A comparison of Centrifugal and Membrane-based Apheresis Formats

1984 ◽  
Vol 7 (1) ◽  
pp. 35-38 ◽  
Author(s):  
H.J. Gurland ◽  
M.J. Lysaght ◽  
W. Samtleben ◽  
B. Schmidt

Membrane and centrifugal apheresis operate on different physical principles but are both capable of efficiently fractionating plasma proteins from whole blood. For therapeutic purposes, both formats yield about the same protein clearance per liter of solute exchanged and neither is significantly more rapid than the other. Only continuous centrifugation can be used to pherese cellular elements and only membrane filter can be deployed in ‘spontaneous’ circuits. Hardware for continuous centrifugation is more expensive and disposables less expensive than for the membrane methods; the ‘crossover’ occurs at 200 treatments. To date, only the centrifugal method is employed for donor apheresis; this may change in the future as membranes can yield a truly platelet-free product and appear to offer a much more rapid collection cycle.

1935 ◽  
Vol 62 (3) ◽  
pp. 353-258 ◽  
Author(s):  
James B. McNaught ◽  
Francis M. Woods ◽  
Virgil Scott

A non-splenectomized dog, on a vitamin-adequate basal diet, in the course of a plasmapheresis experiment, developed an uncontrollable anemia associated with the presence of bodies in or on the erythrocytes, indistinguishable from the descriptions of Bartonella canis. The normal plasma protein level of 7.3 per cent was reduced to 4.1 per cent by diet and the removal of 5354 ml. of whole blood in 33 bleedings. The Bartonella infection was transferred to a splenectomized dog by an intravenous injection of whole blood. Each animal was apparently sterilized by one injection of neoarsphenamine equivalent to 15 mg. per kilo weight. It is possible that the spleen liberates some substance into the blood stream which has an inhibitory effect upon a latent Bartonella infection and that this protective substance was diminished by the many bleedings associated with the lowering of plasma proteins in the non-splenectomized dog and was lacking in the inoculated splenectomized dog.


2011 ◽  
Vol 56 (No. 2) ◽  
pp. 63-74 ◽  
Author(s):  
L. Pavlata ◽  
M. Chomat ◽  
A. Pechova ◽  
L. Misurova ◽  
R. Dvorak

This paper evaluates the impact of long-term supplementation of different forms of zinc (Zn) and selenium (Se) on the content of these substances in the blood and hair of goats. Two analogous supplementation experiments were performed. 37 goats divided into four groups were used in the first trial with the Zn supplementation. Group A (n = 10) was a control group (with no Zn administered). A further three groups (B, C, D) were supplemented with Zn in various forms. Group B (n = 9) with zinc oxide, Group C (n = 9) with zinc lactate and Group D (n = 9) with zinc chelate. The second trial with Se supplementation was carried out on 20 goats divided into four groups. Group E (n = 5) was a control group. The other three groups were administered Se. Group F (n = 5) was supplied with a selenium lactate-protein complex, Group G (n = 5) with sodium selenite and Group H (n = 5) with selenium yeast. Three months later blood and hair samples were taken from all animals and Zn and Se concentrations were determined in whole blood, plasma, and hair. Glutathione peroxidase (GSH-Px) activity was determined in the Se supplementation trial group. At the end of the trial the Zn concentrations in plasma and whole blood were without major differences between the groups. The plasma concentration of Zn did not increase from the initial value at the start of the trial. In hair the average concentration of Zn was 95.2&ndash;100.0 mg/kg<br />in all groups. No conclusive relation was confirmed between the values of Zn in hair and its concentration in blood. The Se concentration in whole blood (&micro;g/l) at the end of trial in supplemented groups (F &ndash; 188.8 &plusmn; 24.6; G &ndash; 197.2 &plusmn; 10.9; H &ndash; 190.1 &plusmn; 26.3) was significantly higher (P &lt; 0.01) than in the control group (E &ndash; 103.1 &plusmn; 23.5). Similarly, the activity of GSH-Px (&micro;kat/l) was significantly higher in all supplemented groups (F &ndash; 872.3 &plusmn; 94.8; G &ndash; 659.5 &plusmn; 176.4; H &ndash; 839.8 &plusmn; 150.8) than in the control group (E &ndash; 379.1 &plusmn; 63.5). Se content in hair (&micro;g/kg) was higher also in all trial groups (F &ndash; 242.3 &plusmn; 41.5; G &ndash; 200.5 &plusmn; 46.9; H &ndash; 270.0 &plusmn; 106.8) than in the control group (E &ndash; 174.7 &plusmn; 38.0). However, it was significantly (P &lt; 0.05) higher only in Group F. A conclusive correlation was identified between the Se concentration in whole blood and its content in hair (r = 0.54; P &lt; 0.05; n = 20). Based on the results it can be concluded that none of the supplemented forms of Zn increased its concentration in blood, plasma and hair. On the other hand, the administration of Se led to an increase in the Se concentration in blood, increased the activity of GSH-Px in whole blood and the Se content in hair. Based on the proven correlation and regression relation between the Se concentration in blood and its content in hair, hair can be considered as a suitable material for the diagnosis of long-term Se status in goats. Goats with sufficient Se status are those that have more than 160 &micro;g/kg of Se in hair dry weight.


1981 ◽  
Author(s):  
J A van Mourik ◽  
P H G Lantinga ◽  
J A Hellings

Solid-phase immunoradiometric assays specific for Factor VIII coagulant antigen (VIII:CAg) and Factor VIII related antigen (VIIIR:Ag) have been used to assay the immunoreactivity of these antigens in plasma and whole blood during coagulation at physiological calcium concentration. When non-anticoagulated plasma, prepared from blood immediately after venipuncture, was incubated at 37°C, the concentration of VIII:CAg and VIlIR:Ag did not change. However, when whole blood, collected withoutanticoagulant, was incubated, the concentration of VIII:CAg gradually decreased to 50% of the initial value whereas the concentration of VIIIR:Ag remained unchanged. Gelchromatographic analyses revealed that coagulation of plasma leads to progressive dissociation of VIII:CAg from the factor VIII:VWF complex. When plasma was chromatographed before the onset of coagulation, VIII:CAg was eluted at the void volume together with VIIIR:Ag whereas after coagulation of the plasma VIII:CAg devoid of VIIIR:Ag was eluted after the void volume. Similarly, when the supernatant plasma from blood was chromatographed before the onset of coagulation, VIII:CAg together with VIIIR:Ag was eluted at the void volume whereas during and after coagulation the amount of VIII:CAg associated with VIIIR:Ag gradually decreased. However, no concomitant increase of the concentration of dissociated VIII:CAg was noted under the latter conditions. It seems likely, therefore, that adherance of dissociated VIII:CAg to cellular constituents accounts for the loss of VIII:CAg during coagulation of blood. On the other hand, it can not be excluded that cellular enzymes, extruded during coagulation, affect the antibody-binding capacity of VIII:CAg.Further studies indicate that, at least in part, dissociation of the factor VIII:VWF complex during coagulation is mediated by thrombin.


1987 ◽  
Author(s):  
T Sugo ◽  
S Tanabe ◽  
K Shinoda ◽  
M Matsuda

Monoclonal antibodies (MCA’s) were prepared against human protein C (PC) according to Köhler & Milstein, and those that recognize the Ca2+-dependent PC conformers were screened by direct ELISA in the presence of 2 mM either CaCl2 or EDTA. Out of nine MCAߣs thus screened, five MCA's designated as HPC-1˜5, respectively, were found to react with PC in the presence of Ca2+ but not EDTA. By SDS-PAGE coupled with Western Blotting performed in the presence of 2 mM CaCl2, we found that two MCA’s HPC-1 and 2, recognized the light chain, and two others, HPC-3 and 4, recognized the heavy chain of PC. But another MCA, HPC-5 was found to react with only non-reduced antigens. Further study showed that HPC-1 and 5 failed to react with the Gla-domainless PC, i.e. PC from which the N-terminal Gla-domain of the light chain had been cleaved off by α-chymotrypsin. However, all the other three MCA's retained the reactivity with the antigen in the presence of Ca2+ even after the Gla-domain had been removed. The binding of these MCA’s to PC in the presence of Ca2+ was found to be saturable with respect to the Ca2+ concentration and the half maximal binding for each MCA was calculated to be about 0.5+mM. Moreover, many other divalent cations such as Mg2+, Mn2+ , Ba2+, Zn2+, Co2+, Sr2+, were found to substitute for Ca2+ in inducing the metal ion-dependent but Gla-domain-independent conformer of PC.Cross-reactivity to other vitamin K-aependent plasma proteins was examined by direct ELISA; HPC-2 and 3 reacted solely to PC, but HPC-1 and 4 also reacted with prothrombin and HPC-5 with both prothrombin and factor X.These findings indicated that there are two or more metal binding sites besides the Gla-domain, possibly one in the light chain and the other(s) in the heavy chain. The presence of these metal binding sites may contribute to the unique conformer of vitamin K-dependent plasma proteins including protein C.


1983 ◽  
Vol 29 (12) ◽  
pp. 2049-2053 ◽  
Author(s):  
J T Wu ◽  
E Mau ◽  
J A Knight

Abstract Using the reagents from the CEA-Roche kit, we found that solutions containing only glycosaminoglycans (GAG) yielded false concentrations of carcinoembryonic antigen (CEA), and mixtures of CEA and GAG produced falsely high values. On the other hand, solutions of GAG yielded no additional CEA concentration when reagents from the Abbott CEA kit were used; rather, the CEA result was decreased with the Abbott kit for a CEA solution also containing GAG. These effects of GAG were not ascribable to contamination, because neither gel filtration nor ion-exchange column chromatography separated the false Roche CEA content related to GAG from their peaks of uronic acid or from their anticoagulant activity. In addition, an enzyme specific for GAG eliminated these GAG-derived false concentrations. Both the positive and negative effects are correlated with concentrations of GAG. We found that the concentration of GAG could be decreased in a solution containing plasma proteins by either heating (70 degrees C, 15 min) or treating with perchloric acid (0.6 mol/L). The former is superior because essentially all GAG added to a solution containing plasma proteins were removed by heat, whereas as much as 25% to 80% of the GAG still remained after acid treatment. The effect of GAG was also completely eliminated by treating the specimens with chondroitinase ABC lyase (EC 4.2.2.4).


Author(s):  
T. Scofield

The medical successes realized in Vietnam can be attributed to several factors: rapid evacuation of casualties by helicopter or ambulances; the availability of whole blood; well-equipped field hospitals; highly skilled and well-organized surgical teams; and improved medical management. Of these important factors, rapid evacuation by helicopter contributed the most to saving the lives of the wounded. Without effective helicopter evacuation, it would have been difficult to exploit the other factors and management of medical resources would have been less efficient.


1996 ◽  
Vol 19 (1) ◽  
pp. 14-17 ◽  
Author(s):  
J. Stange ◽  
S. Mitzner

The present review discusses hepatocyte sources for a bioartificial liver. Intended requirements for cell sources are for example: synthesis of plasma proteins, detoxification and regulation. The need for highly differentiated hepatocytes is stressed. Furthermore, the gap between this objective on the one hand and the real possibilities as they appear today on the other is shown. Alternatives to primarily isolated hepatocytes are discussed, thereby elucidating the limits of established cell lines. In summary, it is postulated that the results expected from a bioartificial liver, are closely related to the source and type of cells used.


1980 ◽  
Vol 60 (4) ◽  
pp. 869-876 ◽  
Author(s):  
J. A. BASARAB ◽  
R. T. BERG ◽  
J. R. THOMPSON

Osmotic fragility of erythrocytes was determined on heparinized whole blood, sampled from a group of 95 cattle consisting of 73 normal animals from three breed groups and 22 animals showing varying degrees of the double-muscling (DM) trait. Four age groups and two sex groups were sampled from each breed group. Mean corpuscular fragility (MCF) values (the NaCl equivalence producing 50% hemolysis) were interpolated from a fragility curve derived for each animal. The DM breed group had significantly increased erythrocyte fragility as compared to the other breed groups. As animal age increased, the fragility of the erythrocytes was significantly decreased. Sex did not appear to influence erythrocyte fragility. Erythrocyte fragility was also related to the degree of phenotypic expression of the DM trait. Phenotypically extreme DM cattle had increased erythrocyte fragility as compared to phenotypically moderate- to normal-muscled animals of the DM group. Erythrocyte fragility in two of the other breed groups overlapped into the erythrocyte fragility range of the phenotypically moderate- to normal-muscled animals of the DM group, while the remaining breed group showed a decreased erythrocyte fragility. This overlapping provides adequate grounds for the rejection of the erythrocyte osmotic fragility test used in this study as a means of unequivocal identification of DM carriers in cattle. Despite the rejection of this test as a means of carrier detection, the suggestion that DM cattle may have a "generalized membrane defect" is still considered valid.


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