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- ItemSomente MetadadadosCustomized bicarbonate buffered dialysate and replacement solutions for continuous renal replacement therapies: Effect of crystallization on the measured levels of electrolytes and buffer(Blackwell Publishing Inc, 2001-11-01) Maccariello, E.; Rocha, E.; Dalboni, Maria Aparecida [UNIFESP]; Ferreira, A. T.; Draibe, S.; Cendoroglo, M.; Universidade Federal de São Paulo (UNIFESP); Universidade Federal Fluminense (UFF)The aim of this study was to investigate the impact of the addition of calcium to bicarbonate solutions for continuous renal replacement therapy (CRRT). We tested single bag (bicarbonate and calcium mixed 24 It before testing) and double bag solutions (mixed immediately before) with and without the addition of 4 mEq/L of acetate. Prescribed calcium varied from 0 to 5 mEq/L. All test solutions containing calcium showed crystallization at light microscopy. the double bag solutions decreased but did not prevent crystallization. the addition of acetate did not interfere with crystallization. Crystallization. as measured by the weight of the crystals after filtration of the solutions, showed a significant positive correlation with the calcium deficit (prescribed minus measured) and with partial pressure of carbon dioxide. the measured level of calcium was lower than expected and correlated with crystallization. Our results suggest that the use of bicarbonate solutions containing calcium as replacement fluids for CRRT is a potentially unsafe procedure.
- ItemAcesso aberto (Open Access)Estabilidade de comprimidos de liberação controlada baseados em hidroxietilcelulose(Universidade Federal de São Paulo (UNIFESP), 2016-02-25) Gaiotto, Cristina Aparecida Andrade Raymundo [UNIFESP]; Tada, Dayane Batista [UNIFESP]; Universidade Federal de São Paulo (UNIFESP)Cellulose derivatives are polymers commonly used for drug delivery. In this work one of these derivatives, the hydroxiethylcellulose has been applied in the formulation of compressed tablets for controlled release purposes. The tablets were produced by using the same excipients normally used in the commercially available tablets and caffeine was used as model drug. The characterization of raw materials and tablets were performed by using the following techniques: Differential Scanning Calorimetry analysis (DSC), spectroscopic measurements of Raman and UV/VIS, scanning electron microscopy (SEM). The swelling behavior of the polymeric matrix was evaluated by immersion in water and exposition to atmospheric humidity. The drug release profile of the tablets was obtained in ?in vitro? assays in water. The mechanisms of drug release and swelling were characterized by adjusting kinetic data to Higuchi, Korsmeyer and Vergnaud model. Additionally to the establishment of an appropriated formulation for controlled release of caffeine, the present work has identified the effects of compression pressure and storage over the drug release kinetic profile of the tablets. It was observed that the higher compression pressure generates tablets with slower drug release in a anomalous mechanism of release and swelling. The storage under 75/%RH and 30/ºC and 40/ºC increased the rate of drug release in both types of tablets (compressed at higher and at lower pressure). This change has been identified as a consequence of the increased water content of the tablets as well as a result of the relaxation of the polymeric chains due to the increased temperature. Overal, the results obtained, suggested that a criterious planning and combination of raw materials in the design of formulations as well as the set up of the parameters during the production of tablets are critical points to the success of a system for controlled release purposes. Besides, monitoring storage conditions as temperature and humidity is essencial in order to guarantee the controlled release behavior of HEC-based tablets.
- ItemAcesso aberto (Open Access)Interaction between Shiga Toxin and Monoclonal Antibodies: Binding Characteristics and in Vitro Neutralizing Abilities(Mdpi Ag, 2012-09-01) Rocha, Leticia B.; Luz, Daniela E.; Moraes, Claudia T. P.; Caravelli, Andressa; Fernandes, Irene; Guth, Beatriz Ernestina Cabilio [UNIFESP]; Horton, Denise S. P. Q.; Piazza, Roxane M. F.; Butantan Inst; Universidade Federal de São Paulo (UNIFESP)Monoclonal antibodies (MAbs) have been employed either for diagnosis or treatment of infections caused by different pathogens. Specifically for Shiga toxin-producing Escherichia coli (STEC), numerous immunoassays have been developed for STEC diagnosis, showing variability in sensitivity and specificity when evaluated by reference laboratories, and no therapy or vaccines are currently approved. Thus, the aim of this work was the characterization of the interaction between MAbs against Stx1 and Stx2 toxins and their neutralizing abilities to enable their use as tools for diagnosis and therapy. the selected clones designated 3E2 (anti-Stx1) and 2E11 (anti-Stx2) were classified as IgG1. 3E2 recognized the B subunit of Stx1 with an affinity constant of 2.5 x 10(-10) M, detected as little as 6.2 ng of Stx1 and was stable up to 50 degrees C. in contrast, 2E11 recognized the A subunit of Stx2, was stable up to 70 degrees C, had a high dissociation constant of 6.1 x 10(-10) M, and detected as little as 12.5 ng of Stx2. Neutralization tests showed that 160 ng of 3E2 MAb inhibited 80% of Stx1 activity and 500 mu g 2E11 MAb were required for 60% inhibition of Stx2 activity. These MAb amounts reversed 25 to 80% of the cytotoxicity triggered by different STEC isolates. in conclusion, these MAbs show suitable characteristics for their use in STEC diagnosis and encourage future studies to investigate their protective efficacy.