Allergenic component of a liverwort: a sesquiterpene lactone.

Frullania spp. (Hepaticae, Jungermanniales) are agents of allergies. Extraction and fractionation of Frullania tamarisci has given, as the only allergenic component isolated, a levorotatory crystalline sutbstance, the structure of which is demonstrated. It is a sesquiterpene lactone. The racemic (+/-) form is isolated from a mixed sample of Frullania tamarisci and Frullania dilatata; the dextrorotatory form, from Frullania dilatata. The observed allergenic properties are shared by some other-sesquiterpene lactones.

Modulation of suppressor mechanisms in allergic contact dermatitis: 2. Inhibition of suppressor T-lymphocytes by Corynebacterium parvum.

Pretreatment of BALB/c mice with Corynebacterium parvum inhibited the induction of tolerance to the contact sensitizing agent 2,4-dinitrofluorobenzene induced by intravenous injection of DNBSO3. The suppressive effect on tolerance induction has further been analyzed by adoptive transfer experiments. Injection of C. parvum intraperitoneally (0.7-2.8 mg/mouse) before injection of the tolergen inhibited the generation of T-suppressor cells as shown by transfer of spleen cells from the tolerized donor to naive recipients. Pretreatment of the recipients of the suppressor T-cells from tolerized animals with C. parvum also inhibited the function of these cells in the recipient animals. Time-kinetic experiments suggested that more than one mechanism appeared to be responsible for the tolerance induced by DNBSO3; C. parvum (probably via activated macrophages) suppressed tolerance which is mediated by T-suppressor lymphocytes. These results suggest that T-suppressor lymphocytes may--similarly as T-helper cells--be modulated by an activated monocytic-phagocytic system.

Immunomodulation in mice by Bacillus megaterium and its dependence on culture conditions.

Mice pretreated with Bacillus megaterium ATCC 33085 grown on TSA medium developed a significant increase in primary antibody response to SRBC. Conversely, pretreatment with a spore suspension harvested from nutrient Agar medium decreased this antibody response. A suspension of organisms grown on a defined, phosphorus-deficient medium (P-Medium) had no effect. Otherwise, only the spore suspension was able to enhance the contact sensitivity to dinitrofluorobenzene. Peritoneal leucocyte numbers were increased by inoculation with both TSA-cultured bacteria and the spore suspension, but not by P-Medium-cultured bacteria. Administration of both the spore suspension and P-Medium-cultured bacteria decreased the in vitro phagocytosis by peritoneal adherent cells. These immunomodulator properties are discussed in relation to characteristics of the strain tested.

Contact dermatitis due to nitroglycerin ointment.

Topical nitroglycerin ointment is among the most effective long-acting vasodilators currently available. We report two cases of contact dermatitis in which patch testing showed allergy to nitroglycerin-containing compounds. The severity of this dermatitis necessitated the discontinuation of topical nitroglycerin therapy in both patients. A potent corticosteroid cream applied once to previous nitroglycerin application sites prevented or minimized this dermatitis and enabled continuation of topical nitroglycerin therapy. Contact dermatitis due to topical nitroglycerin preparations may be more common than is presently realized.

Allergic contact dermatitis from sunscreen preparations complicating photodermatitis.

Two men with known histories of photosensitivity had apparent exacerbations of their dermatoses. Patch-testing showed the presence of allergic contact sensitivity to the sunscreens that they were using. The clinical distribution patterns of adverse reactions to sunscreens naturally simulate sun-induced reactions, thus providing clinical problems that require evaluation by both patch and photo-patch tests. These findings emphasize that allergic contact or photo-contact dermatitis from sunscreens that are used for prophylaxis of photodermatitis can actually complicate or aggravate the preexisting state of photodermatitis for which the sunscreens are prescribed.

A new method for obtaining viable cells from dermal infiltrates. A study on 2,4 dinitrochlorobenzene induced contact dermatitis.

Experimental contact dermatitis has been induced in 2,4 dinitrochlorobenzene (DNCB) sensitized guinea pigs. The developing dermal infiltrate was excised and the infiltrating cells were obtained by mechanical extraction alone as well as by the combination with collagenase and elastase treatment. The most viable cells appeared in the elastase and mechanically extracted samples and the least in those subjected to mechanical treatment alone. The most cells in the enzyme-treated samples were present 24 h after re-exposure of the sensitized animals to DNCB consisting mainly of lymphocytes and of polymorphonuclear granulocytes. The optimum conditions for the action of enzymes including optimum duration of the treatment, buffer milieu, aspecific proteolytic effect on foreign substrate and action on T and B cell receptors have been elaborated. It was concluded that 80 min of collagenase treatment with gentle mechanical extraction under specified conditions does not affect any measurable immunologic properties of the liberated cells resulting in the second best yield. A comparison of these data with earlier reports and their significance is being discussed.

Delayed-type skin reaction to 2,4-dinitrophenylated epidermal cells in guinea pigs with contact sensitivity to 2,4-dinitrochlorobenzene.

Contact sensitivity (CS) induced by hapten has been thought to be analogous to delayed-type hypersensitivity, such as the Mantoux reaction, because of outstanding similarities between the two phenomena. It can be suggested that animals with CS respond also to intradermal injection of the conjugate of hapten and protein as well as to epicutaneous application of hapten. However, evidence against this has been reported. In the present experiments, delayed-type skin reaction (DSR) was successfully obtained in JY1 strain guinea pigs sensitized by painting the skin with 2,4-dinitrochlorobenzene using in vitro dinitrophenylated epidermal cell suspension (DNP-EC) as antigen for a delayed intradermal test. The experiment using anti-Ia alloantiserum and complement showed that the elicitation of DSR is due to the presence of Ia-positive cells (presumably Langerhans cells) among DNP-ECs. The delayed intradermal test with the conjugates such as haptenated ECs in the animals with CS is considered to be an experimentally useful way of analysing the antigen in the sensitivity.

Chemically-induced delayed hypersensitivity in the cat.

A technique to evaluate the cell mediated immune response in cats by the induction of delayed-type hypersensitivity to the strong contact sensitizer, 1-chloro, 2-4 dinitrobenzene is described. Following topical sensitization with this agent, challenge was done on the cats ear. Ear thickness measurements, the kinetics of the response and histopathologic examination of the tissue were used to assess this delayed-type hypersensitivity reaction. Based on the results it is shown that allergic contact dermatitis can be experimentally induced in the cat.

Dermatitis in rubber manufacturing industries.

This review describes the history of rubber technology and the manufacturing techniques used in rubber manufacturing industries. The important aspects of the acquisition of allergic and irritant contact dermatitis within the industry are presented for the reader.

Side effects in the treatment of herpetic keratitis.

Various side effects due to antiherpetic drugs observed in the last ten years in our department were studied. A total of 132 patients were treated with 5-iodo-2'-deoxyuridine (IDU), 69 with trifluorothymidine (F3T), 58 with acyclovir (ACV) and 33 with adenine arabinoside (ara-A). Patch tests were routinely done when patients exhibited contact dermatitis. Of the patients treated with IDU, 3 (2.3%) showed contact dermatitis, 2 (1.5%) follicular conjunctivitis and 1 (0.8%) punctate keratopathy. Of the patients treated with F3T, 7 (10.1%) exhibited contact dermatitis and 1 (1.4%) follicular conjunctivitis. In the group treated with ACV, 2 (3.4%) patients showed punctate keratopathy. The patients who received ara-A did not show any side effects. We found that F3T caused contact dermatitis more frequently in Japanese people than Europeans. These side effects were resolved by switching to another anti-herpetic drug without the occurrence of cross-allergy. Therefore, switching to another drug is strongly recommended when patients exhibit side effects in the treatment of herpetic keratitis. Other complications were allergy to atropine and to drug preservative.

Allergic contact dermatitis from oxygen cannulas.

A patient experienced allergic contact dermatitis on two occasions two months apart as a result of wearing the same brand of polyvinyl chloride oxygen cannula. In one instance the cannula was removed and not replaced, as continuing oxygen was unnecessary; on the other occasion the original cannula was replaced by a cannula of another brand. In both cases the dermatitis disappeared after removal of the original cannula. The reaction was probably to a resin remaining in the polyvinyl chloride after the curing process in the manufacture of the plastic from which the cannula was made. Allergic reactions to plastics have been documented in other medical products but have not previously been reported in respiratory therapy plastic appliances. Because of variability in residual resins in different brands and batches of plastics, and because of varying individual sensitivity, therapists and others should be alert to the possibility of allergic contact dermatitis from respiratory therapy devices.

Dermatitis artefacta.

A case of dermatitis artefacta is reported. The lesions were shown to contain silver and were probably caused by a silver nitrate caustic stick. The patient never admitted to having produced these lesions.

Skin pathology following epicutaneous exposure to seven organic solvents.

1,1,1,-Trichloroethane, benzene, trichloroethylene, tetrachloroethylene, dibromoethane, 1,2-dichloroethane, and 1,1,2,2-tetrachloroethane were applied to the skin of guinea-pigs for histopathological studies. Biopsies taken at different times of exposure showed the presence of karyopyknosis for all solvents tested; 1,1,1-trichloroethane, benzene, trichloroethylene, and tetrachloroethylene showed karyolysis; 1,1,1-trichloroethane, benzene, trichloroethylene, tetrachloroethylene, and dichloroethane induced spongiosis. All solvents, except 1,1,2,2-tetrachloroethane, produced junctional separation. Pseudoeosinophilic infiltration occurred for all solvents, except for 1,2-dichloroethane. The results are discussed in terms of occupational hazards and in relation to parallel studies on blood uptake and systemic toxicity at epicutaneous administration.

Effect of protective agent against lipid-solvent-induced damages. Ultrastructural and scanning electron microscopical study of human epidermis.

The ultrastructural and relief (cyto-architectural) changes of human epidermis following exposure to a protective gel and acetone or kerosene were studied in healthy volunteers. Topical applications of acetone and kerosene on unprotected skin produced cell damage and a disorganized pattern in the upper layers of epidermis. The ultrastructural changes following acetone consisted of large paranuclear vacuoles, swollen mitochondria, and clumped tonofilaments. Severe disorganization with intense cytolysis and enlarged intercellular spaces occurred after exposure to kerosene. Scanning electron microscopy revealed edematous connified cells (corneocytes) following acetone exposure, whereas kerosene induced the occurrence of large lacunae in the swollen corneocytes. The application of a protective agent prior to solvent exposure substantially reduced the ultrastructural and relief changes of epidermal cells.