Estudio descriptivo de la bibliografía consultada bajo la modalidad de aprendizaje basado en problemas. Análisis de caso / Descriptive study of the literature consulted under the modality of problem-based learning. Case analysis

La búsqueda de información es un tema fundamental en la metodología Aprendizaje Basado en Problemas (ABP), sin embargo, la bibliografía que lo aborda es escasa. El propósito de este trabajo fue describir las diferentes fuentes bibliográficas a las que acceden los estudiantes de la carrera de Medicina de la Universidad Nacional del Sur, Argentina, bajo la modalidad de ABP y analizar si existe algún patrón de búsqueda. Estudio analítico transversal descriptivo. Para clasificar los diferentes tipos de fuentes bibliográficas se definieron las siguientes categorías: libros ciencias básicas; libros área clínica; artículos de investigación; guías de práctica clínica; artículos de revisión; Web oficial; Web no oficial; UptoDate; apuntes de cátedra y otros. El análisis de las búsquedas realizadas por los estudiantes bajo la modalidad ABP demostró que los libros de ciencia básica se utilizaron en mayor medida al comienzo de las unidades de aprendizaje, mientras que los artículos de revisión y guías de práctica clínica se emplearon de manera uniforme a lo largo de toda la unidad. Los estudiantes demostraron habilidades en la búsqueda bibliográfica, utilizando fuentes científicas y sitios web de rigurosa calidad.

The search for information is a fundamental issue in the Problem-Based Learning (PBL) methodology, however, the bibliography that addresses it is scarce. The purpose of this paper was to describe the different bibliographic sources accessed by students of the Medical School of the Universidad Nacional del Sur, Argentina, under the ABP modality and to analyze if there is any search pattern. Descriptive crosssectional analytical study. In order to classify the different types of bibliographic sources, the following categories were defined: basic science books, clinical area books, research articles, clinical practice guidelines, review articles, official website, unofficial website, UptoDate, lecture notes and others. Analysis of the student searches conducted under the ABP mode showed that basic science books were used most at the beginning of the learning units, while review articles and clinical practice guidelines were used consistently throughout the unit. Students demonstrated skills in literature searching, using scientific sources and rigorous quality websites.

Ecoepidemiología de las lesiones causadas por medusas urticantes en el balneario de Monte Hermoso. Buenos Aires. Argentina / Ecoepidemiology of lesions caused by venomous jellyfish in Monte Hermoso beach. Buenos Aires. Argentina

En la costa sudoeste bonaerense uno de los principales desafíos para el turismo es el tratamiento y la prevención de envenenamientos por medusas. Hasta el momento se conocen tres especies de medusas urticantes que arriban a la costa: Chrysaora lactea, Liriope tetraphylla y Olindias sambaquiensis. Los objetivos de este trabajo fueron: calcular los parámetros poblacionales de las medusas urticantes, efectuar el diagnóstico diferencial de los síntomas causados por envenenamiento, analizar el número de afectados en relación a la abundancia de medusas urticantes, evaluar la elección diferencial del centro de atención primaria elegido por los afectados y confeccionar un algoritmo diagnóstico. El número de medusas urticantes en el año 2016 fue cinco veces mayor que en 2017. Liriope tetraphylla registró las mayores abundancias promedio, frecuencias y dominancias relativas. En 2016 coincidió su mayor abundancia con el mayor porcentaje de afectados. En 2016 se registraron 69 casos totales de envenenamiento y en 2017 se identificaron 79 casos. En 2017 el porcentaje de personas afectadas por O. sambaquiensis no presentó una correlación con la abundancia promedio de esta especie. Liriope tetraphylla causó lesiones eritematomaculo-papulares acompañadas de prurito sin dolor, C. lactea provocó lesiones eritemato-vesiculosas de dolor moderado y O. sambaquiensis lesiones eritemato-edematosas lineales de dolor intenso con hiperpigmentación residual. No existe tratamiento específico para el envenenamiento, la terapéutica diferencial es sintomática. Las primeras acciones son comunes para las tres especies: lavar con solución fisiológica o agua de mar limpia y aplicar compresas frías.

On the Southwest coast of Buenos Aires Province one of the main challenges for tourism is the treatment and prevention of poisoning by jellyfish. So far, three species of venomous jellyfish arriving to the coast have been identified: Chrysaora lactea, Liriope tetraphylla, and Olindias sambaquiensis. The objectives of this study were: to calculate the population parameters of the venomous jellyfish, to carry out a differential diagnosis of the symptoms caused by poisoning, to analyze the number of individuals affected in relation to the abundance of this jellyfish, to evaluate which primary care centers are chosen by those affected, and to develop a diagnostic algorithm. The number of venomous jellyfish in 2016 was five times higher than in 2017. The highest average abundance, frequency, and relative dominance were recorded for L. tetraphylla. In 2016, its greatest abundance coincided with the highest percentage of people affected by this species. A total of 69 confirmed cases of poisoning caused by the three species were recorded in 2016 and 79 cases in 2017. In 2017, the percentage of people affected by O. sambaquiensis was not correlated with the average abundance of this species. Liriope tetraphylla caused erythematous-maculopapular lesions accompanied by painless pruritus; C. lactea caused erythematous-vesicular lesions of moderate pain and O. sambaquiensis caused linear erythematous-edematous lesions with severe pain and residual hyperpigmentation. At present, there is no specific treatment for poisoning, the differential therapy is symptomatic. The recommended actions are common for all three species: wash the skin with physiological solution or clean sea water and apply cold compresses.

Seasonal variation of parasitism in pejerrey Odontesthes bonariensis (Atheriniformes, Atherinopsidae) from La Viña reservoir (Córdoba, Argentina) / Variação sazonal do parasitismo em Peixe-rei Odontesthes bonariensis (Atheriniformes, Atherinopsidae) no reservatório La Viña, Córdoba, Argentina

The pejerrey Odontesthes bonariensis is the most important freshwater fish of Argentina central region. The present study was conducted to describe the seasonal variation of parasitism in O. bonariensis from La Viña reservoir (31º 17'S, 65º 01'W), located in the province of Córdoba, Argentina. Between years 1999 and 2002, 573 fishes were caught, and their parasite infection and relative weight (Wr) were assesed. Three parasites were found, Lernaea cyprinacea (Crustacea), Contracaecum spp. larvae (Nematoda) and Cangatiella macdonaghi (Cestoda). Overall, Contracaecum spp. prevalence and intensity were very low. Lernaea cyprinacea and Cangatiella macdonaghi prevalences increased during summer and spring (P < 0.01), respectively. Lernaea cyprinacea infection showed also seasonal differences in intensity (P < 0.05), as well as C. macdonaghi regarding parasites density (P < 0.01). Cangatiella macdonaghi average parasites density was 32.0 (±22.5) cestodes per cm³ of digestive content. No association between parasitism and fish relative weight was found. Besides the seasonality variations observed, the parasite burden found did not compromise fish body condition.

O peixe rei Odontesthes bonariensis é um peixe de água doce de grande importância na região central da Argentina. O objetivo deste trabalho foi descrever a sazonalidade do parasitismo de O. bonariensis no reservatrio La Viña (31º 17'S, 65º 01'W), província de Córdoba, Argentina. Durante os anos 1999 e 2002 foram capturados 573 peixes. Nestes se fez à avaliação da condição corporal usando como parâmetro o peso relativo e identificaram-se os seguintes parasitos: Lernaea cyprinacea (Crustacea), Contracaecum spp. (Nematoda) e Cangatiella macdonaghi (Cestoda). As prevalências e intensidades de Contracaecum spp. foram muito baixas. Houve diferenças nas prevalências de L. cyprinacea e C. macdonaghi na época do ano (P < 0,01), sendo maiores no verão e na primavera, respectivamente. Houve diferenças estacionais na intensidade de L. cyprinacea (P < 0,05) e na densidade de C. macdonaghi (P < 0,01), neste ultimo alcançou-se um valor máximo nas amostras de 32,0 (±22,5) parasitos por cm³ de conteúdo digestivo. Não houve associação entre o parasitismo e o peso relativo dos peixes. Embora haja certa sazonalidade, as diferentes cargas parasitárias encontradas nâo prejudicam a saúde de O. bonariensis enquanto sua condição corporal.

Nematodes anisákidos presentes en peces del área de Bahía Blanca y el riesgo potencial de anisakidosis humana / Anisákidos nematodes present in fish from the Bahía Blanca area and the potential risk of human anisakidosis

Objetivos: En el presente tra bajo, se dan a conocer las especies de nematodes anisákidos que parasitan peces destinados al consumo humano y valores de prevalencia e intensidad de infección, evaluando el riesgo potencial que representa el consumo de carne sin la debida cocción de estas especies. Resultados: Se examinaron 1250 ejemplares de peces marinos del estuario de Bahía Blanca, pertenecientes a 22 especies, consideradas habituales en el área. En los peces examinados se identificaron nematodes anisákidos al estadio de larva 3 (L3), pertenecientes a cinco géneros: Anisakis, Pseudoterranova, Contracaecum, Hysterothylacium y Terranova. Catorce especies de peces resultaron parasitadas por al menos una especie de anisákido, en tanto sólo la pescadilla y la palometa albergaron larvas de Anisakis sp. Sin embargo, la intensidad media de infección y la abundancia en la pescadilla tienen valores muy bajos, no habiéndose registrado su presencia más que en la cavidad visceral. En el caso de la palometa, la intensidad absoluta de infección suele ser mayor, pero la prevalencia es menor que en la pescadilla. Además, tampoco se han reportado casos de invasión muscular en el filet de palometa. En el resto de los peces examinados los estimadores poblacionales son muy fluctuantes, pero un común denominador es la baja intensidad media en todos ellos, no llegando a superar los 2-3 individuos por hospedador. Conclusiones: El 63% de las especies examinadas en el estuario de Bahía Blanca y áreas adyacentes albergan larvas de anisákidos. La forma dominante es Contracaecum, que cierra su ciclo de transmisión en lobos marinos, seguida por Terranova, que completa su madurez sexual en tiburones. Los peces cartilaginosos presentaron larvas en el lumen intestinal, procedentes de presas digeridas, no observándose invasión por anisákidos a la cavidad corporal. No se comprobó infección a la musculatura estriada esquelética de los peces, por Anisakis ni Pseudoterranova.

ABSTRACT Objectives: In this work, anisakid nematode species parasiting on fish for human consumption and values of prevalence and intensity of infection are reported, thus assessing the potential risk represented by consumption of the improperly cooked fish meat of these species. Results: 1250 specimens of marine fish from Bahía Blanca estuary, belonging to 22 common species in this area, were examined. In the fish under study, anisakid nematodes at larva stage 3 (L3) belonging to five genera were identified: Anisakis, Pseudoterranova, Contracaecum, Hysterothylacium, and Terranova. Fourteen fish species were parasitized by at least one anisakid species. However, only the striped weakfish and the Argentine queen fish harbored Anisakis sp. larvae and mean infection intensity as well as striped weakfish abundance show very low values. Infection was only detected in the visceral cavity. In the case of the Argentine queen fish, the absolute infection intensity is generally higher, although prevalence is lower than in striped weakfish. In addition, no muscular invasion cases were reported in striped weakfish filet. In the rest of the fish examined, population estimators are quite variable. However, a common feature is the low mean intensity in all of them, less than 2-3 individuals by host. Conclusions: 63% of fish species examined in Bahía Blanca estuary and nearby areas harbor anisakid larvae. Contracaecum larvae were the dominant anisakids found in the fish, which complete their transmission cycle in seals, followed by Terranova, which complete their sexual maturity in sharks. Cartilaginous fish presented larvae located in the intestinal lumen from the prey digested. However, no invasion of anisakids was observed in the body cavity and no infection by Anisakis or Pseudoterranova was found in the striated somatic muscles of fish.