bluuebunny/crossref_metadata_2025_split huggingface dataset:
Intramolecular Cyclization of Aminoalkynes Catalyzed by PdMo3S4 Cubane Clusters
Authors: Takei Izuru , Enta Yutaka , Wakebe Youhei , Suzuki Toshiaki , Hidai Masanobu 
Published: May 2006

Abstract
PdMo3S4 cubane clusters [(Cp*Mo)3(μ3-S)4Pd(L)][PF6] (Cp* = η5-C5Me5; L = dba (2), ma (3); dba = dibenzylideneacetone, ma = maleic anhydride) showed high catalytic activity for the intramolecular hydroamination of aminoalkynes to afford the corresponding cyclic imines in good yields under mild conditions. A molecular structure of 3 has been determined by X-ray diffraction study.
Site-specific Scission of Lambda Phage Genomic DNA by Ce(IV)/EDTA-based Artificial Restriction DNA Cutter
Authors: Yamamoto Yoji , Miura Kazuyuki , Komiyama Makoto 
Published: May 2006

Abstract
Lambda phage genomic DNA (48502 base pairs) was site-selectively hydrolyzed by artificial restriction DNA cutter (ARCUT), which we have developed by combining Ce(IV)/EDTA and pseudo-complementary PNA. PNA satisfactorily invaded lambda DNA and activated the target site for the scission by Ce(IV)/EDTA.
Phenylene-bridged Polysilaalkane Macrocycles as Framed Molecular Rotor
Authors: Setaka Wataru , Sato Keisuke , Ohkubo Atsushi , Kabuto Chizuko , Kira Mitsuo 
Published: May 2006

Abstract
Using ring-closing hydrosilylation, trans- and cis-isomers of 2,5-dichrolo-1,4-phenylene-bridged macrocyclic polysila-alkanes were synthesized as molecular tops with a frame and characterized by X-ray crystallography. Dynamic 1H NMR analysis for the cis-isomers in toluene-d8 showed the internal rotation of the phenylene ring in solution.
Photocontrol of ζ-Potential of Poly(styrene) Microspheres Prepared by Soap-free Emulsion Copolymerization
Authors: Kishimoto Hiroaki , Watanabe Masaru , Iyoda Tomokazu , Nagai Katsutoshi , Nakagawa Masaru 
Published: May 2006

Abstract
Exposure to UV light at wavelengths of ≥254 nm caused poly(styrene) microspheres in deionized water to exhibit a negatively shifted ζ-potential value by generation of carboxyl groups due to photooxidation. Their ζ-potential value could be tuned simply by an exposure dose without a change in their average diameter.
Analysis of Close Stable Homolog Juxtaposition During Meiosis in Mutants ofSaccharomyces cerevisiae
Authors: Lui Doris Y , Peoples-Holst Tamara L , Chang Mell Joshua , Wu Hsin-Yen , Dean Eric W , Burgess Sean M 
Published: May 2006

AbstractA unique aspect of meiosis is the segregation of homologous chromosomes at the meiosis I division. The pairing of homologous chromosomes is a critical aspect of meiotic prophase I that aids proper disjunction at anaphase I. We have used a site-specific recombination assay in Saccharomyces cerevisiae to examine allelic interaction levels during meiosis in a series of mutants defective in recombination, chromatin structure, or intracellular movement. Red1, a component of the chromosome axis, and Mnd1, a chromosome-binding protein that facilitates interhomolog interaction, are critical for achieving high levels of allelic interaction. Homologous recombination factors (Sae2, Rdh54, Rad54, Rad55, Rad51, Sgs1) aid in varying degrees in promoting allelic interactions, while the Srs2 helicase appears to play no appreciable role. Ris1 (a SWI2/SNF2 related protein) and Dot1 (a histone methyltransferase) appear to play minor roles. Surprisingly, factors involved in microtubule-mediated intracellular movement (Tub3, Dhc1, and Mlp2) appear to play no appreciable role in homolog juxtaposition, unlike their counterparts in fission yeast. Taken together, these results support the notion that meiotic recombination plays a major role in the high levels of homolog interaction observed during budding yeast meiosis.
The Drosophila Boundary Element-Associated Factors BEAF-32A and BEAF-32B Affect Chromatin Structure
Authors: Gilbert Matthew K , Tan Yian Yee , Hart Craig M 
Published: May 2006

Abstract
Binding sites for the Drosophila boundary element-associated factors BEAF-32A and -32B are required for the insulator activity of the scs′ insulator. BEAF binds to hundreds of sites on polytene chromosomes, indicating that BEAF-utilizing insulators are an important class in Drosophila. To gain insight into the role of BEAF in flies, we designed a transgene encoding a dominant-negative form of BEAF under GAL4 UAS control. This BID protein encompasses the BEAF self-interaction domain. Evidence is provided that BID interacts with BEAF and interferes with scs′ insulator activity and that BEAF is the major target of BID in vivo. BID expression during embryogenesis is lethal, implying that BEAF is required during early development. Expression of BID in eye imaginal discs leads to a rough-eye phenotype, and this phenotype is rescued by a third copy of the BEAF gene. Expression of BID in salivary glands leads to a global disruption of polytene chromatin structure, and this disruption is largely rescued by an extra copy of BEAF. BID expression also enhances position-effect variegation (PEV) of the wm4h allele and a yellow transgene inserted into the pericentric heterochromatin of chromosome 2R, while a third copy of the BEAF gene suppresses PEV of both genes. These results support the hypothesis that BEAF-dependent insulators function by affecting chromatin structure or dynamics.
Heterochromatic Genes in Drosophila: A Comparative Analysis of Two Genes
Authors: Schulze Sandra R , McAllister Bryant F , Sinclair Donald A R , Fitzpatrick Kathleen A , Marchetti Marcella , Pimpinelli Sergio , Honda Barry M 
Published: May 2006

Abstract
Centromeric heterochromatin comprises ∼30% of the Drosophila melanogaster genome, forming a transcriptionally repressive environment that silences euchromatic genes juxtaposed nearby. Surprisingly, there are genes naturally resident in heterochromatin, which appear to require this environment for optimal activity. Here we report an evolutionary analysis of two genes, Dbp80 and RpL15, which are adjacent in proximal 3L heterochromatin of D. melanogaster. DmDbp80 is typical of previously described heterochromatic genes: large, with repetitive sequences in its many introns. In contrast, DmRpL15 is uncharacteristically small. The orthologs of these genes were examined in D. pseudoobscura and D. virilis. In situ hybridization and whole-genome assembly analysis show that these genes are adjacent, but not centromeric in the genome of D. pseudoobscura, while they are located on different chromosomal elements in D. virilis. Dbp80 gene organization differs dramatically among these species, while RpL15 structure is conserved. A bioinformatic analysis in five additional Drosophila species demonstrates active repositioning of these genes both within and between chromosomal elements. This study shows that Dbp80 and RpL15 can function in contrasting chromatin contexts on an evolutionary timescale. The complex history of these genes also provides unique insight into the dynamic nature of genome evolution.
The Drosophila Nbs Protein Functions in Multiple Pathways for the Maintenance of Genome Stability
Authors: Ciapponi Laura , Cenci Giovanni , Gatti Maurizio 
Published: May 2006

Abstract
The Mre11/Rad50/Nbs (MRN) complex and the two protein kinases ATM and ATR play critical roles in the response to DNA damage and telomere maintenance in mammalian systems. It has been previously shown that mutations in the Drosophila mre11 and rad50 genes cause both telomere fusion and chromosome breakage. Here, we have analyzed the role of the Drosophila nbs gene in telomere protection and the maintenance of chromosome integrity. Larval brain cells of nbs mutants display telomeric associations (TAs) but the frequency of these TAs is lower than in either mre11 or rad50 mutants. Consistently, Rad50 accumulates in the nuclei of wild-type cells but not in those of nbs cells, indicating that Nbs mediates transport of the Mre11/Rad50 complex in the nucleus. Moreover, epistasis analysis revealed that rad50 nbs, tefu (ATM) nbs, and mei-41 (ATR) nbs double mutants have significantly higher frequencies of TAs than either of the corresponding single mutants. This suggests that Nbs and the Mre11/Rad50 complex play partially independent roles in telomere protection and that Nbs functions in both ATR- and ATM-controlled telomere protection pathways. In contrast, analysis of chromosome breakage indicated that the three components of the MRN complex function in a single pathway for the repair of the DNA damage leading to chromosome aberrations.
Genetic Interactions Between TFIIF and TFIIS
Authors: Fish Rachel N , Ammerman Michelle L , Davie Judith K , Lu Betty F , Pham Cindy , Howe LeAnn , Ponticelli Alfred S , Kane Caroline M 
Published: May 2006

Abstract
The eukaryotic transcript elongation factor TFIIS is encoded by a nonessential gene, PPR2, in Saccharomyces cerevisiae. Disruptions of PPR2 are lethal in conjunction with a disruption in the nonessential gene TAF14/TFG3. While investigating which of the Taf14p-containing complexes may be responsible for the synthetic lethality between ppr2Δ and taf14Δ, we discovered genetic interactions between PPR2 and both TFG1 and TFG2 encoding the two larger subunits of the TFIIF complex that also contains Taf14p. Mutant alleles of tfg1 or tfg2 that render cells cold sensitive have improved growth at low temperature in the absence of TFIIS. Remarkably, the amino-terminal 130 amino acids of TFIIS, which are dispensable for the known in vitro and in vivo activities of TFIIS, are required to complement the lethality in taf14Δ ppr2Δ cells. Analyses of deletion and chimeric gene constructs of PPR2 implicate contributions by different regions of this N-terminal domain. No strong common phenotypes were identified for the ppr2Δ and taf14Δ strains, implying that the proteins are not functionally redundant. Instead, the absence of Taf14p in the cell appears to create a dependence on an undefined function of TFIIS mediated by its N-terminal region. This region of TFIIS is also at least in part responsible for the deleterious effect of TFIIS on tfg1 or tfg2 cold-sensitive cells. Together, these results suggest a physiologically relevant functional connection between TFIIS and TFIIF.
Fitness Benefits of Systemic Acquired Resistance During Hyaloperonospora parasitica Infection in Arabidopsis thaliana
Authors: Heidel Andrew J , Dong Xinnian 
Published: May 2006

Abstract
We investigated the fitness benefits of systemic acquired resistance (SAR) in Arabidopsis thaliana using a mutational and transformational genetic approach. Genetic lines were designed to differ in the genes determining resistance signaling in a common genetic background. Two mutant lines (cpr1 and cpr5) constitutively activate SAR at different points in SAR signaling, and one mutant line (npr1) has impaired SAR. The transgenic line (NPR1-H) has enhanced resistance when SAR is activated, but SAR is still inducible similarly to wild type. The fitness benefits were also investigated under two nutrient levels to test theories that preventing pathogen damage and realized resistance benefits may be affected by nutrient availability. Under low-nutrient conditions and treatment with the pathogenic oomycete, Hyaloperonospora parasitica, wild type had a higher fitness than the mutant that could not activate SAR, demonstrating that normal inducible SAR is beneficial in these conditions; this result, however, was not found under high-nutrient conditions. The mutants with constitutive SAR all failed to show a fitness benefit in comparison to wild type under a H. parasitica pathogen treatment, suggesting that SAR is induced to prevent an excessive fitness cost.
Linkage Disequilibrium on the Bovine X Chromosome: Characterization and Use in Quantitative Trait Locus Mapping
Authors: Sandor Cynthia , Farnir Frédéric , Hansoul Sarah , Coppieters Wouter , Meuwissen Théo , Georges Michel 
Published: May 2006

Abstract
We herein demonstrate that in the Holstein–Friesian dairy cattle population, microsatellites are as polymorphic on the X chromosome as on the autosomes but that the level of linkage disequilibrium between these markers is higher on the X chromosome than on the autosomes. The latter observation is not compatible with the small male-to-female ratio that prevails in this population and results in a higher gonosomal than autosomal effective population size. It suggests that the X chromosome undergoes distinct selective or mutational forces. We describe and characterize a novel Markovian approach to exploit this linkage disequilibrium to compute the probability that two chromosomes are identical-by-descent conditional on flanking marker data. We use the ensuing probabilities in a restricted maximum-likelihood approach to search for quantitative trait loci (QTL) affecting 48 traits of importance to the dairy industry and provide evidence for the presence of QTL affecting 5 of these traits on the bovine X chromosome.
Neurophysiologic Assessment of Neonatal Sleep Organization: Preliminary Results of a Randomized, Controlled Trial of Skin Contact With Preterm Infants
Authors: Ludington-Hoe Susan M. , Johnson Mark W. , Morgan Kathy , Lewis Tina , Gutman Judy , Wilson P. David , Scher Mark S. 
Published: May 2006

BACKGROUND. Sleep is important to brain organization, but few strategies to promote sleep among premature infants have been tested. Behaviorally based measures of sleep have shown increased quiet sleep (QS) and decreased active sleep (AS) during skin-to-skin contact (SSC) with the mother, but these results have not been confirmed with objective electroencephalographic/polysomnographic measures of sleep organization. Important differences exist between behavioral and electroencephalographic/polysomnographic definitions of sleep state.METHODS. Data for the first 28 relatively healthy, preterm subjects of an ongoing randomized trial of one 2- to 3-hour session of SSC or incubator care between feedings are reported here. Infants were positioned prone, inclined, and nested in an incubator during the 2- to 3-hour pretest period, were fed, and then went into the test period of SSC or incubator care. Infants were left largely undisturbed throughout testing. A mixed-model regression analysis compared the test-pretest differences in outcome measures within and between groups.RESULTS. Results showed that arousals were significantly lower in the SSC group, compared with the control group, for the entire study period and for test-pretest matched segments of QS and AS. Rapid eye movement was significantly lower for the SSC group for the study period and AS segments. Indeterminate sleep was significantly lower for the SSC group when confounding environmental variables were included in the regression analysis. When 4 subjects who experienced excessive ambient light levels during SSC were removed from analysis, QS increased during SSC.CONCLUSIONS. The patterns demonstrated by the SSC group are analogous to more-mature sleep organization. SSC may be used as an intervention to improve sleep organization in this population of preterm infants.
Inhibition of Meconium-Induced Cytokine Expression and Cell Apoptosis by Pretreatment With Captopril
Authors: Zagariya Alex , Bhat Rama , Navale Shan , Chari Gopal , Vidyasagar Dhormapuri 
Published: May 2006

OBJECTIVE. To study whether pretreatment of newborn lungs by captopril inhibits meconium-induced lung injury and inflammatory cytokine expression.
DESIGN. Four groups of 2-week-old rabbit pups were used for the study: group 1, saline instilled rabbits; group 2, captopril-pretreated rabbits; group 3, meconium-instilled rabbits; and group 4, captopril-pretreated and then meconium-instilled rabbits. Each group was studied at different time points: 0, 2, 4, 8, and 24 hours after instillation of meconium. Experiments were done at the University of Illinois and Michael Reese Hospital at Chicago. After treatment and instillation of meconium, the right lung was fixed with formalin, and 2-μm slices were obtained for immunohistochemistry. The left lung was used for obtaining of lung lavage and measurement of total proteins (for enzyme-linked immunosorbent assay) and mRNA (for reverse transcription-polymerase chain reaction) purification.
RESULTS. We found that meconium induces inflammatory cytokine expression and apoptotic lung cell death. In situ end labeling revealed a dramatic DNA fragmentation in the meconium group, which supports the presence of apoptosis. Using enzyme-linked immunosorbent assay, we demonstrated increase of interleukin 6 and interleukin 8 cytokines in meconium-instilled lungs, which were significantly decreased in captopril-pretreated lungs. Captopril pretreatment also decreased meconium-induced cell death and angiotensinogen expression. We believe this effect is explained by the ability of captopril to decrease processing of ANGEN to angiotensinogen (ANG) I and finally to ANG II. It suggests that captopril inhibits ANG II-induced lung cell apoptosis.
CONCLUSION. Our results demonstrate that captopril pretreatment significantly inhibits meconium-induced lung cell death, cytokine, and ANGEN expression in newborn lungs.
Predictors of Fatality in Postdiarrheal Hemolytic Uremic Syndrome
Authors: Oakes Robert S. , Siegler Richard L. , McReynolds Markham A. , Pysher Theodore , Pavia Andrew T. 
Published: May 2006

OBJECTIVES. Describe the cause of deaths among patients with postdiarrheal hemolytic uremic syndrome (HUS) and identify predictors of death at the time of hospital admission.METHODS. Case-control study of 17 deaths among patients with HUS identified from the Intermountain HUS Patient Registry (1970–2003) compared against all nonfatal cases.RESULTS. Of the 17 total deaths, 15 died during the acute phase of disease. Two died because treatment was withdrawn based on their preexisting conditions, and 1 died because of iatrogenic cardiac tamponade; they were excluded from analysis. Brain involvement was the most common cause of death (8 of 12); congestive heart failure, pulmonary hemorrhage, and hyperkalemia were infrequent causes. Presence of prodromal lethargy, oligoanuria, or seizures and white blood cell count (WBC) &gt;20 × 109/L or hematocrit &gt;23% on admission were predictive of death. In multivariate analysis, elevated WBC and elevated hematocrit were independent predictors. The combination of prodromal dehydration, oliguria, and lethargy and admission WBC values &gt;20 × 109/L and hematocrit &gt;23% appeared in 7 of the 12 acute-phase deaths.CONCLUSIONS. Diarrheal HUS patients presenting with oligoanuria, dehydration, WBC &gt;20 × 109/L, and hematocrit &gt;23% are at substantial risk for fatal hemolytic uremic syndrome. Such individuals should be referred to pediatric tertiary care centers.
Economic Analysis of Prevaccination Serotesting Compared With Presumptive Immunization for Polio, Diphtheria, and Tetanus in Internationally Adopted and Immigrant Infants
Authors: Cohen Adam L. , Veenstra David 
Published: May 2006

BACKGROUND. No consensus exists about whether to conduct prevaccination serotesting or to presumptively vaccinate internationally adopted and immigrant infants with inactivated polio (IPV) and diphtheria-tetanus-acellular pertussis (DTaP) immunizations.
OBJECTIVE. To study the clinical and economic outcomes from a societal perspective of prevaccination serotesting in a hypothetical 12-month-old internationally adopted or immigrant infant.
DESIGN AND METHODS. A decision analysis model was developed comparing presumptive vaccination with IPV versus serotesting for poliovirus type 1, 2, and 3 antibodies followed by vaccination in unprotected patients. A similar decision analysis model was developed comparing presumptive vaccination with DTaP versus serotesting for diphtheria and tetanus toxoid antibodies. The main outcome measures were cost per patient protected from polio, diphtheria, and tetanus.
RESULTS. Compared with presumptive immunization, prevaccination serotesting for polio increases the cost per patient from $57 to $62 and decreases the percentage of patients protected against polio from 95.3% to 94.0%. Serotesting for diphtheria and tetanus increases the cost per patient from $62 to $119 and increases the percentage of patients protected against both diphtheria and tetanus from 91.5% to 92.3%. Presumptive immunization with DTaP costs less and is more clinically effective than serotesting if &gt;80% of patients do not complete the full vaccine series or if antibody seroprevalence to both diphtheria and tetanus is &lt;51%.
CONCLUSIONS. Presumptive immunization for polio improves outcomes and saves costs compared with prevaccination serotesting in internationally adopted and immigrant infants. The results for DTaP are less definitive, although immunization is the preferred strategy in populations with poor vaccine compliance or low seroprevalence of antibodies to diphtheria and tetanus.
The Associations Among Childhood Headaches, Emotional and Behavioral Difficulties, and Health Care Use
Authors: Strine Tara W. , Okoro Catherine A. , McGuire Lisa C. , Balluz Lina S. 
Published: May 2006

BACKGROUND. Headaches are common among children and adolescents, particularly migraine and tension-type headaches. They contribute to missed school days, affect children's peer and family relationships, and significantly impact children's quality of life, often times into adulthood.
OBJECTIVES. This study, based on responses to the Strengths and Difficulties Questionnaire, was designed to examine difficulties and impairments related to emotions, concentration, behavior, and social functioning among children with frequent or severe headaches (FSH).
METHODS. We used a cross-sectional study of 9264 children aged 4–17 years from the 2003 National Health Interview Survey, an ongoing, computer-assisted personal interview survey of the noninstitutionalized US population.
RESULTS. Approximately 6.7% of children experienced FSH during the previous 12 months. Overall, children with FSH were 3.2 times more likely than children without FSH to have a high level of difficulties and 2.7 times more likely to have a high level of impairment, suggesting potential mental health issues. More specifically, analyses revealed that children with FSH were significantly more likely than those without FSH to exhibit high levels of emotional, conduct, inattention-hyperactivity, and peer problems and were significantly more likely than children without FSH to be upset or distressed by their difficulties and to have their difficulties interfere with home life, friendships, classroom learning, and leisure activities.
CONCLUSION. Because children with FSH experience notable pain, mental health issues, and functional limitations, integrated care using a biopsychosocial approach is warranted.