RÉSUMÉ
The survival and molting incidence in Triatoma infestans, a vector of Chagas disease, were investigated following sequential shocks at 0 degrees C in fifth instar nymphs under moderate fasting and full nutritional conditions. The shocks were separated by intervals of 8 h and 24 h at 30 degrees C. The results indicated that in terms of insect survival, T. infestans is tolerant to a single cold shock at 0 degrees C even for 12 h, or to sequential cold shocks, regardless of the nutritional state of the specimens. In terms of molting rate, fasting enhanced the tolerance to sequential cold shocks, but did not exceed the tolerance acquired by fully-nourished specimens, except when cold shocks were separated by an 8 h interval at 30 degreesC. The protective action elicited by fasting was assumed to be additive to that induced by a single mild cold shock or sequential cold shocks. The cold-tolerance response of T. infestans may have favoured its survival in areas of South America with low temperatures, even considering that this species is predominantly associated with human habitats.
Sujet(s)
Basse température , Mue/physiologie , Triatoma/physiologie , Animaux , Nymphe/physiologieRÉSUMÉ
The survival and molting incidence in Triatoma infestans, a vector of Chagas disease, were investigated following sequential shocks at 0ºC in fifth instar nymphs under moderate fasting and full nutritional conditions. The shocks were separated by intervals of 8 h and 24 h at 30ºC. The results indicated that in terms of insect survival, T. infestans is tolerant to a single cold shock at 0ºC even for 12 h, or to sequential cold shocks, regardless of the nutritional state of the specimens. In terms of molting rate, fasting enhanced the tolerance to sequential cold shocks, but did not exceed the tolerance acquired by fully-nourished specimens, except when cold shocks were separated by an 8 h interval at 30ºC. The protective action elicited by fasting was assumed to be additive to that induced by a single mild cold shock or sequential cold shocks. The cold-tolerance response of T. infestans may have favoured its survival in areas of South America with low temperatures, even considering that this species is predominantly associated with human habitats
Sujet(s)
Animaux , Triatoma , Basse température , Mue , Taux de survie , NympheRÉSUMÉ
Intense acute stress, consequent to restraint, leads to a diminished production of IgE antiovalbumin antibodies in mice. The IgE content of sera from experimental or control animals was assayed by the enzyme-linked immunosorbent assay (ELISA) at days 8, 16, and 20 after immunization. The statistics revealed significant differences in the IgE level of the animals submitted to acute stress and home cage control animals on days 16 and 20 after immunization, but not on day 8.
Sujet(s)
Éveil/physiologie , Immunoglobuline E/biosynthèse , Stress physiologique/immunologie , Anaphylaxie/immunologie , Animaux , Tolérance immunitaire/immunologie , Mâle , Souris , Souris de lignée A , Ovalbumine/immunologie , Environnement socialRÉSUMÉ
Os autores relatam um caso de leiomiossarcoma gastrico diagnosticado inicialmente como neoplasia hepatica. Discutem o aspecto ultra-sonografico correlacionando com a radiologia convencional