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Volume 14, Issue 1
Displaying 1-12 of 12 articles from this issue
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Isao EBIHARA, Hikaru KOIDE1989 Volume 14 Issue 1 Pages 2-10
Published: January 01, 1989
Released on J-STAGE: March 04, 2011
JOURNAL FREE ACCESSThe glomerular basement membrane (GBM) is thin extracellular matrices which separate the visceral epithelium of the glomerulus from the capillary endothelium and serves as a filter for blood molecules. GBMs are composed of type IV collagen, laminin, heparan sulfate proteoglycan, entactin/nidogen, fibronectin and other minor glycoproteins which are not characterized. Recent technological advances have been made in determing the protein and gene structure of these proteins. This article will review the current informations of GBM constituents, structure and function.View full abstractDownload PDF (1585K) -
Yoshimasa ORITA, Toshiro TAKAMA, Yoshihiro FUJIWARA1989 Volume 14 Issue 1 Pages 11-20
Published: January 01, 1989
Released on J-STAGE: March 04, 2011
JOURNAL FREE ACCESSMesangial cells, which were discovered by Zimmermann, occupy the axialregion of renal glomerular network, and have some functions such as modulation of glomerular filtration rate (GFR), macromolecule uptake and production of several substances. Vasoactive agents, angiotensin II, vasopressin, platelet-derived growth factor (PDGF) and platelet-activating factor (PAF), stimulate mesangial cell contraction, which decreases GFR through the reduction of ultrafiltration coefficient of single nephron GFR. These vasoactive agents activate phosphoinositide (PI) cycle, and produce diacylglycerol and inositol-phosphates in mesangial cells. Vasorelaxant agents, dopamine and atrial natriuretic peptide (A NP), do not activate PI cycle. Dopamine produces cAMP and ANP synthesizes cGMP. These vasorelaxant agents suppress mesangial cell contraction and decrease in GFR induced by vasoactive agents.
Mesangial cell proliferation is a common feature of various forms of glomerulonephritis. It is very important to clarify growth factors for mesangial cells and their mechanism of mesangial cell proliferation. These vasoactive agents stimulate mesangial cell proliferation, on the other hand, vasorelaxant agents inhibit it. Vasoactive agents may stimulate not only mesangial cell contraction but also mesangial cell proliferation probably through activation of PI cycle, but vasorelaxant agents may suppress activation of PI cycle enhanced by vasoactive agents through cAMP or cGMP.View full abstractDownload PDF (1632K) -
Naoki Yoshiyama, Fumiaki Marumo1989 Volume 14 Issue 1 Pages 21-30
Published: January 01, 1989
Released on J-STAGE: March 04, 2011
JOURNAL FREE ACCESSRecent advance of materials and design for dialyser membrane made possible to achieve high dialysis efficacy and high flux. The purpose of dialysis membrane now and in the future is to refine blood biocompatibility and to get the character to remove the special substances from the blood of uremic patients. Because of the difficulties to achieve the complete biocompatibility by artificial polymers now used, it is important for us to change the idea for invention of new dialyser material of the next generation.View full abstractDownload PDF (1601K) -
Kiyotaka Sakai1989 Volume 14 Issue 1 Pages 31-44
Published: January 01, 1989
Released on J-STAGE: March 04, 2011
JOURNAL FREE ACCESSVarious materials are presently available for hollow fiber dialysis membranes which satisfy technical and medical requirements such as high permeability to uremic toxins and water, biocompatibility, resistance to sterilization, and high mechanical strength. New dialysis membranes with high permeability to β2-microglobulin and with biocompatibility leading to low complement activation have been developed for more optimal hemodialysis. Data on structure and permeability are then required to prepare the new dialysis membranes. Much attention should be paid also to the geometry of hollow fiber dialysis membranes available for chronic renal failure patients with elevated hematocrits caused by the administration of erythropoietin.View full abstractDownload PDF (1614K) -
Hajime Miyama, Hirotoshi Manago, Yoshio Nosaka, Nobuyuki Fujii, Hirosh ...1989 Volume 14 Issue 1 Pages 45-49
Published: January 01, 1989
Released on J-STAGE: March 04, 2011
JOURNAL FREE ACCESSPolyacrylonitrile graft polymer with side chains of dimethylaminoethyl methacrylate was photochemically synthesized. The positively charged ultrafiltration membranes modeled after glomerular capillary wall were made by casting the graft polymer. Permeation of albumin and γ-globulin through the membranes was measured by using a buffered saline solution containing both proteins. The experiment yielded the following result that permeation of albumin was greater than that of γ-globulin in solutions at pH higher than the isoelectric point of albumin. Taking account of the molecular weight cut-off characteristic of the positively charged membranes, it was considered that the separation of the proteins was due to the interaction between the charge of the proteins and that of the membrane.View full abstractDownload PDF (534K) -
K. Ogasawara, F. Kushiya, K. Sakai1989 Volume 14 Issue 1 Pages 50-53
Published: January 01, 1989
Released on J-STAGE: March 04, 2011
JOURNAL FREE ACCESSThe present study elucidates filtration characteristics of rotating filters for plasma separation composed of flat Nylon membranes. No drop in filtrate flux with transmembrane pressure is observed with Nylon membranes. The red blood cell polarization model accounts for filtration characteristics of rotating filters.View full abstractDownload PDF (419K) -
Kinzi Asaka1989 Volume 14 Issue 1 Pages 54-63
Published: January 01, 1989
Released on J-STAGE: March 04, 2011
JOURNAL FREE ACCESSDielectric measurements were carried out for cellulose acetate (CA) membranes in different degrees of acetyl substitution (DS) in aqueous salt solution. Relative permittivities and conductivities of the membranes immersed in NaCl aqueous solutions were determined by use of a theory on the dielectric relaxation of the interfacial polarization.
The relative permittivities of the CA membranes were directly proportional to the water contents of the membranes.
The salt permeabilities of the membranes estimated from the conductivities were in agreement with the results of the measurements of the salt permeabilities presented by other authors.
The relation between the conductivity and the NaCl concentration of the external aqueous solution showed that the CA membranes were weakly charged. The value of the effective fixed charge density estimated from the dielectric data was 15 m equiv./1, which was in conformity with the results of the membrane potential measurements by other authors.View full abstractDownload PDF (955K) -
Performance of Commercial Ultrafiltration Membranes and Effects of Protain AdsorptionH. Yanagishita, T. Nakane, J. Aihara, S. Takatsu, H. Yoshitome1989 Volume 14 Issue 1 Pages 64-70
Published: January 01, 1989
Released on J-STAGE: March 04, 2011
JOURNAL FREE ACCESSThe performance of commercially available ultrafiltration membranes was examined at the same condition using the aqueous solutions of polyethyleneglycohols (PEG). The results showed that the pure water flux of the hydrophilic membrane was more stable than that of the hydrophobic ones, and membrane compaction effects were especially observed in the membrane made from the polymer with the flexible vinyl-chain. The molecular weight cut-off of PEG was not sharp in all membrane tested, and they extended over two orders of magnitude in most cases.
The influences of membrane materials were also evaluated from the change of pure water flux in the membranes which were soaked in the solutions containing the albumin (from egg) of 1, 000 ppm. The solutions were prepared at different conditions such as pH and ionic strength. The results indicated that the water flux in the hydrophilic membrane was less affected by the adsorption of the albumin than in the hydrophobic ones. And, it was also shown in the membrane made from the same material that the water flux of the membrane with high separation performance was more stable than that of the membranes with lower ones.View full abstractDownload PDF (703K) -
Masayasu TASAKA, Nobuhiro MIYAHARA1989 Volume 14 Issue 1 Pages 71-76
Published: January 01, 1989
Released on J-STAGE: March 04, 2011
JOURNAL FREE ACCESSThe dependence of streaming potential on time was measured by applying a pressure difference across a glass filter membrane, a cellulose acetate membrane, a collodion-polystyrenesulfonic acid membrane, a collodion-polyacrylic acid membrane, and a collodion-polyacrylic acid partially complexed with Fe (III) -ions membrane. The streaming potential reached immediately a constant value after pressure difference was applied across the membrane, if the membrane was made of substances having stiff structure. However, the absolute value of the streaming potential across the membrane made of soft structure increased slowly with time and a long time was required to reach a steady state. Therefore, the properties of membranes can be characterized by analyzing the dependence of streaming potential on time.View full abstractDownload PDF (633K) -
Sei-ichi Manabe, Takashi Tsurumi, Gen Ishikawa, Masuo Satani, Takashi ...1989 Volume 14 Issue 1 Pages 77-83
Published: January 01, 1989
Released on J-STAGE: March 04, 2011
JOURNAL FREE ACCESSWe intended to show filtration characteristics of BMM for solutions containing HIV and to clarify membrane separation mechanism for HIV particles and to demonstrate an ideal membrane for HIV removal. The hollow fibers with mean pore sizes (2 γf) ranging from 10 nm to 105 nm were prepared from the cuprammonium solution of cellulose through the micro-phase separation method. The particle of HIV was obtained from cell-free culture supernatant of MOLT-4/HIV cells. Pore characteristics and distribution of HIV in BMM were evaluated through electronmicroscopy. The concentration of HIV was evaluated through the plaque forming method. Filtration experiments were carried out at transmembrane pressures ranging from 20 mmHg to 1000 mmHg and filtration volumes of less than 55 l/m2. All filtrate didn't have HIV in detectable level. The electronmicroscopy revealed that BMM had a multi-layer structure and HIV was caught in BMM by the multi-step filtration mechanism. The pore size distribution of each layer can be designed so as to get high recovery of protein during HIV free filtration.View full abstractDownload PDF (834K) -
Hiroyuki Ohshima, Tamotsu Kondo1989 Volume 14 Issue 1 Pages 84-87
Published: January 01, 1989
Released on J-STAGE: March 04, 2011
JOURNAL FREE ACCESSPotential distribution across a charged membrane of a spherical shell of radius a, which serves as a model for a cell, is calculated on the basis of a membrane model that the membrane core is covered by an ion-penetrable surface charge layer of thickness d in which the membrane-fixed charges are distributed at a uniform density N. Curvature effects are found to become appreciable when ka_??_10 (k=Debye-Hiickel parameter). When kd_??_5, the potential far inside the surface charge layer is almost equal to the Donnan potential. When it ka>>1 and kd>>1, the surface potential (the potential at the boundary between the outer surface charge layer and the surrounding solution) becomes half the Donnan potential. The surface potential becomes identical to the Gouy-Chapman double layer potential as d→0 with the product Nd kept constant.View full abstractDownload PDF (378K) -
Correction of measured retention using mass transfer coefficientHaruhiko Ohya, Chikako Hashimoto, Akihito Haio, Youichi Negishi, Kanji ...1989 Volume 14 Issue 1 Pages 88-97
Published: January 01, 1989
Released on J-STAGE: March 04, 2011
JOURNAL FREE ACCESSFor the purpose to standardize method to determine molecular weight (Mw) cutoff characteristics of ultrafiltration (UF) membrane using aqueous polyethylene glycol (PEG) solutions, the effect of operating conditions of linear velocity and transmembran pressure (TMP) on PEG retention was investigated. Thin channel type cells were made, of which dimensions were width 4 [min], length 79-118 [mm], depth 0.7-1.4 [mm] and effective membrane area 3.48-4.72 [cm2], Based on velocity variation method, mass transfer coefficients on the surface of membrane (k) were calculated, which agree well with that based on boundary layer theory when Mw of PEG is less than 3 [kg·mol-1] and with that obtained by Leveque's equation when more than 7.5 [kg·mol-1]. Using the calculated k, intrinsic retention of membrane was obtained, which is increasing with the increase of TMP, but which is independent on linear velocity on the surface of membrane.
NTU-3150 which is made of polysulfone and supplied from Nitto DENKO Co. has intrinsic retention of 95% at Mw 15 [kg·mol-1] at 20kPa of TMP. DUS-40 which is made of polyethersulfone and supplied from Daicel Chemical Ind. Ltd. has intrinsic retention of 95% at Mw 10 [kg·mol-1] at 35 kPa of TMP-and 20 [kg·mol-1] at 10 kPa. With the increase of TMP, curves of intrinsic retention vs Mw shift to the left and becomes upright.View full abstractDownload PDF (1141K)
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