bluuebunny/crossref_metadata_2025 huggingface dataset:
Biological models and genes of tumor reversion: Cellular reprogramming through
tpt1
/TCTP and
SIAH-1
Authors: Tuynder Marcel , Susini Laurent , Prieur Sylvie , Besse Stéphanie , Fiucci Giusy , Amson Robert , Telerman Adam
Published: November 2002

Tumor reversion is the process by which some cancer cells lose their malignant phenotype. This study was aimed at defining some of the molecular and phenotypic properties of this process. Biological models of tumor reversion were isolated from human leukemia and breast cancer cell lines by using the H-1 parvovirus as a selective agent. Differential gene expression analysis was performed between the parental malignant cells and their revertants or alternatively between these parental cells and their
SIAH-1
transfectant counterparts. These
SIAH-1
transfectants have a suppressed malignant phenotype and were used as a control for a viral-free system. Two hundred sixty-three genes were found to be either activated or inhibited during the reversion process, as confirmed by Northern blot analysis or quantitative PCR. Of these, 32% were differentially expressed in all systems, irrespective of whether parvovirus-selected,
SIAH-1
overexpressing, or
p53
mutant or wild-type cell lines were used, suggesting the existence of a universal mechanism underlying tumor reversion. Translationally Controlled Tumor Protein (
tpt1
/TCTP) has the strongest differential expression, down-regulated in the reversion of U937- and
SIAH-1
-overexpressing cells. Inhibition of TCTP expression by anti-sense cDNA or small interfering RNA molecules results in suppression of the malignant phenotype and in cellular reorganization, similar to the effect of SIAH-1. Hence, tumor reversion can be defined at the molecular level, not just as the reversal of malignant transformation, but as a biological process in its own right involving a cellular reprogramming mechanism, overriding genetic changes in cancer, by triggering an alternative pathway leading to suppression of tumorigenicity.
Conformational energetics of stable and metastable states formed by DNA triplet repeat oligonucleotides: Implications for triplet expansion diseases
Authors: Völker J. , Makube N. , Plum G. E. , Klump H. H. , Breslauer K. J.
Published: November 2002

We have embedded the hexameric triplet repeats (CAG)
6
and (CTG)
6
between two (GC)
3
domains to produce two 30-mer hairpins with the sequences d[(GC)
3
(CAG)
6
(GC)
3
] and d[(GC)
3
(CTG)
6
(GC)
3
]. This construct reduces the conformational space available to these repetitive DNA sequences. We find that the (CAG)
6
and (CTG)
6
repeats form stable, ordered, single-stranded structures. These structures are stabilized at 62°C by an average enthalpy per base of 1.38 kcal·mol
−1
for the CAG triplet and 2.87 kcal·mol
−1
for the CTG triplet, while being entropically destabilized by 3.50 cal·K
−1
·mol
−1
for the CAG triplet and 7.6 cal·K
−1
·mol
−1
for the CTG triplet. Remarkably, these values correspond, respectively, to 1/3 (for CAG) and 2/3 (for CTG) of the enthalpy and entropy per base values associated with Watson–Crick base pairs. We show that the presence of the loop structure kinetically inhibits duplex formation from the two complementary 30-mer hairpins, even though the duplex is the thermodynamically more stable state. Duplex formation, however, does occur at elevated temperatures. We propose that this thermally induced formation of a more stable duplex results from thermal disruption of the single-stranded order, thereby allowing the complementary domains to associate (perhaps via “kissing hairpins”). Our melting profiles show that, once duplex formation has occurred, the hairpin intermediate state cannot be reformed, consistent with our interpretation of kinetically trapped hairpin structures. The duplex formed by the two complementary oligonucleotides does not have any unusual optical or thermodynamic properties. By contrast, the very stable structures formed by the individual single-stranded triplet repeat sequences are thermally and thermodynamically unusual. We discuss this stable, triplet repeat, single-stranded structure and its interconversion with duplex in terms of triplet expansion diseases.
Combining mapping and arraying: An approach to candidate gene identification
Authors: Wayne M. L. , McIntyre L. M.
Published: November 2002

A combination of quantitative trait locus (QTL) mapping and microarray analysis was developed and used to identify 34 candidate genes for ovariole number, a quantitative trait, in
Drosophila melanogaster
. Ovariole number is related to evolutionary fitness, which has been extensively studied, but for which few
a priori
candidate genes exist. A set of recombinant inbred lines were assayed for ovariole number, and QTL analyses for this trait identified 5,286 positional candidate loci. Forty deletions spanning the QTL were employed to further refine the map position of genes contributing to variation in this trait between parental lines, with six deficiencies showing significant effects and reducing the number of positional candidates to 548. Parental lines were then assayed for expression differences by using Affymetrix microarray technology, and ANOVA was used to identify differentially expressed genes in these deletions. Thirty-four genes were identified that showed evidence for differential expression between the parental lines, one of which was significant even after a conservative Bonferroni correction. The list of potential candidates includes 5 genes for which previous annotations did not exist, and therefore would have been unlikely choices for follow-up from mapping studies alone. The use of microarray technology in this context allows an efficient, objective, quantitative evaluation of genes in the QTL and has the potential to reduce the overall effort needed in identifying genes causally associated with quantitative traits of interest.
Antiepileptic drugs and apoptotic neurodegeneration in the developing brain
Authors: Bittigau Petra , Sifringer Marco , Genz Kerstin , Reith Ellen , Pospischil Dana , Govindarajalu Suresh , Dzietko Mark , Pesditschek Stefanie , Mai Ingrid , Dikranian Krikor , Olney John W. , Ikonomidou Chrysanthy
Published: November 2002

Epilepsy is the most common neurological disorder of young humans. Each year 150,000 children in the United States experience their first seizure. Antiepileptic drugs (AEDs), used to treat seizures in children, infants, and pregnant women, cause cognitive impairment, microcephaly, and birth defects. The cause of unwanted effects of therapy with AEDs is unknown. Here we reveal that phenytoin, phenobarbital, diazepam, clonazepam, vigabatrin, and valproate cause apoptotic neurodegeneration in the developing rat brain at plasma concentrations relevant for seizure control in humans. Neuronal death is associated with reduced expression of neurotrophins and decreased concentrations of survival-promoting proteins in the brain. β-Estradiol, which stimulates pathways that are activated by neurotrophins, ameliorates AED-induced apoptotic neurodegeneration. Our findings present one possible mechanism to explain cognitive impairment and reduced brain mass associated with prenatal or postnatal exposure of humans to antiepileptic therapy.
Potentiation of serum response factor activity by a family of myocardin-related transcription factors
Authors: Wang Da-Zhi , Li Shijie , Hockemeyer Dirk , Sutherland Lillian , Wang Zhigao , Schratt Gerhard , Richardson James A. , Nordheim Alfred , Olson Eric N.
Published: November 2002

Myocardin is a SAP (SAF-A/B, Acinus, PIAS) domain transcription factor that associates with serum response factor (SRF) to potently enhance SRF-dependent transcription. Here we describe two myocardin-related transcription factors (MRTFs), A and B, that also interact with SRF and stimulate its transcriptional activity. Whereas myocardin is expressed specifically in cardiac and smooth muscle cells, MRTF-A and -B are expressed in numerous embryonic and adult tissues. In SRF-deficient embryonic stem cells, myocardin and MRTFs are unable to activate SRF-dependent reporter genes, confirming their dependence on SRF. Myocardin and MRTFs comprise a previously uncharacterized family of SRF cofactors with the potential to modulate SRF target genes in a wide range of tissues.
Analysis of optimality in natural and perturbed metabolic networks
Authors: Segrè Daniel , Vitkup Dennis , Church George M.
Published: November 2002

An important goal of whole-cell computational modeling is to integrate detailed biochemical information with biological intuition to produce testable predictions. Based on the premise that prokaryotes such as
Escherichia coli
have maximized their growth performance along evolution, flux balance analysis (FBA) predicts metabolic flux distributions at steady state by using linear programming. Corroborating earlier results, we show that recent intracellular flux data for wild-type
E. coli
JM101 display excellent agreement with FBA predictions. Although the assumption of optimality for a wild-type bacterium is justifiable, the same argument may not be valid for genetically engineered knockouts or other bacterial strains that were not exposed to long-term evolutionary pressure. We address this point by introducing the method of minimization of metabolic adjustment (MOMA), whereby we test the hypothesis that knockout metabolic fluxes undergo a minimal redistribution with respect to the flux configuration of the wild type. MOMA employs quadratic programming to identify a point in flux space, which is closest to the wild-type point, compatibly with the gene deletion constraint. Comparing MOMA and FBA predictions to experimental flux data for
E. coli
pyruvate kinase mutant PB25, we find that MOMA displays a significantly higher correlation than FBA. Our method is further supported by experimental data for
E. coli
knockout growth rates. It can therefore be used for predicting the behavior of perturbed metabolic networks, whose growth performance is in general suboptimal. MOMA and its possible future extensions may be useful in understanding the evolutionary optimization of metabolism.
Caspase activation and neuroprotection in caspase-3- deficient mice after
in vivo
cerebral ischemia and
in vitro
oxygen glucose deprivation
Authors: Le Dean A. , Wu Yongqin , Huang Zhihong , Matsushita Kohji , Plesnila Nikolaus , Augustinack Jean C. , Hyman Bradley T. , Yuan Junying , Kuida Keisuke , Flavell Richard A. , Moskowitz Michael A.
Published: November 2002

Caspase-3 is a major cell death effector protease in the adult and neonatal nervous system. We found a greater number and higher density of cells in the cortex of caspase-3
−/−
adult mice, consistent with a defect in developmental cell death. Caspase-3
−/−
mice were also more resistant to ischemic stress both
in vivo
and
in vitro
. After 2 h of ischemia and 48 h of reperfusion, cortical infarct volume was reduced by 55%, and the density of terminal deoxynucleotidyltransferase-mediated dUTP nick end labeling-positive cells was decreased by 36% compared with wild type. When subjected to oxygen-glucose deprivation (2 h), cortical neurons cultured from mice deficient in caspase-3 expression were also more resistant to cell death by 59%. Mutant brains showed caspase-specific poly(ADP-ribose) polymerase cleavage product (85-kDa fragment)
in vivo
and
in vitro
, suggesting redundant mechanisms and persistence of caspase-mediated cell death. In the present study, we found that caspase-8 mediated poly(ADP-ribose) polymerase cleavage in caspase-3
−/−
neurons
in vivo
and
in vitro
. In addition, mutant neurons showed no evidence of compensatory activation by caspase-6 or caspase-7 after ischemia. Taken together, these data extend the pharmacological evidence supporting an important role for caspase-3 and caspase-8 as cell death mediators in mammalian cortex and indicate the potential advantages of targeting more than a single caspase family member to treat ischemic cell injury.
Herpes viruses hedge their bets
Authors: Stumpf Michael P. H. , Laidlaw Zoë , Jansen Vincent A. A.
Published: November 2002

Static latency is the hallmark of all herpes viruses. The varicella zoster virus, for instance, causes varicella (chickenpox), and after a latent phase of between 5 and 40 years, it can give rise to herpes zoster (shingles). This latency and the subsequent reactivation has intrigued and puzzled virologists. Although several factors have been suggested, it is unknown what triggers reactivation. However, latency can be explained with a simple evolutionary model. Here, we demonstrate that a simple, yet efficient, bet-hedging strategy might have evolved in a number of viruses, especially those belonging to the herpes virus family and most importantly in varicella zoster virus. We show that the evolution of latency can be explained by the population dynamics of infectious diseases in fluctuating host populations.
A ligand for the aryl hydrocarbon receptor isolated from lung
Authors: Song Jiasheng , Clagett-Dame Margaret , Peterson Richard E. , Hahn Mark E. , Westler William M. , Sicinski Rafal R. , DeLuca Hector F.
Published: November 2002

The aryl hydrocarbon receptor (AHR) is a ligand-inducible transcription factor that is best known because it mediates the actions of polycyclic and halogenated aromatic hydrocarbon environmental toxicants such as 3-methylcholanthrene and 2,3,7,8-tetrachlorodibenzo-
p
-dioxin. We report here the successful identification of an endogenous ligand for this receptor; ≈20 μg was isolated in pure form from 35 kg of porcine lung. Its structure was deduced as 2-(1′H-indole-3′-carbonyl)-thiazole-4-carboxylic acid methyl ester from extensive physical measurements and quantum mechanical calculations. In a reporter gene assay, this ligand activates the AHR with a potency five times greater than that of β-naphthoflavone, a prototypical synthetic AHR ligand. 2-(1′H-indole-3′-carbonyl)-thiazole-4-carboxylic acid methyl ester competes with 2,3,7,8-[
3
H]tetrachlorodibenzo-
p
-dioxin for binding to human, murine, and fish AHRs, thus showing that AHR activation is caused by direct receptor binding, and that recognition of this endogenous ligand is conserved from early vertebrates (fish) to humans.
Nrdp1/FLRF is a ubiquitin ligase promoting ubiquitination and degradation of the epidermal growth factor receptor family member, ErbB3
Authors: Qiu Xiao-Bo , Goldberg Alfred L.
Published: November 2002

The epidermal growth factor receptor (EGFR/ErbB) family of receptor tyrosine kinases plays fundamental roles in the regulation of cell survival, proliferation, and differentiation. Here, we present evidence that ErbB3 is degraded by proteasomes, and that Nrdp1 (referred to as FLRF in mice) associates with ErbB3 and stimulates its ubiquitination and degradation by proteasomes. Nrdp1 mRNAs are expressed in a variety of human tissues. The N-terminal half of Nrdp1 possesses an atypical RING finger domain, which is required for enhancing ErbB3 degradation. Its C-terminal half by itself associates with ErbB3 and raises ErbB3 levels in cells, probably by acting as a dominant–negative form of Nrdp1. In cell-free systems, Nrdp1 has ubiquitin ligase (E3) activity and ubiquitinates ErbB3, as well as itself, in the presence of the ubiquitin-carrier protein (E2), UbcH5. These data indicate that Nrdp1 is a RING finger-type of ubiquitin ligase, which promotes degradation of ErbB3 by proteasomes and, thus, may be an important factor influencing cell growth.
PENROSE LIMIT OF AdS4 × V5,2 AND OPERATORS WITH LARGE R CHARGE
Authors: AHN CHANGHYUN
Published: November 2002

We consider M-theory on AdS4 × V5,2 where V5,2 = SO (5)/ SO (3) is a Stiefel manifold. We construct a Penrose limit of AdS4 × V5,2 that provides the pp-wave geometry. There exists a subsector of three-dimensional [Formula: see text] dual gauge theory, by taking both the conformal dimension and R charge large with the finiteness of their difference, which has enhanced [Formula: see text] maximal supersymmetry. We identify operators in the [Formula: see text] gauge theory with supergravity KK excitations in the pp-wave geometry and describe how the gauge theory operators made out of chiral field of conformal dimension 1/3 fall into [Formula: see text] supermultiplets.
FREE ELECTROMAGNETIC FIELD IN RIEMANNIAN SPACE-TIME via DKP THEORY
Authors: CASANA R. , PIMENTEL B. M. , LUNARDI J. T. , TEIXEIRA R. G.
Published: November 2002

We study the massless Duffin-Kemmer-Petiau (DKP) equation in Riemannian space-times, particularly the massless spin 1 sector which reproduces the free Maxwell's equations.
THE EMBEDDING OF THE SPACETIME IN FIVE DIMENSIONS
Authors: ROMERO C.
Published: November 2002

We briefly review the problem of embedding the spacetime in five dimensions and discuss the geometrical structure of a non-compactified version of Kaluza-Klein theory, known as induced-matter theory. We also highlight the importance of the embedding theorems of differential geometry in the context of embedding theories and present new results which may be considered as extensions of the Campbell-Magaard theorem.
DNA Topology-Mediated Control of Global Gene Expression in Escherichia coli
Authors: Hatfield G. Wesley , Benham Craig J.
Published: November 2002

▪ Abstract  Because the level of DNA superhelicity varies with the cellular energy charge, it can change rapidly in response to a wide variety of altered nutritional and environmental conditions. This is a global alteration, affecting the entire chromosome and the expression levels of all operons whose promoters are sensitive to superhelicity. In this way, the global pattern of gene expression may be dynamically tuned to changing needs of the cell under a wide variety of circumstances. In this article, we propose a model in which chromosomal superhelicity serves as a global regulator of gene expression in Escherichia coli, tuning expression patterns across multiple operons, regulons, and stimulons to suit the growth state of the cell. This model is illustrated by the DNA supercoiling-dependent mechanisms that coordinate basal expression levels of operons of the ilv regulon both with one another and with cellular growth conditions.
Genetics of Influenza Viruses
Authors: Steinhauer David A. , Skehel John J.
Published: November 2002

▪ Abstract  Influenza A viruses contain genomes composed of eight separate segments of negative-sense RNA. Circulating human strains are notorious for their tendency to accumulate mutations from one year to the next and cause recurrent epidemics. However, the segmented nature of the genome also allows for the exchange of entire genes between different viral strains. The ability to manipulate influenza gene segments in various combinations in the laboratory has contributed to its being one of the best characterized viruses, and studies on influenza have provided key contributions toward the understanding of various aspects of virology in general. However, the genetic plasticity of influenza viruses also has serious potential implications regarding vaccine design, pathogenicity, and the capacity for novel viruses to emerge from natural reservoirs and cause global pandemics.
Non–High-Density Lipoprotein Cholesterol Levels Predict Five-Year Outcome in the Bypass Angioplasty Revascularization Investigation (BARI)
Authors: Bittner Vera , Hardison Regina , Kelsey Sheryl F. , Weiner Bonnie H. , Jacobs Alice K. , Sopko George
Published: November 2002

Background—

Current National Cholesterol Education Program guidelines recommend that non–high-density lipoprotein cholesterol (non-HDL-C) be considered a secondary target of therapy among individuals with triglycerides >2.26 mmol/L. It is not known whether non-HDL-C relates to prognosis among patients with coronary heart disease.

Methods and Results—

Lipid levels were available at baseline among 1514 patients (73% men; mean age, 61 years) enrolled in the Bypass Angioplasty Revascularization Investigation (BARI); all had multivessel coronary artery disease. Patients were followed for 5 years. Outcomes of death, nonfatal myocardial infarction, and death or myocardial infarction were modeled using univariate and multivariate time-dependent proportional hazards methods; angina pectoris at 5 years was modeled using univariate and multivariate logistic regression. Non-HDL-C was a strong and independent predictor of nonfatal myocardial infarction (multivariate relative risk, 1.049 [95% confidence intervals, 1.006 to 1.093] for every 0.26 mmol/L increase) and angina pectoris (multivariate odds ratio, 1.049 [95% confidence intervals, 1.004 to 1.096] for every 0.26 mmol/L increase), but it did not relate to mortality. HDL-C and LDL-C did not predict events during follow-up.

Conclusions—

Among patients with lipid values in BARI, non-HDL-C is a strong and independent predictor of nonfatal myocardial infarction and angina pectoris at 5 years, even after consideration of powerful clinical variables. Our data suggest that non-HDL-C is an appropriate treatment target among patients with coronary heart disease.
Desarrollo y validación de la escala de valores hacia el trabajo EVAT 30
Authors: Arciniega Luis , González Luis
Published: November 2002

Este artículo presenta el desarrollo y validación inicial de un instrumento para medir valores hacia el trabajo cuya estructura se fundamenta en la teoría universal del contenido de valores de Schwartz (1992). Los items que integran el cuestionario describen situaciones que reflejan valores hacia el trabajo. Cada una de las diez tipologías que señala la teoría está operacionalizadapor 3 items, a partir de éstos, se intentó identificar a aquellos que representaran en forma consistente los 4 valores de orden superior. Para validar la estructura se empleó una muestra de 246 trabajadores, 169 mexicanos y 77 españoles. En la primera fase y a través de escalamientos multidimensionales (MDS) se identificaron aquellos items con significación equivalente en ambas muestras. Posteriormente se analizó cuáles de éstos se ajustaban mejor a la estructura hipotetizada utilizando para ello la técnica del Análisis Factorial Confirmatorio (CFA). La estructura dinámica de cuatro factores, operacionalizadapor medio de 4 items en cada factor, presentó índices de bondad de ajuste satisfactorios y una consistencia interna acceptable para cada una de las escalas.
La representación social de los derechos humanos en estudiantes universitarios argentinos
Authors: Roselli Néstor D. , Calvo Rafael A. , Spini Dario
Published: November 2002

Esta investigación forma parte de un vasto estudio trans-nacional sobre el tema, llevado a cabo por Doise y colaboradores (1994, 1995, 1999) en la Universidad de Ginebra. Si bien los datos presentes (N:375) fueron recogidos con fines de una comparación internacional, ello no impide un análisis autónomo, por demás significativo.

El cuestionario aplicado en esta ocasión es el mismo que se utilizó en los demás países involucrados en el referido estudio. También el análisis de los datos sigue de cerca el modelo desarrollado por los autores nombrados. De todos modos el análisis prescinde de referencias comparativas ajenas a la población relevada: estudiantes universitarios argentines.
Predictores del prejuicio manifiesto y sutil hacia los gitanos
Authors: Gómez-Berrocal Carmen , Navas Marisol
Published: November 2002

El objetivo principal de esta investigación es explorar las peculiaridades que subyacen a las expresiones prejuiciosas y discriminatorias que la población no gitana manifiesta hacia la gitana. 290 estudiantes de secundaria respondieron a un cuestionario que cubre diversas variables presentes en la literatura psicosocial sobre prejuicio y racismo. Los resultados confirman la mayoría de las relaciones establecidas entre el prejuicio (manifiesto y sutil) hacia los gitanos y variables como la semejanza percibida con el exogrupo, la actitud hacia el multiculturalismo y la asimilación, la identificación con el endogrupo, la naturaleza del contacto con el exogrupo, las emociones que experimentan los sujetos y la percepción de interdependencia con el endogrupo. Asimismo, los análisis de regresión muestran que la variable más predictiva de la actitud prejuiciosa hacia los gitanos es la percepción de semejanza entre endogrupo y exogrupo, seguida por los sentimientos suscitados por los gitanos.
La construcción de la sexualidad en la adolescencia
Authors: Barberá Ester , Navarro Esperanza
Published: November 2002

Se presenta un estudio en el que se analizan las representaciones que elaboran de la sexualidad chicas y chicos a la edad de la pubertad. Se analiza también cómo evolucionan esas representaciones a lo largo de un periodo de seis años. El estudio se ha realizado a partir del análisis del contenido de 1.204 preguntas sobre sexualidad formuladas por chicos y chicas de 13 y 14 años en diversos talleres de educación sexual. El principal resultado es el escaso interés de las chicas por aspectos eróticos de la sexualidad, frente a un gran interés por su cuerpo, la salud reproductiva y el control del embarazo. Se propone la noción del erotismo subrogado para explicar las múltiples diferencias entre chicas y chicos que se observan en los temas por los que preguntan.
¿De tal palo tal astilla? Violencia marital y reponsabilidad de los progenitors
Authors: Yanes José Manuel , González Rosaura
Published: November 2002

Se analiza el peso relativo del nivel de violencia marital observada, y de la responsabilidad atribuida a los progenitors por sus conflictos, en la predicción de la violencia de pareja. De esta forma, se estudia el papel de la interpretación de la experiencia violenta en el proceso de transmisión. La investigación se llevó a cabo con sesenta parejas de universitarios. Los resultados confirman la importancia de la responsabilidad que se atribuye a los progenitores en la predicción de la transmisión de la violencia de pareja. Asimismo, sugieren que una interpretación de la violencia interparental más favorable al progenitor del mismo sexo sitúa a los hijos en una situación de mayor riesgo.
¿Por qué cumplimos las normas? Un análisis psicosocial del concepto de legitimidad
Authors: Oceja Luis V. , Fernández-Dols José Miguel , González Angélica , Jiménez Isabel , Berenguer Jaime
Published: November 2002

Hemos estudiado como cuatro variables (“probabilidad percibida de castigo formal”, “desaprobación social”, “legitimidad” y “convencionalismo”) determinan el cumplimiento o la transgresión de las normas. Se analizó la percepción de cumplimiento de seis normas específicas en 298 hombres y mujeres de tres países (España, Estados Unidos y Chile). Se comprobó la capacidad predictiva de un modelo que incluye las tres primeras variables citadas, frente a otro modelo en el que se incluye el “convencionalismo” como cuarta variable. Los resultados muestran que (a) la legitimidad—entendida como grado de acuerdo entre una norma específica y los principios morales del individuo—es la única variable con capacidad predictiva, y (b) el convencionalismo—entendido como una orientación legalista y conformista hacia el mantenimiento del orden—modera la capacidad predictiva de la legitimidad.
Evaluación del sexismo moderno en adolescentes
Authors: Lameiras Maria , Rodríguez Yolanda
Published: November 2002

El objetivo de esta investigación es identificar el nivel de sexismo interiorizado tanto hacia mujeres como hacia hombres por adolescentes. Para la consecución de este objetivo se aplica a una muestra de 406 estudiantes de Educación Secundaria Obligatoria (205 chicos y 201 chicas), con un rango de edad 13 a 16 años, las siguientes escalas: ASI, Ambivalent Sexism Inventory (Glick y Fiske, 1996), versión española de Expósito, Moya y Glick (1998), AMI, Ambivalent towards Men Inventory (Glick y Fiske, 1999), versión española de Lameiras, Rodríguez y Sotelo (2001); EIRS, Escala de Ideología del Rol Sexual (Moya, Navas y Gómez-Berrocal, 1991). Los resultados muestran que los chicos son más sexistas hacia las mujeres y tienen mayores actitudes benevolentes hacia los hombres, tendencia que se mantiene en las diferentes edades evaluadas aunque con una ligera disminución de las actitudes sexistas más benevolentes. Por su parte el EIRS predice tanto el sexismo hostil como el sexismo benevolente aunque éste en mayor medida, por lo que puede ser utilizado al igual que las escalas ASI y AMI eficazmente para medir el sexismo moderno, resultado de la combinación del hostil y el benevolente.
Aceptación de sistemas operativos de producción cuando la conducta de uso es obligatoria
Authors: Pinazo Daniel , Agut Sonia , Gimeno Miguel Ángel
Published: November 2002

Los modelos que explican la aceptación de los sistemas asistidos por ordenador, se basan en la conducta voluntaria del objeto de actitud. El presente trabajo compara la intención de uso de sistemas asistidos por ordenador en trabajadores de producción en los que la conducta de uso es obligatoria. En este contexto es importante la aceptación de la tecnología por sus implicaciones sobre la motivación. Comparamos un grupo de trabajadores con experiencia de uso obligatorio (N=191) con otro sin experiencia de uso (N=136), en relación a su evaluación de los sistemas asistidos por ordenador y la intención de uso. Los resultados confirman que la experiencia es un mejor indicador de la aceptación de las tecnologías, así como confirman la existencia de múltiples dimensiones de la evaluación de los sistemas asistidospor ordenador, con consecuencias diferentes para su aceptación.
Estructura social y personalidad en la obra de Ignacio Martín Baró
Authors: Sánchez Esteban , Trejo Zarahy
Published: November 2002

Este artículo tiene como objetivo analizar la obra de Ignacio Martín Baró utilizando un marco teórico fundamental en la historia de la Psicología Social: el estudio de la Estructura Social y la Personalidad. Según J. S. House (1977), esta perspectiva tiene sus raíces en algunos de los grandes pensadores que inauguran la Sociología: Marx, Weber y Durkheim. Su principal característica sería la integración tanto en el nivel teórico como en el nivel empírico de elementos de estructura social y elementos psicológicos o de personalidad. La perspectiva psicosocial se caracterizaría por esta integración teórica y empírica.

El análisis de la conducta humana y de la realidad social presente en la obra de Martín Baró comparte en gran medida estos principios. En el presente artículo se analizan el tratamiento que el autor da a aspectos como la violencia, la pobreza, las actitudes y a la propia definición de la Psicología Social. Finalmente, se señalan las notas características de la perspectiva de Martín Baró en relación con el estudio de la estructura social y la personalidad.
Solid‐state 13C‐NMR investigations of crosslinked structure modifications in elastomers during heating treatment
Authors: Buzaré Jean‐Yves , Silly G. , Emery J. , Boccaccio Guy , Rouault Eric
Published: November 2002

The chemical modifications occurring during the thermal degradation of sulfur‐cured natural rubber were investigated with 13C‐NMR. Samples of vulcanized rubbers were heat‐aged at 70°C under an air (oxidative) environment for 3, 7, and 21 days. Changes were analyzed by the measurement of the variations of the concentrations of different C–Sx–C crosslinked structures during the thermooxidative process through the intensity of the related NMR lines in the 10–70‐ppm range. © 2002 Wiley Periodicals, Inc. J Appl Polm Sci 87:3–8, 2003
Interleukin‐15 inhibits sodium nitroprusside–induced apoptosis of synovial fibroblasts and vascular endothelial cells
Authors: Yang Lin , Thornton Sherry , Grom Alexei A.
Published: November 2002

Objective

One of the pathologic hallmarks of juvenile rheumatoid arthritis (JRA) is a tumor‐like expansion of inflamed synovial tissue, or pannus, which causes much of the joint damage in this disease. The expansion of pannus is supported by extensive formation of new blood vessels. We have previously shown that revascularization of minced JRA synovial tissues engrafted into SCID mice correlated with the intensity of inflammatory activity in the tissues and with interleukin‐15 (IL‐15) expression. Since synovial vascular endothelial cells (VECs) expressed IL‐15 receptors, the present study was undertaken to investigate the hypothesis that IL‐15 might play a role in neovascularization of the pannus.

Methods

To evaluate IL‐15 for possible angiogenic activity, we assessed the ability of recombinant human IL‐15 (rHuIL‐15) to induce VEC growth directly and to stimulate synovial cells to produce endothelial growth factors. Since IL‐15 had been shown to inhibit apoptosis of certain immune cells, we were also interested in whether it might have similar effects on VECs. Apoptosis was induced by addition of sodium nitroprusside (SNP) at 1–2 mM to >80% confluent primary VECs, and numbers of apoptotic cells were determined by annexin V assay.

Results

Addition of rHuIL‐15 at 10–100 ng/ml to primary synovial fibroblast cultures failed to up‐regulate expression of vascular endothelial growth factor and angiopoietin 1 by these cells. Although rHuIL‐15 failed to induce a mitogenic response of VECs, it promoted survival of these cells on Matrigel. Preincubation of VECs with rHuIL‐15 at 50 ng/ml significantly reduced the proportion of VECs undergoing apoptosis.

Conclusion

IL‐15 promotes survival of VECs on Matrigel and inhibits SNP‐induced apoptosis of endothelial cells. We hypothesize that this mechanism may be relevant to the stabilization of newly formed vascular structures in JRA synovium.
Fast spin echo–T2‐weighted sequences with fat saturation in dactylitis of spondylarthritis
Authors: Olivieri Ignazio , Salvarani Carlo , Cantini Fabrizio , Scarano Enrico , Padula Angela , Niccoli Laura , Ciancio Giovanni , Barozzi Libero
Published: November 2002

Objective

To establish by means of fast spin echo (FSE)–T2‐weighted sequences with fat saturation if enthesitis of the flexor digitorum superficialis and profundus tendons is the primary lesion in spondylarthritis (SpA) finger dactylitis.

Methods

Eleven dactylitic fingers and their corresponding normal, contralateral fingers, belonging to 6 patients who met the Amor criteria for SpA, were studied by FSE–T2‐weighted sequences with fat saturation.

Results

All dactylitic fingers showed moderate or severe fluid collection in the flexor tendon synovial sheaths. Involvement of the joint cavity was simultaneously present in at least one joint in 3 (27.3%) of the 11 fingers. A mild to moderate peritendinous soft tissue edema was observed in 5 (45.5%) of the 11 affected fingers. In no dactylitic finger was bone edema observed near the insertions of the flexor digitorum superficialis or profundus tendons or in other sites of the phalanges. No lesions were observed in the 11 contralateral, clinically normal fingers.

Conclusion

In SpA dactylitis there is no evidence of enthesitis of the flexor digitorum tendons and joint capsules.
A shared mission? Changing relationships between government and church health services in Africa
Authors: Green A. , Shaw J. , Dimmock F. , Conn Cath
Published: November 2002

This article reviews the relationships between government and church health providers within sub‐Saharan Africa with a particular focus on East and Southern Africa. This is of particular interest at this time, given the changing configuration of the health sector in many countries as a result of health sector reform policies. The article provides a historical overview of the development and emerging role of the church health services within this changing environment.

The factors affecting the relationship between the government and church sector are identified. These include differences in objectives, types of service provided, and the organizational culture and management styles. The paper then explores key issues seen to affect the future pattern of relationships including the changing scene, and identifies different models for relationships and implications for key actors including the Ministry of Health, church health agencies and coordinating bodies. The article concludes that church health services will continue to play a key role in health care in sub‐Saharan Africa; however, there are challenges facing them and both parties need to develop a response to these. Copyright © 2002 John Wiley & Sons, Ltd.
Radiofrequency‐induced temperature increase as a function of cross polarization contact time in 8CB
Authors: Chattah Ana K. , Cucchietti Fernando M. , Hologne Maggy , Raya Jésus , Levstein Patricia R.
Published: November 2002

In this work we analyse the non‐negligible heating effect that can be produced by the radiofrequency during the contact time in Hartmann–Hahn cross polarization experiments in liquid crystals. We perform the analysis in the nematic phase of 4‐n‐octyl‐4′‐cyanobiphenyl (8CB). The heating effect is quantified through the chemical shifts of the carbon resonances, which move towards their respective positions in the isotropic phase when increasing the contact time. The calibration procedure involves an independent measurement of chemical shift dependence on externally controlled bath temperature. This variation was performed in the range between 300 and 313 K covering the smectic A and nematic mesophases. An overall heating rate of 0.16 K ms−1 is observed during the contact time in a cross polarization experiment performed at ω1/2π ≃ 80 kHz. This rate goes to approximately one‐half for ω1/2π ≃ 60 kHz and becomes unobservable for ω1/2π < 50 kHz under typical experimental conditions. Copyright © 2002 John Wiley & Sons, Ltd.
Engineered design of masonry buildings: fifty years development in Europe
Authors: Hendry A W
Published: November 2002

This paper describes the development of the structural design of multi‐storey, load‐bearing masonry buildings in the United Kingdom and the European Community over the second half of the 20th century. Tall buildings of this type had fallen into disuse in the first half of the century as the empirical rules governing their design led to walls of excessive thickness. The application of engineering principles to load‐bearing masonry was pioneered in Switzerland, and in the United Kingdom a rudimentary code of practice appeared in 1949. This was used for the design of buildings in the following decade, but its limitations led to research work on a number of key problems, and eventually to the publication of a completely new code, based on limit state principles, in 1978. Parallel work by international organizations and later in the European Union led to the publication of a draft code, intended for use in countries of the EU in 1995. Essential problems of overall stability and safety and the design of walls in compression and under combined compressive and lateral loads have been addressed. The paper summarizes the approach to these problems which has been adopted in the UK and EU codes with reference to relevant research work, in particular to projects with which the author has been associated.
New technologies for engineered timber structures
Authors: Natterer Julius K
Published: November 2002

Nearly every shape of construction can be built in an economical way from timber if the development of the structure is studied carefully. All new construction is a challenge, and the engineer, in collaboration with the architect, must abandon routine to explore the range of techniques for timber construction. Supported by the latest research, the engineer can find the optimal solution, and adapt to the requirements of modern architecture.
‘Come on, Girls, Let's Go Bail Water’: Eroticism in Hô Xuân Hu'o'ng's Vietnamese Poetry
Authors: My˜-Vân Trân
Published: November 2002

This study offers insights into the popular nôm poetry written by Hô Xuân Hu'o'ng, who brought to life the battles of the sexes, the power of the female body versus male authority, human weakness and desire and a range of issues and experiences potentially detrimental to women's status and aspirations. This study also examines the treatment of Hô Xuân Hu'o'ng's poetry by present-day Vietnamese.
Bovine oocytes in early antral follicles grow in serum-free media: effect of hypoxanthine on follicular morphology and oocyte growth
Authors: Senbon Shoichiro , Miyano Takashi
Published: November 2002

Some culture systems have been shown to support oocyte growth in mice, although there has been little success in applying these systems to other species. In the present study, we compared three culture conditions for growing bovine oocytes and examined the effect of hypoxanthine on oocyte growth. In the first experiment, early antral follicles, 0.4-0.7 mm in diameter were collected, and oocyte-cumulus-granulosa cell complexes (OCGs) and oocyte-cumulus cell complexes (OCs) were dissected from the follicles. Follicles (Fs), OCGs and OCs were embedded in collagen gels and cultured in serum-supplemented medium for 16 days. In the Fs, OCGs and OCs cultured in hypoxanthine-free medium, 21%, 9% and 4% of the oocytes showed normal morphology, respectively, and hypoxanthine (4 mM) increased the percentages in all the groups (Fs, 37%; OCGs, 29%; OCs, 10%). In the second experiment, Fs were cultured in serum-free medium with or without hypoxanthine for 16 days. Histological examination demonstrated that hypoxanthine maintained the integrity of the follicular basement membrane. After a growth culture, 91% of the oocytes showed normal morphology, and 87% of the oocytes were at the germinal vesicle stage in serum-free, hypoxanthine-supplemented medium. The mean diameters of the oocytes were significantly larger (117.6 ± 5.7 mm) than they were in the other groups and than they had been before the culture (approximately 95 mm). After a subsequent maturation culture of the oocytes, 85% underwent germinal vesicle breakdown and 23% reached the second metaphase. These results demonstrate that growing bovine oocytes from early antral follicles grow efficiently in follicles cultured in serum-free, hypoxanthine-supplemented medium and acquire meiotic competence.
Research responsibilities
Authors: THE EDITORS
Published: November 2002

The debate on the UK Government's recent Research Assessment Exercise (RAE), which
has grown steadily over our past two issues (5/4 and 6/1), reaches a climax in this one.
Perhaps the time has come to ask whether arq is becoming parochial in its focus on a
matter that seems of concern only to the UK. However, we offer no apologies for using
the RAE debate to highlight the research crisis in architecture – a crisis that is by no
means confined to the UK.

There are many issues under discussion. There is the simple matter of the
‘accuracy’ of the system in recognising high quality work: our correspondents
(pp. 101–103) seem divided on this. Then there is the question of ‘fairness’ in the size
of the financial reward: the sums available for distribution meant that many who
performed well were awarded less than in the last round. And there is the ever
recurring question of design as ‘research’: Bryan Lawson's contribution (pp. 109–114)
surely provides the last word on this.

Three correspondents widen the debate beyond the RAE. Colin Stansfield Smith
(p. 104) writes of a procurement system in which architecture has become
marginalised. John Worthington (p. 104) makes a plea for both the profession and
the schools to look outwards. And, almost incredibly, the letter from the outgoing
RIBA Vice President for Education, Alan Jones (p. 105), seems to suggest that arq's
prodding may have provoked coordinated action within the Institute.

The latest news is that the two incoming Vice Presidents for Education and
Practice, Jack Pringle and Richard Saxon, are practitioners who are determined to
bridge the gap between the profession and academia. Each is committed to
promoting, supporting and disseminating research. Both see it not as a problem to
be ignored but as an opportunity to be grasped. We wish them every success.

There is much to be done. Real needs must be identified and matched to available
means in academia and practice; valuable unpublished material uncovered;
appropriate methods of dissemination developed; and a realistic implementation
strategy evolved. If the RIBA could, in partnership with practice and academia,
develop such a programme, it would, in the process, acquire the ability to support
the architecture schools in the pursuit of their own (and the profession's) interests.
It would also enable the profession to speak with the kind of authority that the RICS
Foundation has given the surveyors.

It is this wider agenda with which arq is concerned. If leading-edge practitioners
and academics have a duty to enhance the profession's knowledge base then
professional institutes have a responsibility as its guardians and sponsors. All must
work together in a world in which architecture is increasingly under threat.
An assay to evaluate the long‐term effects of inflammatory mediators on murine airway smooth muscle: evidence that TNFα up‐regulates 5‐HT2A‐mediated contraction
Authors: Adner Mikael , Rose Andrew C , Zhang Yaping , Swärd Karl , Benson Mikael , Uddman Rolf , Shankley Nigel P , Cardell Lars‐Olaf
Published: November 2002

Asthma research is arguably limited by an absence of appropriate animal models to study the pharmacology of inflammatory mediators that affect airway hyperresponsiveness and remodelling. Here we assessed an assay based on mouse tracheal segments cultured for 1–32 days, and investigated contractile responses mediated by muscarinic and 5‐hydroxytryptamine (5‐HT) receptors following long‐term exposure to tumour necrosis factor‐alpha (TNFα).

Following culture, in the absence of TNFα, maximum contractile responses to KCl and carbachol were similar, with an increase in response up to day two and a decrease to a stable level after 8 days. Maximal relaxations to isoprenaline were not affected by the culture procedure. The potency of KCl and isoprenaline increased throughout the study. DNA microarray data revealed that global gene expression changes were greater when tissues were introduced to culture than when they were maintained in culture. The morphology of smooth muscle cells was maintained throughout the culture period.

5‐HT induced a weak contraction in both fresh and cultured (up to 8 days) segments. Culture with TNFα produced a time‐ and concentration‐dependent increase in the maximal contraction to 5‐HT, evidently mediated by 5‐HT2A receptors, whereas, the potency for carbachol was reduced.

In conclusion, the phenotype of airway smooth muscle remained largely intact during the culture period, even though minor changes were obtained during the first days of culture. The time‐dependent effect of TNFα indicates the importance of studying the long‐term effect of cytokines on the smooth muscle cells in relation to airway hyperresponsiveness and remodelling.

British Journal of Pharmacology (2002) 137, 971–982. doi:10.1038/sj.bjp.0704928