bluuebunny/crossref_metadata_2025_split huggingface dataset:
Nuclear microenvironments support assembly and organization of the transcriptional regulatory machinery for cell proliferation and differentiation
Authors: Stein Gary S. , Lian Jane B. , van Wijnen Andre J. , Stein Janet L. , Javed Amjad , Montecino Martin , Zaidi S. Kaleem , Young Daniel , Choi Je‐Yong , Gutierrez Soraya , Pockwinse Shirwin 
Published: January 2004

AbstractThe temporal and spatial organization of transcriptional regulatory machinery provides microenvironments within the nucleus where threshold concentrations of genes and cognate factors facilitate functional interactions. Conventional biochemical, molecular, and in vivo genetic approaches, together with high throughput genomic and proteomic analysis are rapidly expanding our database of regulatory macromolecules and signaling pathways that are requisite for control of genes that govern proliferation and differentiation. There is accruing insight into the architectural organization of regulatory machinery for gene expression that suggests signatures for biological control. Localized scaffolding of regulatory macromolecules at strategic promoter sites and focal compartmentalization of genes, transcripts, and regulatory factors within intranuclear microenvironments provides an infrastructure for combinatorial control of transcription that is operative within the three dimensional context of nuclear architecture. © 2003 Wiley‐Liss, Inc.
Gene array identification of osteoclast genes: Differential inhibition of osteoclastogenesis by cyclosporin A and granulocyte macrophage colony stimulating factor
Authors: Day Christopher J. , Kim Michael S. , Stephens Sébastien R.J. , Simcock Wendy E. , Aitken Cathy J. , Nicholson Geoff C. , Morrison Nigel A. 
Published: January 2004

AbstractTreatment of adherent peripheral blood mononuclear cells (PBMCs) with macrophage colony stimulating factor (M‐CSF) and receptor activator of NF‐κB ligand (RANKL) stimulates the formation of multinucleate osteoclast‐like cells. Treatment with M‐CSF alone results in the formation of macrophage‐like cells. Through the use of Atlas human cDNA expression arrays, genes regulated by RANKL were identified. Genes include numerous cytokines and cytokine receptors (RANTES and CSF2R∝), transcription factors (nuclear factor of activated T‐cells cytoplasmic 1 (NFATc1) and GA binding protein transcription factor alpha (GABPα)), and ribosomal proteins (60S L17 and 40S S20). Real‐time PCR analysis showed significant correlation (R2 of 0.98 P < 0.01) with array data for all genes tested. Time courses showed differential activation patterns of transcription factors with early induction of FUSE binding protein 1 (FBP) and c‐Jun, and later steady upregulation of NFATc1 and GABP by RANKL. Treatment with cyclosporin A, a known NFATc1 inhibitor, resulted in a blockade of osteoclast formation. The mononuclear cells resulting from high cyclosporin treatment (1,000 ng/ml) were cathepsin K (CTSK) and tartrate‐resistant acid phosphatase (TRAP) positive but expression of calcitonin receptor (CTR) was downregulated by more than 30‐fold. Constant exposure of M‐CSF‐ and RANKL‐treated cells to GM‐CSF resulted in inhibition of osteoclast formation and the downregulation of CTSK and TRAP implicating the upregulation of CSF2R in a possible feedback inhibition of osteoclastogenesis. © 2004 Wiley‐Liss, Inc.
Physiology of hibernation inRana pipiens: metabolic rate, critical oxygen tension, and the effects of hypoxia on several plasma variables
Authors: Ultsch Gordon R. , Reese Scott A. , Stewart E. Ray 
Published: January 2004

AbstractRates of O2consumption (V̇O2) were determined for adult northern leopard frogs (Rana pipiens) submerged at 3 °C at water PO2s (PwO2) ranging from 0–160 mmHg. The critical O2tension (Pc) was 36.4 mmHg. Hematocrit and blood levels of PO2, glucose, lactate, pH, [Na+], [K+], and osmolality were determined for frogs submerged for two days. Above a PwO2of 50 mmHg, blood PO2ranged from 1–7 mmHg, which was sufficient to allow the frogs to function entirely aerobically. Plasma [lactate] increased as PwO2fell below 50 mmHg, the increase preceding significant changes in any other variable, and apparently preceding a fall in V̇O2. Most other variables showed little or no change from those of air‐breathing control animals, even during anoxia. We present an analysis of the importance of a large decrease in Pcin permitting frogs to successfully overwinter in icebound ponds and of the factors that contribute to that decrease.J. Exp. Zool. 301A:169–176, 2004.© 2004 Wiley Liss, Inc.
Forelimb spike regeneration in Xenopus laevis: Testing for adaptiveness
Authors: Tassava Roy A. 
Published: January 2004

AbstractExperiments were designed to test adaptability of forelimb spike regenerates in Xenopus laevis froglets. The results show that when amputation is at the radius/ulna level, regeneration occurs in 100% of the cases and a single spike of cartilage is the result. The spike regenerates originating from radius/ulna level amputations can be used for feeding and froglet growth is only minimally compromised by the spike. The spike grows in length as the froglet body grows and thus is in homeostasis with the body. The spike develops nuptial pad tissue in reproductively mature males and is occasionally molted, indicating responsiveness to gonadal and thyroid hormones. Finally, and most important, the spike can be used for amplexus and successful mating. In contrast, spikes originating from humerus level amputations were considerably shorter and regeneration from that limb level was less frequent. When amputation was at the body wall regeneration did not occur. J. Exp. Zool. 301A:150–159, 2004. © 2004 Wiley‐Liss, Inc.
Lymphoid aggregates in gonads of embryos, hatchlings, and young of turtles with temperature‐dependent sex determination
Authors: Belaïd Baya , Cong Han Nguyen , Devilliers Ginette , Richard‐Mercier Noelle , Pieau Claude , Dorizzi Mireille 
Published: January 2004

AbstractCellular infiltrations forming lymphoid‐like aggregates were previously observed in gonads of two turtle species exhibiting temperature‐dependent sex determination (TSD): at hatching in Chelydra serpentina ; at and after hatching in Emys orbicularis. We show here that such aggregates are also present in gonads of Testudo graeca by the end of embryonic development, suggesting that their occurrence is general in turtles. Since in C. serpentina, infiltrations were observed mainly in testes exhibiting remnants of the germinal epithelium, it was assumed that their occurrence was an expression of maleness leading to rejection of this epithelium. The generality of this hypothesis was tested in E. orbicularis by looking for lymphoid‐like aggregates in three types of gonads (testes, ovotestes, and ovaries) and for the stages at which they occur. Gonads were from embryos, hatchlings, and young incubated at various temperatures. Ovotestes obtained by treatment with an aromatase inhibitor of eggs incubated at female‐producing temperature were also examined. In these gonads, the differentiation of Sertoli cells in testicular cords/tubes was ascertained by expression of SOX9. Moreover, the cell composition of aggregates was determined on electron micrographs. Aggregates appear in ovaries and ovotestes by the end of embryonic development and are present in the majority of these gonads at hatching, and at least up to one year after hatching. They are composed mainly of lymphocytes and fibroblasts. Aggregates are not present in typical testes. Since they occur in most ovaries, they cannot be seen as an expression of maleness. Rather, lymphocytic infiltration and formation of lymphoid aggregates in turtle gonads can be seen as components of the immune system, and can be under the control of gonadal endogenous sex steroids. J. Exp. Zool. 301A:160–168, 2004. © 2004 Wiley‐Liss, Inc.
Pluripotency of cryopreserved blastomeres of the goldfish
Authors: Kusuda Satoshi , Teranishi Tetsuo , Koide Nobuhisa , Nagai Terumi , Arai Katsutoshi , Yamaha Etsuro 
Published: January 2004

AbstractTo examine the pluripotency of cryopreserved blastomeres, we transplanted them into blastula. Donor blastomeres were prepared from blastula of goldfish (Carassius auratus) and cryopreserved in liquid nitrogen for two months. Fifty‐five percent and 44% of blastomeres survived after thawing. Cryopreserved blastomeres were transplanted to the blastula of triploid crucian carp (C. a. longsdorfii), which reproduces gynogenetically in nature. At four days after the operation, resultant chimeric embryos transplanted with cryopreserved blastomeres showed a survival rate (41.6%) lower than that of embryos transplanted with unfrozen blastomeres (57.1%). Transplanted blastomeres were histologically identified in various organs derived from all three germ layers. A primordial germ cell differentiated from a cryopreserved blastomere was detected in one of the 32 chimeric fish examined. These results suggest blastomeres that survive after cryopreservation retain their pluripotency and are able to differentiate into both somatic and germ cell lines. J. Exp. Zool. 301A:131–138, 2004. © 2004 Wiley‐Liss, Inc.
Aggregation effects on anhydrobiotic survival in the tardigrade Richtersius coronifer
Authors: Ivarsson Helen , JÖnsson K. Ingemar 
Published: January 2004

AbstractFor anhydrobiotic metazoans the rate of desiccation is an important factor influencing the probability of survival in a dry anhydrobiotic state. Formation of animal aggregations, in which the exposed body surface area of individual animals is reduced, represents one way to reduce the rate of evaporation. Such aggregations have earlier been documented in e.g., nematodes. We experimentally evaluate the effect of aggregation size (number of animals in a group of desiccating animals) on anhydrobiotic survival in the eutardigrade Richtersius coronifer. The experiment shows that aggregation provides a clear improvement on anhydrobiotic survival. The most likely explanation for this is that aggregated animals were exposed to a lower rate of desiccation. Although the empirical evidence of aggregation in tardigrades is scarce, our study suggests that aggregation could potentially be an important survival factor for tardigrades living in environments characterized by periods of rapid desiccation. J. Exp. Zool. 301A:195–199, 2004. © 2004 Wiley‐Liss, Inc.
Cyclic AMP‐dependent tyrosine phosphorylation in tammar wallaby (Macropus eugenii) spermatozoa
Authors: Bennetts Liga , Lin Minjie , Aitken R. John 
Published: January 2004

AbstractDespite considerable advances in our understanding of the molecular mechanisms regulating eutherian sperm function, there is a paucity of such knowledge for the Metatheria. In eutherian spermatozoa, the attainment of functional competence is associated with a redox‐regulated, cAMP‐mediated tyrosine phosphorylation cascade, activated during capacitation. In this report we investigate whether tammar wallaby (Macropus eugenii) spermatozoa possess a similar signal transduction pathway. Western blot analysis of phosphotyrosine expression in caudal and ejaculated populations of tammar spermatozoa revealed that elevation of intracellular cAMP levels, but not exposure to oxidants or NADPH, induced a dramatic increase in the overall level of tyrosine phosphorylation. Washed, ejaculated spermatozoa exhibited more pronounced increases in tyrosine phosphorylation than unwashed sperm populations. Localisation of tyrosine phosphorylation by immunocytochemistry showed that phosphotyrosine residues were principally located along the tammar sperm flagellum, and occasionally at a small region of the sperm head, adjacent to the acrosome. Associated with the tyrosine phosphorylation of tammar spermatozoa, was a change in sperm head conformation to a T‐shaped orientation, further implying the importance of these pathways to normal tammar sperm function. Redox activity, as detected by lucigenin‐dependent chemiluminescence, was stimulated by NADPH in caudal sperm preparations but not ejaculated spermatozoa. However, neither sperm population responded to treatment with NADPH with changes in intracellular cAMP or tyrosine phosphorylation. In conclusion, tammar spermatozoa possess the same cAMP‐mediated, tyrosine phosphorylation‐dependent signal transduction cascade that has been associated with capacitation in eutherian spermatozoa. However in Metatherian spermatozoa we could find no evidence that this pathway was redox regulated. J. Exp. Zool. 301A:118–130, 2004. © 2004 Wiley‐Liss, Inc.
Ligand effects upon deuterium exchange in arenes mediated by [Ir(PR3)2(cod)]+.BF4−
Authors: Ellames George J. , Gibson Jennifer S. , Herbert John M. , Kerr William J. , McNeill Alan H. 
Published: January 2004

AbstractA series of complexes of general form [Ir(PR3)2(cod)]+ has been prepared and used, without isolation, to mediate deuteration of a range of model substrates. The data suggest that, with many substrates, basicity of the phosphine ligands bound to iridium is an important factor influencing substrate selectivity and the efficiency of deuteration. In addition, the spectrum of activity of iridium complexes bearing pure donor ligands is different in many cases to that of complexes where the ligands are known to be π‐acids. Copyright © 2003 John Wiley & Sons, Ltd.
Synthesis of tritium labelled 3(R)‐HETE and 3(R),18(R/S)‐DiHETE through a common synthetic route
Authors: Groza Natalya V. , Ivanov Igor V. , Romanov Stepan G. , Shevchenko Valery P. , Myasoedov Nikolai F. , Nigam Santosh , Myagkova Galina I. 
Published: January 2004

AbstractAn efficient procedure for the synthesis of 3‐hydroxyoxylipins labelled with tritium on all double bond positions is reported. The synthetic scheme involves a joint route for the formation of tetraacetylenic precursors followed by stereoselective reduction of the triple bonds either with hydrogen or tritium. The final tritiated products were obtained with specific activities ranging from 1.65 to 1.80 Ci/mmol. Copyright © 2003 John Wiley & Sons, Ltd.
Synthesis of benzoxazole‐[phenyl‐13C6] by directed ortho‐metalation chemistry
Authors: Derdau Volker 
Published: January 2004

AbstractA new method for the preparation of benzoxazole‐[phenyl‐13C6] (1) starting from aniline‐[13C6] (4) has been developed involving directed ortho‐metalation (DoM) chemistry. The synthesis comprises four steps and an overall yield of 39% was obtained. Copyright © 2003 John Wiley & Sons, Ltd.
Synthesis of [2H8]‐enterolactone and [2H10]‐enterodiol
Authors: Leppälä Eija , Wähälä Kristiina 
Published: January 2004

AbstractEnterolactone and enterodiol are the main mammalian metabolites of dietary butyrolactone type lignans. The study of biological properties and potential health effects of these compounds requires isotopically labelled compounds as standards for quantitative measurements. An expedient deutero‐labelling method for enterolactone is to use the D3PO4·BF3/D2O complex at room temperature which will exchange all eight aromatic hydrogens, even from inactivated meta positions, to form [2,4,5,6,2′,4′,5′,6′‐2H8]‐enterolactone in 74% yield and 99% isotopic purity. [2,4,5,6,9,9,2′,4′,5′,6′‐2H10]‐Enterodiol was prepared from [2,4,5,6,2′,4′,5′,6′‐2H8]‐enterolactone by reduction with LiAlD4 which introduces two more deuterium atoms into the molecule. Copyright © 2003 John Wiley & Sons, Ltd.
Synthesis of carbon‐14 labelled l,5 diaryl‐[5‐14C]‐l,2,3‐triazolines
Authors: Matloubi Hojatollah , Shafiee Abbas , Saemian Nader , Shirvani Gholamhossein , Daha Fariba Johari 
Published: January 2004

AbstractTwo 1,2,3‐triazoline anticonvulsants, 1‐(4‐methylsulphone‐phenyl)‐5‐(4‐methoxy‐phenyl)‐1,2,3‐triazoline and l‐(4‐methylsulphone‐phenyl)‐5‐phenyl‐1,2,3‐triazoline, both labelled with carbon‐14 in the 5‐position, have been synthesized as part of a 5‐step sequence. Copyright © 2003 John Wiley & Sons, Ltd.
Preparation of fluorine‐18‐labelled fluoromisonidazole using two different synthesis methods
Authors: Kämäräinen Eeva‐Liisa , Kyllönen Teija , Nihtilä Outi , Björk Heikki , Solin Olof 
Published: January 2004

Abstract18F‐labelled fluoromisonidazole [1H‐1‐(3‐[18F]fluoro‐2‐hydroxypropyl)‐2‐nitroimida‐zole; ([18F]FMISO)] is used as an in vivo marker of hypoxic cells in tumours and ischaemic areas of the heart and the brain. The compound plays an important role in evaluating the oxygenation status in tumours during radiotherapy. In this paper, we report experiments carried out in our laboratory in synthesizing [18F]FMISO using two different methods. The first method (I) for the [18F]FMISO synthesis was the fluorination of (2R)‐(−)‐glycidyl tosylate to [18F]epifluorohydrin. The subsequent nucleophilic ring opening, achieved with 2‐nitroimidazole, leads to labelled FMISO. The second method (II) was the fluorination of the protected precursor 1‐(2′‐nitro‐1′‐imidazolyl)‐2‐O‐tetrahydropyranyl‐3‐O‐toluenesulphonyl‐propanediol, followed by a rapid removal of the protecting group. With the first method, the radiochemical yield was about 10% at the end of the synthesis (EOS), and the radiochemical purity was over 99%. The radiochemical yield in the second method was 21% (EOS) on an average, and the radiochemical purity was over 97%. When an automated commercial synthesis module was used with method II, slightly better and more reproducible yields were achieved. The improvement in the synthesis yield with the automated apparatus will be valuable when working with high activities, and therefore it is under further development. Copyright © 2003 John Wiley & Sons, Ltd.
Quality control methods for 99mTc‐labeled exogenous natural surfactant (99mTc‐ENS)
Authors: Calmanovici Gabriela P. , Caro Ricardo A. , Goldman Cinthia G. , Leonardi Natalia M. , Boccio José R. , Zubillaga Marcela B. 
Published: January 2004

AbstractTo standardize the quality control for 99mTc‐ENS, the following methods were studied: (1) physical properties and pH, (2) radiochemical purity (chromatographic studies on Whatman‐1 paper, or instant thin‐layer chromatography and solvent extraction using different solvents and (3) rat biodistribution studies by intratracheal injection. The tolerance limits were fixed for each method. The radiopharmaceutical stability was also evaluated. The results showed that 99mTc‐ENS was a white suspension with a pH between 4.0 and 6.0. The limit for radiochemical impurities in Whatman‐1 paper/acetone was fixed at lower than 2% and the established limit for the organic aliquot in cyclohexane extraction was greater than 2%. In the biodistribution studies, the limits for activity concentration were fixed at greater than 90% for lungs, less than 9% for the gastrointestinal system and less than 1% for the sum of the other organs studied. After a storage time of 6 h at room temperature or in a refrigerator, 99mTc‐ENS physical properties and pH, radiochemical and biodistribution results were within the established values. In conclusion, the quality control methods for 99mTc‐ENS are tests on physical properties and pH, radiochemical purity by Whatman‐1 paper/acetone chromatography and cyclohexane extraction and biodistribution studies in rats. The stability of this radiopharmaceutical is at least 6 h at room temperature. Copyright © 2003 John Wiley & Sons, Ltd.
Flixotide™‐pressurized metered‐dose inhalers loaded with [18F]fluticasone propionate particles for drug deposition studies in humans with PET–formulation and analysis
Authors: Constantinou Maria , Waters Stephen L. , Steel Colin J. , Poole Keith G. , Marino Phil S. , Ind Phillip W. , Rhodes Christopher G. , Aigbirhio Franklin I. , Moore Alison , Pike Victor W. , Luthra Sajinder K. 
Published: January 2004

AbstractFluticasone propionate (FP) is a potent anti‐inflammatory synthetic steroid, used for the treatment of asthma. Flixotide™ is a formulated pressurized metered‐dose inhaler (pMDI) that contains small‐micronized FP particles in a blend of CFC propellants. Our objective was to develop a radiotracer method for accurately measuring the regional deposition of FP within the human lung using positron emission tomography (PET), which would be of important clinical interest. Flixotide™ pMDIs were used to prepare [18F]FP pMDIs labeled isotopically with the positron emitter, fluorine‐18 (t1/2=109.7 min). FP particles from Flixotide™ pMDIs were mixed with [18F]FP formulated into a pMDI and sonicated at room temperature. The drug delivery of [18F]FP pMDI (250 μg of FP per actuation dose) was assessed for particle size distribution and dose uniformity. The distributions of FP and [18F]FP across particle size in such preparations were measured with an Andersen cascade impactor. This procedure was shown to provide an emitted dose from a [18F]FP pMDI of 246±19 μg/per metered dose. The particle size distribution as measured by mass median aerodynamic diameter (MMAD) (The mass median aerodynamic diameter (MMAD) and the geometric standard deviation (GSD) for each distribution were calculated. MMAD is defined as the aerodynamic diameter around which the mass of particles is equally distributed and the GSD is a measure of the dispersion of these particle diameters around the MMAD) from a commercial Flixotide™ pMDI was 2.6±0.2 μm and agreed well with that from an [18F]FP pMDI (2.8±0.1 μm). The MMAD and geometric standard deviation (GSD) of newly formulated [18F]FP pMDIs were unaffected by the formulation procedure. [18F]FP was distributed with good uniformity with respect to the mass of FP for particles greater than 0.43 μm. Hence, the radiolabeled pMDI is a suitable source of radiotracer for the regional measurement of lung deposition for inhaled FP in human subjects with PET. Copyright © 2003 John Wiley & Sons, Ltd.
A 11C‐Methyl stannane (5‐[11C]methyl‐1‐aza‐5‐stanna‐bicyclo[3.3.3]undecane) for use in palladium‐mediated [11C]C–C bond forming reactions with organohalides
Authors: Forngren Tobias , Samuelsson Linda , Långström Bengt 
Published: January 2004

AbstractThe synthesis of a 11C‐labelled methyl stannane, (5‐[11C]methyl‐1‐aza‐5‐stanna‐bicyclo[3.3.3]undecane (2)), and its use in palladium‐mediated Stille reactions to form [11C]C–C bonds are described. Stannane 2 was synthesized from iodo[11C]methane, 5‐chloro‐1‐aza‐5‐stanna‐bicyclo[3.3.3]undecane 1 and butyl lithium in 20–90% decay‐corrected radiochemical yield starting from iodo[11C]methane. Subsequent reaction with a series of substituted aryl and vinyl halides produced the corresponding [11C]methylated products 3–5 in up to 90% decay‐corrected radiochemical yield from the crude 2. The total synthesis time, including purification, was 25–30 min from end of radionuclide production. Copyright © 2003 John Wiley & Sons, Ltd.
Microwave accelerated 68Ga‐labelling of oligonucleotides
Authors: Velikyan I. , Lendvai G. , Välilä M. , Roivainen A. , Yngve U. , Bergström M. , Långström B. 
Published: January 2004

AbstractOligonucleotides are extensively used for characterization of gene expression in vitro and have now been studied as inhibitors of gene expression in vivo in various diseases. Labelled antisense oligonucleotides are therefore of potential interest for possible in vivo imaging of gene expression, considering the biology of tumors and applications in designing novel molecule‐targeted therapies. In the present work a method of microwave accelerated 68Ga‐labelling of oligonucleotides and analysis of the resulting tracers are described.Four modified and functionalized 17‐mer oligonucleotides with a hexylamine group in the 3′‐ or 5′‐position were studied. The oligonucleotides were conjugated to the bifunctional chelator, 1,4,7,10‐tetraazacyclododecane‐1,4,7,10‐tetraacetic acid (DOTA), and then labelled with 68Ga(T1/2=68 min) using microwave activation. The isolated decay‐corrected radiochemical yields ranged from 30 to 52%. Labelled products were stable in water and ethanol for more than 4 h. The impact of the labelling procedure on the oligonucleotide probes was investigated using hybridization to a complementary 17‐mer sense oligonucleotide in solution. Chemical modification did not influence either the labelling or hybridization ability of the oligonucleotides. The radiolabelled oligonucleotides will be used for the further in vitro and in vivo biology studies. Copyright © 2003 John Wiley & Sons, Ltd.