bluuebunny/crossref_metadata_2025_split huggingface dataset:
Malnutrition‐induced myopathy following Roux‐en‐Y gastric bypass
Authors: Hsia Amie W. , Hattab Eyas M. , Katz Jonathan S. 
Published: August 2002

AbstractA 42‐year‐old man developed a myopathy in the setting of malnutrition following Roux‐en‐Y gastric bypass for the treatment of morbid obesity. No specific vitamin or electrolyte deficiency was identified. Muscle biopsy revealed type II fiber atrophy. He recovered after the initiation of continuous enteral feeding. We suggest that malnutrition was the underlying cause of his myopathy. © 2001 John Wiley & Sons, Inc. Muscle Nerve 24: 1692–1694, 2001
Role of sorbitol in the up‐regulation of urinary bladder M2 muscarinic receptors in streptozotocin‐induced diabetic rats
Authors: Tong Yat‐Ching , Chin Wan‐Tai , Cheng Juei‐Tang 
Published: August 2002

AbstractThis study investigated the role of sorbitol, a metabolic product of glucose, in the pathogenesis of rat diabetic cystopathy. Three‐month‐old male Wistar rats were divided into four groups: 1) normal controls; 2) rats rendered diabetic by streptozotocin; 3) rats fed with glucose; and 4) rats injected with sorbitol. The M2 muscarinic receptor (M2‐mAChR) protein and mRNA densities of the bladder tissue were measured by Western immunoblot and Northern blot, respectively. The streptozotocin‐induced diabetic rats were then treated with ONO‐2235, an aldose reductase inhibitor. The bladder M2‐mAChR protein and mRNA were compared between the treated and untreated diabetic rats. The densities of M2‐mAChR protein and mRNA in the bladder tissue were significantly increased in diabetic rats, and rats given either glucose or sorbitol (increases in receptor protein: 27.3 ± 3.3, 19.8 ± 2.3, and 18.0 ± 2.1%; increases in mRNA: 39.6 ± 3.7, 33.1 ± 2.9, and 20.2 ± 2.2%, respectively). When diabetic rats were treated with ONO‐2235, the increases in bladder M2‐mAChR protein and mRNA were significantly alleviated. The findings suggest that sorbitol plays a role in the pathogenesis of diabetic cystopathy in rats rendered diabetic by streptozotocin. Aldose reductase inhibitors may be useful in the treatment and prevention of diabetic cystopathy. Neurourol. Urodynam. 21:154–159, 2002. © 2002 Wiley‐Liss, Inc.
An ultra‐short perineal pad‐test for evaluation of female stress urinary incontinence treatment
Authors: Persson Jan , Bergqvist Christina Etén , Wølner‐Hanssen Pål 
Published: August 2002

AbstractWe assessed the reproducibility and feasibility of a rapid perineal pad‐test designed for evaluation of stress urinary incontinence treatment. In an experimental study, we included 34 women with genuine stress incontinence, 13 with urge incontinence and 10 non‐incontinent volunteers for a repeated pad‐test with a standardized bladder volume (300 mL) and a standardized physical activity during one minute. The pad was weighed before and after the exercise to estimate the volume of any leaked urine. In order to find out the percentage of unselected, incontinent women who had been able to perform a preoperative pad‐test, we identified all 120 women operated on for stress incontinence during a one‐year period in a separate retrospective analysis. In another retrospective analysis, we compared the subjective outcome of laparoscopic colposuspension with the outcome of the test performed before and after the procedure among 93 women with genuine stress incontinence. Among stress incontinent women, the median of the differences in leakage between the first and the second test was 8.5 mL (range 0–60 mL) and the repeatability coefficient was 33.6 mL. None of the 13 women with urge incontinence leaked during the tests. One of the 10 controls leaked (during both tests). Of the unselected women, 104/120 (87%) were able to perform the test. Reduction of leaking after surgery was significantly associated with subjective report of outcome (P < 0.0001). In conclusion, the described pad‐test has an acceptable reproducibility and feasibility making it suitable for follow‐up studies. Neurourol. Urodynam. 20:277–285, 2001. © 2001 Wiley‐Liss, Inc.
Regeneration of detrusor muscle after subtotal cystectomy in the rat: Effects on contractile proteins and bladder mechanics
Authors: Frederiksen Hans , Sjuve Rolf , Arner Anders , Uvelius Bengt 
Published: August 2002

AbstractThe aim of the present study was to determine to what extent adult rats can produce new contracting bladder muscle and to see if such newly formed bladder tissue possesses characteristic mechanical properties or whether the ability to recover mechanically is so pronounced that the prehistory of the bladder is unimportant. Subtotal cystectomy was performed in adult female rats, leading to a pronounced decrease in total bladder weight. At 10 weeks, bladder weight had normalized. The histological appearance of such bladders was similar to that of the controls. Active and passive length–tension relations for the detrusor muscle were determined in controls and up to 10 weeks after surgery. Immediately after surgery active and passive forces showed a leftward shift and maximum active force decreased markedly. With time the length–tension curves shifted back to normal, but a decreased active force still remained at 10 weeks. Detrusor actin concentration and detrusor myosin/actin ratio were unaffected by the subtotal cystectomy. Intermediate filament protein/actin ratio showed a significant but transitory increase. We conclude that there is a remarkable recovery of detrusor muscle function after subtotal cystectomy, leading to a normalization of optimum length for active force and a net synthesis of contractile and cytoskeletal proteins. The ability to produce active force does, however, not fully recover. Neurourol. Urodynam. 20:685–697, 2001. © 2001 Wiley‐Liss, Inc.
Flexible supply contracts for short life‐cycle goods: The buyer's perspective
Authors: Milner Joseph M. , Rosenblatt Meir J. 
Published: August 2002

AbstractIn this paper we analyze a two‐period supply contract which allows for order adjustment by the buyer. The buyer is required to place orders for two periods. After observing initial demand, the buyer is then allowed to adjust the second order, paying a per unit order adjustment penalty. We describe the optimal behavior of the buyer under such a contract, both in determining the initial order quantities and in subsequently adjusting the order. We compare the solution to a contract where no adjustment is allowed and to the case where adjustment is allowed without penalty. We demonstrate that flexible contracts can reduce the potentially negative effect of correlation of demand between two periods. Further, we investigate how the duration of the first period vis‐à‐vis the second period affects the profitability of the buyer as a function of the degree of correlation. © 2002 John Wiley & Sons, Inc. Naval Research Logistics, 49: 25–45, 2002; DOI 10.1002/nav.10002
Rendezvous search on labeled networks
Authors: Alpern Steve 
Published: August 2002

AbstractTwo players are independently placed on a commonly labelled network X. They cannot see each other but wish to meet in least expected time. We consider continuous and discrete versions, in which they may move at unit speed or between adjacent distinct nodes, respectively. There are two versions of the problem (asymmetric or symmetric), depending on whether or not we allow the players to use different strategies. After obtaining some optimality conditions for general networks, we specialize to the interval and circle networks. In the first setting, we extend the work of J. V. Howard; in the second we prove a conjecture concerning the optimal symmetric strategy. © 2002 Wiley Periodicals, Inc. Naval Research Logistics 49: 256–274, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/nav.10011
MR angiographic investigation of transient focal cerebral ischemia in rat
Authors: Besselmann M. , Liu M. , Diedenhofen M. , Franke C. , Hoehn M. 
Published: August 2002

AbstractContrast agent free time‐of‐flight magnetic resonance angiography (TOF‐MRA) was applied to the intraluminal thread occlusion model of experimental stroke in rat. It was combined with perfusion‐ and diffusion‐weighted imaging (PWI and DWI) sequences to correlate occlusion and reopening of the middle cerebral artery with alterations in these well‐established magnetic resonance sequences. Since TOF‐MRA can be repeated without limitations, the time course of vascular patency is demonstrated during an experimental period of up to 8 h (2 h control, 1 h ischemia, 3–6 h reperfusion). With an acquisition time of 10 min, TOF‐MRA proved to be suitable to analyze the vascular state of occlusion and reperfusion repetitively in longitudinal studies. Spatial resolution was sufficient to observe neurovascular structural details. In eight out of 10 animals complete vessel occlusion by the intraluminal thread could be validated by an entirely extinguished signal of the ipsilateral middle cerebral artery (MCA) in the angiograms. This was in accordance with a perfusion deficit in the MCA vascular territory detected by PWI (reduction to 30.4 ± 7.4% relative to contralateral side) and a disturbance of water ion homeostasis monitored by DWI in this area. One animal showed a delayed occlusion after 30 min of MCA occlusion, in another animal vessel occlusion failed. In seven out of the eight successful occlusion experiments there was immediate reperfusion after withdrawal of the thread. One animal showed a delayed reperfusion after suture retraction. Remarkable hemispheric differences in vascular branching of the MCA could be recognized in three out of 10 animals. In conclusion, TOF‐MRA is considered a helpful method to survey even in small laboratory animals the correct time course of vascular occlusion and reopening in experimental ischemia, and provides complementary information to the tissue perfusion status monitored by PWI and the ischemic lesion territory detected by DWI. Copyright © 2001 John Wiley & Sons, Ltd.
Abbreviations used:

ACA,

anterior cerebral artery;

AZACA,

azygos anterior cerebral artery;

AZPA,

azygos pericallosal artery;

CarBif,

carotid bifurcation;

CCA,

common carotid artery;

CCAO,

common carotid artery occlusion;

CP,

caudate‐putamen;

DWI,

diffusion‐weighted imaging;

FLASH,

fast‐low‐angle‐shot;

FOV,

field of view;

Gd‐DTPA,

gadolinium‐diethylene‐triamine‐pentaacetic acid;

ICA,

internal carotid artery;

LDF,

laser doppler flow;

MCA,

middle cerebral artery;

MCAO,

middle cerebral artery occlusion;

MIP,

maximum intensity projection;

MOFrA,

medial orbitofrontal artery;

MR,

magnnetic resonance;

MRA,

magnetic resonance angiography;

MRI,

magnetic resonance imaging;

OlfA,

olfactory artery;

PCA,

posterior cerebral artery;

PPA,

pterygopalatinal artery;

PWI,

perfusion‐weighted imaging;

ROI,

region‐of‐interest;

SI,

signal intensity;

TOF‐MRA,

time‐of‐flight magnetic resonance angiography;

TE,

echo time;

TR,

repetition time.
Unique neuronal tracers show migration and differentiation of SVZ progenitors in organotypic slices
Authors: De Marchis S. , Fasolo A. , Shipley M. , Puche A. 
Published: August 2002

AbstractContinual neurogenesis in the subventricular zone (SVZ) of postnatal and adult mammalian forebrain has been well documented, but the mechanisms underlying cell migration and differentiation in this region are poorly understood. We have developed novel in vivo and in vitro methods to investigate these processes. Using stereotaxic injections of a variety of tracers/tracker [Cholera Toxin β subunit (CTb‐), Fluorogold (FG), and Cell Tracker Green (CTG)], we could efficiently label SVZ cells. Over several days, labeled cells migrate along the rostral migratory stream (RMS) to their final differentiation site in the olfactory bulb (OB). The compatibility of these tracers/trackers with immunohistochemistry allows for cell labeling with multiple dyes (e.g., CTb and CTG) and/or specific cell antigens. To investigate the dynamics of migration we labeled SVZ progenitor cells with small injections of CTG and monitored the movements of individual cells in fresh parasagittal brain slices over several hours using time‐lapse confocal microscopy. Our observations suggest that tangential cell migration along the RMS occurs more rapidly than radial cell migration into the OB granule cell layer. To investigate migration over longer time periods, we developed an in vitro organotypic slice in which labeled SVZ progenitors migrate along the RMS and differentiate within the OB. The phenotypic characteristics of these cells in vitro were equivalent to those observed in vivo. Taken together, these methods provide useful tools investigating cell migration and differentiation in a preparation that maintains the anatomical organization of the RMS. © 2001 John Wiley & Sons, Inc. J Neurobiol 49: 326–338, 2001
Calcium oscillations in neocortical astrocytes under epileptiform conditions
Authors: Tashiro Ayumu , Goldberg Jesse , Yuste Rafael 
Published: August 2002

AbstractMorphological and functional alterations in astrocytic glia are often found in epileptic syndromes, although the exact role of astrocytes in epilepsy is poorly understood. During calcium imaging of epileptiform events in juvenile neocortical slices we previously discovered cells with spontaneous oscillations in their intracellular free calcium concentration ([Ca2+]i). We have now characterized these oscillations using two in vitro models of epilepsy and find that they are produced by astrocytes. Astrocytic oscillations are widespread throughout the imaged territories, are remarkably regular and have long periods, averaging 100 s, which become shorter during development. Astrocytic oscillations are uncorrelated among themselves and with epileptiform events, are blocked by internal release antagonists and are stimulated by caffeine. Astrocytic calcium oscillations could mediate reactive astrogliosis, contribute to the pathogenesis of chronic epileptic syndromes, and be used as a diagnostic test for epileptic tissue. © 2002 Wiley Periodicals, Inc. J Neurobiol 50: 45–55, 2002
Binding characteristics of chondroitin sulfate proteoglycans and laminin‐1, and correlative neurite outgrowth behaviors in a standard tissue culture choice assay
Authors: Snow Diane M. , Smith Jeffrey D. , Gurwell Julie A. 
Published: August 2002

AbstractNeuronal growth cones are capable of sophisticated discrimination of environmental cues, on cell surfaces and in the extracellular matrix, to accomplish navigation during development (generation) and following nervous system injury (regeneration). Choices made by growth cones are commonly examined using tissue culture paradigms in which molecules of interest are purified and substratum‐bound. From observations of growth cone behaviors using these paradigms, assertions are made about choices neuronal growth cones may make in vivo. However, in many cases, the binding, interactions, and conformations of these molecules have not been determined. In the present study, we investigated the binding characteristics of two commonly studied outgrowth regulatory molecules: chondroitin sulfate proteoglycans (CSPGs), which are typically inhibitory to neurite outgrowth during development and following nervous system injury, and laminin, which is typically outgrowth promoting for many neuronal types. Using a novel combination of radiolabeling and quantitative fluorescence, we determined the precise concentrations of CSPGs and laminin‐1 that were bound separately and together in a variety of choice assays. For identically prepared cultures, we correlated neurite outgrowth behaviors with binding characteristics. The data support our working hypothesis that neuronal growth cones are guided by the ratio of outgrowth‐promoting to outgrowth‐inhibiting influences in their environment, i.e., they summate local molecular cues. The response of growth cones to these molecular combinations is most likely mediated by integrins and subsequent activation of signal transduction cascades in growth cones. © 2002 Wiley Periodicals, Inc. J Neurobiol 51: 285–301, 2002
Regulation of the cycling of timeless (tim) RNA
Authors: Wang Garrick K. , Ousley Andrea , Darlington Thomas K. , Chen Dechun , Chen Yifeng , Fu Weili , Hickman Lesley J. , Kay Steve A. , Sehgal Amita 
Published: August 2002

AbstractCircadian rhythms in Drosophila depend upon expression of the timeless (tim) and period (per) genes, which encode interacting components of the endogenous clock. These two clock genes show a robust circadian oscillation in transcription rate as well as RNA and protein levels. Transcriptional activation of both genes requires the basic helix‐loop‐helix (bHLH) PAS transcription factors dCLOCK (dCLK) and CYCLE (CYC), which bind E‐box elements. We investigated the role of E‐box elements in regulating behavioral rhythmicity and tim gene expression. We show that mutation of the upstream E‐box in the tim gene prevents the rescue by tim cDNA sequences of the arrhythmic tim01 phenotype. RNA encoded by this mutated tim transgene fails to cycle and is expressed at low levels. While a tim transgene carrying a wild‐type E‐box restores behavioral rhythms, tim RNA levels are intermediate to those of the mutant E‐box transgenic lines and wild type, and do not display high amplitude cycling. On the other hand, high‐amplitude RNA cycling was consistently obtained with a tim transgene that contains genomic, rather than cDNA, sequences. To identify additional sequences that may be required for tim cycling, we investigated the role of an E‐box in the first intron of the tim gene through cell culture experiments. In these experiments, the presence of this intron did not have any effect on the activation of tim transcription by dCLK/CYC. As the upstream E‐box was implicated in activation by dCLK/CYC in cell culture, we assayed sequences containing this E‐box for association with proteins in fly head extracts. These studies provide the first biochemical evidence for an in vivo complex containing dCLK and CYC that binds the tim upstream sequence and is detected at all times of day. Together, these data highlight molecular mechanisms that are critical for behavioral rhythms. © 2001 John Wiley & Sons, Inc. J Neurobiol 47: 161–175, 2001
Sodium channel distribution on uninnervated and innervated embryonic skeletal myotubes
Authors: Anson Blake D. , Roberts William M. 
Published: August 2002

AbstractAcetylcholine receptor (AChR) and sodium (Na+) channel distributions within the membrane of mature vertebrate skeletal muscle fibers maximize the probability of successful neuromuscular transmission and subsequent action potential propagation. AChRs have been studied intensively as a model for understanding the development and regulation of ion channel distribution within the postsynaptic membrane. Na+ channel distributions have received less attention, although there is evidence that the temporal accumulation of Na+ channels at developing neuromuscular junctions (NMJs) may differ between species. Even less is known about the development of extrajunctional Na+ channel distributions. To further our understanding of Na+ channel distributions within junctional and extrajunctional membranes, we used a novel voltage‐clamp method and fluorescent probes to map Na+ channels on embryonic chick muscle fibers as they developed in vitro and in vivo. Na+ current densities on uninnervated myotubes were approximately one‐tenth the density found within extrajunctional regions of mature fibers, and showed several‐fold variations that could not be explained by a random scattering of single channels. Regions of high current density were not correlated with cellular landmarks such as AChR clusters or myonuclei. Under coculture conditions, AChRs rapidly concentrated at developing synapses, while Na+ channels did not show a significant increase over the 7 day coculture period. In vivo investigations supported a significant temporal separation between Na+ channel and AChR aggregation at the developing NMJ. These data suggest that extrajunctional Na+ channels cluster together in a neuronally independent manner and concentrate at the developing avian NMJ much later than AChRs. © 2001 John Wiley & Sons, Inc. J Neurobiol 48: 42–57, 2001
Comparison of several numerical methods for mechanical systems with impacts
Authors: Janin O. , Lamarque C. H. 
Published: August 2002

AbstractThe modellization of mechanical systems with non‐linearities of impact type leads to discontinuities in the velocity. In this paper, we study some numerical methods adapted to the occurrence of such discontinuities from a single‐degree‐of‐freedom vibro‐impact system. Theoretical results of consistency are given for numerical methods valid for smooth ordinary differential equations, with several kinds of procedures for approximating impact times. The algorithms are applied to classical Newmark and Runge–Kutta schemes, and the numerical behaviour is investigated for two categories of periodic response, either with finite or infinite number of impacts per cycle. These numerical methods are compared to a scheme without explicit computation of impact times. We show that high orders of convergence can be obtained with appropriate schemes, and we discuss the time of computation needed in each case. Copyright © 2001 John Wiley & Sons, Ltd.
Stability of time‐splitting schemes for the Stokes problem with stabilized finite elements
Authors: Picasso Marco , Rappaz Jacques 
Published: August 2002

AbstractThe time‐dependent Stokes problem is solved using continuous, piecewise linear finite elements and a classical stabilization procedure. Four order‐one methods are proposed for the time discretization. The first one is nothing but the Euler backward scheme and requires a large linear system involving the velocity and pressure unknowns to be solved. The other three schemes allow velocity and pressure computations to be decoupled, namely the pressure‐matrix method, a method based on an inexact LU factorization, and an operator splitting method. Stability and condition number estimates are derived. Numerical experiments in two space dimensions confirm the theoretical predictions. © 2001 John Wiley & Sons, Inc. Numer Methods Partial Differential Eq 17:632–656, 2001
Relationship of psychosocial tasks of pregnancy and attentional functioning in the third trimester
Authors: Stark Mary Ann 
Published: August 2002

AbstractBecause childbearing women function in multiple roles, the capacity to focus or concentrate is an important resource while preparing for birth and parenting. In addition to daily tasks that require mental effort, gravidas have psychosocial demands related to pregnancy. The purpose of this study was to examine the relationship between the psychosocial tasks of pregnancy and the capacity to focus or direct attention. A convenience sample of 57 pregnant women in their third trimester was recruited from prenatal education classes to participate in this descriptive correlational study. After other variables thought to influence attentional functioning were considered, women experiencing the greatest conflict in psychosocial tasks had the most difficulty using directed attention and more negatively evaluated their attentional functioning. In order to empower gravidas to participate in their health care, it is important for researchers and practitioners to understand and support directed attentional functioning, an important area for nursing care and research. © 2001 John Wiley & Sons, Inc. Res Nurs Health 24: 194–202, 2001