bluuebunny/crossref_metadata_2025_split huggingface dataset:
Inhibition by ATP and activation by ADP in the regulation of flagellar movement in sea urchin sperm
Authors: Yoshimura Azumi , Nakano Izumi , Shingyoji Chikako 
Published: August 2007

AbstractATP and ADP are known to play inhibitory and activating roles, respectively, in the regulation of dynein motile activity of flagella. To elucidate how these nucleotide functions are related to the regulation of normal flagellar beating, we examined their effects on the motility of reactivated sea urchin sperm flagella at low pH. At pH 7.0–7.2 which is lower than the physiological pH of 8, about 90% of reactivated flagella were motionless at 1 mM ATP, while about 60% were motile at 0.02 mM ATP. The motionless flagella at 1 mM ATP maintained a single large bend or an S‐shaped bend, indicating formation of dynein crossbridges in the axoneme. The ATP‐dependent inhibition of flagellar movement was released by ADP, and was absent in outer arm‐depleted flagella. Similar inhibition was also observed at 0.02 mM ATP when demembranated flagella were reactivated in the presence of Li+ or pretreated with protein phosphatase 1 (PP1). ADP also released this type of ATP‐inhibition. In PP1‐pretreated axonemes the binding of a fluorescent analogue of ADP to dynein decreased. Under elastase‐treatment at pH 8.0, the beating of demembranated flagella at 1 mM ATP and 0.02 mM ATP lasted for ∼100 and 45 s, respectively. The duration of beating at 0.02 mM ATP was prolonged by Li+, and that at 1 mM ATP was shortened by removal of outer arms. These results indicate that the regulation of on/off switching of dynein motile activity of flagella involves ATP‐induced inhibition and ADP‐induced activation, probably through phosphorylation/dephosphorylation of outer arm‐linked protein(s). Cell Motil. Cytoskeleton 2007. © 2007 Wiley‐Liss, Inc.
Electric field‐induced polarization of charged cell surface proteins does not determine the direction of galvanotaxis
Authors: Finkelstein Erik I. , Chao Pen‐hsiu Grace , Hung Clark T. , Bulinski Jeannette Chloë 
Published: August 2007

AbstractGalvanotaxis, that is, migration induced by DC electric fields, is thought to play a significant role in development and wound healing, however, the mechanisms by which extrinsic electric fields orchestrate intrinsic motility responses are unknown. Using mammalian cell lines (3T3, HeLa, and CHO cells), we tested one prevailing hypothesis, namely, that electric fields polarize charged cell surface molecules, and that these polarized molecules drive directional motility. Negatively charged sialic acids, which contribute the bulk of cell surface charge, redistribute preferentially to the surface facing the direction of motility, as measured by labeling with fluorescent wheat germ agglutinin. We treated cells with neuraminidase to remove sialic acids; as expected, this decreased total cell surface charge. We also changed cell surface charge independent of sialic acid moieties, by conjugating cationic avidin to the surface of live cells. Neuraminidase inhibited the electric field‐induced directional polarization of membrane ruffling and α4 integrin, while avidin treatment actually reversed the directional polarization of sialic acids. Neuraminidase treatment inhibited directionality but did not alter speed of motility. Surprisingly, avidin treatment did not significantly alter either directionality or speed of motility. Thus, our results demonstrate that electric field‐induced polarization of charged species indeed occurs. However, polarization of the bulk of charged cell surface proteins is neither necessary nor sufficient to cause motility, thus contradicting the second part of our hypothesis. Because neuraminidase inhibited directional motility, we also conclude that sialic acids are required constituents of some cell surface molecule(s) through which electric fields mount a polarized transmembrane response. Cell Motil. Cytoskeleton 2007. © 2007 Wiley‐Liss, Inc.
D‐ and L‐[123I]‐2‐I‐phenylalanine show a long tumour retention compared with D‐ and L‐[123I]‐2‐I‐tyrosine in R1M rhabdomyosarcoma tumour‐bearing Wag/Rij rats
Authors: Bauwens Matthias , Lahoutte Tony , Kersemans Ken , Caveliers Vicky , Bossuyt Axel , Mertens John 
Published: August 2007

AbstractThe aim of this study was the comparison of the tumour uptake and the long‐term retention of [123I]‐2‐I‐L‐phenylalanine and [123I]‐2‐I‐D‐phenylalanine with those of [123I]‐2‐I‐L‐tyrosine and [123I]‐2‐I‐D‐tyrosine in R1M rhabdomyosarcoma tumour‐bearing rats. The biodistribution of the radioactivity as a function of time in R1M tumour‐bearing rats was measured by planar gamma camera imaging (dynamic and static). If dissection was applied, the activity in the tumours and tissues of interest was measured by gamma counting. [123I]‐2‐iodo‐L‐phenylalanine, [123I]‐2‐iodo‐D‐phenylalaine, [123I]‐2‐I‐L‐tyrosine showed a considerable tumour uptake reaching a maximum between 10 and 30 min. At 30 min p.i. the differential uptake ratio values of this uptake were, respectively, 2.1, 2.3, 2.5 and 1.7. The activity in the tumour was shown to be related to a tumour cell uptake and not to an increased blood pool activity. All the tracers showed a clearance from the blood to the bladder without renal retention. At longer times both L‐ and D‐ [123I]‐2‐I‐tyrosine were cleared for a large part from the tumours and the body. [123I]‐2‐I‐L‐Phe and [123I]‐2‐I‐D‐Phe showed a considerable and equal retention in the tumours: as compared with 0.5 h, 91% at 24 h and 80% at 48 h. This was related to the longer retention of activity in the blood pool noticed for these compounds (81% at 24 h and 65% at 48 h). The tumour‐to‐background ratio increased with 25% at those longer times. At short times all the tracers were taken up to a considerable extent in the tumours. In the R1M‐bearing Wag/Rij rat model only [123I]‐2‐I‐L‐phenylalanine and [123I]‐2‐I‐D‐phenylalanine showed an especially high retention at long times without any significant difference between the enantiomers. Copyright © 2007 John Wiley & Sons, Ltd.
Risk factors for early catheter‐related infections in cancer patients
Authors: Penel Nicolas , Neu Jean‐Charles , Clisant Stéphanie , Hoppe Helga , Devos Patrick , Yazdanpanah Yazdan 
Published: August 2007

AbstractBACKGROUND.Early catheter‐related infection is a serious complication in cancer treatment, although risk factors for its occurrence are not well established. The authors conducted a prospective study to identify the risk factors for developing early catheter‐related infection.METHODS.All consecutive patients with cancer who underwent insertion of a central venous catheter were enrolled and were followed prospectively during 1 month. The study endpoint was occurrence of early catheter‐related infection.RESULTS.Over 10,392 catheter‐days of follow‐up, 14 of 371 patients had early catheter‐related infections (14 patients in 10,392 catheter‐days or 1.34 per 1000 catheter‐days). The causative pathogens were gram positive in 11 of 14 patients. In univariate analysis, the risk factors for early catheter‐related infection were aged <10 years (P = .0001), difficulties during insertion (P < 10−6), blood product administration (P < 10−3), parenteral nutrition (P < 10−4), and use >2 days (P < 10−6). In multivariate analysis, 3 variables remained significantly associated with the risk of early catheter‐related infection: age <10 years (odds ratio [OR], 18.4; 95% confidence interval [95% CI], 1.9–106.7), difficulties during insertion procedure (OR, 25.6; 95% CI, 4.2–106), and parenteral nutrition (OR, 28.5; 95% CI, 4.2–200).CONCLUSIONS.On the day of insertion, 2 variables were identified that were associated with a high risk of developing an early catheter‐related infection: young age and difficulties during insertion. The results from this study may be used to identify patients who are at high risk of infection who may be candidates for preventive strategies. Cancer 2007. © 2007 American Cancer Society.
Immunotherapy of murine colon cancer using receptor tyrosine kinase EphA2‐derived peptide‐pulsed dendritic cell vaccines
Authors: Yamaguchi Shinjiro , Tatsumi Tomohide , Takehara Tetsuo , Sakamori Ryotaro , Uemura Akio , Mizushima Tsunekazu , Ohkawa Kazuyoshi , Storkus Walter J. , Hayashi Norio 
Published: August 2007

AbstractBACKGROUND.Further optimization of dendritic cell (DC)‐based vaccines is required clinically against advanced stage cancer. Given the broad range of expression levels observed in the recently defined tumor antigen EphA2 in a diverse types of cancers, especially in advanced stage or metastatic cancers, the authors evaluated the effectiveness of vaccination using DCs pulsed with EphA2‐derived peptides (Eph‐DCs) in a murine colon cancer model.METHODS.EphA2 protein expression levels were evaluated in advanced colorectal carcinoma tissues from 10 patients by Western blot analysis. C57BL/6 mice were immunized with Eph‐DCs twice weekly. Interferon γ (IFN‐γ) ELISPOT assays were used for the analysis of CD8‐positive T cells that were specific for EphA2‐derived peptide. Immunized mice were challenged subcutaneously with EphA2‐positive murine colorectal adenocarcinoma (MC38) mouse colon tumors or with EphA2‐negative BL6 melanoma tumors. In some experiments, mice were injected with anti‐CD8, anti‐CD4, or antiasialo GM1 antibody to deplete corresponding lymphocyte subsets.RESULTS.Among 10 samples of advanced colorectal carcinoma, 6 samples (60%) overexpressed EphA2. IFN‐γ ELISPOT assays revealed that EphA2‐derived peptide‐specific CD8‐positive T cells were generated by immunization with Eph‐DCs. Immunization with Eph‐DCs inhibited MC38 tumor growth compared with immunization using unpulsed DCs or phosphate‐buffered saline. In contrast, Eph‐DC vaccination had no effect on BL6 growth. Antibody depletion studies revealed that both CD8‐positive T cells and CD4‐positive T cells, but not natural killer cells, played critical roles in the efficacy observed for immunizations with Eph‐DCs. Eph‐DC vaccines resulted in long‐term antitumor immunity against a rechallenge with MC38 tumor cells.CONCLUSIONS.The current results demonstrated that Eph‐DC vaccines may represent a promising preventative/therapeutic modality in the cancer setting. Cancer 2007. © 2007 American Cancer Society.
Provenance in collection‐oriented scientific workflows
Authors: Bowers Shawn , McPhillips Timothy M. , Ludäscher Bertram 
Published: August 2007

AbstractWe describe a provenance model tailored to scientific workflows based on the collection‐oriented modeling and design paradigm. Our implementation within the Kepler scientific workflow system captures the dependencies of data and collection creation events on preexisting data and collections, and embeds these provenance records within the data stream. A provenance query engine operates on self‐contained workflow traces representing serializations of the output data stream for particular workflow runs. We demonstrate this approach in our response to the first provenance challenge. Copyright © 2007 John Wiley & Sons, Ltd.
Synthesis and characterization of tetraprolinium silicotungstic acid tetra‐hydrate, a new organic‐inorganic hybrid based on polyoxometallates
Authors: Alizadeh M. H. , Tayebee R. , Mirzaei M. 
Published: August 2007

AbstractA new solvated polyoxometallate bearing an amino acid, (I), has been prepared for the first time by the reaction of 0.16 mmol α‐H4SiW12O40.15H2O with 0.78 mmol of L‐proline in hydrochloric acid at pH 3. The structure of (I) was substantially characterized by some physical approaches, such as elemental analysis, infrared spectroscopy, and 1H‐NMR. Our findings proved that (I) could be formulated as [L‐C5H10NO2]4[SiW12O40].4H2O. It is believed that the electrostatic attractions and hydrogen bonding between tungstosilisic acid and the prolinium cation affected the structure of (I). It is evident that the polyoxometallates moieties were arranged in good order to form large holes in the structural backbone. These cavities were occupied by the prolinium cations and water molecules. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Photorefractive features of non‐stoichiometry codoped Hf:Fe:LiNbO3 single crystals
Authors: Bo Liu , Chunliang Li , Jiancong Bi , Liang Sun , Yuheng Xu 
Published: August 2007

AbstractHf(2mol%):Fe(0.05wt%):LiNbO3 crystals with various [Li]/[Nb] ratios of 0.94, 1.05, 1.2 and 1.38 have been grown. The photorefractive resistant ability increases with the accretion of [Li]/[Nb] ratio. When the ratio of [Li]/[Nb] is 1.20 or 1.38, the OH‐ absorption band shifts to about 3477cm‐1. The mechanisms of the photorefractive resistant ability increase and the absorption band shift have been discussed. The exponential gain coefficient (Γ) of the crystals was measured with two‐beam coupling method and the effective charge carrier concentration (Neff) was calculated. The results show that Γ and Neff increase with the accretion of [Li]/[Nb] ratio. The temperature effect of codoped Hf:Fe:LiNbO3 crystals was also studied, it was found that the exponential gain coefficient increase dramatically at about 55°C, 70°C and 110°C, this is due to the inner electric field which is resulted from structure phase change. (© 2007 WILEY ‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Both Langerhans cells and interstitial DC cross‐present melanoma antigens and efficiently activate antigen‐specific CTL
Authors: Cao Tinghua , Ueno Hideki , Glaser Casey , Fay Joseph W. , Palucka A. Karolina , Banchereau Jacques 
Published: August 2007

AbstractDendritic cells (DC) have a unique capacity to present external antigens to CD8+ T cells, i.e. cross‐presentation. However, it is not fully established whether the ability to cross‐presentation is restricted to a unique subset of DC in humans. Here, we show that two major myeloid DC subsets, i.e. Langerhans cells (LC) and interstitial DC (Int‐DC), have the ability to cross‐present antigens to CD8+ T cells in vitro. LC and Int‐DC were obtained from DC generated by culturing human CD34+‐hematopoietic progenitor cells with GM‐CSF, FLT3‐L, and TNF‐α (CD34‐DC). Both DC subsets were able to capture necrotic/apoptotic allogeneic melanoma cells and present antigens to CD8+ T cells, resulting in efficient priming of naive CD8+ T cells into CTL capable of killing melanoma cells. Strikingly, a single stimulation with either subset (LC or Int‐DC) or total CD34‐DC loaded with necrotic/apoptotic melanoma cells was sufficient to activate melanoma‐specific memory CD8+ T cells obtained from patients with metastatic melanoma to become effective CTL. Thus, this study provides the rationale to use CD34‐DC loaded with necrotic/apoptotic allogeneic melanoma cells in a clinical trial.
The Foxn1‐dependent transcripts PCOLCE2 and mPPP1R16B are not required for normal thymopoiesis
Authors: Heinzel Kornelia , Bleul Conrad C. 
Published: August 2007

AbstractThe adaptive immune system relies on the thymic microenvironment for the production of a diverse, self‐tolerant T cell receptor repertoire. The central cellular organizer of the thymic microenvironment is the thymic epithelial cell (TEC). The development of TEC from endodermal precursor cells is under the control of the forkhead/winged helix transcription factor Foxn1 but the transcriptional program that leads to this unique epithelial differentiation has not been investigated functionally. Here, we show that expression of procollagen C‐proteinase enhancer 2 (PCOLCE2) is absent in Foxn1‐deficient TEC. In order to study the functional role of this gene in TEC differentiation, we have genetically inactivated PCOLCE2 and the gene encoding phosphatase 1 regulatory inhibitory subunit 16B (mPPP1R16B), another transcript lacking in Foxn1‐deficient TEC. Mice deficient for either one or both of these transcripts presented a normal thymic microenvironment and undisturbed thymopoiesis. While there is no evidence for a functional role of PCOLCE2 and mPPP1R16B in thymus development, our results suggest that the lack of thymopoiesis in Foxn1‐deficient mice is caused by multiple functional defects.
Mannan and peptidoglycan induce COX‐2 protein in human PMNviathe mammalian target of rapamycin
Authors: Fernández Nieves , González Ana , Valera Isela , Alonso Sara , Crespo Mariano Sánchez 
Published: August 2007

AbstractThe induction of cyclooxygenase‐2 (COX‐2) protein expression was assessed in human polymorphonuclear leukocytes (PMN) stimulatedviareceptors of the innate immune system. Peptidoglycan (PGN) and mannan, and at a lower extent the bacterial lipoprotein mimic palmitoyl‐3‐cysteine‐serine‐lysine‐4, induced COX‐2 protein expression. In contrast, lipoteichoic acid and muramyldipeptide were irrelevant stimuli. The mRNA encoding COX‐2 was present in resting PMN at an extent quite similar to that detected in stimulated PMN, whereas the expression of COX‐2 protein was undetectable. Treatment with the phosphatidylinositol 3‐kinase inhibitor (PI3K) wortmaninn, the mammalian target of rapamycin (mTOR) inhibitor rapamycin, and the translation inhibitor cycloheximide blocked the induction of COX‐2 protein in response to mannan and PGN, whereas the transcriptional inhibitor actinomycin D did not show a significant effect. These results disclose a capability of pathogen‐associated molecular patterns to induce the oxidative metabolism of arachidonic acid more robust than that of PMN archetypal chemoattractants, since mannan and PGN make it coincidental the release of arachidonic acid with a rapid induction of COX‐2 protein regulated by a signaling cascade involving PI3K, mTOR, and the translation machinery. This mechanism of COX‐2 protein induction expression in PMN is substantially different from that operative in mononuclear phagocytes, which is highly dependent on transcriptional regulation.
Reciprocal generation of Th1/Th17 and Treg cells by B1 and B2 B cells
Authors: Zhong Xuemei , Gao Wenda , Degauque Nicolas , Bai Chunyan , Lu Yan , Kenny James , Oukka Mohamed , Strom Terry B. , Rothstein Thomas L. 
Published: August 2007

AbstractRegulatory T (Treg) cells are indispensable for maintaining peripheral tolerance, whereas T helper (Th)1 and Th17 cells induce inflammation and tissue destruction. Using Foxp3‐GFP knock‐in mice, we report a novel regulatory role for B cell subsets in influencing the differentiation of Treg versus Th1/Th17 cells. Peritoneal B1 cells strongly promoted T cell proliferation and cytokine secretion when presenting nominal or allogeneic antigens, as compared to conventional follicular B (B2) cells. However, peritoneal B1 cells largely failed to convert naive Foxp3–CD4+ T cells into Foxp3+ Treg cells in the presence of TGF‐β and IL‐2, in marked contrast to conventional B2 cells, which excelled in Treg conversion. Interestingly, under the same Treg conversion conditions, peritoneal B1 cells preferentially promoted Th1 and Th17 cell differentiation. Blockade of CD86 but not CD80 costimulation markedly enhanced Treg cell induction by B1 cells. Thus, B cell antigen presentation function is inversely correlated with de novo Treg cell induction for these B cell subsets. Our findings suggest that B1 and B2 cell subsets play distinct roles in immune regulation by promoting reciprocal differentiation of T cell lineages.
Cooperative Spin‐Crossover Behaviour in Polymeric 1D FeII Coordination Compounds: [{Fe(tba)3}X2]·nH2O
Authors: Seredyuk Maksym , Gaspar Ana B. , Muñoz M. Carmen , Verdaguer Michel , Villain Françoise , Gütlich Philipp 
Published: August 2007

AbstractA new family of 1D cooperative spin‐crossover polymers with general formula [{Fe(tba)3}X2]·nH2O [tba = N‐(4H‐1,2,4‐triazol‐4‐yl)benzamide; X = CF3SO3–, n = 2 (1), n = 0 (4); BF4–,n = 3 (2), n = 0 (5); 4‐CH3C6H4SO3–, n = 3 (3), n = 0 (6)] has been synthesised and characterised using a series of spectroscopic methods, X‐ray powder diffraction, magnetic susceptibility measurements and differential scanning calorimetry. The copper analogue of 1, [{Cu(tba)3}(CF3SO3)2]·3H2O (7), has also been synthesised and its crystal structure solved at 293 K. Compound 7 crystallises in the P$\bar {1}$ space group. The bidentate N‐(4H‐1,2,4‐triazol‐4‐yl)benzamide ligand bridges the copper ions through the 1,2‐nitrogen positions leading to a one‐dimensional infinite polymer. The EXAFS data collected at 80 K for 1 agree perfectly with a linear chain structure, as observed for 7, with [Fe(tba)3] chromophores linked to each other through the adjacent nitrogen atoms of three N‐(4H‐1,2,4‐triazole‐4‐yl)benzamide ligands. IR spectroscopic studies confirm the retention of the C2v symmetry for the triazole rings in 2 and 3, thereby suggesting a similar chainlike arrangement in these compounds. Compound 1 is low spin (LS) at room temperature while 2 and 3 are high spin (HS). The latter two complexes undergo cooperative thermal spin transition at Tc↓ = 250 and Tc↑ = 258 K in 2 and Tc↓ = 226 and Tc↑ = 238 K in 3. The spin transition in 2 and 3 is accompanied by a change of colour from white in the HS state to violet in the LS state. The thermodynamic parameters associated with the spin transition estimated from DSC measurements are ΔH = 17.8 (2) and 14.6 kJ mol–1 (3), and ΔS = 67.2 (2) and 63.5 J K–1 mol–1 (3). In contrast, the dehydrated compounds 4, 5 and 6 show very different spin‐transition behaviour. Complex 4 exhibits an abrupt spin transition centred at room temperature and is accompanied by a relatively large hysteresis loop with a width of 25 K (ΔH = 19.7 kJ mol–1 and ΔS = 65.6 J K–1 mol–1). Like 2 and 3, 4 shows a dramatic colour change upon the spin transition. Complex 5 shows a continuous and incomplete spin transition, and 6 is HS over the whole temperature range investigated (10–400 K). (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)
Supramolecular Click Assembly of a Fused Double‐Stranded [MnII3] Dihelicate
Authors: Tang Jinkui , Costa José Sánchez , Aromí Guillem , Mutikainen Ilpo , Turpeinen Urho , Gamez Patrick , Reedijk Jan 
Published: August 2007

AbstractA trinuclear MnII complex was obtained by reaction of manganese(II) perchlorate with the ligand 2‐methoxy‐6‐(pyridine‐2‐ylhydrazonomethyl)phenol in methanol. The X‐ray crystal structure of [Mn3L4](ClO4)2(H2O)2 (1) reveals that the “bent” chain of the MnII ions is assembled by a unique click‐assembly of two double‐stranded helicates. Magnetic susceptibility measurements show weak ferromagnetic interactions between the metal ions. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)
Ultra‐Low Catalyst Loading as a Concept in Economical and Sustainable Modern Chemistry: The Contribution of Ferrocenylpolyphosphane Ligands (Eur. J. Inorg. Chem. 24/2007)
Authors: Hierso Jean‐Cyrille , Beaupérin Matthieu , Meunier Philippe 
Published: August 2007

AbstractThe cover picture shows an X‐ray illustration of the multidentate ferrocenylpolyphosphane 1,1′,2,2′‐tetrakis(diphenylphosphanyl)‐4,4′‐di‐tert‐butylferrocene. The cisoid conformation of the molecule, evidenced at the solid state, is conserved in solution; the phosphorus arrangement led to a rarely demonstrated multiple‐coordination behaviour towards palladium, possibly useful in ultra‐low catalyst loading reactions due to an improved stabilization of the metal atom. The multiple phosphane arms and their orientation resemble the elegant and intelligent creature that is the Giant Pacific Octopus (specimen from the Alaska SeaLife Centre in Seward, photo published with the kind permission of Mollie Tubbs and Jason Wettstein). The catalytic performance in palladium cross‐coupling at ultra‐low catalyst loading is presented in the Microreview by J.‐C. Hierso et al. on page 3767 ff.