bluuebunny/crossref_metadata_2025_split huggingface dataset:
Molecular Characterization of Multidrug-Resistant Escherichia coli Isolates from Irish Cattle Farms
Authors: Karczmarczyk Maria , Walsh Ciara , Slowey Rosemarie , Leonard Nola , Fanning Séamus 
Published: August 2011

ABSTRACT

This study describes the genotypic characteristics of a collection of 100 multidrug-resistant (MDR)
Escherichia coli
strains recovered from cattle and the farm environment in Ireland in 2007. The most prevalent antimicrobial resistance identified was to streptomycin (100%), followed by tetracycline (99%), sulfonamides (98%), ampicillin (82%), and neomycin (62%). Resistance was mediated predominantly by
strA-strB
(92%),
tetA
(67%),
sul2
(90%),
bla
TEM
(79%), and
aphA1
(63%) gene markers, respectively. Twenty-seven isolates harbored a class 1 integrase (
intI1
), while
qacE
Δ
1
and
sul1
markers were identified in 25 and 26 isolates, respectively. The variable regions of these integrons contained aminoglycoside, trimethoprim, and β-lactam resistance determinants (
aadA12
,
aadB
-
aadA1
,
bla
OXA-30
-
aadA1
,
dfrA1
-
aadA1
,
dfrA7
). Class 2 integrons were identified less frequently (4%) and contained the gene cassette array
dfrA1-sat1-aadA1
. Resistance to ampicillin, neomycin, streptomycin, sulfonamide, and tetracycline was associated with transferable high-molecular-weight plasmids, as demonstrated by conjugation assays. A panel of virulence markers was screened for by PCR, and genes identified included
vt1
, K5 in 2 isolates,
papC
in 10 isolates, and PAI IV
536
in 37 isolates. MDR commensal
E. coli
isolates from Irish cattle displayed considerable diversity with respect to the genes identified. Our findings highlight the importance of the commensal microflora of food-producing animals as a reservoir of transferable MDR.
Comparative Genomic Analysis of Acinetobacter oleivorans DR1 To Determine Strain-Specific Genomic Regions and Gentisate Biodegradation
Authors: Jung Jaejoon , Madsen Eugene L. , Jeon Che Ok , Park Woojun 
Published: August 2011

ABSTRACT

The comparative genomics of
Acinetobacter oleivorans
DR1 assayed with
A. baylyi
ADP1,
A. calcoaceticus
PHEA-2, and
A. baumannii
ATCC 17978 revealed that the incorporation of phage-related genomic regions and the absence of transposable elements have contributed to the large size (4.15 Mb) of the DR1 genome. A horizontally transferred genomic region and a higher proportion of transcriptional regulator- and signal peptide-coding genes were identified as characteristics of the DR1 genome. Incomplete glucose metabolism, metabolic pathways of aromatic compounds, biofilm formation, antibiotics and metal resistance, and natural competence genes were conserved in four compared genomes. Interestingly, only strain DR1 possesses gentisate 1,2-dioxygenase (
nagI
) and grows on gentisate, whereas other species cannot. Expression of the
nagI
gene was upregulated during gentisate utilization, and four downstream open reading frames (ORFs) were cotranscribed, supporting the notion that gentisate metabolism is a unique characteristic of strain DR1. The genomic analysis of strain DR1 provides additional insights into the function, ecology, and evolution of
Acinetobacter
species.
β-Lactams and Florfenicol Antibiotics Remain Bioactive in Soils while Ciprofloxacin, Neomycin, and Tetracycline Are Neutralized
Authors: Subbiah Murugan , Mitchell Shannon M. , Ullman Jeffrey L. , Call Douglas R. 
Published: August 2011

ABSTRACT

It is generally assumed that antibiotic residues in soils select for antibiotic-resistant bacteria. This assumption was tested by separately adding 10 different antibiotics (≥200 ppm) to three soil-water slurries (silt-loam, sand-loam, and sand; 20% soil [wt/vol]) and incubating mixtures for 24 h at room temperature. The antibiotic activity of the resultant supernatant was assessed by culturing a sensitive
Escherichia coli
strain in the filter-sterilized supernatant augmented with Luria-Bertani broth. We found striking differences in the abilities of supernatants to suppress growth of the indicator
E. coli
. Ampicillin, cephalothin, cefoxitin, ceftiofur, and florfenicol supernatants completely inhibited growth while bacterial growth was uninhibited in the presence of neomycin, tetracycline, and ciprofloxacin supernatants. High-performance liquid chromatography (HPLC) analysis demonstrated that cefoxitin and florfenicol were almost completely retained in the supernatants, whereas tetracycline and ciprofloxacin were mostly removed. Antibiotic dissipation in soil, presumably dominated by adsorption mechanisms, was sufficient to neutralize 200 ppm of tetracycline; this concentration is considerably higher than reported contamination levels. Soil pellets from the tetracycline slurries were resuspended in a minimal volume of medium to maximize the interaction between bacteria and soil particles, but sensitive bacteria were still unaffected by tetracycline (
P
= 0.6). Thus, residual antibiotics in soil do not necessarily exert a selective pressure, and the degree to which the pharmaceutical remains bioactive depends on the antibiotic. Efforts to control antibiotic contamination would be better directed toward compounds that retain biological activity in soils (e.g., cephalosporins and florfenicol) because these are the antibiotics that could exert a selective pressure in the environment.
Aedes aegypti Membrane-Bound Alkaline Phosphatase Expressed in Escherichia coli Retains High-Affinity Binding for Bacillus thuringiensis Cry4Ba Toxin
Authors: Thammasittirong Anon , Dechklar Manasave , Leetachewa Somphob , Pootanakit Kusol , Angsuthanasombat Chanan 
Published: August 2011

ABSTRACT

Glycosylphosphatidylinositol-linked alkaline phosphatase (GPI-ALP) from the epithelial membrane of the larval midgut of
Aedes aegypti
was previously identified as a functional receptor of the
Bacillus thuringiensis
Cry4Ba toxin. Here, heterologous expression in
Escherichia coli
of the cloned ALP, lacking the secretion signal and GPI attachment sequences, and assessment of its binding characteristics were further investigated. The 54-kDa His tag-fused ALP overexpressed as an inclusion body was soluble when phosphate buffer (pH 7.5) was supplemented with 8 M urea. After renaturation in a nickel-nitrilotriacetic acid (Ni-NTA) affinity column, the refolded ALP protein was able to retain its phosphatase activity. This refolded ALP also showed binding to the 65-kDa activated Cry4Ba toxin under nondenaturing (dot blot) conditions. Quantitative binding analysis using a quartz crystal microbalance revealed that the purified ALP immobilized on a gold electrode was bound by the Cry4Ba toxin in a stoichiometry of approximately 1:2 and with high affinity (dissociation constant [
K

d

] of ∼14 nM) which is comparable to that calculated from kinetic parameters (dissociation rate constant [
k
off
]/binding constant [
k
on
]). Altogether, the data presented here of the
E. coli
-expressed ALP from
A. aegypti
retaining high-affinity toxin binding support our notion that glycosylation of this receptor is not required for binding to its counterpart toxin, Cry4Ba.
Differential Regulation of Orthologous Chitinase Genes in Mycoparasitic Trichoderma Species
Authors: Gruber Sabine , Kubicek Christian P. , Seidl-Seiboth Verena 
Published: August 2011

ABSTRACT

Mycoparasitic
Trichoderma
species have expanded numbers of fungal subgroup C chitinases that contain multiple carbohydrate binding modules and could thus be important for fungal cell wall degradation during the mycoparasitic attack. In this study, we analyzed the gene regulation of subgroup C chitinases in the mycoparasite
Trichoderma virens
. In addition to regulation by nutritional stimuli, we found complex expression patterns in different parts of the fungal colony, and also, the mode of cultivation strongly influenced subgroup C chitinase transcript levels. Thus, the regulation of these genes is governed by a combination of colony-internal and -external signals. Our results showed completely different expression profiles of subgroup C chitinase genes in
T. virens
than in a previous study with
T. atroviride
, although both fungi are potent mycoparasites. Only a few subgroup C chitinase orthologues were found in
T. atroviride
and
T. virens
, and even those showed substantially divergent gene expression patterns. Microscopic analysis revealed morphogenetic differences between
T. atroviride
and
T. virens
, which could be connected to differential subgroup C chitinase gene expression. The biological function of fungal subgroup C chitinases therefore might not be as clear-cut as previously anticipated. They could have pleiotropic roles and might be involved in both degradation of exogenous chitinous carbon sources, including other fungal cell walls, and recycling of their own cell walls during hyphal development and colony formation.
Ncb2 Is Involved in Activated Transcription of
CDR1
in Azole-Resistant Clinical Isolates of Candida albicans
Authors: Shukla Shipra , Yadav Vipin , Mukhopadhyay Gauranga , Prasad Rajendra 
Published: August 2011

ABSTRACT

We recently demonstrated that
CDR1
overexpression in azole-resistant isolates of
Candida albicans
is due to its enhanced transcriptional activation and increased mRNA stability. In this study, we provide the first evidence of transcriptional regulation of
CDR1
by Ncb2, the β subunit of NC2, a heterodimeric regulator of transcription. Conditional
NCB2
null mutants displayed decreased susceptibility toward azole and an enhanced transcription of
CDR1
. Interestingly, Ncb2 associated with the
CDR1
promoter under both repression and activation; however, an increase in recruitment was observed under both transient and constitutive activation states. By chromatin immunoprecipitation (ChIP) assay, we showed the preferential recruitment of Ncb2 to the core TATA region under activation (azole-resistant isolate), while under repression (azole-susceptible isolate) it was present at the TATA upstream region. Further, ChIP analysis revealed that Ncb2 binding was not restricted to the
CDR1
gene; instead, it was observed on the promoters of genes coregulated with
CDR1
by the transcription activator Tac1. The
tac1
Δ null mutants, which fail to show the drug-induced transient activation of
CDR1
, also showed no increase in Ncb2 recruitment at the promoter. Taken together, our results show that Ncb2, in conjunction with Tac1, is involved in the transcriptional activation of
CDR1
, opening up new therapeutic possibilities to combat multidrug resistance (MDR) in
C. albicans
.
Cellular Effects and Epistasis among Three Determinants of Adaptation in Experimental Populations of Saccharomyces cerevisiae
Authors: Parreiras Lucas S. , Kohn Linda M. , Anderson James B. 
Published: August 2011

ABSTRACT

Epistatic interactions in which the phenotypic effect of an allele is conditional on its genetic background have been shown to play a central part in various evolutionary processes. In a previous study (J. B. Anderson et al., Curr. Biol. 20:1383-1388, 2010; J. R. Dettman, C. Sirjusingh, L. M. Kohn, and J. B. Anderson, Nature 447:585-588, 2007), beginning with a common ancestor, we identified three determinants of fitness as mutant alleles (each designated with the letter “
e
”) that arose in replicate
Saccharomyces cerevisiae
populations propagated in two different environments, a low-glucose and a high-salt environment. In a low-glucose environment,
MDS3e
and
MKT1e
interacted positively to confer a fitness advantage. Also,
PMA1e
from a high-salt environment interacted negatively with
MKT1e
in a low-glucose environment, an example of a Dobzhansky-Muller incompatibility that confers reproductive isolation. Here we showed that the negative interaction between
PMA1e
and
MKT1e
is mediated by alterations in intracellular pH, while the positive interaction between
MDS3e
and
MKT1e
is mediated by changes in gene expression affecting glucose transporter genes. We specifically addressed the evolutionary significance of the positive interaction by showing that the presence of the
MDS3
mutation is a necessary condition for the spread and fixation of the new mutations at the identical site in
MKT1
. The expected mutations in
MKT1
rose to high frequencies in two of three experimental populations carrying
MDS3e
but not in any of three populations carrying the ancestral allele. These data show how positive and negative epistasis can contribute to adaptation and reproductive isolation.
Ehrlichia chaffeensis TRP120 Interacts with a Diverse Array of Eukaryotic Proteins Involved in Transcription, Signaling, and Cytoskeleton Organization
Authors: Luo Tian , Kuriakose Jeeba A. , Zhu Bing , Wakeel Abdul , McBride Jere W. 
Published: August 2011

ABSTRACTEhrlichia chaffeensisis an obligately intracellular bacterium that exhibits tropism for mononuclear phagocytes and survives by evading host cell defense mechanisms. Recently, molecular interactions betweenE. chaffeensis47-kDa tandem repeat (TR) protein (TRP47) and the eukaryotic host cell have been described. In this investigation, yeast (Saccharomyces cerevisiae) two-hybrid analysis demonstrated thatE. chaffeensis-secreted tandem repeat protein 120 (TRP120) interacts with a diverse group of host cell proteins associated with major biological processes, including transcription and regulation, cell signaling, protein trafficking, and actin cytoskeleton organization. Twelve target proteins with the highest frequency of interaction with TRP120 were confirmed by cotransformation in yeast. Host targets, including human immunoglobulin lambda locus (IGL), cytochromecoxidase subunit II (COX2), Golgi-associated gamma adaptin ear-containing ARF binding protein 1 (GGA1), polycomb group ring finger 5 (PCGF5), actin gamma 1 (ACTG1), and unc-13 homolog D (UNC13D;Caenorhabditis elegans), colocalized strongly with TRP120 in HeLa cells and withE. chaffeensisdense-cored morulae and areas adjacent to morulae in the host cytoplasm. The TR domain of TRP120 interacted only with PCGF5, indicating that distinct TRP120 domains contribute to specific host target interactions and that multiple domains are required to reconstitute TRP120 interactions with other host targets. Three previously defined molecular interactions between TRP47 and host proteins, PCGF5, IGLL1, and CAP1, were also associated with TRP120, demonstrating that molecular cross talk occurs betweenEhrlichiaTRPs and host targets. These findings further support the role of TRPs as effectors that reprogram the host cell.
Atraumatic headache in US emergency departments: recent trends in CT/MRI utilisation and factors associated with severe intracranial pathology
Authors: Gilbert John W , Johnson Kevin M , Larkin Gregory L , Moore Christopher L 
Published: August 2011

ObjectivesTo estimate recent trends in CT/MRI utilisation among patients seeking emergency care for atraumatic headache in the USA and to identify factors associated with a diagnosis of significant intracranial pathology (ICP) in these patients.Design/setting/participantsData were obtained from the USA National Hospital Ambulatory Medical Care Survey of emergency department (ED) visits between 1998 and 2008. A cohort of atraumatic headache-related visits were identified using preassigned ‘reason-for-visit’ codes. Sample visits were weighted to provide national estimates.ResultsBetween 1998 and 2008 the percentage of patients presenting to the ED with atraumatic headache who underwent imaging increased from 12.5% to 31.0% (p<0.01) while the prevalence of ICP among those visits decreased from 10.1% to 3.5% (p<0.05). The length of stay in the ED was 4.6 h (95% CI 4.4 to 4.8) for patients with headache who received imaging compared with 2.7 (95% CI 2.6 to 2.9) for those who did not. Of 18 factors evaluated in patients with headache, 10 were associated with a significantly increased odds of an ICP diagnosis: age ≥50 years, arrival by ambulance, triage immediacy <15 min, systolic blood pressure ≥160 mm Hg or diastolic blood pressure ≥100 mm Hg and disturbance in sensation, vision, speech or motor function including neurological weakness.ConclusionsThe use of CT/MRI for evaluation of atraumatic headache increased dramatically in EDs in the USA between 1998 and 2008. The prevalence of ICP among patients who received CT/MRI declined concurrently, suggesting a role for clinical decision support to guide more judicious use of imaging.
Republished review: Systematic review and meta-analysis of psychomotor effects of mobile phone electromagnetic fields
Authors: Valentini Elia , Ferrara Michele , Presaghi Fabio , De Gennaro Luigi , Curcio Giuseppe 
Published: August 2011

ABSTRACT

Objectives
Over the past 10 years there has been increasing concern about the possible behavioural effects of mobile phone use. This systematic review and meta-analysis focuses on studies published since 1999 on the human cognitive and performance effects of mobile phone-related electromagnetic fields (EMF).

Methods
PubMed, Biomed, Medline, Biological Sciences, PsychInfo, PsycARTICLES, Environmental Sciences and Pollution Management, Neurosciences Abstracts and Web of Science professional databases were searched and 24 studies selected for meta-analysis. Each study had to have at least one psychomotor measurement result as a main outcome. Data were analysed using standardised mean difference (SMD) as the effect size measure.

Results
Only three tasks (2-back, 3-back and simple reaction time (SRT)) displayed significant heterogeneity, but after studies with extreme SMD were excluded using sensitivity analysis, the statistical significance disappeared (χ2(7)=1.63, p=0.20; χ2(6)=1.00, p=0.32; χ2(10)=14.04, p=0.17, respectively). Following sensitivity analysis, the effect of sponsorship and publication bias were assessed. Meta-regression indicated a significant effect (b1/40.12, p&lt;0.05) only for the 2-back task with mixed funding (industry and public/charity). Funnel plot inspection revealed a significant publication bias only for two cognitive tasks: SRT (Begg’s rank correlation r=0.443; Egger’s test b=−0.652) and the subtraction task (Egger’s test b=−0.687).

Conclusions
Mobile phone-like EMF do not seem to induce cognitive and psychomotor effects. Nonetheless, the existence of sponsorship and publication biases should encourage WHO intervention to develop official research standards and guidelines. In addition, future research should address critical and neglected issues such as investigation of repeated, intensive and chronic exposures, especially in highly sensitive populations such as children.
RANDOM MATRICES: UNIVERSAL PROPERTIES OF EIGENVECTORS
Authors: TAO TERENCE , VU VAN 
Published: August 2011

The four moment theorem asserts, roughly speaking, that the joint distribution of a small number of eigenvalues of a Wigner random matrix (when measured at the scale of the mean eigenvalue spacing) depends only on the first four moments of the entries of the matrix. In this paper, we extend the four moment theorem to also cover the coefficients of the eigenvectors of a Wigner random matrix. A similar result (with different hypotheses) has been proved recently by Knowles and Yin, using a different method. As an application, we prove some central limit theorems for these eigenvectors. In another application, we prove a universality result for the resolvent, up to the real axis. This implies universality of the inverse matrix.
Therapeutic Effect of Lenalidomide in a Novel Xenograft Mouse Model of Human Blastic NK Cell Lymphoma/Blastic Plasmacytoid Dendritic Cell Neoplasm
Authors: Agliano Alice , Martin-Padura Ines , Marighetti Paola , Gregato Giuliana , Calleri Angelica , Prior Celia , Redrado Miriam , Calvo Alfonso , Bertolini Francesco 
Published: August 2011

AbstractPurpose: Blastic natural killer (NK) cell lymphoma/blastic plasmacytoid dendritic cell neoplasm (BNKL) is a rare and aggressive neoplasia characterized by infiltration of blast CD4+/CD56+ cells in the skin, the bone marrow, and peripheral blood. Currently, more efforts are required to better define molecular and biological mechanisms associated with this pathology. To the best of our knowledge, no mouse model recapitulated human BNKL so far.Experimental Design: Primary bone marrow cells from a BNKL patient were injected in nonobese diabetes/severe combined immunodeficient interleukin (IL) 2rγ−/− mice with the intent to generate the first BNKL orthotopic mouse model. Moreover, because of the lack of efficient treatments for BNKL, we treated mice with lenalidomide, an immunomodulatory and antiangiogenic drug.Results: We generated in mice a fatal disease resembling human BNKL. After lenalidomide treatment, we observed a significant reduction in the number of peripheral blood, bone marrow, and spleen BNKL cells. Tumor reduction parallels with a significant decrease in the number of circulating endothelial and progenitor cells and CD31+ murine endothelial cells. In mice treated with lenalidomide, BNKL levels of active caspase-3 were significantly augmented, thus showing proapoptotic and cytotoxic effects of this drug in vivo. An opposite result was found for proliferating cell nuclear antigen, a proliferation marker.Conclusions: Our BNKL model might better define the cellular and molecular mechanisms involved in this disease, and lenalidomide might be considered for the future therapy of BNKL patients. Clin Cancer Res; 17(19); 6163–73. ©2011 AACR.
Significant Biological Role of Sp1 Transactivation in Multiple Myeloma
Authors: Fulciniti Mariateresa , Amin Samir , Nanjappa Puru , Rodig Scott , Prabhala Rao , Li Cheng , Minvielle Stephane , Tai Yu-tzu , Tassone Pierfrancesco , Avet-Loiseau Herve , Hideshima Teru , Anderson Kenneth C. , Munshi Nikhil C. 
Published: August 2011

AbstractPurpose: The transcription factor specificity protein 1 (Sp1) controls number of cellular processes by regulating the expression of critical cell cycle, differentiation, and apoptosis-related genes containing proximal GC/GT-rich promoter elements. We here provide experimental and clinical evidence that Sp1 plays an important regulatory role in multiple myeloma (MM) cell growth and survival.Experimental Design: We have investigated the functional Sp1 activity in MM cells using a plasmid with Firefly luciferase reporter gene driven by Sp1-responsive promoter. We have also used both siRNA- and short hairpin RNA–mediated Sp1 knockdown to investigate the growth and survival effects of Sp1 on MM cells and further investigated the anti-MM activity of terameprocol (TMP), a small molecule that specifically competes with Sp1-DNA binding in vitro and in vivo.Results: We have confirmed high Sp1 activity in MM cells that is further induced by adhesion to bone marrow stromal cells (BMSC). Sp1 knockdown decreases MM cell proliferation and induces apoptosis. Sp1-DNA binding inhibition by TMP inhibits MM cell growth both in vitro and in vivo, inducing caspase-9–dependent apoptosis and overcoming the protective effects of BMSCs.Conclusions: Our results show Sp1 as an important transcription factor in myeloma that can be therapeutically targeted for clinical application by TMP. Clin Cancer Res; 17(20); 6500–9. ©2011 AACR.