bluuebunny/crossref_metadata_2025_split huggingface dataset:
Cesium‐133: A potential reporter of the hepatic uptake of contrast agents
Authors: Colet Jean‐Marie , Lecomte Sophie , Vander Elst Luce , Muller Robert N. 
Published: August 2002

AbstractNMR spectroscopy of intracellularly located 133Cs has been used to monitor the uptake of Gd‐EOB‐DTPA by the isolated rat liver. As shown by 31P spectroscopy, accumulation of 133Cs ions in hepatocytes does not produce detectable effects on the metabolism. The hepatic internalization of Gd‐EOB‐DTPA was followed by the paramagnetic relaxation enhancement of the intracellular 133Cs ions, and confirmed by parallel quantitations of Gd and Cs run by inductively coupled plasma (ICP) analysis of liver samples and aliquots of perfusate. The relaxation data significantly underestimate the Gd content, suggesting a potential compartmentation of Cs+ and/or the contrast agent. Magn Reson Med 45:711–715, 2001. © 2001 Wiley‐Liss, Inc.
Measuring the human retinal oxygenation response to a hyperoxic challenge using MRI: Eliminating blinking artifacts and demonstrating proof of concept
Authors: Berkowitz Bruce A. , McDonald Christopher , Ito Yasuki , Tofts Paul S. , Latif Zahid , Gross Jason 
Published: August 2002

AbstractThe retinal oxygenation response to a hyperoxic challenge measured using MRI appears to be an early and accurate marker of retinopathy risk in experimental models, with promising clinical potential. However, the application of this technique in humans is limited by blinking artifacts that can confound detection of subtle signal intensity changes. We asked subjects to refrain from blinking during a 12‐s fast low‐angle shot (FLASH) image, and to blink if needed during the following 3‐s rest period. This no‐blink blink cycle was repeated sequentially 20 times during either room‐air or 100% oxygen breathing. Significant change (P < 0.05) was detected for the first time from the resultant blinking‐artifact‐free images in the preretinal vitreous oxygen tension (upper limit of about 13 mm Hg (1.8 KPa, N = 3)) following a 10‐min hyperoxic inhalation challenge. These results provide the proof‐of‐concept data needed for future MRI evaluation of the retinal oxygenation response and human retinopathy, such as diabetic retinopathy. Magn Reson Med 46:412–416, 2001. © 2001 Wiley‐Liss, Inc.
Assessment of 3D proton MR echo‐planar spectroscopic imaging using automated spectral analysis
Authors: Ebel Andreas , Soher Brian J. , Maudsley Andrew A. 
Published: August 2002

AbstractFor many clinical applications of proton MR spectroscopic imaging (MRSI) of the brain, diagnostic assessment is limited by insufficient coverage provided by single‐ or multislice acquisition methods as well as by the use of volume preselection methods. Additionally, traditional spectral analysis methods may limit the operator to detailed analysis of only a few selected brain regions. It is therefore highly desirable to use a fully 3D approach, combined with spectral analysis procedures that enable automated assessment of 3D metabolite distributions over the whole brain. In this study, a 3D echo‐planar MRSI technique has been implemented without volume preselection to provide sufficient spatial resolution with maximum coverage of the brain. Using MRSI acquisitions in normal subjects at 1.5T and a fully automated spectral analysis procedure, an assessment of the resultant spectral quality and the extent of viable data in human brain was carried out. The analysis found that 69% of brain voxels were obtained with acceptable spectral quality at TE = 135 ms, and 52% at TE = 25 ms. Most of the rejected voxels were located near the sinuses or temporal bones and demonstrated poor B0 homogeneity and additional regions were affected by stronger lipid contamination at TE = 25 ms. Magn Reson Med 46:1072–1078, 2001. © 2001 Wiley‐Liss, Inc.
Effect of exercise on stability of chronically enlarged motor units
Authors: Tam Siu Lin , Archibald Vey , Tyreman Neil , Gordon T. 
Published: August 2002

AbstractChronic denervation syndromes such as the post‐polio syndrome are associated with progressive muscle weakness and fatigue after motoneuron death. Neither the etiology nor the management of these syndromes is clear. To address this issue, we partially denervated rat hindlimb muscles for 1 or 12 months and examined whether chronically enlarged motor units (MUs) become destabilized with time and further destabilized by daily running on exercise wheels. MU enlargement, measured electrophysiologically and morphologically was significantly reduced at 12 months in extensively denervated muscles, and to a lesser extent in moderately denervated muscles, as compared to the findings at 1 month. A 1‐month period of running exercise further reduced the size of the chronically enlarged MUs in the extensively denervated muscles. We have therefore (1) successfully established a rat model of time‐related MU size reduction, in which destabilization of chronically enlarged MUs results in loss of axonal terminals, and (2) demonstrated that nonphysiological activity has small but significant effects of further destabilizing the chronically enlarged MUs. © 2002 Wiley Periodicals, Inc. Muscle Nerve 25: 000–000, 2002 DOI 10.1002/mus.10057
Presymptomatic motor neuron loss and reactive astrocytosis in the SOD1 mouse model of amyotrophic lateral sclerosis
Authors: Feeney Sandra J. , McKelvie Penelope A. , Austin Lawrence , Jean‐Francois M.J. Bernadette , Kapsa Robert , Tombs Stefania M. , Byrne Edward 
Published: August 2002

AbstractIn familial amyotrophic lateral sclerosis (fALS), there is a need to establish more precisely the progression of the disease, particularly whether there is gradual presymptomatic neuronal loss or an abrupt loss coinciding with the symptomatic stage. To elucidate this, we investigated the progression of motor neuron loss through morphological techniques, reactive astrocytosis, and expression of ubiquitin and neurofilament proteins, by immunohistochemistry, in SOD1 G93A mice with a protracted disease course and control mice. Loss of motor neurons in SOD1 G93A mice followed a biphasic progression, with an initial loss at 126 days of age, followed by a gradual loss from onset of symptoms through to end‐stage disease. Reactive astrocytosis was first observed at 70 days of age and showed a gradual increase through to end‐stage disease. This suggests that there is a need for early detection of fALS cases, and potential therapeutic treatments may be more beneficial if administered at an early stage. © 2001 John Wiley & Sons, Inc. Muscle Nerve 24: 1510–1519, 2001
Distal excitability properties of median motor axons
Authors: Walters R. Jon L. , Kiernan Matthew C. , Murray Nicholas M.F. , Bostock Hugh 
Published: August 2002

AbstractExcitability properties were recorded from 14 volunteers following stimulation of the recurrent motor branch of the median nerve in the palm. Distal stimulation resulted in significantly lower strength‐duration time constant and lower threshold during prolonged hyperpolarization than did wrist stimulation in the same subjects. These differences may be geometric in origin or alternatively may arise from functional changes distally, particularly reduced expression of persistent Na+ conductances and more hyperpolarization‐activated current. Excitability studies using palm stimulation provide information closer to the neuromuscular junction, where membrane properties are preferentially affected in a variety of clinical conditions. © 2001 John Wiley & Sons, Inc. Muscle Nerve 24: 1695–1698, 2001
Interactions between prostate volume, filling cystometric estimated parameters, and data from pressure‐flow studies in 565 men with lower urinary tract symptoms suggestive of benign prostatic hyperplasia
Authors: Eckhardt Mardy D. , Venrooij Ger E.P.M. van , Boon Tom A. 
Published: August 2002

AbstractThe aim of this study was to establish the characteristics and to investigate the interactions between prostate volume, degree of obstruction, bladder contractility, the prevalence of residual volume, bladder compliance, bladder capacities, and the prevalence of instability in a large, well‐defined group of men with lower urinary tract symptoms (LUTS) suggestive of benign prostatic hyperplasia (BPH). The 565 consecutive men included in this study met the criteria of the International Consensus Committee on BPH and voided more than 150 mL during uroflowmetry. Their residual urine volume and prostate size were estimated, and filling cystometry and pressure‐flow studies were performed. Fifty‐three percent of the men appeared to have obstruction. We found a positive correlation between prostate volume and Schäfer's obstruction grade, except that mean prostate volume decreased at Schäfer's grades 5 and 6. Significant negative correlations existed between Schäfer's grade and cystometric bladder capacity and effective capacity. Bladder outlet obstruction results in incomplete emptying. Of all men, 26% had a significant residual volume ( > 20% of cystometric capacity). Thirty‐nine percent did not have residual volume. Of the 565 men, 46% had an unstable bladder. In particular, patients with an unstable bladder in the sitting and lying positions have a significantly higher Schäfer's grade and contractility grade and a significantly lower cystometric and effective bladder capacity compared with patients without instability. Patients with a residual volume or instability were significantly older. We conclude that in men with LUTS suggestive of BPH, abnormalities of bladder and bladder outlet function vary greatly and have complex mutual interactions. Neurourol. Urodynam. 20:579–590, 2001. © 2001 Wiley‐Liss, Inc.
Protocol for clinical neurophysiologic examination of the pelvic floor
Authors: Podnar Simon , Vodušek David B. 
Published: August 2002

AbstractClinical neurophysiologic examination of the pelvic floor is performed worldwide, but there is no consensus on the choice of tests, nor on technical details of individual methods. Standardized methods are, however, necessary to obtain their valid application in different laboratories for the purpose of collection of normative data, comparison of patient data and organization of multi‐center studies. It is proposed that in patients with suspected “lower motor neuron” type lesions concentric needle electromyography (CNEMG) is the most informative test to detect pelvic floor denervation/reinnervation, and the external anal sphincter (EAS) muscle is the most appropriate muscle to be examined (either in isolation—when a selective lesion is suspected—or in addition to examination of other muscles). An algorithm consisting of standardized tests including a standardized approach to CNEMG examination of the EAS is presented. The proposed electrophysiologic assessment consists of a computer‐assisted analysis of denervation and reinnervation features of the CNEMG signal, a qualitative assessment of reflex and voluntary activation of EAS motor units, and of electrical (or mechanical) elicitation of the bulbocavernosus reflex in those patients in whom manual anogenital stimulation failed to elicit a robust response in the EAS. The proposed protocol could serve as a basis for further studies on validity, sensitivity and specificity of electrophysiologic assessment in patients with different types of “lower motor neuron” involvement of pelvic floor muscles and sacral dysfunction. Neurourol. Urodynam. 20:669–682, 2001. © 2001 Wiley‐Liss, Inc.
Antiandrogen blocks estrogen‐induced masculinization of the song system in female zebra finches
Authors: Grisham William , Lee Janet , McCormick Mary Ellen , Yang‐Stayner Kay , Arnold Arthur P. 
Published: August 2002

AbstractSong behavior and the neural song system that serves it are sexually dimorphic in zebra finches. In this species, males sing and females normally do not. The sex differences in the song system include sex differences in the proportion of neurons that express androgen receptors, which is higher in specific brain regions of males. Estradiol (E2) administered in early development profoundly masculinizes the song system of females, including the proportion of neurons expressing androgen receptors. We examined whether or not the expression of these androgen receptors was causally related to the E2‐induced masculinization of this system by coadministering Flutamide, which blocks androgen action at the receptor, along with E2 at hatching. E2 alone had its usual masculinizing effect on the female song system, measured in adulthood: increasing the size of song nuclei, the size of neurons in HVC, RA, and lMAN, and the number of neurons in HVC. E2's masculinizing action, however, was significantly diminished on all measures by coadministering Flutamide. Indeed, females receiving both E2 and Flutamide were never significantly more masculine than controls on any measure. Flutamide alone had no effect. Our results strongly suggest that the activation of androgen receptors is necessary for the E2‐induced masculinization of the song system in females. © 2002 Wiley Periodicals, Inc. J Neurobiol 51: 1–8, 2002
Developmental and hormonal regulation of NR2A mRNA in forebrain regions controlling avian vocal learning
Authors: Heinrich J. E. , Singh T. D. , Sohrabji F. , Nordeen K. W. , Nordeen E. J. 
Published: August 2002

AbstractDevelopmental changes in the composition of NMDA receptors can alter receptor physiology as well as intracellular signal transduction cascades, potentially shifting thresholds for neural and behavioral plasticity. During song learning in zebra finches, NMDAR currents become faster, and transcripts for the modulatory NR2B subunit of this receptor decrease in lMAN, a region in which NMDAR activation is critical for vocal learning. Using in situ hybridization, we found that NR2A transcripts change reciprocally, increasing significantly in both lMAN (59%) and in another song region, Area X (38%), between posthatch day (PHD) 20 and 40, but not changing further at PHD60 or 80. In adjacent areas not associated with song learning, NR2A mRNA did not change between PHD20–80. Although early song deprivation (which extends the sensitive period for song learning) delays changes in NR2B gene expression and NMDAR physiology within the lMAN, it did not alter NR2A mRNA levels measured at PHD40, 45, or 60. Early testosterone (T) treatment, which disrupts vocal development and accelerates the maturation of both NR2B levels and NMDAR physiology in lMAN, also significantly increased NR2A transcripts measured at PHD35 in lMAN. In Area X, a similar effect of T approached significance. Together with our previous studies, these results show that in a pathway critical for vocal plasticity, the ratio of NR2A:NR2B mRNA rises abruptly early during the sensitive period for song learning. Furthermore, androgen regulation of NMDAR gene expression may alter thresholds for experience‐dependent synaptic change. © 2002 Wiley Periodicals, Inc. J Neurobiol 51: 149–159, 2002
Digger wasp versus cricket: Mechanisms underlying the total paralysis caused by the predator's venom
Authors: Ferber Michael , Hörner Michael , Cepok Sabine , Gnatzy Werner 
Published: August 2002

AbstractThe data presented here describe neurophysiological experiments addressing the question of cellular mechanisms underlying the total paralysis of locomotor behavior in crickets occurring after being stung by females of the digger wasp species Liris niger. The Liris venom effects have been studied by both in vivo recordings from identified neurons of the well‐described giant fiber pathway and in vitro recordings from cultured neurons isolated from the terminal ganglion of crickets. The total paralysis of the prey is characterized by a general block of action potential generation as well as by a block of synaptic transmission. Intracellular recordings from neurons in intact ganglia under single electrode voltage‐clamp conditions, as well as whole‐cell patch‐clamp recordings from cultured cricket neurons consistently show that the block of action potential generation by the Liris venom is due to a block of voltage‐gated sodium inward currents in neurons of the stung ganglia. Furthermore, our data provide evidence that the Liris venom also blocks calcium currents in identified neurosecretory neurons. On the other hand, outward currents are not affected by the Liris venom. The in vitro recordings suggest that the Liris venom contains active venom components, which, at least for the observed block of inward currents, do not require a metabolic modification. Because venom application does not affect the ACh‐induced EPSPs in giant interneurons, the Liris venom does not seem to influence the postsynaptic ACh receptors. The possible pre‐ and postsynaptic sites of venom action and the functional consequences on synaptic transmission within the giant fiber system are discussed. © 2001 John Wiley & Sons, Inc. J Neurobiol 47: 207–222, 2001
Displacement/pressure mixed interpolation in the method of finite spheres
Authors: De Suvranu , Bathe Klaus‐Jürgen 
Published: August 2002

AbstractThe displacement‐based formulation of the method of finite spheres is observed to exhibit volumetric ‘locking’ when incompressible or nearly incompressible deformations are encountered. In this paper, we present a displacement/pressure mixed formulation as a solution to this problem. We analyse the stability and optimality of the formulation for several discretization schemes using numerical inf–sup tests. Issues concerning computational efficiency are also discussed. Copyright © 2001 John Wiley & Sons, Ltd.
A finite element formulation for the simulation of propagating delaminations in layered composite structures
Authors: Wagner W. , Gruttmann F. , Sprenger W. 
Published: August 2002

AbstractThis paper presents a finite element method to simulate growing delaminations in composite structures. The delamination process, using an inelastic material law with softening, takes place within an interface layer having a small, but non‐vanishing thickness. A stress criterion is used to detect the critical points. To prevent mesh‐dependent solutions a regularization technique is applied. The artificial viscosity leads to corresponding stiffness matrices which guarantee stable equilibrium iterations. The essential material parameter which describes the delamination process is the critical energy release rate. The finite element calculations document the robustness and effectivity of the developed model. Extensive parameter studies are performed to show the influence of the introduced geometrical and material quantities. Copyright © 2001 John Wiley & Sons, Ltd.
The application of 3D‐microprofilometry as a tool in the surface diagnosis of fossil and sub‐fossil vertebrate hard tissue. An example from the Pliocene Upper Laetolil Beds, Tanzania
Authors: Kaiser Thomas M. , Katterwe Horst 
Published: August 2002

AbstractNon‐contact optical 3D‐profiling instruments are often used in the study of surface modifications on fossil mammalian bone. The advantage of optical laser scanning for the study of fossil and sub‐fossil bone is its non‐contact nature, allowing the investigation of fragile and poorly preserved surfaces. The high resolution and fast measuring rate of this method make it an alternative to scanning electron microscopy (SEM) investigation if topography is to be visualized. This study analyses clusters of incisions in a suid humeral fragment from the Pliocene Upper Laetolil Beds. The marks show a characteristic crest structure that is also frequently found in mandible marks produced by the Australian termite species Mastotermes darwiniensis. The marks from the Laetolil Beds are, therefore, interpreted as also being caused by insect mandible action. An as yet unknown large insect species capable of modifying bone with their mandibles is thus postulated in the palaeohabitat represented by the hominid‐bearing Upper Laetolil Beds. Copyright © 2001 John Wiley & Sons, Ltd.
Prehistoric marine mammal hunting in context: two western North American examples
Authors: Colten Roger H. 
Published: August 2002

AbstractThe analysis of a particular type of fauna, such as marine mammals, is best understood when all categories of fauna represented are studied. Detailed analysis of a portion of an assemblage, while interesting, can contribute to misleading interpretations of prehistoric human behaviour. Faunal assemblages from coastal shell middens in southern California and Oregon provide examples of the analysis of marine mammals and their relative importance in prehistoric subsistence, economy, and culture change. While marine mammals were important for subsistence and comprise a high proportion of the bones identifiable to the species level in these assemblages, these animals were less important than fish and shellfish in the diet and probably played a limited role in culture change in these regions. Previous studies that suggest a central role for marine mammals in cultural evolution in western North America provide minimal information on other fauna, and use limited analytical methods. Quantification methods that require species level identification (such as minimum number of individuals [MNI]) can exclude much of the faunal data available from dense coastal middens, and may over emphasize some portions of the assemblage, notably large mammals. Analysis at taxonomic levels higher than species and use of several quantification techniques, including meat weight estimates, may help alleviate some of these methodological problems and lead to a better understanding of the role of marine mammals in prehistoric economies. Copyright © 2002 John Wiley & Sons, Ltd.
Preparation of the porous chitosan ­membrane by cryogenic induced phase separation
Authors: Gu Z. Y. , Xue P. H. , Li W. J. 
Published: August 2002

AbstractThe chitosan porous membrane was prepared by extending the principle of thermally induced phase separation (TIPS) for the polymer‐diluent system to the polymer solution at ambient temperature to carry out the cryogenic induced phase separation (CIPS). The porous membrane obtained was characterized by scanning electron microscopy (SEM) and gas permeability. It was found that a specific lacy pore structure morphology corresponding to the TIPS solid–liquid phase separation was formed in the demixing process and the porosity could be more than 70%. The research of demixing mechanism and membrane‐formation process showed that the membrane was stacked through porous lamella. The porosity of the membrane increases and the pore diameter decreases with increasing solidifying temperature. Both the porosity and pore diameter decrease with the chitosan concentration increase. Copyright © 2001 John Wiley & Sons, Ltd.
A model of pulmonary adenocarcinoma in transgenic mice expressing the simian virus 40 T antigen driven by the rat Calbindin‐D9K (CaBP9K) promoter
Authors: Chailley‐Heu Bernadette , Rambaud Caroline , Barlier‐Mur Anne‐Marie , Galateau‐Salle Françoise , Perret Christine , Capron Frédérique , Lacaze‐Masmonteil Thierry 
Published: August 2002

AbstractLung cancer is the most frequent cause of cancer deaths. Its origin and development remain poorly understood, partly because of the lack of pertinent animal models. This study produced transgenic mice expressing the simian virus (SV) 40 T antigen (Tag) driven by a 1011 base‐pair DNA fragment of the rat Calbindin‐D9K (CaBP9K) promoter. All transgenic animals developed multifocal pulmonary tumours with pathological and ultrastructural features consistent with adenocarcinomas. Using immunohistochemistry, northern blot or western blot, tumours were found to express the transcription factor TTF‐1, as well as specific markers of the peripheral airway Clara cells (CC10) and alveolar type II cells (surfactant proteins A, B, C, and D). This model, with its similarities to human adenocarcinoma, should be useful not only for addressing the mechanisms underlying the development and progression of lung cancer, but also for testing new therapeutic approaches. Copyright © 2001 John Wiley & Sons, Ltd.