Fabiana Horn

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Here we describe the purification and characterization of a vitellin (VT) degrading cysteine endopeptidase (VTDCE) from eggs of the hard tick Boophilus microplus. A homogeneous enzyme preparation was obtained by chromatographic fractionation on ion-exchange and gel filtration columns and an autolysis step. This step consisted of incubation of a semipurified(More)
Recent epidemiological and dietary intervention studies in animals and humans have suggested that diet-derived flavonoids, in particular quercetin, may play a beneficial role by preventing or inhibiting tumorigenesis. The aim of this study was to evaluate whether quercetin may act differently on cancer and normal neuronal tissue. In order to investigate(More)
An anticoagulant was isolated from saliva of the cattle tick Boophilus microplus. Crude saliva prolonged both recalcification time and prothrombin time in assays with bovine plasma. It also inhibited thrombin, but not fXa, amidolytic activity. We purified the antithrombin activity by a combination of gel filtration, anion exchange, and affinity(More)
Saliva of the cattle tick Boophilus microplus contains two thrombin inhibitors, BmAP and microphilin. This work presents the purification and characterization of microphilin. It was purified from the saliva by gel filtration, ultrafiltration through a 3 kDa cut-off membrane and affinity chromatography in a thrombin-Sepharose column. Analysis by mass(More)
Avian pathogenic Escherichia coli (APEC) are responsible for extraintestinal diseases, called colibacillosis, in avian species. The most severe manifestation of the disease is colisepticemia that usually starts at the respiratory tract and may result in bird death. However, it is not yet clear how APEC cross the respiratory epithelium and get into the(More)
We investigated the importance of the phosphoinositide3-kinase (PI3K) pathway in CA1 and dentate gyrus (DG) areas of hippocampus by exposing organotypic cultures to LY294002, a PI3K inhibitor, or to oxygen and glucose deprivation (OGD) for up to 21 hours. LY294002 induced increased propidium iodide (PI) uptake and caspase 3/7 activity in both regions, with(More)
The purpose of this study was to compare histopathological changes in the lungs of chickens infected with avian pathogenic (APEC) and avian fecal (A(fecal)) Escherichia coli strains, and to analyze how the interaction of the bacteria with avian macrophages relates to the outcome of the infection. Chickens were infected intratracheally with three APEC(More)
We characterized 144 Escherichia coli isolates from severe cellulitis lesions in broiler chickens from South Brazil. Analysis of susceptibility to 15 antimicrobials revealed frequencies of resistance of less than 30% for most antimicrobials except tetracycline (70%) and sulphonamides (60%). The genotyping of 34 virulence-associated genes revealed that all(More)
Uropathogenic Escherichia coli (UPEC) is responsible for the majority of urinary tract infections (UTIs), which are some of the world's most common bacterial infections of humans. Here, we examined the role of FNR (fumarate and nitrate reduction), a well-known global regulator, in the pathogenesis of UPEC infections. We constructed an fnr deletion mutant of(More)
Glioma is the most frequent and malignant primary human brain tumor with dismal prognosis despite multimodal therapy. Resveratrol and quercetin, two structurally related and naturally occurring polyphenols, are proposed to have anticancer effects. We report here that resveratrol and quercetin decreased the cell number in four glioma cell lines but not in(More)