bluuebunny/crossref_metadata_2025 huggingface dataset:
Structural characterization of chondroitin/dermatan sulfate oligosaccharides from bovine aorta by capillary electrophoresis and electrospray ionization quadrupole time‐of‐flight tandem mass spectrometry
Authors: Zamfir Alina , Seidler Daniela G. , Kresse Hans , Peter‐Katalinić Jasna
Published: October 2002

An Erratum for this article has been published in Rapid Communications in Mass Spectrometry 17(3) 2003, 265

An analytical approach based on high‐performance capillary electrophoresis (CE) in conjunction with electrospray ionization quadrupole time‐of‐flight tandem mass spectrometry (ESI‐QTOF‐MS/MS) has been developed for providing the basis to obtain new insights into the domain structure of the glycosaminoglycan (GAG) moiety of proteoglycans. The feasibility and performance of the off‐line CE/ESI‐QTOF‐MS approach in GAG oligosaccharide analysis were assessed by screening a chondroitin/dermatan sulfate (DS) oligosaccharide mixture obtained from bovine aorta by enzymatic depolymerization by chondroitin B lyase. The CS/DS mixture was analyzed by CE using 50 mM ammonium acetate, pH 12.0, dissolved in aqueous methanol (2:3; v/v), as a CE carrier. Structural identification of the GAG components was achieved using off‐line CE/nanoESI‐QTOF‐MS and‐MS/MS experiments. ESI‐QTOF instrumental parameters were found to play an important role in the MS screening of the CE‐separated GAG species. By optimizing the ESI conditions, oligosaccharides differing in chain length and degree of sulfation could be detected. The building block composition, the size of the carbohydrate chain, as well as structural features of the repeating HexA‐GalNAc, HexA‐GalNAc(S) units, have been determined using MS/MS by applying collision‐induced dissociation at low energies. Cleavage of GAG chains by chondroitin B lyase occurs with formation of structural markers useful for identification of IdoA‐containing domains. Copyright © 2002 John Wiley & Sons, Ltd.
Effect of water treatment on analyte and matrix ion yields in matrix‐assisted time‐of‐flight secondary ion mass spectrometry: the case of insulin in and on hydroxycinnamic acid
Authors: Szymczak Wilfried , Wittmaack Klaus
Published: October 2002

A systematic study was performed to identify the origin of surprisingly high analyte‐to‐matrix yield ratios recently observed in time‐of‐flight secondary ion mass spectrometry (TOF‐SIMS) analysis of oligo‐ and polypeptides mixed in matrices of α‐cyano‐4‐hydroxycinnamic acid (4HCCA). Several sets of samples of porcine insulin in 4HCCA (1:3100 molar) were prepared from liquid solutions by a nebuliser technique, with more than one order of magnitude variation in sprayed material (substrate silicon). Following different periods of storage in air and/or vacuum as well as exposure to high‐purity water, TOF‐SIMS analysis was performed under oblique impact of 22 keV SF5+. Treatment with water involved either deposition of a droplet covering the whole sample for times between 1 and 20 min or spraying with water in droplet equivalent quantities. The analyte and matrix molecules were detected as protonated molecules (insulin also in doubly protonated form). Even the as‐prepared samples usually showed insulin‐to‐4HCCA yield ratios exceeding the molar ratio of the mixed material. Upon ageing in vacuum the matrix ion yields remained constant but the analyte yields decreased, partly due to break‐up of intrachain disulfide bonds. Water treatment resulted in a pronounced decrease in the 4HCCA yield, typically by a factor of five, in parallel with an increase of the insulin yield, by up to a factor of four. Evidence is provided that these changes occur concurrently with a partial dissolution of 4HCCA at the sample surface. The enhanced insulin yield was not correlated with the Na+ yield. The typically 20‐fold increase in the insulin‐to‐4HCCA yield ratio, generated by water exposure of the samples, provides the explanation for the high yield ratios observed previously with water‐treated samples. Spraying with water or repeated exposure to water droplets caused a pronounced degradation of the insulin parent yields in combination with an increasing appearance of signals due to the B‐ and A‐chains of insulin. To clarify the issue of surface segregation, a few samples were prepared by spraying acetone‐diluted solutions of insulin on previously deposited layers of 4HCCA. Whereas the insulin yields from as‐prepared samples were rather low, the yields observed after water treatment were comparable with those observed with samples of insulin in 4HCCA. The results suggest that a large amount of insulin is present at the surface of samples prepared from liquid mixtures of insulin in 4HCCA. With both methods of sample preparation, however, high secondary ion yields of insulin were only obtained after exposure of the samples to water. The chemical changes responsible for this beneficial effect still need to be identified. Copyright © 2002 John Wiley & Sons, Ltd.
Determination of wheat quality by mass spectrometry and multivariate data analysis
Authors: Gottlieb David Mark , Schultz Jakob , Petersen Marianne , Nesic Ljiljana , Jacobsen Susanne , Søndergaard Ib
Published: October 2002

Multivariate analysis has been applied as support to proteome analysis in order to implement an easier and faster way of data handling based on separation by matrix‐assisted laser desorption/ionisation time‐of‐flight mass spectrometry. The characterisation phase in proteome analysis by means of simple visual inspection is a demanding process and also insecure because subjectivity is the controlling element. Multivariate analysis offers, to a considerable extent, objectivity and must therefore be regarded as a neutral way to evaluate results obtained by proteome analysis.

Proteome analysis of storage proteins from the wheat gluten complex based on two‐dimensional electrophoresis and analysis of the N‐terminal sequence has revealed a protein homologous to γ‐gliadins, tentatively associated with quality and within the molecular weight range 27–35 kDa. Further examinations of gliadin data based on mass spectrometry revealed that quality among wheat varieties could be determined by means of principal component analysis. Further examinations by interval partial least squares made it possible to encircle an overall optimal molecular weight interval from 31.5 to 33.7 kDa. The use of multivariate analysis on data from mass spectrometry has thus shown to be a promising technique to minimize the number of two‐dimensional gels within the field of proteome analysis. Copyright © 2002 John Wiley & Sons, Ltd.
Mass spectra of 1,3,5‐triarylpentane‐1, 5‐diones: formation and decomposition of pyrilium cation from the molecular ion
Authors: MPOH Godefroy Elanga , Tapsoba Edouard , Nébié Roger Charles , Bonzi‐Coulibaly Yvonne Libona , Sié Faustin Sib
Published: October 2002

Electron impact mass spectra of 1,3,5‐triarylpentane‐1,5‐diones are reported. All compounds studied show a tendency to eliminate a water molecule and also the elements of [H3O] before fragmentation to smaller ions. The [H3O] loss proceeds via loss of water to form a pyran ion, which subsequently eliminates a hydrogen atom to form the stable pyrillium cation. Copyright © 2002 John Wiley & Sons, Ltd.
Investigation of an enhanced resolution triple quadrupole mass spectrometer for high‐throughput liquid chromatography/tandem mass spectrometry assays
Authors: Yang Liyu , Amad Ma'an , Winnik Witold M. , Schoen Alan E. , Schweingruber Hans , Mylchreest Iain , Rudewicz Patrick J.
Published: October 2002

Triple quadrupole mass spectrometers, when operated in multiple reaction monitoring (MRM) mode, offer a unique combination of sensitivity, specificity, and dynamic range. Consequently, the triple quadrupole is the workhorse for high‐throughput quantitation within the pharmaceutical industry. However, in the past, the unit mass resolution of quadrupole instruments has been a limitation when interference from matrix or metabolites cannot be eliminated. With recent advances in instrument design, triple quadrupole instruments now afford mass resolution of less than 0.1 Dalton (Da) full width at half maximum (FWHM). This paper describes the evaluation of an enhanced resolution triple quadrupole mass spectrometer for high‐throughput bioanalysis with emphasis on comparison of selectivity, sensitivity, dynamic range, precision, accuracy, and stability under both unit mass (1 Da FWHM) and enhanced (≤0.1 Da FWHM) resolution. The advantage of enhanced resolution was demonstrated in the case of mometasone with polypropylene glycol (PPG) interference. At unit mass resolution, the transmitted precursor ion from the first quadrupole contained not only protonated molecules from mometasone, but also PPG interference. At enhanced resolution only selected mometasone peaks were transmitted, and no interference from PPG was detected. Sensitivity of the instrument was demonstrated with 10 femtograms of descarboethoxyloratadine injected on‐column, for which a signal‐to‐noise (S/N) ratio of 24 was obtained for MRM chromatograms at both unit and enhanced resolution. Absolute signals obtained at enhanced resolution were about one‐third those obtained at unit mass resolution. However, S/N was maintained at enhanced resolution due to the proportional decrease in noise level. Finally, the stability of the instrument operating at enhanced resolution was demonstrated during an overnight 17 h period that was used to validate a liquid chromatography/tandem mass spectrometry (LC/MS/MS) assay for the quantitation of loratadine and descarboethoxyloratadine in human plasma. Assay performances (dynamic range, correlation coefficients for standard curves, precision and accuracy for QC samples) under unit and enhanced resolution were both within current pharmaceutical and regulatory guidelines demonstrating the stability of the mass spectrometer operating at enhanced resolution for typical bioanalytical high‐throughput applications. Copyright © 2002 John Wiley & Sons, Ltd.
Mass spectrometric study of some 4‐pyrimidine carboxylic acids
Authors: Jovanović Bratislav Ž. , Perić‐Grujić Aleksandra A. , Marinković Aleksandar D. , Vajs Vlatka V.
Published: October 2002

Mass spectrometry has been applied in order to study the main fragmentation routes of some 4‐pyrimidene carboxylic acids. Differences in fragmentation were caused by the nature of the substituent in position 2 of the pyrimidine ring, while the methyl group in position 1, 3 or 6 did not influence the fragmentation route. Copyright © 2002 John Wiley & Sons, Ltd.
A robust micro‐electrospray ionization technique for high‐throughput liquid chromatography/mass spectrometry proteomics using a sanded metal needle as an emitter
Authors: Guzzetta Andrew W. , Thakur Rohan A. , Mylchreest Iain C.
Published: October 2002

A 60 µm internal diameter (i.d.) stainless‐steel needle was adapted to the orthogonal ESI probe (µESI) of a commercial ion trap mass spectrometer, and used for capillary liquid chromatography/tandem mass spectrometry (LC/MS/MS) protein identification experiments. The modification allows for the use of nitrogen sheath gas which helps in the nebulization at LC flow rates exceeding 500 nL/min and eliminates problems caused by liquid junctions commonly used to initiate nanospray ionization (NSI). A comparison is made between the performance of a 75 µm i.d. column with a 15 µm pulled glass tip using a liquid junction, and that of a 150 µm i.d. column using the new µESI device. The combination of the 150 µm i.d. column and µESI gave sensitivity close to that of NSI (250 attomoles horse heart myoglobin digest on column), and proved to be more robust than the standard pulled glass tips of similar i.d. No evidence of metal needle catalyzed oxidation of methionine was observed during analysis of the tetrapeptide MRFA under a range of test conditions. Phosphorylated peptides in a β‐casein tryptic digest were also successfully identified using the µESI interface with a steel needle. In addition it was found that a mild sanding of the metal needle tip improved spray performance. Copyright © 2002 John Wiley & Sons, Ltd.
The identification of in vitro metabolites of CKD‐732 by liquid chromatography/tandem mass spectrometry
Authors: Myung Seung‐Woon , Kim Hye‐Young , Min Hye‐Ki , Kim Dong‐Hyun , Kim Myungsoo , Cho Hyun‐Woo , Lee Ho Sup , Kim Joon‐Kyum , Hong Chung II
Published: October 2002

The structural elucidation of fourteen metabolites of CKD‐732, formed in vitro with rat liver microsomes, was performed using high‐performance liquid chromatography/electrospray ionization‐tandem mass spectrometry (HPLC/ESI‐MS/MS). To identify proposed structures of the metabolites, the product ion mass spectra of the protonated molecules ([M + H]+), the retention times on reversed‐phase HPLC, and UV‐Vis spectra were utilized. Characteristic product ions for the identification of CKD‐732 metabolites were observed at m/z 231, 236, and 252. The fragment ions at m/z 236 and 252 indicated the unchanged form and the N‐oxide of the dimethylaminoethoxycinnamoyl group, respectively. The ion at m/z 231 indicated the presence of the hydroxylated form of the fumagillol group. The N‐oxide of CKD‐732, which was detected at m/z 515 and eluted later than CKD‐732 in the reversed‐phase HPLC system, was measured as a major metabolite. Three cis‐trans isomers were also found. Copyright © 2002 John Wiley & Sons, Ltd.
On‐line microdialysis for enhanced resolution and sensitivity during electrospray mass spectrometry of non‐covalent complexes and competitive binding studies
Authors: Benkestock Kurt , Edlund Per‐Olof , Roeraade Johan
Published: October 2002

Many proteins and macromolecules easily form metal adduct ions which impairs their analysis by mass spectrometry. The present study describes how the formation of undesired adducts can be minimized by on‐line microdialysis for non‐covalent binding studies of macromolecules with low molecular mass ligands with electrospray ionization mass spectrometry (ESI‐MS). The technique was indispensable for protein‐ligand studies due to reduction of unwanted adduct ions, and thus gave excellent resolution and a sensitivity improvement of at least 5 times. The core of the analytical system was a modified microdialysis device, which was operated in countercurrent mode. A novel technique based on microdialysis for competitive binding studies is also presented. The non‐covalent complex between a protein and a ligand was formed in the sample vial prior to analysis. The complex was injected into an on‐line microdialysis system where a competitive ligand was administered in the dialysis buffer outside of the fiber. The second ligand competitively displaced the first ligand through transport via the wall of the dialysis fiber, and the intact complexes were detected by ESI‐MS. Copyright © 2002 John Wiley & Sons, Ltd.
Advanced concurrent design environment for multimedia system LSIs
Authors: Iwasaki Hiroe , Ochiai Katsuyuki , Naganuma Jiro , Endo Makoto , Ogura Takeshi
Published: October 2002

This paper proposes a high‐speed software‐based platform for embedded software and evaluates its benefits on a commercial MPEG‐2 video encoder LSI with HDTV scalability. The platform is written in C/C++ languages without any hardware description languages (HDLs) for high‐speed simulation. This platform is applicable before writing up complete HDLs. The simulation speed is very fast and is more than 600 times faster than compiled HDL simulators using RTL description. Fifty percent of the bugs in the final embedded software were located efficiently and quickly, and the design turn‐around time was shortened by more than 25%. This platform provides sufficient performance and capability for validating practical embedded software. © 2002 Wiley Periodicals, Inc. Syst Comp Jpn, 33(14): 72–80, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/scj.10004
An operating system for an online transaction processing system with a heavy load
Authors: Hakomori Satoshi , Taniguchi Hideo
Published: October 2002

In this paper, we describe an operating system for terminal controller which controls communication lines and terminals in a large‐scaled distributed transaction processing system. Since the controller deals with a lot of transaction requests from terminals concurrently, its operating system needs to mange resources efficiently in order to guarantee the maximum response time. Besides, system availability and efficiency for system maintenance are also required, therefore the operating system has to provide essential facilities. Our operating system has been developed to satisfy such requirements in a practical way. This paper introduces the major features, evaluation results, and states of the application. © 2002 Wiley Periodicals, Inc. Syst Comp Jpn, 33(14): 59–71, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/scj.10012
NFS‐based secure file sharing over multiple administrative domains with minimal administration
Authors: Yamai Nariyoshi , Nakayoshi Kou , Ishibashi Hayato , Abe Kota , Murakami Koso , Matsuura Toshio
Published: October 2002

Although several schemes of file sharing for Unixes have been proposed so far, file sharing by these schemes between different administrative domains is difficult and imposes enormous burden on the administrators even if file sharing is possible since the user information differs by such computers in general. In this paper, the file system PNFS (Proxy/Private Network File System), which makes file sharing based on NFS easy between different administrative domains, is proposed. With PNFS, a user can share files of a server that has his account without intervention of its administrator. Although, in general, a decrease in security occurs when intervention of an administrator is omitted, security is enhanced by encryption and the like by the PNFS. In addition, the efficacy of the proposed system has been verified by performance evaluation of a prototype system, which shows a practically sufficient throughput even with simultaneous accesses from a multiple number of clients. © 2002 Wiley Periodicals, Inc. Syst Comp Jpn, 33(14): 50–58, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/scj.10027
Eye movement based on short‐term memory optical flow image
Authors: Morita Satoru , Ishihara Yukio
Published: October 2002

The pixel distribution density of human vision is higher near the fovea, becoming lower toward the periphery. It is also reported that the optical flow has an important role in understanding the surrounding situation. This paper proposes the eye movement model based on fovea vision, short‐term memory of the optical flow, and parallel execution of the tasks. In the realization of the eye movement while driving in an environment where there are few vehicles, both the narrow‐range eye movement to shift the viewpoint to the next edge along the road, and the wide‐range eye movement to understand the environmental situation, must be realized. In order to adjust the range of eye movement according to the task, short‐term memory depending on the task is considered. It is shown that a wide range of view field can be realized, by using the short‐term memory image, which is generated based on the low‐level features derived from the optical flow. The eye movement while driving in a situation where there are few vehicles is actually simulated in a simple way, and the usefulness of the proposed model is demonstrated. © 2002 Wiley Periodicals, Inc. Syst Comp Jpn, 33(13): 24–34, 2002; Published online in Wiley InterScience (www.interscience. wiley.com). DOI 10.1002/scj.10132
MGGA: Genetic algorithm with mutant genes
Authors: Takahama Tetsuyuki , Sakai Setsuko , Isomichi Yoshinori
Published: October 2002

In this research, we propose a new genetic algorithm called MGGA (Genetic Algorithm with Mutant Genes), in which mutant genes are introduced actively. An individual with mutant genes may express the phenotype of the genes imperfectly, or may even fail to express the phenotype. To realize this phenomenon, we give a new mapping function, which depends on mutant genes, from genotype to phenotype. We also introduce irreversible changes from a normal gene into a mutant gene. We can reduce the number of genes that have lower effectiveness by these irreversible changes. Through structural learning of a polynomial model and layered neural networks, we show that MGGA can optimize the parameter structure of the models and is a general‐purpose method for structural learning. © 2002 Wiley Periodicals, Inc. Syst Comp Jpn, 33(14): 23–33, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/scj.10179
Texture mapping on free‐form surfaces immune to camera positioning errors
Authors: Iwakiri Yuuya , Omori Yuuichi , Kaneko Toyohisa
Published: October 2002

The fact that three‐dimensional CG is made from an object on hand implies that textures need to be acquired from the object. We already proposed a method for identifying a minimal number of camera positions for acquiring textures. Although it enables the selection of a minimal number of camera positions, it often results in untextured patches due to camera misalignment: a deviation of actual camera position from the specified position. This paper proposes two new practical algorithms (double and product viewing) to ensure that all the polygons are textured even if there are unavoidable human errors in camera alignment. The performance of the algorithms is evaluated by simulation experiments. © 2002 Wiley Periodicals, Inc. Syst Comp Jpn, 33(13): 1–10, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/scj.10242
On‐line supervising mechanism for learning data in surface electromyogram motion classifiers
Authors: Nishikawa Daisuke , Yu Wenwei , Yokoi Hiroshi , Kakazu Yukinori
Published: October 2002

This paper proposes a mechanism that supervises the learning data set for the classification from electromyogram to forearm motion. The supervising mechanism contains automatic data addition and automatic data elimination processes. It also contains manual data addition that is the same as our former algorithm. Both the automatic addition and elimination processes evaluate success or failure of classification from the continuity of the classifier's outputs. These processes assume that a person cannot change his motion within a certain interval. In experiments, a system with the supervising mechanism embedded classifies ten forearm motions from two channels of the electromyogram. First, this paper makes it clear that the proposed mechanism is effective by comparison with six settings, including the absence of a supervising pattern. Next, it is verified that the system can adapt to alteration of the operator's characteristics by a sensor‐shifting test in which we move one sensor after the operator's training. From the experimental results, it is concluded that the proposed mechanism can adjust the generated decision boundaries for improvement of classification ability, and in addition is capable of tracking the alteration of the operator's characteristics through time. © 2002 Wiley Periodicals, Inc. Syst Comp Jpn, 33(14): 1–11, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/scj.10245
Construction and evaluation of language models based on stochastic context‐free grammar for speech recognition
Authors: Hori Chiori , Katoh Masaharu , Ito Akinori , Kohda Masaki
Published: October 2002

This paper deals with the use of a stochastic context‐free grammar (SCFG) for large vocabulary continuous speech recognition; in particular, an SCFG with phrase‐level dependency rules is built. Unlike n‐gram models, the SCFG can describe not only local constraints but also global constraints pertaining to the sentence as a whole, thus making possible language models with great expressive power. However, the inside‐outside algorithm must be used for estimation of the SCFG parameters, which involves a great amount of calculation, proportional to the third power of the number of nonterminal symbols and of the input string length. Hence, due to problems in dealing with extensive text corpora, the SCFG has hardly been applied as a language model for very large vocabulary continuous speech recognition. The proposed phrase‐level dependency SCFG allows a significant reduction of the computational load. In experiments with the EDR corpus, the proposed method proved effective. In experiments with the Mainichi corpus, a large‐scale phrase‐level dependency SCFG was built for a very large vocabulary continuous speech recognition system. Speech recognition tests with a vocabulary of about 5000 words showed that the proposed method could not compare with the trigram model in performance; however, when it was used in combination with a trigram model, the error rate was reduced by 14% compared to the trigram model alone. © 2002 Wiley Periodicals, Inc. Syst Comp Jpn, 33(13): 48–59, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/scj.1172
LOGEMON: The teacher support system in class using web‐based materials—visualization of learning history for teacher aid
Authors: Kanenishi Kazuhide , Mendori Takahiko , Yano Yoneo
Published: October 2002

Continuing spread of the Internet leads to a greater availability of instructional materials that can be retrieved from the Web and it is expected that the volume of such materials will increase even more in the future. Considering these factors, we developed an experimental teacher support system LOGEMON with the purpose of helping the teachers in using Web‐based instructional materials in class. This system makes it possible for the teacher to gather and view the information about the students' progress in learning during the classes, in which Web‐based materials are used. In this paper, we present methods of creating and visualizing the learning histories of individual students. Learning histories are compiled from the browsing histories by using proxy servers and databases. However, proxy log is an abstract file that does not provide information needed by the teachers necessitating search of information from other sources. The learning history is presented to the teacher upon his request with simultaneous visualization. The instructional structure and learning history are presented visually in a superimposed manner to assist the teacher in his diagnosis of students' progress. Experimental results indicate that the visualized learning history provides a better understanding of the state of learning of individual students. LOGEMON is based on the client‐server configuration, in which the database is run on the server and the browser is implemented in the form of the client's interface. © 2002 Wiley Periodicals, Inc. Syst Comp Jpn, 33(13): 60–74, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/scj.1173
Improvements of aspect identification method by matrices
Authors: Sakamoto Hiroyasu
Published: October 2002

In single‐view methods based on three‐dimensional (3D) object geometry models in computer vision, a central problem is determining the correspondence of feature points in the model and the observed image. In this paper the author investigates the features of aspect identification methods used to solve this problem efficiently using matrices, then describes the causes of misidentifications. In addition, the author proposes a new identification matrix which improves this identification method statistically by using singular value decomposition, and general eigenvalues and eigenvectors, demonstrating the validity of the method using mathematical experiments. These improvements allow for a reduction of the computational burden for online identification of aspects while at the same time reducing the misidentification rate. This method can be an identification standard for norms of vectors and matrices. As a result, it is ideal for high‐speed processing using hardware and for use in parallel systems. © 2002 Wiley Periodicals, Inc. Syst Comp Jpn, 33(13): 75–84, 2002; Published online in Wiley InterScience (www.interscience. wiley.com). DOI 10.1002/scj.1174
Selection of projection sets and order of calculation in ordered subsets expectation maximization method
Authors: Ogawa Koichi , Takahashi Masahiro
Published: October 2002

Maximum likelihood‐expectation maximization (ML‐EM) is well known as a method to reconstruct images from projection data, while the ordered subsets algorithm (OS) has been proposed to improve the performance of iterative calculation. In a combination of this algorithm with expectation maximization (OS‐EM), the projection data are divided into subsets, and pixels are updated for each subset according to the projection data; this method achieves recovery of high‐frequency components in few iterations. In this paper, OS‐EM is explored in terms of the dependence of image quality on the manner in which the subsets are built, and the order in which they are then calculated. © 2002 Wiley Periodicals, Inc. Syst Comp Jpn, 33(13): 96–102, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/scj.1176
An analysis of a model of computer viruses spreading via electronic mail
Authors: Okamoto Takeshi , Ishida Yoshiteru
Published: October 2002

In this paper we consider a model of the spread of computer viruses which can spread over a wide area in a short time by electronic mail. In addition to clarifying how a virus spreads, the purpose of this paper is to obtain new ideas about virus countermeasures. In this analysis of how a virus spreads, we use a simple mathematical model and simulations to clarify the changes over time of the number of infections, the relationship between the number of computer connections and the number of infections, the effects of suppressing virus spread by improving the level of user knowledge against viruses, and the effects of suppressing virus spread using antivirus software. © 2002 Wiley Periodicals, Inc. Syst Comp Jpn, 33(14): 81–90, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/scj.1178
Investigation of the genotoxic effect in bone marrow of Swiss albino mice exposed long‐term to pyrimethamine
Authors: Tunca B. , Egeli U. , Aydemir N. , Cecener G. , Bilaloglu R.
Published: October 2002

In the present study, we investigated the genotoxic effect of pyrimethamine, which is a drug used in the therapy of toxoplasmosis and malaria, in bone marrow cells of Swiss albino mice exposed to three doses (1, 4, 8mg/kg) of this agent for eight months orally in vivo. We used a chromosome analysis and micronucleus test for evaluation of genotoxic effect. While a statistically significant change was not determined in numerical chromosome abnormalities, structural chromosome aberrations and micronuclei were increased in a dose‐dependent manner by cytogenetic and statistical evaluations. Teratogenesis Carcinog. Mutagen. 22: 393–402, 2002. © 2002 Wiley‐Liss, Inc.
Antisense inhibition of translation initiation factor 3 reverses its oncogenic potential
Authors: Lei Yi‐xiong , Joseph Pius , Ong Tong‐man
Published: October 2002

Recently we have identified, cloned, and characterized the mouse Translation Initiation Factor 3 (TIF3, GenBank Accession Number AF 271072) as a novel cadmium‐responsive proto‐oncogene. Presently, additional studies regarding the oncogenic potential of TIF3 have been carried out. Transfection of NIH3T3 cells with the pcDNA3.1 expression vector containing the TIF3 cDNA in the sense (5′→3′) orientation resulted in overexpression of the encoded 36 kDa protein. Transfection‐mediated overexpression of TIF3 protein resulted in transformation of the cells as evidenced from the appearance of transformed foci. Cotransfection of the cells with a mixture of plasmid DNA consisting of TIF3 cDNA in the sense and in the antisense orientation resulted in significant inhibition of translation of the TIF3 protein. Antisense (3′→5′) TIF3 mRNA‐mediated inhibition of translation of TIF3 protein, furthermore, resulted in inhibition of TIF3‐mediated transformation of NIH3T3 cells as evidenced from the decrease in the number of transformed foci. These results further confirm that overexpression of TIF3 is oncogenic and the antisense TIF3 mRNA expression reverses its oncogenic potential. Teratogenesis Carcinog. Mutagen. 22:403–409, 2002. Published 2002 Wiley‐Liss, Inc.
Chromosome aberration and sister chromatid exchange in workers of the iron and steel factory of İskenderun, Turkey
Authors: Topaktaş Mehmet , Rencüzoğullari Eyyüp , İla Hasan Basri , Kayraldiz Ahmet
Published: October 2002

The aim of this study was to investigate, by using chromosome aberration (CA) and sister chromatid exchange (SCE) tests, whether or not the workers employed in the İskenderun (Turkey) iron and steel factory have any genotoxic risk. The CA and the SCE were investigated in 48 males employed in a coke ovens unit and 8 males employed in a product side unit of the factory and in control groups. The frequency of CA was higher while the frequency of the SCE was not in all the smoker‐nonsmoker workers than in smoker‐nonsmoker control groups. In addition, there was no significant decrease in the RI, while the MI was significantly lower than in the controls. Teratogenesis Carcinog. Mutagen. 22:411–423, 2002. © 2002 Wiley‐Liss, Inc.
Mutagenicity of bisphenol A (4,4′‐isopropylidenediphenol) in vitro: effects of nitrosylation
Authors: Schrader Timothy J. , Langlois I. , Soper K. , Cherry W.
Published: October 2002

Bisphenol A (4,4′‐isopropylidenediphenol) is a common component of polycarbonate plastics and epoxy resins. Since bisphenol A–containing plastics and resins have found uses in food‐contact items, its potential migration into foodstuffs and possible health consequences have been the focus of many recent studies. However, the potential mutagenic activation of bisphenol A by nitrosylation has received little attention. Incubation of bisphenol A with sodium nitrite under acidic conditions produced a yellow‐brown product. When nitrosylated bisphenol A was tested in the Ames Salmonella/microsome assay at 100 ng to 1 mg/plate, dose‐dependent increases in mutagenicity were found in both TA98 and TA100 Salmonella strains. These results indicated the presence of a direct‐acting mutagenic activity causing both frameshift and base pair mutations, respectively. When compared to colony formation in untreated controls, the addition of rat liver S9 for metabolic activation had little influence on revertant colony formation. Unreacted bisphenol A dissolved in DMSO, acidic buffer, or inactivated nitrosylation solution showed negligible mutagenicity. When the nature of the mutagenic changes was examined using the Ames II™ Assay, a variety of base pair changes was found including T:A to A:T ‐ S9, G:C to A:T ± S9,C:G to A:T ± S9 and C:G to G:C ± S9. Bisphenol A also induced frameshift mutations at G:C sites. In addition, the presence of electrophiles was shown by the production of an intensely coloured orange‐red product upon incubation of nitrosylated bisphenol A with the nucleophile 4‐(4′‐nitrobenzyl)pyridine. These findings suggest that migration of bisphenol A into nitrite containing foodstuffs, or its ingestion in the presence of nitrite, could lead to the formation of mutagenic compounds. Teratogenesis Carcinog. Mutagen. 22: 425–441, 2002. Published 2002 Wiley‐Liss, Inc.
Inhibitory effect of ascorbic acid post‐treatment on radiation‐induced chromosomal damage in human lymphocytes in vitro
Authors: Konopacka Maria , Palyvoda Olena , Rzeszowska‐Wolny Joanna
Published: October 2002

In the present study, the effect of exposure to ascorbic acid (vitamin C) after γ‐ray‐induced chromosomal damage in cultured human lymphocytes was examined to explore the mechanism by which this antioxidant vitamin protects irradiated cells Non‐irradiated lymphocytes were exposed to increasing concentrations of ascorbic acid (1–100 μg/ml) and DNA damage was estimated using chromosomal aberration analysis and the comet assay. The results showed that ascorbic acid did not influence the frequency of chromosomal aberrations in non‐irradiated cells, except at the highest concentration (20 μg/ml), which induced breakage‐type chromosomal aberrations. Vitamin C at the concentration of 50 μg/ml caused DNA damage detected by the comet assay. A significant (34%) decrease in the frequency of chromosomal aberrations was observed in lymphocytes exposed to γ‐radiation and then cultured in the presence of ascorbic acid (1 μg/ml). The removal of DNA breaks in cells exposed to 2 Gy of γ‐radiation was accelerated in the presence of ascorbic acid as determined by the comet assay, suggesting that it may stimulate DNA repair processes. Teratogenesis Carcinog. Mutagen. 22:443–450, 2002. © 2002 Wiley‐Liss. Inc.
Evaluation of the aneugenic potential of the fungicide Ferbam in mice
Authors: Shanthi R. , Krishnamoorthy M.
Published: October 2002

Ferbam, a potent dithiocarbamate fungicide is used as a protectant against a wide variety of fungal diseases in fruits, vegetables, and ornamental plants. The wide‐spread use of this chemical is likely to pollute the environment. Hence, it was planned to test the possible genotoxicity of Ferbam through its aneugenic potential in the in vivo mouse (Mus musculus) test system. Four different doses of Ferbam, namely, 7.5, 15.0, 30.0, 60.0 mg/kg body weight were administered orally to mice Mus musculus suspended in gum tragacanth representing, respectively, 1/16, 1/8, 1/4;, 1/2th of the LD50 value. They were sacrificed at 6‐, 12‐, 24‐, and 48‐h intervals along with a distilled water negative control at 2 mg/kg body weight. Colchicine treated animals were used as positive controls. Bone marrow preparations were made following the standard Hypotonic flame dry Giemsa staining technique to study the dose and time yield effect of Ferbam. The aneugenic potential was evaluated for C‐mitotic effects by scoring the mitotic index, c‐mitoses frequency, anaphase reduction, and hyper/hypodiploidy induction. Ferbam showed a significant increase in the mitotic index and C‐mitoses effects and anaphase decreased at the highest doses of 30 and 60 mg/kg at 12‐ and 24‐h intervals. Colchicine induced significant effects in all the aneugenic parameters observed at all the time intervals. There was no significant induction of either hyperdiploidy or hypodiploidy by Ferbam, unlike colchicine, indicating that the fungicide Ferbam is not aneugenic in the mouse test system. Teratogenesis Carcinog. Mutagen. 22:451–459, 2002. © 2002 Wiley‐Liss, Inc.
Effects of chlorophyllin on mouse embryonic and fetal development in vivo
Authors: García‐Rodríguez Ma. Carmen , Morales‐Ramírez Pedro , Altamirano‐Lozano Mario
Published: October 2002

Chlorophyllin (CHL) has proven that there is antimutagenic and anticarcinogenic activity in several organisms without causing lethal effects. However, there is no information about its effects when it is administered in gestation. In the present study, we assessed possible effects of CHL when it was administered to CD‐1 mice on the 8th day of gestation using the same doses and administration route used in ours previous antimutagenic and antigenotoxic studies. Females were exposed to a single dose of CHL by i.p. injection (20, 40, 50, or 100mg/kg b.w.). On day 18 all dams were subjected to cesarean section and the fetuses were examined with common teratological methods. Results show that CHL‐treatment induced total litter loss and is dose‐dependent, probably due to either the interaction between CHL and some general control mechanisms of embryo development or by an impairment of maternal‐fetal interactions. The analysis of uterine horns of the CHL‐treated females with total litter loss revealed the presence of green rings in the uterus. Results show the inverse relationship between the number of live implants and the frequency of green rings, indicating implantation sites where embryo death and early resorptions occurred. Although CHL was given in a single dose on day 8 in this study, the results indicate that CHL is associated with significant embryo lethality. Teratogenesis Carcinog. Mutagen. 22:461–471, 2002. © 2002 Wiley‐Liss, Inc.
Implantation of MNNG crystals into a Triturus intact limb affects mitotic and labeling indices, regeneration rate, and morphogenesis in the contralateral, regenerating limb
Authors: Keramitsoglou T. , Grispou E. , Margaritis L.H. , Koussoulakos S.
Published: October 2002

Experimental administration of chemical carcinogens to various mammals is highly effective in inducing malignant tumors. In contrast, treatment of regeneration‐competent animals even with much higher doses of the same drugs only exceptionally leads to tumor‐like growth. Usually, carcinogenic materials implanted or injected into a regenerating limb of urodele amphibia interfere with the regenerative process and frequently lead a) to growth retardation or arrest of regeneration, b) to development of a great variety of abnormal regenerates, and c) to generation of accessory, limb‐like structures. Autonomous or experimental incidence of carcinogenesis is extremely low in animals endowed with strong regenerative capabilities. Of exceptional biological significance is the fact that such induced tumors usually regress spontaneously. This unique property of the regeneration‐competent animals to resist carcinogenesis provides opportunities to compare non‐cancerous alterations in the differentiated state of adult cells to those occurring in neoplasia. The mode of action of the chemical carcinogens on limb regeneration has not yet been clarified with certainty at the cellular and the molecular level. Several scientists claim that the above‐mentioned effects might be attributed to local toxic influences of the drugs; therefore the present study was designed to investigate whether the administration of the carcinogen MNNG can affect cell proliferation, histogenesis, and morphogenesis at a region distant from the site of its implantation, even after a relatively long time period. To this end, 40 animals of the species Triturus cristatus had their right hindlimb surgically removed at the distal zeugopod. Then, a small microcrystal (approximately 5 µg) of MNNG was inserted under the ventral aspect of the skin of the left tarsus in 20 of these animals (groups T and A; see below). Two months later, nine of the MNNG‐treated animals were injected intraperitoneally with tritiated thymidine. After 2 h, six of these animals had their right hindlimb amputated at the distal zeugopod, whereas the rest were left to regenerate. The results were evaluated by camera lucida drawings, clearing in methyl benzoate, classical histology, and autoradiography. It was revealed that administration of MNNG at a somatic region (left hindlimb) reduces DNA synthesis and mitosis at a distant place (right hindlimb) even 2 months after MNNG implantation. Despite this, the rate of limb elongation is not substantially reduced. Classical histology revealed normal tissue structure throughout. All regenerated limbs displayed several teratogenic abnormalities. Teratogenesis Carcinog. Mutagen. 22:473–483, 2002. © 2002 Wiley‐Liss, Inc.
Identification of polymorphisms in the human Reprimo gene using public EST data
Authors: Ye Zheng , Parry James M.
Published: October 2002

The human Reprimo gene is a recently identified cytoplasmic protein, which plays an important role in the regulation of p53‐dependent G2 arrest of the cell cycle. Genetic variations in the Reprimo gene that may influence enzyme activity can be of both biological and epidemiological significance. The human expressed sequence tag (EST) database is a wealth of resources, which can be used to rapidly screen for potential polymorphisms in proteins of physiological interest. On the basis of the alignment of human EST sequences, we identified two candidate polymorphisms at nucleotides 824 and 839 in the 3′‐untranslated region of the Reprimo gene. The presence of these polymorphisms was confirmed in a Caucasian population (n=82) by the use of the allele specific polymerase chain reaction (PCR). The rare allele frequency at position 824 (38.4%) is much higher than rare allele frequency at position 839 (3.7%). Our results suggest that the human EST data may serve as a valuable source for the rapid identification of genetic variation. Teratogenesis Carcinog. Mutagen. 22:485–493, 2002. © 2002 Wiley‐Liss, Inc.
Birth order and oral clefts: A meta analysis
Authors: Vieira Alexandre R. , Orioli Iêda M.
Published: October 2002

Background

There is evidence that late birth order is associated with some complex disorders. For orofacial clefts there is no consensus as to whether increased birth order is associated or not. A meta‐analysis of published data on cleft lip or cleft palate (CL/P and CP) was carried out to ascertain whether there is an increased risk for children of high birth order to have an oral cleft.

Methods

All data available with information regarding the frequency of live births and CL/P and CP cases by birth order (1, 2, 3, and 4 or more) were included in the analysis, and the birth order category “1” was considered to be with no risk (OR = 1.0).

Results

Children with higher birth order are more likely to have CL/P and CP with odds ratios increasing with birth order to a peak of 3.0 in children birth order “4 or more.” Results are not different when isolated and syndromic cases are combined.

Conclusions

CL/P and CP occurrence is correlated with increasing birth order. Further studies, taking into consideration sample size and factors such as income status, race, paternal age, vitamin intake, and social habits, should be done to determine conclusively the association between birth order and oral clefts. Teratology 66:209–216, 2002. © 2002 Wiley‐Liss, Inc.
Orofacial clefts and spina bifida: N‐Acetyltransferase phenotype, maternal smoking, and medication use
Authors: Van Rooij Iris A.L.M. , Groenen Pascal M.W. , Van Drongelen Merel , Te Morsche René H.M. , Peters Wilbert H.M. , Steegers‐Theunissen Régine P.M.
Published: October 2002

Background

Orofacial clefts and spina bifida are midline defects with a multifactorial etiology. Maternal smoking and medication use periconceptionally have been studied as risk factors for these malformations. The biotransformation enzyme N‐acetyltransferase 2 (NAT2), plays a part in the inactivation of toxic compounds in cigarette smoke and medication. We investigated maternal NAT2 phenotype and the interaction with smoking and medication use periconceptionally on orofacial cleft and spina bifida risk in offspring.

Methods

In this case‐control study of 45 mothers of orofacial cleft children, 39 mothers of spina bifida children and 73 control mothers, NAT2 acetylator status was determined by measuring urinary caffeine metabolites.

Results

Slow NAT2 acetylators showed no increased risk for orofacial cleft (OR = 1.0, 95% CI: 0.4–2.3) or spina bifida offspring (OR = 0.7, 95% CI: 0.3–1.7) compared to fast NAT2 acetylators. More mothers with orofacial cleft and spina bifida offspring smoked cigarettes (36% and 23% respectively) and used medication periconceptionally (38% and 44% respectively) compared to control mothers (smoking:18%, medication use:19%). No interaction between maternal NAT2 acetylator status and smoking or medication use was observed for orofacial cleft and spina bifida risk.

Conclusions

Maternal smoking and medication use is associated with orofacial cleft risk as well as medication use is with spina bifida. The maternal NAT2 acetylator status, however, was not associated with an increased risk for orofacial cleft or spina bifida offspring, nor in combination with periconceptional smoking or medication use. Teratology 66:260–266, 2002. © 2002 Wiley‐Liss, Inc.