6 research outputs found

    Effectiveness of surgical banding for high flow in brachial artery-based hemodialysis vascular access

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    OBJECTIVE: Autogenous arteriovenous hemodialysis (HD) access may develop high flow (>2 L/min) over time. Reducing flow volume of a high-flow access (HFA) using a surgical banding technique has been reported to be successful in the short-term. The aim of this study was to evaluate the efficacy of banding in HFAs in terms of freedom from recurrence of high flow during a 1-year follow-up. METHODS: All HD patients undergoing surgical banding of an HFA during an 8-year period in three hospitals were retrospectively studied. Access flow data, freedom of recurrent high flow, and complications were analyzed during a 12-month postoperative observation period. RESULTS: A total of 50 patients (30 males; age, 51 +/- 2 years) were available for analysis. Banding was performed 30 +/- 6 months after arteriovenous access construction. Most of the HFA patients (56%) required medication for hypertension, but diabetes mellitus and peripheral arterial obstructive disease were seldom observed (6% and 12%, respectively). Most HFAs (96%) were brachial artery-based fistulas (brachiocephalic: 56%, basilic vein transposition: 40%, radiocephalic: 4%). Banding initially reduced access flow by >50% (3070 +/- 95 vs 1490 +/- 105 mL/min, P 2 L/min) developed in 52% of the patients during the observation period. Young age (45 +/- 3 vs 57 +/- 3 years; P = .02) and an access flow >1 L/min immediately after banding (P = .03) were risk factors for recurrent high flow. CONCLUSIONS: An immediate postbanding access flow >1 L/min and young age are risk factors for recurrent high flow in a banded brachial artery-based HD access during a 1-year follow-up

    Optimization of biomass, vitamins, and carotenoid yield on light energy in a flat-panel reactor using the A-stat technique

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    Acceleration-stat (A-stat) cultivations in which the dilution rate is continuously changed at a constant acceleration rate, leading to different average light intensities inside the photobioreactor, can supply more information and reduce experimental time compared with chemostat cultivations. The A-stat was used to optimize the biomass and product yield of continuous cultures of the microalgae D. tertiolecta in a flat-panel reactor. In this study, four different accelerations were studied, a pseudo steady state was maintained at acceleration rates of 0.00016 and 0.00029 h-2 and results were similar to those of the chemostat. An increase in the acceleration rate led to an increase in the deviation between results obtained in the A-stat and in the chemostats. We concluded that it is advantageous to use the A-stat instead of chemostats to determine culture characteristics and optimize a specific photobioreactor. The effect of average light intensity inside the photobioreactor on the production of vitamins C and E, lutein, and β-carotene was studied using the A-stat. The highest concentrations of these products were 3.48 ± 0.46, 0.33 ± 0.06, 5.65 ± 0.24, and 2.36 ± 0.38 mg g-1 respectively. These results were obtained at different average light intensities, showing the importance of optimizing each product on light intensity. © 2004 Wiley Periodicals, Inc

    Optimization of biomass, vitamins, and carotenoid yield on light energy in a flat-panel reactor using the A-stat technique

    No full text
    Acceleration-stat (A-stat) cultivations in which the dilution rate is continuously changed at a constant acceleration rate, leading to different average light intensities inside the photobioreactor, can supply more information and reduce experimental time compared with chemostat cultivations. The A-stat was used to optimize the biomass and product yield of continuous cultures of the microalgae D. tertiolecta in a flat-panel reactor. In this study, four different accelerations were studied, a pseudo steady state was maintained at acceleration rates of 0.00016 and 0.00029 h2 and results were similar to those of the chemostat. An increase in the acceleration rate led to an increase in the deviation between results obtained in the A-stat and in the chemostats. We concluded that it is advantageous to use the A-stat instead of chemostats to determine culture characteristics and optimize a specific photobioreactor. The effect of average light intensity inside the photobioreactor on the production of vitamins C and E, lutein, and h-carotene was studied using the A-stat. The highest concentrations of these products were 3.48 F 0.46, 0.33 F 0.06, 5.65 F 0.24, and 2.36 F 0.38 mg g1, respectively. These results were obtained at different average light intensities, showing the importance of optimizing each product on light intensity

    Proteomics of human liver membrane transporters: a focus on fetuses and newborn infants

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    Contains fulltext : 196426.pdf (Publisher’s version ) (Open Access)BACKGROUND: Hepatic membrane transporters are involved in the transport of many endogenous and exogenous compounds, including drugs. We aimed to study the relation of age with absolute transporter protein expression in a cohort of 62 mainly fetus and newborn samples. METHODS: Protein expressions of BCRP, BSEP, GLUT1, MCT1, MDR1, MRP1, MRP2, MRP3, NTCP, OCT1, OATP1B1, OATP1B3, OATP2B1 and ATP1A1 were quantified with LC-MS/MS in isolated crude membrane fractions of snap-frozen post-mortem fetal and pediatric, and surgical adult liver samples. mRNA expression was quantified using RNA sequencing, and genetic variants with TaqMan assays. We explored relationships between protein expression and age (gestational age [GA], postnatal age [PNA], and postmenstrual age); between protein and mRNA expression; and between protein expression and genotype. RESULTS: We analyzed 36 fetal (median GA 23.4weeks [range 15.3-41.3]), 12 premature newborn (GA 30.2weeks [24.9-36.7], PNA 1.0weeks [0.14-11.4]), 10 term newborn (GA 40.0weeks [39.7-41.3], PNA 3.9weeks [0.3-18.1]), 4 pediatric (PNA 4.1years [1.1-7.4]) and 8 adult liver samples. A relationship with age was found for BCRP, BSEP, GLUT1, MDR1, MRP1, MRP2, MRP3, NTCP, OATP1B1 and OCT1, with the strongest relationship for postmenstrual age. For most transporters mRNA and protein expression were not correlated. No genotype-protein expression relationship was detected. DISCUSSION AND CONCLUSION: Various developmental patterns of protein expression of hepatic transporters emerged in fetuses and newborns up to four months of age. Postmenstrual age was the most robust factor predicting transporter expression in this cohort. Our data fill an important gap in current pediatric transporter ontogeny knowledge

    Patients with a Ruptured Abdominal Aortic Aneurysm Are Better Informed in Hospitals with an “EVAR-preferred” Strategy: An Instrumental Variable Analysis of the Dutch Surgical Aneurysm Audit

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