bluuebunny/crossref_metadata_2025_split huggingface dataset:
A conformational switch controls cell wall‐remodelling enzymes required for bacterial cell division
Authors: Yang Desirée C. , Tan Kemin , Joachimiak Andrzej , Bernhardt Thomas G. 
Published: June 2012

SummaryRemodelling of the peptidoglycan (PG) exoskeleton is intimately tied to the growth and division of bacteria. Enzymes that hydrolyse PG are critical for these processes, but their activities must be tightly regulated to prevent the generation of lethal breaches in the PG matrix. Despite their importance, the mechanisms regulating PG hydrolase activity have remained elusive. Here we investigate the control of cell division hydrolases called amidases (AmiA, AmiB and AmiC) required for Escherichia coli cell division. Poorly regulated amiB mutants were isolated encoding lytic AmiB variants with elevated basal PG hydrolase activities in vitro. The structure of an AmiB orthologue was also solved, revealing that the active site of AmiB is occluded by a conserved alpha helix. Strikingly, most of the amino acid substitutions in the lytic AmiB variants mapped to this domain and are predicted to disrupt its interaction with the active site. Our results therefore support a model in which cell separation is stimulated by the reversible relief of amidase autoinhibition governed by conserved subcomplexes within the cytokinetic ring. Analogous conformational control mechanisms are likely to be part of a general strategy used to control PG hydrolases present within multienzyme PG‐remodelling machines.
Refining the criterion for an abnormal Integrated Relaxation Pressure in esophageal pressure topography based on the pattern of esophageal contractility using a classification and regression tree model
Authors: Lin Z. , Kahrilas P. J. , Roman S. , Boris L. , Carlson D. , Pandolfino J. E. 
Published: June 2012

AbstractBackground  The Integrated Relaxation Pressure (IRP) is the esophageal pressure topography (EPT) metric used for assessing the adequacy of esophagogastric junction (EGJ) relaxation in the Chicago Classification of motility disorders. However, because the IRP value is also influenced by distal esophageal contractility, we hypothesized that its normal limits should vary with different patterns of contractility.Methods  Five hundred and twenty two selected EPT studies were used to compare the accuracy of alternative analysis paradigms to that of a motility expert (the ‘gold standard’). Chicago Classification metrics were scored manually and used as inputs for MATLAB™ programs that utilized either strict algorithm‐based interpretation (fixed abnormal IRP threshold of 15 mmHg) or a classification and regression tree (CART) model that selected variable IRP thresholds depending on the associated esophageal contractility.Key Results  The sensitivity of the CART model for achalasia (93%) was better than that of the algorithm‐based approach (85%) on account of using variable IRP thresholds that ranged from a low value of >10 mmHg to distinguish type I achalasia from absent peristalsis to a high value of >17 mmHg to distinguish type III achalasia from distal esophageal spasm. Additionally, type II achalasia was diagnosed solely by panesophageal pressurization without the IRP entering the algorithm.Conclusions & Inferences  Automated interpretation of EPT studies more closely mimics that of a motility expert when IRP thresholds for impaired EGJ relaxation are adjusted depending on the pattern of associated esophageal contractility. The range of IRP cutoffs suggested by the CART model ranged from 10 to 17 mmHg.
Comparison of small‐bowel motility of the human jejunum and ileum
Authors: Seidl H. , Gundling F. , Pfeiffer A. , Pehl C. , Schepp W. , Schmidt T. 
Published: June 2012

AbstractBackground  Knowledge about human cyclic fasting motility (MMC) and the postprandial response is mostly based on manometric findings in the upper small intestine. Hardly any data exist on human ileal motility, as the acquisition of data has been limited by methodological concerns.The aim was to study human jejunal and ileal motility in an optimized manometric setting.Methods  Solid‐state 24‐h‐manometry was performed in the jejunum and ileum of healthy individuals, applying a strict protocol for fasting, resting, and the consumption of a standardized meal. Both visual qualitative and validated computerized quantitative contraction and propagation analysis were performed.Key Results  MMC occurs in similar frequency in the jejunum and ileum, but it was significantly shorter in the jejunum at night. By many characteristics, ileal motility was less intense and propagative than jejunal: less migrating clustered contractions, and slower propagation velocity and shorter distance in phases II and III, and postprandially – possibly slowing and enhancing nutrient absorption. Prolonged propagated contractions in some individuals were identified as a unique ileal propulsive pattern. Postprandially, an abrupt conversion to a digestive motility pattern occurs simultaneously independent of the region.Conclusions & Inferences  We found similar basic phenomena of fasting and postprandial motility in the jejunum and ileum of healthy humans. However, different calibration of propagative and contractile activity and special motor events in the ileum may account for a different physiological role in digestion. Future studies of small‐bowel motility in healthy and diseased subjects focusing on segmental differences of proximal and distal intestine may be rewarded.
Unique roles of Schistosoma japonicum protein Sj16 to induce IFN‐γ and IL‐10 producing CD4+CD25+ regulatory T cells in vitro and in vivo
Authors: SUN X. J. , LI R. , SUN X. , ZHOU Y. , WANG Y. , LIU X. J. , LU Q. , ZHOU C. L. , WU Z. D. 
Published: June 2012

SummaryVarious proteins are expressed during different stages of schistosome development that are essential for cercarial penetration of vertebrate skin and evasion of host immune response. CD4+CD25+ regulatory T cells are important in modulating immune responses towards helminth infections. Schistosoma japonicum protein Sj16 present in the secretions of schistosomula has been shown to have anti‐inflammatory effects; however, it is uncertain whether Sj16 can induce CD4+CD25+ regulatory T cells to participate in the regulation of early infection. In this study, we demonstrate a relationship between recombinant Sj16 (rSj16) and the induction of CD4+CD25+ Foxp3+ regulatory T cells. An increase in CD4+CD25+ T cells was observed both in splenic cells from mice injected with rSj16 and the cells pretreated with rSj16, respectively. The induced CD4+CD25+ T cells suppressed CD4+CD25− T‐cell proliferation; furthermore, IFN‐γ and IL‐10 released from rSj16‐stimulated cells contribute to this suppression. Additionally, rSj16‐treated bone marrow dendritic cells (BMDCs) demonstrate an immature phenotype and play a role in the conversion of CD4+CD25− T cells into suppressive CD4+CD25+ regulatory T cells. Our study identified a new CD4+CD25+ T‐cell population that induced by rSj16 and suggests that an IFN‐γ‐biased microenvironment during early infection of schistosome may favour the establishment of infection.
Discovery of a multigene family of aquaporin silicon transporters in the primitive plant Equisetum arvense
Authors: Grégoire Caroline , Rémus‐Borel Wilfried , Vivancos Julien , Labbé Caroline , Belzile François , Bélanger Richard R. 
Published: June 2012

SummaryPlants benefit greatly from silicon (Si) absorption provided that they contain Si transporters. The latter have recently been identified in the roots of some higher plants known to accumulate high concentrations of Si, and all share a high level of sequence identity. In this study, we searched for transporters in the primitive vascular plant Equisetum arvense (horsetail), which is a valuable but neglected model plant for the study of Si absorption, as it has one of the highest Si concentrations in the plant kingdom. Our initial attempts to identify Si transporters based on sequence homology with transporters from higher plants proved unsuccessful, suggesting a divergent structure or property in horsetail transporters. Subsequently, through sequencing of the horsetail root transcriptome and a search using amino acid sequences conserved in plant aquaporins, we were able to identify a multigene family of aquaporin Si transporters. Comparison of known functional domains and phylogenetic analysis of sequences revealed that the horsetail proteins belong to a different group than higher‐plant Si transporters. In particular, the newly identified proteins contain a STAR pore as opposed to the GSGR pore common to all previously identified Si transporters. In order to determine its functionality, the proteins were heterologously expressed in both Xenopus oocytes and Arabidopsis, and the results showed that the horsetail proteins are extremely efficient a transporting Si. These findings offer new insights into the elusive properties of Si and its absorption by plants.
The Snf1‐related protein kinases SnRK2.4 and SnRK2.10 are involved in maintenance of root system architecture during salt stress
Authors: McLoughlin Fionn , Galvan‐Ampudia Carlos S. , Julkowska Magdalena M. , Caarls Lotte , van der Does Dieuwertje , Laurière Christiane , Munnik Teun , Haring Michel A. , Testerink Christa 
Published: June 2012

SummaryThe sucrose non‐fermenting‐1‐related protein kinase 2 (SnRK2) family represents a unique family of plant‐specific protein kinases implicated in cellular signalling in response to osmotic stress. In our studies, we observed that two class 1 SnRK2 kinases, SnRK2.4 and SnRK2.10, are rapidly and transiently activated in Arabidopsis roots after exposure to salt. Under saline conditions, snrk2.4 knockout mutants had a reduced primary root length, while snrk2.10 mutants exhibited a reduction in the number of lateral roots. The reduced lateral root density was found to be a combinatory effect of a decrease in the number of lateral root primordia and an increase in the number of arrested lateral root primordia. The phenotypes were in agreement with the observed expression patterns of genomic yellow fluorescent protein (YFP) fusions of SnRK2.10 and ‐2.4, under control of their native promoter sequences. SnRK2.10 was found to be expressed in the vascular tissue at the base of a developing lateral root, whereas SnRK2.4 was expressed throughout the root, with higher expression in the vascular system. Salt stress triggered a rapid re‐localization of SnRK2.4–YFP from the cytosol to punctate structures in root epidermal cells. Differential centrifugation experiments of isolated Arabidopsis root proteins confirmed recruitment of endogenous SnRK2.4/2.10 to membranes upon exposure to salt, supporting their observed binding affinity for the phospholipid phosphatidic acid. Together, our results reveal a role for SnRK2.4 and ‐2.10 in root growth and architecture in saline conditions.
Outcome in polytraumatized patients with and without brain injury
Authors: GROSS T. , SCHÜEPP M. , ATTENBERGER C. , PARGGER H. , AMSLER F. 
Published: June 2012

BackgroundTo investigate the long‐term outcome in polytrauma victims with traumatic brain injury (TBI) and without traumatic brain injury (NTBI).MethodsCohort study based on prospectively collected data. Evaluation of functional outcome and quality of life at least 2 years (median 2.5) following trauma in 111 survivors [39.5 ± 20.9 years; injury severity score (ISS) 27.9 ± 8.2; TBI: n = 45; NTBI: n = 66] out of a total of 211 consecutive multiply‐injured patients with an ISS > 16, all primarily admitted to the intensive care unit.ResultsSignificantly fewer TBI patients lived independently compared with NTBI patients (71% vs. 95%; P < 0.001). TBI patients showed a higher decrease in their capacity to work compared with NTBI patients (P < 0.002). Both study groups experienced a significantly reduced long‐term outcome in comparison with pre‐injury level in all dimensions of the short form (SF)‐36. Following stepwise logistic regression, the mental sum component of the SF‐36 and the Nottingham Health Profile discriminated independently between TBI and NTBI patients (R
2 = 0.219; P < 0.001).ConclusionMore than 2 years after injury, polytraumatized patients with and without TBI suffer from a reduction in functional outcome and quality of life, but TBI patients are doing importantly worse. Any comparison of trauma patient cohorts should consider these differences between TBI and NTBI patients. Given their discriminatory potential, the sensitivity of self‐reported measures needs further affirmation with neuropsychological assessments.
Vigilance Decreases with Time at Loafing Sites in Gulls (Larus spp.)
Authors: Beauchamp Guy , Ruxton Graeme D. 
Published: June 2012

AbstractUnderstanding how animals partition effort between vigilance for predators and other conflicting activities has been a mainstay of animal behaviour research. Classical theories implicitly assume that animals alternate between high and low vigilance states over short timescales, but that average effort invested in vigilance is constant over an extended bout of such alternations. However, one recent model suggests that vigilance should be adjusted dynamically to short‐term changes in the perception of predation risk and would tend to decrease with time. Indeed, as time passes by without disturbances, perception of the need for vigilance should decrease and prey animals may allocate more time to competing activities. Here, we examined how the proportion of sleeping gulls (Larus spp.) in loafing groups changed over time. Sleeping gulls can only maintain low levels of vigilance against external threats (compared to alert individuals), and we predicted that the proportion of sleeping gulls at loafing sites should increase over time when no disturbances occur. Statistically significant changes in the proportion of sleeping gulls as a function of time occurred in the majority of sequences and an increase was observed significantly more often than predicted by chance alone. This temporal pattern cannot be caused by reduction in hunger levels because gulls are not feeding at loafing sites. The results indicate that vigilance can be adjusted dynamically in response to short‐term temporal changes in the perception of predation risk.
Chronological vs. Physiological Age as Determinants of Mating Decisions: Studies on Female Choice Over Lifespan in An Acoustic Moth
Authors: Ligout Séverine , Munier Damien , Marquereau Lucie , Greenfield Michael D. 
Published: June 2012

AbstractLife history theory predicts that females may adjust the selectivity expressed in mate choice as they age. Particularly in cases where time is limiting, females are expected to reduce selectivity and thereby avoid losing a terminal mating opportunity. Some evidence for this reduction has been found in vertebrates and long‐lived insects, and several recent findings show that it may also exist in insects with very short adult longevities. Theory also predicts that behavioural adjustments should respond to remaining longevity (physiological age) rather than chronological age, but very little information relevant to this issue exists. We studied age‐related changes in mating behaviour in an acoustic moth species (Achroia grisella; Lepidoptera: Pyralidae) in which females choose males based on the intensity, rhythm and other temporal features of the male song, with the objective of determining whether observed adjustments reflect chronological or physiological age. In accordance with theory, we found that females became less selective in their evaluation of male song rhythm as they aged and that this adjustment was predicted by physiological rather than chronological age. The reduction in selectivity may be due to decreased movement and searching, factors that can prevent a female from perceiving all of the male songs being broadcast locally in a complex environment where the transmission of some songs is blocked in some locations. We did not observe these age‐related effects in a simpler, open environment.
Gas Exchange of Five Warm‐Season Grain Legumes and their Susceptibility to Heat Stress
Authors: Herzog H. , Chai‐Arree W. 
Published: June 2012

AbstractObjective of this study was to compare the heat stress performance of four pulses from dry and hot areas (mungbeans, limabeans, and teparybeans and cowpeas) with that of soybeans. Two experiments were conducted in growth chambers, and data were pooled because results of both experiments were similar. Plants were raised up to flowering at 24/17 °C (day/night) and were then either exposed to these temperatures until maturity or stressed with 33/24 °C for 2 weeks starting at day 1 or 15 after onset of flowering (early vs. late stress). Before, during and after these stress intervals, gas exchange of representative upper leaves was examined; additionally, immediate effects of increasing leaf temperatures from 24 to 32 or 40 °C on chlorophyll fluorescence were assessed. Without heat stress rates of photosynthesis (Pn), and of transpiration (TR), stomatal and mesophyll conductance (gs, gm) and intrinsic transpiration efficiency (iTE) differed significantly among the five crops at each date. However, because of crop‐specific time‐courses ranking among unstressed crops was instable with time, so values were integrated or averaged over time. This procedure revealed high Pn potentials in mung‐ and teparybeans and high iTE values in limabeans compared to the other crops. Heat stress lowered Pn and gs considerably, but increased TR in all five crops. Relative lowering of Pn during heat stress displayed a crop‐specific pattern with limabeans being least susceptible to both early and late heat stress, while cowpeas were highly susceptible to early stress. Effects on Pn were mainly attributable to lowering of gs and only in part to gm. The latter was supported by very small changes (<10 %) of various chlorophyll fluorescence signals shortly after raising leaf temperature to 32 °C in all species. However, in limabeans, a decreased electron transport rate (e‐rate, −18 %) and an increased non‐photochemical quenching (QN, +16 %) pointed to an adaptive mechanism to avoid oxidative strains under heat. Leaf temperatures of 40 °C immediately provoked stronger changes in all fluorescence signals than 32 °C; substantial damages at 40 °C were indicated by effective quantum yield, photochemical quenching and ratio of fluorescence decrease in mungbeans and low ones in cowpeas and soybeans. Nevertheless, some adaptive responses of e‐rates and QN were observed in all crops and were most expressed in limabeans.
Large‐scale development of microsatellite markers in Nicotiana tabacum and construction of a genetic map of flue‐cured tobacco
Authors: Tong Zhijun , Yang Zemao , Chen Xuejun , Jiao Fangchan , Li Xuying , Wu Xingfu , Gao Yulong , Xiao Bingguang , Wu Weiren 
Published: June 2012

With 1 figure and 1 tableAbstractMolecular markers and genetic maps are useful tools for genetic research and molecular breeding. Although significant progress has been made recently on molecular marker development and genetic map construction in tobacco (Nicotiana tabacum), more efforts are still required to meet the needs of genetic research and breeding in this allotetraploid species. In this study, based on the expressed sequence tag (EST) data and genome sequence data of N. tabacum, we developed a total of 4886 simple sequence repeat (SSR) markers (including 1365 genomic SSRs and 3521 EST‐SSRs), which were functional in a set of eight tobacco varieties of four different types and were basically novel. Using these newly developed SSR markers as well as published SSR markers and a population of 207 double haploid (DH) lines derived from a cross between two flue‐cured tobacco varieties ‘Honghua Dajinyuan’ and ‘Hicks Broad Leaf’, we constructed a genetic map consisting of 611 SSR loci distributed on 24 tentative linkage groups and covering a total length of 1882.1 cM with an average distance of 3.1 cM between adjacent markers.
Expression of CYP26b1 and Related Retinoic Acid Signalling Molecules in Young, Peripubertal and Adult Dog Testis
Authors: Kasimanickam VR , Kasimanickam RK 
Published: June 2012

ContentsThe objective of the study was to elucidate mRNA expression of CYP26b1 (cytochrome P450, family 26, subfamily B, polypeptide 1) and signalling molecules ALDH1 (aldehyde dehydrogenase 1), CRABPII (cellular retinoic acid‐binding protein II), RARα (retinoic acid receptor alpha) and STRA8 (stimulated by retinoic acid gene 8) in dog testis from different post‐natal developmental ages. Testicular tissue samples were collected from medium‐sized mixed breed dogs at different ages such as young (<4 months; N = 4), peripubertal (4–8 months; N = 3) and adult (>8 months; N = 4) were used to evaluate relative mRNA expression. Genes of RA‐degrading enzyme CYP26b1, ALDH1 involved in RA synthesis and genes of carrier protein CRABPII involved in RA metabolism were turned on during the post‐natal testicular development in dogs. Their expression pattern differs at different developmental ages (p < 0.05), and the levels of mRNA expression were compensated towards a normal developmental response for the sexual maturity and continuous spermatogenesis. The mRNA expression of RARα, one of the RA receptors participates in RA signalling in connection to spermatogenesis, was recorded in young and adult stages at varying degree. STRA8 is one of the responsive genes with regard to meiosis, and this functional gene product was expressed in all ages with the changing level (p < 0.01). In summary, the expression pattern of RA signalling molecules differed from young to adult ages, and it is expected that these changes are to compensate towards a normal developmental response for the sexual maturity and continuous spermatogenesis.
Real‐time ultrasound guided placement of temporary internal jugular vein catheters: Assessment of technical success and complication rates in nephrology practice
Authors: AKOGLU HADIM , PISKINPASA SERHAN , YENIGUN EZGI C , OZTURK RAMAZAN , DEDE FATIH , ODABAS ALI R 
Published: June 2012

ABSTRACT:Aim:  Internal jugular vein (IJV) catheterization is often required to gain access for haemodialysis. Use of ultrasound guidance has reduced the complication rates of this procedure. We hypothesized that nephrologists may perform IJV cannulation with a high technical success and low immediate complication rates under real‐time ultrasound guidance.Methods:  We prospectively analyzed 323 patients (186 male, 137 female) who underwent IJV cannulation with real‐time ultrasound guidance. The number of needle punctures, technical success, the time between injection of local anaesthetic and entry into the IJV, and immediate complications were recorded. Patients with a history of multiple catheter insertions, previous difficulties during catheterization, poor compliance, obesity, impaired consciousness, skeletal deformity, disorder of haemostasis were regarded as high‐risk group.Results:  Cannulation of IJV was achieved in all patients. Of the 323 catheters, 125 (38.7%) were placed in high‐risk patients. Average number of puncture was 1.26 (range, 1–4). IJV was entered on the first attempt in 261 (80.8%) patients. Only ten complications (10/323, 3.2%) developed; five (2.5%) in the normal‐risk group, and five (4.0%) in the high‐risk group. Cannulation of IJV took a longer time in the high‐risk group than in the normal‐risk group. The number of needle punctures, percent of successful cannulation on the first attempt, and the frequency of complications were similar between the high‐ and normal‐risk groups.Conclusions:  Cannulation of IJV under real‐time ultrasound guidance is very safe with high technical success rates. Nephrologists can use this technique with ease and with minimal complications in normal‐ and high‐risk patients.