bluuebunny/crossref_metadata_2025 huggingface dataset:
Removal of impulse noise from highly corrupted images by using noise position information and directional information of image
Authors: Matsumoto Tetsuo , Taguchi Akira
Published: November 2002

One excellent method for restoration of images with superposed impulsive noise uses the position information of the impulsive noise for the pixels used for processing and of the processing point. This method consists of two steps. In Step 1, the impulsive noise existing in the image is detected and the noise position image is formed. In Step 2, by using the noise position image formed in Step 1, the filter processing is carried out on the pixels degraded by impulsive noise only with the pixels not affected by the impulsive noise. An excellent procedure for Step 2, using an average filter (PSA filter), has been proposed. However, in the method with an average filter, a uniform weight is provided on all pixels in the filter window. Therefore, if the generation probability of the impulsive noise is increased, the window size cannot be increased even if the filter window size should be increased. Also, an individual image has directionality specific to the image. This directionality is not taken into account in the filter processing. In the present paper, in order to resolve this problem, a PSWA filter is proposed for the filter processing in Step 2 by using the weighted average filter with weights considering the distance from the process point and the directionality of the image. In order to appropriately apply the proposed filter, there are two parameters (window size N and parameter κ) to be set. From experimental investigation, it is found that these two parameters do not depend on the type of the original image but only on the generation probability of the impulsive noise. Further, from the generation probability of the impulsive noise, the method for providing these two parameters is presented specifically. The effectiveness of the proposed method is confirmed through several processing examples. © 2002 Wiley Periodicals, Inc. Electron Comm Jpn Pt 3, 86(3): 33–43, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecjc.1138
Some properties of a nonlinear combiner function: Linear complexity, mutual information, and correlation immunity
Authors: Shiraishi Yoshiaki , Morii Masakatu , Uyematsu Tomohiko , Sakaniwa Kohichi
Published: November 2002

Pseudo‐random number generators are used in spectrum‐spread communications and stream encryption, which is a shared‐key encryption scheme. In particular, the nonlinearly coupled pseudo‐random number generator (NLCRG), in which the outputs from multiple linear feedback shift registers (LFSRs) are nonlinearly coupled, is becoming increasingly important in practical applications because of its structural simplicity. However, even with the NLCRG, its properties, and especially the properties of its output system, are not yet fully understood. Previously, Moriyasu, Morii, and Kasahara proposed a dynamic random number generator (DRG), which is a subclass of NLCRGs, and attempted to analyze its output sequences. The present work provides a further analysis of the DRG; it also positions the DRG in the class of NLCRGs, and discusses the general properties of the NLCRG, such as linear complexity and mutual information. The paper also presents a simple method for constructing a nonlinear circuit with correlation immunity by using a DRG. © 2002 Wiley Periodicals, Inc. Electron Comm Jpn Pt 3, 86(3): 44–56, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecjc.1139
A novel interpolation method for preserving image details by using the fuzzy technique
Authors: Kimura Tomoaki , Taguchi Akira , Murata Yutaka
Published: November 2002

Enlargement processing of digital images is usually carried out by means of an interpolation function obtained by simplification of the sinc function. However, in such an interpolation method, restoration of the high‐frequency components lost in digitizing the images is not carried out at all. Hence, the enlargement causes blurring for images with many edges and detailed signals. For one‐dimensional signals, Carrato and colleagues have proposed an interpolation method in which the discontinuities of the step edge signals are preserved while other signals are linearly interpolated. In this method, no blurring occurs in the expansion processing of strong frames of the images. However, Carrato's method has the following problems. (1) Only the step edges in the image signals are taken into account so that consideration of the detailed signals is insufficient. (2) Extension of the one‐dimensional interpolation method given by Carrato to a two‐dimensional interpolation method has a problem in interpolation at the center of the lattice. In this paper, a method is proposed to accomplish improvement of Carrato's method. With regard to problem (1), the interpolation not only is effective for the step edge signals but also preserves the apex of the peak and valley signals. With regard to problem (2), improvement is planned by directly deriving the interpolation value from the original signals. The proposed interpolation processing is accomplished by describing the processing sequence by a rule. The proposed method consists of two sets of fuzzy reasoning. The proposed method and the conventional interpolation method are compared from the numerical and visual perspectives and the effectiveness of the proposed method is clarified. © 2002 Wiley Periodicals, Inc. Electron Comm Jpn Pt 3, 86(3): 57–66, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecjc.1140
A method for generating complex finite sequences with a small peak sidelobe, using one period of a complex binary orthogonal sequence
Authors: Kirimoto Tetsuo , Mano Seiji
Published: November 2002

Finite sequences with a small sidelobe level of an autocorrelation function are used for the pulse compression of radar signals and the synchronization of pulse communication circuits. This paper demonstrates that a finite sequence with a small peak sidelobe level can be generated through an algebraic approach from a period of a complex binary orthogonal sequence that is obtained by mapping M sequences on GF(2) to complex periodic sequences. The generated sequence is a complex finite sequence comprised of two complex numbers as its components, for which the code length can be given as 2k − 1, where k is a positive integer. By comparing the sidelobe characteristics of the resulting sequence with those of conventional real binary finite sequences for which the components are given as 1 and −1, this paper shows that the peak sidelobe level can be suppressed compared with conventional cases by rendering the finite sequence into a complex binary sequence. In the case of a code length of 7, for example, complex binary finite sequences with a peak sidelobe level lower than the real binary finite sequence shown by Barker by approximately 3.0 dB can be generated. In addition, radio frequency (RF) signals that are code‐modulated with the complex binary finite sequence are produced and their sidelobe characteristics are evaluated from signal waves that are obtained by correlating the signals, with the paper showing a high degree of agreement between experimental and calculated values. © 2002 Wiley Periodicals, Inc. Electron Comm Jpn Pt 3, 86(3): 67–76, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecjc.1141
Image restoration by the family of signal adaptive parametric projection filters
Authors: Tanaka Akira , Imai Hideyuki , Miyakoshi Masaaki
Published: November 2002

Many of the image restoration techniques can roughly be classified into two types: those that are formulated as an optimization problem with regard to the restored image and those that are formulated as an optimization problem with regard to the restoration operator. The former has the advantage that the local information on the image can easily be expressed in the optimization reference. A problem is that the closeness of the image needs to be evaluated indirectly in the observation image space instead of the original image space. On the other hand, in the latter the closeness of the image can be evaluated in the original image space. However, because the optimization reference used to obtain the appropriate restoration operator does not include the information on the individual images, it is difficult to express the local information on the image, in contrast to the former type. Based on such a background, the objective of this paper is to propose a restoration method that can evaluate the closeness of images in the original image space while the local information on the images can be used systematically, based on improvement of the optimization reference of the parametric projection filter family belonging to the latter. The effectiveness of the proposed method is verified by numerical examples. © 2002 Wiley Periodicals, Inc. Electron Comm Jpn Pt 3, 86(3): 77–86, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecjc.1142
Stochastically fastest convergence BCGM‐OR algorithm with a guarantee value
Authors: Fukumoto Masahiro , Kanai Takeshi , Kubota Hajime , Tsujii Shigeo
Published: November 2002

The BCGM‐OR algorithm with a guaranteed value, which optimizes the number of iterations in the block‐orthogonal projection algorithm to which the conjugate gradient technique is applied and which guarantees the stability of operation, provides an upper bound on estimation error through the setting of a guaranteed value. As such, it has significantly improved the estimation accuracy without sacrificing the excellent tracking capacity of the block‐orthogonal projection algorithm. On the other hand, regarding the learning identification method in which the block size used in the block‐orthogonal projection algorithm is set to 1, a step gain (the stochastically fastest step gain) that maximizes the rate of convergence in addition to the setting of a guaranteed value has been demonstrated. Based on the stochastically fastest step gain on the learning identification method, this paper proposes a technique wherein a similar method is introduced into the BCGM‐OR algorithm with a guaranteed value and validates its effectiveness. © 2002 Wiley Periodicals, Inc. Electron Comm Jpn Pt 3, 86(3): 87–98, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecjc.1143
Operating characteristics of a superconducting fault current limiting transformer (SFCLT) and enhancement of electric power system stability
Authors: Kagawa Hiroaki , Hayakawa Naoki , Kashima Naoji , Nagaya Shigeo , Okubo Hitoshi
Published: November 2002

We have been investigating the feasibility of a superconducting fault current limiting transformer (SFCLT) with the functions of fault current suppression and system stability improvement. This paper discusses these functions with consideration of overvoltage and thermal characteristics of SFCLT, and their dependence on recovery time into superconducting state after the quench of SFCLT. Simulation results using EMTP suggested that SFCLT would be coordinated with the background power system under the appropriate superconducting recovery time. The operating parameters of SFCLT were also optimized in a simplified power transmission model system. © 2002 Wiley Periodicals, Inc. Electr Eng Jpn, 142(2): 40–47, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/eej.10070
A study of switching techniques using serial and parallel resistors for power system stabilization
Authors: Kato Toshikazu , Yukita Kazuto , Goto Yasuyuki , Ichiyanagi Katsuhiro , Tabata Yasuto , Ogawa Shigeaki
Published: November 2002

In recent years, electric power systems have become more and more complicated and large‐scale. As a result, transient stability problems and voltage problems in power systems are being taken more seriously. In this paper, switching techniques using serial and parallel resistors for power system stabilization are proposed, and computer simulations and experiments using a transmission simulator were performed. The effectiveness of the stabilization was shown because a system swing was damped off by the on–off control of the series and parallel resistors. © 2002 Wiley Periodicals, Inc. Electr Eng Jpn, 142(2): 59–67, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/eej.10081
Switching of H∞ controller under constraints and decision of controller state at instance of the controller switching
Authors: Komatsu Hayato , Zanma Tadanao , Suzuki Tatsuya , Okuma Shigeru
Published: November 2002

In real control systems, certain constraints are placed on the input, state, and output values. If such constraints are violated, the system may become unstable, in a worst‐case scenario. One of the promising approaches to solving this problem is to switch the controller according to the state of the closed‐loop system. No useful design strategy for each controller, however, has yet been developed. In addition, the determination of the controller state at the instant of controller switching has not been investigated. First, this paper presents a new design methodology which merges the switching control and H∞ controller design into one design algorithm. Second, this paper presents a way of determining the controller state at the instant of controller switching. Finally, the proposed method is applied to force control of a one‐DOF manipulator in order to demonstrate the usefulness of the proposed method. © 2002 Wiley Periodicals, Inc. Electr Eng Jpn, 142(2): 68–75, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/eej.10082
Numerical investigation of the main factor promoting chaotic power swing in a single‐machine, infinite‐bus power system model with the AVR
Authors: Kita Toshihiro
Published: November 2002

This paper presents numerical results on bifurcations and chaotic behavior in a fundamental power system model, a single‐machine infinite‐bus system model with generator excitation control by the first‐order lag AVR. The numerical analysis mainly focuses on revealing the parameter value region where the chaotic behavior is observed. It is shown that the partially linearized model, which is derived by linearizing all of the nonlinear elements except the AVR limiter, exhibits similar bifurcations and chaos. Several simulation results indicate that the mechanisms producing the chaotic behaviors and the bifurcations are the same both in the linearized model and in the original single‐machine infinite‐bus system model for parameter value variation which does not move the equilibrium point from the reference point used for the linearization. © 2002 Wiley Periodicals, Inc. Electr Eng Jpn, 142(2): 21–28, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/eej.10090
Effect of electric field on viscoelastic properties of a disperse system in silicone gel
Authors: Hanaoka Ryoichi , Takata Shinzo , Nakazawa Yuichi , Fukami Tadashi , Sakurai Koji
Published: November 2002

In the electrorheological (ER) fluids of disperse systems, the poor dispersion stability of particles often limits the development of practical application of the fluids. This key problem can be settled by the chemical gelation of ER fluids. In the present study, a dimethylsilicone oil‐based gel containing the nonaqueous ER particles was newly created. The dynamic properties of viscoelasticity in the sample silicone gel were examined under applied DC electric fields of up to 2.0 kV/mm using a sinusoidal oscillating rheometer with low frequencies of 1 Hz or less. The particle behavior and the shearing deformation in the sample gel were also observed using a microscope, a CCD camera, and a color video monitor. When an electric field was applied to the sample gel, the gap between the electrodes was bridged by the chains of particles arranged in the direction of the electric field. Consequently, it is shown that the electroviscoelastic effect of the gel can be controlled by the electric field. © 2002 Wiley Periodicals, Inc. Electr Eng Jpn, 142(2): 1–9, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/eej.10098
A decentralized model following controllers for a class of large‐scale interconnected dynamical systems with uncertainties
Authors: Shigemaru Shinji , Wu Hansheng
Published: November 2002

The problem of decentralized robust tracking and model following is considered for a class of large‐scale interconnected systems with uncertainties. A class of linear decentralized state feedback controllers are proposed for robust tracking of dynamical signals in such a class of uncertain large‐scale systems. The proposed decentralized tracking controllers can guarantee that the tracking errors between each subsystem and local reference model are uniformly ultimately bounded. Moreover, we modify the linear controllers by introducing some nonlinear parts so that the tracking errors decrease asymptotically to zero in the presence of uncertain parameters and interconnection terms. Finally, an illustrative example is given to demonstrate the validity of our results. © 2002 Wiley Periodicals, Inc. Electr Eng Jpn, 142(2): 48–58, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/eej.10101
A method for voltage stability‐constrained optimal power flow (VSCOPF)
Authors: Okamoto Hiroshi , Tanabe Ryuya , Tada Yasuyuki , Sekine Yasuji
Published: November 2002

This paper presents a novel formulation for solving optimal power flow (OPF) problems with voltage stability constraints. The proposed Voltage Stability Constrained OPF (VSCOPF) formulation is based on voltage sensitivity with respect to total load demand representing the gradient of the P‐V curve at the operating point. In the formulation, voltage constraints are given by a set of equality constraints which must be satisfied by the voltage sensitivity. Since the voltage stability constraints retain a sparse matrix structure, the method based on the proposed OPF formulation may effectively solve large‐scale problems. The feasibility and effectiveness of the proposed method are demonstrated on test problems with 2‐, 49‐, and 2312‐bus systems. © 2002 Wiley Periodicals, Inc. Electr Eng Jpn, 142(2): 29–39, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/eej.10125
Stabilization control of multi‐machine power systems by adaptive power system stabilizer using frequency domain analysis
Authors: Senjyu Tomonobu , Yamashita Takahiro , Uezato Katsumi
Published: November 2002

To improve electric power system transient stability, synchronous generators are generally equipped with controllers such as AVR, PSS, and GOV. Fixed parameter controllers degrade control performance, since various oscillation modes occur depending on system conditions.

This paper presents an adaptive power system stabilizer (PSS) using frequency domain analysis for improving the transient stability of a multimachine system. In the proposed method, first, the frequency components of the generator swings are detected by the FFT. The conventional PSS parameters are tuned online by a fuzzy controller and frequency domain analysis. We verify the proposed adaptive PSS using frequency domain analysis, which can damp the generator swings effectively. © 2002 Wiley Periodicals, Inc. Electr Eng Jpn, 142(2): 10–20, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/eej.10129
Jaw transformation with gain of symmetry after Dlx5/Dlx6 inactivation: Mirror of the past?
Authors: Beverdam Annemiek , Merlo Giorgio R. , Paleari Laura , Mantero Stefano , Genova Francesca , Barbieri Ottavia , Janvier Philippe , Levi Giovanni
Published: November 2002

Summary: In modern vertebrates upper and lower jaws are morphologically different. Both develop from the mandibular arch, which is colonized mostly by Hox‐free neural crest cells. Here we show that simultaneous inactivation of the murine homeobox genes Dlx5 and Dlx6 results in the transformation of the lower jaw into an upper jaw and in symmetry of the snout. This is the first homeotic‐like transformation found in this Hox‐free region after gene inactivation. A suggestive parallel comes from the paleontological record, which shows that in primitive vertebrates both jaws are essentially mirror images of each other. Our finding supports the notion that Dlx genes are homeotic genes associated with morphological novelty in the vertebrate lineage. genesis 34:221–227, 2002. © 2002 Wiley‐Liss, Inc.
Caenorhabditis elegans Aurora A kinase AIR‐1 is required for postembryonic cell divisions and germline development
Authors: Furuta Tokiko , Baillie David L. , Schumacher Jill M.
Published: November 2002

Summary: Many kinases are required for progression through the eukaryotic cell cycle. The Aurora kinases comprise a highly conserved family of serine/threonine kinases that have been implicated in chromosome segregation and cytokinesis in several organisms. We have isolated a sterile Caenorhabditis elegans mutant in which the majority of the locus encoding the Aurora A kinase air‐1 has been deleted. Complementation tests with previously isolated sterile mutations in the air‐1 genetic interval demonstrate that the air‐1 and let‐412 loci are identical. Previous analysis of AIR‐1 function by RNA‐mediated interference (RNAi) has shown that AIR‐1 is required for embryonic survival. The characterization of the three sterile air‐1 mutant alleles described here extends these studies by revealing an allelic series that differentially affects postembryonic cell divisions and germline development. genesis 34:244–250, 2002. © 2002 Wiley‐Liss, Inc.
Conservation of the function of DMRT1 regulatory sequences in mammalian sex differentiation
Authors: Boyer Alexandre , Dornan Saffron , Daneau Isabelle , Lussier Jacques , Silversides David W.
Published: November 2002

Summary: Among genes involved in sex determination and differentiation, DMRT1 is the only one characterized to date containing a domain (the DM domain) that is conserved between phyla. To study DMRT1 transcriptional regulation within mammalian phyla, we generated transgenic mice that express green fluorescent protein (GFP) or Cre‐recombinase (Cre) under the control of 2.6 kb of pig DMRT1 5′ flanking sequences (pDMRT1p‐GFP and pDMRT1p‐Cre, respectively). Within the pDMRT1p‐GFP positive mice, GFP expression was observed in the XY genital ridge by embryonic day 11.5 (e11.5) and remained detectable during testis embryonic development to birth. GFP expression was restricted within testis cords as soon as cords were detectable. No fluorescence was observed in developing ovaries, although more sensitive RT‐PCR analysis revealed transgene expression in embryonic ovaries from e13.5 to e15.5. RT‐PCR performed on fluorescent activated cell sorter (FACS)‐purified GFP cells from e14.5, e17.5, and e19.5 developing testis showed that GFP expression was restricted to cells expressing the endogenous mouse Dmrt1. GFP cells also expressed Mis and Oct4, showing that the transgene is expressed in both Sertoli cell and germ cell compartments. In postnatal testis, transgene expression was detectable by GFP fluorescence from P0 to P21 in mice heterozygous for the transgene and through adulthood in mice homozygous for the transgene. In pDMRT1p‐Cre positive mice, Cre expression was detected within the genital ridges of both XY and XX embryos. We conclude that DMRT1 regulatory mechanisms during sexual differentiation are functionally conserved across mammalian evolution. The transgenic mouse lines described should provide useful marker systems for studies involving Dmrt1 gene expression during sex differentiation. genesis 34:236–243, 2002. © 2002 Wiley‐Liss, Inc.
vavCre Transgenic mice: A tool for mutagenesis in hematopoietic and endothelial lineages
Authors: Georgiades Pantelis , Ogilvy Sarah , Duval Hélène , Licence Diana R. , Charnock‐Jones D. Stephen , Smith Stephen K. , Print Cristin G.
Published: November 2002

Summary: Cre transgenic mice can be used to delete gene sequences flanked by loxP sites in specific somatic tissues. We have generated vavCre transgenic mice, which can be used to inactivate genes specifically in adult hematopoietic and endothelial cells. In these animals, a Cre transgene is expressed under control of murine vav gene regulatory elements. To assess their usefulness, vavCre transgenic mice were bred with R26R mice, which express a lacZ reporter gene only in cells where Cre‐mediated recombination has occurred. VavCre/R26R double‐heterozygous offspring were analyzed by β‐galactosidase histochemistry and flow cytometry. VavCre‐mediated recombination occurred in most hematopoietic cells of all hematopoietic organs, including the hematopoietic progenitor‐rich bone marrow. Recombination also occurred in most endothelial and germ cells, but only rarely in other cell types. The recombination in both hematopoietic and endothelial lineages may partly reflect their putative shared ontogeny and provides a unique tool for simultaneous pan‐hematopoietic and endothelial mutagenesis. genesis 34:251–256, 2002. © 2002 Wiley‐Liss, Inc.
Dynamic in vivo imaging of postimplantation mammalian embryos using whole embryo culture
Authors: Jones E.A.V. , Crotty D. , Kulesa P.M. , Waters C.W. , Baron M.H. , Fraser S.E. , Dickinson M.E.
Published: November 2002

Summary: Due to the internal nature of mammalian development, much of the research performed is of a static nature and depends on interpolation between stages of development. This approach cannot explore the dynamic interactions that are essential for normal development. While roller culture overcomes the problem of inaccessibility of the embryo, the constant motion of the medium and embryos makes it impossible to observe and record development. We have developed a static mammalian culture system for imaging development of the mouse embryo. Using this technique, it is possible to sustain normal development for periods of 18–24 h. The success of the culture was evaluated based on the rate of embryo turning, heart rate, somite addition, and several gross morphological features. When this technique is combined with fluorescent markers, it is possible to follow the development of specific tissues or the movement of cells. To highlight some of the strengths of this approach, we present time‐lapse movies of embryonic turning, somite addition, closure of the neural tube, and fluorescent imaging of blood circulation in the yolk sac and embryo. genesis 34:228–235, 2002. © 2002 Wiley‐Liss, Inc.
X‐chromosome inactivation during spermatogenesis is regulated by an Xist/Tsix‐independent mechanism in the mouse
Authors: McCarrey John R. , Watson Cathy , Atencio Julia , Ostermeier G. Charles , Marahrens York , Jaenisch Rudolf , Krawetz Stephen A.
Published: November 2002

Summary: Transcriptional inactivation of the single X chromosome occurs in spermatogenic cells during male meiosis in mammals and has been shown to be coincident with expression of the Xist gene in spermatogonia and spermatocytes in mice. However, male mice carrying an ablated Xist gene show normal fertility. Here we examined expression from the Xist locus during spermatogenesis in wild‐type mice and detected sense (Xist), but not antisense (Tsix) transcripts. In addition, we examined expression and chromatin conformation of X‐linked structural genes in meiotic and postmeiotic spermatogenic cells from wild‐type and Xist‐ mice and found no differences associated with the absence of a functional Xist gene. These results, along with the formation of a morphologically normal XY body in primary spermatocytes in Xist‐ mice, indicate that a functional Xist gene is not required for X‐chromosome inactivation during spermatogenesis and that this process is therefore regulated by a different mechanism than that which regulates X‐chromosome inactivation in female embryonic cells. genesis 34:257–266, 2002. © 2002 Wiley‐Liss, Inc.
ER‐based double iCRE fusion protein allows partial recombination in forebrain
Authors: Casanova Emilio , Fehsenfeld Sandra , Lemberger Thomas , Shimshek Derya R. , Sprengel Rolf , Mantamadiotis Theo
Published: November 2002

The original article to which this Erratum refers was published in genesis (2002) 34(3) 208 – 214
Retrospective analysis of non‐A–E hepatitis: Possible role of hepatitis B and C virus infection
Authors: He Zhongping , Zhuang Hui , Wang Xiaohong , Song Shujing , Dong Qingming , Yan Jie , Buehring Gertrude C. , Luo Guangxiang
Published: November 2002

In an effort to determine the cause of non‐A–E hepatitis, a retrospective study was undertaken on a group of patients with hepatitis but without serological infection markers of hepatitis viruses A–E. A total of 60 patients admitted to Beijing Ditan Hospital during the period of September 1997 and September 1999 were chosen for this study. These patients were diagnosed as either acute or chronic hepatitis, but no serological markers of hepatitis viruses A–E were detected. Since TT virus (TTV), human parvovirus B19 (B19), SEN virus (SENV), and GB virus C/HGV were reported to be associated with hepatitis, attempts were made to detect the presence of these viruses in the sera of patients with non‐A–E hepatitis by a nested polymerase chain reaction (nPCR) method. Also, more sensitive nPCR and RT‐nPCR methods were used to determine HBV DNA and HCV RNA in these patients. Results derived from these analyses demonstrate that HBV DNA was detected in most of these patients (47/60, 78.3%), suggesting that HBV infection played a major role in occult non‐A–E hepatitis and detection of HBV DNA by more sensitive PCR methods such as nPCR should be considered for diagnosis of HBV infection. In addition, HCV RNA was detected in three (5%) of these patients. However, GBV‐C (HGV) RNA was not detected, and TTV, B19, and SENV appear not to be associated with non‐A–E hepatitis, as the prevalence rates of these viruses in patients with non‐A–E hepatitis were similar to those in patients with viral hepatitis A–E. The results from this study indicate that co‐infection of TTV or B19 with HBV did not increase the severity of the disease. J. Med. Virol. 69:59–65, 2003. © 2003 Wiley‐Liss, Inc.
TT virus infection in healthy children, children after blood transfusion, and children with non‐A to E hepatitis or other liver diseases in Taiwan
Authors: Hsu Hong‐Yuan , Ni Yen‐Hsuan , Chen Huey‐Ling , Kao Jia‐Horng , Chang Mei‐Hwei
Published: November 2002

Serum samples from healthy and diseased children were studied for the presence of TTV DNA by nested PCR using primer sets generated from N‐22 region and from the untranslated region (UTR) of the viral genome. N‐22 positive TTV DNA was detectable in 33 (27%) of 122 healthy children, 47 (73.4%) of 64 polytransfused thalassemic children, 37 (46.3%) of 80 children who received transfusion during cardiac surgery, 8 (42.1%) of 19 non‐A to E hepatitis, 10 (33.3%) of 30 HBV carrier children, and 5 (15.6%) of 32 infants with biliary atresia. A much higher prevalence of TTV DNA with rates varying from 78–100% in the above study groups was observed using the UTR primers. For children with N‐22 positive TTV DNA, biochemical assessment of isolated TTV viremia in thalassemic children or children transfused during surgery showed no convincing association between raised ALT levels and TTV viremia. Coinfection with TTV in chronic HCV‐infected or HBV‐infected children did not result in higher peak ALT levels during follow‐up, suggesting that TTV has no synergistic pathogenic effect. The phylogenetic analysis of the N‐22 positive TTV DNA isolates revealed that most isolates from healthy children, children transfused during surgery, and non‐A to E fulminant hepatitis children were type 1 TTV. These results indicate that TTV infection in children was significantly associated with transfusion. TTV infection is highly prevalent in early childhood in Taiwan but plays a minimal role in the induction of hepatitis in children. J. Med. Virol. 69:66–71, 2003. © 2003 Wiley‐Liss, Inc.
Histological improvement of chronic liver disease after spontaneous serum hepatitis C virus clearance
Authors: Sugiyasu Yasunori , Yuki Nobukazu , Nagaoka Takayuki , Yamashiro Masatoshi , Kawahara Kunimitsu , Iyoda Kenya , Kakiuchi Yoshimi , Kaneko Akira , Yamamoto Keiji , Hikiji Kazumasa , Kato Michio
Published: November 2002

The long‐term histological and virological outcomes of spontaneous circulating hepatitis C virus (HCV) clearance were studied in chronic liver disease. Between 1979 and 1984, three patients underwent laparoscopy for chronic non‐A, non‐B liver disease, and two were found to have cirrhosis and one with chronic active hepatitis. After HCV assays became available in 1990, they were positive persistently for HCV antibody without serum HCV RNA. Reductions of antibody levels to HCV core and/or nonstructural proteins were observed, and liver biopsies were undertaken between 1995 and 2000. Liver biopsies at 11–19 years after laparoscopy disclosed marked alleviation of liver inflammation and fibrosis in each case although a low grade of inflammation remained. The two patients with cirrhosis no longer showed histological features of cirrhosis, and the poor liver function in one patient had been ameliorated. Liver specimens from two patients were subjected to polymerase chain reaction to detect positive and negative HCV RNA strands and hepatitis B virus DNA. Only the positive HCV RNA strand was detected for one patient who had previously cirrhosis. Liver specimens were examined from another six nonviremic HCV‐seropositive individuals without chronic liver disease. Five patients displayed low‐grade liver inflammation without evident fibrosis, but none had any viral genome in the liver. These findings suggest that spontaneous circulating HCV clearance in chronic liver disease confers favorable liver histological outcome, although occult HCV infection persists. J. Med. Virol. 69:41–49, 2003. © 2003 Wiley‐Liss, Inc.
Ethnic variation in type of genital herpes simplex virus infection in a South London genitourinary medicine clinic
Authors: Strutt M. , Bailey J. , Tenant‐Flowers M. , Graham D. , Zuckerman M.
Published: November 2002

The aims of this study were to investigate the prevalence of herpes simplex virus (HSV) types 1 and 2 in the study population and correlate the results with clinical and demographic details. Consecutive HSV isolates from 334 clinic attendees were typed by immunofluorescence. Patient information was collected from the case notes. Overall, HSV‐1 was isolated from 48 and HSV‐2 from 287 samples, respectively. There was no significant difference in isolation rates according to gender. However, 33% of white patients' isolates typed as HSV‐1, while only 6% of the isolates from the black population were HSV‐1 (P < 0.001). Initial infections were seen in 81% of HSV‐1 infections and 48% of HSV‐2 infections, respectively. A wide discrepancy was observed in the prevalence of HSV‐1 and HSV‐2 infections between the ethnic groups in this population, which was not explained in terms of gender or age. This may reflect different exposure to HSV‐1 in childhood or different sexual practices. The increased prevalence in genital HSV‐1 reported in recent studies was not seen in this population. However, the differing proportions of primary and first episode infections may reflect a changing epidemiology. J. Med. Virol. 69:108–110, 2003. © 2003 Wiley‐Liss, Inc.
Respiratory syncytial virus enhances respiratory allergy in mice despite the inhibitory effect of virus‐induced interferon‐γ
Authors: Barends Marion , Boelen Anita , de Rond Lia , Dormans Jan , Kwakkel Joan , van Oosten Marijke , Neijens Herman J. , Kimman Tjeerd G.
Published: November 2002

In mice, respiratory syncytial virus (RSV) infection during allergic provocation aggravates the allergic Th2 immune response, characterised by production of interleukin (IL)‐4, IL‐5, and IL‐13, and eosinophilic inflammation. This enhancement of the Th2 response occurs simultaneously with a strong RSV‐induced Th1 cytokine response (IL‐12 and IFN‐γ). The present study investigated whether IFN‐γ and IL‐12 are critically involved in this RSV‐enhanced OVA allergy. Therefore, IFN‐γR‐ and IL‐12‐deficient mice (both on a 129/Sv/Ev background) were sensitised and challenged with ovalbumin (OVA) and infected with RSV during the OVA challenge period. Neither gene deletion affected the development of ovalbumin‐induced allergic inflammation in mice. However, when OVA‐allergic IFN‐γR deficient mice were infected with RSV, an increased pulmonary eosinophilic infiltrate and increased IL‐4 and IL‐13 mRNA expression in lung tissue were observed compared with identically treated wild‐type mice. In contrast, deficiency of IL‐12 did not aggravate the Th2 immune and inflammatory response in OVA/RSV‐treated mice, compared with wild‐type. In conclusion, the virus‐induced IFN‐γ response diminishes the Th2 inflammatory response during OVA allergy but fails to prevent totally the enhancement of the OVA allergy by RSV. In contrast, IL‐12 is not involved in inhibiting nor increasing the RSV‐enhanced allergy in 129/Sv/Ev mice. J. Med. Virol. 69:156–162, 2003. © 2003 Wiley‐Liss, Inc.
Case report: Rapid ante‐mortem diagnosis of a human case of rabies imported into the UK from the Philippines
Authors: Smith Jemma , McElhinney Lorraine , Parsons Graham , Brink Nicola , Doherty Tom , Agranoff Dan , Miranda Mary Elizabeth , Fooks Anthony R.
Published: November 2002

The United Kingdom is free from rabies, with the last human death from indigenous rabies recorded in 1902. However, between 1946 and 2000, 20 deaths were reported in the United Kingdom in people who were bitten and infected while abroad in rabies endemic areas. The rapid diagnosis of suspected human rabies cases influences the use of anti‐rabies post‐exposure prophylaxis for potential contacts with the victim. In addition, the occurrence of a human rabies case requires urgent investigation to support patient management policies. In May 2001, a case of human rabies imported into the United Kingdom from the Philippines was identified. A 55‐year‐old man was admitted to University College Hospital, London, with clinical symptoms and a history consistent with exposure to rabies. Saliva, cerebrospinal fluid), and skin biopsies (from the wound site and nape of the neck) were submitted for conventional ante‐mortem diagnostic techniques. Established diagnostic techniques, including the fluorescent antibody test (FAT), mouse inoculation test, (MIT) and the rabies tissue culture inoculation test (RTCIT), failed to detect the virus. In contrast, hemi‐nested reverse transcription‐polymerase chain reaction (RT‐PCR), followed by automated sequencing confirmed the presence of classical rabies virus (genotype 1) in both the saliva and skin specimens within 36 hr of sample submission. Subsequent phylogenetic analysis demonstrated that this isolate was closely related to that of canine variants currently circulating in the Philippines. J. Med. Virol. 69:150–155, 2003. © 2003 Wiley‐Liss, Inc.
Junin virus‐induced astrocytosis is impaired by iNOS inhibition
Authors: Gómez Ricardo M. , Yep Alejandra , Schattner Mirta , Berría María I.
Published: November 2002

Because Junin virus (JV) experimental encephalitis of mice and rats is characterized by mild histopathological changes that do not seem to justify per se lethality after intracerebral infection, such a murine model seems adequate to investigate the potential role of inducible nitric oxide synthase (iNOS) as a pathogenic factor. Concomitant with a predominant astrocyte reaction, increased immunoperoxidase expression of iNOS, mitochondrial superoxide dismutase (SODm) and glutathione peroxidase (GPX) was disclosed in brain of mice infected with JV strain #44. When specific inhibition of iNOS was achieved by intraperitoneal administration of amino guanidine (AG), significantly greater mortality was observed in treated animals (70% vs. 40%), together with similar infective titers (∼107 PFU/g) but lower astrocytosis, as shown by glial fibrillary acidic (GFAP) labeling. As regards SODm and GPX immunochemical expression in neurons, no differences were found between mice with or without AG treatment. The present results suggest that the apparent protective role of nitric oxide (NO), when synthesized by iNOS, is unrelated to reduced viral replication but rather to enhanced astrocyte activation behaving as a beneficial cell response to virus‐induced CNS damage. J. Med. Virol. 69:145–149, 2003. © 2003 Wiley‐Liss, Inc.
Simultaneous detection of influenza A, B, and C viruses, respiratory syncytial virus, and adenoviruses in clinical samples by multiplex reverse transcription nested‐PCR assay
Authors: Coiras M.T. , Pérez‐Breña P. , García M.L. , Casas I.
Published: November 2002

The clinical presentation of infections caused by the heterogeneous group of the respiratory viruses can be very similar. Thus, the implementation of virological assays that rapidly identify the most important viruses involved is of great interest. A new multiplex reverse transcription nested‐polymerase chain reaction (RT‐PCR) assay that is able to detect and type different respiratory viruses simultaneously is described. Primer sets were targeted to conserved regions of nucleoprotein genes of the influenza viruses, fusion protein genes of respiratory syncytial viruses (RSV), and hexon protein genes of adenoviruses. Individual influenza A, B, and C viruses, RSV (A and B), and a generic detection of the 48 serotypes of adenoviruses were identified and differentiated by the size of the PCR products. An internal amplification control was included in the reaction mixture to exclude false‐negative results due to sample inhibitors and/or extraction failure. Detection levels of 0.1 and 0.01 TCID50 of influenza A and B viruses and 1–10 molecules of cloned amplified products of influenza C virus, RSV A and B, and adenovirus serotype 1 were achieved. The specificity was checked using specimens containing other respiratory viruses and no amplified products were detected in any case. A panel of 290 respiratory specimens from the 1999–2000 and 2000–2001 seasons was used to validate the assay. Accurately amplifying RNA from influenza and RSV prototype strains and DNA from all adenovirus serotypes demonstrates the use of this method for both laboratory routine diagnosis and surveillance of all these viruses. J. Med. Virol. 69:132–144, 2003. © 2003 Wiley‐Liss, Inc.
Identification of a novel promoter in the E2 open reading frame of the human papillomavirus type 18 genome
Authors: Kim Kelly Y. , Taylor Milton W.
Published: November 2002

Northern blot and RT‐PCR analyses indicated that the human papillomavirus E4 open reading frame is expressed in HeLa cells. Because integration at the E1 or E2 open reading frame would place the viral upstream regulatory region downstream of the viral late genes, the expression of E4 in HeLa cells is most likely regulated by host cellular promoter(s) or unidentified viral promoter(s) in the E2 region. Primer extension analysis and transient transfection experiments with luciferase reporter constructs under the transcriptional control of various subgenomic fragments of HPV‐18 were carried out to identify and characterize functional promoters within the E2 region. The in vivo activity of a novel promoter located within the 5′‐end region of the E2 open reading frame of human papillomavirus type 18 is demonstrated. J. Med. Virol. 69:122–131, 2003. © 2003 Wiley‐Liss, Inc.
Human papillomavirus DNA detection in the management of women with twice mildly abnormal cytological smears
Authors: Ho Linda , Terry George , Londesborough Philip , Cuzick Jack , Lorenzato Felipe , Singer Albert
Published: November 2002

This study was undertaken to investigate the value of HPV testing in women referred with two abnormal smears that were graded as mild dyskaryosis or less who attended for at least three follow‐up visits. One hundred forty‐nine women were included in the study and a total of 39 high‐grade lesions including one cancer were detected. All of these were found to be associated with the persistent presence of one or more of 13 high‐risk human papillomavirus types (HPV) as detected by a multiplex type specific PCR technique. Two high‐grade lesions were initially missed by cytology. In contrast, no cytological or histological evidence of high‐grade lesions was found during a follow‐up period of up to 8 years in 62 women with no high‐risk HPV infection or in 38 women with only transient high‐risk HPV infection. The utility of high‐risk HPV detection in the management of women presenting with mild cytological abnormalities is discussed. J. Med. Virol. 69:118–121, 2003. © 2003 Wiley‐Liss, Inc.
Correlation between HHV‐6 reactivation and multiple sclerosis disease activity
Authors: Chapenko Svetlana , Millers Andrejs , Nora Zaiga , Logina Inara , Kukaine Rita , Murovska Modra
Published: November 2002

This study examined the association between HHV‐6 infection and multiple sclerosis (MS) and the relationship between HHV‐6 reactivation and disease activity. The frequency of HHV‐6 genomic sequences in peripheral blood mononuclear cells (PBMCs), the incidence of plasma viremia (nPCR), the transcription of viral mRNA in PBMCs (RT‐PCR), the presence of antiviral IgM and IgG class antibodies in the plasma (IFA) of 16 relapsing/remitting and secondary progressive MS patients were studied in comparison with clinical manifestations of the disease, magnetic resonance imaging (MRI) of brain, and serum interleukin (IL)‐12 concentrations (ELISA). The prevalence of HHV‐6 infection was significantly higher in patients with MS (16/26) than in patients with other neurological diseases (6/21) and in blood donors (43/150). HHV‐6 reactivation was found during periods of disease activity with Gadolinium‐enhancing lesions on MRI in both relapsing/remitting and secondary progressive MS (10/13; 76.9%). In patients with active MS disease, serum concentrations of IL‐12 were significantly higher in those patients with active HHV‐6 infection than in patients with latent infection. The data confirm an association between HHV‐6 infection and MS and show a correlation between HHV‐6 reactivation and disease activity in relapsing/remitting and secondary progressive MS. The risk of an exacerbation of MS was significantly higher (P < 0.005) in patients with active HHV‐6 infection than in patients with latent infection. A clear correlation between HHV‐6 reactivation and serum IL‐12 concentrations during disease activity has been demonstrated. The results suggest that HHV‐6 reactivation is implicated in exacerbation of MS, possibly through modulation of IL‐12 synthesis. J. Med. Virol. 69:111–117, 2003. © 2003 Wiley‐Liss, Inc.
Generation of an HFRS patient‐derived neutralizing recombinant antibody to Hantaan virus G1 protein and definition of the neutralizing domain
Authors: Liang Mifang , Mahler Michael , Koch Joachim , Ji Yan , Li Dexin , Schmaljohn Connie , Bautz Ekkehard K.F.
Published: November 2002

Hantaan virus (HTNV) in the Hantavirus genus, family Bunyaviridae, is the major cause of severe hemorrhagic fever with renal syndrome (HFRS). We prepared a combinatorial phage display library of human Fabs to HTNV from RNA extracted from the blood lymphocytes of a convalescent HFRS patient. We selected two G1 glycoprotein‐specific clones and one nucleocapsid protein (N)‐specific clone from the Fab library for further studies. The human Fab antibodies were converted to IgG form in baculovirus/insect cells system by using cassette vectors that we developed earlier. Characterization of the recombinant antibodies revealed that the two G1‐specific IgGs, could bind to and neutralize HTNV but not Seoul virus (SEOV). The N‐specific IgG did not neutralize either HTNV or SEOV. Sequence analysis revealed that the two G1‐specific clones differed by only one predicted amino acid in their complementarity determining regions, CDR3. Epitope mapping studies were carried out with one of the two G1‐specific clones and synthetic peptides representing portions of HTNV G1. Results indicated that the recombinant antibody recognizes the core amino acid sequence LTKTLVIGQ, which is found near the C‐terminus of HTNV G1. These results are the first to define a neutralizing epitope on the G1 protein of HTNV using an antibody derived from an HFRS patient. J. Med. Virol. 69:99–107, 2003. © 2003 Wiley‐Liss, Inc.