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Biomedical subjects

H Elwing

Publications and source records attributed to H Elwing.

64 records · Page 4Linked to original sources
PubMed1980

Determination of rheumatoid factor by means of thin layer immunoassay.

Thin layer immunoassay (TIA), a solid phase immunoassay based on a technically simple visualization method, was adapted for quantitative determination of rheumatoid factor (RF) in blood serum. The influence of various factors of possible significance for accurate quantitation of RF by TIA was studied. Comparison between TIA and the Waaler-Rose test for determination of RF was performed on 335 patient sera. The results obtained by the two methods agreed reasonably well. Preliminary experiments were also performed concerning the use of TIA for differentiation of RF with regard to the immunoglobulin class. It is concluded that, because of its simplicity and screening capacity, TIA could be an attractive method for detection and quantiation of RF.

Antigen-Antibody Reactions↗
PubMed1980

Application of thin layer immunoassay (TIA) for demonstration of antibodies against Entamoeba histolytica.

Thin layer immunoassay (TIA) was used to demonstrate antibodies against Entamoeba histolytica in sera from patients and blood donors. The TIA results agreed well with those obtained by the indirect hemagglutination (IHA) and immunodiffusion (ID) techniques. It is suggested that because of its technical simplicity and low cost TIA may be used alternatively or in addition to the IHA and ID techniques for screening patient sera for antibodies to E. histolytica. However, the new technique must first be evaluated on a goup of clinically well defined patients with different stages of amebiasis.

Amebiasis↗
PubMed1979

Diffusion in gel-enzyme linked immunosorbent assay (DIG-ELISA): a simple method for quantitation of class-specific antibodies.

A new method for quantifying class-specific antibodies is presented. The method has been named Diffusion-In-Gel-Enzyme-Linked-ImmunoSorbentAssay (DIG-ELISA), and is briefly as follows. Antiserum ia allowed to diffuse from wells in a gel layered over an antigen-coated plastic surface. The gel is then removed and the preparation is incubated with enzyme-conjugated anti-immunoglobulin. The enzyme is then visualised in situ by a colour reaction produced by pouring a substrate-containing gel over the plastic surface. Bovine serum albumin and rabbit-anti-BSA were used as a model system, and horseradish peroxidase or alkaline phosphatase as enzymes for visualization.

Alkaline Phosphatase↗
PubMed1979

Thin-layer immunoassay for determination of antibodies to herpes simplex virus.

Thin-layer immunoassay (TIA) is a simple serological technique suitable for analysis of large numbers of samples. In this study, TIA was evaluated for determination of antibodies to herpes simplex virus. Herpes simplex virus antigen used in TIA was purified from material released from virus-infected cells. The results obtained by TIA were compared with those obtained by neutralization and complement fixation tests. TIA was found to be as sensitive as the neutralization test for demonstration of herpes simplex virus antibodies. No false-negative or -positive reactions were observed. In primary herpes simplex virus-1 infections, an antibody response was demonstrated by TIA, whereas antibodies could not be demonstrated in patients with primary herpes simplex virus-2 infections.

Antibodies, Viral↗
PubMed1977

A simple spot technique for thin layer immunoassays (TIA) on plastic surfaces.

A simple and sensitive technique for visualization of antigen--antibody reactions is described. The property of many antigens to become adsorbed firmly on to a hydrophobic polystyrene surface while retaining their serological reactivity is taken advantage of. On a surface with adsorbed antigen the corresponding immune serum is applied spot-wise. The antigen--antibody reaction areas on the surface are characterized by a distinct hydrophilic condensation pattern when exposed to water vapour. The results obtained by the immunoassay technique described can be reproduced with great accuracy. The method is well suited for quantitative determination of a wide range of antigens as well as their corresponding antibodies. Antigen concentrations of 0.2--0.8 mg/l and antibody concentrations about 1 mg/l can be detected. By employing an antiimmunoglobulin serum subsequent to the primary antigen--antibody reaction, an increase in sensitivity can be obtained.

Animals↗
PubMed1977

The CEA concentration in duodenal fluid in patients with pancreatic disease.

The CEA concentration in duodenal fluid after secretin-CCK stimulation has been investigated in 16 patients with pancreatic disease (6 with pancreatic carcinoma and 10 with chronic pancreatitis), 9 with non-pancreatic disease, and 10 control subjects. The purpose was to study whether the determination of CEA in duodenal fluid during the secretin-CCK test can give any additional information for the diagnosis of pancreatic disease and for differentiation between pancreatitis and carcinoma. We found that high values of CEA in duodenal fluid do not necessarily indicate pancreatic carcinoma. Moreover, the level may be elevated in non-pancreatic disease.

Carcinoembryonic Antigen↗
PubMed1976

Visualization principles in thin-layer immunoassays (TIA) on plastic surfaces.

Macromolecules may adsorb firmly as a monolayer to plastic surfaces and still retain their property to react specifically with antibodies. In the present communication four different principles for visualization of such antigenantibody interactions on plastic surfaces are described. In addition, a diffusion-ingel method for quantitation of antibodies is presented. The described methods offer simple, sensitive and accurate means of assaying antigen-antibody reactions.

Animals↗
PubMedDate not supplied

Effects of Escherichia coli spheroplast formation on assays of H2 and adenosine triphosphate based ampicillin susceptibility tests.

The present study examined the effects of ampicillin on one strain of Escherichia coli in lactose peptone broth with an osmolality of 342 mosm/L under anaerobic conditions. Spheroplast formation occurred at 10 X MIC of ampicillin. The metabolic changes that took place during spheroplast formation disfavored the production of molecular hydrogen. The intracellular bacterial adenosine triphosphate (ATP) level remained normal or slightly elevated during spheroplast formation while viability (cfu/ml) decreased. Thus spheroplast formation did not interfere significantly with ampicillin susceptibility as interpreted by assaying molecular hydrogen and viability. The effect on the ATP assay was, however, pronounced. It was found that the reversion of spheroplasts to bacterial cells for this particular strain (as recorded by cfu/ml) did not occur in quantitative numbers. The ATP assay thus indicated an approximate of the density of cells, while viability studies reported a lower cell density. When using a broth with lower osmolality (50 mosm/L) no spheroplast formation occurred and a close relation between viability and intracellular ATP was observed.

Adenosine Triphosphate↗
PubMedDate not supplied

[Adsorption of fibrinogen on silicon oxide with controlled hydrophobic/hydrophilic properties].

The amount of fibrinogen irreversibly adsorbed on silicon dioxide does not exceed 3.6 pmol/cm2 and depends on the protein concentration, solution pH and surface hydrophobic/hydrophilic properties. Electrostatic interactions determine the fibrinogen adsorption rate. Partial denaturation of fibrinogen takes place in its adsorption form diluted solutions with the pH value lower than the protein isoelectric point.

Adsorption↗