bluuebunny/crossref_metadata_2025_split huggingface dataset:
Parasitism levels in Orgyia leucostigma feeding on two tree species: implications for the slow‐growth‐ high‐mortality hypothesis
Authors: Medina Raul F. , Barbosa Pedro , Waddell Kim 
Published: April 2005

AbstractThe slow‐growth‐high‐mortality hypothesis proposes that increased development time in arthropods feeding on suboptimal food may result in an increased vulnerability to natural enemies. We measured the development time of the forest caterpillar Orgyia leucostigma J.E. Smith (Lepidoptera: Lymantriidae: Orgyiini) on two of its host plants and used a 7‐year database on parasitism of this species to test the slow‐growth‐high‐mortality hypothesis. We found that female O. leucostigma developed faster when fed on willow (Salix nigra Marsh) than when fed on box elder (Acer negundo L.). However, only one of the parasitoids of the parasitoid community that attack these larvae followed the prediction of the slow‐growth‐high‐mortality hypothesis. Overall parasitism of O. leucostigma on willow was greater than in box elder, contradicting the slow‐growth‐high‐mortality hypothesis prediction. This is the first test of the hypothesis to consider parasitism by several species in the parasitoid community attacking a free‐feeding herbivore on two distantly related plant species.
Molecular interactions between rosy apple aphids, Dysaphis plantaginea, and resistant and susceptible cultivars of its primary host Malus domestica
Authors: Qubbaj T. , Reineke A. , Zebitz C. P. W. 
Published: April 2005

AbstractThe use of crop varieties resistant or tolerant to insect pests or other stress factors is one approach in non‐chemical crop‐protection. Knowledge of the biochemical and molecular background of insect–plant interactions is a prerequisite for optimizing breeding for resistance. However, the resistance genes involved in plant–aphid interactions have so far only been identified and characterized in very few plant species. Our work aims to elucidate the molecular and biochemical mechanisms involved in resistance of apple trees, Malus domestica L. (Rosaceae), against its primary aphid pest, the rosy apple aphid, Dysaphis plantaginea (Passerini) (Homoptera: Aphididae), which is considered a serious economic pest of apple. Gene expression in both resistant and susceptible apple cultivars after infestation with rosy apple aphids was investigated by employing the cDNA‐AFLP method (cDNA–Amplified Fragment Length Polymorphism). From approximately 12 500 cDNA fragments detected on polyacrylamide gels, 21 bands were apparently up‐ or down‐regulated only in the resistant cultivar ‘Florina’ after aphid infestation compared to the susceptible cultivar ‘Topaz’ and/or mechanically wounded or non‐infested leaves. These fragments were cloned, sequenced, and the pattern of gene expression for six fragments was subsequently verified by virtual Northern blots. Sequence comparisons of these fragments to GenBank accessions revealed homologies to already known genes, most of them isolated from Arabidopsis thaliana L. Among them, a putative RNase‐L‐inhibitor‐like protein, a pectinacetylesterase, an inositol‐phosphatase‐like protein, a precursor of the large chain of the ribulose‐1,5‐biphosphate‐carboxylase, and defence‐related genes such as a vacuolar H(+)‐ATPase subunit‐like protein and an ADP‐ribosylating enzyme were identified. The results are discussed in relation to a putative role of these genes in conferring aphid resistance in apple trees.
Electrophysiological and behavioural responses of Melolontha melolontha to saturated and unsaturated aliphatic alcohols
Authors: Reinecke Andreas , Ruther Joachim , Hilker Monika 
Published: April 2005

AbstractMale Melolontha cockchafers are known to use green leaf volatiles induced by female feeding on host plants for their mate location. Earlier studies of the response of the European cockchafer, Melolontha melolontha L. (Coleoptera: Scarabaeidae), to different green leaf aldehydes, alcohols, and acetates revealed that only green leaf alcohols were attractive to males in the field. Females were not attracted at all by these volatiles. Here, we present a study that aimed to elucidate the structure–activity relationships of aliphatic alcohols. Both behavioural and physiological responses were studied in male and female M. melolontha by field tests and electroantennography. The compounds tested were saturated aliphatic alcohols with chain lengths between five and eight carbon atoms. Furthermore, the cockchafer's response to six‐carbon alcohols with (E)‐2‐, (E)‐3‐, (Z)‐2‐, (Z)‐3‐, and (Z)‐4‐configurated double bonds was tested. All compounds elicited dose‐dependent responses on the antennae of both sexes. In general, males showed a stronger normalized EAG response to the stimuli than females. However, only the naturally occurring six‐carbon alcohols, i.e., 1‐hexanol (E)‐2‐, (Z)‐3, and (E)‐3‐hexen‐1‐ol were attractive to M. melolontha males in the field. Females were not attracted to any of the tested compounds, confirming previous results on the olfactory orientation of Melolontha cockchafers.
Interaction between cucumber plants and the broad mite, Polyphagotarsonemus latus: from damage to defense gene expression
Authors: Grinberg Mor , Perl‐Treves Rafael , Palevsky Eric , Shomer Ilan , Soroker Victoria 
Published: April 2005

AbstractThe broad mite (BM), Polyphagotarsonemus latus (Banks) (Acari: Tarsonemidae), is a minute polyphagous mite that has severe effects on the host plant. Mechanisms of BM injury and subsequent plant responses are unclear. In this study we characterized the morphological and molecular reactions of cucumber plants (Cucumis sativus L., Cucurbitaceae) to BM infestation. Infested plants showed growth inhibition and a decrease in leaf number and leaf area. There was also an increase in the firmness of the infested leaves, as measured by a texture analyzer. Broad mite feeds on the epidermis, but structural and ultrastructural studies revealed aberrations in the whole leaf tissue. Severe infestation led to a complete loss of epidermis and an increase in mesophyll cell size and number. In transmission electron microscope (TEM) images, the entire epidermal tissue appeared to have collapsed, and the mesophyll cell walls appeared thick and distorted. In the infested leaves, a Northern blot analysis revealed the induction of genes related to the jasmonic acid (JA)/ethylene and salicylic acid (SA) pathways, such as lipoxygenase (LOX) and β‐1,3 glucanase (BGL2), and an induction of oxidative stress‐responsive transcripts, such as peroxidase (PRX). Transcript levels of ACC oxidase (ACO) that participate in ethylene biosynthesis, remained relatively constant. This work reveals that BM feeding causes dramatic morphological, structural, and ultrastructural changes, along with an induction of genes involved in defense pathways. Further studies are needed to evaluate whether the observed changes in leaf structure and ultrastructure affect the mite, and how the induction of the defense pathways affects the susceptibility of plants to BM infestations.
Response of the elm leaf beetle to host plants induced by oviposition and feeding: the infestation rate matters
Authors: Meiners T. , Hacker N.K. , Anderson P. , Hilker M. 
Published: April 2005

AbstractWe investigated by olfactometry and feeding‐ and oviposition‐choice‐tests how the highly specialised elm leaf beetle, Xanthogaleruca luteola Müller (Coleoptera: Chrysomelidae), responds to conspecifically induced defences in the field elm Ulmus minor Miller (Ulmaceae). While egg deposition of the beetle induced elms to release volatiles attractive to the egg parasitoid Oomyzus gallerucae Fonscolombe (Hymenoptera: Eulophidae), feeding alone did not. In the present study, females of the elm leaf beetle showed preferences for the odours of twigs induced by low egg deposition and feeding over odours from uninfested twigs. In contrast, heavy infestation rendered elm odours less attractive to the beetles. Feeding and oviposition bioassays revealed an oviposition preference for leaves from uninfested twigs when compared to locally infested leaves. However, beetles preferred to feed upon systemically induced leaves compared to uninfested ones. The different preferences of the elm leaf beetle during host plant approach might be explained by a strategy that accounts for both gaining access to high quality nutrition and avoiding competition or parasitism.
Clinical Applications of Functional Magnetic Resonance Imaging
Authors: Voets N. L. , Matthews P. M. 
Published: April 2005

SummaryBlood oxygenation level‐dependent (BOLD) functional magnetic resonance imaging (fMRI) provides a new tool for neuroradiology. The BOLD fMRI allows functional changes to be distinguished, even in the absence of structural changes in the brain. Up until now, routine clinical applications largely have been limited to localizing eloquent brain regions in pre‐surgical planning. However, in exploratory applications, the method has allowed new insights into mechanisms of brain plasticity, helping clinicians better appreciate its importance in recovery after brain injury. Several new areas of application may be anticipated based on current research work, including for pre‐symptomatic disease detection, testing drug dose–activity relationships, and the diagnosis and characterization of somatization disorders. A major direction of methodological research is towards integration of fMRI with other techniques, particularly electrophysiological methods. The emphasis that these new approaches to imaging will place on understanding functional changes associated with disease challenges current neuroradiological training and service delivery models. They emphasize the need to develop closer relationship between neuroradiology and the traditional clinical neurosciences.
THE STATE OF THE HOME EQUITY SECURITIES MARKET (AND HOW TO IMPROVE IT): REPORT FROM A RECENT CONFERENCE
Authors: Youngblood Michael D. 
Published: April 2005

In 1998, a year which saw the origination of a record volume of single‐family mortgage loans, at least 12 of the top 20 home equity lenders experienced severe problems related to their business models, accounting practices, and access to the debt and equity markets. In march of 1999, Banc of America Securities (BAS) sponsored a conference to explore the causes of and possible solutions to these problems.This article begins by tracing the industry's problems to lenders' inability to sell the subordinated and residual classes of home equity securities, and goes on to argue that the key to the regular distribution of these securities lies in enhancing the quality and depth of information that lenders provide investors about the underlying loans. The article discusses four proposals for improving lenders' disclosure—proposals that are designed to increase institutional investors' demand for home equity securities by helping them to assess the prepayment and credit risk associated with the securities.Following the author's summary of the BAS proposals, the article concludes with selected comments on the future of the home equity securities markets by two panels of experts representing bond insurers and rating agencies.
Trichomonas vaginalis
Polyamine Metabolism Is Linked to Host Cell Adherence and Cytotoxicity
Authors: Garcia Ana F. , Benchimol M. , Alderete J. F. 
Published: April 2005

ABSTRACT

Trichomonas vaginalis
secretes putrescine that is readily detected in vaginal secretions. We wanted to examine the effect of decreased putrescine synthesis by inhibition of ornithine decarboxylase (ODC) on
T. vaginalis
. One reason is because inhibition of
Tritrichomonas foetus
ODC results in growth arrest, destruction of hydrogenosomes, and decreased amounts of hydrogenosomal enzymes. Treatment of
T. vaginalis
T016 with ≥20 mM 1,4-diamino-2-butanone (DAB) to inhibit ODC resulted in growth arrest, which was reversed by addition of exogenous putrescine. No similar reversal of growth arrest was achieved with the polyamines spermine or spermidine or with iron. Electron microscopic examination of control versus DAB-treated trichomonads did not reveal any adverse effects on the number and integrity of hydrogenosomes. Further, the adhesins AP65, AP51, and AP33 mediating binding to immortalized vaginal epithelial cells (VECs) share identity to enzymes of the hydrogenosome organelle, and there was no difference in amounts of adhesins between control versus DAB-treated
T. vaginalis
parasites. Likewise, similar patterns and extent of fluorescence were evident for the prominent AP65 adhesin. Surprisingly, DAB treatment increased by 4- to 20-fold above untreated trichomonads handled identically the level of adherence mediated by adhesins. Interestingly, the enhanced attachment to VECs was reversed by exogenous putrescine added to DAB-treated trichomonads. Equally noteworthy was that DAB-treated
T. vaginalis
with enhanced adherence did not possess the previously reported ability to kill host cells in a contact-dependent fashion mediated by cysteine proteinases, and total cysteine proteinase activity patterns were identical between control and DAB-treated trichomonads. Overall, these data suggest that polyamine metabolism and secreted putrescine are linked to host cell adherence and cytotoxicity.
Microarray and Proteomics Analyses of Human Intestinal Epithelial Cells Treated with theAeromonas hydrophilaCytotoxic Enterotoxin
Authors: Galindo C. L. , Fadl A. A. , Sha Jian , Pillai L. , Gutierrez C. , Chopra A. K. 
Published: April 2005

ABSTRACTWe performed microarray analyses on RNA from human intestinal epithelial (HT-29) cells treated with the cytotoxic enterotoxin (Act) ofAeromonas hydrophilato examine global cellular transcriptional responses. Based on three independent experiments, Act upregulated the expression of 34 genes involved in cell growth, adhesion, signaling, immune responses (including interleukin-8 [IL-8] production), and apoptosis. We verified the upregulation of 14 genes by real-time reverse transcriptase-PCR and confirmed Act-induced production of IL-8 by enzyme-linked immunosorbent assay on supernatants from nonpolarized and polarized HT-29 cells. Maximal production of IL-8 in response to Act required the presence of intracellular calcium, since chelation of calcium with BAPTA-AM significantly reduced Act-induced IL-8 production in HT-29 cells. We also examined activation of mitogen-activated protein kinases and, as demonstrated by Western blot analysis of apical side-treated polarized HT-29 cells, Act induced phosphorylation of p38, c-Jun NH2-terminal kinase, and extracellular signal-regulated kinase 1/2. In addition, KinetWorks proteomics screening of whole-cell lysates revealed Act-induced phosphorylation of cyclic AMP-response element binding protein (CREB), c-Jun, adducin, protein kinase C, and signal transducer and activator of transcription 3 (STAT3) and decreased phosphorylation of protein kinase Bα, v-raf-1 murine leukemia viral oncogene homolog 1 (i.e., Raf1), and STAT1. We verified activation of CREB and activator protein 1 in polarized cells by gel shift assay. This is the first description of human intestinal epithelial cell transcriptional alterations, phosphorylation or activation of signaling molecules, cytokine production, and calcium mobilization in response to this toxin.
Differential Binding ofEscherichia coliEnterotoxins LT-IIa and LT-IIb and of Cholera Toxin Elicits Differences in Apoptosis, Proliferation, and Activation of Lymphoid Cells
Authors: Arce Sergio , Nawar Hesham F. , Russell Michael W. , Connell Terry D. 
Published: April 2005

ABSTRACTCholera toxin (CT), LT-IIa, and LT-IIb are potent adjuvants which induce distinct T-helper (Th)-cell cytokine profiles and immunoglobulin G (IgG) subclass and IgA antibody responses. To determine if the distinct immune regulatory effects observed for LT-IIa, LT-IIb, and CT are elicited by binding of the enterotoxins to their cognate ganglioside receptors, the lineages of lymphoid cells that interact with the three enterotoxins and their effects on various lymphocyte responses in vitro were evaluated. Binding patterns of LT-IIa, LT-IIb, and CT to several lymphoid cell populations were distinctive for each enterotoxin. LT-IIa and CT, but not LT-IIb, induced apoptosis in CD8+T cells. LT-IIa(T34I), a mutant with no detectable binding to gangliosides, did not induce apoptosis. Blockade of GM1on the surface of CD8+T cells by LT-IIa(T14I), a mutant that binds only to GM1but does not induce apoptosis, did not inhibit induction of apoptosis by LT-IIa. Mitogen-induced proliferation of CD8+T cells was abrogated by treatment with CT, while resting CD8+T cells which were sensitive to LT-IIa-induced apoptosis became more resistant to apoptosis after mitogen activation. Exposure to CT, but not to LT-IIa or LT-IIb, inhibited mitogen-driven CD4+T-cell proliferation and expression of CD25 and CD69. In mitogen-stimulated B cells, CT, but not LT-IIa or LT-IIb, enhanced expression levels of CD86, while only CT induced B-cell differentiation into plasma cells. Thus, LT-IIa, LT-IIb, and CT exhibit distinguishable immunomodulatory properties which are likely dependent upon their capacities to recognize different ganglioside receptors on lymphocytes.
Identification of an Immunomodulating Agent fromMycobacterium leprae
Authors: Maeda Yumi , Mukai Tetsu , Spencer John , Makino Masahiko 
Published: April 2005

ABSTRACTA search for an immunomodulating agent from mycobacteria was carried out usingMycobacterium leprae. The antigenicity of each fraction of the bacterial membrane, which contains the most antigenic components ofM. leprae, was assessed by using sera from paucibacillary leprosy. N-terminal sequencing of the serum-reactive protein and functional assessment of the membrane fractions using monocyte-derived dendritic cells (DCs) identified major membrane protein II (MMP-II) as one of the efficient T-cell-activating candidates. Purified MMP-II stimulated DCs from healthy individuals to produce interleukin-12 p70 and up-regulated the surface expression of major histocompatibility complex class I and II, CD86, and CD83 molecules. Also, there was an increase in the percentage of CD83+cells in the DC population. Furthermore, MMP-II-pulsed DCs expressed their derivatives on their surfaces. Using Toll-like receptor 2 (TLR-2)-dependent receptor constructs, we found that TLR-2 signaling was involved in DC maturation induced by MMP-II. Taken together, MMP-II can be recognized as an immunomodulating protein in terms of activation of antigen-presenting cells and innate immunity.
Genomic Subtraction Followed by Dot Blot Screening of
Streptococcus pneumoniae
Clinical and Carriage Isolates Identifies Genetic Differences Associated with Strains That Cause Otitis Media
Authors: Pettigrew Melinda M. , Fennie Kristopher P. 
Published: April 2005

ABSTRACT

Streptococcus pneumoniae
strains are the leading cause of bacterial otitis media, yet little is known about specific bacterial factors important for this disease. We utilized a molecular epidemiological approach involving genomic subtraction of the
S. pneumoniae
serogroup 19 middle ear strain 5093 against the laboratory strain R6. Resulting subtraction PCR (sPCR) products were used to screen a panel of 93 middle ear, 90 blood, 35 carriage, and 58 cerebrospinal fluid isolates from young children to identify genes found more frequently among middle ear isolates. Probe P41, similar to a hypothetical protein of
Brucella melitensis
, occurred among 41% of middle ear isolates and was found 2.8 (95% confidence interval [CI], 1.32 to 6.5), 3.3 (95% CI, 1.9 to 5.7), and 1.8 (95% CI, 1.1 to 3.0) times more frequently among middle ear strains than carriage, blood, or meningitis strains, respectively. sPCR fragment H10, similar to an unknown
Streptococcus agalactiae
protein, was present in 31% of middle ear isolates and occurred 3.6 (95% CI, 1.2 to 11.2), 2.8 (95% CI, 1.5 to 5.4), and 2.6 (95% CI, 1.2 to 5.5) times more often among middle ear isolates than carriage, blood, or meningitis strains, respectively. These studies have identified two genes of potential importance in otitis media virulence. Further studies are warranted to outline the precise role of these genes in otitis media pathogenesis.
Boosting of DNA Vaccine-Elicited Gamma Interferon Responses in Humans by Exposure to Malaria Parasites
Authors: Wang Ruobing , Richie Thomas L. , Baraceros Maria Fe , Rahardjo Nancy , Gay Tanya , Banania Jo-Glenna , Charoenvit Yupin , Epstein Judith E. , Luke Thomas , Freilich Daniel A. , Norman Jon , Hoffman Stephen L. 
Published: April 2005

ABSTRACTA mixture of DNA plasmids expressing fivePlasmodium falciparumpre-erythrocyte-stage antigens was administered with or without a DNA plasmid encoding human granulocyte-macrophage colony-stimulating factor (hGM-CSF) as an immune enhancer. After DNA immunization, antigen-specific gamma interferon (IFN-γ) responses were detected by ELISPOT in 15/31 volunteers to multiple class I- and/or class II-restricted T-cell epitopes derived from all five antigens. Responses to multiple epitopes (≤7) were detected simultaneously in some volunteers. By 4 weeks after challenge withP. falciparumparasites, 23/31 volunteers had positive IFN-γ responses and the magnitude of responses was increased from 2- to 143-fold. Nonetheless, none was protected against malaria. Volunteers who received hGM-CSF had a reduced frequency of IFN-γ responses to class I peptides compared to those who only received plasmids expressingP. falciparumproteins before challenge (3/23 versus 3/8;P= 0.15) or after parasite challenge (4/23 versus 5/8;P= 0.015) but not to class II peptides before or after challenge. The responses to one antigen (P. falciparumcircumsporozoite protein [PfCSP]) were similar among volunteers who received the five-gene mixture compared to volunteers who only received the PfCSP DNA plasmid in a previous study. In summary, DNA-primed IFN-γ responses were boosted in humans by exposure to native antigen on parasites, coadministration of a plasmid expressing hGM-CSF had a negative effect on boosting of class I-restricted IFN-γ responses, and there was no evidence that immunization with PfCSP DNA in the mixture reduced T-cell responses to PfCSP compared to when it was administered alone.
Human Lyme Arthritis and the Immunoglobulin G Antibody Response to the 37-Kilodalton Arthritis-Related Protein of
Borrelia burgdorferi
Authors: Salazar Carlos A. , Rothemich Monika , Drouin Elise E. , Glickstein Lisa , Steere Allen C. 
Published: April 2005

ABSTRACT

In
Borrelia burgdorferi
-infected C3H-
scid
mice, antiserum to a differentially expressed, 37-kDa spirochetal outer-surface protein, termed arthritis-related protein (Arp), has been shown to prevent or reduce the severity of arthritis. In this study, we determined the immunoglobulin G (IgG) antibody responses to this spirochetal protein in single serum samples from 124 antibiotic-treated human patients with early or late manifestations of Lyme disease and in serial serum samples from 20 historic, untreated patients who were followed longitudinally from early infection through the period of arthritis. These 20 patients were representative of the spectrum of the severity and duration of Lyme arthritis. Among the 124 antibiotic-treated patients, 53% with culture-proven erythema migrans (EM) had IgG responses to recombinant glutathione
S
-transferase (GST)-Arp, as did 59% of the patients with facial palsy and 68% of those with Lyme arthritis. In addition, 75 to 80% of the 20 past, untreated patients had reactivity with this protein when EM was present, during initial episodes of joint pain, or during the maximal period of arthritis. There was no association at any of these three time points between GST-Arp antibody levels and the severity of the maximal attack of arthritis or the total duration of arthritis. Thus, after the first several weeks of infection, 60 to 80% of patients had IgG antibody responses to GST-Arp, but this response did not correlate with the severity or duration of Lyme arthritis.