bluuebunny/crossref_metadata_2025 huggingface dataset:
The Secreted Esterase of Propionibacterium freudenreichii Has a Major Role in Cheese Lipolysis
Authors: Abeijón Mukdsi María Claudia , Falentin Hélène , Maillard Marie-Bernadette , Chuat Victoria , Medina Roxana Beatriz , Parayre Sandrine , Thierry Anne
Published: November 2013

Free fatty acids are important flavor compounds in cheese.
Propionibacterium freudenreichii
is the main agent of their release through lipolysis in Swiss cheese. Our aim was to identify the esterase(s) involved in lipolysis by
P. freudenreichii
. We targeted two previously identified esterases: one secreted esterase, PF#279, and one putative cell wall-anchored esterase, PF#774. To evaluate their role in lipolysis, we constructed overexpression and knockout mutants of
P. freudenreichii
CIRM-BIA1
T
for each corresponding gene. The sequences of both genes were also compared in 21 wild-type strains. All strains were assessed for their lipolytic activity on milk fat. The lipolytic activity observed matched data previously reported in cheese, thus validating the relevance of the method used. The mutants overexpressing PF#279 or PF#774 released four times more fatty acids than the wild-type strain, demonstrating that both enzymes are lipolytic esterases. However, inactivation of the
pf279
gene induced a 75% reduction in the lipolytic activity compared to that of the wild-type strain, whereas inactivation of the
pf774
gene did not modify the phenotype. Two of the 21 wild-type strains tested did not display any detectable lipolytic activity. Interestingly, these two strains exhibited the same single-nucleotide deletion at the beginning of the
pf279
gene sequence, leading to a premature stop codon, whereas they harbored a
pf774
gene highly similar to that of the other strains. Taken together, these results clearly demonstrate that PF#279 is the main lipolytic esterase in
P. freudenreichii
and a key agent of Swiss cheese lipolysis.
Aeromonas hydrophila and Aeromonas veronii Predominate among Potentially Pathogenic Ciprofloxacin- and Tetracycline-Resistant Aeromonas Isolates from Lake Erie
Authors: Skwor Troy , Shinko Jasmine , Augustyniak Alexander , Gee Christopher , Andraso Greg
Published: November 2013

Members of the genus
Aeromonas
are ubiquitous in nature and have increasingly been implicated in numerous diseases of humans and other animal taxa. Although some species of aeromonads are human pathogens, their presence, density, and relative abundance are rarely considered in assessing water quality. The objectives of this study were to identify
Aeromonas
species within Lake Erie, determine their antibiotic resistance patterns, and assess their potential pathogenicity.
Aeromonas
strains were isolated from Lake Erie water by use of
Aeromonas
selective agar with and without tetracycline and ciprofloxacin. All isolates were analyzed for hemolytic ability and cytotoxicity against human epithelial cells and were identified to the species level by using 16S rRNA gene restriction fragment length polymorphisms and phylogenetic analysis based on
gyrB
gene sequences. A molecular virulence profile was identified for each isolate, using multiplex PCR analysis of six virulence genes. We demonstrated that
Aeromonas
comprised 16% of all culturable bacteria from Lake Erie. Among 119
Aeromonas
isolates, six species were identified, though only two species (
Aeromonas hydrophila
and
A. veronii
) predominated among tetracycline- and ciprofloxacin-resistant isolates. Additionally, both of these species demonstrated pathogenic phenotypes
in vitro
. Virulence gene profiles demonstrated a high prevalence of aerolysin and serine protease genes among
A. hydrophila
and
A. veronii
isolates, a genetic profile which corresponded with pathogenic phenotypes. Together, our findings demonstrate increased antibiotic resistance among potentially pathogenic strains of aeromonads, illustrating an emerging potential health concern.
Sex Determination Directs Uniparental Mitochondrial Inheritance in Phycomyces
Authors: Shakya Viplendra P. S. , Idnurm Alexander
Published: November 2013

Uniparental inheritance (UPI) of mitochondria is common among eukaryotes. The underlying molecular basis by which the sexes of the parents control this non-Mendelian pattern of inheritance is yet to be fully understood. Two major factors have complicated the understanding of the role of sex-specific genes in the UPI phenomenon: in many cases (i) fusion occurs between cells of unequal size or (ii) mating requires a large region of the genome or chromosome that includes genes unrelated to sex determination. The fungus
Phycomyces blakesleeanus
is a member of the Mucoromycotina and has a simple mating type locus encoding only one high-mobility group (HMG) domain protein, and mating occurs by fusion of isogamous cells, thus providing a model system without the limitations mentioned above. Analysis of more than 250 progeny from a series of genetic crosses between wild-type strains of
Phycomyces
revealed a correlation between the individual genes in the mating type locus and UPI of mitochondria. Inheritance is from the plus (+) sex type and is associated with degradation of the mtDNA from the minus (−) parent. These findings suggest that UPI can be directly controlled by genes that determine sex identity, independent of cell size or the complexity of the genetic composition of a sex chromosome.
PakD, a Putative p21-Activated Protein Kinase in Dictyostelium discoideum, Regulates Actin
Authors: Garcia Miguel , Ray Sibnath , Brown Isaiah , Irom Jon , Brazill Derrick
Published: November 2013

Proper regulation of the actin cytoskeleton is essential for cell function and ultimately for survival. Tight control of actin dynamics is required for many cellular processes, including differentiation, proliferation, adhesion, chemotaxis, endocytosis, exocytosis, and multicellular development. Here we describe a putative p21-activated protein kinase, PakD, that regulates the actin cytoskeleton in
Dictyostelium discoideum
. We found that cells lacking
pakD
are unable to aggregate and thus unable to develop. Compared to the wild type, cells lacking PakD have decreased membrane extensions, suggesting defective regulation of the actin cytoskeleton.
pakD
−
cells show poor chemotaxis toward cyclic AMP (cAMP) but normal chemotaxis toward folate, suggesting that PakD mediates some but not all chemotaxis responses.
pakD
−
cells have decreased polarity when placed in a cAMP gradient, indicating that the chemotactic defects of the
pakD
−
cells may be due to an impaired cytoskeletal response to cAMP. In addition, while wild-type cells polymerize actin in response to global stimulation by cAMP,
pakD
−
cells exhibit F-actin depolymerization under the same conditions. Taken together, the results suggest that PakD is part of a pathway coordinating F-actin organization during development.
Global Gene Expression and Focused Knockout Analysis Reveals Genes Associated with Fungal Fruiting Body Development in Neurospora crassa
Authors: Wang Zheng , Lopez-Giraldez Francesc , Lehr Nina , Farré Marta , Common Ralph , Trail Frances , Townsend Jeffrey P.
Published: November 2013

Fungi can serve as highly tractable models for understanding genetic basis of sexual development in multicellular organisms. Applying a reverse-genetic approach to advance such a model, we used random and multitargeted primers to assay gene expression across perithecial development in
Neurospora crassa
. We found that functionally unclassified proteins accounted for most upregulated genes, whereas downregulated genes were enriched for diverse functions. Moreover, genes associated with developmental traits exhibited stage-specific peaks of expression. Expression increased significantly across sexual development for mating type gene
mat a-1
and for
mat A-1
specific pheromone precursor
ccg-4
. In addition, expression of a gene encoding a protein similar to zinc finger,
stc1
, was highly upregulated early in perithecial development, and a strain with a knockout of this gene exhibited arrest at the same developmental stage. A similar expression pattern was observed for genes in RNA silencing and signaling pathways, and strains with knockouts of these genes were also arrested at stages of perithecial development that paralleled their peak in expression. The observed stage specificity allowed us to correlate expression upregulation and developmental progression and to identify regulators of sexual development. Bayesian networks inferred from our expression data revealed previously known and new putative interactions between RNA silencing genes and pathways. Overall, our analysis provides a fine-scale transcriptomic landscape and novel inferences regarding the control of the multistage development process of sexual crossing and fruiting body development in
N. crassa
.
Cell Wall-Related Bionumbers and Bioestimates of Saccharomyces cerevisiae and Candida albicans
Authors: Klis Frans M. , de Koster Chris G. , Brul Stanley
Published: November 2013

Bionumbers and bioestimates are valuable tools in biological research. Here we focus on cell wall-related bionumbers and bioestimates of the budding yeast
Saccharomyces cerevisiae
and the polymorphic, pathogenic fungus
Candida albicans
. We discuss the linear relationship between cell size and cell ploidy, the correlation between cell size and specific growth rate, the effect of turgor pressure on cell size, and the reason why using fixed cells for measuring cellular dimensions can result in serious underestimation of
in vivo
values. We further consider the evidence that individual buds and hyphae grow linearly and that exponential growth of the population results from regular formation of new daughter cells and regular hyphal branching. Our calculations show that hyphal growth allows
C. albicans
to cover much larger distances per unit of time than the yeast mode of growth and that this is accompanied by strongly increased surface expansion rates. We therefore predict that the transcript levels of genes involved in wall formation increase during hyphal growth. Interestingly, wall proteins and polysaccharides seem barely, if at all, subject to turnover and replacement. A general lesson is how strongly most bionumbers and bioestimates depend on environmental conditions and genetic background, thus reemphasizing the importance of well-defined and carefully chosen culture conditions and experimental approaches. Finally, we propose that the numbers and estimates described here offer a solid starting point for similar studies of other cell compartments and other yeast species.
Identification of New Residues Involved in Intramolecular Signal Transmission in a Prokaryotic Transcriptional Repressor
Authors: Molina-Santiago Carlos , Daddaoua Abdelali , Fillet Sandy , Krell Tino , Morel Bertrand , Duque Estrella , Ramos Juan L.
Published: November 2013

TtgV is a member of the IclR family of transcriptional regulators. This regulator controls its own expression and that of the
ttgGHI
operon, which encodes an RND efflux pump. TtgV has two domains: a GAF-like domain harboring the effector-binding pocket and a helix-turn-helix (HTH) DNA-binding domain, which are linked by a long extended helix. When TtgV is bound to DNA, a kink at residue 86 in the extended helix gives rise to 2 helices. TtgV contacts DNA mainly through a canonical recognition helix, but its three-dimensional structure bound to DNA revealed that two residues, R19 and S35, outside the HTH motif, directly contact DNA. Effector binding to TtgV releases it from DNA; when this occurs, the kink at Q86 is lost and residues R19 and S35 are displaced due to the reorganization of the turn involving residues G44 and P46. Mutants of TtgV were generated at positions 19, 35, 44, 46, and 86 by site-directed mutagenesis to further analyze their role. Mutant proteins were purified to homogeneity, and differential scanning calorimetry (DSC) studies revealed that all mutants, except the Q86N mutant, unfold in a single event, suggesting conservation of the three-dimensional organization. All mutant variants bound effectors with an affinity similar to that of the parental protein. R19A, S35A, G44A, Q86N, and Q86E mutants did not bind DNA. The Q86A mutant was able to bind to DNA but was only partially released from its target operator in response to effectors. These results are discussed in the context of intramolecular signal transmission from the effector binding pocket to the DNA binding domain.
Hypersensitive Photic Responses and Intact Genome-Wide Transcriptional Control without the KaiC Phosphorylation Cycle in the Synechococcus Circadian System
Authors: Umetani Miki , Hosokawa Norimune , Kitayama Yohko , Iwasaki Hideo
Published: November 2013

Cyanobacteria are unique organisms with remarkably stable circadian oscillations. These are controlled by a network architecture that comprises two regulatory factors: posttranslational oscillation (PTO) and a transcription/translation feedback loop (TTFL). The clock proteins KaiA, KaiB, and KaiC are essential for the circadian rhythm of the unicellular species
Synechococcus elongatus
PCC 7942. Temperature-compensated autonomous cycling of KaiC phosphorylation has been proposed as the primary oscillator mechanism that maintains the circadian clock, even in the dark, and it controls genome-wide gene expression rhythms under continuous-light conditions (LL). However, the
kaiC

EE

mutation (where “EE” represents the amino acid changes Ser431Glu and Thr432Glu), where phosphorylation cycling does not occur
in vivo
, has a damped but clear
kaiBC
expression rhythm with a long period. This suggests that there must be coupling between the robust PTO and the “slave” unstable TTFL. Here, we found that the
kaiC

EE

mutant strain in LL was hypersensitive to the dark acclimation required for phase shifting. Twenty-three percent of the genes in the
kaiC

EE

mutant strain exhibited genome-wide transcriptional rhythms with a period of 48 h in LL. The circadian phase distribution was also conserved significantly in most of the wild-type and
kaiC

EE

mutant strain cycling genes, which suggests that the output mechanism was not damaged severely even in the absence of KaiC phosphorylation cycles. These results strongly suggest that the KaiC phosphorylation cycle is not essential for generating the genome-wide rhythm under light conditions, whereas it is important for appropriate circadian timing in the light and dark.
PrgK, a Multidomain Peptidoglycan Hydrolase, Is Essential for Conjugative Transfer of the Pheromone-Responsive Plasmid pCF10
Authors: Laverde Gomez Jenny A. , Bhatty Minny , Christie Peter J.
Published: November 2013

Peptidoglycan (PG) hydrolases associated with bacterial type IV secretion systems (T4SSs) are thought to generate localized lesions in the PG layer to facilitate assembly of the translocation channel. The pheromone-responsive plasmid pCF10 of
Enterococcus faecalis
encodes a putative cell wall hydrolase, PrgK, and here we report that a
prgK
deletion abolished functionality of the pCF10-encoded T4SS as monitored by pCF10 conjugative transfer. Expression in
trans
of wild-type
prgK
fully complemented this mutation. PrgK has three potential hydrolase motifs resembling staphylococcal LytM, soluble lytic transglycosylase (SLT), and cysteine-, histidine-dependent amidohydrolase/peptidase (CHAP) domains. Complementation analyses with mutant alleles established that PrgK bearing two hydrolase domains in any combination supported near-wild-type plasmid transfer, and PrgK bearing a single hydrolase domain supported at least a low level of transfer in filter matings. When exported to the
Escherichia coli
periplasm, each domain disrupted cell growth, and combinations of domains additionally induced cell rounding and blebbing and conferred enhanced sensitivity to osmotic shock. Each domain bound PG
in vitro
, but only the SLT domain exhibited detectable hydrolase activity, as shown by zymographic analyses and release of fluorescent PG fragments. Genes encoding three T4SS-associated, putative hydrolases,
Lactococcus lactis
CsiA, Tn
925
Orf14, and pIP501 TraG, partially complemented the Δ
prgK
mutation. Our findings establish that PrgK is an essential component of the pCF10-encoded Prg/Pcf T4SS and that its hydrolase domains coordinate their activities for full PrgK function. PrgK is indispensable for plasmid transfer in liquid matings, suggestive of a role in formation or stabilization of mating junctions.
Transcriptional Analysis of the Streptococcus pyogenes Salivaricin Locus
Authors: Namprachan-Frantz Phanramphoei , Rowe Hannah M. , Runft Donna L. , Neely Melody N.
Published: November 2013

The
sal
lantibiotic locus plays an important role in the virulence of
Streptococcus pyogenes
. Our transcriptional analysis of the
sal
locus provides new information on the complex regulation of this operon. Transcription of the operon is regulated by a promoter upstream of the operon and by a second internal promoter upstream of the
salKRZ
genes. Here we identify the location of the internal promoter and provide information on how this promoter is autoregulated by proteins within the locus. We determined by primer extension that the
salKR
promoter is located within the
salY
gene and identified several regulatory regions important for expression. The higher activity of the promoter in a
salKR
deletion strain indicates a role in repression by the SalR response regulator. Further, this promoter had higher activity in a
salA
deletion strain, implicating corepression or a signaling role for the SalA peptide. Finally, we demonstrate that this promoter can be controlled by host factors. Analysis of transcriptional regulation of this locus provides a better understanding of the function of the
sal
locus in
S. pyogenes
pathogenesis.
Actinobacterial Acyl Coenzyme A Synthetases Involved in Steroid Side-Chain Catabolism
Authors: Casabon Israël , Swain Kendra , Crowe Adam M. , Eltis Lindsay D. , Mohn William W.
Published: November 2013

Bacterial steroid catabolism is an important component of the global carbon cycle and has applications in drug synthesis. Pathways for this catabolism involve multiple acyl coenzyme A (CoA) synthetases, which activate alkanoate substituents for β-oxidation. The functions of these synthetases are poorly understood. We enzymatically characterized four distinct acyl-CoA synthetases from the cholate catabolic pathway of
Rhodococcus jostii
RHA1 and the cholesterol catabolic pathway of
Mycobacterium tuberculosis
. Phylogenetic analysis of 70 acyl-CoA synthetases predicted to be involved in steroid metabolism revealed that the characterized synthetases each represent an orthologous class with a distinct function in steroid side-chain degradation. The synthetases were specific for the length of alkanoate substituent. FadD19 from
M. tuberculosis
H37Rv (FadD19

Mtb

) transformed 3-oxo-4-cholesten-26-oate (
k
cat
/

K
m

= 0.33 × 10
5
± 0.03 × 10
5
M
−1
s
−1
) and represents orthologs that activate the C
8
side chain of cholesterol. Both CasG
RHA1
and FadD17

Mtb

are steroid-24-oyl-CoA synthetases. CasG and its orthologs activate the C
5
side chain of cholate, while FadD17 and its orthologs appear to activate the C
5
side chain of one or more cholesterol metabolites. CasI
RHA1
is a steroid-22-oyl-CoA synthetase, representing orthologs that activate metabolites with a C
3
side chain, which accumulate during cholate catabolism. CasI had similar apparent specificities for substrates with intact or extensively degraded steroid nuclei, exemplified by 3-oxo-23,24-bisnorchol-4-en-22-oate and 1β(2′-propanoate)-3aα-
H
-4α(3″-propanoate)-7aβ-methylhexahydro-5-indanone (
k
cat

/K
m

= 2.4 × 10
5
± 0.1 × 10
5
M
−1
s
−1
and 3.2 × 10
5
± 0.3 × 10
5
M
−1
s
−1
, respectively). Acyl-CoA synthetase classes involved in cholate catabolism were found in both
Actinobacteria
and
Proteobacteria
. Overall, this study provides insight into the physiological roles of acyl-CoA synthetases in steroid catabolism and a phylogenetic classification enabling prediction of specific functions of related enzymes.
Interaction of Apurinic/Apyrimidinic Endonucleases Nfo and ExoA with the DNA Integrity Scanning Protein DisA in the Processing of Oxidative DNA Damage during Bacillus subtilis Spore Outgrowth
Authors: Campos Silvia S. , Ibarra-Rodriguez Juan R. , Barajas-Ornelas Rocío C. , Ramírez-Guadiana Fernando H. , Obregón-Herrera Armando , Setlow Peter , Pedraza-Reyes Mario
Published: November 2013

Oxidative stress-induced damage, including 8-oxo-guanine and apurinic/apyrimidinic (AP) DNA lesions, were detected in dormant and outgrowing
Bacillus subtilis
spores lacking the AP endonucleases Nfo and ExoA. Spores of the Δ
nfo exoA
strain exhibited slightly slowed germination and greatly slowed outgrowth that drastically slowed the spores' return to vegetative growth. A null mutation in the
disA
gene, encoding a DNA integrity scanning protein (DisA), suppressed this phenotype, as spores lacking Nfo, ExoA, and DisA exhibited germination and outgrowth kinetics very similar to those of wild-type spores. Overexpression of DisA also restored the slow germination and outgrowth phenotype to
nfo exoA disA
spores. A
disA-lacZ
fusion was expressed during sporulation but not in the forespore compartment. However,
disA-lacZ
was expressed during spore germination/outgrowth, as was a DisA-green fluorescent protein (GFP) fusion protein. Fluorescence microscopy revealed that, as previously shown in sporulating cells, DisA-GFP formed discrete globular foci that colocalized with the nucleoid of germinating and outgrowing spores and remained located primarily in a single cell during early vegetative growth. Finally, the slow-outgrowth phenotype of
nfo exoA
spores was accompanied by a delay in DNA synthesis to repair AP and 8-oxo-guanine lesions, and these effects were suppressed following
disA
disruption. We postulate that a DisA-dependent checkpoint arrests DNA replication during
B. subtilis
spore outgrowth until the germinating spore's genome is free of damage.
Diagnosis of cystic fibrosis in London and South East England before and after the introduction of newborn screening
Authors: Lim MTC , Wallis C , Price J F , Carr S B , Chavasse R J , Shankar A , Seddon P , Balfour-Lynn I M
Published: November 2013

Introduction

Newborn screening (NBS) for cystic fibrosis (CF) was introduced to London and South East England in 2007. We wished to assess the details of missed cases, and to compare the age at diagnosis and other clinical parameters, prescreening and postscreening.

Methods

Retrospective and prospective case notes and database review of all newly diagnosed CF patients in our 7 CF centres, for 18 months before and 4 years after NBS started.

Results

347 patients were diagnosed with CF. 126 patients were not screened (born before or abroad), and had a median age at diagnosis of 2.4 years, excluding those with meconium ileus (MI). Their median time to diagnosis from initial symptoms was 1 year, and in 10% it was >6 years. After NBS started, 170 were diagnosed by NBS (48% were already symptomatic); 7 moved into the region after NBS elsewhere; 34 presented with MI (6 were negative on NBS); and 10 screened children were missed (false negative cases). Median age of diagnosis was 3 weeks. Prevalence was 1 in 3991 live births. By 2 years of age (with data on 104 patients), 49 children (47%) had their first isolation of Pseudomonas aeruginosa, while 37 (36%) had their first growth of Staphylococcus aureus from respiratory cultures.

Conclusions

NBS has significantly reduced the age of diagnosis, although many were symptomatic even at 3 weeks of age. A small number of patients with CF can still be missed by the screening programme, and the diagnosis should be considered even with a negative screen result.
A reliability study of colour-Doppler sonography for the diagnosis of chronic cerebrospinal venous insufficiency shows low inter-rater agreement
Authors: Leone Maurizio A , Raymkulova Olga , Lucenti Ausiliatrice , Stecco Alessandro , Bolamperti Laura , Coppo Lorenzo , Liboni William , Rivadossi Gianandrea , Zaccala Giuseppe , Maggio Maurizio , Melis Fabio , Giaccone Claudia , Carriero Alessandro , Lochner Piergiorgio
Published: November 2013

Objective

Chronic cerebrospinal venous insufficiency (CCSVI) has been extremely variable, associated with multiple sclerosis in colour-Doppler sonographic studies. We aimed to evaluate inter-rater agreement in a colour-Doppler sonography venous examination.

Design

Inter-rater agreement study.

Setting

First-referral multiple sclerosis centre.

Participants

38 patients with multiple sclerosis and 55 age-matched (±5 years) controls.

Intervention

Sonography was carried out in accordance with Zamboni’s five criteria by eight sonographers with different expertise, blinded to the status of cases and controls. Each participant was evaluated by two operators.

Primary and secondary outcome measures

Inter-rater agreement was measured through the κ statistics and the intraclass correlation coefficient.

Results

The agreement was no higher than chance for criterion 2—reflux in the deep cerebral veins (κ=−0.02) and criterion 4—flow not Doppler detectable in one or both the internal jugular veins (IJVs) or vertebral veins (VVs; −0.09). It was substantially low for criterion 1—reflux in the IJVs and/or VVs (0.29), criterion 3—IJV stenosis or malformations (0.23) and criterion 5—absence of IJV diameter increase when passing from the sitting to the supine position (0.22). The κ value for CCSVI as a whole was 0.20 (95% confidence limit −0.01 to 0.42). Intraclass correlation coefficients for the measure of cross-sectional area ranged from 0.05 to 0.25. Inter-rater agreement was low for CCSVI experts (κ=0.24; −0.11 to 0.59) and non-experts (0.20; −0.33 to 0.73); neurologists (0.21; −0.06 to 0.47) and non-neurologists (0.18; −0.20 to 0.56); cases (0.19; −0.14 to 0.52) and controls (0.21; −0.08 to 0.49). Zamboni-trained neurosonographers ascertained CCSVI more frequently than the non-trained neurosonographers.

Conclusions

Agreement was unsatisfactory for the diagnosis of CCSVI as a whole, for each of its five criteria and according to the different subgroups. Standardisation of the method is urgently needed prior to its further application in studies of patients with multiple sclerosis or other neurological diseases.
Epidemiology of time-loss injuries in English community-level rugby union
Authors: Roberts Simon P , Trewartha Grant , England Mike , Shaddick Gavin , Stokes Keith A
Published: November 2013

Objectives

Using a prospective cohort study design, to establish the incidence and nature of time-loss injuries in English community rugby and to assess the differences between different playing levels.

Setting

English community rugby clubs.

Participants

Injury information for 4635 matches was collected during seasons 2009/2010 (46 clubs), 2010/2011(67 clubs) and 2011/2012 (76 clubs). Clubs were subdivided into groups A (semiprofessional), B (amateur) and C (recreational) for analysis.

Primary and secondary outcome measures

Any injury resulting in 8 days or greater absence from match play was reported by injury management staff at the clubs. The primary outcome measure was injury incidence (per 1000 player match-hours) and the secondary outcome measure was severity (ie, days absence).

Results

Overall match injury incidence was 16.9 injuries per 1000 player match-hours. Incidence was higher for group A (21.7; 95% CI 19.8 to 23.6) compared with group B (16.6; 95% CI 15.2 to 17.9) and C (14.2; 95% CI 13.0 to 15.5, both p<0.001). The mean time-loss was 7.6 weeks absence, with knee and shoulder injuries the most severe with mean absences of 11.6 and 9.3 weeks, respectively. Half of all injuries occurred to the lower limb, with knee and ankle joint/ligament injuries the most common diagnoses. Shoulder joint/ligament injuries were the most common and severe upper limb injuries. Contact events accounted for 80% of all injuries and tackles accounted for 50%. Running was the most common non-contact injury event, of which 56% were hamstring injuries.

Conclusions

More time-loss injuries occur at higher levels of community rugby. Injury prevention strategies should focus on good technique in the tackle and conditioning exercises for the knee, ankle, hamstrings and shoulder.
MicroRNAs and liver disease: viral hepatitis, liver fibrosis and hepatocellular carcinoma
Authors: Li Gang , Cai Guohong , Li Demin , Yin Wen
Published: November 2013

MicroRNAs (miRNAs), a type of highly conserved small non-coding RNAs with an average length of 22 nucleotides, may serve as major regulators of gene expression and indispensable components of cellular gene expression networks. They have critical roles in normal biological processes and have been linked to many tumours, including hepatocellular carcinoma (HCC). HCC is the fifth most common malignancy and the third leading cause of cancer-related death worldwide. Viral hepatitis, caused by infection with hepatitis B or C viruses (HBV or HCV), can increase the risk of HCC and contributes to a significant disease burden around the world. Because of the variety of molecular alterations that may arise during the development and progression of HCC, standard of care and treatment for patients with HCC remains unsatisfactory. MiRNAs have been shown to participate in the pathogenesis of both HBV and HCV. In addition to a role in pathogenesis, miRNAs have significant clinical value in the early diagnosis of HCC since they are present in the blood and can be used as diagnostic markers and potential targets for specific systemic treatment.
Interns and their smartphones: use for clinical practice
Authors: O’Connor P , Byrne D , Butt M , Offiah G , Lydon S , Mc Inerney K , Stewart Brian , Kerin M J
Published: November 2013

Purpose of the study

Smartphone use among healthcare professionals has become widespread and will continue to grow in the coming years.

Study design

In October 2012, a survey was distributed to 230 interns at two of the national intern training networks in the Republic of Ireland, asking how they used smartphones to carry out their clinical work.

Results

It was found that out of 108 interns (47.0% response rate, 108/230), 94.4% (102/108) owned a smartphone. Of those respondents who owned a smartphone, on at least a daily basis for the purposes of work, 83.3% (85/102) made or received phone calls, 87.2% (89/102) sent or received texts, and 41.2% (42/102) sent or received emails on their smartphone. A total of 52.9% (54/102) had used their smartphone to take a work related picture. The most commonly used app was the British National Formulary. It was used daily by 30.4% (31/102) of respondents with a smartphone. The most commonly used website was Wikipedia. It was accessed at least weekly by 38.2% (39/102) of respondents with a smartphone.

Conclusions

Smartphones are used by the majority of interns on a daily basis in order to perform their job. As such, there is a need for guidance on how patient information can be safely secured and transmitted using smartphones, their appropriate use, and any restrictions on the use of these devices in certain clinical settings. For interns in particular, advice is needed on the credibility of medical apps and websites.
Temporal hemodynamic and histological progression in Sugen5416/hypoxia/normoxia-exposed pulmonary arterial hypertensive rats
Authors: Toba Michie , Alzoubi Abdallah , O'Neill Kealan D. , Gairhe Salina , Matsumoto Yuri , Oshima Kaori , Abe Kohtaro , Oka Masahiko , McMurtry Ivan F.
Published: November 2013

We have investigated the temporal relationship between the hemodynamic and histological/morphological progression in a rat model of pulmonary arterial hypertension that develops pulmonary arterial lesions morphologically indistinguishable from those in human pulmonary arterial hypertension. Adult male rats were injected with Sugen5416 and exposed to hypoxia for 3 wk followed by a return to normoxia for various additional weeks. At 1, 3, 5, 8, and 13 wk after the Sugen5416 injection, hemodynamic and histological examinations were performed. Right ventricular systolic pressure reached its maximum 5 wk after Sugen5416 injection and plateaued thereafter. Cardiac index decreased at the 3∼5-wk time point, and tended to further decline at later time points. Reflecting these changes, calculated total pulmonary resistance showed a pattern of progressive worsening. Acute intravenous fasudil markedly reduced the elevated pressure and resistance at all time points tested. The percentage of severely occluded small pulmonary arteries showed a similar pattern of progression to that of right ventricular systolic pressure. These small vessels were occluded predominantly with nonplexiform-type neointimal formation except for the 13-wk time point. There was no severe occlusion in larger arteries until the 13-wk time point, when significant numbers of vessels were occluded with plexiform-type neointima. The Sugen5416/hypoxia/normoxia-exposed rat shows a pattern of chronic hemodynamic progression similar to that observed in pulmonary arterial hypertension patients. In addition to vasoconstriction, nonplexiform-type neointimal occlusion of small arteries appears to contribute significantly to the early phase of pulmonary arterial hypertension development, and plexiform-type larger vessel occlusion may play a role in the late deterioration.
Nitric oxide suppresses vascular voltage-gated T-type Ca2+ channels through cGMP/PKG signaling
Authors: Harraz Osama F. , Brett Suzanne E. , Welsh Donald G.
Published: November 2013

Recent reports have noted that T-type Ca2+ channels (CaV3.x) are expressed in vascular smooth muscle and are potential targets of regulation. In this study, we examined whether and by what mechanism nitric oxide (NO), a key vasodilator, influences this conductance. Using patch-clamp electrophysiology and rat cerebral arterial smooth muscle cells, we monitored an inward Ba2+ current that was divisible into a nifedipine-sensitive and -insensitive component. The latter was abolished by T-type channel blocker and displayed classic T-type properties including faster activation and steady-state inactivation at hyperpolarized potentials. NO donors (sodium nitroprusside, S-nitroso- N-acetyl- dl-penicillamine), along with activators of protein kinase G (PKG) signaling, suppressed T-type currents. Inhibitors of guanylyl cyclase/PKG {1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one (ODQ) and KT5823, respectively}, had no effect on basal currents; KT5823 did, however, mask T-type Ca2+ channel current inhibition by NO/PKG. Functional experiments confirmed an inhibitory effect for NO on the T-type contribution to cerebral arterial myogenic tone. Cumulatively, our findings support the view that T-type Ca2+ channels are a regulatory target of vasodilatory signaling pathways. This targeting will influence Ca2+ dynamics and consequent tone development in the cerebral circulation.
Newborn rat response to single vs. combined cGMP-dependent pulmonary vasodilators
Authors: Enomoto Masahiro , Jain Amish , Pan Jingyi , Shifrin Yulia , Van Vliet Todd , McNamara Patrick J. , Jankov Robert P. , Belik Jaques
Published: November 2013

Inhaled nitric oxide (NO) and other cGMP- or cAMP-dependent pulmonary vasodilators are often used in combination for the treatment of the persistent pulmonary hypertension of the newborn syndrome. There is in vitro evidence to indicate that NO downregulate the pulmonary vascular response to cGMP-dependent agonists raising concern as to whether a synergistic effect is observed when employing a combined strategy in newborns. Hypothesizing that a synergistic effect is absent, we evaluated newborn and juvenile rat pulmonary arteries to determine the individual and combined vasodilatory effect of cGMP- and cAMP-dependent agonists. In precontracted near-resistance pulmonary arteries, the addition of sildenafil reduced vasorelaxation response to NO donor S-nitroso- N-acetyl penicillamine (SNAP). A similar decrease in SNAP-induced vasodilation was observed in arteries pretreated with BAY 41–2272 (10−9M), a soluble guanylate cyclase stimulator cGMP, and its downstream protein kinase activator. cGMP also reduced the vasorelaxant response to the cAMP-dependent forskolin. Inhibition of endogenous vascular NO generation enhanced SNAP-induced relaxation. The present data suggest that the mechanism involved in the cGMP desensitization to other relaxant agonists involves downregulation of the small heat shock protein HSP20 and is evident in rat pulmonary and systemic vascular smooth muscle cells. In newborn rats with chronic hypoxia-induced pulmonary hypertension, the combination of sildenafil and inhaled NO resulted in a lesser reduction in pulmonary vascular resistance compared with their individual effect. These data suggest that clinical exposure to one cGMP-dependent pulmonary vasodilator may affect the response to other cGMP- or cAMP-mediated agonists.
Phase-directed therapy: TSG-6 targeted to early inflammation improves bleomycin-injured lungs
Authors: Foskett Andrea M. , Bazhanov Nikolay , Ti XinYu , Tiblow April , Bartosh Thomas J. , Prockop Darwin J.
Published: November 2013

Previous reports demonstrated that bleomycin-induced injury of lungs in mice can be improved by the administration of murine multipotent adult stem/progenitor cells (MSCs) from the bone marrow. Recently some of the beneficial effects of MSCs have been explained by the cells being activated by signals from injured tissues to express the inflammation modulating protein TNF-α-stimulated gene/protein 6 (TSG-6). In this study, we elected to test the hypothesis that targeting the early phase of bleomycin-induced lung injury with systemic TSG-6 administration may produce therapeutic effects such as preventing the deterioration of lung function and increasing survival by modulation of the inflammatory cascade. Lung injury in C57Bl/6J mice was induced by intratracheal administration of bleomycin. Mice then received intravenous injections of TSG-6 or sham controls. Pulse oximetry was used to monitor changes in lung function. Cell infiltration was evaluated by flow cytometry, cytokine expression was measured by ELISA assays, and lungs were assessed for histological attributes. The results demonstrated that intravenous infusion of TSG-6 during the early inflammatory phase decreased cellular infiltration into alveolar spaces. Most importantly, it improved both the subsequent decrease in arterial oxygen saturation levels and the survival of the mice. These findings demonstrated that the beneficial effects of TSG-6 in a model of bleomycin-induced lung injury are largely explained by the protein modulating the early inflammatory phase. Similar phase-directed strategy with TSG-6 or other therapeutic factors that MSCs produce may be useful for other lung diseases and diseases of other organs.
Multisensor Data Fusion for Water Quality Evaluation Using Dempster-Shafer Evidence Theory
Authors: Zhou Jian , Liu Linfeng , Guo Jian , Sun Lijuan
Published: November 2013

A multisensor data fusion approach for water quality evaluation using Dempster-Shafer evidence theory is presented. To evaluate water quality, each sensor measurement is considered as a piece of evidence. Based on the water quality parameters measured by sensor node, the mass function of water quality class is calculated. Evidence from each sensor is given a reliability discounting and then combined with the others by D-S rule. According to the decision rule which uses the fusion mass function values, the class of water quality can be determined. Finally, experiments are given to demonstrate that the proposed approach can evaluate water quality from uncertain sensor data and improve evaluation performance.
Improved Methane Sensing Properties of Co‐Doped SnO2 Electrospun Nanofibers
Authors: Chen Weigen , Zhou Qu , Xu Lingna , Wan Fu , Peng Shudi , Zeng Wen
Published: November 2013

Co‐doped SnO2 nanofibers were successfully synthesized via electrospinning method, and Co‐doped SnO2 nanospheres were also prepared with traditional hydrothermal synthesis route for comparison. The synthesized SnO2 nanostructures were characterized by X‐ray powder diffraction, scanning electron microscopy, transmission electron microscopy, energy dispersive X‐ray spectroscopy, and X‐ray photoelectron spectra. Planar‐type chemical gas sensors were fabricated and their sensing properties to methane were investigated in detail. Gas sensors based on these two samples demonstrate the highest CH4 sensing response at an operating temperature of 300°C. Compared with traditional SnO2 nanospheres, the nanofiber sensor shows obviously enhanced gas response, higher saturated detection concentration, and quicker response‐recovery time to methane. Moreover, good stability, prominent reproducibility, and excellent selectivity are also observed based on the nanofibers. These results demonstrate the potential application of Co‐doped SnO2 nanofibers for fabricating high performance methane sensors.
A Robust Variable Sampling Time BLDC Motor Control Design Based upon μ‐Synthesis
Authors: Hung Chung-Wen , Yen Jia-Yush
Published: November 2013

The variable sampling rate system is encountered in many applications. When the speed information is derived from the position marks along the trajectory, one would have a speed dependent sampling rate system. The conventional fixed or multisampling rate system theory may not work in these cases because the system dynamics include the uncertainties which resulted from the variable sampling rate. This paper derived a convenient expression for the speed dependent sampling rate system. The varying sampling rate effect is then translated into multiplicative uncertainties to the system. The design then uses the popular μ‐synthesis process to achieve a robust performance controller design. The implementation on a BLDC motor demonstrates the effectiveness of the design approach.
The Generation, Analysis, and Circuit Implementation of a New Memristor Based Chaotic System
Authors: Li Yuxia , Huang Xia , Guo Mei
Published: November 2013

We present a new memristor based chaotic circuit, which is generated by replacing the nonlinear resistor in Chua’s circuit with a flux-controlled memristor and a negative conductance. The dynamical behaviors are verified not only by computer simulations but also by Lyapunov exponents, bifurcation analysis, Poincaré mapping, power spectrum analysis, and laboratory experiments.
Lignin: Characterization of a Multifaceted Crop Component
Authors: Frei Michael
Published: November 2013

Lignin is a plant component with important implications for various agricultural disciplines. It confers rigidity to cell walls, and is therefore associated with tolerance to abiotic and biotic stresses and the mechanical stability of plants. In animal nutrition, lignin is considered an antinutritive component of forages as it cannot be readily fermented by rumen microbes. In terms of energy yield from biomass, the role of lignin depends on the conversion process. It contains more gross energy than other cell wall components and therefore confers enhanced heat value in thermochemical processes such as direct combustion. Conversely, it negatively affects biological energy conversion processes such as bioethanol or biogas production, as it inhibits microbial fermentation of the cell wall. Lignin from crop residues plays an important role in the soil organic carbon cycling, as it constitutes a recalcitrant carbon pool affecting nutrient mineralization and carbon sequestration. Due to the significance of lignin in several agricultural disciplines, the modification of lignin content and composition by breeding is becoming increasingly important. Both mapping of quantitative trait loci and transgenic approaches have been adopted to modify lignin in crops. However, breeding goals must be defined considering the conflicting role of lignin in different agricultural disciplines.
Analysis of Pd‐Ni Nanobelts Melting Process Using Molecular Dynamics Simulation
Authors: Gang Chen , Peng Zhang , HongWei Liu
Published: November 2013

The melting process of Pd‐Ni alloy nanobelts with different Ni atom content has been simulated by molecular dynamic (MD) method. The radial distribution function, the Lindemann index, and pair analysis method were used to characterize Pd‐Ni nanobelt models in simulation. The results indicate that the melting temperature of Pd‐Ni nanobelt with composition far from pure metal was lower than that of other models, and the breaking point of the nanobelt can be illustrated by the Lindemann index. Pair analysis indicates that the number of FCC pairs will decrease and almost disappear at melting point with increasing temperature. The melting points of Pd‐Ni alloy nanobelts were also calculated by thermodynamic method, and the results were close to that obtained by MD simulation.
Bulk Synthesis and Characterization of Ti3Al Nanoparticles by Flow‐Levitation Method
Authors: Chen Shanjun , Chen Yan , Zhang Huafeng , Tang Yongjian , Wei Jianjun , Sun Weiguo
Published: November 2013

A novel bulk synthesis method for preparing high pure Ti3Al nanoparticles was developed by flow‐levitation method (FL). The Ti and Al vapours ascending from the high temperature levitated droplet were condensed by cryogenic Ar gas under atmospheric pressure. The morphology, crystalline structure, and chemical composition of Ti3Al nanoparticles were, respectively, investigated by transmission electron microscopy, X‐ray diffraction, and inductively coupled plasma atomic emission spectrometry. The results indicated that the Ti3Al powders are nearly spherical‐shaped, and the particle size ranges from several nanometers to 100 nm in diameter. Measurements of the d‐spacing from X‐ray (XRD) and electron diffraction studies confirmed that the Ti3Al nanoparticles have a hexagonal structure. A thin oxidation coating of 2‐3 nm in thickness was formed around the particles after exposure to air. Based on the XPS measurements, the surface coating of the Ti3Al nanoparticles is a mixture of Al2O3 and TiO2. The production rate of Ti3Al nanoparticles was estimated to be about 3 g/h. This method has a great potential in mass production of Ti3Al nanoparticles.
Molecular Mechanisms of Treadmill Therapy on Neuromuscular Atrophy Induced via Botulinum Toxin A
Authors: Tsai Sen-Wei , Chen Hsiao-Ling , Chang Yi-Chun , Chen Chuan-Mu
Published: November 2013

Botulinum toxin A (BoNT-A) is a bacterial zinc-dependent endopeptidase that acts specifically on neuromuscular junctions. BoNT-A blocks the release of acetylcholine, thereby decreasing the ability of a spastic muscle to generate forceful contraction, which results in a temporal local weakness and the atrophy of targeted muscles. BoNT-A-induced temporal muscle weakness has been used to manage skeletal muscle spasticity, such as poststroke spasticity, cerebral palsy, and cervical dystonia. However, the combined effect of treadmill exercise and BoNT-A treatment is not well understood. We previously demonstrated that for rats, following BoNT-A injection in the gastrocnemius muscle, treadmill running improved the recovery of the sciatic functional index (SFI), muscle contraction strength, and compound muscle action potential (CMAP) amplitude and area. Treadmill training had no influence on gastrocnemius mass that received BoNT-A injection, but it improved the maximal contraction force of the gastrocnemius, and upregulation of GAP-43, IGF-1, Myo-D, Myf-5, myogenin, and acetylcholine receptor (AChR) subunitsαandβwas found following treadmill training. Taken together, these results suggest that the upregulation of genes associated with neurite and AChR regeneration following treadmill training may contribute to enhanced gastrocnemius strength recovery following BoNT-A injection.