Showing papers by "University of Barcelona published in 2002"

The Use of Molecular Profiling to Predict Survival after Chemotherapy for Diffuse Large-B-Cell Lymphoma

Abstract: Background The survival of patients with diffuse large-B-cell lymphoma after chemotherapy is influenced by molecular features of the tumors. We used the gene-expression profiles of these lymphomas to develop a molecular predictor of survival. Methods Biopsy samples of diffuse large-B-cell lymphoma from 240 patients were examined for gene expression with the use of DNA microarrays and analyzed for genomic abnormalities. Subgroups with distinctive gene-expression profiles were defined on the basis of hierarchical clustering. A molecular predictor of risk was constructed with the use of genes with expression patterns that were associated with survival in a preliminary group of 160 patients and was then tested in a validation group of 80 patients. The accuracy of this predictor was compared with that of the international prognostic index. Results Three gene-expression subgroups — germinal-center B-cell–like, activated B-cell–like, and type 3 diffuse large-B-cell lymphoma — were identified. Two common oncogeni...

Statistical properties of new neutrality tests against population growth.

Abstract: A number of statistical tests for detecting population growth are described. We compared the statistical power of these tests with that of others available in the literature. The tests evaluated fall into three categories: those tests based on the distribution of the mutation frequencies, on the haplotype distribution, and on the mismatch distribution. We found that, for an extensive variety of cases, the most powerful tests for detecting population growth are Fu's F(S) test and the newly developed R(2) test. The behavior of the R(2) test is superior for small sample sizes, whereas F(S) is better for large sample sizes. We also show that some popular statistics based on the mismatch distribution are very conservative.

Finite-size effects in fine particles: magnetic and transport properties

Abstract: Some of the most relevant finite-size and surface effects in the magnetic and transport properties of magnetic fine particles and granular solids are reviewed. The stability of the particle magnetization, superparamagnetic regime and the magnetic relaxation are discussed. New phenomena appearing due to interparticle interactions, such as the collective state and non-equilibrium dynamics, are presented. Surface anisotropy and disorder, spin-wave excitations, as well as the enhancements of the coercive field and particle magnetization are also reviewed. The competition of surface and finite-size effects to settle the magnetic behaviour is addressed. Finally, two of the most relevant phenomena in the transport properties of granular solids are summarized namely, giant magnetoresistance in granular heterogeneous alloys and Coulomb gap in insulating granular solids.

Notas sobre a experiência e o saber deexperiência

Abstract: Propoe pensar-se a educacao a partir do par experiencia/sentido, contrapondo-se ao modo de pensar a educacao como relacao entre ciencia e tecnica, ou entre teoria e pratica. Para tanto, explora o significado das palavras experiencia e sentido. Quanto a primeira, critica o excesso de informacao e a obrigatoriedade de ter opiniao, posturas que estao na base da "aprendizagem significativa". Critica tambem o excesso de trabalho, que nao permite a experiencia, e a propria relacao trabalho/experiencia. Quanto ao sentido, explora-o a partir do sujeito da experiencia, definido nao por sua atividade, mas pela abertura para ser transformado pela experiencia - territorio de passagem, submetido a uma logica da paixao. Afirma que o saber da experiencia se da na relacao entre o conhecimento e a vida humana, singular e concreta.

Immunosuppressive therapy in lupus nephritis: the Euro-Lupus Nephritis Trial, a randomized trial of low-dose versus high-dose intravenous cyclophosphamide.

Abstract: OBJECTIVE: Glomerulonephritis is a severe manifestation of systemic lupus erythematosus (SLE) that is usually treated with an extended course of intravenous (IV) cyclophosphamide (CYC). Given the side effects of this regimen, we evaluated the efficacy and the toxicity of a course of low-dose IV CYC prescribed as a remission-inducing treatment, followed by azathioprine (AZA) as a remission-maintaining treatment. METHODS: In this multicenter, prospective clinical trial (the Euro-Lupus Nephritis Trial [ELNT]), we randomly assigned 90 SLE patients with proliferative glomerulonephritis to a high-dose IV CYC regimen (6 monthly pulses and 2 quarterly pulses; doses increased according to the white blood cell count nadir) or a low-dose IV CYC regimen (6 fortnightly pulses at a fixed dose of 500 mg), each of which was followed by AZA. Intent-to-treat analyses were performed. RESULTS: Followup continued for a median of 41.3 months in the low-dose group and 41 months in the high-dose group. Sixteen percent of those in the low-dose group and 20% of those in the high-dose group experienced treatment failure (not statistically significant by Kaplan-Meier analysis). Levels of serum creatinine, albumin, C3, 24-hour urinary protein, and the disease activity scores significantly improved in both groups during the first year of followup. Renal remission was achieved in 71% of the low-dose group and 54% of the high-dose group (not statistically significant). Renal flares were noted in 27% of the low-dose group and 29% of the high-dose group. Although episodes of severe infection were more than twice as frequent in the high-dose group, the difference was not statistically significant. CONCLUSION: The data from the ELNT indicate that in European SLE patients with proliferative lupus nephritis, a remission-inducing regimen of low-dose IV CYC (cumulative dose 3 gm) followed by AZA achieves clinical results comparable to those obtained with a high-dose regimen.

Elucidation of the methylerythritol phosphate pathway for isoprenoid biosynthesis in bacteria and plastids. A metabolic milestone achieved through genomics.

Abstract: Plants synthesize an enormous variety of metabolites that can be classified into two groups based on their function: primary metabolites, which participate in nutrition and essential metabolic processes within the plant, and secondary metabolites (also referred to as natural products), which

Male circumcision, penile human papillomavirus infection, and cervical cancer in female partners

Abstract: Background It is uncertain whether male circumcision reduces the risks of penile human papillomavirus (HPV) infection in the man and of cervical cancer in his female partner. Methods We pooled data on 1913 couples enrolled in one of seven case–control studies of cervical carcinoma in situ and cervical cancer in five countries. Circumcision status was self-reported, and the accuracy of the data was confirmed by physical examination at three study sites. The presence or absence of penile HPV DNA was assessed by a polymerase-chain-reaction assay in 1520 men and yielded a valid result in the case of 1139 men (74.9 percent). Results Penile HPV was detected in 166 of the 847 uncircumcised men (19.6 percent) and in 16 of the 292 circumcised men (5.5 percent). After adjustment for age at first intercourse, lifetime number of sexual partners, and other potential confounders, circumcised men were less likely than uncircumcised men to have HPV infection (odds ratio, 0.37; 95 percent confidence interval, 0.16 to 0.85...

Mutations in the O-Mannosyltransferase Gene POMT1 Give Rise to the Severe Neuronal Migration Disorder Walker-Warburg Syndrome

Abstract: Walker-Warburg syndrome (WWS) is an autosomal recessive developmental disorder characterized by congenital muscular dystrophy and complex brain and eye abnormalities. A similar combination of symptoms is presented by two other human diseases, muscle-eye-brain disease (MEB) and Fukuyama congenital muscular dystrophy (FCMD). Although the genes underlying FCMD (Fukutin) and MEB (POMGnT1) have been cloned, loci for WWS have remained elusive. The protein products of POMGnT1 and Fukutin have both been implicated in protein glycosylation. To unravel the genetic basis of WWS, we first performed a genomewide linkage analysis in 10 consanguineous families with WWS. The results indicated the existence of at least three WWS loci. Subsequently, we adopted a candidate-gene approach in combination with homozygosity mapping in 15 consanguineous families with WWS. Candidate genes were selected on the basis of the role of the FCMD and MEB genes. Since POMGnT1 encodes an O-mannoside N-acetylglucosaminyltransferase, we analyzed the possible implication of O-mannosyl glycan synthesis in WWS. Analysis of the locus for O-mannosyltransferase 1 (POMT1) revealed homozygosity in 5 of 15 families. Sequencing of the POMT1 gene revealed mutations in 6 of the 30 unrelated patients with WWS. Of the five mutations identified, two are nonsense mutations, two are frameshift mutations, and one is a missense mutation. Immunohistochemical analysis of muscle from patients with POMT1 mutations corroborated the O-mannosylation defect, as judged by the absence of glycosylation of α-dystroglycan. The implication of O-mannosylation in MEB and WWS suggests new lines of study in understanding the molecular basis of neuronal migration.

Calmodulins and Calcineurin B–like Proteins: Calcium Sensors for Specific Signal Response Coupling in Plants

Abstract: ### Calcium Signaling and Calcium Sensors: A General Paradigm Many extracellular signals, including light, biotic, and abiotic stress factors, elicit changes in cellular Ca2+ concentration in plants ([Trewavas and Knight, 1994][1]; [Bush, 1995][2]; [Braam et al., 1997][3]; [McAinsh et al., 1997][4

Long-Term Follow-Up of Individuals With the Electrocardiographic Pattern of Right Bundle-Branch Block and ST-Segment Elevation in Precordial Leads V1 to V3

Abstract: Background— The electrocardiographic pattern of right bundle-branch block with ST-segment elevation in leads V1 to V3 is increasingly recognized among patients who have aborted sudden cardiac death, but also in asymptomatic individuals, raising questions about its prognostic significance. Methods and Results— The clinical, electrophysiological, and follow-up data of 334 patients with the Brugada phenotype were analyzed. A total of 79 women and 255 men with a mean age at diagnosis of 42±16 years were studied. The abnormal ECG was recognized after a resuscitated cardiac arrest in 71 patients (group A), after a syncopal episode in 73 patients (group B), and in 190 asymptomatic individuals (group C). Sustained ventricular arrhythmias were inducible in 83%, 63%, and 33% of patients in group A, group B, and group C, respectively. During 54±54 and 26±36 months of follow-up, respectively, 62% of patients in group A and 19% of group B patients had a new arrhythmic event. Inducibility of ventricular arrhythmias was...

The Function of Tocopherols and Tocotrienols in Plants

Abstract: Referee: Dr. Kozi Asada, Department of Biotechnology, Faculty of Engineering, Fukuyama University, Gakuencho 1, Fukuyama 729-0292, Japan Tocopherols and tocotrienols, which differ only in the degree of saturation of their hydrophobic prenyl side chains, are lipid-soluble molecules that have a number of functions in plants. Synthesized from homogentisic acid and isopentenyl diphosphate in the plastid envelope, tocopherols and tocotrienols are essential to maintain membrane integrity. α-Tocopherol is the major form found in green parts of plants, while tocotrienols are mostly found in seeds. These compounds are antioxidants, thus they protect the plant from oxygen toxicity. Tocopherols and tocotrienols scavenge lipid peroxy radicals, thereby preventing the propagation of lipid peroxidation in membranes, and the ensuing products tocopheroxyl and tocotrienoxyl radicals, respectively, are recycled back to tocopherols and tocotrienols by the concerted action of other antioxidants. Furthermore, tocopherols and t...

Optimal Network Topologies for Local Search with Congestion

Abstract: The problem of searchability in decentralized complex networks is of great importance in computer science, economy, and sociology. We present a formalism that is able to cope simultaneously with the problem of search and the congestion effects that arise when parallel searches are performed, and we obtain expressions for the average search cost both in the presence and the absence of congestion. This formalism is used to obtain optimal network structures for a system using a local search algorithm. It is found that only two classes of networks can be optimal: starlike configurations, when the number of parallel searches is small, and homogeneous-isotropic configurations, when it is large.

Epidemic spreading in correlated complex networks.

Abstract: We study a dynamical model of epidemic spreading on complex networks in which there are explicit correlations among the node's connectivities. For the case of Markovian complex networks, showing only correlations between pairs of nodes, we find an epidemic threshold inversely proportional to the largest eigenvalue of the connectivity matrix that gives the average number of links, which from a node with connectivity k go to nodes with connectivity k('). Numerical simulations on a correlated growing network model provide support for our conclusions.

Spontaneous resolution under supramolecular control

Abstract: The spontaneous resolution of enantiomers is an intriguing and important phenomenon in a number of research areas. Non-covalent interactions can play a key role in the process which can now be observed not only in crystals, but in liquid crystals, self-assembled monolayers, self-assembled fibres, and supramolecules self-assembled in solution. The evidence gathered in all of these areas is important for explaining the transfer of chirality from molecule to bulk, and in particular the spontaneous resolution of enantiomers.

Differential equations driven by fractional Brownian motion

Abstract: A global existence and uniqueness result of the solution for multidimensional, time dependent, stochastic differential equations driven by a fractional Brownian motion with Hurst parameter H > 1/2 is proved. It is shown, also, that the solution has finite moments. The result is based on a deterministic existence and uniqueness theorem whose proof uses a contraction principle and a priori estimates.

Comparison between the Radical Scavenging Activity and Antioxidant Activity of Six Distilled and Nondistilled Mediterranean Herbs and Aromatic Plants

Abstract: Thirty-six different extracts of six herbs and aromatic plants (fennel, common melilot, milfoil, lavandin cv Super, spike lavender, and tarragon) were evaluated for their radical scavenging activity by the DPPH•, NBT/hypoxanthine superoxide, and •OH/luminol chemiluminescence methods, and for their antioxidant activity by the β-carotene blenching test The total phenolic content was also determined by the Folin-Ciocalteu method The plant material included cultivated plants and their wastes after being distilled for essential oils Both remarkably high phenolic content and radical scavenging activities were found for the ethyl acetate and dichloromethane fractions among the different plant extracts In general, the distilled plant material was found to exhibit a higher phenolic content as well as antioxidant and radical scavenging activities than the nondistilled material Ethyl acetate and dichloromethane extracts, and even some crude extract, of both distilled and nondistilled plants exhibited activitie

Gender differences in morningness–eveningness preference

Abstract: Morningness - eveningness preference (morning-, intermediate-, evening- type) or circadian typology is the individual difference that most clearly explains the variations in the rhythmic expression of biological or behavioral patterns. The aim of this study was to analyze gender difference in morningness - eveningness preference using the Horne and Ostberg questionnaire in the largest university student population selected so far ðN ¼ 2135Þ; with an age range 18 -30 yr. Morningness -eveningness questionnaire (MEQ) score distribution closely correlated to the normal curve ðrange ¼ 17 - 78; mean ¼ 48:25; SD ¼ 10:11Þ; with 338 (15.84%) morning-types, 1273 (59.62%) intermediate-types, and 524 (24.54%) evening-types. The men and women differed significantly in their mean scores ðp , 0:0001Þ and distribution per circadian typology ðp , 0:00001Þ; with the men presenting a more pronounced eveningness preference. Three factors were identified by factor analysis: time of greatest efficiency (I), sleep time/sleep phase (II), awakening time/sleep inertia (III). The MEQ items sensitive to gender differences were essentially those included in factor I and factor II. The results are discussed in relation to recent models of circadian regulation of the sleep - wake cycle. (Chronobiology International, 19(4), 709-720, 2002)

Factors that impact on quality of life in Parkinson's disease: results from an international survey

Abstract: Current management guidelines for the treatment of patients with Parkinson's disease (PD) are limited due to the lack of knowledge of factors that influence health‐related quality of life (HRQL). To assess the HRQL of people with PD, and to systematically identify and evaluate those factors (other than disease severity and medication, which could have an impact), we undertook a cross‐sectional, randomized selection, multicenter international survey of patients with PD, caregivers, and clinicians. Face‐to‐face interviews were conducted with subjects in six countries. Disease severity, medication, and other factors hypothesized to influence HRQL were assessed using a combination of specially developed questionnaires and validated instruments including the Parkinson's Disease Questionnaire‐39 (HRQL), Hoehn and Yahr Stage (disease severity), and Beck's Depression Inventory (BDI; depression). Multiple linear regression models were used to demonstrate whether the factors investigated contribute significantly to HRQL. The results obtained indicated that Hoehn and Yahr stage and medication explained only 17.3% of the variability in HRQL of patients with PD, although both were significant (R2 = 0.173, P < 0.05). Other factors increased the explanatory power to adjusted R2 = 0.597, with BDI being the most significant predictor of variability in HRQL (adjusted R2 = 0.582; P < 0.001), followed by “Satisfaction with the explanation of the condition at diagnosis” and “Current feelings of optimism” (both P < 0.05). These factors, in addition to disease severity and medication, explain 59.7% of the variability in HRQL across the population. In conclusion, depression (as measured by the BDI) in PD, “satisfaction with the explanation of the condition at diagnosis” and “current feelings of optimism” have a significant impact on HRQL. The completion of this initial analysis is the first step towards developing management guidelines that truly influence the HRQL of patients with PD. © 2001 Movement Disorder Society.