Contrast media and fibrin formation: interpretation and implications.
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Blood Coagulation↗
Biomedical subjects
H Vik
Publications and source records attributed to H Vik.
Dust from carpeted and smooth floors--III. Trials on denaturation of allergenic proteins by household cleaning solutions and chemical detergents.
The effects of detergents on antigens and allergens of birch and timothy grass pollen extracts, codfish, hen egg-white, cat dander and house dust mite were investigated by crossed immunoelectrophoresis (CIE), crossed radio-immunoelectrophoresis (CRIE), radio-allergosorbent test (RAST) inhibition and quantitative precipitation test using laser nephelometry. Nine household cleaning solutions and five chemical detergents were tested. Higher concentrations than recommended for regular cleaning purposes were used as no influence on the antigenic and allergenic activities could be detected using the usual concentrations. Soft soap, guanidine hydrochloride and sodium lauryl sulphate induced most modifications of the antigens and allergens tested. None of the detergents totally destroyed the antigenic and allergenic activities of the selected material, even when used in concentrations up to 10 times that recommended. The materials used for carpet cleaning would not be able to impose any denaturing effects on allergens left on carpets after cleaning.
Allergens↗
Purification and N-terminal amino acid sequence of two birch pollen isoallergens (Bet v I and Bet v II).
The major allergen of birch pollen BV45 (Bet v I) was previously isolated by molecular weight exclusion chromatography and eluted in the molecular weight region of 15-29 KD. Further purification of this fraction on an SP-Trisacryl M cation exchange matrix allowed 6 peaks of which which the 4th (BV4A4) and 6th (BV4A6) included two dominant IgE-binding birch pollen isoallergens designated Bet v I and Bet v II. Final purification, using the 'Applied Biosystems' Peptide Micro Separation System, revealed two sharp peaks with a high degree of homogeneity. This was ascertained by automatic N-terminal amino acid (AA) sequence analyses which showed high average repetitive yields of the phenyl-thiohydantoin (PTH) AAs of the isoallergens sequenced. N-terminal AA analyses of the two fractions allowed 51 cleavages with correct identifications of PTH AAs for 3 replicates. The sequence data of the two isoallergens showed large homologies with the hazel pollen allergen, Cor a I, the birch pollen allergen, Ag 23, and the translated cDNA sequence derived from cloning birch pollen allergen genes. The sequence homologies support that Betula verrucosa allergens were derived from a gene family expressing several isologous allergens, 2 of which with 13 variable residues in a segment of 51 AAs. The antigenicity of the two fractions, Bet v I and Bet v II, was demonstrated by fused rocket immunoelectrophoresis (FRIE) and by crossed immunoelectrophoresis (CIE) giving single symmetrical antigenic precipitation.(ABSTRACT TRUNCATED AT 250 WORDS)
Allergens↗
Dust from carpeted and smooth floors. I. Comparative measurements of antigenic and allergenic proteins in dust vacuumed from carpeted and non-carpeted classrooms in Norwegian schools.
Dust samples from fitted-carpets and linoleum floors in 12 schools in Norway were collected by vacuum cleaning. The presence of antigens and allergens of alder (Alnus incana), birch (Betula verrucosa), timothy (Phleum pratense), mould (Cladosporium herbarum), house dust mite (Dermatophagoides farinae), cat and dog dander, codfish, hen egg white and human dander were investigated by crossed immunoelectrophoresis (CIE), crossed radio-immunoelectrophoresis (CRIE) and radio-allergosorbent test (RAST) inhibition. No qualitative differences in allergen contents of dust from both types of floor tested were noted. Similarly, no relationship could be demonstrated between floor-type and allergen concentration under identical experimental conditions. Antigens and allergens of both cat and dog were frequently demonstrated in dust extracts. All extracts included human dander and mould allergens. In addition, most dust samples from both carpeted and smooth floors contained hen egg white and codfish allergens. Furthermore, the study demonstrated that dust from smooth floors and fitted-carpets was relatively free of mite and pollen from alder, birch and timothy.
Allergens↗
Dust from carpeted and smooth floors. II. Antigenic and allergenic content of dust vacuumed from carpeted and smooth floors in schools under routine cleaning schedules.
Dust samples were collected twice from smooth and carpeted floors in 10 Norwegian schools. The content of antigens and allergens of alder (Alnus incana), birch (Betula verrucosa), timothy (Phleum pratense), cat and dog dander, house dust mite (Dermatophagoides farinae), mould (Cladosporium herbarum), hen egg white and codfish (DIII) were investigated by crossed immunoelectrophoresis (CIE), crossed radio immunoelectrophoresis (CRIE), radio allergosorbent test (RAST) inhibition and quantitative precipitation inhibition analysis by laser nephelometry. Antigens and allergens of cat and dog dander and hen egg white were most prevalent in the dust samples investigated. With the exception of hen egg white and codfish allergens, no statistically significant differences in mean allergen content were shown in identical quantities of freeze-dried dust extracts from carpeted and smooth floors. RAST-inhibition analyses of identical amounts of dust from either floors showed higher content of allergens of cat, dog, hen egg white, codfish, mould and timothy pollen in classrooms with carpets.
Allergens↗
Reestimations of the protein concentrations of birch pollen allergen extracts selected as candidates for the international standard (IS) preparation.
The total protein concentrations of six selected candidates for an international standard (IS) of birch pollen were previously estimated (Ann Allergy 1987;58:71-77). The results of analyses showed large variations depending both on the method and the reference protein used. More than 2-fold variations in the protein content were obtained using Bradford's protein binding method. In the present communication the protein contents of these birch IS-candidates were reestimated by Lowry, a modified Lowry technique, Bradford's protein-dye binding, bicinchoninic acid reagent and amino acid compositions. Great variations were obtained for the protein contents, depending on the technique employed, emphasizing the difficulties of choosing a proper method of protein analyses of pollen allergens. The Lowry and the bicinchoninic acid reagent methods gave the highest obtained protein estimates, while the modified Lowry and Bradford's protein-dye binding methods showed the lowest values. The amino acid analysis gave concentrations similar to those obtained by Lowry and bicinchoninic acid reagent methods. The Lowry method seemed to be adequate for the analysis of plant proteins. The amino acid analysis is currently the most precise method for estimation of the protein concentration irrespective of additional prosthetic groups. A serious shortcoming of the method is that it requires an amino acid analyser or other liquid chromatrographic systems, which are not commonly in laboratory use.
Amino Acids↗
Immuno-electronmicroscopic identification and localization of the antigenic proteins of tree pollen grains.
The localization of antigenic proteins on ultrathin sections of pollen grains represents an interesting approach to understanding the release mechanisms of these antigens when the pollen grains come in contact with various physiological fluids. Using different rabbit antibodies we have demonstrated the locations of these antigens in the various structures of pollen grains. We further demonstrated the cross-reactivities between alder (Alnus incana), birch (Betula verrucosa) and hazel (Corylus avellana) pollen allergens. Ultrathin sections of the pollen grains were prepared and allowed to react with two individually raised rabbit antibodies, (Ab-BV and Ab-ALK), against birch pollen. The sites of the Ag/Ab complex on the sections were labelled by protein A/gold, and identified in a transmission electron microscope. The two birch antibodies showed either quantitative or qualitative differences regarding their binding to various structures on the pollen sections. Using Ab-BV, the antigen-binding sites were located in the apertural region of the pollen grain and in the cytoplasm, while almost no gold labelling could be seen on the pollen surface. With the other antibodies (Ab-ALK), we could visualize the antigen-binding locations on the surface material of the pollen grains, particularly in the exine part of the wall and in the cytoplasm. A few gold particles could also be seen in the apertural region of the pollen. In hazel and alder pollen the exine part of the wall was the most densely labelled, whereas the cytoplasm and the aperture bound smaller numbers of gold particles. Cross-incubations: birch pollen incubated with antibodies against hazel (Ab-CA), or alder (Ab-AI), showed various intensities of gold labelling for each of the three species. Statistically, the differences in the number of gold particles bound per micron 2 grain section between birch, hazel and alder, were highly significant. The cross-reactivities between these antigens from the three pollen species were further tested using house-produced rabbit antisera against antigens of the three species by means of electrophoretic and autoradiographic techniques (CIE and CRIE). The three antibodies could precipitate the major IgE-binding antigen from all three pollen species.
Animals↗
A comparison of the antigenic and allergenic components of birch and alder pollens in Scandinavia and Australia.
Allergens in birch (Betula) pollens from B. pendula grown in Australia and Norway, B. davurica and B. populofolia and from alder (Alnus incana) were identified by electroblotting, following separation by SDS-PAGE, transfer to nitrocellulose membranes and incubation with sera from birch pollen-allergic subjects. Of 42 antigenic components detected by protein staining in the pollen extract from B. pendula grown in Norway, 17 bound IgE. The allergenic components included those already reported in the literature at MWs of 40, 29, 25, 17 and 10-12 kd, as well as previously undescribed components at MWs of 90, 79, 60, 50, 38, 35, 31, 27, 23, 16, 15 and 14 kd. The major IgE-binding components were located in the low MW region 10-17 kd for all species of birch and alder pollen proteins studied. Results reported here provide the first evidence of birch and alder pollen allergies in Australia. Extensive heterogeneity was observed amongst the sera from birch pollen-allergic subjects in both Norway and Australia. Cross-reactivity appears to exist among the proteins present in pollen from the various birch species and from alder.
Australia↗
Comparative studies on tree pollen allergens. XIV. Characterization of the birch (Betula verrucosa) and hazel (Corylus avellana) pollen extracts by horizontal 2-D SDS-PAGE combined with electrophoretic transfer and IgE immunoautoradiography.
The crude aqueous extracts of birch (Betula verrucosa) and hazel (Corylus avellana) pollen were characterized by horizontal isoelectric focusing (IEF) and one-dimensional and two-dimensional sodium dodecyl sulfate polyacrylamide gel electrophoresis (1-D and 2-D SDS/PAGE). Isoelectric focusing reference patterns obtained in pH 3.5 to 9.5 gradient gels contained 31 and 41 bands while the 2-D patterns consisted of 51 and 72 protein spots, respectively. Electrophoretic transfer to nitrocellulose membranes and subsequent 125I-immunoautoradiography demonstrated IgE binding in the region between pH 4.8 and 5.4 for both extracts. The main allergenic reactivities of this pH region were distributed by SDS/PAGE to the molecular weights of 29.5, 17, and 12.5 kilodaltons for birch and 15.5 and 12 kilodaltons for hazel. The high resolving power and the independence of rabbit antibodies were considered the major advantages of the described 2-D methodology as compared with conventional crossed immunoelectrophoretic and radioimmunoelectrophoretic techniques.
Animals↗
[Regulation of the IgE antibody response].
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Animals↗
Comparative studies on tree pollen allergens. XVII. Immunochemical analysis of the international standardization extracts of birch (Betula verrucosa) pollen as compared with a local partially purified extract.
Six different birch pollen extracts were analyzed by 20 laboratories for the standardization of birch (Betula verrucosa) pollen extracts used for diagnosis and specific therapy of patients with birch pollen allergy. The extracts were collected and delivered by the International Union of Immunological Societies, Allergen Standardization Subcommittee. One of the extracts, designated M, was proposed as an international standard (IS)-candidate of birch pollen extracts. The protein content of the IS candidate M was found to be 1.12 mg/mL, more than 2-fold higher than any of the other extracts analyzed. This preparation was among the extracts containing the highest number of protein components, as shown by isoelectric focusing, 28 lines, and by 11 precipitates in crossed immunoelectrophoresis. The allergenic reactivities were tested by crossed radioimmunoelectrophoresis (CRIE) and by radioallergosorbent test (RAST)-inhibition. In CRIE, the proposed IS (M) showed similar affinity for binding patients' IgE as the other extracts, as judged by the autoradiographic illustrations. Except for extract L, the values of RAST-inhibition for the rest were very similar. An IS extract should qualify for the criteria suggested for an optimal allergen preparation, containing minimal amounts of non-allergenic antigens and providing quantitatively and qualitatively all the allergenic proteins. The appropriateness of this selection seems unjustified in view of the above criteria.
Allergens↗
Different induction of microsomal carboxylesterases, palmitoyl-CoA hydrolase and acyl-L-carnitine hydrolase in rat liver after treatment with clofibrate.
The levels of hepatic carboxylesterases, including palmitoyl-CoA hydrolase and decanoyl-D,L-carnitine hydrolase, were studied in total homogenates and subcellular fractions prepared from the livers of male rats fed diets containing 0.3% clofibrate. The microsomal carboxylesterase as well as the fatty acyl-thioesterase are differently induced by clofibrate feeding. The specific activities of acetanilide carboxylesterase and decanoyl-D,L-carnitine hydrolase increased more than 3-fold in the microsomal fraction, compared to pellet-fed control animals. The microsomal activities of palmitoyl-CoA hydrolase and propanidid hydrolase were decreased by about 20 to 40% in clofibrate-treated rats. The specific clofibrate hydrolase activity remained unchanged after clofibrate administration, indicating that this microsomal carboxylesterase is not induced by its own substrate. The data suggest a different distribution of the differing carboxylesterase along the endoplasmic reticulum.
Acetanilides↗
[Clinical biochemical analyses. Reference values].
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Chemistry, Clinical↗
[Diagnostic values of clinical biochemical analyses].
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Chemistry, Clinical↗
[Variations in clinical biochemical tests].
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Chemistry, Clinical↗
Determination of silver in biological samples using graphite furnace atomic absorption spectrometry based on Zeeman effect background correction and matrix modification.
A method for the determination of silver in human body fluids and biological material is described. The silver in an acid digest of biological samples and diluted body fluids is quantified using Zeeman graphite furnace atomic absorption spectrometry (ZGFAAS). The effects of NH4H2PO4 as matrix modifier and standard addition are discussed. Atomization from the graphite tube wall and from the pyrolytical tube with platform is also discussed and the peak height and the peak area are compared. The best results were achieved by using matrix modification, stabilized temperature platform furnace, integrated absorbance and standard addition technique. The calibration was linear up to 15 micrograms X L-1; the between-run precision was 5.9% at 40 micrograms X kg-1 of silver.
Animals↗
Antigenic and allergenic determinants of ovalbumin. I. Peptide mapping, cleavage at the methionyl peptide bonds and enzymic hydrolysis of native and carboxymethyl OA.
The effects of enzymic cleavage and perturbing the conformation of the allergenic and antigenic determinants of hens egg white albumin (OA) were examined. Hens egg white extract of a total protein concentration 8.43 g/l was prepared. Isoelectric focusing in sodium dodecyl sulfate and polyacrylamide gel peptide maps for the crude egg white extract showed 26 spots visualized by staining with Coomassie blue. The OA was purified using a TSK-2000 gel filtration chromatography column. The specific allergenic reactivity of the purified OA as measured by RAST inhibition and direct RAST was relatively high: 3 micrograms gave an inhibition of approximately 10%. The cleavage of OA with cyanogen bromide resulted in 4 fractions, all capable of binding specific IgE with the first peak showing the highest inhibition. Thermal denaturation of OA had no direct effect on the antigenic reactivity. RAST inhibition values for the denatured protein were similar to those of the native protein. Carboxymethylation of OA gave a product with only 20% of the inhibition reactivity. Further treatment with trypsin did not abolish the allergenic and antigenic reactivities as shown by RAST inhibition and by deflection of OA line in rocket line immunoelectrophoresis. On the other hand, limited pepsin hydrolysis destroyed the antigenic structure of the molecule. The reactivity of OA is thus relatively stable and could easily be retained making it possible to identify the allergenic determinants of enzymic hydrolysates used for elucidating the antigenic structure of the molecule.
Allergens↗
Comparative studies on tree pollen allergens. XI. Trials on the regulation of IgE response in mice using modified birch pollen allergens.
The major allergen of birch pollen, BV45, was isolated and conjugated to 2-o-methoxy polyethylene glycol-4,6-dichloro-5-triazine (mPEG). The molecular-weight variant of 6,000 daltons of the activated mPEG was used in an antigen-specific regulation of IgE response. In these studies 200 genetically high IgE responders (CBA/Ca) female mice were intradermally immunized by the purified BV45, with the use of various adjuvants. Four different sets of experiments were made. In the first experiment 50 mice were immunized on days 1 and 15 with BV45. This was followed by another booster dose of the native BV45 or the modified mPEG-BV45 in Freund's incomplete adjuvants (FIA) on day 72. In the 2nd experiment, a similar procedure was performed except that booster doses were injected on day 135. Subsequently on day 136, BV45/FIA was intradermally injected. In the 3rd and 4th sets of experiments, 2 groups of 50 mice were daily immunized by intraperitoneal injections of 10 successive doses of BV45. On day 33 a dose of BV45 or mPEG-BV45 respectively, was intraperitoneally injected in each mouse. This injection was followed by other 10 successive doses of BV45. In experiment 3 no adjuvants were used, and in experiment 4 aluminium hydroxide gel was used as adjuvant. The mice immune response was assessed by analyses of the serum IgG and IgE levels. In all experiments higher IgG concentrations were shown for the immunized mice as compared to the non-treated control animals. Administration of booster doses of BV45 or mPEG-BV45 induced increases in the IgG levels.(ABSTRACT TRUNCATED AT 250 WORDS)
Allergens↗