bluuebunny/crossref_metadata_2025_split huggingface dataset:
Estimation of relative cardiovascular pressures using time‐resolved three‐dimensional phase contrast MRI
Authors: Ebbers Tino , Wigström Lars , Bolger Ann F. , Engvall Jan , Karlsson Matts 
Published: September 2002

AbstractAccurate, easy‐to‐use, noninvasive cardiovascular pressure registration would be an important addition to the diagnostic armamentarium for assessment of cardiac function. A novel noninvasive and three‐dimensional (3D) technique for estimation of relative cardiovascular pressures is presented. The relative pressure is calculated using the Navier‐Stokes equations along user‐defined lines placed within a time‐resolved 3D phase contrast MRI dataset. The lines may be either straight or curved to follow an actual streamline. The technique is validated in an in vitro model and tested on in vivo cases of normal and abnormal transmitral pressure differences and intraaortic flow. The method supplements an intuitive visualization technique for cardiovascular flow, 3D particle trace visualization, with a quantifiable diagnostic parameter estimated from the same dataset. Magn Reson Med 45:872–879, 2001. © 2001 Wiley‐Liss, Inc.
A specific force deficit exists in skeletal muscle after partial denervation
Authors: Kalliainen Loree K. , Jejurikar Sameer S. , Liang Lawrence W. , Urbanchek Melanie G. , Kuzon William M. 
Published: September 2002

AbstractSkeletal muscle demonstrates a specific force deficit after repair of injured peripheral nerves, microneurovascular muscle transfer, and normal aging. Because atrophy cannot account for deficits in specific force, other, unknown, mechanisms are responsible for the resulting muscle contractile dysfunction under these circumstances. We tested the hypothesis that a subpopulation of denervated fibers is partially or completely responsible for the specific force deficit after partial denervation of the rat extensor digitorum longus muscle (EDL). Adult Fisher rats underwent either sham exposure or partial transection of 80% of the cross‐sectional area of the left deep peroneal nerve. After a 2‐week recovery period, maximum isometric force (F0) was measured in situ and maximum specific force (sF0) was calculated for EDL from both control (n = 8) and partial denervation (n = 7) groups. Innervated fiber cross‐sectional area (CSAinn) was measured directly from whole EDL cross sections after immunohistochemical labeling for neural cell adhesion molecule (NCAM), a marker of muscle fiber denervation. A corrected specific force value (sF0‐inn) was calculated by normalizing F0 to CSAinn. Partial skeletal muscle denervation resulted in significant reductions in muscle mass, F0, and sF0. The percentage of muscle fibers expressing NCAM in the extrajunctional sarcolemma increased from 1.0 ± 0.8% in control to 49 ± 15% in partially denervated EDL muscles. A 62.7% deficit in EDL specific force was observed after partial denervation. Denervated muscle fibers accounted for 59.3% of this deficit, but sF0‐inn still differed significantly between control and partially denervated muscles, with a 25.5% difference between groups. In partially denervated muscles, the specific force deficit is partially but not fully explained by a subpopulation of noncontractile, denervated fibers. © 2002 John Wiley & Sons, Inc. Muscle Nerve 25: 31–38 2002
Dipolar coupling and ordering effects observed in magnetic resonance spectra of skeletal muscle
Authors: Boesch Chris , Kreis Roland 
Published: September 2002

AbstractSkeletal muscle is a biological structure with a high degree of organization at different spatial levels. This order influences magnetic resonance (MR) in vivo—in particular 1H‐spectra—by a series of effects that have very distinct physical sources and biomedical applications: (a) bulk fat (extramyocellular lipids, EMCL) along fasciae forms macroscopic plates, changing the susceptibility within these structures compared to the spherical droplets that contain intra‐myocellular lipids (IMCL); this effect leads to a separation of the signals from EMCL and IMCL; (b) dipolar coupling effects due to anisotropic motional averaging have been shown for 1H‐resonances of creatine, taurine, and lactate; (c) aromatic protons of carnosine show orientation‐dependent effects that can be explained by dipolar coupling, chemical shift anisotropy or by relaxation anisotropy; (d) limited rotational freedom and/or compartmentation may explain differences of 1H‐MR‐visibility of the creatine/phosphocreatine resonances; (e) lactate 1H‐MR resonances are reported to reveal information on tissue compartmentation; (f) transverse relaxation of water and metabolites show multiple components, indicative of intra‐, extracellular and/or macromolecular‐bound pools, and in addition dipolar or J‐coupling lead to a modulation of the signal decay, hindering straightforward interpretation; (g) diffusion weighted 31P‐MRS has shown restricted diffusion of phosphocreatine; (h) magnetization transfer (MT) indicates that there is a motionally restricted proton pool in spin‐exchange with free creatine; reduced availability or restricted motion of creatine is particularly important for an estimation of ADP from 31P‐MR spectra, and in addition MT effects may alter the signal intensity of creatine 1H‐resonances following water‐suppression pulses; (i) transcytolemmal water‐exchange can be studied in 1H‐MRS by contrast‐agents applied to the extracellular space; (k) transport of glucose across the cell membrane has been studied in diabetes patients using a combination of 13C‐ and 31P‐MRS; and (l) residual quadrupolar interaction in 23Na MR spectra from human skeletal muscle suggest that sodium ions are bound to ordered muscular structures. Copyright © 2001 John Wiley & Sons, Ltd.
Abbreviations used:

ADC

apparent diffusion coefficient

BMS

bulk magnetic susceptibility

CK

creatine kinase

Cr

creatine

Cr/PCr

creatine and/or phosphocreatine

CSA

chemical shift anisotropy

EMCL

extramyocellular lipids

IMCL

intramyocellular lipids

MQF

multi‐quantum‐filtering

MRI

Magnetic resonance imaging

MRS

magnetic resonance spectroscopy

MT

magnetization transfer

PCr

phosphocreatine.
Common processing of in vivo MR spectra
Authors: in 't Zandt HJA , van der Graaf M , Heerschap A 
Published: September 2002

AbstractThis introductory article addresses approaches currently in use to process in vivo spectra. First, a brief overview is given of the information content represented by the parameters of MR signals. Subsequently, common steps in the processing of MR spectra such as pre‐processing, normalisation and quantification and the use of prior knowledge are described. Finally, some prospects for more advanced processing are given. Copyright © 2001 John Wiley & Sons, Ltd.
Calcium imaging of epileptiform events with single‐cell resolution
Authors: Badea Tudor , Goldberg Jesse , Mao Buqing , Yuste Rafael 
Published: September 2002

AbstractEpileptic discharges propagate through apparently normal circuits, although it is still unclear how this recruitment takes place. To understand the role of different classes of neurons in neocortical epilepsy, we have developed a novel imaging assay that detects which neurons participate in epileptiform discharges. Using calcium imaging of neuronal populations during bicuculline‐induced spontaneous epileptiform events in slices from juvenile mouse somatosensory cortex, we find that fast calcium transients correlate with epileptiform field potentials and intracellular depolarizing shifts and can be used as an optical signature that a given neuron has participated in an epileptiform event. Our results demonstrate a novel method to characterize epileptiform events with single‐cell resolution. In addition, our data are consistent with an important role for layer 5 in generating neocortical seizures and indicate that subgroups of neurons are particularly prone to epileptiform recruitment. © 2001 John Wiley & Sons, Inc. J Neurobiol 48: 215–227, 2001
NADPH‐diaphorase activity in the frontal cortex of NBM‐lesioned rats treated with verapamil
Authors: Caballero‐Bleda María , Redondo‐Aniorte Francisco Javier , Aldeguer‐Montiel Antonio , Popović Natalija , Popović Miroljub , Puelles Luis 
Published: September 2002

AbstractThe effect of the calcium antagonist verapamil on NADPH‐diaphorase activity was studied in the frontal cortex of rats with lesioned nucleus basalis magnocellularis (NBM). Treatment with verapamil (5 mg/kg/12h ip) started 24 h after NBM lesions and lasted 8 days. Animals were sacrificed on day 21 after NBM‐lesions. There were no significant differences between control, saline‐ and verapamil‐treated NBM‐lesioned rats in the total number of neurons expressing NADPH‐diaphorase. However, the number of neurons which show loss of enzymatic reaction in their processes was significantly higher in saline‐treated NBM‐lesioned rats. This may relate to incipient neurodegeneration in these neurons. The obtained reactive decrease of NADPH‐diaphorase staining was abolished by verapamil treatment, which suggests a significant neuroprotective effect of this calcium antagonist.
Calcium channel blocker flunarizine suppresses epileptiform activity induced by penicillin in rats
Authors: Bağirici Faruk , Gökçe Fatih M. , Demi̇r Şerif , Marangoz Cafer 
Published: September 2002

AbstractEpilepsy is a neurological disorder that affects approximately 1% of the world population. It is accepted that calcium influx into the cell is the first step of epileptic neuronal events. In the present study, the effects of flunarizine on epileptiform activity were investigated in an experimental epilepsy model induced by intracortical (i.c.) penicillin administration. The left cerebral cortex was exposed by craniotomy in anaesthetised rats. The epileptic focus was produced by injection of penicillin G potassium (500 units) into the somatomotor cortex. After epileptiform activity reached maximum frequency and amplitude, flunarizine was injected into the same area with a Hamilton microinjector. Before flunarizine administration, the average frequency of spikes was 18.7 ± 2.1/min and the average amplitude of the spikes was 1123 ± 85 μV. Microinjection of flunarizine (10, 100 μM) into the same area inhibited electrocorticogram epileptiform activity for 4‐5 minutes (p<0.001). Solvent alone did not affect epileptiform activity (p>0.05). The results of this study suggest that flunarizine may be an anticonvulsant agent for the treatment of epilepsy.
Dynamic optimization and Skiba sets in economic examples
Authors: Beyn Wolf‐Jürgen , Pampel Thorsten , Semmler Willi 
Published: September 2002

AbstractWe discuss two optimization problems from economics. The first is a model of optimal investment and the second is a model of resource management. In both cases the time horizon is infinite and the optimal control variables are continuous. Typically, in these optimal control problems multiple steady states and periodic orbits occur. This leads to multiple solutions of the state–costate system each of which relates to a locally optimal strategy but has its own limiting behaviour (stationary or periodic). Initial states that allow different optimal solutions with the same value of the objective function are called Skiba points. The set of Skiba points is of interest, because it provides thresholds for a global change of optimal strategies. We provide a systematic numerical method for calculating locally optimal solutions and Skiba points via boundary value problems. In parametric or higher dimensional systems Skiba curves (or manifolds) appear and we show how to follow them by a continuation process. We apply our method to the models above where Skiba sets consist of points or curves and where optimal solutions have different stationary or periodic asymptotic behaviour. Copyright © 2001 John Wiley & Sons, Ltd.
Challenges of managing local elections in transitional and developing countries: an illustrative essay
Authors: Hirschmann David 
Published: September 2002

AbstractThe purpose of this investigation into local elections in developing and transitional countries is to highlight typical challenges to the management of local elections, emphasizing the difficulties that appear to be peculiar to local as opposed to national elections; and help explain why they often turn out to be more difficult to manage than national elections, are of less interest to the public, and often less satisfactory in outcome. It gives attention first to differentiating between categories of subnational elections, and then deals with a number of problems faced in local elections. These are size, scale and complexity of managing such elections, lack of public interest, potential for local manipulation, challenges to fair or adequate media coverage and campaign finance arrangements. The article sets out to challenge simplification and optimism about local elections in developing and transitional societies. Copyright © 2001 John Wiley & Sons, Ltd.
African states, bureaucratic culture and computer fixes
Authors: Berman Bruce J. , Tettey Wisdom J. 
Published: September 2002

AbstractOur central argument in this article is that the introduction of computers in African states fails to produce the intended results. This is precisely because the trajectory of development of bureaucratic institutions in Africa has resulted in internal and external contexts that differ fundamentally from those of the Western states within which computing and information technology has been developed. This article explores the context in which computers were developed in Western industrialized societies to understand the circumstances that the technologies were designed to respond to and the bureaucratic culture that helped produce desired results. We then proceed to analyse the truncated nature of institution building in the colonial state, and how it structured the peculiar setting of the post‐colonial African state and dynamics surrounding the integration of the new information and communication technologies. We argue that the colonial state bequeathed to its post‐colonial successor three crucial characteristics that are of central importance to understanding why the introduction of computers does not produce anticipated improvements in public administration. These are the very limited technical capabilities of the bureaucracy; authoritarian decision‐making processes under the control of generalist administrators; and the predominance of patron–client relationships. Copyright © 2001 John Wiley & Sons. Ltd.
Local Government Restructuring: Privatization and Its Alternatives
Authors: Warner Mildred , Hebdon Robert 
Published: September 2002

AbstractLocal government restructuring should no longer be viewed as a simple dichotomy between private and public provision. A 1997 survey of chief elected township and county officials in New York shows that local governments use both private and public sector mechanisms to structure the market, create competition, and attain economies of scale. In addition to privatization and inter‐municipal cooperation, two alternative forms of service delivery not previously researched—reverse privatization and governmental entrepreneurship—are analyzed here. Logistic regression on the 201 responding governments differentiates the decision to restructure from the level and complexity of restructuring. Results confirm that local governments are guided primarily by pragmatic concerns with information, monitoring, and service quality. Political factors are not significant in the restructuring process and unionization is only significant in cases of simple restructuring (privatization or cooperation used alone). Fiscal stress is not a primary motivator, but debt limits are associated with more complex forms of restructuring. Restructuring service delivery requires capacity to take risks and is more common among experienced local officials in larger, higher‐income communities. Restructuring should be viewed as a complex, pragmatic process where governments combine public and private provision with an active role as service provider and market player. © 2001 by the Association for Public Policy Analysis and Management.
Novel point charge models: reliable instruments for­molecular electrostatic
Authors: Oliferenko Alexander A. , Palyulin Vladimir A. , Pisarev Sergei A. , Neiman Alexei V. , Zefirov Nikolai S. 
Published: September 2002

AbstractA novel method to compute atomic charge distribution is proposed. The starting data for the computation are the topology of a molecule and electronegativities of either constituent atoms or atomic orbitals. The topology of a molecule is represented by a molecular graph or, in a more advanced model, by an orbital graph that reflects an orbital constitution of atoms. The distinctive feature of the method is that the starting atomic (orbital) electronegativities equilibrate in the same fashion that electrical potentials do in the nodes of a closed electrical network. Thus, the well‐developed formalism of the theory of electrical circuits was applied for computation of partial atomic charges. In addition, the problem of parametrization of halogens was solved using a specially developed procedures. Comparison of the obtained charges with those produced by means of various computational schemes [Partial Equalization of Orbital Electronegativities (PEOE), Mulliken population analysis, natural population analysis, Bader's AIM, method of generalized atomic polar tensors (GAPT) and an electrostatic potential‐based method, CHELPG] and with some molecular spectral characteristics proves that both models, but especially the orbital graph charge model, provide fast, convenient and reliable methods to calculate theoretically justifiable atomic charges for a variety of chemical species. The developed charge models are well suited for application in many areas of molecular modeling and QSAR/QSPR studies. Copyright © 2001 John Wiley & Sons, Ltd.
Prophylactic oophorectomy versus screening: psychosocial outcomes in women at increased risk of ovarian cancer
Authors: Fry Alison , Busby‐Earle Camille , Rush Robert , Cull Ann 
Published: September 2002

AbstractThis study investigated the psychosocial outcome of prophylactic oophorectomy versus regular screening in women at increased risk of ovarian cancer. Women who had undergone prophylactic oophorectomy (n=29) were compared with women who remained on the ovarian screening programme (n=28). Assessments were made retrospectively by postal questionnaire. The surgical group showed significantly poorer functioning on two sub‐scales of the Short Form (SF)‐36 Health Status Questionnaire (role‐emotional (p=0.04) and social functioning (p=0.01)), and there was a trend (p=0.06) for them to report more menopausal symptoms. General Health Questionnaire (GHQ) scores were significantly higher (p=0.03) in the surgical group. There were no significant differences between the groups for cancer worry or sexual functioning. Experience of the operation was better (p=0.01) and incidence of self‐reported post‐operative problems was lower (p=0.02) for women who had undergone the ‘keyhole’ rather than an ‘open’ procedure. Being pre‐menopausal at the time of surgery predicted higher GHQ (p=0.04) and longer subjective recovery time (p=0.04). Women who have undergone prophylactic oophorectomy may have more physical and emotional symptoms than women who remain on an ovarian cancer screening programme, and may report equivalent levels of cancer worry. Those who are pre‐menopausal at the time of the operation may be particularly vulnerable to psychological distress and take longer to recover post‐operatively. A larger prospective study is needed to evaluate the casual versus causal role of oophorectomy in these findings, and the extent to which it allays patients' fear of cancer. Copyright © 2001 John Wiley & Sons, Ltd.
Combined modality radioimmunotherapy for human prostate cancer xenografts with taxanes and 90yttrium‐DOTA‐peptide‐ChL6
Authors: O'Donnell Robert T. , DeNardo Sally J. , Miers Laird A. , Lamborn Kathleen R. , Kukis David L. , DeNardo Gerald L. , Meyers Frederick J. 
Published: September 2002

AbstractBACKGROUNDTherapy for prostate cancer in the PC3 tumor‐nude mouse model with 90yttrium‐(90Y)‐DOTA‐peptide‐ChL6 (5.55 MBq;150 μCi) has resulted in durable responses. To make radioimmunotherapy (RIT) more effective, the radiation‐enhancing drugs Taxol (paclitaxel) and Taxotere (docetaxel) were tested for synergy with 90Y‐DOTA‐peptide‐ChL6.METHODSNude mice bearing human prostate cancer PC3 xenografts were treated with 90Y‐DOTA‐peptide‐ChL6 (2.78 MBq; 75 μCi) and after 24 hr, paclitaxel (300 or 600 μg), or docetaxel (300 μg). Tumor size, survival, blood counts, and pharmacokinetics were monitored to assess efficacy and toxicity.RESULTSDocetaxel plus RIT had a 67% cure rate, whereas no mice were cured among the RIT alone, chemotherapy alone, or untreated controls. Paclitaxel (600 μg) plus RIT produced a 100% response rate with 20% cures. Average tumor volume was reduced to a greater degree in the combined modality radioimmunotherapy (CMRIT) groups compared to controls and the anti‐tumor response was durable. Myelotoxicity in the combined modality groups (RIT plus paclitaxel or RIT plus docetaxel) were similar to groups receiving the same dose of RIT alone.CONCLUSIONIn the PC3‐tumor nude mouse model, addition of paclitaxel or docetaxel to 90Y‐DOTA‐peptide‐ChL6, in doses clinically achievable in humans, provided therapeutic synergy without increased or excessive toxicity. Prostate 50: 27–37, 2002. © 2002 Wiley‐Liss, Inc.
Evidence for stem cells in cultures of mouse prostate epithelial cells
Authors: Sawicki Janet A. , Rothman Craig J. 
Published: September 2002

AbstractBACKGROUNDPrimary cultures of mouse prostatic epithelial cells were studied to identify cells having stem cell characteristics.METHODSCulture conditions supporting the growth of mouse prostatic epithelial cells were identified. Immunostaining identified cells expressing cytokeratin 5 (K5), cytokeratin 8 (K8), and bcl‐2. Cells with clonogenic capacity were identified by replating dissociated cells from primary colonies.RESULTSOnly 2–4% of prostatic epithelial cells that were plated formed colonies. Most cells cultured for 2–4 days expressed bcl‐2, K5, and K8. After 6 days in culture, colonies had two distinct phenotypes, star‐ or disc‐shaped. In colonies of both phenotypes, only a few cells expressed K5 and bcl‐2, while all cells expressed K8. Upon replating, two‐thirds of star‐shaped colonies gave rise to a single colony; of 29 disc‐shaped colonies, none gave rise to new colonies.CONCLUSIONSColonies deriving from putative prostatic epithelial stem cells are identified. These cells express K5 and bcl‐2 and are clonogenic. Prostate 50: 46–53, 2002. © 2002 Wiley‐Liss, Inc.
Seismic retrofitting of structures with fibre‐reinforced polymers
Authors: Triantafillou T C 
Published: September 2002

AbstractExternally bonded (eb) fibre‐reinforced polymers (FRPs) have been employed extensively throughout the world in numerous rehabilitation applications of reinforced concrete or masonry structures. This paper focuses on the seismic retrofitting (removal of seismic deficiency) of RC elements (mainly columns, but also walls and beam–column joints) and masonry walls by means of FRPs. Basic retrofit issues, namely shear strengthening and increase of confinement at plastic hinge or lap splice regions, are summarized first and a summary of application techniques is given. Some key behaviour and design aspects for shear‐strengthened or FRP‐confined members are provided and a brief description of some recent developments related to the seismic strengthening of beam–column joints is presented. Finally, key issues on the seismic retrofitting of masonry walls for in‐plane or out‐of‐plane action are discussed.