bluuebunny/crossref_metadata_2025 huggingface dataset:
In Vivo Catabolism of Human Fibrinogen Fragment D in Normal Subjects and Patients with Liver Cirrhosis
Authors: Ardaillou N. , Yvart J. , Larrieu M.J.
Published: May 2019

The in vivo catabolism of purified 131-I-fragment D (Fg D) was studied in comparison with that of 125-I-Fibrinogen (Fg) simultaneously injected in 6 controls and 8 patients with liver cirrhosis. Fg D, M.W. 85,000, was obtained following prolonged (24 hours) plasmin digestion of human Fg. Labelling was performed using the chloramine T method. Linlabelled and labelled Fg and Fg D were characterized hy immunoelectrophoresis and SDS Polyacrylamide gel electrophoresis. Radioactivity was measured in thrombin-clottable (Fg) and TCA-precipitable (Fg D) proteins from plasma. Labelled Fg D present in plasma samples 1, 6 and 12 hours following injection eluted from Sephadex G 2D0 at the same position as native Fg D. A two compartment system was derived from the corresponding plasma disappearance curves for both Fg and Fg D in controls and patients. In controls, the first component of Fg D disappearance curve represented 54.1±13.4% of the total clearance with T 1/2 of 2.5±0.9 hours. The T 1/2 of the second component was 3.9±1.0 hours, Fg D disappeared more rapidly from plasma than Fg, and the ratio of Fg D to Fg was 0.11-0,02. In patients with liver cirrhosis, there was a significant (p<0.005) increase of T 1/2 of the second component (13.6±2.6 hours), whereas the in vivo survival of Fg was normal (4 cases) or decreased (2 cases). These results suggest that the liver interfers with the metabolic clearance rate of Fg D.
Variant Plasminogens in Patients with a History of Venous Thrombosis
Authors: Robbins K.C. , Wohl R.C. , Summaria L.
Published: May 2019

Kinetic methods will be described For measuring plasminogen and for studying plasminoge activation in human plasma, using specific synthetic substrates, with different activat, species. These studies resulted in the discovery of several patients plasmas containin-variant, or abnormal, plasminogen molecules; these plasmas showed lower observable activation rates. Plasminogen isolated from these plasmas activated with Identical catalytic rate constants to normal plasminogen, by different activator species, but the apparent Michaelis constants were 10- to 100-fold higher. These data lead to the conclsion that the binding properties of the activator species to the variant plasminogens have been impaired. The interpretation of the data In two patients with venous thrpto-sis was possible only in terms of homogeneous populations of plasminogen molecules. These individuals have to be considered homozygous with respect to their plasminogens, and Family studies Indicate the possibility of an autosomal dominant hereditary transmission. The urokinase activation data with the variant plasminogens point to an activation mechanisn identical to that proposed for streptokinase, namely the activation of Plasminogen hy a plasminogen-urokinase complex, analogous with the plasminogen-streptokinase comnlex.
Hereditary Bleeding Disorder due to Primary Defects in Platelet Release Mechanism
Authors: Wu K.K. , Chen Y.C. , Walasek J. , Smith C.
Published: May 2019

Aspirin-like platelet release defect remains a poorly defined entity. To gain understa nd of its pathophysiologic and genetic characteristics, 5 kindreds were investigated. All 5 propOsiti were females with ages ranging from 26 to 62 years. Each patient had had easy bruising, recurrent epistaxis and hypermenorrhea since early childhood. Abnormalities in release reaction were characterized by an absence of secondary- wave aggregation in response to ADP and epinephrine, a marked reduction of collagen-and arachidonate induced aggregation and a reduc tion in l4C-se rotonin release. The plateiet ADP, ATP content and ATP/ADP ratio were normal in all the patients. Ther elease defect was definitely not due to drug usage. No salicylates were detectable in the blood. Bleeding time war prlonged in only 2 patients. Platelet factor 3 availability was abnormal in approximatly 40% of the affected subjects. The platelet count, morphology and retention, clot retraction and ristocetin-induced aggregation were normal. The inheritance pattern which could be adequately evaluated in 4 kindreds is consistent with an autosomal dominant trait. Calcium ionophore A23187 aggregated the patient platelets normally, indicating that the intracellular calcium transport mechanism is intact in this disorder. We conclude that primary platelet release defectis an entity of he reditary thrombocy topathies with welldefined clinical and laboratory manifes tations.
Aspirin, Dipyridamole, Prostacyclin (PGI2) and Bleeding Time in Rats
Authors: Villa S. , de Gaetano G.
Published: May 2019

It has been suggested that dipyridamole (D) impairs platelet function by potentiating the inhibitory effect of endogenous circulating PGI2. Treatments combining D with aspirin - at doses inhibitine PGI2 synthesis - could therefore reduce its inhibitory effect on platelet function. We have tested this hypothesis on bleeding time in unanaesthetized male CD rats. Bleeding times were measured on the animal’s tails (immerged in saline at 37°C) by a standardized template technique, 5 min after drug treatment. Neither aspirin (5 - 200 mg/kg i.p.) nor D (30 mg/kg i.p.) significantly modified bleeding time. Pretreatment with aspirin from 5 min to 24 h before D resulted in marked lengthening (>10 min) of bleeding times. Aspirin pretreatment also potentiated - not reduced - the effect of two D congeners (SH-869 and VK-774) used at doses which themselves significantly prolonged bleeding times. D strongly potentiated the prolonging effect of exogenous PGI2 on bleeding time. These data indicate that the interactions between aspirin, D (or its derivatives) and PGI2 at the level of primary haemostasis mechanisms in the rat are complex and may involve factors other than platelets (such as blood flow in the micro-circulation). They also suggest that pharmacological data obtained with exogenous PGI2 does not necessarily reflect the physiological role of the endogenous substance.
Protein Distribution in Human Endothelial Cells in Primary Culture Studied by Sodium Dodecyl Sulphate Polyacrylamide Gel Electrophores
Authors: Børsum T. , Hagen I. , Henriksen T. , Carlander B.
Published: May 2019

The surface structure and protein composition of cultured human endothelial cells were examined by lactoperoxidase catalyzed iodonation followed by SDS-PAGE of the cells. Five major protein bands (MW 224.000, 187.000, 70.000, 52.000 and 42.000) and several minor bands were seen. No differences in the protein pattern were observed between samples from confluent and nonconfluent cultures. In contrast, PAS staining of the gels revealed no glycoprotein bands unless the cells had grown to confluency. Then PAS staining revealed three bands of MW 240.000, 208.000 and 145.000. The fire one may represent fibronectin. The radioavtive iodine was associated with proteins in the 230.000, 145.000, 70.000, 55.000 and 45.000 MW regions. The first two regions showed iodination only in samples from confluent cultures. 33% of the acid-hydrolyzable sialic acid was liberated after neuraminidase treatment of the cells. No difference in the protein or glycoprotein pattern was seen after SDS-PAGE of neuraminidase-treated cells. In conclusion, four of the protein bands were susceptible to iodination, indicating an external localization in the plasma membrane. Two of these were iodinated only when cells had grown to confluency.
Effect of PGI2 and Its Derivatives on Platelet Adherence Aggregation and PF3 Availability
Authors: Fésüs L. , Stadler I. , Hársfalvi J. , Balogh M. , Kovács E. , Muszbek L.
Published: May 2019

10-8M PGI2-Na completely inhibited collagen induced aggregation of human platelets and the concomitant appearance of platelet factor 3 activity, but did not affect the adherence of platelets to collagen fibrils. At the same time, the presence of PGI2-Na could prevent the retention of platelets by glass beads.

Comparing to the inhibition of ADP induced aggregation a higher dose of PGI2-Na was needed to inhibit platelet aggregation by ionophore A23187. Furthermore, unlike ADP aggregation, increasing dose of ionophore could counteract the inhibitory effect of PGI2-Na. The shift of platelet actin from G to F from during ionophore aggregation could be prevented by appropriate dose of PGI2-Na. PGI2 derivatives (Chinoin, Hungary) with increased stability, although in higher doses, exerted activities similar to PGI2-Na.
Dietary Fat, Platelet Functions and Coronary Heart Disease (CHD) in British and French Farmers
Authors: Renaud S. , Morazain R. , Godsey F. , Dumont E. , Symington I.S. , Gillanders E. M. , O’Brien J.R.
Published: May 2019

Statistics have shown that the incidence of CHD is much higher in West than in East Scotland and South England as well as in Moselle than in Var, in France. Studies have been performed with a mobile laboratory in 8 groups (20 to 50 subjects each) of healthy male farmers (40-45 years) from these regions, to compare platelet functions and composition with the intake of nutriments and plasma lipids. In addition, the intake of polyunsatured fats has been increased at the expense of the saturated, in a group of 53 French farmers from Moselle. There was no significant difference in the serum total cholesterol, HDL cholesterol or triglycerides between West and East Scotland, as well as between Var and Moselle. By contrast, there were significant differences in the linoleic acid contents of plasma which was the lowest (26 %) in West Scotland (P/S=0.22) and the highest (34%) in Moselle farmers (P/S=1.45) one year after diet modification. The platelet clotting time (F3-CT) was the most accelerated in West Scotland (255 sec) and the longest (343 sec) in Moselle, aftet diet modification. In France as in Scotland, most (France), if not all (Scotland) platelet functions investigated (clotting activity, agregation to thrombin ADP, epinephrine, collagen), were markedly increased in relation to a higher intake of saturated fats in the regions with a higher CHD incidence.
Use of an Activated Prothrombin Complex Concentrate (Auto Factor IX-Hyland) in the Control of Bleeding of Haemophilic (A) Patients with Inhibitor of Factor VIII
Authors: Watson-Williams E.J. , Abildgaard C.F. , Turner E. A.
Published: May 2019

One of us (C.F.A.) has previously reported the successful use of one of the commercially available prothrombin complex concentrates for the control of bleeding episodes of haemophiltc patients with factor VIII inhibitors. Subsequent batches of these concentrates have not proved consistently effective even in doses of 150 factor IX units/kg every 24 hours. Recently an investigational preparation, Auto Factor IX, has been made available to us. This has a stated factor VIII correctional unit assay for each batch, (based on the ability to correct the prolonged APTT of plasma containing an inhibitor of factor VIII). We used 60-120 units/kg as an IV dose every 12 or 24 hours in the treatment of 24 bleeding episodes in 8 patients with factor VIII Inhibitor. The bleeding episodes were haemarthrosis (12) soft-tissue (6) intralingual (2) lacerations (2) retroperitoneal (1) and epidural (1). Rapid easing of pain and reduction of swelling was noted in all joints and soft tissue bleeds. In the retroperitoneal bleed cessation of bleeding was demonstrated by Technetium 99 Sulfur-colloid flow study, in the patient with epidural bleeding the hematoma was shown to reduce by serial CAT scans. Response was as good as we have come to expect from similar levels of factor VIII concentrate given to patients without an inhibitor. In 23 of the 24 episodes there was a marked reduction of APTT 10 minutes after the completion of the infusion.
Origin of Soluble Crosslinked Fibrin Oligomers: An in Vitro Study
Authors: Hafter R. , Hugo R.V. , Graeff H.
Published: May 2019

In patients with DIC crosslinked high molecular fibrin derivatives (CL-HMD)are observed, which are eluted by gel filtration in the exclusion volume (MW>106 ). Characterization by PAGE revealed that their subunits are similar to crosslinked fdp X. To evaluate their origin, in vitro studies were performed on fibrinolysis products obtained in three ways; (1) by SK-induced fibrinolysis of crosslinked fibrin, (2) by simultaneous action of thrombin and plasmin on Fg in presence of F XIII and Ca++, and (3) by limited fibrinogenolysis and subsequent action of thrombin and F XIII upon the resultant early FDP. Reaction (1) resulted in low mol derivatives (LMD) only (D-D, E ), which do not complex with Fg. In contrast, reaction (2) and (3) resulted in HMD and LMD. The former are composed of Cl-‘X’ and complexes of mainly ‘X’ and ‘Y’. In reaction (3) early X precipitates when it is transformed to ‘X’ and to CL-’X’. Late X remains soluble after transition to ‘X’ and CL-’X’. The results suggest, that CL-HMD observed in patients with DIC are not derived from fibrin clots but formed from Fg under combined action of plasmin and thrombin
A New Method for the Determination of Antiplasmin and Antiactivator Activity in Plasma. The Role of these Inhibitors in Controlling the Lysis of Fibrinogen and Fibrin
Authors: Lipinski B. , Nunn T. , Gurewich V.
Published: May 2019

In order to evaluate the effect of plasma inhibitors on the lysis of fibrinogen (F) and fibrin (f) by UK and an activator derived from euglobulin, agarose (1%) plates in borate buffer (pH 7.7) containing human F (0.1%) were prepared. Fibrinolysis was measured after incubation (18h., 37°C) on plates clotted with Arvin (10u.). Fibrinogenolysis was measured using unclotted plates to which Arvin and EACA (0.01M) were added after incubation with the activators. Lytic activity was determined by measuring the clear circular zone around the wells containing the activators. In both the F and f plates, a linear relation between lysis zones and UK concentrations (0-100u/ml) was found. Inhibitors in human plasma (HP) were evaluated by incubating (15 min.) activators with HP prior to their application to the plates. This resulted in a slight (10-20%) reduction in lysis on the f plates and total inhibition of lysis on the F plates. By contrast, when plasmin was mixed with HP, the lysis zones on the F and f plates were identical. It was concluded that an antiactivator rather than an antiplasmin is responsible for the inhibition of F-lysis. These F and f agarose plates provide a practical means for the semiquantitative determination of antiactivators and antiplasmins in patient plasma.
Recurrence of Venous Thromboembolism During Continuous Intravenous Heparin Therapy
Authors: Wilson J.E. , Crotty C.M. , Bynum L.J.
Published: May 2019

We have previously reported on 100 patients with venous thromboembolism who were randomly assigned to continuous (CH) versus intermittent heparin (IH) therapy. The CH group had significantly (P<.005) higher recurrence rate (33% vs 9%) and received significantly (P<.001) lower average daily dose of heparin (26,723 vs 37,611 units/day)(Am Rev Resp Dis 117:98, 1978). To further evaluate the cause of increased recurrence with CH we have compared activated partial thromboplastin times (APTT) and Lee White clotting times (LWCT) in patients randomly assigned to control by APTT (goal of 1½-2½ times normal) versus an arbitrary dose of heparin of 15 units/kg/hr. There was no significant difference in recurrence in those controlled (7/19 or 37%) versus those receiving an arbitrary dose (4/16 or 25%) even though the latter group received on average significantly less (P˂.005) daily heparin (28,698 vs 20,437 units/day). There were no significant differences in patients with no recurrence (24 patients) vs those with recurrence (11 patients) for a number of comparisons: Average daily heparin (24,684±5007 vs 25,325±3078 units/24 hr); average APTT (60.2±25.7 vs 57.0±18.3 sec); average LWCT (31.9±11.4 vs 27.8±9.5 mn); frequency with which APTT was <1½ x normal (46% vs 48%); frequency with which LWCT was <1½ x normal (39% vs 53%). These data give no support to inadequate total daily dose of heparin as the cause for increased recurrence of venous thromboembolism during continuous intravenous heparin therapy. Therefore other possible explanations for recurrence need to be investigated.
Lipid Composition and Lipid Synthesis in Guinea Pig Megakaryocytes and Platelets
Authors: Schick E.P. , Schick P.K.
Published: May 2019

Lipid composition and lipid synthesis have been compared in guinea pig megakaryocytes and platelets. Megakaryocytes were isolated from guinea pigs to 85% purity. Lipids were extracted and were separated by thin layer chromatography. Phospholipid (PL) content was determined by measurement of lipid phosphorus, and cholesterol and fatty acids were quantitated by gas-liquid chromatography. PL composition of megakaryocytes was:

PS + PI 15.2%; SM 14.0%; PC 40.1%; PE 30. 6%. PL composition of platelets was: PS 10.1%; PI 4.5%; SM 16.5%; PC 39.5%; PE 29.6%. The cholesterol:PL ratio was 0.35 for megakaryocytes and 0.55 for platelets. The major fatty acids in the PL were: (% of total)

Megakaryocytes and platelets were incubated for 1.5 hr with 14C-acetate. Megakaryocytes incorporated acetate into cholesterol and other sterols, ceramide, and PL (0.060, 0.016 and 0.012 nmoles/105 cells). Platelets incorporated acetate into ceramide and PL (0.02 and 0.06 nmoles/109 cells) but only trace amounts into sterols. There appears to be active biosynthesis of cholesterol in megakaryocytes but not in platelets.
Comparison of Sulfinpyrazone and its Metabolites on TxB2 and PGE2 Generation By Human Platelets
Authors: Westwick J. , Webb H. , Lewis G.P.
Published: May 2019

As the prostaglandin (PG) endoperoxides and thromboxane (Tx)A2 can produce platelet aggregation and vasoconstriction, we have comparad sulfinpyrazone (SU) and its metabolites (M) with other agents in their ability to modify arachidonic acid (AA) and PGH2 metabolism in washed human platelets. Specific RIAs were used to quantify PGE2 and TxB2 production by AA-stimulated washed human platelets. Aliquots (200μl) of washed platelets (200,000 per μl) suspended in PH 7.4 tris buffer 200mM at 37°c were Pretreated with either drug or vehicle, in quintuplicate, for 4 minutes. AA (100ng) or PGH2 (40ng) was then added to the platelets which were then vortexed for 15 seconds. The reaction was stopped 4 min 45 s later by centrifugation at 15,000 g for 30 seconds. Of the 7 donors examined, 22.3±4.3 and 0.6±0.2% of the AA added wae converted to TxB2 and PGE2 respectively. The following compounds inhibited both TxB2 and PGE2 generation, with IC50 (µg/ml) of TxB2 generation, SU (4.0), sulfoxide M of SU (5.8), p-hydrory M of SU (>50), aspirin (3.2) and indomethacin (0.08). Imidazole and an imidazole derivative inhibited generation of TxB2 from AA and PGH2, with IC50 of 250 and 0.4μg/ml respectively, with an enhancement of PGE2 generation. Therefore, low concentrations of SU and M of SU inhibit TxB2 formation in whole platelete by inhibition of cyclo-oxygenase.
Glanzmann’s Thrombasthenia : Surface Labelling by Various Techniques and Analysis by Gel Electrophoresis.
Authors: McGregor J.L. , Clemetson K.J. , James E. , Dechavanne M.
Published: May 2019

The surface membrane glycoproteins of glanzmann’s thrombasthenia and normal whole platelets were labelled by techniques specific for either sugar or protein moieties. The labelled platelets were solubilized and electrophoresed in reduced or unreduced state by discontinuous SDS-polyacrylamide gel electrophoresis. Galactose oxidase + NaB3H4, labelling, showed with reduced samples 4 glycoprotein bands : a high M.W. glycoprotein and GP Ia, GP Ib, GP IIIb, more intensely labelled than with control platelets but with similar M.W. After treatment with neuraminidase + galactose oxidase + NaB3H4 to remove terminal sialic acid and label penultimate galactose residues the gels showed on both unreduced and reduced samples the absence of PG IIb and IIIa and a relatively broad and intensely labelled GPIb band compared with control platelets. The use of sodium periodate + NaB3H4, to label predominantly sialic acid moieties gave essentially the same number of GP bands in both reduced and unreduced samples as in normal platelets. Lactoperoxidase iodination showed in thrombasthenic platelets both in the reduced and unreduced states the absence of GPIIb, GPIIIa and more intensely labelled GPIb and CPIIIb than with control platelets. The combination of multilabelling and discontinuous Polyacrylamide gel system provides a reliable method for investigating the platelet surface.
Effects of Acelyl Salicylic Acid, Indomethacin, and Imidazole on Ristocetin Induced Platelet Agglutination in Glanzmann’s Thrombasthenia
Authors: Chediak J. , Maxey B.
Published: May 2019

The response of thrombasthenic platelets to ristocetin (R) is characterized by 1) slightly decreased agglutination, and 2) cycles of agglutination-disagglutination (Thromb. Hemost. 38:31, 1977). It is also known that adenosine 5’ diphosphate (ADP) inhibits R response of thrombasthenic platelets. We studied the effects of acetyl salicylic acid (ASA), indomethacin (IND) and Imidazole (IMID) in ristocetin induced platelet agglutination (RIPA) of 5 thrombasthenic patients. Each of these reagents was incubated with citrated PRP at 37°C for 15 minutes. Ristocetin was then added at concentrations known to precipitate cycles of agglutination-disagglutination (1.5 to 1.8 mg/ml PRP). The recording was followed for at least 12 minutes and the percent of RIPA was calculated as maximum response at 3 minutes considering the patient’s own PPP as 100%. Acetyl salicylic acid and IND were capable of blocking the disagglutination phase of RIPA and they increased the agglutination response, which reaches normal values (from 54% ± 3.5 SEM to 68% ± 2.4 and 75% ± 3.8 for ASA and IND, respectively). No effects were observed with IMID. These data suggest that ASA and IND-blocked the disagglutination phase and enhanced the agglutinating response of thrombasthenic platelets by blocking the activity of cyclo-oxgenase and by preventing ADP release whereas the inhibition of thromboxane synthetase by IMID had no such effects.
The Detection and Importance of Intravascular Platelet Aggregation in Surgical Shock
Authors: McCollum C.N.
Published: May 2019

Intravascular platelet aggregates (IPA) have as yet avoided detection in shocked patients hence their role in the aetiology of “shock lung” remains controversial. Screen filtration pressure (SFP) has only been shown to measure aggregates in vitro.

A modified screen filtration technique was evaluated in 43 surgical patients. The characteristics (height,slope) of the pressure wave were compared with the number of aggregates seen to occlude filter pores on scanning electron microscopy (SEM). In 80 estimations on femoral vein blood the slope of the SFP curve was utilised improving SFP/ SEM correlation to r= .93. These aggregates arise in vivo as they were rarely detected in blood from the arm and IPA levels in femoral blood were not influenced by EDTA priming of the syringe. In 36 preoperative estimations mean SFP slope was identical to that in 14 patients after minor surgery (1.5 ± SD 1.6). After major surgery in 29 patients this value was elevated at 7.1 ± 6.1 (P<.001). Seventeen of these patients with SFP slope greater than 5 suffered a mean fall in arterial P2 at 5 days post operation of 1.85 KPa (13.9 mm Hg) which was significantly greater than that in the other major cases (0.85 KPa, 6.4 mm Hg)(P <.05). SFP also correlated closely with the fall in platelet count on day 1 post operation (r= .82, P< .001).

Intravascular platelet aggregates arise in the veins of the lower limb immediately after major surgery. They can be measured by the screen filtration technique described and may be related to pulmonary dysfunction.
Characterization of Low Mololecular Weight Factor VIII.
Authors: Rock G. , Palmer D. , Kang E. , Jamieson G. , Cruickshank W.
Published: May 2019

The high molecular weight complex of Factor VIII was isolated from resolubilized cryoprecipitate by polyethylene glycol precipitation followed by chromatography on Bio Gel A15M. Upon rechromatography of this compound in buffer containing 1M NaCl and 1mM benzamidine the low molecular weight sub-unit possessing the procoagulant activity eluted at a volume of 2.3V. SDS polyacrylamide gel electrophoresis of this material in 5% acrylamide gave a single band whose Rf indicated a molecular weight of 150,000. The isoelectric point was determined to be 7.4. A peptide map of pepsin digested, I125 labelled material showed very few peptides which were radioactive and/or fluorescamine positive; as well, there was a relatively large amount of radioactive, non-fluorescamine positive material which was slow moving on pH 2.1 electrophoresis and immobile on chromatography. Amino acid analysis yielded data consistent with the presence of a small amount of protein. Carbohydrate analysis indicated a large amount of neutral hexoses, a very small amount of hexosamines and no detectable sialic acid. These results suggest that the structural features of low molecular weight Factor VIII may account for its anomalous behaviour in standard protein characterization procedures.
Increased Levels of Low Affinity Platelet Factor 4 in Plasma and Urine of Patients With Chronic Renal Failure.
Authors: Niewiarowski S. , Guzzo J. , Rao A.K. , Berman I. , James P.
Published: May 2019

Low affinity platelet factor 4 (LA-PF4) is a specific platelet secretory protein immunologically related to β-thromboglobulin and to platelet basic protein that stimulates cell growth. The level of LA-PF4 antigen was determined by specific radioimmunoassay in platelet poor plasma (PPP) and platelet rich plasma (PRP) of 17 normal individuals (NI), 9 patients on hemodialysis (HD) and 18 patients with chronic renal failure (CRF) who were not dialysed. Eight patients with glomerular filtration rate (GFR) 5-20 ml/min were included to group 1 and 10 patients with GFR 30-50 ml/min were included to group 2. Levels of LA-PF4 in ng/ml PPP were 31.9 ± 2.8 in NI, 291.8 ± 26.3 in HD, 149.4 ± 45.2 in group 1 of CRF and 103.7 ± 11.1 in group 2 of CRF. Differences between patients and NI were significant at P <0.05. After 3 hours of hemodialysis LA-PF4 increased to 505.0 ± 92.3 (P < 0.05), however, there was no changes in PPP level across the artifical kidney at one hour. The levels of LA-PF4 in PRP of patients with CRF and HD did not differ from NI. Mean LA-PF4 excretion in urine (ng/day/100mg creatinine) was 57.7 ± 6.4 (range 33.3-75.7) in 6 NI with GFR >60 ml/min and 1461.5 ± 674.6 (range 105.3-7041.6) in 10 CRF patients. In conclusion, elevation of LA-PF4 in PPP of patients with CRF and its increased urinary excretion suggest stimulation of platelet secretion and/or decreased metabolism of LA-PF4 in the kidney.
β-Thromboglobulin in Patients with Chronic Renal Failure: Effect of Hemodialysis
Authors: Green D. , Santhanam S. , Krumlovsky F.A. , del Greco F.
Published: May 2019

β-Thromboglobulin (β-TG), a protein located in the α-granules of platelets, is released into the plasma when platelets are disrupted. Since plasma β-TG is cleared by the kidney, we measured β-TG levels in normal subjects and and in patients with chronicrenal failure, using a radioimmunoassay kit (Amersham Corp.). In 24 controls, mean values were 27 ± 12 (S.D.) ng ml-l and in 24 patients, 123 ± 41 ng ml-l , P <0.001. Because hemodialysis may induce platelet damage, we examined β-TG levels in patients before and after dialysis. Although platelet counts were unchanged, plasma β-TG levels rose in all but 2 patients, with an average increase of 30 ng ml-l. That the increase in β-TG was due to platelet disruption was confirmed by (1) no change in β-TG in 3 patients having peritoneal dialysis, and (2) studies of a patient with radiation nephritis and severe thrombocytopenia (18,000 per cu mm) secondary to chemotherapy. β-TG was 12 nR ml-l and did not increase after hemodialysis. We conclude that plasma β-TG is significantly elevated in patients with chronic renal failure, and that measurement of this protein provides a sensitive indicator of platelet disruption by hemodialysis.
Binding of Dextran Sulphate to Antithrombin
Authors: Nordenman B. , Björk I.
Published: May 2019

The interaction between dextran sulphate (DS) a synthetic sulphated polysaccharide with in vitro anticoagulant activity, and antithrombin (AT) has been studied. About 90% of a commercial, molecular-size-fractionated preparation of DS bound to an AT-Sepharose column. This material was eluted by a salt gradient at a peak ionic strength of about 0.5 and was used for further studies. Difference absorption and fluorescence measurements showed that in solution an average of about 3 molecules of AT bound to each molecule of DS of the size used (~18000 daltons) with an average binding constant of 3 x 106 M-1. The changes of the spectroscopic properties of AT induced by DS were intermediate to those caused by the low-affinity and high-affinity heparin fractions. This was parallelled by the ability of DS to accelerate-the AT-thrombin reaction to a greater extent than low-affinity heparin, but not as pronounced as high-affinity heparin. DS had relatively little effect on the reaction between AT and Factor Xa, while the influence of high-affinity heparin on this reaction was similar to that on the AT-thrombin reaction. These results suggest that DS may induce a conformational change of AT which is less extensive than that caused by high-affinity heparin. This change may be sufficient to accelerate the reaction between AT and thrombin but inadequate to correspondingly affect the reaction between the inhibitor and Factor Xa.
Blood Contact Properties of Surfaces Coated with Sulphate Groups and Different Glucoseaminoglycans.
Authors: Larsson R. , Busch C. , Eriksson J-C. , Lagergren H. , Lindahl U. , Olsson P.
Published: May 2019

Quantitative measurements of platelet adhesion and activation of plasma coagultlon were performed on polyethylene (PE) and PE-modified by sulphation and by adsorption of colloidal particles containing heparin, dermatan- and heparan sulphate.

Tubings with the different surfaces were inserted as arteriovenous shunts in acute experiments on dogs with 51Cr-labelled platelets. On all the modified PE surfaces the platelet adhesion was minimal in comparison with the unmodified PE. Only the heparinized surface could prevent activation as measured by radioimmunmoassay of fibrinopeptide A.

It is concluded that surface-located sulphate groups make a surface platelet-compatible, but not necessarily non-thrombogenic. For complete non-thrombogenicity other structures in the heparin molecules than sulphate groups appear Important.
Possible Influence of Glycocalyx on Physical Properties of the Platelet Plasma Membrane.
Authors: Stewart Gwendolyn J. , Varma Kundagallore G. , Sandler Pamela , Morinelli Thomas , Niewiarowski Stefan
Published: May 2019

In blood platelets the role of surface glycoproteins as receptors for secretogogs, and enzymes is widely accepted. The possibility that these might also influence physical properties of the platelet plasma membrane and its attachment to the submembranous microfilament cortex apparently has not been considered. Studies with platelets exposed to pronase and chymotrypsin suggested this possibility. Pronase greatly reduced the PAS staining material (2 major bands in SDS disc gels). Chymotrypsin reduced the major band, but did not affect minor bands. Pronase treatment caused characteristic, massive invagination of platelet plasma membrane but limited shape change even when secretion was extensive. PGE1 inhibited secretion but not the membrane response. Chymotrypsin caused few membrane invagination (and no secretion) but did cause extensive shape change. Microtubules were present in platelets from both treatments. These observations could be explained if: (1) carbohydrate residues were bulky and attached to a peptide that transversed the lipid layer to attach to micorfilaments and (2) pronase but no chymotrypsin cleaved the peptide connecting surface glycoproteins and microfilaments, thereby releasing glycoprotein from the membrane outside and microfilaments from their connection to the membrans inside. The fluid lipid layer would then be free to flow into the cytoplasms through gaps in the uncoupled microfilament cortex.
Studies on The Function of Platelet Surface Antigens
Authors: Connellan J , Smith I. , Barlow B. , Castaldi P.A.
Published: May 2019

Heterologous antibodies to platelets and isolated membranes have influences on the response of intact platelets to aggregating stimuli. This study is concerned with identification of the active antigens in an effort to assign a functional role to specified membrane components. Antisera were produced in rabbits to membranes obtained from washed platelets. Platelets were labelled with 125I by using lactoperoxidase and DD125ISA. 4 major labelled proteins were obtained on SDS gel electrophoresis. Several of these labelled proteins reacted with the antiplatelet membrane antibody. These proteins were isolated by treating a mixture of platelet membranes with antiplatelet antibody and subsequently incubated with goat anti-rabbit IgG. Two proteins were detected in this fraction on SDS electrophoresis. IgG was purified from antisera by QAE sephadex chromatography and insolubilized on CNBr-Sepharose. Disrupted platelets or platelet membranes were exposed to the immobilized IgG in a centrifuge tube. The Sepharoae-IgG-antigen complex was sedimented, washed with Tris ph 7.5, 3M NaCl and finally Guanidine HCl. Three proteins were detected on SDS electrophoresis of the Guanidine-HCl wash. Crossover Agar gel electrophoresis was performed on platelet membranes and whole platelets solubilized in triton. Two protein reactants, with a line of partial identity, were evident when the gels were stained with Coomassie Blue. since F (ab)2 fragments isolated from the antiserum have inhibitory effects in the response to ristocetin and collagen, it is possible that the proteins under study may be involved in some platelet surface reactions.
Absence of the Complete Platelet-Specific Alloantigens Zw (PlA) On Platelets in Glanzmann’S Thrombasthenia and the Effect of Anti-Zwa Antibody on Platelet-Function
Authors: von Leeuwen E.F. , Zonneveld G.T.E. , von Riesz L.E. , Jenkins C.S.P , van Mourik J.A. , van dem Borne A.E.G.Kr.
Published: May 2019

The expression of the platelet-speciftc alloantigens on the platelets from 6 patients with Glanzmann’s Thrombasthenia (G.T.) and their nearest relatives was studied. The alloantigens Zwa (PIAl) and Zwb(PIA2) were found to be completely absent from thrombasthenic platelets while the alloantigens of the Ko-system were found to be normally expressed. The alloantigen Baka(phenotypefrequency 90.2%) was absent on the platelets from 4 studied G.T. patients. The platelets of all the family members reacted positively with anti-Zwa, negatively with antt-Zwb serum. SDS-PA gel electrophoresis of G.T. platelet membranes demonstrated a marked deficiency of the glycoproteins IIb and IIIa. Glycoprotein analysis of the platelet membranes from the family members of 3 of the 6 patients reveoled no apparent abnormalities.

Pre-incubation with anti-Zwa containing plasma strongly inhibits ADP-and collagen induced aggregation of platelets from normal Zwa homozygous individuols with a slight inhibition of the aggregation induced by ristocetin. Zwa antibodies did not affect the functions of platelets from ZWb homozygous individuals. Thus binding of Zwa antibodies induces a thrombosthenis-like state.
Is The Incidence of Deep Vein Thrombosis Following Myocardial Infarction Decreasing?
Authors: Pitney W. R. , Hickey A. , Gopinath A. , Dean S.
Published: May 2019

Between 1371 and 1973 the incidence of positive fibrinogen leg scans following acute myocardial infarction was reported to be about 30 per cent by several investigators, including ourselves. During 1977 and 1978 we conducted a trial to test the effectiveness of the antiplatelet drug, flurbiprofen (25 mg oral, 8 hourly) in preventing venous thrombosis in patients with acute myocardial infarction. A control group which received no prophylaxis and a group receiving subcutaneous heparin (sodium salt, mucous, 5000 units 8 hourly) were included. Patients in the study were representative of all admissions for myocardial infarction and severely ill patients were not excluded. Positive fibrinogen scans were recorded in 7 of the 77 control patients, 3 of 76 receiving flurbiprofen and 2 of 77 receiving heparin. The incidence of thrombosis in the control group is considerably lower than previously published figures and too small to permit comparison with the incidence in the treated groups. It appears probable that the reduced incidence is related to a recent change in the management of patients with myocardial infarction which includes physiotherapy from the time of admission, active leg exercises and early mobilization. Our experience raises the question whether prophylactic drug therapy is necessary in the majority of patients with acute myocardial infarction.
Failure of Subcutaneous Low-Dose Heparin to Prevent Arterial Embolism After Acute Myocardial Infarction(MI)
Authors: Straub P. W.
Published: May 2019

Low-dose s.c. heparin is recommended as alternative of oral anticoagulants during the hospital phase after MI. No figures are available on pulmonary embolism (PE) and arterial embolism originating from mural thrombosis is not mentioned. During 22 months 214 patients with MI were admitted to the CCU. Heparin was given in infusion (15-30000 U/24h) for 3-4 days, followed by twice daily 5000 U s.c. 5 patients had acute arterial occlusions, all while on s.c. heparin, 4 of them underwent embolectomy of the femoral artery, one had to be amputated. An additional patient had PE documented by lung scan. One patient had a drop of the platelets to 30000/mm3 at the time of femoral artery occlusion, the count normalizing after discontinuing heparin. In the Cooperative Clinical Trial of Ebert et al.(JAMA 225-724 1973) arterial embolism into the lower extremities was found in 6 of 499 untreated patients with MI, in none of 500 on oral anticoagulants. Thus, 5 episodes of arterial occlusion in our 214 consecutive patients with MI indicate that s.c. heparin does not prevent arterial thromboembolic complications. Whether occlusions are due to embolism from mural thrombus or to local thrombosis in connection with heparin-induced thrombocytopenia as possibly in one of our cases, remains to be established.
Platelet Aggregometry and Shape Change Measurement by Laser Light in Small Samples
Authors: Blasberg P. , Wurzinper L.J.
Published: May 2019

A technique is presented to measure platelet aggregation (PA) and platelet shape change (PSC) with high accuracy in small samples (100 ul) using a turbidimetric method wich a He-Ne-Laser as light source. Both, transmitted and scattered light, Is measured by two independent light sensitive elements. Transmitted light is detected by a photodiode with a sensitive area of 1 mm2 covering a space angle of Ω= 0.004 sterad. Scattered light is detected by a photoelement surrounding the photodiode which covers a space angle of U-1.4 sterad. Ar, electronic set up forms a signal, which is proportional to the ratio scattered light/scattered light + transmitted light.

The output voltage is linearly correlated to the turbidity of the suspension. The whole set up is employed with three different types of cuvettes.

1. A cuvette where through a semipermeable hollow fiber membrane different drugs can diffuse into the platelet suspensions avoiding any stirring of the sample ()

2. A flow through cuvette to measure the extent of PA in PRP samples.

3. A couette type platelet aggregometer.
Influence of Platelet Size and Morphology on Aggregation Studies
Authors: Holme S. , Murphy S.
Published: May 2019

Platelet aggregation with lOOuM ADP was studied in normals and patients with ITP, Myeloproliferative Disease (MPD), Reactive Thrombocytosis (RT), and Marrow Failure MF) using a Payton Aggregometer. The results were quantitated as changes in extinction (optical density) during aggregation and analyzed in terms of the platelet count, N0; mean platelet size by Coulter Counter, M; the extinction of platelets in PRP prior to aggregation, E0; and the extinction per platelet, e0 = E0/N0, e0 and M were close y correlated (r=.95 for normals, RT, and MF). Mean e0 and M were increased 1.64 and 1.81 fold respectively in ITP relative to normals. MPD with M values in the normal range commonly had lower e0 values than expected relative to H. Light scattering theory predicts that this may reflect a low platelet refractive index caused by abnormalities in internal platelet morphology. Maximal change in extinction following aggregation showed a high correlation with E0 (r=0.992) for normals and patients. The decrease in extinction at either 12.24 or 36 seconds after shape change (i.e. “the rate of aggregation”) increased relative to E0 in an exponential, not linear, fashion. The studies showed that platelet size and morphology had a marked influence on the extinction of PRP prior to aggregation and that changes in extinction following aggregation in large part were predictable from knowledge of e0 and N0 prior to aggregation. Apparent abnormalities in platelet aggregation with patients may thus reflect abnormalities in platelet size and morphology and not function.
Aggregation and Disaggregation Examined by Computerized Platelet Aggregation Analysis
Authors: Dayhoff R.E. , Zeller J.A. , Ledley R.S. , Rotolo L.S.
Published: May 2019

Computerized Platelet Aggregation Analysis (CPAA) quantitates free platelets and aggregates found in p.r.p. Miltiple microscopic fields of thousands of platelets are viewed and the percentage of platelets in discrete aggregate size groups is determined. Aggregation and disaggregation have been studied by CPAA (1) before, (2) during, and (3) after stimulation with ADP concentrations that produce modest, brief, and apparently totally reversible aggregation by light transmission (LT) acraregcmetry, as seen in the table.

The five normal male subjects studied all showed aggregation by CPAA, but not by LT aggregemetry, before and 10 min. after ADP stimulation. CPAA indicated, in 4 of 5 subjects that disaggregation was incomplete at 10 min, (3), as compared to before ADP (1) or lu mm. without ADP (4), CPAA demonstrated aggregation prior to ADP stimulation and showed that small changes of LT (4%) are accompanied by a loss of about 36% of the free platelets Lo aggregates, seme greater than 40 platelets in size. Both aggregation and disaggregation are quantitated by CPAA which provides information not otherwise obtainable.
Platelet Swelling in EDTA-PRP and During pH Fall in Stored Platelet Concentrates
Authors: Holme S. , Murphy S.
Published: May 2019

Changes in platelet shape and volume as produced by low temperature, various anticoagulants and during storage of platelet concentrates (PC) were studied. Platelet volume was estimated by the mean platelet size, M, as measured by Coulter counter, and by the extinction (optical density) per platelet, e, as measured by a Payton aggregometer. For fresh PRP from 31 normal donors e and M were positively correlated (r = .88). Platelet disc-to-sphere transformation was quantitated as described previously (J. Lab. CI in, Med. 92:53, 1978). A linear correlation between the degree of shape change and the apparent increase in size as reflected by M and e was found for citrated PRP exposed to low temperatures and ADP. PRP obtained from blood anticoagulated with EDTA and kept at 22°C for 1-3 hours had increases in H that exceeded what could be predicted by shape change alone and a proportionate decrease in e. Light scattering theory would predict this if cellular swelling had occurred. When PC are stored for transfusion at 22, they are commonly exposed to hypoxic conditions (Blood 46:209, 1975) which lead to a pH fall and disc-to-sphere transformation. If pH remainsistable, there is a 10% decrease in M and e after 3 days. If pH falls below 6.7, there is a progressive increase in M beyond what can be accounted for by shape change and a proportionate decrease in e. This swelling could be partially but not completely corrected by incubation in oxygenated fresh plasma at 37°C. We suggest that this swelling reflects cellular damage which results from hypoxia.
Thrombelastographic Effects of Dextran 70 on Human Blood
Authors: Kwaan H. , Wright S. , Zuckerman L. , Caprini J.A. , Vagher P.J.
Published: May 2019

The effects of dextran was studied by thrombelastography (TEG) because it can graphically depict fibrin, formation and dissolution and plate 1st-fibrin interaction during clothing. Dextran 70 in concentrations of 1-8% ware added to samples of, native whole blood (WB), recalcified whole blood (RWB), platelet-rich plasma (PRP) and platelet-poor plasma (PPP) using buffered saline as control. Dextran produced an 13% reduction in clot Stiffness (MA) with native and celite activated WB. The same native WB shewed a 23? prolongation of clotting (R) and a 24% decrease in the rate of clot formation (α), while the celite activated WB R and α were reduced by 17% and 19% respectively. However, using RWB we found only a 10% reduction in MA as a result of dextran addition, suggesting that citrating and recalcification diminished the dextran effects. With FRF (platelets >560°000 dextran did not show any significant reduction in the measured parameters, uhiU FFP gavs the greatest response with a 36% decrease in MA. Results vere similar if FRF was obtained from subjects who had taken aspirin. This indicates the main action of dextran but to be on the fibrin network rather than on platelets or the plate let-fibrin interaction. though this effect is best seen when platelet concent: rations are low. Clot lysis by urokinase or streptokinase was accelerated in the presence of dextran but was reduced by increased platelet concentrations. These results suggest a direct effect of dextran on fibrin formation and may explain the antithrombotic effect of dextran in thit defective fibrin formation occurs.
Heparin-Platelet Interaction and Effects on Platelet Aggregation
Authors: Tiffany M.L. , Penner J.A.
Published: May 2019

Confusing data exists in the literature on the effect of heparin on platelet aggregation. Clarification is achieved by the discovery that heparin, itself, produces some platelet aggregation with maximal effect a t 0.6 U/ml heparin with human PRP diluted 1:1 with PO4 buffered saline at pH 7.6. The extra stimulus of platelet activation by heparin (usually unnoticed) increases synergistically the platelet response to most aggregating agents with maximal effect also at 0.6 U/ml of added heparin. With collagen, as with thrombin, however, the addition of heparin decreases platelet aggrega tion due to specific binding of heparin. At high concentrations of heparin (25-50 U/ml) all platelet aggregation is inhibited. Excess heparin, over and above the amount that can bind to the platelets produces electrostatic shielding that prevents the negatively charged platelets from interacting. It is also possible that aggregation is reduced by a loss of fibrinogen and fibronectin from the platelet surface by the formation of soluble heparin complexes.