bluuebunny/crossref_metadata_2025_split huggingface dataset:
Regional myocardial perfusion during chronic biventricular pacing and after acute change of the pacing mode in patients with congestive heart failure and bundle branch block treated with an atrioventricular sequential biventricular pacemaker
Authors: Nielsen Jens Cosedis , Bøttcher Morten , Jensen Henrik Kjærulf , Nielsen Torsten Toftegaard , Pedersen Anders Kirstein , Mortensen Peter Thomas 
Published: March 2003

AbstractBackground:Biventricular (BiV) pacing has been found to improve systolic function and exercise tolerance in patients with severe congestive heart failure and bundle branch block. The mechanisms behind this beneficial effect is still not sufficiently clarified.Aim:To evaluate the regional myocardial perfusion (MP) during BiV pacing and after acute change of the pacing mode to conventional dual chamber (DDD) pacing, and single chamber atrial (AAI) pacing in patients with severe congestive heart failure and prolonged QRS width treated with chronic BiV pacing.Methods and Results:Fourteen patients (age 63±7 years, 13 male) were evaluated 13±7 months after implantation of a triple‐chamber biventricular pacemaker. MP was quantified with 13N‐labeled ammonia positron emission tomography during BiV pacing, DDD pacing, and AAI pacing. MP was assessed in the anterior, lateral, inferior, and septal regions, and the global mean MP was calculated. Clinical assessment was performed before pacemaker implantation and after at least 3 months of BiV pacing including a 6‐min walk test (WT), New York Heart Association (NYHA) class functional score and echocardiography. Global mean MP (BiV: 0.65±0.20 vs. DDD: 0.65±0.21 vs. AAI: 0.65±0.18 mlg−1min−1) and MP in each of the four regions did not differ between the three pacing modes. The patients improved clinically during BiV pacing; 6 min WT increased (338±59 vs. 415±73 m, P<0.001), NYHA class score improved (class I/II/III/IV: 0/0/11/3 vs. 1/9/2/0, P<0.001), and left ventricular ejection fraction increased (21±5 vs. 29±8%, P=0.004).Conclusion:No differences in regional MP are detectable after chronic BiV pacing when the pacing mode is changed acutely in patients with severe congestive heart failure and bundle branch block. This finding indicates, that the clinical improvement caused by BiV pacing is not associated with any increase in the MP and thereby oxygen demand.
TWO-DIMENSIONAL BIFURCATION DIAGRAMS: BACKGROUND PATTERN OF FUNDAMENTAL DC–DC CONVERTERS WITH PWM CONTROL
Authors: BENADERO L. , EL AROUDI A. , OLIVAR G. , TORIBIO E. , GÓMEZ E. 
Published: March 2003

One of the usual ways to build up mathematical models corresponding to a wide class of DC–DC converters is by means of piecewise linear differential equations. These models belong to a class of dynamical systems called Variable Structure Systems (VSS). From a classical design point of view, it is of interest to know the dynamical behavior of the system when some parameters are varied. Usually, Pulse Width Modulation (PWM) is adopted to control a DC–DC converter. When this kind of control is used, the resulting mathematical model is nonautonomous and periodic. In this case, the global Poincaré map (stroboscopic map) gives all the information about the system. The classical design in these electronic circuits is based on a stable periodic orbit which has some desired characteristics. In this paper, the main bifurcations which may undergo this orbit, when the parameters of the circuit change, are described. Moreover, it will be shown that in the three basic power electronic converters Buck, Boost and Buck–Boost, very similar scenarios are obtained. Also, some kinds of secondary bifurcations which are of interest for the global dynamical behavior are presented. From a dynamical systems point of view, VSS analyzed in this work present some kinds of bifurcations which are typical in nonsmooth systems and it is impossible to find them in smooth systems.
The Naturally Occurring Variant of Estrogen Receptor (ER) ERΔE7 Suppresses Estrogen-Dependent Transcriptional Activation by Both Wild-Type ERα and ERβ
Authors: García Pedrero Juana M. , Zuazua Pedro , Martínez-Campa Carlos , Lazo Pedro S. , Ramos Sofía 
Published: March 2003

AbstractWe have isolated and functionally characterized the exon 7-skipped variant (ERΔE7) of estrogen receptor (ER)α, which has emerged as the predominant variant expressed in multiple normal and tumoral tissues. However, to date no function has been established for this variant in mammalian cells. ERΔE7 exhibits a negligible ability to bind ligands, insensitivity to allosteric modulation by estrogen and antiestrogens, and loss of estrogen-dependent interaction with p160 coactivators such as SRC-1 and AIB1. ERΔE7 is able to form heterodimers with both ERα and ERβ in a ligand-independent manner. Transient expression experiments in HeLa cells show that increasing amounts of ERΔE7 result in a progressive inhibition of the estrogen-dependent transcriptional activation by both wild-type ERα and ERβ on estrogen response element-driven promoters. The inhibitory effect of ERΔE7 is due to the inhibition of binding of wild-type receptors to their responsive elements. Surprisingly, the activation function (AF)-1-dependent transactivation triggered by epithelial growth factor and phorbol-12-myristate-13-acetate is also abolished in ERΔE7 despite AF1 integrity, suggesting a cross-talk between AF1 and AF2 regions of the receptor. These results indicate that the naturally occurring variant ERΔE7 is a dominant negative receptor that, when expressed at high levels relative to wild-type ERs, might have profound effects on several estrogen-dependent functions.
Coenzyme Q Induces Nigral Mitochondrial Uncoupling and Prevents Dopamine Cell Loss in a Primate Model of Parkinson’s Disease
Authors: Horvath Tamas L. , Diano Sabrina , Leranth Csaba , Garcia-Segura Luis Miguel , Cowley Michael A. , Shanabrough Marya , Elsworth John D. , Sotonyi Peter , Roth Robert H. , Dietrich Edwin H. , Matthews Russel T. , Barnstable Colin J. , Redmond D. Eugene 
Published: March 2003

Abstract
Parkinson’s disease is characterized by dopamine cell loss of the substantia nigra. Parkinson’s disease and the neurotoxin 1-methyl-4-phenyl-1,2,5,6 tetrahydropyridine may destroy dopamine neurons through oxidative stress. Coenzyme Q is a cofactor of mitochondrial uncoupling proteins that enhances state-4 respiration and eliminate superoxides. Here we report that short-term oral administration of coenzyme Q induces nigral mitochondrial uncoupling and prevents dopamine cell loss after 1-methyl-4-phenyl-1,2,5,6 tetrahydropyridine administration in monkeys.
Hydroformylation of 1-Hexene over Rhodium Supported on Active Carbon Catalyst
Authors: Li Baitao , Li Xiaohong , Asami Kenji , Fujimoto Kaoru 
Published: March 2003

Abstract
Hydroformylation of 1-hexene on rhodium catalyst was studied under mild reaction conditions (P=3.0 MPa, CO/H2 = 1/1, T=403 K). Its hydroformylation performances were investigated in a variety of solvent. It was found that the excellent activity for the heterogeneous catalyst was showed in the n-octane solvent, while poor activity in the alcoholic and H2O solvent.
Prospective Study of Alcohol Consumption and Risk of Dementia in Older Adults
Authors: Mukamal Kenneth J. , Kuller Lewis H. , Fitzpatrick Annette L. , Longstreth W. T. , Mittleman Murray A. , Siscovick David S. 
Published: March 2003

ContextAlcohol consumption has been associated with complex changes in cerebral vasculature and structure in older adults. How alcohol consumption affects the incidence of dementia is less clear.ObjectiveTo determine the prospective relationship of alcohol consumption and risk of dementia among older adults.Design, Setting, and ParticipantsNested case-control study of 373 cases with incident dementia and 373 controls who were among 5888 adults aged 65 years and older who participated in the Cardiovascular Health Study, a prospective, population-based cohort study in 4 US communities. The controls were frequency-matched on age, death before 1999, and their attendance of a 1998-1999 clinic. Participants in this study underwent magnetic resonance imaging (MRI) of the brain and cognitive testing between 1992 and 1994 and were followed up until 1999.Main Outcome MeasuresOdds of incident dementia, ascertained by detailed neurological and neuropsychological examinations according to average alcohol consumption, assessed by self-reported intake of beer, wine, and liquor at 2 visits prior to the date of the MRI.ResultsCompared with abstention, the adjusted odds for dementia among those whose weekly alcohol consumption was less than 1 drink were 0.65 (95% confidence interval [CI], 0.41-1.02); 1 to 6 drinks, 0.46 (95% CI, 0.27-0.77); 7 to 13 drinks, 0.69 (95% CI, 0.37-1.31); and 14 or more drinks, 1.22 (95% CI, 0.60-2.49; P for quadratic term = .001). A trend toward greater odds of dementia associated with heavier alcohol consumption was most apparent among men and participants with an apolipoprotein E ϵ4 allele. We found generally similar relationships of alcohol use with Alzheimer disease and vascular dementia.ConclusionsCompared with abstention, consumption of 1 to 6 drinks weekly is associated with a lower risk of incident dementia among older adults.
Issues in the design of switched linear control systems: A benchmark study
Authors: Leith D.J. , Shorten R.N. , Leithead W.E. , Mason O. , Curran P. 
Published: March 2003

AbstractIn this paper we present a tutorial overview of some of the issues that arise in the design of switched linear control systems. A benchmark regulation problem is then presented. Copyright © 2003 John Wiley & Sons, Ltd.
Neutropenia and agranulocytosis in England and Wales: Incidence and risk factors
Authors: van Staa T.P. , Boulton F. , Cooper C. , Hagenbeek A. , Inskip H. , Leufkens H.G.M. 
Published: March 2003

AbstractThe objectives of this study were to estimate the incidence of idiosyncratic neutropenia and agranulocytosis in England and Wales and to evaluate their risk factors and outcomes. The study was conducted using data from the General Practice Research Database. All cases of idiosyncratic neutropenia or agranulocytosis were identified and the incidence was estimated. This was followed by a nested case‐control study, estimating odds ratios with drug exposure from conditional logistic regression. From 1987 to 1999, 3,224 patients with idiosyncratic neutropenia (50 with agranulocytosis) were identified. The incidences of neutropenia and agranulocytosis were estimated to be 120 and 7 cases per million people per year, respectively. The adjusted odds ratios for neutropenia were 34.7 (95% confidence interval 12.0–99.7) for current users of thyroid inhibitors, 9.5 (4.4–20.8) for users of disease‐modifying antirheumatic drugs, and 7.6 (4.9–11.9) for users of aminosalicylates. Other drugs with statistically significantly increased risks of neutropenia included antibacterial drugs, non‐opioid analgesics, NSAIDs, antidepressants, ulcer‐healing drugs, and anti‐epileptics. The increase in risk of neutropenia predominantly occurred during the first months of treatment. For most drugs investigated in this study, there was no relationship to daily dose. The excess 1‐year mortality was low among neutropenia and agranulocytosis cases and mostly explained by the underlying disease state. In conclusion, the highest risks of neutropenia were generally found in patients starting treatment. The excess 1‐year mortality was low among neutropenia and agranulocytosis cases and can be mostly explained by the underlying disease state. Am. J. Hematol. 72:248–254, 2003. © 2003 Wiley‐Liss, Inc.
Subcutaneous plasmacytomas with tropism to sites of previous trauma in a multiple myeloma patient treated with an autologous bone marrow transplant
Authors: Rosenblum Michael D. , Bredeson Christopher N. , Chang Chung‐Che , Rizzo J. Douglas 
Published: March 2003

AbstractWe report the case of a 59‐year‐old woman with Durie–Salmon stage IIIB IgGκ multiple myeloma (MM), who presented 83 days after autologous hematopoietic stem cell transplant (HSCT) with multiple subcutaneous plasmacytomas. These lesions were confined exclusively to sites where the patient had sustained local trauma. The patient had no pre‐transplant history of extramedullary disease and no evidence of plasma cells in the peripheral blood at any time throughout the course of her disease. This case represents the first report of refractory MM presenting as multiple subcutaneous plasmacytomas with specific tropism to sites of previous trauma. Selection of tumor cell subclones with unique chemokine receptor expression profiles that may explain this clinical observation is discussed. Am. J. Hematol. 72:274–277, 2003. © 2003 Wiley‐Liss, Inc.
Inhibition of cell surface mediated plasminogen activation by a monoclonal antibody against α‐Enolase
Authors: López‐Alemany Roser , Longstaff Colin , Hawley Stephen , Mirshahi Massoud , Fábregas Pere , Jardí Merce , Merton Elizabeth , Miles Lindsey A. , Félez Jordi 
Published: March 2003

AbstractLocalization of plasmin activity on leukocyte surfaces plays a critical role in fibrinolysis as well as in pathological and physiological processes in which cells must degrade the extracellular matrix in order to migrate. The binding of plasminogen to leukocytic cell lines induces a 30‐ to 80‐fold increase in the rate of plasminogen activation by tissue‐type (tPA) and urokinase‐type (uPA) plasminogen activators. In the present study we have examined the role of α‐enolase in plasminogen activation on the cell surface. We produced and characterized a monoclonal antibody (MAb) 11G1 against purified α‐enolase, which abrogated about 90% of cell‐dependent plasminogen activation by either uPA or tPA on leukocytoid cell lines of different lineages: B‐lymphocytic, T‐lymphocytic, granulocytic, and monocytic cells. In addition, MAb 11G1 also blocked enhancement of plasmin formation by peripheral blood neutrophils and monocytes. In contrast, MAb 11G1 did not affect plasmin generation in the presence of fibrin, indicating that this antibody did not interact with fibrinolytic components in the absence of cells. These data suggest that, although leukocytic cells display several molecules that bind plasminogen, α‐enolase is responsible for the majority of the promotion of plasminogen activation on the surfaces of leukocytic cells. Am. J. Hematol. 72:234–242, 2003. © 2003 Wiley‐Liss, Inc.
Partially successful treatment of a patient with chronic lymphocytic leukemia and Hodgkin's disease: Case report and literature review
Authors: Adiga Giridhar U. , Abebe Lool , Wiernik Peter H. 
Published: March 2003

AbstractChronic lymphocytic leukemia (CLL) is rarely associated with Hodgkin's disease (HD). We report a case of nodular sclerosis HD in a patient previously diagnosed with CLL. Reed‐Sternberg cells were CD15+ and CD30+. He was treated with dose‐escalated CHOP and at relapse, mitoxantrone, vinblastine, and CCNU (MVC) with partial response to the former and complete response to the latter, although the patient died 15 months later. Data from 88 other similar cases published in the English language were analyzed. Based on the histological and clinical features at the time of transformation, these patients were divided into distinct categories for analysis. Prognosis was found to be poorer in patients with continued active CLL when compared with those with CLL in remission at the time of transformation to HD. It is suggested that these two presentations may derive from different pathogenic mechanisms. Am. J. Hematol. 72:267–273, 2003. © 2003 Wiley‐Liss, Inc.
Pure red cell aplasia in a Sjögren's syndrome/lupus erythematosus overlap patient
Authors: Mavragani Clio P. , Vlachaki Eythymia , Voulgarelis Michalis 
Published: March 2003

AbstractHematological complications of systemic lupus erythematosus usually include anemia of chronic disease and peripheral destruction of blood cells. We describe the case of a young woman with Sjögren's syndrome'lupus erythematosus overlap, mother of infant with congenital heart block, complicated by pure red cell aplasia. The patient was asymptomatic until the onset of severe anemia. A serum inhibitor of erythropoiesis was detected before the onset of immunosuppression. Bone marrow examination showed a low CD4:CD8 ratio, an immune defect possibly linked with the unrestrained production of antibodies against erythroid progenitor cells. Am. J. Hematol. 72:259–262, 2003. © 2003 Wiley‐Liss, Inc.
Pallidal neuronal activity: Implications for models of dystonia
Authors: Hutchison William D. , Lang Anthony E. , Dostrovsky Jonathan O. , Lozano Andres M. 
Published: March 2003

AbstractDystonia is a neurological syndrome involving sustained contractions of opposing muscles leading to abnormal movements and postures. Recent studies report abnormally low pallidal neuronal activity in patients with generalized dystonia, suggesting hyperkinetic disorders result from underactive basal ganglia output. We examined this hypothesis in 11 patients with segmental and generalized dystonia undergoing microelectrode exploration of the internal globus pallidus (GPi) before pallidotomy or deep brain stimulation (DBS) implantation. The mean firing rates and firing patterns were compared with those in six patients with Parkinson's disease (PD). In seven patients who underwent surgery under local anesthesia, the mean GPi firing rate was 77Hz, similar to the 74Hz observed in the PD patients. However, in three dystonic patients under propofol anesthesia, GPi mean firing rate was much reduced (31Hz), and the firing pattern was distinguished by long pauses in activity, as reported by others. Low‐dose propofol in one other dystonia patient also seemed to suppress GPi firing. These results indicate that an abnormally low basal ganglia output is not the sine qua non of dystonia. The widely accepted pathophysiological models of dystonia that propose global decreases in basal ganglia output need to be viewed with caution in light of these findings. Ann Neurol 2003
Epilepsy after early‐life seizures can be independent of hippocampal injury
Authors: Raol Yogendra Sinh H. , Budreck Elaine C. , Brooks‐Kayal Amy R. 
Published: March 2003

AbstractProlonged early‐life seizures are considered potential risk factors for later epilepsy development, but mediators of this process remain largely unknown. Seizure‐induced structural damage in hippocampus, including cell loss and mossy fiber sprouting, is thought to contribute to the hyperexcitability characterizing epilepsy, but a causative role has not been established. To determine whether early‐life insults that lead to epilepsy result in similar structural changes, we subjected rat pups to lithium‐pilocarpine–induced status epilepticus during postnatal development (day 20) and examined them as adults for the occurrence of spontaneous seizures and alterations in hippocampal morphology. Sixty‐seven percent of rats developed spontaneous seizures after status epilepticus, yet only one third of these epileptic animals exhibited visible hippocampal cell loss or mossy fiber spouting in dentate gyrus. Most epileptic rats had no apparent structural alterations in the hippocampus detectable using standard light microscopy methods (profile counts and Timm's staining). These results suggest that hippocampal cell loss and mossy fiber sprouting can occur after early‐life status epilepticus but may not be necessary prerequisites for epileptogenesis in the developing brain. Ann Neurol 2003
An attention modulated response to disgust in human ventral anterior insula
Authors: Krolak‐Salmon Pierre , Hénaff Marie‐Anna , Isnard Jean , Tallon‐Baudry Catherine , Guénot Marc , Vighetto Alain , Bertrand Olivier , Mauguière François 
Published: March 2003

AbstractThe human brain is expert in analyzing rapidly and precisely facial features, especially emotional expressions representing a powerful communication vector. The involvement of insula in disgust recognition has been reported in behavioral and functional imaging studies. However, we do not know whether specific insular fields are involved in disgust processing nor what the processing time course is. Using depth electrodes implanted during presurgical evaluation of patients with drug‐refractory temporal lobe epilepsy, we recorded intracerebral event‐related potentials to human facial emotional expressions, that is, fear, disgust, happiness, surprise, and neutral expression. We studied evoked responses in 13 patients with insular contacts to specify the insular fields involved in disgust processing and assess the timing of their activation. We showed that specific potentials to disgust beginning 300 milliseconds after stimulus onset and lasting 200 milliseconds were evoked in the ventral anterior insula in four patients. The occurrence and latency of event‐related potentials to disgust in the ventral anterior insula were affected by selective attention. The analysis of spatial and temporal characteristics of insular responses to disgust facial expression lead us to underline the crucial role of ventral anterior insula in the categorization of facial emotional expressions, particularly the disgust. Ann Neurol 2003
Synthesis of novel C2‐symmetrical chiral sulfides and their utility in asymmetric epoxidation of aldehydes
Authors: Ishizaki Miyuki , Hoshino Osamu 
Published: March 2003

AbstractNovel C2‐symmetrical chiral sulfides were synthesized from (R,R)‐tartaric acid and their utility in the asymmetric epoxidation of aldehydes with benzyl bromide was examined. Among the sulfides used, silyl ether‐type sulfides were found to be superior to diol‐ and benzyl ether‐type sulfides. Also, the presence of an aromatic group on the sulfide was proven to be an important factor for increasing enantioselectivity. Chirality 15:300–305, 2003. © 2003 Wiley‐Liss, Inc.
A Facile Synthesis of a Push‐Pull Mixed‐Ligand Pd‐Dithiolene Complex Containing the Et2timdt Ligand (Et2timdt = Monoreduced Diethylimidazolidine‐2,4,5‐trithione)
Authors: Aragoni M. Carla , Arca Massimiliano , Denotti Carla , Devillanova Francesco A. , Grigiotti Emanuela , Isaia Francesco , Laschi Franco , Lippolis Vito , Pala Luca , Slawin Alexandra M. Z. , Zanello Piero , Woollins J. Derek 
Published: March 2003

AbstractThe reaction of the dithiolene [Pd(Et2timdt)2] (Et2timdt = formally monoreduced diethylimidazolidine‐2,4,5‐trithione) with Br2 or IBr yields the complex [Pd(Et2timdt)Br2], a good starting material for the synthesis of novel push‐pull mixed‐ligand Pd‐dithiolenes. The synthesis and characterisation of the unsymmetrical dithiolene [Pd(Et2timdt)(mnt)] (mnt = maleonitriledithiolato dianion) is also reported. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)