bluuebunny/crossref_metadata_2025_split huggingface dataset:
Binding of CDR‐derived peptides is mechanistically different from that of high‐affinity parental antibodies
Authors: Timmerman Peter , Shochat Susana G. , Desmet Johan , Barderas Rodrigo , Casal Jose Ignacio , Meloen Rob H. , Altschuh Danièle 
Published: October 2010

AbstractWe present data that reveal crucial differences between the binding mode of anti‐gastrin17 (G17, pyroEGPWLEEEEEAYGWMDF‐NH2) monoclonal antibodies (mAbs) and their CDR‐derived synthetic binders (SBs) with G17. The mAbs recognize the N‐terminal sequence of G17 (pyroEGPWL) with nanomolar affinity and high sequence selectivity. Molecular simulations suggest that G17 recognition is based primarily on a multitude of weak antibody–ligand interactions (H‐bonding, van der Waals, etc.) inside a structurally well‐defined cleft‐like binding pocket. Relatively small structural changes (e.g. G‐2 to A for G17) have a drastic impact on affinity, which is characteristic for antibody‐like binding. In contrast, SBs recognize various sequences, including G17‐unrelated targets with affinities of 1:1 complexes estimated in the 0.1–1.0 mM range. In most cases however, the G17/SB complex stoichiometries are not well‐defined, giving rise to multimer aggregate formation with high apparent complex stabilities. Mutational studies on both G17 and SBs reveal the importance of positively charged (K/R) and aromatic residues (W/Y/F) for G17/SB complex formation. We propose that the synthetic binders use combinations of electrostatic, hydrophobic, and/or cation–π interactions in a variety of ways due to their intrinsic flexibility. This may also be the reason for their relatively low target specificity. We speculate that our findings are of general relevance, in showing that high‐affinity mAbs do not necessarily provide the optimal basis for functional mimics design. Copyright © 2010 John Wiley & Sons, Ltd.
Warfarin: an environment‐dependent switchable molecular probe
Authors: Nicholls Ian A. , Karlsson Björn C. G. , Rosengren Annika M. , Henschel Henning 
Published: October 2010

AbstractThe complex nature of the structure of the anticoagulant warfarin is reflected in the diversity of binding modes observed in warfarin–protein recognition systems. A series of theoretical, 1H‐NMR and steady state and time resolved fluorescence spectroscopic studies, have been used to establish correlations between the molecular environment provided by various solvent systems and the relative concentrations of the various members of warfarin's ensemble of isomers. A consequence of these observations is that the judicious choice of solvent system or molecular environment of warfarin allows for manipulation of the position of the equilibrium between isomeric structures such as the hemiacetal and open phenol‐keto forms, the latter even possible in a deprotonated form, where in each case unique spectroscopic properties are exhibited by the respective structures. Collectively, warfarin's capacity to adapt its structure as a function of environment in conjunction with the fluorescence behaviours of the various isomers together provide an environment‐dependent molecular switch with reporter properties, which allows for the simultaneous detection of warfarin in different states with lifetimes spanning the range < 0.10–5.5 ns. These characteristics are here used to examine warfarin binding domains in a series of materials (solvents, protein, inorganic matrix and synthetic polymer). Moreover, these studies demonstrate the potential for using warfarin, or other switchable analogues thereof, as a tool for studying molecular level characteristics, for example local dielectricity. Copyright © 2010 John Wiley & Sons, Ltd.
Extension of the selection of protein chromatography and the rate model to affinity chromatography
Authors: Sandoval G. , Shene C. , Andrews B. A. , Asenjo J. A. 
Published: October 2010

AbstractThe rational selection of optimal protein purification sequences, as well as mathematical models that simulate and allow optimization of chromatographic protein purification processes have been developed for purification procedures such as ion‐exchange, hydrophobic interaction and gel filtration chromatography. This paper investigates the extension of such analysis to affinity chromatography both in the selection of chromatographic processes and in the use of the rate model for mathematical modelling and simulation. Two affinity systems were used: Blue Sepharose and Protein A. The extension of the theory developed previously for ion‐exchange and HIC chromatography to affinity separations is analyzed in this paper. For the selection of operations two algorithms are used. In the first, the value of η, which corresponds to the efficiency (resolution) of the actual chromatography and, Σ, which determines the amount of a particular contaminant eliminated after each separation step, which determines the purity, have to be determined. It was found that the value of both these parameters is not generic for affinity separations but will depend on the type of affinity system used and will have to be determined on a case by case basis. With Blue Sepharose a salt gradient was used and with Protein A, a pH gradient. Parameters were determined with individual proteins and simulations of the protein mixtures were done. This approach allows investigation of chromatographic protein purification in a holistic manner that includes ion‐exchange, HIC, gel filtration and affinity separations for the first time. Copyright © 2010 John Wiley & Sons, Ltd.
Magnetic resonance imaging findings in extrauterine malignant mixed mullerian tumors: Report of two cases
Authors: Yoon Jeong‐Hee , Cho Jeong Yeon , Hwang Sung Il , Lee Hak‐jong , Kim Seung‐Hyup 
Published: October 2010

AbstractThis report describes two cases of women who presented with huge abdominal masses. Those lesions were large, invasive, extrauterine masses, which showed inhomogeneous signal intensities at magnetic resonance image (MRI). After work‐up and surgery, the masses were identified as extremely rare malignant mixed Mullerian tumors that did not originate from the uterus. We have focused on the MRI findings of the tumors, with a review of the literature. J. Magn. Reson. Imaging 2010;32:1238–1241. © 2010 Wiley‐Liss, Inc.
Feasibility and precision of cerebral blood flow and cerebrovascular reactivity MRI measurements using a computer‐controlled gas delivery system in an anesthetised juvenile animal model
Authors: Winter Jeff D. , Fierstra Jorn , Dorner Stephanie , Fisher Joseph A. , Lawrence Keith S. , Kassner Andrea 
Published: October 2010

AbstractPurpose:To demonstrate the feasibility and repeatability of cerebrovascular reactivity (CVR) imaging using a controlled CO2 challenge in mechanically ventilated juvenile pigs.Materials and Methods:Precise end‐tidal partial pressure CO2 (PETCO2) control was achieved via a computer‐controlled model‐driven prospective end‐tidal targeting (MPET) system integrated with mechanical ventilation using a custom‐built secondary breathing circuit. Test‐retest blood‐oxygen level dependent (BOLD) CVR images were collected in nine juvenile pigs by quantifying the BOLD response to iso‐oxic square‐wave PETCO2 changes. For comparison, test‐retest baseline arterial spin labeling (ASL) cerebral blood flow (CBF) images were collected. Repeatability was quantified using the intra‐class correlation coefficient (ICC) and coefficient of variation (CV).Results:The repeatability of the PETCO2 (CV < 2%) step changes resulted in BOLD CVR ICC > 0.94 and CV < 6% for cortical brain regions, which was similar to ASL CBF repeatability (ICC > 0.96 and CV < 4%).Conclusion:This study demonstrates the feasibility and precision of CVR imaging with an MPET CO2 challenge in mechanically ventilated subjects using an animal model. Translation of this method into clinical imaging protocols may enable CVR imaging in young children with cerebrovascular disease who require general anesthesia. J. Magn. Reson. Imaging 2010;32:1068–1075. © 2010 Wiley‐Liss, Inc.
MRI of the neck at 3 Tesla using the periodically rotated overlapping parallel lines with enhanced reconstruction (PROPELLER) (BLADE) sequence compared with T2‐weighted fast spin‐echo sequence
Authors: Ohgiya Yoshimitsu , Suyama Jumpei , Seino Noritaka , Takaya Shu , Kawahara Masaaki , Saiki Makoto , Sai Syouei , Hirose Masanori , Gokan Takehiko 
Published: October 2010

AbstractPurpose:To evaluate motion artifacts, tissue contrasts, and lesion detectability in the neck with the periodically rotated overlapping parallel lines with enhanced reconstruction (PROPELLER) (BLADE) technique.Materials and Methods:A total of 46 patients referred for MRI of the neck were included in a comparison of T2‐weighted BLADE (T2W‐BLADE) sequence and T2W fast spin‐echo (T2W‐FSE) sequence. All examinations were performed at 3T using the same parameters. Two observers evaluated unlabelled images for motion artifacts, the preferred image quality, and lesion detectability. Region of interest (ROI)‐based quantitative measurements were performed to assess tissue contrasts. The frequency of occurrence of the different assessed artifacts and the lesion detectability was tested using McNemar's test. Tissue contrasts were compared using the Wilcoxon paired test. Reader agreement was assessed using kappa test.Results:T2W‐BLADE showed less ghosting and pulsation artifacts than T2W‐FSE (P < 0.01). T2W‐BLADE images were rated as better than or equal to T2W‐FSE images in majority cases (93.5%; kappa = 0.64). There was not significant difference in tissue contrasts between T2W‐BLADE and T2W‐FSE. A total of 32 lesions were present in 32 patients and equally well seen on T2W‐BLADE and T2W‐FSE.Conclusion:T2W‐BLADE can reduce motion artifacts and provide tissue contrasts and lesion detectability equivalent to T2W‐FSE. J. Magn. Reson. Imaging 2010;32:1061–1067. © 2010 Wiley‐Liss, Inc.
Spiral water–fat imaging with integrated off‐resonance correction on a clinical scanner
Authors: Börnert Peter , Koken Peter , Eggers Holger 
Published: October 2010

AbstractPurposeTo integrate water‐fat–resolved spiral gradient‐echo imaging with off‐resonance correction into a clinical MR scanner and to evaluate its basic feasibility and performance.Materials and MethodsThree‐point chemical shift imaging was implemented with forward and strongly T2*‐weighted reverse spiral sampling and with off‐resonance correction after water–fat separation. It was applied in a volunteer study on single breathhold abdominal imaging, which included a brief comparison with Cartesian sampling.ResultsWater‐fat–resolved, off‐resonance–corrected forward and reverse three‐dimensional interleaved spiral imaging was found to be feasible on a clinical MR scanner with only minor changes to the existing data acquisition and reconstruction, and to provide good image quality. Three‐point chemical shift encoded data thus support both, water–fat separation and off‐resonance correction with high accuracy.ConclusionThe combination of chemical shift encoding and appropriate postprocessing could pave the way for water‐fat–resolved spiral imaging in clinical applications. J. Magn. Reson. Imaging 2010;32:1262–1267. © 2010 Wiley‐Liss, Inc.
Acute abdominal pain: Is there a potential role for MRI in the setting of the emergency department in a patient with renal calculi?
Authors: Kalb Bobby , Sharma Puneet , Salman Khalil , Ogan Kenneth , Pattaras John G. , Martin Diego R. 
Published: October 2010

AbstractAcute flank pain is a frequent clinical presentation encountered in emergency departments, and a work‐up for obstructive urolithiasis in this setting is a common indication for computed tomography (CT). However, imaging alternatives to CT for the evaluation of renal colic are warranted in some clinical situations, such as younger patients, pregnancy, patients that have undergone multiple prior CT exams and also patients with vague clinical presentations. MRI, although relatively insensitive for the direct detection of urinary calculi, has the ability to detect the secondary effects of obstructive urolithiasis. Using rapid, single shot T2‐weighted sequences without and with fat saturation provides an abdominopelvic MR examination that can detect the sequelae of clinically active stone disease, in addition to alternate inflammatory processes that may mimic the symptoms of renal colic. In addition, MR nephro‐urography (MRNU) has the ability to provide quantitative analysis of renal function that has the potential to direct clinical management in the setting of obstructing calculi. This review describes the potential utility and limitations of MRI in the emergency setting for diagnosing causes of flank pain and renal colic, particularly in patients with unusual presentations or when an alternative to CT may be warranted. J. Magn. Reson. Imaging 2010;32:1012–1023. © 2010 Wiley‐Liss, Inc.
Combined use of neuroradiology and 1H‐MR spectroscopy may provide an intervention limiting diagnosis of glioblastoma multiforme
Authors: Fellows Greg A. , Wright Alan J. , Sibtain Naomi A. , Rich Phil , Opstad Kirstie S. , McIntyre Dominick J.O. , Bell B. Anthony , Griffiths John R. , Howe Franklyn A. 
Published: October 2010

AbstractPurposeTo evaluate the accuracy of 1H‐MR spectroscopy (1H‐MRS) as an intervention limiting diagnostic tool for glioblastoma multiforme. GBM is the most common and aggressive primary brain tumor, with mean survival under a year. Oncological practice currently requires histopathological diagnosis before radiotherapy.Materials and MethodsEighty‐nine patients had clinical computed tomography (CT) and MR imaging and 1.5T SV SE 1H‐MRS with PRESS localization for neuroradiological diagnosis and tumor classification with spectroscopic and automated pattern recognition analysis (TE 30 ms, TR 2000 ms, spectral width 2500 Hz and 2048 data points, 128–256 signal averages were acquired, depending on voxel size (8 cm3 to 4 cm3). Eighteen patients from a cohort of 89 underwent stereotactic biopsy.ResultsThe 18 stereotactic biopsies revealed 14 GBM, 2 grade II astrocytomas, 1 lymphoma, and 1 anaplastic astrocytoma. All 14 biopsied GBMs were diagnosed as GBM by a protocol combining an individual radiologist and an automated spectral pattern recognition program.ConclusionIn patients undergoing stereotactic biopsy combined neuroradiological and spectroscopic evaluation diagnoses GBM with accuracy that could replace the need for biopsy. We do not advocate the replacement of biopsy in all patients; instead our data suggest a specific intervention limiting role for the use of 1H‐MRS in brain tumor diagnosis. J. Magn. Reson. Imaging 2010;32:1038–1044. © 2010 Wiley‐Liss, Inc.
Prospective comparison of image quality and diagnostic accuracy of 0.5 molar gadobenate dimeglumine and 1.0 molar gadobutrol in contrast‐enhanced run‐off magnetic resonance angiography of the lower extremities
Authors: Achenbach Marina , Figiel Jens H. , Burbelko Mykhaylo , Heverhagen Johannes T. 
Published: October 2010

AbstractPurposeTo compare image quality and diagnostic accuracy of 0.5 molar gadobenate dimeglumine and 1.0 molar gadobutrol in contrast‐enhanced (CE) magnetic resonance angiography (MRA) of the lower extremities interindividually.Materials and MethodsThe study was approved by our Institutional Review Board. Written informed consent was obtained from all patients before enrollment in the study. We prospectively included 74 patients (21 women, 53 men; mean age ± SD: 67.9 ± 11.0 years) with suspected peripheral occlusive vascular disease. All patients underwent a contrast‐enhanced MRA of both lower extremities with either 0.1 mL/kg body weight gadobutrol or gadobenate dimeglumine. Image quality, stenosis grade, and artifacts were assessed by two blinded, independent investigators. Signal intensity (SI), signal‐to‐noise ratio (SNR), and contrast‐to‐noise ratio (CNR) were measured by a third investigator. Contrast agent groups were compared to each other using a two‐sided Student's t‐test.ResultsThe results did not show significant differences for SI, SNR, or CNR. Both investigators were in significant accordance (P < 0.05) with regard to stenosis detection.ConclusionWe conclude that application of standard clinical doses (0.1 mL/kg body weight) of both contrast agents provides similar diagnostic results and gadolinium dose could be reduced by the application of a single dose of gadobenate dimeglumine for CE run‐off MRA. J. Magn. Reson. Imaging 2010;32:1166–1171. © 2010 Wiley‐Liss, Inc.
Distribution of cardiac iron measured by magnetic resonance imaging (MRI)‐R*2
Authors: Yamamura Jin , Grosse Regine , Graessner Joachim , Janka Gritta E. , Adam Gerhard , Fischer Roland 
Published: October 2010

AbstractPurposeTo assess regional iron distribution by magnetic resonance imaging (MRI)‐R2* within the heart of patients with β‐thalassemia major (TM) and other iron overload diseases.Materials and MethodsBreathhold electrocardiogram (ECG)‐gated MRI (1.5 T) of the heart was used for the measurement of transverse relaxation rates R2* in 32 patients (11–79 years). In a mid‐papillary short‐axis slice divided into septal, anterior, lateral, and posterior quadrants, R2* was analyzed from region of interest (ROI)‐based signal intensities from 12 echo times (TE = 1.3–26 msec). Typical boundary effects were evaluated in detail.ResultsThe segmentation of the cardiac wall resulted in highly significant correlations of R2* between septal and all other quadrants. In the patient group with R2* < 50 s−1 (normal), all quadrants show higher normalized median rates (126%–174%) than the septum (P < 10−4), while this was relatively smaller in the group with septal R2* > 50 s−1. Typical boundary effects on segmental R2* from blood, lung tissue, epicardial fat, and hepatic iron could not be easily separated from segmental iron distribution.ConclusionThe measurement of MRI‐R2* in the interventricular septum is the least affected method by boundary effects to detect patients with iron overload at risk of developing heart failure. J. Magn. Reson. Imaging 2010;32:1104–1109. © 2010 Wiley‐Liss, Inc.
Lower brain glutamate is associated with cognitive deficits in HIV patients: A new mechanism for HIV‐associated neurocognitive disorder
Authors: Ernst Thomas , Jiang Caroline S. , Nakama Helenna , Buchthal Steven , Chang Linda 
Published: October 2010

AbstractPurposeTo determine whether subjects with human immunodeficiency virus (HIV)‐associated neurocognitive disorder (HAND) show altered concentrations of brain glutamate (GLU), and whether lower GLU levels correlate with cognitive deficits.Materials and MethodsGLU concentrations were measured in the basal ganglia, frontal gray and white matter, and parietal gray matter of 45 HIV‐positive and 46 age‐and‐education‐matched HIV‐negative subjects using echo‐time averaged proton magnetic resonance spectroscopy (1H MRS).ResultsCompared to controls, HIV subjects with cognitive deficits had lower GLU in the parietal gray matter, while those without cognitive deficits tended to show higher basal ganglia GLU. Lower parietal and frontal gray matter GLU were associated with a greater number of nucleoside reverse transcriptase inhibitors, and were predictive of poorer cognitive performance. Correlations between GLU and cognitive performance, but not the other findings, remained significant after correction for multiple comparisons.ConclusionParietal gray matter GLU is lower in HIV subjects with cognitive deficits. This reduction might result from reduced astrocytic reuptake of GLU, secondary excitotoxicity, and mitochondrial toxicity from antiretroviral treatments. The glutamatergic system may play an important role in the pathophysiology of HAND, and brain GLU on 1H MRS may provide an early surrogate marker for monitoring disease severity and treatment effects. J. Magn. Reson. Imaging 2010;32:1045–1053. © 2010 Wiley‐Liss, Inc.
Faster dynamic imaging of speech with field inhomogeneity corrected spiral fast low angle shot (FLASH) at 3 T
Authors: Sutton Bradley P. , Conway Charles A. , Bae Youkyung , Seethamraju Ravi , Kuehn David P. 
Published: October 2010

AbstractPurposeTo evaluate the impact of magnetic field inhomogeneity correction on achievable imaging speeds for magnetic resonance imaging (MRI) of articulating oropharyngeal structures during speech and to determine if sufficient acquisition speed is available for visualizing speech structures with real‐time MRI.Materials and MethodsWe designed a spiral fast low angle shot (FLASH) sequence that combines several acquisition techniques with an advanced image reconstruction approach that includes magnetic field inhomogeneity correction. A simulation study was performed to examine the interaction between imaging speed, image quality, number of spiral shots, and field inhomogeneity correction. Six volunteer subjects were scanned to demonstrate adequate visualization of articulating structures during simple speech samples.ResultsThe simulation study confirmed that magnetic field inhomogeneity correction improves the available tradeoff between image quality and speed. Our optimized sequence co‐acquires magnetic field maps for image correction and achieves a dynamic imaging rate of 21.4 frames per second, significantly faster than previous studies. Improved visualization of anatomical structures, such as the soft palate, was also seen from the field‐corrected reconstructions in data acquired on volunteer subjects producing simple speech samples.ConclusionAdequate temporal resolution of articulating oropharyngeal structures during speech can be obtained by combining outer volume suppression, multishot spiral imaging, and magnetic field corrected image reconstruction. Correcting for the large, dynamic magnetic field variation in the oropharyngeal cavity improves image quality and allows for higher temporal resolution. J. Magn. Reson. Imaging 2010;32:1228–1237. © 2010 Wiley‐Liss, Inc.
4D time‐resolved magnetic resonance angiography for noninvasive assessment of pulmonary arteriovenous malformations patency
Authors: Boussel Loic , Cernicanu Alexandru , Geerts Liesbeth , Gamondes Delphine , Khouatra Chahera , Cottin Vincent , Revel Didier , Douek Philippe 
Published: October 2010

AbstractPurposeTo assess the capability of four‐dimensional (4D) time‐resolved magnetic resonance angiography (MRA) to assess pulmonary arteriovenous malformations (PAVMs) patency by analyzing pulmonary arterial and venous enhancement kinetics.Materials and MethodsSeven patients with eight documented patent PAVMs underwent a 4D‐MRA with keyhole and viewsharing compression at 3T with the following parameters: spatial resolution 0.87 × 0.87 × 1.4 mm3; field of view 500 × 350 × 238 mm3; dynamic scan time (temporal resolution) 1.2 seconds; total acquisition time 18.1 seconds for six dynamic datasets (6 × 1.2 sec + reference scan: 10.9 sec). All images were reviewed by two experienced radiologists. Image quality was rated on a qualitative 5‐point scale (1: not assessable to 5: excellent). Signal value was measured on cross‐sectional planes for the afferent arteries and efferent veins of the PAVM, and for normal reference healthy arteries and veins. The difference in time to peak for each coupled artery/vein (dTTPav) was calculated and compared with a Mann–Whitney test between PAVMs and reference vessels.ResultsMean image quality was 3.2 ± 0.9. dTTPav was significantly smaller in PAVMs (0.15 ± 0.76 sec) than in reference vessels (3.75 ± 1.62 sec), P < 0.001.Conclusion4D‐MRA is a promising tool for noninvasive assessment of PAVM patency. J. Magn. Reson. Imaging 2010;32:1110–1116. © 2010 Wiley‐Liss, Inc.