bluuebunny/crossref_metadata_2025_split huggingface dataset:
Roseophage RDJLΦ1, Infecting the Aerobic Anoxygenic Phototrophic BacteriumRoseobacter denitrificansOCh114
Authors: Zhang Yongyu , Jiao Nianzhi 
Published: January 2009

ABSTRACTA marine roseophage RDJLΦ1 lytically infectingRoseobacter denitrificansOCh114 was isolated and characterized. RDJLΦ1 can package several host cellular proteins into its virions, and its DNA is refractory to several commonly used restriction enzymes. This paper presents the first report of a bacteriophage isolated from the aerobic anoxygenic phototrophic bacteria.
Microbial Conversion of Glycerol to 1,3-Propanediol by an Engineered Strain of
Escherichia coli
Authors: Tang Xueming , Tan Yongsong , Zhu Hong , Zhao Kai , Shen Wei 
Published: January 2009

ABSTRACT

In an effort to improve industrial production of 1,3-propanediol (1,3-PD), we engineered a novel polycistronic operon under the control of the temperature-sensitive lambda phage P
L
P
R
promoter regulated by the
c
I
ts
857 repressor and expressed it in
Escherichia coli
K-12 ER2925. The genes for the production of 1,3-PD in
Clostridium butyricum
,
dhaB1
and
dhaB2
, which encode the vitamin B
12
-independent glycerol dehydratase DhaB1 and its activating factor, DhaB2, respectively, were tandemly arrayed with the
E. coli yqhD
gene, which encodes the 1,3-propanediol oxidoreductase isoenzyme YqhD, an NADP-dependent dehydrogenase that can directly convert glycerol to 1,3-PD. The microbial conversion of 1,3-PD from glycerol by this recombinant
E. coli
strain was studied in a two-stage fermentation process. During the first stage, a novel high-cell-density fermentation step, there was significant cell growth and the majority of the metabolites produced were organic acids, mainly acetate. During the second stage, glycerol from the fresh medium was rapidly converted to 1,3-PD following a temperature shift from 30°C to 42°C. The by-products were mainly pyruvate and acetate. During this two-stage process, the overall 1,3-PD yield and productivity reached 104.4 g/liter and 2.61 g/liter/h, respectively, and the conversion rate of glycerol to 1,3-PD reached 90.2% (g/g). To our knowledge, this is the highest reported yield and productivity efficiency of 1,3-PD with glycerol as the sole source of carbon. Furthermore, the overall fermentation time was only 40 h, shorter than that of any other reports.
Host-Pathogen Interactions ofActinobacillus pleuropneumoniaewith Porcine Lung and Tracheal Epithelial Cells
Authors: Auger Eliane , Deslandes Vincent , Ramjeet Mahendrasingh , Contreras Irazù , Nash John H. E. , Harel Josée , Gottschalk Marcelo , Olivier Martin , Jacques Mario 
Published: January 2009

ABSTRACTHost-pathogen interactions are of great importance in understanding the pathogenesis of infectious microorganisms. We developed in vitro models to study the host-pathogen interactions of porcine respiratory tract pathogens using two immortalized epithelial cell lines, namely, the newborn pig trachea (NPTr) and St. Jude porcine lung (SJPL) cell lines. We first studied the interactions ofActinobacillus pleuropneumoniae, an important swine pathogen, using these models. Under conditions where cytotoxicity was absent or low, we showed thatA. pleuropneumoniaeadheres to both cell lines, stimulating the induction of NF-κB. The NPTr cells consequently secrete interleukin 8, while the SJPL cells do not, since they are deprived of the NF-κB p65 subunit. Cell death ultimately occurs by necrosis, not apoptosis. The transcriptomic profile ofA. pleuropneumoniaewas determined after contact with the porcine lung epithelial cells by using DNA microarrays. Genes such astadBandrcpA, members of a putative adhesin locus, and a gene whose product has high homology to the Hsf autotransporter adhesin ofHaemophilus influenzaewere upregulated, as were the genespgaBC, involved in biofilm biosynthesis, while capsular polysaccharide-associated genes were downregulated. The in vitro models also proved to be efficient with other swine pathogens, such asActinobacillus suis,Haemophilus parasuis, andPasteurella multocida. Our results demonstrate that interactions ofA. pleuropneumoniaewith host epithelial cells seem to involve complex cross talk which results in regulation of various bacterial genes, including some coding for putative adhesins. Furthermore, our data demonstrate the potential of these in vitro models in studying the host-pathogen interactions of other porcine respiratory tract pathogens.
Transmission ofToxoplasma gondiifrom Infected Dendritic Cells to Natural Killer Cells
Authors: Persson Catrine M. , Lambert Henrik , Vutova Polya P. , Dellacasa-Lindberg Isabel , Nederby Joanna , Yagita Hideo , Ljunggren Hans-Gustaf , Grandien Alf , Barragan Antonio , Chambers Benedict J. 
Published: January 2009

ABSTRACTThe obligate intracellular parasiteToxoplasma gondiican actively infect any nucleated cell type, including cells from the immune system. In the present study, we observed that a large number of natural killer (NK) cells were infected byT. gondiiearly after intraperitoneal inoculation of parasites into C57BL/6 mice. Interestingly, one mechanism of NK cell infection involved NK cell-mediated targeting of infected dendritic cells (DC). Perforin-dependent killing of infected DC led to active egress of infectious parasites that rapidly infected adjacent effector NK cells. Infected NK cells were not efficiently targeted by other NK cells. These results suggest that rapid transfer ofT. gondiifrom infected DC to effector NK cells may contribute to the parasite's sequestration and shielding from immune recognition shortly after infection.
Critical Role of NOD2 in Regulating the Immune Response to
Staphylococcus aureus
Authors: Deshmukh Hitesh S. , Hamburger James B. , Ahn Sun Hee , McCafferty Dewey G. , Yang Suxiao R. , Fowler Vance G. 
Published: January 2009

ABSTRACT

NOD2 (the nucleotide-binding oligomerization domain containing protein 2) is known to be involved in host recognition of bacteria, although its role in the host response to
Staphylococcus aureus
infection is unknown. NOD2-deficient (
Nod2

−/−

) mice and wild-type (WT) littermate controls were injected intraperitoneally with
S. aureus
suspension (10
7
bacteria/g of body weight), and their survival was monitored. Cultured bone marrow-derived neutrophils were harvested from
Nod2

−/−

and WT mice and tested for cytokine production and phagocytosis. Compared to WT mice,
Nod2

−/−

mice were significantly more susceptible to
S. aureus
infection (median survival of 1.5 days versus >5 days;
P
= 0.003) and had a significantly higher bacterial tissue burden. Cultured bone marrow-derived neutrophils from
Nod2

−/−

and WT mice had similar levels of peritoneal neutrophil recruitment and intracellular killing, but bone marrow-derived neutrophils from
Nod2

−/−

mice had significantly reduced ability to internalize fluorescein-labeled
S. aureus. Nod2

−/−

mice had significantly higher levels of Th1-derived cytokines in serum (tumor necrosis factor alpha, gamma interferon, and interleukin-2 [IL-2]) compared to WT mice, whereas the levels of Th2-derived cytokines (IL-1β, IL-4, IL-6, and IL-10) were similar in
Nod2

−/−

and WT mice. Thus, mice deficient in NOD2 are more susceptible to
S. aureus
. Increased susceptibility is due in part to defective neutrophil phagocytosis, elevated serum levels of Th1 cytokines, and a higher bacterial tissue burden.
LiveBorrelia burgdorferiSpirochetes Elicit Inflammatory Mediators from Human Monocytes via the Toll-Like Receptor Signaling Pathway
Authors: Dennis Vida A. , Dixit Saurabh , O'Brien Shannon M. , Alvarez Xavier , Pahar Bapi , Philipp Mario T. 
Published: January 2009

ABSTRACTWe investigated the mechanisms that lead to the production of proinflammatory mediators by human monocytes when these cells are exposed in vitro to liveBorrelia burgdorferispirochetes. We first focused on myeloid differentiation primary response protein 88 (MyD88), an adapter molecule that is essential in the Toll-like receptor (TLR) pathway. Real-time PCR, flow cytometry, and confocal microscopy experiments revealed that MyD88 was maximally expressed in THP-1 cells after 24-h stimulation of these cells with liveB. burgdorferi. Silencing of theMYD88gene by using small interfering RNA resulted in 24%, 35%, and 84% down-modulation of the production of tumor necrosis factor alpha (TNF-α), interleukin-8 (IL-8), and IL-6, respectively, in THP-1 cells stimulated with liveB. burgdorferi. Specific silencing of theTLR1,TLR2, orTLR5gene by RNA interference further revealed that silencing of theTLR1andTLR2genes alone or combined, but not theTLR5gene, caused a downregulation of IL-6, IL-8, and TNF-α in liveB. burgdorferi-stimulated THP-1 cells. Overall, similar results were obtained for THP-1 cells stimulated with purified lipoproteins. Our results indicate that the TLR pathway mediates, at least in part, the release of inflammatory mediators in human monocytes stimulated with liveB. burgdorferispirochetes and furthermore suggest that the TLR-dependent interaction between these cells and live spirochetes is mediated by spirochetal lipoproteins but not by flagellin.
Immunoglobulin G Subclass-Specific Responses against
Plasmodium falciparum
Merozoite Antigens Are Associated with Control of Parasitemia and Protection from Symptomatic Illness
Authors: Stanisic Danielle I. , Richards Jack S. , McCallum Fiona J. , Michon Pascal , King Christopher L. , Schoepflin Sonja , Gilson Paul R. , Murphy Vincent J. , Anders Robin F. , Mueller Ivo , Beeson James G. 
Published: January 2009

ABSTRACT

Substantial evidence indicates that antibodies to
Plasmodium falciparum
merozoite antigens play a role in protection from malaria, although the precise targets and mechanisms mediating immunity remain unclear. Different malaria antigens induce distinct immunoglobulin G (IgG) subclass responses, but the importance of different responses in protective immunity from malaria is not known and the factors determining subclass responses in vivo are poorly understood. We examined IgG and IgG subclass responses to the merozoite antigens MSP1-19 (the 19-kDa C-terminal region of merozoite surface protein 1), MSP2 (merozoite surface protein 2), and AMA-1 (apical membrane antigen 1), including different polymorphic variants of these antigens, in a longitudinal cohort of children in Papua New Guinea. IgG1 and IgG3 were the predominant subclasses of antibodies to each antigen, and all antibody responses increased in association with age and exposure without evidence of increasing polarization toward one subclass. The profiles of IgG subclasses differed somewhat for different alleles of MSP2 but not for different variants of AMA-1. Individuals did not appear to have a propensity to make a specific subclass response irrespective of the antigen. Instead, data suggest that subclass responses to each antigen are generated independently among individuals and that antigen properties, rather than host factors, are the major determinants of IgG subclass responses. High levels of AMA-1-specific IgG3 and MSP1-19-specific IgG1 were strongly predictive of a reduced risk of symptomatic malaria and high-density
P. falciparum
infections. However, no antibody response was significantly associated with protection from parasitization per se. Our findings have major implications for understanding human immunity and for malaria vaccine development and evaluation.
Identification of a Pneumococcal Glycosidase That Modifies O-Linked Glycans
Authors: Marion Carolyn , Limoli Dominique H. , Bobulsky Gregory S. , Abraham Jessica L. , Burnaugh Amanda M. , King Samantha J. 
Published: January 2009

ABSTRACTColonization of the airway byStreptococcus pneumoniaeis typically asymptomatic; however, progression of bacteria beyond the oronasopharynx can cause diseases including otitis media and pneumonia. The mechanisms by whichS. pneumoniaeestablishes and maintains colonization remain poorly understood. Both N-linked and O-linked glycans are abundant in the airway. Our previous research demonstrated thatS. pneumoniaecan sequentially deglycosylate N-linked glycans and suggested that this modification of sugar structures may aid in colonization. There is published evidence thatS. pneumoniaeexpresses a secreted O-glycosidase that cleaves galactose β1-3N-acetylgalactosamine (Galβ1-3GalNAc) from core-1 O-linked glycans; however, the biological function of this enzyme has not previously been determined. We established that the activity is not secreted but is instead surface associated in a sortase-dependent manner. Genome analysis revealed an open reading frame predicted to encode a sortase-dependent surface protein with sequence similarity to the O-glycosidase ofBifidobacterium longum. Deletion of this pneumococcal open reading frame confirmed that this gene encodes an O-glycosidase. Experiments using a model glycoconjugate demonstrated that this O-glycosidase, together with the neuraminidase NanA, is required forS. pneumoniaeto cleave sialylated core-1 O-linked glycans. The ability of the O-glycosidase mutant to cleave this glycan structure was restored by both genetic complementation and the addition of O-glycosidase. The mutant showed a reduction in adherence to human airway epithelial cells and a significantly decreased ability to colonize the upper respiratory tract, suggesting that cleavage of core-1 O-linked glycans enhances the ability ofS. pneumoniaeto colonize the human airway.
Pore-Forming Activity of Alpha-Toxin Is Essential for
Clostridium septicum
-Mediated Myonecrosis
Authors: Kennedy Catherine L. , Lyras Dena , Cordner Leanne M. , Melton-Witt Jody , Emmins John J. , Tweten Rodney K. , Rood Julian I. 
Published: January 2009

ABSTRACT

Clostridium septicum
alpha-toxin is a β-barrel pore-forming cytolysin that is functionally similar to aerolysin. Residues important in receptor binding, oligomerization, and pore formation have been identified; however, little is known about the activity of the toxin in an infection, although it is essential for disease. We have now shown that deletion of a small portion of the transmembrane domain, so that the toxin is no longer able to form pores, completely abrogates its ability to contribute to disease, as does replacement of the sole cysteine residue with leucine. However, although previous biochemical and cytotoxicity assays clearly indicated that mutations in residues important in oligomerization, binding, and prepore conversion greatly reduced activity or rendered the toxin inactive, once the mutated toxins were overexpressed by the natural host in the context of an infection it was found they were able to cause disease in a mouse model of myonecrosis. These results highlight the importance of testing the activity of virulence determinants in the normal host background and in an infectious disease context and provide unequivocal evidence that it is the ability of alpha-toxin to form a pore that confers its toxicity in vivo.
Temporal sequence of greyscale ultrasound changes and their relationship with neovascularity and pain in the patellar tendon
Authors: Malliaras P , Purdam C , Maffulli N , Cook J 
Published: January 2009

ObjectiveUltrasound (US) imaging has revealed distinct types of greyscale abnormalities in the patellar and Achilles tendons, including diffusely thickened tendons and tendons containing a hypoechoic region. The relationship between these greyscale abnormalities and their clinical relevance is unknown. This study investigated the temporal sequence in greyscale abnormalities as well as the relationship between greyscale abnormalities, Doppler flow and pain.MethodsPatellar tendon pain (single leg decline squat test) and ultrasound imaging (greyscale (normal, diffuse thickening, hypoechoic), presence of Doppler flow) were assessed bilaterally among 58 volleyball players at monthly intervals during a 5-month season. The probability of transition between the greyscale ultrasound groups was calculated for each month and totalled over the season (prospective) and the relationship between these groups and the presence and intensity of pain and the presence of Doppler flow were investigated (cross-sectional investigation).ResultsTendons with normal US were more likely to transition to diffuse thickening than to a hypoechoic region. Tendons containing a hypoechoic region were more likely to transition to diffuse thickening rather than to a normal US appearance. Hypoechoic regions were more likely to be painful (59%) and contain Doppler flow (42%) than tendons with diffuse thickening (pain in 43% and Doppler flow in 6%).ConclusionsThe transitions identified between normal, diffusely thickened tendons and those containing a hypoechoic region suggests that these greyscale US changes may represent different phases of tendon pathology. Tendons containing a hypoechoic region are more likely to be painful and contain Doppler flow than diffusely thickened tendons.
Anaplastic nephroblastomas express transketolase-like enzyme 1
Authors: Wu H-T , Allie N , Myer L , Govender D 
Published: January 2009

Aim:Transketolase-like enzyme 1 (TKTL1) is a glycolytic enzyme that has been found to be upregulated in several tumours, and it is associated with tumour progression. Nephroblastoma is the commonest paediatric renal malignancy and has a good prognosis except for those with anaplasia. To the best of the authors’ knowledge, the expression of TKTL1 in nephroblastomas has not been studied before and the aim of this study was to compare the immunoexpression of TKTL1 in anaplastic and non-anaplastic nephroblastomas.Methods:Twenty-eight patients who had nephrectomies for nephroblastomas were studied. Archival formalin-fixed paraffin-wax-embedded tissue sections were stained with monoclonal TKTL1 antibody.Results:Six of the 15 anaplastic nephroblastomas showed staining in 80–100% of the tumour (p = 0.36). None of the 13 non-anaplastic nephroblastomas showed TKTL1 staining in >80% of the tumour.Conclusion:TKTL1 expression is associated with the presence of anaplasia and may be a mechanism via which anaplastic tumour cells thrive under different conditions. Glycolytic inhibitors may play a role in anaplastic nephroblastomas.
Climate change and ecosystem response in the northern Columbia River basin — A paleoenvironmental perspective
Authors: Walker Ian R. , Pellatt Marlow G. 
Published: January 2009

A comprehensive review of Holocene paleoenvironmental data has been prepared, providing the basis for evaluating natural variability in climate and ecosystem dynamics in the northern Columbia River basin. The paleoenvironmental record reveals four major climatic shifts and a number of less well-defined climatic changes throughout the Holocene. The major climate changes are (1) a cool or cold, late-glacial climate at the end of the last glaciation (>11 500 cal. year BP), (2) an interval of drought and maximum summer warmth during the early Holocene (ca. 10500 to 8000 cal. year BP), (3) a mid-Holocene trend towards a cooler, more moist climate (ca. 8000 to ca. 4000 cal. year BP), and (4) a relatively stable climate persisting from ca. 4000 cal. year BP until the arrival of European settlers. Air temperatures have warmed by about 1 °C over the past century. Minor climate events that are emerging as global in nature include Little Ice Age (1200–150 BP) conditions, and a late Holocene cool wet period (3500–2500 BP). These are observed in some study sites examined in this paper and may be related to large-scale cycles of 2800–2000 and 1500 years. A discussion of changing atmospheric circulation patterns, and the causes of long-term climatic change are included, together with a discussion of the implications of the paleoenvironmental record for understanding future climate, and the likely response of communities and ecosystems.
Brown Norway rats show impaired nNOS-mediated information transfer in renal autoregulationThis article is part of a Special Issue on Information Transfer in the Microcirculation.
Authors: Wang Xuemei , Cupples William A. 
Published: January 2009

Nonselective inhibition of NO synthase (NOS) augments myogenic autoregulation of renal blood flow (RBF) and profoundly reduces RBF. Previously in Wistar rats, we showed that augmented autoregulation, but not vasoconstriction, is duplicated by intrarenal inhibition of neuronal NOS (nNOS), whereas intrarenal inhibition of inducible NOS (iNOS) has no effect on RBF or on RBF dynamics. Thus macula densa nNOS transfers information from tubuloglomerular feedback to the afferent arteriole. This information flow requires that macula densa nNOS can sufficiently alter ambient NO concentration, that is, that endothelial NOS (eNOS) and iNOS do not alter local NO concentration. Because the Brown Norway rat often shows exaggerated responses to NOS inhibition and has peculiarities of renal autoregulation that are related to NO, we used this strain to study systemic and renal vascular responses to NOS inhibition. The first experiment showed transient blood pressure reduction by bolus i.v. acetylcholine that was dose-dependent in both strains and substantially prolonged in Brown Norway rats. The depressor response decayed more rapidly after nonselective NOS inhibition and the difference between strains was lost, indicating a greater activity of eNOS in Brown Norway rats. In Brown Norway rats, selective inhibition of iNOS reduced RBF (–16% ± 7%) and augmented myogenic autoregulation, whereas nNOS inhibition reduced RBF (–25% ± 4%) and did not augment myogenic autoregulation. The significant responses to intrarenal iNOS inhibition, the reduced modulation of autoregulation by nNOS inhibition, and the enhanced endothelial depressor response suggest that physiological signalling by NO within the kidney is impaired in Brown Norway rats because of irrelevant or inappropriate input of NO by eNOS and iNOS.
Data fusion
Authors: Bleiholder Jens , Naumann Felix 
Published: January 2009

The development of the Internet in recent years has made it possible and useful to access many different information systems anywhere in the world to obtain information. While there is much research on the integration of heterogeneous information systems, most commercial systems stop short of the actual integration of available data. Data fusion is the process of fusing multiple records representing the same real-world object into a single, consistent, and clean representation.
This article places data fusion into the greater context of data integration, precisely defines the goals of data fusion, namely, complete, concise, and consistent data, and highlights the challenges of data fusion, namely, uncertain and conflicting data values. We give an overview and classification of different ways of fusing data and present several techniques based on standard and advanced operators of the relational algebra and SQL. Finally, the article features a comprehensive survey of data integration systems from academia and industry, showing if and how data fusion is performed in each.
PP2A regulates ionizing radiation–induced apoptosis through Ser46 phosphorylation of p53
Authors: Mi Jun , Bolesta Elzbieta , Brautigan David L. , Larner James M. 
Published: January 2009

Abstract
In response to ionizing radiation, p53 plays a critical role in regulating DNA repair and apoptosis. Among multiple phosphorylation sites, evidence suggests that Ser46 promotes apoptotic cell death through mitochondrial outer membrane permeabilization (MOMP) and subsequent activation of the caspase 7–PARP pathway. Therefore, we investigated which phosphatase regulates Ser46 after ionizing radiation, reasoning that the responsible phosphatase should be a target for radiosensitization. We determined that both inhibition of PP2A by the cell-permeable inhibitor calyculin A and knockdown of PP2A by RNAi (a) enhanced Ser46 phosphorylation in p53 and (b) induced coincident caspase 7 and PARP cleavage in response to ionizing radiation. Furthermore, mutation of p53 Ser46 to Ala attenuated ionizing radiation–induced apoptotic signaling. Consequently, we concluded that PP2A regulates ionizing radiation–induced apoptotic signaling through dephosphorylation of p53 Ser46. [Mol Cancer Ther 2009;8(1):135–40]