bluuebunny/crossref_metadata_2025_split huggingface dataset:
Blood pool contrast‐enhanced MRI detects suppression of microvascular permeability in early postinfarction reperfusion after nicorandil therapy
Authors: Krombach Gabriele A. , Higgins Charles B. , Chujo Mitsuaki , Saeed Maythem 
Published: August 2002

AbstractNicorandil is an adenosine triphosphate‐sensitive potassium channel opener with a nitrate‐like effect. It is approved for clinical use in Europe and Japan as an antianginal drug. The purpose of this investigation was to assess the acute effects of nicorandil therapy on microvascular injury using the blood pool MR contrast medium, NC100150 injection (Clariscan™). Microvascular injury was produced in 24 rats using 45 min of coronary occlusion / 3 hr reperfusion. Nicorandil was infused at 15 min of occlusion and during reperfusion. Control animals received a saline solution. MR imaging was used to characterize microvascular permeability, quantify the extent of microvascular injury, LV volume, and wall thickness. Hyperenhancement at 30 min after administration of 0.05 mmol/kg Clariscan mapped the extent of ischemia‐induced loss of microvascular integrity. The accumulation of Clariscan in the injured region was significantly suppressed in nicorandil compared to control rats. Nicorandil reduced the extent of microvascular injury from 44 ± 2% to 18 ± 2% (P < 0.01) and true infarction size from 29 ± 2% to 12 ± 1%. The extent of the hyperenhanced region correlated with the true size of area at risk at autopsy. On spin‐echo MRI during end‐diastole, nicorandil reduced LV end‐diastolic volume and preserved wall thickness in remote myocardium; both parameters are markers of LV dilatation caused by acute infarction (remodeling). In conclusion, blood pool contrast‐enhanced MRI has the potential to depict and quantify the extent of microvascular permeability and injury. Nicorandil suppressed microvascular permeability, reduced infarction size, and improved LV function in early postinfarction reperfusion. Magn Reson Med 47:896–902, 2002. © 2002 Wiley‐Liss, Inc.
Perfusion‐based high‐resolution functional imaging in the human brain at 7 Tesla
Authors: Pfeuffer Josef , Adriany Gregor , Shmuel Amir , Yacoub Essa , Van De Moortele Pierre‐Francois , Hu Xiaoping , Ugurbil Kamil 
Published: August 2002

AbstractPerfusion‐based MRI measures cerebral blood flow (CBF) at the capillary level and can be used for functional studies based on the tight spatial coupling between brain activity and blood flow. Obtaining functional CBF maps with high spatial resolution is a major challenge because the CBF signal is intrinsically low and the SNR is critical. In the present work, CBF‐based functional imaging was performed at a considerably smaller voxel size than previously reported in humans. High‐resolution CBF maps were obtained with voxel sizes as small as 0.9 × 0.9 × 1.5 mm3 in the human brain. High sensitivity was made possible by signal‐to‐noise gains at the high magnetic field of 7 T and by using a novel RF combination coil design. In addition, a reduction of the field‐of‐view was critical to achieve 0.9‐mm in‐plane resolution with gradient‐echo echo‐planar imaging in a single shot. Functional CBF data were compared with functional BOLD data to reveal that, for CBF, large contrast‐ to‐noise gains were obtained at high spatial resolution, indicating that the functional CBF response was more localized. High‐resolution functional CBF imaging is significant for neuroscience research because it provides better localization and more specific information than BOLD for monitoring brain function. Magn Reson Med 47:903–911, 2002. © 2002 Wiley‐Liss, Inc.
[1‐13C] glucose MRS in chronic hepatic encephalopathy in man
Authors: Blüml Stefan , Moreno‐Torres Angel , Ross Brian D. 
Published: August 2002

Abstract[1‐13C]‐labeled glucose was infused intravenously in a single dose of 0.2 g/kg body weight over 15 min in six patients with chronic hepatic encephalopathy, and three controls. Serial 13C MR spectra of the brain were acquired. Patients exhibited the following characteristics relative to normal controls: 1) Cerebral glutamine concentration was increased (12.6 ± 3.8 vs. 6.5 ± 1.9 mmol/kg, P < 0.006) and glutamate was reduced (8.2 ± 1.0 vs. 9.9 ± 0.6 mmol/kg, P < 0.02). 2) 13C incorporation into glutamate C4 and C2 positions was reduced in patients (80 min after start of infusion C4: 0.43 ± 0.09 vs. 0.84 ± 0.15 mmol/kg, P < 0.001; C2: 0.20 ± 0.03 vs. 0.45 ± 0.07 mmol/kg, P < 0.0001). 3) 13C incorporation into bicarbonate was delayed (90 ± 21 vs. 40 ± 10 min, P < 0.003), and the time interval between detection of glutamate C4 and C2 labeling was longer in patients (22 ± 8 vs. 12 ± 3 min, P < 0.03). 4) Glutamate C2 turnover time was reduced in chronic hepatic encephalopathy (17.1 ± 6.8 vs. 49.6 ± 8.7 min, P < 0.0002). 5) 13C accumulation into glutamine C2 relative to its substrate glutamate C2 increased progressively with the severity of clinical symptoms (r = 0.96, P < 0.01). These data indicate disturbed neurotransmitter glutamate/glutamine cycling and reduced glucose oxidation in chronic hepatic encephalopathy. [1‐13C] glucose MRS provides novel insights into disease progression and the pathophysiology of chronic hepatic encephalopathy. Magn Reson Med 45:981–993, 2001. © 2001 Wiley‐Liss, Inc.
Quantitative model for the interecho time dependence of the CPMG relaxation rate in iron‐rich gray matter
Authors: Jensen J.H. , Chandra R. , Yu H. 
Published: August 2002

AbstractA quantitative model is proposed for computing the dependence on the interecho time of the NMR relaxation rate in iron‐rich gray matter obtained with a Carr‐Purcell‐Meiboom‐Gill sequence. The model consists of representing oligodendrocytes as identical magnetic spheres arranged in a spatially random pattern, and in approximating water diffusion as isotropic and unrestricted. Predictions of the model are calculated numerically using a Monte Carlo technique and, for the weak field limit, using an analytic formula. The model is shown to provide a good fit to experimental measurements of in vitro samples of monkey brain at field levels of 1.0 T and 1.5 T. These field levels are not sufficient to fully determine the model parameters, but it is argued that this may be possible at 3.0 T. The model is potentially of value for multiple‐spin‐echo MRI studies of iron‐related neurodegenerative disorders, such as Parkinson's disease. In particular, the model can be applied to correlate MRI data with the cellular distribution of iron in gray matter. Magn Reson Med 46:159–165, 2001. © 2001 Wiley‐Liss, Inc.
Motoneurons: A preferred firing range across vertebrate species?
Authors: Hornby T. George , McDonagh Jennifer C. , Reinking Robert M. , Stuart Douglas G. 
Published: August 2002

AbstractThe term “preferred firing range” describes a pattern of human motor unit (MU) unitary discharge during a voluntary contraction in which the profile of the spike‐frequency of the MU's compound action potential is dissociated from the profile of the presumed depolarizing pressure exerted on the unit's spinal motoneuron (MN). Such a dissociation has recently been attributed by inference to the presence of a plateau potential (PP) in the active MN. This inference is supported by the qualitative similarities between the firing pattern of human MUs during selected types of relatively brief muscle contraction and that of intracellularly stimulated, PP‐generating cat MNs in a decerebrate preparation, and turtle MNs in an in vitro slice of spinal cord. There are also similarities between the stimulus‐response behavior of intracellularly stimulated turtle MNs and human MUs during the elaboration of a slowly rising voluntary contraction. This review emphasizes that there are a variety of open issues concerning the PP. Nonetheless, a rapidly growing body of comparative vertebrate evidence supports the idea that the PP and other forms of non‐linear MN behavior play a major role in the regulation of muscle force, from the lamprey to the human. © 2002 Wiley Periodicals, Inc. Muscle Nerve 25: 000–000, 2002
The motor cortex and amyotrophic lateral sclerosis
Authors: Eisen Andrew , Weber Markus 
Published: August 2002

AbstractOn theoretical grounds, abnormalities of the motor cortex in patients with amyotrophic lateral sclerosis (ALS) could lead to anterograde (“dying‐forward”) transneuronal degeneration of the anterior horn cells as suggested by Charcot. Conversely, retrograde (“dying‐back”) degeneration of the corticospinal tracts could affect the motor cortex. Evidence derived from clinical, neuropathological, static, and functional imaging, and physiological studies, favors the occurrence of anterograde degeneration. It is hypothesized that transneuronal degeneration in ALS is an active excitotoxic process in which live but dysfunctional corticomotoneurons, originating in the primary motor cortex, drive the anterior horn cell into metabolic deficit. When this is marked, it will result in more rapid and widespread loss of lower motor neurons. In contrast, slow loss of corticomotoneurons, as occurs in primary lateral sclerosis (PLS), precludes excitotoxic drive and is incompatible with anterograde degeneration. Preservation of slow‐conducting non‐M1 direct pathways in PLS is not associated with excitotoxicity, and anterior horn cells survive for long periods of time. © 2001 John Wiley & Sons, Inc. Muscle Nerve 24: 564–573, 2001
Lidocaine selectively blocks abnormal impulses arising from noninactivating Na channels
Authors: Khodorova Alla , Meissner Konrad , Leeson Stanley , Strichartz Gary R. 
Published: August 2002

AbstractAbnormal, repetitive impulse firing arising from incomplete inactivation of Na+channels may be involved in several diseases of muscle and nerve, including familial myotonias and neuropathic pain syndromes. Systemic local anesthetics have been shown to have clinical efficacy against myotonias and some forms of neuropathic pain, so we sought to develop an in vitro model to examine the cellular basis for these drugs' effects. In frog sciatic nerves, studied in vitro by the sucrose‐gap method, peptide α‐toxins from sea anemone (ATXII) or scorpion (LQIIa) venom, which inhibit Na+channel inactivation, induced repetitively firing compound action potentials (CAPs) superimposed on a plateau depolarization lasting several seconds. The initial spike of the CAP was unaffected, but the plateau and repetitive firing were strongly suppressed by 5–30 μM lidocaine. Lidocaine caused a rapid, concentration‐dependent decay of the plateau, quantitatively consistent with blockade of open Na+channels. Early and late repetitive firing were equally suppressed by lidocaine with IC50 = 10 μM. After washout of lidocaine and LQIIa, the plateau and repetitive firing remained for > 1 h, showing that lidocaine had not caused dissociation of channel‐bound α‐toxin. These findings indicate that therapeutic concentrations of lidocaine can reverse the “abnormal” features of action potentials caused by non‐inactivating Na+channels without affecting the normal spike component. © 2001 John Wiley & Sons, Inc. Muscle Nerve 24: 634–647, 2001
Thalidomide neuropathy in patients treated for metastatic prostate cancer
Authors: Molloy F.M. , Floeter M.K. , Syed N.A. , Sandbrink F. , Culcea E. , Steinberg S.M. , Dahut W. , Pluda J. , Kruger E.A. , Reed E. , Figg W.D. 
Published: August 2002

AbstractWe prospectively evaluated thalidomide‐induced neuropathy using electrodiagnostic studies. Sixty‐seven men with metastatic androgen‐independent prostate cancer in an open‐label trial of oral thalidomide underwent neurologic examinations and nerve conduction studies (NCS) prior to and at 3‐month intervals during treatment. NCS included recording of sensory nerve action potentials (SNAPs) from median, radial, ulnar, and sural nerves. SNAP amplitudes for each nerve were expressed as the percentage of its baseline, and the mean of the four was termed the SNAP index. A 40% decline in the SNAP index was considered clinically significant. Thalidomide was discontinued in 55 patients for lack of therapeutic response. Of 67 patients initially enrolled, 24 remained on thalidomide for 3 months, 8 remained at 6 months, and 3 remained at 9 months. Six patients developed neuropathy. Clinical symptoms and a decline in the SNAP index occurred concurrently. Older age and cumulative dose were possible contributing factors. Neuropathy may thus be a common complication of thalidomide in older patients. The SNAP index can be used to monitor peripheral neuropathy, but not for early detection. © 2001 John Wiley & Sons, Inc. Muscle Nerve 24: 1050–1057, 2001
Risk factors for hematological malignancy in polyneuropathy associated with monoclonal gammopathy
Authors: Eurelings Marijke , Notermans Nicolette C. , Van de Donk Niels W.C.J. , Lokhorst Henk M. 
Published: August 2002

AbstractPolyneuropathy associated with monoclonal gammopathy of undetermined significance (MGUS) is a well‐known disease entity. Of the patients with monoclonal gammopathy without neuropathy, 25% develop a hematological malignancy during long‐term follow‐up. Whether the frequency of hematological malignancy is similar in patients with polyneuropathy associated with monoclonal gammopathy and whether hematological screening is necessary in these patients is unknown. To determine the frequency of and risk factors for a hematological malignancy, we investigated 104 patients with polyneuropathy and monoclonal gammopathy. Potential diagnostic variables were obtained from medical history, physical and neurological examination, and laboratory analysis. The associations between potential diagnostic variables and outcome, hematological malignancy, were evaluated by univariable and multivariable logistic‐regression analysis. Among our patients, 23 had a hematological malignancy (8 multiple myeloma, 10 low‐grade lymphoma, 3 plasmacytoma, 1 Castleman's disease and 1 POEMS syndrome [polyneuropathy, organomegaly, endocrinopathy, M‐protein, and skin changes]). Weight loss, progression of the neuropathy, and an M‐protein level > 1 g/L were independent risk factors for malignancy. Extensive screening is indicated in patients with these features. © 2001 John Wiley & Sons, Inc. Muscle Nerve 24: 1295–1302, 2001
Carpal tunnel syndrome and hand configuration
Authors: Chroni Elisabeth , Paschalis Christos , Arvaniti Chrisa , Zotou Kerasia , Nikolakopoulou Anastasia , Papapetropoulos Thodoros 
Published: August 2002

AbstractThe likelihood that hand configuration is related to the development of carpal tunnel syndrome (CTS) was examined in this study. Based on neurophysiological criteria, 50 female subjects with CTS and 50 healthy female controls were selected and their external hand dimensions were measured. Our results showed that the palm length and third digit length were significantly shorter and the palm width larger in the subjects with CTS compared with controls. Regression analysis demonstrated that the hand ratio [(palm + third digit length)/palm width] was significantly correlated with median nerve conduction measurements. The hand ratio may be a simple and useful predictive measurement in determining the tendency for CTS. © 2001 John Wiley & Sons, Inc. Muscle Nerve 24: 1607–1611, 2001
On failure criteria for anisotropic cohesive‐frictional materials
Authors: Pietruszczak S. , Mroz Z. 
Published: August 2002

AbstractAnisotropic failure criteria are formulated using two different approaches. The first one employs a spatial distribution of strength parameters and defines the failure condition in terms of traction components acting on the critical plane. The second one incorporates a microstructure tensor and the relevant mixed invariants. Both formulations are illustrated by some numerical examples. In particular, the variation of strength with orientation of the sample is examined for a series of uniaxial compression tests. Copyright © 2001 John Wiley & Sons, Ltd.
Development of a non‐invasive strategy to classify bladder outlet obstruction in male patients with LUTS
Authors: Pel J.J.M. , Bosch J.L.H.R. , Blom J.H.M. , Lycklama à Nijeholt A.A.B. , van Mastrigt R. 
Published: August 2002

AbstractTo diagnose bladder outlet obstruction in male patients with lower urinary tract symptoms (LUTS), it is necessary to measure the bladder pressure via a transurethral (or suprapubic) catheter. This procedure incurs some risk of urinary tract infection and urethral trauma and is sometimes painful to the patient. We developed an external condom catheter to measure non‐invasively the bladder pressure and developed a strategy to classify bladder outlet obstruction (BOO) based on this measurement. Seventy‐five patients with a wide range of urological diagnoses underwent a pressure‐flow study followed by a non‐invasive study. We tested five different strategies to classify the patients using the provisional International Continence Society (ICS) method for definition of obstruction as the gold standard. Leakage of the external catheter occurred in eight (40%) of the first 20 tested patients. In the remaining 55 patients, only five (9%) of the measurements failed because of leakage. Of the 75 patients, 56 were successfully tested non‐invasively. According to the ICS nomogram, the PFS showed that 22 of these patients were non‐obstructed, 12 patients were equivocal, and 22 patients were obstructed. Ten of these 56 patients strained, and we found that the relatively high abdominal pressures in these patients were not reflected in the externally measured bladder pressure. Of the remaining 46 patients, 12 of 13 non‐obstructed patients and 30 of 33 combined equivocal and obstructed patients could be correctly classified. We developed a simple, non‐invasive classification strategy to identify BOO in those male patients who did not strain during voiding. Neurourol. Urodynam. 21:117–125, 2002. © 2002 Wiley‐Liss, Inc.
Determination of suppliers' optimal quantity discount schedules with heterogeneous buyers
Authors: Wang Qinan 
Published: August 2002

AbstractAlthough the quantity discount problem has been extensively studied in the realm of a single supplier and a single buyer, it is not well understood when a supplier has many different buyers. This paper presents an analysis of a supplier's quantity discount decision when there are many buyers with different demand and cost structures. A common discrete all‐unit quantity discount schedule with many break points is used. After formulating the model, we first analyze buyers' responses to a general discrete quantity discount schedule. This analysis establishes a framework for a supplier to formulate his quantity discount decision. Under this framework, the supplier's optimal quantity discount schedule can be formulated and solved by a simple non‐linear programming model. The applicability of the model is discussed with an application for a large U.S. distribution network. © 2002 John Wiley & Sons, Inc. Naval Research Logistics, 49: 46–59, 2002; DOI 10.1002/nav.1052
Managing computing resources in active intranets
Authors: Chellappa Ramnath K. , Gupta Alok 
Published: August 2002

AbstractThe objective of this paper is to present an economic pricing‐based resource management technique for Intranets that has the capability of managing Intranet resources from an organizational perspective. We discuss the adoption of this pricing scheme at three stages: application level, node level, and data‐stream level implementations. These three levels demonstrate how a pricing based approach can be used with the current technology and also be migrated to evolving network architectures such as active networks. Copyright © 2002 John Wiley & Sons, Ltd.
Pigment‐dispersing factor in the locust abdominal ganglia may have roles as circulating neurohormone and central neuromodulator
Authors: Persson Magnus G. S. , Eklund Malin B. , Dircksen Heinrich , Muren J. Eric , Nässel Dick R. 
Published: August 2002

AbstractPigment‐dispersing factor (PDF) is a neuropeptide that has been indicated as a likely output signal from the circadian clock neurons in the brain of Drosophila. In addition to these brain neurons, there are PDF‐immunoreactive (PDFI) neurons in the abdominal ganglia of Drosophila and other insects; the function of these neurons is not known. We have analyzed PDFI neurons in the abdominal ganglia of the locust Locusta migratoria. These PDFI neurons can first be detected at about 45% embryonic development and have an adult appearance at about 80%. In each of the abdominal ganglia (A3–A7) there is one pair of lateral PDFI neurons and in each of the A5–A7 ganglia there is additionally a pair of median neurons. The lateral neurons supply varicose branches to neurohemal areas of the lateral heart nerves and perisympathetic organs, whereas the median cells form processes in the terminal abdominal ganglion and supply terminals on the hindgut. Because PDF does not influence hindgut contractility, it is possible that also these median neurons release PDF into the circulation. Release from one or both the PDFI neuron types was confirmed by measurements of PDF‐immunoreactivity in hemolymph by enzyme immunoassay. PDF applied to the terminal abdominal ganglion triggers firing of action potentials in motoneurons with axons in the genital nerves of males and the 8th ventral nerve of females. Because this action is blocked in calcium‐free saline, it is likely that PDF acts via interneurons. Thus, PDF seems to have a modulatory role in central neuronal circuits of the terminal abdominal ganglion that control muscles of genital organs. © 2001 John Wiley & Sons, Inc. J Neurobiol 48: 19–41, 2001
Cellular competence plays a role in photoreceptor differentiation in the developing Xenopus retina
Authors: Rapaport David H. , Patheal Sherry L. , Harris William A. 
Published: August 2002

AbstractFactors in the environment appear to be responsible for inducing many of the cell fates in the retina, including, for example, photoreceptors. Further, there is a conserved order of histogenesis in the vertebrate retina, suggesting that a temporal mechanism interacts in the control of cellular determination. The temporal mechanism involved could result from different inducing signals being released at different times. Alternatively, the inducing signals might be present at many stages, but an autonomous clock could regulate the competence of cells to respond to them. To differentiate between these mechanisms, cells from young embryonic retinas were dissociated and grown together with those from older embryos, and the timing of photoreceptor determination assayed. Young cells appeared uninfluenced by older cells, expressing photoreceptor markers on the same time schedule as when cultured alone. A similar result was obtained when the heterochronic mixing was done in vivo by grafting a small plug of optic vesicle from younger embryos into older hosts. Even the graft cells at the immediate margin of the transplant failed to express photoreceptor markers earlier than normal, despite their being in contact with older, strongly expressing host cells. We conclude that retinal progenitors intrinsically acquire the ability to respond to photoreceptor‐inducing cues by a mechanism that runs on a cell autonomous schedule, and that the conserved order of histogenesis is based in part on this competence clock. © 2001 John Wiley & Sons, Inc. J Neurobiol 49: 129–141, 2001