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Biomedical subjects

R Voorhorst

Publications and source records attributed to R Voorhorst.

At least 37 records · Page 2Linked to original sources

Atopic skin test re-evaulated. IV. The use of compound 48/80 in routine skin testing.

Analysis of skin-test results obtained with compound 48/80 has indicated that this substance deserves a place in the standard series of test fluids for routine skin testing. No influence of sex or season was detected but there were significant differences in response related to the age (strongest reactions in the 16-40 year age group) and to the diagnosis (strongest reactions in the atopic patients).

Adolescent↗

The human dander atopy. I. The prototype of auto-atopy.

Human dander is shown to be a true allergen giving skin reactions most frequently in atopic patients. The clinical importance of human dander is discussed and data of a group of patients atopic only to human dander are given. It seems probable that human dander is an auto allergen and that there are many more auto allergens to which the atopic organism produces IgE-type antibodies.

Adolescent↗

The human dander atopy. II. human dander, a complicating factor in the study of the relationship between house dust and dermatophagoides allergens.

Besides describing some pitfalls frequently ignored in investigations on the house dust Dermatophagoides allergen problem, the author demonstrates that skin reactions due to the very small amount of "residual allergen activity" in house dust can be explained by the fact that house dust always contains a small percentage of human dander.

Dust↗

Atopic skin test re-evaluated. III. The wheal: flare ratio, the log-dose response curve and the bio-assay of allergen extracts.

It is demonstrated that the sum of the length and width of the flare is linearly correlated with the logarithm of the sum of the length and width of the wheal; on this basis a valuable "skin-reaction index" is proposed. Furthermore, the log-dose response curve of the skin reaction, at least in the medium-sized reactions, proved to be a straight line. These methods permit a bio-assay of allergens extracts giving a maximal dispersion of 100% above and below the exact value. Coefficient of variation: 62%.

Allergens↗

Standardization of allergens by an improved skin-testing technique.

From the seemingly most appropriate methods for standardization procedures of allergen extracts, the most serious candidates are in sequence of age: the old atopic skin test, the histamine-release test, using human basophil cells and the radio-allergosorbent test. At the moment it is not yet certain which method gives the most exact results, although, especially in the last ones - as part of the whole test - highly sophisticated methods are used. The skin test is not dependent on modern laboratory methods, is used on a world-wide scale, but as method studied very poorly. This is a matter of regret, because at any rate the skin test gives the clinician a lot of valuable information. The major drawbacks of the skin test are that the inclination of the log-dose response line is rather small and that the results of tests done with the same dose may vary sometimes not inconsiderably. Furthermore, the results are dependent on the sites of the skin where the tests are done and on the amount of fluid injected intracutaneously. There is a diurnal variability, a certain influence of the menstrual cycle and of course influence of medicaments (histamines). Nevertheless, taking all these factors into consideration and using a highly perfected method of skin testing, it appeared possible in 16 experiments, with not more than six volunteers per experiment, to reduce the variability of the bioassay between the limits of +50 and minus 50 per cent.

Allergens↗