ABSTRACT
Peritoneal dialysis is one of the main renal replacement treatments. However, long-term peritoneal dialysis keeps the peritoneum in contact with the sugar-containing nonphysiological peritoneal fluid, which leads to recurrent peritonitis, peritoneal fibrosis, and failure of ultrafiltration. Transforming growth factor-ß1 (TGF-ß1), related cytokines, and inflammatory factors are closely related to peritoneal fibrosis. Sulodexide (SLX) is a new type of glycosaminoglycan preparation, which is involved in the formation of an anionic charge barrier and can maintain the selective permeability of vascular endothelial cells. In this study, the innovative analysis of SLX specifically prevents the process of peritoneal dialysis peritoneal fibrosis by downregulating the expression of TGF-ß1 and its signaling pathway molecules. We randomly divided 30 rats into three groups. The blank control group received no treatment. The peritoneal dialysis model group was injected with 4.25% peritoneal dialysate (PDF) 20 ml daily, and the SLX group was injected with 4.25% PDF 20 ml + sulodexide (SLX) 20 mg/kg daily. After 8 weeks of dialysis, the rats were sacrificed, and the peritoneal function test was performed to determine the amount of glucose transport and ultrafiltration. The thickness of peritoneal per unit area was observed under high magnification. The level of inflammation in peritoneal tissue and the expression of TGF-ß1/Smad were detected. The results showed that SLX can significantly improve peritoneal tissue thickening and inflammation, can downregulate the expression of TGF-ß1, Smad2, Smad3, and Smad7 in peritoneal tissue, and improve the progression of peritoneal fibrosis.
ABSTRACT
Although the eutrophication phenomenon has been studied for a long time, there are still no quantifiable parameters available for a comprehensive assessment of its impacts on the water environment. As contamination alters the thermodynamic equilibrium of a water system to a state of imbalance, a novel method was proposed, in this study, for its quantitative evaluation. Based on thermodynamic analyses of the algal growth process, the proposed method targeted, both theoretically and experimentally, the typical algae species encountered in the water environment. By calculating the molar enthalpy of algae biomass production, the heat energy dissipated in the photosynthetic process was firstly evaluated. The associated entropy production (ΔS) in the aquatic system could be then obtained. For six algae strains of distinct molecular formulae, the heat energy consumed for the production of a unit algal biomass was found to proportionate to the mass of nitrogen (N) or phosphorus (P) uptake through photosynthesis. A proportionality relationship between ΔS and the algal biomass with a coefficient circa 44kJ/g was obtained. By the principle of energy conservation, the heat energy consumed in the process of algae biomass production is stored in the algal biomass. Furthermore, by measuring the heat of combustion of mature algae of Microcystis flos-aquae, Anabaena flos-aquae, and Chlorella vulgaris, the proportionality relationships between the heat energy and the N and P contents were validated experimentally at 90% and 85% confidence levels, respectively. As the discharge of excess N and P from domestic wastewater treatment plants is usually the main cause of eutrophication, the proposed impact assessment approach estimates that for a receiving water body, the ΔS due to a unit mass of N and P discharge is 268.9kJ/K and 1870.1kJ/K, respectively. Consequently, P discharge control would be more important for environmental water protection.