The E3 ubiquitin ligase WWP1 sustains the growth of acute myeloid leukaemia.

The E3 ubiquitin ligase (E3) WWP1 is an oncogenic factor implicated in the maintenance of different types of epithelial cancers. The role of WW domain-containing E3 ubiquitin protein ligase 1 (WWP1) in haematological neoplasms remains unknown. Acute myeloid leukaemia (AML) is characterized by the expansion of malignant myeloid cells blocked at different stages of differentiation. Here we report that the expression of WWP1 is significantly augmented in a large cohort of primary AML patients and in AML cell lines, compared with haematopoietic cells from healthy donors. We show that WWP1 inactivation severely impairs the growth of primary AML blasts and cell lines in vitro. In vivo, we observed a reduced leukaemogenic potential of WWP1-depleted AML cells upon transplantation into immunocompromised mice. Mechanistically, WWP1 inactivation induces the accumulation of its protein substrate p27Kip1, which ultimately contributes to G0/G1 cell cycle arrest of AML blasts. In addition, WWP1 depletion triggers the autophagy signalling and reduces survival of leukaemic cells. Collectively, our findings provide molecular insights into the anti-cancer potential of WWP1 inhibition, suggesting that this E3 is a promising biomarker and druggable target in AML.

Purity and stability of online-prepared hemodiafiltration fluid after storage.

BACKGROUND/AIMS: Previous studies have suggested that online hemodiafiltration (OL-HDF) fluid can be used as dialysate for continuous renal replacement therapies, and thus HDF costs can be reduced. The aims of this study were to determine the purity of OL-HDF fluid and to verify the stability of the electrolyte composition and acid-base balance during its storage. METHODS: OL-HDF fluid was collected in 70 individual bags and stored for up to 7 days. The following tests were performed daily in 10 bags: natural visible precipitation (macrocrystallization), sample collection for chemical analysis and fluid culture, limulus amebocyte lysate endotoxin test, standard culture of NALGENE® filters after passing of the fluid, and molecular analysis of bacterial DNA. RESULTS: The values of pH and pCO(2) showed a significant change starting at 24 h (p < 0.001); after 72 h, their values were beyond the measurable range. Coefficient of variation for pCO(2) was as high as 25.7%. Electrolyte composition (Na(+), K(+), Cl(-), Ca(2+) and glucose) showed a statistically significant difference over time (p < 0.05); however, their coefficients of variation were low (1.7, 1.4, 0.6, 2.3 and 0.9%, respectively), which might not be considered clinically significant. Negative results were obtained at all points by fluid and filter cultures, endotoxin test and molecular analysis. No macrocrystallization was observed at any time point. CONCLUSIONS: We demonstrate the microbiological purity of OL-HDF fluid stored for up to 7 days. The electrolyte composition was stable, except for a relevant change in pCO(2) and consequently in pH (first noted at 24 h), emphasizing the need to reassess the acid-base balance in multilayer plastic bags in future studies.

Body composition and heart rate variability to achieve dry weight and tolerance.

Autonomic dysfunction in patients with end- stage renal disease is associated with poor prognosis. Heart rate variability (HRV), determined by the standard deviation of the normal R- R interval, has been reported to be a useful evaluation of cardiac autonomic modulation. The relationship between HRV and hydration status (HS) can be analyzed by whole body bioimpedance spectroscopy. This allows a classification of patients according the combination of HS with predialysis systolic blood pressure. Differences in HRV can be studied in patients with high over hydration, but normal or low blood pressure, with respect to fluid-overloaded/hypertensive patients and normohydrated/normotensive patients. In conclusion, the assessment of the autonomic nervous system response to the hemodialysis treatment in end- stage renal disease patients, classified according to a reliable and quantitative measurement of their fluid overload, could permit better management of both arterial blood pressure and HS.

[A pilot study comparing pulse high volume hemofiltration (pHVHF) and coupled plasma filtration adsorption (CPFA) in septic shock patients]. / Coupled plasma filtration adsorption (CPFA) versus emofiltrazione continua con regime intermittente di alti volumi (pHVHF) nel trattamento dello shock settico: uno studio pilota.

High-volume hemofiltration (HVHF) and coupled plasma filtration adsorption (CPFA) have shown potential to improve the treatment of sepsis in animals, but there have been no studies comparing these two treatments in humans. Our aim was to compare the hemodynamic effects of HVHF and CPFA in septic shock patients with acute kidney injury (AKI) undergoing continuous renal replacement therapy (CRRT). We performed a cross-over study enrolling patients with septic shock and AKI who were receiving CRRT. Patients were treated with pulse HVHF and continuous veno-venous hemofiltration (CVV H) on day 1 and CPFA and CVV H on day 2 or vice versa. HVHF was performed for 8-10 hours with a replacement fluid rate of 85 mL/kg/h. CPFA was performed for 8-10 hours with a plasma flow rate of 15%. CVV H was performed for the rest of the day with a replacement fluid rate of 35 mL/kg/h. The primary endpoints were changes in mean arterial pressure, vasopressor requirement (expressed as vasopressor score, VS), and noradrenaline dose after pulse HVHF and CPFA. The two treatments were compared using nonparametric tests. We enrolled 8 patients (median age 70.5 years, SOFA 12.5, SAPS II 69.5). There was a trend towards a reduction in VS with HVHF and CPFA (HVHF p=0.13, CPFA p<0.05). There was no significant difference between the two treatments in terms of percentage change in VS score (p=0.22). The data from this pilot study provide no evidence for a difference in hemodynamic effects between pulse HVHF and CPFA in patients with septic shock already receiving CRRT. A larger sample size is needed to adequately explore this issue.

[Methylobacterium radiotolerans bacteremia in hemodialysis patients]. / Batteriemie da methylobacterium radiotolerans in pazienti emodializzati.

Central venous catheters (CVCs) play an important role in replacement therapy for patients with acute and chronic renal failure. Secondary infections due to central venous access are responsible for 48-73% of bacteremia in hemodialysis patients and are an important cause of morbidity and increased health costs for these patients. Episodes of unexplained fever were noted in hemodialysis patients in our center starting in October 2006. An investigation for causative microorganisms was conducted from October 2006 to April 2007. Bacterial DNA was extracted and amplified using universal primers for bacterial 16S. Amplification by multiple PCR was performed on the samples and the subsequent sequencing led to the identification of the microorganism of interest as belonging to Methylobacterium radiotolerans. We report the largest cluster of dialysis catheter-related bloodstream infections caused by M. radiotolerans, and describe the difficulties in the prompt and correct identification of these bacteria. Thirty-seven patients had positive cultures for M. radiotolerans from blood (2.7%) or CVC (29.7%) or both (67.6%). After removal and replacement of CVCs and antibiotic therapy and the strict application of an infection management protocol, there were no more fever episodes or cultures positive for M. radiotolerans.

Effect of vitamin E-coated dialysis membranes on anemia in patients with chronic kidney disease: an Italian multicenter study.

BACKGROUND: Increased oxidant stress is increasingly recognized as a crucial factor in anemia in patients with chronic kidney disease. Vitamin E-coated membranes (VECMs) consist of a multilayer membrane with liposoluble vitamin E on the blood surface allowing direct free radical scavenging at the membrane site, which is of potential clinical benefit. Our objective was to examine the effect of VECMs on anemia in chronic hemodialysis (HD). METHODS: We enrolled 172 stable chronic HD patients (94 men, 78 women, age 65.4 +/- 13.4 years) in an open-label multicenter study. They were shifted from their previous dialyzer to VECM for 1 year. Hemoglobin (Hb) levels and recombinant human erythropoietin (rHuEpo) dosage were analyzed after 4, 8, and 12 months on the VECM and compared with baseline values using paired tests. RESULTS: Hb significantly increased from 10.9 +/- 1.2 g/dL at baseline to 11.7 +/- 1.2 g/dL after 12 months (p<0.001) on VECMs. Conversely, the rHuEpo dosage decreased from 7,762 +/- 5,865 IU/week at baseline to 6,390 +/- 5,679 IU/week after 12 months (p<0.001). The proportion of patients who were at target Hb levels (European Best Practice Guidelines) increased from 49.4% at baseline to 80% after 12 months (p<0.001). CONCLUSIONS: Dialysis with VECM in stable chronic HD patients was associated with significantly improved Hb levels and lower rHuEpo requirements. These results suggest that the antioxidant properties of VECMs may impact favorably on anemia management in chronic HD patients. Possible mechanisms include enhanced membrane biocompatibility, reduced oxidative stress and inflammation with VECMs, resulting in improved red blood cell survival and/or rHuEpo responsiveness. This therapy may potentially contribute to more effective anemia management in hemodialysis patients, and merits further rigorous study.

A wearable hemofilter for continuous ambulatory ultrafiltration.

Ultrafiltration is effective for treating fluid overload, but there are no suitable machines for ambulatory treatment. This study summarizes the use of a light-weight wearable continuous ambulatory ultrafiltration device consisting of a hollow fiber hemofilter, a battery operated pulsatile pump, and two micropumps to control heparin administration and ultrafiltration. Six volume-overloaded patients underwent ultrafiltration for 6 h with treatment discontinued in one patient due to a clotted catheter. Blood flow averaged 116 ml min(-1), the ultrafiltration rate ranged from 120-288 ml h(-1) with about 150 mmol of sodium removed. Blood pressure, pulse, and biochemical parameters remained stable with no significant hemolysis or complications. Our data show that the wearable hemofilter appears to be safe, effective, and practical for patients. This device could have a major impact on the quality of life of fluid-overloaded patients with heart failure. Additional studies will be needed to confirm these initial promising results.

Aspectos clínicos e radiográficos do pericárdio bovino como substituto do ligamento cruzado cranial de cães / Clinical and radiographic aspects of the bovine pericardium as a substitute of the canine cranial cruciate ligament

Avaliaram-se os aspectos clínicos e radiográficos do enxerto de pericárdio bovino, preservado em glicerina, como substituto do ligamento cruzado cranial. Quinze cães machos, sem raça definida, pesando entre 17,4 e 31,6 kg, foram submetidos à ruptura experimental do ligamento cruzado cranial e à substituição por pericárdio, via videoartroscopia. Os cães foram divididos em três grupos de cinco e avaliados aos 30, 90 e 120 dias. O membro operado foi imobilizado por duas semanas e procederam-se avaliações clínicas semanais. Radiografias foram feitas mensalmente e foram realizadas colheita de líquido sinovial nos tempos descritos. Clinicamente, os cães mostraram claudicação acentuada a moderada, hipotrofia muscular no membro operado e acentuado deslocamento cranial da tíbia em relação ao fêmur. As alterações degenerativas foram observadas nas radiografias. Observou-se instabilidade acentuada em todos os animais. O líquido sinovial tinha características de inflamação. Concluiu-se que o enxerto rompeu precocemente, provocou reação inflamatória persistente e fenômenos de rejeição, não sendo, portanto, recomendado para substituição do ligamento cruzado cranial de cães

The clinical and radiographic aspects of the bovine pericardium preserved in glicerin, were evaluated as a substitute for canine cranial cruciate ligament. Fifteen male mongrel dogs weighing between 17.4 and 31.6kg had the ligament experimentally ruptured and the stifle joint stabilized by an arthroscopical technique with bovine pericardium as a graft. The dogs were divided into three groups of five animals each. They were evaluated at 30, 90 and 120 days. The operated limb was imobillized for two weeks and clinical examination was performed weekly. Radiographs were taken monthly and the sinovial fluid was collect at 30, 90 and 120 days. Clinically, dogs presented high to moderate lameness, muscle hipotrophy in the operated limb and accentuated cranial drawer movement. Degenerative disease was detected in radiography. All dogs showed total rupture of the graft. Sinovial fluid analysis showed characteristics of inflammation. It can be concluded that pericardium graft failed prematurely, incited persistent inflammatory reaction and rejection phenomena. Thus, it cannot be recommended as a xenograft for cranial cruciate ligament replacement

Integration of blood volume, blood pressure, heart rate and bioimpedance monitoring for the achievement of optimal dry body weight during chronic hemodialysis.

BACKGROUND: Achieving optimal dry body weight in hemodialysis is challenging. Clinical assessment alone is inadequate, and methods such as bioimpedance monitoring may be impractical for every patient treatment. Continuous blood volume monitoring, blood pressure and heart rate variability inform clinical decision-making, but integrated use of multiple methodologies to achieve dry weight and understand patient factors has not yet been described. METHODS: Nineteen chronic hemodialysis patients underwent thrice-weekly treatments for two weeks. Baseline hydration status and target weight were determined by bioimpedance. During subsequent treatments, ultrafiltration was adjusted and relative blood volume, blood pressure and pulse were recorded non-invasively. Bioimpedance was repeated to assess hydration. Response of variables to progressive change in weight was assessed and selected patients underwent additional autonomic function testing. RESULTS: Four distinct hemodynamic patterns emerged. Profile A: 4 patients demonstrated overhydration at baseline. With decreasing target, pulse and blood pressure remained stable while blood volume and bioimpedance demonstrated achievement of dry weight. Profile B: 8 patients demonstrated overhydration at baseline. With decreasing target, blood pressure remained stable while pulse increased. Profile C: 5 patients were overhydrated, but as weight decreased, blood pressure became unstable and heart rate failed to compensate. Further testing confirmed autonomic dysfunction. Profile D: 2 patients were dehydrated, and with increasing target demonstrated stable pulse and pressure, while blood volume and bioimpedance revealed achievement of dry weight. CONCLUSIONS: Integrating existing non-invasive, continuous monitoring during hemodialysis enabled achievement of dry weight and identified distinct profiles of the patients, some with autonomic dysfunction. This strategy may contribute to achieving optimum dry weight while improving cardiovascular tolerability of hemodialysis.

Dialytic performance evaluation of Rexeed: a new polysulfone-based dialyzer with improved flow distributions.

New dialyzers are designed to optimize the convective and diffusive components of solute transport. Asahi Kasei Medical Co.,Ltd.has developed a new high flux dialyzer series called Rexeed with improved flow distributions. We evaluated the in vivo dialytic performance of two dialyzers of the Rexeed series: Rexeed-18A and Rexeed-25A (1.8 m2 and 2.5 m2 ). We calculated the clearance for urea,creatinine,phosphate and b2-microglobulin both in high flux dialysis (HFD)and in 15 liter postidiluitional on-line hemodiafiltration (HDF)mode. With n = 3 patients in high flux HD at blood flow 450, 400, 350 and 250 ml/min we found remarkably high clearance for urea (347 +/- 4%, 305 +/- 0%, 288 +/- 5%, 230 +/- 3%, for Rexeed-18A and 361 +/- 3%, 329 +/- 0%, 313 +/- 1%, 234 +/- 3%for Rexeed-25A),creatinine (282 +/- 10%, 234 +/- 0%, 221 +/- 8%, 174 +/- 8%, for Rexeed-18A and 276 +/- 6%, 245 +/- 0%, 226 +/- 9%, 172 +/- 13% for Rexeed-25A),phosphate (347 +/- 0%, 316 +/- 0%, 275 +/- 4%, 202 +/- 16%, for Rexeed-18A and 364 +/- 3%, 365 +/- 0%,286 +/- 3%, 224 +/- 2% for Rexeed-25A)and b2-microglobulin (133 +/- 21%, 124 +/- 0%,118 +/- 12%, 98 +/- 11%, for Rexeed-18A and 159 +/- 8%, 169 +/- 0%,157 +/- 8%, 129 +/- 7% for Rexeed-25A) With n = 2 patients in HDF at blood flow 300 ml/min we found remarkably high clearance for urea (268 +/- 2%, for Rexeed-18A and 283 +/- 2% for Rexeed-25A),creatinine (183 +/- 6%for Rexeed-18A and 205 +/- 9% for Rexeed-25A),phosphate (245 +/- 3%, for Rexeed-18A and 270 +/- 2% for Rexeed-25A)and b2-microglobulin (166 +/- 12%, for Rexeed-18A and 192 +/- 4% for Rexeed-25A). Our preliminary evaluation describes the characteristics and the performances of a new polysulfone-based hemodialyzer series called Rexeed. Several innovative features have been implemented by the manufacturer. These constructive approaches seem to have produced a positive effect on the dialyzer performance at the bedside.

[Rationale for the use of extracorporeal treatments for sepsis].

Sepsis is the leading cause of disability and mortality among critical patients; moreover, it causes high economic expenditures. Although very much is known about the pathophysiology of this condition and its mediators despite great investments directed to its control, mortality rates remain high. Recent treatment manuals emphasize the value of early goal-oriented therapy and also point to the high efficacy of activated protein C. Extracorporeal blood clearance may potentially become a new approach to treating this condition. There are reports on its positive clinical results that are likely associated with the effective removal of septic mediators. Human and animal studies, few and rather alike as they are, have yielded promising results. It is evident that the use of these procedures is justified; however, their efficiency in sepsis requires large-scale, correctly conducted studies.

Sequential convective therapies (SCT): a prospective study on feasibility, safety, adequacy and tolerance of on-line hemofiltration and hemodiafiltration in sequence.

Sequential dialysis techniques (i.e pure ultrafiltration followed by dialysis) have been used in the past, due to their capability to remove large volumes of fluids without inducing hemodynamic instability. The disadvantages of inadequate efficiency and lack of technology lead to the decline of such methods. Hemofiltration (HF) and hemodiafiltration (HDF) are recently being utilized in a greater proportion thanks to on-line fluid preparation systems. Each process (HF and HDF) has its own benefits in the removal of small, medium and high-molecular weight substances and in hemodynamic stability. Sequential convective therapies (SCT) such as hemofiltration-hemodiafiltration in sequence (HF-HDF) may combine the benefits and eliminate the disadvantages of each method and should be studied in order to explore their potential application in modern dialysis. Furthermore they can be easily applied nowadays, due to the development of new sophisticated dialysis machines. In order to evaluate the feasibility, safety, efficiency and tolerance of different SCT methods we studied 3 schedules: SCT1: 1h pre-dilution HF followed by 3h of post-dilution HDF (in the HF mode we lost 25% of the total fluid that had to be removed). SCT2: 1h pre-dilution HF followed by 3h of post-dilution HDF (in the HF mode we lost 50% of the total fluid that had to be removed). SCT3: 2h pre-dilution HF followed by 2h of post-dilution HDF (in the HF mode we lost 50% of the total fluid that had to be removed). We studied 6 chronic hemodialysis patients using the same machine (AK200 ULTRA), with on-line fluid preparation system and the same type of dialyzer (Polyflux 210). SCT schedules were compared to on-line HF, on-line HDF and high flux dialysis performed with the same dialyzers. The treatments resulted safe, easy, feasible and well tolerated with an improved hemodynamic response to high volume convective therapies. Adequacy of treatment was satisfactory in all SCT schedules while middle molecular weight solute clearance and removal resulted higher in treatments with higher convective component. SCT might represent an interesting option for the future especially in patients with hemodynamic instability and requirements for interventions during treatment.

Sequential hemofiltration-hemodiafiltration technique: all in one?

Sequential dialysis techniques (i.e. pure ultrafiltration followed by dialysis) have been used in the past, due to their capability to remove large volumes of fluids without inducing hemodynamic instability. The disadvantages of the inadequate dialysis and the lack of technology lead to the decline such methods. Hemofiltration (HF) and hemodiafiltration (HDF) are recently being utilized in a greater proportion thanks to the on line fluid preparation systems. Each process (HF and HDF) has its own benefits in the removal of small, medium and high-molecular weight substances and in the hemodynamic stability. Sequential hemofiltration/ hemodiafiltration (SHF/HDF), may combine the benefits and eliminate the disadvantages of each method. Furthermore they can be easily applied nowadays, due to the development of new high technological hemodialysis machines. In order to evaluate the feasibility and the effects of SHF/HDF we studied 7 chronic hemodialysis patients (6 months of treatment with SHF/HDF switched to 6 months of SHDF/HF), using the same machine (AK200 ULTRA), with on line fluid preparation system and the same type of dialyzer (Polyflux 210). The feasibility of such techniques (SHF/HDF or vice versa) resulted excellent. All sessions left the patients in a condition of well-being making fulltime work. No difference was observed between the different period of treatment, but a reduction in pre value was observed in calcium-phosphorous product, C-reactive protein and beta2-microglobulin, at the end of the sequential techniques. SHF/HDF therapy is a very promising technique. Further studies are needed to better explore the potential of such a therapeutic approach in the quality of life, the hemodialysis adequacy and the hemodynamic stability of our patients.

First clinical trial for a new CRRT machine: the Prismaflex.

A new CRRT machine has been designed to fulfill the expectations of nephrologists and intensivists operating in the common ground of critical care nephrology. The new equipment is called "Prismaflex" (Gambro-Dasco, Mirandola, Modena) and it is the natural evolution of the Prisma machine that has been utilized worldwide for CRRT in the last decade. We performed a preliminary "alfa trial" to establish usability, flexibility and realiability of the new device. Accuracy was also tested by recording various operational parameters during different intermittent and continuous renal replacement modalities. Forty-one runs were conducted on 13 patients and the difference between delivered and prescribed parameters was always lower than 2%. We concluded that the new Prismaflex is a well designed new machine for CRRT and can be safely and effectively utilized in the critical care nephrology setting.

Pulse high volume hemofiltration.

The sepsis syndrome is the most common cause of acute renal failure and multiple organ dysfunction in critically ill subjects and continues to have an alarmingly high mortality. Normal immune homeostasis is interrupted by a complex storm of inflammatory mediators responsible for the deleterious effects. Extracorporeal blood purification techniques can confer benefits in sepsis by proven non-specific removal of these mediators (pro- or anti-inflammatory), and provide a logical and adequate approach to treat this syndrome. High volume hemofiltration (HVHF) has had the most dramatic effect conferring benefits in hemodynamics, reduction in vasopressor doses and improvement in survival. "Pulse HVHF" is the latest approach which may offer the most efficient results: a daily schedule of 6-8 hours followed by standard CVVH. This paper describes the rationale and potential of this technique. Reliability and tolerance of this technique and biological effects are described.

Continuous renal replacement technology: from adaptive devices to flexible multipurpose machines.

OBJECTIVE: To review the evolution of technologies in the development of renal replacement therapies. DATA SOURCES: Articles and published reviews on renal replacement therapies. SUMMARY OF REVIEW: Continuous arterio-venous haemofiltration (CAVH) was the first continuous renal replacement technique capable of overcoming the traditional haemodialysis-related side effects, making possible the treatment of critically ill patients safely and with less physiological instability. The evolution of technology and the progress experienced in intensive care units (ICUs) has made it possible to start renal replacement therapy programs in the absence of a chronic dialysis facility or a trained nephrological team. Initial limitations and draw-backs of CAVH, stimulated the ICU staff to explore new avenues for better therapy. Extracorporeal therapies are today a routine experience in the ICUs: continuous renal replacement therapies are a broadly accepted treatment for acute renal failure. Furthermore, alternative indications for extracorporeal blood circulation (e.g. sepsis, liver failure, congestive heart failure, drug intoxications, hyperthermia, immuno-mediated syndromes) are becoming more and more popular. The ideal machine has yet to be completed, but progress has occurred and has opened a new era for critical care nephrology and the further expansion of blood purification technology in the ICU. CONCLUSIONS: Technical advances in renal replacement therapies have increased their functionality (i.e. used in hepatic failure, sepsis, cardiac failure and immuno-mediated syndromes), are easier to operate and have less side-effects compared with their standard extracorporeal counterparts. Further improvements may see them become a routine part in the management of the critically ill patient.

Caspase-3 and -8 activation and cytokine removal with a novel cellulose triacetate super-permeable membrane in an in vitro sepsis model.

Pro-apoptotic molecules are generated during sepsis which may be responsible for alteration of organ function in sepsis. Removal of systemic apoptotic activity may affect recovery from sepsis. Current high flux membranes might not be sufficiently permeable to eliminate pro-apoptotic factors. We evaluated the elimination of pro-apoptotic factors induced by LPS in human whole blood by a super-permeable cellulose triacetate membrane (SUREFLUX FH 150, Nipro, Osaka, Japan) in comparison to a standard high flux cellulose triacetate membrane (UT 700, Nipro, Osaka, Japan) and a polyethersulfone plasmafilter (Bellco, Mirandola Italy) in an in vitro blood circulation. We spiked human whole blood with lipopolysaccharide from Escherichia coli (Serotype 026-86, 10 mg/ml), incubated it for 3 hours to allow cytokine generation and recirculated it at 300 ml/min for 3 hours. The UF line was first returned to the blood module at 10 min. After this, the UF was drained from 10 to 60 min at a rate of 1000 ml/h. Zero balance was obtained by re-infusion of bicarbonate buffered hemofiltration fluid. Apoptosis was assessed on U937 monocytes (incubated with plasma or ultrafiltrate) by fluorescence microscopy dyes (Hoechst 33342, propidium iodide) and annexin V flow cytometry. Caspase-3 and Caspase-8 activity was assessed on the recirculated blood monocytes by spectrophotometric methods. IL-2, IL-10 and TNFalpha were determined by commercially available ELISAs. Sieving coefficients and clearances were determined for the different cytokines. Caspase-3 and Caspase-8 were activated by LPS and remained either stable or increased during in vitro circulation. Apoptosis activity of U937 cells, when incubated with the ultrafiltrate, increased in parallel with arterial plasma values (for Uf: UT700 = 23.1%; Sureflux FH150 = 42.5%). However, by 60 min the apoptotic activity recorded with the ultrafiltrate was reduced to the levels of arterial plasma (for Uf: UT700 = 19.8%; Sureflux FH150 = 11.2%). Sieving coefficients in the super-permeable membrane were significantly higher for all measured cytokines in comparison to the standard high flux membrane (e.g. TNFalpha 0.72 vs 0.03 p < 0.001) and close to the values observed for the plasmafiltration membrane. Nevertheless protein losses measured by albumin leakage were much lower with the Sureflux filter in comparison to the plasmafilter. In conclusion, pro-apoptotic factors can be eliminated by dialytic membranes with the removal rate maximized by using super high flux dialysers which may represent a compromise between hemofiltration and plasmafiltration membranes.

Effects of novel manufacturing technology on blood and dialysate flow distribution in a new low flux "alpha Polysulfone" hemodialyzer.

The main target for low flux hemodialyzers is an efficient low molecular weight solutes clearance. Such efficiency is largely dependent on the optimization of diffusion between blood and dialysis solution. The diffusion process can be impaired if there is a mismatch between blood and dialysate flow distribution in the dialyzer. Thus optimized flow distribution both in the blood and dialysate compartment becomes quintessential for the maximal efficiency of the diffusion process within the hemodialyzer. The present paper describes the distribution of the blood and dialysate flows in a new low flux polysulfone hollow fiber hemodialyzer characterized by a specific undulation of the fibers and a new cutting technology of the fibers for an improved micro-flow condition in the blood compartment headers. Twelve Diacap alpha Polysulfone LO PS 15 (1.5 sqm) (B. Braun Medizintechnologie, Melsungen Germany) were employed for the study. Six were analyzed in vitro and six were studied in vivo. Blood flow distribution was studied in vitro by dye injection in the blood compartment during experimental extracorporeal circulation utilizing human blood with hematocrit adjusted at 33%. Sequential images were obtained with a helical scanner in a fixed longitudinal section of the dialyzer 1 cm thick. Average and regional blood flow velocities were measured utilizing the reconstructed imaging sequence. The method allowed the calculation of single fiber blood flow (SF Qb) and the mass transfer zone (MTR) definition in digitally subtracted images. The patterns 20-10 and 40-30 were utilized. The same technology was used to evaluate flow distribution in the dialysate compartment after dye injection in the Hansen's connector. Regional dialysate flow was calculated in central and peripheral sample areas of 1 cm2. Six in vivo hemodialysis treatments on patients with end stage renal disease were performed at three different blood flow rates (250-350 and 450 ml/min) in order to measure urea, creatinine and phosphate clearance. Macroscopic and densitometrical analysis revealed that flow distribution was homogeneous in the blood compartment while in the dialysate compartment a slight difference between the peripheral and central regions in terms of flow velocity was observed. This however was not generating channeling phenomena. Urea creatinine and phosphate clearances were remarkably high and so were the Kt/V observed in all sessions, especially in relation to the studied blood flows. In conclusion, a significant blood to dialysate flow match with optimized countercurrent flow condition was observed in the studied hollow fiber hemodialyzers. Such optimization might be due both to the improved dialyzer design at the level of the blood header and to the specific fiber undulation that prevents dialysate channeling.

Iron management in hemodialysis patients: optimizing outcomes in Vicenza, Italy.

The management of anemia in uremic patients undergoing hemodialysis requires the appropriate combination of erythropoietin treatment, iron supplementation, and on occasion androgen therapy. Identifying and correcting functional iron deficiency is crucial to optimizing erythropoietin efficiency. Recently, however, the trend to administer maintenance iron with resultant high serum ferritin and high transferrin saturation has led to an increase in reports of iron overload. Oral iron supplementation is inexpensive and safe, but poor patient compliance and reduced intestinal absorption may limit its efficacy. Intravenous iron, on the other hand, is effective, and its safety is related to the iron salt used. Currently available data suggest that iron saccharate may be the safest iron salt available for intravenous administration, although iron gluconate is safer than the dextran forms of intravenous iron. It should be kept in mind, however, that all forms of intravenous iron may have the potential of inducing iron overload. At this time, the levels of ferritin that define iron overload are not clearly established. The side effects of iron overload are well recognized (infections, malignancies, vascular diseases); however, no guidelines exist for safe practice. There are many markers of iron deficiency, with serum ferritin and hypochromic red cell percentage currently the best markers available in clinical practice.