bluuebunny/crossref_metadata_2025_split huggingface dataset:
Borohydride exchange resin as an alternative method for deuterium labelling: selective reduction of aryl bromides
Authors: Landvatter Scott W. , Schauer Douglas J. , Garnes Keith T. , Mack James F. , Killmer Lewis B. 
Published: August 2002

AbstractTransition metal‐activated borohydride exchange resin and borodeuteride exchange resin have been prepared and used for the selective reductive deuteration of aryl bromides. This methodology, which utilizes deuterated methanol as the primary source of label, provides an alternative method for the introduction of deuterium. Investigation of which bond in the solvent donates the deuterium and model reductions on ortho‐bromo‐N,N‐dimethylbenzamide suggest that an organocopper(III) intermediate is most likely involved. The immobilized hydride on resin also provides an easy workup and gives products of high purity. This methodology is far more selective than typical catalytic deuteration and, in most cases, provides products with high levels of deuterium incorporation. Copyright © 2001 John Wiley & Sons, Ltd.
Synthesis of 13C‐labelled cinnamonitrile
Authors: Zippi Elizabeth M. , Kamperman Evan 
Published: August 2002

Abstract13C‐labelled cinnamonitrile, a compound that possesses both the aromatic functionality of styrene and the nitrile functionality of acrylonitrile has been synthesized in one step using β‐bromostyrene and potassium [13C]cyanide. The preparation of a target material using 13C ‐labelled cinnamonitrile may provide a cost‐effective method for producing nitrogen‐13 via proton irradiation for Positron Emission Tomography. Copyright © 2002 John Wiley & Sons, Ltd.
Proton and metal‐ion activation of C–H exchange in five‐membered azoles
Authors: Buncel Erwin , Onyido Ikenna 
Published: August 2002

AbstractFactors influencing C–H isotopic exchange rates in five‐membered azoles, that is imidazoles and thiazoles, under catalysis by H+ and Mn+, especially transition metals, Pt(II) and Co(III) are discussed. Hydrogen ion catalysis through N(3) protonation of azoles 1–3 is generally the most efficient, with rate enhancements in the range 102–109 over the neutral process being attained. Metal‐ion coordination also results in effective catalysis, though less so than catalysis by protons. Catalysis of C–H exchange by Mn+ can be studied through addition of the metal salts to a buffered solution of the heterocycle in which labile complexes exist, or on synthesized complexes such as 4–13 which are substitution‐inert thus precluding complications from unknown dissociation equilibria. A delicate balance of factors influence the ease of C–H exchange, including: (1) the magnitude of the fractional charge located at N(3) of the heterocycle through Mn+–N(3) σ bond polarization; (2) metal‐to‐ligand π back‐bonding; (3) the electronic structure of the metal ions. These considerations have obvious consequences for deuterium‐ and tritium‐labelling of a number of biomolecules, e.g. proteins, enzymes, nucleic acids, some vitamins, as well as drugs which incorporate five‐membered azoles in their structures. Copyright © 2002 John Wiley & Sons, Ltd.
Regio‐ and stereoselective preparation of ascomycin‐d1 and FK 506‐d1
Authors: Acemoglu Murat , Andres Hendrik , Moenius Thomas 
Published: August 2002

AbstractThe immunosuppressive macrolides ascomycin 1 and FK 506 2 were stereoselectively deuteriated at C(32) using Curran's radical translocating method. Both AIBN and Et3B/O2 were tested as radical initiator for the radical translocation/reduction step with Bu3SnD as reducing agent. Despite only minor structural differences, ascomycin and FK 506 showed remarkably different behaviour under the radical translocation/reduction conditions. Higher stereoselectivities were observed with Et3B/O2 as initiator, presumably due to lower reaction temperatures applied in this case. Copyright © 2002 John Wiley & Sons, Ltd.
Lipotyphla limb myology comparison
Authors: Neveu Pauline , Gasc Jean‐Pierre 
Published: August 2002

AbstractFore‐ and hindlimb muscles were dissected in four species of Lipotyphla: the western European hedgehog Erinaceus europaeus (Erinaceidae, Erinaceinae); the moonrat Echinosorex gymnura (Erinaceidae, Hylomyinae or Galericinae); the tailless tenrec Tenrec ecaudatus (Tenrecidae, Tenrecinae); and the common European white‐toothed shrew Crocidura russula (Soricidae, Soricinae). This work completely reviews the limb musculature of these walking mammals. Twelve myological characters were evaluated in order to disclose phylogenetic relationships. The cladogram obtained supported previous ones based on cranial and dental characters. This study shows that myological characters are valuable in phylogenetic analyses. J. Morphol. 252:183–201, 2002. © 2002 Wiley‐Liss, Inc.
How tubular venom‐conducting fangs are formed
Authors: Jackson Kate 
Published: August 2002

AbstractElapids, viperids, and some other groups of colubroid snakes have tubular fangs for the conduction of venom into their prey. The literature describing the development of venom‐conducting fangs provides two contradictory accounts of fang development. Some studies claim that the venom canal forms by the infolding of a deep groove along the surface of the tooth to produce an enclosed canal. In other works the tubular fang is said to form by the deposition of material from tip to base, so that the canal develops without any folding. This study was undertaken to examine fang development and to account for the disagreement in the literature by determining whether fang formation varies among groups of venomous snakes and whether it differs between embryos and adults. Adult and embryonic representatives of elapids and viperids were examined. All fangs examined, elapid and viperid, embryos and adults, were found to develop into their tubular shape by the addition of material to the basal end of the tooth rather than by the folding inward of an ungrooved tooth to form a tubular fang. In some cases, the first fang that develops in embryonic snakes differs morphologically from all those formed subsequently. J. Morphol. 252:291–297, 2002. © 2002 Wiley‐Liss, Inc.
Structural determinants of the human idiotype HibId‐1
Authors: Reason Donald C. , O'Connor Adam P. , Lucas Alexander H. 
Published: August 2002

AbstractThe human antibody response to the capsular polysaccharide of Haemophilus influenzae type b is predominated by antibodies expressing a light‐chain‐associated idiotype designated HibId‐1. HibId‐1 is expressed by κ light chains encoded by either the A2 or A18 variable region genes. In this report we use site‐directed mutagenesis and molecular modeling to show that HibId‐1 expression is determined by residues in the first and second complimentarity determining regions that are widely separated in the primary sequence, but closely juxtaposed by the tertiary folding of the mature light chain molecule. Of the known human light chains, only alleles of A2 and A18 encode these residues at these positions in their germline configuration. VIG10, a mouse monoclonal antibody of unknown specificity that expresses HibId‐1, and 23F.2, an A2‐utilizing Streptococcus pneumoniae 23F polysaccharide‐specific human Fab fragment that lacks HibId‐1, provide examples of the HibId‐1 determinant both arising and being lost by somatic mutation. In addition, we show that the residues responsible for HibId‐1 expression can be disassociated from those required for antigen binding. Copyright © 2001 John Wiley & Sons, Ltd.
Involvement of the C‐terminal end of the prostrate‐specific antigen in a conformational epitope: characterization by proteolytic degradation of monoclonal antibody‐bound antigen and mass spectrometry
Authors: Michel Sandrine , Forest Eric , Pétillot Yves , Deléage Gilbert , Heuzé‐Vourc'h Nathalie , Courty Yves , Lascoux David , Jolivet Michel , Jolivet‐Reynaud Colette 
Published: August 2002

AbstractProstate‐specific antigen (PSA), a 237‐amino acid glycoprotein, encoded by the hKLK3 gene, is widely used as a serum marker for the diagnosis and management of prostate cancer. We report here the localization of a conformational epitope recognized by the anti‐total PSA monoclonal antibody (mAb) 11E5C6, by proteolytic degradation of mAb‐bound antigen followed by mass spectrometric analyses of the peptides generated. These two technologies, combined with molecular display, allowed the identification of amino acid residues contained within three different peptides distant on the PSA sequence, but close in the PSA three‐dimensional structure, that may be part of the mAb 11E5C6 epitope. The last four C‐terminal amino acid residues are included in this epitope, as well as certain other C‐terminal residues between Y225 and T232. The involvement of the PSA C‐terminal end in the mAb 11E5C6 epitope was confirmed by western blotting experiments with the recombinant protein proPSA‐RP1, resulting from the cloning of an alternative transcript of the hKLK3 gene, in which the PSA C‐terminal end was deleted and replaced by another sequence. Although the anti‐total PSA mAb 5D5A5 used as a control bound proPSA‐RP1, mAb 11E5C6 did not. The requirement of the C‐terminal end for the recognition by mAb 11E5C6 may be useful for the discrimination of PSA‐related forms. Copyright © 2001 John Wiley & Sons, Ltd.
Evaluation of the rotator cuff and glenoid labrum using a 0.2‐Tesla extremity magnetic resonance (MR) system: MR results compared to surgical findings
Authors: Shellock Frank G. , Bert Jack M. , Fritts Hollis M. , Gundry Cooper R. , Easton Ruth , Crues John V. 
Published: August 2002

AbstractThe purpose of this investigation was to evaluate the diagnostic capabilities of magnetic resonance imaging (MRI) performed using a dedicated‐extremity MR system in detecting lesions of the rotator cuff and glenoid labrum. This retrospective study compared the MR results obtained in 47 patients that underwent MRI using a 0.2‐Tesla extremity MR system (E‐scan) to the surgical findings. MR images of the shoulder were obtained as follows: shoulder coil, T1‐weighted, coronal‐oblique and axial images; short Tau inversion recovery (STIR), coronal‐oblique images; and T2‐weighted, coronal‐oblique, sagittal‐oblique, and axial images. The MR examinations were interpreted by three highly experienced, musculoskeletal radiologists. Open surgical (N = 26) or arthroscopic (N = 21) procedures were performed within a mean time of 33 days after MRI. The surgical findings revealed rotator cuff tears in 28 patients and labral lesions in 9 patients. For the rotator cuff tears, the sensitivity, specificity, positive predictive value, and negative predictive value were 89%, 100%, 100%, and 90%, respectively. For the labral lesions, the sensitivity, specificity, positive predictive value, and negative predictive value were 89%, 95%, 80%, and 97%, respectively. The findings indicated that there was good agreement comparing the MR results obtained using the low‐field extremity MR system to the surgical findings for determination of lesions of the rotator cuff and glenoid labrum. Notably, the statistical values determined for the use of this MR system were comparable to those reported in the peer‐reviewed literature for the use of whole‐body, mid‐ and high‐field‐strength MR systems. J. Magn. Reson. Imaging 2001;14:763–770. © 2001 Wiley‐Liss, Inc.
Micro‐MR angiography of normal and intratumoral vessels in mice using dedicated intravascular MR contrast agents with high generation of polyamidoamine dendrimer core: Reference to pharmacokinetic properties of dendrimer‐based MR contrast agents
Authors: Kobayashi Hisataka , Kawamoto Satomi , Saga Tsuneo , Sato Noriko , Hiraga Akira , Konishi Junji , Togashi Kaori , Brechbiel Martin W. 
Published: August 2002

AbstractPharmacokinetic characteristics of intravascular macromolecular magnetic resonance imaging (MRI) contrast agents with polyamidoamine dendrimer cores smaller than generation‐7 were previously studied in the literature. To evaluate the effects of greater hepatic uptake on the pharmacokinetics of the larger generation dendrimers, the MRI contrast agents GxD‐(1B4M‐Gd) were synthesized with generation‐7, ‐8, and ‐9 polyamidoamine dendrimers and 2‐(p‐isothiocyanatobenzyl)‐6‐methyl‐diethylenetriaminepentaacetic acid (1B4M). Their pharmacokinetic characteristics in mice were compared with that of G6D‐(1B4M‐Gd)256. In biodistribution and dynamic micro‐MRI studies, significantly less renal accumulation of G7D‐(1B4M‐Gd)512, G8D‐(1B4M‐Gd)1024, and G9D‐(1B4M‐Gd)2048 was shown compared to G6D‐(1B4M‐Gd)256 (P < 0.01). There was a significantly greater accumulation of G8D‐(1B4M‐Gd)1024 and G9D‐(1B4M‐Gd)2048 in the liver compared to G6D‐(1B4M‐Gd)256 and G7D‐(1B4M‐Gd)512 (P < 0.01). The highest blood retention of all dendrimer‐based MRI contrast agents was exhibited by G7D‐(1B4M‐Gd)512 (P < 0.01). The normal and intratumoral fine vessels of approximately 100 μm diameter were visualized in normal or tumor‐bearing mice by high resolution three‐dimensional‐micro‐MR angiographs with G7D‐(1B4M‐Gd)512 and G8D‐(1B4M‐Gd)1024 with good vessel‐to‐soft tissue contrast. In summary, increased accumulation in the liver with concomitant decreased uptake in the kidney was caused by increased molecular sizes of the dendrimer‐based MRI contrast agents. J. Magn. Reson. Imaging 2001;14:705–713. © 2001 Wiley‐Liss, Inc.
Regional differences of fMR signal changes induced by hyperventilation: Comparison between SE‐EPI and GE‐EPI at 3‐T
Authors: Naganawa Shinji , Norris David G. , Zysset Stefan , Mildner Toralf 
Published: August 2002

AbstractPurposeTo evaluate whether reproducible signal change of brain tissues by hyperventilation (HV) can be seen on spin‐echo (SE)‐echo planar imaging (EPI) at 3‐T and to examine the sensitivity of SE‐EPI for measuring vascular reactivity in regions of the brain, such as the hippocampal formation, that are difficult to visualize with gradient‐echo (GE)‐EPI due to susceptibility artifacts.Materials and MethodsSix healthy human subjects performed a voluntary HV task. The task design was as follows: two minutes normal breathing (rest) followed by two minutes HV, giving a basic four‐minute block that was repeated three times for a total scan time of 12 minutes for one run. Each subject performed the run both for SE‐EPI and GE‐EPI. Statistical analysis was performed to detect the area with significant cerebrovascular reactivity. The percentage signal change was also obtained for each cerebral region.ResultsBoth GE‐EPI and SE‐EPI showed globally significant signal decreases in the cerebral cortex. In GE‐EPI, the frontal cortex showed a larger signal decrease than the other gray matter tissues (P < 0.05). In SE‐EPI, the differences among gray matter tissues except for the hippocampal formation were not significant. The hippocampal formation showed the largest signal change (P < 0.05) in SE‐EPI, but no significant signal change was observed in GE‐EPI due to the presence of susceptibility artifacts.Conclusion:HV using SE‐EPI at 3‐T provides robust and reproducible signal decreases and may make the evaluation of the vascular reactivity in hippocampal formation feasible. J. Magn. Reson. Imaging 2002;15:23–30. © 2002 Wiley‐Liss, Inc.
Pseudothrombosis with T2‐weighted fast spin‐echo MR images caused by static portal venous flow in severe cirrhosis
Authors: Matsuo Masayuki , Kanematsu Masayuki , Nishigaki Youichi , Kondo Hiroshi , Goshima Satoshi , Maeda Sunaho , Tomita Eiichi , Hoshi Hiroaki 
Published: August 2002

AbstractUnenhanced T2‐weighted fast spin‐echo images obtained in a 65‐year‐old woman with severe cirrhosis showed an area of high signal intensity occupying the left second‐order portal vein branch, suggesting portal vein thrombosis in cirrhosis. Doppler sonography, which revealed virtually no blood flow in the vessel, also supported the diagnosis. Gadolinium‐enhanced MRI subsequently revealed the patency of the vessel. The extremely slow portal venous flow was considered to be the cause of false‐positive findings with unenhanced MRI and sonography. J. Magn. Reson. Imaging 2002;15:199–202. © 2002 Wiley‐Liss, Inc.
Measurement of renal volumes with contrast‐enhanced MRI
Authors: Coulam Curtis H. , Bouley Donna M. , Sommer F. Graham 
Published: August 2002

AbstractPurposeTo determine the accuracy of in vivo magnetic resonance imaging (MRI) measurement of total renal parenchymal volume and medullary fraction.Materials and MethodsSixteen kidneys in eight pigs were imaged with a multiphasic contrast‐enhanced fast three‐dimensional sequence on a 1.5‐T imager. Kidney segmentation, followed by a process of signal intensity thresholding for cortical and nephrographic phase datasets, allowed for MRI measurements of parenchymal volume and medullary fraction. Autopsy provided reference standards of renal volume, weight, and medullary fraction.ResultsAn excellent correlation was found between MRI measurement of total renal parenchymal volume and autopsy volume (R2 = 0.86) and weight (R2 = 0.90). Medullary fraction (mean ± SD) measured with MRI was 0.120 ± 0.067, and with autopsy was 0.116 ± 0.025 (t‐test P = 0.84, F‐test P = 0.001).ConclusionMRI measurements of total renal volume are accurate. MRI measurements of medullary fraction show promise, but precision is limited when using a simple signal intensity thresholding algorithm. J. Magn. Reson. Imaging 2002;15:174–179. © 2002 Wiley‐Liss, Inc.
Effects of iodinated contrast and field strength on gadolinium enhancement: Implications for direct MR arthrography
Authors: Montgomery Douglas D. , Morrison William B. , Schweitzer Mark E. , Weishaupt Dominik , Dougherty Lawrence 
Published: August 2002

AbstractPurposeTo optimize direct magnetic resonance (MR) arthrography by determining the effect of dilution of gadolinium in iodinated contrast, saline, or albumin on T1‐weighted, T2‐weighted, and gradient‐recalled echo (GRE) images, and the effect of scanner field strength.Materials and MethodsGadopentetate dimeglumine was diluted into normal saline, albumin, or iodinated contrast (0.625 mmol/liter to 40 mmol/liter). Samples were scanned at 1.5T and 0.2T. Signal intensity was measured using T1‐weighted spin‐echo (SE), T2‐weighted SE, and two‐ and three‐dimensional GRE (20°–75° flip angle) sequences. Graphical analysis of signal intensity vs. gadolinium concentration was performed.ResultsAlbumin had no effect on gadolinium contrast. Dilution of gadolinium in iodinated contrast decreased signal intensity on all sequences compared to samples of identical concentration diluted in saline at both 1.5T and 0.2T: with a 2 mmol/liter gadolinium solution at 1.5T, signal was decreased by 26.1% on T1‐weighted images, 31.7% on GRE20 images, and 28.9% on GRE45 images, and the T2 value decreased by 71.1%; at 0.2T, signal was decreased by 23.5% on T1‐weighted images. On all sequences, the peak signal shifted to the left (lower gadolinium concentration) when diluted in iodinated contrast. Peak signal was also seen at different gadolinium concentrations on different sequences and field strength: at 1.5T, peak in saline/iodine was 2.5/0.625 mmol/liter on T1‐weighted images, and 2.5/1.25 mmol/liter on GRE20 and GRE45 sequences. At 0.2T, peak in saline/iodine was 0.625–2.5/1.25 mmol/liter on T1‐weighted images, 0.625–2.5/1.25 on GRE45 images, 2.5–10.0/1.25–5.0 mmol/liter on GRE65 images, and 1.25–5.0/0.625–1.25 mmol/liter on GRE75 images.ConclusionDilution of gadolinium in iodinated contrast results in decreased signal on T1‐weighted, T2‐weighted, and GRE images compared to dilution in saline or albuminfor both 1.5‐T and 0.2‐T scanners; if gadolinium is diluted in iodinated contrast for MR arthrography, a lower concentration should be used because the peak is shifted to the left. The use of iodinated contrast should be minimized, as it may diminish enhancement and lower the sensitivity and specificity of MR arthrography. Optimal gadolinium concentration for MR arthrography is dependent on scanner field strength and a broader range of gadolinium concentration can be used to provide maximal signal at low field strength. J. Magn. Reson. Imaging 2002;15:334–343. © 2002 Wiley‐Liss, Inc.
Role of magnetic resonance imaging in the diagnosis and monitoring of multiple sclerosis: Consensus report of the White Matter Study Group
Authors: Filippi M. , Dousset V. , McFarland H.F. , Miller D.H. , Grossman R.I. 
Published: August 2002

AbstractOn June 24–26, 2001, the first meeting of the White Matter Study Group (WMSG) of the International Society for Magnetic Resonance in Medicine (ISMRM) was held in Bordeaux, France. This paper is the report of the consensus reached among the delegates of the meeting on how to use magnetic resonance imaging (MRI) to make an early diagnosis of multiple sclerosis (MS), to measure MS activity accurately and reliably, and to monitor the effect of treatment on disease evolution. J. Magn. Reson. Imaging 2002;15:499–504. Published 2002 Wiley‐Liss, Inc.
Correlation of the apparent diffusion coefficient and the creatine level in early ischemic stroke: A comparison of different patterns by magnetic resonance
Authors: Rumpel Helmut , Khoo James B. K. , Chang Hui Meng , Lim Winston E. H. , Chen Christopher , Wong Meng Cheong , Tan Kim Ping 
Published: August 2002

AbstractIt has been reported that reduction of the apparent diffusion coefficient (ADC) after stroke can persist for several days, after which the ADC increases gradually to an abnormally high level. We evaluated ADC values of stroke lesions and compared the results to the cellular density of the lesion by means of the creatine (Cre) level. This two‐parameter estimation is of particular relevance in ascertaining the underlying cellular status. Lesion‐to‐contralateral ADC ratios (ADCn) were obtained based on diffusion‐weighted echo‐planar and fast spin‐echo imaging. Single‐voxel localized spectroscopy was used for quantification of cerebral metabolites in infarcted regions. Their levels were also compared to that in homotopic contralateral regions. Fifteen patients with ischemic stroke were examined at times ranging from 18–88 hours following the onset of symptoms. In the stroke lesion, there was a significant correlation between the ADC and the Cre level showing that the higher the cell density the lower the ADC value. For ADCn vs. the lesion Cre concentration and the lesion‐to‐contralateral Cre ratio (Cren), the strengths of relationship were R2 = 0.70 and 0.58, respectively. It is concluded that ADC is a good reflection of cell density. Greatly lowered ADC values occur within the context of a stable cellularity. ADC and the Cre level have complementary roles in the characterization of stroke lesion with regard to the sequential stage. J. Magn. Reson. Imaging 2001;13:335–343. © 2001 Wiley‐Liss, Inc.