bluuebunny/crossref_metadata_2025_split huggingface dataset:
Identification of the
cglC
,
cglD
,
cglE
, and
cglF
Genes and Their Role in Cell Contact-Dependent Gliding Motility in Myxococcus xanthus
Authors: Pathak Darshankumar T. , Wall Daniel 
Published: February 2012

ABSTRACT

Within
Myxococcus xanthus
biofilms, cells actively move and exchange their outer membrane (OM) lipoproteins and lipids. Between genetically distinct strains, OM exchange can regulate recipient cell behaviors, including gliding motility and development. Although many different proteins are thought to be exchanged, to date, only two endogenous OM lipoproteins, CglB and Tgl, are known to be transferred. Protein exchange requires the TraAB proteins in recipient and donor cells, where they are hypothesized to facilitate OM fusion for transfer. To better understand the types of proteins exchanged, we identified the genes for the remaining set of
cgl
gliding motility mutants. These mutants are unique because their motility defect can be transiently restored by physical contact with donor cells that encode the corresponding wild-type protein, a process called stimulation. Similar to CglB and Tgl, the
cglC
and
cglD
genes encode type II signal sequences, suggesting that they are also lipoproteins. Surprisingly, the
cglE
and
cglF
genes instead encode type I signal sequences, suggesting that nonlipoproteins are also exchanged. Consistent with this idea, the addition of exogenous synthetic CglF protein (71 amino acids) to a
cglF
mutant rescued its motility defect. In contrast to a live donor cell, stimulation with purified CglF protein occurred independently of TraA. These results also indicate that CglF may localize to the cell surface. The implications of our findings on OM exchange are discussed.
Novel Colicin F
Y
of Yersinia frederiksenii Inhibits Pathogenic Yersinia Strains via YiuR-Mediated Reception, TonB Import, and Cell Membrane Pore Formation
Authors: Bosák Juraj , Laiblová Petra , Šmarda Jan , Dědičová Daniela , Šmajs David 
Published: February 2012

ABSTRACT

A novel colicin type, designated colicin F
Y
, was found to be encoded and produced by the strain
Yersinia frederiksenii
Y27601. Colicin F
Y
was active against both pathogenic and nonpathogenic strains of the genus
Yersinia
. Plasmid YF27601 (5,574 bp) of
Y. frederiksenii
Y27601 was completely sequenced. The colicin F
Y
activity gene (
cfyA
) and the colicin F
Y
immunity gene (
cfyI
) were identified. The deduced amino acid sequence of colicin F
Y
was very similar in its C-terminal pore-forming domain to colicin Ib (69% identity in the last 178 amino acid residues), indicating pore forming as its lethal mode of action. Transposon mutagenesis of the colicin F
Y
-susceptible strain
Yersinia kristensenii
Y276 revealed the
yiuR
gene (ykris001_4440), which encodes the YiuR outer membrane protein with unknown function, as the colicin F
Y
receptor molecule. Introduction of the
yiuR
gene into the colicin F
Y
-resistant strain
Y. kristensenii
Y104 restored its susceptibility to colicin F
Y
. In contrast, the colicin F
Y
-resistant strain
Escherichia coli
TOP10F′ acquired susceptibility to colicin F
Y
only when both the
yiuR
and
tonB
genes from
Y. kristensenii
Y276 were introduced. Similarities between colicins F
Y
and Ib, similarities between the Cir and YiuR receptors, and the detected partial cross-immunity of colicin F
Y
and colicin Ib producers suggest a common evolutionary origin of the colicin F
Y
-YiuR and colicin Ib-Cir systems.
Characterization of Campylobacter jejuni RacRS Reveals Roles in the Heat Shock Response, Motility, and Maintenance of Cell Length Homogeneity
Authors: Apel Dmitry , Ellermeier Jeremy , Pryjma Mark , DiRita Victor J. , Gaynor Erin C. 
Published: February 2012

ABSTRACT

Campylobacter jejuni
commensally colonizes the cecum of birds. The RacR (
r
educed
a
bility to
c
olonize) response
r
egulator was previously shown to be important in avian colonization. To explore the means by which RacR and its cognate sensor kinase RacS may modulate
C. jejuni
physiology and colonization, Δ
racR
and Δ
racS
mutations were constructed in the invasive, virulent strain 81-176, and extensive phenotypic analyses were undertaken. Both the Δ
racR
and Δ
racS
mutants exhibited a ∼100-fold defect in chick colonization despite no (Δ
racS
) or minimal (Δ
racR
) growth defects at 42°C, the avian body temperature. Each mutant was defective for colony formation at 44°C and in the presence of 0.8% NaCl, both of which are stresses associated with the heat shock response. Promoter-reporter and real-time quantitative PCR (RT-qPCR) analyses revealed that RacR activates
racRS
and represses
dnaJ
. Although disregulation of several other heat shock genes was not observed at 38°C, the Δ
racR
and Δ
racS
mutants exhibited diminished upregulation of these genes upon a rapid temperature upshift. Furthermore, the Δ
racR
and Δ
racS
mutants displayed increased length heterogeneity during exponential growth, with a high proportion of filamented bacteria. Filamented bacteria had reduced swimming speed and were defective for invasion of Caco-2 epithelial cells. Soft-agar studies also revealed that the loss of
racR
or
racS
resulted in whole-population motility defects in viscous medium. These findings reveal new roles for RacRS in
C. jejuni
physiology, each of which is likely important during colonization of the avian host.
Transcriptional Regulation of the
assT
-
dsbL
-
dsbI
Gene Cluster in Salmonella enterica Serovar Typhi IMSS-1 Depends on LeuO, H-NS, and Specific Growth Conditions
Authors: Gallego-Hernández A. L. , Hernández-Lucas I. , De la Cruz M. A. , Olvera L. , Morett E. , Medina-Aparicio L. , Ramírez-Trujillo J. A. , Vázquez A. , Fernández-Mora M. , Calva E. 
Published: February 2012

ABSTRACT

The
assT
gene encodes an arylsulfate sulfotransferase, an enzyme that catalyzes sulfuryl transfer from phenolic sulfate to a phenolic acceptor. In
Salmonella enterica
serovar Typhi IMSS-1, the
assT
gene is located upstream of the
dsbL
and
dsbI
genes, which are involved in a disulfide bond formation required for its activation. The
assT-dsbL-dsbI
gene cluster forms an operon transcribed by a LeuO-dependent promoter, in rich medium A (MA). Interestingly, in the absence of cloned
leuO
and in a Δ
leuO
background, two transcription start sites were detected for
assT
and two for
dsbL-dsbI
in minimal medium. The H-NS nucleoid protein repressed the expression of the
assT-dsbL-dsbI
LeuO-dependent operon, as well as of the
assT
transcriptional units. Thus, the expression of the
assT-dsbL-dsbI
gene cluster depends on the global regulatory proteins LeuO and H-NS, as well as on specific growth conditions.
The
rcbA
Gene Product Reduces Spontaneous and Induced Chromosome Breaks in Escherichia coli
Authors: Felczak Magdalena M. , Kaguni Jon M. 
Published: February 2012

ABSTRACT

Elevated levels of DnaA cause excessive initiation, which leads to an increased level of double-strand breaks that are proposed to arise when newly formed replication forks collide from behind with stalled or collapsed forks. These double-strand breaks are toxic in mutants that are unable to repair them. Using a multicopy suppressor assay to identify genes that suppress this toxicity, we isolated a plasmid carrying a gene whose function had been unknown. This gene, carried by the cryptic
rac
prophage, has been named
rcbA
for its ability to reduce the frequency of chromosome breaks. Our study shows that the colony formation of strains bearing mutations in
rep
,
recG
, and
rcbA
, like
recA
and
recB
mutants, is inhibited by an oversupply of DnaA and that a multicopy plasmid carrying
rcbA
neutralizes this inhibition. These and other results suggest that
rcbA
helps to maintain the integrity of the bacterial chromosome by lowering the steady-state level of double-strand breaks.
Characterization of PomA Mutants Defective in the Functional Assembly of the Na
+
-Driven Flagellar Motor in Vibrio alginolyticus
Authors: Takekawa Norihiro , Li Na , Kojima Seiji , Homma Michio 
Published: February 2012

ABSTRACT

The polar flagellar motor of
Vibrio alginolyticus
rotates using Na
+
influx through the stator, which is composed of 2 subunits, PomA and PomB. About a dozen stators dynamically assemble around the rotor, depending on the Na
+
concentration in the surrounding environment. The motor torque is generated by the interaction between the cytoplasmic domain of PomA and the C-terminal region of FliG, a component of the rotor. We had shown previously that mutations of FliG affected the stator assembly around the rotor, which suggested that the PomA-FliG interaction is required for the assembly. In this study, we examined the effects of various mutations mainly in the cytoplasmic domain of PomA on that assembly. All mutant stators examined, which resulted in the loss of motor function, assembled at a lower level than did the wild-type PomA. A His tag pulldown assay showed that some mutations in PomA reduced the PomA-PomB interaction, but other mutations did not. Next, we examined the ion conductivity of the mutants using a mutant stator that lacks the plug domain, PomA/PomB
ΔL
(Δ41–120), which impairs cell growth by overproduction, presumably because a large amount of Na
+
is conducted into the cells. Some PomA mutations suppressed this growth inhibition, suggesting that such mutations reduce Na
+
conductivity, so that the stators could not assemble around the rotor. Only the mutation H136Y did not impair the stator formation and ion conductivity through the stator. We speculate that this particular mutation may affect the PomA-FliG interaction and prevent activation of the stator assembly around the rotor.
Can lightweight rescuers adequately perform CPR according to 2010 resuscitation guideline requirements?
Authors: Krikscionaitiene Asta , Stasaitis Kestutis , Dambrauskiene Milda , Dambrauskas Zilvinas , Vaitkaitiene Egle , Dobozinskas Paulius , Vaitkaitis Dinas 
Published: February 2012

AimTo evaluate associations between rescuers' anthropometric characteristics and chest compressions (CC) depth according to 2010 resuscitation guidelines.Methods186 medical and pharmacy students, never trained in basic life support (BLS) before, underwent video self-instruction training. The participants were asked to perform a BLS test on a manikin connected to a PC for 6 min immediately after training, and the quality of the cardiopulmonary resuscitation (CPR) skills was evaluated.ResultsWomen with body weights less than 56 kg were 6.29 times more likely to produce insufficient CCs than women weighing 56–62.7 kg, and 4.72 times more likely to produce insufficient CCs compared with women weighing more than 62.7 kg.ConclusionsLightweight rescuers may have difficulty achieving the full compression depth of 5–6 cm required by new resuscitation guidelines. These rescuers require special attention during CPR training, with an emphasis on correct body positioning and use of body weight for CCs.
Analyzing the Pivotal Trial That Compared Sunitinib and IFN-α in Renal Cell Carcinoma, Using a Method That Assesses Tumor Regression and Growth
Authors: Stein Wilfred D. , Wilkerson Julia , Kim Sindy T. , Huang Xin , Motzer Robert J. , Fojo Antonio Tito , Bates Susan E. 
Published: February 2012

Abstract
Purpose: We applied a method that analyzes tumor response, quantifying the rates of tumor growth (g) and regression (d), using tumor measurements obtained while patients receive therapy. We used data from the phase III trial comparing sunitinib and IFN-α in metastatic renal cell carcinoma (mRCC) patients.
Methods: The analysis used an equation that extracts d and g.
Results: For sunitinib, overall survival (OS) was strongly correlated with log g (Rsq = 0.44, P &lt; 0.0001); much less with log d (Rsq = 0.04; P = 0.0002). The median g of tumors in these patients (0.00082 per days; log g = −3.09) was about half that (P &lt; 0.001) of tumors in patients receiving IFN-α (0.0015 per day; log g = −2.81). With IFN-α, the OS/log g correlation (Rsq = 0.14) was weaker. Values of g from measurements obtained by study investigators or central review were highly correlated (Rsq = 0.80). No advantage resulted in including data from central review in regressions. Furthermore, g can be estimated accurately four months before treatment discontinuation. Extrapolating g in a model that incorporates survival generates the hypothesis that g increased after discontinuation of sunitinib but did not accelerate.
Conclusions: In patients with mRCC, sunitinib reduced tumor growth rate, g, more than did IFN-α. Correlating g with OS confirms earlier analyses suggesting g may be an important clinical trial endpoint, to be explored prospectively and in individual patients. Clin Cancer Res; 18(8); 2374–81. ©2012 AACR.
Mutations in the Essential <i>Escherichia coli </i>Gene, <i>yqgF</i>, and Their Effects on Transcription
Authors: Iwamoto Akira , Osawa Atsushi , Kawai Makiko , Honda Hirofumi , Yoshida Saori , Furuya Nobuhisa , Kato Jun-ichi 
Published: February 2012

The <i>Escherichia coli</i> <i>yqgF</i> gene is highly conserved across a broad spectrum of bacterial genomes. The gene was first identified as being essential for cell growth during screening for targets for broad-spectrum antibiotics. YqgF is structurally similar to RuvC, a Holliday junction resolvase, but its function has not been established. This study describes the isolation of a temperature-sensitive <i>yqgF</i> mutant, the growth of which was inhibited by <i>rho</i> or <i>nusA</i> multicopy plasmids, indicating that YqgF is involved in transcription. Rho is a global transcription termination factor that acts at Rho-dependent terminator sites, which exist not only at the ends of genes but also within genes. The transcription of genes possessing intragenic, or upstream, Rho-dependent terminators was reduced in temperature-sensitive <i>yqgF</i> mutants. This transcription inhibition was sensitive to the Rho inhibitor, bicyclomycin. In addition, the transcription of mutant <i>tnaA</i> genes defective for upstream Rho-dependent termination was not significantly affected by the <i>yqgF</i> mutation. Taken together, these results suggest that YqgF is involved in anti-termination at Rho-dependent terminators in vivo.
Associations of Pregnancy Complications With Calculated Cardiovascular Disease Risk and Cardiovascular Risk Factors in Middle Age
Authors: Fraser Abigail , Nelson Scott M. , Macdonald-Wallis Corrie , Cherry Lynne , Butler Elaine , Sattar Naveed , Lawlor Debbie A. 
Published: February 2012

Background—
The nature and contribution of different pregnancy-related complications to future cardiovascular disease (CVD) and its risk factors and the mechanisms underlying these associations remain unclear.

Methods and Results—
We studied associations of pregnancy diabetes mellitus, hypertensive disorders of pregnancy, preterm delivery, and size for gestational age with calculated 10-year CVD risk (based on the Framingham score) and a wide range of cardiovascular risk factors measured 18 years after pregnancy (mean age at outcome assessment, 48 years) in a prospective cohort of 3416 women. Gestational diabetes mellitus was positively associated with fasting glucose and insulin, even after adjustment for potential confounders, whereas hypertensive disorders of pregnancy were associated with body mass index, waist circumference, blood pressure, lipids, and insulin. Large for gestational age was associated with greater waist circumference and glucose concentrations, whereas small for gestational age and preterm delivery were associated with higher blood pressure. The association with the calculated 10-year CVD risk based on the Framingham prediction score was odds ratio 1.31 (95 confidence interval, 1.11–1.53) for preeclampsia and 1.26 (95 confidence interval, 0.95–1.68) for gestational diabetes mellitus compared with women without preeclampsia and without gestational diabetes mellitus, respectively.

Conclusions—
Hypertensive disorders of pregnancy and pregnancy diabetes mellitus are independently associated with an increased calculated 10-year CVD risk. Preeclampsia may be the better predictor of future CVD because it was associated with a wider range of cardiovascular risk factors. Our results suggest that pregnancy may be an important opportunity for early identification of women at increased risk of CVD later in life.
Validation of the Bleeding Academic Research Consortium Definition of Bleeding in Patients With Coronary Artery Disease Undergoing Percutaneous Coronary Intervention
Authors: Ndrepepa Gjin , Schuster Tibor , Hadamitzky Martin , Byrne Robert A. , Mehilli Julinda , Neumann Franz-Josef , Richardt Gert , Schulz Stefanie , Laugwitz Karl-Ludwig , Massberg Steffen , Schömig Albert , Kastrati Adnan 
Published: February 2012

Background—
The Bleeding Academic Research Consortium (BARC) has recently proposed a unified definition of bleeding in patients receiving antithrombotic therapy. We investigated the relationship between bleeding events as defined by BARC and 1-year mortality in patients undergoing percutaneous coronary intervention (PCI) and assessed whether the BARC bleeding definition is superior to existing bleeding definitions in regard to mortality prediction in patients after PCI procedures.

Methods and Results—
This study represents a patient-level pooled analysis of 12 459 patients recruited in 6 randomized trials of patients undergoing PCI. Bleeding events were assessed with the use of BARC, Thrombolysis in Myocardial Infarction (TIMI), and Randomized Evaluation in PCI Linking Angiomax to Reduced Clinical Events (REPLACE-2) trial criteria. The primary outcome was 1-year mortality. Bleeding occurred in 1233 patients (9.9%) according to BARC (679 patients or 5.4% with BARC class ≥2 bleeding), in 374 patients (3.0%) according to TIMI, and in 491 patients (3.9%) according to REPLACE-2 criteria. There were 340 deaths (2.7%) over the first year after PCI. BARC class ≥2 bleeding was associated with a significant increase in 1-year mortality (adjusted hazard ratio 2.72; 95% confidence interval, 2.03–3.63). The predictivity of a multivariable model for 1-year mortality was significantly improved after inclusion of bleeding defined according to BARC to an extent comparable to that provided by TIMI and REPLACE-2 criteria.

Conclusions—
The present study demonstrated a close association between bleeding events defined according to BARC and 1-year mortality after PCI.
Associations of Maternal Prepregnancy Body Mass Index and Gestational Weight Gain With Adult Offspring Cardiometabolic Risk Factors
Authors: Hochner Hagit , Friedlander Yechiel , Calderon-Margalit Ronit , Meiner Vardiella , Sagy Yael , Avgil-Tsadok Meytal , Burger Ayala , Savitsky Bella , Siscovick David S. , Manor Orly 
Published: February 2012

Background—
Accumulating evidence demonstrates that both maternal prepregnancy body mass index (mppBMI) and gestational weight gain (GWG) are associated with adult offspring adiposity. However, whether these maternal attributes are related to other cardiometabolic risk factors in adulthood has not been comprehensively studied.

Methods and Results—

We used a birth cohort of 1400 young adults born in Jerusalem who had extensive archival data and clinical information at 32 years of age to prospectively examine the associations of mppBMI and GWG with adiposity and related cardiometabolic outcomes. Greater mppBMI, independently of GWG and confounders, was significantly associated with higher offspring BMI, waist circumference, systolic and diastolic blood pressures, insulin, and triglycerides and with lower high-density lipoprotein cholesterol. For example, the effect sizes were translated to nearly 5 kg/m
2
higher mean BMI, 8.4 cm higher waist circumference, 0.13 mmol/L (11.4 mg/dL) higher triglycerides, and 0.10 mmol/L (3.8 mg/dL) lower high-density lipoprotein cholesterol among offspring of mothers within the upper mppBMI quartile (mppBMI >26.4 kg/m
2
) compared with the lower quartile (mppBMI <21.0 kg/m
2
). GWG, independently of mppBMI, was positively associated with offspring adiposity; differences of 1.6 kg/m
2
in BMI and 2.4 cm in waist were observed when offspring of mothers in the upper (GWG >14 kg) and lower (GWG <9 kg) quartiles of GWG were compared. Further adjustment for offspring adiposity attenuated the observed associations to the null.

Conclusions—
Maternal size both before and during pregnancy is associated with cardiometabolic risk factors in young adult offspring. The associations appear to be driven mainly by offspring adiposity. Future studies that explore mechanisms underlying the intergenerational cycle of obesity are warranted to identify potentially novel targets for cardiometabolic risk-reduction interventions.
Granting Conscientious Exemptions: The Need to Take Sides
Authors: Nehushtan Yossi 
Published: February 2012

Abstract
There are several possible views of the proper way in which the state should respond to claims to be granted conscientious exemptions. This article discusses, and ultimately rejects, two main approaches to the issue of granting conscientious exemptions: the neutral approach and the ‘equal-regard’ approach. According to the neutral approach the decision whether to grant an exemption should not be affected, at least not directly, by the content of a person’s conscience. The equal-regard approach suggests that, when an exemption is granted to a non-religious conscientious objector, an exemption should also be granted to his equivalent religious objector, and vice versa. It is suggested that the state has to take sides and to evaluate the content of one’s conscience in order to decide whether to grant him an exemption from the law. The general argument that intolerance should normally not be tolerated provides one reason, among others, why the content of someone’s conscience is significant when deciding when to grant conscientious exemptions.
Effects of Aerosol Solubility and Regeneration on Mixed-Phase Orographic Clouds and Precipitation
Authors: Xue Lulin , Teller Amit , Rasmussen Roy , Geresdi Istvan , Pan Zaitao , Liu Xiaodong 
Published: February 2012

Abstract
A detailed bin aerosol-microphysics scheme has been implemented into the Weather Research and Forecast Model to investigate the effects of aerosol solubility and regeneration on mixed-phase orographic clouds and precipitation. Two-dimensional simulations of idealized moist flow over two identical bell-shaped mountains were carried out using different combinations of aerosol regeneration, solubility, loading, ice nucleation parameterizations, and humidity. The results showed the following. 1) Pollution and regenerated aerosols suppress the riming process in mixed-phase clouds by narrowing the drop spectrum. In general, the lower the aerosol solubility, the broader the drop spectrum and thus the higher the riming rate. When the solubility of initial aerosol increases with an increasing size of aerosol particles, the modified solubility of regenerated aerosols reduces precipitation. 2) The qualitative effects of aerosol solubility and regeneration on mixed-phase orographic clouds and precipitation are not affected by different ice nucleation parameterizations. 3) The impacts of aerosol properties on rain are similar in both warm- and mixed-phase clouds. Aerosols exert weaker impact on snow and stronger impact on graupel compared to rain as graupel production is strongly affected by riming. 4) Precipitation of both warm- and mixed-phase clouds is most sensitive to aerosol regeneration, then to aerosol solubility, and last to modified solubility of regenerated aerosol; however, the precipitation amount is mainly controlled by humidity and aerosol loading.