Evaluación de la anticoagulación con rivaroxaban, en pacientes con fibrilación auricular no valvular de reciente diagnóstico / Evaluation of oral anticoagulation with rivaroxaban, in patients with new onset non valvular atrial fibrillation

Background: Atrial fibrillation (AF) generates a hypercoagulable state with an increased thrombin generation and raised levels of thrombin-antithrombin complexes, which results in a high risk of stroke and thromboembolism. Aim: To evaluate the anticoagulant effect of rivaroxaban by anti-Xa factor activity and its correlation with thrombin-antithrombin complexes, thrombin generation and prothrombin time in patients newly diagnosed with non-valvular AF. Patients and Methods: Prospective study in patients with indication of anticoagulation. Demographic variables, cardiovascular risk factors, CHA2DS2-VASc and HAS-BLED scores were recorded. Blood samples were taken at baseline, at 3 and 24 hours after the administration of the drug and at 30 days. Rivaroxaban levels, anti-Xa activity, prothrombin time, thrombin generation and plasma levels of thrombin-antithrombin complexes were determined. Results: We studied 20 patients aged 76.3 ± 8.0 years (60% female) with a CHA2DS2-VASc score > 2 points. The anti-Xa factor activity correlated with rivaroxaban plasma levels at 3 hours (r = 0.61, p < 0.01), at 24 hours (r = 0.85, p < 0.01) and at 30 days (r = 0.99, p < 0.01), with prothrombin time at 3 hours (r = -0.86, p = 0.019) and at 30 days (r = -0.63, p = 0.02) and with a sustained decrease in thrombin generation at 30 days of follow-up (r = -0.74, p < 0.01). There was no correlation with thrombin-antithrombin complexes (r = -0.02, p = 0.83). Conclusions: Rivaroxaban consistently inhibited the mild pro-coagulant state found in newly diagnosed non-valvular AF patients through the first 24 hours and this effect was maintained at 30 days. Plasma levels of the drug correlated with anti-Xa factor activity, thrombin generation and prothrombin time

Atividade enzimática, produção de slime e sensibilidade a antifúngicos de Candida sp / Enzymatic activity, slime production and antifungal agent sensitivity of Candida sp

A habilidade de Candida spp secretar enzimas extracelulares e slime tem sido associada como fatores de patogenicidade. Do total de 37 cepas de Candida sp, 100 por cento foram produtoras de proteinase, 83,8 por cento fosfolipase, 64,9 por cento slime e 100 por cento sensíveis ao fluconazol e itraconazol. Foram encontradas 17 tipagens (enzima/slime). Esta metodologia apresentou um bom índice discriminatório (D=0,93) podendo ser utilizado na caracterização fenotípica das leveduras.

Abilith of Candida spp to secrete extracellular enzymes and slime has been associated as pathogenicity factors. Out of a total of 37 strains of Candida sp, 100 percent were proteinase producers, 83.8 percent were phospholipase producers, 64.9 percent were slime producers and 100 percent were sensitive to fluconazole and itraconazole. Seventeen typings (enzymes/slime) were found. This methodology presented a good discrimination rate (D = 0.93) and could be used for phenotypic characterization of yeasts.

Giardia duodenalis: analysis of secreted proteases upon trophozoite-epithelial cell interaction in vitro

Protease secretion by Giardia duodenalis trophozoites upon interaction with epithelial cells and its association with the parasite adhesion was studied in co-cultures of parasites with IEC6 epithelial cell monolayers in the presence or absence of protease inhibitors. Proteolytic activity in supernatants from trophozoites was enhanced when they were co-cultured with IEC6 cells. This activity was strongly inhibited by pre-incubation of live trophozoites with E-64 and TPCK and a concomitant inhibition of parasite adhesion to IEC6 cells was observed. These data suggest that trophozoites secrete cysteine-type proteases that play a role in the adhesion of G. duodenalis to epithelial cells.

Slime production and proteinase activity of Candida species isolated from blood samples and the comparison of these activities with minimum inhibitory concentration values of antifungal agents

Slime and proteinase activity of 54 strains consisting of 19 Candida parapsilosis and 35 C. albicans strains isolated from blood samples were investigated in this study. Ketoconazole, amphothericin B, and fluconazole susceptibility of Candida species were compared with slime production and proteinase activity of these species. For both Candida species, no correlation was detected between the slime activity and minimum inhibitory concentration (MIC) values of the three antifungal agents. For both Candida species no correlation was detected between the proteinase activity and the MIC values of amphothericin B, and fluconazole however, statistically significant difference, was determined between the proteinase activity and MIC values of ketoconazole (p = 0.007). Slime production was determined by using modified Christensen macrotube method and proteinase activity was measured by the method of Staib. Antifungal susceptibility was determined through the guidelines of National Committee for Laboratory Standards (NCCLS M27-A).