bluuebunny/crossref_metadata_2025 huggingface dataset:
The RpoE Stress Response Pathway Mediates Reduction of the Virulence of Enteropathogenic Escherichia coli by Zinc
Authors: Xue Yuan , Osborn Jossef , Panchal Anand , Mellies Jay L.
Published: March 2015

Zinc supplements are an effective clinical treatment for infantile diarrheal disease caused by enteric pathogens. Previous studies demonstrated that zinc acts on enteropathogenic
Escherichia coli
(EPEC) bacteria directly to suppress several virulence-related genes at a concentration that can be achieved by oral delivery of dietary zinc supplements. Our
in vitro
studies showed that a micromolar concentration of zinc induced the envelope stress response and suppressed virulence in EPEC, providing a possible mechanistic explanation for zinc's therapeutic action. In this report, we investigated the molecular and physiological changes in EPEC induced by zinc. We found that micromolar concentrations of zinc reduced the bacterial growth rate without affecting viability. We observed increased membrane permeability caused by zinc. Zinc upregulated the RpoE-dependent envelope stress response pathway and suppressed EPEC virulence gene expression. RpoE alone was sufficient to inhibit virulence factor expression and to attenuate attaching and effacing lesion formation on human host cells. By mutational analysis we demonstrate that the DNA-binding motif of RpoE is necessary for suppression of the
LEE1
, but not the
LEE4
, operon. Predictably, inhibition of the RpoE-mediated envelope stress response in combination with micromolar concentrations of zinc reduced EPEC viability. In conclusion, zinc induces the RpoE and stress response pathways in EPEC, and the alternate sigma factor RpoE downregulates EPEC LEE and non-LEE virulence genes by multiple mechanisms.
Carbon Source Preference in Chemosynthetic Hot Spring Communities
Authors: Urschel Matthew R. , Kubo Michael D. , Hoehler Tori M. , Peters John W. , Boyd Eric S.
Published: March 2015

Rates of dissolved inorganic carbon (DIC), formate, and acetate mineralization and/or assimilation were determined in 13 high-temperature (>73°C) hot springs in Yellowstone National Park (YNP), Wyoming, in order to evaluate the relative importance of these substrates in supporting microbial metabolism. While 9 of the hot spring communities exhibited rates of DIC assimilation that were greater than those of formate and acetate assimilation, 2 exhibited rates of formate and/or acetate assimilation that exceeded those of DIC assimilation. Overall rates of DIC, formate, and acetate mineralization and assimilation were positively correlated with spring pH but showed little correlation with temperature. Communities sampled from hot springs with similar geochemistries generally exhibited similar rates of substrate transformation, as well as similar community compositions, as revealed by 16S rRNA gene-tagged sequencing. Amendment of microcosms with small (micromolar) amounts of formate suppressed DIC assimilation in short-term (<45-min) incubations, despite the presence of native DIC concentrations that exceeded those of added formate by 2 to 3 orders of magnitude. The concentration of added formate required to suppress DIC assimilation was similar to the affinity constant (

K
m

) for formate transformation, as determined by community kinetic assays. These results suggest that dominant chemoautotrophs in high-temperature communities are facultatively autotrophic or mixotrophic, are adapted to fluctuating nutrient availabilities, and are capable of taking advantage of energy-rich organic substrates when they become available.
“Quorum Non-Sensing”: Social Cheating and Deception in Vibrio cholerae
Authors: Katzianer David S. , Wang Hui , Carey Ryan M. , Zhu Jun
Published: March 2015

Quorum sensing (QS) is widely used by bacteria to coordinate behavior in response to external stimuli. In
Vibrio cholerae
, this process is important for environmental survival and pathogenesis, though, intriguingly, a large percentage of natural isolates are QS deficient. Here, we show that QS-deficient mutants can spread as social cheaters by ceasing production of extracellular proteases under conditions requiring their growth. We further show that mutants stimulate biofilm formation and are over-represented in biofilms compared to planktonic communities; on this basis, we suggest that QS-deficient mutants may have the side effect of enhancing environmental tolerance of natural populations due to the inherent resistance properties of biofilms. Interestingly, high frequencies of QS-deficient individuals did not impact production of QS signaling molecules despite mutants being unable to respond to these inducers, indicating that these variants actively cheat by false signaling under conditions requiring QS. Taken together, our results suggest that social cheating may drive QS deficiency emergence within
V. cholerae
natural populations.
Alamethicin Suppresses Methanogenesis and Promotes Acetogenesis in Bioelectrochemical Systems
Authors: Zhu Xiuping , Siegert Michael , Yates Matthew D. , Logan Bruce E.
Published: March 2015

Microbial electrosynthesis (MES) systems with mixed cultures often generate a variety of gaseous and soluble chemicals. Methane is the primary end product in mixed-culture MES because it is the thermodynamically most favorable reduction product of CO
2
. Here, we show that the peptaibol alamethicin selectively suppressed the growth of methanogens in mixed-culture MES systems, resulting in a shift of the solution and cathode communities to an acetate-producing system dominated by
Sporomusa
, a known acetogenic genus in MES systems.
Archaea
in the methane-producing control were dominated by
Methanobrevibacter
species, but no
Archaea
were detected in the alamethicin-treated reactors. No methane was detected in the mixed-culture reactors treated with alamethicin over 10 cycles (∼3 days each). Instead, acetate was produced at an average rate of 115 nmol ml
−1
day
−1
, similar to the rate reported previously for pure cultures of
Sporomusa ovata
on biocathodes. Mixed-culture control reactors without alamethicin generated methane at nearly 100% coulombic recovery, and no acetate was detected. These results show that alamethicin is effective for the suppression of methanogen growth in MES systems and that its use enables the production of industrially relevant organic compounds by the inhibition of methanogenesis.
Evaluation of Molecular Methods To Improve the Detection of Burkholderia pseudomallei in Soil and Water Samples from Laos
Authors: Knappik Michael , Dance David A. B. , Rattanavong Sayaphet , Pierret Alain , Ribolzi Olivier , Davong Viengmon , Silisouk Joy , Vongsouvath Manivanh , Newton Paul N. , Dittrich Sabine
Published: March 2015

Burkholderia pseudomallei
is the cause of melioidosis, a severe and potentially fatal disease of humans and animals. It is endemic in northern Australia and Southeast Asia and is found in soil and surface water. The environmental distribution of
B. pseudomallei
worldwide and within countries where it is endemic, such as the Lao People's Democratic Republic (Laos), remains unclear. However, this knowledge is important to our understanding of the ecology and epidemiology of
B. pseudomallei
and to facilitate public health interventions. Sensitive and specific methods to detect
B. pseudomallei
in environmental samples are therefore needed. The aim of this study was to compare molecular and culture-based methods for the detection of
B. pseudomallei
in soil and surface water in order to identify the optimal approach for future environmental studies in Laos. Molecular detection by quantitative real-time PCR (qPCR) was attempted after DNA extraction directly from soil or water samples or after an overnight enrichment step. The positivity rates obtained by qPCR were compared to those obtained by different culture techniques. The rate of detection from soil samples by qPCR following culture enrichment was significantly higher (84/100) than that by individual culture methods and all culture methods combined (44/100;
P
< 0.001). Similarly, qPCR following enrichment was the most sensitive method for filtered river water compared with the sensitivity of the individual methods and all individual methods combined. In conclusion, molecular detection following an enrichment step has proven to be a sensitive and reliable approach for
B. pseudomallei
detection in Lao environmental samples and is recommended as the preferred method for future surveys.
Lincomycin at Subinhibitory Concentrations Potentiates Secondary Metabolite Production by Streptomyces spp
Authors: Imai Yu , Sato Seizo , Tanaka Yukinori , Ochi Kozo , Hosaka Takeshi
Published: March 2015

Antibiotics have either bactericidal or bacteriostatic activity. However, they also induce considerable gene expression in bacteria when used at subinhibitory concentrations (below the MIC). We found that lincomycin, which inhibits protein synthesis by binding to the ribosomes of Gram-positive bacteria, was effective for inducing the expression of genes involved in secondary metabolism in
Streptomyces
strains when added to medium at subinhibitory concentrations. In
Streptomyces coelicolor
A3(2), lincomycin at 1/10 of its MIC markedly increased the expression of the pathway-specific regulatory gene
act
II-ORF4 in the blue-pigmented antibiotic actinorhodin (ACT) biosynthetic gene cluster, which resulted in ACT overproduction. Intriguingly,
S. lividans
1326 grown in the presence of lincomycin at a subinhibitory concentration (1/12 or 1/3 of its MIC) produced abundant antibacterial compounds that were not detected in cells grown in lincomycin-free medium. Bioassay and mass spectrometry analysis revealed that some antibacterial compounds were novel congeners of calcium-dependent antibiotics. Our results indicate that lincomycin at subinhibitory concentrations potentiates the production of secondary metabolites in
Streptomyces
strains and suggest that activating these strains by utilizing the dose-response effects of lincomycin could be used to effectively induce the production of cryptic secondary metabolites. In addition to these findings, we also report that lincomycin used at concentrations for markedly increased ACT production resulted in alteration of the cytoplasmic protein (F
o
F
1
ATP synthase α and β subunits, etc.) profile and increased intracellular ATP levels. A fundamental mechanism for these unique phenomena is also discussed.
Role of Pex11p in Lipid Homeostasis in Yarrowia lipolytica
Authors: Dulermo Rémi , Dulermo Thierry , Gamboa-Meléndez Heber , Thevenieau France , Nicaud Jean-Marc
Published: March 2015

Peroxisomes are essential organelles in the cells of most eukaryotes, from yeasts to mammals. Their role in β-oxidation is particularly essential in yeasts; for example, in
Saccharomyces cerevisiae
, fatty acid oxidation takes place solely in peroxisomes. In this species, peroxisome biogenesis occurs when lipids are present in the culture medium, and it involves the Pex11p protein family: ScPex11p, ScPex25p, ScPex27p, and ScPex34p.
Yarrowia lipolytica
has three Pex11p homologues, which are YALI0C04092p (YlPex11p), YALI0C04565p (YlPex11C), and YALI0D25498p (Pex11/25p). We found that these genes are regulated by oleic acid, and as has been observed in other organisms,
YlPEX11
deletion generated giant peroxisomes when mutant yeast were grown in oleic acid medium. Moreover, Δ
Ylpex11
was unable to grow on fatty acid medium and showed extreme dose-dependent sensitivity to oleic acid. Indeed, when the strain was grown in minimum medium with 0.5% glucose and 3% oleic acid, lipid body lysis and cell death were observed. Cell death and lipid body lysis may be partially explained by an imbalance in the expression of the genes involved in lipid storage, namely,
DGA1
,
DGA2
, and
LRO1
, as well as that of
TGL4
, which is involved in lipid remobilization.
TGL4
deletion and
DGA2
overexpression resulted in decreased oleic acid sensitivity and delayed cell death of Δ
Ylpex11
, which probably stemmed from the release of free fatty acids into the cytoplasm. All these results show that YlPex11p plays an important role in lipid homeostasis in
Y. lipolytica
.
In Vivo
Function of PTEX88 in Malaria Parasite Sequestration and Virulence
Authors: Matz Joachim M. , Ingmundson Alyssa , Costa Nunes Jean , Stenzel Werner , Matuschewski Kai , Kooij Taco W. A.
Published: March 2015

Malaria pathology is linked to remodeling of red blood cells by eukaryotic
Plasmodium
parasites. Central to host cell refurbishment is the trafficking of parasite-encoded virulence factors through the
Plasmodium
translocon of exported proteins (PTEX). Much of our understanding of its function is based on experimental work with cultured
Plasmodium falciparum
, yet direct consequences of PTEX impairment during an infection remain poorly defined. Using the murine malaria model parasite
Plasmodium berghei
, it is shown here that efficient sequestration to the pulmonary, adipose, and brain tissue vasculature is dependent on the PTEX components thioredoxin 2 (TRX2) and PTEX88. While
TRX2
-deficient parasites remain virulent,
PTEX88
-deficient parasites no longer sequester in the brain, correlating with abolishment of cerebral complications in infected mice. However, an apparent trade-off for virulence attenuation was spleen enlargement, which correlates with a strongly reduced schizont-to-ring-stage transition. Strikingly, general protein export is unaffected in
PTEX88
-deficient mutants that mature normally
in vitro
. Thus, PTEX88 is pivotal for tissue sequestration
in vivo
, parasite virulence, and preventing exacerbation of spleen pathology, but these functions do not correlate with general protein export to the host erythrocyte. The presented data suggest that the protein export machinery of
Plasmodium
parasites and their underlying mechanistic features are considerably more complex than previously anticipated and indicate challenges for targeted intervention strategies.
The SrkA Kinase Is Part of the SakA Mitogen-Activated Protein Kinase Interactome and Regulates Stress Responses and Development in Aspergillus nidulans
Authors: Jaimes-Arroyo Rafael , Lara-Rojas Fernando , Bayram Özgür , Valerius Oliver , Braus Gerhard H. , Aguirre Jesús
Published: March 2015

Fungi and many other eukaryotes use specialized mitogen-activated protein kinases (MAPK) of the Hog1/p38 family to transduce environmental stress signals. In
Aspergillus nidulans
, the MAPK SakA and the transcription factor AtfA are components of a central multiple stress-signaling pathway that also regulates development. Here we characterize SrkA, a putative MAPK-activated protein kinase, as a novel component of this pathway. Δ
srkA
and Δ
sakA
mutants share a derepressed sexual development phenotype. However, Δ
srkA
mutants are not sensitive to oxidative stress, and in fact,
srkA
inactivation partially suppresses the sensitivity of Δ
sakA
mutant conidia to H
2
O
2
, tert-butyl-hydroperoxide (
t
-BOOH), and menadione. In the absence of stress, SrkA shows physical interaction with nonphosphorylated SakA in the cytosol. We show that H
2
O
2
induces a drastic change in mitochondrial morphology consistent with a fission process and the relocalization of SrkA to nuclei and mitochondria, depending on the presence of SakA. SakA-SrkA nuclear interaction is also observed during normal asexual development in dormant spores. Using SakA and SrkA S-tag pulldown and purification studies coupled to mass spectrometry, we found that SakA interacts with SrkA, the stress MAPK MpkC, the PPT1-type phosphatase AN6892, and other proteins involved in cell cycle regulation, DNA damage response, mRNA stability and protein synthesis, mitochondrial function, and other stress-related responses. We propose that oxidative stress induces DNA damage and mitochondrial fission and that SakA and SrkA mediate cell cycle arrest and regulate mitochondrial function during stress. Our results provide new insights into the mechanisms by which SakA and SrkA regulate the remodelling of cell physiology during oxidative stress and development.
Fulminant necrotising fasciitis by community-acquired methicillin-resistantStaphylococcus aureus
Authors: Non Lemuel , Kosmin Aaron
Published: March 2015

Community-acquired methicillin-resistantStaphylococcus aureus(CA-MRSA) is a rare cause of necrotising fasciitis (NF), and is usually not fulminant as in group AStreptococcus(GAS), the archetypal aetiology. We report an unusually fulminant case of NF by CA-MRSA in an immunocompetent patient. A 52-year-old man presented to the emergency department with 1 week of progressive left thigh pain and swelling. The patient had ecchymoses, bullae and hypoesthesia of the involved skin, and CT scan revealed extensive fascial oedema. He was immediately started on broad spectrum antibiotics. Within 12 h of presentation, he underwent surgical debridement. Despite aggressive supportive care, the patient died less than 24 h after presentation. MRSA, with an antibiogram suggestive of a community-acquired strain, was recovered from intraoperative specimens and admission blood cultures. This case underscores that CA-MRSA, while rarely reported, can cause a fulminant presentation of NF similar to GAS in immunocompetent patients.
Towards Context-Based Concurrent Formal Theories
Authors: Schumann Andrew
Published: March 2015

We define a kind of simple actions of labelled transition systems. These actions cannot be atomic; consequently, their compositions cannot be inductive. Their informal meaning is that in one simple action we can suppose the maximum of its modifications. Such actions are called hybrid. Then we propose two formal theories on hybrid actions (the hybrid actions are defined there as non-well-founded terms and non-well-founded formulas): group theory and Boolean algebra. Both theories possess many unusual properties such as the following one: the same member of this group theory behaves as multiplicative zero in respect to one members and as multiplicative unit in respect to other members.
Assessing and Evolving a Domain Specific Language for Formalizing Software Engineering Experiments: An Empirical Study
Authors: Freire Marília , Kulesza Uirá , Aranha Eduardo , Nery Gustavo , Costa Daniel , Jedlitschka Andreas , Campos Edmilson , Acuña Silvia T. , Gómez Marta N.
Published: March 2015

The research about the formalization and conduction of controlled experiments in software engineering has reported important insights and guidelines for their organization. However, the computational support to formalize and execute controlled experiments still requires deeper investigation. In this context, this paper presents an empirical study that evaluates a domain-specific language (DSL) proposed to formalize controlled experiments in software engineering. The language is part of a model-driven approach that allows the generation of executable workflows for the experiment participants, according to the statistical design of the experiment. Our study involves the modeling of 16 software engineering experiments to analyze the completeness and expressiveness of the investigated DSL when specifying different controlled experiments. The results highlight several limitations of the DSL that affect the formalization and execution of experiments. These outcomes were used to extend and improve the evaluated DSL. Finally, the improved version of the language was used to model the same experiments in order to illustrate the benefits of the proposed improvements.
Systematic Knowledge Engineering: Building Bodies of Knowledge from Published Research
Authors: Biffl Stefan , Kalinowski Marcos , Rabiser Rick , Ekaputra Fajar , Winkler Dietmar
Published: March 2015

Context. Software engineering researchers conduct systematic literature reviews (SLRs) to build bodies of knowledge (BoKs). Unfortunately, relevant knowledge collected in the SLR process is not publicly available, which considerably slows down building BoKs incrementally.

Objective. We present and evaluate the Systematic Knowledge Engineering (SKE) process to support efficiently building BoKs from published research.

Method. SKE is based on the SLR process and on Knowledge Engineering practices to build a Knowledge Base (KB) by reusing intermediate data extraction results from SLRs. We evaluated the feasibility of applying SKE by building a Software Inspection BoK KB from published experiments and a Software Product Line BoK KB from published experience reports. We compared the effort, benefits, and risks of building BoK KBs regarding the SKE and the traditional SLR processes.

Results. The application of SKE for incrementally collecting and organizing knowledge in the context of a BoK was feasible for different domains and different types of evidence. While the efforts for conducting the SKE and traditional SLR processes are comparable, SKE provides significant benefits for building BoKs.

Conclusions. SKE enables researchers in a scientific community to reuse and incrementally build knowledge in a BoK. SKE is ready to be evaluated in other software engineering domains.
Microengineered cell and tissue systems for drug screening and toxicology applications: Evolution ofin-vitroliver technologies
Authors: Usta O. B. , McCarty W. J. , Bale S. , Hegde M. , Jindal R. , Bhushan A. , Golberg I. , Yarmush M. L.
Published: March 2015

The liver performs many key functions, the most prominent of which is serving as the metabolic hub of the body. For this reason, the liver is the focal point of many investigations aimed at understanding an organism's toxicological response to endogenous and exogenous challenges. Because so many drug failures have involved direct liver toxicity or other organ toxicity from liver generated metabolites, the pharmaceutical industry has constantly sought superior, predictive in-vitro models that can more quickly and efficiently identify problematic drug candidates before they incur major development costs, and certainly before they are released to the public. In this broad review, we present a survey and critical comparison of in-vitro liver technologies along a broad spectrum, but focus on the current renewed push to develop "organs-on-a-chip". One prominent set of conclusions from this review is that while a large body of recent work has steered the field towards an ever more comprehensive understanding of what is needed, the field remains in great need of several key advances, including establishment of standard characterization methods, enhanced technologies that mimic the in-vivo cellular environment, and better computational approaches to bridge the gap between the in-vitro and in-vivo results.
Exact and Asymptotic Solutions of the Call Auction Problem
Authors: Toke Ioane Muni
Published: March 2015

The call auction is a widely used trading mechanism, especially during the opening and closing periods of financial markets. In this paper, we study a standard call auction problem where orders are submitted according to Poisson processes, with random prices distributed according to a general distribution F, and may be cancelled at any time. We compute the analytical expressions of the distributions of the traded volume, of the lower and upper bounds of the clearing prices, and of the price range of these possible clearing prices of the call auction. Using results from the theory of order statistics and a theorem on the limit of sequences of random variables with independent random indices, we derive the weak limits of all these distributions. In this setting, traded volume and bounds of the clearing prices are found to be asymptotically normal, while the clearing price range is asymptotically exponential. All the parameters of these distributions are explicitly derived as functions of the parameters of the incoming orders' flows.
Exercise intensity and the protection from postprandial vascular dysfunction in adolescents
Authors: Bond B. , Gates P. E. , Jackman S. R. , Corless L. M. , Williams C. A. , Barker A. R.
Published: March 2015

Acute exercise transiently improves endothelial function and protects the vasculature from the deleterious effects of a high-fat meal (HFM). We sought to identify whether this response is dependent on exercise intensity in adolescents. Twenty adolescents (10 male, 14.3 ± 0.3 yr) completed three 1-day trials: 1) rest (CON); 2) 8 × 1 min cycling at 90% peak power with 75 s recovery [high-intensity interval exercise (HIIE)]; and 3) cycling at 90% of the gas exchange threshold [moderate-intensity exercise (MIE)] 1 h before consuming a HFM (1.50 g/kg fat). Macrovascular and microvascular endothelial function was assessed before and immediately after exercise and 3 h after the HFM by flow-mediated dilation (FMD) and laser Doppler imaging [peak reactive hyperemia (PRH)]. FMD and PRH increased 1 h after HIIE [ P < 0.001, effect size (ES) = 1.20 and P = 0.048, ES = 0.56] but were unchanged after MIE. FMD and PRH were attenuated 3 h after the HFM in CON ( P < 0.001, ES = 1.78 and P = 0.02, ES = 0.59). FMD remained greater 3 h after the HFM in HIIE compared with MIE ( P < 0.001, ES = 1.47) and CON ( P < 0.001, ES = 2.54), and in MIE compared with CON ( P < 0.001, ES = 1.40). Compared with CON, PRH was greater 3 h after the HFM in HIIE ( P = 0.02, ES = 0.71) and MIE ( P = 0.02, ES = 0.84), with no differences between HIIE and MIE ( P = 0.72, ES = 0.16). Plasma triacylglycerol concentration and total antioxidant status concentration were not different between trials. We conclude that exercise intensity plays an important role in protecting the vasculature from the deleterious effects of a HFM. Performing HIIE may provide superior vascular benefits than MIE in adolescent groups.
Acute inhibition of ATP-sensitive K+ channels impairs skeletal muscle vascular control in rats during treadmill exercise
Authors: Holdsworth Clark T. , Copp Steven W. , Ferguson Scott K. , Sims Gabrielle E. , Poole David C. , Musch Timothy I.
Published: March 2015

The ATP-sensitive K+ (KATP) channel is part of a class of inward rectifier K+ channels that can link local O2 availability to vasomotor tone across exercise-induced metabolic transients. The present investigation tested the hypothesis that if KATP channels are crucial to exercise hyperemia, then inhibition via glibenclamide (GLI) would lower hindlimb skeletal muscle blood flow (BF) and vascular conductance during treadmill exercise. In 27 adult male Sprague-Dawley rats, mean arterial pressure, blood lactate concentration, and hindlimb muscle BF (radiolabeled microspheres) were determined at rest ( n = 6) and during exercise ( n = 6–8, 20, 40, and 60 m/min, 5% incline, i.e., ∼60–100% maximal O2 uptake) under control and GLI conditions (5 mg/kg intra-arterial). At rest and during exercise, mean arterial pressure was higher (rest: 17 ± 3%, 20 m/min: 5 ± 1%, 40 m/min: 5 ± 2%, and 60 m/min: 5 ± 1%, P < 0.05) with GLI. Hindlimb muscle BF (20 m/min: 16 ± 7%, 40 m/min: 30 ± 9%, and 60 m/min: 20 ± 8%) and vascular conductance (20 m/min: 20 ± 7%, 40 m/min: 33 ± 8%, and 60 m/min: 24 ± 8%) were lower with GLI during exercise at 20, 40, and 60 m/min, respectively ( P < 0.05 for all) but not at rest. Within locomotory muscles, there was a greater fractional reduction present in muscles comprised predominantly of type I and type IIa fibers at all exercise speeds ( P < 0.05). Additionally, blood lactate concentration was 106 ± 29% and 44 ± 15% higher during exercise with GLI at 20 and 40 m/min, respectively ( P < 0.05). That KATP channel inhibition reduces hindlimb muscle BF during exercise in rats supports the obligatory contribution of KATP channels in large muscle mass exercise-induced hyperemia.
20-Hydroxyeicosatetraenoic acid involved in endothelial activation and thrombosis
Authors: Wang Jiaxing , Li Hua , He Jinlong , Li Bochuan , Bao Qiankun , Zhang Xu , Lv Zhizhen , Zhang Youyi , Han Jingyan , Ai Ding , Zhu Yi
Published: March 2015

Endothelial cells play an important role in the process of coagulation and the function of platelets. We have previously reported that 20-hydroxyeicosatetraenoic acid (20-HETE), a metabolite of arachidonic acid, increased platelet aggregation and induced hemostasis. The purpose of the present study is to investigate whether 20-HETE-mediated endothelial activation has effect on the coagulation and platelet aggregation. C57Bl/6 mice were treated with PBS or 20-HETE (20 μg/kg) for 2 h, and then we performed a carotid artery or femoral artery thrombosis model by FeCl3. Detection of blood flow indicated that 20-HETE pretreatment accelerated formation of thrombus in both common carotid artery and femoral artery. In vitro, the secretion and expression of von Willebrand factor (vWF) in cultured human umbilical vein endothelial cells (HUVECs) with 20-HETE stimulation were increased, subsequently. The protein level of vWF in HUVECs was decreased at 1 h but increased with prolonged treatment with 20-HETE (>4 h). In contrast, vWF in the culture medium was increased under administration of 20-HETE at 1 h. As a result, adhesion of platelets on HUVECs was significantly increased by 20-HETE. In HUVECs, the extracellular signal-regulated kinase (ERK) pathway was activated by 20-HETE in a dose-dependent manner, and the inhibitors of ERK and L-type Ca2+channel blocked the release of vWF mediated by 20-HETE. In conclusion, 20-HETE instigates endothelial activation and induces the expression and secretion of vWF via the activation of ERK and calcium channel and therefore triggers thrombosis.
Induction and functional significance of the heme oxygenase system in pathological shear stress in vivo
Authors: Kang Lu , Hillestad Matthew L. , Grande Joseph P. , Croatt Anthony J. , Barry Michael A. , Farrugia Gianrico , Katusic Zvonimir S. , Nath Karl A.
Published: March 2015

The present study examined the heme oxygenase (HO) system in an in vivo murine model of pathological shear stress induced by partial carotid artery ligation. In this model, along with upregulation of vasculopathic genes, HO-1 is induced in the endothelium and adventitia, whereas HO-2 is mainly upregulated in the endothelium. Within minutes of ligation, NF-κB, a transcription factor that upregulates vasculopathic genes and HO-1, is activated. Failure to express either HO-1 or HO-2 exaggerates the reduction in carotid blood flow and exacerbates vascular injury. After artery ligation, comparable induction of HO-2 occurred in HO-1+/+and HO-1−/−mice, whereas HO-1 induction was exaggerated in HO-2−/−mice compared with HO-2+/+mice. Upregulation of HO-1 by an adeno-associated viral vector increased vascular HO-1 expression and HO activity and augmented blood flow in both ligated and contralateral carotid arteries. Acute inhibition of HO activity decreased flow in the ligated carotid artery, whereas a product of HO, carbon monoxide (CO), delivered by CO-releasing molecule-3, increased carotid blood flow. In conclusion, in the partial carotid artery ligation model of pathological shear stress, this study provides the first demonstration of 1) upregulation and vasoprotective effects of HO-1 and HO-2 and the vasorelaxant effects of CO as well as 2) vascular upregulation of HO-1 in vivo by an adeno-associated viral vector that is attended by a salutary vascular response. Induction of HO-1 may reside in NF-κB activation, and, along with induced HO-2, such upregulation of HO-1 provides a countervailing vasoprotective response in pathological shear stress in vivo.
Suppression of endothelial CD39/ENTPD1 is associated with pulmonary vascular remodeling in pulmonary arterial hypertension
Authors: Helenius Mikko H. , Vattulainen Sanna , Orcholski Mark , Aho Joonas , Komulainen Anne , Taimen Pekka , Wang Lingli , de Jesus Perez Vinicio A. , Koskenvuo Juha W. , Alastalo Tero-Pekka
Published: March 2015

Endothelial cell (EC) dysfunction plays a role in the pathobiology of occlusive vasculopathy in pulmonary arterial hypertension (PAH). Purinergic signaling pathways, which consist of extracellular nucleotide and nucleoside-mediated cell signaling through specific receptors, are known to be important regulators of vascular tone and remodeling. Therefore, we hypothesized that abnormalities in the vascular purinergic microenvironment are associated with PAH. Enzymatic clearance is crucial to terminate unnecessary cell activation; one of the most abundantly expressed enzymes on the EC surface is E-NTPDase1/CD39, which hydrolyzes ATP and ADP to AMP. we used histological samples from patients and healthy donors, radioisotope-labeled substrates to measure ectoenzyme activity, and a variety of in vitro approaches to study the role of CD39 in PAH. Immunohistochemistry on human idiopathic PAH (IPAH) patients' lungs demonstrated that CD39 was significantly downregulated in the endothelium of diseased small arteries. Similarly, CD39 expression and activity were decreased in cultured pulmonary ECs from IPAH patients. Suppression of CD39 in vitro resulted in EC phenotypic switch that gave rise to apoptosis-resistant pulmonary arterial endothelial cells and promoted a microenvironment that induced vascular smooth muscle cell migration. we also identified that the ATP receptor P2Y11 is essential for ATP-mediated EC survival. Furthermore, we report that apelin, a known regulator of pulmonary vascular homeostasis, can potentiate the activity of CD39 both in vitro and in vivo. we conclude that sustained attenuation of CD39 activity through ATP accumulation is tightly linked to vascular dysfunction and remodeling in PAH and could represent a novel target for therapy.
Evaluation of cigarette smoke-induced emphysema in mice using quantitative micro-computed tomography
Authors: Sasaki Mamoru , Chubachi Shotaro , Kameyama Naofumi , Sato Minako , Haraguchi Mizuha , Miyazaki Masaki , Takahashi Saeko , Betsuyaku Tomoko
Published: March 2015

Chronic cigarette smoke (CS) exposure provokes variable changes in the lungs, and emphysema is an important feature of chronic obstructive pulmonary disease. The usefulness of micro-computed tomography (CT) to assess emphysema in different mouse models has been investigated, but few studies evaluated the dynamic structural changes in a CS-induced emphysema mouse model. A novel micro-CT technique with respiratory and cardiac gating has resulted in high-quality images that enable processing for further quantitative and qualitative analyses. Adult female C57BL/6J mice were repeatedly exposed to mainstream CS, and micro-CT scans were performed at 0, 4, 12, and 20 wk. Emphysema was also histologically quantified at each time point. Air-exposed mice and mice treated with intratracheal elastase served as controls and comparisons, respectively. End-expiratory lung volume, corresponding to functional residual volume, was defined as the calculated volume at the phase of end-expiration, and it evaluated air trapping. The end-expiratory lung volumes of CS-exposed mice were significantly larger than those of air controls at 12 and 20 wk, which was in line with alveolar enlargement and destruction by histological quantification. However, CS exposure neither increased low attenuation volume nor decreased the average lung CT value at any time point, unlike the elastase-instilled emphysema model. CS-exposed mice had rather higher average lung CT values at 4 and 12 wk. This is the first study characterizing a CS-induced emphysema model on micro-CT over time in mice. Moreover, these findings extend our understanding of the distinct pathophysiology of CS-induced emphysema in mice.
Keratin 19, a Cancer Stem Cell Marker in Human Hepatocellular Carcinoma
Authors: Kawai Takayuki , Yasuchika Kentaro , Ishii Takamichi , Katayama Hokahiro , Yoshitoshi Elena Yukie , Ogiso Satoshi , Kita Sadahiko , Yasuda Katsutaro , Fukumitsu Ken , Mizumoto Masaki , Hatano Etsuro , Uemoto Shinji
Published: March 2015

Purpose: Keratin 19 (K19) is a known marker of poor prognosis and invasion in human hepatocellular carcinoma (HCC). However, the relationship between K19 and cancer stem cells (CSCs) is unclear. Here, we determined whether K19 can be used as a new CSC marker and therapeutic target in HCC.

Experimental Design: HCC cell lines were transfected with a K19 promoter–driven enhanced green fluorescence protein gene. CSC characteristics, epithelial–mesenchymal transition (EMT), and TGFb/Smad signaling were examined in FACS-isolated K19+/K19− cells. K19 and TGFb receptor 1 (TGFbR1) expression in 166 consecutive human HCC surgical specimens was examined immunohistochemically.

Results: FACS-isolated single K19+ cells showed self-renewal and differentiation into K19− cells, whereas single K19− cells did not produce K19+ cells. K19+ cells displayed high proliferation capacity and 5-fluorouracil resistance in vitro. Xenotransplantation into immunodeficient mice revealed that K19+ cells reproduced, differentiated into K19− cells, and generated large tumors at a high frequency in vivo. K19+ cells were found to be involved in EMT and the activation of TGFb/Smad signaling, and these properties were suppressed by K19 knockdown or treatment with a TGFbR1 inhibitor. The TGFbR1 inhibitor also showed high therapeutic effect against K19+ tumor in the mouse xenograft model. Immunohistochemistry of HCC specimens showed that compared with K19− patients, K19+ patients had significantly poorer recurrence-free survival and higher tumor TGFbR1 expression.

Conclusions: K19 is a new CSC marker associated with EMT and TGFb/Smad signaling, and it would thus be a good therapeutic target for TGFbR1 inhibition. Clin Cancer Res; 21(13); 3081–91. ©2015 AACR.
Do bacharelismo liberal à criminologia no Brasil
Authors: Alvarez Marcos César
Published: March 2015

O artigo discute as ideias desenvolvidas no livro de Sérgio Adorno, Os Aprendizes do Poder, originalmente apresentado como tese de doutoramento defendida no ano de 1984 na Universidade de São Paulo, e sua influência posterior no trabalho Bacharéis, Criminologistas e Juristas: Saber Jurídico e Nova Escola Penal no Brasil, também defendido como tese de doutoramento em 1996 na mesma instituição. Busco, desse modo, estabelecer as conexões intelectuais existentes entre minha trajetória de formação e as questões que Adorno desenvolvia como professor e pesquisador na USP, principalmente acerca das relações entre a sociedade e o direito no Brasil.
Gestão do poder judiciário: justiça, eficiência e inovação
Authors: Oliveira Regis Fernandes de
Published: March 2015

O presente ensaio se destina a lançar luzes sobre como surgiu, como deveria ser, o que é, como atua e como poderia ser o Judiciário brasileiro. As discussões passam pela necessidade do aprimoramento da gestão, da eficiência e da democratização do Judiciário. Por fim, lançamos algumas propostas que se destinam a repensar as estruturas e os objetivos do Judiciário.
Alternativas de resolução de conflitos e justiça restaurativa no Brasil
Authors: Azevedo Rodrigo Ghiringhelli de , Pallamolla Raffaella da Porciuncula
Published: March 2015

O presente artigo discute o desenvolvimento de formas alternativas de administração de conflitos no Brasil, tendo em vista o contexto mais amplo de crise da administração da justiça e o surgimento, não apenas no contexto brasileiro, de um conjunto de mecanismos judiciais ou extrajudiciais que se utiliza de negociação, conciliação, mediação e arbitragem. Centrando a análise na chamada justiça restaurativa, cuja expansão em diversos países se deve a uma série de motivos comuns, como a crise de legitimidade do sistema penal, a busca de abordagens alternativas ao delito (ou conflito), as reivindicações das vítimas, buscou-se identificar os argumentos favoráveis e contrários a esse modelo do ponto de vista da extensão da rede de controle penal e da ampliação do acesso à justiça, bem como analisar as peculiaridades para a sua implantação no Brasil, tendo em vista as características da cultura jurídica brasileira.
Como recrutar magistrados?
Authors: Nalini José Renato
Published: March 2015

O recrutamento de magistrados é um dos principais desafios que deve enfrentar a justiça do século XXI. O tema é sensível. Envolve a discussão dos limites do modelo tradicional de seleção de novos quadros, baseados na aferição da capacidade de memorização dos candidatos e em metodologias de avaliação que, embora tenham incorporado temáticas de caráter interdisciplinar, são rapidamente colonizadas pela lógica dos cursos preparatórios e pela compulsão de discutir minúcias. Como superar esse gargalo estrutural? Como identificar os caracteres vocacionais? Espera-se como resultado apresentar um panorama contemporaneamente situado acerca dessa discussão.
Continuing the Dialogue on Interpretation of Revelation: Responses and Reflections
Authors: Koester Craig R.
Published: March 2015

Four aspects of the interpretation of Revelation are considered. First, the main structure of Revelation includes worship scenes at transition points between major vision cycles. The expression ‘in the Spirit’ plays an important supporting role by linking the initial visions of the churches on earth and God in heaven, and later contrasting Babylon with New Jerusalem. Second, discerning the work of the Spirit was a challenge for Revelation’s early readers. Criteria include witness to Jesus and fostering worship of God. Third, Revelation has a dynamic approach to salvation, which involves both warnings of judgment and promises that give hope. Fourth, Revelation focuses on the situation of the early readers, who lived under the Roman Empire, but its imagery includes prophetic critiques from other periods, helping the imagery to engage readers beyond that original context.
Redescription of the females of Hystrignathus rigidus Leidy, 1850 (Nematoda: Hystrignathidae), parasites of Odontotaenius disjunctus (Coleoptera: Passalidae) from eastern USA
Authors: MORFFE JANS , GARCÍA NAYLA , DAVIS ANDREW K.
Published: March 2015

The female of Hystrignathus rigidus Leidy, 1850 (Nematoda: Hystrignathidae) is redescribed on the basis of new material from Odontotaenius disjunctus (Coleoptera: Passalidae) from Athens, Georgia, USA; which also constitutes a new locality record. SEM images are provided for the first time for the species. It is also first shown that H. rigidus presents ridged-shelled eggs. A differential diagnosis is provided. H. rigidus can be differentiated from the rest of the species of this genus by having a short, non inflated first cephalic annule; spines that surpass the level of the oesophagus, an absence of lateral alae, ridged-shelled eggs and its length of the body and tail. The material from the present study differs from a previous redescription by Christie (1934) by its shorter body (2.125–2.950 vs. 2.130–4.200), first cephalic annule (0.003–0.005 vs. 0.012) and oesophagus (0.350–0.430 vs. 0.650–0.670).
Preconditioning With Tauroursodeoxycholic Acid Protects Against Contrast-Induced HK-2 Cell Apoptosis by Inhibiting Endoplasmic Reticulum Stress
Authors: Peng Pingan , Ma Qian , Wang Le , Zhang Ou , Han Hongya , Liu Xiaoli , Zhou Yujie , Zhao Yingxin
Published: March 2015

To investigate whether tauroursodeoxycholic acid (TUDCA) could attenuate contrast media (CM)-induced renal tubular cell apoptosis by inhibiting endoplasmic reticulum stress (ERS), we exposed HK-2 cells to increasing doses of meglumine diatrizoate (20, 40, and 80 mg I/mL) for 2 to 16 hours, with/without TUDCA preconditioning for 24 hours. Cell viability test, Hoechst 33258 staining, and flow cytometry were used to detect meglumine diatrizoate-induced cell apoptosis, while real-time polymerase chain reaction and Western blot analysis were used to measure the expressions of ERS markers of glucose-regulated protein 78 (GRP78), activating transcription factor 4 (ATF4), and the apoptosis-related marker of caspase 12. Cell apoptosis and messenger RNA (mRNA) expression of GRP78 ( P = .005), ATF4 ( P = .01), and caspase 12 ( P = .001) were significantly higher in the CM 4 hours group than the control as well as the protein expressions. The TUDCA preconditioning reduced the mRNA expression of GRP78, ATF4, and caspase 12 in the CM 4 hours groups ( P = .009, .019, and .003, respectively) as well as the protein expression. In conclusion, TUDCA could protect renal tubular cells from meglumine diatrizoate-induced apoptosis by inhibiting ERS.
All-Arthroscopic Suprapectoral Versus Open Subpectoral Tenodesis of the Long Head of the Biceps Brachii
Authors: Gombera Mufaddal Mustafa , Kahlenberg Cynthia A. , Nair Rueben , Saltzman Matthew D. , Terry Michael A.
Published: March 2015

Background:

Pathologic changes of the long head of the biceps tendon are a recognized source of shoulder pain in adults that can be treated with tenotomy or tenodesis when nonoperative measures are not effective. It is not clear whether arthroscopic or open biceps tenodesis has a clinical advantage.

Hypothesis:

Pain relief and shoulder function after all-arthroscopic suprapectoral biceps tenodesis are similar to outcomes after an open subpectoral tenodesis.

Study Design:

Cohort study; Level of evidence, 3.

Methods:

A prospective database was reviewed for patients undergoing an all-arthroscopic suprapectoral or open subpectoral biceps tenodesis. Adult patients with a minimum 18-month follow-up were included. Patients undergoing a concomitant rotator cuff or labral repair were excluded. The groups were matched to age within 3 years, sex, and time to follow-up within 3 months. Pain improvement, development of a “Popeye” deformity, muscle cramping, postoperative American Shoulder and Elbow Surgeons scores, satisfaction scores, and complications were evaluated.

Results:

Forty-six patients (23 all-arthroscopic, 23 open) with an average age of 57.2 years (range, 45-70 years) were evaluated at a mean follow-up of 30.1 months (range, 21.1-44.9 months). No patients in either group developed a Popeye deformity or complained of arm cramping. There was no significant difference in mean American Shoulder and Elbow Surgeons scores between the open and all-arthroscopic groups (92.3 vs 88.9; P = .42); similarly, there was no significant difference in patient satisfaction scores between the groups (8.9 vs 9.1; P = .73). Eighteen patients (78.3%) in the arthroscopic cohort and 16 (69.6%) in the open cohort fully returned to athletic activity ( P = .50). Eight patients (34.8%) in the arthroscopic group and 10 (39.1%) in the open group reported pain at night or with heavy activities. There were no complications in the all-arthroscopic group. There were 2 complications in the open group that resolved by final follow-up.

Conclusion:

Biceps tenodesis remains a reliable treatment for pathologic abnormality of the long head of the biceps. Patients undergoing an all-arthroscopic suprapectoral tenodesis in the distal aspect or distal to the bicipital groove showed similar pain relief and clinical outcomes as compared with patients undergoing open subpectoral tenodesis. Open subpectoral biceps tenodesis may carry a higher complication risk secondary to a more invasive technique.