bluuebunny/crossref_metadata_2025_split huggingface dataset:
Changes in brain‐derived neurotrophic factor and trkB receptor in the adult Rana pipiens retina and optic tectum after optic nerve injury
Authors: Duprey‐Díaz Mildred V. , Soto Ileana , Blagburn Jonathan M. , Blanco Rosa E. 
Published: December 2002

AbstractIn this study we used immunocytochemistry to investigate the distribution of brain‐derived neurotrophic factor (BDNF) and its receptor tyrosine kinase (trkB) in retina and optic tectum of the frog Rana pipiens during regeneration after axotomy. We also measured changes in BDNF mRNA in retina and tectum. Retrograde labeling was used to identify retinal ganglion cells (RGCs) prior to quantification of the BDNF immunoreactivity. In control animals, BDNF was found in the majority of RGCs and displaced amacrine cells and in some cells in the inner nuclear layer (INL). After axotomy, BDNF immunoreactivity was reduced in RGCs but increased in the INL. BDNF mRNA levels in the retina remained high before and after axotomy. Three months after axotomy, after reconnection to the target, the staining intensity of many of the surviving RGCs had partially recovered. In the control tectum, BDNF staining was present in ependymoglial cells and in neurons throughout layers 4, 6, 8, and 9. After axotomy, BDNF staining in tectal neurons became more intense, even though mRNA synthesis was transiently down‐regulated. In control retinas, trkB receptor immunostaining was present in most RGCs; no significant changes were observed after axotomy. In control tectum, trkB was detected only in ependymoglial cells. After axotomy, many neuronal cell bodies were transiently labeled. Our data are consistent with the hypothesis that a considerable fraction of the BDNF normally present in RGCs is acquired from their targets in the tectum. However, there are also intraretinal sources of BDNF that could contribute to the survival of RGCs. J. Comp. Neurol. 454:456–469, 2002. © 2002 Wiley‐Liss, Inc.
Agonist‐stimulated cobalt uptake provides selective visualization of neurons expressing AMPA‐ or kainate‐type glutamate receptors in the retina
Authors: Pourcho Roberta G. , Qin Pu , Goebel Dennis J. , Fyk‐Kolodziej Bozena 
Published: December 2002

AbstractFast‐acting excitatory neurotransmission in the retina is mediated primarily by glutamate, acting at α‐amino‐3‐hydroxy‐5‐methyl‐4‐isoxazole propionic acid (AMPA) ‐selective and kainate‐selective receptors. To localize these sites of action, cat retinas were stimulated with either AMPA or kainate and processed for histochemical visualization of cobalt uptake through calcium‐permeable channels. Treatment with both agonists resulted in staining of A‐ and B‐type horizontal cells and several types of OFF cone bipolar cells; there was no evidence for staining of ON cone bipolar cells or rod bipolar cells. The subpopulations of OFF cone bipolar cells differed in their responses with two distinct types that stained heavily with cobalt after exposure to AMPA and three different types that were preferentially labeled after exposure to kainate. Although many amacrine and ganglion cells appeared to respond to both agonists, AII amacrine cells were stained after stimulation by AMPA but not by kainate. The OFF cone bipolar cells that exhibit AMPA‐stimulated cobalt uptake were found to have a high level of correspondence with cells that show immunocytochemical staining for the AMPA‐selective glutamate receptor subunits GluR1 and GluR2/3. Similarly, the cone bipolar cells exhibiting kainate‐stimulated cobalt uptake resemble those that are immunoreactive for the kainate subunit GluR5. The results indicate that, whereas many retinal neurons express both AMPA and kainate receptors, AII amacrine cells and subpopulations of OFF cone bipolar cells are limited to the expression of either AMPA or kainate receptors. This differential expression may contribute to the unique character of transmission by these cell types. J. Comp. Neurol. 454:341–349, 2002. © 2002 Wiley‐Liss, Inc.
Metabolic and neural activity in the song system nucleus robustus archistriatalis: Effect of age and gender
Authors: Adret Patrice , Margoliash Daniel 
Published: December 2002

AbstractThe sexually dimorphic robust archistriatal nucleus (RA) represents the telencephalic output of the bird song system. Here, we document sex‐dependent changes in both the metabolic and neuronal activity of RA during the sensory and sensorimotor phases of song learning. From posthatching day (PHD) 20–63 in males but not females, RA and its input nucleus HVc showed sharp increases in cytochrome oxidase (CO) activity relative to surrounding archistriatum and the underlying shelf, respectively. In urethane‐anesthetized birds, during the same period, the spontaneous activity of male RA neurons underwent dramatic changes in firing rate, distribution of interspike intervals, and bursting frequency, compared with other archistriatal cells. At PHD 20–21, RA neurons had extremely slow, irregular firing rates in birds of both sexes. In males, from PHD 30–36, RA neurons increased their firing rates and spiking activity became more regular, and at ∼PHD 38, strong bursts followed by inhibition (which in awake animals is associated with singing) began to be observed. Dual recordings from RA and HVc revealed synchronous bursting, with RA spikes lagging ∼10 msec behind HVc. We conclude that changes in relative CO activity correlate with changes in spontaneous firing rates within RA and that patterns of RA spontaneous activity exhibit gradual change as birds enter early song and then again for plastic song. The emergence of strong burst patterns in RA occurs later in life than does input from HVc as established by tracer studies or based on observed HVc bursting in young animals. J. Comp. Neurol. 454:409–423, 2002. © 2002 Wiley‐Liss, Inc.
Structure of the vertical and horizontal system neurons of the lobula plate in Drosophila
Authors: Scott Ethan K. , Raabe Thomas , Luo Liqun 
Published: December 2002

AbstractThe lobula plate in the optic lobe of the fly brain is a high‐order processing center for visual information. Within the lobula plate lie a small number of giant neurons that are responsible for the detection of wide field visual motion. Although the structure and motion sensitivity of these cells have been extensively described in large flies, the system has not been described systematically in Drosophila. Here, we use the mosaic analysis with a repressible cell marker (MARCM) system to analyze a subset of these cells, the horizontal and vertical systems. Our results suggest that the Drosophila horizontal system is similar to those described in larger flies, with three neurons fanning their dendrites over the lobula plate. We found that there are six neurons in the Drosophila vertical system, a figure that compares with 9–11 neurons in large flies. Even so, the Drosophila vertical system closely resembles the systems of larger flies, with each neuron in Drosophila having an approximate counterpart in large flies. This anatomical similarity implies that the inputs to the vertical system are similarly organized in these various fly species, and that it is likely that the Drosophila neurons respond to motions similar to those sensed by their specific structural counterparts in large flies. Additionally, the similar appearance of vertical system cells in multiple cell clones demonstrates that they share a common developmental lineage. Access to these cells in Drosophila should allow for the use of genetic tools in future studies of horizontal and vertical system function. J. Comp. Neurol. 454:470–481, 2002. © 2002 Wiley‐Liss, Inc.
Global well‐posedness and finite‐dimensional global attractor for a 3‐D planetary geostrophic viscous model
Authors: Cao Chongsheng , Titi Edriss S. 
Published: December 2002

AbstractIn this paper we consider a three‐dimensional planetary geostrophic viscous model of the gyre‐scale mid‐latitude ocean. We show the global existence and uniqueness of the weak and strong solutions to this model. Moreover, we establish the existence of a finite‐dimensional global attractor to this dissipative evolution system. © 2002 Wiley Periodicals, Inc.
Clinical utility of cognitive‐behavioural treatment for panic disorder. results obtained in different settings: a research centre and a public mental health care unit
Authors: García‐Palacios A. , Botella C. , Robert C. , Baños R. , Perpiñá C. , Quero S. , Ballester R. 
Published: December 2002

AbstractCognitive‐Behavioural programmes have become the treatment of choice for Panic Disorder (PD). However, although its effectiveness has been widely demonstrated, there are still some limitations regarding the possibility of offering this type of treatment to all panic sufferers. Some researchers are studying ways to make these programmes more available. This study deals with the application and testing of treatment programmes for PD in sites where patients usually look for help for their psychological problems, i.e. mental health care centres. Our work follows a strategy of benchmarking, and the results obtained after applying the treatment in habitual clinical contexts are compared with the results obtained after applying it in research contexts. In the present work, we analyse the possibility of ‘transporting’ a group cognitive‐behavioural programme for PD, developed in a research context, to a more natural setting, a public mental health unit. In this work we present data, using a benchmarking strategy, on one hand, on the differential effectiveness of a group cognitive‐behavioural treatment for PD applied in two different settings: a research setting—a clinical unit at the university; and a natural setting—a public mental health unit. On the other hand, we compare our results with those achieved by other studies carried out in research settings in different countries and a study carried out in a natural setting. Results indicated that our treatment was equally effective in both settings and that effectiveness was comparable to that achieved by the other studies in research and natural settings. Copyright © 2002 John Wiley & Sons, Ltd.
Prioritizing access to psychotherapy services: the client priority rating scale
Authors: Walton Carla J. , Grenyer Brin F. S. 
Published: December 2002

AbstractDetermining who gets priority to psychotherapy services within budget‐limited health services remains a dilemma. This study set out to investigate a new method of triage using the Client Priority Rating Scale (CPRS). Clinicians made weighted ratings in the domains of Suicidality, Severity of Presenting Problem, Strength of Internal Coping Resources, Availability of Interim Care Options and Possible Negative Impact of Waiting. The total score was then used to prioritize waiting times for psychotherapeutic services. In order to assess its utility, 68 clients who had been assigned CPRS scores were studied. The CPRS was found to have good inter‐rater reliability and internal consistency. As predicted, those with higher CPRS scores were significantly more likely to commence psychotherapy treatment before those with lower scores. CPRS score was also significantly related to diagnosis and social and psychological functioning. The CPRS method of triage is one approach that determines priority for clients seeking psychotherapy services. Copyright © 2002 John Wiley & Sons, Ltd.
A brief questionnaire of DSM‐IV‐defined anxiety and depression symptoms among children
Authors: Muris Peter , Meesters Cor , Schouten Erik 
Published: December 2002

AbstractThe present study examined the psychometric properties of the Revised Child Anxiety and Depression Scale (Chorpita, Yim, Moffitt, Umemoto, & Francis, 2000), a self‐report questionnaire for assessing symptoms of DSM‐defined anxiety disorders and major depression, in a large sample of school children (N = 1748). Exploratory and confirmatory factor analysis revealed that the structure of the RCADS was not fully in agreement with that reported by Chorpita et al. (2000). After removing conceptually inconsistent items, the questionnaire was reduced to 25 items representing five scales, namely, generalized anxiety disorder, separation anxiety disorder, social phobia, panic disorder, and major depressive disorder. A confirmatory factor analysis showed that a correlated 5‐factor structure of the shortened version of the RCADS (i.e. the RCADS‐25) indeed provided a good fit for the data. Second, the psychometric properties of the RCADS‐25 were comparable to those obtained with the full‐length version. That is, the questionnaire was reliable in terms of internal consistency and test–retest stability, displayed reasonable parent–child agreement, and good convergent and divergent validity. Altogether, the RCADS and its shortened version, the RCADS‐25, seem to be useful questionnaires for clinical and research purposes. Copyright © 2002 John Wiley & Sons, Ltd.
Single‐cell image analysis to assess ABC‐transporter–mediated efflux in highly purified hematopoietic progenitors
Authors: Raaijmakers H.G.P. , van den Bosch G. , Boezeman J. , de Witte T. , Raymakers R.A.P. 
Published: December 2002

AbstractBackgroundNormal and malignant hematopoietic stem cells are characterized by their capacity to actively extrude fluorescent dyes. The contribution of different ATP‐binding cassette (ABC) transporters to this phenomenon is largely unknown due to the small stem cell numbers limiting the use of standard methods to assess functional efflux.MethodsWe used epifluorescence microscopy (EFM) in combination with single‐cell image analysis to study ABC‐transporter–mediated efflux in highly purified, viable, CD34+CD38‐ cells sorted on an adhesive biolayer. P‐glycoprotein and multidrug‐resistant protein (MRP)‐mediated efflux were quantitated using fluorescent substrates (rhodamine‐123 and calcein acetoxymethyl ester [calcein‐AM]) and specific inhibitors (verapamil and probenecid, respectively).ResultsThe feasibility, sensitivity, and reproducibility of rhodamine‐123 efflux quantitation using single‐cell EFM was shown in cell lines and compared with standard flow cytometric assessment. P‐glycoprotein–mediated transport was higher in CD34+CD38‐ cells than in more differentiated progenitors (mean efflux index = 2.24 ± 0.35 and 1.14 ± 0.11, respectively; P = 0.01). P‐glycoprotein–mediated transport was the main determinant of the rhodamine “dull” phenotype of these cells. In addition, significant MRP‐mediated efflux was demonstrated in CD34+CD38‐ and CD38+ cells (mean efflux index = 1.42 ± 0.19 and 1.28 ± 0.18, respectively).ConclusionThe described method is a valuable tool for assessing ABC‐transporter–mediated efflux in highly purified single cells. Both P‐glycoprotein and MRP‐mediated efflux are present in human CD34+CD38‐ hematopoietic stem cells. Cytometry 49:135–142, 2002. © 2002 Wiley‐Liss, Inc.
Xenopus, the next generation: X. Tropicalis genetics and genomics
Authors: Hirsch Nicolas , Zimmerman Lyle B. , Grainger Robert M. 
Published: December 2002

AbstractA small, fast‐breeding, diploid relative of the frog Xenopus laevis, Xenopus tropicalis, has recently been adopted for research in developmental genetics and functional genomics. X. tropicalis shares advantages of X. laevis as a classic embryologic system, but its simpler genome and shorter generation time make it more convenient for multigenerational genetic, genomic, and transgenic approaches. Its embryos closely resemble those of X. laevis, except for their smaller size, and assays and molecular probes developed in X. laevis can be readily adapted for use in X. tropicalis. Genomic manipulation techniques such as gynogenesis facilitate genetic screens, because they permit the identification of recessive phenotypes after only one generation. Stable transgenic lines can be used both as in vivo reporters to streamline a variety of embryologic and molecular assays, or to experimentally manipulate gene expression through the use of binary constructs such as the GAL4/UAS system. Several mutations have been identified in wild‐caught animals and during the course of generating inbred lines. A variety of strategies are discussed for conducting and managing genetic screens, obtaining mutations in specific sequences, achieving homologous recombination, and in developing and taking advantage of the genomic resources for Xenopus tropicalis. © 2002 Wiley‐Liss, Inc.
Thyroid hormone promotes neurogenesis in the Xenopus spinal cord
Authors: Schlosser Gerhard , Koyano‐Nakagawa Naoko , Kintner Chris 
Published: December 2002

AbstractThree phases of neurogenesis can be recognized during Xenopus spinal cord development. An early peak during gastrulation/neurulation is followed by a phase of low level neurogenesis throughout the remaining embryonic stages and a later peak at early larval stages. We show here that several genes known to be essential for early neurogenesis (X‐NGNR‐1, XNeuroD, XMyT1, X‐Delta‐1) are also expressed during later phases of neurogenesis in the spinal cord, suggesting that they are involved in regulating spinal neurogenesis at later stages. However, additional neuronal determination genes may be important during larval stages, because X‐NGNR‐1 shows only scant expression in the spinal cord during larval stages. Thyroid hormone treatment of early larvae promotes neurogenesis in the spinal cord, where thyroid hormone receptor xTRα is expressed from early larval stages onward and results in precocious up‐regulation of XNeuroD, XMyT1, and N‐Tubulin expression. Similarly, thyroid hormone treatments of Xenopus embryos, which were coinjected with xTRα and the retinoid X receptor xRXRα, repeatedly resulted in increased numbers of neurons, whereas unliganded receptors repressed neurogenesis. Our findings show that thyroid hormones are sufficient to up‐regulate neurogenesis in the Xenopus spinal cord. © 2002 Wiley‐Liss, Inc.
Techniques and probes for the study ofXenopus tropicalisdevelopment
Authors: Khokha Mustafa K. , Chung Christina , Bustamante Erika L. , Gaw Lisa W.K. , Trott Kristin A. , Yeh Joanna , Lim Nancy , Lin Jennifer C.Y. , Taverner Nicola , Amaya Enrique , Papalopulu Nancy , Smith James C. , Zorn Aaron M. , Harland Richard M. , Grammer Timothy C. 
Published: December 2002

AbstractThe frogXenopus laevishas provided significant insights into developmental and cellular processes. However,X. laevishas an allotetraploid genome precluding its use in forward genetic analysis. Genetic analysis may be applicable toXenopus (Silurana) tropicalis, which has a diploid genome and a shorter generation time. Here, we show that many tools for the study ofX. laevisdevelopment can be applied toX. tropicalis. By using the developmental staging system of Nieuwkoop and Faber, we find thatX. tropicalisembryos develop at similar rates toX. laevis, although they tolerate a narrower range of temperatures. We also show that many of the analytical reagents available forX. laeviscan be effectively transferred toX. tropicalis. TheX. laevisprotocol for whole‐mount in situ hybridization to mRNA transcripts can be successfully applied toX. tropicaliswithout alteration. Additionally,X. laevisprobes often work inX. tropicalis—alleviating the immediate need to clone theX. tropicalisorthologs before initiating developmental studies. Antibodies that react againstX. laevisproteins can effectively detect theX. tropicalisprotein by using established immunohistochemistry procedures. Antisense morpholino oligonucleotides (MOs) offer a new alternative to study loss of gene activity during development. We show that MOs function inX. tropicalis. Finally,X. tropicalisoffers the possibility for forward genetics and genomic analysis. © 2002 Wiley‐Liss, Inc.
Survivin mRNA is down‐regulated during early Xenopus laevis embryogenesis
Authors: Murphy Cary R. , Sabel Jaime L. , Sandler Anthony D. , Dagle John M. 
Published: December 2002

AbstractOne of the hallmarks of early development is the rapid proliferation of cells immediately after fertilization. Many of the rules that govern cell division in normal somatic cells, such as contact inhibition and apoptosis, seem temporarily suspended in the early embryo. A similar suspension of mechanisms normally regulating cell division occurs in the development of cancer. Survivin, an inhibitor of apoptosis and a positive regulator of progression through the cell cycle, localizes to the mitotic spindle and interacts with several proapoptotic caspases. Survivin protein expression has been studied during the development of the salivary gland in mouse. However, the regulation of survivin during the critical transitions defining oocyte maturation and the early restriction of developmental potential are not easily examined in the mouse. We therefore studied survivin mRNA expression during oogenesis and early embryogenesis in Xenopus laevis. We found that survivin mRNA is present in the earliest stages of Xenopus oocytes and that it accumulates during oogenesis. Progesterone‐induced maturation of Xenopus oocytes leads to polyadenylation of the survivin transcript. Survivin mRNA is also present in early Xenopus embryos. After the onset of zygotic transcription, however, the amount of survivin mRNA declines rapidly to undetectable levels. This decrease in survivin mRNA correlates temporally with both the slowing of the cell cycle and the onset of endogenous embryonic apoptosis. With the exception of the ovary, survivin mRNA was undetectable in all adult Xenopus tissues examined. © 2002 Wiley‐Liss, Inc.
Metamorphosis‐dependent transcriptional regulation of xak‐c, a novel Xenopus type I keratin gene
Authors: Watanabe Yusuke , Tanaka Rumi , Kobayashi Hisao , Utoh Rie , Suzuki Ken‐Ichi , Obara Masanobu , Yoshizato Katsutoshi 
Published: December 2002

AbstractAnuran larvae transform their epidermis to the adult counterpart during metamorphosis. The major event of this process is the proliferation of larval epidermal basal cells and their differentiation into adult ones. The present study isolated novel type I keratin cDNA dubbed xak‐c (Xenopus adult keratin‐c) that was exclusively expressed in adult epidermal basal cells. The gene started its expression in the larval epidermis at the onset of metamorphosis. Thyroid hormone (TH) induced the precocious expression of the gene in the epidermis of premetamorphic tadpoles. To study the transcriptional regulation of this gene in relation to epidermal metamorphosis, a 2.8 kb 5′‐flanking region of xak‐c was cloned and its promoter activity was investigated. Gene constructs were made so as to contain the xak‐c promoter region and gene of EGFP or luciferase as a reporter gene and were transfected into various types of cells, which revealed that the 5′‐flanking region had an epidermal cell‐specific transcriptional activity in both anurans and mammals. Larval skin tissues of Xenopus were transfected with the constructs and cultured in the presence and absence of TH, which showed that the promoter region is responsive to TH, although the region did not contain the consensus TH response element‐like sequence. In sharp contrast, the promoter region did not respond to TH in the adult skin, clearly indicating that the cloned region contains specific sequences that respond to metamorphosis‐dependent transcription factor(s). © 2002 Wiley‐Liss, Inc.
Neural network pruning applied to real exchange rate analysis
Authors: Kaashoek Johan F. , van Dijk Herman K. 
Published: December 2002

AbstractNeural networks are fitted to real exchange rates of several industrialized countries. The size and topology of the networks is found through the use of multiple correlation coefficients, principal component analysis of residuals and graphical analysis of network output per hidden layer cell and input layer cell. These pruned neural networks are good approximations to varying non‐linear trends in real exchange rates. Non‐linear dynamic analysis shows that the long‐term equilibrium values of several European currencies correspond to the actual values within the European Monetary System. Based on its long‐term equilibrium value, the Euro appears to be undervalued vis‐à‐vis the US dollar at the introduction of the Euro on 1 January 1999. Copyright © 2002 John Wiley & Sons, Ltd.