Histopathological and Immunohistochemical Studies of Pineoblastoma in a Cow.

We report the first case of pineoblastoma in a cow. At necropsy, a soft, gelatinous greyish yellow, 4 × 3 × 2 cm mass was found midsagittally on the dorsal surface of the midbrain. The mass enveloped the brainstem anterior to the cerebellum, extended to the pituitary fossa and was adherent to the ventromedial aspect of the occipital lobes. Histologically, the mass was unencapsulated, with extramedullary proliferation into the lobes and meninges, but was demarcated from the adjacent brain tissue. Histological findings were consistent with a pineoblastoma, as reported in other species, and the neoplasm was strongly immunopositive for synaptophysin. Glial fibrillary acidic protein-positive spindloid astrocytic processes surrounded blood vessels and extended around neoplastic cells.

Gene silencing in Echinococcus multilocularis protoscoleces using RNA interference.

We investigated the potential of gene silencing in Echinococcus multilocularis protoscoleces using RNA interference (RNAi). For the introduction of siRNA, soaking and electroporation were first examined for their effects on the viability of protoscoleces and their efficacy for siRNA introduction. Consequently, electroporation using 100 V and 800 µF showed the optimal results. This electroporation procedure was then evaluated for its ability to induce RNAi in protoscoleces using siRNAs targeting the 14-3-3 and elp genes. It was found that the levels of 14-3-3 and elp mRNA in 14-3-3 siRNA- and elp siRNA-treated protoscoleces were reduced to 21.8 ± 2.6 and 35.5 ± 0.4% of those of the untreated control by day 3, respectively. Moreover, the target proteins significantly decreased in the siRNA-treated samples by day 15. In the analysis of viability, the untreated control, electroporation control, 14-3-3 siRNA-treated, and elp siRNA-treated samples displayed 98.4 ± 1.4, 83.0 ± 2.5, 58.0 ± 23.0, and 55.1 ± 14.6% viability, respectively, on day 15. In conclusion, we successfully demonstrated that RNAi mediated the knock-down of target gene expression in E. multilocularis protoscoleces at both the transcriptional and translational levels.

Echinococcus multilocularis primary cells: improved isolation, small-scale cultivation and RNA interference.

In this study we demonstrate RNA interference mediated knock-down of target gene expression in Echinococcus multilocularis primary cells on both the transcriptional and translational level. In addition, we report on an improved method for generating E. multilocularis primary cell mini-aggregates from in vitro cultivated metacestode vesicles, and on the cultivation of small numbers of small interfering RNA-transfected cells in vitro over an extended period of time. This allows assessments on the effects of RNA interference performed on Echinococcus primary cells with regard to growth, proliferation, differentiation of the parasite and the formation of novel metacestode vesicles in vitro.

Evaluation of efficacy of bruceine A, a natural quassinoid compound extracted from a medicinal plant, Brucea javanica, for canine babesiosis.

Bruceine A, a natural quassinoid compound extracted from the dried fruits of Brucea javanica (L.) Merr., was evaluated for its antibabesial activity in vitro and in vivo. Bruceine A inhibited the in vitro growth of Babesia gibsoni in canine erythrocytes at lower concentration compared with the standard antibabesial drug diminazene aceturate and killed the parasites within 24 hr at a concentration of 25 nM. Oral administration of bruceine A at a dosage of 6.4 mg/kg/day for 5 days resulted in no clinical findings in a dog with normal ranges of hematological and biochemical values in the blood. Three dogs were infected with B. gibsoni and two of them were treated with bruceine A at a dosage of 6.4 mg/kg/day for 6 days from day 5 post-infection. An untreated dog developed typical acute babesiosis symptoms including severe anemia, high fever, and complete loss of appetite and movement. However, the two bruceine A-treated dogs maintained their healthy conditions throughout the experimental period of 4 weeks although complete elimination of parasites from the peripheral blood was not achieved and decreases in the packed cell volume and the erythrocyte and platelet counts were observed. Since natural quassinoid compounds have been used as traditional medicines for the treatment of various ailments including cancer and malaria, the present results suggest that bruceine A or other related compounds are potential candidates for the treatment of canine babesiosis.