bluuebunny/crossref_metadata_2025_split huggingface dataset:
Regulation of Transport in the Connecting Tubule and Cortical Collecting Duct
Authors: Staruschenko Alexander 
Published: March 2012

AbstractThe central goal of this overview article is to summarize recent findings in renal epithelial transport, focusing chiefly on the connecting tubule (CNT) and the cortical collecting duct (CCD). Mammalian CCD and CNT are involved in fine‐tuning of electrolyte and fluid balance through reabsorption and secretion. Specific transporters and channels mediate vectorial movements of water and solutes in these segments. Although only a small percent of the glomerular filtrate reaches the CNT and CCD, these segments are critical for water and electrolyte homeostasis since several hormones, for example, aldosterone and arginine vasopressin, exert their main effects in these nephron sites. Importantly, hormones regulate the function of the entire nephron and kidney by affecting channels and transporters in the CNT and CCD. Knowledge about the physiological and pathophysiological regulation of transport in the CNT and CCD and particular roles of specific channels/transporters has increased tremendously over the last two decades. Recent studies shed new light on several key questions concerning the regulation of renal transport. Precise distribution patterns of transport proteins in the CCD and CNT will be reviewed, and their physiological roles and mechanisms mediating ion transport in these segments will also be covered. Special emphasis will be given to pathophysiological conditions appearing as a result of abnormalities in renal transport in the CNT and CCD. © 2012 American Physiological Society.Compr Physiol2:1541‐1584, 2012.
Analysis of current–voltage characteristics for memristive elements in pattern recognition systems
Authors: Corinto Fernando , Ascoli Alon , Gilli Marco 
Published: March 2012

SUMMARYA topologically simple memristive‐based oscillatory network showing a wide plethora of dynamical behaviors may be a good candidate for the realization of innovative oscillatory associative and dynamic memories for the recognition of spatial–temporal synchronization states. The design of such pattern recognition systems may not leave aside a preliminary thorough investigation of the nonlinear dynamics of the network and its basic components. In a synchronization scenario with almost‐sinusoidal oscillations, each of the memristive elements used in the cells of the network under consideration features an unusual current–voltage behavior. This manuscript models the linear circuitry and the memristive element in each cell so as to capture the observed dynamics and then presents an analytical study explaining the quantitative dependence of memristive current–voltage behavior on excitation amplitude–angular frequency ratio and on initial condition on the system state. This work leads to the first rigorous classification of all possible current–voltage characteristics for a sine‐wave voltage‐driven memristive element. This analytical study shall pave way towards a better understanding of the complex and still unexplored dynamical properties of this nonlinear device, whose distinct features could improve the capabilities of future‐generation pattern recognition systems. Copyright © 2012 John Wiley & Sons, Ltd.
Altered neutrophil maturation patterns that limit identification of myelodysplastic syndromes
Authors: Monaghan Sara A. , Surti Urvashi , Doty Ketah , Craig Fiona E. 
Published: March 2012

AbstractBackground:Altered neutrophil maturation patterns have been reported useful for identification of myelodysplastic syndromes (MDS).Methods:Neutrophil maturation patterns based on CD11b, CD13, and CD16 were visually and numerically evaluated in 19 control, 23 MDS, 37 nondiagnostic for MDS (NDM) specimens, and 19 also processed 1 and 2 days subsequently.Results:In contrast to maturation patterns illustrated previously by others as “normal,” 84% of controls displayed diminished acquisition of CD16, imparting a contracted appearance. Such divergence from published “normal” patterns was usually mild‐moderate, considered nonspecific, and associated with delayed processing: longer intervals between collection and processing (median 20.5 vs. 5.2 h), and following 1 and 2 days delay. Findings restricted to nonspecific contraction were found in 56% MDS and 78% NDM specimens. Evaluation for aberrant patterns was still performed with mild‐moderate contraction present, but concern for over interpretation led to use of an equivocal‐aberrant category. Nine cases had aberrant or equivocal‐aberrant patterns (seven MDS, two NDM) with distinct visual alterations that differed from nonspecific contraction and had numerical evidence for a left shift: myeloblasts increased (67%) and least mature neutrophils (CD11b‐/low, CD16‐/low) increased (78%). Although evidence for a left shift was associated with MDS, it was also seen in NDM specimens with a synchronous left shift.Conclusions:Neutrophil maturation patterns that diverge from previously illustrated “normal” patterns, not specific for MDS, may be common in some settings. Laboratories seeking to implement FC evaluation for MDS must determine which findings have sufficient specificity for MDS within their own practice and patient population. © 2012 International Clinical Cytometry Society
Psychosocial risk factors of loss of control eating in primary school children: A retrospective case‐control study
Authors: Hartmann Andrea Sabrina , Czaja Julia , Rief Winfried , Hilbert Anja 
Published: March 2012

AbstractObjective:To provide a comprehensive investigation of the retrospective correlates of loss of control (LOC) over eating in children close to the onset of their first LOC eating episodes.Method:A community‐based, case‐control design was used to compare matched groups of 60 children with and without LOC eating. Retrospective correlates were assessed using a child‐adapted version of the Oxford Risk Factor Interview.Results:Children with LOC eating revealed greater levels of exposure to parental problems, (e.g., underinvolvement, arguments, and depression of family members) and dieting‐related risk factors than children without LOC eating. Predictors of LOC eating were risk correlates parental underinvolvement, and critical comments by the family and the critical life event change of school.Discussion:Results underline the influence of parental behavior and the impact of dieting behavior on the development of non‐normative eating in middle childhood. © 2012 by Wiley Periodicals, Inc. (Int J Eat Disord 2012; 45:751–758)
Efficient and General Protocol for Sonogashira Cross‐Coupling Reactions of Maleimides
Authors: Souffrin Agathe , Croix Cécile , Viaud‐Massuard Marie‐Claude 
Published: March 2012

AbstractMaleimides are involved for the first time in Sonogashira cross‐coupling reactions. Sonogashira conditions have been developed to allow subsequent coupling of various terminal alkynes at room temperature in moderate to excellent yields. These results open the way to innovative synthesis strategies for various difunctionalized maleimide derivatives.
Total Syntheses of D‐xylo‐ and D‐arabino‐Phytosphingosine Based on the Syntheses of Chiral 1,3‐Oxazines
Authors: Mu Yu , Jin Tian , Kim Gun‐Woo , Kim Jin‐Seok , Kim Sung‐Soo , Tian Yong‐Shou , Oh Chang‐Young , Ham Won‐Hun 
Published: March 2012

AbstractAn efficient, stereocontrolled, and short synthetic method for the preparation D‐xylo‐ and D‐arabino‐phytosphingsine was achieved utilizing chiral oxazines. The key features of this strategy are the stereoselective intramolecular oxazine formation catalyzed by palladium(0) and an intermolecular olefin cross‐metathesis reaction.
Kir4.1 channels mediate a depolarization of hippocampal astrocytes under hyperammonemic conditions in situ
Authors: Stephan Jonathan , Haack Nicole , Kafitz Karl W. , Durry Simone , Koch Daniel , Hochstrate Peter , Seifert Gerald , Steinhäuser Christian , Rose Christine R. 
Published: March 2012

AbstractIncreased ammonium (NH4
+) concentration in the brain is the prime candidate responsible for hepatic encephalopathy (HE), a serious neurological disorder caused by liver failure and characterized by disturbed glutamatergic neurotransmission and impaired glial function. We investigated the mechanisms of NH4
+‐induced depolarization of astrocytes in mouse hippocampal slices using whole‐cell patch‐clamp and potassium‐selective microelectrodes. At postnatal days (P) 18–21, perfusion with 5 mM NH4
+ evoked a transient increase in the extracellular potassium concentration ([K+]o) by about 1 mM. Astrocytes depolarized by on average 8 mV and then slowly repolarized to a plateau depolarization of 6 mV, which was maintained during NH4
+ perfusion. In voltage‐clamped astrocytes, NH4
+ induced an inward current and a reduction in membrane resistance. Amplitudes of [K+]o transients and astrocyte depolarization/inward currents increased from P3–4 to P18–21. Perfusion with 100 μM Ba2+ did not alter [K+]o transients but strongly reduced both astrocyte depolarization and inward currents. NH4
+‐induced depolarization and inward currents were also virtually absent in slices from Kir4.1 −/− mice, while [K+]o transients were unaltered. Blocking Na+/K+‐ATPase with ouabain caused an immediate and complex increase in [K+]o. Taken together, our results are in agreement with the hypothesis that reduced uptake of K+ by the Na+, K+‐ATPase in the presence of NH4
+ disturbs the extracellular K+ homeostasis. Furthermore, astrocytes depolarize in response to the increase in [K+]o and by influx of NH4
+ through Kir4.1 channels. The depolarization reduces the astrocytes' capacity for channel‐mediated flux of K+ and for uptake of glutamate and might hereby contribute to the pathology of HE. © 2012 Wiley Periodicals, Inc.
Altered resting‐state connectivity during interictal generalized spike‐wave discharges in drug‐naïve childhood absence epilepsy
Authors: Yang Tianhua , Luo Cheng , Li Qifu , Guo Zhiwei , Liu Ling , Gong Qiyong , Yao Dezhong , Zhou Dong 
Published: March 2012

AbstractPurpose: To investigate the intrinsic brain connections at the time of interictal generalized spike‐wave discharges (GSWDs) to understand their mechanism of effect on brain function in untreated childhood absence epilepsy (CAE). Methods: The EEG‐functional MRI (fMRI) was used to measure the resting state functional connectivity during interictal GSWDs in drug‐naïve CAE, and three different brain networks—the default mode network (DMN), cognitive control network (CCN), and affective network (AN)—were investigated. Results: Cross‐correlation functional connectivity analysis with priori seed revealed decreased functional connectivity within each of these three networks in the CAE patients during interictal GSWDS. It included precuneus‐dorsolateral prefrontal cortex (DLPFC), dorsomedial prefrontal cortex (DMPFC), and inferior parietal lobule in the DMN; DLPFC‐inferior frontal junction (IFJ), and pre‐supplementary motor area (pre‐SMA) subregions connectivity disruption in CCN; ACC‐ventrolateral prefrontal cortex (VLPFC) and DMPFC in AN; There were also some regions, primarily the parahippcampus, paracentral in AN, and the left frontal mid orb in the CCN, which showed increased connectivity. Conclusions: The current findings demonstrate significant alterations of resting‐state networks in drug naïve CAE subjects during interictal GSWDs and interictal GSWDs can cause dysfunction in specific networks important for psychosocial function. Impairment of these networks may cause deficits both during and between seizures. Our study may contribute to the understanding of neuro‐pathophysiological mechanism of psychosocial function impairments in patients with CAE. Hum Brain Mapp, 2013. © 2012 Wiley Periodicals, Inc.
Representation and propagation of epileptic activity in absences and generalized photoparoxysmal responses
Authors: Moeller Friederike , Muthuraman Muthuraman , Stephani Ulrich , Deuschl Günther , Raethjen Jan , Siniatchkin Michael 
Published: March 2012

AbstractAlthough functional imaging studies described networks associated with generalized epileptic activity, propagation patterns within these networks are not clear. In this study, electroencephalogram (EEG)‐based coherent source imaging dynamic imaging of coherent sources (DICS) was applied to different types of generalized epileptiform discharges, namely absence seizures (10 patients) and photoparoxysmal responses (PPR) (eight patients) to describe the representation and propagation of these discharges in the brain. The results of electrical source imaging were compared to EEG‐functional magnetic resonance imaging (fMRI) which had been obtained from the same data sets of simultaneous EEG and fMRI recordings. Similar networks were described by DICS and fMRI: (1) absence seizures were associated with thalamic involvement in all patients. Concordant results were also found for brain areas of the default mode network and the occipital cortex. (2) Both DICS and fMRI identified the occipital, parietal, and the frontal cortex in a network associated with PPR. (3) However, only when PPR preceded a generalized tonic‐clonic seizure, the thalamus was involved in the generation of PPR as shown by both imaging techniques. Partial directed coherence suggested that during absences, the thalamus acts as a pacemaker while PPR could be explained by a cortical propagation from the occipital cortex via the parietal cortex to the frontal cortex. In conclusion, the electrical source imaging is not only able to describe similar neuronal networks as revealed by fMRI, including deep sources of neuronal activity such as the thalamus, but also demonstrates interactions interactions within these networks and sheds light on pathogenetic mechanisms of absence seizures and PPR. Hum Brain Mapp, 2013. © 2012 Wiley Periodicals, Inc.
Dynamic brain structural changes after left hemisphere subcortical stroke
Authors: Fan Fengmei , Zhu Chaozhe , Chen Hai , Qin Wen , Ji Xunming , Wang Liang , Zhang Yujin , Zhu Litao , Yu Chunshui 
Published: March 2012

AbstractThis study aimed to quantify dynamic structural changes in the brain after subcortical stroke and identify brain areas that contribute to motor recovery of affected limbs. High‐resolution structural MRI and neurological examinations were conducted at five consecutive time points during the year following stroke in 10 patients with left hemisphere subcortical infarctions involving motor pathways. Gray matter volume (GMV) was calculated using an optimized voxel‐based morphometry technique, and dynamic changes in GMV were evaluated using a mixed‐effects model. After stroke, GMV was decreased bilaterally in brain areas that directly or indirectly connected with lesions, which suggests the presence of regional damage in these “healthy” brain tissues in stroke patients. Moreover, the GMVs of these brain areas were not correlated with the Motricity Index (MI) scores when controlling for time intervals after stroke, which indicates that these structural changes may reflect an independent process (such as axonal degeneration) but cannot affect the improvement of motor function. In contrast, the GMV was increased in several brain areas associated with motor and cognitive functions after stroke. When controlling for time intervals after stroke, only the GMVs in the cognitive‐related brain areas (hippocampus and precuneus) were positively correlated with MI scores, which suggests that the structural reorganization in cognitive‐related brain areas may facilitate the recovery of motor function. However, considering the small sample size of this study, further studies are needed to clarify the exact relationships between structural changes and recovery of motor function in stroke patients. Hum Brain Mapp, 2013. © 2012 Wiley Periodicals, Inc.
Adult‐born hippocampal neurons promote cognitive flexibility in mice
Authors: Burghardt Nesha S. , Park Eun Hye , Hen René , Fenton André A. 
Published: March 2012

AbstractThe hippocampus is involved in segregating memories, an ability that utilizes the neural process of pattern separation and allows for cognitive flexibility. We evaluated a proposed role for adult hippocampal neurogenesis in cognitive flexibility using variants of the active place avoidance task and two independent methods of ablating adult‐born neurons, focal X‐irradiation of the hippocampus, and genetic ablation of glial fibrillary acidic protein positive neural progenitor cells, in mice. We found that ablation of adult neurogenesis did not impair the ability to learn the initial location of a shock zone. However, when conflict was introduced by switching the location of the shock zone to the opposite side of the room, irradiated and transgenic mice entered the new shock zone location significantly more than their respective controls. This impairment was associated with increased upregulation of the immediate early gene Arc in the dorsal dentate gyrus, suggesting a role for adult neurogenesis in modulating network excitability and/or synaptic plasticity. Additional experiments revealed that irradiated mice were also impaired in learning to avoid a rotating shock zone when it was added to an initially learned stationary shock zone, but were unimpaired in learning the identical simultaneous task variant if it was their initial experience with place avoidance. Impaired avoidance could not be attributed to a deficit in extinction or an inability to learn a new shock zone location in a different environment. Together these results demonstrate that adult neurogenesis contributes to cognitive flexibility when it requires changing a learned response to a stimulus‐evoked memory. © 2012 Wiley Periodicals, Inc.
Synaptic underpinnings of altered hippocampal function in glutaminase‐deficient mice during maturation
Authors: Gaisler‐Salomon Inna , Wang Yvonne , Chuhma Nao , Zhang Hong , Golumbic Yaela N. , Mihali Andra , Arancio Ottavio , Sibille Etienne , Rayport Stephen 
Published: March 2012

AbstractGlutaminase‐deficient mice (GLS1 hets), with reduced glutamate recycling, have a focal reduction in hippocampal activity, mainly in CA1, and manifest behavioral and neurochemical phenotypes suggestive of schizophrenia resilience. To address the basis for the hippocampal hypoactivity, we examined synaptic plastic mechanisms and glutamate receptor expression. Although baseline synaptic strength was unaffected in Schaffer collateral inputs to CA1, we found that long‐term potentiation was attenuated. In wild‐type (WT) mice, GLS1 gene expression was highest in the hippocampus and cortex, where it was reduced by about 50% in GLS1 hets. In other brain regions with lower WT GLS1 gene expression, there were no genotypic reductions. In adult GLS1 hets, NMDA receptor NR1 subunit gene expression was reduced, but not AMPA receptor GluR1 subunit gene expression. In contrast, juvenile GLS1 hets showed no reductions in NR1 gene expression. In concert with this, adult GLS1 hets showed a deficit in hippocampal‐dependent contextual fear conditioning, whereas juvenile GLS1 hets did not. These alterations in glutamatergic synaptic function may partly explain the hippocampal hypoactivity seen in the GLS1 hets. The maturity‐onset reduction in NR1 gene expression and in contextual learning supports the premise that glutaminase inhibition in adulthood should prove therapeutic in schizophrenia. © 2012 Wiley Periodicals, Inc.
Role of transformational leadership in effective organizational knowledge creation practices: Mediating effects of employees' work engagement
Authors: Hoon Song Ji , Kolb Judith A. , Hee Lee Ung , Kyoung Kim Hye 
Published: March 2012

AbstractEngagement as an area of increasing interest has been discussed in terms of a wide array of organizational policies, practices, and outcomes. This study focuses on a specific aspect of work engagement and its relationship with leadership practices and the outcome of knowledge creation. The mediating effect of employees' work engagement level was assessed to explain the relationship between transformational leadership and organizational knowledge creation practices in the Korean business context. A total of 432 cases were collected from Korean for‐profit organizations. Hierarchical multiple regression analysis and structural equation modeling were used along with basic descriptive analysis and interconstruct correlation analysis to examine the structural relationships and the mediating effect among the constructs. Results found transformational leadership to be a statistically significant construct that has an impact on employees' work engagement and organizational knowledge creation practices. Additionally, employees' work engagement was found to be a statistically significant mediator that explains the relationship between transformational leadership and organizational knowledge creation practices.
Evolution of approaches in conducting total diet studies
Authors: Betsy A. , Sudershan Rao V. , Polasa K. 
Published: March 2012

ABSTRACTOne of the main routes of human exposure to contaminants is through food. To assess the health impact, it is necessary to determine the levels of contaminants in foods and evaluate the exposure estimates. Many countries regularly conduct total diet studies as a method of assessing the exposure of the population to various contaminants present in foods. It is a comprehensive approach and is based on determination of contaminants in foods. The risk assessment is done by taking into account the actual quantity consumed by specific age–sex groups of a population. The approach has developed through multiple changes since its inception. This article aims to review and summarize the changes that have occurred in different countries. Some of the attempts include the addition of analytes and the use of sophisticated instrumentation in conjunction with better extraction and types of food commodities. The present analytical methods have reduced the limits of detection for many analytes in many food matrices, making this approach much more accurate and sensitive. Copyright © 2012 John Wiley & Sons, Ltd.
Gene expression profiling reveals potential key pathways involved in pyrazinamide‐mediated hepatotoxicity in Wistar rats
Authors: Zhang Yun , Jiang Zhenzhou , Su Yijing , Chen Mi , Li Fu , Liu Li , Sun Lixin , Wang Yun , Zhang Shuang , Zhang Luyong 
Published: March 2012

ABSTRACTPyrazinamide (PZA) is an important sterilizing prodrug that shortens the duration of tuberculosis therapy. However, hepatotoxicity has been reported during clinical trials investigating PZA. To determine the hepatotoxic effects of PZA in vivo and to further investigate the underlying cellular mechanism, we profiled the gene expression patterns of PZA‐treated rat livers by microarray analysis. Wistar rats of both sexes were orally administered PZA at doses of 0.5, 1.0 and 2.0 g kg−1 for 28 days. Body weight, absolute and relative liver weight, biochemical analysis, histopathology, oxidative stress parameters in liver homogenates and changes in global transcriptomic expression were evaluated to study the hepatotoxic effects of PZA. Our results confirm the dose‐dependent and sex‐related hepatotoxicity of PZA. Female rats were more sensitive to PZA‐induced hepatotoxicity than males. Furthermore, changes in the activity of major antioxidant enzymes and nonenzymatic antioxidants (superoxide dismutase, total antioxidant capacity, glutathione and malondialdehyde), indicating the development of oxidative stress, were more significant in the PZA‐treated group. PZA‐induced gene expression changes were related to pathways involved in drug metabolism, peroxisome proliferator‐activated receptor (PPAR) signaling, oxidative stress and apoptosis. Real‐time polymerase chain reaction confirmed the regulation of selected genes involved in PZA‐hepatotoxicity (Ephx1, Cyp2b1, Gstm1, Gstp1, Fabp7, Acaa1, Cpt‐1b, Cyp8b1, Hmox1 and Ntrk1). We observed for the first time that these genes have effects on PZA‐induced hepatotoxicity. In addition, drug metabolism and PPAR signaling pathways may play an important role in PZA hepatotoxicity. Taken together, these findings will be useful for future PZA hepatotoxicity studies. Copyright © 2012 John Wiley & Sons, Ltd.