Biomedical subjects
Publications and source records attributed to J C Mitchell.
Bibliographic sources for the complex subject of aroma chemicals are reviewed. The references are not comprehensive but are those which we found to be of value in finding out some of the opportunities for contact with a sensitizing chemical compound, cinnamic aldehyde.
False positive patch test reactions are common when the skin of the back is hper-reactive. Such reactions can obscure or invalidate observations of multiple specific sensitivity and of cross-sensitivity to contactants. The pathogenesis of the hyper-reactive skin ('angry back') is discussed and a mechanism postulated for the notion that eczema at certain sites can provoke an eczematous tendency at other sites.
Some recent publications concerning perfume contact sensitivity are briefly reviewed. Japanese workers have identified some perfume sensitizers and have devised an allergen replacement system. Costus absolute of perfumery has been found to sensitize guinea-pig and man; sesquiterpene lactones are responsible for cross-sensitivity with some other plant products. Balsam of Peru is a useful screen for perfume sensitivity; terpenoids of balsams require study.
In two cases, occupational contact dermatitis was found to be due to chicory (Cichorium) used as a salad plant. In one of the two cases, contact sensitivity to letuce (Lactuca) was also observed. The sesquiterpene lactones of the plant may be the allergens.
Subcellular fractions were prepared from the epidermis of guinea pigs which had been painted with 1-chloro-2,4 dinitrobenzene 14 h previously. The microsomal fraction showed less activity than other fractions in the MIF test. Similarly, the microsomal fraction from the dermis of skin irritated with croton oil before DNCB painting was relatively inactive. However, the microsomal fractions from the epidermis and more especially from the dermis of skin painted with DNCB while undergoing allergic contact dermatitis from pentadecylcatechol showed significant MIF activities.
Many salad and vegetable plants are allergenic. Screening patch tests are restricted to known allergenic plant families. Aimed patch tests include all environmental plant contactants. Taraxacum (Dandelion) yields a potentially allergenic sesquiterpenelactone. International co-operation in authorship can save journal space.
Contact dermatitis from phenoxybenzamine hydrochloride occurred in a woman laboratory technician. Sensitization to this chemical was produced in guinea-pigs. Cross-sensitivity to related compounds may be due to the chloroethylamine moiety of the molecule. No cross-sensitivity was observed to the dichlorodiethylamine compound, nitrogen mustard.
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Occupational allergic contact dermatitis in 52 forest-workers was caused by sesquiterpene lactones from liverworts (Frullania) and by usnic acid from lichens which grow on various trees including cedar (Thuja). Occupational asthma and rhinitis in 35 wood-workers was caused by wood dust of western red cedar (Thuja plicata). Characteristically, the respiratory symptoms occurred in the evening and at night and not during working hours; inhalation challenge with plicatic acid from the wood provoked immediate, late or dual (combined immediate and late) asthmatic reactions. Another class of compounds, tropolones, derived from Thuja plicata wood, was responsible for dermatitis in a wood-worker. These distinct industrial hazards in two groups of workers at the tree-felling and wood-working levels in the forest-products industry can be identified by clinical history and examination supplemented by specific cutaneous or respiratory clinical investigation.
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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.
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.
Explore the source record for details and available documents.