Publications by authors named "Z Woldehiwet"

Anaplasma phagocytophilum, the causative agent of tick-borne fever (TBF) in sheep and cattle and human granulocytic anaplasmosis, has the unique ability to selectively infect and multiply within the hostile environment of the neutrophil. Previous studies have shown that sheep with TBF are more susceptible to other infections and that infected neutrophils have reduced phagocytic ability and delayed apoptosis. This suggests that survival of A.

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This study aimed at assessing the effects of diazoxon (DZO), a major metabolite of the insecticide diazinon (DZ), on key cytoskeletal proteins in differentiating N2a neuroblastoma cells. Initial experiments established that sublethal concentrations of 1, 5 and 10 μM DZO produced profound inhibition of neurite outgrowth. Densitometric scanning of probed immunoblots of N2a cell lysates demonstrated that DZO had no effect on total β-tubulin levels.

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Background: Global environmental change is causing spatial and temporal shifts in the distribution of species and the associated diseases of humans, domesticated animals and wildlife. In the on-going debate on the influence of climate change on vectors and vector-borne diseases, there is a lack of a comprehensive interdisciplinary multi-factorial approach utilizing high quality spatial and temporal data.

Methods: We explored biotic and abiotic factors associated with the latitudinal and altitudinal shifts in the distribution of Ixodes ricinus observed during the last three decades in Norway using antibodies against Anaplasma phagocytophilum in sheep as indicators for tick presence.

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Sheep infected with Anaplasma phagocytophilum, the causative agent of tick-borne fever (TBF), develop humoral immune responses 7-14 days after infection. Those individuals that survive acute TBF develop persistent infection, which may last for several months or even for life. The persistence of infection and recurrent bacteraemia is thought to be due to p44-mediated antigenic variation.

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Following experimental or natural infection with Anaplasma phagocytophilum, the causative agent of tick-borne fever (TBF), sheep may be infected persistently for several months or years. In the present study, quantitative real-time polymerase chain reaction was used to investigate the duration and magnitude of primary bacteraemia and to establish whether the organism is present continuously in the peripheral blood after the period of primary bacteraemia and the cessation of clinical signs. Persistent infection was characterized by a clearly defined period of primary bacteraemia followed by recurrent cycles of bacteraemia, usually lasting a few days and of lower magnitude, interspersed by negative periods of variable duration in which bacterial DNA could not be detected.

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