bluuebunny/crossref_metadata_2025_split huggingface dataset:
Involvement of CSF‐1 in generating a stroma‐independent hematopoietic stem cell line
Authors: Heberlein Christoph , Friel Jutta , Itoh Katsuhiko , Medlock Eugene , Li Luke , Nakayama Naoki , Stocking Carol , Geldmacher Maren , Ostertag Wolfram 
Published: October 2005

AbstractThe hematopoietic stem cell line, Myl‐D7, is maintained by a self‐renewing stem cell population that spontaneously generates myeloid, lymphoid, and erythroid progeny. MS‐5 stromal cells are necessary for the growth of Myl‐D7 cells. One component of the Myl‐D7 cells proliferation activity released by MS‐5 stromal cells was enriched by Q sepharose fractionation and shown to be colony stimulating factor‐1 (CSF‐1) by Western blotting, BAC1.2F5 cell bioassay and inhibition of Myl‐D7 proliferation by CSF‐1 antibody. The requirement of Myl‐D7 cells for CSF‐1 was also demonstrated independently by selecting for rare, stroma‐independent Myl‐D7 mutant clones able to grow without stroma and additional factors. Eighty‐nine stroma‐independent mutant clones were obtained and belonged to two classes. The majority of mutants did not secrete any growth promoting activity. The second, rarer class of mutants releases a factor that stimulates proliferation/survival for up to several months and approximately half of the secretors express high levels of CSF‐1 mRNA. Wild type Myl‐D7 grown with supernatants from the secretor cells retained the stem cell phenotype. These data suggest that CSF‐1 may act as a key factor in stroma‐regulated hematopoiesis and cell–cell interaction. J. Cell. Physiol. 206: 556–562, 2006. © 2005 Wiley‐Liss, Inc.
Multiple genetic and epigenetic interacting mechanisms contribute to clonally selection of drug‐resistant tumors: Current views and new therapeutic prospective
Authors: Roberti Annalisa , Sala Dario La , Cinti Caterina 
Published: October 2005

AbstractSuccessful treatment of cancer requires a clear understanding of drug‐resistance mechanism. Cancer patient are often treated with standard protocols without considering individual difference in chemosensitivity, whereas the efficacy of anticancer drug varies widely among individual patients. Since chemosensitivity involves multiple interacting factors, it is not sufficient to investigate a single gene or factor to fix chemoresistance. Along with affecting disease progression, the synergism between genetic and epigenetic abnormalities can contribute to convert a sensible tumor cell in a resistant one. Unlike genetic changes, epigenetic changes are potentially reversible. Therefore, treatment with DNA methylation inhibitors can reactivate the expression of genes improperly methylated and can reverse many aspect of cancer phenotype such as drug resistance. The demethylating agents are used in the treatment of several kind of tumor, but toxicity and the potential outcome on the normal methylation patterns have always been concern of researchers and clinicals. It is necessary to create individual chemosensitivity–chemoresistance maps in order to identify the combination of drugs for optimized treatments. An overview on genetic and epigenetic events contributing to clonally selection of chemotherapeutic‐resistant tumors is discussed. J. Cell. Physiol. © 2005 Wiley‐Liss, Inc.
Expression of the mechanosensitive 2PK+ channel TREK‐1 in human osteoblasts
Authors: Hughes Steven , Magnay Julia , Foreman Megan , Publicover Stephen J. , Dobson Jon P. , El Haj Alicia J. 
Published: October 2005

AbstractTREK‐1 is a mechanosensitive member of the two‐pore domain potassium channel family (2PK+) that is also sensitive to lipids, free fatty acids (including arachidonic acid), temperature, intracellular pH, and a range of clinically relevant compounds including volatile anaesthetics. TREK‐1 is known to be expressed at high levels in excitable tissues, such as the nervous system, the heart and smooth muscle, where it is believed to play a prominent role in controlling resting cell membrane potential and electrical excitability. In this report, we use RT‐PCR, Western blotting and immunohistochemistry to confirm that human derived osteoblasts and MG63 cells express TREK‐1 mRNA and protein. In addition, we show gene expression of TREK2c and TRAAK channels. Furthermore, whole cell patch clamp electrophysiology demonstrates that these cells express a spontaneously active, outwardly rectifying potassium “background leak” current that shares many similarities to TREK‐1. The outward current is largely insensitive to TEA and Ba2+, and is sensitive to application of lysophosphatidylcholine (LPC). In addition, blocking TREK‐1 channel activity is shown to upregulate bone cell proliferation. It is concluded that human osteoblasts functionally express TREK‐1 and that these channels contribute, at least in part, to the resting membrane potential of human osteoblast cells. We hypothesise a possible role for TREK‐1 in mechanotransduction, leading to bone remodelling. J. Cell. Physiol. © 2005 Wiley‐Liss, Inc.
Normal and transforming functions of RUNX1: A perspective
Authors: Mikhail Fady M. , Sinha Kislay K. , Saunthararajah Yogen , Nucifora Giuseppina 
Published: October 2005

AbstractConverging studies from many investigators indicate that RUNX1 has a critical role in the correct maintenance of essential cellular functions during embryonic development and after birth. The discovery that this gene is also frequently mutated in human leukemia has increased the interest in the role that RUNX1 plays in both normal and transforming pathways. Here, we provide an overview of the many roles of RUNX1 in hematopoietic self‐renewal and differentiation and summarize the information that is currently available on the many mechanisms of RUNX1 deregulation in human leukemia. J. Cell. Physiol. © 2005 Wiley‐Liss, Inc.
Nectin‐2 expression in testicular cells is controlled via the functional cooperation between transcription factors of the Sp1, CREB, and AP‐1 families
Authors: Lui Wing‐Yee , Sze Kit‐Ling , Lee Will M. 
Published: October 2005

AbstractNectin‐2, a major protein component of the adherens junctions (AJs), is found between Sertoli cells and germ cells in the seminiferous epithelium. Recent studies have shown that the expression of nectin‐2 gene in testis is crucial to maintain normal spermatogenesis since male knockout mice lacking nectin‐2 gene are sterile and possess morphologically abnormal spermatozoa. However, the molecular mechanisms governing its basal transcription remain poorly understood. By the use of Sertoli and germ cell‐lines (TM4 and GC‐2spd(ts) cells, respectively) in transient transfection studies, we showed that the minimal mouse nectin‐2 promoter was located between nucleotides −316 and −211 (relative to the translation start site). Two putative Sp1 motifs and one each of the CRE, AP1, and AP2 motifs were identified within this region. Mutational studies showed that these two Sp1 motifs cooperated synergistically with the CRE motif, but not the AP1 and AP2 motifs, to regulate nectin‐2 gene transcription in both TM4 and GC‐2spd(ts) cells. By EMSAs, we found that an AP‐1 consensus sequence was able to inhibit DNA–protein complex formation with the CRE motif, suggesting an interaction between the AP‐1 transcription factor (c‐Jun) and CREB within the CRE motif. Overexpressions of CREB and c‐Jun, but not c‐Fos, also significantly increased the promoter activity, which suggests that CREB and c‐Jun are the crucial transcription factors involved in regulating nectin‐2 gene transcription. Chromatin immunoprecipitation assay has shown that, in vivo, CREB, c‐Jun, and Sp1 family proteins are bound to the mouse nectin‐2 promoter. Analysis of the staged tubules has confirmed that the cyclic expressions of CREB and nectin‐2 coincide with the event of adherens junction restructuring between Sertoli cells and germ cells. The cross‐talk between CREB, c‐Jun, and Sp1 family protein is believed to be a major transcription machinery to drive nectin‐2 expression in Sertoli cells. J. Cell. Physiol. 207: 144–157, 2006. © 2005 Wiley‐Liss, Inc.
A two‐step supercritical fluid extraction of polycyclic aromatic hydrocarbons from roadside soil samples
Authors: Lojková Lea , Sedláková Jitka , Kubáň Vlastimil 
Published: October 2005

AbstractA two‐step procedure for the supercritical fluid extraction (SFE) of polycyclic aromatic hydrocarbons from soil samples was developed. The procedure consists of a static supercritical fluid treatment in a closed extraction cell at a high temperature (T = 250 or 340°C for 20 min) and an SFE with a solvent trapping. During the static phase, the sample is exposed to a supercritical organic solvent (methanol, toluene, dichloromethane, ACN, acetone, and hexane). The solvent penetrates particles of the matrix to substitute strongly bonded molecules and dissolves the analytes in the supercritical phase. At ambient temperature, supercritical fluids became liquid and lost their solvation abilities. Most of the analytes condense on the surface of the particles or on the extraction cell walls without forming strong bonds or penetrating deep into the matrix. Thus, the pretreatment liberates the analytes and they behave similar to those in freshly spiked samples. The common SFE with toluene‐modified CO2 as an extraction fluid follows the static phase. With the use of the most suitable extraction phases (toluene, ACN), the extraction efficiency of the combined procedure is much higher (∼︁100%). The results of the combined procedure are compared to the SFE procedure of the same untreated sample (difference less than 5%) and to the Soxhlet extraction. The extracts were analyzed using a GC with the flame ionization detection.
Liquid chromatography of polymers under limiting conditions of adsorption: III. Role of experimental variables
Authors: Šnauko Marián , Berek Dušan 
Published: October 2005

AbstractLC of polymers under limiting conditions of adsorption (LC LCA) is a novel method based on different mobility of (pore excluded) macromolecules compared to (pore permeating) solvent molecules. Polymer sample is injected in a solvent preventing its adsorption within the column. Eluent promotes sample adsorption. Under these conditions, macromolecules cannot leave its initial solvent and elute from the column independently of their molar mass. In contrast, a less interactive simultaneously injected polymer leaves its initial solvent zone and is eluted in the size exclusion mode. As a result, chemically different polymer species can be discriminated. The effect of selected experimental conditions was studied on the LC LCA behavior of poly(methyl methacrylate)s eluted from bare silica gel columns. The parameters were packing pore diameter, injected sample volume and concentration, as well as column temperature. The size independent elution was only little affected by the above parameters and LC LCA produced well‐focused peaks. The LC LCA mechanism was operative even at a very large sample of both volume and concentration. This makes LC LCA a robust and user‐friendly method, likely suitable also for characterization of minor components of polymer mixtures.
Electrochemical preparation of composite polyaniline coating and its application in the determination of bisphenol A, 4‐n‐nonylphenol, 4‐tert‐octylphenol using direct solid phase microextraction coupled with high performance liquid chromatography
Authors: Huang Minjia , Jiang Guibin , Cai Yaqi 
Published: October 2005

AbstractFor SPME‐HPLC, metal wires with better mechanical strength are preferred over the fused silica fibers. In this article, a novel composite polyaniline (CPANI) doped with PEG and polydimethylsiloxane coating (CPANI fiber) was prepared on a stainless steel wire by a three‐electrode system: the fiber was used as the work electrode, a calomel electrode and a platinum electrode were used as the reference and the counter electrodes, respectively. To evaluate the new CPANI coating, the coating was used to extract three kinds of phenols (bisphenol A, 4‐n‐nonylphenol, and 4‐tert‐octylphenol) in water samples by direct‐SPME mode and then desorbed in commercial SPME‐HPLC interface to separation. The extraction procedure was also optimized. Five real water samples were investigated. Good recoveries were gained when environmental samples were analyzed.
Novel nonaqueous capillary electrophoresis separation and determination of bioactive flavone derivatives in Chinese herbs
Authors: Qi Shengda , Li Yuqin , Wu Shuixian , Chen Xingguo , Hu Zhide 
Published: October 2005

AbstractNonaqueous CE (NACE) coupled to UV detection is described for the separation and determination of bioactive flavone derivatives in Chinese herbs extraction. After optimization of electrophoresis parameters, including the electrolyte nature and the organic solvent composition, a reliable separation of the analytes in an ACN/methanol (60 : 40, v/v) mixture containing 80 mM Tris and 10 mM sodium cholate was performed. The detection was performed at 254 nm. Method performances, including migration time and peak area reproducibility, linearity, sensitivity, and accuracy, were evaluated. The method was applied to determine bioactive flavone derivatives in seven Chinese herbs.
Separation and determination of anthraquinones in Cassia obtusifolia (Leguminosae) by micellar electrokinetic capillary electrophoresis
Authors: Jiang Ting‐Fu , Lv Zhi‐Hua , Wang Yuan‐Hong 
Published: October 2005

AbstractAn MEKC method was developed for the determination of the five pharmaceutically important anthraquinones: chrysophanol (1), physcion (2), emodin (3), aloe‐emodinin (4), and rhein (5) in Cassia obtusifolia (Leguminosae). A buffer solution (pH 9.00) composed of 20 mM sodium borate, 20 mM sodium deoxycholate (DOC), and 15% ACN was found to be the most suitable electrolyte for this separation. Regression equations revealed linear relationships (correlation coefficients: 0.9993, 0.9992, 0.9996, 0.9989, and 0.9991) between the peak area of each compound (1, 2, 3, 4, and 5) and its concentration. The RSDs of migration times and peak areas were <1.23 and 2.72% within 1 day, respectively. The effects of pH value, surfactant (DOC) concentration, and organic modifier on the migration were also studied. By this way, the contents of five anthraquinones in the extracts of the seed of C. obtusifolia (Leguminosae) from different sources were successfully determined within 14 min.
Characterization of N‐ and O‐glycopeptides of recombinant human erythropoietins as potential biomarkers for doping analysis by means of microscale sample purification combined with MALDI‐TOF and quadrupole IT/RTOF mass spectrometry
Authors: Stübiger Gerald , Marchetti Martina , Nagano Marietta , Grimm Rudolf , Gmeiner Günter , Reichel Christian , Allmaier Günter 
Published: October 2005

AbstractSee original 2005, vol. 28, issue 14, pp. 1764–1778. DOI 10.1002/jssc.200500148
The influence of some steric and electron effects on the mechanism of aromatic nucleophilic substitution (SNAr) reactions in nonpolar solvent
Authors: Emokpae Thomas A. , Atasie Nkechi V. 
Published: October 2005

AbstractKinetic studies are reported for the reactions with aniline in benzene of a series of X‐phenyl 2,4,6‐trinitrophenyl ethers [X = H; 2‐, 3‐, 4‐CH3; 2,4‐, or 2,6‐(CH3)2] a–f, and the results compared with those of the corresponding nitro derivatives. In the methyl series, kinetic data show that increasing substitution reduces drastically the rates of reactions indicative of the operation of some kind of steric effect. The unfavorable steric congestion at the reaction center appears to be unimportant in determining the kinetic order of the reactions. In general, the second‐order rate constants kA depend linearly on the square of nucleophile concentration. The change in the kinetic form observed in the nitro derivatives may be largely due to the electron‐withdrawing effect of the group. With the 2,6‐dinitro derivative, however, the uncatalyzed pathway k2 takes all the reaction flux. Steric hindrance to intermolecular proton transfer from base to the ethereal oxygen of the intermediate is sufficient to make the base‐catalyzed pathway insignificant relative to the k2 pathway. © 2005 Wiley Periodicals, Inc. Int J Chem Kinet 37: 744–750, 2005
Kinetics and mechanism of oxidation of iodide with a (μ‐oxo)diiron(III,III) complex in weakly acidic media
Authors: Mukherjee Ritam , Dhar Basab Bijayi , Banerjee Rupendranath 
Published: October 2005

AbstractThe complex ion [FeIII2(μ‐O)(phen)4(H2O)2]4+ (1) (phen = 1,10‐phenanthroline) and its hydrolytic derivatives [FeIII2(μ‐O)(phen)4(H2O)(OH)]3+ (1a) and [FeIII2(μ‐O)(phen)4‐ (OH)2]2+ (2a) coexist in rapid equilibria in the range pH 4.23–5.35 in the presence of excess phenanthroline (pKa1 = 3.71±0.03, pKa2 = 5.28± 0.07). The solution reacts quantitatively with I− to produce [Fe(phen)3]2+ and I2. Only 1 but none of its hydrolytic derivatives is kinetically active. Both inner and outer sphere pathways operate. The observed rate constants show second‐order dependence on the concentration of iodide, while the dependence on [H+] is complex in nature. Added Cl− inhibits the formation of adduct with I− and thus retards the rate of inner sphere path, leading to a rate saturation at high [Cl−], where only the outer sphere mechanism is active. Kinetic data indicate that simultaneous presence of two I− in the vicinity of diiron core is necessary for the reduction of 1. © 2005 Wiley Periodicals, Inc. Int J Chem Kinet 37: 737–743, 2005
Quantum yield for hydrogen atom formation from H2O2 photolysis in the range 193–240 nm
Authors: Nakayama Tomoki , Takahashi Kenshi , Matsumi Yutaka 
Published: October 2005

AbstractPhotodissociation processes of H2O2 in the range 193–240 nm have been studied by pulsed laser photolysis and laser‐induced fluorescence detection of H atom fragments at 121.56 nm. The quantum yield values for H atom formation at 295 ± 2 K have been determined to be 0.20 ± 0.03, 0.038 ± 0.008, 0.029 ± 0.003, 0.015 ± 0.006, 0.007 ± 0.002 at 193, 207, 210, 220, and 230 nm, respectively. At 240 nm, only the upper limit value of <0.002 has been obtained. © 2005 Wiley Periodicals, Inc. Int J Chem Kinet 37: 751–754, 2005
Gas‐phase reaction of dichlorvos, carbaryl, chlordimeform, and 2,4‐D butyl ester with OH radicals
Authors: Sun F. , Zhu T. , Shang J. , Han L. 
Published: October 2005

AbstractWidespread use of pesticides has caused serious environmental concern. In order to evaluate the fate of organic pesticides in the atmosphere, rate constants for gas phase reactions of OH radicals with dichlorvos, carbaryl, chlordimeform, and 2,4‐D butyl ester were measured using the relative rate method at ambient temperature and 101 kPa total pressure. On‐line FTIR spectroscopy was used to monitor the concentrations of pesticides as a function of time. The reaction rate constants with OH radicals (in units of cm3 molecule−1 s−1) have been determined as (2.0 ± 0.4) ×  10−11 for dichlorvos, (3.3 ± 0.5) ×  10−11 for carbaryl, (3.0 ± 0.7) ×  10−10 for chlordimeform, and (1.5 ± 0.2) ×  10−11 for 2,4‐D butyl ester. These rate constants agree well with those estimated based on the structure–activity relationship. The group rate constant for NC group (k(NC)) was estimated as 2.7 × 10−10 cm3 molecule−1 s−1. Dimethyl phosphite has been tentatively identified as a product of the reaction of dichlorvos with OH radicals. Atmospheric lifetimes due to the reactions with OH radicals were also estimated (in units of h): 14 ± 3 for dichlorvos, 8 ± 1 for carbaryl, 1.0 ± 0.3 for chlordimeform, and 19 ± 3 for 2,4‐D butyl ester. These short atmospheric lifetimes indicate that the four organic pesticides degrade rapidly in the atmosphere, and they themselves are unlikely to cause persistent pollution. Further studies are needed to identify the potential hazard of their degradation products. © 2005 Wiley Periodicals, Inc. Int J Chem Kinet 37: 755–762, 2005
Photophysics and kinetics of naphthopyran derivatives, part 2: Analysis of diarylnaphthopyran kinetics. Degeneracy of the kinetic solution
Authors: Maafi M. , Brown R. G. 
Published: October 2005

AbstractThe photocoloring and fading kinetics of the photochromic 3,3‐diphenyl‐3H‐naphtho[2,1‐b]pyran (NPY) have been analyzed using a kinetic treatment for three related species recently developed by us (Int J Chem Kinet 2005, 37(3), 162). The concepts of identifiability and distinguishability are developed with respect to the elucidation of the NPY kinetics. We find that neither set of kinetic data on its own, nor the two data sets combined, allow the true mechanism to be distinguished. In addition, even for a chosen mechanism, there exist degenerate sets of parameters i.e. the solutions are also unidentifiable. A discussion of the limits and uniqueness of the results' interpretation is presented. © 2005 Wiley Periodicals, Inc. Int J Chem Kinet 37: 717–727, 2005
Action fluency in Parkinson's disease: A follow‐up study
Authors: Signorini Matteo , Volpato Chiara 
Published: October 2005

AbstractThe impairment in action fluency task present in Parkinson's disease (PD) patients has been previously interpreted as an indicator of conversion from PD to PD with dementia or as a grammatical deficit for verbs and ascribed to a frontostriatal loop pathophysiology. In the present study, 20 patients with PD without dementia were longitudinally tested with overall cognitive decline scales and semantic, letter, and action fluency tasks in a 24‐month follow‐up study. In comparison with healthy age‐matched controls, PD patients showed a stable and consistent impairment on action fluency without any sign of cognitive decline. Our findings suggest that action fluency task may be an early sign of impairment of frontostriatal circuits in PD and it cannot be considered an indicator of conversion from PD to PD with dementia. © 2005 Movement Disorder Society
Movement disorders fellowship training program at Columbia University Medical Center in 2001–2002
Authors: Portera‐Cailliau Carlos , Victor Daryl , Frucht Steven , Fahn Stanley 
Published: October 2005

AbstractData regarding the clinical experience of movement disorders subspecialty training are currently not available. In order to provide information to help design a well‐rounded clinical experience, we reviewed the number and types of patients seen by all clinical movement disorders fellows over the course of 1 year at Columbia University Medical Center (CUMC). We conducted a retrospective analysis of all patients seen by four full‐time clinical fellows and one part‐time fellow during the 2001–2002 academic year, using billing records to tabulate all clinic visits and patient charts to certify diagnosis. One thousand six hundred sixty‐two patients (1,132 new and 530 follow‐ups) were seen by five fellows. Each full‐time fellow evaluated and treated a mean of 263 new patients, 116 follow‐up patients, and 15 in‐patient consultations. The part‐time clinical fellow evaluated and treated 81 new patients and 65 follow‐up patients. Approximately half of the new patients had idiopathic Parkinson's disease. Full‐time fellows saw equivalent numbers of patients but they evaluated few patients with uncommon movement disorders. Weekly video rounds allowed all fellows to see many more patients, aiding the recognition of movement phenomenology and enhancing understanding of diagnoses and treatment strategies. Thus, CUMC fellows evaluate a large number of patients with a wide range of diagnoses within a 1‐year period. Video rounds allow greater exposure to uncommon diagnoses. Similar data from other movement disorder training programs are needed to help create guidelines for formal accreditation and to improve clinical training in this subspecialty. © 2005 Movement Disorder Society