Polymethylmethacrylate dialyzer

Polymethylmethacrylate (PMMA) membrane is the first synthetic polymeric hollow fiber used in dialyzers that is known to adsorb beta(2)-microglobulin. Polyester polymer alloy (PEPA), a blend of two polymers, i.e., polyarylate and polyethersulfone, is another dialysis membrane material with adsorption characteristics. In this study, the adsorption and permeation characteristics of BG-1.6PQ (PMMA) and FLX-15GW (PEPA) dialyzers were investigated by performing ultrafiltration experiments using chymotrypsinogen (molecular weight 25,000) and albumin (molecular weight 66,000) as test solutes...

Choosing dialyzers is more important in blood purification in critical care because therapeutic conditions (especially the amount of dialysate) are usually limited. Then, adsorption is the third major mechanism of removing toxic substances from patients in these treatments. Several commercial dialyzers designed for acute blood purification therapy were investigated by performing aqueous ultrafiltration experiments to demonstrate the importance of the membrane materials. Polymethylmethacrylate (PMMA) showed strong adsorptive characteristics to alpha-chymotripsinogen A (MW 25,000) but showed much less adsorptive characteristics to cytochrome C (MW 12,400)...

AIM: Changes in plasma immunoreactive insulin (IRI) and connecting-peptide immunoreactivity (CPR) concentrations during hemodialysis (HD) were evaluated in diabetic HD patients with 3 different high-flux membranes. The removal properties of the membranes were compared. METHOD: In this prospective controlled study, 15 stable diabetic patients on HD were randomly selected for 6 HD sessions with 3 different membranes: polysulfone (PS), cellulose triacetate (CTA), and polymethylmethacrylate (PMMA)...

Alterations in plasma insulin and C-peptide concentrations following hemodialysis were evaluated using five types of dialyzer, which made of polysulphone, polyethersulfone, cellulose triacetate, polymethylmethacrylate, and polyester-polymer alloy, in diabetic patients. Plasma insulin and C-peptide were cleared by hemodialysis; their clearance rates and reduction rates differed across dialyzer types.

Uremic pruritus is one of the common complications in long-term dialysis patients. Recently, researchers reported that immunohypothesis with high serum level of cytokines could be the cause of uremic pruritus. Polymethylmethacrylate (PMMA) artificial kidney (AK) has been reported to adsorb more serum cytokines than other high-flux AKs. In July 2006, 30 patients with severe uremic pruritus from 300 chronic hemodialysis (HD) patients in a single center entered this prospective study. Their dialyzers were changed to PMMA AK for 4 weeks...

BACKGROUND: Advanced glycation end-products (AGEs) are now considered to contribute to the middle molecule toxicity of uremia and, because they are not cleared by conventional low-flux hemodialysis, alternative strategies are needed to improve their removal. METHODS: In a prospective cross-over trial involving 18 adult chronic hemodialysis subjects, we evaluated the intradialytic removal and the long-term effect on predialysis levels of Protein-bound (PBPe) and Free (FPe) pentosidine by high-pore, protein-leaking BK-F Polymethylmethacrylate-based hemodialysis (BK-F-HD), by comparing it to hemodialysis using low-flux dialyzers (LF-HD)...

BACKGROUND: Hyperhomocysteinemia is a well-recognized independent risk factor for cardiovascular disease in end-stage renal disease (ESRD) patients. Since homocysteine (Hcy) largely binds to serum proteins (80 to 90%), in this study we investigated the possibility that polymethylmethacrylate (PMMA)-based protein-leaking dialyzers could reduce total plasma Hcy (tHcy) levels in ESRD patients. METHODS: Two matched groups of patients (N = 13) showing mild to intermediate hyperhomocysteinemia on standard hemodialysis (HD) with conventional non-protein-leaking dialyzers were included...

Degranulation of polymorphonuclear leukocytes (PMNL) occurs during extracorporeal circulation. A degranulation-inhibiting protein identical to angiogenin was recently isolated from high-flux dialyzer ultrafiltrate. This protein inhibits the release of lactoferrin and metalloproteinases from PMNL in vitro. In the present study, we investigated end-stage renal disease patients undergoing regular hemodialysis treatment with either high-flux dialyzers (n = 51) or low-flux dialyzers (n = 44), and chronically uremic patients undergoing hemodiafiltration (n = 30)...

To examine effects of dialyzer membranes and anticoagulants on hemodialysis (HD)-triggered neutrophil degranulation. We measured plasma myeloperoxidase (MPO) and elastase (ELT) by an enzyme-linked immunoabsorbent assay. During routine HD with a cuprophane membrane and high molecular weight (HMW) heparin, plasma MPO was rapidly upregulated to maximal levels within 15 min after starting extracorporeal circulation. In contrast, the level of plasma ELT gradually increased such that the highest level was achieved at the end of the procedure...

In order to improve the biochemical reactivity of the cellulose polymer, which is mainly attributed to the presence of surface hydroxyl groups, derivatized cellulosic membranes have been engineered replacing or masking some or all of the hydroxyl groups in the manufacturing process of the membrane. The present study was set up to analyze both biocompatibility and functional performance of two different derivatized cellulosic membranes (cellulose diacetate; polyethylene glycol, PEG, acid-grafted cellulose) as compared to a synthetic membrane (polymethylmethacrylate, PMMA)...

BACKGROUND: Interleukin-6 (IL-6) exerts its actions through a cell-surface receptor system that consists of two transmembrane subunits: the IL-6 binding glycoprotein gp 80 (IL-6R) and the signal-transducing component (gp 130). Soluble forms of the IL-6R (sIL-6R) are generated by shedding of the membrane-associated proteins. The sIL-6R binds the ligand IL-6 with comparable affinity as the membrane-associated IL-6R and enhances the actions of IL-6. METHODS: Our aim was to evaluate the role of both uremia and different dialysis membranes on peripheral blood mononuclear cell (PBMC) release (either in absence or in presence of mitogen stimulation) and plasma levels of sIL-6R...

Interleukin-12 (IL-12) is a cytokine produced by peripheral blood mononuclear cells (PBMC) that causes interferon-gamma (IFN-gamma) production and enhancement of cell-mediated cytotoxicity. To clarify the role of hemodialysis biocompatibility on IL-12 production and uremic immunodeficiency, we have studied the IL-12 and IFN-gamma release by PBMC harvested from 12 patients dialyzed with cuprophan membrane (CU), eight patients dialyzed with polymethylmethacrylate membrane (PMMA), and eight nondialyzed uremic patients (UR)...

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The membranes tested in the present study were cellulose triacetate (CTA), polymethylmethacrylate (PMMA), and polyacrylonitrile (PAN). The adsorption by each membrane of albumin, IgG, C3a, interleukin-1beta (IL-1beta), interleukin-6 (IL-6), human neutrophil elastase (HNE), and tumor necrosis factor alpha (TNFalpha) was examined and semiquantitatively graded by confocal laser scanning fluorescence microscopy (CLSFM). After clinical use the dialyzers were treated with antibodies for these proteins and cytokines...

The aim of this study was to compare the effect on beta2-microglobulin (beta2-M) plasma levels of dialyzers with 3 low-flux synthetic membranes and regenerated cellulose (Cuprophan) in 12 chronic dialysis patients. The synthetic membrane materials chosen were low-flux polymethylmethacrylate (PMMA), low-flux polysulfone (PS 400), and polycarbonate-polyether (Gambrane). Adequate and comparable removal of small solutes was provided by dialyzers with all 4 membrane materials used under similar conditions. A significant reduction of beta2-M plasma levels was seen only with Gambrane while the other 2 synthetic membrane materials gave rise to increases similar to those known to occur with Cuprophan...

OBJECTIVE: To investigate the biocompatibility of dialyzer reuse. METHODS: Twenty-two hemodialysis patients were randomized into cuprophan (CU, 7), polymethylmethacrylate (PMMA, 7) and polysulphone (PS, 8) membrane groups to observe IL-1 beta, TNF-alpha, IL-6 gene expression and their plasma levels by using themselves as control with enzyme-linked immunosorbent assay (ELISA), reverse transcription-polymerase chain reaction (RT-PCR) and in situ hybridization. RESULTS: Plasma levels of interlukin-1 beta (IL-1 beta), tumor necrosis factor-alpha (TNF-alpha), interleukin-6 (IL-6) were 14...

Platelet interaction with neutrophils may occur to a significant degree during hemodialysis (HD). We have recently shown that the enhanced neutrophil reactive oxygen species (ROS) production during the early phase of HD with cuprophan (CUP) is sustained by neutrophils which have bound platelets through P-selectin (CD62P). The evaluation of platelet-neutrophil interactions during dialysis offers the novel aspect of cell-cell interactions as a new parameter for studying the biocompatibility of dialyzer membranes...

The purpose of the study was to bring a contribution to the knowledge of physiology and pathophysiology of the bone mineral heteroionic exchange with respect to sodium ions and metabolic diseases, particularly bone diseases. The instrumental neutron activation analysis was employed to follow the ratio of contents Na/Ca in bone samples from dialyzed patients. A formerly elaborated method for the determination of the Na/Ca ratio in undecalcified bone tissue sections obtained from material embedded in polymethylmethacrylate was used...

Previous experimental and human data suggests a detrimental effect on the course of acute renal failure related to exposure of blood to artificial dialysis membranes of poor biocompatibility. We performed a 2.5-year prospective randomized trial to compare the clinical course of acute renal failure (post-operative ischemic acute tubular necrosis, ATN) in patients receiving a cadaveric renal transplant requiring supportive hemodialysis in the immediate post-transplant setting. Patients were randomized to either a cuprophane or polymethylmethacrylate (PMMA) conventional hollow fiber dialyzer...

High molecular weight (MW) solutes are not removed during conventional hemodialysis (HD), and their accumulation is thought to play a role in some long-term HD complications (anemia, bone and joint pain, neuropathy, itching). The present trial was conducted to evaluate the removal capacity during in vivo HD of a new polymethylmethacrylate (PMMA) membrane (Filtryzer BK-F, 1.3 m2) compared to conventional PMMA (BK-P, 1.6 m2) and to cellulose acetate (CA, 1.3 m2). BK-F dialyzers, with a pore size of 100 A degrees and 62% porosity, are designed to remove high MW substances...