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Direct Relation (direct + relation)
Selected AbstractsDifferences in Echocardiographic Assessment with Standard Doppler and Tissue Doppler Imaging of Left Ventricular Filling Pressure in Idiopathic and Ischemic Dilated CardiomyopathyECHOCARDIOGRAPHY, Issue 7 2008Pierluigi Costanzo M.D. Background: In idiopathic and ischemic dilated cardiomyopathy (DCM) there are differences in left atrial and ventricular relaxation. We assessed the hypothesis of an influence of these dissimilarities in assessing left ventricular filling pressure (LVFP) in these two DCMs by standard Doppler and tissue Doppler imaging. In particular, we focused on early transmitral flow to early diastolic motion velocity of mitral annulus ratio (E/Ea), useful to estimate normal or elevated LVFP. However, when found in intermediate range (8,15), its role is unclear. Methods and Results: We evaluated 26 patients with ischemic and 21 patients with idiopathic DCM. To validate the echocardiographic estimation of LVFP, a sample (12 patients) underwent LVFP assessment by catheterization. In idiopathic DCM, E/Ea directly related to duration of retrograde pulmonary venous flow (ARd) (r = 0.66 P = 0001). In ischemic DCM E/Ea inversely related only to systolic to diastolic velocity ratio of pulmonary venous flow (S/D) (r =,0.56 P = 0002). After a mean follow up of 6 months, by a second echocardiogram we observed a direct relation between E/Ea and ARd percentage variation (r = 0.52 P = 0.02) in idiopathic DCM group, whereas in the ischemic DCM group there was an inverse relation between E/Ea and S/D percentage variation (r =,0.59 P = 0.02).Conclusions: In conclusion, ARd in idiopathic and S/D in ischemic DCM might be used as specific additional information to estimate LVFP when E/Ea falls within intermediate range. [source] Sleep-Disordered Breathing and Chronic Opioid TherapyPAIN MEDICINE, Issue 4 2008Lynn R. Webster MD ABSTRACT Objective., To assess the relation between medications prescribed for chronic pain and sleep apnea. Design., An observational study of chronic pain patients on opioid therapy who received overnight polysomnographies. Generalized linear models determined whether a dose relation exists between methadone, nonmethadone opioids, and benzodiazepines and the indices measuring sleep apnea. Setting., A private clinic specializing in the treatment of chronic pain. Patients., Polysomnography was sought for all consecutive (392) patients on around-the-clock opioid therapy for at least 6 months with a stable dose for at least 4 weeks. Of these, 147 polysomnographies were completed (189 patients declined, 56 were directed to other sleep laboratories by insurance companies, and data were incomplete for seven patients). Available data were analyzed on 140 patients. Outcome Measures., The apnea,hypopnea index to assess overall severity of sleep apnea and the central apnea index to assess central sleep apnea. Results., The apnea,hypopnea index was abnormal (,5 per hour) in 75% of patients (39% had obstructive sleep apnea, 4% had sleep apnea of indeterminate type, 24% had central sleep apnea, and 8% had both central and obstructive sleep apnea); 25% had no sleep apnea. We found a direct relation between the apnea,hypopnea index and the daily dosage of methadone (P = 0.002) but not to other around-the-clock opioids. We found a direct relation between the central apnea index and the daily dosage of methadone (P = 0.008) and also with benzodiazepines (P = 0.004). Conclusions., Sleep-disordered breathing was common in chronic pain patients on opioids. The dose,response relation of sleep apnea to methadone and benzodiazepines calls for increased vigilance. [source] Magnon energy gap and the magnetically structural symmetry in a three-layer ferrimagnetic superlatticePHYSICA STATUS SOLIDI (B) BASIC SOLID STATE PHYSICS, Issue 8 2006Rong-ke Qiu Abstract The magnon energy band in a ferrimagnetic superlattice with three layers in a unit cell is studied by employing retarded Green's functions and the spin-wave method. Two modulated energy gaps ,,13 and ,,23 are evaluated systematically, which exist in the magnon energy band along the Kx -direction perpendicular to the plane of the superlattice. It is revealed that the energy gap ,,13 has a direct relation with the symmetry among the spin quantum numbers and the interlayer exchange couplings, while the energy gap ,,23 relates to the symmetry among these spin quantum numbers only. These symmetries differ from the symmetry of crystallographic point groups. We define the magnetically structural symmetry that is dominated mainly by the magnetic parameters. The absence of the energy gap at a certain condition means that the system has a high magnetically structural symmetry. The magnetically structural symmetry of the superlattice, which is an intrinsic property, strongly affects the magnon energy band structure and thus the magnetic behaviors of the system. Furthermore, two complete bandgaps are observed to extend through the Brillouin zone (referred to as "magnonic crystal") in this superlattice system. (© 2006 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Heat acclimation and cross-tolerance against anoxia in ArabidopsisPLANT CELL & ENVIRONMENT, Issue 7 2008VALERIA BANTI ABSTRACT Arabidopsis seedlings are highly sensitive to low oxygen and they die rapidly when exposed to anoxia. Tolerance to anoxia depends on the ability to efficiently use carbohydrates through the fermentative pathway, as highlighted by the lower tolerance displayed by a mutant devoid of alcohol dehydrogenase. Other mechanisms of tolerance are also possible and may include a role for heat-induced genes. In fact, heat shock proteins (HSPs) are induced by anoxia. This suggests that there may be a cross-adaptation mechanism between heat and anoxic stress, and in this work, we studied the acclimation of Arabidopsis seedlings both to low oxygen and heat. The results show that seedlings subjected to hypoxia or heat pretreatment survive anoxia much better. Interestingly, we also observed an increased anoxia tolerance in heat-treated alcohol dehydrogenase (adh) mutant plants. On the other hand, anoxic pretreatment does not confer tolerance to heat stress. The success of the induction of HSPs by anoxia is in direct relation to the amount of sucrose available, and this in turn relates to how well seedlings will survive under anoxia. HSP transcripts were also detected during seed development and germination, two hypoxia-prone processes, suggesting that hypoxia-induced HSP expression is physiologically relevant. [source] Brain electrical correlates of dimensional weighting: An ERP studyPSYCHOPHYSIOLOGY, Issue 2 2007Klaus Gramann Abstract In visual search, there is a reaction time (RT) cost for targets on a given trial if the previous target was defined in a different dimension. According to the "dimension-weighting" account (Müller, Heller, & Ziegler, 1995), limited attentional weight needs to be shifted to the new dimension, resulting in slower RTs. The present study aimed at identifying brain electrical correlates associated with the weight shift. Analyses of ERPs revealed several components to reflect dimension changes whether the task was to detect the target or to identify its defining dimension. N2 amplitudes were more negative whenever the dimension changed. The P3 exhibited latency differences that mirrored RTs in both tasks, but the amplitudes showed no direct relation to stimulus- or response-related processes. Finally, slow-wave amplitudes were enhanced for dimension changes. Taken together, the results provide support for relatively early, perceptual processes underlying dimension change costs. [source] Angiotensin receptors in the eyes of arterial hypertensive ratsACTA OPHTHALMOLOGICA, Issue 4 2010Anu Vaajanen Abstract. Purpose:, The aim of the present study was to determine whether the eye tissues of arterial hypertensive rats evince expression of angiotensin receptors (AT1 and AT2) as well as the novel Mas receptor, whose endogenous ligand is vasorelaxing Angiotensin (1,7) [Ang (1,7)]. Methods:, Enucleated eyes from spontaneously hypertensive rats (SHR) and double transgenic rats harbouring human renin and angiotensinogen genes (dTGR) and their normotensive controls were used. Half of the rats were pretreated orally with an Angiotensin II (Ang II) type 1 receptor blocker (ARB). The eyes were snap-frozen in isopentane at ,40° and stored at ,70° for subsequent reverse transcriptase polymerase chain reaction (RT-PCR) analysis or in vitro autoradiography. Results:, The mRNA expression of AT1a and AT 2 as well as the novel Mas receptor was detected in all rat groups, being markedly higher in the retina than in the ciliary body. dTGR had significantly more receptors than SHR, but no direct relation to blood pressure level was seen. According to the autoradiography, treatment with ARB blocked a part of AT1 receptors but had no clear effect on AT2 receptors. Conclusion:, The novel Mas receptor was found by RT-PCR in eye tissue for the first time. Its specific ligand, Ang (1,7), may be involved in the regulation of intraocular pressure , as recently demonstrated by us , and in the pathogenesis of retinal diseases as a counter-regulatory component for the vascular and proliferative actions of Ang II. The results suggest that the density of AT1 receptors in the eye is independent of the blood pressure level of the animal. [source] Cerebral white matter blood flow and arterial blood pressure in preterm infantsACTA PAEDIATRICA, Issue 10 2010Klaus Børch Abstract It is generally assumed that one reason why white matter injury is common in preterm infants is the relatively poor vascular supply. Aim:, To examine whether blood flow to the white matter is relatively more reduced at low blood pressure than is blood flow to the brain as a whole. Methods:, Thirteen normoxic preterm infants had blood flow imaging on 16 occasions with single-photon emission computed tomography (SPECT) using 99Tc labelled hexa-methylpropylenamide oxime (HMPAO) as the tracer. Gestational age was 26,32 weeks. Transcutaneous carbon dioxide was between 4.7 and 8.5 kPa and mean arterial blood pressure between 22 and 55 mmHg. Results:, There was no statistically significant direct relation between white matter blood flow percentage and any of the variables. Using non-linear regression, however, assuming a plateau over a certain blood pressure threshold and a positive slope below this threshold, the relation to white matter flow percentage was statistically significant (p = 0.02). The threshold was 29 mmHg (95% confidence limits 26,33). Conclusion:, Our analysis supports the concept of periventricular white matter as selectively vulnerable to ischaemia during episodes of low blood pressure. [source] Amphiphilic Organic Ion Pairs in Solution: A Theoretical StudyCHEMPHYSCHEM, Issue 10 2007Vincent Pradines Dr. Abstract The macroscopic manifestation of hydrophobic interactions for amphiphilic organic ion pairs (tetraalkylammonium,anion) has been shown experimentally by measuring their association constants and their affinity with the organic phase. Beyond a certain size, there is a direct relation between association constants and chain lengths in tetraalkylammonium ions. We propose to cast a bridge between these results and geometrical properties considered at the level of a single ion pair by means of quantum chemistry calculations performed on model systems: trimethylalkylammonium,pentyl sulfate instead of tetraalkylammonium,dodecyl sulfate. Two limiting cases are considered: head-to-head configurations, which yield an optimal electrostatic interaction between polar heads, and parallel configurations with a balance between electrostatic and hydrophobic interactions. All properties (geometries, complexation energies, and atomic charges) were obtained at the MP2 level of calculation, with water described by a continuum model (CPCM). Dispersion forces link hydrocarbon chains of tetraalkylammonium ions and pentyl sulfate, thus yielding (for the largest ion pairs) parallel configurations favored with respect to head-to-head geometries by solute,solvent electrostatic interactions. Given the small experimental association energies, we probe the accuracy limit of the MP2 and CPCM methods. However, clear trends are obtained as a function of chain length, which agree with the experimental observations. The calculated monotonic stabilization of ion pairs when the hydrocarbon chain increases in length is discussed in terms of electrostatic interactions (between ions and between ion pairs and water), dispersion forces, and cavitation energies. [source] Putting the pieces together: Maternal depression, maternal behavior, and toddler helplessnessINFANT MENTAL HEALTH JOURNAL, Issue 1 2003Sue A. Kelley This study assessed relations between maternal depression, maternal behavior, and helplessness in toddlers. Helplessness was assessed behaviorally in 25- and 32-month-old toddlers while the toddlers were engaged with an impossible task. Maternal behavior (warmth, negativity, control, intrusiveness) was assessed during a mother,child teaching task when toddlers were 18 and 25 months of age. Mothers who reported more depressive symptoms on the BDI had 32-month-old toddlers who displayed more affect-related helplessness. No direct relations were found between maternal diagnosis of depression and helplessness in toddlers. Few differences emerged in the behavior of depressed and nondepressed mothers while interacting with their toddlers, and few relations were found between maternal behavior alone and toddlers' helplessness. However, results suggest that maternal behavior moderates the relation between maternal depression (diagnosis, recency, and symptoms) and helplessness. ©2003 Michigan Association for Infant Mental Health. [source] Attachment models of the self and others: Relations with self-esteem, humanity-esteem, and parental treatmentPERSONAL RELATIONSHIPS, Issue 3 2004Michelle A. Luke The present research tested the extent to which perceptions of early childhood experiences with parents predicted general views of the self (i.e., self-esteem) and others (i.e., humanity-esteem), and whether attachment self- and other-models mediated these links. Two studies used a new measure of humanity-esteem (Luke & Maio, 2004) to achieve these ends. As expected, indices that tapped a positive model of the self in relationships were associated with high self-esteem and indices that tapped a positive model of others in relationships were associated with high humanity-esteem. Also, early attachment experiences with fathers and mothers predicted self-esteem and humanity-esteem, respectively, and these direct relations were mediated by the attachment models. The studies, therefore, provide direct evidence that attachment measures predict general favorability toward the self and others, while revealing novel differences in the roles of childhood experiences with fathers and mothers. No variables, it is held, have more far-reaching effects on personality development than a child's experiences within the family: for, starting during his first months in his relation with his mother figure, and extending through the years of childhood and adolescence in his relation to both parents, he builds up working models of how attachment figures are likely to behave towards him in any of a variety of situations; and on those models are based all his expectations, and therefore all his plans, for the rest of his life. Bowlby (1973; p. 369) [source] | |||||||||||||