Hemostatic disorders induced by skin contact with Lonomia obliqua (Lepidoptera, Saturniidae) caterpillars

Patients envenomed by Lonomia sp caterpillars initially experience a mild burning pain, headache, nausea, vomiting, and skin and mucosal hemorrhages. Some patients can rapidly progress to a severe coagulopathy that presents as visceral or intracerebral hemorrhaging. We studied the hemostatic alterations that occurred in 14 patients who were envenomed by Lonomia obliqua in Southern Brazil and presented at the Hospital São Vicente de Paulo (Passo Fundo, RS), Brazil during the summers of 1993 and 1994 when Lonomia antivenom was not yet available for treatment. The patients were classified into to 4 clinical groups: 0 (two patients), I (eight patients), II (two patients), and III (two patients). The patients were admitted to the hospital between 4 hours and five days after contact with the caterpillars. In this study, the coagulation parameters of the patients were followed up for up to 172 hours after the accidents. The patients received no treatment with the exceptions of two patients who received blood transfusions and antifibrinolytic treatment. The observed abnormalities related to blood coagulation and fibrinolytic factors were similar regardless of the severity of the bleeding symptoms. These findings suggest that alterations in hemostatic parameters without thrombocytopenia are not predictors of the seriousness of such accidents. Thus, consumptive disorder and reactive fibrinolysis are not proportional to mild coagulopathy. Furthermore, these patients recovered. The hemostatic parameters of most of the patients normalized between 96 and 120 h after the accident

Isolation and partial characterization of a Protease with kallikrein-like activity from the egg-nests of Hylesia metabus (crammer 1775) (lepidoptera: saturnidae), preliminary communication

Hylesia metabus es una mariposa nocturna distribuida principalmente en el nor-oeste de Venezuela. Las hembras adultas usan sus vellos abdominales para cubrir y proteger los huevecillos de parásitos y depredadores. Estos vellos tienen propiedades urticantes, causando una dermatitis severa entre la población humana, cuyos síntomas se acentúan al usar jabón y se mejoran al aplicar soluciones de un pH ligeramente bajo tal como el vinagre. Sin embargo los vellos de los machos adultos no causan síntoma alguno. En el presente estudio se aisló y caracterizó en forma parcial una proteasa con propiedades parecidas a la calicreina de los vellos presentes en el abdomen de las hembras adultas. El material proteico de las posturas, constituidas por los vellos abdominales de la hembra, fue extraído en tampón Tris-Salino pH 8.5. El extracto fue centrifugado y luego cromatografiado en una columna de exclusión molecular (Sephadex G-75). La actividad biológica de los picos obtenidos fue determinada midiendo la actividad amidolítica con el sustrato cromogénico S-2288 (diseñado para serinaproteasas de amplio espectro) y S-2302 (diseñado para calicreina). Las fracciones con actividad en sustrato S-2302 fueron concentradas mediante ultrafiltración y usadas para otros experimentos. La medición de especificidad a substratos cromogénicos mostró una preferencia para el substrato S-2302 seguido por S-2288. La actividad enzimática tuvo su máximo a pH 9, mientras que por debajo de pH 5 no hubo actividad. Los resultados del presente estudio apoyan la idea de que esta sustancia puede tener importancia en las lesiones cutáneas observadas en personas expuestas a las posturas o las hembras adultas.97 - 102BimestralHylesia metabus is a species of moth, distributed principally in North Eastern Venezuela. Adult females use their abdominal hairs to cover and protect the eggs from predators and parasites. These hairs have urticating properties, causing a severe dermatitis in humans, whose symptoms worsen using soap and are alleviated by slightly acid substances e.g. vinegar. The hairs from male moths however do not produce any symptoms. In the present study we have isolated and partially characterized a protease with kallikrein-like activity from the female abdominal hairs of this species. Egg-nests (consisting mainly of female abdominal hairs) were collected from the twigs of mangrove-trees in affected areas after hatching. The proteic substances were extracted into Tris-buffered saline solution at pH 8.5, centrifuged, and chromatographed by size-exclusion chromatography (Sephadex G-75). Biological activity in the peaks was determined by amidolytic activity in the chromogenic substrates S-2288 (Broad Spectrum Serine Protease Substrate) and S-2302 (Kallikrein substrate). The eluates showing biological activity were concentrated by ultrafiltration and used for further analyses. The specificity in chromogenic substrates showed a preference for the kallikrein substrate S-2302 followed by the broad-spectrum serine protease substrate S-2288. In addition the enzyme showed a pH optimum at pH 9, with no activity below pH 5. Thus the results of the present study support the hypothesis that this substance may be of importance in the lesions observed in individuals exposed to adult females or the egg-nests