Early and late neuropathological features of meningoencephalitis associated with Maraba virus infection

Maraba virus is a member of the genus Vesiculovirus of the Rhabdoviridae family that was isolated in 1983 from sandflies captured in the municipality of Maraba, state of Pará, Amazônia, Brazil. Despite 30 years having passed since its isolation, little is known about the neuropathology induced by the Maraba virus. Accordingly, in this study the histopathological features, inflammatory glial changes, cytokine concentrations, and nitric oxide activity in the encephalon of adult mice subjected to Maraba virus nostril infection were evaluated. The results showed that 6 days after intranasal inoculation, severe neuropathological-associated disease signs appeared, including edema, necrosis and pyknosis of neurons, generalized congestion of encephalic vessels, and intra- and perivascular meningeal lymphocytic infiltrates in several brain regions. Immunolabeling of viral antigens was observed in almost all central nervous system (CNS) areas and this was associated with intense microglial activation and astrogliosis. Compared to control animals, infected mice showed significant increases in interleukin (IL)-6, tumor necrosis factor (TNF)-α, interferon (INF)-γ, MCP-1, nitric oxide, and encephalic cytokine levels. We suggest that an exacerbated inflammatory response in several regions of the CNS of adult BALB/c mice might be responsible for their deaths.

Small-scale environmental enrichment and exercise enhance learning and spatial memory of Carassius auratus, and increase cell proliferation in the telencephalon: an exploratory study

Carassius auratus is a teleost fish that has been largely used in behavioral studies. However, little is known about potential environmental influences on its performance of learning and memory tasks. Here, we investigated this question in C. auratus, and searched for potential correlation between exercise and visuospatial enrichment with the total number of telencephalic glia and neurons. To that end, males and females were housed for 183 days in either an enriched (EE) or impoverished environment (IE) aquarium. EE contained toys, natural plants, and a 12-hour/day water stream for voluntary exercise, whereas the IE had none of the above. A third plus-maze aquarium was used for spatial and object recognition tests. Different visual clues in 2 of its 4 arms were used to guide fish to reach the criteria to complete the task. The test consisted of 30 sessions and was concluded when each animal performed three consecutive correct choices or seven alternated, each ten trials. Learning rates revealed significant differences between EE and IE fish. The optical fractionator was used to estimate the total number of telencephalic cells that were stained with cresyl violet. On average, the total number of cells in the subjects from EE was higher than those from subjects maintained in IE (P=0.0202). We suggest that environmental enrichment significantly influenced goldfish spatial learning and memory abilities, and this may be associated with an increase in the total number of telencephalic cells.

Microglia and neurons in the hippocampus of migratory sandpipers

The semipalmated sandpiper Calidris pusilla and the spotted sandpiper Actitis macularia are long- and short-distance migrants, respectively. C. pusilla breeds in the sub-arctic and mid-arctic tundra of Canada and Alaska and winters on the north and east coasts of South America. A. macularia breeds in a broad distribution across most of North America from the treeline to the southern United States. It winters in the southern United States, and Central and South America. The autumn migration route of C. pusilla includes a non-stop flight over the Atlantic Ocean, whereas autumn route of A. macularia is largely over land. Because of this difference in their migratory paths and the visuo-spatial recognition tasks involved, we hypothesized that hippocampal volume and neuronal and glial numbers would differ between these two species. A. macularia did not differ from C. pusilla in the total number of hippocampal neurons, but the species had a larger hippocampal formation and more hippocampal microglia. It remains to be investigated whether these differences indicate interspecies differences or neural specializations associated with different strategies of orientation and navigation.

Desenvolvimento de método analítico de cromatografia líquida de alta eficiencia (CLAE) para quantificação de lupeol em nanocápsulas poliméricas / Development of analytical method for measurement of lupeol in polymeric nanocapsules by high-performance liquid chromatography (HPLC)

A simple, precise and accurate high-performance liquid chromatographic method has been developed for the determination of lupeol in polymeric nanocapsules. Chromatographic separation was performed on a Varian C8 column (250 mm x 4.6 mm x 5 mm) maintained at 35°C, with a mobile phase composed of acetonitrile and methanol (95:5 v/v) acidified with 0.1% acetic acid, flowing at 1.2 mL/min, with an injected sample volume of 20 µL, UV detection at 210 nm and a run time of 6.2 min. The proposed method was linear over the concentration range 10-250 µg/mL, with R2= 0.9996. Analyses of accuracy and precision showedlow values of relative standard deviation (<4.2%). The methodology was specific, linear, accurate, precise and robust and proved to be adequate for the quantitative analysis of lupeol in polymeric nanocapsules...

Um método de cromatografia líquida de alta performance simples, exato e preciso foi desenvolvido para a determinação do lupeol em nanocápsulas poliméricas. A separação cromatográfica foi realizada numa coluna Varian C8 (250 mm x 4,6 mm x 5 mm), mantida a 35°C, fase móvel constituída por acetonitrila e metanol acidificado com ácido acético a 0,1% (95:5 v/v), e taxa de fluxo de 1,2 mL/min, com um volume injeção de amostra de 20 µl e detecção UV a 210 nm, com o tempo de eluição de 6,2 min. O método proposto é linear para a faixa de concentração de 10 a 250 µg/mL com coeficiente de correlação de 0,9996. As análises de exatidão e precisão demonstraram baixos valores de desvio padrão relativo (< 4,2%). A metodologia foi específica, linear, precisa, exata e robusta, se mostrando capaz de ser aplicada para quantificação de lupeol em nanocápsulas poliméricas...