Cross-sensitization patterns in guinea pigs between cinnamaldehyde, cinnamyl alcohol and cinnamic acid.

Guinea pig maximization tests (GPMT) were performed with cinnamon substances. There was a certain degree of cross-reactivity between cinnamaldehyde, cinnamyl alcohol and cinnamic acid as animals sensitized to cinnamaldehyde reacted to the challenge with the three substances. Animals sensitized to cinnamyl alcohol reacted to cinnamyl alcohol and cinnamaldehyde, but not to cinnamic acid. Cinnamic acid did not sensitize guinea pigs. Compared to the challenge concentration for cinnamaldehyde, approximately a 15 times higher concentration of cinnamyl alcohol and a 25 times higher concentration of cinnamic acid were required to give positive reactions in animals sensitized to cinnamaldehyde. This could not be explained by differences in permeability properties, as the penetration profiles of the three substances through guinea pig skin in vitro showed permeability coefficients of the same order of magnitude under the test conditions. The study suggests that cinnamaldehyde is the "true" allergen, while cinnamyl alcohol and cinnamic acid are transformed in the skin to cinnamaldehyde, before contact allergic reactions can occur.

Affinity cytotoxicity with an alcohol dehydrogenase-antibody conjugate and allyl alcohol.

A potent new enzyme-antibody conjugate system for amplifying cytotoxicity was tested in a well-defined model of hapten [2,4,6-trinitrophenyl (TNP)]-substituted tumor cells (HEp2) and purified anti-hapten antibody. Brief treatment of TNP-HEp2 cells with low concentrations (0.05 to 0.74 micrograms/ml) of antihapten antibody-alcohol dehydrogenase conjugate (Ab-ADH) followed by culture in complement-free medium containing nicotinamide adenine dinucleotide and allyl alcohol or 2-fluoroethanol resulted in 15 to 90% cell killing as measured by 5-[125l]iodo'-2-deoxyuridine uptake assay. The importance of the complete enzyme system was indicated by reduced or absent cytotoxicity if Ab-ADH, nicotinamide adenine dinucleotide, or allyl alcohol (or 2-fluorethanol) were omitted. Immunological specificity of the Ab-ADH was demonstrated by reduced or absent cytotoxicity when: (a) HEp2 cells were not coated with TNP; (b) Ab-ADH binding onto TNP-cells was blocked by free hapten (2,4-dinitrophenyllysine); or (c) unconjugated alcohol dehydrogenase and anti-TNP purified IgG anti-2,4,6-trinitrophenyl antibody with NAD+ and allyl alcohol or anti-TNP antibody with complement were used.

The evaluation of hypersensitivity tests in cattle after foot-and-mouth disease vaccination.

The response to passive cutaneous anaphylaxis, dermal hypersensitivity and intravenous provocation tests has been compared in 30, 40, 31 and 24 cattle injected with foot-and-mouth disease vaccine 0, 1, 2 and 3 times respectively, using vaccine components and other substances as test materials. Reaginic antibodies demonstrated by passive cutaneous anaphylaxis in goats, were directed against BHK 21 cell extracts (20), hydroxypropylmethylcellulose (3) and an unidentified vaccine component (3), and distributed in 0, 5, 19 and 75 per cent of the cattle vaccinated 0, 1, 2 and 3 times. None of the animals showed clinical signs of allergy after vaccination. When BHK 21 cell extract was injected intradermally a significant correlation was noted between the development of large weals and the presence of reagins although the size of the weals was not correlated with the reagin titres. In the case of hydroxypropylmethylcellulose a similar trend was evident. The majority of cattle with large dermal weals possessed reagins but the number of reactions was too small for statistical evaluation. Dermal reactions to sodium penicillin, sodium carboxymethylcellulose, saponin and whole vaccine occurred in both unvaccinated and vaccinated cattle but BHK 21 cell lysate and normal bovine serum provoked weals which increased in frequency according to the number of vaccinations experienced. Intravenous hydroxypropylmethylcellulose elicited a response in all the animals previously injected with certain batches of vaccine but cell extract intravenously produced a clinical response in half the tested animals which was uncorrelated with the results of the passive cutaneous anaphylaxis or dermal hypersensitivity tests.