bluuebunny/crossref_metadata_2025_split huggingface dataset:
Modulation of Gamma Interferon Receptor 1 byMycobacterium tuberculosis: a Potential Immune Response Evasive Mechanism
Authors: Singhal Amit , Jaiswal Anand , Arora Virendra K. , Prasad Hanumanthappa K. 
Published: March 2007

ABSTRACTMycobacterium tuberculosisinhibits gamma interferon (IFN-γ)-mediated antimycobacterial action by adopting diverse mechanisms. IFN-γ binds to its receptor, IFN-γR, in order to initiate proper signaling. We have observed reduced surface expression levels of IFN-γ receptor 1 (IFN-γR1) in untreated pulmonary tuberculosis patients compared to those in healthy individuals (P< 0.01). Following antitubercular therapy, the expression of IFN-γR1 was restored in these patients. To delineate the mechanism by whichM. tuberculosismodulates IFN-γR1, in vitro experiments were designed, wherein the down modulation of IFN-γR1 surface expression was observed for CD14+cells in peripheral blood mononuclear cells (PBMCs) cocultured with liveM. tuberculosiscompared to that for uninfected cells (P< 0.01). No modulation of IFN-γR1 expression was observed for CD14+cells in PBMCs infected withMycobacterium smegmatis. A time-dependent decrease in IFN-γR1 mRNA expression was observed for PBMCs infected withM. tuberculosis. Similar down modulation of IFN-γR1 protein and mRNA expression in phorbol myristate acetate-differentiated THP-1 cells (pdTHP-1) byM. tuberculosiswas observed (P< 0.01). Using reporter gene analysis of 5′ deletion constructs of the IFN-γR1 gene (IFNGR1) promoter, the decrease in IFN-γR1 mRNA inM. tuberculosis-infected pdTHP-1 cells was shown to be due to the decreased transcription ofIFNGR1. By immunoblotting and electrophoretic mobility shift assays, the down regulation of stimulating protein 1 (Sp1) expression and its recruitment on the phorbol ester-responsive element of theIFNGR1promoter inM. tuberculosis-infected pdTHP-1 cells was observed. This down regulation of Sp1 in pdTHP-1 cells cocultured withM. tuberculosismay be responsible for the down regulation of IFN-γR1 expression, thereby potentially altering its receptivity to IFN-γ.
Anthrax Edema Toxin Sensitizes DBA/2J Mice to Lethal Toxin
Authors: Firoved Aaron M. , Moayeri Mahtab , Wiggins Jason F. , Shen Yuequan , Tang Wei-Jen , Leppla Stephen H. 
Published: March 2007

ABSTRACT
Anthrax toxin is made up of three separate protein components: the receptor-binding protective antigen (PA), the adenylyl cyclase edema factor (EF), and the metalloproteinase lethal factor (LF). EF and PA constitute edema toxin (ET), which causes edema when injected subcutaneously. At higher doses, ET causes severe pathologies and death in BALB/cJ mice (A. M. Firoved et al., Am. J. Pathol. 167:1309-1320, 2005). A striking effect of ET at lethal doses is adrenal necrosis. Here we show that low doses of ET (10 μg) that produce no overt signs of illness in mice still cause substantial adrenal lesions. These lesions are not associated with reduced corticosterone production; instead, ET-treated mice have increased corticosterone production. Because the resistance of mice to the other component of anthrax toxin, lethal toxin (LT; LF plus PA), has been shown to be overcome by the perturbation of the endocrine system, we hypothesized that sublethal doses of ET might sensitize LT-resistant DBA/2J mice to LT-mediated lethality. We report that a low dose of ET (5 μg) is sufficient to sensitize DBA/2J mice when given concurrently with LT. Higher doses of ET (e.g., 15 μg) given to male and female DBA/2J mice 18 h prior to LT challenge also sensitize them to LT. This study using highly purified ET and LT demonstrates how the components of anthrax toxin can work together to increase lethality.
An In Vitro Model System Used To Study Adherence and Invasion of
Francisella tularensis
Live Vaccine Strain in Nonphagocytic Cells
Authors: Lindemann Stephen R. , McLendon Molly K. , Apicella Michael A. , Jones Bradley D. 
Published: March 2007

ABSTRACT

In observing
Francisella tularensis
interactions with nonphagocytic cell lines in vitro, we noted significant adherence, invasion, and intracellular growth of the bacteria within these cells.
F. tularensis
live vaccine strain invasion of nonprofessional phagocytic cells is inhibited by cytochalasin D and nocodazole, suggesting that both the actin and microtubule cytoskeletons are important for invasion.
Shigella flexneri
Inhibits Staurosporine-Induced Apoptosis in Epithelial Cells
Authors: Clark Christina S. , Maurelli Anthony T. 
Published: March 2007

ABSTRACT

Shigella flexneri
is a facultative intracellular organism that causes bacillary dysentery. The
Shigella
IpaB protein activates caspase 1 in macrophages, which eventually leads to apoptosis. In contrast, epithelial cells infected with
Shigella
undergo a stress response but do not die. Therefore, the objective of this study was to determine if
Shigella
has the ability to inhibit apoptosis in epithelial cells. A modified gentamicin protection assay was used to investigate if HeLa cells infected with
S. flexneri
are able to resist the induction of apoptosis following treatment with 4 μM of staurosporine. Nuclear staining and immunofluorescence revealed that infected cells remained healthy while uninfected cells appeared apoptotic. Only uninfected cells had detectable levels of activated caspase 3 upon immunofluorescence, and this was verified by Western blot analysis. Despite interfering with caspase 3 activation,
Shigella
-infected cells treated with staurosporine did have cytochrome
c
release and caspase 9 activation, indicating that
Shigella
protects epithelial cells from apoptosis by inhibiting caspase 3 activation. Analysis of
S. flexneri
mutants showed that invasion and a functional type III secretion system were required to block apoptosis. In addition, a mutant with a deletion in
mxiE
, which encodes a transcriptional activator for genes induced intracellularly, failed to inhibit apoptosis. Therefore, protection of epithelial cells from apoptosis by
S. flexneri
is regulated by one or more of the bacterial genes under the control of
mxiE
. We believe that
S. flexneri
, like other pathogens, inhibits apoptosis in epithelial cells but causes apoptosis in macrophages to ensure survival inside the host.
Flow Cytometric Analysis of Adherence of
Porphyromonas gingivalis
to Oral Epithelial Cells
Authors: Pathirana Rishi D. , O'Brien-Simpson Neil M. , Visvanathan Kumar , Hamilton John A. , Reynolds Eric C. 
Published: March 2007

ABSTRACT

By using fluorescence microscopy, fluorescently labeled
Porphyromonas gingivalis
W50 was shown to adhere to oral epithelial (KB) cells as discrete cells or small cell aggregates, whereas
P. gingivalis
ATCC 33277 bound as large cell aggregates. Flow cytometric analysis showed that for
P. gingivalis
W50 there was a logarithmic relationship between the bacterial cell ratio (BCR), that is the number of bacterial cells to KB cells, and the percentage of KB cells with W50 cells attached. This percentage of KB cells with W50 attached reached a plateau of ∼84% cells at a BCR of 500:1. In contrast, a quadratic relationship was observed between BCR and the percentage of KB cells with
P. gingivalis
ATCC 33277 attached, reaching a maximum of 47% at a BCR of 100:1 but decreasing to 7% at a BCR of 1,000:1. The lower binding of ATCC 33277 at high cell concentrations was attributed to autoaggregation.
P. gingivalis
W50 cells treated with an inhibitor (
N
α-
p
-tosyl-
l
-lysine chloromethyl ketone [TLCK]) of its RgpA-Kgp proteinase-adhesin complex exhibited significantly reduced binding to KB cells than to untreated cells, suggesting a role for proteinase activity in binding to KB cells. Competitive inhibition with purified proteinase-active and TLCK-inactivated RgpA-Kgp complex significantly decreased the adherence of
P. gingivalis
W50 cells to KB cells. Furthermore, isogenic mutants of
P. gingivalis
W50 lacking the
kgp
gene product, but not the
rgpA
or
rgpB
gene products, exhibited significantly decreased adherence to KB cells compared to the wild type.
Voltammetric Methods in Metallothionein Research
Authors: Šestáková Ivana , Navrátil Tomáš 
Published: March 2007

The application of voltammetric methods using different rates of polarisation on HMDE reveal inert or labile behaviour of Cd‐ or Zn‐ complexes in the presence of excessive cadmium or zinc ions in solution. This
phenomenon was demonstrated first on the simplest phytochelatin – complex of peptide (γ‐Glu‐Cys)2Gly with cadmium, later on rabbit liver metallothioneins – Cd7MT in the presence of cadmium and Cd5Zn2MT in the presence of zinc. Voltammetric methods can distinguish between labile and inert complexes present simultaneously and therefore could elucidate their role in reactions of metal ion transfer.Another method using different rates of polarisation – elimination voltammetry with linear scan – proved that S‐tetracoordinated complexes of Cd(II) or Zn(II) in the above‐mentioned metallothioneins on HMDE are
reduced in the adsorbed state. This implies the possibility of increasing the sensitivity of identification or
determination of the above complexes. On carbon composite electrode, similar behaviour of Cd‐complexes
as on HMDE was observed using differential pulse voltammetry.
Modulation of cancer cell survival pathways using multivalent liposomal therapeutic antibody constructs
Authors: Chiu Gigi N.C. , Edwards Lincoln A. , Kapanen Anita I. , Malinen Melina M. , Dragowska Wieslawa H. , Warburton Corinna , Chikh Ghania G. , Fang Karen Y.Y. , Tan Sophia , Sy Jonathan , Tucker Catherine , Waterhouse Dawn N. , Klasa Richard , Bally Marcel B. 
Published: March 2007

Abstract
Various methods have been explored to enhance antibody-based cancer therapy. The use of multivalent antibodies or fragments against tumor antigens has generated a great deal of interest, as various cellular signals, including induction of apoptosis, inhibition of cell growth/survival, or internalization of the surface molecules, can be triggered or enhanced on extensive cross-linking of the target/antibody complex by the multivalent form of the antibody. The goal of the studies reported here was to develop multivalent antibody constructs via grafting of antibody molecules onto liposome membranes to enhance antibody activity. Using trastuzumab and rituximab as examples, up to a 25-fold increase in the antibody potency in cell viability assay was observed when the antibodies were presented in the multivalent liposome formulation. Key cell survival signaling molecules, such as phosphorylated Akt and phosphorylated p65 nuclear factor-κB, were down-regulated on treatment with multivalent liposomal trastuzumab and liposomal rituximab, respectively. Potent in vivo antitumor activity was shown for liposomal trastuzumab. The data presented here showed the potential of liposome technology to enhance the therapeutic effect of antibodies via a mechanism that modulates cell survival through clustering of the target/antibody complex. [Mol Cancer Ther 2007;6(3):844–55]
Haplotype Effects on Matrix Metalloproteinase-1 Gene Promoter Activity in Cancer Cells
Authors: Pearce Eve G. , Laxton Ross C. , Pereira Andresa C. , Ye Shu 
Published: March 2007

Abstract
Increased expression of matrix metalloproteinase-1 (MMP1) is associated with poor prognosis in cancers. Several single nucleotide polymorphisms (−1607GG&gt;G, −839G&gt;A, −755G&gt;T, −519A&gt;G, −422T&gt;A, −340C&gt;T, and 320C&gt;T) in the MMP1 gene promoter have recently been identified. In this study, we assessed the functional effects of these polymorphisms on MMP1 gene promoter activity in cell lines of melanoma (A2058 and A375), breast cancer (MCF7 and MDA-MB-231), lung cancer (A549 and H69), and colorectal cancer (HT-29, SW-620) by comparing the promoter strengths of 10 most common haplotypes deriving from these polymorphisms. In A2058 cells, the GG-G-G-A-T-T-T and GG-G-G-A-C-T haplotypes had 2-fold higher promoter activity than the GG-G-T-A-T-T-C, GG-G-G-A-A-T-T, GG-G-G-A-T-T-C, and GG-G-G-A-A-C-T haplotypes, which in turn, had 3-fold higher promoter activity than the G-G-T-A-A-C-T, G-A-T-G-T-T-T, G-A-T-G-A-C-T, and G-A-T-G-A-T-G haplotypes. In A375 and MDA-MB-231 cells, high expression haplotypes include not only the −1607GG-bearing haplotypes but also the G-A-T-G-A-T-T haplotype containing the −1607G allele. A similar trend was detected in A549 cells. In addition, in A549 cells, the GG-G-G-A-T-T-T haplotype had &gt;2-fold higher promoter activity than several other −1607GG-bearing haplotypes. In MCF7 cells, the GG-G-G-A-T-T-T and G-G-T-A-A-C-T haplotypes had 1.5- to 4-fold higher promoter activity than the other haplotypes. These results suggest that the polymorphisms exert haplotype effects on the transcriptional regulation of the MMP1 gene in cancer cells, and indicate a need to examine haplotypes rather than any single polymorphism in genetic epidemiologic studies of the MMP1 gene in cancers. (Mol Cancer Res 2007;5(3):221–7)
IFI16 in Human Prostate Cancer
Authors: Alimirah Fatouma , Chen Jianming , Davis Francesca J. , Choubey Divaker 
Published: March 2007

Abstract
Increased expression of IFI16 protein (encoded by the IFI16 gene) in normal human prostate epithelial cells is associated with cellular senescence-associated cell growth arrest. Consistent with a role for IFI16 protein in cellular senescence, the expression of IFI16 protein is either very low or not detectable in human prostate cancer cell lines. We now report that treatment of DU-145 and LNCaP prostate cancer cell lines with histone deacetylase inhibitor trichostatin A (TSA) or CGK1026 resulted in transcriptional activation of the IFI16 gene. The induction of IFI16 protein in LNCaP cells was dependent on the duration of TSA treatment. Furthermore, TSA treatment of LNCaP cells up-regulated the expression of Janus-activated kinase 1 protein kinase and modulated the transcription of certain IFN-activatable genes. However, overexpression of exogenous Janus-activated kinase 1 protein in LNCaP cells and treatment of cells with IFNs (α and γ) did not increase the expression of IFI16. Instead, the transcriptional activation of IFI16 gene by TSA treatment of LNCaP cells was dependent on transcriptional activation by c-Jun/activator protein-1 transcription factor. Importantly, increased expression of IFI16 in LNCaP cells was associated with decreases in the expression of androgen receptor and apoptosis of cells. Conversely, knockdown of IFI16 expression in TSA-treated LNCaP cells increased androgen receptor protein levels with concomitant decreases in apoptosis. Together, our observations provide support for the idea that histone deacetylase–dependent transcriptional silencing of the IFI16 gene in prostate epithelial cells contributes to the development of prostate cancer. (Mol Cancer Res 2007;5(3):251–9)
Estimates of Uncertainty in Predictions of Global Mean Surface Temperature
Authors: Kettleborough J. A. , Booth B. B. B. , Stott P. A. , Allen M. R. 
Published: March 2007

Abstract
A method for estimating uncertainty in future climate change is discussed in detail and applied to predictions of global mean temperature change. The method uses optimal fingerprinting to make estimates of uncertainty in model simulations of twentieth-century warming. These estimates are then projected forward in time using a linear, compact relationship between twentieth-century warming and twenty-first-century warming. This relationship is established from a large ensemble of energy balance models.
By varying the energy balance model parameters an estimate is made of the error associated with using the linear relationship in forecasts of twentieth-century global mean temperature. Including this error has very little impact on the forecasts. There is a 50% chance that the global mean temperature change between 1995 and 2035 will be greater than 1.5 K for the Special Report on Emissions Scenarios (SRES) A1FI scenario. Under SRES B2 the same threshold is not exceeded until 2055. These results should be relatively robust to model developments for a given radiative forcing history.
Intraseasonal Atmospheric Variability in the Extratropics and Its Relation to the Onset of Tropical Pacific Sea Surface Temperature Anomalies
Authors: Anderson Bruce T. 
Published: March 2007

Abstract
Previous research has shown that seasonal-mean boreal winter variations in the subtropical/extratropical sea level pressure and wind stress fields over the central North Pacific are significantly related to the state of the El Niño–Southern Oscillation (ENSO) 12–15 months later. Results presented in this note indicate that boreal winter ENSO events are also preceded by increased intraseasonal variance in the antecedent boreal winter atmospheric circulation patterns over the extratropical central North Pacific as well. Low (high) surface pressure anomalies associated with intraseasonal variability in this region are related to intraseasonal wind stress anomalies that represent a weakening (strengthening) of the trade winds over both the north and south subtropical/tropical Pacific. There is also a concurrent increase (decrease) in the central and eastern subtropical North Pacific sea surface temperatures that projects onto the seasonal-mean SST anomalies that precede mature ENSO events by 9–12 months. Overall these results suggest that similar to seasonal-mean subtropical surface pressure and wind stress fields, enhanced transient variability in the midlatitudes can subsequently induce changes in the atmospheric and oceanic structure of the tropical Pacific that may serve as a precursor to ENSO variability.
Addressing the Issue of Systematic Errors in a Regional Climate Model
Authors: Misra Vasubandhu 
Published: March 2007

Abstract
A methodology is proposed in which a few prognostic variables of a regional climate model (RCM) are strongly constrained at certain wavelengths to what is prescribed from the bias-corrected atmospheric general circulation model (AGCM; driver model) integrations. The goal of this strategy is to reduce the systematic errors in a RCM that mainly arise from two sources: the lateral boundary conditions and the RCM errors. Bias correction (which essentially corrects the climatology) of the forcing from the driving model addresses the former source while constraining the solution of the RCM beyond certain relatively large wavelengths in the regional domain [also termed as scale-selective bias correction (SSBC)] addresses the latter source of systematic errors in RCM. This methodology is applied to experiments over the South American monsoon region. It is found that the combination of bias correction and SSBC on the nested variables of divergence, vorticity, and the log of surface pressure of an RCM yields a major improvement in the simulation of the regional climate variability over South America from interannual to intraseasonal time scales. The basis for such a strategy is derived from a systematic empirical approach that involved over 100 regional seasonal climate integrations.
Climate Response to Basin-Scale Warming and Cooling of the North Atlantic Ocean
Authors: Sutton Rowan T. , Hodson Daniel L. R. 
Published: March 2007

Abstract
Using experiments with an atmospheric general circulation model, the climate impacts of a basin-scale warming or cooling of the North Atlantic Ocean are investigated. Multidecadal fluctuations with this pattern were observed during the twentieth century, and similar variations—but with larger amplitude—are believed to have occurred in the more distant past. It is found that in all seasons the response to warming the North Atlantic is strongest, in the sense of highest signal-to-noise ratio, in the Tropics. However there is a large seasonal cycle in the climate impacts. The strongest response is found in boreal summer and is associated with suppressed precipitation and elevated temperatures over the lower-latitude parts of North and South America. In August–September–October there is a significant reduction in the vertical shear in the main development region for Atlantic hurricanes. In winter and spring, temperature anomalies over land in the extratropics are governed by dynamical changes in circulation rather than simply reflecting a thermodynamic response to the warming or cooling of the ocean.
The tropical climate response is primarily forced by the tropical SST anomalies, and the major features are in line with simple models of the tropical circulation response to diabatic heating anomalies. The extratropical climate response is influenced both by tropical and higher-latitude SST anomalies and exhibits nonlinear sensitivity to the sign of the SST forcing. Comparisons with multidecadal changes in sea level pressure observed in the twentieth century support the conclusion that the impact of North Atlantic SST change is most important in summer, but also suggest a significant influence in lower latitudes in autumn and winter.
Significant climate impacts are not restricted to the Atlantic basin, implying that the Atlantic Ocean could be an important driver of global decadal variability. The strongest remote impacts are found to occur in the tropical Pacific region in June–August and September–November. Surface anomalies in this region have the potential to excite coupled ocean–atmosphere feedbacks, which are likely to play an important role in shaping the ultimate climate response.
Extratropical Influences on the El Niño–Southern Oscillation through the Late Quaternary
Authors: Bush Andrew B. G. 
Published: March 2007

Abstract
A sequence of numerical simulations with a coupled atmosphere–ocean general circulation model configured for particular times during the late Quaternary shows that simulated El Niño–Southern Oscillation (ENSO) events decrease in frequency from the Last Glacial Maximum (LGM) to today, in accord with linear stability theory, but increase in amplitude. Diagnostic analyses indicate that altered momentum fluxes from midlatitude eddy activity caused by changes in orbital forcing (in the Holocene) and topographic forcing (at the LGM) regulate the strength of climatological easterlies and therefore affect both the tropical mean state and the characteristics of interannual variability. The fact that climatic teleconnections associated with paleo-ENSO are fundamentally different during these times suggests a way in which to reconcile some of the existing discrepancies amongst interpretations of proxy records and numerical paleoclimate simulations.
Le croire et le cru: Les appartenances religieuses au sein du christianisme européen revisitées à partir des travaux de Michel de Certeau
Authors: Bastenier Albert 
Published: March 2007

English In order to better understand the developments taking place within European Christianity, it seems worth our while to take another look at the notion of religious belonging, one which turns out to be more complex than it seemed at first glance. The flow of affiliations and disaffiliations it sets in motion might well be reinterpreted as the ambivalent expression of the engagements and disengagements associated with the construction of a common world. In this connection, the works of the historian, M. de Certeau, leading to an anthropology of belief, offer a significant contribution to the development of a theory of belonging. French En vue de mieux comprendre les évolutions en cours au sein du christianisme européen, il y à avantage a revisiter la notion d'appartenance religieuse qui s'avère plus complexe qu'il n'y paraît. Le mouvement dles affiliations et désafflliations qu'elle met en jeu doit être relu comme l'expression ambivalente des engagements et cles dégagements associés ci la construction d'un monde commun. À cet égard, les travaux d'historien de M. de Certeau, qui débouchent dans une anthropologie du croire, apportent un appui significatif dlans l'élaboration d'une théorie de l'appartenance.