ABSTRACT
Lutzomyia longipalpis s.l. is the primary vector of Leishmania (L.) infantum in the New World. In this study, male Lutzomyia longipalpis specimens from Posadas, Argentina were characterized for two polymorphic markers: the male sex pheromone and the period (per) gene. The male sex pheromone was identified as (S)-9-methylgermacrene-B, the same compound produced by Lu. longipalpis from Paraguay and many populations from Brazil. The analysis of per gene sequences revealed that the population from Argentina is significantly differentiated from previously studied Brazilian populations. Marker studies could contribute to the understanding of the distribution and spread of urban American visceral leishmaniasis, thus aiding in the design of regional surveillance and control strategies.
Subject(s)
Animals , Male , Insect Vectors , Psychodidae , Sesquiterpenes, Germacrane , Sex Attractants , ArgentinaABSTRACT
The sandfly Lutzomyia longipalpis (Lutz & Neiva) vectors leishmaniasis in the neotropics. Although much is known about the biology of adult flies, little is known about interactions with its natural enemies. Here, we examined behavior of larvae of L4 L.longipalpis on a soil substrate when exposed to the fire ant Solenopsis invicata (Westwood). When ants were absent, most larvae tended to remain at or close to the soil surface, but when ants were present the larvae burrowed into the soil. Sandflies seek refuges in the presence of generalist predators, thus rendering them immune to attack from many potential enemies.
Subject(s)
Animals , Ants , Consummatory Behavior , Psychodidae/physiologyABSTRACT
A group of 18 research workers involved in different aspects of the biology of Lutzomyia longipalpis discussed whether or not it is important to give taxonomically valid names to populations that have been defined by biological, biochemical and molecular methods to be reproductively isolated. The type material of this medically important species has been lost and because of this it was recommended that a colony should be established from insects captured in the region of the type area and that their description should serve as the basis for future descriptions. It was pointed out that there is a lack of uniformity in the naming of closely related American sand flies and that some of the differences between populations of Lu. longipalpis are greater than those between accepted species. The majority of the participants agreed that the populations that have been defined in the literature as sibling species should be named.
Subject(s)
Animals , Insect Vectors/classification , Psychodidae/classification , ClassificationABSTRACT
Los tumores del estroma gastrointestinal (GIST) son neoplasias de baja frecuencia que presentan menos del 1 por ciento de todos los tumores del tracto digestivo. Inicialmente se clasificaban dentro del grupo de los sarcomas pero actualmente se consideran como una entidad clínico patológica diferente. Comprometen con mayor frecuencia el estómago pero se pueden presentar en cualquier otra ubicación del tracto digestivo donde exista músculo liso. Su diagnóstico es histológico. El 80 por ciento de estos tumores expresa CD 117 y el 20 por ciento restante tiene mutaciones en un receptor de Tirosina-Kinasa (TK) relacionado con PDGFRa (platelet-derived growth factor receptor alpha). El tratamiento se basa en cirugía y administración de inhibidores de Tirosina-Kinasa. En este trabajo se presentan tres casos clínicos de GIST del aparato digestivo. CD 117 positivos. Se revisan los aspectos fisiopatológicos, clínicos, diagnóstico y terapéuticos de este tipo especial de tumores.