bluuebunny/crossref_metadata_2025_split huggingface dataset:
Biofilm Growth Increases Phosphorylcholine Content and Decreases Potency of NontypeableHaemophilus influenzaeEndotoxins
Authors: West-Barnette Shayla , Rockel Andrea , Swords W. Edward 
Published: February 2006

ABSTRACTNontypeableHaemophilus influenzae(NTHI) is a common respiratory commensal and opportunistic pathogen. NTHI is normally contained within the airways by host innate defenses that include recognition of bacterial endotoxins by Toll-like receptor 4 (TLR4). NTHI produces lipooligosaccharide (LOS) endotoxins which lack polymeric O side chains and which may contain host glycolipids. We recently showed that NTHI biofilms contain variants with sialylated LOS glycoforms that are essential to biofilm formation. In this study, we show that NTHI forms biofilms on epithelial cell layers. Confocal analysis revealed that sialylated variants were distributed throughout the biofilm, while variants expressing phosphorylcholine (PCho) were found within the biofilm. Consistent with this observation,PCho content of LOS purified from NTHI biofilms was increased compared to LOS from planktonic cultures. Hypothesizing that the observed changes in endotoxin composition could affect bioactivity, we compared inflammatory responses to NTHI LOS purified from biofilm and planktonic cultures. Our results show that endotoxins from biofilms induced weaker host innate responses. While we observed a minimal effect of sialylation on LOS bioactivity, there was a significant decrease in bioactivity associated withPCho substitutions. We thus conclude that biofilm growth increases the proportion ofPCho+variants in an NTHI population, resulting in a net decrease in LOS bioactivity. Thus, in addition to their well-documented resistance phenotypes, our data show that biofilm communities of NTHI bacteria contain variants that evoke less potent host responses.
Role of Tumor Necrosis Factor Alpha (TNF-α) and Interleukin-10 in the Pathogenesis of Severe Murine Monocytotropic Ehrlichiosis: Increased Resistance of TNF Receptor p55- and p75-Deficient Mice to Fatal Ehrlichial Infection
Authors: Ismail Nahed , Stevenson Heather L. , Walker David H. 
Published: February 2006

ABSTRACTIntraperitoneal (i.p.) infection with a high dose of a highly virulentEhrlichiastrain (IOE) results in a toxic shock-like syndrome characterized by severe liver injury and systemic overproduction of tumor necrosis factor alpha (TNF-α) by CD8+T cells. We examined the role of TNF-α and TNF receptors in high-dose-IOE-induced shock/liver injury. TNF receptor (TNFR) I/II−/−mice lacking both the p55 and p75 receptors for this cytokine were more resistant to IOE-induced liver injury than their wild-type background controls. TNFR I/II−/−mice survived longer, dying between 15 and 18 days, with evidence of mild liver necrosis/apoptosis. In contrast, wild-type mice were not rescued from the lethal effect of IOE by TNF-α neutralization. TNF-α-depleted mice developed severe liver injury and succumbed to disease between days 9 and 11 postinfection, similar to sham-treated, infected wild-type mice. Although IFN-γ production in the spleens of IOE-infected TNFR I/II−/−and TNF-α-depleted mice was higher than that detected in wild-type controls, these mice had higher bacterial burdens than infected controls. Following high-dose IOE challenge, TNFR I/II−/−and TNF-α-depleted mice have an early increase in IL-10 levels in sera and spleens, which was produced mainly by adherent spleen cells. In contrast, a late burst of interleukin-10 (IL-10) was observed in control mice. Nonadherent spleen cells were the major source of IL-10 in IOE-infected wild-type mice. We conclude that TNFR I/II and TNF-α participate inEhrlichia-induced shock and host defense by regulating liver injury and controlling ehrlichial burden. Our data suggest that fatal ehrlichiosis could be a multistep process, where TNF-α is not solely responsible for mortality.
Two Monoclonal Antibodies with Defined Epitopes of P44 Major Surface Proteins NeutralizeAnaplasma phagocytophilumby Distinct Mechanisms
Authors: Wang Xueqi , Kikuchi Takane , Rikihisa Yasuko 
Published: February 2006

ABSTRACTAnaplasma phagocytophilumis an obligatory intracellular bacterium that causes human granulocytic anaplasmosis. The polymorphic 44-kDa major outer membrane proteins ofA. phagocytophilumare dominant antigens recognized by patients and infected animals. However, the ability of anti-P44 antibody to neutralize the infection has been unclear due to a mixture of P44 proteins with diverse hypervariable region amino acid sequences expressed by a given bacterial population and lack of epitope-defined antibodies. Monoclonal antibodies (MAbs) 5C11 and 3E65 are directed to different domains of P44 proteins, the N-terminal conserved region and P44-18 central hypervariable region, respectively. Passive immunization with either MAb 5C11 or 3E65 partially protects mice from infection withA. phagocytophilum. In the present study, we demonstrated that the two monoclonal antibodies recognize bacterial surface-exposed epitopes of naturally folded P44 proteins and mapped these epitopes to specific peptide sequences. The two MAbs almost completely blocked the infection of theA. phagocytophilumpopulation that predominantly expressed P44-18 in HL-60 cells by distinct mechanisms: MAb 5C11 blocked the binding, but MAb 3E65 did not block binding or internalization. Instead, MAb 3E65 inhibited internalizedA. phagocytophilumto develop into microcolonies called morulae. Some plasma from experimentally infected horses and mice reacted with these two epitopes. Taken together, these data indicate the presence of at least two distinct bacterial surface-exposed neutralization epitopes in P44 proteins. The results indicate that antibodies directed to certain epitopes of P44 proteins have a critical role in inhibitingA. phagocytophiluminfection of host cells.
Hypophysectomy and Neurointermediate Pituitary Lobectomy Reduce Serum Immunoglobulin M (IgM) and IgG and Intestinal IgA Responses toSalmonella entericaSerovar Typhimurium Infection in Rats
Authors: Campos-Rodríguez Rafael , Quintanar-Stephano Andrés , Jarillo-Luna Rosa Adriana , Oliver-Aguillón Gabriela , Ventura-Juárez Javier , Rivera-Aguilar Victor , Berczi Istvan , Kovacs Kalman 
Published: February 2006

ABSTRACTThe influence of anterior pituitary hormones on the gastrointestinal tract of humans and animals has been reported. Hypophysectomy (HYPOX) in the rat causes atrophy of the intestinal mucosa, reduction of gastric secretion and intestinal absorption, and increased susceptibility to infections. To our knowledge, there are no studies on the humoral immune response of the gut-associated lymphoid tissue after HYPOX. We have reported that decreased secretion of vasopressin and oxytocin due to neurointermediate pituitary lobectomy (NIL) diminishes humoral and cell-mediated immune responses. However, no data have been published on whether NIL can affect intestinal immune responses. We analyzed the effects of HYPOX and NIL on bacterial colonization of the intestinal lumen, Peyer's patches, and spleen as well as the serum immunoglobulin G (IgG) and IgM and specific intestinal IgA levels in response toSalmonella entericaserovar Typhimurium oral infection. Results showed the following: (i)Salmonellaserovar Typhimurium was eliminated from the intestinal lumen at the same rate in rats that underwent a sham operation, HYPOX, and NIL; (ii)Salmonellaserovar Typhimurium colonization of Peyer's patches and spleen was significantly higher in both HYPOX and NIL rats than in sham-operated rats; (iii) serum IgG and IgM and intestinal IgA against surface proteins ofSalmonellaserovar Typhimurium were significantly lower in HYPOX and NIL rats than in sham-operated rats; and (iv) compared to NIL rats, higher Peyer's patch and spleen bacterial colonization and decreased IgG, IgM, and IgA production were observed in HYPOX rats. We conclude that hormones from each pituitary lobe affect the systemic and gastrointestinal humoral immune responses through different mechanisms.
Pneumococcal Polysaccharides Interact with Human Dendritic Cells
Authors: Meltzer Ulrike , Goldblatt David 
Published: February 2006

ABSTRACT

Dendritic cells (DCs) are critical antigen presentation cells whose influence on murine immune responses to polysaccharide antigens has only recently been elucidated. Little is known about human DC-polysaccharide interactions. We set out to study the interaction between human monocyte-derived DCs and pneumococcal capsular polysaccharides (PPS) in vitro. Immature DCs were generated from peripheral blood monocytes and incubated with fluorescein isothiocyanate-labeled PPS type 9N or 14 for assessment of uptake. DCs were exposed to PPS type 1, 6B, 9N, 14, 19F, or 23F in the absence or presence of
Escherichia coli
lipopolysaccharide (LPS) for assessment of phenotypic DC maturation and cytokine production. PPS were taken up by immature DCs and proceeded to HLA-DR
+
and lysosome-associated membrane protein-1
+
late endosomal compartments. Uptake was reduced in the presence of cytochalasin D and wortmannin, suggesting that both cytoskeletal rearrangements and phosphatidylinositol 3-kinase activation may be required for internalization. None of the PPS tested induced DC phenotype changes, maturation, or interleukin-12 (IL-12)/IL-10 production. However, PPS were capable of modulating the response of the DCs to a second signal such as LPS. Exposure of DCs to PPS in the presence of LPS resulted in an altered cytokine balance with significantly increased IL-10 production and reduced IL-12 production compared to LPS alone. This effect was not seen using the control antigen tetanus toxoid. DC-pneumococcus interaction may affect subsequent immune responses to pneumococci, as an altered cytokine balance may have a profound effect on DC-driven T-cell priming.
TprK Sequence Diversity Accumulates during Infection of Rabbits withTreponema pallidumsubsp.pallidumNichols Strain
Authors: LaFond Rebecca E. , Centurion-Lara Arturo , Godornes Charmie , Van Voorhis Wesley C. , Lukehart Sheila A. 
Published: February 2006

ABSTRACTThetprKgene inTreponema pallidumundergoes antigenic variation. In allT. pallidumisolates examined to date, except the Nichols type strain, heterogeneoustprKsequences have been identified. This heterogeneity is localized to seven variable (V) regions, andtprKsequence diversity accumulates with serial passage in naïve rabbits. TheT. pallidumNichols genome described a singletprKsequence, and after decades of independent passage, only minortprKsequence diversity is seen among the Nichols strains from different laboratories. We hypothesized thatT. pallidumNichols is capable of only limitedtprKdiversification. To address this hypothesis, we passaged theT. pallidumNichols strain in naïve rabbits at the peak of infection (rapid passage) or after the adaptive immune response had cleared most organisms in vivo (slow passage). After 22 rapid passages (9- to 10-day intervals), notprKV region sequence changes were observed. In contrast, after two slow passages (30- to 35-day intervals), three V regions had sequences that were completely different from that of the original inoculum. New sequences were observed in all seven V regions by the fifth slow passage. In contrast to the rapid-passaged Nichols strain, rapid-passaged Chicago C, a clonal strain isolated from the highly diverse parent Chicago strain, developed significanttprKdiversification. These findings suggest thattprKvariation can occur, but at a lower rate, in Nichols and that immune pressure may be required for accumulation of bacteria with diversetprKsequences. Adaptation to growth in rabbits may explain the limited repertoire of V region sequences seen in the Nichols strain.
Screening forToxoplasma gondii-Regulated Transcriptional Responses in Lipopolysaccharide-Activated Macrophages
Authors: Lee Chiang W. , Bennouna Soumaya , Denkers Eric Y. 
Published: February 2006

ABSTRACTToxoplasma gondii-infected macrophages are blocked in production of the proinflammatory cytokines interleukin-12 (IL-12) and tumor necrosis factor alpha (TNF-α) upon activation with lipopolysaccharide (LPS). Here, we used pathway-focused cDNA arrays to identify additionalT. gondii-regulated transcriptional responses. Parasite infection decreased 57 (inclusive of IL-12 and TNF-α) and increased expression of 7 of 77 LPS-activated cytokine and cytokine-related genes. Interestingly, we found that the LPS-induced transcriptional response of the anti-inflammatory cytokine IL-10 was synergistically increased byT. gondii, results that we validated by conventional reverse transcription-PCR and enzyme-linked immunosorbent assay. Importantly, although the parasite exerted disparate effects in LPS-signaling leading to TNF-α versus IL-10 production, both responses required functional Toll-like receptor 4. We suggest that these effects represent parasite defense mechanisms to avoid or delay induction of antimicrobial activity and/or T-cell-mediated immunity duringToxoplasmainfection.
Binding of the Streptococcal Surface Glycoproteins GspB and Hsa to Human Salivary Proteins
Authors: Takamatsu Daisuke , Bensing Barbara A. , Prakobphol Akraporn , Fisher Susan J. , Sullam Paul M. 
Published: February 2006

ABSTRACT

GspB and Hsa are homologous surface glycoproteins of
Streptococcus gordonii
that bind sialic acid moieties on platelet membrane glycoprotein Ibα. Since this species is an important member of the oral flora, we examined the direct binding of these adhesins to human salivary proteins. Both GspB and Hsa bound low-molecular-weight salivary mucin MG2 and salivary agglutinin. Hsa also bound several other salivary proteins, including secretory immunoglobulin A. Screening of six oral streptococcal isolates revealed that at least two of the strains expressed GspB homologues. These results indicate that GspB-like adhesins may be important for oral bacterial colonization.
Synthesis of Syndecan-1 by Skeletal Muscle Cells Is an Early Response to Infection withTrichinella spiralisbut Is Not Essential for Nurse Cell Development
Authors: Beiting Daniel P. , Park Pyong Woo , Appleton Judith A. 
Published: February 2006

ABSTRACTTrichinella spiraliscreates a unique intracellular habitat in striated muscle. We report that a proteoglycan, syndecan-1, is induced early in infection yet is not essential for habitat development and exerts a modest influence on the immune response. This report is the first to address the requirement for a specific muscle protein in trichinellosis by using mice deficient in the relevant gene.
Modulation of Human Neutrophil Functions In Vitro by
Treponema denticola
Major Outer Sheath Protein
Authors: Puthengady Thomas Bina , Sun Chun Xiang , Bajenova Elena , Ellen Richard P. , Glogauer Michael 
Published: February 2006

ABSTRACT

In this study of human polymorphonuclear leukocytes (PMNs), pretreatment with
Treponema denticola
major outer sheath protein (Msp) inhibited formyl-methionyl-leucyl-phenylalanine (fMLP)-induced chemotaxis, phagocytosis of immunoglobulin G-coated microspheres, fMLP-stimulated calcium transients, and actin assembly. Msp neither altered oxidative responses to phorbol myristate or fMLP nor induced apoptosis. Msp selectively impairs chemotaxis and phagocytosis by impacting the PMN cytoskeleton.
Requirement of
norD
for
Brucella suis
Virulence in a Murine Model of In Vitro and In Vivo Infection
Authors: Loisel-Meyer Séverine , Jiménez de Bagüés Maria Pilar , Bassères Eugénie , Dornand Jacques , Köhler Stephan , Liautard Jean-Pierre , Jubier-Maurin Véronique 
Published: February 2006

ABSTRACT

A mutant of
Brucella suis
bearing a Tn
5
insertion in
norD
, the last gene of the operon
norEFCBQD
, encoding nitric oxide reductase, was unable to survive under anaerobic denitrifying conditions. The
norD
strain exhibited attenuated multiplication within nitric oxide-producing murine macrophages and rapid elimination in mice, hence demonstrating that
norD
is essential for
Brucella
virulence.
Structural Analysis of the Interaction between Shiga Toxin B Subunits and Linear Polymers Bearing Clustered Globotriose Residues
Authors: Watanabe Miho , Igai Katsura , Matsuoka Koji , Miyagawa Atsushi , Watanabe Toshiyuki , Yanoshita Ryohei , Samejima Yuji , Terunuma Daiyo , Natori Yasuhiro , Nishikawa Kiyotaka 
Published: February 2006

ABSTRACT
We previously developed linear polymers bearing clustered trisaccharides of globotriaosylceramide (Gb3) as orally applicable Shiga toxin (Stx) neutralizers. Here, using a Gb3 polymer with a short spacer tethering the trisaccharide to the core, we found that shortening the spacer length markedly reduced the binding affinity for Stx2 but not Stx1. Moreover, mutational analysis revealed that the essential binding sites of the terminal trisaccharides were completely different between Stx1 and Stx2. These results provide the molecular basis for the interaction between Stx B subunits and Gb3 polymers.
Identification of Secreted Cysteine Proteases from the Parasitic Nematode
Haemonchus contortus
Detected by Biotinylated Inhibitors
Authors: Yatsuda Ana P. , Bakker Nicole , Krijgsveld Jeroen , Knox David P. , Heck Albert J. R. , de Vries Erik 
Published: February 2006

ABSTRACT

Seven cathepsin B-like cysteine proteases (CBLs) were identified from the immunoprotective excretory-secretory products of
Haemonchus contortus
. Two-dimensional (2-D) zymography and biotinylated inhibitors were employed to localize active CBLs in 2-D protein gels. Mass spectrometry provided the identification of AC-4, HMCP1, HMCP2, and GCP7 as well as three novel CBLs encoded by clustered expressed sequence tags.
Anthropometry profiles of elite rugby players: quantifying changes in lean mass
Authors: Duthie G M , Pyne D B , Hopkins W G , Livingstone S , Hooper S L 
Published: February 2006

Objective:To demonstrate the utility of a practical measure of lean mass for monitoring changes in the body composition of athletes.Methods:Between 1999 and 2003 body mass and sum of seven skinfolds were recorded for 40 forwards and 32 backs from one Super 12 rugby union franchise. Players were assessed on 13 (7) occasions (mean (SD)) over 1.9 (1.3) years. Mixed modelling of log transformed variables provided a lean mass index (LMI) of the form mass/skinfoldsx, for monitoring changes in mass controlled for changes in skinfold thickness. Mean effects of phase of season and time in programme were modelled as percentage changes. Effects were standardised for interpretation of magnitudes.Results:The exponent x was 0.13 for forwards and 0.14 for backs (90% confidence limits ±0.03). The forwards had a small decrease in skinfolds (5.3%, 90% confidence limits ±2.2%) between preseason and competition phases, and a small increase (7.8%, 90% confidence limits ±3.1%) during the club season. A small decrease in LMI (∼1.5%) occurred after one year in the programme for forwards and backs, whereas increases in skinfolds for forwards became substantial (4.3%, 90% confidence limits ±2.2%) after three years. Individual variation in body composition was small within a season (within subject SD: body mass, 1.6%; skinfolds, 6.8%; LMI, 1.1%) and somewhat greater for body mass (2.1%) and LMI (1.7%) between seasons.Conclusions:Despite a lack of substantial mean changes, there was substantial individual variation in lean mass within and between seasons. An index of lean mass based on body mass and skinfolds is a potentially useful tool for assessing body composition of athletes.
Regular tai chi chuan exercise enhances functional mobility and CD4CD25 regulatory T cells
Authors: Yeh S-H , Chuang H , Lin L-W , Hsiao C-Y , Eng H L 
Published: February 2006

Background:The duration and vigour of physical exercise are widely considered to be critical elements that may positively or negatively affect physical health and immune response.Objectives:To investigate the effect of a 12 week programme of regular tai chi chuan exercise (TCC) on functional mobility, beliefs about benefits of exercise on physical and psychological health, and immune regulation in middle aged volunteers.Methods:This quasi-experimental research design involving one group with testing before and after the programme was conducted to measure the effect of 12 weeks of TCC exercise in 14 men and 23 women from the normal community.Results:Regular TCC exercise had a highly significant positive effect on functional mobility (p  =  0.001) and beliefs about the health benefits of exercise (p  =  0.013) in the 37 participants. Total white blood cell and red blood cell count did not change significantly, but a highly significant (p<0.001) decrease in monocyte count occurred. A significant (p  =  0.05) increase in the ratio of T helper to suppressor cells (CD4:CD8) was found, along with a significant (p  =  0.015) increase in CD4CD25 regulatory T cells. Production of the regulatory T cell mediators transforming growth factor β and interleukin 10 under specific antigen stimulation (varicella zoster virus) was also significantly increased after this exercise programme.Conclusions:A 12 week programme of regular TCC exercise enhances functional mobility, personal health expectations, and regulatory T cell function.
Prognostic value of intra-left ventricular electromechanical asynchrony in patients with mild hypertrophic cardiomyopathy compared with power athletes
Authors: D’Andrea A , Caso P , Cuomo S , Salerno G , Scarafile R , Mita C , De Corato G , Sarubbi B , Scherillo M , Calabrò R 
Published: February 2006

Objectives:We sought to assess the indexes of myocardial activation delay, using Doppler myocardial imaging (DMI), as potential diagnostic tools and predictors of cardiac events in patients with hypertrophic cardiomyopathy (HCM) compared with power athletes.Background:the distribution and magnitude of left ventricular (LV) hypertrophy are not uniform in patients with HCM, which results in heterogeneity of regional LV systolic function.Methods:The study population comprised 70 young patients with HCM (mean (SD) age 29.4 (5.9) years) with mild septal hypertrophy (15–19 mm) and 85 age and sex matched athletes with septal thickness >12 mm, followed up for 44.4 (10.8) months. Using pulsed DMI, myocardial peak velocities, systolic time intervals, and myocardial intraventricular and interventricular systolic delays were measured in six different basal myocardial segments.Results:DMI analysis showed in HCM lower myocardial both systolic and early diastolic peak velocities of all the segments. Patients with HCM also showed significant interventricular and intraventricular delay (p<0.0001), whereas athletes showed homogeneous systolic activation of the ventricular walls. During the follow up, seven sudden deaths occurred in the HCM group, while no cardiovascular event was observed in the group of athletes. In patients with HCM, intraventricular delay on DMI was the most powerful independent predictor of sudden cardiac death (p<0.0001). An intraventricular delay >45 ms identified with high sensitivity and specificity patients with HCM at higher risk of ventricular tachycardia and cardiac events (test accuracy 90.6%).Conclusions:DMI may be a valid supporting tool for the differential diagnosis between HCM and “athlete’s heart”. In patients with HCM, DMI indexes of intraventricular delay may provide additional information for selecting subgroups of patients with HCM at increased risk of ventricular arrhythmias and sudden cardiac death at follow up. Accordingly, such patients may benefit from early intensive treatment and survey.Miniabstract:Doppler myocardial imaging may represent a valid supporting tool for the differential diagnosis between mild hypertrophic cardiomyopathy (HCM) and “athlete’s heart”. In patients with HCM, DMI indexes of intraventricular delay may provide additional information for selecting subgroups of patients with HCM at increased risk of ventricular arrhythmias and sudden cardiac death at follow up.