bluuebunny/crossref_metadata_2025_split huggingface dataset:
Dynamic contrast‐enhanced magnetic resonance imaging as a surrogate marker of tumor response to anti‐angiogenic therapy in a xenograft model of glioblastoma multiforme
Authors: Gossmann Axel , Helbich Thomas H. , Kuriyama Nagato , Ostrowitzki S. , Roberts Timothy P.L. , Shames David M. , van Bruggen N. , Wendland Michael F. , Israel Mark A. , Brasch Robert C. 
Published: August 2002

AbstractPurposeTo evaluate the effects of a neutralizing anti‐vascular endothelial growth factor (anti‐VEGF) antibody on tumor microvascular permeability, a proposed indicator of angiogenesis, and tumor growth in a rodent malignant glioma model.Materials and MethodsA dynamic contrast‐enhanced magnetic resonance imaging (MRI) technique, permitting noninvasive in vivo and in situ assessment of potential therapeutic effects, was used to measure tumor microvascular characteristics and volumes. U‐87, a cell line derived from a human glioblastoma multiforme, was implanted orthotopically into brains of athymic homozygous nude rats.ResultsTreatment with the monoclonal antibody A4.6.1, specific for VEGF, significantly inhibited tumor microvascular permeability (6.1 ± 3.6 mL min–1100 cc–1), compared to the control, saline‐treated tumors (28.6 ± 8.6 mL min–1100 cc–1), and significantly suppressed tumor growth (P < .05).ConclusionFindings demonstrate that tumor vascular permeability and tumor growth can be inhibited by neutralization of endogenous VEGF and suggest that angiogenesis with the maintenance of endothelial hyperpermeability requires the presence of VEGF within the tissue microenvironment. Changes in tumor vessel permeability and tumor volumes as measured by contrast‐enhanced MRI provide an assay that could prove useful for clinical monitoring of anti‐angiogenic therapies in brain tumors. J. Magn. Reson. Imaging 2002;15:233–240. © 2002 Wiley‐Liss, Inc.
Intracranial oscillations of cerebrospinal fluid and blood flows: Analysis with magnetic resonance imaging
Authors: Strik Claudia , Klose Uwe , Erb Michael , Strik Herwig , Grodd Wolfgang 
Published: August 2002

AbstractPurposeTo detect oscillations of the cerebrospinal fluid (CSF) flow related to the heartbeat and frequencies lower than 0.6 Hz and to compare these oscillations of CSF and blood flow in cerebral vessels by using echo planar imaging in real time mode. The existence of such waves has been well known but has not yet been shown by MRI.Materials and MethodsIn a slice perpendicular to the aqueduct, CSF flow as well as CBF, could be determined in sagittal sinus, basilar artery, and capillary vessels. After Fourier analysis, four frequency bands were assigned.ResultsIn the very high‐frequency (heart rate) range, the integrals under the CSF curves were more closely related to arterial CBF than to changes in the sinus. Also, in the high‐frequency (respiration rate), low‐frequency (0.05–0.15 Hz), and very‐low‐frequency (0.008–0.05 Hz) ranges, the integrals under the CSF curves corresponded with arterial and capillary CBF.ConclusionSlow and fast oscillations in CSF flow are detectable in healthy persons with a proportional allotment to arterial and capillary CBF. J. Magn. Reson. Imaging 2002;15:251–258. © 2002 Wiley‐Liss, Inc.
Simultaneously monitoring both T1 and T2* signal intensities on a bolus injection of Gd‐DTPA may distinguish infarcted myocardium
Authors: Mark John , Dai Guangping , Xiang Bo , Sun Jiankang , Lazarow Normand , Lindsay William G. , Corne Robert , Deslauriers Roxanne , Tian Ganghong 
Published: August 2002

AbstractPurpose:To determine whether injured myocardium may be identified by simultaneously monitoring contrast‐induced T1 and T2* signal intensity time‐course changes with an interleaved T1‐T2* imaging sequence.Materials and Methods:Gadolinium‐diethylene triamine pentaacetic acid (0.05 mmol/ kg) was injected as a bolus into ex vivo pig hearts, and simultaneous T1 and T2* time‐courses were obtained during the first pass.Results:Observing contrast‐enhanced R1 or R2* rates (1/T1 or 1/T2* times, respectively) early after contrast injection did not fully differentiate viable from nonviable myocardium. T2* recovery at maximal T1 signal intensity, measured using simultaneous T1 and T2* imaging, displayed a significantly different percentage recovery (P < 0.05) among normal (30.5 ± 2.4% of baseline value), reperfused infarcted (63 ± 7.2%), and low‐reflow infarcted (90 ± 2.8%) myocardium.Conclusion:Simultaneously monitoring both T1 and T2* signal intensities may help in the assessment of myocardial injury. J. Magn. Reson. Imaging 2002;15:532–540. © 2002 Wiley‐Liss, Inc.
Chronic hepatitis: Correlation of early patchy and late linear enhancement patterns on gadolinium‐enhanced MR images with histopathology initial experience
Authors: Semelka Richard C. , Chung Jae‐Joon , Hussain Shahid M. , Marcos Hani B. , Woosley John T. 
Published: August 2002

AbstractThe purposes of our study were to describe the early and late enhancement patterns of the liver on gadolinium‐enhanced dynamic magnetic resonance (MR) images in patients with chronic hepatitis and to correlate these findings with histopathology. Patients were entered into the study based on the presence of chronic hepatitis, imaging evaluation with MR imaging (MRI), including early and late postgadolinium images, and histopathologic correlation. Early and late dynamic postgadolinium MR images of 29 consecutive patients with a pathologically proven diagnosis of chronic hepatitis were retrospectively evaluated for the presence of three types of enhancement, i.e., homogeneous, linear, and patchy. Correlation was made between the enhancement patterns on MR images and blinded retrospective interpretation of the histopathologic specimens, which were obtained within 3 months of the MR examination. Of the 29 patients, 16 (55.2%) patients showed patchy enhancement on the early gadolinium‐enhanced MR images. In 11 (68.8%) of these 16 patients, histopathology demonstrated numerous macrophages, variable hepatocyte necrosis, and increased steatosis. The remaining 13 (44.8%) patients showed homogeneous enhancement on the early gadolinium‐enhanced MR images. In 11 (84.6%) of these 13 patients, histopathology demonstrated few or no macrophages, little or no hepatocellular necrosis, and little or no steatosis. The correlation between patchy enhancement and acute liver inflammation was significant (P= 0.005). On the late gadolinium‐enhanced MR images, 20 (69.0%) of 29 patients showed prominent linear enhancement. In 19 (95.0%) of these 20 patients, histopathology revealed hepatic fibrosis. We concluded that in patients with chronic hepatitis, the presence of early patchy enhancement indicates either concurrent or recent hepatocellular damage, whereas the presence of late linear enhancement indicates the presence of fibrosis, with a high degree of correlation with histopathologic findings. J. Magn. Reson. Imaging 2001;13:385–391. © 2001 Wiley‐Liss, Inc.
Proton magnetic resonance spectroscopic imaging reveals differences in spinocerebellar ataxia types 2 and 6
Authors: Boesch S.M. , Schocke M. , Bürk K. , Hollosi P. , Fornai F. , Aichner F.T. , Poewe W. , Felber S. 
Published: August 2002

AbstractThe objective of this study was to investigate cerebellar metabolism in patients with autosomal dominant cerebellar ataxia type 1 (ADCA‐I) carrying two distinct mutations of spinocerebellar ataxia (SCA). Non‐invasive image‐guided proton magnetic resonance spectroscopy imaging (1H‐MRSI) was performed in 4 patients with SCA2, and 3 patients carrying the SCA6 mutation. For MRSI, we employed a spin‐echo sequence (TR = 1500 msec, TE = 135 msec, slice thickness = 15 mm, FOV = 240 mm) and a stimulated‐echo sequence (TR = 1500 msec, TE = 20 msec, slice thickness = 15 mm, FOV = 240 mm). Measures included the peak integral ratios of neuronal and glial markers [N‐acetylaspartate (NA) to creatine (Cr), choline‐containing compounds (CHO) to Cr, and lactate (LAC) to Cr]. We found NA:Cr ratios were significantly lower in patients with SCA2 (40.4% lower) compared to patients carrying the SCA6 mutation. CHO:Cr ratios differed between the two mutations using short echo time (30.8% lower in SCA2), but not when applying long echo time 1H‐MRSI. Measurements using long echo time revealed LAC peaks in all SCA2 patients. 1H‐MRSI revealed metabolic differences between SCA2 and SCA6 patients. NA:Cr ratios were significantly lower in patients with the SCA2 mutation compared to the SCA6 mutation, and LAC signals were obtained in the cerebella of SCA2 patients. In addition, CHO:Cr ratios showed different behavior using short and long TE, indicating differences in relaxation times of choline compounds in SCA2. J. Magn. Reson. Imaging 2001;13:553–559. © 2001 Wiley‐Liss, Inc.
Relationship between bone marrow cellularity and apparent diffusion coefficient
Authors: Nonomura Yoshie , Yasumoto Mayumi , Yoshimura Ryoichi , Haraguchi Kyoko , Ito Sukeyuki , Akashi Takumi , Ohashi Isamu 
Published: August 2002

AbstractThis study was performed to determine if there is a relationship between apparent diffusion coefficient (ADC) and cellularity of bone marrow of the posterior ilium. Four groups of various marrow cellularity underwent diffusion‐weighted echo‐planar imaging: 1) adults with normal hypocellularity (21 patients); 2) adults with normal normocellularity (13 patients); 3) young children with normal hypercellularity (5 patients); and 4) adults with lymphoma‐related hypercellularity (3 patients). In all adults, marrow cellularity was confirmed by uni‐or bilateral bone marrow biopsies. In children, the iliac marrow was presumed hypercellular because of their ages. A total of 66 ADC values of bone marrow calculated from diffusion‐weighted images with b‐values of 30 and 300 seconds/mm2 was evaluated. Hypercellular marrow (normal and lymphoma‐related) showed the highest mean ADC, and hypocellular the lowest ADC. Statistically significant differences were found between three groups of normal marrow: hypocellular, normocellular, and hypercellular. There is a positive correlation between ADC and cellularity of bone marrow. J. Magn. Reson. Imaging 2001;13:757–760. © 2001 Wiley‐Liss, Inc.
Development, standardization, and testing of a lexicon for reporting contrast‐enhanced breast magnetic resonance imaging studies
Authors: Ikeda Debra M. , Hylton Nola M. , Kinkel Karen , Hochman Mary G. , Kuhl Christiane K. , Kaiser Werner A. , Weinreb Jeffrey C. , Smazal Stanley F. , Degani Hadassah , Viehweg Petra , Barclay John , Schnall Mitchell D. 
Published: August 2002

AbstractThe purpose of this study was to develop, standardize, and test reproducibility of a lexicon for reporting contrast‐enhanced breast magnetic resonance imaging (MRI) examinations. To standardize breast MRI lesion description and reporting, seven radiologists with extensive breast MRI experience developed consensus on technical detail, clinical history, and terminology reporting to describe kinetic and architectural features of lesions detected on contrast‐enhanced breast MR images. This lexicon adapted American College of Radiology Breast Imaging and Data Reporting System terminology for breast MRI reporting, including recommendations for reporting clinical history, technical parameters for breast MRI, descriptions for general breast composition, morphologic and kinetic characteristics of mass lesions or regions of abnormal enhancement, and overall impression and management recommendations. To test morphology reproducibility, seven radiologists assessed morphology characteristics of 85 contrast‐enhanced breast MRI studies. Data from each independent reader were used to compute weighted and unweighted kappa (κ) statistics for interobserver agreement among readers. The MR lexicon differentiates two lesion types, mass and non‐mass‐like enhancement based on morphology and geographical distribution, with descriptors of shape, margin, and internal enhancement. Lexicon testing showed substantial agreement for breast density (κ = 0.63) and moderate agreement for lesion type (κ = 0.57), mass margins (κ = 0.55), and mass shape (κ = 0.42). Agreement was fair for internal enhancement characteristics. Unweighted kappa statistics showed highest agreement for the terms dense in the breast composition category, mass in lesion type, spiculated and smooth in mass margins, irregular in mass shape, and both dark septations and rim enhancement for internal enhancement characteristics within a mass. The newly developed breast MR lexicon demonstrated moderate interobserver agreement. While breast density and lesion type appear reproducible, other terms require further refinement and testing to lead to a uniform standard language and reporting system for breast MRI. J. Magn. Reson. Imaging 2001;13:889–895. © 2001 Wiley‐Liss, Inc.
Line scan diffusion tensor MRI of the cervical spinal cord in preterm infants
Authors: Murphy Brendan P. , Zientara Gary P. , Huppi Petra S. , Maier Stephan E. , Barnes Patrick D. , Jolesz Ferenc A. , Volpe Joseph J. 
Published: August 2002

AbstractLine scan diffusion tensor magenetic resonance imaging (DT‐MRI) of the cervical spinal cord was demonstrated in vivo for unsedated preterm (gestational age 24–30 weeks at birth), very low birthweight (birthweight 620–1300 g) infants at postmenstrual ages from 29–40 weeks. Scalar invariant measures of diffusion [apparent diffusion coefficient (ADC) and relative anisotropy (RA)] determined from a cervical cord region of interest in each case are reported, characterizing the maturational status of the normal third trimester and newborn spinal cord. Mean ADC of 11 infants was 1.2 ± 0.1 μm2/msec and the mean RA was 24.3 ± 4.9%. Normal infant cord neural fiber tract morphology was visualized using a mapping of the predominant diffusion tensor eigenvector. Potential clinical applications of line scan DT‐MRI of the spinal cord of preterm and term newborns for assessment of spinal cord injury are discussed. J. Magn. Reson. Imaging 2001;13:949–953. © 2001 Wiley‐Liss, Inc.
PROPELLER MRI: Clinical testing of a novel technique for quantification and compensation of head motion
Authors: Forbes Kirsten P.N. , Pipe James G. , Bird C. Roger , Heiserman Joseph E. 
Published: August 2002

AbstractWhile head motion is considered a significant problem in magnetic resonance imaging (MRI), there is no data to quantify its extent, severity, or effect on image quality. PROPELLER (Periodically Rotated Overlapping ParallEL Lines with Enhanced Reconstruction) MRI offers a novel means of quantifying and compensating for head motion. We performed axial T2‐weighted PROPELLER (motion corrected: P‐CR; uncorrected: P‐UNCR) and conventional MRI (CONV), with equal scan times, in five normal volunteers and 35 clinical subjects. Volunteers were examined lying still and performing two separate head movements (shake “no” and nod “yes”) to assess detection and compensation of in‐plane motion by PROPELLER MRI. Images were examined by three radiologists for motion artifact and for overall image quality. Head rotation and translation was detected in all subjects during each slice acquisition, with expected changes occurring with volunteer head motion. Motion artifact was less commonly seen on PROPELLER than CONV MR (χ2 test P < 0.001). PROPELLER was preferred over CONV in all subjects (P < 0.05) and P‐CR was judged superior to P‐UNCR (P = 0.02). Intracranial pathology was equally or better demonstrated with PROPELLER. PROPELLER MRI offers a means of quantifying head motion, reducing motion artifact, and improving image quality. J. Magn. Reson. Imaging 2001;14:215–222. © 2001 Wiley‐Liss, Inc.
Evaluation of perianal sepsis: Comparison of anal endosonography and magnetic resonance imaging
Authors: Maier Andrea G. , Funovics Martin A. , Kreuzer Sören H. , Herbst Friedrich , Wunderlich Max , Teleky Bela K. , Mittlböck Martina , Schima Wolfgang , Lechner Gerhard L. 
Published: August 2002

AbstractThe purpose of this study was to compare prospectively the diagnostic yield of anal endosonography (AES) and magnetic resonance imaging (MRI) in the assessment of perianal fistulae and abscesses. There were 39 patients (14 men, 25 women; mean age, 40 years) who underwent AES, performed with a 10‐MHz rotating endoanal probe and MRI at 1.0 T (axial and coronal T2‐weighted turbo spin‐echo (TSE) and turbo‐STIR sequences). Fistulae were classified as subcutaneous, intersphincteric, transsphincteric, high (i.e., high extrasphincteric or suprasphincteric), rectovaginal, and horseshoe and were compared with the surgical findings in all patients. Overall, 58 fistulae (subcutaneous, N = 7; intersphincteric, N = 9; transsphincteric, N = 16; high, N = 17; rectovaginal, N = 5; and horseshoe, N = 4) were detected at surgery. MRI showed a sensitivity of 84% and AES of 60% (P < .05). False‐positive diagnoses were made in 6 patients (15%) with MRI and in 15 patients (26%) with AES, for a specificity of 68% and 21%, respectively (P < .05). Our findings show that MRI is superior to AES in the assessment of fistula‐in‐ano before major surgery. AES should be used only for orientation before minor procedures, such as incision or drainage of subcutaneous fistulae. J. Magn. Reson. Imaging 2001;14:254–260. © 2001 Wiley‐Liss, Inc.
The effect of injection rate on time‐resolved contrast‐enhanced peripheral MRA
Authors: Carroll Timothy J. , Korosec Frank R. , Swan J. Shannon , Hany Thomas F. , Grist Thomas M. , Mistretta Charles A. 
Published: August 2002

AbstractIn contrast‐enhanced (CE) magnetic resonance (MR) angiography (MRA), lower injection rates of a fixed contrast agent dose provide longer contrast agent bolus at the expense of lower intravascular signal. This study evaluated the effect of different injection rates in imaging of the vasculature of the lower extremities with time‐resolved, CE MRA. In three volunteers, injection rates of 0.5, 1.5 and 3.0 mL/second were administered in a randomized order and imaged in two separate sessions. Contrast agent bolus dynamics measured in volunteers were used in computer simulations to confirm variations in contrast agent concentration as a source of vessel ringing and blurring artifacts. To validate the effect of injection rate in pathologic vessels, 37 patients with peripheral vascular disease were imaged with a time‐resolved technique using an injection rate of 0.5 mL/second or 1.5 mL/second and retrospectively divided into two groups. In volunteers, higher injection rates caused a stronger modulation of k‐space and resulted in increased ringing artifacts in time‐resolved CE MRA. These results were reproduced with computer simulations. In the qualitative patient study, significantly less vessel blurring was observed using a lower injection‐rate, without a significant loss of vessel contrast. J. Magn. Reson. Imaging 2001;14:401–410. © 2001 Wiley‐Liss, Inc.
Quantitative analysis of memantine in human plasma by gas chromatography/negative ion chemical ionization/mass spectrometry
Authors: Leis Hans Jörg , Fauler Günter , Windischhofer Werner 
Published: August 2002

AbstractA sensitive and specific method for the determination of memantine in human plasma is presented. Memantine was extracted from plasma and derivatized to the pentafluorobenzoyl derivative in a one‐step procedure avoiding any sample concentration steps. Adamantine was used as an internal standard. The compounds were measured by gas chromatography/negative ion chemical ionization mass spectrometry without any further processing. Using this detection mode, the fragment ions at m/z 353 and 325 were obtained at high relative abundance. Calibration graphs were linear over the range 0.117–30 ng ml−1. At the limit of quantification (LOQ), the inter‐assay precision was 2.00% and the intra‐assay variability was 3.22%. The accuracy at the LOQ showed deviations of −1.42% (intra‐assay) and −2.47% (inter‐assay). The method is rugged, rapid and robust and was applied to the batch determination of memantine during pharmacokinetic profiling of the drug. Copyright © 2002 John Wiley & Sons, Ltd.
Use of bacterially expressed EBNA‐1 protein cloned from a nasopharyngeal carcinoma (NPC) biopsy as a screening test for NPC patients
Authors: Chen Mei‐Ru , Liu Mei‐Ying , Hsu Shih‐Mei , Fong Chin‐Chu , Chen Chien‐Jen , Chen I‐How , Hsu Mow‐Ming , Yang Czau‐Siung , Chen Jen‐Yang 
Published: August 2002

AbstractEBV serological tests have been used for many years as accessory diagnostic predictors of nasopharyngeal carcinoma (NPC). To increase the sensitivity and specificity of the NPC detection rate, a novel enzyme‐linked immunosorbent assay (ELISA) was established using a bacterially‐expressed GST‐EBNA‐1 protein, containing the EBNA‐1 sequence cloned from an NPC patient. Serum samples were collected from age‐ and gender‐matched patients with NPC, community control subjects and hospital control patients and tested using this ELISA. The positivity rates were 78.7% (247/314) in NPC, 11.5% (28/244) in hospital controls and 3.8% (10/263) in the community control group. These serum samples were also tested for IgA anti‐VCA antibodies and their ability to neutralize EBV DNase and the sensitivities of the anti‐VCA antibody and DNase‐neutralization tests also were analyzed. The optimum combination is VCA plus EBNA‐1, which can identify 92.5% (287/310) of NPC patients, and shows a specificity of 92.7% (242/261) for normal individuals. J. Med. Virol. 64:51–57, 2001. © 2001 Wiley‐Liss, Inc.
Phenotypic analysis of the sensitivity of HIV‐1 to inhibitors of the reverse transcriptase, protease, and integrase using a self‐inactivating virus vector system
Authors: Jármy Gergely , Heinkelein Martin , Weissbrich Benedikt , Jassoy Christian , Rethwilm Axel 
Published: August 2002

AbstractConventional phenotypic analysis of resistance of the human immunodeficiency virus (HIV) to antiviral therapy is time‐consuming and requires culture of infectious virus. Although phenotypic analyses may be desirable, rapid generation of test results and decentralized availability of the test system will be important to achieve utility in the clinical practice. This study describes the design of an alternative phenotypic resistance test using replication incompetent viral vectors. Chimeric HIV vectors containing a marker gene were generated. The env and most of the regulatory and accessory genes of HIV were removed. In addition, the 3′U3 region was deleted to obtain a self‐inactivating construct. Cotransfection of the plasmid with a plasmid that provided the vesicular stomatitis virus glycoprotein resulted in the production of replication‐incompetent virus vectors. Infection of susceptible cells with the vectors led to marker gene expression. Vector production in the presence of protease (PR) inhibitors, or infection in the presence of reverse transcriptase (RT) or integrase (IN) inhibitors reduced marker gene expression in a dose‐dependent manner. Marker gene activity was preserved at higher drug levels if vectors contained RT and PR genes from resistant virus isolates. Sensitivity to nucleoside and non‐nucleoside RT inhibitors, protease and integrase inhibitors could be determined in 10 working days. The phenotypic drug resistance test using replication‐incompetent HIV vectors significantly speeds up drug resistance measurements and allows testing at reduced biosafety levels. This will make clinical use of phenotypic assessment of antiviral resistance more feasible. J. Med. Virol. 64:223–231, 2001. © 2001 Wiley‐Liss, Inc.