bluuebunny/crossref_metadata_2025_split huggingface dataset:
Cyclooxygenase‐2 is expressed by cumulus cells during oocyte maturation in cattle
Authors: Nuttinck F. , Reinaud P. , Tricoire H. , Vigneron C. , Peynot N. , Mialot J.P. , Mermillod P. , Charpigny G. 
Published: August 2002

AbstractProstaglandins could be involved in various aspects of final differentiation of ovarian follicles. Prostaglandins are generated by the cyclooxygenase (cox) pathway. Until now, the expression pattern of isoforms cox‐1 and cox‐2 of cyclooxygenase in bovine cumulus‐oocyte complexes (COCs) was unknown. Using immunodetection procedure, we demonstrated in the present study that cox‐2 was expressed by cumulus cells during in vivo and in vitro maturation. Time course induction of cox‐2 expression was investigated during in vitro maturation using Western blot analysis. Specific signal of cox‐2 was markedly evidenced from 6 hr of culture and increased to reach a maximal level at 24 hr of culture. In vitro, cox‐2 expression in COCs was associated with increased concentrations of PGE2 and PGF2α in the maturation medium. In addition, the effects of culture conditions on cox‐2 expression was considered using RT‐PCR and Western‐blot analysis. We demonstrated that the addition of 10 ng/ml of EGF to TCM199 clearly increased the expression level of cox‐2 mRNA and protein. Higher levels of in vitro cox‐2 expression was associated with greater rates of cumulus expansion and oocytes at metaphase II at 24 hr of culture. In conclusion, our present results suggest that cox‐2 expression in cumulus cells may be involved in differentiation of COCs that occurs during oocyte maturation. Mol. Reprod. Dev. 61: 93–101, 2002. © 2002 Wiley‐Liss, Inc.
Roles of the Na,K‐ATPase α4 isoform and the Na+/H+ exchanger in sperm motility
Authors: Woo Alison L. , James Paul F. , Lingrel Jerry B. 
Published: August 2002

AbstractThe Na,K‐ATPase generates electrochemical gradients that are used to drive the coupled transport of many ions and nutrients across the plasma membrane. The functional enzyme is comprised of an α and β subunit and families of isoforms for both subunits exist. Recent studies in this laboratory have identified a biological role for the Na,K‐ATPase α4 isoform in sperm motility. Here we further investigate the role of the Na,K‐ATPase carrying the α4 isoform, showing again that ouabain eliminates sperm motility, and in addition, that nigericin, a H+/K+ ionophore, and monensin, a H+/Na+ ionophore, reinitiate motility. These data, along with the observation that the K+ ionophore valinomycin has no effect on the motility of ouabain‐inhibited sperm, suggest that ouabain may change intracellular H+ levels in a manner that is incompatible with sperm motility. We have also localized NHE1 and NHE5, known regulators of intracellular H+ content, to the same region of the sperm as the Na,K‐ATPase α4 isoform. These data highlight the important role of the Na,K‐ATPase α4 isoform in regulating intracellular H+ levels, and provide evidence suggesting the involvement of the Na+/H+ exchanger, which is critical for maintaining normal sperm motility. Mol. Reprod. Dev. 62: 348–356, 2002. © 2002 Wiley‐Liss, Inc.
Living with support in the community: Predictors of satisfaction with life
Authors: Cummins Robert A. 
Published: August 2002

AbstractEnsuring that people with an intellectual disability have normative levels of life satisfaction is increasingly considered a worthy goal for service providers. This review concerns the determinants of such satisfaction and embeds this literature within the Homeostatic Theory of Subjective Well&hyphen;Being. This posits that life satisfaction is under considerable endogenous control and, as a consequence, does not normally vary in sympathy with changes in the external environment. This situation changes, however, if the environment is sufficiently aversive to defeat such homeostatic control. Under these conditions the circumstances of living correlate with life satisfaction as they wrest control away from the homeostatic system. One important implication is that the measure of life satisfaction may or may not be a sensitive indicator for changes in service provision, depending on the functional status of the homeostatic system. MRDD Research Reviews 7:99&ndash;104, 2001. &copy; 2001 Wiley&hyphen;Liss, Inc.
Phase‐sensitive inversion recovery for detecting myocardial infarction using gadolinium‐delayed hyperenhancement†
Authors: Kellman Peter , Arai Andrew E. , McVeigh Elliot R. , Aletras Anthony H. 
Published: August 2002

AbstractAfter administration of gadolinium, infarcted myocardium exhibits delayed hyperenhancement and can be imaged using an inversion recovery (IR) sequence. The performance of such a method when using magnitude‐reconstructed images is highly sensitive to the inversion recovery time (TI) selected. Using phase‐sensitive reconstruction, it is possible to use a nominal value of TI, eliminate several breath‐holds otherwise needed to find the precise null time for normal myocardium, and achieve a consistent contrast. Phase‐sensitive detection is used to remove the background phase while preserving the sign of the desired magnetization during IR. Experimental results are presented which demonstrate the benefits of both phase‐sensitive IR image reconstruction and surface coil intensity normalization for detecting myocardial infarction (MI). The phase‐sensitive reconstruction method reduces the variation in apparent infarct size that is observed in the magnitude images as TI is changed. Phase‐sensitive detection also has the advantage of decreasing the sensitivity to changes in tissue T1 with increasing delay from contrast agent injection. Magn Reson Med 47:372–383, 2002. Published 2002 Wiley‐Liss, Inc.
MRI of insulitis in autoimmune diabetes
Authors: Moore Anna , Zhe Sun Phillip , Cory David , Högemann Dagmar , Weissleder Ralph , Lipes Myra A. 
Published: August 2002

AbstractDevelopment of imaging techniques that would allow the mapping of immune cells in vivo could greatly aid our understanding of a number of inflammatory and autoimmune diseases. The current study focused on imaging of autoimmune destruction of the insulin‐producing pancreatic beta‐cells by cytotoxic lymphocytes, the cause of insulin‐dependent diabetes mellitus (IDDM; Type 1 diabetes). Using high‐resolution MR microscopy and a conventional clinical MR imaging system, it was possible to visualize the infiltration of immune cells in the diabetic mouse pancreas. Mouse lymphocytes were visualized by magnetically labeling them with recently developed magnetic nanoparticles (CLIO‐Tat). The results from this study could potentially lead to detection of immune infiltration during diabetes formation in vivo, which would be one of the earliest parameters of disease development. Magn Reson Med 47:751–758, 2002. © 2002 Wiley‐Liss, Inc.
Water proton MR properties of human blood at 1.5 Tesla: Magnetic susceptibility,T1,T2,T, and non‐Lorentzian signal behavior
Authors: Spees William M. , Yablonskiy Dmitriy A. , Oswood Mark C. , Ackerman Joseph J.H. 
Published: August 2002

AbstractAccurate knowledge of the magnetic properties of human blood is required for the precise modeling of functional and vascular flow‐related MRI. Herein are reported determinations of the relaxation parameters of blood, employing in vitro samples that are well representative of human blood in situ. The envelope of the blood1H2O free‐induction decay signal magnitude during the first 100 msec following a spin echo at time TE is well‐ described empirically by an expression of the form,S(t) =So· exp{–R· (t– TE) –AR* · (t– TE)2}. The relaxation parametersAR* andRincrease as a function of the square of the susceptibility difference between red blood cell and plasma and depend on the spin‐echo time. The Gaussian component,AR*, should be recognized in accurate modeling of MRI phenomena that depend upon the magnetic state of blood. The magnetic susceptibility difference between fully deoxygenated and fully oxygenated red blood cells at 37°C is 0.27 ppm, as determined independently by MR and superconducting quantum interference device (SQUID) measurements. This value agrees well with the 1936 report of Pauling and Coryell (Proc Natl Acad Sci USA 1936;22:210–216), but is substantially larger than that frequently used in MRI literature. Magn Reson Med 45:533–542, 2001. © 2001 Wiley‐Liss, Inc.
Dynamic contrast‐enhanced MRI of experimental spinal cord injury: In vivo serial studies
Authors: Bilgen Mehmet , Abbe Russell , Narayana Ponnada A. 
Published: August 2002

AbstractThe progression of experimental spinal cord injury (SCI) was followed with in vivo dynamic contrast‐enhanced magnetic resonance imaging (DCE‐MRI) and neurobehavioral studies on postinjury days 0, 2, 4, 7, 10, 14, 17, 21, 28, 35, and 42. Gadopentate dimeglumine (Gd) was administered IV and postcontrast, T1‐weighted, axial images were acquired repetitively for up to 60 min. Images were analyzed to determine the spatial and temporal evolution of the intensity enhancement. A statistical decision mechanism was developed to objectively detect the enhancement. Strong and rapid enhancement was observed at the epicenter of injury, indicating a significant compromise in blood spinal cord barrier. The enhanced regions in each slice were combined to estimate the area and volume of the lesion. On the day of injury, around 85% of the total cord area at the epicenter showed enhancement within the first 15 min of Gd administration. At the same time, the enhanced volumes attained nearly 40% of the total cord volume and extended axially over 8 mm along the cord. These quantities decreased steadily with time, with a concomitant improvement in the motor functions. The volume of enhancement correlated highly with the neurobehavioral tests (r = –0.87). DCE‐MRIs revealed small hyperintense regions distributed inside white matter about two weeks postinjury. Based on histology, these enhancements appear to represent new vessels with “leaky endothelium.” Magn Reson Med 45:614–622, 2001. © 2001 Wiley‐Liss, Inc.
Dynamic contrast‐enhanced MRI using Gd‐DTPA: Interindividual variability of the arterial input function and consequences for the assessment of kinetics in tumors
Authors: Port Ruediger E. , Knopp Michael V. , Brix Gunnar 
Published: August 2002

AbstractGd‐DTPA kinetics in arterial blood was investigated by dynamic MRI in 47 patients with malignant and benign mammary tumors. Signal enhancement was monitored for 10 min after the beginning of a 1‐min infusion of 0.1 mmol/kg Gd‐DTPA. Kinetics in blood was biexponential with median half‐lives of 21 sec and 11.1 min, respectively. Peak signal enhancement and the area under the signal enhancement–time curve varied 2.5‐ and 3.7‐fold between patients. The shortest mean residence time in one of up to three tumor compartments, MRT*, was estimated using either the individual (reference) or a mean population (surrogate) arterial input function (AIF). MRT* (reference estimate) was 1.0 (0–1.5), 1.9 (1.5–2.3), and 2.5 (2.3–2.8) min in carcinomas, fibroadenomas, and mastopathies, respectively (median and interquartile distance). Surrogate estimates were unbiased but differed from the reference estimates 1.5‐fold or more in 23% of cases. AIFs should be monitored individually if accurate estimates of individual MRT* are desired. Magn Reson Med 45:1030–1038, 2001. © 2001 Wiley‐Liss, Inc.
Advances in sensitivity encoding with arbitrary k‐space trajectories
Authors: Pruessmann Klaas P. , Weiger Markus , Börnert Peter , Boesiger Peter 
Published: August 2002

AbstractNew, efficient reconstruction procedures are proposed for sensitivity encoding (SENSE) with arbitrary k‐space trajectories. The presented methods combine gridding principles with so‐called conjugate‐gradient iteration. In this fashion, the bulk of the work of reconstruction can be performed by fast Fourier transform (FFT), reducing the complexity of data processing to the same order of magnitude as in conventional gridding reconstruction. Using the proposed method, SENSE becomes practical with nonstandard k‐space trajectories, enabling considerable scan time reduction with respect to mere gradient encoding. This is illustrated by imaging simulations with spiral, radial, and random k‐space patterns. Simulations were also used for investigating the convergence behavior of the proposed algorithm and its dependence on the factor by which gradient encoding is reduced. The in vivo feasibility of non‐Cartesian SENSE imaging with iterative reconstruction is demonstrated by examples of brain and cardiac imaging using spiral trajectories. In brain imaging with six receiver coils, the number of spiral interleaves was reduced by factors ranging from 2 to 6. In cardiac real‐time imaging with four coils, spiral SENSE permitted reducing the scan time per image from 112 ms to 56 ms, thus doubling the frame‐rate. Magn Reson Med 46:638–651, 2001. © 2001 Wiley‐Liss, Inc.
Adhesion molecule expression in experimental myositis
Authors: Ito Tomoko , Kumamoto Toshihide , Horinouchi Hideo , Yukishige Keiko , Sugihara Rie , Fujimoto Shin , Tsuda Tomiyasu 
Published: August 2002

AbstractExperimental allergic myositis (EAM) in Lewis rats, induced with partially purified myosin, is regarded as a model of human polymyositis. To clarify the role of adhesion molecules in the pathogenesis of EAM in Lewis rats, we investigated intramysial expressions of the intercellular adhesion molecule (ICAM)‐1 and vascular cell adhesion molecule (VCAM)‐1, and the serum level of soluble ICAM‐1 in EAM rats. All the EAM rat muscles had scattered inflammatory foci, as well as cell infiltration and necrosis, by week 4 after the initial immunization (i.e., day 0 after the last immunization). As compared with the control muscles, ICAM‐1 and VCAM‐1 were strongly expressed immunohistochemically in the endothelium of vessels in the endomysium and perimysium, and to lesser extents in the inflammatory infiltrates and on the sarcolemma of nonnecrotic muscle fibers adjacent to the inflammatory infiltrates or invaded muscle fibers. ICAM‐1 in the muscle extracts and sera from EAM rats increased on each test day, as compared with extracts from the normal controls. The values peaked on day 0 after the last immunization, then gradually decreased with time. ICAM‐1 elevations in the muscle extracts were correlated with the percent of sections that had inflammatory lesions (P = 0.032) and the histological scores (P = 0.005) on day 0, whereas there was no significance on days 3 and 7. These findings suggest that the adhesion molecules ICAM‐1 and VCAM‐1 increase in the early stage of EAM, and function in the initiation of the inflammatory process of myositis. © 2002 Wiley Periodicals, Inc. Muscle Nerve 25: 000–000, 2002
Novel COL6A1 splicing mutation in a family affected by mild Bethlem myopathy
Authors: Vanegas Olga Camacho , Zhang Rui‐Zhu , Sabatelli Patrizia , Lattanzi Giovanna , Bencivenga Paola , Giusti Betti , Columbaro Marta , Chu Mon‐Li , Merlini Luciano , Pepe Guglielmina 
Published: August 2002

AbstractBethlem myopathy is an early‐onset benign myopathy characterized by proximal muscular weakness and multiple flexion contractures. It is a dominantly inherited disorder associated with mutations in the three COL6 genes encoding type VI collagen. We detected a g→a substitution at +1 position of COL6A1 intron 3 in a four‐generation Italian family affected by a mild form of Bethlem myopathy. The mutation results in the activation of a cryptic splice donor site at the 3′ end of exon 3, leading to the loss of 66 nucleotides and an “in‐frame” deletion of 22 amino acids in the NH2‐domain. Molecular analysis on fibroblasts of the propositus showed that the mutated mRNA was present and stable, but the mutated protein could not be detected. Western blot and immunofluorescence analyses showed a decreased level of collagen VI synthesis and deposition in fibroblasts of the propositus. Together, the results suggest that the mutated protein was highly unstable and rapidly degraded, and that the mild phenotype was caused by a reduced amount of normal collagen VI microfibrils. In addition, we demonstrated that lymphocytes can be used for the first mutation screening analysis of patients with Bethlem myopathy. © 2002 Wiley Periodicals, Inc. Muscle Nerve 25: 000–000, 2002
Severe autosomal recessive rippling muscle disease
Authors: Koul Roshan L. , Chand Rangnath P. , Chacko Alexander , Ali Mehar , Brown Kevin M. , Bushnarmuth Shivayogi R. , Escolar Diana M. , Stephan Dietrich A. 
Published: August 2002

AbstractRippling muscle disease (RMD) has previously been reported as a skeletal myopathy that was attributed to a defect in the sarcomere. Here we report a new form of RMD that is more severe, characterized by fatal arrhythmic cardiomyopathy and delayed bone age. Mortality has previously not been associated with RMD. With this report we hope to raise awareness that a subset of patients with this clinical entity are predisposed to severe cardiac disease. © 2001 John Wiley & Sons, Inc. Muscle Nerve 24: 1542–1547, 2001
Theoretical investigation of the cavity expansion problem based on a hypoplasticity model
Authors: Osinov V. A. , Cudmani R. 
Published: August 2002

AbstractThe problem of the symmetric quasi‐static large‐strain expansion of a cavity in an infinite granular body is studied. The body is assumed to be dry or fully drained so that the presence of the pore water can be disregarded. Both spherical and cylindrical cavities are considered. Numerical solutions to the boundary value problem are obtained with the use of the hypoplastic constitutive relation calibrated for a series of granular soils. As the radius of the cavity increases, the stresses and the density on the cavity surface asymptotically approach limit values corresponding to a so‐called critical state. For a given soil, the limit values depend on the initial stresses and the initial density. A comparison is made between the solutions for different initial states and different soils. Applications to geotechnical problems such as cone penetration test and pressuremeter test are discussed. Copyright © 2001 John Wiley & Sons, Ltd.
Upper bound limit analysis using linear finite elements and non‐linear programming
Authors: Lyamin A. V. , Sloan S. W. 
Published: August 2002

AbstractA new method for computing rigorous upper bounds on the limit loads for one‐, two‐ and three‐dimensional continua is described. The formulation is based on linear finite elements, permits kinematically admissible velocity discontinuities at all interelement boundaries, and furnishes a kinematically admissible velocity field by solving a non‐linear programming problem. In the latter, the objective function corresponds to the dissipated power (which is minimized) and the unknowns are subject to linear equality constraints as well as linear and non‐linear inequality constraints.Provided the yield surface is convex, the optimization problem generated by the upper bound method is also convex and can be solved efficiently by applying a two‐stage, quasi‐Newton scheme to the corresponding Kuhn–Tucker optimality conditions. A key advantage of this strategy is that its iteration count is largely independent of the mesh size. Since the formulation permits non‐linear constraints on the unknowns, no linearization of the yield surface is necessary and the modelling of three‐dimensional geometries presents no special difficulties.The utility of the proposed upper bound method is illustrated by applying it to a number of two‐ and three‐dimensional boundary value problems. For a variety of two‐dimensional cases, the new scheme is up to two orders of magnitude faster than an equivalent linear programming scheme which uses yield surface linearization. Copyright © 2001 John Wiley & Sons, Ltd.
Improved target volume characterization in stereotactic treatment planning of brain lesions by using high‐resolution BOLD MR‐venography
Authors: Schad Lothar R. 
Published: August 2002

AbstractIn this methodological paper I report the stereotactic correlation of different magnetic resonance imaging (MRI) techniques [MR angiography (MRA), MRI, blood bolus tagging (STAR), functional MRI, and high‐resolution BOLD venography (HRBV)] in patients with cerebral arterio‐venous malformations (AVM) and brain tumors. The patient's head was fixed in a stereotactic localization system which is usable in both MR‐systems and linear accelerator installations. Using phantom measurements global geometric MR image distortions can be ‘corrected’ (reducing displacements to the size of a pixel) by calculations based on modeling the distortion as a fourth‐order two‐dimensional polynomial. Further object‐induced local distortions can be corrected by additionally measured field maps. Using this method multimodality matching could be performed automatically as long as all images are acquired in the same examination and the patient is sufficiently immobilized to allow precise definition of the target volume. Information about the hemodynamics of the AVM was provided by a dynamic MRA with the STAR technique, leading to an improved definition of the size of the nidus, the origin of the feeding arteries, whereas HRBV imaging yielded detailed and improved information about the venous pattern and drainage. In addition, functional MRI was performed in patients with lesions close to the primary motor cortex area, leading to an improved definition of structures at risk for the high‐dose application in radiosurgery. In patients with brain tumors the potential of HRBV to probe tumor angiogenesis and its use in intensity‐modulated treatment planning is still hampered by the open question of how to translate a BOLD signal pattern measured in the tumor to a dose distribution, which should be addressed in future studies. Copyright © 2001 John Wiley & Sons, Ltd.
k‐Broadcasting in trees
Authors: Harutyunyan Hovhannes A. , Liestman Arthur L. 
Published: August 2002

AbstractWe continue the investigation of k‐broadcasting, a variant of broadcasting in which an informed vertex can call up to k of its neighbors in each time unit. We focus on k‐broadcasting in trees. In particular, we asymptotically determine the maximum number of vertices in any tree with given k‐broadcast time and describe the structure of the trees that achieve this maximum. © 2001 John Wiley & Sons, Inc.
The effects of social environment on adult neurogenesis in the female prairie vole
Authors: Fowler Christie D. , Liu Yan , Ouimet Charles , Wang Zuoxin 
Published: August 2002

AbstractIn the mammalian brain, adult neurogenesis has been found to occur primarily in the subventricular zone (SVZ) and dentate gyrus of the hippocampus (DG) and to be influenced by both exogenous and endogenous factors. In the present study, we examined the effects of male exposure or social isolation on neurogenesis in adult female prairie voles (Microtus ochrogaster). Newly proliferated cells labeled by a cell proliferation marker, 5‐bromo‐2′‐deoxyuridine (BrdU), were found in the SVZ and DG, as well as in other brain areas, such as the amygdala, hypothalamus, neocortex, and caudate/putamen. Two days of male exposure significantly increased the number of BrdU‐labeled cells in the amygdala and hypothalamus in comparison to social isolation. Three weeks later, group differences in BrdU labeling generally persisted in the amygdala, whereas in the hypothalamus, the male‐exposed animals had more BrdU‐labeled cells than did the female‐exposed animals. In the SVZ, 2 days of social isolation increased the number of BrdU‐labeled cells compared to female exposure, but this difference was no longer present 3 weeks later. We have also found that the vast majority of the BrdU‐labeled cells contained a neuronal marker, indicating neuronal phenotypes. Finally, group differences in the number of cells undergoing apoptosis were subtle and did not seem to account for the observed differences in BrdU labeling. Together, our data indicate that social environment affects neuron proliferation in a stimulus‐ and site‐specific manner in adult female prairie voles. © 2002 Wiley Periodicals, Inc. J Neurobiol 51: 115–128, 2002