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J C Oliveros

Publications and source records attributed to J C Oliveros.

12 recordsLinked to original sources
PubMed2001

Mining functional information associated with expression arrays.

Deciphering the networks of interactions between molecules in biological systems has gained momentum with the monitoring of gene expression patterns at the genomic scale. Expression array experiments provide vast amounts of experimental data about these networks, the analysis of which requires new computational methods. In particular, issues related to the extraction of biological information are key for the end users. We propose here a strategy, implemented in a system called GEISHA (gene expression information system for human analysis) and able to detect biological terms significantly associated to different gene expression clusters by mining collections of Medline abstracts. GEISHA is based on a comparison of the frequency of abstracts linked to different gene clusters and containing a given term. Interpretation by the end user of the biological meaning of the terms is facilitated by embedding them in the corresponding significant sentences and abstracts and by establishing relations with other, equally significant terms. The information provided by GEISHA for the available yeast expression data compares favorably with the functional annotations provided by human experts, demonstrating the potential value of GEISHA as an assistant for the analysis of expression array experiments.

Animals↗
PubMed2000

A freezing-sensitive mutant of Arabidopsis, frs1, is a new aba3 allele.

To investigate the molecular mechanisms controlling the process of cold acclimation and to identify genes involved in plant freezing tolerance, mutations that impaired the cold acclimation capability of Arabidopsis thaliana (L.) Heynh were screened for. A new mutation, frs1 (freezing sensitive 1), that reduced both the constitutive freezing tolerance as well as the freezing tolerance of Arabidopsis after cold acclimation was characterized. This mutation also produced a wilty phenotype and excessive water loss. Plants with the frs1 mutation recovered their wild-type phenotype, their capability to tolerate freezing temperatures and their capability to retain water after an exogenous abscisic acid (ABA) treatment. Measurements of ABA revealed that frs1 mutants were ABA deficient, and complementation tests indicated that frs1 mutation was a new allele of the ABA3 locus showing that a mutation in this locus leads to an impairment of freezing tolerance. These results constitute the first report showing that a mutation in ABA3 leads to an impairment of freezing tolerance, and not only strengthen the conclusion that ABA is required for full development of freezing tolerance in cold-acclimated plants, but also demonstrate that ABA mediates the constitutive freezing tolerance of Arabidopsis. Gene expression in frs1 mutants was altered in response to dehydration, suggesting that freezing tolerance in Arabidopsis depends on ABA-regulated proteins that allow plants to survive the challenges imposed by subzero temperatures, mainly freeze-induced cellular dehydration.

Acclimatization↗
PubMed2000

Expression profiles and biological function.

Expression arrays facilitate the monitoring of changes in expression patterns of large collections of genes. It is generally expected that genes with similar expression patterns would correspond to proteins of common biological function. We assess this common assumption by comparing levels of similarity of expression patterns and statistical significance of biological terms that describe the corresponding protein functions. Terms are automatically obtained by mining large collections of Medline abstracts. We propose that the combined use of the tools for expression profiles clustering and automatic function retrieval, can be useful tools for the detection of biologically relevant associations between genes in complex gene expression experiments. The results obtained using publicly available experimental data show how, in general, an increase in the similarity of the expression patterns is accompanied by an enhancement of the amount of specific functional information or, in other words, how the selected terms became more specific following an increase in the specificity of the expression patterns. Particularly interesting are the discrepancies from this general trend, i.e. groups of genes with similar expression patterns but very little in common at the functional level. In these cases the similarity of their expression profiles becomes the first link between previously unrelated genes.

Cluster Analysis↗
PubMed1998

Protective immune response to foot-and-mouth disease virus with VP1 expressed in transgenic plants.

It has been reported recently that genes encoding antigens of bacterial and viral pathogens can be expressed in plants in a form in which they retain native immunogenic properties. The structural protein VP1 of foot-and-mouth disease virus (FMDV), which has frequently been shown to contain critical epitopes, has been expressed in different vectors and shown to induce virus-neutralizing antibodies and protection in experimental and natural hosts. Here we report the production of transformed plants (Arabidopsis thaliana) expressing VP1. Mice immunized with leaf plant extracts elicited specific antibody responses to synthetic peptides representing amino acid residues 135 to 160 of VP1, to VP1 itself, and to intact FMDV particles. Additionally, all of the immunized mice were protected against challenge with virulent FMDV. To our knowledge, this is the first study showing protection against a viral disease by immunization with an antigen expressed in a transgenic plant.

Animals↗
PubMed1984

Changes in EEG alpha power induced by repetitive ipsi- and contralateral hand movements.

Changes in alpha activity induced by hand movements, both ipsi and contralateral to left brain hemisphere were studied. Seven channels of EEG (F3, C3, P3, O1, T3, T5 and CZ referred to nasion) were processed by a minicomputer. The values which correspond to three tasks (rest, right hand and left hand movement) were analyzed by means of an ANOVA of three factors. Our data bring us to the following conclusions: The two movements (left and right hand) cannot be differentiated by alpha band power in any electrode position and both of them decrease the alpha power significantly. This decreasing effect is not homogeneous in the whole hemisphere, being greater in the central area.

Adult↗
PubMed1983

Brotizolam: a sleep laboratory evaluation.

Brotizolam 0.25 mg was evaluated in a sleep laboratory study of 10 normal subjects. The study covered 10 consecutive nights and included 4 placebo-baseline nights, 3 nights on the drug and 3 placebo-withdrawal nights, which permitted assessment of initial drug effects, side effects and withdrawal phenomena, such as rebound insomnia. There was a significant increase in total sleep time with drug administration; the improvement in sleep occurred primarily in the first third of the night following the onset of sleep. During the day after nightly drug administration, the presence of rebound anxiety was suggested by an increase in reports of anxiety/tension as compared to baseline. Following drug withdrawal there was a significant increase in total wake time above baseline level, to 40% above baseline on the first and third nights of withdrawal.

Azepines↗
PubMed1975

Comatose state maintained during eight years following a vascular ponto-mesencephalic lesion.

A 24-year-old man survived for 8 years after a vascular lesion of the pons and midbrain. During these years a subresponsive comatose state with neurological signs extending from the oculomotor nuclei to the trigeminal and facial nuclei levels was present. A decorticated type of rigidity, with bilateral paralysis of the limbs accompanied by pyramidal signs, was also present. The EEG during the first months showed slow activity which afterwards gradually changed towards fast and alpha activities, maintained in the course of the years. The pathological diagnosis was a fibrous endarteritis, mainly in the territory of the basilar and vertebral arteries. The pons and midbrain, presenting a large cystic infarct, were serially studied to determine the anatomical extent of the lesion. After reviewing other examples from the literature, the clinical features of our case are discussed. The evolution of the EEG is related to different structures of the ponto-mesencephalic region with different functional activities.

Adult↗
PubMedDate not supplied

[Silva's Method of mental control and changes in the EEG alpha rhythm].

Electroencephalographic recording was performed in 11 patients graded by the Silva's Method under basal conditions and under "dynamic meditation". Previous papers showed changes in the EEG of subjects who practice diverse methods of meditation and relaxation. Our results reveal a significant increase in the mean values of the alpha potency in occipital -01, 02- and temporal--T3, T4--areas, while subjects were practicing dynamic meditation.

Alpha Rhythm↗