bluuebunny/crossref_metadata_2025_split huggingface dataset:
Do grains whisper for help? Evidence for herbivore‐induced synomones in wheat grains
Authors: Steidle Johannes L.M. , Fischer André , Gantert Cornelia 
Published: April 2005

AbstractThus far, the release of herbivore‐induced synomones (HIS) has almost exclusively been demonstrated in somatic plant tissue. Here we present evidence for the production of HIS from reproductive tissue, i.e., seeds. The study system consisted of wheat grains (Triticum aestivum L., Poaceae) infested by larvae of the granary weevil Sitophilus granarius L. (Coleoptera, Curculionidae), which in turn are attacked by the parasitic wasp Lariophagus distinguendus Förster (Hymenoptera, Pteromalidae). The use of potential chemical signals from the infested grain for host recognition of L. distinguendus was studied with weevil‐infested grains that had developed under a range of humidity conditions. Wasps always performed longer antennal drumming on infested than healthy grains, demonstrating that they were able to recognize infested grains under all humidity conditions. In grains developed at a high humidity (75% r.h.), host recognition is enabled by chemical signals arising from the host faeces which densely cover infested grains. However, in grains from a low humidity (45% r.h.) almost no faeces are present, indicating that other cues are used by the wasp. Control experiments revealed that these other cues are neither chemical signals from faeces contaminations, volatiles from faeces nor host larvae inside the grain, movement of host larvae, or moisture content of infested grains. Therefore, wasp recognition of infested grains in low humidity conditions is probably based on chemical signals from the grain itself that are induced by the feeding of granary weevil larva. Further experiments revealed that infested grains increase their viability when granary weevil larvae are killed by the idiobiont L. distinguendus. This justifies the categorisation of potential signals from the grain as HIS. To our knowledge, this is the only system where potential HIS in plant seeds have been studied. We discuss whether potential HIS are actively produced by infested grains or are a by‐product of grain metabolism.
FINANCING INNOVATIONS AND CAPITAL STRUCTURE CHOICES
Authors: Damodaran Aswath 
Published: April 2005

The last two decades have seen a stream of innovation in financial markets, especially in corporate bonds. Some of these innovations—notably, hybrid debt—have provided firms with more flexibility in designing cash flows on borrowings, allowing them to match cash flows on financing more closely to cash flows on assets. In so doing, the use of such innovative securities has increased corporate debt capacity and hence firm value.But if such changes have been mostly good news for corporate treasurers, the relentless torrent of innovation has sometimes resulted in firms issuing these new securities for the wrong reasons. Some have done so to take advantage of loopholes in the way ratings agencies and regulatory agencies define debt and equity—and others to exploit perceived pricing anomalies—without considering the effect of such securities on the firm's overall risk profile. In this context, it is worth noting that as corporate bonds have become more complex, investment bankers have made themselves indispensable to the process by providing pricing as well as selling support. This article aims to help managers distinguish when financing with complex securities serves their company's interests, and when it can end up hurting them.
RECENT DEVELOPMENTS IN THE HIGH YIELD MARKET
Authors: Bouhuys Henk , Jaeger Stephan 
Published: April 2005

After a period of virtually uninterrupted growth stretching from 1994 through the first half of 1998, the high yield market suffered a sudden, jarring setback that led to the widest credit spreads seen since 1991. With the global spread of the Asian flu in August, spreads became so wide that the market for new issues virtually ceased. The most frequently used word to describe conditions in the high yield market during this period was “carnage.”Then, in response to the Federal Reserve's series of rate cuts beginning in late September, the market staged a modest recovery that carried through the end of the year. Since then, the market has experienced several periods of alternating strength and weak ness, and new issuance has moderated relative to the record levels of a year ago. This article examines last year's volatile new issue environment and analyzes recent developments that can be expected to influence financing opportunities for corporate issuers in the near future.
Interpolating Three-Dimensional Kinematic Data Using Quaternion Splines and Hermite Curves
Authors: Coburn James , Crisco Joseph J. 
Published: April 2005

Abstract
Kinematic interpolation is an important tool in biomechanics. The purpose of this work is to describe a method for interpolating three-dimensional kinematic data, minimizing error while maintaining ease of calculation. This method uses cubic quaternion and hermite interpolation to fill gaps between kinematic data points. Data sets with a small number of samples were extracted from a larger data set and used to validate the technique. Two additional types of interpolation were applied and then compared to the cubic quaternion interpolation. Displacement errors below 2% using the cubic quaternion method were achieved using 4% of the total samples, representing a decrease in error over the other algorithms.
CD4+T Cells but Not CD8+or γδ+Lymphocytes Are Required for Host Protection againstMycobacterium aviumInfection and Dissemination through the Intestinal Route
Authors: Petrofsky Mary , Bermudez Luiz E. 
Published: April 2005

ABSTRACTDisseminatedMycobacterium aviuminfection is common in AIDS patients that do not receive anti-AIDS therapy and in patients for whom therapy fails.M. aviumis commonly acquired by ingestion, and a large number of AIDS patients haveM. aviumin their intestinal tracts. To better understand the dynamics of the infection in patients with AIDS, we studied orally infected mice. To determine if immunocompetent mice challenged orally withM. aviumcan develop protection against the infection, and if so, which cell population(s) is responsible for the protection, we exposed wild-type as well as CD4−/−, CD8−/−, and γδ−/−knockout mice to low concentrations ofM. aviumstrain 101 given orally, followed by treatment with azithromycin. After 1 month, the mice were challenged with kanamycin-resistantM. avium104. Only CD4+T cells appeared to be required for protection against the second challenge. Both CD4+and CD8+T cells produced comparable amounts of gamma interferon after the first exposure to the bacterium. Tumor necrosis factor alpha was elevated in CD4+T cells but not in CD8+T cells. Following exposure to a small inoculum of mycobacteria orally, wild-type mice did not develop disseminated infection for approximately 4 months, although viable bacteria could be observed in the mesenteric lymph nodes. The ingestion of small numbers ofM. aviumcells induces a protective immune response in the intestines against subsequent infection. However, the bacteria remain viable in intestinal lymph nodes and might disseminate later.
Trypanosomes Expressing a Mosaic Variant Surface Glycoprotein Coat Escape Early Detection by the Immune System
Authors: Dubois Melissa E. , Demick Karen P. , Mansfield John M. 
Published: April 2005

ABSTRACTHost resistance to African trypanosomiasis is partially dependent on an early and strong T-independent B-cell response against the variant surface glycoprotein (VSG) coat expressed by trypanosomes. The repetitive array of surface epitopes displayed by a monotypic surface coat, in which identical VSG molecules are closely packed together in a uniform architectural display, cross-links cognate B-cell receptors and initiates T-independent B-cell activation events. However, this repetitive array of identical VSG epitopes is altered during the process of antigenic variation, when former and nascent VSG proteins are transiently expressed together in a mosaic surface coat. Thus, T-independent B-cell recognition of the trypanosome surface coat may be disrupted by the introduction of heterologous VSG molecules into the coat structure. To address this hypothesis, we transformedTrypanosoma brucei rhodesienseLouTat 1 with the 117 VSG gene fromTrypanosoma brucei bruceiMiTat 1.4 in order to produce VSG double expressers; coexpression of the exogenous 117 gene along with the endogenous LouTat 1 VSG gene resulted in the display of a mosaic VSG coat. Results presented here demonstrate that the host's ability to produce VSG-specific antibodies and activate B cells during early infection with VSG double expressers is compromised relative to that during infection with the parental strain, which displays a monotypic coat. These findings suggest a previously unrecognized mechanism of immune response evasion in which coat-switching trypanosomes fail to directly activate B cells until coat VSG homogeneity is achieved. This process affords an immunological advantage to trypanosomes during the process of antigenic variation.
Legionella pneumophilaEvades Gamma Interferon-Mediated Growth Suppression through Interleukin-10 Induction in Bone Marrow-Derived Macrophages
Authors: Yoshizawa Sadako , Tateda Kazuhiro , Matsumoto Tetsuya , Gondaira Fumio , Miyazaki Shuichi , Standiford Theodore J. , Yamaguchi Keizo 
Published: April 2005

ABSTRACTWe examined the roles of Th1-Th2 cytokine cross talk inLegionella pneumophila-infected bone marrow-derived (BM) macrophages in the presence of costimulation with interleukin-12 (IL-12) and IL-18. Treatment with gamma interferon (IFN-γ) alone or treatment with IL-12 in combination with IL-18 resulted in a 3- or 2-log reduction in bacterial numbers, respectively, in BM macrophages, whereas treatment with IL-12 or IL-18 alone had no effect. Significant amounts of IFN-γ were detected in the culture supernatants of infected macrophages stimulated with IL-12 and IL-18 in combination but not independently. Neutralization of IFN-γ by antibody completely abolished the growth inhibitory effects of IL-12 and IL-18. Interestingly, higher infectivity ratios ofL. pneumophilaor the addition of increasing concentrations of heat-killed bacteria (HKB) suppressed the production of IFN-γ, which resulted in the increased intracellular growth of bacteria. Significant amounts of IL-10 were detected in culture supernatants whenLegionella-infected macrophages were cocultured with HKB. Furthermore, neutralization of IL-10 by antibody resulted in an increase in IFN-γ production by infected BM macrophages when cocultured with HKB. Treatment of HKB with trypsin but not polymyxin B attenuated the growth-promoting effects of HKB, suggesting the involvement of a protein component(s) in regulation of the growth ofL. pneumophila. These findings demonstrate a crucial role of Th1-Th2 cross talk inL. pneumophila-infected BM macrophages. Our results also suggest thatL. pneumophilamodulates the cytokine balance from IFN-γ-driven Th1 to more Th2 responses, likely through the induction of IL-10 by a bacterial protein component(s). These data provide new insights not only into the cellular mechanisms of Th1-Th2 cross talk inLegionella-infected macrophages but also into the pathogenesis ofL. pneumophilapneumonia in humans.
Helicobacter pyloriBinds to CD74 on Gastric Epithelial Cells and Stimulates Interleukin-8 Production
Authors: Beswick Ellen J. , Bland David A. , Suarez Giovanni , Barrera Carlos A. , Fan Xuejung , Reyes Victor E. 
Published: April 2005

ABSTRACTThe pathogenesis associated withHelicobacter pyloriinfection requires consistent contact with the gastric epithelium. Although several cell surface receptors have been suggested to play a role in adhesion, the bacterium-host interactions that elicit host responses are not well defined. This study investigated the interaction ofH. pyloriwith the class II major histocompatibility complex (MHC)-associated invariant chain (Ii; CD74), which was found to be highly expressed by gastric epithelial cells. Bacterial binding was increased when CD74 surface expression was increased by gamma interferon (IFN-γ) treatment or by fibroblast cells transfected with CD74, while binding was decreased by CD74 blocking antibodies, enzyme cleavage of CD74, and CD74-coated bacteria.H. pyloriwas also shown to bind directly to affinity-purified CD74 in the absence of class II MHC. Cross-linking of CD74 and the engagement of CD74 were verified to stimulate IL-8 production by unrelated cell lines expressing CD74 in the absence of class II MHC. Increased CD74 expression by cells increased IL-8 production in response toH. pylori, and agents that block CD74 decreased these responses. The binding ofH. pylorito CD74 presents a novel insight into an initial interaction ofH. pyloriwith the gastric epithelium that leads to upregulation of inflammatory responses.
Role of Interleukin-6 in Mortality from and Physiologic Response to Sepsis
Authors: Remick Daniel G. , Bolgos Gerald , Copeland Shannon , Siddiqui Javed 
Published: April 2005

ABSTRACT
Previous studies have suggested that interleukin-6 (IL-6) serves as both a marker and a mediator for the severity of sepsis. We tested whether interleukin 6 knockout (IL-6KO) mice were more susceptible to sepsis mortality induced by cecal ligation and puncture. IL-6KO and wild-type (WT) mice were subjected to increasing degrees of sepsis severity. Physiologic support was given with fluids and appropriate antibiotics. Plasma IL-6 levels were determined 6 h after the onset of sepsis, and a complete hematologic profile was performed on day 2. As expected, increasing sepsis severity resulted in greater and more rapid mortality. However, the mortality was nearly identical in the IL-6KO and WT mice. All WT septic mice had high plasma levels of IL-6 6 h after the onset of sepsis, while IL-6KO were near or below the lower limit of detection. Among the WT mice, mortality was significantly higher in mice with plasma IL-6 >3,000 pg/ml. Both IL-6KO and WT mice destined to die in the early stages of sepsis had substantial and nearly identical weight gain in the first 24 h. However, at later stages the WT mice had significantly greater weight loss than the KO mice. The KO mice failed to develop the characteristic hypothermia within the first 24 h of severe sepsis routinely observed in the WT mice. These data demonstrate that IL-6 serves as a marker of disease severity in sepsis and does modulate some physiologic responses, but complete lack of IL-6 does not does not alter mortality due to sepsis.
The Surface Protein Pls of Methicillin-Resistant
Staphylococcus aureus
Is a Virulence Factor in Septic Arthritis
Authors: Josefsson Elisabet , Juuti Katri , Bokarewa Maria , Kuusela Pentti 
Published: April 2005

ABSTRACT

Pls, a surface protein of certain methicillin-resistant
Staphylococcus aureus
strains, is associated with poor bacterial adherence to solid-phase fibronectin and immunoglobulin G, as well as with reduced invasion of cultured epithelial cells. Here the importance of Pls for the development of septic arthritis and sepsis was investigated by using a mouse model. Mice inoculated with a
pls
knockout mutant developed a much milder arthritis and showed less grave weight reduction than mice infected with the wild-type Pls
+
clinical isolate. Also, the
pls
mutant induced a significantly lower frequency of mortality than the wild-type strain. The bacterial load of the kidneys was larger in mice infected with the Pls
+
strain than in animals challenged with the
pls
mutant. However, there was no evident inflammatory effect due to the Pls molecule alone, as indicated by knee injection of purified Pls. In conclusion, the results show that Pls is a virulence factor for septic arthritis and sepsis.
Identification of Genes Required for Avian
Escherichia coli
Septicemia by Signature-Tagged Mutagenesis
Authors: Li Ganwu , Laturnus Claudia , Ewers Christa , Wieler Lothar H. 
Published: April 2005

ABSTRACT

Infections with avian pathogenic
Escherichia coli
(APEC) cause colibacillosis, an acute and largely systemic disease resulting in significant economic losses in poultry industry worldwide. Although various virulence-associated genes have been identified in APEC, their actual role in pathogenesis is still not fully understood, and, furthermore, certain steps of the infection process have not been related to previously identified factors. Here we describe the application of a signature-tagged transposon mutagenesis (STM) approach to identify critical genes required for APEC infections in vivo. Twenty pools of about 1,800 IMT5155 (O2:H5) mutants were screened in an infection model using 5-week-old chickens, and potentially attenuated mutants were subjected to a secondary screen and in vivo competition assays to confirm their attenuation. A total of 28 genes required for
E. coli
septicemia in chickens were identified as candidates for further characterization. Among these disrupted genes, six encode proteins involved in biosynthesis of extracellular polysaccharides and lipopolysaccharides; two encode iron transporters that have not been previously characterized in APEC in in vivo studies, and four showed similarity to membrane or periplasmic proteins. In addition, several metabolic enzymes, putative proteins with unknown function, and open reading frames with no similarity to other database entries were identified. This genome-wide analysis has identified both novel and previously known factors potentially involved in pathogenesis of APEC infection.
Characterization of
Salmonella
-Induced Cell Death in Human Macrophage-Like THP-1 Cells
Authors: Valle Eulalia , Guiney Donald G. 
Published: April 2005

ABSTRACT

Salmonella
strains are facultative intracellular pathogens that produce marked cytopathology during infection of host cells. Different forms of cytopathic effects have been associated with the virulence systems encoded by the two
Salmonella
pathogenicity islands (SPI-1 and SPI-2) and the
spv
locus. We used
Salmonella enterica
serovar Dublin to investigate the induction of cytopathology during infection of the human macrophage-like cell line THP-1. Analysis of host cells by flow cytometry using a fluorescent terminal deoxynucleotidyltransferase dUTP-biotin nick end labeling (TUNEL) assay revealed that 70% of THP-1 cells showed DNA fragmentation after 4 h of infection, increasing to greater than 90% by 5.5 h. Moreover, the results showed that gentamicin-killed or chloramphenicol-treated bacteria did not induce DNA fragmentation. Serovar Dublin strains with mutations in SPI-1, SPI-2, or
spvB
induced these cytopathic effects similar to wild-type bacteria. In contrast, a mutation in the
phoP
regulatory gene abolished DNA fragmentation in the TUNEL assay. Caspase-3 activation was detected during
Salmonella
infection of THP-1 cells, but caspase-8 and caspase-9 activities were not found. However, inhibition of caspase-3 did not block
Salmonella
-induced DNA fragmentation. These results identify a previously undetected apoptotic effect in
Salmonella
-infected cells that is dependent on
phoP
gene function.
Binding Properties and Adhesion-Mediating Regions of the Major Sheath Protein ofTreponema denticolaATCC 35405
Authors: Edwards Andrew M. , Jenkinson Howard F. , Woodward Martin J. , Dymock David 
Published: April 2005

ABSTRACTThere is growing evidence that a number of oralTreponemaspecies, in particularTreponema denticola, are associated with the progression of human periodontal disease. The major sheath (or surface) protein (Msp) ofT. denticolais implicated in adhesion of bacteria to host cells and tissue proteins and is likely to be an important virulence factor. However, the binding regions of the Msp are not known. We have purified fromEscherichia colirecombinant Msp (rMsp) polypeptides corresponding to the following: full-length Msp (rMsp) minus 13 N-terminal amino acid (aa) residues, an amino-terminal fragment (rN-Msp, 189 aa residues), a 57-aa residue segment from the central region (rV-Msp), and a C-terminal fragment (rC-Msp, 272 aa residues). rMsp (530 aa residues) bound to immobilized fibronectin, keratin, laminin, collagen type I, fibrinogen, hyaluronic acid, and heparin. The N- and V-region polypeptides, but not rC-Msp, also bound to these substrates. Binding of rMsp to fibronectin was targeted to the N-terminal heparin I/fibrin I domain. Antibodies to the N-region or V-region polypeptides, but not antibodies to the rC-Msp fragment, blocked adhesion ofT. denticolaATCC 35405 cells to a range of host protein molecules. These results suggest that the N-terminal half of Msp carries epitopes that are surface exposed and that are involved in mediating adhesion. Binding of rMsp onto the cell surface of low-level fibronectin-bindingTreponemaisolates conferred a 10-fold increase in fibronectin binding. This confirms that Msp functions autonomously as an adhesin and raises the possibility that phenotypic complementation of virulence functions might occur within mixed populations ofTreponemaspecies.
Serologic Responses to ACYW135 Polysaccharide Meningococcal Vaccine in Saudi Children under 5 Years of Age
Authors: Al-Mazrou Y. , Khalil M. , Borrow R. , Balmer P. , Bramwell J. , Lal G. , Andrews N. , Al-Jeffri M. 
Published: April 2005

ABSTRACTAn immunization campaign with meningococcal ACYW135 polysaccharide vaccine was conducted in 2003 by the Saudi Arabian Ministry of Health and included a study to evaluate the immune responses in children under 5 years of age in the Al Qassim region of Saudi Arabia. Children who were ≥24 months old were given one dose of tetravalent polysaccharide vaccine, while younger children were given two doses with an interval of 2 to 3 months. Blood samples were collected prevaccination and 1 month after the second dose for children younger than 24 months old and 1 month after the single dose for older children. Serogroup-specific antibody responses were determined by serum bactericidal antibody (SBA) assays and a tetraplex immunoglobulin G (IgG) bead assay. Significant increases in the proportions of individuals who were ≥24 months old with SBA titers of ≥8 were observed pre- to postvaccination for all serogroups. Age-dependent increases in the percentage of individuals with SBA titers of ≥8 1 month postvaccination were observed for each serogroup. Age-dependent increases in postvaccination IgG levels were observed for serogroup A (menA), serogroup W135 (menW), and serogroup Y (menY) but not for serogroup C (menC). Two doses of tetravalent polysaccharide vaccine in individuals who were ≤18 months old were poorly immunogenic for menC, menW, and menY. However, for menA, 42% of the children who were 18 months old were putatively protected with SBA titers of ≥8. A high percentage of subjects who were ≥2 years of age were putatively protected for menA; a similar level was observed for menY for children who were 4 years of age but not for younger children. However, for menC and menW poor levels of putative protection were still evident at 4 years of age.