bluuebunny/crossref_metadata_2025 huggingface dataset:
Serotonin Shifts First-Spike Latencies of Inferior Colliculus Neurons
Authors: Hurley Laura M. , Pollak George D.
Published: August 2005

Many studies of neuromodulators have focused on changes in the magnitudes of neural responses, but fewer studies have examined neuromodulator effects on response latency. Across sensory systems, response latency is important for encoding not only the temporal structure but also the identity of stimuli. In the auditory system, latency is a fundamental response property that varies with many features of sound, including intensity, frequency, and duration. To determine the extent of neuromodulatory regulation of latency within the inferior colliculus (IC), a midbrain auditory nexus, the effects of iontophoretically applied serotonin on first-spike latencies were characterized in the IC of the Mexican free-tailed bat. Serotonin significantly altered the first-spike latencies in response to tones in 24% of IC neurons, usually increasing, but sometimes decreasing, latency. Serotonin-evoked changes in latency and spike count were not always correlated but sometimes occurred independently within individual neurons. Furthermore, in some neurons, the size of serotonin-evoked latency shifts depended on the frequency or intensity of the stimulus, as reported previously for serotonin-evoked changes in spike count. These results support the general conclusion that changes in latency are an important part of the neuromodulatory repertoire of serotonin within the auditory system and show that serotonin can change latency either in conjunction with broad changes in other aspects of neuronal excitability or in highly specific ways.
Trafficking of GABAAReceptors, Loss of Inhibition, and a Mechanism for Pharmacoresistance in Status Epilepticus
Authors: Naylor David E. , Liu Hantao , Wasterlain Claude G.
Published: August 2005

During status epilepticus (SE), GABAergic mechanisms fail and seizures become self-sustaining and pharmacoresistant. During lithiumpilocarpine-induced SE, our studies of postsynaptic GABAAreceptors in dentate gyrus granule cells show a reduction in the amplitude of miniature IPSCs (mIPSCs). Anatomical studies show a reduction in the colocalization of the β2/β3 and γ2 subunits of GABAAreceptors with the presynaptic marker synaptophysin and an increase in the proportion of those subunits in the interior of dentate granule cells and other hippocampal neurons with SE. Unlike synaptic mIPSCs, the amplitude of extrasynaptic GABAAtonic currents is augmented during SE. Mathematical modeling suggests that the change of mIPSCs with SE reflects a decrease in the number of functional postsynaptic GABAAreceptors. It also suggests that increases in extracellular [GABA] during SE can account for the tonic current changes and can affect postsynaptic receptor kinetics with a loss of paired-pulse inhibition. GABA exposure mimics the effects of SE on mIPSC and tonic GABAAcurrent amplitudes in granule cells, consistent with the model predictions. These results provide a potential mechanism for the inhibitory loss that characterizes initiation of SE and for the pharmacoresistance to benzodiazepines, as a reduction of available functional GABAApostsynaptic receptors. Novel therapies for SE might be directed toward prevention or reversal of these losses.
Software-Entwicklung und Community-Kultivierung: ein integrativer Ansatz (Software-Development and Community-Cultivation: an Integrative Approach)
Authors: Jahnke Isa , Mattick Volker , Herrmann Thomas
Published: August 2005

Der Beitrag zeigt in einem integrativen Ansatz, welche technischen Entwicklungen zur sozialen Kultivierung einer Internet-unterstützten Community sinnvoll und notwendig sind. Anhand einer Fallstudie (Inpud-Community) wird einerseits die technische Entwicklung und andererseits die Bildung, Unterstützung und Förderung (Kultivierung) der sozialen Struktur beschrieben (soziotechnische Kultivierung). Wir möchten zeigen, dass klassische Software-Entwicklungs-Methoden für die Entwicklung von technischen Systemen zur Unterstützung der Community-Kultivierung durch die Berücksichtung von Lebensphasen-Modellen sinnvoll erweitert werden können. Dazu schlagen wir einen integrativen Ansatz vor, welcher die technische Entwicklung unter gleichzeitiger Berücksichtigung der Entwicklung des sozialen Systems unterstützt. Der Beitrag möchte damit eine Diskussion zur Vorgehensweise bei der Software-Entwicklung im Kontext einer soziotechnischen Community-Kultivierung anstoßen.
Organic Computing Methods for Face Recognition (Methoden des Organic Computing zur Gesichtserkennung)
Authors: Würtz Rolf P.
Published: August 2005

Summury

Automatic face recognition is a slowly maturing and economically highly important technology, which still falls short of the high expectations set on it. The variation in images taken from the same person makes face recognition systems difficult to design — it is impossible to explicitly code all variability. Successful systems have relied heavily on the principle of self-organizing many fragile cues to arrive at a robust decision and have been built by learning from biological systems. The paper describes the techniques of elastic bunch graph matching as a hierarchical integration of image pixels into Gabor responses, jets, graphs, and bunch graphs. Beside face recognition, these concepts are used for face classification learned from examples. It is attempted to develop them further to reach a complete parameterization of all faces. Methods for more general object recognition using the same Organic Computing principles are outlined and include the concept of end-stopped cells as corner detectors.
Datenverwaltung und Routing in allgemeinen Netzwerken (Data Management and Routing in General Networks)
Authors: Räcke Harald
Published: August 2005

Moderne Parallelrechnersysteme bestehen üblicherweise aus einer Vielzahl von Standardrechnern, die über ein relativ breitbandarmes und unstrukturiertes Netzwerk, wie z.B. das Internet, verbunden werden. Während dieser Ansatz im Prinzip eine hohe Parallelrechnerleistung zu vergleichsweise moderaten Kosten ermöglicht, stellt er auch neue Anforderungen an die Entwicklung von Algorithmen, da diese eine hohe Skalierbarkeit auch für sehr unstrukturierte Netzwerke aufweisen müssen. Diese Dissertation stellt beweisbar effiziente Routing- und Datenverwaltungsstrategien für beliebige Netzwerktopologien vor. Die behandelten Strategien erreichen eine hohe Skalierbarkeit, indem sie die Kommunikationslast gleichmäßig über alle Netzwerkressourcen verteilen, und dadurch das Kommunikationspotential des Netzwerks optimal ausnutzen.
Removal of cesium from alkaline waste solution: Part II – Column ion exchange study
Authors: Adu-Wusu Kofi , Hassan Neguib M. , Nash Charles A. , Marra James C.
Published: August 2005

Column ion exchange tests have been used to demonstrate the ability of SuperLig® 644 resin to remove 137Cs from highly alkaline radioactive waste. The column test resulted in 137Cs removal and overall decontamination factor of 99.6% (lead column) and 517000 (lag column) respectively. The concentration of 137Cs in the lag column effluent (0.000423 μCi 137Cs/mL) was two orders of magnitude below the low-activity waste vitrification limit of 0.087 μCi 137Cs/mL. The bed volume (BV=175) at the onset of breakthrough exceeded the requirement of 100 BV at 50% breakthrough. Cesium elution with 0.5 M HNO3 was adequate with a peak BV of 3.5. C/C
0=0.01 occurred at 10 BV of eluant, which is less than the target of 15 BV. Further, 99.99% of sorbed cesium was eluted from the resin. The residual 137Cs on the regenerated resin after the column operation was 23 μCi/g dry Na+ form resin.
The Effect of Antagonistic Pleiotropy on the Estimation of the Average Coefficient of Dominance of Deleterious Mutations
Authors: Fernández B , García-Dorado A , Caballero A
Published: August 2005

We investigate the impact of antagonistic pleiotropy on the most widely used methods of estimation of the average coefficient of dominance of deleterious mutations from segregating populations. A proportion of the deleterious mutations affecting a given studied fitness component are assumed to have an advantageous effect on another one, generating overdominance on global fitness. Using diffusion approximations and transition matrix methods, we obtain the distribution of gene frequencies for nonpleiotropic and pleiotropic mutations in populations at the mutation-selection-drift balance. From these distributions we build homozygous and heterozygous chromosomes and assess the behavior of the estimators of dominance. A very small number of deleterious mutations with antagonistic pleiotropy produces substantial increases on the estimate of the average degree of dominance of mutations affecting the fitness component under study. For example, estimates are increased three- to fivefold when 2% of segregating loci are overdominant for fitness. In contrast, strengthening pleiotropy, where pleiotropic effects are assumed to be also deleterious, has little effect on the estimates of the average degree of dominance, supporting previous results. The antagonistic pleiotropy model considered, applied under mutational parameters described in the literature, produces patterns for the distribution of chromosomal viabilities, levels of genetic variance, and homozygous mutation load generally consistent with those observed empirically for viability in Drosophila melanogaster.
Emergence of Species-Specific Transporters During Evolution of the Hemiascomycete Phylum
Authors: De Hertogh Benoît , Hancy Frédéric , Goffeau André , Baret Philippe V
Published: August 2005

We have traced the evolution patterns of 2480 transmembrane transporters from five complete genome sequences spanning the entire Hemiascomycete phylum: Saccharomyces cerevisiae, Candida glabrata, Kluyveromyces lactis, Debaryomyces hansenii, and Yarrowia lipolytica. The use of nonambiguous functional and phylogenetic criteria derived from the TCDB classification system has allowed the identification within the Hemiascomycete phylum of 97 small phylogenetic transporter subfamilies comprising a total of 355 transporters submitted to four distinct evolution patterns named “ubiquitous,” “species specific,” “phylum gains and losses,” or “homoplasic.” This analysis identifies the transporters that contribute to the emergence of species during the evolution of the Hemiascomycete phylum and may aid in establishing novel phylogenetic criteria for species classification.
Martensitic Phase Transformation of Isolated HfO2, ZrO2, and HfxZr1 – xO2 (0 < x < 1) Nanocrystals
Authors: Tang J. , Zhang F. , Zoogman P. , Fabbri J. , Chan S.‐W. , Zhu Y. , Brus L. E. , Steigerwald M. L.
Published: August 2005

We previously reported that, during the reactions to make nanocrystals of HfO2 and Hf‐rich HfxZr1 – xO2, a tetragonal‐to‐monoclinic phase transformation occurs that is accompanied by a shape change of the particles (faceted spherical to nanorods) when the temperature at which the reaction is conducted is changed from 340 to 400 °C. We now conclude that this concomitant phase and shape change is a result of the martensitic transformation of isolated nanocrystals in a hot liquid, where twinning plays a crucial role in accommodating the shape‐change‐induced strain. That such change was not observed during the reactions forming ZrO2 and Zr‐rich HfxZr1 – xO2 nanocrystals is attributed to the higher driving force needed in those instances compared to that needed for producing HfO2 and Hf‐rich HfxZr1 – xO2 nanocrystals. We also report here the post‐synthesis, heat‐induced phase transformation of HfxZr1 – xO2 (0 < x < 1) nanocrystals. As temperature increases, all the tetragonal nanocrystals transform to the monoclinic phase accompanied by an increase in particle size (as evidenced by X‐ray diffraction and transmission electron microscopy), which confirms that there is a critical size for the phase transformation to occur. When the monoclinic nanorods are heated above a certain temperature the grains grow considerably; under certain conditions a small amount of tetragonal phase appears.
Experimental approaches for understanding mixing performance of a minireactor
Authors: Chen G. G. , Luo G. S. , Li S. W. , Xu J. H. , Wang J. D.
Published: August 2005

Three experimental approaches are presented to determine the mixing characteristics of a new kind of high‐efficiency membrane dispersion minireactor in which microfiltration membranes are applied as the dispersion media. Residence time distribution (RTD) curves were measured for determining the macromixing characteristics. A typical Dushman reaction (iodide–iodate) coupled with a neutralization and precipitation reaction of BaSO4 were introduced to characterize the micromixing performance of a single‐phase mixing process. A dye extraction method was also applied to study the micromixing performance of a two‐liquid phase‐mixing system. The RTD result showed that the flow performance in the minireactor was almost in the plug flow condition. The micromixing performance was expressed with a segregation index, which could be <0.002. The single‐phase micromixing performance reached the desired level. The result of precipitation of BaSO4 showed that the mixing performance had a substantial influence on the particle size and size distribution. It was found that in the single‐phase mixing process the mixing performance was mainly influenced by the phase flux and the membrane pore size. With decreasing dispersed fluid flux or the membrane pore size, or with increasing continuous fluid flux, the micromixing performance was enhanced. The dye extraction method can correctly determine the mixing performance of a two‐liquid phase‐mixing system. Unlike the single‐phase mixing process, in the two‐liquid phase‐mixing process there was a minimum value for the mixing efficiency with the change of the continuous‐ or dispersed‐phase flux, when the membrane pore size was >0.9 μm. © 2005 American Institute of Chemical Engineers AIChE J, 2005
Note on disjoint blocking sets in Galois planes
Authors: Barát János , Marcugini Stefano , Pambianco Fernanda , Szőnyi Tamás
Published: August 2005

In this paper, we show that there are at leastcqdisjoint blocking sets in PG(2,q), wherec ≈ 1/3. The result also extends to some non‐Desarguesian planes of orderq. © 2005 Wiley Periodicals, Inc. J Combin Designs 14: 149–158, 2006
The use of tryptic marker‐peptides for the quantitative analysis of Cystatin C
Authors: Storme Michael L. , Sinnaeve Bart A. , Van Bocxlaer Jan F.
Published: August 2005

The use of marker‐peptides, measured by LC‐MS/MS, is investigated for the quantitative analysis of proteins. To that end, cystatin C is chosen as a model protein. It not only functions as a proof of concept protein but the growing interest in cystatin C as a new marker of kidney failure provides a practical application at the same time. The use of trypsin‐based proteolysis, to obtain so‐called marker‐peptides, simplifies the quantification of a protein to the quantification of a single or a number of peptides. Reproducibility of the trypsin proteolysis procedure is vital and has been optimised. A number of the marker‐peptides obtained are selected for LC‐MS(/MS) analysis. They are completely separated by high‐pressure LC allowing maximum selectivity and mass spectrometric multiple reaction monitoring sensitivity. By doing so, linear calibration curves can be obtained for cystatin C over two orders of magnitude. Experiments have been performed on a triple quadrupole mass spectrometer by single ion monitoring (maximum sensitivity) as well as by multiple reaction monitoring (maximum specificity).
MADIX Polymerization of Captodative Ethyl α‐Acetoxyacrylate with Acrylate Monomers
Authors: Batt‐Coutrot Delphine , Robin Jean‐Jacques , Bzducha Wojciech , Destarac Mathias
Published: August 2005

Summary: MADIX homopolymerization of a captodative monomer, ethyl‐α‐acetoxyacrylate (EAA) was investigated using AIBN as an initiator and O‐ethyl‐S‐(1‐methoxycarbonyl)ethyl dithiocarbonate as a transfer agent at 70 °C in a mixture of iPrOH and H2O. The experimental results revealed that this transfer agent had no effect on the polymerization reaction when compared with a free radical polymerization. Copolymerization of ethyl‐α‐acetoxyacrylate, with different acrylic monomers, such as butyl acrylate (BuA), acrylic acid, N,N‐(dimethylamino)ethyl acrylate and N,N‐dimethyl acrylamide, was then studied by MADIX polymerization using the same transfer agent. All the prepared copolymers were characterized by 1H NMR and size exclusion chromatography, and the obtained results were in accordance with theoretical predictions regarding molecular weight and copolymer composition. Futhermore, the living character of the polymerization has been checked by the chain extension of poly(EAA‐stat‐BuA) with vinyl acetate (Vac) which led to poly(EAA‐stat‐BuA)‐block‐poly(VAc).

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Phase Behaviour of New Side‐Chain Liquid Crystalline Polyoxetanes
Authors: Martínez‐Gómez Aránzazu , Bello Antonio , Pérez Ernesto
Published: August 2005

Summary: The synthesis and thermal behaviour of two new polyoxetanes with side chains having a dimer structure mesogen‐spacer‐mesogen and a long terminal alkyl group are reported. The two polymers differ in the chemical structure of the central spacer. The polyoxetanes have been obtained by cationic ring‐opening polymerisation of an appropriately substituted oxetane ring. Both polyoxetanes studied exhibit liquid crystalline properties showing a similar sequence of phases. DSC and synchrotron experiments indicate that a highly ordered phase with a probable orthorhombic packing is observed at low temperature. On heating, this phase melts into a mesophase with hexagonal order within the smectic layers, which, on further heating, is transformed into a disordered smectic mesophase.

Synchrotron X‐ray diffraction patterns of one of the poyoxetanes in a heating experiment.

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Synchrotron X‐ray diffraction patterns of one of the poyoxetanes in a heating experiment.
Molecular dynamics of star‐shaped poly(L‐lactide)s in tetrahydrofuran as solvent monitored by fluorescence spectroscopy
Authors: Danko Martin , Libiszowski Jan , Biela Tadeusz , Wolszczak Marian , Duda Andrzej
Published: August 2005

Linear telechelic, α,ω‐ditelechelic, and star‐shaped tri‐, tetra‐, penta‐, and hexa‐arm poly(L‐lactide)s (PLAs) fitted at every arm with pyrene end group have been prepared. Internal dynamics and mobility of the PLA chains in tetrahydrofuran solution at 25 °C, with regard to the number of PLA arms in one macromolecule and the individual arm average degree of polymerization, was followed by fluorescence spectroscopy. Analysis of both static and time‐resolved spectra of the star‐shaped polymers revealed dynamic segmental motion resulting in end‐to‐end cyclization, accompanied by an excimer formation. Probability and rate of the latter reaction increased with increasing number of arms and with decreasing their polymerization degree. Moreover, time‐resolved measurements revealed that for macromolecules containing few arms (2 or 3) the pyrene moieties are located in the interior of the star‐shaped PLAs, whereas in the instance of the higher number of arms (4–6) they are located at the periphery of the star‐shaped PLAs. Thus, increasing the number of arms leads to their stretching away from the center of the star‐shaped PLA macromolecule. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 4586–4599, 2005
Multiple Solutions for Blocking Probabilities in Asymmetric Networks
Authors: Dinwoodie Ian H. , Gamundi Emily , Mosteig Ed
Published: August 2005

Polynomial systems for blocking probabilities on networks with dynamic routing are formulated. Two parameters in the coefficient field representing link capacity are varied. A region of parameter values is identified on which the system has two solutions with a probabilistic interpretation. The region is bounded by contours of the constant term coefficients in the characteristic polynomials of certain traceform matrices. This generalizes earlier work on multiple blocking probabilities in symmetric networks.
Geometric constraints in semiclassical initial value representation calculations in Cartesian coordinates: Accurate reduction in zero-point energy
Authors: Issack Bilkiss B. , Roy Pierre-Nicholas
Published: August 2005

An approach for the inclusion of geometric constraints in semiclassical initial value representation calculations is introduced. An important aspect of the approach is that Cartesian coordinates are used throughout. We devised an algorithm for the constrained sampling of initial conditions through the use of multivariate Gaussian distribution based on a projected Hessian. We also propose an approach for the constrained evaluation of the so-called Herman-Kluk prefactor in its exact log-derivative form. Sample calculations are performed for free and constrained rare-gas trimers. The results show that the proposed approach provides an accurate evaluation of the reduction in zero-point energy. Exact basis set calculations are used to assess the accuracy of the semiclassical results. Since Cartesian coordinates are used, the approach is general and applicable to a variety of molecular and atomic systems.
Gas-phase models of γ turns: Effect of side-chain/backbone interactions investigated by IR/UV spectroscopy and quantum chemistry
Authors: Chin Wutharath , Piuzzi François , Dognon Jean-Pierre , Dimicoli Iliana , Mons Michel
Published: August 2005

The conformations of laser-desorbed jet-cooled short peptide chains Ac–Phe–Xxx–NH2 (Xxx=Gly, Ala, Val, and Pro) have been investigated by IR/UV double resonance spectroscopy and density-functional-theory (DFT) quantum chemistry calculations. Singly γ-folded backbone conformations (βL-γ) are systematically observed as the most stable conformers, showing that in these two-residue peptide chains, the local conformational preference of each residue is retained (βL for Phe and γ turn for Xxx). Besides, β turns are also spontaneously formed but appear as minor conformers. The theoretical analysis suggests negligible inter-residue interactions of the main conformers, which enables us to consider these species as good models of γ turns. In the case of valine, two similar types of γ turns, differing by the strength of their hydrogen bond, have been found both experimentally and theoretically. This observation provides evidence for a strong flexibility of the peptide chain, whose minimum-energy structures are controlled by side-chain/backbone interactions. The qualitative conformational difference between the present species and the reversed sequence Ac–Xxx–Phe–NH2 is also discussed.
Theoretical study of the lowest π→π* excitation energies for neutral and doped polyenes
Authors: Ma Haibo , Liu Chungen , Jiang Yuansheng
Published: August 2005

In earlier theoretical studies, it has been widely noticed that the electron correlation effect played an important role in determining the excitation energies of low-lying π→π* excited states for neutral polyenes and their radical cations and dications. In this paper, neutral and doped polyene oligomers of medium to large sizes are investigated with the Pariser-Parr-Pople model, and the π-electron correlation effect is fully taken into consideration by virtue of the density-matrix renormalization group method. The excitation properties in the polymer limit are also obtained by exponential extrapolation from the finite oligomers. The reasonable agreement of our results with the available experimental observations and advanced ab initio calculations is witnessed. It is also observed that while charge doping can significantly lower the exciting energy, the odd-charged oligomers show lower excitation energies than the even-charged ones.
Analysis of thermohydraulic explosion energetics
Authors: Büttner Ralf , Zimanowski Bernd , Mohrholz Chris-Oliver , Kümmel Reiner
Published: August 2005

Thermohydraulic explosion, caused by direct contact of hot liquids with cold water, represent a major danger of volcanism and in technical processes. Based on experimental observations and nonequilibrium thermodynamics we propose a model of heat transfer from the hot liquid to the water during the thermohydraulic fragmentation process. The model was validated using the experimentally observed thermal energy release. From a database of more than 1000 experimental runs, conducted during the last 20 years, a standardized entrapment experiment was defined, where a conversion of 1 MJ∕kg of thermal energy to kinetic energy within 700μs is observed. The results of the model calculations are in good agreement with this value. Furthermore, the model was found to be robust with respect to the material properties of the hot melt, which also is observed in experiments using different melt compositions. As the model parameters can be easily obtained from size and shape properties of the products of thermohydraulic explosions and from material properties of the hot melt, we believe that this method will not only allow a better analysis of volcanic eruptions or technical accidents, but also significantly improve the quality of hazard assessment and mitigation.
Antagonists of growth hormone-releasing hormone cross the blood-brain barrier: A potential applicability to treatment of brain tumors
Authors: Jaeger Laura B. , Banks William A. , Varga Jozsef L. , Schally Andrew V.
Published: August 2005

Hypothalamic growth hormone (GH)-releasing hormone (GHRH) stimulates the synthesis and release of GH from the pituitary gland. GHRH and its mRNA are also found in human cancers of the breast, ovary, prostate, lung, and other tumors, suggesting that GHRH is also a tumor growth factor. Various studies show that GHRH antagonists have antiproliferative effects in many tumor models; however, glioblastomas were examined only recently. Previous studies have demonstrated that s.c. administration of GHRH antagonist (JV-1-36) inhibited growth of s.c. U-87MG human glioblastomas and increased survival of nude mice with orthotopic implants of glioblastomas. Although treatment with JV-1-36 reduced tumorigenicity, it is not known whether peripherally administered GHRH antagonists can cross the blood-brain barrier. Brain endothelial cells joined by tight junctions form the blood-brain barrier, a “barrier” between the general circulation and the CNS. In this study, we administered a GHRH antagonist (JV-1-42) and showed that, after i.v. injection, iodinated JV-1-42 (
131
I-JV-1-42) enters the brain intact at a rate of 0.8514 μl/g per min with a serum half-life of 12.2 min. A one-site binding hyperbolic model indicated that the maximal percent of i.v. dose taken up per gram of brain was 0.41%. Coinjection of unlabeled JV-1-42 indicated that the transport from blood to brain is not saturable; however, transport from brain to blood is saturable and involves P-glycoprotein. Taken together, these results demonstrate that i.v.-administered
131
I-JV-1-42 readily crosses the blood-brain barrier and accumulates in the brain. This finding indicates that GHRH antagonists could provide a potential treatment for malignant glioblastomas.
RELAXANT EFFECT OF ADRENOMEDULLIN ON BOVINE ISOLATED IRIS SPHINCTER MUSCLE UNDER RESTING CONDITIONS
Authors: Uchikawa Y , Okano M , Sawada A , Asada Y , Kobayashi H , Wada A , Nao‐i N , Ohkura M , Tanaka N , Yamamoto R
Published: August 2005

1. The mechanisms involved in the fine adjustment of iris sphincter muscle tone are largely unknown. The aim of the present study was to clarify the effects of adrenomedullin on the resting tension of the bovine isolated iris sphincter muscle.

2. The motor activity of the bovine isolated iris sphincter muscle was measured isometrically. The effects of adrenomedullin on resting tension were analysed in the presence of indomethacin. The presence of adrenomedullin mRNA in the preparation was determined by reverse transcription–polymerase chain reaction. Immunolabelling for adrenomedullin was also performed.

3. Adrenomedullin significantly decreased the resting tension of the muscle. The relaxant effect of adrenomedullin was significantly inhibited by adrenomedullin (22–52), a putative antagonist for the adrenomedullin receptor, or calcitonin gene‐related peptide (CGRP) (8–37), a putative antagonist for the CGRP1 receptor. The relaxant effect was almost completely blocked by a combination of adrenomedullin (22–52) and CGRP (8–37).

4. The relaxant effect of adrenomedullin was also significantly diminished by 2′,5′‐dideoxyadenosine, an inhibitor of adenylate cyclase, NG‐nitro‐l‐arginine, an inhibitor of nitric oxide synthesis, or 1H‐[1,2,4]oxadiazolo[4,3‐a]quinoxalin‐1‐one, an inhibitor of soluble guanylate cyclase.

5. Reverse transcription–polymerase chain reaction analysis showed that adrenomedullin mRNA was expressed in the muscle strip. Immunopositive staining for adrenomedullin was detected in blood vessel cells and in the iris sphincter muscle cells.

6. These results suggest that adrenomedullin may be an autocrine and paracrine regulator of the resting tension of the iris sphincter muscle. Its biological effects may be due to the direct involvement of adrenomedullin receptors and also to the stimulation of CGRP1 receptors. The stimulation of these receptors by the peptide leads to the activation of adenylate cyclase and soluble guanylate cyclase and subsequent relaxation of the muscle strip.
Intracellular Localization and Biochemical Function of Variant β‐Actin, which Inhibits Metastasis of B16 Melanoma
Authors: Sadano Hiroyuki , Shimokawa‐Kuroki Rie , Taniguchi Shun'ichiro
Published: August 2005

We analyzed the biochemical nature of βm‐actin protein found in mouse B16 melanoma. When we carried out immunostaining with the antibody specific to βm‐actin, filamentous immunofluorescence was observed in B16‐F1, a low‐metastatic cell line expressing βm‐actin, but not in highly metastatic B16‐F10 that did not express βm‐actin. When a purified actin fraction containing βm‐actin was polymerized and immunoprecipitated with anti‐βm‐actin antibody, the immunoprecipitate contained βm‐, β‐ and γ‐actin. This indicated that the βm‐actin was incorporated into an actin filament together with β‐ and γ‐actin in vitro, and this phenomenon was consistently suggested by cellular double immunostaining with anti‐βm‐actin and common anti‐actin antibody. When the actin fraction containing βm‐actin under a regular depolymerizing condition was subjected to immuno‐adsorption assay using anti‐βm antibody and protein‐A Sepharose, the immunoadsorbed aggregates contained βm‐, β‐and γ‐actin. This indicates that the actin fraction was not completely depolymerized and contained βm‐actin‐containing oligomers, which were too small to be precipitated with anti‐βm‐actin antibody alone. The incomplete depolymerization of the βm‐actin‐containing fraction was also suggested by the much lower DNase 1 inhibition activity of the βm‐actin‐containing fraction than that of β‐ and γ‐actin fraction. Furthermore, a DNase 1 binding assay showed that cytoplasmic supernatant prepared from B16‐F1 under a low‐ionic condition contained less monomeric actin than the cytoplasmic preparation from B16‐F10. These results suggested that βm‐actin protein in B16 melanoma probably inhibits the dynamic conversion between the monomeric and polymerized forms of actin, leading to a decrease in cell motility and consequently the suppression of invasiveness and metastasis.
Antitumor Effect of Intratumoral Administration of Biological Response Modifiers: Induction of Immunosuppressive Acidic Protein, a Type of α1‐Acid Glycoprotein, in Mice
Authors: Ebina Takusaburo , Murata Kazuko , Tamura Keiji
Published: August 2005

The antitumor effects of biological response modifiers (BRMs) in an experimental mouse model, the “double grafted tumor system” were analyzed. Male BALB/c mice received simultaneous inoculations of Metn‐A fibrosarcoma cells on the right flank (106 cells) and left flank (2 × 105 cells) on day 0, and BRMs were injected intratumorally into the right tumor on days 3, 4 and 5. PSK (a protein‐bound polysaccharide preparation), interleuldn‐1 (IL‐1) and cepharanthin (R) cured not only the right, but also the left, non‐treated tumor in a double grafted tumor system. OK‐432 (a Streptococcus preparation) and BCG and tumor necrosis factor (TNF) cured the right tumor and inhibited the growth of the left tumor. Lentinan (a polysaccharide preparation) and IL‐6 inhibited neither the right nor the left tumor. Immunosuppressive acidic protein (IAP) in serum was increased transiently soon after intradermal injection of PSK, CR, OK‐432 and TNF in BALB/c mice. Lentinan, however, did not induce IAP. IAP in serum was gradually increased after intradermal inoculation of Meth‐A tumor in BALB/c mice. The biochemical difference between PSK‐induced IAP (early, inflammatory IAP) and Meth‐A‐induced IAP (late, tumor‐induced IAP) was investigated by crossed affinity immunoelectrophoresis with concanavalin A. IAP of murine serum was separated into 4 peaks. IAP in normal mouse was rich in high‐mannose type sugar chain (Peak 3) and contained no hybrid‐type sugar chain (Peak 4), which was present in inflammatory and tumor‐induced IAP. Inflammatory IAP was rich in biantennary sugar chain (Peak 2) and tumor‐induced IAP was rich in tri‐tetraantennary sugar chain (Peak 1).
Virus Isolate‐specific Antibodies against Hypervariable Region 1 of the Hepatitis C Virus Second Envelope Protein, gp70
Authors: Kato Nobuyuki , Nakazawa Takahide , Ootsuyama Yuko , Sugiyama Kazuo , Ohkoshi Showgo , Shimotohno Kunitada
Published: August 2005

Hypervariable region 1 (HVR1), located in the N‐terminal region of a putative second envelope glycoprotein (gp70) of hepatitis C virus (HCV), contains immunological B‐cell epitopes which might be neutralizing epitopes. To clarify whether B‐cell epitopes within HVR1 are common among virus isolates or specific for the homologous virus isolate, we examined the reactivities of sera from 53 patients with chronic hepatitis or hepatocellular carcinoma/liver cirrhosis against two different HVR1 peptides (HVR11‐1 and HVR1 Y‐l) derived from patient I with sporadic acute hepatitis and an asymptomatic carrier Y, respectively, using our original assay system for the detection of anti‐HVR1 antibody. All patients examined had a history of blood transfusion. Most sera showed no reactivity with either HVR1 1‐1 or HVR1 Y‐l peptide. Only seven and fourteen serum samples reacted significantly, although weakly, with HVR1 1‐1 and HVR1 Y‐l peptides, respectively, compared with the serum from patient I or asymptomatic carrier Y. The blood transfusions of most reactive cases had occurred more than thirty years earlier. Six cases reacted with both HVR1 1‐1 and HVR1 Y‐l peptides, but further analysis revealed that only three cases reacted weakly with the peptide for either epitope I or II, identified within HVR11‐1, These results indicate that the B‐cell epitopes within HVR1 are fairly specific for the homologous virus isolate, and this may represent a serious difficulty in the development of a vaccine against HCV.
Suppression of Gl Arrest and Enhancement of G2 Arrest by Inhibitors of Poly(ADP‐ribose) Polymerase: Possible Involvement of Poly(ADP‐ribosyl)ation in Cell Cycle Arrest Following γ‐Irradiation
Authors: Nozaki Tadashige , Masutani Mitsuko , Akagawa Tetsuya , Sugimura Takashi , Esumi Hiroyasu
Published: August 2005

Low‐dose γ‐irradiation of mouse embryonic fibroblast C3D2F1 3T3‐a cells caused Gl arrest along with G2 arrest and inhibition of replicative DNA synthesis. When the cells were cultured in the presence of inhibitors of poly(ADP‐ribose) polymerase [EC 2.4.2.30], such as 3‐aminobenzamide, benzamide and luminol, Gl arrest of C3D2F1 3T3‐a cells was suppressed and enhancement of G2 arrest was observed. In contrast, 3‐aminobenzoic acid, a non‐inhibitory analog of 3‐aminobenzamide, did not suppress Gl arrest following γ‐irradiation. These results suggest that the poly(ADP‐ribosyDation reaction is critical for the pathway of Gl arrest and is also involved in the pathway of G2 arrest.
Alteration of the p53 Tumor Suppressor Gene Occurs Independently of K‐ras Activation and More Frequently in Serous Adenocarcinomas than in Other Common Epithelial Tumors of the Human Ovary
Authors: Fujita Masami , Enomoto Takayuki , Inoue Masaki , Tanizawa Osamu , Ozaki Masami , Rice Jerry M. , Nomura Taisei
Published: August 2005

To clarify the role of the p53 tumor suppressor gene in the development of human ovarian epithelial tumors and to study the association of p53 alterations with K‐ras activation, a series of 70 common epithelial ovarian tumors from Japanese patients was studied. These included 31 serous adenocarcinomas, 12 mucinous adenocarcinomas, 5 mutinous tumors of borderline malignancy, 13 endometrioid adenocarcinomas, and 9 clear cell carcinomas. Allelic loss, recognized at the polymorphic site in codon 72 of the p53 gene, was detected in 14 of 36 (39%) informative cases by restriction fragment length polymorphism analysis and by single‐strand conformation polymorphism (SSCP) analysis of polymerase chain reaction(PCR)‐amplified DNA fragments. Mutations in the highly conserved regions of the p53 gene were detected by SSCP analysis of PCR‐amplifled fragments. Mutations were found in 22 of 70 (31%) ovarian tumors, including 1 of 5 mucinous tumors of borderline malignancy. Mutations were subsequently characterized by direct sequencing. Single missense base substitutions were detected in 13 ovarian carcinomas and in one case of mucinous tumor of borderline malignancy. Short (1‐8 bp) deletions and insertions were found in 8 cases. Mutations in the p53 gene occurred more frequently in serous adenocarcinomas (14/31, 45%) than in all nonserous types of malignant epithelial tumors combined (7/34, 21%;P=0.032). Point mutations in K‐ras were identified by dot blot hybridization analysis of PCR‐amplified fragments with mutation‐specific oligonucleotides and by direct sequencing. The overall frequency of K‐ras mutations was 19/70 (27%).K‐ras mutations were found in 12 of 17 (71%) mucinous tumors (8/12 mucinous carcinomas [67%] and 4/5 mucinous tumors of borderline malignancy [80%]), and occurred more frequently than in serous carcinomas (4/31, 13%;P=0.00009) or in all nonmucinous types of ovarian epithelial tumors combined (7/53, 13%; p=0.00002). These data suggest that different combinations of oncogenes and/or tumor suppressor genes may be involved in the genesis and development of histologically distinct categories of common epithelial tumors of the human ovary.
Expression of Tumor‐associated Glycoantigen, Sialyl Lewisa, in Human Head and Neck Squamous Cell Carcinoma and Its Application to Tumor Immunotherapy
Authors: Makino Koji , Ogata Tetsuro , Miyake Hirosato , Habu Sonoko , Nishimura Takashi
Published: August 2005

The glycoantigen sialyl Lewisa(sLea) is widely expressed on a variety of gastrointestinal tumor cells. Here, we immunohistochemically demonstrated the expression of sLeaantigen in 54% (7 out of 13) of human head and neck squamous cell carcinoma (H‐NSCG) samples. Frequent expression of sLeaantigen was also demonstrated on a variety of H‐NSCC cell lines using flow cytometry. Both CD4+and CD8+T cells, which were activated with immobilized OKT3 monoclonal antibody plus inter‐leukin‐2, showed augmented cytotoxicity against sLea‐positive H‐NSCC, including autologous tumor cells, on targeting with anti‐CD3 x anti‐sLeabispccific antibody, suggesting that sLeaantigen is a good target molecule for bispecific antibody‐dependent adoptive tumor immunotherapy of human head and neck cancer.
Characterization of Matrix‐degrading Proteinases and Their Inhibitors Secreted by Human Gynecological Carcinoma Cells
Authors: Miyagi Etsuko , Yasumitsu Hidetaro , Hirahara Fumiki , Minaguchi Hiroshi , Koshikawa Naohiko , Miyazaki Kaoru , Umeda Makoto
Published: August 2005

Matrix‐degrading proteinases secreted by tumor cells play crucial roles in tumor cell invasion and metastasis. Serum‐free conditioned media of 7 human gynecological carcinoma cell lines were examined for proteinases and their inhibitors by using gelatin zymography, reverse zymograpby and immunoblotting. All of three ovarian adenocarcinoma cell lines secreted urokinase‐type plasminogen activator. Among them, a mucinous cystadenocarcinoma cell line also secreted tissue‐type plasminogen activator, plasmin‐like enzyme and trypsinogen. On the other hand, two ovarian undifferentiated carcinoma cell lines mainly secreted gelatinase A or B. A choriocarcinoma cell line secreted multiple metalloproteinases in the highest amount, whereas an endometrial adenocarcinoma cell line (HEC‐1) derived from an early clinical stage hardly secreted any gelatinolytic enzyme. The five high proteinases producers hardly secreted the corresponding inhibitors, such as tissue inhibitor of metalloproteinases (TIMP)‐1,‐2 or plasminogen activator inhibitor‐1. In contrast to these highly malignant cell lines, a poor proteinase producer, HEC‐1, secreted a large amount of TIMPs. Therefore, an enhanced proteolytic tendency appears to be associated with gynecological cancer cells established from highly malignant tumors.
Expression of MAGE‐1 Gene by Esophageal Carcinomas
Authors: Toh Yuji , Yamana Hideaki , Shichijo Shigeki , Fujita Hiromasa , Tou Uhi , Sakaguchi Minako , Kakegawa Teruo , Itoh Kyogo
Published: August 2005

Expression of the MAGE genes encoding tumor‐rejection antigens on HLA‐A1 and ‐Cwl601 recognized by cytotoxic T lymphocytes was investigated in esophageal carcinomas at the mRNA level by the semiquantitative reverse transcription‐polymerase chain reaction method. MAGE‐1 and ‐2 genes, but not MAGE‐3, ‐3/‐6 and ‐4a/‐4b genes, were expressed in substantial proportions of the primary esophageal carcinomas and their metastatic lymph nodes. The proportion of MAGE‐positive samples in the primary esophageal carcinomas correlated with the T factor of the TNM classification (pT1: 2 of 12 tumors, pT2: 1 of 6, pT3: 12 of 29, and pT4: 7 of 18). These results have important implications for specific immunotherapy of esophageal carcinomas using MAGE‐1 gene product.
Inhibition of UDP‐glucuronosyltransferase by Aglycons of Natural Glucuronides in Kampo Medicines Using SN‐38 as a Substrate
Authors: Yokoi Tsuyoshi , Narita Mikako , Nagai Eiichi , Hagiwara Hisao , Aburada Masaki , Kamataki Tetsuya
Published: August 2005

7‐Ethyl‐10‐[4‐(piperidino)‐1‐piperidino]carbonyloxycamptothecin (CPT‐11), a potent anticancer agent for lung and gynecological cancers, is metabolized in vivo to the active compound, 7‐ethyI‐10‐hydroxycamptothecin (SN‐38), which is subsequently conjugated to SN‐38‐glucuronide by UDP‐glucuronosyltransferase (UDP‐GT). Three purified aglycons of natural glucuronides, baicalein, luteolin and glycyrrhetic acid, inhibited UDP‐GT activity towards SN‐38 as a substrate. The inhibitory potencies of these aglycons toward UDP‐GT were similar to that of 1‐naphthol. Based on these results, together with our previous finding that the corresponding glucuronides used in the present study strongly inhibited β‐glucuronidase in gut flora, we propose that materials in Kampo (Japanese herbal) medicines containing these aglycons of natural glucuronides could he used in vivo to decrease the enterohepatic circulation of SN‐38 and other drugs.
Comparison of Incorporation and Extension of Nucleotides in vitro opposite 8‐Hydroxyguanine (7,8‐Dihydro‐8‐oxoguanine) in Hot Spots of the c‐Ha‐ras Gene
Authors: Kamiya Hiroyuki , Murata‐Kamiya Naoko , Fujimuro Masahiro , Kido Kaori , Inoue Hideo , Nishimura Susumu , Masutani Chikahide , Hanaoka Fumio , Ohtsuka Eiko
Published: August 2005

DNA templates with 8‐hydroxyguanine (7,8‐dihydro‐8‐oxoguanine, oh8Gua) at a site corresponding to the first or second position of codon 12 of the c‐Ha‐ras gene were prepared, and the nucleotides inserted opposite the modified base were compared. The Klenow fragment (KF) of Escherichia coli DNA polymerase I inserted C opposite oh8Gua at both positions. Taq DNA polymerase incorporated C and A opposite oh8Gua, and the ratio of C to A was higher at the first position than at the second position. DNA polymerase α (pol α) inserted A and C at the first position, and A at the second position of codon 12, indicating that the ratio of C to A was higher at the first position. Moreover, we studied the extensions of bases paired with oh8Gua by DNA polymerases with or without 3′‐5’exonuclease activity. G and T opposite oh8Gua were removed, and subsequently C was inserted by KF. We found that an oh8Gua:A pair was recognized by the exonuclease activity of the enzyme and that A was partially subsituted by C. On the other hand, pol α extended only C and A opposite oh8Gua. No difference was observed with oh8Gua at the two positions. These results indicate that the ratio of nucleotides incorporated opposite oh8Gua depends on the sequence context, while there is no particular difference in the extension of base pairs involving oh8Gua by DNA polymerases.
Relationship between the Pharmacokinetics of Irinotecan and Diarrhea during Combination Chemotherapy with Cisplatin
Authors: Kudoh Shinzoh , Fukuoka Masahiro , Masuda Noriyuki , Yoshikawa Atsuko , Kusunoki Yoko , Matsui Kaoru , Negoro Shun‐ichi , Takifuji Nobuhide , Nakagawa Kazuhiko , Hirashima Tomonori , Yana Takashi , Takada Minoru
Published: August 2005

Two phase I trials of irinotecan (CPT‐11) in combination with cisplatin were conducted. In both cases, the dose‐limiting toxicities were leukopenia and/or diarrhea. During these trials the pharmacokinetics of CPT‐11 and its active metabolite, 7‐ethyl‐10‐hydroxycamptothecin (SN‐38), were investigated to evaluate the relationship between pharmacokinetic parameters and diarrhea, since this is an unpredictable and severe toxicity of combination chemotherapy using CPT‐11 and cisplatin. Twenty‐three previously untreated patients with advanced lung cancer were evaluated in the pharmacokinetic study. Ten patients received CPT‐11 at 80 or 90 mg/m2 plus cisplatin at 60 mg/m2. The other 13 patients received CPT‐11 at 80 or 90 mg/m2 plus cisplatin at 80 mg/m2 with the granulocyte colony‐stimulating factor support (2 μg/kg × 16 days). CPT‐11 was given as a 90‐min intravenous infusion on days 1, 8, and 15. Cisplatin was given on day 1. The pharmacokinetics of CPT‐11 and SN‐38 were analyzed on day 8 during the first course of treatment. The maximum tolerated dose of CPT‐11 was 90 mg/m2 in both phase I trials. The severity of diarrhea was best correlated with the peak plasma concentration of SN‐38 among the pharmacokinetic parameters tested. In addition, patients with a plasma SN‐38 level > 12.4 ng/ml at 1.75 h after the start of CPT‐11 infusion had a higher incidence of Eastern Cooperative Oncology Group grade 3–4 diarrhea than those with a lower SN‐38 level (P=0.0003). Stepwise logistic regression analysis identified the SN‐38 concentration as a significant contributor to the development of diarrhea (P=0.0021). We conclude that there is a clear relationship between the SN‐38 concentration and diarrhea during chemotherapy with CPT‐11 plus cisplatin.