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Biomedical subjects

O Grimmer

Publications and source records attributed to O Grimmer.

18 recordsLinked to original sources

Biological equilibration of allergen preparations: methodological aspects and reproducibility.

A method for biological equilibration (BE) of allergen reference preparations using the skin-prick test (SPT) method and histamine HCl 10 mg/ml as reference substance (reference method), was evaluated. The precision was low for weals less than 10 mm2. The slope (log weal area/log concentration) of allergen and histamine did not vary significantly between investigators and allergens. The median slopes were 0.39 (n = 384) and 0.34 (n = 397), for allergen and histamine, respectively (P less than 0.01). The concentration of allergen eliciting a weal of the same size as that of histamine HCl 1 mg/ml (Chl) in the median sensitive patient, 1000 Biological Units/ml (BU/ml), did not vary significantly between clinics/geographical regions (grasses, mites and moulds). As BE is repeatable between regions, BUs estimated by this method are generally valid. A high correlation (r = 0.91, P less than 0.001) was found between the median Chl as estimated with histamine 1 and 10 mg/ml as reference substance, respectively. Thus, this reference method for BE is valid. The precision of the SPT method with histamine HCl 1 mg/ml is not as good as with 10 mg/ml, which is therefore recommended as the reference concentration.

Adolescent↗

Results of biological standardization with standardized allergen preparations.

The aim of biological standardization (BS) is to equilibrate the activity (potency) of allergen extracts from different source materials. This was done by performing skin prick tests (SPT) on patients who were sensitive to one of the following 10 allergens: Birch, alder, hazel, timothy, rye grass, velvet grass, cultivated rye, mugwort, D. farinae and Cladosporium herbarum. Patient sensitivity varied within a range of three to four powers of ten for each allergen investigated. The weal size in each patient corresponding to that elicited by histamine 1 mg/ml was calculated using the model log (mean weal diameter) = a + b log (concentration). The correlation coefficients of the regression lines of the allergen dose response relationship were found to be greater than 0.85 in most cases. The median slope for all extracts was 0.24. The slope for Cladosporium was significantly steeper than that for pollens. The amount of material in microgram dry weight (d.w./ml) equal to 1000 biological units/ml (BU/ml) varied within a factor of three between species for all tested purified allergen preparations but Cladosporium. For Cladosporium, about 30 times more material was needed than for D. farinae. When using crude rather than purified material, it was necessary to use five to ten times more to elicit a reaction corresponding to 1000 BU/ml, but the difference was significant only for Cladosporium. The narrow range of allergen concentrations used by us as well as other investigators does not assure positive skin prick test results in all patients with clinical symptoms due to the allergen in question. Skin prick testing should therefore be done over a wide range of concentrations to improve the methods for BS.

Allergens↗

Characterization of the carbohydrate moiety in a partly purified allergen preparation from the mould Cladosporium herbarum and its possible importance for allergenic activity as tested by RAST-inhibition.

The monosaccharide composition of a partly purified Cladosporium herbarum allergen preparation was found to be mannose, galactose and glucose in the ratio 1:1:0.8. The carbohydrate part of the preparation was quantified to 55% of the dry weight material by means of methanolysis and gas liquid chromatography (GLC) of trimethylsilylated methyl glycosides. The protein content was found to be 25%, determined by the Lowry method. Methylation analysis and periodate oxidation indicated that the main part of the carbohydrate moiety consists of galactomannans and glucans. It is suggested that the galactomannan is a highly branched polymer with mannopyranose units, 1,2- and 1,6-linked in the main chain, having shorter chains of 1,6-linked galactofuranosyl units linked through position 3 of the 1,6-linked mannopyranose units. The glucan part is probably a mixture of several polymers consisting of 1,3-linked and 1,4-linked glucans. The radioallergosorbent test (RAST) inhibition showed a lower IgE binding capacity for periodate-treated mould preparations, in which sugars containing vicinal diols had been oxidized, suggesting that the carbohydrate moiety may be of importance in IgE binding reaction of allergens. Periodate oxidation did not seem to alter the amino acid composition of the protein.

Acetylglucosamine↗

Clinical effects of hyposensitization using a purified allergen preparation from Timothy pollen as compared to crude aqueous extracts from Timothy pollen and a four-grass pollen mixture respectively.

Most extracts used in hyposensitization are complex and ill-defined mixtures of a large number of antigenic components. A highly refined (purified) and well-characterized allergen preparation from Timothy pollen (Phleum pratense) is now available. This paper describes the results of hyposensitization for 3 years comparing the purified preparation Timothy N, the crude extract Timothy O and a four-grass mix in sixty patients with allergic rhinitis due to grass pollen. The sixty patients were randomized into three groups and compared with a control group not hyposensitized. All three groups showed a significant decrease in clinical symptoms compared with the control group. The Timothy N group had a significantly higher nasal tolerance shown by nasal challenge test after 3 years' treatment than the group treated with the crude extract (P = 0.05). In addition, the Timothy-N-treated patients needed significantly less antihistaminic medication than the patients having received the crude extract or the four-grass mix (P = 0.02 and P = 0.01, respectively).

Adult↗

Characterization of the mouse and rat IgE antibody responses to timothy pollen by means of crossed radioimmunoelectrophoresis.

The IgE antibody responses to timothy pollen allergens in one rat strain and five mouse strains were investigated by means of crossed radioimmunoelectrophoresis. The rodent strains were selected for their capacity to respond with IgE antibody production. When sensitized parenterally with the antigen mixed in alum, the animals produced IgE antibodies to essentially the same antigens in timothy pollen as timothy sensitive patients have been shown to do. Thus, the allergenicity of the complex mixture of antigens in a timothy extract is similarly expressed in animals immunized parenterally with alum as in patients sensitized by inhalation.

Animals↗

Characterization of the carbohydrate moiety in a purified allergen preparation from the mite Dermatophagoides farinae and its importance for allergenic activity as tested by rast-inhibition method.

The monosaccharide composition of a purified mite allergen preparation was mainly found to be: mannose, galactose, glucose, N-acetylglucosamine and N-acetylgalactosamine quantitated to 15% of dry material by means of methanolysis and GLC of trimethylsilylated methyl glycosides. Protein content was found to be 65%, determined by the Lowry method. Methylation analysis and periodate oxidation indicated the main polysaccharide material to be built of 1,6-linked hexosamine, with side chains having mainly galactose end groups. Attempts to obtain separate carbohydrate fractions by ion exchange chromatography of the extract on CM-Sephadex and DEAE-Sephadex columns were not successful. The RAST-inhibition test showed a lower IgE binding capacity for periodate-treated mite preparation, where sugars containing vicinal diols have been oxidized, compared to an untreated mite preparation.

Allergens↗

Hyposensitization. Comparing a purified (refined) allergen preparation and a crude aqueous extract from timothy pollen.

Most extracts used in hyposensitization (immunotherapy) are complex and ill-defined mixtures of a large number of non-antigenic and antigenic components, only a few of the latter being of significance for allergy and allergen specific immunotherapy. A new purified and well-characterized allergen preparation from timothy pollen is now available, and it has been shown to be superior to the corresponding crude aqueous extract in the diagnosis of IgE-mediated human allergy to timothy pollen. This paper describes the results of hyposensitization for 2 years, with the purified preparation and the crude extract compared. The changes in in vivo and in vitro tests following this treatment in 40 patients with allergic rhinitis due to grass pollen are reported. Both patient groups showed a significant decrease in clinical symptom scores when compared with a control group during the grass pollen season. For all groups the symptom scores correlated well with atmospheric pollen counts. Nasal challenge tests showed a significant increase in nasal tolerance to timothy pollen after 2 years of treatment, but nasal tolerance was unchanged in the control group. Nasal function as a criterion for evaluating the effect of specific hyposensitization is discussed. Serum concentrations of timothy pollen-specific IgE antibodies showed a significant decrease for the group treated with the purified preparation and a slighter and non-significant reduction for the other treated group. There was no significant change in total serum IgE levels. The results indicate that the purified preparation is preferable to the crude aqueous extract in hyposensitization.

Adult↗

Immediate type hypersensitivity to common moulds. Comparison of different diagnostic materials.

Extracts of five common atmospheric moulds (Alternaria, Aspergillus, Cladosporium, Mucor and Penicillium) obtained from different manufacturers were compared by means of skin prick testing and, partly, with the radioallergosorbent test. Considerable differences were found between the extracts with respect to positive tests found in mould-allergic individuals and controls. A purified allergen preparation of Cladosporium herbarum was superior to the crude allergen extracts. The results suggest that the allergen contents of the extract differed both with respect to total allergenic potency and to allergenic composition.

Adolescent↗

Increased serum IgE in Hodgkin's disease is of polyclonal origin.

The light chain of serum IgE from 4 untreated patients with Hodgkin's disease with elevated IgE levels was studied by an immunoadsorbent technique. Serum IgE was found to contain both kappa and lambda light chains in all cases studied. In addition an association between serum levels of IgE and that of IgA, IgG, and IgM was demonstrated. These findings make it unlikely that increased serum IgE in Hodgkin's disease is of monoclonal origin and support the view that serum IgE in such patients reflects a general disturbance in the regulation of their humoral immune response.

Adult↗

Demonstration of distinct allergens by means of immunological methods. Comparison of crossed radioimmunoelectrophoresis, radioallergosorbent test and in vivo passive transfer test.

An immunosorbent column was prepared containing a purified major allergen fraction from codfish (DS 22) covalently coupled to agarose. Sera from patients allergic to codfish were run through the column at pH 7.2. After extensive washing, the IgE retarded in the column was eluted with a buffer at pH2.5. The original sera and fractions from the chromatography experiments were examined by means of crossed immunoelectrophoresis (CIE), crossed radioimmunoelectrophoresis (CRIE), radioallergosorbent test (RAST) and in vivo passive transfer (PK) tests using the DS 22 from codfish and a crude codfish extract. The experiments demonstrated that the crude extract contained a minor codfish allergen (antigen-17-cod) which was distinct from DS 22. RAST was the most convenient technique for the identification of fractions containing allergenic activity. The PK tests served to prove the biological activity in vivo. CIE/CRIE were superior to RAST and PK tests regarding their ability to identify distinct allergens. Full agreement was found between results using different techniques including the immunosorbent experiments. Some of the radiostaining in CRIE, however, was misleading due to coprecipitation of DS 22 in several precipitates in the CIE preparations of the crude codfish extract.

Allergens↗

A new well-characterized, purified allergen preparation from timothy pollen. I. Chemical properties.

A purified allergen preparation, Timothy N, from timothy pollen (Phleum pratense) was characterized with respect to chemical properties in comparison with a commercially available crude extract, Timothy O, from the same pollen material. In Timothy N about 94% of the protein and 99% of both hexoses and pentoses were removed during the purification. Timothy N contains a limited number of proteins with molecular weights of about 15,000 and 30,000. A Timothy N solution of 0.010 mg/ml will have an allergenic activity of 1 HEP.

Allergens↗

A new well-characterized, purified allergen preparation from timothy pollen. II. Allergenic in vivo and vitro properties.

A purified allergen preparation, Timothy N, from timothy pollen and a crude commercial extract, Timothy O, prepared from the same pollen material, were tested in tenfold dilutions on 59 adults with allergic rhinitis and on 29 children with bronchial asthma. All patients were allergic to grass pollen. Using the prick and intracutaneous methods, dose-response tablets were established for the two preparations showing a good correlation. Nasal provocation tests on the adult patients and bronchial provocation tests on the children gave positive reactions in all cases when using Timothy N. No irritant effect resulting in non specific reactions were elicited. The availability of stable, freeze-dried and purified allergen preparations supplied in different vials with defined allergenic activities fulfils the clinical demands for a modern diagnostic allergen preparation.

Adolescent↗

A new well-characterized, purified allergen preparation from timothy pollen. III. Immunological properties in the human immunoglobulin E system.

The following methods were used in vitro to characterize and quantitate the allergenic activity of a purified allergen preparation, Timothy N, from timothy pollen: radioallergosorbent test (RAST), direct-titration RAST and RAST inhibition. Vials containing freeze-dried and standardized quantities of this preparation showed good uniformity and accuracy with regard to the allergenic activity. The stability of the preparation in solution and in the freeze-dried state was tested by RAST inhibition and was found to be acceptable. Using the same method, the allergenic activity of Timothy N was compared to the allergenic activity of a crude extract, Timothy O, indicating a discrepancy which was not observed in vivo.

Allergens↗

Immunoelectrophoretic quantitation of antithrombin III. Electroimmunodiffusion in agarose gels containing heparin.

Antithrombin III (AT-III), being an alpha2-globulin, will have an electrophoretic mobility in the presence of heparin like prealbumin in agarose gels. This phenomenon was utilized to quantitate AT-III from serum and plasma by electroimmunodiffusion (EID) for 90 min agarose gels containing 75 USP units of heparin/ml gel. The method permits a rapid quantitation of AT-III from serum, citrated plasma and EDTA plasma, and a positive correlation was observed between these values and those obtained by single radial immunodiffusion (SRI). This is in contrast to quantitation of AT-III by EID in gels containing no heparin where the values for plasma showed poor correlation with those obtained by SRI.

Antithrombins↗