bluuebunny/crossref_metadata_2025_split huggingface dataset:
Future directions for the analysis of musculoskeletal design and locomotor performance
Authors: Biewener Andrew A. 
Published: August 2002

AbstractNew techniques and conceptual frameworks offer new challenges and exciting opportunities for research on the biomechanics and physiology of vertebrate musculoskeletal design and locomotor performance. Past research based on electromyography and two‐dimensional kinematics has greatly advanced the field of vertebrate functional morphology. Studies using these approaches have revealed much about vertebrate structure and function and have emphasized the importance of incorporating historical and developmental constraint and ecological context. Continued use of these experimental tools, but with greater emphasis on three‐dimensional analysis of body movement, in combination with 3D kinetics and flow visualization of fluid movement past moving organisms, can now take advantage of the considerable advances in computing power and digital video technology. Indeed, surprisingly few detailed 3D analyses of movement for many locomotor modes and differing organisms are presently available. A challenge of 3D analyses will be to reduce the complexity of the data obtained in order to identify general principles of movement and biomechanics. New techniques and approaches for measuring muscle forces and length changes, together with activation patterns and movement, under dynamic conditions of more varied motor behavior are now also available. These provide the opportunity to study the mechanics and physiology of muscle function at greater depth and under more realistic conditions than has been previously possible. The importance of studying intact, behaving organisms under a broader range of locomotor conditions (other than steady state) and in the context of their natural environment remains a critical need for vertebrate biologists. This provides the much‐needed opportunity for placing advances at more cellular and molecular levels into the context of whole organism function. Hence, studies at the organismal level remain paramount. J. Morphol. 252:38–51, 2002. © 2002 Wiley‐Liss, Inc.
Transverse masticatory movements, occlusal orientation, and symphyseal fusion in selenodont artiodactyls
Authors: Hogue Aaron S. , Ravosa Matthew J. 
Published: August 2002

AbstractBased on extensive experimental work on primates, two masticatory loading regimes have emerged as the likely determinants of mandibular symphyseal fusion—dorsoventral shear and lateral transverse bending (wishboning) (Ravosa and Hylander, 1994; Hylander et al., 1998, 2000). Recently, however, it has been argued that, rather than functioning to strengthen the symphysis during mastication, fusion serves to stiffen the symphyseal joint so as to facilitate increased transverse jaw movements during occlusion (Lieberman and Crompton, 2000). As part of this transverse stiffness model, it has been suggested that taxa with fused symphyses should also exhibit more horizontally oriented occlusal wear facets. Using a series of univariate and bivariate analyses, we test predictions of these three models in a sample of 44 species of selenodont artiodactyls. Consistent with the wishboning and transverse stiffness models, taxa with fused symphyses (camelids) have more horizontally oriented M2 and M2 occlusal wear facets, anteroposteriorly (AP) elongate symphyses, and relatively wider corpora. Contrary to the dorsoventral shear model, camelids do not have relatively deeper corpora (due to greater parasagittal bending). While taxa with ossified symphyses have relatively larger symphysis cross‐sectional areas, this appears to be the byproduct of an increase in AP symphysis length due to greater lateral transverse bending of the mandible. Theoretical consideration of the biomechanics of mastication further suggests that strength, not stiffness, is the critical factor in determining symphyseal ossification. Thus, like anthropoid primates, fusion in selenodont artiodactyls appears to function in resisting increased wishboning stresses arising from an emphasis on transverse occlusal/mandibular movements and loads. J. Morphol. 249:221–241, 2001. © 2001 Wiley‐Liss, Inc.
The sensory epithelium of the tentacles and the rhinophore of Nautilus pompilius L. (cephalopoda, nautiloidea)
Authors: Ruth Peter , Schmidtberg Henrike , Westermann Bettina , Schipp Rudolf 
Published: August 2002

AbstractNine intraepithelial ciliated cell types that are presumed to be sensory cells were identified in the epithelium of the pre‐ and postocular tentacles, the digital tentacles, and the rhinophore of the juvenile tetrabranchiate cephalopod Nautilus pompilius L. The morphological diversity and specialization in distribution of the different ciliated cell types analyzed by SEM methods suggest that these cells include receptors of several sensory functions. Ciliated cell types in different organs that show similar surface features were combined in named groups. The most striking cell, type I, is characterized by a tuft of long and numerous cilia. The highest density of this cell type occurs in ciliary fields in the epithelium of the lamellae of the pre‐ and postocular tentacles, in the olfactory pits of the rhinophores, and in the lamellae of four pairs of lateral digital tentacles, but not in the epithelium of the medial digital tentacles. The similar morphological data, together with behavioral observations on feeding habits, suggest that this cell type may serve in long‐distance chemosensory function. The other ciliated cell types are solitary cells with specific spatial distributions in the various organs. Cell types with tufts of relatively short, stiff cilia (types III, IV, VIII), which are distributed in the lateral and aboral areas of the tentacles and at the base of the tentacle‐like process of the rhinophore, are considered to be employed in mechanosensory transduction, while the solitary cells with bristle‐like cilia at the margin of the ciliary fields (type II) and at the base of the rhinophore (type IX) may be involved in chemoreception. Histological investigation of the epithelium and the nerve structures of the different organs shows the proportion and distribution of the sensory pathways.Two different types of digital tentacles can be distinguished according to their putative functions: lateral slender digital tentacles in four pairs, of which the lowermost are the so‐called long digital tentacles, participate in distance chemoreception, and the medial digital tentacles, whose terminal axial nerve cord may represent a specialized neuromechanosensory structure, appear to have contact chemoreceptive abilities. J. Morphol. 251:239–255, 2002. © 2002 Wiley‐Liss, Inc.
Reproducibility of in vivo metabolite quantification with proton magnetic resonance spectroscopic imaging
Authors: Chard Declan T. , McLean Mary A. , Parker Geoffrey J.M. , MacManus David G. , Miller David H. 
Published: August 2002

AbstractPurposeTo investigate intra‐ and interscanner in vivo reproducibility of brain metabolite quantification using 1H magnetic resonance spectroscopic imaging (1H‐MRSI) (PRESS localization, TE = 30 msec, voxel volume = 2.3 mL) and the linear combination model (LCModel).Materials and MethodsOne subject had a total of nine scans on three occasions at a single site, and three subjects had single scans at two sites. Coefficients of variation (CVs) were estimated using different statistical models applied to intra‐ and interscanner data; therefore, only qualitative comparisons may be made between results.ResultsCV (intra‐/interscanner) for metabolite quantifications were choline, 12.3%/10.1%; creatine, 9.9%/10.6%; glutamate + glutamine, 15.8%/13.6%; myo‐inositol, 18.5%/14.7%; and N‐acetyl‐aspartate + N‐acetyl‐aspartyl‐glutamate, 6.1%/7.0%. Overall, total intra‐ and intersubject variability was greater than intra‐ and interscanner variability.ConclusionWhen quantifying metabolic concentrations using the methods employed in this study, biological factors contribute a greater proportion to measurement variability than measurement errors. Using this technique, intra‐ and intersite measurement errors are of the same order. J. Magn. Reson. Imaging 2002;15:219–225. © 2002 Wiley‐Liss, Inc.
Biological dosimetry of magnetic resonance imaging
Authors: Guisasola Concepción , Desco Manuel , Millán Olga , Villanueva Francisco J. , García‐Barreno Pedro 
Published: August 2002

AbstractPurposeTo check the bioeffects of the components of magnetic resonance imaging (MRI). MRI is based on an assumedly harmless interaction between certain nuclei in the body when placed in a strong magnetic field and radio wave fields. There are three key factors actuating on the examining body: a powerful static magnetic field (SMF), magnetic gradient fields (MGFs), and pulsed radiofrequency (RF) radiation.Materials and MethodsIn vitro cells (L‐132 cells) were used as biosensors, and different cellular compounds were used as biomarkers (heat shock proteins [HSPs] and their messenger ribonucleic acids [mRNAs], calcium, and adenosine‐3′,5′‐cyclic monophosphate [cAMP]). The biosensors were placed in the bore of a 1.5‐T MRI machine and the different electromagnetic fields were operated.ResultsHSPs and their mRNAs and cAMP did not respond to SMF, MGFs, or RF radiation. RF radiation increased cytosolic calcium concentration (18%, P < 0.05).ConclusionAlthough MRI procedures do not induce any cellular stress response, it may cause an unfathomable calcium increase in vitro. Although the in vitro experimental conditions are not totally comparable to clinical situations, the usefulness of the in vivo biological dosimetry, circulating leukocytes as biosensors, and HSPs and/or calcium as biomarkers is suggested. J. Magn. Reson. Imaging 2002;15:584–590. © 2002 Wiley‐Liss, Inc.
Analysis of subtraction methods in three‐dimensional contrast‐enhanced peripheral MR angiography
Authors: Huang Yuexi , Webster Christie A. , Wright Graham A. 
Published: August 2002

AbstractPurposeTo compare the effectiveness of three image subtraction algorithms designed to improve arterial conspicuity in first‐pass contrast‐enhanced magnetic resonance (MR) angiography.Materials and MethodsThree subtraction methods were analyzed through computer simulations, phantom studies, and clinical studies. These algorithms were: complex subtraction, magnitude subtraction, and maximum intensity projection subtraction.ResultsIn high resolution three‐dimensional imaging, maximum intensity projection subtraction generally yields the best background suppression. Complex subtraction is effective in reducing partial volume effects in low resolution imaging. Magnitude subtraction works better in high resolution, low contrast concentration protocols.ConclusionChoosing the appropriate subtraction method according to the protocol is helpful in optimizing image quality. J. Magn. Reson. Imaging 2002;15:541–550. © 2002 Wiley‐Liss, Inc.
Myocardial flow reserve parametric map, assessed by first‐pass MRI compartmental analysis at the chronic stage of infarction
Authors: Germain Philippe , Roul Gérald , Baruthio Joseph , Jahn Christine , Coulbois Paul M. , Dumitresco Barbu , Dietemann Jean L. , Bareiss Pierre , Constantinesco A. 
Published: August 2002

AbstractRegional myocardial flow and flow reserve (MFR) were assessed by compartmental analysis of Gd‐enhanced MRI first‐pass data in 7 patients with atypical chest pain, and in 15 patients with previous transmural myocardial infarction. The FE product (Flow × Extraction coefficient), derived from the modified Kety equation, was measured in regions corresponding to the Tetrofosmine‐SPECT fixed defect and in remote normal regions. The FE product at rest and hyperemic FE product were similar in healed revascularized tissues (70.5 ± 15.6 and 112.5 ± 19.5ml/mn/100g, respectively) and in normal myocardium (76.2 ± 18.3 and 142.2 ± 33.0, respectively). In contrast, the FE index (48.8 ± 15.2 and 60.7 ± 18.0, respectively, P < 0.01 versus the two previous groups) and the MFR (1.27 ± 0.20 vs. 1.91 ± 0.29 in normal regions) were reduced in healed fibrotic tissues when the infarct‐related artery remained occluded. Myocardial flow reserve maps allowed correct identification of regions corresponding to an occluded infarct‐related artery. J. Magn. Reson. Imaging 2001;13:352–360. © 2001 Wiley‐Liss, Inc.
Mass spectrometric analysis of recombinant adenylate cyclase toxin from Bordetella pertussis strain 18323/pHSP9
Authors: Havlícek Vladimír , Higgins LeeAnn , Chen Weibin , Halada Petr , Sěbo Peter , Sakamoto Hiroshi , Hackett Murray 
Published: August 2002

AbstractThe adenylate cyclase toxin–hemolysin (ACT) is a key virulence factor of the whooping cough agent Bordetella pertussis (Bp). The major cytotoxic activity of this 1706‐residue protein consists of its capacity to invade a variety of eukaryotic cells directly across their cytoplasmic membrane and to deliver into cells a catalytic adenylate cyclase domain. This causes impairment of immune effector cells and apoptosis of lung macrophages by uncontrolled conversion of ATP to cAMP. The adenylate cyclase toxin–hemolysin acquires biological activity upon post‐translational amide‐linked palmitoylation of the ϵ‐amino group of lysine 983 (K983) by the accessory fatty acyltransferase, CyaC. However, an additional conserved acylation site can be identified in ACT at lysine 860 (K860) and this residue is palmitoylated when recombinant ACT is produced in Escherichia coli (r‐Ec‐ACT). In this paper we report the double acylation of r‐Bp‐ACT secreted by a recombinant Bp strain 18323/pHSP9. This strain overproduces ACT from an oligocopy plasmid carrying the entire cya locus of Bordetella pertussis 18323. Palmitoylation of both conserved lysines (K860 and K983) of r‐Bp‐ACT expressed by this Bp strain was found. In addition, an error in the deduced protein sequence was identified, with Leu being the real residue at position 1001 and not the Val residue given in the published gene sequence. We also discuss these results in comparison with those from recombinant ACT expressed in E. coli strain K12 XL1‐Blue. The analytical approach for characterization of the fatty acylation of ACT from strain 18323/pHSP9 consisted of multiple proteolytic digestion procedures (trypsin, Asp‐N), microcapillary liquid chromatography/tandem mass spectrometry and matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry. Copyright © 2001 John Wiley & Sons, Ltd.
Electron ionization mass spectra of 3,4‐disubstituted‐1,2,4‐oxa(thia)diazole‐5(4H)‐thione(ones). Substituent effects on the mass spectrometric rearrangement of 3‐aryl‐4‐(p‐tolyl)‐1,2,4‐oxadiazole‐5(4H)‐thiones to the corresponding oxo compounds
Authors: Pihlaja Kalevi , Agirbas Hikmet , Valtamo Pauliina 
Published: August 2002

AbstractThe fragmentation behaviour of ten 3,4‐disubstituted 1,2,4‐oxadiazole‐5(4H)‐thiones and seven 3,4‐disubstituted 1,2,4‐thiadiazole‐5(4H)‐ones studied here confirmed the earlier observations about the partial rearrangement of the former after ionization into the latter before further fragmentation. In the case of eight 3‐(substituted phenyl)‐4‐(p‐tolyl)‐1,2,4‐oxadiazole‐5(4H)‐thiones the fragmentations reflecting the above‐mentioned molecular ion rearrangement show a clear correlation on the substituent σ values. The electron‐withdrawing substituents destabilize the molecular ion, so higher amounts of the rearranged ion [R1NCO]+· are obtained. A good correlation of log[R1NCO]+ against σ was obtained (r = 0.96). Only a satisfactory correlation prevailed for log([R1NCO]+·/[R1NCS]+·) against σ(r = 0.87). Copyright © 2001 John Wiley & Sons, Ltd.
Acetate, propionate and butyrate in plasma: determination of the concentration and isotopic enrichment by gas chromatography/mass spectrometry with positive chemical ionization
Authors: Pouteau Etienne , Meirim Isabelle , Métairon Sylviane , Fay Laurent‐Bernard 
Published: August 2002

AbstractThis study describes a rapid and simple method to determine short‐chain fatty acid (SCFA) concentrations and their isotopic enrichments (M0 + 1 and M0 + 2) in human plasma. Sample preparation involves SCFA extraction and derivatization with 1‐(tert‐butyldimethylsilyl)imidazole. Gas chromatography/mass spectrometry was performed using chemical ionization with ammonia as the reagent gas. Outstanding resolution, excellent linearity and good detection limits were obtained. Inter‐assay and intra‐assay repeatability was below 10% and 3% respectively for SCFA concentration. Inter‐assay repeatability was below 5%, 4%, 6%, and 14% for isotopic enrichment determination of [1‐13C]acetate and [1,2‐13C2]acetate, [1‐13C]propionate and [1‐13C]butyrate respectively, with intra‐assay being below 6%. Such SCFA concentrations and isotopic enrichments were determined in the plasma of rats infused with a 13C‐labeled SCFA. The turnovers of acetate, propionate and butyrate in rats were 19 µmol kg−1 min−1, 2.6 µmol kg−1 min−1, 0.3 µmol kg−1 min−1 respectively. Copyright © 2001 John Wiley & Sons, Ltd.
Environmental applications of membrane introduction mass spectrometry
Authors: Ketola Raimo A. , Kotiaho Tapio , Cisper Mary E. , Allen Todd M. 
Published: August 2002

AbstractThe purpose of this review is to highlight the versatility of membrane introduction mass spectrometry (MIMS) in environmental applications, summarize the measurements of environmental volatile organic compounds (VOCs) accomplished using MIMS, present developments in the detection of semi‐volatile organic compounds (SVOCs) and forecast possible future directions of MIMS in environmental applications. Copyright © 2002 John Wiley & Sons, Ltd.
Subcellular localisation of the X protein in HBV infected hepatocytes
Authors: Hoare Jonathan , Henkler Frank , Dowling Jason J. , Errington William , Goldin Robert D. , Fish David , McGarvey Michael J. 
Published: August 2002

AbstractHepatitis B virus X protein (HBx) is a multifunctional protein that exerts its effects primarily by acting as a transcriptional transactivator of viral and multiple host cell genes. HBx is thought to be essential for maintaining viral replication and has been implicated in the development of hepatocellular carcinoma in patients chronically infected with hepatitis B virus. Very little is known about its functional mechanisms and although interactions with several nuclear and cytoplasmic proteins have been demonstrated in vitro, there is no clear consensus as to where HBx localises in infected hepatocytes. In this study, the expression and intracellular distribution of HBx were examined in human liver biopsies using an anti‐HBx rabbit polyclonal antiserum. HBx was detected in a high proportion (69%) of samples from patients with chronic HBV infection. Detection of HBx correlated with the absence of cirrhosis and the presence of serum e‐antigen. HBx was detected predominantly in the cytoplasm; however, it was also found in the nuclei of up to 20% of positively stained hepatocytes, either exclusively nuclear or localised both in the nucleus and cytoplasm within the same cell. Furthermore, the intracellular distribution of HBx was analysed in transfected Huh‐7 cells by confocal microscopy, using the monoclonal antibody 16F1. In these experiments, a substantial nuclear detection was confirmed in a significant proportion of HBx expressing cells. The data indicate a high functional significance of nuclear HBx, consistent with the concept that transactivation may involve interactions with nuclear proteins. J. Med. Virol. 64:419–426, 2001. © 2001 Wiley‐Liss, Inc.
An antigen fragment encompassing the AD2 domains of glycoprotein B from two different strains is sufficient for differentiation of primary vs. recurrent human cytomegalovirus infection by ELISA
Authors: Rothe Markus , Pepperl‐Klindworth Sandra , Lang Dieter , Vornhagen Rolf , Hinderer Walter , Weise Kerstin , Sonneborn Hans‐H. , Plachter Bodo 
Published: August 2002

AbstractPrimary human cytomegalovirus (HCMV) infection during pregnancy is a frequent cause of fatal damage in populations with low prevalence of HCMV. Differentiation of primary vs. recurrent HCMV infection is an important issue in prenatal counseling. Antibodies specific for viral glycoproteins become detectable only with considerable delay with relation to HCMV infection or IgG seroconversion. Thus, lack of glycoprotein specific (gp‐specific) antibodies can serve as a convenient indicator to identify those pregnant women that bear an elevated risk for HCMV transplacental transmission and fetal sequelae. In the opposite case, presence of gp‐specific antibodies virtually excludes HCMV primary infection several weeks before sampling. However, no standardized screening assay for HCMV gp‐specific antibodies had been available thus far. For this reason, an ELISA based on procaryotically expressed fragments of HCMV glycoprotein B (gB; gpUL55) was developed. Small fragments of gB from two different laboratory strains, encompassing the antigenic domain 2 (AD2) sufficed for sensitive and specific detection of gp‐specific antibodies. The gB‐ELISA titers correlated with titers of virus neutralizing antibodies in serum samples from primary or recurrent HCMV infections. Seroconversion kinetics of the gB‐ELISA in samples from patients with primary HCMV infection closely paralleled the delay in seroconversion of gp‐specific antibodies as determined by neutralization assay. Thus this assay provides a diagnostic tool that is easy to perform and can significantly add to available methods for the timely identification of primary HCMV infection during pregnancy. In addition, the gB‐ELISA may be helpful in other clinical settings for the differentiation of primary HCMV infection from diseases caused by other pathogens. J. Med. Virol. 65:719–729, 2001. © 2001 Wiley‐Liss, Inc.
A novel method for determination of the maximum stable feedback level in laser diodes
Authors: Pierce Iestyn , Rees Paul , Spencer Paul S. , Alan Shore K. 
Published: August 2002

AbstractA simple method is presented for determining the minimum feedback level required for the onset of instability and chaos in semiconductor laser diodes. Using this method, the positions of the pair of dominant system poles in the s‐plane are found for varying levels of feedback. This analysis determines the feedback level required to send the system unstable. The results are applicable for both long and short external cavities. The method is ideally suited to the prediction of system stability from measurements of microwave modulation response or relative intensity noise (RIN) spectrum, since it only requires knowledge of the natural frequency and damping frequency of the dominant s‐plane poles of the laser diode without optical feedback. Copyright © 2001 John Wiley & Sons, Ltd.