bluuebunny/crossref_metadata_2025 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

Transition 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

13C‐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

Factors 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

The 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

Fore‐ 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

Elapids, 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

The 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

Prostate‐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

The 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

Pharmacokinetic 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

Purpose

To 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 Methods

Six 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.

Results

Both 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

Unenhanced 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

Purpose

To determine the accuracy of in vivo magnetic resonance imaging (MRI) measurement of total renal parenchymal volume and medullary fraction.

Materials and Methods

Sixteen 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.

Results

An 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).

Conclusion

MRI 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

Purpose

To 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 Methods

Gadopentetate 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.

Results

Albumin 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.

Conclusion

Dilution 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

On 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

It 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.
Evaluation of chondromalacia of the patella with axial inversion recovery–fast spin‐echo imaging
Authors: Lee Sang Hoon , Suh Jin‐Suck , Cho Jaemin , Kim Seong Joon , Kim Sung Jae
Published: August 2002

The purpose of our study was to assess the accuracy of inversion recovery–fast spin‐echo (IR‐FSE) imaging for the evaluation of chondromalacia of the patella. Eighty‐six patients were included, they underwent magnetic resonance (MR) examination and subsequent knee arthroscopy. Medial and lateral facets of the patella were evaluated separately. Axial images were obtained by using IR‐FSE (TR/TE/TI = 3000/25/150 msec; echo train length, 8; 4‐mm thickness; 12‐cm field of view; 512 × 256 matrix; two, number of excitations) with a 1.5‐T MR machine. MR interpretation of chondromalacia was made on the basis of the arthroscopic grading system. Of a total of 172 facets graded, arthroscopy revealed chondromalacia in 14 facets with various grades (G0, 158; G1, 1; G2, 3; G3, 6; G4, 4). Sensitivity, specificity, and accuracy in the chondromalacia grades were 57.1%, 93.0%, and 90.1%, respectively. There was one false‐negative case (G4) and 11 false‐positive cases (G1, eight; G2, two; G3, one). Sensitivity and specificity corrected by one grade difference were improved to 85.7% and 98.1%, respectively. When cartilage changes were grouped into early (corresponding to grade 1 and 2) and advanced (grade 3 and 4) diseases, sensitivity and specificity of the early and advanced diseases were 75% and 94% and 80% and 99%, respectively. IR‐FSE imaging of the knee revealed high specificity but low sensitivity for the evaluation of chondromalacia of the patella. J. Magn. Reson. Imaging 2001;13:412–416. © 2001 Wiley‐Liss, Inc.
Post‐radiotherapy contrast enhancement changes in fast dynamic MRI of cervical carcinoma
Authors: Boss Erik A. , Massuger Leon F.A.G. , Pop Luc A.M. , Verhoef Lia C.G. , Huisman Henk‐Jan , Boonstra Henk , Barentsz Jelle O.
Published: August 2002

This pilot study determines fast dynamic gadolinium enhanced MRI contrast enhancement parameters (onset of enhancement and time to peak enhancement) before and after radiotherapy in 10 cervical carcinoma patients. Before radiotherapy, onset of enhancement and time to peak enhancement were early, with a median of 4.5 and 5.2 seconds, respectively. High‐grade tumors showed early enhancement, compared with low‐grade. After radiotherapy, contrast enhancement patterns differed. In survivors, onset of enhancement after radiotherapy was later than before radiotherapy. In non‐survivors, onset of enhancement after radiotherapy was still early. The median difference in onset of enhancement before and after radiotherapy in survivors and non‐survivors was an increase of 3.2 and a decrease of 1.1 seconds, respectively. Early onset of enhancement after radiotherapy was a better predictor for survival than a high‐signal intensity zone on post radiotherapy unenhanced T1/T2‐weighted MRI. It is concluded that enhancement parameters from fast dynamic Gd‐enhanced MR images can provide additional functional information with regard to tumor vascularization, and may have prognostic significance. It complements clinical examination and unenhanced MRI in determining the effectiveness of radiotherapy treatment in cervical carcinoma. Future studies will focus on the clinical utility and improvements of the estimation of contrast‐enhanced parameters with this new technique. J. Magn. Reson. Imaging 2001;13:600–606. © 2001 Wiley‐Liss, Inc.
Effect of lung inflation on arterial spin labeling signal in MR perfusion imaging of human lung
Authors: Mai Vu M. , Chen Qun , Bankier Alexander A. , Blake Michael , Hagspiel Klaus D. , Knight‐Scott Jack , Berr Stuart S. , Edelman Robert R.
Published: August 2002

The effect of lung inflation on arterial spin‐labeling signal in lung perfusion is investigated. Arterial spin‐labeling schemes, called alternation of selective inversion pulse (ASI) and its hybrid (HASI), which uses blood water as an endogenous, freely diffusible tracer, were applied to magnetic resonance (MR) perfusion imaging of the lung. Perfusion‐weighted images of the lung from nine healthy volunteers were obtained at different time delays. There was a significant signal difference in ASI images acquired at different respiratory phases. Greater signal enhancement has been observed when the volunteers performed breath holding on end expiration than on end inspiration. This is in agreement with the normal physiologic effect of lung inflation on the pressure‐flow relationship of pulmonary vasculature. ASI and HASI perfusion‐weighted images show similar lung features and image quality. Preliminary results from pulmonary embolism patients indicate that arterial spin labeling is sensitive for the detection of areas of perfusion deficit. J. Magn. Reson. Imaging 2001;13:954–959. © 2001 Wiley‐Liss, Inc.
A multielement RF coil for MRI guidance of interventional devices
Authors: Zhang Qiang , Wendt Michael , Aschoff Andrik J. , Lewin Jonathan S. , Duerk Jeffrey L.
Published: August 2002

Accurate localization of minimally invasive devices is critical to the success of interventional procedures. Device orientation and tip position are two of the most important pieces of information needed to define device location for magnetic resonance imaging (MRI)‐guided interventional procedures. While a single one‐element micro coil incorporated into an interventional device has proven to be effective in some applications, it can only supply tip position information. However, multiple positions on the device are necessary to also determine its orientation. For this purpose, a novel single micro coil design with three separate winding elements that provides both the device orientation and tip position is described in this study. Definition of MR scan planes, by using the device orientation and the target tissue location, permits automatic tracking of the insertion of the device. Furthermore, devices that include this coil design are permitted to bend to a limited extent. This makes the micro coil design appropriate for many flexible interventional devices. Reliable near‐real‐time tracking of three points on an interventional device is demonstrated on a 0.2T MRI system with modest gradient performance. Phantom and in vivo animal experiments are used to demonstrate the utility of this new coil design. J. Magn. Reson. Imaging 2001;14:56–62. © 2001 Wiley‐Liss, Inc.
Moving‐table reduced‐dose gadolinium‐enhanced three‐dimensional magnetic resonance angiography: Velocity‐dependent method with three‐phase gadolinium infusion
Authors: Kita Miho , Mitani Yasuyuki , Tanihata Hirohiko , Kita Keisuke , Sato Morio , Takizawa Osamu , Laub Gerhard
Published: August 2002

The purpose of this study was to develop a method for reducing gadolinium dose and suppressing venous overlap in moving‐table three‐dimensional (3D) magnetic resonance (MR) angiography from the abdomen to the feet. Thirty‐one patients underwent three‐phase infusion of 16–18 mL of gadolinium: infusion rates and imaging times were determined after taking into account mean blood flow velocity, so that image acquisition was synchronized with peak arterial enhancement at both the first and third stations (velocity‐dependent method). Twenty‐three other patients underwent slow infusion of 38 mL of gadolinium with fixed acquisition time (high‐dose method). The image quality for the two methods was compared. The velocity‐dependent method produced good image quality with significantly less venous overlap than the high‐dose method, especially in the below‐the‐knee region (P < .001). The velocity‐dependent method provides satisfactory MR angiograms using 16–18 mL of gadolinium in patients having various blood flow velocities. J. Magn. Reson. Imaging 2001;14:319–328. © 2001 Wiley‐Liss, Inc.
Dobutamine stress cine‐MRI of cardiac function in the hearts of adult cardiomyocyte‐specific VEGF knockout mice
Authors: Williams Simon‐Peter , Gerber Hans‐Peter , Giordano Frank J. , Peale Franklin V. , Bernstein Lisa J. , Bunting Stuart , Chien Kenneth R. , Ferrara Napoleone , van Bruggen Nicholas
Published: August 2002

A mouse model of non‐necrotic vascular deficiency in the adult heart was studied using cine‐magnetic resonance imaging (MRI) and other techniques. The mice lacked cardiomyocyte‐derived vascular endothelial growth factor (VEGF) following a targeted knockout in the ventricular cardiomyocytes. Quantitative endothelial labeling showed that the capillary density was significantly reduced in the hearts of knockout mice. Gene expression patterns suggested that they were hypoxic. Semiautomated MR image analysis was employed to obtain both global and regional measurements of left ventricular function at 10 or more time points through the cardiac cycle. MRI measurements showed a marked reduction in ejection fraction both at rest and under low‐ and high‐dose dobutamine stress. Regional wall thickness, thickening, and displacement were all attenuated in the knockout mice. A prolonged high‐dose dobutamine challenge was monitored by MRI. A maximal response was sustained for 90 minutes, suggesting that it did not depend on endogenous glycogen stores. J. Magn. Reson. Imaging 2001;14:374–382. © 2001 Wiley‐Liss, Inc.
Three‐dimensional MR pulmonary perfusion imaging and angiography with an injection of a new blood pool contrast agent B‐22956/1
Authors: Zheng Jie , Carr James , Harris Katherine , Saker Mark B. , Cavagna Friedrich M. , Maggioni Fabio , Laub Gerhard , Li Debiao , Finn J. Paul
Published: August 2002

Initial evaluation of a new blood pool agent, B‐22956/1, for pulmonary imaging was performed in five domestic pigs with artificial embolism. Pre‐embolism 3D pulmonary perfusion images were first acquired by injecting an extravascular agent, gadoteridol. The pulmonary arteries of the pigs were then occluded by the artificial emboli. Post‐embolism perfusion scans were subsequently performed by injecting B‐22956/1. Additional post‐embolism high‐spatial‐resolution angiograms were also acquired. Parenchyma perfusion deficits were well depicted in the post‐embolism perfusion maps. The post‐embolism angiography clearly revealed the location and extent of the filling defects in the pulmonary vessels. Signal intensities of perfusion maps on the normal parenchyma were significantly improved (30%) by using B‐22956/1, in comparison with perfusion images using gadoteridol (P < 0.01). Many pulmonary angiograms with approximately equal contrast could be obtained even at 22 minutes after the injection of B‐22956/1. Our initial results indicate that blood pool agent B‐22956/1 may provide opportunities for whole‐lung‐coverage perfusion mapping and additional high‐resolution target angiograms after a single injection. J. Magn. Reson. Imaging 2001;14:425–432. © 2001 Wiley‐Liss, Inc.
Time‐to‐echo optimization for spin echo magnetic resonance imaging of liver metastasis using superparamagnetic iron oxide particles
Authors: Alger Jeffry R. , Harreld Julie H. , Chen Sloane , Mintorovitch Jan , Lu David S.K.
Published: August 2002

Superparamagnetic iron oxide (SPIO) particles are used as a contrast agent in liver magnetic resonance imaging (MRI). SPIO particles exert their greatest influence on T2‐weighted MR signal intensity. The time‐to‐echo (TE) value that provides optimal contrast has not been systematically studied over the range of clinically relevant field strengths. The purpose of this study was to quantitatively evaluate the TE dependence of the post‐SPIO tumor to liver contrast‐to‐noise ratio (CNR). The hypothesis was that there is a TE that provides an optimal CNR. Subjects having probable metastatic hepatic lesions secondary to colorectal carcinoma were studied. Pre‐ and post‐SPIO images were acquired at TE‐effective (TEeff) equal to 46, 76, and 106 msec by using a turbo spin echo pulse sequence at 0.2 T and 1.5 T. The CNR for all lesions greater than 1 cm in diameter was determined in pre‐ and post‐SPIO images. A paired statistical design was used to identify TE‐related CNR dependencies. The primary findings were as follows. (1) CNR differences attributable to TEeff variation over the range of 46–106 msec were less than 34%. For 0.2 T, TEeff = 46 msec yielded a statistically significantly greater CNR than did TEeff = 76 or 106 msec. The same was true at the higher field strength, but differences were not significant. (2) Signal‐to‐noise measures suggested that SPIO reduced the lesion signal. (3) Post‐SPIO CNR was significantly greater at 1.5 T than at 0.2 T. The observations indicate that over the field strength range of 0.2–1.5 T, CNR differences attributable to the TEeff variation, while being statistically significant in some cases, are small relative to those resulting from the SPIO administration. J. Magn. Reason. Imaging 2001;14:586–594, 2001. © 2001 Wiley‐Liss, Inc.
T1 measurements in cell cultures: A new tool for characterizing contrast agents at 1.5T
Authors: Schmalbrock Petra , Hines Jennifer V. , Lee Shu‐Ming , Ammar Ghada M. , Kwok Edmund Wing‐Chi
Published: August 2002

The objective of this work was to assess the feasibility and accuracy of T1 and relaxivity measurements in cell cultures using 1.5T magnetic resonance imaging (MRI) with the long‐term goal to develop a tool for evaluation of novel paramagnetic agents in a realistic macromolecular environment. This initial study was carried out using MCF‐7 cells treated with independently determined concentrations of Gd‐DTPA. Two cell culture systems were evaluated: cell pellets and single layers of cells grown on microporous inserts. High‐resolution T1 measurements of cell cultures were acquired with two dimensional Inversion Recovery Fast Spin Echo (2D‐IR‐FSE), three dimensional Inversion Recovery Fast Spin Echo (3D‐IR‐FSE), and 3D‐SPGR sequences. The T1 and relaxivity accuracy of these sequences was confirmed with aqueous Gd‐DTPA samples of known concentration. Relaxivities of 1.71 ± 0.15 [mM−1second−1] and 1.55 ± 0.50 [mM−1second−1] were measured in the cell pellets and cell monolayers, respectively, and were different from the value of 4.3 [mM−1second−1] for Gd‐DTPA in water. Both cell pellets and monolayers are suitable for initial assessment of novel MR contrast agents. J. Magn. Reson. Imaging 2001;14:636–648. © 2001 Wiley‐Liss, Inc.
Electrospray tandem mass spectrometric study of ferrocene carbamate ester derivatives of saturated primary, secondary and tertiary alcohols
Authors: Quirke J. Martin E. , Van Berkel Gary J.
Published: August 2002

The fragmentation pathways and mechanisms for 27 ferrocene carbamate esters of saturated alkyl primary, secondary and tertiary alcohols were investigated using energy‐resolved electrospray tandem mass spectrometry (ES‐MS/MS). The mechanisms that control the formation and abundance of the three product ions common to all the derivatives, which appear at m/z 201, 227 and 245, were elucidated. Plotting the relative abundances of the three product ions versus a range of center‐of‐mass collision energies provided a graphical representation of the behavior of the fragmentation process that was directly comparable from compound to compound. As a result, it was possible to compare product ion spectra of the different derivatives to distinguish among different alcohol structural types. Straight‐chain primary alcohols were easily distinguished from tertiary alcohols. Both of these structural types, including positional isomers, produced product ion spectra that were distinct from those of β‐branched primary alcohols, or acyclic secondary alcohols or cyclic secondary alcohols. The latter three alcohol types display similar product ion spectra and therefore cannot be distinguished from one another on the basis of these spectra alone. Published in 2001 by John Wiley & Sons, Ltd.
Determination of polychlorodibenzo‐p‐dioxins and polychlorodibenzofurans by gas chromatography/tandem mass spectrometry and gas chromatography/triple mass spectrometry in a quadrupole ion trap
Authors: Helen C. , Lemasle M. , Laplanche A. , Genin E.
Published: August 2002

The determination of tetra‐ to octachlorodibenzo‐p‐dioxins and tetra‐ to octachlorodibenzofurans (PCCD/Fs) by high‐resolution gas chromatography/tandem mass spectrometry (HRGC/MS/MS) and high‐resolution gas chromatography/triple mass spectrometry (HRGC/MS3) in a quadrupole ion trap, equipped with an external ion source, is presented. MS/MS involves a typical four‐step process, namely ionization, parent ion isolation, collision‐induced dissociation (CID) and mass analysis of the daughter ions. For the MS3 experiment, the MS/MS scan function is used with the addition of selected daughter ion isolation, their CID and the mass analysis of second‐generation product ions called ‘grand‐daughter ions.’ For both methods, the energies necessary for the CID of the 17 PCDD/Fs were determined and optimized using multiple scan functions with different CID amplitudes. The CID efficiency, defined as the signal ratio of fragment ions detected from the major dissociation channels to molecular ions isolated, was 1.15–2.40 V for parent ion dissociation (MS/MS) and 1.05–1.50 V for daughter ion dissociation (MS3) and for all the chloro congeners. The same sensitivity (1 pg µl−1) can be reached with both the MS/MS and MS3 methods and linear responses were obtained between 1 and 100 pg µl−1 injected. Copyright © 2001 John Wiley & Sons, Ltd.
Structure characterization of flavonoid O‐diglycosides by positive and negative nano‐electrospray ionization ion trap mass spectrometry
Authors: Cuyckens Filip , Rozenberg Raoul , de Hoffmann Edmond , Claeys Magda
Published: August 2002

Isomeric flavonoid O‐diglycosides were analyzed by positive and negative nano‐electrospray ionization (ESI) ion trap mass spectrometry (ITMS) in order to evaluate whether the two most common interglycosidic linkage types, i.e. 1 → 2 and 1 → 6, found for glycosides containing a rhamnosylglucose glycan part can be differentiated. In the positive ion mode the degree of internal glucose residue loss was found to be strongly dependent on the aglycone type and was very pronounced for aglycones of the flavanone type. The relative abundance of the Y‐type ions formed by fragmentation at glycosidic bonds only allows one to infer the interglycosidic linkage types in the case of flavone O‐diglycosides. In contrast, the negative ion mode makes a clear differentiation between a rutinoside (1 → 6) and a neohesperidoside (1 → 2) glycan residue possible for all aglycone types. The neohesperidose‐containing compounds could be characterized by additional product ions. When the compounds were dissolved in pure methanol a molecular radical ion was found to be the base peak in nano‐ESI. Copyright © 2001 John Wiley & Sons, Ltd.
A B‐TOF mass spectrometer for the analysis of ions with extreme high start‐up energies
Authors: Lezius M.
Published: August 2002

Weak magnetic deflection is combined with two acceleration stage time‐of‐flight mass spectrometry and subsequent position‐sensitive ion detection. The experimental method, called B‐TOF mass spectrometry, is described with respect to its theoretical background and some experimental results. It is demonstrated that the technique has distinct advantages over other approaches, with special respect to the identification and analysis of very highly energetic ions with an initially large energy broadening (up to 1 MeV) and with high charge states (up to 30+). Similar energetic targets are a common case in intense laser–matter interaction processes found during laser ablation, laser–cluster and laser–molecule interaction and fast particle and x‐ray generation from laser‐heated plasma. Copyright © 2002 John Wiley & Sons, Ltd.
Sequence evolution and cross‐reactive antibody responses to hypervariable region 1 in acute hepatitis C virus infection*
Authors: Hjalmarsson Sandra , Blomberg Jonas , Grillner Lena , Pipkorn Rüdiger , Allander Tobias
Published: August 2002

Hepatitis C virus (HCV) infection may result in acute resolving or chronic infection. Patients that clear the infection have a more vigorous cellular immune response and an early humoral response to the hypervariable region 1 (HVR1) of the E2 envelope protein. To analyse further the properties of the early anti‐HVR1 response, cross‐reactivity of anti‐HVR1 responses was assessed in five patients with acute HCV infection, who were infected by the same virus strain during a nosocomial outbreak . The sequence evolution of HVR1 was examined in sequential serum samples up to 37 months post infection. Peptides were synthesised corresponding to the obtained HVR1 sequences and unrelated HVR1 sequences, and antibody reactivity to the peptides in sequential sera was investigated by ELISA. The results suggest an association between specific gaps in humoral immunity and the HVR1 sequence evolution during early infection. Possible interpretations of this phenomenon include immune escape mechanisms or suppression of specific anti‐HVR1 antibodies. J. Med. Virol. 64:117–124, 2001. © 2001 Wiley‐Liss, Inc.
Genetic analysis of recent Taiwanese isolates of a variant of coxsackievirus A24
Authors: Lin Kuei‐Hsiang , Chern Chi‐Liang , Chu Pei‐Yu , Chang Cheng‐Hsien , Wang Heng‐Lin , Sheu Min‐Muh , Huang Wen‐Loong , Pongsuwanna Yaowapa , Yamamoto Seigo , Yoshino Syuji , Ishiko Hiroaki , Takeda Naokazu
Published: August 2002

Epidemics of acute hemorrhagic conjunctivitis (AHC) caused by a variant of coxsackievirus A24 (CA24v) reappeared in Taiwan in 1990 and 1994, following the first two epidemics of 1985–86 and 1988–89. To analyze the genetic diversity of recent CA24v in Taiwan, 7 Taiwanese strains isolated during the 1990–94 period were studied together with one Japanese and two Thai strains isolated in 1993. A fragment of 674 nucleotides between the carboxy terminal 3A and the amino terminal 3D polymerase, including the entire 3C protease (3Cpro), was amplified by a reverse transcription‐polymerase chain reaction (RT‐PCR) and the nucleotide sequences were determined. In the 549 nucleotides (183 amino acids) of the entire 3Cpro, we found nucleotide differences at 80 positions between 10 strains and the prototype strain, EH24/70, one of the earliest strains of CA24v. Most of the nucleotide changes were synonymous substitutions and only nine amino acid changes were found. The nucleotide sequence homologies among 71 strains worldwide were 88–100%. These 71 nucleotide sequences were then analyzed by Neighbor‐joining method and phylogenetically separated into three distinct genotypes. Genotype I consisted of early strains isolated in 1970–71 from Singapore and Hong Kong. Genotype II included isolates from Singapore and Thailand obtained in 1975. Genotype III comprised strains from the eastern hemisphere isolated in 1985–94 from Japan, Taiwan, China, Hong Kong, Thailand, Singapore, Pakistan and Ghana. They were further divided chronologically into six clusters. The recent isolates from Taiwan obtained in 1985/1986, 1988/1989 and 1990–94 were classified into genotype III Clusters 1, 5, and 6 respectively. The evolutionary rate was re‐estimated to be 3 × 10− 3 30 years after the emergence of the virus. J. Med. Virol. 64:269–274, 2001. © 2001 Wiley‐Liss, Inc.
Epidemic of adenovirus‐induced respiratory illness among US military recruits: Epidemiologic and immunologic risk factors in healthy, young adults*†
Authors: Sanchez Jose L. , Binn Leonard N. , Innis Bruce L. , Reynolds Richard D. , Lee Terrence , Mitchell‐Raymundo Felicia , Craig Stephen C. , Marquez Jeffrey P. , Shepherd Greg A. , Polyak Christina S. , Conolly Johnnie , Kohlhase Kimmie F.
Published: August 2002

Adenovirus (Ad)‐induced acute respiratory illnesses resurged among civilian adults and selected military training populations in the United States during the late 1990s. We examined the epidemiologic and immunologic correlates of Ad‐induced respiratory illnesses during a large outbreak at an Army basic training installation in southeast United States during a 9‐day period in November 1997. A total of 79 recruits hospitalized with acute respiratory illnesses were evaluated during the outbreak period; confirmation of Ad infection by isolation of Ad‐like cytopathic agents from throat cultures was detected in 71 (90%) of these patients. Serotyping of 19 (27%) of these 71 isolates identified the etiologic agent to be Ad type 4 (Ad4). In addition, 30 (81%) of 37 patients in whom paired sera were collected demonstrated significant increases (i.e., 4‐fold or higher) in serum anti‐Ad4 neutralizing antibodies. Anti‐Ad4 immunity in new recruits was found to be very low (15 to 22%). A case‐control study involving 66 of the 79 hospitalized cases and 189 non‐ill controls from the same units was conducted. A lower risk of hospitalization for acute respiratory illnesses was documented for female recruits (odds ratio[OR] = 0.47, P < .05) whereas, a higher risk was noted for smokers (OR = 1.89, P < .05). Unit (training company) attack rates as high as 8 to 10% per week were documented and the outbreak quickly subsided after live, oral Ad types 4 and 7 vaccination was resumed in November 1997. Re‐establishment of a military Ad vaccination program is critical for control of Ad‐induced acute respiratory illnesses. J. Med. Virol. 65:710–718, 2001. © 2001 Wiley‐Liss, Inc.