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Dissociation
Kinds of Dissociation Terms modified by Dissociation Selected AbstractsA collection of 11 800 single-copy Ds transposon insertion lines in ArabidopsisTHE PLANT JOURNAL, Issue 6 2004Takashi Kuromori Summary More than 10 000 transposon-tagged lines were constructed by using the Activator (Ac)/Dissociation (Ds) system in order to collect insertional mutants as a useful resource for functional genomics of Arabidopsis. The flanking sequences of the Ds element in the 11 800 independent lines were determined by high-throughput analysis using a semi-automated method. The sequence data allowed us to map the unique insertion site on the Arabidopsis genome in each line. The Ds element of 7566 lines is inserted in or close to coding regions, potentially affecting the function of 5031 of 25 000 Arabidopsis genes. Half of the lines have Ds insertions on chromosome 1 (Chr. 1), in which donor lines have a donor site. In the other half, the Ds insertions are distributed throughout the other four chromosomes. The intrachromosomal distribution of Ds insertions varies with the donor lines. We found that there are hot spots for Ds transposition near the ends of every chromosome, and we found some statistical preference for Ds insertion targets at the nucleotide level. On the basis of systematic analysis of the Ds insertion sites in the 11 800 lines, we propose the use of Ds -tagged lines with a single insertion in annotated genes for systematic analysis of phenotypes (phenome analysis) in functional genomics. We have opened a searchable database of the insertion-site sequences and mutated genes (http://rarge.gsc.riken.go.jp/) and are depositing these lines in the RIKEN BioResource Center as available resources (http://www.brc.riken.go.jp/Eng/). [source] The Attentional Resource Allocation Scale (ARAS): psychometric properties of a composite measure for dissociation and absorption,DEPRESSION AND ANXIETY, Issue 8 2010R. N. Carleton M.A. Abstract Background: Differences in attentional processes have been linked to the development and maintenance of psychopathology. Shifts in such processes have been described by the constructs Dissociation and Absorption. Dissociation occurs when external and/or internal stimuli are excluded from consciousness due to discrepant, rather than unitary, manifestations of cognitive awareness [Erdelyi MH. 1994: Int J Clin Exp Hypnosis 42:379,390]. In contrast, absorption can be conceptualized by a focus on limited stimuli, to the exclusion of other stimuli, because of unifying, rather than discrepant, manifestations of cognitive awareness. The Dissociative Experiences Scale [DES; Bernstein EM, Putnam FW. 1986: J Nerv Ment Dis 174:727,735] and Tellegen Absorption Scale [TAS; Tellegen A, Atkinson G. 1974: J Abnorm Psychol 83:268,277] are common measures of each construct; however, no factor analyses are available for the TAS and despite accepted overlap, no one has assessed the DES and TAS items simultaneously. Previous research suggests the constructs and factor structures need clarification, possibly including more parsimonious item inclusion [Lyons LC, Crawford HJ. 1997: Person Individ Diff 23:1071,1084]. The purpose of this study was to evaluate the factor structure of the DES and TAS and create a psychometrically stable measure of Dissociation and Absorption. Methods: This study included data from an undergraduate (n=841; 76% women) and a community sample (n=233; 86% women) who each completed the DES and TAS. Results: Exploratory factor analyses [Osborne JW (ed). 2008: Best Practices in Quantitative Methods. Los Angeles: Sage Publications Inc.] with all DES and TAS items suggested a 15-item 3-factor solution (i.e., imaginative involvement, dissociative amnesia, attentional dissociation). Confirmatory factor analyses resulted in excellent fit indices for the same solution. Conclusions: The items and factors were conceptualized in line with precedent research as the Attentional Resource Allocation Scale (ARAS). Comprehensive results, implications, and future research directions are discussed. Depression and Anxiety, 2010. © 2010 Wiley-Liss, Inc. [source] Collagenase-Assisted Fat Dissociation for Autologous Fat TransferDERMATOLOGIC SURGERY, Issue 10 2008DAVID K. MOSCATELLO PHD BACKGROUND The quality of fat for autologous transfer procedures has been a major focus of research in the past few years. The primary goal of these efforts is to improve the viability and longevity of the graft in human subjects. One possible factor in the permanence of theses transplants is the size of the adipose tissue grafts. OBJECTIVE This study evaluated the effects of collagenase digestion on the viability of human adipose tissue. MATERIALS AND METHODS Samples of fat were obtained from subjects undergoing tumescent liposuction. The tissue was digested in a variety of concentrations of collagenase using optimized methods of processing. The digested fat was also subjected to mock injections through small bore needles. RESULTS Eight subjects completed the study. The viability of the fat using the optimized methods of collagenase digestion was consistently higher than 79%. During the mock injection trials, the viability of fat was improved from approximately 17% to 84% by collagenase digestion. CONCLUSIONS Our results show increased viability of human adipose tissue when digested by collagenase. These techniques can be applied to human autologous lipoaugmentation procedures in an effort to improve longevity of the transplanted tissue. [source] Specification of the enveloping layer and lack of autoneuralization in zebrafish embryonic explantsDEVELOPMENTAL DYNAMICS, Issue 1 2005Charles G. Sagerström Abstract We have analyzed the roles of cell contact during determination of the outermost enveloping layer (EVL) and deeper neurectoderm in zebrafish embryos. Outer cells, but not deeper cells, are specified to express the EVL-specific marker, cyt1 by late blastula. EVL specification requires cell contact or close cell proximity, because cyt1 is not expressed after explant dissociation. The EVL may be homologous to the Xenopus epithelial layer, including the ventral larval epidermis. While Xenopus epidermal cytokeratin gene expression is activated by bone morphogenetic protein (BMP) signaling, zebrafish cyt1 is not responsive to BMPs. Zebrafish early gastrula ectodermal explants are specified to express the neural markers opl (zic1) and otx2, and this expression is prevented by BMP4. Dissociation of zebrafish explants prevents otx2 and opl expression, suggesting that neural specification in zebrafish requires cell contact or close cell proximity. This finding is in contrast to the case in Xenopus, where ectodermal dissociation leads to activation of neural gene expression, or autoneuralization. Our data suggest that distinct mechanisms direct development of homologous lineages in different vertebrates. Developmental Dynamics 232:85,97, 2005. © 2004 Wiley-Liss, Inc. [source] Real Time Electrochemical Monitoring of DNA/PNA Dissociation by Melting Curve AnalysisELECTROANALYSIS, Issue 14 2009Xiaoteng Luo Abstract An immobilization-free electrochemical method is reported for real-time monitoring of the DNA hybrid dissociation between a ferrocene labeled peptide nucleic acid (PNA) and a fully-complementary or single-base-mismatched DNA. This method takes advantages of electrostatic charge characteristics and interactions among the neutrally charged PNA, the negatively charged DNA and the negatively charged electrode surface made of indium tin oxide (ITO). When a ferrocene labeled PNA (Fc-PNA) sequence is hybridized to a complementary DNA strand, electrostatic repulsion between the negatively charged PNA/DNA hybrid and the negative ITO surface retards the diffusion of the electroactive Fc to the electrode, resulting in a much reduced electrochemical signal. On the other hand, when the Fc-PNA is dissociated from the hybrid at elevated temperatures, the neutrally charged Fc-PNA easily diffuses to the electrode with an enhanced electrochemical signal. Therefore, an electrochemical melting curve of the Fc-PNA/DNA hybrid can be obtained by measuring the Fc signal with the increasing temperature. This strategy allows monitoring of the dissociation of the DNA hybrid in real time, which might lead to a simple detection method for single nucleotide polymorphism (SNP) analysis. [source] Distress, Dissociation, and Embodied Experience: Reconsidering the Pathways to Mediumship and Mental HealthETHOS, Issue 1 2005REBECCA SELIGMAN This article explores the biocultural bases of spirit possession mediumship in the Afro-Brazilian religion, Candomblé. After a brief review of the literature, the article moves beyond the biomedical and social-structural explanations that have dominated the theoretical landscape, by attempting to construct an etiology of mediumship that is traced through the interface of individual characteristics with the cultural belief system that forms their context. Data were collected from a total of 71 individuals over the course of a year-long field study in Salvador, Brazil. Analyses of social ethnography, life history and semistructured interviews along with results from psychological inventories, suggest that altered states of consciousness should not be considered the central and defining element of mediumship. An alternative model is proposed, in which the combination of social conditions and somatic susceptibilities causes certain individuals to identify with the mediumship role, and predisposes them to dissociate. However in the context of Candomblé, dissociation is not a pathological experience, but rather a therapeutic mechanism, learned through religious participation, that benefits individuals with a strong tendency to somatize. [source] Strong Evidence for an Unprecedented Borderline Case of Dissociation and Cycloaddition in Open-Shell 1,3-Dipole Chemistry: Transient Nitrilium Phosphane-Ylide Complex Radical CationsEUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 22 2009Holger Helten Abstract The reaction of 3-ferrocenyl-substituted 2H -azaphosphirene complexes 1a,c in the presence of substoichiometric amounts of ferrocenium hexafluorophosphate yields 3,5-diferrocenyl-substituted 2H -1,4,2-diazaphosphole complexes 3a,c and difluoro(organo)phosphane complexes 4a,c. The reaction of 1a,c and [FcH]PF6 with cyanoferrocene yields 3a,c in a straightforward way. The molecular structures of 3a,c were unambiguously identified by multinuclear NMR spectroscopic experiments, mass spectrometry, and single-crystal X-ray diffraction studies. DFT calculations on model complexes 1d,m and 3d,m reveal a close similarity of Mo and W complexes (vs. Cr) and a strong influence of the ferrocenyl substituent on the geometry, spin, and charge distribution of reactive intermediates and the reaction course. Strong support for the assumption of a dissociation,cycloaddition reaction sequence leading to 3 and thus a surprising "cannibalistic" reaction was obtained.(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009) [source] Dissociation of function between the dorsal and the ventral hippocampus in spatial learning abilities of the rat: a within-subject, within-task comparison of reference and working spatial memoryEUROPEAN JOURNAL OF NEUROSCIENCE, Issue 3 2004Helen H. J. Pothuizen Abstract Lesions restricted to the dorsal, but not the ventral, hippocampus severely impair the formation of spatial memory. This dissociation was first demonstrated using the water maze task. The present study investigated whether the dorsal and the ventral hippocampus are involved differentially in spatial reference and spatial working memory using a four-baited/four-unbaited version of the eight-arm radial maze task. This test allows the concurrent evaluation of reference and working memory with respect to the same set of spatial cues, and thereby enables a within-subjects within-task comparison between the two forms of memory functions. Rats with N -methyl- d -aspartic acid-induced excitotoxic lesions of the dorsal hippocampus, ventral hippocampus or both were compared with sham and unoperated controls. We showed that dorsal lesions were as effective as complete lesions in severely disrupting both reference and working spatial memory, whereas rats with ventral lesions performed at a level comparable with controls. These results lend further support to the existence of a functional dissociation between the dorsal and the ventral hippocampus, with the former being preferentially involved in spatial learning. [source] Dissociation between top-down attentional control and the time course of visual attention as measured by attentional dwell time in patients with mild cognitive impairmentEUROPEAN JOURNAL OF NEUROSCIENCE, Issue 2 2003Richard J. Perry Abstract Studies of the time course of visual attention have identified a temporary functional blindness to the second of sequentially presented stimuli in that the attentional cost of attending to one visual stimulus may lead to impairments in identifying a second stimulus presented within 500 ms of the first. This phenomenon is known as the attentional blink or attentional dwell time. The neural correlates of the attentional blink and its relationship to mechanisms that control attention are unknown. To examine this relationship we tested healthy controls and subjects in the preclinical stage of Alzheimer's disease, known as mild cognitive impairment (MCI), on a paradigm which affords quantification of both the attentional blink and the top-down control of attention. When subjects were asked to identify both a number and a letter that were rapidly and sequentially presented on a visual display, the detrimental effect that identifying the first stimulus had on the ability to identify the second served as a measure of the attentional blink. When asked to identify only one of the two stimuli, the ability to ignore the first stimulus was a function of their top-down attentional control. The MCI subjects demonstrated a normal attentional dwell time but in contrast they showed impaired top-down attentional control within the same paradigm. This dissociation suggests that these two aspects of visual attention are subserved by different neural systems. The possible neural correlates of these two attentional functions are discussed. [source] Redistribution of small GTP-binding protein, Rab27B, in rat parotid acinar cells after stimulation with isoproterenolEUROPEAN JOURNAL OF ORAL SCIENCES, Issue 3 2009Akane Imai Small GTP-binding protein, Rab27, has been implicated in the regulation of different types of membrane trafficking, including melanosome transport in melanocytes and regulated secretion events in a wide variety of secretory cells. We have previously shown that Rab27 is involved in the control of isoproterenol (IPR)-induced amylase release from rat parotid acinar cells. Although Rab27 is predominantly localized on secretory granules under resting conditions, changes to its intracellular localization after ,-stimulation have never been elucidated. The present study investigated IPR-induced redistribution of Rab27B in the parotid acinar cells, revealing translocation from secretory granules to the subapical region after 5 min of IPR treatment and then diffusion into the cytosol after 30 min of IPR treatment. Dissociation of Rab27B from the apical plasma membrane is probably mediated through the Rab GDP dissociation inhibitor (GDI) in the cytosol extracting GDP-bound Rab protein from membranes, as a dramatic increase in the amount of the Rab27B,GDI complex in the cytosol was observed 30 min after stimulation with IPR. These results indicate that, in parotid acinar cells, Rab27B is translocated, in a time-dependent manner, from secretory granules into the apical plasma membrane as a result of exposure to IPR, and then into the cytosol through binding with the GDI. [source] A Graphene Oxide,Streptavidin Complex for Biorecognition , Towards Affinity PurificationADVANCED FUNCTIONAL MATERIALS, Issue 17 2010Zunfeng Liu Abstract In our postgenomic era, understanding of protein-protein interactions by characterizing the structure of the corresponding protein complex is becoming increasingly important. An important problem is that many protein complexes are only stable for a few minutes. Dissociation will occur when using the typical, time-consuming purification methods such as tandem affinity purification and multiple chromatographic separations. Therefore, there is an urgent need for a quick and efficient protein-complex purification method for 3D structure characterization. The graphene oxide (GO)·streptavidin complex is prepared via a GO·biotin·streptavidin strategy and used for affinity purification. The complex shows a strong biotin recognition capability and an excellent loading capacity. Capturing biotinylated DNA, fluorophores and Au nanoparticles on the GO·streptavidin complexes demonstrates the usefulness of the GO·streptavidin complex as a docking matrix for affinity purification. GO shows a high transparency towards electron beams, making it specifically well suited for direct imaging by electron microscopy. The captured protein complex can be separated via a filtration process or even via on-grid purification and used directly for single-particle analysis via cryo-electron microscopy. Therefore, the purification, sample preparation, and characterization are rolled into one single step. [source] Dissociation of food and opiate preference by a genetic mutation in zebrafishGENES, BRAIN AND BEHAVIOR, Issue 7 2006B. Lau Both natural rewards and addictive substances have the ability to reinforce behaviors. It has been unclear whether identical neural pathways mediate the actions of both. In addition, little is known about these behaviors and the underlying neural mechanisms in a genetically tractable vertebrate, the zebrafish Danio rerio. Using a conditioned place preference paradigm, we demonstrate that wildtype zebrafish exhibit a robust preference for food as well as the opiate drug morphine that can be blocked by the opioid receptor antagonist naloxone. Moreover, we show that the too few mutant, which disrupts a conserved zinc finger-containing gene and exhibits a reduction of selective groups of dopaminergic and serotonergic neurons in the basal diencephalon, displays normal food preference but shows no preference for morphine. Pretreatment with dopamine receptor antagonists abolishes morphine preference in the wildtype. These studies demonstrate that zebrafish display measurable preference behavior for reward and show that the preference for natural reward and addictive drug is dissociable by a single-gene mutation that alters subregions of brain monoamine neurotransmitter systems. Future genetic analysis in zebrafish shall uncover further molecular and cellular mechanisms underlying the formation and function of neural circuitry that regulate opiate and food preference behavior. [source] Insertion of Molecular Oxygen in Transition-Metal Hydride Bonds, Oxygen-Bond Activation, and Unimolecular Dissociation of Metal Hydroperoxide Intermediates.HELVETICA CHIMICA ACTA, Issue 3 2008Short Communication Abstract Thermal activation of molecular oxygen is observed for the late-transition-metal cationic complexes [M(H)(OH)]+ with M=Fe, Co, and Ni. Most of the reactions proceed via insertion in a metalhydride bond followed by the dissociation of the resulting metal hydroperoxide intermediate(s) upon losses of O, OH, and H2O. As indicated by labeling studies, the processes for the Ni complex are very specific such that the O-atoms of the neutrals expelled originate almost exclusively from the substrate O2. In comparison to the [M(H)(OH)]+ cations, the ionmolecule reactions of the metal hydride systems [MH]+ (M=Fe, Co, Ni, Pd, and Pt) with dioxygen are rather inefficient, if they occur at all. However, for the solvated complexes [M(H)(H2O)]+ (M=Fe, Co, Ni), the reaction with O2 involving OO bond activation show higher reactivity depending on the transition metal: 60% for the Ni, 16% for the Co, and only 4% for the Fe complex relative to the [Ni(H)(OH)]+/O2 couple. [source] Dissociation between liver inflammation and hepatocellular damage induced by carbon tetrachloride in myeloid cell,specific signal transducer and activator of transcription 3 gene knockout mice,HEPATOLOGY, Issue 5 2010Norio Horiguchi Liver injury is associated with inflammation, which is generally believed to accelerate the progression of liver diseases; however, clinical data show that inflammation does not always correlate with hepatocelluar damage in some patients. Investigating the cellular mechanisms underlying these events using an experimental animal model, we show that inflammation may attenuate liver necrosis induced by carbon tetrachloride (CCl4) in myeloid-specific signal transducer and activator of transcription 3 (STAT3) knockout mice. As an important anti-inflammatory signal, conditional deletion of STAT3 in myeloid cells results in markedly enhanced liver inflammation after CCl4 injection. However, these effects are also accompanied by reduced liver necrosis, correlating with elevated serum interleukin-6 (IL-6) and hepatic STAT3 activation. An additional deletion of STAT3 in hepatocytes in myeloid-specific STAT3 knockout mice restored hepatic necrosis but decreased liver inflammation. Conclusion: Inflammation-mediated STAT3 activation attenuates hepatocellular injury induced by CCl4 in myeloid-specific STAT3 knockout mice, suggesting that inflammation associated with a predominance of hepatoprotective cytokines that activate hepatic STAT3 may reduce rather than accelerate hepatocellular damage in patients with chronic liver diseases. Hepatology 2010 [source] Dissociation between MEG alpha modulation and performance accuracy on visual working memory task in obsessive compulsive disorderHUMAN BRAIN MAPPING, Issue 12 2007Kristina T. Ciesielski Abstract Oscillatory brain activity in the alpha band (8,13 Hz) is modulated by cognitive events. Such modulation is reflected in a decrease of alpha (event-related desynchronization; ERD) with high cognitive load, or an increase (event-related synchronization) with low cognitive demand or with active inhibition of distractors. We used magnetoencephalography to investigate the pattern of prefrontal and parieto-occipital alpha modulation related to two variants of visual working memory task (delayed matching-to-sample) with and without a distractor. We tested nonmedicated, nondepressed patients suffering obsessive-compulsive disorder (OCD), and pair-matched healthy controls. The level of event-related alpha as a function of time was estimated using the temporal-spectral evolution technique. The results in OCD patients indicated: (1) a lower level of prestimulus (reference) alpha when compared to controls, (2) a task-phase specific reduction in event-related alpha ERD in particular for delayed matching-to-sample task with distractor, (3) no significant correlations between the pattern of modulation in prefrontal and parietal-occipital alpha oscillatory activity. Despite showing an abnormally low alpha modulation, the OCD patients' performance accuracy was normal. The results suggest a relationship of alpha oscillations and the underlying thalamocortical network to etiology of OCD and an involvement of a compensatory mechanism related to effortful inhibition of extrinsic and intrinsic interference. Hum Brain Mapp 2007. © 2007 Wiley-Liss, Inc. [source] Dissociation between objective psychomotor impairment and subjective sleepiness after diazepam administration in the aged peopleHUMAN PSYCHOPHARMACOLOGY: CLINICAL AND EXPERIMENTAL, Issue 6 2007Masaru Echizenya Abstract The aim of the present study was to clarify whether subjective sleepiness accurately reflects benzodiazepine-related decline in psychomotor function after taking benzodiazepines (BZPs) in aged people. Subjects were eight healthy, young (mean age, 19.8,years) and seven healthy, older (mean age, 60.9,years) men. Placebo and diazepam (DZP) were administered orally in a single-blind crossover manner to the young subjects (placebo, 5,mg DZP and 10,mg DZP) and to the older subjects (placebo and 5,mg DZP). Plasma drug concentration, choice reaction time (CRT) as an objective measure of psychomotor function, and the Stanford Sleepiness Scale (SSS) as a measure of subjective sleepiness were monitored every 20,min from 1000 until 1600,h, being the drug administered at 1200,h. Pharmacokinetic variables did not differ significantly between the two age groups. DZP at 10,mg in young subjects induced significant increases in both the CRT and SSS score. DZP at 5,mg induced no significant increase in SSS score in either age group but did induce a significant increase in CRT only in the older subjects that matched that in young subjects given 10,mg DZP. The older subjects suffered from dissociation between subjective sleepiness and objective psychomotor impairment under DZP treatment. Such individuals may underestimate the detrimental effects on brain function. Copyright © 2007 John Wiley & Sons, Ltd. [source] Saturation, Relaxation, and Dissociation of Excited Triplet Excitons in Conjugated PolymersADVANCED MATERIALS, Issue 8 2009Xudong Yang Femtosecond pump-probe spectroscopy is used to measure the excited state absorption dynamics in triplet excitons generated by continuous wave excitation of a conjugated polymer. Saturation of the T1,Tn transition is observed, allowing a cross-section of 2.0,×,10,16,cm2 to be established. Relaxation to T1 occurs with a 300,fs timescale, but 20% of Tn states dissociate into charges. [source] Nitric Acid Dissociation at an Aqueous Surface: Occurrence and MechanismISRAEL JOURNAL OF CHEMISTRY, Issue 2 2009Shuzhi Wang Here we briefly review some highlights of our recent work on the acid dissociation of nitric acid HNO3 at an aqueous surface, a proton transfer reaction of interest not only from a fundamental perspective, but also in connection with heterogeneous chemistry in a wide range of atmospheric contexts. Two types of studies of the potential acid dissociation are discussed, quantum chemical reaction path calculations to assess the reaction free energy and Car-Parrinello molecular dynamics simulations to assess the reaction feasibility. We discuss the agreement and disagreement between the predictions of these two calculations as a function of the initial location of the HNO3 molecule, ranging from a positioning on top of the aqueous surface to one several water layers below the surface. Special attention is given to the four key water solvent motions found to be necessary for the proton transfer reaction to occur. Finally, an Eigen cation, rather than a Zundel cation, is in all cases found to be predominant next to the nitrate ion in contact ion pairs produced in the acid dissociation. This predominance remains, although diminished, for solvent-separated ion pairs. [source] Mechanical Prosthetic Valve Dysfunction Causing Pulsus Alternans Leading to Intermittent Electromechanical Dissociation: A Case Report and Literature ReviewJOURNAL OF CARDIAC SURGERY, Issue 6 2007Vasha Kaur M.B.Ch.B. (Hons) She initially developed pulsus alternans which led, over a few hours, to intermittent electromechanical dissociation. Clinical and echocardiographic findings are described. Emergency surgical intervention revealed a piece of chorda wedged between the disc occluder and the valve ring. This case illustrates clinical and Doppler echocardiographic features associated with a rare presentation of an unusual perioperative complication of prosthetic mitral valve dysfunction. We have also included a brief review of related literature. [source] Dissociation Between Coronary Sinus and Left Atrial Conduction in Patients with Atrial Fibrillation and FlutterJOURNAL OF CARDIOVASCULAR ELECTROPHYSIOLOGY, Issue 6 2001GJIN NDREPEPA M.D. Dissociation Between CS and LA Conduction.Introduction: Coronary sinus (CS) recordings are routinely used during electrophysiologic studies for various supraventricular and ventricular arrhythmias with the understanding that they represent left atrial (LA) activity. However, the behavior of CS electrical activity during atrial arrhythmias has not drawn any special attention beyond standard considerations. Methods and Results: The study population consisted of 9 patients (3 women; mean age 59 ± 11 years) with atrial fibrillation (AF) and atrial flutter (AFL) who developed dissociation of conduction between the CS and posterior LA during spontaneous AF and AFL. In all patients, the LA and the CS were mapped using a 64-electrode basket catheter and a multipolar electrode catheter, respectively. The right atrium (RA) was mapped simultaneously using a 24-polar electrode catheter (7 patients) or a 64-electrode basket catheter (2 patients). Eight patients showed stable double potentials in CS recordings during AF (9 episodes) and AFL (3 episodes). During ongoing arrhythmias, the first row of potentials maintained a constant relationship with the RA activity, whereas the second row of potentials was discordant with the posterior wall of the LA in 7 patients and concordant in 2 patients. In 1 patient with counterclockwise AFL, CS activation was isolated from the posterior wall of the RA until it reached the distal portion of the CS, after which it entered the lateral region of the LA. In 1 patient, a macroreentrant LA tachycardia involving CS muscle was observed. Rapid atrial pacing from the proximal CS and extrastimuli produced longitudinal dissociation of CS activation in all patients. Conclusion: Conduction between the CS and posterior LA can be dissociated during spontaneous atrial arrhythmias and provocative proximal CS pacing. [source] Atrioventricular Nodal Tachycardia Occurring During Atrial FibrillationJOURNAL OF CARDIOVASCULAR ELECTROPHYSIOLOGY, Issue 7 2000JANE CHEN M.D. AVNRT During Atrial Fibrillation. We describe the case of a 32-year-old woman with palpitations and atrial fibrillation (AF) as the only documented arrhythmia. The patient underwent electrophysiologic study and was found to have inducible AV nodal reentrant tachycardia (AVNRT). During a prolonged episode of AVNRT, AF developed in both atria, hut AVNRT persisted. Dissociation of the atria during AVNRT is evidence that the atrium is not necessary in AVNRT. This case also illustrates the utility of an electrophysiologic study in locating a potentially curable arrhythmia as the primary cause of AF in young patients. [source] Dissociation of growth arrest and CYP24 induction by VDR ligands in mammary tumor cellsJOURNAL OF CELLULAR BIOCHEMISTRY, Issue 6 2007Meggan E. Valrance Abstract Murine mammary tumor cells with differential vitamin D receptor (VDR) expression were used to study the mechanisms of growth inhibition by vitamin D steroids. In VDR-expressing WT145 cells, 1,25D and its synthetic analog EB1089 induce growth arrest and transcriptionally upregulate the well-characterized VDR target gene CYP24. 1,25D also induces apoptosis in WT145 cells through activation of initiator and executioner caspases and the calcium-dependent protease calpain. We also demonstrate that WT145 cells express CYP27B1, the enzyme that converts 25-hydroxyvitamin D3 (25D) to 1,25D, and that 25D inhibits growth of these cells but does not trigger apoptosis or induce CYP24 expression. Comparative studies were conducted in KO240 cells, which were derived from VDR knockout mice and found to retain expression of CYP27B1. KO240 cells were not growth inhibited nor rendered apoptotic by any of the tested vitamin D compounds. These data conclusively demonstrate that VDR mediates the anti-proliferative and pro-apoptotic effects of vitamin D metabolites and analogs, but that the potency of a vitamin D compound to induce the VDR target gene CYP24 does not accurately predict its potency in mediating growth regulation. J. Cell. Biochem. 101: 1505,1519, 2007. © 2007 Wiley-Liss, Inc. [source] Treatment of Trauma- and Abuse-Related Dissociative Symptom Disorders in Children and AdolescentsJOURNAL OF CHILD AND ADOLESCENT PSYCHIATRIC NURSING, Issue 1 2009Scott Weber EdD TOPIC:,Dissociation is believed to be one of the most common underlying psychological processes among children and adolescents receiving mental health treatment, but most of the dissemination of information about dissociation has occurred among psychiatrists and psychologists. PURPOSE:,Modes of treatment for dissociation as it affects children and adolescents are described. SOURCES USED:,Current research and practice scholarly articles on treatment of children and adolescents for dissociation and dissociative symptom disorders were accessed and critically reviewed. CONCLUSIONS:,Prognosis in children and adolescents can vary widely among patients and between the specific types of dissociation disorder; however, expert clinicians and researchers agree that early, intense treatment offers the greatest possibility of full recovery. [source] Kinetic and thermodynamic characterization of HIV-1 protease inhibitorsJOURNAL OF MOLECULAR RECOGNITION, Issue 2 2004Cynthia F. Shuman Abstract Interaction kinetic and thermodynamic analyses provide information beyond that obtained in general inhibition studies, and may contribute to the design of improved inhibitors and increased understanding of molecular interactions. Thus, a biosensor-based method was used to characterize the interactions between HIV-1 protease and seven inhibitors, revealing distinguishing kinetic and thermodynamic characteristics for the inhibitors. Lopinavir had fast association and the highest affinity of the tested compounds, and the interaction kinetics were less temperature-dependent as compared with the other inhibitors. Amprenavir, indinavir and ritonavir showed non-linear temperature dependencies of the kinetics. The free energy, enthalpy and entropy (,G, ,H, ,S) were determined, and the energetics of complex association (,Gon, ,Hon, ,Son) and dissociation (,Goff, ,Hoff, ,Soff) were resolved. In general, the energetics for the studied inhibitors was in the same range, with the negative free energy change (,G,<,0) due primarily to increased entropy (,S,>,0). Thus, the driving force of the interaction was increased degrees of freedom in the system (entropy) rather than the formation of bonds between the enzyme and inhibitor (enthalpy). Although the ,Gon and ,Goff were in the same range for all inhibitors, the enthalpy and entropy terms contributed differently to association and dissociation, distinguishing these phases energetically. Dissociation was accompanied by positive enthalpy (,Hoff,>,0) and negative entropy (,Soff,<,0) changes, whereas association for all inhibitors except lopinavir had positive entropy changes (,Son,>,0), demonstrating unique energetic characteristics for lopinavir. This study indicates that this type of data will be useful for the characterization of target,ligand interactions and the development of new inhibitors of HIV-1 protease. Copyright © 2004 John Wiley & Sons, Ltd. [source] S-Adenosyl-L-Methionine Co-administration Prevents the Ethanol-Elicited Dissociation of Hepatic Mitochondrial Ribosomes in Male RatsALCOHOLISM, Issue 1 2009Peter Sykora Background:, Chronic ethanol feeding to male rats has been shown to result in decreased mitochondrial translation, depressed respiratory complex levels and mitochondrial respiration rates. In addition, ethanol consumption has been shown to result in an increased dissociation of mitoribosomes. S-adenosyl-L-methionine (SAM) is required for the assembly and subsequent stability of mitoribosomes and is depleted during chronic ethanol feeding. The ability of dietary SAM co-administration to prevent these ethanol-elicited lesions was investigated. Methods:, Male Sprague-Dawley rats were fed a nutritionally adequate liquid diet with ethanol comprising 36% of the calories according to a pair-fed design for 28 days. For some animals, SAM was supplemented in the diet at 200 mg/l. Liver mitochondria were prepared and mitoribosomes isolated. Respiration rates, ATP levels, respiratory complex levels, and the extent of mitoribosome dissociation were determined. Results:, Twenty-eight days of ethanol feeding were found to result in decreased SAM content, depressed respiration, and increased mitoribosome dissociation. No changes in mitochondrial protein content; levels of respiratory complexes I, III, and V; complex I activities; and ATP levels were detected. Co-administration of SAM in the diet was found to prevent ethanol-induced SAM depletion, respiration decreases and mitoribosome dissociation. Conclusions:, Taken together, these findings suggest (1) that mitoribosome dissociation precedes respiratory complex depressions in alcoholic animals and (2) that dietary supplementation of SAM prevents some of the early mitochondrial lesions associated with chronic ethanol consumption. [source] Dissociation of the ,001, Dislocations and Their Interactions with Dislocation Loops in Tetragonal BaTiO3JOURNAL OF THE AMERICAN CERAMIC SOCIETY, Issue 5 2006Shun-Yu Cheng Dislocations in pressureless-sintered BaTiO3 ceramics have been analyzed using transmission electron microscopy. Subjected to effective sintering stresses, dislocations were generated and multiplied in plastically deformed BaTiO3 crystals by the Frank,Read mechanism from both single- and double-ended sources. This is represented by dislocations encompassing a series of square-like borders that shared a common center. All border dislocations exhibited the characteristic scallop shape. True dislocation line directions (u) were determined by trace analysis and Burgers vectors (b) by contrast analysis for the dislocations dissociated from b=,001, into two half-partials following the type (I) reaction ofby climb on {001}. Dislocation interactions between the main dislocations created from plastic deformation and dislocation loops of b=,100, or ,110, forming condensation of intrinsic Schottky vacancies were also found to obey the type (IV) reaction of, the type (V) reactions of. Migrating dislocations and loops interacting mutually in several stages, illustrated schematically, before arriving at the configuration described by types (IV) and (V) were observed and discussed. [source] Dissociation: An insufficiently recognized major feature of complex posttraumatic stress disorderJOURNAL OF TRAUMATIC STRESS, Issue 5 2005Onno van der Hart The role of dissociation in (complex) posttraumatic stress disorder (PTSD) has been insufficiently recognized for at least two reasons: the view that dissociation is a peripheral, not a central feature of PTSD, and existing confusion regarding the nature of dissociation. In this conceptual article, the authors address both issues by postulating that traumatization essentially involves some degree of division or dissociation of psychobiological systems that constitute personality. One or more dissociative parts of the personality avoid traumatic memories and perform functions in daily life, while one or more other parts remain fixated in traumatic experiences and defensive actions. Dissociative parts manifest in negative and positive dissociative symptoms that should be distinguished from alterations of consciousness. Complex PTSD involves a more complex structural dissociation than simple PTSD. [source] Highly diffusion-sensitized MRI of brain: Dissociation of gray and white matterMAGNETIC RESONANCE IN MEDICINE, Issue 5 2001Takashi Yoshiura Abstract The brains of six healthy volunteers were scanned with a full tensor diffusion MRI technique to study the effect of a high b value on diffusion-weighted images (DWIs). The b values ranged from 500 to 5000 s/mm2. Isotropic DWIs, trace apparent diffusion coefficient (ADC) maps, and fractional anisotropy (FA) maps were created for each b value. As the b value increased, ADC decreased in both the gray and white matter. Furthermore, ADC of the white matter became lower than that of the gray matter, and, as a result, the white matter became brighter than the gray matter in the isotropic DWIs. Quantitative analysis showed that these changes were due to nonmonoexponential diffusion signal decay of the brain tissue, which was more prominent in white matter than in gray matter. There was no significant change in relation to the b value in the FA maps. High b value appears to have a dissociating effect on gray and white matter in DWIs. Magn Reson Med 45:734,740, 2001. © 2001 Wiley-Liss, Inc. [source] Dissociation between cutaneous silent period and laser evoked potentials in assessing neuropathic painMUSCLE AND NERVE, Issue 3 2009A. Truini MD Abstract In this study we investigate whether the cutaneous silent period (CSP),an inhibitory response evoked in hand muscles by painful digital nerve stimulation,is useful for assessing nociceptive pathway function in patients with neuropathic pain. In 40 patients with peripheral neuropathy (21 without and 19 with neuropathic pain) we recorded the CSP in the abductor digiti minimi after fifth digit stimulation and also recorded laser evoked potentials (LEPs) after stimulation applied to the ulnar territory of the hand. Although the LEP amplitude was significantly lower in patients with pain than in those without (P < 0.005), the CSP duration did not differ between groups (P > 0.50). Pain intensity correlated significantly with LEP amplitudes (P < 0.005) but not with CSP duration (P > 0.5). Our findings indicate that the CSP is not useful for assessing nociceptive pathway function in patients with neuropathic pain. Muscle Nerve, 2008 [source] Pseudotermination of Atrioventricular Nodal Reentrant Tachycardia Related to Isorhythmic Atrioventricular DissociationPACING AND CLINICAL ELECTROPHYSIOLOGY, Issue 12 2003MITSUNORI MARUYAMA Unusual manifestations of the mode of termination were observed in a patient with atrioventricular nodal reentrant tachycardia (AVNRT). After administration of verapamil during AVNRT, isorhythmic atrioventricular dissociation occurred without termination of the tachycardia. The sinus rate was slightly faster than that of the AVNRT, leading to the P wave preceding the QRS complex with a normal PR interval (e.g., pseudotermination). This phenomenon emphasizes the importance of continuous monitoring during an attempt to terminate AVNRT. (PACE 2003; 26:2338,2339) [source] | ||||||||||||||||||||||||||||||||||||||||||||||||||||