Chronic Toxoplasmosis Modulates the Induction of Contact Hypersensitivity by TNCB in Mouse Model

Mouse models of chronic toxoplasmosis and atopic dermatitis (AD) were combined to clarify the effect of opportunistic Toxoplasma gondii infection on the development of AD. AD was induced as a chronic contact hypersensitivity (CHS) with repeated challenge of 2,4,6-trinitro-1-chlorobenzene (TNCB) on the dorsal skin of mice. TNCB induced skin thickness increases in both normal and toxoplasmic mice. The changing patterns were different from the sigmoidal which saturated at 20 days in normal mice to the convex saturated at 12 days in toxoplasmic mice with the crossing at 18 days. Compared to normal mice, toxoplasmic mice presented CHS more severely in earlier times and then moderately in later times. These data suggest that host immune modification by T. gondii infection enhances CHS in early times of atopic stimulation but soothes the reaction of CHS in later times in mouse model.

Effects of cyclosporin A treatment on the pathogenesis of avian leukosis virus subgroup J infection in broiler chickens with Marek's disease virus exposure

In this study, we investigated the effects of T-cell suppression on the pathogenesis of subgroup J avian leukosis virus (ALV-J). Chickens were treated with cyclosporin A (CSP) 50 mg/Kg body weight or a corresponding volume of olive oil per every three days after hatching until the end of experiment. Some of the chickens from each treatment group were infected with an isolate of ALV-J, ADOL-7501, at 2 weeks of age. The effects of viral infection were compared to uninfected birds in same treatment group. Intramuscular injection of CSP induced significant T-cell specific immunosuppression determined by decreased cutaneous basophilic hypersensitivity response and decreased lymphocyte mitogenic activity using concanavalin A. Most of the chickens examined had Marek's disease virus infection prior to 3 weeks of age. The percentage of antibody-positive birds and antibody titers were similar in infected chickens between both treatment groups. The ratio of viremic chickens was significantly higher in CSP treated group than that of the Oil treated group. Microscopically, one CSP treated chicken had a nephroblastoma at 10 weeks post infection. At 7 and 10 weeks post-infection, more chickens had myeloid cell infiltrations in multiple organs including heart, liver and occasionally lung. Expression of ALV-J viral antigen determined by immunohistochemical staining was significantly higher in CSP treated chickens than Oil treated chickens at 10 weeks post-infection. This study indicated that chemically-induced T-cell suppression may enhance pathogenicity of the AVL-J virus in broilers.

Potencial de sensibilizaçäo cutânea de duas formulaçöes de um creme básico em pacientes com dermatoses alérgicas / Skin sensitization potential of two formulas of a basic cream in patients with allergic dermatoses

Objetivos. Avaliar se a formulação de um crème básico cosmético (Crème Universal© acrescida de uma essência A ou B aumentaria o potencial de sensibilização em uma população suscetível. Métodos: Estudo multicêntrico, comparativo, simples-cego, randomizado, conduzido em 179 pacientes adultos portadores de pele xerótica e dermatite de contato e/ou atópica, distribuídos em 2 grupos parcelados A e B que utilizaram crème com essência A ou B respectivamente. Após 14 dias de uso contínuo de crème todos os pacientes foram submetidos a teste de contato com uma bateria padrão e mais os componentes do crème. Resultados: O teste de contato foi positivo para algum dos componentes do crème em apenas três (1,7 por cento) casos do total de pacientes e o índice geral de reação adversa foi de 8 por cento no Grupo A e 7,6 por cento no Grupo B. Não houve diferença estatisticamente significantes entre os dois grupos. Conlusão: A utilização do Crème Universal© associado a uma essência A ou B resultou num índice de sensibilização extremamente baixo numa população especialmente susceptível. Não houve diferença de reações com o acréscimo de essência A ou B.

Pruebas cutáneas a diferentes especies de ácaros en niños asmaticos de la Ciudad de México / A comparative study of effects adverse a contrast ionic iodine in preventive medication

Con la finalidad de deterctar la sensibilidad a otras especies de ácaros, además de Dermatophagoides farine (Df), Dermatophagoides pteronyssinus (Dp) se realizaron pruebas cutáneas a cien niños habitantes de la Ciudad de México. Estas se hicieron en la cara anterior de antebrazos, mediante Multitest con extractos glicerinados. Fueron 34 niñas y 66 niños, entre cuatro y 14 años de edad (promedio de 9.1), con historia de asma leve o moderada, de dos meses a 12 años de evolución, Dp resultó positivo en 96, Df en 80, Euroglyphus maynei en 41, Chortoplyphus en 22 Blomia tropicalis en 17, Tyrophagus putrescentiae y Glycyphagus en 12, Acarus siro, Lepidoglyphus destructor y Gophieria en 7. La hipersensibilidad a todas las especies fue común. A pesar de saberse que existe reacción cruzada entre especies, se han encontrado alergenos específicos de especie, lo que podría dar importancia clínica a estos diagnósticos y sus tratamientos

Dermatitis por contacto alérgica a la etilenimina en la industria farmacéutica veterinaria / Allergic contact dermatitis to ethylenimine in the pharmaceutical veterinary industry

Se estudiaron cuatros operarios sobre un total de diez afectados, que trabajaban en una empresa de productos farmacéuticos para veterinaria que manipulaban etilenimina para la elaboración de vacuna antiaftosa. El objeto del presente trabajo fue determinar si la E. es el agente causal en diez operarios afectados por dermitis por contacto alérgica en una industria que la emplea y, en caso de confirmar esta participación, indicar las medidas de profilaxis respectiva

De Hahnemann a la inmunologia actual / From Hahnemann to the actual immunology

Los conocimientos actuales sobre inmunologia, han llegado a las mismas conclusiones que el Dr. Samuel Hahnemann en 1813 expreso sobre la dermatitis por contacto y el Rhus toxicodendron. Los inmunologos, al estudiar los efectos de diferentes haptenos capaces de producir dermatitis por contacto, entre los que esta el Rhus toxicodendron, pudieron constatar que la inmunidad celular es la directamente responsable de la patologia manifiestal; asimismo, han demonstrado que los haptenos administrados por via oral a pequenas dosis provocan la proliferacion de linfocitos T supresores que limitan y regulan la respuesta celular. Es importante hacer notar que el Dr. Hahnemann desarrollo dentro de su terapeutica el uso del Rhus toxicodendron y que este medicamento se emplea en terapia homeopatica actual para curar padecimientos en los que la inmunidad celular es la responsable de las lesiones tisulares como son algunos cuadros de dermatitis por contacto, tuberculosis, enfermedades virales y artritis reumatoide. Los inmunologos han concluido conceptos que los llevan a la terapia homeopatica en lo que se refiere a la dermatitis por contacto; quedando por comprobar experimentalmente si en los otros padecimientos en donde se usa el Rhus toxicodendron tambien intervienen los linfocitos T supresores para impedir el dano a los tejidos

Time course of contact hypersensitivity to DNFB and histologic findings in mice

This experiment pursued the time course of contact hypersensitivity to 2,4-dinitro-1-fluorobenzene (DNFB) and histologic changes of the cutaneous reaction in mice. The contact hypersensitivity reached a maximum 4 days after sensitization (96.9 +/- 6.7% vs. 22.7 +/- 1.3% in control) and persisted for 3 weeks. The cutaneous hypersensitivity reaction showed peak reactivity at 24 hr after challenge (96.2 +/- 4.7% vs. 11.5 +/- 1.7% in control), and persisted up to 96 hr (13.2 +/- 2.1%). Prime histologic changes observed in this experiment were the exocytosis of lymphoid cells and epidermal thickening which appeared at 20 hr after challenge. Edema, vasodilatation and increased mast cells were observed within the dermis at 4-8 hr. However, edema and vasodilatation disappeared gradually, but numbers of mast cell increased up to 96 hr. The dermal infiltrates were maximum at the 28-72 hr after challenge.