bluuebunny/crossref_metadata_2025_split huggingface dataset:
Three Abnormal Fibrinogen Variants with the Same Amino Acid Substitution (γ 275 Arg → His): Fibrinogens Bergamo II, Essen and Perugia
Authors: Reber P , Furlan M , Henschen A , Kaudewitz H , Barbui T , Hilgard P , Nenci G G , Berrettini M , Beck E A 
Published: July 2018

SummaryWe report on three unrelated individuals with the same uncommon type of dysfibrinogenemia, originating from Bergamo, Essen and Perugia. None of them showed bleeding symptoms while the Bergamo patient and members of her family presented with a thrombotic tendency. The presence of a defective fibrinogen was suggested by prolonged thrombin and rep-tilase times. Furthermore, fibrinogen concentrations of less than 0.28 g/L were determined by the functional assay whereas values of 1.5-2.4 g/L were measured by heat precipitation or electroimmunoassay. Fibrinogen was isolated by affinity chromatography on insoluble fibrin monomer. The rate of fibrinopeptide release by thrombin was normal while the fibrin polymerization reaction was strongly delayed. An abnormal peptide (γ265-310) was isolated by high-performance liquid chromatography after cyanogen bromide cleavage of the purified γ-chain of fibrinogen Bergamo II and Essen. The same peptide was also isolated following cyanogen bromide treatment of the intact fibrinogen Perugia. Sequence analyses of these peptides demonstrated the same amino acid exchange in all three fibrinogens: γ275 arginine → histidine. The described fibrinogen variants appear to possess a molecular defect which has thus far only been observed in fibrinogen Haifa.
Behaviour and Quantitation of Extrinsic (Tissue-Type) Plasminogen Activator in Human Blood
Authors: Kluft C , Jie A F H , Allen R A 
Published: July 2018

SummaryFunctional assay of extrinsic (tissue-type) plasminogen activator (EPA) in plasma on fibrin plates was evaluated. Using specific quenching antibodies, we demonstrated the method to be specific for EPA under all conditions tested. Contributions of urokinases and intrinsic activators were excluded. The quantity of EPA in blood samples, as compared with purified uterine tissue activator, shows 1 blood activator unit (BAU) to be comparable to 0.93 ng.The median values for EPA activity for healthy volunteers were: baseline, 1.9 BAU/ml (n = 123); diurnal, 5.5 BAU/ml (n = 12); DDAVP administration, 11.7 BAU/ml (n = 39); exhaustive exercise, 25 BAU/ml (n = 24); venous occlusion (15 min), 35 BAU/ml (n = 61). A large inter-individual variation in EPA activity was found, while individual baseline values tended to be constant for periods of weeks.In vitro in blood EPA activity shows a disappearance of 50% in about 90 min at 37° C; EPA activity in euglobulin fractions is stable for ≤2 hr at 37° C.A rapid decrease in EPA activity occurs in vivo, as noted after extracorporal circulation and exercise stimulation (t½ decay, 2-5 min).
Inactivation of Hepatitis B and Non-A, Non-B Viruses by Combined Use of Tween 80®, β-Propiolactone, and Ultraviolet Irradiation
Authors: Prince A M , Stephan W , Kotitschke R , Brotman B 
Published: July 2018

SummaryTo assess the sterilization efficacy of a combined Tween 80®, β-propiolactone and ultraviolet irradiation procedure applied to a FVIII preparation to which an estimated 105.9 chimpanzee infectious doses (CID50) of hepatitis B virus had been added per ml, two chimpanzees were inoculated with 10 ml each of treated and untreated preparations. The untreated preparation, which was obtained from donors with normal alanine aminotransferase (ALT) levels, induced non-A, non-B hepatitis in both recipient animals, and delayed hepatitis B infection in one of these. Neither animal receiving the treated preparation developed either type of hepatitis. When subsequently challenged with the untreated material, both of the latter animals developed non-A, non-B and hepatitis B infection, proving their susceptibility to both types of infection.It was concluded that the combined procedure inactivated an estimated 106.9 CID50 of hepatitis B virus and an unknown quantity of a non-A, non-B virus.The finding of non-A, non-B virus infectivity in a pooled FVIII preparation despite careful ALT screening of plasma donors emphasizes the necessity of subjecting such preparations to sterilization procedures.
Verapamil and Collagen-Induced Platelet Reactions- Evidence for a Role for Intracellular Calcium in Platelet Activation
Authors: Han P , Boatwright C , Ardlie N G 
Published: July 2018

SummaryCalcium is considered to have an essential role in various platelet reactions. Using platelets preincubated with Chlortetracycline, a fluorescent divalent cation indicator, and suspended in a calcium free medium, it was shown that collagen-induced intracellular calcium redistribution occurred before the platelet shape change, the release reaction and thromboxane B2 formation. Verapamil, at concentrations which affect intracellular calcium movements, inhibited intracellular calcium redistribution in platelets and the subsequent collagen-induced platelet reactions. Low concentrations of the ionophore A23187 overcame the inhibitory effect of verapamil. These experiments provide evidence that intracellular calcium mobilization is involved in the activation of platelets by collagen. Furthermore, calcium may be released from different cellular pools since platelet secretion, aggregation and thromboxane B2 formation were inhibited at lower concentrations of verapamil than was the platelet shape change.
The Effect of N-6 and N-3 Polyunsaturated Fatty Acids on Hemostasis, Blood Lipids and Blood Pressure
Authors: Mortensen J Z , Schmidt E B , Nielsen A H , Dyerberg J 
Published: July 2018

SummaryDiverging results from studies of marine oil supplementation to western diets initiated the undertaking of a double-blind crossover study, with administration to healthy volunteers for 4 weeks of either 10 g of fish oil or 10 g of vegetable oil. Each oil containing approx. 40% of n-3 and n-6 polyunsaturated fatty acids (PUFA) respectively. During the n-3 PUFA period, systolic blood pressure, plasma total lipids, triglycerides and VLDL concentrations fell significantly whereas plasma antithrombin-III (AT-III) rose. Cutaneous bleeding time increased significantly. In contrast only AT-III rose during the n-6 PUFA feeding, however, more marked than during the n-3 oil period. It is concluded that a n-3 PUFA oil supplement to the western diet exerts an effect that generally is considered as beneficial in terms of the risk of developing cardiovascular diseases. It is in this respect superior to that of n-6 PUFA, stressing the necessity of a more differentiated approach to advices on dietary PUFA enrichment than presently is exerted.
Interaction of Heparin with Histidine-Rich Glycoprotein and with Antithrombin III
Authors: Lijnen H R , van Hoef B , Collen D 
Published: July 2018

SummaryThe interaction between heparin, histidine-rich glycoprotein and antithrombin III was studied in purified systems. Histidine- rich glycoprotein binds heparin and thereby interferes with its interaction with antithrombin III, resulting in neutralization of the anticoagulant activity. This interaction occurs with clinical grade heparin as well as with high affinity (for antithrombin III) heparin and with a high affinity heparin fragment with Mr. 4,300.Low affinity heparin competes with high affinity heparin for the binding to histidine-rich glycoprotein which results in an apparent increase of the anticoagulant activity of high affinity heparin.The interaction between heparin and histidine-rich glycoprotein is counteracted by Ca2+-binding anticoagulants, indicating that it is dependent on the presence of divalent metal ions. Ethylenediaminetetraacetate is a much more potent inhibitor of the interaction between heparin and histidine-rich glycoprotein than citrate.
The Effect of Thrombin on Platelet Accumulation on the Vessel Wall - Influence of Heparin and Aspirin
Authors: Dejan E , Cazenave J-P , Hatton M W C , Richardson M , Groves H M , Kinlough-Rathbone R L , Packham M A , Mustard J F 
Published: July 2018

SummaryRabbit aortae were removed from exsanguinated rabbits, washed, everted on probes, treated with thrombin, washed to remove unbound thrombin and used to measure the accumulation of 51Cr-labeled platelets in vitro. Thrombin pretreatment of normal rabbit aortae did not cause platelet accumulation on the endothelium; platelets appeared to accumulate only at sites where the subendothelium had been exposed. The quantitative data obtained with 51Cr-labelled platelets was reinforced by observations by scanning electron microscopy. 125I-labelled thrombin became associated with the endothelium and also with de- endothelialized vessels, and some of it could be displaced by high concentrations of heparin. Exposure of vessels to heparin after thrombin treatment eliminated the enhanced platelet accumulation caused by the thrombin treatment, probably because heparin displaced thrombin from the aortae, as demonstrated in experiments with 125I-thrombin. Inhibition of PGI2 production by aspirin treatment of the vessels did not enhance platelet accumulation on normal or thrombin-treated aortae. Thus, although thrombin treatment of the endothelium does not cause platelets to adhere to it, thrombin does cause increased platelet accumulation on the areas where the subendothelium is exposed or where endothelial cells are damaged.
Enkephalins Modify Granulocyte-Endothelial Interactions by Stimulating Prostacyclin Production
Authors: Boogaerts M A , Vermylen J , Deckmyn H , Roelant C , Verwilghen R L , Jacob H S , Moldow C F 
Published: July 2018

SummaryGranulocyte (PMN)-endothehal interactions have been implicated in the primary events of vascular injury and atherogenesis. We now present data which show that endogenous opioid peptides, e.g. enkephalins (ENK), dampen immune-triggered, granulocyte-induced endothelial damage by enhancing prostacyclin production. Concurrent exposure of human umbilical vein endothelial cells (HUEC) to Met55-enkephalin increased arachidonic acid (AA, 20 uM) and thrombin (T, 10 U/ml) induced 6-keto-PGF1α-release to respectively 197.2 ± 28.1% and 204.1 ± 17.8% (mean ± SEM) of base line stimulation (p < 0.025). The increases noted were significant at ENK-concentrations as low as 10-12M. Simultaneous addition of naloxone with ENK completely abolished the enhanced 6-keto-PGF1α- release. Addition of a protease resistant enkephalin analogue significantly (p <0.01 over several different concentrations) reduced PMN adherence to HUEC; concomitantly 51Cr-leakage from HUEC that had been exposed to PMN plus activated serum complement was decreased. The even further enhanced 51Cr- leakage that occurs when platelet release products (e.g. serotonin) are included is also decreased by added enkephalin. These data suggest that endogenous neurotransmitters may affect endothelial prostaglandin metabolism, and by so doing provide a protective effect during in vitro, and perhaps in vivo, PMN mediated endothelial injury. This link between neurohumoral and inflammatory systems might enhance our understanding of stress- related phenomena in inflammation and vascular diseases.
Controlled Multicenter Pilot Study of Urokinase – Heparin and Streptokinase in Deep Vein Thrombosis
Authors: van de Loo J C W , Kriessmann A , Trübestein G , Knoch K , de Swart C A M , Asbeck F , Marbet G A , Schmitt H E , Sewell A F , Duckert F , Theiss W , Ritz R 
Published: July 2018

SummaryThirty-three patients with acute iliofemoral thrombosis were randomly assigned to three treatment groups in a pilot doseranging study of thrombolytic therapy in deep vein thrombosis. One group received tissue culture urokinase in a dose of 2,200 I.U./kg/hr, and a second group in a dose of 1,100 I.U./kg/hr following a loading dose of 4,400 I.U./kg given in ten min. Urokinase was administered for 12 hr periods, alternating with 12 hr periods of heparin. A third group received an initial dose of 250,0001.U. of streptokinase in 20 min, followed by 100,000 I.U./hr. Treatment of all patients continued for three days. At the end of this period little improvement, evaluated by “blinded” interpretation of pre- and post-treatment phlebograms, was found in five out of ten of the higher-dose urokinase patients, seven out of eleven of lower-dosage urokinase patients, and six out of ten of streptokinase patients. Optional treatment for another three days showed little further improvement of urokinase-patients and moderate further improvement in the streptokinase-patients. – Neither of the 2 dosage schemes at intermittent application of urokinase appeared to be advantageous. Urokinase treated patients experienced fewer adverse reactions.
The Effects of Prostacyclin on the Coagulation of Whole Blood
Authors: Holloway D S , Zuckerman L , Vagher J P , Mockros L F 
Published: July 2018

SummaryThe effects of prostacyclin (PGI2) on mechanical properties of forming clots were investigated by testing human blood samples on a Thrombelastograph. Concentrations greater than 50 ng/ml (blood) caused a biphasic development of clot stiffness. During the first phase, PGI2 partially inhibited the platelet involvement in coagulation causing initial clot formation at a normal time but with reduced clot stiffness. The second phase occurred after neutralization of PGI2 activity and was characterized by recovery of platelet activity to produce a final clot with normal shear modulus. The duration of the inhibitory effects depended on PGI2 concentration and hematocrit. With a normal hematocrit, a PGI2 concentration of 60 ng/ml caused an inhibition for about 40 min whereas a concentration of 100 ng/ml caused inhibition for about 75 min.
Standardization of β-Thromboglobulin and Platelet Factor 4: A Collaborative Study to Investigate the Sources and Extent of Variation in the Measurement of Platelet Specific Proteins
Authors: Curtis A D , Kerry P J 
Published: July 2018

SummaryA collaborative study involving seven laboratories has been carried out to investigate the sources and extent of variation in the measurement by radioimmunoassay of β-thromboglobulin (β-TG) and platelet factor 4 (PF4). Three plasma samples, one purified β-TG sample and two purified PF4 samples were assayed against house standards for the respective antigens by each laboratory.The main source of variation of both β-TG and PF4 measurements was inter-assay (particularly for PF4). It was found that a significant component of this variation was due to the participants’ use of different preparations as house standards for β-TG and for PF4. This indicates that the first step in the standardization of β-TG and PF4 measurement should be the introduction of a reference for each.
A Collaborative Calibration Study of Reference Materials for Thromboplastins
Authors: Hermans J , van den Besselaar A M H P , Loeliger E A , van der Velde E A 
Published: July 2018

SummaryIn a collaborative study of ten laboratories performed mainly within the framework of the BCR (the European Community Bureau of Reference), five thromboplastins were calibrated against the WHO (World Health Organisation) primary international reference preparation 67/40. Of these five thromboplastins, three were BCR reference materials (BCT/099, OBT/79 and RBT/79) and two were WHO secondary international reference preparations (68/434 and 70/178). Human brain tissue type is represented by 67/40 and BCT/099; bovine type by 68/434 and OBT/79, and rabbit type by 70/178 and RBT/79.The calibration relations are expressed in terms of a linear relationship between the logarithms of the prothrombin times, measured in seconds.
The Increase of Leg Fibrinolytic Potential After Reduction of Hydrostatic Stimulus
Authors: Keber Dušan 
Published: July 2018

SummaryEleven patients were studied sequentially from the beginning of recumbency due to trauma up to the complete mobilization. The first blood sampling was performed 12 hr to 4 days after injury, the second after 12 to 33 days of recumbency and the third after one or more months of mobilization. The blood was drawn each time before and after venous occlusion of the arm and the leg for 20 min. Fibrinolytic potential was calculated as the difference between post- and preocclusion values of plasminogen activator activity, measured with the euglobulin clot lysis time (ECLT) and on fibrin plates. The results showed that fibrinolytic potential of legs after the period of recumbency was approaching that of the arms, being ten times higher as measured with ECLT and five times higher as measured on fibrin plates in comparison with the period after mobilization. It was concluded that hydrostatic pressure was the main, if not the only factor responsible for the difference in the content of plasminogen activator in veins of arms and legs and their fibrinolytic potential.
The Combining Ability of Glycoproteins IIb, IIIa and Ca2+ in EDTA-Treated Nonaggregable Platelets
Authors: Zucker Marjorie B , Varon David , Masiello Nicholas C , Karpatkin Simon 
Published: July 2018

SummaryPlatelets deprived of calcium and incubated at 37° C for 10 min lose their ability to bind fibrinogen or aggregate with ADP when adequate concentrations of calcium are restored. Since the calcium complex of glycoproteins (GP) IIb and IIIa is the presumed receptor for fibrinogen, it seemed appropriate to examine the behavior of these glycoproteins in incubated non-aggregable platelets. No differences were noted in the electrophoretic pattern of nonaggregable EDTA-treated and aggregable control CaEDTA-treated platelets when SDS gels of Triton X- 114 fractions were stained with silver. GP IIb and IIIa were extracted from either nonaggregable EDTA-treated platelets or aggregable control platelets with calcium-Tris-Triton buffer and subjected to sucrose density gradient centrifugation or crossed immunoelectrophoresis. With both types of platelets, these glycoproteins formed a complex in the presence of calcium. If the glycoproteins were extracted with EDTA-Tris-Triton buffer, or if Triton-solubilized platelet membranes were incubated with EGTA at 37° C for 30 min, GP IIb and IIIa were unable to form a complex in the presence of calcium. We conclude that inability of extracted GP IIb and IIIa to combine in the presence of calcium is not responsible for the irreversible loss of aggregability that occurs when whole platelets are incubated with EDTA at 37° C.
Transcoronary Platelet Thromboxane A2 Formation without Platelet Trapping in Patients with Coronary Stenosis - Effect of Sulphinpyrazone Treatment
Authors: Cortellaro M , Boschetti C , Antoniazzi V , Moreo G , Repetto S , Verna E , Boscarini M , Limido A , Binaghi G , Polli E E 
Published: July 2018

SummaryPlatelet count, and plasma thromboxane B2 (TXB2) and circulating platelet aggregates (CPA) were determined in the coronary sinus (CS), aortic bulb (AO) and cubital vein (V) in 21 patients with stable angina and in 6 control subjects before and after atrial pacing (AP). TXB2 measurements were repeated before and after AP in 6 of the 21 angina patients after 15 days’ sulphinpyrazone treatment. Platelet count and CPA ratio were similar in angina patients and controls at all three sampling sites and were unchanged at AP peak. In the controls, basal TXB2 values in CS, AO and V were not significantly different and were unchanged at AP peak. In the angina patients compared with the controls, basal TXB2 values in the AO, CS and V were not significantly different whereas the CS/AO TBX2 ratio was significantly higher; at AP-induced ischaemia, CS TXB2 was significantly increased and the CS/AO TXB2 ratio was increased. A weak but significant direct correlation was found between CS/ AO TXB2 ratio and coronary score. Sulphinpyrazone treatment reduced CSTXB2 levels at rest and after AP, but not the ischaemic threshold at AP.
A Rapid One-Step Immunoradiometric Assay for Factor VIII-Procoagulant Antigen Utilizing Monoclonal Antibodies
Authors: Stel H V , Veerman E C I , Huisman J G , Janssen M C , van Mourik J A 
Published: July 2018

SummaryA two-site immunoradiometric assay for factor VIII-procoagulant antigen (VIIICAg) that relies completely on monoclonal antibodies has been developed. By selecting an appropriate combination of these antibodies, it was possible to develop an assay in which the radiolabelled monoclonal antibody did not inhibit the binding of antigen to the solid-phase monoclonal antibodies. Thus, the entire test could be carried out as a one-step procedure. With this one-step assay, an amount of 0.0025 U VIIICAg/ml plasma could be detected after 4 hr of incubation, whereas 18 hr of incubation resulted in a lower limit of sensitivity of 0.0005 U VIIICAg/ml. The use of a one-step assay provides a significant advantage over the conventional two-step assay by simplifying, shortening and rendering the performance of the assay more convenient.
Perineal Trauma in a Low-risk Maternity with High Prevalence of Upright Position during the Second Stage of Labor
Authors: Peppe Mariana Vitor , Stefanello Juliana , Infante Bruna Fregonesi , Kobayashi Mauricio Tsuguio , Baraldi Claudia de Oliveira , Brito Luiz Gustavo Oliveira 
Published: July 2018

Objective Perineal trauma is a negative outcome during labor, and until now it is unclear if the maternal position during the second stage of labor may influence the risk of acquiring severe perineal trauma. We have aimed to determine the prevalence of perineal trauma and its risk factors in a low-risk maternity with a high incidence of upright position during the second stage of labor.
Methods A retrospective cohort study of 264 singleton pregnancies during labor was performed at a low-risk pregnancy maternity during a 6-month period. Perineal trauma was classified according to the Royal College of Obstetricians and Gynecologists (RCOG), and perineal integrity was divided into three categories: no tears; first/second-degree tears + episiotomy; and third and fourth-degree tears. A multinomial analysis was performed to search for associated factors of perineal trauma.
Results From a total of 264 women, there were 2 cases (0.75%) of severe perineal trauma, which occurred in nulliparous women younger than 25 years old. Approximately 46% (121) of the women had no tears, and 7.95% (21) performed mediolateral episiotomies. Perineal trauma was not associated with maternal position (p = 0.285), health professional (obstetricians or midwives; p = 0.231), newborns with 4 kilos or more (p = 0.672), and labor analgesia (p = 0.319). The multinomial analysis showed that white and nulliparous presented, respectively, 3.90 and 2.90 times more risk of presenting perineal tears.
Conclusion The incidence of severe perineal trauma was low. The prevalence of upright position during the second stage of labor was 42%. White and nulliparous women were more prone to develop perineal tears.