bluuebunny/crossref_metadata_2025 huggingface dataset:
INNOVATIONS INTEACHINGPLANTPATHOLOGY
Authors: Schumann G.L.
Published: May 2003

▪ Abstract  The teaching environment for plant pathology is changing in both positive and negative ways. Teaching expectations are increasing and resources are decreasing, but recent educational research and instructional technology offer new approaches to meet these challenges. Plant pathologists are teaching courses that may attract new students to the discipline or at least improve agricultural awareness. The Internet offers rapid access to information and images for both students and instructors. Instructional technology provides new tools for classroom presentations, communication with students, reaching new audiences, and distance learning, but using these new tools to enhance learning requires skilled and creative instructors. In the past, many plant pathology instructors worked in relative isolation, but new communication technologies and publishing opportunities for teaching scholarship should improve the sharing of instructional resources and methods.
EVOLUTION OF WHEAT STREAK MOSAIC VIRUS: Dynamics of Population Growth Within Plants May Explain Limited Variation
Authors: French Roy , Stenger Drake C.
Published: May 2003

▪ Abstract  Like many other plant RNA viruses, Wheat streak mosaic virus (WSMV) sequence diversity within and among infected plants is low given the large number of virions produced. This may be explained by considering aspects of plant virus life history. Intracellular replication of RNA viruses is predominately linear, not exponential, which means that the rate at which mutations accumulate also is linear. Bottlenecks during systemic movement further limit diversity. Analysis of mixed infections with two WSMV isolates suggests that about four viral genomes participate in systemic invasion of each tiller. Low effective population size increases the role of stochastic processes on dynamics of plant virus population genetics and evolution. Despite low pair-wise diversity among isolates, the number of polymorphic sites within the U.S. population is about the same as between divergent strains or a sister species. Characteristics of polymorphism in the WSMV coat protein gene suggest that most variation appears neutral.
PATHOGEN SELF-DEFENSE: Mechanisms to Counteract Microbial Antagonism
Authors: Duffy Brion , Schouten Alexander , Raaijmakers Jos M.
Published: May 2003

▪ Abstract  Natural and agricultural ecosystems harbor a wide variety of microorganisms that play an integral role in plant health, crop productivity, and preservation of multiple ecosystem functions. Interactions within and among microbial communities are numerous and range from synergistic and mutualistic to antagonistic and parasitic. Antagonistic and parasitic interactions have been exploited in the area of biological control of plant pathogenic microorganisms. To date, biocontrol is typically viewed from the perspective of how antagonists affect pathogens. This review examines the other face of this interaction: how plant pathogens respond to antagonists and how this can affect the efficacy of biocontrol. Just as microbial antagonists utilize a diverse arsenal of mechanisms to dominate interactions with pathogens, pathogens have surprisingly diverse responses to counteract antagonism. These responses include detoxification, repression of biosynthetic genes involved in biocontrol, active efflux of antibiotics, and antibiotic resistance. Understanding pathogen self-defense mechanisms for coping with antagonist assault provides a novel approach to improving the durability of biologically based disease control strategies and has implications for the deployment of transgenes (microorganisms or plants).
PERSPECTIVES ONPLANT ANDSOILNEMATOLOGY
Authors: Barker Kenneth R.
Published: May 2003

▪ Abstract  During my career in Plant Pathology/Nematology, many major advancements have occurred in the study of nematodes—even with their being largely soilborne and thus often overlooked. These biotrophic organisms include the most widespread and important group of plant pathogens—the root-knot nematodes Meloidogyne species—which attack most major crops, as well as thousands of non-crop plant species. Landmark achievements that catalyzed research on these organisms included the discovery of effective nematicides, ectoparasitic forms, elucidation of disease complexes, nematodes as virus vectors, development of host resistance, and new technologies for research. Evolving research thrusts involve interfacing traditional and molecular systematics/diagnostics, adoption of the Caenorhabditis elegans-molecular genetics resource for general nematological research, focus on genetics of parasitism, use of molecular tools in developing host resistance, ecological and quantitative facets, and soil-biology-ecology based integrated management. Educational and international programs are encountering many changes and challenges, as is support for nematology in general.
QUORUM SENSING IN PLANT-PATHOGENIC BACTERIA
Authors: von Bodman Susanne B. , Bauer W. Dietz , Coplin David L.
Published: May 2003

▪ Abstract  Quorum sensing (QS) allows bacteria to assess their local population density and/or physical confinement via the secretion and detection of small, diffusible signal molecules. This review describes how phytopathogenic bacteria have incorporated QS mechanisms into complex regulatory cascades that control genes for pathogenicity and colonization of host surfaces. Traits regulated by QS include the production of extracellular polysaccharides, degradative enzymes, antibiotics, siderophores, and pigments, as well as Hrp protein secretion, Ti plasmid transfer, motility, biofilm formation, and epiphytic fitness. Since QS regulatory systems are often required for pathogenesis, interference with QS signaling may offer a means of controlling bacterial diseases of plants. Several bacterial pathogens of plants that have been intensively studied and have revealed information of both fundamental and practical importance are reviewed here: Agrobacterium tumefaciens, Pantoea stewartii, Erwinia carotovora, Ralstonia solanacearum, Pseudomonas syringae, Pseudomonas aeruginosa, and Xanthomonas campestris.
REGULATION OF ANTIBIOTIC PRODUCTION IN ROOT-COLONIZING PSEUDOMONAS SPP. AND RELEVANCE FOR BIOLOGICAL CONTROL OF PLANT DISEASE
Authors: Haas Dieter , Keel Christoph
Published: May 2003

▪ Abstract  Certain strains of fluorescent pseudomonads are important biological components of agricultural soils that are suppressive to diseases caused by pathogenic fungi on crop plants. The biocontrol abilities of such strains depend essentially on aggressive root colonization, induction of systemic resistance in the plant, and the production of diffusible or volatile antifungal antibiotics. Evidence that these compounds are produced in situ is based on their chemical extraction from the rhizosphere and on the expression of antibiotic biosynthetic genes in the producer strains colonizing plant roots. Well-characterized antibiotics with biocontrol properties include phenazines, 2,4-diacetylphloroglucinol, pyoluteorin, pyrrolnitrin, lipopeptides, and hydrogen cyanide. In vitro, optimal production of these compounds occurs at high cell densities and during conditions of restricted growth, involving (i) a number of transcriptional regulators, which are mostly pathway-specific, and (ii) the GacS/GacA two-component system, which globally exerts a positive effect on the production of extracellular metabolites at a posttranscriptional level. Small untranslated RNAs have important roles in the GacS/GacA signal transduction pathway. One challenge in future biocontrol research involves development of new strategies to overcome the broad toxicity and lack of antifungal specificity displayed by most biocontrol antibiotics studied so far.
ENGINEERINGPLANTS FORNEMATODERESISTANCE
Authors: Atkinson Howard J. , Urwin Peter E. , McPherson Michael J.
Published: May 2003

▪ Abstract  Biotechnology offers sustainable solutions to the problem of plant parasitic nematode control. There are several possible approaches for developing transgenic plants with improved nematode resistance; these include anti-invasion and migration strategies, feeding-cell attenuation, and antinematode feeding and development strategies. The essential elements of an effective control strategy are (a) genes that encode an antinematode effector protein, peptide or interfering RNA and (b) promoters that direct a specific pattern of expression for that effector. This review summarizes information on effectors that act directly against the nematode as well as those aimed at disrupting the nematode feeding site. We discuss patterns of promoter activity that could deliver expression of these effectors in a restricted and directed manner. Societal opposition to the technology of GM-nematode control is also discussed.
Averaging of multivalued differential equations
Authors: Grammel G.
Published: May 2003

Nonlinear multivalued differential equations with slow and fast
subsystems are considered. Under transitivity conditions on the
fast subsystem, the slow subsystem can be approximated by an
averaged multivalued differential equation. The approximation in
the Hausdorff sense is of order O(ϵ1/3) as ϵ → 0.
On Hill′s equation with a discontinuous coefficient
Authors: Karaca Ilkay Yaslan
Published: May 2003

We research the asymptotic formula for the lengths of the
instability intervals of the Hill′s equation with coefficients
q(x) and r(x), where q(x) is piecewise continuous and
r(x) has a piecewise continuous second derivative in open
intervals (0, b) and (b, a)(0 < b < a).
A relative integral basis over ℚ(−3) for the normal closure of a pure cubic field
Authors: Spearman Blair K. , Williams Kenneth S.
Published: May 2003

Let K be a pure cubic field. Let L be the normal closure of
K. A relative integral basis (RIB) for L over is given. This RIB simplifies and
completes the one given by Haghighi (1986).
Asymptotics of integrodifferential models with integrable kernels
Authors: Bijura Angelina M.
Published: May 2003

The additive decomposition singular perturbation method
and the theory of fractional integration are used to study
asymptotic solutions of singularly perturbed Volterra
integrodifferential equations with kernels having integrable
singularity. The validity of the approximation is also
demonstrated.
Circular Polya distributions of order k
Authors: Tripsiannis Gregory A. , Philippou Andreas N.
Published: May 2003

Two circular Polya distributions of order k are derived by
means of generalized urn models and by compounding, respectively,
the type I and type II circular binomial distributions of order
k of Makri and Philippou (1994) with the beta distribution. It
is noted that the above two distributions include, as special
cases, new circular hypergeometric, negative hypergeometric, and
discrete uniform distributions of the same order and type. The
means of the new distributions are obtained and two asymptotic
results are established relating them to the above‐mentioned
circular binomial distributions of order k.
On controllability, parametrization, and output tracking of alinearized bioreactor model
Authors: Tervo J. , Nihtilä M. T. , Kokkonen P.
Published: May 2003

The paper deals with a distributed parameter system related to the
so‐called fixed‐bed bioreactor. The original nonlinear partial differential system is linearized around the steady state. We find that the linearized system is not exactly controllable but it is approximatively controllable when certain
algebraic equations hold. We apply frequency‐domain methods (transfer function analysis) to consider a related output tracking problem. The input‐output system can be formulated as a translation invariant pseudodifferential equation. A simulation shows that the calculation scheme is stable. An idea to use
frequency‐domain methods and certain pseudodifferential operators
for parametrization of control systems of more general systems is
pointed out.
A note on the variational structure of an elliptic systeminvolving critical Sobolev exponent
Authors: Zuluaga Mario
Published: May 2003

We consider an elliptic system involving critical growth
conditions. We develop a technique of variational methods for
elliptic systems. Using the well‐known results of maximum
principle for systems developed by Fleckinger et al. (1995), we
can find positive solutions. Also, we generalize the systems
results obtained (for the scalar case) by Brézis and
Nirenberg (1983). Also, we give applications to biharmonic
equations.
The p1 Protein of the Yeast Transposon Ty1 Can Be Used for the Construction of Bi-Functional Virus-Like Particles
Authors: Marchenko A.N. , Kozlov D.G. , Svirshchevskaya E.V. , Viskova N.Y. , Benevolensky S.V.
Published: May 2003

Virus-like particles (VLPs) containing heterologous proteins are often used as vaccines. Two approaches for the construction of bi-functional VLPs using hybrid protein pl-380 of the Ty1 transposon of Saccharomyces yeast are described. We have shown that both C- and N-termini of p1–380 can be used for the expression of heterologous peptides. Peptides from A. fumigatus Asp f 2, expressed at the C- and/or N-termini of p1–380, did not interfere with VLP self-assembling, were accessible for antibodies and hence were exposed at the VLP surface. Another way to obtain bivalent VLPs is the formation of mixed particles, which co-express two hybrid pl proteins with different heterologous protein fragments at the C-terminus. To do it the yeast cells were transfected with a mixture of two recombinant DNA coding Asp f 2 peptide and green fluorescent protein (Gfp). We have shown that both Asp f 2 peptide and Gfp are expressed within the same particle. To evaluate biological activity of bi-functional VLP a construction containing peptides representing dominant T- and B-cell epitopes of Asp f 2 was produced. Bi-functional particles were more potent in stimulating memory immune responses. These results demonstrate new possibilities of pl-380 based expression system to produce multifunctional VLPs.
Validation Study of a CT-Based Weighted Rating Scale for Subcortical Ischemic Vascular Disease in Patients with Mild Cognitive Deterioration
Authors: Geroldi Cristina , Galluzzi Samantha , Testa Cristina , Zanetti Orazio , Frisoni Giovanni B.
Published: May 2003

Objectives: Subcortical ischemic vascular disease (SIVD) is frequently associated with cognitive impairment. Rating scales to grade cerebrovascular disease are available, but their sensitivity to the clinical features of mild SIVD is unclear. The aim of the study is to devise and validate a computed tomography (CT)-based visual rating scale sensitive to SIVD in patients with mild cognitive deterioration. Methods: Subjects were 122 consecutive outpatients of a memory clinic (mean age ± SD 77 ± 8 years, 71% females, mean ± SD score of mental state exam 22 ± 3, 61% with clinical dementia rating of 0.5 and 39% of 1). Diffuse leukoaraiosis, fuzzy and patchy lesions, and lacunes were assessed on ordinary CT films and weights were computed based on clinical indicators of SIVD. A continuous score and an ordinal class (0–3) with higher values indicating higher vascular damage were derived. Results: Intraclass correlation coefficients for intra- and interrater reliability of the subcortical vascular score and class ranged from 0.84 to 0.88. Convergent validity versus the scale of Wahlund et al. was good (Spearman’s correlation coefficient between 0.53 and 0.73, p < 0.0005). Known-group validity was assessed versus clinical diagnoses of degenerative (mild cognitive impairment determined by Petersen et al. and NINCDS-ADRDA probable Alzheimer’s disease; n = 58), mixed (possible Alzheimer’s disease with cerebrovascular disease; n = 21), and vascular cognitive impairment (criteria of Erkinjuntti et al. for subcortical vascular dementia and cognitive impairment; n = 43). Patients with degenerative cognitive impairment were more often in the lower subcortical vascular classes (43% in class 0, 43% in class 1, 14% in class 2, and 0% in class 3), while patients with mixed (0, 24, 24, and 52%) and vascular cognitive impairment were in increasingly higher subcortical vascular classes (0, 12, 35, 53%; p < 0.00005). Criterion-related validity was assessed versus clinical indicators of cerebrovascular disease. Hypertension, platelet aggregation inhibitor use, balance, gait, and bradykinesia increased linearly with increasing subcortical vascular class (p for trend <0.02). Conclusions: This rating scale is valid and sensitive to capture different degrees of SIVD associated with mild cognitive deterioration.
Glutathione S-Transferase Polymorphisms: Susceptibility to Migraine without Aura
Authors: Kusumi M. , Ishizaki K. , Kowa H. , Adachi Y. , Takeshima T. , Sakai F. , Nakashima K.
Published: May 2003

Migraine is considered to be a polygenic multifactorial disease with various environmental and genetic etiologies. We investigated glutathione S-transferase (GST) P1 Ile105Val, T1 and M1 polymorphisms in 174 Japanese headache sufferers and 372 Japanese controls. The headache group consisted of 38 cases of migraine with aura, 95 migraine without aura (MWOA) and 41 tension-type headache sufferers. The M1 homozygous deletion genotype was significantly higher in MWOA (64%) compared with controls (46%; p < 0.01; odds ratio = 2.18, 95% confidence interval: 1.32–3.61, adjusted for age and gender). In a comparison of the current smokers, the M1 null frequencies in MWOA were further increased. GSTM1 may be one of the genetic risk factors for MWOA in the Japanese population.
Clinical and Molecular Analysis of Chinese Patients with Thyrotoxic Periodic Paralysis
Authors: Chen L. , Lang D. , Ran X.W. , Joncourt F. , Gallati S. , Burgunder J.-M.
Published: May 2003

Although sporadic thyrotoxic periodic paralysis (TPP) has a much higher prevalence in Asian than in all the other populations studied so far, it is also increasingly being seen at the emergency departments of the West, hence, it is vital to stress the importance of recognizing it. TPP shares some similarities with hypokalemic periodic paralysis (HOKPP). However, the pathophysiology of TPP and the reasons for this higher incidence are not known. We hypothesized that some mutations in the CACNA1S gene, which has been implicated in familial HOKPP, might play a role in TPP. We present 5 Chinese patients who suffer from TPP and demonstrate typical clinical features. No mutation was found on the whole CACNA1S gene. Therefore other molecular mechanisms will have to be examined in order to explain the different TPP incidences.
Cloning and Characterisation of Two IgE-Binding Proteins, Homologous to Tropomyosin and α-Tubulin, from the Mite Lepidoglyphus destructor
Authors: Saarne Tiiu , Kaiser Liselotte , Rasool Omid , Huecas Sonia , van Hage-Hamsten Marianne , Gafvelin Guro
Published: May 2003

Background: The dust mite Lepidoglyphus destructor is a major source of mite allergy in European rural environments, but it also causes allergy in urban populations around the world. We have previously cloned, sequenced and expressed several allergens from L. destructor (Lep d 2, Lep d 5, Lep d 7 and Lep d 13). The aim of this study was to identify and clone additional allergens from L. destructor, and to evaluate their IgE-binding reactivities. Methods: PCR and screening with sera from L. destructor-sensitised individuals were used to isolate new clones from a phage display L. destructor cDNA library. The complete coding sequences of the clones were determined and expressed as His6-tagged recombinant proteins in Escherichia coli. The recombinant proteins were analysed by SDS-PAGE, immunoblotting and mass spectrometry. Results: Two new clones, showing homology to tropomyosin and α-tubulin in several species, were isolated from the phage display L. destructor cDNA library. Due to its homology to group 10 dust mite allergens, the tropomyosin clone was named Lep d 10. The IgE-binding frequencies of the recombinant Lep d 10 and α-tubulin were 13% (18/136) and 12% (11/95), respectively, among subjects with IgE reactivity to mites and/or crustaceans. Conclusions: Two new allergens from L. destructor have been identified and can now be added to the repertoire of recombinant L. destructor allergens. In addition, both these allergens belong to highly conserved protein families and may be important for evaluation of allergenic cross-reactivity.
Comparative Effects of Desloratadine versus Montelukast on Asthma Symptoms and Use of β2-Agonists in Patients with Seasonal Allergic Rhinitis and Asthma
Authors: Baena-Cagnani Carlos E. , Berger William E. , DuBuske Lawrence M. , Gurné Sandra E. , Stryszak Paul , Lorber Richard , Danzig Melvyn
Published: May 2003

Background: Asthma and seasonal allergic rhinitis (SAR) are recognized as manifestations of a single airway disease. Desloratadine has demonstrated efficacy in treating SAR symptoms, including nasal obstruction. Methods: Safety and efficacy of desloratadine and montelukast each were assessed in a double-blind, placebo-controlled trial of patients with SAR and symptoms of asthma, who were assigned randomly to once-daily treatment with desloratadine 5 mg, montelukast 10 mg, or placebo for 4 weeks. Change from baseline of AM/PM reflective total asthma symptom severity scores (TASS), FEV1, individual asthma symptom scores, and β2-agonist usage were assessed. Results: Desloratadine and montelukast each were associated with statistically significant reductions from baseline in the mean TASS averaged over the 4-week period (p ≤0.022 vs. placebo). Individual asthma symptom scores also improved significantly for both therapies (p ≤ 0.05). Patients treated with desloratadine or montelukast demonstrated improvement from baseline in FEV1 versus placebo; significant improvement was seen in a subset of patients with baseline FEV1 <80% of predicted normal (both p < 0.05). Both active therapies significantly reduced β2-agonist use (both p < 0.01). Improvements for both therapies were comparable for all efficacy parameters; they were tolerated well with adverse event profiles similar to placebo. Conclusions: Asthma symptoms and β2-agonist were improved significantly in patients with concomitant SAR and asthma treated with desloratadine 5 mg as well as montelukast 10 mg once daily. Both therapies significantly improved FEV1 in a subset of patients with FEV1 <80% of predicted normal at entry. Improvements in asthma symptoms were comparable for both active treatment groups.
Effect of a Calcium Carbonate-Based Dentifrice on Enamel Demineralization in situ
Authors: Cury J.A. , Francisco S.B. , Simões G.S. , Del Bel Cury A.A. , Tabchoury C.P.M.
Published: May 2003

Since the effect of calcium carbonate (CaCO3) based dentifrice on enamel demineralization is not clearly established, it was evaluated using the IEDT model described by Zero’s group in 1992. This study had a crossover design and 10 volunteers were submitted to 3 treatment groups: a negative control, brushing without dentifrice; an active control, brushing with silica-based dentifrice (SiO2/MFP group), and the experimental group, brushing with CaCO3-based dentifrice (CaCO3/MFP). Both dentifrices contained 1,500 µg F/g (w/w) as sodium monofluorophosphate (MFP). Enamel surface microhardness was determined in the dental blocks and the percentage change in relation to baseline was calculated. Fluoride uptake in enamel and its concentration in ‘test plaque’ were determined. The results showed that the dentifrice containing CaCO3/MFP was more effective than SiO2/MFP in reducing enamel demineralization (p < 0.05). A higher concentration of fluoride ion was found in ‘test plaque’ treated with CaCO3/MFP than in the negative control (p < 0.05). The results suggest that CaCO3 abrasive may enhance the effect of fluoride present in dentifrice on dental caries control.
Preliminary in vitro Assessment of Erosive Potential Using the Ultra-Micro-Indentation System
Authors: Mahoney Erin , Beattie James , Swain Michael , Kilpatrick Nicola
Published: May 2003

The aim of this study was to measure the change in hardness and modulus of elasticity of enamel and dentine in primary teeth using the ultra-micro-indentation system (UMIS) after exposure to potentially erosive beverages and to relate the changes to the chemical composition of the test beverages. Primary molar teeth were sectioned and polished. Indentations were made in enamel and dentine prior to and then after exposure to one of four beverages: distilled water (control), orange juice, Orange Cordial, Fanta® and a ‘toothfriendly’ Tropical Orange Cordial (Ribena®). Each beverage was then analysed. Fanta and Orange Cordial were the only test beverages to show a statistically significant reduction in the enamel hardness in comparison to the control and only Fanta showed a significant reduction in dentine hardness. None of the test beverages significantly reduced the modulus of elasticity of either enamel or dentine. Statistically the pH, phosphate and fluoride concentrations of the beverages were correlated with softening of enamel. Calcium concentration and titratable acidity were correlated with softening of dentine. The UMIS offers another method of measuring the basic mechanical properties of enamel and dentine. This is useful in predicting the erosive potential of substrates. It is likely that the pH, titratable acidity, fluoride, phosphate and calcium content of beverages are all important in determining the potential erosiveness of beverages.
Protective Influence of Experimentally Formed Salivary Pellicle on Enamel Erosion
Authors: Nekrashevych Yuriy , Stösser Lutz
Published: May 2003

The purpose of this study was to evaluate dental erosion in 0.1 and 1.0% citric acid in vitro by several different methods and to assess the protective potential of experimentally formed salivary pellicle (24 h in vitro). Bovine enamel slabs were embedded in epoxy resin and polished. Erosion was performed in citric acid for 1, 5 or 10 min and recorded as microhardness loss, as changes of surface roughness (Ra, Rt and RzDIN) and as calcium release. Additionally, erosive alterations were observed with scanning electron microscopy. Significant microhardness loss on non-pellicle-covered specimens was measured after 1-min exposure to 0.1% citric acid. Microhardness loss was time- and concentration-dependent. Salivary pellicle significantly inhibited both microhardness loss, except after 10-min immersion in 1.0% citric acid, and significantly reduced the increase of surface roughness. There were, however, no significant differences in calcium release between pellicle-covered and non-covered enamel. The results support the general conclusion that salivary pellicle effectively protects enamel surface against short-term erosion in organic acids.
Development of a Genotype 325–Specific proCPU/TAFI ELISA
Authors: Gils Ann , Alessi Marie-Christine , Brouwers Els , Peeters Miet , Marx Pauline , Leurs Judith , Bouma Bonno , Hendriks Dirk , Juhan-Vague Irène , Declerck Paul J.
Published: May 2003

Objective—

A Thr/Ile polymorphism at position 325 in the coding region of proCPU has been reported. Immunological assays, fully characterized (including genotype dependency), are required for the quantitation of proCPU levels.

Methods and Results—

We have generated a panel of monoclonal antibodies against human, plasma-derived proCPU. Two combinations exhibiting distinct reactivities were selected for measurement of proCPU in plasma. T12D11/T28G6-HRP yielded values of 10.1±3.1 μg/mL (mean±SD, n=86; normal donors), and T32F6/T9G12-HRP yielded values of 5.4±3.0 μg/mL. Grouping according to the 325 genotype demonstrated that T12D11/T28G6-HRP was independent to this polymorphism whereas T32F6/T9G12-HRP revealed a complete lack of reactivity with the Ile/Ile genotype (ie, 0.0±0.0, 4.2±1.7, and 7.3±2.9 μg/mL for the Ile/Ile, Ile/Thr, and Thr/Thr isoforms, respectively). Commercially available antigen assays appeared to be partially dependent on the 325 genotype (eg, 44±8.9% and 100±30% for the Ile/Ile and Thr/Thr isoforms, respectively).

Conclusions—

Our data demonstrate that great care should be taken when evaluating proCPU antigen values as a putative causative agent or as a diagnostic risk marker for cardiovascular events.
Effect of Oral and Transdermal Estrogen Replacement Therapy on Hemostatic Variables Associated With Venous Thrombosis
Authors: Post Marinka S. , Christella M. , Thomassen L.G.D. , van der Mooren Marius J. , van Baal W. Marchien , Rosing Jan , Kenemans Peter , Stehouwer Coen D.A.
Published: May 2003

Objective—

The purpose of this study was to investigate whether the effect of transdermal estrogen therapy in postmenopausal women differs from that of oral therapy with regard to resistance to activated protein C (APC), an important risk factor for venous thrombosis, and levels of related proteins, such as protein S, protein C, and prothrombin.

Methods and Results—

In a randomized, double-blind, placebo-controlled study, 152 healthy hysterectomized postmenopausal women received daily either placebo (n=49), transdermal 17β-estradiol (E
2
) 50 μg (tE
2
group, n=33), oral E
2
1 mg (oE
2
group, n=37), or oral E
2
1 mg combined with gestodene 25 μg (oE
2
+G group, n=33) for 13 28-day treatment cycles, followed by 4 cycles of placebo for each group. Plasma samples were collected at baseline and in cycles 4, 13, and 17. In cycle 13, significant increases versus baseline and placebo were found in normalized APC sensitivity ratios (nAPCsr) in all treated groups (tE
2
, +26.9%; oE
2
, +102.7%; oE
2
+G, +69.9%). Increases in nAPCsr were significantly higher in the oral treatment groups than in the tE
2
group. In addition, compared with baseline and placebo, after 13 cycles, decreases were observed in total protein S (tE
2
, −4.1%; oE
2
, −7.9%; oE
2
+G, −5.8%), free protein S (tE
2
, −7.1%; oE
2
, −8.4%; oE
2
+G, −5.2%), and protein C in the oE
2
+G group (−6.4%), but these changes did not explain the increase in nAPCsr. Changes in prothrombin were small and also did not affect the nAPCsr.

Conclusions—

Increases were observed in resistance to APC, which were more pronounced in the oral treatment groups than in the transdermal group. The increase in resistance to APC was not explained by changes in protein S, protein C, or prothrombin and may contribute to the increased incidence of venous thrombosis in users of hormone replacement therapy.
Amino Acid Differences in the Deduced 5-Lipoxygenase Sequence of CAST Atherosclerosis-Resistance Mice Confer Impaired Activity When Introduced Into the Human Ortholog
Authors: Kuhn Hartmut , Anton Monika , Gerth Christa , Habenicht Andreas
Published: May 2003

Objectives—

The mouse strain CON6, which was generated by breeding athero-resistant CAST mice into an athero-susceptible B6 background, exhibits almost complete resistance to atherosclerosis. An athero-resistance gene cluster has been localized at the central region of chromosome 6, and among the candidate genes of this locus, the 5-lipoxygenase has attracted particular attention because of its involvement in the biosynthesis of proinflammatory leukotrienes. Comparison of 5-lipoxygenase genomic sequences of B6 and CON6 mice indicated 2 conserved amino acid exchanges in the CON6 animals, but the functional impact of these mutations has not been defined.

Methods and Results—

We analyzed the functionality of these amino acid exchanges relative to essential catalytic properties (specific activity, substrate affinity, and reaction specificity) and found that these mutations confer an impaired lipoxygenase and leukotriene A
4
-synthase activity when introduced into the human enzyme. In contrast, substrate affinity, enantiomer selectivity, and positional specificity remained unchanged.

Conclusions—

These data are consistent with the possibility that naturally occurring conservative mutations in the coding region of the murine 5-lipoxygenase gene can significantly affect enzyme activity and that this loss of function may be involved in CAST/CON6 athero-resistance.
Osteopontin Deficiency Attenuates Atherosclerosis in Female Apolipoprotein E–Deficient Mice
Authors: Matsui Yutaka , Rittling Susan R. , Okamoto Hiroshi , Inobe Manabu , Jia Nan , Shimizu Toshihiro , Akino Masatoshi , Sugawara Takeshi , Morimoto Junko , Kimura Chiemi , Kon Shigeyuki , Denhardt David , Kitabatake Akira , Uede Toshimitsu
Published: May 2003

Objective—

Osteopontin (OPN), a noncollagenous adhesive protein, is implicated in atherosclerosis, in which macrophages within atherosclerotic plaques express OPN. However, it is not known whether the elevated OPN expression is a cause or result of atherosclerosis.

Methods and Results—

We generated mice that lacked OPN and crossed them with apolipoprotein (apo) E–deficient mice and analyzed these mice with a mixed C57BL/6×129 background after 36 weeks on a normal chow diet. In female mice, OP
+/
−
E
−/−
and OP
−/−
E
−/−
mice had significantly smaller atherosclerotic and inflammatory lesions compared with OP
+/+
E
−/−
mice, and that was reflected by smaller area of MOMA-2–positive staining. In male mice, however, there was no significant difference in the atherosclerosis lesion areas among 3 genotypes. In both OP
−/−
E
−/−
and OP
+/+
E
−/−
mice, typical atherosclerotic lesions were detected, which include necrotic core, foamy cell collections, and cholesterol clefts. However, we found that vascular mineral-deposited areas in 60-week-old male OP
−/−
E
−/−
mice were significantly increased compared with those in OP
+/+
E
−/−
male mice.

Conclusions—

These results suggest that OPN plays a promoting effect in atherosclerosis and inhibitory effect in vascular calcification. The suppression of OPN expression in females should be considered a therapeutic possibility in atherosclerosis.
Effects of Cyclooxygenases Inhibitors on Vasoactive Prostanoids and Thrombin Generation at the Site of Microvascular Injury in Healthy Men
Authors: Tuleja Ewa , Mejza Filip , Cmiel Adam , Szczeklik Andrzej
Published: May 2003

Objective—Balance between vasoactive prostanoids that contribute to homeostasis of the circulatory system can be affected by cyclooxygenases inhibitors. Results of a recent large clinical trial show that myocardial infarction was more frequent among patients with rheumatoid arthritis treated with the selective cyclooxygenase-2 inhibitor rofecoxib compared with those treated with naproxen. Whether this difference was attributable to deleterious cardiovascular effects of rofecoxib or cardioprotective effects of naproxen has not been determined. We tested the hypothesis that naproxen, contrary to rofecoxib, exerts antithrombotic effects.

Methods and Results—Forty-five healthy men were randomized to receive a 7-day treatment with rofecoxib (50 mg/d), naproxen (1000 mg/d), aspirin (75 mg/d), or diclofenac (150 mg/d). Formation of thromboxane, prostacyclin, and thrombin in the bleeding-time blood at the site of standardized microvascular injury was assessed before and after treatment. Naproxen, like aspirin, caused significant reduction of both thromboxane and prostacyclin, whereas diclofenac depressed prostacyclin synthesis but had no effect on tromboxane formation. Naproxen and aspirin significantly suppressed thrombin generation. Diclofenac showed a similar tendency, which did not reach statistical significance. Rofecoxib had no effect on any variables measured.

Conclusions—In healthy men, naproxen exerts an antithrombotic effect at least as potent as aspirin, whereas rofecoxib does not affect hemostatic balance.
Increased Serum Levels of Heat Shock Protein 70 Are Associated With Low Risk of Coronary Artery Disease
Authors: Zhu Jianhui , Quyyumi Arshed A. , Wu Hongsheng , Csako Gyorgy , Rott David , Zalles-Ganley Alexandra , Ogunmakinwa Jibike , Halcox Julian , Epstein Stephen E.
Published: May 2003

Objective—

Previous studies suggest that heat shock protein (HSP) 60 has a contributory role in atherosclerosis development. We examined whether circulating HSP70 protein and anti-HSP70 antibodies are associated with coronary artery disease (CAD).

Methods and Results—

Blood samples from 421 patients (62% men, mean age 57 years) evaluated for CAD by coronary angiography were tested. Serum HSP70 was detectable in 67% of study subjects with levels ranging from 0.2 to 27.1 ng/mL (mean, 1.08; median, 0.5). HSP70 levels were higher in non-CAD patients than CAD patients (median, 0.72 versus 0.34;
P
=0.0006). Individuals with HSP70 levels above the median (0.5 ng/mL) had half the risk of CAD than individuals with levels below the median (adjusted odds ratio, 0.52; 95% confidence limit, 0.32 to 0.86). The association of high HSP70 levels with low CAD risk was independent of traditional CAD risk factors (
P
=0.011). Disease severity (number of diseased vessels) was also inversely associated with HSP70 protein levels (
P
=0.010). The adjusted odds ratio of having multivessel disease for patients with high HSP70 protein levels was 0.54 (95% confidence limit, 0.36 to 0.81). In contrast, no association between anti-HSP70 IgG seropositivity and the prevalence of CAD was found (
P
=0.916).

Conclusions—

These data provide the first evidence that high levels of human HSP70 are associated with the low CAD risk, probably through its multiple protective effects on a cell’s response to stress.
Genes, Environment, and Cardiovascular Disease
Authors: Sing Charles F. , Stengård Jari H. , Kardia Sharon L.R.
Published: May 2003

In this essay, we call to attention what every medical researcher knows about the etiology of cardiovascular disease but most deny, or choose to ignore, when designing, carrying out, and reporting genetic studies. Medical research is entering an era of synthesis that will take advantage of the successes of reductionism over the past decade in defining and describing human genome variations. Meaningful insights into the role of such variation requires a biological model of genome-phenotype relationships that incorporates interactions between subsets of possible genetic and environmental agents as causations in particular contexts indexed by time and space. We make recommendations for what needs to be done to cope with these complexities.
Captopril Ameliorates Myocarditis in Acute Experimental Chagas Disease
Authors: Leon Juan S. , Wang Kegiang , Engman David M.
Published: May 2003

Background—

Captopril, an angiotensin-converting enzyme inhibitor, is commonly prescribed to patients with Chagas heart disease (CHD). There are few human studies and no animal studies on the effects of captopril in CHD. We investigated the effects of captopril on myocarditis and the host immune response to
Trypanosoma cruzi
in an experimental model of acute CHD.

Methods and Results—

A/J mice infected with Brazil strain of
T cruzi
developed acute myocarditis by day 21 after infection, consisting of severe focal inflammation, necrosis, fibrosis, and
T cruzi
pseudocysts. Administration of captopril (5 mg/L in the water) significantly reduced necrosis and fibrosis in infected mice. Increasing the captopril dose also led to a decrease in inflammation. Captopril did not affect overall mortality but did delay death while having no effect on parasitemia or cardiac parasite load. Treatment did not affect humoral immunity against
T cruzi
or cardiac myosin (autoimmunity) but did decrease delayed-type hypersensitivity responses against both antigens. Interestingly, increasing the dose of captopril induced mortality in infected mice in a dose-dependent manner. Mortality was apparently not due to
T cruzi
because neither parasitemia nor cardiac parasitosis was affected. The combination of captopril and infection may have impaired renal function because these mice had increased water consumption, decreased body mass, and increased serum BUN/creatinine ratio.

Conclusions—

Captopril ameliorates the myocarditis associated with acute
T cruzi
infection.
TRAIL Promotes the Survival and Proliferation of Primary Human Vascular Endothelial Cells by Activating the Akt and ERK Pathways
Authors: Secchiero Paola , Gonelli Arianna , Carnevale Edvige , Milani Daniela , Pandolfi Assunta , Zella Davide , Zauli Giorgio
Published: May 2003

Background—

TRAIL protein is expressed in the medial smooth cell layer of aorta and pulmonary artery, whereas endothelial cells express all TRAIL receptors (TRAIL-Rs).

Methods and Results—

The role of TRAIL/TRAIL-Rs in vascular biology was investigated in primary human umbilical vein endothelial cells (HUVECs) and aortic endothelial cells, which showed comparable surface expression of death (TRAIL-R1 and -R2) and decoy (TRAIL-R3 and -R4) TRAIL-Rs. TRAIL activated the protein kinase Akt in HUVECs, as assessed by Western blot for phospho-Akt. Moreover, experiments performed with a pharmacological inhibitor of the phosphatidylinositol 3-kinase/Akt pathway (LY294002) or a dominant-negative Akt (K179M) demonstrated that TRAIL significantly protected HUVECs from apoptosis induced by trophic withdrawal via Akt and that inhibition of Akt sensitized HUVECs to TRAIL-induced caspase-dependent apoptosis. TRAIL also stimulated the ERK1/2 but not the p38 or the JNK pathways and induced a significant increase in endothelial cell proliferation in an ERK-dependent manner. Conversely, TRAIL did not activate NF-κB or affect the surface expression of the inflammatory markers E-selectin, intercellular adhesion molecule-1, and vascular cell adhesion molecule-1.

Conclusions—

The ability of TRAIL to promote the survival/proliferation of endothelial cells without inducing NF-κB activation and inflammatory markers suggests that the TRAIL/TRAIL-R system plays an important role in endothelial cell physiology.
Receptor for AGE (RAGE) Mediates Neointimal Formation in Response to Arterial Injury
Authors: Zhou Zhongmin , Wang Kai , Penn Marc S. , Marso Steven P. , Lauer Michael A. , Forudi Farhad , Zhou Xiaorong , Qu Wu , Lu Yan , Stern David M. , Schmidt Ann Marie , Lincoff A. Michael , Topol Eric J.
Published: May 2003

Background—

Receptor for advanced-glycation end products (RAGE) and its ligands AGEs and S100/calgranulins have been implicated in a range of disorders. However, the role of RAGE/ligand interaction in neointimal hyperplasia after vascular injury remains unclear.

Methods and Results—

We examined the expression of RAGE and its ligands after balloon injury of the carotid artery in both Zucker diabetic and nondiabetic rats. Using a soluble portion of the extracellular domain of RAGE, we determined the effects of suppressing RAGE/ligand interaction on vascular smooth muscle cell (VSMC) proliferation and neointimal formation after arterial injury. We demonstrate a significantly increased accumulation of AGE and immunoreactivities of RAGE and S100/calgranulins in response to balloon injury in diabetic compared with nondiabetic rats. Blockade of RAGE/ligand interaction significantly decreased S100-stimulated VSMC proliferation in vitro and bromodeoxyuridine (BrdU)–labeled proliferating VSMC in vivo, and suppressed neointimal formation and increased luminal area in both Zucker diabetic and nondiabetic rats.

Conclusions—

These findings indicate that RAGE/ligand interaction plays a key role in neointimal formation after vascular injury irrespective of diabetes status and suggest a novel target to minimize neointimal hyperplasia.
Imaging Electrocardiographic Dispersion of Depolarization and Repolarization During Ischemia
Authors: Nash Martyn P. , Bradley Chris P. , Paterson David J.
Published: May 2003

Background—

Myocardial ischemia creates abnormal electrophysiological substrates that result in life-threatening ventricular arrhythmias. Identifying patients at risk of such abnormalities by use of body surface electrical measures is controversial. We investigated the sensitivity of torso measures, recorded simultaneously with epicardial electrograms, to changes in dispersion of depolarization and repolarization during localized ventricular ischemia.

Methods and Results—

Ventricular epicardial electrograms were recorded from 5 anesthetized pigs with a 127-electrode sock. A controllable suture snare was used to ligate the left anterior descending coronary artery (LAD). The chest was reclosed, and a vest with 256 ECG electrodes was fitted to the torso. Simultaneous arrays of epicardial electrograms and torso ECGs were recorded during LAD occlusion and reperfusion. Activation-recovery intervals (ARIs), QT
u
and RT
u
dispersion (where u indicates upstroke), and QRST integrals were calculated, and these data were fitted to anatomically customized computational models of the swine ventricular epicardium and torso. LAD occlusion caused the epicardial ARI dispersion to steadily increase, whereas the location of shortest ARI shifted from the posterobasal ventricular tissue (control) to the anteroapical myocardium, distal to the suture snare. These changes were associated with a steady increase in the torso RT
u
dispersion as the shortest RT
u
interval moved from the right shoulder (control) to the sternum. QT
u
and RT
u
dispersion determined from the 12-lead ECG did not consistently reflect the myocardial changes.

Conclusions—

Although changes in myocardial repolarization dispersion resulting from localized ischemia are not reliably reflected in temporal indices derived from the 12-lead ECG, they can be readily identified with high-resolution torso ECG mapping.
Single Injection of P-Selectin or P-Selectin Glycoprotein Ligand-1 Monoclonal Antibody Blocks Neointima Formation After Arterial Injury in Apolipoprotein E-Deficient Mice
Authors: Phillips J. William , Barringhaus Kurt G. , Sanders John M. , Hesselbacher Sean E. , Czarnik Ann C. , Manka David , Vestweber Dietmar , Ley Klaus , Sarembock Ian J.
Published: May 2003

Background—

Emerging data suggest that P-selectin, by controlling adhesion of white blood cells, may be important in limiting the response to vascular injury.

Methods and Results—

We tested the hypothesis that transient inhibition of P-selectin with either anti-P-selectin monoclonal antibody (mAb) or anti-P-selectin glycoprotein ligand-1 (PSGL-1) mAb would reduce neointima formation in the setting of carotid denudation injury in atherosclerosis-prone apolipoprotein E
−/−
mice. Neointima formation at 28 days was reduced significantly, by 50% or 80%, by a single injection on the day of injury of 100 or 200 μg P-selectin mAb RB 40.34 and by 55% by a single injection of 100 μg PSGL-1 mAb 4RA10 (
P
≤0.005). In addition, there was a significant reduction in neointimal macrophage content.

Conclusions—

These findings demonstrate that transient P-selectin or PSGL-1 blockade at the time of arterial injury significantly limits plaque macrophage content and neointima formation in a dose-dependent manner after carotid denudation injury in apolipoprotein E
−/−
mice.