bluuebunny/crossref_metadata_2025_split huggingface dataset:
Angiotensin‐(1–12) in the rostral ventrolateral medullary pressor area of the rat elicits sympathoexcitatory responses
Authors: Arakawa Hideki , Kawabe Kazumi , Sapru Hreday N. 
Published: June 2012

New Findings
What is the central question of this study?Although brain angiotensin‐(1–12), a new member of the RAS, levels are significantly higher than angiotensin II very little information is available on its mechanism of central actions.
What is the main finding and its importance?This study provides evidence that both ACE and chymase‐mediated conversion of angiotensin‐(1–12) to angiotensin II are key in its cardiovascular actions involving angiotensin II type 1 and not type 2 receptors.
The rostral ventrolateral medullary pressor area (RVLM) is known to be critical in the regulation of cardiovascular function. In this study, it was hypothesized that the RVLM may be one of the sites of cardiovascular actions of a newly discovered angiotensin, angiotensin‐(1–12) [Ang‐(1–12)]. Experiments were carried out in urethane‐anaesthetized, artificially ventilated, adult male Wistar rats. The RVLM was identified by microinjections of l‐glutamate (5 mm). The volume of all microinjections into the RVLM was 100 nl. Microinjections of Ang‐(1–12) (0.1–1.0 mm) into the RVLM elicited increases in mean arterial pressure and heart rate. Maximal cardiovascular responses were elicited by 0.5 mm Ang‐(1–12); this concentration was used in the other experiments described. Microinjections of Ang‐(1–12) increased greater splanchnic nerve activity. The tachycardic responses to Ang‐(1–12) were not altered by bilateral vagotomy. The cardiovascular responses elicited by Ang‐(1–12) were attenuated by microinjections of an angiotensin II type 1 receptor (AT1R) antagonist (losartan), but not an AT2R antagonist (PD123319), into the RVLM. Combined inhibition of angiotensin‐converting enzyme and chymase in the RVLM abolished Ang‐(1–12)‐induced responses. Angiotensin‐(1–12)‐immunoreactive cells were present in the RVLM. Angiotensin II type 1 receptors and phenylethanolamine‐N‐methyl‐transferase were present in the RVLM neurons retrogradely labelled by microinjections of Fluoro‐Gold into the intermediolateral cell column of the thoracic spinal cord. Angiotensin‐(1–12)‐containing neurons in the hypothalamic paraventricular nucleus did not project to the RVLM. These results indicated that: (1) microinjections of Ang‐(1–12) into the RVLM elicited increases in mean arterial pressure, heart rate and greater splanchnic nerve activity; (2) both angiotensin‐converting enzyme and chymase were needed to convert Ang‐(1–12) into angiotensin II; and (3) AT1Rs, but not AT2Rs, in the RVLM mediated the Ang‐(1–12)‐induced responses.
Impact of Processing Method on Recovery of Bacteria from Wipes Used in Biological Surface Sampling
Authors: Downey Autumn S. , Da Silva Sandra M. , Olson Nathan D. , Filliben James J. , Morrow Jayne B. 
Published: June 2012

ABSTRACT

Environmental sampling for microbiological contaminants is a key component of hygiene monitoring and risk characterization practices utilized across diverse fields of application. However, confidence in surface sampling results, both in the field and in controlled laboratory studies, has been undermined by large variation in sampling performance results. Sources of variation include controlled parameters, such as sampling materials and processing methods, which often differ among studies, as well as random and systematic errors; however, the relative contributions of these factors remain unclear. The objective of this study was to determine the relative impacts of sample processing methods, including extraction solution and physical dissociation method (vortexing and sonication), on recovery of Gram-positive (
Bacillus cereus
) and Gram-negative (
Burkholderia thailandensis
and
Escherichia coli
) bacteria from directly inoculated wipes. This work showed that target organism had the largest impact on extraction efficiency and recovery precision, as measured by traditional colony counts. The physical dissociation method (PDM) had negligible impact, while the effect of the extraction solution was organism dependent. Overall, however, extraction of organisms from wipes using phosphate-buffered saline with 0.04% Tween 80 (PBST) resulted in the highest mean recovery across all three organisms. The results from this study contribute to a better understanding of the factors that influence sampling performance, which is critical to the development of efficient and reliable sampling methodologies relevant to public health and biodefense.
Emergent Macrophytes Act Selectively on Ammonia-Oxidizing Bacteria and Archaea
Authors: Trias Rosalia , Ruiz-Rueda Olaya , García-Lledó Arantzazu , Vilar-Sanz Ariadna , López-Flores Rocío , Quintana Xavier D. , Hallin Sara , Bañeras Lluís 
Published: June 2012

ABSTRACT

Ammonia-oxidizing bacteria (AOB) and archaea (AOA) were quantified in the sediments and roots of dominant macrophytes in eight neutral to alkaline coastal wetlands. The AOA dominated in most samples, but the bacterial-to-archaeal
amoA
gene ratios increased with increasing ammonium levels and pH in the sediments. For all plant species, the ratios increased on the root surface relative to the adjacent bulk sediment. This suggests that root surfaces in these environments provide conditions favoring enrichment of AOB.
Chromosomal Complementation Using Tn
7
Transposon Vectors in Enterobacteriaceae
Authors: Crépin Sébastien , Harel Josée , Dozois Charles M. 
Published: June 2012

ABSTRACT

Genetic complementation in many bacteria is commonly achieved by reintroducing functional copies of the mutated or deleted genes on a recombinant plasmid. Chromosomal integration systems using the Tn
7
transposon have the advantage of providing a stable single-copy integration that does not require selective pressure. Previous Tn
7
systems have been developed, although none have been shown to work effectively in a variety of enterobacteria. We have developed several mini-Tn
7
and transposase vectors to provide a more versatile system. Transposition of Tn
7
at the chromosomal
att
Tn
7
site was achieved by a classical conjugation approach, wherein the donor strain harbored the mini-Tn
7
vector and the recipient strain possessed the transposase vector. This approach was efficient for five different pathogenic enterobacterial species. Thus, this system provides a useful tool for single-copy complementation at an episomal site for research in bacterial genetics and microbial pathogenesis. Furthermore, these vectors could also be used for the introduction of foreign genes for use in biotechnology applications, vaccine development, or gene expression and gene fusion constructs.
Influence of the Plant Defense Response to Escherichia coli O157:H7 Cell Surface Structures on Survival of That Enteric Pathogen on Plant Surfaces
Authors: Seo Suengwook , Matthews Karl R. 
Published: June 2012

ABSTRACT

Consumption of fresh and fresh-cut fruits and vegetables contaminated with
Escherichia coli
O157:H7 has resulted in hundreds of cases of illness and, in some instances, death. In this study, the influence of cell surface structures of
E. coli
O157:H7, such as flagella, curli fimbriae, lipopolysaccharides, or exopolysaccharides, on plant defense responses and on survival or colonization on the plant was investigated. The population of the
E. coli
O157:H7 ATCC 43895 wild-type strain was significantly lower on wild-type
Arabidopsis
plants than that of the 43895 flagellum-deficient mutant. The population of the
E. coli
O157:H7 43895 flagellum mutant was greater on both wild-type and
npr1-1
mutant (nonexpressor of pathogenesis-related [PR] genes) plants and resulted in less PR gene induction, estimated based on a weak β-glucuronidase (GUS) signal, than did the 43895 wild-type strain. These results suggest that the flagella, among the other pathogen-associated molecular patterns (PAMPs), made a substantial contribution to the induction of plant defense response and contributed to the decreased numbers of the
E. coli
O157:H7 ATCC 43895 wild-type strain on the wild-type
Arabidopsis
plant. A curli-deficient
E. coli
O157:H7 86-24 strain survived better on wild-type
Arabidopsis
plants than the curli-producing wild-type 86-24 strain did. The curli-deficient
E. coli
O157:H7 86-24 strain exhibited a GUS signal at a level substantially lower than that of the curli-producing wild-type strain. Curli were recognized by plant defense systems, consequently affecting bacterial survival. The cell surface structures of
E. coli
O157:H7 have a significant impact on the induction of differential plant defense responses, thereby impacting persistence or survival of the pathogen on plants.
Surface Display of N-Terminally Anchored Invasin by Lactobacillus plantarum Activates NF-κB in Monocytes
Authors: Fredriksen Lasse , Kleiveland Charlotte R. , Olsen Hult Lene T. , Lea Tor , Nygaard Cathrine S. , Eijsink Vincent G. H. , Mathiesen Geir 
Published: June 2012

ABSTRACT

The probiotic lactic acid bacterium
Lactobacillus plantarum
is a potential delivery vehicle for mucosal vaccines because of its generally regarded as safe (GRAS) status and ability to persist at the mucosal surfaces of the human intestine. However, the inherent immunogenicity of vaccine antigens is in many cases insufficient to elicit an efficient immune response, implying that additional adjuvants are needed to enhance the antigen immunogenicity. The goal of the present study was to increase the proinflammatory properties of
L. plantarum
by expressing a long (D1 to D5 [D1-D5]) and a short (D4-D5) version of the extracellular domain of invasin from the human pathogen
Yersinia pseudotuberculosis
. To display these proteins on the bacterial surface, four different N-terminal anchoring motifs from
L. plantarum
were used, comprising two different lipoprotein anchors, a transmembrane signal peptide anchor, and a LysM-type anchor. All these anchors mediated surface display of invasin, and several of the engineered strains were potent activators of NF-κB when interacting with monocytes in cell culture. The most distinct NF-κB responses were obtained with constructs in which the complete invasin extracellular domain was fused to a lipoanchor. The proinflammatory
L. plantarum
strains constructed here represent promising mucosal delivery vehicles for vaccine antigens.
Microsatellite Markers for Characterization of Native and Introduced Populations of Plasmopara viticola, the Causal Agent of Grapevine Downy Mildew
Authors: Rouxel Mélanie , Papura Daciana , Nogueira Marilise , Machefer Virginie , Dezette Damien , Richard-Cervera Sylvie , Carrere Sébastien , Mestre Pere , Delmotte François 
Published: June 2012

ABSTRACT

We reported 31 microsatellite markers that have been developed from microsatellite-enriched and direct shotgun pyrosequencing libraries of
Plasmopara viticola
, the causal agent of grapevine downy mildew. These markers were optimized for population genetics applications and used to characterize 96
P. viticola
isolates from three European and three North American populations.
Identification and Characterization of Cronobacter Iron Acquisition Systems
Authors: Grim C. J. , Kothary M. H. , Gopinath G. , Jarvis K. G. , Beaubrun J. Jean-Gilles , McClelland M. , Tall B. D. , Franco A. A. 
Published: June 2012

ABSTRACT

Cronobacter
spp. are emerging pathogens that cause severe infantile meningitis, septicemia, or necrotizing enterocolitis. Contaminated powdered infant formula has been implicated as the source of
Cronobacter
spp. in most cases, but questions still remain regarding the natural habitat and virulence potential for each strain. The iron acquisition systems in 231
Cronobacter
strains isolated from different sources were identified and characterized. All
Cronobacter
spp. have both the Feo and Efe systems for acquisition of ferrous iron, and all plasmid-harboring strains (98%) have the aerobactin-like siderophore, cronobactin, for transport of ferric iron. All
Cronobacter
spp. have the genes encoding an enterobactin-like siderophore, although it was not functional under the conditions tested. Furthermore, all
Cronobacter
spp. have genes encoding five receptors for heterologous siderophores. A ferric dicitrate transport system (
fec
system) is encoded specifically by a subset of
Cronobacter sakazakii
and
C. malonaticus
strains, of which a high percentage were isolated from clinical samples. Phylogenetic analysis confirmed that the
fec
system is most closely related to orthologous genes present in human-pathogenic bacterial strains. Moreover, all strains of
C. dublinensis
and
C. muytjensii
encode two receptors, FcuA and Fct, for heterologous siderophores produced by plant pathogens. Identification of putative Fur boxes and expression of the genes under iron-depleted conditions revealed which genes and operons are components of the Fur regulon. Taken together, these results support the proposition that
C. sakazakii
and
C. malonaticus
may be more associated with the human host and
C. dublinensis
and
C. muytjensii
with plants.
Transport of Cryptosporidium parvum Oocysts in Soil Columns following Applications of Raw and Separated Liquid Slurries
Authors: Petersen Heidi H. , Enemark Heidi L. , Olsen Annette , Amin M. G. Mostofa , Dalsgaard Anders 
Published: June 2012

ABSTRACT

The potential for the transport of viable
Cryptosporidium parvum
oocysts through soil to land drains and groundwater was studied using simulated rainfall and intact soil columns which were applied raw slurry or separated liquid slurry. Following irrigation and weekly samplings over a 4-week period,
C. parvum
oocysts were detected from all soil columns regardless of slurry type and application method, although recovery rates were low (<1%). Soil columns with injected liquid slurry leached 73 and 90% more oocysts compared to columns with injected and surface-applied raw slurries, respectively. Among leachate samples containing oocysts, 44/72 samples yielded viable oocysts as determined by a dye permeability assay (DAPI [4′,6′-diamidino-2-phenylindole]/propidium iodide) with the majority (41%) of viable oocysts found in leachate from soil columns with added liquid slurry. The number of viable oocysts was positively correlated (
r
= 0.63) with the total number of oocysts found. Destructively sampling of the soil columns showed that type of slurry and irrigation played a role in the vertical distribution of oocysts, with more oocysts recovered from soil columns added liquid slurry irrespective of the irrigation status. Further studies are needed to determine the effectiveness of different slurry separation technologies to remove oocysts and other pathogens, as well as whether the application of separated liquid slurry to agricultural land may represent higher risks for groundwater contamination compared to application of raw slurry.
Defects in Mitochondrial and Peroxisomal β-Oxidation Influence Virulence in the Maize Pathogen Ustilago maydis
Authors: Kretschmer Matthias , Klose Jana , Kronstad James W. 
Published: June 2012

ABSTRACT

An understanding of metabolic adaptation during the colonization of plants by phytopathogenic fungi is critical for developing strategies to protect crops. Lipids are abundant in plant tissues, and fungal phytopathogens in the phylum basidiomycota possess both peroxisomal and mitochondrial β-oxidation pathways to utilize this potential carbon source. Previously, we demonstrated a role for the peroxisomal β-oxidation enzyme Mfe2 in the filamentous growth, virulence, and sporulation of the maize pathogen
Ustilago maydis
. However,
mfe2
mutants still caused disease symptoms, thus prompting a more detailed investigation of β-oxidation. We now demonstrate that a defect in the
had1
gene encoding hydroxyacyl coenzyme A dehydrogenase for mitochondrial β-oxidation also influences virulence, although its paralog,
had2
, makes only a minor contribution. Additionally, we identified a gene encoding a polypeptide with similarity to the C terminus of Mfe2 and designated it Mfe2b; this gene makes a contribution to virulence only in the background of an
mfe2
Δ mutant. We also show that short-chain fatty acids induce cell death in
U. maydis
and that a block in β-oxidation leads to toxicity, likely because of the accumulation of toxic intermediates. Overall, this study reveals that β-oxidation has a complex influence on the formation of disease symptoms by
U. maydis
that includes potential metabolic contributions to proliferation
in planta
and an effect on virulence-related morphogenesis.
The Schizosaccharomyces pombe
inv1
+
Regulatory Region Is Unusually Large and Contains Redundant
cis
-Acting Elements That Function in a SAGA- and Swi/Snf-Dependent Fashion
Authors: Ahn Sejin , Spatt Dan , Winston Fred 
Published: June 2012

ABSTRACT

The
Schizosaccharomyces pombe
inv1
+
gene encodes invertase, the enzyme required for hydrolysis of sucrose and raffinose. Transcription of
inv1

+

is regulated by glucose levels, with transcription tightly repressed in high glucose and strongly induced in low glucose. To understand this regulation, we have analyzed the
inv1
+
cis
-regulatory region and the requirement for the
trans
-acting coactivators SAGA and Swi/Snf. Surprisingly, deletion of the entire 1-kilobase intergenic region between the
inv1

+

TATA element and the upstream open reading frame SPCC191.10 does not significantly alter regulation of
inv1

+

transcription. However, a longer deletion that extends through SPCC191.10 abolishes
inv1

+

induction in low glucose. Additional analysis demonstrates that there are multiple, redundant regulatory regions spread over 1.5 kb 5′ of
inv1

+

, including within SPCC191.10, that can confer glucose-mediated transcriptional regulation to
inv1

+

. Furthermore, SPCC191.10 can regulate
inv1

+

transcription in an orientation-independent fashion and from a distance as great as 3 kb. With respect to
trans
-acting factors, both SAGA and Swi/Snf are recruited to SPCC191.10 and to other locations in the large
inv1

+

regulatory region in a glucose-dependent fashion, and both are required for
inv1

+

derepression. Taken together, these results demonstrate that
inv1

+

regulation in
S. pombe
occurs via the use of multiple regulatory elements and that activation can occur over a great distance, even from elements within other open reading frames.
YknWXYZ Is an Unusual Four-Component Transporter with a Role in Protection against Sporulation-Delaying-Protein-Induced Killing of Bacillus subtilis
Authors: Yamada Yoichi , Tikhonova Elena B. , Zgurskaya Helen I. 
Published: June 2012

ABSTRACT

YknXYZ is the ATP-binding cassette export complex from
Bacillus subtilis
, where YknX is a membrane fusion protein, YknY is an ATPase, and YknZ is a permease. The
yknXYZ
genes are arranged into an operon that also includes
yknW
, encoding a membrane protein with four putative transmembrane segments. Previous studies suggested that the
yknWXYZ
operon belongs to the σ
w
regulon and protects cells from the endogenous toxin SDP (sporulation-delaying protein) encoded by
sdpC
. In this study, we investigated the composition and function of YknW and YknXYZ. We report that the
yknWXYZ
operon is constitutively expressed in growing
B. subtilis
cells independently from
sdpC
. Chemical cross-linking
in vivo
and copurification approaches established that YknX interacts with YknYZ, whereas YknW binds YknXYZ, indicating that all four proteins form a complex
in vivo
. The complex assembly is modulated by YknW but proceeds in the absence of SdpC. When overproduced alone, YknW provides partial protection against SDP toxin, but all four Ykn proteins are required for full protection against both endogenous and exogenous SDP. We conclude that YknWXYZ is an unusual four-component transporter with a role in the starvation-induced killing of
B. subtilis
cells.
Analysis of IS
1236
-Mediated Gene Amplification Events in Acinetobacter baylyi ADP1
Authors: Cuff Laura E. , Elliott Kathryn T. , Seaton Sarah C. , Ishaq Maliha K. , Laniohan Nicole S. , Karls Anna C. , Neidle Ellen L. 
Published: June 2012

ABSTRACT

Recombination between insertion sequence copies can cause genetic deletion, inversion, or duplication. However, it is difficult to assess the fraction of all genomic rearrangements that involve insertion sequences. In previous gene duplication and amplification studies of
Acinetobacter baylyi
ADP1, an insertion sequence was evident in approximately 2% of the characterized duplication sites. Gene amplification occurs frequently in all organisms and has a significant impact on evolution, adaptation, drug resistance, cancer, and various disorders. To understand the molecular details of this important process, a previously developed system was used to analyze gene amplification in selected mutants. The current study focused on amplification events in two chromosomal regions that are near one of six copies of the only transposable element in ADP1, IS
1236
(an IS
3
family member). Twenty-one independent mutants were analyzed, and in contrast to previous studies of a different chromosomal region, IS
1236
was involved in 86% of these events. IS
1236
-mediated amplification could occur through homologous recombination between insertion sequences on both sides of a duplicated region. However, this mechanism presupposes that transposition generates an appropriately positioned additional copy of IS
1236
. To evaluate this possibility, PCR and Southern hybridization were used to determine the chromosomal configurations of amplification mutants involving IS
1236
. Surprisingly, the genomic patterns were inconsistent with the hypothesis that intramolecular homologous recombination occurred between insertion sequences following an initial transposition event. These results raise a novel possibility that the gene amplification events near the IS
1236
elements arise from illegitimate recombination involving transposase-mediated DNA cleavage.
A multicentre observational study to evaluate a new tool to assess emergency physicians' non-technical skills
Authors: Flowerdew Lynsey , Gaunt Arran , Spedding Jessica , Bhargava Ajay , Brown Ruth , Vincent Charles , Woloshynowych Maria 
Published: June 2012

ObjectiveTo evaluate a new tool to assess emergency physicians' non-technical skills.MethodsThis was a multicentre observational study using data collected at four emergency departments in England. A proportion of observations used paired observers to obtain data for inter-rater reliability. Data were also collected for test-retest reliability, observability of skills, mean ratings and dispersion of ratings for each skill, as well as a comparison of skill level between hospitals. Qualitative data described the range of non-technical skills exhibited by trainees and identified sources of rater error.Results96 assessments of 43 senior trainees were completed. At a scale level, intra-class coefficients were 0.575, 0.532 and 0.419 and using mean scores were 0.824, 0.702 and 0.519. Spearman's ρ for calculating test-retest reliability was 0.70 using mean scores. All skills were observed more than 60% of the time. The skill Maintenance of Standards received the lowest mean rating (4.8 on a nine-point scale) and the highest mean was calculated for Team Building (6.0). Two skills, Supervision & Feedback and Situational Awareness-Gathering Information, had significantly different distributions of ratings across the four hospitals (p<0.04 and 0.007, respectively), and this appeared to be related to the leadership roles of trainees.ConclusionThis study shows the performance of the assessment tool is acceptable and provides valuable information to structure the assessment and training of non-technical skills, especially in relation to leadership. The framework of skills may be used to identify areas for development in individual trainees, as well as guide other patient safety interventions.