bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effect of B7-2 and CD40 Signals from Activated Antigen-Presenting Cells on the Ability of Zwitterionic Polysaccharides To Induce T-Cell Stimulation
Authors: Stephen Tom Li , Niemeyer Marcus , Tzianabos Arthur O. , Kroenke Martin , Kasper Dennis L. , Kalka-Moll Wiltrud M. 
Published: March 2005

ABSTRACTCarbohydrates have been thought to stimulate immune responses independently of T cells; however, zwitterionic polysaccharides (ZPSs) from the capsules of some bacteria elicit potent CD4+-T-cell responses in vivo and in vitro. We demonstrated that HLA-DR on professional antigen-presenting cells (APCs) is required for ZPS-induced T-cell proliferation in vitro (15). Recently, it was shown that ZPSs are processed to low-molecular-weight carbohydrates by a nitric oxide-mediated mechanism in endosomes and locate in the major histocompatibility complex class II pathway (5, 15). The effect of the ZPS-mediated expression of HLA-DR and costimulatory molecules on the APC and T-cell engagement and subsequent T-cell activation has not been elucidated. Herein, we report that ZPS-mediated induction of HLA-DR-surface expression and T-cell proliferation are maximally enhanced after incubation of APCs for 8 h with ZPS. Treatment of APCs with bafilomycin A inhibits the up-regulation of ZPS-mediated HLA-DR surface expression and leads to inhibition of T-cell proliferation. Monoclonal antibodies (MAbs) to the costimulatory molecules B7-2 and CD40L specifically block ZPS-mediated T-cell activation, while a MAb to B7-1 does not. Surface expression of B7-2 and B7-1 but not of CD40 is maximally enhanced at 8 to 16 h of treatment of APCs with ZPS. The results demonstrate that the cellular immune response to ZPS depends on the translocation of HLA-DR to the cell surface and requires costimulation via B7-2 and CD40 on activated APCs. The implication is that activation of ZPS-specific T cells requires an orchestrated arrangement of both presenting and costimulatory molecules to form an immunological synapse.
Role of SraP, a Serine-Rich Surface Protein of
Staphylococcus aureus
, in Binding to Human Platelets
Authors: Siboo Ian R. , Chambers Henry F. , Sullam Paul M. 
Published: March 2005

ABSTRACT

The binding of bacteria to platelets is a postulated central event in the pathogenesis of infective endocarditis. Platelet binding by
Streptococcus gordonii
is mediated in large part by GspB, a high-molecular-mass cell wall glycoprotein. Although
Staphylococcus aureus
has a GspB homolog (SraP), little is known about its function. SraP has a calculated molecular mass of 227 kDa and, like GspB, is predicted to contain an atypical N-terminal signal sequence, two serine-rich repeat regions (srr1 and srr2) separated by a nonrepeat region, and a C-terminal cell wall anchoring motif (LPDTG). To assess whether SraP contributes to platelet binding, we compared the binding to human platelets of
S. aureus
strain ISP479C and of an isogenic variant (strain PS767) in which
sraP
had been disrupted by allelic replacement. Platelet binding in vitro by PS767 was 47% ± 17% (mean ± standard deviation) lower than that of ISP479C (
P
< 0.001). In addition, a recombinant fragment of SraP containing srr1 and the nonrepeat region was found to bind platelets directly. Binding was saturable, suggesting a receptor-ligand interaction. When tested in a rabbit model of endocarditis, in which each animal was simultaneously infected with ISP479C and PS767 at a ratio of approximately 1:1, the titers of the mutant strain within vegetations were significantly lower than those of the parent strain at 1 and 24 h postinfection. These results indicate that SraP can mediate the direct binding of
S. aureus
to platelets and that the platelet-binding domain of this glycoprotein is located within its N-terminal region. Moreover, the expression of SraP appears to be a virulence determinant in endovascular infection.
Intranasal Interleukin-12 Treatment for Protection against Respiratory Infection with theFrancisella tularensisLive Vaccine Strain
Authors: Duckett Nathalie S. , Olmos Sofia , Durrant Douglas M. , Metzger Dennis W. 
Published: March 2005

ABSTRACTFrancisella tularensisis a gram-negative intracellular bacterium that can induce lethal respiratory infection in humans and rodents. However, little is known about the role of innate or adaptive immunity in protection from respiratory tularemia. In the present study, the role of interleukin-12 (IL-12) in inducing protective immunity in the lungs against intranasal infection of mice with the live vaccine strain (LVS) ofF. tularensiswas investigated. It was found that gamma interferon (IFN-γ) and IL-12 were strictly required for protection, since mice deficient in IFN-γ, IL-12 p35, or IL-12 p40 all succumbed to LVS doses that were sublethal for wild-type mice. Furthermore, exogenous IL-12 treatment 24 h before intranasal infection with a lethal dose of LVS (10,000 CFU) significantly decreased bacterial loads in the lungs, livers, and spleens of wild-type BALB/c and C57BL/6 mice and allowed the animals to survive infection; such protection was not observed in IFN-γ-deficient mice. The resistance induced by IL-12 to LVS infection was still observed in NK cell-deficient beige mice but not in CD8−/−mice. These results demonstrate that exogenous IL-12 delivered intranasally can prevent respiratory tularemia through a mechanism that is at least partially dependent upon the expression of IFN-γ and CD8 T cells.
Lipopolysaccharide Is Transferred from High-Density to Low-Density Lipoproteins by Lipopolysaccharide-Binding Protein and Phospholipid Transfer Protein
Authors: Levels J. H. M. , Marquart J. A. , Abraham P. R. , van den Ende A. E. , Molhuizen H. O. F. , van Deventer S. J. H. , Meijers J. C. M. 
Published: March 2005

ABSTRACTLipopolysaccharide (LPS), the major outer membrane component of gram-negative bacteria, is a potent endotoxin that triggers cytokine-mediated systemic inflammatory responses in the host. Plasma lipoproteins are capable of LPS sequestration, thereby attenuating the host response to infection, but ensuing dyslipidemia severely compromises this host defense mechanism. We have recently reported thatEscherichia coliJ5 and Re595 LPS chemotypes that contain relatively short O-antigen polysaccharide side chains are efficiently redistributed from high-density lipoproteins (HDL) to other lipoprotein subclasses in normal human whole blood (ex vivo). In this study, we examined the role of the acute-phase proteins LPS-binding protein (LBP) and phospholipid transfer protein (PLTP) in this process. By the use of isolated HDL containing fluorescent J5 LPS, the redistribution of endotoxin among the major lipoprotein subclasses in a model system was determined by gel permeation chromatography. The kinetics of LPS and lipid particle interactions were determined by using Biacore analysis. LBP and PLTP were found to transfer LPS from HDL predominantly to low-density lipoproteins (LDL), in a time- and dose-dependent manner, to induce remodeling of HDL into two subpopulations as a consequence of the LPS transfer and to enhance the steady-state association of LDL with HDL in a dose-dependent fashion. The presence of LPS on HDL further enhanced LBP-dependent interactions of LDL with HDL and increased the stability of the HDL-LDL complexes. We postulate that HDL remodeling induced by LBP- and PLTP-mediated LPS transfer may contribute to the plasma lipoprotein dyslipidemia characteristic of the acute-phase response to infection.
Generation of Attenuated
Mycobacterium bovis
Strains by Signature-Tagged Mutagenesis for Discovery of Novel Vaccine Candidates
Authors: Collins Desmond M. , Skou Bronwyn , White Stefan , Bassett Shalome , Collins Lauren , For Raewyn , Hurr Kathryn , Hotter Grant , de Lisle Geoffrey W. 
Published: March 2005

ABSTRACT

Mycobacterium bovis
, a member of the
Mycobacterium tuberculosis
complex, has a particularly wide host range and causes tuberculosis in most mammals, including humans. A signature tag mutagenesis approach, which employed illegitimate recombination and infection of guinea pigs, was applied to
M. bovis
to discover genes important for virulence and to find potential vaccine candidates. Fifteen attenuated mutants were identified, four of which produced no lesions when inoculated separately into guinea pigs. One of these four mutants had nine deleted genes including
mmpL4
and
sigK
and, in guinea pigs with aerosol challenge, provided protection against tuberculosis at least equal to that of
M. bovis
BCG. Seven mutants had mutations near the
esxA
(
esat-6
) locus, and immunoblot analysis of these confirmed the essential role of other genes at this locus in the secretion of EsxA (ESAT-6) and EsxB (CFP10). Mutations in the eight other attenuated mutants were widely spread through the chromosome and included
pks1
, which is naturally inactivated in clinical strains of
M. tuberculosis
. Many genes identified were different from those found by signature tag mutagenesis of
M. tuberculosis
by use of a mouse infection model and illustrate how the use of different approaches enables identification of a wider range of attenuating mutants.
Sweat rate and fluid turnover in American football players compared with runners in a hot and humid environment
Authors: Godek S Fowkes , Bartolozzi A R , Godek J J 
Published: March 2005

Objectives:To determine sweat rate (SwR) and fluid requirements for American footballers practicing in a hot, humid environment compared with cross country runners in the same conditions.Methods:Fifteen subjects, 10 footballers and five runners, participated. On the 4th and 8th day of preseason two a day practices, SwR during exercise was determined in both morning and afternoon practices/runs from the change in body mass adjusted for fluids consumed and urine produced. Unpairedttests were used to determine differences between groups.Results:Overall SwR measured in litres/h was higher in the footballers than the cross country runners (2.14 (0.53)v1.77 (0.4); p<0.01). Total sweat loss in both morning (4.83 (1.2)v1.56 (0.39) litres) and afternoon (4.8 (1.2)v1.97 (0.28) litres) practices/runs, and daily sweat losses (9.4 (2.2)v3.53 (0.54) litres) were higher in the footballers (p<0.0001). The footballers consumed larger volumes of fluid during both morning and afternoon practices/runs (23.9 (8.9)v5.5 (3.1) ml/min and 23.5 (7.3)v13.6 (5.6) ml/min; p<0.01). For complete hydration, the necessary daily fluid consumption calculated as 130% of daily sweat loss in the footballers was 12.2 (2.9) litres compared with 4.6 (0.7) litres in the runners (p<0.0001). Calculated 24 hour fluid requirements in the footballers ranged from 8.8 to 19 litres.Conclusions:The American footballers had a high SwR with large total daily sweat losses. Consuming large volumes of hypotonic fluid may promote sodium dilution. Recommendations for fluid and electrolyte replacement must be carefully considered and monitored in footballers to promote safe hydration and avoid hyponatraemia.
Men, muscles, and body image: comparisons of competitive bodybuilders, weight trainers, and athletically active controls
Authors: Pickett T C , Lewis R J , Cash T F 
Published: March 2005

Objectives:To investigate body image and psychosocial adjustment among competitive bodybuilders, non-competitive weight trainers, and athletically active men.Methods:Participants were 40 men in each of the three groups who were assessed on body composition and multiple facets of body image evaluation, investment and anxiety, eating attitudes, and social self esteem.Results:Relative to the other two groups, competitive bodybuilders had greater body mass due to fat-free body mass. Although groups did not differ in their situational body image discomfort, competitive bodybuilders and weight trainers had a more positive global appearance evaluation and were more psychologically invested in their physical appearance. Compared with active controls, men in both weightlifting groups were more satisfied with their upper torso and muscle tone. Competitive bodybuilders reported more mid torso satisfaction than the other two groups. Competitive bodybuilders also wished to be significantly heavier than controls did and reported higher social self esteem but greater eating disturbance.Conclusions:The findings suggest that competitive bodybuilders as a group are not more “muscle dysmorphic” than either non-competitive weight trainers or physically active men who do not train with weights.
Effect of fluid ingestion on neuromuscular function during prolonged cycling exercise
Authors: Vallier J-M , Grego F , Basset F , Lepers R , Bernard T , Brisswalter J 
Published: March 2005

Objectives:To investigate the effects of fluid ingestion on neuromuscular function during prolonged cycling exercise.Methods:Eight well trained subjects exercised for 180 minutes in a moderate environment at a workload requiring ∼60% maximal oxygen uptake. Two conditions, fluid (F) and no fluid (NF) ingestion, were investigated.Results:During maximal voluntary isometric contraction (MVC), prolonged cycling exercise reduced (p<0.05) the maximal force generating capacity of quadriceps muscles (after three hours of cycling) and root mean square (RMS) values (after two hours of cycling) with no difference between the two conditions despite greater body weight loss (p<0.05) in NF. The mean power frequency (MPF) for vastus lateralis muscle was reduced (p<0.05) and the rate of force development (RFD) was increased (p<0.05) only during NF. During cycling exercise, integrated electromyographic activity and perceived exertion were increased in both conditions (p<0.05) with no significant effect of fluid ingestion.Conclusions:The results suggest that fluid ingestion did not prevent the previously reported decrease in maximal force with exercise duration, but seems to have a positive effect on some indicators of neuromuscular fatigue such as mean power frequency and rate of force development during maximal voluntary contraction. Further investigations are needed to assess the effect of change in hydration on neural mechanisms linked to the development of muscular fatigue during prolonged exercise.
A controlled study on batted ball speed and available pitcher reaction time in slowpitch softball
Authors: McDowell M , Ciocco M V 
Published: March 2005

Objectives:To investigate safety risks in slowpitch softball by conducting laboratory and experimental studies on the performance of high tech softball bats with polyurethane softballs. To compare the results with the recommended safety standards.Methods:ASTM standard compression testing of seven softball models was conducted. Using these seven softball models, bat/ball impact testing was performed using seven adult male softball players and six high tech softball bat models to determine mean batted ball speeds. Over 500 bat/ball impact measurements were recorded and analysed. Available pitcher reaction time was calculated from the mean batted ball speed measurements.Results:According to the United States Specialty Sports Association and the Amateur Softball Association, the maximum initial batted ball speed should be 137.2 km/h, which corresponds to a minimum pitcher reaction time of 0.420 second. These experiments produced mean batted ball speeds of 134.0–159.7 km/h, which correspond to available pitcher reaction times of 0.409–0.361 second.Conclusion:The use of high tech softball bats with polyurethane softballs can result in batted ball speeds that exceed the recommended safety limits, which correspond to decreased available pitcher reaction times.
An assessment of injuries in college cheerleading: distribution, frequency, and associated factors
Authors: Jacobson B H , Redus B , Palmer T 
Published: March 2005

Background:Over 50% of all catastrophic injuries in women’s sport occur in cheerleading, but unlike other sports, no central tracking system exists.Objective:To obtain, describe, and compare cheerleading injury data and associated factors.Methods:Cheerleaders from randomly chosen division IA universities completed surveys designed to acquire basic information and data on injury frequency, type, and location, practice frequency and duration, and related factors.Results:Participants (n  =  440) were aged 18–23 (mean (SD) 20.2 (1.8)) with 6.6 (2.2) years of experience. Most respondents (78%) reported having suffered one or more career injury. Of those injured, 39.7% reported an injury within the preceding year. Respondents sustained 1.0 (0.91) injuries during the preceding year with 1.8 (2.2) days lost. Ankles (44.9%) and wrist/hand (19.3%) were the most commonly injured. Practice frequency and duration were 205 (61.5) days a year (range 80–300) and 2.8 (0.7) hours (range 1.5–4) respectively. Training included stretching (99.7%), endurance activities (87.1%), and weight training (92.9%).Conclusion:Guidelines and policy governing cheerleading should be developed according to mandatory injury reporting similar to that currently used in other sports.
Motivation and satisfaction among polyclinic volunteers at the 2002 Winter Olympic and Paralympic Games
Authors: Reeser J C , Berg R L , Rhea D , Willick S 
Published: March 2005

Background:The Olympic and Paralympic Games rely heavily on volunteers to provide many essential services, including medical care of athletes.Objective:This preliminary investigation sought to characterise the motivational influences and factors responsible for the satisfaction of Olympic and Paralympic healthcare volunteers.Methods:The 2002 Winter Games polyclinic healthcare volunteers were asked to complete a questionnaire designed to elicit information about their motives for volunteering and the factors that contributed to their satisfaction with their volunteer experience.Results:There was no significant difference in the motivation or satisfaction summary scores based on event worked. There was a strong positive correlation between motivation and satisfaction. Physician respondents had a lower mean motivation score than did non-physician volunteers.Conclusions:There were no significant motivational differences between Olympic and Paralympic volunteers, but there were several differences noted between physician and non-physician volunteers. The 2002 polyclinic volunteers appear to have been motivated by a complex process best described as “enlightened self interest,” and all were generally well satisfied with their experience. These results may assist organisers of future Games in selecting appropriately motivated volunteer personnel and creating rewarding work environments for them.
If smoking increases absences, does quitting reduce them?
Authors: Sindelar J L , Duchovny N , Falba T A , Busch S H 
Published: March 2005

Objective:This study examined the impact of smoking, quitting, and time since quit on absences from work.Methods:Data from the nationally representative Tobacco Use Supplements of the 1992/93, 1995/96, and 1998/99 Current Population Surveys were used. The study included full time workers aged between 18–64 years, yielding a sample size of 383 778 workers. A binary indicator of absence due to sickness in the last week was analysed as a function of smoking status including time since quit for former smokers. Extensive demographic variables were included as controls in all models.Results:In initial comparisons between current and former smokers, smoking increased absences, but quitting did not reduce them. However, when length of time since quit was examined, it was discovered that those who quit within the last year, and especially the last three months, had a much greater probability of absences than did current smokers. As the time since quitting increased, absences returned to a rate somewhere between that of never and current smokers. Interactions between health and smoking status significantly improved the fit of the model.Conclusions:Smokers who quit reduced their absences over time but increase their absences immediately after quitting. Quitting ill may account for some but not all of this short run impact.
The Competitive Advantage of Moneylenders Over Banks in Rural Palestine
Authors: Nadan Amos 
Published: March 2005

AbstractAccording to the British Government in Mandate Palestine, the tendency of the fallahin (Arab peasants) to "strategic default" and the monopolistic power of local moneylenders led to high interest lending in rural areas. The government sought to remedy this by assisting banks in collecting bad debts, by guaranteeing some bank loans and by imposing the maximum legal interest rate. However, the colonial perception was incorrect. Defaults were usually "involuntary" as a result of natural and occasionally man-made hazards (thus creating a high interest rate environment), and the moneylending market was "contestable." In such an environment, despite government assistance, moneylenders had a comparative advantage over banks. They were usually merchants who could easily utilise collateral on loans (crops and lands); they ignored the law of maximum interest rate and they had good information about borrowers. For these reasons moneylenders remained the main source of credit for the fallahin. D'après le gouvernment britannique dans la Palestine sous mandat, la propension des fallahin (les paysans arabes) à se trouver en « défaut de paiement stratégique » et le monopole des prêteurs locaux expliquent les prêts à intérêts élevés dans les régions rurales. Le gouvernent essaya de pallier cette situation en aidant les banques à reprendre les créances irrécouvrables, en garantissant quelques prêts bancaires et en imposant un taux d'intérêt maximum légal. Cette interprétation coloniale était cependant erronée. Les défauts de paiement étaient en général « involontaires » , le résultat d'aléas d'ordre naturel ou parfois humain (créant un taux d'intérêt élevé) et le marché du prêt était « contestable ». Dans ces circonstances, et malgré l'aide gouvernementale, les prêteurs avaient un avantage par rapport aux banques. Il s'agissait en général de marchands qui pouvaient facilement faire usage des nantissements garantissant les prêts (récoltes ou terrains); ils ne tenaient pas compte de la loi de taux d'intérêt maximum et ils étaient bien informés sur les emprunteurs. Tous ces faits expliquent pourquoi les prêteurs demeuraient, pour les fallahin, la principale source de crédit.
Studying Negotiations in Context: An Ethnographic Approach
Authors: Friedman Ray 
Published: March 2005

AbstractEthnographic research offers an alternative approach which can provide insights into the types of complex situations that negotiators really face. This approach is not easy – it can be more time consuming, costly, and difficult than other research methods – but the payoff comes from the way these in-depth studies challenge scholars to develop new ideas and theories, based on what really happens in negotiations rather than on the logical next step in a series of experiments.
The Church of Jesus Christ: An Anglican Response
Authors: Davie Martin 
Published: March 2005

AbstractFollowing an initial exploration of the teaching of The Church of Jesus Christ, this paper argues that a comparison of The Church of Jesus Christ with the Thirty Nine Articles and recent Anglican ecumenical statements and agreements shows a significant degree of agreement between The Church of Jesus Christ and Anglican theology and ecclesiology. This agreement reflects the fact that both the Anglican tradition and the traditions of the churches in the Community of Protestant Churches in Europe have been shaped by the Reformation. It also shows the influence of a growing ecumenical consensus on ecclesiological issues. However, alongside this agreement there also remain significant points of difference about the relation between divine and human activity in the Church, the importance of tradition, the holiness of the Church and the nature of the Church’s unity. These points of difference need to be explored and debated by Anglicans and members of the Churches of the Community of Protestant Churches in Europe (CPCE).