14 research outputs found
Vitamin e-loaded membrane dialyzers reduce hemodialysis inflammaging
No full textBackground: Inflammaging is a persistent, low-grade, sterile, nonresolving inflammatory state, associated with the senescence of the immune system. Such condition downregulates both innate and adaptive immune responses during chronic disorders as type II diabetes, cancer and hemodialysis, accounting for their susceptibility to infections, malignancy and resistance to vaccination. Aim of this study was to investigate hemodialysis inflammaging, by evaluating changes of several hemodialysis treatments on indoleamine 2,3-dioxygenase-1 activity and nitric oxide formation. Methods: We conducted a randomized controlled observational crossover trial. Eighteen hemodialysis patients were treated with 3 different hemodialysis procedures respectively: 1) Low-flux bicarbonate hemodialysis, 2) Low-flux bicarbonate hemodialysis with vitamin E-loaded dialyzers, and 3) Hemodialfitration. The control group consisted of 14 hospital staff healthy volunteers. Blood samples were collected from all 18 hemodialysis patients just after the long interdialytic interval, at the end of each hemodialysis treatment period. Results: Hemodialysis kynurenine and kynurenine/L-tryptophan blood ratio levels were significantly higher, when compared to the control group, indicating an increased indoleamine 2,3-dioxygenase-1 activity in hemodialysis patients. At the end of the low-flux bicarbonate hemodialysis with vitamin E-loaded dialyzers period, L-tryptophan serum levels remained unchanged vs both low-flux bicarbonate hemodialysis and hemodialfitration. Kynurenine levels instead decreased, resulting in a significant reduction of kynurenine/L-tryptophan blood ratio and indoleamine 2,3-dioxygenase-1 activity, when matched to both low-flux bicarbonate hemodialysis and HDF respectively. Serum nitric oxide control group levels, were significantly lower when compared to all hemodialysis patient groups. Interestingly, low-flux bicarbonate hemodialysis with vitamin E-loaded dialyzers nitric oxide serum levels from venous line blood samples taken 60 min after starting the hemodialysis session were significantly lower vs serum taken simultaneously from the arterial blood line. Conclusions: The treatment with more biocompatible hemodialysis procedure as low-flux bicarbonate hemodialysis with vitamin E-loaded dialyzers, reduced indoleamine 2,3-dioxygenase-1 activity and nitric oxide formation when compared to both low-flux bicarbonate hemodialysis and hemodialfitration. These data suggest that low-flux bicarbonate hemodialysis with vitamin E-loaded dialyzers lowering hemodialysis inflammaging, could be associated to changes of proinflammatory signalling a regulated molecular level. Trial registration: NCT Number: NCT02981992; Other Study ID Numbers: 20100014090. First submitted: November 26, 2016. First posted: December 5, 2016. Last Update Posted: December 5, 2016
LC-MS/MS assay for the simultaneous determination of tocopherols, polyunsaturated fatty acids and their metabolites in human plasma and serum
No full textThe role of vitamin E in both enzymatic and free radical-dependent metabolism of polyunsaturated fatty acids (PUFAs) has been well demonstrated. This study proposed a new LC-MS/MS method to quantify the main vitamin E forms, their metabolites and main PUFA species in human blood, since, at present, there are not procedures able to simultaneously determine these two classes of compounds. After the optimization of sample treatment and reverse-phase separation conditions, tandem mass spectrometry detection was evaluated experimenting both positive and negative electrospray ionisation modes. The procedure was also preliminarily adapted to assess five arachidonic acid-derived eicosanoids that could be under the influence of vitamin E function, such as LTB4 (leukotriene B4), 20-HETE (20-hydroxyeicosatetraenoic acid) and their ω-oxidation metabolites. After the validation study, the performance characteristics were confirmed analysing a certified reference material (SRM® 1950 - frozen human plasma by NIST). Finally, an application of the method in the analysis of lipid abnormalities of chronic kidney disease patients was shown
RBP4: A Culprit for Insulin Resistance in End Stage Renal Disease That Can Be Cleared by Hemodiafiltration
No full textIntroduction. Retinol Binding Protein 4 (RBP4) is mainly excreted by the kidney and plays a pivotal role in insulin resistance (IR). In our study, we evaluated the association between RBP4 and IR in hemodialysis subjects (HD). We also assessed how circulating RBP4 could be influenced by kidney transplant or different dialytic techniques.Methods. RBP4 serum levels were evaluated in HD (n=16) and matched healthy controls (C;n=16). RBP4 and glucose transporter type 4 (GLUT4) mRNA expressions were also determined in adipose tissue. Circulating RBP4 was evaluated after kidney transplant (n=7) and in hemodialysis patients (n=10) enrolled in a cross-over study treated with standard bicarbonate dialysis (BD) or hemodiafiltration (HDF).Results. HOMA index (P<0.05) and serum RBP4 (P<0.005) were higher in HD compared to C. RBP4 levels positively correlated with fasting serum glucose (P<0.05). RBP4 mRNA was lower in HD compared to C (P<0.05) and positively correlated with kidney function (P<0.05) and GLUT4 mRNA (P<0.001). Transplant or HDF reduced circulating RBP4 (P<0.01andP<0.05, resp.). Our results demonstrate that IR is associated with high circulating RBP4 and that suppressed RBP4 adipose tissue expression is accompanied by reduced GLUT4 expression in HD. Renal transplantation or HDF are effective in lowering serum RBP4 levels.</jats:p
Antineutrophil Cytoplasmic Antibody-Associated Renal Vasculitis Treated With Autologous Mesenchymal Stromal Cells: Evaluation of the Contribution of Immune-Mediated Mechanisms.
No full textWe report the first case of renal antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis treated with autologous mesenchymal stromal cells (MSCs). A 73-year-old man was admitted to the hospital for malaise, weight loss, and oliguria. His serum creatinine level was 2.7 mg/dL but it rapidly increased to 7.8 mg/dL; urinalysis showed proteinuria and hematuria, and the ANCA to myeloperoxidase with a perinuclear pattern (pANCA) titer was high (132 IU/mL). Renal biopsy showed necrotizing crescentic glomerulonephritis. Standard immunosuppressive therapy (cyclophosphamide and corticosteroids) was ineffective. Rituximab therapy was started, but it was discontinued after the third dose to minimize the risk of systemic spread of a severe oral Candida infection and to prevent superinfections that were facilitated by leukopenia. The patient received autologous MSCs, 1.5 × 106 cells/kg body weight, intravenously. After 7 days, his serum creatinine level decreased to 2.2 mg/dL, pANCA titer decreased to 75 IU/mL, and urinalysis findings normalized. Eight months later, he received a second MSC infusion because his serum creatinine level increased. In 1 week, his creatinine level decreased to 1.9 mg/dL and his pANCA titer decreased to 14 IU/mL. Immunosuppressive therapy was subsequently withdrawn. At the last follow-up visit, 12 months after the second MSC infusion, the patient remained in clinical remission without any therapy. Infusion of MSCs induced expansion of the T-lymphocyte subset expressing a regulatory T-cell phenotype (CD4+CD25+Foxp3+) and a notable reduction in interferon-γ, interleukin 6, and tumor necrosis factor serum levels
Determination of tocopherols and their metabolites by liquid-chromatography coupled with tandem mass spectrometry in human plasma and serum
No full textSeveral studies are increasingly underlying the biological role of vitamin E metabolites as bioactive compounds with anti-inflammatory, anti-proliferative and anti-atherogenic activity. A quantitative method for the simultaneous determination in human plasma and serum of vitamin E (α-tocopherol, α-T and γ-tocopherol, γ-T) and its cytochrome P-450 metabolites: 13′-hydroxychromanol (α-13'-OH), 13′-carboxychromanol (α-13'-COOH) and carboxyethyl hydroxychromanols (α-CEHC and γ-CEHC), was developed and validated. After enzymatic hydrolysis and deproteinization, the metabolites were extracted with a mixture of hexane/ methyl tertiary butyl ether (2/1, v/v). The separation was achieved by reversed phase chromatography and the analytes detected by a triple quadrupole mass analyser using electrospray ionization in positive mode (LC-MS/MS). α-T and γ-T were extracted separately without enzymatic hydrolysis. The analytes were quantified with the isotopic dilution method. After an extensive validation study (three levels in three different occasions for a total of 54 experiments), the procedure was successfully applied to the analysis of sera of healthy volunteers (before and after supplementation with α-T) and plasma of patients affected by chronic kidney disease. Finally, the structures of three unknown compounds found in blood and related to the long chain metabolites (α-13'-OH and α-13'-COOH) were further investigated using liquid chromatography coupled to high resolution mass spectrometry (LC-HRMS)
Photopheresis abates the anti-hla antibody titer and renal failure progression in chronic antibody-mediated rejection
No full textObjective: Chronic renal antibody-mediated rejection (ABMR) is a common cause of allograft failure, but an effective therapy is not available. Extracorporeal photopheresis (ECP) has been proven successful in chronic lung and heart rejection, and graft versus host disease. The aim of this study was to evaluate the effectiveness of ECP in chronic ABMR patients. Patients and Methods: We investigated ECP treatment in 14 patients with biopsy-proven chronic ABMR and stage 2–3 chronic renal failure. The primary aim was to e valuate the eGFR lowering after 1 year of ECP therapy. The ECP responders (R) showed eGFR reduction greater than 20% vs the basal levels. We also evaluated the effectiveness of ECP on proteinuria, anti-HLA antibodies (HLAab), interleukin 6 (IL-6) serum levels, and CD3, CD4, CD8, CD19, NK, Treg and T helper 17 (Th17) circulating cells. Results: Three patients dropped out of the study. The R patients were eight (72.7%) out of the 11 remaining patients. Because ECP was not associated with any adverse reaction, the R patients continued such treatment for up to 3 years, showing a persisting eGFR stabilization. Twenty four hour proteinuria did not increase in the R patients over the follow-up when compared to the non-responder patients (NR). In the R patients, the HLAab levels were reduced and completely cleared in six out of eight patients when compared with the NR patients. The NR HLAab levels also increased after the discontinuation of the ECP. The ECP in the R patients showed a decrease in CD3, CD4, CD8, CD19, and NK circulating cells. The ECP treatment in the R patients also induced Tregs and Th17 cell increases, and a decrease of the IL-6 serum levels. Conclusions: ECP abates the HLAab titer and renal failure progression in patients with chronic renal ABMR, modulating the immune cellular and humoral responses
Antineutrophil cytoplasmic antibody- associated renal vasculitis treated with autologous mesenchymal stromal cells: Evaluation of the contribution of immune-mediated mechanisms
No full textWe report the first case of renal antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis treated with autologous mesenchymal stromal cells (MSCs). A 73-year-old man was admitted to the hospital for malaise, weight loss, and oliguria. His serum creatinine level was 2.7 mg/dL but it rapidly increased to 7.8 mg/dL; urinalysis showed proteinuria and hematuria, and the ANCA to myeloperoxidase with a perinuclear pattern (pANCA) titer was high (132 IU/mL). Renal biopsy showed necrotizing crescentic glomerulonephritis. Standard immunosuppressive therapy (cyclophosphamide and corticosteroids) was ineffective. Rituximab therapy was started, but it was discontinued after the third dose to minimize the risk of systemic spread of a severe oral Candida infection and to prevent superinfections that were facilitated by leukopenia. The patient received autologous MSCs, 1.5 x 10(6) cells/kg body weight, intravenously. After 7 days, his serum creatinine level decreased to 2.2 mg/dL, pANCA titer decreased to 75 IU/mL, and urinalysis findings normalized. Eight months later, he received a second MSC infusion because his serum creatinine level increased. In 1 week, his creatinine level decreased to 1.9 mg/dL and his pANCA titer decreased to 14 IU/mL. Immunosuppressive therapy was subsequently withdrawn. At the last follow-up visit, 12 months after the second MSC infusion, the patient remained in clinical remission without any therapy. Infusion of MSCs induced expansion of the T-lymphocyte subset expressing a regulatory T-cell phenotype (CD4(+)CD25(+)Foxp3(+)) and a notable reduction in interferon-gamma, interleukin 6, and tumor necrosis factor serum levels. (c) 2013 Mayo Foundation for Medical Education and Researc
Hemoperfusion with CytoSorb as Adjuvant Therapy in Critically Ill Patients with SARS-CoV2 Pneumonia
No full textWe report a preliminary experience of adjuvant therapy with Hemoperfusion (HP) in patients with Severe Acute Respiratory Syndrome-CoronaVirus 2 (SARS-CoV2) pneumonia. Currently, there are no approved treatments for CoronaVirus Disease 19 (COVID-19); however, therapeutic strategies based on the preclinical evidence include supportive measures, such as oxygen supplementation, antiviral, and anticoagulant agents. Despite these treatments, 10% of patients worsen and develop severe acute respiratory distress syndrome (ARDS). Since the pathogenic mechanism of ARDS is an uncontrolled inflammatory state, we speculate that removing inflammation effectors from blood may contrast tissue injury and improve clinical outcome. In a scenario of dramatic medical emergency, we conducted an observational study on 9 consecutive patients hospitalized in COVID Intensive Care Unit, where 5 of 9 consecutive patients were treated with HP, due to the emergency overload made it impossible to deliver blood purification in the other 4 patients. COVID-19 was diagnosed through the identification of virus sequences by reverse transcription-PCR on respiratory specimens. All patients had severe pneumonia requiring continuous positive airway pressure. HP was started in all patients 6-7 days after hospital admission. The treated patients (T) received 2 consecutive sessions of HP using CytoSorb cartridge. Our results show a better clinical course of T compared to control patients (C), in fact all T except 1 survived, and only 2 of them were intubated, while all C required intubation and died. Lymphocytopenia worsened in C but not in T. C-reactive protein decreased in both patients, but to a greater extent in T. IL-6, IL-8, and TNF-α decreased after HP, IL-10 did not change. Respiratory function remained stable and did not worsen in T compared to C. The limited sample size and observational study design preclude a sound statement about the potential effectiveness of HP in COVID-19 patients, but our experience suggests a potential therapeutic role of adjuvant CytoSorb HP in the early course of CO-VID-19 pneumonia. A randomized clinical trial is ongoing
Corporate valuations and the merton model
No full textIn recent years both practitioners and academics have realised that traditional discounted cash flow models erroneously consider the option value embedded in firms. Hence equity and debt valuation methodologies based on option theory have recently become quite popular. Such methodologies take inspiration from the Merton (1974) model which was originally introduced to measure the impact of default risk on corporate bonds yields. Thirty years later the Merton model for its simplicity and rigour remains unrivalled and is the basis of some of the most sophisticated credit risk models. In this paper it will be shown how practitioners often improperly adapt the Merton model for aims beyond its original scope.Merton model, option pricing, default risk, corporate bond.
