bluuebunny/crossref_metadata_2025_split huggingface dataset:
Lack of retrograde axonal transport of the heparin‐binding growth factors by chick ciliary neurones
Authors: Hendry I.A. , Belford D.A. 
Published: April 2003

AbstractIn view of the likelihood that the heparin‐binding growth factors of fibroblast growth factors are neurotrophic for the neurones of the chick ciliary ganglion a study has been made of the retrograde axonal transport of the acidic and basic fibroblast growth factors by these neurones. No high capacity retrograde axonal transport of these molecules was seen. The amount of transport was equivalent to the low level seen with many proteins such as horse radish peroxidase or bovine serum albumin rather than the convincing transport seen for nerve growth factor in the sympathetic system. The iodinated proteins retained their ability to bind to neuronal receptors. Thus, if the fibroblast growth factors are neurotrophic in the ciliary ganglion, they may exert their action by mechanisms other than the retrograde axonal transport of the factor itself.
Action of the diabetogenic drug streptozotocin on glycolytic and glycogenolytic metabolism in adult rat brain cortex and hippocampus
Authors: Plaschke Konstanze , Hoyer Siegfried 
Published: April 2003

AbstractIn sporadic Alzheimer's disease (AD), a number of metabolic alterations to the brain have been observed soon after the onset of the initial clinical symptoms. In particular, impairments of glucose utilization and related metabolic pathways are prominent and well‐established findings in incipient AD, resembling metabolic abnormalities such as have been found in noninsulin‐dependent diabetes mellitus. To mimic these abnormalities, we administered an intracerebroventricular (icv) injection of streptozotocin (STZ) to rats and studied the effects on glucose and glycogen metabolism in the cerebral cortex and hippocampus compared with controls. The enzymatic activities studied dropped significantly by 10–30% in brain cortex (cort.) and hippocampus (hc) 3 and 6 weeks after icv STZ injection: hexokinase (15% 3 weeks cort.; 14% 6 weeks cort.; 12% 3 weeks hc; 28% 6 weeks hc), phosphofructokinase (15%; 15%; 24%; 15%), glyceraldehyde‐3‐phosphate dehydrogenase (10%; 12%; 30%; 19%), pyruvate kinase (22%; 13%; 22%; 28%), glucose‐6‐phosphatase (10%; 23%; 14%; 19%) and phosphorylase a (22%; 11%; 30%; 15%).The content of glycogen was significantly higher in STZ‐treated rats than in control animals (7% 3 weeks and 15% 6 weeks in cortex).In contrast to the reduced enzymatic activities, we observed no changes in the concentrations of the glycolytic intermediates glucose, glucose‐6‐phosphate, fructose‐6‐phosphate, fructose‐1,6‐diphosphate, pyruvate, lactate and glucose‐1‐phosphate. These data clearly indicate reduced glycolytic enzyme activity after icv administration of STZ and suggest gluconeogenesis consequent on abnormalities in glucose breakdown. This model may thus be assumed to be a useful tool to investigate pathogenetic factors involved in sporadic dementia of Alzheimer type.
Ontogenesis of type II spiral ganglion neurons during development: Peripherin immunohistochemistry
Authors: Hafidi A. , Després G. , Romand R. 
Published: April 2003

AbstractIn this study, we analysed the distribution of the intermediate filament peripherin in the developing cochlea of the rat. At gestational day 16, weak immunolabeling was observed in neuronal somas throughout the spiral ganglion. At gestational day 20, the peripherin labeling increased in intensity throughout the cochlea but became especially strong in some ganglion neurons of the basal turn. Homogeneous immunolabeling was observed throughout the spiral ganglion of the apical turn. Double immunofluorescence labeling of the prenatal cochlea with peripherin and neurofilament (NF) antibodies revealed colocalization on the same structures. By postnatal day 3, the peripherin labeling intensity had decreased in the majority of spiral ganglion neurons, but remained strong in some cells of the basal turn. Only a few neurons continued to be immunolabeled into adulthood that correspond to Type II spiral ganglion neurons expressing both NF protein and peripherin, two classes of intermediate filament proteins. In the organ of Corti, the first immunolabeling was observed on gestational day 20 as peripheral fibers reaching the receptor cells. Positive fibers were observed below both inner (IHCs) and outer (OHCs) hair cells. At birth and at postnatal day 3, peripherin immunolabeling was still observed below both IHCs and OHCs. By postnatal day 4, peripherin labeling became more dominant in fibers below OHCs, but some immunoreactivity was still present below IHCs. No immunoreactivity was present in the intraganglionic spiral bundle (IGSB) fibers containing the olivary complex efferent fibers before birth. A few days after birth some fibers of the IGSB started to be immunoreactive.
Laminin concentrations in serum and cerebrospinal fluid in aging and alzheimer's disease
Authors: Kittur S.D. , Adler W.H. , Martin G.R. , Schapiro M.B. , Rapoport S.I. , Gunzler V. 
Published: April 2003

AbstractLaminin, a basement membrane protein, and a potent promoter of neurite outgrowth, surrounds all peripheral nerves. It appears in the central nervous system during development and reappears in response to injury. In Alzheimer's disease (AD), there is a progressive loss of neurons in specific areas of the brain along with the presence of an increased number of senile plaques and neurofibrillary tangles. Laminin levels have been shown to be increased in injury, so we undertook to examine levels of laminin by radioimmunoassay (RIA), in cerebrospinal fluid and serum of patients with AD and age‐matched controls. No difference in the CSF and serum laminin concentrations was found between Alzheimer's disease and age‐matched controls. We found a lack of correlation between severity of clinical dementia and laminin concentrations. Finally, we show that the CSF and serum laminin concentrations increase with age.
The migration and intermixing of donor and host glia on nitrocellulose polymers implanted into cortical lesion cavities in adult mice and rats
Authors: Harvey A.R. , Fan Y. , Connor A.M. , Grounds M.D. , Beilharz M.W. 
Published: April 2003

AbstractThe fate of neonatal glia (mostly glial fibrillary acidic protein‐positive astrocytes), cultured on nitrocellulose papers and implanted into cortical lesion cavities, was examined in adult mice and rats. In mice, a Y‐chromosome‐specific probe and in situ hybridization techniques were used to identify male cells. Male‐female grafts allowed visualization of donor glia and their behaviour after transplantation; female‐male grafts allowed an analysis of how host cells responded to the presence of the implants. There was substantial intermixing of cells, with many donor glia migrating away from the implants and host cells migrating onto both sides of the nitrocellulose paper. In rats, donor glia were labelled with fluorescein‐conjugated latex microspheres prior to transplantation on nitrocellulose polymers. The rat data were broadly consistent with those obtained from the mouse: moreover, immunohistochemical studies in rats suggested that the majority of host cells migrating onto the previously cell‐coated papers were astrocytes. In a number of studies, glia‐coated polymers have been used in an attempt to promote the regrowth of axons across lesion sites in the brain and spinal cord. The present work suggests that both transplanted and host glia may influence the regenerative growth seen in such implants.
Grafting of fast blue labeled glial cells into neonatal rat brain: Differential survival and migration among cell types
Authors: de los Monteros A. Espinosa , Bernard R. , Tiller B. , Rouget P. , de Vellis J. 
Published: April 2003

AbstractCultures of oligodendrocyte progenitor cells, ERD 1.1 cells, a nontransformed immortalized cell line of oligodendrocyte progenitors and C6 glioma cells were labeled with the fluorescent dye Fast Blue and transplanted into brains of 4 day postnatal Wistar rat pups. The localization of fluorescent cells within host brain was examined at various times post‐transplantation to determine patterns of cell migration as well as survival and integration among the host tissue. Oligodendrocyte progenitors migrated mainly along white matter tracks, integrating successfully into the host parenchyma. High survival rates were found between 5 and 27 days post grafting. ERD 1.1 cells survived and migrated between 1 and 5 days after transplantation. However, by 27 days survival had dropped from 60 to 20% of the initial cell population. The surviving cells were mainly localized to subventricular and subependymal regions at 27 days. C6 cells migrated extensively rostrally and caudally from the site of injection in the hippocampus and were tumorogenic. This finding confirmed previous reports on the survival and migration patterns of oligodendrocyte progenitors grafted into neonatal brain. However, they show that two cell lines that share phenotypic properties of oligodendrocyte progenitors markedly differ from these cells with respect to migration patterns and integration within host parenchyma. Fast Blue dye was still detectable after repeated cell division in grafted C6 cells, enabling us to track single cells as well as tumor formation. This dye should be useful not only to address issues of development, but also of tumor biology and therapeutic treatment.
Sequestering of immunoglobulins by astrocytes after cortical lesion and homografting of fetal cortex
Authors: Bernstein Jerald J. , Willingham L.A. , Goldberg William J. 
Published: April 2003

AbstractThe immunoglobulin (IgG, IgM, IgA) content of normal, reactive and migrated rat astrocytes was studied in lesioned adult rat cortex and after fetal cortex grafts. Implantation pockets were aspirated in the somatomotor cortex (under bregma) of adult Sprague‐Dawley rats. A fetal (E14) rat hemicortex incubated in the plant lectin Phaseolus vulgaris leucoagglutinin (graft premarker) was placed in the aspiration pocket or the pocket left empty (control). Sections of brain were immunohistochemically double labeled for immunoglobulins‐GFAP or Phaseolus vulgaris leucoagglutinin‐GFAP 3–60 days postoperative. Mature or fetal astrocytes in situ did not contain immunoglobulins. In pocket‐only animals, individual reactive astrocytes lining and subjacent to the pocket were positive for rat IgG, IgM and IgA (3–60 days). In grafted animals, graft derived astrocytes (Phaseolus vulgaris leucoagglutinin‐GFAP positive) were intermingled with host reactive astrocytes (Phaseolus vulgaris leucoagglutinin negative) lining and subjacent to the pocket. Both classes of astrocytes contained immunoglobulins IgG, IgM and IgA. Immunoglobulin positive graft derived astrocytes migrated into the corpus callosum, cingulum and habenula. These results demonstrate that astrocytes sequester immunoglobulins and probably other serum proteins as a critical function in restoring homeostasis to the injured or diseased nervous system.
Immunohistochemical staining for glial fibrillary acidic protein (GFAP) after deafferentation or ischemic infarction in rat visual system: Features of reactive and damaged astrocytes
Authors: Schmidt‐Kastner R. , Wietasch K. , Weigel H. , Eysel U.T. 
Published: April 2003

AbstractImmunohistochemical staining for glial fibrillary acidic protein (GFAP) is standard for visualization of reactive astrocytes in tissue sections, whereas various forms of astrocytic damage remain to be described in detail. In this study we tested differences in GFAP labeling in reactive astrocytes and in glial cells damaged by ischemia and edema. Studies were performed in the anatomically well defined visual system of rat. Basic staining patterns for GFAP were established in subcortical visual nuclei and visual cortex. In the first model, deafferentation of visual centers was performed by unilateral optic nerve lesion, and characteristic changes of GFAP labeling in reactive astrocytes were studied at 0.5,1,1.5,2,4,8 and 21 days after lesion. Initial changes were seen in the deafferented superior colliculus at 1 day after deafferentation with a diffuse increase and stellate types of reactive cells formed at 2–8 days. In the second model, small ischemie infarcts were produced in the visual cortex of rats using the method of photochemically‐induced thrombosis. GFAP labeling with a polyclonal antiserum was massively enhanced in the infarct at 4 hr. Characteristic morphological changes in damaged astrocytes were seen which were also identified in experiments with simulated global ischemia. In the surround of the infarct, swelling of astrocytes also caused increased labeling. At 3–4 days infarction typical reactive astrocytes surrounded the lesioned area. In conclusion, these immunohistochemical studies on GFAP in rat visual system allow for the following classifications, (a) Normal astrocytes vary in labeling at different anatomical localizations, (b) Reactive astrocytes show enhanced labeling and larger cell‐size within an interval of 1–2 days after lesion (c) Astrocytes damaged by ischemia reveal increased labeling of disintegrating cellular elements within hours after a lesion (d) Swollen astrocytes undergo enhanced labeling in areas with vasogenic edema.
Cell death after cartilage impact occurs around matrix cracks
Authors: Lewis Jack L. , Deloria Laurel B. , Oyen‐Tiesma Michelle , Thompson Roby C. , Ericson Marna , Oegema Theodore R. 
Published: April 2003

AbstractThe damage from rapid high energy impacts to cartilage may contribute to the development of osteoarthritis (OA). Understanding how and when cells are damaged during and after the impact may provide insight into how these lesions progress. Mature bovine articular cartilage on the intact patella was impacted with a flat impacter to 53 MPa in 250 ms. Cell viability was determined by culturing the cartilage with nitroblue tetrazolium for 18 h or for 4 days in medium containing 5% serum before labeling (5‐day sample) and compared to adjacent, non‐impacted tissue as viable cells per area. There was a decrease in viable cell density only in specimens with macroscopic cracks and the loss was localized primarily near matrix cracks, which were in the upper 25% of the tissue. This was confirmed using confocal microscopy with a fluorescent live/dead assay, using 5′‐chloromethylfluorescein diacetate and propidium iodide. Cell viability in the impacted regions distant from visible cracks was no different than the non‐impacted control. At 5 days, viable cell density decreased in the surface layer in both the control and impacted tissue, but there was no additional impact‐related change. In summary, cell death after the impaction of cartilage on bone occurred around impact induced cracks, but not in impacted areas without cracks. If true in vivo, early stabilization of the damaged area may prevent late sequelae that lead to OA. © 2003 Orthopaedic Research Society. Published by Elsevier Science Ltd. All rights reserved.
Discovery of a significant, nontopological preference for antiparallel alignment of helices with parallel regions in sheets
Authors: Hespenheide Brandon M. , Kuhn Leslie A. 
Published: April 2003

AbstractTo help elucidate the role of secondary structure packing preferences in protein folding, here we present an analysis of the packing geometry observed between α‐helices and between α‐helices and β‐sheets in 1316 diverse, nonredundant protein structures. Finite‐length vectors were fit to the α‐carbon atoms in each of the helices and strands, and the packing angle between the vectors, Ω, was determined at the closest point of approach within each helix–helix or helix–sheet pair. Helix–sheet interactions were found in 391 of the proteins, and the distributions of Ω values were calculated for all the helix–sheet and helix–helix interactions. The packing angle preferences for helix–helix interactions are similar to those previously observed. However, analysis of helix–strand packing preferences uncovered a remarkable tendency for helices to align antiparallel to parallel regions of β‐sheets, independent of the topological constraints or prevalence of β‐α‐β motifs in the proteins. This packing angle preference is significantly diminished in helix interactions involving mixed and antiparallel β‐sheets, suggesting a role for helix–sheet dipole alignment in guiding supersecondary structure formation in protein folding. This knowledge of preferred packing angles can be used to guide the engineering of stable protein modules.
Solution structure of the N‐terminal amphitropic domain of Escherichia coli glucose‐specific enzyme IIA in membrane‐mimetic micelles
Authors: Wang Guangshun , Keifer Paul A. , Peterkofsky Alan 
Published: April 2003

AbstractThe N‐terminal domain of enzyme IIAGlc of the Escherichia coli phosphoenolpyruvate:sugar phosphotransferase system confers amphitropism to the protein, allowing IIAGlc to shuttle between the cytoplasm and the membrane. To further understand this amphitropic protein, we have elucidated, by NMR spectroscopy, the solution structure of a synthetic peptide corresponding to the N‐terminal domain of IIAGlc. In water, this peptide is predominantly disordered, consistent with previous data obtained in the absence of membranes. In detergent micelles of dihexanoylphosphatidylglycerol (DHPG) or sodium dodecylsulfate (SDS), however, residues Phe 3–Val 10 of the peptide adopt a helical conformation in the ensemble of structures calculated on the basis of NOE‐derived distance restraints. The root mean square deviations for superimposing the backbone atoms of the helical region are 0.18 Å in DHPG and 0.22 Å in SDS. The structure, chemical shifts, and spin–spin coupling constants all indicate that, of the four lysines in the N‐terminal domain of IIAGlc, only Lys 5 and Lys 7 in the amphipathic helical region interact with DHPG. In addition, the peptide‐detergent interactions were investigated using intermolecular NOESY experiments. The aliphatic chains of anionic detergents DHPG, SDS, and 2,2‐dimethyl‐2‐silapentane‐5‐sulfonate sodium salt (DSS) all showed intermolecular NOE cross‐peaks to the peptide, providing direct evidence for the putative membrane anchor of IIAGlc in binding to the membrane‐mimicking micelles.
Synthesis of Helicene Scaffolds via [2+2+2] Cycloisomerization of Aromatic Triynes
Authors: Stará Irena G. , Starý Ivo , Kollárovič Adrian , Teplý Filip , Šaman David , Fiedler Pavel 
Published: April 2003

Triynes R-C≡C-CH2CH2-Ar-C≡C-Ar'-CH2CH2-C≡C-R were subjected to Co(I)- or Ni(0)-mediated intramolecular [2+2+2] cycloisomerization to provide corresponding tetrahydropentahelicene, tetrahydrohexahelicene, and tetrahydroheptahelicene in good to moderate yields. The reaction tolerates various substituents at pendant acetylene moieties (R = H, CH3, trimethylsilyl, not triisopropylsilyl) and fluorine in an aromatic part. By contrast, under Rh(I) or Pd(0) catalysis, triyne with the CH2OCH2 tether lost pendant propargyl moieties and an aromatic spiroketal was formed preferentially.
RECOGNITION OF HAND-PRINTED LATIN CHARACTERS BASED ON GENERALIZED HOUGH TRANSFORM AND DECISION TREE LEARNING TECHNIQUES
Authors: AMIN ADNAN 
Published: April 2003

This paper presents a new technique for the recognition of hand-printed Latin characters using machine learning. Conventional methods have relied on manually constructed dictionaries which are not only tedious to construct but also difficult to make tolerant to variation in writing styles. The advantages of machine learning are that it can generalize over a large degree of variation between writing styles, and recognition rules can be constructed by example. Characters are scanned into the computer and preprocessing techniques transform the bit-map representation of the characters into a set of primitives which can be represented in an attribute base form. A set of such representations for each character is then input to C4.5 which produces a decision tree for classifying each character.
UN THÉORÈME de BOCHNER–MINLOS AVEC UNE CONDITION D'INTÉGRABILITÉ
Authors: OUERDIANE HABIB , REZGUI ANIS 
Published: April 2003

Soit [Formula: see text] une fonction caractéristique définie sur un Fréchet nucléaire réel X. Si on suppose que [Formula: see text] est prolongeable par analycité au complexifié N de l'espace X et vérifie une condition de croissance de type exponentielle: [Formula: see text] où K ≥0, m >0, | |p étant une certaine norme de l'espace N et θ une fonction continue convexe satisfaisant certaines hyppothèses techniques. Soit μ la mesure associée à [Formula: see text] par le théorème de Bochner–Minlos, on montre qu'elle vérifie la condition d'intégrabilité suivante: [Formula: see text] où θ* est la fonction conjuguée de θ, m' >0 et | |-q est une certaine norme de l'espace dual X' de X. La réciproque de ce résultat est démontrée.
Comparison of the Bactericidal Activity of Moxifloxacin and Levofloxacin against <i>Staphylococcus aureus, Staphylococcus epidermidis, Escherichia coli</i> and <i>Klebsiella pneumoniae</i>
Authors: Lemmen S.W. , Häfner H. , Klik S. , Lütticken R. , Zolldann D. 
Published: April 2003

In addition to MIC and MBC tests in this study the serum bactericidal activity of 3.1 µg/ml of moxifloxacin or 5.2 µg/ml of levofloxacin was determined against ten susceptible strains of <i>S. aureus, S. epidermidis, E. coli </i>and <i>K. pneumoniae. </i>Moxifloxacin achieved markedly better activity against <i>S. aureus </i>and <i>S. epidermidis </i>as compared to levofloxacin. Activity of moxifloxacin against <i>E. coli </i>and <i>K. pneumoniae </i>was excellent but not superior to levofloxacin. In conclusion both fluorquinolones are highly effective against <i>E. coli </i>and <i>K. pneumoniae, </i>moxifloxacin being superior with respect to gram-positives like <i>S. aureus </i>and <i>S. epidermidis.</i>
Evaluation of Bioavailability of Heavy Metals in Soil by in vitro Screening Test
Authors: Yamada Aya , Ono Yoshiro , Kida Akiko , Namiki Kenji 
Published: April 2003

Abstract
The bioavailability of cadmium, lead, and chromium leaching from soil was determined by an in vitro experiment utilizing artificial stomach and small intestine solutions. The dissolved concentrations of these metals in the model stomach + small intestine condition was lower than those found in the model stomach as a result of the re-adsorption to the soil by titration from pH 2.0 to 7.0.