articles+ search results

Dermatology, Dermatologie, Immunology, immunopathology, allergology, Immunologie, immunopathologie, allergologie, Sciences biologiques et medicales, Biological and medical sciences, Sciences medicales, Medical sciences, Toxicologie, Toxicology, Toxicologie des produits chimiques et industriels. Maladies professionnelles dues aux toxiques, Chemical and industrial products toxicology. Toxic occupational diseases, Composés organiques divers, Various organic compounds, Immunopathologie, Immunopathology, Maladies allergiques, Allergic diseases, Dermatoses allergiques. Allergie aux piqûres d'insectes, Skin allergic diseases. Stinging insect allergies, Immunopathologie, Immunopathology, Inmunopatología, Mammalia, Peau pathologie, Skin disease, Piel patología, Rodentia, Vertebrata, Allergie, Allergy, Alergia, Allergénicité, Allergenicity, Alergenicidad, Animal, Cobaye, Guinea pig, Cobayo, Colophane, Colophony, Colofonia, Dermatite contact, Contact dermatitis, Dermatitis de contacto, Dissolution, Disolución, Etude comparative, Comparative study, Estudio comparativo, Phase amorphe, Amorphous phase, Fase amorfa, Phase cristalline, Crystalline phase, Fase cristalina, Relation propriété physicochimique activité, Physicochemical properties activity relationship, Relación propiedad fisicoquímica actividad, Toxicité, Toxicity, Toxicidad, Voie externe, Topical administration, and Vía externa

Endo-maleopimaric acid (MPA) is a contact allergen formed when colophonium is modified with maleic anhydride or fumaric acid. Previous patch testing showed a higher allergic response to petrolatum (pet.) preparations of MPA in amorphous form compared to MPA in crystalline form. In the present study, the impact of the physical form of MPA on the allergic response was investigated. Since the amorphous form is difficult to standardize, crystalline MPA mechanically incorporated or dissolved in pet. was used. A lower eliciting capacity was obtained from crystalline MPA, compared to that obtained from dissolved MPA, in guinea pigs intradermally induced with MPA. Using 3H-MPA a 3X difference in the dissolution into synthetic sweat from MPA dissolved in pet., compared to MPA mechanically incorporated, was demonstrated. A difference in bio-availability between dissolved and crystalline MPA could therefore be assumed. Crystalline MPA had a low sensitizing capacity compared to that seen for amorphous MPA in previous studies. The amorphous form of MPA is likely to have a larger surface area than crystalline MPA, with less ordered molecules, resulting in a higher dissolution rate and a greater bio-availability. Modified colophonium exists as amorphous solids and as viscous liquids. Thus, exposure will probably be to non-crystalline MPA and cases of contact allergy could be overlooked when screening with crystalline MPA.

Dermatology, Dermatologie, Immunology, immunopathology, allergology, Immunologie, immunopathologie, allergologie, Sciences biologiques et medicales, Biological and medical sciences, Sciences medicales, Medical sciences, Immunopathologie, Immunopathology, Maladies allergiques, Allergic diseases, Dermatoses allergiques. Allergie aux piqûres d'insectes, Skin allergic diseases. Stinging insect allergies, Immunopathologie, Immunopathology, Inmunopatología, Peau pathologie, Skin disease, Piel patología, Allergie, Allergy, Alergia, Animal, Antigène, Antigen, Antígeno, Cétone, Ketone, Cetona, Dermatite contact, Contact dermatitis, Dermatitis de contacto, Haptène, Hapten, Hapteno, Homme, Human, Hombre, Relation structure activité, Structure activity relation, Relación estructura actividad, Réaction croisée, Cross reaction, Reacción cruzada, Réactivité, Reactivity, Reactividad, Sensibilisation, Sensitization, Sensibilización, Structure 3 dimensions, Three dimensional structure, Estructura 3 dimensiones, p-Mentha-6,8-dién-2-one, p-Mentha-6,8-dien-2-one, and 6,8-p-Mentadieno-2-ona

In the present study, the mechanism for the antigen formation of a, β-unsaturated ketones was investigated. A series of analogues of carvone ((5R)-5-isopropenyl-2-methyl-2-cyclohexenone) with altered chemical reactivity and with retained overall structure or with retained reactivity and altered three-dimensional structure were synthesized. These analogues were tested for cross-reactivity in carvone-sensitized animals. Cross-reactivity was observed for analogue 3 ((5R)-5-isopropyl-2-methyl-2-cyclohexen-1-one). No cross-reactions were observed for analogues 1 ( (2. /?, 57?) -5-isopropenyl-2-methyl cyclohexanone) and 4 ((5R)-2,3-dimethyl-5-isopropenyl-2-cyclohexene-1-one). Both those compounds also failed to induce sensitization. These findings demonstrate that a, β-unsaturated ketones form antigens after a nucleophilic attack at the β-carbon with soft nucleophiles such as thiol in cysteine and not with the formation of a Schiff's base after a nucleophilic attack at the carbonyl carbon with nitrogen nucleophiles. Furthermore, no cross-reactivity was observed between R- and S-carvone indicating the importance of the 3-dimensional structure of haptens (and antigens) in T-cell recognition. The analogues were also tested for cross-reactivity on patients allergic to carvone. The results from the animal study were confirmed.

ABIETIC acid, GUMS & resins, CHROMATOGRAPHIC analysis, GUINEA pigs, ESTERIFICATION, and MAGNETIC resonance

To investigate whether esterification of rosin with polyalcohols changes its allergenic potential, abietic acid, the main component of rosin, was esterified with glycerol at high temperature. The major product formed was isolated and identified, using nuclear magnetic resonance (NMR), infra-red (IR) and mass spectrometry (MS) analyses, as glyceryl triabietate (GTA), an ester between one glycerol molecule and 3 abietic acid molecules. According to animal experiments GTA was not allergenic and no cross-reactivity was seen to allergens in unmodified rosin. When testing patients allergic to unmodified rosin, no reactions were found to GTA. Some of the patients reacted to glycerol- and pentaerythritol-esterified rosins. According to HPLC analyses, these esterified rosins still contained unmodified material to which the patients may have reacted. It seems that the esterification of rosin with polyalcohols such as glycerol reduces its allergenic activity, possibly because of the formation of much larger molecules with reduced bioavailability. However, making methyl esters of rosin causes little alteration in the molecular weights of the components and, when unmodified and methylated rosin were tested in patients, we saw no difference between the 2 forms. [ABSTRACT FROM AUTHOR]

GUMS & resins, PATIENTS, ZINC, ADHESIVES, ABIETIC acid, and ALLERGIES

Adhesives anti bandages containing zinc oxide (ZnO) and rosin are often used for treatment of ulcers. The aim of this work was to study a possible inhibitory effect of ZnO on the elicitation of allergic contact reactions to rosin and to determine whether such an effect might be clue to the formation of zinc resinates. Patch testing in rosin-sensitive patients was performed with mixes of ZnO and rosin. The eliciting capacities of one mix in which zinc resinates might be formed and another mix in which the formation of zinc resinates was prevented, were compared to the eliciting capacity of rosin alone. If a reduction of the allergic response was observed for the mix in which zinc resinates might form and if no reduction was observed for the mix in which formation of zinc resinates was prevented, this would support the hypothesis that the reduction in eliciting capacity was due to formation of zinc resinates. However, we could not see any difference in eliciting capacity when comparing the 2 mixes with a test preparation of rosin. Commercial adhesives (bandages) containing ZnO and rosin were patch tested in 7 rosin-sensitive patients. The concentration of abietic acid in the adhesives was determined with HPLC. Abietic acid was detected in all but one of those declared to contain rosin. The patients reacted to the adhesives in which abietic acid was detected. For rosin-sensitive persons, the addition of ZnO to rosin-containing adhesives cannot he regarded as an appropriate measure to inhibit the elicitation of allergic reactions. [ABSTRACT FROM AUTHOR]

GUMS & resins, ALLERGIES, COLOPHONS, GLYCERYL ethers, PATIENTS, and NUCLEAR magnetic resonance

In the esterification of rosin with glycerol, the main compound formed, glyceryl triabietate, shows low allergenic activity. In this study, compounds formed in smaller amounts, when abietic add (main component in rosin) was esterified with glycerol, were identified as glyceryl-1-monoabietate (GMA), glyceryl-1,2-diabietate (GDA,1,2) and glycery-1,3-diabietate (GDA1,3), using nuclear magnetic resonance (NMR), infra-red (IR) and mass spectrometry (MS) analyses. According to animal experiments, OMA was a contact allergen. No cross-reactivity was seen to allergens in unmodified rosin. Some patients allergic to unmodified rosin reacted when tested with GMA. No reactions were seen to the 2 diabietates. Some patients also reacted to commercial glycerol-modified rosins. OMA together with unmodified abietic acid were identified in these rosin samples. The reactions seen in rosin-sensitive patients to commercial glycerol-esterified rosins probably derive from the unmodified material still present in the product, but could also be the result of OMA obtained from the glycerol derivatization. [ABSTRACT FROM AUTHOR]

GUMS & resins, ESTERS, PAPER sizing, PRINTING ink, ALLERGENS, and ESTERIFICATION

The maleopimaric acid is the main component of modified colophony rosin. The main use of maleic-modified rosins is in paper size, while its esters are mainly used in printing inks. The article examines the sensitizing capacity of maleopimaric acid. The compound was synthesized and its structure was determined. Maleleopimaric acid was found to be very potent sensitizer comparable with the strongest allergen isolated from unmodified colophony of the gum rosin type. It is concluded that the modification of colophony might form new potent allergens not found in unmodified colophony.