RESUMO

A phospholipase A2 has been isolated from Bothrops jararacussu venom from snakes that inhabit the northeast region of Argentina. The present study describes in vivo and in vitro biological activities of phospholipase A2 from B. jararacussu as well as isolation details of its. Venom was obtained by milking of adult snakes which were housing in wood reptile cages of varying dimensions in heated (20-30ºC) rooms. Snakes received a weekly diet of mice and water was available ad libitum for drinking and soaking. The enzyme was purified by gel filtration on a Sephadex G-75 column followed by ion exchange chromatography on a SP-Sephadex C25 column. The major peak belonging to proteins was retained in the cation exchanger and then eluted using a concentration gradient of KCl that exhibited phospholipase activity. This basic PLA2 consists of a single polypeptide chain with a molecular mass of 15.6 kDa. It had a high indirect hemolytic activity and produced a significant paw edema reaction in mice. The enzyme showed a low lethality (LD50 148.6 mg) when was administered i.p. but exhibited elevated myotoxic effects in vivo by increasing plasma CK activity of injected mice, corroborated results by the histological observations of samples of gastrocnemius muscle. Myonecrosis is the result of intense destruction of muscular fibers that involves local infiltration of inflammatory cells and leads to the highest peak of CK level just after 1 hour mice injection. Moreover, the isolated enzyme showed anticoagulant activity, evaluated on sheep platelet-poor plasma which recalcification time was prolonged after incubation with the isolated phospholipase A2. These findings showed that this phospholipase, isolated by only two simple chromatographic steps, possesses high edematogenic and myotoxic activities. However, despite the low lethal activity, this enzyme would contribute markedly to the pathophysiology of the bothropic envenomation.(AU)

RESUMO

A phospholipase A2 has been isolated from Bothrops jararacussu venom from snakes that inhabit the northeast region of Argentina. The present study describes in vivo and in vitro biological activities of phospholipase A2 from B. jararacussu as well as isolation details of its. Venom was obtained by milking of adult snakes which were housing in wood reptile cages of varying dimensions in heated (20-30ºC) rooms. Snakes received a weekly diet of mice and water was available ad libitum for drinking and soaking. The enzyme was purified by gel filtration on a Sephadex G-75 column followed by ion exchange chromatography on a SP-Sephadex C25 column. The major peak belonging to proteins was retained in the cation exchanger and then eluted using a concentration gradient of KCl that exhibited phospholipase activity. This basic PLA2 consists of a single polypeptide chain with a molecular mass of 15.6 kDa. It had a high indirect hemolytic activity and produced a significant paw edema reaction in mice. The enzyme showed a low lethality (LD50 148.6 mg) when was administered i.p. but exhibited elevated myotoxic effects in vivo by increasing plasma CK activity of injected mice, corroborated results by the histological observations of samples of gastrocnemius muscle. Myonecrosis is the result of intense destruction of muscular fibers that involves local infiltration of inflammatory cells and leads to the highest peak of CK level just after 1 hour mice injection. Moreover, the isolated enzyme showed anticoagulant activity, evaluated on sheep platelet-poor plasma which recalcification time was prolonged after incubation with the isolated phospholipase A2. These findings showed that this phospholipase, isolated by only two simple chromatographic steps, possesses high edematogenic and myotoxic activities. However, despite the low lethal activity, this enzyme would contribute markedly to the pathophysiology of the bothropic envenomation.

RESUMO

Desde los años ochenta ha habido un resurgimiento de infecciones severas por Streptococcus b hemolítico Grupo A (SBHGA). Objetivo: Evaluar en nuestro medio el comportamiento clínico y los factores predisponentes en infecciones invasoras por SBHGA. Material y Métodos: Se analizaron antecedentes clínicos de 37 fichas de niños con cultivo positivo al SBHGA hospitalizados en el Servicio de Pediatría y Cirugía Infantil del Hospital Dr. Félix Bulnes Cerda entre marzo de 1995 y enero de 2005. Resultados: 81 por ciento fueron pacientes eutróficos sin patología asociada. Destacan como factores condicionantes: quemadura (30 por ciento), varicela (19 por ciento) y traumatismo (16 por ciento). La sintomatología más frecuente fue fiebre (84 por ciento) y signos inflamatorios locales (40 por ciento). Los cuadros clínicos fueron: infección de tejido blando (32 por ciento), bacteremia sin focalización (30 por ciento), osteoartritis (10,8 por ciento), pleuroneumonía (10,8 por ciento), shock tóxico (8,1 por ciento) y fasceitis necrotizante (5,4 por ciento). Tres pacientes fallecieron. Conclusión: Las infecciones invasoras por SBHGA afectan mayoritariamente a niños sanos cuyo principal factor predisponente es una puerta cutánea, y puede ser fatal.

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La obstrucción del flujo biliar al tubo digestivo es siempre un problema muy grave; de no solucionarse termina con la vida del paciente y a veces en forma lenta y tormentosa. Cuando esto sucede una forma de reconstrucción de este flujo, de acuerdo a la anatomía resultante es la hepaticoyeyunostomía. En este trabajo se presenta la experiencia y resultados inmediatos en esta técnica en el Servicio de Cirugía entre octubre de 1993 y junio de 1997. La serie está formada por 13 pacientes, 5 hombres y 8 mujeres. La edad promedio fue 40 años. La razón de la obstrucción biliar fue iatrogenia en 11 y patología benigna en 2. La hepaticoyeyunostomía sólo en 2 casos se realizó en la misma operación, motivo del accidente, y el los otros 4 en cirugía abierta. En 2 casos de colecistectomía laparoscópica no se notificaron incidentes en el momento de ella apareciendo la complicación en meses posteriores. En la serie no hubo fallecidos pero sí complicaciones en 8 de los 13 pacientes (61 por ciento); 3 fueron reoperados. Se concluye que los resultados son satisfactorios pues no hubo mortalidad aunque la morbilidad fue elevada. La evaluación definitiva de éstos sólo se puede efectuar a largo plazo

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Identification and characterization of immunodominant antigens in hydatid fluid was performed by electrophoresis in polyacrylamide gels (SDS PAGE) followed by immunoelectrotransfer (Western Blot). The studies were performed in sera of 23 patients with surgically confirmed hydatid disease, 12 patients with clinical suspicion of the infection and positive serology according to conventional serology (double diffusion with detection of are 5 and ELISA test), 28 healthy subject and 23 patients with parasitic infections different from hydatidosis. The results showed 7 antigenic bands located between 8 and 120 kDa, two immunodominant bands (MW 8 and 12 kDa) were recognized by the sera of patients suffering from hydatid disease and those with positive serology. Two additional bands were detected by the sera of healthy subjects and by the samples of patients presenting cysticercosis. It is concluded that the antigens with molecular weights of 8 and 12 kDa. would be those of major diagnostic value, while those of 32 and 60 kDa are nonspecific.

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BACKGROUND: The prevalence of positive antibodies for Chagas disease in a blood bank of a public hospital in Santiago is 1.2%. These positive individuals should be informed about their condition and further studied. AIM: To perform a serological confirmation, an epidemiological and clinical assessment of blood donors seropositive for Chagas disease in a blood bank of Santiago. SUBJECTS AND METHODS: One hundred eleven seropositive donors, detected between 1994 and 1996, were studied. Serological reactions were confirmed with ELISA and indirect immunofluorescence reactions. Those confirmed as positive were subjected to a clinical-epidemiological questionnaire, physical examination, EKG and barium enema or swallow according to symptoms. RESULTS: Seventy individuals were confirmed as positive for Chagas disease. Most of them lived at least once in an endemic zone for Chagas disease or in a sun-dried clay brick house. Forty-percent of individuals knew reduviid bugs and 14% had been bitten by these insects. Twenty six percent of these subjects had an abnormal EKG (61% with bradycardia). No digestive diseases attributable to Chagas disease were detected. CONCLUSIONS: The high prevalence of problems attributable to Chagas disease among seropositive blood donors underscores the need of an epidemiological follow up of these individuals.

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P carinii is an opportunistic pathogenic agent able to produce severe infection that must be diagnosed promptly. We analyzed 138 samples from 100 patients suspected of having infection by P carinii. The ortho-toluidine blue and the methenamine stains were used to analyze the samples. Infection was demonstrated in 18 patients, 13 adults and 5 children. Underlying disease was AIDS in 7 and other immunosuppressive disorders in the rest. No immunocompetent patient was infected with P carinii. Proper sample collection is important for diagnosis. When bronchoalveolar lavage is not possible, pharyngo-tracheal aspirate in children and sputum sampling after assisted coughing in adults are recommended. At least 2 staining methods and proper controls are advisable.

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