bluuebunny/crossref_metadata_2025_split huggingface dataset:
Age‐dependent changes in the proliferative response of S‐100 protein‐positive glial cells to injury in the rat brain
Authors: Janeczko Krzysztof 
Published: April 2003

AbstractA mechanical injury was inflicted to the left cerebral hemisphere in rats of four age groups: newborns, 6, 14 and 30 days old. The injury was followed by [3H]thymidine injections at different time intervals. Brain sections were immunostained for S‐100 protein and subjected to autoradiography. During microscopic observations of the injury region, locations and numbers of the autoradiographically labeled astrocytes expressing S‐100 protein were recorded. On the basis of the observations, injury‐induced changes in the total number of proliferating astrocytes, as well as in their distribution, were analysed quantitatively.In rats injured neonatally, as well as those injured on postnatal days 6 and 14, the reactive increase in the number of proliferating astrocytes began on the first post‐traumatic day. In 30‐day‐old rats the increase was slower and appeared on day 2.The maximal increase in the astrocyte proliferative activity occurred in 6‐day‐old rats as early as day 1 after injury and was about eight times higher than that recorded in newborns, and nearly twice as high as that recorded in brains of 30‐day‐old rats.The results suggest that the intensity of astrocyte proliferative response to injury cannot be regarded as simply being proportional to the developmental progress of the brain tissue. Rather, these results indicate that changes in glial proliferative responses to injury follow a developmental time course, with a peak around the end of the first postnatal week.
Characterization of N‐cadherin messenger RNA and polypeptide expression in rat
Authors: Linnemann Dorte , Gaardsvoll Henrik , Dalseg Anne‐Marie , Zhernosekov Dmitri , Lundgren Torben , Edvardsen Klaus , Bock Elisabeth 
Published: April 2003

AbstractThe cell adhesion molecule N‐cadherin is a member of the cadherin gene superfamily. The protein is involved in morphogenetic processes, including neurite extension. In this study, N‐cadherin mRNA and polypeptide expression were investigated in rat brain, liver, muscle, heart, kidney and lung during postnatal development and aging. Six synthetic oligonucleotide probes covering different parts of mouse N‐cadherin cDNA all hybridized to 5.2,4.3–4.4 and 3.5 kb mRNAs in rat tissues. The mRNA pattern differed between tissues and, furthermore, the amount of N‐cadherin mRNA and polypeptides in brain, liver and heart was higher than in muscle, kidney and lung. N‐cadherin expression decreased slightly during early postnatal development in all tissues, whereas no changes in N‐cadherin expression were observed during aging.Antibodies against a fusion protein containing the transmembrane and cytoplasmic sequence of chick N‐cadherin were produced. These antibodies, termed anti‐N‐cad‐cyt, were compared to the R‐156 antibodies which recognize the 24 C‐terminal amino acids of N‐cadherin and which have been shown to react with a broad spectrum of cadherins. Using these two antibodies, it was shown that the 130 kDa N‐cadherin polypeptide was subject to calcium‐dependent cleavage of the cytoplasmic domain. Conversely, in the absence of calcium the polypeptide was cleaved extracellularly, producing two C‐terminal fragments of 85 and 95 kDa. A 122 kDa polypeptide was recognized by both antibodies and may be either an alternatively spliced form of N‐cadherin or a closely related cadherin.
Presynaptic ecto‐ and postsynaptic endo‐calcium‐adenosine‐triphosphatases in synaptosomes: Doubts about biochemical interpretation of localization
Authors: Kittel A. , Bácsy E. 
Published: April 2003

AbstractEcto‐ and endo‐Ca‐adenosine‐triphosphatase (ATPase) activity was identified as electrondense lead or cerium phosphate precipitate in the rat cortical synaptosomes by transmission electron microscopy and enzyme histochemistry. The formation of the deposit was dependent on the presence of ATP (the substrate), Ca (activator) and levamisole, quercetin or ouabain (inhibitors of different phosphatases and ATPases). Reaction products were found at the external surface of the presynaptic membrane, both surfaces of the postsynaptic membrane, in the synaptic cleft and in the free mitochondrial membranes. In the presence of ATP and the three inhibitors together, the quantity of the precipitate decreased markedly, but we still found some deposit on the external surface of the presynaptic membrane (this activity is probably due to the so‐called ecto‐ATPase) and on the internal surface of the postsynaptic one (endo‐ATPase). The distinction between ecto‐ and endo‐ATPases in biochemical fractions solely upon biochemical differential measurements must be interpreted with caution.
The potential role of nerve growth factor, brain‐derived neurotrophic factor and neurotrophin‐3 in avian cochlear and vestibular ganglia development
Authors: Bernd P. , Zhang D. , Yao L. , Rozenberg I. 
Published: April 2003

AbstractThe role of the nerve growth factor family of neurotrophins in the development of cochlear and vestibular ganglia is unclear. In order to predict the potential importance of nerve growth factor, brain‐derived neurotrophic factor or neurotrophin‐3, we examined the expression of neurotrophin mRNA and full‐length neurotrophin receptor mRNA by in‐situ hybridization and reverse transcription‐polymerase chain reaction, as well as whether high affinity 125I‐nerve growth factor binding was present, in cochlear and vestibular ganglia of the quail at several stages of development (stages 26, 31 and 36). Nerve growth factor, brain‐derived neurotrophic factor and neurotrophin‐3 mRNA was detected at all ages examined, suggesting that these neurotrophins may serve an autocrine or paracrine function, especially prior to target contact. In addition, we found full‐length trkA and trkC mRNA was expressed, the products of which are the functional neuronal receptors for nerve growth factor and neurotrophin‐3, respectively. Although full‐length trkA mRNA was found, physiologically important high affinity 125I‐nerve growth factor binding was not detected. Since nerve growth factor's effects on survival and neurite outgrowth are mediated through high affinity binding, nerve growth factor may serve an as yet unidentified role in this system. Full‐length trkB mRNA, the product of which is the functional neuronal receptor for brain‐derived neurotrophic factor, was not detected using reverse transcription‐polymerase chain reaction, however, truncated (non‐catalytic) trkB was present, at least in cochlear ganglia at stage 31. It is not known what function may be subserved by these truncated receptors.
Rapid response genes as markers of cellular signaling during cortical histogenesis: Their potential in understanding mental retardation
Authors: Kaufmann W.E. , Yamagata K. , Andreasson K.I. , Worley P.F. 
Published: April 2003

AbstractAberrations of dendritic morphology are seen in most forms of mental retardation (MR). Normal cortical development is dependent on neural activity that modulates developmental processes such as dendritic differentiation. Indeed, many of the classical histological correlates of MR are reproduced in models that alter activity during development. To explore the hypothesis that MR results from aberrant activity signals during development, it would be useful to have histochemical markers that are sensitive to neural activity. Recent studies indicate that certain immediate early genes (IEGs) are normally expressed at relatively high levels in cortical neurons during postnatal development and are rapidly regulated by natural activity. We have begun to assess the possible use of IEG markers to study MR by examining the pre‐ and postnatal developmental time course of a panel of known IEG transcription factors as well as a set of novel IEGs identified in our laboratory. One of these recently characterized clones encodes a novel, mitogen‐inducible cyclo‐oxygenase that is expressed during a critical period for dendritic formation and is regulated by N‐methyl‐d‐aspartate‐dependent synaptic activity and by environmental stimuli. These data suggest a role for prostaglandin signaling in postnatal cortical development. Other partially characterized novel IEGs are expressed in a cell‐specific fashion in the cortical plate. Application of these histochemical markers to the study of MR pathogenesis in animal models is discussed.
Neuropathology of twitcher mice: examination by histochemistry, immunohistochemistry, lectin histochemistry and fourier transform infrared microspectroscopy
Authors: Levine Steven M. , Wetzel David L. , Eilert Arnold J. 
Published: April 2003

AbstractThe twitcher mouse is an authentic animal model of globoid cell leukodystrophy, which is a genetic disease that affects the lysosomal enzyme galactocerebroside β‐galactosidase. This enzyme deficiency causes one of its substrates, galactosylsphingosine (psychosine), to accumulate in myelin‐forming cells, which eventually results in their death. In the central nervous system, the death of oligodendrocytes is thought to cause a series of secondary pathological changes. In this study, several techniques were utilized to examine the neuropathology of two different brain regions in the twitcher mouse—the hindbrain and the cerebrum. Neuropathological changes were as follows: (1) demyelination was detected in the hindbrain but not in the cerebrum, (2) a high density of periodic acid‐Schiff‐positive cells were detected in the hindbrain and to a lesser extent in the cerebrum, (3) astrocyte gliosis was pronounced in both the hindbrain and cerebrum, and (4) macrophages were abundant in both the hindbrain and the cerebrum. We found that Periodic acid‐Schiff‐positive cells, astrocyte gliosis and macrophage infiltration were present in white and gray matter regions of the cerebrum, while they were generally absent from the granule and molecular layers of the cerebellum. In addition to these studies, we utilized the technique of Fourier transform infrared (FT‐IR) microspectroscopy to identify the in situ distribution of psychosine in the brains of twitcher mice. Evidence was obtained that indicates a large accumulation of psychosine in the hindbrain, and to a lesser extent in the white matter of the cerebrum in the twitcher mouse, but not the normal mouse. There was no evidence for the accumulation of psychosine in the molecular layer of the cerebellum from the twitcher or normal mouse. Our conclusions are as follows: (1) pathology is more advanced in the hindbrain compared to the cerebrum, which is likely due to the hindbrain becoming myelinated prior to the cerebrum, (2) demyelination is not necessary for the development of secondary pathological changes, (3) pathology is not limited to white matter in the cerebrum, (4) pathology is not present in all brain regions, i.e. the granule and molecular layers of the cerebellum are devoid of pathological changes, and (5) psychosine accumulates in both the cerebrum and hindbrain, but not in the molecular layer of the cerebellum in the twitcher mouse. This study demonstrates that FT‐IR microspectroscopy can be used to correlate chemical changes to histopathological changes in brains from twitcher mice, which suggests that FT‐IR microspectroscopy may be a useful tool for studies examining other brain diseases.
An exploration of supplier selection practices across the supply chain
Authors: Choi Thomas Y. , Hartley Janet L. 
Published: April 2003

AbstractThe US auto industry has undergone tremendous changes during the past decade. Companies have increased their level of out‐sourcing and are relying more heavily on their supply chain as a source of their competitive advantage. Thus, determining which suppliers to include in the supplier chain has become a key strategic consideration. However, previous studies of supplier selection have not considered a company's position in the supply chain. In this paper, we compare supplier‐selection practices based on a survey of companies at different levels in the auto industry. Our findings rebut the common thinking that indirect suppliers who are more involved in commodity purchasing emphasize initial price and de‐emphasize relational considerations. We learned that selecting suppliers based on the potential for a cooperative, long‐term relationship is just as important to direct and indirect suppliers as it is to the auto assemblers. We also learned that price is one of the least important selection items, regardless of position on the supply chain. Further, contrary to the existing understanding that quality and delivery are separate constructs, they formed a single construct in our study. To summarize the empirical results, no differences among the auto assemblers, direct suppliers, and indirect suppliers were found for the importance placed on consistency (quality and delivery), reliability, relationship, flexibility, price, and service. Statistically significant differences were found between the auto assemblers and indirect suppliers on the importance placed on technological capability and financial issues.
The relative importance of journals used in operations management research A citation analysis
Authors: Vokurka Robert J. 
Published: April 2003

AbstractJournal rankings are important for a variety of reasons, most importantly as the basis of academic tenure and promotion decisions. A common approach in other fields is the citations methodology which is used in this study to determine the relative importance of various operations management (OM) journals. The citations analysis noted the frequency that all other journals are cited in Decision Sciences, Journal of Operations Management, and Management Science during the period 1992 to 1994. Rankings are provided based on total citations, citations per article, and citations per words published. The study shows that the journals with the most importance to OM research are Management Science, Decisions Sciences and Operations Research. Other journals important to OM research are the Harvard Business Review, Journal of Operations Management, and IIE Transactions.
A meta‐analysis model of manufacturing capabilities
Authors: White Gregory P. 
Published: April 2003

AbstractRecent research in operations strategy has focused on showing the extent to which manufacturing's competence in developing and executing one or more competitive capabilities affects the organization's overall business performance. Several of those efforts have produced models, such as the ‘sand cone’, that suggest an ideal sequence in which manufacturing capabilities should be developed. However, efforts to empirically validate such sequential models, except for one recent study, have been inconclusive. This paper takes a different approach to examining the relationships among competitive capabilities. The existing cross‐sectional studies of manufacturing capabilities are integrated to synthesize a proposed model of: (1) the relationships among manufacturing capabilities, and (2) the relationships between those capabilities and business performance. The proposed model is synthesized using data from previous studies, other models and theoretical arguments. Meta‐analysis is used to identify aspects of the model that appear better supported by empirical research and those that require further study. The implications of this proposed model with regard to research, practice and future research in operations strategy are discussed.
A tutorial on implementing concurrent engineering in new product development programs
Authors: Swink Morgan L. 
Published: April 2003

AbstractThe ‘concurrent engineering’ approach has radically changed the ways that new products are developed in many firms. However, implementing concurrent engineering has not always proved easy. As the popularity of concurrent engineering has grown and its applications have become more diverse, the core concepts that define concurrent engineering have become more and more vague. In addition, managers have found that different project, company, and industry contexts often necessitate customized approaches to concurrent engineering. This tutorial clarifies the concepts and methods that are central to the concurrent engineering approach. In addition, it examines the need to tailor the elements of concurrent engineering to match specific program priorities and product characteristics. Finally, the tutorial suggests ways that managers can make early concurrent engineering attempts more successful.
The relationship between self-esteem and psychiatric disorders in adolescents
Authors: Guillon M.S. , Crocq Marc-Antoine , Bailey P.E. 
Published: April 2003

AbstractObjectiveTo examine the relationship between self-esteem and psychiatric disorders in adolescents.MethodsSeventy-six adolescents (mean age: 16.02 years; range: 12-20) treated in an inpatient unit and presenting with DSM-IV psychotic disorder, depressive disorder, anxious disorder, anorexia nervosa, personality disorder, or conduct disorder were compared with a control group of 119 adolescents drawn from a normal population. All the subjects were assessed with the French translation of the Coopersmith self-esteem inventory (SEI).ResultsSelf-esteem was significantly higher in the control than in the clinical population (P= 0.0001). Female patients showed significantly lower SEI scores than male patients. Self-esteem increased significantly after 12 weeks in patients with a first psychotic episode who responded successfully to antipsychotic drug treatment. In the clinical group, a history of suicide attempts and sexual abuse was associated with significantly lower SEI scores. Lack of boy- or girlfriend, dropping out of school, and social withdrawal were also associated with lower self-esteem.ConclusionsThe presence of a psychiatric disorder in adolescents is associated with decreased self-esteem. This decrease in self-esteem varies according to the psychiatric disorder. Appropriate treatment can enhance self-esteem in adolescent patients.
Comparison of 13CαH and 15NH backbone dynamics in protein GB1
Authors: Idiyatullin Djaudat , Nesmelova Irina , Daragan Vladimir A. , Mayo Kevin H. 
Published: April 2003

AbstractThis study presents a site‐resolved experimental view of backbone CαH and NH internal motions in the 56‐residue immunoglobulin‐binding domain of streptococcal protein G, GB1. Using 13CαH and 15NH NMR relaxation data [T1, T2, and NOE] acquired at three resonance frequencies (1H frequencies of 500, 600, and 800 MHz), spectral density functions were calculated as F(ω) = 2ωJ(ω) to provide a model‐independent way to visualize and analyze internal motional correlation time distributions for backbone groups in GB1. Line broadening in F(ω) curves indicates the presence of nanosecond time scale internal motions (0.8 to 5 nsec) for all CαH and NH groups. Deconvolution of F(ω) curves effectively separates overall tumbling and internal motional correlation time distributions to yield more accurate order parameters than determined by using standard model free approaches. Compared to NH groups, CαH internal motions are more broadly distributed on the nanosecond time scale, and larger CαH order parameters are related to correlated bond rotations for CαH fluctuations. Motional parameters for NH groups are more structurally correlated, with NH order parameters, for example, being larger for residues in more structured regions of β‐sheet and helix and generally smaller for residues in the loop and turns. This is most likely related to the observation that NH order parameters are correlated to hydrogen bonding. This study contributes to the general understanding of protein dynamics and exemplifies an alternative and easier way to analyze NMR relaxation data.
Can correct protein models be identified?
Authors: Wallner Björn , Elofsson Arne 
Published: April 2003

AbstractThe ability to separate correct models of protein structures from less correct models is of the greatest importance for protein structure prediction methods. Several studies have examined the ability of different types of energy function to detect the native, or native‐like, protein structure from a large set of decoys. In contrast to earlier studies, we examine here the ability to detect models that only show limited structural similarity to the native structure. These correct models are defined by the existence of a fragment that shows significant similarity between this model and the native structure. It has been shown that the existence of such fragments is useful for comparing the performance between different fold recognition methods and that this performance correlates well with performance in fold recognition. We have developed ProQ, a neural‐network‐based method to predict the quality of a protein model that extracts structural features, such as frequency of atom–atom contacts, and predicts the quality of a model, as measured either by LGscore or MaxSub. We show that ProQ performs at least as well as other measures when identifying the native structure and is better at the detection of correct models. This performance is maintained over several different test sets. ProQ can also be combined with the Pcons fold recognition predictor (Pmodeller) to increase its performance, with the main advantage being the elimination of a few high‐scoring incorrect models. Pmodeller was successful in CASP5 and results from the latest LiveBench, LiveBench‐6, indicating that Pmodeller has a higher specificity than Pcons alone.
The crystal structure of augmenter of liver regeneration: A mammalian FAD‐dependent sulfhydryl oxidase
Authors: Wu Chia‐Kuei , Dailey Tamara A. , Dailey Harry A. , Wang Bi‐Cheng , Rose John P. 
Published: April 2003

AbstractThe crystal structure of recombinant rat augmenter of liver regeneration (ALRp) has been determined to 1.8 Å. The protein is a homodimer, stabilized by extensive noncovalent interactions and a network of hydrogen bonds, and possesses a noncovalently bound FAD in a motif previously found only in the related protein ERV2p. ALRp functions in vitro as a disulfide oxidase using dithiothreitol as reductant. Reduction of the flavin by DTT occurs under aerobic conditions resulting in a spectrum characteristic of a neutral semiquinone. This semiquinone is stable and is only fully reduced by addition of dithionite. Mutation of either of two cysteine residues that are located adjacent to the FAD results in inactivation of the oxidase activity. A comparison of ALRp with ERV2p is made that reveals a number of significant structural differences, which are related to the in vivo functions of these two proteins. Possible physiological roles of ALR are examined and a hypothesis that it may serve multiple roles is proposed.