bluuebunny/crossref_metadata_2025_split huggingface dataset:
Differential calcium sensitivity in NaV1.5 mixed syndrome mutants
Authors: Abdelsayed Mena , Baruteau Alban‐Elouen , Gibbs Karen , Sanatani Shubhayan , Krahn Andrew D. , Probst Vincent , Ruben Peter C. 
Published: July 2017

Key points
SCN5a mutations may express gain‐of‐function (Long QT Syndrome‐3), loss‐of‐function (Brugada Syndrome 1) or both (mixed syndromes), depending on the mutation and environmental triggers. One such trigger may be an increase in cytosolic calcium, accompanying exercise.
Many mixed syndromes mutants, including ∆KPQ, E1784K, 1795insD and Q1909R, are found in calcium‐sensitive regions.
Elevated cytosolic calcium attenuates gain‐of‐function properties in ∆KPQ, 1795insD and Q1909R, but not in E1784K. By contrast, elevated cytosolic calcium further exacerbates gain‐of‐function in E1784K by destabilizing slow inactivation.
Action potential modelling, using a modified O'Hara Rudy model, suggests that elevated heart rate rescues action potential duration in ∆KPQ, 1795insD and Q1909R, but not in E1784K.
Action potential simulations suggest that E1784K carriers have an increased intracellular sodium‐to‐calcium ratio under bradycardia and tachycardia conditions.
Elevated cytosolic calcium, which is common during high heart rates, ameliorates or exacerbates the mixed syndrome phenotype depending on the genetic signature.
AbstractInherited arrhythmias may arise from mutations in the gene for SCN5a, which encodes the cardiac voltage‐gated sodium channel, NaV1.5. Mutants in NaV1.5 result in Brugada Syndrome (BrS1), Long‐QT Syndrome (LQT3) or mixed syndromes (an overlap of BrS1/LQT3). Exercise is a potential arrhythmogenic trigger in mixed syndromes. We aimed to determine the effects of elevated cytosolic calcium, which is common during exercise, in mixed syndrome NaV1.5 mutants. We used whole‐cell patch clamp to assess the biophysical properties of NaV1.5 wild‐type (WT), ∆KPQ, E1784K, 1795insD and Q1909R mutants in human embryonic kidney 293 cells transiently transfected with the NaV1.5 α subunit (WT or mutants), β1 subunit and enhanced green fluorescent protein. Voltage‐dependence and kinetics were measured at cytosolic calcium levels of approximately 0, 500 and 2500 nm. In silico, action potential (AP) model simulations were performed using a modified O'Hara Rudy model. Elevated cytosolic calcium attenuates the late sodium current in ∆KPQ, 1795insD and Q1909R, but not in E1784K. Elevated cytosolic calcium restores steady‐state slow inactivation (SSSI) to the WT‐form in Q1909R, but depolarized SSSI in E1784K. Our AP simulations showed a frequency‐dependent reduction of AP duration in ∆KPQ, 1795insD and Q1909R carriers. In E1784K, AP duration is relatively prolonged at both low and high heart rates, resulting in a sodium overload. Cellular perturbations during exercise may affect BrS1/LQT3 patients differently depending on their individual genetic signature. Thus, exercise may be therapeutic or may be an arrhythmogenic trigger in some SCN5a patients.
Advanced Ultrasonic In-Line Inspection for the Assessment of Pipelines Affected by Pitting and Pinhole Corrosion
Authors: Willems Herbert 
Published: July 2017

The network of pipelines worldwide is growing and aging which leads to an ever increasing focus towards integrity management of these pipelines. One major challenge faced by today’s operators is the realization and management of corrosion of pipelines. Unless detected, sized and documented correctly corrosion does pose as a major time-dependent threat to the aging pipeline network which eventually, if undetected and uncontrolled, can lead to catastrophic failures.
Inline inspection (ILI) by means of intelligent pigs is widely used to ensure a safe operation of pipelines. Ultrasonic technology (UT) is currently the most accurate and reliable inline inspection technology available in the market. Highly specialized UT ILI tools can detect and size pipeline threats related to corrosion or cracking. High resolution tools as available today allow for the reliable inspection of tiny corrosion defects such as pittings or even pinholes. These small but often deep anomalies are severe forms of corrosion known to have caused pipeline failures in the past.
The economic environment for oil companies has changed significantly in the last few years where reduced prices and margins for oil transportation and production challenge pipeline operators globally. At these tight margins, operators must scrutinize closely the indirect costs of performing inspections. Any constraints imposed by required inspections have the potential to negatively affect margin, including the reduction of pipeline flow rates to accommodate optimum inline inspection conditions. The latest generation of UT tools offer higher inspection speeds which overcome the need for flow reduction, therefore reducing transportation losses due to the reduction of throughput. In addition, there is also a need for enhanced axial and circumferential resolution to enable reliable detection and sizing of e. g. pinhole corrosion defects. Without the necessary measuring resolution these defects otherwise might go undetected and un-accounted for. In this contribution, the latest improvements of ultrasonic ILI are described and illustrated by inspection results.
Risk Based Inspection (RBI) Implementation in Cross Country Petroleum Pipelines
Authors: Singh Gurjar Sahab 
Published: July 2017

Risk Based Inspection (RBI) is a risk assessment and management process that is focused on loss of containment of pressurized equipment in processing / transportation facilities, due to material deterioration / degradation. These risks are managed primarily through threat identification, inspection, monitoring and mitigation measures. Risk Based Inspection (RBI) process is focused on maintaining the mechanical integrity of high pressure pipelines and minimizing the risk of loss of containment due to deterioration. Frequency of inspection & monitoring activities are fixed in cost effective way which based on the risk ranking.
This paper discusses the development, implementation and maintaining a risk-based inspection (RBI) program for high pressure long petroleum pipelines. It provides guidance to operators of pressure-containing pipelines for developing and implementing an inspection program. This technical paper includes means for assessing an inspection program and its plan. The approach emphasizes safe and reliable operation through risk-prioritized inspection and monitoring program. This also includes practical implementation case study of Wolrd’s longest heated crude oil pipeline operated and maintained by M/s Cairn India Limited.
Effect of Rifampin on the Single-Dose Pharmacokinetics of Oral Cabotegravir in Healthy Subjects
Authors: Ford S. L. , Sutton K. , Lou Y. , Zhang Z. , Tenorio A. , Trezza C. , Patel P. , Spreen W. 
Published: July 2017

ABSTRACT
Drug-drug interactions between antiretroviral medications and rifampin complicate the treatment of HIV and tuberculosis coinfection. This study evaluated the effect of rifampin on the pharmacokinetics of oral cabotegravir, an integrase strand transfer inhibitor being investigated for long-acting treatment and prevention of HIV-1 infection. This was a phase I, single-center, open-label, fixed-sequence crossover study in healthy adults. The objective was to evaluate the effect of steady-state rifampin on the single-dose plasma pharmacokinetics of cabotegravir. Subjects received a single oral dose of cabotegravir (30 mg) on day 1 followed by plasma sampling on days 1 to 8. Treatment with once-daily oral rifampin (600 mg) occurred on days 8 to 28. Subjects received a second dose of 30 mg cabotegravir on day 21 followed by pharmacokinetic sampling on days 21 to 28. Fifteen subjects were enrolled and completed the study. Rifampin decreased the cabotegravir area under the concentration-time curve from 0 h to infinity and the half-life by 59% and 57%, respectively, whereas oral clearance was increased 2.4-fold. The maximum concentration of cabotegravir in plasma was unaffected by coadministration with rifampin. All adverse events were mild in severity, with chromaturia attributed to rifampin observed in all subjects. Rifampin induction of cabotegravir metabolism resulted in increased cabotegravir oral clearance and significantly decreased cabotegravir exposures. Rifampin is expected to increase cabotegravir clearance following long-acting injectable administration. Concomitant administration of rifampin with oral and long-acting formulations of cabotegravir is not recommended currently without further study. (This study has been registered at ClinicalTrials.gov under registration no. NCT02411435.)
Protection of Hamsters from Mortality by Reducing Fecal Moxifloxacin Concentration with DAV131A in a Model of Moxifloxacin-Induced Clostridium difficile Colitis
Authors: Burdet Charles , Sayah-Jeanne Sakina , Nguyen Thu Thuy , Miossec Christine , Saint-Lu Nathalie , Pulse Mark , Weiss William , Andremont Antoine , Mentré France , de Gunzburg Jean 
Published: July 2017

ABSTRACT

Lowering the gut exposure to antibiotics during treatments can prevent microbiota disruption. We evaluated the effects of an activated charcoal-based adsorbent, DAV131A, on the fecal free moxifloxacin concentration and mortality in a hamster model of moxifloxacin-induced
Clostridium difficile
infection. A total of 215 hamsters receiving moxifloxacin subcutaneously (day 1 [D
1
] to D
5
) were orally infected at D
3
with
C. difficile
spores. They received various doses (0 to 1,800 mg/kg of body weight/day) and schedules (twice a day [BID] or three times a day [TID]) of DAV131A (D
1
to D
8
). Moxifloxacin concentrations and
C. difficile
counts were determined at D
3
, and mortality was determined at D
12
. We compared mortality rates, moxifloxacin concentrations, and
C. difficile
counts according to DAV131A regimen and modeled the links between DAV131A regimen, moxifloxacin concentration, and mortality. All hamsters that received no DAV131A died, but none of those that received 1,800 mg/kg/day died. Significant dose-dependent relationships between DAV131A dose and (i) mortality, (ii) moxifloxacin concentration, and (iii)
C. difficile
count were evidenced. Mathematical modeling suggested that (i) lowering the moxifloxacin concentration at D
3
, which was 58 μg/g (95% confidence interval [CI] = 50 to 66 μg/g) without DAV131A, to 17 μg/g (14 to 21 μg/g) would reduce mortality by 90%; and (ii) this would be achieved with a daily DAV131A dose of 703 mg/kg (596 to 809 mg/kg). In this model of
C. difficile
infection, DAV131A reduced mortality in a dose-dependent manner by decreasing the fecal free moxifloxacin concentration.
Differentiating Botulinum Neurotoxin-Producing Clostridia with a Simple, Multiplex PCR Assay
Authors: Williamson Charles H. D. , Vazquez Adam J. , Hill Karen , Smith Theresa J. , Nottingham Roxanne , Stone Nathan E. , Sobek Colin J. , Cocking Jill H. , Fernández Rafael A. , Caballero Patricia A. , Leiser Owen P. , Keim Paul , Sahl Jason W. 
Published: July 2017

ABSTRACT

Diverse members of the genus
Clostridium
produce botulinum neurotoxins (BoNTs), which cause a flaccid paralysis known as botulism. While multiple species of clostridia produce BoNTs, the majority of human botulism cases have been attributed to
Clostridium botulinum
groups I and II. Recent comparative genomic studies have demonstrated the genomic diversity within these BoNT-producing species. This report introduces a multiplex PCR assay for differentiating members of
C. botulinum
group I,
C. sporogenes
, and two major subgroups within
C. botulinum
group II. Coding region sequences unique to each of the four species/subgroups were identified by
in silico
analyses of thousands of genome assemblies, and PCR primers were designed to amplify each marker. The resulting multiplex PCR assay correctly assigned 41 tested isolates to the appropriate species or subgroup. A separate PCR assay to determine the presence of the
ntnh
gene (a gene associated with the botulinum neurotoxin gene cluster) was developed and validated. The
ntnh
gene PCR assay provides information about the presence or absence of the botulinum neurotoxin gene cluster and the type of gene cluster present (
ha
positive [
ha
+
] or
orfX
+
). The increased availability of whole-genome sequence data and comparative genomic tools enabled the design of these assays, which provide valuable information for characterizing BoNT-producing clostridia. The PCR assays are rapid, inexpensive tests that can be applied to a variety of sample types to assign isolates to species/subgroups and to detect clostridia with botulinum neurotoxin gene (
bont
) clusters.

IMPORTANCE
Diverse clostridia produce the botulinum neurotoxin, one of the most potent known neurotoxins. In this study, a multiplex PCR assay was developed to differentiate clostridia that are most commonly isolated in connection with human botulism cases:
C. botulinum
group I,
C. sporogenes
, and two major subgroups within
C. botulinum
group II. Since BoNT-producing and nontoxigenic isolates can be found in each species, a PCR assay to determine the presence of the
ntnh
gene, which is a universally present component of
bont
gene clusters, and to provide information about the type (
ha
+
or
orfX
+
) of
bont
gene cluster present in a sample was also developed. The PCR assays provide simple, rapid, and inexpensive tools for screening uncharacterized isolates from clinical or environmental samples. The information provided by these assays can inform epidemiological studies, aid with identifying mixtures of isolates and unknown isolates in culture collections, and confirm the presence of bacteria of interest.
Identification of the
hcb
Gene Operon Involved in Catalyzing Aerobic Hexachlorobenzene Dechlorination in Nocardioides sp. Strain PD653
Authors: Ito Koji , Takagi Kazuhiro , Iwasaki Akio , Tanaka Naoto , Kanesaki Yu , Martin-Laurent Fabrice , Igimi Shizunobu 
Published: July 2017

ABSTRACT

Nocardioides
sp. strain PD653 was the first identified aerobic bacterium capable of mineralizing hexachlorobenzene (HCB). In this study, strain PD653-B2, which was unexpectedly isolated from a subculture of strain PD653, was found to lack the ability to transform HCB or pentachloronitrobenzene into pentachlorophenol. Comparative genome analysis of the two strains revealed that genetic rearrangement had occurred in strain PD653-B2, with a genomic region present in strain PD653 being deleted.
In silico
analysis allowed three open reading frames within this region to be identified as candidate genes involved in HCB dechlorination. Assays using recombinant
Escherichia coli
cells revealed that an operon is responsible for both oxidative HCB dechlorination and pentachloronitrobenzene denitration. The metabolite pentachlorophenol was detected in the cultures produced in the
E. coli
assays. Significantly less HCB-degrading activity occurred in assays under oxygen-limited conditions ([O
2
] < 0.5 mg liter
−1
) than under aerobic assays, suggesting that monooxygenase is involved in the reaction. In this operon,
hcbA1
was found to encode a monooxygenase involved in HCB dechlorination. This monooxygenase may form a complex with the flavin reductase encoded by
hcbA3
, increasing the HCB-degrading activity of PD653.

IMPORTANCE
The organochlorine fungicide HCB is widely distributed in the environment. Bioremediation can effectively remove HCB from contaminated sites, but HCB-degrading microorganisms have been isolated in few studies and the genes involved in HCB degradation have not been identified. In this study, possible genes involved in the initial step of the mineralization of HCB by
Nocardioides
sp. strain PD653 were identified. The results improve our understanding of the protein families involved in the dechlorination of HCB to give pentachlorophenol.
An Enterotoxin-Like Binary Protein from Pseudomonas protegens with Potent Nematicidal Activity
Authors: Wei Jun-Zhi , Siehl Daniel L. , Hou Zhenglin , Rosen Barbara , Oral Jarred , Taylor Christopher G. , Wu Gusui 
Published: July 2017

ABSTRACT

Soil microbes are a major food source for free-living soil nematodes. It is known that certain soil bacteria have evolved systems to combat predation. We identified the nematode-antagonistic
Pseudomonas protegens
strain 15G2 from screening of microbes. Through protein purification we identified a binary protein, designated Pp-ANP, which is responsible for the nematicidal activity. This binary protein inhibits
Caenorhabditis elegans
growth and development by arresting larvae at the L1 stage and killing older-staged worms. The two subunits, Pp-ANP1a and Pp-ANP2a, are active when reconstituted from separate expression in
Escherichia coli
. The binary toxin also shows strong nematicidal activity against three other free-living nematodes (
Pristionchus pacificus
,
Panagrellus redivivus
, and
Acrobeloides
sp.), but we did not find any activity against insects and fungi under test conditions, indicating specificity for nematodes. Pp-ANP1a has no significant identity to any known proteins, while Pp-ANP2a shows ∼30% identity to
E. coli
heat-labile enterotoxin (LT) subunit A and cholera toxin (CT) subunit A. Protein modeling indicates that Pp-ANP2a is structurally similar to CT/LT and likely acts as an ADP-ribosyltransferase. Despite the similarity, Pp-ANP shows several characteristics distinct from CT/LT toxins. Our results indicate that Pp-ANP is a new enterotoxin-like binary toxin with potent and specific activity to nematodes. The potency and specificity of Pp-ANP suggest applications in controlling parasitic nematodes and open an avenue for further research on its mechanism of action and role in bacterium-nematode interaction.

IMPORTANCE
This study reports the discovery of a new enterotoxin-like binary protein, Pp-ANP, from a
Pseudomonas protegens
strain. Pp-ANP shows strong nematicidal activity against
Caenorhabditis elegans
larvae and older-staged worms. It also shows strong activity on other free-living nematodes (
Pristionchus pacificus
,
Panagrellus redivivus
, and
Acrobeloides
sp.). The two subunits, Pp-ANP1a and Pp-ANP2a, can be expressed separately and reconstituted to form the active complex. Pp-ANP shows some distinct characteristics compared with other toxins, including
Escherichia coli
enterotoxin and cholera toxin. The present study indicates that Pp-ANP is a novel binary toxin and that it has potential applications in controlling parasitic nematodes and in studying toxin-host interaction.
Bacillomycin D Produced by Bacillus amyloliquefaciens Is Involved in the Antagonistic Interaction with the Plant-Pathogenic Fungus Fusarium graminearum
Authors: Gu Qin , Yang Yang , Yuan Qiming , Shi Guangming , Wu Liming , Lou Zhiying , Huo Rong , Wu Huijun , Borriss Rainer , Gao Xuewen 
Published: July 2017

ABSTRACT

Fusarium graminearum
(teleomorph: Ascomycota, Hypocreales,
Gibberella
,
Gibberella zeae
) is a destructive fungal pathogen that threatens the production and quality of wheat and barley worldwide. Controlling this toxin-producing pathogen is a significant challenge. In the present study, the commercially available strain
Bacillus amyloliquefaciens
(
Bacteria
,
Firmicutes
,
Bacillales
,
Bacillus
) FZB42 showed strong activity against
F. graminearum
. The lipopeptide bacillomycin D, produced by FZB42, was shown to contribute to the antifungal activity. Purified bacillomycin D showed strong activity against
F. graminearum
, and its 50% effective concentration was determined to be approximately 30 μg/ml. Analyses using scanning and transmission electron microscopy revealed that bacillomycin D caused morphological changes in the plasma membranes and cell walls of
F. graminearum
hyphae and conidia. Fluorescence microscopy combined with different dyes showed that bacillomycin D induced the accumulation of reactive oxygen species and caused cell death in
F. graminearum
hyphae and conidia.
F. graminearum
secondary metabolism also responded to bacillomycin D challenge, by increasing the production of deoxynivalenol. Biological control experiments demonstrated that bacillomycin D exerted good control of
F. graminearum
on corn silks, wheat seedlings, and wheat heads. In response to bacillomycin D,
F. graminearum
genes involved in scavenging reactive oxygen species were downregulated, whereas genes involved in the synthesis of deoxynivalenol were upregulated. Phosphorylation of MGV1 and HOG1, the mitogen-activated protein kinases of
F. graminearum
, was increased in response to bacillomycin D. Taken together, these findings reveal the mechanism of the antifungal action of bacillomycin D.

IMPORTANCE
Biological control of plant disease caused by
Fusarium graminearum
is desirable.
Bacillus amyloliquefaciens
FZB42 is a representative of the biocontrol bacterial strains. In this work, the lipopeptide bacillomycin D, produced by FZB42, showed strong fungicidal activity against
F. graminearum
. Bacillomycin D caused morphological changes in the plasma membrane and cell wall of
F. graminearum
, induced accumulation of reactive oxygen species, and ultimately caused cell death in
F. graminearum
. Interestingly, when
F. graminearum
was challenged with bacillomycin D, the deoxynivalenol production, gene expression, mitogen-activated protein kinase phosphorylation, and pathogenicity of
F. graminearum
were significantly altered. These findings clarified the mechanisms of the activity of bacillomycin D against
F. graminearum
and highlighted the potential of
B. amyloliquefaciens
FZB42 as a biocontrol agent against
F. graminearum
.
Transcriptional Modulation of Transport- and Metabolism-Associated Gene Clusters Leading to Utilization of Benzoate in Preference to Glucose in Pseudomonas putida CSV86
Authors: Choudhary Alpa , Modak Arnab , Apte Shree K. , Phale Prashant S. 
Published: July 2017

ABSTRACT

The effective elimination of xenobiotic pollutants from the environment can be achieved by efficient degradation by microorganisms even in the presence of sugars or organic acids. Soil isolate
Pseudomonas putida
CSV86 displays a unique ability to utilize aromatic compounds prior to glucose. The draft genome and transcription analyses revealed that glucose uptake and benzoate transport and metabolism genes are clustered at the
glc
and
ben
loci, respectively, as two distinct operons. When grown on glucose plus benzoate, CSV86 displayed significantly higher expression of the
ben
locus in the first log phase and of the
glc
locus in the second log phase. Kinetics of substrate uptake and metabolism matched the transcription profiles. The inability of succinate to suppress benzoate transport and metabolism resulted in coutilization of succinate and benzoate. When challenged with succinate or benzoate, glucose-grown cells showed rapid reduction in
glc
locus transcription, glucose transport, and metabolic activity, with succinate being more effective at the functional level. Benzoate and succinate failed to interact with or inhibit the activities of glucose transport components or metabolic enzymes. The data suggest that succinate and benzoate suppress glucose transport and metabolism at the transcription level, enabling
P. putida
CSV86 to preferentially metabolize benzoate. This strain thus has the potential to be an ideal host to engineer diverse metabolic pathways for efficient bioremediation.

IMPORTANCE
Pseudomonas
strains play an important role in carbon cycling in the environment and display a hierarchy in carbon utilization: organic acids first, followed by glucose, and aromatic substrates last. This limits their exploitation for bioremediation. This study demonstrates the substrate-dependent modulation of
ben
and
glc
operons in
Pseudomonas putida
CSV86, wherein benzoate suppresses glucose transport and metabolism at the transcription level, leading to preferential utilization of benzoate over glucose. Interestingly, succinate and benzoate are cometabolized. These properties are unique to this strain compared to other pseudomonads and open up avenues to unravel novel regulatory processes. Strain CSV86 can serve as an ideal host to engineer and facilitate efficient removal of recalcitrant pollutants even in the presence of simpler carbon sources.