bluuebunny/crossref_metadata_2025_split huggingface dataset:
Identification and characterization of a fibronectin‐binding protein from Granulicatella adiacens
Authors: Yamaguchi T. , Soutome S. , Oho T. 
Published: August 2011

SummaryThe interaction of microorganisms with fibronectin plays an important role in infective endocarditis. Granulicatella adiacens is a member of the oral microbiota, formerly known as nutritionally variant streptococci, and is often isolated from endocarditis patients. In the present study we identified a surface protein, designated Cha, which binds to fibronectin, by a plaque hybridization procedure using the cshA sequence as probe, which encodes a fibronectin‐binding molecule of Streptococcus gordonii DL1. The cha sequence was highly homologous to cshA and encoded a product of 2351 amino acid residues. The protein comprised a unique sequence in the N‐terminal half region. The C‐terminal region contained nine complete, and one incomplete, 115‐amino acid residue repeat blocks. Among eight strains of nutritionally variant streptococci, three G. adiacens strains and one Abiotrophia defectiva strain carried the cha gene. Heterologous expression studies suggested that Cha adhered to immobilized fibronectin, and that this function was located in the unique region. Recombinant Cha protein also adhered to immobilize fibronectin and partially inhibited adherence of G. adiacens to fibronectin in a dose‐dependent manner. These results suggest that Cha is a cell surface protein that mediates adherence of G. adiacens to fibronectin.
An investigation of the chick chorioallantoic membrane as an alternative model to various biological tissues for permeation studies
Authors: Tay Stephanie Li Mei , Heng Paul Wan Sia , Chan Lai Wah 
Published: August 2011

Abstract

Objectives
The chick chorioallantoic membrane (CAM) was explored as a biological membrane for use in the study of drug permeation with a Franz diffusion cell.

Methods
The CAM was removed from fertilized chicken eggs of embryo age 9–18 days. The permeation profiles of nicotine through the fresh CAM were first obtained with a Franz diffusion cell. The permeation profiles of nicotine through frozen CAM, snake skin, pig skin, pig retina and pig buccal mucosa were also determined and compared with those of the fresh CAM.

Key findings
The permeability coefficient of the CAM varied with its age. The CAM at embryo age 13 was the most robust, showing the lowest standard error in permeability. It was thus chosen for comparative studies with snake skin, pig skin, retina and buccal mucosa. The CAM was found to be most similar to the buccal mucosa in terms of permeation profile and permeability coefficient values. Frozen CAM was also found to have a higher permeability coefficient than fresh CAM. The enhanced permeability was attributed to freezing, which affected the integrity of the CAM structure.

Conclusions
From the findings, CAM shows potential as an alternative to the pig buccal mucosa as an in-vitro buccal model. The robustness of the CAM for drug permeation studies is affected by its age.
Novel gel formulations with catanionic aggregates enable prolonged drug release and reduced skin permeation
Authors: Dew Noel , Edsman Katarina , Björk Erik 
Published: August 2011

Abstract

Objectives
The aim of this study was to investigate skin permeation rates of a drug substance when applied in novel gel formulations with catanionic aggregates.

Methods
Reference gel without catanionic aggregates was compared with formulations with catanionic aggregates composed of tetracaine and either sodium dodecyl sulphate (SDS) or capric acid. Carbomer and SoftCAT were used to compare the effect of different gel types to elucidate if physically cross-linked, ‘self-destructing’ systems had benefits compared with classical, covalently cross-linked, gels.

Key findings
The rheological investigation showed that the interactions between the SoftCAT polymer and tetracaine/SDS aggregates were stronger than when the tetracaine/capric acid aggregates were used. The skin permeation was measured ex vivo in horizontal Ussing chambers and the permeation of tetracaine was significantly lower when formulations with tetracaine/SDS aggregates were applied (P &lt; 0.001), but not statistically different from the reference when capric acid was used.

Conclusions
No morphological differences could be distinguished between the skin samples exposed to the different formulations or the reference. Skin permeation was compared with silicone sheet permeation and the results indicated that silicone sheets could be used as a model of skin when using these formulations.
Wide Dissemination of Pseudomonas aeruginosa Producing β-Lactamase
bla
KPC-2
Gene in Colombia
Authors: Cuzon Gaelle , Naas Thierry , Villegas Maria-Virginia , Correa Adriana , Quinn John P. , Nordmann Patrice 
Published: August 2011

ABSTRACT

Ten
bla
KPC-2
-harboring
Pseudomonas aeruginosa
isolates from hospitals located in five different Colombian cities have been characterized. Isolates were multidrug resistant, belonged to five different pulsotypes, and possessed naturally chromosome-encoded
bla
AmpC
and
bla
OXA-50
genes and the acquired
bla
KPC-2
gene. In most cases, the
bla
KPC-2
genes were carried by plasmids of different sizes and were associated with Tn
4401b
or a new structure containing only part of the Tn
4401
sequence. This study revealed that several clones of
P. aeruginosa
producing
bla
KPC-2
are disseminating in Colombia.
Discovery of a Novel Class of Orally Active Antifungal β-1,3-
d
-Glucan Synthase Inhibitors
Authors: Walker Scott S. , Xu Yiming , Triantafyllou Ilias , Waldman Michelle F. , Mendrick Cara , Brown Nathaniel , Mann Paul , Chau Andrew , Patel Reena , Bauman Nicholas , Norris Christine , Antonacci Barry , Gurnani Maya , Cacciapuoti Anthony , McNicholas Paul M. , Wainhaus Samuel , Herr R. Jason , Kuang Rongze , Aslanian Robert G. , Ting Pauline C. , Black Todd A. 
Published: August 2011

ABSTRACT

The echinocandins are a class of semisynthetic natural products that target β-1,3-glucan synthase (GS). Their proven clinical efficacy combined with minimal safety issues has made the echinocandins an important asset in the management of fungal infection in a variety of patient populations. However, the echinocandins are delivered only parenterally. A screen for antifungal bioactivities combined with mechanism-of-action studies identified a class of piperazinyl-pyridazinones that target GS. The compounds exhibited
in vitro
activity comparable, and in some cases superior, to that of the echinocandins. The compounds inhibit GS
in vitro
, and there was a strong correlation between enzyme inhibition and
in vitro
antifungal activity. In addition, like the echinocandins, the compounds caused a leakage of cytoplasmic contents from yeast and produced a morphological response in molds characteristic of GS inhibitors. Spontaneous mutants of
Saccharomyces cerevisiae
with reduced susceptibility to the piperazinyl-pyridazinones had substitutions in
FKS1
. The sites of these substitutions were distinct from those conferring resistance to echinocandins; likewise, echinocandin-resistant isolates remained susceptible to the test compounds. Finally, we present efficacy and pharmacokinetic data on an example of the piperazinyl-pyridazinone compounds that demonstrated efficacy in a murine model of
Candida glabrata
infection.
In Vitro
Activity of a Novel Broad-Spectrum Antifungal, E1210, Tested against Aspergillus spp. Determined by CLSI and EUCAST Broth Microdilution Methods
Authors: Pfaller Michael A. , Duncanson Frederick , Messer Shawn A. , Moet Gary J. , Jones Ronald N. , Castanheira Mariana 
Published: August 2011

ABSTRACT

E1210 is a first-in-class broad-spectrum antifungal that suppresses hyphal growth by inhibiting fungal glycophosphatidylinositol (GPI) biosynthesis. In the present study, we extend these findings by examining the activity of E1210 and comparator antifungal agents against
Aspergillus
spp. by using the methods of the Clinical and Laboratory Standards Institute (CLSI) and the European Committee for Antimicrobial Susceptibility Testing (EUCAST) to test wild-type (WT) as well as amphotericin B (AMB)-resistant (-R) and azole-R strains (as determined by CLSI methods). Seventy-eight clinical isolates of
Aspergillus
were tested including 20 isolates of
Aspergillus flavus
species complex (SC), 22 of
A. fumigatus
SC, 13 of
A. niger
SC, and 23 of
A. terreus
SC. The collection included 15 AMB-R (MIC, ≥2 μg/ml) isolates of
A. terreus
SC and 10 itraconazole-R (MIC, ≥4 μg/ml) isolates of
A. fumigatus
SC (7 isolates),
A. niger
SC (2 isolates), and
A. terreus
SC (1 isolate). Comparator antifungal agents included anidulafungin, caspofungin, amphotericin B, itraconazole, posaconzole, and voriconazole. Both CLSI and EUCAST methods were highly concordant for E1210 and all comparators. The essential agreement (EA; ±2 log
2
dilution steps) was 100% for all comparisons with the exception of posaconazole versus
A. terreus
SC (EA = 91.3%). The minimum effective concentration (MEC)/MIC
90
values (μg/ml) for E1210, anidulafungin, caspofungin, itraconazole, posaconazole, and voriconazole, respectively, were as follows for each species: for
A. flavus
SC, 0.03, ≤0.008, 0.12, 1, 1, and 1; for
A. fumigatus
SC, 0.06, 0.015, 0.12, >8, 1, and 4; for
A. niger
SC, 0.015, 0.03, 0.12, 4, 1, and 2; and for
A. terreus
SC, 0.06, 0.015, 0.12, 1, 0.5, and 1. E1210 was very active against AMB-R strains of
A. terreus
SC (MEC range, 0.015 to 0.06 μg/ml) and itraconazole-R strains of
A. fumigatus
SC (MEC range, 0.03 to 0.12 μg/ml),
A. niger
SC (MEC, 0.008 μg/ml), and
A. terreus
SC (MEC, 0.015 μg/ml). In conclusion, E1210 was a very potent and broad-spectrum antifungal agent regardless of
in vitro
method applied, with excellent activity against AMB-R and itraconazole-R strains of
Aspergillus
spp.
Comparative Susceptibilities to Fidaxomicin (OPT-80) of Isolates Collected at Baseline, Recurrence, and Failure from Patients in Two Phase III Trials of Fidaxomicin against Clostridium difficile Infection
Authors: Goldstein Ellie J. C. , Citron Diane M. , Sears Pamela , Babakhani Farah , Sambol Susan P. , Gerding Dale N. 
Published: August 2011

ABSTRACT

A 10-day course of oral fidaxomicin (200 mg twice a day [b.i.d.]), a potent new macrocyclic drug, was compared to vancomycin (125 mg four times a day [q.i.d.]) in 1,164 adults (1,105 in the modified intent-to-treat [mITT] population) with
Clostridium difficile
infection in two phase III randomized, double-blind trials at sites in North America and 7 European countries. Of 1,105 mITT patients, 792 (71.7%), including 719/999 (72.0%) in the per-protocol (PP) population, provided a
C. difficile
strain at baseline, of whom 356 received fidaxomicin with 330 cures (92.7%) and 363 received vancomycin with 329 cures (90.6%). The susceptibilities (MIC
90
) of baseline isolates did not predict clinical cure, failure, or recurrence for fidaxomicin (MIC
90
, 0.25 μg/ml for both; range, ≤0.007 to 1 μg/ml), but there was a one-dilution difference in the MIC
90
(but not the MIC
50
) for vancomycin (MIC
90
, 2 μg/ml [range, 0.25 to 8 μg/ml] for cure and 4.0 μg/ml [range, 0.5 to 4 μg/ml] for failures). A total of 65 (7.9%) “rifaximin-resistant” (MIC > 256 μg/ml) strains were isolated in both treatment groups on enrollment, which increased to 25% for failures at the end of therapy. No resistance to either fidaxomicin or vancomycin developed during treatment in either of the phase III studies, although a single strain isolated from a cured patient had an elevated fidaxomicin MIC of 16 μg/ml at the time of recurrence. All isolates were susceptible to ≤4 μg/ml of metronidazole. When analyzed by restriction endonuclease analysis (REA) type, 247/719 (34.4%) isolates were BI group isolates, and the MICs were generally higher for all four drugs tested (MIC
90
s: fidaxomicin, 0.5; vancomycin, 2.0; metronidazole, 2.0; and rifaximin, >256 μg/ml) than for the other REA types. There was no correlation between the MIC of a baseline clinical isolate and clinical outcome. MIC
90
s were generally low for fidaxomicin and vancomycin, but BI isolates had higher MICs than other REA group isolates.
Citrobacter spp. as a Source of
qnrB
Alleles
Authors: Jacoby George A. , Griffin Caitlin M. , Hooper David C. 
Published: August 2011

ABSTRACT

qnrB
is the most common of the five
qnr
families and has the greatest number of allelic variants. Almost two-thirds of the
qnrB
alleles have been reported in
Citrobacter
spp., and several were shown to be located on the chromosome. In this study, PCR was used to investigate the prevalence of plasmid-mediated quinolone resistance genes in 71 clinical isolates belonging to the
Citrobacter freundii
complex. Thirty-seven percent contained
qnrB
alleles, including 7 (
qnrB32 to qnrB38
) that were novel and 1 pseudogene, while none contained
qnrA
,
qnrC
,
qnrD
,
qnrS
, or
aac(6′)-Ib-cr
. When the strains were arrayed by related 16S rRNA sequence and further separated into subspecies by biochemical criteria, clustering of
qnrB
-positive strains was evident. In only two strains with
qnrB2
and
qnrB4
was quinolone resistance transferable by conjugation, and only these strains contained the IS
CR1
sequence that is often associated with
qnrB
on plasmids. Five of 26
qnrB
-positive strains contained integrase genes, but these included the strains with
qnrB2
and
qnrB4
as well as two strains with other transmissible plasmids. In a fully sequenced genome of
Citrobacter youngae
, a member of the
C. freundii
complex, another novel
qnrB
allele,
qnrB39
, occurs in a sequence of genes that is 90% identical to sequence surrounding integron-associated
qnrB4
incorporated into plasmids. The chromosome of
Citrobacter
is the likely source of plasmid-mediated
qnrB
.
Type III Secretion System-Dependent Translocation of Ectopically Expressed Yop Effectors into Macrophages by Intracellular Yersinia pseudotuberculosis
Authors: Zhang Yue , Romanov Galina , Bliska James B. 
Published: August 2011

ABSTRACT

Yersinia pseudotuberculosis
is a Gram-negative bacterial pathogen. Virulence in
Y. pseudotuberculosis
requires the plasmid-encoded Ysc type III secretion system (T3SS), which functions to translocate a set of effectors called Yops into infected host cells. The effectors function to antagonize phagocytosis (e.g., YopH) or to induce apoptosis (YopJ) in macrophages infected with
Y. pseudotuberculosis
. Additionally, when antiphagocytosis is incomplete and
Y. pseudotuberculosis
is internalized by macrophages, the bacterium can survive in phagosomes. Previous studies have shown that delivery of effectors into host cells occurs efficiently when
Yersinia
is extracellular. However, it is not clear whether the T3SS can be utilized by intracellular
Y. pseudotuberculosis
to translocate Yops. This possibility was investigated here using
Y. pseudotuberculosis
strains that express YopJ or YopH under the control of an inducible promoter. Bone marrow-derived murine macrophages were infected with these strains under conditions that prevented the survival of extracellular bacteria. Effector translocation was detected by measuring apoptosis or the activities of Yop-β-lactamase fusion proteins. Results showed that macrophages underwent apoptosis when YopJ expression was induced prior to phagocytosis, confirming that delivery of this effector prior to or during uptake is sufficient to cause cell death. However, macrophages also underwent apoptosis when YopJ was ectopically expressed after phagocytosis; furthermore, expression of the translocator YopB from intracellular bacteria also resulted in increased cell death. Analysis by microscopy showed that translocation of ectopically expressed YopH- or YopJ-β-lactamase fusions could be correlated with the presence of viable
Y. pseudotuberculosis
in macrophages. Collectively, our results suggest that the Ysc T3SS of
Y. pseudotuberculosis
can function within macrophage phagosomes to translocate Yops into the host cytosol.
Structural and Functional Interactions between the Cholera Toxin A1 Subunit and ERdj3/HEDJ, a Chaperone of the Endoplasmic Reticulum
Authors: Massey Shane , Burress Helen , Taylor Michael , Nemec Kathleen N. , Ray Supriyo , Haslam David B. , Teter Ken 
Published: August 2011

ABSTRACT

Cholera toxin (CT) is endocytosed and transported by vesicle carriers to the endoplasmic reticulum (ER). The catalytic CTA1 subunit then crosses the ER membrane and enters the cytosol, where it interacts with its Gsα target. The CTA1 membrane transversal involves the ER chaperone BiP, but few other host proteins involved with CTA1 translocation are known. BiP function is regulated by ERdj3, an ER-localized Hsp40 chaperone also known as HEDJ. ERdj3 can also influence protein folding and translocation by direct substrate binding. In this work, structural and functional assays were used to examine the putative interaction between ERdj3 and CTA1. Cell-based assays demonstrated that expression of a dominant negative ERdj3 blocks CTA1 translocation into the cytosol and CT intoxication. Binding assays with surface plasmon resonance demonstrated that monomeric ERdj3 interacts directly with CTA1. This interaction involved the A1
2
subdomain of CTA1 and was further dependent upon the overall structure of CTA1: ERdj3 bound to unfolded but not folded conformations of the isolated CTA1 subunit. This was consistent with the chaperone function of ERdj3, as was the ability of ERdj3 to mask the solvent-exposed hydrophobic residues of CTA1. Our data identify ERdj3 as a host protein involved with the CT intoxication process and provide new molecular details regarding CTA1-chaperone interactions.
Two methods for assessing oral reading prosody
Authors: Duong Minh , Mostow Jack , Sitaram Sunayana 
Published: August 2011

We compare two types of models to assess the prosody of children's oral reading. Template models measure how well the child's prosodic contour in reading a given sentence correlates in pitch, intensity, pauses, or word reading times with an adult narration of the same sentence. We evaluate template models directly against a common rubric used to assess fluency by hand, and indirectly by their ability to predict fluency and comprehension test scores and gains of 10 children who used Project LISTEN's Reading Tutor; the template models outpredict the human assessment.
We also use the same set of adult narrations to train generalized models for mapping text to prosody, and use them to evaluate children's prosody. Using only durational features for both types of models, the generalized models perform better at predicting fluency and comprehension posttest scores of 55 children ages 7--10, with adjusted R2 of 0.6. Such models could help teachers identify which students are making adequate progress. The generalized models have the additional advantage of not requiring an adult narration of every sentence.
Cyclin D1 and Cdk4 Mediate Development of Neurologically Destructive Oligodendroglioma
Authors: Ciznadija Daniel , Liu Yuhui , Pyonteck Stephanie M. , Holland Eric C. , Koff Andrew 
Published: August 2011

Abstract
Although the molecular changes that characterize gliomas have been studied, the pathogenesis of tumor development remains unclear. p21 contributes to gliomagenesis by stabilizing cyclin D1–cdk4 kinase complexes, suggesting that cyclin D1 and cdk4 may also be required for glial tumor development. In this study, we used a mouse model to attempt to confirm this hypothesis, finding that cyclin D1 and cdk4 played active roles in not only the tumor but also the tumor microenvironment. Loss of cdk4 blocked tumor development, but loss of cyclin D1 did not prevent gliomas from developing. Instead, loss of cyclin D1 impeded progression to higher stages of malignancy. Enforcing expression of cyclin D1 was insufficient to correct the progression defect observed in cyclin D1–deficient animals. In contrast, restoration of cdk4 in the cdk4-deficient animals restored cell proliferation and tumor formation, although at lower tumor grades. Notably, the failure of tumors in the cyclin D1- and cdk4-deficient animals to progress to higher grades was correlated with a failure to fully activate microglia in the tumor microenvironment. Moreover, when platelet-derived growth factor–transformed glial cells were engrafted orthotopically into the mice, the tumors that formed progressed to high grades in wild-type mice but not cyclin D1–deficient animals. Together, our findings establish that the cyclin D1–cdk4 axis is not only critical in glial tumor cells but also in stromal-derived cells in the surrounding tumor microenvironment that are vital to sustain tumor outgrowth. Cancer Res; 71(19); 6174–83. ©2011 AACR.
Donor Simvastatin Treatment Abolishes Rat Cardiac Allograft Ischemia/Reperfusion Injury and Chronic Rejection Through Microvascular Protection
Authors: Tuuminen Raimo , Syrjälä Simo , Krebs Rainer , Keränen Mikko A.I. , Koli Katri , Abo-Ramadan Usama , Neuvonen Pertti J. , Tikkanen Jussi M. , Nykänen Antti I. , Lemström Karl B. 
Published: August 2011

Background—
Ischemia/reperfusion injury may have deleterious short- and long-term consequences for cardiac allografts. The underlying mechanisms involve microvascular dysfunction that may culminate in primary graft failure or untreatable chronic rejection.

Methods and Results—

Here, we report that rat cardiac allograft ischemia/reperfusion injury resulted in profound microvascular dysfunction that was prevented by donor treatment with peroral single-dose simvastatin, a 3-hydroxy-3-methylglutaryl coenzyme A reductase and Rho GTPase inhibitor, 2 hours before graft procurement. During allograft preservation, donor simvastatin treatment inhibited microvascular endothelial cell and pericyte RhoA/Rho-associated protein kinase activation and endothelial cell–endothelial cell gap formation; decreased intragraft mRNA levels of hypoxia-inducible factor-1α, inducible nitric oxide synthase, and endothelin-1; and increased heme oxygenase-1. Donor, but not recipient, simvastatin treatment prevented ischemia/reperfusion injury–induced vascular leakage, leukocyte infiltration, the no-reflow phenomenon, and myocardial injury. The beneficial effects of simvastatin on vascular stability and the no-reflow phenomenon were abolished by concomitant nitric oxide synthase inhibition with
N
-nitro-
l
-arginine methyl ester and RhoA activation by geranylgeranyl pyrophosphate supplementation, respectively. In the chronic rejection model, donor simvastatin treatment inhibited cardiac allograft inflammation, transforming growth factor-β1 signaling, and myocardial fibrosis. In vitro, simvastatin inhibited transforming growth factor-β1–induced microvascular endothelial-to-mesenchymal transition.

Conclusions—
Our results demonstrate that donor simvastatin treatment prevents microvascular endothelial cell and pericyte dysfunction, ischemia/reperfusion injury, and chronic rejection and suggest a novel, clinically feasible strategy to protect cardiac allografts.