bluuebunny/crossref_metadata_2025_split huggingface dataset:
ERK and p38MAPK pathways regulate myosin light chain phosphatase and contribute to Ca2+ sensitization of intestinal smooth muscle contraction
Authors: Ihara E. , Yu Q. , Chappellaz M. , MacDonald J. A. 
Published: December 2014

AbstractBackgroundMitogen‐activated protein kinases (MAPKs), including extracellular signal‐regulated protein kinase (ERK) and p38MAPK, are known regulators of smooth muscle contractility. The contraction of smooth muscle is mainly regulated by the phosphorylation of regulatory light chains of myosin II (LC20), which is driven by the balance between myosin light chain kinase (MLCK) and myosin light chain phosphatase (MLCP). We hypothesized that one possible mechanism for MAPK‐dependent modulation of intestinal smooth muscle contractility is via the regulation of MLCP activity.MethodsContractile responses to carbachol (CCh) and effects of MAPK inhibitors on CCh‐induced contractions were assessed with isolated rat ileal longitudinal smooth muscle strips. Biochemical assessments of MLCP activity and myosin phosphatse targeting subunit (MYPT1) and CPI‐17 phosphorylations were completed.Key ResultsTreatment of ileal smooth muscle with PD98059 (10 μM; MEK inhibitor) or SB203580 (10 μM; p38MAPK inhibitor) significantly inhibited CCh‐induced contractile force. Decreased MLCP activity was observed during sustained contractions induced by CCh; the MLCP activity was recovered by treatment with PD98059 and SB203580. However, MYPT1 (Thr697 and Thr855) and CPI‐17 (Thr38) phosphorylations were not affected. Application of ML‐7 (MLCK inhibitor) during CCh‐induced sustained contraction elicited an MLCP‐dependent relaxation, the rate of which was accelerated by application of PD98059 and SB203580 with proportional changes in LC20 phosphorylation levels but not MYPT1 phosphorylation (Thr697 or Thr855).Conclusions & InferencesERK and p38MAPK contribute to CCh‐induced sustained contraction in a LC20 phosphorylation dependent manner. Moreover, both kinases inhibit MLCP activity possibly by a novel mechanism.
Characterization of ghrelin‐sensitive neurons in the lumbosacral defecation center in rats
Authors: Naitou K. , Shiina T. , Sugita R. , Nakamori H. , Shimizu Y. 
Published: December 2014

AbstractBackgroundGhrelin is involved in the regulation of somatic growth, feeding behavior and energy homeostasis. Ghrelin stimulates neuropeptide Y (NPY) neurons and activates intracellular AMP‐activated protein kinase (AMPK) in the hypothalamus. These NPY neurons also express the leptin receptor and leptin inhibits ghrelin‐induced activation of NPY neurons. In the spinal cord, we have demonstrated colokinetic action of ghrelin. However, the precise characteristics of the ghrelin‐sensitive neurons remain to be clarified. The aim of this study was firstly to confirm that the action of ghrelin is mediated via a neurogenic pathway in the spinal cord, and secondly to characterize the ghrelin‐sensitive neurons by comparing with hypothalamic ghrelin‐sensitive neurons.MethodsRats were anesthetised with alpha‐chloralose and ketamine, and colorectal intraluminal puressure and expelled volume were recorded in vivo. Drugs were applied intrathecally.Key ResultsGhrelin caused enhancement of propulsive contractions. Tetrodotoxin completely blocked the colokinetic effect of ghrelin. An AMPK activator, aminoimidazole carboxamide ribonucleotide, failed to mimic the ghrelin effect. Leptin had no effect on the spontanious contractions and did not exert a suppressive effect on the ghrelin‐enhanced colorectal motility. An NPY Y1 receptor antagonist did not affect the action of ghrelin. NPY had no effect on the colorectal motility.Conclusions & InferencesThis study showed that intrathecal injection of ghrelin stimulates colorectal motility by acting on ghrelin‐sensitive neurons in the lumbosacral defecation center. The characteristics of ghrelin‐sensitive neurons in the spinal cord are quite different from those of ghrelin‐sensitive neurons in the hypothalamus.
Corticotrophin‐releasing factor 1 activation in the central amygdale and visceral hyperalgesia
Authors: Taché Y. 
Published: December 2014

AbstractCorticotropin‐releasing factor (CRF)‐CRF1 receptor in the brain plays a key role in stress‐related alterations of behavior including anxiety/depression, and autonomic and visceral functions. In particular, CRF1 signaling mediates hypersensitivity to colorectal distension (CRD) in various models (early life adverse events, repeated psychological stress, chronic high anxiety, postcolonic inflammation, or repeated nociceptive CRD). So far, knowledge of brain sites involved is limited. A recent article demonstrates in rats that CRF microinjected into the central amygdala (CeA) induces a hyperalgesic response to CRD and enhances the noradrenaline and dopamine levels at this site. The visceral and noradrenaline, unlike dopamine, responses were blocked by a CRF1 antagonist injected into the CeA. Here, we review the emerging role that CRF‐CRF1 signaling plays in the CeA to induce visceral hypersensitivity. In the somatic pain field, CRF in the CeA was shown to induce pain sensitization. This is mediated by the activation of postsynaptic CRF1 receptors and protein kinase A signaling that increases N‐methyl‐d‐aspartate receptor neurotransmission. In addition, the activation of tetraethylamonium‐sensitive ion channels such as Kv3 accelerates repolarization and firing rate. Whether facilitation of pain transmission underlies CRF action in the CeA‐induced visceral hypersensitivity will need to be delineated. CRF1 signaling in the CeA is also an important component of the neuronal circuitry inducing anxiety‐like behavior and positioned at the interphase of the reciprocal relationship between pain and affective state. The hyperactivity of this system may represent the neuroanatomical and biochemical substrate contributing to the coexpression of hypersensitivity to CRD and mood disorders in subsets of irritable bowel syndrome patients.
Characterization of two CENH3 genes and their roles in wheat evolution
Authors: Yuan Jing , Guo Xiang , Hu Jing , Lv Zhenling , Han Fangpu 
Published: December 2014

Summary

Wheat evolution is complex as a result of successive rounds of allopolyploidization and continuous selection during domestication.

Diploid and tetraploid wheat species (Triticum spp.) were used as model systems in which to study the role of centromere‐specific histone H3 variant (CENH3) in wheat evolution.

We characterized two types of CENH3 genes, named αCENH3 and βCENH3, each of which has three slightly different copies derived from the AA, BB and DD genomes. Specific antibodies were raised against the two CENH3 proteins and were co‐localized to centromeres with subtle differences. In most tetraploid wheat species, CENH3 genes are more highly expressed from the AA genome. In wild tetraploids, βCENH3 has a much lower expression level than αCENH3, while in cultivated tetraploids βCENH3 transcripts are enhanced to near αCENH3 levels. Comparison of the CENH3 proteins in wild and cultivated tetraploids revealed that the histone folding domain (HFD) of only βCENH3 is under positive selection, especially in the region responsible for targeting of CENH3 to the centromere.

Taken together, positive selection of βCENH3 and its increased expression in tetraploid cultivars are indicative of adaptive evolution. Furthermore, the differences in localization between αCENH3 and βCENH3 observed using fiber fluorescence in situ hybridization (FISH) and immunodetection and in developmental phenotypes resulting from virus‐reduced gene silencing imply their functional diversification during wheat evolution.
Relatedness is a poor predictor of negative plant–soil feedbacks
Authors: Mehrabi Zia , Tuck Sean L. 
Published: December 2014

Summary

Understanding the mechanisms underlying negative plant–soil feedbacks remains a critical challenge in plant ecology. If closely related species are more similar, then phylogeny could be used as a predictor for plant species interactions, simplifying our understanding of how plant–soil feedbacks structure plant communities, underlie invasive species dynamics, or reduce agricultural productivity.

Here, we test the utility of phylogeny for predicting plant–soil feedbacks by undertaking a hierarchical Bayesian meta‐analysis on all available pairwise plant–soil feedback experiments conducted over the last two decades, including 133 plant species in 329 pairwise interactions.

We found that the sign and magnitude of plant–soil feedback effects were not explained by the phylogenetic distance separating interacting species. This result was consistent across different life forms, life cycles, provenances, and phylogenetic scales.

Our analysis shows that, contrary to widespread assumption, relatedness is a poor predictor of plant–soil feedback effects.
Exposure of barley plants to low Pi leads to rapid changes in root respiration that correlate with specific alterations in amino acid substrates
Authors: Alexova Ralitza , Nelson Clark J. , Jacoby Richard P. , Millar A. Harvey 
Published: December 2014

Summary

The majority of inorganic phosphate (Pi) stress studies in plants have focused on the response after growth has been retarded. Evidence from transcript analysis, however, shows that a Pi‐stress specific response is initiated within minutes of transfer to low Pi and in crop plants precedes the expression of Pi transporters and depletion of vacuolar Pi reserves by days.

In order to investigate the physiological and metabolic events during early exposure to low Pi in grain crops, we monitored the response of whole barley plants during the first hours following Pi withdrawal.

Lowering the concentration of Pi led to rapid changes in root respiration and leaf gas exchange throughout the early phase of the light course. Combining amino and organic acid analysis with 15N labelling we show a root‐specific effect on nitrogen metabolism linked to specific substrates of respiration as soon as 1 h following Pi withdrawal; this explains the respiratory responses observed and was confirmed by stimulation of respiration by exogenous addition of these respiratory substrates to roots.

The rapid adjustment of substrates for respiration in roots during short‐term Pi‐stress is highlighted and this could help guide roots towards Pi‐rich soil patches without compromising biomass accumulation of the plant.
Modelling demand for liquefied petroleum gas (LPG) in Ghana: current dynamics and forecast
Authors: Mensah Justice Tei 
Published: December 2014

AbstractGas is fast becoming an integral component of the energy mix in Ghana and holds huge prospects for the future. However, there is still great uncertainty surrounding the size of this potential market and often results in supply shortfalls. The recurrent shortages in the supply of liquefied petroleum gas (LPG) for domestic and industrial consumption pose a great challenge to the goal of promoting access and utilisation of modern and efficient energy to engender sustainable development in Ghana. As a result, this paper investigates the long‐ and short‐run demand drivers of LPG in Ghana and presents a 10‐year forecast of future trends in the demand using the autoregressive distributed lag and partial adjustment model techniques. Results identify income, price and urbanisation as the main drivers of demand. Projections from all three scenarios reveal that demand for LPG will reach a minimum of 5.9 million metric tons by the year 2022. This result has serious implications on both demand and supply side management, and thus calls for stringent efforts to attract the requisite infrastructure to ensure stable and reliable supply of LPG to meet domestic and industrial demands.
Impact of economic and non‐economic factors on gasoline demand: a varying parameter model for Sweden and the UK
Authors: Karimu Amin 
Published: December 2014

AbstractThis paper investigated the impact of price, income and non‐economic factors on gasoline demand using a structural time series model. The results indicated that non‐economic factors did have an impact on gasoline demand and also one of the largest contributors to changes in gasoline demand in both countries, especially after the 1990s. The results from the time‐varying parameter model indicated that both price and income elasticities were varying over time, but the variations were insignificant for both Sweden and the UK. The estimated gasoline trend also showed a similar pattern for the two countries, increasing continuously up to 1990 and taking a downturn thereafter.
Modelling oil price volatility before, during and after the global financial crisis
Authors: Salisu Afees A. 
Published: December 2014

AbstractIn this paper, we evaluate the comparative performance of volatility models for oil price using daily returns of crude oil price. The innovations of this paper are in three folds: (i) we consider two prominent oil prices namely Brent and West Texas Intermediate (WTI); (ii) we analyse these prices across three subsamples namely periods before, during and after the global financial crisis; and (iii) we also analyse the comparative performance of both symmetric and asymmetric volatility models for these oil prices. We find inconsistent patterns in the performance of the volatility models over the subsamples. On the average, however, we find evidence of leverage effects in both oil prices and therefore, investors in the oil market react to news. Specifically, we find that bad news in the oil market increased volatility in crude oil price than good news. We also find high level of persistence in the volatility of WTI and Brent although the latter appears more persistent than the former while the period of global financial crisis recorded the highest level of persistence in both prices. Also, we find that during the global financial crisis, risk averse investors shifted assets from the oil market to other less risky assets.
Propofol–ketamine or propofol–remifentanil for deep sedation and analgesia in pediatric patients undergoing burn dressing changes: a randomized clinical trial
Authors: Seol Tai‐Kyung , Lim Jin‐Kyu , Yoo Eun‐Kyung , Min Seong‐Won , Kim Chong‐Soo , Hwang Jin‐Young 
Published: December 2014

SummaryObjectiveIn this study, we compared the propofol–ketamine and propofol–remifentanil combinations for deep sedation and analgesia during pediatric burn wound dressing changes.MethodsFifty pediatric patients aged 12–36 months, undergoing burn wound dressing changes, were randomly assigned to receive propofol–remifentanil (group PR) or propofol–ketamine (group PK) for deep sedation and analgesia. Patients in the group PR received 2 mg·kg−1 propofol and 0.1 μg·kg−1 remifentanil, and 0.05 μg·kg−1·min−1 remifentanil was infused continuously until the end of the procedure. Patients in the group PK received 2 mg·kg−1 propofol and 1 mg·kg−1 ketamine, and the same volume of isotonic saline was infused continuously until the end of the procedure. Additional propofol with remifentanil or ketamine was administered when required. Hemodynamic variables, drug requirements, occurrence of patient movement, surgeon's satisfaction score, recovery time, and the incidence of adverse events were recorded throughout the procedure and recovery.ResultsRecovery time was significantly shorter in the group PR compared to that in the group PK (10.3 [9.1–11.5] min vs 22.5 [20.3–25.6] min, median [interquartile range], respectively; P < 0.001). No significant hypotension or bradycardia occurred throughout the procedure. No significant differences were observed in terms of drug requirements, occurrence of patient movement, surgeon's satisfaction, incidence of respiratory depression, hypoxia, or nausea and vomitingConclusionsThe combinations of propofol–ketamine and propofol–remifentanil were effective for sedation and analgesia in pediatric patients undergoing burn dressing changes, but the propofol–remifentanil combination provided faster recovery compared to the propofol–ketamine combination.
Effects of organic matter addition on phosphorus availability to flooded and nonflooded rice in a P‐deficient tropical soil: a greenhouse study
Authors: Rakotoson T. , Six L. , Razafimanantsoa M. P. , Rabeharisoa L. , Smolders E. 
Published: December 2014

AbstractAddition of organic matter (OM) to flooded soils stimulates reductive dissolution of Fe(III) minerals, thereby mobilizing associated phosphate (P). Hence, OM management has the potential to overcome P deficiency. This study assessed if OM applications increases soil or mineral fertilizer P availability to rice under anaerobic (flooded) condition and if that effect is different relative to that in aerobic (nonflooded) soils. Rice was grown in P‐deficient soil treated with combinations of addition of mineral P (0, 26 mg P/kg), OM (0, ~9 g OM/kg as rice straw + cattle manure) and water treatments (flooded vs nonflooded) in a factorial pot experiment. The OM was either freshly added just before flooding or incubated moist in soil for 6 months prior to flooding; blanket N and K was added in all treatments. Fresh addition of OM promoted reductive dissolution of Fe(III) minerals in flooded soils, whereas no such effect was found when OM had been incubated for 6 months before flooding. Yield and shoot P uptake largely increased with mineral P addition in all soils, whereas OM addition increased yield and P uptake only in flooded soils following fresh OM addition. The combination of mineral P and OM gave the largest yield and P uptake. Addition of OM just prior to soil flooding increased P uptake but was insufficient to overcome P deficiency in the absence of mineral P. Larger applications of OM are unlikely to be more successful in flooded soils due to side effects, such as Fe toxicity.
Climate Variability and the Occurrence of Human Puumala Hantavirus Infections in Europe: A Systematic Review
Authors: Roda Gracia J. , Schumann B. , Seidler A. 
Published: December 2014

SummaryHantaviruses are distributed worldwide and are transmitted by rodents. In Europe, the infection usually manifests as a mild form of haemorrhagic fever with renal syndrome (HFRS) known as nephropathia epidemica (NE), which is triggered by the virus species Puumala. Its host is the bank vole (Myodes glareolus). In the context of climate change, interest in the role of climatic factors for the disease has increased. A systematic review was conducted to investigate the association between climate variability and the occurrence of human Puumala hantavirus infections in Europe. We performed a literature search in the databases MEDLINE, EMBASE and Web of Science. Studies that investigated Puumala virus infection and climatic factors in any European country with a minimum collection period of 2 years were included. The selection of abstracts and the evaluation of included studies were performed by two independent reviewers. A total of 434 titles were identified in the databases, of which nine studies fulfilled the inclusion criteria. The majority of studies were conducted in central Europe (Belgium, France and Germany), while only two came from the north (Sweden) and one from the south (Bosnia). Strong evidence was found for a positive association between temperature and NE incidence in central Europe, while the evidence for northern Europe so far appears insufficient. Results regarding precipitation were contradictory. Overall, the complex relationships between climate and hantavirus infections need further exploration to identify specific health risks and initiate appropriate intervention measures in the context of climate change.
LocZ Is a New Cell Division Protein Involved in Proper Septum Placement in Streptococcus pneumoniae
Authors: Holečková Nela , Doubravová Linda , Massidda Orietta , Molle Virginie , Buriánková Karolína , Benada Oldřich , Kofroňová Olga , Ulrych Aleš , Branny Pavel 
Published: December 2014

ABSTRACT

How bacteria control proper septum placement at midcell, to guarantee the generation of identical daughter cells, is still largely unknown. Although different systems involved in the selection of the division site have been described in selected species, these do not appear to be widely conserved. Here, we report that LocZ (Spr0334), a newly identified cell division protein, is involved in proper septum placement in
Streptococcus pneumoniae
. We show that
locZ
is not essential but that its deletion results in cell division defects and shape deformation, causing cells to divide asymmetrically and generate unequally sized, occasionally anucleated, daughter cells. LocZ has a unique localization profile. It arrives early at midcell, before FtsZ and FtsA, and leaves the septum early, apparently moving along with the equatorial rings that mark the future division sites. Consistently, cells lacking LocZ also show misplacement of the Z-ring, suggesting that it could act as a positive regulator to determine septum placement. LocZ was identified as a substrate of the Ser/Thr protein kinase StkP, which regulates cell division in S. pneumoniae. Interestingly, homologues of LocZ are found only in streptococci, lactococci, and enterococci, indicating that this close phylogenetically related group of bacteria evolved a specific solution to spatially regulate cell division.

IMPORTANCE
Bacterial cell division is a highly ordered process regulated in time and space. Recently, we reported that the Ser/Thr protein kinase StkP regulates cell division in Streptococcus pneumoniae, through phosphorylation of several key proteins. Here, we characterized one of the StkP substrates, Spr0334, which we named LocZ. We show that LocZ is a new cell division protein important for proper septum placement and likely functions as a marker of the cell division site. Consistently, LocZ supports proper Z-ring positioning at midcell. LocZ is conserved only among streptococci, lactococci, and enterococci, which lack homologues of the Min and nucleoid occlusion effectors, indicating that these bacteria adapted a unique mechanism to find their middle, reflecting their specific shape and symmetry.
A 2-Pyridone-Amide Inhibitor Targets the Glucose Metabolism Pathway of Chlamydia trachomatis
Authors: Engström Patrik , Krishnan K. Syam , Ngyuen Bidong D. , Chorell Erik , Normark Johan , Silver Jim , Bastidas Robert J. , Welch Matthew D. , Hultgren Scott J. , Wolf-Watz Hans , Valdivia Raphael H. , Almqvist Fredrik , Bergström Sven 
Published: December 2014

ABSTRACT

In a screen for compounds that inhibit infectivity of the obligate intracellular pathogen
Chlamydia trachomatis
, we identified the 2-pyridone amide KSK120. A fluorescent KSK120 analogue was synthesized and observed to be associated with the C. trachomatis surface, suggesting that its target is bacterial. We isolated KSK120-resistant strains and determined that several resistance mutations are in genes that affect the uptake and use of glucose-6-phosphate (G-6P). Consistent with an effect on G-6P metabolism, treatment with KSK120 blocked glycogen accumulation. Interestingly, KSK120 did not affect
Escherichia coli
or the host cell. Thus, 2-pyridone amides may represent a class of drugs that can specifically inhibit C. trachomatis infection.

IMPORTANCE
Chlamydia trachomatis
is a bacterial pathogen of humans that causes a common sexually transmitted disease as well as eye infections. It grows only inside cells of its host organism, within a parasitophorous vacuole termed the inclusion. Little is known, however, about what bacterial components and processes are important for C. trachomatis cellular infectivity. Here, by using a visual screen for compounds that affect bacterial distribution within the chlamydial inclusion, we identified the inhibitor KSK120. As hypothesized, the altered bacterial distribution induced by KSK120 correlated with a block in C. trachomatis infectivity. Our data suggest that the compound targets the glucose-6-phosphate (G-6P) metabolism pathway of C. trachomatis, supporting previous indications that G-6P metabolism is critical for C. trachomatis infectivity. Thus, KSK120 may be a useful tool to study chlamydial glucose metabolism and has the potential to be used in the treatment of C. trachomatis infections.