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Potential Components (potential + component)

Distribution by Scientific Domains

Medical Sciences	50%

Selected Abstracts

Overproduction of reactive oxygen species in end-stage renal disease patients: A potential component of hemodialysis-associated inflammation

HEMODIALYSIS INTERNATIONAL, Issue 1 2005
Marion Morena
Abstract During the past decade, hemodialysis (HD)-induced inflammation has been linked to the development of long-term morbidity in end-stage renal disease (ESRD) patients on regular renal replacement therapy. Because interleukins and anaphylatoxins produced during HD sessions are potent activators for nicotinamide adenine dinucleotide phosphate (NADPH) oxidase, an example of an enzyme that is responsible for overproduction of reactive oxygen species (ROS), this may constitute a link between leukocyte activation and cell or organ toxicity. Oxidative stress, which results from an imbalance between oxidant production and antioxidant defense mechanisms, has been documented in ESRD patients using lipid and/or protein oxidative markers. Characterization of HD-induced oxidative stress has included identification of potential activators for NADPH oxidase. Uremia per se could prime phagocyte oxidative burst. HD, far from improving the oxidative status, results in an enhancement of ROS owing to hemoincompatibility of the dialysis system, hemoreactivity of the membrane, and trace amounts of endotoxins in the dialysate. In addition, the HD process is associated with an impairment in antioxidant mechanisms. The resulting oxidative stress has been implicated in long-term complications including anemia, amyloidosis, accelerated atherosclerosis, and malnutrition. Prevention of oxidative stress in HD might focus on improving the hemocompatibility of the dialysis system, supplementation of deficient patients with antioxidants, and modulation of NADPH oxidase by pharmacologic approaches. [source]

Immunisation with non-integral OMPs promotes pulmonary clearance of Pseudomonas aeruginosa

FEMS IMMUNOLOGY & MEDICAL MICROBIOLOGY, Issue 2-3 2003
Linda D. Thomas
Abstract Pseudomonas aeruginosa is an opportunistic bacterial pathogen that can cause fatal acute lung infections in critically ill individuals. Lung damage due to chronic infections in cystic fibrosis sufferers is the major cause of morbidity and mortality in this group. The bacterium produces various immunomodulatory products that enable it to survive in the lung. Innate and increasing resistance to antibiotic therapy shown by this organism heightens the need for development of a vaccine. This study reports the identification of six non-integral protein antigens; Pa 13, azurin, acyl carrier protein (ACP), amidase, aminopeptidase and KatE, purified from a mucoid strain of P. aeruginosa. N-terminal amino acid sequencing was used to identify these proteins and, based on their ascribed functions, determined that their normal cellular location was cytosolic. A rat model of acute pulmonary infection was used to investigate the ability of these protein antigens to enhance pulmonary clearance of a live P. aeruginosa challenge. Mucosal immunisation with four of the six antigens significantly enhanced bacterial clearance from both the lavage fluid and lung tissue. The greatest level of clearance was demonstrated for the antigens; KatE, aminopeptidase and amidase. Enhanced bacterial clearance was maintained when the antigens amidase and aminopeptidase were produced in recombinant form. When delivered parenterally, aminopeptidase demonstrated its continued efficacy as a vaccine candidate. This study has demonstrated that non-integral outer membrane proteins are antigenic and protective and warrant further investigation as potential components of a vaccine. [source]

A practical determination strategy of optimal threshold parameter for matrix compression in wavelet BEM

INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN ENGINEERING, Issue 2 2003
Kazuhiro Koro
Abstract A practical strategy is developed to determine the optimal threshold parameter for wavelet-based boundary element (BE) analysis. The optimal parameter is determined so that the amount of storage (and computational work) is minimized without reducing the accuracy of the BE solution. In the present study, the Beylkin-type truncation scheme is used in the matrix assembly. To avoid unnecessary integration concerning the truncated entries of a coefficient matrix, a priori estimation of the matrix entries is introduced and thus the truncated entries are determined twice: before and after matrix assembly. The optimal threshold parameter is set based on the equilibrium of the truncation and discretization errors. These errors are estimated in the residual sense. For Laplace problems the discretization error is, in particular, indicated with the potential's contribution ,c, to the residual norm ,R, used in error estimation for mesh adaptation. Since the normalized residual norm ,c,/,u, (u: the potential components of BE solution) cannot be computed without main BE analysis, the discretization error is estimated by the approximate expression constructed through subsidiary BE calculation with smaller degree of freedom (DOF). The matrix compression using the proposed optimal threshold parameter enables us to generate a sparse matrix with O(N1+,) (0,,<1) non-zero entries. Although the quasi-optimal memory requirements and complexity are not attained, the compression rate of a few per cent can be achieved for N,1000. Copyright © 2003 John Wiley & Sons, Ltd. [source]

Water relations and gas exchange in poplar and willow under water stress and elevated atmospheric CO2

PHYSIOLOGIA PLANTARUM, Issue 1 2002
Jon D. Johnson
Predictions of shifts in rainfall patterns as atmospheric [CO2] increases could impact the growth of fast growing trees such as Populus spp. and Salix spp. and the interaction between elevated CO2 and water stress in these species is unknown. The objectives of this study were to characterize the responses to elevated CO2 and water stress in these two species, and to determine if elevated CO2 mitigated drought stress effects. Gas exchange, water potential components, whole plant transpiration and growth response to soil drying and recovery were assessed in hybrid poplar (clone 53,246) and willow (Salix sagitta) rooted cuttings growing in either ambient (350 µmol mol,1) or elevated (700 µmol mol,1) atmospheric CO2 concentration ([CO2]). Predawn water potential decreased with increasing water stress while midday water potentials remained unchanged (isohydric response). Turgor potentials at both predawn and midday increased in elevated [CO2], indicative of osmotic adjustment. Gas exchange was reduced by water stress while elevated [CO2] increased photosynthetic rates, reduced leaf conductance and nearly doubled instantaneous transpiration efficiency in both species. Dark respiration decreased in elevated [CO2] and water stress reduced Rd in the trees growing in ambient [CO2]. Willow had 56% lower whole plant hydraulic conductivity than poplar, and showed a 14% increase in elevated [CO2] while poplar was unresponsive. The physiological responses exhibited by poplar and willow to elevated [CO2] and water stress, singly, suggest that these species respond like other tree species. The interaction of [CO2] and water stress suggests that elevated [CO2] did mitigate the effects of water stress in willow, but not in poplar. [source]

Countertransference to psychiatric patients in a clinical setting: Development of the Feeling Checklist,Japanese version

PSYCHIATRY AND CLINICAL NEUROSCIENCES, Issue 6 2006
FUJIKA KATSUKI rn
Abstract, Countertransference is an important dimension of the therapeutic alliance between care providers and patients. The Feeling Checklist (FC) is a self-report questionnaire for the assessment of countertransference by hospital staff toward patients. The FC was translated from English into Japanese and its factor structure, reliability, and validity in the Japanese version (FC-J) were examined. A total of 281 Japanese psychiatric nurses were tested with the FC-J. All nurses were primarily involved in provision of psychiatric care. Principal-component factor analysis with varimax rotation was performed to identify the potential components of the FC-J. In a factor analysis of the FC-J, seven factors were extracted. The five subscales that were determined and labeled included Reject, Distance, Helpfulness, Closeness, and Involvement, which collectively accounted for 56.0% of the variance. Cronbach's ,, a measure of internal consistency, for individual subscales was 0.833 for Reject, 0.763 for Distance, 0.768 for Helpfulness, 0.617 for Closeness, and 0.663 for Involvement. Notably, there was a significant correlation between the FC-J and the Nurse Attitude Scale (P < 0.0001). Moreover, one-way anova was performed with each FC-J subscale to examine differences among psychiatric diagnoses in the study sample. A significant difference was found for Involvement (P < 0.001), with the total score on Involvement being the highest in the personality disorder group. These results are considered to verify the reliability and validity of the FC-J as a scale to measure countertransference among Japanese care providers. The use of this scale allows individual care providers to recognize and be cognizant of their own countertransference objectively and thereby contributes to improve the relationship between patients and care providers. [source]

The application of subliminal priming in lie detection: Scenario for identification of members of a terrorist ring

PSYCHOPHYSIOLOGY, Issue 4 2009
Ming Lui
Abstract We studied a lie detection protocol immune to countermeasures. The 4 stimulus conditions were (1 and 2) supraliminal acquaintance name primed by subliminal acquaintance name (A-A) versus subliminal nonacquaintance name (N-A) and (3 and 4) supraliminal nonacquaintance name primed by subliminal acquaintance name (A-N) versus subliminal nonacquaintance name (N-N). In Experiment 1 and replication, principal components analysis-derived event-related potential components revealed significant differences between dishonestly answered supraliminal acquaintance conditions with differing primes (A-A vs. N-A). In Experiment 2 subjects were required to lie in A-N and N-N conditions, in contrast to Experiment 1, in which subjects lied in A-A and N-A conditions. No significant effects were found. In Experiment 3, the lying task was removed and no significant differences were found. We conclude that subliminal primes modulate ERPs in conditions with supraliminal acquaintance name when the task involves lying. [source]