bluuebunny/crossref_metadata_2025_split huggingface dataset:
Longterm Treatment With Subcutaneous Heparin During Pregnancy
Authors: Hellaren M , Nygârds F 
Published: May 2019

Twenty women were treated with i.v./s.c. heparin during pregnancy because of acute thromboembolic complications (T-E) and 15 were given s.c. heparin as prophylaxis because of earlier T-E. All women injected themselves without problems. Minor allergic reactions disappeared when preservative was avoided. The therapeutic treatment was adjusted to 1.5-2 times prolongation of APTT and the prophylaxis was decided sufficient if 5-10 secs, prolongation of APTT was registered 3-4 hours postinjection. Twenty five pregnancies were uncomplicated. Six pregnancies were connected with various obstetric complications and 5 with minor bleeding complications such as wound and vaginal hematomas. Eight pregnancies were complicated by incipient prematur labour. No rethrombosis occurred in the prophylactic group but 5 of the 20 women in the therapeutic group had rethrombosis before prophylaxis had started. All children were in good health but one had low birth weight for gestational age.The level of antithrombin (AT) and platelet count were studied in 16 women and liver function was registered in 13 of them. The level of AT decreased to a mean of 55%, measured by chromogenic substrate S-2238, after 2-4 weeks s.c. therapy in the prophylactic group. In the therapeutic group an expected mean decrease to maximum 56% was noted initially during i.v./s.c. heparin treatment. In both groups the level of AT normalized during continued heparin treatment. After finished treatment all women had normal level of AT. Platelet count and liverfunction were mainly unchanged.These regimes seem adequate during pregnancy but AT ought to be analysed in order to avoid increased risk for T-E if heparin must be withdrawn or decreased. Examination for incipient prematur labour should probably be more intensive in these groups of pregnant women.
Subcutaneous Heparin In Prevention Of Disseminated Intravascular Coagulation In Patients With Serious Infections
Authors: Zawilska K , Kanamicki M , Psuja P , Sowier J , Kawczynski S , Wysocki K 
Published: May 2019

In a series of 21 patients with serious Gram-negative and Gram-positive infections, 5000u. heparin was admini- stred subcutaneously 12-hourly with the aim of reducing the incidence of disseminated intravascular coagulation.Before starting heparin therapy there were prolongation of partial thromboplastin time; moderately increased levels of fibrinogen degradation products (FDP); decreased antithranbin III (AT III) activity (measured with chromogenic substrates); and positive paracoagulaticn tests.On heparin therapy FDP decreased and platelet count and AT III increased; and there were no clinical or laboratory signs of DIC. In those who died there were no postmortem signs of intravascular fibrin deposition.19 of the 21 patients developed septic shock. These received standard therapy as well as subcutaneous heparin. 14 patients (66%) died. There were no complicaticns with heparin therapy.In serious infections prophylactic subcutaneous heparin is advisable as early as possible.
The Role Of Superoxide Dismutase(SOD) In The Platelet Functions
Authors: Kimura A , Fujimura K , Kuramoto A 
Published: May 2019

We previously reported that SOD and catalase(CAT) as well as glutathione peroxidase(GPx) exist in human platelets, which are known to protect membrane or enzyme from oxidative damage and might regulate the prostaglandin synthesis by scavenging active oxygen(O2
- H2O2 1O2, HO.),and that the compensatory high SOD activity might be important for the maintenance of normal platelet function in the cases of glutathione reductase deficiency and the cases of myeloproliferative disorders with decreased platelet CAT and/or GPx. In order to make clear the roles of SOD, further study was done by utilizing diethyldithiocarbamate(DDC); specific inhibitor of SOD.DDC inhibited the activity of platelet SOD after two hours incubation in a dose dependent manner. Platelet treated with 10-4 M of DDC inhibited the SOD activity to 86 % of control and showed the increase of platelet aggregability induced by ADP, epinephrine and collagen. The higher concentration of DDC (10-3 M) treated platelet returned to show nearly the same maximal aggregability as that of control, and platelets with l6 % residual activity (10-2 M DDC) rather showed the inhibition of aggregation. The basal malondi- aldehyde (MDA) was not changed at any concentration of DDC treated. However, N-ethylmaleimide(NEM)or thrombin-induced MDA production of DDC treated platelet showed an almost similar manner to platelet aggregability; increased at low concentration of DDC and decreased at higher concentration.These results suggested that SOD plays a regulatory role on platelet function and metabolism, possibly by affecting the pathway of prostaglandin biosynthesis.
Role Of Albumin In The Regulation Of Platelets Production
Authors: Cherbit G , Forestier F , Solé Y , Tersarkissian M H , Gaschard J C 
Published: May 2019

We measured Serum Albumin (S.A.) and Platelet Albumin (p. A.) on 144 normal individuals, 70 pregnant women (by using a Radio-Iramuno-Assay method) and platelet counts.All the data were studied according to the method of multivariate analysis on a UNIVAC 1110 computer.The aim of our study was to quantify the influence of unknown parameters involved in S.A. synthesis and P.A. content.Two distinct parameters were put forward by these experiments : First called S.A. parameter (decreased during pregnancy) second, P.A. parameter (increased during pregnancy).On the other hand we established the existence of a third parameter controlling the regulation of platelet albumin content by altering the counts of circulating platelets.The less we got platelets, the more the P.A. content was important, showing a feed back mecanisra between S.A., P.A. and platelet counts.Albumin is involved in the regulation of platelets production.
Localisation Of Thrombotic Processes With In-111 Labeled Thrombocytes
Authors: Hardeman M R , Vreeken J , van der Schoot J B 
Published: May 2019

Human platelets were labeled with In-111 oxinate in order to establish their in vivo kinetics as well as their possible use for the detection of the early events in various thrombotic, i.e. platelet consuming, processes. Autologous platelets were incubated at roomtemperature with 250-500 uCi In-111 oxinate; the labeling-efficiency was 75-90 %.In vivo survival of In-111 labeled platelets was found to be equal to that of Cr-51 labeled platelets: 8-10 days,while the in vivo recovery was 60-70 %(in the presence of a spleen) indicating that nearly all of the injected platelets were viable. Injected, not platelet-bound radio-activity disappeared rapidly from the plasma during the first day after injection; on the following days, plasma as well as urine activities were negligable.Thrombotic processes could be visualised in renal artery thrombosis, DVT, atherosclerotic and dissecting aneurysms, rejecting kidney-transplants and shunt-thrombosis. Most results correlated well with those of other techniques, i.e. angiography and clinical, histological and biochemical parameters. A false negative result, however, was found in a patient with an a.carotis thrombus, existing for longer time. Pathological accumulation of radio-activity seen at scintigraphy could always be correlated with an increased rate of disappearance of circulating radio-active platelets.Thus, using In-111 oxinate, platelets can be labeled with a high efficiency, a high in vivo recovery and maintenance of normal in vivo kinetics. These platelets are suitable for scintigraphic detection of thrombotic processes. The method seems to be limited to new, growing thrombi.
Giant (Bernard-Soulier) Platelets are Normal Sized in Circulation
Authors: Frojmovic M. M. , Milton John G. , Caen J. P. 
Published: May 2019

Bernard-Soulier Syndrome (BSS) is a platelet disorder for which one of the characteristics is the appearance of “giant” platelets on peripheral blood smears. A comparison is made between the shape distributions of platelets obtained from normal (9) and BSS (3) donors. Geometric parameters are evaluated from a cinematographic analysis of freely rotating glutaraldehyde-hardened and unfixed platelets and of platelets on blood smear. On blood smear, normal platelets have a mean diameter of 1.8 ± 0.2 μm, where 10% have a diameter greater than 2.5μm (Weiss, et al (1974). Am. J. Med. 57: 920). On the other hand, BSS platelets are significantly larger, having a mean diameter of 3.3 + 0.7/μm, with 80% having a diameter greater than 2.5μm. These observations are consistent with all published reports concerning BSS platelets and suggest donors homozygous for this disorder (Bithell, et al (1972) N. Y. Acad. Sei. 201: 145). In contrast, the freely circulating disc-form of the BSS platelet is essentially indistinguishable from a normal platelet: mean diameter and thickness of 3.2 ± 0.3μm, and 1.4 ± 0.4 μm respectively, as compared with 3.2 ± 0.3 μm and 1.1 ± 0.4 μm for normal platelets.It is concluded that the giant size of BSS platelets results from abnormal behaviour of these platelets during the preparation of the blood smear.
Anti-Inflammatory Agents which do not Inhibit Platelet Prostaglandin Synthesis
Authors: Cerskus I. , Philp R. B. 
Published: May 2019

There is overwhelming evidence to support the theory that non-steroidal anti-inflammatory drugs (NSAID) act by interfering with production of prostaglandins (PG). Since PG intermediates are intimately involved in platelet aggregation, NSAID such as aspirin (ASA) also have adverse effects on platelet function. In the present study three compounds bearing structural resemblance to ASA were investigated for effects on platelet aggregation, PG synthesis and carrageenin-induced rat paw oedema.ASA was more potent than 3-methylphthalide (3-MP) in inhibiting platelet aggregation in response to ADP and collagen. 2-Acetylbenzoic acid (ABA) inhibited aggregation only at very high doses (I50 5mM), whilst 3-propionyloxybenzoic acid (PBA) significantly potentiated aggregation. Neither ABA nor PBA, up to 5mM final concentration, affected PG synthesis from labelled precursor in platelet lysates, and 3-MP inhibited PG synthesis by only 20% at ImM, at which concentration aggregation was virtually abolished. However, 3-MP was slightly more potent than ASA in suppressing carrageenin-induced rat paw oedema, whilst ABA and ASA were of approximately equal potency. PBA had no effect.These results indicate that anti-inflammatory activity may be separated from effects on platelet function, and that the PG synthetase of platelets may differ from that involved in PG elaboration in an acute inflammatory response. The possibility that ABA and 3-MP may be selective inhibitors of the latter enzyme, cannot be excluded.
Studies on the Structure and Subunit Composition of Human Antihaemophilic Factor
Authors: Gorman J. J. 
Published: May 2019

Human antihaemophilic factor has been purified by hydroxylapatite chromatography following precipitation from plasma and gel filtration on Sepharose 6B.Application to hydroxyiapatite was in 0.02 M tris HCl (pH 7.35) – 0.14 M NaCl and after washing with 5mM phosphate (pH 6.8) – 0.1 M NaCI the antihaemophilic factor was eluted with 0. 1M phosphate (pH 6.8) – 0.1M NaCl. Factor VIII coagulant activity, factor VIII related antigen and von Willebrand factor activity eluted simultaneously.The protein(s) had a molecular weight in excess of 500,000 and multiple subunits as shown by electrophoresis in 5% acrylamide gels containing sodium dodecyl sulphate;without reduction the protein failed to enter these gels but following reduction multiple bands were observed, the major band had a molecular weight around 200,000.Thin layer peptide mapping demonstrated structural inter-relationship between the 200,000 dalton protein and three of the smaller species, however, two other unrelated smaller species were evident.It is apparent from these findings that human factor VIII may exist as multiple molecular forms due to heterogeneity of one subunit (MW around 200,000) and the molecular structure may include other smaller non-identical subunits. The structure-function relationships of these subunits remains to be elucidated.
Plasminogen Activator Release by Oral Contraceptives and Exercise
Authors: Hedlin A. M. 
Published: May 2019

Oral contraceptives are capable of inducing an increase in blood fibrinolytic activity and our study was undertaken in an attempt to determine whether this is accomplished by stimulating the release of plasminogen activator.For this study 25 women, twelve non-users and thirteen users of the oral contraceptive, Demulen, provided blood and urine samples. Samples were obtained following a one-half hour of rest (pre-exercise), and following a 5 minute interval of moderate exercise on a treadmill. Subjects were tested early in the menstrual cycle (when the oral contraceptive was withdrawn) and late in the cycle when Demulen had been used for about two weeks.Plasma plasminogen activator levels were essentially the same for the two groups, early in the cycle, with exercise causing a doubling of the pre-exercise activator level. However, late in the cycle the contraceptive users had a much higher pre-exercise activator level than the non-users, and exercise caused a three-fold increase in this level.Urine plasminogen activator levels were measured in samples obtained before and after exercise. The urine plasminogen activator levels, unlike the plasma plasminogen activator levels, showed no significant difference between non-users and users. An even more remarkable difference was that at both intervals in the cycle and in both groups the urine plasminogen activator level decreased, rather than increased, following exercise.We conclude that the oral contraceptive Demulen does stimulate the release of plasma plasminogen activator but this does not interfere with release of this activator by exercise.
Shear Rate Dependence of Platelet Adhesion to Collagenous Surfaces in Willebrand Factor-Depleted Blood
Authors: Baumgartner H. R. , Tschopp Th. B. , Meyer D. 
Published: May 2019

A platelet function defect similar to that in von Willebrand’s disease, was produced by adding to human blood an antibody raised in rabbits against human factor Vlll/Willebrand factor. The effect of this antibody (F VIII Ab) on platelet adhesion was tested in an annular perfusion chamber. Only a small adhesion defect was observed at a shear rate corresponding to that in large arteries (830 s-1) . Since bleeding usually occurs from small vessels, platelet adhesion to collagenous surfaces was investigated at higher shear rates corresponding to those in small vessels. The surfaces were exposed to human blood (l5mM citrate) at 1, 2 and 4x103 s-1 shear rate for 6,

and 3 min, respectively. Different exposure times were chosen in order to obtain in control perfusions 50 – 70 % coverage of subendothelium with platelets at each shear rate. Platelet adhesion and adhesion-induced aggregation were measured morphometrically. As compared to control, F VIII Ab inhibited adhesion to subendothelium by 15±6, 32±21, 40±10 and 90±2 % (mean ± SE) at 0.83, 1, 2 and 4x103 s-1 shear rate, respectively. The corresponding inhibition by F VIII Ab observed on the fibrillar collagen of α-chymotrypsin-digested subendothelium was 62±11, 75±20, 99±1 and 100 %. In platelet rich plasma, F VIII Ab abolished Ristocetin-, inhibited collagen- and had no effect on ADP-induced aggregation.Thus the defect in platelet adhesion to collagenous surfaces observed in Willebrand factor-depleted blood is minimal at low (venous) and maximal at high (small vessel) shear rates.
Reduction of Surface Negative Charge in Human Platelets by Ristocetin
Authors: Muraki H. , Watanabe K. , Ando Y. , Toyama K. , Hasegawa M. 
Published: May 2019

The effect of ristocetin on the platelet surface charge was examined. One part of citrated PRP or platelet suspensions was mixed with nine parts of lOμM Tris-buf f ered saline (pH 7.4) and the mixtures were incubated at 25°C with or without ristocetin. These mixtures were applied for a cell electrophoresis microscope to determine the electrophoretic mobility(EM), from which the platelet surface charge was estimated. A significant reduction in surface negative charge of platelets was observed when ristocetin was added to the mixtures. EM of non-treated and risto-cetin(lmg/ml)-treated platelets was −1.269±0.045 and −0.870±0.040 μ/sec/V/cm, respectively. A dose-response relationship was observed between platelet EM change and ristocetin concentra-tion(0.1~1.2mg/ml). The change in EM reached to the maximum within seconds. Similar reduction of EM was observed when formalin-fixed platelets were incubated with ristocetin. Heparin at concentrations(10u~100u/ml) inhibited, but protamine sulfate(0.05mg/ml) enhanced the change of EM and platelet aggregation by ristocetin. Both the ristocetin-induced aggregation and the reduction of EM were optimally observed at pH 7.3 and were inhibited at pH above 8.0. The presence of plasma component was found to be essential in the reaction mixture for this reduction of EM. EM was decreased in the presence of ristocetin proportionally with the increase in per cent of plasma in the mixture up to 10(v/v)%. The ristocetin-induced reduction in EM of platelets was not observed when normal platelets were suspended in plasma from a patient with Willebrands’ disease(EM= −1.278±0.070 μ/sec/V/cm, with ristocetin, 1mg/ml).These results strongly suggest the involvement of decreased surface negative charge in the mechanism of platelet aggregation induced by ristocetin.
Binding of Adenosine Diphosphate (ADP) to Isolated Human Platelet Membranes
Authors: Lips J. , Sixma J. J. 
Published: May 2019

Human platelet plasma membranes were isolated according to the glycerol loading technique of Barber and Jamieson. The binding of 14C ADP was studied with Millipore filtration in a Ca2+ and Mg2+ containing buffer at pH 7,4. At least two types of binding sites were found: A high affinity system with a maximum binding of 160 pMoles/mg protein and an association constant of 1,1 χ 106 M-1; and alow affinity system with a maximum binding of about 4500 pMoles/mg protein and an association constant of 0,6 χ 1θ4 M-1. The binding according to the high affinity system showed little temperature dependency (Q10 = 1,10). The pH optimum was at 7,3. Ca2+ ions were an absolute requirement for binding.Nucleoside diphosphokinase (NDPK) was found in the membrane vesicles. Evidence that this enzyme was not responsible for ADP binding was obtained. The enzyme is Mg2+ dependent and is inhibited by AMP, in contrast to ADP binding. The Q10 was 1,44.ADP binding was inhibited by ATP, IDP and β/γ-imidoadenosine triphosphate.
Nonradioactive Semi-Automated Determination of Platelet Survival Time in Man
Authors: Roncucci R. , Deperon R. , Lansen J. , Destailleur J. , Verhaeghe R. , Doumont J. , Lamhelin G. , Stalle F. Van 
Published: May 2019

Several methods have been proposed for the determination of platelet life-span. Among them the technique described by Stuart and al (l) based upon the ex-vivo assay of platelet malondialdehyde after one single oral intake of acetylsalicylic acid is receiving an increasing interest. We adapted this method for semi-automated determinations using an AutoAnalyzer system.Platelet survival time was determined with this technique in healthy volunteers as well as in patients with abnormal platelet life-span.In some instances chromium-51-determinations were also performed in order to assess the reliability of the method proposed. The results obtained are comparable for both methods and compatible with those described in the literature.
Fibrinogens of Common Laboratory Mammals - A Comparative Study
Authors: Hawker R. J. , Hawker Linda M. 
Published: May 2019

Many laboratory mammals are used as in vivo or in vitro models of haemostatic mechanisms and require readily available purified fibrinogen suitable for trace labelling. A comparative study was made on the fibrinogens extracted by a standard 45 minute procedure from man and the following common laboratory mammals: baboon, rhesus monkey, dog, cat, rabbit, guinea pig, rat and the mini-pig. The method* utilising 5.5 mis of plasma is applicable for autologous preparations and gives 60–70% yields of pure fibrinogen from all species being dependent upon the fibrinogen concentration of the starting plasma. Clottability was consistently in excess of 90% and the final solution was suitable for direct labelling with 125-lodine using Chloramine T.The fibrinogens were examined for purity on sodium dodecyl sulphate Polyacrylamide gels from more than 60 different individuals, using reduction with mercapto-ethanol to compare the subunît molecular sizes (Aα B β γ). No other proteins were detectable nor were enzymatically derived modifications. We demonstrate molecular size differences as high as 9,000 daltons between the same designated subunit within a phylogenetic order, for example, the Aasubunit of the non-human primates compared with that of man.* Hawker, R. J. and Hawker, Linda M., 1976. J. Clin. Path. 29, 495–501 .
Postoperative Increase of Heparin in Prevention of Deep Vein Thrombosis (DVT) After Total hip Replacement
Authors: Schöndorf T.H. , Hey D. 
Published: May 2019

Acetylsalicylic-lysine (ASL) and a modified low dose heparin prophylaxis were examined to prevent postoperative DVT. 71 patients over 40 years undergoing hip replacement were randomised according to odd or even year of birth. Group I: 1.8g ASL were injected i.v. after the operation and then 24 hourly for 9 days. Group II: 5 000 IE heparin were given s.c. 10 and 2 hours before operation and continued in 8 hour-intervals until the evening of the first postoperative day. Heparin was subsequently increased to 3 × 7 500 IE/24 hours. DVT was diagnosed by the 125-I-fibrinogen test; in all legs with a positive scan a venography was performed. Partial-thromboplastin time and platelet aggregation was regularily controlled.The total incidence of DVT under the heparin prophylaxis (4/58) was significantly less than under the ASL-treatment (19/33); the rate of popliteal-femoral DVT revealed a similar significant difference. DVT opposite to the operated hip and bilateral DVT developed only under the ASL-treatment. The postoperative haematocrit decrease and the amount of blood from the wound drainage of the two groups did not differ statistically. Major wound bleeding occurred under ASL in one and in two patients under heparin.ASL did not prevent DVT sufficiently, but DVT was effectively reduced by the postoperative increase of heparin in these high risk patients.