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Biomedical subjects

K Bergh

Publications and source records attributed to K Bergh.

48 records · Page 3Linked to original sources
PubMed1992

Production of monoclonal antibodies against the human anaphylatoxin C5a des Arg and their application in the neoepitope-specific sandwich-ELISA for the quantification of C5a des Arg in plasma.

A panel of ten murine monoclonal antibodies (MAbs) was raised against the human anaphylatoxin C5a des Arg. The MAbs were shown to abrogate or significantly inhibit the chemotactic activity in zymosan activated serum. MAb 4A2E10E2 and MAb 3G3C4 were used as capture and detecting antibody, respectively, in a sandwich enzyme-linked immunosorbent assay (ELISA) for the quantification of C5a des Arg. This ELISA was shown to be very sensitive (detection limit 20 pg/ml) and could be applied directly to plasma/serum samples. The lack of interference by plasma components, in particular C5, suggested specificity for an epitope on C5a (des Arg) which is concealed in native C5 and exposed on the activation fragment only, i.e., a 'neoepitope'. The mean C5a des Arg level in EDTA-plasma from 25 healthy individuals assessed at a 1/20 dilution was 11.2 ng/ml (SD 3.4; range 6.4-16.8 ng/ml). The applicability of the assay was investigated in patients treated with haemodialysis using different membranes. Markedly elevated plasma levels of C5a des Arg were found in blood returning from the dialyzer following contact with cuprophane membranes.

Animals↗
PubMed1992

Acanthamoeba keratitis; report of the first Norwegian cases.

Two patients with therapy resistant keratitis are described. There were no predisposing diseases. Both patients had been using rigid contact lenses for more than 10 years and both cleaned their lenses in cold tap water. The patients presented with keratitis of several weeks duration resistant to antibacterial and antiviral treatment and not responding to high doses of corticosteroids. Ultimately, after the possibility of a protozoan aetiology had been considered, culture of corneal scrapings from both patients yielded growth of Acanthamoeba trophozoites. Acanthamoeba keratitis is very rare in northern European countries and has never before been diagnosed in Norway. The present cases show that Acanthamoeba should be added to the list of possible pathogenic agents even in northern low temperature areas.

Acanthamoeba Keratitis↗
PubMed1991

Complement activation and pulmonary dysfunction in experimental Escherichia coli septicaemia.

Septicaemia was induced in anaesthetized and artificially ventilated rabbits. Three groups receiving different doses of Escherichia coli 055:B5 and a control group were studied. The animals were followed for 240 min after the start of the bacterial infusion. One animal in the high-dose and one in the medium-dose group died. Septic shock developed in the high-dose group. The infusion of E. coli led to a severe, sustained neutropenia and a dose-dependent thrombocytopenia. A severe arterial hypoxaemia developed during the infusion of bacteria in three of four animals, and in one of three animals in the high- and medium-dose groups, respectively. Both the levels of C5a in plasma and the accumulation of granulocytes in the lung tissue, as assessed by a morphometric method, were dependent on the dose of bacteria. A strong positive correlation was found between levels of C5a and endotoxin. The levels of both C5a and endotoxin correlated positively to the degree of accumulation of granulocytes in the lung tissue. The results from the present study suggest that the magnitude of bacteraemia and the degree of complement activation are probably important factors determining the course and the severity of septicaemia.

Animals↗
PubMed1991

Interference by anti-C5a monoclonal antibodies with the binding of C5a to cellular receptors and the induction of enzyme release from granulocytes.

A sandwich ELISA based on monoclonal antibodies (MAb) for the quantification of rabbit C5a is only modestly influenced by the presence of MAb 4A3A9, which reacts with an epitope on C5a different from those of MAbs used in the sandwich ELISA. Incubation of rabbit or human granulocytes with C5a in the presence of MAb 4A3A9 results in a less pronounced decrease of the C5a concentration as compared to the concentration measured in the absence of MAb. We interpret the results to indicate an interference of MAb 4A3A9 with the binding of C5a to and/or the dissociation of C5a from its cellular receptor. MAb 4A3A9 is the least effective (25.4% inhibition) among anti-C5a MAbs in inhibiting C5a-induced beta-glucuronidase release from neutrophils. Together, these findings may indicate that a C5a-MAb complex is still able to induce a C5a effect even if MAb does interfere with the binding of ligand to the receptor.

Animals↗
PubMed1990

The psoriasis-associated antigen, pso p27, participates in the formation of complement activating immune-complexes in psoriatic scale.

The psoriasis-associated antigen, pso p27, and antibodies recognizing this antigen were demonstrated in extracts from psoriatic scales. It was demonstrated that the antigen was present in complexes containing IgG as well as complement factor C1q. The complexes were studied with respect to complement-activating potential. This was measured as the ability of the complexes to induce the generation of the complement factor C5a using rabbit serum as the source of complement. The data obtained showed that the pso p27-containing complexes were able to activate the complement system, indicating that the pso p27 antigen may contribute to the inflammatory process in psoriasis.

Animals↗
PubMed1989

Measurement of complement activation in rabbit plasma or serum using monoclonal antibodies against C5a.

Eight murine monoclonal antibodies (MoAb) raised against the major zymosan-induced chemotactic factor in rabbit serum were found to neutralize the chemotactic activity induced by lipopolysaccharides (LPS) and antigen-antibody complexes. A 15 kDa antigen was identified in plasma incubated with LPS by immunoblot analysis with MoAb. This is similar to the molecular weight of the major zymosan-induced chemotactic factor. Both the generation of this 15 kDa antigen and chemotactic activity were abrogated in a heat-inactivated plasma. A cross-reaction to human C5a was demonstrated for three MoAb (5H8B9, 4B1C11, and 2A5E3) in an indirect enzyme-linked immunosorbent assay (ELISA) of partially purified C5a and by the isolation of zymosan-induced chemotactic activity by affinity chromatography. MoAb 5H8B9 and 4B1C11 were able to neutralize the chemotactic activity in human zymosan-activated serum. MoAb 2A5E3 was able to bind 125I-labelled human C5a des Arg. We conclude that these MoAb are directed against rabbit C5a. MoAb 5B2C5 and 2B1A2, which are directed to different antigenic binding sites on C5a, may be applied in a sandwich ELISA for the detection and quantification of C5a des Arg in rabbit serum or plasma. The sandwich ELISA can be performed directly on serum or plasma samples without having to precipitate native C5. Complement activation is demonstrated by measuring the increased generation of C5a des Arg in rabbit plasma or serum activated with LPS, zymosan, antigen-antibody complexes, or cobra venom factor.

Animals↗
PubMed1988

Monoclonal antibodies against the major zymosan-induced chemotactic factor in rabbit serum.

The major zymosan-induced chemotactic factor in rabbit serum was purified by a two-step ion exchange chromatography procedure. The purified chemoattractant was used as antigen for production of murine monoclonal antibodies against the major chemotactic factor. The primary screening of the hybridoma cultures was an indirect ELISA using purified chemotactic factor as antigen. The final selection among ELISA-positive clones was performed according to the results obtained in a chemotactic inhibition assay. Six monoclonal antibodies were raised. These antibodies completely abrogated or substantially reduced the chemotactic activity in crude zymosan-activated serum. The chemotactic factor(s) could be absorbed onto an immunosorbent column containing monoclonal antibody and subsequently be specifically eluted with acid. By Western blot analysis the molecular weight of the major chemotactic factor was estimated to be approximately 15,000, and isoelectric focusing indicated a pI of about 9.4.

Animals↗
PubMed1986

Same-day confirmation of Staphylococcus aureus bacteraemia by a thermonuclease test.

A test to detect thermostable DNase activity (TDNase test) was evaluated for rapid confirmation of S. aureus bacteraemia, using toluidine blue O DNA agar plates for the testing. A total of 226 blood cultures which grew bacteria were examined. S. aureus was identified in 76 of the cultures. All of the S. aureus isolates showed positive TDNase test after 2 h of incubation of the test plates. The remaining isolates examined, most of them coagulase-negative staphylococci, showed a negative test. The TDNase test enables reliable same-day confirmation of S. aureus bacteraemia.

Humans↗
PubMed1983

The pharmacokinetics and diuretic effects of piretanide in chronic renal insufficiency.

The pharmacokinetics of piretanide, a new loop diuretic, were studied in four patients with GFR 4.7-14.8 ml/min. An oral dose of piretanide 18 mg was given at 08.00 h in two patients and at 08.00 h and 14.00 h in two. Blood samples were drawn after 0.5, 1, 2, 3, 4, 6, 8, 10, 12 and 24 h. Serum concentrations of piretanide were estimated by radioimmunoassay. The peak serum concentration of piretanide (1-2 h after drug administration) was 510-880 ng/ml, independent of renal function. Elimination half life (t1/2) was 1.2-4.1 h, area under the curves (AUC(0,24)) 1.63-2.44 micrograms ml-1 h, volume of distribution (Vz) 0.30--0.741#kg, total plasma clearance (CL) 122.8-184.0 ml/min and renal clearance (CLR) 1.5-5.2 ml/min. The clinical effects of oral treatment with piretanide 18 mg twice daily were compared with bumetanide 3 mg twice daily in eight patients with renal failure (GFR 2.2-24.5 ml/min). Both drugs equally increased the 24 h output of urine (delta V), sodium (delta UNaV), chloride (delta UC1V), potassium (delta UKV) and calcium (delta UCaV). Fractional excretion of sodium (ENa%) was doubled by piretanide in patients with GFR less than 8 ml/min while a five fold increase was found in patients with GFR greater than 8 ml/min. The onset of effect was the same for both drugs, but the duration exceeded 6 h only for piretanide. Both drugs were most effective on the first of two consecutive treatment days. Delta UC1V was always greater than delta UNaV and urinary phosphate excretion was unchanged, as expected of a loop diuretic without significant proximal effects. Metabolic or clinical side effects were not noticed.

Bumetanide↗