bluuebunny/crossref_metadata_2025_split huggingface dataset:
A new practical tritium labelling procedure using sodium borotritide and tetrakis(triphenylphosphine)palladium(0)
Authors: Nagasaki Tohru , Sakai Katsunori , Segawa Masaharu , Katsuyama Yoshihiko , Haga Nobuhiro , Koike Masahiro , Kawada Kenji , Takechi Shozo 
Published: August 2002

AbstractA simple, mild and versatile new tritium (3H) labelling method on a micro scale using sodium borotritide (NaB3H4) and a transition–metal complex catalyst is described. 3H‐labelled compounds were prepared effectively by 3H hydrogenolysis of appendant functional groups in target compounds. The appendant functional group such as bromo, iodo or sulfonate in various target compounds can be replaced by tritium (3H) in moderate yields. The new method was established by optimization of the reaction conditions and examination of its applicability using four types of model substrates in tracer runs. Then, various drug candidates and ligands for drug discovery were labelled with tritium on a micro scale. The specific radioactivity of the 3H‐labelled compounds used for the studies on receptor binding ranged from 12 to 20 Ci/mmol. Copyright © 2001 John Wiley & Sons, Ltd.
Synthesis of morphine‐[N‐methyl‐14C]‐6‐β‐D‐glucuronide
Authors: Ferguson John R. , Hollis Stephen J. , Johnston Grant A. , Lumbard Keith W. , Stachulski Andrew V. 
Published: August 2002

AbstractProtected morphine‐6‐glucuronide was converted into morphine‐[N‐methyl‐14C]‐6‐glucuronide by a three‐step procedure. Methyl (3‐pivaloylmorphin‐6‐yl 2,3,4‐tri‐O‐isobutyryl‐β‐D‐glucopyranosid)uronate was N‐demethylated by treatment with 1‐chloroethyl chloroformate to afford protected normorphine‐6‐glucuronide as its hydrochloride salt. The normorphine‐6‐glucuronide derivative was alkylated with iodomethane‐[14C] in the presence of potassium carbonate to produce C‐14 labelled protected morphine‐6‐glucuronide. Finally, hydrolysis of the protecting groups using 5% sodium hydroxide solution gave morphine‐[N‐methyl‐14C]‐6‐β‐D‐glucuronide with a specific activity of 41.8 mCi mmol−1 and radiochemical purity of 99.2% (HPLC). Copyright © 2002 John Wiley & Sons, Ltd.
Relation between the outer cover of the egg case of Argiope aurantia (Araneae: Araneidae) and the emergence of its spiderlings
Authors: Foradori Matthew J. , Kovoor Jacqueline , Moon Myung‐Jin , Tillinghast Edward K. 
Published: August 2002

AbstractTo emerge from the egg case, Argiope aurantia spiderlings must penetrate a tightly woven outer cover composed primarily of large‐diameter cylindrical gland fibers and small‐diameter fibers, likely of aciniform gland origin. They accomplish this using enzymatic digestion and mastication to form a communal hole in the outer cover. The involvement of proteolytic enzymes in this process was demonstrated by zymography of spiderling homogenates and washes made from the edges of holes. The specific source(s) of the proteases is unknown, but histological examination of spiderling sections indicates that the digestive tract, venom glands, and gnathocoxal glands are all functioning at the time of emergence from the egg case. Observations on edges of holes indicate that spiderlings are able to solubilize the small‐diameter fibers completely, but cylindrical gland fibers only partially. In the outer cover, cylindrical fibers are composed of numerous fibrils embedded within a matrix. Spiderlings appear to be unable to solubilize the fibrils, but digestion of the matrix allows the spiderlings to push the fibrils aside to create the opening. J. Morphol. 252:218–226, 2002. © 2002 Wiley‐Liss, Inc.
Exploration of sequence space for protein engineering
Authors: Gustafsson Claes , Govindarajan Sridhar , Emig Robin 
Published: August 2002

AbstractThe process of protein engineering is currently evolving towards a heuristic understanding of the sequence–function relationship. Improved DNA sequencing capacity, efficient protein function characterization and improved quality of data points in conjunction with well‐established statistical tools from other industries are changing the protein engineering field. Algorithms capturing the heuristic sequence–function relationships will have a drastic impact on the field of protein engineering. In this review, several alternative approaches to quantitatively assess sequence space are discussed and the relatively few examples of wet‐lab validation of statistical sequence–function characterization/correlation are described. Copyright © 2001 John Wiley & Sons, Ltd.
Need for background suppression in contrast‐enhanced peripheral magnetic resonance angiography
Authors: Leiner Tim , de Weert Thomas T. , Nijenhuis Robbert J. , Vasbinder G. Boudewijn C. , Kessels Alphons G.H. , Ho Kai Yiu J.A.M. , van Engelshoven Jos M.A. 
Published: August 2002

AbstractTo determine if background suppression is beneficial for peripheral magnetic resonance angiography (pMRA), nonsubtracted, subtracted, and fat‐saturated contrast‐enhanced (CE) pMRA were compared in 10 patients with peripheral arterial disease. Signal‐to‐noise ratios (SNRs) and contrast‐to‐noise ratios (CNRs), as well as venous enhancement and subjective interpretability, were determined in a station‐by‐station fashion for each technique. In three patients X‐ray angiography was available as a standard of reference. SNRs and CNRs were significantly higher for fat‐saturated vs. the other two techniques (P = 0.005). Subjective interpretability was best for subtracted data sets in the lower‐leg station. In the iliac station, fat‐saturated data sets were considered to have significantly lower interpretability than subtracted data sets. Venous enhancement occurred significantly more often in the lower‐leg station with the fat‐saturated technique. The value of subtraction depends on the hardware one has available and is a useful tool if dedicated surface coils are used. Background suppression by means of magnitude subtraction leads to the best lower‐leg image interpretability. Care must be taken to avoid venous enhancement in the lower‐leg station when using fat saturation. J. Magn. Reson. Imaging 2001;14:724–733. © 2001 Wiley‐Liss, Inc.
Imaging of finger joints in a whole‐body MR system using a simple and low‐cost solenoidal coil
Authors: Rumpel Helmut , Peh Wilfred C.G. 
Published: August 2002

AbstractThis work considers the design and operation of a solenoid radiofrequency (RF) coil for magnetic resonance (MR) mini‐imaging of finger joints using a whole‐body system. The considerations were focused on the requirements of high sensitivity, easy patient access, and cost‐effectiveness. The proposed design is a short, two‐turn solenoidal coil that accomplishes high spatial uniformity over a 2‐cm region of interest (ROI). The coil resembles an oversized ring, and easily fits fingers that are spread. An experimental demonstration of the proposed approach is given by imaging the proximal interphalangeal joint in healthy volunteers using a 2.5‐cm field of view (FOV). Spin‐echo and gradient‐recalled‐echo T1‐weighted sequences, and a 3D spoiled‐gradient‐echo sequence were used. J. Magn. Reson. Imaging 2001;14:800–802. © 2001 Wiley‐Liss, Inc.
Magnetic resonance imaging of pulmonary parenchymal disease using a modified breath‐hold 3D gradient‐echo technique: Initial observations
Authors: Bader Till R. , Semelka Richard C. , Pedro Monica S. , Armao Diane M. , Brown Mark A. , Molina Paul L. 
Published: August 2002

AbstractPurposeTo determine the potential of a modified breath‐hold 3D gradient‐echo technique for visualizing pulmonary parenchymal diseases.Materials and MethodsTwenty‐one magnetic resonance imaging (MRI) studies of the lungs were performed in 20 patients (15 male and 5 female; age range, 7.7–86.1 years) with pulmonary diseases comprising non‐small‐cell, small‐cell, and bronchioalveolar carcinomas, endobronchial mucoepidermoid carcinoma, metastases, pneumonia, Wegener's granulomatosis, chronic obstructive pulmonary disease, arterio‐venous malformation, and bronchogenic cyst. Confirmation of diagnoses was obtained via histopathology (14 patients) and follow‐up (6 patients). MRI studies were performed at 1.5 T before and after administration of gadolinium using a modified volumetric interpolated breath‐hold examination (VIBE) sequence. All images were evaluated prospectively regarding lesion detection and characterization. MR findings were correlated with final diagnoses. Retrospective grading (scores, 1–4) was performed for general image quality (rated “poor” to “excellent”); presence of artifacts (“negligible” to “severe”); and imaging quality of pulmonary lesions (conspicuity and contrast on pre‐ and postgadolinium images).ResultsTwenty‐three solid pulmonary lesions, 25 infiltrates and segmental atelectases, and 1 cyst were detected and prospectively correctly diagnosed. Sizes ranged from 0.3–10 cm. The mean scores for image quality and presence of artifacts were 3.3 (SD, 0.7) and 1.8 (SD, 0.7), respectively. Conspicuity and contrast of pulmonary lesions received mean scores between 3.0 and 3.8 (SD, 0.4–0.7).ConclusionThis MRI technique allows imaging of a wide spectrum of solid and nonsolid pulmonary parenchymal diseases with reproducible high image quality, effective suppression of artifacts, high resolution, and visualization of gadolinium enhancement. J. Magn. Reson. Imaging 2002;15:31–38. © 2002 Wiley‐Liss, Inc.
Estimation of gallbladder ejection fraction utilizing cholecystokinin‐stimulated magnetic resonance cholangiography and comparison with hepatobiliary scintigraphy
Authors: Vyas Pranav K. , Vesy Thomas L. , Konez Orhan , Ciavellara David P. , Hua Keidang , Gaisie Godfrey 
Published: August 2002

AbstractPurposeTo evaluate the utility of magnetic resonance cholangiography (MRC) in estimation of gallbladder ejection fraction (GBEF) and to comparing this value to the conventional method, hepatobiliary scintigraphy (HBS).Materials and MethodsTwenty‐one healthy volunteers were imaged on sequential weeks to determine GBEF using MRC and HBS. GBEF was calculated by HBS after infusion of 20 ng/kg of sincalide following injection of 111 Mbq of Tc 99m mebrofenin. For estimation by MRC, imaging of the gallbladder was performed before and after slow infusion of sincalide every 5 minutes, for a total of 60 minutes. Gallbladder imaging was performed using a heavily T2‐weighted 2D fast spin echo (FSE) sequence. Data was analyzed using a variance component analysis technique.ResultsMean GBEF by HBS was 65.7%, with an SD of ±27.3%. Mean GBEF by MRC was 62.7%, with an SD of ± 20.4%. If minimum normal GBEF is set at 35%, two of the cases showed discordance, with HBS calculating an abnormally low average GBEF compared to MRC. Additionally, two cases showed abnormally low GBEF for both modalities. The coefficient of correlation between HBS and MRC was 0.72. Inter‐ and intraobserver variance is acceptable within the two modalities with <1.1% variation.ConclusionGBEF can be calculated with MRC, yielding similar values when a group of volunteers are considered. Further study with symptomatic patients is needed to determine the validity of this technique for clinical diagnosis. J. Magn. Reson. Imaging 2002;15:75–81. © 2002 Wiley–Liss, Inc.
Characterization of focal hepatic lesions with ferumoxides‐enhanced MR imaging: Utility of T1‐weighted spoiled gradient recalled echo images using different echo times
Authors: Kim Joo Hee , Kim Myeong‐Jin , Suh Sang Hyun , Chung Jae‐Joon , Yoo Hyung Sik , Lee Jong Tae 
Published: August 2002

AbstractPurposeTo evaluate the different signal characteristics of focal hepatic lesions on ferumoxides‐enhanced MR imaging, including T1‐weighted spoiled gradient recalled echo (GRE) images using different echo times (TE) and T2‐ and T2*‐weighted images.Materials and MethodsFerumoxides‐enhanced MR imaging was performed using a 1.5‐T system in 46 patients who were referred for evaluation of known or suspected hepatic malignancies. One hundred and seven lesions (42 hepatocellular carcinomas [HCC], 40 metastases, 13 cysts, eight hemangiomas, three focal nodular hyperplasias [FNHs], and one cholangiocarcinoma) were evaluated. Postcontrast MR imaging included 1) T2‐weighted FSE; 2) T2*‐weighted GRE; 3) T1‐weighted spoiled GRE using moderate (TE = 4.2–4.4 msec) TE; and 4) minimum (TE = 1.8–2.1 msec) TE. Signal intensities of the focal lesions were rated by two radiologists in conference as follows: hypointense, isointense or invisible, hyperintense, and markedly hyperintense. Lesion‐to‐liver contrast‐to‐noise ratio (C/N) was measured by one radiologist for a quantitative assessment.ResultsOn ferumoxides‐enhanced FSE images, 92% of cysts were “markedly hyperintense” and most of the other lesions were “hyperintense”, and the mean C/N of cysts was significantly higher than that of other focal lesions. T2*‐weighted GRE images showed most lesions with similar hyperintensities and the mean C/N was not significantly different between any two types of lesion. T1‐weighted GRE images using moderate TE showed all FNHsand hemangiomas, 29 (69%) HCCs and eight (20%) metastases as “hyperintense”. On T1‐weighted GRE images using minimum TE, however, all HCCs and metastasis except one were iso‐ or hypointense, while all of the FNHs and hemangiomas were hyperintense. Ring enhancement was highly suggestive of malignant lesions, and was more commonly seen on the minimum TE images than on the moderate TE images.ConclusionAddition of T1‐weighted GRE images using minimum and moderate TE is helpful for characterizing focal lesions in ferumoxides‐enhanced MR imaging. J. Magn. Reson. Imaging 2002;15:573–583. © 2002 Wiley‐Liss, Inc.
Improved multi‐station peripheral MR angiography with a dedicated vascular coil
Authors: Goyen Mathias , Ruehm Stefan G. , Barkhausen Jörg , Kröger Knut , Ladd Mark E. , Truemmler Karl‐Heinz , Bosk Silke , Requardt Martin , Reykowski Arne , Debatin Jörg F. 
Published: August 2002

AbstractDelineation of small branch vessels can be crucial for assessing the peripheral arterial system of patients requiring surgical grafting. Thus signal‐to‐noise needs to be maximized. We evaluated the performance of a dedicated peripheral vascular coil in four subjects by comparing it to the body coil using DSA as the standard of reference. SNR and CNR values of the dedicated peripheral coil exceeded those obtained with the body coil by a mean of 398%, thus permitting improved delineation of the infrapopliteal arterial morphology. J. Magn. Reson. Imaging 2001;13:475–480. © 2001 Wiley‐Liss, Inc.
Analysis of contrast‐enhanced dynamic MR images of the lung
Authors: Torheim Geir , Amundsen Tore , Rinck Peter A. , Haraldseth Olav , Sebastiani Giovanni 
Published: August 2002

AbstractRecent studies have demonstrated the potential of dynamic contrast‐enhanced magnetic resonance imaging (MRI) describing pulmonary perfusion. However, breathing motion, susceptibility artifacts, and a low signal‐to‐noise ratio (SNR) make automatic pixel‐by‐pixel analysis difficult. In the present work, we propose a novel method to compensate for breathing motion. In order to test the feasibility of this method, we enrolled 53 patients with pulmonary embolism (N = 24), chronic obstructive pulmonary disease (COPD) (N = 14), and acute pneumonia (N = 15). A crucial part of the method, an automatic diaphragm detection algorithm, was evaluated in all 53 patients by two independent observers. The accuracy of the method to detect the diaphragm showed a success rate of 92%. Furthermore, a Bayesian noise reduction technique was implemented and tested. This technique significantly reduced the noise level without removing important clinical information. In conclusion, the combination of a motion correction method and a Bayesian noise reduction method offered a rapid, semiautomatic pixel‐by‐pixel analysis of the lungs with great potential for research and clinical use. J. Magn. Reson. Imaging 2001;13:577–587. © 2001 Wiley‐Liss, Inc.
MR‐guided biopsy of musculoskeletal lesions in a low‐field system
Authors: Koenig Claudius W. , Duda Stephan H. , Truebenbach Jochen , Schott Ulrich G. , Maurer Franz , Claussen Claus D. , Pereira Philippe L. 
Published: August 2002

AbstractThirty magnetic resonance (MR)‐guided biopsies were obtained from 20 skeletal and 10 soft‐tissue lesions in 31 patients using an open 0.2 T MR system equipped with interventional accessories. The results from aspiration (N = 3), core biopsy (N = 15), and transcortical trephine biopsy (N = 12) were evaluated for accuracy and clinical efficacy. Specimens were successfully obtained from 29 patients. Results were clinically effective in 23 patients, rated definitive in 16, nonconclusive in 9, and unspecific in 2 patients. A false diagnosis due to sampling error occurred in 2 patients, and biopsy sampling was impossible in one case. The best diagnostic yield was achieved from nontranscortical biopsies of osteolytic or soft‐tissue masses. Results from transcortical biopsies were less specific due to the predominance of benign lesions. MR fluoroscopy for needle guidance was applied in 13 patients. Complete needle placement inside the magnet could be performed in 16 patients. MR‐guided biopsy using an open low‐field MR imager is feasible and clinically effective and will become a valuable tool in the management of musculoskeletal lesions. J. Magn. Reson. Imaging 2001;13:761–768. © 2001 Wiley‐Liss, Inc.
MRI: A role in clinical trials
Authors: Julian Thomas B. 
Published: August 2002

AbstractThe diagnosis and treatment of breast cancer has evolved significantly over the last 20 years. Breast‐conserving therapy is replacing the Halstedian concept of “en bloc” resection. Difficulties in detection, pre‐ and postoperative planning and follow up continue to challenge the clinician. Women at high risk present a significant clinical dilemma. MRI technology in many of these areas is providing more information about detection, tumor size, extent, and response to treatment. The careful and thoughtful inclusion of MRI in clinical trials may help continue the advancement of breast cancer care. J. Magn. Reson. Imaging 2001;13:837–841. © 2001 Wiley‐Liss, Inc.
Anatomy and physiology of the female pelvis: MR imaging revisited
Authors: Togashi Kaori , Nakai Asako , Sugimura Kazuro 
Published: August 2002

AbstractThis article reviews the normal anatomy of the female pelvis and focuses on uterine physiology, presenting the kinematics of the uterus that can be identified on ultra‐fast MR imaging. It also discusses the many facets of the junctional zone on MR imaging. Ultra‐fast MR imaging seems to be a powerful tool for evaluating normal anatomy, physiology, and pathology of the uterus. J. Magn. Reson. Imaging 2001;13:842–849. © 2001 Wiley‐Liss, Inc.
Improving the detectability of focal liver lesions on T2‐weighted MR images: Ultrafast breath‐hold or respiratory‐triggered thin‐section MRI?
Authors: Pauleit Dirk , Textor Jochen , Bachmann Reinald , Conrad Rudolf , Flacke Sebastian , Kreft Burkhard , Schild Hans 
Published: August 2002

AbstractThe purpose of this study was to determine whether a respiratory‐triggered (RT) T2‐weighted turbo spin‐echo (TSE) sequence with thin section can improve the detectability of focal liver lesions compared to a breath‐hold (BH) T2‐weighted TSE sequence. In 25 patients an RT TSE with 8‐mm sections (8‐TSE RT) and 5‐mm sections (5‐TSE RT) and a BH TSE sequence with 8‐mm sections (8‐TSE BH) were performed. Forty‐one focal liver lesions (mean: 1.8 ± 1.2 cm; 14 lesions ≤1 cm; 27 lesions >1 cm) were evaluated. The 5‐TSE RT was significantly better in lesion detection compared to the 8‐TSE BH sequence for all sizes of lesions (40/41 vs. 33/41; P = 0.014). For lesions >1 cm no relevant differences in the detection rate of the sequences were found (8‐TSE RT, 26/27; 5‐TSE RT, 26/27; 8‐TSE BH, 25/27), for lesions ≤1 cm the 5‐TSE RT provided significantly better sensitivity than the 8‐TSE BH (14/14 vs. 8/14, P = 0.015). The results of this study suggest that lesion detection could be significantly improved by using an RT TSE sequence with thin sections compared with a BH TSE sequence. J. Magn. Reson. Imaging 2001;14:128–133. © 2001 Wiley‐Liss, Inc.
Capsaicin as a source for painful stimulation in functional MRI
Authors: Malisza Krisztina L. , Docherty John C. 
Published: August 2002

AbstractFunctional magnetic resonance imaging (fMRI) was used to examine the brain processing of capsaicin‐induced painful stimulation in the α‐chloralose anesthetized rat. Experiments were performed on a 9.4‐T magnet (Magnex, UK) with Avance console (Bruker, Germany) using a surface coil tuned to 400.5 MHz centred over the rat forebrain. Gradient‐echo images of two slices, with an echo time of 25 msec, repetition time of 70 msec, and 50 repetitions, were acquired per experiment. These images were analyzed using a fuzzy cluster analysis technique (EvIdent™). Activation of areas of the brain known to be associated with the processing of pain, namely the anterior cingulate (bilateral), frontal cortex (bilateral), and sensory motor cortex (contralateral), was found in all animals (N = 6) following injection of 25μL of capsaicin (128μg/mL in 7.5% dimethylsulfoxide [DMSO]) into the dorsal forepaw. It is possible to reproduce the pain response in a given animal several times throughout the course of an experiment, provided that sufficient time is allowed between capsaicin injections. This acute phase of capsaicin‐induced pain involving stimulation of C polymodal nociceptors was examined by functional imaging. There was a substantial initial increase in activation in regions of the brain associated with pain and there was a trend towards increasing activation with repeated stimulations. Treatment with morphine (3 mg/kg, intravenously) was found to substantially reduce, if not completely eliminate, the areas of functional activation associated with physiologic pain (anterior cingulate and frontal cortex) after C‐nociceptor stimulation with capsaicin (N = 6). FMRI involving capsaicin‐induced painful stimulation could prove to be an effective tool for the study of novel analgesics and the central nervous system processing of pain. J. Magn. Reson. Imaging 2001;14:341–347. © 2001 Wiley‐Liss, Inc.
Adaptive vessel tracking: Automated computation of vessel trajectories for improved efficiency in 2D coronary MR angiography
Authors: Saranathan Manojkumar , Ho Vincent B. , Hood Maureen N. , Foo Thomas K. F. , Hardy Christopher J. 
Published: August 2002

AbstractA new method was investigated for improving the efficiency of ECG‐gated coronary magnetic resonance angiography (CMRA) by accurate, automated tracking of the vessel motion over the cardiac cycle. Vessel tracking was implemented on a spiral gradient‐echo pulse sequence with sub‐millimeter in‐plane spatial resolution as well as high image signal to noise ratio. Breath hold 2D CMRA was performed in 18 healthy adult subjects (mean age 46 ± 14 years). Imaging efficiency, defined as the percentage of the slices where more than 30 mm of the vessel is visualized, was computed in multi‐slice spiral scans with and without vessel tracking. There was a significant improvement in the efficiency of the vessel tracking sequence compared to the multi‐slice sequence (56% vs. 32%, P < 0.001). The imaging efficiency increased further when the true motion of the coronary arteries (determined using a cross correlation algorithm) was used for vessel tracking as opposed to a linear model for motion (71% vs. 57%, P < 0.05). The motion of the coronary arteries was generally found to be linear during the systolic phase and nonlinear during the diastolic phase. The use of subject‐tailored, automated tracking of vessel positions resulted in improved efficiency of coronary artery illustration on breath held 2D CMRA. J. Magn. Reson. Imaging 2001;14:368–373. Published 2001 Wiley‐Liss, Inc.