bluuebunny/crossref_metadata_2025_split huggingface dataset:
Differential signalling of purinoceptors in HeLa cells through the extracellular signal‐regulated kinase and protein kinase C pathways
Authors: Muscella Antonella , Greco Simona , Elia Maria Giovanna , Storelli Carlo , Marsigliante Santo 
Published: April 2004

AbstractWe have previously shown that HeLa cells express P2Y2 and P2Y6 receptors endogenously and determined the pathways by which the P2Y2 controls proliferation and Na+/K+ATPase activity. Our objective in this study was to investigate the hypothesis that P2Y6 also controls proliferation and Na+/K+ATPase activity; the pathways used in these actions were partially characterised. We found that P2Y6 activation controlled cell proliferation but not the activity of the Na+/K+ATPase. UDP activation of P2Y6 provoked: (a) an increase in free cytosolic calcium; (b) the activation of protein kinase C‐α, ‐β, ‐δ, ‐ε, and ‐ζ but not of PKC‐ι and ‐η; (c) the phosphorylation of the extracellular signal‐regulated protein kinases 1 and 2 (ERK1/2); (d) the expression of c‐Fos protein. The P2Y6‐induced cell proliferation was blocked by the mitogen‐activated protein kinase kinase (MAPKK) inhibitor PD098059, thereby indicating that the ERK pathway mediates the mitogenic signalling of P2Y6. PKC and phosphoinositide 3‐kinase (PI3K) inhibitors were tested at two different time points of ERK1/2 phosphorylation (10 and 60 min). The results suggest that novel PKCs and PI3K initiate the response but both conventional and atypical PKCs are required for the maintenance of the UDP‐induced phosphorylation of ERK1/2. The induction of c‐Fos was greatly diminished by conventional or atypical PKC‐ζ inhibition, suggesting that it may be due to PKC‐α/β and ‐ζ activity. These observations demonstrate that UDP acts as a proliferative agent in HeLa cells activating multiple signalling pathways involving conventional, novel, and atypical PKCs, PI3K, and ERK. Of these pathways, conventional and atypical PKCs appear responsible for the induction of c‐Fos, while ERK is responsible for cell proliferation and depends upon both novel and atypical PKCs and PI3K activities. © 2004 Wiley‐Liss, Inc.
Apotransferrin is internalized and distributed in the same way as holotransferrin in K562 cells
Authors: Xiu‐lian Du , Kui Wang , Ya Ke , Lan Yuan , Rong‐chang Li , Yan Zhong Chang , Kwok Ping Ho , Zhong Ming Qian 
Published: April 2004

AbstractTransferrin (Tf), a naturally existing protein, has received considerable attention in the area of drug targeting since it is biodegradable, non‐toxic, and non‐immunogenic. The efficient cellular uptake of Tf shows it has potential in the delivery of anti‐cancer drugs, proteins, and therapeutic genes into proliferating malignant cells that overexpress transferrin receptor (TfR). In human serum, about 30% of Tf exists in the iron‐saturated form (Fe2‐Tf) and the remainder exists as apotransferrin (apo‐Tf). Understanding the uptake of apo‐Tf by cells will provide key insights into studies on Tf‐mediated drug delivery. In the present study, we investigated visually the transport of apo‐Tf into K562 cells and its intracellular localization by laser‐scanning confocal microscopy (LSCM) and flow cytometry analysis (FCA). It was found that, like Fe2‐Tf, apo‐Tf can be taken up into the cells. The process is time‐ and temperature‐dependent, competitively inhibited by Fe2‐Tf, and significantly abolished by pronase pretreatment. Visual evidence showed that the transport of apo‐Tf into K562 cells is a TfR‐mediated process. Furthermore, the investigations using optical‐slicing technique demonstrated that the distribution of apo‐Tf is similar to that of Fe2‐Tf, both appearing in the perinuclear region in ball‐in‐bowl shape. J. Cell. Physiol. 201: 45–54, 2004. © 2004 Wiley‐Liss, Inc.
Some probabilistic restatements of the Four Color Conjecture
Authors: Matiyasevich Yuri 
Published: April 2004

AbstractWith every triangulation of sphere, we associate a probabilistic space in a natural way and define several random events. The Four Color Conjecture (4CC) turns out to be equivalent to different statements about positive correlation among some pairs of these events. © 2004 Wiley Periodicals, Inc. J Graph Theory 46: 167–179, 2004
A note on a conjecture about cycles with many incident chords
Authors: Jiang Tao 
Published: April 2004

AbstractGiven positive integers n and k, let gk(n) denote the maximum number of edges of a graph on n vertices that does not contain a cycle with k chords incident to a vertex on the cycle. Bollobás conjectured as an exercise in [2, p. 398, Problem 13] that there exists a function n(k) such that gk(n) = (k + 1)n − (k + 1)2 for all n ≥ n(k). Using an old result of Bondy [3], we prove the conjecture, showing that n(k) ≤ 3 k + 3. © 2004 Wiley Periodicals, Inc. J Graph Theory 46: 180–182, 2004
Swim bladder and posterior lateral line nerve of the nurseryfish, Kurtus gulliveri (Perciformes: Kurtidae)
Authors: Carpenter Kent E. , Berra Tim M. , Humphries Julian M. 
Published: March 2004

AbstractThe morphology of the swim bladder and inner ear of the nurseryfish, Kurtus gulliveri, appear adapted for enhanced pressure wave reception. The saccule is enlarged and surrounded by very thin bone and two large fontanelles that would present reduced resistance to pressure waves. The swim bladder is elaborate, with six dorsolaterally projecting pairs of lobes that are tightly encased in ribs and an additional caudally projecting pair of lobes encased in the first hemal spine. The ribs and musculature surrounding the swim bladder laterally are very thin, so that four or five “rib windows” are readily apparent on back‐lit specimens. This swim bladder–rib configuration would also present reduced resistance to pressure waves to enhance function as a peripheral auditory structure. However, high‐resolution X‐ray computed tomography and dissection reveal no anterior projections of the swim bladder that could serve as a mechanical coupling to the inner ear. The posterior lateral line nerve is well developed and lies directly over the tips of the ribs encasing the swim bladder lobes. This nerve is not, however, associated with a lateral line canal and a lateral line canal is absent on most of the body. We hypothesize that the posterior lateral line nerve transmits mechanosensory information from the swim bladder. J. Morphol. 260:193–200, 2004. © 2004 Wiley‐Liss, Inc.
Location of the ureteral openings in the cloacas of tinamous, some ratite birds, and crocodilians: A primitive character
Authors: Oliveira Cleida Aparecida , Silva Renata Mageste , Santos Marcileida Maria , Mahecha Germán Arturo Bohórquez 
Published: March 2004

AbstractCloacas of 67 avian species, of both sexes, from various habitats and differing dietary habits, were examined macro‐ and microscopically to investigate possible variation in the location of the ureteral openings. Differing from most birds studied, in adult male Rhea americana and several tinamous species the ureters were found to open into the coprodeum. In these species the urodeum receives only the vas deferens or oviduct. Similarly, in crocodiles Caiman crocodilus yacare, but not in lizards Tropidurus montanus and snakes Crotalus durissus terrificus, the ureters empty into the coprodeum. This similarity between ancient birds (ratites and tinamous) and crocodiles may indicate a primitive character linking reptiles and birds. This unusual position of the ureteral orifice can represent an adaptation to facilitate urine collection into the coprodeum and large intestine. Another possibility is that this variation in ureter position is a male reproductive strategy to avoid the mixture of urine and semen in the cloaca. There were no evident correlations between the location of the ureteral openings and the birds' habitat, diet, or histology of the coprodeal mucosa. The occurrence of a phallus in eight species of birds was detected, as well as a peculiar vascularization related to the coprodeal epithelium of anseriformes. Together, these data add to the scarce information about the morphophysiology of the avian cloaca, and also contribute to clarify avian phylogenetic linkages. J. Morphol. 260:234–246, 2004. © 2004 Wiley‐Liss, Inc.
Towards Green Routes for Polymer Synthesis: Polymerization of Cyclodextrin Host‐Guest Complexed Diethyl Fumarate and Copolymerization with Complexed Styrene in Homogenous Aqueous Solution
Authors: Choi Soo‐Whan , Ritter Helmut 
Published: April 2004

AbstractSummary: The radical homo‐ and copolymerization of styrene (1) and diethyl fumarate (DEF, 2) in the presence of methylated β‐cyclodextrin (β‐CD) in water is described. It has been shown for the first time that homopolymerization of CD‐complexed DEF and its copolymerization with CD‐complexed styrene occur readily in aqueous solution. In the absence of CD, or in organic solvents, the homopolymerization of DEF is strongly retarded.image
The Association of Tetraalkylammonium Ions with Poly(vinyl methyl ether) in Water and its Effect on Phase‐Separation Behavior as Studied by Micro‐Raman Spectroscopy
Authors: Maeda Yasushi , Yamamoto Hiroki , Ikeda Isao 
Published: April 2004

AbstractSummary: The thermosensitive phase‐separation of poly(vinyl methyl ether) in water has been investigated by micro‐Raman spectroscopy in the presence of tetraalkylammonium bromides. The equilibrium distribution of both polymer and salts to the polymer‐rich and solvent‐rich phases was determined as a function of temperature. Tetraalkylammonium ions with longer alkyl chains associate more strongly with PVME and raise the phase‐transition temperature due to an increase in hydrophilicity.image
An Ordered Nanoporous Monolith from an Elastomeric Crosslinked Block Copolymer Precursor
Authors: Cavicchi Kevin A. , Zalusky Andrew S. , Hillmyer Marc A. , Lodge Timothy P. 
Published: April 2004

AbstractSummary: An ordered nanoporous monolith was prepared from a poly(isoprene‐b‐dimethylsiloxane) (PI‐PDMS) hexagonally packed cylinder precursor. The PDMS cylinders were macroscopically aligned, the PI was crosslinked with dicumyl peroxide, and the PDMS was removed using tetrabutylammonium fluoride. The stability of the pores depended on the modulus of the matrix. At high crosslink density the pores were stable, but they collapsed at a low crosslink density. The nanoporous materials could be swollen in toluene.A scanning electron micrograph of the end‐on view of crosslinked degraded poly(isoprene‐b‐dimethylsiloxane).imageA scanning electron micrograph of the end‐on view of crosslinked degraded poly(isoprene‐b‐dimethylsiloxane).
Cover Picture: Macromol. Rapid Commun. 6/2004
Authors: Hittinger Eric , Kokil Akshay , Weder Christoph 
Published: April 2004

Cover: The cover picture shows the schematic and detailed chemical structure of a cross‐linked conjugated poly(p‐phenylene ethynylene), together with a picture of a gel based on this highly fluorescent material. Cross‐linked conjugated polymers exhibit potentially interesting optoelectronic properties and can be processed into films and other shapes by simultaneous polymerization and object forming.Further details can be found in the Communication by E. Hittinger, A. Kokil, and C. Weder* on page 710.
Magnetic resonance imaging and single‐photon emission computed tomography changes in hypoglycemia‐induced chorea
Authors: Lai Shung‐Lon , Tseng Yu‐Lung , Hsu Ming‐Chin , Chen Shun‐Sheng 
Published: April 2004

AbstractWe present two case studies, one of generalized chorea and one of hemichorea, both after severe hypoglycemia episodes. Both cases showed hyperperfusion in their SPECT scans. The MRI and SPECT findings serve as clues regarding the role of basal ganglion dysfunction associated with chorea. © 2003 Movement Disorder Society
Is the rhythm of physiological tremor involved in cortico‐cortical interactions?
Authors: Raethjen Jan , Lindemann Michael , Morsnowski Andre , Dümpelmann Matthias , Wenzelburger Roland , Stolze Henning , Fietzek Urban , Pfister Gerd , Elger Christian E. , Timmer Jens , Deuschl Günther 
Published: April 2004

AbstractThe function of low‐frequency oscillations as correlates of physiological tremor in supplementary motor area (SMA) and M1 remains unclear. In epicortical recordings from M1 and SMA and surface electromyographic (EMG) recordings in an epileptic patient we found reproducibly significant coherence between all three recording sites in the 6‐ to 15‐Hz band. The partial coherence between SMA and muscle, however, was not significant. There was a constant phase shift between SMA and M1 indicating synchronized activity. We conclude that the cortical correlates of physiological tremor may be involved in linking different cortical motor centers and might therefore play a role in cortical motor planning. © 2003 Movement Disorder Society
Choreic syndrome and coeliac disease: A hitherto unrecognised association
Authors: Pereira Anthony C. , Edwards Mark J. , Buttery Philip C. , Hawkes Christopher H. , Quinn Niall P. , Giovannoni Gavin , Hadjivassiliou Marios , Bhatia Kailash P. 
Published: April 2004

AbstractCoeliac disease has been associated with a variety of neurological conditions, most frequently cerebellar ataxia and peripheral neuropathy. To date, chorea has not been associated with coeliac disease. We present the case histories of 4 individuals with coeliac disease and chorea (4 women, average age of onset of chorea 61 years). Unexpectedly, most of these patients showed a notable improvement in their motor symptoms after the introduction of a gluten‐free diet. © 2003 Movement Disorder Society
Association of cortical disinhibition with tic, ADHD, and OCD severity in Tourette syndrome
Authors: Gilbert Donald L. , Bansal Alok S. , Sethuraman Gopalan , Sallee Floyd R. , Zhang Jie , Lipps Tara , Wassermann Eric M. 
Published: April 2004

AbstractHyperkinetic disorders may involve excess excitatory output from thalamus to cerebral cortex. Case–control, neurophysiological studies in persons with Tourette Syndrome (TS), Attention Deficit Hyperactivity Disorder (ADHD), and Obsessive‐Compulsive Disorder (OCD) support this model. To compare the strength of association between motor cortex inhibition and tic, ADHD, and OCD severity in TS, we used transcranial magnetic stimulation to measure motor cortex inhibition in 36 children and adults with TS. Current symptom severity was assessed with standard clinical rating scales and compared with neurophysiological measures using correlational and multivariate regression analyses. Severity of ADHD symptoms and motor tics were associated significantly and independently with short interval intracortical inhibition (SICI) (r2 = 0.50; F[2,27] = 13.7; P < 0.001), particularly in subjects not taking neuroleptics (r2 = 0.68; F[2,17] = 17.8; P < 0.0001). The correlation of cortical disinhibition was greater with ADHD symptoms severity (r = 0.53; P = 0.003) than with tic severity (r = 0.42; P = 0.02), suggesting that in TS, the association between SICI and ADHD symptoms may be more consistent or direct than the association between SICI and tics. © 2004 Movement Disorder Society
Anti‐basal ganglia antibodies in PANDAS
Authors: Singer Harvey S. , Loiselle Christopher R. , Lee Olivia , Minzer Karen , Swedo Susan , Grus Franz H. 
Published: April 2004

AbstractAn autoimmune‐mediated mechanism involving molecular mimicry has been proposed for a variety of pediatric movement disorders that occur after a streptococcal infection. In this study, anti‐basal ganglia antibodies (ABGA) were measured in 15 children with the diagnosis of pediatric autoimmune neuropsychiatric disorder associated with streptococcal infection (PANDAS) and compared with those in 15 controls. ELISA and Western immunoblotting (WB) methods were used to detect ABGA against supernatant (S1), pellet (P2), and synaptosomal preparations from adult postmortem caudate, putamen, and globus pallidus. ELISA optical density values did not differ between PANDAS patients and controls across all preparations. Immunoblotting identified multiple bands in all subjects with no differences in the number of bands or their total density. Discriminant analysis, used to assess mean binding patterns, showed that PANDAS patients differed from controls only for the caudate S1 fraction (Wilks' λ = 0.0236, P < 0.0002), with PANDAS‐primarily tic subjects providing the greatest discrimination. Among the epitopes contributing to differences between PANDAS and control in the caudate S1 fraction, mean binding to the epitope at 183 kDa was the most different between groups. In conclusion, ELISA measurements do not differentiate between PANDAS and controls, suggesting a lack of major antibody changes in this disorder. Further immunoblot analyses using a caudate supernatant fraction are required to completely exclude the possibility of minor antibody repertoire differences in PANDAS subjects, especially in those who primarily have tics. © 2004 Movement Disorder Society
Does parkin play a role in the peripheral nervous system? A family report
Authors: Abbruzzese Giovanni , Pigullo Simona , Schenone Angelo , Bellone Emilia , Marchese Roberta , Di Maria Emilio , Benedetti Luana , Ciotti Paola , Nobbio Lucilla , Bonifati Vincenzo , Ajmar Franco , Mandich Paola 
Published: April 2004

AbstractTwo genes were identified for autosomal recessive forms of early onset Parkinson's disease: parkin and DJ‐1. We describe 2 siblings with EOPD due to parkin mutations and peripheral neuropathy, which presented as neuropathy with liability to pressure palsies (HNPP) in the index case. RT‐PCR experiments revealed that the parkin gene is expressed in sural nerves from both controls and patient with parkin‐related disease. Our findings support the view that parkin may play a role in the peripheral nervous system. © 2004 Movement Disorder Society
Ultra‐wideband TEM horn design for ground penetrating impulse radar systems
Authors: Turk Ahmet Serdar 
Published: April 2004

AbstractThe partial dielectric‐loaded TEM horn (PDTEM) structure, which maintains ultra‐wideband antenna characteristics over a bandwidth ratio greater than 20:1 in order to improve the impulse‐radiation characteristics for ground penetrating radar systems is described in this paper. It is shown that high‐gain and low‐input‐reflection levels over the operational band are attainable for TEM horns with proper dielectric, absorber, and resistive loadings. © 2004 Wiley Periodicals, Inc. Microwave Opt Technol Lett 41: 333–336, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20133
Experimental characteristics of a printed open‐slot antenna with reflector for PCS, DCS, and IMT‐2000
Authors: Jang Yong‐Woong 
Published: April 2004

AbstractIn this paper, we investigate a new rectangular‐fed printed open‐slot antenna (POSA) with reflector, which has the advantages of improved radiation‐pattern properties along with broad‐bandwidth characteristics. The measured bandwidth of the proposed POSA with reflector is approximately 47.6% (−10 dB ≥ S11), thus, it can be used for PCS, DCS, and IMT‐2000. But the measured bandwidth of the PCSA with reflector is approximately 46% (with VSWR ≤ 2.0). The tilt angle at maximum gain is enhanced by using a modified POSA with reflector for practical applications. The radiation pattern null and distortion of the open‐slot antenna exhibited better performances than those of the closed‐slot antenna. The back‐lobe level of the POSA with reflector also presented much better results than the PCSA with reflector. The proposed antenna obtained not only wider bandwidth but also better radiation patterns characteristics than the PCSA with reflector. © 2004 Wiley Periodicals, Inc. Microwave Opt Technol Lett 41: 348–350, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20138
Wave scattering with UV multilevel partitioning method for volume scattering by discrete scatterers
Authors: Tsang L. , Li Qin 
Published: April 2004

AbstractA UV multilevel partitioning method (UV‐MLP) is developed to solve the volume‐scattering problem. The method involves creating a rank table of transmitting and receiving block sizes and their separation. The table can be set up speedily using coarse‐coarse sampling. For a specific scattering problem with given geometry, the scattering structure is partitioned into multilevel blocks. By looking up the rank in the predetermined table, the impedance matrix for a given transmitting and receiving block is expressed as a product of U and V matrices. We illustrate the method for 2D volume scattering by discrete scatterers. Multiple scattering is cast into the Foldy–Lax equations of partial waves. We show that UV decomposition can be applied directly to the impedance matrix of partial waves of higher order than the usual lowest‐order Green's function. Numerical results are illustrated for randomly distributed cylinders that are one wavelength in diameter. For scattering by 1024 cylinders on a single PC processor with a 2.6‐GHz CPU and 2‐GB memory, only 14 CPU min are required to obtain the numerical solution. If subsectional volumetric discretization with the method of moments (MoM) is applied to this problem, the equivalent number of volumetric unknowns is 80,425. Furthermore, for 4096 cylinders that have 321,700 equivalent numbers of volumetric unknowns, it takes only 7.34 sec for one matrix‐vector multiplication. © 2004 Wiley Periodicals, Inc. Microwave Opt Technol Lett 41: 354–361, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20140
A novel monopole antenna with broad bandwidth
Authors: Wang Hongyu , Ruan Chenglu , Wang Qi 
Published: April 2004

AbstractA novel monopole antenna with two parasitic elements added is presented for broadband applications. The impedance and radiation characteristics of the antenna are investigated experimentally and numerically. For the proposed antenna, a bandwidth of 97.1% with |S11| < −10 dB is achieved, and omnidirectional radiation pattern is obtained. The results are very attractive for mobile‐communication systems. © 2004 Wiley Periodicals, Inc. Microwave Opt Technol Lett 41: 364–366, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20142
A planar meander‐line antenna for triple‐band operation of mobile handsets
Authors: Wu Jeun‐Wen , Lin Chun‐Ren , Lu Jui‐Han 
Published: April 2004

AbstractA planar meander‐line antenna consisting of three branch strips for very‐low‐profile GSM/DCS/PCS/WLAN triple‐band operation of mobile phones is presented. The branch strips are designed to operate as quarter‐wavelength structures at 900 and 1800 MHz, respectively, and the obtained impedance bandwidths cover the required bandwidths of the GSM (890–960 MHz), DCS/PCS (1710–1880/1850–1990 MHz), and WLAN (2400–2484 MHz) bands. The proposed antenna is 46.5 mm in width and 11 mm in height, and can be mounted on top of a mobile phone with a small distance of 2 mm to the ground plane, thus resulting in a very low profile of 13 mm (less than 4% of the wavelength at 900 MHz) from the ground plane for the proposed antenna in practical applications. The measured antenna‐radiation patterns are approximately omnidirectional at the three resonant frequencies. Peak antenna gains for operating frequencies across the GSM/DCS/PCS/WLAN triple bands are measured to be 1.1, 1.6, and 1.2 dBi, respectively, with gain variations within 0.5 dBi. © 2004 Wiley Periodicals, Inc. Microwave Opt Technol Lett 41: 380–386, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20146