bluuebunny/crossref_metadata_2025_split huggingface dataset:
Lectin Binding Demonstrates Different Glycoprotein Abnormalities In Thrombasthenic And Bernard-Soulier Platelets
Authors: Judson Philip A , Anstee David J 
Published: July 2018

We have previously shown that the lectins from Maclura aurantiaca (Ma) and Arachis hypogaea (Ah) (peanut) bind selectively to GP-I in human platelet membranes. In contrast Concanavalin A lectin binds primarily to GP-III. GP-I is deficient or absent from the membranes of individuals with Bernard-Soulier Syndrome (B-S.S.) while GP-II and III are deficient or absent from Thrombasthenic (G.T.) platelets. We have investigated the binding of radioiodinated lectins to SDS polyacrylamide gels of whole platelets from patients with B-S.S. and G.T. The object of this study was to define further the nature of the glycoprotein abnormalities in these conditions.The results clearly demonstrated a marked reduction in the binding of Ma and Ah lectins to the GP-I region of B-S platelets when compared to that of normal platelets. No new lectin binding components were observed. The binding of Con A lectins to B-S platelets did not appear to be significantly different from that to normal platelets. In contrast Ma and Ah binding to G.T. platelets appeared normal whereas the binding of Con A to GP-III was markedly reduced. Two faint Con A binding bands were apparent in the GP-III region of the G.T. platelets. It is not clear whether either of these represent residual GP-III or if they are minor components masked by GP-III in normal platelets. The carbohydrate of GP-I in normal platelets consists almost entirely of O-glycosidically linked oligosaccharides. Ah and Ma lectins bind selectively to galactosyl and N-acetylgalactosaminyl residues in this type of oligosaccharide. We conclude that B-S platelets have a gross deficiency of O-glycosidically linked oligosaccharides. Con A binds selectively to branched N-glycosidically linked oligosaccharides with a mannose-rich core. We conclude that such structures normally present on GP-III are grossly deficient in G.T. platelets.
Membrane Glycoprotein Defects In Bernard-Soulier Syndrome Platelets
Authors: Clemetson K J , McGregor J L , James E , Dechavanne M , Lüscher E F 
Published: July 2018

It is well established that Bernard-Soulier syndrome (BSS) platelets are deficient in a major membrane glycoprotein (lb). In order to investigate if this is the only defect in this disorder and to see if the β-subunit of glycoprotein lb is also diminished, platelets from 3 BSS patients and from healthy donors were isolated, washed and surface labelled by lactoperoxidase-catalysed iodination, pèriodate/NaB3H4 or neuraminidase/ galactose oxidase/NaB3H4. Labelled platelets were solubilized in sodium dodecyl sulphate and separated by 2-dimensional gel electrophoresis (isoelectric focusing, discontinuous polyacrylamide gel electrophoresis). Glycoprotein Ibα was virtually absent in 2 patients and strongly decreased in the third patient. The 3-subunit was also absent in the 2 patients and present at about 40 % of normal in the third. Glycoprotein IIbβ was present normally in all patients. In addition, a further low molecular weight glycoprotein with a M.WT. of 17,000 and a pI of 6.8-7.5 was absent or present at levels paralleling glycoprotein Ibβ. The thrombin cleavable glycoprotein (GP IV or V) appeared greatly diminished with BSS platelets labelled by carbo-hydrate specific methods though no difference could be seen with iodination. This finding was confirmed in a fourth BSS patient using one dimensional gel electrophoresis.The defects in BSS platelets are thus more complex than previously thought.
Hypoxia And Acidosis Induce The Release Of Plasminogen Activator From Vessel Walls
Authors: Tappy L , Bachmann F 
Published: July 2018

The mechanisms, which induce the release of vascular plasminogen activator (VA), are not fully understood. To test the effects of hypoxia and of acidosis on the liberation of VA fran the vessel wall, we have used the isolated pig ear perfusion system described by Markwardt and Klöcking. Pig ears, collected at the slaughterhouse, were kept on ice for a maximum of 4 hours. A catheter was placed into the main artery and the ear flushed with oxygenated HEPES-Tyrode’s solution pH 7,4 for 30 min at 37 °C. Baseline activities in effluent fractions from time 30-42 min, averaged 0,95 U UK/ml. Assays were performed on plasminogen rich fibrin plates. Frcm 43 to 65 min, pig ears were perfused with oxygenated HEPES-Tyrode's solution pH 7,4 (controls) or pH 6,7 (acidosis), or within the same buffer (pH 7,4) pretreated by extensive nitrogen bubbling (hypoxia).VA concentrations in controls remained fairly constant until 65 min. The hypoxia stimulus resulted in an increase of PA activity of 180% over basal activity (p < 0,001). Acidosis led to a mean increase of PA activity of 240%
(p < 0,001)These experiments suggest that acidosis and hypoxia, if present distally to venous segments occluded by a thrombus, may represent powerful stimuli for the secretion of plasminogen activator frcm vessel walls.
Fibrinolysis After Multiple Trauma In Man. Clinical And Methodological Aspects
Authors: Teger-Nilsson A-C , Gyzander E , Medegård A , Risberq B , Wiman B 
Published: July 2018

Fifteen patients with at least two bone fractures and damages of soft tissues, mainly after traffic accidents, were investigated for changes in the fibrinolytic system. Seventeen healthy students were controls. The patients were conventionally treated in an intensive care unit. Blood samples, in all 140, were taken on the day of admission and then daily for about one week. The blood was analysed for plasminogen with electroimmunoassay and with chromogenic substrate after streptokinase activation, for α 2-antiplasmin with electroimmunoassay and two types of activity measurements (chromogenic substrate), for α 2-antiplasmin - plasmin complexes with RIA technique, and for α 2-macroglobulin with electroimmunoassay and activity measurements. In addition fibrinogen, fibrinogen-fibrin degradation products and fibrinolytic activity on fibrin plates were estimated.Plasminogen was somewhat low the first days after trauma lowest 69 % ± 22 % (M ± SD), day 3]. It then slowly increased towards the end of the investigation (highest 123% ± 21%). The last days of investigation the immunological method also gave higher values than the activity method, α 2 Antiplasmin was low directly after the trauma (lowest 67% ± 18%, day 1 ) and increased gradually (highest 115% ± 19%, day 6 ). The first days after trauma immunological method gave higher values than the activity methods, α 2 Antiplasmin - plasmin complexes varied, but showed occasionally high values in particular the first day. α 2 -Macroglobulin decreased only slightly on day 5-6, when it also showed a difference between the immunological and activity methods.It is concluded that the fibrinolytic system is activated immediately after a trauma. Later there is an increase of plasminogen, α 2 antiplasmin and fibrinogen, probably due to an acute phase reaction. Some reasons for the methodological discrepancies are discussed. Serial analysis of α 2-antiplasmin activity seems to be a relevant method for evaluation of fibrinolysis in a complex clinical situation.
An Enhancing Effect Of Smoking On Fibrinolysis
Authors: Allen R A , Kluft C , Brommer E J P 
Published: July 2018

The effect of smoking two cigarettes in 15 minutes on the fibrinolytic enzyme system in blood, was investigated. Samples were taken, using an indwelling catheter over a 1 hr period (starting at 9 a.m.), from 18 apparently healthy volunteers in fasting condition. The pre-smoking sample, considered to be a true base-line sample, was taken 30 minutes after the initial sample. In the subsequent 15 minutes two average (re: tar and nicotine) cigarettes were smoked; controls “smoked” unlit cigarettes. Samples were taken at the middle and at the end of the smoking period, as well as + 22.5 and + 30 minutes from the start of smoking. The heart rate was monitored throughout.Haematocrit values, before and after smoking, did not change significantly, but carboxyhaemoglobin levels rose on average in inhaling smokers from 3.0 to 5.1% and the average heart rate increased from 64 to 76 beats/minute after smoking.On screening euglobulin fractions of each sample on normal fibrin plates a small, but consistent, increase in fibrinolytic activity was seen, apparently due to smoking (an increase of up to 2.1 BAU). Activation of intrinsic systems, via factor XII, could not be demonstrated, but further analysis of the increase in fibrinolytic activity revealed quenching by anti-tissue activator antibodies and not by anti-urokinase antibodies.Thus, in conclusion a small, but consistent increase in the circulating level of extrinsic plasminogen activator activity was detected after smoking 2 cigarettes.
A Correlation Between Anticoagulant Activity, Molecular Weight And The Increase In Antithrombin-III Fluorescence Produced By Heparin Fractions
Authors: Mardiguian J , Aiach M , Trillou M , Michaud A 
Published: July 2018

The aim of this study was to correlate the anticoagulant activity of heparin with its affinity for Antithrombin-III.Eleven fractions of different molecular weight (3900 - 42000 daltons) were obtained by fractionation of a Commercial heparin on Ultrogel AcA 44. The anti-Xa and antithrombin activities of these fractions were measured by chromogenic assays and expressed on a molar basis. Their affinity for antithrombin-III was assessed by measuring their ability to increase bovine antithrombin-III tryptophan fluorescence.A linear relationship was obtained between fluorescence enhancement (F), expressed on a molar basis, and molecular weight (M), (F = -26,50 + 0,01 M) as well as between anti-Xa activity, anti-thrombin activity and F.This study shows that the anti-Xa and the anti-thrombin activities of heparin are increasing with its capacity to enhance the fluorescence of antithrombin-III and that this capacity is increasing with molecular weight.
Low Molecular Weight Heparin And Postoperative Deep Vein Thrombosis
Authors: Kakkar V V , Djazaeri B , Webb P , Scully M , Westwick J , MacGregor I 
Published: July 2018

Recent studies have indicated that commercially available heparin is a hetrogenous compound consisting of the molecules of diverse chain length and different molecular weights. Low molecular weight (LMW) heparin has been shown in vitro to possess unique properties which should not only improve its efficacy for preventing post-op DVT but also reduce or eliminate the risk of bleeding complications. The aim of this paper is to report the results of in vivo studies performed to test this hypothesis.Ten healthy volunteers received 5000 USP units of unfractionated heparin (mol. wt. 15,000 daltons) or equivalent amount of LMW heparin (mol. wt. 6000 daltons) subcutaneously. Blood samples were withdrawn 1/2 1, 3 and 5 hours later. These were analysed for anti-thrombotic effect using anti-factor Xa (anti Xa) assay and anticoagulant effect by estimating kaolin cephalin clotting time (KCCT) method. While both the preparations of heparin produced similar response in KCCT assay, LMW heparin was found to be 4 times more active in anti-Xa assay. 30 patients undergoing major abdominal surgery were randomly allocated to receive either 5000 units of unfractionated heparin or equivalent amount of LMW heparin every 12 hourly for 10 days. Blood samples were withdrawn before, during and immediately after surgery and every day during post-op period. These were analysed for anti-thrombin III and heparin concentrations, lipoprotein lipase, fibrinopeptide A, prekallikrein, TxB2 and 6-oxo-PGF1α to assess platelet effect. Significant differences were only observed in lipoprotein lipase and anti-thrombin III concentrations.
In ongoing trial 43 patients undergoing major abdominal surgery have received 1500 units of LMW heparin every 12 hourly for 7 post-operative days. Only 1 patient has developed DVT and another wound haematoma. If these results are confirmed in a larger number of patient, then LMW heparin may be ideal drug for prophylaxis against DVT.
In Vivo Studies On The Inhibition Of Coagulation By Fractionated Heparin
Authors: Schmitz-Huebner U , Balleisen L , Asbeck F , van de Loo J 
Published: July 2018

Recent investigations suggest that low molecular weight heparin may have advantages over conventional heparin with regard to the prevention of venous thrombosis and haemorrhagic side effects.High (HMW) and low (LMW) molecular weight heparin fractions with mean MWs of 16,000 and 8,800 respectively, obtained by gel filtration chromatography of sodium mucosal heparin (B. Braun Melsungen), were injected subcutaneously into six volunteers and compared with the unfractionated substance in a cross-over trial. Doses of 5,000 U were administered twice daily over a period of three days and heparin activity was controlled before injection and 2,4,8 hours afterwards by means of the APTT, the anti-Xa clotting test and a chromogenic substrate assay. In addition, the in vivo effect of fractionated heparin on platelet function was examined. The results show that the LMW fraction induced markedly higher anti-Xa activity than the other preparations. At the same time, APTT results did not significantly differ. Unfractionated heparin and the HMW fraction enhanced ADP-induced platelet aggregation and collagen-mediated MDA-production, while the LMW fraction hardly affected these assays, but potently inhibited thrombin-induced MDA production. All heparin preparations stimulated the release of PF IV, whereas the serotonin content of platelets determined at the same time increased.It is concluded that s.c. injections of LMW heparin induce relatively high levels of anti-Xa activity without leading to sensitive platelet activation or to major effects on overall clotting tests.
Possible Mode Of Action Of A Semi-Synthetic Heparin Analogue . (SSHA)
Authors: Kakkar V V , Djazaeri B , Scully M F , Westwick J 
Published: July 2018

It has been suggested that following parenteral injection, the anti-thrombotic effect of SSHA is possibly related to release of endogenous glycosaminoglycans probably from vascular endothelial cell surface. In this study, the mechanism of action of SSHA has been explored further.Five healthy volunteers received 3 different doses of SSHA (75, 50, 35mgs) and 50mgs of heparin subcutaneously, four days apart, and venous blood samples were taken at 0,3,5 and 7 hours post injection. These were analysed for prothrombin time, KCCT, lipoprotein lipase, βTG, PF4 and prekallikrein levels. Heparin activity was measured by an anti-factor Xa assay. In addition, template bleeding times were done before and after the administration of 75mg of SSHA and 50mgs of heparin. Prothrombin time response, following addition of varying doses of SSHA and heparin to pooled blood was also studied.Although SSHA prolonged the template bleeding time, the difference as compared with control value was not statistically significant. Heparin in a similar dose prolongs the template bleeding time to a lesser extent. No significant differences were observed in the levels of βTG, lipoprotein lipase, prekallikrein levels, KCCT and heparin activity following administration of SSHA and heparin. Unlike heparin, SSHA in a dose related manner significantly prolongs prothrombin time, the difference being significant at 1,3 and 5 hours following administration of each dose. These findings suggest that part of antithrombotic effect of SSHA may be mediated through inhibition of extrinsic pathway of activation of intravascular coagulation.
Is Warfarin Sodium Absolutely Contraindicated During Lactation?
Authors: McKenna R , Cole E R , Vasan U S 
Published: July 2018

There is widespread concern regarding the secretion of a variety of drugs and toxins into human milk. A survey of the practices of obstetricians and neonatologists at 2 teaching medical centers regarding the appropriateness of allowing a mother on warfarin sodium to breast feed her infant revealed that almost all advised such mothers against breast feeding. This study reports the data on two mother- infant pairs who were evaluated with Prothrombin time activity (Protime), Factor II (FII) and Factor VII/X (FVII) levels simultaneously while the mothers were on warfarin sodium and the infants were exclusively breast fed. Both mothers had extensive serious venous thromboembolic disease necessitating the administration of anticoagulants; warfarin sodium was first started in both mothers in the post-partum period.The prothrombin time activities on the first mother-infant pair, on blood samples drawn simultaneously are shown below.Breast milk extracted from this mother on one occasion did not reveal any warfarin sodium by a spectrophotometric assay. Data on the second mother-infant pair on blood samples obtained simultaneously were as follows.These data demonstrate conclusively that there is no inhibition of the coagulation mechanism in normal full term infants when they are breast fed by mothers who are therapeutically anticoagulated with warfarin sodium.
β-Propiolactone/Ultraviolet Irradiation: Quantitative Studies On Effectiveness For Inactivation Of Hepatitis B Virus
Authors: Prince A M , Stephan W , Brotman B 
Published: July 2018

The efficacy of combined β-Propiolactone/Ultraviolet irradiation (βPL/UV) for inactivation of hepatitis B virus in labile blood derivitives has been reinvestigated. To permit quantitative estimation of process efficacy, a regression analysis of the relation between virus dose and incubation period was carried out. This has provided a means for estimating virus titer and for determining the accuracy of such estimates.The data suggest that βPL/UV can reduce virus titer about 10,000,000 fold (10-7). The process efficacy for βPL/UV followed by the Aerosil adsorption procedure used in preparation of stabilized human serum (Biseko) containing most human serum proteins except for removal of factor VIII, the PPSB factors, fibrinogen and the lipoproteins was estimated to be about 10-8.This degree of virus inactivation should be more than sufficient to sterilize the highest amounts of hepatitis B virus which could be expected in pooled human plasma which has been screened for HBsAg.
Prothrombin Fragment 1.2.3, A Major Product Of Prothrombin Activation In Human Plasma
Authors: Rabiet M J , Furie B , Furie B C 
Published: July 2018

The conversion of human prothrombin to thrombin is associated with a number of cleavage intermediates and products whose appearance and concentration are dependent upon the prothrombin activation conditions used. In the current investigation, the fragments of prothrombin which appear in normal human plasma after activation of the blood coagulation cascade were studied. Radioiodinated human prothrombin was added to platelet-poor relipidated normal human plasma and clotting initiated with Ca(II) and kaolin. The radiolabeled prothrombin cleavage products which formed were analyzed by polyacrylamide gel electrophoresis in the presence of dodecyl sulfate (SDS) and 2-mercaptoethanol (2-ME), A new product of prothrombin activation was observed. Its migration was more rapid than prethrombin 1 and slower than fragment 1.2. No previously identified products of prothrombin activation migrated to the same position in the gel.The previously unrecognized fragment was identified as fragment 1.2.3 as follows. Prothrombin was activated by factor Xa in the presence of Ca(II) and phospholipid. The desired product was isolated by absorption to and elution from barium citrate and by DEAE cellulose chromatography. This purified material, migrating identically with the unknown plasma product was homogeneous upon SDS gel electrophoresis with 2-ME. The amino terminal sequence of the isolated material was identical to that of prothrombin. Digestion of this material with either factor Xa or thrombin yielded as major products fragment 1.2 and fragment 1. (Fragment 2 and fragment 3 eluted from the gels under the conditions employed). Amino terminal sequence analysis of the factor Xa digestion products of the isolated material indicated three amino acid residues at each cycle. The sequences of fragment 1, fragment 2, and fragment 3 are consistent with this sequence analysis. On this basis we suggest that fragment 1.2.3 is a prominent product of prothrombin conversion to thrombin in plasma.
An Acquired Inhibitor To Coagulation Factor II
Authors: Scully M F , Ellis V , Kakkar V V , Savidge G F , Williams Y F , Sterndale H 
Published: July 2018

A 77 year old woman with symptoms of GI tract bleeding, haematuria, bruising and profuse bleeding after dental extraction was found to have a prolonged thrombin time (>90 secs) but normal reptilase time and fibrinogen level. Both prothrombin time and KCCT were prolonged to greater than twice normal values. She had no previous history of bleeding problems and no drug history apart from analgesics.On investigation of citrated plasma samples an antithrombin III level as measured in a chromogenic heparin cofactor assay of 607% was found but measured immunologically of 120%. Upon chromatography on Ultragel AcA44 two peaks of antithrombin activity were observed one eluting in the position of normal antithrombin III immunologically. The activity of this fraction differed according to whether the antithrombin assay was a progressive type or heparin cofactor. The other much larger peak eluted in this second peak off AcA44 and the activity was not susceptible to heparin. The activity in this peak was pooled and chromatographed on DEAE Sephacel. It eluted in 0.0175 M Na (P) pH 6.8 as a single peak coincident with antithrombin activity. On SDS electrophoresis a single band was obtained. This fraction corresponds to IgG. Less than 10% of the activity was eluted with 0.08 M (P) pH 6.6 in the fraction containing IgG and IgA.The purified IgG directly inhibited thrombin. When added to normal plasma and prothrombin measured using activated factor Xa, complete loss of prothrombin was observed at dilutions of the inhibitor corresponding to 25% of that found in the patient plasma. The inhibitor had no effect on the rate of generation of factor Xa in normal plasma (S2222) as initiated by thromboplastin nor on the activity of purified factor Xa. The evidence suggests that this is the first report of an acquired inhibitor specific for factor II.