bluuebunny/crossref_metadata_2025 huggingface dataset:
Cloning and Sequencing of a Genomic Island Found in the Brazilian Purpuric Fever Clone of
Haemophilus influenzae
Biogroup Aegyptius
Authors: McGillivary Glen , Tomaras Andrew P. , Rhodes Eric R. , Actis Luis A.
Published: March 2005

A genomic island was identified in the
Haemophilus influenzae
biogroup aegyptius Brazilian purpuric fever (BPF) strain F3031. This island, which was also found in other BPF isolates, could not be detected in non-BPF biogroup aegyptius strains or in nontypeable or typeable
H. influenzae
strains, with the exception of a region present in the type b Eagan strain. This 34,378-bp island is inserted, in reference to
H. influenzae
Rd KW20, within a choline transport gene and contains a mosaic structure of Mu-like prophage genes, several hypothetical genes, and genes potentially encoding an
Erwinia carotovora
carotovoricin Er-like bacteriocin. The product of the tail fiber ORF in the bacteriocin-like region shows a hybrid structure where the C terminus is similar to an
H. influenzae
phage HP1 tail protein implicating this open reading frame in altering host specificity for a putative bacteriocin. Significant synteny is seen in the entire genomic island with genomic regions from
Salmonella enterica
subsp.
enterica
serovar Typhi CT18,
Photorhabdus luminescens
subsp.
laumondii
TT01,
Chromobacterium violaceum
, and to a lesser extent
Haemophilus ducreyi
35000HP. In a previous work, we isolated several BPF-specific DNA fragments through a genome subtraction procedure, and we have found that a majority of these fragments map to this locus. In addition, several subtracted fragments generated from an independent laboratory by using different but related strains also map to this island. These findings underscore the importance of this BPF-specific chromosomal region in explaining some of the genomic differences between highly invasive BPF strains and non-BPF isolates of biogroup aegyptius.
The TibA Adhesin/Invasin from EnterotoxigenicEscherichia coliIs Self Recognizing and Induces Bacterial Aggregation and Biofilm Formation
Authors: Sherlock Orla , Vejborg Rebecca Munk , Klemm Per
Published: March 2005

Escherichia colistrains are responsible for many cases of gastrointestinal disease and represent a serious health problem worldwide. An essential step in the pathogenesis of such strains involves recognition and attachment to host intestinal surfaces. TibA is a potent bacterial adhesin associated with a number of enterotoxigenicE. colistrains and mediates bacterial attachment to a variety of human cells; additionally, it promotes invasion of such cells. This adhesin is a surface-displayed autotransporter protein and belongs to the exclusive group of bacterial glycoproteins; only the glycosylated form confers binding to and invasion of mammalian cells. Here we characterized TibA and showed that it possesses self-association characteristics and can mediate autoaggregation ofE. colicells. We demonstrated that intercellular TibA-TibA interaction is responsible for bacterial autoaggregation. Also, TibA expression significantly enhances biofilm formation byE. colion abiotic surfaces.
Interactions of
Neisseria gonorrhoeae
with Adherent Polymorphonuclear Leukocytes
Authors: Simons Mark P. , Nauseef William M. , Apicella Michael A.
Published: March 2005

Neisseria gonorrhoeae
causes severe exudative urethritis. The exudates from infected individuals contain large numbers of polymorphonuclear leukocytes (PMN) with ingested gonococci. The fate of
N. gonorrhoeae
within PMN has been a topic of debate for years. In this study, we examined the interactions of
N. gonorrhoeae
with PMN adherent to surfaces as a system that better models events during clinical disease. Using chemiluminescence to measure reactive oxygen species (ROS), we found that
N. gonorrhoeae
stimulated PMN to produce a respiratory burst. Different kinetics were seen when PMN were stimulated with opsonized zymosan particles. In addition, ROS were produced predominantly inside the PMN in response to gonococci. Laser scanning confocal microscopy and transmission electron microscopy showed that
N. gonorrhoeae
rapidly associated with PMN under these experimental conditions and was internalized. Some gonococci were cleared in the first 30 to 60 min after phagocytosis, but a majority of the population persisted for 6 h after phagocytosis. Quantification of viable organisms showed that a significant portion of the population resisted killing. The viability of this subpopulation remained unchanged for 2 h after phagocytosis. A significant increase of viable gonococci from 1 to 6 h was also observed, suggesting intracellular replication. Four different
N. gonorrhoeae
strains demonstrated the same capacity to resist PMN-mediated killing, whereas
Escherichia coli
was rapidly killed by PMN under the same conditions. Taken together, these findings suggest that a subpopulation of
N. gonorrhoeae
resists killing and replicates within PMN phagosomes in spite of NADPH oxidase activation.
Differential Involvement of Toll-Like Receptors 2 and 4 in the Host Response to Acute Respiratory Infections with Wild-Type and MutantHaemophilus influenzaeStrains
Authors: Lorenz Eva , Chemotti Diana C. , Jiang Alice L. , McDougal Letitia D.
Published: March 2005

We used a mouse model of acute respiratory infections to investigate the role of Toll-like receptor 2 (TLR2) and TLR4 in the host response toHaemophilus influenzae. Acute aerosol exposures to wild-type strains ofH. influenzaeshowed that TLR4 function was essential for TNF-α induction, neutrophil influx, and bacterial clearance. To determine how lipooligosaccharide (LOS) modifications would affect the role of TLR4 in inducing the host response, we used acute infections with anH. influenzaestrain expressing a mutation in thehtrBgene. This mutant strain expresses an LOS subunit with decreased acylation. In response toH. influenzae htrBinfection, tumor necrosis factor alpha (TNF-α) secretion remained TLR4 dependent. But the decrease in LOS acylation made the neutrophil influx and the bacterial clearance also dependent on TLR2, as shown by the decreased host response elicited in TLR2 knockout mice compared to C57BL/6 mice. A subsequent analysis of TLR2 and TLR4 gene expression by quantitative PCR indicated that TLR4 function induces TLR2 expression and vice versa. These results indicate that some changes in the LOS subunit ofH. influenzaecan favor signaling through non-TLR4 receptors, such as TLR2. The results also indicate a close interaction between TLR4 and TLR2 that tightly regulates the expression of both receptors.
A Deficiency in Gamma Interferon or Interleukin-10 Modulates T-Cell-Dependent Responses to Heat Shock Protein 60 fromHistoplasma capsulatum
Authors: Scheckelhoff Mark , Deepe George S.
Published: March 2005

Immunization of mice with heat shock protein 60 fromHistoplasma capsulatumor a polypeptide from the protein designated F3 confers protection. Vβ8.1/8.2+T cells are critically important for the protective efficacy of this antigen. The production of interleukin-10 and gamma interferon following vaccination is essential for efficacy. In this study, we sought to determine whether the absence of either cytokine modified the repertoire of antigen-reactive T cells and whether it altered the functional properties of T cells. Mice lacking gamma interferon or interleukin-10 manifested a skewed repertoire compared to that of wild-type mice. The bias was most marked in gamma interferon-deficient mice and modestly altered in interleukin-10-deficient animals. The altered repertoire in gamma interferon-deficient mice could not be explained at the level of antigen presentation or by the absence of this population from mice. The proportion of T cells from interleukin-10-deficient mice manifesting a Th1 phenotype was greatly increased compared to that from wild-type animals. Transfer of splenocytes from gamma interferon- or interleukin-10-deficient mice immunized with heat shock protein 60 failed to confer protection in T-cell receptor α/β−/−mice. The transfer of T-cell clones that did not produce both cytokines failed to prolong survival in T-cell receptor α/β−/−mice, whereas the clones with the same features that were derived from wild-type mice did. These results indicate that the cytokine milieu influences the shape of the T-cell receptor repertoire and support the importance of gamma interferon and interleukin-10 in the efficacy of heat shock protein 60.
Surfactant Protein D Is Present in Human Tear Fluid and the Cornea and Inhibits Epithelial Cell Invasion byPseudomonas aeruginosa
Authors: Ni Minjian , Evans David J. , Hawgood Samuel , Anders E. Margot , Sack Robert A. , Fleiszig Suzanne M. J.
Published: March 2005

We have previously shown that human tear fluid protects corneal epithelial cells againstPseudomonas aeruginosain vitro and in vivo and that protection does not depend upon tear bacteriostatic activity. We sought to identify the responsible tear component(s). The hypothesis tested was that collectins (collagenous calcium-dependent lectins) were involved. Reflex tear fluid was collected from healthy human subjects and examined for collectin content by enzyme-linked immunosorbent assay (ELISA) and Western blot with antibody against surfactant protein D (SP-D), SP-A, or mannose-binding lectin (MBL). SP-D, but not SP-A or MBL, was detected by ELISA of human reflex tear fluid. Western blot analysis of whole tears and of high-performance liquid chromatography tear fractions confirmed the presence of SP-D, most of which eluted in the same fraction as immunoglobulin A. SP-D tear concentrations were calculated at ∼2 to 5 μg/ml. Depletion of SP-D with mannan-conjugated Sepharose or anti-SP-D antibody reduced the protective effect of tears againstP. aeruginosainvasion. Recombinant human or mouse SP-D used alone reducedP. aeruginosainvasion of epithelial cells without detectable bacteriostatic activity or bacterial aggregation. Immunofluorescence microscopy revealed SP-D antibody labeling throughout the corneal epithelium of normal, but not gene-targeted SP-D knockout mice. SP-D was also detected in vitro in cultured human and mouse corneal epithelial cells. In conclusion, SP-D is present in human tear fluid and in human and mouse corneal epithelia. SP-D is involved in human tear fluid protection againstP. aeruginosainvasion. Whether SP-D plays other roles in the regulation of other innate or adaptive immune responses at the ocular surface, as it does in the airways, remains to be explored.
Differential Effects of Prior Exposure to Environmental Mycobacteria on Vaccination withMycobacterium bovisBCG or a Recombinant BCG Strain Expressing RD1 Antigens
Authors: Demangel Caroline , Garnier Thierry , Rosenkrands Ida , Cole Stewart T.
Published: March 2005

In silico analysis reveals that most protective antigens expressed by the antituberculous vaccineMycobacterium bovisBCG (BCG) are conserved inM. avium, supporting the hypothesis that exposure to environmental mycobacteria generates cross-reactive immune responses blocking BCG activity. We investigated the impact of sensitization withM. avium,M. scrofulaceum, orM. vaccaeon the protective efficacy of a recombinant BCG strain expressing RD1 antigens (BCG::RD1), using a mouse model of experimental tuberculosis (TB). No evidence that the RD1-encoded antigens ESAT-6, CFP-10, and PPE68 were expressed by these environmental strains could be demonstrated by Western blot analysis. Mice sensitized with each of these strains did not prime cellular immune responses cross-reacting with the immunodominant ESAT-6. Importantly, clearance of BCG::RD1 from the lungs and spleens of mice exposed to each of the environmental strains before vaccination was minimal compared to that of BCG. In mice sensitized withM. avium, increased persistence of BCG::RD1 correlated with stronger antimycobacterial gamma interferon responses and enhanced protection against aerosol infection withM. tuberculosis, compared to BCG. In contrast, animals exposed toM. scrofulaceumorM. vaccaeprior to vaccination with BCG or BCG::RD1 were better protected against TB than were the unsensitized controls. Our results suggest that the inhibitory effect of environmental mycobacteria on the protective efficacy of BCG depends critically on the extent of cross-recognition of antigens shared with the vaccine. In hosts sensitized withM. avium, potent immunogenicity of ESAT-6 and increased persistence of BCG::RD1 may allow this recombinant vaccine to overcome preexisting antimycobacterial responses.
Elucidation of the Monoclonal Antibody 5G8-Reactive, Virulence-Associated Lipopolysaccharide Epitope ofHaemophilus influenzaeand Its Role in Bacterial Resistance to Complement-Mediated Killing
Authors: Griffin Ruth , Cox Andrew D. , Makepeace Katherine , Richards James C. , Moxon E. Richard , Hood Derek W.
Published: March 2005

The phase-variable locuslex2is required for expression of aHaemophilus influenzaelipopolysaccharide (LPS) epitope of previously unknown structure. This epitope, which is reactive with monoclonal antibody (MAb) 5G8, has been associated with virulence of type b strains. When strain RM118 (from the same source as strain Rd), in which thelex2locus and MAb 5G8 reactivity are absent, was transformed withlex2DNA, transformants that were reactive with MAb 5G8 were obtained. Surprisingly, the 5G8 reactivity of these transformants was phase variable, although thelex2locus lacked tetrameric repeats and was constitutively expressed. This phase variation was shown to be the result of phase-variable expression of phosphorylcholine (PCho) such that MAb 5G8 reacted only in the absence of PCho. Structural analysis showed that, compared to RM118, thelex2transformant had acquired a tetrasaccharide, Gal-α1,4-Gal-β1,4-Glc-β1,4-Glc-β1,4, linked to the proximal heptose (HepI). A terminal GalNAc was detected in a minority of glycoforms. LPS derived from a mutant of RM7004, a virulent type b strain which naturally expresseslex2and has LPS containing the same tetrasaccharide linked to HepI as the sole oligosaccharide extension from the inner core, confirmed that GalNAc is not a part of the MAb 5G8-reactive epitope. Thus, MAb 5G8 specifically binds to the structure Gal-α1,4-Gal-β1,4-Glc-β1,4-Glc-β attached via a 1,4 linkage to HepI ofH. influenzaeLPS, and we show that the ability to synthesize this novel tetrasaccharide was associated with enhanced bacterial resistance to complement-mediated killing.
Function of Neisserial Outer Membrane Phospholipase A in Autolysis and Assessment of Its Vaccine Potential
Authors: Bos Martine P. , Tefsen Boris , Voet Pierre , Weynants Vincent , van Putten Jos P. M. , Tommassen Jan
Published: March 2005

Outer membrane phospholipase A (OMPLA) is an outer membrane-localized enzyme, present in many gram-negative bacterial species. It is implicated in the virulence of several pathogens. Here, we investigated the presence, function, and vaccine potential of OMPLA in the human pathogen
Neisseria meningitidis
. Immunoblot analysis showed the presence of OMPLA in 28 out of 33 meningococcal strains investigated. The OMPLA-negative strains all contained a
pldA
gene, but these alleles contained premature stop codons. All six
Neisseria gonorrhoeae
strains tested, but only two out of seven commensal neisserial strains investigated, expressed OMPLA, showing that OMPLA is expressed by, but not limited to, many pathogenic neisserial strains. The function of OMPLA was investigated by assessing the phenotypes of isogenic strains, expressing no OMPLA, expressing wild-type levels of OMPLA, or overexpressing OMPLA. OMPLA exhibited phospholipase activity against endogenous phospholipids. Furthermore, OMPLA was characterized as an autolysin that acted under specific conditions, such as prolonged growth of the bacteria. The vaccine potential of the protein was investigated by immunizing mice with in vitro refolded, recombinant OMPLA. High levels of antibody titers were obtained, but the murine sera were neither bactericidal nor protective. Also, convalescent patients and vaccinee sera did not contain detectable levels of anti-OMPLA antibodies, indicating that OMPLA may not be sufficiently immunogenic to be included in a meningococcal vaccine.
The Natural Killer Complex Regulates Severe Malarial Pathogenesis and Influences Acquired Immune Responses toPlasmodium bergheiANKA
Authors: Hansen Diana S. , Evans Krystal J. , D'Ombrain Marthe C. , Bernard Nicholas J. , Sexton Adrienne C. , Buckingham Lynn , Scalzo Anthony A. , Schofield Louis
Published: March 2005

The natural killer complex (NKC) is a genetic region of highly linked genes encoding several receptors involved in the control of NK cell function. The NKC is highly polymorphic, and allelic variability of various NKC loci has been demonstrated in inbred mice. Making use of BALB.B6-Cmv1rcongenic mice, in which the NKC from disease-susceptible C57BL/6 mice has been introduced into the disease-resistant BALB/c background, we show here that during murine malaria infection, the NKC regulates a range of pathophysiological syndromes such as cerebral malaria, pulmonary edema, and severe anemia, which contribute to morbidity and mortality in human malaria. Parasitemia levels were not affected by the NKC genotype, indicating that control of malarial fatalities by the NKC cells does not operate through effects on parasite growth rate. Parasite-specific antibody responses and the proinflammatory gene transcription profile, as well as the TH1/TH2 balance, also appeared to be influenced by NKC genotype, providing evidence that this region, known to control innate immune responses via NK and/or NK T-cell activation, can also significantly regulate acquired immunity to infection. To date, NKC-encoded innate system receptors have been shown mainly to regulate viral infections. Our data provide evidence for critical NKC involvement in the broad immunological responses to a protozoan parasite.
Mouse Paneth Cell Secretory Responses to Cell Surface Glycolipids of Virulent and Attenuated Pathogenic Bacteria
Authors: Tanabe Hiroki , Ayabe Tokiyoshi , Bainbridge Brian , Guina Tina , Ernst Robert K. , Darveau Richard P. , Miller Samuel I. , Ouellette Andre J.
Published: March 2005

Mouse Paneth cells respond to bacteria and bacterial cell surface antigens by discharging secretory granules into the lumen of small intestinal crypts (T. Ayabe et al., Nat. Immunol.1:113-118, 2000). To investigate mechanisms regulating these responses, purified surface glycolipid molecules with known acyl chain modifications and attenuated properties were tested for the ability to stimulate Paneth cell secretion. The antigens included lipopolysaccharide (LPS) from wild-type andmsbB-nullEscherichia coliandphoP-null andphoP-constitutiveSalmonella entericaserovar Typhimurium strains, as well as LPS, lipid A, and lipoteichoic acid fromPseudomonas aeruginosaandListeria monocytogenesgrown in Mg2+-limited media. Measurements of total secreted protein, secreted lysozyme, and the bactericidal peptide activities of collected secretions showed that the purified antigens elicited similar secretory responses from Paneth cells in mouse crypts ex vivo, regardless of glycolipid acyl chain modification. Despite their impaired Tlr4 pathway, Paneth cells in ex vivo C3H/HeJ mouse crypts released equivalent amounts of bactericidal peptide activity in response to purified bacterial antigens, including lipid A. Thus, mouse Paneth cells respond equivalently to purified bacterial cell envelope glycolipids, regardless of functional Tlr4, the structural properties of glycolipid acyl chains, or their association with virulence in humans.
Gene Expression inPorphyromonas gingivalisafter Contact with Human Epithelial Cells
Authors: Hosogi Yumiko , Duncan Margaret J.
Published: March 2005

Porphyromonas gingivalis, a gram-negative oral anaerobe, is strongly associated with adult periodontitis. The adherence of the organism to host epithelium signals changes in both cell types as bacteria initiate infection and colonization and epithelial cells rally their defenses. We hypothesized that the expression of a defined set ofP. gingivalisgenes would be consistently up-regulated during infection of HEp-2 human epithelial cells.P. gingivalisgenome microarrays were used to compare the gene expression profiles of bacteria that adhered to HEp-2 cells and bacteria that were incubated alone. Genes whose expression was temporally up-regulated included those involved in the oxidative stress response and those encoding heat shock proteins that are essential to maintaining cell viability under adverse conditions. The results suggest that contact with epithelial cells induces inP. gingivalisstress-responsive pathways that promote the survival of the bacterium.
The UspA2 Protein of
Moraxella catarrhalis
Is Directly Involved in the Expression of Serum Resistance
Authors: Attia Ahmed S. , Lafontaine Eric R. , Latimer Jo L. , Aebi Christoph , Syrogiannopoulos George A. , Hansen Eric J.
Published: March 2005

Many strains of
Moraxella catarrhalis
are resistant to the bactericidal activity of normal human serum. Previous studies have shown that mutations involving the insertion of an antibiotic resistance cartridge into the
M. catarrhalis uspA2
gene resulted in the conversion of a serum-resistant strain to a serum-sensitive phenotype. In the present study, the deletion of the entire
uspA2
gene from the serum-resistant
M. catarrhalis
strain O35E resulted in a serum-sensitive phenotype and did not affect either the rate of growth or the lipooligosaccharide expression profile of this mutant. Inactivation of the classical complement pathway in normal human serum with Mg
2+
and EGTA resulted in the survival of this
uspA2
mutant. In contrast, blocking of the alternative complement pathway did not protect this
uspA2
mutant from complement-mediated killing. To determine whether the UspA2 protein is directly involved in serum resistance, transformation and allelic exchange were used to replace the
uspA2
gene in the serum-resistant strain O35E with the
uspA2
gene from the serum-sensitive
M. catarrhalis
strain MC317. The resultant O35E transformant exhibited a serum-sensitive phenotype. Similarly, when the
uspA2
gene from the serum-resistant strain O35E was used to replace the
uspA2
gene in the serum-sensitive strain MC317, the MC317 transformant acquired serum resistance. The use of hybrid O35E-MC317
uspA2
genes showed that the N-terminal half of the O35E protein contained a 102-amino-acid region that was involved in the expression of serum resistance. In addition, when the
uspA2
genes from strains O35E and MC317 were cloned and expressed in
Haemophilus influenzae
DB117, only the O35E UspA2 protein caused a significant increase in the serum resistance of the
H. influenzae
recombinant strain. These results prove that the UspA2 protein is directly involved in the expression of serum resistance by certain
M. catarrhalis
strains.
Human Leukocyte Antigen-DQ8 Transgenic Mice: a Model To Examine the Toxicity of Aerosolized Staphylococcal Enterotoxin B
Authors: Roy Chad J. , Warfield Kelly L. , Welcher Brent C. , Gonzales Raoul F. , Larsen Tom , Hanson Julie , David Chella S. , Krakauer Theresa , Bavari Sina
Published: March 2005

Staphylococcal enterotoxins (SEs) belong to a large group of bacterial exotoxins that cause severe immunopathologies, especially when delivered as an aerosol. SEs elicit the release of lethal amounts of cytokines by binding to major histocompatibility complex (MHC) class II and cross-linking susceptible T-cell receptors. Efforts to develop effective therapeutic strategies to protect against SEs delivered as an aerosol have been hampered by the lack of small animal models that consistently emulate human responses to these toxins. Here, we report that human leukocyte antigen-DQ8 (HLA-DQ8) transgenic (Tg) mice, but not littermate controls, succumbed to lethal shock induced by SEB aerosols without potentiation. Substantial amounts of perivascular edema and inflammatory infiltrates were noted in the lungs of Tg mice, similar to the pathology observed in nonhuman primates exposed by aerosol to SEB. Furthermore, the observed pathologies and lethal shock correlated with an upsurge in proinflammatory cytokine mRNA gene expression in the lungs and spleens, as well as with marked increases in the levels of proinflammatory circulating cytokines in the Tg mice. Unlike the case for littermate controls, telemetric evaluation showed significant hypothermia in Tg mice exposed to lethal doses of SEB. Taken together, these results show that this murine model will allow for the examination of therapeutics and vaccines developed specifically against SEB aerosol exposure and possibly other bacterial superantigens in the context of human MHC class II receptors.
Q Fever Pneumonia: Virulence of
Coxiella burnetii
Pathovars in a Murine Model of Aerosol Infection
Authors: Stein Andreas , Louveau Céline , Lepidi Hubert , Ricci Fanny , Baylac Pascal , Davoust Bernard , Raoult Didier
Published: March 2005

Q fever is a worldwide zoonosis caused by
Coxiella burnetii
, a strictly intracellular bacterium that is a potential bioweapon. Humans usually acquires Q fever after inhalation of dust infected by subclinical animals. We used an aerosol exposure apparatus to challenge immunocompetent (BALB/c) and severe combined immunodeficient (SCID) mice with two different strains (strain Nine Mile and strain Q 212) of
C. burnetii
at two different inocula. Pathological lesions and dissemination of the bacteria were related to the size of the inoculum. SCID mice showed major pulmonary lesions, whereas similarly infected BALB/c mice were more able to eliminate the bacteria. Pathological differences were found between the strains, with Nine Mile showing more severe histological lesions and quantified spread of bacteria. Our animal model could provide a new tool for the study of acute Q fever pneumonia, the development of Q fever in immunodeficient hosts, and the differentiation of pathogenicity among
C. burnetii
isolates.
Heterologous Immunity in the Absence of Variant-Specific Antibodies after Exposure to Subpatent Infection with Blood-Stage Malaria
Authors: Elliott Salenna R. , Kuns Rachel D. , Good Michael F.
Published: March 2005

We examined immunity induced by subpatent blood-stage malaria (undetectable by microscopy) using the rodent malaria parasite,Plasmodium chabaudi chabaudi, postulating that limited infection may allow expansion of antigen-specific T cells that are normally deleted by apoptosis. After three infections drug cured at 48 h, mice were protected against high-dose challenge with homologous or heterologous parasites (different strain or variant). Immunity differed from that generated by three untreated, patent infections. Subpatently infected mice lacked immunoglobulin G (IgG) to variant surface antigens, despite producing similar titers of total malaria-specific IgG to those produced by patently infected mice, including antibodies specific for merozoite surface antigens conserved between heterologous strains. Antigen-specific proliferation of splenocytes harvested prechallenge was significantly higher in subpatently infected mice than in patently infected or naive mice. In subpatently infected mice, lymphoproliferation was similar in response to homologous and heterologous parasites, suggesting that antigenic targets of cell-mediated immunity were conserved. A Th1 cytokine response was evident during challenge. Apoptosis of CD4+and CD8+splenic lymphocytes occurred during patent but not subpatent infection, suggesting a reason for the relative prominence of cell-mediated immunity after subpatent infection. In conclusion, subpatent infection with blood stage malaria parasites induced protective immunity, which differed from that induced by patent infection and targeted conserved antigens. These findings suggest that alternative vaccine strategies based on delivery of multiple parasite antigens at low dose may induce effective immunity targeting conserved determinants.
Potential Role of the Chemokine Macrophage Inflammatory Protein 1α in Human and Experimental Schistosomiasis
Authors: Souza Adriano L. S. , Roffê Ester , Pinho Vanessa , Souza Danielle G. , Silva Adriana F. , Russo Remo C. , Guabiraba Rodrigo , Pereira Cíntia A. J. , Carvalho Flávia M. , Barsante Michele M. , Correa-Oliveira Rodrigo , Fraga Lúcia A. O. , Negrão-Correa Deborah , Teixeira Mauro M.
Published: March 2005

In human schistosomiasis, the concentrations of the chemokine macrophage inflammatory protein 1α (MIP-1α/CCL3) is greater in the plasma of patients with clinical hepatosplenic disease. The objective of the present study was to confirm the ability of CCL3 to detect severe disease in patients classified by ultrasonography (US) and to evaluate the potential role of CCL3 inSchistosoma mansoni-infected mice. CCL3 was measured by enzyme-linked immunosorbent assay in the plasma ofS. mansoni-infected patients. CCL3-deficient mice were infected with 25 cercariae, and various inflammatory and infectious indices were evaluated. The concentration of CCL3 was higher in the plasma ofS. mansoni-infected than noninfected patients. Moreover, CCL3 was greater in those with US-defined hepatosplenic than with the intestinal form of the disease. In CCL3-deficient mice, the size of the granuloma and the liver eosinophil peroxidase activity and collagen content were diminished compared to wild-type mice. In CCL3-deficient mice, the worm burden after 14 weeks of infection, but not after 9 weeks, was consistently smaller. The in vitro response of mesenteric lymph node cells to antigen stimulation was characterized by lower levels of interleukin-4 (IL-4) and IL-10. CCL3 is a marker of disease severity in infected humans, and experimental studies in mice suggest that CCL3 may be a causative factor in the development of severe schistosomiasis.
Antibody against the Carboxyl Terminus of Intimin α Reduces Enteropathogenic
Escherichia coli
Adherence to Tissue Culture Cells and Subsequent Induction of Actin Polymerization
Authors: Carvalho Humberto M. , Teel Louise D. , Kokai-Kun John F. , O'Brien Alison D.
Published: March 2005

The C-terminal third of intimin binds to its translocated receptor (Tir) to promote attaching and effacing lesion formation during infection with enteropathogenic
Escherichia coli
(EPEC). We observed that the adherence of EPEC strains to HEp-2 cells was reduced and that actin polymerization was blocked by antibody raised against the C-terminal third of intimin α.
Linkage of the Horizontally AcquiredypmandpilGenes inYersinia pseudotuberculosis
Authors: Collyn François , Fukushima Hiroshi , Carnoy Christophe , Simonet Michel , Vincent Pascal
Published: March 2005

The superantigen-encodingypmgene and thepilgene cluster governing type IV pilus biogenesis have been laterally acquired byYersinia pseudotuberculosis.PCR assays on 270 unrelated strains from various environmental and animal sources revealed a significant association ofypmandpilin isolates.
Prevalence and airborne spore levels of Stachybotrys spp. in 200 houses with water incursions in Houston, Texas
Authors: Kuhn Ryan C , Trimble Mingyi W , Hofer Vasanthi , Lee Michael , Nassof Russell S
Published: March 2005

Two hundred homes with a history of water incursion were sampled for fungi to determine the prevalence and airborne spore levels of Stachybotrys spp. Sampling methods included room air, surface, and wall cavity air sampling. Stachybotrys spp. were detected with at least one of the methods in 58.5% of the houses tested, but only 9.6% of the room air samples contained Stachybotrys spores. Aerosolization of Stachybotrys spores was correlated with both wall cavity and surface contamination. However, after adjustment for the surface effect, Stachybotrys spores detected in wall cavities were not a significant factor contributing to spores detected in room air samples. We conclude that Stachybotrys spp. are commonly found on water-damaged building materials. In addition, the observations made in this study suggest that the impact on the living space air is low if the fungal spores are contained within a wall cavity.Key words: Stachybotrys, aerosolized, water-incursion.
The presence of novel 3-hydroxy oxylipins on surfaces of hat-shaped ascospores of Ascoidea africana Batra & Francke-Grosmann
Authors: Bareetseng Andries S , Kock Johan L.F , Pohl Charolina H , Pretorius Elma E , Botes Piet J , Van Wyk Pieter W.J , Nigam Santosh
Published: March 2005

Immunofluorescence microscopy exposed the presence of novel 3-hydroxy oxylipins on the surfaces of aggregated hat-shaped ascospores of Ascoidea africana. These compounds were confirmed by gas chromatography – mass spectrometry analysis. Only the complete structure of a novel 3-hydroxy 10:1 could be determined.Key words: Ascoidea africana, ascospore, 3-hydroxy oxylipins, immunofluorescence microscopy, yeast.
Activité potentielle de méthanogenèse dans les sols, tourbières, sédiments lacustres et du réservoir hydroélectrique Robert-Bourassa dans le moyen Nord-Canadien
Authors: Jugnia Louis-B , Roy Réal , Planas Dolors , Lucotte Marc , Greer Charles W
Published: March 2005

Flooding of land associated with the creation of reservoirs may increase, at least in the short term, methane flux to the atmosphere. To evaluate the potential contribution of such land use on methane production, field samples were studied in vitro for the potential activity of methanogenic bacteria in unflooded or flooded boreal forest soils, together with lacustrine sediments. From this comparative study, periodically flooded or flooded peats contribute more to methane production than do unflooded peats, soils, and natural lake sediment. The intensity and temporal changes in the activity of methanogenic archaea in the different systems depended on a combination of environmental factors, such as the amount and quality of organic carbon, the water level, and the concentration of oxidizing ions (SO42-, Fe3+).Key words: methane production, reservoir, sediment, soils, peats.
On Time Development of a Quasi-Quantum Particle in Quartic Potential (x2-a2)2/2g
Authors: Matsutani Shigeki
Published: March 2005

In this article, I have precisely considered the time development of a quantum particle (of excited states) in the quartic potential (x2-a2)2/2g by means of the semiclassical path integral method. Using the elliptic functions, I have evaluated the tunneling phenomena and the quasi-quantum fluctuation around the quasi-classical paths. I found that the quasi-quantum fluctuation is expressed by the Lamé equation and was exactly solved. Then I have shown that the obtained kernel function is in agreement with exact solutions of the linear potential and the quadratic potential under certain limits as no time-development kernel function of the quartic potential has ever been found which contains the exact solution of the linear and the quadratic potential. It is natural because the classical motion in the quartic potential becomes those of the linear and the quadratic potential under the limits. Thus the obtained time-development kernel function also consists of the energy representation of the Green function of the quartic potential in the semiclassical path integral method given by Carlitz and Nicole (Ann. Phys.164 (1985) 411), which agrees with that of the WKB method in the operator formalism.
ON POSSIBILISTIC AND PROBABILISTIC APPROXIMATIONS OF UNRESTRICTED BELIEF FUNCTIONS BASED ON THE CONCEPT OF FUZZY T-PREORDER
Authors: HERNANDEZ ENRIC , RECASENS JORDI
Published: March 2005

This paper presents a new method for approximating an unrestricted belief measure assuring that the "order" defined by the compatibility degree between evidence and the singletons set is preserved. Our approach, based on the concept of fuzzy T-preorder, also allows us to define several equivalence criteria over the set of all basic probability assignment functions on a given domain. Some others related aspects as uniqueness of the approximations are also addressed.
L-FUZZY PS-COMPACTNESS
Authors: BAI SHI-ZHONG
Published: March 2005

In this paper, the new compactness which is L-fuzzy PS-compactness in L-fuzzy topological spaces is introduced. It is defined for arbitrary L-fuzzy subsets. And some of its characteristic properties and fundamental properties are studied.
A SINISTER VIEW OF DILATION EQUATIONS
Authors: MALONE DAVID
Published: March 2005

We present a technique for studying refinable functions which are compactly supported. Refinable functions satisfy dilation equations and this technique focuses on the implications of the dilation equation at the edges of the support of the refinable function. This method is fruitful, producing new results regarding existence, uniqueness, smoothness and rate of growth of refinable functions.
SCALE-SPACE SEGMENT GROWING FOR HIERARCHICAL DETECTION OF BILIARY TREE STRUCTURE
Authors: LOGESWARAN RAJASVARAN
Published: March 2005

Liver diseases are a common medical problem, especially amongst the population of developing countries. Magnetic Resonance Cholangio Pancreatography (MRCP) has become the popular non-invasive, non-ionizing examination for analysis of the hepatobiliary structure in the liver. Unfortunately, conventional 2D MRCP images can be difficult to analyze for biliary tree anomalies, especially with volume effect, artefacts and noise present in these images, whilst good 3D MRI systems are costly for less affluent nations. This paper proposes a scale-space multi-resolution approach to a segment-based implementation of the popular region growing algorithm, to identify the hierarchical structure of the biliary tree in conventional 2D MRCP images. Results obtained are promising in aiding automatic processing of these images to assist medical practitioners in analyzing the biliary tract more efficiently. Application of the algorithm may be extended for telemedicine.
SUSTAINABLE URBAN DEVELOPMENT: THE FRAMEWORK AND DIRECTORY OF ASSESSMENT METHODS
Authors: DEAKIN MARK , CURWELL STEVE , LOMBARDI PATRIZIA
Published: March 2005

Sustainable development is an issue that has attracted a considerable amount of academic interest since the publication of the Brundtland Report. With Agenda 21, it is an issue which has also found its way into the policy and action programmes of the European Commission. For Europe and its member states, the issue has become one of sustainable urban development and this paper reports on the interim findings of a concerted action programme undertaken to foreground the urban question, develop a framework for the analysis of sustainable development and compile a directory of methods to assess the sustainability of urban development. It classifies the assessment methods in question and goes on to map their applications across the sustainable development issues represented in the framework for analysis. Having done this, the paper goes on to set out how the said methods are being used to build the environmental capacity that is needed for the city of tomorrow to carry its cultural heritage and develop forms of human settlement which are sustainable.
FACTORS AFFECTING WASTE DISPOSAL FACILITIES SITING IN SOUTHERN CHINA
Authors: CHUNG SHAN-SHAN , LO CARLOS W. H. , POON CHI-SUN
Published: March 2005

Solid waste disposal facilities have become scarce in both developed democratic and lower-income socialist states such as the mainland China. The cases of Guangzhou, Jiangmen and Dongguan are analysed to elucidate the factors for siting difficulties and the unique siting style in China. A number of factors are contributing to siting difficulties in Southern China. Irrational applications of the self-sufficient principle at local waste management, poor environmental track records of previous and existing disposal facilities have all severely restricted the supply of waste disposal sites. In addition, rapid increase in waste generation and the use of old-fashioned equipment in waste facilities are speeding up the consumption of landfill space. While the top-down approach is still the norm in waste facility siting, local governments and host communities in China can effectively block the establishment of waste facility as a result of increasing decentralisation of decision making power where even grass root level governments are granted more autonomy in decision making.
Panic Disorder, Phobias, and Generalized Anxiety Disorder
Authors: Craske Michelle G. , Waters Allison M.
Published: March 2005

This chapter provides a review of recent empirical developments, current controversies, and areas in need of further research in relation to factors that are common as well as specific to the etiology and maintenance of panic disorder, phobias, and generalized anxiety disorder. The relative contribution of broad risk factors to these disorders is discussed, including temperament, genetics, biological influences, cognition, and familial variables. In addition, the role that specific learning experiences play in relation to each disorder is reviewed. In an overarching hierarchical model, it is proposed that generalized anxiety disorder, and to some extent panic disorder, loads most heavily on broad underlying factors, whereas specific life history contributes most strongly to circumscribed phobias.
NEURAL NETWORK DYNAMICS
Authors: Vogels Tim P. , Rajan Kanaka , Abbott L.F.
Published: March 2005

Neural network modeling is often concerned with stimulus-driven responses, but most of the activity in the brain is internally generated. Here, we review network models of internally generated activity, focusing on three types of network dynamics: (a) sustained responses to transient stimuli, which provide a model of working memory; (b) oscillatory network activity; and (c) chaotic activity, which models complex patterns of background spiking in cortical and other circuits. We also review propagation of stimulus-driven activity through spontaneously active networks. Exploring these aspects of neural network dynamics is critical for understanding how neural circuits produce cognitive function.
An efficient system for tissue-specific overexpression of transgenes in podocytes in vivo
Authors: Moeller Marcus J. , Soofi Abdulsalam , Sanden Silja , Floege Jürgen , Kriz Wilhelm , Holzman Lawrence B.
Published: March 2005

The utility of promoter fragments isolated from the 5′-flanking region of endogenous mammalian genes to drive transgene expression in vivo is often limited by low expression levels. In this study, a bigenic system was established that allows constitutive overexpression of transgenes in a tissue-specific fashion in transgenic mice in a time- and cost-effective fashion. A modified floxed expression vector was constructed [CMVflox-enhanced green fluorescent protein (eGFP)], in which a lacZ cassette (β-galactosidase) flanked by lox sites was placed between a CMV-promoter and the transgene of interest (eGFP). Before Cre recombination, expression of eGFP was effectively prevented by the interposed floxed lacZ cassette, whereas β-galactosidase was strongly expressed in transiently transfected cells. Transcription of the gene of interest (eGFP) could be irreversibly activated by cotransfection with Cre recombinase. Mice transgenic for CMVflox-eGFP were generated by pronuclear injection. A rapid assay was developed to identify transgenic founders with active transgene expression by measuring transgene activity (β-galactosidase) in tail biopsies. Transgene activity in tails correlated with transgene expression in most other tissues tested including podocytes within the kidney. To activate expression of the gene of interest in a tissue-specific fashion, founder mice were mated to the Cre mouse line 2.5P-Cre previously shown to mediate 100% Cre recombination exclusively in podocytes (Moeller MJ, Sanden SK, Soofi A, Wiggins RC, and Holzman LB. Genesis 35: 39–42, 2003). In doubly transgenic offspring, high-level eGFP expression resulting from Cre excision of the interposed lacZ cassette was detected in four of seven CMVflox-eGFP founder lines. This approach should also circumvent common limitations arising from lethality or transgene silencing as a consequence of transgene overexpression.
Note on weighted Carleman‐type inequality
Authors: Chen Chao-Ping , Cheung Wing-Sum , Qi Feng
Published: March 2005

A double inequality involving the constant e is proved by using an inequality between the logarithmic mean and arithmetic mean. As an application, we generalize the weighted Carleman‐type inequality.
Success of a Smoking Cessation Program among Smoking Relatives of Patients with Serious Smoking-Related Pulmonary Disorders
Authors: Solak Zeynep Aytemur , Göksel Tuncay , Telli Canan Gündüz , Erdinç Ertürk
Published: March 2005

The aim of the study was to investigate the success of a smoking cessation program among the smoking relatives of patients with serious smoking-related disorders and to determine whether having a relative with such a disorder influences the rate of success of the program. The relatives of patients with chronic obstructive pulmonary disease (COPD) and lung cancer who wanted to quit smoking were included in the smoking cessation program (group I, n = 34). During the same period, the same number of subjects with relatives free of any smoking-related diseases were included as a control group (group II, n = 34). Intensive behavioral therapy and motivational support was given to all subjects. Nicotine replacement therapy was administered to 10 subjects (29.4%) in group I and 14 subjects (41.2%) in group II. The subjects were evaluated in the 1st, 2nd, 4th, 8th and 12th week and subsequently every 3 months for a year in the outpatient clinic and proactive telephone interviews were performed periodically. In group I, 23.5% of subjects had a relative with COPD, 61.8% had relatives with lung cancer, and 14.7% had relatives with both COPD and lung cancer. The rate of quitting smoking was 79.4 and 73.5% on the 15th day and 41.2 and 38.2% at the end of the 1st year in groups I and II, respectively (p > 0.05). We observed that having a relative with serious smoking-related disorders did not motivate smokers to quit smoking.
Reliability and Validity of the French Version of the Tobacco Craving Questionnaire
Authors: Berlin Ivan , Vorspan Florence , Singleton Edward G. , Warot Dominique , Notides Christine , Heishman Stephen J.
Published: March 2005

Objectives: (1) To assess the factorial structure, reliability and validity of the French language version of the Tobacco Craving Questionnaire (TCQ), a multidimensional, self-report instrument evaluating tobacco craving, to allow its use in French-speaking populations. (2) To compare the two different language versions of the same instrument in 2 independent samples from 2 cultures in 2 distinct time periods. Methods: The French TCQ was administered to 226 current cigarette smokers after at least 2 h of abstinence. Results: Despite the substantial difference in population characteristics between the French and American samples of smokers, both exploratory and confirmatory factor analyses indicated that the French version was best described by a 4-factor solution, similar to the original English version. Reliability estimates were 0.83, 0.79, 0.69 and 0.66 for the French and 0.82, 0.70, 0.75 and 0.48 for the English version for ‘emotionality’ (factor 1), ‘expectancy’ (factor 2), ‘compulsivity’ (factor 3) and ‘purposefulness’ (factor 4), respectively. The 4 factors accounted for 11.6, 17.1, 9.0, and 9.5% of the total variance in emotionality, expectancy, compulsivity, and purposefulness, respectively, for the French compared to 14.2, 12.5, 14.4 and 5% of the total variance for the English version, respectively. Conclusion: The French version of the TCQ is as valid and reliable instrument as the original English version and assesses the same 4 dimensions of craving for tobacco.