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Biomedical subjects

F Björkstén

Publications and source records attributed to F Björkstén.

At least 19 recordsLinked to original sources
PubMed2000

Detection and treatment of early asthma.

BACKGROUND: We sought answers to two questions: 1) how can mild, early asthma best be detected? 2) how should it be treated and the treatment effect monitored? METHODS: Eighty adult patients with early, mostly mild asthma and 30 control subjects were examined by lung-function and biochemical tests. Patients were randomly assigned to two treatment groups. One group was treated with an inhaled steroid (budesonide) for 6 weeks, and the other first with an inhaled beta2-agonist (terbutaline) for 6 weeks and then with an inhaled steroid for 2 weeks. RESULTS: Treatment with budesonide was effective: symptom scores, PEF, blood eosinophils, and sputum ECP values all improved. Terbutaline was ineffective by these criteria. For the detection of early asthma and for the following treatment effects, sputum and serum ECP assays are useful supplements to lung-function tests. CONCLUSIONS: Treatment of early, mild asthma with an inhaled steroid is effective and worthwhile. Detection of the disease remains a problem, as both lung-function and biochemical tests have low sensitivities.

Administration, Inhalation↗
PubMed1996

Can early asthma be confirmed by laboratory tests?

We examined the performance of a number of laboratory tests in 23 patients who had had symptoms suggesting asthma, such as cough, sputum secretion, and chest tightness with wheezing, for less than a year. Even the best test, histamine challenge, had a sensitivity of only 48%. When more tests were added, sensitivity rose: with peak expiratory flow added, the sensitivity was 65%; with sputum eosinophil cationic protein (ECP) added, to 74%; and with serum ECP added, to 78%. Thus, a combination of tests measuring lung function and activation of eosinophils yielded fair, if not good, results. It appears that sensitivity could be increased further through the development of improved sputum tests.

Adolescent↗
PubMed1996

Stability of cereal allergens.

BACKGROUND: Ingested cereals and inhaled cereal dusts can cause IgE-mediated allergy. Testing for these allergies yields variable, often undependable results, which could be due to the use of unsuitable or degraded testing materials. OBJECTIVE: We studied the effect of storage media, time and temperature on the stability of protein allergens extracted from wheat, rye, barley and oats flour. We also examined the effect of heat processing similar to that used when preparing foods on the stability of allergenic proteins present in wheat flour. METHODS: After storage experiments proteins in allergen extracts were separated using sodium dodecyl sulfate-polyacrylamide gel electrophoresis and then visualized using immunoblotting or staining with Coomassie brilliant blue. After heat processing wheat flour proteins were extracted and their IgE-binding capacity was estimated. RESULTS: Extracted proteins from wheat, rye and barley flour appeared stable for at least 21 months when stored at 4 degrees C in an aqueous solution containing 50% glycerol and 0.45% sodium chloride. In a medium with 0.4% phenol and 0.9% sodium chloride degradation of many proteins became apparent already after 1 month of storage. Oats extracts lost their IgE-binding capacity more rapidly and the maximal storage time appeared to be 10 months at 4 degrees C in a solution containing 50% glycerol and 0.45% sodium chloride. The IgE-binding capacity of the allergenic proteins decreased as heat-processing temperature and heating time increased. No processing conditions entirely abolished IgE-binding. CONCLUSION: Cereal allergen preparations can be stored either in lyophilized form or at 4 degrees C in 50% glycerol. Unheated materials should be used also when testing for food allergy, as heating reduces allergenicity and thus sensitivity at testing.

Adolescent↗
PubMed1990

Prevalence of asthma in Finnish young men.

OBJECTIVE: To determine the prevalence of asthma in cohorts of Finnish young men in the period 1926-89. DESIGN: A retrospective analysis using reports and statistics of Finnish defence forces. SETTING: Call up examinations of candidates for military conscription and examination of conscripts discharged because of poor health. SUBJECTS: Roughly 900,000 men--that is, 98% of men of conscription age--examined in 1966-89 and a proportional but unknown number examined in 1926-61. MAIN OUTCOME MEASURES: Asthma recognised at call up examination, exemption from military service, and discharge from military service because of asthma. RESULTS: During 1926-61 the prevalence of asthma recorded at call up examinations remained steady at between 0.02% and 0.08%. Between 1961 and 1966, however, a continuous, linear rise began, the prevalence increasing from 0.29% in 1966 to 1.79% in 1989--that is, representing a sixfold increase. Compared with 1961 the rise was 20-fold. From 1966 to 1989 the sum of exemptions and discharges from military service due to asthma increased analogously sixfold. CONCLUSIONS: If the apparent increase in asthma detected in Finnish young men was due entirely to improved diagnostic methods and other confounding effects then some 95% of cases must have gone undiagnosed in the years before 1966. This seems inconceivable, which suggests that much of the increase was real. This conclusion is strengthened by the observed rise in exemptions and discharges due to asthma.

Adult↗
PubMed1990

A simplified Boyden chamber assay for neutrophil chemotaxis based on quantitation of myeloperoxidase.

Cell locomotion and chemotaxis are usually assayed by the Boyden chamber technique, in which the response is measured by microscopical counting of the cells migrated into a micropore filter. We report a simplified Boyden chamber method which utilizes myeloperoxidase (MPO) specific to neutrophilic and monocytic leukocytes. The chamber is incubated for a period long enough for the neutrophils to migrate through the first of two superimposed filters. The cells entering the second filter are then lysed and the released MPO activity is quantitated. Random migration, chemokinesis, and chemotaxis measurements of neutrophils were compared by the enzymatic and the conventional cell count methods. There was good agreement between the two methods (0.84 less than r less than 0.98). The intraassay precision of the enzymatic and the cell count methods was equal; the coefficients of variation were 14 and 15%, respectively. The enzymatic method provides a more objective, reliable, and rapid modification of the Boyden chamber assay for analysis of neutrophil chemotaxis.

Caseins↗
PubMed1989

Spice allergy: results of skin prick tests and RAST with spice extracts.

Skin prick tests (SPT) with freeze-dried spices and 5% (w/v) spice extracts were performed on 50 patients with 2+ or stronger SPT reactions to spices per se, and RAST were performed on 10 of them. Freeze-dried extracts produced mostly equal or stronger SPT reactions than corresponding whole spices, but 5% (w/v) extracts produced weaker reactions and also remained totally negative in some patients. Positive RAST results were seen in all 10 patients tested. The correlation between the RAST and SPT results was good for mustard and paprika, but poor for cayenne, coriander, caraway and white pepper. Five patients with positive SPT and RAST for spices contracted rhinitis from powdered spices in their working environments, and one patient suffered from gastrointestinal pains caused by spiced food. The others had noticed no clinical symptoms caused by spices. The present results thus indicate that both SPT and RAST should include purified spice extracts.

Adolescent↗
PubMed1988

Percutaneous absorption of hydrocortisone during exacerbation and remission of atopic dermatitis in adults.

Percutaneous absorption of hydrocortisone was studied in 18 young adults during and after the acute phase of atopic dermatitis using the direct hydrocortisone absorption test. In the acute phase the post-application increase in serum cortisol concentration ranged between 18 and 711 nmol/l (median 125 nmol/l). In remission the increase in serum cortisol ranged between 0 and 114 nmol/l (median 16 nmol/l), which was significantly lower than the rise in the acute phase. In the acute phase of dermatitis, topical hydrocortisone treatment has both a local and a systemic effect, due to percutaneous absorption.

Acute Disease↗
PubMed1987

Comparison of atracurium and vecuronium in anaesthesia for renal transplantation.

In a controlled study, equipotent doses of atracurium (20 patients) or vecuronium (22 patients) were given randomly to patients with chronic renal failure anaesthetized for renal transplantation. There were no statistically significant differences in the degree of muscle relaxation (electromyographic twitch response) and circulatory parameters. Plasma histamine concentration increased in three patients after the first dose of atracurium, but in none of the patients could any signs of allergic reactions be observed. Tracheal intubation was difficult in six patients of the atracurium group, all of whom had diabetes mellitus and varying degrees of neck stiffness. The neuromuscular block response in diabetic uraemic patients was similar to that in other uraemic patients.

Anesthesia, General↗
PubMed1985

Allergic conjunctivitis, total and specific IgE in the tear fluid.

Twenty-three patients with allergic conjunctivitis caused by birch, timothy or mugwort pollen were examined for the presence of total and specific IgE in the tear fluid. In thirteen of the 23 patients IgE could be shown in the tears. Specific IgE antibodies against the causative pollens were present in the tear fluid of 8 of the patients. The relation between serum and tear IgE on one hand and serum and tear albumin on the other hand suggests local production of the specific IgE antibody.

Adolescent↗
PubMed1984

Assay of the biologic activity of allergen skin test preparations.

We studied the biologic activity of allergen preparations using a method involving skin prick tests in humans and the use of HEP (histamine equivalent prick) units. Results were found to be dependent on the population groups used in assays. If populations are not carefully standardized, results may vary by 1 power of 10. Accuracy can also be improved by the use of suitable allergen standard reference preparations, but such were not available to us. Confidence ranges for the biologic activities were relatively wide and varied with the allergen preparation and the population group. Typically, the 95% confidence range included values from one-fifth to five times the estimated HEP value when the number of subjects in the assay was 30 to 50 persons. When the preparations representing the same source material (e.g., timothy pollen) were assayed simultaneously in one population group of this size, a twofold or larger difference in HEP values generally proved significant. An examination of 43 commercial products showed that allergen preparations with biologic activities declared in HEP units had a more uniform biologic activity than those assayed with traditional methods and units (PNU/ml or weight/volume).

Adolescent↗
PubMed1984

Do infections in infancy affect sensitization to airborne allergens and development of atopic disease? A retrospective study of seven-year-old children.

We studied 145 children aged 7 years, who had been at day-care centers for at least 3 months during the 2 first years of their lives. The group was compared with a matched population of 145 children cared for at home. Of the 290 children, 212 participated in all phases of the study, which included a questionnaire to parents, skin prick tests with seven allergens, and a clinical examination. Day-care-center children had twice as much otitis media in infancy as "home" children (P less than 0.001), and they also tended to have more other infections. On the other hand, day-care-center children did not have more eczema in infancy, more cumulated atopic disease by the age of seven, or more positive skin tests than home children. When the groups were combined, an increased prevalence of cumulated atopic disease and positive skin tests was found in children with infections in infancy. We conclude that under the conditions of this study infections in infancy did not facilitate the development of hypersensitivity to allergens and atopic disease. The linked tendencies to develop infections and atopy could depend on some third factor.

Allergens↗
PubMed1984

Cross-reactivity of IgE antibodies with allergens in birch pollen, fruits and vegetables.

Allergens extracted from apple, carrot, celery tuber and orange were coupled to radioallergosorbent test (RAST) discs. These and commercial birch, mugwort and timothy pollen discs were used to study sera from 90 patients for the presence of IgE antibodies which react with the allergens in question. Individual sera frequently gave positive results with several discs - in particular with birch pollen, apple, carrot and celery tuber discs. If IgE antibodies to birch pollen or apple allergens were detected, there was a 90% chance of antibodies being found also to the second one of these two source materials. Skin tests and patient histories indicated similar clustering of allergies. RAST inhibition experiments showed that the clustering phenomenon was due to cross-reactivity. All immunological determinants in fruits and vegetables appeared to be present also in birch pollen, but all birch pollen determinants were not present in fruits and vegetables. 45 children with atopic dermatitis were studied to establish whether a positive orange RAST would correlate with a history of atopic dermatitis aggravated by orange. The results were negative.

Adolescent↗