bluuebunny/crossref_metadata_2025 huggingface dataset:
Allergenic Characterization of Tropomyosin from the Dusky Brown Cockroach,Periplaneta fuliginosa
Authors: Jeong Kyoung Yong , Hwang Heeyu , Lee Jongweon , Lee In-Yong , Kim Dong Soo , Hong Chein-Soo , Ree Han-Il , Yong Tai-Soon
Published: July 2004

Household arthropods are one of the most common causes of allergic diseases. Four species of cockroaches are found to reside in Korean homes, but published work deals almost exclusively with the German and American cockroaches. This study was undertaken to investigate the cross-reactive allergenic components of the dusky brown cockroach,Periplaneta fuliginosa. Enzyme-linked immunosorbent assay (ELISA) inhibition and immunoblot analyses for the dusky brown cockroach were performed withBlattella germanicaandDermatophagoides farinaeallergic sera. cDNA encoding tropomyosin, which is a well known cross-reactive pan-allergen, was cloned by reverse transcriptase PCR, and recombinant protein was produced by using a pET-28b expression system. Native tropomyosin was purified by ammonium sulfate fractionation and electroelution. The immunoglobulin E (IgE) reactivities of native and recombinant tropomyosins were compared by an ELISA inhibition study. All 30 sera tested showedP. fuliginosa-specific IgE, and the IgE-binding reactivity of theP. fuliginosaextract was inhibited as much as 79.4% by aB. germanicaextract and as much as 63.3% by aD. farinaeextract. The deduced amino acid sequence of cloned cDNA was identical with that ofPeriplaneta americanatropomyosin (98.5% nucleotide sequence identity). Seven of 26 (26.9%) allergic sera had IgE specific for recombinant protein, and the maximum inhibition ofP. fuliginosa-specific IgE achieved with recombinant tropomyosin was 37.7% at an inhibitor concentration of 10 μg/ml. Native tropomyosin inhibited the binding of IgE to theP. fuliginosa,B. germanica, andD. farinaeextracts by 65.0, 51.8, and 39% at an inhibitor concentration of 1 μg/ml.P. fuliginosaappears to possess allergens that are highly cross-reactive with allergens ofB. germanicaandD. farinae. Tropomyosin was found to be a major allergenic component accounting for the cross-reactivity between cockroaches and dust mites.
Development of a Macroarray To Specifically Analyze Immunological Gene Expression in Swine
Authors: Ledger Terence N. , Pinton Philippe , Bourges Dorothée , Roumi Patrick , Salmon Henri , Oswald Isabelle P.
Published: July 2004

DNA arrays are useful tools for simultaneously studying the expressions of a large number of genes. Herein, we describe the construction and the optimization of conditions for a low-density DNA macroarray specific for the porcine immune system. This specific DNA macroarray contains 63 gene products, including 20 cytokines, 11 chemokines, and 12 immunologically relevant receptors. It was constructed by designing gene-specific oligonucleotide primers from porcine sequences available in the EMBL or TIGR expressed sequence tag data bank and using primers from conserved regions of aligned sequences from other species for sequences unavailable for swine. Amplicons produced by reverse transcription-PCR were cloned, sequenced, and spotted onto nylon filters. A trial DNA array was first produced to optimize the intensity, specificity, and variability of signals from amplicons amplified with either gene-specific or universal primers. The DNA macroarray was then validated by comparing the gene expression profile of nonstimulated peripheral blood mononuclear cells (PBMCs) to that of phorbol 12-myristate 13-acetate and ionomycin (PMA-Iono)-stimulated PBMCs from three different animals over a 48-h time period. As already described for more conventional techniques, we showed that certain genes, such as those for CD40, gamma interferon, interleukin 2 (IL-2), the IL-2 receptor, and tumor necrosis factor alpha, were upregulated in PMA-Iono-stimulated PBMCs. A detailed analysis also indicated a downregulation of several genes which are expressed mainly by macrophages (IL-1, IL-8, AMCF-1, natural-resistance-associated macrophage protein, neutrophil chemotactic protein, DAP-12, and monocyte chemoattractant protein) in samples stimulated for 24 h with PMA-Iono compared to their levels of expression in control samples. These results indicate that the DNA macroarray that we constructed can be a useful tool for simultaneously monitoring the mRNA expression of immunologically relevant genes in different porcine samples.
Evaluation of Recombinant Antigen-Based Assays for Diagnosis of Bullous Autoimmune Diseases
Authors: D'Agosto G. , Latini A. , Carducci M. , Mastroianni A. , Vento A. , Fei P. Cordiali
Published: July 2004

The diagnosis of autoimmune bullous diseases is based on clinical observation and on the presence of autoantibodies directed to molecules involved in the adhesion systems of the skin. Immunofluorescence assays are the currently accepted method for detection of autoantibodies; such assays depend greatly on the skill of operators and are difficult to standardize. Recombinant desmoglein-1 (Dsg1), Dsg3, and BP180 peptides, the main autoantigens in pemphigus or bullous pemphigoid, have been used to develop new quantitative enzyme immunoassays (EIA) for the detection of specific antibodies. The present study was undertaken to evaluate the sensitivity and specificity of these immunoassays and to determine the correlation between the results and the clinical aspects of diseases. Serum samples from patients with pemphigus vulgaris, pemphigus foliaceus, bullous pemphigoid, or mucous membrane pemphigoid, from healthy individuals, and from patients with unrelated autoimmune conditions were tested. Anti-desmoglein reactivity was detected in all the patients with pemphigus and in none of the controls. Patients with the more benign form of cutaneous disease had anti-Dsg1 antibodies, while patients with deeper cutaneous lesions or with mucosal involvement had anti-Dsg3 reactivity also, or exclusively. The BP180-based assay was positive for 66.6% of patients with bullous pemphigoid and for none of the patients with mucous membrane pemphigoid, and no reactivity was detected in the control sera. In conclusion, the anti-Dsg1 and anti-Dsg3 assays are useful in the diagnosis of pemphigus and provide information on the clinical phenotype of the disease. However, the sensitivity of EIA for detection of autoantibodies in bullous pemphigoid should be improved by the use of additional antigens or epitopes.
HLA Class II Profile and Distribution of HLA-DRB1 and HLA-DQB1 Alleles and Haplotypes among Lebanese and Bahraini Arabs
Authors: Almawi Wassim Y. , Busson Marc , Tamim Hala , Al-Harbi Einas M. , Finan Ramzi R. , Wakim-Ghorayeb Saria F. , Motala Ayesha A.
Published: July 2004

The gene frequencies of HLA class II alleles were studied in 95 healthy Lebanese Arab and 72 healthy Bahraini Arab subjects. Our aim was to establish the genetic relationship between Bahraini and Lebanese Arabs in terms of HLA class II gene and haplotype frequencies and to compare these results with frequencies for other countries with populations of Caucasian and non-Caucasian descent. Subjects were unrelated and of both sexes, and HLA-DRB1 and -DQB1 genotyping was done by the PCR sequence-specific primer technique. Comparative analysis of the HLA-DR and -DQ alleles revealed differences in the allelic distribution among Bahraini and Lebanese subjects. Analysis of the 25 HLA-DRB1 alleles that have been investigated showed that the DRB1*040101 and DRB1*110101 alleles were more frequent among Lebanese, whereas DRB1*030101 and DRB1*160101 alleles were more frequent among Bahrainis. Similarly, of the seven HLA-DQB1 alleles analyzed, the presence of DQB1*0201 was more frequent among Bahrainis, whereas DQB1*030101 was more frequent among Lebanese. The DRB1*160101-DQB1*050101 (0.1318 versus 0.0379%) and DRB1*030101-DQB1*0201 (0.1202 versus 0.0321%) haplotypes were more frequent among Bahrainis, while the DRB1*110101-DQB1*030101 (0.3142 versus 0.1198%) and DRB1*040101-DQB1*0302 (0.1416 versus 0.0278%) haplotypes were more frequent in Lebanese subjects. Furthermore, a high prevalence of the DRB1*040101-DRB1*110101-DQB1*0302-DQB1*030101 (12.63 versus 1.35%,
P
= 0.015) and the homozygous DRB1*110101-DRB1*110101-DQB1*030101-DQB1*030101 (7.37 versus 0.00%,
P
= 0.046) genotypes was seen among Lebanese, and DRB1*070101-DRB1*160101-DQB1*0201-DQB1*050101 (6.76 versus 0.00%,
P
= 0.034) was seen more frequently among Bahraini subjects. Our results underline significant differences between these two populations in HLA class II distribution, provide basic information for further studies of major histocompatibility complex heterogeneity among Arabic-speaking countries, and serve as a reference for further anthropological studies.
Use of a Novel Enzyme Immunoassay Based on Detection of Circulating Antigen in Serum for Diagnosis ofHelicobacter pyloriInfection
Authors: Attallah Abdelfattah M. , Ismail Hisham , Ibrahim Gellan G. , Abdel-Raouf Mohamed , El-Waseef Ahmed M. , Abdel-Wahab Mohamed
Published: July 2004

Recently, noninvasive diagnostic tests forHelicobacter pyloriinfection have gained in significance. We have developed a sensitive and specific noninvasive immunoassay based on the detection of anH. pyloricirculating antigen (HpCA) in sera fromH. pylori-infected individuals. Monospecific antibody and Western blot analyses were used to demonstrate the presence of the target antigen inH. pyloricell lysate and serum samples. A novel enzyme-linked immunosorbent assay (ELISA) was developed for the detection of HpCA in serum. Endoscopic biopsy specimens from the gastric antra of 221 individuals (143 males and 78 females) with dyspeptic symptoms were evaluated forH. pyloriinfection, with culture used as a “gold standard” for diagnosis. The targetH. pyloriantigen was identified at 58 kDa. HpCA has been detected by ELISA with high degrees of sensitivity, specificity, and efficiency (>90%), and ELISA results show no significant difference (P> 0.05) from results ofH. pyloriculture of gastric biopsy specimens. The test's positive and negative predictive values were also high (95 and 86%, respectively). In conclusion, a sensitive and specific immunoassay was developed for the detection of HpCA in human serum. This test can be applied for noninvasive laboratory and field diagnoses ofH. pyloriinfection.
Effect of Pregnancy and Human Immunodeficiency Virus Infection on Intracellular Interleukin-2 Production Patterns
Authors: Sutton Madeline Y. , Holland Bart , Denny Thomas N. , Garcia Ambrosia , Garcia Zenaida , Stein Dana , Bardeguez Arlene D.
Published: July 2004

Human immunodeficiency virus type 1 (HIV-1) infection decreases the production of interleukin-2 (IL-2) from CD4
+
and CD8
+
T cells. Recombinant IL-2 (rIl-2) has been given to HIV-infected individuals to generate significant increases in CD4
+
T-cell counts. There are limited data regarding the effects of pregnancy and HIV infection on IL-2 production in humans. To investigate the effects of human pregnancy, HIV infection, and HIV therapy on IL-2 production, we evaluated 61 women. Intracellular IL-2 production by CD4
+
T cells from nonpregnant HIV-infected women was significantly lower than in that in uninfected women (45% ± 8% versus 52% ± 8%,
P
= 0.04). In contrast, there was no difference in levels of intracellular IL-2 production between HIV-infected and uninfected pregnant women. These observations suggest that pregnancy may down-regulate IL-2 production regardless of HIV infection status. Future studies should evaluate IL-2 production patterns in larger cohorts of women so that the physiological significance of IL-2 down-regulation in pregnancy can be further evaluated. This information is essential to assess the possible use of IL-2 supplementation therapy as a means of enhancing immune responses among HIV-infected pregnant women.
Molecular Characterization of Extended-Spectrum Beta-Lactamases Produced by Clinical Isolates of
Klebsiella pneumoniae
and
Escherichia coli
from a Korean Nationwide Survey
Authors: Jeong Seok Hoon , Bae Il Kwon , Lee Jung Hun , Sohn Seung Ghyu , Kang Geun Ho , Jeon Ghil Ja , Kim Young Ho , Jeong Byeong Chul , Lee Sang Hee
Published: July 2004

To determine the prevalence and genotypes of extended-spectrum beta-lactamases (ESBLs) among clinical isolates of
Klebsiella pneumoniae
and
Escherichia coli
, we performed antibiotic susceptibility testing, pI determination, induction testing, transconjugation, and DNA sequencing analysis. Among the 509 isolates collected from 13 university hospitals in Korea, 39.2% produced ESBLs. ESBL-producing isolates were detected in every region in Korea. A total of 44.6% of the isolates produced both TEM- and SHV-type ESBLs, and 52% of ESBL-producing isolates transferred resistance to ceftazidime by transconjugation. The ESBLs were TEM-19, TEM-20, TEM-52, SHV-2a, SHV-12, and one new variant identified for the first time in Korea, namely, TEM-116. TEM-1 and SHV-12 were by far the most common variants. TEM-1, TEM-116, and SHV-12 showed a high prevalence in
K. pneumoniae
. Two isolates (
E. coli
SH16 and
K. pneumoniae
SV3) produced CMY-1-like beta-lactamases, which play a decisive role in resistance to cefoxitin and cefotetan, as well as TEM-type enzymes (TEM-20 and TEM-52, respectively). Using MIC patterns and DNA sequencing analysis, we postulated a possible evolution scheme among TEM-type beta-lactamases in Korea: from TEM-1 to TEM-19, from TEM-19 to TEM-20, and from TEM-20 to TEM-52.
Measles Virus Genotyping by Nucleotide-Specific Multiplex PCR
Authors: Kremer Jacques R. , Fack Fred , Olinger Christophe M. , Mulders Mick N. , Muller Claude P.
Published: July 2004

A simple genotyping method based on multiplex PCR has been developed to discriminate between all active measles virus (MV) clades and genotypes (A, B3.1, B3.2, C2, D2-D9, G2-G3, and H1-H2). The sequencing reaction was replaced by six multiplex PCRs: one to identify the clade and five to identify the respective genotype. Primers were sensitive to clade- and genotype-specific nucleotides and generated fragments of type-specific sizes that were analyzed by conventional agarose gel electrophoresis. On the basis of all published MV sequences, positive and negative predictive values of 99.2% and 98.6% were calculated. Variability in the primer binding sites, which could potentially reduce sensitivity, was very limited among published sequences. As new genotypes are described, additional specific primers can be included in the multiplex PCR with relative ease. Although sequencing remains the “gold standard,” the present method should facilitate MV genotyping especially in developing countries and will therefore contribute to enhanced MV control and elimination strategies as recommended by the World Health Organization.
Simultaneous Runs of the Bayer VERSANT HIV-1 Version 3.0 and HCV bDNA Version 3.0 Quantitative Assays on the System 340 Platform Provide Reliable Quantitation and Improved Work Flow
Authors: Elbeik Tarek , Markowitz Norman , Nassos Patricia , Kumar Uday , Beringer Scott , Haller Barbara , Ng Valerie
Published: July 2004

Branched DNA (bDNA) assays to quantify human immunodeficiency virus type 1 (HIV-1) and hepatitis C virus (HCV) consist of three distinct steps, including sample processing, hybridization, and detection, and utilize the System 340 platform for plate incubation and washing. Sample processing differs: HIV-1 from 1 ml of plasma is concentrated by high-speed centrifugation, whereas HCV plasma or serum samples are used without concentration. The first step of hybridization involves viral lysis at 63°C: HIV-1 is performed in a heat block, whereas HCV is performed in System 340. The remaining hybridization and detection steps are similar for HIV-1 and HCV and executed on System 340. In the present study, the HIV-1 bDNA assay was adapted for viral lysis in the System 340 platform. The adaptation, test method 2, includes a 20-s vortex of concentrated viral pellet and lysis working solution, transfer of viral lysate to the 96-well capture plate, and transfer to System 340 programmed for HCV assay specifications. With test method 2, specificity and quantification were within assay specifications. HCV bDNA methodology remains unchanged. Hence, an HIV-1 and an HCV bDNA can be run simultaneously on System 340. With simultaneous testing, laboratories can run full plates, as well as combinations of full and partial plates. Also, simultaneous HIV-1 and HCV bDNA permits labor consolidation and improved workflow while maintaining multitasking and rapid patient result turnaround.
Immunohistostaining Assays for Detection of
Chlamydia pneumoniae
in Atherosclerotic Arteries Indicate Cross-Reactions with Nonchlamydial Plaque Constituents
Authors: Hoymans Vicky Y. , Bosmans Johan M. , Ursi Dominique , Martinet Wim , Wuyts Floris L. , Van Marck Eric , Altwegg Martin , Vrints Christiaan J. , Ieven Margareta M.
Published: July 2004

Detection of
Chlamydia pneumoniae
antigens in PCR-negative atheromata by immunohistochemistry assays has given rise to controversies regarding a link between the bacterium and atherosclerosis. One hundred ninety-seven human arterial segments removed surgically were examined for
C. pneumoniae
DNA by conventional PCR with three different primer pairs and by real-time PCR in two different laboratories. No
C. pneumoniae
DNA was detected. Eighty atherosclerotic lesions were studied by immunohistochemistry assays. Immunoreactivity for
C. pneumoniae
was frequently present but was not related to the extent of atherosclerosis. Mammary arteries showed immunoreactivity. Serial sections of 17 atheromata were analyzed by Western blotting, histological staining, and UV fluorescence microscopy. Chlamydial proteins were not detected. The sites with positive results by
C. pneumoniae
immunohistostaining assays precisely matched the sites with autofluorescent ceroid deposits. Immunoblotting and antigenic staining for
C. pneumoniae
were negative in tests with fetal aortas. The absence of
C. pneumoniae
DNA in human atherosclerotic lesions, together with negative results for
C. pneumoniae
proteins by Western blotting analysis, and the perfect matching of
C. pneumoniae
immunoreactive sites with sites with autofluorescent ceroid deposits suggest a nonspecific reactivity of antichlamydial antibodies with plaque constituents. On the basis of the results of the present study, there are no arguments for an etiologic role of
C. pneumoniae
in atherosclerosis.
Development and Clinical Evaluation of a Highly Sensitive DNA Microarray for Detection and Genotyping of Human Papillomaviruses
Authors: Oh Tae Jeong , Kim Chang Jin , Woo Suk Kyung , Kim Tae Seung , Jeong Dong Jun , Kim Myung Soon , Lee Sunwoo , Cho Hyun Sill , An Sungwhan
Published: July 2004

Human papillomavirus (HPV) has been found in cervical cancer, tonsillar cancer, and certain types of head and neck cancers. We report on a DNA microarray-based method for the simultaneous detection and typing of HPVs. The genotype spectrum discriminated by this HPV DNA microarray includes 15 high-risk HPV genotypes and 12 low-risk HPV genotypes. The HPV DNA microarray showed high degrees of specificity and reproducibility. We evaluated the performance of the HPV DNA microarray by application to three HPV-positive cell lines (HeLa, Caski, and SiHa cells) and two HPV-negative cell lines (C33A and A549 cells). The HPV DNA microarray successfully identified the known types of HPV present in the cell lines. The detection limit of the HPV DNA microarray was at least 100-fold higher than that of PCR. To assess the clinical applicability of the HPV DNA microarray, we performed the HPV genotyping assay with 73 nonmalignant and malignant samples from 39 tonsillar cancer patients. Twenty-five of the 39 (64.1%) malignant samples were positive for HPV, whereas 3 of 34 (8.8%) nonmalignant samples were positive for HPV. This result shows a preferential association of HPV with tonsillar carcinomas. The correlations of the presence of HPV with the grade of differentiation and risk factors were not significant. Our data show that the HPV DNA microarray may be useful for the diagnosis and typing of HPV in large-scale epidemiological studies.
Evaluation of a Real-Time PCR Assay Using the LightCycler System for Detection of Parvovirus B19 DNA
Authors: Buller Richard S. , Storch Gregory
Published: July 2004

We evaluated the artus RealArt Parvovirus B19 LC PCR reagent (artus biotech USA, San Francisco, Calif.) for real-time PCR detection of parvovirus B19 DNA by retesting 71 specimens previously submitted to our laboratory. The artus assay, which produces a quantitative result and provides an internal PCR control, appeared to be slightly more sensitive than our conventional qualitative PCR assay.
Epidemiological Investigation of Bloodstream Infections by Extended Spectrum Cephalosporin-ResistantEscherichia coliin a Taiwanese Teaching Hospital
Authors: Yan Jing-Jou , Ko Wen-Chien , Wu Jiunn-Jong , Tsai Shu-Huei , Chuang Chin-Luan
Published: July 2004

In an epidemiologic and case-control study including 30 case patients over a 3.5-year period in a Taiwanese university hospital, only β-lactamase inhibitor use and extended-spectrum cephalosporin use were identified as independent risk factors for nosocomial CMY-2-producingEscherichia colibloodstream infection, and CMY-2 producers were found more prevalent than extended-spectrum β-lactamase-producing isolates.
Fungemia Caused by
Zygoascus hellenicus
in an Allogeneic Stem Cell Transplant Recipient
Authors: Brandt Mary E. , Kauffman Carol A. , Pappas Peter G. , Iqbal Naureen , Arthington-Skaggs Beth A. , Lee-Yang Wendy , Smith Maudy T.
Published: July 2004

Zygoascus hellenicus
(
Candida hellenica
) was isolated from a blood culture from a patient who had received an allogeneic stem cell transplant. The isolate displayed an antifungal susceptibility pattern of decreased susceptibility to fluconazole and itraconazole, high susceptibility to voriconazole, and low susceptibility to caspofungin. The organism was misidentified by a commercial yeast identification system. This is the first reported case of human infection with this rare ascomycetous yeast.
NOVEL ROOM TEMPERATURE ELECTROCHEMICAL DEPOSITION OF HIGH TEMPERATURE SUPERCONDUCTING FILMS
Authors: PAWAR S. H. , SHIRAGE P. M. , SHIVAGAN D. D. , JADHAV A. B.
Published: July 2004

The present review reports the innovative attempts made in the synthesis of a variety of high T c superconductor families in the form of thin films by electrochemical techniques. Summarizing the brief background of electrochemical deposition process, the growth mechanism of high T c superconducting films has been explained. The successful stories of room temperature electrochemical deposition of RE - Ba 2 Cu 3 O 7-δ, Bi – Sr – Ca – CuO , Tl – Ba – Ca – CuO , Hg – Ba – Ca – CuO and MgB2 superconductors in the form of thin films on silver substrates have been summarized. The room temperature electrochemical synthesis technique has helped to form a low-dimensional structure at the interface of Al/Tl-2223 hetero structure, which leads to a pathway for high T c and J c . The photoinduced effects of a variety of heterostructures formed with HTSC systems and CdSe semiconductor are also described.
PSEUDOPOTENTIAL IN THE STUDY OF SUPERCONDUCTING STATE PARAMETERS OF METALLIC GLASSES
Authors: GAJJAR P. N. , VORA A. M. , JANI A. R.
Published: July 2004

A recently proposed model potential is used to study the superconducting state parameters viz. electron-phonon coupling strength λ, Coulomb pseudopotential μ*, transition temperature TC, isotope effect exponent α and effective interaction strength NOV of 40 metallic glasses of simple, non-simple as well as transition metals. The advanced screening function due to Sarkar et al. has been employed to include the exchange and correlation effects. Instead of Vegard's law, the use of pseudo-alloy-atom model in the investigation of superconducting state properties of metallic glasses is proposed and found successfully.
dx2-y2-STATE OF HIGH TEMPERATURE SUPERCONDUCTORS WITH A SMALL ADMIXTURE OF dxy-STATE
Authors: LEE C. Y.
Published: July 2004

It is well known that most of the high temperature superconductors (at least hole-type) are in d-wave state. But it is still an unsolved problem whether it is a pure d-wave state or one has some kind of mixed state. Among the candidates for an admixture, there are s- and d-wave states. Existing experiments could not resolve this issue. New possibilities for experimental resolution of this problem are opened via recent observation of the collective modes in UBe 13 (heavy fermion superconductor) by microwave impedance technique experiments and in Sr 2 RuO 4 (high temperature superconductor) by ultrasound attenuation experiments.

Some theoretical treatments show that the most likely state is a mixture of two d-wave states: dx2-y2 and dxy with a small admixture of former state. To create the theoretical basis for investigation of possible mixed superconducting state in unconventional superconductors by sound attenuation and microwave absorption experiments, I derive for the first time a full set of equations for collective modes spectrum in dx2-y2-state with small admixture of dxy state. These equations allow to calculate the whole collective mode spectrum in mixed dx2-y2+iεdxy state and distinguish this state from pure d-wave states (whose collective mode spectrum has been calculated earlier) by ultrasound attenuation and microwave absorption experiments.
INTERACTING FAMILIES OF CALOGERO-TYPE PARTICLES AND SU(1,1) ALGEBRA
Authors: MELJANAC S. , MILEKOVIĆ M. , SAMSAROV A. , STOJIĆ M.
Published: July 2004

We study a one-dimensional model with F interacting families of Calogero-type particles. The model includes harmonic, two-body and three-body interactions. We emphasize the universal SU (1,1) structure of the model. We show how SU (1,1) generators for the whole system are composed of SU (1,1) generators of arbitrary subsystems. We find the exact eigenenergies corresponding to a class of the exact eigenstates of the F-family model. By imposing the conditions for the absence of the three-body interaction, we find certain relations between the coupling constants. Finally, we establish some relations of equivalence between two systems containing F families of Calogero-type particles.
EFFICIENT APPROXIMATION ALGORITHMS FOR PAIRWISE DATA CLUSTERING AND APPLICATIONS
Authors: WU XIAODONG , CHEN DANNY Z. , MASON JAMES J. , SCHMID STEVEN R.
Published: July 2004

Data clustering is an important theoretical topic and a sharp tool for various applications. It is a task frequently arising in geometric computing. The main objective of data clustering is to partition a given data set into clusters such that the data items within the same cluster are "more" similar to each other with respect to certain measures. In this paper, we study the pairwise data clustering problem with pairwise similarity/dissimilarity measures that need not satisfy the triangle inequality. By using a criterion, called the minimum normalized cut, we model the general pairwise data clustering problem as a graph partition problem. The graph partition problem based on minimizing the normalized cut is known to be NP-hard. For an undirected weighted graph of n vertices, we present a ((4+o(1)) In n)-approximation polynomial time algorithm for the minimum normalized cut problem; this is the first provably good approximation polynomial time algorithm for the problem. We also give a more efficient algorithm for this problem by sacrificing the approximation ratio slightly. Further, our scheme achieves a ((2+o(1)) In n)-approximation polynomial time algorithm for computing the sparsest cuts in edge-weighted and vertex-weighted undirected graphs, improving the previously best known approximation ratio by a constant factor. Some applications and implementation work of our approximation normalized cut algorithms are also discussed.
COVERING A SET OF POINTS WITH A MINIMUM NUMBER OF TURNS
Authors: COLLINS MICHAEL J.
Published: July 2004

Given a finite set of points in Euclidean space, we can ask what is the minimum number of times a piecewise-linear path must change direction in order to pass through all of them. We prove some new upper and lower bounds for the rectilinear version of this problem in which all motion is orthogonal to the coordinate axes. We also consider the more general case of arbitrary directions.
AXIAL WAVE IN LONG-RANGE PROPAGATION IN A RANGE-INDEPENDENT OCEAN
Authors: GRIGORIEVA NATALIE S. , FRIDMAN GREGORY M.
Published: July 2004

In many long-range propagation experiments the source and receiver are placed close to the depth of the waveguide (SOFAR) axis to minimize the interaction of the acoustic field with the ocean's surface and bottom. The time-of-arrival patterns of these experiments consist of resolvable, geometrical-like arrivals followed by an axial crescendo of unresolved energy. It is impossible to explain this late-arriving energy using the geometrical acoustics because of the presence of cusp caustics repeatedly along the waveguide axis. The interference of the wave fields corresponding to the rays located in the vicinity of the caustics near the waveguide axis produces a special "axial wave" that propagates along this axis. The purpose of the paper is to obtain the integral representation of the axial wave for an arbitrary deep-water waveguide in a range-independent medium in long-range acoustic propagation in the ocean when the source and receiver are located close to the depth of the sound-channel axis. The integral representation for the axial wave is derived with the use of solutions of the Helmholtz equation concentrated near the sound-channel axis and which decrease exponentially outside a strip containing the axis. These solutions have the form of the exponentials multiplied by parabolic cylinder functions whose arguments are sections of series in powers of ω-1/2, where ω is a cyclic frequency. Numerical results are obtained for the Munk canonical sound-speed profile.
ASYMPTOTIC APPROXIMATION OF OCEAN-ACOUSTIC PULSE PROPAGATION IN THE TIME DOMAIN
Authors: MAKRAKIS G. N. , SKARSOULIS E. K.
Published: July 2004

Broadband and narrowband time-domain asymptotics are proposed for pulse propagation in range-independent ocean environments. The broadband approximation results by applying the stationary-phase method to the Fourier transform of the Green's function, expressed in terms of normal modes. The narrowband approximation is obtained by incorporating the shape function of the emitted signal — assumed Gaussian — into the phase term and applying the steepest-descent method. The roots of the frequency-derivative of the phase are located in the complex plane by using a second-order expansion of the eigenvalues. The performance of the two approximations is studied numerically. While the broadband approximation improves with increasing bandwidth, the narrowband approximation improves when the bandwidth decreases. Both approximations improve with increasing range, and they can be used for delivering time-domain results more efficiently than with standard Fourier synthesis.
FINITE DIFFERENCE METHODS FOR ELASTIC WAVE PROPAGATION IN LAYERED MEDIA
Authors: TADI M.
Published: July 2004

This paper is concerned with the numerical modeling of elastic wave propagation in layered media. It considers two isotropic homogeneous elastic solids in perfect contact. The interface is parallel to the free surface. Two finite difference methods are developed. The usefulness of the methods are investigated for long time simulations and the accuracy of the results are compared with the response from an approximate model.
Inhibition of cell cycle progression and migration of vascular smooth muscle cells by prostaglandin D2 synthase: resistance in diabetic Goto-Kakizaki rats
Authors: Ragolia Louis , Palaia Thomas , Koutrouby Tara B. , Maesaka John K.
Published: July 2004

The regulation of vascular smooth muscle cell (VSMC) proliferation, migration, and apoptosis plays a clear role in the atherosclerotic process. Recently, we reported on the inhibition of the exaggerated growth phenotype of VSMCs isolated from hypertensive rats by lipocalin-type prostaglandin D2 synthase (L-PGDS). In the present study, we report the differential effects of L-PGDS on VSMC cell cycle progression, migration, and apoptosis in wild-type VSMCs vs. those from a type 2 diabetic model. In wild-type VSMCs, exogenously added L-PGDS delayed serum-induced cell cycle progression from the G1 to S phase, as determined by gene array analysis and the decreased protein expressions of cyclin-dependent kinase-2, p21Cip1, and cyclin D1. Cyclin D3 protein expression was unaffected by L-PGDS, although its gene expression was stimulated by L-PGDS in wild-type cells. In addition, platelet-derived growth factor-induced VSMC migration was inhibited by L-PGDS in wild-type cells. Type 2 diabetic VSMCs, however, were resistant to the L-PGDS effects on cell cycle progression and migration. L-PGDS did suppress the hyperproliferation of diabetic cells, albeit through a different mechanism, presumably involving the 2.5-fold increase in apoptosis and the concomitant 10-fold increase of L-PGDS uptake we observed in these cells. We propose that in wild-type VSMCs, L-PGDS retards cell cycle progression and migration, precluding hyperplasia of the tunica media, and that diabetic cells appear resistant to the inhibitory effects of L-PGDS, which consequently may help explain the increased atherosclerosis observed in diabetes.
Enteroendocrine cells and 5-HT availability are altered in mucosa of guinea pigs with TNBS ileitis
Authors: O'Hara Jennifer R. , Ho Winnie , Linden David R. , Mawe Gary M. , Sharkey Keith A.
Published: July 2004

Enteroendocrine cells act as sensory transducers, releasing 5-HT and numerous peptides that are involved in regulating motility, secretion, and gut sensation. The action of mucosal 5-HT is terminated by a 5-HT reuptake transporter (SERT). In this study, we examined the hypothesis that ileitis leads to changes in enteroendocrine cell populations and mucosal 5-HT availability. Ileitis was induced in guinea pigs by intraluminal injection of 2,4,6-trinitrobenzenesulfonic acid and experiments were conducted 3, 7, and 14 days after treatment. The number of somatostatin, neurotensin, and 5-HT-immunoreactive cells increased at 3 and 7 days of ileitis, respectively, whereas no significant changes in the numbers of cholecystokinin, glucagon-like peptide-2, glucose-dependent insulinotropic peptide, and peptide YY-immunoreactive cells were observed. Chemical stimulation of the inflamed mucosa with sodium deoxycholic acid significantly increased 5-HT release compared with basal release. Mechanical stimulation of the mucosa potentiated the effect of the chemical stimuli at day 7. Epithelial SERT immunoreactivity was significantly reduced during the time course of inflammation. Thus changes in enteroendocrine cell populations and 5-HT availability could contribute to the altered motility and secretion associated with intestinal inflammation by disrupting mucosal signaling to enteric nerves involved in peristaltic and secretory reflexes.
Acid increases proliferation via ERK and p38 MAPK-mediated increases in cyclooxygenase-2 in Barrett's adenocarcinoma cells
Authors: Souza Rhonda F. , Shewmake Kenneth , Pearson Stephanie , Sarosi George A. , Feagins Linda A. , Ramirez Ruben D. , Terada Lance S. , Spechler Stuart J.
Published: July 2004

Cyclooxygenase-2 (COX-2) has been linked to neoplastic progression in Barrett's esophagus. Acid exposure has been shown both to activate the MAPK pathways and to increase COX-2 protein expression in Barrett's metaplasia, but it is not known whether these effects are interrelated. We hypothesized that acid-induced activation of the MAPK pathways mediates an increase in COX-2 expression in Barrett's esophagus, and we tested this hypothesis in a Barrett's-associated adenocarcinoma cell line (SEG-1). We exposed SEG-1 cells to acidic or neutral media in the presence and absence of two MAPK inhibitors: U-0126 (an ERK inhibitor) or SB-203580 (a p38 inhibitor). We quantitated COX-2 protein levels using an enzyme immunometric assay and COX-2 mRNA levels using real-time PCR. We also determined how acid affects the activity of the COX-2 promoter and mRNA stability. Compared with SEG-1 cells exposed to neutral media, acid-exposed cells exhibited a 2.8-fold increase in COX-2 mRNA levels within 30 min. Both U-0126 and SB-203580 attenuated the acid-induced increase in COX-2 mRNA. Acid significantly increased COX-2 protein expression and promoter activity, and both of these effects were abolished by treatment with U-0126 and SB-203580. Acid exposure also stabilized COX-2 mRNA levels, an effect that was abolished by U-0126 but not by SB-203580. We conclude that acid increases COX-2 expression through activation of the MAPK pathways. Acid-induced activation of both ERK and p38 causes a significant increase in COX-2 promoter activity, and acid-activated ERK stabilizes COX-2 mRNA. These findings suggest potential mechanisms whereby acid reflux might promote carcinogenesis in Barrett's esophagus.
Green tea polyphenol (−)-epigallocatechin gallate blocks epithelial barrier dysfunction provoked by IFN-γ but not by IL-4
Authors: Watson James L. , Ansari Sara , Cameron Heather , Wang Arthur , Akhtar Mahmood , McKay Derek M.
Published: July 2004

A characteristic of many enteropathies is increased epithelial permeability, a potentially pathophysiological event that can be evoked by T helper (Th)-1 (i.e., IFN-γ) and Th2 (i.e., IL-4) cytokines and bacterial infection [e.g., enteropathogenic Escherichia coli (EPEC)]. The green tea polyphenol (−)-epigallocatechin gallate (EGCG) has immunosuppressive properties, and we hypothesized that it would ameliorate the increased epithelial permeability induced by IFN-γ, IL-4, and/or EPEC. EGCG, but not the related epigallocatechin, completely prevented the increase in epithelial (i.e., T84 cell monolayer) permeability caused by IFN-γ exposure as gauged by transepithelial resistance and horseradish peroxidase flux; EGCG did not alleviate the barrier disruption induced by IL-4 or EPEC. IFN-γ-treated T84 and THP-1 (monocytic cell line) cells displayed STAT1 activation (tyrosine phosphorylation on Western blot analysis, DNA binding on EMSA) and upregulation of interferon response factor-1 mRNA, a STAT1-dependent gene. All three events were inhibited by EGCG pretreatment. Aurintricarboxylic acid also blocked IFN-γ-induced STAT1 activation, but it did not prevent the increase in epithelial permeability. Additionally, pharmacological blockade of MAPK signaling did not affect IFN-γ-induced epithelial barrier dysfunction. Thus, as a potential adjunct anti-inflammatory agent, EGCG can block STAT1-dependent events in gut epithelia and monocytes and prevent IFN-γ-induced increased epithelial permeability. The latter event is both a STAT1- and MAPK-independent event.
Endothelin-1 mediates cardiac mast cell degranulation, matrix metalloproteinase activation, and myocardial remodeling in rats
Authors: Murray David B. , Gardner Jason D. , Brower Gregory L. , Janicki Joseph S.
Published: July 2004

The objective of this study was to determine whether elevated circulating levels of endothelin (ET)-1 are capable of mediating left ventricular (LV) mast cell degranulation and thereby induce matrix metalloproteinase (MMP) activation. After the administration of 20 pg/ml ET-1 to blood-perfused isolated rat hearts, LV tissue was analyzed for signs of mast cell degranulation and MMP activation. Relative to control, ET-1 produced extensive mast cell degranulation as well as a significant increase in myocardial water content (78.8 ± 1.5% vs. 74.2 ± 2.2%, P < 0.01), a marked 107% increase in MMP-2 activity ( P < 0.05), and a substantial decrease in collagen volume fraction (0.69 ± 0.09% vs. 0.99 ± 0.04%, P < 0.001). Although the myocardial edema would be expected to increase ventricular stiffness, compliance was not altered, and moderate ventricular dilatation was observed (end-diastolic volume at end-diastolic pressure of 0 mmHg of 330.2 ± 22.1 vs. 298.9 ± 17.4 μl in ET-1 treated vs. control, respectively, P = 0.07). Additionally, pretreatment with the mast cell stabilizer nedocromil prevented ET-1-induced changes in MMP-2 activity, myocardial water content, collagen volume fraction, and end-diastolic volume. These findings demonstrate that ET-1 is a potent cardiac mast cell secretogogue and further indicate that ET-1-mediated mast cell degranulation is a potential mechanism responsible for myocardial remodeling.
Endothelial NOS is main mediator for shear stress-dependent angiogenesis in skeletal muscle after prazosin administration
Authors: Baum Oliver , Da Silva-Azevedo Luis , Willerding Gregor , Wöckel Achim , Planitzer Gerit , Gossrau Reinhart , Pries Axel R. , Zakrzewicz Andreas
Published: July 2004

The increase of wall shear stress in capillaries by oral administration of the α1-adrenergic receptor antagonist prazosin induces angiogenesis in skeletal muscles. Because endothelial nitric oxide synthase (eNOS) is upregulated in response to elevated wall shear stress, we investigated the relevance of eNOS for prazosin-induced angiogenesis in skeletal muscles. Prazosin and/or the NOS inhibitor Nω-nitro-l-arginine methyl ester (l-NAME) were given to C57BL/6 wild-type mice and eNOS-knockout mice for 14 days. The capillary-to-fiber (C/F) ratio and capillary density (CD; no. of capillaries/mm2) were determined in frozen sections from extensor digitorum longus (EDL) muscles of these mice. Immunoblotting was performed to quantify eNOS expression in endothelial cells isolated from skeletal muscles, whereas VEGF (after precipitation with heparin-agarose) and neuronal NOS (nNOS) concentrations were determined in EDL solubilizates. In EDL muscles of C57BL/6 mice treated for 14 days, the C/F ratio was 28% higher after prazosin administration and 11% higher after prazosin and l-NAME feeding, whereas the CD increased by 21 and 13%, respectively. The C/F ratio was highest after day 4 of prazosin treatment and decreased gradually to almost constant values after day 8. Prazosin administration led to elevation of eNOS expression. VEGF levels were lowest at day 4, whereas nNOS values decreased after day 8. In EDL muscles of eNOS-knockout mice, no significant changes in C/F ratio, CD, or VEGF and nNOS expression were observed in response to prazosin administration. Our data suggest that the presence of eNOS is essential for prazosin-induced angiogenesis in skeletal muscle, albeit other signaling molecules might partially compensate for or contribute to this angiogenic activity. Furthermore, subsequent remodeling of the capillary system accompanied by sequential downregulation of VEGF and nNOS in skeletal muscle fibers characterizes shear stress-dependent angiogenesis.
Tagged MRI and PET in severe CAD: discrepancy between preoperative inotropic reserve and intramyocardial functional outcome after revascularization
Authors: Mazzadi Alejandro N. , Janier Marc F. , Brossier Benjamin , André-Fouët Xavier , Revel Didier , Croisille Pierre
Published: July 2004

In severe coronary artery disease (CAD), it has been shown that intramyocardial inotropic reserve as assessed with tagged magnetic resonance imaging (MRI) is uniformly distributed among positron emission tomography (PET) patterns reflecting normal or concomitant reductions in perfusion and glucose metabolism. This preliminary study aimed to delineate the relationship between preoperative values of intramyocardial inotropic reserve (in different PET patterns of perfusion and glucose uptake) and intramyocardial functional outcome after surgical revascularization in severe CAD. Twelve patients underwent preoperative tagged MRI (baseline, 10 μg·kg−1·min−1 of dobutamine), H215O/[18F]fluorodeoxyglucose PET imaging, and postoperative resting tagged MRI. Regional midmyocardial circumferential shortening ( Ecc, in %) and PET patterns (normal, match viable, mismatch viable, and infarcted) were assessed in three tagged MRI/PET short-axis slices. Ecc at baseline ranged from 12 ± 6 to 8 ± 5 and 4 ± 4% in normal, match-viable, and infarcted regions, respectively ( P < 0.05) and was 8 ± 5% in mismatch-viable regions. Of the 429 regions studied, 187 showed preoperative inotropic reserve with dobutamine, but 238 showed postoperative functional improvement. Postoperative functional improvement was less common in infarcted regions (41 vs. ∼60% in the other PET patterns), but the extent of improvement was similar among PET patterns (∼6%). Postoperative functional improvement occurred in 53% of all (normal, match viable, and mismatch viable) regions without inotropic reserve. In severe CAD, revascularization affords greater intramyocardial functional benefit than expected from the evaluation of intramyocardial inotropic reserve with low-dose dobutamine. Postoperative functional improvement in PET-viable regions without inotropic reserve suggests that factors other than regionally enhanced perfusion contribute to such functional improvement.
Gene deletion of dopamine β-hydroxylase and α1-adrenoceptors demonstrates involvement of catecholamines in vascular remodeling
Authors: Zhang Hua , Cotecchia Susanna , Thomas Steven A. , Tanoue Akito , Tsujimoto Gozoh , Faber James E.
Published: July 2004

In vitro studies have shown that stimulation of α1-adrenoceptors (ARs) directly induces proliferation, hypertrophy, and migration of arterial smooth muscle cells and adventitial fibroblasts. In vivo studies confirmed these findings and showed that catecholamine trophic activity becomes excessive after experimental balloon injury and contributes to neointimal growth, adventitial thickening, and lumen loss. However, past studies have been limited by selectivity of pharmacological agents. The aim of this study, in which mice devoid of norepinephrine and epinephrine synthesis [dopamine β-hydroxylase (DBH−/−)] or deficient in α1-AR subtypes expressed in murine carotid (α1B-AR−/− and α1D-AR−/−) were used, was to test the hypothesis that catecholamines contribute to wall hypertrophy after injury. At 3 wk after injury of wild-type mice, lumen area and carotid circumference increased significantly, and hypertrophy of media and adventitia was in excess of that needed to restore circumferential wall stress to normal. In DBH−/− and α1B-AR−/− mice, increases in lumen area, circumference, and hypertrophy of the media and adventitia were reduced by 50–91%, resulting in restoration of wall tension to nearly normal (DBH−/−) or normal (α1B-AR−/−). In contrast, in α1D-AR−/− mice, increases in lumen area, circumference, and wall hypertrophy were unaffected and wall thickening remained in excess of that required to return tension to normal. When examined 5 days after injury, proliferation and leukocyte infiltration were inhibited in DBH−/− mice. These studies suggest that the trophic effects of catecholamines are mediated primarily by α1B-ARs in mouse carotid and contribute to hypertrophic growth after vascular injury.