bluuebunny/crossref_metadata_2025 huggingface dataset:
Uncomplicated Metabolic Syndrome Is Associated with Prolonged Electrocardiographic QTc Interval and QTc Dispersion
Authors: Soydinc Serdar , Davutoglu Vedat , Akcay Murat
Published: October 2006

Aim: Metabolic syndrome is associated with increased risk of mortality and morbidity. The present study evaluates the repolarization abnormalities in patients with uncomplicated metabolic syndrome measuring corrected QT interval (QTc) and corrected QT dispersion (QTd) on electrocardiogram.

Methods: The study involved 83 subjects. A total of 50 individuals met criteria of metabolic syndrome (Group A: 11 men, 39 women, mean body mass index (BMI) 36.7 kg/m2, mean waist circumference 117.3 cm). And 33 participants were healthy normal volunteers (Group B: 9 men, 24 women, mean BMI 21.3 kg/m2, mean waist circumference 76.2 cm). The two groups were matched for age and sex. Metabolic syndrome was diagnosed according to the Adult Treatment Panel III criteria. The QTc intervals and QTd were measured.

Results: Patients with uncomplicated metabolic syndrome had significantly higher values of QTc‐min, QTc‐max, and QTd than control group (P < 0.001).

Conclusion: Patients with uncomplicated metabolic syndrome have a greater dispersion of ventricular repolarization time and increased QTc‐min and QTc‐max.
An efficacy and safety analysis of a chlorhexidine chewing gum in young orthodontic patients
Authors: Cosyn Jan , Verelst Kathleen
Published: October 2006

Aim: The objective of the present study was to investigate the impact of a chlorhexidine (CHX) chewing gum in teenage orthodontic patients on plaque levels, gingival bleeding tendency and tooth staining.

Materials and Methods: A randomized‐controlled, double‐blind, parallel study was conducted on 31 teenagers in fixed orthodontic therapy. Subjects of the CHX gum group were asked to continue their oral hygiene procedures in conjunction with chewing two pieces of a 5 mg CHX‐containing chewing gum for 10 min. twice a day for 3 months. Subjects of the placebo gum group received the same instructions; however, using a CHX‐free chewing gum. Plaque levels, gingival bleeding on probing and tooth staining were monitored at baseline and subsequently after 1–3 months.

Results: Plaque levels significantly decreased from baseline at lingual/palatal sites in the placebo gum group. In the CHX gum group, a similar, yet non‐significant trend was observed. At buccal sites, plaque levels remained unaffected in both groups. Gingival bleeding tendency significantly decreased in both groups, predominantly at lingual/palatal sites. There were no significant between‐group differences in any of the efficacy parameters at any time point. However, the increase in staining was nearly five times higher in the CHX gum group.

Conclusions: There seems to be no indication for a CHX chewing gum in teenage orthodontic patients when used as an adjunct to normal oral hygiene practices.
The Antecedents and Consequences of Adolescents’ Relationships With Stepfathers and Nonresident Fathers
Authors: King Valarie
Published: October 2006

Using data from a sample of 1,149 adolescents in the National Longitudinal Study of Adolescent Health who have both a resident stepfather and a nonresident biological father, this study examines the prevalence, antecedents, and consequences of adolescents’ closeness to their stepfathers and nonresident fathers. Findings demonstrate that adolescents vary greatly in their likelihood of having close relationships with one or both of their fathers, but when they do so, they appear to benefit. Close relationships with both stepfathers and nonresident fathers are associated with better adolescent outcomes, with ties to stepfathers being somewhat more influential than ties to nonresident fathers.
Norms of Filial Responsibility for Aging Parents Across Time and Generations
Authors: Gans Daphna , Silverstein Merril
Published: October 2006

This investigation examined the normative expectation that adult children should be responsible for the care of their aging parents, and how this norm changes over the adult life span, across several decades of historical time, in relation to generational position in families, and between successive generations. Analyses were performed using 4 waves of data from the University of Southern California (USC) Longitudinal Study of Generations between 1985 and 2000. A multilevel latent growth model was estimated using 4,527 observations from 1,627 individuals nested within 333 families. Results revealed that filial norms weakened after midlife, in response to parental death, and over historical time, yet strengthened in later‐born generations. Findings are discussed in terms of the malleability of filial responsibility over the life course.
Gender Differences in Adult Sibling Relations in Two‐Child Families
Authors: Spitze Glenna , Trent Katherine
Published: October 2006

We examine affective closeness, contact, and helping among adult siblings using data for over 1,500 respondents in 2‐child families from the National Survey of Families and Households. Using this subsample allows us to investigate differences by gender of respondent and of individual siblings using a nationally representative sample. We find that siblings are central to the lives of adults; most sibling relationships involve frequent contact and positive feelings. Sister pairs phone and exchange advice more often than do other sibling pairs. Women are more likely than men to report feeling close to or getting along with their sibling. We find no consistent differences in visiting. Giving and receiving help appear to reflect gendered forms of intimacy and of household labor.
Shared Beliefs and the Union Stability of Married and Cohabiting Couples
Authors: Hohmann‐Marriott Bryndl E.
Published: October 2006

Cohabiting couples and couples who cohabit prior to marriage have less stable relationships than married couples who did not cohabit, and these differences in stability may be linked to different processes within the relationships. This research examines the similarity of partners’ beliefs about the division of household labor using the National Survey of Families and Households (N = 1,039), finding that couples who do not share beliefs about the division of household labor are more likely to end their union. Cohabiting couples have a particularly high likelihood of ending the union when the two partners hold widely divergent views about whether housework should be shared, suggesting that cohabiting and married couples may have different responses to dissimilarity between the partners.
Cross‐Cultural Consistency of the Demand/Withdraw Interaction Pattern in Couples
Authors: Christensen Andrew , Eldridge Kathleen , Catta‐Preta Adriana Bokel , Lim Veronica R. , Santagata Rossella
Published: October 2006

In order to examine the cross‐cultural consistency of several patterns of couple communication, 363 participants from four different countries (Brazil, Italy, Taiwan, and the United States) completed self‐report measures about communication and satisfaction in their romantic relationships. Across countries, constructive communication was positively associated with relationship satisfaction, whereas demand/withdraw communication was negatively associated with relationship satisfaction. Woman demand/man withdraw communication was significantly more likely than man demand/woman withdraw communication. Also, some evidence suggested women wanted greater closeness versus independence in their relationships than did men. Differences between partners in desire for closeness versus independence were associated with greater demand/withdraw communication. The possible bases for the demand/withdraw pattern of communication and its gender linkage are discussed.
Childlessness Among Older Women in the United States: Trends and Profiles
Authors: Abma Joyce C. , Martinez Gladys M.
Published: October 2006

In the last 2 decades, the United States has seen an increase in childlessness and first births at older ages. Using the National Survey of Family Growth, we focus on women aged 35 – 44 who are voluntarily childless (expect no children and are fecund or contraceptively sterile). We compare these women to those who are involuntarily childless (fecundity impaired) and to those who are temporarily childless (expect children). Voluntary childlessness grew from 1982 (5%) to 1988 (8%), was stable up to 1995 (9%), and fell slightly in 2002 (7%). Voluntarily childless women have the highest income, prior work experience, and lowest religiosity compared to other women. This has been true since 1982, the earliest time point examined.
Gender, Sibship Structure, and Educational Inequality in Taiwan: Son Preference Revisited
Authors: Yu Wei‐hsin , Su Kuo‐hsien
Published: October 2006

This study examines how sibship characteristics affect educational attainment in Taiwan. Using a multilevel analysis of a sibling sample of 12,715 observations from 3,001 families drawn from a national survey, we investigate the effects of family size, sibship density, birth‐order rank, and sibship gender composition. The results support the argument that the effect of son preference on intrafamily educational inequality is conditional on family resources. We also find, however, that male firstborns, who are the ultimate inheritors of paternal authority in Chinese families, have additional leverage in the sibling competition for family resources. The privilege for firstborns does not extend to daughters. Therefore, we argue that culturally defined norms regarding seniority and gender help shape intrafamily resource allocation in Chinese society.
Saccharomyces cerevisiaeα1,6‐mannosyltransferase has a catalytic potential to transfer a second mannose molecule
Authors: Kitajima Toshihiko , Chiba Yasunori , Jigami Yoshifumi
Published: October 2006

In yeast, the N‐linked oligosaccharide modification in the Golgi apparatus is initiated by α1,6‐mannosyltransferase (encoded by the OCH1 gene) with the addition of mannose to the Man8GlcNAc2 or Man9GlcNAc2 endoplasmic reticulum intermediates. In order to characterize its enzymatic properties, the soluble form of the recombinant Och1p was expressed in the methylotrophic yeast Pichia pastoris as a secreted protein, after truncation of its transmembrane region and fusion with myc and histidine tags at the C‐terminus, and purified using a metal chelating column. The enzymatic reaction was performed using various kinds of pyridylaminated (PA) sugar chains as acceptor, and the products were separated by high performance liquid chromatography. The recombinant Och1p efficiently transferred a mannose to Man8GlcNAc2‐PA and Man9GlcNAc2‐PA acceptors, while Man5GlcNAc2‐PA, which completely lacks α1,2‐linked mannose residues, was not used as an acceptor. At high enzyme concentrations, a novel product was detected by HPLC. Analysis of the product revealed that a second mannose was attached at the 6‐O‐position of α1,3‐linked mannose branching from the α1,6‐linked mannose that is attached to β1,4‐linked mannose of Man10GlcNAc2‐PA produced by the original activity of Och1p. Our results indicate that Och1p has the potential to transfer two mannoses from GDP‐mannose, and strictly recognizes the overall structure of high mannose type oligosaccharide.
Increased Susceptibility to Phenytoin Teratogenicity: Excessive Generation of Reactive Oxygen Species or Impaired Antioxidant Defense?
Authors: Azarbayjani Faranak , Borg L. A. Håkan , Danielsson Bengt R.
Published: October 2006

Abstract: Phenytoin is a human and animal teratogen. Accumulating evidence suggests that the teratogenicity is associated with a potential of phenytoin to cause embryonic cardiac arrhythmia and resultant generation of toxic reactive oxygen species via hypoxia‐reoxygenation mechanisms. The A/J mouse is more susceptible to phenytoin teratogenicity than other mouse strains. The aim of this study was to investigate whether A/J mice have other antioxidant enzyme activities than C57BL/6J and CD‐1 mice. Also, strain differences in phenytoin effects on embryonic heart rate and rhythm were determined. Another objective was to determine whether a spin trapping agent with capacity to capture reactive oxygen species alter the developmental toxicity of phenytoin. Treatment with this agent resulted in a marked decrease in phenytoin teratogenicity, which supports the idea that reactive oxygen species are important mediators for the teratogenic action of phenytoin. The A/J mice embryos were most susceptible to the adverse cardiac effects of phenytoin and had the highest activity of superoxide dismutase and glutathione peroxidase, while the activity of catalase was the same in embryos of the three different strains. The high activities of antioxidant enzymes in the A/J stain indicate that the sensitivity to develop malformations is caused by excessive arrhythmia‐related generation of reactive oxygen species rather than impaired antioxidant defense.
The Established and Emerging Uses of Aspirin
Authors: Morgan Gareth
Published: October 2006

Abstract: In this paper, summary narratives on the established and emerging uses of aspirin are presented. On the former, aspirin is used to treat conditions such as headache and also reduce the risks associated with cardiovascular disease and also with pre‐eclampsia. On the latter, aspirin might be taken more widely by individuals over 50 years, used as a dietary supplement to possibly reduce cancer risk and used post‐transplant to improve organ survival. Aspirin will continue to be an important therapeutic agent and to generate considerable interest among the research community for the foreseeable future.
Protection of Azidothymidine‐Induced Cardiopathology in Mice by Mildronate, a Mitochondria‐Targeted Drug
Authors: Klusa Vija , Pupure Jolanta , Isajevs Sergejs , Rumaks Juris , Gordjushina Valentina , Kratovska Aina , Taivans Immanuels , Svirskis Simons , Viksna Ludmila , Kalvinsh Ivars
Published: October 2006

Abstract:Azidothymidine, a nucleoside‐analogue reverse transcriptase inhibitor (NRTI), is a commonly used antiretroviral drug in AIDS treatment, however its use is limited by severe toxic side effects due to its influence on mitochondria that result in myopathy, particularly affecting the cardiac muscle. We suggest that effective protection of azidothymidine‐induced cardiopathology can be expected from drugs that are capable of targeting mitochondria. Therefore the present study in mice was carried out with mildronate, a cardioprotective drug of the aza‐butyrobetaine class, which previously has been shown to act as a highly potent protector of mitochondrial processes. In our study, saline (control), azidothymidine (50 mg/kg), mildronate (50, 100 and 200 mg/kg), and azidothymidine + mildronate (at the doses mentioned) were injected intraperitoneally daily in separate groups of mice for two weeks. At the termination of the experiment, mice were sacrificed, the hearts were removed and cardiac tissue was examined morphologically and immunohistochemically. It was found that azidothymidine, compared to control and mildronate groups, induced major morphologic changes in cardiac tissue, which were manifestated as degeneration and inflammation. These changes were prevented when mildronate was co‐administered with azidothymidine. Mildronate also reduced the azidothymidine‐induced expression of nuclear factor κBp65 (NF‐κBp65). The obtained data demonstrate a high ability of mildronate of preventing azidothymidine‐induced cardiopathologic changes, and suggest mildronate's indirect action on azidothymidine‐caused oxidative stress reactions leading to mitochondrial dysfunction. This offers a rational combination of mildronate with azidothymidine or other anti‐HIV drugs for beneficial application in AIDS therapy.
The Prevalence of Sexual Dysfunction and Potential Risk Factors That May Impair Sexual Function in Malaysian Women
Authors: Sidi Hatta , Puteh Sharifah Ezat Wan , Abdullah Norni , Midin Marhani
Published: October 2006

Introduction

Female sexual dysfunction (FSD) is a prevalent sexual health problem that does not spare the women in Malaysia, a nation with a conservative multiethnic society.

Aim

To investigate the prevalence of FSD and the potential risk factors that may impair sexual function among women at a primary care setting in Malaysia.

Main Outcome Measure

The prevalence, the risk factors, and the main predictors for FSD were measured among these women.

Methods

A validated Malay version of the Female Sexual Function Index was used to assess FSD. A total of 230 married women aged 18–70 years participated in this study. The sociodemographic and marital profiles of women who had FSD and those who did not were compared; the risk factors for FSD were determined.

Results

The majority of the respondents were younger than 50 years old, predominantly Malays, and had a higher academic achievement. The prevalence of FSD in the primary care population was 29.6%. The prevalence of women with lack of orgasms, low sexual arousal, lack of lubrication, sexual dissatisfaction, and sexual pain were 59.1%, 60.9%, 50.4%, 52.2%, and 67.8%, respectively.

Conclusion

The risk factors for FSD are older age, Malays, married longer (more than 14 years), having less sexual intercourse (less than 1–2 times a week), having more children, married to an older husband (aged >42 years), and having a higher academic status. Lack of lubrication is found to be the main predictor for FSD in this study. Is lack of lubrication a cause or a complication of FSD? Prospective research is needed in the near future.
Galaxy clusters at 0.6 < z < 1.4 in the UKIDSS Ultra Deep Survey Early Data Release
Authors: Van Breukelen C. , Clewley L. , Bonfield D. G. , Rawlings S. , Jarvis M. J. , Barr J. M. , Foucaud S. , Almaini O. , Cirasuolo M. , Dalton G. , Dunlop J. S. , Edge A. C. , Hirst P. , McLure R. J. , Page M. J. , Sekiguchi K. , Simpson C. , Smail I. , Watson M. G.
Published: October 2006

We present the first cluster catalogue extracted from the UKIRT Infrared Deep Sky Survey (UKIDSS) Early Data Release. The catalogue is created using UKIDSS Ultra Deep Survey infrared J and K data combined with 3.6- and 4.5-μm Spitzer bands and optical BVRi′z′ imaging from the Subaru Telescope over 0.5 deg2 in the Subaru XMM–Newton Deep Field. We have created a new cluster detection algorithm, based on the friends-of-friends and Voronoi tessellation methods, which utilizes probability distribution functions derived from a photometric redshift analysis. We employ mock catalogues to understand the selection effects and contamination associated with the algorithm. The cluster catalogue contains 13 clusters at redshifts 0.61 ≤z≤ 1.39 with luminosities 10 L*≲Ltot≲ 50 L*, corresponding to masses 5 × 1013≲Mcluster≲ 3 × 1014 M⊙ for (M/M⊙)/(L/L⊙) = 75 h. The measured sky surface density of ∼10 clusters deg−2 for high-redshift (z= 0.5–1.5), massive (> 1014 M⊙) clusters is precisely in line with theoretical predictions presented by Kneissl et al.
Supply Base Reduction: An Empirical Study of Critical Success Factors
Authors: Ogden Jeffrey A.
Published: October 2006

One important factor in the design of an organization's supply chain is the number of suppliers used for a given product or service. Supply base reduction is one option useful in managing the supply base. The current paper reports the results of case studies in 10 organizations that recently implemented supply base reduction activities. Specifically, the paper identifies the key success factors in supply base reduction efforts and prescribes processes to capture the benefits of supply base reduction.
Evaluation of the Antibacterial Spectrum of Drosocin Analogues
Authors: Bikker Floris J. , Kaman‐van Zanten Wendy E. , De Vries‐van de Ruit Anne‐Marij B. C. , Voskamp‐Visser Ingrid , Van Hooft Peter A. V. , Mars‐Groenendijk Roos H. , De Visser Peter C. , Noort Daan
Published: October 2006

Drosocin is a 19‐mer, cationic antimicrobial peptide from Drosophila melanogaster. The aim of the study was to examine the antibacterial spectrum of unglycosylated drosocin analogues. Furthermore, the amino acid sequence of DnaK, drosocin's intracellular target, from susceptible species was aligned and studied for sequence homology. From this a panel of 31 bacterial strains, including Salmonella strains with truncated lipopolysaccharide structures, was tested for susceptibility towards three drosocin analogues. Available bacterial DnaK amino acid sequences were retrieved from the ExPASy proteomics server of the Swiss Institute of Bioinformatics studied for sequence homology. Seventeen of the 31 strains tested were susceptible for the drosocin analogues. Minimal inhibitory concentration values against mainly Gram‐negative bacteria ranged from 3.1 to 100 μm. With the exception of Micrococcus luteus and Xanthomonas campestris all drosocin analogue‐susceptible strains were Enterobacteriaceae showing a high DnaK amino acid sequence homology.
Emerging Respiratory Viruses: Challenges and Vaccine Strategies
Authors: Gillim-Ross Laura , Subbarao Kanta
Published: October 2006

The current threat of avian influenza to the human population, the potential for the reemergence of severe acute respiratory syndrome (SARS)-associated coronavirus, and the identification of multiple novel respiratory viruses underline the necessity for the development of therapeutic and preventive strategies to combat viral infection. Vaccine development is a key component in the prevention of widespread viral infection and in the reduction of morbidity and mortality associated with many viral infections. In this review we describe the different approaches currently being evaluated in the development of vaccines against SARS-associated coronavirus and avian influenza viruses and also highlight the many obstacles encountered in the development of these vaccines. Lessons learned from current vaccine studies, coupled with our increasing knowledge of the host and viral factors involved in viral pathogenesis, will help to increase the speed with which efficacious vaccines targeting newly emerging viral pathogens can be developed.
Helicobacter pyloriPersistence: an Overview of Interactions betweenH. pyloriand Host Immune Defenses
Authors: Algood Holly M. Scott , Cover Timothy L.
Published: October 2006

Helicobacter pyloriis a gram-negative bacterium that persistently colonizes more than half of the global human population. In order to successfully colonize the human stomach,H. pylorimust initially overcome multiple innate host defenses. Remarkably,H. pylorican persistently colonize the stomach for decades or an entire lifetime despite development of an acquired immune response. This review focuses on the immune response toH. pyloriand the mechanisms by whichH. pyloriresists immune clearance. Three main sections of the review are devoted to (i) analysis of the immune response toH. pyloriin humans, (ii) analysis of interactions ofH. pyloriwith host immune defenses in animal models, and (iii) interactions ofH. pyloriwith immune cells in vitro. The topics addressed in this review are important for understanding howH. pyloriresists immune clearance and also are relevant for understanding the pathogenesis of diseases caused byH. pylori(peptic ulcer disease, gastric adenocarcinoma, and gastric lymphoma).
Ventilator-Associated Pneumonia: Diagnosis, Treatment, and Prevention
Authors: Koenig Steven M. , Truwit Jonathon D.
Published: October 2006

While critically ill patients experience a life-threatening illness, they commonly contract ventilator-associated pneumonia. This nosocomial infection increases morbidity and likely mortality as well as the cost of health care. This article reviews the literature with regard to diagnosis, treatment, and prevention. It provides conclusions that can be implemented in practice as well as an algorithm for the bedside clinician and also focuses on the controversies with regard to diagnostic tools and approaches, treatment plans, and prevention strategies.
Human Pharmacogenomic Variations and Their Implications for Antifungal Efficacy
Authors: Meletiadis Joseph , Chanock Stephen , Walsh Thomas J.
Published: October 2006

Pharmacogenomics is defined as the study of the impacts of heritable traits on pharmacology and toxicology. Candidate genes with potential pharmacogenomic importance include drug transporters involved in absorption and excretion, phase I enzymes (e.g., cytochrome P450-dependent mixed-function oxidases) and phase II enzymes (e.g., glucuronosyltransferases) contributing to metabolism, and those molecules (e.g., albumin, A1-acid glycoprotein, and lipoproteins) involved in the distribution of antifungal compounds. By using the tools of population genetics to define interindividual differences in drug absorption, distribution, metabolism, and excretion, pharmacogenomic models for genetic variations in antifungal pharmacokinetics can be derived. Pharmacogenomic factors may become especially important in the treatment of immunocompromised patients or those with persistent or refractory mycoses that cannot be explained by elevated MICs and where rational dosage optimization of the antifungal agent may be particularly critical. Pharmacogenomics has the potential to shift the paradigm of therapy and to improve the selection of antifungal compounds and adjustment of dosage based upon individual variations in drug absorption, metabolism, and excretion.
GAUGE THEORY ON A FOUR-DIMENSIONAL QUANTUM SPACE
Authors: EL BAZ M.
Published: October 2006

In this paper, a generalization and extension of some recent results is proposed. Namely, a four-dimensional quantum space is constructed and a differential calculus, obeying the usual criteria of covariance, is built upon this space. These results are then used to construct a gauge theory on this four-dimensional quantum space.
BOULWARE STATE IN EXACTLY SOLVABLE MODELS OF 2D DILATON GRAVITY
Authors: ZASLAVSKII O. B.
Published: October 2006

We discuss self-consistent geometries and behavior of dilaton in exactly solvable models of 2D dilaton gravity, with quantum fields in the Boulware state. If the coupling H(ϕ) between curvature and dilaton ϕ is non-monotonic, back-reaction can remove the classical singularity. As a result, an everywhere regular star-like configuration may appear, in which case the Boulware state, contrary to expectations, smooths out the system. For monotonic H(ϕ), exact solutions confirm the features found before with the help of numerical methods: the appearance of the bouncing point and the presence of isotropic singularity at the classically forbidden branch of the dilaton.
FOURTH-ORDER GRAVITY AND EXPERIMENTAL CONSTRAINTS ON EDDINGTON PARAMETERS
Authors: CAPOZZIELLO S. , STABILE A. , TROISI A.
Published: October 2006

PPN-limit of alternative theories of gravity represents a still controversial matter of debate and no definitive answer has been provided, up to now, about this issue. By using the definition of the PPN-parameters γ and β in terms of f(R) theories of gravity, we show that a family of third-order polynomial theories, in the Ricci scalar R, turns out to be compatible with the PPN-limit and the deviation from General Relativity, theoretically predicted, can agree with experimental data.
THE FLUX OF NONCOMMUTATIVE U(1) INSTANTON THROUGH THE FUZZY SPHERES
Authors: HENNI A. A. , LAGRAA M.
Published: October 2006

From the ADHM construction on noncommutative [Formula: see text] vector space, we investigate different U(1) instanton solutions tied by partial isometry transformations. We recast these solutions under a form of vector fields in noncommutative [Formula: see text] vector space which makes possible the calculus of their fluxes through fuzzy spheres. For this end, we establish the noncommutative analog of Gauss theorem from which we show that the flux of the U(1) instantons through fuzzy spheres does not depend on the radius of these spheres and it is invariant under partial isometry transformations.
THE SOLUTIONS OF THE DYSON–SCHWINGER EQUATION FOR QUARK PROPAGATOR IN THE CASE OF NONZERO CURRENT QUARK MASS
Authors: ZONG HONG-SHI , FENG HONG-TAO , HOU FENG-YAO , SUN WEI-MIN
Published: October 2006

In the framework of rainbow approximation of the Dyson–Schwinger equation approach, it is shown that there exist two qualitatively distinct solutions of the Dyson–Schwinger equation for the quark propagator in the case of nonzero current quark mass. One solution corresponds to the "Nambu–Goldstone" phase and the other one corresponds to the "Wigner" phase in the chiral limit.
FORCES IN KERR SPACE–TIMES WITH A REPULSIVE COSMOLOGICAL CONSTANT
Authors: KOVÁŘ JIŘÍ , STUCHLÍK ZDENĚK
Published: October 2006

Forces defined in the framework of optical reference geometry are introduced in the case of stationary and axially symmetric Kerr black hole and naked-singularity space–times with a repulsive cosmological constant. Properties of the forces acting on test particles moving along circular orbits in the equatorial plane are discussed, whereas it is shown where the gravitational force vanishes and changes its orientation and where the centrifugal force vanishes and changes its orientation independently of the velocity of test particles related to the optical geometry; the Coriolis force does not vanish for the velocity being nonzero. The space–times are classified according to the number of circular orbits where the gravitational and centrifugal forces vanish.
REALITY CONDITION FOR DARBOUX TRANSFORMATIONS OF TIME-DEPENDENT SCHRÖDINGER EQUATIONS WITH EFFECTIVE MASS
Authors: SCHULZE-HALBERG AXEL
Published: October 2006

We set up a reality condition for Darboux transformations of time-dependent Schrödinger equations (TDSE) with position-dependent (effective) mass. The reality condition guarantees the potential in the transformed TDSE to be real-valued and hence physical. This paper is a sequel of our former one.36
N = 2 SUPERSYMMETRIC YANG–MILLS AND THE QUANTUM HALL EFFECT
Authors: DOLAN BRIAN P.
Published: October 2006

It is argued that there are strong similarities between the infrared physics of N = 2 supersymmetric Yang–Mills and that of the quantum Hall effect, both systems exhibit a hierarchy of vacua with a subgroup of the modular group mapping between them. The coupling flow for pure SU(2) N = 2 supersymmetric Yang–Mills in four dimensions is reexamined and an earlier suggestion in the literature, that was singular at strong coupling, is modified to a form that is well behaved at both weak and strong coupling and describes the crossover in an analytic fashion. Similarities between the phase diagram and the flow of SUSY Yang–Mills and that of the quantum Hall effect are then described, with the Hall conductivity in the latter playing the role of the θ-parameter in the former. Hall plateaux, with odd denominator filling fractions, are analogous to fixed points at strong coupling in N = 2 SUSY Yang–Mills, where the massless degrees of freedom carry an odd monopole charge.
Dimerization of CXCR4 in living malignant cells: control of cell migration by a synthetic peptide that reduces homologous CXCR4 interactions
Authors: Wang Jinhai , He Liusheng , Combs Christian A. , Roderiquez Gregory , Norcross Michael A.
Published: October 2006

Chemokine receptor CXCR4 (CD184) may play a role in cancer metastasis and is known to form homodimers. However, it is not clear how transmembrane regions (TM) of CXCR4 and receptor homotypic interactions affect the function of CXCR4 in living cells. Using confocal microscopy and flow cytometric analysis, we showed that high levels of CXCR4 are present in the cytoplasm, accompanied by lower expression on the cell surface in CXCR4 transfectants, tumor cells, and normal peripheral blood lymphocytes. CXCR4 homodimers were detected in tumor cells, both on the cell surface membrane and in the cytoplasm using fluorescence resonance energy transfer and photobleaching fluorescence resonance energy transfer to measure energy transfer between CXCR4-CFP and CXCR4-YFP constructs. Disruption of lipid rafts by depletion of cholesterol with methyl-β-cyclodextrin reduced the interaction between CXCR4 molecules and inhibited malignant cell migration to CXCL12/SDF-1α. A synthetic peptide of TM4 of CXCR4 reduced energy transfer between molecules of CXCR4, inhibited CXCL12-induced actin polymerization, and blocked chemotaxis of malignant cells. TM4 also inhibited migration of normal monocytes toward CXCL12. Reduction of CXCR4 energy transfer by the TM4 peptide and methyl-β-cyclodextrin indicates that interactions between CXCR4s may play important roles in cell migration and suggests that cell surface and intracellular receptor dimers are appropriate targets for control of tumor cell spread. Targeting chemokine receptor oligomerization and signal transduction for the treatment of cancer, HIV-1 infections, and other CXCR4 mediated inflammatory conditions warrants further investigation. [Mol Cancer Ther 2006;5(10):2474–83]
The mechanism of methylselenocysteine and docetaxel synergistic activity in prostate cancer cells
Authors: Azrak Rami G. , Frank Cheryl L. , Ling Xiang , Slocum Harry K. , Li Fengzhi , Foster Barbara A. , Rustum Youcef M.
Published: October 2006

The study was designed to evaluate the combination treatment of methylselenocysteine (MSeC) and docetaxel and to delineate the underlying mechanism associated with observed in vitro synergy between MSeC and docetaxel in prostate cancer cells. Cells were treated with different concentrations and schedules (concurrent or sequential) of MSeC and docetaxel alone or in combination. Cell growth/death was assessed with sulforhodamine B assay, trypan blue assay, and time-lapse video. Loewe synergism/antagonism model was used to determine whether the combination effect was additive, synergistic, or antagonistic. Apoptosis and caspase-3 activity were evaluated with cell death ELISA assay and caspase activity assay, respectively. Synergy between MSeC and docetaxel was further assessed in the presence and absence of z-VAD-fmk, a pan-caspase inhibitor. Effect of MSeC and docetaxel alone or in combination on the cellular expression of the antiapoptotic protein survivin was measured with Western blot analyses. Pretreatment with MSeC was crucial to enhance docetaxel antitumor activity. The enhanced antitumor activity of the sequential combination treatment of MSeC and docetaxel (MSeC/docetaxel) was highly synergistic. Apoptosis increased after MSeC/docetaxel, compared with each drug alone or concurrent treatment. Pretreatment with z-VAD-fmk converted the synergy into antagonism, suggesting that the synergy is caspase-dependent apoptosis. The survivin level was down-regulated following MSeC/docetaxel treatment when compared with each drug alone. In conclusion, pretreatment with MSeC was essential to markedly sensitize cells to docetaxel. The synergy between MSeC and docetaxel in C2G prostate cancer cells is associated with increased level of caspase-dependent apoptosis and decreased level of survivin. [Mol Cancer Ther 2006;5(10):2540–8]
The antitumor effects of sunitinib (formerly SU11248) against a variety of human hematologic malignancies: enhancement of growth inhibition via inhibition of mammalian target of rapamycin signaling
Authors: Ikezoe Takayuki , Nishioka Chie , Tasaka Taizo , Yang Yang , Komatsu Naoki , Togitani Kazuto , Koeffler H. Phillip , Taguchi Hirokuni
Published: October 2006

We studied antitumor effects of receptor tyrosine kinase inhibitor sunitinib (formerly SU11248) against a variety of hematologic malignancies including the following leukemias: eosinophilic (EOL-1), acute myeloid (THP-1, U937, Kasumi-1), biphenotypic (MV4-11), acute lymphoblastic (NALL-1, Jurkat, BALL-2, PALL-1, PALL-2), blast crisis of chronic myeloid (KU812, Kcl-22, K562), and adult T-cell (MT-1, MT-2, MT-4), as well as non-Hodgkin's lymphoma (KS-1, Dauji, Akata) and multiple myeloma (U266). Thymidine uptake studies showed that sunitinib was active against EOL-1, MV4-11, and Kasumi-1 cells, which possessed activating mutations of the PDGFRα, FLT-3, and c-KIT genes, respectively, with IC50s of <30 nmol/L. In addition, sunitinib inhibited the proliferation of freshly isolated leukemia cells from patients possessing mutations in FLT3 gene. Annexin V staining showed that sunitinib induced apoptosis of these cells. Sunitinib inhibited phosphorylation of FLT3 and PDGFRα in conjunction with blockade of mammalian target of rapamycin signaling in MV4-11 and EOL-1 cells, respectively. Interestingly, rapamycin analogue RAD001 enhanced the ability of sunitinib to inhibit the proliferation of leukemia cells and down-regulate levels of mammalian target of rapamycin effectors p70 S6 kinase and eukaryotic initiation factor 4E–binding protein 1 in these cells. Taken together, sunitinib may be useful for treatment of individuals with leukemias possessing activation mutation of tyrosine kinase, and the combination of sunitinib and RAD001 represents a promising novel treatment strategy. [Mol Cancer Ther 2006;5(10):2522–30]
Synthesis and biological analysis of new curcumin analogues bearing an enhanced potential for the medicinal treatment of cancer
Authors: Ohori Hisatsugu , Yamakoshi Hiroyuki , Tomizawa Masaki , Shibuya Masatoshi , Kakudo Yuichi , Takahashi Atsuko , Takahashi Shin , Kato Satoshi , Suzuki Takao , Ishioka Chikashi , Iwabuchi Yoshiharu , Shibata Hiroyuki
Published: October 2006

Curcumin (diferuloylmethane) is a dietary phytochemical with low toxicity that exhibits growth-suppressive activity against a variety of cancer cells and possesses certain chemopreventive properties. Curcumin has already been the subject of several clinical trials for use as a treatment in human cancers. Synthetic chemical modifications of curcumin have been studied intensively in an attempt to find a molecule with similar but enhanced properties of curcumin. In this study, a series of novel curcumin analogues were synthesized and screened for anticancer activity. New analogues that exhibit growth-suppressive activity 30 times that of curcumin and other commonly used anticancer drugs were identified. Structurally, the new analogues are symmetrical 1,5-diarylpentadienone whose aromatic rings possess an alkoxy substitution at each of the positions 3 and 5. Analysis of the effects of the analogues on the expression of cancer-related genes usually affected by curcumin indicated that some induced the down-regulation of β-catenin, Ki-ras, cyclin D1, c-Myc, and ErbB-2 at as low as one eighth the concentration at which curcumin normally has an effect. The analogues, however, exhibited neither harmful nor growth-suppressive effects on normal hepatocytes where oncogene products are not activated. They also exhibited no toxicities in vivo that they may provide effective alternative therapies for the prevention and treatment of some human cancers. [Mol Cancer Ther 2006;5(10):2563–71]
Reverse phase protein array: validation of a novel proteomic technology and utility for analysis of primary leukemia specimens and hematopoietic stem cells
Authors: Tibes Raoul , Qiu YiHua , Lu Yiling , Hennessy Bryan , Andreeff Michael , Mills Gordon B. , Kornblau Steven M.
Published: October 2006

Proteomics has the potential to provide answers in cancer pathogenesis and to direct targeted therapy through the comprehensive analysis of protein expression levels and activation status. The realization of this potential requires the development of new, rapid, high-throughput technologies for performing protein arrays on patient samples, as well as novel analytic techniques to interpret them. Herein, we describe the validation and robustness of using reverse phase protein arrays (RPPA) for the analysis of primary acute myelogenous leukemia samples as well as leukemic and normal stem cells. In this report, we show that array printing, detection, amplification, and staining precision are very high, reproducible, and that they correlate with traditional Western blotting. Using replicates of the same sample on the same and/or separate arrays, or using separate protein samples prepared from the same starting sample, the intra- and interarray reproducibility was extremely high. No statistically significant difference in protein signal intensities could be detected within the array setups. The activation status (phosphorylation) was maintained in experiments testing delayed processing and preparation from multiple freeze-thawed samples. Differences in protein expression could reliably be detected in as few as three cell protein equivalents. RPPA prepared from rare populations of normal and leukemic stem cells were successfully done and showed differences from bulk populations of cells. Examples show how RPPAs are ideally suited for the large-scale analysis of target identification, validation, and drug discovery. In summary, RPPA is a highly reliable, reproducible, high-throughput system that allows for the rapid large-scale proteomic analysis of protein expression and phosphorylation state in primary acute myelogenous leukemia cells, cell lines, and in human stem cells. [Mol Cancer Ther 2006;5(10):2512–21]
Tumor models for efficacy determination
Authors: Teicher Beverly A.
Published: October 2006

The first in vivo tumor models were developed in the mid-1960s. These models were mouse leukemia models grown as ascites. The growth pattern was like that of bacteria in vivo and therefore it was possible to apply similar mathematics of growth and response to these tumors as had been worked out for bacteria. Since the development of the murine leukemia models, investigators have devoted a large effort to modeling solid tumors in mice. There are now a variety of models including syngeneic mouse tumors and human tumor xenografts grown as s.c. nodules, syngeneic mouse tumors and human tumor xenografts grown in orthotopic sites, models of disseminated disease, “labeled” tumor models that can be visualized using varied technologies, and transgenic tumor models. Each of these types of models has advantages and disadvantages to the “drug hunter” searching for improved treatments. [Mol Cancer Ther 2006;5(10):2435–43]
(Mixed) Perceptions of Tribal Nations’ Status
Authors: Steinman Erich
Published: October 2006

This article examines the multiple and contradictory ways that tribes, as anomalies within American governance, have been conceptualized within popular opinion and federal Indian policy. It is the inconsistent treatment tribes have received, based on these differing conceptions, that makes Indian gaming so confusing and conflictual. Tribal gaming is conducted based on rights derived from an understanding of tribes as sovereign nations represented by governments. This status and the rights associated with it appear to conflict with perceptions and treatment of tribes as wards, minorities, rights holders, and corporations. Absent unlikely action by Congress to establish greater coherency across Indian policies, widespread variation, uncertainty, and conflict will continue to characterize tribal gaming. However, an understanding of tribes as sovereign governments is slowly being institutionalized within American governance and may shift the terms through which tribal gaming is publicly discussed.
True Lies
Authors: Andrade Ronald
Published: October 2006

This essay discusses the many stereotypical, and all too often hypocritical, views held by non-Indians concerning Indian gaming in general and specifically in California by its current Governor Schwarzenegger. Historical icons of the “savage” and of Indians as “uncivilized” are examined for their implications regarding Native nations’ ability for self-determination and the proceeds of Indian gaming in California. Half-truths and outright lies are identified as perpetrated by the government, and the governor, for specific purposes of denying full gaming and sovereignty rights of Native nations or taking too much revenue as a proxy for taxes. Hypocritical and discriminatory practices toward mainstream gaming are also compared. The governor’s latest use of inflammatory language is exposed as political trickery and viewed as attempts to suppress highly successful Indian gaming operations.
The Promise of Title IX
Authors: Mertz Norma T.
Published: October 2006

Using statistical data collected during a 30-year period, the article reports on the significant movement of females into all of the line administrative positions in the largest school districts in the country (by student population) since the passage of Title IX with one notable exception, that of superintendent. The position of superintendent remains, as it was in 1972, overwhelmingly male. In terms of the promise of Title IX to redress gender inequity in school administration, it would appear to have been successful save for that one persistent, resistant, powerful top spot.
The Practice of Service Learning in Local School-Community Contexts
Authors: Koliba Christopher J. , Campbell Erica K. , Shapiro Carolyn
Published: October 2006

In this article, the authors set out to examine the ways in which service learning is practiced, perceived, and sustained in school settings. Drawing on extensive qualitative case studies, the authors highlight three cases of schools at varying levels of integration of service into their curriculum. Their history of offering service learning is summarized. Participant perceptions regarding the role of service learning in student learning and concerns regarding the relationship between service learning and student academic achievement are explored. The authors conclude that service learning is practiced amidst a series of complex, and often times conflicting, assumptions regarding the aims of education and the proper formats through which student achievement should be assessed.
Charter Schools, Teacher Labor Market Deregulation, and Teacher Quality
Authors: Baker Bruce D. , Dickerson Jill L.
Published: October 2006

This study uses teacher-level data from the Schools and Staffing Survey of 1999 to test whether teachers in charter schools have stronger academic backgrounds than their peers working in conventional public schools and whether state regulatory policies are associated with differences between public and public charter school teachers. Specifically, the authors estimate whether school type (public, public charter, independent private, private Catholic) is associated with the likelihood that a teacher attended a highly or most competitive undergraduate college. They find compelling evidence both that charter schools generally hire more teachers from more competitive undergraduate institutions than do conventional public schools and, furthermore, that relaxation of state teacher certification policies for charter schools increases the likelihood that charter schools hire teachers from more competitive undergraduate institutions. Findings are highly dependent on supply of teachers from competitive undergraduate institutions.
Student Reactions to Being Wrongly Informed of Failing a High-Stakes Test
Authors: Cornell Dewey G. , Krosnick Jon A. , Chang LinChiat
Published: October 2006

How do students react to being told that they have failed a test required for high school graduation? In 2000, 7,989 students were wrongly informed that they had failed the Minnesota Basic Standards Test in mathematics. The authors conducted a survey of 911 of these students to assess the psychosocial impact of this event. More than 80% of students reported that they increased studying, and nearly half reduced their extracurricular activities. Students reported a range of adverse emotional reactions, with more than 80% reporting that they felt depressed, worried, or embarrassed. About half said that they felt stupid and less proud of themselves. About 4% reported that they dropped out of school as a result of being told that they failed the examination. These findings point to the largely unaddressed need to study student reactions to failing high-stakes tests.