bluuebunny/crossref_metadata_2025_split huggingface dataset:
In Vitro Effect Of Ticlopidine On Arachidonic Acid Metabolism In Platelet Phospholipids
Authors: Chap H , Simon M F , Douste-Blazy L 
Published: July 2018

The effects of ticlopidine (Ti) on arachidonic acid (AA) metabolism in platelet phospholipids have been studied in vitro by following AA release from (14C) AA-prelabeled platelets or by measuring (14C)-AA incorporation into platelet phospholipids.In the presence of prelabeled platelets, Ti induced a release of AA essentially from phosphatidylcholine (PC) only at concentrations (10-3 M) where the drug became lytic. Incubation of cells previously lysed by sonication led to a deacylation of PC, part of the released AA being reincorporated into phosphatidylethanolamine (PE) . Under these conditions, Ti effect on PC disappeared and only a slight inhibition of AA incorporation into PE was observed.On the other hand, upon incubation of non-labeled platelets with (14C)-AA, Ti impaired the incorporation of AA into all platelet phospholipids, half maximum effect being observed under non-lytic conditions at 10-5-5.10-5 M.It is postulated that Ti inhibits the acylation reactions responsible for AA entry into glycerophospholipids. This effect might promote the release of trace amounts of AA in intact cells, which could explain the accumulation of stable, anti-aggregating prostaglandin D2 (M. Lagarde et al. Prostagl. Med. 1979, 2, 433).
Determination Of Antithrombin III In Extravasal Body Fluids By Radioimmunoassay
Authors: Bleyl H 
Published: July 2018

Detection of trace amounts of AT III need highly sensitive methods like a radioimmunoassay. Purified human AT III was radiolabeled enzymatically with the GOD/POD method. After iodination, the 125 J-AT III was purified by affinity chromatography over heparin agarose. The antibody (rabbit immunoglobulin) was adsorbed to protein A-Sepharose and covalently linked by dimethyl suberimidate. Binding capacity of the radioiodi- nated AT III was >90%. The sensitivity of the immunoassay was 20 ng/ml AT III. The intercept point (50% displacement) was at 300 ng/ml AT III. Healthy volunteers with a renal excretion of < 50 mg/24 hours total protein had an AT III excretion of 30 - 50 ug/24 hours.< 50 mg/24 hours total protein had an AT III excretion of 30 - 50 ug/24 hours.Spinal fluid within the normal range of 150 - 450 mg/1 total protein contains 0.5 - 2.5 mg/1 AT III.Patients undergoing continous ambulant peritoneal dialysis (CAPD) lost 2.5 - 12 g protein with up to 4×1.5 - 2 l dialysate. The loss of AT III was 20 - 100 ng/24 hours.
Complement Activation And C1q Binding Activity In Haemodialysis
Authors: Dodd N J , Vergani D , Turney J H , Bevis L , Weston M J 
Published: July 2018

It has been proposed that hypoxia occurring during Haemodialysis (HD) is related to complement activation by the dialysis membrane. Consequent leucocyte aggregation may then lead to pulmonary micro-embolisation. We set out to assess complement activation during HD using a new, sensitive, assay for activation fragment C3d.Twenty patients, established on long term HD had blood samples taken prior to, and after 60 and 120 minutes on dialysis. C3 and C4 were measured by conventional nephelometric assays,and C3d by a new nephelometric assay. We also measured C1q binding activity (C1qBA).Hypoxia was maximal at 60 minutes (73.9% of pre-dialysis value). Pre-dialysis C3d levels were elevated,and rose significantly on HD at 60 and 120 minutes. C3 levels were persistently low-normal. C4 levels were normal and showed no change during HD. CIqBA increased during HD representing either liberation of pre-formed immune complexes(IC), or de-novo formation of IC, perhaps related to heparinisation.C3d levels are a more sensitive indicator of complement activation than conventional complement component assays. (Previous studies have failed to demonstrate C3 or C4 depletion during HD). It is possible that HD induced complement activation may occur via the classical pathway, as a result of immune complex activity, or (more likely in view of normal C4 levels) via the alternative pathway, as a result of blood contact with the cuprophane membrane.In addition to hypoxia, complement activation and C1qBA may lead to other recognised complications of regular HD including 1. Endothelial damage, 2. Hypersplenism and 3. Thrombocytopenia.
A Simple And Rapid Method To Detect Platelet Associated IgG
Authors: Takahashi A , Ohara S , Imaoka S , Kambayashi J , Kosaki G 
Published: July 2018

Anti-platelet antibody has been generally recognized as an important etiologic factor in idiopathic thrombocytopenic purpura (ITP) and the detection of platelet associated IgG (PAIgG) is essential to establish the diagnosis and also useful to predict the clinical course. Several methods to detect PAIgG have been proposed, most of which, however, require complicated manipulation and are not practical for clinical use. This paper describes a simple and rapid method to detect PAIgG.This method was devised, utilizing the ability of staphylococcal protein A (SpA) to bind specifically to human IgG. An adhesive percentage of sample platelets to sheep red blood cells coated with SpA was calculated by enumeration of sample platelet before and after treatment. It takes only several hours to complete the assay from the drawing of blood. In a total of 37 cases including 15 cases of ITP, PAIgG was studied, using this method and Fab, anti-Fab assay of Luiken. Binding Index (an adhesive percentage) was 9.3 ± 3.8% in mormal subjects and 26.5 ± 10% in ITP patients, which differnce was statistically significant (p<0.01). Binding Index was within normal range in patients with non-immune thrombocytopenia such as liver cirrhosis or splenomegaly. A good correlation was observed between Binding Index and platelet count in ITP (r= -0.7299, p<0.01) and also between Binding Index and values of PAIgG by Fab, anti-Fab assay (r=0.8309, p<0.01).These results suggest that this new method is reliable to detect PAIgG in addition to its simplicity and rapidity and practical in clinical use.
A Rapid And Sensitive Method For The Quantitation Of Platelet Autoantibodies
Authors: Jacks F , Bradlow B A 
Published: July 2018

Autoantibodies were solubilized from washed platelets by three successive freeze thaw cycles followed by sonication for 15 seconds at maximum intensity (MSE Mk 2). The disrupted platelets were centrifuged at 30,000g for 20 minutes and the supernatant was heated at 56°C for 30 minutes followed by centrifugation at 3,000g for 5 minutes. An aliquot of the supernatant was diluted with 0,01M phosphate buffered saline pH 7.4 to give a final concentration equivalent to about 5 × 106 platelets/ml. Fifty microlitres of the diluted extract was adsorbed onto the wells of a microtitre plate by incubation at room temperature for two hours. The wells were then washed three times with 0,01M phosphate buffered saline pH 7.4 containing 0,05% Tween (Tween-PBS) and the adsorbed antiplatelet IgG reacted with 50μl of an iodine-125 labelled affinity isolated goat antihuman (heavy chain specific) IgG, specific activity ≃ 50μCi/ μg (California Antibodies) for one hour at room temperature followed by three washes with Tween-PBS. A standard curve was constructed and run in parallel, in the dose range 0,l-100ng using purified human IgG (Miles Laboratories). The separated wells were counted in an automatic gamma spectrometer (Packard 3003) and the results calculated on a desk-top computer (Hewlet-Packard 9800) using a Rodbart weighted Logit-Log transformation (f = 0,996). A relatively poor arithmetic correlation was found between whole blood platelet counts and measured platelet bound IgG (r = -0,42), whereas a better correlation was obtained using a log-log plot (r = - 0,84).The results in ng/106 platelets were - Known ATP 133,2 ± 154, other autoimmune diseases with thrombocytopenia 212,0 ± 202, non-immune thrombocytopenia 18,6 ± 4,8, normal healthy controls 11,4 ± 3.7
Interaction Of Factor XI With Activating And Non-Activating Surfaces
Authors: Mannhalter C , Schiffman S 
Published: July 2018

Recent experiments have shown that purified human factor XI and trypsin activated factor XI adsorb not only to glass but also to several plastic materials. For both kinds of material the binding site(s) has (have) been localized in the heavy chain region of the molecule. Albumin (lo mg/ml) markedly reduces adsorption to plastics but not to glass, which could indicate different binding mechanisms to glass and plastics.To help elucidate the nature of binding of factors XI and XIa to the different surfaces, three types of eluting agents have been evaluated for their ability to desorb bound factors XI and XIa -- high salt (2,4 M NaCl), a non-ionic detergent (Triton X-loo), and an anionic detergent (SDS).High salt is only effective in eluting factors XI and XIa from glass and siliconized glass, which suggests ionic binding. Triton X-loo, which can split hydrophobic bonds, desorbs factor XI from plastics (except polycarbonate) and only poorly from glass. Elution with SDS, which has both a highly charged group and a hydrophobic hydrocarbon chain, is successful on glass and plastics.We therefore conclude that the binding of factor XI to glass is the combined effect of ionic and hydrophobic binding, whereas the adsorption of factor XI to plastics is primarily hydrophobic.Activation of factor XI, certainly a major change in the protein structure, appears to increase hydrophobic bonding to glass, since activated factor XI is almost completely eluted from glass by Triton X-loo.
Kinetics Of Adsorption Of Proteins From Human Plasma Onto Foreign Surfaces
Authors: Brash J L , Uniyal S 
Published: July 2018

It is believed that adsorption of proteins is the first occurrence after blood/foreign surface contact. The composition of the protein layer, how it depends on surface properties, and how it changes with time are essentially unknown. The objective of this work was to develop data relevant to these questions. To this end, the quantities of �albumin, fibrinogen and IgG adsorbed on seven surfaces from human plasma as a function of time were measured. Human plasma (ACD anticoagulant) was diluted 1:4 with tris buffer. Purified proteins were labelled with iodine isotopes using the IC1 method and added to the plasma as tracers. Materials studied include several segmented polyether-urethanes, both hydrophilic and hydrophobic, glass, siliconized glass (SG), polystyrene (PS) and polyethylene (PE).The results may be summarized as follows: Fibrinogen: Within the 2 min to 3 h range of contact times, fibrinogen was not detected on any of the hydrophilic surfaces. On PE and SG the quantity adsorbed passed through a maximum between zero time and 2 min, then declined to near zero. Only on PS was adsorption substantial (0.4 μg cm-2) and constant with time, similar to that from a solution of fibrinogen. Albumin: Albumin was also not detected on the hydrophilic materials. In general its surface concentration when it was adsorbed (hydrophobic surfaces) was similar to that observed for solutions of albumin. IgG: IgG was detected on all surfaces. The surface concentrations were low (about 0.1 μg cm-2) compared to solution values but were generally constant with time.The following conclusions are drawn: (1) The plasma itself modifies adsorption. Therefore solution adsorption data cannot be used to predict plasma adsorption. (2) Contrary to popular belief, fibrinogen is absent or transient on most surfaces. (3) IgG appears to be ubiquitous as a component of protein layers adsorbed from Plasma.
Distribution Of Platelets In PTFE Bypass Grafts
Authors: Christenson J T , Megerman J , Hanel K C , L’Italien G J , Abbott W M , Strauss H W 
Published: July 2018

Autologous platelets labeled with Indium-lll-oxine were used to examine the thrombotic process by which small diameter bypass grafts often fail. PTFE grafts were inserted into the carotid and femoral arteries of dogs, and labeled platelets were injected. Thirteen 6 cm grafts (Group I) were harvested after 3 hrs as follows: after systemic heparinization, the graft and adjacent arterial segments were perfuse-fixed in situ, cut open longitudinally, rinsed gently in saline and counted in a well counter. The flattened specimen was then placed inside an x-ray cassette for 24-48 hrs, depending on measured total activity. Fifteen 4 cm grafts (Group II) were similarly harvested, but 4 days later. All grafts included herein were patent. The autoradiograph was developed in an automatic processor and subjected to densitometry to quantitate platelet deposition. Each graft image was divided into 3 longitudinal segments.The average density in the proximal and distal artery was zero. Significant differences (p<.01) were measured between segments within each group, and between the 2 groups. Deposition in the distal segment, compared to that in the proximal segment, was 65% greater in group II than in group I. With time, therefore, platelets were preferentially deposited toward the distal anastomosis. The tendency to form occluding thrombus is thus non-uniform along the length of PTFE bypass grafts. No dependence of platelet deposition on flow was observed; their distribution appears to be independent of flows ≥ 60 ml/min. Efforts to reduce thrombosis in current PTFE bypass grafts should focus on the influence of the distal anastomosis on blood-surface interactions within the graft.
The Heparin-Glotar Surface; Mdde Of Action And Practical Application
Authors: Olsson P , Larsson R , Lins L-E , Nilsson E 
Published: July 2018

A heparinized surface with non-thrombogenic characteristics was prepared by stabilization of an ionic heparinamine complex with glutardialdehyde. The process can be applied to a large variety of materials.The coating makes the surface platelet canpatible because np fibrinogen is adsorbed. The interaction of the surface with plasma coagulation system is based upon its ability to adsorb active coagulation enzymes (thrombin) and to promote inhibition of the adsorbed enzyme in the presence of circulating anti thrombin III. The sequence involving enzyme adsorbaticn and subsequent inhibition is regenerative. Investigations on blood vessels have revealed that the intact endotheliim exerts a similar mode of action with regard to inhibition of coagulation enzymes.When the heparin in the surface coating is substituted for glucosaminoglycans with less anticoagulant activity than heparin, the created surfaces is still platelet compatible and maintains the ability to adsorb enzyme, but loses the ability to generate inhibition of the adsorbed enzymes. Such surfaces are highly thrcmbogenic.The heparin surfaces have been tested experimentally for various applications. A heparin coated intravascular pO2 sensor was used for accurate measurements without recalibrations for several days. A non-heparinized electrode deteriorated within hours. Hemodialysis was performed on non-heparinized dogs using surface-heparinized hemodialysis set.
The Effect Of Purification On The Quarternary Structure Of Factor VIII-VWF
Authors: van Mourik J A , Over J , Hellings J A 
Published: July 2018

As an index of denaturation, the ratio of Factor VIII coagulant antigen (VIII:CAg) to Factor VIII coagulant activity (VIII:C) as measured in plasma, cryoprecipitate and cryosupernatant plasma from fresh and stored blood and in several concentrates. The ratio of VIII: CAg to VIII: C was close to unity for both cryoprecipitate and factor VIII concentrates, suggesting that VIII: CAg is lost concurrently with VIII: C during cryoprecipitation and further fractionation. Together with VIII:C, a substantial amount of VIII: CAg was recovered in the cryosupernatant. Storage of blood for 24h before processing resulted in a 30% loss of VIII: C from the separated plasma, but the level of VIII: CAg was not affected. In cryoprecipitate, prepared from this plasma, VIII: C and VIII: CAg were both 30% lower than in that prepared from fresh plasma. A corresponding rise of VIII: CAg, but not of VIII: C, in the cryosupernatant was found.Gel chromatographic analysis revealed that the rise of VIII: CAg in cryosupernatant, prepared from stored blood, was due to an increased amount of VIII: CAg that eluted after the void volume which was no longer associated with VIIIR: Ag. Such an increase in dissociated VIII: CAg was not detected in the plasma derived from stored blood prior to cryoprecipitation.It is concluded that during storage of blood molecular changes are induced in the factor VIII complex, which makes the complex more liable to dissociation during the subsequent cryoprecipitation procedure. Similarly, losses of VIII: C during further purification of the Factor VIII complex should be interpreted in terms of dissociation of the VIII: C constituent unit and not merely considered as a result of denaturation of VIII: C present in the native complex.
An Apparent Effect Of Size Distribution Of FVIIIR: Ag Multimers On Immunoradiometric Assays
Authors: Lamb M A , Reisner H M , Cooper H A , Wagner R H 
Published: July 2018

Immunoradiometric assays (IRMA) of FVIIIR: Ag from normal and certain variant VWD plasmas have suggested possible antigenic differences in the molecules. Studies reported thus far have used antibody specific for normal FVIIIR: Ag. We have further studied this question of antigenic differences using 2 populations of antibody isolated from an antisera prepared against highly purified human FVIII. Isolated IgG was labeled with [125-I]. The population of labeled IgG “specific” for variant FVIIIR: Ag was separated by immune complex formation with a VWD plasma previously shown, by 2% agarose crossed immunoelectrophoresis, to contain only the lower molecular weight multimers of FVIIIR: Ag. The “specific” labeled IgG was obtained by low pH dissociation and subsequent G-200 chromatography. [125-I] IgG “specific” for normal FVIIIR: Ag was similarly obtained after immune complex formation with pooled normal human plasma. Liquid phase IRMAs were performed using differential precipitation with ammonium sulfate or PEG to separate antigen-antibody complexes from free antibody. Using antibody “specific” for normal FVIIIR: Ag, a lack of parallelism was noted in the dose-response curves of variant plasmas as well as a decrease in maximum antibody bound, as compared to normal. Interestingly, when this antibody was absorbed with the variant VWD plasma and the remaining antibody used in IRMAs, none was bound by either variant or normal plasma.Using antibody “specific” for variant FVIIIR: Ag, a similar lack of parallelism in dose-response curves and a decrease in maximum antibody bound were observed. Therefore rather than antigenic differences as previously implied, these results suggest that the discrepancies noted in IRMAs of variant and normal plasmas are a function of the size of the FVIIIR: Ag multimers.
Tissue Extract Induced Platelet Stimulation, Primary Hemostasis And Thrombosis
Authors: Breddin K , Bender N , Kirchmaier M C 
Published: July 2018

Subcutaneous tissue, blood vessels, muscle and different organs of different species (Human, pig, dog and rat), contain an activity which within seconds transformes disk shaped platelets into sphered forms with pseudopodes (stimulated platelets) in freshly drawn citrated blood or whole blood.Morphologic platelet changes were investigated using interference contrast microscopy. Retention was measured with a modified glass bead filter.Platelet stimulation was accompanied in vitro by enhanced adhesion and enhanced aggregability. The tissue extracts did not induce platelet aggregation. The active fractions were free of thromboplastic activity. In vivo reversible platelet stimulation could be demonstrated in rat mesenteric vessels. Even in the presence of the platelet stimulating tissue extracts plgtelets retained their disklike shape if incubated at 37°C.It is likely that local release of this Hemostasis Activating Factor (HAF) from damaged cells intensely and rapidly enhances primary hemostasis in the presence of von Willebrand factor. Atheromatous material is rich in platelet stimulating activity. The role of local platelet stimulation at defective endothelial cells, vessel wall ruptures and atheromatous plaques as a trigger for thrombus formation has to be established.
Concentrations Of Several Hormons In A Factor XIII Preparation Of Placental Origin
Authors: Krämer W , Mittelstaedt G H V , Schmidt R , Heene D L 
Published: July 2018

A 13 year old male patient suffering from an inborn factor XIII deficiency was treated by a factor XIII concentrate to cure a pseudotumor at the leg. Under treatment the patient showed clinical symptoms which were regarded as notyet observed hormonal side effects. The used preparation was made of human placenta. It seemed to be instructive to analyse in this concentrate the amount of several placental hormons.Three randomised charges of this factor XIII preparation were investigated for the hormonic activity of LH, prolactin, FSH, cortisol, HPL, free oestriol, total oestriol and testosteron. All determinations were carried out by RIA. Elevated concentrations for testosteron and up to the reach of the second period of pregnancy for LH and total oestriol were found.It is necessary to pay attention to hormonal side effects in treating patients with factor XIII preparations made of placental origin.
A New Factor Control Plasma For Establishing Calibration Curves For Factor-Assay In Extrinsic And Intrinsic System
Authors: Spaethe R , Lampart A , Naumann M , Strauss J 
Published: July 2018

We present a lyophilised human plasma which is optimal for calibration curves and factor control in extrinsic as well as in intrinsic system. Comparative assays were carried out between factor control plasma and a fresh plasma pool which was frozen at -70°C from 15 normal young men. The fresh plasma pool and the factor control plasmas for the calibration curves were diluted with Owren’s veronal buffer pH 7,35 in a geometric sequence. All deficiency plasmas (American Dade, Division of American Hospital Supply Corporation) were used according to the instructions of the manufacturer. All assays were carried out by two independant investigators.For the extrinsic system Thromboplastin C and FS (American Dade) were used. With this thromboplastin the callibration curves for the fresh plasma pool and the factor control plasma showed an identical course when plotted semilogarithmically. The calibration curves for the factors II, V, VII, and X showed a good correlation to normal plasma pool.For the intrinsic system the PTT-reagent Actin (American Dade) was used. The measuring times for the calibration curves of the factor control plasma are slightly longer than of the fresh plasma pool.When factors determined in factor control plasmas are read from the fresh plasma calibration curves, the range of normal values is from 90 to 105% for the factors in extrinsic system and from 80 to 105% in intrinsic system. According to these assessments, the factor control plasma seems to be appropriate for establishing calibration curves for factor assays as well as for calibration of thromboplastin time. This is a contribution to further standardization of coagulation assays.