bluuebunny/crossref_metadata_2025_split huggingface dataset:
Selective staining by vital dyes of Müller glial cells in retinal wholemounts
Authors: Uckermann Ortrud , Iandiev Ianors , Francke Mike , Franze Kristian , Grosche Jens , Wolf Sebastian , Kohen Leon , Wiedemann Peter , Reichenbach Andreas , Bringmann Andreas 
Published: December 2003

AbstractMüller glial cells within the retina may respond to different signaling molecules with an elevation of their intracellular free calcium. To prove the localization of the recorded calcium responses in Müller cells within acutely isolated retinal wholemounts, retinal pieces from adult animals and humans were exposed to different vital dyes just after the calcium imaging records were finished. The dyes, Mitotracker Orange, Mitotracker Green, Celltracker Orange, Celltracker Green, and monochlorobimane, are all selectively taken up by Müller glial cells, while neuronal cells remain largely devoid of the dyes. By using this method, it can be demonstrated that the free calcium alterations within the wholemounts indeed occur within Müller cells. Moreover, the cross‐sectional areas of (dye‐filled) Müller glial cell bodies, as well as of (dye‐free) neuronal cell bodies, can be measured in retinal wholemounts, and the spatial densities of both types of cells can be determined. The vital dye loading of Müller cells may facilitate investigations of stimulus‐induced alterations of retinal glial cell physiology and morphology. © 2003 Wiley‐Liss, Inc.
Activation of p38 mitogen‐activated protein kinase in spinal hyperactive microglia contributes to pain hypersensitivity following peripheral nerve injury
Authors: Tsuda Makoto , Mizokoshi Akito , Shigemoto‐Mogami Yukari , Koizumi Schuichi , Inoue Kazuhide 
Published: December 2003

AbstractNeuropathic pain is an expression of pathological operation of the nervous system, which commonly results from nerve injury and is characterized by pain hypersensitivity to innocuous stimuli, a phenomenon known as tactile allodynia. The mechanisms by which nerve injury creates tactile allodynia have remained largely unknown. We report that the development of tactile allodynia following nerve injury requires activation of p38 mitogen‐activated protein kinase (p38MAPK), a member of the MAPK family, in spinal microglia. We found that immunofluorescence and protein levels of the dually phosphorylated active form of p38MAPK (phospho‐p38MAPK) were increased in the dorsal horn ipsilateral to spinal nerve injury. Interestingly, the phospho‐p38MAPK immunofluorescence in the dorsal horn was found exclusively in microglia, but not in neurons or astrocytes. The level of phospho‐p38MAPK immunofluorescence in individual microglial cells was much higher in the hyperactive phenotype in the ipsilateral dorsal horn than the resting one in the contralateral side. Intrathecal administration of the p38MAPK inhibitor, 4‐(4‐fluorophenyl)‐2‐(4‐methylsulfonylphenyl)‐5‐(4‐pyridyl)‐1H‐imidazole (SB203580), suppresses development of the nerve injury‐induced tactile allodynia. Taken together, our results demonstrate that nerve injury‐induced pain hypersensitivity depends on activation of the p38MAPK signaling pathway in hyperactive microglia in the dorsal horn following peripheral nerve injury. © 2003 Wiley‐Liss, Inc.
Novel Route to L‐Hexoses from L‐Ascorbic Acid: Asymmetric Synthesis of L‐Galactopyranose and L‐Talopyranose Preliminary Communication
Authors: Ermolenko Ludmila , Sasaki N. André , Potier Pierre 
Published: December 2003

AbstractA novel route with L‐ascorbic acid as a single common starting material to asymmetric synthesis of all eight diastereomers of L‐hexoses is described. Assessment of this new approach is demonstrated by the expedient synthesis of L‐galactopyranose and L‐talopyranose derivatives. Key steps involve stereoselective preparation of chiral (E)‐ and (Z)‐γ‐hydroxy‐α,β‐unsaturated esters and their stereo‐controlled dihydroxylation by OsO4.
A Model Study towards a Conceptually New Synthetic Entry into the Seco‐ and Heteroyohimbine Alkaloid Families
Authors: Vogelsang Thomas , Borschberg Hans‐Jürg 
Published: December 2003

AbstractA model study is presented that paves the way to a new and flexible synthetic approach towards the seco‐ and heteroyohimbine alkaloid class. The key step involves a highly diastereoselective Cope rearrangement of an (E,E)‐azacyclodeca‐3,7‐diene grafted onto a 3‐ethylindole moiety to furnish a trans‐3,4‐divinylpiperidine derivative in 83% yield.
On the Distance‐Independent Hole Transfer over Long (A⋅T)n‐Sequences in DNA
Authors: Furrer Ernst , Giese Bernd 
Published: December 2003

AbstractElectron holes can travel through DNA double strands over long distances in a multistep ‘hopping’ process. But the influence of the DNA sequence on this process is still not understood in all details. We have carried out new experiments to understand the recent observation that the efficiency of the hole transport between guanines (G), which are separated from each other by long adenine⋅thymine (A⋅T) sequences, is nearly independent of the length of the (A⋅T)n sequence for n ≥ 4. For this purpose, a new synthesis of the modified adenosine 16 and its incorporation into a DNA double strand was worked out. Subsequent experiments demonstrated that the hole transport between GGG units and the H2O trapping of the guanine radical cation display similar rates. We conclude that the charge must be already partially equilibrated before being trapped by H2O. Thus, the weak distance effect is caused not only by the rate of the hole transport, but also by its equilibration over the (A ⋅ T)n sequence.
ω‐Fluoro Thiafatty Acids: New Mechanistic Probes of Desaturase‐Mediated Reactions
Authors: Hodgson Derek J. , Lao Kim Y. Y. , Dawson Brian , Buist Peter H. 
Published: December 2003

AbstractA series of 18‐fluoro thiastearates were prepared and incubated with a yeast Δ9‐desaturating system. The relative efficiency of desaturase‐mediated sulfoxidation was monitored via 19F‐NMR analysis of the sulfoxide products, and a strong preference for oxo transfer to the S‐atom occupying the 9‐position was confirmed. The oxidation profile obtained in this manner matched that of analogous experiments with non‐fluorinated substrates. These results form the basis of a versatile 19F‐NMR‐based method for mapping the position of the putative diiron oxidant relative to substrate, and has potential application to the study of membrane‐bound desaturases in vitro.
The Cofactor of Tetrachloroethene Reductive Dehalogenase of Dehalospirillum multivorans Is Norpseudo‐B12, a New Type of a Natural Corrinoid
Authors: Kräutler Bernhard , Fieber Wolfgang , Ostermann Sigrid , Fasching Mario , Ongania Karl‐Hans , Gruber Karl , Kratky Christoph , Mikl Christian , Siebert Anke , Diekert Gabriele 
Published: December 2003

AbstractThe corrinoid cofactor of the tetrachloroethene reductive dehalogenase of Dehalospirillum multivorans was isolated in its Coβ‐cyano form. This cofactor represents the main corrinoid found in D. multivorans cells. Analysis of the isolated cyano‐corrinoid by a combination of HPLC and UV/VIS‐absorbance spectroscopy revealed it to be nonidentical to a variety of known natural B12 derivatives. From high‐resolution mass‐spectrometric analysis, the molecular formula of the corrinoid isolated from D. multivorans could be deduced as C58H81CoN17O14P. The sample of the novel corrinoid from D. multivorans was further analyzed by UV/VIS, CD, and one‐ and two‐dimensional 1H‐, 13C‐, and 15N‐NMR spectroscopy, which indicated its structure to be closely related to that of pseudovitamin B12 (Coβ‐cyano‐7″‐adeninylcobamide). By the same means, the corrinoid could be shown to differ from pseudovitamin B12 only by the lack of the methyl group attached to carbon 176, and, therefore, it was named norpseudovitamin B12 (or, more precisely, 176‐norpseudovitamin B12). Norpseudovitamin B12 represents the first example of a ‘complete’ B12‐cofactor that lacks one of the methyl groups of the cobamide moiety, indicating that the B12‐biosynthetic pathway in D. multivorans differs from that of other organisms. X‐Ray crystal‐structures were determined for norpseudovitamin B12 from D. multivorans and the analogues pseudovitamin B12 and factor A (Coβ‐cyano‐7″‐[2‐methyl]adeninylcobamide). These first accurate crystal structures of complete corrinoids with an adeninyl pseudonucleotide confirmed the expected coordination properties around Co and corroborated the close conformational similarity of the nucleotide moieties of norpseudovitamin B12 and its two homologues.
On Facts and Artefacts: The Difficulty to Evaluate an Artificial Nuclease
Authors: Pitsch Stefan , Scheffer Ute , Hey Markus , Strick Andreas , Göbel Michael W. 
Published: December 2003

AbstractA number of promising synthetic catalysts for the hydrolytic degradation of RNA have been developed in recent years. Some of them show remarkable selectivity for pyrimidine nucleotides. The general problem of all these studies is to distinguish between real effects and artefacts caused by traces of contaminating natural ribonucleases. We show that methods representing the current state of the art (diethylpyrocarbonate treatment, sterilization, ultrafiltration, etc.) do not sufficiently protect against severe artefacts. However, an incorruptible assay could be found by comparing the cleavage of RNA and its mirror image. Enantiomeric RNA is completely resistant to enzymatic degradation, whereas achiral nonpeptide catalysts, by fundamental laws of symmetry, cannot distinguish between enantiomers and will induce exactly the same cleavage pattern with both substrates.
Crystalline Phase Separation of Racemic and Nonracemic Zwitterionic α‐Amino Acid Amphiphiles in a Phospholipid Environment at the Air/Water Interface: A Grazing‐Incidence X‐Ray Diffraction Study
Authors: Weissbuch Isabelle , Rubinstein Irina , Weygand Markus J. , Kjaer Kristian , Leiserowitz Leslie , Lahav Meir 
Published: December 2003

AbstractA grazing‐incidence X‐ray‐diffraction (GIXD) study of the self‐assembly, on water, of nonracemic γ‐stearyl glutamic acid (pure or as a mixture with racemic or (S)‐1,2‐dipalmitoyl‐glycero‐3‐phosphoethanolamine (DPPE)) demonstrated a phase separation of the α‐amino acid amphiphile into racemic and enantiomorphous two‐dimensional crystallites within the phospholipid domains. The packing arrangements of the two α‐amino acid crystalline phases were identical to those found in the absence of DPPE and have been determined, at almost atomic resolution, by X‐ray structure‐factor calculations. By contrast, racemic and nonracemic Nε‐stearoyllysine spontaneously segregated into two‐dimensional enantiomorphous domains within the DPPE environment that induced a change in the tilt direction of the hydrocarbon chains of the α‐amino acid molecules. Phase separation of nonracemic amphiphiles, originating from preferred lateral homochiral or heterochiral intermolecular interactions, is in agreement with the formation of enantiomerically pure or enriched homochiral oligopeptides in overrepresented amounts in the polycondensation of activated nonracemic amphiphilic α‐amino acids on plain water or within phospholipid monolayers.
Invited reaction: Informal learning and the transfer of learning: How managers develop proficiency
Authors: Marsick Victoria J. 
Published: December 2003

AbstractEnos, Kehrhahn, and Bell have made an important contribution to measuring informal learning and its transfer as
proficiency in a set of company‐identified managerial skills. Measurement of informal learning is at the
crux of research that seeks to link learning outcomes to other indicators of effective performance. The ability to
show how informal learning affects managerial proficiency also would help practitioners build a better business
case for planning and supporting informal learning. A drawback to the research methodology employed in this study
is reliance on self‐report, which the authors note but do not fully discuss. Questions also arise about the
nature of skills measured and the nature of managerial work in what appears to be a period of transition in the
company they examined. I conclude with some thoughts on alternative lenses for considering implications for
practice.
Learning orientation and goal orientation context: Relationships with cognitive and affective learning outcomes
Authors: Martocchio Joseph J. , Hertenstein Edward J. 
Published: December 2003

AbstractA field experiment of ninety‐six employees tested a model of the relationships among dispositional
learning orientation, self‐efficacy, goal orientation context, and declarative knowledge. Specifically, the
model predicted positive influences of task‐specific self‐efficacy (pre‐ and
mid‐training) and declarative knowledge in the relationship between learning orientation and
posttraining self‐efficacy. In addition, the model included a positive path from goal orientation context
(0 = performance; 1 = learning) to posttraining self‐efficacy. Finally, the
model included the interactive effect of learning orientation and goal orientation context on posttraining
self‐efficacy. The setting was an introductory Microsoft Access 97 software training course. But for three,
the hypotheses were supported, including the hypothesized interaction effect. Tests of three alternative models
showed poorer fits to the data than the hypothesized model.
Perceptions of constructive and destructive conflict within and across family subsystems
Authors: Rinaldi Christina M. , Howe Nina 
Published: December 2003

AbstractFamily members' (mothers, fathers, siblings) perceptions of the frequency and types of constructive and destructive conflict strategies used within and across the three family subsystems (marital, parent–child, sibling) were investigated. Participants included 60 fifth‐ and sixth‐grade, middle‐class white children, their closest‐in‐age sibling, and both parents. Each family member rated their perceptions of conflict resolution strategies employed in marital, parent–child, and sibling relationships. Overall, family members demonstrated agreement on the frequency and types of conflict within the three family subsystems and generally reported employing similar conflict tactics across different subsystems. Additionally, parent–child conflict strategies were partially linked to both constructive and destructive sibling and marital conflict. These results are best understood in light of both the shared family perspective view and the spillover hypothesis of family dynamics (Margolin et al., 1996; Minuchin, 1988). Implications for examining conflict strategies within and across subsystems are discussed within the context of recent theory on family functioning. Copyright © 2003 John Wiley & Sons, Ltd.
When home is in jail: child development in Spanish penitentiary units
Authors: Jiménez Jesús M. , Palacios Jesús 
Published: December 2003

AbstractThe quality of the educational family context of children who live with their mothers in prison (N=127, ageM=16.3 months) as well as how this situation affects their level of development are analysed. The assessment of these contexts was carried out using the HOME scale. The evaluation of the children's development was carried out using the Brunet–Lézine scale. The data shows that the quality of this context is extremely low, with one of the most striking features being the low score obtained in the subscales of provision of play materials and variety of experiences. Moreover, there are significant differences in the scores that are related to the mother's level of education, ethnic origins and the type of prison where they are serving their sentences. As for the scores obtained by the children in the Brunet–Lézine scale, the data shows that their level of development is similar to that of the infant population in general although we also found that the development quotients of the children in the group with the lowest scores in the HOME scale tend to drop significantly after 18 months of age. The results are discussed taking into account the interaction of context and development under the light of the canalization hypothesis, and making some suggestions about possible ways to improve these children's life conditions. Copyright © 2003 John Wiley & Sons, Ltd.
Links between socialization goals and child‐rearing practices in Chinese and Indian mothers
Authors: Rao Nirmala , McHale James P. , Pearson Emma 
Published: December 2003

AbstractMothers of preschoolers in China and India reported on the value they accorded to items tapping two socialization goals, Filial Piety and Socioemotional Development and two parenting styles, Authoritative and Authoritarian. In both cultures, maternal valuing of Filial Piety was associated with greater exertion of parental control, whereas greater valuing of Socioemotional Development was related to more frequent use of Authoritative practices. However, patterns in relationships between Filial Piety, Socioemotional Development and Authoritative parenting differed across Chinese and Indian mothers. Positive associations were found among these three variables for Indian mothers, reflecting Hindu beliefs about young children and childhood. Among Chinese mothers, on the other hand, Filial Piety was negatively related with Socioemotional Development and the use of Authoritative practices. Our results suggest that Chinese mothers believe that the use of authoritative practices, which encourage socioemotional development in children, will inhibit achievement of filial behaviour and academic achievement. Contrasts between these two Asian cultures highlight the importance of considering parents' socialization goals and beliefs in cross‐cultural studies of child‐rearing practices. Copyright © 2003 John Wiley & Sons, Ltd.
Photocrosslinkable polysaccharides based on chondroitin sulfate
Authors: Li Qiang , Williams Christopher G. , Sun Danny D. N. , Wang Jun , Leong Kam , Elisseeff Jennifer H. 
Published: December 2003

AbstractPhotopolymerizing hydrogels have demonstrated potential for use as a scaffold in numerous tissue‐engineering applications. The majority of photopolymerizing hydrogels are made from purely synthetic polymers. The purpose of this study was to synthesize and characterize photopolymerizing hydrogels derived from the biopolymer chondroitin sulfate in order to enhance the bioactivity of the scaffold and potentially improve tissue regeneration. Methacrylate groups were added to chondroitin sulfate, a major component of cartilage, using glycidyl methacrylate. The gels exhibited viscoelastic behavior typical of hydrogels. Cogels based on chondroitin sulfate and poly(ethylene glycol) demonstrated increasing pore size with increasing concentration of chondroitin sulfate as determined by water content, mechanical strength, and morphology using scanning electron microscopy. The chondroitin sulfate hydrogels degraded specifically in the presence of the enzyme chondroitinase. Chondrocytes remained viable after photoencapsulation and incubation in the biogels, suggesting their possible use for cartilage tissue engineering. © 2003 Wiley Periodicals, Inc. J Biomed Mater Res 68A: 28–33, 2004
Design and fabrication of standardized hydroxyapatite scaffolds with a defined macro‐architecture by rapid prototyping for bone‐tissue‐engineering research
Authors: Wilson C. E. , de Bruijn J. D. , van Blitterswijk C. A. , Verbout A. J. , Dhert W. J. A. 
Published: December 2003

AbstractThis investigation describes the production and characterization of calcium phosphate scaffolds with defined and reproducible porous macro‐architectures and their preliminary in vitro and in vivo bone‐tissue‐engineered response. Fugitive wax molds were designed and produced using a rapid prototyping technique. An aqueous hydroxyapatite slurry was cast in these molds. After sintering at 1250°C and then cleaning, dimensional and material characterizations of the scaffolds were performed. The resulting scaffolds represented the design, and their dimensions were remarkably consistent. A texture inherent to the layer‐by‐layer production of the mold was impressed onto the vertical surfaces of the scaffolds. The surface roughness (Ra) of the textured surfaces was significantly greater than that of the nontextured surfaces. Material analyses revealed a β‐TCP phase in addition to hydroxyapatite for the molded ceramics. Non‐molded control ceramics exhibited only hydroxyapatite. Thirty scaffolds were seeded with culture‐expanded goat bone‐marrow stromal cells (BMSCs) and implanted subcutaneously in nude mice for 4 or 6 weeks. Histology revealed mineralized bone formation in all the scaffolds for both implantation periods. After 4 weeks, bone was present primarily as a layer on scaffold surfaces. After 6 weeks, the surface bone formation was accompanied by bone budding from the surface and occasional bridging of pores. This budding and bridging bone formation almost always was associated with textured scaffold surfaces. However, the area percentage of bone in pores was similar for the 4‐ and 6‐week implantation periods. © 2003 Wiley Periodicals, Inc. J Biomed Mater Res 68A: 123–132, 2004
Recombinant growth/differentiation factor‐5 (GDF‐5) stimulates osteogenic differentiation of marrow mesenchymal stem cells in porous hydroxyapatite ceramic
Authors: Shimaoka Hideki , Dohi Yoshiko , Ohgushi Hajime , Ikeuchi Masako , Okamoto Masanori , Kudo Akira , Kirita Tadaaki , Yonemasu Kunio 
Published: December 2003

AbstractTo evaluate the growth/differentiation factor‐5 (GDF‐5) in the in vivo osteogenic potential of bone marrow mesenchymal stem cells (MSCs), we subcutaneously implanted five different kinds of hydroxyapatite (HA) ceramic implants: HA alone, GDF‐5/HA composites (GDF/HA), MSCs/HA composites, the MSCs/HA composites supplemented with GDF‐5 (GDF/MSCs/HA), and recombinant bone morphogenetic protein‐2 (BMP/MSCs/HA). Neither the HA alone nor the GDF/HA composites exhibited any bone formation at any time after implantation. At 4 weeks, the MSCs/HA composites exhibited a certain amount of bone formation in some pore areas. In contrast, at 2 weeks, the GDF/MSCs/HA composites exhibited histologically obvious de novo bone formation together with active osteoblasts in many pore areas and additional bone formation at 4 weeks. In the de novo formed bone, neither chondrocytes nor endochondral bone was detected. The GDF/MSCs/HA composites also showed high alkaline phosphatase (ALP) and osteocalcin expression determined at both the protein and gene levels and the high level of expression was well maintained even at 4 weeks. Compared with GDF/MSCs/HA, the BMP/MSCs/HA composites exhibited excellent osteogenesis with relatively early osteoblastic phenotype expression. The results indicate that GDF‐5 synergistically enhances de novo bone formation capability of MSCs/HA composite and suggest that tissue‐engineered GDF/MSCs/HA composites could be used as bone graft substitutes. © 2003 Wiley Periodicals, Inc. J Biomed Mater Res 68A: 168–176, 2004
Ultrastructural comparison of hydroxyapatite and silicon‐substituted hydroxyapatite for biomedical applications
Authors: Porter Alexandra E. , Best Serena M. , Bonfield William 
Published: December 2003

AbstractSilicon‐substituted hydroxyapatite (Si‐HA) has been shown to lead to significantly increased rates of bone apposition when compared with phase‐pure hydroxyapatite (HA) bioceramic implants (Patel N, et al. J Mater Sci Mater Med 2002;13:1199–1206). However, uncertainty remains about the mechanism by which Si increases the in vivo bioactivity. In this study, defect structures in Si‐HA were observed and characterized for the first time using high‐resolution transmission electron microscopy. Using tilting experiments and the g · b = 0 criterion for invisibility, the Burgers vectors of dislocations in phase‐pure HA and 0.8 wt % Si‐HA were characterized to be screw and mixed in character. Dislocations were observed in both pure HA and 0.8 wt % Si‐HA with no significant difference in dislocation density between HA and Si‐HA. However, our findings suggest that an increased number of triple junctions in Si‐HA may have a significant role in increasing the solubility of the material and the subsequent rate at which bone apposes Si‐HA ceramics. © 2003 Wiley Periodicals, Inc. J Biomed Mater Res 68A: 133–141, 2004