Effects of epinephrine on heart rate variability and cytokines in a rat sepsis model.

Catecholamines have both anti-inflammatory and vasoactive properties. A decreased cardiac response to catecholamines has been associated with a high risk of death in sepsis and septic shock. The aim of this study was to investigate the effects of epinephrine (EPI) on heart rate variability (HRV) and autonomic balance, as well as cytokine levels, in a rat sepsis model. Thirty-six male Sprague-Dawley rats were assigned to 4 experimental groups and 2 control groups of 6 rats each. The rats in the experimental groups were inoculated with a lipopolysaccharide (LPS, endotoxin) to establish a sepsis model. Group A received only LPS; group B received LPS, antecedent EPI and the nonselective ß-blocker propranolol; group C received LPS and antecedent EPI; and group D received LPS, antecedent EPI and the selective ß1-blocker esmolol. One control group received EPI and the other received saline placebo. Heart rate variability (HRV) was analyzed and tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6) and interleukin-1ß (IL-1ß) levels were measured. Measurements were carried out at baseline, at 0 hour after EPI infusion, and at 0.5, 2, and 4 hours after LPS inoculation. There were significant differences in HRV and cytokine levels between the groups, indicating that LPS infusion caused autonomic imbalance. Antecedent EPI significantly decreased the level of TNF-α in group C compared with group A in which TNF-α level peaked at 2 hours and then declined. Propranolol (group B) but not esmolol (group D) administration resulted in elevated TNF-α levels, comparable to those observed in group A. In conclusion, antecedent administration of EPI in a rat sepsis model inhibits the production of TNF-α possibly via the ß2-adrenoceptor.

Testing the Validity of a Cognitive Behavioral Model for Gambling Behavior.

Currently, cognitive behavioral therapies appear to be one of the most studied treatments for gambling problems and studies show it is effective in treating gambling problems. However, cognitive behavior models have not been widely tested using statistical means. Thus, the aim of this study was to test the validity of the pathways postulated in the cognitive behavioral theory of gambling behavior using structural equation modeling (AMOS 20). Several questionnaires assessing a range of gambling specific variables (e.g., gambling urges, cognitions and behaviors) and gambling correlates (e.g., psychological states, and coping styles) were distributed to 969 participants from the community. Results showed that negative psychological states (i.e., depression, anxiety and stress) only directly predicted gambling behavior, whereas gambling urges predicted gambling behavior directly as well as indirectly via gambling cognitions. Avoidance coping predicted gambling behavior only indirectly via gambling cognitions. Negative psychological states were significantly related to gambling cognitions as well as avoidance coping. In addition, significant gender differences were also found. The results provided confirmation for the validity of the pathways postulated in the cognitive behavioral theory of gambling behavior. It also highlighted the importance of gender differences in conceptualizing gambling behavior.

Gratitude, hope, mindfulness and personal-growth initiative: buffers or risk factors for problem gambling?

The majority of prevention and intervention research in problem gambling (PG) has focused on identifying negative risk factors. However, not all at-risk individuals go on to develop anticipated disorders and many thrive in spite of them. In healthcare settings, PG and other disorders are typically conceptualized from the biomedical perspective that frame disorders as something negative residing within the individual and reduction in negativity is seen as success. Indeed, this problem-focused conceptualization may be adequate in many cases as reducing PG behaviour is undoubtedly an important outcome, but the focus on negativity alone is too narrow to capture the complexity of human behaviour. Hence, this study attempts to bridge the gap in literature by providing an evaluation of the predictive ability of the positive dispositions on problem gambling severity, gambling-related cognitions, and gambling urges. The positive psychological dispositions examined were curiosity, gratitude, hope, personal growth initiative, and mindfulness. Participants consisted of 801 Taiwanese Chinese students and community individuals (Mean age = 25.36 years). Higher levels of gratitude and hope have been found to predict lower PG, gambling-related cognitions, or gambling urges. Meanwhile, higher mindfulness predicted lower PG, but only among Chinese males. However, lower personal growth initiative predicted lower PG, gambling-related cognitions, and gambling urges. These analyses have small to medium effect sizes with significant predictions. Findings of this study have essential implications in understanding and treating Chinese problem gamblers. These positive dispositions should be addressed by mental health professionals in preventative and treatment programs among Chinese individuals. Further implications and suggestions for future research are discussed.

The role of autonomic nervous system function in hypothermia-mediated sepsis protection.

OBJECTIVE: The objective of this study is to determine whether hypothermia will lessen decreases in heart rate variability and improve outcome in a rat model of sepsis. METHODS: Thirty-six male Sprague-Dawley rats were randomized into 3 groups: control, low sepsis, and high sepsis groups. These groups were each subdivided into a normothermia (37°C) (n = 6) and a hypothermia group (34°C) (n = 6). Cyclophosphamide (100 mg/kg) was administered 5 days before Staphylococcus aureus injection to produce conditions in which sepsis could be induced reliably. Hypothermic rats received temperature reduction for 1 hour post injection. Electrocardiogram was recorded before, after, and 1 day after staphylococcal injection, and the low frequency, high frequency (HF), and LF/HF ratio measurements of heart rate variability and the frequencies of arrhythmia were recorded. The effects of time, sepsis severity, and hypothermia on these variables were analyzed using a multivariate generalized estimation equation mode. RESULTS: Four deaths occurred in the normothermic group, and none, in the hypothermic group. Sepsis of both low and high severity increased low frequency and HF 1 day after sepsis induction. Hypothermia significantly decreased HF in low, but not high sepsis severity. CONCLUSIONS: Hypothermia decreased mortality in septic rats. The influence of hypothermia on HF depended on the severity of the sepsis.