Long-Term Outcomes after Transcatheter Mitral Valve-in-Valve or Valve-in-Ring Procedures.

Background: Redo mitral valve surgery is the standard of care for failed mitral bioprostheses or recurrence of mitral regurgitation after repair. Nonetheless, catheter-based valve-in-valve (ViV) or valve-in-ring (ViR) procedures have increasingly become viable alternatives in high-risk subpopulations. Despite reported good initial results, little is known about longer-term outcomes.

Substitution of citrate with tissue plasminogen activator (rt-PA) for catheter lock does not improve patency of tunnelled haemodialysis catheters in a randomised trial.

Backround: The study aim was to establish if substitution of citrate with rt-PA for catheter lock once weekly can reduce the incidence of catheter-related blood stream infections (CR-BSI) or improve patency of tunneled haemodialysis catheters.

Methods: All incident patients undergoing insertion of a tunneled haemodialysis catheter were screened and included except those suffering infection or using oral anticoagulation. Study participants were randomized into two arms according to the solution applied as catheter lock: receiving either trisodium citrate (Citra-LockTM 4%) only or rt-PA (Actilyse® 1 mg/ml) on the middle session each week with citrate used on the first and third sessions.

Citrate-Buffered Dialysis Solution (Citrasate) Allows Avoidance of Anticoagulation During Intermittent Hemodiafiltration-At the Cost of Decreased Performance and Systemic Biocompatibility.

Reportedly, citrate-based dialysis solution enables heparin dose tapering or even complete exclusion, particularly in postdilution hemodiafiltration (HDF). The aim of the study was to verify this strategy in predilution setting and to assess its short-term safety, efficacy, and biocompatibility. Ten regular hemodialysis patients were assigned to predilution HDF on acetate- and citrate-based dialysis solutions (0.

Previous Vaccination and Age are More Important Predictors of Immune Response to Influenza Vaccine than Inflammation and Iron Status in Dialysis Patients.

Background/aims: The immune response to influenza vaccine may be influenced by many factors, e.g. age, comorbidities or inflammation, and iron status.

Asymmetric dimethylarginine and progression of chronic kidney disease: a one-year follow-up study.

Background/aims: Asymmetric dimethylarginine (ADMA) is a prognostic factor in patients with chronic kidney disease (CKD). However, the relationships among factors influencing the metabolism of ADMA and the CKD progression are not fully understood.

Methods: Serum ADMA, and variables related to the metabolism of ADMA were measured in 181 non-dialysis patients (CKD stages 3-5) and in 46 controls.

A promising DNA methylation signature for the triage of high-risk human papillomavirus DNA-positive women.

High-risk human papillomavirus (hrHPV)-DNA testing is frequently performed parallel to cytology for the detection of high-grade dysplasia and cervical cancer particularly in women above 30 years of age. Although highly sensitive, hrHPV testing cannot distinguish between HPV-positive women with or without clinically relevant lesions. However, in principle discrimination is possible on the basis of DNA methylation markers.

Relationship between hepcidin and ferritin in haemodialysed patients.

Background: Hepcidin is a key regulator of iron metabolism. It binds to ferroportin and causes the trapping of iron in cells, rendering it unavailable for erythropoiesis. The synthesis of hepcidin is upregulated by high iron stores and inflammation.

Seroprevalence of hantavirus antibodies among chronic hemodialysis patients in the Czech Republic.

A total of 348 serum samples were collected from 301 hemodialysis patients with chronic renal failure of four healthcare settings in Western Bohemia. The sera were screened for the presence of hantavirus antibodies using ELISA kits (PROGEN Biotechnik GmbH) with Hantaan and Puumala antigens. Specific anti-Puumala antibodies were detected in five patients (1.

Asymmetric dimethylarginine in hemodialysis, hemodiafiltration, and peritoneal dialysis.

Asymmetric dimethylarginine (ADMA) is a mediator of endothelial dysfunction. Production and elimination of ADMA may be affected by the type of renal replacement therapy used and oxidative stress. Plasma ADMA, advanced glycation end products (AGE), and homocysteine were assessed in 59 subjects: 20 hemodialysis (HD) patients, 19 patients undergoing peritoneal dialysis (PD), and 20 controls.

High ferritin, but not hepcidin, is associated with a poor immune response to an influenza vaccine in hemodialysis patients.

Background: The immune response to vaccination in hemodialysis (HD) patients can be influenced by disorders of iron metabolism, iron overload or chronic inflammatory state. Elevated levels of hepcidin are considered a new marker of iron metabolism impairment and anemia of inflammation in HD patients.

Methods: We studied the effects of hepcidin, other markers of iron status and intravenous iron (Fe(iv)) on the response to an influenza vaccine (Influvac(R) subunit 2008/2009) in 40 HD patients.

Cell-free plasma DNA during peritoneal dialysis and hemodialysis and in patients with chronic kidney disease.

The mechanisms of clearance of circulating plasma DNA are not fully understood, and so we aimed to examine it in patients with impaired renal function compared with healthy individuals. We also assessed the effect of peritoneal dialysis and hemodialysis on circulating plasma cell-free DNA (cfDNA) in our treated patients. Overall, 20 healthy volunteers, 20 patients with chronic kidney disease (CKD), 18 patients undergoing peritoneal dialysis (PD), and 17 patients on hemodialysis (HD; high-flux polysulfone membrane) were examined.

The effect of intravenous iron on oxidative stress in hemodialysis patients at various levels of vitamin C.

Background/aims: Vitamin C levels decrease during hemodialysis (HD), which deteriorates antioxidant defense. Vitamin C may also act pro-oxidatively, via reduction in Fe(III). We sought to determine whether intravenous iron (Fe(iv))-induced oxidative stress differs in HD patients with low and physiological vitamin C levels and whether intravenous vitamin C (C(iv)) administration during HD would change the response to Fe(iv).

Brain natriuretic peptide and N-terminal proBNP in chronic haemodialysis patients.

Background: Brain natriuretic peptide (BNP) and N-terminal proBNP (NT-proBNP) are released into circulation as a result of congestive heart failure (HF). As HF and water overload are frequent complications in haemodialysis (HD) patients, we decided to study the levels of BNP and NT-proBNP and their changes during HD.

Methods: BNP and NT-proBNP levels were determined in 94 HD patients before and after a regular 4-h HD.

Asymmetric dimethylarginine, homocysteine and renal function--is there a relation?

The adverse effect of hyperhomocysteinemia on the vascular wall can be partially explained by increasing plasma concentration of asymmetric dimethylarginine (ADMA), a potent inhibitor of nitric oxide synthase. The aim of the study was to compare ADMA and homocysteine levels in three groups of subjects: blood donors with normal homocysteine concentration (group A), patients with hyperhomocysteinemia and normal kidney function (group B) and hemodialysis patients who are known to be hyperhomocysteinemic (group C). Concentrations of homocysteine (enzymatic method), ADMA (enzyme-linked immunoassay) and creatinine (Jaffe method) in EDTA plasma were measured.

[Free radicals and extracorporeal renal replacement therapy].

Free radicals (FR), highly reactive substances with an unpaired electron in the outer orbital attack lipids, proteins and nucleic acids and alter the structure and function of these macromolecules. Against the negative effects of FR during evolution various defense mechanisms developed described comprehensively as antioxidant defense. Under physiological conditions in the organism equilibrium is established between free radical production and antioxidant defense factors.

Fibrinolysis defect in long-term hemodialysis patients with type 2 diabetes mellitus and its relation to metabolic disorders.

Background/aims: Patients with chronic renal failure (CRF) secondary to diabetes mellitus show a high incidence of atherosclerosis with its thrombotic complications. Both CRF and type 2 diabetes mellitus (DM2) results in fibrinolysis defects causally related to atherogenesis and thrombogenesis. It is not well known whether or not and, if so, how fibrinolysis is altered in patients with both CRF and DM2.

[Transitional elements and free radicals].

Iron and copper are essential trace elements, which in certain conditions, namely in the ionised form or in low-molecular complexes, can participate in single electron reactions and catalyse formation of free radicals, including the dangerous hydroxyl radical. Similar behavior have also some other transitive metals. Our overview is aimed on the role of transitive elements in the formation of free radicals and on the mechanisms that organisms have to prevent it.

Oxidative stress: the effect of erythropoietin and the dialysis membrane.

Dialysis patients run the risk of impaired antioxidative defense and increased free radicals (FR) production. The study was made in order to compare FR-related parameters in ten patients treated with erythropoietin (EPO+) and ten patients not subject to this treatment (EPO-). All patients showed stable hemoglobin levels at > 95 g/L.

Does treatment modality have an impact on anemia in patients with chronic renal failure? Effect of low- and high-flux biocompatible dialysis.

Renal anemia significantly affects the morbidity and mortality of dialysis patients. The aim of the present study was to establish whether the severity of anemia and success of its treatment differs when using high-flux (HF) or low-flux (LF) hemodialysis. Twenty-five patients on long-term hemodialysis with a mean hematocrit (Hct) of 33%, S alb of 36 g/L, and Kt/V urea of 1.

Effects of a vitamin E-modified dialysis membrane and vitamin C infusion on oxidative stress in hemodialysis patients.

Hemodialysis deteriorates oxidative stress. Vitamin E is an antioxidant whose regeneration is provided for by vitamin C. The authors tested the effects of a vitamin E-modified membrane (E), nonmodified cellulose membrane (O), and vitamin C infusion (500 mg, C) into the arterial blood line during dialysis on parameters of oxidative stress.

[Paired filtration dialysis and free radicals].

Background: Extracorporeal dialysis compensating kidney function represents a risk of elevated production of free radicals (FR). Paired filtration dialysis (PFD) is a hemodialysing method used to compensate kidney function. The aim of our work was to study effects of PFD with two types of hemodiafilters on the activity of free radicals.

The effect of hemodialysis and acetate-free biofiltration on anemia.

The authors monitored, for a period of 12 months, anemia-, nutrition-, and free radical-related parameters and the rHuEPO dose required to maintain target hemoglobin (Hb) in 20 patients with chronic renal failure. Ten patients each were randomized for treatment by either acetate-free biofiltration (AFB) or low-flux hemodialysis (HD). At baseline, Hb levels were 102+/-2 (AFB) vs.

[Hemodiafiltration].

Haemodiafiltration (HDF) is renal replacement therapy. It is a method of blood clearance based on the principle of diffuse and convection transport of substances through a semipermeable membrane. The method uses high-flux membranes, usually synthetic ones with a high ultrafiltration coefficient.

[Paired filtration dialysis--evaluation of effectiveness of the method].

Paired filtration dialysis (PFD) is a haemodiafiltration method which uses in a major way the convection as well as the diffusion principle of blood clearance. It is the only method replacing renal function where blood filtration is separated from diffusion. The objective of the study is to make the medical community familiar with this method and to assess the effectiveness of PFD when two types of haemodiafilters are used.

The effects of a polyacrylonitrile membrane and a membrane made of regenerated cellulose on the plasma concentrations of erythropoietin during hemodialysis.

In vitro studies have shown that some dialysis membranes significantly adsorb erythropoietin (EPO), a fact that might have an effect on anemia in long-term hemodialysis (HD) patients and on anemia treatment with recombinant human EPO. The purpose of the study was to determine whether the ability of adsorption demonstrated in vitro also has an effect on EPO concentrations in vivo. In a crossover study, the plasma concentrations of EPO were examined in 11 patients on chronic HD during HD using a polyacrylonitrile (AN69) membrane (high in vitro adsorption) plus EPO administered subcutaneously after the HD session, HD using a Cuprophan membrane (low in vitro adsorption) plus EPO administered subcutaneously after the HD session, HD using an AN69 membrane plus EPO administered subcutaneously after the HD session plus EPO administered intravenously immediately before HD, or HD using a Cuprophan membrane plus EPO administered subcutaneously after the HD session plus EPO intravenously immediately before HD.