Low molecular weight plasma proteins in the cerebrospinal fluid of children with hematological malignancies

1984 ◽  
Vol 12 (2) ◽  
pp. 131-136 ◽  
Author(s):  
M. B. Duggan ◽  
J. A. Whittaker ◽  
E. H. Cooper ◽  
C. C. Bailey ◽  
E. A. Robinson
Keyword(s):  
Molecular Weight ◽  
Cerebrospinal Fluid ◽  
Plasma Proteins ◽  
Hematological Malignancies ◽  
Low Molecular Weight

Comparison of the Non-Specific Binding of Unfractionated Heparin and Low Molecular Weight Heparin (Enoxaparin) to Plasma Proteins

1993 ◽  
Vol 70 (04) ◽  
pp. 625-630 ◽  
Author(s):  
Edward Young ◽  
Benilde Cosmi ◽  
Jeffrey Weitz ◽  
Jack Hirsh
Keyword(s):  
Molecular Weight ◽  
Unfractionated Heparin ◽  
Plasma Proteins ◽  
Low Molecular Weight Heparin ◽  
Specific Binding ◽  
Anticoagulant Activity ◽  
Factor Xa ◽  
Low Molecular Weight ◽  
Heparin Binding ◽  
Fixed Amount

SummaryThe non-specific binding of anticoagulantly-active heparin to plasma proteins may influence its anticoagulant effect. We used low affinity heparin (LAH) essentially devoid of anti-factor Xa activity to investigate the extent and possible mechanism of this non-specific binding. The addition of excess LAH to platelet-poor plasma containing a fixed amount of unfractionated heparin doubled the anti-factor Xa activity presumably because it displaces anticoagulantly-active heparin from plasma proteins. Although dextran sulfates of varying molecular weights also increased the anti-factor Xa activity, less sulfated heparin-like polysaccharides had no effect. These findings suggest that the ability to displace active heparin from plasma protein binding sites is related to charge and may be independent of molecular size. In contrast to its effect in plasma containing unfractionated heparin, there was little augmentation in anti-factor Xa activity when LAH was added to plasma containing low molecular weight heparin (LMWH), indicating that LMWH binds less to plasma proteins than unfractionated heparin. This concept is supported by studies comparing the anticoagulant activity of unfractionated heparin and LMWH in plasma with that in buffer containing antithrombin III. The anti-factor Xa activity of unfractionated heparin was 2-fold less in plasma than in the purified system. In contrast, LMWH had identical anti-factor Xa activity in both plasma and buffer, respectively. These findings may be clinically relevant because the recovered anti-factor Xa activity of unfractionated heparin was 33% lower in plasma from patients with suspected venous thrombosis than in plasma from healthy volunteers. The reduced heparin recovery in patient plasma reflects increased heparin binding to plasma proteins because the addition of LAH augmented the anti-factor Xa activity. In contrast to unfractionated heparin, there was complete recovery of LMWH added to patient plasma and little increase of anti-factor Xa activity after the addition of LAH. These findings may explain why LMWH gives a more predictable dose response than unfractionated heparin.

Low Molecular Weight Heparin Therapy: Is Monitoring Needed?

1994 ◽  
Vol 72 (03) ◽  
pp. 330-334 ◽  
Author(s):  
B Boneu
Keyword(s):  
Molecular Weight ◽  
Clinical Trials ◽  
Plasma Proteins ◽  
Bleeding Risk ◽  
Heparin Therapy ◽  
Low Molecular Weight ◽  
Vein Thrombosis ◽  
Meta Analyses ◽  
Deep Vein ◽  
Initial Check

SummaryRecent meta-analyses indicate that low molecular weight heparins (LMWH) are more effective than unfractionated heparin (UH) in preventing and treating deep vein thrombosis. This article presents the arguments for and against the need for laboratory monitoring. At the present time, the only tests currently available for monitoring LMWH therapy are those which measure the anti Xa activity in the plasma. Due to lower binding to plasma proteins and to cell surfaces,the plasma anti Xa activity generated by a given dose of LMWH is more predictable than for UH.Some clinical trials suggest that LMWH delivered at the recommended dose expose the patient to less bleeding risk than UH. Several . meta-analyses indicate comparable risk while any overdose unaccept-ably increases the haemorrhagic risk. The lowest dose of LMWH still effective in treating established DVT is presently unknown; some reports indicate that inadequate doses of LMWH are associated with a lack of efficacy for prevention. An overview of the published clinical trials indicates that the LMWH dose has never been monitored for prevention of DVT. In the treatment of established DVT, several trials have been performed without any monitoring, while in others the dose was adapted to target a given anti Xa activity. These considerations suggest that in prevention of DVT, monitoring the dose is not required. In the treatment of established DVT, considering the haemorrhagic risk of LMWH, the risk of undertreating the patient and the absence of large clinical trials comparing the advantages of monitoring the dose or not, it might be useful to check anti Xa activity at least once at the beginning of the treatment but the need for this initial check remains to be established. Because a large proportion of patients will be in the desired range, dose adjustments will be far less frequent than for UH.

Neutralisation of Heparan Sulphate and Low Molecular Weight Heparin by Protamine

1985 ◽  
Vol 53 (01) ◽  
pp. 086-089 ◽  
Author(s):  
A R Hubbard ◽  
C A Jennings
Keyword(s):  
Molecular Weight ◽  
Plasma Proteins ◽  
Low Molecular Weight Heparin ◽  
Heparan Sulphate ◽  
Activated Partial Thromboplastin Time ◽  
Weight Basis ◽  
Low Molecular Weight ◽  
Protamine Sulphate ◽  
At Iii ◽  
Reference Preparation

SummaryThe neutralisation by protamine sulphate (PS) of heparan sulphate (HS), a low molecular weight heparin (LMWH), and a reference preparation of unfractionated heparin (UH), was studied by activated partial thromboplastin time (APTT) and anti-Xa clotting assays. UH was most easily neutralised in the APTT assay by PS (on a weight for weight basis), followed by LMWH and HS. The neutralisation of APTT activity by PS closely followed the loss of activity in the anti-Xa clotting assay, when plasma was used as the source of At III. When the anti-Xa clotting assay was carried out using purified At III in place of plasma, HS and LMWH were neutralised by much lower amounts of PS and resembled UH neutralisation more closely. Resistance of HS anti-Xa activity to PS neutralisation decreased with increasing plasma dilution. The presence of bovine albumin with purified At III concentrate increased the resistance of HS to PS neutralisation. It is concluded that PS binding to UH, HS and LMWH is probably related more to their degree of sulphation than molecular weight and that non-specific interactions between PS and plasma proteins inhibit the binding of PS to HS and LMWH.

scholarly journals Autoantibodies to phosphatidylethanolamine (PE) recognize a kininogen- PE complex

Blood ◽  
1995 ◽  
Vol 86 (8) ◽  
pp. 3083-3089 ◽  
Author(s):  
T Sugi ◽  
JA McIntyre
Keyword(s):  
Molecular Weight ◽  
Plasma Proteins ◽  
Enzyme Linked Immunosorbent Assay ◽  
Low Molecular Weight ◽  
High Molecular Weight Kininogen ◽  
Recurrent Spontaneous Abortions ◽  
Glycoprotein I ◽  
Column Eluate ◽  
Adult Bovine Serum ◽  
Elisa Plate

Abstract Demonstration of autoimmune antiphospholipid antibodies (aPA) to negatively charged phospholipids (PL) in an enzyme-linked immunosorbent assay (ELISA) requires the presence of certain phospholipid-binding plasma proteins, eg, beta 2-glycoprotein I. We found a requirement for plasma against the electrically neutral or zwitterionic phospholipid, phosphatidylethanolamine (PE). Two of these PE-binding plasma proteins were identified as high molecular weight kininogen (HMWK) and low molecular weight kininogen (LMWK). We studied anti-PE antibody (aPE) seropositive plasma from 13 patients with SLE and/or recurrent spontaneous abortions by using partially purified kininogens and kininogen binding proteins from adult bovine serum isolated by carboxymethyl (CM)-papain affinity chromatography. Eleven of 13 sera recognized a kininogen-PE complex and/or a kininogen-binding protein-kininogen-PE complex. Some aPE-positive patient sera were shown to recognize highly purified HMWK and LMWK by ELISA only when the kininogens were presented on a PE substrate. These aPE sera did not recognize PE, HMWK, or LMWK when they were presented independently as the sole antigens on the ELISA plates. Other aPE-positive sera that did not react with PE-bound HMWK or LMWK reacted with the CM-papain column eluate when it was bound to PE, which suggests that these aPE recognize factor XI or prekallikrein, which normally bind to HMWK. The aPE ELISA reactivity of two patient sera were inhibited by preincubation of the CM-papain column eluate in the ELISA plate. These data show that most aPE are not specific for PE but require the presence of certain PL-binding plasma proteins that are kininogens or proteins in complex with kininogens. Our studies indicate that aPE bind to different plasma proteins than those implicated in anionic PL, aPA ELISA reactivity.

Isolation and Characterization of Human Platelet β-Thromboglobulin

1975 ◽  
Author(s):  
D. S. Pepper ◽  
S. Moore ◽  
J. D. Cash
Keyword(s):  
Molecular Weight ◽  
Plasma Proteins ◽  
Human Platelet ◽  
Weight Fraction ◽  
Human Platelets ◽  
Low Molecular Weight ◽  
Purification Procedure ◽  
Isolation And Characterization

The thrombin released products from washed human platelets were separated by filtration on 4% agarose in 0.15 M NaCl. The high molecular weight PF4 complex was dissociated and re-chromatographed in 0.75 M NaCl. The low molecular weight fraction, including β thromboglobulin and a low MW anti-heparin was freed of plasminogen anti-activator by dissociation and chromatography in pH 3.5 pyridine acetic acid. The anti-activator was irreversibly denatured and albumin was removed in the void volume of the column. A more suitable purification procedure for recovery of all activities was affinity chromatography on heparin-agarose. The anti-activator was excluded and could be obtained free of plasma proteins by Sephadex G-200 chromatography. The βTG eluted at 0.3 M NaCl and the low MW anti-heparin at 1.5 M NaCl. The pure βTG (MW 36,000) was injected into rabbits and the resulting antiserum used to produce a radioimmunoassay for the release reaction in vivo.

Further studies on low molecular weight proteins common to cerebrospinal fluid and urine

1967 ◽  
Vol 18 (3) ◽  
pp. 335-343 ◽  
Author(s):  
Ph. Walravens ◽  
E.C. Laterre ◽  
A. Estas ◽  
J.F. Heremans
Keyword(s):  
Molecular Weight ◽  
Cerebrospinal Fluid ◽  
Low Molecular Weight ◽  
Low Molecular Weight Proteins

Low molecular weight constituents of cerebrospinal fluid: N-benzoylglycine (hippuric acid)

1973 ◽  
Vol 20 (3) ◽  
pp. 893-896 ◽  
Author(s):  
Margaret W. Couch ◽  
M. Greer ◽  
K. N. Scott ◽  
C. M. Williams
Keyword(s):  
Molecular Weight ◽  
Cerebrospinal Fluid ◽  
Hippuric Acid ◽  
Low Molecular Weight
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