bluuebunny/crossref_metadata_2025 huggingface dataset:
Aligned neurite bundles of granule cells regulate orientation of Purkinje cell dendrites by perpendicular contact guidance in two‐dimensional and three‐dimensional mouse cerebellar cultures
Authors: Nagata Isao , Ono Katsuhiko , Kawana Akio , Kimura‐Kuroda Junko
Published: September 2006

To identify structures that determine the 90° orientation of thin espalier dendritic trees of Purkinje cells with respect to parallel fibers (axonal neurite bundles of granule cells) in the cerebellar cortex, we designed five types of two‐dimensional and three‐dimensional cell and tissue cultures of cerebella from postnatal mice and analyzed the orientation of Purkinje cell dendrites with respect to neurite bundles and astrocyte fibers by immunofluorescence double or triple staining. We cultured dissociated cerebellar cells on micropatterned substrates and preformed neurite bundles of a microexplant culture two‐dimensionally and in matrix gels three‐dimensionally. Dendrites, but not axons, of Purkinje cells extended toward the neurites of granule cells and oriented at right angles two‐dimensionally to aligned neurite bundles in the three cultures. In a more organized explant proper of the microexplant culture, Purkinje cell dendrites extended toward thin aligned neurite bundles not only consistently at right angles but also two‐dimensionally. However, in the “organotypic microexplant culture,” in which three‐dimensionally aligned thick neurite bundles mimicking parallel fibers were produced, Purkinje cell dendrites often oriented perpendicular to the thick bundles three‐dimensionally. Astrocytes were abundant in all cultures, and there was no definite correlation between the presence of and orientation to Purkinje cell dendrites, although their fibers were frequently associated in parallel with dendrites in the organotypic microexplant culture. Therefore, Purkinje cells may grow their dendrites to the newly produced neurite bundles of parallel fibers in the cerebellar cortex and be oriented at right angles three‐dimensionally mainly via “perpendicular contact guidance.” J. Comp. Neurol. 499:274–289, 2006. © 2006 Wiley‐Liss, Inc.
Ultrastructure of synaptic input to medial olivocochlear neurons
Authors: Benson Thane E. , Brown M. Christian
Published: September 2006

Medial olivocochlear (MOC) neurons project from the brain to the cochlea to form the efferent limb of the MOC reflex. To study synaptic inputs to MOC neurons, we retrogradely labeled these neurons using horseradish peroxidase injections into the cochlea. Labeled neurons were identified in the ventral nucleus of the trapezoid body and documented with the light microscope before being studied with serial‐section electron microscopy. MOC somata and dendrites were innervated by three different types of synapses, distinguished as either having: 1) large, round synaptic vesicles and forming asymmetric contacts; 2) small, round vesicles plus a few dense core vesicles and forming asymmetric contacts; or 3) pleomorphic vesicles and forming symmetric contacts. The first two types were the most frequent on somata. Acetylcholinesterase‐stained material confirmed that the type containing large, round vesicles is most common on dendrites. We kept track of the synaptic terminals in serial sections and compiled them into three‐dimensional swellings. Swellings with large, round vesicles formed up to seven synapses per swelling, were largest in size, and sometimes formed complex arrangements engulfing spines of MOC neurons. Swellings with small, round vesicles formed up to four synapses per swelling. The morphology of this type of synapse, and the moderate sizes of the swellings forming it, suggests that it originates from posteroventral cochlear nucleus stellate/multipolar neurons. This input may thus provide the sound‐evoked input to MOC neurons that causes their reflexive response to sound. J. Comp. Neurol. 499:244–257, 2006. © 2006 Wiley‐Liss, Inc.
Automated virtual microscopy of gastric biopsies
Authors: Ficsor Levente , Varga Viktor , Berczi Lajos , Miheller Pal , Tagscherer Attila , Wu Mark Li‐cheng , Tulassay Zsolt , Molnar Bela
Published: September 2006

Background:

Automated virtual microscopy of specimens from gastrointestinal biopsies is based on cytometric parameters of digitized histological sections. To our knowledge, cytometric parameters of gastritis and of adenocarcinoma have yet to be fully characterized. Our objective was to classify gastritis and adenocarcinoma based on cytometric parameters. We hypothesized that automated virtual microscopy using this novel classification can reliably diagnose gastritis and adenocarcinoma.

Methods:

Routinely processed hematoxylin‐and‐eosin‐stained histological sections from specimens that showed normal mucosa (14 cases), gastritis (35 cases), and adenocarcinoma (30 cases) diagnosed by conventional optical microscopy were scanned and digitized at high resolution. Thirty‐eight cytometric parameters based on density and morphometry were applied to glands and superficial epithelium. Twelve cytometric parameters based on cytologic detail were applied to individual cells.

Results:

Statistically significant differences in cytometric parameters for normal mucosa, gastritis, and adenocarcinoma were found. The most discriminatory parameter was the ratio of the total number of cells to the number of interstitial cells. These differences correctly classified adenocarcinoma at 100% accuracy and overall correctness was 86%.

Conclusions:

We describe a novel method of analyzing gastric mucosal histology based on cytometric parameters. Automated virtual microscopy can be used to classify gastric mucosa as normal, gastritis, or adenocarcinoma with reasonable accuracy. Further research is necessary to determine whether automated virtual microscopy can subclassify gastric mucosal histology in greater detail. © 2006 International Society for Analytical Cytology
Prognostic value of neutrophils and NK cells in bronchoalveolar lavage of sarcoidosis
Authors: Tutor‐Ureta Pablo , Citores María J. , Castejón Raquel , Mellor‐Pita Susana , Yebra‐Bango Miguel , Romero Yolanda , Vargas Juan A.
Published: September 2006

Background:

Not all the patients with sarcoidosis need pharmacological therapy, and the decision to start therapy is based mainly on clinical conditions. The aim of this study was to evaluate the prognostic value of the leukocyte and lymphocyte subpopulations in the bronchoalveolar lavage fluid from these patients.

Methods:

Thirty‐three nonsmoking patients with sarcoidosis were included and classified based on the presence of Löfgren's syndrome (n = 11), the radiological stage (12 at Stage I, 17 at Stage II, and 4 at Stage III), and their follow‐up. Differential leukocyte subsets and the lymphocyte subpopulations were determined by flow cytometry.

Results:

The percentage of neutrophils was lower in patients with Löfgren's syndrome (P = 0.038) and in patients at Stage I (P = 0.002). Patients with a poor outcome had a higher percentage of neutrophils (P = 0.004) and NK cells (P = 0.023) than those with a stable disease. Finally, a higher percentage of NK cells was found in those patients who needed a steroid treatment (P = 0.012).

Conclusions:

Increased percentages of neutrophils and NK cells in the bronchoalveolar lavage fluid from patients with sarcoidosis are associated with a poor outcome and a higher probability to need steroids treatment. The percentage of neutrophils was also lower in patients with Löfgren's syndrome. © 2006 International Society for Analytical Cytology
Cytoadherence between endothelial cells and P. falciparum infected and noninfected normal and thalassemic red blood cells
Authors: Butthep P. , Wanram S. , Pattanapanyasat K. , Vattanaviboon P. , Fucharoen S. , Wilairat P.
Published: September 2006

Background:

Cytoadhesion of P. falciparum infected red blood cells (RBCs) to endothelial cells (ECs) is an important phenomenon that causes cerebral malaria in man. Reduced adhesion especially in thalassemia and hemoglobinopathies may be related to a protective mechanism against malaria in such people.

Methods:

The cytoadherence assay was performed using both conventional and floating conditions between ECs (ECV 304) and P. falciparum infected and noninfected RBCs from both normal and thalassemia subjects. In floating condition, RBC was fluorescently labeled with anti‐glycophorin A antibody, whereas EC was identified by surface expression of PECAM‐1, CD‐36, ICAM‐1, and E‐selectin. The condition of floating EC was similar to the condition for subcultivation as they can adhere or bind to any surface. The phosphatidylserine (PS) exposure was also determined by using flow cytometer.

Results:

The adhesion of noninfected heterozygous thalassemic RBCs (all genotypes) to ECs was significantly increased as compared with normal RBCs (P < 0.02). Interestingly, after P. falciparum infection, the number of normal RBCs bound to ECs was significantly increased as compared with noninfected RBCs (P < 0.01), whereas heterozygous thalassemic RBCs infected by P. falciparum showed no significant difference compared with noninfected RBCs. In addition, we found a similar level of PS exposure in normal and thalassemic infected RBCs, which was related to the cytoadherence phenomenon.

Conclusion:

The reduced adhesion between heterozygous thalassemic RBCs infected by P. falciparum to ECs provides an explanation for their protective mechanism against malaria, as increased adhesion is a high risk for cerebral malaria and nonbinding infected RBCs can be removed by the reticuloendothelial system and other mechanism(s) in vivo. © 2006 International Society for Analytical Cytology
Multi‐stage two‐leg bandwidth reservation and admission control for advance reservations with uncertain service duration
Authors: Sun Yeali S. , Tu Yung‐Cheng , Chang Chen Meng , Shih Wei‐Kuan
Published: September 2006

In traditional advance reservation (AR) service, resources were reserved for fixed scheduled periods at the time requests were admitted. When overtimes occurred, because of the reservation timeout, connections would be forced to terminate. For Internet AR applications like sports event casting and conference meetings such service disruption would be unfortunate and undesired for the viewers and participants. Further, taking into account that overtimes are often known almost at the last minute of the pre‐scheduled period, even if a connection extension request is submitted the probability that it is successful is unpredictable depending on the network load. In this paper, we study the problem of admission control and resource management for the AR service with uncertain service duration. An innovative multi‐stage two‐leg admission control and bandwidth management scheme is proposed. New performance measures—service quality indexes and reservation cost function are also defined for AR service. Through simulations, we show that the proposed scheme successfully provides service users a more predictive, affirmative service guarantee than conventional reservation schemes. Copyright © 2006 John Wiley & Sons, Ltd.
(Alkyl)‐ and (Alkyl)(alkylidene)(pentamethylcyclopentadienyl)tantalum Complexes
Authors: Galakhov Mikhail V. , Gómez Manuel , Gómez‐Sal Pilar , Velasco Patricia
Published: September 2006

Alkylation of [TaCp*Cl4] (Cp* = η5‐C5Me5) with 3 equiv. of MgCl(CH2SiMe3) gives the chloridotris(trimethylsilylmethyl) complex [TaCp*Cl(CH2SiMe3)3] (1). TaCp*Cl2Me2 reacts with 2 equiv. of LiR (R = CH2Ph, CH2SiMe3) to give the mixed alkyl derivatives [TaCp*Me2R2] (R = CH2Ph, 2; CH2SiMe3, 3). The dimethyldineopentyl complex [TaCp*Me2(CH2CMe3)2] (4) was obtained by reaction of TaCp*Cl2(CH2CMe3)2 with 2 equiv. of LiMe. The treatment of a toluene solution of TaCp*Cl2Me2 with 2 equiv. of neophyllithium in a standard vacuum line gave a mixture of three compounds, [{TaCp*Me2(CH2CMe2Ph)}2(μ‐O)] (5), [TaCp*Me2(CH2CMe2–o‐C6H4‐κ2C,C)] (6) and [TaCp*Me(CH2CMe2Ph)(CH2)] (7), which were identified by NMR spectroscopy. However, when the reaction was carried out under rigorously anhydrous conditions, only complexes 6 and 7 were isolated. A chlorido(trimethylsilylmethyl)(trimethylsilylmethylidene) complex [TaCp*Cl(CH2SiMe3)(CHSiMe3)] (8) was prepared by heating 1 at 60 °C, or by leaving it at room temperature for a long time. A 3:2 (9/10) mixture of [TaCp*MeR(CHSiMe3)] (R = CH2SiMe3, 9; Me, 10) was obtained by thermal treatment of 3, which was accompanied by the evolution of CH4 and SiMe4. However, irradiation of a [D6]benzene solution of 3 with a sun lamp gave a mixture of 9 and [TaCp*(CH2SiMe3)R(CH2)] (R = Me, 11; CH2SiMe3, 12) in a 2:1:1 (9/11/12) ratio. When a [D6]benzene solution of 4 was heated at 60 °C, a mixture of the (alkyl)(neopentylidene) derivatives [TaCp*MeR(CHCMe3)] (R = Me, 13; CH2CMe3, 14) in a 4:1 (13/14) ratio was detected by NMR spectroscopy, while irradiation with a sun lamp produced a mixture ofalkylidene complexes [TaCp*(CH2CMe3)R(CH2)] (R = Me, 15; CH2CMe3, 16) in a 3:1 (15/16) ratio. On the other hand, the alkylation of TaCp*Cl2(CH2CMe3)2 with 2 equiv. of LiCH2SiMe3 gave the (alkyl)(alkylidene) complex [TaCp*(CH2CMe3)(CH2SiMe3)(CHCMe3)] (17) with the elimination of SiMe4, whereas the treatment of TaCp*Cl2(CH2SiMe3)2 with the appropriate reagent gave [TaCp*(CH2R)(CH2SiMe3)(CHR′)] (R = R′ = Ph, 18; R = CMe2Ph, R′ = SiMe3, 19) with the elimination of SiMe4 and CMe3Ph, respectively. All compounds were studied by IR and NMR spectroscopy, and the molecular structures of complexes 1, 4 and 5 were determined by X‐ray diffraction methods. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)
Synthesis of Deoxygenated Disaccharide Precursors for Modified Lipid II Synthesis
Authors: Sun De‐Qun , Busson Roger , Herdewijn Piet
Published: September 2006

The synthesis of novel deoxygenated disaccharide precursors for modified lipid II synthesis is described. The 3‐ and 4‐deoxy‐GlcNAc donors were obtained, respectively, by radical reduction of the iodo derivative by TBTH/AIBN and hydrogen reduction of the triflate using a borohydride reagent (nBu4NBH4). O‐Glycosylation of the acceptor, promoted by NIS/TMSOTf, led to the 3‐ and 4‐deoxygenated disaccharides. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)
Long‐Range Effects in the Metalation/Boronation of Functionalized 1,4‐Dihalobenzenes
Authors: Luliński Sergiusz , Serwatowski Janusz , Zaczek Anna
Published: September 2006

The lithiation/boronation of 1,4‐dihalobenzenes (Hal = F, Cl, Br) bearing various functional groups in the 2‐position was investigated using lithium diisopropylamide (LDA) as the metalating agent and trialkyl borate B(OR)3 (R = Et, iPr) as the electrophile. It was demonstrated that sufficient steric hindrance precludes effective ortho‐lithiation at the 3‐position. In such cases, a strong meta‐directing effect of an oxygen‐ or sulfur‐based substituent (OMe, OSiMe3, SMe), resulting in the preferred formation of 2,6‐disubstituted 1,4‐dihalobenzenes was observed. Moreover, competition experiments using 2,3‐bifunctional 1,4‐dihalobenzenes were performed to determine the relative meta‐directing ability of carboxylate or fluorine in competition with a methoxy group. A significant buttressing effect is responsible for the course of metalation of 2‐(dimethoxymethyl)‐1,4‐dihalobenzenes (Hal = Cl, Br). (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)
Electrochemiluminescent Determination of Chlorphenamine Maleate Based on Ru(bpy)$\rm{ {_{3}^{2+}}}$ Immobilized in a Nano‐Titania/Nafion Membrane
Authors: Song Hongjie , Zhang Zhujun , Wang Fen
Published: September 2006

The immobilization of tris(2,2'‐bipyridyl)ruthenium(II) [Ru(bpy)$\rm{ {_{3}^{2+}}}$] in a TiO2/Nafion nanocomposites membrane modified glassy carbon electrode (GCE) was achieved via both an ion‐exchange process and hydrophobic interactions .The surface‐confined Ru(bpy)$\rm{ {_{3}^{2+}}}$ shows good electrochemical and photochemical activities. The Ru(bpy)$\rm{ {_{3}^{2+}}}$ underwent reversible surface process and reacted with chlorphenamine maleate (CPM) to produce electrochemiluminescence. The modified electrode was used for the ECL determination of CPM. It showed good linearity in the concentration range from 2×10−8 g/mL to 1×10−6 g/mL (R=0.9995) with a detection 6×10−9 g/mL (S/N=3). The relative standard derivation (n=11) was 2%. This method is developed for the determination of CPM with simplicity and high sensitivity.
Voltammetric Behavior of Antileukemia Drug Glivec. Part I – Electrochemical Study of Glivec
Authors: Diculescu Victor Constantin , Vivan Marilene , Brett Ana Maria Oliveira
Published: September 2006

The electrochemical behavior of the antileukemia drug glivec was investigated at a glassy carbon electrode (GCE). The oxidation is a complex, pH‐dependent, irreversible electrode process involving the transfer of 2 electrons and 2 protons and the formation of an electroactive product, Pglivec, which strongly adsorbs on the GCE surface and undergoes reversible oxidation. The adsorption of Pglivec at the GCE surface yields a compact monolayer that inhibits further oxidation of glivec. The electrochemical reduction is a simple pH dependent irreversible process involving the transfer of 2 electrons and 2 protons and occurs with the formation of a nonelectroactive product. The diffusion coefficient of glivec was calculated to be DO=7.35×10−6 cm2 s−1 in pH 4.5 0.1 M acetate buffer.
Amperometric Glucose Biosensors Based on Integration of Glucose Oxidase onto Prussian Blue/Carbon Nanotubes Nanocomposite Electrodes
Authors: Zhu Liande , Zhai Jiangli , Guo Yingna , Tian Chunyuan , Yang Ruilan
Published: September 2006

Nanosized Prussian blue (PB) particles were synthesized with a chemical reduction method and then the PB nanoparticles were assembled on the surface of multiwall carbon nanotubes modified glassy carbon electrode (PB/MWNTs/GCE). The results showed that the PB/MWNTs nanocomposite exhibits a remarkably improved catalytic activity towards the reduction of hydrogen peroxide. Glucose oxidase (GOD) was immobilized on the PB/MWNTs platform by an electrochemically polymerized o‐phenylenediamine (OPD) film to construct an amperometric glucose biosensor. The biosensor exhibited a wide linear response up to 8 mM with a low detection limit of 12.7 μM (S/N=3). The Michaelis–Menten constant Km and the maximum current imax of the biosensor were 18.0 mM and 4.68 μA, respectively. The selectivity and stability of the biosensor were also investigated.
A new PCR‐CGE (size and color) method for simultaneous detection of genetically modified maize events
Authors: Nadal Anna , Coll Anna , La Paz Jose‐Luis , Esteve Teresa , Pla Maria
Published: September 2006

We present a novel multiplex PCR assay for simultaneous detection of multiple transgenic events in maize. Initially, five PCR primers pairs specific to events Bt11, GA21, MON810, and NK603, and Zea mays L. (alcohol dehydrogenase) were included. The event specificity was based on amplification of transgene/plant genome flanking regions, i.e., the same targets as for validated real‐time PCR assays. These short and similarly sized amplicons were selected to achieve high and similar amplification efficiency for all targets; however, its unambiguous identification was a technical challenge. We achieved a clear distinction by a novel CGE approach that combined the identification by size and color (CGE‐SC). In one single step, all five targets were amplified and specifically labeled with three different fluorescent dyes. The assay was specific and displayed an LOD of 0.1% of each genetically modified organism (GMO). Therefore, it was adequate to fulfill legal thresholds established, e.g., in the European Union. Our CGE‐SC based strategy in combination with an adequate labeling design has the potential to simultaneously detect higher numbers of targets. As an example, we present the detection of up to eight targets in a single run. Multiplex PCR‐CGE‐SC only requires a conventional sequencer device and enables automation and high throughput. In addition, it proved to be transferable to a different laboratory. The number of authorized GMO events is rapidly growing; and the acreage of genetically modified (GM) varieties cultivated and commercialized worldwide is rapidly increasing. In this context, our multiplex PCR‐CGE‐SC can be suitable for screening GM contents in food.
An optimized microchip electrophoresis system for mutation detection by tandem SSCP and heteroduplex analysis for p53 gene exons 5–9
Authors: Hestekin Christa N. , Jakupciak John P. , Chiesl Thomas N. , Kan Cheuk Wai , O'Connell Catherine D. , Barron Annelise E.
Published: September 2006

With the complete sequencing of the human genome, there is a growing need for rapid, highly sensitive genetic mutation detection methods suitable for clinical implementation. DNA‐based diagnostics such as single‐strand conformational polymorphism (SSCP) and heteroduplex analysis (HA) are commonly used in research laboratories to screen for mutations, but the slab gel electrophoresis (SGE) format is ill‐suited for routine clinical use. The translation of these assays from SGE to microfluidic chips offers significant speed, cost, and sensitivity advantages; however, numerous parameters must be optimized to provide highly sensitive mutation detection. Here we present a methodical study of system parameters including polymer matrix, wall coating, analysis temperature, and electric field strengths on the effectiveness of mutation detection by tandem SSCP/HA for DNA samples from exons 5–9 of the p53 gene. The effects of polymer matrix concentration and average molar mass were studied for linear polyacrylamide (LPA) solutions. We determined that a matrix of 8% w/v 600 kDa LPA provides the most reliable SSCP/HA mutation detection on chips. The inclusion of a small amount of the dynamic wall‐coating polymer poly‐N‐hydroxyethylacrylamide in the matrix substantially improves the resolution of SSCP conformers and extends the coating lifetime. We investigated electrophoresis temperatures between 17 and 35°C and found that the lowest temperature accessible on our chip electrophoresis system gives the best condition for high sensitivity of the tandem SSCP/HA method, especially for the SSCP conformers. Finally, the use of electrical fields between 350 and 450 V/cm provided rapid separations (<10 min) with well‐resolved DNA peaks for both SSCP and HA.
Effects of scents on airborne microbes, part I: thymol, eugenol, trans‐cinnamaldehyde and linalool
Authors: Krist Sabine , Halwachs Lydia , Sallaberger Georg , Buchbauer Gerhard
Published: September 2006

Four aroma chemicals, thymol, eugenol, trans‐cinnamaldehyde and linalool, were tested for their influence on total microbial count (bacteria, yeasts and moulds) in air. After determining both the total microbial count (TC) and the total count of yeasts and moulds (YM) of airborne microbes in a selected testing room, using a RCS Air Sampler, each of the aroma chemicals was vapourized in four different concentrations, 5, 2.5, 1.5 and 0.5 mg/m3. After a residence time of 15 min, the germ count in the testing room was measured again, using the air sampler. Each tested substance in any concentration showed a reduction of total microbial count as well as a reduction of total count of yeasts and moulds in the air and thus contributes to abating infection hazard for humans. The most effective concentrations for each substance were as follows. For total microbial count reduction: thymol, 1.5 mg/m3 (69.50% reduction); eugenol, 1.5 mg/m3 (69.40% reduction); trans‐cinnamaldehyde, 1.5 mg/m3 (65.93% reduction); and linalool, 2.5 mg/m3 (69.92% reduction). For total count reduction of yeasts and moulds: thymol, 0.5 mg/m3 (50.60%); eugenol, 1.5 mg/m3 (58.31%); trans‐cinnamaldehyde, 2.5 mg/m3 (46.19%); and linalool, 1.5 mg/m3 (50.25%). Copyright © 2006 John Wiley & Sons, Ltd.
Mutations in the MYB intron I regulatory sequence increase transcription in colon cancers
Authors: Hugo Honor , Cures Alina , Suraweera Nirosha , Drabsch Yvette , Purcell Damian , Mantamadiotis Theo , Phillips Wayne , Dobrovic Alex , Zupi Gabriella , Gonda Thomas J. , Iacopetta Barry , Ramsay Robert G.
Published: September 2006

Although MYB overexpression in colorectal cancer (CRC) is known to be a prognostic indicator for poor survival, the basis for this overexpression is unclear. Among multiple levels of MYB regulation, the most dynamic is the control of transcriptional elongation by sequences within intron 1. The authors have proposed that this regulatory sequence is transcribed into an RNA stem‐loop and 19‐residue polyuridine tract, and is subject to mutation in CRC. When this region was examined in colorectal and breast carcinoma cell lines and tissues, the authors found frequent mutations only in CRC. It was determined that these mutations allowed increased transcription compared with the wild type sequence. These data suggest that this MYB regulatory region within intron 1 is subject to mutations in CRC but not breast cancer, perhaps consistent with the mutagenic insult that occurs within the colon and not mammary tissue. In CRC, these mutations may contribute to MYB overexpression, highlighting the importance of noncoding sequences in the regulation of key cancer genes. © 2006 Wiley‐Liss, Inc.
Challenge with innate and protein antigens induces CCR7 expression by microglia in vitro and in vivo
Authors: Dijkstra I. M. , de Haas A. H. , Brouwer N. , Boddeke H. W. G. M. , Biber K.
Published: September 2006

Since activated microglia are able to phagocytose damaged cells and subsequently express major histocompatibility complex class II (MHC‐II) and co‐stimulatory proteins, they are considered to function as antigen presenting cells (APCs) in the central nervous system. The maturation and migratory potential of professional APCs is associated with the expression of chemokine receptor CCR7. We therefore investigated whether the immunological activation of microglia induces CCR7 expression. We here present that activation of cultured microglia by both the innate antigen lipopolysaccharide and protein antigen ovalbumin rapidly induces CCR7 expression, accompanied by increased MHC‐II expression. Moreover, it is shown that CCR7 expression in IBA‐1 positive cells is induced during the symptom onset and progression of experimental autoimmune encephalomyelitis, a rodent model for multiple sclerosis. These results suggest that microglia express CCR7 under specific inflammatory conditions, corroborating the idea that microglia develop into APCs with migratory potential toward lymphoid chemokines. © 2006 Wiley‐Liss, Inc.
Post‐wildfire changes in suspended sediment rating curves: Sabino Canyon, Arizona
Authors: Desilets Sharon L. E. , Nijssen Bart , Ekwurzel Brenda , Ferré Ty P. A.
Published: September 2006

Wildfire has been shown to increase erosion by several orders of magnitude, but knowledge regarding short‐term variations in post‐fire sediment transport processes has been lacking. We present a detailed analysis of the immediate post‐fire sediment dynamics in a semi‐arid basin in the southwestern USA based on suspended sediment rating curves. During June and July 2003, the Aspen Fire in the Coronado National Forest of southern Arizona burned an area of 343 km2. Surface water samples were collected in an affected watershed using an event‐based sampling strategy. Sediment rating parameters were determined for individual storm events during the first 18 months after the fire. The highest sediment concentrations were observed immediately after the fire. Through the two subsequent monsoon seasons there was a progressive change in rating parameters related to the preferential removal of fine to coarse sediment. During the corresponding winter seasons, there was a lower supply of sediment from the hillslopes, resulting in a time‐invariant set of sediment rating parameters. A sediment mass‐balance model corroborated the physical interpretations. The temporal variability in the sediment rating parameters demonstrates the importance of storm‐based sampling in areas with intense monsoon activity to characterize post‐fire sediment transport accurately. In particular, recovery of rating parameters depends on the number of high‐intensity rainstorms. These findings can be used to constrain rapid assessment fire‐response models for planning mitigation activities. Copyright © 2006 John Wiley & Sons, Ltd.
Vaccination of advanced prostate cancer patients with PSCA and PSA peptide‐loaded dendritic cells induces DTH responses that correlate with superior overall survival
Authors: Thomas‐Kaskel Anna‐K. , Zeiser Robert , Jochim Rosa , Robbel Christian , Schultze‐Seemann Wolfgang , Waller Cornelius F. , Veelken Hendrik
Published: September 2006

Prostate stem cell antigen (PSCA) and prostate‐specific antigen (PSA) are overexpressed in most prostate cancers. PSCA‐ and PSA‐derived, HLA‐A2 binding peptides are specific targets for T‐cell responses in vitro. A phase I/II trial was performed to demonstrate feasibility, safety and induction of antigen‐specific immunity by vaccination with dendritic cells (DC) presenting PSCA and PSA peptides in patients with hormone‐ and chemotherapy‐refractory prostate cancer. Patients received 4 vaccinations with a median of 2.7 × 107 peptide‐loaded mature DC s.c. in biweekly intervals. Clinical responses were assessed 2 weeks after the 4th vaccination. Immune monitoring was performed by DTH and HLA multimer analysis. Twelve patients completed vaccination without relevant toxicities. Six patients had stable disease after 4 vaccinations. One patient had a complete disappearance of lymphadenopathy despite rising PSA. Four patients with SD and 1 progressor developed a positive DTH after the 4th vaccination. With a median survival of all patients of 13.4 months, DTH‐positivity was associated with significantly superior survival (p = 0.003). HLA tetramer analysis detected high frequencies of peptide‐specific T cells after 2 vaccinations in 1 patient who was also the sole responder to concomitant hepatitis B vaccination as an indicator of immune competence and survived 27 months after start of vaccination. Vaccination with PSA/PSCA peptide‐loaded, autologous DCs may induce cellular responses primarily in immunocompetent patients, which appear to be associated with clinical benefit. Testing of DC‐based vaccination is warranted for patients at earlier stages of prostate cancer. © 2006 Wiley‐Liss, Inc.
Weichselian Late Pleniglacial surface winds over northwest and central Europe: a model–data comparison
Authors: Renssen H. , Kasse C. , Vandenberghe J. , Lorenz S. J.
Published: September 2006

Reconstructions of the Weichselian Late Pleniglacial wind direction in northwest and central Europe are reviewed and compared with palaeoclimate simulations performed with an atmospheric general circulation model. These reconstructions are based on proxy data containing information on former wind directions, such as relic dune forms, sediments and wind‐polished rock surfaces. The objective is to investigate whether: (1) the proxy information is internally consistent; and (2) in agreement with the model simulations. We find a general consensus in the proxy‐based reconstructions, indicating a dominant westerly to northwesterly wind in winter during the Late Pleniglacial. The model results indicate over the study area an atmospheric circulation in winter that is dominated by southwesterly to west‐northwesterly winds, which are stronger than the southwesterly winds in the present‐day climate. The main driving factors behind the anomalous atmospheric circulation in the Late Pleniglacial are the Laurentide Ice Sheet and a colder North Atlantic Ocean with a relatively extensive sea‐ice cover, leading to an eastward relocation of the Icelandic Low and an enhanced pressure gradient over northwest Europe. The minor difference in Late Pleniglacial wind direction between the reconstructions and model can be explained by a combination of uncertainties in the proxy data and the relatively low spatial resolution of the applied climate model. Copyright © 2006 John Wiley & Sons, Ltd.
Raman scattering characterization of well‐aligned IrO2 nanocrystals grown on sapphire substrates via reactive sputtering
Authors: Korotcov Alexandru , Hsu Hung‐Pin , Huang Ying‐Sheng , Tsai Dah‐Shyang
Published: September 2006

Raman spectroscopy (RS) was used for the characterization of well‐aligned IrO2 nanocrystals (NCs) grown on sapphire substrates with different orientations via reactive magnetron sputtering. Three Raman‐active modes, Eg, B2g and A1g, were observed in the range 500–800 cm−1. The intensity of certain modes depended on the orientation of NCs and followed the selection rules reasonably well. The result indicates the possibility of determining the preferred growth direction of NCs using RS. Raman spectra show red shifts and peak broadening of the IrO2 signatures with respect to those of the bulk counterpart. The red shifts and asymmetric broadening of the Raman line shapes of the NCs were analyzed by a modified spatial correlation (MSC) model, which included a factor of stress‐induced shift. The MSC model showed that the effects of stress and nanometric size could be separated by analyzing the observed Raman features. The usefulness of experimental RS together with the MSC model analysis as a structural and residual stress characterization technique for NCs is demonstrated. Copyright © 2006 John Wiley & Sons, Ltd.
Chemical modification and surface reactions on carbon fibers studied by SERS
Authors: Xu Bing , Lu Yun
Published: September 2006

Carbon fibers were modified by reacting with maleic anhydride (MA) and oxidation in nitric acid to alter their inert nature. Bismaleimide, acting as a model compound of polyimide, was chosen to react with the surface‐active carbon fibers. Surface‐enhanced Raman scattering was performed by chemically depositing Ag colloids on different carbon fiber samples, including raw, modified and post‐reaction materials. The obtained enhanced Raman spectra explained the surface chemistry of the different carbon fiber samples and their further interaction with bismaleimide. The results could serve as a guide for the design of functional groups on carbon fibers and the manufacture of the carbon‐fiber‐reinforced polyimide matrix composites. Moreover, the effect of different laser powers and laser irradiation times on the carbon fiber surface was studied and is discussed. Copyright © 2006 John Wiley & Sons, Ltd.
Polarization coherent anti‐stokes Raman scattering using noisy light
Authors: Weisel Lindsay R. , Ta Thao , Booth Eric C. , Ulness Darin J.
Published: September 2006

Several polarization studies on the noisy light version of coherent anti‐Stokes Raman scattering (CARS) exist in the literature. However, the full advantages of polarization CARS (P‐CARS), which are so useful in conventional and short‐pulse CARS methods, have not yet been exploited in the noisy light version. This work presents experimental realization of fully functional P‐CARS using noisy light. Several examples demonstrate the advantages brought by P‐CARS. This includes the ‘classic’ example of benzene in carbon tetrachloride. Also presented are the carbon–carbon double bond stretches in acrylonitrile and 1‐hexene. An interesting, and not fully understood, detection polarization angle dependence is discussed. Applications to an m‐xylene/benzene mixture and an alkaline solution of the amino acid phenylalanine are presented. Copyright © 2006 John Wiley & Sons, Ltd.
Spectroscopic and ab initio characterization of the conformational states of the bis(perfluoro‐ ethanesulfonyl)imide anion (BETI−)
Authors: Grondin J. , Talaga D. , Lassègues J. C. , Johansson P. , Henderson W. A.
Published: September 2006

Ab initio calculations were combined with infrared and Raman studies to spectroscopically distinguish the two conformers of the BETI− or bis(perfluoroethanesulfonyl)imide anion, [N(SO2C2F5)2]−, as was previously done for [N(SO2CF3)2]−, the TFSI− anion. BETI− is predicted to exist, as does TFSI−, in two conformational states of C2 and C1 symmetries, the former being more stable by about 6 kJ mol−1. This conformational isomerism produces weak Raman splittings that can be resolved only at low temperatures. Thus, solutions of LiBETI with glymes cooled down to 113 K exhibit a very intense Raman doublet at ∼745–740 cm−1 characteristic of a quenched conformational equilibrium between the C2 and C1 conformers. Annealing of the (G3)2:LiBETI solvate, where G3 is triglyme, leads to an ordered crystalline phase with all the anions in the C2 conformation, as in the reference salt Me4NBETI. This conclusion cannot be extended to all the systems in which the BETI− anion interacts weakly with the cation, however, since the diglyme solvate, (G2)2:LiBETI, contains both C1 and C2 anion conformers (in 2:1 ratio) at low temperatures independent of the sample's thermal history. The conformational splittings are larger in infrared, as illustrated by two absorption bands at 601 and 615 cm−1 associated with the C2 and C1 anion conformers, respectively. It is possible to follow the relative intensities of these bands in a LiBETI solution with diglyme above room temperature up to 387 K. The C2 conformer is found to be more stable than C1 by 4.7 ± 0.7 kJ mol−1. Copyright © 2006 John Wiley & Sons, Ltd.
Determination of multiclass pesticide residues in apple juice by gas chromatography–mass spectrometry with large‐volume injection
Authors: Wang Jian‐Hua , Zhang Yi‐Bing , Wang Xiu‐Lin
Published: September 2006

This study presents two GC–MS SIM methods, in combination with large‐volume injection programmed‐temperature vaporization (LVI‐PTV) injection, for the determination of 141 pesticide residues in apple juice. The sample was extracted with ACN, and coextractives were removed with primary/secondary amine sorbent. ACN extract (20 μL) was injected into a PTV injection port in solvent vent mode, and the pesticides were determined by GC–MS using retention time locking software. Deuterium‐labeled pesticides (surrogate standards) were used for analytical quality control. In the validation experiments, pesticides recoveries were found to be 70–121% with RSDs of 4.6–21% (n = 6).
Molecular imprinting of natural flavonoid antioxidants: Application in solid‐phase extraction for the sample pretreatment of natural products prior to HPLC analysis
Authors: Theodoridis Georgios , Lasáková Martina , Škeříková Veronika , Tegou Andromachi , Giantsiou Nicoletta , Jandera Pavel
Published: September 2006

As shown in the past years, SPE based on molecularly imprinted polymers (MIPs) may provide significant enhancement of selectivity in sample preparation and analyte preconcentration. The objective of this work was the fabrication of MIPs for the specific adsorption of rutin and quercetin. The two flavonoids were used as the template molecules for the preparation of MIP phases in a self‐assembly (noncovalent) approach. The produced MIPs were validated with regard to the imprinting efficiency as media for LC and SPE. The retention behavior of several flavonoid compounds was studied using as stationary phases imprinted, control nonimprinted polymers, and commercial silica‐based materials. MIPs were applied as materials for the selective SPE and preconcentration of the flavonoids from white and red wine, orange juice, and tea. The collected fractions were analyzed by high‐pressure LC. MIP‐SPE facilitated specific analyte isolation and effective sample clean‐up. The results show that molecularly imprinted SPE can be a useful tool for the simple, selective, and cost‐effective pretreatment of samples containing natural antioxidants.
Determination of the 2,3‐pentadienedioic acid enantiomer interconversion energy barrier 1. Classical kinetic approach
Authors: Májek Pavel , Mydlová Janka , Krupcík Jan , Lehotay Jozef , Armstrong Daniel. W. , Cotton F. Albert
Published: September 2006

A classical kinetic method was used to determine the energy barrier for the interconversion of 2,3‐pentadienedioic acid enantiomers. Each individual enantiomer was isolated by collecting the appropriate peaks from the HPLC enantiomeric separation, of racemic 2,3‐pentadienedioic acid. The isolated enantiomers were racemized at 22°C using various interconversion times. The ratio of enantiomers in each reaction solution was determined by HPLC at 22°C. The corresponding peak areas of the enantiomers and the interconversion times obtained from the HPLC chromatograms were used to calculate both the interconversion rate constants describing (+) → (–) and (–) → (+) interconversions as well as the energy barriers. It was confirmed that the interconversion of 2,3‐pentadienedioic acid enantiomers is a first‐order kinetic reaction. Both semiempirical and ab initio methods were used to explore the mechanism of the interconversion of 2,3‐pentadienedioic acid enantiomers, and to calculate the interconversion energy barrier. Comparison of the interconversion energy barriers found by the ab initio method (ΔG# = 110.7 kJ/mol) and by classical kinetics in the mobile phase solution at 22°C (ΔGapp = 93.9 ± 0.2 kJ/mol) shows a difference which may be attributed to the different conditions assumed in the theoretical calculation (i. e., a gaseous state) and the actual experimental conditions (i. e., liquid solution) and a possible catalytic effect of the solution composition.
NR4A2 genetic variation in sporadic Parkinson's disease: A genewide approach
Authors: Healy Daniel G. , Abou‐Sleiman Patrick M. , Ahmadi Kourosh R. , Gandhi Sonia , Muqit Miratul M. , Bhatia Kailash P. , Quinn Niall P. , Lees Andrew J. , Holton Janice L. , Revesz Tamas , Wood Nicholas W.
Published: September 2006

The NR4A2 gene, which may cause autosomal dominant Parkinson's disease (PD), has also been reported to be a susceptibility factor for sporadic PD. Here, we use a haplotype‐tagging approach in 802 PD patients and 784 controls and demonstrate that common genetic variation, including NR4A2 haplotypes, does not influence the risk of PD in the Caucasian population. © 2006 Movement Disorder Society
Direct medical costs associated with Parkinson's disease: A population‐based study
Authors: Leibson Cynthia L. , Long Kirsten Hall , Maraganore Demetrius M. , Bower James H. , Ransom Jeanine E. , O'Brien Peter C. , Rocca Walter A.
Published: September 2006

The objective was to provide population‐based estimates of incremental medical costs associated with Parkinson's disease (PD) from onset forward. All Olmsted County, Minnesota, residents with confirmed PD onset from 1987 through 1995 (n = 92) and one age‐ and sex‐matched non‐PD referent subject per case were identified with retrospective record review and followed in provider‐linked billing data for direct medical costs (excluding outpatient pharmaceutical costs) from 1 year before index (i.e., year of symptom onset) through 10 years after index. Costs for each referent subject were subtracted from those for his/her matched case. Tests for statistical significance used Wilcoxon signed ranks. Preindex costs were similar [median difference in annual costs (MD) = −$3; P = 0.59]. One year post index, PD subjects exhibited borderline significantly higher costs compared to referent subjects (MD = $581; P = 0.052); the difference diminished over 5 years (MD = $118; P = 0.82). By 5 to 10 years, however, PD subjects exhibited significantly higher costs (MD = $1,146; P = 0.01). Over the full 10 years, excess costs were concentrated among PD subjects without rest tremor (MD = $2,261, P < 0.01, for those without tremor and −$229, P = 0.99, for those with tremor). These population‐based estimates of PD‐associated direct medical costs from onset forward can uniquely inform policy decisions and cost–effectiveness research. © 2006 Movement Disorder Society
Carcinogenicity of 2,3,7,8‐tetrachlorodibenzo‐p‐dioxin in experimental models
Authors: Knerr Stefanie , Schrenk Dieter
Published: September 2006

The contaminant 2,3,7,8‐tetrachlorodibenzo‐p‐dioxin (TCDD) is a prototype compound of a whole class of halogenated aromatic hydrocarbons termed ‘dioxinlike’ contaminants present in food, human tissue, mothers milk, and environmental samples. Among the various adverse effects caused by TCDD in animal experiments, its carcinogenic effects caused particular concern. In rodents, long‐term TCDD treatment leads to the development of tumors of the liver, thyroid, lung, skin, oral cavity and other sites. The occurrence of liver tumors mainly observed in female rats has been used as a basis for quantitative cancer risk assessment for TCDD. TCDD does not behave like a ‘complete carcinogen’, i. e. no DNA binding of the parent compound or metabolites thereof could be detected. However, enhanced oxidative damage of hepatic DNA was observed, probably resulting from a dramatic induction of cytochrome P450 enzymes, which are under the regulatory, transcriptional control of the TCDD‐activated aryl hydrocarbon receptor. The marked enhancement of TCDD‐related oxidative liver DNA damage in rats by estrogens warrants further mechanistic investigation. Furthermore, TCDD acts as a tumor promoter, i. e. it facilitates the growth of putative preneoplastic hepatic lesions after initiation with a complete carcinogen. The mechanisms underlying this effect may be related to altered intracellular signaling involving pronounced changes in the phosphorylation pattern of proteins regulating growth and apoptosis. These effects are thought to result in an enhanced survival of preneoplastic cells, some of which can undergo further steps on the way to malignancy. In summary, a better understanding of the mechanisms of the carcinogenicity of TCDD is mandatory to provide a rational basis for a better inter‐species extrapolation. The final aim of these efforts is a more reliable risk assessment for the carcinogenic potency of the class of dioxinlike contaminants in humans.
Comparison of chronic toxicity and carcinogenicity of 2,3,7,8‐tetrachlorodibenzo‐p‐dioxin (TCDD) in 2‐year bioassays in female Sprague‐Dawley rats
Authors: Walker Nigel J. , Wyde Michael E. , Fischer Lawrence J. , Nyska Abraham , Bucher John R.
Published: September 2006

The cancer bioassay for 2,3,7,8‐tetrachlorodibenzo‐p‐dioxin (TCDD) conducted by the Dow Chemical company in the mid 70s has been used extensively for conducting quantitative cancer risk assessments for human exposure to TCDD. More recently the National Toxicology Program (NTP) conducted a cancer bioassay of similar design as part of its evaluation of the dioxin toxic equivalency factor methodology. This report compares the design and the results of these two cancer bioassays. This comparison confirms, in most cases, previously published and widely used carcinogenic response characteristics with respect to dose, time course, organ selectivity, tumor type and maximum intensity of TCDD‐induced carcinogenicity and toxicity in the Sprague‐Dawley rat. Specifically, increases in the incidences of neoplasms were seen in both studies in the liver, lung and oral mucosa. The most notable difference was the significant increase in the incidence of cholangiocarcinoma of the liver seen in the NTP study but not in the Dow study. The experimental designs for the two studies are similar but some protocol parameters differed, such as vehicle, dosing schedule, diet and rat sub‐strain utilized. Differences in the shapes of the dose response curves for several neoplasms were noted between the studies, with the NTP study showing non‐linearity for all neoplasms. This may result from differences in the experimental protocols as well as divergence in the biological behavior of the different stocks of Sprague‐Dawley rat strains used.