bluuebunny/crossref_metadata_2025_split huggingface dataset:
High serum 25-hydroxyvitamin D is associated with a low incidence of stress fractures
Authors: Burgi Alina A , Gorham Edward D , Garland Cedric F , Mohr Sharif B , Garland Frank C , Zeng Kenneth , Thompson Kerry , Lappe Joan M 
Published: June 2011

Abstract
Low serum 25-hydroxyvitamin D [25(OH)D] concentrations are associated with hip fractures, but the dose-response relationship of serum 25(OH)D with risk of stress fractures in young women is unknown. This nested case-control study in a cohort of female Navy recruits was designed to determine whether those with low prediagnostic serum 25(OH)D concentrations had greater risk of stress fracture. Sera were drawn in 2002–2009 from 600 women who were diagnosed subsequently with stress fracture of the tibia or fibula and 600 matched controls who did not experience a stress fracture. The 25(OH)D concentration was measured using the DiaSorin radioimmunoassay method. Controls were individually matched to cases on race (white, black, or other), length of service (±30 days), and day blood was drawn (±2 days). There was approximately half the risk of stress fracture in the top compared with the bottom quintile of serum 25(OH)D concentration (odds ratio [OR] = 0.51, 95% CI 0.34–0.76, p ≤ 0.01). The range of serum 25(OH)D in the lowest quintile was 1.5 to 19.7 (mean 13.9) ng/mL, whereas in the highest it was 39.9 to 112 (mean 49.7) ng/mL. It is concluded that there was a monotonic inverse dose-response gradient between serum 25(OH)D and risk of stress fracture. There was double the risk of stress fractures of the tibia and fibula in women with serum 25(OH)D concentrations of less than 20 ng/mL compared to those with concentrations of 40 ng/mL or greater. A target for prevention of stress fractures would be a serum 25(OH)D concentration of 40 ng/mL or greater, achievable with 4000 IU/d of vitamin D3 supplementation. © 2011 American Society for Bone and Mineral Research
Subperitoneal adenomucinosis following proctocolectomy for ulcerative colitis
Authors: Ryan E. Ronan , Hosseinzadeh Keyanoosh , Bansal Mona , Schraut Wolfgang H. 
Published: June 2011

AbstractAdenomucinosis is a rare condition characterized by accumulation of large volumes of mucin, typically related to mucinous neoplasms of the appendix within the peritoneal space. Extraperitoneal adenomucinosis is an uncommon variant where mucin accumulates outside the peritoneal space and usually arises following surgery for mucinous appendiceal neoplasms. This is a case of subperitoneal adenomucinosis resulting from retention of a small fragment of rectal mucosa following proctocolectomy for ulcerative colitis 16 years prior. The patient presented with a slow‐growing boggy perineal mass. Contrast‐enhanced magnetic resonance imaging (MRI) showed the mass to be localized to the pelvis, without solid enhancing components, and correctly facilitated local surgical excision without the risk of peritoneal dissemination and accurately predicted benignity. J. Magn. Reson. Imaging 2011;. © 2011 Wiley‐Liss, Inc.
Effects of respiratory cycle and body position on quantitative pulmonary perfusion by MRI
Authors: Cao Jie J. , Wang Yi , Schapiro William , McLaughlin Jeannette , Cheng Joshua , Passick Michael , Ngai Nora , Marcus Philip , Reichek Nathaniel 
Published: June 2011

AbstractPurpose:To evaluate the performance of lung perfusion imaging using two‐dimensional (2D) first pass perfusion MRI and a quantitation program based on model‐independent deconvolution algorithm.Materials and Methods:In eight healthy volunteers 2D first pass lung perfusion was imaged in coronal planes using a partial Fourier saturation recovery stead state free precession (SSFP) technique with a temporal resolution of 160 ms per slice acquisition. The dynamic signal in the lung was measured over time and absolute perfusion calculated based on a model‐independent deconvolution program.Results:In the supine position mean pulmonary perfusion was 287 ± 106 mL/min/100 mL during held expiration. It was significantly reduced to 129 ± 68 mL/min/100 mL during held inspiration. Similar differences due to respiration were observed in prone position with lung perfusion much greater during expiration than during inspiration (271 ± 101 versus 99 ± 38 mL/min/100 mL (P < 0.01)). There was a linear increase in pulmonary perfusion from anterior to posterior lung fields in supine position. The perfusion gradient reversed in the prone position with the highest perfusion in anterior lung and the lowest in posterior lung fields.Conclusion:Lung perfusion imaging using a 2D saturation recovery SSFP perfusion MRI coupled with a model‐independent deconvolution algorithm demonstrated physiologically consistent dynamic heterogeneity of lung perfusion distribution. J. Magn. Reson. Imaging 2011;. © 2011 Wiley‐Liss, Inc.
dGEMRIC and subsequent T1 mapping of the hip at 1.5 Tesla: Normative data on zonal and radial distribution in asymptomatic volunteers
Authors: Bittersohl Bernd , Hosalkar Harish S. , Werlen Stefan , Trattnig Siegfried , Siebenrock Klaus A. , Mamisch Tallal C. 
Published: June 2011

AbstractPurpose:To characterize the zonal distribution of three‐dimensional (3D) T1 mapping in the hip joint of asymptomatic adult volunteers.Materials and Methods:This study included 10 volunteers (3 males and 7 females with a mean age of 26.5 years; range, 24–31 years). MRI protocol included standard sequences for hip imaging and a dual‐flip‐angle 3D gradient‐echo (GRE) sequence with volumetric interpolated breathhold examination (VIBE) postcontrast administration. Seven radial cuts were created clockwise around the femoral neck by using multi‐planar reconstruction.Results:Analysis of the radial distribution revealed an increase of T1‐values toward the superior regions. T1‐values differed between the peripheral and central portions. The standard deviation (SD) ranged from 76.2 ms to 124.1 ms in the peripheral zone, and from 69.1 ms to 112.9 ms in the central zone. In both zones, SD was low in the superior regions compared with the anterior and posterior regions of the joint. Based on the high intra‐ (0.95) and interobserver (0.87) agreement, normative data from this study will prepare the foundation for further studies of dGEMRIC and T1 in the hip.Conclusion:We noted a radial T1 mapping pattern with higher values in the superior zone that was not statistically significant and a notable trend in zonal distribution between peripheral and central zones. These findings are critical while outlining future studies for detailed objective evaluation of zonal cartilage lesions due to varying pathologies. J. Magn. Reson. Imaging 2011;. © 2011 Wiley‐Liss, Inc.
Investigation of acupoint specificity by multivariate granger causality analysis from functional MRI data
Authors: Feng Yuanyuan , Bai Lijun , Zhang Wensheng , Xue Ting , Ren Yanshuang , Zhong Chongguang , Wang Hu , You Youbo , Liu Zhenyu , Dai Jianping , Liu Yijun , Tian Jie 
Published: June 2011

AbstractPurpose:To investigate the acupoint specificity by exploring the effective connectivity patterns of the poststimulus resting brain networks modulated by acupuncture at the PC6, with the same meridian acupoint PC7 and different meridian acupoint GB37.Materials and Methods:The functional MRI (fMRI) study was performed in 36 healthy right‐handed subjects receiving acupuncture at three acupoints, respectively. Due to the sustained effects of acupuncture, a novel experimental paradigm using the nonrepeated event‐related (NRER) design was adopted. Psychophysical responses (deqi sensations) were also assessed. Finally, a newly multivariate Granger causality analysis (mGCA) was used to analyze effective connectivity patterns of the resting fMRI data taken following acupuncture at three acupoints.Results:Following acupuncture at PC6, the red nucleus and substantia nigra emerged as central hubs, in comparison with the fusiform gyrus following acupuncture at GB37. Red nucleus was also a target following acupuncture at PC7, but with fewer inputs than those of PC6. In addition, the most important target following acupuncture at PC7 was located at the parahippocampus.Conclusion:Our findings demonstrated that acupuncture at different acupoints may exert heterogeneous modulatory effects on the causal interactions of brain areas during the poststimulus resting state. These preliminary findings provided a clue to elucidate the relatively function‐oriented specificity of acupuncture effects. J. Magn. Reson. Imaging 2011;. © 2011 Wiley‐Liss, Inc.
MRI assessment of iron deposition in multiple sclerosis
Authors: Ropele Stefan , de Graaf Wolter , Khalil Michael , Wattjes Mike P. , Langkammer Christian , Rocca Maria A. , Rovira Alex , Palace Jacqueline , Barkhof Frederik , Filippi Massimo , Fazekas Franz 
Published: June 2011

AbstractIron deposition in the human brain tissue occurs in the process of normal aging and in many neurodegenerative diseases. Elevated iron levels in certain brain regions are also an increasingly recognized finding in multiple sclerosis (MS). The exact mechanism(s) for this phenomenon and its implication in terms of pathophysiology and clinical significance are still largely unknown and debated. Reliable methods to exactly quantify brain iron are a first step to clarify these issues. Therefore, the aim of this review is to present currently available magnetic resonance imaging (MRI) techniques for the assessment of brain iron. These include relaxation time mapping, phase imaging, susceptibility‐weighted imaging, susceptibility mapping, magnetic field correlation imaging, and direct saturation imaging. After discussing their advantages and disadvantages, existing MRI clinical correlations with brain iron concentration in MS are summarized and future research directions are shown. J. Magn. Reson. Imaging 2011;. © 2011 Wiley‐Liss, Inc.
In vivo single scan detection of both iron‐labeled cells and breast cancer metastases in the mouse brain using balanced steady‐state free precession imaging at 1.5 T
Authors: Ribot Emeline J. , Martinez‐Santiesteban Francisco M. , Simedrea Carmen , Steeg Patricia S. , Chambers Ann F. , Rutt Brian K. , Foster Paula J. 
Published: June 2011

AbstractPurpose:To simultaneously detect iron‐labeled cancer cells and brain tumors in vivo in one scan, the balanced steady‐state free precession (b‐SSFP) imaging sequence was optimized at 1.5 T on mice developing brain metastases subsequent to the injection of micron‐sized iron oxide particle‐labeled human breast cancer cells.Materials and Methods:b‐SSFP sequence parameters (repetition time, flip angle, and receiver bandwidth) were varied and the signal‐to‐noise ratio, contrast between the brain and tumors, and the number of detected iron‐labeled cells were evaluated.Results:Optimal b‐SSFP images were acquired with a 26 msec repetition time, 35° flip angle, and bandwidth of ±21 kHz. b‐SSFP images were compared with T2‐weighted 2D fast spin echo (FSE) and 3D spoiled gradient recalled echo (SPGR) images. The mean tumor‐brain contrast‐to‐noise ratio and the ability to detect iron‐labeled cells were the highest in the b‐SSFP images.Conclusion:A single b‐SSFP scan can be used to visualize both iron‐labeled cells and brain metastases. J. Magn. Reson. Imaging 2011;. © 2011 Wiley‐Liss, Inc.
Unenhanced ECG‐gated fast spin‐echo MR digital subtraction angiography (MRDSA) using short echo‐spacing three‐dimensional sequence of femoral arteries: Initial experience
Authors: Morita Satoru , Kojima Shinya , Hirata Masami , Suzuki Masaru , Suzuki Kazufumi , Masukawa Ai , Ueno Eiko 
Published: June 2011

AbstractPurpose:To compare the image qualities of unenhanced electrocardiographically (ECG)‐gated fast spin‐echo magnetic resonance digital subtraction angiography (MRDSA) using a short echo‐spacing three‐dimensional (3D) sequence, known as sampling perfection with application‐optimized contrasts using different flip angle evolutions (SPACE), and the conventional half‐Fourier single‐shot turbo spin‐echo (HASTE) sequence.Materials and Methods:Unenhanced ECG‐gated MRDSA using SPACE and HASTE of the femoral arteries were prospectively acquired in 13 healthy volunteers at 1.5 Tesla (T) MRI. Sequential frontal maximum‐intensity‐projection images produced by subtracting each of 10 systolic images from a diastolic image were evaluated quantitatively using paired t‐test and qualitatively by two blinded radiologists using the Mann‐Whitney U‐test.Results:Quantitatively, relative contrast against the background, contour sharpness index, and slope of the sequential signal changes of the superficial femoral artery of MRDSA using SPACE were significantly better than those of HASTE (P = 0.005, P = 0.001, and P < 0.0001, respectively). Qualitatively, the overall subjective image quality and sequential appearance changes of MRDSA using SPACE were significantly better than those of HASTE (P < 0.0001 and P < 0.0001, respectively).Conclusion:Unenhanced ECG‐gated fast spin‐echo MRDSA using SPACE produces increments in signal intensity, which reflect arterial pulse wave transmission, more clearly than the conventional HASTE sequence. J. Magn. Reson. Imaging 2011;. © 2011 Wiley‐Liss, Inc.
Prostate cancer: Utility of fusion of T2‐weighted and high b‐value diffusion‐weighted images for peripheral zone tumor detection and localization
Authors: Rosenkrantz Andrew B. , Mannelli Lorenzo , Kong Xiangtian , Niver Ben E. , Berkman Douglas S. , Babb James S. , Melamed Jonathan , Taneja Samir S. 
Published: June 2011

AbstractPurpose:To retrospectively assess the utility of fusion of T2‐weighted images (T2WI) and high b‐value diffusion‐weighted images (DWI) for prostate cancer detection and localization.Materials and Methods:In this IRB‐approved HIPAA‐compliant study, 42 patients with prostate cancer underwent MRI including multiplanar T2WI and axial DWI before prostatectomy. Two independent radiologists first assessed multiplanar T2WI and axial DWIb‐1000 images and recorded whether tumor was present in each sextant. Axial T2WI was then fused with axial DWIb‐1000 images, and the radiologists re‐evaluated each sextant for tumor. Accuracy was compared using generalized estimating equations based on a binary logistic regression model.Results:The accuracy, sensitivity, specificity, PPV, and NPV for tumor detection on a sextant‐basis using separate and fused image sets was 65.1%, 50.8%, 78.0%, 67.8%, and 63.6% and 71.0%, 60.8%, 80.3%, 73.7%, and 69.3%, respectively, for reader 1, and 54.0%, 42.5%, 64.4%, 52.0%, and 55.2%, and 61.1%, 56.7%, 65.2%, 59.6%, and 62.3%, respectively, for reader 2. The improvements in accuracy, sensitivity, and NPV using fused images were statistically significant for both readers, as was the improvement in PPV for reader 2 (P ranging from <0.0001 to 0.041). With either separate or fused images, there was greater sensitivity for tumors of higher grade or larger size (P ranging from <0.001 to 0.099).Conclusion:Fusion of T2WI and high b‐value DWI resulted in significant improvements in sensitivity and accuracy for tumor detection on a sextant‐basis, with similar specificity. J. Magn. Reson. Imaging 2011;. © 2011 Wiley‐Liss, Inc.
Measuring lung water: Ex vivo validation of multi‐image gradient echo MRI
Authors: Holverda Sebastiaan , Theilmann Rebecca J. , Sá Rui C. , Arai Tatsuya J. , Hall Evan T. , Dubowitz David J. , Prisk G. Kim , Hopkins Susan R. 
Published: June 2011

AbstractPurpose:To validate a fast gradient echo sequence for rapid (9 s) quantitative imaging of lung water.Materials and Methods:Eleven excised pig lungs were imaged with a fast GRE sequence in triplicate, in the sagittal plane at 2 levels of inflation pressure (5 and 15 cm H2O), an intervention that alters T2*, but not total lung water. Images were acquired alternating between two closely‐spaced echoes and data were fit (voxel‐by‐voxel) to a single exponential to determine T2* and water content, and compared with gravimetric measurements of total water.Results:T2* averaged 1.08 ± 0.02 ms at 5 cm H2O and 1.02 ± 0.02 ms at 15 cm H2O (P < 0.05). The measure was reliable (R2 = 0.99), with an average mean error of 1.8%. There was a significant linear relationship between the two measures of water content: The regression equations for the relationship were y = 0.92x + 19 (R2 = 0.94), and y = 1.04x + 4 (R2 = 0.96), for 5 and 15 cm H2O inflation pressure respectively. Y‐intercepts were not statistically different from zero (P = 0.86).Conclusion:The multi‐echo GRE sequence is a reliable and valid technique to assess water content in the lung. This technique enables rapid assessment of lung water, which is advantageous for in vivo studies. J. Magn. Reson. Imaging 2011;. © 2011 Wiley‐Liss, Inc.
Development of a UHPLC method for the assessment of the metabolic profile of cinitapride
Authors: Marquez Helena , Albertí Joan , Salvà Miquel , Saurina Javier , Sentellas Sonia 
Published: June 2011

AbstractAn ultra high‐performance liquid chromatographic method was developed to study the cinitapride metabolism. Metabolites were generated from the incubation of cinitapride with human liver microsomes. Cinitapride and its metabolites were separated by reversed‐phase mode using a formate aqueous solution (pH 6.5) and acetonitrile as the components of the mobile phase. Chromatographic conditions, including the establishment of an elution gradient, were optimized for obtaining the maximum number of resolved components in the minimum analysis time. Experimental design and multicriteria decision‐making strategies were utilized to facilitate the optimization of chromatographic conditions. Figures of merit were evaluated with cinitapride standards and incubated samples. Limits of detection are about 0.03 μmol/L, and repeatabilities are better than 0.06% for retention times and better than 3.5% for concentrations. The method was applied to characterize the in vitro cinitapride metabolism with human liver microsomes.
Preparation of zwitterionic polymeric monolithic columns for hydrophilic interaction capillary liquid chromatography
Authors: Chen Xin , Tolley H. Dennis , Lee Milton L. 
Published: June 2011

AbstractPorous zwitterionic monolithic columns based on photo‐initiated copolymerization of N,N‐dimethyl‐N‐methacryloxyethyl‐N‐(3‐sulfopropyl)ammonium betaine and poly(ethylene glycol) diacrylate in a binary porogen system comprising isopropanol and decanol were prepared in 75‐μm‐id fused silica capillaries. The resulting monolith was evaluated by hydrophilic interaction chromatography. Inverse size‐exclusion chromatography was used to characterize the pore structure of the resulting monolith. A typical hydrophilic interaction chromatography mechanism was observed when the organic content in the mobile phase was higher than 60%. Good separations of amides, phenols, and benzoic acids were achieved. An efficiency of 75 000 plates/m was obtained. The effects of mobile phase pH, salt concentration, and organic modifier content on retention were investigated. For polar‐charged analytes, both hydrophilic interactions and electrostatic interactions contributed to the selectivity.
Application of pneumatic nebulization single‐drop microextraction for the determination of organophosphorous pesticides by gas chromatography–mass spectrometry
Authors: Wang Yeqiang , Wang Ziming , Zhang Huihui , Shi Yuhua , Ren Ruibing , Zhang Hanqi , Yu Yong 
Published: June 2011

AbstractOrganophosphorous pesticides (OPPs) including dichlorvos, diazinon, malathion, phenamiphos and chlorpyrifos, in water samples were extracted by pneumatic nebulization single‐drop microextraction (PN‐SDME) and then determined by gas chromatography–mass spectrometry (GC‐MS). Experimental parameters affecting the performances of PN‐SDME, such as flow rate of carrier gas, extraction time and microdrop volume, were examined and optimized. The limits of detection for the analytes were in the range of 0.0014–0.0019 μg/mL. The linear range was 0.0050–0.50 μg/mL, except dichlorvos (0.0070–0.50 μg/mL). Water samples were analyzed and the recoveries of the analytes in the spiked water samples were from 75.2 to 105.3%. The relative standard deviations were lower than 12.7%.
Liquid chromatography–electrospray ionization tandem mass spectrometry for the quantification of styraxlignolide A in rat plasma
Authors: Ji Hye Y. , Oh Sei‐Ryang , Lee Hyeong‐Kyu , Na Dong H. , Lee Hye S. 
Published: June 2011

AbstractStyraxlignolide A is a pharmacologically active ingredient isolated from Styrax japonica Sieb. et Zucc. A rapid, selective, and sensitive liquid chromatographic method with electrospray ionization tandem mass spectrometry was developed for use in the quantification of styraxlignolide A in rat plasma. Styraxlignolide A was extracted from rat plasma using ethyl acetate at neutral pH. The analytes were separated on an Atlantis dC18 column using a mixture of methanol and ammonium formate (10 mM, pH 3.0) (70:30, v/v) and detected by tandem mass spectrometry in multiple reaction monitoring mode. The standard curve was linear (r2=0.9978) over the concentration range of 100−10000 ng/mL. The lower limit of quantification was 100 ng/mL using 50 μL of plasma sample. The coefficient of variation and relative error for intra‐ and inter‐assays at four QC levels were 1.6–8.3% and from −12.0 to −1.7%, respectively. The present method was applied successfully to the pharmacokinetic study of styraxlignolide A after intravenous administration of styraxlignolide A at a dose of 10 mg/kg in male Sprague–Dawley rats.
Isometries between Sobolev spaces
Authors: Biegert Markus , Nittka Robin 
Published: June 2011

AbstractLet Ω1 and Ω2 be bounded, connected open sets in \documentclass{article}\usepackage{amssymb}\begin{document}\pagestyle{empty}$\mathbb {R}^N$\end{document} with continuous boundary, and let p > 2. We show that every positive linear isometry T from W1, p(Ω1) to W1, p(Ω2) that satisfies \documentclass{article}\usepackage{amssymb}\begin{document}\pagestyle{empty}$W^{1,p}_0(\Omega _2) \subset TW^{1,p}_0(\Omega _1)$\end{document} corresponds to a rigid motion of the space, i.e., Tu = u○ξ for an isometry ξ of \documentclass{article}\usepackage{amssymb}\begin{document}\pagestyle{empty}$\mathbb {R}^N$\end{document}, and more precisely ξ(Ω2) = Ω1. We also prove similar results for less regular domains, and we obtain partial results also for p = 2.
Peptide and protein drugs: The study of their metabolism and catabolism by mass spectrometry
Authors: Katsila Theodora , Siskos Alexandros P. , Tamvakopoulos Constantin 
Published: June 2011

AbstractPeptide and protein drugs have evolved in recent years into mainstream therapeutics, representing a significant portion of the pharmaceutical market. Peptides and proteins exhibit highly diverse structures, broad biological activities as hormones, neurotransmitters, structural proteins, metabolic modulators and therefore have a significant role as both therapeutics and biomarkers. Understanding the metabolism of synthetic or biotechnologically derived peptide and protein drugs is critical for pharmaceutical development as metabolism has a significant impact on drug efficacy and safety. Although the same principles of pharmacokinetics and metabolism of small molecule drugs apply to peptide and protein drugs, there are few notable differences. Moreover, the study of peptide and protein drug metabolism is a rather complicated process which requires sophisticated analytical techniques, and mass spectrometry based approaches have provided the capabilities for efficient and reliable quantification, characterization, and metabolite identification. This review article will focus on the current use of mass spectrometry for the study of the metabolism of peptide and protein drugs. © 2011 Wiley Periodicals, Inc., Mass Spec Rev 31:110–133, 2012