bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Safety Of Ibuprofen In Factor VIII And IX Deficient Hemophiliacs
Authors: Inwood M J , Killackey B , Philp R B 
Published: July 2018

Most anti-inflammatory analgesics, particularly ASA, are considered contraindicated in the treatment of hemophiliacs because of inhibition of in vitro hemostatic function. Nevertheless, it would appear reasonable to use such agents in the therapy of chronic or acute hemophiliac arthropathy, provided that the anti-inflammatory drug did not increase the incidence of hemorrhage.Using moderately and severely affected factor VIII and IX deficient hemophiliacs, Ibuprofen was given, using a short (24 hrs) and long term (21 days) trial in order to assess the effect on in vitro hemostasis and the incidence of hemorrhagic symptoms compared to a comparable period prior to the ingestion of drug. An initial safety trial used 24 normal subjects and 12 moderately to severely affected factor VIII and factor IX deficient hemophiliacs. Within each group 600 mgs of Ibuprofen or lactose placebo was given in a random double-blind study. Over 24 hours no changes were seen in the bleeding time, peripheral blood counts or spontaneous bleeding patterns. Subsequently a 21 day trial was initiated with 15 moderately to severely affected hemophiliacs, using a dose of 2400 mg per os Ibuprofen per day. At 0,7,14 and 21 days, factor assays, bleeding times, platelet function and cell studies were performed. No clinically significant changes were found in any of the experimental variables, including pattern of spontaneous hemorrhages. Four of the 15 subjects experienced intermittent dyspepsia, controlled by antacids. 7 of 11 individuals with hemophilic arthropathy had a subjective decrease in symptoms from arthropathy.It is concluded that Ibuprofen is not associated with clinically significant changes in vitro or in vivo hemostatic function in factor VIII or IX deficient hemophiliacs, and should be considered in the treatment of hemophilic arthropathy.
A Genetic Variant Gf Factor IX With An Abnormal High Molecular Weight
Authors: Bertina R M , van der Linden I K 
Published: July 2018

In 1979 we reported a genetic variant of factor IX that behaved very similarly to acarboxy-factor IX (Br J Haematol 1979;42:623-35). With respect to normal FIX it showed an increased electrophoretic mobility in the presence of Ca2+ , a low specific coagulant activity, strongly reduced affinity for adsorption to AI(0H)3 and faint precipitation lines against anti-factor IX serum. These properties strongly suggested abnormal Ca2+ binding properties of this Fix-variant.The FIX-variant was isolated from the patients plasma using affinity chromatography on anti-human FIX-Sepharose. heparin-Sepharose chromatography and DEAE-Sephadex chromatography. Purification of the FIX antigen was followed by counter imunoelectrophoresis or electroimmunoassay; 50-70% of the Fix-variant was recovered in the final preparation.Analysis by SDS-PAGE revealed that the FIX-variant has an apparent MW of ca 85,000, which is much higher than that of either FIX or acarboxy-Flx (MW 63,003). After reduction two bands appear: one of 63,000 and one of 35,000. Apparently an additional polypeptide chain is associated with the FIX molecule in this variant. Incubation of the isolated FIX- variant with RVV-X, XIa or Xa does not result in cleavage of either α or β bond.The abnormal MW of the FIX-variant was also demonstrated by gel-chromatography of the patients plasma or plasma of an obligatory carrier from the patients pedigree. Using a radioimmunoassay, which is specific for the FIX-zymogen, it was found that also in plasma the FIX-variant is not ‘activated’ by XIa.It is hypothesized that the association of a FIX molecule with a 35,000 polypeptide interferes both with Ca2+ binding and with proteolytic degradation by its physiological activators.
Identification Of Variant Forms Of VIII:RAg In Von Willebrand’S Disease By Planimetric Analysis Of The 2 Die Pattern
Authors: Bone D J 
Published: July 2018

Mathematical analysis of the antigen antibody precipitin arc produced by two dimensional immunoelectrophoresis (2 DIE) was used to identify variant forms of von Willebrand’s disease (vWd).	2 DIE was performed on glass plates using rabbit precipitating antibody to human factor VIII related antigen (VIII:RAg) and barbitone electrolyte pH 8.4. After the plates had been dried and stained the results of optically standardised planimetry of the area beneath the precipitin arcs were used to plot histograms. These quantified the distribution of VIII:RAg into slow, slow intermediate, intermediate, intermediate fast, fast, and very fast mobility bands. Application of statistical analysis to the mobility bands showed a significant difference in VIII:RAg distribution from normal for each patient tested so far and between each patient (N = 30). Reproducibility was good on multiple testing of the same sample. Samples taken on different dates from the same patient revealed some variability but overall a similar distribution across the full range of mobility bands was preserved. The technique has revealed much greater variation in the phenotype of vWd than previously suspected and may be useful in classification of variants.
Prostacyclin Release In Vascular Prostheses With Regard To The Non-Thrombogenicity Of The Neo-Intima
Authors: Fritsche H M , Holzmann Th , Wendt P , Erhardt W , Maurer P C , Blümel G 
Published: July 2018

There is good evidence that internal surfacing of vascular prostheses by a non-thrombogenic biological layer is important for satisfactory long-term clinical results. However morphological and histological data obtained so far on the so called neo-intima provide little information about the anti-thrombogenic activity of the newly formed endothelium.In order to characterize the functional activity of the neo-intima we have developed a device to measure prostacyclin (PGI2) release from the vascular wall into the lumen. Different types of vascular grafts (velour knitted dacron, P.T.F.E. length 10cm, diameter 4-6mm) were placed in the carotid arteries of sheep. After removal the grafts were cut in three transverse sections (proximal, medial and distal third) and were subsequently perfused with oxygenated buffer in order to restimulate the arachidonic acid metabolism in the newly formed vascular wall. Thereafter the sections were filled with a specific volume of buffer and incubated. In the incubated solution PGI2 release was measured using a collagen and ADP induced platelet aggregation model and a 6-Keto- PGF lalpha radioimmunoassay.Within four months postoperatively PGI2 release increased especially in the proximal and distal sections of the prostheses up to the normal range, while in the medial sections of some grafts even 6 months postoperatively the PGI2 release remained weak. Simultaneous investigations obtained by scanning electron microscopy revealed that there is no clear correlation between the morphology of the newly formed endothelium lining different types of vascular prostheses and the functional activity of the neo-intima. This makes it desirable to characterize the functional activity of the neointima with regard to the non-thrombogenicity of the newly formed endothelium. Improvements in newly developed vascular prostheses can thus be quantitatively measured.
Comparison Of Human Smc From Aorta, Art. ILIACA, Vena Cava And Fetal Umbilical Cord Vein. A Tem-, Sem-, Light Microscopic And Functional Study
Authors: Thilo D G S , Heinrich D 
Published: July 2018

Do smooth muscle cells (SMC) from various human origin show the same behavior in cell culture? Are there differences between arterial, venous and fetal SMCs? Explant cultures were established from human adult aorta, art. iliaca comm., vena cava. SMCs from the umbilical cord vein and art.iliaca were harvested by the collagenase method. All cells were grown in M 199, 20 mM Hepes, 20% fetal calf serum, pen.-strept, 37°C, without CO2. After sufficient outgrowth the cells were subcultivated. At various subpassages the cells were processed for TEM, SEM. For TEM the ruthenium-red-method were applied. At different subpassages growth curves were established. Growth pattern was monitored by phase contrast microscopy and staining with fluorescent dyes.--Results: V.cava SMC grow out of the explant faster, however, show slower proliferation rate than the art. SMCs. V.cava and fetal SMCs do not show the striking hill-valley growth pattern as the art. SMCs do. From fetal to adult SMCs the cell- and nucleus size increases. The varying nucleus sizes were monitored by impulscytophotometry. These results are reported in another abstract. From the art.iliaca comm, growing SMCs with up to 10 nuclei were harvested. Art. SMCs secret large amount of granular material which is not seen in venous SMCs. All cells were negative for F-VIII-antigen in the immunfluorescence.Summary: Because of these marked differences between art. and venous SMCs from human origin evaluation of experiments with SMCs have to take this into consideration before drawing general conclusions on SMC-functions.
A Non-Invasive Method For Measuring Platelet Aggregation In Vivo
Authors: Morley J , Hoyle P M , Leyton J , Davies O J 
Published: July 2018

In experimental animals, intravenous injection of ADP produces platelet accumulation in the lungs, together with thrombocytopenia. Since platelets can be isotopically labelled without gross functional disturbance, we have sought to develop a method for measurement of aggregation and disaggregation of labelled platelets in vivo.Guinea-pig platelets are labelled with Indium-111 and injected into narcotised animals (Sagital, 37 mg/kg). Two collimated crystal scintillation probes are used to monitor the thoracic region (heart and lung) (Cl) and the vascular compartment (hind limbs) (C2). An indwelling cannula (25 SWG) is inserted into a foot vein and kept patent by small volumes of heparin (100 u/ml). Intravenous ADP (10 mg/kg) causes transient accumulation of platelets within the lung, as well as thrombocytopenia, within a two minute period. During a response, counts are monitored from both probes and retained in a dedicated microcomputer, so as to permit rapid display of results in tabular and graphical form. Usually, ninety consecutive 4 sec. counts are recorded, results being expressed both as a paired difference (C1-C2) and as a ratio (C1/C2). Repeated challenge can be made with ADP and a dose-related response is obtained over the range 10-30 mg/kg. Treatment with sulphinpyrazone or prostacyclin inhibits aggregation.
Platelet Factor 4 (PF4) Release In Vitro From Unstimulated Human Platelets
Authors: Cohen D S , Strohschein J M , Saunders R N , Cargill D I 
Published: July 2018

Human venous blood was collected (9.5:0.5) in an anticoagulant (provided in the PF4 RIA kit, Abbott Labs.) consisting of 2.5% EDTA, 0.025% adenosine and 7.0% procaine HCl. Platelet rich plasma (PRP) was stirred (900 RPM) at 37°C in a Payton aggregometer for intervals of 3, 6, 9 and 12 minutes. Unincubated aliquots of PRP were taken as the 0 time controls.A significant (p < 0.02) elevation in PF4 was observed with increasing intervals. Furthermore, from the data obtained, two populations of PF4 releasers were delineated: A high releasing (HR) group and a low releasing (LR) group. HR (n=10) displayed a baseline release of 10.3 ± 0.8 ng/ml and values of 36.1 ± 9.0 (p < 0.05 compared to baseline), 46.8 ± 8.2 (p < 0.01), 54.6 ± 7.9 (p < 0.01) and 87 ± 13.1 (p < 0.01) for the corresponding time periods. LR (n=7) exhibited significant but diminished release at each time period with a basal level of 10.1 ± 1.0 and 14.7 ± 1.4 (p < 0.05 compared to baseline), 15.3 ± 1.5 (p < 0.05), 19.7 ± 2.4 (p < 0.05) and 23.6 ± 2.0 (p < 0.01) respectively. Comparison of both populations revealed significant (p < 0.01) differences at the 6, 9 and 12 minute intervals. Total PF4 content from Triton lysed PRP displayed similar levels between groups:	360.0 ±22.6 (HR) and 380.2 ± 15.2 (LR).We conclude that an endogenous release of PF4 occurs in vitro in unstimulated human PRP even in a milieu designed to deter release. This should be a concern when PF4 values are to be assessed.
Isolation Of Plasma Membrane Vesicles Of Human Platelet By Affinity Chromatography
Authors: Kobayashi T , Sakon M , Ohno H , Kambayshi J , Kösaki G 
Published: July 2018

Platelets undergo a unique morphological changes leading to the formation of hemostatic plug. In recent years, its intermediaty metabolism has been extensively studied and the important function of plasma membrane in the platelet reaction has been recognized. The method of Barber and Jamieson has been employed in order to prepare plasma membrane vesicles of platelet of excellent quality but it is rather time consuming and the yield is relatively low. In this study, an attempt was made to isolate plasma membrane vesicles of human platelets by wheat germ agglutinin affinity chromatography.Freshly collected human citrated blood was subjected to glycerol loading and hypotonic lysis to obtain lysed platelet suspension. Then, it was applied to the affinity chromatography and the fraction of plasma membrane vesicles was eluted by 0.2 M N-acetyl glucosamine. Electron micrograph of the fraction showed round membrane vesicles with some scattered intracellular organelles. Several marker enzymes were assayed in the fraction. No appreciable amount of β-glucuronidase or cytochrome c oxidase was detected in the fraction, indicating no contamination of mitochondria or α-granules. Relatively high activity of G-6-Pase was detected, suggesting possible contamination of endoplasmic reticulum. The yield was 11.6% in dry weight and 7.9% in protein.By this method, the isolation was much faster than the centrifugal method and as low as 20 ml of human citrated whole blood may be used as starting material. Upon characterization of the plasma membrane fraction by electron microscopy and marker enzyme assays, the quality of the fraction was found comparable with the centrifugal method. The yield by this method was approximately two times higher than by the conventional method.
The Infusion Study Of Neuraminidase: An Animal Model For The Study On Disialylation Of Platelet And Thrombosis
Authors: Meguro T , Yamada K , Miyaji Y , Inagaki M 
Published: July 2018

In order to detect the influence of neuraminidase on thrombotic tendency, the infusion studies of neuraminidase were carried out in animal experiments. Recent studies in our laboratories has revealed higher activity of neuraminidase in plasma during acute stages of some inflammatory diseases in which thrombosis tended to be noticed with complications. New Zealand rabbit (N.Z.W.) were used for the animal experiments. Cl. Perfrigens type V or VI of neuraminidase (Sigma) was dissolved in saline and infused to the rabbits intravenously. In one group, one infusion of neuraminidase ranged from 0.5 U per kg to 1.0 U per kg per body weight was carried out. In other group, a continuous drip infusion with 2 U per kg of neuraminidase was given to the animal during 24 hours. In both groups, the blood specimens were obtained at every 24 hours and the examinations were sustained during more than 7 days after the infusions respectively. The neuraminidase activity of plasma was assayed by fluorescent method using synthetic substrate which was kindly made available by Dr. M. Flashner in Syracuse. The sialic acids of platelet was assayed by the method of M. A. Madoff, et al.In the group of drip infusion, hyperfibrinogenemia and leukocytosis were observed in early stage, followed by thrombocytosis and acceleration of platelet aggregation, in accordance with decreased level of sialic acids of the platelet and increased level of free sialic acids in plasma. In the group of one infusion, most animals died with episodes of thrombocytopenia. Our results conclude that the drip infusion method devised by us would be useful and more applicable in the study of disialylation of platelet and hyperaggregablity and indicated the pathophysiology of some inflammatory diseases with thrombosis, more clearly compared with the one infusion technique.
Effects Of Hemostatic Agents On Platelet Aggregation
Authors: Sawyer P N , Schwann G , Stanczewski B , Jones M T 
Published: July 2018

Several new collagen derived hemostatic agents have been introduced into the surgical armamentarium. The presumption is they produce platelet aggregation, ADP release and blood clotting through the intrinsic system.Studies of interreaction of these new hemostatic agents with both blood and platelets suggests that the type of reaction with whole blood is not known or due to primary platelet activation. Avitene interreacts in part by platelet aggregation but also by interreacting with other components in blood including fibrinogen.The available evidence with a new dissolving collagenous hemostat, “Superstat”™ indicates probable activation of the extrinsic coagulation system, directly converting prothrombin to thrombin, and fibrinogen to fibrin. Thrombin time ratios (experimental vs. control) are Superstat 1% - 0.81 ± 0.16/0.93 ± 0.06, Superstat 2% - 0.84 ± 0.11/0.93 ± 0.06, Superstat 3% - 0.61 ± 0.15/0.71 ± 0.02. Comparative studies have been completed on several other agents, among them, Kollagen Haemo. Vlies - 0.66 ± 0.1/0.71 ± 0.02, Gelfoam - 0.75 ± 0.15/0.71 ± 0.02, Surgicel - 0.73 ± 0.4/ 0.71 ± 0.02, Avitene - 0.75 ± 0.3/0.71 ± 0.02, Collatamp - 0.73 ± 0.4/0.71 ± 0.02. Derived data from thrombin times, clotting times and, when possible, platelet aggregation displays widely different rates of thrombus formation. We believe the enzymatic mechanisms for these reactions are currently only partially known.The fact that clinically useful hemostatic agents each appear to produce hemostasis by several routes, and do not all use the same route, is of extreme interest in basic thrombosis studies as well as in clinical surgery.
A Simple Method For Preparation Of Nonthrombogenic Prothrombin Complex
Authors: Wickerhauser M 
Published: July 2018

Prothrombin complex concentrate (PCC) when infused into patients may produce thrombotic episodes, presumably due to the presence of some thrombogenic material. In order to prepare a safer PCC we have investigated whether the addition of purified antithrombin III (AT III) during an early stage of the isolation process would be effective in reducing thrombogenicity as assessed by the Wessler stasis model. By our method the cryosupernatant of plasma is adsorbed with DEAE-Sephadex (1.5 g/L), the unadsorbed fraction removed, the DEAE-cake washed with 0.7-1.0 plasma volume of citrate saline, followed by elution with 0.1 plasma volume of 0.03 M citrate containing 2 M NaCl and 0.25 AT III unit/ml, at pH 6.8. The eluted PCC is then concentrated and desalted by ultrafiltration, filtered, dispensed and lyophilized.In a bench-scale experiment starting from 6 L cryosupernatant, a PCC was obtained at 43% recovery and 50-fold purification over plasma based on Factor IX activity. The recoveries of Factors II, VII and X were 44, 23 and 64% respectively. The concentrate was free of detectable thrombin and plasmin and contained about 1 unit of AT III (determined immunologically) per 25 units of Factor IX. In the Wessler stasis model this PCC was nonthrombogenic at 100 Factor IX units per kilo body weight of the rabbit. Higher doses were not tried. A control PCC prepared without the addition of AT III to the DEAE-eluting buffer was nonthrombogenic at 50, but thrombogenic at 75 Factor IX units per kilo body weight of the rabbit. Subsequent incubation with AT III did not eliminate this thrombogenicity.These results suggest that AT III can be effective in preventing thrombogenicity in PCC but not in abolishing it if already developed.
The Role Of Factor VIII: C In Fibrinogen - Fibrin Conversion
Authors: Frost T J , Lau R S 
Published: July 2018

The cascade mechanism for the coagulation pathway has prevailed since its original proposal, and subsequent observations have supported the role of thrombin on coagulation reactions other than in Fibrinogen - Fibrin conversion. In very small quantities, thrombin has been reported as increasing the activity of Factor VIII: C. We report here, observations which support a reverse proposal, namely that Factor VIII: C increases activity of thrombin in Fibrinogen - Fibrin conversion.Thrombin clotting times were performed employing human Fibrinogen solutions, fresh citrated normal platelet - poor human plasma and fresh citrated platelet - poor plasma from severely affected Hemophilia A patients, in whom Factor VIII : C assays were less than 1% in a one stage, activated partial thromboplastin time assay. A platelet aggregometer was used to assess the thrombin time, and the rate of clot formation (fibrin polymerization) was indicated by optical density change in the form of a curve, the tangent of the maximal slope of curve being equated with this clot formation rate.Results indicate that with very small concentrations of thrombin, Factor VIII: C enhances the rate of fibrin clot formation and that Factor VIII: C restores the abnormal rate of clot formation observed in severe Hemophilia A; the test system was known to be calcium-free, which ensured that activation of Factor X did not ensue. The concentration of Fibrinogen remained constant in all experiments. The observed phenomena are confirmed when employing purified fibrinogen solutions, using decreasing amounts of Factor VIII: C.
Platelet Hypersensitivity In Acute Malaria Infection (Plasmodium Falciparum) In Man
Authors: Essien E M , Ebhota M I 
Published: July 2018

We had earlier reported altered ADP-induced platelet aggregation in man during acute malaria infection. The present study sought to determine (i) whether the changes suggested platelet hypersensitivity to ADP and (ii) whether such changes occurred in vivo or in vitro.The aggregation response of platelets (as citrated PRP) to addition of ADP from thirty patients with acute malaria infection has been compared with that of 29 control i.e., non-infected subjects. The age range of the subjects in both groups varied from 2 to 70 years. These tests were performed before the patients took any drugs. With addition of l.0μM ADP to 1 ml of PRP, the mean aggregation amplitude (as % light transmission) obtained from 8 patients, 39.8±27.1% was significantly greater than that from 9 control subjects (5.2±6.7%; t = 3.51; P < 0.005). With higher ADP concentrations (2.4 - 5.0μM) similar response in 22 subjects (mean 89.1±14.9%) was also significantly greater than that in 20 controls (77.8±16.5%; t = 12.45; P < 0.02). These results suggest that during acute malaria infection in man, circulating platelets become hypersensitive to ADP in vitro. No instances of spontaneous aggregation were however observed in the patients.βTG was determined in 7 patients and 6 controls. The mean plasma βTG in the patients (208.3±15.6 ng/ml) was significantly higher than that in controls (59.2±15.7 ng/ml; t = 13.44; P <0.001). These latter results suggest that the platelets were probably activated in vivo to release the βTG. They further suggest that the hypersensitive changes noted earlier also probably occurred in vivo.It is suggested that acute malaria (P.falciparum) infection in man is probably another clinical condition associated with platelet hypersensitivity.