scholarly journals Influences of the priming procedure and saline circulation conditions on polyvinylpyrrolidone in vitro elution from polysulfone membrane dialyzers

2021 ◽  
Vol 28 ◽  
pp. 101140
Author(s):  
Yoshinori Sato ◽  
Hayato Horiuchi ◽  
Shinji Fukasawa ◽  
Shingo Takesawa ◽  
Jun Hirayama
Keyword(s):  
Polysulfone Membrane

Iodixanol is readily eliminated by hemodialysis

1998 ◽  
Vol 39 (4) ◽  
pp. 372-374 ◽  
Author(s):  
K. J. Berg ◽  
B. Rolfsen ◽  
G. Stake
Keyword(s):  
Blood Flow ◽  
Contrast Medium ◽  
Hollow Fiber ◽  
Cellulose Triacetate ◽  
High Flux ◽  
Hollow Fiber Membranes ◽  
Polysulfone Membrane ◽  
Membrane Area ◽  
X Ray

Purpose, Material and Methods, and Results: The dialyzability of the high-molecular X-ray contrast medium iodixanol was examined in an in vitro hemo-dialysis model using two different hollow fiber membranes: one high-flux (polysulfone) membrane and one intermediate-flux (cellulose triacetate) membrane. Blood flow was 200 ml/min and membrane area 1.3 m2. The dialyzer clearance of iodixanol dissolved in a mixture of leukocyte-filtered SAG-M blood and compatible citrate plasma was 134.2±3.6 ml/min for the polysulfone membrane and 113.0±3.6 ml/min for the cellulose triacetate membrane. Conclusion: Iodixanol is readily dialyzed through commercial high-flux membranes.

scholarly journals Quantification of Cleaved β2-Microglobulin in Serum from Patients Undergoing Chronic Hemodialysis

2005 ◽  
Vol 51 (7) ◽  
pp. 1177-1184 ◽  
Author(s):  
Dorthe B Corlin ◽  
Jette W Sen ◽  
Søren Ladefoged ◽  
Grethe Bjerregaard Lund ◽  
Mogens H Nissen ◽  
...  
Keyword(s):  
Biological Fluids ◽  
Chronic Hemodialysis ◽  
Mass Spectrometry Analysis ◽  
Dialysis Patients ◽  
Serum Samples ◽  
Polysulfone Membrane ◽  
Β2 Microglobulin ◽  
And Control

Abstract Background: Patients on chronic hemodialysis are prone to develop amyloid deposits of misfolded β2-microglobulin (β2M) in osteoarticular tissues. β2M with various deletions/truncations and chemical modifications has been found together with structurally intact β2M in extracts of β2M amyloid fibrils. The state of the circulating population of β2M molecules has not been characterized previously with high-resolution methods. Methods: We used immunoaffinity–liquid chromatography–mass spectrometry analysis of serum samples to examine whether structurally modified β2M is generated in the circulation. In addition, we developed an immunoassay for the quantification of a cleaved β2M variant in biological fluids based on novel monoclonal antibodies and applied this assay to patient and control sera. Results: A specific alteration compatible with the generation of lysine-58–cleaved and truncated β2M (ΔK58-β2M) was found in the sera of many (20%–40%) dialysis patients but not in control sera or sera from patients with cerebral amyloidosis (Alzheimer disease). Applied to patient sera, specific immunoassays revealed that dialysis, as expected, significantly lowered the total β2M concentration, but the concentrations of ΔK58-β2M remained unchanged after dialysis. The results also show that patients dialyzed with less biocompatible membranes have higher serum concentrations of cleaved β2M (mean, 8.5, 1.8, and 0.7 mg/L in cuprophane membrane-dialyzed, polysulfone membrane-dialyzed, and control sera, respectively). Conclusions: This study for the first time demonstrates and assigns the structure of a specific β2M variant in sera from dialysis patients. Because this variant is conformationally unstable in vitro, it may be involved in in vivo amyloidogenesis.

scholarly journals Prediction of In Vivo Atenolol Removal by High-Permeability Hemodialysis Based on an In Vitro Model

2013 ◽  
Vol 16 (5) ◽  
pp. 657 ◽  
Author(s):  
Kahina Daheb ◽  
Jean-Philippe Lecours ◽  
Mark L. Lipman ◽  
Patrice Hildgen ◽  
Julie J. Roy
Keyword(s):  
Curve Fitting ◽  
Prediction Interval ◽  
Sample Collection ◽  
High Permeability ◽  
Polysulfone Membrane ◽  
Oral Tablet ◽  
Drug Concentrations ◽  
Elimination Curve

Purpose. In order to update our data on drug dialyzability using the high-permeability dialysis membranes, atenolol elimination by an in vitro dialysis model was compared to that observed in six patients during high-permeability hemodialysis (HD), and the predictive value of the model was evaluated. Methods. Atenolol clearance was evaluated in six patients undergoing chronic HD. They were considered as eligible candidates if they were between 18 and 80 years of age, had a body mass index between 19 and 30 kg/m2, underwent HD and were taking atenolol on a regular basis in oral tablet form for at least 1 month before the study started. Atenolol clearance was also evaluated in three in vitro dialysis sessions with high-permeability polysulfone membrane. Atenolol was dissolved in 6 L of Krebs-Henseleit buffer with bovine serum albumin. Dialysis parameters were set to mirror as much as possible the patients’ parameters (flow rate: 300 mL/min, dialyzate flow: 500 mL/min). After sample collection, drug concentrations were measured with high performance liquid chromatography. The comparison between in vivo and in vitro atenolol elimination kinetics was performed by drawing the curve fittings of concentrations vs. time on SigmaPlot 12, and adding a 95% prediction interval to each elimination curve fitting. Results. Mean dialysis clearance of atenolol in vitro and in vivo was 198 ± 4 and 235 ± 53 mL/min, respectively. Atenolol was significantly removed within the study time period in both in vitro and in vivo experiments. By the end of in vitro dialysis, atenolol remaining in the drug reservoir was less than 2% of initial arterial concentration. Conclusion. Our study has indicated that atenolol is almost entirely cleared during high-permeability hemodialysis. Furthermore, the in vitro prediction interval of the drug elimination curve fitting could forecast its in vivo elimination especially at the end of dialysis. This article is open to POST-PUBLICATION REVIEW. Registered readers (see “For Readers”) may comment by clicking on ABSTRACT on the issue’s contents page.

scholarly journals Adsorption of vancomycin, gentamycin, ciprofloxacin and tygecycline on the filters in continuous renal replacement therapy circuits: in full blood in vitro study

2020 ◽  
Author(s):  
Dariusz Onichimowski ◽  
Krzysztof Nosek ◽  
Hubert Ziółkowski ◽  
Jerzy Jaroszewski ◽  
Aleksandra Pawlos ◽  
...  
Keyword(s):  
Renal Replacement Therapy ◽  
In Vitro Study ◽  
Blood Pump ◽  
Initial Value ◽  
Polysulfone Membrane ◽  
Blood Samples ◽  
Porcine Blood ◽  
Polyacrylonitrile Membrane

Abstract The aim of this study was to assess the in vitro adsorption of antibiotics: vancomycin, gentamicin, ciprofloxacin and tigecycline on both polyethyleneimine-treated polyacrylonitrile membrane of AN69ST filter and polysulfone membrane of AV1000 filter using porcine blood as a model close to in vivo conditions. The porcine blood with antibiotic dissolved in it was pumped into hemofiltration circuit (with AN69ST or AV1000 filter), ultrafiltration fluid was continuously returned to the reservoir containing blood with antibiotic. Blood samples to determine antibiotic concentrations were taken at minutes 0, 5, 15, 30, 45, 60, 90 and 120 from the pre- blood pump of the hemofiltration circuit. To assess possible spontaneous degradation of the drug in the solution there was an additional reservoir prepared for each antibiotic, containing blood with the drug, which was not connected to the circuit. In the case of vancomycin, ciprofloxacine and tigecycline, a statistically significant decrease in the drug concentration in the hemofiltration circuit in comparison to initial value as well as to the concentrations in the control blood was observed, both for polyacrylonitrile and plolysulfone membrane. In the case of gentamicin, significant adsorption was noted only on polyacrylonitrile membrane. Our studies demonstrated that in full blood adsorption of antibiotics may be big enough to be of clinical significance. In particular in the case of polyacrylonitrile membrane.

Technical and Clinical Evaluation of a New Asymmetric Polysulfone Membrane (Biosulfane®)

1993 ◽  
Vol 16 (8) ◽  
pp. 573-584 ◽  
Author(s):  
C. Ronco ◽  
A. Brendolan ◽  
C. Crepaldi ◽  
M.C. Bettini ◽  
M. Scabardi ◽  
...  
Keyword(s):  
Wall Thickness ◽  
Hydraulic Permeability ◽  
Dialysis Session ◽  
High Flux ◽  
Polysulfone Membrane ◽  
Diffusive Permeability ◽  
Wide Range ◽  
Beta 2 ◽  
Beta 2 Microglobulin

First generation asymmetric polysulfone membranes had high hydraulic permeability (kf=40 ml/h/mmHg/sqm) but a low diffusive permeability due to the hydrophobic nature and wall thickness of 75–100 microns. We have tested a new polysulfone membrane with a wall thickness of 40 microns in a series of in vitro and in vivo dialysis session experiments. The new “Biosulfane®” membrane presented a Kf of 45.8 with constant performance up to 240 mins. The koA was 760 and the clearance value at 350 ml/min of Qb in hemodiafiltration was 255 ml/min for urea, 210 for creatinine, 225 for phosphate, 76 for inulin. In high flux dialysis the clearances were similar except for inulin which was 32% lower due to the lower convection amount. Beta-2 microglobulin clearance was 22 ml/min in high flux dialysis and 37 in hemodiafiltration. Solute sieving coefficients were close to 1 for the majority of the studied solutes in a wide range of molecular weights and slight variations were observed for charged solutes due to Donnan's effect. The sieving for Inulin was 0.96 while that for Beta-2 microglobulin was not measurable due to a large molecule adsorption on the inner structure of the fibres. The good performances of this membrane are probably due to reduced wall thickness and a consequent improvement in diffusive permeability to small size solutes.

Ultrastructural Investigations of the Contractile Filaments of Amoebae

1974 ◽  
Vol 32 ◽  
pp. 188-189
Author(s):  
P.L. Moore
Keyword(s):  
Cytoplasmic Streaming ◽  
Three Dimensional ◽  
Freeze Fracture ◽  
Amoeboid Movement ◽  
Different Types ◽  
Chemical Conditions ◽  
Complete Interpretation

Previous freeze fracture results on the intact giant, amoeba Chaos carolinensis indicated the presence of a fibrillar arrangement of filaments within the cytoplasm. A complete interpretation of the three dimensional ultrastructure of these structures, and their possible role in amoeboid movement was not possible, since comparable results could not be obtained with conventional fixation of intact amoebae. Progress in interpreting the freeze fracture images of amoebae required a more thorough understanding of the different types of filaments present in amoebae, and of the ways in which they could be organized while remaining functional.The recent development of a calcium sensitive, demembranated, amoeboid model of Chaos carolinensis has made it possible to achieve a better understanding of such functional arrangements of amoeboid filaments. In these models the motility of demembranated cytoplasm can be controlled in vitro, and the chemical conditions necessary for contractility, and cytoplasmic streaming can be investigated. It is clear from these studies that “fibrils” exist in amoeboid models, and that they are capable of contracting along their length under conditions similar to those which cause contraction in vertebrate muscles.

In Vitro Induction of Crystals of MT Protein by Vinblastine-Colcemid in Mouse Spermatids

1974 ◽  
Vol 32 ◽  
pp. 132-133
Author(s):  
John J. Wolosewick ◽  
John H. D. Bryan
Keyword(s):  
Endoplasmic Reticulum ◽  
Smooth Endoplasmic Reticulum ◽  
Nuclear Ring ◽  
Rough Er ◽  
Distal Direction ◽  
In Vitro Induction

Early in spermiogenesis the manchette is rapidly assembled in a distal direction from the nuclear-ring-densities. The association of vesicles of smooth endoplasmic reticulum (SER) and the manchette microtubules (MTS) has been reported. In the mouse, osmophilic densities at the distal ends of the manchette are the organizing centers (MTOCS), and are associated with the SER. Rapid MT assembly and the lack of rough ER suggests that there is an existing pool of MT protein. Colcemid potentiates the reaction of vinblastine with tubulin and was used in this investigation to detect this protein.

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