bluuebunny/crossref_metadata_2025 huggingface dataset:
ADJUSTING FIXED‐RATIO SCHEDULES IN THE SQUIRREL MONKEY
Authors: Kelleher Roger T. , Fry William , Cook Leonard
Published: March 2006

On an adjusting schedule of reinforcement, a parameter of the schedule is varied as a function of some characteristic of the animal's performance. In Experiment I, the fixed‐ratio response requirement was varied as a function of the time that elapsed before the animal started responding in each fixed‐ratio (initial pause). When initial pauses were shorter than a specified duration, the response requirement was increased; when they were longer than the specified duration, the response requirement was decreased. Specified durations of 1, 2, 4, 8, and 15 min were studied. The average response requirement maintained by each monkey was directly related to the length of the specified duration of initial pause. In Experiment II, the fixed‐ratio response requirement was constant, but reinforcement occurred only when the initial pause was longer than a specified duration. The average durations of initial pauses were directly related to the length of the specified duration and to the response requirement. Meprobamate consistently decreased the average durations of initial pauses.
EFFECT OF SHOCK DURATION ON SHOCK‐INDUCED FIGHTING1
Authors: Azrin N. H. , Ulrich R. E. , Hutchinson R. R. , Norman D. G.
Published: March 2006

Shock‐induced fighting between paired rats was a direct function of the duration of the shock stimulus. Continued presentations of the shock partially reversed this direct relationship.
Titelbild: Autonomous Fueled Mechanical Replication of Nucleic Acid Templates for the Amplified Optical Detection of DNA (Angew. Chem. 14/2006)
Authors: Weizmann Yossi , Cheglakov Zoya , Pavlov Valeri , Willner Itamar
Published: March 2006

Eine katalytische Schere für den empfindlichen Nachweis einer Ziel‐DNA, einer Tay‐Sachs‐Fehlfunktionsmutante, wird von I. Willner et al. in ihrer Zuschrift auf S. 2296 ff. vorgestellt. Auf dem Titelbild wird eine maßgeschneiderte Nucleinsäurehaarnadel‐Sonde (oben) durch Hybridisierung mit der Analyt‐DNA geöffnet, was die Bildung der DNA‐Schere (Mitte) aktiviert. Diese löst das autonome Schneiden eines Treibstoffsubstrats aus, wodurch die katalytische Schere repliziert und ein fluoreszierendes Produkt als optisches Ausgabesignal erzeugt wird.
Technology, genres, and value change: The case of little magazines
Authors: Paling Stephen , Nilan Michael
Published: March 2006

Producers in creative genres are frequently motivated by goals that put those producers in opposition to popular culture and marketplace pressures. Questions about whether those goals reflect values that belong specifically to print culture, or whether those values will continue to motivate producers in creative genres after the introduction of online technology, have not been answered empirically. Previous studies of genre change have been among those that have focused on the ability of human actors to use information technology to alter those genres as social structures. However, these studies have focused on generic artifacts rather than on the creative values that motivated the creation of those artifacts. Editors of small literary magazines (generally referred to as little magazines) make ideal subjects for this study. Creative values play an important role in their decisions, and they frequently publish poetry, fiction, and other work that stand in opposition to popular culture and literature. This study proposed and evaluated a conceptual framework for anticipating whether editors of little magazines will use online technologies to reinforce or alter the values characteristic of their genre. The study found that the values posited in the conceptual framework fit the goals expressed by little magazine editors. Not all editors held those values equally, however. These findings suggest that producers in creative genres can use online technology in ways that actually reflect an intensification of those values. The concept of intensifying use of technology (IUT) was posited to explain the differences.
Relevance judgment: What do information users consider beyond topicality?
Authors: Xu Yunjie (Calvin) , Chen Zhiwei
Published: March 2006

How does an information user perceive a document as relevant? The literature on relevance has identified numerous factors affecting such a judgment. Taking a cognitive approach, this study focuses on the criteria users employ in making relevance judgment beyond topicality. On the basis of Grice's theory of communication, we propose a five‐factor model of relevance: topicality, novelty, reliability, understandability, and scope. Data are collected from a semicontrolled survey and analyzed by following a psychometric procedure. Topicality and novelty are found to be the two essential relevance criteria. Understandability and reliability are also found to be significant, but scope is not. The theoretical and practical implications of this study are discussed.
The scientific network of surfactants: Structural analysis
Authors: Bailón‐Moreno Rafael , Jurado‐Alameda Encarnación , Ruiz‐Baños Rosario
Published: March 2006

The scientific network of the surfactants and related subjects has been analyzed with the CoPalRed© knowledge system. The actors studied have been countries, research centers and laboratories, researchers, and journals. The thematic map of the major research areas has been established. Most of the research areas, and those that have the greatest representation in terms of number of documents, are related to physics and chemistry. However, biochemistry and cell biology, medicine (pediatrics and pulmonary physiology), and, to a lesser extent, veterinary medicine and food science and technology are also noteworthy in the field of surfactants, which presents a markedly multidisciplinary profile.
Exploring the role of medical and consumer literature in the diffusion of information related to hormone therapy for menopausal women
Authors: Genuis Shelagh K.
Published: March 2006

Using content analysis, this study explored the role of the literature in the diffusion of new information; the influence of the literature on the innovation‐decision process; and how the concept of tie strength can contribute to a greater understanding of the role of the literature in information transmission. Diffusion of innovations and strength of weak ties theories provided the framework that informed this research, and an illustrated medical case study, changing practices related to hormone therapy for menopausal women, provided context for the study. Findings suggest that published literature impacts the innovation‐decision process and thus plays an integral role in the diffusion of medical innovation to physicians and consumers; that the view of literature as a bridging “weak tie” in a multifactor communication network allows for a more comprehensive understanding of the role of published literature in information diffusion; and that medical and lay articles are not neutral channels, they function to provide information, reinforce knowledge, and produce and shape meaning.
A Bayesian model that predicts the impact of Web searching on decision making
Authors: Lau Annie Y.S. , Coiera Enrico W.
Published: March 2006

This study aimed to develop a model for predicting the impact of information access using Web searches, on human decision making. Models were constructed using a database of search behaviors and decisions of 75 clinicians, who answered questions about eight scenarios within 80 minutes in a controlled setting at a university computer laboratory. Bayesian models were developed with and without bias factors to account for anchoring, primacy, recency, exposure, and reinforcement decision biases. Prior probabilities were estimated from the population prior, from a personal prior calculated from presearch answers and confidence ratings provided by the participants, from an overall measure of willingness to switch belief before and after searching, and from a willingness to switch belief calculated in each individual scenario. The optimal Bayes model predicted user answers in 73.3% (95% CI: 68.71 to 77.35%) of cases, and incorporated participants' willingness to switch belief before and after searching for each scenario, as well as the decision biases they encounter during the search journey. In most cases, it is possible to predict the impact of a sequence of documents retrieved by a Web search engine on a decision task without reference to the content or structure of the documents, but relying solely on a simple Bayesian model of belief revision.
The interleukin‐15/interleukin‐15 receptor system as a model for juxtacrine and reverse signaling
Authors: Bulfone‐Paus Silvia , Bulanova Elena , Budagian Vadim , Paus Ralf
Published: March 2006

Interleukin‐15 (IL‐15) is a pleiotropic cytokine of the 4 α‐helix bundle family, which binds to a receptor complex that displays common elements with the IL‐2 receptor and a unique high‐affinity α chain. This review focuses on juxtacrine and reverse signaling levels in the IL‐15/IL‐15R system. Specifically, we discuss how agonistic stimulation of membrane‐bound IL‐15 induces phosphorylation of members of the MAP kinase family and of focal adhesion kinase (FAK), thereby upregulating processes including cytokine secretion, cell adhesion and migration. In addition, we explore IL‐15 trans‐presentation and intracellular signaling, and define promising molecular targets for future pharmacological intervention in infectious diseases and immunological disorders. These frontiers in IL‐15/IL‐15Rα research serve as highly instructive examples for key concepts, unsolved problems and therapeutic opportunities in juxtacrine and reverse signaling in general. BioEssays 28: 362–377, 2006. © 2006 Wiley Periodicals, Inc.
Why photoreceptors die (and why they don't)
Authors: Fain Gordon L.
Published: March 2006

Light can kill the photoreceptors of the eye, not only very bright direct sunlight, but more moderate illumination if the light is present continuously. Recent experiments show that rod apoptosis can be triggered by strong and constant activation of transduction, and that death can be prevented if transduction is inhibited even though the eye is illuminated. Vitamin A deficiency and genetically inherited diseases, such as some forms of retinitis pigmentosa and Leber congenital amaurosis, appear to kill like this: transduction is activated at a high rate and continuously, and this causes the rods to die. Why does transduction kill? Our best guess is that continuous activation produces a prolonged lowering of the Ca2+ concentration, which is also thought to kill neurons in tissue culture and during the development of the nervous system. To prevent death in constant light, rods have evolved protective mechanisms including modulation of channels and ion transport to keep the Ca2+ from going too low. Prolonged light exposure also causes migration of transduction proteins from one part of the cell to another and a reversible shortening of the rod outer segments, the part of the cell that contains the pigment rhodopsin. All of these mechanisms are at work in the normal eye to reduce transduction and prevent the Ca2+ concentration from dropping too low for too long a time. That most of us retain our vision our entire lives is a testament to their effectiveness. BioEssays 28: 344–354, 2006. © 2006 Wiley Periodicals, Inc.
Cell cycle control by oscillating regulatory proteins in Caulobacter crescentus
Authors: Holtzendorff Julia , Reinhardt Jens , Viollier Patrick H.
Published: March 2006

Significant strides have been made in recent years towards understanding the molecular basis of cell cycle progression in the model bacterium Caulobacter crescentus. At the heart of cell cycle regulation is a multicomponent transcriptional feedback loop, governing the production of successive regulatory waves or pulses of at least three master regulatory proteins. These oscillating master regulators direct the execution of phase‐specific events and, importantly, through intrinsic genetic switches not only determine the length of a given phase, but also provide the driving force that catapults the cell into the next stage of the cell cycle. The genetic switches act as fail safe mechanisms that prevent the cell cycle from relapsing and thus govern the ordered production and the periodicity of these regulatory waves. Here, we detail how the master regulators CtrA, GcrA and DnaA coordinate cell cycle progression and polar development in Caulobacter. BioEssays 28: 355–361, 2006. © 2006 Wiley Periodicals, Inc.
Duplication and divergence in humans and chimpanzees
Authors: Wooding Stephen , Jorde Lynn B.
Published: March 2006

It has become a truism that we humans are genetically about 99% identical to chimpanzees. The origins of this assertion are clear: among early studies of DNA sequences, nucleotide identity between humans and chimpanzees was found to average around 98.9%.1 However, this figure is correct only with respect to regions of the genome that are shared between humans and chimpanzees. Often ignored are the many parts of their genomes that are not shared. Genomic rearrangements, including insertions, deletions, translocations and duplications, have long been recognized as potentially important sources of novel genomic material2,3 and are known to account for major genomic differences between humans and chimpanzees.4 Further, such changes have been implicated in a number of genetic disorders, such as DiGeorge, Angelman/Prader‐Willi and Charcot‐Marie‐Tooth syndromes5. BioEssays 28: 335–338, 2006. © 2006 Wiley Periodicals, Inc.
When Brachyury meets Smad1: the evolution of bilateral symmetry during gastrulation
Authors: Marcellini Sylvain
Published: March 2006

Understanding the events that led to the emergence of the bilaterians is a daunting task, impaired by the huge evolutionary gap separating us from the pre‐Cambrian. During gastrulation, the expression of the transcription factor Brachyury is remarkably well conserved around the blastopore of bilaterians and cnidarians. Only the bilaterian Brachyury proteins, however, share a distinctive N‐terminal sequence not found in outgroups such as cnidarians, sponges or placozoans. We now know that, in vertebrates, this N‐terminal domain confers specific transcriptional activity, by recruiting Smad1, the first identified co‐factor for Brachyury. Smad1 is an effector of the BMP pathway, and has been isolated in bilaterians and cnidarians. Here, I propose that the protein–protein interaction between Brachyury and Smad1 represents an evolutionary novelty of the Urbilateria. The gain of the N‐terminal domain might have been selected to spatially modulate the activity of Brachyury, thereby facilitating the establishment of bilateral symmetry during gastrulation movements. BioEssays 28: 413–420, 2006. © 2006 Wiley Periodicals, Inc.
Polycomb, trithorax and the decision to differentiate
Authors: Ringrose Leonie
Published: March 2006

For stem cells, life is full of potential: they have a high capacity to proliferate and a wide choice of future identities. When they differentiate, cells leave behind this freedom and become ever more committed to a single fate. Intriguingly, the Polycomb and Trithorax groups of proteins are vital to the very different natures of both stem cells and differentiated cells, but little is known about how they make the transition from one cell type to the other. A recent paper1 throws light on this mystery, showing that the Polycomb proteins dramatically change their behaviour at a crucial moment of differentiation. BioEssays 28: 330–334, 2006. © 2006 Wiley Periodicals, Inc.
Compositional complementarity and prebiotic ecology in the origin of life
Authors: Hunding Axel , Kepes Francois , Lancet Doron , Minsky Abraham , Norris Vic , Raine Derek , Sriram K. , Root‐Bernstein Robert
Published: March 2006

We hypothesize that life began not with the first self‐reproducing molecule or metabolic network, but as a prebiotic ecology of co‐evolving populations of macromolecular aggregates (composomes). Each composome species had a particular molecular composition resulting from molecular complementarity among environmentally available prebiotic compounds. Natural selection acted on composomal species that varied in properties and functions such as stability, catalysis, fission, fusion and selective accumulation of molecules from solution. Fission permitted molecular replication based on composition rather than linear structure, while fusion created composomal variability. Catalytic functions provided additional chemical novelty resulting eventually in autocatalytic and mutually catalytic networks within composomal species. Composomal autocatalysis and interdependence allowed the Darwinian co‐evolution of content and control (metabolism). The existence of chemical interfaces within complex composomes created linear templates upon which self‐reproducing molecules (such as RNA) could be synthesized, permitting the evolution of informational replication by molecular templating. Mathematical and experimental tests are proposed. BioEssays 28: 399–412, 2006. © 2006 Wiley Periodicals, Inc.
Decoding the rice genome
Authors: Vij Shubha , Gupta Vikrant , Kumar Dibyendu , Vydianathan Ravi , Raghuvanshi Saurabh , Khurana Paramjit , Khurana Jitendra P. , Tyagi Akhilesh K.
Published: March 2006

Rice cultivation is one of the most important agricultural activities on earth, with nearly 90% of it being produced in Asia. It belongs to the family of crops that includes wheat, maize and barley, and it supplies more than 50% of calories consumed by the world population. Its immense economic value and a relatively small genome size makes it a focal point for scientific investigations, so much so that four whole genome sequence drafts with varying qualities have been generated by both public and privately funded ventures. The availability of a complete and high‐quality map‐based sequence has provided the opportunity to study genome organization and evolution. Most importantly, the order and identity of 37,544 genes of rice have been unraveled. The sequence provides the required ingredients for functional genomics and molecular breeding programs aimed at unraveling intricate cellular processes and improving rice productivity. BioEssays 28: 421–432, 2006. © 2006 Wiley Periodicals, Inc.
Hydrocortisone made in yeast: Metabolic engineering turns a unicellular microorganism into a drug‐synthesizing factory
Authors: Dumas Bruno , Brocard‐Masson Corinne , Assemat‐Lebrun Karine , Achstetter Tilman
Published: March 2006

Inspired by the successful work of converting Saccharomyces cerevisiae into an microorganism capable of synthesizing hydrocortisone, a 27‐carbon molecule, from ethanol, a 2‐carbon molecule, this review provides an overview of the potential of yeast as a recombinant organism in the 21st century. Yeast has been used by man for more than 6000 years, and is still paving the way to new discoveries. It was the first eukaryotic organism to be sequenced, in 1996, and the first to produce hydrocortisone in 2003. In addition, extensive genome–wide analyses have been performed with yeast. In this review, we discuss the pros and cons of using yeast to produce small therapeutic molecules. It is obvious that S. cerevisiae has a cutting edge advantage of being a well–known organism and time will tell if yeast “biohydrocortisone” is a unique example or the beginning of a long list of yeast bioproducts. Other organisms, such as plants and bacteria, are competing with yeast. Bacteria produce a wealth of marketed molecules and plants are capable of producing extremely complex molecules with an unbeatable yield. However, S. cerevisiae offers a unique mix of the simplicity of a recombinant organism combined with the complexity of a eukaryote.
Yeast models of human mitochondrial diseases: from molecular mechanisms to drug screening
Authors: Schwimmer Christine , Rak Malgorzata , Lefebvre‐Legendre Linnka , Duvezin‐Caubet Stéphane , Plane Guillaume , di Rago Jean‐Paul
Published: March 2006

Mitochondrial diseases are rare diseases most often linked to energy in the form of ATP‐depletion. The high number of nuclear‐ and mitochondrial‐DNA‐encoded proteins (>500), required for ATP production and other crucial mitochondrial functions such as NADH re‐oxidation, explains the increasing number of reported disorders. In recent years, yeast has revealed to be a powerful model to identify responsible genes, to study primary effects of pathogenic mutations and to determine the molecular mechanisms leading to mitochondrial disorders. However, the clinical management of patients with mitochondrial disorders is still essentially supportive. Here we review some of the most fruitful yeast mitochondrial disorder models and propose to subject these models to highthroughput chemical library screening to prospect new therapeutic drugs against mitochondrial diseases.
Catheter‐based decompression of the left atrium in patients with hypoplastic left heart syndrome and restrictive atrial septum is safe and effective
Authors: Gossett Jeffrey G. , Rocchini Albert P. , Lloyd Thomas R. , Graziano Joseph N.
Published: March 2006

Infants with hypoplastic left heart syndrome (HLHS) and restrictive or intact atrial septum (rAS) present with cyanosis, pulmonary edema, and are critically ill. A previous report from our institution on emergent Norwood for HLHS with rAS showed 10% survival. We hypothesized that transcatheter left atrial (LA) decompression in HLHS with rAS would safely and effectively relieve LA hypertension, improve oxygenation, and improve Norwood survival. Between 1996 and 2004, 30 patients with HLHS and rAS underwent cardiac catheterization for pre‐Norwood intervention. Twenty‐eight atrial septostomies were performed: 23 static balloon dilations, 4 Rashkind septostomies, and 1 intra‐atrial stent. Two procedures were aborted due to perforation (n = 1) or inability to enter the LA (n = 1). Eight total patients required surgical septectomy, for a failure rate of 27%. There were no catheter‐related mortalities, although two patients died within 36 hr of the procedure after surgical septectomy. Major complications occurred in three patients (10%)—atrial perforations requiring intervention. Mean atrial septal defect gradient fell from 16.7 ± 4.9 to 6.3 ± 3.4 mm Hg (P < 0.001; n = 18). Mean LA pressure dropped from 21.8 ± 5.5 to 13.1 ± 6.5 mm Hg (P < 0.001; n = 16). Mean PaO2 rose from 29.5 ± 9.1 to 36.5 ± 5.1 torr (P < 0.001; n = 23). Seventeen of 30 patients (57%) survived to discharge from Norwood. Thirteen have undergone hemi‐Fontan and nine Fontan. Sixteen of 22 successful decompressions (73%) survived to discharge. Transcatheter decompression of the LA for patients with HLHS and rAS can be performed safely, reduces the transatrial gradient, and improves oxygenation. Catheter intervention improves survival compared to historical controls undergoing emergent Norwood. © 2006 Wiley‐Liss, Inc.
Transradial cardiac catheterization in patients with coronary bypass grafts: Feasibility analysis and comparison with transfemoral approach
Authors: Sanmartin Marcelo , Cuevas Diogenes , Moxica Joaquin , Valdes Manuel , Esparza Jose , Baz Jose Antonio , Mantilla Ramon , Iñiguez Andres
Published: March 2006

The objective of this study was to analyze the feasibility and safety of transradial catheterization in patients with remote surgical cardiac revascularization. Selective catheterization of coronary bypass grafts might be more difficult and time‐consuming from the radial artery as compared to the femoral route. This special patient subset has been either excluded or underrepresented in previous studies. Retrospective review was made of 304 cardiac diagnostic procedures performed from January 2001 through December 2004 in patients with coronary artery bypass grafts in a single center. Patients had to be considered eligible for both transradial and transfemoral approach to be included. Cases with double internal mammary or gastroepiploic grafts were excluded. Selection of the arterial access was individualized according to operator preferences. Among diagnostic cases, transradial access was attempted as first choice in 151 cases (left radial in 133) and transfemoral in 154. Total procedural time (41 ± 22 vs. 40 ± 23 min), fluoroscopy time (15 ± 10 vs. 18 ± 13 min), and dye volume (180 ± 64 vs. 192 ± 73 ml) were similar. Crossover rates were 4.0% in the transradial group and 1.3% in transfemoral (P = 0.28). Only two patients in transradial group needed transfemoral access because of failure to catheterize a bypass graft. Transradial angiography of coronary bypass grafts can be performed with similar success rates as compared with transfemoral procedures and without a significant time delay. © 2006 Wiley‐Liss, Inc.
Percutaneous coronary intervention of or through saphenous vein grafts or internal mammary arteries: The impact of stents, adjunctive pharmacology, and multicomponent distal protection
Authors: Morrison Douglass A. , Thai Hoang , Goldman Steven , Felix Edward , Hernandez Joseph
Published: March 2006

We hypothesized that the use of stents and aggressive adjunctive pharmacotherapies has been associated with lower rates of complicating myocardial infarction (MI) and improved long‐term outcomes compared to either previous balloon‐only percutaneous coronary intervention (PCI) or atheroablative intervention for lesions of or through saphenous vein grafts (SVGs) and/or internal mammary arteries (IMAs). PCI of SVG has been complicated by relatively high rates of procedural MI and less favorable long‐term outcomes than native vessel PCI, stimulating the development and application of an array of technologies. This study was based on retrospective review of stent‐era (1999–2004) 5‐year experience of a single center with 95 SVG procedures in 85 patients and 20 IMA procedures in 20 patients. These cases were compared with the previously published experience of one of the operators during the balloon‐only period and literature review of the application of multiple technologies to SVG intervention, as well as consideration of the reoperation alternative. There was one in‐hospital death each in the SVG cohort (1%) and in the IMA cohort (5%). There were SIX procedural MIs (6%), defined by total CK > normal, and 19 procedural MIs (20%) based on troponin‐I > 1.0. Follow‐up has been from 4 months to 5 years (average, 2.5 years), with 91% survival and one late CABG in the IMA group. SVG PCI with stents and adjunctive pharmacotherapies is associated with relatively low rates of procedural MI and favorable long‐term outcomes. Published 2006 Wiley‐Liss, Inc.
Underlying aortic pathology and clinical health status determine success of endovascular stent‐grafting for descending thoracic aortic disease
Authors: Baumgart Dietrich , Eggebrecht Holger , Herold Ulf , Kuehl Hilmar , Piotrowski Jarowit , Niebel Wolfgang , Jakob Heinz‐Guenter , Erbel Raimund
Published: March 2006

Despite advances in medical and surgical treatment, acute as well as chronic diseases of the thoracic aorta are still associated with a high mortality. For the descending thoracic aorta, endovascular stent‐graft placement competes with surgical therapy for clinical outcome. From July 1999 till December 2004, a total of 84 patients (64 ± 14 years) with aortic disease of the descending thoracic aorta were treated. Nine patients had acute (AAD) and 35 chronic aortic dissection (AD), 16 had thoracic aortic aneurysms (TAA), 21 had penetrating aortic ulcer (PAU), and 3 patients had traumatic dissection (trans). Initial clinical status was assessed using the American Society of Anesthesiologists (ASA) classification. Fifty‐three patients were in class 2, 16 in class 3, 8 in class 4, and 7 in class 5. Stent‐graft placement was performed in the cardiac catheterization laboratory with the patient under general anesthesia. Technical success was obtained in 81/84 patients (96%). Within 30 days, seven patients (8%) died, four of them due to aortic rupture. In 14 patients, additional stent‐grafts had to be implanted due to type I endovascular leakage (n = 5) or additional entry site adding up to a total of 107 implanted stent‐grafts. During a follow‐up period of 21 ± 18 months, 17 additional patients died (22%). In10 patients, death was disease‐ or procedure‐related (13%). This long‐term mortality depended on the underlying disease and was highest in the group with TAA (45%) followed by AAD (38%) and AD (18%). Patients in ASA class 4 and 5 had a significantly worse outcome. No aortic‐related death occurred among patients with PAU or traumatic transsections. Overall, there was only one transient neurological deficit. Endovascular stent‐graft placement has acceptable results in the treatment of patients with disease of the descending thoracic aorta. The outcome strongly depends on the underlying aortic pathology and the clinical health status of the patients. Randomized trials are necessary in order to establish the exact value of this new therapeutic option. © 2006 Wiley‐Liss, Inc.
Three‐year follow‐up after intracoronary beta‐radiation therapy for in‐stent restenosis
Authors: Iofina Ekaterina , Radke Peter , Schubert Daniela , Langenberg Roswitha , Blindt Rüdiger , Hanrath Peter , Hoffmann Rainer
Published: March 2006

Background: Most studies that proved intracoronary radiation therapy (IRT) to be highly effective to reduce recurrent restenosis after treatment of in‐stent restenosis (ISR) have looked at time periods up to 12 months. Whether the beneficial effect from radiation is sustained during long‐term follow‐up remains a concern. This study sought to evaluate the effectiveness of IRT using a β‐emitter during a 3‐year follow‐up period. Methods: One hundred twenty‐eight consecutive symptomatic patients (mean age, 63 ± 11 years) with 134 in‐stent restenotic lesions were treated for ISR with IRT (noncentred β‐emitter, Novoste; radiation dosis 21.1 ± 3.1 Gy). Six‐month angiographic follow‐up was obtained in 104 patients (81%) with 105 lesions (78%). All patients underwent 36‐month clinical follow‐up. Results: Six‐month angiographic restenosis rate was 22% in stent (29% in lesion) with an in‐stent late loss of 0.49 ± 0.62 mm. Target lesion resvascularization (TLR) at 6‐month follow‐up was performed in 23 cases (18%). MACE (death, myocardial infarction, and target vessel revascularisation) was observed in 24 patients (19%). At 36‐month follow‐up, TLR increased to 36 cases (28%) and MACE was observed in 47 patients (37%). In a multivariate analysis, minimal lumen diameter before treatment of ISR using IRT was the only predictor of recurrent TLR at 36 months (OR = 0.131; 95% CI, 0.068–0.254; p = 0.002). In a subgroup of patients (N = 15) without restenosis at 6‐month angiography but with clinically driven recurrent late angiography (mean, 18 ± 7 months); in‐lesion late loss increased from 0.47 ± 0.54 mm at 6 months to 1.27 ± 0.76 mm at repeated angiography (p = 0.005). Conclusion: There is a considerable number of delayed recurrent restenosis post IRT for ISR. This is due to ongoing late loss more than 6‐month post IRT. The minimal lumen diameter before IRT predicts the need for recurrent TLR at 36 months. © 2006 Wiley‐Liss, Inc.
Correlates and outcomes of retroperitoneal hemorrhage complicating percutaneous coronary intervention
Authors: Ellis Stephen G. , Bhatt Deepak , Kapadia Samir , Lee David , Yen Michael , Whitlow Patrick L.
Published: March 2006

BACKGROUND: Retroperitoneal hemorrhage (RPH) is an infrequent but occasionally fatal complication of percutaneous coronary intervention (PCI). Therefore, it has been studied in relatively small numbers of patients. METHODS: Prospectively collected data on 28,378 consecutive patients treated between 1992 and 2003 were examined, supplemented by a date‐based case control cohort study (76 RPH and 76 non‐RPH patients) to examine elements not routinely recorded prospectively. Independent correlates of RPH were determined using logistical regression analysis. RESULTS: One hundred sixty‐three patients (0.57%) developed RPH; of these 73.5% required blood transfusions and 10.4% expired during hospitalization (P < 0.001 for both compared with patients without RPH). RPH was independently associated with femoral artery sheath placement superior to the inferior epigastric artery (P < 0.001), female sex (P < 0.001), use of Angioseal™ Device (P < 0.001), glycoprotein IIb/IIIa inhibitor use (P = 0.001), and patient presentation with the acute myocardial infarction (P = 0.035), and was inversely related to patient weight (P = 0.014). Of the 17 patient deaths, 6 were directly related to RPH, 2 of which occurred in association with delays in resuscitation efforts consequent to attempts to obtain diagnostic confirmation with CT imaging. CONCLUSIONS: RPH remains an infrequent but serious complication of PCI. Appropriate management of the femoral access site and the patient once this complication is suspected may minimize adverse outcomes. © 2006 Wiley‐Liss, Inc.
Utilization of a pressure sensor guidewire to measure bileaflet mechanical valve gradients: Hemodynamic and echocardiographic sequelae
Authors: Doorey Andrew J. , Gakhal Mandip , Pasquale Michael J.
Published: March 2006

Suspected prosthetic valve dysfunction is a difficult clinical problem, because of the high risk of repeat valvular surgery. Echocardiographic measurements of prosthetic valvular dysfunction can be misleading, especially with bileaflet valves. Direct measurement of trans‐valvular gradients is problematic because of potentially serious catheter entrapment issues. We report a case in which a high‐fidelity pressure sensor angioplasty guidewire was used to cross prosthetic mitral and aortic valves in a patient, with hemodynamic and echocardiographic assessment. This technique was safe and effective, refuting the inaccurate non‐invasive tests that over‐estimated the aortic valvular gradient. © 2006 Wiley‐Liss, Inc.
Comparison of the effectiveness of sirolimus‐ and paclitaxel‐eluting stents for small coronary artery lesions
Authors: Park Kyoung‐Ha , Park Seong‐Wook , Hong Myeong‐Ki , Kim Young‐Hak , Lee Bong‐Ki , Park Duk‐Woo , Choi Bong‐Ryong , Kim Mi‐Jeong , Park Kyoung‐Min , Lee Cheol Whan , Cheong Sang‐Sig , Kim Jae‐Joong , Park Seung‐Jung
Published: March 2006

Background: The sirolimus‐eluting stent (SES) and the paclitaxel‐eluting stent (PES) reduce restenosis in small coronary artery lesions. However, it is not clear which of these stents is superior in terms of clinical outcomes. Methods: The authors retrospectively examined 197 patients with 245 de novo small coronary artery lesions (≤≤2.75 mm) that were treated with either the SES (156 lesions) or the PES (89 lesions). Six‐month angiographic restenosis rates and the 9‐month target lesion revascularization (TLR) rates were compared between the two groups. Results: In terms of baseline clinical and angiographic parameters, the two groups well matched together. Six‐month angiographic follow‐up was performed on 170 patients (86.3%), comprising 135 SES lesions (86.5%) and 76 PES lesions (85.4%). At 6‐month angiographic follow‐up, the late lumen loss was less in the SES group than in the PES group (0.29 ± 0.42 vs. 0.69 ± 0.63 mm, P < 0.01). Therefore, the SES group showed a lower rate of angiographic restenosis than the PES group (6.7% vs. 27.7%, P < 0.01). At 9 months there were no deaths or myocardial infarctions in either group. The 9‐month TLR rate was lower in the SES group than in the PES group (3.3% vs. 14.4%, P < 0.01). The Kaplan‐Meier estimate of freedom from TLR at 9 months was 96.7% for the SES patients and 86.5% for the PES patients (P < 0.01). Conclusions: The SES treatment may be superior to the PES treatment in terms of long‐term clinical and angiographic outcomes in patients with small coronary artery lesions. © 2006 Wiley‐Liss, Inc.
The Challenge of the So‐Called Electron Configurations of the Transition Metals
Authors: Wang S. G. , Qiu Y. X. , Fang H. , Schwarz W. H. E.
Published: March 2006

Quite different meanings are attached by chemists to the words element, atom, orbital, order of orbitals or configurations. This causes conceptual inconsistencies, in particular with respect to the transition‐metal elements and their atoms or ions. The different meanings will here be distinguished carefully. They are analyzed on the basis of empirical atomic spectral data and quasi‐relativistic density functional calculations. The latter are quite reliable for different average configuration energies of transition‐metal atoms. The so‐called “configurations of the chemical elements”, traditionally displayed in periodic tables, are the dominant configurations of the lowest spin‐orbit levels of the free atoms. They are chemically rather irrelevant. In many‐electron systems the ns and np AOs are significantly below the more hydrogen‐like nd ones. Even (n+1)s is below nd for all light neutral atoms from C onwards, but only up to the first elements of the respective long rows! The most common orbital order in transition‐metal atoms is 3p ≪ 3d < 4s etc. The chemically relevant configuration in group g is always dg instead of dg−2 s2. Conceptually clear reasoning eliminates apparent textbook inconsistencies between simple quantum‐chemical models and the empirical facts. The empirically and theoretically well‐founded Rydberg (n−δl) rule is to be preferred instead of the historical Madelung (n+l) rule with its large number of exceptions.
A New Triferrocenyl‐tris(hydroxymethyl)aminomethane Derivative as a Highly Sensitive Electrochemical Marker of Biomolecules: Application to the Labelling of PNA Monomers and Their Electrochemical Characterization
Authors: Baldoli Clara , Rigamonti Clara , Maiorana Stefano , Licandro Emanuela , Falciola Luigi , Mussini Patrizia Romana
Published: March 2006

We have designed and synthesised a new organometallic molecule containing three ferrocene groups for use as a highly sensitive electrochemical marker in biological assays. This trisferrocene derivative was conjugated to different PNA monomers, and the electrochemical activities of the conjugates were extensively investigated in organic solvents, in view of their potential diagnostic applications. The results showed that the introduction of a trisferrocene unit on the PNA monomer triples the current signal in comparison with the monoferrocene‐labelled one. Despite their greater molecular complexity, trisferrocene‐conjugated PNA monomers are even more electrochemically active than the reference ferrocene. By using differential pulse voltammetry (DPV), the detection limit can reach 10−8 M in acetonitrile solution. These results are a good premise for the use of the trisferrocene unit as an effective electrochemical probe for biomolecules.
Synthetic Approaches to Hydroazulenes and Guaianes through [4 + 3] Cycloadditions of Oxyallyl Intermediates
Authors: Föhlisch Baldur , Flogaus Robert , Henle Gerhard H. , Sendelbach Stefan , Henkel Sonja
Published: March 2006

Building blocks for syntheses of guaiane and secoguaiane sesquiterpenoids were prepared by the title reaction. 4‐(3‐Methylfuran‐2‐yl)butan‐2‐one (1) was obtained in five steps from methyl 3‐methylfuran‐2‐carboxylate (4), and treatment of 1 with pentachloroacetone and sodium 2,2,3,3‐tetrafluoropropoxide in 2,2,3,3‐tetrafluoropropan‐1‐ol produced a [4 + 3] cycloadduct that was dechlorinated without prior isolation to give the oxabicyclic diketone 2 in a low yield. A better route to diketone 2 was via the oxabicycle 10b, prepared in a high yield from 2‐(but‐3‐en‐1‐yl)‐3‐methylfuran (9) and pentachloroacetone, followed by dechlorination. Treatment of 2 with dilute methanolic potassium hydroxide resulted in the cleavage of the oxa bridge, with formation of 3,8‐dimethylazulen‐4‐ol (11). Catalytic hydrogenation of 2 afforded the saturated oxabicyclic diketone 14, intramolecular aldol condensation of which gave the tricycle 15. The oxa bridge of the oxatricyclic enone 15 was cleaved by hydrogenolysis in the presence of palladium/carbon catalyst to give the 6‐hydroxydecahydroazulen‐4‐one 16. Treatment of isobutyl trichloromethyl ketone (20) with furan 9 and sodium trifluoroethoxide in trifluoroethanol eventually gave the 2‐chlorooxabicycle 22. This solvolysis product was dechlorinated to furnish the oxabicyclic trifluoroethoxy ketone 24 as a single product that was subjected to the sequence of transformations used for 10b. X‐ray structure analysis of the resulting saturated diketone 26 established the endo configuration of the isopropyl group. Finally, aldol cyclization of 26 furnished the guaiane derivative 27. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)
Synthesis and Photophysical Properties of a Pyrazolino[60]fullerene with Dimethylaniline Connected by an Acetylene Linkage
Authors: Gouloumis Andreas , Oswald Frédéric , El‐Khouly Mohamed E. , Langa Fernando , Araki Yasuyuki , Ito Osamu
Published: March 2006

A new triad based on pyrazolino[60]fullerene and a conjugated dimethylaniline group has been synthesized by a copper‐free Sonogashira cross‐coupling reaction using microwave irradiation as the source of energy. The electrochemical and photophysical properties of the triad were systematically investigated by techniques such as time‐resolved fluorescence and transient absorption spectroscopy. Charge separation via the excited singlet state of the C60 moiety was confirmed in polar and nonpolar solvents and competes with triplet formation of the C60 moiety. The charge‐separated state persisted for 91 ns. Such long lifetimes are characteristic of long distances between the radical anion of the pyrazolino[60]fullerene derivative and the radical cation of the dimethylaniline moiety. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)
Macrocyclic Cyclo[n]malonates – Synthetic Aspects and Observation of Columnar Arrangements by X‐ray Crystallography
Authors: Chronakis Nikos , Brandmüller Torsten , Kovacs Christian , Reuther Uwe , Donaubauer Wolfgang , Hampel Frank , Fischer Felix , Diederich François , Hirsch Andreas
Published: March 2006

A variety of achiral and chiral macrocyclic oligomalonates were synthesised in a one‐step procedure through condensation of malonyl dichloride with α,ω‐diols. We have investigated the applicability of this method by varying the length and type of the spacers in the diol. Product distribution analysis revealed that the preferential formation of monomeric, dimeric, or trimeric macrocyclic malonates can be controlled by choosing diols with specific spacers connecting the hydroxy groups. Of special interest are the macrocyclic bismalonates, as they show pronounced crystallisability and arrange into columnar motifs in the solid state. They feature distinctive dihedral angles: all ester moieties adopt anti conformations whereas the planes of the carboxy moieties of each malonate residue arrange in an approximately orthogonal fashion. The latter geometry is enforced by the macrocyclic structures, as revealed by a conformational search in the Cambridge Structural Database. The X‐ray diffraction data show that C=O···H–C, and C–O···H–C hydrogen bonds stabilise the columnar arrangement of the dimeric rings with formation of tubular assemblies. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)
Synthesis of Amino‐L‐Lyxose Phosphonates as Fucosyl‐Phosphate Mimics
Authors: Chevrier Carine , Le Nouën Didier , Defoin Albert , Tarnus Céline
Published: March 2006

Some reactions of nitrone 4 are described, namely the nucleophilic addition of dialkyl phosphites, HOP(OR)2, 5a–c or of diethyl methylphosphonate 8 and the dipolar [2+3] cycloaddition of vinylphosphonate 11. Chemical transformations led to 4‐amino‐L‐fucose derivatives bearing a phosphonate group in the 1α position linked to the pyrrolidine ring through a chain of 0–2 carbon atoms. The target compounds proved to be good‐to‐excellent α‐L‐fucosidase inhibitors. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)
Metalated 1‐(p‐Methoxybenzyl)pyrazole: A Structural Chameleon
Authors: Ondi Levente , Schlosser Manfred
Published: March 2006

When treated with either butyllithium or lithium diisopropylamide, 1‐(p‐methoxybenzyl)pyrazole undergoes metalation at the exocyclic α‐position but mutates to the 5‐lithio species in the course of few minutes or hours. Trapping the intermediates with a rapidly reacting electrophile such as chlorotrimethysilane or carbon dioxide offers selective access to either of the two possible regioisomers. On the other hand, the relatively inert 1‐iodobutane and butyl trifluoromethanesulfonate (“triflate”) inevitably give rise to product mixtures, as the 5‐lithio species is more slowly intercepted than it can revert to the α‐metallomer by a rapid, though intermolecular, dynamic equilibration process. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)
Celebrating the 75th Birthday of Professor Bertold J. Radola
Authors: Boček Petr
Published: March 2006

No abstracts.
ELECTROPHORESIS: Miles Gloriosus?
Authors: Righetti Pier Giorgio
Published: March 2006

No abstracts.
Top‐down influences on lexical selection during spoken word production: A 4T fMRI investigation of refractory effects in picture naming
Authors: de Zubicaray Greig , McMahon Katie , Eastburn Mathew , Pringle Alan
Published: March 2006

Spoken word production is assumed to involve stages of processing in which activation spreads through layers of units comprising lexical‐conceptual knowledge and their corresponding phonological word forms. Using high‐field (4T) functional magnetic resonance imaging (fMRI), we assessed whether the relationship between these stages is strictly serial or involves cascaded‐interactive processing, and whether central (decision/control) processing mechanisms are involved in lexical selection. Participants performed the competitor priming paradigm in which distractor words, named from a definition and semantically related to a subsequently presented target picture, slow picture‐naming latency compared to that with unrelated words. The paradigm intersperses two trials between the definition and the picture to be named, temporally separating activation in the word perception and production networks. Priming semantic competitors of target picture names significantly increased activation in the left posterior temporal cortex, and to a lesser extent the left middle temporal cortex, consistent with the predictions of cascaded‐interactive models of lexical access. In addition, extensive activation was detected in the anterior cingulate and pars orbitalis of the inferior frontal gyrus. The findings indicate that lexical selection during competitor priming is biased by top‐down mechanisms to reverse associations between primed distractor words and target pictures to select words that meet the current goal of speech. Hum Brain Mapp, 2006. © 2006 Wiley‐Liss, Inc.