bluuebunny/crossref_metadata_2025 huggingface dataset:
A Total Synthesis of Norhalichondrin B
Authors: Jackson Katrina L. , Henderson James A. , Motoyoshi Hajime , Phillips Andrew J.
Published: February 2009

Vier gewinnt: Vier Schlüsselbausteine für die Totalsynthese von Norhalichondrin B (siehe Strukturformel) wurden hergestellt und anschließend zum Naturstoff zusammengesetzt. Entscheidende Merkmale der Totalsynthese sind eine Achmatowicz‐Oxidation mit anschließender ionischer Hydrierung zum Aufbau von Pyranen und Pyranopyranen sowie die Anwendung der Tandemmetathese zur Herstellung von Pyranopyranen.

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Raman Spectroscopic Study of the Phase Transition of Amorphous to Crystalline β‐Carbonic Acid
Authors: Kohl Ingrid , Winkel Katrin , Bauer Marion , Liedl Klaus R. , Loerting Thomas , Mayer Erwin
Published: February 2009

What's the matter? The laboratory Raman spectra for carbonic acid (H2CO3), both for the β‐polymorph and its amorphous state, are required to detect carbonic acid on the surface of the pole caps of Mars in 2009, when the Mars Microbeam Raman Spectrometer lands on the planet. The picture shows a martian crater with ice of unknown composition, possibly containing carbonic acid (image adapted from DLR, with permission from ESA, DLR, and FU Berlin –‐G. Neukum).

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Ring‐Opening Polymerization of Cyclic Esters by an Enantiopure Heteroscorpionate Rare Earth Initiator
Authors: Otero Antonio , Fernández‐Baeza Juan , Lara‐Sánchez Agustín , Alonso‐Moreno Carlos , Márquez‐Segovia Isabel , Sánchez‐Barba Luis F. , Rodríguez Ana M.
Published: February 2009

With a sting in its tail: An enantiopure neodymium complex (see scheme) acts as an efficient single‐site initiator for the controlled ring‐opening polymerization of rac‐lactide, forming isotactic polyester. The heteroscorpionate complex was characterized spectroscopically and by X‐ray diffraction.

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A fundamental analysis of continuous flow bioreactor and membrane reactor models with noncompetitive product inhibition
Authors: Nelson Mark Ian , Quigley Joshua Lesley , Chen Xiao Dong
Published: February 2009

We analyze the steady‐state production of a product produced through the growth of microorganisms in both a continuous flow bioreactor and in an idealized continuous flow membrane reactor. The reaction is assumed to be governed by Monod growth kinetics subject to noncompetitive product inhibition. Although this reaction scheme is often mentioned in textbooks, a stability analysis does not appear in the literature.

The steady‐state solutions of the model are found and their stability determined as a function of the residence time. The performance of the reactor at large residence times is obtained. Knowledge of the steady‐state solutions and their asymptotic limits may be useful to estimate parameter values from experimental data. The key dimensionless parameter that controls the degree of noncompetitive product inhibition is identified and we quantify the effect that this has on the reactor performance in the limit when product inhibition is 'small' and 'large'. Copyright © 2009 Curtin University of Technology and John Wiley & Sons, Ltd.
Synthesis and characterization of low‐molecular‐weight polyacrolein
Authors: Marques Maria de Fátima Vieira , Pinto Patricia Reis , de Andrade Cristina Tristão , Michel Ricardo Cunha
Published: February 2009

Acrolein was polymerized in a polar solvent in the presence of terc‐ and sec‐butyl lithium as initiators. Using a low monomer to initiator molar ratio and 1‐h reaction time, cyclic structures were shown to be formed in the main chain of the resulting oligomers. The influence of different monomer to initiator molar ratios on molecular weight and on molecular weight distribution was investigated. Chain‐transfer reactions toward the monomer resulted in lower molecular weights and narrower polydispersions as [M]/[I] increased. The influence of initiator type on the polymer molecular weight was also evaluated. FTIR analysis of the degradation products at different heating temperatures indicated that the oligomers structure is composed of aldehyde, ether, and vinyl functional groups. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Novel thermosets obtained by the ring‐opening metathesis polymerization of a functionalized vegetable oil and dicyclopentadiene
Authors: Henna Phillip , Larock Richard C.
Published: February 2009

New polymeric thermosetting resins prepared by the ring‐opening metathesis polymerization (ROMP) of a commercially available vegetable oil derivative, Dilulin, and dicyclopentadiene (DCPD) have been prepared and characterized. A thorough characterization of the modified oil itself has been carried out to elucidate its structure. Grubbs' second‐generation catalyst has been used to effect the ROMP of the strained unsaturated norbornene‐like rings in the commercial oil. Dynamic mechanical analysis of the resulting thermosetting resins has revealed that glass‐transition temperatures ranging from 36 to −29°C can be obtained when the proper ratio of oil to DCPD is employed. Thermogravimetric analysis has revealed that these resins have very similar temperatures of maximum degradation. Extraction analysis has indicated that all the samples had at least a 20% soluble fraction and that the soluble fraction was composed of oligomers, unreacted triglyceride oil, or both. The effect of the soluble fraction as a plasticizer has also been explored. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Surface properties and antibacterial activity of quaternized polysulfones
Authors: Filimon Anca , Avram Ecaterina , Dunca Simona , Stoica Iuliana , Ioan Silvia
Published: February 2009

Novel quaternized polysulfones (PSFs) with two ionic chlorine contents were investigated, namely, their morphology and antimicrobial activity. Atomic force microscopy (AFM) studies on their membranes showed ordered domains, in which pores and nodules of different sizes and intensities were distributed. The charge density of the quaternized PSFs and the history of the membranes formed from solutions in solvent/nonsolvent mixtures influenced the different aspects of the surface images. The adhesion of Escherichia coli ATCC 10536 and Staphylococcus aureus ATCCC 6538 microorganisms to solutions of the modified PSFs is discussed in correlation with the hydrophobic/hydrophilic properties of the studied polymers and microorganisms. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Effect of the particle size and acid pretreatments on compatibility and properties of recycled HDPE plastic bottles filled with ground tyre powder
Authors: Colom X. , Cañavate J. , Carrillo F. , Suñol J. J.
Published: February 2009

With the growing emphasis on decreasing the accumulation of the used tyres in land fills, there has been significant scientific and technological interest to provide with solutions to their recovery and reuse. A new composite material based on reused tyre powder as reinforcement and recycled high‐density polyethylene as matrix was studied in this work. The effect of chemical acidic pretreatments performed on the rubber and of the particle size on the behavior of the composite material were evaluated. Powder of reused tyres resulting from industrial grinding processes was separated by sieving in three particle size categories: below 200 μm, between 200–500 μm and over 500 μm. Pretreatments using H2SO4, HNO3, or a 50% mix of H2SO4 and HNO3 were carried out over the rubber before composite preparation. Mechanical tensile properties were evaluated to determine the effect of particle size and acid pretreatments on composite properties. Fracture surfaces of composite samples were also evaluated by scanning electron microscopy. Overall, all pretreatments improve the mechanical behavior of the obtained materials. This improvement is attributed to the development of a surface of the rubber, more suitable for mechanical adhesion. The effect of the particle size has a stronger influence in the properties of the material than the acidic pretreatments. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Preparation of amidoximated polyester fiber and competitive adsorption of some heavy metal ions from aqueous solution onto this fiber
Authors: Coşkun Ramazan , Soykan Cengiz
Published: February 2009

In this study, a fibrous adsorbent containing amidoxime groups was prepared by graft copolymerization of acrylonitrile (AN) onto poly(ethylene terephthalate) (PET) fibers using benzoyl peroxide (Bz2O2) as initiator in aqueous solution, and subsequent chemical modification of cyano groups by reaction with hydroxylamine hydrochloride in methanol. The grafted and modified fibers were characterized by FTIR, TGA, SEM, and XRD analysis. The crystallinity increased, but thermal stability decreased with grafting and amidoximation. The removal of Cu(II), Ni(II), Co(II), Pb(II), and Cd(II) ions from aqueous solution onto chelating fibers were studied using batch adsorption method. These properties were investigated under competitive conditions. The effects of the pH, contact time, and initial ion concentration on the removal percentage of ions were studied. The results show that the adsorption rate of metal ions followed the given order Co(II) > Pb(II) > Cd(II) > Ni(II) > Cu(II). The percentage removal of ions increased with initial ion concentration, shaking time, and pH of the medium. Total metal ion removal capacity was 49.75 mg/g fiber on amidoximated fiber. It was observed that amidoximated fibers can be regenerated by acid without losing their activity, and it is more selective for Pb(II) ions in the mixed solution of Pb‐Cu‐Ni–Co‐Cd at pH 4. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
The obedience–disobedience dynamic and the role of responsibility
Authors: Passini Stefano , Morselli Davide
Published: February 2009

Obedience has been thoroughly studied in social psychology, both in its positive and negative aspects. Nevertheless, in these empirical studies disobedience has been considered to be the opposite of obedience and indeed its negation. Instead, some recent studies suggest that if obedience to authority is important in ensuring the continuity of social and group life, disobedience is crucial, under some circumstances, in stopping the authority relationship from degenerating into an authoritarian relationship. In this perspective, disobedience may be conceived of as a protest undermining the legitimacy of authority, or else it can represent an instrument of the community for controlling the legitimacy of the authority's demands, becoming a factor safeguarding against authoritarianism. The aim of the present study was to empirically verify the dynamics existing between disobedience and obedience. The results show that people who attach importance to both obedience and disobedience in the relationship between the individual and society recognize the importance of democratic values and consider themselves responsible for the defence of human rights. Instead, people who only recognize the value of obedience and consider disobedience as a threat to the status quo are more authoritarian, individualistic people. Copyright © 2009 John Wiley & Sons, Ltd.
The importance of brands in the lunch‐box choices of low‐income British school children
Authors: Roper Stuart , La Niece Caroline
Published: February 2009

This research explores the consumer socialisation of children and adolescents from low‐income groups. In particular, the importance of reference groups in cognitive development and understanding is investigated to gain insight into the consumption behaviours immediately before, during and after their 'tweens'. 'Tweens' are defined as 8–12‐year‐olds. To gain a thorough insight into changes in opinion during tweenage years, 7‐, 11‐ and 14‐year‐olds were interviewed in this study. In total 30 children from these three age groups were (depth) interviewed and their discourses were compared to show the development in understanding of brands and peer influence. Whereas previous studies have concentrated on the symbolism behind clothing brands this research looks at the meanings attached to different types of food and beverage brands.

Our interviews suggest peers become more influential to consumption decisions as children move through the tweens and in our study, peer approval replaces family as the main influence behind consumption behaviour. Brand understanding also changes as the child becomes older; children learn how to identify commercial, supermarket and budget brands and attach meaning to these different types of brands. The symbolic meaning of products and brands become more complex during the tween years as children view possessions as material symbols of identity and make inferences about peers based on their consumption choices. This research found that as children become older even simple products change from functional to symbolic items.

Copyright © 2009 John Wiley & Sons, Ltd.
Exploring memory for product names advertised with humour
Authors: Hansen Jochim , Strick Madelijn , van Baaren Rick B. , Hooghuis Mirjam , Wigboldus Daniël H. J.
Published: February 2009

Three studies explored the effects of humour in advertising on brand name memory. Study 1 showed that humour impaired memory for products but enhanced memory for advertisements. Study 2 showed that brands that had been promoted in humorous advertisements were less accessible in memory than brands promoted in non‐humorous advertisements. Study 3 separated conscious and unconscious memory components with the process‐dissociation procedure 1 week after the ad exposure. The memory‐reducing effect of humour was found to be due to conscious memory processes alone. Unconscious familiarity was not affected by humour. The results suggest that humour distracts consumers from consciously, but not unconsciously, remembering the brand names.

Copyright © 2009 John Wiley & Sons, Ltd.
Repeated double cross validation
Authors: Filzmoser Peter , Liebmann Bettina , Varmuza Kurt
Published: February 2009

Repeated double cross validation (rdCV) is a strategy for (a) optimizing the complexity of regression models and (b) for a realistic estimation of prediction errors when the model is applied to new cases (that are within the population of the data used). This strategy is suited for small data sets and is a complementary method to bootstrap methods. rdCV is a formal, partly new combination of known procedures and methods, and has been implemented in a function for the programming environment R, providing several types of plots for model evaluation. The current version of the software is dedicated to regression models obtained by partial least‐squares (PLS). The applied methods for repeated splits of the data into test sets and calibration sets, as well as for estimation of the optimum number of PLS components, are described. The relevance of some parameters (number of segments in CV, number of repetitions) is investigated. rdCV is applied to two data sets from chemistry: (1) determination of glucose concentrations from near infrared (NIR) data in mash samples from bioethanol production; (2) modeling the gas chromatographic retention indices of polycyclic aromatic compounds from molecular descriptors. Models using all original variables and models using a small subset of the variables, selected by a genetic algorithm (GA), are compared by rdCV. Copyright © 2009 John Wiley & Sons, Ltd.
β‐Ca3N2, a Metastable Nitride in the System Ca–N
Authors: Höhn Peter , Hoffmann Stefan , Hunger Jens , Leoni Stefano , Nitsche Fabian , Schnelle Walter , Kniep Rüdiger
Published: February 2009

A new page in the phase book: The metastable nitride β‐Ca3N2, the synthesis, crystal structure (see picture), and physical properties of which are reported, is an isotype of corundum (α‐Al2O3). Vacancies in the crystal structure of β‐Ca3N2 are discussed by using full‐potential local orbital methods and taking into account both the physical properties and the density of states.

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The structural chemistry of calcium nitrides is represented by just two different intermediate phases: cubic Ca3N2 (referred to as α‐Ca3N2, Mn2O3 type structure) and Ca2N (CdCl2 type structure). Other binary phases (“γ‐Ca3N2”, “Ca11N8”) have been proven to represent cyanamide nitrides, Ca4N2[CN2] and Ca11N6[CN2]2, respectively. The metastable nitride β‐Ca3N2 is prepared either by reaction of freshly distilled calcium metal with nitrogen at 700 K, or by reaction of Ca2N with N2 at 500 K. β‐Ca3N2 transforms monotropically (Ttrans≈810 K) to cubic α‐Ca3N2. The crystal structure of β‐Ca3N2 (rhombohedral R$\bar 3$c, no. 167, a=619.884(3) pm, c=1662.958(10) pm) is an isotype of the corundum structure (α‐Al2O3) and comprises a network of NCa6/4 octahedra that share common faces and edges. Magnetic susceptibility and electrical resistivity measurements confirm that β‐Ca3N2 is a diamagnetic semiconductor.
Alkali Metal Cation (K+, Cs+) Induced Dissolution/Reorganization of Porous Metal Carboxylate Coordination Networks in Water
Authors: Wu Jing‐Yun , Ding Miao‐Tzu , Wen Yuh‐Sheng , Liu Yen‐Hsiang , Lu Kuang‐Lieh
Published: February 2009

Reversible structural transformations of porous metal–organic coordination networks based on Co or Ni and the benzene‐1,2,4,5‐tetracarboxylate tetraanion among 3D (4,8)‐connected nets and a 1D zigzag chain structure occur by an unexpected dissolution/reorganization process induced by alkali metal cations (K+, Cs+) in aqueous solution (see scheme).

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Porous metal–organic coordination networks (MOCNs) {A2[M3(btec)2(H2O)4]}n (1, A=K, M=Co; 2, A=K, M=Ni; 3, A=Cs, M=Co; and 4, A=Cs, M=Ni; btec=benzene‐1,2,4,5‐tetracarboxylate) with nearly identical structural features were hydrothermally prepared. These compounds adopt (4,8)‐connected scu nets but exhibit subtle differences in the topology of the final three‐dimensional architectures. Compound 1 has a regular net with the largest solvent void (21.1 %), while the nets of the other three (2–4) are slightly distorted from a regular shape and have malformed pores with smaller solvent voids (5.4–11.4 %). Likely, the different supramolecular environments among 1–4 subtly depend on the eight‐connected binodal cubical vertices/four‐connected square‐planar connectivity between the trimetallic clusters and the btec ligands. Cobalt species 3 dissolved in an aqueous solution of KCl, and then reorganized to form 1 at ambient temperature. Interestingly, under similar conditions, 1 dissolved and then was regenerated to give the same structure. Nickel species 2 and 4 also underwent a dissolution/reorganization process in an aqueous solution of KCl to afford new metal–carboxylate product {K2[Ni3(btec)2(H2O)4]}n (2′). This compound forms a (4,8)‐connected scu net with regular pores, which is isostructural and isomorphous with 1, and is a supramolecular isomer of 2. Similarly, in an aqueous solution of CsCl, 1–4 were converted to 1D zigzag chain structures {Cs2[M(btec)(H2O)4]}n (5, M=Co; 6, M=Ni) that enlarged to hydrogen‐bonded 3D porous supramolecular networks. Remarkable, reversible alkali metal cation induced structural transformations between 1 and 5 occurred via dissolution/reorganization processes. Thermogravimetric analyses showed that these metal–carboxylate species have high thermal stability (T>300 °C).
Highly Enantioselective 1,4‐Addition of Diethyl Phosphite to Enones Using a Dinuclear Zn Catalyst
Authors: Zhao Depeng , Yuan Ye , Chan Albert S. C. , Wang Rui
Published: February 2009

Zinc benefits: The first catalytic asymmetric phospha‐Michael addition of enones has been developed. Under mild reaction conditions, the γ‐oxo phosphonates could be obtained in high yields (up to 99 %) with excellent enantioselectivities (93–99 % ee; see scheme). The strategy makes the asymmetric synthesis of biologically important phosphonate compounds more accessible.

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Recent advances using streptokinase for acute coronary thrombosis
Authors: Udall J. A.
Published: February 2009

Most important in comparison to earlier European trials, streptokinase (STK) is administered now at the earliest time possible after acute coronary thrombosis. In this series, STK was started 2.5 (±1.5) h after onset of chest pain, with reperfusion achieved approximately 1h later in 6 (55%) of 11 patients treated. Posttreatment angiograms will not be required to identify thrombolysis if noninvasive indicators will prvoide this information correctly. Early creatine kinase enzyme peaking 8 to 15 h after chest pain appears to be the most accurate marker available. Among untreated and unsuccessfully treated patients, creatine kinase peaking usually occurs 18‐36h after chest pain. A large intravenous STK loading dose of 1,500,000 IU produces a plasma concentration of approximately 500 IU/ml, equal to that concentration employed originally by intracoronary infusions. Such large doses have been employed in 60 patients thus far, without an unusual incidence or severity of hemorrhages. High dose, ultrashort‐term treatment for only 1 h is being investigated now. Systemic STK penetrates most “blind coronary pouches” and gains access to acute thrombi, as identified by radiocontrast material washout during angiography in patients with severe coronary occlusions. Streptokinase exerts a significant anticoagulant effect, not previous considered, which may be beneficial in the prevention of new clot formation and the rapid dissolution of acute coronary thrombi.
Effect of intra‐aortic balloon pumping on left ventricular function: Evaluation by radionuclide ventriculography
Authors: Iskandrian A. S. , Colby J. , Hakki A‐H. , Boston B. , Kane S. A.
Published: February 2009

The purpose of this study was to evaluate the effect of intra‐aortic balloon pumping (IABP) on left ventricular (LV) performance in ten patients (group I) with pump failure and in ten patients (group II) with angina pectoris. Left ventricular ejection fraction, regional ejection fraction, systolic chordal shortening and volumes were measured by first‐pass radionuclide ventriculography using a computerized multicrystal gamma camera. Patients in group I had significantly lower ejection fractions, regional ejection fractions and systolic chordal shortening and larger end‐diastolic and end‐systolic volumes than patients in group II, both on (p>0.0001) and off (p<0.004) IABP. With IABP, the ejection fraction increased by 0±0.5% in group I and 5.8±1.7% in group II (p=0.004); the regional ejection fraction increased by 0.1 ±0.9% in group I and 10.3±2.1% in group II (p=0.0004); the systolic chordal shortening increased by 1.1 ±0.6% in group I and 6.5 ±1.1% in group II (p=0.0006); the end‐diastolic volume decreased by ‐0.4±6% in group I and 14±4% in group II (p=0.07); and the end‐systolic volume decreased by ‐1±6% in group I and ‐21 ±5% in group II (p=0.02). Thus, IABP results in improvement in left ventricular performance in patients with angina pectoris but not in patients with pump failure.
Isolated left posterior fascicular block associated with acquired ventricular septal Defect
Authors: Rokey R. , Chahine R. A.
Published: February 2009

Isolated left posterior fascicular block in the absence of associated right bundle‐branch block is a rare electrocardiograpic finding. In view of its anatomy and the fact that it receives a dual blood supply, the posterior fascicle of the left bundle branch appears to be less vulnerable than the anterior fascicle or the right bundle. Mechanical disruption of the posterior fascicle can produce isolated left posterior fascicular block. This has been demonstrated in animal models. However, such oc‐curence has not been noted in humans. We present two cases of inferior wall myocardial infarction, complicated by rupture of the inferior septum, resulting in isolated left posterior fascicular block. The development of isolated left posterior fascicular block complicating myocardial infarction may, therefore, serve to alert to the possible underlying septal rupture.
Angina pectoris with angiographically normal coronary arteries: A clinical, hemodynamic, and metabolic study
Authors: Berland J. , Cribier A. , Cazor J. L. , Hecketsweiler B. , Letac B.
Published: February 2009

Seventy‐six patients with anginalike chest pain (ALCP) and angiographically normal coronary arteries (NCA) had a study of the myocardial metabolism at rest and during maximal atrial pacing. The results were compared with pain characteristics, electrocardiogram, left ventricular, and coronary hemodynamic data. Coronary blood flow (CBF) was measured by continuous ther‐modilution. At maximal paced heart rate, the study of the myocardial metabolism distinguished two groups: (1) a first group of 50 patients whose lactate extraction coefficient was equal to or exceeded 9 % and was considered as normal (Gr. I, K ≥9%); (2) a second group of 26 patients whose lactate extraction coefficient was below 9% (Gr. II, K<9%), significant of myocardial ischemia. In group I (K≥9%), chest pain was usually atypical (typical in only 25 % of cases) and rapid atrial pacing most often caused neither pain nor ECG changes. The hemodynamic and angiographic study showed minor alterations of the left ventricular cavity in 50% of cases. In group II (K<9%), chest pain was typical in 50% of the patients and maximal atrial pacing most often caused chest pain (85%) and ST‐segment depression (80%). In almost every case, the left ventricular and the coronary angiograms were normal. Only in this group, which had clinical, electrical, and metabolic signs of myocardial ischemia, could the diagnosis of angina pectoris with angiographically normal coronary arteries be upheld. However, resting CBF, % increase in CBF for an identical myocardial oxygen demand, and coronary resistances remained comparable in the two groups and no different from a group of 10 control subjects. This study confirms that myocardial ischemia occurs during rapid atrial pacing in 30% of patients with ALCP and NCA, with no obvious explanation, since coronary hemodynamics remain normal. In the remaining 70% of patients where no myocardial ischemia can be demonstrated minor forms of cardiomyopathy or mitral valve prolapse can often be shown.
Campylobacter jejuni myocarditis
Authors: Florkowski C. M. , Ikram R. B. , Crozier I. M. , Ikram H. , Berry M. E.
Published: February 2009

A case of Campylobacter jejuni (C. jejuni) myocarditis in a young man is described. C. jejuni was isolated from the patient's stools and he developed specific antibodies to this organism. Tests for other etiological agents (Salmonella, Shigella, Brucella abortus, β‐hemolytic streptococcus Group A, Treponema pallidum and coxsackievirus B) proved negative.
Pseudocoarctation of the aortic arch in a patient with turner's syndrome
Authors: Klein L. W. , Levin J. L. , Weintraub W. S. , Agarwal J. B. , Helfant R. H.
Published: February 2009

Pseudocoarctation of the aortic arch is a rare congenital anomaly which resembles true coarctation by the presence of a narrowing in the descending thoracic aorta immediately distal to the origin of the left subclavian artery. However, it is differentiated from that entity by the absence of a significant hemodynamic obstruction and by the presence of aneurysmal dilatation proximal and distal to the area of narrowing. As a result, the commonly observed clinical findings of coarctation such as a prominent collateral circulation and decreased blood pressure in the lower extremities are not observed. “Kinking” or “buckling” are common adjectives used to describe the roentgenographic appearance of the aortic arch in this condition. The association of various congenital cardiac abnormalities with pseudocoarctation has been reported, and are similar to those commonly seen with true coarctation. We now present the first reported case of pseudocoarctation associated with a probable bicuspid aortic valve in a patient with Turner's syndrome.
Noninvasive recording of his bundle electrograms using vectorial leads system
Authors: Nojima K. , Otsuka K. , Otsuka K. , Seto K. , Mori H.
Published: February 2009

His bundle electrograms were recorded in 8 rats by a signal averaging technique using the Takayasu vectorial lead system. Animals were anesthetized and placed in the prone position. The polarity of three orthogonal leads were: the X axis, from right to left; the Y axis, from top to bottom; the Z axis, from back to front. Potentials from the X, Y, and Z leads were amplified by 20,000 with high‐pass 12 dB/octave filtering at 80 Hz, and signal averaging of 2000 beats was performed at a sampling interval of 100 μs. The His bundle potential could be clearly defined in all 8 rats. The mean amplitude of the His potential was larger in the X‐axis (23.6±9.2μV) or the Y‐axis (28.4±14.5μV) than the Z‐axis lead (11.5±8.6μV). Directions of the His potential vectors were to the left in 5 of 8 rats (62.5%), to the caudal in 4 of 6 rats (66.7%), and to the dorsal site in 6 of 8 rats (75.0%). This vectorial lead system, devised in accordance with McFee and Johnston's theory on lead field, was useful for recording His bundle electrograms.
Angioscopic visualization of blood vessel interior in animals and humans
Authors: Litvack F. , Grundfest W. S. , Lee M. E. , Carroll R. M. , Foran R. , Chaux A. , Berci G. , Rose H. B. , Matloff J. M. , Forrester J. S.
Published: February 2009

The purpose of this study is to describe the use of angioscopes in flowing bloodstreams of animals and humans, to demonstrate the ability to precisely deliver laser energy to an intravascular target using visual guidance and to determine the information content and spatial content of angioscopy. Angioscopy was performed in 5 living dogs, 16 cadaver vascular segments, and 14 patients at the time of peripheral or coronary bypass surgery. Five canine femoral artery segments received angioscopically directed intravascular Nd: YAG laser irradiation. We were able to precisely direct the laser irradiation to predetermined intimal targets. Gross tissue injury varied from none to carbonization and vascular perforation, depending on incident energy. Using a variety of flexible fiberoptic endoscopes ranging in diameter from 1.5 to 3.7 mm, we were able to visualize intravascular structures including plaque, suture lines, venous valves, and thrombi in living patients. No patient incurred complications of any sort. We conclude that angioscopy using flexible en doscopes can be performed safely, can provide clinically useful information, and may provide a means for delivering visually directed intravascular laser irradiation.
Changes in plasma catecholamine concentrations in patients with coronary heart disease during pacing and physical exercise
Authors: Dominiak P. , Grobecker H. , Delius W.
Published: February 2009

To study the difference in sympathetic activity during pacing the right atrium or during physical exercise in patients with coronary heart disease, we investigated circulating plasma catecholamine concentrations in the coronary sinus and brachial artery radioenzymatically in 11 male patients with well documented coronary artery disease. Heart rate was increased stepwise 20 beats/min from 90 beats/min up to 150 beats/min by pacing the right atrium and physical exercise was performed by increasing work load stepwise by 25 from 25 up to 100 W on an ergometric bicycle. Plasma noradrenaline and adrenaline concentrations were increased significantly only during physical exercise. In addition, there was an increase in arterial‐coronary sinus noradrenaline difference during graded physical exercise, whereas no further release of noradrenaline from the myocardium occurred during pacing. An enhanced cardiac sympathetic tone in patients with coronary heart disease is discussed. It is suggested that atrial pacing is not an adequate stimulus evoking an overall increase of cardiac and peripheral sympathetic tone.
Mitral valve prolapse syndrome with coronary artery spasm: A possible cause of recurrent ventricular tachyarrhythmia
Authors: Sakuma T. , Kakihana M. , Togo T. , Matsuda M. , Ogawa T. , Sugishita Y. , Ito I. , Kurusu T.
Published: February 2009

A 54‐year‐old man with mitral valve prolapse syndrome diagnosed by echochardiography complained of anginal pain associated with ventricular tachyarrhythmia. One day he suddenly lost consciousness, and ECG at that time revealed ventricular fibrillation. Thereafter, he developed ST elevation, sporadic premature ventricular contractions, and R on T phenomenon leading to ventricular fibrillation during the attack of anginal pain. His coronary arteriogram was normal. This case implies that coronary artery spasm may be one of the causes of chest pain and ventricular tachyarrhythmias in patients with mitral valve prolapse syndrome.
A peculiar extra heart sound after artificial pneumothorax in congenital pericardial defect: A diagnostic clue
Authors: Hayashi Y. , Araki H. , Yamada A. , Tomoike H. , Nakamura M.
Published: February 2009

A 37‐year‐old man was admitted to the hospital in order to evaluate the cause of systolic ejection heart murmur and to treat his easy fatigability. The chest roentgenogram showed a marked protrusion of the left second and third arches of the cardiac silhouette. At the diagnostic procedure, 200 ml of air was injected into the left thoracic space. The chest roentgenogram revealed no sign of pneumopericardium, but an abnormal extra heart sound was audible. Addition of another 200 ml of air was needed to reveal a pneumopericardium on the chest roentgenogram. A peculiar extra heart sound after artificial pneumothorax may be useful for the early recognition of congenital pericardial defect.
Cardiovascular response to static contraction in borderline hypertension
Authors: Seals D. R. , Hanson P. G. , Washburn R. A. , Painter P. L. , Ward A. , Nagle J.
Published: February 2009

Nine young males with borderline hypertension (BH) (mean age ± SD, 25 ± 5 yr) and 13 young male normotensive controls (NT) (24 ± 3 yr) were studied to determine their cardiovascular responses to small and large muscle static contractions. The subjects performed one‐arm handgrip and two‐leg extension in a randomly assigned order for 3 min at 30 % of maximal voluntary contraction. Mean intra‐arterial blood pressure (MABP), heart rate (HR), and tension were measured throughout the contractions. Borderline hypertensive patients had a higher MABP at rest (p< 0.005) and at the end of both types of static contractions (p<0.05). The average increases in MABP from rest to the end of exercise (ΔMABP) were slightly greater for the BH patients (6 mmHg), but these differences were not significant (p>0.1). However, a greater percentage of BH patients were hyperreactive to handgrip (ΔBP < 35 mmHg) and leg extension (ΔBP <40 mmHg) when compared to controls. These data indicate that, in general, young men with borderline hypertension demonstrate normal cardiovascular regulation in response to static contraction, but that a portion of this population may be hyperreactive to this type of circulatory stress.
Delayed shotgun pellet migration to the right ventricle
Authors: Levi B. , Sainsbury C. R. , Scharf D. L.
Published: February 2009

Multiple case reports of bullet emboli to the heart have been documented. A unique clinical situation is presented of a patient who sustained a shotgun injury to the buttock, with retained pellets, who 7 to 10 years later demonstrated intravascular migration of one of the pellets to the intracardiac position.
A case of wolff‐parkinson‐white syndrome: Conduction through the kent bundle seems to depend on the serum potassium level
Authors: Nakahara Y. , Nakahara Y. , Matsuyama E.
Published: February 2009

A 72‐year‐old man with Wolff‐Parkinson‐White syndrome and sick sinus syndrome had colon cancer, suggesting that the conduction of the Kent bundle depends on the serum potassium level. Because of severe diarrhea or furosemide administration, the serum potassium level in this patient was sometimes low. When it was less than 3.0 mEq/1 delta wave or re‐entrant tachycardia via the Kent bundle occurred. These were suppressed by the administration of potassium. On the other hand, when the serum potassium level was normal or high, neither effect was noted, and electrophysiological studies, done when the level was 3.2 mEq/1, showed no evidence of conduction by the accessory pathway. This suggests that conduction through the Kent bundle depends on the serum potassium level.
Paradoxical ventricular septal motion with right ventricular dilatation as a manifestation of pure pressure overload due to pulmonary veno‐occlusive disease
Authors: Zee‐Cheng C. S. , Gibbs H. R.
Published: February 2009

Paradoxical interventricular septal motion with right ventricular dilatation has been considered the hallmark of right ventricular volume overload. We report a 43‐year‐old woman with severe pulmonary hypertension due to pulmonary veno‐occlusive disease who exhibited these echocardiographic abnormalities. Right ventricular volume overload was excluded by physical examination, echocardiography with saline contrast study and by cardiac catheterization, angiography, and shunt study. These echocardiographic findings are thus not pathognomonic of right ventricular volume overload and can be seen with pressure overload as well.
The significance of repeated exercise testing with thallium‐201 scanning in asymptomatic diabetic males
Authors: Rubler S. , Fisher V.J.
Published: February 2009

This study was conducted with asymptomatic middle‐aged male subjects with diabetes mellitus to detect latent cardiac disease using noninvasive techniques. One group of 38 diabetic males (mean age 50.5±10.2 years) and a group of 15 normal males (mean age 46.9±10.0 years) participated in the initial trial; 13 diabetic patients and 7 control subjects were restudied 1‐2 years later. Maximal treadmill exercise with a Bruce protocol and myocardial scintigraphy with thallium‐201(201Tl) were used. Diabetic subjects on initial examination and retesting achieved a lower maximal heart rate and duration of exercise than control subjects. Abnormal electrocardiographic changes, thallium defects, or both were observed in 23/38 diabetic males (60.5%) on the first study and only one 65‐year‐old control subject had such findings. On retesting, the control subjects had no abnormalities while 76.9% of diabetic subjects had either 201Tl defects or ECG changes. We conclude that despite the fact that none of diabetic males had any clinical evidence or̀ symptoms of heart disease, this high‐risk group demonstrated abnormalities on exercise testing that merit careful subsequent evaluation and followup and could be an effective method of detecting early cardiac disease.
Difference in the response to isoproterenol between asymmetric septal hypertrophy and symmetric hypertrophy in patients with hypertrophic cardiomyopathy
Authors: Iida K. , Sugishita Y. , Matsuda M. , Yamaguchi T. , Ajisaka R. , Matsumoto R. , Fujita T. , Yukisada K. , Ito I.
Published: February 2009

The response to isoproterenol was studied in 9 patients with hypertrophic cardiomyopathy (HCM) and asymmetric septal hypertrophy (ASH), 9 patients with HCM and symmetric hypertrophy (SH), and 9 normal controls (NC), using digitized M‐mode echocardiography. There was no significant difference in fractional shortening (FS) between ASH and SH, nor between SH and NC before isoproterenol infusion. During isoproterenol infusion, however, FS was significantly greater in ASH (60±6%) than in SH (53±7%) and NC (49±5%) (p<0.05, p<0.01, respectively), and normalized peak rate of change of left ventricular dimension during systole (pVs) was greater in ASH (7.7 ± 1.5/s) than in SH (5.2±0.8/s) and in NC (4.9±0.8/s) (p<0.001, p<0.001, respectively). This study shows that the response to isoproterenol of ASH differs from those of SH and of NC and suggests hypersensitivity of the beta‐adrenergic receptor system in ASH and the possibility that ASH is a different clinical entity than SH.
Malignant schwannoma of the heart
Authors: Morishita T. , Yamazaki J. , Ohsawa H. , Uchi T. , Kawamura Y. , Okuzumi K. , Nakano H. , Wakakura M. , Okamoto K. , Koyama N. , Komatsu H.
Published: February 2009

Primary cardiac tumor is an extremely rare disease entity. Only three cases of primary malignant cardiac schwannoma, the subject of this report, have been recorded in Japan. Recently, we encountered a case of malignant schwannoma in which retention of pericardial effusion was the first clinical finding. This case was a 30‐year‐old female, who had dyspnea at work, general fatigue, and fever. Striking cardiac expansion was seen, with a cardiothoracic ratio (CTR) of 69% on chest x‐ray. Two‐dimensional echocardiograms showed a large volume of pericardial effusion between the side wall of the left ventricle and the epicardium, and the presence of a parenchymatous tumor. An increase in tumor size was detected on chest computer tomography (CT) scan. Using a pump oxygenator, median sternotomy was performed to reach the epicardium. A pale yellow, soft tumor was seen in the left atrium near the left ventricle. Histologically, the patient was diagnosed as having a malignant schwannoma. We have reported a case of primary malignant schwannoma which was surmised to have arisen from the boundary between the atrium and the ventricle.
Endocardial late potentials recorded during sinus rhythm in man: Incidence in different cardiac disease states
Authors: Bethge K.‐P. , Gonska B.‐D. , Kreuzer H. , Kühn R. , Sauthoff G. , Beie C. , Saathoff H.
Published: February 2009

In a prospective study, 100 patients with various cardiac diseases not selected on the basis of previous ventricular arrhythmias underwent left ventricular endocardial mapping. With 10 different positions of the quadripolar catheter per patient, 90 of the 100 patients showed late potentials. These findings were documented in 50 of 52 patients with coronary heart disease compared to 26 of 34 patients with dilative cardiomyopathy (p<0.025). Late potentials in diastole were the most frequent type of abnormal electrogram, found in 82 patients. Fractionated electrograms were documented in 43 patients. They were seen in 27 (52%) coronary patients more often than in 8 (24%) patients with dilative cardiomyopathy (p<0.025). Onset of fractionated electrograms in coronary patients was somewhat later (301 ± 177 ms after the QRS) than in the cardiomyopathy group (263 ± 141 ms). The duration was longer (189 ±114 ms) in the former group than in the latter (148±87 ms). Thus, endocardial late potentials are not uncommon in patients with various cardiac diseases. The more frequent occurrence in coronary heart disease and the higher frequency of fractionated electrograms may indicate a more inhomogeneous, patchy type of fibrosis in the ischemically diseased myocardium.
Postinfarction left ventricular pseudoaneurysm: Echocardiographic diagnosis and prolonged survival in three patients
Authors: Otto C. M. , Stratton J. R.
Published: February 2009

Both echocardiography and radionuclide angiography have been proposed as noninvasive modalities for the diagnosis of left ventricular pseudoaneurysm. In the only three cases seen at our institution over the past five years, this diagnosis was missed with radionuclide blood pool imaging, while two‐dimensional echocardiography demonstrated the typical features of a pseudoaneurysm. Our patients were asymptomatic and diagnosis was made incidentally 4 to 6 years after myocardial infarction. Although the patients survived an extended period without surgery, the reported incidence of rupture is high, and prophylactic surgical repair probably is indicated. It is likely that the increased use of noninvasive cardiac imaging techniques will lead to the detection of other cases of unsuspected left ventricular pseudoaneurysm. Two‐dimensional echocardiography appears superior to planar radionuclide ventriculography in establishing the diagnosis.
Heart with circulatory failure secretes and processes atrial natriuretic peptide in a manner different from normal heart
Authors: Matsubara H. , Umeda Y. , Nishikawa M. , Yamane Y. , Kurimoto T. , Iwasaka T. , Inada M.
Published: February 2009

The role of catecholamine in atrial natriuretic peptide (ANP) secretion and its secretory mechanism in normal humans is not well defined; therefore, we studied the relationship among ANP, catecholamine, and atrial pressures in 25 patients without cardiovascular disease and in 35 patients with chronic congestive heart failure (CHF, 20 in mitral valve disease and 15 in dilated cardiomyopathy). In patients without cardiovascular disease, right atrial pressure at rest showed a positive correlation (r = 0.80, p>0.001) with ANP concentration, whereas left atrial pressure did not. The relation narrowed (r = 0.82) when the bicycle ergometer exercise in the supine position was conducted. Neither adrenalin nor noradrenalin significantly correlated with ANP concentration. In patients with mitral valve disease and dilated cardiomyopathy, the significant relations (r = 0.56 p>0.001, r = 0.85 p>0.001, respectively) between left atrial pressures and ANP concentrations at rest were observed, and following exercise, induced more significant relations. Right atrial pressures did not correlate positively with ANP concentrations. The increments of ANP concentrations induced by exercise load were markedly reduced compared with those of patients without cardiovascular disease. Although concentrations of both noradrenalin and adrenalin in patients with mitral valve disease and dilated cardiomyopathy at rest were much higher than those without cardiovascular disease, only noradrenalin had a highly positive correlation with ANP concentrations (r = 0.88 p> 0.001, r = 0.78 p>0.001, respectively). Furthermore, the circulating ANP molecular weight forms in all patients studied were analyzed by gel chromatography coupled with radioimmunoassay. In contrast to the predominant form of α‐ANP in patients without cardiovascular disease, larger molecular forms occurred in most patients with CHF. We conclude that ANP secretion from the heart of patients with CHF is regulated not only by atrial pressure but noradrenalin, and that its processing mechanism is different from that of the normal heart.
Prognostic value of supine scintigraphic heart function and simultaneous conventional exercise response in patients after myocardial infarction
Authors: Fridrich L. , Gassner A. , Sommer G. , Klicpera M.
Published: February 2009

A total of 240 survivors of one or more myocardial infarctions were consecutively admitted to perform supine exercise radionuclide ventriculography. Within 3 years after the test, 22 died; this group was compared to an age‐matched control group of 22 survivors for left and right ventricular function during rest, exercise, and simultaneously assessed exercise performance as well as ECG variables. Evaluation of 3‐year survival by linear discriminant analysis revealed an accuracy of 82% for discriminant models using ECG and exercise performance variables. Implementation of resting left ventricular ejection fraction and change of right ventricular ejection fraction during exercise, as well as scintigraphic presence or absence of dyskinesia, improved the accuracy of the model to 91% of correctly classified patients.