bluuebunny/crossref_metadata_2025_split huggingface dataset:
Both B1R and B2R act as intermediate signaling molecules in high glucose‐induced stimulation of glutamate uptake in ARPE cells
Authors: Lim Seul Ki , Han Ho Jae , Kim Kye Yeop , Park Soo Hyun 
Published: September 2009

AbstractBradykinin (BK) is a potent modulator of biological processes in the retina, and retinal pigment epithelial cells (RPE) and the regulation of glutamate are believed to be important in the pathogenesis of diabetic retinopathy. However, the mechanism by which BK regulates glutamate uptake in RPE cells in diabetic retinopathy is unknown. Here, we examined the involvement of BK receptors in high glucose‐induced dysfunction of glutamate uptake in human ARPE cells. High glucose stimulated glutamate uptake and the expression of excitatory amino acid transporter‐4 (EAAT4) mRNA, and these were blocked by treatment with small interfering RNA (siRNA) for BK1 receptor (B1R) and BK2 receptor (B2R), but not scrambled siRNA, supporting an involvement of B1R and B2R in this process. High glucose‐stimulated glutamate uptake was also blocked by the B1R antagonist [des‐Arg10]‐HOE 140 and the B2R antagonist HOE 140. High glucose increased B1R and B2R mRNA and protein expression in a time‐dependent manner, increased B1R and B2R translocation from the cytosol to the nucleus, and stimulated kininogen, kallikrein, and kininase I mRNA expression. We examined whether BK receptors were involved in high glucose‐induced signaling pathways. High glucose stimulated arachidonic acid release, cytosolic phospholipase A2 and cyclooxygenase‐2 proteins, nuclear factor‐κB activation, and inhibitor‐κB activation; these events were blocked by treatment with B1R and B2R siRNAs, but not scrambled siRNA. In addition, high glucose‐induced stimulation of glutamate uptake was blocked by the cyclooxygenase‐2 inhibitors arachidonyl trifluoromethyl ketone, mepacrine, 5‐bromo‐2‐(4‐fluorophenyl)‐3‐[4‐(methyl‐sulfonyl)phenyl]‐thiophene, and N‐[2‐cyclohexyloxy‐4‐nitrophenyl] methane‐sulfonamide, and by the nuclear factor‐κB inhibitors pyrrolidine dithiocarbamate and SN‐50. J. Cell. Physiol. 221: 677–687, 2009. © 2009 Wiley‐Liss, Inc.
The hematopoietic stem cell niche: Low in oxygen but a nice place to be
Authors: Eliasson Pernilla , Jönsson Jan‐Ingvar 
Published: September 2009

AbstractThe enormous regenerative capacity of the blood system to sustain functionally mature cells are generated from highly proliferative, short‐lived progenitors, which in turn arise from a rare population of pluripotent and self‐renewing hematopoietic stem cells (HSC). In the bone marrow, these stem cells are kept in a low proliferative, relatively quiescent state in close proximity to stromal cells and osteoblasts, forming specialized niches. The interaction in particular to bone is crucial to prevent exhaustion of HSCs from uncontrolled cell‐cycle entry and to excessive proliferation. In addition, the niche and its components protect stem cells from stress, such as accumulation of reactive oxygen species and DNA damage. One of the key issues is to identify conditions to increase the number of HSCs, either in vivo or during ex vivo growth cultures. This task has been very difficult to resolve and most attempts have been unsuccessful. However, the mechanistic insights to HSC self‐renewal and preservation are gradually increasing and there is now hope that future research will enable scientists and clinicians to modulate the process. In this review, we will focus on the molecular mechanisms of self‐renewal and HSC maintenance in the light of novel findings that HSCs reside at the lowest end of an oxygen gradient. Hypoxia appears to regulate hematopoiesis in the bone marrow by maintaining important HSC functions, such as cell cycle control, survival, metabolism, and protection against oxidative stress. To improve the therapeutic expansion of HSCs we need to learn more about the molecular mechanisms of hypoxia‐mediated regulation. J. Cell. Physiol. 222:17–22, 2010. © 2009 Wiley‐Liss, Inc.
Mesenchymal stem cells in regenerative medicine: Opportunities and challenges for articular cartilage and intervertebral disc tissue engineering
Authors: Richardson Stephen M. , Hoyland Judith A. , Mobasheri Reza , Csaki Constanze , Shakibaei Mehdi , Mobasheri Ali 
Published: September 2009

AbstractDefects of load‐bearing connective tissues such as articular cartilage and intervertebral disc (IVD) can result from trauma, degenerative, endocrine, or age‐related disease. Current surgical and pharmacological options for the treatment of arthritic rheumatic conditions in the joints and spine are ineffective. Cell‐based surgical therapies such as autologous chondrocyte transplantation (ACT) have been in clinical use for cartilage repair for over a decade but this approach has shown mixed results. This review focuses on the potential of mesenchymal stem cells (MSCs) as an alternative to cells derived from patient tissues in autologous transplantation and tissue engineering. Here we discuss the prospects of using MSCs in regenerative medicine and summarize the advantages and disadvantages of these cells in articular cartilage and IVD tissue engineering. We discuss the conceptual and practical difficulties associated with differentiating and pre‐conditioning MSCs for subsequent survival in a physiologically harsh extracellular matrix, an environment that will be highly hypoxic, acidic, and nutrient deprived. Implanted MSCs will be exposed to traumatic physical loads and high levels of locally produced inflammatory mediators and catabolic cytokines. We also explore the potential of culture models of MSCs, fully differentiated cells and co‐cultures as “proof of principle” ethically acceptable “3Rs” models for engineering articular cartilage and IVD in vitro for the purpose of replacing the use of animals in arthritis research. J. Cell. Physiol. 222:23–32, 2010. © 2009 Wiley‐Liss, Inc.
A model for predicting pathologist's velocity profiles when navigating virtual slides
Authors: Gómez Francisco , Romero Eduardo 
Published: September 2009

AbstractNavigation through large microscopic images is a potential benefit for histology or pathology teaching, for improving the quality of diagnosis in pathology, or for communicating pathologists in some telemedicine applications. However, the size of this kind of images is prohibitive for navigation with conventional techniques. This article presents a soft computing model, which permits to anticipate the pathologist trajectories in diagnosis tasks when exploring virtual slides. The Bayesian strategy combines an offline model of a baseline pathologist knowledge (the prior) and a prediction online module (the likelihood) that captures a particular pathologist navigation pattern. While optimal parameters for the biologically inspired offline model are calculated using an Expectation‐Maximization strategy, prediction is carried out by a particle filter. Parameters are estimated from several series of actual navigations performed by several pathologists in different virtual slides. The present approach is compared with other conventional prediction methods and decreases the calculated MSE in about a 50% for the entire group of pathologists. Microsc. Res. Tech., 2010. © 2009 Wiley‐Liss, Inc.
A novel method for shape from focus in microscopy using Bezier surface approximation
Authors: Muhammad Mannan Saeed , Choi Tae‐Sun 
Published: September 2009

AbstractIn this article, we introduce a novel shape from focus method to compute 3D shape of microscopic objects, based on modified‐pixel intensities and Bezier surface approximations. A new and simple but effective focus measure is proposed. In our focus measure, the original intensities of a sequence of small neighborhood are modified by subtracting the maximum of the values of first and last frames. An initial depth map is calculated by finding the maximum of the pixel's focused energy and its corresponding frame number. Missing information between two consecutive frames, false depth detection, and enhancement of noise related intensities may provide inaccurate depth map. To overcome these problems and to produce an accurate depth map, we proposed Bezier surface approximation. The proposed method is tested using synthetic and real image sequences. The comparative analysis demonstrates the effectiveness of the proposed method. Microsc. Res. Tech., 2010. © 2009 Wiley‐Liss, Inc.
Histometric and histomorphologic comparison of combustion and ambustion using in vivo reflectance‐confocal microscopy
Authors: Altintas Ahmet Ali , Amini Peymaneh , Altintas Mehmet Ali , Perbix Walter , Phan Vu , Stasch Tilman , Spilker Gerald 
Published: September 2009

AbstractBackground: When combustion and ambustion induce a superficial injury, they are summarized as superficial burns, regardless of the underlying cause. Reflectance‐confocal microscopy (RCM) allows noninvasive imaging of the human skin on morphological features. We hypothesized that combustion and ambustion have different histomorphological effects on the human skin. Methods: Superficial burns caused by combustion (CO‐group, five females, three males; aged 26.8 ± 14.2 years) and caused by ambustion (AM‐group, four females, four males; aged 28.1 ± 13.8 years) were evaluated 24 h after injury. The following parameters were obtained using RCM on injured and noninjured (control) site: horny layer thickness, epidermal thickness, granular cell size, basal layer thickness. Results: Compared with the controls (12.8 ± 2.5 μm), horny layer thickness decreased significantly to 10.6 ± 2.1 μm in the CO‐group, whereas it increased significantly to 17.8 ± 2.8 μm in the AM‐group. The epidermal thickness did not differ significantly in CO‐group (47.9 ± 2.1 μm) and AM‐group (49.0 ± 3.1 μm), however, both increased significantly compared with the controls (42.7 ± 1.6 μm). The basal layer thickness increased more in AM‐group (17.0 ± 1.2 μm) compared to CO‐group (15.4 ± 1.1 μm). Both differed significantly compared with their controls (13.9 ± 0.9 μm). The granular cell size increased significantly in both groups ompared to the controls (721 ± 42 μm), however, a significantly higher increase was observed in CO‐group compared to AM‐group (871 ± 55 μm vs. 831 ± 51 μm). Conclusions: RCM evaluates significant histomorphological differences in superficial burns caused by combustion and ambustion. The term “superficial burn” should consider the underlying cause and thus supplemented by the term “combustion” or “ambustion.” Microsc. Res. Tech., 2010. © 2009 Wiley‐Liss, Inc.
Cortactin/tyrosine‐phosphorylated cortactin interaction with connexin 43 in mouse seminiferous tubules
Authors: Vitale María Leiza , Akpovi Casimir D. , Pelletier R.‐Marc 
Published: September 2009

AbstractDeletion of the cortactin gene leads to male infertility. Considering that cortactin is an actin filament (F‐actin)‐binding protein associated with intercellular junctions, we measured changes in the expression and distribution of cortactin and tyrosine phosphorylated cortactin (P‐cortactin) in the seminiferous epithelium of developing and adult mice to address the physiological significance of cortactin to germ cell differentiation. Cortactin was expressed in neonatal and developing Sertoli cells. Cortactin levels decreased early during puberty, while P‐cortactin increased. Cortactin labeling was intense in the basal and apical thirds of the epithelium. Sertoli cell cytoplasmic processes facing spermatogonia, preleptotene spermatocytes, and step 8–13 spermatids were intensely labeled by both cortactin and P‐cortactin. In contrast, the middle region of Sertoli cells exhibited diffuse cortactin labeling but no P‐cortactin. This is consistent with the view that plasma membrane segments facing germ cells are part of the continuum of Sertoli cell junctional complexes that extend over lateral and apical membranes of supporting cells. Moreover, F‐actin and P‐cortactin share a common location in the seminiferous epithelium. The increased P‐cortactin levels detected during puberty may be related to the modulatory effect of cortactin tyrosine phosphorylation on actin assembly at sites of selected Sertoli cell‐germ cell contacts. Cortactin and connexin 43 (Cx43) were physically linked in seminiferous tubule homogenates and their colocalization in the basal and apical thirds of the seminiferous epithelium was stage‐dependent. Our results suggest that cortactin‐Cx43 interaction helps coordinate formation of cell‐to‐cell junctions and organization of the subsurface actin cytoskeleton in specific regions of the epithelium. Microsc. Res. Tech., 2009. © 2009 Wiley‐Liss, Inc.
Methodological assessment of acid‐etching for visualizing the osteocyte lacunar‐canalicular networks using scanning electron microscopy
Authors: Kubek Daniel J. , Gattone Vincent H. , Allen Matthew R. 
Published: September 2009

AbstractOsteocytes are the most abundant of the bone cells. Each osteocyte is contained within its own lacuna and connected to adjacent osteocytes via fillipodial processes, which form an intricate network of canaliculi within the matrix. Studying this intricate network of cells and their processes is difficult, because it exists embedded within a densely mineralized matrix. Scanning electron microscopy (SEM) has been shown to be a useful tool for visualizing this cellular network, yet the techniques involved for preparing specimens has not been systematically explored. The goal of this study was to investigate how variations in acid‐etching, both etching media and etching duration, affect SEM‐based visualization of the osteocyte lacunar–canalicular network. Bone samples were embedded in plastic and then acid etched in either 9% (10, 20, 40, and 60 s durations) or 37% (5, 10, and 15 s) phosphoric acid. Specimens were imaged using SEM, and qualitative evaluation of the lacunar–canalicular network was undertaken. Our findings show acid etchingwith a 9% phosphoric acid solution for 20 s provided the most favorable visualization of the osteocyte lacunar–canalicular network. Microsc. Res. Tech., 2010. © 2009 Wiley‐Liss, Inc.
Parallel deconvolution of large 3D images obtained by confocal laser scanning microscopy
Authors: Pawliczek Piotr , Romanowska‐Pawliczek Anna , Soltys Zbigniew 
Published: September 2009

AbstractVarious deconvolution algorithms are often used for restoration of digital images. Image deconvolution is especially needed for the correction of three‐dimensional images obtained by confocal laser scanning microscopy. Such images suffer from distortions, particularly in the Z dimension. As a result, reliable automatic segmentation of these images may be difficult or even impossible. Effective deconvolution algorithms are memory‐intensive and time‐consuming. In this work, we propose a parallel version of the well‐known Richardson–Lucy deconvolution algorithm developed for a system with distributed memory and implemented with the use of Message Passing Interface (MPI). It enables significantly more rapid deconvolution of two‐dimensional and three‐dimensional images by efficiently splitting the computation across multiple computers. The implementation of this algorithm can be used on professional clusters provided by computing centers as well as on simple networks of ordinary PC machines. Microsc. Res. Tech., 2010. © 2009 Wiley‐Liss, Inc.
Elaborate regulations of the predator‐induced polyphenism in the water flea Daphnia pulex: kairomone‐sensitive periods and life‐history tradeoffs
Authors: Imai Maki , Naraki Yuka , Tochinai Shin , Miura Toru 
Published: September 2009

AbstractAdaptive polyphenism produces alternative phenotypes depending on environmental stimuli. The water flea Daphnia pulex shows predator‐induced polyphenism, facultatively forming neckteeth in response to kairomones released by Chaoborus larvae. This study was designed to reveal the regulatory systems producing the defensive morph during embryonic and postembryonic development. As noted previously, the crest epithelium at the site of neckteeth is shown to thicken earlier the neckteeth formation, and the neckteeth number increased until the third instar, and later disappeared. Exposure to kairomone at various time points and intervals during development showed that the signal was required even at early postembryonic stages to maintain neckteeth. Moreover, two different induction methods, i.e. embryonic and maternal exposures, enabled us to discriminate maternal and zygotic effects in response to kairomone. Direct embryonic exposure is shown to be sufficient to form neckteeth without maternal effect although their growth was diminished; namely, there is a trade‐off for neckteeth production. However, maternal exposures resulted in larger progenies in smaller numbers, suggesting that the mother daphnids change their reproductive strategy depending on kairomone signals. Taken together, the developmental responses to the presence of predators are regulated elaborately at various levels. J. Exp. Zool. 311A:788–795, 2009. © 2009 Wiley‐Liss, Inc.
Efficient synthesis of 14‐substituted‐14‐H‐dibenzo[a,j]xanthenes using silica supported sodium hydrogen sulfate or amberlyst‐15 catalyst
Authors: Kumar Chebolu Naga Sesha Sai Pavan , Srinivas Chiguru , Sadhu Partha Sarathi , Rao Vaidya Jayathirtha , Palaniappan Srinivasan 
Published: September 2009

Abstract
magnified imageSilica supported sodium hydrogen sulfate (NaHSO4·SiO2) or amberlyst‐15 acts as an efficient heterogeneous catalyst for the preparation of 14‐alkyl and aryl‐14‐H‐dibenzo[a,j]xanthenes with various aldehydes and β‐naphthol in dichloroethane solvent in excellent yields. Synthesis of three new compounds are reported using this methodology. Recyclable nature of the amberlyst‐15 catalyst was also studied and the catalyst can be reused. J. Heterocyclic Chem., (2009).
Dimethylformamide dimethyl acetal as a building block in heterocyclic synthesis
Authors: Abu‐Shanab Fathi A. , Sherif Sherif M. , Mousa Sayed A. S. 
Published: September 2009

Abstract
magnified imageThis review focuses on the use of dimethylformamide dimethyl acetal in the preparation of heterocyclic compounds via formylation of active methylene groups, methyl groups to give enamines, and formylation of amino groups to give amidines. These compounds are found to be useful intermediates in the formation and modification of heterocyclic compounds. J. Heterocyclic Chem., (2009).
Modelling CoolMOSC3 transistor characteristics in SPICE
Authors: Górecki Krzysztof , Zarębski Janusz 
Published: September 2009

AbstractIn this paper three models of CoolMOSC3 transistors worked out by Infineon Technologies, dedicated for SPICE, are presented and investigated. These models are verified experimentally both for dc and ac device operating conditions. The advantages and drawbacks of the investigated models are shown and discussed. The device operating conditions, at which the models are of acceptable accuracy, are identified. Copyright © 2009 John Wiley & Sons, Ltd.
The compact d.c. electrothermal model of power MOSFETs for SPICE
Authors: Zarębski Janusz 
Published: September 2009

AbstractThis paper concerns the problem of modelling of power MOS transistors in SPICE. In the paper the new form of the electrothermal d.c. model (ETM) of the considered class of power devices is proposed. The ETM is based on the modified Shichman–Hodges model, in which the generation current, the breakdown voltage, the sub‐threshold region, the thermally dependent series resistances and self‐heating are included. The device inner temperature calculated from the thermal model is the sum of the ambient temperature and the product of the electrical power dissipated inside the device and its thermal resistance. The presented model has been verified experimentally. The results of calculations and measurements of MTD15N06V (ON Semiconductor) and IRF840 (International Rectifier) transistors are given as well. Copyright © 2009 John Wiley & Sons, Ltd.
A three‐dimensional mesh refinement algorithm with low boundary reflections for the finite‐difference time‐domain simulation of metallic structures
Authors: Pernice W. H. P. , Payne F. P. , Chaloulos K. , Gallagher D. F. G. 
Published: September 2009

AbstractWe present a method for including areas of high grid density into a general grid for the finite‐difference time‐domain method in three dimensions. Reflections occurring at the boundaries separating domains of different grid size are reduced significantly by introducing appropriate interpolation methods for missing boundary points. Several levels of refinement can be included into one calculation using a hierarchical refinement architecture. The algorithm is implemented with an auxiliary differential equation technique that allows for the simulation of metallic structures. We illustrate the performance of the algorithm through the simulation of metal nano‐particles included in a coarser grid and by investigating gold optical antennas. Copyright © 2009 John Wiley & Sons, Ltd.
Collective psychological ownership within the work and organizational context: Construct introduction and elaboration
Authors: Pierce Jon L. , Jussila Iiro 
Published: September 2009

AbstractThe construct collective psychological ownership is introduced. Reflecting the psychology of “us” and “ours,” collective psychological ownership emerges through interactive dynamics whereby individuals come to a single and shared mind‐set as it relates to a sense of ownership for a particular object. After providing a conceptual definition for the construct, we turn our attention to a detailed elaboration of the construct, offering comments on its genesis, emergent context, underlying motives, and a discussion of what can and cannot be owned. We also provide a discussion of the dynamics associated with its formation, highlighting the paths down which groups travel that influence the emergence of this psychological state. Next, we turn our attention to the emergence of collective psychological ownership within the organizational and teamwork context paying particular attention to the role of work environment structure. We conclude with a discussion of a set of work‐related attitudinal, motivational, behavioral, and stress‐related outcomes that stem from this psychological state. Copyright © 2009 John Wiley & Sons, Ltd.
Retracted: Authentically leading groups: The mediating role of collective psychological capital and trust
Authors: Walumbwa Fred O. , Luthans Fred , Avey James B. , Oke Adegoke 
Published: September 2009

AbstractAlthough there have been recent theoretical advances in what is increasingly being recognized as authentic leadership, research testing possible mediating processes and the impact on group‐level outcomes has not received attention. To help address this need, this study examined at the group level of analysis the role that collective psychological capital and trust may play in the relationship between authentic leadership and work groups' desired outcomes. Utilizing 146 intact groups from a large financial institution, the results indicated a significant relationship between both their collective psychological capital and trust with their group‐level performance and citizenship behavior. These two variables were also found to mediate the relationship between authentic leadership and the desired group outcomes, even when controlling for transformational leadership. Implications for future research and practice conclude the paper. Copyright © 2009 John Wiley & Sons, Ltd.