bluuebunny/crossref_metadata_2025_split huggingface dataset:
Two Distinct Domains in Drosophila melanogaster Telomeres
Authors: Biessmann Harald , Prasad Sudha , Semeshin Valery F , Andreyeva Eugenia N , Nguyen Quang , Walter Marika F , Mason James M 
Published: September 2005

Abstract
Telomeres are generally considered heterochromatic. On the basis of DNA composition, the telomeric region of Drosophila melanogaster contains two distinct subdomains: a subtelomeric region of repetitive DNA, termed TAS, and a terminal array of retrotransposons, which perform the elongation function instead of telomerase. We have identified several P-element insertions into this retrotransposon array and compared expression levels of transgenes with similar integrations into TAS and euchromatic regions. In contrast to insertions in TAS, which are silenced, reporter genes in the terminal HeT-A, TAHRE, or TART retroelements did not exhibit repressed expression in comparison with the same transgene construct in euchromatin. These data, in combination with cytological studies, provide evidence that the subtelomeric TAS region exhibits features resembling heterochromatin, while the terminal retrotransposon array exhibits euchromatic characteristics.
Complexities of Chromosome Landing in a Highly Duplicated Genome: Toward Map-Based Cloning of a Gene Controlling Blackleg Resistance in Brassica napus
Authors: Mayerhofer Reinhold , Wilde Kris , Mayerhofer Marion , Lydiate Derek , Bansal Vipan K , Good Allen G , Parkin Isobel A P 
Published: September 2005

Abstract
The LmR1 locus, which controls seedling resistance to the blackleg fungus Leptosphaeria maculans in the Brassica napus cultivar Shiralee, was positioned on linkage group N7. Fine genetic mapping in a population of 2500 backcross lines identified three molecular markers that cosegregated with LmR1. Additional linkage mapping in a second population colocalized a seedling resistance gene, ClmR1, from the cultivar Cresor to the same genetic interval on N7 as LmR1. Both genes were located in a region that showed extensive inter- and intragenomic duplications as well as intrachromosomal tandem duplications. The tandem duplications seem to have occurred in the Brassica lineage before the divergence of B. rapa and B. oleracea but after the separation of Brassica and Arabidopsis from a common ancestor. Microsynteny was found between the region on N7 carrying the resistance gene and the end of Arabidopsis chromosome 1, interrupted by a single inversion close to the resistance locus. The collinear region in Arabidopsis was assayed for the presence of possible candidate genes for blackleg resistance. These data provided novel insights into the genomic structure and evolution of plant resistance loci and an evaluation of the candidate gene approach using comparative mapping with a model organism.
Mutations in the Drosophila Orthologs of the F-Actin Capping Protein α- and β-Subunits Cause Actin Accumulation and Subsequent Retinal Degeneration
Authors: Delalle Ivana , Pfleger Cathie M , Buff Eugene , Lueras Paula , Hariharan Iswar K 
Published: September 2005

Abstract
The progression of several human neurodegenerative diseases is characterized by the appearance of intracellular inclusions or cytoskeletal abnormalities. An important question is whether these abnormalities actually contribute to the degenerative process or whether they are merely manifestations of cells that are already destined for degeneration. We have conducted a large screen in Drosophila for mutations that alter the growth or differentiation of cells during eye development. We have used mitotic recombination to generate patches of homozygous mutant cells. In our entire screen, mutations in only two different loci, burned (bnd) and scorched (scrd), resulted in eyes in which the mutant patches appeared black and the mutant tissue appeared to have undergone degeneration. In larval imaginal discs, growth and cell fate specification occur normally in mutant cells, but there is an accumulation of F-actin. Mutant cells degenerate much later during the pupal phase of development. burned mutations are allelic to mutations in the previously described cpb locus that encodes the β-subunit of the F-actin capping protein, while scorched mutations disrupt the gene encoding its α-subunit (cpa). The α/β-heterodimer caps the barbed ends of an actin filament and restricts its growth. In its absence, cells progressively accumulate actin filaments and eventually die. A possible role for their human orthologs in neurodegenerative disease merits further investigation.
Mutations in Mre11 Phosphoesterase Motif I That Impair Saccharomyces cerevisiae Mre11-Rad50-Xrs2 Complex Stability in Addition to Nuclease Activity
Authors: Krogh Berit O , Llorente Bertrand , Lam Alicia , Symington Lorraine S 
Published: September 2005

Abstract
The Mre11-Rad50-Xrs2 complex is involved in DNA double-strand break repair, telomere maintenance, and the intra-S phase checkpoint. The Mre11 subunit has nuclease activity in vitro, but the role of the nuclease in DNA repair and telomere maintenance remains controversial. We generated six mre11 alleles with substitutions of conserved residues within the Mre11-phosphoesterase motifs and compared the phenotypes conferred, as well as exonuclease activity and complex formation, by the mutant proteins. Substitutions of Asp16 conferred the most severe DNA repair and telomere length defects. Interactions between Mre11-D16A or Mre11-D16N and Rad50 or Xrs2 were severely compromised, whereas the mre11 alleles with greater DNA repair proficiency also exhibited stable complex formation. At all of the targeted residues, alanine substitution resulted in a more severe defect in DNA repair compared to the more conservative asparagine substitutions, but all of the mutant proteins exhibited &lt;2% of the exonuclease activity observed for wild-type Mre11. Our results show that the structural integrity of the Mre11-Rad50-Xrs2 complex is more important than the catalytic activity of the Mre11 nuclease for the overall functions of the complex in vegetative cells.
A Crossover, Randomized, Controlled Trial of Dornase Alfa Before Versus After Physiotherapy in Cystic Fibrosis
Authors: Fitzgerald Dominic A. , Hilton Jodi , Jepson Beverly , Smith Lucia 
Published: September 2005

Objective. Although dornase alfa is a widely used, aerosolized, mucolytic agent in patients with cystic fibrosis (CF), its efficacy in relation to the timing of physiotherapy has not been tested. We sought to determine whether dornase alfa is more efficacious when it is administered 30 minutes before versus 30 minutes after physiotherapy/positive expiratory pressure (PEP) therapy in clinically stable children.
Methods. Using a crossover, randomized, double-blind, and placebo-controlled trial, we undertook a 6-week study of the efficacy of dornase alfa in relation to the timing of physiotherapy at home. There were 2 treatment orders. Dornase alfa before + placebo after physiotherapy/PEP for 2 weeks was followed by a 2-week washout and then the reverse order placebo before and dornase alfa after physiotherapy/PEP for the final 2 weeks. The second treatment order reversed the placebo and dornase alfa therapy for the first and last 2-week blocks. The main outcome measures used included the change in predicted percentage of forced expiratory volume in 1 second (FEV1), a composite quality of well-being score (QWB), and a measure of aerobic fitness (maximal oxygen consumption, [VO2max]), determined using shuttle testing.
Results. Fifty-two patients who had CF (27 female) with mild to moderate suppurative lung disease, were a mean ± SD age of 10.7 ± 3.2 years, had Shwachman scores of 86 ± 11.8, had predicted FEV1 of 83% ± 18%, had quality of well-being score of 0.76 ± 0.08, and had VO2max of 42.6 ± 6.3 ml/kg per min were enrolled. Fifty patients completed the study. Intention-to-treat analysis was used. Nonsignificant mean (95% confidence interval) differences in FEV1 (0.02 L [−0.05 to 0.10]), VO2max (−0.75 ml/kg per min [−1.85 to 0.35]), and QWB (0.005 [−0.94 to 0.0028]) for dornase alfa after physiotherapy/PEP were detected. A post hoc analysis showed that patients who were colonized persistently with Pseudomonas aeruginosa had a significantly greater improvement in FEV1 (0.12 L [0.23 to 0.01] vs −0.04 L [0.05 to −0.13]) when dornase alfa was administered after physiotherapy/PEP.
Conclusions. Dornase alfa is equally efficacious when delivered before or after physiotherapy/PEP in patients with CF. Patients who are colonized persistently with P aeruginosa may derive more improvement in FEV1 when dornase alfa is delivered after physiotherapy/PEP.
A Novel Human Artificial Chromosome Vector Provides Effective Cell Lineage–Specific Transgene Expression in Human Mesenchymal Stem Cells
Authors: Ren Xianying , Katoh Motonobu , Hoshiya Hidetoshi , Kurimasa Akihiro , Inoue Toshiaki , Ayabe Fumiaki , Shibata Kotaro , Toguchida Junya , Oshimura Mitsuo 
Published: September 2005

Abstract
Mesenchymal stem cells (MSCs) hold promise for use in adult stem cell–mediated gene therapy. One of the major aims of stem cell–mediated gene therapy is to develop vectors that will allow appropriate levels of expression of therapeutic genes along differentiation under physiological regulation of the specialized cells. Human artificial chromosomes (HACs) are stably maintained as independent chromosomes in host cells and should be free from potential insertional mutagenesis problems of conventional transgenes. Therefore, HACs have been proposed as alternative implements to cell-mediated gene therapy. Previously, we constructed a novel HAC, termed 21 Δpq HAC, with a loxP site in which circular DNA can be reproducibly inserted by the Cre/loxP system. We here assessed the feasibility of lineage-specific transgene expression by the 21Δpq HAC vector using an in vitro differentiation system with an MSC cell line, hiMSCs, which has potential for osteogenic, chondrogenic, and adipogenic differentiation. An enhanced green fluorescent protein (EGFP) gene driven by a promoter for osteogenic lineage-specific osteopontin (OPN) gene was inserted onto the 21 Δpq HAC and then transferred into hiMSC. The expression cassette was flanked by the chicken HS4 insulators to block promoter interference from adjacent drug-resistant genes. The EGFP gene was specifically expressed in the hiMSC that differentiated into osteocytes in coordination with the transcription of endogenous OPN gene but was not expressed after adipogenic differentiation induction or in noninduction culture. These results suggest that use of the HAC vector is suitable for regulated expression of transgenes in stem cell–mediated gene therapy.
Blood Monocytes Mimic Endothelial Progenitor Cells
Authors: Rohde Eva , Malischnik Christina , Thaler Daniela , Maierhofer Theresa , Linkesch Werner , Lanzer Gerhard , Guelly Christian , Strunk Dirk 
Published: September 2005

AbstractThe generation of endothelial progenitor cells (EPCs) from blood monocytes has been propagated as a novel approach in the diagnosis and treatment of cardiovascular diseases. Low-density lipoprotein (LDL) uptake and lectin binding together with endothelial marker expression are commonly used to define these EPCs. Considerable controversy exists regarding their nature, in particular, because myelomonocytic cells share several properties with endothelial cells (ECs). This study was performed to elucidate whether the commonly used endothelial marker determination is sufficient to distinguish supposed EPCs from monocytes. We measured endothelial, hematopoietic, and progenitor cell marker expression of monocytes before and after angiogenic culture by fluorescence microscopy, flow cytometry, and real-time reverse transcription–polymerase chain reaction. The function of primary monocytes and monocyte-derived supposed EPCs was investigated during vascular network formation and EC colony-forming unit (CFU-EC) development. Monocytes cultured for 4 to 6 days under angiogenic conditions lost CD14/CD45 and displayed a commonly accepted EPC phenotype, including LDL uptake and lectin binding, CD31/CD105/CD144 reactivity, and formation of cord-like structures. Strikingly, primary monocytes already expressed most tested endothelial genes and proteins at even higher levels than their supposed EPC progeny. Neither fresh nor cultured monocytes formed vascular networks, but CFU-EC formation was strictly dependent on monocyte presence. LDL uptake, lectin binding, and CD31/CD105/CD144 expression are inherent features of monocytes, making them phenotypically indistinguishable from putative EPCs. Consequently, monocytes and their progeny can phenotypically mimic EPCs in various experimental models.
Role of Transcription Factors in Motoneuron Differentiation of Adult Human Olfactory Neuroepithelial-Derived Progenitors
Authors: Zhang Xiaodong , Cai Jun , Klueber Kathleen M. , Guo Zhanfang , Lu Chengliang , Winstead Welby I. , Qiu Mengsheng , Roisen Fred J. 
Published: September 2005

Abstract
Neurosphereforming cell (NSFC) lines have been established from cultures of human adult olfactory neuroepithelium. Few of these cells ever express mature neuronal or glial markers in minimal essential medium supplemented with 10% fetal bovine serum or defined medium. However, these neural progenitors have the potential to differentiate along glial or neuronal lineages. To evaluate the potential of NSFCs to form motoneurons, transcription factors Olig2, Ngn2, and HB9 were introduced into NSFCs to determine if their expression is sufficient for motoneuron specification and differentiation, as has been shown in the early development of the avian and murine central nervous systems in vivo. NSFCs transfected with Olig2, Ngn2, and HB9 alone exhibited no phenotypic lineage restriction. In contrast, simultaneous transfection of Ngn2 and HB9 cDNA increased the expression of Isl1/2, a motoneuron marker, when the cells were maintained in medium supplemented with retinoic acid, forskolin, and sonic hedgehog. Furthermore, a population of Olig2-expressing NSFCs also expressed Ngn2. Cotransfection of NSFCs with Olig2 and HB9, but not Olig2 and Ngn2, increased Isl1/2 expression. Coculture of NSFCs trans-fected with Ngn2-HB92 or Olig2 and HB9 with purified chicken skeletal muscle demonstrated frequent contacts that resembled neuromuscular junctions. These studies demonstrate that transcription factors governing the early development of chick and mouse motoneuron formation are able to drive human adult olfactory neuroepithelial progenitors to differentiate into motoneurons in vitro. Our long-term goal is to develop cell populations for future studies of the therapeutic utility of these olfactory-derived NSFCs for autologous cell replacement strategies for central nervous system trauma and neurodegenerative diseases.
A Precursor‐Based Route to ZnSe Nanowire Bundles
Authors: Xiong S. , Shen J. , Xie Q. , Gao Y. , Tang Q. , Qian Y. T. 
Published: September 2005

AbstractA large number of one‐dimensional bundles of ZnSe nanowires with diameters ranging from 15–20 nm and lengths of up to tens of micrometers have been prepared via the thermal treatment of a ribbon‐like precursor (ZnSe·3ethylenediamine), which has been synthesized by a mixed solvothermal route, in an argon atmosphere. The as‐obtained precursor has been characterized by powder X‐ray diffraction (XRD), transmission electron microscopy (TEM), IR spectroscopy, thermogravimetric analysis, and elemental analysis. XRD and high‐resolution TEM characterization reveal that the as‐synthesized ZnSe nanowires have the single‐crystal hexagonal wurtzite structure with the [001] growth direction. The surface chemical composition of ZnSe nanowires has been studied by X‐ray photoelectron spectroscopy. The cooperative action of the mixed solvents may be responsible for the formation of the morphology of the resulting products. Room‐temperature photoluminescence measurements indicate the as‐grown ZnSe nanostructures have a strong emission peak centered at 587 nm and two weak emission peaks centered at 435 and 462 nm. The strong emission from the ZnSe nanostructures reveals their potential as building blocks for optoelectronic devices.
Electrochemical Synthesis of Optically Active Polyaniline Films
Authors: Li W. , Wang H.‐L. 
Published: September 2005

AbstractPolyaniline (PANI) thin films with high optical activity are prepared electrochemically on indium tin oxide (ITO) substrates by polymerizing aniline in the presence of aniline oligomers and optically active camphor sulfonic acid (CSA). These optimized PANI chiral thin films have an anisotropic factor of 0.03 and an estimated molar ellipticity of 8.8 × 105 deg cm2 dmol–1, ∼ 25 % higher than our previously synthesized chiral PANI nanofibers that were prepared using the chemical method. The thin film prepared without aniline oligomers is basically achiral. The electrochemical method does not require an oxidizing agent and allows control of the rate of polymerization reaction by varying the oxidation potential. The electrochemical polymerization also ensures that the initiation occurs solely with the oligomers. Varying the experimental parameters, such as oxidation potential and the choice of oligomers, allows tuning of optical activity, adsorption properties, crystallinity, and morphology of the PANI thin films.
Cover Picture: Crosslinked Nanoparticle Stripes and Hexagonal Networks Obtained via Selective Patterning of Block Copolymer Thin Films (Adv. Mater. 18/2005)
Authors: Shenhar R. , Jeoung E. , Srivastava S. , Norsten T. B. , Rotello V. M. 
Published: September 2005

AbstractThe construction and fixation of ordered nanoparticle arrays allow not only the exploitation of the array's collective physical properties but also the possibility of manipulating discrete aggregates within a larger‐scale assembly scheme. A simple approach utilizing block copolymer thin films as templates and coordination chemistry as a mild crosslinking mechanism is reported by Shenhar, Rotello, and co‐workers on p. 2206. The cover image (by Nicholas Fischer) shows terpyridine‐functionalized gold nanoparticles organized in stripes on top of a microphase‐separated thin film of polystyrene‐block‐poly(methyl methacrylate) and crosslinked thorough the formation of iron–bisterpyridine complexes.
Two‐scale continuum model for simulation of wormholes in carbonate acidization
Authors: Panga Mohan K. R. , Ziauddin Murtaza , Balakotaiah Vemuri 
Published: September 2005

AbstractA two‐scale continuum model is developed to describe transport and reaction mechanisms in reactive dissolution of a porous medium, and used to study wormhole formation during acid stimulation of carbonate cores. The model accounts for pore level physics by coupling local pore‐scale phenomena to macroscopic variables (Darcy velocity, pressure and reactant cup‐mixing concentration) through structure‐property relationships (permeability‐porosity, average pore size‐porosity, and so on), and the dependence of mass transfer and dispersion coefficients on evolving pore scale variables (average pore size and local Reynolds and Schmidt numbers). The gradients in concentration at the pore level caused by flow, species diffusion and chemical reaction are described using two concentration variables and a local mass‐transfer coefficient. Numerical simulations of the model on a two‐dimensional (2‐D) domain show that the model captures the different types of dissolution patterns observed in the experiments. A qualitative criterion for wormhole formation is developed and it is given by Λ ∼ O(1), where Λ =
. Here, keff is the effective volumetric dissolution rate constant, DeT is the transverse dispersion coefficient, and uo is the injection velocity. The model is used to examine the influence of the level of dispersion, the heterogeneities present in the core, reaction kinetics and mass transfer on wormhole formation. The model predictions are favorably compared to laboratory data. © 2005 American Institute of Chemical Engineers AIChE J, 2005
A general method of computing the derivative of experimental data
Authors: Lubansky A. S. , Yeow Y. Leong , Leong Yee‐Kwong , Wickramasinghe S. Ranil , Han Binbing 
Published: September 2005

AbstractMany scientific and engineering investigations require the extraction of the first derivative from experimental data. Direct numerical differentiation is usually impractical because this amplifies the noise in the data, leading to unreliable results. This investigation shows that the problem of differentiating experimental data can be converted into one of solving an integral equation of the first kind. Tikhonov regularization is used to solve this integral equation, leading to a smooth first derivative. By using the built‐in regularization parameter in the method noise amplification is kept under control. The performance of this method is demonstrated by applying it to data taken from the literature. © 2005 American Institute of Chemical Engineers AIChE J, 2006
Mosaic trisomy 9 syndrome with unusual phenotype
Authors: Kaminker Catalina P. , Daín Liliana , Lamas María A. , Sánchez José M. , Opitz John M. , Reynolds James F. 
Published: September 2005

AbstractWe report on a newborn infant with mosaic trisomy 9. The patient shared only a few anomalies with the previously reported cases of this chromosome abnormality but had a severe craniofacial malformation not yet reported in this syndrome.
Creatine‐Kinase and pyruvate‐kinase activities in normal children: Implications in duchenne muscular dystrophy carrier detection
Authors: Passos M. R. , Gonzalez C. H. , Zatz M. , Opitz John M. , Reynolds James F. 
Published: September 2005

AbstractSerum creatine‐kinase (CK) and pyruvate‐kinase (PK) levels were determined in 201 boys and girls less than 15 years old to establish values and to investigate a possible correlation between enzyme activity, sex, and age.It was observed that the mean CK activity in boys was significantly higher than in females (of all ages), whereas it did not differ statistically between girls and women. A slight but significant correlation between CK activity and age was found only in females. The mean PK activity in children was significantly greater than in adult women and it decreased significantly with age in children of both sexes. Furthermore, a slight correlation between CK and PK was observed only in girls.Based on these results, we suggest that the results of CK and PK determinations of females at risk for Duchenne muscular dystrophy should be compared with controls of comparable age and sex.
The Okihiro syndrome of duane anomaly, radial ray abnormalities, and deafness
Authors: Hayes Ailish , Costa Teresa , Polomeno Robert C. , Opitz John M. , Reynolds James F. 
Published: September 2005

AbstractWe report on a child with Duane anomaly, deafness, cervical spine, and radial ray abnormalities. A sister of the proposita had hemifacial microsomia, cervical abnormalities, and hypoplasia of the thenar eminence. Four relatives had hypoplasia of the thenar eminence. A fifth had preaxial polydactyly. Duane anomaly was present in two sixth‐degree relatives. This appears to be an autosomal dominant trait. Singly or in combination the abnormalities seen in this family have all been described in association with Duane anomaly. Their occurrence in the same family suggests that they are not independent entities but represent pleiotropic effects of the same gene.