bluuebunny/crossref_metadata_2025_split huggingface dataset:
Hypotonic stress activates BK channels in clonal kidney cells via purinergic receptors, presumably of the P2Y1subtype
Authors: Hafting T. , Haug T. M. , Ellefsen S. , Sand O. 
Published: July 2006

AbstractAim: Membrane stretch due to cell swelling may cause a minute leakage of adenosine triphosphate (ATP) that stimulates endogenous purinergic receptors. The following elevation of the cytosolic‐free Ca2+concentration ([Ca2+]i) may then participate in cell volume regulation. The aim of the present study was to test if purinergic receptors and large conductance Ca2+activated K+(BK) channels are activated in response to hypotonic stress in clonal kidney cells (Vero cells).Methods: The methods used are fura‐2 microfluorometry, cell‐attached patch clamp and reverse‐transcriptase polymerase chain reaction (RT‐PCR).Results: Subjecting cells to hypotonic stress for 10 s by exposure to a solution with 45% reduced osmolality induced a transient rise in [Ca2+]i. This response persisted in virtually Ca2+‐free extracellular solution, demonstrating that Ca2+was mainly released from intracellular stores. The hypotonically induced elevation of [Ca2+]iwas completely inhibited by the P2 receptor antagonists suramine (100 μm) and pyridoxalphosphate‐6‐azophenyl‐2′4′‐disulphonate (PPADS; 20 μm), indicating that extracellular ATP is crucial for the [Ca2+]iincrease. RT‐PCR revealed the expression of mRNA for P2Y1receptors in Vero cells. The putatively selective P2Y1antagonist PPADS did completely block Ca2+responses to both ATP and hypotonic stress, suggesting that P2Y1receptors are mediating the response. Furthermore, patch clamp recordings in cell‐attached configuration revealed that BK channels are activated in response to hypotonic stress.Conclusion: Vero cells express functional purinergic receptors, presumably of the P2Y1subtype. These receptors are responsible for the elevation of [Ca2+]ievoked by hypotonic stress. The concurrent activation of BK channels permits K+efflux that may contribute to regulatory volume decrease.
Specific incremental field test for aerobic fitness in tennis
Authors: Girard O , Chevalier R , Leveque F , Micallef J P , Millet G P 
Published: July 2006

Objectives:To compare metabolic and cardiorespiratory responses between subjects undergoing incremental treadmill (non-specific) and tennis field based (sport specific) tests.Methods:Nine junior competitive tennis players randomly performed two incremental protocols to exhaustion: a treadmill test (TT) and a tennis specific fitness test (FT). The FT consisted of repeated displacements replicating the game of tennis at increasing speed on a court. In both tests, ventilatory variables and heart rate (HR) were determined at the ventilatory threshold (VT), respiratory compensation point (RCP), and maximal loads (max). Blood lactate concentration was determined at the point of volitional fatigue.Results:Percentage (mean (SD)) maximal HR (83.6 (5.1)v83.0 (2.8) and 92.1 (2.1)v92.3 (2.1)%, respectively) and percentage maximal oxygen uptake (VO2max) (69.4 (8.1)v73.5 (6.1) and 84.4 (6.5)v85.5 (8.7)%, respectively) at the VT and RCP were not different between the FT and TT subjects, whereas VO2maxwas higher in the FT than in the TT (63.8 (3.0)v58.9 (5.3) ml/min/kg; p<0.05). Blood lactate concentration (10.7 (3.0)v10.6 (4.3) mmol/l) did not differ between the TT and FT.Conclusions:Although cardiorespiratory variables were not different at submaximal intensities between the two tests, VO2maxvalues derived from laboratory measurements were underestimated. Using field testing in addition to treadmill testing provides a better measurement of a player’s individual fitness level and may be routinely used to accurately prescribe appropriate aerobic exercise training.
Circulating Tumor Cells at Each Follow-up Time Point during Therapy of Metastatic Breast Cancer Patients Predict Progression-Free and Overall Survival
Authors: Hayes Daniel F. , Cristofanilli Massimo , Budd G. Thomas , Ellis Matthew J. , Stopeck Alison , Miller M. Craig , Matera Jeri , Allard W. Jeffrey , Doyle Gerald V. , Terstappen Leon W.W.M. 
Published: July 2006

Abstract
Purpose: We reported previously that ≥5 circulating tumor cells (CTC) in 7.5 mL blood at baseline and at first follow-up in 177 patients with metastatic breast cancer (MBC) were associated with poor clinical outcome. In this study, additional follow-up data and CTC levels at subsequent follow-up visits were evaluated.
Experimental Design: CTCs were enumerated in 177 MBC patients before the initiation of a new course of therapy (baseline) and 3 to 5, 6 to 8, 9 to 14, and 15 to 20 weeks after the initiation of therapy. Progression-free survival (PFS) and overall survival (OS) times were calculated from the dates of each follow-up blood draw. Kaplan-Meier plots and survival analyses were done using a threshold of ≥5 CTCs/7.5 mL at each blood draw.
Results: Median PFS times for patients with &lt;5 CTC from each of the five blood draw time points were 7.0, 6.1, 5.6, 7.0, and 6.0 months, respectively. For patients with ≥5 CTC, median PFS from these same time points was significantly shorter: 2.7, 1.3, 1.4, 3.0, and 3.6 months, respectively. Median OS for patients with &lt;5 CTC from the five blood draw time points was all &gt;18.5 months. For patients with ≥5 CTC, median OS from these same time points was significantly shorter: 10.9, 6.3, 6.3, 6.6, and 6.7 months, respectively. Median PFS and OS times at baseline and up to 9 to 14 weeks after the initiation of therapy were statistically significantly different.
Conclusions: Detection of elevated CTCs at any time during therapy is an accurate indication of subsequent rapid disease progression and mortality for MBC patients.
Mouse Models of Lung Cancer
Authors: Dutt Amit , Wong Kwok-Kin 
Published: July 2006

Abstract
Human lung cancer is responsible for ∼30% of all cancer deaths worldwide with &gt;160,000 deaths in the United States alone annually. Recent advances in the identification of novel mutations relevant to lung cancer from a myriad of genomic studies might translate into meaningful diagnostic and therapeutic progress. Towards this end, a genetic model animal system that can validate the oncogenic roles of these mutations in vivo would facilitate the understanding of the pathogenesis of lung cancer as well as provide ideal preclinical models for targeted therapy testing. The mouse is a promising model system, as complex human genetic traits causal to lung cancer, from inherited polymorphisms to somatic mutations, can be recapitulated in its genome via genetic manipulation. We present here a brief overview of the existing mouse models of lung cancers and the challenges and opportunities for building the next generation of lung cancer mouse models.
Novel Combinations Based on Epidermal Growth Factor Receptor Inhibition
Authors: Adjei Alex A. 
Published: July 2006

Abstract
In spite of recent advances in molecular biology leading to the introduction of clinically active novel agents, such as imatinib, erlotinib, and bevacizumab, therapy of the most common epithelial tumors, such as lung cancer, remains unsuccessful. The diversity of molecular abnormalities in these tumors is felt to partly contribute to their resistance to therapy. It is, therefore, widely accepted that one approach to improving the efficacy of cancer therapy is the development of rational, hypothesis-based combinations of anticancer agents that may exhibit synergistic cytotoxic interactions. A number of empirical combination studies with the epidermal growth factor receptor and classic cytotoxic agents were undertaken in clinical trials, with disappointing results. It is, therefore, felt that preclinical combinations of epidermal growth factor receptor inhibitors and other novel agents, based on sound knowledge of complementary signaling pathways whose concerted inhibition would be hypothesized to inhibit growth, is the reasonable approach in the future. A brief overview of some of these pathways (mammalian target of rapamycin, vascular endothelial growth factor receptor, and ras/mitogen-activated protein kinase signaling) is provided in this review.
A combined approach to data mining of textual and structured data to identify cancer-related targets
Authors: Pospisil Pavel , Iyer Lakshmanan K , Adelstein S James , Kassis Amin I 
Published: July 2006

Abstract

Background
We present an effective, rapid, systematic data mining approach for identifying genes or proteins related to a particular interest. A selected combination of programs exploring PubMed abstracts, universal gene/protein databases (UniProt, InterPro, NCBI Entrez), and state-of-the-art pathway knowledge bases (LSGraph and Ingenuity Pathway Analysis) was assembled to distinguish enzymes with hydrolytic activities that are expressed in the extracellular space of cancer cells. Proteins were identified with respect to six types of cancer occurring in the prostate, breast, lung, colon, ovary, and pancreas.

Results
The data mining method identified previously undetected targets. Our combined strategy applied to each cancer type identified a minimum of 375 proteins expressed within the extracellular space and/or attached to the plasma membrane. The method led to the recognition of human cancer-related hydrolases (on average, ~35 per cancer type), among which were prostatic acid phosphatase, prostate-specific antigen, and sulfatase 1.

Conclusion
The combined data mining of several databases overcame many of the limitations of querying a single database and enabled the facile identification of gene products. In the case of cancer-related targets, it produced a list of putative extracellular, hydrolytic enzymes that merit additional study as candidates for cancer radioimaging and radiotherapy. The proposed data mining strategy is of a general nature and can be applied to other biological databases for understanding biological functions and diseases.
Expression of mammalian GPCRs in C. elegansgenerates novel behavioural responses to human ligands
Authors: Teng Michelle S , Dekkers Martijn PJ , Ng Bee Ling , Rademakers Suzanne , Jansen Gert , Fraser Andrew G , McCafferty John 
Published: July 2006

AbstractBackgroundG-protein-coupled receptors (GPCRs) play a crucial role in many biological processes and represent a major class of drug targets. However, purification of GPCRs for biochemical study is difficult and current methods of studying receptor-ligand interactions involvein vitrosystems.Caenorhabditis elegansis a soil-dwelling, bacteria-feeding nematode that uses GPCRs expressed in chemosensory neurons to detect bacteria and environmental compounds, making this an ideal system for studyingin vivoGPCR-ligand interactions. We sought to test this by functionally expressing two medically important mammalian GPCRs, somatostatin receptor 2 (Sstr2) and chemokine receptor 5 (CCR5) in the gustatory neurons ofC. elegans.ResultsExpression of Sstr2 and CCR5 in gustatory neurons allowC. elegansto specifically detect and respond to somatostatin and MIP-1α respectively in a robust avoidance assay. We demonstrate that mammalian heterologous GPCRs can signal via different endogenous Gαsubunits inC. elegans, depending on which cells it is expressed in. Furthermore, pre-exposure of GPCR transgenic animals to its ligand leads to receptor desensitisation and behavioural adaptation to subsequent ligand exposure, providing further evidence of integration of the mammalian GPCRs into theC. eleganssensory signalling machinery. In structure-function studies using a panel of somatostatin-14 analogues, we identified key residues involved in the interaction of somatostatin-14 with Sstr2.ConclusionOur results illustrate a remarkable evolutionary plasticity in interactions between mammalian GPCRs andC. eleganssignalling machinery, spanning 800 million years of evolution. Thisin vivosystem, which imparts novel avoidance behaviour onC. elegans, thus provides a simple means of studying and screening interaction of GPCRs with extracellular agonists, antagonists and intracellular binding partners.
Short-term energy regulation of whitebellied sunbirds (Nectarinia talatala): effects of food concentration on feeding frequency and duration
Authors: Köhler A. , Verburgt L. , Nicolson S. W. 
Published: July 2006

SUMMARY
Avian nectarivores show compensatory feeding by adjusting their volumetric intake in response to variation in nectar concentration. This study used an infrared photo-detection system to investigate the short-term feeding patterns of whitebellied sunbirds (Nectarinia talatala) consuming three different sucrose concentrations (10, 20 and 30% w/w). Sunbirds increased their feeding frequency on the most dilute diet, but there was no change in feeding duration. Thus, the increase in total time spent feeding on the dilute diet was due to the increased feeding frequency. No difference in short-term feeding patterns was found between the 20% and 30% diets. Total time spent feeding was extremely short on all diets (96-144 s in every hour). Birds maintained the same steady increase in body mass over the course of the day on all three diets. Daily rhythms in feeding patterns were evident, with longer feeding duration and lower feeding frequency in the early morning and evening than during the rest of the day. Because ingestion rates on a particular diet may vary through the day, caution must be exercised in using feeding duration as a surrogate for meal size. Individual birds varied greatly in their feeding patterns irrespective of diet concentration.
The Heats of Dilution in Atactic Polymethyl Methacrylate Solutions
Authors: Kagemoto Akihiro , Murakami Sachio , Fujishiro Ryoichi 
Published: July 2006

Abstract
In order to ascertain the dependence of the interaction parameter, χH, between the polymer and the solvent molecules on the polymer concentration, the heats of dilution in an atactic polymethyl methacrylate solution have been measured for the polymers with the degrees of polymerization of 3000 and 7800. It was found that the values of χH obtained are dependent on the concentration in all the solvents used, as in the solutions of polystyrene and polybutadiene reported as in previous papers. χH depends also on the molecular weight, this is in agreement with the suggestion by Huggins (J. Am. Chem. Soc., 86, 3535 (1964)).
A Spectrophotometric Study on the Thorium Complex of o-Carboxyphenyl-azo-chromotropic Acid
Authors: Tôei Kyoji , Miyata Haruo , Harada Takuji 
Published: July 2006

Abstract
o-Carboxyphenyl-azo-chromotropic acid was synthesized as a colorimetric reagent for thorium. The acid dissociation constants of the reagent have been determined spectrophotometrically at 25°C and μ=0.1 (NaClO4). The pK1 (for the dissociation of the carboxyl group) and the pK2 (for the dissociation of the naphtholic hydroxyl groups) were 3.20 and 10.17 respectively. The reagent forms a violet 1 : 1 complex with thorium, showing an absorption maximum at 565 mμ in an acidic solution. The apparent stability constant of the thorium complex was measured spectrophotometrically.
The Syntheses of Benzofuran-carboxylic Acids and the Acetylation of Their Esters
Authors: Kawase Yoshiyuki , Takashima Matsuko 
Published: July 2006

Abstract
Acetyl derivatives of 2, 3-dimethylbenzofuran and their methyl homologs were derived into the corresponding carboxylic acids by the haloform reaction, and the acetylation of thier esters by the Friedel-Crafts reaction was studied. The keto-esters obtained were hydrolyzed to give keto-acids, which were then further oxidized into dicarboxylic acids by the haloform reaction and decarboxylated to acetylbenzofurans. On the other hand, the dicarboxylic acids were also obtained by the oxidation of diacetylbenzofurans. By the haloform reaction of hindered acetyl compounds, we obtained only halogenated ketones, which it was difficult to hydrolyze to give carboxylic acids. After the structures of these products had been determined and compared, it became clear that the acetylation of 5-alkoxycarbonyl-2, 3-dimethylbenzofurans furnished the 6-acetylated compounds, while that of 6-alkoxycarbonyl compounds and their methyl homologs furnished the 4-acetylated compounds.
Studies of the ζ-Potential of Natural and Synthetic Fibers in Dye Solutions. XVII. ζ-Potential and Surface Dyeability of Drawn Nylon 6 Fiber in an Acid Dye Solution
Authors: Suzawa Toshiro , Saito Tomoyuki , Shinohara Hideki 
Published: July 2006

Abstract
In order to ascertain the relation between the change in the fine structure and the dyeability of the nylon 6 fiber with its drawing, the ζ-potential, the surface dye adsorption, and the total dye adsorption of the drawn nylon 6 fiber in an acidic solution (pH 3.0) of acid dye—Orange II and Orange I were determined. The crystallinity and the birefringence of the fiber increase as the draw ratio increases. The isoelectric points of the fibers with the draw ratios of 1 (undrawn), 3, and 4 are pH 5.2, pH 5.4, and pH 5.4 respectively. The increase in the dye concentration changed the sign of the ζ-potential of these fibers in a dye solution from positive to negative and increased the absolute values of the ζ-potential. Moreover, it was suggested that these fibers combine with dye by electrostatic bonds. The surface dye adsorption as calculated from the difference between the surface charge density, Δσ, of the system with dye and that without dye increased in any case as the dye concentration increased. These values became smaller in the order of draw ratios: 1 (undrawn), 3, and 4. The total dye adsorption as well as the surface dye adsorption increased with the increase in the dye concentration and decreased with the drawing. Moreover, the surface areas covered by adsorbed dye molecules, which were calculated from the slope of the graph between the surface dye adsorption and the total dye adsorption, were 4.4, 2.9, and 1.8×106cm2/g fiber in the order of draw ratios: 1 (undrawn), 3, and 4. Also, the effect of the molecular structure of the dye on the ζ-potential, the surface dye adsorption, and the total dye adsorption was discussed.
Polarographic Behavior of Diethylenetriaminepentaacetic Acid at the Dropping Mercury Electrode
Authors: Kodama Mutsuo , Kimura Akiko 
Published: July 2006

Abstract
Anodic waves of DTPA at DME in the presence and in the absence of calcium(II) and magnesium(II) ions were studied systematically, and the stability constants of mercury(II)-DTPA chelates were determined. The electrode reaction for the anodic waves of DTPA proceeds reversibly in a polarographic sense. In the presence of magnesium(II) ions, however, DTPA gives an irreversible wave. This may be ascribed to the slow reaction of the magnesium(II)-DTPA chelate. The use of DTPA as a titrant in the amperometric titration of metal ions which do not yield a polarographic wave under the usual polarographic conditions was also discussed briefly.
The Cyclization of Ethyl Cyanoacetate and Ketones by Ammonium Acetate
Authors: Sakurai Akio , Midorikawa Hiroshi 
Published: July 2006

Abstract
It was found that a cyclized product containing one nitrogen atom could be obtained by the reaction of ethyl cyanoacetate with various ketones in the presence of excessive ammonium acetate. On the basis of this experiment, pyridone derivatives such as 3-cyano-5,6-dihydro-4,6-dialkyl-6-methyl-2-pyridones (I), pyridine derivatives such as 3-cyano-4,6-dialkyl-2-hydroxypyridines (IV), quinoline derivatives such as 4-alkyl-3-cyano-2-hydroxy-5,6,7,8-tetrahydroquinolines (VII), and related heterocyclic compounds were prepared.
Heat Capacities and Thermodynamic Properties of Ammonium Nitrate Crystal: Phase Transitions between Stable and Metastable Phases
Authors: Nagatani Masanori , Seiyama Tetsuro , Sakiyama Minoru , Suga Hiroshi , Seki Syûzô 
Published: July 2006

Abstract
The heat capacities of ammonium nitrate were measured between 15 and 410°K for the stable and metastable phases by use of adiabatic- and conduction-type calorimeters. The phase transformations between stable phases; i.e., V–IV, IV–III, III–II and II–I, and the metastable one between IV and II, were all found to be of first-order type. The direct transition between V and II, which is only realized for the sample treated with a minute amount of surface active agent, was ascertained to be typical higher-order type. Heat and entropy of transition of five kinds of transitions were determined. These results conclude that the heat capacity data by Stephenson et al. at low temperature region are much more reliable than the recent values by Eichenauer et al. The possibility of the existence of the seventh phase below 156°K has been proposed.
Studies of the Alkaline Earth Complexes in Various Solutions. III. Calcium(II) and Strontium(II) Complexes with Sulfate and Oxalate Ions in 1m Perchlorate Media
Authors: Hasegawa Yuko , Maki Kiyohiko , Sekine Tatsuya 
Published: July 2006

Abstract
The complex formation of calcium and strontium with sulfate and oxalate ions has been studied in 1 m perchlorate media at 25 °C by a liquid-liquid distribution method. The radioisotopes, calcium-45 and strontium-85 at tracer concentrations were used in conjunction with, thenoyltrifluoroacetone in methylisobutylketone or in carbon tetrachloride containing tributyl-phosphate. The complex formation was determined by a graphical method from the decrease in the extraction of the metal ions with the increases in the concentration of sulfate or oxalate ions in the aqueous phase. The results were explained by the formation of the first and the second complexes, and the stability constants, βn=[MLn2−2n]⁄[M2+][L2−]n, were determined as follows; Sulfate systems, Ca(II): logβ1=1.10, logβ2=1.36, Sr(II): log⁄β1=0.72, logβ2=1.29. Oxalate systems, Ca(II): logβ1=1.66, logβ2=2.69, Sr(II): logβ1=1.25, logβ2=1.90.
Kinetic Study of the Reaction between Uranium Monocarbide and Water Vapor
Authors: Hori Yoshio , Mukaibo Takashi 
Published: July 2006

Abstract
The rate of the reaction between uranium monocarbide and water vapor was investigated in a flow system under the conditions of 53–90°C and 20–120 mmHg. The rate of evolution and the composition of gases were measured by means of a gas chromatograph. The reaction versus time curve was sigmoid-shaped and found to be divided into three parts. Avrami’s equation for nucleation and growth fit the first part. The second part was expressed by a quasi first order reaction. Rate constants for the first and the second parts were found to depend on the water vapor pressure, obeying Langmuir’s adsorption isotherm. The activation energy for reaction and the heat of adsorption for the first part were determined to be 13.0 and 3.9 kcal/mol respectively.
Studies of Organic Peroxides. X. The Reaction of Benzoyl Peroxide with Secondary Amines
Authors: Kashino Setsuo , Mugino Yutaka , Hasegawa Shigeo 
Published: July 2006

Abstract
The reaction of benzoyl peroxide with secondary amines, namely diphenylamine, diethylamine, piperidine and pyrrolidine was studied in benzene. The rates of reactions were followed by the thermal analysis and the titration method. The rates of reactions of these amines increase in the order diethylamine&lt;diphenylamine&lt;piperidine&lt;pyrrolidine. The effect of the p, p′-substituents of benzoyl peroxide on the reaction rate was examined. The Hammett relationship with respect to p, p′-substituents held for all amines with positive ρ values. It was concluded that the reactions involve nucleophilic attack by the amines on the peroxide. Stoichiometry of the reaction was also examined by the method of thermal analysis. Diethylamine reacts with the peroxide in the 2 : 1 amine-peroxide ratio, while piperidine about 1.3 : 1 and diphenylamine 0.6 : 1, respectively. ESR spectra showed that diphenylamine and diethylamine produce fairly stable free radicals in low yields, while piperidine and pyrrolidine do not yield, detectable free radicals.