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Biomedical subjects

L Trulsson

Publications and source records attributed to L Trulsson.

At least 19 recordsLinked to original sources

Allergic contact dermatitis from diphenylthiourea in Vulkan heat retainers.

11 cases of contact dermatitis from Vulkan heat retainers are reported. The skin eruptions started on days 1-11 after the 1st day of exposure. The clinical picture varied from eczema through urticaria to purpura. In some cases, the symptoms were severe. Patch testing was performed in 10 individuals and all reacted positively to the heat retainer and/or the rubber glue used in the heat retainer. A series of rubber chemicals was patch tested in 7 patients and all showed positive reactions to diphenylthiourea (DPTU), and all but one to ethylene thiourea (ETU). TLC examination revealed a spot with the same RF-value as DPTU in extracts of the adhesive, but no spot corresponding to ETU. There were no indications of impurities in the test preparations of DPTU and ETU. By HPLC, the content of DPTU in the adhesive was determined as 0.6% w/w.

Adhesives

Demonstration of contact sensitizers in resins and products based on phenol-formaldehyde.

12 phenol-formaldehyde resins were investigated with regard to the presence of 14 contact sensitizers by using high-pressure liquid chromatography. The allergens consisted of simple methylol phenols, dihydroxydiphenyl methanes, 4,4(1)-dihydroxy-(hydroxymethyl)-diphenyl methanes and 2,4(1)-dihydroxy-(hydroxymethyl)-diphenyl methanes. Four substances, 2,4-dimethylol phenol, 2,6-dimethylol phenol, 4,4(1)-dihydroxydiphenyl methane and 2,4(1)-dihydroxydiphenyl methane, were isolated from a resol resin and identified by mass-spectrometry and nuclear magnetic resonance spectrometry. The highest concentrations (up to 15% w/w) of allergens were noted for methylol phenols in resol resins based on phenol and formaldehyde. The corresponding novolak resins showed a high content of dihydroxydiphenyl methanes. There was great variation in concentration of the sensitizers between the resins. None of these sensitizers were demonstrated in the resin based on paratertiary-butyl phenol. Products based on phenol-formaldehyde resins were also investigated for the presence of allergens. Uncured impregnated paper for laminate production and uncured mineral wool contained the same concentrations of the sensitizers as some of the resins studied. The curing process decreased the content of all the allergens investigated in all products, but the sensitizers did not disappear, and they may thus be present in finished products.

Allergens

An attempt to isolate and identify allergens in lanolin.

One sensitizer, a sterol, has previously been reported to be present in lanolin. In this study, a related substance, a sterol, with a molecular weight of 424 has been isolated. A few sensitive subjects did not react to this substance. Lanolin probably contains several sensitizers. Sensitization to lanolin in guinea pigs seems previously to have failed. In this study, a methanol extract of a lanolin preparation containing large amounts of sterols sensitized guinea pigs.

Allergens

Contact allergy to styrene and related chemicals.

One patient, sensitive to styrene, cross-reacted at patch testing to 2-,3-and 4-vinyltoluene (2-,3-and 4-methylstyrene) and to the metabolites styrene epoxide and 4-vinylphenol (4-hydroxy-styrene). It is assumed that styrene is a prohapten metabolized in the skin by aryl hydrocarbon hydroxylase (AHH) to styrene epoxide acting as the true hapten. Styrene occurs in nature and as a synthetic product. Vinyltoluenes (methylstyrenes) occur as synthetic products in plastics. 4-vinylphenol (4-hydroxystyrene) occurs frequently in different ciders, wines, foods and berries, e.g. cloudberry.

Dermatitis, Atopic

Contact dermatitis from the epoxy resins tetraglycidyl-4,4'-methylene dianiline and o-diglycidyl phthalate in composite material.

An outbreak of dermatitis occurred in an aircraft factory using epoxy resin composite material. Of 25 operatives, 14 gave positive patch test reactions to the composite material and/or diglycidylether of bisphenol A (DGEBA), tetraglycidyl-4,4'-methylene dianiline (TGMDA), and o-diglycidyl phthalate. This report seems to be the first to demonstrate contact allergy to the two last mentioned epoxy resins. The diglycidylether of bisphenol A used in routine test series picked up only 3 cases of 12 tested.

Aniline Compounds

Simple methods for demonstration of epoxy resins of bisphenol A type.

Low molecular weight oligomers of epoxy resins of bisphenol A type are common sensitizers. For demonstrating the presence of sensitizing oligomers of these resins, two simple methods are described. The first one, a colour reaction, demonstrates the presence of the bisphenol A skeleton. If this test is positive, thin-layer chromatography is carried out to demonstrate the presence of low molecular weight oligomers of epoxy resins. Some practical applications are reported.

Chromatography, Thin Layer