bluuebunny/crossref_metadata_2025_split huggingface dataset:
Dopaminergic amacrine cells in the inner nuclear layer and ganglion cell layer comprise a single functional retinal mosaic
Authors: Eglen Stephen J. , Raven Mary A. , Tamrazian Eric , Reese Benjamin E. 
Published: October 2003

AbstractMany types of retinal neuron are distributed in an orderly manner across the surface of the retina. Indeed, the existence of such regularity amongst a population of neurons, termed a retinal mosaic, may be a defining feature of functionally independent types of retinal neuron. We have examined the spatial distribution of dopaminergic amacrine cells in the ferret retina both in the inner nuclear layer (INL) and in the ganglion cell layer (GCL) to determine whether the cells in each layer form an independent retinal mosaic as evidence of whether they should be considered as two separate types. Ferret retinas contain approximately 1,900 dopaminergic amacrine cells, of which 27% are located in the GCL, and the rest in the INL. Based on analysis of their Voronoi domains as well as autocorrelation analysis and tests for complete spatial randomness, we found that the distribution of INL cells was statistically regular, while that of the GCL cells was not. However, by using cross‐correlation analysis, these two groups of cells were found to be spatially dependent: an exclusion zone was detected in the cross‐correlogram of roughly the same size as that found in the autocorrelograms of both INL and GCL cells. Such a pattern would be expected if dopaminergic amacrine cells in the INL and GCL were members of a single regular population differing only in their somatic depth. By using computer simulations, we tested this hypothesis directly, confirming that a random assignment of 27% from the total population produces cross‐correlograms that are indistinguishable from those of the biological mosaics. We conclude, therefore, that the cells in the two layers form a single functional population; those in the GCL appear to be misplaced. Somatic positioning with respect to depth within the retina is not, by itself, a reliable guide for functional classification. J. Comp. Neurol. 466:343–355, 2003. © 2003 Wiley‐Liss, Inc.
Regeneration of supraspinal axons after complete transection of the thoracic spinal cord in neonatal opossums (Monodelphis domestica)
Authors: Fry Elizabeth Jane , Stolp Helen Bronwyn , Lane Michael Aron , Dziegielewska Katarzyna Magdalena , Saunders Norman Ruthven 
Published: October 2003

AbstractThese studies define the time table and origin of supraspinal axons regenerating across a complete spinal transection in postnatal Monodelphis domestica. After lumbar (L1) spinal cord injection of fluorophore–dextran amine conjugate on postnatal (P) day 4, a consistent number of neurons could be labeled. The numbers of labeled neurons remained stable for several weeks, but subsequently declined by P60 in control animals and by P35 in animals with complete spinal transection (T4–T6) performed at P7. In control animals, 25–40% of neurons labeled with a fluorophore injected (L1) at P4 could also be double‐labeled by a second fluorophore injected (T8–T10) at different older ages. In spinally transected animals, total numbers of neurons labeled with the second marker were initially lower compared with age‐matched controls, but were not significantly different by 3 weeks after injury. The proportion of double‐labeled neurons in spinally transected animals increased from approximately 2% 1 week after injury (P14) to approximately 50% by P60, indicating that a substantial proportion of neurons with axons transected at P7 is able to regenerate and persist into adulthood. However, the proportion of axons originating from regenerating neurons made only a small contribution at older ages to total numbers of fibers growing through the injury site, because much of development of the spinal cord occurs after P7. Evidence was obtained that degenerating neurons with both apoptotic and necrotic morphologies were present in brainstem nuclei; the number of neurons with necrotic morphology was much greater in the brainstem of animals with spinal cords transected at P7. J. Comp. Neurol. 466:422–444, 2003. © 2003 Wiley‐Liss, Inc.
A parallel data assimilation model for oceanographic observations
Authors: van Hees Fons , van der Steen Aad J. , van Leeuwen Peter Jan 
Published: October 2003

AbstractIn this paper we describe the development of a program that aims at achieving the optimal integration of observed data in an oceanographic model describing the water transport phenomena in the Agulhas area at the tip of South Africa. Two parallel implementations, MPI and OpenMP, are described and experiments with respect to speed and scalability on a Compaq AlphaServer SC and an SGI Origin3000 are reported. Copyright © 2003 John Wiley & Sons, Ltd.
Coordinating components in middleware systems
Authors: Radestock Matthias , Eisenbach Susan 
Published: October 2003

AbstractConfiguration and coordination are central issues in the design and implementation of middleware systems and are one of the reasons why building such systems is more complex than constructing stand‐alone sequential programs. Through configuration, the structure of the system is established—which elements it contains, where they are located and how they are interconnected. Coordination is concerned with the interaction of the various components—when an interaction takes place, which parties are involved, what protocols are followed. Its purpose is to coordinate the behaviour of the various components to meet the overall system specification. The open and adaptive nature of middleware systems makes the task of configuration and coordination particularly challenging. We propose a model that can operate in such an environment and enables the dynamic integration and coordination of components by observing and coercing their behaviour through the interception of the messages exchanged between them. Copyright © 2003 John Wiley & Sons, Ltd.
Resource management in open Linda systems
Authors: Menezes Ronaldo 
Published: October 2003

AbstractCoordination systems, in particular Linda, have established themselves as important tools for the development of applications to open systems such as the Internet.This paper shows how to tackle a forgotten, but crucial problem in open coordination systems: memory management. As with any system which intends to be of wide use and because memory is a finite resource, coordination systems must address the problems of memory exhaustion. This paper first explores the orthogonality between coordination and computation in order to make it clear that the problem of memory exhaustion in coordination systems cannot be solved using garbage collection schemes implemented at the computation language—a garbage collection scheme must exist in the coordination environment as well.Following the explanation on orthogonality, the paper will focus on describing a garbage collection scheme for the Linda family of coordination systems. It is expected that the solution in Linda can be adapted to other coordination systems as long as they are based on tuple space communication. Copyright © 2003 John Wiley & Sons, Ltd.
BaMoO4 thin films prepared by electrochemical method at room temperature
Authors: Bi J. , Xiao D. Q. , Gao D. J. , Yu P. , Yu G. L. , Zhang W. , Zhu J. G. 
Published: October 2003

AbstractHighly crystallized BaMoO4 films were prepared on molybdenum substrates in Ba(OH)2 solutions by electrochemical method at room temperature. The deposition conditions (reaction temperature and current density) during electrochemical formation were researched. The films were characterized by using the X‐ray Diffraction (XRD), Scanning Electronic Microscopy (SEM) and X‐ray Photoelectron Spectroscopy (XPS) analyses. The XRD analyses show that the films are good crystalline with single scheelite‐type tetragonal structure; the SEM photographs show that the films are densely deposited with double tetragonal tapers in shape; and the XPS analyses reveal that the composition of the BaMoO4 films (embodied Ba2+, Mo6+ and O2‐) is in agreement with stoichiometry. The optimum electrochemical conditions for BaMoO4 films formation are the lower reacting temperature (near room temperature) and the feasible current density (about 1mA/cm2)
Effect of crystal disorder on linewidth of the Raman modes in GaS1‐xSex layered mixed crystals
Authors: Gasanly N. M. 
Published: October 2003

AbstractThe linewidths of Raman‐active intralayer compressional modes in GaS1‐xSex layered mixed crystals (0 ≤ x ≤ 1) have been measured in the 10‐300 K temperature range to study the anharmonic effect as a function of compositional variation and temperature. It was found that the anharmonicity increases with an increase in substitutional disorder. The cubic (three‐phonon) processes with energy conservation is responsible for the anharmonic contribution to the broadening of the intralayer phonon lines with temperature. (© 2003 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Studies on the growth and defects of La3Ga5SiO14 (LGS) crystals
Authors: Wang Z. M. , Yuan D. R. , Xu D. , Lv M. K. , Pan L. H. 
Published: October 2003

AbstractNew and high quality piezoelectric crystals La3Ga5SiO14 (LGS) grown by the Czochralski method in a Platinum or Iridium crucible are reported in this paper. The growth defects in the LGS crystals were investigated by Transmission electron microscopy (TEM). It was found that cracks, inclusions, grain boundary and thermal stress in the LGS crystals. Their formation mechanisms and the method of eliminating these defects are discussed. (© 2003 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Inhibition of NF‐kB/DNA Interactions and HIV‐1 LTR Directed Transcription by Hybrid Molecules Containing Pyrrolo [2,1‐c] [1,4] Benzodiazepine (PBD) and Oligopyrrole Carriers
Authors: Borgatti Monica , Rutigliano Cristina , Bianchi Nicoletta , Mischiati Carlo , Baraldi Pier Giovanni , Romagnoli Romeo , Gambari Roberto 
Published: October 2003

AbstractThe DNA binding properties and the effects on protein/DNA interactions of a series of four hybrids prepared combining oligopyrrole minor groove binders and pyrrolo [2,1‐c][1,4] benzodiazepine (PBD) were studied. In addition, the effects on in vitro and ex vivo transcription directed by the long terminal repeat (LTR) of the human immunodeficiency type 1 virus (HIV‐1) were analysed and structure‐activity relationships developed. These hybrids (compounds 2–5) contain from one to four pyrrole units, respectively. To investigate sequence‐selectivity and stability of drugs/DNA complexes, DNase I foothyphen‐printing, filter binding, and arrested polymerase‐chain reaction (PCR) were performed on HIV‐1 LTR gene sequences. The antiproliferative activity of the hybrids was tested in vitro on T‐lymphoid Jurkat cell lines and compared to antiproliferative effects of the natural product distamycin A 1 and pyrrolo [2,1‐c][1,4] benzodiazepine (PBD 6). The results obtained demonstrate that hybrids 2–5 exhibit different DNA‐binding activity with respect to both distamycin A 1 and PBD 6. A direct relationship was found between number of pyrrole rings present in the hybrids 2–5 and stability of drugs/DNA complexes. With respect to antiproliferative effects, it was found that the increase in the length of the polypyrrole backbone leads to an increase of in vitro antiproliferative effects, i.e., the hybrid 5, containing the four pyrroles distamycin analogs, is more active than 2, 3 and 4 against the Jurkat cell lines. With respect to inhibition of HIV‐1 LTR driven transcription, it was found that the hybrid 5 containing the four pyrroles distamycin analogs, is more active than 2, 3 and 4. Interestingly, the present results suggest that the hybrid 3 exhibits low antiproliferative activity on Jurkat cell lines, being still active in inhibiting HIV‐1 LTR driven transcription both in vitro and ex vivo. Drug Dev. Res. 60:173–185, 2003. © 2003 Wiley‐Liss, Inc.
Hypolipidemic Activity of New Phenoxyacetic Derivatives Related to α‐Asarone with Minimal Pharmacophore Features
Authors: Cruz María del Carmen , Salazar María , Garciafigueroa Yésica , Hernández Dolores , Díaz Francisco , Chamorro Germán , Tamariz Joaquín 
Published: October 2003

AbstractFive new series of potential hypolipidemic agents 3–7 were synthesized, in order to establish the minimal pharmacophore features associated to the potent hypocholesterolemic activity of natural α‐asarone (1) and synthetic clofibrate mimetic derivatives 2. The compounds were examined in hyperlipidemic male mice after oral administration of 25, 50, and 100 mg/Kg for 6 days. The isomeric series of acids and esters 3a–3c and 4a–4c were unexpectedly less active than the most simple structural isomeric compounds 5–7. This reveals that the phenoxyacetic acid scaffold carrying a hydrocarbon side chain, also found in derivatives 2, seems to be the most favorable lead for further development of potent hypolipidemic drugs. Drug Dev. Res. 60:186–195, 2003. © 2003 Wiley‐Liss, Inc.
Synthesis and anti‐Helicobacter pylori properties of NO‐donor/metronidazole hybrids and related compounds
Authors: Bertinaria Massimo , Galli Ubaldina , Sorba Giovanni , Fruttero Roberta , Gasco Alberto , Brenciaglia Maria Immacolata , Scaltrito Maria Maddalena , Dubini Francesco 
Published: October 2003

AbstractTwo series (A, B) of 2‐(2‐methyl‐5‐nitro‐1H‐imidazolyl)ethyl derivatives (6–9, 18–23) conjugated through an oxygen or an aminomethyl bridge with either a furoxan NO‐donor moiety or a furazan substructure, devoid of NO‐donor properties, were synthesised. A third group (C) of 2‐(2‐methyl‐5‐nitro‐1H‐imidazolyl)ethyl derivatives conjugated with nitrooxy and dinitrooxy NO‐donor functions (35, 38) as well as the corresponding analogue without these functions (40) were prepared. All the compounds were evaluated in vitro for their activity against a number of Helicobacter pylori strains. Metronidazole (1) and its amino analogue (11) were taken as reference compounds. All the synthesised hybrids and their analogues exhibited good anti‐H. pylori activity with MIC50 in the range less than 0.0039–1, resulting in compounds more active than metronidazole. Derivatives 6–9 displayed good potency also against metronidazole‐resistant strains. Compounds lacking the 5‐nitroimidazole moiety (24–29, 30–33) proved to be inactive against H. pylori with the exception of 33. The lack of significant differences in the antibacterial potency between furoxan and furazan hybrids in both series (A, B) suggest that the role of the N‐oxide moiety of the furoxan system either as an inductor of oxidative stress or as a promoter of NO‐donor properties is marginal. The substitution of the furoxan substructures with nitrooxy moieties (35, 38) afforded active compounds. In view of their NO‐donor properties, NO‐metronidazole hybrids could represent potential therapeutic tools both in the treatment of gastric ulcer and in a number of extragastrointestinal disorders such as ischaemic heart diseases and atherosclerosis‐related to some H. pylori strains. Drug Dev. Res. 60:225–239, 2003. © 2003 Wiley‐Liss, Inc.
Syntheses, calcium channel modulation effects, and nitric oxide release studies of O2‐alkyl‐1‐(pyrrolidin‐1‐yl) diazen‐1‐ium‐1,2‐diolate 4‐aryl(heteroaryl)‐1,4‐dihydro‐2,6‐dimethyl‐3‐nitropyridine‐5‐carboxylates
Authors: Velazquez Carlos , Vo Dean , Knaus Edward E. 
Published: October 2003

AbstractA group of racemic 4‐aryl(heteroary)‐1,4‐dihydro‐2,6‐dimethyl‐3‐nitropyridine‐5‐carboxy‐lates possessing a potential nitric oxide donor C‐5 O2‐alkyl‐1‐(pyrrolidin‐1‐yl)diazen‐1‐ium‐1,2‐diolate ester [alkyl=(CH2)n, n=1–4] substituent were synthesized using a modified Hantzsch reaction. Compounds having a C‐4 2‐trifluoromethylphenyl (16), 2‐pyridyl (17), or benzofurazan‐4‐yl (20) substituent generally exhibited more potent smooth‐muscle calcium channel antagonist activity (IC50 values in the 0.55 to 38.6 μM range) than related analogs having a C‐4 3‐pyridyl (18), or 4‐pyridyl (19) substituent with IC50 values > 29.91 μM, relative to the reference drug nifedipine (IC50=0.0143 μM). The point of attachment of C‐4 isomeric pyridyl substituents was a determinant of antagonist activity where the relative potency profile was 2‐pyridyl > 3‐pyridyl and 4‐pyridyl. Subgroups of compounds 16a–d, 17a–d, and 20a–d having alkyl spacer groups of variable chain length [–CO2(CH2)nO–, n=1–4] exhibited small differences in calcium channel antagonist potency. Replacement of the ester “methyl” moiety of Bay K 8644 by an O2‐alkyl‐1‐(pyrrolidin‐1‐yl)diazen‐1‐ium‐1,2‐diolate group provided the Bay K 8644 group of analogs 16a‐d that retained the desired cardiac positive inotropic effect. The most potent compound in this group, O2‐ethyl‐1‐(pyrrolidin‐1‐yl)diazen‐1‐ium‐1,2‐diolate 1,4‐dihydro‐2,6‐dimethyl‐3‐nitro‐4‐(2‐trifluoromethylphenyl)pyridine‐5‐carboxylate (16b, EC50=0.096 μM) is about eightfold more potent positive inotrope (cardiac calcium channel agonist) than the reference compound Bay K 8644 (EC50=0.77 μM). A similar replacement of the ester “isopropyl” group in the C‐4 benzofurazan‐4‐yl group of compounds by an O2‐alkyl‐1‐(pyrrolidin‐1‐yl)diazen‐1‐ium‐1,2‐diolate ester substituent provided compounds 20 (n=1 and 4) that were approximately equipotent cardiac positive inotropes with the parent reference compound PN 202‐791 (3, EC50=9.40 μM). The O2‐alkyl‐1‐(pyrrolidin‐1‐yl)diazen‐1‐ium‐1,2‐diolate ester moiety present in 1,4‐dihydropyridine calcium channel modulating compounds 16–20 is not a suitable •NO donor moiety because the percent nitric oxide released upon in vitro incubation with either l‐cysteine, rat serum, or pig liver esterase was less than 1%. Drug Dev. Res. 60:204–216, 2003. © 2003 Wiley‐Liss, Inc.
Growth inhibition of lung cancer cells by adenosine 5′‐triphosphate
Authors: Agteresch Hendrik J. , van Rooijen M. Helena C. , van den Berg J. Willem O. , Minderman‐Voortman Gardi J. , Wilson J. H. Paul , Dagnelie Pieter C. 
Published: October 2003

AbstractPreliminary clinical data suggest that adenosine 5′‐triphosphate (ATP) may inhibit lung tumor growth. Because studies of ATP on lung cancer cells are lacking, the aim of the present study was to explore effects of extracellular ATP on the growth and morphology of human lung tumor cells. Five human lung tumor cell lines derived from tumors with different cellular characteristics, i.e., a small cell carcinoma (GLC4), a large cell carcinoma (H460), a squamous cell carcinoma (H520), a mesothelioma (MERO82), and a papillary adenocarcinoma (H441), were exposed to 0, 0.5, 1, 2, and 3 mM ATP. Total cell numbers and dead or damaged cells were measured on days 1, 2, and 3. ATP induced a significant, dose‐dependent growth inhibition in GLC4, H460, H520, and MERO82 cells. In contrast, H441 cells showed already maximal inhibition at 0.5 mM. Compared to untreated control cell lines, a significant growth inhibition (mean ± SEM) of 65 ± 5% (GLC4), 59 ± 5% (H460), 45 ± 5% (H520), 38±2% (MERO82), and 55 ± 8% (H441) was shown after 3 days incubation with 3 mM ATP. ATP also induced changes in morphology and attachment to the substratum. Although not demonstrated by the Trypan Blue exclusion test, on photographs it seems that ATP induces death of GLC4 and H460 cells at higher concentrations. In conclusion, in four out of five explored lung tumor cell lines, ATP induces a dose‐dependent growth inhibition. Lung adenocarcinoma cells show already maximal inhibition at the lowest tested ATP dose. There is a relationship between growth inhibition and morphology changes. Drug Dev. Res. 60:196–203, 2003. © 2003 Wiley‐Liss, Inc.
Brain uptake of radiolabeled N‐oleoyl‐dopamine in the rat
Authors: Pokorski Mieczysław , Matysiak Zdzisław , Marczak Magdalena , Ostrowski Robert P. , Kapuściński Andrzej , Matuszewska Iwona , Kańska Marianna , Czarnocki Zbigniew 
Published: October 2003

AbstractN‐acyl‐dopamines are a novel class of biologically active lipids that have recently been identified in the brain and have the potential to interact with neural signaling pathways. This study seeks to determine the ability of N‐oleoyl‐dopamine, a synthetic amide of oleic acid and dopamine, to cross the blood brain barrier. We determined the tissue content of radioactivity in selected brain regions, in a short‐run study design, following injections of [3H]N‐oleoyl‐dopamine (0.4 µCi) into the internal carotid artery in the rat. These results were compared with intracarotid injections of [3H]dopamine and with intravenous injections of both radiolabeled compounds. The level of radioactivity was determined using liquid scintillation and was expressed as the percentage of its total dose injected per gram of tissue. We found that the 15‐min brain uptake of radioactivity, with no distinct regional variations, amounted to about 6% following the intracarotid [3H]N‐oleoyl‐dopamine, which was a significant 3–4‐fold increase over that following similar administration of [3H]dopamine. Intravenous injections of [3H]N‐oleoyl‐dopamine gave a much smaller yield of radioactivity in brain tissue samples which was still severalfold greater than that for intravenous [3H]dopamine. Qualitative thin‐layered chromatography screening showed the presence of unchanged N‐oleoyl‐dopamine in the brain following injections. We conclude that N‐oleoyl‐dopamine has an appreciable ability to cross the blood‐brain barrier, which contrasts the limited transfer of dopamine alone. N‐oleoyl‐dopamine might exert physiological effects due to its known affinity for the central vanilloid receptors or to better satisfying the brain tissue demand for dopamine. The study suggests a potential pharmacological role for N‐oleoyl‐dopamine delivered exogenously in helping regulate the brain function. Drug Dev. Res. 60:217–224, 2003. © 2003 Wiley‐Liss, Inc.
Investigating the safety of plants used in South African traditional medicine: Testing for genotoxicity in the micronucleus and alkaline comet assays
Authors: Taylor Joslyn L.S. , Elgorashi Esameldin E. , Maes Annemie , Van Gorp Urbain , De Kimpe Norbert , van Staden Johannes , Verschaeve Luc 
Published: October 2003

AbstractPrevious studies indicate that traditional botanical remedies can be valuable for treating human disease. The potential risk from long‐term use of such remedies has not, however, been fully investigated, especially in terms of their potential carcinogenic activity. In the present study, 51 South African plant species were selected on the basis of their use in traditional medicine and crude extracts were sequentially prepared from different dried plant parts using dichloromethane followed by 90% methanol. These extracts were tested for genotoxic activity in human peripheral blood lymphocytes using the micronucleus test, with further testing of select extracts using the alkaline comet assay. Screening results indicated the induction of significant numbers of micronuclei by many of the plant extracts. Several samples also induced DNA damage in human white blood cells using the alkaline comet assay. Although a number of these plants are recognised as toxic by traditional healers, several plants that are used in common remedies were found to be genotoxic and potentially dangerous. Environ. Mol. Mutagen. 42:144–154, 2003. © 2003 Wiley‐Liss, Inc.