Novel Extracorporeal Dialysis Circuit to Improve the Removal Efficiency of High and Middle Molecular Weight Toxins

2018 ◽  
Vol 43 (3) ◽  
pp. 254-260 ◽  
Author(s):  
Ali Poorkhali ◽  
Davood Bizari ◽  
Hasan Farrokhzad
Keyword(s):  
Molecular Weight ◽  
Removal Efficiency ◽  
Extracorporeal Dialysis

P1100IMPACT OF THE RELATIONSHIP BETWEEN LOW MOLECULAR WEIGHT PROTEINS REMOVAL EFFICIENCIES AND THE VOLUME OF ALBUMIN LEAKAGE IN HEMODIAFILTRATION THERAPY

2020 ◽  
Vol 35 (Supplement_3) ◽  
Author(s):  
Kenji Sakurai ◽  
Takeshi Saito ◽  
Hiromi Hosoya ◽  
Yoshitaka Kurihara ◽  
Kaori Kurosawa ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Removal Efficiency ◽  
High Efficiency ◽  
Low Molecular Weight ◽  
Efficient Removal ◽  
On Line ◽  
Stokes Radius ◽  
Removal Efficiencies ◽  
The Relationship ◽  
Low Molecular Weight Proteins

Abstract Background and Aims The purpose of hemodiafiltration (HDF) is to remove small- to large molecular weight solutes in order to prevent and treat complications and to improve the prognosis of dialysis patients. Especially, larger low molecular weight proteins (LMWPs) must be removed efficiently. β2-microglobulin (MG) (molecular weight [MW], 11.8 kDa: Stokes radius, 15.6A), is considered as an important marker of dialysis efficiency. However, MW of β2-MG is too small as a marker in HDF. Conversely, α1-MG (MW, 33 kDa: Stokes radius, 28.4A) is the most appropriate marker for evaluation of solute removal efficiency of HDF because of the following reasons: (1) optical molecular size; (2) not very low physiological blood concentration; (3) stable production rate; (4) removal by convection; and (5) accumulation in ESRD. Efficient removal of α1-MG without losing albumin (Alb) (MW,66 kDa: Stokes radius, 35.5A) is impossible even by HDF. In this study, we investigated the relationship between LMWP removal efficiencies and the volume of Alb leakage by analyzing the results of patients undergoing HDF. And we also evaluated the trend of the serum levels of patients who had received high-efficiency HDF for more than three years Method Eighty-seven patients who had received HDF in 2018–2019 were included. The results of HDF (a total of 435 sessions) were analyzed (blood flow rate, 261.5±28.5 mL/min; replacement fluid volume, 48.7 L/s pre-dilution on-line HDF and 14.2 L/s post-dilution on-line HDF). The removal efficiencies of β2-MG, prolactin (PRL), and α1-MG, and the volume of Alb leakage were examined. In addition, the relationship between the removal efficiency of each solute and the volume of Alb leakage was investigated. Changes in serum Alb level were analyzed in 13 patients who continued to receive high-efficiency HDF (the removal rate of α1-MG was 30% or more) for more than three years. Results Analysis of the results (mean ± SD) obtained from a total of 435 sessions (87 patients) showed that the removal rates of β2-MG, PRL, and α1-MG were 80.7 ± 4.5%, 75.8±9.4 and 33.8 ± 9.4%, respectively, and the Alb leakage was 3.9 ± 1.8 g/s. The equations of the approximate curve between Alb leakage and β2-MG, PRL, and α1-MG removal rates were expressed as follows: ï½™= 1.4197ln(x) + 78.972 (R2 = 0.0426), y = 9.7185ln(x) + 64.134 (R2 =0.4632), and ï½™™= 11.225ln(x) + 20.282 (R2 = 0.6191), respectively. These results indicate that the dynamics between Alb leakage and α1-MG removal are very similar. That is, although the molecular weight of Alb is twice as that of α1-MG, the difference in their Stokes radius is 20%; therefore, separate removal of Alb and α1-MG is impossible. The mean serum Alb level in 13 patients who received high-efficiency HDF for 3 years or longer was 3.59 ± 0.23 g/dL in January 2017 and 3.69 ± 0.28 g/dL in December 2019, revealing no changes. Conclusion The efficient removal of larger LMWPs leads to the leakage of Alb. However, an Alb leakage of 3 to 6 g/s has little influence on the serum Alb level of patients. Thus, α1-MG is the most appropriate marker of the solute removal efficiency of HDF.

scholarly journals Suitability of α1-microglobulin reduction rate as a biomarker of removal efficiency of online hemodiafiltration: a retrospective cohort study

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Kenji Sakurai ◽  
Hiromi Hosoya ◽  
Yoshitaka Kurihara ◽  
Takeshi Saito
Keyword(s):  
Molecular Weight ◽  
Cohort Study ◽  
Removal Efficiency ◽  
Retrospective Cohort ◽  
Reduction Rate ◽  
Low Molecular Weight ◽  
Albumin Leakage ◽  
Maintenance Dialysis ◽  
The Relationship ◽  
Low Molecular Weight Proteins

Abstract Background Online hemodiafiltration (OL-HDF), whether in pre-dilution OL-HDF (pre-HDF) or post-dilution OL-HDF (post-HDF), is conducted to efficiently remove low molecular weight proteins from the blood of patients requiring dialysis. β2-microglobulin (β2-MG) and α1-microglobulin (α1-MG) are used as biomarkers to evaluate removal efficiency of OL-HDF. We aimed to evaluate the relationship between β2-MG and α1-MG reduction rates and the amount of albumin leakage. Furthermore, we statistically analyzed the relationship between the α1-MG reduction rate and α1-MG removal amount, and its suitability as a biomarker for evaluating the removal efficiency of OL-HDF. Methods We collected the results of regularly conducted routine evaluations to assess the efficiency of OL-HDF from cases of patients undergoing maintenance dialysis at our clinic from 2018 to 2019. Data on was collected on both pre-HDF and post-HDF sessions. β2-MG and α1-MG reduction rates were analyzed. Regression analysis on reduction rates showed a significant correlation between the α1-MG reduction rate and the α1-MG removal amount. Results We conducted 435 tests on OL-HDF efficiency in 87 cases undergoing maintenance dialysis at our clinic in 2018 and 2019. There were 80.7 ± 4.5% for the β2-MG reduction rate, 33.8 ± 9.4% for the α1-MG reduction rate, and 3.9 ± 1.8 g/s for the amount of albumin leakage. There was no correlation between the β2-MG reduction rate and the α1-MG reduction rate, or between the amount of albumin leakage and β2-MG reduction rate. Conclusion α1-MG reduction rate was found to correlate with its removal amount, demonstrating its suitability as a biomarker for evaluating the removal efficiency of OL-HDF. Trial registration Retrospectively registered.

P1058COMPARISON OF THE REMOVAL EFFICIENCY AND THE BIOCOPATIBILITY BETWEEN PRE- AND POST-DILUTION ON-LINE HEMODIAFILTRATION

2020 ◽  
Vol 35 (Supplement_3) ◽  
Author(s):  
Kenji Sakurai ◽  
Takeshi Saito ◽  
Hiromi Hosoya ◽  
Yoshitaka Kurihara ◽  
Fumi Yamauchi ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Removal Efficiency ◽  
Flow Rate ◽  
High Performance ◽  
Removal Rate ◽  
Replacement Fluid ◽  
Tnf Α ◽  
Dialysate Flow Rate ◽  
Before And After ◽  
On Line

Abstract Background and Aims On-line HDF (OL-HDF) performed in Japan is characterized by the fact that pre-dilution OL-HDF (pre-HDF) accounts for 95% of the cases. In Europe, post-dilution OL-HDF (post-HDF) is the mainstream mode, and particularly high-volume post-HDF is reportedly associated with a favorable prognosis in patients. Last year, we reported favorable biocompatibility and removal efficiency of low-volume post-HDF using high-performance hemodiafilters. Here, we performed pre-HDF and post-HDF for 4 weeks each under the same conditions in the previous study and compared the removal efficiency and the biocompatibility. Method Nine stable dialysis patients who had received pre-HDF for at least 6 months (age, 60.8±15.4 years; dry weight, 54.5±9.5 kg) were included in this study. Fineflux-210 Seco (asymmetric triacetate membrane, NIPRO) was used as a hemodiafilter. Post-HDF (replacement fluid rate, 12 L/session) was performed in the first session and pre-HDF (replacement fluid rate, 60 L/session) in the second, each lasting 4 weeks. Each study parameter was evaluated on the last day of each session. In either session, HDF was performed at a blood flow rate of 250 mL/min and a total dialysate flow rate of 500 mL/min. Each HDF cycle lasted 4 h. The removal efficiency was evaluated in terms of Kt/V, as well as the removal rates and removal volumes of urea, creatinine, β2-microglobulin (MG), and α1-MG. Biocompatibility was evaluated in terms of the rates of changes in the levels of CRP, interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), pentraxin-3 (PTX3), and intercellular adhesion molecule-1 (ICAM-1) before and after dialysis. Changes in the levels of CD62P during dialysis were also examined. Paired t-test was used for statistical analysis. Results Removal efficiency results: The removal efficiency for small molecular weight solutes was significantly higher in post-HDF. The removal rate (%) and removal volume (g/session) of β2-MG were 81.4±3.6 and 0.224±0.051 in post-HDF and 80.7±3.3 and 0.218±0.029 in pre-HDF, respectively. The removal rate (%) and removal volume (g/session) of α1-MG were 37.0±4.0 and 0.151±0.024 in post-HDF and 33.3±4.1 and 0.133±0.026 in pre-HDF, respectively. The amount of albumin leakage (g/session) was 3.7±0.6 in post-HDF and 3.1±0.7 in pre-HDF, indicating a significant difference. Biocompatibility results: There were no significant differences between the two modes in the rates of changes in the levels of CRP, PTX3, IL-6, TNF-α, or ICAM-1 before and after treatment. The rate of expression of CD62P was also not significantly different. Conclusion Under the present conditions using high-performance filters, post-HDF and pre-HDF demonstrated favorable removal efficiency for both small and large molecular weight solutes, and the biocompatibility was also favorable, indicating no significant differences between the two modes.

scholarly journals The Effect of Cellular Organic Matter Produced by Cyanobacteria Microcystis Aeruginosa on Water Purification

2009 ◽  
Vol 57 (2) ◽  
pp. 121-129 ◽  
Author(s):  
Martin Pivokonský ◽  
Lenka Pivokonská ◽  
Jitka Bäumeltová ◽  
Petra Bubáková
Keyword(s):  
Molecular Weight ◽  
Organic Matter ◽  
Microcystis Aeruginosa ◽  
Removal Efficiency ◽  
Water Purification ◽  
The Other ◽  
Raw Water ◽  
Ferric Sulphate ◽  
Reaction Conditions ◽  
Aluminium Sulphate

The Effect of Cellular Organic Matter Produced by Cyanobacteria Microcystis Aeruginosa on Water PurificationThe aim of this paper is to investigate the influence of COM (Cellular Organic Matter) produced byMicrocystis aeruginosaon the process of water purification by destabilisation and subsequent aggregation of the impurity particles. The research was carried out with a raw water into which COM was added. The removal efficiency of the most significant components of COM, i.e. polysaccharides and proteins, was investigated. It was found that the removal efficiency of polysaccharides and proteins was dependent on the reaction conditions (pH, type of destabilisation reagent and its dosage). The removal efficiency of COM was relatively low. It was about 46% and 41% using ferric sulphate and aluminium sulphate aggregation, respectively. In comparison to the other organic components of COM, mainly polysaccharides, the proteins are removed with a higher efficiency. The GPC analyses of the residual COM showed that the proteins of higher molecular weight were aggregated with a higher efficiency.

Polyacrylonitrile homogeneous blend hollow fiber membrane with stable structure as a substrate to support Fe/Mn oxide and its enhanced capability to purify dye wastewater

2020 ◽  
Vol 40 (6) ◽  
pp. 469-479
Author(s):  
Zhifen Hao ◽  
Naiku Xu ◽  
Yan Feng ◽  
Yu Chen ◽  
Changfa Xiao ◽  
...  
Keyword(s):  
Molecular Weight ◽  
High Molecular Weight ◽  
Removal Efficiency ◽  
Hollow Fiber ◽  
Hollow Fiber Membrane ◽  
Low Molecular Weight ◽  
Dye Wastewater ◽  
Fiber Membrane ◽  
Mn Oxide ◽  
Operation Pressure

AbstractBlending different molecular weight polyacrylonitrile (PAN) was adopted to solve the shrinkage problem of high molecular weight PAN hollow fiber membrane, to enhance the application performance of low molecular weight PAN membrane, and to adjust the porosity, pore size distribution, and hydrophilicity of the end product. The structurally-optimized membrane was chosen as a substrate to support Fe/Mn oxides and then used as a reactor to remove dyes from their solutions in the presence of H2O2. The results showed that the flux of methylene blue (MB) aqueous solution was 83.7 L/m2 h for the PAN homogeneous blend membrane, much higher than 29.1 L/m2 h of high molecular weight PAN membrane; MB removal efficiency was 97.3%, higher than 62.3% of low molecular weight PAN membrane, and it could be reused 25 times to remove dyes from their solutions without any loss in removal efficiency. The membrane was also found to have the application advantages of decreasing H2O2 dosage, reducing operation pressure, and raising MB removal efficiency compared with other membranes reported in the pieces of literature. Therefore, we were confident that the hollow fiber membrane fabricated by us would exhibit great application potential in the field of decontaminating dye wastewater.

Evaluation of the dark field method for large association of spread DNA

1978 ◽  
Vol 36 (2) ◽  
pp. 190-191
Author(s):  
Douglas C. Barker
Keyword(s):  
Electron Microscopy ◽  
Molecular Weight ◽  
Mitochondrial Dna ◽  
Extraction Method ◽  
Field Method ◽  
Dark Field ◽  
Kinetoplast Dna ◽  
Field Electron ◽  
Field Electron Microscopy ◽  
Dark Field Electron

A number of satisfactory methods are available for the electron microscopy of nicleic acids. These methods concentrated on fragments of nuclear, viral and mitochondrial DNA less than 50 megadaltons, on denaturation and heteroduplex mapping (Davies et al 1971) or on the interaction between proteins and DNA (Brack and Delain 1975). Less attention has been paid to the experimental criteria necessary for spreading and visualisation by dark field electron microscopy of large intact issociations of DNA. This communication will report on those criteria in relation to the ultrastructure of the (approx. 1 x 10-14g) DNA component of the kinetoplast from Trypanosomes. An extraction method has been developed to eliminate native endonucleases and nuclear contamination and to isolate the kinetoplast DNA (KDNA) as a compact network of high molecular weight. In collaboration with Dr. Ch. Brack (Basel [nstitute of Immunology), we studied the conditions necessary to prepare this KDNA Tor dark field electron microscopy using the microdrop spreading technique.

Introduction

1978 ◽  
Vol 36 (3) ◽  
pp. 543-544
Author(s):  
W. Bernard
Keyword(s):  
Molecular Weight ◽  
Electron Microscope ◽  
Nucleic Acid ◽  
Gene Mapping ◽  
Molecular Genetics ◽  
Cell Biology ◽  
Gene Activity ◽  
Close Connection ◽  
Basic Information ◽  
Simple Systems

In comparison to many other fields of ultrastructural research in Cell Biology, the successful exploration of genes and gene activity with the electron microscope in higher organisms is a late conquest. Nucleic acid molecules of Prokaryotes could be successfully visualized already since the early sixties, thanks to the Kleinschmidt spreading technique - and much basic information was obtained concerning the shape, length, molecular weight of viral, mitochondrial and chloroplast nucleic acid. Later, additonal methods revealed denaturation profiles, distinction between single and double strandedness and the use of heteroduplexes-led to gene mapping of relatively simple systems carried out in close connection with other methods of molecular genetics.

The External Shape of Human γ GI Immunoglobulin from Crystal Sections

1971 ◽  
Vol 29 ◽  
pp. 428-429
Author(s):  
L. W. Labaw
Keyword(s):  
Molecular Weight ◽  
Sodium Phosphate ◽  
Osmium Tetroxide ◽  
Unit Cell ◽  
Monoclinic Space Group ◽  
X Ray ◽  
Large Molecular Weight ◽  
Cell Dimensions ◽  
Unit Cell Dimensions ◽  
Crystallographic Axes

Crystals of a human γGl immunoglobulin have the external morphology of diamond shaped prisms. X-ray studies have shown them to be monoclinic, space group C2, with 2 molecules per unit cell. The unit cell dimensions are a = 194.1, b = 91.7, c = 51.6Å, 8 = 102°. The relatively large molecular weight of 151,000 and these unit cell dimensions made this a promising crystal to study in the EM.Crystals similar to those used in the x-ray studies were fixed at 5°C for three weeks in a solution of mother liquor containing 5 x 10-5M sodium phosphate, pH 7.0, and 0.03% glutaraldehyde. They were postfixed with 1% osmium tetroxide for 15 min. and embedded in Maraglas the usual way. Sections were cut perpendicular to the three crystallographic axes. Such a section cut with its plane perpendicular to the z direction is shown in Fig. 1.This projection of the crystal in the z direction shows periodicities in at least four different directions but these are only seen clearly by sighting obliquely along the micrograph.

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