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Stress Induction (stress + induction)

Distribution by Scientific Domains

Life Sciences	40%

Selected Abstracts

Stress and selective attention: The interplay of mood, cortisol levels, and emotional information processing

PSYCHOPHYSIOLOGY, Issue 6 2002
Mark A. Ellenbogen
The effects of a stressful challenge on the processing of emotional words were examined in college students. Stress induction was achieved using a competitive computer task, where the individual either repeatedly lost or won against a confederate. Mood, attention, and cortisol were recorded during the study. There were four findings: (1) Participants in the negative stressor condition were faster to shift attention away from negative words than positive or neutral words; (2) attentional shifts away from negative words were associated with stress-induced mood lowering; (3) participants in the negative stress condition with elevated scores on the Beck Depression Inventory were slow to disengage attention from all stimuli; and (4) elevated depression scores were associated with lower cortisol change from baseline during the experimental phase, and with higher cortisol levels during the recovery phase. These findings point to information-processing strategies as a means to regulate emotion, and to atypical features of cognitive and adrenocortical function that may serve as putative risk markers of depression. [source]

Arsenate and dimethylarsinic acid in drinking water did not affect DNA damage repair in urinary bladder transitional cells or micronuclei in bone marrow,

ENVIRONMENTAL AND MOLECULAR MUTAGENESIS, Issue 9 2009
Amy Wang
Abstract Arsenic is a human skin, lung, and urinary bladder carcinogen, and may act as a cocarcinogen in the skin and urinary bladder. Possible modes of action of arsenic carcinogenesis/cocarcinogenesis include oxidative stress induction and inhibition of DNA damage repair. We investigated the effects of arsenic in drinking water on DNA damage repair in urinary bladder transitional cells and on micronucleus formation in bone marrow. F344 rats were given 100 ppm arsenate [As(V)] or dimethylarsinic acid [DMA(V)] in drinking water for 1 week. The in vivo repair of cyclophosphamide (CP)-induced DNA damage resulting from a single oral gavage of CP, and the in vitro repair of hydrogen peroxide (H2O2)- or formaldehyde-induced DNA damage, resulting from adding H2O2 or formaldehyde into cell medium, were measured by the Comet assay. DMA(V) effects were not observed on either CP-induced DNA damage induction or on DNA repair. Neither DMA(V) nor As(V) increased the H2O2 - or formaldehyde-induced DNA damage, and neither inhibited the repair of H2O2 -induced DNA damage. Neither DMA(V) nor As(V) increased the micronucleus frequency, nor did they elevate micronucleus frequency resulting from CP treatment above the level observed by the treatment with CP alone. These results suggest that arsenic carcinogenesis/cocarcinogenesis in the urinary bladder may not be via DNA damage repair inhibition. To our knowledge this is the first report of arsenic effects on DNA damage repair in the urinary bladder. Environ. Mol. Mutagen. 2009. Published 2009 by Wiley-Liss, Inc. [source]

Alternative Drying Processes for the Industrial Preservation of Lactic Acid Starter Cultures

BIOTECHNOLOGY PROGRESS, Issue 2 2007
Chalat Santivarangkna
The preservation of lactic acid starter cultures by alternative drying processes has attracted increasing attention due to the high costs and energy consumption of freezing and freeze drying. This review thus aims to provide a survey regarding the state of knowledge of starter culture production at high levels of viability. The results from numerous studies on various drying processes and lactic acid bacteria are summarized. The alternative drying processes considered, such as spray drying, fluidized bed drying, and vacuum drying, are mainly of industrial interest. The features, advantages, and disadvantages of these drying processes are described. In conclusion, the important factors that need to be considered, standardized, or optimized to achieve high levels of viability include intrinsic tolerance of cultures, growth media and conditions, stress induction, cell harvesting conditions, protective agents, rehydration conditions, enumeration of cells, and storage conditions. [source]

Changes of QT dispersion in patients with coronary artery disease dependent on different methods of stress induction

CLINICAL CARDIOLOGY, Issue 3 2000
B. Hailer M.D.
Abstract Background: Episodes of stress-induced myocardial ischemia in patients with coronary artery disease (CAD) may cause increases of QT dispersion (QTd). Hypothesis: Aim of this study was to analyze the effect of increasing heart rates on QTd and to compare the effect of different methods of stress induction in patients with varying degrees of CAD when estimating QTd. Methods: We studied 58 patients, 22 with prior myocardial infarction (MI), 25 without MI or wall motion disturbances at rest, and 11 patients without evidence of CAD. Prior to coronary angiography, standard 12-lead ECGs were obtained at rest as well as during dynamic exercise and pharmacologic stress using arbutamine simultaneously with echocardiography. QTd was determined at each stress level by subtracting minimal from maximal QT interval duration. Results: QTd values at rest were not consistently higher in the patients with CAD. At maximal heart rate, QTd was statistically significantly higher in patients with CAD with a better discrimination between groups for pharmacologic stress (p < 0.005 for exercise, p < 0.0001 for arbutamine). Patients after MI had higher QTd values under all conditions than did the groups without MI. As in patients with CAD, the values of this group changed more radically as a result of pharmacologic stress. Conclusion: Patients with CAD can be identified on the basis of QTd under stress. These changes were not as marked in patients with MI as their rest values were already increased. Overall, drug-induced stress produced greater differences than dynamic exercise, suggesting that the ischemic threshold might be lower in the former. [source]