bluuebunny/crossref_metadata_2025_split huggingface dataset:
Pseudomonas aeruginosa
Induces Localized Immunosuppression during Pneumonia
Authors: Diaz Maureen H. , Shaver Ciara M. , King John D. , Musunuri Srinidhi , Kazzaz Jeffrey A. , Hauser Alan R. 
Published: July 2008

ABSTRACT

Hospital-acquired bacterial pneumonia is a common and serious complication of modern medical care. Many aspects of such infections remain unclear, including the mechanisms by which invading pathogens resist clearance by the innate immune response and the tendency of the infections to be polymicrobial. Here, we used a mouse model of infection to show that
Pseudomonas aeruginosa
, a leading cause of hospital-acquired pneumonia, interferes with the ability of recruited phagocytic cells to eradicate bacteria from the lung. Early in infection, phagocytic cells, predominantly neutrophils, are recruited to the lungs but are incapacitated when they enter the airways by the
P. aeruginosa
toxin ExoU. The resulting paucity of functioning phagocytes allows
P. aeruginosa
to persist within the lungs and results in local immunosuppression that facilitates superinfection with less-pathogenic bacteria. Together, our results provide explanations for previous reports linking ExoU-secreting
P. aeruginosa
with more severe pulmonary infections and for the tendency of hospital-acquired pneumonia to be polymicrobial.
Use of
mchI
Encoding Immunity to the Antimicrobial Peptide Microcin H47 as a Plasmid Selection Marker in Attenuated Bacterial Live Vectors
Authors: Fang Chee-Mun , Wang Jin Yuan , Chinchilla Magaly , Levine Myron M. , Blackwelder William C. , Galen James E. 
Published: July 2008

ABSTRACT

Live attenuated bacterial strains expressing heterologous antigens represent an attractive vaccine development strategy. However, the use of drug resistance genes for the selection of expression plasmids introduced into live vectors poses theoretical health risks. Therefore, we developed a novel approach for plasmid selection based on immunity to the antimicrobial peptide microcin H47 (MccH47). Two expression plasmids encoding the reporter green fluorescent protein (GFPuv) were constructed; selection markers comprised either
mchI
, conferring immunity to MccH47 (pGEN222I), or
bla
(encoding β-lactamase), conferring conventional resistance to ampicillin (pGEN222). GFPuv-specific serum immunoglobulin G (IgG) antibody responses were analyzed in mice immunized intranasally either with
Salmonella enterica
serovar Typhi CVD 908-
htrA
or
Shigella flexneri
2a CVD 1208S live vector and were boosted parenterally with purified GFPuv. Similar IgG antibody responses were observed for both pGEN222 and pGEN222I when either CVD 1208S or CVD 908-
htrA
(pGEN222I) was used as the carrier. Interestingly, CVD 908-
htrA
(pGEN222I) elicited a significantly higher IgG response than CVD 908-
htrA
(pGEN222). We also compared the priming potential of homologous priming either with CVD 908-
htrA
(pGEN222I) or CVD 1208S(pGEN222I) to heterologous priming first with CVD 908-
htrA
(pGEN222I) and then with CVD 1208S(pGEN222I) and vice versa. Immunization with two unrelated live vectors significantly enhanced the IgG responses compared to responses engendered by homologous CVD 908-
htrA
(pGEN222I) but not to those of CVD 1208S(pGEN222I). MccH47 offers an alternate system for plasmid selection in bacterial live vectors that greatly improves their clinical acceptability. Furthermore, the success of the heterologous priming strategy supports the feasibility of the future development of multivalent live vector-based immunization strategies against multiple human pathogens.
Mycoplasma pneumoniae
Infection Induces Reactive Oxygen Species and DNA Damage in A549 Human Lung Carcinoma Cells
Authors: Sun Gongping , Xu Xuefeng , Wang Yingshuo , Shen Xiaoyun , Chen Zhimin , Yang Jun 
Published: July 2008

ABSTRACT

Mycoplasma pneumoniae
is a frequent cause of community-acquired bacterial respiratory infections in children and adults. In the present study, using a proteomic approach, we studied the effects of
M. pneumoniae
infection on the protein expression profile of A549 human lung carcinoma cells.
M. pneumoniae
infection induced changes in the expression of cellular proteins, in particular a group of proteins involved in the oxidative stress response, such as glucose-6-phosphate 1-dehydrogenase, NADH dehydrogenase (ubiquinone) Fe-S protein 2, and ubiquinol-cytochrome
c
reductase complex core protein I mitochondrial precursor. The oxidative status of
M. pneumoniae
-infected cells was evaluated, and the results revealed that
M. pneumoniae
infection indeed caused generation of reactive oxygen species (ROS). It was further shown that
M. pneumoniae
infection also induced DNA double-strand breaks, as demonstrated by the formation of γH2AX foci. On the other hand, an ROS scavenger,
N
-acetylcysteine, could inhibit the ROS generation, as well as decrease γH2AX focus formation. This is the first report showing that
M. pneumoniae
infection can directly induce DNA damage, at least partially, through the generation of ROS, and thus this report strengthens the powerful application of proteomics in the study of the pathogenesis of
M. pneumoniae
.
Differential Expression of a Putative CarD-Like Transcriptional Regulator, LtpA, in
Borrelia burgdorferi
Authors: Yang X. Frank , Goldberg Martin S. , He Ming , Xu Haijun , Blevins Jon S. , Norgard Michael V. 
Published: July 2008

ABSTRACT

The availability of microbial genome information has provided a fruitful opportunity for studying regulatory networks in a variety of pathogenic bacteria. In an initial effort to elucidate regulatory networks potentially involved in differential gene expression by the Lyme disease pathogen
Borrelia burgdorferi
, we have been investigating the functions and regulation of putative transcriptional regulatory factors predicted to be encoded within the
B. burgdorferi
genome. Herein we report the regulation of one of the predicted transcriptional regulators, LtpA (BB0355), which is homologous to the transcriptional regulator CarD from
Myxococcus xanthus
. LtpA expression was assessed in response to various environmental stimuli. Immunoblot and quantitative reverse transcription-PCR analyses revealed that unlike many well-characterized differentially regulated
Borrelia
genes whose expression is induced by elevated temperature, the expression of LtpA was significantly downregulated when spirochetes were grown at an elevated temperature (37°C), as well as when the bacteria were cultivated in a mammalian host-adapted environment. In contrast, LtpA was induced at a lower culture temperature (23°C). Further analyses indicated that the downregulation of LtpA was not dependent on the Rrp2-RpoN-RpoS regulatory pathway, which is involved in the downregulation of OspA when
B. burgdorferi
is grown in a mammalian host-adapted environment. LtpA protein levels in
B. burgdorferi
were unaltered in response to changes in the pH in the borrelial cultures. Multiple attempts to generate an LtpA-deficient mutant were unsuccessful, which has hampered the elucidation of its role in pathogenesis. Given that LtpA is exclusively expressed during borrelial cultivation at a lower temperature, a parameter that has been widely used as a surrogate condition to mimic
B. burgdorferi
in unfed (flat) ticks, and because LtpA is homologous to a known transcriptional regulator, we postulate that LtpA functions as a regulator modulating the expression of genes important to
B. burgdorferi
's survival within its arthropod vector.
Immunoproteomics To Examine Cystic Fibrosis Host Interactions with Extracellular
Pseudomonas aeruginosa
Proteins
Authors: Upritchard Hamish G. , Cordwell Stuart J. , Lamont Iain L. 
Published: July 2008

ABSTRACT

The lungs of patients with cystic fibrosis (CF) are typically chronically infected with
Pseudomonas aeruginosa
. We used an immunoproteomics approach to analyze the responses of patients to secreted
P. aeruginosa
proteins. Extracellular proteins from
P. aeruginosa
strain PAO1 that had been grown to stationary phase were separated by two-dimensional polyacrylamide gel electrophoresis and analyzed by Western blotting using sera from four chronically infected patients. Sera from all four patients detected multiple extracellular proteins. The identities of selected proteins recognized by antisera were determined. Production of at least four of these proteins (azurin and three proteases: elastase, PrpL, and PasP) is governed by quorum sensing, consistent with active bacterial quorum sensing in the lungs of CF patients. The CF lung is generally thought to be an iron-deficient environment for infecting bacteria, and growing the bacteria in the presence of an iron-chelating agent, ethylene-diamine-di(
o
-hydroxyphenylacetic acid), enabled detection of additional proteins that were recognized by patient sera. The sera also detected multiple proteins from cells in the logarithmic growth phase, and protein identification suggested that most of these were the result of cell lysis or secretion in membrane vesicles. Comparison with extracellular proteins from a second
P. aeruginosa
strain, strain Pa4, showed that many proteins recognized by patient sera are common to both strains, although there are also some strain-specific extracellular proteins. Our data show that while there are some differences in the responses of different patients to
P. aeruginosa
, there are also many similarities, and that an immunoproteomics approach enables the identification of proteins that are made by
P. aeruginosa
during infection.
Clinical predictors of time to return to competition and of recurrence following hamstring strain in elite Australian footballers
Authors: Warren Price , Gabbe Belinda J , Schneider-Kolsky Michal , Bennell Kim L 
Published: July 2008

ObjectiveTo investigate early clinical predictors of time to return to competition and of recurrence following hamstring strain.DesignProspective observational study.SettingElite level of Australian football competition.Participant59 players who suffered a hamstring strain in 2002 season.PredictorsClinical assessment by a physiotherapist and questionnaire.Main outcome measuresTime taken to return to play and recurrence of hamstring injury within 3 weeks.ResultsPlayers taking more than 1 day to walk pain-free were significantly more likely (p=0.018) to take longer than 3 weeks to return to competition (adjusted odds ratio 4.0; 95% CI 1.3 to 12.6). Nine players (15.2%) experienced an injury recurrence, all involving the biceps femoris. Recurrence was more likely in players who reported a hamstring injury in the past 12 months (adjusted odds ratio 19.6; 95% CI 1.5 to 261.0; p=0.025).ConclusionTime to walk pain-free and previous hamstring injury are predictors of time to return to competition and recurrence, respectively, and should be included in a clinical assessment to aid in prognosis.
The influence of feeding on aerial and aquatic oxygen consumption, nitrogenous waste excretion, and metabolic fuel usage in the African lungfish, Protopterus annectens
Authors: Iftikar F. I. , Patel M. , Ip Y. K. , Wood C. M. 
Published: July 2008

We studied the utilization of air versus water as a respiratory medium for O2consumption (Mo2) in the bimodally breathing African lungfish, Protopterus annectens (Owen, 1839), (151.2 ± 3.7 g) at 26–28 °C. We also investigated the impact of a single meal on this respiratory allocation and nitrogenous waste excretion in lungfish entrained to a 48 h feeding cycle. Correction for the “microbial blank” was found to be critically important in assessing the aquatic component of Mo2. After correction, total Mo2was low (~1000 μmol·kg–1·h–1), and lungfish took about 40% of Mo2from water and 60% from air. Following a meal of chironomid larvae (3.3% of body mass), Mo2values from both air and water increased in proportion over the first 3 h and continued to increase to a peak at 5–8 h postfeeding, at which point total Mo2(still 40% from water) was approximately 2.5-fold greater than the prefeeding level. When the same fish, entrained to the same 48 h feeding regime, were fasted, Mo2declined then later increased prior to the next anticipated feeding. In fed fish, the elevation in Mo2relative to fasted values was approximately 3-fold at 0–3 h and 9-fold at 5–8 h. This specific dynamic action (SDA) effect lasted until 23–26 h and amounted to only 9.5% of the oxycalorific content of the ingested meal. N-waste efflux was only slightly elevated after feeding, where there was a tendency for greater urea–N excretion (significant at 42–48 h); however, the lungfish remained ammoniotelic overall during the 48 h postfeeding period.
Role of predation and hunting on eastern cottontail mortality at Cape Cod National Seashore, Massachusetts
Authors: Boland Kelly M. , Litvaitis John A. 
Published: July 2008

The degree that hunting may influence game populations depends on whether hunting mortality is additional to (additive) or replaces (compensatory) natural-caused mortalities. In response to limited information on the effects of exploitation on eastern cottontail ( Sylvilagus floridanus (J.A. Allen, 1890)) populations within Cape Cod National Seashore (CCNS), we initiated an investigation of cause-specific mortality using transmitter-equipped cottontails in hunted and nonhunted areas as a way to examine the additive versus compensatory aspect of hunting. Predation caused >70% of all deaths, whereas hunting caused 10% of deaths in the areas sampled. Survival rate was substantially lower among hunted sites (0.05) than at nonhunted sites (0.19) during the winter–spring of year 1, but there was no difference between hunted (0.33) and nonhunted (0.40) sites during year 2. Lower survival in year 1 was likely due to deep and persistent snow that increased vulnerability to predation and probably reduced the prospect for hunting mortalities to be compensated by reductions among other mortality factors. However, at least partial compensation apparently occurred during year 2 when winter weather was less severe. Cottontails at CCNS are near the northern edge of their geographic range and therefore may be ultimately limited by severe weather conditions. Compared with predation, we do not believe that the current levels and distributions of hunting influence cottontail populations at CCNS.
Algorithm 882
Authors: van Deun Joris , Deckers Karl , Bultheel Adhemar , Weideman J. A. C. 
Published: July 2008

We present a numerical procedure to compute the nodes and weights in rational Gauss-Chebyshev quadrature formulas. Under certain conditions on the poles, these nodes are near best for rational interpolation with prescribed poles (in the same sense that Chebyshev points are near best for polynomial interpolation). As an illustration, we use these interpolation points to solve a differential equation with an interior boundary layer using a rational spectral method.
The algorithm to compute the interpolation points (and, if required, the quadrature weights) is implemented as a Matlab program.
Algebraic computations and applications to geometry (abstract only)
Authors: Tsigaridas Elias P. 
Published: July 2008

Real algebraic numbers are the real numbers that are real roots of univariate polynomials with integer coefficients. We study exact algorithms, from a theoretical and an implementation point of view, based on integer arithmetic of arbitrary precision, for computations with real algebraic numbers and applications of these algorithms on problems and algorithms in non linear computational geometry.
In order to construct a real algebraic number we must compute the real roots of a univariate polynomial with integer cofficients. We unify and simplify the theory behind the subdivision based algorithms for real root isolation and we improve the complexity of the algorithm that is based on the continued fraction expansion of the real numbers. The best known complexity bound up today is achieved using new techniques. Moreover, we prove that the bound holds for non square-free polynomials and that in the same complexity bound we can compute the multiplicities of the real roots. We prove a new bound for the expected complexity of the algorithm based on continued fractions. We generalize the real root isolation algorithms to bivariate polynomial systems. Our experimental analysis proves the effectiveness of our methods.
The algorithms that we consider for computations with real algebraic numbers are construction, comparison, sign evaluation and quantifier elimination. If the degree of the polynomial is small, i.e. ≤ 4 in the univariate case and ≤ 2 in the bivariate case, we propose special purpose algorithms that have constant arithmetic complexity. For all the algorithms we present a C++ implementation and an experimental analysis.
In computational geometry we study the predicates needed by the algorithms for the arrangement of elliptic arcs in the plane and the computation of the Voronoi diagram of ellipses, also in the plane. Finally, given a convex lattice polygon we study algorithms for decomposing it to two other convex lattice polygons, such that their Minkowski sum is the original polygon.
SAGE and coding theory (abstract only)
Authors: Joyner David , Miller Robert 
Published: July 2008

This is a very brief survey of recent work in SAGE on implementing algorithms to compute with linear block codes. http://www.sagemath.org.
SAGE is a mathematical software package similar to the "big M's" (Maple, Mathematica, Magma, and Matlab) but free and open source. Download information and manuals are available at http://www.sagemath.org/. Included in SAGE is the group theory package GAP and GUAVA, GAP's coding theory package. All of GUAVA's functions can be accessed within SAGE.
Long-Wave Dynamics of Sea Level Variations during Indian Ocean Dipole Events
Authors: Yuan Dongliang , Liu Hailong 
Published: July 2008

Abstract
Long-wave dynamics of the interannual variations of the equatorial Indian Ocean circulation are studied using an ocean general circulation model forced by the assimilated surface winds and heat flux of the European Centre for Medium-Range Weather Forecasts. The simulation has reproduced the sea level anomalies of the Ocean Topography Experiment (TOPEX)/Poseidon altimeter observations well. The equatorial Kelvin and Rossby waves decomposed from the model simulation show that western boundary reflections provide important negative feedbacks to the evolution of the upwelling currents off the Java coast during Indian Ocean dipole (IOD) events. Two downwelling Kelvin wave pulses are generated at the western boundary during IOD events: the first is reflected from the equatorial Rossby waves and the second from the off-equatorial Rossby waves in the southern Indian Ocean. The upwelling in the eastern basin during the 1997–98 IOD event is weakened by the first Kelvin wave pulse and terminated by the second. In comparison, the upwelling during the 1994 IOD event is terminated by the first Kelvin wave pulse because the southeasterly winds off the Java coast are weak at the end of 1994.
The atmospheric intraseasonal forcing, which plays an important role in inducing Java upwelling during the early stage of an IOD event, is found to play a minor role in terminating the upwelling off the Java coast because the intraseasonal winds are either weak or absent during the IOD mature phase. The equatorial wave analyses suggest that the upwelling off the Java coast during IOD events is terminated primarily by western boundary reflections.
Association of vitamin D metabolite levels with relapse rate and disability in multiple sclerosis
Authors: Smolders J , Menheere P , Kessels A , Damoiseaux J , Hupperts R 
Published: July 2008

Background Multiple Sclerosis is associated with low serum levels of 25-hydroxyvitamin D (25(OH)D). We investigated the association between serum levels of 25(OH)D and 1,25-dihydroxyvitamin D (1,25(OH)2D), the biologically active metabolite, and clinical MS severity as expressed by EDSS-score and relapse rate. Study-design Cross-sectional study. Patients and Methods Serum samples from 267 MS patients were collected for 25(OH)D and 1,25(OH)2D measurement. Clinical MS parameters at the date of serum sampling were determined. Results: Both metabolite levels were significantly lower in the progressive forms compared to the relapsing remitting (RR)MS phenotype. In RRMS patients (disease course ≤ 5 years), high 25(OH)D levels were associated with a high chance of remaining relapse-free. Low 25(OH)D levels were associated with high EDSS-scores. 1,25(OH)2D was not directly associated with relapse rate or EDSS-score, and was dependent of age and 25(OH)D level. Conclusion Serum levels of 25(OH)D were associated with both relapse rate and disability in MS patients. These results are suggestive for a disease modulating effect of the serum concentrations of 25(OH)D on MS. The low circulating 1,25(OH)2D levels in progressive MS are due to older age and lower 25(OH)D levels. The potential consequences for vitamin D supplementation in MS will be discussed.
High-resolution whole genome tiling path array CGH analysis of CD34+ cells from patients with low-risk myelodysplastic syndromes reveals cryptic copy number alterations and predicts overall and leukemia-free survival
Authors: Starczynowski Daniel T. , Vercauteren Suzanne , Telenius Adele , Sung Sandy , Tohyama Kaoru , Brooks-Wilson Angela , Spinelli John J. , Eaves Connie J. , Eaves Allen C. , Horsman Douglas E. , Lam Wan L. , Karsan Aly 
Published: July 2008

AbstractMyelodysplastic syndromes (MDSs) pose an important diagnostic and treatment challenge because of the genetic heterogeneity and poorly understood biology of the disease. To investigate initiating genomic alterations and the potential prognostic significance of cryptic genomic changes in low-risk MDS, we performed whole genome tiling path array comparative genomic hybridization (aCGH) on CD34+ cells from 44 patients with an International Prognostic Scoring System score less than or equal to 1.0. Clonal copy number differences were detected in cells from 36 of 44 patients. In contrast, cells from only 16 of the 44 patients displayed karyotypic abnormalities. Although most patients had normal karyotype, aCGH identified 21 recurring copy number alterations. Examples of frequent cryptic alterations included gains at 11q24.2-qter, 17q11.2, and 17q12 and losses at 2q33.1-q33.2, 5q13.1-q13.2, and 10q21.3. Maintenance of genomic integrity defined as less than 3 Mb total disruption of the genome correlated with better overall survival (P = .002) and was less frequently associated with transformation to acute myeloid leukemia (P = .033). This study suggests a potential role for the use of aCGH in the clinical workup of MDS patients.