205 research outputs found
Effect of Different Stages of Chronic Kidney Disease and Renal Replacement Therapies on Oxidant-Antioxidant Balance in Uremic Patients
Oxidative stress seems to be involved in the path physiology of cardiovascular complications of chronic kidney disease (CKD). In this study, we determined the effect of different stages of CKD and substitutive therapies on oxidative stress. One hundred sixty-seven patients (age: 44±06 years; male/female: 76/91) with CKD were divided into 6 groups according to the National Kidney Foundation classification. Prooxidant status was assessed by assaying thiobarbituric acid reactive substances, hydroperoxides, and protein carbonyls. Antioxidant defence was performed by analysis of superoxide dismutase, catalase, glutathione peroxidase, glutathione reductase, vitamin E, Iron, and bilirubin. TBARS and LPO were higher in HD patients compared to other groups (P<0.001), while protein carbonyls were more increased in PD patients. The antioxidant enzymes were declined already at severe stage of CKD and they were declined notably in HD patients (P<0.001). Similar observation was found for vitamin E, Fe, and bilirubin where we observed a significant decrease in the majority of study groups, especially in HD patients (P<0.001). The evolution of CKD was associated with elevated OS. HD accentuates lipid, while PD aggravates protein oxidation. However, the activity of antioxidant enzymes was altered by impaired renal function and by both dialysis treatments
Strong and weak Allee effects and chaotic dynamics in Richards' growths
In this paper we define and investigate generalized Richards' growth models with strong and weak Allee effects and no Allee effect. We prove the transition from strong Allee effect to no Allee effect, passing through the weak Allee effect, depending on the implicit conditions, which involve the several parameters considered in the models. New classes of functions describing the existence or not of Allee effect are introduced, a new dynamical approach to Richards' populational growth equation is established. These families of generalized Richards' functions are proportional to the right hand side of the generalized Richards' growth models proposed. Subclasses of strong and weak Allee functions and functions with no Allee effect are characterized. The study of their bifurcation structure is presented in detail, this analysis is done based on the configurations of bifurcation curves and symbolic dynamics techniques. Generically, the dynamics of these functions are classified in the following types: extinction, semi-stability, stability, period doubling, chaos, chaotic semistability and essential extinction. We obtain conditions on the parameter plane for the existence of a weak Allee effect region related to the appearance of cusp points. To support our results, we present fold and flip bifurcations curves and numerical simulations of several bifurcation diagrams
Effect of hemodialysis and peritoneal dialysis on redox status in chronic renal failure patients: a comparative study
<p>Abstract</p> <p>Objective</p> <p>To investigate the effects of hemodialysis (HD) and periotoneal dialysis (PD) on oxidative stress in chronic renal failure patients (CRF).</p> <p>Methods</p> <p>20 HD patients (M/F: 8/12, 36 ± 12 years) and 20 PD patients (M/F: 10/10, 40 ± 8 years) were compared with 20 end stage renal failure patients (CRF) (M/F: 4/16, 61 ± 13 years).</p> <p>Results</p> <p>Thiobarbituric acid reactive substances (TBARS) values were elevated in HD and decreased in PD compared to CRF (P < 0.05). TBARS-VLDL and TBARS-HDL<sub>2 </sub>were decreased in HD and PD, compared to CRF (p < 0.05). TBARS-LDL were higher in HD compared to CRF (p < 0.05). No significant difference in TBARS-HDL<sub>3 </sub>values between the three groups. Carbonyls were increased in HD (p < 0.05) and PD (p < 0.01) compared to CRF. Plasma superoxide dismutase activity (SOD) was decreased in HD compared to CRF and PD (P < 0.05). Glutathion peroxidase activity (GSH-Px) was decreased in HD and PD (P < 0.005), compared to CRF. Decrease in catalase activity was noted only in PD compared to CRF (P < 0.05). An increase in nitric oxide was noted in HD compared to CRF (p < 0.05). Albumin concentrations were higher in HD and PD compared to CRF (P < 0.001). Whereas uric acid concentrations were decreased in HD (P < 0.001) compared to CRF and PD. Bilirubin values were similar in all groups. Increased values of iron were noted in HD and PD, compared to PD (p < 0.001).</p> <p>Conclusion</p> <p>HD and PD aggravate oxidative stress generated by uremia. HD accentuates lipid and protein peroxidation, while PD aggravates protein oxidation. However, the activity of antioxidant enzymes was altered by both dialysis treatments.</p
UE2020 : le processus de Lisbonne revisité
Las páginas 119-138 no son accesibles por derechos de autor.Este libro recoge las ponencias presentadas en el "11 International Workshop", "EU2020: The Lisbon Process revisited", celebrado en Madrid el 28 de septiembre de 2011, en el marco del Proyecto de lnvestigación de la Acción J. Monnet, n" 154460-LLP-1-2009-1-ES-AJM-CL, y del Proyecto del Programa Propio de Investigación de la Universidad Carlos Ill de Madrid, n" 2011/003 73/001, y, con el auspicio de la Embajada de la República de Francia en España
Effect of Different Stages of Chronic Kidney Disease and Renal Replacement Therapies on Oxidant-Antioxidant Balance in Uremic Patients
Oxidative stress seems to be involved in the path physiology of cardiovascular complications of chronic kidney disease (CKD). In this study, we determined the effect of different stages of CKD and substitutive therapies on oxidative stress. One hundred sixtyseven patients (age: 44 ± 06 years; male/female: 76/91) with CKD were divided into 6 groups according to the National Kidney Foundation classification. Prooxidant status was assessed by assaying thiobarbituric acid reactive substances, hydroperoxides, and protein carbonyls. Antioxidant defence was performed by analysis of superoxide dismutase, catalase, glutathione peroxidase, glutathione reductase, vitamin E, Iron, and bilirubin. TBARS and LPO were higher in HD patients compared to other groups ( < 0.001), while protein carbonyls were more increased in PD patients. The antioxidant enzymes were declined already at severe stage of CKD and they were declined notably in HD patients ( < 0.001). Similar observation was found for vitamin E, Fe, and bilirubin where we observed a significant decrease in the majority of study groups, especially in HD patients ( < 0.001). The evolution of CKD was associated with elevated OS. HD accentuates lipid, while PD aggravates protein oxidation. However, the activity of antioxidant enzymes was altered by impaired renal function and by both dialysis treatments
Wastewater irrigation: the state of play
As demand for fresh water intensifies, wastewater is frequently being seen as a valuable resource. Furthermore, wise reuse of wastewater alleviates concerns attendant with its discharge to the environment. Globally, around 20 million ha of land are irrigated with wastewater, and this is likely to increase markedly during the next few decades as water stress intensifies. In 1995, around 2.3 billion people lived in water-stressed river basins and this could increase to 3.5 billion by 2025. We review the current status of wastewater irrigation by providing an overview of the extent of the practice throughout the world and through synthesizing the current understanding of factors influencing sustainable wastewater irrigation. A theme that emerges is that wastewater irrigation is not only more common in water-stressed regions such as the Near East, but the rationale for the practice also tends to differ between the developing and developed worlds. In developing nations, the prime drivers are livelihood dependence and food security, whereas environmental agendas appear to hold greater sway in the developed world. The following were identified as areas requiring greater understanding for the long-term sustainability of wastewater irrigation: (i) accumulation of bioavailable forms of heavy metals in soils, (ii) environmental fate of organics in wastewater-irrigated soils, (iii) influence of reuse schemes on catchment hydrology, including transport of salt loads, (iv) risk models for helminth infections (pertinent to developing nations), (v) microbiological contamination risks for aquifers and surface waters, (vi) transfer efficiencies of chemical contaminants from soil to plants, (vii) health effects of chronic exposure to chemical contaminants, and (viii) strategies for engaging the public.<br /
Praxisbericht Droit européen: Suisse – Union européenne = Europarecht: Schweiz – Europäische Union
Recent developments in the legal relationship between Switzerland and the European Union, legislative development and, in particular, case law (Court of Justice of the European Union and of the Swiss Federal Tribunal)
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