bluuebunny/crossref_metadata_2025 huggingface dataset:
The Presence of Cytokine‐Suppressive CD4+CD25+ T Cells in the Peripheral Blood and Synovial Fluid of Patients with Rheumatoid Arthritis
Authors: Liu M.‐F. , Wang C.‐R. , Fung L.‐L. , Lin L.‐H. , Tsai C.‐N.
Published: September 2005

CD4+CD25+ T cells have been shown to play a regulatory or suppressive role in the immune response and are possibly relevant to the pathogenesis of autoimmune diseases. In the present study, we attempted to investigate the levels of CD4+CD25+ T cells in the peripheral blood (PB) and synovial fluid (SF) of patients with rheumatoid arthritis (RA) and the effects of CD4+CD25+ T cells on the in vitro cytokine production by stimulated SF mononuclear cells (SFMC). The results showed that RA patients had similar frequencies of CD4+CD25+ T cells in PB, expressed as a percentages of the lymphocyte population, as did healthy subjects (mean ± SD: 10.52 ± 5.87% versus 11.11 ± 4.58%., respectively). But in contrast to PB, the SF of RA patients contained significantly higher levels of CD4+CD25+ T cells (17.77 ± 7.92% versus 10.52 ± 5.87%, respectively. P < 0.001). When cocultured in vitro with SFMC, CD4+CD25+ T cells purified from either PB or SF were found to exert a considerable suppressive effect on the production of cytokines including TNF‐α, IFN‐γ and interleukin‐10 (IL‐10). The percentages of inhibition of each cytokines ranged from 41.8 to 98.4% (mean, 80.0%) for TNF‐α, 42.8 to 98.9% (mean, 83.2%) for IFN‐γ and 59.3 to 96.6% (mean, 80.0%) for IL‐10. Because both pro‐inflammatory and anti‐inflammatory cytokines were suppressed by CD4+CD25+ T cells, whether CD4+CD25+ T cells might play a beneficial role in the suppression of sustained inflammation in rheumatoid synovium remains to be elucidated.
The Importance of the Phagocytes' Innate Response in Resolution of the Infection Induced by a Low Virulent Candida albicans Mutant
Authors: Molero G. , Guillén M. V. , Martínez‐Solano L. , Gil C. , Pla J. , Nombela C. , Sánchez‐Pérez M. , Diez‐Orejas R.
Published: September 2005

We have reported that a Candida albicans mkc1Δ/mkc1Δ mutant, deleted in the Mkc1p mitogen‐activated protein kinase, an essential element of the cell integrity signalling pathway, has reduced virulence in a murine model of systemic infection. We analyse here the immunological basis for this feature in view of its failure to vaccinate. Firstly, the influence of the Th response was analysed by infecting different knockout mice, revealing the importance of interferon‐γ in the resolution of mkc1 systemic infection. Secondly, the role of innate immunity was studied. The infection of neutropenic mice revealed that the candidacidal activity of neutrophils is crucial during the first 3 days of infection for the mutant strain. Macrophages played a critical role in the clearance of infection. Although a similar anti‐Candida activity was found for both fungal strains with naïve macrophages, activated macrophages discriminated between both strains. In vitro experiments revealed that the mutant strain displayed a greater susceptibility to nitric oxide (NO), a reduced inhibitory effect on macrophage NO production and an increased capacity of macrophage stimulation by cell wall extracts. The importance of NO in systemic infection with the mutant strain was confirmed by the strong increase in the susceptibility of aminoguanidine (an iNOs inhibitor)‐treated mice.
24‐h Monitoring of Calcineurin Phosphatase Activity in Healthy Subjects
Authors: Koefoed‐Nielsen P. B. , Karamperis N. , Jørgensen K. A.
Published: September 2005

The calcineurin inhibitors cyclosporine and tacrolimus are the cornerstone immunosuppressants used in solid organ transplantation. Studies investigating calcineurin (CaN) activity in renal transplanted patients have been published, but basic properties of the enzyme activity in healthy subjects remain to be described. The aim of this study was to investigate whether CaN displays circadian variation or sex difference is present in healthy subjects. Twenty subjects had blood samples drawn every 4 h for a 24‐h period. CaN activity was determined in whole blood as the release of 32P from a phosphorylated peptide. Activity of the 32P was quantitated by liquid scintillation and results converted to units CaN utilizing a calibration curve. We found no circadian variation in CaN activity and no difference between the two sexes. The clinical importance of these findings is that blood samples for calcineurin activity can be drawn without taking the exact time of day into consideration, but only considering the time of drug intake.
Direct Allorecognition Promotes Activation of Bystander Dendritic Cells and Licenses Them for Th1 Priming: A Functional Link Between Direct and Indirect Allosensitization
Authors: Wallgren A. C. , Andersson B. , Bäcker A. , Karlsson‐Parra A.
Published: September 2005

T‐cell sensitization to indirectly presented alloantigens (indirect pathway of allorecognition) plays a critical role in chronic rejection. The usual very efficient priming of such self‐restricted, T helper type 1 (Th1)‐deviated CD4+ T cells obviously conflicts with the fact that allogeneic MHC molecules are poorly immunogenic per se. The aim of the present study is to elucidate whether direct allosensitization induces production of inflammatory mediators that may affect recruitment and activation of immature bystander (host) dendritic cells (DC). These potential mechanisms were studied in vitro by conducting primary allogeneic mixed leucocyte reactions (MLR), mimicking the priming phase in secondary lymphoid organs, and secondary MLR, mimicking the effector phase within the graft. Primary, and particularly secondary, MLR supernatants were found to contain high levels of monocyte/immature DC‐recruiting CC chemokines and pro‐inflammatory cytokines. Exposure of immature DC to primary or secondary MLR supernatants was found to upregulate CD40 expression and further enhanced lipopolysaccharide‐induced interleukin‐12 (IL‐12) p70 production. Secondary MLR supernatants additionally induced upregulation of CD86 and deviated allogeneic T‐cell responses towards Th1 (enhanced interferon‐γ production without concomitant induction of detectable IL‐4 or IL‐10 production). These findings indicate that direct allorecognition may act as a Th1‐deviating adjuvant for indirect allosensitization.
Distribution of Productive Antigen‐Processing Activity for MHC class II Presentation in Macrophages
Authors: Von Delwig A. , Musson J. A. , Shim H.‐K. , Lee J. J. , Walker N. , Harding C. V. , Williamson E. D. , Robinson J. H.
Published: September 2005

We demonstrated that an epitope from the recombinant protective antigen (rPA) of Bacillus anthracis was presented by mature major histocompatibility complex class II (MHC‐II) molecules, whereas an epitope from the recombinant virulent (rV) antigen of Yersinia pestis was presented by newly synthesized MHC‐II. We addressed which endosomal compartments were involved in the antigen processing of each epitope. Bone‐marrow‐derived macrophages were subjected to subcellular fractionation; fractions were analysed for the expression of endosomal markers and used as a source of enzyme activity for the processing of rPA and rV antigens. The rPA epitope was productively processed by dense lysosomal fractions and light membrane fractions expressing early endosomal markers Rab5 and early endosomal antigen‐1 as well as markers of antigen‐presenting compartments (MHC‐II, DM, DO and Ii chain). In contrast, the rV epitope was productively processed only by dense fractions with lysosomal activity. No productive antigen‐processing activity was associated with fractions of intermediate density expressing Rab7 and Rab9, characteristic of late endosomes. The data suggest that endosomal compartments expressing Rab5 guanosine triphosphatase can productively process protein antigens for presentation by mature MHC class II molecules.
Immunoglobulin G Antibodies Against Environmental Moulds in a Norwegian Healthy Population Shows a Bimodal Distribution for Aspergillus versicolor
Authors: Rydjord B. , Hetland G. , Wiker H. G.
Published: September 2005

Immunoglobulin G (IgG) antibodies against moulds related to indoor dampness problems are used as biomarkers to indicate exposure. In the present study, we evaluated the frequency of mould exposure in an adult healthy population by examining levels of mould‐specific IgG antibodies in Norwegian blood donors. Using enzyme‐linked immunosorbent assay, 106 blood donor sera were analyzed for IgG antibodies to Aspergillus versicolor, Penicillium chrysogenum, Cladosporium herbarum, Stachybotrys chartarum and Fusarium oxysporum. The levels of specific IgG antibodies to P. chrysogenum, C. herbarum and S. chartarum correlated (r = 0.46–0.62). Responses to A. versicolor were considerably stronger than to the other moulds, and another 996 blood donor sera were analyzed for IgG antibodies to this mould. Women had significantly higher levels of specific IgG antibodies to A. versicolor than men. The concentration of A. versicolor‐specific IgG antibodies showed a non‐Gaussian, bimodal distribution profile, in which 12.5% were defined as positive to exposure. This suggests that significant mould exposure in a healthy population can be calculated from mean + 1SD. Western blotting analyses showed that antibody responses to A. versicolor were largely directed against carbohydrate antigens of unknown saccharides.
Caregiver attitudes towards gastrostomy removal after renal transplantation
Authors: Wong Hubert , Mylrea Kyle , Cameron Angela , Manion Ian , Bass Juan , Feber Janusz , Filler Guido
Published: September 2005

Abstract: Gastrostomy tube (G‐tube) removal has been suggested at 3 months following successful renal transplantation (Tx). We noticed a delay in the removal of G‐tubes in our pediatric patients following Tx and therefore conducted a cross‐sectional single center survey on all renal transplant recipients to assess the causes of delayed G‐tube removal. In total, 17 of 23 patients completed the survey, including all patients with G‐tubes (n = 10) and seven patients without G‐tubes. Median age at Tx of gastrostomy patients was significantly lower than that of patients without a G‐tube (median 3.0 yr, range 1.2–4.7 yr vs. median 14 yr, range 6–17 yr, p < 0.0001) and significantly younger than in previous studies on gastrostomies. At the time of the survey, only three of 10 patients had their G‐tube removed at 22, 41 and 61 months after Tx at the ages of 3, 5.5 and 9 yr, respectively. The median age at recent follow up of the remaining seven patients was 4.7 yr (range 2.6–8.75 yr). The most important reason for continued use was fluid intake and medication. Results of our survey showed appropriate concern regarding the risk of prolonged use of the gastrostomy. Caregivers felt that benefits of the gastrostomy in the post‐transplant period outweighed the risks. Caregivers felt pressured towards removal by the physicians. Our findings support the decision to remove gastrostomies based on individual patient needs and total fluid intake rather than a fixed time following successful Tx.
Parents and clinicians underestimate distress and depression in children who had a transplant
Authors: Shemesh Eyal , Annunziato Rachel A. , Shneider Benjamin L , Newcorn Jeffrey H. , Warshaw Jill K. , Dugan Christina A. , Gelb Bruce D. , Kerkar Nanda , Yehuda Rachel , Emre Sukru
Published: September 2005

Abstract:  The present study examined whether there are differences in reporting of depressive and post‐traumatic stress symptoms between children who had a transplant and children who had other medical illnesses. We evaluated both the child's report about her/his symptoms and the parent or the clinician's report about these symptoms in the child. Scores on measures of depression (clinician rated vs. child rated) and post‐traumatic stress (parent rated vs. child rated) were compared between medically ill children who have vs. have not had a solid organ transplant. The findings of a psychiatric evaluation are also reported. Children who have vs. have not received a solid organ transplant reported the same levels of depression and post‐traumatic stress, while adults (their parents or clinicians who evaluated them) reported lower levels of depression and post‐traumatic stress in the transplant group. The psychiatric evaluation revealed no differences between the groups. Children view their post‐transplant course differently from adults caring for these children. Adults tend to underestimate the child's post‐transplant emotional symptoms, possibly because they focus on the improved prognosis (whereas the children focus on the concrete experience of illness). The child's report of his or her emotional symptoms should be directly sought post‐transplant.
Collie eye anomaly in a mixed‐breed dog
Authors: Rampazzo Antonella , D’Angelo Antonio , Capucchio Maria Teresa , Sereno Sandra , Peruccio Claudio
Published: September 2005

A 5‐year‐old, mixed‐breed dog was presented for tetraparesis. Neurologic alterations included a decreased menace response in both eyes. Therefore, an ophthalmic examination was requested. The dog was visual, but menace response, dazzle and pupillary light reflexes were reduced bilaterally. Indirect ophthalmoscopy revealed bilateral optic nerve coloboma and severe choroidal hypoplasia. These lesions closely resembled the ophthalmoscopic features of Collie eye anomaly (CEA). In spite of treatment, the dog's condition worsened and the animal was therefore euthanized. Histology of the globes confirmed severe choroidal hypoplasia and optic disc coloboma in both eyes. The dog was diagnosed to have a lymphoma involving the spinal cord. The two entities were considered not related. As only moderate sight impairment was caused by the posterior segment anomalies, it is by chance that these lesions resembling CEA were found in this mixed‐breed dog.
Anti‐inflammatory effect of germanium‐concentrated yeast against paw oedema is related to the inhibition of arachidonic acid release and prostaglandin E2 production in RBL 2H3 cells
Authors: Lee J. H. , Kim K. W. , Yoon M. Y. , Lee J. Y. , Kim C. J. , Sim S. S.
Published: September 2005

1 To investigate anti‐inflammatory activity of organic germanium, we measured the effect of germanium‐concentrated yeast on arachidonic acid release, prostaglandin E2 (PGE2) production, histamine release, and intracellular H2O2 or hydroperoxide generation in RBL 2H3 cells, and carrageenan‐induced paw oedema in rats.

2 Germanium‐concentrated yeast dose‐dependently inhibited carrageenan‐induced paw oedema, suggesting that germanium‐concentrated yeast has anti‐inflammatory activity in acute inflammation.

3 Germanium‐concentrated yeast significantly inhibited melittin‐induced arachidonic acid release and PGE2 production in RBL 2H3 cells.

4 Germanium‐concentrated yeast did not affect melittin‐induced histamine release and silica‐induced intracellular H2O2 or hydroperoxide generation in RBL 2H3 cells.

5 These results suggest that anti‐inflammatory activity of germanium‐concentrated yeast appears partly to be related to the inhibition of arachidonic acid release and PGE2 production in RBL 2H3 cells.
Chloroethylclonidine reveals that α1A‐adrenoceptors mediate contraction in aorta of α1D‐adrenoceptor knockout mice
Authors: Lázaro‐Suárez M. L. , Gómez‐Zamudio J. H. , Gallardo‐Ortíz I. A. , Tanoue A. , Tsujimoto G. , Farias‐Rodríguez V. M. , Villalobos‐Molina R.
Published: September 2005

1 We have characterized the α1‐adrenoceptor subtypes present in isolated aorta of the α1D‐adrenoceptor knockout (KO) mice, by chloroethylclonidine (CEC)‐induced alkylation and their protection by selective α1‐adrenoceptor antagonists.

2 The α1D‐adrenoceptor is involved in the contractile response to noradrenaline in wild type (WT) mouse aorta.

3 In WT mice 5‐methylurapidil (5‐MU, an α1A‐adrenoceptor antagonist) or BMY 7378 (8‐[2‐[4‐(2‐methoxyphenyl)‐1‐piperazinyl] ethyl]‐8‐azaspiro[4.5] decane‐7,9 dione, a selective α1D‐adrenoceptor antagonist), protected the receptors from CEC‐induced (α1B/D‐adrenoceptor) alkylation, the combination of both antagonists resulted in complete protection, while AH11110A (1‐[biphenyl‐2‐yloxy]‐4‐imino‐4‐piperidin‐1‐yl‐butan‐2‐ol, an α1B‐adrenoceptor antagonist) did not protect.

4 In aorta of KO mice there was a 19‐fold rightward shift in noradrenaline effective concentration (EC50) compared with WT; while 5‐MU alone or in combination with AH11110A protected α1‐adrenoceptors to the same extent.

5 The data indicate that α1A‐adrenoceptors mediate contraction and suggest their role in maintaining homeostasis in the α1D‐adrenoceptors KO mice.
Neuroscience and the Detection of Deception
Authors: Happel Mark D.
Published: September 2005

The detection of deception is among the most important and pressing requirements faced by federal agencies with national security responsibilities. The polygraph is insufficient in its present state of development for meeting the needs of national security. While some neuroscience‐based alternatives to the polygraph have been proposed (e.g., EEG and fMRI), there are significant problems with these techniques and consideration of their operational use is premature. The development of a more effective means for detecting deception will require substantial conceptual advances in the science of deception, in particular the establishment of a sound theoretical basis on which to design such a system. Neuroscience and related fields can make significant contributions toward the development of a theory of deception, given sufficient government support and commitment to such an effort. However, even a sound theory of deception cannot guarantee success; it is vital that the associated policy, legal, and ethical implications of such a system be taken into account.
Preparation of Ultra‐Fine Nickel Manganite Powders and Ceramics by a Solid‐State Coordination Reaction
Authors: Fang Dao‐lai , Wang Zhong‐bing , Yang Ping‐hua , Liu Wei , Chen Chu‐sheng , Winnubst A. J. A.
Published: September 2005

A solid‐state coordination reaction was adopted to prepare negative temperature coefficient ceramics. A mixed oxalate NiMn2(C2O4)3·6H2O, a coordination compound, was synthesized by milling a mixture of nickel acetate, manganese acetate, and oxalic acid for 5 h at room temperature. An ultrafine NiMn2O4 powder was obtained by calcining the mixed oxalate in air at 850°C for 2 h. Ceramics with a relative density of more than 97% were achieved by sintering powder compacts at a temperature as low as 1050°C for 5 h. The specific electrical resistivity ρ25°C and the thermal constant B25°/85°C were 2174 Ω·cm and 3884 K, respectively. The drift of the resistivity after aging at 150°C for 1000 h was 3.0%.
Solid Freeform Fabrication of Permanent Dental Restorations via Slurry Micro‐Extrusion
Authors: Wang Jiwen , Shaw Leon L. , Cameron Thomas B.
Published: September 2005

A solid freeform fabrication procedure for human dental restorations via a slurry micro‐extrusion process is described. A dental porcelain slurry is developed with pseudoplastic property and moderate viscosity, which permits the slurry to be extruded at low extrusion pressure and have good shape‐keeping ability. A green tooth can be produced by this method directly from a CAD digital model in 30 min. The sintering shrinkage of the green tooth is uniform. The microstructure of the sintered tooth is identical to that made via the traditional dental restoration processes. This new dental restoration process presents potential to provide dental patients with better, faster, and less expensive service.
SseJ Deacylase Activity by
Salmonella enterica
Serovar Typhimurium Promotes Virulence in Mice
Authors: Ohlson Maikke B. , Fluhr Kerry , Birmingham Cheryl L. , Brumell John H. , Miller Samuel I.
Published: September 2005

Salmonella enterica
serovar Typhimurium utilizes a type III secretion system (TTSS) encoded on
Salmonella
pathogenicity island-2 (SPI2) to promote intracellular replication during infection, but little is known about the molecular function of SPI2-translocated effectors and how they contribute to this process. SseJ is a SPI2 TTSS effector protein that is homologous to enzymes called glycerophospholipid-cholesterol acyltransferases and, following translocation, localizes to the
Salmonella
-containing vacuole and
Salmonella-
induced filaments. Full virulence requires SseJ, as
sseJ
null mutants exhibit decreased replication in cultured cells and host tissues. This work demonstrates that SseJ is an enzyme with deacylase activity in vitro and identifies three active-site residues. Catalytic SseJ mutants display wild-type translocation and subcellular localization but fail to complement the virulence defect of an
sseJ
null mutant. In contrast to the wild type, SseJ catalytic mutants fail to down regulate
Salmonella
-induced filament formation and fail to restore the
sifA
null mutant phenotype of loss of phagosomal membrane to
sifA sseJ
null double mutants, suggesting that wild-type SseJ modifies the vacuolar membrane. This is the first demonstration of an enzymatic activity for a SPI2 effector protein and provides support for the hypothesis that the deacylation of lipids on the
Salmonella
-containing vacuole membrane is important to bacterial pathogenesis.
Identification of New Secreted Effectors in
Salmonella enterica
Serovar Typhimurium
Authors: Geddes Kaoru , Worley Micah , Niemann George , Heffron Fred
Published: September 2005

A common theme in bacterial pathogenesis is the secretion of bacterial products that modify cellular functions to overcome host defenses. Gram-negative bacterial pathogens use type III secretion systems (TTSSs) to inject effector proteins into host cells. The genes encoding the structural components of the type III secretion apparatus are conserved among bacterial species and can be identified by sequence homology. In contrast, the sequences of secreted effector proteins are less conserved and are therefore difficult to identify. A strategy was developed to identify virulence factors secreted by
Salmonella enterica
serovar Typhimurium into the host cell cytoplasm. We constructed a transposon, which we refer to as mini-Tn
5
-cycler, to generate translational fusions between
Salmonella
chromosomal genes and a fragment of the calmodulin-dependent adenylate cyclase gene derived from
Bordetella pertussis
(
cyaA
′). In-frame fusions to bacterial proteins that are secreted into the eukaryotic cell cytoplasm were identified by high levels of cyclic AMP in infected cells. The assay was sufficiently sensitive that a single secreted fusion could be identified among several hundred that were not secreted. This approach identified three new effectors as well as seven that have been previously characterized. A deletion of one of the new effectors,
steA
(
Salmonella
translocated effector A), attenuated virulence. In addition, SteA localizes to the
trans
-Golgi network in both transfected and infected cells. This approach has identified new secreted effector proteins in
Salmonella
and will likely be useful for other organisms, even those in which genetic manipulation is more difficult.
Live Nonpathogenic Parasitic Vector as a Candidate Vaccine against Visceral Leishmaniasis
Authors: Breton Marie , Tremblay Michel J , Ouellette Marc , Papadopoulou Barbara
Published: September 2005

To date, there are no proven vaccines against any form of leishmaniasis. The development of live attenuated vectors shows promise in the field ofLeishmaniavaccination because these organisms mimic more effectively the course of real infections and can elicit potent activation of the immune system. In the present study, we investigated the potential of a parasitic protozoan that is nonpathogenic to humans,Leishmania tarentolae, as a live candidate vaccine that efficiently targets dendritic cells and lymphoid organs, thus enhancing antigen presentation and consequently influencing the magnitude and quality of T-cell immune responses. We demonstrated thatL. tarentolaeactivates the dendritic cell maturation process and induces T-cell proliferation and the production of gamma interferon, thus skewing CD4+T cells toward a Th1 cell phenotype. More importantly, we found that a single intraperitoneal injection ofL. tarentolaecould elicit a protective immune response against infectious challenge withLeishmania donovaniin susceptible BALB/c mice. These results suggest that the use ofL. tarentolaeas a live vaccine vector may represent a promising approach for improving the effectiveness and safety of candidate live vaccines againstLeishmaniainfections and possibly other intracellular pathogens for which T-cell mediated responses are critical for the development of protective immunity.
Anti-Idiotypic Antibody as a Potential Candidate Vaccine forNeisseria meningitidisSerogroup B
Authors: Park In Ho , Youn Ju Ho , Choi In-Hong , Nahm Moon H. , Kim Se Jong , Shin Jeon-Soo
Published: September 2005

Sepsis and meningitis caused byNeisseria meningitidisserogroup B (NMGB) are serious diseases in infants and young adults, but no effective vaccine is available. The capsular polysaccharide (PS) of NMGB has poor immunogenicity and a structural similarity to polysialic acid (PSA) on neuronal tissue that may elicit autoantibodies. Using HmenB3, a protective and nonautoreactive monoclonal antibody (MAb) to NMGB capsular PS, we produced an anti-idiotypic MAb, Naid60, which mimics the capsular PS of NMGB. We produced an anti-anti-idiotypic MAb, MoB34, by using the immunogenic site on Naid60 responsible for inducing the anti-NMGB PS antibody response. MoB34 elicited the complement-mediated killing of representative strains of serogroup B meningococci. MoB34 did not bind to CHP-134, a neuroblastoma cell line expressing α(2-8) PSA, or to mouse brain cryosections at a high concentration. Naid60-keyhole limpet hemocyanin immunization inhibited the growth of live NMGB in intraperitoneally challenged mice; in contrast, three of five control mice developed bacteremia. Thus, Naid60 has an immunogenic site that elicits antibodies with bactericidal activity against NMGB and no autoimmunity to PSA. We suggest that the immunogenic region of Naid60 is a candidate for the development of a new vaccine against NMGB.
Comparative Genomic Analysis ofChlamydia trachomatisOculotropic and Genitotropic Strains
Authors: Carlson John H. , Porcella Stephen F. , McClarty Grant , Caldwell Harlan D.
Published: September 2005

Chlamydia trachomatisinfection is an important cause of preventable blindness and sexually transmitted disease (STD) in humans.C. trachomatisexists as multiple serovariants that exhibit distinct organotropism for the eye or urogenital tract. We previously reported tissue-tropic correlations with the presence or absence of a functional tryptophan synthase and a putative GTPase-inactivating domain of the chlamydial toxin gene. This suggested that these genes may be the primary factors responsible for chlamydial disease organotropism. To test this hypothesis, the genome of an oculotropic trachoma isolate (A/HAR-13) was sequenced and compared to the genome of a genitotropic (D/UW-3) isolate. Remarkably, the genomes share 99.6% identity, supporting the conclusion that a functional tryptophan synthase enzyme and toxin might be the principal virulence factors underlying disease organotropism. Tarp (translocated actin-recruiting phosphoprotein) was identified to have variable numbers of repeat units within the N and C portions of the protein. A correlation exists between lymphogranuloma venereum serovars and the number of N-terminal repeats. Single-nucleotide polymorphism (SNP) analysis between the two genomes highlighted the minimal genetic variation. A disproportionate number of SNPs were observed within some members of the polymorphic membrane protein (pmp) autotransporter gene family that corresponded to predicted T-cell epitopes that bind HLA class I and II alleles. These results implicate Pmps as novel immune targets, which could advance future chlamydial vaccine strategies. Lastly, a novel target for PCR diagnostics was discovered that can discriminate between ocular and genital strains. This discovery will enhance epidemiological investigations in nations where both trachoma and chlamydial STD are endemic.
Role of an Alginate Lyase for Alginate Transport in Mucoid
Pseudomonas aeruginosa
Authors: Jain Sumita , Ohman Dennis E.
Published: September 2005

The opportunistic pathogen
Pseudomonas aeruginosa
secretes a capsule-like polysaccharide called alginate that is important for evasion of host defenses, especially during chronic pulmonary disease of patients with cystic fibrosis (CF). Most proteins for alginate biosynthesis are encoded by the 12-gene
algD
operon. Interestingly, this operon also encodes AlgL, a lyase that degrades alginate. Mutants lacking AlgG, AlgK, or AlgX, also encoded by the operon, synthesize alginate polymers that are digested by the coregulated protein AlgL. We examined the phenotype of an Δ
algL
mutation in the highly mucoid CF isolate FRD1. Generating a true Δ
algL
mutant was possible only when the
algD
operon was under the control of a LacI
q
-repressed
trc
promoter. Upon induction of alginate production with isopropyl-β-
d
-thiogalactopyranoside, the Δ
algL
mutant cells were lysed within a few hours. Electron micrographs of the Δ
algL
mutant showed that alginate polymers accumulated in the periplasm, which ultimately burst the bacterial cell wall. The requirement of AlgL in an alginate-overproducing strain led to a new model for alginate secretion in which a multiprotein secretion complex (or scaffold, that includes AlgG, AlgK, AlgX, and AlgL) guides new polymers through the periplasm for secretion across the outer membrane. In this model, AlgL is bifunctional with a structural role in the scaffold and a role in degrading free alginate polymers in the periplasm.
The Chemokine CCL2 Is Required for Control of Murine GastricSalmonella entericaInfection
Authors: DePaolo R. William , Lathan Rashida , Rollins Barrett J. , Karpus William J.
Published: September 2005

Salmonella entericais a gram-negative intracellular pathogen that can cause a variety of diseases ranging from gastroenteritis to typhoid fever. The Typhimurium serotype causes gastroenteritis in humans; however, infection of mice results in an enteric fever that resembles human typhoid fever and has been used as a model for typhoid fever. The present study examined the role of the chemokine CCL2 in the control ofSalmonellainfection. Upon infection with salmonellae, mucosal expression of CCL2 is rapidly up-regulated, followed by systemic expression in the spleen. CCL2−/−mice became moribund earlier and had a higher rate of mortality compared to wild-type C57BL/6 mice. Moreover, CCL2−/−mice had significantly higher levels of bacteria in the liver compared to wild-type controls. Mucosal and serum interleukin-6 and tumor necrosis factor alpha levels were elevated in CCL2−/−mice compared to wild-type mice. In vitro analysis demonstrated that CCL2−/−macrophages infected with salmonellae resulted in dysregulated cytokine production compared to macrophages derived from wild-type mice. These data are the first to directly demonstrate CCL2 as a critical factor for immune responses and survival followingS. entericainfection.
Disruption of a Locus Encoding a Nucleolar Zinc Finger Protein Decreases Tachyzoite-to-Bradyzoite Differentiation in
Toxoplasma gondii
Authors: Vanchinathan Padmini , Brewer Jeremy L. , Harb Omar S. , Boothroyd John C. , Singh Upinder
Published: September 2005

During its life cycle in intermediate hosts,
Toxoplasma gondii
exists in two interconverting developmental stages: tachyzoites and bradyzoites. This interconversion is essential for the survival and pathogenicity of the parasite, but little is known about the genetic mechanisms that control this process. We have previously generated tachyzoite-to-bradyzoite differentiation (Tbd
−
) mutants using chemical mutagenesis and a green fluorescent protein-based selection strategy. The genetic loci responsible for the Tbd
−
phenotype, however, could not be identified. We have now used an insertional mutagenesis strategy to generate two differentiation mutants: TBD-5 and TBD-6 that switch to bradyzoites at 10 and 50% of wild-type levels, respectively. In TBD-6 there is a single insertion of the mutagenesis vector 164 bp upstream of the transcription start site of a gene encoding a zinc finger protein (
ZFP
1). Disruption of this locus in wild-type parasites reproduces the decreased stage conversion phenotype. ZFP1 is targeted to the parasite nucleolus by CCHC motifs and significantly altered expression levels are toxic to the parasites. This represents the first identification of a gene necessary for efficient conversion of tachyzoites to bradyzoites.
Comparative Transcriptional Profiling ofBorrelia burgdorferiClinical Isolates Differing in Capacities for Hematogenous Dissemination
Authors: Ojaimi Caroline , Mulay Vishwaroop , Liveris Dionysios , Iyer Radha , Schwartz Ira
Published: September 2005

Borrelia burgdorferi, the etiologic agent of Lyme disease, is genetically heterogeneous. Previous studies have shown a significant association between the frequency of hematogenous dissemination in Lyme disease patients and the genotype of the infectingB. burgdorferistrain. Comparative transcriptional profiling of two representative clinical isolates with distinct genotypes (BL206 and B356) was undertaken. A total of 78 open reading frames (ORFs) had expression levels that differed significantly between the two isolates. A number of genes with potential involvement in nutrient uptake (BB0603, BBA74, BB0329, BB0330, and BBB29) have significantly higher expression levels in isolate B356. Moreover, nearly 25% of the differentially expressed genes are predicted to be localized on the cell surface, implying that these two isolates have cell surface properties that differ considerably. One of these genes, BBA74, encodes a protein of 257 amino acid residues that has been shown to possess porin activity. BBA74 transcript level was >20-fold higher in B356 than in BL206, and strain B356 contained three- to fivefold more BBA74 protein. BBA74 was disrupted by the insertion of a kanamycin resistance cassette into the coding region. The growth rates of both wild-type and mutant strains were essentially identical, and cultures reached the same final cell densities. However, the mutant strains consistently showed prolonged lags of 2 to 5 days prior to the induction of log-phase growth compared to wild-type strains. It is tempting to speculate that the absence of BBA74 interferes with the enhanced nutrient uptake that may be required for the entry of cells into log-phase growth. These studies demonstrate the value of comparative transcriptional profiling for identifying differences in the transcriptomes ofB. burgdorfericlinical isolates that may provide clues to pathogenesis. The 78 ORFs identified here are a good starting point for the investigation of factors involved in the hematogenous dissemination ofB. burgdorferi.
Nasal Colonization with
Streptococcus pneumoniae
Includes Subpopulations of Surface and Invasive Pneumococci
Authors: Briles David E. , Novak Lea , Hotomi Muneki , van Ginkel Frederik W. , King Janice
Published: September 2005

We demonstrated that during colonization with
Streptococcus pneumoniae
the nasal mucosal tissues of mice support two populations of pneumococci. Transparent-phase pneumococci can be readily washed from the outer surface, while a second population composed of primarily opaque-phase pneumococci is released only by homogenization of the nasal tissue. The fact that the opaque phase has previously been associated with invasion and the fact that opaque-phase pneumococci were released by homogenization of previously washed nasal tissue suggest that the opaque-phase pneumococci may have invaded the nasal tissue. Consistent with this hypothesis was our observation that there was inflammation in portions of the nasal mucosa of the colonized mice but not in the mucosa of noncolonized mice, but this observation did not prove the hypothesis. If the opaque-phase pneumococci released from the nasal tissue were from within the tissue and/or if resistance of the opaque-phase subpopulation to antibody, complement, and phagocytes is essential for long-term carriage, it seems likely that the virulence factors of
S. pneumoniae
that are necessary for killing humans exist to facilitate carriage. Although this speculation is unproven, the observation that there are separate populations of pneumococci during colonization may help guide future attempts to understand the biology of nasal colonization by this pathogen.
Expression of Matrix Metalloproteinases Subsequent to UrogenitalChlamydia muridarumInfection of Mice
Authors: Ramsey K.H. , Sigar I.M. , Schripsema J. H. , Shaba N. , Cohoon K. P.
Published: September 2005

The central hypothesis of this study was that matrix metalloproteinases (MMPs) would be enhanced following murine chlamydial infection and that their expression would vary in mouse strains that differ in their susceptibility to chronic chlamydia-induced disease. To address this hypothesis, female C3H/HeN and C57BL/6 mice were infected intravaginally withChlamydia muridarum. Uterine and oviduct tissues were assessed for transcription of MMP genes and their tissue inhibitors. An increased activity of MMP genes relative to preinfection tissues was observed in the C3H/HeN mice when compared to C57BL/6 mice. Using gelatin zymography, we detected constitutive MMP-2 activity in both strains of mice but an increase in MMP-9. Casein zymography indicated the presence of two elastase-like activities consistent with MMP-12 and possibly MMP-7. Western blotting and antigen capture enzyme-linked immunoassay also confirmed an increase in MMP-9 but constitutive MMP-2 expression subsequent to the infection in both strains of mice. In C57BL/6 mice, MMP-9 was present in monomer and dimer form throughout the 56-day monitoring period. C3H/HeN mice produced dimeric MMP-9, but increases in the monomer form were also observed through day 14. Post-translational modification of MMP-9 between the two strains also differed. Immunohistochemistry revealed neutrophils as a prominent source for MMP-9 in both strains of mice. We conclude that differences in the relative expression and activity of MMPs, particularly MMP-9, occur in mice differing in their susceptibility to the development of chronic chlamydial disease. These differences may account for disparate outcomes with regard to chronic sequelae of the disease.
Toll-Like Receptor 2 Regulates Interleukin-1β-Dependent Cardiomyocyte Hypertrophy Triggered by
Trypanosoma cruzi
Authors: Petersen Christine A. , Krumholz Katherine A. , Burleigh Barbara A.
Published: September 2005

Trypanosoma cruzi
, the intracellular protozoan parasite that causes Chagasic cardiomyopathy, elicits a robust hypertrophic response in isolated cardiomyocytes. Previous studies established that
T. cruzi
-elicited cardiomyocyte hypertrophy is mediated by interleukin-1β produced by infected cardiomyocyte cultures. Here, we define key upstream signaling events leading to cardiomyocyte hypertrophy in response to
T. cruzi
infection, to be dependent on Toll-like receptor 2 and NF-κB. Furthermore, we demonstrate that cardiomyocyte hypertrophy, which is initiated by live infective
T. cruzi
trypomastigotes or stimulation of isolated myocytes with secreted/released trypomastigote molecules, is a common outcome of the cardiomyocyte recognition of pathogen-associated molecular patterns by intrinsic Toll-like receptors. This study is the first to link pathogen recognition by intrinsic Toll-like receptors to cardiomyocyte hypertrophy.
A CLASS OF EVOLUTIONARY VARIATIONAL INEQUALITIES WITH APPLICATIONS IN VISCOELASTICITY
Authors: BARBOTEU M. , FERNÁNDEZ J. R. , HOARAU-MANTEL T.-V.
Published: September 2005

We consider a class of abstract evolutionary variational inequalities arising in the study of contact problems for viscoelastic materials. We prove an existence and uniqueness result, using arguments of nonlinear evolutionary equations and Banach's fixed point theorem. We then consider the numerical approximation of the problem. By introducing a fully discrete scheme we show the existence of a unique solution and derive error estimates on the approximate solutions, which represent the main results of the work. We apply the abstract results in the study of two contact problems involving viscoelastic materials. The first one is a Signorini frictionless problem for Kelvin–Voigt materials and the second one is a frictional contact problem for linear Maxwell materials. We provide the variational and numerical analysis of the first problem including error estimates and numerical simulations and we prove the unique weak solvability of the second problem.
OPTIMAL CONTROL THEORY APPLIED TO A DIFFERENCE EQUATION MODEL FOR CARDIOPULMONARY RESUSCITATION
Authors: JUNG EUNOK , LENHART SUZANNE , PROTOPOPESCU VLADIMIR , BABBS CHARLES F.
Published: September 2005

The techniques of optimal control are applied to a validated blood circulation model of cardiopulmonary resuscitation (CPR), consisting of a system of seven difference equations. In this system, the nonhomogeneous forcing term is the externally applied chest pressure acting as the "control". We seek to maximize the blood flow, as measured by the pressure differences between the thoracic aorta and the superior vena cava. The new aspect in this application is that the control values from the two previous time steps are used to calculate the pressures (state variables) at the current time step. We prove the existence and uniqueness of the optimal control and provide a new CPR strategy, with increased blood flow. The characterization of the optimal control is given in terms of the solutions of the circulation model and of the corresponding adjoint system. The numerical results show a significant increase in the blood flow as compared with standard CPR.
MICROMAGNETICS OF THIN SHELLS
Authors: SLASTIKOV VALERIY
Published: September 2005

We study a thin-shell limit of micromagnetic energy for soft small ferromagnets. The relations between thickness of the magnet t, diameter l and magnetic exchange length w are t/l → 0 and tl/w2 ≲ 1. We prove a Γ-convergence of the original 3D problem to a nonlocal 2D problem.
LOW-FREQUENCY ACOUSTIC SCATTERING BY AN INHOMOGENEOUS MEDIUM
Authors: VENKOV GEORGE
Published: September 2005

This paper deals with the scattering of time-harmonic acoustic waves by inhomogeneous medium. We study the problem to recover the near and the far field using a priori information about the refractive index and the support of inhomogeneity. The incident spherical wave is modified in such a way as to recover the plane wave incidence when the source point approaches infinity. Applying the low-frequency expansions, the scattering medium problem is reduced to a sequence of potential problems for the approximation coefficients in the presence of a monopole singularity located at the source of incidence. Complete expansions for the integral representation formula in the near field as well as for the scattering amplitude in the far field are provided. The method is applied to the case of a spherical region of inhomogeneity and a radial dependent refractive index. As the point singularity tends to infinity, the relative results recover the scattering medium problem for plane wave incidence.
NEW FICTITIOUS DOMAIN METHODS: FORMULATION AND ANALYSIS
Authors: BABUŠKA IVO , PODNOS EUGENE G. , RODIN GREGORY J.
Published: September 2005

Two closely-related fictitious domain methods for solving problems involving multiple interfaces are introduced. Like other fictitious domain methods, the proposed methods simplify the task of finite element mesh generation and provide access to solvers that can take advantage of uniform structured grids. The proposed methods do not involve the Lagrange multipliers, which makes them quite different from existing fictitious domain methods. This difference leads to an advantageous form of the inf–sup condition, and allows one to avoid time-consuming integration over curvilinear surfaces. In principle, the proposed methods have the same rate of convergence as existing fictitious domain methods. Nevertheless it is shown that, at the cost of introducing additional unknowns, one can improve the quality of the solution near the interfaces. The methods are presented using a two-dimensional model problem formulated in the context of linearized theory of elasticity. The model problem is sufficient for presenting method details and mathematical foundations. Although the model problem is formulated in two dimensions and involves only one interface, there are no apparent conceptual difficulties to extending the methods to three dimensions and multiple interfaces. Further, it is possible to extend the methods to nonlinear problems involving multiple interfaces.
MATING SYSTEMS OF BLOOD-FEEDING FLIES
Authors: Yuval Boaz
Published: September 2005

▪ Abstract  The mating system of each species is a unique, dynamic suite of interactions between the sexes. In this review I describe these interactions in the families of flies that contain blood-feeding species. A transition from the aerial swarm, with rapid copulae and no direct female choice, to substrate-based systems with lengthy copulae and opportunities for female choice is evident at both a phylogenetic scale and within nematoceran families under specific ecological conditions. Female monogamy is associated with the former, polyandry with the latter. I suggest that the intensity of sexual selection operating on males in systems where the probability of mating is low has favored male ability to control female receptivity. Reproductive success of males is universally correlated to successful foraging for sugar or blood and (in some species and ecological conditions) to body size. Understanding the ecological basis of the mating systems of these flies will help formulate integrative, sustainable, and biologically lucid approaches for their control.
Proinflammatory cytokines inhibit human placental 11β-hydroxysteroid dehydrogenase type 2 activity through Ca2+and cAMP pathways
Authors: Kossintseva Iren , Wong Susan , Johnstone Ed , Guilbert Larry , Olson David M. , Mitchell B. F.
Published: September 2005

Excessive fetal exposure to glucocorticoids has been implicated in the etiology of adult metabolic and cardiovascular disease. Placental 11β-hydroxysteroid dehydrogenase type 2 (11β-HSD2) may protect the fetus from excessive glucocorticoid exposure. Maternal stress may be accompanied by elevated levels of cortisol and increased proinflammatory cytokines [interleukin (IL)-1β, IL-6, and tumor necrosis factor-α (TNF-α)]. We hypothesize that proinflammatory cytokines inhibit human placental 11β-HSD activity. We incubated explant cultures of term human placental villi in the presence or absence of 10 ng/ml IL-1β, IL-6, or TNF-α, with or without agonists or antagonists of intracellular Ca2+and adenylyl cyclase. Activity for 11β-HSD2 was estimated using a radioisotope assay, and mRNA was measured using quantitative RT-PCR. All cytokines significantly ( P ≤ 0.05) reduced 11β-HSD2 activity (>75% suppression); maximal inhibition occurred within 2 h and was maintained for at least 24 h. The IL-1β-induced inhibitory activity was attenuated using a Ca2+channel blocker (nifedipine), an intracellular Ca2+antagonist [8-( N, N-diethylamino)octyl-3,4,5-trimethoxybenzoate], or the adenylyl cyclase stimulant forskolin. Conversely, 11β-HSD2 activity was diminished in the presence of the Ca2+ionophore A-23187 or the adenylyl cyclase inhibitor SQ-22536. mRNA levels for 11β-HSD2 were not changed by any of the treatments. Proinflammatory cytokines inhibit human placental 11β-HSD2 activity through a mechanism that involves increased intracellular Ca2+and inhibition of adenylyl cyclase. This could result in excessive fetal exposure to maternal cortisol. This mechanism might mediate part of the increased risk of metabolic and cardiovascular disease in adult offspring.