Biomedical subjects
Publications and source records attributed to R Voorhorst.
In a group of patients atopic to tree pollen the authors found that the skin reactions to six tree-pollen extracts in three ten-fold dilutions had roughly the same correlation coefficient as those for two identical extracts (0.74) e.g., between poplar and willow and among hazel, alder, birch, oak, and beech.
With a perfected technique of skin testing it was impossible to demonstrate any significant difference in skin reactivity to pollen extracts deriving from four grass species. When pollen allergen from three grass species were used, The RAST-test results did not differ from duplicate values either.
With a modified Morrow Brown needle it proved possible to obtain duplicate skin-test values with almost the same reliability as those obtained with the intracutaneous method described in one of the preceding papers of this series. The results of the present study also showed that 50% glycerin has a distinct inhibitory effect when added to the extracts, whereas 0.0005% Tween 80 produces a distinct enhancement of the skin reaction.
A "mechanical oscilloscope" is described in which a lightbeam (Z-axis) is projected via a single front aluminized moving mirror. The mirror is mounted in a suspension frame allowing the simultaneous rotation about two mutually perpendicular axes. The linear displacements of two loudspeaker-coils are transformed mechanically into mirror rotations and an electronic position/velocity feedback control system is used to drive the loudspeakers. The bandwidth of the resulting X- and Y-axis deflection systems is of the order of 100-200 Hz. The flexibility of Z-axis control (colour, pattern, intensity, etc.) makes this instrument an attractive component of light stimulation systems for psychophysical or electrophysiological studies of vision.
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Four patients with a clinical picture resembling that of scarlatina are described. This clinical picture was found to be based on a delayed-type allergy for codeine and morphine. Investigation showed that the codeine or morphine allergy is essentially dependent on the hydroxyl group at the 6 position of the basic phenanthrene structure but only when this group is bound equatorially, as is the case for codeine and morphine.
Desensitization with aqueous grass-pollen extracts led to a considerable decrease in skin reactivity (by a factor of 50). This decrease proved not to be specific for the grass-pollen species used.
A patient is described with a clinical picture resembling that of relapsing scarlatina. The complaints were found to be based on two types of delayed-type allergy: one to the equatorially bound hydroxyl grouip at the 6 position of the basic phenanthrene structure as occurs in morphine and codeine, and the other to the D(-)-alpha-position of the amino group as occurs in some penicillin derivatives.
Some formulas are given for the relationship between the sizes of wheals and flares of skin reactions to three allergen extracts and to histamine and compound 48/80. Only compound 48/80 shows a somewhat different wheal/flare relationship.
Using a perfected technique for skin testing, no difference was found between skin reactions to either histamine or compound 48/80 in atopic and non-atopic patients or in healthy volunteers. The correlation of the size of the skin reactions to both compounds was only slightly lower than the correlation of the duplicates, which indicates that compound 48/80 can be used as a control extract in skin testing. The skin reactions to this compound are read after 15 minutes, just as those to inhalant allergens.
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The use of an immunofluorescence method for demonstration of non-capsulated H. influenzae colonization and penetration in the tissues of the respiratory tract seems to be a useful and convenient laboratory method. However, in in the tissues of the lower respiratory tract H. influenzae in our materials could not be demonstrated.
Atopy to dander from domestic animals occurs rather frequently in atopic patients, especially danders from the cat, guinea-pig, horse, rabbit, and golden hamster. There is no clear sex difference. The age group in which the phenomenon is found most frequently is from 21 to 30 years. As in hay-fever patients during the season, we found a double-peaked frequency curve for the blood eosinophilia. Animal-dander atopy was diagnosed particularly in patients with asthma and/or with atopic eczema. The strength of skin reactions to a series of three tenfold dilutions of standardized test extracts appears to be a good index for the origin of clinical symptoms after contact with the relevant animals.
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Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.