Hepatic lesions caused by excretory and secretory products of Ascaris lumbricoides in golden hamster.

OBJECTIVE: To ascertain the role of excretory and secretory (ES) products of Ascaris lumbricoides in liver damage. METHODS: The ES products of A lumbricoides were collected in vitro and their SDS-PAGE analysis was done. Feeding and subcutaneous injection of ES products were done in hamsters. Estimation of serum proteins, alkaline phosphatase and alanine aminotransferase and histology of liver were carried out. Control animal experiments were done concurrently. RESULTS: The ES products of A lumbricoides contained several proteins ranging in molecular weight from 14 to 205 Kd. Prolonged feeding of ES products caused elevation of ALT and amyloid deposition in the liver, whereas short term feeding or subcutaneous challenge caused focal cell necrosis and granuloma formation in the liver. CONCLUSION: ES products of A lumbricoides can produce liver damage.

Suppression of the IgE antibody response by Ascaris suum components: effect of x-irradiation

The effect of X-irradiation on the supperession of IgE antibody responses induced by some of the Ascaris suum (ASC) components was analyzed in mice (7-week old A?Sn females). Treatment with 300 R 24h before immunization with 50 *g OVA and 200 *g ASC suppressive components abolished the damping effect on ati-OVA IgE antibody levels. The same effect was observed on the anti-ASC IgE antibody response obtained in mice injected with 200 *g ASC immunogenic plus 200 *g ASC suppressive components. Moreover, the failure of suppressive components to induce an IGE anti-ASC antibody response on their own was also abolished by X-irradiation. These results indicate that the suppressive components are able to elicit an IgE antibody response, but simultaneously activate a regulatory mechanism which suppressive both the homologous (anti-ASC) and heterologous (anti-OVA) antibody formation

Further characterization of ascaris suum component(s) with supressive activity on the IgE antibody response

In order to characterize the component(s) of Ascaris suum reponsible for damping of the IgE antibody production we demonstrated that the extract incubated in sodium acetate buffer, pH 4.5, maintained its suppressive effect and the same protein banding pattern by SDS-PAGE. Elimination of the lipoprotein components of the extract also left its damping properties unchanged. SDS-PAGE of the lipoprotein-free extract revealed practically the same pattern as shown by the whole extract, except for the high molecular weight polupeptides. These results indicate that the suppressive component(s) of A. suum did not precipitate and retained their activity at low pH. In addition, they appear not to be lipoproteins

Ascaris y alergía / Ascaris and alergy

Existen dos situaciones en las cuales es importante medir los niveles séricos de la IgE en las enfermedades alérgicas y en las parasitosis helmínticas. En este estudio fueron modificados ciertos aspectos en el procesamiento convencional. Primero se sometió a prueba el uso de discos de nitrocelulosa a los cuales se fijan proteínas y otros antígenos, sin la necesidad de una activación previa. Por otro lado, se utilizó un sistema ELISA (prueba inmunoenzimática en lugar de los marcadores radiactivos. Se establecieron comparaciones entre sujetos alérgicos y no alérgicos, y los resultados mostraron que las características de las reacciones pulmonares inducidas fueron del tipo alérgico, siendo reversibles por la inhalación de broncodilatadores. Hubo 4 pacientes asmáticos, en los cuales la inhalación del extracto no produjo ninguna reacción pulmonar, dichos resultados sugieren que las infecciones por helmintos intestinales, particularmente ascaris, no deben ser ignoradas como posibles agentes etiológicos del asma en el ambiente tropical

Alergia y parásitos: una asociación disociable / Alergy and parasities: an asociation dissoluble

Estudios epidemiológicos han intentado evaluar como las infecciones parasitarias por helmintos puede modular la respuesta alérgica, generando importantes controversias. En este estudio se observó una significativa prevalencia de enfermedades alérgicas (rinitis y asma bronquial en individuos infectados por helmintos)

Murine delayed type hypersensitivity is suppressed by Ascaris suum extract

We studied the suppressive effect of an Ascaris suum extract on delayed-type hypersensitivity (DTH) reactions to ovalbumin (OVA) and to Bacillus Calmette-Guerin (BCG). The ability of mice to develop DTH reactions to both antigens was suppressed when an immunizing dose of the antigen was given subcutaneously together with the Ascaris extract. Partial or complete suppression of the response to OVA was obtained by the use of 400 por 1000 microng of Ascaris extract, respectively. The response to BCG, on the other hand, was totally suppressed by 400 microng of extract

Suppression of IgE antibody production by Ascaris suum extract: characterization of suppressive component(S)

Partial characterization ot the suppressive component(s) of A. suum extract that is (are) responsible for damping production of IgE antibody to ovalbumin was performed by physical and chemical methods. Digestion of the whole extract with trypsin and chymotrypsin completely abolished the suppressive activity. Oxidation with sodium metaperiodate or heating at 56-C, however, had no effect. These results indicate that the integrity of heat-stable proteins(s) present in the crude extract is essential for its suppressive effect. In addition, the carbohydrate moiety does not seem to play an important role in this effect

Infestación por Ascaris: una posible explicación para los altos niveles de IgG anti-A observados en la población venezolana / Ascaris infestation: a possible explanation for the high levels of IgG anti-A found in Venezuela populations

Hemos investigado los niveles de IgG anti-A y los de IgG anti-Ascaris en grupos de nivel socioeconómico alto (NSEA) con un bajo grado de infestación por Ascaris (5,6%), de nivel socioeconómico bajo (NSEB) con un 47,6% por ciento de infestación y de indígenas del Amazonas con un nivel de infestación del 67,5 por ciento. Los títulos de IgG anti-A y anti-B se determinaron por hemaglutinación simple y por la técnica indirecta de Coombs, y los de IgG anti-Ascaris (en su forma adulta) por una técnica inmunoenzimática. Los títulos de IgG anti-A obtenidos por la prueba de Coombs, fueron significativamente mayores en el grupo indígena (media geométrica 1833) y en el de NSEB (659) en relación al grupo de NSEA (225). Aunque hubo una asociación positiva entre la frecuencia de infestación por Ascaris y los niveles de IgG anti-A, al comparar individualmente los títulos de IgG anti-A con los de IgG anti-Ascaris no se obtuvo correlación. Sin embargo, estos resultados no descartan la posibilidad de que componentes de otros estadios del parásito presenten reactividad cruzada con el antígeno A

Serologic differentiation of larval Toxocara and Ascaris.

Antigenic extracts of adult and larval T. canis and A. suum have been used in microgel double diffusion technique to differentiate antibodies produced in animals, experimentally infected with these parasites. Antigenic extracts from adult Ascaris reacted with the sera from animals infected with A. suum but the extracts from adult Toxocara failed to react or reacted feebly with the sera from animals infected with T. canis. Interestingly the antigenic extract from adult Toxocara reacted with the sera from animals infected with Ascaris. The antigens extracted from embryonated eggs of both the worms reacted with anti-Toxocara larval serum but could not absorb all the specific antibodies in the interagel absorption test.

Serologic differentiation of adult Toxocara and Ascaris.

The antigenic analysis of Toxocara canis a causative agent of visceral larva migrans and Ascaris suum has been carried out. Agar gel double diffusion techniques and its modifications were employed to determine whether or not crude antigens, obtained from the adult parasites: (a) contained components unique for each, (b) could be used to differentiate the parasites serologically. Adult Toxocara canis and Ascanis suum antigens used in this study were found to contain several unique antigenic components. It was shown that antisera produced in rabbits artificially immunized against adult Ascaris and Toxocara could be specifically differentiated from each other by using intragel absorption test.