bluuebunny/crossref_metadata_2025 huggingface dataset:
FUNCTIONS OF OVERSTEP CHEMISTRY CALCULATION OXYGEN IN HIGH TcCOPPER OXIDE SUPERCONDUCTORS
Authors: CHEN YU , HUANG XINMING , WANG JIANWU
Published: October 2005

This paper studies the functions of overstep chemistry calculation oxygen δ in high Tccopper oxide superconductors and analyzes the relative experiments' results. It is believed that the function of overstep chemistry calculation oxygen in Y series high Tccopper oxide superconductors is to adjust the change of effective electric charge P on the [Cu-O]plink or [Cu-O]Pplane and this affects the bonding intensity on the CuO2plane, which in turn, adjusts the Y series high oxide superconductor's Tc.
BOND-LENGTH FLUCTUATIONS IN TRANSITION-METAL OXIDES
Authors: GOODENOUGH J. B. , RIVADULLA F.
Published: October 2005

The several origins of bond-length fluctuations found in transition-metal oxides are illustrated by specific examples. Special emphasis is given to the first-order character of the transition from localized to itinerant electronic behavior, which occurs where the operative bonding has a double-well potential energy. This first-order transition is a general phenomenon applying to single-valent and mixed-valent systems with either cation-cation or cation-anion-cation operative bonding. A transition from bond-length fluctuations to long-range ordering of the bond character is found below a Ttwhere Ttis too low for phase separation by atomic diffusion. Where Jahn–Teller site distortions or low-spin to higher-spin site excitations are also present, competitive bond ordering can give complex phase diagrams.
MULTIPOLE MOMENTS OF FRACTAL DISTRIBUTION OF CHARGES
Authors: TARASOV VASILY E.
Published: October 2005

In this paper we consider the electric multipole moments of fractal distribution of charges. To describe fractal distribution, we use the fractional integrals. The fractional integrals are considered as approximations of integrals on fractals. In the paper we compute the electric multipole moments for homogeneous fractal distribution of charges.
EVOLUTIONARY DYNAMICS IN CARCINOGENESIS
Authors: GATENBY ROBERT A. , VINCENT THOMAS L. , GILLIES ROBERT J.
Published: October 2005

We have previously demonstrated intra- and extra-cellular factors that govern somatic evolution of the malignant phenotype can be modeled through evolutionary game theory, a mathematical approach that analyzes phenotypic adaptation to in-vivo environmental selection forces. Here we examine the global evolutionary dynamics that control evolutionary dynamics explicitly addressing conflicting data and hypothesis regarding the relative importance of the mutator phenotype and microenvironment controls.

We find evolution of invasive cancer follows a biphasic pattern. The first phase occurs within normal tissue, which possesses a remarkable adaptive landscape that permits non-competitive coexistence of multiple cellular populations but renders it vulnerable to invasion. When random genetic mutations produce a fitter phenotype, self-limited clonal expansion is observed — equivalent to a polyp or nevus. This step corresponds to tumor initiation in classical skin carcinogenesis experiments because the mutant population deforms the adaptive landscape resulting in the emergence of unoccupied fitness peaks — a premalignant configuration because, over time, extant cellular populations will tend to evolve toward available fitness maxima forming an invasive cancer. We demonstrate that this phase is governed by intracellular processes, such as the mutation rate, that promote phenotypic diversity and environmental factors that control cellular selection and population growth. These results provide an integrative model of carcinogenesis that incorporates cell-centric approaches such as the mutator phenotype hypothesis with the critical role of the environmental demonstrated by Bissell and others. The biphasic dynamics of carcinogenesis give a quantitative framework of understanding for the empirically observed initiation and promotion/progression stages in skin carcinogenesis experimental models.
Regulation of homocysteine-induced MMP-9 by ERK1/2 pathway
Authors: Moshal Karni S. , Sen Utpal , Tyagi Neetu , Henderson Brooke , Steed Mesia , Ovechkin Alexander V. , Tyagi Suresh C.
Published: October 2005

Homocysteine (Hcy) induces matrix metalloproteinase (MMP)-9 in microvascular endothelial cells (MVECs). We hypothesized that the ERK1/2 signaling pathway is involved in Hcy-mediated MMP-9 expression. In cultured MVECs, Hcy induced activation of ERK, which was blocked by PD-98059 and U0126 (MEK inhibitors). Pretreatment with BAPTA-AM, staurosporine (PKC inhibitor), or Gö6976 (specific inhibitor for Ca2+-dependent PKC) abrogated ERK phosphorylation, suggesting the role of Ca2+ and Ca2+-dependent PKC in Hcy-induced ERK activation. ERK phosphorylation was suppressed by pertussis toxin (PTX), suggesting the involvement of G protein-coupled receptors (GPCRs) in initiating signal transduction by Hcy and leading to ERK activation. Pretreatment of MVECs with genistein, BAPTA-AM, or thapsigargin abrogated Hcy-induced ERK activation, suggesting the involvement of the PTK pathway in Hcy-induced ERK activation, which was mediated by intracellular Ca2+ pool depletion. ERK activation was attenuated by preincubation with N-acetylcysteine (NAC) and SOD, suggesting the role of oxidation in Hcy-induced ERK activation. Pretreatment with an ERK1/2 blocker (PD-98059), staurosporine, folate, or NAC modulated Hcy-induced MMP-9 activation as measured using zymography. Our results provide evidence that Hcy triggers the PTX-sensitive ERK1/2 signaling pathway, which is involved in the regulation of MMP-9 in MVECs.
Type II skeletal myofibers possess unique properties that potentiate mitochondrial H2O2 generation
Authors: Anderson Ethan J. , Neufer P. Darrell
Published: October 2005

Mitochondrial dysfunction is implicated in a number of skeletal muscle pathologies, most notably aging-induced atrophy and loss of type II myofibers. Although oxygen-derived free radicals are thought to be a primary cause of mitochondrial dysfunction, the underlying factors governing mitochondrial superoxide production in different skeletal myofiber types is unknown. Using a novel in situ approach to measure H2O2 production (indicator of superoxide formation) in permeabilized rat skeletal muscle fiber bundles, we found that mitochondrial free radical leak (H2O2 produced/O2 consumed) is two- to threefold higher ( P < 0.05) in white (WG, primarily type IIB fibers) than in red (RG, type IIA) gastrocnemius or soleus (type I) myofibers during basal respiration supported by complex I (pyruvate + malate) or complex II (succinate) substrates. In the presence of respiratory inhibitors, maximal rates of superoxide produced at both complex I and complex III are markedly higher in RG and WG than in soleus muscle despite ∼50% less mitochondrial content in WG myofibers. Duplicate experiments conducted with ±exogenous superoxide dismutase revealed striking differences in the topology and/or dismutation of superoxide in WG vs. soleus and RG muscle. When normalized for mitochondrial content, overall H2O2 scavenging capacity is lower in RG and WG fibers, whereas glutathione peroxidase activity, which is largely responsible for H2O2 removal in mitochondria, is similar in all three muscle types. These findings suggest that type II myofibers, particularly type IIB, possess unique properties that potentiate mitochondrial superoxide production and/or release, providing a potential mechanism for the heterogeneous development of mitochondrial dysfunction in skeletal muscle.
Decline of contractility during ischemia-reperfusion injury: actin glutathionylation and its effect on allosteric interaction with tropomyosin
Authors: Chen Frank C. , Ogut Ozgur
Published: October 2005

The severity and duration of ischemia-reperfusion injury is hypothesized to play an important role in the ability of the heart subsequently to recover contractility. Permeabilized trabeculae were prepared from a rat model of ischemia-reperfusion injury to examine the impact on force generation. Compared with the control perfused condition, the maximum force (Fmax) per cross-sectional area and the rate of tension redevelopment of Ca2+-activated trabeculae fell by 71% and 44%, respectively, during ischemia despite the availability of a high concentration of ATP. The reduction in Fmax with ischemia was accompanied by a decline in fiber stiffness, implying a drop in the absolute number of attached cross bridges. However, the declines during ischemia were largely recovered after reperfusion, leading to the hypothesis that intrinsic, reversible posttranslational modifications to proteins of the contractile filaments occur during ischemia-reperfusion injury. Examination of thin-filament proteins from ischemic or ischemia-reperfused hearts did not reveal proteolysis of troponin I or T. However, actin was found to be glutathionylated with ischemia. Light-scattering experiments demonstrated that glutathionylated G-actin did not polymerize as efficiently as native G-actin. Although tropomyosin accelerated the time course of native and glutathionylated G-actin polymerization, the polymerization of glutathionylated G-actin still lagged native G-actin at all concentrations of tropomyosin tested. Furthermore, cosedimentation experiments demonstrated that tropomyosin bound glutathionylated F-actin with significantly reduced cooperativity. Therefore, glutathionylated actin may be a novel contributor to the diverse set of posttranslational modifications that define the function of the contractile filaments during ischemia-reperfusion injury.
Fatty acid transport and metabolism in HepG2 cells
Authors: Guo Wen , Huang Nasi , Cai Jun , Xie Weisheng , Hamilton James A.
Published: October 2005

The mechanism(s) of fatty acid uptake by liver cells is not fully understood. We applied new approaches to address long-standing controversies of fatty acid uptake and to distinguish diffusion and protein-based mechanisms. Using HepG2 cells containing an entrapped pH-sensing fluorescence dye, we showed that the addition of oleate (unbound or bound to cyclodextrin) to the external buffer caused a rapid (seconds) and dose-dependent decrease in intracellular pH (pHin), indicating diffusion of fatty acids across the plasma membrane. pHinreturned to its initial value with a time course (in min) that paralleled the metabolism of radiolabeled oleate. Preincubation of cells with the inhibitors phloretin or triacsin C had no effect on the rapid pHindrop after the addition of oleate but greatly suppressed pHinrecovery. Using radiolabeled oleate, we showed that its esterification was almost completely inhibited by phloretin or triacsin C, supporting the correlation between pHinrecovery and metabolism. We then used a dual-fluorescence assay to study the interaction between HepG2 cells and cis-parinaric acid (PA), a naturally fluorescent but slowly metabolized fatty acid. The fluorescence of PA increased rapidly upon its addition to cells, indicating rapid binding to the plasma membrane; pHindecreased rapidly and simultaneously but did not recover within 5 min. Phloretin had no effect on the PA-mediated pHindrop or its slow recovery but decreased the absolute fluorescence of membrane-bound PA. Our results show that natural fatty acids rapidly bind to, and diffuse through, the plasma membrane without hindrance by metabolic inhibitors or by an inhibitor of putative membrane-bound fatty acid transporters.
Adenoviral PR39 improves blood flow and myocardial function in a pig model of chronic myocardial ischemia by enhancing collateral formation
Authors: Post Mark J. , Sato Kaori , Murakami Masahiro , Bao Jialin , Tirziu Daniela , Pearlman Justin D. , Simons Michael
Published: October 2005

Angiogenic therapy with individual growth factors or “master switch” genes is being evaluated for treatment of advanced coronary artery disease. In this study, we investigated the efficacy and mechanism of PR39, a gene capable of activating VEGF and fibroblast growth factor (FGF)-2-dependent pathways. PR39 enhances hypoxia-inducible factor-1α (HIF-1α)-dependent gene expression by selectively inhibiting proteasome degradation of this transcription factor. In addition, PR39 also stimulates expression of the FGF receptors (FGFR)-1 and syndecan-4. In a pig model of chronic myocardial ischemia, we used angiography, MRI, and microsphere regional blood flow to evaluate the efficacy of intramyocardial adenoviral protein arginine-rich peptide (Ad-PR39) injections. Ad-PR39 improved collateral scores, regional perfusion, and regional function in a dose-dependent manner. Local VEGF, VEGFR-1, VEGFR-2, syndecan, and FGFR-1 levels were 16–75% upregulated after Ad-PR39 injections as assessed by real-time PCR, suggesting upregulation of VEGF and FGF pathways. PR39 is an angiogenic peptide that improves perfusion and function of ischemic myocardium, at least in part, through collateral formation. The dual mechanism, i.e., stimulation of HIF-1α and FGF receptor expression, likely accounts for the functional benefits of PR39.
Role of nitrosyl factors in the hindlimb vasodilation elicited by baroreceptor afferent nerve stimulation
Authors: Possas Olga S. , Johnson Alan Kim , Lewis Stephen J.
Published: October 2005

This study determined whether electrical stimulation (ES) of the baroreceptor afferent fibers in the aortic depressor nerve (ADN) produces hindlimb vasodilation in pentobarbital-anesthetized rats via the release of nitric oxide (NO)-containing (nitrosyl) factors from NO synthase-positive lumbar sympathetic nerve terminals. ES of the ADN (1–10 Hz for 15 s) produced frequency-dependent reductions in mean arterial blood pressure (MAP) and mesenteric and hindlimb vascular resistance (MR and HLR, respectively). The falls in resistance were substantially smaller in hindlimb beds in which the ipsilateral lumbar sympathetic chain had been transected 7–10 days previously. The maximal falls in MR and hindquarter vascular resistance (HQR) produced by 1- to 10-Hz ES of the ADN were unaffected by the specific inhibitor of neuronal NO synthase 7-nitroindazole (7-NI, 45 mg/kg iv). However, the total falls in HQR (mmHg·kHz−1·s) produced by these stimuli were significantly diminished by 7-NI, whereas the total falls in MR were not affected. Four successive episodes of 10-Hz ES produced equivalent reductions in MAP, MR, and HQR. The peak changes in these parameters were not affected by 7-NI. However, the total falls in HQR progressively diminished with each successive stimulus, whereas the total falls in MR remained unchanged. These results provide evidence that the hindlimb vasodilation produced by ES of baroreceptor afferents within the ADN may involve the activation of postganglionic lumbar sympathetic vasodilator fibers, which release newly synthesized and preformed nitrosyl factors.
On the modeling of breath-by-breath oxygen uptake kinetics at the onset of high-intensity exercises: simulated annealing vs. GRG2 method
Authors: Bernard Olivier , Alata Olivier , Francaux Marc
Published: October 2005

Modeling in the time domain, the non-steady-state O2 uptake on-kinetics of high-intensity exercises with empirical models is commonly performed with gradient-descent-based methods. However, these procedures may impair the confidence of the parameter estimation when the modeling functions are not continuously differentiable and when the estimation corresponds to an ill-posed problem. To cope with these problems, an implementation of simulated annealing (SA) methods was compared with the GRG2 algorithm (a gradient-descent method known for its robustness). Forty simulated V̇o2 on-responses were generated to mimic the real time course for transitions from light- to high-intensity exercises, with a signal-to-noise ratio equal to 20 dB. They were modeled twice with a discontinuous double-exponential function using both estimation methods. GRG2 significantly biased two estimated kinetic parameters of the first exponential (the time delay td1 and the time constant τ1) and impaired the precision (i.e., standard deviation) of the baseline A0, td1, and τ1 compared with SA. SA significantly improved the precision of the three parameters of the second exponential (the asymptotic increment A2, the time delay td2, and the time constant τ2). Nevertheless, td2 was significantly biased by both procedures, and the large confidence intervals of the whole second component parameters limit their interpretation. To compare both algorithms on experimental data, 26 subjects each performed two transitions from 80 W to 80% maximal O2 uptake on a cycle ergometer and O2 uptake was measured breath by breath. More than 88% of the kinetic parameter estimations done with the SA algorithm produced the lowest residual sum of squares between the experimental data points and the model. Repeatability coefficients were better with GRG2 for A1 although better with SA for A2 and τ2. Our results demonstrate that the implementation of SA improves significantly the estimation of most of these kinetic parameters, but a large inaccuracy remains in estimating the parameter values of the second exponential.
Removal of ovarian hormones from mature mice detrimentally affects muscle contractile function and myosin structural distribution
Authors: Moran Amy L. , Warren Gordon L. , Lowe Dawn A.
Published: October 2005

The purposes of this study were to determine the effects of ovarian hormone removal on force-generating capacities and contractile proteins in soleus and extensor digitorum longus (EDL) muscles of mature female mice. Six-month-old female C57BL/6 mice were randomly assigned to either an ovariectomized (OVX; n = 13) or a sham-operated (sham; n = 13) group. In vitro contractile function of soleus and EDL muscles were determined 60 days postsurgery. Total protein and contractile protein contents were quantified, and electron paramagnetic resonance (EPR) spectroscopy was used to determine myosin structural distribution during contraction. OVX mice weighed 15% more than sham mice 60 days postsurgery, and soleus and EDL muscle masses were 19 and 15% greater in OVX mice, respectively ( P ≤ 0.032). Soleus and EDL muscles from OVX mice generated less maximal isometric force than did those from sham mice [soleus: 0.27 (SD 0.04) vs. 0.22 N·cm·mg−1 (SD 0.04); EDL: 0.33 (SD 0.04) vs. 0.27 N·cm·mg−1 (SD 0.04); P ≤ 0.006]. Total and contractile protein contents of soleus and EDL muscles were not different between OVX and sham mice ( P ≥ 0.242), indicating that the quantity of contractile machinery was not affected by removing ovarian hormones. EPR spectroscopy showed that the fraction of strong-binding myosin during contraction was 15% lower in EDL muscles from OVX mice compared with shams [0.277 (SD 0.039) vs. 0.325 (SD 0.020); P = 0.004]. These results indicate that the loss of ovarian hormones has detrimental effects on skeletal muscle force-generating capacities that can be explained by altered actin-myosin interactions.
Chronic antioxidant enzyme mimetic treatment differentially modulates hyperthermia-induced liver HSP70 expression with aging
Authors: Zhang Hannah J. , Doctrow Susan R. , Oberley Larry W. , Kregel Kevin C.
Published: October 2005

One postulated mechanism for the reduction in stress tolerance with aging is a decline in the regulation of stress-responsive genes, such as inducible heat shock protein 72 (HSP70). Increased levels of oxidative stress are also associated with aging, but it is unclear what impact a prooxidant environment might have on HSP70 gene expression. This study utilized a superoxide dismutase/catalase mimetic (Eukarion-189) to evaluate the impact of a change in redox environment on age-related HSP70 responses to a physiologically relevant heat challenge. Results demonstrate that liver HSP70 mRNA and protein levels are reduced in old compared with young rats at selected time points over a 48-h recovery period following a heat-stress protocol. While chronic systemic administration of Eukarion-189 suppressed hyperthermia-induced liver HSP70 mRNA expression in both age groups, HSP70 protein accumulation was blunted in old rats but not in their young counterparts. These data suggest that a decline in HSP70 mRNA levels may be responsible for the reduction in HSP70 protein observed in old animals after heat stress. Furthermore, improvements in redox status were associated with reduced HSP70 mRNA levels in both young and old rats, but differential effects were manifested on protein expression, suggesting that HSP70 induction is differentially regulated with aging. These findings highlight the integrated mechanisms of stress protein regulation in eukaryotic organisms responding to environmental stress, which likely involve interactions between a wide range of cellular signals.
On some equations related to derivations in rings
Authors: Vukman Joso , Kosi-Ulbl Irena
Published: October 2005

Let m and n be positive integers with m + n ≠ 0, and let R be an (m + n + 2)!‐torsion free semiprime ring with identity element. Suppose there exists an additive mapping D : R → R, such that D(xm+n+1) = (m + n + 1)xmD(x)xn is fulfilled for all x ∈ R, then D is a derivation which maps R into its center.
On the power‐commutative kernel of locally nilpotent groups
Authors: Delizia Costantino , Nicotera Chiara
Published: October 2005

We define the power‐commutative kernel of a group. In particular, we describe the power‐commutative kernel of locally nilpotent groups, and of finite groups having a nontrivial center.
Intuitionistic H‐fuzzy relations
Authors: Hur Kul , Jang Su Youn , Kang Hee Won
Published: October 2005

We introduce the category IRel(H) consisting of intuitionistic fuzzy relational spaces on sets and we study structures of the category IRel(H) in the viewpoint of the topological universe introduced by Nel. Thus we show that IRel(H) satisfies all the conditions of a topological universe over Set except the terminal separator property and IRel(H) is cartesian closed over Set.
Best approximations for the Laguerre‐type Weierstrass transform on [0, ∞[×ℝ
Authors: Jebbari E. , Soltani F.
Published: October 2005

We use reproducing kernel Hilbert spaces to give the best approximation for Laguerre‐type Weierstrass transform. Estimates of extremal functions are also discussed.
Asymptotic behaviour of solutions of nonlinear delay difference equations in Banach spaces
Authors: Kisiolek Anna , Kubiaczyk Ireneusz
Published: October 2005

We consider the second‐order nonlinear difference equations of the form Δ(rn−1Δxn−1) + pnf(xn − k) = hn. We show that there exists a solution (xn), which possesses the asymptotic behaviour , a, b∈ℝ. In this paper, we extend the results of Agarwal (1992), Dawidowski et al. (2001), Drozdowicz and Popenda (1987), M. Migda (2001), and M. Migda and J. Migda (1988). We suppose that f has values in Banach space and satisfies some conditions with respect to the measure of noncompactness and measure of weak noncompactness.
Fixed point theory for Mönch‐type maps defined on closed subsets of Fréchet spaces: the projective limit approach
Authors: Agarwal Ravi P. , Dshalalow Jewgeni H. , O′Regan Donal
Published: October 2005

New Leray‐Schauder alternatives are presented for Mönch‐type maps defined between Fréchet spaces. The proof relies on viewing a Fréchet space as the projective limit of a sequence of Banach spaces.
Exponentiating derivations of quasi ∗‐algebras: possible approaches and applications
Authors: Bagarello F. , Inoue A. , Trapani C.
Published: October 2005

The problem of exponentiating derivations of quasi ∗‐algebras is considered in view of applying it to the determination of the time evolution of a physical system. The particular case where observables constitute a proper CQ∗‐algebra is analyzed.
Shannon entropy: axiomatic characterization and application
Authors: Chakrabarti C. G. , Chakrabarty Indranil
Published: October 2005

We have presented a new axiomatic derivation of Shannon entropy for a discrete probability distribution on the basis of the postulates of additivity and concavity of the entropy function. We have then modified Shannon entropy to take account of observational uncertainty.The modified entropy reduces, in the limiting case, to the form of Shannon differential entropy. As an application, we have derived the expression for classical entropy of statistical mechanics from the quantized form of the entropy.
Fractionated Low-Dose Radiation Exposure Leads to Accumulation of DNA Damage and Profound Alterations in DNA and Histone Methylation in the Murine Thymus
Authors: Pogribny Igor , Koturbash Igor , Tryndyak Volodymyr , Hudson Darryl , Stevenson Sandie M.L. , Sedelnikova Olga , Bonner William , Kovalchuk Olga
Published: October 2005

Thymus, an important component of hematopoietic tissue, is a well-documented “target” of radiation carcinogenesis. Both acute and fractionated irradiation result in a high risk of leukemia and thymic lymphoma. However, the exact mechanisms underlying radiation-induced predisposition to leukemia and lymphoma are still unknown, and the contributions of genetic and epigenetic mechanisms in particular have yet to be defined. Global DNA hypomethylation is a well-known characteristic of cancer cells. Recent studies have also shown that tumor cells undergo prominent changes in histone methylation, particularly a substantial loss of trimethylation of histone H4-Lys20 and demethylation of genomic DNA. These losses are considered a universal marker of malignant transformation. In the present study, we investigated the effect of low-dose radiation exposure on the accumulation of DNA lesions and alterations of DNA methylation and histone H4-Lys20 trimethylation in the thymus tissue using an in vivo murine model. For the first time, we show that fractionated whole-body application of 0.5 Gy X-ray leads to decrease in histone H4-Lys20 trimethylation in the thymus. The loss of histone H4-Lys20 trimethylation was accompanied by a significant decrease in global DNA methylation as well as the accumulation of DNA damage as monitored by persistence of histone γH2AX foci in the thymus tissue of mice exposed to fractionated irradiation. Altered DNA methylation was associated with reduced expression of maintenance (DNMT1) and, to a lesser extent, de novo DNA methyltransferase DNMT3a in exposed animals. Expression of another de novo DNA methyltransferase DNMT3b was decreased only in males. Irradiation also resulted in ∼20% reduction in the levels of methyl-binding proteins MeCP2 and MBD2. Our results show the involvement of epigenetic alterations in radiation-induced responses in vivo. These changes may play a role in genome destabilization that ultimately leads to cancer.
A Mechanism of COOH–Terminal Binding Protein–Mediated Repression
Authors: Meloni Alison R. , Lai Chun-Hsiang , Yao Tso-Pang , Nevins Joseph R.
Published: October 2005

The E2F4 and E2F5 proteins specifically associate with the Rb-related p130 protein in quiescent cells to repress transcription of various genes encoding proteins important for cell growth. A series of reports has provided evidence that Rb-mediated repression involves both histone deacetylase (HDAC)–dependent and HDAC-independent events. Our previous results suggest that one such mechanism for Rb-mediated repression, independent of recruitment of HDAC, involves the recruitment of the COOH-terminal binding protein (CtBP) corepressor, a protein now recognized to play a widespread role in transcriptional repression. We now find that CtBP can interact with the histone acetyltransferase, cyclic AMP–responsive element–binding protein (CREB) binding protein, and inhibit its ability to acetylate histone. This inhibition is dependent on a NH2-terminal region of CtBP that is also required for transcription repression. These results thus suggest two complementary mechanisms for E2F/p130-mediated repression that have in common the control of histone acetylation at target promoters.
The Role of the BRCA1 Tumor Suppressor in DNA Double-Strand Break Repair
Authors: Zhang Junran , Powell Simon N.
Published: October 2005

The tumor suppressor gene BRCA1 was cloned in 1994 based on its linkage to early-onset breast and ovarian cancer. Although the BRCA1 protein has been implicated in multiple cellular functions, the precise mechanism that determines its tumor suppressor activity is not defined. Currently, the emerging picture is that BRCA1 plays an important role in maintaining genomic integrity by protecting cells from double-strand breaks (DSB) that arise during DNA replication or after DNA damage. The DSB repair pathways available in mammalian cells are homologous recombination and nonhomologous end-joining. BRCA1 function seems to be regulated by specific phosphorylations in response to DNA damage and we will focus this review on the roles played by BRCA1 in DNA repair and cell cycle checkpoints. Finally, we will explore the idea that tumor suppression by BRCA1 depends on its control of DNA DSB repair, resulting in the promotion of error-free and the inhibition of error-prone recombinational repair.
The Clinical Dementia Rating Sum of Box Score in Mild Dementia
Authors: Lynch C.A. , Walsh C. , Blanco A. , Moran M. , Coen R.F. , Walsh J.B. , Lawlor B.A.
Published: October 2005

Background: Making an early diagnosis of dementia is becoming increasingly important, but is difficult in practice. The Clinical Dementia Rating (CDR) scale is a widely used dementia staging instrument, yielding a global score and a summated score (sum of box score). This study examines the utility of the CDR sum of box score, rather than the CDR global score, in making a diagnosis of early dementia. Objective: To determine whether the CDR sum of box score is predictive of an ICD-10 diagnosis of dementia in cases with mild cognitive deficits. Methods: Clinical data recorded on our Memory Clinic database were examined for all patients seen over a 6-year period. Data were extracted from 276 first visits in which patients had scored 0.5 using the CDR global score. We examined the relationship between CDR sum of box score and consensus diagnosis of dementia using logistic regression. Results: We found that increased CDR sum of box score was significantly associated with a higher probability of being assigned an ICD-10 diagnosis of dementia (p < 0.001). The odds ratio for the coefficient of CDR sum of box was 2.3 (95% CI 1.7–3.1), indicating that the likelihood of being diagnosed as having dementia increased by a factor of 2.3 for every point increase on the CDR sum of box score. Conclusion: These findings indicate that the CDR sum of box score provides additional information to the CDR global score in mild cases. The CDR sum of box score is a helpful indicator in making/excluding a diagnosis of dementia in people with mild cognitive deficits.
A Simple and Effective Regimen for Prevention of Radial Artery Spasm during Coronary Catheterization
Authors: Chen Chih-Wei , Lin Chin-Lon , Lin Tin-Kwang , Lin Chih-Da
Published: October 2005

Radial artery spasm occurs frequently during the transradial approach for coronary catheterization. Premedications with nitroglycerin and verapamil have been documented to be effective in preventing radial spasms. Verapamil is relatively contraindicated for some patients with left ventricular dysfunction, hypotension and bradycardia. We would like to know whether nitroglycerin alone is sufficient for the prevention of radial artery spasm. We conducted a randomized controlled trial to compare the spasmolytic effect between heparin alone, heparin plus nitroglycerin and heparin plus nitroglycerin and varapamil during transradial cardiac catheterization. In this study, a total of 406 patients underwent transradial cardiac catheterization and intervention. After successful cannulation and sheath insertion of radial arteries, 133 patients in group A received 3,000 units of heparin, 100 µg of nitroglycerin and 1.25 mg of verapamil via sheath, 135 patients in group B received 3,000 units of heparin and 100 µg of nitroglycerin, and 93 patients in group C received 3,000 units of heparin. Five patients in group A (3.8%), 6 patients in group B (4.4%) and 19 patients in group C (20.4%) showed radial spasms. There is no statistically significant difference between groups A and B (p = 0.804), but there are strong statistically significant differences between groups A and C (p = 0.001) and groups B and C (p = 0.003). Intra-arterial premedication with 100 µg nitroglycerin and 3,000 units of heparin is effective in preventing radial spasms during transradial cardiac catheterization.
Free Androgen Index Is Superior to Total Testosterone for Short-Term Assessment of the Gonadal Axis after Renal Transplantation
Authors: Reinhardt Walter , Patschan Daniel , Pietruck Frank , Philipp Thomas , Janssen Onno E. , Mann Klaus , Jockenhövel Friedrich , Witzke Oliver
Published: October 2005

Objective: Recent studies have assessed gonadal function in association with different immunosuppressive drugs in transplanted patients mainly relying on the measurement of total testosterone. It is the aim of this study to assess the short-term changes of the hypothalamic-pituitary-gonadal axis following renal transplantation using the free androgen index (FAI). Patients and Methods: The sequential changes in total testosterone, sex hormone-binding globulin (SHBG), gonadotropin and prolactin concentrations were measured in 22 male patients before and after 1–3 days, and 1, 2 and 3 weeks following renal transplantation. Results: Total testosterone and SHBG concentrations dropped significantly after transplantation (total testosterone: baseline: 15.2 ± 1.6 nmol/l vs. 1 week: 7.9 ± 0.8 nmol/l vs. 2 weeks: 9.8 ± 0.9 nmol/l, SHBG: baseline: 29.9 ± 3.2 nmol/l vs. 1 week: 19.9 ± 2.1 nmol/l, 2 weeks: 18.9 ± 2.4 nmol/l, p < 0.01). FAI decreased significantly after day 1–3 returning to values near baseline thereafter (baseline: 60 ± 9% vs. day 1–3: 38 ± 6%, 2 weeks: 61 ± 7%; p < 0.01). There was a significant positive correlation between FAI and renal function. Conclusion: Measurement of the free androgen index is superior to total testosterone for assessment of the pituitary-gonadal axis in the first weeks after renal transplantation.
Long-Term Effect of Intravenous Thrombolytic Therapy in Acute Stroke: Responder Analysis versus Uniform Analysis of Excellent Outcome
Authors: Thomassen Lars , Waje-Andreassen Ulrike , Naess Halvor , Elvik May-Karin , Russell David
Published: October 2005

Background: Knowledge regarding functional improvement over time and long-term outcome after intravenous thrombolysis in acute ischaemic stroke is limited. The aim of this study was to compare a uniform assessment of outcome with an assessment taking the baseline stroke severity into account (responder analysis). Methods: Fifty-seven patients were assessed with the modified Rankin Scale at 3, 6 and 12 months and a comparison was made between a uniform assessment and a responder analysis of excellent outcome. Results: Between 3 and 12 months, 74% of the patients had a stable functional outcome and 22% improved. Excellent outcome at 12 months was similar in the uniform analysis (37%) and the responder analysis (35%). The individual patients having an excellent outcome differed, however, using the two methods. Using a responder analysis the number of patients with excellent outcome decreased in mild stroke patients by 40%, but increased in severe stroke patients by 43%. Conclusions: Short-term outcome is sustained at 12 months, but major improvement does not occur between 3 and 12 months. A responder analysis of long-term excellent outcome provided a balanced measure of outcome reflecting the drug-related potential of improvement in all stroke severity subgroups, whereas a uniform analysis provided a measure of outcome mainly in mild stroke patients. These results suggest that a responder analysis should be considered for the assessment of outcome after treatment for acute stroke.
Chemokines in Children With Heterozygous Familiar Hypercholesterolemia
Authors: Holven Kirsten B. , Damås Jan K. , Yndestad Arne , Wæhre Torgun , Ueland Thor , Halvorsen Bente , Heggelund Lars , Sandberg Wiggo J. , Semb Anne G. , Frøland Stig S. , Ose Leiv , Nenseter Marit S. , Aukrust Pål
Published: October 2005

Objective—Increasing data support the involvement of chemokines in atherogenesis. However, although several studies have shown increased chemokine levels in adult patients, the literature is virtually devoid of data on chemokines in children with hypercholesterolemia.

Methods and Results—We examined the gene expression of chemokines in peripheral blood mononuclear cells (PBMCs) from clinically healthy children with and without heterozygous familial hypercholesterolemia (FH). Our main findings were: (1) compared with healthy controls, PBMCs from FH children showed significantly higher mRNA levels of RANTES, but not of the other examined chemokines; (2) an opposite pattern was seen in adult FH subjects, with markedly enhanced expression of macrophage inflammatory peptide-1α, but not of RANTES; (3) this increased gene expression of RANTES in PBMCs from FH children seemed to reflect enhanced RANTES expression in monocytes but not in T cells; (4) FH children also had raised serum levels of neopterin, additionally suggesting monocyte/macrophage activation in these children; and (5) PBMCs from both FH children and controls showed enhanced release of interleukin 8 on RANTES stimulation in vitro.

Conclusions—Our findings support a role of inflammation also in the early stages of atherogenesis possibly involving monocyte-derived RANTES as an important mediator.
Role of Blood Cell–Associated AT1 Receptors in the Microvascular Responses to Hypercholesterolemia
Authors: Petnehazy Thomas , Stokes Karen Y. , Wood Katherine C. , Russell Janice , Granger D. Neil
Published: October 2005

Objective—Hypercholesterolemia elicits a proinflammatory and prothrombogenic phenotype in the microvasculature that is characterized by activation and adhesion of blood cells. The angiotensin II receptor-1 antagonist Losartan prevents the induction of these responses. The objective of this study was to determine the relative contributions of blood cell-associated versus endothelium-associated AT1a-R to these hypercholesterolemia-induced microvascular alterations.

Methods and Results—Leukocyte adhesion and emigration and platelet adhesion were quantified by intravital microscopy in postcapillary venules. C57Bl/6 mice were placed on a normal (ND) or high-cholesterol (HCD) diet for 2 weeks. AT1a-R bone marrow chimeras that express AT1a-R on the vessel wall but not blood cells and AT1a-R knockouts were placed on HCD. Venular shear rate was comparable in all groups. Platelet and leukocyte adhesion and leukocyte emigration were significantly increased in HCD mice versus ND. Leukocyte recruitment was significantly reduced in the HCD-AT1a-R bone marrow chimera group, whereas platelet adhesion remained at HCD levels. However, in HCD-AT1a-R knockout mice, platelet and leukocyte adhesion were reduced to ND levels.

Conclusions—These data indicate that the platelet-vessel wall adhesion elicited by hypercholesterolemia is mediated by AT1a-R engagement on the endothelial cell rather than the platelet, whereas leukocyte recruitment is mediated by blood cell-associated AT1a-R.
Europe and its Fertility: From Low to Lowest Low
Authors: Billari Francesco C.
Published: October 2005

This paper documents the fundamental changes in family formation that took place in Europe during the last two decades of the twentieth century, as well as some possible explanations for these changes. First, European youth have postponed key demographic events, and the latest-late pattern of transition to adulthood emerged in the South. Second, lowest-low fertility emerged during the 1990s in the same area, spreading quickly to Central and Eastern Europe. Policies and economic trends, long-standing cultural factors and ideational change interact in shaping change and differences. Macro-level factors in turn interact with micro-level ones to shape outcomes. The new demographic regime of Europe is thus likely to persist.
Relationship Power and Betrayal Experience as Predictors of Reactions to Infidelity
Authors: Berman Margit I. , Frazier Patricia A.
Published: October 2005

Explanations for sexual infidelity have been dominated by an evolutionary psychological theory of jealousy that finds its strongest support in research that employs a forced-choice hypothetical infidelity paradigm wherein participants imagine experiencing infidelity and choose whether sexual or emotional infidelity would be more distressing. Robust gender differences that support evolutionary psychological perspectives are consistently found using this paradigm, but recent work suggests that gender differences may be attenuated among actual infidelity victims. However, no research has used the forced-choice paradigm to compare real and hypothetical infidelity. This study uses this paradigm to compare reactions to imagined dating infidelity to those of infidelity victims. No gender differences are observed in response to the forced-choice question among victims of infidelity. Gender differences among participants who imagined infidelity are partially mediated by level of relationship power. Difficulties with the hypothetical forced-choice paradigm and implications for the evolutionary psychological theory of jealousy are discussed.
System-Justifying Beliefs and Psychological Well-Being: The Roles of Group Status and Identity
Authors: O’Brien Laurie T. , Major Brenda
Published: October 2005

This research examined the relationship between endorsing system-justifying beliefs and psychological well-being among individuals fromethnic groups that vary in social status. Systemjustifying beliefs are beliefs that imply that status in society is fair, deserved, and merited; examples of system-justifying beliefs in the United States include the beliefs that hard work pays off and that anyone can get ahead regardless of their group membership. We found that endorsing system-justifying beliefs was negatively related to psychological well-being among members of lowstatus groups who were highly identified with their group but positively related to well-being among members of low-status groups who were not highly identified with their ethnic group. In addition, we found that endorsing system-justifying beliefs was positively related to well-being among members of high-status groups, especially among members of high-status groups who were highly identified with the group.
Organization and Predictive Power of General and Relationship-Specific Attachment Models: One for All, and All for One?
Authors: Klohnen Eva C. , Weller Joshua A. , Luo Shanhong , Choe Mary
Published: October 2005

Given recent evidence for multiple attachment models, we examined the organization and predictive power of general and relationship-specific attachment representations in two samples using two distinct measures of attachment models. With regard to associations among relationship-specific models, peer models (romantic partner and friend) and parental models (mother and father) were more similar to each other than to any other models, and anxiety/self-model representations were more consistent across relationships than avoidance/other-model representations. With regard to links between general and specific models, romantic and friend models made the strongest and independent contributions to general models, and romantic relationship involvement moderated the importance of romantic models to general models. With regard to differential predictive power of multiple models, general, romantic partner, and mother attachment made unique contributions to well-being indicators; relationship outcomes, however, were only predicted by individuals’ corresponding relationship-specific models. Implications for the measurement and conceptualization of adult attachment are discussed.
Achievement Goals, Task Performance, and Interest: Why Perceived Goal Difficulty Matters
Authors: Senko Corwin , Harackiewicz Judith M.
Published: October 2005

In field studies, mastery goals, which focus on developing skill, often predict task interest but not actual performance. Performance-approach goals, which focus on outperforming others, instead often predict strong performance but not interest. Two experiments tested the hypothesis that these distinct goal effects trace to goal difficulty perceptions. In each study, participants assigned to a performance-approach goal perceived their goal to be harder, and therefore felt more performance pressure, than those assigned to a mastery goal. Among participants low in dispositional achievement orientation, this experience translated into lower task interest when pursuing the performanceapproach goal. However, participants in both studies also performed the activity better when pursuing this goal instead of a standard mastery goal, although this was not mediated by selfreported goal difficulty perceptions. Finally, further demonstrating the role of goal difficulty, a mastery goal manipulated to appear more difficult than a standard mastery goal produced effects matching the performance-approach goal.
Modified Carrageenan. 1. H-CarragPAM, a Novel Biopolymer-Based Superabsorbent Hydrogel
Authors: Hosseinzadeh H. , Pourjavadi A. , Mahdavinia G. R. , Zohuriaan-Mehr M. J.
Published: October 2005

A novel kappa-carrageenan (C)-based superabsorbing hydrogel was synthesized through graft copolymerization of acrylamide (AAm) onto a C substrate in the presence of a crosslinking agent. The crosslinked C-poly(AAm) polymer graft was partially hydrolyzed in alkaline medium to yield a superabsorbent resin, H-carragPAM. The resin structure was confirmed using FTIR spectroscopy. The variables of graft copolymerization (monomer, initiator, polysaccharide and crosslinker concentration, reaction temperature and time as well as stirrer speed) that affected on the ultimate water-swelling capacity were optimized. The time-temperature variation of the copolymerization was investigated in terms of the absence and presence of the atmospheric oxygen. Under optimized conditions, the maximum capacity of swelling in distilled water and saline (0.9wt% NaCl) were 1,465 and 121g/g, respectively. Since this hydrogel exhibited a very high absorptivity in saline, it may be referred to as low salt sensitive superabsorbent.
A New Class II Poly (ε-Caprolactone)-Silica Hybrid: Synthesis and In Vitro Apatite Forming Ability
Authors: Eglin David , Perry Carole C. , Ali Saad A. M.
Published: October 2005

The synthesis of a new class II poly(ε-caprolactone)-silica hybrid has been carried out using tin (II) 2-ethylhexanoate as the catalyst. Swelling behaviour, solid state 29 Si NMR and other techniques indicate the formation of interconnected organic-inorganic materials. An in vitro apatite forming ability test performed on this new class of material compared with an equivalent class I poly(ε-caprolactone)-silica sol-gel hybrid (identical silica content) showed the absence of apatite formation on the class II hybrid surface and calcium phosphate precipitation on the class I hybrid surface. This effect may be linked to less silicic acid being released in the simulated body fluid for the class II hybrid compared to the class I hybrid.
Different Paths to Different Feminisms? Bridging Multiracial Feminist Theory and Quantitative Sociological Gender Research
Authors: Harnois Catherine E.
Published: October 2005

This article examines the limitations of the sociological research on feminist identities and ideologies that ignores the intersection of race and gender. Drawing from multiracial feminist theorizing, the author asks, Is self-identification as feminist a biased indicator of the salience of feminism in African American women's lives? Do women's racial statuses mediate the relationship between particular life events and experiences and the extent to which they embrace feminism? and To what extent are racial differences important when considering what women understand feminism to be? To answer these questions, the author conducted multiple group analyses of structural equation models to analyze data from the 1996 General Social Survey. Her findings are consistent with multiracial feminist theories and suggest a need to rethink traditional approaches to feminist research so that women's differences are no longer marginalized.