bluuebunny/crossref_metadata_2025 huggingface dataset:
Gaia Data Release 2
Authors: Mowlavi N. , Lecoeur-Taïbi I. , Lebzelter T. , Rimoldini L. , Lorenz D. , Audard M. , De Ridder J. , Eyer L. , Guy L. P. , Holl B. , Jevardat de Fombelle G. , Marchal O. , Nienartowicz K. , Regibo S. , Roelens M. , Sarro L. M.
Published: July 2018

Context. Gaia Data Release 2 (DR2) provides a unique all-sky catalogue of 550 737 variable stars, of which 151 761 are long-period variable (LPV) candidates with G variability amplitudes larger than 0.2 mag (5–95% quantile range). About one-fifth of the LPV candidates are Mira candidates, the majority of the rest are semi-regular variable candidates. For each source, G, GBP, and GRP photometric time-series are published, together with some LPV-specific attributes for the subset of 89 617 candidates with periods in G longer than 60 days.

Aims. We describe this first Gaia catalogue of LPV candidates, give an overview of its content, and present various validation checks.

Methods. Various samples of LPVs were used to validate the catalogue: a sample of well-studied very bright LPVs with light curves from the American Association of Variable Star Observers that are partly contemporaneous with Gaia light curves, a sample of Gaia LPV candidates with good parallaxes, the All-Sky Automated Survey for Supernovae catalogue of LPVs, and the Optical Gravitational Lensing Experiment (OGLE) catalogues of LPVs towards the Magellanic Clouds and the Galactic bulge.

Results. The analyses of these samples show a good agreement between Gaia DR2 and literature periods. The same is globally true for bolometric corrections of M-type stars. The main contaminant of our DR2 catalogue comes from young stellar objects (YSOs) in the solar vicinity (within ~1 kpc), although their number in the whole catalogue is only at the percent level. A cautionary note is provided about parallax-dependent LPV attributes published in the catalogue.

Conclusions. This first Gaia catalogue of LPVs approximately doubles the number of known LPVs with amplitudes larger than 0.2 mag, despite the conservative candidate selection criteria that prioritise low contamination over high completeness, and despite the limited DR2 time coverage compared to the long periods characteristic of LPVs. It also contains a small set of YSO candidates, which offers the serendipitous opportunity to study these objects at an early stage of the Gaia data releases.
Effectiveness of application alternative drive vehicles in public transport
Authors: Dyr Tadeusz , Ziółkowska Karolina , Misiurski Przemysław , Kozłowska Małgorzata
Published: July 2018

European transport policy for the first half the 21st century assumes creating the transport system organised with the respect of the principle of sustainable development, providing economic, social and ecological needs of the society and supporting construction of the integrated society and entirely integrated and competitive Europe. Applying alternative fuels and drives in public transport vehicles, including the development of electric-powered vehicles is an essential instrument of this policy. In the paper fuels applied in the public transport and alternative drives were described. Methodological establishments of evaluation of the investment's financial and economical effectiveness associated with acquiring public means of transport with the alternative drive were discussed. Using the method of the econometric modelling, operational and maintenance costs of use buses with the conventional and alternative drive were described. They constitute the basis of assessment of the financial effectiveness of replacing conventional vehicles with alternative propulsion vehicles. They pointed to benefits resulting from limiting the influence of public transport using alternative propulsion vehicles on the natural environment. They find expression in decreasing transport's external expenses, confirming the economic effectiveness of their application. A special attention was paid on vehicles with the electric propulsion. Their application in the urban transport is a crucial factor of improvement of the air quality in cities. Based on conducted examinations it was pointed at the purpose of applying means of transport with the alternative drive.
Rapid services – the Czech high-speed rail project for Central Europe
Authors: Ilík Jan , Pomykala Agata
Published: July 2018

In March 2017, the Czech parliament passed a resolution obliging the government to launch a high-speed line program. Government resolution on launching the program was adopted in May 2017. The High Speed Railway Development Program in Czech Republic is intended to target international connections in several axes: Dresden-Prague-Brno-Vienna/Bratislava/Budapest, Katowice-Ostrava-Brno- Vienna/Bratislava/Budapest, Wroclaw-Prague-Munich. This network is supposed to improve Prague's accessibility to other cities in Czech Republic but also to major agglomerations of neighbouring states. This project is not only railway project but also a project of national development. One-day trip will include, among others, Dresden, Berlin, Vienna, Bratislava, Budapest and Warsaw together with other big cities in Poland. Since 2010 in Polish - Czech cooperation are being prepared studies on lines Wrocław - Praga and Katowice - Ostrava. The high-speed railway program implementation in Czech Republic and in Poland and Baltic Countries will result in an effective connection between Prague and Baltic Countries capitals. Creation of an international fast railway network in Central Europe is a part of the EU's transport policy framework for TEN-T network development and will contribute to the progress of economic links in the region. In addition, it is going to be involved in the European Union social and economic cohesion improvement.
Traction power consumption as a component of maximum speed choice on High Speed Lines
Authors: Żurkowski Andrzej
Published: July 2018

The paper includes briefly the most important methodological considerations for selecting the maximum speed for the newly designed HSL. They provide a context for discussion on energy aspects regarding traction energy costs. The research problem in question includes both the assessment of the absolute values associated with the consumption of traction energy and their reference to other costs and revenues associated with the operation of the High Speed Rail (HSR). The proposed approach is based on an analysis of the experience described in the international literature of the subject and simulation calculations for Polish conditions. Based on the approximate results and dependences in this field obtained by the railways with operational experience in relation to the typical HSR train sets, the records of dependencies which are most likely to be confirmed in Polish conditions are presented. Currently, 3 kV DC is used on the railway network in Poland. This is therefore technically different from the one designed on HSL (25 kV AC), which the calculations are related to. Choosing the maximum speed for HSL must take into account the consumption of electricity because of its significant cost. However, the shortening of travel time by increasing the speed makes the HSR offer more attractive and thus allows for increased revenues. The final decision should therefore be a compromise based on detailed calculations, forecasts and simulations.
Case study of stationary energy storage device in a 3 kV DC traction system
Authors: Jefimowski Włodzimierz , Nikitenko Anatolii
Published: July 2018

The paper presents the results of economic study of energy storage system (ESS) implemented in 3 kV DC power supply system. Two conceptions of ESS have been investigated: ESS with supercapacitor (SC) and hybrid ESS (HESS) with SC and LFP battery. The investigated locations of energy storage systems are considered among existing traction substations in two railway lines with different density of train operation. The considered aims of energy storage system implementation are decreasing of energy consumption by maximum regenerative energy utilization and reduction of peak 15- min power demand of traction substation. The paper presents a method of regenerative power estimation depending on the location of the considered ESS implementation point. Also the method of optimal location selection of ESS in terms of minimization of Simple Payback Time (SPBT) of investment is presented. Besides the influence of initial cost value as well as energy price on the SPBT value are investigated. The results are compared between two railway lines with different number of trains operating.
Effectiveness of urban transport modes
Authors: Pomykala Agata
Published: July 2018

Social expectations in terms of improving the conditions of life in cities whilst increase of mobility poses a difficult challenge for urban transport organizers. At the same time, conditions related to sustainable development policies with scarce resources and available reserves focus attention on transport optimization and reduction of environment harmful impacts. The paper presents an assessment of the efficiency of urban transport in terms of capacity, energy use, CO2 emissions and costs, based on data on European medium cities in traffic conditions - peak (congestion) and off-peak traffic (no congestion). Compared were road vehicles: cars and buses of different propulsion, motorcycles and also rail vehicles: metro, tram/light rail and trains/heavy rail. The results are presented in tables or in graphs. The comparisons make it possible to identify the most efficient, in various scenarios, transport modes and may be helpful in deciding on issues related to the provision and organization of urban transport. In this article, cost evaluation omits external costs (although CO2 emissions are taken into account) but includes fixed and variable costs associated with the use of vehicles (including fuel costs, maintenance, inspections, depreciation, insurance).In the preparation of the article information available in literature, publication and reports, particularly of the European Commission one was used.
Analysis of wayside energy storage devices for DC heavy rail transport
Authors: Radu Petru Valentin , Drazek Zbigniew
Published: July 2018

The proposed paper presents the possibility of using the wayside energy storage devices (WESD) for the DC Heavy Rail Transport treating the design, costs and payback time. Moreover a case study comparison for the use of wayside energy storage devices on the heavy transport at the supply voltage of 3.3kV DC is presented. A method of sizing the energy storage devices using vehicle characteristics, traction power supply and running timetable is presented. The paper also presents the cost analysis for the most commonly used energy storage devices and the payback time.
Children traffic fatalities in Croatia from 2005 until 2016
Authors: Missoni E. , Mlinarić T. J. , Božić B.
Published: July 2018

The goal of this paper is to investigate and demonstrate the problem of fatalities of Croatian children under the age of 13 near suburban railways. Specific attention will be payed to the manner and conditions in which they are being instructed and accustomed to use this particular means of transport. Concluding remarks indicate that children should be taught from an early age that although using the suburban railways is very effective and has numerous advantages, in can nevertheless pose a safety risk if they do not behave cautiously (especially when getting on and off the train). In this research the authors examine the traffic injury death rates among children in the Republic of Croatia aged 13 and less over a twelve-year period. From 2005 until 2016 a total of 203 children were fatally injured. The most fatalities occurred in 2006 when a total of 26 children were killed, whereupon in 2016 that figure decreased to 2. Although the number of fatally injured children is gradually decreasing, it still gives cause for concern. In addition, over a ten-year period, from 2006 until 2015, a total of 515 children were seriously injured. Most of these injuries occurred in 2006 (98 children injured), while in 2015 there were only 30 injured children. The overall rate of fatal traffic accidents in Croatia of 8.3 (2012) per 100,000 inhabitants is even now at a high level compared to other European countries.
Evaluation of tramway overhead line system in city of Osijek
Authors: Haladin Ivo , Lakušić Stjepan , Duvnjak Ivan
Published: July 2018

Overhead line system is a vital element of any electrified railway infrastructure. Its performance reflects to all vital parameters such as traction, reliability, availability and safety of railway infrastructure. Operator GPP Osijek runs a 27.5 km long tramway network which plays a key role in transit system of the city of Osijek, Croatia. In 2016 GPP Osijek applied to a tender for acquisition of new rolling stock with 85% EU investment. Mayor requirement prior to rolling stock acquisition was to document, analyse and upgrade current infrastructure (including track structure, electric substations and catenary) to an optimal level. Task of measurement and evaluation of tram track structure and catenary has been appointed to University of Zagreb Faculty of Civil Engineering. Overhead line analysis comprised from several measuring procedures, including supporting columns evaluation, catenary stagger, height, shocks and wear. Such extensive analysis included GPS positioning and on-site evaluation of 1214 supporting columns of overhead line, as well as overhead line measurements using an instrumented tram vehicle on 18 km of track. For conducting overhead catenary wire measurements, a tram pantograph has been fitted with equipment for measuring catenary height, accelerometers for shock measurement, camera, ruler and GPS for stagger measurement. Catenary wire wear was checked manually from catenary inspection vehicle. To conduct measurements, power had to be switched off on all electric substation along the route and tram vehicle had to be towed by a catenary inspection vehicle. All the data has been analysed and presented to end user in a user-friendly and intuitive GIS environment capable of further updates and detailed analyses. Evaluation of overhead line based on direct measurement results pointed out all the defects and weak spots on the system. It resulted in a series of recommendations for reconstruction and upgrade of the catenary system to fit the need of existing state and further development of tramway network.
Metallurgical principles of microstructure formation in sub-zero treated cold-work tool steels – a review
Authors: Jurči Peter , Ptačinová Jana , Sahul Martin , Dománková Mária , Dlouhy Ivo
Published: July 2018

The beneficial influence of a sub-zero treatment on wear resistant tools and components has been known for over 100 years. On the other hand, the basic metallurgical principles being responsible for enhanced hardness and wear performance, changes in the tempering response and toughness and improved dimensional stability have become known only over the past decade. The sub-zero treatment has, thus, been changed from an art to accepted science. The topic of the current conference paper is the latest theory explaining the metallurgical background for this kind of treatment. This theory states that it is the low-temperature isothermal martensitic transformation that induces secondary microstructural effects, such as an accelerated precipitation rate for transient carbides, formation of very small globular carbides and overall refinement of the microstructure. Consequently, secondary microstructural effects have a clear impact on the most relevant properties. The extent of the improvement or deterioration of these properties may be a result of competitive microstructural effects.
Sensor system for controlled carbonitriding
Authors: Klümper-Westkamp Heinrich , Skalecki Marian G. , Zoch Hans-Werner
Published: July 2018

Carbonitriding is mainly used to enhance the hardenability and wear resistance of unalloyed steels. Last year investigations have shown that improved component properties can efficiently be obtained by carbonitriding also low alloy and even higher alloy steels. The importance of carbonitriding rises. In the past, carbonitriding was done with constant ammonia additions, e.g. 2–5 vol% are added to the carburizing atmosphere without controlling or measuring the nitriding potential of the atmosphere. The results scatter in a wide rage depending on furnace, batch size and load and many other influencing factors. The need for a control system is obvious. The presented sensor system allows carbonitriding processes, where carbon and nitrogen potentials of the atmosphere are controlled. This allows adjusting surface carbon and nitrogen contents to desired values independently and guarantees constant product quality. The sensor system consists of a combination of an ammonia and an oxygen sensor and simulation software. By this way online diffusion profile calculation for carbon and nitrogen are possible even for alloyed steels taking alloy factors for both into account. These alloy factors, measured for many steel grades and phase boundaries, were calculated with Thermocalc.
A review on the modeling and simulations of solid-state diffusional phase transformations in metals and alloys
Authors: Liu Xueyan , Li Hongwei , Zhan Mei
Published: July 2018

Solid-state diffusional phase transformations are vital approaches for controlling of the material microstructure and thus tailoring the properties of metals and alloys. To exploit this mean to a full extent, much effort is paid on the reliable and efficient modeling and simulation of the phase transformations. This work gives an overview of the developments in theoretical research of solid-state diffusional phase transformations and the current status of various numerical simulation techniques such as empirical and analytical models, phase field, cellular automaton methods, Monte Carlo models and molecular dynamics methods. In terms of underlying assumptions, physical relevance, implementation and computational efficiency for the simulation of phase transformations, the advantages and disadvantages of each numerical technique are discussed. Finally, trends or future directions of the quantitative simulation of solid-state diffusional phase transformation are provided.
Rasheedia n. nom. (Nematoda, Physalopteridae) for Bulbocephalus Rasheed, 1966 (a homonym of Bulbocephalus Watson, 1916), with description of Rasheedia heptacanthi n. sp. and R. novaecaledoniensis n. sp. from perciform fishes off New Caledonia
Authors: Moravec František , Justine Jean-Lou
Published: July 2018

The nematode genus Bulbocephalus Rasheed, 1966 (Nematoda, Physalopteridae) was found to be a homonym of Bulbocephalus Watson, 1916 (Apicomplexa) and, therefore, a new name, Rasheedia n. nom., is proposed to substitute it. Based on light and scanning electron microscope studies of specimens collected from the digestive tract of perciform fishes off New Caledonia, two new species of Rasheedia are described: R. heptacanthi n. sp. from the Cinnabar goatfish Parupeneus heptacanthus (Mullidae) (type host) and Dentex fourmanoiri (Sparidae), and R. novaecaledoniensis n. sp. from the Indian goatfish Parupeneus indicus (Mullidae). These new species are mainly characterized by the number of anterior protrusible oesophageal lobes (two in R. heptacanthi and four in R. novaecaledoniensis), structure of the oesophagus and the lengths of spicules. An amended diagnosis of Rasheedia and a key to species of this genus are provided. Three previously described congeneric species are transferred to Rasheedia as R. deblocki (Le-Van-Hoa, Pham-Ngoc-Khue & Nguyen-Thi-Lien, 1972) n. comb., R. inglisi (Rasheed, 1966) n. comb. and R. pseudupenei (Vassiliadès & Diaw, 1978) n. comb. Cestocephalus Rasheed, 1966 [genus inquirendum], including C. serratus Rasheed, 1966 and C. petterae (Le-Van-Hoa, Pham-Ngoc-Khue & Nguyen-Thi-Lien, 1972) n. comb., should be considered to be separate from Rasheedia. The names Pseudomazzia Bilqees, Ghazi & Haseeb, 2005 and P. macrolabiata Bilqees, Ghazi & Haseeb, 2005, established for a nematode somewhat resembling Rasheedia spp., should be considered nomina dubia. Rasheedia heptacanthi n. sp. and R. novaecaledoniensis n. sp. are the first representatives of the Physalopteridae recorded from fishes in New Caledonian waters.
Sicuophora (Syn. Wichtermania) multigranularis from Quasipaa spinosa (Anura): morphological and molecular study, with emphasis on validity of Sicuophora (Armophorea, Clevelandellida)
Authors: Li Can , Zhao Weishan , Zhang Dong , Wang Runqiu , Wang Guitang , Zou Hong , Li Wenxiang , Wu Shangong , Li Ming
Published: July 2018

Morphological studies of Sicuophora (Syn. Wichtermania) multigranularis Xiao et al., 2002, from the rectum of the frog, Quasipaa spinosa, performed using silver impregnation and scanning electron microscopy, confirmed the following newly recognized features: (1) only one apical suture on the right surface; (2) two naked regions at the posterior end of both the left and the right side of the body. Phylogenetic analysis based on the SSU-rRNA gene showed that S. multigranularis is a sister to a clade comprising all other Clevelandellida, strongly supporting the validity of the genus Sicuophora. This is also the first molecular data obtained for the genus Sicuophora. Because of the lack of molecular data, it will be necessary to obtain more genetic data from the family Sicuophoridae to discuss the question of the taxonomic status of the genus Sicuophora.
Massive Blutung aus infiziertem Punktionskanal
Authors: Krönung Gerhard
Published: July 2018

Einzeitige autologe In-situ-Infektsanierungen sind in der Gefäßchirurgie nicht Standard. Der Erfahrene kann mit Einsatz dieser Methode aufwendigere Revisionen (z. B. extraanatomischer Bypass) oder komplikationsträchtige Alternativen (E-PTFE-Shunts, zentralvenöse Katheter) vermeiden.
Spondylitis – Spondylodiscitis – an Update
Authors: Bornemann Rahel , Rössler Philip , Jacobs Cornelius , Randau Thomas , Rommelspacher Yorck , Wirtz Dieter , Pflugmacher Robert
Published: July 2018

Die Spondylodiszitis ist eine Infektion der Bandscheiben mit einer nachfolgenden Infektion der benachbarten Wirbelkörper. Hauptursache sind 3 Erregergruppen: Bakterien (pyogene Infektion), Tuberkuloseerreger und Pilze (granulomatöse Infektion) und Parasiten. Bei der pyogenen Spondylodiszitis dominieren meist Monoinfektionen mit Staphylococcus aureus bei einer Häufigkeit bis zu 80%. Die Letalität liegt bei der Spondylodiszitis bei 2 – 3%. Tuberkulöse Infektionen sind häufig mit Psoas- und paravertebralen Abszessen assoziiert. In bis zu 50% der Patienten werden neurologische Ausfälle registriert. Zur mikrobiologischen Diagnostik werden Blutkulturen für aerobe und anaerobe Keime eingesetzt. Die histologische Untersuchung führt jedoch signifikant häufiger zu einem positiven Erregernachweis. Hinsichtlich Genauigkeit ergibt sich eine deutliche Überlegenheit der 16S-rRNA-PCR im Vergleich zur mikrobiologischen Untersuchung von Gewebeproben. Das MRT zeigt eine hohe Sensitivität und Spezifität und ist daher den anderen radiologischen Methoden überlegen. Die Beseitigung der Infektion, die Verminderung der schmerzhaften Beschwerden sowie die Wiederherstellung und Bewahrung von Struktur bzw. Funktion der Wirbelsäule gelten als Hauptziele jeder Behandlungsmaßnahme. Eine standardisierte Antibiotikatherapie der Spondylodiszitis ist bisher nicht eindeutig definiert. Entscheidend sind der Erregernachweis und eine entsprechende gezielte Antibiotikatherapie. Die antibiotische Therapie sollte zunächst 2 – 4 Wochen intravenös verabreicht werden. Anschließend ist eine Umstellung auf eine orale Gabe für 6 – 12 Wochen vorzusehen. Beim Nachweis antibiotikaresistenter Infektionen mit neurologischen Ausfällen wird empfohlen, ein chirurgisches Vorgehen mit sorgfältigem Débridement und Instrumentation vorzunehmen sowie eine Nachbehandlung mit intravenös verabreichten Antibiotika über 3 Wochen mit anschließend 3-monatiger oraler Antibiotikabehandlung zu verordnen. Chirurgische Eingriffe sind indiziert bei neurologischen Defiziten, progressiver Zunahme spinaler Deformierungen, Versagen der konservativen Therapie mit unzureichender Schmerzlinderung und unsicherer Keimidentifizierung. Die Auswahl des Operationsverfahrens sollte hauptsächlich nach dem Ausmaß der Knochendestruktion, der Lokalisation und den individuellen Gegebenheiten bei den Patienten richten. Eine gute Prognose kann gestellt werden, wenn CRP und BSG in den ersten Wochen deutlich abfallen.
Telemedizin in der Nephrologie
Authors: Jahn Michael , Kopecky Jens , Meister Sven , Kribben Andreas , Koisar Karoline , Becker Stefan
Published: July 2018

Innovative Ansätze in der Telemedizin haben das Potenzial, die Versorgung von Patienten in der Nephrologie effizienter und effektiver zu gestalten. Zum Einsatz
kommende Systeme sollten unabhängig von technischen Spezifizierungen Daten untereinander austauschen können und im Einklang mit Datenschutzvorgaben und der
ärztlichen Schweigepflicht sein.
Vermindertes Wachstum bei nierenkranken Kindern
Authors: Hartmann Lisa Maria
Published: July 2018

Eine chronische Niereninsuffizienz bedeutet für betroffene Kinder eine nicht unerhebliche Veränderung in ihrem jungen Leben – Dialysesitzungen, eine Umstellung ihrer Ernährung, die Einnahme von Medikamenten und schließlich auch einverzögertes Längenwachstum. Verschiedene, durch die Niereninsuffizienz bedingte Pathomechanismen verhindern, dass das vom Körper ausreichend produzierte Wachstumshormon an entsprechenden Stellen in richtiger Dosierung adäquat wirken kann. An dieser Stelle kann betroffenen Kindern eine Therapie mit dem Wachstumshormon helfen, das täglich über eine subkutane Injektion verabreicht wird. Diese Therapieoption bedeutet jedoch nicht nur Positives für die kleinen Patienten und deren Familien, sodass eine Therapieentscheidung mit allen Möglichkeiten, Risiken und Begleittherapien (Ernährungstherapie, medikamentöse Therapie des Säure-Basen-Haushaltes u. a.) zusammen mit den Familien getroffen werden muss.
An Unusual Case of Acute Thrombosis of Abdominal Aortic Aneurysm without Acute Limb Ischemia
Authors: Vasdekis Spyridon , Mastoraki Sotiria , Lazaris Andreas , Moulakakis Konstantinos
Published: July 2018

Acute thrombosis of an abdominal aortic aneurysm (AAA) is a rare and often devastating complication with high morbidity and mortality. In some cases, however, it may be associated with a silent course without signs of acute limb ischemia. The aim of this report is to describe an unusual case of acute thrombosis of AAA without signs of acute limb ischemia. Preoperative anxiety, stress, and phobia for surgery may be factors predisposing to acute thrombosis of an AAA.
Genes Associated with Thoracic Aortic Aneurysm and Dissection: 2018 Update and Clinical Implications
Authors: Brownstein Adam , Kostiuk Valentyna , Ziganshin Bulat , Zafar Mohammad , Kuivaniemi Helena , Body Simon , Bale Allen , Elefteriades John
Published: July 2018

Thoracic aortic aneurysms, with an estimated prevalence in the general population of 1%, are potentially lethal, via rupture or dissection. Over the prior two decades, there has been an exponential increase in our understanding of the genetics of thoracic aortic aneurysm and/or dissection (TAAD). To date, 30 genes have been shown to be associated with the development of TAAD and ∼30% of individuals with nonsyndromic familial TAAD have a pathogenic mutation in one of these genes. This review represents the authors' yearly update summarizing the genes associated with TAAD, including implications for the surgical treatment of TAAD. Molecular genetics will continue to revolutionize the approach to patients afflicted with this devastating disease, permitting the application of genetically personalized aortic care.
Hemi-Cabrol Aortic Root Replacement in Complex Aortic Reconstructions
Authors: Dimarakis Ioannis , Kadir Isaac
Published: July 2018

The Cabrol aortic root replacement with subsequent modifications remains an extremely useful technique within the armamentarium of the aortic surgeon. The technical considerations detailed here allow for the uncompromised creation of a hemi-Cabrol anastomosis in complex aortic reconstructions.
Plasma and Platelet Lipid Composition and Platelet Aggregation by Arachidonic Acid in Women on the Pill
Authors: Sadurska B , Tacconi M T , di Minno G , Roncaglioni M C , Pangrazzi J , Donati M B , Bizzi A , Silver M J
Published: July 2018

Sensitivity to induction of platelet aggregation by arachidonic acid (AA) and changes in plasma and platelet polyunsaturated fatty acid distribution were studied in seven women before and after six months of oral contraceptive (OC) treatment with a combination of d-norgestrel (0.25 mg) and ethinylestradiol (0.05 mg). Special interest was focused on AA because certain metabolites of this fatty acid induce platelets to aggregate and are considered to play a crucial role in thromboembolic processes.

In plasma, AA concentrations increased slightly, but significantly, in both the free fatty acid (FFA) and phospholipid fractions; in platelets AA increased in the phospholipid and neutral lipid fractions. The threshold aggregating concentration (TAC) of AA was significantly reduced in platelets of women after six months of OC treatment (0.65 ± 0.08 versus 0.30 ±0.04 mM). This suggests that changes in platelet fatty acid composition may be associated with in vitro changes in platelet sensitivity to AA. Such changes may contribute to the thrombotic tendency associated with OC treatment.
A Survey of 215 Non-Hemophilic Patients with Inhibitors to Factor VIII
Authors: Green David , Lechner Klaus
Published: July 2018

Information was obtained by questionnaire about 215 nonhemophilic patients who developed inhibitors against factor VIII (antihemophilic factor). The majority of the patients were over 50 years of age, and approximately equal numbers of males and females were reported. Rheumatoid arthritis was present in 8% of the cases, 7% occurred during pregnancy or the post-partum period, and in several there was an association with allergy to penicillin, asthma, “auto-immune” diseases, or malignancy. In 46% of cases, no underlying disorders were identified. Major bleeding was observed in 87 % of patients, and in 22%, death was attributed either directly or indirectly to the presence of the inhibitor.

In 11 of 31 patients receiving no therapy other than supportive transfusions of blood or factor VIII concentrate, the inhibitor disappeared after being present for an average duration of 14 months. Corticosteriods were thought to be effective in abolishing the inhibitor in 22 of 45 patients in whom these were the only drugs administered. Twenty-eight patients received azathioprine as well as corticosteriods; in 19, the inhibitor declined or disappeared during treatment. Finally, 80 patients were treated with cyclophosphamide; in 37 there was a favorable outcome. Inhibitors in children and post-partum patients were more likely to disappear spontaneously or with steroid therapy, whereas those in patients with rheumatoid arthritis or other “autoimmune” disorders required treatment with alkylating agents. However, before any specific therapy can be recommended for this disorder, prospective trials of potential therapeutic agents should be conducted in selected subgroups.
A Novel Missense Mutation in Two Families with Congenital Plasminogen Deficiency: Identification of an Ala675 to Thr675 Substitution
Authors: Mima N , Azuma H , Shigekiyo T , Saito S
Published: July 2018

We used a polymerase chain reaction (PCR) strategy and restriction fragment polymorphism analysis to evaluate all 19 exons of the plasminogen (PLG) gene in a Japanese patient with congenital PLG deficiency and her family members (family C). Sequence analysis following amplification of each exon and its flanking regions showed a single G to A transition in exon 17, resulting in the conversion of an Ala675 codon (GCT) to Thr675 codon (ACT). Since this mutation generates a new Mae III site, the Mae III digestion patterns of the PCR-amplified exon 17 fragments from each family member were analyzed. In all cases, the patterns correlated with the activities and antigen levels of plasma PLG in those members. The identical G to A transition in the same codon of exon 17 was detected by a Mae III digestion experiment in another proband and her family members with congenital PLG deficiency (family K). Furthermore, 20 normal individuals examined had no Mae III restriction site at this location. We conclude that a G to A transition in exon 17 is responsible for the congenital PLG deficiency inherited in these two Japanese families.
Probability of Recurrence of Thrombosis in Patients with and without Factor V Leiden
Authors: Rintelen C , Pabinger I , Knöbl P , Lechner K , Mannhatter Ch
Published: July 2018

Activated protein C (APC) resistance is a common risk factor for venous thromboembolism and is associated with the replacement of Arg 506 by Gin in the factor V gene (factor V Leiden). We investigated the risk of recurrence of venous thromboembolism in APC resistant patients heterozygous and homozygous for FV Leiden and compared these patient groups with a group of patients, who had a history of venous thromboembolism, but had neither APC resistance nor the FV Leiden mutation. APC resistance was determined in frozen blood samples from patients with a history of venous thromboembolism, who were not receiving oral anticoagulant (OAC) treatment. The plasma samples were collected between 1984 and 1991. Twenty-one patients in whom APC resistance was found in the stored plasma samples were reinvestigated in 1994 (5 males, 16 females, median [m] age 49 years, range 21-71 years). Twenty-one sex and age matched patients with venous thromboembolism (5 males, 16 females, age m = 50 years, range 25-73 years) investigated during the same time period who had a normal APC resistance test served as a control group. Patients with APC resistance as well as controls were reinvestigated for the presence of FV Leiden by genetic analysis in 1994. Of the 21 APC resistant patients, 5 were homozygous and 16 heterozygous for FV Leiden. Before the study entry homozygous patients had a significantly higher recurrence rate (5/5 patients) compared to the control group, in heterozygous patients (9/16) and controls (9/21) the recurrence rate was not significantly different.

The total observation time was 21 years in patients with homozygous FV Leiden, 83 years in patients with heterozygous FV Leiden and 108 years in controls, excluding the time when patients were on OAC treatment. During the observation time the recurrence rate was highest in patients with homozygous FV Leiden (9.5 % per patient per year), but was similar in patients with heterozygous FV Leiden (4.8% per patient per year) and controls (5% per patient per year). Two of five (40%) homozygous patients, 4/16 (25%) heterozygous and 5/21 (24%) controls had at least one recurrent event during the observation period. The probability for development of thrombosis in the Kaplan-Meyer-Plot analysis was not different between the three groups.

Bearing limitations of our study in mind (retrospective design, relatively small patient number) we conclude that the risk of recurrence after a thromboembolic event is not higher in patients with heterozygous FV Leiden than in patients without this mutation. Thus, it appears that the identification of heterozygous FV Leiden mutation is not an indication for long-term OAC treatment. Also, long-term OAC treatment cannot generally be recommended for homozygous patients with a single thromboembolic event. More definitive conclusions will require larger prospective studies.
Aprotinin in Aortocoronary Bypass Surgery: Increased Risk of Vein-Graft Occlusion and Myocardial Infarction? Supportive Evidence from a Retrospective Study
Authors: van der Meer J , Hillege H L , Ascoop C A P L , Dunselman P H J M , Mulder B J M , van Ormmen G V A , Pfisterer M , van Gilst W H , Lie K I ,   For the CABADAS Research Group of the Interuniversity Cardiology institute of the Netherlands
Published: July 2018

To assess the thrombotic risk of aprotinin in aortocoronary bypass surgery, we retrospectively analyzed the results of a trial, originally designed to compare the effects of one-year treatment with various antithrombotic drugs in the prevention of vein-graft occlusion. Graft patency at one year was assessed by angiography. Myocardial infarction, thromboembolism, major bleeding, and death were clinical endpoints. Of 948 randomized patients, 42 received aprotinin, all enrolled by one of the participating centres. Occlusion rates of distal anastomoses were 20.5% in the aprotinin group and 12.7% in the non-aprotinin group (p = 0.091). The proportions of patients with occluded grafts were 44.1% versus 26.3% (p = 0.029). Perioperative myocardial infarction occurred in 14.3% and 7.0%, respectively (p = 0.12). Mean postoperative blood loss was 451 ml in the aprotinin group compared with 1039 ml in the non-aprotinin group (p <0.0001). Mean transfusion requirements were 1.1 U versus 2.1 U of red blood cells (p = 0.004).

Aprotinin decreases blood loss and transfusion requirement. Our data suggest that this benefit may be associated with a reduction of graft patency and an increased risk of myocardial infarction.
Purine Metabolism In Megakaryocytes And Platelets
Authors: Levine R F , Webster H K
Published: July 2018

Levels of purine nucleotides (PU NTD),incorporation of labelled adenosine (Ar) and hypoxanthine (Hyp), and the distribution of these labels in the purine pathways were studied in intact human, monkey, and guinea pig (gp) platelets (pits) and in megakaryocytes (megas) from monkeys and gp. Following incubations of 5-180 min., perchloric acid extracts were made of 109 pits or of 0.6-1.0×l06 megas per experiment. PU NTD in pits were separated by gradient anionic exchange HPLC; PU nucleosides and bases were separated by reversed-phase HPLC. Simultaneous quantitation was accomplished by on-line UV and radioactivity detectors. Concentrations of PU NTD in pits were comparable in all 3 species and to those in the literature for human pits. No major differences were found in the profiles of PU NTD of megas from monkeys and gp. The concentrations of adenylates in 106 megas were the same as in 109 pits. Differences were observed in purine interconversion pathways between pits and megas for Hyp, the only purine base available in a measurable quantity for salvage. Megas synthesized both adenylates and guanylates via IMP from HYP.

No significant incorporation of Hyp was found in pits studied under the same conditions. In contrast, Ar was incorporated in both pits and megas, and then deaminated or directly converted to AMP. These studies found that megas have retained the capacity to synthesize PU NTD by salvage of Hyp. They are thus closer to other kinds of rapidly proliferating cells than to end stage cells such as pits, in which this pathway did not appear to be significant.
Identification Of Human Megakaryocytes Grown In Vitro By Two Monoclonal Platelet Antibodies
Authors: Vainchenker W , Bouguet J , Guichard J , Michael A Mc , Breton-Gorius J
Published: July 2018

The absence of specific cytochemical markers of the megakaryocyte (MK) lineage at light microscopy level has rendered difficult studies of human megakaryocyte colonies, particularly in pathology. In order to solve this problem, we have used two mouse hybridoma platelet antibodies on culture of human CFU-M. One of them, AN51 recognizes platelet glycoprotein I. CFU- M from human adults, newborns and fetuses have been grown in plasma clot in the presence of a stimulating factor (PHA-LCM-). Indirect immunofluorescence was performed from day 10 to day 14 of culture on unfixed preparations. The results have shown that AN51 stains cultured MK. However, this staining was heterogenous among the megakaryocytes. By comparison with a simultaneous study by electron microscopy (EM), it could be demonstrated that this heterogeneity was mainly related to the degree of maturity of the MK. This result suggests that synthesis of glycoprotein I occurs during MK maturation. In contrast, the second antibody stains more immature MK. Study of fetal and neonatal cultures has confirmed our previous res ults that a large number of these MK are small mature MK (micromegakaryocytes). In myeloproliferative disease, particularly in chronic myeloid leukemic, the number of MK colonies was extremely high with the presence of a large proportion of micromegakaryocytes which otherwise could only be identified by electron microscopy. Studies of human MK culture with monoclonal antibodies provide a new powerful tool to understand normal and pathological megakaryopoiesis.
Morphological Study Of 5-Ht Organelles In Human Megakaryocytes
Authors: Hourdille P , Fialon P , Belloc F , Bernard P , Boisseau M R
Published: July 2018

Human blood platelets possess dense bodies which have been clearly demonstrated to be the storage site for 5-hydroxytryptamine and the non-metabolic pool of ADP. Previous electron microscopy investigations performed on human megakaryocytes have revealed electron-opaque granules, but only in platelet-forming megakaryocytes. In this study different methods of visualizing platelets 5-HT storage organelles were applied to human megakaryocytes. The observations were facilited by the high enrichment of megakaryocytes obtained using the Percoll density centrifugation. By conventional electron microscopy we rarely observed dense bodies similar in size and opacity to those observed in platelets. Using uranaffin cytochemical method we observed typical and atypical uranaffin-positive organelles. Distribution of these organelles was heterogeneous with numerous megakaryocytes containing only few granules. Using mepacrine labelling test, human megakaryocytes could bedetected easily since they are large and have multilobulated nucleus. Their nucleus was intensely fluorescent and was surrounded by a slightly-fluorescent cytoplasm. For each sample, 50 megakaryocytes were examined 96 ± 1.4 % of the megakaryocytes exhibited greenish yellow, very fluorescent granules with a flashing phenomenon. These granules were randomly distributed in the whole cytoplasm. The other 4 ± 1.4 % detected by their morphological characteristics no granules were observed. We found no correlation between megakaryocytes size and the presence of granules.

These results indicate that mepacrine labelling test and uranaffin cytochemical electron microscopy are very useful tests for megakaryocytes 5-HT organelles study, and allow us to correlate the results obtained by these different methods.
Identification Of The Procoagulant Species In Ellagic Acid Solutions
Authors: Bock Paul E , Shore Joseph D
Published: July 2018

The species of ellagic acid responsible for initiating intrinsic blood coagulation has been characterized. Ellagic acid is soluble ata level of 30 ± 10 μM in pH 7.4 Tris-saline buffer at 22°C. Dilution of soluble ellagic acid resulted in enhanced plasma procoagulant and kallikrein generating activity, and the appearance of a new absorbance spectrum. These effects were prevented by 1 mi4 EDTA, and the new species could be removed by centrifugation. Addition of stoichiometric Cu2+ to Millipore-filtered soluble ellagic acid generated an absorbance spectrum similar to that caused by dilution in the absence of EDTA, as well as procoagulant and kallikrein activities. Zn2+ and Co2+ caused similar spectral changes and prekail ikrein activation. Although no turbidity was visible and the spectral properties did not indicate extensive light scattering, centrifugation resulted in loss of the absorbance spectrum and activity. We conclude that the procoagulant activity of ellagic acid solutions can be ascribed to slowly settling insoluble aggregates of ellagic acid-metal ion complexes, which are formed with adventitious metal ions present in the diluting buffer. Formation of these aggregates could be prevented but not reversed by 1 mM EDTA. Although soluble ellagic acid may bind to Factor XII, it does not initiate blood coagulation or prekallikrein activation, since these activities were only associated with the insoluble species.
Role Of Hmw Kininogen In Polysaccharide Sulfate-Mediated Activation Of Factor XII
Authors: Kato H , Shimada T , Sugo T , Iwanaga S
Published: July 2018

We have shown that bovine HMW kininogen (HMW KGN) accelerates the activation of Factor XII (XII) and prekallikrein (Prek) in the presence of kaolin, adsorbing on kaolin through fragment 1.2 region and forming a complex with Prek through light chain region. The present study was undertaken to examine the functional role of HMW KGN in the activation of XII and Prek with other negatively-charged surfaces than kaolin. XII was incubated with a variety of substances, HMW KGN and Prek, and plasma kallikrein generated was estimated using a fluorogenic peptide substrate, Z- Phe-Arg-MCA.

Among 8 kinds of polysaccharide sulfates (dextran sulfate, xylan sulfate, amylopectin sulfate, chondroitin polysulfate, heparan sulfate, amylose sulfate, heparin and carrageenin), amylose sulfate had the most potent ability to activate XII. The experiments using fourteen amylose sulfates with different sulfur content and different viscosity revealed that some amylose sulfates with a higher sulfur content (18%) activated strikingly XII and Prek in the presence of HMW KGN. In the reaction, fragment 1.2-light chain region in HMW KGN was shown to be essential, using the various derivatives of HMW KGN. The rate of XII activation was quite dependent on the concentration of HMW KGN and amylose sulfate. At higher concentrations, both of them inhibited the activation reaction. On the other hand, sulfatide has been shown to accelerate the activation of XII with plasma kallikrein by Fujikawa et al. and the reaction was inhibited by the addition of HMW KGN. In the present study, the activation of XII and Prek with sulfatides as estimated by the generation of kallikrein, was accelerated by HMW KGN. This reaction was also dependent on the concentrations of sulfatides and HMW KGN, and fragment 1.2-light chain region in HMW KGN was shown to be essential.

These results indicate that HMW KGN is required to accelerate the activation of XII and Prek with polysaccharide sulfate and sulfatide as well as kaolin.
Stimulation Of Human Platelet Coagulant Activity By Endotoxin: A New Leukocyte-Mediated Pathway
Authors: Semeraro N , Locati D , Colucci M
Published: July 2018

Despite the frequent occurrence of thrombocytopenia in patients with Gram-negative sepsis, a direct human platelet- endotoxin interaction in vitro can be hardly demonstrated. We report here that human platelets develop strong coagulant activity after simultaneous incubation with endotoxin and leucocytes in plasma. Whole blood or platelet-rich plasma (PRP) enriched of leukocytes were incubated at 37°C for 4 hours with different endotoxins (E.coli LPS, S. Minnesota LPS and a purified Lipid A, 10 ug/ml final concentration); leukocyte-free washed platelet suspensions isolated from these samples were found to markedly shorten the recalcification time of normal plasma (77 ± 11 sec, as compared to 359 ± 47 sec, obtained with platelets isolated from similar samples incubated with sterile saline, n=15). When platelets were challenged with endotoxin in the absence of white blood cells (i.e. in PRP) the subsequentely isolated and washed platelets had no procoagulant activity suggesting that leukocytes are essential mediators in the development of platelet coagulant activity induced by endotoxin. Experiments in which PRP was enriched with mononuclear cells or granulocytes revealed that the former were responsible for this property. “Stimulated” platelets shortened the recalcification time of plasmas deficient in any of the factors of the intrinsic pathway or of factor VII-deficient plasma to the same extent as in normal plasma. The rate of clotting was much lower in factor X-deficient plasma. These data indicate that, in contrast to leukocytes, whose procoagulant activity has well-known tissue factor-like properties, platelets act on coagulation factor X independently of both the intrinsic and extrinsic clotting pathways. Our findings add a new function to circulating mononuclear cells and may be relevant to understanding the postulated role of platelets in the activation of blood coagulation during endotoxemia in man.