Search PubMed⌕ Search

Biomedical subjects

R Einarsson

Publications and source records attributed to R Einarsson.

At least 55 records · Page 3Linked to original sources
PubMed1990

Immunoblotting analysis of concanavalin A-isolated allergens of Candida albicans.

The carbohydrate-containing fraction of Candida albicans was isolated from the crude extract with ConA Sepharose affinity chromatography and studied by IgE-immunoblotting with individual and pooled sera from C. albicans-allergic subjects. In the ConA-bound fraction there was a diffuse IgE binding in the high molecular weight area which also gave a carbohydrate stain (PAS). A distinct band corresponding to a molecular weight of 70 kD bound specific IgE antibodies. This glycoprotein, presumably a mannoprotein, gave a weak carbohydrate staining and a strong protein staining. Further biochemical studies are needed to reveal the exact nature of the epitopes in the ConA-bound mannose-containing fraction of C. albicans.

Allergens↗
PubMed1990

Preparation of allergen extracts from the green alga Chlorella. Studies of growth variation, batch variation, and partial purification.

Allergen extracts were prepared from different raw materials of three strains of the unicellular green alga Chlorella (C. vulgaris, C. homosphaera and C. saccharophila). Growth variation, batch variation and composition of partially purified extracts were studied by analyzing total protein and carbohydrate content, protein and IgE-binding patterns and allergenic potency. Chlorella allergens were produced in the same proportions in early and late exponential growth phases but appeared partly degraded in the stationary phase. Uniform growth and extraction from Chlorella cells in the late exponential phase were demonstrated. Partially purified extracts from cells in late exponential phase contained 50% protein of the dry weight compared to 20% in crude extracts. The carbohydrate content was 20-30% of the dry weight of both crude and purified extracts. The allergenic potency of the purified extracts was 150-340% of the crude extracts, as assayed by RAST inhibition. The purified C. vulgaris extract showed a reduced IgE binding compared to crude extracts, while C. homosphaera and C. saccharophila extracts exhibited consistent IgE binding and are therefore suitable for in vivo and in vitro studies of allergenic properties of Chlorella.

Allergens↗
PubMed1989

Detection of IgG4 antibodies by immunoblotting in patients on vespid venom immunotherapy.

A nitrocellulose immunoblotting procedure has been used to monitor patient specific IgG antibodies during Hymenoptera vespid venom therapy. By using monoclonal antibodies in the immunoblot assay the relative IgG4 antibody levels could be analysed semiquantitatively. Treatment with vespid venom over 2 years resulted in rises in venom-specific IgG4 antibodies mostly directed towards antigen 5, phospholipase A and hyaluronidase. The use of high quality monoclonal antibodies in immunoblotting assays offers an improvement in the in vitro evaluation of venom immunotherapy.

Animals↗
PubMed1989

The international collaborative study on the first international standard of birch (Betula verrucosa)-pollen extract.

A selected candidate international standard preparation of birch (Betula verrucosa)-pollen extract was studied together with other birch-pollen extracts in a multinational study involving 20 laboratories in 11 countries. The biologic activity of the extract had previously been demonstrated in quantitative skin prick testing. The study methods comprised RAST inhibition, histamine release, quantitative immunoelectrophoresis, isoelectric focusing, and other methods. The results from RAST inhibition were calculated as parallel-line assays with statistical tests for linearity and parallelism. Analysis of variance was applied to test the significance of differences between potency estimates. In all assay methods, the candidate standard could be used to assign relative potencies to other birch-pollen extracts. The candidate standard was adequately stable during 36 months of storage at or below 5 degrees C. On the basis of this study, the World Health Organization has established the preparation as the International Standard for birch-pollen extract with assigned units of 100,000 IU per ampule.

Binding, Competitive↗
PubMed1989

Specific IgE and IgG antibody responses in children to timothy pollen components during immunotherapy.

Fourteen children with timothy grass pollinosis were given immunotherapy (IT) for 3 years with a purified and characterized timothy grass pollen preparation or a crude aqueous timothy pollen extract. Crossed radioimmunoelectrophoresis (CRIE) showed that 75% of the children under 11 years of age developed new specificities of IgE antibodies against timothy antigens, in contrast to older children, where no development of IgE antibodies against new timothy antigens could be detected. IgE antibodies were only detected against antigens formerly known as allergens. Timothy-specific IgG antibodies increased in most children during hyposensitization against the major allergens Ag 19 and Ag 24/25 and several other IgE-binding timothy antigens.

Adolescent↗
PubMed1989

Allergenic variability of different strains of Candida albicans.

The allergenic variation of six Candida albicans strains was studied by immunoblotting with pooled sera from 20 C. albicans-RAST-positive subjects. The presence of a 46-kilodalton (kD) protein, the major allergen, and a 29-kD protein, an intermediate allergen, was shown in crude extracts from disrupted cells (six strains). There was a significant variation in the content of the major C. albicans allergen (46 kD) between the different strains. Surface extracts of all six C. albicans strains contained mannan. Immunoblotting of cell wall extracts of intact C. albicans (agar plate) of different age revealed the strongest IgE binding in cultures incubated for 36-50 h. Due to the varying proportions of allergens demonstrated in the different strains of C. albicans, the starting source material for extract production should be a pool of individual strains, which all should be analysed prior to pooling. Special attention should be paid to the selection of C. albicans strains, and a parameter such as the breakability of the strain should be considered.

Allergens↗
PubMed1989

Variability of allergenicity in eight strains of the green algal genus Chlorella.

Biochemical and immunological properties of allergen extracts from eight strains within four species of the unicellular green alga Chlorella were compared. The total protein and carbohydrate contents ranged from 13 to 29 and 18 to 47% of the dry weight, respectively. It was shown, both with RAST inhibition and immunoblotting, that Chlorella contain components which specifically bind to patient IgE antibodies. The relative allergen potency as assayed by RAST inhibition varied fivefold. Between seven and twenty IgE-binding components were identified in the various strains with molecular weights from 13 to 80 kD. Thus, the use of thoroughly characterized Chlorella strains is mandatory for preparation of relevant allergen extracts.

Allergens↗
PubMed1989

Immunotherapy with dog and cat allergen preparations in dog-sensitive and cat-sensitive asthmatics.

Standardized dog and cat allergen preparations with defined allergen composition were used for immunotherapy (IT) in dog-sensitive and/or cat-sensitive adult patients. Seventeen patients completed 1 year of IT. Eleven patients were treated with dog allergen, five with cat allergen, and one with both dog and cat allergen. The treatment was well tolerated, with increased subjective tolerance. After 3 months of IT there was a significant decrease in conjunctival (p less than .05) and skin sensitivity (p less than .05). Specific IgE decreased significantly within 1 year as assayed by RAST and IgE-crossed radioimmunoelectrophoresis. Specific IgG increased in all patients. The results indicate that IT with potent and standardized dog and cat allergens influence the sensitivity to these allergens.

Allergens↗
PubMed1988

Breed-specific dog-dandruff allergens.

Fifty-one patients with clinical history of dog allergy were skin prick tested with eight individual standardized dog breed-allergen preparations, one mixed breed-allergen preparation (Poodle/Alsatian), dog-serum albumin, and histamine hydrochloride, 1 mg/ml. All extracts were characterized by crossed immunoelectrophoresis and crossed radioimmunoelectrophoresis with a pool of sera from patients clinically sensitive to dog. The dog-breed extracts contained common antigens/allergens, as well as components represented only in one or two dog-breed extracts. The concentration corresponding 1000 BU/ml varied from 16 to 100 micrograms of protein per milliliter. The sensitivity of skin prick test was 67% to 88% for the various dog breed-allergen preparations, but only 18% for dog-serum albumin. Significant difference between the skin test response to different dog breed-allergen preparations indicating dog breed-specific allergens was obtained in 15% of the patients. There was no significant correlation between skin prick test results and symptoms related to a specific dog breed.

Adolescent↗
PubMed1988

In vitro studies of degradation of birch and timothy pollen allergen preparations by human duodenal juice.

The hydrolysis of birch and timothy pollen allergen preparations by duodenal juice from an adult volunteer was studied in vitro with the aid of rocket immunoelectrophoresis, radiorocket immunoelectrophoresis and RAST-inhibition. The results achieved with all methods were similar. The duodenal juice had the capacity to hydrolyse both the grass and tree pollen proteins, and after 30 min preincubation only 10% of the original birch and timothy allergenic activity remained. Heat treatment of the duodenal juice completely destroyed the proteolytic activity (i.e. no hydrolysis occurred) while protease inhibitors only marginally prevented the hydrolysis.

Adult↗
PubMed1987

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↗
PubMed1987

Immunotherapy to deciduous tree pollens: specific IgE and IgG antibody patterns.

Thirty-nine children with birch pollinosis were given immunotherapy (IT) for 3 years with a purified, characterized and biologically standardized pollen preparation made from either birch or a mixture of birch, alder and hazel. Levels of IgE antibodies against birch, alder and oak increased early during IT (P less than 0.01) and then decreased below the initial level (P less than 0.01). Birch-specific IgG antibodies also increased (P less than 0.01) but not as rapidly as birch-specific IgE antibodies and the levels remained increased throughout IT. There were only weak correlations between immunochemical findings before IT or during early IT on one hand and the improvement during IT on the other hand. The ratio birch-specific IgG:IgE after 1.5 and 2.5 years of IT correlated with symptom scores the following season (P less than 0.01). In 60% of the children below 13 years of age, new IgE specificities developed during IT as demonstrated with crossed radioimmunoelectrophoresis. No such new IgE specificities were found in older children. These 'new sensitivities' did not appear to have any clinical implication.

Adolescent↗
PubMed1987

Selection of patients for biological standardization as exemplified by standardization of mugwort, goosefoot and English plantain pollen allergen extracts/preparations.

The biological activity of a partly purified, biochemically/immunochemically characterized mugwort pollen allergen preparation and crude pollen extracts of mugwort, goosefoot and English plantain was determined by means of skin prick test (SPT). The patient inclusion criteria with mugwort were a well-defined positive clinical history and a positive SPT. Symptoms related to goosefoot/English plantain pollens are difficult to define, as these weeds flower during the grass pollen season. Thus patients tested with these allergens did not fulfill the most important inclusion criterion for so-called biological standardization. To elicit a wheal of the same size as that produced by histamine 1 mg/ml required 100 to 10,000 times more material from these weeds, than from mugwort and other pollen allergen extracts investigated earlier. One thousand Biological Units/ml (BU/ml) corresponded to 8.3 micrograms dry weight (dw/ml) of the crude and 1.8 micrograms dw/ml of the purified mugwort pollen allergen preparation. Only 7/22 goosefoot-and English plantain-tested patients were positive at conjunctival or nasal challenge. All three weeds showed a similar composition with 5-10 allergens by CIE/CRIE analysis and 10-13 by immunoblotting analysis. One dominating allergen (approx. 15,000 d), could be identified for each weed species by protein gel blot after separation by SDS g-PAGE. There was no other explanation for the difference in biological activity than the criteria of selection. If there is no obvious clinical history, which is the main patient inclusion criterion in biological standardization, then additional criteria should be used.

Adolescent↗
PubMed1987

Detailed IgG and IgE antibody patterns during immunotherapy with honey bee venom.

Fourteen patients with a known honey bee venom (HBV) allergy were followed during 1-2 years of immunotherapy. HBV-specific IgG antibody levels increased in all patients but one. HBV-specific IgE antibodies decreased slightly during the first year of therapy. The ratio HBV-specific IgG-/IgE showed a marked increase during the first year for most of the patients, and a further increase during the second year in the four patients followed that long. As could be expected an increased radiostaining was found after 1 year of treatment to all important allergens in IgG CRIE, but after 2 years a sustained or increased radiostaining was obtained to phospholipase (PLA) alone. A decreased radiostaining might more easily be seen with weaker immunogens.

Adult↗
PubMed1987

Monitoring of antibodies in patients on immunotherapy with insect venoms by immunoblotting.

A rapid nitrocellulose immunoblotting procedure based upon electrophoretic transfer has been used to monitor patient specific IgE and IgG antibodies before and after specific Hymenoptera insect venom therapy. The patients followed a conventional schedule for immunotherapy with Pharmalgen bee and yellow jacket venoms. The allergenic profiles of the patients before and after treatment were qualitatively similar in many patients, but some showed decreased IgE binding after treatment. On the other hand, there was a significant increase in specific IgG antibodies directed towards phospholipase and hyaluronidase in the bee-venom-treated patients and towards antigen 5, phospholipase and hyaluronidase in the patients treated with yellow jacket venom. The immunoblotting is very useful for a rapid evaluation of patient specific antibody patterns without the prior isolation of allergens.

Antibodies↗
PubMed1987

Variability of antigenicity/allergenicity in different strains of Alternaria alternata.

Biochemical and immunological properties were studied in crude mould extracts from 10 different strains of Alternaria alternata. The mould strains were grown on completely synthetic medium and harvested under identical conditions. The biochemical and immunological analyses (protein content, carbohydrate content, IEF, RAST-inhibition, CIE/CRIE and the content of a major allergen) showed significant variations between the individual strains of A. alternata. 32 antigens were identified in the CIE pattern of A. alternata and 19 different allergens were identified in CRIE analysis (1 major, 7 intermediate and 6 minor allergens). There was a significant variation in the content of the major A. alternata allergen (Ag-8, partially identical to Alt-I) between the different individual strains. Furthermore, a considerable variation in the content of Ag-8 was observed for a specific strain cultivated at different occasions under identical cultivation conditions during a time period of 3 years.

Allergens↗
PubMed1987

Identification of dander-specific and serum-specific allergens in cat dandruff extract.

Cat dandruff extract was characterized by crossed immunoelectrophoresis (CIE) and crossed radioimmunoelectrophoresis (CRIE) using sera from 27 cat-sensitive individuals. By applying a CIE/CRIE system with intermediate gel, the content of dander-specific and serum-specific allergens was established. Thirteen serum-related and eight dander-related antigens were identified in cat dandruff. Of these, eight antigens were visibly radiostained in CRIE. Five allergens were serum-specific and of these allergens cat albumin was the most important (intermediate allergen). Three allergens were dander-specific and of these three only cat allergen I fulfilled the criteria for a major allergen.

Allergens↗