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Multifactorial Process (multifactorial + process)

Distribution by Scientific Domains

Medical Sciences	71%

Selected Abstracts

Evaluation of Right Ventricular Fibrosis in Adult Congenital Heart Disease Using Gadolinium-enhanced Magnetic Resonance Imaging: Initial Experience in Patients with Right Ventricular Loading Conditions

CONGENITAL HEART DISEASE, Issue 5 2006
Lopa P. Hartke MD
ABSTRACT Objective., Gadolinium-enhanced cardiac magnetic resonance imaging has been used to show myocardial fibrosis, a finding that appears as late gadolinium enhancement. Its role in the evaluation of right ventricular fibrosis in congenital heart disease is unclear. The purpose of this study was to demonstrate late gadolinium enhancement of the right ventricle in adult and adolescent congenital heart disease and to investigate the relationship between this enhancement and clinical and pathophysiological data. Design., In total, 24 patients, 16 patients with congenital heart disease and right ventricular loading conditions and 8 controls, underwent gadolinium-enhanced viability imaging. Diagnoses varied and included repaired, palliated, and unrepaired lesions. The presence and extent of right ventricular late gadolinium enhancement was compared with patient clinical and hemodynamic data. Exact Wilcoxon tests, Fisher's exact tests, and Spearman's rank correlation were used to compare variables. Results., Nine of 16 patients (56%) were found to have right ventricular late gadolinium enhancement, ranging from 5% to 80% of right ventricular myocardium affected (mean 36.1%, SD 29.7). The combination of right ventricular systolic pressure ,98 mm Hg and systemic oxygen saturation ,93% strongly suggested the presence of right ventricular late gadolinium enhancement (positive predictive value 100%), but no single variable or combination of variables could reliably predict its absence (negative predictive values ,75%). Extent of right ventricular late gadolinium enhancement did not correlate with degree of either hypoxia or right ventricular hypertension. Conclusions., Gadolinium-enhanced cardiac magnetic resonance demonstrates right ventricular late gadolinium enhancement in some patients with congenital heart disease and right ventricular loading conditions. Clinical variables were associated with the presence of fibrosis but did not reliably predict severity. Myocardial preservation is likely a multifactorial process that may affect the right and left ventricles differently. [source]

Hyponatremia and Heart Failure,Treatment Considerations

CONGESTIVE HEART FAILURE, Issue 1 2006
Domenic A. Sica MD
Hyponatremia as it occurs in the heart failure patient is a multifactorial process. The presence of hyponatremia in the heart failure patient correlates with both the severity of the disease and its ultimate outcome. The therapeutic approach to the treatment of hyponatremia in heart failure has traditionally relied on attempts to improve cardiac function while at the same time limiting fluid intake. In more select circumstances, hypertonic saline, loop diuretics, and/or lithium or demeclocycline have been used. The latter two compounds act by retarding the antidiuretic effect of vasopressin but carry with their use the risk of serious renal and/or cardiovascular side effects. Alternatively, agents that selectively block the type 2 vasopressin receptor increase free water excretion without any of the adverse consequences of other therapies. Conivaptan, lixivaptan, and tolvaptan are three such aquaretic drugs. Vasopressin receptor antagonists will redefine the treatment of heart failure-related hyponatremia and may possibly evolve as adjunct therapies to loop diuretics in diuretic-resistant patients. [source]

Interleukin-6 Induction by Helicobacter pylori in Human Macrophages is Dependent on Phagocytosis

HELICOBACTER, Issue 3 2006
Stefan Odenbreit
Abstract Background:, The colonization of the gastric mucosa with Helicobacter pylori is accompanied by elevated levels of proinflammatory cytokines, such as interleukin-1 (IL-1), IL-6, and IL-8. The aim of our study was to determine the mechanisms of IL-6 stimulation in phagocytes upon H. pylori infection. Materials and Methods:, We investigated the secretion of IL-6 by different professional phagocytes from murine and human origin, including granulocyte- and monocyte-like cells and macrophages derived from human peripheral blood monocytes (PBMCs). The influence of viability, phagocytosis, and the impact of different subcellular fractions of H. pylori bacteria were evaluated. Results:, IL-6 levels induced by H. pylori were low in cell lines derived from murine and human monocytes and in human granulocyte-like cells. By contrast, macrophages derived from human PBMCs were highly responsive to both H. pylori and Escherichia coli. IL-6 induction was blocked by inhibition of actin-dependent processes prior to infection with H. pylori, but not with E. coli or E. coli lipopolysaccharide (LPS). Using cell fractionation, the most activity was found in the H. pylori membrane. H. pylori LPS exhibited a 103 - to 104 -fold lower biologic activity than E. coli LPS, suggesting a minor role for toll-like receptor 4 (TLR4)-mediated signalling from the exterior. Conclusions:, From these data, we conclude that macrophages may be a major source of IL-6 in the gastric mucosa upon H. pylori infection. The IL-6 induction by H. pylori in these cells is a multifactorial process, which requires the uptake and presumably degradation of H. pylori bacteria. [source]

Cardiovascular dialysis instability and convective therapies

HEMODIALYSIS INTERNATIONAL, Issue 2006
Antonio SANTORO
Abstract Acute hypotension is a frequent hemodialysis complication. Intratreatment vascular instability is a multifactorial process in which procedure-related and patient-related factors may influence the decrease in plasma volume and induce an impairment of cardiovascular regulatory mechanisms. Identification of the most susceptible patients and of the various risk factors may contribute to significantly improve cardiovascular stability during dialysis. In some high-risk patients, monitoring and biofeedback of the various hemodynamic variables, together with an extensive use of convection, can prevent the appearance of symptomatic hypotension and help in averting its onset. [source]

miR-17, miR-19b, miR-20a, and miR-106a are down-regulated in human aging

AGING CELL, Issue 2 2010
Matthias Hackl
Summary Aging is a multifactorial process where deterioration of body functions is driven by stochastic damage while counteracted by distinct genetically encoded repair systems. To better understand the genetic component of aging, many studies have addressed the gene and protein expression profiles of various aging model systems engaging different organisms from yeast to human. The recently identified small non-coding miRNAs are potent post-transcriptional regulators that can modify the expression of up to several hundred target genes per single miRNA, similar to transcription factors. Increasing evidence shows that miRNAs contribute to the regulation of most if not all important physiological processes, including aging. However, so far the contribution of miRNAs to age-related and senescence-related changes in gene expression remains elusive. To address this question, we have selected four replicative cell aging models including endothelial cells, replicated CD8+ T cells, renal proximal tubular epithelial cells, and skin fibroblasts. Further included were three organismal aging models including foreskin, mesenchymal stem cells, and CD8+ T cell populations from old and young donors. Using locked nucleic acid-based miRNA microarrays, we identified four commonly regulated miRNAs, miR-17 down-regulated in all seven; miR-19b and miR-20a, down-regulated in six models; and miR-106a down-regulated in five models. Decrease in these miRNAs correlated with increased transcript levels of some established target genes, especially the cdk inhibitor p21/CDKN1A. These results establish miRNAs as novel markers of cell aging in humans. [source]

Global,Local Interference is Related to Callosal Compromise in Alcoholism: A Behavior-DTI Association Study

ALCOHOLISM, Issue 3 2009
Eva M. Müller-Oehring
Background:, Visuospatial ability is a multifactorial process commonly impaired in chronic alcoholism. Identification of which features of visuospatial processing are affected and which are spared in alcoholism, however, has not been clearly determined. We used a global,local paradigm to assess component processes of visuospatial ability and MR diffusion tensor imaging (DTI) to examine whether alcoholism-related microstructural degradation of the corpus callosum contributes to disruption of selective lateralized visuospatial and attention processes. Methods:, A hierarchical letter paradigm was devised, where large global letters were composed of small local letters. The task required identification of target letters among distractors presented at global, local, both, or neither level. Attention was either selectively directed to global or local levels or divided between levels. Participants were 18 detoxified chronic alcoholics and 22 age-matched healthy controls. DTI provided quantitative assessment of the integrity of corpus callosal white matter microstructure. Results:, Alcoholics generally had longer reaction times than controls but obtained similar accuracy scores. Both groups processed local targets faster than global targets and showed interference from targets at the unattended level. Alcoholics exhibited moderate compromise in selectively attending to the global level when the global stimuli were composed of local targets. Such local interference was less with longer abstinence. Callosal microstructural integrity compromise predicted degree of interference from stimulus incongruency in the alcoholic group. This relationship was not observed for lateral or third ventricular volumes, which are measures of nonspecific cortical volume deficits. Conclusion:, Global,local feature perception was generally spared in abstinent chronic alcoholics, but impairments were observed when directing attention to global features and when global and local information interfered at stimulus or response levels. Furthermore, the interference-callosal integrity relationship in alcoholics indicates that compromised visuospatial functions include those requiring bilateral integration of information. [source]

Aberrant Control of Motoneuronal Excitability in Amyotrophic Lateral Sclerosis: Excitatory Glutamate,/,D -Serine vs.

CHEMISTRY & BIODIVERSITY, Issue 6 2010
-Aminobutanoic Acid (GABA), Inhibitory Glycine/
Abstract The mechanism underlying selective motoneuronal loss in amyotrophic lateral sclerosis (ALS) remains uncertain. The pathogenesis appears to be a complex and multifactorial process. Glutamate excitotoxicity to motoneuron is one of the most intensely investigated targets for the treatment of ALS, and excessive motoneuronal excitation by glutamate through ionotropic glutamate receptors has been mainly demonstrated. However, development of clinically effective drug targeting glutamate is sometimes difficult, because some aspects of glutamergic signals also could be beneficial, as the injured neurons attempt to recruit endogenous recovery. This review is focused on identifying other mechanisms of imbalanced excitation in ALS motoneurons including excitation-modulating D -serine and inhibitory glycine/GABA. Further, validation of these mechanisms might ultimately lead us to new therapeutic targets for ALS. [source]