Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Maps as Topic”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,243 records · Page 69Linked to original sources
PubMed2002

Modeling of activation data in the BrainMap database: detection of outliers.

We describe a system for meta-analytical modeling of activation foci from functional neuroimaging studies. Our main vehicle is a set of density models in Talairach space capturing the distribution of activation foci in sets of experiments labeled by lobar anatomy. One important use of such density models is identification of novelty, i.e., low probability database events. We rank the novelty of the outliers and investigate the cause for 21 of the most novel, finding several outliers that are entry and transcription errors or infrequent or non-conforming terminology. We briefly discuss the use of atlases for outlier detection.

Brain Mapping↗
PubMed2006

Exploring predictive and reproducible modeling with the single-subject FIAC dataset.

Predictive modeling of functional magnetic resonance imaging (fMRI) has the potential to expand the amount of information extracted and to enhance our understanding of brain systems by predicting brain states, rather than emphasizing the standard spatial mapping. Based on the block datasets of Functional Imaging Analysis Contest (FIAC) Subject 3, we demonstrate the potential and pitfalls of predictive modeling in fMRI analysis by investigating the performance of five models (linear discriminant analysis, logistic regression, linear support vector machine, Gaussian naive Bayes, and a variant) as a function of preprocessing steps and feature selection methods. We found that: (1) independent of the model, temporal detrending and feature selection assisted in building a more accurate predictive model; (2) the linear support vector machine and logistic regression often performed better than either of the Gaussian naive Bayes models in terms of the optimal prediction accuracy; and (3) the optimal prediction accuracy obtained in a feature space using principal components was typically lower than that obtained in a voxel space, given the same model and same preprocessing. We show that due to the existence of artifacts from different sources, high prediction accuracy alone does not guarantee that a classifier is learning a pattern of brain activity that might be usefully visualized, although cross-validation methods do provide fairly unbiased estimates of true prediction accuracy. The trade-off between the prediction accuracy and the reproducibility of the spatial pattern should be carefully considered in predictive modeling of fMRI. We suggest that unless the experimental goal is brain-state classification of new scans on well-defined spatial features, prediction alone should not be used as an optimization procedure in fMRI data analysis.

Artifacts↗
PubMed2006

Functional imaging analysis contest (FIAC) analysis according to AFNI and SUMA.

The Functional Imaging Analysis Contest (FIAC) datasets were analyzed with the AFNI software package. Two types of linear regression analyses were carried out: "fixed shape" hemodynamic response, where a preselected incomplete gamma function is used to model each brief activation episode, and "variable shape" analysis, where the temporal shape of the response model in each stimulus block class is allowed to vary separately in each voxel. These time series regressions were carried out both in the volume and on the original data projected to individual standardized cortical surface models. Intersubject analyses were carried out voxel-wise on the regression amplitudes obtained from these time series results, using a multi-way within-subject analysis of variance (ANOVA). Group analysis of the block design demonstrated a significant repetition suppression of the BOLD signal within blocks in the superior and middle temporal gyrus. This effect may represent differences in the response to the first stimulus following a period of silence compared to the remaining sentences in the block. Analyzing the event-related data, Brodmann area 31 showed significant sentence effect and consecutive-sentence repetition effect. However, no significant speaker effect was found; these results may be consistent with the instructions to the subjects that they would be tested on the sentence content. Sentence by speaker interaction effects were found in bilateral middle temporal gyrus, left inferior frontal, and left inferior temporal gyrus.

Brain Mapping↗
PubMed2006

Proteomics and Beyond: a report on the 3rd Annual Spring Workshop of the HUPO-PSI 21-23 April 2006, San Francisco, CA, USA.

The theme of the third annual Spring workshop of the HUPO-PSI was "proteomics and beyond" and its underlying goal was to reach beyond the boundaries of the proteomics community to interact with groups working on the similar issues of developing interchange standards and minimal reporting requirements. Significant developments in many of the HUPO-PSI XML interchange formats, minimal reporting requirements and accompanying controlled vocabularies were reported, with many of these now feeding into the broader efforts of the Functional Genomics Experiment (FuGE) data model and Functional Genomics Ontology (FuGO) ontologies.

Animals↗
PubMed2000

Isolation and characterization of murine orthologue of PTP-BK.

We isolated and characterized a murine orthologue of PTP-BK, a receptor-type protein tyrosine phosphatase expressed in brain and kidney. The deduced amino acid sequences showed 89, 95, and 92% identities with human, rabbit, and chicken homologues of PTP-BK. Mouse PTP-BK encodes a polypeptide of 1,226 amino acids with calculated molecular weight of 138,598 Da. The mature form of PTP-BK constitutes of 3 domain structures including extracellular, transmembrane, and a single intracellular PTPase domain. Western blot analysis indicated that anti-PTP-BK antibody specifically immunoreacted to 2 distinct molecules of 200 kDa and 220 kDa in COS cells, possibly due to differential glycosylation. The recombinant PTP-BK showed the phosphatase activity specific for the phosphotyrosine, but not for the phosphoserine residue of phosphopeptides in vitro. Radiation hybrid panel assigned mouse PTP-BK gene to 5.02cR distal to from the marker D6Mit339 on chromosome 6. Mouse PTP-BK was classified in PTPRO family in novel nomenclature. We discuss here the diversity and physiological functions of PTPRO family of PTP.

Amino Acid Sequence↗
PubMed2002

A database of [(11)C]WAY-100635 binding to 5-HT(1A) receptors in normal male volunteers: normative data and relationship to methodological, demographic, physiological, and behavioral variables.

PET studies of [(11)C]WAY-100635 binding are proving to be a useful tool to evaluate 5-HT(1A) receptor function in vivo in humans. We describe the pattern of [(11)C]WAY-100635 binding in 61 healthy male brains and examine its variability. For all PET scans, binding potential (BP) values for [(11)C]WAY-100635 in different regions were calculated using a simplified reference tissue model, with the cerebellum as reference region. Specifically we describe (1) region of interest and SPM databases of PET [(11)C]WAY-100635 binding, including test-retest variability; (2) the sensitivity of [(11)C]WAY-100635 binding to manipulations of endogenous 5-HT; and (3) correlations between [(11)C]WAY-100635 binding and radiochemical, demographic, physiological, and behavioral variables. The regional distribution of [(11)C]WAY-100635 binding in healthy human brain was similar to that reported in vitro. The test-retest variability was approximately 12% (range 9-16%) and was similar for all methods of regional sampling. The binding of [(11)C]WAY-100635 was insensitive to changes in brain 5-HT induced by tryptophan infusion and depletion. Although BP values varied greatly across subjects (range 2.9-6.8), there were no significant correlations of regional and global BP with common radiochemical, demographic, physiological, and personality variables. Specifically, in contrast with two recent small studies, we found no decline of [(11)C]WAY-100635 binding with age in our large cohort over the age range of 24 to 53 years. Assessment of 5-HT(1A) receptors in vivo using PET and [(11)C]WAY-100635 gives reliable measures of 5-HT(1A) binding. The large between-subject variability observed could not be explained by common methodological, physiological, or behavioral factors and hence the biological basis of this variability remains to be clarified.

Adult↗
PubMed1983

Is there a general relationship between estimated chromosome distances in interphase and location of genes with related functions?

The problem of a possible clustering of human chromosomes containing genes with related functions was examined in the interphase nucleus of lymphocytes by a statistical comparison of distances between chromosomes containing such functionally related genes with all sets of chromosome distances. The gene locus assignments were taken from a recent review (McKusick 1982); the chromosomal distances were those estimated by Hager et al. (1982) from the frequencies of reunion figures between specific chromosomes as observed in chromosome instability syndromes (Fanconi anemia, Bloom syndrome) and after treatment with Trenimon. Chromosomal distances had been estimated by multidimensional scaling. There was no general tendency for closer location of chromosomes containing genes with related function. A few such chromosomes do show below average distances but this could easily be a chance result.

Cell Nucleus↗
PubMed1998

[Semiologic classification of epileptic seizures].

Recent advances in epileptology and epilepsy surgery require revision of the currently used International Classification of Epileptic Seizures, which was published 1981. We present a classification of epileptic seizures which is based purely on the clinical seizure semiology. The advantages of a semiological seizure classification are stressed.

Brain Mapping↗
PubMed2004

Identification of 45 novel SNPs in the 83-kb region containing peptidylarginine deiminase types 1 and 3 loci on chromosomal band 1p36.13.

Peptidylarginine deiminases (PADIs) are post-translational modification enzymes that catalyze the conversion of protein-bound arginine residues into citrulline residues in the presence of calcium ions. Among PADIs, PADI4 was identified as a rheumatoid arthritis-susceptibility gene (Suzuki et al. in Nat Genet 34:395, 2003). We identified a total of 87 single nucleotide polymorphisms (SNPs) in PADI1 and PADI3 gene loci. Following a comparison of our data with SNPs in the dbSNP database in the National Center for Biotechnology Information, 45 SNPs are considered to be novel: 33 were identified in the PADI1 gene locus and 12 in the PADI3 gene locus. We also identified two insertion-deletion polymorphisms in introns of the PADI1. The high-resolution map that we constructed in this study will serve as a useful resource for analyzing gene scans of complex diseases mapped to this local segment on chromosomal band 1p36.13.

Chromosome Banding↗
PubMed2001

High-density single-nucleotide polymorphism (SNP) map in the 96-kb region containing the entire human DiGeorge syndrome critical region 2 (DGCR2) gene at 22q11.2.

We constructed a high-density single-nucleotide polymorphism (SNP) map in the 96-kb region containing the DiGeorge syndrome critical region 2 (DGCR2) gene at chromosome 22q11.2, a human counterpart of mouse seizure-related gene SEZ-12. A total of 102 SNPs were isolated from the region by systematic screening among 48 Japanese individuals: 9 SNPs in the 5' flanking region, 3 in the 5' untranslated region, 2 in the coding regions, 77 in introns, 7 in the 3' untranslated region, and 4 in the 3' flanking region. By a comparison of our data with SNPs deposited in the dbSNP database in the National Center for Biotechnology Information, 80 SNPs (78.4%) were considered to be novel. The ratio of transition to transversion was 3.08:1. In addition, eight other types of genetic variations (one GA dinucleotide polymorphism and seven insertion/deletion polymorphisms) were discovered. The high-resolution map that we constructed will be a useful resource for analyzing gene scans of complex diseases mapped to this local segment on chromosome 22.

3' Untranslated Regions↗
PubMed2000

Strategies for catheter ablation of scar-related ventricular tachycardia.

Ventricular tachycardia (VT) due to reentry in and around regions of ventricular scar from an old myocardial infarction or cardiomyopathic process is often a difficult management problem. Radiofrequency catheter ablation is an option for controlling frequent VT episodes. Patient and VT characteristics determine the mapping and ablation approach and efficacy. In patients with a VT that is hemodynamically tolerated to allow mapping, prevention of recurrent VT is achieved in 54% to 66% of patients with a procedure related mortality of 1% to 2.7%. Multiple morphologies of monomorphic VT and circuits that are located deep to the endocardium are common problems that reduce efficacy. Mapping to identify target regions for ablation can be difficult if VT is rapid and not tolerated, or not inducible. Ablation of these "unmappable VTs" by designing ablation lines or areas based on the characteristics of the scar as assessed during sinus rhythm, and using approaches to assess global activation from a limited number of beats has been shown to be feasible. Ablation of multiple VTs, epicardial VTs, and poorly tolerated VTs are feasible. Future studies defining efficacy and risks are needed.

Body Surface Potential Mapping↗
PubMed1991

A statistical evaluation of the main interpolation methods applied to 3-dimensional EEG mapping.

This paper is a review of the main interpolation methods applicable to 3-dimensional EEG mapping. The use of simple statistical comparison methods on recorded EEG maps allowed us to evaluate the qualities of interpolation methods belonging to 3 mathematical families (barycentric, polynomial, spline). A combination of a 3-dimensional representation of EEG maps and a reliable interpolation method makes it possible to obtain better spatial resolution than with standard planar mapping.

Brain Mapping↗