Dialysis solution containing hyaluronan: Effect on peritoneal permeability and inflammation in rats

Dialysis solution containing hyaluronan: Effect on peritoneal permeability and inflammation in rats.BackgroundHyaluronan (HA), a high molecular weight mucopolysaccharide found in interstitial tissues and fluid, is lost from the peritoneal cavity during peritoneal dialysis. In order to determine the role of HA in peritoneal function, we investigated the effects of exogenous HA on peritoneal permeability, markers of intraperitoneal inflammation, and peritoneal morphology in rats exposed to peritoneal dialysis solution for four weeks.MethodsWistar rats were infused intraperitoneally, twice daily, with conventional, hypertonic dialysis solution (Dianeal 3.86%; control) or Dianeal solution containing 10 mg/dL of high molecular weight HA. Peritoneal permeabilities and clearances of solutes and protein were determined using a modified peritoneal permeability test (peritoneal equilibration test) at the beginning and the end of the treatment. Peritoneal volume and ultrafiltration were determined using a macromolecular marker and by gravimetric methods. Peritoneal inflammation was determined by cell counts and differential and by the measurement of cytokine concentrations in the dialysate effluent. Peritoneal thickness and HA content were determined in liver and mesentery biopsies taken at the end of the experiment.ResultsAfter four weeks of exposure to the dialysis solution, transperitoneal protein equilibration was significantly lower in HA-treated rats compared with rats treated with Dianeal alone (46% lower for albumin, P < 0.001; 33% lower for total protein, P < 0.001). The total drained volume after a four hour dwell was 29% higher in the HA group compared with the control (P < 0.001), yielding a positive net ultrafiltration in the HA group versus a negative net ultrafiltration in controls. Peritoneal clearances of urea and creatinine tended to be elevated in HA-treated rats, while clearances of total protein and albumin tended to be lower. Dialysate effluent from rats exposed to HA contained a lower percentage of neutrophils (8.8 ± 6.7 vs. 22.8 ± 9.5%, P < 0.01) and lower levels of the cytokines, tumor necrosis factor-α (11.2 ± 14.7 vs. 42.3 ± 35.3 pg/mL, P < 0.05) and monocyte chemoattractant protein-1 MCP-1 (72.0 ± 86.5 vs. 402.4 ± 258.3 pg/mL, P < 0.02), compared with rats treated with Dianeal alone. The thickness of the peritoneal interstitium showed a similar increase in both groups, but mesenteric tissue from the HA group contained more HA (48%, P < 0.01) than tissue from control animals.ConclusionsThe addition of HA to peritoneal dialysis solution decreases protein permeability, increases ultrafiltration, and decreases cytokine levels and the proportion of peritoneal neutrophils in dialysate from rats exposed to hypertonic dialysis solution. These results suggest that exogenous HA may help to protect the peritoneal membrane during exposure to dialysis solutions. These benefits, if sustained in the clinical setting, could lead to improvements in the therapy of peritoneal dialysis

Reductive dissolution and metal transport in lake coeur d alenesediments

The benthic sediments in Lake Coeur d Alene, northern Idaho,have been contaminated by metals (primarily Zn, Pb, and Cu) from decadesof upstream mining activities. As part of ongoing research on thebiogeo-chemical cycling of metals in this area, a diffusivereactive-transport model has been developed to simulate metal transportin the lake sediments. The model includes 1-D inorganic diffusivetransport coupled to a biotic reaction network with multiple terminalelectron acceptors under redox disequilibrium conditions. Here, the modelis applied to evaluate the competing effects of heavy-metal mobilizationthrough biotic reductive dissolution of Fe(III) (hydr)oxides, andimmobilization as biogenic sulfide minerals. Results indicate that therelative rates of Fe and sulfate reduction could play an important rolein metal transport through the envi-ronment, and that the formation of(bi)sulfide complexes could significantly enhance metal solubility, aswell as desorption from Fe hydroxides

From Romantic Gothic to Victorian Medievalism: 1817 and 1877

&quot;The Cambridge History of the Gothic was conceived in 2015, when Linda Bree, then Editorial Director at Cambridge University Press, first suggested the idea to us

A cognitive-motivational investigation of autobiographical memory

EThOS - Electronic Theses Online ServiceGBUnited Kingdo

Resmî vesâike müstenid büyük harb tarihi

Hindistan Hükumetinin Talebine Binaen İmparatorluk Müdafaa Heyeti'nin Tarih Şubesi'nin İdaresi Altında Olarak Liva Generali F. J. Moberly Tarafından Cem Ve Telfik Edilmişdir. Eserin Baş Tarafındaki İlave Sayfalar Ebced İle Numaralanmış Olup Eserin "Fihrist"İ, "Mehazlar" Listesi, "Mukaddime" Yazısı İle "Metin Dahilinde Telaffuzu Müşkil Olan İsm-İ Haslar" Tablosu Vardır. Eser Adı Başında, "Resmî Vesâike Müstenid Büyük Harb Tarihi". Eserde "Yüksek İktisat Ve Ticaret Mektebi Kütüphanesi" Mührü Vardır. Eserin İç Kapağında Matbaa (Askerî Matbaa) Amblemi Vardır

Biogeochemical cycling of toxic metals in Lake Coeur d'Alene sediments

Historic mining in the Coeur d'Alene area of Idaho has contaminated sediments, soils, and waters with heavy metals including, but not limited to, lead, copper, and zinc. Metal contamination continues to be introduced into Lake Coeur d'Alene and its tributaries by a variety of factors including seasonal changes, flooding, acid mine drainage, and air borne dust and this poses a significant health hazard to humans and biota. Bacteria residing in Lake Coeur d'Alene are capable of detoxifying metals using largely unknown processes. However, heavy metals exert toxic effects on the indigenous bacteria and these toxic effects highly depend on metal speciation, chemical properties, and geochemical factors. Therefore to develop an effective understanding of the metal toxicity in this environment and its effects on indigenous microorganisms, metal concentration, speciation, associated mineral phase, microbial toxicity, and microbial biogeochemical contributions to metal cycling must be studied. This work is broken up into five chapters. The first deals with the historic contamination, toxic metal transport, and microbial interactions with toxic metals, focused mainly on lead, copper, and zinc. Chapter two launches a more in depth look at the geochemistry of the Coeur d'Alene River Delta, both aqueous and sediment, using synchrotron based X-ray analyses to characterize the sediments. Chapter two also proposes some theoretical interactions between these identified mineral phases and microbes. The third chapter focuses on bacterial enrichments, isolation, and identification from the sediments using a novel flow reactor and batch culturing. The fourth chapter examines the toxic effects of zinc on Arthrobacter sp., an isolate from the novel reactor. This chapter includes a dual-Monod kinetic model to represent zinc inhibition of this organism. The model represents the experimental data very well at low metal concentrations and deviates at higher metal concentrations and this could be due to lag-components not included in the model or a variety of other reasons. Chapter five discusses some future work in biogeochemical metal cycling as it pertains to Coeur d'Alene

Resmi vesaika müstenit büyük harp tarihi : Irak seferi 1914-1918

Metin eski harfli Türkçedir

Seasonal and Basinal Influences on the Formation and Transport of Dissolved Trace Metal Forms in a Mining-Impacted Riverine Environment

The release of nanophase metal particles from sulfide mineral decomposition in mining-impacted environments is a growing concern because of the potential for the transport of nanoscale particles that could increase the distribution of the metals and their environmental impact. An analysis of total (unfiltered) and dissolved (450-nm filtered) metal concentrations in the mining-impacted Coeur d&rsquo;Alene River indicates the leaching of dissolved metal forms from sediments and transport to and within the river. The distribution of metals between total and dissolved forms is driven by seasonal temperatures, hydraulic gradients, and ligand availability. Cd and Zn were the least influenced by changes in gradient and biological productivity between the upper and lower basins. Cd and Zn primarily travel as dissolved forms, with the lowest ratio of dissolved-to-total concentrations in spring and the highest in summer. Fe and Pb primarily travel as suspended particles, but their dissolved forms were greater during all seasons in the lower basin. A principal components analysis of upper basin data indicates that temperature and conductivity were correlated with dissolved Cd and Zn, and total Fe and Pb were correlated with streamflow. In the lower basin, dissolved Cd and Zn, conductivity, and temperature were correlated, and suspended sediment, total metals, and dissolved Pb, but not streamflow, were correlated. The correlation of metals and sediment in the lower basin is not from erosion but the availability of organic matter and Fe that form a range of dissolved to suspended metal particles. The summer decrease in surface water levels releases sediment porewater containing nanoscale-to-microscale metal particles that are transported to open water, where they may impact human and wildlife health. Such releases are unmitigated with current remediation strategies of sediment stabilization