bluuebunny/crossref_metadata_2025_split huggingface dataset:
Computer‐assisted quantitative upper airway analysis following modified uvulopalatal flap and lateral pharyngoplasty for obstructive sleep apnoea: a prospective case‐controlled study
Authors: Hsu P.P. , Tan A.K.L. , Gan E.C. , Chan Y.H. , Goh M.M. , Lu P.K.S. , Howe W.L. 
Published: May 2012

Clin. Otolaryngol. 2012, 37, 188–196Objectives:  The study aims to perform static and dynamic quantitative assessment of the anatomical changes of the upper airway before and after modified uvulopalatal flap and lateral pharyngoplasty and comparison of the improvement in airway dimensions, collapsibility and extent of normalisation to that of control patients.Design:  Prospective case‐controlled study.Setting:  Computer‐assisted quantitative measurement is used to compare upper airway parameters before and after modified uvulopalatal flap and lateral pharyngoplasty in patients with obstructive sleep apnoea (OSA).Participants:  Patients with obstructive sleep apnoea diagnosed on sleep study and failed positive airway pressure therapy.Main outcome measures:  Sleep study results, upper airway parameters and symptom score following surgery and its comparison to normal patients to assess the degree and extent of normalisation.Results:  Thirty‐five study and 32 control subjects were recruited and completed the study. All the retropalatal airway dimensions like area, transverse diameter, longitudinal diameter and collapsibility showed statistically significant improvement following surgery. The success rate of this surgery is 43% (15 of 35) overall, 58% (14 of 24) for patients with isolated palatal obstruction and only 9% (1 of 11) for patients with multi‐level obstruction. Comparing obstructive sleep apnoea to the control subjects, there are obvious and logical differences in their biostatistics, sleep study parameters and airway dimensions. The postoperative obstructive sleep apnoea retropalatal longitudinal diameter has a higher tendency of normalising to be comparable to those of control patients.Conclusions:  Modified uvulopalatal flap and lateral pharyngoplasty is an effective surgical technique for the treatment of obstructive sleep apnoea. The surgery increases the resting retropalatal dimensions and reduces the retropalatal collapsibility.
Inhibition of sarcoplasmic reticulum Ca2+‐ATPase decreases atrioventricular node‐paced heart rate in rabbits
Authors: Cheng Hongwei , Smith Godfrey L. , Orchard Clive H. , Hancox Jules C. , Burton Francis L. 
Published: May 2012

Recent data indicate that Ca2+ cycling in isolated atrioventricular node (AVN) cells contributes to setting spontaneous rate. The aim of the present study was to extend this observation to the intact AVN in situ, by evaluating the effects of inhibiting sarcoplasmic reticulum Ca2+ uptake with cyclopiazonic acid (CPA) on intact AVN spontaneous activity and its response to isoprenaline. A model of the AVN‐paced heart was produced to investigate intact AVN automaticity, by surgical ablation of the sino‐atrial node (SAN) in the rabbit Langendorff‐perfused heart. Electrograms were recorded from a site close to the AVN (triangle of Koch), an atrial site above the AVN, the left atrium and right ventricle, enabling AVN pacing of the preparation to be confirmed. Before SAN ablation, the heart rate was 166.8 ± 5.4 beats min−1. Ablation of the SAN was clearly indicated by a sudden and significant decrease of heart rate to 108.6 ± 9.6 beats min−1 (P < 0.01, n = 10). Isoprenaline (100 nm) increased AVN rate to 187.8 ± 12.0 beats min−1 after 1 min of application (P < 0.01, n = 10). Cyclopiazonic acid (10 and 30 μm) decreased AVN rate to 81.6 ± 4.8 (n = 9) and 77.4 ± 6.0 beats min−1 (n = 7), respectively [P < 0.05, 10 or 30 μm CPA versus control (n = 10)] and also reduced the AVN rate increase in response to isoprenaline from 78.8 ± 10.0 to 46.8 ± 6.8 and 26.7 ± 5.3%, respectively (P < 0.01). These inhibitory effects of CPA on the intact AVN rate and its response to isoprenaline indicate that Ca2+ cycling is important to the intact AVN spontaneous activity and its acceleration during sympathetic stimulation.
Catabolite Repression Control of Pyocyanin Biosynthesis at an Intersection of Primary and Secondary Metabolism in Pseudomonas aeruginosa
Authors: Huang Jiaofang , Sonnleitner Elisabeth , Ren Bin , Xu Yuquan , Haas Dieter 
Published: May 2012

ABSTRACT

In
Pseudomonas aeruginosa
, the catabolite repression control (Crc) protein repressed the formation of the blue pigment pyocyanin in response to a preferred carbon source (succinate) by interacting with
phzM
mRNA, which encodes a key enzyme in pyocyanin biosynthesis. Crc bound to an extended imperfect recognition sequence that was interrupted by the AUG translation initiation codon.
Screening for a Single-Chain Variable-Fragment Antibody That Can Effectively Neutralize the Cytotoxicity of the Vibrio parahaemolyticus Thermolabile Hemolysin
Authors: Wang Rongzhi , Fang Sui , Wu Dinglong , Lian Junwei , Fan Jue , Zhang Yanfeng , Wang Shihua , Lin Wenxiong 
Published: May 2012

ABSTRACT

Vibrio parahaemolyticus
is a halophilic bacterium that is widely distributed in water resources. The bacterium causes lethal food-borne diseases and poses a serious threat to human and animal health all over the world. The major pathogenic factor of
V. parahaemolyticus
is thermolabile hemolysin (TLH), encoded by the
tlh
gene, but its toxicity mechanisms are unknown. A high-affinity antibody that can neutralize TLH activity effectively is not available. In this study, we successfully expressed and purified the TLH antigen and discovered a high-affinity antibody to TLH, named scFv-LA3, by phage display screening. Cytotoxicity analysis showed that scFv-LA3 has strong neutralization effects on TLH-induced cell toxicity.
Influence of Exposure Time on Gene Expression by Human Intestinal Epithelial Cells Exposed to Lactobacillus acidophilus
Authors: O'Flaherty Sarah , Klaenhammer Todd R. 
Published: May 2012

ABSTRACT

Analysis of global temporal gene expression by human intestinal cells when exposed to
Lactobacillus acidophilus
revealed induction of immune-related pathways and NF-κB target genes after a 1-h exposure, compared to a 4- or 8-h exposure. Additionally, an
L. acidophilus
derivative expressing covalently bound flagellin resulted in increased induction of
il8
,
cxc1
, and
cxcl2
compared to the parent
L. acidophilus
.
Effects of Nitrogen Dioxide and Anoxia on Global Gene and Protein Expression in Long-Term Continuous Cultures of Nitrosomonas eutropha C91
Authors: Kartal Boran , Wessels Hans J. C. T. , van der Biezen Erwin , Francoijs Kees-Jan , Jetten Mike S. M. , Klotz Martin G. , Stein Lisa Y. 
Published: May 2012

ABSTRACTNitrosomonas eutrophais an ammonia-oxidizing betaproteobacterium found in environments with high ammonium levels, such as wastewater treatment plants. The effects of NO2on gene and protein expression under oxic and anoxic conditions were determined by maintainingN. eutrophastrain C91 in a chemostat fed with ammonium under oxic, oxic-plus-NO2, and anoxic-plus-NO2culture conditions. Cells remained viable but ceased growing under anoxia; hence, the chemostat was switched from continuous to batch cultivation to retain biomass. After several weeks under each condition, biomass was harvested for total mRNA and protein isolation. Exposure ofN. eutrophaC91 to NO2under either oxic or anoxic conditions led to a decrease in proteins involved in N and C assimilation and storage and an increase in proteins involved in energy conservation, including ammonia monooxygenase (AmoCAB). Exposure to anoxia plus NO2resulted in increased representation of proteins and transcripts reflective of an energy-deprived state. Several proteins implicated in N-oxide metabolism were expressed and remained unchanged throughout the experiment, except for NorCB nitric oxide reductase, which was not detected in the proteome. Rather, NorY nitric oxide reductase was expressed under oxic-plus-NO2and anoxic-plus-NO2conditions. The results indicate that exposure to NO2results in an energy-deprived state ofN. eutrophaC91 and that anaerobic growth could not be supported with NO2as an oxidant.
Chitin-Like Molecules Associate with Cryptococcus neoformans Glucuronoxylomannan To Form a Glycan Complex with Previously Unknown Properties
Authors: Ramos Caroline L. , Fonseca Fernanda L. , Rodrigues Jessica , Guimarães Allan J. , Cinelli Leonardo P. , Miranda Kildare , Nimrichter Leonardo , Casadevall Arturo , Travassos Luiz R. , Rodrigues Marcio L. 
Published: May 2012

ABSTRACT

In prior studies, we demonstrated that glucuronoxylomannan (GXM), the major capsular polysaccharide of the fungal pathogen
Cryptococcus neoformans
, interacts with chitin oligomers at the cell wall-capsule interface. The structural determinants regulating these carbohydrate-carbohydrate interactions, as well as the functions of these structures, have remained unknown. In this study, we demonstrate that glycan complexes composed of chitooligomers and GXM are formed during fungal growth and macrophage infection by
C. neoformans
. To investigate the required determinants for the assembly of chitin-GXM complexes, we developed a quantitative scanning electron microscopy-based method using different polysaccharide samples as inhibitors of the interaction of chitin with GXM. This assay revealed that chitin-GXM association involves noncovalent bonds and large GXM fibers and depends on the
N
-acetyl amino group of chitin. Carboxyl and
O
-acetyl groups of GXM are not required for polysaccharide-polysaccharide interactions. Glycan complex structures composed of cryptococcal GXM and chitin-derived oligomers were tested for their ability to induce pulmonary cytokines in mice. They were significantly more efficient than either GXM or chitin oligomers alone in inducing the production of lung interleukin 10 (IL-10), IL-17, and tumor necrosis factor alpha (TNF-α). These results indicate that association of chitin-derived structures with GXM through their
N
-acetyl amino groups generates glycan complexes with previously unknown properties.
Editosome Accessory Factors KREPB9 and KREPB10 in Trypanosoma brucei
Authors: Lerch Melissa , Carnes Jason , Acestor Nathalie , Guo Xuemin , Schnaufer Achim , Stuart Kenneth 
Published: May 2012

ABSTRACT

Multiprotein complexes, called editosomes, catalyze the uridine insertion and deletion RNA editing that forms translatable mitochondrial mRNAs in kinetoplastid parasites. We have identified here two new U1-like zinc finger proteins that associate with editosomes and have shown that they are related to KREPB6, KREPB7, and KREPB8, and thus we have named them
K
inetoplastid
R
NA
E
diting
P
roteins, KREPB9 and KREPB10. They are conserved and syntenic in trypanosomatids although KREPB10 is absent in
Trypanosoma vivax
and both are absent in
Leishmania
. Tandem affinity purification (TAP)-tagged KREPB9 and KREPB10 incorporate into ∼20S editosomes and/or subcomplexes thereof and preferentially associate with deletion subcomplexes, as do KREPB6, KREPB7, and KREPB8. KREPB10 also associates with editosomes that are isolated via a chimeric endonuclease, KREN1 in KREPB8 RNA interference (RNAi) cells, or MEAT1. The purified complexes have precleaved editing activities and endonuclease cleavage activity that appears to leave a 5′ OH on the 3′ product. RNAi knockdowns did not affect growth but resulted in relative reductions of both edited and unedited mitochondrial mRNAs. The similarity of KREPB9 and KREPB10 to KREPB6, KREPB7, and KREPB8 suggests they may be accessory factors that affect editing endonuclease activity and as a consequence may affect mitochondrial mRNA stability. KREPB9 and KREPB10, along with KREPB6, KREPB7, and KREPB8, may enable the endonucleases to discriminate among and accurately cleave hundreds of different editing sites and may be involved in the control of differential editing during the life cycle of
T. brucei
.
Export Requirements of Pneumolysin in Streptococcus pneumoniae
Authors: Price Katherine E. , Greene Neil G. , Camilli Andrew 
Published: May 2012

ABSTRACT

Streptococcus pneumoniae
is a major causative agent of otitis media, pneumonia, bacteremia, and meningitis. Pneumolysin (Ply), a member of the cholesterol-dependent cytolysins (CDCs), is produced by virtually all clinical isolates of
S. pneumoniae
, and
ply
mutant strains are severely attenuated in mouse models of colonization and infection. In contrast to all other known members of the CDC family, Ply lacks a signal peptide for export outside the cell. Instead, Ply has been hypothesized to be released upon autolysis or, alternatively, via a nonautolytic mechanism that remains undefined. We show that an exogenously added signal sequence is not sufficient for Sec-dependent Ply secretion in
S. pneumoniae
but is sufficient in the surrogate host
Bacillus subtilis
. Previously, we showed that Ply is localized primarily to the cell wall compartment in the absence of detectable cell lysis. Here we show that Ply released by autolysis cannot reassociate with intact cells, suggesting that there is a Ply export mechanism that is coupled to cell wall localization of the protein. This putative export mechanism is capable of secreting a related CDC without its signal sequence. We show that
B. subtilis
can export Ply, suggesting that the export pathway is conserved. Finally, through truncation and domain swapping analyses, we show that export is dependent on domain 2 of Ply.
Substrate Specificity of the Citrate Transporter CitP of Lactococcus lactis
Authors: Pudlik Agata M. , Lolkema Juke S. 
Published: May 2012

ABSTRACT

The citrate transporter CitP of lactic acid bacteria catalyzes electrogenic precursor-product exchange of citrate versus
l
-lactate during citrate-glucose cometabolism. In the absence of sugar,
l
-lactate is replaced by the metabolic intermediates/end products pyruvate, α-acetolactate, and acetate. In this study, the binding and translocation properties of CitP were analyzed systematically for a wide variety of mono- and dicarboxylates of the form X-CR
2
-COO
−
, where X represents OH (2-hydroxy acid), O (2-keto acid), or H (acid) and R groups differ in size, hydrophobicity, and composition. It follows that CitP is a very promiscuous carboxylate transporter. A carboxylate group is both essential and sufficient for recognition by the transporter. A C-2 atom is not essential, formate is a substrate, and C-2 may be part of a ring structure, as in benzoate. The R group may be as bulky as an indole ring structure. For all monocarboxylates of the form X-CHR-COO
−
, the hydroxy (X = OH) analogs were the preferred substrates. The preference for keto (X = O) or acid (X = H) analogs was dependent on the bulkiness of the R group, such that the acid was preferred for small R groups and the 2-ketoacid was preferred for more bulky R groups. The C
4
to C
6
dicarboxylates succinate, glutarate, and adipate were also substrates of CitP. The broad substrate specificity is discussed in the context of a model of the binding site of CitP. Many of the substrates of CitP are intermediates or products of amino acid metabolism, suggesting that CitP may have a broader physiological function than its role in citrate fermentation alone.
Error-Prone PCR Mutagenesis Reveals Functional Domains of a Bacterial Transcriptional Activator, TraJ
Authors: Lu Jun , Peng Yun , Arutyunov Denis , Frost Laura S. , Glover J. N. Mark 
Published: May 2012

ABSTRACT

TraJ is the essential activator of P
Y
, the promoter of the F and F-like plasmid
tra
operon that encodes the majority of the proteins for bacterial conjugation. By combining error-prone PCR mutagenesis with a two-plasmid screen, we isolated 55 missense mutations in
traJ
, each affecting the ability of TraJ to activate P
Y
. These mutations define two distinct functional clusters (amino acids [aa] 21 to 117 and aa 150 to 219). Limited proteolytic analysis of TraJ suggested that the N- and C-terminal functional clusters are two structurally distinct domains. Most TraJ mutants exhibited decreased intracellular protein levels, and the HslVU protease-chaperone pair was found to be responsible for degrading those mutants without extracytoplasmic stress-induced overexpression.
In vivo
cross-linking analysis of TraJ mutants indicated that the N-terminal domain is responsible for dimerization. This was confirmed by the finding that the purified N-terminal region of TraJ forms dimers in solution. The levels of dimerization and
in vivo
activities of TraJ mutants are well correlated, suggesting that dimerization of TraJ is required for its biological function. We propose that the regulation of TraJ dimerization and/or its susceptibility to HslVU could be a key mechanism in various signaling processes for controlling bacterial conjugation in response to physiological or environmental stimuli.
Novel Miniature Transposable Elements in Thermophilic Synechococcus Strains and Their Impact on an Environmental Population
Authors: Nelson William C. , Bhaya Devaki , Heidelberg John F. 
Published: May 2012

ABSTRACT

The genomes of the two closely related freshwater thermophilic cyanobacteria
Synechococcus
sp. strain JA-3-3Ab and
Synechococcus
sp. strain JA-2-3B′a(2-13) each host several families of insertion sequences (ISSoc families) at various copy numbers, resulting in an overall high abundance of insertion sequences in the genomes. In addition to full-length copies, a large number of internal deletion variants have been identified. ISSoc2 has two variants (ISSoc2∂-1 and ISSoc2∂-2) that are observed to have multiple near-exact copies. Comparison of environmental metagenomic sequences to the
Synechococcus
genomes reveals novel placement of copies of ISSoc2, ISSoc2∂-1, and ISSoc2∂-2. Thus, ISSoc2∂-1 and ISSoc2∂-2 appear to be active nonautonomous mobile elements derived by internal deletion from ISSoc2. Insertion sites interrupting genes that are likely critical for cell viability were detected; however, most insertions either were intergenic or were within genes of unknown function. Most novel insertions detected in the metagenome were rare, suggesting a stringent selective environment. Evidence for mobility of internal deletion variants of other insertion sequences in these isolates suggests that this is a general mechanism for the formation of miniature insertion sequences.
Implication of Proteins Containing Tetratricopeptide Repeats in Conditional Virulence Phenotypes of Legionella pneumophila
Authors: Bandyopadhyay Purnima , Sumer Eren U. , Jayakumar Deepak , Liu Shuqing , Xiao Huifang , Steinman Howard M. 
Published: May 2012

ABSTRACT

Legionella pneumophila
, the causative agent of Legionnaires' disease, is a ubiquitous freshwater bacterium whose virulence phenotypes require a type IV secretion system (T4SS).
L. pneumophila
strain JR32 contains two virulence-associated T4SSs, the Dot/Icm and Lvh T4SSs. Defective entry and phagosome acidification phenotypes of
dot
/
icm
mutants are conditional and reversed by incubating broth-grown stationary-phase cultures in water (WS treatment) prior to infection, as a mimic of the aquatic environment of
Legionella
. Reversal of
dot
/
icm
virulence defects requires the Lvh T4SS and is associated with a >10-fold induction of LpnE, a tetratricopeptide repeat (TPR)-containing protein. In the current study, we demonstrated that defective entry and phagosome acidification phenotypes of mutants with changes in LpnE and EnhC, another TPR-containing protein, were similarly reversed by WS treatment. In contrast to
dot
/
icm
mutants for which the Lvh T4SS was required, reversal for the Δ
lpnE
or the Δ
enhC
mutant required that the other TPR-containing protein be present. The single and double Δ
lpnE
and Δ
enhC
mutants showed a hypersensitivity to sodium ion, a phenotype associated with dysfunction of the Dot/Icm T4SS. The Δ
lpnE
single and the Δ
lpnE
Δ
enhC
double mutant showed 3- to 9-fold increases in translocation of Dot/Icm T4SS substrates, LegS2/SplY and LepB. Taken together, these data identify TPR-containing proteins in a second mechanism by which the WS mimic of a
Legionella
environmental niche can reverse virulence defects of broth-grown cultures and implicate LpnE and EnhC directly or indirectly in translocation of Dot/Icm T4SS protein substrates.
Defective Lipoprotein Sorting Induces
lolA
Expression through the Rcs Stress Response Phosphorelay System
Authors: Tao Kazuyuki , Narita Shin-ichiro , Tokuda Hajime 
Published: May 2012

ABSTRACT

The
Escherichia coli
LolA protein is a lipoprotein-specific chaperone that carries lipoproteins from the inner to the outer membrane. A dominant negative LolA mutant, LolA(I93C/F140C), in which both
93
Ile and
140
Phe are replaced by Cys, binds tightly to the lipoprotein-dedicated ABC transporter LolCDE complex on the inner membrane and therefore inhibits the detachment of outer membrane-specific lipoproteins from the inner membrane. We found that the expression of this mutant strongly induced
lolA
gene transcription. The depletion of the LolA or LolB protein also triggered
lolA
gene transcription, indicating that the inhibition of outer membrane lipoprotein transport triggers
lolA
transcription. To elucidate the mechanism, we isolated mutants that are unable to induce
lolA
transcription using the
lacZ
gene fused to the
lolA
promoter as a reporter and found that the Rcs phosphorelay system directly regulates
lolA
transcription. An outer membrane lipoprotein, RcsF, was essential for this activation, while the coactivator RcsA was dispensable. Taking the observation that an RcsF mutant localized in the inner membrane constitutively activated the Rcs phosphorelay system into consideration, the results shown here strongly suggest that correct lipoprotein sorting to the outer membrane is monitored by RcsF, which plays a key role in the Rcs stress response system.
A pragmatic randomised controlled trial in primary care of the Camden Weight Loss (CAMWEL) programme
Authors: Nanchahal Kiran , Power Tom , Holdsworth Elizabeth , Hession Michelle , Sorhaindo Annik , Griffiths Ulla , Townsend Joy , Thorogood Nicki , Haslam David , Kessel Anthony , Ebrahim Shah , Kenward Mike , Haines Andrew 
Published: May 2012

ObjectivesTo evaluate effectiveness of a structured one-to-one behaviour change programme on weight loss in obese and overweight individuals.DesignRandomised controlled trial.Setting23 general practices in Camden, London.Participants381 adults with body mass index ≥25 kg/m2randomly assigned to intervention (n=191) or control (n=190) group.InterventionsA structured one-to-one programme, delivered over 14 visits during 12 months by trained advisors in three primary care centres compared with usual care in general practice.Outcome measuresChanges in weight, per cent body fat, waist circumference, blood pressure and heart rate between baseline and 12 months.Results217/381 (57.0%) participants were assessed at 12 months: missing values were imputed. The difference in mean weight change between the intervention and control groups was not statistically significant (0.70 kg (0.67 to 2.17, p=0.35)), although a higher proportion of the intervention group (32.7%) than the control group (20.4%) lost 5% or more of their baseline weight (OR: 1.80 (1.02 to 3.18, p=0.04)). The intervention group achieved a lower mean heart rate (mean difference 3.68 beats per minute (0.31 to 7.04, p=0.03)) than the control group. Participants in the intervention group reported higher satisfaction and more positive experiences of their care compared with the control group.ConclusionsAlthough there is no significant difference in mean weight loss between the intervention and control groups, trained non-specialist advisors can deliver a structured programme and achieve clinically beneficial weight loss in some patients in primary care. The intervention group also reported a higher level of satisfaction with the support received. Primary care interventions are unlikely to be sufficient to tackle the obesity epidemic and effective population-wide measures are also necessary.Clinical trial registration numberTrial registrationClincaltrials.govNCT00891943.