Introducción: El síndrome del intestino irritable (SII) es un trastorno digestivo funcional que afecta del 10 al 20% de la población general. Existen pocos estudios en Latinoamérica que muestren su prevalencia nacional, y en Venezuela no disponemos de investigación que reporte tan importante cifra. Materiales y métodos: Estudio multicéntrico, descriptivo, transversal, durante los meses abril y mayo del 2011. Se utilizó el cuestionario validado de la Fundación Roma, con quienes firmamos convenio como Servicio de Gastroenterología del Hospital Vargas de Caracas. Se seleccionaron al azar 15 estados, en cada uno un municipio, y de estos lugares como iglesias, centros comerciales, reuniones de Consejos Comunales, paradas de autobuses, etc. Los valores obtenidos fueron transcritos en una base de datos en Excel y procesados con EPIDAT 3.1. Resultados: De 1781 personas encuestadas, 299 presentaron criterios clínicos diagnósticos para SII de acuerdo a Roma III. La prevalencia nacional del SII fue de 16,80%, correspondiendo 81,6% a mujeres (244) y 18,4% a hombres (55). El grupo etario entre 38 y 47 años fue el más afectado (26,43%) y el subtipo mixto el más predominante. Conclusiones: La prevalencia del SII en la población adulta venezolana según los criterios de Roma III es de 16,80%.

Introduction: irritable bowel syndrome (IBS) is a functional digestive disorder that affects 10 to 20% of the general population. Few studies exist in Latin America that shows the national prevalence, and in Venezuela we don´t have investigation resources that support those numbers. Materials and methods: Multicenter study, descriptive, transversal, during the months April and May 2011. The validated Roma Foundation questionnaire was used. This Foundation authorized its use by the Service of Gastroenterology Hospital Vargas de Caracas. 15 states were randomly selected, in each state one municipality, and in those places as churches, shopping centers, comunity meeting, bus stops, etc. The values obtained were transcribed into a database in Excel and processed EPIDAT 3.1. Results: Of 1781 people encuested, 299 met the criteria for IBS according to Rome III. The national prevalence of IBS was 16.80%, with 81.6% women (244) and 18.4% men (55). The age group between 38 and 47 years was the most affected (26.43%) and the mix was the most predominant subtype. Conclusions: The prevalence of IBS in the Venezuelan adult population according to Rome III criteria is 16.80%.

We examined the ability of IgG anti-crotalic PLA2 to cross-react with Bothrops spp. venoms, from snakes found in the northeast of Argentina. Immunoblotting and ELISA tests showed that IgG anti-crotalic PLA2 recognize antigens of bothropic venoms. Indirect hemolytic activity tests showed that the quantity of antibodies that neutralized 50% of Crotalus durissus terrificus venom (ED50: 2.1 mg IgG anti-crotalic PLA2/100 µg of venom) were also able to neutralize venom from other snakes in the following proportion: 34% of B. alternatus, 18% of B. diporus and 12% of B. jararacussu. Likewise, direct PLA2 activity neutralization tests showed a similar cross-neutralization pattern including 56% of B. alternatus, 29% of B. diporus and 30% of B. jararacussu. In addition, in a myotoxic activity neutralization test, measured by plasma activity of creatine kinase, 35% of B. alternatus venom and 26% of B. diporus venom were neutralized, while no neutralization was detected with B. jararacussu venom. This study presents original data concerning cross-reactions between bothropic venoms from Argentina and IgG anti-crotalic PLA2. Our results suggest that anti-crotalic PLA2 antibodies should not be used to neutralize PLA2 activity of B. alternatus, B. diporus and especially B. jararacussu venoms; nor to enrich commercial antivenoms against these Bothrops species.

Crotalus durissus terrificus (C.d.t.) (South American rattlesnake) venom possesses myotoxic and neurotoxic activities, both of which are also expressed by crotoxin, the principal toxin of this venom. Crotoxin contains a basic phospholipase A2 (PLA2) and a non toxic acidic protein, crotapotin. We have produced and investigated the ability of IgG antibodies raised in rabbits against PLA2 to neutralize the lethality of the whole venom. PLA2 was isolated by gel filtration chromatography (Sephadex G-75). Specific antibodies were obtained by subcutaneous and intramuscular inoculation of PLA2 (700 µg) with Freund adjuvant. Groups of six mice (20 + 2 g) were inoculated with 0.5 ml i.p. of C. d. t. venom (4 µg) or a mixture of venom that had been preincubated with the desired volume of IgG antibodies. Mortality, recorded 24 and 48 h after inoculation, showed that IgG anti-PLA2 were more effective than anticrotalic serum in neutralizing the lethal activity. These results demonstrate that it could be possible to obtain an anti-venom made by specific antibodies with a high level of protection against the lethal component of C.d.t. venom, and/or the inclusion of these antibodies as a supplement in heterologous anti-venoms.

El veneno de Crotalus durissus terrificus (C.d.t.) (Cascabel de Sud América) posee actividad miotóxica y neurotóxica, actividades que también exhibe el complejo crotoxina, principal componente tóxico de este veneno. El complejo crotoxina está constituido por una fosfolipasa A2 básica (PLA2) y una proteína acídica no tóxica, el crotapotín. En este trabajo se estudió la capacidad neutralizante de anticuerpos IgG anti-PLA2 sobre la letalidad inducida por el veneno entero. El antígeno PLA2, fue aislado por cromatografía de filtración en gel (Sephadex G-75). Se inocularon conejos machos por vía subcutánea e intramuscular, con 700 µg de PLA2 y adyuvante para la obtención de anticuerpos específicos. La capacidad neutralizante del antisuero se analizó en ratones por inoculación con diluciones de veneno entero preincubado con un volumen adecuado de anticuerpos IgG anti-PLA2. Se inocularon ratones controles con 0.5 ml i.p. de veneno (4 µg.ml-1). El número de muertes fue contabilizado a las 24 y 48 h posteriores a la inoculación, demostrándose que la capacidad neutralizante de los anticuerpos IgG anti-PLA2 fue superior a la obtenida con el antiveneno crotálico. Los resultados obtenidos demuestran la potencial aplicación de antivenenos constituidos por anticuerpos específicos contra PLA2, y/o la inclusión de estos anticuerpos como suplementos en antivenenos polivalentes.

Anti-native DNA antibodies can be detected by indirect immunofluorescence assay with Crithidia luciliae, displaying an annular image due to a kinetoplast containing double stranded DNA. Other structures such as membrane, flagellum and basal corpuscle can be stained as well, showing what is called atypical fluorescent images. As C. luciliae belongs to the Trypanosomatidae family, which include the human pathogens Trypanosoma cruzi and Leishmania spp., it was considered that these atypical images could be caused by cross-reactions. Serological studies for Chagas’ disease were performed in 105 serum samples displaying atypical images. Sixty four percent of the samples from non endemic and 78.3% from endemic areas for Chagas’ disease showed fluorescence in both, membrane and flagellum (joint image). Fifty samples from normal blood donors and 57 samples from patients with conective tissue diseases were tested with C. luciliae. None of them presented the joint image except for two patients with lupus who were also chagasic. In addition, 54 samples from chagasic patients were studied and all of them presented the joint image. We also studied 46 samples from patients with leishmaniasis from whom 28 were co-infected with T. cruzi. The joint image was observed in 88.0% of the samples with leishmaniasis and in 89.3% of the co-infected samples. The results suggest that C. luciliae could be used as an economical, and of low risk, alternative substrate for the serological diagnosis of Chagas’ disease, even though it does not discriminate for Leishmania spp. infection. This study also suggests that whenever atypical images are observed in C. luciliae during the search for anti-DNA antibodies, it would be convenient to submit the patient to clinical and serological tests for the diagnosis of leishmaniosis and Chagas’ disease.

Los anticuerpos anti-ADN nativo pueden detectarse por inmunofluorescencia indirecta con Crithidia luciliae, observándose tinción fluorescente anular del kinetoplasto que contiene ADN de doble cadena. En algunos casos pueden observarse imágenes fluorescentes en flagelo, membrana y corpúsculo basal, consideradas atípicas. Como C. luciliae pertenece a la familia Trypanosomatidae, que incluye patógenos para el hombre como Trypanosoma cruzi y Leishmaniaspp., se consideró que las imágenes atípicas pudieran deberse a reacciones cruzadas. Se realizaron estudios serológicos para Chagas a 105 muestras provenientes de zona endémica (Corrientes) y no endémica (Buenos Aires) para T. cruzi que presentaban imágenes atípicas con C. luciliae. La serología para Chagas resultó positiva en el 64.7% de las muestras de Buenos Aires y en el 78.3% de las de Corrientes que presentaban frente a C. luciliae imagen conjunta de membrana y flagelo. No presentaron la imagen conjunta ninguna de las muestras de dadores de sangre normales, ni de pacientes con enfermedades del tejido conectivo, excepto dos con lupus que también eran chagásicos. Todas las muestras de pacientes chagásicos analizadas frente a C. luciliae presentaron la imagen conjunta. Se estudiaron también 46 muestras de pacientes con leishmaniasis, 28 de ellos coinfectados con T. cruzi. La imagen conjunta se observó en el 88.0% de las muestras de leishmaniásicos y en el 78.5% de las de coinfectados. Los resultados sugieren que C. luciliae podría ser un sustrato alternativo, económico y de bajo riesgo para el diagnóstico serológico de enfermedad de Chagas, aunque no discrimina la infección por Leishmania. El hallazgo de la imagen conjunta en la detección de anti-ADN nativo señala la conveniencia de realizar en esos pacientes, estudios clínicos y de laboratorio para enfermedad de Chagas y leishmaniasis.

Migration of HIV infected individuals from cities to small towns and rural areas spreads AIDS among non urban population, superimposing HIV with other endemic or epidemic infections as parasitoses. This situation is a big challenge to public health because in most cases the association between these infections worsens both prognoses. We present here the first case in Argentina of AIDS associated to a mucocutaneous form of American tegumentary leishmaniasis. The patient was from Orán, an area where in the middle eighties, an epidemic outbreak took place. By now more than 2000 cases have been parasitologically confirmed in our Institute and the causing species were identified as Leishmania (V.) braziliensis and L. (L.) amasonensis. Considering the existence of co-infection of HIV and Leishmania, it is recommended that in patients from endemic areas with records of cutaneous or mucocutaneous ulcers, even healed, leishmaniasis must be investigated, among other diseases.

Las migraciones a pequeños municipios y áreas rurales de personas infectadas con HIV contribuye a la diseminación progresiva del sida y a la asociación con otras infecciones prevalentes en áreas endémicas, como las parasitosis. Esta asociación significa un importante desafío para la salud pública, ya que frecuentemente ambas infecciones se potencian. En este trabajo presentamos el primer paciente autóctono con sida asociado a leishmaniosis mucocutánea procedente de la zona de Orán, donde a mediados de los 80 se desarrolló un brote epidémico de leishmaniosis que a la fecha supera más de 2000 casos confirmados parasitológicamente en nuestro Instituto. Recientemente informamos la existencia de 2 especies (Leishmania (V.) braziliensis y L. (L.) amasonensis) como las causantes de leishmaniosis tegumentaria americana en la zona. Queremos llamar la atención de los profesionales de la salud sobre la posibilidad de coinfección HIV-Leishmania, recomendando que en pacientes de áreas endémicas con antecedentes de úlceras cutáneas indoloras o incluso cicatrizales, se investigue, entre otras enfermedades, la leishmaniosis.

A clinical-serological follow-up was carried out in a canine population in endemic foci of Leishmania braziliensis spread in northwestern Argentina. Each dog was studied in at least two visits, 309±15 days (X±SE) apart. Some initially healthy dogs (n=52) developed seroconversion or lesions. The clinical evolution of the disease in dogs resembles in many aspects the human disease. Similarities include the long duration of most ulcers with occasional healing or appearance of new ones and the late appearance of erosive snout lesions in some animals. Yearly incidence rates of 22.7% for seroconversion and of 13.5% for disease were calculated as indicators of the force of infection by this parasite upon the canine population.