bluuebunny/crossref_metadata_2025_split huggingface dataset:
Immunohistochemical localization of basic fibroblast growth factor in cultured rat astrocytes and oligodendrocytes
Authors: Vijayan V.K. , Lee Y.L. , Eng L.F. 
Published: April 2003

AbstractThe distribution of basic fibroblast growth factor in cultured astrocytes and oligodendrocytes was examined using immunocytochemistry. The results demonstrate a localization of basic fibroblast growth factor immunoreactivity predominantly in astrocyte nuclei at all stages of differentiation. Cytoplasmic and process staining was best detected during early stages of differentiation, under normal growth conditions or as a result of treatment with dibutyryl cyclic adenosine monophosphate. Astrocytes at all stages of differentiation bound antibody‐complexed bFGF, suggesting the presence of cell‐associated low affinity binding sites for the growth factor. Our studies also show the presence of immunoreactivity for basic fibroblast growth factor in process‐bearing oligodendrocytes. These results suggest a role for endogenous basic fibroblast growth factor in astrocyte and oligodendrocyte growth and function.
The neurotrophic peptide Org 2766 does not influence the expression of the immediate early gene c‐fos following sciatic nerve crush in the rat
Authors: Plantinga L.C. , Verhaagen J. , Wong S.L. , Edwards P.M. , Bär P.R. , Gispen W.H. 
Published: April 2003

AbstractThe neurotrophic peptide Org 2766 accelerates the regeneration of peripheral nerves. Although the mechanism of action of this neuropeptide is not yet understood, functional, pharmacological, and morphological evidence has demonstrated that Org 2766 exerts its beneficial effect during the early stages of nerve regeneration. The induction of some members of the Immediate Early Gene (IEG) family such as c‐jun and c‐fos is one of the first molecular events following peripheral nerve damage. The Fos and Jun proteins act as a transcription factor and may stimulate the expression of a number of genes implicated in nerve regeneration. We examined whether Org 2766 stimulates nerve regeneration by enhancing or prolonging the expression of c‐fos mRNA. Following a crush lesion of the sciatic nerve, the expression of c‐fos mRNA was induced in the spinal cord and in the damaged nerve at 30 min following injury in untreated animals as demonstrated with Northern blot. No effect of the crush lesion was observed in dorsal root ganglia (DRG). The induction of c‐fos mRNA in the damaged nerve was more robust as compared to the relatively small induction observed in the spinal cord. With in situ hybridization an increase in c‐fos mRNA expression both in the dorsal and in the ventral horn of the spinal cord was demonstrated at 30 min post‐lesion. In the distal sciatic nerve portion the expression of c‐fos mRNA was predominantly localized around Schwann cell nuclei at 30 min after nerve crush.The effect of Org 2766 treatment on the expression of c‐fos mRNA was investigated using semiquantitative dot blots. Dot blots containing RN A samples of DRG, spinal cord or sciatic nerve of control animals, saline treated and Org 2766 treated animals isolated 15 min, 30 min, l hr, 1 day and 2 days following nerve crush were scanned densitometrically. No significant effect of Org 2766 on the expression of c‐fos mRNA was detected. We conclude that Org 2766 does not stimulate peripheral nerve regeneration by affecting the expression of the c‐fos mRNA following sciatic nerve crush. The putative effect of Org 2766 on other immediate early transcription factors of the fos and jun family is currently under investigation.
Altered vasoactive intestinal polypeptide gene expression in the fetal rat suprachiasmatic nucleus following prenatal serotonin deficiency
Authors: Ugrumov M.V. , Trembleau A. , Calas A. 
Published: April 2003

AbstractThis study has evaluated the possible role of serotonin, a potential morphogen, in the regulation of vasoactive intestinal polypeptide (VIP) gene expression in the target neurons of the suprachiasmatic nucleus (SCN) before and after the onset of the serotonin neurotransmitter function. VIP gene expression was quantified by in situ hybridization of the corresponding mRNA on cryostat sections with subsequent film autoradiography and densitometry. The content of VIP mRNA was measured in the SCN in fetuses at the 21st embryonic day (E21) and in postnatal rats at day 11 (P11) following chronic depletion of serotonin by p‐chlorophenylalanine, an inhibitor of serotonin synthesis. This inhibitor was daily injected to pregnant rats for E13–20 or to postnatal animals for P2–10. Results of this study indicate that prenatal serotonin depletion caused a significant increase in VIP mRNA content in the SCN compared to control fetuses. On the contrary, the same treatment performed postnatally did not change VIP mRNA levels in the SCN. These data suggest that the VIP gene expression in differentiating target neurons of the SCN might be under serotonin inhibitory control during prenatal neurogenesis, prior to the onset of the serotoninergic neurotransmission.
The effects of reduced perfusion and reperfusion on C‐fos and HSP‐72 protein immunohistochemistry in gestational day 21 rat brains
Authors: Binienda Zbigniew , Scallet Andrew C. 
Published: April 2003

AbstractMetabolic stressors such as hyperthermia, seizures and ischemic hypoxia result in the induction of C‐fos and heat‐shock proteins (HSP) in affected brain cells of the adult rodent, especially within the hippocampal region, which normally has high metabolic demands. Here we ligated the uterine vessels of gestational day (GD) 21 rat pups to produce ischemic hypoxia. We confirmed that HSP‐72 protein, as previously reported, was activated in the perinatal rat pup, especially in the hippocampal CA3 region. However, the capability of hippocampal cells to produce C‐fos protein following drug‐induced seizures has been reported to develop only after postnatal day 13. Here, ischemic hypoxia caused CA1 hippocampal cells to produce immunohistochemically detectable C‐fos protein in GD‐21 rats. These results seem to contradict the previous reports of no C‐fos induction in rats this young by demonstrating a functional C‐fos translational mechanism by GD‐21. However, seizure vs ischemic hypoxia‐induced C‐fos expression may involve several different pre‐translational pathways. A delayed development of a receptor, second messenger, or genomic element for regulating C‐fos transcription remain as possible explanations for the late maturity of responsivity to seizures.
The effect of influenza C virus on the Purkinje cells of chick embryo cerebellum
Authors: Parker M. Sharon , O'Callaghan Richard J. , Smith Diane E. , Spence H. Adele 
Published: April 2003

AbstractIntra‐amniotic inoculation of influenza C virus resulted in observable and quantitatively measurable changes in the Purkinje cells of chick embryo cerebellum. Purkinje cells were visualized by the Golgi‐Cox procedure and prepared for statistical and computer evaluation from camera lucida drawings. Four computer‐generated measurements (the area of the dendritic arbor, the perimeter of the dendritic tree, and the height and width of the cell's arborization) and two manually counted measurements (total number of branches and the number of first order branches) were made. Analysis of Purkinje cells from influenza C virus‐infected embryos showed disturbances in dendritic arborization patterns and misalignment in the arrangement of the cells in the Purkinje cell layer compared to control cells. Statistical evaluation of Purkinje cell arborization showed significant decreases in all measured parameters for the influenza C virus‐infected members when compared with the members of the uninfected control group.
Immunocytochemical detection of serotonin content in raphe neurons of newborn and young adult rabbits before and after acute hypoxia
Authors: Kim Chung S. , McNamara M.Colleen , Lauder Jean M. , Lawson Edward E. 
Published: April 2003

AbstractThe present immunocytochemical study demonstrates serotonin (5‐HT) depletion in the dorsal raphe nucleus (DRN) of 3‐ and 21‐day‐old rabbits following exposure to mild (10% ambient partial pressure of oxygen) and severe hypoxia (5% ambient oxygen). Under the mild hypoxic condition, 5‐HT immunoreactivity in cells and fibers of the DRN was decreased in 3‐day‐old as well as 21‐day‐old rabbits, as indicated by decreased intensity of the staining compared to age‐matched controls. Although this decrease was more pronounced in the younger animals, recovery from mild hypoxia was seen in both age groups. Hypoxic effects were more striking in 3‐day‐old animals under the severe hypoxic condition, indicating a greater depletion of 5‐HT than in the mildly hypoxic condition. However, little additional effect on the older age group was seen. Further, a decreased ability of the 3‐day‐old rabbits to recover following severe hypoxia suggests that protracted effects on the developing serotonergic system occur following severe hypoxia during the neonatal period. This was demonstrated by the long‐lasting decrease in the number of stained cells and fibers of the DRN 4‐hr after return to normal conditions (21% O2). We conclude that newborns have a decreased rate of 5‐HT synthesis and/or metabolic turnover that results in rapid depletion of intracellular stores and protracted time to recover from a hypoxic challenge. Similar effects could occur in human fetuses, newborns or infants following birth trauma, apnea or other events associated with severe hypoxia.
Substance P (SP) and neurokinin a (NKA) in developing submandibular glands of the rat
Authors: Virta E. , Salo A. , Uusitalo H. 
Published: April 2003

AbstractThe effect of isoprenaline, carbachol, substance P (SP) and neurokinin A (NKA) on peroxidase and total protein secretion was studied in the developing postnatal submandibular glands of the rat using in vitro methods. Submandibular glands of 1, 5, 12 and 30 day‐old‐rats were stimulated by 10−5 M isoprenaline and carbachol, and 10−6 M SP and NKA. The stimulatory effects of these compounds were compared to the basic release of peroxidase and total amount of protein from submandibular gland fragments in incubation solution with no added transmitter substances. Indirect immunohistochemical methods were used to study these developing glands from SP‐ and NKA‐immunoreactive (IR) nerve fibers. The distributions of SP‐IR and NKA‐IR nerve fibers closely resembled each other, being most abundantly spread around the developing acini and ducts. The number of these fibers was high on the 1st, 5th and 12th days, but was decreased on the 30th day. On peroxidase release, isoprenaline was the most effective, causing a maximal response of 47 times the basic release on the first postnatal day, after which it gradually decreased. The effects of carbachol, SP and NKA on peroxidase release were clearly weaker and, unlike isoprenaline, their strongest response was on the 5th postnatal day (carbachol, 4.3; SP 5.2; NKA, 4.5). The total protein secretion effect patterns of the studied substances resembled each other more, showing their strongest response on the 5th day (isoprenaline, 5.0; carbachol, 4.5; SP, 4.2; NKA, 3.4) and decreasing thereafter.In general, both the stimulatory pattern of SP and NKA, and the appearance and distribution of SP‐IR and NKA‐IR nerve fibers during the early postnatal period of development closely resemble those of parasympathetic nerves and their transmitters. Furthermore, it is concluded that the abundancy of SP‐IR and NKA‐IR nerves in the developing submandibular gland is accompanied by the increased sensitivity of the secretory elements to these tachykinins, indicating that they play a role in the maturation of the glandular secretory functions.
Neural cell adhesion molecule and D3 protein in the cerebellum of weaver mutant mice
Authors: Jørgensen Ole Steen 
Published: April 2003

AbstractWeaver (wv/wv) mutant mice are characterized by extensive granule cell degeneration and can therefore be used as a model for brain degeneration that does not involve blood‐brain barrier damage. The ontogeny of the neural cell adhesion molecule (NCAM) and the neuronal antigen D3 protein were investigated in cerebellum and forebrain of weaver mutant mice up to post‐natal day 60. In the forebrain the concentration of both proteins was virtually unchanged. In cerebellum, in contrast, the concentration of D3 decreased markedly whereas that of NCAM remained unchanged. Similar findings were obtained at post‐natal day 30 in the cerebellum of other neurologic mutants, namely the staggerer (sg/sg) and reeler (rl/rl). At this age the concentration of a synaptic vesicle marker, synaptophysin. was severely decreased in the cerebellum of all three mutants. The concentration of neuron‐specific enolase was less affected, whereas the concentrations of the glial markers glutamine synthetase and glial fibrillary acidic protein were both increased. The NCAM/D3 concentration ratio, which probably reflects the ongoing rate of synaptic remodelling, was increased during the whole ontogeny of weaver mutant mice as compared with heterozygous controls. At post‐natal day 30, the ratio was increased by 180% in weaver, by 170% in staggerer and by 60% in reeler cerebellum. These findings lend further support to the usefulness of the NCAM/D3 ratio as a marker of neural plasticity and synaptic remodelling in both animals and man.
A neural‐network based method for prediction of γ‐turns in proteins from multiple sequence alignment
Authors: Kaur Harpreet , Raghava G.P.S. 
Published: April 2003

AbstractIn the present study, an attempt has been made to develop a method for predicting γ‐turns in proteins. First, we have implemented the commonly used statistical and machine‐learning techniques in the field of protein structure prediction, for the prediction of γ‐turns. All the methods have been trained and tested on a set of 320 nonhomologous protein chains by a fivefold cross‐validation technique. It has been observed that the performance of all methods is very poor, having a Matthew's Correlation Coefficient (MCC) ≤ 0.06. Second, predicted secondary structure obtained from PSIPRED is used in γ‐turn prediction. It has been found that machine‐learning methods outperform statistical methods and achieve an MCC of 0.11 when secondary structure information is used. The performance of γ‐turn prediction is further improved when multiple sequence alignment is used as the input instead of a single sequence. Based on this study, we have developed a method, GammaPred, for γ‐turn prediction (MCC = 0.17). The GammaPred is a neural‐network‐based method, which predicts γ‐turns in two steps. In the first step, a sequence‐to‐structure network is used to predict the γ‐turns from multiple alignment of protein sequence. In the second step, it uses a structure‐to‐structure network in which input consists of predicted γ‐turns obtained from the first step and predicted secondary structure obtained from PSIPRED. (A Web server based on GammaPred is available at http://www.imtech.res.in/raghava/gammapred/.)
The influence of a forest canopy on top‐down and bottom‐up diffusion in the planetary boundary layer
Authors: Patton E. G. , Sullivan P. P. , Davis K. J. 
Published: April 2003

AbstractResults from two nested‐grid large‐eddy simulations comparing cases with and without a plant canopy are presented. Through comparisons of numerically generated mean and turbulence statistics, the influence of a plant canopy with a leaf area index of two is shown to modify the air flow compared with an identical case without plants. Investigations of instantaneous fields and spatial spectra show that a plant canopy alters the spatial structure of turbulence and acts to shift the dominant scale to a scale on the order of the canopy height. Distributed drag and scalar sources, representing the presence of a scalar emitting deciduous forest, have little influence on top‐down diffusion, but enhanced mixing and increased turbulence intensities result in a dramatic modification to bottom‐up scalar diffusion up to ∼4.5 times the height of the canopy. Use of previously proposed bottom‐up gradient function with observations of scalar gradients under unstable stability conditions at 50 m over a 25 m tall forest (leaf area index of two) are shown to lead to an underestimate of the scalar emission flux by a factor of four. New top‐down and bottom‐up functions are proposed to include these canopy‐induced effects for this particular canopy. Copyright © 2003 Royal Meteorological Society
The characteristics of wind and wave fields modelled with different resolutions
Authors: Cavaleri Luigi , Bertotti Luciana 
Published: April 2003

AbstractA number of meteorological situations are studied using the operational models at the European Centre for Medium‐Range Weather Forecasts, and a series of short‐term forecast experiments is made for four different resolutions of the meteorological model. A comparison with the measurements and between the corresponding results allows an evaluation of the relative benefits of increased resolution. The focus is on the surface wind speeds and on the wave heights.Good quality results are found over the oceans, especially in areas with strong spatial gradients. Consistent with the already good quality of the present operational results, the improvements with increased resolution are small, but significant. In enclosed basins, as in the case of the Mediterranean Sea, it is found that both the surface wind speed and wave height are strongly underestimated. The improvements with increased resolution are greater than over the oceans, but still not sufficient to give agreement with measured data. Copyright © 2003 Royal Meteorological Society
Kinetic compensation effect in thermal decomposition of cellulosic materials in air atmosphere
Authors: Liu Naian , Zong Rowen , Shu Lifu , Zhou Jianjun , Fan Weicheng 
Published: April 2003

AbstractThe decomposition of wood and leaf of eight species in air atmosphere is examined by nonisothermal means with linear temperature programming, and a simple kinetic description is developed based on the experimental results and integral analysis method. The relation between the apparent activation energy E and preexponential factor A is analyzed, and it is found that the parameters E and A resulted from the variation of the species and the variation of model functions exhibit kinetic compensation effects. Quantitative and statistical criterion to distinguish between real and false compensation effects is discussed in detail. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 135–141, 2003
Hydrogenation of cis‐1,4‐poly(isoprene) catalyzed by OsHCl(CO)(O2)(PCy3)2
Authors: Charmondusit Kitikorn , Prasassarakich Pattarapan , McManus Neil T. , Rempel Garry L. 
Published: April 2003

AbstractThe quantitative hydrogenation of cis‐1,4‐poly(isoprene) (CPIP) provides an easy entry to the alternating copolymer of ethylene–propylene, which is difficult to prepare by conventional polymerization. The homogeneous hydrogenation of CPIP, in the presence of OsHCl(CO)(O2)(PCy3)2 as catalyst, has been studied by monitoring the amount of hydrogen consumed during the reaction. The final degree of olefin conversion measured by computer‐controlled gas uptake apparatus was confirmed by infrared spectroscopy and 1H nuclear magnetic resonance analysis. Kinetic experiments for CPIP hydrogenation in toluene solvent indicate that the hydrogenation rate is first order with respect to catalyst and carbon–carbon double bond concentration. A second‐order dependence on hydrogen concentration for low values and a zero‐order dependence for higher values of the hydrogen concentration was observed. The apparent activation energy for the hydrogenation of CPIP over the temperature range of 115–140°C was 109.3 kJ/mole. Mechanistic aspects of this catalytic process are discussed. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 142–152, 2003
Emerging use of gene expression microarrays in plant physiology
Authors: Wullschleger Stan D. , Difazio Stephen P. 
Published: April 2003

AbstractMicroarrays have become an important technology for the global analysis of gene expression in humans, animals, plants, and microbes. Implemented in the context of a well‐designed experiment, cDNA and oligonucleotide arrays can provide high‐throughput, simultaneous analysis of transcript abundance for hundreds, if not thousands, of genes. However, despite widespread acceptance, the use of microarrays as a tool to better understand processes of interest to the plant physiologist is still being explored. To help illustrate current uses of microarrays in the plant sciences, several case studies that we believe demonstrate the emerging application of gene expression arrays in plant physiology were selected from among the many posters and presentations at the 2003 Plant and Animal Genome XI Conference. Based on this survey, microarrays are being used to assess gene expression in plants exposed to the experimental manipulation of air temperature, soil water content and aluminium concentration in the root zone. Analysis often includes characterizing transcript profiles for multiple post‐treatment sampling periods and categorizing genes with common patterns of response using hierarchical clustering techniques. In addition, microarrays are also providing insights into developmental changes in gene expression associated with fibre and root elongation in cotton and maize, respectively. Technical and analytical limitations of microarrays are discussed and projects attempting to advance areas of microarray design and data analysis are highlighted. Finally, although much work remains, we conclude that microarrays are a valuable tool for the plant physiologist interested in the characterization and identification of individual genes and gene families with potential application in the fields of agriculture, horticulture and forestry. Copyright © 2003 John Wiley & Sons, Ltd.
Progress in establishing common standards for exchanging proteomics data
Authors: Orchard Sandra , Kersey Paul , Zhu Weimin , Montecchi‐Palazzi Luisa , Hermjakob Henning , Apweiler Rolf 
Published: April 2003

AbstractThe Proteomics Standards Initiative (PSI) aims to define community standards for data representation in proteomics and to facilitate data comparison, exchange and verification. Rapid progress has been made in the development of common standards for data exchange in the fields of both mass spectrometry and protein–protein interactions since the first PSI meeting . Both hardware and software manufacturers have agreed to work to ensure that a proteomics‐specific extension is created for the emerging ASTM mass spectrometry standard and the data model for a proteomics experiment has advanced significantly. The Protein–Protein Interactions (PPI) group expects to publish the Level 1 PSI data exchange format for protein–protein interactions by early summer this year, and discussion as to the additional content of Level 2 has been initiated. Copyright © 2003 John Wiley & Sons, Ltd.