bluuebunny/crossref_metadata_2025_split huggingface dataset:
Microemulsion Synthesis of Nanosized TiO2 Particles Doping with Rare‐Earth and their Photocatalytic Activity
Authors: Jian Zicong , Pu Yuying , Fang Jianzhang , Ye Zhiping 
Published: July 2010

AbstractMicroemulsion is the easiest and cleanest of the popular methods of synthesizing nanomaterial. This work synthesized the nanosized La‐TiO2 and Ce‐TiO2 particles through the hydrolyzation of tetrabutyl titanate in a Triton X‐100/n‐hexanol/cyclohexane/water reverse microemulsion. The particles were characterized by X‐ray diffraction (XRD), transmission electron microscopy (TEM), Fourier transform‐infrared spectroscopy (FT‐IR) and thermogravimetry (TG). The photocatalytic activity was evaluated by photocatalytic degradation of methyl orange (MO) under ultraviolet light and visible light irradiation. The results showed that reverse microemulsion produced the nanosized and well‐separated particles, which are obviously in degrading MO. Comparing the pure TiO2 with doping TiO2, the doping ones are smaller and have better photocatalytic activity, which was best at the molar content of 0.1% for La, whereas for Ce it was 0.5%.
Characterization of the RND family of multidrug efflux pumps: in silico to in vivo confirmation of four functionally distinct subgroups
Authors: Godoy Patricia , Molina‐Henares Antonio J. , De La Torre Jesús , Duque Estrella , Ramos Juan L. 
Published: July 2010

SummaryWe have developed a generalized profile that identifies members of the root‐nodulation‐cell‐division (RND) family of efflux pumps and classifies them into four functional subfamilies. According to Z‐score values, efflux pumps can be grouped by their metabolic function, thus making it possible to distinguish pumps involved in antibiotic resistance (group 1) from those involved in metal resistance (group 3). In silico data regarding efflux pumps in group 1 were validated after identification of RND efflux pumps in a number of environmental microbes that were isolated as resistant to ethidium bromide. Analysis of the Pseudomonas putida KT2440 genome identified efflux pumps in all groups. A collection of mutants in efflux pumps and a screening platform consisting of 50 drugs were created to assign a function to the efflux pumps. We validated in silico data regarding efflux pumps in groups 1 and 3 using 9 different mutants. Four mutants belonging to group 2 were found to be more sensitive than the wild‐type to oxidative stress‐inducing agents such as bipyridyl and methyl viologen. The two remaining mutants belonging to group 4 were found to be more sensitive than the parental to tetracycline and one of them was particularly sensitive to rubidium and chromate. By effectively combining in vivo data with generalized profiles and gene annotation data, this approach allowed the assignment, according to metabolic function, of both known and uncharacterized RND efflux pumps into subgroups, thereby providing important new insight into the functions of proteins within this family.
Methicillin‐Resistant Staphylococcus aureus (MRSA) in Three Dairy Herds in Southwest Germany
Authors: Spohr M. , Rau J. , Friedrich A. , Klittich G. , Fetsch A. , Guerra B. , Hammerl J. A. , Tenhagen B.‐A. 
Published: July 2010

SummaryThe objective of this study was to analyse the occurrence of methicillin‐resistant Staphylococcus aureus (MRSA) in three dairy herds in the southwest of Germany that had experienced individual cases of clinical and subclinical mastitis associated with MRSA. The herds were identified by the detection of MRSA during routine resistance testing of mastitis pathogens. All quarters of all cows in the herds that were positive on California Mastitis Test were sampled for bacteriological analysis on two occasions. Bulk tank milk samples were also tested. Furthermore, nasal swabs were collected from people working on the farms and from cattle. Environmental samples were collected from associated pig holdings. Isolates were characterized using spa‐typing and testing for antimicrobial resistance. Our results revealed a substantial spread of MRSA in the three dairy herds. In the first of the two investigations carried out on all cows in the three herds, milk samples of 5.1–16.7% of dairy cows were found positive for MRSA. The respective proportions in the second herd level investigation were 1.4–10.0%. Quarters harbouring MRSA had higher somatic cell counts than quarters that were negative on culture. Methicillin‐resistant Staphylococcus aureus were also detected in nasal swabs of staff (7/9), cows (7/15) and calves (4/7), bulk tank milk samples (3/3) and environmental samples from pig premises (4/5) on the farm. Herds B and C had no contact to herd A. However, in all three herds MRSA of spa‐type t011 were detected in milk samples. Results show that MRSA of spa‐type t011 is a problem in dairy farms that needs urgent attention.
Exposure to Bioaerosols during the Growth Season of Tomatoes in an Organic Greenhouse Using Supresivit (
Trichoderma harzianum
) and Mycostop (
Streptomyces griseoviridis
)
Authors: Hansen Vinni Mona , Winding Anne , Madsen Anne Mette 
Published: July 2010

ABSTRACT

In working environments, especially in confined spaces like greenhouses, elevated concentrations of airborne microorganisms may become a problem for workers' health. Additionally, the use of microbial pest control agents (MPCAs) may increase exposure to microorganisms. The aim of this study was to investigate tomato growers' exposure to naturally occurring bioaerosol components [dust, bacteria, fungi, actinomycetes, (1→3)-β-
d
-glucans, and endotoxin] and MPCAs applied by drip irrigation. Airborne dust was collected with filter samplers and analyzed for microorganisms by plate counts and total counts using a microscope. Analysis of (1→3)-β-
d
-glucan and endotoxin content was performed by kinetic, chromatic
Limulus
amoebocyte lysate tests. The fungal strain (
Trichoderma harzianum
) from the biocontrol product Supresivit was identified by PCR analysis. Measurements were performed on the day of drip irrigation and 1 week, 1 month, and 3 months after the irrigation.
T. harzianum
from Supresivit could be detected only on the day of treatment.
Streptomyces griseoviridis
, an applied MPCA, was not detected in the air during this investigation. We found that bioaerosol exposure increases during the growth season and that exposure to fungi, bacteria, and endotoxin can reach levels during the harvest period that may cause respiratory symptoms in growers. The collected data indicate that MPCAs applied by drip irrigation do not become airborne later in the season.
Exploring the Role of Microorganisms in the Disease-Like Syndrome Affecting the Sponge
Ianthella basta
Authors: Luter Heidi M. , Whalan Steve , Webster Nicole S. 
Published: July 2010

ABSTRACT

A disease-like syndrome is currently affecting a large percentage of the
Ianthella basta
populations from the Great Barrier Reef and central Torres Strait. Symptoms of the syndrome include discolored, necrotic spots leading to tissue degradation, exposure of the skeletal fibers, and disruption of the choanocyte chambers. To ascertain the role of microbes in the disease process, a comprehensive comparison of bacteria, viruses, fungi, and other eukaryotes was performed in healthy and diseased sponges using multiple techniques. A low diversity of microbes was observed in both healthy and diseased sponge communities, with all sponges dominated by an
Alphaproteobacteria
, a
Gammaproteobacteria
, and a group I crenarchaeota. Bacterial cultivation, community analysis by denaturing gradient gel electrophoresis (
Bacteria
and
Eukarya
), sequencing of 16S rRNA clone libraries (
Bacteria
and
Archaea
), and direct visual assessment by electron microscopy failed to reveal any putative pathogens. In addition, infection assays could not establish the syndrome in healthy sponges even after direct physical contact with affected tissue. These results suggest that microbes are not responsible for the formation of brown spot lesions and necrosis in
I. basta
.
Rapid Multiplex Detection and Differentiation of
Listeria
Cells by Use of Fluorescent Phage Endolysin Cell Wall Binding Domains
Authors: Schmelcher Mathias , Shabarova Tatiana , Eugster Marcel R. , Eichenseher Fritz , Tchang Vincent S. , Banz Manuel , Loessner Martin J. 
Published: July 2010

ABSTRACT

The genus
Listeria
comprises food-borne pathogens associated with severe infections and a high mortality rate. Endolysins from bacteriophages infecting
Listeria
are promising tools for both their detection and control. These proteins feature a modular organization, consisting of an N-terminal enzymatically active domain (EAD), which contributes lytic activity, and a C-terminal cell wall binding domain (CBD), which targets the lysin to its substrate. Sequence comparison among 12 different endolysins revealed high diversity among the enzyme's functional domains and allowed classification of their CBDs into two major groups and five subclasses. This diversity is reflected in various binding properties, as determined by cell wall binding assays using CBDs fused to fluorescent marker proteins. Although some proteins exhibited a broad binding range and recognize
Listeria
strains representing all serovars, others target specific serovars only. The CBDs also differed with respect to the number and distribution of ligands recognized on the cells, as well as their binding affinities. Surface plasmon resonance analysis revealed equilibrium affinities in the pico- to nanomolar ranges for all proteins except CBD006, which is due to an internal truncation. Rapid multiplexed detection and differentiation of
Listeria
strains in mixed bacterial cultures was possible by combining CBDs of different binding specificities with fluorescent markers of various colors. In addition, cells of different
Listeria
strains could be recovered from artificially contaminated milk or cheese by CBD-based magnetic separation by using broad-range CBDP40 and subsequently identified after incubation with two differently colored CBD fusion proteins of higher specificity.
Diversity of Glycosyl Hydrolases from Cellulose-Depleting Communities Enriched from Casts of Two Earthworm Species
Authors: Beloqui Ana , Nechitaylo Taras Y. , López-Cortés Nieves , Ghazi Azam , Guazzaroni María-Eugenia , Polaina Julio , Strittmatter Axel W. , Reva Oleg , Waliczek Agnes , Yakimov Michail M. , Golyshina Olga V. , Ferrer Manuel , Golyshin Peter N. 
Published: July 2010

ABSTRACTThe guts and casts of earthworms contain microbial assemblages that process large amounts of organic polymeric substrates from plant litter and soil; however, the enzymatic potential of these microbial communities remains largely unexplored. In the present work, we retrieved carbohydrate-modifying enzymes through the activity screening of metagenomic fosmid libraries from cellulose-depleting microbial communities established with the fresh casts of two earthworm species,Aporrectodea caliginosaandLumbricus terrestris, as inocula. Eight glycosyl hydrolases (GHs) from theA. caliginosa-derived community were multidomain endo-β-glucanases, β-glucosidases, β-cellobiohydrolases, β-galactosidase, and β-xylosidases of known GH families. In contrast, two GHs derived from theL. terrestrismicrobiome had no similarity to any known GHs and represented two novel families of β-galactosidases/α-arabinopyranosidases. Members of these families were annotated in public databases as conserved hypothetical proteins, with one being structurally related to isomerases/dehydratases. This study provides insight into their biochemistry, domain structures, and active-site architecture. The two communities were similar in bacterial composition but significantly different with regard to their eukaryotic inhabitants. Further sequence analysis of fosmids and plasmids bearing the GH-encoding genes, along with oligonucleotide usage pattern analysis, suggested that those apparently originated fromGammaproteobacteria(pseudomonads andCellvibrio-like organisms),Betaproteobacteria(Comamonadaceae), andAlphaproteobacteria(Rhizobiales).
In Vivo
Biotinylation of Bacterial Magnetic Particles by a Truncated Form of
Escherichia coli
Biotin Ligase and Biotin Acceptor Peptide
Authors: Maeda Yoshiaki , Yoshino Tomoko , Matsunaga Tadashi 
Published: July 2010

ABSTRACT

Escherichia coli
biotin ligase can attach biotin molecules to a lysine residue of biotin acceptor peptide (BAP), and biotinylation of particular BAP-fused proteins in cells was carried out by coexpression of
E. coli
biotin ligase (
in vivo
biotinylation). This
in vivo
biotinylation technology has been applied for protein purification, analysis of protein localization, and protein-protein interaction in eukaryotic cells, while such studies have not been reported in bacterial cells. In this study,
in vivo
biotinylation of bacterial magnetic particles (BacMPs) synthesized by
Magnetospirillum magneticum
AMB-1 was attempted by heterologous expression of
E. coli
biotin ligase. To biotinylate BacMPs
in vivo
, BAP was fused to a BacMP surface protein, Mms13, and
E. coli
biotin ligase was simultaneously expressed in the truncated form lacking the DNA-binding domain. This truncation-based approach permitted the growth of AMB-1 transformants when biotin ligase was heterologously expressed.
In vivo
biotinylation of BAP on BacMPs was confirmed using an alkaline phosphatase-conjugated antibiotin antibody. The biotinylated BAP-displaying BacMPs were then exposed to streptavidin by simple mixing. The streptavidin-binding capacity of BacMPs biotinylated
in vivo
was 35-fold greater than that of BacMPs biotinylated
in vitro
, where BAP-displaying BacMPs purified from bacterial cells were biotinylated by being mixed with
E. coli
biotin ligase. This study describes not only a simple method to produce biotinylated nanomagnetic particles but also a possible expansion of
in vivo
biotinylation technology for bacterial investigation.
Effective Gene Silencing in a Microsporidian Parasite Associated with Honeybee (
Apis mellifera
) Colony Declines
Authors: Paldi Nitzan , Glick Eitan , Oliva Maayan , Zilberberg Yaron , Aubin Lucie , Pettis Jeffery , Chen Yanping , Evans Jay D. 
Published: July 2010

ABSTRACT

Honeybee colonies are vulnerable to parasites and pathogens ranging from viruses to vertebrates. An increasingly prevalent disease of managed honeybees is caused by the microsporidian
Nosema ceranae
. Microsporidia are basal fungi and obligate parasites with much-reduced genomic and cellular components. A recent genome-sequencing effort for
N. ceranae
indicated the presence of machinery for RNA silencing in this species, suggesting that RNA interference (RNAi) might be exploited to regulate
Nosema
gene expression within bee hosts. Here we used controlled laboratory experiments to show that double-stranded RNA homologous to specific
N. ceranae
ADP/ATP transporter genes can specifically and differentially silence transcripts encoding these proteins. This inhibition also affects
Nosema
levels and host physiology. Gene silencing could be mediated solely by
Nosema
or in concert with known systemic RNAi mechanisms in their bee hosts. These results are novel for the microsporidia and provide a possible avenue for controlling a disease agent implicated in severe honeybee colony losses. Moreover, since microsporidia are pathogenic in several known veterinary and human diseases, this advance may have broader applications in the future for disease control.
Identification and Characterization of a Phosphodiesterase That Inversely Regulates Motility and Biofilm Formation in
Vibrio cholerae
Authors: Liu Xianxian , Beyhan Sinem , Lim Bentley , Linington Roger G. , Yildiz Fitnat H. 
Published: July 2010

ABSTRACT

Vibrio cholerae
switches between free-living motile and surface-attached sessile lifestyles. Cyclic diguanylate (c-di-GMP) is a signaling molecule controlling such lifestyle changes. C-di-GMP is synthesized by diguanylate cyclases (DGCs) that contain a GGDEF domain and is degraded by phosphodiesterases (PDEs) that contain an EAL or HD-GYP domain. We constructed in-frame deletions of all
V. cholerae
genes encoding proteins with GGDEF and/or EAL domains and screened mutants for altered motility phenotypes. Of 52 mutants tested, four mutants exhibited an increase in motility, while three mutants exhibited a decrease in motility. We further characterized one mutant lacking VC0137 (
cdgJ
), which encodes an EAL domain protein. Cellular c-di-GMP quantifications and
in vitro
enzymatic activity assays revealed that CdgJ functions as a PDE. The
cdgJ
mutant had reduced motility and exhibited a small decrease in
flaA
expression; however, it was able to produce a flagellum. This mutant had enhanced biofilm formation and
vps
gene expression compared to that of the wild type, indicating that CdgJ inversely regulates motility and biofilm formation. Genetic interaction analysis revealed that at least four DGCs, together with CdgJ, control motility in
V. cholerae
.
Localization and Cellular Amounts of the WalRKJ (VicRKX) Two-Component Regulatory System Proteins in Serotype 2Streptococcus pneumoniae
Authors: Wayne Kyle J. , Sham Lok-To , Tsui Ho-Ching T. , Gutu Alina D. , Barendt Skye M. , Keen Susan K. , Winkler Malcolm E. 
Published: July 2010

ABSTRACTThe WalRK two-component regulatory system coordinates gene expression that maintains cell wall homeostasis and responds to antibiotic stress in low-GC Gram-positive bacteria. Phosphorylated WalR (VicR) of the major human respiratory pathogenStreptococcus pneumoniae(WalRSpn) positively regulates transcription of several surface virulence genes and, most critically,pcsB, which encodes an essential cell division protein. Despite numerous studies of several species, little is known about the signals sensed by the WalK histidine kinase or the function of the WalJ ancillary protein encoded in thewalRKSpnoperon. To better understand the functions of the WalRKJSpnproteins inS. pneumoniae, we performed experiments to determine their cellular localization and amounts. In contrast to WalK fromBacillus subtilis(WalKBsu), which is localized at division septa, immunofluorescence microscopy showed that WalKSpnis distributed throughout the cell periphery. WalJSpnis also localized to the cell surface periphery, whereas WalRSpnwas found to be localized in the cytoplasm around the nucleoid. In fractionation experiments, WalRSpnwas recovered from the cytoplasmic fraction, while WalKSpnand the majority of WalJSpnwere recovered from the cell membrane fraction. This fractionation is consistent with the localization patterns observed. Lastly, we determined the cellular amounts of WalRKJSpnby quantitative Western blotting. The WalRSpnresponse regulator is relatively abundant and present at levels of ≈6,200 monomers per cell, which are ≈14-fold greater than the amount of the WalKSpnhistidine kinase, which is present at ≈460 dimers (920 monomers) per cell. We detected ≈1,200 monomers per cell of WalJSpnancillary protein, similar to the amount of WalKSpn.
Novel Approach to Early Detection of Doxorubicin Cardiotoxicity by Gadolinium-Enhanced Cardiovascular Magnetic Resonance Imaging in an Experimental Model
Authors: Lightfoot James C. , D'Agostino Ralph B. , Hamilton Craig A. , Jordan Jennifer , Torti Frank M. , Kock Nancy D. , Jordan James , Workman Susan , Hundley W. Gregory 
Published: July 2010

Background—
We sought to determine whether cardiovascular magnetic resonance measures of gadolinium (Gd) signal intensity (SI) within the left ventricular myocardium are associated with future changes in left ventricular ejection fraction (LVEF) after receipt of doxorubicin (DOX).

Methods and Results—

Forty Sprague-Dawley rats were divided into 3 groups scheduled to receive weekly intravenous doses of normal saline (n=7), 1.5 mg/kg DOX (n=19), or 2.5 mg/kg DOX (n=14). Magnetic resonance determinations of LVEF and myocardial Gd-SI were performed before and at 2, 4, 7, and 10 weeks after DOX initiation. During treatment, animals were euthanized at different time points so that histopathologic assessments of the left ventricular myocardium could be obtained. Within-group analyses were performed to examine time-dependent relations between Gd-SI and primary events (deterioration in LVEF or an unanticipated death). Six of 19 animals receiving 1.5 mg/kg DOX and 10 of 14 animals receiving 2.5 mg/kg DOX experienced a primary event; no normal saline animals experienced a primary event. In animals with a primary event, histopathologic evidence of myocellular vacuolization occurred (
P
=0.04), and the Gd-SI was elevated relative to baseline at the time of the event (
P
<0.0001) and during the measurement period before the event (
P
=0.0001). In all animals (including normal saline) without an event, measures of Gd-SI did not differ from baseline.

Conclusions—
After DOX, low serial measures of Gd-SI predict an absence of an LVEF drop or unanticipated death. An increase in Gd-SI after DOX forecasts a subsequent drop in LVEF as well as histopathologic evidence of intracellular vacuolization consistent with DOX cardiotoxicity.
Introduction to Hepatic Drug Metabolizing Enzyme Induction in Drug Safety Evaluation Studies
Authors: Botts Suzanne , Ennulat Daniela , Francke-Carroll Sabine , Graham Mark , Maronpot Robert R. , Mohutsky Michael 
Published: July 2010

The following three articles represent the output of a combined effort initiated by the Scientific Regulatory Policy Committee of the Society of Toxicologic Pathology to provide a unified review of current scientific practices and relevant literature and provide suggestions regarding the recognition, interpretation, and risk assessment of hepatic drug metabolizing enzyme (DME) induction studies. The core objective was to provide a review that the scientific community including pathologists, regulatory scientists, toxicologists, investigative scientists, and others would find valuable for managing, designing, and interpreting toxicity studies supporting regulatory filings. Three working groups composed of scientists from industry, academia, and regulatory agencies were convened to review the available literature on important aspects of the interpretation and risk assessment of hepatic microsomal DME enzyme induction in three publications. The three reviews are as follows: “Effects of Hepatic Drug Metabolizing Enzyme Induction on Clinical Pathology Parameters in Animals and Man,” Toxicol Pathol “Hepatic Drug Metabolizing Enzyme Induction: Microscopic and Ultrastructural Appearance,” Toxicol Pathol “Hepatic Drug Metabolizing Enzyme Induction and Implications for Preclinical and Clinical Risk Assessment,” Toxicol Pathol The purpose of this introduction is not to summarize the articles but rather to frame the series and to provide a common mechanistic introduction.
Loss of the SIN3 transcriptional corepressor results in aberrant mitochondrial function
Authors: Barnes Valerie L , Strunk Bethany S , Lee Icksoo , Hüttemann Maik , Pile Lori A 
Published: July 2010

Abstract

Background
SIN3 is a transcriptional repressor protein known to regulate many genes, including a number of those that encode mitochondrial components.

Results
By monitoring RNA levels, we find that loss of SIN3 in Drosophila cultured cells results in up-regulation of not only nuclear encoded mitochondrial genes, but also those encoded by the mitochondrial genome. The up-regulation of gene expression is accompanied by a perturbation in ATP levels in SIN3-deficient cells, suggesting that the changes in mitochondrial gene expression result in altered mitochondrial activity. In support of the hypothesis that SIN3 is necessary for normal mitochondrial function, yeast sin3 null mutants exhibit very poor growth on non-fermentable carbon sources and show lower levels of ATP and reduced respiration rates.

Conclusions
The findings that both yeast and Drosophila SIN3 affect mitochondrial activity suggest an evolutionarily conserved role for SIN3 in the control of cellular energy production.