bluuebunny/crossref_metadata_2025 huggingface dataset:
Pattern recognition strategies for molecular surfaces. II. Surface complementarity
Authors: Exner Thomas E. , Keil Matthias , Brickmann Jürgen
Published: August 2002

Fuzzy logic based algorithms for the quantitative treatment of complementarity of molecular surfaces are presented. Therein, the overlapping surface patches defined in article I1 of this series are used. The identification of complementary surface patches can be considered as a first step for the solution of molecular docking problems. Standard technologies can then be used for further optimization of the resulting complex structures. The algorithms are applied to 33 biomolecular complexes. After the optimization with a downhill simplex method, for all these complexes one structure was found, which is in very good agreement with the experimental results. © 2002 Wiley Periodicals, Inc. J Comput Chem 23: 1188–1197, 2002
Definitive heat of formation of methylenimine, CH2NH, and of methylenimmonium ion, CH2NH2+, by means of W2 theory
Authors: de Oliveira Glênisson , Martin Jan M. L. , Silwal Indira K. C. , Liebman Joel F.
Published: August 2002

A long‐standing controversy concerning the heat of formation of methylenimine has been addressed by means of the W2 (Weizmann‐2) thermochemical approach. Our best calculated values, ΔH°f,298(CH2NH) = 21.1±0.5 kcal/mol and ΔH°f,298(CH2NH2+) = 179.4±0.5 kcal/mol, are in good agreement with the most recent measurements but carry a much smaller uncertainty. As a byproduct, we obtain the first‐ever accurate anharmonic force field for methylenimine: upon consideration of the appropriate resonances, the experimental gas‐phase band origins are all reproduced to better than 10 cm−1. Consideration of the difference between a fully anharmonic zero‐point vibrational energy and B3LYP/cc‐pVTZ harmonic frequencies scaled by 0.985 suggests that the calculation of anharmonic zero‐point vibrational energies can generally be dispensed with, even in benchmark work, for rigid molecules. © 2001 John Wiley & Sons, Inc. J Comput Chem 22: 1297–1305, 2001
Computational studies of reaction mechanisms of methane monooxygenase and ribonucleotide reductase
Authors: Torrent Maricel , Musaev Djamaladdin G. , Basch Harold , Morokuma Keiji
Published: August 2002

An overview of the computational efforts made by our group during the last few years in the field of nonheme diiron proteins is presented. Through application of ab initio methodology to a reasonable set of molecular models, significant progress is made in understanding how the soluble Methane Monooxygenase system achieves the hydroxylation of methane and how the catalytic cycle of Ribonucleotide Reductase is initiated. In particular, the current studies reveal in more detail (1) the nature of key intermediates in the reaction cycles of these two metalloenzymes, (2) details of how the iron centers regulate the systems, and (3) important aspects of how the carboxylate ligands in the active sites may tailor the enzymatic needs of the metalloprotein. This knowledge also leads to novel connections between the two enzymes. The coordinative unsaturation and carboxylate shifts investigated herein are two properties that are likely to be of more general impact in nonheme proteins. The control of the redox chemistry of the enzyme by the binuclear metal center, also analyzed here, should find common ground among other bimetallic systems as well. © 2002 Wiley Periodicals, Inc. J Comput Chem 23: 59–76, 2002
Rapid grid‐based construction of the molecular surface and the use of induced surface charge to calculate reaction field energies: Applications to the molecular systems and geometric objects
Authors: Rocchia Walter , Sridharan Sundaram , Nicholls Anthony , Alexov Emil , Chiabrera Alessandro , Honig Barry
Published: August 2002

This article describes a number of algorithms that are designed to improve both the efficiency and accuracy of finite difference solutions to the Poisson–Boltzmann equation (the FDPB method) and to extend its range of application. The algorithms are incorporated in the DelPhi program. The first algorithm involves an efficient and accurate semianalytical method to map the molecular surface of a molecule onto a three‐dimensional lattice. This method constitutes a significant improvement over existing methods in terms of its combination of speed and accuracy. The DelPhi program has also been expanded to allow the definition of geometrical objects such as spheres, cylinders, cones, and parallelepipeds, which can be used to describe a system that may also include a standard atomic level depiction of molecules. Each object can have a different dielectric constant and a different surface or volume charge distribution. The improved definition of the surface leads to increased precision in the numerical solutions of the PB equation that are obtained. A further improvement in the precision of solvation energy calculations is obtained from a procedure that calculates induced surface charges from the FDPB solutions and then uses these charges in the calculation of reaction field energies. The program allows for finite difference grids of large dimension; currently a maximum of 5713 can be used on molecules containing several thousand atoms and charges. As described elsewhere, DelPhi can also treat mixed salt systems containing mono‐ and divalent ions and provide electrostatic free energies as defined by the nonlinear PB equation. © 2002 Wiley Periodicals, Inc. J Comput Chem 23: 128–137, 2002
Validity of the pediatric inpatient behavior scale in an inpatient psychiatric setting
Authors: Kronenberger William G. , Causey David , Carter Bryan D.
Published: August 2002

Standardized assessment of children's behavior during psychiatric hospitalization is increasingly important for evaluation, chart documentation, treatment planning, and outcome monitoring, yet little research has been done to validate the use of behavior checklists developed specifically to assess in‐hospital behavior. The Pediatric Inpatient Behavior Scale (PIBS) was evaluated for its validity as a measure of behavior of children hospitalized on a psychiatric unit. Nurses completed the PIBS for 41 children, based on behavior observed during the first week of hospitalization. DSM‐IV diagnoses and major symptoms were coded based on chart review, and children completed self‐report measures of depression and anxiety. The Pediatric Inpatient Behavior Scale subscale scores were related significantly to diagnosis, as well as to major symptoms, correctly classifying 75 to 85% of cases. The Pediatric Inpatient Behavior Scale subscale scores also significantly correlated with self‐reported symptoms of depression, but not symptoms of state anxiety. Results support the use of the PIBS as a behavioral instrument for hospitalized children with severe psychopathology. © 2001 John Wiley & Sons, Inc. J Clin Psychol 57: 1421–1434, 2001.
EMDR: A putative neurobiological mechanism of action
Authors: Stickgold Robert
Published: August 2002

Numerous studies have provided evidence for the efficacy of eye movement desensitization and reprocessing therapy (EMDR) in the treatment of posttraumatic stress disorder (PTSD), including recent studies showing it to be more efficient than therapist‐directed flooding. But few theoretical explanations of how EMDR might work have been offered. Shapiro, in her original description of EMDR, proposed that its directed eye movements mimic the saccades of rapid eye movement sleep (REM), but provided no clear explanation of how such mimicry might lead to clinical improvement. We now revisit her original proposal and present a complete model for how EMDR could lead to specific improvement in PTSD and related conditions. We propose that the repetitive redirecting of attention in EMDR induces a neurobiological state, similar to that of REM sleep, which is optimally configured to support the cortical integration of traumatic memories into general semantic networks. We suggest that this integration can then lead to a reduction in the strength of hippocampally mediated episodic memories of the traumatic event as well as the memories' associated, amygdala‐dependent, negative affect. Experimental data in support of this model are reviewed and possible tests of the model are suggested. © 2002 John Wiley & Sons, Inc. J Clin Psychol 58: 61–75, 2002.
Involvement of the cardiac ryanodine receptor/calcium release channel in catecholaminergic polymorphic ventricular tachycardia
Authors: Marks Andrew R. , Priori Silvia , Memmi Mirella , Kontula Kimmo , Laitinen Päivi J.
Published: August 2002

The cardiac ryanodine receptor (RyR2), the major calcium release channel on the sarcoplasmic reticulum (SR) in cardiomyocytes, has recently been shown to be involved in at least two forms of sudden cardiac death (SCD): (1) Catecholaminergic polymorphic ventricular tachycardia (CPVT) or familial polymorphic VT (FPVT); and (2) Arrhythmogenic right ventricular dysplasia type 2 (ARVD2). Eleven RyR2 missense mutations have been linked to these diseases. All eleven RyR2 mutations cluster into 3 regions of RyR2 that are homologous to the three malignant hyperthermia (MH)/central core disease (CCD) mutation regions of the skeletal muscle ryanodine receptor/calcium release channel RyR1. MH/CCD RyR1 mutations have been shown to alter calcium‐induced calcium release. Sympathetic nervous system stimulation leads to phosphorylation of RyR2 by protein kinase A (PKA). PKA phosphorylation of RyR2 activates the channel. In conditions associated with high rates of SCD such as heart failure RyR2 is PKA hyperphosphorylated resulting in “leaky” channels. SR calcium leak during diastole can generate “delayed after depolarizations” that can trigger fatal cardiac arrhythmias (e.g., VT). We propose that RyR2 mutations linked to genetic forms of catecholaminergic‐induced SCD may alter the regulation of the channel resulting in increased SR calcium leak during sympathetic stimulation. J. Cell. Physiol. 190: 1–6, 2002. © 2002 Wiley‐Liss, Inc.
Distinct physiological roles of the Gq‐coupled metabotropic glutamate receptors co‐expressed in the same neuronal populations
Authors: Valenti Ornella , Conn P. Jeffrey , Marino Michael J.
Published: August 2002

The group I metabotropic glutamate receptors, mGluR1 and mGluR5, exhibit a high degree of sequence homology, and are often found co‐expressed in the same neuronal populations. These receptors couple to a broad array of effector systems, and are implicated in diverse physiological and pathophysiological functions. Due to the high degree of sequence homology, and the findings that these receptors couple identically in recombinant systems, it has been generally assumed that these two group I mGluR subtypes would exhibit redundant function when co‐expressed in the same neurons. With the advent of subtype‐selective pharmacological tools, it has become possible to tease apart the functions of mGluR1 and mGluR5 in the same neuron. The emerging picture is one of diverse function, which implies differential regulation. Interestingly, the group I mGluRs are modulated by a rich variety of regulatory systems, which may explain how these receptors can mediate divergent actions when present in the same cell. J. Cell. Physiol. 191: 125–137, 2002. © 2002 Wiley‐Liss, Inc.
Surface protein characterization of human adipose tissue‐derived stromal cells
Authors: Gronthos Stan , Franklin Dawn M. , Leddy Holly A. , Robey Pamela G. , Storms Robert W. , Gimble Jeffrey M.
Published: August 2002

Human bone marrow stromal cells are a multipotent population of cells capable of differentiating into a number of mesodermal lineages as well as supporting hematopoeisis. Their distinct protein and gene expression phenotype is well characterized in the literature. Human adipose tissue presents an alternative source of multipotent stromal cells. In this study, we have defined the phenotype of the human adipose tissue‐derived stromal cells in both the differentiated and undifferentiated states. Flow cytometry and immunohistochemistry show that human adipose tissue‐derived stromal cells have a protein expression phenotype that is similar to that of human bone marrow stromal cells. Expressed proteins include CD9, CD10, CD13, CD29, CD34, CD44, CD 49d, CD 49e, CD54, CD55, CD59, CD105, CD106, CD146, and CD166. Expression of some of these proteins was further confirmed by PCR and immunoblot detection. Unlike human bone marrow‐derived stromal cells, we did not detect the STRO‐1 antigen on human adipose tissue‐derived stromal cells. Cells cultured under adipogenic conditions uniquely expressed C/EBPα and PPARδ, two transcriptional regulators of adipogenesis. Cells cultured under osteogenic conditions were more likely to be in the proliferative phases of the cell cycle based on flow cytometric analysis of PCNA and Ki67. The similarities between the phenotypes of human adipose tissue‐derived and human bone marrow‐derived stromal cells could have broad implications for human tissue engineering. © 2001 Wiley‐Liss, Inc.
Recovery of tartaric acid from industrial enological wastes
Authors: Versari Andrea , Castellari Massimo , Spinabelli Umberto , Galassi Sergio
Published: August 2002

The recovery of tartaric acid (TA) from three industrial enological wastes: (i) cream of tartar, (ii) lees, and (iii) eluates from the regeneration of anion exchange resins used for the production of grape liquid sugar, was studied. Recovery of TA ranged between 58 and 99%, the highest being from cream of tartar. The level of addition of calcium salts is important to improve the recovery of calcium tartrate from lees and eluates. A significant inverse correlation between TA recovery and the percentage of organic acids, except for tartaric acid, was found; this index may help to optimize the level of calcium addition. Enological eluates would represent a commercial source of malic acid (recovery of 51%).

© 2001 Society of Chemical Industry
Advanced oxidation processes for the degradation of p‐hydroxybenzoic acid 1: Photo‐assisted ozonation
Authors: Beltran J , Torregrosa J , Dominguez J R , Peres J A
Published: August 2002

The oxidation of p‐hydroxybenzoic acid in aqueous solution by UV radiation and by photo‐assisted ozonation (UV+O3) has been studied. The effects of temperature (10, 20, 30 and 40 °C), pH (2, 5, 7 and 9) and ozone partial pressure (0.10–0.38 kPa) on the conversion of p‐hydroxybenzoic acid were established. Experimental results indicated that the kinetics for both oxidation processes fit pseudo‐first‐order kinetics well. In the combined process, the overall kinetic rate constant was split into two components: direct oxidation by UV radiation (photolysis) and oxidation by free radicals (mainly OH·) generated in the system. The importance of these two reaction paths for each specific value of ozone partial pressure, temperature and pH was quantified. Lastly, a general expression is proposed for the reaction rate which takes into account the two reaction pathways and is a function of known operating variables.

© 2001 Society of Chemical Industry
Changes in blood flow velocity in the middle and anterior cerebral arteries evoked by walking
Authors: Nedeltchev Krassen , Arnold Marcel , Nirkko Arto , Sturzenegger Mathias , Rihs Frank , Bühler Robert , Mattle Heinrich P.
Published: August 2002

Purpose

Transcranial Doppler sonography (TCD) is an established method for assessing changes in blood flow velocity (BFV) coupled to brain activity. Our objective was to investigate whether walking induces measurable changes in BFV in healthy subjects.

Methods

Changes in BFV in both middle cerebral arteries (MCAs) of 40 healthy adult subjects during walking on a treadmill were measured using bilateral TCD. In 8 of the 40 subjects, 1 anterior cerebral artery (ACA) was monitored simultaneously with the contralateral MCA. The percentage increase in BFV (BFVI%) compared with the baseline velocity (V0), the percentage decrease in BFV (BFVD%) compared with the V0, and the normalized ACA‐MCA ratio were analyzed.

Results

The overall mean (± standard deviation [SD]) V0 was 59.9 ± 11.6 cm/second in the left MCA and 60.1 ± 12.9 cm/second in the right MCA. Women had higher V0 values than men had. Walking evoked an initial mean overall BFVI% in both left (8.4 ± 5.1%) and right MCAs (9.1 ± 5.1%), followed by a decrease to below baseline values in 38 of 40 subjects. A statistically significant increase of the normalized ACA‐MCA ratio was measured, indicating that changes in BFV in the ACA territory were coupled to brain activation during walking.

Conclusions

The use of functional TCD showed different changes in BFV in the ACAs and MCAs during walking. This method may be an interesting tool for monitoring progress in patients with motor deficits of the legs, such as paresis. © 2002 Wiley Periodicals, Inc. J Clin Ultrasound 30:132–138, 2002; DOI 10.1002/jcu.10047
Role of sonography in the diagnosis of gallbladder perforation
Authors: Sood Bimal P. , Kalra Naveen , Gupta Sanjay , Sidhu Ravinder , Gulati Madhu , Khandelwal Niranjan , Suri Sudha
Published: August 2002

Purpose

Gallbladder perforation is a dreaded complication of acute cholecystitis that is associated with a high mortality rate. Early detection of gallbladder perforation reduces the associated mortality and morbidity rates. The purpose of this study was to highlight the role of sonography in the diagnosis of gallbladder perforation and to compare the diagnostic accuracy of sonography with that of CT.

Methods

We retrospectively evaluated the sonographic and CT findings in surgically proven cases of gallbladder perforation.

Results

In 18 of 23 cases, both sonography and CT had been performed; in the other 5 cases, only sonography had been performed. Sonography helped to diagnose the defect in the gallbladder wall and gallbladder perforation in 16 (70%) of 23 patients. In the 18 cases in which both sonography and CT had been performed, sonography showed the wall defect in 11 cases (61%), whereas CT was diagnostic in 14 cases (78%). The difference between sonography and CT in the ability to visualize a defect in the gallbladder wall was not statistically significant.

Conclusions

Sonography is useful for diagnosing gallbladder perforation and detecting the defect in the gallbladder wall. We believe that sonography should be the first‐line imaging modality for evaluating the patients in these cases. © 2002 Wiley Periodicals, Inc. J Clin Ultrasound 30:270–274, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI: 10.1002/jcu.10071
Development of a web‐based SEM specifically for K–12 education
Authors: Chumbley L.S. , Cassucio G. , Kritikos D. , Lentz H. , Mannes C. , Mehta K.
Published: August 2002

The scanning electron microscope (SEM) is uniquely suited for use in education due to its ability to produce clear three‐dimensional‐looking images of virtually any sample. Elementary and secondary science textbooks regularly contain SEM images of bugs, plants, human tissue, rocks, etc. as a means of illustrating the microscopic world to students. However, despite the widespread use of SEM images for educational purposes microscope companies have virtually ignored the area of education in their development and design of SEMs, due presumably to a perceived lack of marketing potential in this area. This article presents the results of a program aimed at developing a Web‐based SEM that is specifically designed for educational use by students and teachers in precollege classrooms. While virtually all companies tout some form of remote control, no concerted effort has been made to fully develop these capabilities for use by the education sector. The microscope under development, termed the WebSEM, seeks to remedy this situation and address this neglected market. Remote control of the WebSEM is possible by means of a simple web interface that allows the users a wide range of controls, depending on the skill of the operator at the remote site. The web interface is specifically designed to be simple and reliable such that little or no training is required for use. This joint effort between educators and a microscope manufacturer is the first attempt at the development of a truly education‐oriented SEM suitable for use in the classroom. Microsc. Res. Tech. 56:454–461, 2002. © 2002 Wiley‐Liss, Inc.
Isolation of Dlx and Emx gene cognates in an agnathan species, Lampetra japonica, and their expression patterns during embryonic and larval development: Conserved and diversified regulatory patterns of homeobox genes in vertebrate head evolution
Authors: Myojin Miyoko , Ueki Tatsuya , Sugahara Fumiaki , Murakami Yasunori , Shigetani Yasuyo , Aizawa Shinichi , Hirano Shigeki , Kuratani Shigeru
Published: August 2002

Agnathan cognates of vertebrate homeobox genes, Emx and Dlx, were isolated from embryonic cDNA of a Japanese marine lamprey, Lampetra japonica. Analyses of amino acid sequences indicated that the Dlx cognate was closely related to the common ancestor of gnathostome Dlx1 and Dlx6 groups and termed LjDlx1/6. Southern blot analyses could not rule out the possibility that L. japonica possesses more than one paralog for both LjDlx1/6 and LjEmx, the lamprey cognate of Emx. Expression of LjDlx1/6 was regulated spatially as well as developmentally, and its transcripts were mainly found in the craniofacial and pharyngeal mesenchyme and in the forebrain. The expression pattern of LjEmx changed dramatically during embryogenesis; expression was seen initially in the entire neural tube and mesoderm, which were secondarily downregulated, and secondarily in cranial nerve ganglia and in the craniofacial mesenchyme. No specific expression of LjEmx was seen in the telencephalon. Comparisons of Dlx and Otx gene expression patterns suggested a shared neuromeric pattern of the vertebrate brain. Absence of Emx expression implied that the patterning of the lamprey telencephalon is not based on the tripartite plan that has been presumed in gnathostomes. Expression domains of LjDlx1/6 in the upper lip and of LjEmx in the craniofacial mesenchyme were peculiar features that have not been known in gnathostomes. Such differences in expression pattern may underlie distinct morphogenetic pathway of the mandibular arch between the agnathans and gnathostomes. J. Exp. Zool. (Mol. Dev. Evol.) 291:68–84, 2001. © 2001 Wiley‐Liss, Inc.
Will the new aid agenda help promote poverty reduction?
Authors: White Howard
Published: August 2002

Aid is widely perceived to have failed at poverty reduction. The last decade has seen a renewed focus on poverty and a number of changes in aid management. Will these improve aid's effectiveness at reducing poverty? The adoption of the International Development Targets is an important rallying point in emphazising poverty concerns, but do not tell us how to achieve them. Sector programmes and Poverty Reduction Strategies can both be important in enhancing the efficiency of expenditures, though there have been problems in implementation, mainly of donors being reluctant to allow government to lead the process. Less desirable are the move to selectivity on the basis of ‘good policies’ and attempts to earmark debt relief to poverty reduction expenditures. But the real issue to be tackled is to ensure that a greater proportion of aid resources are used in ways which will directly benefit the poor. Copyright © 2001 John Wiley & Sons, Ltd.
Synthesis of [C2H3]methotrexate and [C2H3]7‐hydroxymethotrexate
Authors: Elmore Charles S. , Dean Dennis C. , Zhang Yong , Gibson Carter , Jenkins Herb , Jones Allen N. , Melillo David G.
Published: August 2002

Stable label analogues of methotrexate (MTX) and 7‐hydroxymethotrexate (7‐OH‐MTX) were required for use as internal standards for LC/MS quantitation. A minimum incorporation of stable isotopes to produce a mass increase of 3 in the non‐glutamate derived portion of the molecule was necessary for adequate MS detection. The commercial availability of des‐methyl MTX (aminopterin, 1) made methylation with C2H3I an attractive option. Surprisingly, all attempted methylations of 1 and the dimethyl ester of 1 failed to provide a significant amount of the methylated aniline, apparently due to attenuated reactivity of the secondary amine towards alkylation. However, reductive amination of diacid 1 with C2H2O and NaB2H3CN gave [C2H3]MTX in 52% yield. A previously reported method was utilized to convert [C2H3]MTX to [C2H3]7‐OH‐MTX. Preparative HPLC purification of [C2H3]7‐OH‐MTX resulted in extremely low recovery from the column; this was resolved by switching to a column with few free silanols. Copyright © 2002 John Wiley & Sons, Ltd.
Morphology and ultrastructure of the malpighian tubules of the Chilean common tarantula (Araneae: Theraphosidae)
Authors: Hazelton S. Renee , Townsend Victor R. , Richter Courtney , Ritter Marnie E. , Felgenhauer Bruce E. , Spring Jeffrey H.
Published: August 2002

Relatively little is known about the morphology and ultrastructure of the Malpighian tubules of spiders (Arachnida: Araneae). Our study represents the first investigation of the Malpighian tubules of a theraphosid spider and is the only study to examine the living Malpighian tubules using confocal laser scanning microscopy. In theraphosid spiders, the Malpighian tubules originate from the stercoral pocket in the posterior portion of the opisthosoma and extend forward toward the prosoma in a dendritic pattern. There are three distinct segments (initial, main, and terminal), all dark brown in appearance. Each segment has distinctive ultrastructural features. Both the terminal and the main segment appear to be composed of at least two cell types with finger‐like cytoplasmic protrusions associated with one of these types. The terminal segment, which is most proximal to the stercoral pocket, is the largest in diameter. It is composed of large, cuboidal cells containing many mitochondria and lipid inclusions. The main segment is intermediate in diameter with many mitochondria and secretory vesicles present. The initial segment is relatively thin in comparison to the other segments and is intimately associated with the digestive gland. The cells of the initial segment contain very little cytoplasm, fewer mitochondria, secretory vesicles, and prominent inclusions. J. Morphol. 251:73–82, 2002. © 2002 Wiley‐Liss, Inc.
Survey of the year 2000 commercial optical biosensor literature
Authors: Rich Rebecca L. , Myszka David G.
Published: August 2002

We have compiled a comprehensive list of the articles published in the year 2000 that describe work employing commercial optical biosensors. Selected reviews of interest for the general biosensor user are highlighted. Emerging applications in areas of drug discovery, clinical support, food and environment monitoring, and cell membrane biology are emphasized. In addition, the experimental design and data processing steps necessary to achieve high‐quality biosensor data are described and examples of well‐performed kinetic analysis are provided. Copyright © 2001 John Wiley & Sons, Ltd.
Assessing the accuracy of two‐dimensional phase‐contrast MRI measurements of complex unsteady flows
Authors: Papaharilaou Yannis , Doorly Denis J. , Sherwin Spencer J.
Published: August 2002

Two‐dimensional phase‐contrast MRI measurements of complex unsteady flows have been assessed for accuracy, together with procedures used to improve the precision of the measurements. Velocity measurements of single harmonic sinusoidal flow in a rigid bypass graft model with a fully three‐dimensional geometry were compared to an accurate numerical solution of the Navier‐Stokes equations for the same flow. Axial velocity profiles from the MRI were compared with the computational data, and instantaneous root mean square (rms) differences were calculated. Despite the complexity of the flow, with the aid of phase angle dynamic range extension, a spatially and temporally averaged rms error of between 7.8% and 11.5%, with respect to the spatially and temporally averaged velocity, was achieved. Spin saturation primarily and phase dispersion secondarily in complex transient recirculation zones were found to be significant contributors to overall error. Cross flow effects were also investigated but were of lesser significance. The result confirms the suitability of the technique for measuring complex unsteady flows. J. Magn. Reson. Imaging 2001;14:714–723. © 2001 Wiley‐Liss, Inc.
Magnetic resonance planimetry of the vena contracta as a new approach to assessment of stenotic heart valves: An in vitro study
Authors: Strohm Oliver , Schulz‐Menger Jeanette , Hänlein Dankward , Dietz Rainer , Friedrich Matthias G.
Published: August 2002

Exact determination of the orifice area in stenotic valve disease is essential to guide therapy. With the standard imaging methods, the orifice area has to be calculated by empirically‐derived formulas, which may be susceptible to changes in hemodynamic status, leading to wrong therapeutic decisions. We tested the ability of magnetic resonance imaging (MRI) to quantify the orifice area by planimetry of the proximal vena contracta (PVC) in an idealized, constant‐flow model in a 1.0‐T tomograph (Siemens Magnetom Expert). There was a close correlation of the PVC area in MRI and the true orifice area (r2 = 0.985), and agreement of the methods as measured by the Bland‐Altman test was significant with a low systematic error of –0.02 cm2. We conclude that MRI planimetry of the PVC in stenotic valves in a constant‐flow model may be used to reliably measure the orifice area. J. Magn. Reson. Imaging 2001;14:31–34. © 2001 Wiley‐Liss, Inc.
Metallic neurosurgical implants: Evaluation of magnetic field interactions, heating, and artifacts at 1.5‐Tesla
Authors: Shellock Frank G.
Published: August 2002

The purpose of this study was to use ex vivo testing to determine the magnetic resonance imaging (MRI) safety aspects for seven different metallic neurosurgical implants in association with the 1.5‐T MR environment. Ex vivo testing was performed using previously‐described techniques for the evaluation of magnetic field interactions (deflection angle and torque), heating (gel‐filled phantom and fluoroptic thermometry; 15 minutes of MRI at a specific absorption rate [SAR] of 1.4 W/kg), and artifacts (using T1‐weighted, spin‐echo and gradient‐echo pulse sequences). None of the metallic implants displayed interactions with the magnetic field. The highest temperature change was +0.6°C for the representative implant that was evaluated. Artifacts were relatively minor. The lack of magnetic field interactions and negligible heating indicate that MR procedures may be conducted safely in patients with these neurosurgical implants using MR systems with static magnetic fields of 1.5‐T or less. Furthermore, these implants may be considered for use in interventional MR procedures insofar as the MR safe qualities and relatively small artifacts would likely be desirable for such procedures. J. Magn. Reson. Imaging 2001;14:295–299. © 2001 Wiley‐Liss, Inc.
Magnetic resonance flow measurements in real time: Comparison with a standard gradient‐echo technique
Authors: Klein Christoph , Schalla Simon , Schnackenburg Bernhard , Bornstedt Axel , Fleck Eckart , Nagel Eike
Published: August 2002

Ultrafast gradient systems and hybrid imaging sequences offer the opportunity to acquire phase contrast flow data in real time. In a 1.5‐Tesla magnetic resonance (MR)‐tomograph, peak velocity and volume flow were assessed in 36 large vessels (aorta) and 33 medium‐sized vessels (carotid and iliac artery) using a real‐time (segmented k‐space turbo gradient‐echo planar imaging sequence) in comparison with a gradient‐echo technique. With the real‐time technique, the matrix was reduced from 116 to 64, and temporal resolution changed from 30 msec to 124 msec. Measurements of peak velocity correlated in large (r = 0.88) and medium‐sized vessels (r = 0.81). Volume flow measurements correlated in large vessels (r = 0.87), however, a poor correlation (r = 0.64) was found in medium‐sized vessels. Thus, scan time can be significantly reduced and images acquired without electrocardiogram (ECG)‐triggering. Flow volume can only be determined in large vessels with sufficient accuracy, mainly due to reduced spatial resolution in smaller vessels.J. Magn. Reson. Imaging 2001;14:306–310. © 2001 Wiley‐Liss, Inc.
Mass spectrometric studies of the path of carbon in photosynthesis: positional isotopic analysis of 13C‐labelled C4 to C7 sugar phosphates
Authors: MacLeod John K. , Flanigan Ian L. , Williams John F. , Collins J. Grant
Published: August 2002

The (EIMS) electron ionization mass spectrometric fragmentation patterns of the methoxime‐ and ethoxime‐trimethylsilyl (TMS) derivatives of C4 to C7 sugars involved as phosphates in the Calvin pathway of photosynthesis in plants were analysed by gas chromatography/EIMS using specifically labelled 13C analogs. In general, most but not all of the major ions in the mass spectra arise from single carbon–carbon bond cleavages of the straight‐chain derivatives. The results confirm that GC/MS of the alkoxime‐TMS derivatives is a viable method for measuring 13C incorporations at individual carbon atoms in each of the sugar phosphates during photosynthetic experiments with 13CO2. Copyright © 2001 John Wiley & Sons, Ltd.
Analysis of sulfated peptides using positive electrospray ionization tandem mass spectrometry
Authors: Nemeth‐Cawley Jennifer F. , Karnik Smita , Rouse Jason C.
Published: August 2002

Presented is a method for analyzing sulfated peptides, and differentiating the post‐translational modification (PTM) from its isobaric counterpart phosphorylation, using quadrupole time‐of‐flight (Qq/TOF) mass spectrometry (MS) and positive ion nanoelectrospray MS/MS. A set of commercially available sulfo‐ and phosphopeptide standards was analyzed via in‐source dissociation and MS/MS to generate fragmentation signatures that were used to characterize and differentiate the two modifications. All of the phosphorylated peptides retained their +80 Da modifications under collision‐induced decomposition (CID) conditions and peptide backbone fragmentation allowed for the site‐specific identification of the modification. In sharp contrast, sulfated peptides lost SO3 from the precursor as the collision energy (CE) was increased until only the non‐sulfated form of the peptide was observed. The number of 80 Da losses indicated the number of sulfated sites. By continuing to ramp the CE further, it was possible to fragment the non‐sulfated peptides and obtain detailed sequence information. It was not possible to obtain site‐specific information on the location of the sulfate moieties using positive ion MS/MS as none of the original precursor ions were present at the time of peptide backbone fragmentation. This method was applied to the analysis of recombinant human B‐domain deleted factor VIII (BDDrFVIII), which has six well‐documented sulfation sites and several potential phosphorylation sites located in two of the sulfated regions of the protein. Seven peptides with single and multiple +80 Da modifications were isolated and analyzed for their respective PTMs. The fragmentation patterns obtained from the BDDrFVIII peptides were compared with those obtained for the standard peptides; and in all cases the peptides were sulfated. None of the potential phosphorylation sites were found to be occupied, and these results are consistent with the literature. Copyright © 2001 John Wiley & Sons, Ltd.
Infrared laser desorption and ionization of polypeptides from a polyacrylamide gel
Authors: Baltz‐Knorr Michelle , Ermer David R. , Schriver Kenneth E. , Haglund Richard F.
Published: August 2002

We observed direct desorption and ionization of angiotensin II and bovine insulin from a frozen polyacrylamide gel without the addition of an exogenous matrix, using picosecond pulses from a tunable, mid‐infrared free‐electron laser tuned to strong absorption bands of the gel. At 5.7, 5.9, 6.1 and 6.3 µm we were able to desorb and ionize both analyte molecules, with the strongest analyte signal generated at 5.9 µm. However, no analyte signal was observed at 5.5 µm. Consistent with a previous report, we did not observe ions of either polypeptide at 2.9 µm, in spite of strong overall absorption. We discuss the implications of this wavelength‐dependent ionization, including possible ablation mechanisms and energy partitioning between competing vibrational modes. Copyright © 2002 John Wiley & Sons, Ltd.
Molecular epidemiology of ‘Norwalk‐like viruses’ associated with gastroenteritis outbreaks in New Zealand
Authors: Greening Gail E. , Mirams Michiko , Berke Tamas
Published: August 2002

Outbreaks of gastroenteritis are a major public health problem in New Zealand. The introduction of molecular detection methods has now shown that the ‘Norwalk‐like viruses’ (NLVs) are the major cause of food and waterborne nonbacterial gastroenteritis. Reverse transcription and polymerase chain reaction (RT‐PCR) were used to determine the presence of NLVs in faecal specimens from 83 nonbacterial gastroenteritis outbreaks occurring in New Zealand between August 1995 and July 1999. Further characterisation of the NLVs for epidemiological purposes was carried out by dot blot DNA hybridisation and DNA sequencing of representative outbreak strains. The majority of NLV strains occurring in New Zealand since August 1995 are similar to those occurring overseas. The predominant New Zealand strain is genetically similar to the Bristol/Lordsdale virus group. Several New Zealand outbreaks were attributed to Auckland virus, a Mexico‐like NLV strain identified as the most likely cause of gastroenteritis after consumption of contaminated oysters in 1994. A new strain, designated Napier virus, has been identified in six outbreaks since 1996. A number of strains closely resembling internationally recognised strains, including Southampton virus, Saratoga virus; Desert Shield virus and Melksham virus have been associated with gastroenteritis outbreaks across New Zealand. Application of these typing methods has provided information on disease transmission for epidemiological investigations of public health significance. J. Med. Virol. 64:58–66, 2001. © 2001 Wiley‐Liss, Inc.
Genetic variability of respiratory syncytial virus subgroup a strain in 15 successive epidemics in one city
Authors: Seki Kimihira , Tsutsumi Hiroyuki , Ohsaki Masaya , Kamasaki Hodaka , Chiba Shunzo
Published: August 2002

The genetic variability of 125 respiratory syncytial virus (RSV) subgroup A isolates over 15 successive epidemics from 1980 to 1995 in an urban population of Japan was determined. Allocation of isolates into lineages was archived by reverse transcriptase‐polymerase chain reaction amplification of selected regions of the nucleoprotein (NP) and attachment (G) protein gene followed by restriction fragment length polymorphism (RFLP) analysis. Three and seven distinct restriction patterns of the NP and G gene were observed, respectively. When the NP and G gene RFLP analyses were combined, ten different genetic lineages were identified in the 125 isolates. The strains with the same genotype were isolated in each epidemic and the dominant lineages were replaced by others after every one to three consecutive epidemics. Nucleotide and amino acid sequencing of the variable region of G gene of these predominant isolates revealed differences of 5–28% between strains. There was, however, no apparent accumulation of diversity with age to indicate progressive changes. The dominant strains were often closely related to those isolated in other parts of the world at a similar time. These observations suggest that dominant RSV strains are replaced frequently by others that have been co‐circulating or have recently entered the community from a worldwide reservoir. The change of dominant strains may be influenced by the buildup of immunological resistance in the community to successive epidemics of the same strain. J. Med. Virol. 64:374–380, 2001. © 2001 Wiley‐Liss, Inc.
A case of human Orf in an immunocompromised patient treated successfully with cidofovir cream
Authors: Geerinck K. , Lukito G. , Snoeck R. , De Vos R. , De Clercq E. , Vanrenterghem Y. , Degreef H. , Maes B.
Published: August 2002

Immunocompromised patients may have severe forms of infections. Since there is an increasing number of patients maintained under immunosuppressive therapy, we will be confronted with increasing frequency with these infectious problems. Effective treatments will be of great value. The case is described of a renal transplant with a giant orf lesion, which continued growing instead of regressing spontaneously as is observed usually. The treatment options in such patients are limited. It was decided to treat the patient with the antiviral drug cidofovir (HPMPC, Vistide®). Topical cidofovir treatment resulted in complete regression of the lesion. This case is discussed in the context of the known literature on orf (ecthyma contagiosum). J. Med. Virol. 64:543–549, 2001. © 2001 Wiley‐Liss, Inc.
Sequence analysis of genes encoding structural and nonstructural proteins of a human group B rotavirus detected in Calcutta, India
Authors: Kobayashi Nobumichi , Naik Trailokya N. , Kusuhara Yasuhiro , Krishnan Triveni , Sen Adrish , Bhattacharya Sujit K. , Taniguchi Koki , Alam Md. Mahbub , Urasawa Tomoko , Urasawa Shozo
Published: August 2002

Nucleotide sequences of RNA segments encoding structural proteins(VP4, VP6, and VP7) and nonstructural proteins(NSP1 and NSP3) of a human group B rotavirus CAL‐1, which was detected in Calcutta, India, were determined and their relatedness with cognate genes of other group B rotaviruses was analyzed. The CAL‐1 genes showed generally high sequence identities (more than 90%) to those of human group B rotavirus, adult diarrheal rotavirus (ADRV) in China, while identities with bovine, murine, and ovine viruses were considerably lower (58–73%). Among RNA segments analyzed, sequence identity of the VP6 gene was relatively high compared with other gene segments. In the CAL‐1 VP7 sequence, many characteristics were shared by ADRV, but not by other animal group B rotaviruses. In contrast, VP4 and NSP3 of CAL‐1 were single animo acid and 23 amino acids longer than those of ADRV strain, respectively, due to differences of a few nucleotides. These findings suggested that human group B rotaviruses CAL‐1 and ADRV might have originated from a common ancestral virus distinct from animal group B rotaviruses reported so far, while some notable sequence differences indicated the distinct nature of these viruses. J. Med. Virol. 64:583–588, 2001. © 2001 Wiley‐Liss, Inc.
Intrahepatic HCV RNA loads in 37 HIV‐HCV co‐infected patients with controlled HIV infection
Authors: Trimoulet P. , Neau D. , Le Bail B. , Rullier A. , Winnock M. , Galperine T. , Legrand E. , Schvoerer E. , Dupon M. , Ragnaud J.M. , Bioulac‐Sage P. , Chêne G. , Fleury H. , Lafon M.E.
Published: August 2002

Serum and intrahepatic hepatitis C virus (HCV) RNA were measured in 37 HIV‐HCV co‐infected patients with controlled human immunodeficiency virus (HIV) infection and correlated with clinical, biological, and histological parameters. Thirty‐seven interferon‐naive patients underwent liver biopsy. HCV‐induced activity (A) and fibrosis (F) were evaluated with METAVIR score. The 37 patients included had HIV plasma loads < 10,000 copies/ml, CD4+ count > 250/μl. All the patients but two were receiving antiretroviral treatment. Liver tissue and sera were used for measurement of HCV RNA by the Cobas Amplicor HCV Monitor. All patients had serum and liver HCV RNA, and both levels were correlated (r = 0.47; P = 0.003). Intrahepatic HCV load did not depend on age, sex, duration of HCV infection, CD4+, HCV genotype, or fibrosis. AST levels correlated with intrahepatic HCV load (r = 0.52; P = 0.001). Patients with METAVIR A1/A2 had significantly lower levels of liver HCV‐RNA than were found in patients with METAVIR A3 (P = 0.026). Highly active antiretroviral therapy (HAART) including protease inhibitors(PI)‐treated patients had significantly lower intrahepatic HCV load (P = 0.04). A weak but significant correlation between serum and liver HCV RNA was found. The amount of hepatic HCV RNA was correlated with AST levels, histological activity, but not with HCV genotype or fibrosis. The immune improvement associated with PI regimens could help reduce HCV load, supporting a protective effect of PI‐induced immune restoration.
J. Med. Virol. 67:143–151, 2002. © 2002 Wiley‐Liss, Inc.
Peroxynitrite triggers a phenotypic transformation in spinal cord astrocytes that induces motor neuron apoptosis
Authors: Cassina Patricia , Peluffo Hugo , Pehar Mariana , Martinez‐Palma Laura , Ressia Andrés , Beckman Joseph S. , Estévez Alvaro G. , Barbeito Luis
Published: August 2002

Oxidative stress mediated by nitric oxide (NO) and its toxic metabolite peroxynitrite has previously been associated with motor neuron degeneration in amyotrophic lateral sclerosis (ALS). Degenerating spinal motor neurons in familial and sporadic ALS are typically surrounded by reactive astrocytes expressing the inducible form of NO synthase (iNOS), suggesting that astroglia may have a pathogenic role in ALS. We report here that a brief exposure of spinal cord astrocyte monolayers to peroxynitrite (0.25–1 mM) provoked long‐lasting reactive morphological changes characterized by process‐bearing cells displaying intense glial fibrillary acidic protein and iNOS immunoreactivity. Furthermore, peroxynitrite caused astrocytes to promote apoptosis of embryonic motor neurons subsequently plated on the monolayers. Neuronal death occurred within 24 hr after plating, as evidenced by the presence of degenerating motor neurons positively stained for activated caspase‐3 and nitrotyrosine. Motor neuron death was largely prevented by NOS inhibitors and peroxynitrite scavengers but not by trophic factors that otherwise will support motor neuron survival in the absence of astrocytes. The bacterial lipopolysaccharide, a well‐known inflammatory stimulus that induces iNOS expression in astrocytes, provoked the same effects on astrocytes as peroxynitrite. Thus, spinal cord astrocytes respond to extracellular peroxynitrite by adopting a phenotype that is cytotoxic to motor neurons through peroxynitrite‐dependent mechanisms. © 2002 Wiley‐Liss, Inc.
Establishment and characterization of spontaneously immortalized Schwann cells from murine model of globoid cell leukodystrophy (twitcher)
Authors: Shen Jin‐Song , Watabe Kazuhiko , Meng Xing‐Li , Ida Hiroyuki , Ohashi Toya , Eto Yoshikatsu
Published: August 2002

The twitcher mouse is a murine model of human globoid cell leukodystrophy (GLD; Krabbe disease) caused by a genetic defect in the activity of galactosylceramidase (GALC). An accumulation of cytotoxic metabolite, galactosylsphingosine (psychosine), in myelin forming cells (oligodendrocytes and Schwann cells) of the twitcher mouse as well as patients with GLD has been suggested to cause dysfunction of these cells and subsequent demyelination in the central and peripheral nervous system. To investigate further the cellular pathomechanism of GLD, we established spontaneously immortalized Schwann cell lines from the twitcher mouse. Long‐term cultures of Schwann cells derived from dorsal root ganglia and consecutive peripheral nerves of 3‐week‐old twitcher mice were maintained for 6 months, and spontaneously developed colonies were expanded further and characterized. One of the cell lines, designated TwS1, showed distinct Schwann cell phenotypes, was passaged twice a week and maintained for over 10 months without phenotypic alterations. The TwS1 cells had a nonsense mutation in the GALC genome, and showed markedly reduced GALC activity and elevated psychosine levels. Ultrastructurally, varieties of cytoplasmic inclusions were demonstrated in TwS1 cells. When TwS1 cells were infected with a retrovirus vector encoding GALC, GALC activity was markedly increased and psychosine levels were significantly decreased. These immortalized Schwann cells can be useful in studies on the nervous system lesions in GLD. © 2002 Wiley‐Liss, Inc.