bluuebunny/crossref_metadata_2025_split huggingface dataset:
Closure of a Recurrent Urethrovaginal Fistula in a Girl with Cloacal Anomaly Using Deflux Injection
Authors: Said Hanan , Syed Salahuddin , Zeinelabdeen Ali , Fayez Mohamed 
Published: July 2018

AbstractIn a girl born with cloaca, both hemivaginae and rectum were located above the bladder neck, and both ureters were connected to the hemivaginae. After diverting colostomy and cystovaginoscopy on the second day of life, the repair of cloaca was performed at 10 months of age by posterior sagittal anorecto vaginoplasty (PSARVP), including laparotomy and bilateral ureteric reimplantation. Eight months after the surgery, she developed a vesicovaginal fistula, which was repaired and closed by open surgery through the bladder. Three months after this procedure, a tiny urethrovaginal fistula was noticed, which was closed at the age of 2 years using hook diathermy to refresh the edges and was then closed by Deflux injection. The proper closure of the urethrovaginal fistula was confirmed by radiology and cystoscopy 3 months after the surgery. This report shows that injection of Deflux into a tiny urethrovaginal fistula following refreshing the edges may be a valid treatment option in selected cases.
A Kinetic Model Describing the Interaction of Bovine Prothrombin Fragment 1 with Calcium Ions
Authors: Kabis Charles W , Sarasua Martha M , Gottschalk Karen E , Bourne Carolyn D , Pedersen Lee G , Jackson Craig M , Hiskey Richard G , Koehler Karl A 
Published: July 2018

SummaryA kinetic model is derived for the interaction of bovine prothrombin fragment 1 with calcium ions. The model requires binding of a minimum of two calcium ions for induction of the observed biphasic fluorescence decrease as a function of time. The model is shown to be consistent with experimental kinetic and equilibrium data by fitting theoretical curves for the biphasic fluorescence change to the data through exact solution of the nonlinear differential rate equations derived from the model. The rate constants for the binding of these two required calcium ions are calculated from the solutions as best fit parameters. The thermodynamic equilibrium constants, K1 and K2, for the binding of these two calcium ions are calculated from ratios of the forward and reverse rate constants as 0.6 × 104 and 5.4 × 104, respectively. Thus, the model correctly predicts positively cooperative calcium ion binding for at least the two calcium ions required to induce fluorescence quenching.
The Effect of Histamine (H2) Receptor Antagonists on the Fibrinolytic Activity In Vitro
Authors: Stadnicki Antoni , Kacperek Teresa 
Published: July 2018

SummaryThe effect of cimetidine and ranitidine on the fibrinolytic activity in vitro was tested. The inhibition rate of spontaneous lysis rose proportionally to the increasing drug doses. However, a similar effect was obtained with two other drugs of different chemical structures and pharmacological properties. Streptokinase activated fibrinolyse was not affected by either of the drugs at any concentration. Nor was clot formation affected in these experiment conditions.The results of the tests in vitro indicate that inhibition of euglobulin fibrinolysis by H2-receptor antagonists is not specific for these drugs and not connected with their pharmacological properties. It is possible to assume that, during therapeutic use, cimetidine and ranitidine have no antifibrinolytic effect. Possible explanation and relevance of these observations are discussed.
Binding of Fibrinogen to Cultured Bovine Endothelial Cells
Authors: Delvos Ulrich , Preissner Klaus T , Müller-Berghaus Gert 
Published: July 2018

SummaryThe binding properties of purified bovine fibrinogen to bovine aortic endothelial cells have been examined in a tissue culture system. Endothelial cells bound 125I-fibrinogen in a calcium dependent fashion. Removal of calcium by EDTA instantaneously detached most of the cell-associated fibrinogen. Binding of fibrinogen to the endothelial cells was not saturable with time and dosage. Competition studies and displacement experiments did not indicate the involvement of a specific receptor site for the fibrinogen-endothelial cell-interaction. Bovine serum albumin provided in the physiological ratio of 20:1 to fibrinogen competed as effectively as unlabelled fibrinogen for 125I-fibrinogen binding to the endothelial cells. And furthermore, internalization of cell- associated tracer into the endothelial cells that could be demonstrated in the presence of serum free medium did not occur in the presence of albumin. These data suggest that fibrinogen binding to intact bovine endothelial cells is unspecific and presumably negligible in the presence of physiological albumin concentrations.
Phosphorus Labeling of Proteins and Phospholipids in Intact Platelets in Response to pH 5.3
Authors: Mürer Erik H , Daniel James L 
Published: July 2018

SummaryPrevious studies had shown that when gel-filtered or washed human platelets were incubated at pH 5.3, the cells secreted their granule-stored materials suggesting that low pH can act as a platelet activator. We determined here whether the effects of low pH on platelet protein phosphorylation and on platelet lipid metabolism were consistent with this view. When washed human platelets were incubated for 20 min at pH 5.3 and electrophoresed on SDS-PAGE, there was a great increase in 32P-label in the 20,000 and 47,000 dalton protein bands. There was also an increase in the labeling of phosphatidic acid and a small decrease in phosphatidyl inositol. When the platelets were returned to pH 7.6, the 32P labeling of the 20,000 and 47,000 dalton bands was greatly reduced, and that of phosphatidic acid reduced to the control value, while the labeling of phosphatidyl inositol was increased above control. Incubation at pH 5.3 for 60 min gave the same pattern, but return to pH 7.6 resulted in only partial reversal of labeling of the two protein bands and little decrease in the label associated with phosphatidic acid, but the radioactivity in phosphatidyl inositol was greatly increased. The changes in the 32P-labeling of phospholipids and proteins after incubation of platelets at pH 5.3 may reflect an increase in cytoplasmic Ca++ resulting from leakage of Ca++ from intracellular storage sites, a process which becomes irreversible after longer time exposure to the low pH. The activation of human platelets at pH 5.3 is a slow process which may not be directly comparable to the fast events in the normal stimulation-response coupling, but which is accompanied by changes common to platelet activation. Most interesting in this respect is that a return to physiological conditions will reverse these events, although prolonged exposure will make them irreversible. These studies may therefore present a way to study the boundary between reversible and irreversible processes in platelets.
Quantitative and Continuous Analysis of ATP Release from Blood Platelets with Firefly Luciferase Luminescence
Authors: Higashi Terumasa , Isomoto Akio , Tyuma Itiro , Kakishita Eizo , Uomoto Michiko , Nagai Kiyoyasu 
Published: July 2018

SummaryAn analytical method was devised to determine the entire course of the adenosine-triphosphate (ATP) release from blood platelets based on a continuous measurement of firefly luciferase luminescence. The equation of the release reaction was derived after due consideration of substrate (ATP) consumption and product (oxyluciferin) inhibition on the luciferase reaction as follows: C, = vt × (Km/Vmax) × (I + It/Ki) + It where Ct is the total concentration of the released ATP at time t, vt is the velocity of the luciferase reaction at time t and is directly measured, It is the concentration of oxyluciferin at time t, and Vmax, Km and Ki are constants. C, of the gel-filtered platelet suspension (GFP) could be determined by substituting vt and It as functions of t. The effects of albumin and temperature on the reaction were also studied.
Effects of Oral Stanozolol Used in the Prevention of Postoperative Deep Vein Thrombosis on Fibrinolytic Activity
Authors: Sue-Ling H M , Davies J A , Prentice C R M , Verheijen J H , Kluft C 
Published: July 2018

SummaryPlasminogen, fibrinogen, antithrombin III, euglobulin lysis time, tissue plasminogen activator (t-PA) and fast-acting t-PA inhibitor were measured in 21 patients receiving either stanozolol (10 mg orally given for 14 days preoperatively) or subcutaneous heparin, during a continuing comparative trial in the prevention of postoperative deep vein thrombosis.Stanozolol treatment resulted in significant (p <0.01) increases between the 14th and 1st preoperative days in the plasma concentrations of plasminogen (3.4 to 4.9 Cu/ml) and antithrombin III (107% to 132%); t-PA levels did not increase significantly (6.0 to 16.0 mU/ml; p >0.1). There were significant (p <0.02) falls in fast-acting t-PA inhibitor (132% to 75%) and fibrinogen (2.4 to 1.8 g/1).Surgery reversed the changes in fibrinolytic activity seen preoperatively in the stanozolol-treated patients, and similar changes were seen in the heparin-treated group. In this dosage, stanozolol does not appear to prevent the fibrinolytic shutdown which occurs after elective major surgery.
In Vitro Studies on the Fibrinolytic, Thrombolytic and Fibrinogenolytic Properties of a Tissue Plasminogen Activator from Guinea Pig Keratocytes
Authors: Electricwala A , Ling R J , Sutton P M , Griffiths B , Riley P A , Atkinson T 
Published: July 2018

SummaryThe fibrinolytic and thrombolytic properties of a tissue plasminogen activator (tPA) purified from the conditioned medium of an established guinea pig keratocyte (GPK) cell line were investigated in in vitro systems and compared with urokinase. Using the fibrin clot lysis assay, GPK activator appears to be similar to human melanoma tPA and not to human urokinase. GPK activator also caused negligible fibrinogen breakdown, when incubated with human plasma at 37° C over 23 hr. Urokinase on the other hand caused significant fibrinogenolysis, under similar conditions. Comparison of the lysis of plasma clots by GPK activator and human urokinase have shown that GPK activator was a much more effective fibrinolytic agent than urokinase, especially at lower concentrations (<50 IU/ml). Studies on the thrombolytic effect of GPK activator on the lysis of aged and cross-linked whole human blood clots and plasma clots hanging in artificially circulating human plasma suggest that GPK activator can lyse both these types of clots equally well. The lysis is dose dependent, attaining complete lysis within 3–6 hr with the concentration of GPK activator in the range of 1–5 μg/ml plasma. It is concluded that GPK activator has a higher fibrinolytic and thrombolytic activity and lower fibrinogenolytic activity than urokinase.
A Human Pharmacological Study Comparing Conventional Heparin and a Low Molecular Weight Heparin Fragment
Authors: Bratt G , Törnebohm E , Lockner D , Bergströ G 
Published: July 2018

SummaryThe pharmacokinetics of a heparin fragment of low molecular weight (LMWH) of 4000-5000 D and unfractioned standard heparin (UFH) have been studied after i. v. injections of different doses and infusions in 8 humans.The heparin activity was significantly higher and the effect on APTT lower after LMWH fragment as compared to UFH in the same doses.The half-life of heparin activity was about 1 hr for UFH and about 2 hr for LMWH. LMWH was found to be eliminated according to first order kinetics and there were no signs of dose dependency.
The Effect of Platelet Number and Haematocrit on Whole Blood Thromboxane Synthesis
Authors: Carter A J , Hanley S P 
Published: July 2018

SummaryWhole blood, allowed to clot at 37° C in glass tubes, synthesized thromboxane A2 (TxA2) as determined by radioimmunoassay for thromboxane B2 (TxB2). The time course for TxB2 synthesis showed no further increase after 60 min and the concentration of TxB2 in serum obtained from 60 normal subjects positively correlated with the whole blood platelet count in EDTA anticoagulated blood from the same donor.Patients with chronic renal failure produced less serum TxB2 than age- and sex-matched controls; they also had lower haematocrits. After re-calculating TxB2 production as a function of platelet count and haematocrit all but one of the patients fell in the range of values obtained for controls. These results suggest that chronic renal failure may not be associated with a cyclooxygenase defect and that clotted whole blood TxB2 production should be expressed as a function of platelet count and haematocrit.
Urokinase Quality: Analysis of Different Preparations
Authors: Rogatti W , Yokoigawa K , Kobayashi T 
Published: July 2018

SummaryFive commercially available German Urokinase (UK) preparations were examined for purity, fibrinolytic activity, and molecular weight composition. With the exception of one preparation (B) all samples showed comparable fibrinolytic activity (91-107% of the activity declared). Preparations A, D, and E contained almost exclusively high-molecular-weight UK (HMW-UK), i.e., 82-86%. However, preparation C (from kidney tissue cultures) contained 95% of low-molecular-weight-UK (LMW-UK), and sample B consisted of nearly equal amounts of both HMW-UK and LMW-UK (47:53). Purity criteria (coagulative and lysozyme activity, endotoxin content, protease activity, HBS antigen) were fulfilled by preparation E, and, with certain restrictions, also by preparations A and C.
Defibrination During Warfarin Therapy in a Man with Protein C Deficiency
Authors: Francis Robert B , McGehee William G 
Published: July 2018

SummaryA 57 year old man presented with apparently spontaneous lower extremity deep vein thrombosis and pulmonary embolism. He was treated in conventional fashion with intravenous heparin and oral warfarin. After 4 daily doses of warfarin the prothrombin and proconvertin (P+P) time was within therapeutic range, and heparin was stopped. Over the next six hours complete defibrination occurred, associated with severe bleeding complications. Functional protein C measured after normalization of routine coagulation tests averaged 40% of normal, and was only 3.5% of normal immediately prior to the episode of defibrination. We conclude that the very low functional protein C levels seen immediately prior to defibrination were caused by a combination of pre-existent protein C deficiency and warfarin therapy, and directly predisposed to defibrination once heparin was stopped, despite “therapeutic” warfarin anticoagulation. Exacerbation of intravascular coagulation should be considered a potential prothrombotic effect of warfarin therapy in protein C deficient individuals.
Hereditary Protein S Deficiency and Venous Thrombo-Embolism
Authors: Broekmans A W , Bertina R M , Reinalda-Poot J , Engesser L , Muller H P , Leeuw J A , Michiels J J , Brommer E J P , Briët E 
Published: July 2018

SummaryProtein S, a vitamin K-dependent coagulation factor, is involved in the regulation of the anticoagulant activity of activated protein C.Using an immunoradiometric assay for total protein S in plasma we identified 14 patients (7 male and 7 female) in three unrelated Dutch families as fulfilling the criteria for an isolated protein S deficiency. In 9 patients who were not receiving oral anticoagulant treatment the mean total protein S antigen concentration was 0.50 ± 0.08 U/ml (± S.D.) and the calculated free protein S concentration was 0.15 ± 0.01 U/ml (± S.D.). In the five patients who were on oral anticoagulant treatment the mean total protein S antigen was 0.23 ± 0.05 U/ml (± S.D.).Seven of the 14 patients had a history of venous thromboembolism occurring at a mean age of 25 years and often without an apparent cause. Protein S deficiency is inherited as an autosomal dominant trait.
Heparin Assays and Bleeding Complications in Treatment of Deep Venous Thrombosis with Particular Reference to Retroperitoneal Bleeding
Authors: Holm H Asbjørn , Abildgaard Ulrich , Kalvenes Sigmund 
Published: July 2018

SummaryBleeding complications occurred in 30 (11%) out of 280 patients who received continuous heparin infusion for deep venous thrombosis (DVT). 22 (8%) had minor while 8 patients (3%) had major bleeding complications (1 intrathoracic [fatal], 2 gastrointestinal and 5 retroperitoneal). Heparin activity, in daily drawn blood samples, was determined by four assays (chromogenic substrate [CS] assay, activated partial thromboplastin time [APTT], thrombin time with citrated plasma [CiTT] and thrombin time with recalcified plasma [CaTT]). The differences in median heparin activity between patients with minor bleeding and patients with no bleeding did not reach significance for any of the tests. In patients with major bleeding, the differences were significant with the CS (p = .011) and the CaTT (p = .030) assays. Patients with retroperitoneal bleeding had significantly increased median activity judged by all four assays: CS (p = .002), CaTT (p = .003), APTT (p = .010), CiTT (p = .029). The difference was most pronounced after four days of heparin treatment, but there was a considerable overlap with patients without bleeding.
Endothelial Cells Produce a Lipoxygenase Derived Chemo-Repellent which Influences Platelet/Endothelial Cell Interactions – Effect of Aspirin and Salicylate
Authors: Buchanan M R , Butt R W , Magas Z , Ryn J Van , Hirsh J , Nazir D J 
Published: July 2018

SummaryWe performed experiments to determine whether endothelial cells synthesize phospholipid metabolites via the lipoxygenase pathway and whether these metabolites influence platelet/vessel wall interactions. Monolayers of cultured human endothelial cells were incubated with 14C-arachidonic acid and their cyclo-oxygenase and lipoxygenase metabolites were extracted and identified by radioimmunoassay, thin layer chromatography and high performance liquid chromatography. We found that in addition to the membrane-associated production of PGI2, endothelial cells synthesized a cytosol-associated metabolite, LOX, which was presumably derived through the lipoxygenase pathway. Inhibition of LOX was associated with an increase in PGI2 production and inhibition of PGI2 with an increase in LOX production. Under either condition, platelet adhesion to cultured endothelial cells was significantly decreased. In contrast, when both PGI2 and LOX production were inhibited, platelet adhesion to endothelial cells was enhanced. Furthermore, when LOX was bound to a thrombogenic surface, platelet adhesion was significantly decreased whereas when arachidonic acid or 12-HETE was bound to the surface, platelet adhesion was increased. We conclude that endothelial cells produce not only a cyclo-oxygenase metabolite, but also a lipoxygenase metabolite, both of which influence platelet/endothelial cell interactions.
Bioimmunoassay (BIA) of Tissue Plasminogen Activator (t-PA) and Its Specific Inhibitor (t-PA/INH)
Authors: Mahmoud M , Gaffney P J 
Published: July 2018

SummaryA bioimmunoassay (BIA) for tissue plasminogen activator (t-PA) is described which depends on the binding of t-PA and its inhibitor complexes to an immobilised IgG to t-PA and the subsequent assessment of the bound t-PA using glutamic acid- plasminogen (glu-plgn) and the chromogenic substrate, S-2251. This assay indicated that neither normal plasma nor its euglobulin precipitate contain any measurable free and functionally active t-PA. The BIA was also used to measure the level of the fast acting specific t-PA inhibitor (t-PA/INH) in plasma by assessing the residual t-PA activity in the plasma euglobulin fraction (pH 5.9), following the addition of a known amount of t-PA to the plasma.
Further Studies on the Mechanism of Action of Human Plasma in Stimulating Prostacyclin Production by Rat Smooth Muscle Cells
Authors: Vergara-Dauden Margarita , Balconi Giovanna , Breviario Ferruccio , Chiabrando Chiara , de Gaetano Giovanni , Dejana Elisabetta 
Published: July 2018

SummaryHuman normal plasma stimulates prostacyclin (PGI2) production by vascular cells. This plasma activity may be greatly modified in different pathological conditions. The purpose of this study was to characterize some aspects of the mechanism of action of plasma in modulating PGI2 release. Cultured rat aortic smooth muscle cells were used. Citrated plasma from healthy donors stimulated PGI2 production in a concentration-dependent way. Plasma-derived serum containing increasing concentrations of platelets had the same PGI2 stimulating activity as citrated plasma. Plasma stimulation of PGI2 production was accompanied by release of endogenously incorporated arachidonic acid (AA) from the cell membrane. Similarly to AA, plasma induced PGI2 synthesis only once, a second or third challenge producing a reduced response from the cells. Cells stimulated twice with plasma responded to AA like unstimulated cells while cells stimulated twice with AA were poorly responsive to subsequent stimulation with plasma. When the cells were repeatedly stimulated with AA in the presence of plasma no refractoriness was apparent.This study suggests that plasma increases PGI2 synthesis by the release of endogenous substrate from the cell membrane and by protecting the cells from self-inactivation during AA conversion to prostaglandins.
A Modification of the Wu and Hoak Method for the Determination of Platelet Aggregates and Platelet Adhesion
Authors: Bowry Sudhir K , Prentice Colin R M , Courtney J M 
Published: July 2018

SummaryThe Wu and Hoak method for determining circulating platelet aggregates has poor reproducibility; problems have been reported with the composition of the buffer systems, haemolysis, the effects of blood collection technique and a divergence of the platelet aggregate ratio in blood for healthy donors from the theoretical value of 1. Our investigations suggest that the original technique is highly operator-dependent, especially the collection of blood and the method of counting platelets after centrifugation. We describe an improved modification of the Wu and Hoak technique; a new buffer system has been developed and the proportion of blood in the buffered EDTA and buffered EDTA- formalin solutions has been altered to obtain platelet rich plasma. The platelet aggregate ratio (PAR) by this modified method for healthy donors in two different studies was 0.97 ± 0.02 and 0.98 ± 0.01 respectively. Finally, the principle of Wu and Hoak was used to measure accurately platelet adhesion, without the role of platelet-platelet interactions (aggregation). Platelet adhesion and aggregation were then used to evaluate the thrombogenicity of various artificial surfaces, including silicone rubber and polytetra- fluoroethylene (PTFE) vascular grafts.
A Multicenter Study on Amidolytic Factor X Evaluation in Oral Anticoagulant Therapy
Authors: Berthier A M , Pommereuil M , Scarabin P Y , Conard J 
Published: July 2018

SummaryFor laboratory control of oral anticoagulation, amidolytic factor X (F X) determination may offer an alternative to standardization difficulties of prothrombin time (PT). In order to validate this amidolytic assay on a large scale, a multicenter study was undertaken in 6 French laboratories using the same chromogenic substrate (Stachrom X Stago) and different automated instruments. Intra and between laboratory reproducibility of factor X was estimated on fresh and lyophilized patients plasmas and was found to be highly satisfactory. Standardization of the method did not seem to depend on the chromogenic substrate used, as investigated in two different centers. Results of PT and factor X were compared in over 500 patients on a longterm stabilized oral anticoagulant treatment: there was a strong positive correlation between the 2 tests in each center. The therapeutic range for factor X was evaluated from therapeutic PT values reported by Duckert and Marbet for the different thromboplastin reagents: the estimated mean range was 21 to 32%.Pooling the results of the six different centers a concordant information for prothrombin time and factor X amidolytic assay was found in 76% of patients and a fully discordant response was present in 0.6%. The results suggest that amidolytic factor X may be suitable for monitoring long-term anticoagulation. However, prospective trials are needed to evaluate its usefulness as compared to conventional methods.