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- Bergendorff, Ola, et al.
(författare)
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Activation and cross-reactivity pattern of a new allergen in adhesive plaster
- 2000
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Ingår i: Contact Dermatitis. - : Wiley. - 0105-1873. ; 42:1, s. 11-17
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Tidskriftsartikel (refereegranskat)abstract
- N,N'-disalicylidene-1,2-diaminopropane is a copper inhibitor present in some adhesive plasters, rubber products and gasoline. Upon contact with water it is hydrolyzed to salicylaldehyde and 1,2-diaminopropane. All patients in this study showed positive patch-test reactions to N,N'-disalicylidene-1,2-diaminopropane, and also to 1,2-diaminopropane and ethylenediamine. None reacted to salicylaldehyde. Patch testing with different N,N'-disalicylidene-derivatives showed localization of the amino groups in positions 1 and 2 to be a prerequisite of cross-reactivity to 1,2-diaminopropane and ethylenediamine. An extraction procedure and a high-performance liquid chromatography (HPLC) method for the analysis of adhesive plasters is described. Studies of the hydrolysis of the copper inhibitor at physiological pH showed rapid formation of 1,2-diaminopropane under biomimetic conditions.
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- Bergendorff, Ola, et al.
(författare)
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Chemical changes in rubber allergens during vulcanization
- 2007
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Ingår i: Contact Dermatitis. - : Wiley. - 0105-1873 .- 1600-0536. ; 57:3, s. 152-157
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Tidskriftsartikel (refereegranskat)abstract
- Allergic contact dermatitis to rubber is caused by residues of chemicals used in manufacturing a rubber product. Several different additives are used to achieve a final product of the desired characteristics. Accelerators such as thiurams, dithiocarbamates, and mercaptobenzothiazoles are often among the additives responsible for allergic reactions recognized by dermatologists. The chemistry of the vulcanization process is complicated; as it occurs at an elevated temperature with a mixture of reactive chemicals, the compositions of the initial and final products differ. This paper investigates the changes in composition of common allergens during vulcanization, doing so by chemically analysing various rubber formulations at different stages of the process. Major changes were found in which added chemicals were consumed and new ones produced. An important observation is that thiuram disulfides rarely appear in the final rubber although they may have been used as additives. Instead, thiurams are often converted to dithiocarbamates or to products formed by addition to mercaptobenzothiazole structures, if these have been used together with thiurams as accelerators.
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- Bergendorff, Ola, et al.
(författare)
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Contact dermatitis to a rubber allergen with both dithiocarbamate and benzothiazole structure.
- 2007
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Ingår i: Contact Dermatitis. - : Wiley. - 0105-1873 .- 1600-0536. ; 56:5, s. 278-280
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Tidskriftsartikel (refereegranskat)abstract
- Contact dermatitis to rubber products are often caused by additives used during manufacture, and diagnosed from patch test with established rubber allergen series. In these series the compounds are divided into separate groups such as thiurams, dithiocarbamates and mercaptobenzothiazoles. The objectives were to investigate the substances with allergenic structures present in a diving mask giving rise to facial dermatitis, also those substances including structures from different groups of rubber chemicals. The rubber material was analysed by high-performance liquid chromatography and diode-array detector. The patient was tested by epicutaneous tests using pure substances, extracts and authentic rubber material. 2-Benzothiazolyl-N,N-diethylthiocarbamylsulfide, was found in the diving mask and the patient showed positive reaction to the pure compound and to extracts of the diving mask. This compound has structures of both mercaptobenzothiazole and thiuram/dithiocarbamate in its formulae. Besides the established groups of rubber accelerators, uncommon allergens with structures from more than one group can be formed or added at vulcanization. Chemical analysis of the product is needed to find these allergens.
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- Bergendorff, Ola, et al.
(författare)
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Stability of thiuram disulfides in patch test preparations and formation of asymmetric disulfides
- 2001
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Ingår i: Contact Dermatitis. - : Wiley. - 0105-1873. ; 45:3, s. 151-157
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Tidskriftsartikel (refereegranskat)abstract
- The thiuram mix used in patch testing originally contains 4 compounds. However, chemical analysis of the test preparation revealed that several new compounds are spontaneously formed during storage. The structures of these compounds have been determined and the rate of their formation has been studied in buffer solution at pH 7.4. After a few hours, a large amount of mixed disulfides are formed in solutions originally containing only symmetric disulfides. The impact on the test result of the formation of asymmetric disulfides has been investigated by testing on thiuram-sensitive volunteers with different preparations of mixed thiuram disulfides. In our study, the formation of new asymmetric thiuram disulfides from the original symmetric thiuram disulfides in the test preparation had no influence on the result of the patch testing. However, as the chemical analysis showed that the mix composition changes during the period when the preparations are used, and differs between suppliers, the question is raised as to whether it is acceptable to use test preparations with a composition that is different from that labelled on the protocol.
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