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Biomedical subjects

A B Frostad

Publications and source records attributed to A B Frostad.

15 recordsLinked to original sources
PubMed1993

A comparison of topical levocabastine and sodium cromoglycate in the treatment of pollen-provoked allergic conjunctivitis.

A total of 71 patients with documented birch and grass pollen allergy participated in this randomized, double-blind, parallel-group study initiated to compare the long-term therapeutic efficacy of twice daily levocabastine, a new topical H1-receptor blocker, with that of sodium cromoglycate four times daily in the treatment of pollen-provoked conjunctivitis. There was no statistically significant difference in therapeutic efficacy between the two treatment groups, although a positive trend in favour of levocabastine was observed. Global evaluations of therapeutic efficacy were similar in both treatment groups. A total of 94% of levocabastine-treated patients rated treatment to be excellent or good compared with 86% of patients in the sodium cromoglycate group. Moreover, there were no significant differences in the severity of allergic symptoms reported on the patient diary cards. Patients were permitted to use rescue medication (oral terfenadine and betamethasone nasal spray) if symptoms became severe. The use of rescue medication was lower in the levocabastine group than in the sodium cromoglycate group. The mean number of days on which rescue medication was used was 12.8 and 26.9 in the two groups, respectively. The incidence, and type, of adverse reactions was similar in both patient groups. Levocabastine is well-tolerated and at least as effective as sodium cromoglycate in the treatment of pollen-provoked conjunctivitis.

Administration, Topical↗
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↗
PubMed1983

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↗
PubMed1980

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↗
PubMed1977

The treatment of seasonal allergic rhinitis with a 2% aqueous solution of sodium cromoglycate delivered by a metered dose nasal spray.

A double-blind, group comparative trial of 2% aqueous solution of sodium cromoglycate in seasonal allergic rhinitis (hay fever) is reported. All twenty-five patients in the active group found the treatment a success whereas fourteen out of nineteen in the placebo group regarded this as a failure. The method of application (metered dose spray) was acceptable to all patients.

Administration, Intranasal↗
PubMed1977

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↗