bluuebunny/crossref_metadata_2025_split huggingface dataset:
Tonic muscle pain does not increase fusimotor drive to human leg muscles: implications for chronic muscle pain
Authors: Fazalbhoy Azharuddin , Macefield Vaughan G. , Birznieks Ingvars 
Published: February 2013

New Findings
What is the central question of this study?Based on data obtained from experimental animals, muscle pain is believed to cause a reflex activation of fusimotor neurones and thereby increase the sensitivity of muscle spindles to stretch. Using a model of long‐lasting muscle pain, we asked the question: does tonic muscle pain increase the resting discharge of muscle spindles in human subjects?
What is the main finding and its importance?Microelectrode recordings from single muscle spindle afferents revealed no net change in the discharge of spontaneously active spindle endings during moderate–strong pain lasting ∼1 h. We conclude that, unlike the situation in anaesthetized animals, muscle pain does not cause a reflex increase in fusimotor drive and spindle discharge.
Experimental pain induced in animals has shown that noxious stimulation of group III and IV afferents increases the firing of muscle spindles via a reflex excitation of fusimotor (γ) motoneurones. Chronic muscle pain has been hypothesized to develop as a result of a vicious cycle involving this mechanism. In order to explore the effects of long‐lasting muscle pain on the fusimotor system, single unit muscle spindle afferents were recorded from 15 subjects. Afferent activity was recorded from foot and ankle extensor muscles whilst infusing hypertonic saline into the tibialis anterior muscle of the ipsilateral leg, producing moderate–strong pain lasting for ∼60 min. A change in fusimotor drive was inferred by observing changes in the mean discharge rate of spontaneously active muscle spindle afferents. Homonymous and heteronymous muscles remained relaxed and showed no increase in activity, arguing against any fusimotor‐driven increase in motor activity, and there was no net change in the firing of muscle spindle afferents. We conclude that long‐lasting stimulation of group III and IV afferents fails to excite fusimotor neurones and increase muscle spindle discharge. Accordingly, the vicious cycle theory has no functional basis for the development of myalgia in human subjects.
Metabolic Responses of Saccharomyces cerevisiae to Valine and Ammonium Pulses during Four-Stage Continuous Wine Fermentations
Authors: Clement T. , Perez M. , Mouret J. R. , Sanchez I. , Sablayrolles J. M. , Camarasa C. 
Published: February 2013

ABSTRACTNitrogen supplementation, which is widely used in winemaking to improve fermentation kinetics, also affects the products of fermentation, including volatile compounds. However, the mechanisms underlying the metabolic response of yeast to nitrogen additions remain unclear. We studied the consequences forSaccharomyces cerevisiaemetabolism of valine and ammonium pulses during the stationary phase of four-stage continuous fermentation (FSCF). This culture technique provides cells at steady state similar to that of the stationary phase of batch wine fermentation. Thus, the FSCF device is an appropriate and reliable tool for individual analysis of the metabolic rerouting associated with nutrient additions, in isolation from the continuous evolution of the environment in batch processes. Nitrogen additions, irrespective of the nitrogen-containing compound added, substantially modified the formation of fermentation metabolites, including glycerol, succinate, isoamyl alcohol, propanol, and ethyl esters. This flux redistribution, fulfilling the requirements for precursors of amino acids, was consistent with increased protein synthesis resulting from increased nitrogen availability. Valine pulses, less efficient than ammonium addition in increasing the fermentation rate, were followed by a massive conversion of this amino acid in isobutanol and isobutyl acetate through the Ehrlich pathway. However, additional routes were involved in valine assimilation when added in stationary phase. Overall, we found that particular metabolic changes may be triggered according to the nature of the amino acid supplied, in addition to the common response. Both these shared and specific modifications should be considered when designing strategies to modulate the production of volatile compounds, a current challenge for winemakers.
Light-Dependent Functions of the Fusarium fujikuroi CryD DASH Cryptochrome in Development and Secondary Metabolism
Authors: Castrillo Marta , García-Martínez Jorge , Avalos Javier 
Published: February 2013

ABSTRACTDASH (Drosophila,Arabidopsis,Synechocystis, human) cryptochromes (cry-DASHs) constitute a subgroup of the photolyase cryptochrome family with diverse light-sensing roles, found in most taxonomical groups. The genome ofFusarium fujikuroi, a phytopathogenic fungus with a rich secondary metabolism, contains a gene encoding a putative cry-DASH, named CryD. The expression of thecryDgene is induced by light in the wild type, but not in mutants of the “white collar” genewcoA. Targeted ΔcryDmutants show light-dependent phenotypic alterations, including changes in morphology and pigmentation, which disappear upon reintroduction of a wild-typecryDallele. In addition to microconidia, the colonies of the ΔcryDmutants produced under illumination and nitrogen starvation large septated spores called macroconidia, absent in wild-type colonies. The ΔcryDmutants accumulated similar amounts of carotenoids to the control strain under constant illumination, but produced much larger amounts of bikaverin under nitrogen starvation, indicating a repressing role for CryD in this biosynthetic pathway. Additionally, a moderate photoinduction of gibberellin production was exhibited by the wild type but not by the ΔcryDmutants. The phenotypic alterations of the ΔcryDmutants were only noticeable in the light, as expected from the low expression ofcryDin the dark, but did not correlate with mRNA levels for structural genes of the bikaverin or gibberellin biosynthetic pathways, suggesting the participation of CryD in posttranscriptional regulatory mechanisms. This is the first report on the participation of a cry-DASH protein in the regulation of fungal secondary metabolism.
Evaluation of Bovine Feces-Associated Microbial Source Tracking Markers and Their Correlations with Fecal Indicators and Zoonotic Pathogens in a Brisbane, Australia, Reservoir
Authors: Ahmed W. , Sritharan T. , Palmer A. , Sidhu J. P. S. , Toze S. 
Published: February 2013

ABSTRACT

This study was aimed at evaluating the host specificity and host sensitivity of two bovine feces-associated bacterial (BacCow-UCD and cowM3) and one viral [bovine adenovirus (B-AVs)] microbial source tracking (MST) markers by screening 130 fecal and wastewater samples from 10 target and nontarget host groups in southeast Queensland, Australia. In addition, 36 water samples were collected from a reservoir and tested for the occurrence of all three bovine feces-associated markers along with fecal indicator bacteria (FIB),
Campylobacter
spp.,
Escherichia coli
O157, and
Salmonella
spp. The overall host specificity values of the BacCow-UCD, cowM3, and B-AVs markers to differentiate between bovine and other nontarget host groups were 0.66, 0.88, and 1.00, respectively (maximum value of 1.00). The overall host sensitivity values of these markers, however, in composite bovine wastewater and individual bovine fecal DNA samples were 0.93, 0.90, and 0.60, respectively (maximum value of 1.00). Among the 36 water samples tested, 56%, 22%, and 6% samples were PCR positive for the BacCow-UCD, cowM3, and B-AVs markers, respectively. Among the 36 samples tested, 50% and 14% samples were PCR positive for the
Campylobacter
16S rRNA and
E. coli
O157
rfbE
genes, respectively. Based on the results, we recommend that multiple bovine feces-associated markers be used if possible for bovine fecal pollution tracking. Nonetheless, the presence of the multiple bovine feces-associated markers along with the presence of potential zoonotic pathogens indicates bovine fecal pollution in the reservoir water samples. Further research is required to understand the decay rates of these markers in relation to FIB and zoonotic pathogens.
Utilization of Virus ϕCh1 Elements To Establish a Shuttle Vector System for Halo(alkali)philic Archaea via Transformation of Natrialba magadii
Authors: Mayrhofer-Iro M. , Ladurner A. , Meissner C. , Derntl C. , Reiter M. , Haider F. , Dimmel K. , Rössler N. , Klein R. , Baranyi U. , Scholz H. , Witte A. 
Published: February 2013

ABSTRACT

In the study described here, we successfully developed a transformation system for halo(alkali)philic members of the
Archaea
. This transformation system comprises a series of
Natrialba magadii
/
Escherichia coli
shuttle vectors based on a modified method to transform halophilic members of the
Archaea
and genomic elements of the
N. magadii
virus ϕCh1. The shuttle vector pRo-5, based on the
repH
-containing region of ϕCh1, stably replicated in
E. coli
and
N. magadii
and in several halophilic and haloalkaliphilic members of the
Archaea
not transformable so far. The ϕCh1 operon ORF53/ORF54 (
repH
) was essential for pRo-5 replication and was thus identified as the minimal replication origin. The plasmid allowed homologous and heterologous gene expression, as exemplified by the expression of ϕCh1 ORF34
52
, which encodes a structural protein, and the reporter gene
bgaH
of
Haloferax lucentense
in
N. magadii
. The new transformation/vector system will facilitate genetic studies within
N. magadii
and other haloalkaliphilic archaea and will allow the detailed characterization of the gene functions of
N. magadii
virus ϕCh1 in their extreme environments.
Revisiting Methanotrophic Communities in Sewage Treatment Plants
Authors: Ho Adrian , Vlaeminck Siegfried E. , Ettwig Katharina F. , Schneider Bellinda , Frenzel Peter , Boon Nico 
Published: February 2013

ABSTRACT
The methanotrophic potential in sewage treatment sludge was investigated. We detected a diverse aerobic methanotrophic community that potentially plays a significant role in mitigating methane emission in this environment. The results suggest that community structure was determined by conditions specific to the processes in a sewage treatment plant.
Effect of Micro- and Nanoscale Topography on the Adhesion of Bacterial Cells to Solid Surfaces
Authors: Hsu Lillian C. , Fang Jean , Borca-Tasciuc Diana A. , Worobo Randy W. , Moraru Carmen I. 
Published: February 2013

ABSTRACT

Attachment and biofilm formation by bacterial pathogens on surfaces in natural, industrial, and hospital settings lead to infections and illnesses and even death. Minimizing bacterial attachment to surfaces using controlled topography could reduce the spreading of pathogens and, thus, the incidence of illnesses and subsequent human and financial losses. In this context, the attachment of key microorganisms, including
Escherichia coli
,
Listeria innocua
, and
Pseudomonas fluorescens
, to silica and alumina surfaces with micron and nanoscale topography was investigated. The results suggest that orientation of the attached cells occurs preferentially such as to maximize their contact area with the surface. Moreover, the bacterial cells exhibited different morphologies, including different number and size of cellular appendages, depending on the topographical details of the surface to which they attached. This suggests that bacteria may utilize different mechanisms of attachment in response to surface topography. These results are important for the design of novel microbe-repellant materials.
Legionella pneumophila Transcriptional Response following Exposure to CuO Nanoparticles
Authors: Lu Jingrang , Struewing Ian , Buse Helen Y. , Kou Jiahui , Shuman Howard A. , Faucher Sébastien P. , Ashbolt Nicholas J. 
Published: February 2013

ABSTRACT

Copper ions are an effective antimicrobial agent used to control Legionnaires' disease and Pontiac fever arising from institutional drinking water systems. Here, we present data on an alternative bactericidal agent, copper oxide nanoparticles (CuO-NPs), and its efficacy on
Legionella pneumophila
. In broth cultures, the CuO-NPs caused growth inhibition, which appeared to be concentration and exposure time dependent. The transcriptomic response of
L. pneumophila
to CuO-NP exposure was investigated by using a whole-genome microarray. The expression of genes involved in metabolism, transcription, translation, DNA replication and repair, and unknown/hypothetical proteins was significantly affected by exposure to CuO-NPs. In addition, expression of 21 virulence genes was also affected by exposure to CuO-NP and further evaluated by quantitative reverse transcription-PCR (qRT-PCR). Some virulence gene responses occurred immediately and transiently after addition of CuO-NPs to the cells and faded rapidly (
icmV
,
icmW
,
lepA
), while expression of other genes increased within 6 h (
ceg29
,
legLC8
,
legP
,
lem19
,
lem24
,
lpg1689
, and
rtxA
), 12 h (
cegC1
,
dotA
,
enhC
,
htpX
,
icmE
,
pvcA
, and
sidF
), and 24 h (
legP
,
lem19
, and
ceg19
), but for most of the genes tested, expression was reduced after 24 h of exposure. Genes like
ceg29
and
rtxA
appeared to be the most responsive to CuO-NP exposures and along with other genes identified in this study may prove useful to monitor and manage the impact of drinking water disinfection on
L. pneumophila
.
Phylogenetic and Molecular Analysis of Food-Borne Shiga Toxin-Producing Escherichia coli
Authors: Hauser Elisabeth , Mellmann Alexander , Semmler Torsten , Stoeber Helen , Wieler Lothar H. , Karch Helge , Kuebler Nikole , Fruth Angelika , Harmsen Dag , Weniger Thomas , Tietze Erhard , Schmidt Herbert 
Published: February 2013

ABSTRACT

Seventy-five food-associated Shiga toxin-producing
Escherichia coli
(STEC) strains were analyzed by molecular and phylogenetic methods to describe their pathogenic potential. The presence of the locus of proteolysis activity (LPA), the chromosomal pathogenicity island (PAI) PAI I
CL3
, and the autotransporter-encoding gene
sabA
was examined by PCR. Furthermore, the occupation of the chromosomal integration sites of the locus of enterocyte effacement (LEE),
selC
,
pheU
, and
pheV
, as well as the Stx phage integration sites
yehV
,
yecE
,
wrbA
,
z2577
, and
ssrA
, was analyzed. Moreover, the antibiotic resistance phenotypes of all STEC strains were determined. Multilocus sequence typing (MLST) was performed, and sequence types (STs) and sequence type complexes (STCs) were compared with those of 42 hemolytic-uremic syndrome (HUS)-associated enterohemorrhagic
E. coli
(HUSEC) strains. Besides 59 STs and 4 STCs, three larger clusters were defined in this strain collection. Clusters A and C consist mostly of highly pathogenic
eae
-positive HUSEC strains and some related food-borne STEC strains. A member of a new O26 HUS-associated clone and the 2011 outbreak strain
E. coli
O104:H4 were found in cluster A. Cluster B comprises only
eae
-negative food-borne STEC strains as well as mainly
eae
-negative HUSEC strains. Although food-borne strains of cluster B were not clearly associated with disease, serotypes of important pathogens, such as O91:H21 and O113:H21, were in this cluster and closely related to the food-borne strains. Clonal analysis demonstrated eight closely related genetic groups of food-borne STEC and HUSEC strains that shared the same ST and were similar in their virulence gene composition. These groups should be considered with respect to their potential for human infection.
Kinetics of Ozone Inactivation of Infectious Prion Protein
Authors: Ding Ning , Neumann Norman F. , Price Luke M. , Braithwaite Shannon L. , Balachandran Aru , Mitchell Gordon , Belosevic Miodrag , Gamal El-Din Mohamed 
Published: February 2013

ABSTRACT

The kinetics of ozone inactivation of infectious prion protein (PrP
Sc
, scrapie 263K) was investigated in ozone-demand-free phosphate-buffered saline (PBS). Diluted infectious brain homogenates (IBH) (0.01%) were exposed to a predetermined ozone dose (10.8 ± 2.0 mg/liter) at three pHs (pH 4.4, 6.0, and 8.0) and two temperatures (4°C and 20°C). The inactivation of PrP
Sc
was quantified by determining the
in vitro
destruction of PrP
Sc
templating properties using the protein misfolding cyclic amplification (PMCA) assay and bioassay, which were shown to correlate well. The inactivation kinetics were characterized by both Chick-Watson (CW) and efficiency factor Hom (EFH) models. It was found that the EFH model fit the experimental data more appropriately. The efficacy of ozone inactivation of PrP
Sc
was both pH and temperature dependent. Based on the EFH model,
CT
(disinfectant concentration multiplied by contact time) values were determined for 2-log
10
, 3-log
10
, and 4-log
10
inactivation at the conditions under which they were achieved. Our results indicated that ozone is effective for prion inactivation in ozone-demand-free water and may be applied for the inactivation of infectious prion in prion-contaminated water and wastewater.
Genetic Analysis of Capsular Polysaccharide Synthesis Gene Clusters from All Serotypes of Streptococcus suis: Potential Mechanisms for Generation of Capsular Variation
Authors: Okura Masatoshi , Takamatsu Daisuke , Maruyama Fumito , Nozawa Takashi , Nakagawa Ichiro , Osaki Makoto , Sekizaki Tsutomu , Gottschalk Marcelo , Kumagai Yumi , Hamada Shigeyuki 
Published: February 2013

ABSTRACT

Streptococcus suis
strains are classified into 35 serotypes on the basis of the antigenicity of their capsular polysaccharides (CPs). CP synthesis genes are known to be clustered on the chromosome (
cps
gene cluster). The entire
cps
gene clusters of
S. suis
have so far been sequenced in 15 serotypes and found to be located between
orfZ
and
aroA
. In this study, to provide comprehensive information about
S. suis
CPs, we sequenced the entire
cps
gene clusters of the remaining serotypes and analyzed the complete set of
S. suis
cps
gene clusters. Among the 35
cps
gene clusters, 22 were located between
orfZ
and
aroA
, whereas the other 13 were flanked by other gene(s) on the chromosomes, and the chromosomal locus was classified into five patterns. By clustering analysis, the predicted products of
cps
genes found in the 35 serotypes were assigned into 291 homology groups, and all serotypes possessed a serotype-specific gene, except for serotypes 1, 2, 1/2, and 14. Because of the presence of genes encoding flippase (
wzx
) and polymerase (
wzy
), CPs of all serotypes were thought to be synthesized by the Wzx/Wzy pathway. Our data also implied the possibility of the transfer of the entire or partial
cps
gene clusters among
S. suis
strains, as well as the influence of spontaneous mutations in a single gene or a few genes on the antigenicity of some serotypes. Accumulation of these gene transfers and small-scale mutations may have generated the antigenic diversity of
S. suis
CPs.
New Constitutive Vectors: Useful Genetic Engineering Tools for Biocatalysis
Authors: Xu Youqiang , Tao Fei , Ma Cuiqing , Xu Ping 
Published: February 2013

ABSTRACT

Constitutive vectors are useful tools for genetic engineering. Two constitutive vectors with high levels of expression and broad host ranges were developed and used in a range of
Pseudomonas
hosts. The vectors showed superior characteristics compared to the inducible vectors as well as the potential to be used as improved genetic tools for biocatalysis.
Rapid Microcystis Cyanophage Gene Diversification Revealed by Long- and Short-Term Genetic Analyses of the Tail Sheath Gene in a Natural Pond
Authors: Kimura Shigeko , Sako Yoshihiko , Yoshida Takashi 
Published: February 2013

ABSTRACT

Viruses influence the abundance of host populations through virus-mediated host cell lysis. Viruses contribute to the generation and maintenance of host diversity, which also results in viral diversity throughout their coevolution. Here, to determine the phage gene diversification throughout the coevolution of host and phage in a natural environment, we investigated the genetic diversity and temporal changes in
Microcystis
cyanophage populations using a total of 810 sequences of the Ma-LMM01-type cyanophage tail sheath gene (
g91
) from 2006 to 2011 in a natural pond. The sequences obtained were highly diverse and assigned to 419 different genotypes (GT1 to GT419) clustered at 100% nucleotide sequence similarity. A maximum-parsimony network showed that the genotypes were largely divided into three sequence groups, which were dominated by major genotypes (more than 24 sequences: GT2, GT53, and GT163 in group I; GT25 in group II; and GT1 in group III). These major genotypes coexisted and oscillated throughout the sampling periods, suggesting that the
Microcystis
-cyanophage coevolution was partly driven by a negative frequency-dependent selection. Meanwhile, the high viral genetic diversity observed was derived from a large number of the variants of each major and moderately frequent genotype (including 7 to 18 sequences: GT7, GT26, GT56, GT149, and GT182 in group I; GT152 in group II) (1 or 2 nucleotide substitutions). The variants almost always co-occurred with their origin genotypes. This manner of variant emergence suggests that increased contact frequency within a host-phage population promotes rapid coevolution in a form of “arms race.”
CYP63A2, a Catalytically Versatile Fungal P450 Monooxygenase Capable of Oxidizing Higher-Molecular-Weight Polycyclic Aromatic Hydrocarbons, Alkylphenols, and Alkanes
Authors: Syed Khajamohiddin , Porollo Aleksey , Lam Ying Wai , Grimmett Paul E. , Yadav Jagjit S. 
Published: February 2013

ABSTRACT

Cytochrome P450 monooxygenases (P450s) are known to oxidize hydrocarbons, albeit with limited substrate specificity across classes of these compounds. Here we report a P450 monooxygenase (CYP63A2) from the model ligninolytic white rot fungus
Phanerochaete chrysosporium
that was found to possess a broad oxidizing capability toward structurally diverse hydrocarbons belonging to mutagenic/carcinogenic fused-ring higher-molecular-weight polycyclic aromatic hydrocarbons (HMW-PAHs), endocrine-disrupting long-chain alkylphenols (APs), and crude oil aliphatic hydrocarbon
n
-alkanes. A homology-based three-dimensional (3D) model revealed the presence of an extraordinarily large active-site cavity in CYP63A2 compared to the mammalian PAH-oxidizing (CYP3A4, CYP1A2, and CYP1B1) and bacterial aliphatic-hydrocarbon-oxidizing (CYP101D and CYP102A1) P450s. This structural feature in conjunction with ligand docking simulations suggested potential versatility of the enzyme. Experimental characterization using recombinantly expressed CYP63A2 revealed its ability to oxidize HMW-PAHs of various ring sizes, including 4 rings (pyrene and fluoranthene), 5 rings [benzo(
a
)pyrene], and 6 rings [benzo(
ghi
)perylene], with the highest enzymatic activity being toward the 5-ring PAH followed by the 4-ring and 6-ring PAHs, in that order. Recombinant CYP63A2 activity yielded monohydroxylated PAH metabolites. The enzyme was found to also act as an alkane ω-hydroxylase that oxidized
n
-alkanes with various chain lengths (C
9
to C
12
and C
15
to C
19
), as well as alkyl side chains (C
3
to C
9
) in alkylphenols (APs). CYP63A2 showed preferential oxidation of long-chain APs and alkanes. To our knowledge, this is the first P450 identified from any of the biological kingdoms that possesses such broad substrate specificity toward structurally diverse xenobiotics (PAHs, APs, and alkanes), making it a potent enzyme biocatalyst candidate to handle mixed pollution (e.g., crude oil spills).