Glucose Degradation Research Articles

Responses of functional miRNA-mRNA regulatory modules to a high-fat diet in the liver of hybrid yellow catfish (Pelteobagrus fulvidraco × P. vachelli)

Fatty liver disease is common in cultured yellow catfish as a result of high fat contents in feeds. However, little is known about the mechanism by which the excessive deposition of liver fat causes fatty liver disease. Hybrid yellow catfish (Pelteobagrus fulvidraco♀ × P. vachelli♂) were fed a high-fat diet (HFD) or a normal-fat diet (NFD) for 60 days. Compared with the NFD group, the HFD group showed lower growth performance, higher hepatosomatic and viscerosomatic indexes, increased hepatic triglyceride and cholesterol contents, and more and larger lipid droplets in liver tissue. Whole transcriptome mRNA libraries and microRNA libraries from fish in the NFD and HFD groups were constructed by high-throughput sequencing. Twelve miRNAs were differentially expressed (DE) between the HFD and NFD groups. Seven negatively correlated DE miRNA–DE mRNA pairs were selected, and the expression patterns of both were confirmed using qRT-PCR. Hybrid yellow catfish showed mediated oxidative degradation of liver glucose and fatty acid peroxidation, regulation of antioxidant enzyme activity, and various immune and inflammatory responses to fat deposition and stress. These findings have important biological significance for protecting the liver against stress, as well as economic significance for establishing healthy aquaculture conditions.

Comparison of treatability of four different chlorophenol-containing wastewater by pyrite-Fenton process combined with aerobic biodegradation: Role of sludge acclimation

Aerobic biodegradation combined with pyrite-Fenton process was used for the treatment of wastewater containing different chlorophenols (4-CP, 2,3-DCP, 2,4-DCP, 2,4,6-TCP). Fenton degradation using pyrite as the low cost iron catalyst was used as a pre-treatment step to lower the toxicity of CPs prior to aerobic biodegradation. Synthetic wastewater spiked directly with either 100 mg/L CPs or pyrite-Fenton pre-treated CPs was fed to the batch bioreactors inoculated with unacclimated or acclimated activated sludge using glucose as the C-source. The results show that the CP biodegradation under aerobic conditions was highly dependent on the type of CP treated. Except for 2,4-DCP, all other CPs investigated caused severe sludge toxicity, and thus significantly hindered glucose degradation by unacclimated sludge. The CP toxicity decreased in the order of: 2,4,6-TCP > 2,3-DCP > 4-CP > 2,4-DCP. The toxic effect was explained through an interaction of CPs with the lipid fraction of cell membrane. While the pyrite-Fenton pre-treatment improved the COD removal efficiency using unacclimated sludge, the sCOD removal efficiency was still less than the control reactor operated with no CP addition. With sludge acclimation, however, the sCOD removal efficiencies increased, and approached 74% for 2,4-DCP, 61% for 4-CP, 56% for 2,4,6-TCP and 46% for 2,3-DCP, suggesting an enhanced biomass tolerance to CP toxicity. On the other hand, the sludge acclimation combined with pyrite Fenton pre-treatment provided the best bioreactor performance for all CPs with the sCOD removal efficiencies reaching 81% for 2,4,6-TCP, 78% for 2,4-DCP, 73% for 4-CP and 62% for 2,3-DCP. This suggests that the dechlorination of CPs with Fenton process, in conjunction with sludge acclimation, not only reduced the sludge toxicity, but also enhanced the bioavailability of CP-containing wastewater for microorganisms, especially for highly chlorinated toxic CPs such as 2,4,6-TCP. Overall, the findings highlight the need for sludge acclimation for effective treatment of chlorophenol-containing wastewater by a combined pyrite-Fenton and aerobic biodegradation system.

Metal cations promote \u03b1-dicarbonyl formation in glucose-containing peritoneal dialysis fluids

Heat sterilization of peritoneal dialysis fluids (PDFs) leads to the formation of glucose degradation products (GDPs), which impair long-term peritoneal dialysis. The current study investigated the effects of metal ions, which occur as trace impurities in the fluids, on the formation of six major α-dicarbonyl GDPs, namely glucosone, glyoxal, methylglyoxal, 3-deoxyglucosone, 3-deoxygalactosone, and 3,4-dideoxyglucosone-3-ene. The chelation of metal ions by 2-[bis[2-[bis(carboxymethyl)amino]ethyl]amino]acetic acid (DTPA) during sterilization significantly decreased the total GDP content (585 μM vs. 672 μM), mainly due to the decrease of the glucose-oxidation products glucosone (14 μM vs. 61 μM) and glyoxal (3 μM vs. 11 μM), but also of methylglyoxal (14 μM vs. 31 μM). The glucose-dehydration products 3-deoxyglucosone, 3-deoxygalactosone, and 3,4-dideoxyglucosone-3-ene were not significantly affected by chelation of metal ions. Additionally, PDFs were spiked with eleven different metal ions, which were detected as traces in commercial PDFs, to investigate their influence on GDP formation during heat sterilization. Iron(II), manganese(II), and chromium(III) had the highest impact increasing the formation of glucosone (1.2–1.5 fold increase) and glyoxal (1.3–1.5 fold increase). Nickel(II) and vanadium(III) further promoted the formation of glyoxal (1.3 fold increase). The increase of the pH value of the PDFs from pH 5.5 to a physiological pH of 7.5 resulted in a decreased formation of total GDPs (672 μM vs 637 μM). These results indicate that the adjustment of metal ions and the pH value may be a strategy to further decrease the content of GDPs in PDFs.

Profiling changes in primary metabolites and antioxidants during apple fruit decay caused by Penicillium crustosum

Penicillium crustosum is one of the causal agents of apple fruit blue mold decay. It produces mycotoxins and it is widely distributed, although a less aggressive pathogen than P. expansum. Changes in sugars (sucrose, glucose, and fructose), organic acids (malic and shikimic), and antioxidants (total glutathione, ascorbate, and phenolics) were monitored in P. crustosum infected apples at 6 and 24 hpi, 3, 5, 7, and 11 dpi. The initial stage of infection (6 hpi) was characterized by a decline in fructose, malic acid, and total phenolic contents, whereas the total glutathione considerably increased. Twenty-four hpi and 3 dpi the strong activation of ascorbate-glutathione cycle correlated significantly with total phenolics and organic acid enhancement at the expense of sugars. At 5 dpi the progress of visible symptoms caused a temporary breakdown of apple defense, leading to degradation of total phenolics, glutathione, and glucose, whereas the fructose as a crucial signal molecule increased significantly. An acclimation of the defense system was achieved at 7 dpi by accumulating fructose, sucrose and antioxidants that further resulted in stable ratio of most of the investigated metabolites at 11 dpi. LDA analysis enabled us to define the fructose, glucose, malic acid and ascorbate-glutathione cycle as crucial temporary marker with balanced cross-induction playing a complex role in apple defense against P. crustosum. In summary, apple fruit reacted on P. crustosum by activating defense mechanisms quickly after inoculation (6 hpi), and stayed at the higher level until 5 dpi when temporary breakdown occurred. Apple fruit managed to recover as metabolites were fairly in balance after 11 dpi. Phenolics were viewed as a wheel of the apple fruit defense mechanism, driven by the ascorbate–glutathione system, while glutathione and fructose are believed to have had a crutial role in signaling.

Profiling of glucose degradation products through complexation with divalent metal ions coupled with ESI/qTOF/MS/MS analysis

Sugar degradation products generated through thermal treatment of foods are considered the key precursors for various flavor compounds, toxicants and browning, but their high reactivity makes their detection difficult. In this study, a convenient analytical procedure for profiling of various reactive sugar intermediates having enediol or α-dicarbonyl moieties through complexation with divalent metal ions combined with electrospray ionization/quadrupole time-of-flight mass spectrometry was developed. Excess divalent iron chloride (FeCl2) was added to glucose or 13U6-[glucose] solutions in methanol either before or after heating at 110 °C for 2 h, and the samples were analyzed by tandem mass spectrometry. The results indicated the formation of ethylene glycol, glycolaldehyde, glyceraldehyde, glycerol, methylglyoxal, glyoxylic acid, erythrose, erythrosone, 3-deoxy-erythrosone, erythritol, ribose, ribosone, 3-deoxy-ribose, ribitol, 3-deoxy-glucosone, and rhamnose. These sugars and sugar degradation products acting as bidentate ligands were detected as positively charged mono- and bis-sugar iron complexes in the form of [M + H]+, [M + Na]+, [M + K]+, [M + Fe35Cl]+, and [M + Fe37Cl]+, as well as by charge localization on iron [M]+. The divalent metal complexation technique was applied for the profiling of sugar degradation products in aged manuka honey.

Influence of dialysate temperature on creatinine peritoneal clearance in peritoneal dialysis patients: a randomized trial

BackgroundPatients on continuous ambulatory peritoneal dialysis (PD) are encouraged to warm dialysate to 37 °C before peritoneal infusion; main international PD guidelines do not provide specific recommendation, and patients generally warm dialysate batches partially or do not warm them at all. Warming of dialysate is a time-consuming procedure, not free from potential risks (i.e. degradation of glucose), and should be justified by a clear clinical benefit.MethodsWe designed a single blind randomized controlled trial where 18 stable PD patients were randomized to receive a peritoneal equilibration test either with dialysate at a controlled temperature of 37 °C (intervention group) or with dialysate warmed with conventional methods (control group). Primary end-point was a higher peritoneal creatinine clearance in patients in the intervention group.ResultsPatients in the intervention group did not show a significantly higher peritoneal creatinine clearance when compared to the control group (6.38 ± 0.52 ml/min vs 5.65 ± 0.37 ml/min, p = 0.2682). Similar results were obtained for urea peritoneal clearance, mass transfer area coefficient of creatinine and urea. There were no significant differences in total abdominal discomfort questionnaire score, blood pressure and body temperature between the two groups.ConclusionsUsing peritoneal dialysate at different temperatures without causing significant side effects to patients appears feasible. We report a lack of benefit of warming peritoneal dialysate to 37 °C on peritoneal clearances; future PD guidelines should not reinforce this recommendation.Trial registrationNCT04302649, ClinicalTrials.gov; date of registration 10/3/2020 (retrospectively registered).

Kinetics Study of Acid Catalyzed Degradation of Glucose in High-Temperature Liquid Water

Glucose is the most abundant monosaccharide in nature, glucose obtained from cellulose and starch, it is many used to degradation process, and for the production of several organic compounds, one of the degradation products of glucose is an HMF (5-hydroxymethylfurfural). HMF is a platform chemical, which can be converted into several chemical and liquid fuels through hydrogenation, oxidation, and esterification. The objective of this researches has studied the kinetics of glucose degradation using acid-catalyzed (H2SO4) in high-temperature liquid water and observe the effect of acid concentration and temperature on degradation of glucose to HMF. In this research was used reactor with pressure 10 atm, with variation time of reaction, sulfuric acid concentration, and temperature of the reaction. From this research found kinetics of glucose degradation was followed by the first-order reaction in each variable. Activation Energy (Ea) values were 7306,593 J/mol; 6341,59 J/mol; 3988,14 J/mol and 3988,14 J/mol on the concentration sulfuric acid 0,05M; 0,1 M; 0,05M, from that result indicated that reaction rate was increase when activation energy was decrease this was related to Arrhenius equation. The effect of acid concentration on degradation glucose was the higher acid concentration used, the more glucose was degraded, and more HMF was formed. Meanwhile, the effect of temperature of reaction on degradation glucose was the higher temperature of the reaction, more glucose was degraded, and more HMF was formed. The highest value of HMF was in operation condition of concentration H2SO4 0,5 M at 175°C, with a time of reaction 120 minutes. However, the reduction rate of glucose was not equal to the rate of formation of HMF (5-hydroxymethylfurfural), it can be indicated that HMF (5-hydroxymethylfurfural) was not the only product of degradation of glucose, but the others product might be formed from this operating condition. The other product that might be formed was humin and levulinic acid.

Increased miR-7641 Levels in Peritoneal Hyalinizing Vasculopathy in Long-Term Peritoneal Dialysis Patients.

Peritoneal hyalinizing vasculopathy (PHV) represents the cornerstone of long-term peritoneal dialysis (PD), and especially characterizes patients associated with encapsulating peritoneal sclerosis. However, the mechanisms of PHV development remain unknown. A cross sectional study was performed in 100 non-selected peritoneal biopsies of PD patients. Clinical data were collected and lesions were evaluated by immunohistochemistry. In selected biopsies a microRNA (miRNA)-sequencing analysis was performed. Only fifteen patients (15%) showed PHV at different degrees. PHV prevalence was significantly lower among patients using PD fluids containing low glucose degradation products (GDP) (5.9% vs. 24.5%), angiotensin converting enzyme inhibitors (ACEIs) (7.5% vs. 23.4%), statins (6.5% vs. 22.6%) or presenting residual renal function, suggesting the existence of several PHV protective factors. Peritoneal biopsies from PHV samples showed loss of endothelial markers and induction of mesenchymal proteins, associated with collagen IV accumulation and wide reduplication of the basement membrane. Moreover, co-expression of endothelial and mesenchymal markers, as well as TGF-β1/Smad3 signaling activation were found in PHV biopsies. These findings suggest that an endothelial-to-mesenchymal transition (EndMT) process was taking place. Additionally, significantly higher levels of miR-7641 were observed in severe PHV compared to non-PHV peritoneal biopsies. Peritoneal damage by GDPs induce miRNA deregulation and an EndMT process in submesothelial vessels, which could contribute to collagen IV accumulation and PHV.

Alanyl-Glutamine Restores Tight Junction Organization after Disruption by a Conventional Peritoneal Dialysis Fluid.

Understanding and targeting the molecular basis of peritoneal solute and protein transport is essential to improve peritoneal dialysis (PD) efficacy and patient outcome. Supplementation of PD fluids (PDF) with alanyl-glutamine (AlaGln) increased small solute transport and reduced peritoneal protein loss in a recent clinical trial. Transepithelial resistance and 10 kDa and 70 kDa dextran transport were measured in primary human endothelial cells (HUVEC) exposed to conventional acidic, glucose degradation products (GDP) containing PDF (CPDF) and to low GDP containing PDF (LPDF) with and without AlaGln. Zonula occludens-1 (ZO-1) and claudin-5 were quantified by Western blot and immunofluorescence and in mice exposed to saline and CPDF for 7 weeks by digital imaging analyses. Spatial clustering of ZO-1 molecules was assessed by single molecule localization microscopy. AlaGln increased transepithelial resistance, and in CPDF exposed HUVEC decreased dextran transport rates and preserved claudin-5 and ZO-1 abundance. Endothelial clustering of membrane bound ZO-1 was higher in CPDF supplemented with AlaGln. In mice, arteriolar endothelial claudin-5 was reduced in CPDF, but restored with AlaGln, while mesothelial claudin-5 abundance was unchanged. AlaGln supplementation seals the peritoneal endothelial barrier, and when supplemented to conventional PD fluid increases claudin-5 and ZO-1 abundance and clustering of ZO-1 in the endothelial cell membrane.

Flux balance analysis of glucose degradation by anaerobic digestion in negative pressure

Flux balance analysis (FBA) has been widely used for detecting internal fluxes of bacteria. In this study, FBA was applied to estimate metabolic phenotype in glucose fermentation under negative pressure. Result revealed that ethanol, propionic acid, and butyric acid were converted to acetate by lowering headspace pressure (HP) of fermenter with the conversion rate of 0.091, 0.014, and 0.017 mol-acetate/mol-glucose respectively In addition, these three substances were simultaneously converted into H2 with the conversion rate of 0.258 mol-H2/mol-glucose. A total of 30% acetate and 26% H2 production increase were observed under condition of 0.6 atm HP fermentation. Furthermore, 30% accumulated hydrogen was consumed in the formation of propanol and valeric acid.

Mechanisms underlying the predictive power of high skeletal muscle uptake of FDG in amyotrophic lateral sclerosis

BackgroundWe recently reported that enhanced [18F]-fluorodeoxyglucose (FDG) uptake in skeletal muscles predicts disease aggressiveness in patients with amyotrophic lateral sclerosis (ALS). The present experimental study aimed to assess whether this predictive potential reflects the link between FDG uptake and redox stress that has been previously reported in different tissues and disease models.MethodsThe study included 15 SOD1G93A mice (as experimental ALS model) and 15 wildtype mice (around 120 days old). Mice were submitted to micro-PET imaging. Enzymatic pathways and response to oxidative stress were evaluated in harvested quadriceps and hearts by biochemical, immunohistochemical, and immunofluorescence analysis. Colocalization between the endoplasmic reticulum (ER) and the fluorescent FDG analog 2-[N-(7-nitrobenz-2-oxa-1,3-diazol-4-yl)amino]-2-deoxyglucose (2-NBDG) was performed in fresh skeletal muscle sections. Finally, mitochondrial ultrastructure and bioenergetics were evaluated in harvested quadriceps and hearts.ResultsFDG retention was significantly higher in hindlimb skeletal muscles of symptomatic SOD1G93A mice with respect to control ones. This difference was not explained by any acceleration in glucose degradation through glycolysis or cytosolic pentose phosphate pathway (PPP). Similarly, it was independent of inflammatory infiltration. Rather, the high FDG retention in SOD1G93A skeletal muscle was associated with an accelerated generation of reactive oxygen species. This redox stress selectively involved the ER and the local PPP triggered by hexose-6P-dehydrogenase. ER involvement was confirmed by the colocalization of the 2-NBDG with a vital ER tracker. The oxidative damage in transgenic skeletal muscle was associated with a severe impairment in the crosstalk between ER and mitochondria combined with alterations in mitochondrial ultrastructure and fusion/fission balance. The expected respiratory damage was confirmed by a deceleration in ATP synthesis and oxygen consumption rate. These same abnormalities were represented to a markedly lower degree in the myocardium, as a sample of non-voluntary striated muscle.ConclusionSkeletal muscle of SOD1G93A mice reproduces the increased FDG uptake observed in ALS patients. This finding reflects the selective activation of the ER-PPP in response to significant redox stress associated with alterations of mitochondrial ultrastructure, networking, and connection with the ER itself. This scenario is less severe in cardiomyocytes suggesting a relevant role for either communication with synaptic plaque or contraction dynamics.

Effect of ammonia on anaerobic digestion of municipal solid waste: Inhibitory performance, bioaugmentation and microbiome functional reconstruction

The bioaugmentation is crucial to improve the energy-efficient process for anaerobic digestion of organic wastes at high ammonia levels. Genomic insights into the intricate microbial networks at a high ammonia level remain underexplored. The present study showed that the addition of Methanoculleus sp. DTU887 remarkably enhanced the methane production yield of organic fraction of municipal solid waste by 21% and decreased the volatile fatty acids by 10% when compared to the period before bioaugmentation. Genome-centric metagenomics reports the functional contribution of microbial members during organic waste degradation under the extremely high level of 13.5 g NH4+-N/L. Specifically, metabolic reconstruction revealed that these organisms have the potential to perform fermentative and acetogenic catabolism, a process facilitated by energy conservation-related with H2/CO2 metabolism. Peptococcaceae spp. (DTU903, DTU900, and DTU895). and Tissierellales sp. DTU879 could degrade the organic waste hydrolysis product, i.e., glucose to acetate and H2. Tissierellales sp. DTU879 and Syntrophaceticus sp. DTU783 could degrade the derived acetate. The H2 scavenging Methanoculleus sp. DTU887 performs complementary metabolic reactions with Peptococcaceae spp., Tissierellales sp. and Syntrophaceticus sp., indicating syntrophic glucose and acetate degradation. This research offers the first insight that the key organisms form a syntrophy-supported food web in response to the bioaugmentation with ammonia tolerant methanogens performed in an AD system subjected to severe ammonia inhibition.

Biotransformation of Carboxylic Acids to Alcohols: Characterization of Thermoanaerobacter Strain AK152 and 1-Propanol Production via Propionate Reduction.

Thermoanaerobacter strains have recently gained interest because of their ability to convert short chain fatty acids to alcohols using actively growing cells. Thermoanaerobacter thermohydrosulfuricus strain AK152 was physiologically investigated for its ethanol and other alcohol formation. The temperature and pH optimum of the strain was 70 °C and pH 7.0 and the strain degraded a variety of compounds present in lignocellulosic biomass like monosaccharides, disaccharides, and starch. The strain is highly ethanologenic, producing up to 86% of the theoretical ethanol yield form hexoses. Strain AK152 was inhibited by relatively low initial substrate (30 mM) concentration, leading to inefficient degradation of glucose and levelling up of all end-product formation. The present study shows that the strain produces alcohols from most of the tested carboxylic acids, with the highest yields for propionate conversion to propanol (40.7%) with kinetic studies demonstrating that the maximum conversion happens within the first 48 h of fermentation. Various physiological tests were performed to maximize the acid conversion to the alcohol which reveals that the optimum pH for propionate conversion is pH 6.7 which affords a 57.3% conversion. Kinetic studies reveal that propionate conversion is rapid, achieving a maximum conversion within the first 48 h of fermentation. Finally, by using 13C NMR, it was shown that the addition of propionate indeed converted to propanol.

Comparison of glucose degradation product and receptor levels in dıabetic and normal pregnancy

The aim of this study was to assess the diagnostic values of new biochemical markers that may be an alternative to the oral glucose tolerance test (OGTT) and determine the differences in these markers among three groups of women with varying degrees of glucose homeostasis dysregulation. This was a prospective study. All women were screened with 50 gram (g) oral glucose and a 100 g OGTT for gestational diabetes mellitus (GDM). The patients were divided into three groups depending on the result of the tests: no evidence of glucose metabolism abnormality (controls); impaired glucose tolerance (IGT); and GDM. All three groups were evaluated for serum human advanced glycation end-products (AGEs) concentrations, carboxymethyl lysine (CML) concentration and receptor for advanced glycation end-product concentrations (RAGE/AGER), body mass index (BMI), age, fasting glucose levels, obstetrical parameters and gestational age. The study included 180 women divided into 59 (32.8%) GDM, 50 (27.8%) IGT and 71 (39.4%) controls. Age was similar among the three groups. Whereas fasting glucose levels and BMI in the three groups was significantly different, AGEs, CML, RAGE/AGER levels were found as significantly different between the groups (p<0.001). In this study the use of AGEs, CML, and RAGE/AGER concentrations for the diagnosis and screening of gestational diabetes was investigated. It was found that advanced glycation products were significantly elevated in pregnancies with both IGT and GDM. These biochemical markers of glucose homeostasis dysregulation may have potential for GDM screening in the future.

P1166DOES PERITONEAL PROTEIN LOSS AFFECT CARDIOVASCULAR MORTALITY OF PERITONEAL DIALYSIS PATIENTS ?

Abstract Background and Aims Peritoneal protein loss (PPL) through peritoneal effluent has been a well-recognized detrimental result of peritoneal dialysis (PD). The amount of protein lost will depend on dialysis time, protein size, its serum concentration and other factors including patients’ clinical status. Peritoneal protein loss may be a manifestation of endothelial dysfunction, as with another type of capillary protein leakage, microalbuminuria, a recognized endothelial dysfunction marker. The aim of this study was to retrospectively evaluate the influence of PPL on cardiovascular mortality of peritoneal dialysis patients Method This is a single center retrospective study of 84 PD patients (m=54, f=30) with mean age of 65.2±17 years, mean PD duration of 43.2±24.9 months conducted for the time period from 2006 to 2019 (13 years). The patients were divided into two groups according to the amount of protein excreted during the modified Peritoneal Equilibration Test (PET) procedure using PD solution of 3.86% DW, 2 Lt infusion volume for total time of 4 hours. The total amount of proteins excreted was calculate from PET by multiplying the concentration of proteins at the end of the test with the total volume of PD fluid at the same time. Group A excreted a total amount of proteins &amp;lt; 1.55 gr (median value) at the end of PET test and Group B &amp;gt; 1.55 gr. The cumulative all-cause and cardiovascular survival of the PD patients was calculated by Kaplan Meier while the possible effect of any parameter in survival rates was evaluated by using Cox Regression analysis Results There was not any statistically significant difference between the two groups according to PD duration, age, dialysis adequacy targets, Residual Renal Function(RRF), BMI, ultrafiltration volume during PET and their transport status. The cumulative all-cause survival using Kaplan-Meier analysis revealed no statistically significant deference between the two groups (Log Rank p=0.55) even though mortality risk was adjusted for several factors (Cox Regression). When cardiovascular survival, using Cox Regression analysis, was adjusted for age, sex, Diabetes, PD modality, dialysis Kt/V and RRF we found that Group A (with protein excretion &amp;lt; 1.55 gr) had statistically significant better cardiovascular survival (p=0.029) compared to Group B. We confirm these results while trying to find among the total of our patients the possible risk factors for cardiovascular mortality. Using Cox Regression analysis, the amount of protein excreted during PET procedure and the type of PD solutions (high or low in GDPs) used were statistically significant (p=0.019 and p=0.04 respectively) independent risk factors for cardiovascular survival in our patients. Conclusion These results indicate that protein loss during peritoneal dialysis procedure has negative impact on cardiovascular mortality and survival of PD patients. Additionally, the use of PD solutions with low Glucose Degradation Products (GDPs) and AGEs may improve PD patient’s cardiovascular survival. Randomized interventional studies are encouraged to address the pathological concern of PPL in the future, namely its effects on cardiovascular conditions or its role as marker and effort to reduce PPL using ACE inhibitors or vit D should be considered only if it diminishes cardiovascular morbidity or mortality.

P1190OXIDATIVE STRESS AND INFLAMMATION IN PERITONEAL DIALYSIS: DANGEROUS AND TO BE SOLVED

Abstract Background and Aims Cardiovascular disease is the leading cause of excess mortality in chronic kidney disease (CKD) and dialysis patients with oxidative stress (OxSt) and inflammation playing a pivotal role, as non-traditional risk factors and OxSt and inflammation have been shown to increase in peritoneal dialysis. Rho kinase (ROCK) activation is deeply involved in the induction of OxSt and inflammation and is closely linked to cardiovascular-renal remodeling. We aimed to evaluate in peritoneal dialysis patients with a molecular biology approach OxSt, in terms of phosphorylation state of MYPT-1 (marker of ROCK activity), the protein expression of p22phox (subunit of NADPH oxidase, essential for the generation of ROS), and inflammation state, in terms of acute-phase proteins level (Interleukin 6 (IL-6), ultra-sensitive C-reactive protein (US-CRP), Ferritin, Albumin and Transferrin). Method 9 male ESRD patients (39-81 years old) were enrolled and analyzed before (baseline) and after three and six months of peritoneal dialysis treatment (CAPD 7 patients, APD 2 patients). Mononuclear cells (PBMCs) MYPT-1 phosphorylation state and p22phox protein expression were determined by Western Blot. Specific acute-phase proteins as IL-6, US-CRP, Ferritin, Albumin and Transferrin were assessed through blood chemistry tests. Results MYPT-1 phosphorylation was increased after six months of treatment with peritoneal dialysis compared with three months and predialysis (1.03±0.07 vs 1.02±0.04 vs 1.57±0.16 d.u., p&amp;lt;0.0001). p22phox protein expression (0.72±0.05 vs 0.73±0.10 vs 1.28±0.12 d.u., p&amp;lt;0.0001) and ferritin level (101.4±15.3 vs 173.6±11.5 vs 189.0±20.3 µg/l, p=0.002) increased as well. Albumin was decreased after six months of peritoneal dialysis treatment compared with three months and predialysis (43.38±0.10 vs 40.00±1.59 vs 36.46±1.43 g/l, p=0.007). IL-6 and US-CRP remained unchanged at a high level. Conclusion The increase of OxSt and inflammation during peritoneal dialysis is confirmed also at molecular biology level and may lead in the medium-long term to dangerous consequences. The necessary improvement of OxSt status in peritoneal dialysis needs a multitarget approach. It might include the use of neutral pH, low glucose degradation products, low lactate and iso-osmolar peritoneal dialysis solutions, strict glycemic control, optimal volume management and, likely, a supplementation with antioxidants as N-acetylcysteine.

Instability of Insulin Aspart Diluted in Dextrose

Insulin aspart (Novorapid) is a rapid-acting insulin analog that is maintained in hexameric form by phenolic preservatives (phenol and metacresol) and stabilized by insulin-zinc complex. According to the manufacturers, insulin can be independently diluted either in 5% dextrose solution (D5%) or 0.9% sodium chloride solution. In reality, in most clinical units, such as the neonatal intensive care unit (NICU), insulin aspart is more frequently diluted in D5% than in saline solution due to sodium restriction. However, injectable dextrose solutions contain glucose degradation products (1) that are capable of binding proteins—like insulin—through a glycation phenomenon. Therefore, dilution of Novorapid in D5% would be more likely to cause glycated insulin and may raise a worrisome problem in terms of insulin stability. The objective of this study was to investigate the stability of insulin aspart diluted in D5% at both adult and neonate therapeutic concentrations in order to ensure its appropriateness in the preparation of insulin aspart. To address this issue, insulin aspart diluted in D5% was assayed by a stability-indicating method using high-performance liquid chromatography (HPLC) coupled with an ultraviolet (UV) detector. The nature of the formed product was determined by HPLC coupled with a mass spectrometer. The effect of …

Longitudinal Changes of NF-\u03baB Downstream Mediators and Peritoneal Transport Characteristics in Incident Peritoneal Dialysis Patients

The role of intra-peritoneal mediators in the regulation peritoneal transport is not completely understood. We investigate the relation between longitudinal changes in dialysis effluent level of nuclear factor kappa-B (NF-κB) downstream mediators and the change in peritoneal transport over 1 year. We studied 46 incident PD patients. Their peritoneal transport characteristics were determined after starting PD and then one year later. Concomitant dialysis effluent levels of interleukin-6 (IL-6), cyclo-oxygenase-2 (COX-2) and hepatocyte growth factor (HGF) are determined. There were significant correlations between baseline and one-year dialysis effluent IL-6 and COX-2 levels with the corresponding dialysate-to-plasma creatinine level at 4 hours (D/P4) and mass transfer area coefficient of creatinine (MTAC). After one year, patients who had peritonitis had higher dialysis effluent IL-6 (26.6 ± 17.4 vs 15.1 ± 12.3 pg/ml, p = 0.037) and COX-2 levels (4.97 ± 6.25 vs 1.60 ± 1.53 ng/ml, p = 0.007) than those without peritonitis, and the number of peritonitis episode significantly correlated with the IL-6 and COX-2 levels after one year. In contrast, dialysis effluent HGF level did not correlate with peritoneal transport. There was no difference in any mediator level between patients receiving conventional and low glucose degradation product solutions. Dialysis effluent IL-6 and COX-2 levels correlate with the concomitant D/P4 and MTAC of creatinine. IL-6 and COX-2 may contribute to the short-term regulation of peritoneal transport.

Encapsulating Peritoneal Sclerosis (EPS): Analysis of Current Knowledge in the Literature and Observation of a Suspect Case

Among the medical complications of long-lasting Peritoneal Dialysis (PD) a particular pathology has been observed, the so-called Encapsulating Peritoneal Sclerosis (EPS). The main properties of the pathological process of EPS is represented by proliferative fibrosis and sclerosis of the peritoneum, which lead to the formation of the typical "cocoon" and obstruction. Since glucose, Advanced Glycation End products (AGEs), and Glucose Degradation Products (GDPs), are responsible for peritoneum fibrosis and sclerosis, biocompatible peritoneal dialysis solutions are recommended, with reduced quantities of AGEs and GDPs. Furthermore, careful monitoring of the patients is very important, especially after 5-8 years of PD. We performed an overview of the current literature available and discuss a “suspect” case of a 59-year-old male patient who underwent a single kidney transplant after a period of 8 year of peritoneal dialysis with numerous sub occlusive episodes, some of them required hospitalizations in a period between 2011 and 2019. Patient underwent to several radiologic exams for a suspect of a cocoon syndrome.

The effect of anode potential on current production from complex substrates in bioelectrochemical systems: a case study with glucose

Anode potential can affect the degradation pathway of complex substrates in bioelectrochemical systems (BESs), thereby influencing current production and coulombic efficiency. However, the intricacies behind this interplay are poorly understood. This study used glucose as a model substrate to comprehensively investigate the effect of different anode potentials (− 150 mV, 0 mV and + 200 mV) on the relationship between current production, the electrogenic pathway and the abundance of the electrogenic microorganisms involved in batch mode fed BESs. Current production in glucose-acclimatized reactors was a function of the abundance of Geobacteraceae and of the availability of acetate and formate produced by glucose degradation. Current production was increased by high anode potentials during acclimation (0 mV and + 200 mV), likely due to more Geobacteraceae developing. However, this effect was much weaker than a stimulus from an artificial high acetate supply: acetate was the rate-limiting intermediate in these systems. The supply of acetate could not be influenced by anode potential; altering the flow regime, batch time and management of the upstream fermentation processes may be a greater engineering tool in BES. However, these findings suggest that if high current production is the focus, it will be extremely difficult to achieve success with complex waste streams such as domestic wastewater.