Zinc sulfide in intestinal cell granules of Ancylostoma caninum adults.

A source of confusion has existed since the turn of the century about the reddish brown, weakly birefringent "sphaerocrystals" located in the intestines of strongyle nematodes, Strongylus and Ancylostoma. X-ray diffraction and energy dispersive spectrometric analyses were used for accurate determination of the crystalline order and elemental composition of the granules in the canine hookworm Ancylostoma caninum. The composition of the intestinal pigmented granules was identified unequivocally as zinc sulfide. It seems most probable that the granules serve to detoxify high levels of metallic ions (specifically zinc) present due to the large intake of host blood.

Transmisión de parásitos intestinales en grupos nativos de la amazonía: un estudio microepidemiológico / Intestinal diseases parasitic communicable at Amazon natives. A microepidemiology study

Se estudió una comunidad nativa de 60 habitantes que viven relativamente aislados en la selva Amazónica. Se hicieron análisis cuantitativos de heces (excreción de huevos de parásitos por persona), y se determinó la contaminación del medio ambiente por huevos de parásitos intestinales (Ascaris lumbricoides, Trichuris trichiura y Ancylostoma duodenale). El número promedio de huevos en las heces fue de 4220 huevos de Ascaris lumbricoides por cada gramo de heces. No se encontraron diferencias significativas en la intensidad de infección según edad, sexo o familia. El riesgo de infección parasitaria fue aproximadamente igual en toda la comunidad: cualquier persona del poblado corre el mismo riesgo de infección por el estilo comunitario de vida en grupo y sobre todo por la transmisión de los huevos por vía aérea en el polvo. Sin embargo, se encontró diferentes intensidades de contaminación, en las casas y en sus alrededores (promedio: 0-17 huevos de Asvaris lumbricoides por gramo de tierra). Se hizo un tratamiento masivo de toda la población con Mebendazol. Cinco meses después la población había logrado los niveles de prevalencia acusados antes del tratamiento, sólo la intensidad de infección había disminuido significativamente. Se concluye que la planificación de medidas higiénicas debe considerar toda la comunidad en conjunto.

Ancylostoma ceylanicum: I. Protein and antigenic composition of adult and larval stages.

The protein and antigenic composition of adult and larval stages of Ancylostoma ceylanicum, a human hookworm maintained in golden hamsters (Mesocricetus auratus), was studied employing immunochemical techniques. SDS-polyacrylamide gel electrophoresis revealed the presence of 47 and 43 protein bands in adult worms and infective larvae respectively in the molecular weight range of 10-170 kD. Crossed immunoelectrophoretic analysis, using immune rabbit sera, showed the presence of 32 antigenic peaks in adults and 19 in infective larval stage. Most of the antigens were common between adult and larval stage as evidenced by cross-line immunoelectrophoresis, although some stage specific antigens were also identified. These studies also demonstrate the complex nature of adult worms as compared to larvae.

The anticoagulant effects of the hookworm, ancylostoma ceylanicum: observations on human and dog blood in vitro and infected dogs in vivo.

Extracts of adult Ancylostoma ceylanicum prolonged the prothrombin time (PT) and partial thromboplastin time with kaolin ( PPTK ) of both human and dog plasmas in vitro. Excretory/secretory (E/S) products of these worms had similar effects while larval extract prolonged the PTTK only. Thus, the anticoagulant activities of this parasite are dependent upon the stage of the worm's life cycle. Collagen- and ADP-induced platelet aggregation were inhibited by adult and larval extracts. When the peripheral blood and bleeding times of dogs with varying worm burdens were examined, the only abnormality was shortening of the PTTK in the most heavily infected animals. Homogenates of dog small bowel subjacent to adult hookworms prolonged the PT of dog plasma and electron microscopical examination of this tissue revealed aggregation of platelets in blood venules without fibrin deposition. Thus, this study provides evidence that the anticoagulant properties of hookworms may have biological significance in infected animals.

Investigations into the free-living phase of the cat hookworm life cycle.

Laboratory studies were undertaken to evaluate the role of environmental factors on the development of free-living stages of the cat hookworm Ancylostoma tubaeforme. An index of development calculated from the proportion of eggs that developed to the infective stage and the reciprocal of the development period, has suggested that the absence of 'high' temperatures (26 degrees - 30 degrees C) would significantly affect the L3 population in contaminated soils. There were, however, no significant differences in the size and lipid content of L3 that had developed at the different temperatures.

On the phospholipids of adult Ancylostoma caninum.

The phospholipid composition of Ancylostoma caninum has been examined. Phospholipids amounted to 0.9% of the wet weight of the parasite. Ethanolamine and choline containing lipids comprised about 76% of the total phospholipids. Lysolecithin, sphingomyelin, phosphatidyl inositol and phosphatidyl serine were present in minor amounts. Cerebrosides and sulfatides were also identified.