bluuebunny/crossref_metadata_2025 huggingface dataset:
Recommended Protocols for Instrumental Assessment of Voice: American Speech-Language-Hearing Association Expert Panel to Develop a Protocol for Instrumental Assessment of Vocal Function
Authors: Patel Rita R. , Awan Shaheen N. , Barkmeier-Kraemer Julie , Courey Mark , Deliyski Dimitar , Eadie Tanya , Paul Diane , Švec Jan G. , Hillman Robert
Published: June 2018

Purpose

The aim of this study was to recommend protocols for instrumental assessment of voice production in the areas of laryngeal endoscopic imaging, acoustic analyses, and aerodynamic procedures, which will (a) improve the evidence for voice assessment measures, (b) enable valid comparisons of assessment results within and across clients and facilities, and (c) facilitate the evaluation of treatment efficacy.

Method

Existing evidence was combined with expert consensus in areas with a lack of evidence. In addition, a survey of clinicians and a peer review of an initial version of the protocol via VoiceServe and the American Speech-Language-Hearing Association's Special Interest Group 3 (Voice and Voice Disorders) Community were used to create the recommendations for the final protocols.

Results

The protocols include recommendations regarding technical specifications for data acquisition, voice and speech tasks, analysis methods, and reporting of results for instrumental evaluation of voice production in the areas of laryngeal endoscopic imaging, acoustics, and aerodynamics.

Conclusion

The recommended protocols for instrumental assessment of voice using laryngeal endoscopic imaging, acoustic, and aerodynamic methods will enable clinicians and researchers to collect a uniform set of valid and reliable measures that can be compared across assessments, clients, and facilities.
Cancers classification based on deep neural networks and emotional learning approach
Authors: Jafarpisheh Noushin , Teshnehlab Mohammad
Published: June 2018

In the present era, enormous factors contribute to causing cancer. So cancer classification cannot rely only on doctor's thoughts. As a result, intelligent algorithms concerning doctor's help are inevitable. Therefore, the authors are motivated to suggest a novel algorithm to classify three cancer datasets; colon, ALL‐AML, and leukaemia cancers. Their proposed algorithm is based on the deep neural network and emotional learning process. First of all, by applying the principal component analysis, they had a feature reduction. Then, they used deep neural as a feature extraction. Then, they implemented different classifiers; multi‐layer perceptron, support vector machine (SVM), decision tree, and Gaussian mixture model. In the end, because in the real world, especially when working on systems biology, unpredictable events, and uncertainties are undeniable, the robustness of their model against uncertainties is important. So they added Gaussian noise to the input features of the first encoder in each dataset, then, they applied the stacked denoising method. Experimental results disclosed that, generally, using emotional learning increased the accuracy. In addition, the highest accuracy was gained by SVM, 91.66, 92.27, and 96.56% for colon, ALL‐AML, and leukaemia, respectively. However, GMM led to the lowest accuracy. The best accuracy gained by GMM was 60%.
Modeling and use of stellar oscillation visibilities
Authors: Schou J.
Published: June 2018

Context. Recently our ability to study stars using asteroseismic techniques has increased dramatically, largely through the use of space based photometric observations. Work has also been performed using ground based spectroscopic observations and more is expected in the near future from the SONG network. Unfortunately, the intensity observations have an inferior signal-to-noise ratio and details of the observations do not agree with theory, while the data analysis used in the spectroscopic method has often been based on overly simple models of the spectra.

Aims. The aim is to improve the reliability of measurements of the parameters of stellar oscillations using spectroscopic observations and to enable the optimal use of the observations.

Methods. While previous investigations have used 1D models, I argue that realistic magnetohydrodynamic simulations, combined with radiative transfer calculations, should be used to model the effects of the oscillations on the spectra. I then demonstrate how to calculate the visibility of the oscillation modes for a variety of stellar parameters and fitting methods. In addition to the methods used in previous investigations, I introduce a singular value decomposition based technique. This new technique enables the determination of the information content available from spectral perturbations and allows this content to be expressed most compactly. Finally I describe how the time series obtained may be analyzed.

Results. It is shown that it is important to model the visibilities carefully and that the results deviate substantially from previous models, especially in the presence of rotation. Detailed spectral modeling may be exploited to measure the properties of a larger number of modes than possible via the commonly used cross-correlation method. With moderate rotation, there is as much information in the line shape changes as in the Doppler shift and an outline of how to extract this is given.
An analysis of the TZ Fornacis binary system
Authors: Higl J. , Siess L. , Weiss A. , Ritter H.
Published: June 2018

Context. TZ Fornacis (TZ For) is an evolved detached binary system that is difficult to model and interpret, but very useful for testing stellar evolution theory and physics.

Aims. We aim to search for solutions that are self-consistent and to determine the necessary stellar physics input. We also check solutions found previously for their internal consistency and for reproducibility.

Methods. We use both a single and a binary stellar evolution code, and take into account all known system properties. We determine the physical stellar parameters by imposing that the models match the known radii for identical stellar ages. The evolution has to be consistent with a binary system in classical Roche geometry.

Results. We obtained two different solutions to model TZ For successfully. Both depend on avoiding a long evolution on the first giant branch and imply a sufficiently large convective core on the main sequence. TZ For can be modelled consistently as a detached binary system by invoking either a substantial amount of core overshooting or a tidally enhanced wind mass loss along the red giant branch. An evolution with Roche-lobe overflow can definitely be excluded.

Conclusions. A comparison of our results with previous studies also reveals that in addition to uncertainties associated with the input physics, the modelling of overshooting by different algorithms can have a strong impact.
Cold electrons at comet 67P/Churyumov-Gerasimenko
Authors: Engelhardt I. A. D. , Eriksson A. I. , Vigren E. , Valliéres X. , Rubin M. , Gilet N. , Henri P.
Published: June 2018

Context. The electron temperature of the plasma is one important aspect of the environment. Electrons created by photoionization or impact ionization of atmospheric gas have energies ~10 eV. In an active comet coma, the gas density is high enough for rapid cooling of the electron gas to the neutral gas temperature (a few hundred kelvin). How cooling evolves in less active comets has not been studied before.

Aims. We aim to investigate how electron cooling varied as comet 67P/Churyumov-Gerasimenko changed its activity by three orders of magnitude during the Rosetta mission.

Methods. We used in situ data from the Rosetta plasma and neutral gas sensors. By combining Langmuir probe bias voltage sweeps and mutual impedance probe measurements, we determined at which time cold electrons formed at least 25% of the total electron density. We compared the results to what is expected from simple models of electron cooling, using the observed neutral gas density as input.

Results. We demonstrate that the slope of the Langmuir probe sweep can be used as a proxy for the presence of cold electrons. We show statistics of cold electron observations over the two-year mission period. We find cold electrons at lower activity than expected by a simple model based on free radial expansion and continuous loss of electron energy. Cold electrons are seen mainly when the gas density indicates that an exobase may have formed.

Conclusions. Collisional cooling of electrons following a radial outward path is not sufficient to explain the observations. We suggest that the ambipolar electric field keeps electrons in the inner coma for a much longer time, giving them time to dissipate energy by collisions with the neutrals. We conclude that better models are required to describe the plasma environment of comets. They need to include at least two populations of electrons and the ambipolar field.
The Response of Megakaryocytes with Processes to Thrombin
Authors: Radley J M , Hartshorn M A , Green S L
Published: June 2018

The response of megakaryocytes to thrombin (1-10 U/ml) has been examined by time-lapse cinemicrography and electron microscopy. The study was confined to mature megakaryocytes which had developed processes following incubation in vitro. The initial response of all cells was to undergo retraction of processes, behaviour thought to be linked with the depolymerization of microtubules which extend longitudinally through the processes. The majority of cells completely withdrew their processes, but about 30% responded differently and underwent only limited retraction, followed by secretion. Analysis of time-lapse film showed that processes from the latter group of cells had formed attachments with the coverslip prior to exposure to thrombin. Within the partially retracted processes of these cells, secretory granules were found to be clustered centripetally and enveloped by a rnicrofilamentous structure in the form of a cylinder. Vacuoles appeared, some of which were located outside the rnicrofilamentous structure. Microtubules were present, but many appeared disorientated. The shape of the rnicrofilamentous structure suggests that the cytoplasm is not organized into putative platelets at the time of process formation.
Relationship Between Fibrinopeptide A and Fibrinogen/Fibrin Fragment E in Thromboembolism, DIC and Various Non-Thromboembolic Diseases
Authors: Mombelli G , Monotti R , Haeberli A , Straub P W
Published: June 2018

Increased fibrinopeptide A (FPA) levels have been reported in various non-thrombotic disorders, including cancer, acute myocardial infarction, liver cirrhosis and collagen vascular diseases. To investigate the significance of these findings, the present study combined the radioimmunoassay of FPA with that of fibrinogen/fibrin degradation fragment E (FgE) in the aforementioned disorders and compared the results with those observed in healthy subjects as well as in patients with thromboembolism and overt disseminated intravascular coagulation (DIC). Mean FPA and FgE in malignancy were 6.3 and 305 ng/ml, in myocardial infarction 5.6 and 98 ng/ml, in liver cirrhosis 2.7 and 132 ng/ml and in collagen vascular diseases 5.6 and 142 ng/ml. All these values were significantly higher than in healthy controls (mean FPA 1.6 ng/ml, mean FgE 49 ng/ml) but significantly lower than in thromboembolism (mean FPA 10.7 ng/ml, mean FgE 639 ng/ ml) and DIC (mean FPA 22.0 ng/ml, mean FgE 1041 ng/ml). The overall correlation between FPA and FgE was highly significant. Elowever, different disorders showed peculiar patterns in FPA, FgE and fibrinogen levels. In malignancy, a definite increase of FPA, FgE and plasma fibrinogen levels was observed. This finding probably indicates a compensated state of (intra- or extravascular) fibrin formation and lysis. Acute myocardial infarction was characterized by a high FPA to FgE ratio, which is interpreted to reflect acute thrombin generation and fibrin formation. FPA in cirrhosis was only marginally elevated with most single values within the normal range, indicating that intravascular coagulation was infrequent and unimportant in quantitative terms.
Platelet Adhesion to Native Collagens Involves Proteoglycans and May Be a Two-Step Process
Authors: Behnke O
Published: June 2018

Adhesion of rat blood platelets to native rat tail collagen fibrils was studied in the electron microscope under conditions that preserved collagen-associated proteoglycans (CAPG). The CAPG molecules were aligned in chain-like configurations that encircled the fibrils with a 65 nm period; they appeared to coat the fibrils completely and extended 60-100 nm away from the fibril. The initial platelet-fibril contact occurred between the platelet glycocalyx and the CAPG of the fibrils i.e. between two surfaces with net-negative charges. When close contact was established between the fibril surface proper and the platelet membrane, CAPG were not identified in the area of contact, and the collagen-platelet distance was reduced to a ~10-12 nm wide gap traversed by delicate links in register with fibril periodicities.
A Clinical and Laboratory Study of a Patient with an Unusual Factor VIII Inhibitor
Authors: Bloom A.L , Davies A.J , Rees J.K
Published: June 2018

The clinical and laboratory features of a patient with a post-partum factor VIII inhibitor are described. A large sublingual haematoma caused respiratory distress but this was quickly relieved by treatment with bovine antihaemo- philic globulin. The inhibitor activity rapidly declined possibly because of corticosteroid therapy but factor VIII levels subsequently remained reduced.

Inactivation of factor VIII by the inhibitor in vitro increased on incubation but was incomplete and did not give the linear pattern described by Biggs and Bidwell (1). Although the clotting time of the patient’s blood was prolonged a factor VIII level of 18% was detected. The inhibitor was apparently more active when residual factor VIII was assayed by a one-stage than by a two- stage method and it inactivated similar proportions of factor VIII when this was added to plasma in different concentrations. Factor VIII could not be recovered from combination with the inhibitor by euglobulin precipitation. The results suggest that the inhibitor altered the reactivity of factor VIII.

A transiently positive direct antiglobulin test suggested an immunological basis for the syndrome but although the inhibitor showed some species specificity for human factor VIII no other supporting evidence was obtained.
Coagulopathies et Carcinomes Riches en Mucopolysaccharides
Authors: Bagnoud F
Published: June 2018

Trois cas d’adénocarcinome mucipare sont rapportés. Ils ont en commun une importante dissémination hématogène de la tumeur et des thromboses. Chez deux d’entre eux, révolution se complique d’une diathèse hémorragique. L’autopsie révèle une précipitation massive de fibrine dans le système artériolocapillaire viscéral. Cette dyscrasie est classée dans le groupe des coagulopathies par consommation. Le rôle pathogénique des mucines tumorales dans la genèse des thromboses est discuté.
The Separation of AHF from Fibrinogen. IV
Authors: van Creveld S , Mochtar I. A , Pascha C. N
Published: June 2018

The anti-hemophilic factor (AHF, factor VIII) has been separated from fibrinogen by means of continous flow electrophoresis. The starting material was Cohn’s fraction I, prepared from normal human resinplasma. These fibrinogen-free products still contained proteins without AHF-activity. Part of these contaminating proteins could be extracted from fraction I by means of a 1 molar solution of epsilon amino caproic acid. The residue, principally consisting of fibrinogen and AHF, was dissolved in a triethylamine buffer and subjected to continuous flow electrophoresis. The resulting AHF-preparations were free from fibrinogen. By immuno-electrophoresis no proteins without AHF-activity could be demonstrated in these preparations.
Effect of Dextran infusion on the Adenosine Diphosphate Induced Adhesiveness and the Spreading Capacity of Human Blood Platelets
Authors: Bygdeman S , Eliasson R , Gullbring B
Published: June 2018

The adenosine diphosphate induced platelet adhesiveness to glass and the platelet spreading capacity on a siliconized glass surface have been studied in 8 hypovolemic subjects after infusion of 500 ml 6% solution of dextran 70 (Macrodex®) or 500 ml normal saline. Infusion of dextran caused a significant decrease in platelet adhesiveness compared with the controls while no effect was noted on the spreading capacity.

It is proposed that the observed effect on platelet adhesiveness is due to dextran induced changes in the activity of plasma factors involved in the mechanisms leading to platelet adhesiveness.
Adenine Nucleotides in Platelets from Normal and Uraemic Subjects
Authors: Pitney W. R , Hinterberger H , Potter M
Published: June 2018

Adenine nucleotides in platelets from normal and uraemic subjects were measured before and after passage of blood through glass bead filters. Platelets from uraemic subjects contained normal amounts of ATP, ADP, AMP and total nucleotides. Normal platelets which had passed through filters contained higher concentrations of ATP, ADP and total nucleotides than platelets in control blood samples, indicating either heterogeneity of adenine nucleotide content in normal platelets or possibly adsorption of nucleotides onto platelets during their passage through the filters. This phenomenon was not observed with platelets from uraemic patients.
Release of Nitrocatecholsulfatase during Blood Coagulation from Thrombocytes
Authors: Polášek J , Rotrekl B
Published: June 2018

In this study the release of NCS from blood platelets into the serum during blood coagulation and its dependence on time and temperature have been studied. In a group of 10 males and 10 females, the NCS activity in the plasma was determined and compared with that in the serum.
Studies on Thrombolysis with Streptokinase
Authors: Gottlob R , Blümel G
Published: June 2018

In vitro whole blood clots were incubated in SK, washed several times in Ringer-solution and then introduced into plasminogen solution. These clots showed marked signs of lysis surpassing those observed in clots that had only been incubated in SK. There was a correlation between the duration of the SK incubation and the clot lysis in the plasminogen solution. We deduce from these findings that SK enters the clots by diffusion and that this process lasts several hours.

If SK-incubated clots are placed into an SK-free environment, the SK slowly diffuses out of the thrombi.

Even in contact with very slight plasminogen concentrations, SK-incubated clots undergo distinct degrees of lysis.
Sustained Lymphatic Delivery of Fibrinogen after Induced Afibrinogenemia
Authors: Young Margaret C. , Kolmen S. N
Published: June 2018

Lymphatic fibrinogen levels were maintained for a long period in the absence of plasma fibrinogen. Although a portion of the additional fibrinogen required may have been the result of de novo synthesis, an additional source, that of previously sequestered fibrinogen in storage sites, must have been present.

The amount of fibrinogenolysis induced, although complete in the plasma compartment of dogs, was not as effective in the lymphatic compartment. One resultant of fibrinogenolytic induction in vivo was retardation of fibrin polymerization in incubated lymph samples.
Clotting Factors and Fibrinogen Split Products in the Extravascular Space
Authors: Benz J. J
Published: June 2018

Factors I, II, V, VII-complex, X, fibrinogen-split products and fibrinolysis were assayed in 42 transsudates, 69 exsudates and simultaneously in the blood of the respective patients.

The vitamin K dependent factors II, VII-complex and X were present in all extravascular specimens; factors V and clottable fibrinogen only in the majority of exsudates and the minority of transsudates. Fibrinogen-split products were found in most specimens even though the simultaneously tested serum of the respective patients was free of them. The collected quantitative data indicate that all clotting factors enter the extravascular space in direct proportion to their concentration in plasma and to the protein content of the extravascular fluid. Local extravascular lysis accounts for the low values of clottable fibrinogen and factor V and for the presence of fibrinogen split products. It is possible that the physiologic catabolism of these factors is mainly extravascular.
The Modification of Experimental Occlusive Arterial Thrombosis in the Rat by Malayan Pit Viper Venom
Authors: Chan K. E
Published: June 2018

The effect of Malayan pit viper (Ancistrodon rhodostoma) venom on the fate of experimental arterial thrombosis was studied in rats. A suitable daily dose of venom (500 μg) was used to induce hypofibrinogenaemia in the treated rats for the greater part of each of three consecutive post-operative days.

The treated animals showed a statistically significant overall reduction in the incidence of both red thrombus formation and thrombotic arterial occlusion when compared to a control group. This antithrombotic effect of the venom could be observed in the 7-day period following the cessation of the treatment.
Prothrombin Purification by Chromatography
Authors: Landaburu R. H , Albado Emilia , Santillán R
Published: June 2018

Bovine prothrombin with specific activity above 40,000 u/mg of tyrosine may be obtained by chromatography on Amberlite AG3-X4. The product does not yield autoprothrombin C in appreciable amounts. A fraction separated by this procedure behaves as a procoagulant when replaced into the purified prothrombin.
Metabolic Studies of Vitamin K1-14C and Menadione-14C in the Normal and Hepatectomized Rats
Authors: Losito R , Owen C. A , Flock E. V ,   Rochester, Minnesota
Published: June 2018

The metabolism of vitamin K1-
14C and menadione-14C (vitamin K3-14C) was studied in normal and hepateetomized rats. After the administration of menadione, about 70% of the 14C was excreted in the urine in 24 hrs in both types of rats. Two urinary metabolites were identified by enzymatic hydrolysis: one a glucuronide and the other a sulfate of reduced menadione. Thus, the liver is not necessary for the metabolism of menadione. In the vitamin K1 studies, the intact rats excreted only 10% of the 14C and the hepatectomized rats excreted less than 0.5%. The retention of vitamin K1 may explain its superiority over menadione as an antidote for overdosages of oral anticoagulants.
Properties of 3-(1-Phenyl-Propyl)-4-Oxycoumarin (Marcoumar®) in the Plasma when Tested in Normal Cases and under the Influence of Drugs
Authors: Seiler K , Duckert F
Published: June 2018

A fluorimetric method served to determine Marcoumar in blood plasma. The biological half-time of Marcoumar after an administration of 2.2 mg/10 kg is 6½ days. Variations in maintenance dose requirements seem not to be primarly determined by differences in absorption or excretion of the anticoagulant drug. In therapeutical concentrations about 99% of the drug are bound to plasma protein. Marcoumar can be displaced in vitro from plasma protein by different drugs. The anticoagulant effect is not increased in every case in which the anticoagulant is displaced in plasma from its protein binding.
Studies on Thrombolysis with Streptokinase
Authors: Gottlob R , Blümel G , Piza F , Brücke P , Böhmig H. J
Published: June 2018

1. Human thrombi of various ages obtained by surgery were incubated in SK solution. Whereas thrombi up to 2 days old showed no considerable lysis, older thrombi, in some cases more than 1 month old, showed good lysibility in SK.

2. The good lysibility of older thrombi was reproduced in in vitro whole blood clots.

3. Similar to the findings obtained in experimental thrombi, we found that in in vitro whole blood clots retraction goes along with a marked decrease in the water content, whereas we find again a moderate rise with increasing age.

4. If we add 131I-labelled human serum albumin to the supernatant of in-vitro clots, we see an increased absorption of albumin, particularly in the second and third day after clotting.

5. Massive hemolysis sets in on the second and third day in whole blood clots incubated at 37 centigrades in their own serum.

6. The following are discussed as possible causes for the improved lysibility of older thrombi and clots : renewed absorption of plasminogen from the milieu ; the release of ferments that may be activated by SK in the process of cytolysis, and a decrease in the content of plasmin inhibitors.

7. Based on the findings the suggestion is advanced to attempt lytic therapy with SK even in the case of older clinical thrombi.
Release of Platelet Factor 4 in Vivo during Intravascular Coagulation and in Thrombotic States
Authors: Farbiszewski R , Niewiarowski S , Worowski K , Lipiński B
Published: June 2018

Platelet factor 4 released from platelets into the circulating blood was determined using both the heparin thrombin time and paracoagulation methods. It has been found that thrombin injected intravenously into rabbits releases large amounts of this factor. Infusion of plasmin does not release this factor and this finding may be of importance for the differential diagnosis between disseminated intravascular clotting and primary fibrinolysis. PF4 is not released during the hyper coagulable condition induced by HgCl2 intoxication. Only small amounts of this factor are released after contact factor infusion.

A significant elevation of extraplatelet PF4 was found in 23 patients with fresh coronary thrombosis and in 9 patients with thrombophlebitis and thromboembolic complications.

The significance of the above findings for the pathogenesis, treatment and laboratory diagnosis of thrombotic diseases with particular reference to heparin tolerance test is discussed.
Différents états moléculaires du facteur II (prothrombine). Leur étude à l’aide de la staphylocoagulase et d’anticorps anti-facteur II
Authors: Soulier J. P , Hallé Liliane , Prou-Wartelle Odette
Published: June 2018

Nous avons examiné dans quelles conditions des préparations de facteur II humain, plus ou moins purifiées, se dissocient en présence de 25 p. cent de citrate de soude ou de sulfate d’ammonium 2 M. L’addition de thrombine intervient en neutralisant l’anti-thrombine contaminant certaines fractions et en apportant du facteur X.

Nous avons mis en évidence au cours de l’incubation une dissociation entre l’activité prothrombine (capacité de former de la biothrombine avec les activateurs physiologiques) qui décroît et l’activité prothrombine-coagulase (capacité de former de la thrombine-coagulase en présence de staphylocoagulase) qui s’accroît. Il est ainsi possible dans l’espèce humaine de suivre la dissociation du facteur II humain et d’apprécier à l’aide de staphylocoagulase la formation d’un produit intermédiaire décrit par Seegers et désigné récemment par cet auteur du nom de préthrombine. La mesure de l’activité prothrombine-coagulase n’est pas modifiée par l’addition d’hiru-dine qui neutralise la thrombine éventuellement formée au cours de l’ auto-activation.

Si la staphylocoagulase est inactive à l’égard du facteur II bovin, elle forme par contre avec le facteur II humain un complexe doué d’une activité thrombique (thrombine-coagulase). Ce complexe se forme plus vite lorsque le facteur II est dissocié au préalable en citrate de soude ou sulfate d’ammonium, c’est-à-dire que la « préthrom-bine » peut être estimée, directement par la staphylocoagulase. L’activité prothrombine-coagulase se développe en quelques secondes et ne nécessite ni calcium ionisé ni aucun co-facteur alors que la préthrombine n’est transformée que beaucoup plus lentement par l’ auto-prothrombine C de Seegers (homologue du facteur X activé).
Influence of Vitamin K on Restoration of Prothrombin Complex Proteins and Fibrinogen in Plasma of Depleted Dogs
Authors: Dulock M. A , Kolmen S. N
Published: June 2018

The action of vitamin K1 on dogs with reduced plasma concentrations of prothrombin and fibrinogen was studied. Thirty-two dogs were divided into two groups; each received either warfarin or nothing 24 hrs prior to blood cross-exchange with an erythrocyte-serum preparation. After exchange, each group was subdivided into dogs receiving either vitamin K1 or saline. Blood and lymph samples were obtained before exchange, after exchange, and at subsequent 2 hr intervals for 6 hrs. Prothrombin times and fibrinogen were among the measurements made.

The data presented support the concept that warfarin blocks synthesis at a late stage where incomplete or precursor prothrombin-complex proteins can be accumulated intracellularly. Vitamin K enables continuation of prothrombin synthesis and enhances the release of prothrombin and fibrinogen into the plasma and lymphatic compartments. Warfarin also affects vascular integrity as suggested by alterations in lymph flow and hematocrit.
Abnormality in the Aggregation of Blood Platelets in Various Morbid Conditions and the Influence of Prostaglandins upon this Abnormality
Authors: van Creveld S , Pascha C. N ,   With technical assistance from Miss L. KERKMEESTER and Mrs. C. J. McEwan-van DER HORST
Published: June 2018

In two young patients (belonging to the same family) with von Willebrand’s disease, an anomaly of the function of the blood platelets was observed, viz. a normal rapid initial aggregation of the platelets after addition of ADP, which after a few minutes was followed by an extraordinarily rapid disaggregation. This anomaly has very recently been described as an isolated anomaly. The same anomalous aggregation could be demonstrated in plasma of the father of the two patients, but he did not have von Willebrand’s disease.

Some other observations of abnormally rapid disaggregation with ADP, after a normal initial aggregation, observed by us in patients with various morbid conditions, are communicated.

The remarkable inhibiting action of one of prostaglandins (PGE1), even in very small amounts upon the ADP induced platelet aggregation could be confirmed. PGE2 also in very small amounts, markedly increased the aggregation by ADP in the cases investigated by us and was able to normalize the anomalous aggregation. It had, however, no effect on the absence of platelet aggregation with ADP in Glanzmann’s thrombasthenia.
Genetic Aspects of Hemostasis
Authors: Quick A. J
Published: June 2018

Hereditary defects resulting in inadequate syntheses of fibrinogen, prothrombin, factors V, VII, VIII, IX and X are quantitatively transmitted, therefore all affected members of a family are identical genetically. The concentration of the clotting factor in the blood is determined by the balance of the rate of synthesis to the rate of consumption or turnover. The required concentrations of these clotting factors to maintain hemostasis are strikingly low but below a critical level, traumatic bleeding occurs. The bleeding time is normal, and capillary or mucous membrane bleeding such as spontaneous epistaxis is uncommon or even absent. These states are transmitted as either autosomal or sex-linked recessives.

Hereditary purpuric bleeding states are usually attributable to abnormal platelet function, to a defect in the autonomic nervous system that maintains the tonus of the microcirculation, or to the telangiectatic state in which the abnormality resides either in the structure of the capillaries or the mesenchymal matrix in which the micro vessels are imbedded. The thrombopathies constitute a group with various types of hereditary transmission. The Minot-von Willebrand syndrome and telangiectasia are transmitted as autosomal dominants. In most affected subjects, the bleeding is mild and superficial, usually from mucous membranes such as nosebleeds. In many the bleeding tendency is almost subclinical. Traumatic bleeding such as intramuscular hemorrhage and hemarthrosis is absent. The bleeding time in the severe cases is prolonged but may be normal in the mild bleeder unless prolonged by the ingestion of a drug such as aspirin.

The clinical severity in the hereditary bleeding diseases is determined by: (1) the functional capacity of the gene responsible for the synthesis of the specific hemostatic factor, (2) the superimposition of a secondary hemostatic defect either hereditary or acquired, and (3) environmental factors which per se do not affect hemostasis. Hemophilia serves as the illustration. No severe bleeding occurs in pure factor VIII deficiency until the concentration is below the range of 1 to 2% of normal. On superimposition, for instance of telangiectasia on a mild hemophilia, the clinical manifestations are markedly accentuated. The simultaneous occurrence of even very mild Minot-von Willebrand syndrome in the hemophiliac will intensify the bleeding tendency, especially after the ingestion of aspirin. Environmental factors illustrated by trauma such as mild contusions, which in the normal do not even cause a bruise, may bring about intramuscular hemorrhages and hemarthroses, and thereby sometimes initiate a bleeding cycle.
Fibrinolytic Activity of Human Veins in Arms and Legs
Authors: Pandolfi M , Robertson B , Isacson S , Marie Nilsson Inga
Published: June 2018

A modification of the fibrin slide method of Todd permitting a semiquantitative estimation of the fibrinolytic activity in tissue sections is described. By means of this technique, the authors have studied the fibrinolytic activity of the great saphenous vein and of superficial veins of the arm and leg in patients suffering from varices and in normal subjects. It was found that:

1. Fibrinolytic activity is localized, in these vessels, mainly to the vasa vasorum of the adventitia. The media is moderately active. Intimal cells are active only when detached.

2. The great saphenous vein is more active above than below the knee.

3. The veins of the arm are definitely more active than the veins of the leg.

4. The activator of plasminogen demonstrated in the sections by the fibrin slide method is a fairly stable enzyme still active after exposure to 60° C and resistent to moderate variations of pH.
Observations on the Effect of Glass Beads on Platelet Aggregation and Its Relation to Platelet Stickiness
Authors: Morris C. D. W
Published: June 2018

1. The concept of glass bead induced reversible and irreversible platelet aggregation is presented.

2. The effect of glass beads in plasma and whole blood was observed microscopically. The microscopic observations were supported by experimental evidence.

3. It is shown that phosphoenol pyruvate (PEP) and pyruvate kinase (PK) are capable of completely preventing aggregation if given before glass bead contact. This indicates that adenosine diphosphate (ADP) is the major factor in stimulating aggregation.

4. It is shown that the ADP is released in this system, from the platelets, and not from the red cells.

5. Haematocrit changes between 20% and 60% do not affect the platelet stickiness.

6. The concentration of ADP apparently determines whether the aggregates become irreversible or not.

7. Siliconised glass beads do not prevent aggregation; on the contrary, they increase both the observed rate of formation of aggregates, and the measured platelet stickiness.

8. Addition of PEP and PK after glass contact causes the reversible aggregates to disaggregate. However, merely leaving the blood to stand for at least 30 min after contact, produces the same effect. This allows the measurement of pure irreversible aggregation.

9. The desirability of measuring the irreversible aggregation is discussed.
In Vitro Assay of Platelet Adhesiveness with Washed and Tanned Human Red Cells
Authors: Zbinden G , Tomlin S
Published: June 2018

An in vitro system is described in which adhesion of blood platelets to washed and tannic acid-treated red cells was assayed quantitatively by microscopic observation. ADP, epinephrine and TAME produced a reversible increase in platelet adhesiveness which was antagonized by AMP. With Evans blue, polyanetholsulfonate, phthalanilide NSC 38280, thrombin and heparin at concentrations above 1-4 u/ml the increase was irreversible. The ADP-induced increase in adhesiveness was inhibited by sodium citrate, EDTA, AMP, ATP and N-ethylmaleimide. EDTA, AMP and the SH-blocker N-ethylmaleimide also reduced spontaneous platelet adhesion to red cells. No significant effects were observed with adenosine, phenprocoumon, 5-HT, phthalanilide NSC 57155, various estrogens, progestogens and fatty acids, acetylsalicylic acid and similarly acting agents, hydroxylamine, glucose and KCN. The method may be useful for the screening of thrombogenic and antithrombotic properties of drugs.
Activation of Blood Clotting and Inhibition of Fibrinolysis in Acute Pancreatitis
Authors: Gabryelewicz A , Niewiarowski S
Published: June 2018

The following changes in patients and dogs with acute pancreatitis or pancreatic necrosis were observed: shortening the plastic and glass clotting time, decrease of factor V, transistory decrease of fibrinogen followed by an increase of this factor, inhibition of euglobulin fibrinolysis, increase of plasminogen and antiplasmin.

Autopsy examinations revealed many thrombi in pancreas and in other organs in dogs as well in humans.

The authors emphasized the similarity between Shwartzman phenomenon and acute pancreatitis and suggest that heparin should be used in the prevention and treatment of acute pancreatitis in human.
Properties of Thrombin and Fibrinogen
Authors: Baughman D. J , Waugh D. F , Juvkam-Wold Constance
Published: June 2018

A standard clotting system has been analysed according to the average clotting time and variations due to thrombin, fibrinogen, day-to-day preparation of reagents and the clotting assay itself. The variations, εT, εF and ετ are reproducible and normally distributed with zero mean.

Transfer of thrombin into a vessel produces adsorption losses at the solution-air (S/A) and solution-wall (S/W) interfaces. Specific loss at τ = 30 sec = (% loss in τ) (thrombin volume)/surface area. For clean non-polar surfaces such as polyethylene or paraffin the average S/W loss of 3.8%-cm (0.77 mg/m2) has the large coefficient of variation of 3.2%. Vessel surfaces may be saturated by prior conditioning using a thrombin concentration tenfold that required to give τ = 50 sec. Emptying and immediately refilling now gives an S/W loss of 0.19%-cm (0.04 mg/m2). The specific S/A loss, always present, is 2.7%-cm (0.54 mg/m2). The combined average loss for conditioned vessels is 1.0% at τ = 30 sec and is reproducible within sτ
2 for single vessels. A set of vessels gives a coefficient of variation of 0.53%.

Stock fibrinogen aliquots are stored frozen at —95° and are thawed and diluted under standard conditions. If a syringe is used to withdraw clotting tube aliquots, SF2 is significantly increased over that obtained by using pipettes. Since pipettes do not contribute, the observed coefficient of variation of 1.7% then applies to the variation between tubes of stock-F. Six different lots of Fraction I gave a coefficient of variation of 12% between lot numbers.

Experiments revealed a variance between equivalent experiments performed on different days (coefficient of variation 1.9%). Within this variance pairs of stock reagents were stable within the maximum limits of ± 0.12% of τ per day. There is no reason to suspect that either stock reagent has an intrinsic instability. The day-to-day variance given above arises from non-reproducibilities in the preparation of buffer diluents. Variances were reduced when buffers were prepared in deaerated water at room temperature.

The total day-to-day coefficient of variation of fibrinogen of 1.5% and the variation between fibrinogen lots effectively eliminates this reagent as a reference standard. Thrombin appeared otherwise : by selecting and reusing reservoirs the maximum total thrombin day-to-day coefficient of variance is 0.36%. Thus, 95% of the thrombin concentrations prepared on different days will lie within 0.72% of the true value. By making use of known purification procedures it is possible to reproduce a stock thrombin reagent. This would serve as a universal standard.
Thrombin - Fibrinogen Clotting Times
Authors: Waugh D. F , Baughman D Joe , Juvkam-Wold Constance
Published: June 2018

The fundamental variation to be taken into consideration in comparing clotting time averages is that of the clotting time assay itself. A variation is ετ whose true variance is στ
2 and the experimental estimate of this variance sτ
2. Described is a clotting time machine automated with respect to temperature, thrombin volume, thrombin injection, stirring and time determination so that the only subjective observation is that of the clotting time endpoint. Statistical analysis of sτ
2 has been made using protocols in which measurements either were carried out in a particular time sequence (regression type protocol) or were randomized (randomization type). An experimental unit is a dilute thrombin solution, a dilute fibrinogen solution and an operator-machine. The dilute reagents come from stock reagents. Characteristics of the system are as follows. 1. For a wide variety of experimental units the ετ are time independent and normally distributed. The sτ
2 from single lots of stock reagents appear to be estimates of the same στ
2. If different stock reagents are used the measured sτ
2 show that στ
2 may change significantly. 2. The variance increases with the clotting time. An approximate square relationship has been used for normalization. 3. The operator-machine and dilute solutions of stock thrombin appear to be remarkably uniform. 4. A change in στ
2 between experimental units is due to fibrinogen and appears particularly when different lots of fibrinogen, Armour’s Fraction I, are used to prepare the purified stock reagent. 5. When time dependent changes occur in experimental units, they are also most likely due to fibrinogen instability. When the storage temperature of stock-F is decreased from —20° to —95°, fibrinogen solubility is stabilized and regression decreased. 6. When instabilities can be made small, a randomization type protocol is preferred since fewer clotting times are required to characterize an experimental unit. When instability is important, a number of assays must be invested in its detection. This number increases approximately linearly with sτ
2 and decreases linearly as the time period for assays increases. The most important limitation to the examination of regressions is the number of clotting times an observer can perform on a single day.
Species-Dependent Inhibition of Platelet Aggregation by Adenosine and Dipyridamole: Paradoxical Potentiation in the Rat
Authors: Philp R. B , Bishop B ,   with the collaboration of
Published: June 2018

Platelets of cats, rabbits, guinea pigs, rats and human subjects were aggregated with adenosine diphosphate after having been in contact with adenosine or dipyridamole for 5 to 60 min. The species profiles of both agents were the same. Both inhibited aggregation of human and rabbit platelets and the degree of inhibition increased with the time of contact. Neither inhibited aggregation of cat or guinea-pig platelets and both potentiated the rate and extent of aggregation of rat platelets: the degree of potentiation increased with the time of contact. Some reports on the related effects of adenosine and dipyridamole are reviewed and it is suggested that the effects of dipyridamole might be due to an affinity for adenosine receptors.
Some Characteristics of the Clottable Protein of Limulus Polyphemus Blood Cells
Authors: Solum N. O
Published: June 2018

1. The endotoxin-clottable protein of Limulus blood cell extracts has been studied. The concept of the clottable protein as a true cell protein was confirmed.

2. 35–55% of total extractable protein was removed from the extracts by clotting. Polyacrylamide disc electrophoresis of the extracts showed 6 to 9 protein bands one of which was reduced in intensity by the clotting. Dimethylf ormamide could be used for fractionated precipitation of the proteins.

3. The gel protein was easily soluble in HCl or NaOH and reprecipitated by neutralization. It was also soluble in 0.05 M formate/6.7 M urea pH 4.3 but not in neutral solutions of urea.

4. Light absorption spectra of the gel protein in 0.188 N NaOH showed maxima at 283 mμ and 290 mμ, whereas one maximum, at 276 mμ, was observed in 0.189 N HCl. E1 %
1 cm in 0.188 N NaOH was 10.4 and 11.1 at 283 mμ and 290 mμ, respectively, and 9.0 at 276 mμ in 0.189 N HCl.

5. Data on the total amino acid composition of the gel protein are given. A mean minimal molecular weight of about 20,000 is calculated from these.

6. In starch gel electrophoresis with a discontinuous acid buffer system the gel protein separated into two main zones. Possible relationships between these are discussed in terms of clotting mechanism.

7. The data show that Limulus clottable protein differs markedly in its molecular characteristics from those of mammalian fibrinogens.
A Method for Automatic Recording of the Osmotic Fragility of Blood Platelets
Authors: Zahavi J , Danon D , Dreyfuss F , Nelken D
Published: June 2018

A method for automatically recording the osmotic fragility of blood platelets, using a Fragiligraph, was developed. Platelet specimens taken from 20 healthy males and 9 females were examined. The mean rate of platelet change and the extent of increase in light transmission (LT) of washed platelets suspended in veronal, Tris, or phosphate buffered saline and dialyzed against water and 0.1% sodium chloride solutions, were analyzed. The recorded curves showed a slow phase lasting 2–74 sec, followed by a phase representing a rapid rate of platelet change in which gradually swelling of the platelets occurred concomitantly with an increase in the LT. This was followed by a third phase of plateau formation. The mean rate of platelet swelling was temperature-dependent, having twice the value at 37° C as at 15° C; the extent (% increase in LT) did not vary with temperature.
Untersuchungen bei zwei Patienten mit kongenitalem Faktor-XIII-Mangel
Authors: Egbring R , Andrassy K , Egli H , Meyer-Lindenberg J
Published: June 2018

Es werden zwei weitere Patienten mit kongenitalem Faktor-XIII-Mangel vorgestellt, bei denen sich ein Plasmagerinnsel in Harnstoffoxalat in Zeiten unter 1 Min. auflöst. Immunologisch war bei beiden Patienten das Faktor-XIII-Protein nachweisbar. Die gerinnungsphysiologische Routineuntersuchung ergab mit Ausnahme einer sich bei langer Laufdauer vermindernden Amplitude im Thrombelastogramm beider Patienten keinen pathologischen Befund. Auch die Plattchenfunktionsprüfungen sowie die Retraktion waren bei beiden Kranken normal.

Eine Methode zur Bestimmung partieller Faktor-XIII-Defekte – wie sie bei sog. Heterozygoten der kongenitalen F aktor-XIII-Mange]-Kranken vorkommt – wurde in Form eines modifizierten Monojodessigsäuretoleranztests entwickelt. Die Verwendung von Harnstoffoxalat als Lösungsmittel hat hierbei den Vorteil, daß zur Beurteilung der Faktor-XIII-Aktivität die totale Lösung des Gerinnsels herangezogen wird. Für die Bestimmung geringer Faktor-XIII-Aktivitäten haben wir zusätzlich das Reaktionsgemisch mit Cystein aktiviert. Dabei kommt es zwar zur Interferenz aller 3 Reaktionsteilnehmer, aber die Lösungszeiten hängen dennoch von dem Faktor-XIII-Gehalt der Gerinnsel ab, wenn die Monojodessigsäure- und Cysteinkonzentration entsprechend eingestellt sind.
Congenital Hemorrhagic Diathesis with Deficiency of Factor XIII
Authors: Abels J , Smit Sibinga C. Th , Meyleb L
Published: June 2018

A male patient with a severe congenital bleeding disorder due to factor XIII deficiency is described. An extensive family study revealed no additional demonstrable deficiencies of this factor. A lowered fibrinogen level in four of the father’s relatives was found, and remained unexplained. Prophylactic treatment with plasma transfusions appeared to be effective.