bluuebunny/crossref_metadata_2025 huggingface dataset:
1,1‐allylboration of bis(silyl)ethynes: electron‐deficient SiHB bridges and novel heterocycles via intramolecular hydrosilylation
Authors: Wrackmeyer Bernd , Tok Oleg L. , Bubnov Yuri N.
Published: December 2003

The reaction of bis(silyl)ethynes 2–4, bearing one, two and three hydrides at one of the silicon atoms, with triallylborane 1 leads primarily to alkenes 5, 8 and 11 respectively by 1,1‐allylboration. In these alkenes, the diallylboryl and the silyl group bearing one or more SiH functions are in cis‐positions at the CC bond, giving rise to the formation of an electron‐deficient SiHB bridge. This follows unambiguously from the consistent set of NMR data, in particular from the observation of isotope‐induced chemical shifts 2Δ10/11B(29Si). The activation of the SiH bond in 5, 8 and 11 induces intramolecular hydrosilylation under very mild reaction conditions to give 1,4‐silabora‐cyclo‐2‐heptenes 7, 10 and 13 respectively. Upon heating, these seven‐membered heterocycles undergo ring contraction by 1,1‐deallylboration to give the 1‐sila‐cyclo‐2‐hexenes 14–16, and bear an exocyclic diallylboryl group in 3‐position. All proposed structures are based on consistent 1H, 11B, 13C and 29SiNMR data. Copyright © 2004 John Wiley & Sons, Ltd.
Smooth muscle stem cells
Authors: Hirschi Karen K. , Majesky Mark W.
Published: December 2003

Vascular smooth muscle cells (SMCs) originate from multiple types of progenitor cells. In the embryo, the most well studied SMC progenitor is the cardiac neural crest stem cell. Smooth muscle differentiation in the neural crest lineage is controlled by a combination of cell intrinsic factors, including Pax3, Tbx1, FoxC1, and serum response factor, interacting with various extrinsic factors in the local environment such as bone morphogenetic proteins (BMPs), Wnts, endothelin (ET)‐1, and FGF8. Additional sources of multipotential cells that give rise to vascular SMCs in the embryo include proepicardial cells and possibly endothelial progenitor cells. In the adult, vascular SMCs must continually repair arterial injuries and maintain functional mass in response to changing demands upon the vessel wall. Recent evidence suggests that this is accomplished, in part, by recruiting multipotential vascular progenitors from bone marrow‐derived stem cells as well as from less well defined sources within adult tissues themselves. This article will review our current understanding of the origins of vascular SMCs from multipotential stem and progenitor cells in developing as well as adult vasculature. Anat Rec Part A 276A:22–33, 2004. © 2004 Wiley‐Liss, Inc.
The epicardium and epicardially derived cells (EPDCs) as cardiac stem cells
Authors: Wessels A. , Pérez‐Pomares J.M.
Published: December 2003

After its initial formation the epicardium forms the outermost cell layer of the heart. As a result of an epithelial‐to‐mesenchymal transformation (EMT) individual cells delaminate from this primitive epicardial epithelium and migrate into the subepicardial space (Pérez‐Pomares et al., Dev Dyn 1997; 210:96–105; Histochem J 1998a;30:627–634). Several studies have demonstrated that these epicardially derived cells (EPDCs) subsequently invade myocardial and valvuloseptal tissues (Mikawa and Fischman, Proc Natl Acad Sci USA 1992;89:9504–9508; Mikawa and Gourdie, Dev Biol 1996;174:221–232; Dettman et al., Dev Biol 1998;193:169–181; Gittenberger de Groot et al., Circ Res 1998;82:1043–1052; Manner, Anat Rec 1999;255:212–226; Pérez‐Pomares et al., Dev. Biol. 2002b;247:307–326). A subset of EPDCs continue to differentiate in a variety of different cell types (including coronary endothelium, coronary smooth muscle cells (CoSMCs), interstitial fibroblasts, and atrioventricular cushion mesenchymal cells), whereas other EPDCs remain in a more or less undifferentiated state. Based on its specific characteristics, we consider the EPDC as the ultimate ‘cardiac stem cell’. In this review we briefly summarize what is known about events that relate to EPDC development and differentiation while at the same time identifying some of the directions where EPDC‐related research might lead us in the near future. Anat Rec Part A 276A:43–57, 2004. © 2004 Wiley‐Liss, Inc.
Stem cells and the formation of the myocardium in the vertebrate embryo
Authors: Eisenberg Leonard M. , Kubalak Steven W. , Eisenberg Carol A.
Published: December 2003

A major goal in cardiovascular biology is to repair diseased or damaged hearts with newly generated myocardial tissue. Stem cells offer a potential source of replacement myocytes for restoring cardiac function. Yet little is known about the nature of the cells that are able to generate myocardium and the conditions they require to form heart tissue. A source of information that may be pertinent to addressing these issues is the study of how the myocardium arises from progenitor cells in the early vertebrate embryo. Accordingly, this review will examine the initial events of cardiac developmental biology for insights into the identity and characteristics of the stem cells that can be used to generate myocardial tissue for therapeutic purposes. Anat Rec Part A 276A:2–12, 2004. © 2004 Wiley‐Liss, Inc.
Hemangioblasts, angioblasts, and adult endothelial cell progenitors
Authors: Schatteman Gina C. , Awad Ola
Published: December 2003

After decades of speculation, proof of embryonic hemangioblasts finally emerged a few years ago. Surprisingly, at about the same time, evidence for adult hemangioblasts began to appear, and recent single‐cell bone marrow transplants have confirmed their existence. Embryonic and adult hemangioblasts appear to share antigenic determinants, including CD34, ACC133, and VEGFR2, although their phenotype may be plastic. They also respond to similar factors, prominent among them vascular endothelial growth factor (VEGF). In the adult, hemangioblasts reside principally in the bone marrow, although they may subsequently leave that niche to reside in nonhematopoietic tissues. A number of studies indicate that these cells or their progeny may be a significant source of endothelial cells in adult pathologic and nonpathologic vascularization, and may participate in vascular repair. In addition to hemangioblasts, a more differentiated source of endothelial cell progenitors may be present in the blood, namely, monocytes or monocytic‐like cells. The relative importance of the two cell types in vivo is not clear, though endothelial cells derived from the two sources may not be identical, and hemangioblasts seem to provide a stimulus for differentiation of the monocytes. Treatment with exogenous bone marrow‐derived cells can promote neovascularization, accelerate restoration of blood flow to ischemic tissues, and improve cardiac function after infarct. Hence, there is great hope that either alone, in combination with angiogenic factors, or as gene therapy vectors, we can harness these cells to treat ischemic and vascular diseases in the relatively near future. Anat Rec Part A 276A:13–21, 2004. © 2004 Wiley‐Liss, Inc.
Cardiac neural crest stem cells
Authors: Sieber‐Blum Maya
Published: December 2003

Whereas the heart itself is of mesodermal origin, components of the cardiac outflow tract are formed by the neural crest, an ectodermal derivative that gives rise to the peripheral nervous system, endocrine cells, melanocytes of the skin and internal organs, and connective tissue, bone, and cartilage of the face and ventral neck, among other tissues. Cardiac neural crest cells participate in the septation of the cardiac outflow tract into aorta and pulmonary artery. The migratory cardiac neural crest consists of stem cells, fate‐restricted cells, and cells that are committed to the smooth muscle cell lineage. During their migration within the posterior branchial arches, the developmental potentials of pluripotent neural crest cells become restricted. Conversely, neural crest stem cells persist at many locations, including in the cardiac outflow tract. Many aspects of neural crest cell differentiation are driven by growth factor action. Neurotrophin‐3 (NT‐3) and its preferred receptor, TrkC, play important roles not only in nervous system development and function, but also in cardiac development as deletion of these genes causes outflow tract malformations. In vitro clonal analysis has shown a premature commitment of cardiac neural crest stem cells in TrkC null mice and a perturbed morphology of the endothelial tube. Norepinephrine transporter (NET) function promotes the differentiation of neural crest stem cells into noradrenergic neurons. Surprisingly, many diverse nonneuronal embryonic tissues, in particular in the cardiovascular system, express NET also. It will be of interest to determine whether norepinephrine transport plays a role also in cardiovascular development. Anat Rec Part A 276A:34–42, 2004. © 2004 Wiley‐Liss, Inc.
Blood cell progenitors: Insights into the properties of stem cells
Authors: Yoder Mervin C.
Published: December 2003

Hematopoiesis is a dynamic process in which eight lineages of mature blood cells are derived from a common stem cell. Great progress has been made in identifying the functionally disparate progenitors that emerge from the stem cell and in elucidating the molecules required for their growth and survival. Further work will be required to understand the molecular mechanisms that regulate commitment of stem and progenitor cells to each stage of progenitor cell development and ultimately into the mature blood cells. Anat Rec Part A 276A:66–74, 2004. © 2004 Wiley‐Liss, Inc.
Adult stem cells
Authors: Young Henry E. , Black Asa C.
Published: December 2003

Development of a multicellular organism is accomplished through a series of events that are preprogrammed in the genome. These events encompass cellular proliferation, lineage commitment, lineage progression, lineage expression, cellular inhibition, and regulated apoptosis. The sequential progression of cells through these events results in the formation of the differentiated cells, tissues, and organs that constitute an individual. Although most cells progress through this sequence during development, a few cells leave the developmental continuum to become reserve precursor cells. The reserve precursor cells are involved in the continual maintenance and repair of the tissues and organs throughout the life span of the individual. Until recently it was generally assumed that the precursor cells in postnatal individuals were limited to lineage‐committed progenitor cells specific for various tissues. However, studies by Young, his colleagues, and others have demonstrated the presence of two categories of precursor cells that reside within the organs and tissues of postnatal animals. These two categories of precursor cells are lineage‐committed (multipotent, tripotent, bipotent, and unipotent) progenitor cells and lineage‐uncommitted pluripotent (epiblastic‐like, ectodermal, mesodermal, and endodermal) stem cells. These reserve precursor cells provide for the continual maintenance and repair of the organism after birth. Anat Rec Part A 276A:75–102, 2004. © 2004 Wiley‐Liss, Inc.
Cardiovascular potential of embryonic stem cells
Authors: Gerecht‐Nir Sharon , Fishman Bettina , Itskovitz‐Eldor Joseph
Published: December 2003

Initial events involved in the process of heart formation consist of myocardial differentiation as well as development of endothelial and endocardial tissues. As only limited means are allocated to the studying of cardiovascular system development, embryonic stem cells (ESCs) isolated from the inner cell mass (ICM) of developing mice or human blastocysts offer the first step toward the understanding of these complex and intriguing events. ESCs are able to differentiate into a wide range of cell types, including various vascular cells and cardiomyocytes, and their self‐renewal capability renders them a unique, homogeneous, and unlimited preliminary population of cells for the investigation of early developmental events of cardiovascular system and lineage commitment. This review summarizes the accumulated knowledge of the cellular and molecular mechanisms involved in the development of the cardiovascular system. Anat Rec Part A 276A:58–65, 2004. © 2004 Wiley‐Liss, Inc.
Adult stem cells and their cardiac potential
Authors: Eisenberg Leonard M. , Eisenberg Carol A.
Published: December 2003

Adult cardiac muscle is unable to repair itself following severe disease or injury. Because of this fundamental property of the myocardium, it was long believed that the adult myocardium is a postmitotic tissue. Yet, recent studies have indicated that new cardiac myocytes are generated throughout the life span of an adult and that extracardiac cells can contribute to the renewal of individual cells within the myocardium. In addition, investigations of the phenotypic capacity of adult stem cells have suggested that their potential is not solely restricted to the differentiated cell phenotypes of the source tissue. These observations have great implications for cardiac biology, as stem cells obtained from the bone marrow and other readily accessible adult tissues may serve as a source of replacement cardiac myocytes. In this review, we describe the evidence for these new findings and discuss their implications in context of the continuing controversy over stem cell plasticity. Anat Rec Part A 276A:103–112, 2004. © 2004 Wiley‐Liss, Inc.
Millimeter wave exposure reverses TPA suppression of gap junction intercellular communication in HaCaT human keratinocytes
Authors: Chen Q. , Zeng Q.L. , Lu D.Q. , Chiang H.
Published: December 2003

The effect of 30.16 GHz millimeter wave (MMW) exposure at 1.0 and 3.5 mW/cm2 on gap junction intercellular communication (GJIC) was studied in cultured HaCaT keratinocytes, using the fluorescence recovery after photobleaching (FRAP) technique and laser confocal scanning microscopy to follow the intracellular movement of 5,6‐carboxyfluorescein diacetate dye. While MMW exposure alone for 1 h at either 1.0 or 3.5 mW/cm2 did not affect GJIC, MMW exposure in combination with 5 ng/ml TPA treatment reversed TPA induced suppression of GJIC. Exposure at 1.0 mW/cm2 resulted in a partial reversal, and exposure at 3.5 mW/cm2 resulted in essentially full reversal of the TPA suppression. Bioelectromagnetics 25:1–4, 2004. © 2003 Wiley‐Liss, Inc.
Absence of genotoxicity in human blood cells exposed to 50 Hz magnetic fields as assessed by comet assay, chromosome aberration, micronucleus, and sister chromatid exchange analyses
Authors: Stronati L. , Testa A. , Villani P. , Marino C. , Lovisolo G.A. , Conti D. , Russo F. , Fresegna A.M. , Cordelli Eugenia
Published: December 2003

In the past, epidemiological studies indicated a possible correlation between the exposure to ELF fields and cancer. Public concern over possible hazards associated with exposure to extremely low frequency magnetic fields (ELFMFs) stimulated an increased scientific research effort. More recent research and laboratory studies, however, have not been able to definitively confirm the correlation suggested by epidemiological studies. The aim of this study was to evaluate the effects of 50 Hz magnetic fields in human blood cells exposed in vitro, using several methodological approaches for the detection of genotoxicity. Whole blood samples obtained from five donors were exposed for 2 h to 50 Hz, 1 mT uniform magnetic field generated by a Helmholtz coil system. Comet assay, sister chromatid exchanges (SCE), chromosome aberrations (CA), and micronucleus (MN) tests were used to assess DNA damage, one hallmark of malignant cell transformation. The effects of a combined exposure with X‐rays were also evaluated. Results obtained do not show any significant difference between ELFMFs exposed and unexposed samples. Moreover, no synergistic effect with ionizing radiation has been observed. A slight but significant decrease of cell proliferation was evident in ELFMFs treated samples and samples subjected to the combined exposure. Bioelectromagnetics 25:41–48, 2004. © 2003 Wiley‐Liss, Inc.
Effects of electromagnetic field emitted by cellular phones on the EEG during an auditory memory task: A double blind replication study
Authors: Krause Christina M. , Haarala Christian , Sillanmäki Lauri , Koivisto Mika , Alanko Katarina , Revonsuo Antti , Laine Matti , Hämäläinen Heikki
Published: December 2003

The effects of electromagnetic fields (EMF) emitted by cellular phones on the event related desynchronization/synchronization (ERD/ERS) of the 4–6, 6–8, 8–10, and 10–12 Hz electroencephalogram (EEG) frequency bands were studied in 24 normal subjects performing an auditory memory task. This study was a systematic replication of our previous work. In the present double blind study, all subjects performed the memory task both with and without exposure to a digital 902 MHz field in a counterbalanced order. We were not able to replicate the findings from our earlier study. All eight of the significant changes in our earlier study were not significant in the present double blind replication. Also, the effect of EMF on the number of incorrect answers in the memory task was inconsistent. We previously reported no significant effect of EMF exposure on the number of incorrect answers in the memory task, but a significant increase in errors was observed in the present study. We conclude that EMF effects on the EEG and on the performance on memory tasks may be variable and not easily replicable for unknown reasons. Bioelectromagnetics 25:33–40, 2004. © 2003 Wiley‐Liss, Inc.
Dosimetric analysis of the carousel setup for the exposure of rats at 1.62 GHz
Authors: Schönborn Frank , Poković Katja , Kuster Niels
Published: December 2003

The so‐called carousel setup has been widely utilized for testing the hypotheses of adverse health effects on the central nervous system (CNS) due to mobile phone exposures in the frequency bands 800–900 MHz. The objectives of this article were to analyze the suitability of the setup for the upper mobile frequency range, i.e., 1.4–2 GHz, and to conduct a detailed experimental and numerical dosimetry for the setup at the IRIDIUM frequency band of 1.62 GHz. The setup consists of a plastic base on which ten rats, restrained in radially positioned tubes, are exposed to the electromagnetic field emanating from a sleeved dipole antenna at the center. Latest generation miniaturized dosimetric E field and temperature probes were used to measure the specific absorption rate (SAR) inside the brain of three rat cadavers of the Lewis strain and two rat cadavers of the Fisher 344 strain. A numerical analysis was conducted on the basis of three numerical rat phantoms with voxel sizes between 1.5 and 0.125 mm3 that are based on high resolution MRI scans of a 300 g male Wistar rat and a 370 g male Sprague–Dawley rat. The average of the assessed SAR values in the brain was 2.8 mW/g per W antenna input power for adult rats with masses between 220 and 350 g and 5.3 mW/g per W antenna input power for a juvenile rat with a mass of 95 g. The strong increase of the SAR in the brain with decreasing animal size was verified by simulations of the absorption in numerical phantoms scaled to sizes between 100 and 500 g with three different scaling methods. The study also demonstrated that current rat phantom models do not provide sufficient spatial resolution to perform absolute SAR assessment for the brain tissue. The variation of the SARbrainav due to changes in position was assessed to be in the range from +15% to −30%. A study on the dependence of the performance of the carousel setup on the frequency revealed that efficiency, defined as SARbrainav per W antenna input power, and the ratio between SARbrainav and SARbodyav are optimal in the mobile communications frequency range, i.e., 0.8–3 GHz. Bioelectromagnetics 25:16–26, 2004. © 2003 Wiley‐Liss, Inc.
The pleiotropic actions of vitamin D
Authors: Lin Roberto , White John H.
Published: December 2003

General knowledge of the role of vitamin D3 in human physiology has been shaped by its discovery as a preventive agent of nutritional rickets, a defect in bone development due to inadequate uptake of dietary calcium. Studies on the function of the hormonal form of vitamin D3, 1α,25‐dihydroxyvitamin D3, have been greatly accelerated by the molecular cloning and structural analysis of the vitamin D3 receptor, which is a ligand‐activated regulator of gene transcription. Molecular genetic techniques including genomics have helped reveal that 1α,25‐dihydroxyvitamin D3 can control more than calcium homeostasis. It has widespread effects on cellular differentiation and proliferation, and can modulate immune responsiveness, and central nervous system function. Moreover, accumulating epidemiological and molecular evidence suggests that 1α,25‐dihydroxyvitamin D3 acts as a chemopreventive agent against several malignancies including cancers of the prostate and colon. Here, we survey the most‐recent findings and discuss their implications for the potential therapeutic uses of vitamin D analogues. BioEssays 26:21–28, 2004. © 2003 Wiley Periodicals, Inc.
The role of insulin as an antithrombotic humoral factor
Authors: Chakraborty Kushal , Sinha Asru K.
Published: December 2003

Insulin is well known for its essential role in carbohydrate metabolism: insulin deficiency results in the development of diabetes mellitus. It has been known for many years that people with diabetes mellitus are predisposed to develop thrombotic diseases including myocardial infarction. It was thought that the thrombus formation was the consequence of impaired carbohydrate metabolism. In recent years, it has become apparent that insulin is capable of ameliorating several pathophysiological events, leading to the inhibition and dissolution of the formed thrombus in the system. These insulin‐induced events include inhibition of platelet aggregation by prompting the synthesis of NO in platelet and prostacyclin in endothelial cells. Furthermore, insulin upregulates prostacyclin receptors and downregulates α2 adrenergic receptor in platelets, thereby amplifying the inhibition of platelet aggregation. Insulin also releases tissue plasminogen activator, a potent thrombolytic enzyme, from the platelet membrane which dissolves the formed thrombus leading to the resumption of normal blood circulation. In effect, insulin could be an essential tool in the control of thrombotic disorders. BioEssays 26:91–98, 2004. © 2003 Wiley Periodicals, Inc.
Here is the evidence, now what is the hypothesis? The complementary roles of inductive and hypothesis‐driven science in the post‐genomic era
Authors: Kell Douglas B. , Oliver Stephen G.
Published: December 2003

It is considered in some quarters that hypothesis‐driven methods are the only valuable, reliable or significant means of scientific advance. Data‐driven or ‘inductive’ advances in scientific knowledge are then seen as marginal, irrelevant, insecure or wrong‐headed, while the development of technology—which is not of itself ‘hypothesis‐led’ (beyond the recognition that such tools might be of value)—must be seen as equally irrelevant to the hypothetico‐deductive scientific agenda. We argue here that data‐ and technology‐driven programmes are not alternatives to hypothesis‐led studies in scientific knowledge discovery but are complementary and iterative partners with them. Many fields are data‐rich but hypothesis‐poor. Here, computational methods of data analysis, which may be automated, provide the means of generating novel hypotheses, especially in the post‐genomic era. BioEssays 26:99–105, 2004. © 2003 Wiley Periodicals, Inc.
Got milk? A pheromonal message for newborn rabbits
Authors: Luo Minmin
Published: December 2003

A substance in rabbit milk, 2‐methylbut‐2‐enal (2MB2), has been identified as a pheromone that triggers stereotypical searching behavior from rabbit pups.1 Pups respond to the odor of 2MB2 solutions in concentration‐dependent manner, but fail to respond to 20 other volatile components in rabbit milk and 20 additional odorants. The effectiveness of 2MB2 generalizes across strains and breeds of rabbits, but is ineffective in closely related species. Finally, pup responsiveness to 2MB2 is innate and does not require learning. This study, for the first time, identifies a mammary pheromone that provides sufficient sensory cue for nipple attachment by newborns. In addition to contributing to our understanding of pheromonal communication, it provides an advantageous model system for neurobiologists. BioEssays 26:6–9, 2004. © 2003 Wiley Periodicals, Inc.
Comparison of transradial vs. transfemoral approach in the treatment of acute myocardial infarction with primary angioplasty and abciximab
Authors: Philippe Francois , Larrazet Fabrice , Meziane Tarek , Dibie Alain
Published: December 2003

Compared to the femoral approach, the use of radial arterial access has been demonstrated to reduce the incidence of access site bleeding complications in staged procedures. The purpose of this study was to evaluate clinical outcomes comparing radial and femoral approaches in the treatment of acute myocardial infarction with primary angioplasty and the GP IIb/IIIa inhibitor abciximab. Between 15 September 1999 and 15 September 2002, we prospectively enrolled 119 consecutive patients undergoing primary angioplasty with abciximab comparing radial (n = 64) and femoral (n = 55) access. In this nonrandomized study, freedom from major cardiac events at 1‐month follow‐up occurred in 62 (97%) and 52 (94.5%) patients in the radial and the femoral groups, respectively (P = 0.19). There were no major access site bleeding complications in the radial group, as opposed to three (5.5%) in the femoral group (P = 0.03), all requiring transfusions, with surgical repair necessary in two. Uncomplicated clinical course occurred in 62 (97%) of patients in the radial group and 49 (89%) in the femoral group (P = 0.04). Total hospital length of stay was significantly higher in the femoral group (5.9 ± 2.1 vs. 4.5 ± 1.2 days; P = 0.05). Cannulation time (from patient arrival at the catheterization laboratory to the effective placement of arterial sheath) and procedural time were not significantly different in the radial and the femoral group (respectively 8.5 ± 5.2 vs. 9.0 ± 5.8 min, P = 0.81, and 42 ± 28 vs. 44 ± 27 min, P = 0.74). Nevertheless, time of radiation (23.1 ± 11 vs. 16.5 ± 10.9 min; P = 0.01) and dose‐area product (28,616 ± 16,571 vs. 18,819 ± 10,739 R · cm2; P = 0.01) were significantly higher in the radial group. In patients with acute myocardial infarction treated with primary angioplasty and abciximab, the transradial access is efficacious with fewer major access site complications than transfemoral access. Transradial approach produces a shorter length of stay, as compared to the transfemoral approach, although with longer times of radiation and higher dose‐area product. Catheter Cardiovasc Interv 2004;61:67–73. © 2004 Wiley‐Liss, Inc.
Transcatheter treatment of a large traumatic ventricular septal defect
Authors: Cowley Collin G. , Shaddy Robert E.
Published: December 2003

We report the first successful transcatheter closure of a large traumatic ventricular septal defect in a 16‐year‐old adolescent. The risks of standard open heart repair using cardiopulmonary bypass were felt to be prohibitive due to coexistent injuries. This case demonstrates the feasibility of transcatheter therapy for traumatic ventricular septal defects. Catheter Cardiovasc Interv 2004;61:144–146. © 2004 Wiley‐Liss, Inc.
Transradial coronary angiography in patients with contraindications to the femoral approach: An analysis of 500 cases
Authors: Hildick‐Smith David J.R. , Walsh John T. , Lowe Martin D. , Shapiro Leonard M. , Petch Michael C.
Published: December 2003

The transradial approach to coronary angiography is considered by some to be a route of choice, by others to be a route that should be used only where there are relative contraindications to the femoral approach. We present the largest series to date of patients in whom transradial coronary angiography was undertaken specifically because of contraindications to the femoral approach. Since 1995, patients at this cardiothoracic center have been considered for a transradial approach to coronary angiography if there were relative contraindications to the femoral route. Data from 500 patients was prospectively collected. Patients were aged 66 ± 9 years; 72% were male. Indications for the radial approach included peripheral vascular disease (305), therapeutic anticoagulation (77), musculoskeletal (59), and morbid obesity (32). Sixty‐eight patients (14%) required a radial procedure following a failed femoral approach. Access was right radial 291 (58%), left radial 209 (42%). Eighteen operators were involved, but two operators undertook 355 (71%) of the cases. Catheter gauge was 6 Fr (n = 243; 49%), 5 Fr (219; 43%), and 4 Fr (29; 6%). The procedure was successful in 463 cases [92.6%; 88.2% for nonmajority vs. 94.4% (P < 0.05) for the two majority operators]. Success in males (93.6%) significantly exceeded that in females (90.1%; P < 0.05). In‐catheter‐laboratory duration was 45 ± 17 min; fluoroscopy time, 7.5 ± 6 min; radiation dose, 40 ± 23 CGy. The procedure was without incident in 408 cases (82%). There were procedural difficulties in 18% of cases, including radial artery spasm (12%) and vasovagal response (5%). The incidence was higher with 6 Fr catheters (23%) than with 5/4 Fr (15%; P < 0.05). Major procedural complications occurred in three cases: brachial artery dissection in one and cardiac arrest in two. Postprocedure major vascular complications numbered three: claudicant pain on handgrip in one, ischemic index finger (with subsequent terminal phalanx amputation due to osteomyelitis) in one, and ischemic hand for 4 hr in one. Patients with contraindications to the femoral approach form a high‐risk group. In these patients, transradial cardiac catheterization can be performed successfully and with a low risk of major complications. Minor adverse features remain frequent, occurring in one in five cases, though difficulties are minimized both with increasing operator experience and smaller sheath diameter. Catheter Cardiovasc Interv 2004;61:60–66. © 2004 Wiley‐Liss, Inc.
Vertebral artery stenting using distal emboli protection and transcranial Doppler
Authors: Mintz Edward P. , Gruberg Luis , Kouperberg Efim , Beyar Rafael
Published: December 2003

Recent studies have shown the feasibility and safety of the percutaneous approach for the treatment of vertebrobasilar disease using either balloon angioplasty alone, coronary stents, or combined angioplasty followed by stenting. The major concern in performing percutaneous procedures for the treatment of obstructive disease of the vertebrobasilar circulation involves the risk of embolic phenomena. We describe the successful treatment of a symptomatic patient with bilateral vertebrobasilar disease utilizing a distal protection filter during stenting with simultaneous use of transcranial Doppler to measure microembolization and vertebral artery blood flow during the procedure. Catheter Cardiovasc Interv 2004;61:12–15. © 2004 Wiley‐Liss, Inc.
Pulse transmission coefficient: A nonhyperemic index for physiologic assessment of procedural success following percutaneous coronary interventions
Authors: Brosh David , Higano Stuart T. , Kern Morton J. , Lennon Ryan J. , Holmes David R. , Lerman Amir
Published: December 2003

Intracoronary pressure measurements and the determination of fractional flow reserve (FFR) after percutaneous coronary intervention (PCI) predict adverse events. Coronary lesions may impair the transmission of pressure waves across a stenosis, potentially acting as a high‐frequency filter. The pulse transmission coefficient (PTC) is a nonhyperemic parameter that calculates the transmission of high‐frequency components of the pressure signal through a stenosis. It was shown recently that PTC is highly correlated with FFR. This study was designed to examine the change of PTC as compared to FFR following PCI. Pressure signals were obtained by pressure guidewire in 27 lesions pre‐ and post‐PCI and were analyzed with an algorithm that identifies the high‐frequency component in the pressure signal. The PTC was calculated at baseline as the ratio between distal and proximal high‐frequency components of the pressure waveform across the lesion. FFR measurements were assessed with intracoronary adenosine. There was a significant increase in PTC following PCI (0.15 ± 0.17 at baseline vs. 0.84 ± 0.11 post‐PCI; P < 0.001). Comparable changes were observed for FFR (0.58 ± 0.12 at baseline vs. 0.91 ± 0.05 post‐PCI; P < 0.001). PTC is a nonhyperemic parameter for physiologic assessment of coronary artery stenoses. Similar to FFR, PTC is significantly increased following PCI. Thus, it may serve as an adjunct index for the functional assessment of procedural success following PCI. Catheter Cardiovasc Interv 2004;61:95–102. © 2004 Wiley‐Liss, Inc.
Argatroban use during pediatric interventional cardiac catheterization
Authors: Cetta Frank , Graham Lynn C. , Wrona Laura L. , Arruda M. Janine , Walenga Jeanine M.
Published: December 2003

Argatroban is a synthetic direct thrombin inhibitor that does not interact with or induce heparin‐dependent antibodies. It is approved for use in adults for prevention and treatment of thrombosis associated with heparin‐induced thrombocytopenia (HIT). It has been administered safely in adults with HIT during coronary interventions. There are no reports of argatroban use for anticoagulation in pediatric patients. The present case describes the use of argatroban during coil embolization of a Fontan fenestration in a child with a history of HIT. The patient received a single bolus dose of 150 μg/kg of argatroban at the onset of the intervention. The fenestration was successfully occluded with a detachable coil. The activated clotting time (ACT) was > 200 sec throughout the procedure. The ACT returned to baseline 72 min after the bolus. No complications occurred. This case demonstrates the safe and successful use of argatroban during a transcatheter intervention in a pediatric patient with a history of HIT. The use of argatroban is promising for anticoagulation in children who require an alternative to heparin. Catheter Cardiovasc Interv 2004;61:147–149. © 2004 Wiley‐Liss, Inc.
Comparison of intracoronary vs. intravenous administration of abciximab in coronary stenting
Authors: Kakkar Aman K. , Moustapha Ali , Hanley Henry G. , Weiss Mitchell , Caldito Gloria , Misra Praphul , Reddy Pratap C. , Tandon Neeraj
Published: December 2003

There have been animal and human studies looking at intracoronary (IC) use of abciximab with good short‐term clinical outcomes. There exists no data comparing intracoronary with intravenous (IV) administration of abciximab beyond 30 days. We compared the clinical outcomes between the IC (n = 101) and IV (n = 72) group of patients. Patients who had coronary stenting and received abciximab were included in the study. All the patients received the standard systemic bolus dose of abciximab 0.25 mg/kg either via the IC or IV route, followed by a 12‐hr IV infusion at 0.125 μg/kg/min. The 6‐month composite endpoint of death or myocardial infarction was slightly higher in the IV (13.9%) than in the IC group (5.9%; P = 0.04). The frequency of bleeding complications was similar in both groups. The IC bolus route of abciximab may be superior to the intravenous route. Prospective randomized trials are warranted to validate these findings. Catheter Cardiovasc Interv 2004;61:31–34. © 2004 Wiley‐Liss, Inc.
Cutting balloon angioplasty of the popliteal and infrapopliteal vessels for symptomatic limb ischemia
Authors: Ansel Gary M. , Sample Nancy S. , Botti Charles F. , Tracy Amy J. , Silver Mitchell J. , Marshall Brian J. , George Barry S.
Published: December 2003

Options for lower limb percutaneous revascularization are limited especially for complex vessel obstruction. Cutting balloon angioplasty (CBA) has been described in the coronary literature as effective for complex disease. We analyzed our peripheral vascular database and report procedural outcomes along with the clinical success at a mean of 1‐year follow‐up in 73 patients with symptomatic lower limb ischemia undergoing CBA. CBA was successfully completed in all 73 patients (93 vessels; 100%) with predilation necessary in 4% of vessels. Severe intimal dissection or inadequate hemodynamic result necessitated in adjunctive stenting in 20%. There were no incidents of vessel perforation or surgical target vessel revascularization. One patient (1.5%) died during the periprocedural period due to renal failure. After mean follow‐up of 1 year (6–21 months), 89.5% of threatened limbs were salvaged. CBA is a safe and feasible option for the treatment of popliteal and infrapopliteal vessels. Catheter Cardiovasc Interv 2004;61:1–4. © 2004 Wiley‐Liss, Inc.
Anterior wall myocardial infarction in real world: Does reperfusion strategy make any differences?
Authors: Solodky Alejandro , Assali Abid R. , Behar Solomon , Boyko Valentina , Battler Alexander , Kornowski Ran
Published: December 2003

Some prospective randomized trials have established the superiority of primary percutaneous coronary intervention (PCI) over fibrinolytic treatment in patients with acute myocardial infarction (MI). These excellent PCI results are not duplicated in smaller hospitals where there may be delays in getting the cardiac catheterization team to the laboratory. This study aimed to compare the outcome of patients with anterior wall MI, without cardiogenic shock on admission, treated with primary PCI or thrombolytic therapy, in everyday practice. The data of all patients with MI hospitalized in all coronary care units operating in Israel during three consecutive national surveys was analyzed. A total of 1,038 patients with anterior wall MI were treated by reperfusion (886 received thrombolytic therapy, 152 primary PCI). Overall, the outcome of patients treated using primary PCI was better compared to patients treated with thrombolysis, with 68% relative risk reduction of 30‐day mortality (mortality at 30 days: 2% vs. 6.3%; P = 0.04). A subanalysis of patients according to age showed that the beneficial effect of primary PCI on mortality was mainly clustered among the younger. In our study, patients (especially younger than 75 years) with anterior wall MI allocated to primary PCI have a better clinical outcome. Catheter Cardiovasc Interv 2004;61:79–83. © 2004 Wiley‐Liss, Inc.
Predictors of vessel remodeling following directional coronary atherectomy
Authors: Kawamura Akio , Asakura Yasushi , Okabe Teruo , Yamane Akiko , Hui‐Chong Li , Ogawa Satoshi
Published: December 2003

The purpose of this study was to clarify predictors of vessel remodeling following directional coronary atherectomy (DCA). Negative remodeling after DCA leads to restenosis. However, little is known about the predictors of the vessel remodeling. Serial IVUS was performed in 43 lesions. The vessel remodeling was defined as adaptive if vessel area at follow‐up minus postprocedure vessel area was > 0 mm2, or as constrictive if < 0 mm2. Adaptive remodeling occurred in 21 (49%) lesions. Postprocedure percent plaque area was smaller in the adaptive group (32.9% ± 5.7% vs. 45.5% ± 8.8%; P < 0.005). At follow‐up, vessel area was larger in the adaptive group. However, plaque area was similar between the two groups. As a result, lumen area was larger in the adaptive group. Multivariate analyses showed that postprocedure percent plaque area < 40% was the only predictor of adaptive remodeling (odds ratio, 6.68; P < 0.05). Catheter Cardiovasc Interv 2004;61:44–51. © 2004 Wiley‐Liss, Inc.
Penetrating ulcer of ascending thoracic aorta in syphilis
Authors: Saleem Mohammad A. , McNeeley Marise , Zias Elias , Pucillo Anthony , Ro Jae H. , Weiss Melvin B.
Published: December 2003

Penetrating aortic ulcers (PAUs) are rare exotic pathological entities, classically located in the descending thoracic aorta. Their association with syphilis has never been reported. We describe a first case of a patient with cardiovascular syphilis presenting as PAU in the ascending aorta. Catheter Cardiovasc Interv 2004;61:16–19. © 2004 Wiley‐Liss, Inc.
Angiographic and hemodynamic predictors for successful outcome of transcatheter occlusion of patent ductus arteriosus in infants less than 8 kilograms
Authors: Forbes Thomas J. , Harahsheh Ashraf , Rodriguez‐Cruz Edwin , Morrow William R. , Thomas Ronald , Turner Daniel , Vincent Julie A.
Published: December 2003

Transcatheter occlusion of patent ductus arteriosus (PDA) using Gianturco coils (GCs) has been performed for the past decade. However, little has been written regarding anatomical and hemodynamic predictors for successful occlusion of the PDA in infants. This report is to evaluate the outcome of transcatheter occlusion of PDA in symptomatic infants less than 8 kg and to assess predictors of successful occlusion. Retrospective review of catheterization charts and cineangiograms of 42 symptomatic infants who underwent cardiac catheterization for attempted transcatheter occlusion of their PDA was conducted. The hemodynamic and angiographic data evaluated included the length/diameter (L/D) ratio, defined as the length divided by the narrowest diameter of the ductus arteriosus, and preocclusion pulmonary artery pressures. Thirty‐one out of 42 patients (74%) had successful occlusion. Twenty‐nine out of 42 infants had an L/D ratio > 3. Of these, 26 (90%) had successful occlusion of their PDA. Thirteen out of 42 patients had an L/D ratio ≤ 3. Of these, 8 (62%) had unsuccessful occlusion. Complications encountered were transient loss of femoral arterial pulse (n = 6), coil embolization (n = 5), hemolysis (n = 2), and mild left pulmonary artery obstruction (n = 2). No permanent loss of femoral arterial pulse was noted. These complications resulted in no mortality and minimal morbidity. The L/D ratio was the strongest predictor of successful outcome, with an L/D ratio greater than 3.0 being more amenable to transcatheter occlusion (odds ratio of 4.6). Other predictors for success included lower preocclusion systolic, diastolic, and mean pulmonary artery pressure and smaller ductal diameter. Our conclusion was that infants less than 8 kg with an L/D ratio > 3.0 can safely and successfully undergo transcatheter occlusion of their PDA using transcatheter coils. Catheter Cardiovasc Interv 2004;61:117–122. © 2004 Wiley‐Liss, Inc.
Antiphospholipid antibodies are common in patients referred for percutaneous patent foramen ovale closure
Authors: Dodge Stephen M. , Hassell Kathryn , Anderson C. Alan , Keller Jana , Groves Bertron , Carroll John D.
Published: December 2003

Very little is known about any interaction between patent foramen ovale (PFO) and various hypercoagulable disorders that have been associated with cryptogenic stroke. Percutaneous PFO closure for secondary prevention of paradoxical thromboembolization is receiving increasing attention. Hypercoagulability may affect the potential risks and expected benefits of percutaneous PFO closure. Consecutive patients undergoing percutaneous PFO closure at a single center were screened for the presence of antiphospholipid antibodies, elevated lipoprotein(a), hyperhomocysteinemia, and dysfibrinogenemia. Sixteen of 34 patients (47%) with complete arterial hypercoagulability screening had laboratory evidence of arterial hypercoagulability. Thirteen of these patients (38%) had antiphospholipid antibodies. Antiphospholipid antibodies appear to be common in patients referred for percutaneous PFO closure for secondary prevention of systemic thromboembolic events. Thorough testing based on established recommendations is warranted. Further studies are needed regarding the interaction between PFO and various hypercoagulable disorders that have been associated with cryptogenic stroke. Catheter Cardiovasc Interv 2004;61:123–127. © 2004 Wiley‐Liss, Inc.
Developing a framework for monitoring child poverty: results from a study in Uganda
Authors: Witter Sophie
Published: December 2003

In 2002 Save the Children UK carried out a study of child poverty in Uganda, as part of the on‐going Uganda Participatory Poverty Assessment Programme. Using participants from all regions of the country, the researchers asked children about their perceptions of poverty and anti‐poverty strategies, as well as questioning adult key informants about trends in child poverty, vulnerable groups and the effectiveness of government policies in tackling child poverty. This article reports on one aspect of the study, looking at the different indicators that children use to assess poverty, and comparing these with official poverty monitoring indicators. It finds that while some areas—notably, health, education and water and sanitation—are well documented, others, which may be as, or more significant to children's welfare, such as child abuse or quality of parental care, are almost totally neglected. A more holistic framework for assessing child poverty is proposed.
Participation or practice innovation: tensions in inter‐agency working to address disciplinary exclusion from school
Authors: Stead Joan , Lloyd Gwynedd , Kendrick Andrew
Published: December 2003

This paper explores dilemmas and tensions between two models of school based inter‐agency meetings to prevent disciplinary exclusion from school. The first model is characterised by innovative practice developed through long established professional relationships and addresses both individual and strategic issues in supporting young people who are at risk of disciplinary exclusion from school. The second model strongly emphasises the right to participation of young people and their families in school based inter‐agency meetings. Research participants in three Scottish councils (parents, pupils, teachers and other professionals1) had identified school based inter‐agency meetings as key to the process of inter‐agency working to prevent school exclusion.
Organisational competence: the study of a school council in action
Authors: Cotmore Richard
Published: December 2003

Despite the growth in the numbers of school councils, there has been little analytical and conceptual research about this form of participation. A case study of a school council in a junior school was adopted in this study. Complementary theories of ‘competent participation’ and ‘place in time and space’ contributed to the central organising concept: organisational competence. While highlighting structural constraints such as the boundaried nature of the council's work, this concept promotes a focus on councillors' agency and action which included their contribution to the council's distinctive process and position within the school system.
Hollow‐fiber assay for ligand‐mediated cell adhesion
Authors: Nordon Robert E. , Shu Alan , Camacho Fernando , Milthorpe Bruce K.
Published: December 2003

Background

The investigation of receptor‐ligand interactions in the cellular context presents significant technical challenges, first, to immobilize the ligand in a manner that preserves functional properties and, second, to relate ligand properties to cell adhesion and other cellular processes.

Methods

Ligand‐mediated cell adhesion was characterized by the development of a cellulose hollow‐fiber adhesion assay in which ligand (protein A) was immobilized onto the cellulose membrane as a recombinant fusion protein containing a cellulose‐binding domain affinity tag. Modules containing single cellulose hollow fibers were connected to a micro‐flow system for cell deposition and detachment with fluid shear stress. The cell adhesion process that occurred inside a segment of hollow fiber was observed in real time by using an inverted microscope equipped with a CCD camera and digital frame grabber. Image analysis software was developed to count cells and record digital images.

Results

Cell adhesion strength was characterized by counting the number of cells that were detached by application of fluid shear stress with values that ranged from 2.3 to 185 dyne/cm2. The median shear stress of detachment of KG1a cells was directly related to the duration of membrane contact and the amount of immobilized monoclonal antibody (anti‐CD34).

Conclusions

The hollow‐fiber assay provides a general method to determine functional properties of molecular domains that interact with cell surface receptors and markers. Cytometry Part A 57A:39–44, 2004. © 2003 Wiley‐Liss, Inc.