bluuebunny/crossref_metadata_2025_split huggingface dataset:
Efficient use of Monte Carlo: the fast correlation coefficient
Authors: Sjöstrand Henrik , Asquith Nicola , Helgesson Petter , Rochman Dimitri , Marck Steven van der 
Published: June 2018

Random sampling methods are used for nuclear data (ND) uncertainty propagation, often in combination with the use of Monte Carlo codes (e.g., MCNP). One example is the Total Monte Carlo (TMC) method. The standard way to visualize and interpret ND covariances is by the use of the Pearson correlation coefficient,

[see formula in PDF]

where x or y can be any parameter dependent on ND. The spread in the output, σ, has both an ND component, σND, and a statistical component, σstat. The contribution from σstat decreases the value of ρ, and hence it underestimates the impact of the correlation. One way to address this is to minimize σstat by using longer simulation run-times. Alternatively, as proposed here, a so-called fast correlation coefficient is used,

[see formula in PDF]

In many cases, cov(xstat; ystat) can be assumed to be zero. The paper explores three examples, a synthetic data study, correlations in the NRG High Flux Reactor spectrum, and the correlations between integral criticality experiments. It is concluded that the use of ρ underestimates the correlation. The impact of the use of ρfast is quantified, and the implication of the results is discussed.
Short-term complication rate following orthopedic surgery in a tertiary care center in Argentina
Authors: Willhuber Gaston Camino , Stagnaro Joaquin , Petracchi Matias , Donndorff Agustin , Monzon Daniel Godoy , Bonorino Juan Astoul , Zamboni Danilo Taype , Bilbao Facundo , Albergo Jose , Piuzzi Nicolas S. , Bongiovanni Santiago 
Published: June 2018

Introduction: Registration of adverse events following orthopedic surgery has a critical role in patient safety and has received increasing attention. The purpose of this study was to determine the prevalence and severity of postoperative complications in the department of orthopedic unit in a tertiary hospital.
Methods: A retrospective review from the postoperative complication registry of a cohort of consecutive patients operated in the department of orthopedic surgery from May 2015 to June 2016 was performed. Short-term complications (3 months after surgery), age gender, types of surgery (elective, scheduled urgency, non-scheduled urgency, and emergency), operative time, surgical start time (morning, afternoon or evening), American Society of Anesthesiologists score and surgeon's experience were assessed. Complications were classified based on their severity according to Dindo-Clavien system: Grade I complications do not require alterations in the postoperative course or additional treatment; Grade II complications require pharmacological treatment; Grade III require surgical, endoscopic, or radiological interventions without (IIIa) or with (IIIb) general anesthesia; Grade IV are life-threatening with single (IVa) or multi-organ (IVb) dysfunction(s), and require ICU management; and Grade V result in death of the patient. Complications were further classified in minor (Dindo I, II, IIIa) and major (Dindo IIIb, IVa, IVb and V), according to clinical severity.
Results: 1960 surgeries were performed. The overall 90-day complication rate was 12.7% (249/1960). Twenty-three complications (9.2 %) were type I, 159 (63.8%) type II, 9 (3.6%) type IIIa, 42 (16.8%) type IIIb, 7 (2.8%) type IVa and 9 (3.6%) were grade V according to Dindo-Clavien classification (DCC). The most frequent complication was anemia that required blood transfusion (27%) followed by wound infection (15.6%) and urinary tract infection (6%).
Discussion: The overall complication rate after orthopedic surgery in our department was 12.7%. The implementation of the DCC following orthopedic surgery was an important tool to measure the standard of care.
Neutrophil Secretion During Blood Coagulation: Evidence for a Prekallikrein Independent Pathway
Authors: Plow Edward F , Plescia Janet 
Published: June 2018

SummaryIn association with blood coagulation, neutrophils undergo a secretory response (Plow, J Clin Invest 69: 564, 1982) and it has been suggested that plasma kallikrein is responsible for inducing this reaction (Wachtfogel et al., J Clin Invest 72: 1672, 1983). To assess the contribution of kallikrein to this response, the capacity of normal and prekallikrein-deficient blood and plasma to support secretion has been compared utilizing elastase as a marker of secretion. Serial dilutions of prekallikrein-deficient plasma were as effective as normal plasma in supporting neutrophil release of elastase. The extent of elastase release in spontaneously clotting normal and prekallikrein-deficient blood was similar. At 37° C in whole blood or at 22° C in plasma, prekallikrein activators had the same effect in neutrophil secretion in normal and prekallikrein-deficient blood and plasma samples. Taken together, these results provide evidence for the existence of a prekallikrein independent pathway that can function as a predominant mechanism for induction of neutrophil secretion during blood coagulation.
Evidence for a Discrete Binding Protein of Plasminogen Activator Inhibitor in Plasma
Authors: Wiman Björn , Lindahl Tomas , Almqvist Åsa 
Published: June 2018

SummaryGel-filtration experiments of mixtures of functionally active and inactive forms of plasminogen activator inhibitor (PAI) with human plasma or bovine serum albumin have provided evidence for the existence of a discrete binding protein of PAI in plasma. Most likely it is a glycoprotein with a molecular weight of approximately 150,000. The data suggest that it forms a very stable complex with functionally active forms of PAI, but not with the inactive or “latent” PAI. However, the PAI activity seems not to be significantly altered by the interaction with the binding protein. Assuming that a stoichiometric complex is formed, titration experiments suggest that a pool of normal human plasma contains about 40–50 mg of PAI-binding protein liter.
Renal and Hepatic Handling of Endogenous Tissue-Type Plasminogen Activator (t-PA) and Its Inhibitor in Man
Authors: Brommer E J P , Derkx F H M , Schalekamp M A D H , Dooijewaard G , Klaauw M M v d 
Published: June 2018

AbstractIn eight male patients with normal liver and kidney function fibrinolytic components were measured in arterial blood and in renal and hepatic vein blood, obtained during catheterization for analysis of hypertension. Blood samples were collected simultaneously from veins und corresponding arteries before and 5 minutes after the completion of intravenous injection of desmopressin (DDAVP), 0.4 μg/kg body weight over a 10 minute period.DDAVP induced a rise in t-PA antigen and activity, and in von Willebrand factor, accompanied by a decrease in free PA-inhibitor level. We failed to detect a significant rise in plasma urokinase activity. The concentrations of fibrinogen, plasminogen, α2-antiplasmin, antithrombin III and coeruloplasmin did not change either.Renal production of t-PA under basal conditions was inferred from a negative arterio-venous (A-V) difference in t-PA-activity and in t-PA-antigen levels but this could not be confirmed by orthogonal regression analysis of the same data. A-V differences of other fibrinolytic factors were negligible.In the hepatic vessels a significant positive A-V difference of t-PA-activity and of t-PA-antigen levels was a uniform finding. After DDAVP, when plasma levels were elevated, the mean A-V difference was proportionally higher, consistent with a constant fractional elimination rate. Free PA-inhibitor was virtually absent from arterial blood after DDAVP, but appeared in hepatic vein blood, indicating either production of the inhibitor by the liver or dissociation of a circulating complex of t-PA and its inhibitor in the liver. The blood levels of the other investigated components did not show any change upon passage through the liver. Plotting of individual venous versus arterial levels of t-PA activity and of t-PA-antigen both before and after DDAVP injection yielded straight lines which in orthogonal regression analysis showed a slope significantly lower than unity; this was interpreted as net clearance of the activator. Clearance rate was not changed by DDAVP. Assuming a normal blood volume and hepatic blood flow in these subjects, the t½ of the disappearance of endogenous plasminogen activator over the liver can be calculated: t-PA-activity: 3.1 min, t-PA-antigen: 4.1 min. Since these figures are close to those found by others for the halfdisappearance time of t-PA from the entire circulation, it is concluded that t-PA is eliminated from the blood mainly by the liver. The t½ of disappearance of endogenous, free PA-inhibitor is about 3 times longer, in our example 10.4 minutes.
Slow Clearance of Acylated, Hybrid Thrombolytic Enzymes
Authors: Robinson Jeff H , Dodd Ian , Esmail Ashiq , Ferres Harry , Nunn Barbara 
Published: June 2018

SummaryTwo hybrid plasminogen activators, plasmin A-chair/t-PA Bchain and plasmin A-chain/u-PA B-chain have been synthestzed and purified in sufficient yield to permit measurement of clearance in small laboratory animals. Each hybrid enzyme was reversibly acylated at the active centre to allow the pharmacokinetic profile to be followed using an activity-based method without interference from plasma inhibitors. The acylated plasmin/u-PA hybrid had a clearance half-life (t½) in guinea pigs of approximately 80 min, whereas acyl u-PA had a t½ of 3 min. The pharmacokinetic profile of the acylated plasmin/t-PA hybrid was measured in guinea pigs, rats and rabbits; the half-lives in all three species were 60–80 min compared to half-lives of acylated, native t-PA that were in the range 0.5–1.0 min. Thus, plasmin A-chaincontaining, acylated hybrid enzymes are cleared some 30- to 100-fold more slowly than the acylated parent activators.
Mafenide (Sulfamylon™) Inhibits Plasmin Fibrinolytic Activity
Authors: Weisdorf Daniel J , Aldridge Jeffrey H 
Published: June 2018

SummaryInflammatory fibrinolysis by plasmin or phagocyte proteases is a major cause of skin graft failure on burn wounds where the primary adherent attachment of the skin grafts is due to the gluelike action of fibrin. We investigated the potential of mafenide acetate solution, an experimental topical antimicrobial used in treating grafted burn wounds, to modify plasmin fibrinolytic activity in vitro and, thus, its potential to alter or modify the integrity of the fibrin glue critical for skin graft viability. Immobilized 125I-fibrin monolayers were used to assay fibrinolytic activity from plasmin or from plasma activated by streptokinase or urokinase and modified by the presence of mafenide or ε-aminocaproic acid (EACA). While streptokinase-activated plasma lysed 52.7 ± 3.9% of the 125I-fibrin, this plasmin activity was more than 80% inhibitable by EACA. Mafenide acetate had no intrinsic fibrinolytic activity (1.5 ± 0.3%) nor activated plasma fibrinolytic potential (2.4 ± 0.5%), but produced significant and dose-related reduction in fibrinolytic activity (p <0.001). Other sulfonamide analogues lacking a para-methylamino reactive group had 10–100 fold less antifibrinolytic potency while lysine, like mafenide, able to compete for plasmin binding sites, could potently block fibrinolysis. Mafenide did not qualitatively alter activation of plasminogen or affect generation of complexes with α2 antiplasmin complexes. Adding mafenide only minutes following streptokinase-activated plasma or plasmin with the fibrin substrate reduced antifibrinolytic activity, supporting the conclusion that mafenide, like EACA, can modulate the interaction between fibrin and the plasmin reactive sites and thus prevent close plasmin/fibrin apposition. The union of mafenide’s potent antimicrobial activity with its antifibrinolytic potential is a fortuitous combination. The beneficial antifibrinolytic effect of mafenide may control inflammatory proteolysis, promote skin graft retention, and support wound healing.
Isolation, Identification and Pharmacokinetic Properties of Human Tissue-Type Plasminogen Activator Species: Possible Localisation of a Clearance Recognition Site
Authors: Dodd Ian , Nunn Barbara , Robinson Jeff H 
Published: June 2018

SummaryPurified preparations of recombinant tissue-type plasminogen activator (t-PA) from the recombinant Bowes melanoma cell line TRBM6 were shown to contain multiple species of plasminogen activator. Using a combination of chromatography on Sephadex G25, Sephadex G75 and Heparin Sepharose CL6B we have isolated two fibrinolytically active species, which, under nonreduced SDS PAGE, have apparent Mr = 38,000 and 56,000. Double immunodiffusion studies indicated that both species were closely related to both the t-PA B chain and t-PA itself. N-terminal sequencing identified the Mr = 38,000 species as ala160-t-PA (essentially ΔFGKI t-PA) and the Mr = 56,000 species as ser1-tyr2-gln3-glyx-cys51 t-PA (ΔF t-PA), the latter probably produced by alternative splicing of the t-PA gene. The pharmacokinetic properties of N,N dirnethy1-4-aminobenzoyl (DAB) derivatives of these activators and native t-PA were determined in the guinea pig. Whereas DAB → ΔF t-PA showed a similar, rapid plasma disappearance profile to that of DAB → t-PA, DAB → ΔFGKI t-PA was cleared significantly slower. These results suggest that a rapid clearance recognition site resides on either the growth factor or kringle 1, or both, domains of t-PA.
Effects of Ellagic Acid upon the Rabbit Fibrinolytic System
Authors: Iatridis S. G , Iatridis P. G 
Published: June 2018

SummaryThe present investigation deals with in vivo studies of possible relations of active Hageman factor (HFa) to the problems of thrombolysis. The study is based upon animal experimentation in which 40 normal, 5 dicumarolized and 5 heparinized rabbits each received ellagic acid (Elac 10-2 M) by intravenous continuous infusion at a rate of 1 ml/min for a period of 25 min. The data suggest that the Elac infusion induced in vivo activation of HF. Streptokinase (SK) injection 25 min from the start of Elac i. v. infusion failed to induce clot lysis in blood drawn one min after its injection. The phenomenon was more prominent with low (SK 250 U or 500 U) concentrations of SK. With higher concentrations, SK-induced clot lysis activity was not affected by Elac infusion.In dicumarolized and heparinized rabbits Elac infusion still counteracted the fibrinolysis activating effect of low concentration of SK. The possibility that the above described phenomenon was due to either hypercoagulability or to a non-specific inhibitory effect of Elac upon SK was explored and excluded.It is concluded that HFa and SK have the same site of action. Thus it seems that HFa may block the precursor upon which SK acts by forming a complex with it. It is stressed that activation of this precursor by HFa requires a suitable surface.
Cold Promoted Activation of Factor VII
Authors: Gjønnæs H 
Published: June 2018

SummaryThe cold promoted shortening of the thrombotest-times occuring in the plasmas of the majority of women on oral contraception or in the last trimester of pregnancy when incubated overnight at 0°–4° was investigated.The short thrombotest-times were caused by activation of factor VII in a time consuming reaction. Activation was also revealed in the intrinsic coagulation system, but the changes in the activities of coagulation factors other than factor VII were small.Comparison was made between clot promoting effects of cooling and contact, and it was concluded that while contact apparently exerted its main effect in the intrinsic system, cooling predominately activated the extrinsic plasma coagulation system.The cold promoted activation of factor VII seemed to be brought about by an activator.
Differing Procoagulant Activities in the Extracted Lipids of High and Low Density Platelet Plasma Membranes
Authors: Barber A. J , Triantaphyllopoulos D. C , Jamieson G. A 
Published: June 2018

SummaryPlatelet factor 3 activity has been examined in the high (d,1.120) and low (d,1.090) density platelet membranes obtained by the glycerol-lysis technique, and in the lipid fractions extracted from them. The following observations were made : procoagulant activity, as determined by the thromboplastin generation test, was equal in the two types of membrane and was higher than in the intracellular fractions ; the lipid fraction extracted from the low density membranes had a higher activity than that from the high density membranes; at high concentrations this extracted phospholipid had a mild anticoagulant effect. These results demonstrate functional differences between the two types of platelet membrane and favor a plasma membrane origin for platelet factor 3.
Experimental Model of Pulmonary Thrombosis in Rat
Authors: Tomikawa Munehiro , Ogawa Hidemasa , Abiko Yasushi 
Published: June 2018

SummaryExperimental pulmonary thrombosis was induced in rats by intravenous infusion of 0.7 M lactic acid at a rate of 1.4 ml/100 g/hr for 2 hr. As acidosis progressed, a hyper-coagulable state developed and microthrombi were formed predominantly in the lung, but not conspicuously in other organs. Pulmonary thrombi thus formed were composed of aggregated platelets in the initial stage, and of fibrin in later stages. They progressively dissolved and had completely disappeared 12 hr after cessation of the lactic acid infusion.During the infusion of lactic acid, the following changes were observed: progressive decreases in platelet count, fibrinogen, antiplasmin activity and fibrinolytic activity, and progressive increase in platelet adhesiveness. Plasma clotting time decreased to its shortest interval after one hour of the lactic acid infusion and remained at that level during the rest of the infusion. No fibrin degradation products (FDP) were detected.After cessation of the lactic acid infusion, these parameters, except for fibrinolytic activity, tended to return to normal gradually while FDP increased markedly. Fibrinolytic activity measured by eugolobulin lysis time remained low, suggesting depletion of vascular activator. Plasminogen level began to fall gradually 6 hr after cessation of the lactic acid infusion.These dynamic coagulo-fibrinolytic changes are discussed in relation to the morphological changes of thrombi.
The Relationship between Blood Coagulation and Thrombosis and Atherosclerosis in Man, Monkeys and Carnivores
Authors: Hawkey Christine M 
Published: June 2018

SummaryA comparative survey of the blood coagulation mechanism has been carried out in man, non-human primates and carnivores. In man, the average rate of conversion of fibrinogen to fibrin by thrombin is slightly faster and the ability of plasma to neutralise thrombin is less than in the animal species. Otherwise, in general, the activity of the clotting mechanism in monkeys and carnivores is equal to or greater than that of man. These results do not explain the increased susceptibility to spontaneous cardiovascular disease seen in the human species.
Human Blood Platelets Accumulate Radioactivity from the Dipeptides 14C-glycylglycine and 14C-glycylproline
Authors: Boullin D. J , Heading Christine E 
Published: June 2018

SummaryHuman blood platelets were suspended in plasma or Krebs solution and incubated with radiolabeled glycylglycine or glycylproline in order to study cellular uptake. Platelets accumulated radioactivity against a concentration gradient. In the case of glycylglycine, uptake was not inhibited by cold, or metabolic inhibitors. Uptake of radioactivity derived from glycylglycine or glycylproline did not appear to involve saturable mechanisms since the platelet content of radioactivity was directly related to medium concentration even at high concentrations.Chromatographic identification of radioactivity in cells and incubation media showed the glycylglycine was not extensively hydrolysed; 80 per cent of platelet radioactivity was intact dipeptide. With glycylproline, cellular radioactivity was entirely 14C-glycine. There was no direct evidence that this dipeptide actually entered the cells, and we could not determine whether entry did occur with subsequent hydrolysis, or whether hydrolysis preceded uptake.
Platelet Metabolism in Alcohol-related Thrombocytopenia
Authors: Cowan Dale H 
Published: June 2018

SummaryThe carbohydrate metabolism of platelets from patients with alcohol-related thrombocytopenia was studied. Rates of utilization and oxidation of 14C-glueose, 14C-lactate production, and pentose cycle activity were measured in resting platelets and in platelets stimulated with thrombin or epinephrine. The metabolism of resting platelets from patients with alcohol-related thrombocytopenia was normal but the metabolic responses to stimulation differed from normal : stimulation with thrombin was associated with subnormal 14C-lactate production and normal 14CO2 production and that with epinephrine was associated with normal 14C-lactate production and subnormal 14CO2 production. Addition of ethanol to normal platelets in vitro produced increases in 14C-glucose utilization and 14C-lactate production but not in 14C-glucose oxidation. Ethanol added to normal platelets in vitro did not affect the metabolic response to thrombin stimulation but produced a 50% reduction in the response to epinephrine. Platelet dysfunction in patients with alcohol-related thrombocytopenia is not due to quantitative abnormalities in platelet energy production. Ethanol appears, however, to alter the metabolic response to nucleotide release and degradation.
Abnormalities in Clotting and Thrombolysis as a Risk Factor for Stroke
Authors: Pilgeram L. O 
Published: June 2018

SummaryFour hundred and six patients with ischemic thrombotic cerebrovascular disease (ITCVD) and 115 age-matched controls were studied to select risk factors which would identify ITCVD-prone individuals from a healthy population. The following factors were evaluated : soluble fibrin, plasminogen, plasminogen activator, fibrinogen, partial thromboplastin time, generation of thromboplastin, fibrin degradation products, triglycerides, type IV lipoproteinemia, and cholesterol. Discriminate function analyses were used to select those risk factors which best separate and classify the ITCVD and control subjects. The primary risk factors are the activated partial thromboplastin time, soluble fibrin, fibrinogen, and plasminogen activator. Utilizing only these four primary risk factors in a discriminate function, 93.2% of the patients were correctly classified. Consideration of other variables increased still further the dis-criminate function.
Critical Evaluation of Impedance Phlebography for the Diagnosis of Deep Vein Thrombosis
Authors: Wu Kenneth K , Hoak John C , Barnes Robert W , Frankel Stuart L 
Published: June 2018

SummaryIn order to evaluate its daily variability and reliability, impedance phlebography was performed daily or on alternate days on 61 patients with deep vein thrombosis, of whom 47 also had 125I-fibrinogen uptake tests and 22 had radiographic venography. The results showed that impedance phlebography was highly variable and poorly reliable. False positive results were noted in 8 limbs (18%) and false negative results in 3 limbs (7%). Despite its being simple, rapid and noninvasive, its clinical usefulness is doubtful when performed according to the original method.