Browsing by Author "Ramos, J."
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- Effects of salts on Debaryomyces hansenii and Saccharomyces cerevisiae under stress conditionsPublication . Almagro, A.; Prista, C.; Castro, S.; Quintas, Célia; Madeira Lopes, A.; Ramos, J.; Loureiro-Dias, M. C.The effect of Na+ and K+ on growth and thermal death of Debaryomyces hansenii and Saccharomyces cerevisiae were compared under stress conditions as those commonly found in food environments. At the supraoptimal temperature of 34 degrees C both cations at concentrations of 0.5 M stimulated growth of D. hansenii, while K+ had no effect and Na+ inhibited growth of S. cerevisiae. At 8 degrees C, close to the minimum temperature for growth in both species, both cations inhibited both yeasts, this effect being more pronounced with Na+ in S. cerevisiae. At extreme pH values (7.8 and 3.5) both cations at concentrations of 0.25 M stimulated B. hansenii while Na+ inhibited S. cerevisiae. K+ inhibited this yeast at pH 3.5. Thermal inactivation rates, measured at 38 degrees C in D. hansenii and at 48 degrees C in S. cerevisiae, decreased in the presence of both cations. This protective effect could be observed in a wider range of concentrations in D. hansenii. These results call the attention to the fact that not all yeasts have the same behaviour on what concerns synergy or antagonism of salt together with other stress factors and should be taken into consideration in the establishment of food preservation procedures. (C) 2000 Elsevier Science B.V. All rights reserved.
- Low Golimumab trough levels at week 6 are associated with poor clinical, endoscopic and histological outcomes in ulcerative colitis patients: pharmacokinetic and pharmacodynamic sub-analysis of the evolution studyPublication . Magro, F.; Lopes, S.; Silva, M.; Coelho, R.; Portela, F.; Branquinho, D.; Correia, L.; Fernandes, S.; Cravo, M.; Caldeira, Paulo; Sousa, Helena Tavares; Patita, M.; Lago, P.; Ramos, J.; Afonso, J.; Redondo, I.; Machado, P.; Cornillie, F.; Lopes, J.; Carneiro, F.Background and Aims: Golimumab has an established exposure-response relationship in patients with ulcerative colitis [UC]. However, the association of serum golimumab trough levels [TL] with objective markers of disease activity, such as endoscopic and histological activity scores and concentrations of biomarkers, remains less understood. This report describes the relationship of serum golimumab TL at the end of the induction period [Week 6] with clinical, endoscopic, histological, and biomarker parameters. Methods: This was an open-label, uncontrolled, prospective and interventional study. Moderate to severely active UC patients naive to biologic therapy were treated with golimumab. Serum golimumab TL and faecal calprotectin levels were measured at baseline [Week 0 of induction] and Week 6. Results: A total of 34 patients completed the induction phase [Week 6] and were included in this analysis. Overall, 47.1% and 14.7% of patients achieved clinical response and remission with significantly higher serum golimumab TL in patients with early response or remission [3.7 mu g/mL vs 1.3 mu g/mL, p = 0.0013; and 3.1 mu g/mL vs 1.7 mu g/mL, p = 0.0164, respectively]. In addition, golimumab TL were significantly higher in patients achieving histological remission [4.2 mu g/mL vs 1.7 mu g/mL, p = 0.0049]. Week 6 golimumab TL were inversely correlated with the total Mayo score [rs = -0.546; p = 0.0008], the Mayo endoscopic subscore [rs = -0.381; p = 0.0262], the Geboes histological activity score [rs = -0.464; p = 0.0057], and faecal calprotectin levels [rs = -0.497; p = 0.0044]. Conclusions: A higher early exposure to golimumab is associated with a better objective response in active UC patients and appears to drive the outcome at Week 6.
- Proactive therapeutic drug monitoring of infliximab: a comparative study of a new point-of-care quantitative test with two established ELISA assaysPublication . Afonso, J.; Lopes, S.; Gonçalves, R.; Caldeira, Paulo; Lago, P.; Sousa, Helena Tavares; Ramos, J.; Gonçalves, A. R.; Ministro, P.; Rosa, I.; Vieira, A. I.; Dias, C. C.; Magro, F.BackgroundTherapeutic drug monitoring is a powerful strategy known to improve the clinical outcomes and to optimise the healthcare resources in the treatment of autoimmune diseases. Currently, most of the methods commercially available for the quantification of infliximab (IFX) are ELISA-based, with a turnaround time of approximately 8h, and delaying the target dosage adjustment to the following infusion.AimTo validate the first point-of-care IFX quantification device available in the market - the Quantum Blue Infliximab assay (Buhlmann, Schonenbuch, Switzerland) - by comparing it with two well-established methods.MethodsThe three methods were used to assay the IFX concentration of spiked samples and of the serum of 299 inflammatory bowel diseases (IBD) patients undergoing IFX therapy.ResultsThe point-of-care assay had an average IFX recovery of 92%, being the most precise among the tested methods. The Intraclass Correlation Coefficients of the point-of-care IFX assay vs. the two ELISA-based established methods were 0.889 and 0.939. Moreover, the accuracy of the point-of-care IFX compared with each of the two reference methods was 77% and 83%, and the kappa statistics revealed a substantial agreement (0.648 and 0.738).ConclusionsThe Quantum Blue IFX assay can successfully replace the commonly used ELISA-based IFX quantification kits. This point-of-care IFX assay is able to deliver the results within 15min makes it ideal for an immediate target concentration adjusted dosing. Moreover, it is a user-friendly desktop device that does not require specific laboratory facilities or highly specialised personnel.