bluuebunny/crossref_metadata_2025_split huggingface dataset:
Investigation of the dosimetric accuracy of the isocenter shifting method in prostate cancer patients with and without hip prostheses
Authors: Hwang Andrew B. , Kinsey Erica , Xia Ping 
Published: October 2009

Purpose:The use of image guided radiation therapy (IGRT) enables compensation for prostate movement by shifting the treatment isocenter to track the prostate on a daily basis. Although shifting the isocenter can alter the source to skin distances (SSDs) and the effective depth of the target volume, it is commonly assumed that these changes have a negligible dosimetric effect, and therefore, the number of monitor units delivered is usually not adjusted. However, it is unknown whether or not this assumption is valid for patient with hip prostheses, which frequently contain high density materials.Methods:The authors conducted a retrospective study to investigate dosimetric effect of the isocenter shifting method for prostate patients with and without hip prostheses. For each patient, copies of the prostate volume were shifted by up to 1.5 cm from the original position to simulate prostate movement in 0.5 cm increments. Subsequently, 12 plans were created for each patient by creating a copy of the original plan for each prostate position with the isocenter shifted to track the position of the shifted prostate. The dose to the prostate was then recalculated for each plan. For patients with hip prostheses, plans were created both with and without lateral beam angles entering through the prostheses.Results:Without isocenter shifting to compensate for prostate motion of 1.5 cm, the dose to the 95% of the prostate changed by an average of 30% and by up to 64%. This was reduced to less than 3% with the isocenter shifting method. It was found that for patients with hip prostheses, this technique worked best for treatment plans that avoided beam angles passing through the prostheses.Conclusions:The results demonstrated that the isocenter shifting method can accurately deliver dose to the prostate even in patients with hip prostheses.
Quorum Sensing Negatively Regulates Hemolysin Transcriptionally and Posttranslationally in
Vibrio cholerae
Authors: Tsou Amy M. , Zhu Jun 
Published: October 2009

ABSTRACT

Recent work has shown that in addition to cholera toxin (CT) and the toxin-coregulated pilus (TCP), other cytotoxic proteins in
Vibrio cholerae
also cause disease symptoms, and this is particularly evident in strains lacking CT. One such protein is the hemolysin encoded by
hlyA
. Here we show that, like CT and TCP, HlyA is repressed by the quorum-sensing-regulated transcription factor HapR. This repression occurs on two levels: one at the transcriptional level that is independent of the metalloprotease HapA and one at the posttranslational level that is mediated by HapA. The transcriptional regulation is significantly more apparent on solid media than in liquid cultures. This is the first time that hemolysis has been shown to be directly regulated by quorum sensing in
V. cholerae
, and it is interesting that, like other virulence factors, HlyA is also repressed by HapR, which is expressed late in infection.
Functional Characterization ofBorrelia spielmaniiOuter Surface Proteins That Interact with Distinct Members of the Human Factor H Protein Family and with Plasminogen
Authors: Seling Annekatrin , Siegel Corinna , Fingerle Volker , Jutras Brandon L. , Brissette Catherine A. , Skerka Christine , Wallich Reinhard , Zipfel Peter F. , Stevenson Brian , Kraiczy Peter 
Published: October 2009

ABSTRACTAcquisition of complement regulator factor H (CFH) and factor H-like protein 1 (CFHL1) from human serum enablesBorrelia spielmanii, one of the etiological agents of Lyme disease, to evade complement-mediated killing by the human host. Up to three distinct complement regulator-acquiring surface proteins (CRASPs) may be expressed by serum-resistantB. spielmanii, each exhibiting an affinity for CFH and/or CFHL1. Here, we describe the functional characterization of the 15-kDa CRASPs ofB. spielmanii, members of the polymorphic Erp (OspE/F-related) protein family, that bind two distinct host complement regulators, CFH and factor H-related protein 1 (CFHR1), but not CFHL1. CFH bound to theB. spielmaniiCRASPs maintained cofactor activity for factor I-mediated C3b inactivation. Three naturally occurring alleles of this protein bound CFH and CFHR1 while a fourth natural allele could not. Comparative sequence analysis of these protein alleles identified a single amino acid, histidine-79, as playing a significant role in CFH/CFHR1 binding, with substitution by an arginine completely abrogating ligand binding. The mutation of His-79 to Arg did not inhibit binding of plasminogen, another known ligand of this group of borrelial outer-surface proteins.
Production of Reactive Oxygen Species Is Turned On and Rapidly Shut Down in Epithelial Cells Infected with
Chlamydia trachomatis
Authors: Boncompain Gaëlle , Schneider Benoît , Delevoye Cédric , Kellermann Odile , Dautry-Varsat Alice , Subtil Agathe 
Published: October 2009

ABSTRACT

Reactive oxygen species (ROS) are many-faceted compounds involved in cell defense against pathogens, as well as in cell signaling. Their involvement in the response to infection in epithelial cells remains poorly documented. Here, we investigated the production of ROS during infection with
Chlamydia trachomatis
, a strict intracellular pathogen, in HeLa cells.
C. trachomatis
induced a transient increase in the ROS level within a few hours, followed by a return to basal level 9 hours after infection. At this time point, the host enzyme dedicated to ROS production, NADPH oxidase, could no longer be activated by external stimuli, such as interleukin-1β. In addition, Rac, a regulatory subunit of the NADPH oxidase complex, was relocated to the membrane of the compartment in which the bacteria develop, the inclusion, while other subunits were not. Altogether, these results indicate that
C. trachomatis
infection elicits the production of ROS and that the bacteria rapidly target the activity of NADPH oxidase to shut it down. Prevention of ROS production at the onset of the bacterial developmental cycle might delay the host response to infection.
Prime-Boost Immunization with Adenoviral and Modified Vaccinia Virus Ankara Vectors Enhances the Durability and Polyfunctionality of Protective Malaria CD8
+
T-Cell Responses
Authors: Reyes-Sandoval Arturo , Berthoud Tamara , Alder Nicola , Siani Loredana , Gilbert Sarah C. , Nicosia Alfredo , Colloca Stefano , Cortese Riccardo , Hill Adrian V. S. 
Published: October 2009

ABSTRACT

Protection against liver-stage malaria relies on the induction of high frequencies of antigen-specific CD8
+
T cells. We have previously reported high protective levels against mouse malaria, albeit short-lived, by a single vaccination with adenoviral vectors coding for a liver-stage antigen (ME.TRAP). Here, we report that prime-boost regimens using modified vaccinia virus Ankara (MVA) and adenoviral vectors encoding ME.TRAP can enhance both short- and long-term sterile protection against malaria. Protection persisted for at least 6 months when simian adenoviruses AdCh63 and AdC9 were used as priming vectors. Kinetic analysis showed that the MVA boost made the adenoviral-primed T cells markedly more polyfunctional, with the number of gamma interferon (INF-γ), tumor necrosis factor alpha (TNF-α), and interleukin-2 (IL-2) triple-positive and INF-γ and TNF-α double-positive cells increasing over time, while INF-γ single-positive cells declined with time. However, IFN-γ production prevailed as the main immune correlate of protection, while neither an increase of polyfunctionality nor a high integrated mean fluorescence intensity (iMFI) correlated with protection. These data highlight the ability of optimized viral vector prime-boost regimens to generate more protective and sustained CD8
+
T-cell responses, and our results encourage a more nuanced assessment of the importance of inducing polyfunctional CD8
+
T cells by vaccination.
Characterization of Virulence Plasmid Diversity among
Clostridium perfringens
Type B Isolates
Authors: Sayeed Sameera , Li Jihong , McClane Bruce A. 
Published: October 2009

ABSTRACT

The important veterinary pathogen
Clostridium perfringens
type B is unique for producing the two most lethal
C
.
perfringens
toxins, i.e., epsilon-toxin and beta-toxin. Our recent study (K. Miyamoto, J. Li, S. Sayeed, S. Akimoto, and B. A. McClane, J. Bacteriol. 190:7178-7188, 2008) showed that most, if not all, type B isolates carry a 65-kb epsilon-toxin-encoding plasmid. However, this epsilon-toxin plasmid did not possess the
cpb
gene encoding beta-toxin, suggesting that type B isolates carry at least one additional virulence plasmid. Therefore, the current study used Southern blotting of pulsed-field gels to localize the
cpb
gene to ∼90-kb plasmids in most type B isolates, although a few isolates carried a ∼65-kb
cpb
plasmid distinct from their
etx
plasmid. Overlapping PCR analysis then showed that the gene encoding the recently discovered TpeL toxin is located ∼3 kb downstream of the plasmid-borne
cpb
gene. As shown earlier for their epsilon-toxin-encoding plasmids, the beta-toxin-encoding plasmids of type B isolates were found to carry a
tcp
locus, suggesting that they are conjugative. Additionally, IS
1151
-like sequences were identified upstream of the
cpb
gene in type B isolates. These IS
1151
-like sequences may mobilize the
cpb
gene based upon detection of possible
cpb-
containing circular transposition intermediates. Most type B isolates also possessed a third virulence plasmid that carries genes encoding urease and lambda-toxin. Collectively, these findings suggest that type B isolates are among the most plasmid dependent of all
C. perfringens
isolates for virulence, as they usually carry three potential virulence plasmids.
Systematic Analysis of the SsrAB Virulon of
Salmonella enterica
Authors: Xu Xin , Hensel Michael 
Published: October 2009

ABSTRACT

Intracellular
Salmonella enterica
serovar Typhimurium deploys the
Salmonella
pathogenicity island 2 (SPI2)-encoded type III secretion system (T3SS) to modify host cell functions and accomplish intracellular replication. This virulence function is controlled by the two-component system SsrAB that regulates the expression of several operons in SPI2 and, in addition, a large number of genes for non-SPI2-encoded effector proteins. Here, we analyzed the relative expression levels of members of the SsrAB virulon. We used a novel reporter fusion strategy for single-copy chromosomal fusions, all done in an identical manner in order to enable direct quantitative comparison. We observed very high expression levels for
sseJ
and
sifA
; high expression levels for
ssaG
,
steC
,
sseL
, and
sopD2
; moderate expression levels for
ssaB
,
sseA
,
sseG
,
sifB
,
pipB2
, and
sspH1
; and low expression levels for
sspH2
,
sseI
,
slrP
,
sseK1
,
sseK2
,
pipB
, and
gogB
. The expression of the SsrAB virulon was highly dependent on the function of SsrB but also required EnvR/OmpZ. Deletion of PhoP, part of the global regulatory system PhoPQ, resulted in highly delayed expression of the SsrAB virulon under in vitro conditions; however, maximal expression was similar to that in a wild-type background. The expression levels of SsrAB-dependent genes in intracellular bacteria were in good agreement with in vitro analyses. We provide here a comprehensive and fully comparable analysis of the expression of genes in the SsrAB virulon. This information will be of interest for the selection of in vivo-activated promoters, for example, for rational design of recombinant vaccines.
Acid Phosphatases Do Not Contribute to the Pathogenesis of Type A
Francisella tularensis
Authors: Child Robert , Wehrly Tara D. , Rockx-Brouwer Dedeke , Dorward David W. , Celli Jean 
Published: October 2009

ABSTRACT

The intracellular pathogen
Francisella tularensis
is the causative agent of tularemia, a zoonosis that can affect humans with potentially lethal consequences. Essential to
Francisella
virulence is its ability to survive and proliferate within phagocytes through phagosomal escape and cytosolic replication.
Francisella
spp. encode a variety of acid phosphatases, whose roles in phagosomal escape and virulence have been documented yet remain controversial. Here we have examined in the highly virulent (type A)
F
.
tularensis
strain Schu S4 the pathogenic roles of three distinct acid phosphatases, AcpA, AcpB, and AcpC, that are most conserved between
Francisella
subspecies. Neither the deletion of
acpA
nor the combination of
acpA
,
acpB
, and
acpC
deletions affected the phagosomal escape or cytosolic growth of Schu S4 in murine and human macrophages, despite decreases in acid phosphatase activities by as much as 95%. Furthermore, none of these mutants were affected in their ability to cause lethality in mice upon intranasal inoculation. Hence, the acid phosphatases AcpA, AcpB, and AcpC do not contribute to intracellular pathogenesis and do not play a major role in the virulence of type A
Francisella
strains.
Impairment of Gamma Interferon Signaling in Human Neutrophils Infected withAnaplasma phagocytophilum
Authors: Bussmeyer Uta , Sarkar Arup , Broszat Kirsten , Lüdemann Tanja , Möller Sonja , van Zandbergen Ger , Bogdan Christian , Behnen Martina , Dumler J. Stephen , von Loewenich Friederike D. , Solbach Werner , Laskay Tamás 
Published: October 2009

ABSTRACTAnaplasma phagocytophilum, the causative agent of tick-borne human granulocytic anaplasmosis (HGA), is an intracellular bacterium which survives and multiplies inside polymorphonuclear neutrophil granulocytes (PMN). Increased bacterial burden in gamma interferon (IFN-γ)-deficient mice suggested a major role of IFN-γ in the control ofA. phagocytophilum. Here we investigated whether infection of human PMN withA. phagocytophilumimpairs IFN-γ signaling thus facilitating intracellular survival of the bacterium. The secretion of the IFN-γ-inducible chemokines IP-10/CXCL10 and MIG/CXCL9 was markedly inhibited in infected neutrophils. Molecular analyses revealed that, compared to uninfected PMN,A. phagocytophilumdecreased the expression of the IFN-γ receptor α-chain CD119, diminished the IFN-γ-induced phosphorylation of STAT1, and enhanced the expression of SOCS1 and SOCS3 in PMN. Since IFN-γ activates various antibacterial effector mechanisms of PMN, the impaired IFN-γ signaling in infected cells likely contributes to the survival ofA. phagocytophiluminside PMN and to HGA disease development.
Characterization of a ConditionalbosRMutant inBorrelia burgdorferi
Authors: Hyde Jenny A. , Shaw Dana K. , Smith Roger , Trzeciakowski Jerome P. , Skare Jon T. 
Published: October 2009

ABSTRACTBorrelia burgdorferi, the etiological agent of Lyme disease, adapts to unique host environments as a consequence of its complex life cycle that spans both arthropod and mammalian species. In this regard,B. burgdorferimust adapt to various environmental signals, pHs, temperatures, and O2and CO2levels to establish infectious foci. We hypothesize that the BosR protein functions as a global regulator that is required for both borrelial oxidative homeostasis and pathogenesis. To assess the role of BosR inB. burgdorferi, we constructed an IPTG (isopropyl-β-d-thiogalactopyranoside)-regulatedbosRstrain. The selective decrease ofbosRresulted in a change in growth when cells were cultured either anaerobically or microaerobically; however, a distinct growth defect was observed for anaerobically grownB. burgdorferirelative to the growth attenuation observed for microaerobically grownB. burgdorferi.B. burgdorfericells in which BosR levels were reduced were more sensitive to hydrogen peroxide and produced lower levels of NapA (Dps) and SodA, proteins involved in the oxidative stress response. In addition, the levels of OspC and DbpA were also induced coincident with increased BosR levels, suggesting that BosR interfaces with the RpoS regulatory cascade, which is known to modulate virulence gene expression inB. burgdorferi. Taken together, these results indicate that BosR is involved in the resistance ofB. burgdorferito oxidative stressors and affects the expression of genes, either directly or indirectly, whose products are important in borrelial pathogenesis.
An Orally Applicable Shiga Toxin Neutralizer Functions in the Intestine To Inhibit the Intracellular Transport of the Toxin
Authors: Watanabe-Takahashi Miho , Sato Toshio , Dohi Taeko , Noguchi Noriko , Kano Fumi , Murata Masayuki , Hamabata Takashi , Natori Yasuhiro , Nishikawa Kiyotaka 
Published: October 2009

ABSTRACT

Shiga toxin 2 (Stx2) is a major virulence factor in infections with Stx-producing
Escherichia coli
(STEC), which causes gastrointestinal diseases and sometimes fatal systemic complications. Recently, we developed an oral Stx2 inhibitor known as Ac-PPP-tet that exhibits remarkable therapeutic potency in an STEC infection model. However, the precise mechanism underlying the in vivo therapeutic effects of Ac-PPP-tet is unknown. Here, we found that Ac-PPP-tet completely inhibited fluid accumulation in the rabbit ileum caused by the direct injection of Stx2. Interestingly, Ac-PPP-tet accumulated in the ileal epithelial cells only through its formation of a complex with Stx2. The formation of Ac-PPP-tet-Stx2 complexes in cultured epithelial cells blocked the intracellular transport of Stx2 from the Golgi apparatus to the endoplasmic reticulum, a process that is essential for Stx2 cytotoxicity. Thus, Ac-PPP-tet is the first Stx neutralizer that functions in the intestine by altering the intracellular transport of Stx2 in epithelial cells.
Sex differences in force attenuation: a clinical assessment of single-leg hop performance on a portable force plate
Authors: Harrison A D , Ford K R , Myer G D , Hewett T E 
Published: October 2009

ObjectiveImpaired biomechanics and neuromuscular control have been suggested as probable links to female sex bias in the onset of patellofemoral pain syndrome. There are limited objective, clinical measures for assessment of impaired biomechanics and neuromuscular control. The primary objective of this investigation was to examine sex differences in vertical ground reaction force (vGRF) and force loading rate in young athletes performing maximum, repeated vertical single-leg hops (RVSHs). The authors hypothesised that females would demonstrate greater vGRF and force loading rate than males and show interlimb differences in force attenuation.DesignCross-sectional study.SettingPaediatric sports medicine clinic.Participants109 Healthy high school, soccer and basketball athletes.Assessment of risk factorsParticipants performed RVSHs for 15 seconds on a portable force plate with a sampling rate of 400 Hz (Accupower; AMTI, Watertown, Massachusetts, USA).Main outcome measurementsRaw vGRF was filtered with a generalised cross-validation spline using a 50-Hz cutoff frequency and then normalised to potential energy. Force loading rate was calculated by dividing normalised vGRF by time-to-peak force. Group means were compared using analysis of variance.ResultsThe females demonstrated significantly greater normalised vGRF (p<0.001) and force loading rate (p<0.001) during landing than their male counterparts. Neither sex demonstrated significant interlimb differences in force attenuation (p>0.05).ConclusionsThe female athletes may have altered force attenuation capability during RVSHs as identified by increased vGRF and force loading rate compared with the male athletes. Portable force plates may be potential tools to identify altered force attenuation in clinical settings.
Titrimetric immunohistochemical evaluation of DNA hypomethylation in uterine tumours
Authors: Wolk M , Martin J E 
Published: October 2009

Background:Global DNA hypomethylation is a well established feature of many common cancers.Aims:To establish a simple semi-quantitative, titrimetric immunohistochemical method in order to exploit this trait for prognostic purposes, in uterine cancers.Methods:A monoclonal antibody against 5-methylcytidine was used for immunohistochemical staining of methylated DNA in tumour cells. The degree of methylated DNA in the tumour tissue was visually compared and matched to that of normal tissues stained by serial decreasing concentrations of antibody to 5-methylcytidine.Results:Using this method a significant correlation was found between the histological stage and the reduction in DNA methylation in uterine adenocarcinoma (n = 39) and uterine squamous cell carcinoma (n = 23).Conclusions:A simple titrimetric immunohistochemical method has been developed for quantitative evaluation of ligands. This method should be further employed in follow-up studies, in order to establish the prognostic value of DNA hypomethylation in uterine cancer.
The clinicopathological significance of BUBR1 overexpression in hepatocellular carcinoma
Authors: Liu A-W , Cai J , Zhao X-L , Xu A-M , Fu H-q , Nian H , Zhang S-H 
Published: October 2009

Background and aims:BUBR1is a key component of the mitotic spindle checkpoint, and its roles in human cancers are controversial and unclear. The aim of this study was to investigate the clinicopathological significance of BUBR1 expression in hepatocellular carcinoma (HCC).Methods:The BUBR1 protein and its mRNA levels were measured in 58 HCCs, nine high-grade dysplastic nodules and their paired non-tumorous liver tissues by quantitative real-time polymerase chain reaction (qPCR) and western blot, respectively. In addition, immunochemical analysis of the BUBR1 protein was performed in 458 HCCs and 46 dysplastic nodules, and the clinicopathological significance of the BUBR1 expression was evaluated.Results:The BUBR1 expression at both mRNA and protein levels was elevated in two of nine high-grade dysplastic nodules and in 37 of 58 (64%) HCCs. BUBR1 was overexpressed in 207 of 458 (45%) HCCs by immunohistochemistry. Intriguingly, high expression of the BUBR1 was correlated with larger tumour size, higher histological grade, advanced pathological stage, and poor overall and recurrence-free survival. There was a higher frequency of BUBR1 overexpression in cases with positive serum HBsAg than those with negative HBsAg. Moreover, BUBR1 overexpression was associated with P53 staining and high Ki67 labelling indices in HCC tissues.Conclusions:BUBR1was overexpressed in about 45% HCCs, and its overexpression may be a relative lately event in HCC progression. Overexpression of BUBR1 was associated with worse prognosis and is a potential prognostic factor for patients with HCC.
Signature sequence validation of human papillomavirus type 16 (HPV-16) in clinical specimens
Authors: Lee Sin Hang , Vigliotti Veronica S , Pappu Suri 
Published: October 2009

AimsPersistent infection indicated by detection of human papillomavirus 16 (HPV-16) on repeat testing over a period of time poses the greatest cervical cancer risk. However, variants of HPV-16, HPV-31 and HPV-33 may share several short sequence homologies in the hypervariable L1 gene commonly targeted for HPV genotyping. The purpose of this study was to introduce a robust laboratory procedure to validate HPV-16 detected in clinical specimens, using the GenBank sequence database as the standard reference for genotyping.MethodsA nested PCR with two pairs of consensus primers was used to amplify the HPV DNA released in crude proteinase K digest of the cervicovaginal cells in liquid-based Papanicolaou cytology specimens. The positive nested PCR products were used for direct automated DNA sequencing.ResultsA 48-base sequence downstream of the GP5+ priming site, or a 34-base sequence upstream thereof, was needed for unequivocal validation of an HPV-16 isolate. Selection of a 45-base, or shorter, sequence immediately downstream of the GP5+ site for Basic Local Alignment Search Tool sequence analysis invariably led to ambiguous genotyping results.ConclusionsDNA sequence analysis may be used for differential genotyping of HPV-16, HPV-31 and HPV-33 in clinical specimens. However, selection of the signature sequence for Basic Local Alignment Search Tool algorithms is crucial to distinguish certain HPV-16 variants from other closely related HPV genotypes.