bluuebunny/crossref_metadata_2025_split huggingface dataset:
PhoY2 of Mycobacteria Is Required for Metabolic Homeostasis and Stress Response
Authors: Wang Chuan , Mao Yi , Yu Jia , Zhu Lin , Li Ming , Wang Decheng , Dong Dandan , Liu Jun , Gao Qian 
Published: November 2012

ABSTRACT

The ability of pathogenic mycobacteria to adapt to diverse environments is essential for their success as pathogens. Here we describe a transposon-inactivated
phoY2
mutant of
Mycobacterium marinum
. PhoY2 of mycobacteria is a functional homologue of PhoU in
Escherichia coli
and an important component of the Pho regulon. We found that PhoY2 is required for maintaining intracellular inorganic phosphate (P
i
) homeostasis and balanced energy and redox states. Disruption of
phoY2
resulted in elevated levels of intracellular poly-P
i
and ATP and an elevated NAD
+
/NADH ratio, and the mutant strain exhibited increased sensitivity to environmental stress conditions, including nutrient deprivation as well as SDS and antibiotic treatments. Taken together, our results suggest that PhoY2 is required for maintaining metabolic homeostasis and adaptation to stress conditions, which may provide an explanation for the suggested role of PhoY2 in drug tolerance.
The tRNA
arg
Gene and
engA
Are Essential Genes on the 1.7-Mb pSymB Megaplasmid of Sinorhizobium meliloti and Were Translocated Together from the Chromosome in an Ancestral Strain
Authors: diCenzo George , Milunovic Branislava , Cheng Jiujun , Finan Turlough M. 
Published: November 2012

ABSTRACT

Bacterial genomes with two (or more) chromosome-like replicons are known, and these appear to be particularly frequent in alphaproteobacteria. The genome of the N
2
-fixing alfalfa symbiont
Sinorhizobium meliloti
1021 contains a 3.7-Mb chromosome and 1.4-Mb (pSymA) and 1.7-Mb (pSymB) megaplasmids. In this study, the tRNA
arg
and
engA
genes, located on the pSymB megaplasmid, are shown to be essential for growth. These genes could be deleted from pSymB when copies were previously integrated into the chromosome. However, in the closely related strain
Sinorhizobium fredii
NGR234, the tRNA
arg
and
engA
genes are located on the chromosome, in a 69-kb region designated the
engA-
tRNA
arg
-rmlC
region. This region includes
bacA
, a gene that is important for intracellular survival during host-bacterium interactions for
S. meliloti
and the related alphaproteobacterium
Brucella abortus
. The
engA-
tRNA
arg
-rmlC
region lies between the
kdgK
and
dppF2
(NGR_c24410) genes on the
S. fredii
chromosome. Synteny analysis showed that
kdgK
and
dppF2
orthologues are adjacent to each other on the chromosomes of 15 sequenced strains of
S. meliloti
and
Sinorhizobium medicae
, whereas the 69-kb
engA-
tRNA
arg
-rmlC
region is present on the pSymB-equivalent megaplasmids. This and other evidence strongly suggests that the
engA-
tRNA
arg
-rmlC
region translocated from the chromosome to the progenitor of pSymB in an ancestor common to
S. meliloti
and
S. medicae
. To our knowledge, this work represents one of the first experimental demonstrations that essential genes are present on a megaplasmid.
Gliding Motility and Por Secretion System Genes Are Widespread among Members of the Phylum Bacteroidetes
Authors: McBride Mark J. , Zhu Yongtao 
Published: November 2012

ABSTRACT

The phylum
Bacteroidetes
is large and diverse, with rapid gliding motility and the ability to digest macromolecules associated with many genera and species. Recently, a novel protein secretion system, the Por secretion system (PorSS), was identified in two members of the phylum, the gliding bacterium
Flavobacterium johnsoniae
and the nonmotile oral pathogen
Porphyromonas gingivalis
. The components of the PorSS are not similar in sequence to those of other well-studied bacterial secretion systems. The
F. johnsoniae
PorSS genes are a subset of the gliding motility genes, suggesting a role for the secretion system in motility. The
F. johnsoniae
PorSS is needed for assembly of the gliding motility apparatus and for secretion of a chitinase, and the
P. gingivalis
PorSS is involved in secretion of gingipain protease virulence factors. Comparative analysis of 37 genomes of members of the phylum
Bacteroidetes
revealed the widespread occurrence of gliding motility genes and PorSS genes. Genes associated with other bacterial protein secretion systems were less common. The results suggest that gliding motility is more common than previously reported. Microscopic observations confirmed that organisms previously described as nonmotile, including
Croceibacter atlanticus
, “
Gramella forsetii
,”
Paludibacter propionicigenes
,
Riemerella anatipestifer
, and
Robiginitalea biformata
, exhibit gliding motility. Three genes (
gldA
,
gldF
, and
gldG
) that encode an apparent ATP-binding cassette transporter required for
F. johnsoniae
gliding were absent from two related gliding bacteria, suggesting that the transporter may not be central to gliding motility.
Public attitudes to death and dying in the UK: a review of published literature
Authors: Cox Karen , Bird Lydia , Arthur Anthony , Kennedy Sheila , Pollock Kristian , Kumar Arun , Stanton Wendy , Seymour Jane 
Published: November 2012

BackgroundPublic attitudes are important in shaping public policy and the political will that determines future service provision. They also help to identify priorities for public education. This paper presents a review and synthesis of published literature on public attitudes to death and dying in the UK from 1990.MethodThe approach to the review was systematic and involved searching for published research in five databases combined with reviewing references proposed by experts in the field and following up relevant citations from identified sources. The selected sources were assessed by the review team and analysed using a thematic approach.ResultsThe review identified 22 sources reporting 19 studies which met our criteria for inclusion in the descriptive analysis. Three descriptive themes were identified: preferences relating to death and dying, attitudes to euthanasia and attitudes to life-sustaining treatments and interventions.ConclusionThe review outcomes challenge widespread assumptions about public attitudes to death and dying and identify the need for more rigorous work to better understand public views on dying and death. Such work is needed if public health services are to meet the expectations and reflect the wishes of individuals in this area in future.
The balancing point: understanding uptake of advance directive forms in a rural Australian community
Authors: Sinclair Craig , Auret Kirsten Anne , Burgess Ashlee 
Published: November 2012

ObjectivesThe study was conducted in Western Australia, focusing on the attitudes of older, rural, non-hospitalised people towards newly legislated advance care planning (ACP) documents. This study explored baseline awareness and perception of advance directive (AD) forms and factors relevant to their utilisation, using the transtheoretical model as a theoretical framework.MethodsSixty-two adults were recruited from residential aged care facilities, community care organisations, general practice, an oncology service and a law firm. Semi-structured interviews were undertaken. These were transcribed and thematically analysed by the authors.ResultsParticipants gave responses that were consistent with different stages of the transtheoretical model. Perceived susceptibility to the negative consequences of not engaging in AD form utilisation was a trigger for further contemplation. The presence of adequate personal empowerment was important for successful completion of AD forms. There was also qualitative evidence of a negative relationship between perceived susceptibility and empowerment regarding AD form utilisation.ConclusionsPromoting balance between a person's perceived susceptibility and empowerment may be an effective method of increasing engagement with AD forms.
Will PAXgene substitute formalin? A morphological and molecular comparative study using a new fixative system
Authors: Belloni Benedetta , Lambertini Chiara , Nuciforo Paolo , Phillips Jay , Bruening Eric , Wong Stephane , Dummer Reinhard 
Published: November 2012

Formalin fixation and paraffin embedding present the standard procedures for conserving clinical tissues for histological analysis. However, molecular analysis is impaired by the cross linking properties of formalin. The PAXgene tissue system (PreAnalytix, Switzerland) is a new formalin-free tissue collection device.AimsIn this study we aimed to evaluate this new tissue preservation technique in comparison with formalin fixation and fresh frozen tissue samples.Methods12 melanoma biopsy samples were divided and fixed simultaneously with formalin, PAXgene or fresh frozen in liquid nitrogen and analysed with regard to morphology, immunohistochemistry, DNA and RNA content and quality. Markers of melanocytic differentiation and tumour cell proliferation were used.ResultsMorphology was well preserved in PAXPE samples. However, 5 out of 11 immunohistochemical markers showed significantly lower overall staining and staining intensity with PAXPE tissues in comparison with formalin-fixed, paraffin-embedded (FFPE). Increasing membrane permeability through adding a detergent did proportionally increase staining intensity in PAXPE samples. Amplification of different mRNA amplicons showed a direct relationship with the size of the amplicon with greater template integrity observed in PAXPE samples. Sequencing and mutational analysis of DNA samples were comparable for all the different fixation methods, while the level of DNA fragmentation seemed to be lower in PAXPE compared with FFPE tissues.ConclusionsThe switch from formalin to PAXgene fixation would require a re-evaluation of immunohistochemical markers and staining procedures originally developed for FFPE tissues. Our data demonstrate that PAXPE fixation offers some advantages concerning molecular analysis. However, these advantages would not justify substituting formalin fixation in any routine pathology laboratory.
Ultrashort imaging to reperfusion time interval arrests core expansion in endovascular therapy for acute ischemic stroke
Authors: Almekhlafi Mohammed A , Eesa Muneer , Menon Bijoy K , Demchuk Andrew M , Goyal Mayank 
Published: November 2012

Background and purposeThe shorter the time interval between the estimation of the ischemic core by imaging and reperfusion, the more likely that core expansion is minimized. We aimed to assess the feasibility of achieving an ultrashort imaging to reperfusion time in routine clinical practice.MethodsThe study subjects were a prospective cohort of patients with acute ischemic stroke treated with endovascular therapy in a tertiary center in whom an imaging to reperfusion time of <60 min was achieved.ResultsImaging to reperfusion time of <60 min was accomplished in 11 patients. The median baseline National Institutes of Health Stroke Scale (NIHSS) score was 11 and the median baseline Alberta Stroke Program Early CT Score (ASPECTS) was 8. The median time interval from imaging to endovascular reperfusion was 47 min. The median ASPECTS score on the 24 h CT scan was also 8 and the median 24 h NIHSS score was 1. Upon discharge, 82% of patients achieved a modified Rankin scale score of ≤1.ConclusionsAn imaging to endovascular reperfusion time of <60 min is feasible and resulted in minimal core expansion on follow-up imaging in patients with acute ischemic stroke.
Molecular Mechanisms Responsible for the Reduced Expression of Cholesterol Transporters From Macrophages by Low-Dose Endotoxin
Authors: Maitra Urmila , Li Liwu 
Published: November 2012

Objective—
Atherosclerosis is characterized as a chronic inflammatory condition that involves cholesterol deposition in arteries. Together with scavenger receptor B1 (SR-B1), the ATP-binding cassette transporters ABCA1 and ABCG1 are the major components of macrophage cholesterol efflux. Recent studies have shown that low-grade inflammation plays a distinct regulatory role in the expression of SR-B1 and ABCA1/ABCG1. However, the mechanisms linking low-grade inflammation and cholesterol accumulation are poorly understood.

Methods and Results—
Using primary bone-marrow-derived macrophages, we demonstrate that subclinical low-dose lipopolysaccharide potently reduces the expression of SR-B1 and ABCA1/ABCG1, as well as cholesterol efflux from macrophages through interleukin-1 receptor-associated kinase 1 and Toll-interacting-protein. Low-dose lipopolysaccharide downregulates the nuclear levels of retinoic acid receptor-α, leading to their reduced binding to the promoters of SR-B1 and ABCA1/ABCG1. We observe that glycogen synthase kinase 3β activation by low-dose lipopolysaccharide through interleukin-1 receptor-associated kinase 1 and Toll-interacting-protein is responsible for reduced levels of retinoic acid receptor-α, and reduced expression of SR-B1 and ABCA1/ABCG1. Interleukin-1 receptor-associated kinase M, however, counteracts the function of interleukin-1 receptor associated kinase 1.

Conclusion—
Collectively, our data reveal a novel intracellular network regulated by low-dose endotoxemia that disrupts cholesterol efflux from macrophages and leads to the pathogenesis of atherosclerosis.
Transglutaminase Inhibitors Attenuate Vascular Calcification in a Preclinical Model
Authors: Beazley Kelly E. , Banyard Derek , Lima Florence , Deasey Stephanie C. , Nurminsky Dmitry I. , Konoplyannikov Mikhail , Nurminskaya Maria V. 
Published: November 2012

Objective—
In vitro, transglutaminase-2 (TG2)–mediated activation of the β-catenin signaling pathway is central in warfarin-induced calcification, warranting inquiry into the importance of this signaling axis as a target for preventive therapy of vascular calcification in vivo.

Methods and Results—
The adverse effects of warfarin-induced elastocalcinosis in a rat model include calcification of the aortic media, loss of the cellular component in the vessel wall, and isolated systolic hypertension, associated with accumulation and activation of TG2 and activation of β-catenin signaling. These effects of warfarin can be completely reversed by intraperitoneal administration of the TG2-specific inhibitor KCC-009 or dietary supplementation with the bioflavonoid quercetin, known to inhibit β-catenin signaling. Our study also uncovers a previously uncharacterized ability of quercetin to inhibit TG2. Quercetin reversed the warfarin-induced increase in systolic pressure, underlying the functional consequence of this treatment. Molecular analysis shows that quercetin diet stabilizes the phenotype of smooth muscle and prevents its transformation into osteoblastic cells.

Conclusion—
Inhibition of the TG2/β-catenin signaling axis seems to prevent warfarin-induced elastocalcinosis and to control isolated systolic hypertension.
Donor and Recipient Cell Surface Colony Stimulating Factor-1 Promote Neointimal Formation in Transplant-Associated Arteriosclerosis
Authors: Hiroyasu Shungo , Chinnasamy Prameladevi , Hou Rong , Hotchkiss Kylie , Casimiro Isabel , Dai Xu-ming , Stanley E. Richard , Sibinga Nicholas E.S. 
Published: November 2012

Objective—

Transplant-associated arteriosclerosis manifests as progressive vascular neointimal expansion throughout the arterial system of allografted solid organs, and eventually compromises graft perfusion and function. Allografts placed in colony stimulating factor (CSF)-1-deficient osteopetrotic (
Csf1

op

/Csf1

op

) mice develop very little neointima, a finding attributed to impaired recipient macrophage function. We examined how CSF-1 affects neointima-derived vascular smooth muscle cells, tested the significance of CSF-1 expressed in donor tissue, and evaluated the contribution of secreted versus cell surface CSF-1 isoforms in transplant-associated arteriosclerosis.

Methods and Results—
CSF-1 activated specific signaling pathways to promote migration, survival, and proliferation of cultured vascular smooth muscle cells. Tumor necrosis factor-α addition increased CSF-1 and CSF-1 receptor expression, and tumor necrosis factor-α-driven proliferation was blocked by anti-CSF-1 antibody. In a mouse vascular allograft model, lack of recipient or donor CSF-1 impaired neointima formation; the latter suggests local CSF-1 function within the allograft. Moreover, reconstitution of donor or recipient cell surface CSF-1, without secreted CSF-1, restored neointimal formation.

Conclusion—
Vascular smooth muscle cells activation, including that mediated by tumor necrosis factor-α, can be driven in an autocrine/juxtacrine manner by CSF-1. These studies provide evidence for local function of CSF-1 in neointimal expansion, and identify CSF-1 signaling in vascular smooth muscle cells, particularly cell surface CSF-1 signaling, as a target for therapeutic strategies in transplant-associated arteriosclerosis.
Galectin-3 Mediates Aldosterone-Induced Vascular Fibrosis
Authors: Calvier Laurent , Miana Maria , Reboul Pascal , Cachofeiro Victoria , Martinez-Martinez Ernesto , de Boer Rudolf A. , Poirier Françoise , Lacolley Patrick , Zannad Faiez , Rossignol Patrick , López-Andrés Natalia 
Published: November 2012

Objective—
Aldosterone (Aldo) is involved in arterial stiffness and heart failure, but the mechanisms have remained unclear. Galectin-3 (Gal-3), a β-galactoside-binding lectin, plays an important role in inflammation, fibrosis, and heart failure. We investigated here whether Gal-3 is involved in Aldo-induced vascular fibrosis.

Methods and Results—
In rat vascular smooth muscle cells Gal-3 overexpression enhanced specifically collagen type I synthesis. Moreover Gal-3 inhibition by modified citrus pectin or small interfering RNA blocked Aldo-induced collagen type I synthesis. Rats were treated with Aldo-salt combined with spironolactone or modified citrus pectin for 3 weeks. Hypertensive Aldo-treated rats presented vascular hypertrophy, inflammation, fibrosis, and increased aortic Gal-3 expression. Spironolactone or modified citrus pectin treatment reversed all the above effects. Wild-type and Gal-3 knock-out mice were treated with Aldo for 6 hours or 3 weeks. Aldo increased aortic Gal-3 expression, inflammation, and collagen type I in wild-type mice at both the short- and the long-term, whereas no changes occurred in Gal-3 knock-out mice.

Conclusion—
Our data indicate that Gal-3 is required for inflammatory and fibrotic responses to Aldo in vascular smooth muscle cells in vitro and in vivo, suggesting a key role for Gal-3 in vascular fibrosis.
Rhythm Versus Rate Control Therapy and Subsequent Stroke or Transient Ischemic Attack in Patients With Atrial Fibrillation
Authors: Tsadok Meytal Avgil , Jackevicius Cynthia A. , Essebag Vidal , Eisenberg Mark J. , Rahme Elham , Humphries Karin H. , Tu Jack V. , Behlouli Hassan , Pilote Louise 
Published: November 2012

Background—
Stroke is a debilitating condition with an increased risk in patients with atrial fibrillation. Although data from clinical trials suggest that both rate and rhythm control are acceptable approaches with comparable rates of mortality in the short term, it is unclear whether stroke rates differ between patients who filled prescriptions for rhythm or rate control therapy.

Methods and Results—

We conducted a population-based observational study of Quebec patients ≥65 years with a diagnosis of atrial fibrillation during the period 1999 to 2007 with the use of linked administrative data from hospital discharge and prescription drug claims databases. We compared rates of stroke or transient ischemic attack (TIA) among patients using rhythm (class Ia, Ic, and III antiarrhythmics), versus rate control (β-blockers, calcium channel blockers, and digoxin) treatment strategies (either current or new users). The cohort consisted of 16 325 patients who filled a prescription for rhythm control therapy (with or without rate control therapy) and 41 193 patients who filled a prescription for rate control therapy, with a mean follow-up of 2.8 years (maximum 8.2 years). A lower proportion of patients on rhythm control therapy than on rate control therapy had a CHADS
2
(congestive heart failure, hypertension, age ≥75 years, diabetes mellitus, and previous stroke or TIA) score of ≥2 (58.1% versus 67.0%,
P
<0.001). Treatment with any antithrombotic drug was comparable in the 2 groups (76.8% in rhythm control versus 77.8% in rate control group). Crude stroke/TIA incidence rate was lower in patients treated with rhythm control in comparison with rate control therapy (1.74 versus 2.49, per 100 person-years,
P
<0.001). This association was more marked in patients in the moderate- and high-risk groups for stroke according to the CHADS
2
risk score. In multivariable Cox regression analysis, rhythm control therapy was associated with a lower risk of stroke/TIA in comparison with rate control therapy (adjusted hazard ratio, 0.80; 95% confidence interval, 0.74, 0.87). The lower stroke/TIA rate was confirmed in a propensity score–matched cohort.

Conclusions—
In comparison with rate control therapy, the use of rhythm control therapy was associated with lower rates of stroke/TIA among patients with atrial fibrillation, in particular, among those with moderate and high risk of stroke.
GRK2-Mediated Inhibition of Adrenergic and Dopaminergic Signaling in Right Ventricular Hypertrophy
Authors: Piao Lin , Fang Yong-Hu , Parikh Kishan S. , Ryan John J. , D'Souza Karen M. , Theccanat Tiju , Toth Peter T. , Pogoriler Jennifer , Paul Jonathan , Blaxall Burns C. , Akhter Shahab A. , Archer Stephen L. 
Published: November 2012

Background—
The cause and consequences of impaired adrenergic signaling in right ventricular failure/hypertrophy (RVH) are poorly understood. We hypothesized that G protein–coupled receptor kinase-2 (GRK2)–mediated uncoupling of β-adrenergic receptor signaling impairs inotropic reserve. The implications of right ventricular (RV) adrenergic remodeling for inotrope selection and the therapeutic benefit of interrupting Gβγ–GRK2 interaction, using gallein, were tested.

Methods and Results—

Chamber-specificity and cellular localization of adrenergic remodeling were compared in rodent RVH associated with pulmonary arterial hypertension (PAH-RVH; SU5416+chronic-hypoxia or Monocrotaline) versus pulmonary artery banding–induced RVH (PAB-RVH). Results were corroborated in RV arrays from 10 PAH patients versus controls. Inotropic reserve was assessed in RV- and left ventricular–Langendorff models and in vivo. Gallein therapy (1.8 mg/kg/day ×2-weeks) was assessed. Despite similar RVH, cardiac output (58.3±4.9 versus 82.9±4.8 mL/min;
P
<0.001) and treadmill distance (41.5±11.6 versus 244.1±12.4 m;
P
<0.001) were lower in PAH-RVH versus PAB-RVH. In PAH-RVH versus PAB-RVH there was greater downregulation of β1-, α1- and dopamine-1 receptors, more left ventricular involvement, and greater impairment of RV contractile reserve. RV GRK2 activity increased in parallel with a reduction in both adrenergic receptor expression and inotrope-stimulated cAMP levels (
P
<0.01). β1-receptor downregulation also occurred in human PAH-RVH. Dobutamine was superior to dopamine as an RV inotrope, both ex vivo and in vivo.

Conclusions—
GRK2-mediated desensitization-downregulation of adrenergic and dopaminergic receptors impairs inotropic reserve in PAH-RVH. Acute inotropic support in RVH is best accomplished by dobutamine, reflecting its better coupling to adenylyl cyclase and the reliance of dopamine on dopamine-1–receptor signaling, which is impaired in RVH. Inhibiting Gβγ–GRK2 interactions has therapeutic benefit in RVH.