresis against anti-antithrombin III.

Antigen-Antibody Complex↗
PubMed1978

Properties of fibrinogen-antigenic material on the rheumatoid synovial membrane and in the rheumatoid synovial fluid.

Fibrin deposits on rheumatoid synovial membranes and fibrinogen-antigenic material in rheumatoid synovial fluid were found to be identical by crossed immunoelectrophoresis into immunoglobulin against fibrinogen, by SDS-polyacrylamide gel electrophoresis, and by gel filtration on Sepharose CL 6B. The material was found to be neither fibrinogen nor fibrin, but degradation products. One of the fragments was purified by preparative agarose electrophoresis, and the physicochemical properties of this fragment were found to be different from those obtained by plasmin digestion of fibrinogen or fibrin. This indicates that other proteases than plasmin are responsible for the degradation products. The material was easily degraded by plasmin to D- and E-antigenic end products, identical to those obtained by plasmin digest of fibrinogen. The solubility of the material was poor in synovial fluid compared to serum and buffer. On the basis of these results, it is suggested that the fibrinlike material on the synovial membrane represents fibrinogen degradation products from the inflamed tissue. These products are likely released into the synovial fluid, and when their concentration here exceeds their solubility, they precipitate on the synovial membrane.

Arthritis, Rheumatoid↗
PubMed1977

Kinetic properties of the primary inhibitor of plasmin from human plasma.

The interaction of human plasmin with the newly discovered alpha2-plasmin inhibitor was investigated. It was found from rate measurements that the reaction involves the rapid formation of a first enzyme-inhibitor complex, followed by the slow irreversible transition to another complex. L-Lysine influences the first step, but not the second.

Fibrinolysin↗