Impaired chronotropic response to physical activities in heart failure patients.

PubMed

Shen, Hong; Zhao, Jianrong; Zhou, Xiaohong; Li, Jingbo; Wan, Qing; Huang, Jing; Li, Hui; Wu, Liqun; Yang, Shungang; Wang, Ping

2017-05-25

While exercise-based cardiac rehabilitation has a beneficial effect on heart failure hospitalization and mortality, it is limited by the presence of chronotropic incompetence (CI) in some patients. This study explored the feasibility of using wearable devices to assess impaired chronotropic response in heart failure patients. Forty patients with heart failure (left ventricular ejection fraction, LVEF: 44.6 ± 5.8; age: 54.4 ± 11.7) received ECG Holter and accelerometer to monitor heart rate (HR) and physical activities during symptom-limited treadmill exercise testing, 6-min hall walk (6MHW), and 24-h daily living. CI was defined as maximal HR during peak exercise testing failing to reach 70% of age-predicted maximal HR (APMHR, 220 - age). The correlation between HR and physical activities in Holter-accelerometer recording was analyzed. Of 40 enrolled patients, 26 were able to perform treadmill exercise testing. Based on exercise test reports, 13 (50%) of 26 patients did not achieve at least 70% of APMHR (CI patients). CI patients achieved a lower % APMHR (62.0 ± 6.3%) than non-CI patients who achieved 72.0 ± 1.2% of APMHR (P < 0.0001). When Holter-accelerometer recording was used to assess chronotropic response, the percent APMHR achieved during 6MHW and physical activities was significantly lower in CI patients than in non-CI patients. CI patients had a significantly shorter 6MHW distance and less physical activity intensity than non-CI patients. The study found impaired chronotropic response in 50% of heart failure patients who took treadmill exercise testing. The wearable Holter-accelerometer recording could help to identify impaired chronotropic response to physical activities in heart failure patients. ClinicalTrials.gov ID NCT02358603 . Registered 16 May 2014.

Chronotropic Incompetence and Risk of Atrial Fibrillation: The Henry Ford ExercIse Testing (FIT) Project.

PubMed

O'Neal, Wesley T; Qureshi, Waqas T; Blaha, Michael J; Dardari, Zeina A; Ehrman, Jonathan K; Brawner, Clinton A; Soliman, Elsayed Z; Al-Mallah, Mouaz H

2016-11-01

To examine the association between chronotropic incompetence and incident atrial fibrillation (AF). Patients with inadequate heart rate response during exercise may have abnormalities in sinus node function or autonomic tone that predispose to the development of AF. We examined the association between heart rate response and incident AF in 57,402 (mean age=54±13 years, 47% female, 64% white) patients free of baseline AF who underwent exercise-treadmill stress testing from the Henry Ford ExercIse Testing (FIT) Project. Age-predicted maximum heart rate (pMHR) values <85% and chronotropic index values <80% were used to define chronotropic incompetence. Cox regression, adjusting for demographics, cardiovascular risk factors, medications, coronary heart disease, heart failure, and metabolic equivalent of task achieved, was used to compute hazard ratios (HR) and 95% confidence intervals (CI) for the association between chronotropic incompetence and incident AF. Over a median follow-up of 5.0 years (25 th -75 th percentiles=2.6, 7.8), a total of 3,395 (5.9%) participants developed AF. pMHR values <85% were associated with an increased risk for AF development (HR=1.33, 95%CI=1.22, 1.44). Chronotropic index values <80% also were associated with an increased risk of AF (HR=1.28, 95%CI=1.19, 1.38). The associations of pMHR and chronotropic index with AF remained significant with varying cut-off points to define chronotropic incompetence. Our analysis suggests that patients with inadequate heart rate response during exercise have an increased risk for developing AF.

Enteral albuterol decreases the need for chronotropic agents in patients with cervical spinal cord injury-induced bradycardia.

PubMed

Evans, Charity H; Duby, Jeremiah J; Berry, Andrew J; Schermer, Carol R; Cocanour, Christine S

2014-02-01

Cervical spinal cord injury (CSCI) is often complicated by autonomic instability and life-threatening bradycardia. β-adrenergic receptors offer a potential target for modulating cardiac vagal activity and heart rate. Enteral albuterol may mitigate symptomatic bradycardia in CSCI patients. The purpose of this study was to examine the effect of enteral albuterol on the frequency of symptomatic bradycardia and the need for rescue therapy in CSCI patients. The charts of CSCI patients admitted to a Level I trauma center from February 2008 through March 2012 were reviewed for demographics, episodes of symptomatic bradycardia (defined as heart rate < 60 beats per minute and systolic blood pressure < 90 mm Hg), use of enteral albuterol, hospital days requiring chronotropic use, and total atropine administered. In the albuterol group, patients received scheduled enteral albuterol after experiencing symptomatic bradycardia, with chronotropic agents used as needed for rescue treatment. In the no-albuterol group, only chronotropic agents were used as needed for rescue treatment. The albuterol and no-albuterol groups were compared using independent-samples Kruskal-Wallis test for total number of bradycardic episodes, hospital days requiring chronotropic use, and total atropine administered. Eighteen patients with CSCI-induced bradycardia were identified. Eight patients received treatment with enteral albuterol, and 10 patients did not. The median age did not differ significantly between the two groups. However, the median Injury Severity Score (ISS) was higher in the albuterol group (median ISS, 36.5; interquartile range, 35-66.5 vs. median ISS 26; interquartile range, 27-37.25 in no-albuterol group). Patients receiving albuterol experienced 1.8 symptomatic bradycardic episodes versus 4.3 episodes in those patients not receiving albuterol (p = 0.08). Hospital days on chronotropic agents were significantly less in the albuterol group (1.8 vs. 8.6, p = 0.01). One patient, in the no-albuterol group, required pacemaker placement. Enteral albuterol may reduce the frequency of symptomatic bradycardia in patients with CSCI, resulting in less rescue therapy using chronotropic agents. Therapeutic study, level IV.

Distinct effects of CGRP on typical and atypical smooth muscle cells involved in generating spontaneous contractions in the mouse renal pelvis

PubMed Central

Hashitani, Hikaru; Lang, Richard J; Mitsui, Retsu; Mabuchi, Yoshio; Suzuki, Hikaru

2009-01-01

Background and purpose: We investigated the cellular mechanisms underlying spontaneous contractions in the mouse renal pelvis, regulated by calcitonin gene-related peptide (CGRP). Experimental approach: Spontaneous contractions, action potentials and Ca2+ transients in typical and atypical smooth muscle cells (TSMCs and ATSMCs) within the renal pelvis wall were recorded separately using tension and intracellular microelectrode recording techniques and Fluo-4 Ca2+ imaging. Immunohistochemical and electron microscopic studies were also carried out. Key results: Bundles of CGRP containing transient receptor potential cation channel, subfamily V, member 1-positive sensory nerves were situated near both TSMCs and ATSMCs. Nerve stimulation reduced the frequency but augmented the amplitude and duration of spontaneous phasic contractions, action potentials and Ca2+ transients in TSMCs. CGRP and agents increasing internal cyclic adenosine monophosphate (cAMP) mimicked the nerve-mediated modulation of TSMC activity and suppressed ATSMCs Ca2+ transients. Membrane hyperpolarization induced by CGRP or cAMP stimulators was blocked by glibenclamide, while their negative chronotropic effects were less affected. Glibenclamide enhanced TSMC Ca2+ transients but inhibited ATSMC Ca2+ transients, while both 5-hydroxydecanoate and diazoxide, a blocker and opener of mitochondrial ATP-sensitive K+ channels, respectively, reduced the Ca2+ transient frequency in both TSMCs and ATSMCs. Inhibition of mitochondrial function blocked ATSMCs Ca2+ transients and inhibited spontaneous excitation of TSMCs. Conclusions and implications: The negative chronotropic effects of CGRP result primarily from suppression of ATSMC Ca2+ transients rather than opening of plasmalemmal ATP-sensitive K+ channels in TSMCs. The positive inotropic effects of CGRP may derive from activation of TSMC L-type Ca2+ channels. Mitochondrial Ca2+ handling in ATSMCs also plays a critical role in generating Ca2+ transients. PMID:20050194

Update on the cardiovascular profile of fingolimod in the therapy of relapsing-remitting multiple sclerosis (MS).

PubMed

Meissner, Axel; Limmroth, Volker

2016-07-01

Fingolimod (FTY720) has been approved as the first oral representative of the class of sphingosine-1-phosphate (S1P) receptor modulators for the treatment of relapsing-remitting multiple sclerosis (MS). Besides inducing vaso-relaxation, fingolimod can also influence electrical conduction in the myocardium and vascular endothelium by having a transient negative chronotropic effect on the sinus node. Cardiac safety and tolerability of fingolimod in the cardiac sense were reviewed by analysing the data collected from the FREEDOMS and TRANSFORMS studies -both relevant studies for marketing authorisation, from their extension studies, as well as the clinical data collected from a practice-related MS patient cohort with cardiovascular risk factors and corresponding co-medication (FIRST study). The safety analyses on file gave no indication of any increased cardiovascular risk. The 2-3mmHg increase in blood pressure observed after the first dose of fingolimod has no therapeutic consequences. The first dose of 0.5mg fingolimod resulted in an average decrease in heart rate of 7-8beats/min. The onset of effect occurred approximately 1-2h after the first dose and the nadir was reached after approximately 4-5h. This negative chronotropic effect returned to normal after internalisation of the S1P1 receptors on maintenance therapy. There were no indications that patients with cardiac risk factors required closer observation beyond the monitoring recommended by the EMA following the first dose of fingolimod. Case study observations from the routine clinical setting show that patients accept this method of monitoring, which they assess as being a positive aspect of attentive medical care and concern. Copyright © 2016 Elsevier B.V. All rights reserved.

Methoxyflurane anesthesia augments the chronotropic and dromotropic effects of verapamil.

PubMed

Jamali, F; Mayo, P R

1999-01-01

Inhalation anesthetics have been shown to have electrical suppressant effects on excitable membranes such as the cardiac conduction system. Therefore, the anesthetized patient or laboratory animal may respond differently to cardiac drugs when compared with their conscious counterparts. The purpose of this study was to assess the effects of anesthesia with methoxyflurane (MF) on the dromotropic and chronotropic effects of verapamil (VER) in the rat. A lead I ECG was measured using subcutaneous electrodes placed both axilli and over the xyphoid process in male Sprague-Dawley rats. Dromotropic effect was measured using the PR-interval which indicated the electrical spread across the atria to the AV-node and chronotropic effects were determined using RR-interval. A total of six animals were randomized to receive 10 mg/kg s.c. of verapamil in the presence or absence of general anesthesia containing methoxyflurane. In addition, PR-interval and RR-intervals were determined in the presence of only methoxyflurane and at rest without any drug exposure. The time for the ECG to normalize after exposure to methoxyflurane and/or verapamil was also determined. Exposure to verapamil alone resulted in a 5% prolongation in PR-interval and 6% prolongation in RR-interval. Methoxyflurane alone had a larger effect than verapamil demonstrating a 14.5% prolongation in PR-interval and a 12.3% in RR-interval which was statistically significant. The combination of MF + VER resulted in a synergistic prolongation in PR-interval to 28. 7% while the effect on RR-interval was additive with an increase to 17.6%. The time for the ECG to normalize after exposure to VER, MF and VER + MF was 37.5 15.1 min, 69.8 5.3 min, and 148.5 +/- 6.6 min respectively. General anesthesia with MF enhances the dromotropic and chronotropic effect of VER. This should be considered when MF-anesthesia is used in experimental procedure.

Results From the First‐in‐Human Study With Ozanimod, a Novel, Selective Sphingosine‐1‐Phosphate Receptor Modulator

PubMed Central

Hartung, Jeffrey P.; Peach, Robert J.; Boehm, Marcus F.; Rosen, Hugh; Smith, Heather; Brooks, Jennifer L.; Timony, Gregg A.; Olson, Allan D.; Gujrathi, Sheila; Frohna, Paul A.

2017-01-01

Abstract The sphingosine‐1‐phosphate 1 receptor (S1P1R) is expressed by lymphocytes, dendritic cells, and vascular endothelial cells and plays a role in the regulation of chronic inflammation and lymphocyte egress from peripheral lymphoid organs. Ozanimod is an oral selective modulator of S1P1R and S1P5R receptors in clinical development for the treatment of chronic immune‐mediated, inflammatory diseases. This first‐in‐human study characterized the safety, pharmacokinetics (PK), and pharmacodynamics (PD) of ozanimod in 88 healthy volunteers using a range of single and multiple doses (7 and 28 days) and a dose‐escalation regimen. Ozanimod was generally well tolerated up to a maximum single dose of 3 mg and multiple doses of 2 mg/d, with no severe adverse events (AEs) and no dose‐limiting toxicities. The most common ozanimod‐related AEs included headache, somnolence, dizziness, nausea, and fatigue. Ozanimod exhibited linear PK, high steady‐state volume of distribution (73–101 L/kg), moderate oral clearance (204–227 L/h), and an elimination half‐life of approximately 17 to 21 hours. Ozanimod produced a robust dose‐dependent reduction in total peripheral lymphocytes, with a median decrease of 65% to 68% observed after 28 days of dosing at 1 and 1.5 mg/d, respectively. Ozanimod selectivity affected lymphocyte subtypes, causing marked decreases in cells expressing CCR7 and variable decreases in subsets lacking CCR7. A dose‐dependent negative chronotropic effect was observed following the first dose, with the dose‐escalation regimen attenuating the first‐dose negative chronotropic effect. Ozanimod safety, PK, and PD properties support the once‐daily regimens under clinical investigation. PMID:28398597

Effect of high-intensity training versus moderate training on peak oxygen uptake and chronotropic response in heart transplant recipients: a randomized crossover trial.

PubMed

Dall, C H; Snoer, M; Christensen, S; Monk-Hansen, T; Frederiksen, M; Gustafsson, F; Langberg, H; Prescott, E

2014-10-01

In heart transplant (HTx) recipients, there has been reluctance to recommend high-intensity interval training (HIIT) due to denervation and chronotropic impairment of the heart. We compared the effects of 12 weeks' HIIT versus continued moderate exercise (CON) on exercise capacity and chronotropic response in stable HTx recipients >12 months after transplantation in a randomized crossover trial. The study was completed by 16 HTx recipients (mean age 52 years, 75% males). Baseline peak oxygen uptake (VO2peak ) was 22.9 mL/kg/min. HIIT increased VO2peak by 4.9 ± 2.7 mL/min/kg (17%) and CON by 2.6 ± 2.2 mL/kg/min (10%) (significantly higher in HIIT; p < 0.001). During HIIT, systolic blood pressure decreased significantly (p = 0.037) with no significant change in CON (p = 0.241; between group difference p = 0.027). Peak heart rate (HRpeak ) increased significantly by 4.3 beats per minute (p = 0.014) after HIIT with no significant change in CON (p = 0.34; between group difference p = 0.027). Heart rate recovery (HRrecovery ) improved in both groups with a trend toward greater improvement after HIIT. The 5-month washout showed a significant loss of improvement. HIIT was well tolerated, had a superior effect on oxygen uptake, and led to an unexpected increase in HRpeak accompanied by a faster HRrecovery . This indicates that the benefits of HIIT are partly a result of improved chronotropic response. © Copyright 2014 The American Society of Transplantation and the American Society of Transplant Surgeons.

Correlation between chronotropic incompetence and metabolic equivalents in patients with type 2 diabetes mellitus and concomitant metabolic syndrome.

PubMed

Gao, M; Chen, W; Gong, Z K; Han, L; Zhang, L

2015-09-01

The aim of the study was to examine the relationship between chronotropic incompetence and motor ability in patient with type 2 diabetes mellitus and concomitant metabolic syndrome (MS) in order to facilitate exercise prescriptions for these patients. A total of 120 patients with type 2 diabetes mellitus were randomly enrolled and divided into study groups with (N.=64) or without MS (N.=56). All patients completed the electrocardiographic exercise testing, after which ratio of heart rate (rHR) and heart rate reserve (HRR) were calculating to assess chronotropic incompetence. In addition, maximum metabolic equivalents (maxMETs) were calculated to assess the motor ability. The MS group had significantly higher indicators of chronotropic incompetence (rHR and HRR) as well as maxMETs than patients without MS (all P<0.05). Further, maxMETs significantly correlated with rHR (r=0.81, P=0.003) and HRR (r=0.78, P<0.001). Patients with type 2 diabetes mellitus and concomitant MS have higher chronotropic incompetence and maxMETs compared with those without MS. METs or perceived level of exertion can be used in patients in whom heart rate is not available during the exercise.

Extraction and phytochemical investigation of Calotropis procera: effect of plant extracts on the activity of diverse muscles.

PubMed

Moustafa, A M Y; Ahmed, S H; Nabil, Z I; Hussein, A A; Omran, M A

2010-10-01

Calotropis procera (Ait.) R.Br. (Asclepiadaceae) is a shrub or small tree that grows wild in Egypt. Calotropis acts as a purgative, anthelmintic, anticoagulant, palliative (in problems with respiration, blood pressure), antipyretic, and analgesic, and induces neuromuscular blocking activity. Little research has been done to study the electrophysiological effects of this plant's extracts on cardiac, smooth, and skeletal muscle activities. The present study was conducted to determine the phytochemical composition and the effect of the total alcohol extract of the shoot of the plant, which contains almost all of C. procera's cardiac glycosides, flavonoids, and saponins. Also, this study attempted to throw more light on the electrophysiological effects of the plant extracts on cardiac, smooth, and skeletal muscle activities and to clarify the mechanism(s) of their observed action(s). The aerial parts of the plant were air dried and their ethanol extracts partitioned with successive solvents. Cardiac, smooth, and skeletal muscles were used in this study to investigate the physiological and pharmacological effects of the plant extracts from different solvents. The data were analyzed by paired t-test. The phytochemical investigation of Calotropis procera revealed the presence of cardenolides, flavonoids, and saponins. The effects of ethanol, n-butanol, and ethyl acetate (EtOAc) extracts were each evaluated on isolated toad heart and their mechanisms of action determined. Perfusion with 2 μg/mL ethanol, 0.2 μg/mL butanol, and 0.2 μg/mL EtOAc extracts caused a significant decrease in heart rate (bradycardia), significant increase in the force of ventricular contraction, and increase in T-wave amplitude. In addition, the effects of different extracts of the studied plant on smooth muscle and skeletal muscle were investigated in this study. The different extracts and latex of C. procera induced a negative chronotropic effect and decreased the heart rate (HR) of isolated toad heart. The different extracts increased the power of contraction of the duodenum (trace a). Pretreatment with atropine sulfate as a muscarinic receptor blocker abolished the stimulatory effect of the different plant extracts and latex of C. procera (trace b). The present data suggest that ethanol, butanol, and EtOAc extracts of Calotropis procera have negative chronotropism and positive inotropism. Verapamil could abolish the inotropic effect of ethanol as well as that of butanol and EtOAc extracts. Meanwhile, atropine did not abolish the observed negative chronotropic effect. The ethanol extract increased the power of contraction of rabbit duodenum, but atropine abolished this effect. It also decreased the skeletal muscle contraction; this effect could be through blocking of the nicotinic receptors. Butanol and EtOAc extract data for smooth and skeletal muscles are very close to those for the corresponding ethanol extract of the studied plant. The present data for C. procera indicate its direct action on the myocardium, its increase of smooth muscle motility, and its relaxation of skeletal muscle contraction. The chemical constituents could directly affect the cell membrane probably through receptors coupling to G proteins. They regulate the ion channel physiology as in the myocardium. The present data on the extracts of C. procera indicate a direct action on the myocardium, stimulatory effect on smooth muscle motility, and relaxant action on skeletal muscle contraction. Chemical constituents could directly affect the cell membrane probably through receptors coupling to G proteins. They regulate the ion channel physiology as in the myocardium.

Cardiovascular effects of Helichrysum ceres S Moore [Asteraceae] ethanolic leaf extract in some experimental animal paradigms.

PubMed

Musabayane, Cephas T; Kamadyaapa, Dave R; Gondwe, Mavuto; Moodley, Kogi; Ojewole, John A O

2008-01-01

The aim of this study was to examine some in vivo and in vitro cardiovascular effects of Helichrysum ceres leaf ethanolic extract (HCE) in experimental animal paradigms. The acute effects of HCE on blood pressure were studied in anaesthetised normotensive male Wistar rats challenged with intravenous hypotonic saline infusion after a 3.5-hour equilibration for four hours of one-hour control, 1.5-hour treatment and 1.5-hour recovery periods. HCE was added to the infusate during the treatment period. Sub-chronic hypotensive effects of HCE were examined in weanling Dahl saltsensitive (DSS) genetically hypertensive rats, which progressively develop hypertension with age, treated with HCE (80 mg/kg) every third consecutive day for seven weeks. Isolated atrial muscle strips, portal veins and descending thoracic aortic rings of healthy normotensive Wistar rats were used to investigate the vascular effects of HCE. Acute HCE administration caused a significant (p < 0.05) fall in blood pressure in the normotensive anaesthetised Wistar rats. DSS hypertensive rats treated with HCE displayed low arterial blood pressure and heart rate values from weeks five to seven. HCE produced concentrationdependent negative inotropic and chronotropic effects on rat isolated electrically driven left, and spontaneously beating right atrial muscle preparations, respectively. HCE also evoked concentration-dependent relaxation responses of endothelium-intact aortic rings and portal veins isolated from healthy normotensive Wistar rats. The vasorelaxant effects of HCE in intact aortic rings were significantly reduced, but not completely abolished by adding endothelial- derived factor (EDRF) inhibitor, L-NAME, suggesting that the vasorelaxant effect of the extract is mediated via EDRF-dependent and independent mechanisms. The results of the study suggest that the hypotensive action of HCE is elicited, in part, directly by decreasing myocardial contractile performance and total peripheral vascular resistance due to its negative inotropic and chronotropic effects on rat isolated atrial muscle strips; and vasorelaxant effects on isolated vascular smooth muscles. The observed cardiovascular effects of HCE partly support the basis for its use in the management of high blood pressure in folkloric medicine.

Cardiovascular effects of Helichrysum ceres S Moore [Asteraceae] ethanolic leaf extract in some experimental animal paradigms

PubMed Central

Musabayane, Cephas T; Kamadyaapa, Dave R; Gondwe, Mavuto; Moodley, Kogi; Ojewole, John AO

2008-01-01

Summary Summary The aim of this study was to examine some in vivo and in vitro cardiovascular effects of Helichrysum ceres leaf ethanolic extract (HCE) in experimental animal paradigms. The acute effects of HCE on blood pressure were studied in anaesthetised normotensive male Wistar rats challenged with intravenous hypotonic saline infusion after a 3.5-hour equilibration for four hours of one-hour control, 1.5-hour treatment and 1.5-hour recovery periods. HCE was added to the infusate during the treatment period. Sub-chronic hypotensive effects of HCE were examined in weanling Dahl salt-sensitive (DSS) genetically hypertensive rats, which progressively develop hypertension with age, treated with HCE (80 mg/kg) every third consecutive day for seven weeks. Isolated atrial muscle strips, portal veins and descending thoracic aortic rings of healthy normotensive Wistar rats were used to investigate the vascular effects of HCE. Acute HCE administration caused a significant (p < 0.05) fall in blood pressure in the normotensive anaesthetised Wistar rats. DSS hypertensive rats treated with HCE displayed low arterial blood pressure and heart rate values from weeks five to seven. HCE produced concentration-dependent negative inotropic and chronotropic effects on rat isolated electrically driven left, and spontaneously beating right atrial muscle preparations, respectively. HCE also evoked concentration-dependent relaxation responses of endothelium-intact aortic rings and portal veins isolated from healthy normotensive Wistar rats. The vasorelaxant effects of HCE in intact aortic rings were significantly reduced, but not completely abolished by adding endothelial-derived factor (EDRF) inhibitor, L-NAME, suggesting that the vasorelaxant effect of the extract is mediated via EDRF-dependent and independent mechanisms. The results of the study suggest that the hypotensive action of HCE is elicited, in part, directly by decreasing myocardial contractile performance and total peripheral vascular resistance due to its negative inotropic and chronotropic effects on rat isolated atrial muscle strips; and vasorelaxant effects on isolated vascular smooth muscles. The observed cardiovascular effects of HCE partly support the basis for its use in the management of high blood pressure in folkloric medicine. PMID:18997985

Hypotensive, vasorelaxant and cardiodepressant activities of the ethanol extract of Sideritis raeseri spp. raeseri Boiss & Heldr.

PubMed

Kitic, D; Brankovic, S; Radenkovic, M; Savikin, K; Zdunic, G; Kocic, B; Velickovic-Radovanovic, R

2012-10-01

Sideritis raeseri spp. raeseri Boiss & Heldr is a native plant from the Mediterranean region that is used due to its medicinal and culinary properties. The aim of this study was to evaluate the effects of ethanol extract of S. raeseri on the blood pressure, vascular and cardiac contractions. Arterial blood pressure was registered directly from the carotid artery in the anaesthetized rabbits. Aortic rings and the spontaneously beating atria were mounted in tissue bath. An intravenous injection of extract of S. raeseri (0.025-7.5 mg/kg) caused a dose dependent decrease of the arterial pressure and heart rate, with EC(50) value of 24.31±3.87 mg/kg and 88.14±7.51 mg/kg, respectively. In aortic preparations precontracted with KCl (80 mM), the extract of S. raeseri (0.005-1.5 mg/ml) elicited a vasodilatator action (EC(50) 0.11±0.008 mg/ml). In spontaneously beating rat atria, the extract of S. raeseri (0.005-1.5 mg/ml) produced decrease of chronotropic and inotropic activity (with EC(50) value of 0.63±0.03 mg/ml and 0.40±0.08 mg/ml). Administration of verapamil induced inhibition of force and rate of the atrial contraction. These results demonstrate that the ethanol extract of Sideritis raeseri spp. raeseri Boiss & Heldr can produce hypotension, vasodilatation, negative chronotropic and inotropic effects.

β-Adrenergic Inhibition Prevents Action Potential and Calcium Handling Changes during Regional Myocardial Ischemia

PubMed Central

Murphy, Shannon R.; Wang, Lianguo; Wang, Zhen; Domondon, Philip; Lang, Di; Habecker, Beth A.; Myles, Rachel C.; Ripplinger, Crystal M.

2017-01-01

β-adrenergic receptor (β-AR) blockers may be administered during acute myocardial infarction (MI), as they reduce energy demand through negative chronotropic and inotropic effects and prevent ischemia-induced arrhythmogenesis. However, the direct effects of β-AR blockers on ventricular electrophysiology and intracellular Ca2+ handling during ischemia remain unknown. Using optical mapping of transmembrane potential (with RH237) and sarcoplasmic reticulum (SR) Ca2+ (with the low-affinity indicator Fluo-5N AM), the effects of 15 min of regional ischemia were assessed in isolated rabbit hearts (n = 19). The impact of β-AR inhibition on isolated hearts was assessed by pre-treatment with 100 nM propranolol (Prop) prior to ischemia (n = 7). To control for chronotropy and inotropy, hearts were continuously paced at 3.3 Hz and contraction was inhibited with 20 μM blebbistatin. Untreated ischemic hearts displayed prototypical shortening of action potential duration (APD80) in the ischemic zone (IZ) compared to the non-ischemic zone (NI) at 10 and 15 min ischemia, whereas APD shortening was prevented with Prop. Untreated ischemic hearts also displayed significant changes in SR Ca2+ handling in the IZ, including prolongation of SR Ca2+ reuptake and SR Ca2+ alternans, which were prevented with Prop pre-treatment. At 5 min ischemia, Prop pre-treated hearts also showed larger SR Ca2+ release amplitude in the IZ compared to untreated hearts. These results suggest that even when controlling for chronotropic and inotropic effects, β-AR inhibition has a favorable effect during acute regional ischemia via direct effects on APD and Ca2+ handling. PMID:28894423

Bioenergetics in the pathogenesis, progression and treatment of cardiovascular disorders.

PubMed

Tanner, H A

1995-05-01

The aim of this manuscript is to review perturbations in bioenergetics that are redundant denominators in the diversity of factors mediating the pathogenesis and progression of coronary heart disease (CHD), congestive heart failure (CHF), hypertension and arrhythmias. This paper likewise assesses the pharmacodynamics of widely prescribed drugs that enhance cellular respiration, maintain positive inotropic, chronotropic, dromotropic cardiac effects, sustain myocardial biosynthesis, reverse the morbidity of heart disease, and assure low levels of toxicity commensurate with the agent's biocompatability. Conversely, it is essential to delineate the modality of xenobiotic drugs that inhibit energy transformations, enhance the pathogenesis of CHD, worsen survival in CHF, provoke arrhythmogenic effects, and induce serious side-effects. Documented evidence, derived from biochemical, physiological and pharmacological data sources, consistently links inhibited mitochondrial decarboxylation to aberrations in cholesterol metabolism, biosynthesis, and calcium balance. Underutilized citrates evolved from inhibited decarboxylation are degraded to acetyl CoA. The acetate is the source of steroid synthesis; its carbon atoms form the molecular basis for all endogenous cholesterol. Myocardial anoxia, a consequence of the atheromatous plaque, inhibits ATP production, impairs biosynthesis, induces negative cardiac inotropic and chronotropic effects, and enhances the pathogenesis of CHF. Inhibited decarboxylation is likewise a factor in the mobilization of in situ cardiac Ca2+, resulting in arrhythmias provoked by the cation's deficiency. The restoration of calcium homeostasis decreases peripheral vasotension, reducing hypertension. Parameters drawn from endocrinopathies and the new physiological dimension of microgravity are developed to illustrate the detrimental effect of inhibited bioenergetics on cardiac pathomorphism and cardiovascular dysfunction. In conclusion, anabolic agents, adjunctive to a productive life-style, can provide the rational basis for the prevention and treatment of cardiac diseases. Failure to understand mechanisms generating cardiovascular morbidity eventuates in ineffective and empirical treatment.

Chronotropic Incompetence and its Relation to Exercise Intolerance in Chronic Obstructive Pulmonary Disease.

PubMed

Liu, Hai-Jian; Guo, Jian; Zhao, Qin-Hua; Wang, Lan; Yang, Wen-Lan; He, Jing; Gong, Su-Gang; Liu, Jin-Ming

2017-03-01

To study the relationship between chronotropic incompetence (CI) and disease severity and to assess the effect of CI on exercise capacity in patients with chronic obstructive pulmonary disease (COPD). Arterial blood gas analysis, pulmonary function test and cardiopulmonary exercise testing were conducted in 60 patients with stable COPD and 45 healthy volunteers. CI was defined using the chronotropic response index (CRI = (peak heart rate-resting heart rate) / (220-age-resting heart rate). Based on CRI, patients with COPD were divided into the normal chronotropic group (n = 23) and CI group (n = 37). CI was present in 61.7% of the patients with COPD. Exercise capacity (peak oxygen uptake as percentage of predicted value, peak VO 2 %pred), peak heart rate and CRI were significantly lower in patients with COPD than in controls. However, resting heart rate was significantly higher than in controls. FEV 1 %pred and exercise capacity were significantly decreased in the CI group when compared with those in the normotropic group. There was significant association between CRI with FEV 1 %pred and peak VO 2 %pred. Multivariate regression analysis showed that CRI and FEV 1 %pred were independent predictors of exercise capacity in patients with COPD. A cutoff of 0.74 for the CRI showed a specificity of 94.1% in predicting patients with a peak VO 2 %pred < 60%. CRI was associated with disease severity in patients with COPD. CI may be an important parameter to reflect exercise capacity in patients with COPD. Copyright © 2017 Southern Society for Clinical Investigation. Published by Elsevier Inc. All rights reserved.

Results From the First-in-Human Study With Ozanimod, a Novel, Selective Sphingosine-1-Phosphate Receptor Modulator.

PubMed

Tran, Jonathan Q; Hartung, Jeffrey P; Peach, Robert J; Boehm, Marcus F; Rosen, Hugh; Smith, Heather; Brooks, Jennifer L; Timony, Gregg A; Olson, Allan D; Gujrathi, Sheila; Frohna, Paul A

2017-08-01

The sphingosine-1-phosphate 1 receptor (S1P 1R ) is expressed by lymphocytes, dendritic cells, and vascular endothelial cells and plays a role in the regulation of chronic inflammation and lymphocyte egress from peripheral lymphoid organs. Ozanimod is an oral selective modulator of S1P 1R and S1P 5R receptors in clinical development for the treatment of chronic immune-mediated, inflammatory diseases. This first-in-human study characterized the safety, pharmacokinetics (PK), and pharmacodynamics (PD) of ozanimod in 88 healthy volunteers using a range of single and multiple doses (7 and 28 days) and a dose-escalation regimen. Ozanimod was generally well tolerated up to a maximum single dose of 3 mg and multiple doses of 2 mg/d, with no severe adverse events (AEs) and no dose-limiting toxicities. The most common ozanimod-related AEs included headache, somnolence, dizziness, nausea, and fatigue. Ozanimod exhibited linear PK, high steady-state volume of distribution (73-101 L/kg), moderate oral clearance (204-227 L/h), and an elimination half-life of approximately 17 to 21 hours. Ozanimod produced a robust dose-dependent reduction in total peripheral lymphocytes, with a median decrease of 65% to 68% observed after 28 days of dosing at 1 and 1.5 mg/d, respectively. Ozanimod selectivity affected lymphocyte subtypes, causing marked decreases in cells expressing CCR7 and variable decreases in subsets lacking CCR7. A dose-dependent negative chronotropic effect was observed following the first dose, with the dose-escalation regimen attenuating the first-dose negative chronotropic effect. Ozanimod safety, PK, and PD properties support the once-daily regimens under clinical investigation. © 2017, The Authors. The Journal of Clinical Pharmacology published by Wiley Periodicals, Inc. on behalf of American College of Clinical Pharmacology.

Sweet Chestnut (Castanea sativa Mill.) Bark Extract: Cardiovascular Activity and Myocyte Protection against Oxidative Damage

PubMed Central

Chiarini, Alberto; Micucci, Matteo; Ioan, Pierfranco; Fimognari, Carmela; Gallina Toschi, Tullia; Comandini, Patrizia; Hrelia, Silvana

2013-01-01

This work was aimed at evaluating the cardioprotective effects of Castanea sativa Mill. (CSM) bark extract characterized in its phenolic composition by HPLC-DAD-MS analysis. The study was performed using primary cultures of neonatal rat cardiomyocytes to investigate the antioxidant and cytoprotective effects of CSM bark extract and isolated guinea pig left and right atria, left papillary muscle, and aorta to evaluate its direct effect on cholinergic and adrenergic response. In cultured cardiomyocytes the CSM bark extract reduced intracellular reactive oxygen species formation and improved cell viability following oxidative stress in dose-dependent manner. Moreover, the extract decreased the contraction induced by noradrenaline (1 μM) in guinea pig aortic strips and induced transient negative chronotropic and positive inotropic effects without involvement of cholinergic or adrenergic receptors in the guinea pig atria. Our results indicate that CSM bark extract exhibits antioxidant activity and might induce cardioprotective effect. PMID:23533692

Cardiovascular effects of Persea americana Mill (Lauraceae) (avocado) aqueous leaf extract in experimental animals.

PubMed

Ojewole, J A O; Kamadyaapa, D R; Gondwe, M M; Moodley, K; Musabayane, C T

2007-01-01

The cardiovascular effects of Persea americana Mill (Lauraceae) aqueous leaf extract (PAE) have been investigated in some experimental animal paradigms. The effects of PAE on myocardial contractile performance was evaluated on guinea pig isolated atrial muscle strips, while the vasodilatory effects of the plant extract were examined on isolated portal veins and thoracic aortic rings of healthy normal Wistar rats in vitro. The hypotensive (antihypertensive) effect of the plant extract was examined in healthy normotensive and hypertensive Dahl salt-sensitive rats in vivo. P americana aqueous leaf extract (25-800 mg/ml) produced concentration-dependent, significant (p < 0.05-0.001), negative inotropic and negative chronotropic effects on guinea pig isolated electrically driven left and spontaneously beating right atrial muscle preparations, respectively. Moreover, PAE reduced or abolished, in a concentration-dependent manner, the positive inotropic and chronotropic responses of guinea pig isolated atrial muscle strips induced by noradrenaline (NA, 10(-10)-10(-5) M), and calcium (Ca(2+), 5-40 mM). PAE (50-800 mg/ml) also significantly reduced (p < 0.05-0.001) or abolished, in a concentration-dependent manner, the rhythmic, spontaneous, myogenic contractions of portal veins isolated from healthy normal Wistar rats. Like acetylcholine (ACh, 10(-8)-10(-5) M), the plant extract (25- 800 mg/ml) produced concentration-related relaxations of isolated endothelium-containing thoracic aortic rings pre-contracted with noradrenaline. The vasorelaxant effects of PAE in the isolated, endothelium-intact aortic rings were markedly inhibited or annulled by N(G)-nitro-L-arginine methyl ester (L-NAME, 10(-5) M), a nitric oxide synthase inhibitor. Furthermore, PAE (25-400 mg/kg iv) caused dose-related, transient but significant reductions (p < 0.05-0.001) in the systemic arterial blood pressure and heart rates of the anaesthetised normotensive and hypertensive rats used. The results of this laboratory animal study indicate that PAE caused bradycardia, vasorelaxation and hypotension in the mammalian experimental models used. The vasorelaxant action of PAE was endothelium dependent, and was, therefore, possibly dependent on the synthesis and release of nitric oxide (NO). The vasorelaxant effects of PAE appeared to contribute significantly to the hypotensive (antihypertensive) effects of the plant extract. However, the findings of this study tend to suggest that P americana leaf could be used as a natural supplementary remedy in essential hypertension and certain cases of cardiac dysfunctions in some rural Africa communities.

Effects of nesfatin-1 on atrial contractility and thoracic aorta reactivity in male rats.

PubMed

Barutcigil, Ayşe; Tasatargil, Arda

2017-10-13

This study aimed to examine the effects of nesfatin-1 on thoracic aorta vasoreactivity and to investigate the inotropic and chronotropic effects of nesfatin-1 on the spontaneous contractions of the isolated rat atria. Isolated right atria and thoracic aorta were used in organ baths. The reactivity of the thoracic aorta was evaluated by potassium chloride (KCl), phenylephrine (Phe), acetylcholine (ACh), and sodium nitroprusside (SNP). The effects of nesfatin-1 on the spontaneous contractions of the rat atria were also examined. Nesfatin-1 (0.1-100 ng/ml) produced a concentration-dependent relaxation response in rat thoracic aorta. The relaxant responses to nesfatin-1 were inhibited by the removal of endothelium, NO synthase blocker N-nitro-L-arginine methyl ester (L-NAME, 10 -4  M), and soluble guanylate cyclase inhibitor 1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one (ODQ, 10 -5  M). Nesfatin-1 (10 ng/ml, 30 min) increased the relaxation responses to either ACh or SNP, and the contractile response to both Phe and KCl did not significantly change in the arteries that were incubated with nesfatin-1 compared with the controls. The thoracic aorta contractions induced by the stepwise addition of Ca 2+ to a high KCl solution with no Ca 2+ were not significantly changed by nesfatin-1. Under calcium-free conditions, the contractions of the thoracic aorta rings incubated with nesfatin-1 in response to Phe were not significantly lower than those of the rings from the control rats. Nesfatin-1 showed positive inotropic and chronotropic effects on rat atria. Nesfatin-1 significantly changed the vascular responsiveness in rat thoracic aorta and produced positive inotropic and chronotropic effects on rat atria.

β1 -Adrenoceptor, but not β2 -adrenoceptor, subtype regulates heart rate in type 2 diabetic rats in vivo.

PubMed

Cook, Rosalind F; Bussey, Carol T; Mellor, Kimberley M; Cragg, Patricia A; Lamberts, Regis R

2017-08-01

What is the central question of the study? The sympathetic system regulates heart rate via β-adrenoceptors; this is impaired during diabetes. However, the specific β-adrenoceptor subtype contributions in heart rate regulation in diabetes in vivo are unknown. What is the main finding and its importance? Telemetric recordings in conscious non-diabetic and type 2 diabetic rats demonstrated that the β 1 -adrenoceptor subtype, and not the β 2 -adrenoceptor, regulated the lower resting heart rate and increased β-adrenoceptor responsiveness in diabetes in vivo. This provides new physiological insight into the dysregulation of heart rate in type 2 diabetes, which is important for improving therapeutic strategies targeting the diabetic chronotropic incompetence. β-Adrenoceptor blockers are widely used to reduce heart rate, the strongest predictor of mortality in cardiac patients, but are less effective in diabetic patients. This study aimed to determine the specific contributions of β 1 - and β 2 -adrenoceptor subtypes to chronotropic responses in type 2 diabetes in vivo, which are currently unknown. Type 2 diabetic and non-diabetic rats were implanted with radiotelemeters to measure arterial blood pressure and derive heart rate in conscious conditions. Vascular access ports were implanted to inject isoprenaline (β 1 - and β 2 -adrenoceptor agonist, 0.1-300 μg kg -1 ) in the presence of atenolol (β 1 -adrenoceptor antagonist, 2000 μg kg -1 ) or nadolol (β 1 - and β 2 -adrenoceptor agonist, 4000 μg kg -1 ) to determine the chronotropic contributions of the β-adrenoceptor subtypes. Resting heart rate was reduced in diabetic rats (388 ± 62 versus 290 ± 37 beats min -1 non-diabetic versus diabetic, P < 0.05, mean ± SD), which remained after atenolol or nadolol administration. Overall β-adrenoceptor chronotropic responsiveness was increased in diabetic rats (change in heart rate at highest dose of isoprenaline: 135 ± 66 versus 205 ± 28 beats min -1 , non-diabetic versus diabetic, P < 0.05), a difference that diminished after β 1 -adrenoceptor blockade with atenolol (change in heart rate at highest dose of isoprenaline: 205 ± 37 versus 195 ± 22 beats min -1 , non-diabetic versus diabetic, P < 0.05). In conclusion, the β 1 -adrenoceptor is the main subtype to modulate chronotropic β-adrenoceptor responses in healthy and diabetic rats. This study provides new insights into the pathological basis of dysregulation of heart rate in type 2 diabetes, which could be important for improving the current therapeutic strategies targeting diabetic chronotropic incompetence. © 2017 The Authors. Experimental Physiology © 2017 The Physiological Society.

Fractalkine in human inflammatory cardiomyopathy.

PubMed

Escher, F; Vetter, R; Kühl, U; Westermann, D; Schultheiss, H-P; Tschöpe, C

2011-05-01

Cardiac inflammation is important for the prognosis of patients with inflammatory cardiomyopathy (CMi), but the mechanisms leading to it are not fully elucidated. To study the role of fractalkine (CX3CL1) in chemotactic and adhesive properties of peripheral blood mononuclear cells (PBMCs) in patients with CMi. Patients with enterovirus (EV)-positive CMi, patients with virus-negative CMi, patients with parvovirus B19 (B19) genomes with low intramyocardial inflammation and patients without cardiac inflammation and viral infection in the endomyocardial biopsy (EMB) were enrolled (n=10/group). The expression of CX3CL1 and monocyte chemoattractant protein (MCP-1) in EMBs was significantly increased in EV-positive and virus-negative patients with CMi in contrast to controls and B19-positive patients (EV+ vs controls: CX3CL1-area fraction (AF) % 0.078±0.012 vs 0.009±0.003 p<0.05; MCP-1-AF % 0.093±0.023 vs 0.011±0.009). The receptor (CX3CR1)-mediated chemotaxis was increased twofold in PBMCs in comparison with those of controls. The MCP-1 secretion was 3.1-fold higher in PBMCs from EV-positive patients compared with controls, and this elevation was further increased by CX3CL1 in EV-positive patients. No significant CX3CL1-mediated MCP-1 increase was seen in PBMCs from healthy controls. Moreover, spontaneously beating neonatal rat cardiomyocytes exposed to CX3CL1 exhibited an attenuated positive chronotropic response to β-adrenergic stimulation with isoproterenol. The cardiac and plasma CX3CL1/CX3CR1 system is upregulated in CMi and this affects the functional potential of PBMCs. Moreover, a direct cardiodepressive effect of CX3CL1 in cardiac tissue was demonstrated since neonatal cardiomyocytes exhibited an attenuated positive chronotropic response to β-adrenergic stimulation.

Structural and functional cardiac cholinergic deficits in adult neurturin knockout mice.

PubMed

Mabe, Abigail M; Hoover, Donald B

2009-04-01

Previous work provided indirect evidence that the neurotrophic factor neurturin (NRTN) is required for normal cholinergic innervation of the heart. This study used nrtn knockout (KO) and wild-type (WT) mice to determine the effect of nrtn deletion on cardiac cholinergic innervation and function in the adult heart. Immunohistochemistry, confocal microscopy, and quantitative image analysis were used to directly evaluate intrinsic cardiac neuronal development. Atrial acetylcholine (ACh) levels were determined as an indirect index of cholinergic innervation. Cholinergic function was evaluated by measuring negative chronotropic responses to right vagal nerve stimulation in anaesthetized mice and responses of isolated atria to muscarinic agonists. KO hearts contained only 35% the normal number of cholinergic neurons, and the residual cholinergic neurons were 15% smaller than in WT. Cholinergic nerve density at the sinoatrial node was reduced by 87% in KOs, but noradrenergic nerve density was unaffected. Atrial ACh levels were substantially lower in KO mice (0.013 +/- 0.004 vs. 0.050 +/- 0.011 pmol/microg protein; P < 0.02) as expected from cholinergic neuron and nerve fibre deficits. Maximum bradycardia evoked by vagal stimulation was reduced in KO mice (38 +/- 6% vs. 69 +/- 3% decrease at 20 Hz; P < 0.001), and chronotropic responses took longer to develop and fade. In contrast to these deficits, isolated atria from KO mice had normal post-junctional sensitivity to carbachol and bethanechol. These findings demonstrate that NRTN is essential for normal cardiac cholinergic innervation and cholinergic control of heart rate. The presence of residual cardiac cholinergic neurons and vagal bradycardia in KO mice suggests that additional neurotrophic factors may influence this system.

An integrated platform for simultaneous multi-well field potential recording and Fura-2-based calcium transient ratiometry in human induced pluripotent stem cell (hiPSC)-derived cardiomyocytes.

PubMed

Rast, Georg; Weber, Jürgen; Disch, Christoph; Schuck, Elmar; Ittrich, Carina; Guth, Brian D

2015-01-01

Human induced pluripotent stem cell-derived cardiomyocytes are available from various sources and they are being evaluated for safety testing. Several platforms are available offering different assay principles and read-out parameters: patch-clamp and field potential recording, imaging or photometry, impedance measurement, and recording of contractile force. Routine use will establish which assay principle and which parameters best serve the intended purpose. We introduce a combination of field potential recording and calcium ratiometry from spontaneously beating cardiomyocytes as a novel assay providing a complementary read-out parameter set. Field potential recording is performed using a commercial multi-well multi-electrode array platform. Calcium ratiometry is performed using a fiber optic illumination and silicon avalanche photodetectors. Data condensation and statistical analysis are designed to enable statistical inference of differences and equivalence with regard to a solvent control. Simultaneous recording of field potentials and calcium transients from spontaneously beating monolayers was done in a nine-well format. Calcium channel blockers (e.g. nifedipine) and a blocker of calcium store release (ryanodine) can be recognized and discriminated based on the calcium transient signal. An agonist of L-type calcium channels, FPL 64176, increased and prolonged the calcium transient, whereas BAY K 8644, another L-type calcium channel agonist, had no effect. Both FPL 64176 and various calcium channel antagonists have chronotropic effects, which can be discriminated from typical "chronotropic" compounds, like (±)isoprenaline (positive) and arecaidine propargyl ester (negative), based on their effects on the calcium transient. Despite technical limitations in temporal resolution and exact matching of composite calcium transient with the field potential of a subset of cells, the combined recording platform enables a refined interpretation of the field potential recording and a more reliable identification of drug effects on calcium handling. Copyright © 2015 Elsevier Inc. All rights reserved.

[Effects of flunarizine and vitamin C on hemodynamics in rat heart subjected to ischemia-reperfusion].

PubMed

Xian, Y; Lan, T; Wang, Y

1998-09-01

Langendorff perfusion isolated rat heart was subjected to total global ischemia (coronary flow rate is equal to zero) for 10 minutes and reperfusion for 15 minutes. The heart rate (HR), left ventricular developed pressure (LVDP), coronary flow rate (CFR), electrocardiogram (ECG) and the effects of calcium antagonist-flunarizine (FNZ) and/or oxygen free radical scavenger--vitamine C on the above parameters were observed. The results showed that FNZ dilated coronary vessel (P < 0.01) and had a slight negative chronotropic effect, but it had no effect on LVP. Vitamine C did not affect HR, LVP and CFR. The recovery of the product of HR and LVDP-Rate Pressure Product (RPP) in the FNZ + Vit. C group, Vit. C group and FNZ group was significantly higher than that in the control group (P < 0.05) at ten minutes reperfusion. All the results suggest that FNZ and Vit. C may improve the recovery of heart function after reperfusion.

Aqueous extract from leaf of Artocarpus altilis provides cardio-protection from isoproterenol induced myocardial damage in rats: Negative chronotropic and inotropic effects.

PubMed

Nwokocha, Chukwuemeka; Palacios, Javier; Simirgiotis, Mario J; Thomas, Jemesha; Nwokocha, Magdalene; Young, Lauriann; Thompson, Rory; Cifuentes, Fredi; Paredes, Adrian; Delgoda, Rupika

2017-05-05

The leaves of Artocarpus altilis (Parkinson ex F.A.Zorn, Fosberg) (Moraceae) are used in the management of hypertension; this study assessed the cardio-protective effects of the leaf extract on isoproterenol (ISO) induced myocardial damage in rats. Twenty (20) adult male Sprague-Dawley rats (175-230g) were divided into 5 groups. Group 1 (Control), 2 (AA) received 50mg/Kg Artocarpus altilis (AA) only; 3 (ISO) received 85mg/Kg ISO only; 4 (ISO+AA/50) and 5 (ISO+AA/100) received 50 and 100mg/Kg AA respectively for 6 days, after induced with ISO twice (85mg/Kg) at a 24-h period. Blood pressure readings were taken before and after the administering of ISO using the tail cuff method. ECG was performed on anaesthetized rats. Cardiac contractility was measured in isolated right atrial muscles. Assessment of myocardial infarct (MI) size, heart/body weight ratio, biochemical, hematological and histo-morphological parameters were conducted at the end of seven days. An aqueous extract from leaves of A. altilis was analyzed for organic compounds using UHPLC mass spectrometry. ISO induced myocardial damage through an elevation of the heart rate (HR), infarct size and ECG distortions. Treatment with AA significantly (p˂0.05) reduced heart/body weight ratio (49%), MI (96%), HR (27%), sympathovagal imbalance (36%) and serum cardiac biomarkers (AST, LDH, HDL, triglycerides and CCK) caused by ISO. AA decreased the beat frequency of isolated right atrium (11%) cause by ISO, an action similar to propranolol (beta-adrenergic antagonist; 20%), but showed no significant changes in the QTc intervals of the ECG (suggesting no cardio-toxic drug-herb interactions), Thirty nine compounds were detected using high resolution LC-MS analysis (HPLC-Orbitrap-APCI-MS) in the extract. Pure compounds, as gallic acid and rutin, presented a higher negative chronotropic effect, similar to propranolol. Oral administration of aqueous extract of Artocarpus artilis has cardio-protective functions in myocardial injury, in part, by decreasing the HR, reduced contractility and infarct size. These findings may explain the cardio-protective use of A. altilis in traditional medicine. Copyright © 2017 Elsevier Ireland Ltd. All rights reserved.

ICI D7114 a novel selective beta-adrenoceptor agonist selectively stimulates brown fat and increases whole-body oxygen consumption.

PubMed Central

Holloway, B. R.; Howe, R.; Rao, B. S.; Stribling, D.; Mayers, R. M.; Briscoe, M. G.; Jackson, J. M.

1991-01-01

1. ICI D7114 is a novel, beta-adrenoceptor agonist which stimulates whole body oxygen consumption in conscious rats, cats and dogs and brown adipose tissue (BAT) activity in conscious rats. Treatment of rats with ICI D7114 stimulated oxygen consumption (ED50, 0.04 mg kg-1, p.o.) and BAT mitochondrial guanosine diphosphate (GDP)-binding (ED50, 0.15 mg kg-1, p.o.) with no chronotropic effects on the heart at these doses. 2. Reference beta-adrenoceptor agonists, isoprenaline and clenbuterol, also stimulated oxygen consumption and BAT activity but were less selective because they also produced effects on heart rate at these doses. 3. Treatment of conscious rats with ICI D7114 did not attenuate the chronotropic effects on the heart of a subsequent isoprenaline challenge. 4. Administration of ICI D7114 or of its acid metabolite had no effect in a cat soleus muscle model of tremor or on blood potassium levels in the conscious dog, indicating lack of effects at beta 2-adrenoceptors. 5. The results indicate that ICI D7114 may have activity at atypical beta-adrenoceptors in brown adipose tissue leading to increased whole body oxygen consumption. PMID:1686210

Functional β2-adrenoceptors in rat left atria: effect of foot-shock stress.

PubMed

Moura, André Luiz de; Hyslop, Stephen; Grassi-Kassisse, Dora M; Spadari, Regina C

2017-09-01

Altered sensitivity to the chronotropic effect of catecholamines and a reduction in the β 1 /β 2 -adrenoceptor ratio have previously been reported in right atria of stressed rats, human failing heart, and aging. In this report, we investigated whether left atrial inotropism was affected by foot-shock stress. Male rats were submitted to 3 foot-shock sessions and the left atrial inotropic response, adenylyl cyclase activity, and β-adrenoceptor expression were investigated. Left atria of stressed rats were supersensitive to isoprenaline when compared with control rats and this effect was abolished by ICI118,551, a selective β 2 -receptor antagonist. Schild plot slopes for the antagonism between CGP20712A (a selective β 1 -receptor antagonist) and isoprenaline differed from unity in atria of stressed but not control rats. Atrial sensitivity to norepinephrine, as well as basal and forskolin- or isoprenaline-stimulated adenylyl cyclase activities were not altered by stress. The effect of isoprenaline on adenylyl cyclase stimulation was partially blocked by ICI118,551 in atrial membranes of stressed rats. These findings indicate that foot-shock stress equally affects inotropism and chronotropism and that β 2 -adrenoceptor upregulation contributes to the enhanced inotropic response to isoprenaline.

Ayurvedic preparation of Zingiber officinale Roscoe: effects on cardiac and on smooth muscle parameters.

PubMed

Leoni, Alberto; Budriesi, Roberta; Poli, Ferruccio; Lianza, Mariacaterina; Graziadio, Alessandra; Venturini, Alice; Broccoli, Massimiliano; Micucci, Matteo

2017-08-28

The rhizome of the Zingiber officinale Roscoe, a biennial herb growing in South Asia, is commonly known as ginger. Ginger is used in clinical disorders, such as constipation, dyspepsia, diarrhoea, nausea and vomiting and its use is also recommended by the traditional medicine for cardiopathy, high blood pressure, palpitations and as a vasodilator to improve the circulation. The decoction of ginger rhizome is widely used in Ayurvedic medicine. In this papery by high-performance liquid chromatography, we have seen that its main phytomarkers were 6-gingerol, 8-gingerol and 6-shogaol and we report the effects of the decoction of ginger rhizome on cardiovascular parameters and on vascular and intestinal smooth muscle. In our experimental models, the decoction of ginger shows weak negative inotropic and chronotropic intrinsic activities but a significant intrinsic activity on smooth muscle with a potency on ileum is greater than on aorta: EC 50  = 0.66 mg/mL versus EC 50  = 1.45 mg/mL.

Cardiovascular and adenylate cyclase stimulating effects of colforsin daropate, a water-soluble forskolin derivative, compared with those of isoproterenol, dopamine and dobutamine.

PubMed

Yoneyama, Masahiko; Sugiyama, Atsushi; Satoh, Yoshioki; Takahara, Akira; Nakamura, Yuji; Hashimoto, Keitaro

2002-12-01

Colforsin daropate is a recently developed water-soluble derivative of forskolin that directly stimulates adenylate cyclase, unlike the catecholamines. The chronotropic, inotropic and coronary vasodilator actions of colforsin daropate were compared with those of isoproterenol, dopamine and dobutamine, using canine isolated, blood-perfused heart preparations. The stimulating effect of each drug on adenylate cyclase activity was also assessed. Colforsin daropate, as well as each of the catecholamines, exerted positive chronotropic, inotropic and coronary vasodilator actions. The order of selectivity for the cardiovascular variables of colforsin daropate was coronary vasodilation > positive inotropy > positive chronotropy; whereas that of isoproterenol, dopamine and dobutamine was positive inotropy > coronary vasodilation > positive chronotropy. Thus, a marked characteristic of colforsin daropate is its potent coronary vasodilator action. On the other hand, each drug significantly increased the adenylate cyclase activity in a dose-related manner: colforsin daropate > isoproterenol > dopamine = dobutamine. These results suggest that colforsin daropate may be preferable in the treatment of severe heart failure where the coronary blood flow is reduced and beta-adrenoceptor-dependent signal transduction pathway is down-regulated.

Cardiac autonomic impairment and chronotropic incompetence in fibromyalgia.

PubMed

da Cunha Ribeiro, Roberta Potenza; Roschel, Hamilton; Artioli, Guilherme Gianini; Dassouki, Thalita; Perandini, Luiz Augusto; Calich, Ana Luisa; de Sá Pinto, Ana Lúcia; Lima, Fernanda Rodrigues; Bonfá, Eloísa; Gualano, Bruno

2011-01-01

We aimed to gather knowledge on the cardiac autonomic modulation in patients with fibromyalgia (FM) in response to exercise and to investigate whether this population suffers from chronotropic incompetence (CI). Fourteen women with FM (age: 46 ± 3 years; body mass index (BMI): 26.6 ± 1.4 kg/m2) and 14 gender-, BMI- (25.4 ± 1.3 kg/m2), and age-matched (age: 41 ± 4 years) healthy individuals (CTRL) took part in this cross-sectional study. A treadmill cardiorespiratory test was performed and heart-rate (HR) response during exercise was evaluated by the chronotropic reserve. HR recovery (deltaHRR) was defined as the difference between HR at peak exercise and at both first (deltaHRR1) and second (deltaHRR2) minutes after the exercise test. FM patients presented lower maximal oxygen consumption (VO2 max) when compared with healthy subjects (22 ± 1 versus CTRL: 32 ± 2 mL/kg/minute, respectively; P < 0.001). Additionally, FM patients presented lower chronotropic reserve (72.5 ± 5 versus CTRL: 106.1 ± 6, P < 0.001), deltaHRR1 (24.5 ± 3 versus CTRL: 32.6 ± 2, P = 0.059) and deltaHRR2 (34.3 ± 4 versus CTRL: 50.8 ± 3, P = 0.002) than their healthy peers. The prevalence of CI was 57.1% among patients with FM. Patients with FM who undertook a graded exercise test may present CI and delayed HR recovery, both being indicative of cardiac autonomic impairment and higher risk of cardiovascular events and mortality.

Cardiac effects of 3-iodothyronamine: a new aminergic system modulating cardiac function.

PubMed

Chiellini, Grazia; Frascarelli, Sabina; Ghelardoni, Sandra; Carnicelli, Vittoria; Tobias, Sandra C; DeBarber, Andrea; Brogioni, Simona; Ronca-Testoni, Simonetta; Cerbai, Elisabetta; Grandy, David K; Scanlan, Thomas S; Zucchi, Riccardo

2007-05-01

3-Iodothyronamine T1AM is a novel endogenous thyroid hormone derivative that activates the G protein-coupled receptor known as trace anime-associated receptor 1 (TAAR1). In the isolated working rat heart and in rat cardiomyocytes, T1AM produced a reversible, dose-dependent negative inotropic effect (e.g., 27+/-5, 51+/-3, and 65+/-2% decrease in cardiac output at 19, 25, and 38 microM concentration, respectively). An independent negative chronotropic effect was also observed. The hemodynamic effects of T1AM were remarkably increased in the presence of the tyrosine kinase inhibitor genistein, whereas they were attenuated in the presence of the tyrosine phosphatase inhibitor vanadate. No effect was produced by inhibitors of protein kinase A, protein kinase C, calcium-calmodulin kinase II, phosphatidylinositol-3-kinase, or MAP kinases. Tissue cAMP levels were unchanged. In rat ventricular tissue, Western blot experiments with antiphosphotyrosine antibodies showed reduced phosphorylation of microsomal and cytosolic proteins after perfusion with synthetic T1AM; reverse transcriptase-polymerase chain reaction experiments revealed the presence of transcripts for at least 5 TAAR subtypes; specific and saturable binding of [125I]T1AM was observed, with a dissociation constant in the low micromolar range (5 microM); and endogenous T1AM was detectable by tandem mass spectrometry. In conclusion, our findings provide evidence for the existence of a novel aminergic system modulating cardiac function.

Abnormal heart rate recovery and deficient chronotropic response after submaximal exercise in young Marfan syndrome patients.

PubMed

Peres, Paulo; Carvalho, Antônio C; Perez, Ana Beatriz A; Medeiros, Wladimir M

2016-10-01

Marfan syndrome patients present important cardiac structural changes, ventricular dysfunction, and electrocardiographic changes. An abnormal heart rate response during or after exercise is an independent predictor of mortality and autonomic dysfunction. The aim of the present study was to compare heart rate recovery and chronotropic response obtained by cardiac reserve in patients with Marfan syndrome subjected to submaximal exercise. A total of 12 patients on β-blocker therapy and 13 off β-blocker therapy were compared with 12 healthy controls. They were subjected to submaximal exercise with lactate measurements. The heart rate recovery was obtained in the first minute of recovery and corrected for cardiac reserve and peak lactate concentration. Peak heart rate (141±16 versus 155±17 versus 174±8 bpm; p=0.001), heart rate reserve (58.7±9.4 versus 67.6±14.3 versus 82.6±4.8 bpm; p=0.001), heart rate recovery (22±6 versus 22±8 versus 34±9 bpm; p=0.001), and heart rate recovery/lactate (3±1 versus 3±1 versus 5±1 bpm/mmol/L; p=0.003) were different between Marfan groups and controls, respectively. All the patients with Marfan syndrome had heart rate recovery values below the mean observed in the control group. The absolute values of heart rate recovery were strongly correlated with the heart rate reserve (r=0.76; p=0.001). Marfan syndrome patients have reduced heart rate recovery and chronotropic deficit after submaximal exercise, and the chronotropic deficit is a strong determinant of heart rate recovery. These changes are suggestive of autonomic dysfunction.

Dose-dependent heart rate reducing effect of nizatidine, a histamine H2-receptor antagonist.

PubMed Central

Hinrichsen, H; Halabi, A; Fuhrmann, G; Kirch, W

1993-01-01

1. Twelve healthy subjects were treated in a randomised placebo-controlled crossover study with placebo, 150 mg, 300 mg, and 600 mg nizatidine, 100 mg pirenzepine, and 300 mg nizatidine plus 100 mg pirenzepine for 1 week each. 2. On the seventh treatment day, heart rate, blood pressure, systolic time intervals, impedance cardiographic and Doppler ultrasound variables were measured. 3. Stroke volume and blood pressure were not altered by nizatidine and/or pirenzepine. By contrast, heart rate and cardiac output significantly (P < 0.05) decreased in a dose-dependent manner 1.5 and 3 h after administration of 300 and 600 mg nizatidine. Treatment with 150 mg nizatidine led to similar though non-significant trends. 4. While a slightly insignificant rise in heart rate was detected with pirenzepine alone, heart rate and cardiac output remained unchanged upon combined nizatidine and pirenzepine treatment as compared with placebo and baseline values. 5. In conclusion, nizatidine reduced heart rate and cardiac output in a dose-dependent manner, whereas this negative chronotropic effect was counteracted by concurrent administration of the anti-cholinergic drug pirenzepine. PMID:8099802

Myocardial Infarction Injury in Patients with Chronic Lung Disease Entering Pulmonary Rehabilitation: Frequency and Association with Heart Rate Parameters.

PubMed

Sima, Carmen A; Lau, Benny C; Taylor, Carolyn M; van Eeden, Stephan F; Reid, W Darlene; Sheel, Andrew W; Kirkham, Ashley R; Camp, Pat G

2018-03-14

Myocardial infarction (MI) remains under-recognized in chronic lung disease (CLD) patients. Rehabilitation health professionals need accessible clinical measurements to identify the presence of prior MI in order to determine appropriate training prescription. To estimate prior MI in CLD patients entering a pulmonary rehabilitation program, as well as its association with heart rate parameters such as resting heart rate and chronotropic response index. Retrospective cohort design. Pulmonary rehabilitation outpatient clinic in a tertiary care university-affiliated hospital. Eighty-five CLD patients were studied. Electrocardiograms at rest and peak cardiopulmonary exercise testing, performed before pulmonary rehabilitation, were analyzed. Electrocardiographic evidence of prior MI, quantified by the Cardiac Infarction Injury Score (CIIS), was contrasted with reported myocardial events and then correlated with resting heart rate and chronotropic response index parameters. CIIS, resting heart rate, and chronotropic response index. Sixteen CLD patients (19%) demonstrated electrocardiographic evidence of prior MI, but less than half (8%) had a reported MI history (P < .05). The Cohen's kappa test revealed poor level of agreement between CIIS and medical records (kappa = 0.165), indicating that prior MI diagnosis was under-reported in the medical records. Simple and multiple regression analyses showed that resting heart rate but not chronotropic response index was positively associated with CIIS in our population (R 2 = 0.29, P < .001). CLD patients with a resting heart rate higher than 80 beats/min had approximately 5 times higher odds of having prior MI, as evidenced by a CIIS ≥20. CLD patients entering pulmonary rehabilitation are at risk of unreported prior MI. Elevated resting heart rate seems to be an indicator of prior MI in CLD patients; therefore, careful adjustment of training intensity such as intermittent training is recommended under these circumstances. III. Copyright © 2018 American Academy of Physical Medicine and Rehabilitation. Published by Elsevier Inc. All rights reserved.

A novel 'splice site' HCN4 Gene mutation, c.1737+1 G>T, causes familial bradycardia, reduced heart rate response, impaired chronotropic competence and increased short-term heart rate variability.

PubMed

Hategan, Lidia; Csányi, Beáta; Ördög, Balázs; Kákonyi, Kornél; Tringer, Annamária; Kiss, Orsolya; Orosz, Andrea; Sághy, László; Nagy, István; Hegedűs, Zoltán; Rudas, László; Széll, Márta; Varró, András; Forster, Tamás; Sepp, Róbert

2017-08-15

The most important molecular determinant of heart rate regulation in sino-atrial pacemaker cells includes hyperpolarization-activated, cyclic nucleotide-gated ion channels, the major isoform of which is encoded by the HCN4 gene. Mutations affecting the HCN4 gene are associated primarily with sick sinus syndrome. A novel c.1737+1 G>T 'splice-site' HCN4 mutation was identified in a large family with familial bradycardia which co-segregated with the disease providing a two-point LOD score of 4.87. Twelve out of the 22 investigated family members [4 males, 8 females average age 36 (SD 6) years] were considered as clinically affected (heart rate<60/min on resting ECG). Minimum [36 (SD 7) vs. 47 (SD 5) bpm, p=0.0087) and average heart rates [62 (SD 8) vs. 73 (SD 8) bpm, p=0.0168) were significantly lower in carriers on 24-hour Holter recordings. Under maximum exercise test carriers achieved significantly lower heart rates than non-carrier family members, and percent heart rate reserve and percent corrected heart rate reserve were significantly lower in carriers. Applying rigorous criteria for chronotropic incompetence a higher number of carriers exhibited chronotropic incompetence. Parameters, characterizing short-term variability of heart rate (i.e. rMSSD and pNN50%) were increased in carrier family members, even after normalization for heart rate, in the 24-hour ECG recordings with the same relative increase in 5-minute recordings. The identified novel 'splice site' HCN4 gene mutation, c.1737+1 G>T, causes familial bradycardia and leads to reduced heart rate response, impaired chronotropic competence and increased short-term heart rate variability in the mutation carriers. Copyright © 2017 Elsevier B.V. All rights reserved.

Characterization of the effects of neurokinins on canine antral muscle

DOE Office of Scientific and Technical Information (OSTI.GOV)

Koelbel, C.B.; Mayer, E.A.; Van Deventer, G.

1988-12-01

The excitation of longitudinal antral muscle by substance P (SP) involves both a myogenic and a cholinergic effect. To examine if these responses are mediated by different neurokinin receptors, the authors studied the mechanical response and the release of ({sup 3}H)acetylcholine from antral muscle strips in response to SP, substance P methylester (SPME), neurokinin A (NKA), neurokinin B (NKB), and several nonmammalian tachykinins. All peptides studied showed a dose-dependent inotropic and chronotropic effect on spontaneous phasic contractions. This ionotropic effect in longitudinal muscle was partially atropine sensitive for SPME, SP, and NKB but not for NKA, whereas neither atropine normore » tetrodotoxin had an effect in circular muscle. In longitudinal muscle, all three neurokinins were equipotent. In longitudinal muscle treated with atropine and in circular muscle, the rank order of potency for the inotropic response was NKA > NKB > SP > SPME. For the chronotropic response the rank order was SPME, SP > NKA > NKB. NKA, NKB, and SP caused a dose-dependent, tetrodotoxin-sensitive increase in ({sup 3}H)acetylcholine release from strips preincubated with ({sup 3}H)choline. NKA was significantly more potent to release ({sup 3}H)acetylcholine than either NKB or SP. The stimulated release was inhibited by (D-Ala{sup 2},D-Met{sup 5})methionine enkephalinamide and the SP antagonist, spantide. These results are consistent with the hypothesis that NKA is the natural ligand mediating the myogenic inotropic response in both muscle layers and the cholinergic response in longitudinal muscle.« less

Acute effect of Vagus nerve stimulation parameters on cardiac chronotropic, inotropic, and dromotropic responses

NASA Astrophysics Data System (ADS)

Ojeda, David; Le Rolle, Virginie; Romero-Ugalde, Hector M.; Gallet, Clément; Bonnet, Jean-Luc; Henry, Christine; Bel, Alain; Mabo, Philippe; Carrault, Guy; Hernández, Alfredo I.

2017-11-01

Vagus nerve stimulation (VNS) is an established therapy for drug-resistant epilepsy and depression, and is considered as a potential therapy for other pathologies, including Heart Failure (HF) or inflammatory diseases. In the case of HF, several experimental studies on animals have shown an improvement in the cardiac function and a reverse remodeling of the cardiac cavity when VNS is applied. However, recent clinical trials have not been able to reproduce the same response in humans. One of the hypothesis to explain this lack of response is related to the way in which stimulation parameters are defined. The combined effect of VNS parameters is still poorly-known, especially in the case of VNS synchronously delivered with cardiac activity. In this paper, we propose a methodology to analyze the acute cardiovascular effects of VNS parameters individually, as well as their interactive effects. A Latin hypercube sampling method was applied to design a uniform experimental plan. Data gathered from this experimental plan was used to produce a Gaussian process regression (GPR) model in order to estimate unobserved VNS sequences. Finally, a Morris screening sensitivity analysis method was applied to each obtained GPR model. Results highlight dominant effects of pulse current, pulse width and number of pulses over frequency and delay and, more importantly, the degree of interactions between these parameters on the most important acute cardiovascular responses. In particular, high interacting effects between current and pulse width were found. Similar sensitivity profiles were observed for chronotropic, dromotropic and inotropic effects. These findings are of primary importance for the future development of closed-loop, personalized neuromodulator technologies.

Interactions between acetylcholine, 5-hydroxytryptamine, nicotine and morphine on isolated rabbit atria

PubMed Central

Chittal, S. M.; Dadkar, N. K.; Gaitondé, B. B.

1968-01-01

1. The effects of 5-hydroxytryptamine (5-HT) and morphine on the responses to acetylcholine and nicotine of isolated rabbit atria were studied. 2. 5-Hydroxytryptamine (10 μg/ml.) and morphine (20 μg/ml.) blocked the negative chronotropic and inotropic actions of acetylcholine. 3. Nicotine (20 μg/ml.) produced stimulation of the atria, which was blocked by dichlorisoprenaline, morphine, 5-HT, bretylium and hemicholinium. Hemicholinium block was reversed by choline. 4. In reserpinized preparations, nicotine produced inhibition of atria and this action was also blocked by atropine, 5-HT and morphine. Inhibition induced by nicotine was potentiated by physostigmine. 5. 5-Hydroxytryptamine (20 μg/ml.) produced stimulation of atria. This was blocked by bretylium and reduced by hemicholinium. Hemicholinium block was reversed by choline. 6. It is concluded that 5-HT in low concentrations acts as a weak agonist at the cholinoceptive receptors and therefore blocks the action of acetylcholine. Furthermore, nicotine and larger doses of 5-HT have actions on ganglionic structures and liberate acetylcholine, which in turn releases catecholamines. PMID:4386371

Myotropic Effects of Cholinergic Muscarinic Agonists and Antagonists in the Beetle Tenebrio molitor L.

PubMed

Chowanski, Szymon; Rosinski, Grzegorz

2017-01-01

In mammals, the cholinergic nervous system plays a crucial role in neuronal regulation of physiological processes. It acts on cells by two types of receptors - nicotinic and muscarinic receptors. Both signal transmission pathways also operate in the central and peripheral cholinergic nervous system of insects. In our pharmacological experiments, we studied the effects of two muscarinic agonists (carbachol, pilocarpine) and two muscarinic antagonists (atropine, scopolamine) on the muscle contractile activity of visceral organs in the beetle, Tenebrio molitor. Both antagonists, when injected to haemolymph at concentration 10-5 M, caused delayed and prolonged cardioinhibitory effects on heart contractility in ortho- and antidromic phases of heart activity in T. molitor pupa what was observed as negative chrono- and inotropic effects. Agonist of muscarinic receptors - carbachol evoked opposite effect and increased contraction rate but only in antidromic phase. Pilocarpine, the second agonist induced weak negative chronotropic effects in the antiand orthodromic phases of heart activity. However, neither agonists had an effect on semi-isolated beetle heart in vitro. Only atropine at the highest tested concentrations slightly decreased the frequency of myocardial contractions. These suggest the regulation of heart activity by muscarinic system indirectly. The tested compounds also affected the contractility of the oviduct and hindgut, but the responses of these organs were varied and depended on the concentration of the applied compounds. These pharmacological experiments suggest the possible modulation of insect visceral muscle contractility by the cholinergic nervous system and indirectly indicate the presence of muscarinic receptor(s) in the visceral organs of the beetle T. molitor. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Heart rate response and functional capacity in patients with chronic heart failure with preserved ejection fraction.

PubMed

Domínguez, Eloy; Palau, Patricia; Núñez, Eduardo; Ramón, José María; López, Laura; Melero, Joana; Bellver, Alejandro; Santas, Enrique; Chorro, Francisco J; Núñez, Julio

2018-03-24

The mechanisms of exercise intolerance in heart failure with preserved ejection fraction (HFpEF) are not yet elucidated. Chronotropic incompetence has emerged as a potential mechanism. We aimed to evaluate whether heart rate (HR) response to exercise is associated to functional capacity in patients with symptomatic HFpEF. We prospectively studied 74 HFpEF patients [35.1% New York Heart Association Class III, 53% female, age (mean ± standard deviation) 72.5 ± 9.1 years, and 59.5% atrial fibrillation]. Functional performance was assessed by peak oxygen consumption (peak VO 2 ). The mean (standard deviation) peak VO 2 was 10 ± 2.8 mL/min/kg. The following chronotropic parameters were calculated: Delta-HR (HR at peak exercise - HR at rest), chronotropic index (CI) = (HR at peak exercise - resting HR)/[(220 - age) - resting HR], and CI according to the equation developed by Keteyian et al. (CIK) (HR at peak exercise - HR at rest)/[119 + (HR at rest/2) - (age/2) - 5 - HR at rest]. In a bivariate setting, peak VO 2 was positively and significantly correlated with Delta-HR (r = 0.35, P = 0.003), CI (r = 0.27, P = 0.022), CIK (r = 0.28, P = 0.018), and borderline with HR at peak exercise (r = 0.22, P = 0.055). In a multivariable linear regression analysis that included clinical, analytical, echocardiographic, and functional capacity covariates, the chronotropic parameters were positively associated with peak VO 2 . We found a linear relationship between Delta-HR and peak VO 2 (β coefficient of 0.03; 95% confidence interval: 0.004-0.05; P = 0.030); conversely, the association among CIs and peak VO 2 was exponentially shaped. In patients with chronic HFpEF, the HR response to exercise was positively associated to patient's functional capacity. © 2018 The Authors. ESC Heart Failure published by John Wiley & Sons Ltd on behalf of the European Society of Cardiology.

Manipulation-free cultures of human iPSC-derived cardiomyocytes offer a novel screening method for cardiotoxicity.

PubMed

Rajasingh, Sheeja; Isai, Dona Greta; Samanta, Saheli; Zhou, Zhi-Gang; Dawn, Buddhadeb; Kinsey, William H; Czirok, Andras; Rajasingh, Johnson

2018-04-05

Induced pluripotent stem cell (iPSC)-based cardiac regenerative medicine requires the efficient generation, structural soundness and proper functioning of mature cardiomyocytes, derived from the patient's somatic cells. The most important functional property of cardiomyocytes is the ability to contract. Currently available methods routinely used to test and quantify cardiomyocyte function involve techniques that are labor-intensive, invasive, require sophisticated instruments or can adversely affect cell vitality. We recently developed optical flow imaging method analyses and quantified cardiomyocyte contractile kinetics from video microscopic recordings without compromising cell quality. Specifically, our automated particle image velocimetry (PIV) analysis of phase-contrast video images captured at a high frame rate yields statistical measures characterizing the beating frequency, amplitude, average waveform and beat-to-beat variations. Thus, it can be a powerful assessment tool to monitor cardiomyocyte quality and maturity. Here we demonstrate the ability of our analysis to characterize the chronotropic responses of human iPSC-derived cardiomyocytes to a panel of ion channel modulators and also to doxorubicin, a chemotherapy agent with known cardiotoxic side effects. We conclude that the PIV-derived beat patterns can identify the elongation or shortening of specific phases in the contractility cycle, and the obtained chronotropic responses are in accord with known clinical outcomes. Hence, this system can serve as a powerful tool to screen the new and currently available pharmacological compounds for cardiotoxic effects.

Chronotropic and pressor effects of water ingestion at rest and in response to incremental dynamic exercise.

PubMed

Mendonca, Goncalo V; Teixeira, Micael S; Heffernan, Kevin S; Fernhall, Bo

2013-06-01

Ingestion of water attenuates the chronotropic response to submaximal exercise. However, it is not known whether this effect is equally manifested during dynamic exercise below and above the ventilatory threshold (VT). We explored the effects of water ingestion on the heart rate response to an incremental cycle-ergometer protocol. In a randomized fashion, 19 healthy adults (10 men and nine women, age 20.9 ± 1.8 years) ingested 50 and 500 ml of water before completing a cycle-ergometer protocol on two separate days. The heart rate and oxygen uptake ( ) responses to water ingestion were analysed both at rest and during exercise performed below and above the VT. The effects of water intake on brachial blood pressure were measured only at rest. Resting mean arterial pressure increased and resting heart rate decreased, but only after 500 ml of water (P < 0.05). Compared with that seen after 50 ml of water, the 500 ml volume elicited an overall decrease in submaximal heart rate (P < 0.05). In contrast, drinking 500 ml of water did not affect submaximal . The participants' maximal heart rate, maximal and VT were similar between conditions. Our results therefore indicate that, owing to its effects on submaximal heart rate over a broad spectrum of intensities, the drinking of water should be recognized as a potential confounder in cardiovascular exercise studies. However, by showing no differences between conditions for submaximal , they also suggest that the magnitude of heart rate reduction after drinking 500 ml of water may be of minimal physiological significance for exercise cardiorespiratory capacity.

Effects of GABA, Neural Regulation, and Intrinsic Cardiac Factors on Heart Rate Variability in Zebrafish Larvae.

PubMed

Vargas, Rafael Antonio

2017-04-01

Heart rate (HR) is a periodic activity that is variable over time due to intrinsic cardiac factors and extrinsic neural control, largely by the autonomic nervous system. Heart rate variability (HRV) is analyzed by measuring consecutive beat-to-beat intervals. This variability can contain information about the factors regulating cardiac activity under normal and pathological conditions, but the information obtained from such analyses is not yet fully understood. In this article, HRV in zebrafish larvae was evaluated under normal conditions and under the effect of substances that modify intrinsic cardiac activity and cardiac activity modulated by the nervous system. We found that the factors affecting intrinsic activity have negative chronotropic and arrhythmogenic effects at this stage of development, whereas neural modulatory factors have a lesser impact. The results suggest that cardiac activity largely depends on the intrinsic properties of the heart tissue in the early stages of development and, to a lesser extent, in the maturing nervous system. We also report, for the first time, the influence of the neurotransmitter gamma amino butyric acid on HRV. The results demonstrate the larval zebrafish model as a useful tool in the study of intrinsic cardiac activity and its role in heart diseases.

Elderly patients with suspected chronic digoxin toxicity: A comparison of clinical characteristics of patients receiving and not receiving digoxin-Fab.

PubMed

Arbabian, Hooman; Lee, Hwee Min; Graudins, Andis

2018-04-01

The aim of the present study was to compare clinical features of patients with elevated serum digoxin concentrations who were treated with digoxin-Fab with those where the immunotherapy was not given by a tertiary hospital toxicology service. This was a retrospective series of patients with supratherapeutic serum digoxin concentrations referred to the toxicology service from August 2013 to October 2015. Data collected included demographics, presenting complaint, digoxin dose, other medications taken, serum digoxin, potassium and creatinine concentration on presentation and initial and post-digoxin-Fab heart rate. There were 47 referrals. Digoxin-Fab was administered in 21 cases. It was given more commonly when the heart rate was <51/min or serum potassium was >5.0 mmol/L. Patients receiving digoxin-Fab were more likely to be on maintenance therapy with beta-blockers or calcium channel blockers (95% vs 61%; OR 13.1; 95% CI 1.5-113) and/or potassium-sparing medications (95% vs 54%; OR 17.1; 95% CI 2.0-147). They had elevated serum creatinine (76% vs 42%; OR 8.2; 95% CI 1.9-34), higher serum potassium (median: 5.1 mmol/L vs 4.2 mmol/L, P = 0.02), higher serum digoxin concentration (median: 3.5 nmol/L vs 2.3 nmol/L, P = 0.02) and pretreatment heart rate <51/min (66% vs 31%; OR 4.5; 95% CI 1.3-15). There were no patients with ventricular arrhythmias or hypotension. Median heart rate increased by 10/min 1 and 4 h after digoxin-Fab. However, individual heart rate response to digoxin-Fab was variable. Digoxin-Fab was more commonly administered when heart rate was <51/min. It had a small effect on increasing heart rate; however, individual response to digoxin-Fab was variable as patients were using other negative chronotropic medications. In symptomatic bradycardic patients on multiple heart failure medications, positive chronotropic and potassium-lowering therapies should be considered in concert with digoxin-Fab. © 2018 Australasian College for Emergency Medicine and Australasian Society for Emergency Medicine.

Cardiovascular and hypokalaemic effects of inhaled salbutamol, fenoterol, and isoprenaline.

PubMed Central

Crane, J; Burgess, C; Beasley, R

1989-01-01

The cardiovascular and hypokalaemic effects of equal doses of inhaled fenoterol, isoprenaline and salbutamol were compared in eight healthy male volunteers, in a double blind, placebo controlled study. Increasing doses of 400, 600, and 800 micrograms were given from a metered dose inhaler at 15 minute intervals, followed by measurements of heart rate, blood pressure, total electromechanical systole (as a measure of inotropic response), QTc interval, and plasma potassium concentration. After repeated inhalation, fenoterol resulted in significantly greater chronotropic, electrocardiographic, and hypokalaemic effects than either isoprenaline or salbutamol. The maximum inotropic effect of fenoterol was similar to that of isoprenaline. PMID:2928998

A cardioactive peptide from the southern armyworm, Spodoptera eridania.

PubMed

Furuya, K; Hackett, M; Cirelli, M A; Schegg, K M; Wang, H; Shabanowitz, J; Hunt, D F; Schooley, D A

1999-01-01

A cardioactive peptide was isolated from extracts of whole heads of the southern armyworm, Spodoptera eridania. This peptide has the sequence ENFAVGCTPGYQRTADGRCKPTF (Mr = 2516.8), determined from both Edman sequencing and tandem mass spectrometry in combination with off-line micropreparative capillary liquid chromatography. This peptide, termed Spoer-CAP23, has excitatory effects on a semi-isolated heart from larval Manduca sexta, causing an inotropic effect at low concentrations of peptide and chronotropic and inotropic effects at high doses. The threshold concentration for stimulatory effects of the synthetic peptide on the semi-isolated heart was about 1 nM, suggesting a physiological role as a neuropeptide.

Electrophysiological effects of FK664, a new cardiotonic agent, on preparations from guinea pig ventricle and from rabbit sino-atrial node.

PubMed

Kodama, I; Anno, T; Sudo, Y; Satake, N; Shibata, S

1989-05-01

Effects of the cardiotonic agent FK664, 6-(3, 4-dimethoxy-phenyl)-1-ethyl-4-mesitylimino-3-methyl-3,4-dihydro-2 (1H)-pyrimidone, on isolated guinea pig ventricular muscles and rabbit sinus node pacemaker cells were studied using micro-electrode techniques. In ventricular muscles driven at 0.5-1.0 Hz, FK664 above 3 mumol.litre-1 caused an increase in contractile force and a shortening of time to peak tension. This positive inotropic effect of FK664 was accompanied by a slight elevation of the early plateau phase of the action potential, while other action potential variables were unaffected. The change in contractile force induced by FK664 was abolished in a low Ca2+ medium (0.12 mmol.litre-1) or by treatment with ryanodine (2 mumol.litre-1), whereas it was relatively well preserved in the preparations pretreated with nefedipine (1 mumol.litre-1). The slow action potentials induced by isoprenaline (0.3 mumol.litre-1) in high K+ medium (30 mmol.litre-1) and the slow inward current measured by single sucrose gap voltage clamp at a holding potential of -40 mV were unaffected by FK664. In sinus node pacemaker cells, FK664 (1-10 mumol.litre-1) caused a dose dependent acceleration of phase 4 depolarisation and a shortening of spontaneous firing cycle length. This positive chronotropic effect of FK664 was markedly inhibited in a low Ca2+ medium (0.3 mmol.litre-1). These findings suggest that FK664 has positive inotropic and chronotropic effects on the heart, due to an enhancement of transsarcolemmal calcium influx through the low threshold, dihydropyridine insensitive Ca2+ channel population.

Importance of heart rate during exercise for response to cardiac resynchronization therapy.

PubMed

Maass, Alexander H; Buck, Sandra; Nieuwland, Wybe; Brügemann, Johan; van Veldhuisen, Dirk J; Van Gelder, Isabelle C

2009-07-01

Cardiac resynchronization therapy (CRT) is an established therapy for patients with severe heart failure and mechanical dyssynchrony. Response is only achieved in 60-70% of patients. To study exercise-related factors predicting response to CRT. We retrospectively examined consecutive patients in whom a CRT device was implanted. All underwent cardiopulmonary exercise testing prior to implantation and after 6 months. The occurrence of chronotropic incompetence and heart rates exceeding the upper rate of the device, thereby compromising biventricular stimulation, was studied. Response was defined as a decrease in LVESV of 10% or more after 6 months. We included 144 patients. After 6 months 86 (60%) patients were responders. Peak VO2 significantly increased in responders. Chronotropic incompetence was more frequently seen in nonresponders (21 [36%] vs 9 [10%], P = 0.03), mostly in patients in SR. At moderate exercise, defined as 25% of the maximal exercise tolerance, that is, comparable to daily life exercise, nonresponders more frequently went above the upper rate of the device (13 [22%] vs 2 [3%], P < 0.0001), most of whom were patients in permanent AF. Multivariate analysis revealed heart rates not exceeding the upper rate of the device during moderate exercise (OR 15.8 [3.3-76.5], P = 0.001) and nonischemic cardiomyopathy (OR 2.4 [1.0-5.7], P = 0.04) as predictive for response. Heart rate exceeding the upper rate during moderate exercise is an independent predictor for nonresponse to CRT in patients with AF, whereas chronotropic incompetence is a predictor for patients in SR.

Asymmetry in the control of cardiac performance by dorsomedial hypothalamus.

PubMed

Xavier, Carlos Henrique; Beig, Mirza Irfan; Ianzer, Danielle; Fontes, Marco Antônio Peliky; Nalivaiko, Eugene

2013-04-15

Dorsomedial hypothalamus (DMH) plays a key role in integrating cardiovascular responses to stress. We have recently reported greater heart rate responses following disinhibition of the right side of the DMH (R-DMH) in anesthetized rats and greater suppression of stress-induced tachycardia following inhibition of the R-DMH in conscious rats [both compared with similar intervention in the left DMH (L-DMH)], suggesting existence of right/left side asymmetry in controlling cardiac chronotropic responses by the DMH. The aim of the present study was to determine whether similar asymmetry is present for controlling cardiac contractility. In anesthetized rats, microinjections of the GABAA antagonist bicuculline methiodide (BMI; 40 pmol/100 nl) into the DMH-evoked increases in heart rate (HR), left ventricular pressure (LVP), myocardial contractility (LVdP/dt), arterial pressure, and respiratory rate. DMH disinhibition also precipitated multiple ventricular and supraventricular ectopic beats. DMH-induced increases in HR, LVP, LVdP/dt, and in the number of ectopic beats dependent on the side of stimulation, with R-DMH provoking larger responses. In contrast, pressor and respiratory responses did not depend on the side of stimulation. Newly described DMH-induced inotropic responses were rate-, preload- and (largely) afterload-independent; they were mediated by sympathetic cardiac pathway, as revealed by their sensitivity to β-adrenergic blockade. We conclude that recruitment of DMH neurons causes sympathetically mediated positive chronotropic and inotropic effects, and that there is an asymmetry, at the level of the DMH, in the potency to elicit these effects, with R-DMH > L-DMH.

5-HT stimulation of heart rate in Drosophila does not act through cAMP as revealed by pharmacogenetics.

PubMed

Majeed, Zana R; Nichols, Charles D; Cooper, Robin L

2013-12-01

The fruit fly, Drosophila melanogaster, is a good experimental organism to study the underlying mechanism of heart rate (HR) regulation. It is already known that many neuromodulators (serotonin, dopamine, octopamine, acetylcholine) change the HR in Drosophila melanogaster larvae. In this study, we investigated the role of cAMP-PKA signaling pathway in HR regulation and 5-HT positive chronotropic action. In order to obtain insight into the 5-HT mechanism of action in larvae cardiomyocytes, genetic and pharmacological approaches were used. We used transgenic flies that expressed the hM4Di receptor [designer receptors exclusively activated by designer drugs (DREADDs)] as one tool. Our previous results showed that activation of hM4Di receptors (modified muscarinic acetylcholine receptors) decreases or arrests the heart from beating. In this study, it was hypothesized that the positive chronotropic effect of serotonin [5-hydroxytryptamine (5-HT)] are mediated by serotonin receptors coupled to the adenylyl cyclase pathway and downstream cAMP and PKA activity. Activation of hM4Di by clozapine-N-oxide (CNO) was predicted to block the effects of serotonin by inhibiting adenylyl cyclase activity through Gαi pathway activation. Interestingly, we found here that manipulation of adenylyl cyclase activity and cAMP levels had no significant effect on HR. The ability of hM4Di receptor activation to slow or stop the heart is therefore likely mediated by activation of GIRK channels to produce hyperpolarization of cardiomyocytes, and not through inhibition of adenylyl cyclase.

Cardiovascular effects of Nemopilema nomurai (Scyphozoa: Rhizostomeae) jellyfish venom in rats.

PubMed

Kim, Euikyung; Lee, Seunghwan; Kim, Jong-Shu; Yoon, Won Duk; Lim, Donghyun; Hart, Andrew J; Hodgson, Wayne C

2006-12-15

Over the past few years, populations of the giant jellyfish Nemopilema nomurai (Scyphozoa: Rhizostomeae) have increased dramatically in the waters of China, Korea, and Japan without any definitive reason. This has resulted in severe damage to fisheries in the areas. During a pilot study, we observed that the venom of N. nomurai produced a functional cardiac depression in mice. However, the mechanism of action was not examined. In the present study, we investigated the cardiovascular effects of nematocyst-derived venom from N. nomurai in anesthetized rats. Venom (0.1-2.4 mg protein/kg, i.v.) produced dose-dependent hypotension (65+/-12% of initial at a cumulative dose of 3 mg/kg) and bradycardia (80+/-5% of initial at a cumulative dose of 3 mg/kg). At the highest dose, this was characterized by a transient decrease in blood pressure (phase 1) followed by a return to basal level and then a slower decrease in blood pressure (phase 2). Venom also produced a decrease in rate and force of contraction in the rat isolated atria. Interestingly, venom induced a contraction of isolated aortic rings which was blocked by felodipine but not by prazosin, suggesting the contraction is mediated by calcium channel activation. These results suggest that the negative inotropic and chronotropic effects of the venom of N. nomurai may be due to a direct effect on the heart.

Desensitization by noradrenaline of responses to stimulation of pre- and postsynaptic adrenoceptors

PubMed Central

Ball, N.; Danks, J.L.; Dorudi, S.; Nasmyth, P.A.

1982-01-01

1 The effect of exposing isolated preparations of rat aortic strip, rat atria and mouse vas deferens to perfusions of Krebs solution containing various concentrations of noradrenaline on their sensitivity to the drug has been determined. 2 The responses evoked by stimulation of postsynaptic adrenoceptors in all the tissues and presynaptic α-adrenoceptors in the mouse vas deferens were diminished by the perfusion of noradrenaline through the organ bath for 30 min. 3 The concentration of noradrenaline required to produce desensitization was higher in the mouse vas deferens than in the other tissues and more was required to desensitize the chronotropic responses than the inotropic responses in rat isolated atria. 4 The inclusion of cocaine (10-5 M) in the bathing solution to block uptake1 increased the sensitivity of most tissues to noradrenaline. With the possible exception of the response to stimulation of presynaptic receptors in the mouse vas deferens, desensitization was somewhat increased in its presence. 5 When uptake2 was blocked by oestradiol (10-5 M), it was not possible to desensitize the contractor responses of the aortic strip and vas deferens to exogenous noradrenaline, nor the inotropic response of the atria to the drug. However, oestradiol failed to block the desensitization of chronotropic responses and responses to stimulation of presynaptic receptors in the vas deferens. 6 Blockade of monoamine oxidase (MAO) with iproniazid (7.2 × 10-4 M) or with pargyline (5 × 10-4 M) did not affect the desensitization process in the aortic strip. 7 Blockade of catechol-O-methyltransferase (COMT) with U-0521 (5.3 × 10-5 M) greatly increased desensitization in the aortic strip and desensitization of inotropic responses in the atria. It had no effect on desensitization of chronotropic responses. Its effect on responses in the mouse vas deferens was not determined. 8 The perfusion of methoxamine at concentrations about 1000 times higher than those of noradrenaline also produced desensitization in the aortic strip. 9 The desensitization of presynaptic receptors in the mouse vas deferens was shown to be specific and that of the responses to postsynaptic receptor stimulation to be non-specific. 10 It is concluded that responses to adrenoceptor stimulation may be desensitized by accumulation of noradrenaline inside the cells bearing the receptors and that the desensitization is caused by noradrenaline itself not by a metabolite. Desensitization may also be caused without accumulation of noradrenaline in uptake2 and for some receptors these may not be alternative mechanisms. PMID:7082904

Study of the in vivo and in vitro cardiovascular effects of a hydralazine-like vasodilator agent (HPS-10) in normotensive rats

PubMed Central

Orallo, Francisco

1997-01-01

In this work, the cardiovascular effects of HPS-10, a new vasodilator agent, were studied in rats. In conscious normotensive rats, oral administration of HPS-10 (4–9 mg kg−1) produced a dose-related and long-lasting fall in systolic arterial blood pressure (ED30 of 5.32 mg kg−1), accompanied by an increase in heart rate (ED30 of 8.43 mg kg−1). This tachycardia was totally inhibited by pretreatment with (±)-propranolol (10 mg kg−1, p.o.). In anaesthetized normotensive rats, HPS-10 (0.3–0.6 mg kg−1, i.v.) produced a gradual, dose-dependent and sustained decrease in systolic, diastolic and mean arterial pressure (MAP) (ED30 for MAP of 0.41 mg kg−1, i.v.), accompanied by a significant bradycardia at high doses (>0.4 mg kg−1; ED20 of 0.61 mg kg−1, i.v.). HPS-10 (0.5 mg kg−1, i.v.) did not modify the positive chronotropic effects induced by intravenous administration of noradrenaline (NA; 5 μg kg−1), angiotensin II (AII; 0.2 μg kg−1) and nicotine (200 μg kg−1) but markedly inhibited the hypertensive response produced by these agents. In rat isolated rubbed aorta, HPS-10 (0.1–1 mM) non-competitively and with almost equal effectiveness antagonized the contractions induced by NA, AII (in normal Krebs solution) and Ca2+ (in depolarizing Ca2+-free high-K+ 50 mM solution). In the experiments in Ca2+-free medium, HPS-10 (1 mM) considerably inhibited the contractions induced by NA, AII and caffeine in rat aorta. Furthermore, in the studies with radioactive Ca2+, HPS-10 (1 mM) did not modify the basal uptake of 45Ca2+ but strongly decreased the influx of 45Ca2+ induced by NA, AII and K+ in rat aortic rings. In rat isolated atria, HPS-10 (1 mM) produced a positive inotropic/negative chronotropic effect. HPS-10 (0.3 mM) significantly inhibited the sustained and transient Ba2+ inward current (IBa) recorded in whole-cell clamped rat aortic myocytes. These results indicate that the non-selective vasorelaxant effects of HPS-10 in rat aortic rings can be attributed to transmembrane Ca2+-antagonist activity and an intracellular action on smooth muscle cells. The direct vasodilator action of HPS-10 observed in rat isolated aorta may be responsible for the HPS-10 hypotensive activity in anaesthetized normotensive rats. PMID:9283696

The use of adenosine and adenosine triphosphate testing in the diagnosis, risk stratification and management of patients with syncope: current evidence and future perspectives.

PubMed

Fragakis, Nikolaos; Antoniadis, Antonios P; Saviano, Massimo; Vassilikos, Vassilios; Pappone, Carlo

2015-03-15

Syncope is a significant source of cardiovascular-related morbidity yet the etiology is frequently obscure and the identification of patients at highest risk is challenging. Adenosine (AD) and adenosine triphosphate (ATP) administrations have been suggested as potentially useful non-invasive tools in the diagnostic workup of patients with neurally-mediated or bradycardia-related syncope. It has been postulated that both compounds by modulating the autonomic innervation in the heart and exerting negative chronotropic and dromotropic effects in the conduction system, may unmask the mechanism of syncope. However, the clinical implications derived from the efficacy of both tests in the investigation of syncope remain unclear mainly due to inconclusive and occasionally contradictory results of published studies. This review article summarizes recent and past information in the use of ATP and AD in the investigation of syncope with emphasis on clinical trials. We present the current level of evidence for the use of these agents in clinical practice, identify areas where further research is warranted and highlight the future perspectives of these agents as complements to an accurate risk-stratification of patients with syncope. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Embryological development of pacemaker hierarchy and membrane currents related to the function of the adult sinus node: implications for autonomic modulation of biopacemakers.

PubMed

Opthof, Tobias

2007-02-01

The sinus node is an inhomogeneous structure. In the embryonic heart all myocytes have sinus node type pacemaker channels (I (f)) in their sarcolemma. Shortly before birth, these channels disappear from the ventricular myocytes. The response of the adult sinus node to changes in the interstitium, in particular to (neuro)transmitters, results from the interplay between the responses of all of its constituent cells. The response of the whole sinus node cannot be simply deduced from these cellular responses, because all cells have different responses to specific agonists. A biological pacemaker will be more homogeneous. Therefore it can be anticipated that tuning of cycle length may be problematic. It is discussed that efforts to create a biological pacemaker responsive to vagal stimulation, may be counterproductive, because it may have the potential risk of 'standstill' of the biological pacemaker. A normal sinus node remains spontaneously active at high concentrations of acetylcholine, because it has areas that are unresponsive to acetylcholine. The same is pertinent to other substances with a negative chronotropic effect. Such functional inhomogeneity is lacking in biological pacemakers.

Phytochemical and pharmacological activity profile of Crataegus oxyacantha L. (hawthorn) - A cardiotonic herb.

PubMed

Orhan, Ilkay Erdogan

2016-09-18

Crataegus oxyacantha L. (syn. C. rhipidophylla Gand.) (Rosaceae) is one of two medicinally recognized hawthorn species in European Pharmacopeia. Standardization of the extract prepared from the berry and flowers of the plant is required according to its oligomeric procyanidins. C. oxyacantha is well-known for its use in the treatment of various heart problems particularly, including heart failure in cases of declining cardiac performance equivalent to stages I and II of the New York Heart Association classification, angina pectoris, hypertension with myocardial insufficiency, mild alterations of cardiac rhythm, and atherosclerosis. C. oxyacantha has been reported to exert several other pharmacological activities such as hypotensive, antihyperlipidemic, antihyperglycemic, anxiolytic, immunomodulatory, and antimutagenic. Oligomeric procyanidins and flavone/flavonol types of flavonoids, which are considered to be the chief groups of active substances, phenolic acids, triterpenes, fatty acids, and sterols are present in the plant. The present review aims mainly to outline cardiotonic effect of C. oxyacantha as well as its brief phytochemistry. Numerous experiments and clinical studies have underlined cardiovascular efficacy of the plant through various mechanisms including positive inotropic and negative chronotropic effects, escalation in coronary blood flow and exercise tolerance, inhibition of the enzymes such as angiotensin-converting enzyme (ACE) and phosphodiesterase, anti-inflammatory and antihyperlipidemic effects, improving status of antioxidant enzymes, etc., which support its cardioactive efficacy. The plant possesses several other bioactivities for human health usually concomitant to its rich polyphenolic content.

Heart rate variability in newborns.

PubMed

Javorka, K; Lehotska, Z; Kozar, M; Uhrikova, Z; Kolarovszki, B; Javorka, M; Zibolen, M

2017-09-22

Heart rate (HR) and heart rate variability (HRV) in newborns is influenced by genetic determinants, gestational and postnatal age, and other variables. Premature infants have a reduced HRV. In neonatal HRV evaluated by spectral analysis, a dominant activity can be found in low frequency (LF) band (combined parasympathetic and sympathetic component). During the first postnatal days the activity in the high frequency (HF) band (parasympathetic component) rises, together with an increase in LF band and total HRV. Hypotrophy in newborn can cause less mature autonomic cardiac control with a higher contribution of sympathetic activity to HRV as demonstrated by sequence plot analysis. During quiet sleep (QS) in newborns HF oscillations increase - a phenomenon less expressed or missing in premature infants. In active sleep (AS), HRV is enhanced in contrast to reduced activity in HF band due to the rise of spectral activity in LF band. Comparison of the HR and HRV in newborns born by physiological vaginal delivery, without (VD) and with epidural anesthesia (EDA) and via sectio cesarea (SC) showed no significant differences in HR and in HRV time domain parameters. Analysis in the frequency domain revealed, that the lowest sympathetic activity in chronotropic cardiac chronotropic regulation is in the VD group. Different neonatal pathological states can be associated with a reduction of HRV and an improvement in the health conditions is followed by changes in HRV what can be use as a possible prognostic marker. Examination of heart rate variability in neonatology can provide information on the maturity of the cardiac chronotropic regulation in early postnatal life, on postnatal adaptation and in pathological conditions about the potential dysregulation of cardiac function in newborns, especially in preterm infants.

The COGNITION study rationale and design: influence of closed loop stimulation on cognitive performance in pacemaker patients.

PubMed

Wiegand, Uwe; Nuernberg, Michael; Maier, Sebastian K G; Weiss, Christian; Sancho-Tello, María-José; Hartmann, Andreas; Schuchert, Andreas; Maier, Petra; Chan, Ngai-Yin

2008-06-01

Several studies showed the beneficial effect of pacemaker implantation on cognitive performance in patients with bradycardia. But it has never been investigated if patients with chronotropic incompetence may improve their cognitive performance if treated by a rate-adaptive system reacting to mental stress in comparison to the most frequently used accelerometer-driven pacing. The randomized, single-blind, multicenter COGNITION study evaluates if closed loop stimulation (CLS) offers incremental benefit in the speed of cognitive performance and the overall well-being of elderly patients with bradycardia compared with accelerometer-based pacing. Four hundred chronotropically incompetent patients older than 55 years will be randomized 3-6 weeks after implantation to CLS or accelerometer sensor. Follow-up visits are performed after 12 and 24 months. The speed of cognitive performance, which is the underlying function influencing all other aspects of cognitive performance, will be assessed by the number connection test, a standardized psychometric test for the elderly. Secondary endpoints include patient self-assessment of different aspects of health (by visual analogue scales), quality of life (by SF-8 health survey), the incidence of atrial fibrillation (episodes lasting for longer than 24 hours), and the frequency of serious adverse events. In the ongoing COGNITION study, we aim at long-term comparison of two rate-adaptive systems, focusing on the cognitive performance of the patients, which was neglected in the past evaluation of pacemaker sensors.

The effect of endotoxin on heart rate dynamics in diabetic rats.

PubMed

Meamar, Morvarid; Dehpour, Tara; Mazloom, Roham; Sharifi, Fatemeh; Raoufy, Mohammad R; Dehpour, Ahmad R; Mani, Ali R

2015-05-01

The effect of endotoxin on heart rate variability (HRV) was assessed in diabetic and controls rats using a telemetric system. Endotoxin induced a reduction in sample entropy of cardiac rhythm in control animals. However, this effect was significantly blunted in streptozotocin-induced diabetic rats. Since uncoupling of cardiac pacemaker from cholinergic control is linked to reduced HRV in endotoxemia, chronotropic responsiveness to cholinergic stimulation was assessed in isolated atria. Endotoxemia was associated with impaired responsiveness to carbacholine in control rats. However, endotoxemia did not impair cholinergic responsiveness in diabetic atria. These findings corroborates with development of endotoxin tolerance in diabetic rats. Copyright © 2014 Elsevier B.V. All rights reserved.

Exaggerated cardiovascular effects of cocaine in conscious dogs with pacing-induced dilated cardiomyopathy.

PubMed

Mathier, Michael A; Shen, You-Tang; Shannon, Richard P

2002-12-01

The aim of this study was to explore the characteristics and mechanisms of the cardiovascular effects of cocaine in dilated cardiomyopathy. We studied the cardiovascular responses to acute intravenous cocaine (1 mg/kg) in 8 conscious, chronically instrumented dogs before and after the development of dilated cardiomyopathy induced by rapid ventricular pacing. To help elucidate the role of altered baroreflex function in mediating the cardiovascular effects of cocaine, we also studied responses in 3 conscious, chronically instrumented dogs that had undergone surgical sinoaortic baroreceptor denervation. Cocaine produced greater increases in heart rate (+57 +/- 8% from 112 +/- 5 beats/min versus +28 +/- 3% from 100 +/- 4 beats/min; P <.01), first derivative of left ventricular pressure (+30 +/- 5% from 1,714 +/- 147 mm Hg/sec versus +15 +/- 3% from 3,032 +/- 199 mm Hg/sec; P <.01), coronary vascular resistance (+28 +/- 5% from 2.3 +/- 0.3 mm Hg/mL/min versus +11 +/- 5% from 2.2 +/- 0.3 mm Hg/mL/min; P <.05) and plasma norepinephrine concentration (+130 +/- 31% from 462 +/- 102 pg/mL versus +86 +/- 32% from 286 +/- 77 pg/mL; P <.05) in dogs with dilated cardiomyopathy as compared to controls. In addition, responses were much more rapid in onset following the development of dilated cardiomyopathy. Chronotropic and inotropic responses to cocaine were similarly rapid and exaggerated in dogs after baroreceptor denervation. Cocaine produces rapid and exaggerated chronotropic, inotropic, and coronary vasoconstrictor responses in conscious dogs with pacing-induced dilated cardiomyopathy. Alterations in arterial baroreflex function may play a role in these observations, which in turn may underlie the clinically observed association between cocaine and heart failure.

Impact of Age and Polytherapy on Fingolimod Induced Bradycardia: a Preclinical Study.

PubMed

Ritter, Christian; Svačina, Martin K R; Bobylev, Ilja; Joshi, Abhijeet; Schneider, Toni; Lehmann, Helmar C

2017-03-01

Fingolimod is a an oral disease modifying drug for relapsing remitting multiple sclerosis (MS) preventing egress of B and T cells from lymph nodes. Relevant first dose adverse events include bradycardia and atrioventricular conduction slowing. Cardiac side effects of fingolimod and combinational pharmacotherapy including duloxetine and tolterodine were monitored in mice of different age using implantable ECG telemetric systems. Cardiac tissue was assessed for S1P-receptor subtype (1 and 3), and for GIRK1 expression. Fingolimod led to a significant heart rate reduction within 60 min, which returned to baseline values within 24 h. In older mice bradycardia was more pronounced compared to younger mice. Atrioventricular conduction was not affected. Older mice showed a higher S1PR3 expression in a naïve state and receptor expression was reduced after fingolimod administration. Combination with duloxetine or tolterodine alleviated fingolimod induced heart rate decrease. Our data provide preclinical evidence that negative chronotropic effects of fingolimod might be age dependent, possibly due to an altered expression and internalization of cardiac S1PR3 in older animals. This data could be relevant for future clinical monitoring and patient selection in the aging MS population. Combinational therapies of fingolimod and duloxetine or tolterodine are well tolerated and safe without an increased risk for pronounced bradycardia or arrhythmia.

Caffeine depression of spontaneous activity in rabbit sino-atrial node cells.

PubMed

Satoh, H

1993-05-01

1. Effects of caffeine on the action potentials and the membrane currents in spontaneously beating rabbit sino-atrial (SA) node cells were examined using a two-microelectrode technique. 2. Cumulative administrations of caffeine (1-10 mM) caused a negative chronotropic effect in a concentration-dependent manner, which was not modified by atropine (0.1 microM). At 10 mM, caffeine increased the amplitude and prolonged the duration of action potentials significantly; the other parameters were unaffected. 3. In 3 of 16 preparations, caffeine (5 mM) elicited arrhythmia. At high Ca2+ (8.1 mM), caffeine (5 mM) increased the incidence of arrhythmia. 4. Caffeine (0.5-10 mM) enhanced the slow inward current, but at 10 mM decreased the enhanced peak current by 5 mM. The hyperpolarization-activated inward current was also enhanced by caffeine, but 10 mM caffeine decreased the current peak as compared with that at 5 mM. In addition, caffeine inhibited the delayed rectifying outward current in a concentration-dependent manner, accompanied by a depressed activation curve without any shift in the half-maximum activation voltage. 5. Caffeine elevated the cytoplasmic Ca2+ level in the SA node cells loaded with Ca(2+)-sensitive fluorescent dye (fura-2). 6. These results suggest that caffeine enhances and/or inhibits the ionic currents and elicits arrhythmia due to the induction of cellular calcium overload.

Essential Role of the m2R-RGS6-IKACh Pathway in Controlling Intrinsic Heart Rate Variability

PubMed Central

Posokhova, Ekaterina; Ng, David; Opel, Aaisha; Masuho, Ikuo; Tinker, Andrew; Biesecker, Leslie G.; Wickman, Kevin; Martemyanov, Kirill A.

2013-01-01

Normal heart function requires generation of a regular rhythm by sinoatrial pacemaker cells and the alteration of this spontaneous heart rate by the autonomic input to match physiological demand. However, the molecular mechanisms that ensure consistent periodicity of cardiac contractions and fine tuning of this process by autonomic system are not completely understood. Here we examined the contribution of the m2R-IKACh intracellular signaling pathway, which mediates the negative chronotropic effect of parasympathetic stimulation, to the regulation of the cardiac pacemaking rhythm. Using isolated heart preparations and single-cell recordings we show that the m2R-IKACh signaling pathway controls the excitability and firing pattern of the sinoatrial cardiomyocytes and determines variability of cardiac rhythm in a manner independent from the autonomic input. Ablation of the major regulator of this pathway, Rgs6, in mice results in irregular cardiac rhythmicity and increases susceptibility to atrial fibrillation. We further identify several human subjects with variants in the RGS6 gene and show that the loss of function in RGS6 correlates with increased heart rate variability. These findings identify the essential role of the m2R-IKACh signaling pathway in the regulation of cardiac sinus rhythm and implicate RGS6 in arrhythmia pathogenesis. PMID:24204714

Mood states, sympathetic activity, and in vivo beta-adrenergic receptor function in a normal population.

PubMed

Yu, Bum-Hee; Kang, Eun-Ho; Ziegler, Michael G; Mills, Paul J; Dimsdale, Joel E

2008-01-01

The purpose of this study was to examine the relationship between mood states and beta-adrenergic receptor function in a normal population. We also examined if sympathetic nervous system activity is related to mood states or beta-adrenergic receptor function. Sixty-two participants aged 25-50 years were enrolled in this study. Mood states were assessed using the Profile of Mood States (POMS). Beta-adrenergic receptor function was determined using the chronotropic 25 dose isoproterenol infusion test. Level of sympathetic nervous system activity was estimated from 24-hr urine norepinephrine excretion. Higher tension-anxiety, depression-dejection, and anger-hostility were related to decreased beta-adrenergic receptor sensitivity (i.e., higher chronotropic 25 dose values), but tension-anxiety was the only remaining independent predictor of beta-adrenergic receptor function after controlling for age, gender, ethnicity, and body mass index (BMI). Urinary norepinephrine excretion was unrelated to either mood states or beta-adrenergic receptor function. These findings replicate previous reports that anxiety is related to decreased (i.e., desensitized) beta-adrenergic receptor sensitivity, even after controlling for age, gender, ethnicity, and body mass index.

Pharmacological and physiological assessment of serotonin formation and degradation in isolated preparations from mouse and human hearts.

PubMed

Gergs, Ulrich; Jung, Franziska; Buchwalow, Igor B; Hofmann, Britt; Simm, Andreas; Treede, Hendrik; Neumann, Joachim

2017-12-01

Using transgenic (TG) mice that overexpress the human serotonin (5-HT) 4a receptor specifically in cardiomyocytes, we wanted to know whether 5-HT can be formed and degraded in the mammalian heart and whether this can likewise lead to inotropic and chronotropic effects in this TG model. We noted that the 5-HT precursor 5-hydroxy-tryptophan (5-HTP) can exert inotropic and chronotropic effects in cardiac preparations from TG mice but not from wild-type (WT) mice; similar results were found in human atrial preparations as well as in intact TG animals using echocardiography. Moreover, by immunohistochemistry we could detect 5-HT metabolizing enzymes and 5-HT transporters in mouse hearts as well as in human atria. Hence, in the presence of an inhibitor of aromatic l-amino acid decarboxylase, the positive inotropic effects of 5-HTP were absent in TG and isolated human atrial preparations, and, moreover, inhibitors of enzymes involved in 5-HT degradation enhanced the efficacy of 5-HT in TG atria. A releaser of neurotransmitters increased inotropy in the isolated TG atrium, and this effect could be blocked by a 5-HT 4a receptor antagonist. Fluoxetine, an inhibitor of 5-HT uptake, elevated the potency of 5-HT to increase contractility in the TG atrium. In addition, inhibitors of organic cation and monoamine transporters apparently reduced the positive inotropic potency of 5-HT in the TG atrium. Hence, we tentatively conclude that a local production and degradation of 5-HT in the mammalian heart and more specifically in mammalian myocytes probably occurs. Conceivably, this formation of 5-HT and possibly impaired degradation may be clinically relevant in cases of unexplained tachycardia and other arrhythmias. NEW & NOTEWORTHY The present work suggests that inotropically active serotonin (5-HT) can be formed in the mouse and human heart and probably by cardiomyocytes themselves. Moreover, active degradation of 5-HT seems to occur in the mammalian heart. These findings may again increase the interest of researchers for cardiac effects of 5-HT. Copyright © 2017 the American Physiological Society.

Resting Bradycardia, Enhanced Postexercise Heart Rate Recovery and Cardiorespiratory Fitness in Recreational Ballroom Dancers

ERIC Educational Resources Information Center

da Cruz, Carlos Janssen Gomes; Molina, Guilherme Eckhardt; Porto, Luiz Guilherme Grossi; Junqueira, Luiz Fernando, Jr.

2017-01-01

Purpose: In a cross-sectional study design, we evaluated the resting heart rate (HR[subscript baseline]) and exercise and postexercise stress test-related chronotropic responses in male practitioners of recreational ballroom dancing (BD; n = 25, M[subscript age] = 26.6 ± 6.1 years) compared to a control group of insufficiently active nondancers…

Single passive leg movement-induced hyperemia: a simple vascular function assessment without a chronotropic response.

PubMed

Venturelli, Massimo; Layec, Gwenael; Trinity, Joel; Hart, Corey R; Broxterman, Ryan M; Richardson, Russell S

2017-01-01

Passive leg movement (PLM)-induced hyperemia is a novel approach to assess vascular function, with a potential clinical role. However, in some instances, the varying chronotropic response induced by PLM has been proposed to be a potentially confounding factor. Therefore, we simplified and modified the PLM model to require just a single PLM (sPLM), an approach that may evoke a peripheral hemodynamic response, allowing a vascular function assessment, but at the same time minimizing central responses. To both characterize and assess the utility of sPLM, in 12 healthy subjects, we measured heart rate (HR), stroke volume, cardiac output (CO), mean arterial pressure (MAP), leg blood flow (LBF), and calculated leg vascular conductance (LVC) during both standard PLM, consisting of passive knee flexion and extension performed at 1 Hz for 60 s, and sPLM, consisting of only a single passive knee flexion and extension over 1 s. During PLM, MAP transiently decreased (5 ± 1 mmHg), whereas both HR and CO increased from baseline (6.0 ± 1.1 beats/min, and 0.8 ± 0.01 l/min, respectively). Following sPLM, MAP fell similarly (5 ± 2 mmHg; P = 0.8), but neither HR nor CO responses were identifiable. The peak LBF and LVC response was similar for PLM (993 ± 189 ml/min; 11.9 ± 1.5 ml·min -1 ·mmHg -1 , respectively) and sPLM (878 ± 119 ml/min; 10.9 ± 1.6 ml·min -1 ·mmHg -1 , respectively). Thus sPLM represents a variant of the PLM approach to assess vascular function that is more easily performed and evokes a peripheral stimulus that induces a significant hyperemia, but does not generate a potentially confounding, chronotropic response, which may make sPLM more useful clinically. Using the single passive leg movement (PLM) technique, a variant of the vascular function assessment PLM, we have identified a novel peripheral vascular assessment method that is more easily performed than PLM, which, by not evoking potentially confounding central hemodynamic responses, may be more useful clinically.

Cholinergic stimulation with pyridostigmine protects against exercise induced myocardial ischaemia

PubMed Central

Castro, R R T; Porphirio, G; Serra, S M; Nóbrega, A C L

2004-01-01

Objective: To determine the acute effects of pyridostigmine bromide, a reversible cholinesterase inhibitor, during exercise in patients with coronary artery disease. Design: Double blind, randomised, placebo controlled, crossover study. Setting: Outpatients evaluated in an exercise test laboratory. Patients: 15 patients with exercise induced myocardial ischaemia. Interventions: Maximal cardiopulmonary exercise test on a treadmill according to an individualised ramp protocol on three days. The first day was used for adaptation to the equipment and to determine exercise tolerance and the presence of exercise induced ischaemia. On the other two days, the cardiopulmonary exercise test was performed two hours after oral administration of pyridostigmine (45 mg) or placebo. All patients were taking their usual medication during the experiments. Main outcome measures: Rate–pressure product and oxygen uptake during exercise. Results: Pyridostigmine inhibited the submaximum chronotropic response (p  =  0.001), delaying the onset of myocardial ischaemia, which occurred at a similar rate–pressure product (mean (SE) placebo 20.55 (1.08) mm Hg × beats/min 103; pyridostigmine 19.75 (1.28) mm Hg × beats/min 103; p  =  0.27) but at a higher exercise intensity (oxygen consumption: placebo 18.6 (1.7) ml/kg/min; pyridostigmine 19.6 (1.8) ml/kg/min; p  =  0.03). Also, pyridostigmine increased peak oxygen consumption (placebo 23.6 (2) ml/kg/min; pyridostigmine 24.8 (2) ml/kg/min; p  =  0.01) and peak oxygen pulse (placebo 12.9 (1) ml/beat; pyridostigmine 13.6 (1) ml/beat; p  =  0.02). Conclusions: Pyridostigmine improved peak exercise tolerance and inhibited the chronotropic response to submaximum exercise, increasing the intensity at which myocardial ischaemia occurred. These results suggest that pyridostigmine can protect against exercise induced myocardial ischaemia. PMID:15367503

A comparison of 2 circuit exercise training techniques for eliciting matched metabolic responses in persons with paraplegia.

PubMed

Nash, Mark S; Jacobs, Patrick L; Woods, Jeffrey M; Clark, James E; Pray, Tanya A; Pumarejo, Alex E

2002-02-01

To test whether acute metabolic (VO(2)), chronotropic (heart rate), and perceptual (rating of perceived exertion; RPE) responses to exercise by persons with paraplegia differ when the exercise is on a multistation isoinertial exercise system (MultiGym) or on a customized system of Thera-Band resistance bands (ElasticGym). Within-subjects comparison of 2 treatments. Academic medical center. Sixteen men and 1 woman with complete paraplegia (T4-L1), as defined by the American Spinal Injury Association. A circuit resistance training (CRT) program for persons with paraplegia was adapted to both a MultiGym and a customized ElasticGym. Exercises used for training and testing used 6 resistance maneuvers at 50% of the 1-repetition maximum (1-RM), with interposed rapid arm spinning. Subjects were habituated to both conditions for 2 weeks before testing on randomized nonconsecutive days. VO(2) (L/min) was measured by portable spirometry, heart rate (beats/min) by a chest strap monitor, and RPE by the Borg Scale of Perceived Exertion (6-20). No significant effects of test condition on average VO(2) or heart rate were observed, with differences between conditions reflecting only .08L/min and 6.4 beats/min, respectively. Average RPE was significantly higher in testing under the ElasticGym condition (P < .05). CRT on a customized ElasticGym system elicited acute metabolic and chronotropic responses that did not differ from responses to exercise on a MultiGym, though RPE was greater with the ElasticGym. Copyright 2002 by the American Congress of Rehabilitation Medicine and the American Academy of Physical Medicine and Rehabilitation

[Vasopressin intravenous infusion causes dose dependent adverse cardiovascular effects in anesthetized dogs.

PubMed

Martins, Luiz Cláudio; Sabha, Maricene; Paganelli, Maria Ondina; Coelho, Otávio Rizzi; Ferreira-Melo, Silvia Elaine; Moreira, Marcos Mello; Cavalho, Adriana Camargo de; Araujo, Sebastião; Moreno Junior, Heitor

2010-01-15

BACKGROUND: Arginine vasopressin (AVP) has been broadly used in the management of vasodilatory shock. However, there are many concerns regarding its clinical use, especially in high doses, as it can be associated with adverse cardiovascular events. OBJECTIVE: To investigate the cardiovascular effects of AVP in continuous IV infusion on hemodynamic parameters in dogs. METHODS: Sixteen healthy mongrel dogs, anesthetized with pentobarbital were intravascularly catheterized, and randomly assigned to: control (saline-placebo; n=8) and AVP (n=8) groups. The study group was infused with AVP for three consecutive 10-minute periods at logarithmically increasing doses (0.01; 0.1 and 1.0U/kg/min), at them 20-min intervals. Heart rate (HR) and intravascular pressures were continuously recorded. Cardiac output was measured by the thermodilution method. RESULTS: No significant hemodynamic effects were observed during 0.01U/kg/min of AVP infusion, but at higher doses (0.1 and 1.0U/kg/min) a progressive increase in mean arterial pressure (MAP) and systemic vascular resistance index (SVRI) were observed, with a significant decrease in HR and the cardiac index (CI). A significant increase in the pulmonary vascular resistance index (PVRI) was also observed with the 1.0U/kg/min dose, mainly due to the decrease in the CI. CONCLUSION: AVP, when administered at doses between 0.1 and 1.0U/kg/min, induced significant increases in MAP and SVRI, with negative inotropic and chronotropic effects in healthy animals. Although these doses are ten to thousand times greater than those routinely used for the management of vasodilatory shock, our data confirm that AVP might be used carefully and under strict hemodynamic monitoring in clinical practice, especially if doses higher than 0.01 U/kg/min are needed. Martins, LC et al.

Inhibitory effects of sevoflurane on pacemaking activity of sinoatrial node cells in guinea-pig heart

PubMed Central

Kojima, Akiko; Kitagawa, Hirotoshi; Omatsu-Kanbe, Mariko; Matsuura, Hiroshi; Nosaka, Shuichi

2012-01-01

BACKGROUND AND PURPOSE The volatile anaesthetic sevoflurane affects heart rate in clinical settings. The present study investigated the effect of sevoflurane on sinoatrial (SA) node automaticity and its underlying ionic mechanisms. EXPERIMENTAL APPROACH Spontaneous action potentials and four ionic currents fundamental for pacemaking, namely, the hyperpolarization-activated cation current (If), T-type and L-type Ca2+ currents (ICa,T and ICa,L, respectively), and slowly activating delayed rectifier K+ current (IKs), were recorded in isolated guinea-pig SA node cells using perforated and conventional whole-cell patch-clamp techniques. Heart rate in guinea-pigs was recorded ex vivo in Langendorff mode and in vivo during sevoflurane inhalation. KEY RESULTS In isolated SA node cells, sevoflurane (0.12–0.71 mM) reduced the firing rate of spontaneous action potentials and its electrical basis, diastolic depolarization rate, in a qualitatively similar concentration-dependent manner. Sevoflurane (0.44 mM) reduced spontaneous firing rate by approximately 25% and decreased If, ICa,T, ICa,L and IKs by 14.4, 31.3, 30.3 and 37.1%, respectively, without significantly affecting voltage dependence of current activation. The negative chronotropic effect of sevoflurane was partly reproduced by a computer simulation of SA node cell electrophysiology. Sevoflurane reduced heart rate in Langendorff-perfused hearts, but not in vivo during sevoflurane inhalation in guinea-pigs. CONCLUSIONS AND IMPLICATIONS Sevoflurane at clinically relevant concentrations slowed diastolic depolarization and thereby reduced pacemaking activity in SA node cells, at least partly due to its inhibitory effect on If, ICa,T and ICa,L. These findings provide an important electrophysiological basis of alterations in heart rate during sevoflurane anaesthesia in clinical settings. PMID:22356456

Effects of hawthorn ( Crataegus pentagyna) leaf extract on electrophysiologic properties of cardiomyocytes derived from human cardiac arrhythmia-specific induced pluripotent stem cells.

PubMed

Pahlavan, Sara; Tousi, Marziyeh Shalchi; Ayyari, Mahdi; Alirezalu, Abolfazl; Ansari, Hassan; Saric, Tomo; Baharvand, Hossein

2018-03-01

Cardiac arrhythmias are major life-threatening conditions. The landmark discovery of induced pluripotent stem cells has provided a promising in vitro system for modeling hereditary cardiac arrhythmias as well as drug development and toxicity testing. Nowadays, nutraceuticals are frequently used as supplements for cardiovascular therapy. Here we studied the cardiac effects of hawthorn ( Crataegus pentagyna) leaf extract using cardiomyocytes (CMs) differentiated from healthy human embryonic stem cells, long QT syndrome type 2 (LQTS2), and catecholaminergic polymorphic ventricular tachycardia type 1 (CPVT1) patient-specific induced pluripotent stem cells. The hydroalcoholic extract resulted in a dose-dependent negative chronotropic effect in all CM preparations leading to a significant reduction at 1000 µg/ml. This was accompanied by prolongation of field potential durations, although with different magnitudes in CMs from different human embryonic stem cell and iPSC lines. Hawthorn further prolonged field potential durations in LQTS2 CMs but reduced the beating frequencies and occurrence of immature field potentials triggered by β 1 -adrenergic stimulation in CPVT1 CMs at 300 and 1000 µg/ml. Furthermore, isoquercetin and vitexin flavonoids significantly slowed down isoproterenol (5 µM)-induced beating frequencies at 3 and 10 µg/ml. Therefore, C. pentagyna leaf extract and its isoquercetin and vitexin flavonoids may be introduced as a novel nutraceutical with antiarrhythmic potential for CPVT1 patients.-Pahlavan, S., Tousi, M. S., Ayyari, M., Alirezalu, A., Ansari, H., Saric, T., Baharvand, H. Effects of hawthorn ( Crataegus pentagyna) leaf extract on electrophysiologic properties of cardiomyocytes derived from human cardiac arrhythmia-specific induced pluripotent stem cells.

Effects of cholinergic and beta-adrenergic blockade on orthostatic tolerance in healthy subjects

NASA Technical Reports Server (NTRS)

Convertino, V. A.; Sather, T. M.

2000-01-01

Cardiovascular responses during a graded lower body negative pressure (LBNP) protocol were compared before and after atropine and propranolol administration to test the hypothesis that both sympathetic and parasympathetic control of cardio-acceleration are associated with syncopal predisposition to orthostatic stress in healthy subjects. Eleven men were categorized into two groups having high (HT, N = 6) or low (LT, N = 5) tolerance based on their total time before the onset of presyncopal symptoms. HT and LT groups were similar in physical characteristics, fitness, and baseline cardiovascular measurements. Atropine treatment had no effect on LBNP tolerance or mean arterial pressure at presyncope, despite an atropine-induced increase in heart rate. Propranolol treatment reduced (p<0.05) LBNP tolerance in both groups. Diminished LBNP tolerance after propranolol administration was associated with reductions in cardiac output, whereas increase in systemic peripheral resistance from baseline to presyncope was unaffected by propranolol. Reduction in cardiac output and LBNP tolerance after beta blockade reflected a chronotropic effect because lower LBNP tolerance for the HT (-50%) and LT (-39%) groups was associated with dramatic reductions (p <0.05) in the magnitude of LBNP-induced tachycardia without significant effects on stroke volume at presyncope. Absence of an atropine-induced difference in cardiac output and systemic peripheral resistance between HT and LT groups failed to support the notion that cardiac vagal withdrawal represents a predominant mechanism that could account for differences in orthostatic tolerance. Because a reduction in LBNP tolerance in both HT and LT groups after propranolol treatment was most closely associated with reduced tachycardia, the data suggest that a primary autonomically mediated mechanism for maintenance of mean arterial pressure and orthostatic tolerance in healthy subjects is beta adrenergic-induced tachycardia.

Comparative study of the venoms from three species of bees: effects on heart activity and blood.

PubMed

Hussein, A A; Nabil, Z I; Zalat, S M; Rakha, M K

2001-11-01

Crude venoms from three highly evolved aculeate species: Apis mellifera (highly social bees), Bombus morrisoni (eusocial bees), and Anthophora pauperata (solitary bees), were used for conducting this study to compare the effects of honey bee, bumble bee, and solitary bee venom on toad cardiac muscle activity. In addition, these venoms were tested on rat whole blood in order to determine their ability to induce red blood cell haemolysis. The main toxic effects on isolated toad heart were monitored by ECG after perfusion with different concentrations of each bee venom, and are represented as a decrease in the heart rate (HR) accompanied by an elongation in the P-R interval. A gradual and progressive increase in R-wave amplitude was also noted. Several electrocardiographic changes were noted 5-30 min after envenomation with any of the bee venoms. The mechanism of action of the three bee venoms was determined by direct application of atropine, nicotine, or verapamil to the isolated toad hearts. Comparison of the three venoms revealed that Anthophora pauperata venom is the most effective venom in inducing bradycardia, and it has the strongest negative dromotropic effect. Apis mellifera venom demonstrates the most positive inotropic effect of the three venoms. The effects of bee venom on the blood indices of erythrocyte osmotic fragility (EOF) and plasma albumin levels were studied after incubation of rat blood with each venom. It was noticed that RBCs decreased while Hb content, HCT, MCV, MCH, and MCHC increased, although this change did fluctuate and was not significant. A nonsignificant decrease in EOF was noted after 60 min with any of the venoms used. Incubation of rat whole blood with 1 microg/ml of any of the bee venom solutions revealed a highly significant decrease in plasma albumin levels. It can be concluded that venoms from the three species of bees we tested have negative chronotropic and dromotropic effects on isolated toad heart, with Anthophora pauperata being the most potent. In addition, the venoms have positive inotropic effects withApis mellifera being the most potent. The nonsignificant effects of venom on blood profiles and erythrocyte osmotic fragility, combined with the significant decrease in plasma albumin level suggest a protective effect of plasma albumin against bee venom induced toxicity to erythrocytes.

Geraniol blocks calcium and potassium channels in the mammalian myocardium: useful effects to treat arrhythmias.

PubMed

de Menezes-Filho, José Evaldo Rodrigues; Gondim, Antônio Nei Santana; Cruz, Jader Santos; de Souza, Américo Azevedo; Santos, José Nilson Andrade Dos; Conde-Garcia, Eduardo Antônio; de Sousa, Damião Pergentino; Santos, Michel Santana; de Oliveira, Evaleide Diniz; de Vasconcelos, Carla Maria Lins

2014-12-01

Geraniol is a monoterpene present in several essential oils, and it is known to have a plethora of pharmacological activities. In this study, we explored the contractile and electrophysiological properties of geraniol and its antiarrhythmic effects in the heart. The geraniol effects on atrial contractility, L-type Ca(2+) current, K(+) currents, action potential (AP) parameters, ECG profile and on the arrhythmia induced by ouabain were evaluated. In the atrium, geraniol reduced the contractile force (~98%, EC = 1,510 ± 160 μM) and diminished the positive inotropism of CaCl2 and BAY K8644. In cardiomyocytes, the IC a,L was reduced by 50.7% (n = 5) after perfusion with 300 μM geraniol. Moreover, geraniol prolonged the AP duration (APD) measured at 50% (n = 5) after repolarization, without changing the resting potential. The increased APD could be attributed to the blockade of the transient outward K(+) current (Ito ) (59.7%, n = 4), the non-inactivation K(+) current (Iss ) (39.2%, n = 4) and the inward rectifier K(+) current (IK 1 ) (33.7%, n = 4). In isolated hearts, geraniol increased PRi and QTi without affecting the QRS complex (n = 6), and it reduced both the left ventricular pressure (83%) and heart rate (16.5%). Geraniol delayed the time to onset of ouabain-induced arrhythmias by 128%, preventing 30% of the increase in resting tension (n = 6). Geraniol exerts its negative inotropic and chronotropic responses in the heart by decreasing both L-type Ca(2+) and voltage-gated K(+) currents, ultimately acting against ouabain-induced arrhythmias. © 2014 Nordic Association for the Publication of BCPT (former Nordic Pharmacological Society).

Cannabis, 1977.

PubMed

1978-10-01

Recent advances in development of immunoassay methods for marijuana constituents in body fluids provide a rapid means of detection for forensic purposes and a useful research tool for accurate quantitation of dose-response relation. Therapeutic possibilities of cannabis, such as reduction in intraocular pressure and bronchodilatation, may stimulate development of synthetic cannabinoid derivatives that meet acceptable standards of safety and effiicacy for treatment of glaucoma and asthma. Cannabis use may have harmful short- and long-term impacts on health. Potentially serious short-term effects include predisposition to angina during exercise in patients with coronary artery disease. Even in healthy subjects, marijuana smoking decreases peak exercise performance, possibly because of its chronotropic effect with achievement of maximum heart rate at reduced work loads. Although no conclusive evidence exists for long-term biologic consequences of chronic cannabis use, preliminary evidence, suggesting impairment in pulmonary function and immune responses, requires further investigation with large-scale epidemiologic studies.

Caffeine: cognitive and physical performance enhancer or psychoactive drug?

PubMed

Cappelletti, Simone; Piacentino, Daria; Daria, Piacentino; Sani, Gabriele; Aromatario, Mariarosaria

2015-01-01

Caffeine use is increasing worldwide. The underlying motivations are mainly concentration and memory enhancement and physical performance improvement. Coffee and caffeine-containing products affect the cardiovascular system, with their positive inotropic and chronotropic effects, and the central nervous system, with their locomotor activity stimulation and anxiogenic-like effects. Thus, it is of interest to examine whether these effects could be detrimental for health. Furthermore, caffeine abuse and dependence are becoming more and more common and can lead to caffeine intoxication, which puts individuals at risk for premature and unnatural death. The present review summarizes the main findings concerning caffeine's mechanisms of action (focusing on adenosine antagonism, intracellular calcium mobilization, and phosphodiesterases inhibition), use, abuse, dependence, intoxication, and lethal effects. It also suggests that the concepts of toxic and lethal doses are relative, since doses below the toxic and/or lethal range may play a causal role in intoxication or death. This could be due to caffeine's interaction with other substances or to the individuals' preexisting metabolism alterations or diseases.

Caffeine: Cognitive and Physical Performance Enhancer or Psychoactive Drug?

PubMed Central

Cappelletti, Simone; Daria, Piacentino; Sani, Gabriele; Aromatario, Mariarosaria

2015-01-01

Caffeine use is increasing worldwide. The underlying motivations are mainly concentration and memory enhancement and physical performance improvement. Coffee and caffeine-containing products affect the cardiovascular system, with their positive inotropic and chronotropic effects, and the central nervous system, with their locomotor activity stimulation and anxiogenic-like effects. Thus, it is of interest to examine whether these effects could be detrimental for health. Furthermore, caffeine abuse and dependence are becoming more and more common and can lead to caffeine intoxication, which puts individuals at risk for premature and unnatural death. The present review summarizes the main findings concerning caffeine’s mechanisms of action (focusing on adenosine antagonism, intracellular calcium mobilization, and phosphodiesterases inhibition), use, abuse, dependence, intoxication, and lethal effects. It also suggests that the concepts of toxic and lethal doses are relative, since doses below the toxic and/or lethal range may play a causal role in intoxication or death. This could be due to caffeine’s interaction with other substances or to the individuals' preexisting metabolism alterations or diseases. PMID:26074744

Heart Rate Response to a Timed Walk & Cardiovascular Outcomes in Older Adults: The Cardiovascular Health Study

PubMed Central

Girotra, Saket; Kitzman, Dalane W.; Kop, Willem J.; Stein, Phyllis K.; Gottdiener, John S.; Mukamal, Kenneth J.

2012-01-01

OBJECTIVES To determine the relationship between heart rate response during low-grade physical exertion (six-minute walk) with mortality and adverse cardiovascular outcomes in the elderly. METHODS Participants in the Cardiovascular Health Study, who completed a six-minute walk test, were included. We used delta heart rate (difference between post-walk heart rate and resting heart rate) as a measure of chronotropic response and examined its association with 1) all-cause mortality and 2) incident coronary heart disease (CHD) event, using multivariable Cox regression models. RESULTS We included 2224 participants (mean age 77±4 years; 60% women, 85% white). The average delta heart rate was 26 beats/min. Participants in the lowest tertile of delta heart rate (<20 beats/min) had higher risk-adjusted mortality (hazard ratio [HR] 1.18; 95% confidence interval [CI][1.00, 1.40]) and incident CHD (HR 1.37; 95% CI[1.05, 1.78]) compared to subjects in the highest tertile (≥30 beats/min), with a significant linear trend across tertiles (P for trend <0.05 for both outcomes). This relationship was not significant after adjustment for distance walked. CONCLUSION Impaired chronotropic response during six-minute walk test was associated with an increased risk of mortality and incident CHD among the elderly. This association was attenuated after adjusting for distance walked. PMID:22722364

Abnormal heart rate recovery and chronotropic incompetence on exercise in chronic obstructive pulmonary disease.

PubMed

Gupta, Mansi; Bansal, Vishal; Chhabra, Sunil K

2013-08-01

Chronotropic incompetence (CI; failure to reach the targeted heart rate (HR) on exercise) and a delayed HR recovery (HRR; ≤12 beats decline within the first minute after cessation) reflect autonomic dysfunction (AD) and predict adverse cardiac prognosis. As chronic obstructive pulmonary disease (COPD) is known to be associated with AD, we hypothesized that these patients may manifest these responses on exercise. The prevalence and predictors of these responses in COPD and their association with its severity have not been evaluated. Normoxemic, stable male patients with COPD (n = 39) and 11 healthy controls underwent lung function testing and incremental leg ergometry. HR responses were monitored during exercise and recovery to compute the HRR and CI. Of all the patients, 33 (84.6%) had at least one of the two exercise responses as abnormal, with the majority (23, 58.9%) having both an abnormal HRR and CI. The frequency of abnormal responses increased with increasing Global Initiative for Chronic Obstructive Lung Disease stage and body mass index, airflow obstruction, dyspnoea and exercise capacity index. After adjusting for smoking history and post-bronchodilator forced expiratory volume in 1 second, only a reduced diffusion capacity for carbon monoxide predicted abnormal HRR, though weakly. We concluded that abnormal HRR and CI are common in patients with COPD. These responses are observed with increasing frequency as the severity of disease increases.

RGS6, but not RGS4, is the dominant regulator of G protein signaling (RGS) modulator of the parasympathetic regulation of mouse heart rate.

PubMed

Wydeven, Nicole; Posokhova, Ekaterina; Xia, Zhilian; Martemyanov, Kirill A; Wickman, Kevin

2014-01-24

Parasympathetic activity decreases heart rate (HR) by inhibiting pacemaker cells in the sinoatrial node (SAN). Dysregulation of parasympathetic influence has been linked to sinus node dysfunction and arrhythmia. RGS (regulator of G protein signaling) proteins are negative modulators of the parasympathetic regulation of HR and the prototypical M2 muscarinic receptor (M2R)-dependent signaling pathway in the SAN that involves the muscarinic-gated atrial K(+) channel IKACh. Both RGS4 and RGS6-Gβ5 have been implicated in these processes. Here, we used Rgs4(-/-), Rgs6(-/-), and Rgs4(-/-):Rgs6(-/-) mice to compare the relative influence of RGS4 and RGS6 on parasympathetic regulation of HR and M2R-IKACh-dependent signaling in the SAN. In retrogradely perfused hearts, ablation of RGS6, but not RGS4, correlated with decreased resting HR, increased heart rate variability, and enhanced sensitivity to the negative chronotropic effects of the muscarinic agonist carbachol. Similarly, loss of RGS6, but not RGS4, correlated with enhanced sensitivity of the M2R-IKACh signaling pathway in SAN cells to carbachol and a significant slowing of M2R-IKACh deactivation rate. Surprisingly, concurrent genetic ablation of RGS4 partially rescued some deficits observed in Rgs6(-/-) mice. These findings, together with those from an acute pharmacologic approach in SAN cells from Rgs6(-/-) and Gβ5(-/-) mice, suggest that the partial rescue of phenotypes in Rgs4(-/-):Rgs6(-/-) mice is attributable to another R7 RGS protein whose influence on M2R-IKACh signaling is masked by RGS4. Thus, RGS6-Gβ5, but not RGS4, is the primary RGS modulator of parasympathetic HR regulation and SAN M2R-IKACh signaling in mice.

Zolpidem efficacy and safety in disorders of consciousness.

PubMed

Machado, Calixto; Estévez, Mario; Rodriguez-Rojas, Rafael

2018-01-01

Sutton and Clauss presented a detailed review about the effectiveness of zolpidem, discussing recoveries from brain damage due to strokes, trauma and hypoxia. A significant finding has been the unexpected and paradoxical increment of brain activity in vegetative state/unresponsive wakefulness syndrome (VS/UWS). On the contrary, zolpidem is considered one of the best sleep inducers in normal subjects. We have studied series of VS/UWS cases after zolpidem intake. We have demonstrated EEG activation, increment of BOLD signal in different brain regions, and an autonomic influence, mainly characterized by a vagolytic chronotropic effect without a significant increment of the vasomotor sympathetic tone. As this autonomic imbalance might induce cardio- circulatory complications, which we didn't find in any of our patients, we suggest developing future trials under control of physiological indices by bedside monitoring. However, considering that the paradoxical arousing zolpidem effect might be certainly related to brain function improvement, we agree with Sutton and Clauss that future multicentre and multinational clinical trials should be developed, but under control of physiological indices.

Comparative study between atropine and hyoscine-N-butylbromide for reversal of detomidine induced bradycardia in horses.

PubMed

Pimenta, E L M; Teixeira Neto, F J; Sá, P A; Pignaton, W; Garofalo, N A

2011-05-01

Bradycardia may be implicated as a cause of cardiovascular instability during anaesthesia. Hyoscine would induce positive chronotropism of shorter duration than atropine, without adversely impairing intestinal motility in detomidine sedated horses. Ten minutes after detomidine (0.02 mg/kg bwt, i.v.), physiological saline (control), atropine (0.02 mg/kg bwt) or hyoscine (0.2 mg/kg bwt) were randomly administered i.v. to 6 horses, allowing one week intervals between treatments. Investigators blinded to the treatments monitored cardiopulmonary data and intestinal auscultation for 90 min and 24 h after detomidine, respectively. Gastrointestinal transit was assessed for 96 h via chromium detection in dry faeces. Detomidine significantly decreased heart rate (HR) and cardiac index (CI) from baseline for 30 and 60 min, respectively (control). Mean ± s.d. HR increased significantly 5 min after atropine (79 ± 5 beats/min) and hyoscine (75 ± 8 beats/min). After this time, HR was significantly higher after atropine in comparison to other treatments, while hyoscine resulted in intermediate values (lower than atropine but higher than controls). Hyoscine and atropine resulted in significantly higher CI than controls for 5 and 20 min, respectively; but this effect coincided with significant hypertension (mean arterial pressures >180 mmHg). Auscultation scores decreased from baseline in all treatments. Time to return to auscultation scores ≥12 (medians) did not differ between hyoscine (4 h) and controls (4 h) but atropine resulted in significantly longer time (10 h). Atropine induced colic in one horse. Gastrointestinal transit times did not differ between treatments. Hyoscine is a shorter acting positive chronotropic agent than atropine, but does not potentiate the impairment in intestinal motility induced by detomidine. Because of severe hypertension, routine use of anticholinergics combined with detomidine is not recommended. Hyoscine may represent an alternative to atropine for treating bradycardia. © 2010 EVJ Ltd.

AHR-16303B, a novel antagonist of 5-HT2 receptors and voltage-sensitive calcium channels

DOE Office of Scientific and Technical Information (OSTI.GOV)

Barrett, R.J.; Appell, K.C.; Kilpatrick, B.F.

1991-01-01

In vivo and in vitro methods were used to characterize AHR-16303B, a novel compound with antagonistic action at 5-HT2 receptors and voltage-sensitive calcium channels. The 5-HT2 receptor-antagonistic properties of AHR-16303B were demonstrated by inhibition of (a) (3H)ketanserin binding to rat cerebral cortical membranes (IC50 = 165 nM); (b) 5-hydroxytryptamine (5-HT)-induced foot edema in rats (minimum effective dose, (MED) = 0.32 mg/kg orally, p.o.); (c) 5-HT-induced vasopressor responses in spontaneously hypertensive rats (SHR) (ID50 = 0.18 mg/kg intravenously (i.v.), 1.8 mg/kg p.o.), (d) 5-HT-induced antidiuresis in rats (MED = 1 mg/kg p.o.), and (e) platelet aggregation induced by 5-HT + ADPmore » (IC50 = 1.5 mM). The calcium antagonist properties of AHR-16303B were demonstrated by inhibition of (a) (3H)nimodipine binding to voltage-sensitive calcium channels on rabbit skeletal muscle membranes (IC50 = 15 nM), (b) KCl-stimulated calcium flux into cultured PC12 cells (IC50 = 81 nM), and (c) CaCl2-induced contractions of rabbit thoracic aortic strips (pA2 = 8.84). AHR-16303B had little or no effect on binding of radioligands to dopamine2 (DA2) alpha 1, alpha 2, H1, 5-HT1 alpha, beta 2, muscarinic M1, or sigma opioid receptors; had no effect on 5-HT3 receptor-mediated vagal bradycardia; and had only minor negative inotropic, chronotropic, and dromotropic effects on isolated guinea pig atria. In conscious SHR, 30 mg/kg p.o. AHR-16303B completely prevented the vasopressor responses to i.v. 5-HT, and decreased blood pressure (BP) by 24% 3 h after dosing.« less

Unusual presentation of phaeochromocytoma.

PubMed

Hope, D C D; Palan, J M

2016-05-10

A 44-year-old woman, with a background of heart, lung and renal transplantation secondary to cystic fibrosis and type 1 diabetes, presented with tachycardia, hyperglycaemia, nausea and vomiting. She was initially managed for diabetic ketoacidosis with severe dehydration. However, persistent episodic hypertension and tachycardia led the investigating team to identify significantly raised urinary metanephrines and a left-sided adrenal mass; Iodine-123-meta-iodobenzylguanidine single photon emission computer tomography scan (MIBG SPECT/CT) showed avid uptake of tracer, confirming a left-sided phaeochromocytoma. She was started on medical management and is awaiting an elective laparoscopic procedure. This case describes the presentation of a unilateral phaeochromocytoma as ketoacidosis in a patient with type 1 diabetes with no other apparent precipitant. This highlights the metabolic counter-regulatory effect of excess catecholamines in addition to the inotropic/chronotropic effects that are associated with this adrenal tumour. Recognition of atypical signs and symptoms may point towards an atypical precipitant of diabetic ketoacidosis-a medical emergency presenting to front-line clinicians. 2016 BMJ Publishing Group Ltd.

Unusual presentation of phaeochromocytoma

PubMed Central

Hope, D C D; Palan, J M

2016-01-01

A 44-year-old woman, with a background of heart, lung and renal transplantation secondary to cystic fibrosis and type 1 diabetes, presented with tachycardia, hyperglycaemia, nausea and vomiting. She was initially managed for diabetic ketoacidosis with severe dehydration. However, persistent episodic hypertension and tachycardia led the investigating team to identify significantly raised urinary metanephrines and a left-sided adrenal mass; Iodine-123-meta-iodobenzylguanidine single photon emission computer tomography scan (MIBG SPECT/CT) showed avid uptake of tracer, confirming a left-sided phaeochromocytoma. She was started on medical management and is awaiting an elective laparoscopic procedure. This case describes the presentation of a unilateral phaeochromocytoma as ketoacidosis in a patient with type 1 diabetes with no other apparent precipitant. This highlights the metabolic counter-regulatory effect of excess catecholamines in addition to the inotropic/chronotropic effects that are associated with this adrenal tumour. Recognition of atypical signs and symptoms may point towards an atypical precipitant of diabetic ketoacidosis—a medical emergency presenting to front-line clinicians. PMID:27166010

Efficacy of the saponin component of Impatiens capensis Meerb.in preventing urushiol-induced contact dermatitis.

PubMed

Motz, Vicki A; Bowers, Christopher P; Kneubehl, Alexander R; Lendrum, Elizabeth C; Young, Linda M; Kinder, David H

2015-03-13

Many different tribes of American Indians used jewelweed, Impatiens capensis Meerb, as a plant mash to reduce development of poison ivy dermatitis. Saponins are a natural soapy constituent found within plants. A 2012 study suggested that saponins may be present in jewelweed which could be responsible for its efficacy in preventing rash development following contact with Toxicodendron radicans (L.) Kuntze (poison ivy). This study validated this hypothesis and demonstrated additional biological activity of the jewelweed saponin containing extract. Fresh I. capensis leaves were extracted with methanol and further partitioned between ethyl acetate and water, with a final separation between water and n-butanol, to obtain a saponin containing extract. The presence of saponins in the extract was demonstrated by the observation of foaming and using a vanillin colorimetric assay for total saponins. Efficacy of the saponin containing extracts in rash reduction was tested by brushing poison ivy (PI) onto the forearms of volunteers (N=23) in six locations and treating these PI exposed areas with distilled water (control), saponin containing extracts, fresh plant mashes, and soaps made with and without plant extracts. Saponin containing extracts were further tested for biological activity against both gram negative and gram positive bacteria and against cancer cell lines A-375, HT-29, and MCF-7. Additionally, because saponins have been shown to have a stimulatory effect in cardiac muscle 2 µl saponin extract was applied superficially to black worms, Lumbriculus variegatus (N=5). Both saponin containing extracts and all soaps tested were effective in reducing poison ivy dermatitis; thus, saponin content correlates with PI rash prevention. No apparent antibiosis was observed against any bacteria tested; however, dose response cytotoxicity was documented against MCF-7 breast cancer cells and cytostatic activity was seen against the HT-29 colon cancer cell lines. Lumbriculus variegatus exhibited a 138% increase in heart rate over baseline rate five minutes post treatment implying a possible positive chronotropic effect. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Inhibition of the sympathetic nervous system by a series of heterocyclic congeners of dopamine.

PubMed

Sharabi, F M; Long, J P; Cannon, J G; Hatheway, G J

1976-12-01

A series of heterocyclic congeners of dopamine (GJH-series) with different positions of phenolic oxygens and with the possibility of cis and trans isomerism at the 4a-10b ring juncture was evaluated in vitro and in vivo for dopaminergic activity. Two compounds, GJH-166 and GJH-171, were found to suppress the positive chronotropic response induced by stimulation of the right cardioaccelerator nerves. These effects were antagonized by haloperidol. GJH-166, in doses as low as 9.5 x 10(-4) mugmol/kg reduced the resting heart rate in cats anesthetized with alpha-chloralose. GJH-166 and GJH-171 antagonized pressor responses induced by bilateral carotid occlusion and stimulation of the central stump of the sciatic nerve. The results outlined in this manuscript support the hypothesis that the extended conformation of the dihydroxyhenylethylamine moiety of dopamine with a trans isomeric form is favorable for dopaminergic agonist activity.

The autonomic nervous system and cardiac GLP-1 receptors control heart rate in mice.

PubMed

Baggio, Laurie L; Ussher, John R; McLean, Brent A; Cao, Xiemin; Kabir, M Golam; Mulvihill, Erin E; Mighiu, Alexandra S; Zhang, Hangjun; Ludwig, Andreas; Seeley, Randy J; Heximer, Scott P; Drucker, Daniel J

2017-11-01

Glucagon-like peptide-1 (GLP-1) is secreted from enteroendocrine cells and exerts a broad number of metabolic actions through activation of a single GLP-1 receptor (GLP-1R). The cardiovascular actions of GLP-1 have garnered increasing attention as GLP-1R agonists are used to treat human subjects with diabetes and obesity that may be at increased risk for development of heart disease. Here we studied mechanisms linking GLP-1R activation to control of heart rate (HR) in mice. The actions of GLP-1R agonists were examined on the control of HR in wild type mice (WT) and in mice with cardiomyocyte-selective disruption of the GLP-1R (Glp1r CM-/- ). Complimentary studies examined the effects of GLP-1R agonists in mice co-administered propranolol or atropine. The direct effects of GLP-1R agonism on HR and ventricular developed pressure were examined in isolated perfused mouse hearts ex vivo, and atrial depolarization was quantified in mouse hearts following direct application of liraglutide to perfused atrial preparations ex vivo. Doses of liraglutide and lixisenatide that were equipotent for acute glucose control rapidly increased HR in WT and Glp1r CM-/- mice in vivo. The actions of liraglutide to increase HR were more sustained relative to lixisenatide, and diminished in Glp1r CM-/- mice. The acute chronotropic actions of GLP-1R agonists were attenuated by propranolol but not atropine. Neither native GLP-1 nor lixisenatide increased HR or developed pressure in perfused hearts ex vivo. Moreover, liraglutide had no direct effect on sinoatrial node firing rate in mouse atrial preparations ex vivo. Despite co-localization of HCN4 and GLP-1R in primate hearts, HCN4-directed Cre expression did not attenuate levels of Glp1r mRNA transcripts, but did reduce atrial Gcgr expression in the mouse heart. GLP-1R agonists increase HR through multiple mechanisms, including regulation of autonomic nervous system function, and activation of the atrial GLP-1R. Surprisingly, the isolated atrial GLP-1R does not transduce a direct chronotropic effect following exposure to GLP-1R agonists in the intact heart, or isolated atrium, ex vivo. Hence, cardiac GLP-1R circuits controlling HR require neural inputs and do not function in a heart-autonomous manner. Copyright © 2017 The Authors. Published by Elsevier GmbH.. All rights reserved.

Effects of denopamine (TA-064), a new positive inotropic agent, on myocardial oxygen consumption and left ventricular dimension in anesthetized dogs.

PubMed

Ikeo, T; Nagao, T

1985-10-01

We compared the effects of denopamine (TA-064) and isoproterenol on hemodynamics, myocardial oxygen consumption and the left ventricular (LV) dimension in halothane-N2O anesthetized dogs. Denopamine (0.25-1 micrograms/kg/min, i.v., infusion X 15 min) produced a maximum increase in LV dp/dtmax by 64% of the control, without affecting aortic pressure significantly. Doses of isoproterenol (0.01-0.04 micrograms/kg/min, i.v., infusion X 15 min) were selected to produce a positive inotropic action similar to that of denopamine. Denopamine produced significantly less increasing effects in heart rate, cardiac output and myocardial oxygen consumption and had more reducing effects in LV internal diameter than isoproterenol, while isoproterenol tended to produce a more potent increase in coronary blood flow, but a smaller decrease in LV end-diastolic pressure than denopamine. PQ interval was similarly reduced. Denopamine caused no substantial increase in myocardial oxygen consumption at a lower dose, at which LV dp/dtmax was significantly increased. A weak effect of denopamine on myocardial oxygen consumption may result partly from a weak positive chronotropic effect and partly from a reduction of preload and cardiac size.

In vivo antimuscarinic actions of the third generation antihistaminergic agent, desloratadine.

PubMed

Howell, G; West, L; Jenkins, C; Lineberry, B; Yokum, D; Rockhold, R

2005-08-18

Muscarinic receptor mediated adverse effects, such as sedation and xerostomia, significantly hinder the therapeutic usefulness of first generation antihistamines. Therefore, second and third generation antihistamines which effectively antagonize the H1 receptor without significant affinity for muscarinic receptors have been developed. However, both in vitro and in vivo experimentation indicates that the third generation antihistamine, desloratadine, antagonizes muscarinic receptors. To fully examine the in vivo antimuscarinic efficacy of desloratadine, two murine and two rat models were utilized. The murine models sought to determine the efficacy of desloratadine to antagonize muscarinic agonist induced salivation, lacrimation, and tremor. Desloratadine's effect on the cardiovascular system was explored in both rodent models. In the pithed rat, both desloratadine (1.0 mg/kg, i.v.) and the muscarinic M2 selective antagonist, methoctramine (0.5 mg/kg, i.v.), inhibited negative inotropic (left ventricular dP/dt) effects caused by oxotremorine, a nonselective muscarinic agonist (p < 0.05). Negative chronotropic effects caused by oxotremorine were inhibited by desloratadine, methoctramine, and the muscarinic M3 selective antagonist, 4-DAMP (1.0 mg/kg, i.v.). A late positive inotropic event observed after the initial decrease was inhibited by all three test compounds with desloratadine and 4-DAMP being the most efficacious. In the conscious animal, inhibition of baroreflex-mediated bradycardia was evaluated. Unlike atropine (0.5 mg/kg, i.v.), desloratadine did not alter this bradycardia. The antimuscarinic action of desloratadine on salivation, lacrimation, and tremor was also explored. In urethane-anesthetized (1.5 g/kg, i.p.) male ICR mice (25-35 g) desloratadine (1.0, 5.0 mg/kg) did not inhibit oxotremorine-induced (0.5 mg/kg, s.c.) salivation, unlike atropine (0.5 mg/kg) and 4-DAMP (1.0 mg/kg). In conscious mice, desloratadine failed to inhibit oxotremorine-induced (0.5 mg/kg, s.c.) salivation, lacrimation, and tremor. However, desloratadine did inhibit oxotremorine-induced tremor in phenylephrine pretreated animals. The presented data demonstrate that the third generation antihistamine, desloratadine, does not significantly antagonize peripheral muscarinic receptors mediating salivation and lacrimation, therefore, xerostomia and dry eyes should not be observed with therapeutic use of desloratadine. Our data also indicate when administered to a patient with a compromised blood-brain barrier, desloratadine may cause sedation. Patients with compromised cardiovascular systems should be closely monitored when administered desloratadine based on our results that desloratadine has the ability to interfere with normal cardiovascular function mediated by muscarinic receptors.

In vivo antimuscarinic actions of the third generation antihistaminergic agent, desloratadine

PubMed Central

Howell, G; West, L; Jenkins, C; Lineberry, B; Yokum, D; Rockhold, R

2005-01-01

Background Muscarinic receptor mediated adverse effects, such as sedation and xerostomia, significantly hinder the therapeutic usefulness of first generation antihistamines. Therefore, second and third generation antihistamines which effectively antagonize the H1 receptor without significant affinity for muscarinic receptors have been developed. However, both in vitro and in vivo experimentation indicates that the third generation antihistamine, desloratadine, antagonizes muscarinic receptors. To fully examine the in vivo antimuscarinic efficacy of desloratadine, two murine and two rat models were utilized. The murine models sought to determine the efficacy of desloratadine to antagonize muscarinic agonist induced salivation, lacrimation, and tremor. Desloratadine's effect on the cardiovascular system was explored in both rodent models. Results In the pithed rat, both desloratadine (1.0 mg/kg, i.v.) and the muscarinic M2 selective antagonist, methoctramine (0.5 mg/kg, i.v.), inhibited negative inotropic (left ventricular dP/dt) effects caused by oxotremorine, a nonselective muscarinic agonist (p < 0.05). Negative chronotropic effects caused by oxotremorine were inhibited by desloratadine, methoctramine, and the muscarinic M3 selective antagonist, 4-DAMP (1.0 mg/kg, i.v.). A late positive inotropic event observed after the initial decrease was inhibited by all three test compounds with desloratadine and 4-DAMP being the most efficacious. In the conscious animal, inhibition of baroreflex-mediated bradycardia was evaluated. Unlike atropine (0.5 mg/kg, i.v.), desloratadine did not alter this bradycardia. The antimuscarinic action of desloratadine on salivation, lacrimation, and tremor was also explored. In urethane-anesthetized (1.5 g/kg, i.p.) male ICR mice (25–35 g) desloratadine (1.0, 5.0 mg/kg) did not inhibit oxotremorine-induced (0.5 mg/kg, s.c.) salivation, unlike atropine (0.5 mg/kg) and 4-DAMP (1.0 mg/kg). In conscious mice, desloratadine failed to inhibit oxotremorine-induced (0.5 mg/kg, s.c.) salivation, lacrimation, and tremor. However, desloratadine did inhibit oxotremorine-induced tremor in phenylephrine pretreated animals. Conclusion The presented data demonstrate that the third generation antihistamine, desloratadine, does not significantly antagonize peripheral muscarinic receptors mediating salivation and lacrimation, therefore, xerostomia and dry eyes should not be observed with therapeutic use of desloratadine. Our data also indicate when administered to a patient with a compromised blood-brain barrier, desloratadine may cause sedation. Patients with compromised cardiovascular systems should be closely monitored when administered desloratadine based on our results that desloratadine has the ability to interfere with normal cardiovascular function mediated by muscarinic receptors. PMID:16109168

Effects of renal sympathetic denervation on exercise blood pressure, heart rate, and capacity in patients with resistant hypertension.

PubMed

Ewen, Sebastian; Mahfoud, Felix; Linz, Dominik; Pöss, Janine; Cremers, Bodo; Kindermann, Ingrid; Laufs, Ulrich; Ukena, Christian; Böhm, Michael

2014-04-01

Renal denervation reduces office blood pressure in patients with resistant hypertension. This study investigated the effects of renal denervation on blood pressure, heart rate, and chronotropic index at rest, during exercise, and at recovery in 60 patients (renal denervation group=50, control group=10) with resistant hypertension using a standardized bicycle exercise test protocol performed 6 and 12 months after renal denervation. After renal denervation, exercise blood pressure at rest was reduced from 158±3/90±2 to 141±3/84±4 mm Hg (P<0.001 for systolic blood pressure/P=0.007 for diastolic blood pressure) after 6 months and 139±3/83±4 mm Hg (P<0.001/P=0.022) after 12 months. Exercise blood pressure tended to be lower at all stages of exercise at 6- and 12-month follow-up in patients undergoing renal denervation, although reaching statistical significance only at mild-to-moderate exercise levels (75-100 W). At recovery after 1 minute, blood pressure decreased from 201±4/95±2 to 177±4/88±2 (P<0.001/P=0.066) and 188±6/86±2 mm Hg (P=0.059/P=0.01) after 6 and 12 months, respectively. Heart rate was reduced after renal denervation from 71±3 bpm at rest, 128±5 bpm at maximum workload, and 96±5 bpm at recovery after 1 minute to 66±2 (P<0.001), 115±5 (P=0.107), and 89±3 bpm (P=0.008) after 6 months and to 69±3 (P=0.092), 122±7 (P=0.01), and 93±4 bpm (P=0.032) after 12 months. Mean exercise time increased from 6.59±0.33 to 8.4±0.32 (P<0.001) and 9.0±0.41 minutes (P=0.008), and mean workload increased from 93±2 to 100±2 (P<0.001) and 101±3 W (P=0.007) at 6- and 12-month follow-up, respectively. No changes were observed in the control group. In conclusion, renal denervation reduced blood pressure and heart rate during exercise, improved mean workload, and increased exercise time without impairing chronotropic competence.

Size, shape, and stamina: the impact of left ventricular geometry on exercise capacity.

PubMed

Lam, Carolyn S P; Grewal, Jasmine; Borlaug, Barry A; Ommen, Steve R; Kane, Garvan C; McCully, Robert B; Pellikka, Patricia A

2010-05-01

Although several studies have examined the cardiac functional determinants of exercise capacity, few have investigated the effects of structural remodeling. The current study evaluated the association between cardiac geometry and exercise capacity. Subjects with ejection fraction > or = 50% and no valvular disease, myocardial ischemia, or arrhythmias were identified from a large prospective exercise echocardiography database. Left ventricular mass index and relative wall thickness were used to classify geometry into normal, concentric remodeling, eccentric hypertrophy, and concentric hypertrophy. All of the subjects underwent symptom-limited treadmill exercise according to standard Bruce protocol. Maximal exercise tolerance was measured in metabolic equivalents. Of 366 (60+/-14 years; 57% male) subjects, 166 (45%) had normal geometry, 106 (29%) had concentric remodeling, 40 (11%) had eccentric hypertrophy, and 54 (15%) had concentric hypertrophy. Geometry was related to exercise capacity: in descending order, the maximum achieved metabolic equivalents were 9.9+/-2.8 in normal, 8.9+/-2.6 in concentric remodeling, 8.6+/-3.1 in eccentric hypertrophy, and 8.0+/-2.7 in concentric hypertrophy (all P<0.02 versus normal). Left ventricular mass index and relative wall thickness were negatively correlated with exercise tolerance in metabolic equivalents (r=-0.14; P=0.009 and r=-0.21; P<0.001, respectively). Augmentation of heart rate and ejection fraction with exercise were blunted in concentric hypertrophy compared with normal, even after adjusting for medications. In conclusion, the pattern of ventricular remodeling is related to exercise capacity among low-risk adults. Subjects with concentric hypertrophy display the greatest limitation, and this is related to reduced systolic and chronotropic reserve. Reverse remodeling strategies may prevent or treat functional decline in patients with structural heart disease.

Size, Shape and Stamina: The Impact of Left Ventricular Geometry on Exercise Capacity

PubMed Central

Lam, Carolyn S.P.; Grewal, Jasmine; Borlaug, Barry A.; Ommen, Steve R.; Kane, Garvan C.; McCully, Robert B.; Pellikka, Patricia A.

2010-01-01

While several studies have examined the cardiac functional determinants of exercise capacity, few have investigated the effects of structural remodeling. The current study evaluated the association between cardiac geometry and exercise capacity. Subjects with ejection fraction ≥ 50% and no valvular disease, myocardial ischemia or arrhythmias were identified from a large prospective exercise echocardiography database. Left ventricular mass index and relative wall thickness were used to classify geometry into normal, concentric remodeling, eccentric hypertrophy and concentric hypertrophy. All subjects underwent symptom-limited treadmill exercise according to standard Bruce protocol. Maximal exercise tolerance was measured in metabolic equivalents. Of 366 (60±14 years; 57% male) subjects, 166(45%) had normal geometry, 106(29%) had concentric remodeling, 40(11%) had eccentric hypertrophy and 54(15%) had concentric hypertrophy. Geometry was related to exercise capacity: in descending order, the maximum achieved metabolic equivalents was 9.9±2.8 in normal, 8.9±2.6 in concentric remodeling, 8.6±3.1 in eccentric hypertrophy and 8.0±2.7 in concentric hypertrophy (all p<0.02 vs normal). Left ventricular mass index and relative wall thickness were negatively correlated with exercise tolerance in metabolic equivalents (r= -0.14; p=0.009 and r= -0.21; p<0.001, respectively). Augmentation of heart rate and ejection fraction with exercise were blunted in concentric hypertrophy compared to normal, even after adjusting for medications. In conclusion, the pattern of ventricular remodeling is related to exercise capacity among low-risk adults. Subjects with concentric hypertrophy display the greatest limitation and this is related to reduced systolic and chronotropic reserve. Reverse remodeling strategies may prevent or treat functional decline in patients with structural heart disease. PMID:20215563

Exercise heart rate gradient: a novel index to predict all-cause mortality.

PubMed

Duarte, Carlos Vieira; Myers, Jonathan; de Araújo, Claudio Gil Soares

2015-05-01

Although substantial evidence relates reduced exercise heart rate (HR) reserve and recovery to a higher risk of all-cause mortality, a combined indicator of these variables has not been explored. Our aim was to combine HR reserve and recovery into a single index and to assess its utility to predict all-cause mortality. Retrospective cohort analysis. Participants were 1476 subjects (937 males) aged between 41 and 79 years who completed a maximal cycle cardiopulmonary exercise test while not using medication with negative chronotropic effects or having an implantable cardiac pacemaker. HR reserve (HR maximum - HR resting) and recovery (HR maximum - HR at 1-min post exercise) were calculated and divided into quintiles. Quintile rankings were summed yielding an exercise HR gradient (EHRG) ranging from 2 to 10, reflecting the magnitude of on- and off-HR transients to exercise. Survival analyses were undertaken using EHRG scores and HR reserve and recovery in the lowest quintiles (Q1). During a mean follow up of 7.3 years, 44 participants died (3.1%). There was an inverse trend for EHRG scores and death rate (p < 0.05) that increased from 1.2% to 13.5%, respectively, for scores 10 and 2. An EHRG score of 2 was a better predictor of all-cause mortality than either Q1 for HR reserve (<80 bpm) or HR recovery alone (<27 bpm): age-adjusted hazard ratios: 3.53 (p = 0.011), 2.52 (p < 0.05), and 2.57 (p < 0.05), respectively. EHRG, a novel index combining HR reserve and HR recovery, is a better indicator of mortality risk than either response alone. © The European Society of Cardiology 2014 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav.

Lymphatic Muscle Cells in Rat Mesenteric Lymphatic Vessels of Various Ages

PubMed Central

Bridenbaugh, Eric A.; Nizamutdinova, Irina Tsoy; Jupiter, Daniel; Nagai, Takashi; Thangaswamy, Sangeetha; Chatterjee, Victor

2013-01-01

Abstract Background Recent studies on aging-associated changes in mesenteric lymph flow in situ demonstrated predominance of the severe negative chronotropic effect of aging on the contractility of aged mesenteric lymphatic vessels (MLV). At the same time, contraction amplitude of the aged vessels was only slightly diminished by aging and can be rapidly stimulated within 5–15 minutes. However, the detailed quantitative evaluation of potential aging-associated changes in muscle cells investiture in MLV has never been performed. Methods and Results In this study we, for the first time, performed detailed evaluation of muscle cells investiture in MLV in reference to the position of lymphatic valve in different zones of lymphangion within various age groups (3-mo, 9-mo and 24-mo Fischer-344 rats). Using visual and quantitative analyses of the images of MLV immunohistochemically labeled for actin, we confirmed that the zones located close upstream (pre-valve zones) and above lymphatic valves (valve zones) possess the lowest investiture of lymphatic muscle cells. Most of the high muscle cells investiture zones exist downstream to the lymphatic valve (post-valve zones). The muscle cells investiture of these zones is not affected by aging, while pre-valve and valve zones demonstrate significant aging-associated decrease in muscle cells investiture. Conclusions The low muscle cells investiture zones in lymphatic vessels consist of predominantly longitudinally oriented muscle cells which are positioned in pre-valve and valve zones and connect adjacent lymphangions. These cells may provide important functional impact on the biomechanics of the lymphatic valve gating and electrical coupling between lymphangions, while their aging-associated changes may delimit adaptive reserves of aged lymphatic vessels. PMID:23531183

Cardiovascular consequences of sympathetic hyperactivity.

PubMed

Leenen, F H

1999-03-01

The sympathetic nervous system plays an integral role in many aspects of cardiovascular homeostasis. However, intermittent or chronic sympathetic hyperactivity can also initiate or accelerate cardiovascular pathology and provoke clinical events in the presence of cardiovascular disease. Both alpha- and beta-receptors mediate these responses. In the case of the heart, alpha- and beta- receptors contribute to ventricular arrhythmias and cardiac hypertrophy. Moreover, cardiac beta2-receptors mediate not only chronotropic and inotropic responses at the postsynaptic level, but also noradrenalin release at the presynaptic level. To block the adverse effects of sympathetic hyperactivity optimally, one would therefore need both alpha- and nonselective beta-receptor blockade. On the other hand, prevention or reversal of sympathetic hyperactivity at the central level appears to be an attractive alternative. Alpha2-agonists such as clonidine and alpha-methyldopa are clearly effective in this regard but are associated with side effects. More recent research indicates that in the central nervous systen (CNS) other classes such as dihydropyridines (eg, nifedipine) or angiotensin II type 1 receptor blockers (eg, losartan) also can decrease elevated sympathetic nerve activity. The therapeutic relevance of these CNS effects and differences between lipophilic and hydrophilic compounds provide intriguing new avenues for research in disorders such as hypertension and congestive heart failure.

Comparative hemodynamic effects of hypotension induced by diadenosine tetraphosphate (AP4A) and ATP in dogs.

PubMed

Takeda, Shohei; Inada, Yutaka; Fukui, Noriyuki; Tomaru, Teruaki

1997-03-01

ATP and diadenosine tetraphosphate (AP 4 A) have been shown to produce vasodilation mediated by P 1 - and P 2 -purinoceptor, respectively. The differing mechanisms involved in this vasodilating activity may induce different systemic hemodynamic changes. We compared the hemodynamic effects of AP 4 A-induced hypotension with those induced by ATP. Fourteen mongrel dogs were anesthetized with 0.87% halothane in oxygen (1 MAC). After the baseline period, mean arterial pressure was reduced to 60 mmHg for 60 min by the infusion of AP 4 A or ATP. The ATP- and AP 4 A-induced hypotension resulted in a maximum reduction in systemic vascular resistance of 43% and 46%, respectively (P<0.01), associated with a significant increase in stroke volume index. With ATP, a 20% of maximum increase (P<0.05) in cardiac index (CI) was observed during the induced hypotension. In contrast, AP 4 A-induced hypotension did not result in any changes in CI throughout the observation period. The varying results concerning CI during the ATP- and AP 4 A-induced hypotension were probably due to differences in ventricular filling pressure, since AP 4 A-induced hypotension was associated with decreases (P<0.01) in both right atrial and pulmonary capillary wedge pressures, whereas neither of these variables significantly changed with ATP. The hypotension induced by either ATP or AP 4 A was associated with a significant decrease in heart rate (HR). However, both the magnitude and duration of decreases in HR due to ATP-induced hypotension were more pronounced than those seen with AP 4 A. In conclusion, while both drugs were equally capable of inducing hypotension, our results suggest that AP 4 A was more suitable for induced hypotension because of its potent vasodilatory action with venodilation and less negative chronotropic action.

Heritability, linkage, and genetic associations of exercise treadmill test responses.

PubMed

Ingelsson, Erik; Larson, Martin G; Vasan, Ramachandran S; O'Donnell, Christopher J; Yin, Xiaoyan; Hirschhorn, Joel N; Newton-Cheh, Christopher; Drake, Jared A; Musone, Stacey L; Heard-Costa, Nancy L; Benjamin, Emelia J; Levy, Daniel; Atwood, Larry D; Wang, Thomas J; Kathiresan, Sekar

2007-06-12

The blood pressure (BP) and heart rate responses to exercise treadmill testing predict incidence of cardiovascular disease, but the genetic determinants of hemodynamic and chronotropic responses to exercise are largely unknown. We assessed systolic BP, diastolic BP, and heart rate during the second stage of the Bruce protocol and at the third minute of recovery in 2982 Framingham Offspring participants (mean age 43 years; 53% women). With use of residuals from multivariable models adjusted for clinical correlates of exercise treadmill testing responses, we estimated the heritability (variance-components methods), genetic linkage (multipoint quantitative trait analyses), and association with 235 single-nucleotide polymorphisms in 14 candidate genes selected a priori from neurohormonal pathways for their potential role in exercise treadmill testing responses. Heritability estimates for heart rate during exercise and during recovery were 0.32 and 0.34, respectively. Heritability estimates for BP variables during exercise were 0.25 and 0.26 (systolic and diastolic BP) and during recovery, 0.16 and 0.13 (systolic and diastolic BP), respectively. Suggestive linkage was found for systolic BP during recovery from exercise (locus 1q43-44, log-of-the-odds score 2.59) and diastolic BP during recovery from exercise (locus 4p15.3, log-of-the-odds score 2.37). Among 235 single-nucleotide polymorphisms tested for association with exercise treadmill testing responses, the minimum nominal probability value was 0.003, which was nonsignificant after adjustment for multiple testing. Hemodynamic and chronotropic responses to exercise are heritable and demonstrate suggestive linkage to select loci. Genetic mapping with newer approaches such as genome-wide association may yield novel insights into the physiological responses to exercise.

Chronotropic incompetence and a higher frequency of myocardial ischemia in exercise echocardiography

PubMed Central

Oliveira, Joselina LM; Góes, Thiago JS; Santana, Thaiana A; Travassos, Thiago F; Teles, Lívia D; Anjos-Andrade, Fernando D; Nascimento-Júnior, Adão C; Alves, Érica O; Barreto, Martha A; Barreto-Filho, José A; D'Oliveira, Argemiro; Sousa, Antônio CS

2007-01-01

Background Exercise echocardiography (EE) is an established method to diagnose coronary artery disease (CAD). Chronotropic incompetence (CI) during the EE may be a marker of myocardial ischemia. The purpose of this investigation was to evaluate the additive value of CI during EE in CAD diagnosis. Methods Between 2000 and 2006, 4042 patients (1900 men with a mean age of 56 ± 11 years) were evaluated by EE. Based on the heart rate (HR) reached during the exercise test, the subjects were divided into two groups: G1 group – 490 patients who failed to achieve 85% of the maximal age-predicted HR, and G2 group – 3552 patients who were able to achieve 85% of the maximal age-predicted HR. Clinical characteristics, left ventricular wall motion abnormalities – wall motion score index (WMSI) – and coronary angiography (CA) were the parameters compared between the two groups. Results The left ventricular wall motion abnormalities were more frequent in G1 group than in G2 group (54% versus 26%; P < 0.00001). WMSI was higher in G1 group than in G2 group, both at rest (1.06 ± 0.17 versus 1.02 ± 0.09; P < 0.0001) and after exercise (1.12 ± 0.23 versus 1.04 ± 0.21; P < 0.0001). In G1 group, 82% of the patients with positive EE for myocardial ischemia presented obstructive coronary, compared to 71% (P = 0.03) in G2 group. Conclusion CI is associated with a higher frequency of myocardial ischemia during EE, reinforcing the concept that CI is a marker of the severity of myocardial ischemia. PMID:17980022

ST segment/heart rate hysteresis improves the diagnostic accuracy of ECG stress test for coronary artery disease in patients with left ventricular hypertrophy.

PubMed

Zimarino, Marco; Montebello, Elena; Radico, Francesco; Gallina, Sabina; Perfetti, Matteo; Iachini Bellisarii, Francesco; Severi, Silva; Limbruno, Ugo; Emdin, Michele; De Caterina, Raffaele

2016-10-01

The exercise electrocardiographic stress test (ExET) is the most widely used non-invasive diagnostic method to detect coronary artery disease. However, the sole ST depression criteria (ST-max) have poor specificity for coronary artery disease in patients with left ventricular hypertrophy. We hypothesised that ST-segment depression/heart rate hysteresis, depicting the relative behaviour of ST segment depression during the exercise and recovery phase of the test might increase the diagnostic accuracy of ExET for coronary artery disease detection in such patients. In three cardiology centres, we studied 113 consecutive patients (mean age 66 ± 2 years; 88% men) with hypertension-related left ventricular hypertrophy at echocardiography, referred to coronary angiography after an ExET. The following ExET criteria were analysed: ST-max, chronotropic index, heart rate recovery, Duke treadmill score, ST-segment depression/heart rate hysteresis. We detected significant coronary artery disease at coronary angiography in 61 patients (53%). At receiver-operating characteristic analysis, ST-segment depression/heart rate hysteresis had the highest area under the curve value (0.75, P < 0.001 when compared with the 'neutral' receiver-operating characteristic curve value of 0.5). Area under the curve values were 0.68 (P < 0.01) for the chronotropic index, 0.58 (P = NS) for heart rate recovery, 0.57 (P = NS) for ST-max and 0.52 (P = NS) for the Duke treadmill score. Among currently available ExET diagnostic variables, ST-segment depression/heart rate hysteresis offers a substantially better diagnostic accuracy for coronary artery disease than conventional criteria in patients with hypertension-related left ventricular hypertrophy. © The European Society of Cardiology 2016.

Impaired chronotropic and vasodilator reserves limit exercise capacity in patients with heart failure and a preserved ejection fraction.

PubMed

Borlaug, Barry A; Melenovsky, Vojtech; Russell, Stuart D; Kessler, Kristy; Pacak, Karel; Becker, Lewis C; Kass, David A

2006-11-14

Nearly half of patients with heart failure have a preserved ejection fraction (HFpEF). Symptoms of exercise intolerance and dyspnea are most often attributed to diastolic dysfunction; however, impaired systolic and/or arterial vasodilator reserve under stress could also play an important role. Patients with HFpEF (n=17) and control subjects without heart failure (n=19) generally matched for age, gender, hypertension, diabetes mellitus, obesity, and the presence of left ventricular hypertrophy underwent maximal-effort upright cycle ergometry with radionuclide ventriculography to determine rest and exercise cardiovascular function. Resting cardiovascular function was similar between the 2 groups. Both had limited exercise capacity, but this was more profoundly reduced in HFpEF patients (exercise duration 180+/-71 versus 455+/-184 seconds; peak oxygen consumption 9.0+/-3.4 versus 14.4+/-3.4 mL x kg(-1) x min(-1); both P<0.001). At matched low-level workload, HFpEF subjects displayed approximately 40% less of an increase in heart rate and cardiac output and less systemic vasodilation (all P<0.05) despite a similar rise in end-diastolic volume, stroke volume, and contractility. Heart rate recovery after exercise was also significantly delayed in HFpEF patients. Exercise capacity correlated with the change in cardiac output, heart rate, and vascular resistance but not end-diastolic volume or stroke volume. Lung blood volume and plasma norepinephrine levels rose similarly with exercise in both groups. HFpEF patients have reduced chronotropic, vasodilator, and cardiac output reserve during exercise compared with matched subjects with hypertensive cardiac hypertrophy. These limitations cannot be ascribed to diastolic abnormalities per se and may provide novel therapeutic targets for interventions to improve exercise capacity in this disorder.

The Nitrate-nitrite-NO pathway and its implications for Heart Failure and Preserved Ejection Fraction

PubMed Central

Chirinos, Julio A.; Zamani, Payman

2016-01-01

The pathogenesis of exercise intolerance in patients with heart failure and preserved ejection fraction (HFpEF) is likely multifactorial. In addition to cardiac abnormalities (diastolic dysfunction, abnormal contractile reserve, chronotropic incompetence), several peripheral abnormalities are likely to be involved. These include abnormal pulsatile hemodynamics, abnormal arterial vasodilatory responses to exercise, and abnormal peripheral O2 delivery, extraction and utilization. The nitrate-nitrite-NO pathway is emerging as a potential target to modify key physiologic abnormalities, including late systolic LV load from arterial wave reflections (which has deleterious short- and long-term consequences for the LV), arterial vasodilatory reserve, muscle O2 delivery, and skeletal muscle mitochondrial function. In a recently completed randomized trial, the administration of a single dose of exogenous inorganic nitrate has been shown exert various salutary arterial hemodynamic effects, ultimately leading to enhanced aerobic capacity in patients with HFpEF. These effects have the potential for both immediate improvements in exercise tolerance and for long-term “disease-modifying” effects. In this review, we provide an overview of key mechanistic contributors to exercise intolerance in HFpEF, and of the potential therapeutic role of drugs that target the nitrate-nitrite-NO pathway. PMID:26792295

Sensors for rate responsive pacing

PubMed Central

Dell'Orto, Simonetta; Valli, Paolo; Greco, Enrico Maria

2004-01-01

Advances in pacemaker technology in the 1980s have generated a wide variety of complex multiprogrammable pacemakers and pacing modes. The aim of the present review is to address the different rate responsive pacing modalities presently available in respect to physiological situations and pathological conditions. Rate adaptive pacing has been shown to improve exercise capacity in patients with chronotropic incompetence. A number of activity and metabolic sensors have been proposed and used for rate control. However, all sensors used to optimize pacing rate metabolic demands show typical limitations. To overcome these weaknesses the use of two sensors has been proposed. Indeed an unspecific but fast reacting sensor is combined with a more specific but slower metabolic one. Clinical studies have demonstrated that this methodology is suitable to reproduce normal sinus behavior during different types and loads of exercise. Sensor combinations require adequate sensor blending and cross checking possibly controlled by automatic algorithms for sensors optimization and simplicity of programming. Assessment and possibly deactivation of some automatic functions should be also possible to maximize benefits from the dual sensor system in particular conditions. This is of special relevance in patient whose myocardial contractility is limited such as in subjects with implantable defibrillators and biventricular pacemakers. The concept of closed loop pacing, implementing a negative feedback relating pacing rate and the control signal, will provide new opportunities to optimize dual-sensors system and deserves further investigation. The integration of rate adaptive pacing into defibrillators is the natural consequence of technical evolution. PMID:16943981

[Pharmacologic action profile of crataegus extract in comparison to epinephrine, amirinone, milrinone and digoxin in the isolated perfused guinea pig heart].

PubMed

Joseph, G; Zhao, Y; Klaus, W

1995-12-01

Using isolated perfused guinea pig hearts experiments were performed to investigate the influence of crataegus extract LI 132 (Faros 300, CRA) in comparison to other inotropic drugs--epinephrine (adrenaline, ADR), amrinone (AM), milrinone (MIL) and digoxin (DIG)--on different functional parameters, with special emphasis on the effective refractory period of the myocardium. The simultaneous registration of appropriate parameters allowed to relate the effect on the refractory period to the inotropic, chronotropic, dromotropic and coronary actions of these compounds at each concentration level. All substances--with the exception of CRA--shortened the effective refractory period concentration-dependently besides their known other functional effects (max.: 1 x 10(-5) mol/l ADR by 38%, 7 x 10(-7) mol/l DIG by 26%, 1 x 10(-4) mol/l MIL by 13% and 5 x 10(-4) mol/l AM by 1.6%). Related to the positive inotropy the shortening was most effective under MIL (1.32 ms/mN), followed by AM (0.65 ms/mN), DIG (0.40 ms/mN) and ADR (0.28 ms/mN). On the contrary, CRA produced a prolongation of the effective refractory period by maximally 10% resp. by 2.54 ms/mN. Thus, the pharmacologic profile of CRA differs from that of other inotropic compounds mainly in this parameter (with potentially reduced arrhythmogenic risk).

Resting Bradycardia, Enhanced Postexercise Heart Rate Recovery and Cardiorespiratory Fitness in Recreational Ballroom Dancers.

PubMed

Cruz, Carlos Janssen Gomes da; Molina, Guilherme Eckhardt; Porto, Luiz Guilherme Grossi; Junqueira, Luiz Fernando

2017-09-01

In a cross-sectional study design, we evaluated the resting heart rate (HR baseline ) and exercise and postexercise stress test-related chronotropic responses in male practitioners of recreational ballroom dancing (BD; n = 25, M age = 26.6 ± 6.1 years) compared to a control group of insufficiently active nondancers (CG; n = 25, M age = 25.9 ± 4.5 years). All participants underwent a submaximal exercise test. At 85% of the maximal predicted HR, the recovery protocol was started, and heart rate recovery (HRR) was recorded during 1-min intervals for 5 min. Compared with CG, BD showed lower HR baseline (70 beats per minute [bpm] vs. 62 bpm, respectively, U = 143, p < .05, ES = .46), lower preexercise HR (94 bpm vs. 86 bpm, U = 157, p < .05, ES = .42), longer exercise test duration (346 s vs. 420 s, U = 95.5, p < .05, ES = .59), and higher HRR for 5 min postexercise (U = 1.29-1.89, p < .05, ES = .33-.50) as follows: 1st min (32 bpm vs. 40 bpm), 2nd min (45 bpm vs. 53 bpm), 3rd min (51 bpm vs. 58 bpm), 4th min (55 bpm vs. 59 bpm), and 5th min (59 bpm vs. 63 bpm). The coefficient of HRR from the 1st min to the 5th min postexercise was similar in both groups (U = 229-311, p > .05, ES = < .10-.22). Heightened cardiovascular functional status characterized by favorable enhanced chronotropic dynamics appears to occur in practitioners of recreational ballroom dancing, which suggests that this modality of exercise may result in health benefits.

Long-term survival in patients undergoing cardiac resynchronization therapy: the importance of performing atrio-ventricular junction ablation in patients with permanent atrial fibrillation

PubMed Central

Gasparini, Maurizio; Auricchio, Angelo; Metra, Marco; Regoli, François; Fantoni, Cecilia; Lamp, Barbara; Curnis, Antonio; Vogt, Juergen; Klersy, Catherine

2008-01-01

Aims To investigate the effects of cardiac resynchronization therapy (CRT) on survival in heart failure (HF) patients with permanent atrial fibrillation (AF) and the role of atrio-ventricular junction (AVJ) ablation in these patients. Methods and results Data from 1285 consecutive patients implanted with CRT devices are presented: 1042 patients were in sinus rhythm (SR) and 243 (19%) in AF. Rate control in AF was achieved by either ablating the AVJ in 118 patients (AVJ-abl) or prescribing negative chronotropic drugs (AF-Drugs). Compared with SR, patients with AF were significantly older, more likely to be non-ischaemic, with higher ejection fraction, shorter QRS duration, and less often received ICD back-up. During a median follow-up of 34 months, 170/1042 patients in SR and 39/243 in AF died (mortality: 8.4 and 8.9 per 100 person-year, respectively). Adjusted hazard ratios were similar for all-cause and cardiac mortality [0.9 (0.57–1.42), P = 0.64 and 1.00 (0.60–1.66) P = 0.99, respectively]. Among AF patients, only 11/118 AVJ-abl patients died vs. 28/125 AF-Drugs patients (mortality: 4.3 and 15.2 per 100 person-year, respectively, P < 0.001). Adjusted hazard ratios of AVJ-abl vs. AF-Drugs was 0.26 [95% confidence interval (CI) 0.09–0.73, P = 0.010] for all-cause mortality, 0.31 (95% CI 0.10–0.99, P = 0.048) for cardiac mortality, and 0.15 (95% CI 0.03–0.70, P = 0.016) for HF mortality. Conclusion Patients with HF and AF treated with CRT have similar mortality compared with patients in SR. In AF, AVJ ablation in addition to CRT significantly improves overall survival compared with CRT alone, primarily by reducing HF death. PMID:18390869

Antihypertensive effect of the methanolic extract from Eruca sativa Mill., (Brassicaceae) in rats: muscarinic receptor-linked vasorelaxant and cardiotonic effects.

PubMed

Salma, Umme; Khan, Taous; Shah, Abdul Jabbar

2018-06-15

Eruca sativa Mill., (Brassicaceae) is a popular remedy for the treatment of hypertension in Pakistan. However, direct effect of the extract and its fractions on blood pressure and vascular tone are unknown. This investigation was aimed to explore the pharmacological base for the traditional use of E. sativa in hypertension. In-vivo blood pressure study was carried out using normotensive and high salt-induced hypertensive rats under anaesthesia. The cardiovascular mechanisms were explored using rat aorta and atria in-vitro. Preliminary phytochemical analysis, spectrophotometric detection of total phenols, flavonoids and HPLC analysis of crude extract were performed using quercetin and erucin as marker compounds. Intravenous injection of crude extract induced a fall in mean arterial pressure (MAP) in both normotensive (max fall: 41.79±1.55% mmHg) and hypertensive (max fall: 58.25±0.91% mmHg) rats. Atropine (1mg/kg) pretreatment attenuated this effect significantly (p < 0.001), suggesting the involvement of muscarinic receptor in its antihypertensive effect. Fractions also induced atropine-sensitive antihypertensive effect. Similarly, oral administration of crude and aqueous extracts resulted a fall in MAP in the hypertensive rats. In isolated rat aortic rings from normotensive rats, crude extract and fractions induced an endothelium-dependent relaxation. This relaxation was partially inhibited with L- NAME and atropine pretreatment and with denudation of aortic rings, indicating involvement of muscarinic receptor-linked nitric oxide (NO). In aorta from the hypertensive rats, crude extract and fractions induced endothelium-independent relaxation. This relaxation was not affected by pretreatment with L- NAME or atropine. Crude extract and fractions also suppressed phenylephrine contractions in Ca +2 free/EGTA medium. In isolated rat atrial preparations, crude extract and fractions induced negative inotropic and chronotropic effects with a positive inotropic effect by the n-hexane fraction, which were not affected with atropine pretreatment. Phytochemical screening and spectrophotometric analysis indicated the presence of phenols and flavonoids, whereas HPLC analysis of crude extract revealed the presence of quercetin (flavonoid) and erucin (isothiocyanate). The results suggest that E. sativa is an antihypertensive remedy which is mainly due to its vasodilatory and partly cardiac effects. Muscarinic receptors-linked NO release and dual inhibitory effect on Ca +2 influx and release underlie the vasodilation. This finding provides pharmacological base to the traditional use of E. sativa in hypertension. The presence of quercetin and erucin further support this finding. Copyright © 2018. Published by Elsevier B.V.

Zolpidem arousing effect in persistent vegetative state patients: autonomic, EEG and behavioral assessment.

PubMed

Machado, Calixto; Estévez, Mario; Rodríguez, Rafael; Pérez-Nellar, Jesús; Chinchilla, Mauricio; DeFina, Philip; Leisman, Gerry; Carrick, Frederick R; Melillo, Robert; Schiavi, Adam; Gutiérrez, Joel; Carballo, Maylén; Machado, Andrés; Olivares, Ana; Pérez-Cruz, Nuvia

2014-01-01

To study the Zolpidem arousing effect in persistent vegetative state (PVS) patients combining clinical evaluation, autonomic assessment by heart rate variability (HRV), and EEG records. We studied a group of 8 PVS patients and other 8 healthy control subjects, matched by age and gender. The patients and controls received drug or placebo in two experimental sessions, separated by 10-14 days. The first 30 minutes of the session were considered the basal record, and then Zolpidem was administered. All participants were evaluated clinically, by EEG, and by HRV during the basal record, and for 90 minutes after drug intake. We found in all patients, time-related arousing signs after Zolpidem intake: behavioral (yawns and hiccups), activation of EEG cortical activity, and a vagolytic chronotropic effect without a significant increment of the vasomotor sympathetic tone. We demonstrated time-related arousing signs after Zolpidem intake. We discussed possible mechanisms to explain these patho-physiological findings regarding EEG cortical activation and an autonomic vagolytic drug effect. As this autonomic imbalance might induce cardiocirculatory complications, which we didn't find in any of our patients, we suggest developing future trials under control of physiological indices by bedside monitoring. However, considering that this arousing Zolpidem effect might be certainly related to brain function improvement, it should be particularly considered for the development of new neuro-rehabilitation programs in PVS cases. According to the literature review, we claim that this is the first report about the vagolitic effect of Zolpidem in PVS cases.

Electrophysiological properties of prion-positive cardiac progenitors derived from murine embryonic stem cells.

PubMed

Fujii, Hiroshi; Ikeuchi, Yu; Kurata, Yasutaka; Ikeda, Nobuhito; Bahrudin, Udin; Li, Peili; Nakayama, Yuji; Endo, Ryo; Hasegawa, Akira; Morikawa, Kumi; Miake, Junichiro; Yoshida, Akio; Hidaka, Kyoko; Morisaki, Takayuki; Ninomiya, Haruaki; Shirayoshi, Yasuaki; Yamamoto, Kazuhiro; Hisatome, Ichiro

2012-01-01

The prion protein (PrP) has been reported to serve as a surface maker for isolation of cardiomyogenic progenitors from murine embryonic stem (ES) cells. Although PrP-positive cells exhibited automaticity, their electrophysiological characteristics remain unresolved. The aim of the present study was therefore to investigate the electrophysiological properties of PrP-positive cells in comparison with those of HCN4p-or Nkx2.5-positive cells. Differentiation of AB1, HCN5p-EGFP and hcgp7 ES cells into cardiac progenitors was induced by embryoid body (EB) formation. EBs were dissociated and cells expressing PrP, HCN4-EGFP and/or Nkx2.5-GFP were collected via flow cytometry. Sorted cells were subjected to reverse transcriptase-polymerase chain reaction, immunostaining and patch-clamp experiments. PrP-positive cells expressed mRNA of undifferentiation markers, first and second heart field markers, and cardiac-specific genes and ion channels, indicating their commitment to cardiomyogenic progenitors. PrP-positive cells with automaticity showed positive and negative chronotropic responses to isoproterenol and carbamylcholine, respectively. Hyperpolarization-activated cation current (I(f)) was barely detectable, whereas Na(+) and L-type Ca(2+) channel currents were frequently observed. Their spontaneous activity was slowed by inhibition of sarcoplasmic reticulum Ca(2+) uptake and release but not by blocking I(f). The maximum diastolic potential of their spontaneous firings was more depolarized than that of Nkx2.5-GFP-positive cells. PrP-positive cells contained cardiac progenitors that separated from the lineage of sinoatrial node cells. PrP can be used as a marker to enrich nascent cardiac progenitors.

Curcuma longa L. as a therapeutic agent in intestinal motility disorders. 2: Safety profile in mouse.

PubMed

Micucci, Matteo; Aldini, Rita; Cevenini, Monica; Colliva, Carolina; Spinozzi, Silvia; Roda, Giulia; Montagnani, Marco; Camborata, Cecilia; Camarda, Luca; Chiarini, Alberto; Mazzella, Giuseppe; Budriesi, Roberta

2013-01-01

Curcuma extract exerts a myorelaxant effect on the mouse intestine. In view of a possible use of curcuma extract in motor functional disorders of the gastrointestinal tract, a safety profile study has been carried out in the mouse. Thirty mice were used to study the in vitro effect of curcuma on gallbladder, bladder, aorta and trachea smooth muscular layers and hearth inotropic and chronotropic activity. The myorelaxant effect on the intestine was also thoroughly investigated. Moreover, curcuma extract (200 mg/Kg/day) was orally administered to twenty mice over 28 days and serum liver and lipids parameters were evaluated. Serum, bile and liver bile acids qualitative and quantitative composition was were also studied. In the intestine, curcuma extract appeared as a not competitive inhibitor through cholinergic, histaminergic and serotoninergic receptors and showed spasmolytic effect on K(+) induced contraction at the level of L type calcium channels. No side effect was observed on bladder, aorta, trachea and heart when we used a dose that is effective on the intestine. An increase in gallbladder tone and contraction was observed. Serum liver and lipids parameters were normal, while a slight increase in serum and liver bile acids concentration and a decrease in bile were observed. Although these data are consistent with the safety of curcuma extract as far as its effect on the smooth muscular layers of different organs and on the heart, the mild cholestatic effect observed in absence of alteration of liver function tests must be further evaluated and the effective dose with minimal side effects considered.

Curcuma longa L. as a Therapeutic Agent in Intestinal Motility Disorders. 2: Safety Profile in Mouse

PubMed Central

Micucci, Matteo; Aldini, Rita; Cevenini, Monica; Colliva, Carolina; Spinozzi, Silvia; Roda, Giulia; Montagnani, Marco; Camborata, Cecilia; Camarda, Luca; Chiarini, Alberto; Mazzella, Giuseppe; Budriesi, Roberta

2013-01-01

Background Curcuma extract exerts a myorelaxant effect on the mouse intestine. In view of a possible use of curcuma extract in motor functional disorders of the gastrointestinal tract, a safety profile study has been carried out in the mouse. Methods Thirty mice were used to study the in vitro effect of curcuma on gallbladder, bladder, aorta and trachea smooth muscular layers and hearth inotropic and chronotropic activity. The myorelaxant effect on the intestine was also thoroughly investigated. Moreover, curcuma extract (200 mg/Kg/day) was orally administered to twenty mice over 28 days and serum liver and lipids parameters were evaluated. Serum, bile and liver bile acids qualitative and quantitative composition was were also studied. Results In the intestine, curcuma extract appeared as a not competitive inhibitor through cholinergic, histaminergic and serotoninergic receptors and showed spasmolytic effect on K+ induced contraction at the level of L type calcium channels. No side effect was observed on bladder, aorta, trachea and heart when we used a dose that is effective on the intestine. An increase in gallbladder tone and contraction was observed. Serum liver and lipids parameters were normal, while a slight increase in serum and liver bile acids concentration and a decrease in bile were observed. Conclusions Although these data are consistent with the safety of curcuma extract as far as its effect on the smooth muscular layers of different organs and on the heart, the mild cholestatic effect observed in absence of alteration of liver function tests must be further evaluated and the effective dose with minimal side effects considered. PMID:24260512

[Pharmacological possibilities for the prevention of complications following myocardial infarction].

PubMed

Szekeres, L

1986-01-01

Sudden cardiac death (SCD) due to acute myocardial infarction (AMI) is mostly the result of ventricular fibrillation (VP) which is an electrical accident appearing on the basis of electrical instability of the myocardium. In addition to the chronic electrical instability predisposing to ventricular arrhythmias the trigger effect of a precipitating factor also seems necessary which may disrupt the normal sequence of cardiac contractions. In view of this hypothesis the following strategy of therapeutic interventions aimed at preventing SCD from AMI seems to be logical: Prophylactic measures to prevent pathological processes underlying chronic electrical instability of the heart i.e. elimination of identified risk factors of ischemic heart disease. Protection from SCD due to AMI: by using drugs which could, prevent further electrical destabilization as shifts in myocardial and plasma ionic balance, in pH, in pCO2, accumulation of potentially arrhythmogenic metabolites: Inhibit the trigger effect of sudden changes: in hemodynamics, in the autonomic nervous outflow and balance. The general supportive measures include therapeutic interventions which are not directly connected with appearance of lethal arrhythmias but may indirectly contribute to their development as pain, arterial Hb desaturation, deep vein thrombosis. Some of the measures listed above are capable of limiting the size of the developing infarct, a major determinant of the future conditions of life and prognosis of the patient. In the prehospital phase of AMI when two thirds of all coronary deaths occur general supportive measures and drug treatment of life threatening arrhythmias should be applied simultaneously. Sedatives and anxiolytics, furthermore analgetics are widely used. They are however often associated with bradycardia and sometimes with hypotension. This latter is dominant in patients with inferior infarction, showing a parasympathetic hyperactivity, when atropine treatment is needed. Sympathetic hyperactivity responds to analgesia and sedation but beta blockers may be required to reduce increased MVO2. These agents belong to the group of anti-ischemic drugs. The beneficial anti-ischemic action of beta-blockers is mostly due to their negative chronotropic and inotropic effect. A direct metabolic action was shown by use as well as the presence of a positive steal phenomenon in the experimental angina model in dogs. Anti-ischemic action of coronary vasodilators. The most reliable drug for preventing or abolishing anginal attack is still the classic nitroglycerin. On the other hand persantine a potent coronary dilator failed to protect against anginal attack in man.

Discovery of novel and cardioselective diltiazem-like calcium channel blockers via virtual screening.

PubMed

Carosati, Emanuele; Budriesi, Roberta; Ioan, Pierfranco; Ugenti, Maria P; Frosini, Maria; Fusi, Fabio; Corda, Gaetano; Cosimelli, Barbara; Spinelli, Domenico; Chiarini, Alberto; Cruciani, Gabriele

2008-09-25

With the effort to discover new chemotypes blocking L-type calcium channels (LTCCs), ligand-based virtual screening was applied with a specific interest toward the diltiazem binding site. Roughly 50000 commercially available compounds served as a database for screening. The filtering through predicted pharmacokinetic properties and structural requirements reduced the initial database to a few compounds for which the similarity was calculated toward two template molecules, diltiazem and 4-chloro-Ncyclopropyl- N-(4-piperidinyl)benzene-sulfonamide, the most interesting hit of a previous screening experiment. For 18 compounds, inotropic and chronotropic activity as well as the vasorelaxant effect on guinea pig were studied "in vitro", and for the most promising, binding studies to the diltiazem site were carried out. The procedure yielded several hits, confirming in silico techniques to be useful for finding new chemotypes. In particular, N-[2-(dimethylamino)ethyl]-3-hydroxy-2-naphthamide, N,Ndimethyl- N'-(2-pyridin-3-ylquinolin-4-yl)ethane-1,2-diamine, 2-[(4-chlorophenyl)(pyridin-2-yl)methoxy]- N,N-dimethylethanamine (carbinoxamine), and 7-[2-(diethylamino)ethoxy]-2H-chromen-2-one revealed interesting activity and binding to the benzothiazepine site.

Current Perspectives on Systemic Hypertension in Heart Failure with Preserved Ejection Fraction.

PubMed

Tam, Marty C; Lee, Ran; Cascino, Thomas M; Konerman, Matthew C; Hummel, Scott L

2017-02-01

Heart failure with preserved ejection fraction (HFpEF) is a prevalent but incompletely understood syndrome. Traditional models of HFpEF pathophysiology revolve around systemic HTN and other causes of increased left ventricular afterload leading to left ventricular hypertrophy (LVH) and diastolic dysfunction. However, emerging models attribute the development of HFpEF to systemic proinflammatory changes secondary to common comorbidities which include HTN. Alterations in passive ventricular stiffness, ventricular-arterial coupling, peripheral microvascular function, systolic reserve, and chronotropic response occur. As a result, HFpEF is heterogeneous in nature, making it difficult to prescribe uniform therapies to all patients. Nonetheless, treating systemic HTN remains a cornerstone of HFpEF management. Antihypertensive therapies have been linked to LVH regression and improvement in diastolic dysfunction. However, to date, no therapies have definitive mortality benefit in HFpEF. Non-pharmacologic management for HTN, including dietary modification, exercise, and treating sleep disordered breathing, may provide some morbidity benefit in the HFpEF population. Future research is need to identify effective treatments, perhaps in more specific subgroups, and focus may need to shift from reducing mortality to improving exercise capacity and symptoms. Tailoring antihypertensive therapies to specific phenotypes of HFpEF may be an important component of this strategy.

Cardiac response to whole-body heating

DOE Office of Scientific and Technical Information (OSTI.GOV)

Frey, M.A.B.; Kenney, R.A.

1979-04-01

Systolic time interval analysis was used to assess changes in ventricular function during heat stress. Seven subjects (4 M + 3 F, 22-35 yr) participated in the experiments. The heating procedure was the following: both legs of seated subjects were immersed to the knees in stirred water maintained at 42-45 C. The subjects' upper legs and trunks were enclosed in nonpermeable plastic and covered with a sheet blanket to reduce heat loss. After 30 min of heating, the water and plastic were removed. The parameters measured were HR and R-R interval, LVET, and PEP. Results were compared by t testmore » at the 0.05 significance level. The results pointed to a two-stage cardiac response to heat-vagal withdrawal followed by a strong sympathetic outflow to the heart affecting both inotropic and chronotropic characteristics.« less

Electrophysiology and metabolism of caveolin-3 overexpressing mice

PubMed Central

Schilling, Jan M.; Horikawa, Yousuke T.; Zemljic-Harpf, Alice E.; Vincent, Kevin P.; Tyan, Leonid; Yu, Judith K.; McCulloch, Andrew D.; Balijepalli, Ravi C.; Patel, Hemal H.; Roth, David M.

2017-01-01

Caveolin-3 (Cav-3) plays a critical role in organizing signaling molecules and ion channels involved in cardiac conduction and metabolism. Mutations in Cav-3 are implicated in cardiac conduction abnormalities and myopathies. Additionally, cardiac specific overexpression of Cav-3 (Cav-3 OE) is protective against ischemic and hypertensive injury suggesting a potential role for Cav-3 in basal cardiac electrophysiology and metabolism involved in stress adaptation. We hypothesized that overexpression of Cav-3 may alter baseline cardiac conduction and metabolism. We examined: 1) ECG telemetry recordings at baseline and during pharmacological interventions, 2) ion channels involved in cardiac conduction with immunoblotting and computational modeling, and 3) baseline metabolism in Cav-3 OE and transgene negative littermate control mice. Cav-3 OE mice had decreased heart rates, prolonged PR intervals, and shortened QTc intervals with no difference in activity compared to control mice. Dobutamine or propranolol did not cause significant changes between experimental groups in maximal (dobutamine) or minimal (propranolol) heart rate. Cav-3 OE mice had an overall lower chronotropic response to atropine. Expression of Kv1.4 and Kv4.3 channels, Nav1.5 channels and connexin 43 were increased in Cav-3 OE mice. A computational model integrating the immunoblotting results indicated shortened action potential duration in Cav-3 OE mice linking the change in channel expression to the observed electrophysiology phenotype. Metabolic profiling showed no gross differences in VO2, VCO2, respiratory exchange ratio, and heat generation, feeding or drinking. In conclusion, Cav-3 OE mice have changes in ECG intervals, heart rates, and cardiac ion channel expression. These findings give novel mechanistic insights into previously reported Cav-3 dependent cardioprotection. PMID:27023865

Remodeling of cardiac cholinergic innervation and control of heart rate in mice with streptozotocin-induced diabetes.

PubMed

Mabe, Abigail M; Hoover, Donald B

2011-07-05

Cardiac autonomic neuropathy is a frequent complication of diabetes and often presents as impaired cholinergic regulation of heart rate. Some have assumed that diabetics have degeneration of cardiac cholinergic nerves, but basic knowledge on this topic is lacking. Accordingly, our goal was to evaluate the structure and function of cardiac cholinergic neurons and nerves in C57BL/6 mice with streptozotocin-induced diabetes. Electrocardiograms were obtained weekly from conscious control and diabetic mice for 16 weeks. Resting heart rate decreased in diabetic mice, but intrinsic heart rate was unchanged. Power spectral analysis of electrocardiograms revealed decreased high frequency and increased low frequency power in diabetic mice, suggesting a relative reduction of parasympathetic tone. Negative chronotropic responses to right vagal nerve stimulation were blunted in 16-week diabetic mice, but postjunctional sensitivity of isolated atria to muscarinic agonists was unchanged. Immunohistochemical analysis of hearts from diabetic and control mice showed no difference in abundance of cholinergic neurons, but cholinergic nerve density was increased at the sinoatrial node of diabetic mice (16 weeks: 14.9±1.2% area for diabetics versus 8.9±0.8% area for control, P<0.01). We conclude that disruption of cholinergic function in diabetic mice cannot be attributed to a loss of cardiac cholinergic neurons and nerve fibers or altered cholinergic sensitivity of the atria. Instead, decreased responses to vagal stimulation might be caused by a defect of preganglionic cholinergic neurons and/or ganglionic neurotransmission. The increased density of cholinergic nerves observed at the sinoatrial node of diabetic mice might be a compensatory response. Copyright © 2011 Elsevier B.V. All rights reserved.

Anxiety and beta-adrenergic receptor function in a normal population.

PubMed

Kang, Eun-Ho; Yu, Bum-Hee

2005-06-01

Many studies have shown a close relationship between anxiety and beta-adrenergic receptor function in patients with anxiety disorders. This study examined the relationship between beta-adrenergic receptor function and anxiety levels in a normal population. Subjects for this study included 36 men and 44 women between the ages of 20 and 40 years whose Body Mass Index (BMI) was between 18 and 26. All of them were healthy subjects who had no previous history of medical or psychiatric illnesses. The authors measured the Spielberger State-Trait Anxiety Inventory (STAI), Beck Depression Inventory (BDI), and Chronotropic 25 Dose (CD25) of isoproterenol, previously developed to assess in vivo beta-adrenergic receptor sensitivity. We also examined correlations between log normalized CD25 and mood states. The mean of CD25 was 2.64+/-1.37 mug and the mean of CD25 in men was significantly higher (i.e., lower beta-adrenergic receptor sensitivity) than that of women (3.26+/-1.35 vs. 2.14+/-1.17 microg; t = 3.99, p < 0.001). CD25 showed negative correlations with STAI state anxiety (r = -0.344, p = 0.002), trait anxiety (r = -0.331, p = 0.003), and BDI (r = -0.283, p = 0.011). CD25 was positively correlated with BMI (r = 0.423, p < 0.001) and age (r = 0.271, p = 0.015). In stepwise multiple regression analyses, 34% of the variance in CD25 was accounted for by sex, state anxiety, and BMI. The sensitivity of beta-adrenergic receptors increased as anxiety levels became higher in a normal population. Thus, the relationship between anxiety and beta-adrenergic receptor function in healthy subjects may be different from that of patients with anxiety disorders.

Electrical Stimulation Promotes Cardiac Differentiation of Human Induced Pluripotent Stem Cells

PubMed Central

Hernández, Damián; Millard, Rodney; Sivakumaran, Priyadharshini; Wong, Raymond C. B.; Crombie, Duncan E.; Hewitt, Alex W.; Liang, Helena; Hung, Sandy S. C.; Pébay, Alice; Shepherd, Robert K.; Dusting, Gregory J.; Lim, Shiang Y.

2016-01-01

Background. Human induced pluripotent stem cells (iPSCs) are an attractive source of cardiomyocytes for cardiac repair and regeneration. In this study, we aim to determine whether acute electrical stimulation of human iPSCs can promote their differentiation to cardiomyocytes. Methods. Human iPSCs were differentiated to cardiac cells by forming embryoid bodies (EBs) for 5 days. EBs were then subjected to brief electrical stimulation and plated down for 14 days. Results. In iPS(Foreskin)-2 cell line, brief electrical stimulation at 65 mV/mm or 200 mV/mm for 5 min significantly increased the percentage of beating EBs present by day 14 after plating. Acute electrical stimulation also significantly increased the cardiac gene expression of ACTC1, TNNT2, MYH7, and MYL7. However, the cardiogenic effect of electrical stimulation was not reproducible in another iPS cell line, CERA007c6. Beating EBs from control and electrically stimulated groups expressed various cardiac-specific transcription factors and contractile muscle markers. Beating EBs were also shown to cycle calcium and were responsive to the chronotropic agents, isoproterenol and carbamylcholine, in a concentration-dependent manner. Conclusions. Our results demonstrate that brief electrical stimulation can promote cardiac differentiation of human iPS cells. The cardiogenic effect of brief electrical stimulation is dependent on the cell line used. PMID:26788064

Cholinesterase Inhibitors and Hospitalization for Bradycardia: A Population-Based Study

PubMed Central

Park-Wyllie, Laura Y.; Mamdani, Muhammad M.; Li, Ping; Gill, Sudeep S.; Laupacis, Andreas; Juurlink, David N.

2009-01-01

Background Cholinesterase inhibitors are commonly used to treat dementia. These drugs enhance the effects of acetylcholine, and reports suggest they may precipitate bradycardia in some patients. We aimed to examine the association between use of cholinesterase inhibitors and hospitalization for bradycardia. Methods and Findings We examined the health care records of more than 1.4 million older adults using a case-time-control design, allowing each individual to serve as his or her own control. Case patients were residents of Ontario, Canada, aged 67 y or older hospitalized for bradycardia between January 1, 2003 and March 31, 2008. Control patients (3∶1) were not hospitalized for bradycardia, and were matched to the corresponding case on age, sex, and a disease risk index. All patients had received cholinesterase inhibitor therapy in the 9 mo preceding the index hospitalization. We identified 1,009 community-dwelling older persons hospitalized for bradycardia within 9 mo of using a cholinesterase inhibitor. Of these, 161 cases informed the matched analysis of discordant pairs. Of these, 17 (11%) required a pacemaker during hospitalization, and six (4%) died prior to discharge. After adjusting for temporal changes in drug utilization, hospitalization for bradycardia was associated with recent initiation of a cholinesterase inhibitor (adjusted odds ratio [OR] 2.13, 95% confidence interval [CI] 1.29–3.51). The risk was similar among individuals with pre-existing cardiac disease (adjusted OR 2.25, 95% CI 1.18–4.28) and those receiving negative chronotropic drugs (adjusted OR 2.34, 95% CI 1.16–4.71). We found no such association when we replicated the analysis using proton pump inhibitors as a neutral exposure. Despite hospitalization for bradycardia, more than half of the patients (78 of 138 cases [57%]) who survived to discharge subsequently resumed cholinesterase inhibitor therapy. Conclusions Among older patients, initiation of cholinesterase inhibitor therapy was associated with a more than doubling of the risk of hospitalization for bradycardia. Resumption of therapy following discharge was common, suggesting that the cardiovascular toxicity of cholinesterase inhibitors is underappreciated by clinicians. Please see later in the article for the Editors' Summary PMID:19787032

Patterns of beta-blocker intensification in ambulatory heart failure patients and short-term association with hospitalization

PubMed Central

2012-01-01

Background In response to the short-term negative inotropic and chronotropic effects of β-blockers, heart failure (HF) guidelines recommend initiating β-blockers at low dose with gradual uptitration as tolerated to doses used in clinical trials. However, patterns and safety of β-blocker intensification in routine practice are poorly described. Methods We described β-blocker intensification among Kaiser Colorado enrollees with a primary discharge diagnosis of HF between 2001–2009. We then assessed β-blocker intensification in the 30 days prior to first hospital readmission for cases compared to the same time period following index hospitalization for non-rehospitalized matched controls. In separate analysis of the subgroup initiated on β-blocker after index hospital discharge, we compared adjusted rates of 30-day hospitalization following initiation of high versus low dose β-blocker. Results Among 3,227 patients, median age was 76 years and 37% had ejection fraction ≤40% (LVSD). During a median follow up of 669 days, 14% were never on β-blocker, 21% were initiated on β-blocker, 43% were discharged on β-blocker but never uptitrated, and 22% had discharge β-blocker uptitrated; 63% were readmitted and 49% died. β-blocker intensification occurred in the 30 days preceding readmission for 39 of 1,674 (2.3%) readmitted cases compared to 27 (1.6%) of matched controls (adjusted OR 1.36, 95% CI 0.81-2.27). Among patients initiated on therapy, readmission over the subsequent 30 days occurred in 6 of 155 (3.9%) prescribed high dose and 9 of 513 (1.8%) prescribed low dose β-blocker (adjusted OR 3.10, 95% CI 1.02-9.40). For the subgroup with LVSD, findings were not significantly different. Conclusion While β-blockers were intensified in nearly half of patients following hospital discharge and high starting dose was associated with increased readmission risk, the prevailing finding was that readmission events were rarely preceded by β-blocker intensification. These data suggest that β-blocker intensification is not a major precipitant of hospitalization, provided recommended dosing is followed. PMID:22709128

Selective norepinephrine reuptake inhibition as a human model of orthostatic intolerance

NASA Technical Reports Server (NTRS)

Schroeder, Christoph; Tank, Jens; Boschmann, Michael; Diedrich, Andre; Sharma, Arya M.; Biaggioni, Italo; Luft, Friedrich C.; Jordan, Jens; Robertson, D. (Principal Investigator)

2002-01-01

BACKGROUND: Observations in patients with functional mutations of the norepinephrine transporter (NET) gene suggest that impaired norepinephrine uptake may contribute to idiopathic orthostatic intolerance. METHODS AND RESULTS: We studied the effect of the selective NET blocker reboxetine and placebo in a randomized, double-blind, crossover fashion on cardiovascular responses to cold pressor testing, handgrip testing, and a graded head-up tilt test (HUT) in 18 healthy subjects. In a subset, we determined isoproterenol and phenylephrine sensitivities. Subjects ingested 8 mg reboxetine or placebo 12 hours and 1 hour before testing. In the supine position, heart rate was 65+/-2 bpm with placebo and 71+/-3 bpm with reboxetine. At 75 degrees HUT, heart rate was 84+/-3 and 119+/-4 bpm with placebo and with reboxetine (P<0.0001). Mean arterial pressure was 85+/-2 with placebo and 91+/-2 mm Hg with reboxetine while supine (P<0.01) and 88+/-2 mm Hg and 90+/-3 mm Hg at 75 degrees HUT. Blood pressure responses to cold pressor and handgrip testing were attenuated with reboxetine. Reboxetine increased the sensitivity to the chronotropic effect of isoproterenol and the pressor effect of phenylephrine. Vasovagal reactions occurred in 9 subjects on placebo and in 1 subject on reboxetine. CONCLUSIONS: Selective NET blockade creates a phenotype that resembles idiopathic orthostatic intolerance. This observation supports the hypothesis that disordered norepinephrine uptake mechanisms can contribute to human cardiovascular disease. Our study also suggests that NET inhibition might be useful in preventing vasovagal reactions.

Reduced exercise capacity in persons with Down syndrome: cause, effect, and management

PubMed Central

Mendonca, Goncalo V; Pereira, Fernando D; Fernhall, Bo

2010-01-01

Persons with Down syndrome (DS) have reduced peak and submaximal exercise capacity. Because ambulation is one predictor of survival among adults with DS, a review of the current knowledge of the causes, effects, and management of reduced exercise capacity in these individuals would be important. Available data suggest that reduced exercise capacity in persons with DS results from an interaction between low peak oxygen uptake (VO2peak) and poor exercise economy. Of several possible explanations, chronotropic incompetence has been shown to be the primary cause of low VO2peak in DS. In contrast, poor exercise economy is apparently dependent on disturbed gait kinetics and kinematics resulting from joint laxity and muscle hypotonia. Importantly, there is enough evidence to suggest that such low levels of physical fitness (reduced exercise capacity and muscle strength) limit the ability of adults with DS to perform functional tasks of daily living. Consequently, clinical management of reduced exercise capacity in DS seems important to ensure that these individuals remain productive and healthy throughout their lives. However, few prospective studies have examined the effects of structured exercise training in this population. Existent data suggest that exercise training is beneficial for improving exercise capacity and physiological function in persons with DS. This article reviews the current knowledge of the causes, effects, and management of reduced exercise capacity in DS. This review is limited to the acute and chronic responses to submaximal and peak exercise intensities because data on supramaximal exercise capacity of persons with DS have been shown to be unreliable. PMID:21206759

Autoantibodies Targeting AT1 Receptor from Patients with Acute Coronary Syndrome Upregulate Proinflammatory Cytokines Expression in Endothelial Cells Involving NF-κB Pathway

PubMed Central

Li, Weijuan; Li, Zhi; Chen, Yaoqi; Li, Songhai; Lv, Yuanyuan; Zhou, Wenping; Liao, Mengyang; Zhu, Feng; Zhou, Zihua; Cheng, Xiang; Zeng, Qiutang; Liao, Yuhua; Wei, Yumiao

2014-01-01

Our study intended to prove whether agonistic autoantibodies to angiotensin II type 1 receptor (AT1-AAs) exist in patients with coronary heart disease (CHD) and affect the human endothelial cell (HEC) by upregulating proinflammatory cytokines expression involved in NF-κB pathway. Antibodies were determined by chronotropic responses of cultured neonatal rat cardiomyocytes coupled with receptor-specific antagonists (valsartan and AT1-EC2) as described previously. Interleukin-6 (IL-6), vascular cell adhesion molecule-1 (VCAM-1), and monocyte chemotactic protein-1 (MCP-1) expression were improved at both mRNA and protein levels in HEC, while NF-κB in the DNA level was improved detected by electrophoretic mobility shift assays (EMSA). These improvements could be inhibited by specific AT1 receptor blocker valsartan, NF-κB blocker pyrrolidine dithiocarbamate (PDTC), and specific short peptides from the second extracellular loop of AT1 receptor. These results suggested that AT1-AAs, via the AT1 receptor, induce expression of proinflammatory cytokines involved in the activation of NF-κB. AT1-AAs may play a great role in the pathogenesis of the acute coronary syndrome by mediating vascular inflammatory effects involved in the NF-κB pathway. PMID:25762441

Autoantibodies targeting AT1 receptor from patients with acute coronary syndrome upregulate proinflammatory cytokines expression in endothelial cells involving NF-κB pathway.

PubMed

Li, Weijuan; Li, Zhi; Chen, Yaoqi; Li, Songhai; Lv, Yuanyuan; Zhou, Wenping; Liao, Mengyang; Zhu, Feng; Zhou, Zihua; Cheng, Xiang; Zeng, Qiutang; Liao, Yuhua; Wei, Yumiao

2014-01-01

Our study intended to prove whether agonistic autoantibodies to angiotensin II type 1 receptor (AT1-AAs) exist in patients with coronary heart disease (CHD) and affect the human endothelial cell (HEC) by upregulating proinflammatory cytokines expression involved in NF-κB pathway. Antibodies were determined by chronotropic responses of cultured neonatal rat cardiomyocytes coupled with receptor-specific antagonists (valsartan and AT1-EC2) as described previously. Interleukin-6 (IL-6), vascular cell adhesion molecule-1 (VCAM-1), and monocyte chemotactic protein-1 (MCP-1) expression were improved at both mRNA and protein levels in HEC, while NF-κB in the DNA level was improved detected by electrophoretic mobility shift assays (EMSA). These improvements could be inhibited by specific AT1 receptor blocker valsartan, NF-κB blocker pyrrolidine dithiocarbamate (PDTC), and specific short peptides from the second extracellular loop of AT1 receptor. These results suggested that AT1-AAs, via the AT1 receptor, induce expression of proinflammatory cytokines involved in the activation of NF-κB. AT1-AAs may play a great role in the pathogenesis of the acute coronary syndrome by mediating vascular inflammatory effects involved in the NF-κB pathway.

Baroreflex function: determinants in healthy subjects and disturbances in diabetes, obesity and metabolic syndrome.

PubMed

Skrapari, Ioanna; Tentolouris, Nicholas; Katsilambros, Nicholas

2006-08-01

Arterial baroreceptors play an important role in the short-term regulation of arterial pressure, by reflex chronotropic effect on the heart and by reflex regulation of sympathetic outflow. Baroreflex sensitivity (BRS) represents an index of arterial baroreceptors function. Several methods of measuring BRS are available nowadays. Different factors influence BRS in the healthy population, including sex, age, blood pressure, heart rate, body fatness, arterial stiffness, blood glucose and insulin levels, as well as physical activity. Baroreceptors dysfunction is evident in diseases such as coronary artery disease, heart failure, arterial hypertension, diabetes mellitus and obesity. The underlying mechanism of BRS attenuation in diabetes or obesity is not yet well known; however, there is increasing evidence that it is at least partly related to autonomic nervous system dysfunction and particularly to sympathetic overactivity that accompanies these diseases. Blunted BRS provides prognostic information for cardiovascular diseases and possibly for diabetes, while its' prognostic information for obesity is not yet established. This review deals with the mechanisms affecting baroreflex function, the newer techniques of BRS estimation and the most recent insights of baroreflex function in the healthy population and in various diseases with emphasis on diabetes and obesity. In addition, the clinical implication of a reduced BRS in these disorders is discussed.

[Pharmacological studies on ginger. V. Pharmacological comparison between (6)-shogaol and capsaicin].

PubMed

Suekawa, M; Sone, H; Sakakibara, I; Ikeya, Y; Aburada, M; Hosoya, E

1986-11-01

Pharmacological actions of (6)-shogaol and capsaicin were studied. Both (6)-shogaol (0.5 mg/kg, i.v.) and capsaicin (0.1 mg/kg, i.v.) caused a triad such as a rapid fall in blood pressure, bradycardia and aponea in rats. Both drugs-induced marked pressor responses in blood pressure, which occurred after the rapid fall, were markedly reduced by a spinal destruction. In pithed rats, both drugs-induced peripheral pressor responses were markedly reduced with the combined treatment of [D-Arg1, D-Pro2, D-Trp7,9, Leu11]-substance P (0.5 mg/kg, i.v.), phentolamine (10 mg/kg, i.v.) and the section of sciatic nerves. In isolated guinea-pig trachea, (6)-shogaol (100 microM) and capsaicin (10 microM) induced contractile responses which were slightly inhibited by substance P antagonist (10 microM), but exhibited also a tachyphylaxis. Furthermore, although (6)-shogaol (3.6 microM) showed positive inotropic and chronotropic actions on isolated atria in rats, this effect of (6)-shogaol disappeared by repeated injections or pretreatment (100 mg/kg, s.c.) of (6)-shogaol. These results suggest that (6)-shogaol and capsaicin have similar actions, and that both drugs may cause a peripheral action by releasing an unknown active substance from nerve ends.

Human Cardiomyocytes Prior to Birth by Integration-Free Reprogramming of Amniotic Fluid Cells

PubMed Central

Jiang, Guihua; Herron, Todd J.; Di Bernardo, Julie; Walker, Kendal A.; O’Shea, K. Sue

2016-01-01

The establishment of an abundant source of autologous cardiac progenitor cells would represent a major advance toward eventual clinical translation of regenerative medicine strategies in children with prenatally diagnosed congenital heart disease. In support of this concept, we sought to examine whether functional, transgene-free human cardiomyocytes (CMs) with potential for patient-specific and autologous applications could be reliably generated following routine amniocentesis. Under institutional review board approval, amniotic fluid specimens (8–10 ml) at 20 weeks gestation were expanded and reprogrammed toward pluripotency using nonintegrating Sendai virus (SeV) expressing OCT4, SOX2, cMYC, and KLF4. Following exposure of these induced pluripotent stem cells to cardiogenic differentiation conditions, spontaneously beating amniotic fluid-derived cardiomyocytes (AF-CMs) were successfully generated with high efficiency. After 6 weeks, quantitative gene expression revealed a mixed population of differentiated atrial, ventricular, and nodal AF-CMs, as demonstrated by upregulation of multiple cardiac markers, including MYH6, MYL7, TNNT2, TTN, and HCN4, which were comparable to levels expressed by neonatal dermal fibroblast-derived CM controls. AF-CMs had a normal karyotype and demonstrated loss of NANOG, OCT4, and the SeV transgene. Functional characterization of SIRPA+ AF-CMs showed a higher spontaneous beat frequency in comparison with dermal fibroblast controls but revealed normal calcium transients and appropriate chronotropic responses after β-adrenergic agonist stimulation. Taken together, these data suggest that somatic cells present within human amniotic fluid can be used to generate a highly scalable source of functional, transgene-free, autologous CMs before a child is born. This approach may be ideally suited for patients with prenatally diagnosed cardiac anomalies. Significance This study presents transgene-free human amniotic fluid-derived cardiomyocytes (AF-CMs) for potential therapy in tissue engineering and regenerative medicine applications. Using 8–10 ml of amniotic fluid harvested at 20 weeks gestation from normal pregnancies, a mixed population of atrial, ventricular, and nodal AF-CMs were reliably generated after Sendai virus reprogramming toward pluripotency. Functional characterization of purified populations of beating AF-CMs revealed normal calcium transients and appropriate chronotropic responses after β-adrenergic agonist stimulation in comparison with dermal fibroblast controls. Because AF-CMs can be generated in fewer than 16 weeks, this approach may be ideally suited for eventual clinical translation at birth in children with prenatally diagnosed cardiac anomalies. PMID:27465073

Cardiovascular effects of fenoterol under conditions of hypoxaemia.

PubMed Central

Bremner, P; Burgess, C D; Crane, J; McHaffie, D; Galletly, D; Pearce, N; Woodman, K; Beasley, R

1992-01-01

BACKGROUND: The reason for the association of increased risk of death with fenoterol in patients with asthma in New Zealand is unknown but may relate to its cardiovascular effects. Most deaths from asthma occur outside hospital, where hypoxaemia is likely to be a complicating factor. The cardiovascular effects of fenoterol have been investigated therefore under conditions of normoxaemia and hypoxaemia. METHOD: Eight healthy men were studied on two occasions. Measurements of heart rate, blood pressure, total electromechanical systole (QS2I), electrocardiographic QTc interval, cardiac index, stroke volume, and ejection fraction were made under conditions of normoxaemia and hypoxaemia (arterial oxygen saturation 90%) before and after administration of 800 micrograms of fenoterol by a metered dose inhaler. The order in which treatments were applied was according to a Latin square design. RESULTS: Before inhalation of fenoterol hypoxaemia was associated with a significant increase in heart rate (8 beats/min) and QTc interval (15.6 ms). Under conditions of normoxaemia fenoterol caused a significant increase in heart rate (14.3 beats/min), systolic blood pressure (7.7 mm Hg), stroke volume (27.7 ml), cardiac index (1.6 1/min/m2), ejection fraction (11.48), and QTc interval (32.9 ms) and a fall in QS2I (-23.2 ms) and diastolic blood pressure (-8.4 mm Hg). Under conditions of hypoxaemia the changes after inhalation of fenoterol were similar to those recorded during normoxaemia; thus the effects of hypoxaemia and fenoterol were additive (heart rate 21.9 beats/min, QTc 43.5 ms with fenoterol and hypoxaemia). CONCLUSION: The chronotropic and electrophysiological effects of fenoterol were enhanced by conditions of hypoxaemia. PMID:1481183

Cardiovascular effects of pimobendan in healthy mature horses.

PubMed

Afonso, T; Giguère, S; Rapoport, G; Barton, M H; Coleman, A E

2016-05-01

Pimobendan is an inodilator used in dogs for the management of heart failure due to myxomatous valve disease or dilated cardiomyopathy. The lack of data regarding the effects of pimobendan in horses prevents the rational use of this drug. To determine the cardiovascular effects of pimobendan in healthy mature horses. Randomised experimental study. Five horses were fasted overnight prior to receiving i.v. pimobendan (0.25 mg/kg bwt), intragastric (i.g.) pimobendan (0.25 mg/kg bwt) or i.g. placebo with a washout period of one week between each administration. Horses were instrumented for the measurement of right ventricular (RV) minimum pressure, RV maximum pressure, RV end diastolic pressure, and maximum rate of increase and decrease in RV pressure before and 0.5, 1, 2, 4, and 8 h after drug administration. Arterial blood pressure, central venous pressure, cardiac output and heart rate were measured at the same time points. Data were expressed as a maximum percentage of change over baseline values. There were no adverse effects associated with administration of pimobendan. The percentage increase in heart rate was significantly greater for horses given pimobendan i.g. (33 ± 4%) and i.v. (36 ± 14%) than for those given a placebo (-2 ± 7%). The percentage increase in maximum rate of increase in RV pressure (35 ± 36%) and the percentage decrease in minimum pressure (47 ± 24%) and end diastolic pressure (34 ± 13%) were significantly greater in horses given pimobendan i.v. than in those given placebo. Other variables measured were not significantly different between treatment groups. Pimobendan administered i.v. has positive chronotropic and inotropic effects in healthy mature horses and warrants further investigation for the treatment of heart failure in horses. © 2015 EVJ Ltd.

Dopamine treatment does not need speed recovery of newborns from transient tachypnea.

PubMed

Guzoglu, Nilufer; Uras, Nurdan; Aksoy, Hatice T; Eras, Zeynep; Oguz, Serife S; Dilmen, Ugur

2016-05-01

Transient tachypnea of the newborn (TTN) results from inadequate neonatal lung fluid clearance. Low-dose dopamine induces natriuresis in the kidneys and it has been assumed that, at this low dosage, dopamine increases renal perfusion in critically ill patients. Medium doses have positive inotropic and chronotropic effects via increased β-receptor activation. Recent studies have demonstrated that dopamine stimulates the clearance of pulmonary edema. Furthermore, β-adrenergic agonists regulate Na+ channels and Na-K-ATPase activity in the pulmonary epithelium. This study investigated the effect of dopamine at different dosages on TTN treatment. A prospective controlled study examined 60 infants with TTN older than 34 weeks of gestation who required at least 24 h of O2 and nasal continuous positive airway pressure (nCPAP) treatment. The infants were randomized into three groups of 20: controls, infants treated with low-dose dopamine (3 μg/kg/min), and infants treated with a medium dose (5 μg/kg/min). The control and study groups were compared in terms of the requirement for mechanical ventilation, and the durations of nCPAP, oxygen requirement, and hospitalization. The requirement for mechanical ventilation, and durations of nCPAP, oxygen requirement, and hospitalization did not differ significantly among the three groups (P=0.54, 0.16 and 0.11, respectively). Dopamine treatment in low-moderate doses does not improve the outcome in TTN. Thus, further studies in this area are needed.

Chronic spinal cord stimulation modifies intrinsic cardiac synaptic efficacy in the suppression of atrial fibrillation

PubMed Central

Ardell, Jeffrey L.; Cardinal, René; Beaumont, Eric; Vermeulen, Michel; Smith, Frank M.; Armour, J. Andrew

2014-01-01

We sought to determine whether spinal cord stimulation (SCS) therapy, when applied chronically to canines, imparts long-lasting cardio-protective effects on neurogenic atrial tachyarrhythmia induction and, if so, whether its effects can be attributable to i) changes in intrinsic cardiac (IC) neuronal transmembrane properties vs ii) modification of their interneuronal stochastic interactivity that initiates such pathology. Data derived from canines subjected to long-term SCS [(group 1 studied after 3–4 weeks SCS; n=5) (group 2: studied 5 weeks SCS; n=11)] were compared to data derived from 10 control animals (including 4 sham SCS electrode implantations). During terminal studies conducted under anesthesia, chronotropic and inotropic responses to vagal nerve or stellate ganglion stimulation were similar in all 3 groups. Chronic SCS suppressed atrial tachyarrhythmia induction evoked by mediastinal nerve stimulation. When induced, arrhythmia durations were shortened (controls: median of 27s; SCS 3–4 weeks: median of 16s; SCS 5 weeks: median of 7s). Phasic and accommodating right atrial neuronal somata displayed similar passive and active membrane properties in vitro, whether derived from sham or either chronic SCS groups. Synaptic efficacy was differentially enhanced in accommodating (not phasic) IC neurons by chronic SCS. Taken together these data indicate that chronic SCS therapy modifies IC neuronal stochastic inter-connectivity in atrial fibrillation suppression by altering synaptic function without directly targeting the transmembrane properties of individual IC neuronal somata. PMID:25301713

Cardiac effects of electrically induced intrathoracic autonomic reflexes.

PubMed

Armour, J A

1988-06-01

Electrical stimulation of the afferent components in one cardiopulmonary nerve (the left vagosympathetic complex at a level immediately caudal to the origin of the left recurrent laryngeal nerve) in acutely decentralized thoracic autonomic ganglionic preparations altered cardiac chronotropism and inotropism in 17 of 44 dogs. Since these neural preparations were acutely decentralized, the effects were mediated presumably via intrathoracic autonomic reflexes. The lack of consistency of these reflexly generated cardiac responses presumably were due in part to anatomical variation of afferent axons in the afferent nerve stimulated. As stimulation of the afferent components in the same neural structure caudal to the heart (where cardiopulmonary afferent axons are not present) failed to elicit cardiac responses in any dog, it is presumed that when cardiac responses were elicited by the more cranially located stimulations, these were due to activation of afferent axons arising from the heart and (or) lungs. When cardiac responses were elicited, intramyocardial pressures in the right ventricular conus as well as the ventral and lateral walls of the left ventricle were augmented. Either bradycardia or tachycardia was elicited. Following hexamethonium administration no responses were produced, demonstrating that nicotonic cholinergic synaptic mechanisms were involved in these intrathoracic cardiopulmonary-cardiac reflexes. In six of the animals, when atropine was administered before hexamethonium, reflexly generated responses were attenuated. The same thing occurred when morphine was administered in four animals. In contrast, in four animals following administration of phentolamine, the reflexly generated changes were enhanced.(ABSTRACT TRUNCATED AT 250 WORDS)

Vitamins in Heart Failure: Friend or Enemy?

PubMed

Georgiopoulos, George; Chrysohoou, Christina; Vogiatzi, Georgia; Magkas, Nikolaos; Bournelis, Ippokratis; Bampali, Sofia; Gruson, Damien; Tousoulis, Dimitris

2017-01-01

The failing heart is characterized by a depleted metabolic energy reserve and the upregulation of several molecular mechanisms leading to cardiac hypertrophy, inflammation, fibrosis, angiogenesis, and apoptosis. Dietary or non-dietary supplementation of vitamins could potentially benefit energy balance. The objective of the present study was to evaluate all available information on vitamins supplementation in patients with chronic HF for possible beneficial effect on metabolic, inotropic, chronotropic and hemodynamic indices. We searched MEDLINE via Pubmed by using the following terms: "chronic heart failure" OR "cardiomyopathy" AND "vitamins", "vitamin A", "B complex vitamins", "vitamin C", "ascorbic acid", "vitamin D", "retinol", "vitamin E", "thiamine", "riboflavin", "niacin", "pyridoxine", "cobalamin", "folate", "pantothenic acid", "biotin", "tocopherol" and combinations of them. Data regarding supplementation of micronutrients in HF for most vitamins were sparse, and the inference about cardiovascular outcomes was obscured by the heterogeneity of studies, high inherent morbidity, and mortality of this group of high-risk patients, limited sample sizes in certain studies, unclear design and lack of head to head comparisons. Most vitamins in human trials failed to offer survival, or robust beneficial effect. Mostly indirect favorable evidence is derived from patients with deficiencies of certain micronutrients rather than their ad hoc supplementation. While vitamins and micronutrients are promising compounds for optimizing myocardial metabolism and homeostasis in HF, additional randomized clinical trials of larger scale are warranted to demonstrate the benefits of their supplementation in this high risk group of patients. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Effects of thyroid hormones on the heart.

PubMed

Vargas-Uricoechea, Hernando; Bonelo-Perdomo, Anilsa; Sierra-Torres, Carlos Hernán

2014-01-01

Thyroid hormones have a significant impact on heart function, mediated by genomic and non-genomic effects. Consequently, thyroid hormone deficiencies, as well as excesses, are expected to result in profound changes in cardiac function regulation and cardiovascular hemodynamics. Thyroid hormones upregulate the expression of the sarcoplasmic reticulum calcium-activated ATPase and downregulate the expression of phospholamban. Overall, hyperthyroidism is characterized by an increase in resting heart rate, blood volume, stroke volume, myocardial contractility, and ejection fraction. The development of "high-output heart failure" in hyperthyroidism may be due to "tachycardia-mediated cardiomyopathy". On the other hand, in a hypothyroid state, thyroid hormone deficiency results in lower heart rate and weakening of myocardial contraction and relaxation, with prolonged systolic and early diastolic times. Cardiac preload is decreased due to impaired diastolic function. Cardiac afterload is increased, and chronotropic and inotropic functions are reduced. Subclinical thyroid dysfunction is relatively common in patients over 65 years of age. In general, subclinical hypothyroidism increases the risk of coronary heart disease (CHD) mortality and CHD events, but not of total mortality. The risk of CHD mortality and atrial fibrillation (but not other outcomes) in subclinical hyperthyroidism is higher among patients with very low levels of thyrotropin. Finally, medications such as amiodarone may induce hypothyroidism (mediated by the Wolff-Chaikoff), as well as hyperthyroidism (mediated by the Jod-Basedow effect). In both instances, the underlying cause is the high concentration of iodine in this medication. Copyright © 2014 Sociedad Española de Arteriosclerosis. Published by Elsevier España. All rights reserved.

Real-life indications to ivabradine treatment for heart rate optimization in patients with chronic systolic heart failure.

PubMed

Tondi, Lara; Fragasso, Gabriele; Spoladore, Roberto; Pinto, Giuseppe; Gemma, Marco; Slavich, Massimo; Godino, Cosmo; Salerno, Anna; Montanaro, Claudia; Margonato, Alberto

2018-05-11

: Ivabradine is a selective and specific inhibitor of If current. With its pure negative chronotropic action, it is recommended by European Society of Cardiology and American College of Cardiology/American Heart Association guidelines in symptomatic heart failure patients (NYHA ≥ 2) with ejection fraction 35% or less, sinus rhythm and heart rate (HR) at least 70 bpm, despite maximally titrated β-blocker therapy. Data supporting this indication mainly derive from the SHIFT study, in which ivabradine reduced the combined endpoint of mortality and hospitalization, despite the fact that only 26% of patients enrolled were on optimal β-blocker doses. The aim of the present analysis is to establish the real-life eligibility for ivabradine in a population of patients with systolic heart failure, regularly attending a single heart failure clinic and treated according to guideline-directed medical therapy (GDMT). The clinical cards of 308 patients with heart failure with reduced ejection fraction (HFrEF) through a 68-month period of observation were retrospectively analyzed. GDMT, including β-blocker up-titration to maximal tolerated dose, was implemented during consecutive visits at variable intervals. Demographic, clinical and echocardiographic data were collected at each visit, together with 12-leads ECG and N-terminal pro-B-type natriuretic peptide levels. Out of 308 analyzed HFrEF patients, 220 (71%) were on effective β-blocker therapy, up-titrated to effective/maximal tolerated dose (55 ± 28% of maximal dose) (HR 67 ± 10 bpm). Among the remaining 88 patients, 10 (3.2%) were on maximally tolerated β blocker and ivabradine; 21 patients (6.8%), despite being on maximal tolerated β-blocker dose, had still HR ≥70 bpm, ejection fraction 35% or less and were symptomatic NYHA ≥2, being therefore eligible for ivabradine treatment. The remaining 57 (18%) patients were not on β blocker due to either intolerance or major contraindications. Among them, 13 (4%) were taking ivabradine alone. Of the final 44 (14%) patients, 27 (9%) showed an inadequate HR control (74 ± 6 bpm). Of these, only eight (3%) patients resulted to be eligible for ivabradine introduction according to HR and ejection fraction parameters. Overall ivabradine was indicated in 52 patients (16.8%) out of 308 enrolled.In conclusion, in a carefully managed population of patients with moderate and stable HFrEF, in which optimal GDMT is properly attained, indication to ivabradine treatment is around 17%.

Cirrhotic cardiomyopathy

PubMed Central

Ruiz-del-Árbol, Luis; Serradilla, Regina

2015-01-01

During the course of cirrhosis, there is a progressive deterioration of cardiac function manifested by the disappearance of the hyperdynamic circulation due to a failure in heart function with decreased cardiac output. This is due to a deterioration in inotropic and chronotropic function which takes place in parallel with a diastolic dysfunction and cardiac hypertrophy in the absence of other known cardiac disease. Other findings of this specific cardiomyopathy include impaired contractile responsiveness to stress stimuli and electrophysiological abnormalities with prolonged QT interval. The pathogenic mechanisms of cirrhotic cardiomyopathy include impairment of the b-adrenergic receptor signalling, abnormal cardiomyocyte membrane lipid composition and biophysical properties, ion channel defects and overactivity of humoral cardiodepressant factors. Cirrhotic cardiomyopathy may be difficult to determine due to the lack of a specific diagnosis test. However, an echocardiogram allows the detection of the diastolic dysfunction and the E/e′ ratio may be used in the follow-up progression of the illness. Cirrhotic cardiomyopathy plays an important role in the pathogenesis of the impairment of effective arterial blood volume and correlates with the degree of liver failure. A clinical consequence of cardiac dysfunction is an inadequate cardiac response in the setting of vascular stress that may result in renal hypoperfusion leading to renal failure. The prognosis is difficult to establish but the severity of diastolic dysfunction may be a marker of mortality risk. Treatment is non-specific and liver transplantation may normalize the cardiac function. PMID:26556983

Synaptic delay in the heart: an ionophoretic study.

PubMed Central

Hill-Smith, I; Purves, R D

1978-01-01

1. Neurotransmitters were applied ionophoretically to spontaneously beating clusters of ventricular muscle cells cultured from neonatal rats. 2. Acetylcholine or its analogue carbachol produced hyperpolarization and decreased the rate of spontaneous beating. These responses had minimum latencies of about 250 msec and total durations of 6-12 sec. 3. Noradrenaline, adrenaline or isoprenaline increased the rate of spontaneous beating. The minimum latency for this effect was 3-6 sec. Following a single brief pulse the rate remained elevated for 2 min or more. 4. Chronotropic responses of intact atria from adult rats to stimulation of the autonomic nerves were of similar time course to responses of the cultured muscle cells. 5. Calculations based on the theory of diffusion showed that access of drugs to their receptors could not be rate-limiting for the observed responses, unless a diffusion barrier of rather special properties was postulated. A number of other explanations for the long latencies have been ruled out; these are most likely to be due to some physical or chemical process occurring in or under the cell membrane. 6. Attempts to mimic responses to catecholamines by intracellular application of cyclic AMP were unsuccessful, perhaps because the release of nucleotide from the pipettes was insufficient. A theoretical treatment suggests that ionophoretic efflux of anions might be greatly diminished by the opposing electro-osmotic flux. PMID:209176

The electrophysiological effects of nicotinic and electrical stimulation of intrinsic cardiac ganglia in the absence of extrinsic autonomic nerves in the rabbit heart.

PubMed

Allen, Emily; Coote, John H; Grubb, Blair D; Batten, Trevor Fc; Pauza, Dainius H; Ng, G André; Brack, Kieran E

2018-05-22

The intrinsic cardiac nervous system (ICNS) is a rich network of cardiac nerves that converge to form distinct ganglia and extend across the heart and is capable of influencing cardiac function. To provide a picture of the neurotransmitter/neuromodulator profile of the rabbit ICNS and determine the action of spatially divergent ganglia on cardiac electrophysiology. Nicotinic or electrical stimulation was applied at discrete sites of the intrinsic cardiac nerve plexus in the Langendorff perfused rabbit heart. Functional effects on sinus rate and atrioventricular conduction were measured. Immunohistochemistry for choline acetyltransferase (ChAT), tyrosine hydroxylase (TH) and/or neuronal nitric oxide synthase (nNOS) was performed on whole-mount preparations. Stimulation within all ganglia produced either bradycardia, tachycardia or a biphasic brady-tachycardia. Electrical stimulation of the right atrial (RA) and right neuronal cluster (RNC) regions produced the greatest chronotropic responses. Significant prolongation of atrioventricular conduction (AVC) was predominant at the pulmonary vein-caudal vein region (PVCV). Neurons immunoreactive (IR) only for ChAT, or TH or nNOS were consistently located within the limits of the hilum and at the roots of the right cranial and right pulmonary veins. ChAT-IR neurons were most abundant (1946±668 neurons). Neurons IR solely for nNOS were distributed within ganglia. Stimulation of intrinsic ganglia, shown to be of phenotypic complexity but predominantly of cholinergic nature, indicates that clusters of neurons are capable of independent selective effects on cardiac electrophysiology, therefore providing a potential therapeutic target for the prevention and treatment of cardiac disease. Copyright © 2018. Published by Elsevier Inc.

Adrenergic and cholinergic activity contributes to the cardiovascular effects of lionfish (Pterois volitans) venom.

PubMed

Church, Jarrod E; Hodgson, Wayne C

2002-06-01

The aim of the present study was to further investigate the cardiovascular activity of Pterois volitans crude venom. Venom (0.6-18 microg protein/ml) produced dose- and endothelium-dependent relaxation in porcine coronary arteries that was potentiated by atropine (10nM), but significantly attenuated by the nitric oxide synthase inhibitor N(omega)-nitro-L-arginine (NOLA; 0.1mM), by prior exposure of the tissue to stonefish antivenom (SFAV, 3 units/ml, 10 min), or by removal of extracellular Ca(2+). In rat paced left atria, venom (10 microg protein/ml) produced a decrease, followed by an increase, in contractile force. Atropine (0.5 microM) abolished the decrease in force and potentiated the increase. Propranolol (5 microM) did not affect the decrease in force but significantly attenuated the increase. In spontaneously beating right atria, venom (10 microg protein/ml) produced an increase in rate that was significantly attenuated by propranolol (5 microM). Prior incubation with SFAV (0.3 units/microg protein, 10 min) abolished both the inotropic and chronotropic responses to venom. In the anaesthetised rat, venom (100 micro protein/kg, i.v.) produced a pressor response, followed by a sustained depressor response. Atropine (1mg/kg, i.v.) potentiated the pressor response. The further addition of prazosin (50 microg/kg, i.v.) restored the original response to venom. Prior administration of SFAV (100 units/kg, i.v., 10 min) significantly attenuated the in vivo response to venom. It is concluded that P. volitans venom produces its cardiovascular effects primarily by acting on muscarinic cholinergic receptors and adrenoceptors. As SFAV neutralised many of the effects of P. volitans venom, we suggest that the two venoms share a similar component(s). Copright 2002 Elsevier Science Ltd.

Adrenergic Stress Protection of Human iPS Cell-Derived Cardiomyocytes by Fast Kv7.1 Recycling

PubMed Central

Piccini, Ilaria; Fehrmann, Edda; Frank, Stefan; Müller, Frank U.; Greber, Boris; Seebohm, Guiscard

2017-01-01

The fight-or-flight response (FFR), a physiological acute stress reaction, involves positive chronotropic and inotropic effects on heart muscle cells mediated through β-adrenoceptor activation. Increased systolic calcium is required to enable stronger heart contractions whereas elevated potassium currents are to limit the duration of the action potentials and prevent arrhythmia. The latter effect is accomplished by an increased functional activity of the Kv7.1 channel encoded by KCNQ1. Current knowledge, however, does not sufficiently explain the full extent of rapid Kv7.1 activation and may hence be incomplete. Using inducible genetic KCNQ1 complementation in KCNQ1-deficient human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs), we here reinvestigate the functional role of Kv7.1 in adapting human CMs to adrenergic stress. Under baseline conditions, Kv7.1 was barely detectable at the plasma membrane of hiPSC-CMs, yet it fully protected these from adrenergic stress-induced beat-to-beat variability of repolarization and torsade des pointes-like arrhythmia. Furthermore, isoprenaline treatment increased field potential durations specifically in KCNQ1-deficient CMs to cause these adverse macroscopic effects. Mechanistically, we find that the protective action by Kv7.1 resides in a rapid translocation of channel proteins from intracellular stores to the plasma membrane, induced by adrenergic signaling. Gene silencing experiments targeting RAB GTPases, mediators of intracellular vesicle trafficking, showed that fast Kv7.1 recycling under acute stress conditions is RAB4A-dependent.Our data reveal a key mechanism underlying the rapid adaptation of human cardiomyocytes to adrenergic stress. These findings moreover aid to the understanding of disease pathology in long QT syndrome and bear important implications for safety pharmacological screening. PMID:28959214

The effects of lower than conventional doses of oral nadolol on relative beta 1/beta 2-adrenoceptor blockade.

PubMed

Wheeldon, N M; McDevitt, D G; Lipworth, B J

1994-08-01

1. The aim of the present study was to evaluate the relative beta 1/beta 2 antagonist selectivity of the beta-adrenoceptor blocker nadolol, in lower than conventional clinical doses. 2. Eight normal volunteers received single oral doses of either placebo (PL), nadolol 5 mg (N5), 20 mg (N20) or 80 mg (N80) in a single-blind, randomised crossover design. beta 1-adrenoceptor antagonism was assessed by attenuation of exercise tachycardia, and beta 2-adrenoceptor blockade by effects on salbutamol-induced chronotropic, hypokalaemic and finger tremor responses. The relative percentage attenuation of beta 2 and beta 1-mediated responses was calculated and expressed as beta 2:beta 1 selectivity ratios. 3. Nadolol produced dose-related reductions in exercise tachycardia in keeping with increasing beta 1-adrenoceptor blockade; mean % reduction (95% CI) compared with placebo: N5 10.7 (6.6 to 14.8), N20 21.4 (17.3 to 25.4), N80 38.9 (34.8 to 42.9). However, even the lowest dose of nadolol (5 mg) produced almost complete blunting of beta 2-mediated effects and significantly increase exercise hyperkalaemia; peak exercise hyperkalaemia (mmol l-1) (means and 95% CI): PL 4.88 (4.68 to 5.07), N5 5.36 (5.17 to 5.55), N20 5.48 (5.28 to 5.67), N80 5.42 (5.22 to 5.61). beta 2:beta 1 selectivity ratios significantly increased as the dose of nadolol was reduced. 4. These data suggest that whereas in the clinical dose range nadolol behaves as a non-selective beta-adrenoceptor antagonist, as the dose is reduced this drug demonstrates an increasing degree of selectivity for the beta 2-adrenoceptor.(ABSTRACT TRUNCATED AT 250 WORDS)

Short-Term Thyroid Hormone Excess Affects the Heart but Does not Affect Adrenal Activity in Rats

PubMed Central

Szkudlarek, Ariani Cavazzani; Aldenucci, Bruno; Miyagui, Nelson Itiro; Silva, Ilana Kassouf; Moraes, Rosana Nogueira; Ramos, Helton Estrela; Fogaça, Rosalva Tadeu Hochmuller

2014-01-01

Background Hyperthyroidism (Hy) exerts a broad range of influences on a variety of physiological parameters. Its disruptive effect on cardiovascular system is one of its most remarkable impacts. Moreover, Hy has been clinically associated with stress - induced hyperactivation of the hypothalamic-pituitary-adrenal axis. Objective Evaluate the impact of short-term Hy on cardiac performance and adrenal activity of rats. Methods Induction of Hy in Wistar rats through injections of T3 (150 µg/kg) for 10 days (hyperthyroid group - HG) or vehicle (control group). The cardiovascular performance was evaluated by: echocardiography (ECHO); heart weight/body weight (mg/gr) ratio; contractility of isolated papillary muscles (IPM) and direct measurement of blood pressures. Adrenal activity was evaluated by adrenal weight/body weight (mg/gr) ratio and 24-hour fecal corticosterone (FC) levels on the, 5th and 10th days of T3 treatment. Results In HG, the ECHO showed reduction of the End Systolic and End Diastolic Volumes, Ejection, Total Diastolic and Isovolumic Relaxation Times, Diastolic and Systolic Areas and E/A ratio. Heart Rate, Ejection Fraction and Cardiac Output increased. The heart weight/body weight ratio was higher. Similarly, in IPM, the maximum rate of force decay during relaxation was higher in all extracellular calcium concentrations. Systolic blood pressure (SBP) levels were higher. (p ≤ 0.05). On the other hand, there was no difference in the adrenal weight/body weight ratio or in the 24-hour FC levels. Conclusions Hy induces positive inotropic, chronotropic and lusitropic effects on the heart by direct effects of T3 and increases SBP. Those alterations are not correlated with changes in the adrenal activity. PMID:24676225

Adrenergic Stress Protection of Human iPS Cell-Derived Cardiomyocytes by Fast Kv7.1 Recycling.

PubMed

Piccini, Ilaria; Fehrmann, Edda; Frank, Stefan; Müller, Frank U; Greber, Boris; Seebohm, Guiscard

2017-01-01

The fight-or-flight response (FFR), a physiological acute stress reaction, involves positive chronotropic and inotropic effects on heart muscle cells mediated through β-adrenoceptor activation. Increased systolic calcium is required to enable stronger heart contractions whereas elevated potassium currents are to limit the duration of the action potentials and prevent arrhythmia. The latter effect is accomplished by an increased functional activity of the K v 7.1 channel encoded by KCNQ1 . Current knowledge, however, does not sufficiently explain the full extent of rapid K v 7.1 activation and may hence be incomplete. Using inducible genetic KCNQ1 complementation in KCNQ1 -deficient human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs), we here reinvestigate the functional role of K v 7.1 in adapting human CMs to adrenergic stress. Under baseline conditions, K v 7.1 was barely detectable at the plasma membrane of hiPSC-CMs, yet it fully protected these from adrenergic stress-induced beat-to-beat variability of repolarization and torsade des pointes -like arrhythmia. Furthermore, isoprenaline treatment increased field potential durations specifically in KCNQ1-deficient CMs to cause these adverse macroscopic effects. Mechanistically, we find that the protective action by K v 7.1 resides in a rapid translocation of channel proteins from intracellular stores to the plasma membrane, induced by adrenergic signaling. Gene silencing experiments targeting RAB GTPases, mediators of intracellular vesicle trafficking, showed that fast K v 7.1 recycling under acute stress conditions is RAB4A-dependent.Our data reveal a key mechanism underlying the rapid adaptation of human cardiomyocytes to adrenergic stress. These findings moreover aid to the understanding of disease pathology in long QT syndrome and bear important implications for safety pharmacological screening.

Metronidazole and 5-aminosalicylic acid enhance the contractile activity of histaminergic agonists on the guinea-pig isolated ileum

DOE Office of Scientific and Technical Information (OSTI.GOV)

Winbery, S.L.; Barker, L.A.

1986-03-01

The effects of metronidazole and 5-aminosalicylic acid (5-ASA) on histamine receptor-effector systems in the small intestine and right atrium of the guinea pig were studied. In an apparently all-or-none manner, both caused a sinistral shift in dose-response curves for the phasic component of the contractile response to histamine at H1 receptors on the ileum. In the presence of either, the EC50 value for histamine was reduced from 0.07 to about 0.03 microM. Similarly, in an apparently all-or-none fashion, both produced an elevation in the dose-response curve for the actions of dimaprit at H2-receptors in the ileum; the response to allmore » doses was increased about 30% with no significant change in the EC50 value. Metronidazole and 5-ASA did not alter dose-response curves for the tonic contractile response to histamine or curves generated by the cumulative addition of histamine. Also, neither altered the positive chronotropic response on isolated right atria or the phasic contractile response on isolated segments of jejunum and duodenum to histamine or dimaprit. Likewise, neither altered dose-response curves for the direct action of carbamylcholine at muscarinic receptors or for the indirect actions of dimethylphenylpiperazinium on the ileum. The effects of 5-ASA or metronidazole on the response to histamine could be prevented as well as reversed by scopolamine or tetrodotoxin. The results suggest that metronidazole and 5-ASA enhance the actions of histamine and dimaprit on the ileum by an action on myenteric plexus neurons.« less

Chronic baroreflex activation restores spontaneous baroreflex control and variability of heart rate in obesity-induced hypertension

PubMed Central

Iliescu, Radu; Tudorancea, Ionut; Irwin, Eric D.

2013-01-01

The sensitivity of baroreflex control of heart rate is depressed in subjects with obesity hypertension, which increases the risk for cardiac arrhythmias. The mechanisms are not fully known, and there are no therapies to improve this dysfunction. To determine the cardiovascular dynamic effects of progressive increases in body weight leading to obesity and hypertension in dogs fed a high-fat diet, 24-h continuous recordings of spontaneous fluctuations in blood pressure and heart rate were analyzed in the time and frequency domains. Furthermore, we investigated whether autonomic mechanisms stimulated by chronic baroreflex activation and renal denervation—current therapies in patients with resistant hypertension, who are commonly obese—restore cardiovascular dynamic control. Increases in body weight to ∼150% of control led to a gradual increase in mean arterial pressure to 17 ± 3 mmHg above control (100 ± 2 mmHg) after 4 wk on the high-fat diet. In contrast to the gradual increase in arterial pressure, tachycardia, attenuated chronotropic baroreflex responses, and reduced heart rate variability were manifest within 1–4 days on high-fat intake, reaching 130 ± 4 beats per minute (bpm) (control = 86 ± 3 bpm) and ∼45% and <20%, respectively, of control levels. Subsequently, both baroreflex activation and renal denervation abolished the hypertension. However, only baroreflex activation effectively attenuated the tachycardia and restored cardiac baroreflex sensitivity and heart rate variability. These findings suggest that baroreflex activation therapy may reduce the risk factors for cardiac arrhythmias as well as lower arterial pressure. PMID:23913707

Deletion of neurturin impairs development of cholinergic nerves and heart rate control in postnatal mouse hearts.

PubMed

Downs, Anthony M; Jalloh, Hawa B; Prater, Kayla J; Fregoso, Santiago P; Bond, Cherie E; Hampton, Thomas G; Hoover, Donald B

2016-05-01

The neurotrophic factor neurturin is required for normal cholinergic innervation of adult mouse heart and bradycardic responses to vagal stimulation. Our goals were to determine effects of neurturin deletion on development of cardiac chronotropic and dromotropic functions, vagal baroreflex response, and cholinergic nerve density in nodal regions of postnatal mice. Experiments were performed on postnatal C57BL/6 wild-type (WT) and neurturin knockout (KO) mice. Serial electrocardiograms were recorded noninvasively from conscious pups using an ECGenie apparatus. Mice were treated with atenolol to evaluate and block sympathetic effects on heart rate (HR) and phenylephrine (PE) to stimulate the baroreflex. Immunohistochemistry was used to label cholinergic nerves in paraffin sections. WT and KO mice showed similar age-dependent increases in HR and decreases in PR interval between postnatal days (P) 2.5 and 21. Treatment with atenolol reduced HR significantly in WT and KO pups at P7.5. PE caused a reflex bradycardia that was significantly smaller in KO pups. Cholinergic nerve density was significantly less in nodal regions of P7.5 KO mice. We conclude that cholinergic nerves have minimal influence on developmental changes in HR and PR, QRS, and QTc intervals in mouse pups. However, cholinergic nerves mediate reflex bradycardia by 1 week postnatally. Deletion of neurturin impairs cholinergic innervation of the heart and the vagal efferent component of the baroreflex early during postnatal development. © 2016 The Authors. Physiological Reports published by Wiley Periodicals, Inc. on behalf of the American Physiological Society and The Physiological Society.

[Cycle ergometer stress testing for identification of significant coronary artery disease: improved accuracy by the use of chronotropic reserve adjustment of ST-segment depression].

PubMed

Palmieri, Vittorio; Pezzullo, Salvatore; Arezzi, Emma; Russo, Cesare; Martino, Stefania; D'Andrea, Claudia; Cassese, Salvatore; Celentano, Aldo

2008-09-01

Diagnostic reliability of indexations of peak exercise ST-segment depression (deltaST) for heart rate reserve (HRi) or chronotropic reserve (CR) to identify significant coronary artery disease (CAD) by bicycle exercise testing has not been evaluated previously. Upright bicycle exercise testing (25 W increment every 3 min) was performed in consecutive patients in primary prevention with at least one of the following criteria: history of exercise-induced chest discomfort and cardiovascular risk factors; overt peripheral arterial disease; type 2 diabetes associated with two or more additional cardiovascular risk factors. Coronary angiography was performed to define significant CAD (stenosis > or = 70% of the main coronary arteries or of their major branches, or isolated left main stenosis > or = 50%, or two or more stenoses 50-69%). Duke angina index was used to grade exercise-induced chest pain; deltaST, ST/HRi and ST/CR were calculated at peak exercise; three different criteria for the definition of inducible myocardial ischemia were tested versus significant CAD: peak deltaST > or =100 microV, ST/HRi > 1.69 microV/b/min or ST/CR > 1.76 microV/%. Of the study sample (n = 46), 40% had typical angina; during stress test 80% showed deltaST > or = 100 microV; 76% had ST/HRi > 1.69 microV/b/min; 62% had ST/CR >1.76 microV/%. Diagnostic accuracy of deltaST > or = 100 microV, of ST/HRi > 1.69 micro5V/b/min, and of ST/CR > 1.76 microV/% were 78%, 72%, and 89% respectively (p < 0.001 for the difference in diagnostic performance). ST/CR > 1.76 microV/% showed the highest diagnostic accuracy both in patients with submaximal exercise (96%) and in women (92%). Similarly, ST/CR >1.76 microV/% was associated with the highest diagnostic accuracy both in patients with maximal exercise (78%) and in men (88%). Analyses of the ROC curve revealed that ST/CR was associated with the greatest area under the curve, and a population-specific cut-off of 1.77 microV/% was associated with a sensitivity of 88% and a specificity of 90%. Our pilot study suggests that in patients undergoing bicycle stress testing for differential diagnosis or screening of significant CAD, and with moderate-to-high pre-test probability, the use of ST/CR > 1.76 microV/% may provide elevated sensitivity and specificity, and the best diagnostic accuracy, which was consistent in patients with submaximal exercise test and in women.

Distinct physiological effects of β1- and β2-adrenoceptors in mouse ventricular myocytes: insights from a compartmentalized mathematical model.

PubMed

Rozier, Kelvin; Bondarenko, Vladimir E

2017-05-01

The β 1 - and β 2 -adrenergic signaling systems play different roles in the functioning of cardiac cells. Experimental data show that the activation of the β 1 -adrenergic signaling system produces significant inotropic, lusitropic, and chronotropic effects in the heart, whereas the effects of the β 2 -adrenergic signaling system is less apparent. In this paper, a comprehensive compartmentalized experimentally based mathematical model of the combined β 1 - and β 2 -adrenergic signaling systems in mouse ventricular myocytes is developed to simulate the experimental findings and make testable predictions of the behavior of the cardiac cells under different physiological conditions. Simulations describe the dynamics of major signaling molecules in different subcellular compartments; kinetics and magnitudes of phosphorylation of ion channels, transporters, and Ca 2+ handling proteins; modifications of action potential shape and duration; and [Ca 2+ ] i and [Na + ] i dynamics upon stimulation of β 1 - and β 2 -adrenergic receptors (β 1 - and β 2 -ARs). The model reveals physiological conditions when β 2 -ARs do not produce significant physiological effects and when their effects can be measured experimentally. Simulations demonstrated that stimulation of β 2 -ARs with isoproterenol caused a marked increase in the magnitude of the L-type Ca 2+ current, [Ca 2+ ] i transient, and phosphorylation of phospholamban only upon additional application of pertussis toxin or inhibition of phosphodiesterases of type 3 and 4. The model also made testable predictions of the changes in magnitudes of [Ca 2+ ] i and [Na + ] i fluxes, the rate of decay of [Na + ] i concentration upon both combined and separate stimulation of β 1 - and β 2 -ARs, and the contribution of phosphorylation of PKA targets to the changes in the action potential and [Ca 2+ ] i transient. Copyright © 2017 the American Physiological Society.

Central estrogenic pathways protect against the depressant action of acute nicotine on reflex tachycardia in female rats

DOE Office of Scientific and Technical Information (OSTI.GOV)

El-Mas, Mahmoud M., E-mail: mahelm@hotmail.com; Fouda, Mohamed A.; El-gowilly, Sahar M.

We have previously shown that acute exposure of male rats to nicotine preferentially attenuates baroreceptor-mediated control of reflex tachycardia in contrast to no effect on reflex bradycardia. Here, we investigated whether female rats are as sensitive as their male counterparts to the baroreflex depressant effect of nicotine and whether this interaction is modulated by estrogen. Baroreflex curves relating reflex chronotropic responses evoked by i.v. doses (1–16 μg/kg) of phenylephrine (PE) or sodium nitroprusside (SNP), were constructed in conscious freely moving proestrus, ovariectomized (OVX), and estrogen (50 μg/kg/day s.c., 5 days)-replaced OVX (OVXE{sub 2}) rats. Slopes of the curves were takenmore » as a measure of baroreflex sensitivity (BRS{sub PE} and BRS{sub SNP}). Nicotine (100 μg/kg i.v.) reduced BRS{sub SNP} in OVX rats but not in proestrus or OVXE{sub 2} rats. The attenuation of reflex tachycardia by nicotine was also evident in diestrus rats, which exhibited plasma estrogen levels similar to those of OVX rats. BRS{sub PE} was not affected by nicotine in all rat preparations. Experiments were then extended to determine whether central estrogenic receptors modulate the nicotine–BRS{sub SNP} interaction. Intracisteral (i.c.) treatment of OVX rats with estrogen sulfate (0.2 μg/rat) abolished the BRS{sub SNP} attenuating effect of i.v. nicotine. This protective effect of estrogen disappeared when OVX rats were pretreated with i.c. ICI 182,780 (50 μg/rat, selective estrogen receptor antagonist). Together, these findings suggest that central neural pools of estrogen receptors underlie the protection offered by E{sub 2} against nicotine-induced baroreceptor dysfunction in female rats. -- Highlights: ► Estrogen protects against the depressant effect of nicotine on reflex tachycardia. ► The baroreflex response and estrogen status affect the nicotine–BRS interaction. ► The protection offered by estrogen is mediated via central estrogen receptors.« less

A device for rapid and quantitative measurement of cardiac myocyte contractility

NASA Astrophysics Data System (ADS)

Gaitas, Angelo; Malhotra, Ricky; Li, Tao; Herron, Todd; Jalife, José

2015-03-01

Cardiac contractility is the hallmark of cardiac function and is a predictor of healthy or diseased cardiac muscle. Despite advancements over the last two decades, the techniques and tools available to cardiovascular scientists are limited in their utility to accurately and reliably measure the amplitude and frequency of cardiomyocyte contractions. Isometric force measurements in the past have entailed cumbersome attachment of isolated and permeabilized cardiomyocytes to a force transducer followed by measurements of sarcomere lengths under conditions of submaximal and maximal Ca2+ activation. These techniques have the inherent disadvantages of being labor intensive and costly. We have engineered a micro-machined cantilever sensor with an embedded deflection-sensing element that, in preliminary experiments, has demonstrated to reliably measure cardiac cell contractions in real-time. Here, we describe this new bioengineering tool with applicability in the cardiovascular research field to effectively and reliably measure cardiac cell contractility in a quantitative manner. We measured contractility in both primary neonatal rat heart cardiomyocyte monolayers that demonstrated a beat frequency of 3 Hz as well as human embryonic stem cell-derived cardiomyocytes with a contractile frequency of about 1 Hz. We also employed the β-adrenergic agonist isoproterenol (100 nmol l-1) and observed that our cantilever demonstrated high sensitivity in detecting subtle changes in both chronotropic and inotropic responses of monolayers. This report describes the utility of our micro-device in both basic cardiovascular research as well as in small molecule drug discovery to monitor cardiac cell contractions.

Biological pacemaker created by minimally invasive somatic reprogramming in pigs with complete heart block

PubMed Central

Hu, Yu-Feng; Dawkins, James Frederick; Cho, Hee Cheol; Marbán, Eduardo; Cingolani, Eugenio

2016-01-01

Somatic reprogramming by reexpression of the embryonic transcription factor T-box 18 (TBX18) converts cardiomyocytes into pacemaker cells. We hypothesized that this could be a viable therapeutic avenue for pacemaker-dependent patients afflicted with device-related complications, and therefore tested whether adenoviral TBX18 gene transfer could create biological pacemaker activity in vivo in a large-animal model of complete heart block. Biological pacemaker activity, originating from the intramyocardial injection site, was evident in TBX18-transduced animals starting at day 2 and persisted for the duration of the study (14 days) with minimal backup electronic pacemaker use. Relative to controls transduced with a reporter gene, TBX18-transduced animals exhibited enhanced autonomic responses and physiologically superior chronotropic support of physical activity. Induced sinoatrial node cells could be identified by their distinctive morphology at the site of injection in TBX18-transduced animals, but not in controls. No local or systemic safety concerns arose. Thus, minimally invasive TBX18 gene transfer creates physiologically relevant pacemaker activity in complete heart block, providing evidence for therapeutic somatic reprogramming in a clinically relevant disease model. PMID:25031269

Loss of the transcription factor Meis1 prevents sympathetic neurons target-field innervation and increases susceptibility to sudden cardiac death

PubMed Central

Bouilloux, Fabrice; Thireau, Jérôme; Ventéo, Stéphanie; Farah, Charlotte; Karam, Sarah; Dauvilliers, Yves; Valmier, Jean; Copeland, Neal G; Jenkins, Nancy A; Richard, Sylvain; Marmigère, Frédéric

2016-01-01

Although cardio-vascular incidents and sudden cardiac death (SCD) are among the leading causes of premature death in the general population, the origins remain unidentified in many cases. Genome-wide association studies have identified Meis1 as a risk factor for SCD. We report that Meis1 inactivation in the mouse neural crest leads to an altered sympatho-vagal regulation of cardiac rhythmicity in adults characterized by a chronotropic incompetence and cardiac conduction defects, thus increasing the susceptibility to SCD. We demonstrated that Meis1 is a major regulator of sympathetic target-field innervation and that Meis1 deficient sympathetic neurons die by apoptosis from early embryonic stages to perinatal stages. In addition, we showed that Meis1 regulates the transcription of key molecules necessary for the endosomal machinery. Accordingly, the traffic of Rab5+ endosomes is severely altered in Meis1-inactivated sympathetic neurons. These results suggest that Meis1 interacts with various trophic factors signaling pathways during postmitotic neurons differentiation. DOI: http://dx.doi.org/10.7554/eLife.11627.001 PMID:26857994

Single dosing comparison of the relative cardiac beta 1/beta 2 activity of inhaled fenoterol and salbutamol in normal subjects.

PubMed Central

Newnham, D M; Wheeldon, N M; Lipworth, B J; McDevitt, D G

1993-01-01

BACKGROUND--The aim of the present study was to compare the dose related effects of fenoterol and salbutamol on cardiac beta 1 and beta 2 receptors using the beta 1 selective antagonist atenolol, in order to dissect out relative beta 1/beta 2 mediated responses. METHODS--Fourteen normal volunteers were randomised to receive pretreatment with either atenolol 25 mg or placebo, followed by inhaled fenoterol or salbutamol in equal doses by weight (cumulative doses of 1 mg and 4 mg). Measurements were made 30 minutes after inhaling each dose of beta 2 agonist. Values (mean and 95% CI) were expressed as a change from baseline. RESULTS--At 4 mg fenoterol produced equivalent falls in serum potassium and increases in tremor to salbutamol. The mean (95% CI) increase in heart rate (beats/min) with fenoterol at 4 mg after placebo was 47 (41-53) and after atenolol was 34 (28-40), with values for salbutamol being 46 (40-52) after placebo and 30 (24-36) after atenolol. The inotropic response (stroke distance) after atenolol at the 4 mg dose was 5.0 (3.9-6.1) cm for fenoterol and 4.7 (3.5-5.9) cm for salbutamol. There were no significant differences in heart rate or stroke distance response between the two drugs after either placebo or atenolol. Furthermore, ECG effects (Q-Tc and T wave) of fenoterol and salbutamol were comparable at both doses. CONCLUSIONS--These results show that there is no difference in the respective chronotropic or inotropic activities of fenoterol and salbutamol on cardiac beta 1 or beta 2 receptors when given at higher than conventional doses. PMID:8102213

Antibodies to ribosomal P proteins of Trypanosoma cruzi in Chagas disease possess functional autoreactivity with heart tissue and differ from anti-P autoantibodies in lupus.

PubMed

Kaplan, D; Ferrari, I; Bergami, P L; Mahler, E; Levitus, G; Chiale, P; Hoebeke, J; Van Regenmortel, M H; Levin, M J

1997-09-16

Anti-P antibodies present in sera from patients with chronic Chagas heart disease (cChHD) recognize peptide R13, EEEDDDMGFGLFD, which encompasses the C-terminal region of the Trypanosoma cruzi ribosomal P1 and P2 proteins. This peptide shares homology with the C-terminal region (peptide H13 EESDDDMGFGLFD) of the human ribosomal P proteins, which is in turn the target of anti-P autoantibodies in systemic lupus erythematosus (SLE), and with the acidic epitope, AESDE, of the second extracellular loop of the beta1-adrenergic receptor. Anti-P antibodies from chagasic patients showed a marked preference for recombinant parasite ribosomal P proteins and peptides, whereas anti-P autoantibodies from SLE reacted with human and parasite ribosomal P proteins and peptides to the same extent. A semi-quantitative estimation of the binding of cChHD anti-P antibodies to R13 and H13 using biosensor technology indicated that the average affinity constant was about 5 times higher for R13 than for H13. Competitive enzyme immunoassays demonstrated that cChHD anti-P antibodies bind to the acidic portions of peptide H13, as well as to peptide H26R, encompassing the second extracellular loop of the beta1 adrenoreceptor. Anti-P antibodies isolated from cChHD patients exert a positive chronotropic effect in vitro on cardiomyocytes from neonatal rats, which resembles closely that of anti-beta1 receptor antibodies isolated from the same patient. In contrast, SLE anti-P autoantibodies have no functional effect. Our results suggest that the adrenergic-stimulating activity of anti-P antibodies may be implicated in the induction of functional myocardial impairments observed in cChHD.

Antibodies to ribosomal P proteins of Trypanosoma cruzi in Chagas disease possess functional autoreactivity with heart tissue and differ from anti-P autoantibodies in lupus

PubMed Central

Kaplan, Dan; Ferrari, Ines; Bergami, Pablo Lopez; Mahler, Evelina; Levitus, Gabriela; Chiale, Pablo; Hoebeke, Johan; Van Regenmortel, Marc H. V.; Levin, Mariano J.

1997-01-01

Anti-P antibodies present in sera from patients with chronic Chagas heart disease (cChHD) recognize peptide R13, EEEDDDMGFGLFD, which encompasses the C-terminal region of the Trypanosoma cruzi ribosomal P1 and P2 proteins. This peptide shares homology with the C-terminal region (peptide H13 EESDDDMGFGLFD) of the human ribosomal P proteins, which is in turn the target of anti-P autoantibodies in systemic lupus erythematosus (SLE), and with the acidic epitope, AESDE, of the second extracellular loop of the β1-adrenergic receptor. Anti-P antibodies from chagasic patients showed a marked preference for recombinant parasite ribosomal P proteins and peptides, whereas anti-P autoantibodies from SLE reacted with human and parasite ribosomal P proteins and peptides to the same extent. A semi-quantitative estimation of the binding of cChHD anti-P antibodies to R13 and H13 using biosensor technology indicated that the average affinity constant was about 5 times higher for R13 than for H13. Competitive enzyme immunoassays demonstrated that cChHD anti-P antibodies bind to the acidic portions of peptide H13, as well as to peptide H26R, encompassing the second extracellular loop of the β1 adrenoreceptor. Anti-P antibodies isolated from cChHD patients exert a positive chronotropic effect in vitro on cardiomyocytes from neonatal rats, which resembles closely that of anti-β1 receptor antibodies isolated from the same patient. In contrast, SLE anti-P autoantibodies have no functional effect. Our results suggest that the adrenergic-stimulating activity of anti-P antibodies may be implicated in the induction of functional myocardial impairments observed in cChHD. PMID:9294205

The proliferative and chronotropic effects of Brillantaisia nitens Lindau (Acanthaceae) extracts on pluripotent stem cells and their cardiomyocytes derivatives.

PubMed

Nembo, Erastus Nembu; Dimo, Theophile; Bopda, Orelien Sylvain Mtopi; Hescheler, Jürgen; Nguemo, Filomain

2014-10-28

Brillantaisia nitens Lindau (Acanthaceae) leaves are commonly used in traditional medicine in Africa for the treatment of many disorders including heart diseases and malaria. In this study, we therefore evaluated the effect of the methylene chloride/methanol leaf extract of Brillantaisia nitens on the proliferation of mouse pluripotent stem cells and their cardiomyocyte derivatives. In this study, we combined two emerging technologies, pluripotent stem cell-derived cardiomyocytes and modern electrophysiology systems (impedance-based real-time) to assess the cytotoxicity of Brillantaisia nitens extract (BNE). Undifferentiated pluripotent cells and cardiomyocytes were exposed to different concentrations of BNE. Cell viability and contraction were monitored by impedance using the xCELLigence system for short- and long-term treatment whereas the excitability of single cardiomyocytes was captured by patch clamp technique after BNE acute exposure. Brillantaisia nitens extract inhibited the proliferation and increased cytotoxicity of embryonic stem cells in a concentration-dependent manner. With the increase in concentration of BNE, beating rate and the contractile amplitude of cardiomyocytes changed significantly. Spontaneous rhythmic activity of cardiomyocytes was completely suppressed after 48 and 24h exposures to relatively low (4.16 mg/ml) and high (8.32 mg/ml) concentrations of BNE, respectively. Moreover, acute application of 4.16 mg/ml of BNE led to a significant alteration of action potential (AP) parameters such as beating frequency, amplitude and AP duration at 90% of repolarization. Brillantaisia nitens extract inhibits the proliferative capacity of pluripotent stem cells and reduces electrical activity of cardiomyocytes, confirming its depressant action on the heart. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

A comparison of two different 2400 mOsm solutions for resuscitation of major burns.

PubMed

Milner, S M; Kinsky, M P; Guha, S C; Herndon, D N; Phillips, L G; Kramer, G C

1997-01-01

The reduction of burn edema is a common goal in the resuscitation of patients with thermal injury. Initial infusion of a 2400 mOsm hypertonic 7.5% NaCl 6% dextran (HSD) has been shown to reduce volume needs, but elevated serum sodium levels limit the dose that can be safely used. This study tested the hypothesis that a 2400 mOsm solution of NaCl, amino acids, glucose, and 6% dextran (Isosal-D) would reduce similar volume requirements while maintaining normal plasma sodium levels. Hemodynamics, plasma sodium, fluid balance, and tissue water content were measured after an initial baseline period and during resuscitation of a large scald injury in 21 anesthetized sheep. Resuscitation was begun 30 minutes after the scald with infusion of 10 ml/kg of either lactated Ringer's (LR), Isosal-D, or HSD and was continued with LR to restore and maintain baseline oxygen delivery throughout the 8-hour period. Oxygen delivery, cardiac output, and mean arterial pressure were rapidly reestablished by all three solutions, although a persistent tachycardia was noted with Isosal-D. Net fluid requirements of both HSD (35 +/- 13 ml/kg) and Isosal-D (72 +/- 13 ml/kg) were significantly lower than in the LR group (203 +/- 39 ml/kg). Mean serum sodium increased 11 mEq with HSD to a peak after 4 hours of 152 +/- 5 mEq, whereas with LR sodium fell 7 mEq to 132 +/- 4. Isosal-treated animals had minimal change in serum sodium. HSD significantly decreased tissue water content in colon, liver, pancreas, and nonburned skin compared with LR, whereas Isosal-D reduced edema only in the colon. It is concluded that in this protocol Isosal-D was not as effective as HSD at reducing volume needs and edema and had unexpected chronotropic effects.

Cardiovascular testing in Fabry disease: exercise capacity reduction, chronotropic incompetence and improved anaerobic threshold after enzyme replacement.

PubMed

Lobo, T; Morgan, J; Bjorksten, A; Nicholls, K; Grigg, L; Centra, E; Becker, G

2008-06-01

The aim of this study was to document exercise capacity and serial electrocardiogram and echocardiograph findings in a cohort of Australian patients with Fabry disease, in relation to their history of enzyme replacement therapy (ERT). Fabry disease has multifactorial effects on the cardiovascular system. Most previous studies have focused on electrocardiographic and echocardiographic parameters. Exercise capacity can be used as an integrated measure of cardiovascular function and allows the effects of treatment to be monitored. A total of 38 patients (30 men and 8 women) with Fabry disease were monitored by 12-lead electrocardiograms every 6-12 months, and by annual standardized-protocol echocardiograms. Bicycle stress tests with VO(2) max measurement and once-only 6 minutes' walk tests were also carried out in subsets of patients whose general health status allowed testing. Seventy per cent of patients met electrocardiogram criteria for left ventricular hypertrophy. Left ventricular hypertrophy on echocardiograph was present in 64% of patients (80% of men). Exercise capacity was reduced in patients with Fabry disease compared with that predicted from normative population data. Mild improvement in anaerobic threshold was seen in the first year of ERT (14.1 +/- 3.0 to 15.8 +/- 3.0, P = 0.02), but no consistent further increase was seen beyond the first year. Most patients had resting bradycardia, with impaired ability to increase heart rate during exercise. Serial testing on ERT showed an improvement in anaerobic threshold but no significant change in VO(2) max. Male patients with Fabry disease were unable to attain predicted maximal heart rate on exercise or to achieve normal exercise levels. ERT was associated with a small improvement in anaerobic threshold over the first year.

Central-peripheral neural network interactions evoked by vagus nerve stimulation: functional consequences on control of cardiac function.

PubMed

Ardell, Jeffrey L; Rajendran, Pradeep S; Nier, Heath A; KenKnight, Bruce H; Armour, J Andrew

2015-11-15

Using vagus nerve stimulation (VNS), we sought to determine the contribution of vagal afferents to efferent control of cardiac function. In anesthetized dogs, the right and left cervical vagosympathetic trunks were stimulated in the intact state, following ipsilateral or contralateral vagus nerve transection (VNTx), and then following bilateral VNTx. Stimulations were performed at currents from 0.25 to 4.0 mA, frequencies from 2 to 30 Hz, and a 500-μs pulse width. Right or left VNS evoked significantly greater current- and frequency-dependent suppression of chronotropic, inotropic, and lusitropic function subsequent to sequential VNTx. Bradycardia threshold was defined as the current first required for a 5% decrease in heart rate. The threshold for the right vs. left vagus-induced bradycardia in the intact state (2.91 ± 0.18 and 3.47 ± 0.20 mA, respectively) decreased significantly with right VNTx (1.69 ± 0.17 mA for right and 3.04 ± 0.27 mA for left) and decreased further following bilateral VNTx (1.29 ± 0.16 mA for right and 1.74 ± 0.19 mA for left). Similar effects were observed following left VNTx. The thresholds for afferent-mediated effects on cardiac parameters were 0.62 ± 0.04 and 0.65 ± 0.06 mA with right and left VNS, respectively, and were reflected primarily as augmentation. Afferent-mediated tachycardias were maintained following β-blockade but were eliminated by VNTx. The increased effectiveness and decrease in bradycardia threshold with sequential VNTx suggest that 1) vagal afferents inhibit centrally mediated parasympathetic efferent outflow and 2) the ipsilateral and contralateral vagi exert a substantial buffering capacity. The intact threshold reflects the interaction between multiple levels of the cardiac neural hierarchy. Copyright © 2015 the American Physiological Society.

Central-peripheral neural network interactions evoked by vagus nerve stimulation: functional consequences on control of cardiac function

PubMed Central

Rajendran, Pradeep S.; Nier, Heath A.; KenKnight, Bruce H.; Armour, J. Andrew

2015-01-01

Using vagus nerve stimulation (VNS), we sought to determine the contribution of vagal afferents to efferent control of cardiac function. In anesthetized dogs, the right and left cervical vagosympathetic trunks were stimulated in the intact state, following ipsilateral or contralateral vagus nerve transection (VNTx), and then following bilateral VNTx. Stimulations were performed at currents from 0.25 to 4.0 mA, frequencies from 2 to 30 Hz, and a 500-μs pulse width. Right or left VNS evoked significantly greater current- and frequency-dependent suppression of chronotropic, inotropic, and lusitropic function subsequent to sequential VNTx. Bradycardia threshold was defined as the current first required for a 5% decrease in heart rate. The threshold for the right vs. left vagus-induced bradycardia in the intact state (2.91 ± 0.18 and 3.47 ± 0.20 mA, respectively) decreased significantly with right VNTx (1.69 ± 0.17 mA for right and 3.04 ± 0.27 mA for left) and decreased further following bilateral VNTx (1.29 ± 0.16 mA for right and 1.74 ± 0.19 mA for left). Similar effects were observed following left VNTx. The thresholds for afferent-mediated effects on cardiac parameters were 0.62 ± 0.04 and 0.65 ± 0.06 mA with right and left VNS, respectively, and were reflected primarily as augmentation. Afferent-mediated tachycardias were maintained following β-blockade but were eliminated by VNTx. The increased effectiveness and decrease in bradycardia threshold with sequential VNTx suggest that 1) vagal afferents inhibit centrally mediated parasympathetic efferent outflow and 2) the ipsilateral and contralateral vagi exert a substantial buffering capacity. The intact threshold reflects the interaction between multiple levels of the cardiac neural hierarchy. PMID:26371171

Is there a place for intra-aortic balloon counterpulsation support in acute right ventricular failure by pressure-overload?

PubMed

Vanden Eynden, Frederic; Mets, Gilles; De Somer, Filip; Bouchez, Stefaan; Bove, Thierry

2015-10-15

Most therapeutic strategies for acute right ventricular failure (RVF) by pressure-overload are directed to improve cardiac output and coronary perfusion pressure by vasopressive agents. The eventual role of intra-aortic balloon counterpulsation (IABP) support remains questionable. This study investigates the contribution of IABP for acute RVF by pressure-overload, in comparison with phenylephrine (PE) and norepinephrine (NOR). Acute RVF is induced by fixed pulmonary artery constriction in 6 pigs, pursuing a 50% reduction of cardiac output. Assessment of the treatment interventions included biventricular PV-loop analysis, and continuous measurement of aortic and right coronary artery flow. Restoration of baseline cardiac output was only observed by administration of NOR (Baseline=3.82±1.52ml/min - RVF=2.03±0.59ml/min - IABP=2.45±0.62ml/min - PE=2.98±0.63ml/min - NOR=3.95±0.73ml/min, p<0.001). NOR had most effect on biventricular contractility (PRSW-slope-RV: IABP +24% - PE +59% - NOR +208%, p<0.001 and PRSW-slope-LV: IABP +36% - PE +53% - NOR +196%, p<0.001), heart rate acceleration (IABP +7% - PE +12% - NOR +51%, p<0.001), and RCA flow (IABP +31% - PE +58% - NOR +180%, p<0.001), concomitant to a higher increase of LV-to-RV pressure ratio (IABP: +7% versus -3%, PE: +36% versus +8%, NOR: +101% versus 42%). The hemodynamic contribution of IABP was limited, unless a modest improvement of LV compliance during PE and NOR infusion. In a model of acute pressure-overload RV failure, IABP appears to offer limited hemodynamic benefit. The administration of norepinephrine is most effective to correct systemic output and myocardial perfusion through adding an inotropic and chronotropic effect to systemic vasopression. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Moderate intensity physical activity prevents increased blood glucose concentrations, fat pad deposition and cardiac action potential prolongation following diet-induced obesity in a juvenile-adolescent rat model.

PubMed

van Waveren, Alannah; Duncan, Mitch J; Coulson, Fiona R; Fenning, Andrew

2014-01-01

Both obesity and a lack of physical activity have been associated with an elevated risk of cardiovascular disease (CVD). The incidence of obesity is increasing, especially in juvenile-adolescents. While there is limited research examining the chronic effects of obesity in adolescent humans and animal models of this condition, little is also known concerning how moderate physical activity might prevent or attenuate secondary cardiovascular complications induced by obesity during adolescence. We investigated the effects of diet-induced obesity (consisting of a high-fat, high-carbohydrate diet (HFHC)) on biometric indices, vascular and airway function, cardiovascular function, systemic oxidative stress and markers of inflammation in a juvenile-adolescent rodent model. Four groups were used: control (CON), physical activity (PA) treated, HFHC and HFHC + PA (n = 16 per group). HFHC feeding started at 4 weeks of age for a period of 12 weeks. Physical activity treatment was initiated (PA and HFHC + PA groups) when the animals were 8 weeks of age, for 8 weeks. Physical activity in juvenile-adolescent healthy rats showed no change in comparison to the CON group in all experimental parameters except for increases in lipid peroxidation, decreases in inflammatory cytokines, improvements in vascular reactivity and decreased atrial responses to positive chronotropic agents. The HFHC animals were mildly hyperglycemic, hypertensive, displayed renal hypertrophy and showed increased retroperitoneal fat pad deposition compared to the CON group. HFHC + PA rats were also hypertensive, however showed improvements in cardiac electrophysiology, body weight, fat pad deposition and inflammatory signaling, in comparison to the HFHC fed rats and CON animals. In conclusion, in a juvenile-adolescent animal model of diet-induced obesity engagement in physical activity is beneficial in reducing the inflammatory effects of obesity.

[Myocardial mechanical injury in acute ischemia: a pathophysiologic and histopathologic review].

PubMed

Rossi, L; Matturri, L

1986-03-01

The recognition of histopathologic substrates of myocardial contractile damage in human acute ischemia is still very poor, notwithstanding the impressive advances in the inherent clinical diagnostic technology and concepts. The first and foremost inotropic abnormality ensuing ischemia, easily taken for atonic in origin, actually consists of a pathologic contracture of the injured myocardium, depending upon abrupt fall of ATP, and defective extrusion calcium pump with persistence of actomyosin rigor-complexes. In sustained ischemia, further membrane damage exposes the myocell to massive calcium intrusion, with eventual precipitation of it and cell death (reperfusion stone-heart). In case of transient, "hit and run" ischemia, the "stunned" myocardium undergoes prolonged contractile abnormalities. In keeping with fundamentals in pathophysiology of contraction, ischemic myofibrils in human hyperacute infarct, showed spare I bands, accounting for contracture and followed by loss of the regular cross-striation register; then, groups of adjacent sarcomeres were seen to join into true "contraction" bands, with Z lines impinging upon A bands and obliterating the I bands. Coagulative denaturation of contractile proteins follows, presenting as irregular, amorphous degeneration stripes astride irreversibly damaged myocells. As such, these cells can be passively overstretched by the nearby functioning muscle. In turn, the fixed waviness of viable, acutely ischemic myocardium was thought to configure, histologically, the loss of ATP-dependent "plasticity" of myofilaments, in a state of contracture. The "relaxant effect" of inotropic-chronotropic-positive catecholamines, favoring diastole, has been also pointed out. The present microscopic findings are cogent to clinicopathologic problems of coronary ischemia-reperfusion, and sudden death from cardiogenic shock.

Idiopathic accelerated idioventricular rhythm or ventricular tachycardia originating from the right bundle branch: unusual type of ventricular arrhythmia.

PubMed

Chen, Minglong; Gu, Kai; Yang, Bing; Chen, Hongwu; Ju, Weizhu; Zhang, Fengxiang; Yang, Gang; Li, Mingfang; Lu, Xinzheng; Cao, Kejiang; Ouyang, Feifan

2014-12-01

Accelerated idioventricular rhythm (AIVR) or ventricular tachycardia (VT) originating from the right bundle branch (RBB) is rare and published clinical data on such arrhythmia are scarce. In this study, we will describe the clinical manifestations, diagnosis, and management of a cohort of patients with this novel arrhythmia. Eight patients (5 men; median age, 25 years) with RBB-AIVR/VT were consecutively enrolled in the study. Pharmacological testing, exercise treadmill testing, electrophysiological study, and catheter ablation were performed in the study patients, and ECG features were characterized. All RBB-AIVR/VTs were of typical left bundle-branch block morphology with atrioventricular dissociation. The arrhythmias, which demonstrated chronotropic variability, were often isorhythmic with sinus rhythm and were accelerated by physical exercise, stress, and intravenous isoprenaline infusion. The rate of RBB-AIVR/VT varied from 45 to 200 beats per minute. Two patients experienced syncope, and 3 had impaired left ventricular function. Metoprolol was proven to be the most effective drug to decelerate the arrhythmia rate and relieve symptoms. Electrophysiology study was performed in 5 patients and the earliest activation with a sharp RBB potential was localized in the mid or distal RBB area. Catheter ablation terminated the arrhythmia with subsequent RBB block morphology during sinus rhythm. During follow-up, patients' symptoms were controlled with normalization of left ventricular function either on metoprolol or by catheter ablation. RBB-AIVR/VT is an unusual type of ventricular arrhythmia. It can result in significant symptoms and depressed ventricular function and can be successfully treated with catheter ablation. © 2014 American Heart Association, Inc.

Heart rate behavior during an exercise stress test in obese patients.

PubMed

Gondoni, L A; Titon, A M; Nibbio, F; Augello, G; Caetani, G; Liuzzi, A

2009-03-01

Heart rate (HR) response to exercise has not been fully described in the obese. We wanted to study the differences between obese and non-obese patients in HR behavior during an exercise stress test and to determine whether these differences influence exercise capacity. We studied 554 patients (318 females) who underwent a treadmill exercise test. All subjects were in sinus rhythm. Patients with ischemic heart disease, with reduced ejection fraction and patients taking drugs that interfere with HR were excluded. The population included 231 patients with BMI<30 kg/m(2) (group 1), 212 patients who were unfit and obese (group 2) and 111 patients who were trained obese (group 3). Resting HR was similar in the various groups. Peak HR, HR recovery and chronotropic index were lower in obese subjects, regardless of their fitness level. Multivariate analysis showed that HR related variables were associated with age, BMI, height, hypertension and various pharmacologic treatments, while exercise capacity was strongly dependent on HR behavior, as well as on sex, age, BMI and diabetes. Obese subjects have a marked impairment of HR behavior during exercise and in the recovery period, and the blunted increase in HR is the most important factor that influences exercise capacity.

Optimal pacing modes after cardiac transplantation: is synchronisation of recipient and donor atria beneficial?

PubMed Central

Parry, Gareth; Malbut, Katie; Dark, John H; Bexton, Rodney S

1992-01-01

Objective—To investigate the response of the transplanted heart to different pacing modes and to synchronisation of the recipient and donor atria in terms of cardiac output at rest. Design—Doppler derived cardiac output measurements at three pacing rates (90/min, 110/min and 130/min) in five pacing modes: right ventricular pacing, donor atrial pacing, recipient-donor synchronous pacing, donor atrial-ventricular sequential pacing, and synchronous recipient-donor atrial-ventricular sequential pacing. Patients—11 healthy cardiac transplant recipients with three pairs of epicardial leads inserted at transplantation. Results—Donor atrial pacing (+11% overall) and donor atrial-ventricular sequential pacing (+8% overall) were significantly better than right ventricular pacing (p < 0·001) at all pacing rates. Synchronised pacing of recipient and donor atrial segments did not confer additional benefit in either atrial or atrial-ventricular sequential modes of pacing in terms of cardiac output at rest at these fixed rates. Conclusions—Atrial pacing or atrial-ventricular sequential pacing appear to be appropriate modes in cardiac transplant recipients. Synchronisation of recipient and donor atrial segments in this study produced no additional benefit. Chronotropic competence in these patients may, however, result in improved exercise capacity and deserves further investigation. PMID:1389737

Effect of Beta-Blocker Therapy, Maximal Heart Rate, and Exercise Capacity During Stress Testing on Long-Term Survival (from The Henry Ford Exercise Testing Project).

PubMed

Hung, Rupert K; Al-Mallah, Mouaz H; Whelton, Seamus P; Michos, Erin D; Blumenthal, Roger S; Ehrman, Jonathan K; Brawner, Clinton A; Keteyian, Steven J; Blaha, Michael J

2016-12-01

Whether lower heart rate thresholds (defined as the percentage of age-predicted maximal heart rate achieved, or ppMHR) should be used to determine chronotropic incompetence in patients on beta-blocker therapy (BBT) remains unclear. In this retrospective cohort study, we analyzed 64,549 adults without congestive heart failure or atrial fibrillation (54 ± 13 years old, 46% women, 29% black) who underwent clinician-referred exercise stress testing at a single health care system in Detroit, Michigan from 1991 to 2009, with median follow-up of 10.6 years for all-cause mortality (interquartile range 7.7 to 14.7 years). Using Cox regression models, we assessed the effect of BBT, ppMHR, and estimated exercise capacity on mortality, with adjustment for demographic data, medical history, pertinent medications, and propensity to be on BBT. There were 9,259 deaths during follow-up. BBT was associated with an 8% lower adjusted achieved ppMHR (91% in no BBT vs 83% in BBT). ppMHR was inversely associated with all-cause mortality but with significant attenuation by BBT (per 10% ppMHR HR: no BBT: 0.80 [0.78 to 0.82] vs BBT: 0.89 [0.87 to 0.92]). Patients on BBT who achieved 65% ppMHR had a similar adjusted mortality rate as those not on BBT who achieved 85% ppMHR (p >0.05). Estimated exercise capacity further attenuated the prognostic value of ppMHR (per-10%-ppMHR HR: no BBT: 0.88 [0.86 to 0.90] vs BBT: 0.95 [0.93 to 0.98]). In conclusion, the prognostic value of ppMHR was significantly attenuated by BBT. For patients on BBT, a lower threshold of 65% ppMHR may be considered for determining worsened prognosis. Estimated exercise capacity further diminished the prognostic value of ppMHR particularly in patients on BBT. Copyright © 2016 Elsevier Inc. All rights reserved.

Evaluation of partial beta-adrenoceptor agonist activity.

PubMed

Lipworth, B J; Grove, A

1997-01-01

A partial beta-adrenoceptor (beta-AR) agonist will exhibit opposite agonist and antagonist activity depending on the prevailing degree of adrenergic tone or the presence of a beta-AR agonist with higher intrinsic activity. In vivo partial beta-AR agonist activity will be evident at rest with low endogenous adrenergic tone, as for example with chronotropicity (beta 1/beta 2), inotropicity (beta 1) or peripheral vasodilatation and finger tremor (beta 2). beta-AR blocking drugs which have partial agonist activity may exhibit a better therapeutic profile when used for hypertension because of maintained cardiac output without increased systemic vascular resistance, along with an improved lipid profile. In the presence of raised endogenous adrenergic tone such as exercise or an exogenous full agonist, beta-AR subtype antagonist activity will become evident in terms of effects on exercise induced heart rate (beta 1) and potassium (beta 2) responses. Reduction of exercise heart rate will occur to a lesser degree in the case of a beta-adrenoceptor blocker with partial beta 1-AR agonist activity compared with a beta-adrenoceptor blocker devoid of partial agonist activity. This may result in reduced therapeutic efficacy in the treatment of angina on effort when using beta-AR blocking drugs with partial beta 1-AR agonist activity. Effects on exercise hyperkalaemia are determined by the balance between beta 2-AR partial agonist activity and endogenous adrenergic activity. For predominantly beta 2-AR agonist such as salmeterol and salbutamol, potentiation of exercise hyperkalaemia occurs. For predominantly beta 2-AR antagonists such as carteolol, either potentiation or attenuation of exercise hyperkalaemia occurs at low and high doses respectively. beta 2-AR partial agonist activity may also be expressed as antagonism in the presence of an exogenous full agonist, as for example attenuation of fenoterol induced responses by salmeterol. Studies are required to investigate whether this phenomenon is relevant in the setting of acute severe asthma.

Strain, strain rate, and the force frequency relationship in patients with and without heart failure.

PubMed

Mak, Susanna; Van Spall, Harriette G C; Wainstein, Rodrigo V; Sasson, Zion

2012-03-01

The aim of this study was to examine the effect of heart rate (HR) on indices of deformation in adults with and without heart failure (HF) who underwent simultaneous high-fidelity catheterization of the left ventricle to describe the force-frequency relationship. Right atrial pacing to control HR and high-fidelity recordings of left ventricular (LV) pressure were used to inscribe the force-frequency relationship. Simultaneous two-dimensional echocardiographic imaging was acquired for speckle-tracking analysis. Thirteen patients with normal LV function and 12 with systolic HF (LV ejection fraction, 31 ± 13%) were studied. Patients with HF had depressed isovolumic contractility and impaired longitudinal strain and strain rate. HR-dependent increases in LV+dP/dt(max), the force-frequency relationship, was demonstrated in both groups (normal LV function, baseline to 100 beats/min: 1,335 ± 296 to 1,564 ± 320 mm Hg/sec, P < .0001; HF, baseline to 100 beats/min: 970 ± 207 to 1,083 ± 233 mm Hg/sec, P < .01). Longitudinal strain decreased significantly (normal LV function, baseline to 100 beats/min: 18.0 ± 3.5% to 10.8 ± 6.0%, P < .001; HF: 9.4 ± 4.1% to 7.5 ± 3.4%, P < .01). The decrease in longitudinal strain was related to a decrease in LV end-diastolic dimensions. Strain rate did not change with right atrial pacing. Despite the inotropic effect of increasing HR, longitudinal strain decreases in parallel with stroke volume as load-dependent indices of ejection. Strain rate did not reflect the modest HR-related changes in contractility; on the other hand, the use of strain rate for quantitative stress imaging is also less likely to be confounded by chronotropic responses. Copyright © 2012 American Society of Echocardiography. Published by Mosby, Inc. All rights reserved.

A comparison of the chronotropic and dromotropic actions between adenosine triphosphate and edrophonium in patients undergoing coronary artery bypass graft surgery.

PubMed

Watanabe, Seiji; Kono, Yasuo; Oishi-Tobinaga, Yoko; Yamada, Shin-ichi; Hara, Masato; Kano, Tatsuhiko

2002-10-01

To compare the effects of the stimulation of adenosine receptors and acetylcholine receptors in the cardiac conduction system in patients with ischemic heart disease. Prospective. University hospital. Patients scheduled for coronary artery bypass graft surgery (n = 37). The patients were divided into 3 groups: control group (n = 9), adenosine triphosphate (ATP) group (n = 12), and edrophonium group (n = 16). ATP (10 mg) or edrophonium (0.25 mg/kg) followed by saline or the same amount of saline was injected through a central venous catheter. ATP induced atrioventricular block in 10 of 12 patients (83%). The ATP injection produced a more prominent prolongation in the PQ duration (P-R interval) (139%) than in the P-P interval (105%) at the last beat before the development of atrioventricular block. The prolongation in the P-P interval (11%, average 85 msec) and PQ duration during atrioventricular block disappeared immediately after the restoration of atrioventricular conduction. After edrophonium, the maximal prolongation in P-P (118%, p < 0.01) and PQ (120%, p < 0.01) intervals was the same. P-P interval remained prolonged (p < 0.01) after PQ interval returned to baseline. Neither ATP nor edrophonium affected the QRS duration. These findings suggest that ATP predominantly inhibited atrioventricular conduction rather than the firing rate of sinoatrial nodes, and edrophonium inhibited both proportionally even with prolonged inhibitory action on the sinoatrial nodes. An injection of ATP is needed only when a transient cardiac standstill is requested, such as in endovascular grafting surgery. Edrophonium may be used to slow heart rate during coronary artery bypass graft surgery. Copyright 2002, Elsevier Science (USA). All rights reserved.

[Adaptation to effort in patients with chronic cardiac insufficiency; study by post-exercise Doppler echocardiography, comparative results with a control population].

PubMed

Pouillart, F; Perchet, H; Duval-Moulin, A M; Heintz, J F; Hittinger, L; Brun, P; Castaigne, A; Dubois-Randé, J L

1995-04-01

Adaptation to exercise was studied by post-exercise Doppler echocardiography in patients with chronic cardiac failure and an apparently healthy control population matched for age. This post-exercise Doppler echocardiographic method initially introduced for the detection of myocardial ischaemia has already been validated in normal subjects for the analysis of haemodynamic changes caused by exercise providing the data is recorded in the first 5 minutes following recovery in the recumbent position. Eleven patients with chronic cardiac failure in NYHA classes II or III with a mean age of 54 +/- 11 years and 6 controls (mean age: 46 +/- 9 years) were investigated. The patients had been stabilised for at least 3 months with a vasodilator and diuretic therapy: the control subjects had no medication. After bicycle ergometry performed to 70% of maximum capacity, the subjects were positioned in the left lateral recumbent position. Doppler echocardiography was then performed in the immediate recovery phase. When compared to the control population, the patients with cardiac failure had a reduced chronotropic reserve, a smaller increase in the parameters of myocardial contractility (maximal aortic velocity, maximal aortic acceleration and left ventricular fractional shortening) without an increase in left ventricular end diastolic dimensions in subjects with severe dilatation under basal conditions (left ventricular end diastolic dimension 69 +/- 3 mm). This result suggests the absence of a Frank-Starling effect. The lack of adaptation of the peripheral vascular system was demonstrated by the lack of reduction of left ventricular end systolic stress, already greatly increased at rest (176 vs 77 +/- 10 g/cm2 for patients, compared with controls; p < 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Inhibition by enflurane and methoxyflurane of postdrive hyperpolarization in canine Purkinje fibers.

PubMed

Pratila, M; Vogel, S; Sperelakis, N

1984-05-01

When a pacemaker cell is driven with a train of stimuli at a rate faster than its own, the termination of the drive is followed by a transient hyperpolarization, due to the activity of an electrogenic Na+-K+ pump. In this study, the effect of the halogenated ethers, enflurane and methoxyflurane, on postdrive hyperpolarization (PDH) was determined in cardiac Purkinje fibers. The fibers were removed from freshly excised canine hearts and superfused with a Tyrode's solution (containing 2.7 or 3.5 mM K+). The preparation was paced at 0.2 Hz before and after drives, and at 2 Hz during drives. Under control conditions, drives of 2 min produced a PDH of 5.5 +/- 0.2 mV. Enflurane (1.5-5%) significantly reduced the PDH. At 4 to 5%, enflurane reduced the PDH to a mean value of 42% of the control. Methoxyflurane was more potent than enflurane in affecting the PDH. At 0.5 to 0.75%, methoxyflurane reduced the PDH to 5% of the control. At higher (1-1.5%) concentrations of methoxyflurane, the PDH was converted to a depolarization, which varied between 0.5 and 8.0 mV. The PDH was restored to control levels within 10 to 20 min after washout of either anesthetic agent. Methoxyflurane (0.5 or 1%) enhanced the automaticity of spontaneously firing cells (2.35 mM K+ Tyrode's solution used). This positive chronotropic action coincided with a depolarization of 2 to 8 mV. Enflurane, at concentrations of 3 to 5%, gave similar results. On the action potential, methoxyflurane, at 1%, reduced the amplitude and duration (measured at 50% repolarization) of the plateau, and also the maximal upstroke velocity (+Vmax) of the rising phase.(ABSTRACT TRUNCATED AT 250 WORDS)

Comparison of three methods to identify the anaerobic threshold during maximal exercise testing in patients with chronic heart failure.

PubMed

Beckers, Paul J; Possemiers, Nadine M; Van Craenenbroeck, Emeline M; Van Berendoncks, An M; Wuyts, Kurt; Vrints, Christiaan J; Conraads, Viviane M

2012-02-01

Exercise training efficiently improves peak oxygen uptake (V˙O2peak) in patients with chronic heart failure. To optimize training-derived benefit, higher exercise intensities are being explored. The correct identification of anaerobic threshold is important to allow safe and effective exercise prescription. During 48 cardiopulmonary exercise tests obtained in patients with chronic heart failure (59.6 ± 11 yrs; left ventricular ejection fraction, 27.9% ± 9%), ventilatory gas analysis findings and lactate measurements were collected. Three technicians independently determined the respiratory compensation point (RCP), the heart rate turning point (HRTP) and the second lactate turning point (LTP2). Thereafter, exercise intensity (target heart rate and workload) was calculated and compared between the three methods applied. Patients had significantly reduced maximal exercise capacity (68% ± 21% of predicted V˙O2peak) and chronotropic incompetence (74% ± 7% of predicted peak heart rate). Heart rate, workload, and V˙O2 at HRTP and at RCP were not different, but at LTP2, these parameters were significantly (P < 0.0001) higher. Mean target heart rate and target workload calculated using the LTP2 were 5% and 12% higher compared with those calculated using HRTP and RCP, respectively. The calculation of target heart rate based on LTP2 was 5% and 10% higher in 12 of 48 (25%) and 6 of 48 (12.5%) patients, respectively, compared with the other two methods. In patients with chronic heart failure, RCP and HRTP, determined during cardiopulmonary exercise tests, precede the occurrence of LTP2. Target heart rates and workloads used to prescribe tailored exercise training in patients with chronic heart failure based on LTP2 are significantly higher than those derived from HRTP and RCP.

Cardiorespiratory response to exercise after renal sympathetic denervation in patients with resistant hypertension.

PubMed

Ukena, Christian; Mahfoud, Felix; Kindermann, Ingrid; Barth, Christine; Lenski, Matthias; Kindermann, Michael; Brandt, Mathias C; Hoppe, Uta C; Krum, Henry; Esler, Murray; Sobotka, Paul A; Böhm, Michael

2011-09-06

This study sought to investigate the effects of interventional renal sympathetic denervation (RD) on cardiorespiratory response to exercise. RD reduces blood pressure at rest in patients with resistant hypertension. We enrolled 46 patients with therapy-resistant hypertension as extended investigation of the Symplicity HTN-2 (Renal Denervation With Uncontrolled Hypertension) trial. Thirty-seven patients underwent bilateral RD and 9 patients were assigned to the control group. Cardiopulmonary exercise tests were performed at baseline and 3-month follow-up. In the RD group, compared with baseline examination, blood pressure at rest and at maximum exercise after 3 months was significantly reduced by 31 ± 13/9 ± 13 mm Hg (p < 0.0001) and by 21 ± 20/5 ± 14 mm Hg (p < 0.0001), respectively. Achieved work rate increased by 5 ± 13 W (p = 0.029) whereas peak oxygen uptake remained unchanged. Blood pressure 2 min after exercise was significantly reduced by 29 ± 17/8 ± 15 mm Hg (p < 0.001 for systolic blood pressure; p = 0.002 for diastolic blood pressure). Heart rate at rest decreased after RD (4 ± 11 beats/min; p = 0.028), whereas maximum heart rate and heart rate increase during exercise were not different. Heart rate recovery improved significantly by 4 ± 7 beats/min after renal denervation (p = 0.009). In the control group, there were no significant changes in blood pressure, heart rate, maximum work rate, or ventilatory parameters after 3 months. RD reduces blood pressure during exercise without compromising chronotropic competence in patients with resistant hypertension. Heart rate at rest decreased and heart rate recovery improved after the procedure. (Renal Denervation With Uncontrolled Hypertension; [Symplicity HTN-2]; NCT00888433). Copyright © 2011 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

Cardiopulmonary Exercise Testing in Adult Congenital Heart Disease.

PubMed

Mantegazza, Valentina; Apostolo, Anna; Hager, Alfred

2017-07-01

Recently, the number of patients with congenital heart diseases reaching adulthood has been progressively increasing in developed countries, and new issues are emerging: the evaluation of their capacity to cope with physical activity and whether this knowledge can be used to optimize medical management. A symptom-limited cardiopulmonary exercise test has proven to be an essential tool, because it can objectively evaluate the functional cardiovascular capacity of these patients, identify the pathological mechanisms of the defect (circulatory failure, shunts, and/or pulmonary hypertension), and help prescribe an individualized rehabilitation program when needed. The common findings on cardiopulmonary exercise testing in patients with congenital heart diseases are a reduced peak [Formula: see text]o 2 , an early anaerobic threshold, a blunted heart rate response, a reduced increase of Vt, and an increased [Formula: see text]e/[Formula: see text]co 2 . All these measures suggest common pathophysiological abnormalities: (1) a compromised exercise capacity from anomalies affecting the heart, vessels, lungs, or muscles; (2) chronotropic incompetence secondary to cardiac autonomic dysfunction or β-blockers and antiarrhythmic therapy; and (3) ventilatory inefficiency caused by left-heart failure with pulmonary congestion, pulmonary hypertension, pulmonary obstructive vascular disease, or cachexia. Most of these variables also have prognostic significance. For these patients, cardiopulmonary exercise testing allows evaluation and decisions affecting lifestyle and therapeutic interventions.

Clinically oriented device programming in bradycardia patients: part 2 (atrioventricular blocks and neurally mediated syncope). Proposals from AIAC (Italian Association of Arrhythmology and Cardiac Pacing).

PubMed

Palmisano, Pietro; Ziacchi, Matteo; Biffi, Mauro; Ricci, Renato P; Landolina, Maurizio; Zoni-Berisso, Massimo; Occhetta, Eraldo; Maglia, Giampiero; Botto, Gianluca; Padeletti, Luigi; Boriani, Giuseppe

2018-04-01

: The purpose of this two-part consensus document is to provide specific suggestions (based on an extensive literature review) on appropriate pacemaker setting in relation to patients' clinical features. In part 2, criteria for pacemaker choice and programming in atrioventricular blocks and neurally mediate syncope are proposed. The atrioventricular blocks can be paroxysmal or persistent, isolated or associated with sinus node disease. Neurally mediated syncope can be related to carotid sinus syndrome or cardioinhibitory vasovagal syncope. In sinus rhythm, with persistent atrioventricular block, we considered appropriate the activation of mode-switch algorithms, and algorithms for auto-adaptive management of the ventricular pacing output. If the atrioventricular block is paroxysmal, in addition to algorithms mentioned above, algorithms to maximize intrinsic atrioventricular conduction should be activated. When sinus node disease is associated with atrioventricular block, the activation of rate-responsive function in patients with chronotropic incompetence is appropriate. In permanent atrial fibrillation with atrioventricular block, algorithms for auto-adaptive management of the ventricular pacing output should be activated. If the atrioventricular block is persistent, the activation of rate-responsive function is appropriate. In carotid sinus syndrome, adequate rate hysteresis should be programmed. In vasovagal syncope, specialized sensing and pacing algorithms designed for reflex syncope prevention should be activated.

Angiotensin I- and II- and norepinephrine-mediated pressor responses in an ancient holostean fish, the bowfin (Amia calva).

PubMed

Butler, D G; Oudit, G Y; Cadinouche, M Z

1995-06-01

Dorsal aortic blood pressure (PSYS, systolic; PDIAS, diastolic; and PDA, mean) and heart rate (HR) were measured in resting freshwater bowfins (n = 6), Amia calva L., before and after i.v. injections of 50, 100, 200, 500, and 1000 ng.kg-1 of synthetic [Asn1, Val5]-angiotensin II (ANG II). Baseline PSYS, PDIAS, and PDA were 27.7 +/- 2.8, 22.4 +/- 1.8, and 24.5 +/- 2 mm Hg, respectively. Bowfins were only moderately responsive to ANG II in a stepwise manner and the increase in blood pressure became significant only at the two highest doses; lower doses tended only to increase arterial pressure. Pressor responses due to 200 and 500 ng.kg-1 decayed over a greater time period compared with other doses. alpha-Adrenergic blockade abolished 70% of the ANG II-mediated pressor responses. Eel, salmon, and goosefish angiotensin I (ANG I; 500 ng.kg-1) elicited similar vasopressor responses (magnitude and time course) which were eliminated by prior angiotensin converting enzyme inhibition (captopril; 2-10 mg.kg-1). Bullfrog ANG I evoked a pressor effect, only at a higher dose (5000 ng.kg-1). Consecutive norepinephrine (NE) injections (100, 200, 500, and 1000 ng.kg-1) increased PSYS, PDIAS, and PDA in a dose-dependent manner which was dependent on alpha-adrenoceptors since phentolamine (1-3 mg.kg-1) abolished 80% of the pressor action of NE. PSYS was elevated by 100 ng.kg-1 of NE but PDIAS and PDA were significantly increased only at 200 ng.kg-1 ANG II and NE had no measurable chronotropic effect and resting HR (27.2 +/- 0.8 beats.min-1) was unchanged. Captopril and phentolamine treatments produced rapid hypotension and bradycardia (25-30%) which lasted from 15 to 30 and 20 to 40 min, respectively. The rising and decreasing phases of the NE-mediated pressor responses had shorter durations than ANG II effects. Tachyphylaxis occurred with the high doses of ANG II and NE. The data show that in the ancient bowfin, which evidently lacks renal juxtaglomerular cells, the cardiovascular system can be regulated by the renin-angiotensin system and NE.

The new generation dihydropyridine type calcium blockers, bearing 4-phenyl oxypropanolamine, display alpha-/beta-adrenoceptor antagonist and long-acting antihypertensive activities.

PubMed

Liang, Jhy-Chong; Yeh, Jwu-Lai; Wang, Chia-Sui; Liou, Shwu-Fen; Tsai, Chieh-Ho; Chen, Ing-Jun

2002-03-01

A new series of dihydropyridine derivatives, bearing oxypropanolamine moiety on phenyl ring at the 4-position of the dihydropyridine base, were prepared. Oxypropanolamine was synthesized by replacing the phenolic OH of vanillin or other compounds, having a phenyl aldehyde group, with epichlorohydrin, followed by cleavaging the obtained epoxide compounds with tert-butylamine, n-butylamine or 2-methoxy-1-oxyethylamino benzene (guaiacoxyethylamine), respectively. Obtained various oxypropanolamine compounds, still remaining a phenyl aldehyde moiety, were then performed by Hantzsch condensation reaction with methylacetoacetate or ethylacetoacetate, respectively, to give our new series of dihydropyridine linked with the 4-phenyl ring. These compounds were evaluated for inotropic, chronotropic, and aorta contractility that associated with calcium channel and adrenoceptor antagonist activities. Dihydropyridine derivatives that with oxypropanolamine side chain on their 4-phenyl ring associated alpha-/beta-adrenoceptor blocking activities created a new family of calcium entry and the third generation beta-adrenoceptor blockers. Optimizing this research to obtain more potent alpha-/beta-adrenoceptor blocking and long-acting antihypertensive oxypropanolamine on the 4-phenyl ring of dihydropyridine series compounds was thus accomplished and classified as third generation dihydropyridine type calcium channel blockers, in comparison with previous short-acting type nifedipine and long-acting type amlodipine. We concluded that compounds 1a, 1b and 1g showed not only markedly high calcium-antagonistic activity but also the highest antihypertensive effect; compounds 1b, 1c, 1f, 1g, 1i and 1j induced sustained antihypertensive effects are major and attributed to their calcium entry and alpha-adrenoceptor blocking activities in the blood vessel due to their introduction of 2-methoxy, 1-oxyethylamino benzene moiety in the side chain on the 4-phenyl ring of dihydropyridine. Bradycardiac effects of all the compounds 1a-1j resulted from calcium entry and beta-adrenoceptor blocking, which attenuate the sympathetic activation-associated reflex tachycardia in the heart. We selected compound 1b as candidate compound for further pharmacological and pre-clinical evaluation studies.

Heterogeneity of prejunctional NPY receptor-mediated inhibition of cardiac neurotransmission

PubMed Central

Serone, Adrian P; Wright, Christine E; Angus, James A

1999-01-01

Neuropeptide Y (NPY) has been proposed as the candidate inhibitory peptide mediating interactions between sympathetic and vagal neurotransmission in several species, including man. Here, we have defined the NPY receptors involved in modulation of cardiac autonomic neurotransmission using receptor-selective agonists and antagonists in the rabbit and guinea-pig isolated right atria.In isolated atrial preparations, sympathetically-mediated tachycardia (ST; with atropine 1 μM) or vagally-mediated bradycardia (VB; with propranolol 0.1–1 μM) in response to electrical field stimulation (EFS, 1–4 pulses) were tested 0–30 min after incubation with single concentrations of vehicle, NPY (0.01–10 μM), the Y2 receptor agonist N-Acetyl-[Leu28,31]NPY(24–36) (termed N-A[L]NPY(24–36)) or the Y1 receptor agonist [Leu31,Pro34]NPY (LP). The effect of NPY on the concentration-chronotropic response curves to isoprenaline and bethanechol were also assessed.Guinea-pig atria: NPY and N-A[L]NPY(24–36) caused concentration-dependent inhibition of VB and ST to EFS. Both peptides caused maximal inhibition of VB and ST within 10 min incubation and this remained constant. LP caused a concentration-dependent, transient inhibition of ST which was antagonized by the Y1-receptor antagonist GR231118 (0.3 μM), with apparent competitive kinetics. Rabbit atria: NPY (1 or 10 μM) had no effect on VB at any time point, but both NPY and LP caused a transient (∼10 min) inhibition of sympathetic tachycardia. This inhibition could be prevented by 0.3 μM GR231118. N-A[L]NPY(24–36) had no effect on ST. NPY had no effect on the response to β-adrenoceptor stimulation by isoprenaline nor muscarinic-receptor stimulation by bethanechol in either species.Thus, in the guinea-pig, NPY causes a stable inhibition of both VB and ST to EFS via Y2 receptors and transient inhibition of ST via Y1 receptors. In contrast in the rabbit, NPY has no effect on the cardiac vagus and prejunctional inhibition of ST is transient and mediated by a Y1-like receptor (rather than Y2). Therefore it would be surprising if NPY plays a functional role in modulation of cardiac neurotransmission in the rabbit. PMID:10369461

Cirrhotic cardiomyopathy: Implications for the perioperative management of liver transplant patients

PubMed Central

Rahman, Suehana; Mallett, Susan V

2015-01-01

Cirrhotic cardiomyopathy is a disease that has only recently been recognised as a definitive clinical entity. In the setting of liver cirrhosis, it is characterized by a blunted inotropic and chronotropic response to stress, impaired diastolic relaxation of the myocardium and prolongation of the QT interval in the absence of other known cardiac disease. A key pathological feature is the persistent over-activation of the sympathetic nervous system in cirrhosis, which leads to down-regulation and dysfunction of the β-adrenergic receptor. Diagnosis can be made using a combination of echocardiography (resting and stress), tissue Doppler imaging, cardiac magnetic resonance imaging, 12-lead electrocardiogram and measurement of biomarkers. There are significant implications of cirrhotic cardiomyopathy in a number of clinical situations in which there is an increased physiological demand, which can lead to acute cardiac decompensation and heart failure. Prior to transplantation there is an increased risk of hepatorenal syndrome, cardiac failure following transjugular intrahepatic portosystemic shunt insertion and increased risk of arrhythmias during acute gastrointestinal bleeding. Liver transplantation presents the greatest physiological challenge with a further risk of acute cardiac decompensation. Peri-operative management should involve appropriate choice of graft and minimization of large fluctuations in preload and afterload. The avoidance of cardiac failure during this period has important prognostic implications, as there is evidence to suggest a long-term resolution of the abnormalities in cirrhotic cardiomyopathy. PMID:25848474

Interventional cardiology for the criticalist.

PubMed

Scansen, Brian A

2011-04-01

To review indications, procedures, and prognosis for common cardiovascular emergencies requiring intervention in small animals. Pericardial effusion, symptomatic bradycardia, and heartworm-induced caval syndrome are examples of clinical scenarios commonly requiring intervention. Pericardial effusion in small animals occurs most frequently from cardiac neoplasia, idiopathic pericarditis, or congestive heart failure. Indications for temporary pacing include transient bradyarrhythmias, ingestions resulting in chronotropic incompetence, and emergency stabilization of critical bradyarrhythmias. Caval syndrome results from a large dirofilarial worm burden, pulmonary hypertension, and mechanical obstruction of right-sided cardiac output with resultant hemolysis and organ dysfunction. The diagnosis of pericardial effusion is suspected from signalment and physical findings and confirmed with cardiac ultrasound. Symptomatic bradycardias often present for syncope and definitive diagnosis derives from an ECG. Caval syndrome is diagnosed upon clinical, hematologic, and ultrasonographic evidence of severe heartworm infestation, cardiovascular compromise, and/or mechanical hemolysis. Pericardial effusion is alleviated by pericardiocentesis in the emergency setting, though may require further intervention for long-term palliation. Temporary transvenous pacing can be performed emergently to stabilize the symptomatic patient with a bradyarrhythmia. Dirofilariasis leading to caval syndrome requires urgent heartworm extraction. The prognosis for pericardial effusion is dependent upon the underlying etiology; the prognosis for cardiac pacing is favorable, and the prognosis for caval syndrome is grave if untreated and guarded to fair if heartworm extraction is performed. © Veterinary Emergency and Critical Care Society 2011.

The Negative Testing and Negative Generation Effects Are Eliminated by Delay

ERIC Educational Resources Information Center

Mulligan, Neil W.; Peterson, Daniel J.

2015-01-01

Although retrieval often enhances subsequent memory (the testing effect), a negative testing effect has recently been documented in which prior retrieval harms later recall compared with restudying. The negative testing effect was predicated on the negative generation effect and the item-specific-relational framework. The present experiments…

Sensitivity of negative subsequent memory and task-negative effects to age and associative memory performance.

PubMed

de Chastelaine, Marianne; Mattson, Julia T; Wang, Tracy H; Donley, Brian E; Rugg, Michael D

2015-07-01

The present fMRI experiment employed associative recognition to investigate the relationships between age and encoding-related negative subsequent memory effects and task-negative effects. Young, middle-aged and older adults (total n=136) were scanned while they made relational judgments on visually presented word pairs. In a later memory test, the participants made associative recognition judgments on studied, rearranged (items studied on different trials) and new pairs. Several regions, mostly localized to the default mode network, demonstrated negative subsequent memory effects in an across age-group analysis. All but one of these regions also demonstrated task-negative effects, although there was no correlation between the size of the respective effects. Whereas negative subsequent memory effects demonstrated a graded attenuation with age, task-negative effects declined markedly between the young and the middle-aged group, but showed no further reduction in the older group. Negative subsequent memory effects did not correlate with memory performance within any age group. By contrast, in the older group only, task-negative effects predicted later memory performance. The findings demonstrate that negative subsequent memory and task-negative effects depend on dissociable neural mechanisms and likely reflect distinct cognitive processes. The relationship between task-negative effects and memory performance in the older group might reflect the sensitivity of these effects to variations in amount of age-related neuropathology. This article is part of a Special Issue entitled SI: Memory. Copyright © 2014 Elsevier B.V. All rights reserved.

Intranasal oxytocin reduces provoked symptoms in female patients with posttraumatic stress disorder despite exerting sympathomimetic and positive chronotropic effects in a randomized controlled trial.

PubMed

Sack, M; Spieler, D; Wizelman, L; Epple, G; Stich, J; Zaba, M; Schmidt, U

2017-02-17

Posttraumatic stress disorder (PTSD) is a severe psychiatric disease accompanied by neuroendocrine changes such as adrenergic overdrive and hence an elevated cardiovascular morbidity. Current pharmacotherapeutic options for PTSD are less than suboptimal, necessitating the development of PTSD-specific drugs. Although the neuropeptide oxytocin has been repeatedly suggested to be effective in PTSD treatment, there are, to our knowledge, only three studies that have assessed its efficacy on the intensity of PTSD symptoms in PTSD patients - among them one symptom provocation study in male veterans. To evaluate for the first time how oxytocin influences the intensity of provoked PTSD symptoms and, furthermore, cardiac control in female PTSD patients, we assessed their psychic and cardiac response to trauma-script exposure with and without oxytocin pretreatment in a double-blind randomized placebo-controlled study. We used a within-subject design to study 35 female PTSD patients who received oxytocin and placebo in a 2-week interval. Furthermore, we performed a small pilot study to get an idea of the relation of the stress-modulated endogenous oxytocin levels and heart rate - we correlated oxytocin serum levels with the heart rate of 10 healthy individuals before and after exposure to the Trier Social Stress Test (TSST). Intranasal oxytocin treatment was followed by a reduction of provoked total PTSD symptoms, in particular of avoidance, and by an elevation in baseline and maximum heart rate together with a drop in the pre-ejection period, a marker for sympathetic cardiac control. Furthermore, we found a positive correlation between endogenous oxytocin levels and heart rate both before and after TSST challenge in healthy control subjects. This study provides the first evidence that oxytocin treatment reduces the intensity of provoked PTSD symptoms in female PTSD patients. The small size of both samples and the heterogeneity of the patient sample restrict the generalizability of our findings. Future studies have to explore the gender dependency and the tolerability of the oxytocin-mediated increase in heart rate. This randomized controlled trial was retrospectively registered at the German Trials Register (DRKS00009399) on the 02 October 2015.

Good cope, bad cope: adaptive and maladaptive coping strategies following a critical negative work event.

PubMed

Brown, Steven P; Westbrook, Robert A; Challagalla, Goutam

2005-07-01

The authors examined the moderating effects of coping tactics on the relationship between negative emotion and work performance. Findings indicate an adverse effect of emotion on performance; however, this effect is moderated by coping tactics. Venting (expressing one's negative feelings to others) amplified the adverse effects of negative emotion. Self-control had mixed effects: On one hand, it buffered the adverse effects of negative emotion, yet on the other hand, it had a negative direct effect on outcomes. Task focus had a positive direct effect on performance but no buffering (moderating) effect. Implications of these findings for understanding the effects of negative emotion and coping in the workplace are discussed. Copyright 2005 APA, all rights reserved.

Influence of N-hexane inhalation on the enantioselective pharmacokinetics and metabolism of verapamil in rats.

PubMed

Mateus, Fabiano H; Lepera, José S; Marques, Maria Paula; Boralli, Vanessa B; Lanchote, Vera L

2010-01-01

Verapamil (VER) is commercialized as a racemic mixture of the (+)-(R)-VER and (-)-(S)-VER enantiomers. VER is biotransformed into norverapamil (NOR) and other metabolites through CYP-dependent pathways. N-hexane is a solvent that can alter the metabolism of CYP-dependent drugs. The present study investigated the influence of n-hexane (nose-only inhalation exposure chamber at concentrations of 88, 176, and 352 mg/m3) on the kinetic disposition of the (+)-(R)-VER, (-)-(S)-VER, (R)-NOR and (S)-NOR in rats treated with a single dose of racemic VER (10 mg/kg). VER and NOR enantiomers in rat plasma was analyzed by LC-MS/MS (m/z = 441.3 > 165.5 for the NOR and m/z 455.3 > 165.5 for the VER enantiomers) using a Chiralpak AD column. Pharmacokinetic analysis was performed using a monocompartmental model. The pharmacokinetics of VER was enantioselective in control rats, with higher plasma proportions of the (-)-(S)-VER eutomer (AUC(0-infinity) = 250.8 vs. 120.4 ng/ml/h; P < or = 0.05, Wilcoxon test). The (S)-NOR metabolite was also found to accumulate in plasma of control animals, with an S/R AUC(0-infinity) ratio of 1.5. The pharmacokinetic parameters AUC(0-infinity), Cl/F, Vd/F, and t(1/2) obtained for VER and NOR enantiomers were not altered by nose-only exposure to n-hexane at concentrations of 88, 176, or 352 mg/m3 (P > 0.05, Kruskal-Wallis test). However, the verapamil kinetic disposition was not enantioselective for the animals exposed to n-hexane at concentrations equal to or higher than the TLV-TWA. This finding is relevant considering that the (-)-(S)-VER eutomer is 10-20 times more potent than R-(+)-VER in terms of its chronotropic effect on atrioventricular conduction in rats and humans. Copyright 2009 Wiley-Liss, Inc.

Contractile properties of early human embryonic stem cell-derived cardiomyocytes: beta-adrenergic stimulation induces positive chronotropy and lusitropy but not inotropy.

PubMed

Pillekamp, Frank; Haustein, Moritz; Khalil, Markus; Emmelheinz, Markus; Nazzal, Rewa; Adelmann, Roland; Nguemo, Filomain; Rubenchyk, Olga; Pfannkuche, Kurt; Matzkies, Matthias; Reppel, Michael; Bloch, Wilhelm; Brockmeier, Konrad; Hescheler, Juergen

2012-08-10

Human embryonic stem cell-derived cardiomyocytes (hESC-CMs) provide the unique opportunity to study the very early development of the human heart. The aim of this study was to investigate the effect of calcium and beta-adrenergic stimulation on the contractile properties of early hESC-CMs. Beating clusters containing hESC-CMs were co-cultured in vitro with noncontractile slices of neonatal murine ventricles. After 5-7 days, when beating clusters had integrated morphologically into the damaged tissue, isometric force measurements were performed during spontaneous beating as well as during electrical field stimulation. Spontaneous beating stopped when extracellular calcium ([Ca²⁺](ec)) was removed or after administration of the Ca²⁺ channel blocker nifedipine. During field stimulation at a constant rate, the developed force increased with incremental concentrations of [Ca²⁺](ec). During spontaneous beating, rising [Ca²⁺](ec) increased beating rate and developed force up to a [Ca²⁺](ec) of 2.5 mM. When [Ca²⁺](ec) was increased further, spontaneous beating rate decreased, whereas the developed force continued to increase. The beta-adrenergic agonist isoproterenol induced a dose-dependent increase of the frequency of spontaneous beating; however, it did not significantly change the developed force during spontaneous contractions or during electrical stimulation at a constant rate. Force developed by early hESC-CMs depends on [Ca²⁺](ec) and on the L-type Ca²⁺ channel. The lack of an inotropic reaction despite a pronounced chronotropic response after beta-adrenergic stimulation most likely indicates immaturity of the sarcoplasmic reticulum. For cell-replacement strategies, further maturation of cardiac cells has to be achieved either in vitro before or in vivo after transplantation.

Lower-limb hot-water immersion acutely induces beneficial hemodynamic and cardiovascular responses in peripheral arterial disease and healthy, elderly controls.

PubMed

Thomas, Kate N; van Rij, André M; Lucas, Samuel J E; Cotter, James D

2017-03-01

Passive heat induces beneficial perfusion profiles, provides substantive cardiovascular strain, and reduces blood pressure, thereby holding potential for healthy and cardiovascular disease populations. The aim of this study was to assess acute responses to passive heat via lower-limb, hot-water immersion in patients with peripheral arterial disease (PAD) and healthy, elderly controls. Eleven patients with PAD (age 71 ± 6 yr, 7 male, 4 female) and 10 controls (age 72 ± 7 yr, 8 male, 2 female) underwent hot-water immersion (30-min waist-level immersion in 42.1 ± 0.6°C water). Before, during, and following immersion, brachial and popliteal artery diameter, blood flow, and shear stress were assessed using duplex ultrasound. Lower-limb perfusion was measured also using venous occlusion plethysmography and near-infrared spectroscopy. During immersion, shear rate increased ( P < 0.0001) comparably between groups in the popliteal artery (controls: +183 ± 26%; PAD: +258 ± 54%) and brachial artery (controls: +117 ± 24%; PAD: +107 ± 32%). Lower-limb blood flow increased significantly in both groups, as measured from duplex ultrasound (>200%), plethysmography (>100%), and spectroscopy, while central and peripheral pulse-wave velocity decreased in both groups. Mean arterial blood pressure was reduced by 22 ± 9 mmHg (main effect P < 0.0001, interaction P = 0.60) during immersion, and remained 7 ± 7 mmHg lower 3 h afterward. In PAD, popliteal shear profiles and claudication both compared favorably with those measured immediately following symptom-limited walking. A 30-min hot-water immersion is a practical means of delivering heat therapy to PAD patients and healthy, elderly individuals to induce appreciable systemic (chronotropic and blood pressure lowering) and hemodynamic (upper and lower-limb perfusion and shear rate increases) responses. Copyright © 2017 the American Physiological Society.

Cardiac effects produced by long-term stimulation of thoracic autonomic ganglia or nerves: implications for interneuronal interactions within the thoracic autonomic nervous system.

PubMed

Butler, C; Watson-Wright, W M; Wilkinson, M; Johnstone, D E; Armour, J A

1988-03-01

Electrical stimulation of an acutely decentralized stellate or middle cervical ganglion or cardiopulmonary nerve augments cardiac chronotropism or inotropism; as the stimulation continues there is a gradual reduction of this augmentation following the peak response, i.e., an inhibition of augmentation. The amount of this inhibition was found to be dependent upon the region of the heart investigated and the neural structure stimulated. The cardiac parameters which were augmented the most displayed the greatest inhibition. Maximum augmentation or inhibition occurred, in most instances, when 5-20 Hz stimuli were used. Inhibition of augmentation was overcome when the stimulation frequency was subsequently increased or following the administration of nicotine or tyramine, indicating that the inhibition was not primarily due to the lack of availability of noradrenaline in the nerve terminals of the efferent postganglionic sympathetic neurons. Furthermore, as infusions of isoproterenol or noradrenaline during the period of inhibition could still augment cardiac responses, whereas during the early peak responses they did not, the inhibition of augmentation does not appear to be due primarily to down regulation of cardiac myocyte beta-adrenergic receptors. The inhibition was modified by hexamethonium but not by phentolamine or atropine. Inhibition occurred when all ipsilateral cardiopulmonary nerves connected with acutely decentralized middle cervical and stellate ganglia were stimulated, whereas significant inhibition did not occur when these nerves were stimulated after they had been disconnected from the ipsilateral decentralized ganglia. Taken together these data indicate that the inhibition of cardiac augmentation which occurs during relatively long-term stimulation of intrathoracic sympathetic neural elements is due in large part to nicotinic cholinergic synaptic mechanisms that lie primarily in the major thoracic autonomic ganglia. They also indicate that long-term stimulation in intrathoracic sympathetic neural elements with frequencies as low as 2 Hz may augment the heart as much as higher stimulation frequencies, depending upon the structure stimulated and the cardiovascular parameter monitored.

[Heart rate as a therapeutic target after acute coronary syndrome and in chronic coronary heart disease].

PubMed

Ambrosetti, Marco; Scardina, Giuseppe; Favretto, Giuseppe; Temporelli, Pier Luigi; Faggiano, Pompilio Massimo; Greco, Cesare; Pedretti, Roberto Franco

2017-03-01

For patients with stable coronary artery disease (SCAD), either after hospitalization for acute cardiac events or in the chronic phase, comprehensive treatment programs should be devoted to: (i) reducing mortality and major adverse cardiovascular events, (ii) reducing the ischemic burden and related symptoms, and (iii) increasing exercise capacity and quality of life.Heart rate (HR) has demonstrated to have prognostic value and patients beyond the limit of 70 bpm display increased risk of all the above adverse outcomes, even after adjustment for parameters such as the extension of myocardial infarction and the presence of heart failure. It is well known that a sustained HR elevation may contribute to the pathogenesis of SCAD, being the likelihood of developing ischemia, plaque instability, trigger for arrhythmias, increased vascular oxidative stress, and endothelial dysfunction the mechanisms resulting in this effect. Moreover, high HR could promote chronotropic incompetence, leading to functional disability and reduced quality of life.Despite the strong relationship between HR and prognosis, there is heterogeneity among current guidelines in considering HR as a formal therapeutic target for secondary prevention in SCAD, as far as the cut-off limit. This expert opinion document considered major trials and observational registries in the modern treatment era with beta-blockers and ivabradine, suggesting that an adequate HR control could represent a target for (i), (ii), and (iii) therapeutic goals in SCAD patients with systolic dysfunction (with major evidence for reduced left ventricular ejection fraction <40%), and a target for (ii) and (iii) goals in SCAD patients with preserved left ventricular ejection fraction. The defined cut-off limit is 70 bpm. To date, there is room for improvement of HR control, since in contemporary SCAD patients HR values <70 bpm are present in less than half of cases, even in the vulnerable phase after an acute coronary syndrome.

Rate and predictors of negative effects of psychotherapy in psychiatric and psychosomatic inpatients.

PubMed

Rheker, Julia; Beisel, Sylvia; Kräling, Svenja; Rief, Winfried

2017-08-01

Studies examining the rates of negative effects of psychotherapy are rare and the reported rates differ widely. To be able to calculate adequate benefit-cost ratios in conjunction with different samples and settings, we need a deeper understanding of these effects. We therefore investigated whether different treatment settings would reveal varying rates and kinds of negative effects by recruiting patients from a psychiatric (n=93) and a psychosomatic rehabilitation (n=63) hospital. Negative effects of psychotherapy were assessed with the Inventory for the Assessment of Negative Effects of Psychotherapy post-treatment. To investigate whether patients' pre-treatment expectations have an influence on reported negative effects, patients filled in the Patient Questionnaire on Therapy Expectation and Evaluation prior to treatment begin. Patients from the psychiatric hospital reported an average 1.41 negative effects, with 58.7% reporting at least one negative effect. Those from the psychosomatic hospital reported 0.76 negative effects on average, with 45.2% of patients reporting at least one negative effect. The differences between these samples are significant. The two samples' top three reported types of negative effects are that patients had experienced more downs during or just before the end of the therapy, that patients had difficulty making important decisions without the therapist, and that patients were concerned that colleagues or friends might find out about the therapy. A regression analysis revealed that the clinical setting (psychosomatic rehabilitation hospital vs. psychiatric hospital) and expectations in the form of hope of improvement were significant predictors for negative effects of psychotherapy. Our study highlights the need to examine the negative effects of psychotherapy in different settings and samples to better evaluate the benefit-cost ratios of treatments for different patient groups. It also shows that we need guidelines for assessing and reporting negative effects. Copyright © 2017 Elsevier Ireland Ltd. All rights reserved.

Is psychotherapy for functional somatic syndromes harmful? A mixed methods study on negative effects.

PubMed

Holsting, A F; Pedersen, H F; Rask, M T; Frostholm, L; Schröder, A

2017-07-01

Concern for negative effects of psychotherapy for functional somatic syndromes (FSS) has been expressed by clinicians and some patient associations, which may prevent patients from seeking treatment. Therefore, we sought to explore the occurrence and characteristics of negative effects from group-based psychotherapy as experienced by patients with severe or multiple FSS. An adapted version of the explanatory sequential mixed methods design was applied. We used data from an on-going pilot study on Acceptance and Commitment Therapy and Mindfulness-Based Stress Reduction. Negative effects were measured by Inventory for the assessment of Negative Effects of Psychotherapy (INEP). In addition, telephone interviews were conducted with randomly chosen patients and patients who reported negative effects. The latter were asked to elaborate on their INEP response. Quantitative data were analysed descriptively while interview transcripts were explored by thematic analysis. Eighty patients responded to the questionnaire (89%). Negative effects to different extent (from 'slightly agree' to 'fully agree') were reported by 25 (31%). The most frequent negative effects were dependence on the therapist (12%), feeling down after therapy (6%) and insurance problems (7%). By exploring 27 participants' experiences of negative effects 3 main themes were identified: relations in therapy, outcome and transition from therapy to everyday life. Patients with FSS reported a few specific negative effects, all with low frequency. Generally, therapy was well-received. Some patients did however express negative effects both within and outside the therapeutic context. It is important to inform patients about potential negative effects prior to psychotherapy. Copyright © 2017 Elsevier Inc. All rights reserved.

Understanding less than nothing: children's neural response to negative numbers shifts across age and accuracy.

PubMed

Gullick, Margaret M; Wolford, George

2013-01-01

We examined the brain activity underlying the development of our understanding of negative numbers, which are amounts lacking direct physical counterparts. Children performed a paired comparison task with positive and negative numbers during an fMRI session. As previously shown in adults, both pre-instruction fifth-graders and post-instruction seventh-graders demonstrated typical behavioral and neural distance effects to negative numbers, where response times and parietal and frontal activity increased as comparison distance decreased. We then determined the factors impacting the distance effect in each age group. Behaviorally, the fifth-grader distance effect for negatives was significantly predicted only by positive comparison accuracy, indicating that children who were generally better at working with numbers were better at comparing negatives. In seventh-graders, negative number comparison accuracy significantly predicted their negative number distance effect, indicating that children who were better at working with negative numbers demonstrated a more typical distance effect. Across children, as age increased, the negative number distance effect increased in the bilateral IPS and decreased frontally, indicating a frontoparietal shift consistent with previous numerical development literature. In contrast, as negative comparison task accuracy increased, the parietal distance effect increased in the left IPS and decreased in the right, possibly indicating a change from an approximate understanding of negatives' values to a more exact, precise representation (particularly supported by the left IPS) with increasing expertise. These shifts separately indicate the effects of increasing maturity generally in numeric processing and specifically in negative number understanding.

Right atrium cholinergic deficit in septic rats.

PubMed

Contreras, Paola; Migliaro, Eduardo R; Suhr, Bruno

2014-02-01

Heart rate variability (HRV) is mainly determined by the influence of both branches of the Autonomic Nervous System over the sinus node. Low HRV has been associated with a worse prognosis in patients with sepsis. The objective of this study was to explain the reduction in HRV during experimental sepsis in adult rats. We recorded the heart's electrical activity by telemetry in conscious unrestrained male rats before and 1day after the induction of peritonitis (N=39) or sham peritonitis (N=15). Then, we analyzed the chronotropic responsiveness of the isolated heart to the autonomic neurotransmitters and determined catecholamine concentrations in blood plasma and acetylcholine and choline concentrations in the right atrium. The surviving septic rats (N=33) had increased heart rate (HR) and diminished HRV. Despite the higher HR in situ, the spontaneous basal HR in septic and sham isolated hearts was the same. The isolated septic hearts showed acetylcholine hypersensitivity (log (IC50,M)=-7.2±0.2 vs. -6.0±0.4, P=0.025) and lower concentrations of choline in their right atriums (in nMol/mg protein: 0.6±0.1 vs. 1.6±0.6, P=0.013). Norepinephrine concentration in blood plasma from septic rats was higher (in ng/ml: 29.2±8.4 vs. 5.8±4.1, P=0.019). In conclusion, septic rats present a deregulation of the autonomic nervous system, not only sympathetic overexcitation but also parasympathetic dysfunction. © 2013.

Clinically oriented device programming in bradycardia patients: part 1 (sinus node disease). Proposals from AIAC (Italian Association of Arrhythmology and Cardiac Pacing).

PubMed

Ziacchi, Matteo; Palmisano, Pietro; Biffi, Mauro; Ricci, Renato P; Landolina, Maurizio; Zoni-Berisso, Massimo; Occhetta, Eraldo; Maglia, Giampiero; Botto, Gianluca; Padeletti, Luigi; Boriani, Giuseppe

2018-04-01

: Modern pacemakers have an increasing number of programable parameters and specific algorithms designed to optimize pacing therapy in relation to the individual characteristics of patients. When choosing the most appropriate pacemaker type and programing, the following variables must be taken into account: the type of bradyarrhythmia at the time of pacemaker implantation; the cardiac chamber requiring pacing, and the percentage of pacing actually needed to correct the rhythm disorder; the possible association of multiple rhythm disturbances and conduction diseases; the evolution of conduction disorders during follow-up. The goals of device programing are to preserve or restore the heart rate response to metabolic and hemodynamic demands; to maintain physiological conduction; to maximize device longevity; to detect, prevent, and treat atrial arrhythmia. In patients with sinus node disease, the optimal pacing mode is DDDR. Based on all the available evidence, in this setting, we consider appropriate the activation of the following algorithms: rate responsive function in patients with chronotropic incompetence; algorithms to maximize intrinsic atrioventricular conduction in the absence of atrioventricular blocks; mode-switch algorithms; algorithms for autoadaptive management of the atrial pacing output; algorithms for the prevention and treatment of atrial tachyarrhythmias in the subgroup of patients with atrial tachyarrhythmias/atrial fibrillation. The purpose of this two-part consensus document is to provide specific suggestions (based on an extensive literature review) on appropriate pacemaker setting in relation to patients' clinical features.

Potential negative ecological effects of corridors.

PubMed

Haddad, Nick M; Brudvig, Lars A; Damschen, Ellen I; Evans, Daniel M; Johnson, Brenda L; Levey, Douglas J; Orrock, John L; Resasco, Julian; Sullivan, Lauren L; Tewksbury, Josh J; Wagner, Stephanie A; Weldon, Aimee J

2014-10-01

Despite many studies showing that landscape corridors increase dispersal and species richness for disparate taxa, concerns persist that corridors can have unintended negative effects. In particular, some of the same mechanisms that underlie positive effects of corridors on species of conservation interest may also increase the spread and impact of antagonistic species (e.g., predators and pathogens), foster negative effects of edges, increase invasion by exotic species, increase the spread of unwanted disturbances such as fire, or increase population synchrony and thus reduce persistence. We conducted a literature review and meta-analysis to evaluate the prevalence of each of these negative effects. We found no evidence that corridors increase unwanted disturbance or non-native species invasion; however, these have not been well-studied concerns (1 and 6 studies, respectively). Other effects of corridors were more often studied and yielded inconsistent results; mean effect sizes were indistinguishable from zero. The effect of edges on abundances of target species was as likely to be positive as negative. Corridors were as likely to have no effect on antagonists or population synchrony as they were to increase those negative effects. We found 3 deficiencies in the literature. First, despite studies on how corridors affect predators, there are few studies of related consequences for prey population size and persistence. Second, properly designed studies of negative corridor effects are needed in natural corridors at scales larger than those achievable in experimental systems. Third, studies are needed to test more targeted hypotheses about when corridor-mediated effects on invasive species or disturbance may be negative for species of management concern. Overall, we found no overarching support for concerns that construction and maintenance of habitat corridors may result in unintended negative consequences. Negative edge effects may be mitigated by widening corridors or softening edges between corridors and the matrix. Other negative effects are relatively small and manageable compared with the large positive effects of facilitating dispersal and increasing diversity of native species. © 2014 Society for Conservation Biology.

Religious Engagement in a Risky Family Model Predicting Health in Older Black and White Seventh-day Adventists.

PubMed

Morton, Kelly R; Lee, Jerry W; Haviland, Mark G; Fraser, Gary E

2012-11-01

In a structural equation model, associations among latent variables - Child Poverty, Risky Family exposure, Religious Engagement, Negative Social Interactions, Negative Emotionality, and Perceived Physical Health - were evaluated in 6,753 Black and White adults aged 35-106 years (M = 60.5, SD = 13.0). All participants were members of the Seventh-day Adventist church surveyed in the Biopsychosocial Religion and Health Study (BRHS). Child Poverty was positively associated with both Risky Family exposure (conflict, neglect, abuse) and Religious Engagement (intrinsic religiosity, religious coping, religiousness). Risky Family was negatively associated with Religious Engagement and positively associated with both Negative Social Interactions (intrusive, failed to help, insensitive, rejecting) and Negative Emotionality (depression, negative affect, neuroticism). Religious Engagement was negatively associated with Negative Emotionality and Negative Social Interactions at a given level of risky family. Negative Social Interactions was positively associated with Negative Emotionality, which had a direct, negative effect on Perceived Physical Health. All constructs had indirect effects on Perceived Physical Health through Negative Emotionality. The effects of a risky family environment appear to be enduring, negatively affecting one's adult religious life, emotionality, social interactions, and perceived health. Religious engagement, however, may counteract the damaging effects of early life stress.

Planning what not to eat: ironic effects of implementation intentions negating unhealthy habits.

PubMed

Adriaanse, Marieke A; van Oosten, Johanna M F; de Ridder, Denise T D; de Wit, John B F; Evers, Catharine

2011-01-01

The present studies tested the effectiveness of implementation intentions with an "if [situation], then not [habitual response]" structure. Based on ironic process theory and the literature on the processing of negations, it was expected that these "negation implementation intentions" would, ironically, strengthen the habit (situation-response association) one aims to break. In line with the hypotheses, forming negation implementation intentions resulted in cognitive ironic rebound effects as well as behavioral ironic rebound effects compared to an intention only condition or a replacement implementation intention. Additionally, it was found that negation implementation intentions are most likely to result in ironic rebound effects when the habit to be negated is strong. Although implementation intentions are generally highly effective in facilitating behavior change even when this involves breaking unwanted habits, the present research suggests that they are ineffective when they have a negating structure.

The indirect effect of emotion dysregulation in terms of negative affect and smoking-related cognitive processes.

PubMed

Johnson, Adrienne L; McLeish, Alison C

2016-02-01

Although negative affect is associated with a number of smoking-related cognitive processes, the mechanisms underlying these associations have yet to be examined. The current study sought to examine the indirect effect of emotion regulation difficulties in terms of the association between negative affect and smoking-related cognitive processes (internal barriers to cessation, negative affect reduction smoking motives, negative affect reduction smoking outcome expectancies). Participants were 126 daily cigarette smokers (70.4% male, Mage=36.5years, SD=13.0; 69.8% Caucasian) who smoked an average of 18.5 (SD=8.7) cigarettes per day and reported moderate nicotine dependence. Formal mediation analyses were conducted using PROCESS to examine the indirect effect of negative affect on internal barriers to cessation and negative affect reduction smoking motives and outcome expectancies through emotion regulation difficulties. After accounting for the effects of gender, daily smoking rate, and anxiety sensitivity, negative affect was indirectly related to internal barriers to cessation and negative affect reduction smoking motives through emotion regulation difficulties. There was no significant indirect effect for negative affect reduction smoking outcome expectancies. These findings suggest that greater negative affect is associated with a desire to smoke to reduce this negative affect and perceptions that quitting smoking will be difficult due to negative emotions because of greater difficulties managing these negative emotions. Thus, emotion regulation difficulties may be an important target for smoking cessation interventions. Copyright © 2015 Elsevier Ltd. All rights reserved.

Religious Engagement in a Risky Family Model Predicting Health in Older Black and White Seventh-day Adventists

PubMed Central

Morton, Kelly R.; Lee, Jerry W.; Haviland, Mark G.; Fraser, Gary E.

2012-01-01

In a structural equation model, associations among latent variables – Child Poverty, Risky Family exposure, Religious Engagement, Negative Social Interactions, Negative Emotionality, and Perceived Physical Health – were evaluated in 6,753 Black and White adults aged 35–106 years (M = 60.5, SD = 13.0). All participants were members of the Seventh-day Adventist church surveyed in the Biopsychosocial Religion and Health Study (BRHS). Child Poverty was positively associated with both Risky Family exposure (conflict, neglect, abuse) and Religious Engagement (intrinsic religiosity, religious coping, religiousness). Risky Family was negatively associated with Religious Engagement and positively associated with both Negative Social Interactions (intrusive, failed to help, insensitive, rejecting) and Negative Emotionality (depression, negative affect, neuroticism). Religious Engagement was negatively associated with Negative Emotionality and Negative Social Interactions at a given level of risky family. Negative Social Interactions was positively associated with Negative Emotionality, which had a direct, negative effect on Perceived Physical Health. All constructs had indirect effects on Perceived Physical Health through Negative Emotionality. The effects of a risky family environment appear to be enduring, negatively affecting one’s adult religious life, emotionality, social interactions, and perceived health. Religious engagement, however, may counteract the damaging effects of early life stress. PMID:23560134

Negative affect, negative urgency, thought suppression, and bulimic symptoms: a moderated mediation analysis in a sample at-risk for bulimic symptoms.

PubMed

Lavender, Jason M; Green, Daniel; Anestis, Michael D; Tull, Matthew T; Gratz, Kim L

2015-05-01

Research suggests that negative affect, negative urgency, and thought suppression are related to bulimic symptoms, either directly or indirectly. This study examined associations between these constructs in a sample at-risk for bulimic symptoms. Participants (N = 80) recruited from a residential substance abuse treatment facility completed self-report questionnaires. A regression-based bootstrapping approach was used to examine the indirect effect of negative affect on bulimic symptoms through negative urgency and the moderating role of thought suppression in the association between negative affect and negative urgency. Results revealed a significant indirect effect, significant moderation, and a significant moderated mediation effect, with an indirect effect of negative affect on bulimic symptoms through negative urgency, conditional upon low to moderate (but not high) levels of thought suppression. These findings suggest that negative affect may promote rash actions, particularly in the context of low to moderate thought suppression, leading to increased risk of bulimic symptoms. Copyright © 2015 John Wiley & Sons, Ltd and Eating Disorders Association.

Brand Suicide? Memory and Liking of Negative Brand Names

PubMed Central

Guest, Duncan; Estes, Zachary; Gibbert, Michael; Mazursky, David

2016-01-01

Negative brand names are surprisingly common in the marketplace (e.g., Poison perfume; Hell pizza, and Monster energy drink), yet their effects on consumer behavior are currently unknown. Three studies investigated the effects of negative brand name valence on brand name memory and liking of a branded product. Study 1 demonstrates that relative to non-negative brand names, negative brand names and their associated logos are better recognised. Studies 2 and 3 demonstrate that negative valence of a brand name tends to have a detrimental influence on product evaluation with evaluations worsening as negative valence increases. However, evaluation is also dependent on brand name arousal, with high arousal brand names resulting in more positive evaluations, such that moderately negative brand names are equally as attractive as some non-negative brand names. Study 3 shows evidence for affective habituation, whereby the effects of negative valence reduce with repeated exposures to some classes of negative brand name. PMID:27023872

Brand Suicide? Memory and Liking of Negative Brand Names.

PubMed

Guest, Duncan; Estes, Zachary; Gibbert, Michael; Mazursky, David

2016-01-01

Negative brand names are surprisingly common in the marketplace (e.g., Poison perfume; Hell pizza, and Monster energy drink), yet their effects on consumer behavior are currently unknown. Three studies investigated the effects of negative brand name valence on brand name memory and liking of a branded product. Study 1 demonstrates that relative to non-negative brand names, negative brand names and their associated logos are better recognised. Studies 2 and 3 demonstrate that negative valence of a brand name tends to have a detrimental influence on product evaluation with evaluations worsening as negative valence increases. However, evaluation is also dependent on brand name arousal, with high arousal brand names resulting in more positive evaluations, such that moderately negative brand names are equally as attractive as some non-negative brand names. Study 3 shows evidence for affective habituation, whereby the effects of negative valence reduce with repeated exposures to some classes of negative brand name.

Turning negative into positive: public health mass media campaigns and negative advertising.

PubMed

Apollonio, D E; Malone, R E

2009-06-01

Literature suggests that 'negative advertising' is an effective way to encourage behavioral changes, but it has enjoyed limited use in public health media campaigns. However, as public health increasingly focuses on non-communicable disease prevention, negative advertising could be more widely applied. This analysis considers an illustrative case from tobacco control. Relying on internal tobacco industry documents, surveys and experimental data and drawing from political advocacy literature, we describe tobacco industry and public health research on the American Legacy Foundation's "truth" campaign, an example of effective negative advertising in the service of public health. The tobacco industry determined that the most effective advertisements run by Legacy's "truth" campaign were negative advertisements. Although the tobacco industry's own research suggested that these negative ads identified and effectively reframed the cigarette as a harmful consumer product rather than focusing solely on tobacco companies, Philip Morris accused Legacy of 'vilifying' it. Public health researchers have demonstrated the effectiveness of the "truth" campaign in reducing smoking initiation. Research on political advocacy demonstrating the value of negative advertising has rarely been used in the development of public health media campaigns, but negative advertising can effectively communicate certain public health messages and serve to counter corporate disease promotion.

Drinking Motives and Alcohol Outcome Expectancies as Mediators of the Association between Negative Urgency and Alcohol Consumption

PubMed Central

Anthenien, Amber M.; Lembo, Jordanna; Neighbors, Clayton

2017-01-01

Objective To determine whether the effects of negative urgency, a unique facet of impulsivity marked by engaging in potentially unhealthy and rash behaviors in order to cope with anxiety or negative moods, on drinking behavior can be explained by positive and negative alcohol outcome expectancies and specific drinking motives (i.e., coping and enhancement). Methods College students (N = 194) completed web-based surveys in exchange for course credit. Students completed measures of negative urgency, comprehensive effects of alcohol, drinking motives, and alcohol use behaviors. Results Results of path analysis indicated significant indirect effects of negative urgency and alcohol use through both alcohol outcome expectancies and enhancement motives. The effects of enhancement motives on drinking were mediated by positive alcohol outcome expectancies. The effects of coping motives on drinking were not attributable to negative expectancies. Conclusions Individuals high on negative urgency may consume alcohol in order to ameliorate their emotional distress due to strong desires to increase positive and decrease negative experiences associated with drinking. Emotion-focused impulsivity’s influence on drinking outcomes can be ascribed to enhancement motives for drinking as well as positive and negative alcohol outcome expectancies. Prevention efforts should target drinking motives and alcohol outcome expectancies among those higher in negative urgency. PMID:27914226

Drinking motives and alcohol outcome expectancies as mediators of the association between negative urgency and alcohol consumption.

PubMed

Anthenien, Amber M; Lembo, Jordanna; Neighbors, Clayton

2017-03-01

To determine whether the effects of negative urgency, a unique facet of impulsivity marked by engaging in potentially unhealthy and rash behaviors in order to cope with anxiety or negative moods, on drinking behavior can be explained by positive and negative alcohol outcome expectancies and specific drinking motives (i.e., coping and enhancement). College students (N=194) completed web-based surveys in exchange for course credit. Students completed measures of negative urgency, comprehensive effects of alcohol, drinking motives, and alcohol use behaviors. Results of path analysis indicated significant indirect effects of negative urgency and alcohol use through both alcohol outcome expectancies and enhancement motives. The effects of enhancement motives on drinking were mediated by positive alcohol outcome expectancies. The effects of coping motives on drinking were not attributable to negative expectancies. Individuals high on negative urgency may consume alcohol in order to ameliorate their emotional distress due to strong desires to increase positive and decrease negative experiences associated with drinking. Emotion-focused impulsivity's influence on drinking outcomes can be ascribed to enhancement motives for drinking as well as positive and negative alcohol outcome expectancies. Prevention efforts should target drinking motives and alcohol outcome expectancies among those higher in negative urgency. Copyright © 2016 Elsevier Ltd. All rights reserved.

Negative Life Events and Antenatal Depression among Pregnant Women in Rural China: The Role of Negative Automatic Thoughts.

PubMed

Wang, Yang; Wang, Xiaohua; Liu, Fangnan; Jiang, Xiaoning; Xiao, Yun; Dong, Xuehan; Kong, Xianglei; Yang, Xuemei; Tian, Donghua; Qu, Zhiyong

2016-01-01

Few studies have looked at the relationship between psychological and the mental health status of pregnant women in rural China. The current study aims to explore the potential mediating effect of negative automatic thoughts between negative life events and antenatal depression. Data were collected in June 2012 and October 2012. 495 rural pregnant women were interviewed. Depressive symptoms were measured by the Edinburgh postnatal depression scale, stresses of pregnancy were measured by the pregnancy pressure scale, negative automatic thoughts were measured by the automatic thoughts questionnaire, and negative life events were measured by the life events scale for pregnant women. We used logistic regression and path analysis to test the mediating effect. The prevalence of antenatal depression was 13.7%. In the logistic regression, the only socio-demographic and health behavior factor significantly related to antenatal depression was sleep quality. Negative life events were not associated with depression in the fully adjusted model. Path analysis showed that the eventual direct and general effects of negative automatic thoughts were 0.39 and 0.51, which were larger than the effects of negative life events. This study suggested that there was a potentially significant mediating effect of negative automatic thoughts. Pregnant women who had lower scores of negative automatic thoughts were more likely to suffer less from negative life events which might lead to antenatal depression.

[Progress of researches on the mechanism of cupping therapy].

PubMed

Cui, Shuai; Cui, Jin

2012-12-01

Cupping therapy of Chinese medicine is able to relieve a variety of diseases or clinical conditions, which results from the comprehensive effects of multiple types of stimulation exerted onto the regional acupoint areas. Among the stimuli, the negative pressure from cupping is one of the main factors inducing therapeutic effects. In the present paper, the authors review development of researches on the underlying mechanism of therapeutic effects of cupping-negative pressure from 1) the factor of intra-cup negative pressure; 2) influence of intra-cup negative pressure on cup-blackspot formation; 3) influence of cupping on regional blood vessels and blood flow; 4) effect of cupping on regional ultrastructure of the capillary in the raw-surface tissue; 5) effect of cupping-negative pressure on regional endothelial cells; and 6) biological effects of negative pressure drainage. Generally, cupping induced negative pressure can dilate local blood vessels to improve microcirculation, promote capillary endothelial cells repair, accelerate granulation and angiogenesis, etc., in the regional tissues, normalizing the patients' functional state at last.

Negative control exposure studies in the presence of measurement error: implications for attempted effect estimate calibration

PubMed Central

Sanderson, Eleanor; Macdonald-Wallis, Corrie; Davey Smith, George

2018-01-01

Abstract Background Negative control exposure studies are increasingly being used in epidemiological studies to strengthen causal inference regarding an exposure-outcome association when unobserved confounding is thought to be present. Negative control exposure studies contrast the magnitude of association of the negative control, which has no causal effect on the outcome but is associated with the unmeasured confounders in the same way as the exposure, with the magnitude of the association of the exposure with the outcome. A markedly larger effect of the exposure on the outcome than the negative control on the outcome strengthens inference that the exposure has a causal effect on the outcome. Methods We investigate the effect of measurement error in the exposure and negative control variables on the results obtained from a negative control exposure study. We do this in models with continuous and binary exposure and negative control variables using analysis of the bias of the estimated coefficients and Monte Carlo simulations. Results Our results show that measurement error in either the exposure or negative control variables can bias the estimated results from the negative control exposure study. Conclusions Measurement error is common in the variables used in epidemiological studies; these results show that negative control exposure studies cannot be used to precisely determine the size of the effect of the exposure variable, or adequately adjust for unobserved confounding; however, they can be used as part of a body of evidence to aid inference as to whether a causal effect of the exposure on the outcome is present. PMID:29088358

Negative control exposure studies in the presence of measurement error: implications for attempted effect estimate calibration.

PubMed

Sanderson, Eleanor; Macdonald-Wallis, Corrie; Davey Smith, George

2018-04-01

Negative control exposure studies are increasingly being used in epidemiological studies to strengthen causal inference regarding an exposure-outcome association when unobserved confounding is thought to be present. Negative control exposure studies contrast the magnitude of association of the negative control, which has no causal effect on the outcome but is associated with the unmeasured confounders in the same way as the exposure, with the magnitude of the association of the exposure with the outcome. A markedly larger effect of the exposure on the outcome than the negative control on the outcome strengthens inference that the exposure has a causal effect on the outcome. We investigate the effect of measurement error in the exposure and negative control variables on the results obtained from a negative control exposure study. We do this in models with continuous and binary exposure and negative control variables using analysis of the bias of the estimated coefficients and Monte Carlo simulations. Our results show that measurement error in either the exposure or negative control variables can bias the estimated results from the negative control exposure study. Measurement error is common in the variables used in epidemiological studies; these results show that negative control exposure studies cannot be used to precisely determine the size of the effect of the exposure variable, or adequately adjust for unobserved confounding; however, they can be used as part of a body of evidence to aid inference as to whether a causal effect of the exposure on the outcome is present.

Stressful Life Event Influences on Positive and Negative Psychological Functioning.

ERIC Educational Resources Information Center

McGowan, John R.; Cohen, Lawrence H.

Some research has suggested that positive life events may interact with negative life events during periods of high stress to buffer the effects of negative events. The relationships among positive and negative life events and positive and negative psychological status were examined in an investigation of the direct and mediating effects of…

The Peculiar Negative Greenhouse Effect Over Antarctica

NASA Astrophysics Data System (ADS)

Sejas, S.; Taylor, P. C.; Cai, M.

2017-12-01

Greenhouse gases warm the climate system by reducing the energy loss to space through the greenhouse effect. Thus, a common way to measure the strength of the greenhouse effect is by taking the difference between the surface longwave (LW) emission and the outgoing LW radiation. Based on this definition, a paradoxical negative greenhouse effect is found over the Antarctic Plateau, which suprisingly indicates that greenhouse gases enhance energy loss to space. Using 13 years of NASA satellite observations, we verify the existence of the negative greenhouse effect and find that the magnitude and sign of the greenhouse effect varies seasonally and spectrally. A previous explanation attributes the negative greenhouse effect solely to stratospheric CO2 and warmer than surface stratospheric temperatures. However, we surprisingly find that the negative greenhouse effect is predominantly caused by tropospheric water vapor. A novel principle-based explanation provides the first complete account of the Antarctic Plateau's negative greenhouse effect indicating that it is controlled by the vertical variation of temperature and greenhouse gas absorption strength. Our findings indicate that the strong surface-based temperature inversion and scarcity of free tropospheric water vapor over the Antarctic Plateau cause the negative greenhouse effect. These are climatological features uniquely found in the Antarctic Plateau region, explaining why the greenhouse effect is positive everywhere else.

Turning negative into positive: public health mass media campaigns and negative advertising

PubMed Central

Apollonio, D. E.; Malone, R. E.

2009-01-01

Literature suggests that ‘negative advertising’ is an effective way to encourage behavioral changes, but it has enjoyed limited use in public health media campaigns. However, as public health increasingly focuses on non-communicable disease prevention, negative advertising could be more widely applied. This analysis considers an illustrative case from tobacco control. Relying on internal tobacco industry documents, surveys and experimental data and drawing from political advocacy literature, we describe tobacco industry and public health research on the American Legacy Foundation’s “truth” campaign, an example of effective negative advertising in the service of public health. The tobacco industry determined that the most effective advertisements run by Legacy’s “truth” campaign were negative advertisements. Although the tobacco industry’s own research suggested that these negative ads identified and effectively reframed the cigarette as a harmful consumer product rather than focusing solely on tobacco companies, Philip Morris accused Legacy of ‘vilifying’ it. Public health researchers have demonstrated the effectiveness of the “truth” campaign in reducing smoking initiation. Research on political advocacy demonstrating the value of negative advertising has rarely been used in the development of public health media campaigns, but negative advertising can effectively communicate certain public health messages and serve to counter corporate disease promotion. PMID:18948569

Does infant negative emotionality moderate the effect of maternal depression on motor development?

PubMed

Sacchi, C; De Carli, P; Vieno, A; Piallini, G; Zoia, S; Simonelli, A

2018-04-01

Maternal depression represents an important social/environmental factor in early childhood; however, its effect on children's motor development may vary depending on the role of infants' dispositional variables. The objective of this study is to investigate the effect of the interaction between maternal depressive symptoms in the first two years of a child's life and the child's temperamental negative emotionality on motor development during this time. Using a cross-sectional study, we assessed 272 infants aged 0 to 24 months old and their mothers. We measured the following variables: maternal depression, infant's negative emotionality, and motor development. A three-way interaction effect highlights that negative emotionality in infants and maternal depression together affect children's overall motor growth trajectory. Infants with low negative emotionality display no effect of maternal depression on motor development. Conversely, infants with high negative emotionality seem to be more susceptible to the effect of maternal depression. Specifically, high maternal depression tends to foster the negative effect of infant's negativity on motor development across time, albeit not significantly. Finally, the absence of maternal depression significantly buffers negative temperament in infants. Findings highlighted the importance of integrating different perspectives when describing early motor growth. In fact, only when considering the interdependence of potential predictors their effect on the motor growth significantly emerges. Screening for early temperamental vulnerability might help in tailoring interventions to prevent maternal depression from affecting infants' motor development. Copyright © 2018 Elsevier B.V. All rights reserved.

How encompassing is the effect of negativity bias on political conservatism?

PubMed

Malka, Ariel; Soto, Christopher J

2014-06-01

We argue that the political effects of negativity bias are narrower than Hibbing et al. suggest. Negativity bias reliably predicts social, but not economic, conservatism, and its political effects often vary across levels of political engagement. Thus the role of negativity bias in broad ideological conflict depends on the strategic packaging of economic and social attitudes by political elites.

Negative dendritic effect on enzymatic hydrolysis of dendrimer conjugates.

PubMed

Zhou, Zhengwei; Cong, Mei; Li, Mengyao; Tintaru, Aura; Li, Jia; Yao, Jianhua; Xia, Yi; Peng, Ling

2018-06-08

Dendrimers possess intriguing "dendritic effects", which are unique characteristics that stem from the dendrimer generation and size. Here we report a "negative dendritic effect" observed during enzymatic hydrolysis of dendrimer conjugates. Such negative dendritic effects, though rarely reported, may be explored for tailored and generation-dependent drug release.

Negative Treatment Effects: Is It Time for a Black Box Warning?

ERIC Educational Resources Information Center

Boisvert, Charles M.

2010-01-01

Comments on Negative effects from psychological treatments: A perspective by David Barlow. The author addresses negative treatment effects in the psychotherapy field by stating that Barlow provided a historical perspective of clinical psychology's long-standing interest in studying the positive effects of psychotherapy, and he indicated that…

Social inhibition modulates the effect of negative emotions on cardiac prognosis following percutaneous coronary intervention in the drug-eluting stent era.

PubMed

Denollet, Johan; Pedersen, Susanne S; Ong, Andrew T L; Erdman, Ruud A M; Serruys, Patrick W; van Domburg, Ron T

2006-01-01

Negative emotions have an adverse effect on cardiac prognosis. We investigated whether social inhibition (inhibited self-expression in social interaction) modulates the effect of negative emotions on clinical outcome following percutaneous coronary intervention (PCI). Eight hundred and seventy-five consecutive patients from the RESEARCH registry (Erasmus Medical Centre, Rotterdam) completed depression, anxiety, negativity (negative emotions in general), and social inhibition scales 6 months following PCI. The endpoint was major adverse cardiac event (MACE-death, myocardial infarction, coronary artery bypass graft (CABG), or PCI) at 9 months following assessment. There were 100 MACE; patients who were high in both negativity and inhibition were at increased risk of MACE (38/254=15%) when compared with high negativity/low inhibition patients (13/136=10%; P=0.018). Depression (P=0.23) or anxiety (P=0.63) did not explain away this moderating effect of inhibition. High negativity/high inhibition (HR=1.92, 95%CI 1.22-3.01, P=0.005) and previous CABG (HR=1.90, 95%CI 1.04-3.47, P=0.038) were independent predictors of MACE. Patients with high negativity but low inhibition were not at increased risk (P=0.76). High negativity/high inhibition also independently predicted death/MI (n=20) as a more specific endpoint (HR=5.85, P=0.001). The interaction effect of social inhibition and negative emotions, rather than negative emotions per se, predicted poor clinical outcome following PCI. Social inhibition should not be overlooked as a modulating factor.

Evaluating the Separate and Combined Effects of Positive and Negative Reinforcement on Task Compliance

ERIC Educational Resources Information Center

Bouxsein, Kelly J.; Roane, Henry S.; Harper, Tara

2011-01-01

Positive and negative reinforcement are effective for treating escape-maintained destructive behavior. The current study evaluated the separate and combined effects of these contingencies to increase task compliance. Results showed that a combination of positive and negative reinforcement was most effective for increasing compliance. (Contains 1…

Negative incidental emotions augment fairness sensitivity.

PubMed

Liu, Cuizhen; Chai, Jing Wen; Yu, Rongjun

2016-04-22

Previous studies have shown that task-unrelated emotions induced incidentally exert carryover effects on individuals' subsequent decisions in financial negotiations. However, the specificity of these emotion effects are not clear. In three experiments, we systematically investigated the role of seven transiently induced basic emotions (disgust, sadness, anger, fear, happiness, surprise and neutral) on rejection of unfair offers using the ultimatum game. We found that all negative emotions (disgust, sadness, anger and fear), but not happiness or surprise, significantly increased rejection rates, suggesting that the effect of incidental negative emotions on fairness is not specific to the type of negative emotion. Our findings highlight the role of fleeting emotions in biasing decision-making processes and suggest that all incidental negative emotions exert similar effects on fairness sensitivity, possibly by potentiating attention towards negative aspects of the situation.

Ablation of PGC-1β Results in Defective Mitochondrial Activity, Thermogenesis, Hepatic Function, and Cardiac Performance

PubMed Central

Petrovic, Natasa; Kis, Adrienn; Feldmann, Helena M; Bjursell, Mikael; Parker, Nadeene; Curtis, Keira; Campbell, Mark; Hu, Ping; Zhang, Dongfang; Litwin, Sheldon E; Zaha, Vlad G; Fountain, Kimberly T; Boudina, Sihem; Jimenez-Linan, Mercedes; Blount, Margaret; Lopez, Miguel; Meirhaeghe, Aline; Bohlooly-Y, Mohammad; Storlien, Leonard; Strömstedt, Maria; Snaith, Michael; Orešič, Matej; Abel, E. Dale; Cannon, Barbara; Vidal-Puig, Antonio

2006-01-01

The transcriptional coactivator peroxisome proliferator-activated receptor-gamma coactivator-1β (PGC-1β) has been implicated in important metabolic processes. A mouse lacking PGC-1β (PGC1βKO) was generated and phenotyped using physiological, molecular, and bioinformatic approaches. PGC1βKO mice are generally viable and metabolically healthy. Using systems biology, we identified a general defect in the expression of genes involved in mitochondrial function and, specifically, the electron transport chain. This defect correlated with reduced mitochondrial volume fraction in soleus muscle and heart, but not brown adipose tissue (BAT). Under ambient temperature conditions, PGC-1β ablation was partially compensated by up-regulation of PGC-1α in BAT and white adipose tissue (WAT) that lead to increased thermogenesis, reduced body weight, and reduced fat mass. Despite their decreased fat mass, PGC1βKO mice had hypertrophic adipocytes in WAT. The thermogenic role of PGC-1β was identified in thermoneutral and cold-adapted conditions by inadequate responses to norepinephrine injection. Furthermore, PGC1βKO hearts showed a blunted chronotropic response to dobutamine stimulation, and isolated soleus muscle fibres from PGC1βKO mice have impaired mitochondrial function. Lack of PGC-1β also impaired hepatic lipid metabolism in response to acute high fat dietary loads, resulting in hepatic steatosis and reduced lipoprotein-associated triglyceride and cholesterol content. Altogether, our data suggest that PGC-1β plays a general role in controlling basal mitochondrial function and also participates in tissue-specific adaptive responses during metabolic stress. PMID:17090215

Design and rationale of the assessment of proper physiologic response with rate adaptive pacing driven by minute ventilation or accelerometer (APPROPRIATE) trial.

PubMed

Gilliam, F Roosevelt; Giudici, Michael; Benn, Andrew; Koplan, Bruce; Berg, Kellie Jean Chase; Kraus, Stacia Merkel; Stolen, Kira Q; Alvarez, Guy E; Hopper, Donald L; Wilkoff, Bruce L

2011-02-01

Rate-adaptive sensors are designed to restore a physiologic heart rate response to activity, in particular for patients that have chronotropic incompetence (CI). Limited data exist comparing two primary types of sensors; an accelerometer (XL) sensor which detects activity or motion and a minute ventilation (MV) sensor, which detects the product of respiration rate and tidal volume. The APPROPRIATE study will evaluate the MV sensor compared with the XL sensor for superiority in improving functional capacity (peak VO(2)) in pacemaker patients that have CI. This study is a double-blind, randomized, two-arm trial that will enroll approximately 1,000 pacemaker patients. Patients will complete a 6-min walk test at the 2-week visit to screen for potential CI. Those projected to have CI will advance to a 1-month visit. At the 1-month visit, final determination of CI will be done by completing a peak exercise treadmill test while the pacemaker is programmed to DDDR with the device sensors set to passive. Patients failing to meet the study criteria for CI will not continue further in the trial. Patients that demonstrate CI will be randomized to program their rate-adaptive sensors to either MV or XL in a 1:1 ratio. The rate-adaptive sensor will be optimized for each patient using a short walk to determine the appropriate response factor. At a 2-month visit, patients will complete a CPX test with the rate-adaptive sensors in their randomized setting.

Adrenergic responsiveness is reduced, while baseline cardiac function is preserved in old adult conscious monkeys

NASA Technical Reports Server (NTRS)

Sato, N.; Kiuchi, K.; Shen, Y. T.; Vatner, S. F.; Vatner, D. E.

1995-01-01

To examine the physiological deficit to adrenergic stimulation with aging, five younger adult (3 +/- 1 yr old) and nine older adult (17 +/- 1 yr old) healthy monkeys were studied after instrumentation with a left ventricular (LV) pressure gauge, aortic and left atrial catheters, and aortic flow probes to measure cardiac output directly. There were no significant changes in baseline hemodynamics in conscious older monkeys. For example, an index of contractility, the first derivative of LV pressure (LV dP/dt) was similar (3,191 +/- 240, young vs. 3,225 +/- 71 mmHg/s, old) as well as in isovolumic relaxation, tau (24.3 +/- 1.7 ms, young vs. 23.0 +/- 1.0 ms, old) was similar. However, inotropic, lusitropic, and chronotropic responses to isoproterenol (Iso; 0.1 micrograms/kg), norepinephrine (NE; 0.4 micrograms/kg), and forskolin (For; 75 nmol/kg) were significantly (P < 0.05) depressed in older monkeys. For example. Iso increased LV dP/dt by by 146 +/- 14% in younger monkeys and by only 70 +/- 5% in older monkeys. Iso also reduced tau more in younger monkeys (-28 +/- 7%) compared with older monkeys (-13 +/- 3%). Furthermore, peripheral vascular responsiveness to Iso, NE, For, and phenylephrine (PE; 5 micrograms/kg) was significantly (P < 0.05) reduced in older monkeys. For example, phenylephrine (5 micrograms/kg) increased total peripheral resistence by 69 +/- 4% in younger monkeys and by only 45 +/- 3% in older monkeys. Thus in older monkeys without associated cardiovascular disease, baseline hemodynamics are preserved, but adrenergic receptor responsiveness is reduced systemically, not just in the heart.

Is There a Paradox of Aging: When the Negative Aging Stereotype Meets the Positivity Effect in Older Adults.

PubMed

Zhou, Liqing; Lu, Jia; Chen, Guopeng; Dong, Li; Yao, Yujia

2017-01-01

Background/Study Context: Socioemotional selectivity theory (SST) states that the positivity effect is a result of older adults' emotion regulation and that older adults derive more emotional satisfaction from prioritizing positive information processing. The authors explored whether the positivity effect appeared when the negative aging stereotype was activated in older adults and also whether the effect differed between mixed and unmixed valence conditions. Sixty younger (18-23 years of age) and 60 older (60-87 years of age) adults were randomly assigned to a control group and a priming group, in which the negative aging stereotype was activated. All the participants were asked to select 15 words that best described the elderly from a mixed-word list (positive and negative words were mixed together) and from an unmixed-word list (positive and negative words were separated). Older adults in the control group selected more positive words, whereas among younger adults, selection did not differ by valence in either the mixed- or unmixed-word list conditions. There were no differences between the positive and negative word choices of the younger and older adults in the priming group. We calculated the differences between the numbers of positive and negative words, and the differences in the older adults' word choices were larger than those among the younger adults; the differences were also larger in the control group than in the priming group. The positivity effect worked by choosing positive stimuli rather than avoiding negative stimuli. The role of emotion regulation in older adults was limited, and when the positivity effect faced the effect of the negative aging stereotype, the negative stereotype effect was dominant. Future research should explore the changes in the positivity effect in the face of a positive aging stereotype and what roles other factors (e.g., activation level of the stereotype, arousal level of affective words) might play.

Combinatorial Effects of Lapatinib and Rapamycin in Triple-Negative Breast Cancer Cells

PubMed Central

Liu, Tongrui; Yacoub, Rami; Taliaferro-Smith, LaTonia D.; Sun, Shi-Yong; Graham, Tisheeka R.; Dolan, Ryan; Lobo, Christine; Tighiouart, Mourad; Yang, Lily; Adams, Amy; O'Regan, Ruth M.

2016-01-01

Triple-negative breast cancers, which lack estrogen receptor, progesterone receptor, and HER2/neu overexpression, account for approximately 15% of breast cancers, but occur more commonly in African Americans. The poor survival outcomes seen with triple-negative breast cancers patients are, in part, due to a lack of therapeutic targets. Epidermal growth factor receptor (EGFR) is overexpressed in 50% of triple-negative breast cancers, but EGFR inhibitors have not been effective in patients with metastatic breast cancers. However, mTOR inhibition has been shown to reverse resistance to EGFR inhibitors. We examined the combination effects of mTOR inhibition with EGFR inhibition in triple-negative breast cancer in vitro and in vivo. The combination of EGFR inhibition by using lapatinib and mTOR inhibition with rapamycin resulted in significantly greater cytotoxicity than the single agents alone and these effects were synergistic in vitro. The combination of rapamycin and lapatinib significantly decreased growth of triple-negative breast cancers in vivo compared with either agent alone. EGFR inhibition abrogated the expression of rapamycin-induced activated Akt in triple-negative breast cancer cells in vitro. The combination of EGFR and mTOR inhibition resulted in increased apoptosis in some, but not all, triple-negative cell lines, and these apoptotic effects correlated with a decrease in activated eukaryotic translation initiation factor (eIF4E). These results suggest that mTOR inhibitors could sensitize a subset of triple-negative breast cancers to EGFR inhibitors. Given the paucity of effective targeted agents in triple-negative breast cancers, these results warrant further evaluation. PMID:21690228

Interactive and Indirect Effects of Anxiety and Negative Urgency on Alcohol-Related Problems

PubMed Central

Menary, Kyle R.; Corbin, William R.; Leeman, Robert F.; Fucito, Lisa M.; Toll, Benjamin A.; DeMartini, Kelly; O’Malley, Stephanie S.

2015-01-01

Background Although drinking for tension reduction has long been posited as a risk factor for alcohol-related problems, studies investigating anxiety in relation to risk for alcohol problems have returned inconsistent results, leading researchers to search for potential moderators. Negative urgency (the tendency to become behaviorally dysregulated when experiencing negative affect) is a potential moderator of theoretical interest because it may increase risk for alcohol problems among those high in negative affect. The present study tested a cross-sectional mediated moderation hypothesis whereby an interactive effect of anxiety and negative urgency on alcohol problems is mediated through coping-related drinking motives. Method The study utilized baseline data from a hazardously drinking sample of young adults (N = 193) evaluated for participation in a randomized controlled trial of naltrexone and motivational interviewing for drinking reduction. Results The direct effect of anxiety on physiological dependence symptoms was moderated by negative urgency such that the positive association between anxiety and physiological dependence symptoms became stronger as negative urgency increased. Indirect effects of anxiety and negative urgency on alcohol problems (operating through coping motives) were also observed. Conclusions Although results of the current cross-sectional study require replication using longitudinal data, the findings suggest that the simultaneous presence of anxiety and negative urgency may be an important indicator of risk for AUDs via both direct interactive effects and indirect additive effects operating through coping motives. These findings have potentially important implications for prevention/intervention efforts for individuals who become disinhibited in the context of negative emotional states. PMID:26031346

The Emergence of Parent-Child Coercive Processes in Toddlerhood

PubMed Central

Chang, Hyein; Shaw, Daniel S.

2015-01-01

Parent-child coercion typically emerges in toddlerhood with the child’s first acts of willful defiance and the parent’s first disciplinary attempts. We explored how parents and children may contribute to this process by examining bidirectional and interactive effects between child and maternal negative behavior in 310 low-income, ethnically diverse boys. Using multiple informants and methods, child negative emotionality and maternal negative control were assessed at 18 months and child disruptive behavior and maternal negative control were measured at 24 months. Indicative of parent effects, maternal negative control at 18 months amplified the relation between children’s negative emotionality at 18 months and disruptive behavior at 24 months. Child effects were found in an unexpected direction such that children’s negative emotionality at 18 months predicted decreases in mothers’ negative control at 24 months. Findings are discussed within a transactional framework that emphasizes mutual influence of children and parents over the course of development. PMID:26068801

Age alters the cardiovascular response to direct passive heating

NASA Technical Reports Server (NTRS)

Minson, C. T.; Wladkowski, S. L.; Cardell, A. F.; Pawelczyk, J. A.; Kenney, W. L.

1998-01-01

During direct passive heating in young men, a dramatic increase in skin blood flow is achieved by a rise in cardiac output (Qc) and redistribution of flow from the splanchnic and renal vascular beds. To examine the effect of age on these responses, seven young (Y; 23 +/- 1 yr) and seven older (O; 70 +/- 3 yr) men were passively heated with water-perfused suits to their individual limit of thermal tolerance. Measurements included heart rate (HR), Qc (by acetylene rebreathing), central venous pressure (via peripherally inserted central catheter), blood pressures (by brachial auscultation), skin blood flow (from increases in forearm blood flow by venous occlusion plethysmography), splanchnic blood flow (by indocyanine green clearance), renal blood flow (by p-aminohippurate clearance), and esophageal and mean skin temperatures. Qc was significantly lower in the older than in the young men (11.1 +/- 0.7 and 7.4 +/- 0.2 l/min in Y and O, respectively, at the limit of thermal tolerance; P < 0. 05), despite similar increases in esophageal and mean skin temperatures and time to reach the limit of thermal tolerance. A lower stroke volume (99 +/- 7 and 68 +/- 4 ml/beat in Y and O, respectively, P < 0.05), most likely due to an attenuated increase in inotropic function during heating, was the primary factor for the lower Qc observed in the older men. Increases in HR were similar in the young and older men; however, when expressed as a percentage of maximal HR, the older men relied on a greater proportion of their chronotropic reserve to obtain the same HR response (62 +/- 3 and 75 +/- 4% maximal HR in Y and O, respectively, P < 0.05). Furthermore, the older men redistributed less blood flow from the combined splanchnic and renal circulations at the limit of thermal tolerance (960 +/- 80 and 720 +/- 100 ml/min in Y and O, respectively, P < 0. 05). As a result of these combined attenuated responses, the older men had a significantly lower increase in total blood flow directed to the skin.

40 CFR 57.816 - Effect of negative recommendation.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 5 2010-07-01 2010-07-01 false Effect of negative recommendation. 57.816 Section 57.816 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS... Reduction Technology § 57.816 Effect of negative recommendation. No waiver of the interim requirement for...

Effects of Creative Thinking and Its Personality Determinants on Negative Emotion Regulation.

PubMed

Chiu, Fa-Chung; Hsu, Chih-Chun; Lin, Yao-Nan; Liu, Cheng-Hong; Chen, Hsueh-Chih; Lin, Chi-Hsiang

2018-01-01

This study investigated the relationship between creativity and negative emotion, and the effects of integrating creative insight into the reappraisal process on negative emotions. In Study 1, participants' creativity and baseline anxiety levels were measured; then anxiety was induced, and anxiety levels were reassessed. In Study 2, participants wrote about past negative events and then completed the positive and negative affect schedule. They were split into three groups (insight reappraisal, simple reappraisal, or control groups); each of them received a separate intervention, and then they completed positive and negative affect schedule again. In Study 3, participants were randomly assigned to insight reappraisal or control groups; apart from measuring cognitive changes, the procedures were identical to Study 2. All participants were undergraduate students. Results showed that flexibility, originality, risk-taking, and complexity are negatively correlated with anxiety, and that insight reappraisal can induce insight experience and enhance cognitive changes, and reduce negative emotional responses. Therefore, integrating creative insight into the reappraisal process can enhance its effectiveness in reducing negative emotions.

Moderating effects of coping on work stress and job performance for nurses in tertiary hospitals: a cross-sectional survey in China.

PubMed

Li, Li; Ai, Hua; Gao, Lei; Zhou, Hao; Liu, Xinyan; Zhang, Zhong; Sun, Tao; Fan, Lihua

2017-06-12

Work stress is a major problem for nurses and it can negatively influence job performance. Therefore, it is critical to explore variables that can reduce or buffer the negative effects of work stress. This study explores the moderating effects of coping strategies on the relationship between work stress and job performance for nurses in China. A cross-sectional survey of 852 nurses from four tertiary hospitals in Heilongjiang Province, China, was conducted in 2013. Descriptive statistics were reported for socioeconomic status and demographic characteristics, level of work stress, coping strategies, and job performance. Regression analysis was conducted to test the interaction between work stress and coping strategies on job performance. Three subscales of work stress were negatively related to job performance. Positive coping strategies moderated Patient Care and job performance while negative coping strategies moderated Workload and Time and performance, and between Working Environment and Resources and performance. Positive coping strategies reduce or buffer the negative effects of work stress on job performance and negative coping strategies increased the negative effects.

The Unique Effects of Parental Alcohol and Affective Disorders, Parenting, and Parental Negative Affect on Adolescent Maladjustment

PubMed Central

Haller, Moira; Chassin, Laurie

2010-01-01

Using a high-risk community sample, multiple regression analyses were conducted separately for mothers (N=416) and fathers (N= 346) to test the unique, prospective influence of parental negative affect on adolescent maladjustment (internalizing symptoms, externalizing symptoms, and negative emotionality) two years later over and above parental alcohol and affective disorders, major disruption in the family environment, and parenting. Adolescent sex was tested as a moderator. Results indicated that maternal (but not paternal) negative affect had a unique, prospective effect on adolescent internalizing symptoms in girls and negative emotionality in both sexes, but did not predict adolescent externalizing symptoms. Findings demonstrate that mothers’ negative affect may have unique effects on adolescent adjustment, separate from the effects of clinically significant parental psychopathology, parenting, and disruption in the family environment. PMID:23761947

The Unique Effects of Parental Alcohol and Affective Disorders, Parenting, and Parental Negative Affect on Adolescent Maladjustment.

PubMed

Haller, Moira; Chassin, Laurie

2011-07-01

Using a high-risk community sample, multiple regression analyses were conducted separately for mothers ( N =416) and fathers ( N = 346) to test the unique, prospective influence of parental negative affect on adolescent maladjustment (internalizing symptoms, externalizing symptoms, and negative emotionality) two years later over and above parental alcohol and affective disorders, major disruption in the family environment, and parenting. Adolescent sex was tested as a moderator. Results indicated that maternal (but not paternal) negative affect had a unique, prospective effect on adolescent internalizing symptoms in girls and negative emotionality in both sexes, but did not predict adolescent externalizing symptoms. Findings demonstrate that mothers' negative affect may have unique effects on adolescent adjustment, separate from the effects of clinically significant parental psychopathology, parenting, and disruption in the family environment.

Negative incidental emotions augment fairness sensitivity

PubMed Central

Liu, Cuizhen; Chai, Jing Wen; Yu, Rongjun

2016-01-01

Previous studies have shown that task-unrelated emotions induced incidentally exert carryover effects on individuals’ subsequent decisions in financial negotiations. However, the specificity of these emotion effects are not clear. In three experiments, we systematically investigated the role of seven transiently induced basic emotions (disgust, sadness, anger, fear, happiness, surprise and neutral) on rejection of unfair offers using the ultimatum game. We found that all negative emotions (disgust, sadness, anger and fear), but not happiness or surprise, significantly increased rejection rates, suggesting that the effect of incidental negative emotions on fairness is not specific to the type of negative emotion. Our findings highlight the role of fleeting emotions in biasing decision-making processes and suggest that all incidental negative emotions exert similar effects on fairness sensitivity, possibly by potentiating attention towards negative aspects of the situation. PMID:27101931

Effectiveness and cost-effectiveness of body psychotherapy in the treatment of negative symptoms of schizophrenia--a multi-centre randomised controlled trial.

PubMed

Priebe, Stefan; Savill, Mark; Reininghaus, Ulrich; Wykes, Til; Bentall, Richard; Lauber, Christoph; McCrone, Paul; Röhricht, Frank; Eldridge, Sandra

2013-01-14

Negative symptoms of schizophrenia are frequently associated with poor long term outcomes. Established interventions have little, if any, positive effects on negative symptoms. Arts Therapies such as Body Psychotherapy (BPT) have been suggested to reduce negative symptoms, but the existing evidence is limited. In a small exploratory trial a manualised form of group BPT led to significantly lower negative symptom levels both at the end of treatment and at 4 months follow-up as compared to supportive counseling. We designed a large multi-site trial to assess the effectiveness of a manualised BPT intervention in reducing negative symptoms, compared to an active control. In a randomised controlled trial, 256 schizophrenic outpatients with negative symptoms will be randomly allocated either to BPT or Pilates groups. In both conditions, patients will be offered two 90 minutes sessions per week in groups of about 8 patients over a period of 10 weeks. Outcomes are assessed at the end of treatment and at six months follow-up. The primary outcome is severity of negative symptoms, as measured by the Positive and Negative Symptom Scale (PANSS), whilst a range of secondary outcome measures include general psychopathology, social contacts, and quality of life. We will also assess the cost-effectiveness of the intervention. The study aims to evaluate the effectiveness of a promising form of group therapy which may help alleviate negative symptoms that are associated with unfavourable long-term outcomes and have so far been difficult to treat. If the trial is successful, it will add a new and effective option in the treatment of negative symptoms. Group BPT is manualised, might be attractive to many patients because of its unusual approach, and could potentially be rolled out to services at relatively little additional cost. Current Controlled Trials ISRCTN84216587.

Effectiveness and cost-effectiveness of body psychotherapy in the treatment of negative symptoms of schizophrenia – a multi-centre randomised controlled trial

PubMed Central

2013-01-01

Background Negative symptoms of schizophrenia are frequently associated with poor long term outcomes. Established interventions have little, if any, positive effects on negative symptoms. Arts Therapies such as Body Psychotherapy (BPT) have been suggested to reduce negative symptoms, but the existing evidence is limited. In a small exploratory trial a manualised form of group BPT led to significantly lower negative symptom levels both at the end of treatment and at 4 months follow-up as compared to supportive counseling. We designed a large multi-site trial to assess the effectiveness of a manualised BPT intervention in reducing negative symptoms, compared to an active control. Methods/Design In a randomised controlled trial, 256 schizophrenic outpatients with negative symptoms will be randomly allocated either to BPT or Pilates groups. In both conditions, patients will be offered two 90 minutes sessions per week in groups of about 8 patients over a period of 10 weeks. Outcomes are assessed at the end of treatment and at six months follow-up. The primary outcome is severity of negative symptoms, as measured by the Positive and Negative Symptom Scale (PANSS), whilst a range of secondary outcome measures include general psychopathology, social contacts, and quality of life. We will also assess the cost-effectiveness of the intervention. Discussion The study aims to evaluate the effectiveness of a promising form of group therapy which may help alleviate negative symptoms that are associated with unfavourable long-term outcomes and have so far been difficult to treat. If the trial is successful, it will add a new and effective option in the treatment of negative symptoms. Group BPT is manualised, might be attractive to many patients because of its unusual approach, and could potentially be rolled out to services at relatively little additional cost. Trial registration Current Controlled Trials ISRCTN84216587 PMID:23317474

40 CFR 57.816 - Effect of negative recommendation.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 5 2011-07-01 2011-07-01 false Effect of negative recommendation. 57... Reduction Technology § 57.816 Effect of negative recommendation. No waiver of the interim requirement for... or a State first takes into account the Administrator's report, findings, and recommendations as to...

There was not, they did not: May negation cause the negated ideas to be remembered as existing?

PubMed Central

2017-01-01

In this article we demonstrate that negation of ideas can have paradoxical effects, possibly leading the listener to believe that the negated ideas actually existed. In Experiment 1, participants listened to a description of a house, in which some objects were mentioned, some were negated, and some were not mentioned at all. When questioned about the existence of these objects a week later, the participants gave more false positives for items that were negated in the original material than for items that were not mentioned at all, an effect we call negation related false memories (NRFM). The NRFM effect was replicated again in Experiment 2 with a sample of five and six year-old children. Experiment 3 confirmed NRFM in the case of negated actions. The results are discussed in terms of retention hypothesis, as well as the theory that negation can activate a representation of an entity and behaviour. It is also indicated that future research is needed to ensure that it is indeed negation which caused false alarms, not merely mentioning an object. PMID:28448549

Negative affectivity: moderator or confound in emotional dissonance-outcome relationships?

PubMed

Abraham, R

1999-01-01

This study was an examination of the impact of negative affectivity on relationships between emotional dissonance, job satisfaction, and emotional exhaustion. Negative affectivity is the predisposition to view life in negative terms. Emotional dissonance originates from the conflict between expressed and experienced emotions. In organizations that require the expression of positive emotions, high negative affectivity individuals may experience conflict between expressed, positive emotions and felt, negative emotions. A moderator effect exists when high negative affectivity individuals experience greater job dissatisfaction and emotional exhaustion. Alternatively, negative affectivity may exert a confounding effect through its relationship to both emotional dissonance and its outcomes. Empirical tests showed that negative affectivity moderated the emotional dissonance-job satisfaction relationship and confounded the emotional dissonance-emotional exhaustion relationship.

Brain Processing of Emotional Scenes in Aging: Effect of Arousal and Affective Context

PubMed Central

Mathieu, Nicolas Gilles; Gentaz, Edouard; Harquel, Sylvain; Vercueil, Laurent; Chauvin, Alan; Bonnet, Stéphane; Campagne, Aurélie

2014-01-01

Research on emotion showed an increase, with age, in prevalence of positive information relative to negative ones. This effect is called positivity effect. From the cerebral analysis of the Late Positive Potential (LPP), sensitive to attention, our study investigated to which extent the arousal level of negative scenes is differently processed between young and older adults and, to which extent the arousal level of negative scenes, depending on its value, may contextually modulate the cerebral processing of positive (and neutral) scenes and favor the observation of a positivity effect with age. With this aim, two negative scene groups characterized by two distinct arousal levels (high and low) were displayed into two separate experimental blocks in which were included positive and neutral pictures. The two blocks only differed by their negative pictures across participants, as to create two negative global contexts for the processing of the positive and neutral pictures. The results show that the relative processing of different arousal levels of negative stimuli, reflected by LPP, appears similar between the two age groups. However, a lower activity for negative stimuli is observed with the older group for both tested arousal levels. The processing of positive information seems to be preserved with age and is also not contextually impacted by negative stimuli in both younger and older adults. For neutral stimuli, a significantly reduced activity is observed for older adults in the contextual block of low-arousal negative stimuli. Globally, our study reveals that the positivity effect is mainly due to a modulation, with age, in processing of negative stimuli, regardless of their arousal level. It also suggests that processing of neutral stimuli may be modulated with age, depending on negative context in which they are presented to. These age-related effects could contribute to justify the differences in emotional preference with age. PMID:24932857

The Effects of Anger, Sadness and Happiness on Persuasive Message Processing: A Test of the Negative State Relief Model.

ERIC Educational Resources Information Center

Mitchell, Monique M.; Brown, Kenneth M.; Morris-Villagran, Melinda; Villagran, Paul D.

2001-01-01

Examines the strength of the effects of happiness and sadness on attitude change, and compares these effects with the effect of anger on attitude change and persuasive message processing. Finds that message strength was positively correlated with attitude, intention and behavior, but was negatively correlated with negative thoughts, and counter…

Exploring the Relationship between Negative Urgency and Dysregulated Eating: Etiologic Associations and the Role of Negative Affect

PubMed Central

Racine, Sarah E.; Keel, Pamela K.; Burt, S. Alexandra; Sisk, Cheryl L.; Neale, Michael; Boker, Steven; Klump, Kelly L.

2013-01-01

Negative urgency (i.e., the tendency to engage in rash action in response to negative affect) has emerged as a critical personality trait contributing to individual differences in binge eating. However, studies investigating the extent to which genetic and/or environmental influences underlie the effects of negative urgency on binge eating are lacking. Moreover, it remains unclear whether negative urgency-binge eating associations are simply due to the well-established role of negative affect in the development/maintenance of binge eating. The current study addresses these gaps by examining phenotypic and etiologic associations between negative urgency, negative affect, and dysregulated eating (i.e., binge eating, emotional eating) in a sample of 222 same-sex female twin pairs from the Michigan State Twin Registry. Negative urgency was significantly associated with both dysregulated eating symptoms, even after controlling for the effects of negative affect. Genetic factors accounted for the majority (62–77%) of this phenotypic association, although a significant proportion of this genetic covariation was due to genetic influences in common with negative affect. Non-shared environmental factors accounted for a relatively smaller (23–38%) proportion of the association, but these non-shared environmental effects were independent of negative affect. Findings suggest that the presence of emotion-based rash action, combined with high levels of negative affect, may significantly increase genetic risk for dysregulated eating. PMID:23356217

Exploring the relationship between negative urgency and dysregulated eating: etiologic associations and the role of negative affect.

PubMed

Racine, Sarah E; Keel, Pamela K; Burt, S Alexandra; Sisk, Cheryl L; Neale, Michael; Boker, Steven; Klump, Kelly L

2013-05-01

Negative urgency (i.e., the tendency to engage in rash action in response to negative affect) has emerged as a critical personality trait contributing to individual differences in binge eating. However, studies investigating the extent to which genetic and/or environmental influences underlie the effects of negative urgency on binge eating are lacking. Moreover, it remains unclear whether negative urgency-binge eating associations are simply a result of the well-established role of negative affect in the development/maintenance of binge eating. The current study addresses these gaps by examining phenotypic and etiologic associations between negative urgency, negative affect, and dysregulated eating (i.e., binge eating, emotional eating) in a sample of 222 same-sex female twin pairs from the Michigan State University Twin Registry. Negative urgency was significantly associated with both dysregulated eating symptoms, even after controlling for the effects of negative affect. Genetic factors accounted for the majority (62-77%) of this phenotypic association, although a significant proportion of this genetic covariation was due to genetic influences in common with negative affect. Nonshared environmental factors accounted for a relatively smaller (23-38%) proportion of the association, but these nonshared environmental effects were independent of negative affect. Findings suggest that the presence of emotion-based rash action, combined with high levels of negative affect, may significantly increase genetic risk for dysregulated eating. © 2013 American Psychological Association

Species differences in the negative inotropic effect of acetylcholine and soman in rat, guinea pig, and rabbit hearts. (Reannouncement with new availability information)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Maxwell, D.M.; Thomsen, R.H.; Baskin, S.I.

1991-12-31

Acetylcholine reduced atrial contractions by 82.5% in guinea pig, 50.8% in rat, and 41.5% in rabbit. 2. The EC50, values for the negative inotropic effect of acetylcholine were 3.3 x 10(-7) M in rat and guinea pig atria and 4.1 x 10(-6) M in rabbit atria. 3. There was no correlation between the species differences in the negative inotropic effect of acetylcholine in atria and the density or affinity of acetylcholinesterase or muscarinic receptors. 4. Inhibition of atrial acetylcholinesterase with soman reduced the EC50 of acetylcholine three-fold in all species, but did not change the maximal inotropic effect of acetylcholine.more » 5. Species differences in the negative inotropic effect of acetylcholine may be caused by differences in the coupling between myocardial muscarinic receptors and the ion channels that mediate negative inotropy. Acetylcholine, cardiovascular response, species variation negative inotropic response.« less

Manipulating affective state influences conditioned appetitive responses.

PubMed

Arnaudova, Inna; Krypotos, Angelos-Miltiadis; Effting, Marieke; Kindt, Merel; Beckers, Tom

2017-10-06

Affective states influence how individuals process information and behave. Some theories predict emotional congruency effects (e.g. preferential processing of negative information in negative affective states). Emotional congruency should theoretically obstruct the learning of reward associations (appetitive learning) and their ability to guide behaviour under negative mood. Two studies tested the effects of the induction of a negative affective state on appetitive Pavlovian learning, in which neutral stimuli were associated with chocolate (Experiment 1) or alcohol (Experiment 2) rewards. In both experiments, participants showed enhanced approach tendencies towards predictors of reward after a negative relative to a positive performance feedback manipulation. This increase was related to a reduction in positive affect in Experiment 1 only. No effects of the manipulation on conditioned reward expectancies, craving, or consumption were observed. Overall, our findings support the idea of counter-regulation, rather than emotional congruency effects. Negative affective states might therefore serve as a vulnerability factor for addiction, through increasing conditioned approach tendencies.

Further Investigating Method Effects Associated with Negatively Worded Items on Self-Report Surveys

ERIC Educational Resources Information Center

DiStefano, Christine; Motl, Robert W.

2006-01-01

This article used multitrait-multimethod methodology and covariance modeling for an investigation of the presence and correlates of method effects associated with negatively worded items on the Rosenberg Self-Esteem (RSE) scale (Rosenberg, 1989) using a sample of 757 adults. Results showed that method effects associated with negative item phrasing…

Commitment to Nonwork Roles and Job Performance: Enrichment and Conflict Perspectives

ERIC Educational Resources Information Center

Weer, Christy H.; Greenhaus, Jeffrey H.; Linnehan, Frank

2010-01-01

An extensive commitment to nonwork roles was negatively associated with the job performance of 182 women legal secretaries. In addition to its direct negative effect on job performance, nonwork role commitment had both a negative indirect effect (through emotional energy expended on nonwork roles) and a positive indirect effect (through resources…

Prosocial Behavior Mitigates the Negative Effects of Stress in Everyday Life

PubMed Central

Raposa, Elizabeth B.; Laws, Holly B.; Ansell, Emily B.

2015-01-01

Recent theories of stress reactivity posit that, when stressed, individuals tend to seek out opportunities to affiliate with and nurture others in order to prevent or mitigate the negative effects of stress. However, few studies have tested empirically the role of prosocial behavior in reducing negative emotional responses to stress. The current analyses used daily diary data to investigate whether engaging in prosocial behavior buffered the negative effects of naturally-occurring stressors on emotional well-being. Results showed that on a given day, prosocial behavior moderated the effects of stress on positive affect, negative affect, and overall mental health. Findings suggest that affiliative behavior may be an important component of coping with stress, and indicate that engaging in prosocial behavior might be an effective strategy for reducing the impact of stress on emotional functioning. PMID:27500075

Prosocial Behavior Mitigates the Negative Effects of Stress in Everyday Life.

PubMed

Raposa, Elizabeth B; Laws, Holly B; Ansell, Emily B

2016-07-01

Recent theories of stress reactivity posit that, when stressed, individuals tend to seek out opportunities to affiliate with and nurture others in order to prevent or mitigate the negative effects of stress. However, few studies have tested empirically the role of prosocial behavior in reducing negative emotional responses to stress. The current analyses used daily diary data to investigate whether engaging in prosocial behavior buffered the negative effects of naturally-occurring stressors on emotional well-being. Results showed that on a given day, prosocial behavior moderated the effects of stress on positive affect, negative affect, and overall mental health. Findings suggest that affiliative behavior may be an important component of coping with stress, and indicate that engaging in prosocial behavior might be an effective strategy for reducing the impact of stress on emotional functioning.

Gender, negative life events and coping on different stages of depression severity: A cross-sectional study among Chinese university students.

PubMed

Sun, Xiao-Jun; Niu, Geng-Feng; You, Zhi-Qi; Zhou, Zong-Kui; Tang, Yun

2017-02-01

The effects of gender, negative life events, and coping on depression have been well-documented. But depression is a heterogeneous syndrome of which the severity ranged from mild depression to major depression. This study aimed to investigate the specific effects of gender, negative life events, and coping on different stages of depression severity. A total of 5989 students (aged 16-25 years, M=20.85, SD=0.58), recruited from six universities in the central region of China using the stratified cluster sampling method, completed Life Events Questionnaire, Coping Response Inventory, and Beck Depression Inventory-Ⅱ. Among the participants, 708 (11.8%) students presented different severity levels of depression. Gender, negative life events, positive coping, and negative coping all had significant effects on depression. That is, the possibility of being depressed was significantly higher in female university students, or students who had more negative life events, more negative coping, or positive coping. In terms of the different stages of depression severity, all these factors had significant effects on the stage from non- depression to mild depression; only gender, negative life events and positive coping had significant effects on the stage from mild depression to moderate depression; only gender had a significant effect on the stage from moderate depression to major depression. The causal role of these factors on different stages of depression severity could not be inferred. Moreover, the participants were from a non-clinical population. The effects of gender, negative life events and coping varied in different stages of depression severity. The effects of life events and coping styles became insignificant with the increasing severity of depression, whereas the effect of gender remained significant. The results could provide guidance for the prevention, intervention, and treatment of depression. Copyright © 2016. Published by Elsevier B.V.

The therapeutic effect of negative pressure in treating femoral head necrosis in rabbits.

PubMed

Zhang, Yin-gang; Wang, Xuezhi; Yang, Zhi; Zhang, Hong; Liu, Miao; Qiu, Yushen; Guo, Xiong

2013-01-01

Because negative pressure can stimulate vascular proliferation, improve blood circulation and promote osteogenic differentiation of bone marrow stromal cells, we investigated the therapeutic effect of negative pressure on femoral head necrosis (FHN) in a rabbit model. Animals were divided into four groups (n = 60/group): [1] model control, [2] core decompression, [3] negative pressure and [4] normal control groups. Histological investigation revealed that at 4 and 8 weeks postoperatively, improvements were observed in trabecular bone shape, empty lacunae and numbers of bone marrow hematopoietic cells and fat cells in the negative pressure group compared to the core decompression group. At week 8, there were no significant differences between the negative pressure and normal control groups. Immunohistochemistry staining revealed higher expression of vascular endothelial growth factor (VEGF) and bone morphogenetic protein-2 (BMP-2) in the femoral heads in the negative pressure group compared with the core decompression group. Transmission electron microscopy revealed that cell organelles were further developed in the negative pressure group compared with the core decompression group. Microvascular ink staining revealed an increased number of bone marrow ink-stained blood vessels, a thicker vascular lumen and increased microvascular density in the negative pressure group relative to the core decompression group. Real-time polymerase chain reaction revealed that expression levels of both VEGF and BMP-2 were higher in the negative pressure group compared with the core decompression group. In summary, negative pressure has a therapeutic effect on FHN. This effect is superior to core decompression, indicating that negative pressure is a potentially valuable method for treating early FHN.

The Therapeutic Effect of Negative Pressure in Treating Femoral Head Necrosis in Rabbits

PubMed Central

Zhang, Yin-gang; Wang, Xuezhi; Yang, Zhi; Zhang, Hong; Liu, Miao; Qiu, Yushen; Guo, Xiong

2013-01-01

Because negative pressure can stimulate vascular proliferation, improve blood circulation and promote osteogenic differentiation of bone marrow stromal cells, we investigated the therapeutic effect of negative pressure on femoral head necrosis (FHN) in a rabbit model. Animals were divided into four groups (n = 60/group): [1] model control, [2] core decompression, [3] negative pressure and [4] normal control groups. Histological investigation revealed that at 4 and 8 weeks postoperatively, improvements were observed in trabecular bone shape, empty lacunae and numbers of bone marrow hematopoietic cells and fat cells in the negative pressure group compared to the core decompression group. At week 8, there were no significant differences between the negative pressure and normal control groups. Immunohistochemistry staining revealed higher expression of vascular endothelial growth factor (VEGF) and bone morphogenetic protein-2 (BMP-2) in the femoral heads in the negative pressure group compared with the core decompression group. Transmission electron microscopy revealed that cell organelles were further developed in the negative pressure group compared with the core decompression group. Microvascular ink staining revealed an increased number of bone marrow ink-stained blood vessels, a thicker vascular lumen and increased microvascular density in the negative pressure group relative to the core decompression group. Real-time polymerase chain reaction revealed that expression levels of both VEGF and BMP-2 were higher in the negative pressure group compared with the core decompression group. In summary, negative pressure has a therapeutic effect on FHN. This effect is superior to core decompression, indicating that negative pressure is a potentially valuable method for treating early FHN. PMID:23383276

Bidirectional-Compounding Effects of Rumination and Negative Emotion in Predicting Impulsive Behavior: Implications for Emotional Cascades.

PubMed

Selby, Edward A; Kranzler, Amy; Panza, Emily; Fehling, Kara B

2016-04-01

Influenced by chaos theory, the emotional cascade model proposes that rumination and negative emotion may promote each other in a self-amplifying cycle that increases over time. Accordingly, exponential-compounding effects may better describe the relationship between rumination and negative emotion when they occur in impulsive persons, and predict impulsive behavior. Forty-seven community and undergraduate participants who reported frequent engagement in impulsive behaviors monitored their ruminative thoughts and negative emotion multiple times daily for two weeks using digital recording devices. Hypotheses were tested using cross-lagged mixed model analyses. Findings indicated that rumination predicted subsequent elevations in rumination that lasted over extended periods of time. Rumination and negative emotion predicted increased levels of each other at subsequent assessments, and exponential functions for these associations were supported. Results also supported a synergistic effect between rumination and negative emotion, predicting larger elevations in subsequent rumination and negative emotion than when one variable alone was elevated. Finally, there were synergistic effects of rumination and negative emotion in predicting number of impulsive behaviors subsequently reported. These findings are consistent with the emotional cascade model in suggesting that momentary rumination and negative emotion progressively propagate and magnify each other over time in impulsive people, promoting impulsive behavior. © 2014 Wiley Periodicals, Inc.

Understanding the factors that determine registered nurses' turnover intentions.

PubMed

Osuji, Joseph; Uzoka, Faith-Michael; Aladi, Flora; El-Hussein, Mohammed

2014-01-01

Turnover among registered nurses (RNs) produces a negative impact on the health outcomes of any health care organization. It is also recognized universally as a problem in the nursing profession. Little is known about the turnover intentions and career orientations of RNs working in Calgary, Alberta, Canada. The aim of this study is to contribute to the knowledge of and to advance the discussion on the turnover of nursing professionals. The study population consisted of RNs employed in the five major hospitals in Calgary. There were 193 surveys returned, representing a response rate of 77.2%. The results show that age and education have a negative effect on turnover intention. Education was found to have a significant negative effect on career satisfaction but not on job satisfaction and organizational commitment. Length of service has a significant negative effect on turnover intention. Role ambiguity has significant highly negative effect on career satisfaction. Growth opportunity and supervisor support have a very significant positive effect on job satisfaction, career satisfaction, and organizational commitment. External career opportunities and organizational commitment do not seem to have a significant effect on turnover intention. Career satisfaction, on the other hand, had negative significant effects on turnover intention.

Neural Correlates of Biased Responses: The Negative Method Effect in the Rosenberg Self-Esteem Scale Is Associated with Right Amygdala Volume.

PubMed

Wang, Yinan; Kong, Feng; Huang, Lijie; Liu, Jia

2016-10-01

Self-esteem is a widely studied construct in psychology that is typically measured by the Rosenberg Self-Esteem Scale (RSES). However, a series of cross-sectional and longitudinal studies have suggested that a simple and widely used unidimensional factor model does not provide an adequate explanation of RSES responses due to method effects. To identify the neural correlates of the method effect, we sought to determine whether and how method effects were associated with the RSES and investigate the neural basis of these effects. Two hundred and eighty Chinese college students (130 males; mean age = 22.64 years) completed the RSES and underwent magnetic resonance imaging (MRI). Behaviorally, method effects were linked to both positively and negatively worded items in the RSES. Neurally, the right amygdala volume negatively correlated with the negative method factor, while the hippocampal volume positively correlated with the general self-esteem factor in the RSES. The neural dissociation between the general self-esteem factor and negative method factor suggests that there are different neural mechanisms underlying them. The amygdala is involved in modulating negative affectivity; therefore, the current study sheds light on the nature of method effects that are related to self-report with a mix of positively and negatively worded items. © 2015 Wiley Periodicals, Inc.

A Comparative Study on the Effects of Negative Evidence and Enriched Input on Learning of Verb-Noun Collocations

ERIC Educational Resources Information Center

Okyar, Hatice; Yangin Eksi, Gonca

2017-01-01

This study compared the effectiveness of negative evidence and enriched input on learning the verb-noun collocations. There were 52 English as Foreign Language (EFL) learners in this research study and they were randomly assigned to the negative evidence or enriched input groups. While the negative evidence group (n = 27) was provided with…

Dependency, self-criticism and negative affective responses following imaginary rejection and failure threats: meaning-making processes as moderators or mediators.

PubMed

Besser, Avi; Priel, Beatriz

2011-01-01

This study evaluated the intervening role of meaning-making processes in emotional responses to negative life events based on Blatt's (1974, 2004) formulations concerning the role of personality predispositions in depression. In a pre/post within-subject study design, a community sample of 233 participants reacted to imaginary scenarios of interpersonal rejection and achievement failure. Meaning-making processes relating to threats to self-definition and interpersonal relatedness were examined following the exposure to the scenarios. The results indicated that the personality predisposition of Dependency, but not Self-Criticism predicted higher levels of negative affect following the interpersonal rejection event, independent of baseline levels of negative affect. This effect was mediated by higher levels of negative meaning-making processes related to the effect of the interpersonal rejection scenario on Dependent individuals' senses of interpersonal relatedness and self-worth. In addition, both Self-Criticism and Dependency predicted higher levels of negative affect following the achievement failure event, independent of baseline levels of negative affect. Finally, the effect of Self-Criticism was mediated by higher levels of negative meaning-making processes related to the effect of the achievement failure scenario on self-critical individuals' senses of self-definition.

Influence of negative emotion on the framing effect: evidence from event-related potentials.

PubMed

Ma, Qingguo; Pei, Guanxiong; Wang, Kai

2015-04-15

The framing effect is the phenomenon in which different descriptions of an identical problem can result in different choices. The influence of negative emotions on the framing effect and its neurocognitive basis are important issues, especially in the domain of saving lives, which is essential and highly risky. In each trial of our experiment, the emotion stimulus is presented to the participants, followed by the decision-making stimulus, which comprises certain and risky options with the same expected value. Each pair of options is positively or negatively framed. The behavioral results indicate a significant interactive effect between negative emotion and frame; thus, the risk preference under the positive frame can be enhanced by negative emotions, whereas this finding is not true under the negative frame. The event-related potential analysis indicates that choosing certain options under the positive frame with negative emotion priming generates smaller P2 and P3 amplitudes and a larger N2 amplitude than with neutral emotion priming. The event-related potential findings indicate that individuals can detect risk faster and experience more conflict and increased decision difficulty if they choose certain options under the positive frame with negative priming compared with neutral priming.

No fear, no panic: probing negation as a means for emotion regulation

PubMed Central

Deutsch, Roland; Platte, Petra; Pauli, Paul

2013-01-01

This electroencephalographic study investigated if negating one’s emotion results in paradoxical effects or leads to effective emotional downregulation. Healthy participants were asked to downregulate their emotions to happy and fearful faces by using negated emotional cue words (e.g. no fun, no fear). Cue words were congruent with the emotion depicted in the face and presented prior to each face. Stimuli were presented in blocks of happy and fearful faces. Blocks of passive stimulus viewing served as control condition. Active regulation reduced amplitudes of early event-related brain potentials (early posterior negativity, but not N170) and the late positive potential for fearful faces. A fronto-central negativity peaking at about 250 ms after target face onset showed larger amplitude modulations during downregulation of fearful and happy faces. Behaviorally, negating was more associated with reappraisal than with suppression. Our results suggest that in an emotional context, negation processing could be quite effective for emotional downregulation but that its effects depend on the type of the negated emotion (pleasant vs unpleasant). Results are discussed in the context of dual process models of cognition and emotion regulation. PMID:22490924

The effects of positive versus negative impact reflection on change in job performance and work-life conflict.

PubMed

Cardador, M Teresa

2014-01-01

Research on task significance and relational job design suggests that information from beneficiaries of one's work fosters perceptions of impact, and thus improved work outcomes. This paper presents results from a longitudinal field experiment examining the effect of another strategy for fostering perceptions of impact - engaging employees in regular reflection about how their work benefits others. With a sample of professionals from multiple organizations, this longitudinal study examined the effect on job performance and work-life conflict of both positive and negative impact reflection. Results show that negative impact reflection had a pronounced negative effect on job performance, but no effect on work-life conflict. Positive impact reflection had a weak positive effect on work-life conflict, but no significant effect on job performance. The direction of effects seen in the no intervention condition mirrored that of the negative impact reflection condition, suggesting a possible buffering effect for positive impact reflection. This research provides empirical and theoretical contributions to the literatures on relational job design and task significance.

The effects of positive versus negative impact reflection on change in job performance and work-life conflict

PubMed Central

Cardador, M. Teresa

2014-01-01

Research on task significance and relational job design suggests that information from beneficiaries of one’s work fosters perceptions of impact, and thus improved work outcomes. This paper presents results from a longitudinal field experiment examining the effect of another strategy for fostering perceptions of impact – engaging employees in regular reflection about how their work benefits others. With a sample of professionals from multiple organizations, this longitudinal study examined the effect on job performance and work-life conflict of both positive and negative impact reflection. Results show that negative impact reflection had a pronounced negative effect on job performance, but no effect on work-life conflict. Positive impact reflection had a weak positive effect on work-life conflict, but no significant effect on job performance. The direction of effects seen in the no intervention condition mirrored that of the negative impact reflection condition, suggesting a possible buffering effect for positive impact reflection. This research provides empirical and theoretical contributions to the literatures on relational job design and task significance. PMID:25505890

The effect of negative experiences on delinquent behavior of youth in a social withdrawal situation.

PubMed

Chan, Gloria Hongyee; Lo, T Wing

2016-07-01

This study examines the relationship between negative experiences, negative emotions, and delinquent behavior among young people in a social withdrawal situation. There were 533 participants in this study and various quantitative analyses were utilized. Results showed that participants with a longer period of social withdrawal were generally less affected by negative experiences, while those with a higher level of social withdrawal were more affected by negative experiences, particularly negative relationships with other people. Also, both negative emotions and higher level of social withdrawal mediated the relationship between negative experiences and involvement in delinquent behavior, with negative emotions displaying a higher mediating effect. This reflects that the root of delinquent behavior is the negative experiences which arouse negative emotions, rather than the social withdrawal behavior itself. Results imply that practitioners should first explore the negative experiences suffered by these young people, so as to provide them the most appropriate support. Copyright © 2016 The Foundation for Professionals in Services for Adolescents. Published by Elsevier Ltd. All rights reserved.

Emotion dysregulation explains the relation between insomnia symptoms and negative reinforcement smoking cognitions among daily smokers.

PubMed

Kauffman, Brooke Y; Farris, Samantha G; Alfano, Candice A; Zvolensky, Michael J

2017-09-01

Insomnia co-occurs with smoking. However, mechanisms that may explain their comorbidity are not well known. The present study tested the hypothesis that insomnia would exert an indirect effect on negative reinforcement smoking processes via emotion dysregulation among 126 adult non-treatment seeking daily smokers (55 females; M age =44.1years, SD=9.72). Negative reinforcement smoking processes included negative reinforcement smoking outcome expectancies, negative reinforcement smoking motives, and two negative expectancies from brief smoking abstinence (somatic symptoms and harmful consequences). Insomnia symptoms yielded a significant indirect effect through emotion dysregulation for negative reinforcement smoking outcome expectancies, negative reinforcement smoking motives, and harmful consequences expectancies from brief smoking abstinence. In contrast to prediction, however, insomnia was not associated with somatic symptom expectancies from brief smoking abstinence through emotion dysregulation. These data may suggest that the indirect effect of emotion dysregulation is more relevant to cognitive-affective negative reinforcement processes rather than somatic states. Overall, the present findings contribute to a growing body of literature linking emotion dysregulation as an explanatory mechanism for insomnia and smoking and uniquely extend such work to an array of clinically significant negative reinforcement smoking processes. Copyright © 2017 Elsevier Ltd. All rights reserved.

Saint-Venant end effects for materials with negative Poisson's ratios

NASA Technical Reports Server (NTRS)

Lakes, R. S.

1992-01-01

Results are presented from an analysis of Saint-Venant end effects for materials with negative Poisson's ratio. Examples are presented showing that slow decay of end stress occurs in circular cylinders of negative Poisson's ratio, whereas a sandwich panel containing rigid face sheets and a compliant core exhibits no anomalous effects for negative Poisson's ratio (but exhibits slow stress decay for core Poisson's ratios approaching 0.5). In sand panels with stiff but not perfectly rigid face sheets, a negative Poisson's ratio results in end stress decay, which is faster than it would be otherwise. It is suggested that the slow decay previously predicted for sandwich strips in plane deformation as a result of the geometry can be mitigated by the use of a negative Poisson's ratio material for the core.

Reconsolidation from negative emotional pictures: is successful retrieval required?

PubMed

Finn, Bridgid; Roediger, Henry L; Rosenzweig, Emily

2012-10-01

Finn and Roediger (Psychological science 22:781-786, 2011) found that when a negative emotional picture was presented immediately after a successful retrieval, later test performance was enhanced as compared to when a neutral picture or a blank screen had been shown. This finding implicates the period immediately following retrieval as playing an important role in determining later retention via reconsolidation. In two new experiments, we investigated whether successful retrieval was required to show the enhancing effect of negative emotion on later recall. In both experiments, the participants studied Swahili-English vocabulary pairs, took an intervening cued-recall test, and were given a final cued-recall test on all items. In Experiment 1, we tested a distinctiveness explanation of the effect. The results showed that neither presentation of a negative picture just prior to successful retrieval nor presentation of a positive picture after successful retrieval produced the enhancing effect that was seen when negative pictures were presented after successful retrieval. In Experiment 2, we tested whether the enhancing effect would occur when a negative picture followed an unsuccessful retrieval attempt with feedback, and a larger enhancement effect occurred after errors of commission than after errors of omission. These results indicate that effort in retrieving is critical to the enhancing effect shown with negative pictures; whether the target is produced by the participant or given by an external source following a commission error does not matter. We interpret these results as support for semantic enrichment as a key element in producing the enhancing effect of negative pictures that are presented after a retrieval attempt.

Positive smoking outcome expectancies mediate the association between negative affect and smoking urge among women during a quit attempt.

PubMed

Cano, Miguel Ángel; Lam, Cho Y; Chen, Minxing; Adams, Claire E; Correa-Fernández, Virmarie; Stewart, Diana W; McClure, Jennifer B; Cinciripini, Paul M; Wetter, David W

2014-08-01

Ecological momentary assessment was used to examine associations between negative affect, positive smoking outcome expectancies, and smoking urge during the first 7 days of a smoking quit attempt. Participants were 302 female smokers who enrolled in an individually tailored smoking cessation treatment study. Multilevel mediation analysis was used to examine the temporal relationship among the following: (a) the effects of negative affect and positive smoking outcome expectancies at 1 assessment point (e.g., time j) on smoking urge at the subsequent time point (e.g., time j + 1) in Model 1; and, (b) the effects of negative affect and smoking urge at time j on positive smoking outcome expectancies at time j + 1 in Model 2. The results from Model 1 showed a statistically significant effect of negative affect at time j on smoking urge at time j + 1, and this effect was mediated by positive smoking outcome expectancies at time j, both within- and between-participants. In Model 2, the within-participant indirect effect of negative affect at time j on positive smoking outcome expectancies at time j + 1 through smoking urge at time j was nonsignificant. However, a statistically significant indirect between-participants effect was found in Model 2. The findings support the hypothesis that urge and positive smoking outcome expectancies increase as a function of negative affect, and suggest a stronger effect of expectancies on urge as opposed to the effect of urge on expectancies.

Positive Smoking Outcome Expectancies Mediate the Association between Negative Affect and Smoking Urge among Women During a Quit Attempt

PubMed Central

Cano, Miguel Ángel; Lam, Cho Y.; Chen, Minxing; Adams, Claire E.; Correa-Fernández, Virmarie; Stewart, Diana W.; McClure, Jennifer B.; Cinciripini, Paul M.; Wetter, David W.

2014-01-01

Ecological momentary assessment was used to examine associations between negative affect, positive smoking outcome expectancies, and smoking urge during the first 7 days of a smoking quit attempt. Participants were 302 female smokers who enrolled in an individually tailored smoking cessation treatment study. Multilevel mediation analysis was used to examine the temporal relationship among: 1) the effects of negative affect and positive smoking outcome expectancies at one assessment point (e.g., time j) on smoking urge at the subsequent time point (e.g., time j + 1) in Model 1; and, 2) the effects of negative affect and smoking urge at time j on positive smoking outcome expectancies at time j + 1 in Model 2. The results from Model 1 showed a statistically significant effect of negative affect at time j on smoking urge at time j + 1, and this effect was mediated by positive smoking outcome expectancies at time j, both within- and between-participant. In Model 2, the within-participant indirect effect of negative affect at time j on positive smoking outcome expectancies at time j + 1 through smoking urge at time j was nonsignificant. However, a statistically significant indirect between-participant effect was found in Model 2. The findings support the hypothesis that urge and positive smoking outcome expectancies increase as a function of negative affect, and suggest a stronger effect of expectancies on urge as opposed to the effect of urge on expectancies. PMID:24796849

Indirect effect of financial strain on daily cortisol output through daily negative to positive affect index in the Coronary Artery Risk Development in Young Adults Study.

PubMed

Puterman, Eli; Haritatos, Jana; Adler, Nancy E; Sidney, Steve; Schwartz, Joseph E; Epel, Elissa S

2013-12-01

Daily affect is important to health and has been linked to cortisol. The combination of high negative affect and low positive affect may have a bigger impact on increasing HPA axis activity than either positive or negative affect alone. Financial strain may both dampen positive affect as well as increase negative affect, and thus provides an excellent context for understanding the associations between daily affect and cortisol. Using random effects mixed modeling with maximum likelihood estimation, we examined the relationship between self-reported financial strain and estimated mean daily cortisol level (latent cortisol variable), based on six salivary cortisol assessments throughout the day, and whether this relationship was mediated by greater daily negative to positive affect index measured concurrently in a sample of 776 Coronary Artery Risk Development in Young Adults (CARDIA) Study participants. The analysis revealed that while no total direct effect existed for financial strain on cortisol, there was a significant indirect effect of high negative affect to low positive affect, linking financial strain to elevated cortisol. In this sample, the effects of financial strain on cortisol through either positive affect or negative affect alone were not significant. A combined affect index may be a more sensitive and powerful measure than either negative or positive affect alone, tapping the burden of chronic financial strain, and its effects on biology. Copyright © 2013 Elsevier Ltd. All rights reserved.

Rotavirus vaccine effectiveness in low-income settings: An evaluation of the test-negative design.

PubMed

Schwartz, Lauren M; Halloran, M Elizabeth; Rowhani-Rahbar, Ali; Neuzil, Kathleen M; Victor, John C

2017-01-03

The test-negative design (TND), an epidemiologic method currently used to measure rotavirus vaccine (RV) effectiveness, compares the vaccination status of rotavirus-positive cases and rotavirus-negative controls meeting a pre-defined case definition for acute gastroenteritis. Despite the use of this study design in low-income settings, the TND has not been evaluated to measure rotavirus vaccine effectiveness. This study builds upon prior methods to evaluate the use of the TND for influenza vaccine using a randomized controlled clinical trial database. Test-negative vaccine effectiveness (VE-TND) estimates were derived from three large randomized placebo-controlled trials (RCTs) of monovalent (RV1) and pentavalent (RV5) rotavirus vaccines in sub-Saharan Africa and Asia. Derived VE-TND estimates were compared to the original RCT vaccine efficacy estimates (VE-RCTs). The core assumption of the TND (i.e., rotavirus vaccine has no effect on rotavirus-negative diarrhea) was also assessed. TND vaccine effectiveness estimates were nearly equivalent to original RCT vaccine efficacy estimates. Neither RV had a substantial effect on rotavirus-negative diarrhea. This study supports the TND as an appropriate epidemiologic study design to measure rotavirus vaccine effectiveness in low-income settings. Copyright © 2016 The Author(s). Published by Elsevier Ltd.. All rights reserved.

Immediate effects of chocolate on experimentally induced mood states.

PubMed

Macht, Michael; Mueller, Jochen

2007-11-01

In this work two hypotheses were tested: (1) that eating a piece of chocolate immediately affects negative, but not positive or neutral mood, and (2) that this effect is due to palatability. Experiment 1 (48 normal-weight and healthy women and men) examined the effects of eating a piece of chocolate and drinking water on negative, positive and neutral mood states induced by film clips. Eating chocolate reduced negative mood compared to drinking water, whereas no or only marginal effects were found on neutral and positive moods. Experiment 2 (113 normal-weight and healthy women and men) compared effects of eating palatable and unpalatable chocolate on negative mood, and examined the duration of chocolate-induced mood change. Negative mood was improved after eating palatable chocolate as compared to unpalatable chocolate or nothing. This effect was short lived, i.e., it disappeared after 3 min. In both experiments, chocolate-induced mood improvement was associated with emotional eating. The present studies demonstrate that eating a small amount of sweet food improves an experimentally induced negative mood state immediately and selectively and that this effect of chocolate is due to palatability. It is hypothesized that immediate mood effects of palatable food contribute to the habit of eating to cope with stress.

Meta-atom cluster acoustic metamaterial with broadband negative effective mass density

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chen, Huaijun; Zhai, Shilong; Ding, Changlin

2014-02-07

We design a resonant meta-atom cluster, via which a two-dimensional (2D) acoustic metamaterial (AM) with broadband negative effective mass density from 1560 Hz to 5580 Hz is fabricated. Experimental results confirm that there is only weak interaction among the meta-atoms in the cluster. And then the meta-atoms in the cluster independently resonate, resulting in the cluster becoming equivalent to a broadband resonance unit. Extracted effective refractive indices from reflection and transmission measurements of the 2D AM appear to be negative from 1500 Hz to 5480 Hz. The broadband negative refraction has also been demonstrated by our further experiments. We expectmore » that this meta-atom cluster AM will significantly contribute to the design of broadband negative effective mass density AM.« less

Mutual Influence of Reward Anticipation and Emotion on Brain Activity during Memory Retrieval.

PubMed

Yan, Chunping; Liu, Fang; Li, Yunyun; Zhang, Qin; Cui, Lixia

2017-01-01

Previous studies on the joint effect of reward motivation and emotion on memory retrieval have obtained inconsistent results. Furthermore, whether and how any such joint effect might vary over time remains unclear too. Accordingly, using the event-related potential (ERP) measurement of high temporal resolution, our study investigates the cognitive and brain mechanisms of monetary reward and emotion affecting the retrieval processes of episodic memory. Twenty undergraduate and graduate students participated in the research, and our study's behavioral results indicated that reward (relative to no reward) and negative emotion (relative to positive and neutral emotion) significantly improved recognition performance. The ERP results showed that there were significant interactions between monetary reward and emotion on memory retrieval, and the reward effects of positive, neutral, and negative memory occurred at varied intervals in mean amplitude. The reward effect of positive memory appeared relatively early, at 260-330 ms after the stimulus onset in the frontal-frontocentral area, at 260-500 ms in the centroparietal-parietal area and at 500-700 ms in the frontocentral area. However, the reward effects of neutral and negative memory occurred relatively later, and that of negative memory appeared at 500-700 ms in the frontocentral and centroparietal area and that of neutral memory was at 500-700 ms in the frontocentral and centroparietal-parietal area. Meanwhile, significant FN400 old/new effects were observed in the negative and rewarded positive items, and the old/new effects of negative items appeared earlier at FN400 than positive items. Also, significant late positive component (LPC) old/new effects were found in the positive, negative, and rewarded neutral items. These results suggest that, monetary reward and negative emotion significantly improved recognition performance, and there was a mutual influence between reward and emotion on brain activity during memory retrieval.

General Rule of Negative Effective Ueff System & Materials Design of High-Tc Superconductors by ab initio Calculations

NASA Astrophysics Data System (ADS)

Katayama-Yoshida, Hiroshi; Nakanishi, Akitaka; Uede, Hiroki; Takawashi, Yuki; Fukushima, Tetsuya; Sato, Kazunori

2014-03-01

Based upon ab initio electronic structure calculation, I will discuss the general rule of negative effective U system by (1) exchange-correlation-induced negative effective U caused by the stability of the exchange-correlation energy in Hund's rule with high-spin ground states of d5 configuration, and (2) charge-excitation-induced negative effective U caused by the stability of chemical bond in the closed-shell of s2, p6, and d10 configurations. I will show the calculated results of negative effective U systems such as hole-doped CuAlO2 and CuFeS2. Based on the total energy calculations of antiferromagnetic and ferromagnetic states, I will discuss the magnetic phase diagram and superconductivity upon hole doping. I also discuss the computational materials design method of high-Tc superconductors by ab initio calculation to go beyond LDA and multi-scale simulations.

[Negative symptoms of schizophrenia: from electrophysiology to electrotherapy].

PubMed

Micoulaud Franchi, J-A; Quiles, C; Belzeaux, R; Adida, M; Azorin, J-M

2015-12-01

The aim of this review of the literature is to summarize the state of the knowledge concerning the relationship between negative symptoms in schizophrenia, electrophysiology and electrotherapy. The scientific literature search of international articles was performed during August and September 2015 using the PubMed electronic database. We used the following MeSH terms: "Negative symptoms", "Schizophrenia", "Electrophysiology", "Neurophysiology", "EEG power", "Alpha rhythm", "Transcranial magnetic stimulation", "Transcranial direct current stimulation", "Electroconvulsive therapy", "Neurofeedback", "Vagus Nerve Stimulation", "Deep Brain Stimulation", and "State dependent". Negative symptoms in schizophrenia are associated with altered activity in prefrontal cortex in functional neuroimaging studies. This is in line with electrophysiological measurements that found a change in EEG spectral power in the alpha frequency band over prefrontal brain regions. The notion of functional hypofrontality has led to hypotheses that electrotherapy applied to the prefrontal cortex may be an effective treatment of negative symptoms in schizophrenia. Repetitive transcranial magnetic stimulation (rTMS) and transcranial direct current stimulation (tDCS) were used to increase cortical activity in schizophrenia and achieve a clinical effect on negative symptoms. Three meta-analyses confirmed, with a moderate effect size, that rTMS is an effective treatment option for negative symptoms in schizophrenia. The two subsequently published prospective multicenter studies, however, found opposite results from each other. Two randomized controlled studies suggested that tDCS is an effective treatment option for negative symptoms. There is no study on the efficacy of neurofeedback, vagal nerve stimulation or deep brain stimulation on negative symptoms in schizophrenia. Additional studies are needed to confirm the efficacy of rTMS and tDCS on negative symptoms in schizophrenia. Influencing factors, related to clinical and stimulation parameters, of rTMS and tDCS on negative symptoms should be better investigated. Effects related to electrophysiological brain activity of the patient, especially in the alpha band, during the stimulation should also be better investigated. The action of electrotherapy may be state dependent, and a better understanding of electrophysiological effects of electrotherapy techniques could enable their optimization. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

Dose reduction of risperidone and olanzapine can improve cognitive function and negative symptoms in stable schizophrenic patients: A single-blinded, 52-week, randomized controlled study.

PubMed

Zhou, Yanling; Li, Guannan; Li, Dan; Cui, Hongmei; Ning, Yuping

2018-05-01

The long-term effects of dose reduction of atypical antipsychotics on cognitive function and symptomatology in stable patients with schizophrenia remain unclear. We sought to determine the change in cognitive function and symptomatology after reducing risperidone or olanzapine dosage in stable schizophrenic patients. Seventy-five stabilized schizophrenic patients prescribed risperidone (≥4 mg/day) or olanzapine (≥10 mg/day) were randomly divided into a dose-reduction group ( n=37) and a maintenance group ( n=38). For the dose-reduction group, the dose of antipsychotics was reduced by 50%; for the maintenance group, the dose remained unchanged throughout the whole study. The Positive and Negative Syndrome Scale, Negative Symptom Assessment-16, Rating Scale for Extrapyramidal Side Effects, and Measurement and Treatment Research to Improve Cognition in Schizophrenia (MATRICS) Consensus Cognitive Battery were measured at baseline, 12, 28, and 52 weeks. Linear mixed models were performed to compare the Positive and Negative Syndrome Scale, Negative Symptom Assessment-16, Rating Scale for Extrapyramidal Side Effects and MATRICS Consensus Cognitive Battery scores between groups. The linear mixed model showed significant time by group interactions on the Positive and Negative Syndrome Scale negative symptoms, Negative Symptom Assessment-16, Rating Scale for Extrapyramidal Side Effects, speed of processing, attention/vigilance, working memory and total score of MATRICS Consensus Cognitive Battery (all p<0.05). Post hoc analyses showed significant improvement in Positive and Negative Syndrome Scale negative subscale, Negative Symptom Assessment-16, Rating Scale for Extrapyramidal Side Effects, speed of processing, working memory and total score of MATRICS Consensus Cognitive Battery for the dose reduction group compared with those for the maintenance group (all p<0.05). This study indicated that a risperidone or olanzapine dose reduction of 50% may not lead to more severe symptomatology but can improve speed of processing, working memory and negative symptoms in patients with stabilized schizophrenia.

The Effect of Drawing Exercises on Mood When Negative Affect Is Not Induced

ERIC Educational Resources Information Center

Northcott, Jessica L.; Frein, Scott T.

2017-01-01

In this study we examined the effects of drawing on positive and negative affect, when negative mood induction is not used as has been done in prior research. There were 64 participants ranging in age from 18 to 24 who completed 1 of the following activities: drawing, writing, or sitting quietly for 10 min. Positive and negative affects were…

Different patterns of puberty effect in neural oscillation to negative stimuli: sex differences.

PubMed

Yuan, Jiajin; Ju, Enxia; Yang, Jiemin; Chen, Xuhai; Li, Hong

2014-12-01

The present study investigated the impact of puberty on sex differences in neural sensitivity to negative stimuli. Event-related oscillation technique was used. Because girls are more vulnerable to affective disturbances than boys during adolescence, it was hypothesized that puberty exerts different influences on neural sensitivity to negative stimuli in boys and girls. EEGs were recorded for highly negative (HN), mildly negative (MN) and neutral pictures, when boys and girls distinct in pubertal status performed a non-emotional distracting task. No emotion effect and its interaction with sex and puberty were observed in response latencies. However, puberty influenced the gamma-band oscillation effect for negative stimuli differently for boys and girls: Pre-pubertal boys showed a significant emotion effect for HN stimuli, whose size was decreased in pubertal boys. By contrast, there was a significant emotion effect for HN stimuli in pubertal girls but not in pre-pubertal girls. On the other hand, the size of the emotion effect for HN stimuli was similar for pre-pubertal boys and girls; while this effect was significantly more pronounced in pubertal girls compared to pubertal boys. Additionally, the size of the emotion effect in gamma oscillations decreased as a function of pubertal development during both HN and MN stimulation in boys. For girls, the emotion effect in gamma oscillations increased with pubertal development during HN stimulation. Thus, puberty is associated with reduced neural sensitivity in boys but increased sensitivity in girls, in reaction to negative stimuli. The implications of these results for the psychopathology during adolescence were discussed.

Field-induced phase transitions and enhanced double negative electrocaloric effects in (Pb,La)(Zr,Sn,Ti)O3 antiferroelectric single crystal

NASA Astrophysics Data System (ADS)

Zhuo, Fangping; Li, Qiang; Qiao, Huimin; Yan, Qingfeng; Zhang, Yiling; Xi, Xiaoqing; Chu, Xiangcheng; Long, Xifa; Cao, Wenwu

2018-03-01

Field-induced phase transitions and electrocaloric effect have been studied in (Pb,La)(Zr,Sn,Ti)O3 (PLZST) antiferroelectric single crystal. Temperature dependent dielectric, Raman spectra, as well as in situ domain evolution demonstrated that the order of phase transitions during heating is in the sequence of orthorhombic antiferroelectric → tetragonal antiferroelectric → cubic paraelectric. Enhanced negative electrocaloric effect value of -3.6 °C and electrocaloric strength of 0.3 K mm/kV at 125 °C have been achieved. Double negative effects (-0.7 °C at 45 °C and -3.6 °C at 125 °C) and a relatively large positive effect (1 °C) near Curie temperature (190 °C) have been found in the PLZST single crystal. Moreover, microscopic dipoles and a phenomenological Landau-type model were employed to understand these unusual electrocaloric effects. Enhanced negative effect and the coexistence of both negative and positive effects in one material are promising for us to develop practical solid-state cooling devices with high efficiency.

The influence of hormonal and neuronal factors on rat heart adrenoceptors

PubMed Central

Kunos, George; Mucci, Lucia; O'Regan, Seana

1980-01-01

1 The influence of hormonal and neuronal factors on adrenoceptors mediating increased cardiac force and rate of contraction were studied in rat isolated atria. The pharmacological properties of these receptors were deduced from the relative potencies of agonists and from the effects of selective α- and β-adrenoceptor antagonists. The numbers and affinities of α- and β-adrenoceptors were also determined by radioligand binding to ventricular membrane fragments. 2 Hypophysectomy reduced the inotropic potency of isoprenaline and increased the potency of phenylephrine and methoxamine in left atria. The effect of phenylephrine was inhibited by propranolol less effectively and by phentolamine or phenoxybenzamine more effectively in hypophysectomized than in control rats. The difference in block was smaller at low than at high antagonist concentrations. Similar but smaller changes were observed for chronotropic responses of right atria. 3 The decreased β- and increased α-receptor response after hypophysectomy was similar to that observed earlier in thyroidectomized rats (Kunos, 1977). These changes developed slowly after hypophysectomy (>2 weeks), they were both reversed within 2 days of thyroxine treatment (0.2 mg/kg daily), but were not affected by cortisone treatment (50 mg/kg every 12 h for 4 days). 4 Treatment of hypophysectomized rats for 2 days with thyroxine increased the density of [3H]-dihydroalprenolol ([3H]-DHA) binding sites from 27.5 ± 2.7 to 45.5 ± 5.7 fmol/mg protein and decreased the density of [3H]-WB-4101 binding sites from 38.7 ± 3.1 to 18.7 ± 2.5 fmol/mg protein. The affinity of either type of binding site for agonists or antagonist was not significantly altered by thyroxine treatment and the sum total of α1- and β-receptors remained the same. 5 Sympathetic denervation of thyroidectomized rats by 6-hydroxydopamine increased the inotropic potency of isoprenaline and noradrenaline and the blocking effect of propranolol, and decreased the potency of phenylephrine and the blocking effect of phenoxybenzamine to or beyond values observed in euthyroid controls. The density of [3H]-DHA binding sites was higher and that of [3H]-WB-4101 binding sites was lower in the denervated than in the innervated hypothyroid myocardium. Depletion of endogenous noradrenaline stores by reserpine did not significantly alter the adrenoceptor response pattern of the hypothyroid preparations and did not influence the density or affinity of [3H]-DHA and [3H]-WB-4101 binding sites. 6 These results indicate that thyrotropin or steroids do not contribute to the reciprocal changes in the sensitivity of cardiac α1- and β-adrenoceptors in altered thyroid states. These thyroid hormone-dependent changes are probably due to a parallel, reciprocal change in the numbers but not the affinities of α1- and β-adrenoceptors. Reciprocal regulation of cardiac α1- and β-adrenoceptors by thyroid hormones requires intact sympathetic innervation but not the presence of normal stores of the neurotransmitter. PMID:7470752

Positive inotropic and vasodilator actions of milrinone in patients with severe congestive heart failure. Dose-response relationships and comparison to nitroprusside.

PubMed Central

Jaski, B E; Fifer, M A; Wright, R F; Braunwald, E; Colucci, W S

1985-01-01

Milrinone is a potent positive inotropic and vascular smooth muscle-relaxing agent in vitro, and therefore, it is not known to what extent each of these actions contributes to the drug's hemodynamic effects in patients with heart failure. In 11 patients with New York Heart Association class III or IV congestive heart failure, incremental intravenous doses of milrinone were administered to determine the dose-response relationships for heart rate, systemic vascular resistance, and inotropic state, the latter measured by peak positive left ventricular derivative of pressure with respect to time (dP/dt). To clarify further the role of a positive inotropic action, the relative effects of milrinone and nitroprusside on left ventricular stroke work and dP/dt were compared in each patient at doses matched to cause equivalent reductions in mean arterial pressure or systemic vascular resistance, indices of left ventricular afterload. Milrinone caused heart rate, stroke volume, and dP/dt to increase, and systemic vascular resistance to decrease in a concentration-related manner. At the two lowest milrinone doses resulting in serum concentrations of 63 +/- 4 and 156 +/- 5 ng/ml, respectively, milrinone caused significant increases in stroke volume and dP/dt, but no changes in systemic vascular resistance or heart rate. At the maximum milrinone dose administered (mean serum concentration, 427 +/- 11 ng/ml), heart rate increased from 92 +/- 4 to 99 +/- 4 bpm (P less than 0.01), mean aortic pressure fell from 82 +/- 3 to 71 +/- 3 mmHg (P less than 0.01), right atrial pressure fell from 15 +/- 2 to 7 +/- 1 mmHg (P less than 0.005), left ventricular end-diastolic pressure fell from 26 +/- 3 to 18 +/- 3 (P less than 0.005), stroke volume index increased from 20 +/- 2 to 30 +/- 2 ml/m2 (P less than 0.005), stroke work index increased from 14 +/- 2 to 21 +/- 2 g X m/m2 (P less than 0.01), and dP/dt increased from 858 +/- 54 to 1,130 +/- 108 mmHg/s (P less than 0.005). When compared with nitroprusside for a matched reduction in mean aortic pressure or systemic vascular resistance, milrinone caused a significantly greater increase in stroke work index at the same or lower left ventricular end-diastolic pressure. Milrinone caused a concentration-related increase in dP/dt (32% increase at maximum milrinone dose), whereas nitroprusside had no effect. These data in patients with severe heart failure indicate that in addition to a vasodilating effect, milrinone exerts a concentration-related positive inotropic action that contributes significantly to the drug's overall hemodynamic effects. The positive inotropic action occurs at drug levels that do not exert significant chronotropic or vasodilator effects. Images PMID:3973022

Effect of hysteretic and non-hysteretic negative capacitance on tunnel FETs DC performance

NASA Astrophysics Data System (ADS)

Saeidi, Ali; Jazaeri, Farzan; Stolichnov, Igor; Luong, Gia V.; Zhao, Qing-Tai; Mantl, Siegfried; Ionescu, Adrian M.

2018-03-01

This work experimentally demonstrates that the negative capacitance effect can be used to significantly improve the key figures of merit of tunnel field effect transistor (FET) switches. In the proposed approach, a matching condition is fulfilled between a trained-polycrystalline PZT capacitor and the tunnel FET (TFET) gate capacitance fabricated on a strained silicon-nanowire technology. We report a non-hysteretic switch configuration by combining a homojunction TFET and a negative capacitance effect booster, suitable for logic applications, for which the on-current is increased by a factor of 100, the transconductance by 2 orders of magnitude, and the low swing region is extended. The operation of a hysteretic negative capacitance TFET, when the matching condition for the negative capacitance is fulfilled only in a limited region of operation, is also reported and discussed. In this late case, a limited improvement in the device performance is observed. Overall, the paper demonstrates the main beneficial effects of negative capacitance on TFETs are the overdrive and transconductance amplification, which exactly address the most limiting performances of current TFETs.

Mindful attention predicts greater recovery from negative emotions, but not reduced reactivity.

PubMed

Cho, Sinhae; Lee, Hyejeen; Oh, Kyung Ja; Soto, José A

2017-09-01

This study investigated the role of dispositional mindful attention in immediate reactivity to, and subsequent recovery from, laboratory-induced negative emotion. One hundred and fourteen undergraduates viewed blocks of negative pictures followed by neutral pictures. Participants' emotional responses to negative pictures and subsequent neutral pictures were assessed via self-reported ratings. Participants' emotional response to negative pictures was used to index level of emotional reactivity to unpleasant stimuli; emotional response to neutral pictures presented immediately after the negative pictures was used to index level of emotional recovery from pre-induced negative emotion (residual negativity). Results indicated that mindful attention was not associated with the emotional response to negative pictures, but it was associated with reduced negative emotion in response to the neutral pictures presented immediately after the negative pictures, suggesting better recovery as opposed to reduced reactivity. This effect was especially pronounced in later experimental blocks when the accumulation of negative stimuli produced greater negative emotion from which participants had to recover. The current study extends previous findings on the relationship between dispositional mindfulness and reduced negative emotion by demonstrating that mindful attention may facilitate better recovery from negative emotion, possibly through more effective disengagement from previous stimuli.

Prediction of large negative shaded-side spacecraft potentials

NASA Technical Reports Server (NTRS)

Prokopenko, S. M. L.; Laframboise, J. G.

1977-01-01

A calculation by Knott, for the floating potential of a spherically symmetric synchronous-altitude satellite in eclipse, was adapted to provide simple calculations of upper bounds on negative potentials which may be achieved by electrically isolated shaded surfaces on spacecraft in sunlight. Large (approximately 60 percent) increases in predicted negative shaded-side potentials are obtained. To investigate effective potential barrier or angular momentum selection effects due to the presence of less negative sunlit-side or adjacent surface potentials, these expressions were replaced by the ion random current, which is a lower bound for convex surfaces when such effects become very severe. Further large increases in predicted negative potentials were obtained, amounting to a doubling in some cases.

Negative ion treatment increases positive emotional processing in seasonal affective disorder.

PubMed

Harmer, C J; Charles, M; McTavish, S; Favaron, E; Cowen, P J

2012-08-01

Antidepressant drug treatments increase the processing of positive compared to negative affective information early in treatment. Such effects have been hypothesized to play a key role in the development of later therapeutic responses to treatment. However, it is unknown whether these effects are a common mechanism of action for different treatment modalities. High-density negative ion (HDNI) treatment is an environmental manipulation that has efficacy in randomized clinical trials in seasonal affective disorder (SAD). The current study investigated whether a single session of HDNI treatment could reverse negative affective biases seen in seasonal depression using a battery of emotional processing tasks in a double-blind, placebo-controlled randomized study. Under placebo conditions, participants with seasonal mood disturbance showed reduced recognition of happy facial expressions, increased recognition memory for negative personality characteristics and increased vigilance to masked presentation of negative words in a dot-probe task compared to matched healthy controls. Negative ion treatment increased the recognition of positive compared to negative facial expression and improved vigilance to unmasked stimuli across participants with seasonal depression and healthy controls. Negative ion treatment also improved recognition memory for positive information in the SAD group alone. These effects were seen in the absence of changes in subjective state or mood. These results are consistent with the hypothesis that early change in emotional processing may be an important mechanism for treatment action in depression and suggest that these effects are also apparent with negative ion treatment in seasonal depression.

Fast and fragile: A new look at the automaticity of negation processing.

PubMed

Deutsch, Roland; Kordts-Freudinger, Robert; Gawronski, Bertram; Strack, Fritz

2009-01-01

Numerous studies suggest that processing verbal materials containing negations slows down cognition and makes it more error-prone. This suggests that processing negations affords relatively nonautomatic processes. The present research studied the role of two automaticity features (processing speed and resource dependency) for negation processing. In three experiments, we tested the impact of verbal negations on affective priming effects in the Affect Misattribution Paradigm. Going beyond previous work, the results indicate that negations can be processed unintentionally and quickly (Experiments 1 and 2). In Experiment 3, negations failed to qualify affective priming effects when participants' working memory was taxed by memorizing an eight-digit number. In sum, the experiments suggest that negations can be processed unintentionally, very quickly, but that they rely on working-memory resources.

Conspecific Leaf Litter-Mediated Effect of Conspecific Adult Neighborhood on Early-Stage Seedling Survival in A Subtropical Forest

PubMed Central

Liu, Heming; Shen, Guochun; Ma, Zunping; Yang, Qingsong; Xia, Jianyang; Fang, Xiaofeng; Wang, Xihua

2016-01-01

Conspecific adults have strong negative effect on the survival of nearby early-stage seedlings and thus can promote species coexistence by providing space for the regeneration of heterospecifics. The leaf litter fall from the conspecific adults, and it could mediate this conspecific negative adult effect. However, field evidence for such effect of conspecific leaf litter remains absent. In this study, we used generalized linear mixed models to assess the effects of conspecific leaf litter on the early-stage seedling survival of four dominant species (Machilus leptophylla, Litsea elongate, Acer pubinerve and Distylium myricoides) in early-stage seedlings in a subtropical evergreen broad-leaved forest in eastern China. Our results consistently showed that the conspecific leaf litter of three species negatively affected the seedling survival. Meanwhile, the traditional conspecific adult neighborhood indices failed to detect this negative conspecific adult effect. Our study revealed that the accumulation of conspecific leaf litter around adults can largely reduce the survival rate of nearby seedlings. Ignoring it could result in underestimation of the importance of negative density dependence and negative species interactions in the natural forest communities. PMID:27886275

Conspecific Leaf Litter-Mediated Effect of Conspecific Adult Neighborhood on Early-Stage Seedling Survival in A Subtropical Forest.

PubMed

Liu, Heming; Shen, Guochun; Ma, Zunping; Yang, Qingsong; Xia, Jianyang; Fang, Xiaofeng; Wang, Xihua

2016-11-25

Conspecific adults have strong negative effect on the survival of nearby early-stage seedlings and thus can promote species coexistence by providing space for the regeneration of heterospecifics. The leaf litter fall from the conspecific adults, and it could mediate this conspecific negative adult effect. However, field evidence for such effect of conspecific leaf litter remains absent. In this study, we used generalized linear mixed models to assess the effects of conspecific leaf litter on the early-stage seedling survival of four dominant species (Machilus leptophylla, Litsea elongate, Acer pubinerve and Distylium myricoides) in early-stage seedlings in a subtropical evergreen broad-leaved forest in eastern China. Our results consistently showed that the conspecific leaf litter of three species negatively affected the seedling survival. Meanwhile, the traditional conspecific adult neighborhood indices failed to detect this negative conspecific adult effect. Our study revealed that the accumulation of conspecific leaf litter around adults can largely reduce the survival rate of nearby seedlings. Ignoring it could result in underestimation of the importance of negative density dependence and negative species interactions in the natural forest communities.

Neonicotinoid insecticides negatively affect performance measures of non‐target terrestrial arthropods: a meta‐analysis

USGS Publications Warehouse

Main, Anson; Webb, Elisabeth B.; Goyne, Keith W.; Mengel, Doreen C.

2018-01-01

Neonicotinoid insecticides are currently the fastest‐growing and most widely used insecticide class worldwide. Valued for their versatility in application, these insecticides may cause deleterious effects in a range of non‐target (beneficial) arthropods. However, it remains unclear whether strong patterns exist in terms of their major effects, if broad measures of arthropod performance are negatively affected, or whether different functional groups are equally vulnerable. Here, we present a meta‐analysis of 372 observations from 44 field and laboratory studies that describe neonicotinoid effects on 14 arthropod orders across five broad performance measures: abundance, behavior, condition, reproductive success, and survival. Across studies, neonicotinoids negatively affected all performance metrics evaluated; however, magnitude of the effects varied. Arthropod behavior and survival were the most negatively affected and abundance was the least negatively affected. Effects on arthropod functional groups were inconsistent. Pollinator condition, reproductive success, and survival were significantly lower in neonicotinoid treatments compared to untreated controls; whereas, neonicotinoid effects on detritivores were not significant. Although magnitude of arthropod response to neonicotinoids varied among performance measures and functional groups, we documented a consistent negative relationship between exposure to neonicotinoid insecticides in published studies and beneficial arthropod performance.

Effects of age on negative subsequent memory effects associated with the encoding of item and item-context information.

PubMed

Mattson, Julia T; Wang, Tracy H; de Chastelaine, Marianne; Rugg, Michael D

2014-12-01

It has consistently been reported that "negative" subsequent memory effects--lower study activity for later remembered than later forgotten items--are attenuated in older individuals. The present functional magnetic resonance imaging study investigated whether these findings extend to subsequent memory effects associated with successful encoding of item-context information. Older (n = 25) and young (n = 17) subjects were scanned while making 1 of 2 encoding judgments on a series of pictures. Memory was assessed for the study item and, for items judged old, the item's encoding task. Both memory judgments were made using confidence ratings, permitting item and source memory strength to be unconfounded and source confidence to be equated across age groups. Replicating prior findings, negative item effects in regions of the default mode network in young subjects were reversed in older subjects. Negative source effects, however, were invariant with respect to age and, in both age groups, the magnitude of the effects correlated with source memory performance. It is concluded that negative item effects do not reflect processes necessary for the successful encoding of item-context associations in older subjects. Negative source effects, in contrast, appear to reflect the engagement of processes that are equally important for successful episodic encoding in older and younger individuals. © The Author 2013. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

Fidelity Moderates the Association Between Negative Condom Attitudes and Outcome Behavior in an Evidence-Based Sexual Risk Reduction Intervention for Female Sex Workers.

PubMed

Pitpitan, Eileen V; Chavarin, Claudia V; Semple, Shirley J; Mendoza, Doroteo; Rodriguez, Carlos Magis; Staines, Hugo; Aarons, Gregory A; Patterson, Thomas L

2017-06-01

Intervention fidelity and participant-level variables, such as negative attitudes towards condoms, are important variables to consider in the successful implementation of evidence-based HIV prevention interventions. Mujer Segura is an intervention that has been shown to be efficacious at reducing condomless sex for female sex workers (FSWs) in Mexico [1]. We examined main effects of fidelity, negative condom attitudes, and their interaction on the effectiveness of the Mujer Segura intervention at reducing condomless sex at intervention follow-up. Of the FSWs recruited from 13 cities across Mexico, 528 participated in the Mujer Segura intervention. We measured negative condom attitudes at baseline (comprising of beliefs and outcome evaluations) and condomless sex with clients at baseline and 6-month follow-up. Fidelity was measured by a fidelity checklist completed by independent raters; the sum of potentially 43 total elements completed by the counselor constituted fidelity. Complete fidelity was found in only 15.1% (n = 73) of sessions. There was no significant main effect of intervention fidelity on condomless sex with clients at follow-up. There was a significant and positive main effect of negative condom attitudes and a significant two-way interaction. At lower levels of fidelity, negative condom attitudes predicted greater condomless sex acts, whereas at higher levels of fidelity, the effect of condom attitudes became weaker. The results also indicated that the interaction between negative condom attitudes and fidelity were driven primarily by negative condom beliefs, as opposed to negative condom outcome evaluations. Ensuring treatment fidelity in an HIV prevention intervention is particularly important when participants have negative attitudes towards condoms.

Longitudinal multilevel models of the big-fish-little-pond effect on academic self-concept: counterbalancing contrast and reflected-glory effects in Hong Kong schools.

PubMed

Marsh, H W; Kong, C K; Hau, K T

2000-02-01

Longitudinal multilevel path models (7,997 students, 44 high schools, 4 years) evaluated effects of school-average achievement and perceived school status on academic self-concept in Hong Kong, which has a collectivist culture with a highly achievement-segregated high school system. Consistent with a priori predictions based on the big-fish-little-pond effect (BFLPE), higher school-average achievements led to lower academic self-concepts (contrast effect), whereas higher perceived school status had a counterbalancing positive effect on self-concept (reflected-glory, assimilation effect). The negative BFLPE is the net effect of counterbalancing influences, stronger negative contrast effects, and weaker positive assimilation effects so that controlling perceived school status led to purer--and even more negative--contrast effects. Attending a school where school-average achievement is high simultaneously resulted in a more demanding basis of comparison for one's own accomplishments (the stronger negative contrast effect) and a source of pride (the weaker positive assimilation effect).

Self-control and parental control mediate the relationship between negative emotions and emotional eating among adolescents.

PubMed

Zhu, Hong; Luo, Xingwei; Cai, Taisheng; Li, Zhihua; Liu, Wenli

2014-11-01

The study was conducted to simultaneously investigate the mediating effects of parental control and adolescents' self-control on the relationship between adolescents' negative emotions and emotional eating, and to determine pathways with the greatest effect among these variables. Negative emotions, emotional eating, parental control, and self-control were investigated in 594 high school students (average age=16.70, SD=1.09) in Changsha City, China. High levels of negative emotions and parental control and low levels of self-control were strongly related to high levels of emotional eating in adolescents. In addition to the direct relationship between negative emotions and emotional eating, there was a mediating effect observed through low self-control and high parental control. The mediational effect of parental control was non-significant in adolescent boys. Furthermore, negative emotions related to emotional eating through the effect of parental control on adolescents' self-control. The degree to which both mediators explained the relationship between negative emotions and emotional eating ranged from 52.6% to 66.8%, and self-control had a stronger mediational effect than did parental control. The results indicate that both self-control and parental control should be considered in designing preventative measures against emotional eating in adolescents. Adolescent self-control training could also assist in preventing emotional eating. Copyright © 2014 Elsevier Ltd. All rights reserved.

Suppressor Effects of Positive and Negative Religious Coping on Academic Burnout Among Korean Middle School Students.

PubMed

Noh, Hyunkyung; Chang, Eunbi; Jang, Yoojin; Lee, Ji Hae; Lee, Sang Min

2016-02-01

Statistical suppressor effects in prediction models can provide evidence of the interdependent relationship of independent variables. In this study, the suppressor effects of positive and negative religious coping on academic burnout were examined using longitudinal data. First, 388 middle school students reported their type of religion and use of positive and negative religious coping strategies. Four months later, they also reported their level of academic burnout. From structural equation modeling, significant suppressor effects were found among religious students. That is, the coefficients became larger when both positive and negative religious coping predicted academic burnout simultaneously, compared to when each religious coping predicted academic burnout alone. However, suppressor effects were not found among non-religious students.

The influence of presentation format on the "bigger is better" (BIB) effect.

PubMed

Bromgard, Gregg D; Trafimow, David; Silvera, David H

2013-04-01

Two experiments tested the "bigger is better" (BIB) effect, whereby bigger objects are perceived more favorably than smaller ones. In Experiment 1, participants directly compared pairs of objects and a strong BIB effect was obtained for both positively and negatively valenced stimuli. In Experiment 2, comparative and absolute evaluations were combined in a single experiment and the BIB effect was mediated for positively and negatively valenced stimuli. Taken in combination, the data support a complex hypothesis that pair-wise presentations induce a comparative process that causes a BIB effect. But when objects are evaluated separately, size and valence interact such that increased size evokes more positive ratings of positive objects and more negative ratings for negative objects.

Giant Negative Electrocaloric Effect in (Pb,La)(Zr,Sn,Ti)O3 Antiferroelectrics Near Room Temperature.

PubMed

Zhuo, Fangping; Li, Qiang; Gao, Jinghan; Ji, Yongjie; Yan, Qingfeng; Zhang, Yiling; Wu, Hong-Hui; Xi, Xiao-Qing; Chu, Xiangcheng; Cao, Wenwu

2018-04-11

(Pb 0.97 La 0.02 )(Zr x Sn 0.94- x Ti 0.06 )O 3 (PLZST) antiferroelectric ceramics with x = 0.75-0.90 have been fabricated and found to be a novel electrocaloric material system with a giant negative electrocaloric effect (Δ T = -11.5 K) and a large electrocaloric strength (|Δ T/Δ E| = 0.105 K cm kV -1 ) near room temperature. Additionally, the PLZST antiferroelectric ceramic also exhibits a large positive electrocaloric effect around the Curie temperature. The giant negative effect and the coexistence of both positive and negative electrocaloric effects in one material indicate a promising possibility to develop mid- to large-scale solid-state cooling devices with high efficiency.

Plant-soil feedback in East-African savanna trees.

PubMed

Rutten, Gemma; Prati, Daniel; Hemp, Andreas; Fischer, Markus

2016-02-01

Research in savannas has focused on tree-grass interactions, whereas tree species coexistence received little attention. A leading hypothesis to explain tree coexistence is the Janzen-Connell model, which proposes an accumulation of host-specific enemies, e.g., soil organisms. While it has been shown in several non-savanna case studies that seedlings dispersed away from the mother perform better than seedlings that stay close (home-away effect), few studies tested whether foreign seedling species can replace own seedlings under conspecific adults (replacement effect). Some studies additionally tested for negative effects of conspecific biota (conspecific effect) to demonstrate the accumulation of enemies. We tested these effects by reciprocally growing seedlings of four tree species on soil collected beneath adults of all species, with and without applying a soil sterilization treatment. We found negative home-away effects suggesting that dispersal is advantageous and negative replacement effects suggesting species replacement under adults. While negative conspecific effects indicate accumulated enemies, positive heterospecific effects indicate an accumulation of mutualists rather than enemies for some species. We suggest that plant-soil feedbacks may well contribute to tree coexistence in savannas due to both negative conspecific and positive heterospecific feedbacks.

Positive fantasies or negative contrasts: the effect of media body ideals on restrained eaters' mood, weight satisfaction, and food intake.

PubMed

Boyce, Jessica A; Kuijer, Roeline G; Gleaves, David H

2013-09-01

Although viewing media body ideals promotes body dissatisfaction and problematic eating among women (e.g., extreme restraint/overeating), some argue that women only report such negative effects because they think that they are meant to (i.e., demand characteristics). Because restrained eaters are trying to lose weight, they might be vulnerable to such media exposure. However, because of demand characteristics, evidence is mixed. Therefore, we minimized demand characteristics and explored whether media body ideals would trigger restrained eaters to report negative (negative mood, weight dissatisfaction) or positive (positive mood, weight satisfaction) effects. We also hypothesized that this change (negative or positive) would encourage food intake. Restrained and unrestrained eaters (n=107) memorized media or control images. Restrained eaters exposed to media images reported decreased weight satisfaction and increased negative mood, but their food intake was not significantly affected. Perhaps paying advertent attention to the images caused goal-related negative affect, which triggered restraint. Copyright © 2013 Elsevier Ltd. All rights reserved.

The consequences of perceived discrimination for psychological well-being: a meta-analytic review.

PubMed

Schmitt, Michael T; Branscombe, Nyla R; Postmes, Tom; Garcia, Amber

2014-07-01

In 2 meta-analyses, we examined the relationship between perceived discrimination and psychological well-being and tested a number of moderators of that relationship. In Meta-Analysis 1 (328 independent effect sizes, N = 144,246), we examined correlational data measuring both perceived discrimination and psychological well-being (e.g., self-esteem, depression, anxiety, psychological distress, life satisfaction). Using a random-effects model, the mean weighted effect size was significantly negative, indicating harm (r = -.23). Effect sizes were larger for disadvantaged groups (r = -.24) compared to advantaged groups (r = -.10), larger for children compared to adults, larger for perceptions of personal discrimination compared to group discrimination, and weaker for racism and sexism compared to other stigmas. The negative relationship was significant across different operationalizations of well-being but was somewhat weaker for positive outcomes (e.g., self-esteem, positive affect) than for negative outcomes (e.g., depression, anxiety, negative affect). Importantly, the effect size was significantly negative even in longitudinal studies that controlled for prior levels of well-being (r = -.15). In Meta-Analysis 2 (54 independent effect sizes, N = 2,640), we examined experimental data from studies manipulating perceptions of discrimination and measuring well-being. We found that the effect of discrimination on well-being was significantly negative for studies that manipulated general perceptions of discrimination (d = -.25), but effects did not differ from 0 when attributions to discrimination for a specific negative event were compared to personal attributions (d = .06). Overall, results support the idea that the pervasiveness of perceived discrimination is fundamental to its harmful effects on psychological well-being. PsycINFO Database Record (c) 2014 APA, all rights reserved.

Klinefelter syndrome, cardiovascular system, and thromboembolic disease: review of literature and clinical perspectives.

PubMed

Salzano, Andrea; Arcopinto, Michele; Marra, Alberto M; Bobbio, Emanuele; Esposito, Daniela; Accardo, Giacomo; Giallauria, Francesco; Bossone, Eduardo; Vigorito, Carlo; Lenzi, Andrea; Pasquali, Daniela; Isidori, Andrea M; Cittadini, Antonio

2016-07-01

Klinefelter syndrome (KS) is the most frequently occurring sex chromosomal aberration in males, with an incidence of about 1 in 500-700 newborns. Data acquired from large registry-based studies revealed an increase in mortality rates among KS patients when compared with mortality rates among the general population. Among all causes of death, metabolic, cardiovascular, and hemostatic complication seem to play a pivotal role. KS is associated, as are other chromosomal pathologies and genetic diseases, with cardiac congenital anomalies that contribute to the increase in mortality. The aim of the current study was to systematically review the relationships between KS and the cardiovascular system and hemostatic balance. In summary, patients with KS display an increased cardiovascular risk profile, characterized by increased prevalence of metabolic abnormalities including Diabetes mellitus (DM), dyslipidemia, and alterations in biomarkers of cardiovascular disease. KS does not, however, appear to be associated with arterial hypertension. Moreover, KS patients are characterized by subclinical abnormalities in left ventricular (LV) systolic and diastolic function and endothelial function, which, when associated with chronotropic incompetence may led to reduced cardiopulmonary performance. KS patients appear to be at a higher risk for cardiovascular disease, attributing to an increased risk of thromboembolic events with a high prevalence of recurrent venous ulcers, venous insufficiency, recurrent venous and arterial thromboembolism with higher risk of deep venous thrombosis or pulmonary embolism. It appears that cardiovascular involvement in KS is mainly due to chromosomal abnormalities rather than solely on low serum testosterone levels. On the basis of evidence acquisition and authors' own experience, a flowchart addressing the management of cardiovascular function and prognosis of KS patients has been developed for clinical use. © 2016 European Society of Endocrinology.

Comparison of aortic and carotid baroreflex stimulus-response characteristics in humans

NASA Technical Reports Server (NTRS)

Smith, S. A.; Querry, R. G.; Fadel, P. J.; Weiss, M. W.; Olivencia-Yurvati, A.; Shi, X.; Raven, P. B.

2001-01-01

In order to characterize the stimulus-response relationships of the arterial, aortic, and carotid baroreflexes in mediating cardiac chronotropic function, we measured heart rate (HR) responses elicited by acute changes in mean arterial pressure (MAP) and carotid sinus pressure (CSP) in 11 healthy individuals. Arterial (aortic + carotid) baroreflex control of HR was quantified using ramped changes in MAP induced by bolus injection of phenylephrine (PE) and sodium nitroprusside (SN). To assess aortic-cardiac responses, neck pressure (NP) and suction (NS) were applied during PE and SN administration, respectively, to counter alterations in CSP thereby isolating the aortic baroreflex. Graded levels of NP and NS were delivered to the carotid sinus using a customized neck collar device to assess the carotid-cardiac baroreflex, independent of drug infusion. The operating characteristics of each reflex were determined from the logistic function of the elicited HR response to the induced change in MAP. The arterial pressures at which the threshold was located on the stimulus-response curves determined for the arterial, aortic and carotid baroreflexes were not significantly different (72+/-4, 67+/-3, and 72+/-4 mm Hg, respectively, P > 0.05). Similarly, the MAP at which the saturation of the reflex responses were elicited did not differ among the baroreflex arcs examined (98+/-3, 99+/-2, and 102+/-3 mm Hg, respectively). These data suggest that the baroreceptor populations studied operate over the same range of arterial pressures. This finding indicates each baroreflex functions as both an important anti-hypotensive and anti-hypertensive mechanism. In addition, this investigation describes a model of aortic baroreflex function in normal healthy humans, which may prove useful in identifying the origin of baroreflex dysfunction in disease- and training-induced conditions.

Hypertension in response to autoantibodies to the angiotensin II type I receptor (AT1-AA) in pregnant rats: role of endothelin-1.

PubMed

LaMarca, Babbette; Parrish, Marc; Ray, Lillian Fournier; Murphy, Sydney R; Roberts, Lyndsay; Glover, Porter; Wallukat, Gerd; Wenzel, Katrin; Cockrell, Kathy; Martin, James N; Ryan, Michael J; Dechend, Ralf

2009-10-01

Agonistic autoantibodies to the angiotensin II type I receptor (AT1-AA) and endothelin -1 (ET-1) are suggested to be important links between placental ischemia and hypertension during preeclampsia. Activation of the angiotensin II type 1 receptor (AT1R) increases endothelial cell production of ET-1; however, the importance of ET-1 in response to AT1-AA-mediated AT1 R activation during preeclampsia is unknown. Furthermore, the role of AT1-AA-mediated increases in blood pressure during pregnancy remains unclear. The objective of this study was to test the hypothesis that AT1-AA, increased to levels observed in preeclamptic women and placental ischemic rats, increases mean arterial pressure (MAP) by activation of the ET-1 system. Chronic infusion of purified rat AT1-AA into normal pregnant (NP) rats for 7 days increased AT1-AA from 0.68+/-0.5 to 10.88+/-1.1 chronotropic units (P<0.001). The increased AT1-AA increased MAP from 99+/-1 to 119+/-2 mm Hg (P<0.001). The hypertension was associated with significant increases in renal cortices (11-fold) and placental (4-fold) ET-1. To determine whether ET-1 mediates AT1-AA-induced hypertension, pregnant rats infused with AT1-AA and NP rats were treated with an ET(A) receptor antagonist. MAP was 100+/-1 mm Hg in AT1-AA+ET(A) antagonist-treated rats versus 98+/-2 mm Hg in ET(A) antagonist-treated rats. Collectively, these data support the hypothesis that one potential pathway whereby AT1-AAs increase blood pressure during pregnancy is by an ET-1-dependent mechanism.

Interaction of semicircular canal stimulation with carotid baroreceptor reflex control of heart rate

NASA Technical Reports Server (NTRS)

Convertino, V. A.

1998-01-01

The carotid-cardiac baroreflex contributes to the prediction of orthostatic tolerance; experimental attenuation of the reflex response leads to orthostatic hypotension in humans and animals. Anecdotal observations indicate that rotational head movements about the vertical axis of the body can also induce orthostatic bradycardia and hypotension through increased parasympathetic activity. We therefore measured the chronotropic response to carotid baroreceptor stimulation in 12 men during varying conditions of vestibulo-oculomotor stimulation to test the hypothesis that stimulation of the semicircular canals associated with head movements in the yaw plane inhibits cardioacceleration through a vagally mediated baroreflex. Carotid-cardiac baroreflex response was assessed by plotting R-R intervals (ms) at each of 8 neck pressure steps with their respective carotid distending pressures (mmHg). Calculated baroreflex gain (maximal slope of the stimulus-response relationship) was measured under 4 experimental conditions: 1) sinusoidal whole-body yaw rotation of the subject in the dark without visual fixation (combined vestibular-oculomotor stimulation); 2) yaw oscillation of the subject while tracking a small head-fixed light moving with the subject (vestibular stimulation without eye movements); 3) subject stationary while fixating on a small light oscillating in yaw at the same frequency, peak acceleration, and velocity as the chair (eye movements without vestibular stimulation); and 4) subject stationary in the dark (no eye or head motion). Head motion alone and with eye movement reduced baseline baroreflex responsiveness to the same stimulus by 30%. Inhibition of cardioacceleration during rotational head movements may have significant impact on functional performance in aerospace environments, particularly in high-performance aircraft pilots during high angular acceleration in aerial combat maneuvers or in astronauts upon return from spaceflight who already have attenuated baroreflex functions.

New aspects in electrostimulation of the heart.

PubMed

Schaldach, M

1995-01-01

The interaction of the autonomic nervous system (ANS) and the heart is characterized by a new interdisciplinary field known as neurocardiology which presents the newest strategy for electro-cardiostimulation. In this context, the reestablishment of chronotropy with physiological, closed-loop pacing, as well as the prevention and treatment of a malignant arrhythmia by ANS modulation, is of the highest priority. The main objective toward this goal consists of appropriate monitoring of the autonomic balance and stimulation, respectively, so that neuromodulation of the cardiac efferents can be established. The electrode, as a sensor and an actuator, with its interface on the cellular level becomes of essential importance. The electrode-myocardium interface is determined by the structure of the Helmholtz double layer with regard to its physical, electrochemical, and physiological behavior. The transportation of electrons across the boundary, as well as the electro-chemical reactions determining the biocompatibility of the interface, can be improved by the microstructure of the solid component by creating a fractal surface coating with titanium-nitride or iridium. Experimental and clinical results have demonstrated that the fractal structure ensures negligible polarization as well as improved detection performance, thus, detecting the evoked response of the myocardial cells makes it possible to monitor the neural response of the myocardium as a consequence of a superimposed chronotropic disturbance. The stimulation electrode also monitors the sympathetic activity extracted from intracardiac impedance measurements, thereby providing a new principle of rate adaptation in which the pacemaker is an integral part of the ANS, reestablishing normal chronotropy. Further advantages of the improved electrode interface performance open new aspects in the treatment and prevention of tachyarrhythmia, and in the follow-up of transplanted hearts for the prevention of the rejection processes.

High intensity interval training (HIIT) improves resting blood pressure, metabolic (MET) capacity and heart rate reserve without compromising cardiac function in sedentary aging men.

PubMed

Grace, Fergal; Herbert, Peter; Elliott, Adrian D; Richards, Jo; Beaumont, Alexander; Sculthorpe, Nicholas F

2017-05-13

This study examined a programme of pre-conditioning exercise with subsequent high intensity interval training (HIIT) on blood pressure, echocardiography, cardiac strain mechanics and maximal metabolic (MET) capacity in sedentary (SED) aging men compared with age matched masters athletes (LEX). Using a STROBE compliant observational design, 39 aging male participants (SED; n=22, aged 62.7±5.2yrs) (LEX; n=17, aged=61.1±5.4yrs) were recruited to a study that necessitated three distinct assessment phases; enrolment (Phase A), following pre-conditioning exercise in SED (Phase B), then following 6weeks of HIIT performed once every five days by both groups before reassessment (Phase C). Hemodynamic, echocardiographic and cardiac strain mechanics were obtained at rest and maximal cardiorespiratory and chronotropic responses were obtained at each measurement phase. The training intervention improved systolic, mean arterial blood pressure, rate pressure product and heart rate reserve (each P<0.05) in SED and increased MET capacity in both SED and LEX (P<0.01) which was amplified by HIIT. Echocardiography and cardiac strain measures were unremarkable apart from trivial increase to intra-ventricular septum diastole (IVSd) (P<0.05) and decrease to left ventricular internal dimension diastole (LVId) (P<0.05) in LEX following HIIT. A programme of preconditioning exercise with HIIT induces clinically relevant improvements in blood pressure, rate pressure product and encourages recovery of heart rate reserve in SED, while improving maximal MET capacity in both SED and LEX without inducing any pathological cardiovascular remodeling. These data add to the emerging repute of HIIT as a safe and promising exercise prescription to improve cardiovascular function and metabolic capacity in sedentary aging. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

Negative Priming in Free Recall Reconsidered

PubMed Central

2015-01-01

Negative priming in free recall is the finding of impaired memory performance when previously ignored auditory distracters become targets of encoding and retrieval. This negative priming has been attributed to an aftereffect of deploying inhibitory mechanisms that serve to suppress auditory distraction and minimize interference with learning and retrieval of task-relevant information. In 6 experiments, we tested the inhibitory account of the effect of negative priming in free recall against alternative accounts. We found that ignoring auditory distracters is neither sufficient nor necessary to produce the effect of negative priming in free recall. Instead, the effect is more readily accounted for by a buildup of proactive interference occurring whenever 2 successively presented lists of words are drawn from the same semantic category. PMID:26595066

The power of positive and negative expectations to influence reported symptoms and mood during exposure to wind farm sound.

PubMed

Crichton, Fiona; Dodd, George; Schmid, Gian; Gamble, Greg; Cundy, Tim; Petrie, Keith J

2014-12-01

Wind farm developments have been hampered by claims that sound from wind turbines causes symptoms and negative health reports in nearby residents. As scientific reviews have failed to identify a plausible link between wind turbine sound and health effects, psychological expectations have been proposed as an explanation for health complaints. Building on recent work showing negative expectations can create symptoms from wind turbines, we investigated whether positive expectations can produce the opposite effect, in terms of a reduction in symptoms and improvements in reported health. 60 participants were randomized to either positive or negative expectation groups and subsequently exposed to audible wind farm sound and infrasound. Prior to exposure, negative expectation participants watched a DVD incorporating TV footage about health effects said to be caused by infrasound produced by wind turbines. In contrast, positive expectation participants viewed a DVD that outlined the possible therapeutic effects of infrasound exposure. During exposure to audible windfarm sound and infrasound, symptoms and mood were strongly influenced by the type of expectations. Negative expectation participants experienced a significant increase in symptoms and a significant deterioration in mood, while positive expectation participants reported a significant decrease in symptoms and a significant improvement in mood. The study demonstrates that expectations can influence symptom and mood reports in both positive and negative directions. The results suggest that if expectations about infrasound are framed in more neutral or benign ways, then it is likely reports of symptoms or negative effects could be nullified.

Differential Effects of Positive versus Negative Self-Involving Counselor Responses.

ERIC Educational Resources Information Center

Remer, Pam; And Others

1983-01-01

Investigated the effects of positive and negative counselor disclosure using typescripts of hypothetical counseling interviews. Results indicated impact of condition was mixed, with each having some desirable effects. (PAS)

Ironic effects of emotion suppression when recounting distressing memories.

PubMed

Dalgleish, Tim; Yiend, Jenny; Schweizer, Susanne; Dunn, Barnaby D

2009-10-01

Theories of ironic mental control posit that under conditions in which effortful control is compromised, for example, in laboratory manipulations of mental load or in those suffering from clinical levels of negative affect, attempts to suppress negative emotions can lead to a paradoxical increase in such feelings, relative to conditions in which no suppression is attempted. In line with this, we showed that high negative affect participants, when asked to suppress (downregulate) their negative feelings while writing about a distressing personal memory, exhibited an ironically greater increase in negative emotions compared with a no-instruction condition, in contrast to low negative affect controls who were able to suppress their emotions. Comparable ironic effects were not associated with instructions to experience emotions. This first demonstration of ironic effects of emotion suppression in response to personal material in those with emotional problems sheds light into how certain emotion regulation strategies may maintain and exacerbate such conditions.

Child Temperament Moderates Effects of Parent-Child Mutuality on Self-Regulation: A Relationship-Based Path for Emotionally Negative Infants

PubMed Central

Kim, Sanghag; Kochanska, Grazyna

2012-01-01

This study examined infants’ negative emotionality as moderating the effect of parent-child Mutually Responsive Orientation (MRO) on children’s self-regulation (N=102). Negative emotionality was observed in anger-eliciting episodes and in interactions with parents at 7 months. MRO was coded in naturalistic interactions at 15 months. Self-regulation was measured at 25 months in effortful control battery and as self-regulated compliance to parental requests and prohibitions. Negative emotionality moderated the effects of mother-child MRO. Highly negative infants were less self-regulated when they were in unresponsive relationships (low MRO), but more self-regulated when in responsive relationships (high MRO). For infants not prone to negative emotionality, there was no link between MRO and self-regulation. The “regions-of-significance” analysis supported the differential susceptibility model not the diathesis-stress model. PMID:22670684

Specific and non-specific match effects in negative priming.

PubMed

Labossière, Danielle I; Leboe-McGowan, Jason P

2018-01-01

The negative priming effect occurs when withholding a response to a stimulus impairs generation of subsequent responding to a same or a related stimulus. Our goal was to use the negative priming procedure to obtain insights about the memory representations generated by ignoring vs. attending/responding to a prime stimulus. Across three experiments we observed that ignoring a prime stimulus tends to generate higher identity-independent, non-specific repetition effects, owing to an overlap in the coarse perceptual form of a prime distractor and a probe target. By contrast, attended repetition effects generate predominantly identity-specific sources of facilitation. We use these findings to advocate for using laboratory phenomena to illustrate general principles that can be of practical use to non-specialists. In the case of the negative priming procedure, we propose that the procedure provides a useful means for investigating attention/memory interactions, even if the specific cause (or causes) of negative priming effects remain unresolved. Copyright © 2017 Elsevier B.V. All rights reserved.

The Role of Negative Affect and Self-Concept Clarity in Predicting Self-Injurious Urges in Borderline Personality Disorder Using Ecological Momentary Assessment.

PubMed

Scala, J Wesley; Levy, Kenneth N; Johnson, Benjamin N; Kivity, Yogev; Ellison, William D; Pincus, Aaron L; Wilson, Stephen J; Newman, Michelle G

2018-01-01

Deficits in identity as well as negative affect have been shown to predict self-injurious and suicidal behaviors in individuals with borderline personality disorder (BPD). However, less is known about the interactive effects of these two predictors. We examined the moderating effect of a particular component of identity, self-concept, on the relationship between negative affect and self-injurious urges utilizing ecological momentary assessments. Outpatients diagnosed with either BPD (n = 36) or any anxiety disorder but no BPD (n = 18) completed surveys throughout the day over a 21-day period. Higher levels of momentary negative affect predicted greater subsequent urges to self-injure, but only when self-concept clarity was low (z = -3.60, p < .01). This effect did not differ between diagnostic groups. The results suggest that self-concept clarity has a protective effect against self-injurious urges in light of high negative affect, and that this effect may be transdiagnostic.

The polarizing effect of arousal on negotiation.

PubMed

Brown, Ashley D; Curhan, Jared R

2013-10-01

In this research, we examined the impact of physiological arousal on negotiation outcomes. Conventional wisdom and the prescriptive literature suggest that arousal should be minimized given its negative effect on negotiations, whereas prior research on misattribution of arousal suggests that arousal might polarize outcomes, either negatively or positively. In two experiments, we manipulated arousal and measured its effect on subjective and objective negotiation outcomes. Our results support the polarization effect. When participants had negative prior attitudes toward negotiation, arousal had a detrimental effect on outcomes, whereas when participants had positive prior attitudes toward negotiation, arousal had a beneficial effect on outcomes. These effects occurred because of the construal of arousal as negative or positive affect, respectively. Our findings have important implications not only for negotiation, but also for research on misattribution of arousal, which previously has focused on the target of evaluation, in contrast to the current research, which focused on the critical role of the perceiver.

Participation in HIV Behavioral Research: Unanticipated Benefits and Burdens.

PubMed

Tross, Susan; Pinho, Veronica; Lima, Jennifer E; Ghiroli, Megan; Elkington, Katherine S; Strauss, David H; Wainberg, Milton L

2018-04-30

HIV behavioral research has provided an invaluable knowledge base for effective approaches to behavioral challenges along the HIV care cascade. Little attention has been paid to tracking unanticipated effects of research participation, whether negative or positive. We used qualitative methods to elicit impressions of unanticipated effects of participation in behavioral research. An instrument was developed and piloted to assess positive (emotional gains, practical gains, HIV prevention knowledge and skills gains) and negative (emotional stress, discomfort with research) unanticipated effects. Participants (N = 25) from five projects, including men who have sex with men, adults who use substances, and youth, reported multiple positive unanticipated effects (sexual and drug risk reduction, goal setting, improvements in self-esteem and mood, relationship gains, health care behavior gains, knowledge and introspection gains) and rare unanticipated negative effects. Developing a systematic tool of unanticipated positive and negative effects of participation in behavioral research is a crucial next step.

Effects of Process and Outcome Accountability on Idea Generation.

PubMed

Häusser, Jan Alexander; Frisch, Johanna Ute; Wanzel, Stella; Schulz-Hardt, Stefan

2017-07-01

Previous research on the effects of outcome and process accountability on decision making has neglected the preceding phase of idea generation. We conducted a 2 (outcome accountability: yes vs. no) × 2 (process accountability: yes vs. no) experiment (N = 147) to test the effects of accountability on quantity and quality of generated ideas in a product design task. Furthermore, we examined potential negative side effects of accountability (i.e., stress and lengthened decision making). We found that (a) outcome accountability had a negative effect on quantity of ideas and (b) process accountability extended the idea generation process. Furthermore, any type of accountability (c) had a negative effect on uniqueness of ideas, (d) did not affect the quality of the idea that was selected, and (e) increased stress. Moreover, the negative effect of accountability on uniqueness of ideas was mediated by stress.

Does Negative Interaction in the Church Increase Psychological Distress? Longitudinal Findings from the Presbyterian Panel Survey*

PubMed Central

Ellison, Christopher G.; Zhang, Wei; Krause, Neal; Marcum, John P.

2009-01-01

This study examines the effects of negative interaction in church on psychological distress. After outlining a series of theoretical arguments linking negative interaction with health and well-being, relevant hypotheses are tested using longitudinal data from two surveys of the 1997–1999 Presbyterian Panel, a nationwide panel of members and elders (lay leaders) in congregations of the Presbyterian Church (USA). Findings confirm that negative interaction appears to foster or exacerbate distress over the study period. In addition, specific dimensions of social negativity have distinctive effects; the impact of criticisms on distress surface only in cross-sectional models, while the effects of excessive demands emerge only in the longitudinal models. No subgroup variations in these effects are detected. Implications of these findings are discussed with regard to (a) research on religion and health and (b) congregational life, and a number of promising directions for future research are elaborated. PMID:20694051

The implicit influence of a negative mood on the subliminal mere exposure effect.

PubMed

Kawakami, Naoaki

2012-12-01

Despite numerous studies on the mere exposure effect, it is still not clear why it occurs. The present study examined whether a negative mood would enhance or inhibit the effects. Fifty-two participants (30 men, 22 women; M age = 20.5 yr.) were assigned to one of two mood-induction groups (negative and neutral), and were exposed to a photograph 20 times after the mood induction. Thereafter, a single-category Implicit Association Test was conducted to measure their implicit attitudes toward the photograph. There was a significant interaction, with exposed stimuli evaluated more favorably than unexposed stimuli in the neutral condition, but not in the negative condition. This result suggests that a negative mood inhibited the mere exposure effect, implying that people could use their emotional states as cues to evaluate ambiguous objects that they have been repeatedly exposed to.

Testing the Interactive Effect of Parent and Child ADHD on Parenting in Mothers and Fathers: A Further Test of the Similarity-Fit Hypothesis

ERIC Educational Resources Information Center

Psychogiou, Lamprini; Daley, Dave; Thompson, Margaret; Sonuga-Barke, Edmund

2007-01-01

Mother and child ADHD symptoms both have a negative effect on parenting. Little is known about how these characteristics interact. In a recent paper, we reported two studies that suggested that maternal ADHD ameliorated the negative effects of child ADHD on negative parenting supporting a "similarity-fit" hypothesis. The aim of the current paper…

Electronic Cigarette Expectancies in Smokers with Psychological Distress.

PubMed

Miller, Mollie E; Tidey, Jennifer W; Rohsenow, Damaris J; Higgins, Stephen T

2017-01-01

Very few studies have evaluated perceptions of electronic nicotine delivery systems (ENDS) among smokers with mental illness. This study assessed expectancies about the effects of smoking combustible cigarettes or using ENDS among current smokers with and without severe psychological distress (SPD). We used a crowdsourcing system to survey 268 smokers on their expectancies for the effects of combustible cigarettes and ENDS. Positive expectancies assessed included negative affect reduction, stimulation, positive social effects and weight control, and negative expectancies included negative physical effects, negative psychosocial effects and future health concerns. Smokers with SPD had higher positive expectancies for weight control and social effects of both products compared to those without such distress, and higher expectancies for stimulation from combustible cigarettes compared to ENDS. All participants had significantly lower negative expectancies for ENDS compared to combustible cigarettes, with no significant differences between the groups. Smokers with SPD may be more vulnerable toward ENDS use, as they are for combustible cigarette use, due to greater positive expectancies of the products. Challenging positive expectancies may increase the efficacy of tobacco control efforts in this vulnerable population.

Electronic Cigarette Expectancies in Smokers with Psychological Distress

PubMed Central

Miller, Mollie E.; Tidey, Jennifer W.; Rohsenow, Damaris J.; Higgins, Stephen T.

2017-01-01

Objectives Very few studies have evaluated perceptions of electronic nicotine delivery systems (ENDS) among smokers with mental illness. This study assessed expectancies about the effects of smoking combustible cigarettes or using ENDS among current smokers with and without severe psychological distress (SPD). Methods We used a crowdsourcing system to survey 268 smokers on their expectancies for the effects of combustible cigarettes and ENDS. Positive expectancies assessed included negative affect reduction, stimulation, positive social effects and weight control, and negative expectancies included negative physical effects, negative psychosocial effects and future health concerns. Results Smokers with SPD had higher positive expectancies for weight control and social effects of both products compared to those without such distress, and higher expectancies for stimulation from combustible cigarettes compared to ENDS. All participants had significantly lower negative expectancies for ENDS compared to combustible cigarettes, with no significant differences between the groups. Conclusions Smokers with SPD may be more vulnerable toward ENDS use, as they are for combustible cigarette use, due to greater positive expectancies of the products. Challenging positive expectancies may increase the efficacy of tobacco control efforts in this vulnerable population. PMID:28653023

Practicing psychotherapists are more skilled at downregulating negative emotions than other professionals.

PubMed

Pletzer, Jan Luca; Sanchez, Xavier; Scheibe, Susanne

2015-09-01

Laypeople and psychotherapists alike tend to assume that psychotherapists are more effective than the average population in regulating negative emotions. Being receptive to patients' distress and being able to downregulate negative emotions are important skills for psychotherapists to provide effective help and sustain their own well-being. We investigated whether psychotherapists react to negative material differently and downregulate emotions more effectively than individuals working in other, nontherapeutic, professions. Practicing psychotherapists (n = 21) and a control group of nontherapists (n = 18) were exposed to pictures designed to elicit negative emotions in varying intensities and were asked to rate their emotional response, first after viewing them naturally and then after choosing and applying one of two given regulation strategies (i.e., distraction and reappraisal). Both groups responded similarly in terms of emotional reactivity and strategy choices, but psychotherapists were more effective than nontherapists in reducing their emotional response after applying emotion regulation strategies. We suggest that psychotherapists' comparable emotional reactivity and more effective emotion regulation make them well prepared to provide effective help to patients and safeguard their own well-being. (c) 2015 APA, all rights reserved).

Mutual Influence of Reward Anticipation and Emotion on Brain Activity during Memory Retrieval

PubMed Central

Yan, Chunping; Liu, Fang; Li, Yunyun; Zhang, Qin; Cui, Lixia

2017-01-01

Previous studies on the joint effect of reward motivation and emotion on memory retrieval have obtained inconsistent results. Furthermore, whether and how any such joint effect might vary over time remains unclear too. Accordingly, using the event-related potential (ERP) measurement of high temporal resolution, our study investigates the cognitive and brain mechanisms of monetary reward and emotion affecting the retrieval processes of episodic memory. Twenty undergraduate and graduate students participated in the research, and our study’s behavioral results indicated that reward (relative to no reward) and negative emotion (relative to positive and neutral emotion) significantly improved recognition performance. The ERP results showed that there were significant interactions between monetary reward and emotion on memory retrieval, and the reward effects of positive, neutral, and negative memory occurred at varied intervals in mean amplitude. The reward effect of positive memory appeared relatively early, at 260–330 ms after the stimulus onset in the frontal-frontocentral area, at 260–500 ms in the centroparietal-parietal area and at 500–700 ms in the frontocentral area. However, the reward effects of neutral and negative memory occurred relatively later, and that of negative memory appeared at 500–700 ms in the frontocentral and centroparietal area and that of neutral memory was at 500–700 ms in the frontocentral and centroparietal-parietal area. Meanwhile, significant FN400 old/new effects were observed in the negative and rewarded positive items, and the old/new effects of negative items appeared earlier at FN400 than positive items. Also, significant late positive component (LPC) old/new effects were found in the positive, negative, and rewarded neutral items. These results suggest that, monetary reward and negative emotion significantly improved recognition performance, and there was a mutual influence between reward and emotion on brain activity during memory retrieval. PMID:29118728

Positive messaging promotes walking in older adults

PubMed Central

Notthoff, Nanna; Carstensen, Laura L.

2014-01-01

Walking is among the most cost-effective and accessible means of exercise. Mounting evidence suggests that walking may help to maintain physical and cognitive independence in old age by preventing a variety of health problems. However, older Americans fall far short of meeting the daily recommendations for walking. In two studies, we examined whether considering older adults’ preferential attention to positive information may effectively enhance interventions aimed at promoting walking. In Study 1, we compared the effectiveness of positive, negative, and neutral messages to encourage walking (as measured with pedometers). Older adults who were informed about the benefits of walking walked more than those who were informed about the negative consequences of failing to walk, whereas younger adults were unaffected by framing valence. In Study 2, we examined within-person change in walking in older adults in response to positively- or negatively-framed messages over a 28-day period. Once again, positively-framed messages more effectively promoted walking than negatively-framed messages, and the effect was sustained across the intervention period. Together, these studies suggest that consideration of age-related changes in preferences for positive and negative information may inform the design of effective interventions to promote healthy lifestyles. Future research is needed to examine the mechanisms underlying the greater effectiveness of positively as opposed to negatively framed messages and the generalizability of findings to other intervention targets and other subpopulations of older adults. PMID:24956001

Aberration of a negative ion beam caused by space charge effect.

PubMed

Miyamoto, K; Wada, S; Hatayama, A

2010-02-01

Aberrations are inevitable when the charged particle beams are extracted, accelerated, transmitted, and focused with electrostatic and magnetic fields. In this study, we investigate the aberration of a negative ion accelerator for a neutral beam injector theoretically, especially the spherical aberration caused by the negative ion beam expansion due to the space charge effect. The negative ion current density profiles with the spherical aberration are compared with those without the spherical aberration. It is found that the negative ion current density profiles in a log scale are tailed due to the spherical aberration.

Negative refraction and planar focusing based on parity-time symmetric metasurfaces.

PubMed

Fleury, Romain; Sounas, Dimitrios L; Alù, Andrea

2014-07-11

We introduce a new mechanism to realize negative refraction and planar focusing using a pair of parity-time symmetric metasurfaces. In contrast to existing solutions that achieve these effects with negative-index metamaterials or phase conjugating surfaces, the proposed parity-time symmetric lens enables loss-free, all-angle negative refraction and planar focusing in free space, without relying on bulk metamaterials or nonlinear effects. This concept may represent a pivotal step towards loss-free negative refraction and highly efficient planar focusing by exploiting the largely uncharted scattering properties of parity-time symmetric systems.

Could the negative effects of static stretching in warm-up be restored by sport specific exercise?

PubMed

Bengtsson, Victor; Yu, Ji-Guo; Gilenstam, Kajsa

2017-04-13

Static stretching (SS) is widely used in warm-up as it is generally believed to increase mobility and reduce the risk of injury; however, SS has been shown to induce transient negative effects on subsequent muscle performance. Interestingly, recent studies have shown that sport specific exercise could restore SS-induced negative effects on certain sports, especially of explosive muscular performance. Whether sport specific exercise could restore SS-induced negative effects on isokinetic muscle performance remains unclear. The present study conducted two different warm-ups: 2-component warm-up and 3-component warm-up on 15 university students. Both protocols contained low intensity aerobic exercise and sport specific exercise, whereas the 3-component warm-up also contained SS which has been previously proven to induce negative effects on subsequent muscle performance. After the warm-ups, the subjects performed an isokinetic test on a Biodex. To make the sport specific exercise mimic the subsequent test, both included concentric isokinetic knee extension. During the tests, muscle performance of peak torque, mean power, and total work was recorded. Comparison of the measurements on each parameter between the two warm-ups was performed using paired t test. The comparisons did not reveal any significant difference in the measurement of any parameter between the two different warm-up protocols, and calculation of Cohen's revealed small effect sizes on all of the three variables. On basis of the present results and that the SS could induce transient negative effects on subsequent muscle performance, we concluded that the negative effects of the SS on the variables were restored by the isokinetic contractions.

Differential interference effects of negative emotional states on subsequent semantic and perceptual processing

PubMed Central

Gorlick, Marissa A.; Mather, Mara

2012-01-01

Past studies have revealed that encountering negative events interferes with cognitive processing of subsequent stimuli. The present study investigated whether negative events affect semantic and perceptual processing differently. Presentation of negative pictures produced slower reaction times than neutral or positive pictures in tasks that require semantic processing, such as natural/man-made judgments about drawings of objects, commonness judgments about objects, and categorical judgments about pairs of words. In contrast, negative picture presentation did not slow down judgments in subsequent perceptual processing (e.g., color judgments about words, and size judgments about objects). The subjective arousal level of negative pictures did not modulate the interference effects on semantic/perceptual processing. These findings indicate that encountering negative emotional events interferes with semantic processing of subsequent stimuli more strongly than perceptual processing, and that not all types of subsequent cognitive processing are impaired by negative events. PMID:22142207

Monoamine Oxidase A (MAOA) Genotype Predicts Greater Aggression Through Impulsive Reactivity to Negative Affect

PubMed Central

Chester, David S.; DeWall, C. Nathan; Derefinko, Karen J.; Estus, Steven; Peters, Jessica R.; Lynam, Donald R.; Jiang, Yang

2015-01-01

Low functioning MAOA genotypes have been reliably linked to increased reactive aggression, yet the psychological mechanisms of this effect remain largely unknown. The low functioning MAOA genotype’s established link to diminished inhibition and greater reactivity to conditions of negative affect suggest that negative urgency, the tendency to act impulsively in the context of negative affect, may fill this mediating role. Such MAOA carriers may have higher negative urgency, which may in turn predict greater aggressive responses to provocation. To test these hypotheses, 277 female and male participants were genotyped for an MAOA SNP yet to be linked to aggression (rs1465108), and then reported their negative urgency and past aggressive behavior. We replicated the effect of the low functioning MAOA genotype on heightened aggression, which was mediated by greater negative urgency. These results suggest that disrupted serotonergic systems predispose individuals towards aggressive behavior by increasing impulsive reactivity to negative affect. PMID:25637908

Differential interference effects of negative emotional states on subsequent semantic and perceptual processing.

PubMed

Sakaki, Michiko; Gorlick, Marissa A; Mather, Mara

2011-12-01

Past studies have revealed that encountering negative events interferes with cognitive processing of subsequent stimuli. The present study investigates whether negative events affect semantic and perceptual processing differently. Presentation of negative pictures produced slower reaction times than neutral or positive pictures in tasks that require semantic processing, such as natural or man-made judgments about drawings of objects, commonness judgments about objects, and categorical judgments about pairs of words. In contrast, negative picture presentation did not slow down judgments in subsequent perceptual processing (e.g., color judgments about words, size judgments about objects). The subjective arousal level of negative pictures did not modulate the interference effects on semantic or perceptual processing. These findings indicate that encountering negative emotional events interferes with semantic processing of subsequent stimuli more strongly than perceptual processing, and that not all types of subsequent cognitive processing are impaired by negative events. (c) 2011 APA, all rights reserved.

The amphetamine response moderates the relationship between negative emotionality and alcohol use.

PubMed

Allen, Kenneth J D; Gabbay, Frances H

2013-02-01

Considerable evidence suggests that sensitivity to the stimulant effects of alcohol and other drugs is a risk marker for heavy or problematic use of those substances. A separate body of research implicates negative emotionality. The goal of the present study was to evaluate the independent and interactive effects of the stimulant response, assessed with an amphetamine challenge, and negative emotionality on alcohol and drug use. Healthy young women and men completed the Multidimensional Personality Questionnaire (MPQ) and an inventory assessing alcohol and other drug use. Subsequently, the effects of 10-mg d-amphetamine were determined in the laboratory using the Stimulant scale of the Biphasic Alcohol Effects Scale. Hierarchical regression analyses evaluated the effects of amphetamine response and the MPQ factor Negative Emotionality on measures of substance use. The amphetamine response moderated relationships between negative emotionality and alcohol use: in combination with a robust amphetamine response (i.e., enhanced stimulant effects as compared with baseline), negative emotionality predicted greater alcohol consumption, more episodes of binge drinking, and more frequent intoxication in regression models. A strong stimulant response independently predicted having used an illicit drug, and there was a trend for it to predict having used alcohol. Negative emotionality alone was not associated with any measure of alcohol or drug use. Consistent with the idea that emotion-based behavioral dysregulation promotes reward seeking, a high level of negative emotionality was associated with maladaptive alcohol use when it co-occurred with sensitivity to drug-based reward. The findings contribute to our understanding of how differences in personality may interact with those in drug response to affect alcohol use. Copyright © 2012 by the Research Society on Alcoholism.

The amphetamine response moderates the relationship between negative emotionality and alcohol use

PubMed Central

Allen, Kenneth J. D.; Gabbay, Frances H.

2012-01-01

Background Considerable evidence suggests that sensitivity to the stimulant effects of alcohol and other drugs is a risk marker for heavy or problematic use of those substances. A separate body of research implicates negative emotionality. The goal of the present study was to evaluate the independent and interactive effects of the stimulant response, assessed with an amphetamine challenge, and negative emotionality on alcohol and drug use. Methods Healthy young women and men completed the Multidimensional Personality Questionnaire (MPQ) and an inventory assessing alcohol and other drug use. Subsequently, the effects of 10 mg d-amphetamine were determined in the laboratory using the Stimulant scale of the Biphasic Alcohol Effects Scale. Hierarchical regression analyses evaluated the effects of amphetamine response and the MPQ factor Negative Emotionality on measures of substance use. Results The amphetamine response moderated relationships between negative emotionality and alcohol use: In combination with a robust amphetamine response (i.e., enhanced stimulant effects as compared to baseline), negative emotionality predicted greater alcohol consumption, more episodes of binge drinking, and more frequent intoxication in regression models. A strong stimulant response independently predicted having used an illicit drug, and there was a trend for it to predict having used alcohol. Negative emotionality alone was not associated with any measure of alcohol or drug use. Conclusions Consistent with the idea that emotion-based behavioral dysregulation promotes reward-seeking, a high level of negative emotionality was associated with maladaptive alcohol use when it co-occurred with sensitivity to drug-based reward. The findings contribute to our understanding of how differences in personality may interact with those in drug response to affect alcohol use. PMID:23240777

Selective mood-induced body image disparagement and enhancement effects: are they due to cognitive priming or subjective mood?

PubMed

Rotenberg, Ken J; Taylor, Daniel; Davis, Ron

2004-04-01

The study evaluated the effects of mood induction procedures on body image. Eighty female undergraduates participated in combinations of two valences (negative vs. positive) and two types (self-referent vs. other-referent) of mood induction procedures (MIPs). A measure of subjective mood and seven measures of body image were administered before and after the MIPs. Individuals in the self-referent MIP who had high negative body image at the pretest demonstrated increases in negative body image after exposure to the negative valence MIP (a disparagement effect) and decreases in negative body image after exposure to the positive valence MIP (an enhancement effect). This pattern was not evident in the other-referent MIP. Also, changes in negative body image were not appreciably associated with changes in subjective mood. The findings yielded support for the cognitive priming hypothesis but not for the subjective mood hypothesis. Further means of examining the cognitive priming hypothesis were outlined. Copyright 2004 by Wiley Periodicals, Inc. Int J Eat Disord 35: 317-332, 2004.

The moderating effects of aging and cognitive abilities on the association between work stress and negative affect.

PubMed

Hyun, Jinshil; Sliwinski, Martin J; Almeida, David M; Smyth, Joshua M; Scott, Stacey B

2018-05-01

Given that the association between work stress and negative affect can exacerbate negative health and workplace outcomes, it is important to identify the protective and risk factors that moderate this association. Socioemotional aging and cognitive abilities might influence how people utilize emotion regulation skills and engage in practical problem solving to manage their work stress. The aim of this study is to examine whether age and cognitive abilities independently and interactively moderate the association between work-related stress and negative affect. A diverse working adult sample (N = 139, age 25-65, 69% of females) completed a cross-sectional survey that assessed chronic work stress, negative affect, and fluid and crystallized cognitive abilities. Results from regression analyses suggested that both fluid and crystallized cognitive abilities, but not age, moderated the association between work stress and negative affect. Further, we found that crystallized cognition had a stronger attenuating effect on the work stress-negative affect association for older compared to younger workers. The moderating effect of fluid cognition was invariant across age. Our findings demonstrate that cognitive abilities are an important personal resource that might protect individuals against the negative impacts of work stress and negative affect. Although the role that fluid cognition plays in work stress-negative affect association is comparably important for both younger and older workers, crystallized cognition might play a more valuable role for older than younger workers.

Valence asymmetries in attitude ambivalence.

PubMed

Snyder, Aaron I; Tormala, Zakary L

2017-04-01

Existing models of ambivalence suggest that as the number of conflicting reactions (e.g., attitude components) increases, so too does the experience of ambivalence. Interestingly, though, these models overwhelmingly assume that this relationship is independent of valence. Across 3 studies we observe that this effect is in fact heavily influenced by 2 established valence asymmetries: positivity offset (baseline positive reactions even in the absence of positive information) and negativity bias (greater impact of negative reactions than positive reactions). Consistent with positivity offset, we observe that subjective ambivalence is greater when people have univalent negative rather than univalent positive attitudes. However, as conflicting information is acquired, subjective ambivalence rises more quickly when that information is negative rather than positive. The latter effect is consistent with negativity bias and suggests that although people feel more conflicted when they have only negative (vs. only positive) reactions, they also feel more conflicted when they have mostly positive (vs. mostly negative) reactions. Our investigation also uncovers an interesting consequence of these asymmetries: When people have mixed reactions, they do not experience maximum ambivalence at equal levels of positivity and negativity, as suggested by canonical ambivalence theory. Rather, subjective ambivalence peaks when positive reactions outnumber negative reactions. These effects are found to have downstream consequences for other dimensions of attitude strength. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

Feeling Better About Self After Receiving Negative Feedback: When the Sense That Ability Can Be Improved Is Activated.

PubMed

Hu, Xinyi; Chen, Yinghe; Tian, Baowei

2016-01-01

Past studies suggest that managers and educators often consider negative feedback as a motivator for individuals to think about their shortcomings and improve their work, but delivering negative feedback does not always achieve desired results. The present study, based on incremental theory, employed an intervention method to activate the belief that a particular ability could be improved after negative feedback. Three experiments tested the intervention effect on negative self-relevant emotion. Study 1 indicated conveying suggestions for improving ability reduced negative self-relevant emotion after negative feedback. Study 2 tested whether activating the sense of possible improvement in the ability could reduce negative self-relevant emotion. Results indicated activating the belief that ability could be improved reduced negative self-relevant emotion after failure, but delivering emotion management information alone did not yield the same effect. Study 3 extended the results by affirming the effort participants made in doing the test, and found the affirmation reduced negative self-relevant emotion. Collectively, the findings indicated focusing on the belief that the ability could be improved in the future can reduce negative self-relevant emotion after negative feedback.

Neural evidence for description dependent reward processing in the framing effect.

PubMed

Yu, Rongjun; Zhang, Ping

2014-01-01

Human decision making can be influenced by emotionally valenced contexts, known as the framing effect. We used event-related brain potentials to investigate how framing influences the encoding of reward. We found that the feedback related negativity (FRN), which indexes the "worse than expected" negative prediction error in the anterior cingulate cortex (ACC), was more negative for the negative frame than for the positive frame in the win domain. Consistent with previous findings that the FRN is not sensitive to "better than expected" positive prediction error, the FRN did not differentiate the positive and negative frame in the loss domain. Our results provide neural evidence that the description invariance principle which states that reward representation and decision making are not influenced by how options are presented is violated in the framing effect.

Work-life balance culture, work-home interaction, and emotional exhaustion: a structural equation modeling approach.

PubMed

Nitzsche, Anika; Pfaff, Holger; Jung, Julia; Driller, Elke

2013-01-01

To examine the relationships among employees' emotional exhaustion, positive and negative work-home interaction, and perceived work-life balance culture in companies. Data for this study were collected through online surveys of employees from companies in the micro- and nanotechnology sectors (N = 509). A structural equation modeling analysis was performed. A company culture perceived by employees as supportive of their work-life balance was found to have both a direct negative effect on emotional exhaustion and an indirect negative effect meditated by negative work-home interaction. In addition, whereas negative work-home interaction associated positively with emotional exhaustion, positive work-home interaction had no significant effect. The direct and indirect relationship between work-life balance culture and emotional exhaustion has practical implications for health promotion in companies.

A Newtonian approach to extraordinarily strong negative refraction.

PubMed

Yoon, Hosang; Yeung, Kitty Y M; Umansky, Vladimir; Ham, Donhee

2012-08-02

Metamaterials with negative refractive indices can manipulate electromagnetic waves in unusual ways, and can be used to achieve, for example, sub-diffraction-limit focusing, the bending of light in the 'wrong' direction, and reversed Doppler and Cerenkov effects. These counterintuitive and technologically useful behaviours have spurred considerable efforts to synthesize a broad array of negative-index metamaterials with engineered electric, magnetic or optical properties. Here we demonstrate another route to negative refraction by exploiting the inertia of electrons in semiconductor two-dimensional electron gases, collectively accelerated by electromagnetic waves according to Newton's second law of motion, where this acceleration effect manifests as kinetic inductance. Using kinetic inductance to attain negative refraction was theoretically proposed for three-dimensional metallic nanoparticles and seen experimentally with surface plasmons on the surface of a three-dimensional metal. The two-dimensional electron gas that we use at cryogenic temperatures has a larger kinetic inductance than three-dimensional metals, leading to extraordinarily strong negative refraction at gigahertz frequencies, with an index as large as -700. This pronounced negative refractive index and the corresponding reduction in the effective wavelength opens a path to miniaturization in the science and technology of negative refraction.

Associations Between Infant Negative Affect and Parent Anxiety Symptoms are Bidirectional: Evidence from Mothers and Fathers

PubMed Central

Brooker, Rebecca J.; Neiderhiser, Jenae M.; Leve, Leslie D.; Shaw, Daniel S.; Scaramella, Laura V.; Reiss, David

2015-01-01

Little is known about child-based effects on parents’ anxiety symptoms early in life despite the possibility that child characteristics may contribute to the quality of the early environment and children’s own long-term risk for psychological disorder. We examined bidirectional effects between parent anxiety symptoms and infant negative affect using a prospective adoption design. Infant negative affect and adoptive parent anxiety symptoms were assessed at child ages 9, 18, and 27 months. Birth parent negative affect was assessed at child age 18 months. More anxiety symptoms in adoptive parents at child age 9 months predicted more negative affect in infants 9 months later. More infant negative affect at child age 9 months predicted more anxiety symptoms in adoptive parents 18 months later. Patterns of results did not differ for adoptive mothers and adoptive fathers. Birth parent negative affect was unrelated to infant or adoptive parent measures. Consistent with expectations, associations between infant negative affect and rearing parents’ anxiety symptoms appear to be bidirectional. In addition to traditional parent-to-child effects, our results suggest that infants’ characteristics may contribute to parent qualities that are known to impact childhood outcomes. PMID:26696939

Effect of post-encoding emotion on recollection and familiarity for pictures.

PubMed

Wang, Bo; Ren, Yanju

2017-07-01

Although prior studies have examined the effect of post-encoding emotional arousal on recognition memory for words, it is unknown whether the enhancement effect observed on words generalizes to pictures. Furthermore, prior studies using words have showed that the effect of emotional arousal can be modulated by stimuli valence and delay in emotion induction, but it is unclear whether such modulation can extend to pictures and whether other factors such as encoding method (incidental vs. intentional encoding) can be modulatory. Five experiments were conducted to answer these questions. In Experiment 1, participants encoded a list of neutral and negative pictures and then watched a 3-min neutral or negative video. The delayed test showed that negative arousal impaired recollection regardless of picture valence but had no effect on familiarity. Experiment 2 replicated the above findings. Experiment 3 was similar to Experiment 1 except that participants watched a 3-min neutral, negative, or positive video and conducted free recall before the recognition test. Unlike the prior two experiments, the impairment effect of negative arousal disappeared. Experiment 4, where the free recall task was eliminated, replicated the results from Experiment 3. Experiment 5 replicated Experiments 1 and 2 and further showed that the impairment effects of negative arousal could be modulated by delay in emotion induction but not by encoding method or stimuli valence. Taken together, the current study suggests that the enhancement effect observed on words may not generalize to pictures.

Generation and context memory.

PubMed

Mulligan, Neil W; Lozito, Jeffrey P; Rosner, Zachary A

2006-07-01

Generation enhances memory for occurrence but may not enhance other aspects of memory. The present study further delineates the negative generation effect in context memory reported in N. W. Mulligan (2004). First, the negative generation effect occurred for perceptual attributes of the target item (its color and font) but not for extratarget aspects of context (location and background color). Second, nonvisual generation tasks with either semantic or nonsemantic generation rules (antonym and rhyme generation, respectively) produced the same pattern of results. In contrast, a visual (or data-driven) generation task (letter transposition) did not disrupt context memory for color. Third, generating nonwords produced no effect on item memory but persisted in producing a negative effect on context memory for target attributes, implying that (a) the negative generation effect in context memory is not mediated by semantic encoding, and (b) the negative effect on context memory can be dissociated from the positive effect on item memory. The results are interpreted in terms of the processing account of generation. The original, perceptual-conceptual version of this account is too narrow, but a modified processing account, based on a more generic visual versus nonvisual processing distinction, accommodates the results. Copyright 2006 APA, all rights reserved.

Understanding the Function of Emotional Eating: Does it Buffer the Stress Response and Help Us Cope

DTIC Science & Technology

2008-05-09

Eating and Coping 25 these negative effects were most likely related to their presumed impact on health and weight. E. Comfort Foods...2003). Coping strategies can either amplify or reduce the stress experience, and therefore can either negatively or positively effect health...clinical behavior to understand. Finally, the effectiveness of stressors is much higher for negative stress than for positive (Westermann et al., 1996

Estimates of 2012/13 influenza vaccine effectiveness using the case test-negative control design with different influenza negative control groups.

PubMed

Nunes, Baltazar; Machado, Ausenda; Guiomar, Raquel; Pechirra, Pedro; Conde, Patrícia; Cristovão, Paula; Falcão, Isabel

2014-07-31

In recent years several reports of influenza vaccine effectiveness (VE) have been made early for public health decision. The majority of these studies use the case test-negative control design (TND), which has been showed to provide, under certain conditions, unbiased estimates of influenza VE. Nevertheless, discussions have been taken on the best influenza negative control group to use. The present study aims to contribute to the knowledge on this field by comparing influenza VE estimates using three test-negative controls: all influenza negative, non-influenza respiratory virus and pan-negative. Incident ILI patients were prospectively selected and swabbed by a sample of general practitioners. Cases were ILI patients tested positive for influenza and controls ILI patients tested negative for influenza. The influenza negative control group was divided into non-influenza virus control group and pan-negative control group. Data were collected on vaccination status and confounding factors. Influenza VE was estimated as one minus the odds ratio of been vaccinated in cases versus controls adjusted for confounding effect by logistic regression. Confounder adjusted influenza VE against medically attended laboratory-confirmed influenza was 68.4% (95% CI: 20.7-87.4%) using all influenza negatives controls, 82.1% (95% CI: 47.6-93.9%) using non-influenza controls and 49.4% (95% CI: -44.7% to 82.3%) using pan-negative controls. Influenza VE estimates differed according to the influenza negative control group used. These results are in accordance with the expected under the hypothesis of differential viral interference between influenza vaccinated and unvaccinated individuals. Given the wide importance of TND study further studies should be conducted in order to clarify the observed differences. Copyright © 2014 Elsevier Ltd. All rights reserved.

Heat shock protein 90 (HSP90) is overexpressed in p16-negative oropharyngeal squamous cell carcinoma, and its inhibition in vitro potentiates the effects of chemoradiation.

PubMed

Patel, Kirtesh; Wen, Jing; Magliocca, Kelly; Muller, Susan; Liu, Yuan; Chen, Zhuo Georgia; Saba, Nabil; Diaz, Roberto

2014-11-01

Cisplatin and radiation therapy remain the current standard for treating locally advanced SCCHN. Novel treatment approaches are needed, especially in patients with human papilloma virus (HPV)-negative disease who have worse outcomes despite multimodality therapy. Using our institutional review board approved database, we obtained twenty oropharyngeal squamous cell carcinoma (SCC) tissue samples: ten p16 positive, ten p16-negative. Because p16 expression is strongly associated with HPV positivity in oropharyngeal SCC, p16 status was used as a marker of HPV. We subsequently analyzed, via immunohistochemistry, heat shock protein 90 (HSP90) protein levels. Using HPV-positive and HPV-negative SCC cell lines, we compared baseline HSP90 expression levels and the effect of the HSP90 inhibitor ganetespib on viability and apoptosis. Clonogenic survival of HPV-negative cells treated with ganetespib, radiation therapy, and/or cisplatin was then investigated. We characterize the effects of ganetespib on proteins that are thought to drive DNA damage resistance in HPV-negative cells. HSP90 expression was significantly higher in p16-negative compared with p16-positive samples (p = 0.016) and in HPV-negative cell lines compared with positive cells. Ganetespib increased cytotoxicity and induced apoptosis in HPV-negative more than positive cells. Adding ganetespib to cisplatin and/or radiation therapy in HPV-negative cells further decreased clonogenic survival. Finally, ganetespib downregulated expressions of EGFR, ERK, AKT, p53, and HIF-1α. Ganetespib inhibited HPV-negative SCCHN viability and potentiated cell kill when combined with cisplatin or radiation therapy in vitro. With HSP90 expression higher in HPV-negative cells and in p16-negative patients, further exploration of the clinical activity of HSP90 inhibitors in SCCHN is warranted.

Inverse Doppler Effects in Broadband Acoustic Metamaterials

PubMed Central

Zhai, S. L.; Zhao, X. P.; Liu, S.; Shen, F. L.; Li, L. L.; Luo, C. R.

2016-01-01

The Doppler effect refers to the change in frequency of a wave source as a consequence of the relative motion between the source and an observer. Veselago theoretically predicted that materials with negative refractions can induce inverse Doppler effects. With the development of metamaterials, inverse Doppler effects have been extensively investigated. However, the ideal material parameters prescribed by these metamaterial design approaches are complex and also challenging to obtain experimentally. Here, we demonstrated a method of designing and experimentally characterising arbitrary broadband acoustic metamaterials. These omni-directional, double-negative, acoustic metamaterials are constructed with ‘flute-like’ acoustic meta-cluster sets with seven double meta-molecules; these metamaterials also overcome the limitations of broadband negative bulk modulus and mass density to provide a region of negative refraction and inverse Doppler effects. It was also shown that inverse Doppler effects can be detected in a flute, which has been popular for thousands of years in Asia and Europe. PMID:27578317

Inverse Doppler Effects in Broadband Acoustic Metamaterials

NASA Astrophysics Data System (ADS)

Zhai, S. L.; Zhao, X. P.; Liu, S.; Shen, F. L.; Li, L. L.; Luo, C. R.

2016-08-01

The Doppler effect refers to the change in frequency of a wave source as a consequence of the relative motion between the source and an observer. Veselago theoretically predicted that materials with negative refractions can induce inverse Doppler effects. With the development of metamaterials, inverse Doppler effects have been extensively investigated. However, the ideal material parameters prescribed by these metamaterial design approaches are complex and also challenging to obtain experimentally. Here, we demonstrated a method of designing and experimentally characterising arbitrary broadband acoustic metamaterials. These omni-directional, double-negative, acoustic metamaterials are constructed with ‘flute-like’ acoustic meta-cluster sets with seven double meta-molecules; these metamaterials also overcome the limitations of broadband negative bulk modulus and mass density to provide a region of negative refraction and inverse Doppler effects. It was also shown that inverse Doppler effects can be detected in a flute, which has been popular for thousands of years in Asia and Europe.

What matters when judging intentionality-moral content or normative status? Testing the rational scientist model of the side-effect.

PubMed

Papadopoulos, C; Hayes, B K

2018-06-01

Previous work has demonstrated a "side-effect effect," such that intentionality is more likely to be attributed to agents who bring about negatively valenced as opposed to positively valenced side effects. The rational-scientist model explains this by suggesting that norm-violating side effects are more informative for inferring intentionality than norm-conforming side effects. In the present study we reexamined this account, addressing limitations of previous empirical tests (e.g., Uttich & Lombrozo, Cognition 116: 87-100, 2010). Side-effect valence and norm status were manipulated factorially, enabling an examination of the impact of norm status on intentionality judgments in both positively and negatively valenced side effects. Additionally, the impact of side-effect norm status on the perceived valences of side effects and agents was examined. Effects of norm status were found for both positive and negative side effects. Violation of an ostensibly neutral norm led to negative perceptions of the side effect. However, a norm status effect on intentionality judgments persisted when these effects were controlled. These results support the view that the side-effect effect is the result of the rational use of social-cognitive evidence.

Learning to Dislike Chocolate: Conditioning Negative Attitudes toward Chocolate and Its Effect on Chocolate Consumption.

PubMed

Wang, Yan; Wang, Guosen; Zhang, Dingyuan; Wang, Lei; Cui, Xianghua; Zhu, Jinglei; Fang, Yuan

2017-01-01

Evaluative conditioning (EC) procedures can be used to form and change attitudes toward a wide variety of objects. The current study examined the effects of a negative EC procedure on attitudes toward chocolate, and whether it influenced chocolate evaluation and consumption. Participants were randomly assigned to the experimental condition in which chocolate images were paired with negative stimuli, or the control condition in which chocolate images were randomly paired with positive stimuli (50%) and negative stimuli (50%). Explicit and implicit attitudes toward chocolate images were collected. During an ostensible taste test, chocolate evaluation and consumption were assessed. Results revealed that compared to participants in the control condition, participants in the experimental condition showed more negative explicit and implicit attitudes toward chocolate images and evaluated chocolate more negatively during the taste test. However, chocolate consumption did not differ between experimental and control conditions. These findings suggest that pairing chocolate with negative stimuli can influence attitudes toward chocolate, though behavioral effects are absent. Intervention applications of EC provide avenues for future research and practices.

Are positive and negative reinforcement "different"? Insights from a free-operant differential outcomes effect.

PubMed

Magoon, Michael A; Critchfield, Thomas S; Merrill, Dustin; Newland, M Christopher; Schneider, W Joel

2017-01-01

Although theoretical discussions typically assume that positive and negative reinforcement differ, the literature contains little unambiguous evidence that they produce differential behavioral effects. To test whether the two types of consequences control behavior differently, we pitted money-gain positive reinforcement and money-loss-avoidance negative reinforcement, scheduled through identically programmed variable-cycle schedules, against each other in concurrent schedules. Contingencies of response-produced feedback, normally different in positive and negative reinforcement, were made symmetrical. Steeper matching slopes were produced compared to a baseline consisting of all positive reinforcement. This free-operant differential outcomes effect supports the notion that that stimulus-presentation positive reinforcement and stimulus-elimination negative reinforcement are functionally "different." However, a control experiment showed that the feedback asymmetry of more traditional positive and negative reinforcement schedules also is sufficient to create a "difference" when the type of consequence is held constant. We offer these findings as a small step in meeting the very large challenge of moving negative reinforcement theory beyond decades of relative quiescence. © 2017 Society for the Experimental Analysis of Behavior.

Learning to Dislike Chocolate: Conditioning Negative Attitudes toward Chocolate and Its Effect on Chocolate Consumption

PubMed Central

Wang, Yan; Wang, Guosen; Zhang, Dingyuan; Wang, Lei; Cui, Xianghua; Zhu, Jinglei; Fang, Yuan

2017-01-01

Evaluative conditioning (EC) procedures can be used to form and change attitudes toward a wide variety of objects. The current study examined the effects of a negative EC procedure on attitudes toward chocolate, and whether it influenced chocolate evaluation and consumption. Participants were randomly assigned to the experimental condition in which chocolate images were paired with negative stimuli, or the control condition in which chocolate images were randomly paired with positive stimuli (50%) and negative stimuli (50%). Explicit and implicit attitudes toward chocolate images were collected. During an ostensible taste test, chocolate evaluation and consumption were assessed. Results revealed that compared to participants in the control condition, participants in the experimental condition showed more negative explicit and implicit attitudes toward chocolate images and evaluated chocolate more negatively during the taste test. However, chocolate consumption did not differ between experimental and control conditions. These findings suggest that pairing chocolate with negative stimuli can influence attitudes toward chocolate, though behavioral effects are absent. Intervention applications of EC provide avenues for future research and practices. PMID:28900409

Promoting walking in older adults: Perceived neighborhood walkability influences the effectiveness of motivational messages

PubMed Central

Notthoff, Nanna; Carstensen, Laura L.

2015-01-01

Positively-framed messages seem to promote walking in older adults better than negatively-framed messages. This study targeted elderly people in communities unfavorable to walking. Walking was measured with pedometers during baseline (one week) and intervention (four weeks). Participants (n = 74) were either informed about the benefits of walking or the negative consequences of not walking. Perceived neighborhood walkability was assessed with a modified version of the Neighborhood Walkability Scale. When perceived walkability was high positively-framed messages were more effective than negatively-framed messages in promoting walking; when perceived walkability was low negatively-framed messages were comparably effective to positively-framed messages. PMID:26604128

Conflict-driven adaptive control is enhanced by integral negative emotion on a short time scale.

PubMed

Yang, Qian; Pourtois, Gilles

2018-02-05

Negative emotion influences cognitive control, and more specifically conflict adaptation. However, discrepant results have often been reported in the literature. In this study, we broke down negative emotion into integral and incidental components using a modern motivation-based framework, and assessed whether the former could change conflict adaptation. In the first experiment, we manipulated the duration of the inter-trial-interval (ITI) to assess the actual time-scale of this effect. Integral negative emotion was induced by using loss-related feedback contingent on task performance, and measured at the subjective and physiological levels. Results showed that conflict-driven adaptive control was enhanced when integral negative emotion was elicited, compared to a control condition without changes in defensive motivation. Importantly, this effect was only found when a short, as opposed to long ITI was used, suggesting that it had a short time scale. In the second experiment, we controlled for effects of feature repetition and contingency learning, and replicated an enhanced conflict adaptation effect when integral negative emotion was elicited and a short ITI was used. We interpret these new results against a standard cognitive control framework assuming that integral negative emotion amplifies specific control signals transiently, and in turn enhances conflict adaptation.

Neuroticism, coping strategies, and negative well-being among caregivers.

PubMed

Patrick, J H; Hayden, J M

1999-06-01

Neuroticism was incorporated into a model for predicting the well-being of family caregivers. Using data from 596 women with an adult child with a chronic disability, the model hypothesizes direct effects of neuroticism on a caregiver's perceptions of the stressor, on her wishful-escapism and problem-focused coping, and on psychological well-being. Results indicate that neuroticism exerts direct and indirect effects on negative well-being. Results also indicate that stressors have direct effects on both wishful-escapism coping and problem-focused coping. Burden had direct effects on negative psychological well-being. Diagnosis influences the model by having direct effects on stressors and wishful-escapism coping but not on problem-focused coping or burden. Inclusion of individual level variables, such as neuroticism, results in a substantial amount of explained variance in negative well-being.

Benefits of negative social exchanges for emotional closeness.

PubMed

Fung, Helene H; Yeung, Dannii Y; Li, Kin-Kit; Lang, Frieder R

2009-09-01

Negative exchanges in social relationships have traditionally been studied as having negative consequences. This study explored whether they might have positive effects for relationship closeness. The sample included 351 adults, aged between 18 and 91 years, residing in Hong Kong, China. Closeness of social partners to the participants was measured by the Social Convoy Questionnaire, and the levels of negative exchanges and social support from each social partner were assessed. Multilevel analyses revealed that more negative exchanges were associated with a more positive change in closeness over a 2-year period, even after statistically controlling for social support and sociostructural characteristics of the participant and the social partner. Findings extended our knowledge on the positive effects of negative exchanges and their moderating conditions.

Negative index effects from a homogeneous positive index prism

NASA Astrophysics Data System (ADS)

Marcus, Sherman W.; Epstein, Ariel

2017-12-01

Cellular structured negative index metamaterials in the form of a right triangular prism have often been tested by observing the refraction of a beam across the prism hypotenuse which is serrated in order to conform to the cell walls. We show that not only can this negative index effect be obtained from a homogeneous dielectric prism having a positive index of refraction, but in addition, for sampling at the walls of the cellular structure, the phase in the material has the illusory appearance of moving in a negative direction. Although many previous reports relied on refraction direction and phase velocity of prism structures to verify negative index design, our investigation indicates that to unambiguously demonstrate material negativity additional empirical evidence is required.

Can Contrast Effects Regulate Emotions? A Follow-Up Study of Vital Loss Decisions

PubMed Central

Liu, Xianyun; Luo, Jing

2012-01-01

Although many studies focus on the how contrast effects can impact cognitive evaluations, the question of whether emotions are regulated by such contrast effects is still the subject of considerable debate, especially in the study of loss-related decisions. To address this gap in the literature, we designed three decision making loss conditions: (i) both losses are trivial (TT), (ii) one loss is trivial and the other loss is vital (TV), or (iii) one loss is trivial and the other loss is routine (TR). In study 1, which compared the difference between the negative emotion ratings in TT and TV, we found that negative emotions were affected by the contrast effects. In study 2, which compared the difference between the importance of trivial options in TT and TV, we found that the contrast effects differentially changed the importance of trivial options in the two conditions, which in turn down-regulated negative emotions. In study 3, the impact of decision difficulty was controlled by predetermining the items to be lost. In this study, we found that, when comparing the differences between the negative emotions of losing trivial options in TV and TR, the contrast effects still modulated the loss-related emotions. We concluded that the contrast effects could down-regulate emotions. To our knowledge, this is the first demonstration that contrast effects can alleviate negative affect in loss-related decision making. This study will enrich and extend the literature on emotion regulation theory, and it will provide a new cost-effective mitigation strategy for regulating negative emotions. PMID:22905170

Targeted Gene Silencing of Tumor Necrosis Factor Attenuates the Negative Inotropic Effects of Lipopolysaccharide in Isolated Contracting Cardiac Myocytes

PubMed Central

Ramabadran, R. S.; Chancey, Amanda; Vallejo, Jesus G.; Barger, Philip M.; Sivasubramanian, Natarajan; Mann, Douglas L.

2008-01-01

Bacterial endotoxin (lipopolysaccharide) depresses cardiovascular function; however, the mediators and signaling pathways that are responsible for the negative inotropic effects of lipopolysaccharide are not fully known. We used RNA interference to determine the relative role of tumor necrosis factor with respect to mediating the negative inotropic effects of lipopolysaccharide in isolated cardiac myocytes. Cardiac myocyte cultures were treated with lipopolysaccharide in the presence or absence of small interfering RNAs (siRNA) for tumor necrosis factor. We examined the effects of tumor necrosis factor siRNA on lipopolysaccharide-induced tumor necrosis factor messenger RNA (mRNA) and protein biosynthesis, as well as the negative inotropic effects of lipopolysaccharide in isolated contracting cardiac myocytes. Treatment of adult cardiac myocyte cultures with tumor necrosis factor siRNA significantly attenuated lipopolysaccharide-induced tumor necrosis factor mRNA and protein biosynthesis, whereas transfection with a double-stranded RNA that does not target mammalian mRNA had no effect. Pretreatment with tumor necrosis factor siRNA significantly attenuated, but did not abrogate, the lipopolysaccharide-induced decrease in sarcomere shortening in isolated contracting cardiac myocytes. In contrast, tumor necrosis factor siRNA had a comparatively smaller effect on improving sarcomere shortening once the negative inotropic effects of lipopolysaccharide were fully established. These results suggest that tumor necrosis factor plays an important upstream role in lipopolysaccharide-induced negative inotropic effects in isolated contracting cardiac myocytes and that other molecular mechanisms are responsible for the decrease in sarcomere shortening after sustained lipopolysaccharide signaling. PMID:18427645

Glyceollins as novel targeted therapeutic for the treatment of metastatic triple-negative breast cancer

USDA-ARS?s Scientific Manuscript database

The purpose of this study was to investigate the effects of glyceollins on the suppression of tumorigenesis in triple negative breast carcinoma cell lines. We further explored the effects of glyceollins on microRNA and protein expression in MDA MB 231 cells. Triple negative (ER , PgR, and Her2/neu ...

Nickel cadmium cell designs negative to positive material ratio and precharge levels

NASA Technical Reports Server (NTRS)

Gross, S.

1977-01-01

A review is made of the factors affecting the choices of negative-to-positive materials ratio and negative precharge in nickel-cadmium cells. The effects of these variables on performance are given, and the different methods for setting precharge are evaluated. The effects of special operating requirements on the design are also discussed.

A Fine-Grained Analysis of the Effects of Negative Evidence with and without Metalinguistic Information in Language Development

ERIC Educational Resources Information Center

Lado, Beatriz; Bowden, Harriet Wood; Stafford, Catherine A; Sanz, Cristina

2014-01-01

The current study compared the effectiveness of computer-delivered task-essential practice coupled with feedback consisting of (1) negative evidence with metalinguistic information (NE+MI) or (2) negative evidence without metalinguistic information (NE-MI) in promoting absolute beginners' (n = 58) initial learning of aspects of Latin…

On Buffers and Boosters: Social Support for Negative and Positive Life Events.

ERIC Educational Resources Information Center

Sandler, Irwin N.

Social support has been studied in the context of its relationship to and effect on negative experiences. While this buffer aspect of social support is important, support may also play a satisfaction-enhancing role. Both the negative event-buffering and positive event-boosting effect of social support on students' satisfaction with their college…

Negative Affect and Alcohol Use among Non-Hispanic White and Mexican American Adolescents.

ERIC Educational Resources Information Center

Swaim, Randall C.; Chen, Julie; Deffenbacher, Jerry L.; Newcomb, Michael D.

2001-01-01

Examines the effects of negative affect on adolescent alcohol use among non-Hispanic White and Mexican American 9-12th grade students. Results indicate that unique components of negative affect relate to adolescent alcohol use in different patterns across different groups of youth. However, the small magnitude of these effects calls into question…

Negative Effects of Reward on Intrinsic Motivation--A Limited Phenomenon: Comment on Deci, Koestner, and Ryan (2001).

ERIC Educational Resources Information Center

Cameron, Judy

2001-01-01

Prior meta analyses by J. Cameron and other researchers suggested that the negative effects of extrinsic reward on intrinsic motivation were limited and avoidable. E. Deci and others (2001) suggested that the analyses were flawed. This commentary makes the case that there is no inherent negative property of reward. (SLD)

Sex differences in effective fronto-limbic connectivity during negative emotion processing.

PubMed

Lungu, Ovidiu; Potvin, Stéphane; Tikàsz, Andràs; Mendrek, Adrianna

2015-12-01

In view of the greater prevalence of depression and anxiety disorders in women than in men, functional magnetic resonance imaging (fMRI) studies have examined sex-differences in brain activations during emotion processing. Comparatively, sex-differences in brain connectivity received little attention, despite evidence for important fronto-limbic connections during emotion processing across sexes. Here, we investigated sex-differences in fronto-limbic connectivity during negative emotion processing. Forty-six healthy individuals (25 women, 21 men) viewed negative, positive and neutral images during an fMRI session. Effective connectivity between significantly activated regions was examined using Granger causality and psychophysical interaction analyses. Sex steroid hormones and feminine-masculine traits were also measured. Subjective ratings of negative emotional images were higher in women than in men. Across sexes, significant activations were observed in the dorso-medial prefrontal cortex (dmPFC) and the right amygdala. Granger connectivity from right amygdala was significantly greater than that from dmPFC during the 'high negative' condition, an effect driven by men. Magnitude of this effect correlated negatively with highly negative image ratings and feminine traits and positively with testosterone levels. These results highlight critical sex differences in brain connectivity during negative emotion processing and point to the fact that both biological (sex steroid hormones) and psychosocial (gender role and identity) variables contribute to them. As the dmPFC is involved in social cognition and action planning, and the amygdala-in threat detection, the connectivity results suggest that compared to women, men have a more evaluative, rather than purely affective, brain response during negative emotion processing. Copyright © 2015 Elsevier Ltd. All rights reserved.

The interactive effects of negative symptoms and social role functioning on suicide ideation in individuals with schizophrenia.

PubMed

Jahn, Danielle R; Bennett, Melanie E; Park, Stephanie G; Gur, Raquel E; Horan, William P; Kring, Ann M; Blanchard, Jack J

2016-02-01

Findings regarding the protective effect of social role functioning on suicide ideation in individuals with schizophrenia have been mixed. One reason for such inconsistencies in the literature may be that individuals with prominent negative symptoms of schizophrenia may not experience a desire for social closeness, and therefore social role functioning may not influence suicide risk in these individuals. The aim of this study was to examine the moderating effects of self-reported desire for social closeness and interviewer-rated negative symptoms on the relationship between social role functioning and suicide ideation. Our sample consisted of 162 individuals who had been diagnosed with schizophrenia-spectrum disorders; all participants completed self-report questionnaires and clinician-administered interviews, and moderation hypotheses were tested with a non-parametric procedure. The results indicated that motivation and pleasure-related negative symptoms moderated the relationship between social role functioning and suicide ideation; self-reported desire for social closeness and negative symptoms related to expression did not have such a moderating effect. Specifically, better social role functioning was associated with less suicide ideation only in those individuals who had low motivation and pleasure-related negative symptoms; no significant relationship was observed between social role functioning and suicide ideation among those with elevated motivation and pleasure-related negative symptoms. These findings suggest that assessing for negative symptoms and social role functioning may inform suicide risk assessments in individuals with schizophrenia, and improving social role functioning may reduce suicide ideation among those with few motivation and pleasure-related negative symptoms. Copyright © 2015 Elsevier B.V. All rights reserved.

The roles of negative affect and goal adjustment capacities in breast cancer survivors: Associations with physical activity and diurnal cortisol secretion.

PubMed

Castonguay, Andree L; Wrosch, Carsten; Sabiston, Catherine M

2017-04-01

This study examined whether within-person changes of breast cancer survivors' high-arousal negative affect (e.g., feeling scared, upset, anxious, or guilty) could predict high levels of diurnal cortisol secretion and moderate-to-vigorous physical activity (MVPA). In addition, goal adjustment capacities (goal disengagement and goal reengagement) were expected to buffer the effect of negative affect on cortisol and to increase its effect on MVPA. High-arousal negative affect, self-reported MVPA, area-under-the-curve of diurnal cortisol secretion, and goal adjustment capacities were assessed in a longitudinal sample of 145 female breast cancer survivors. Based on hierarchical linear modeling, breast cancer survivors reported increased levels of both MVPA and cortisol secretion if they experienced higher (as compared with lower) levels of high-arousal negative affect than their personal average. Furthermore, within-person negative affect was associated with: (a) higher MVPA among participants with high (but not low) goal reengagement capacities; and (b) elevated cortisol secretion among participants with low (but not high) goal reengagement capacities. High-arousal negative affect may exert differing functions among breast cancer survivors in that it can trigger adaptive health behaviors, yet simultaneously elevate diurnal cortisol secretion. In addition, being able to engage in new goals may be a necessary condition for breast cancer survivors to experience the beneficial behavioral effects of high-arousal negative affect, and it may prevent the adverse effect of negative affect on enhanced cortisol output. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

Effects of Sequential Fluoxetine and Gender on Pre-quit Depressive Symptoms, Affect, Craving, and Quit Day Abstinence in Smokers with Elevated Depressive Symptoms: A Growth Curve Modeling Approach

PubMed Central

Minami, Haruka; Kahler, Christopher W.; Bloom, Erika Litvin; Prince, Mark A.; Abrantes, Ana M.; Strong, David R.; Niaura, Raymond; Miller, Ivan W.; Palm Reed, Kathleen M.; Price, Lawrence H.; Brown, Richard A.

2015-01-01

While the important roles of post-quit affect and withdrawal symptoms in the process of smoking cessation have been well established, little is known about the relations between pre-quit affective trajectories and cessation outcome on the target quit date (TQD). This study examined whether a 16-week course of fluoxetine initiated 8 weeks pre-quit (“sequential” fluoxetine) improved TQD abstinence relative to placebo through its effects on pre-quit depressive symptoms, affect (withdrawal-relevant negative affect, general negative affect, and positive affect), and craving to smoke among 206 smokers with elevated depressed symptoms. The moderating effects of gender were also examined. A total of 83 smokers (40%) failed to achieve abstinence on TQD, with no difference between treatment conditions or gender. Overall structural equation models showed that fluoxetine had significant indirect effects on TQD abstinence through changes in pre-quit withdrawal-relevant negative affect and craving, but not depressive symptoms. However, multigroup analyses revealed gender differences. Sequential fluoxetine reduced pre-quit depressive symptoms, withdrawal-relevant negative affect, and craving only among women. Reduction in pre-quit depressive symptoms and craving among women, and withdrawal-relevant negative affect among men was associated with TQD abstinence. Moreover, exploratory analysis showed negative trend-level indirect effects of fluoxetine on TQD abstinence via increased side effects, regardless of gender. This study demonstrated the importance of considering gender when examining treatment efficacy. Identifying ways to further reduce pre-quit depressive symptoms and craving for women and withdrawal-relevant negative affect for men while alleviating side effects may help smokers with elevated depressed symptoms achieve the first smoking cessation milestone. PMID:25089930

Effects of Age on Negative Subsequent Memory Effects Associated with the Encoding of Item and Item–Context Information

PubMed Central

Mattson, Julia T.; Wang, Tracy H.; de Chastelaine, Marianne; Rugg, Michael D.

2014-01-01

It has consistently been reported that “negative” subsequent memory effects—lower study activity for later remembered than later forgotten items—are attenuated in older individuals. The present functional magnetic resonance imaging study investigated whether these findings extend to subsequent memory effects associated with successful encoding of item–context information. Older (n = 25) and young (n = 17) subjects were scanned while making 1 of 2 encoding judgments on a series of pictures. Memory was assessed for the study item and, for items judged old, the item's encoding task. Both memory judgments were made using confidence ratings, permitting item and source memory strength to be unconfounded and source confidence to be equated across age groups. Replicating prior findings, negative item effects in regions of the default mode network in young subjects were reversed in older subjects. Negative source effects, however, were invariant with respect to age and, in both age groups, the magnitude of the effects correlated with source memory performance. It is concluded that negative item effects do not reflect processes necessary for the successful encoding of item–context associations in older subjects. Negative source effects, in contrast, appear to reflect the engagement of processes that are equally important for successful episodic encoding in older and younger individuals. PMID:23904464

Effects of Soldiers’ Deployment on Children’s Academic Performance and Behavioral Health

DTIC Science & Technology

2011-01-01

tests. We found a negative relationship between the cumulative months a parent had deployed and achievement test scores across states (North Carolina...strongest negative relationship with cumulative parental deployment of 1 to 18 months and 19 months or more, and this effect size is larger than...that the negative effect of parental deployment on academic scores is more pronounced on elementary-age children (grades 3–6) than on secondary-age

Defining the neural fulcrum for chronic vagus nerve stimulation: implications for integrated cardiac control.

PubMed

Ardell, Jeffrey L; Nier, Heath; Hammer, Matthew; Southerland, E Marie; Ardell, Christopher L; Beaumont, Eric; KenKnight, Bruce H; Armour, J Andrew

2017-11-15

The evoked cardiac response to bipolar cervical vagus nerve stimulation (VNS) reflects a dynamic interaction between afferent mediated decreases in central parasympathetic drive and suppressive effects evoked by direct stimulation of parasympathetic efferent axons to the heart. The neural fulcrum is defined as the operating point, based on frequency-amplitude-pulse width, where a null heart rate response is reproducibly evoked during the on-phase of VNS. Cardiac control, based on the principal of the neural fulcrum, can be elicited from either vagus. Beta-receptor blockade does not alter the tachycardia phase to low intensity VNS, but can increase the bradycardia to higher intensity VNS. While muscarinic cholinergic blockade prevented the VNS-induced bradycardia, clinically relevant doses of ACE inhibitors, beta-blockade and the funny channel blocker ivabradine did not alter the VNS chronotropic response. While there are qualitative differences in VNS heart control between awake and anaesthetized states, the physiological expression of the neural fulcrum is maintained. Vagus nerve stimulation (VNS) is an emerging therapy for treatment of chronic heart failure and remains a standard of therapy in patients with treatment-resistant epilepsy. The objective of this work was to characterize heart rate (HR) responses (HRRs) during the active phase of chronic VNS over a wide range of stimulation parameters in order to define optimal protocols for bidirectional bioelectronic control of the heart. In normal canines, bipolar electrodes were chronically implanted on the cervical vagosympathetic trunk bilaterally with anode cephalad to cathode (n = 8, 'cardiac' configuration) or with electrode positions reversed (n = 8, 'epilepsy' configuration). In awake state, HRRs were determined for each combination of pulse frequency (2-20 Hz), intensity (0-3.5 mA) and pulse widths (130-750 μs) over 14 months. At low intensities and higher frequency VNS, HR increased during the VNS active phase owing to afferent modulation of parasympathetic central drive. When functional effects of afferent and efferent fibre activation were balanced, a null HRR was evoked (defined as 'neural fulcrum') during which HRR ≈ 0. As intensity increased further, HR was reduced during the active phase of VNS. While qualitatively similar, VNS delivered in the epilepsy configuration resulted in more pronounced HR acceleration and reduced HR deceleration during VNS. At termination, under anaesthesia, transection of the vagi rostral to the stimulation site eliminated the augmenting response to VNS and enhanced the parasympathetic efferent-mediated suppressing effect on electrical and mechanical function of the heart. In conclusion, VNS activates central then peripheral aspects of the cardiac nervous system. VNS control over cardiac function is maintained during chronic therapy. © 2017 The Authors. The Journal of Physiology © 2017 The Physiological Society.

Meta-analysis of the effects of repetitive transcranial magnetic stimulation (rTMS) on negative and positive symptoms in schizophrenia

PubMed Central

Freitas, Catarina; Fregni, Felipe; Pascual-Leone, Alvaro

2009-01-01

Background A growing body of evidence suggests that repetitive transcranial magnetic stimulation (rTMS) can alleviate negative and positive symptoms of refractory schizophrenia. However, trials to date have been small and results are mixed. Methods We performed meta-analyses of all prospective studies of the therapeutic application of rTMS in refractory schizophrenia assessing the effects of high-frequency rTMS to the left dorsolateral prefrontal cortex (DLPFC) to treat negative symptoms, and low-frequency rTMS to the left temporo-parietal cortex (TPC) to treat auditory hallucinations (AH) and overall positive symptoms. Results When analyzing controlled (active arms) and uncontrolled studies together, the effect sizes showed significant and moderate effects of rTMS on negative and positive symptoms (based on PANSS-N or SANS, and PANSS-P or SAPS, respectively). However, the analysis for the sham-controlled studies revealed a small non-significant effect size for negative (0.27, p=0.417) and for positive symptoms (0.17, p=0.129). When specifically analyzing AH (based on AHRS, HCS or SAH), the effect size for the sham-controlled studies was large and significant (1.04; p=0.002). Conclusions These meta-analyses support the need for further controlled, larger trials to assess the clinical efficacy of rTMS on negative and positive symptoms of schizophrenia, while suggesting the need for exploration for alternative stimulation protocols. PMID:19138833

Negative ions of polyatomic molecules.

PubMed Central

Christophorou, L G

1980-01-01

In this paper general concepts relating to, and recent advances in, the study of negative ions of polyatomic molecules area discussed with emphasis on halocarbons. The topics dealt with in the paper are as follows: basic electron attachment processes, modes of electron capture by molecules, short-lived transient negative ions, dissociative electron attachment to ground-state molecules and to "hot" molecules (effects of temperature on electron attachment), parent negative ions, effect of density, nature, and state of the medium on electron attachment, electron attachment to electronically excited molecules, the binding of attached electrons to molecules ("electron affinity"), and the basic and the applied significance of negative-ion studies. PMID:7428744

Negative emotion elicited in high school students enhances consolidation of item memory, but not source memory.

PubMed

Wang, Bo

2015-05-01

The study examined the effect of negative emotion on consolidation of both item and source memory. Participants learned words read by either a male or female. Then they watched either a negative or a neutral video clip. Memory tests were carried out either 25min or 24h after learning. The study yielded the following findings. First, negative emotion enhanced consolidation of item memory as measured by recognition memory in the 25-min delay, and enhanced consolidation of item memory as measured by free recall in both the 25-min and the 24-h delay. Second, negative emotion had little effect on consolidation of source memory, either in the 25-min or the 24-h delay. These findings provide evidence for the differential effects of negative emotion on item memory and source memory and have implications for using emotion as a strategy to intervene memory consolidation. Copyright © 2015 Elsevier Inc. All rights reserved.

'Help me! I'm old!' How negative aging stereotypes create dependency among older adults.

PubMed

Coudin, Genevieve; Alexopoulos, Theodore

2010-07-01

This study examined the effects of negative aging stereotypes on self-reported loneliness, risk-taking, subjective health, and help-seeking behavior in a French sample of older adults. The aim of this study was to show the detrimental effects of negative aging stereotypes on older adults' self-evaluations and behaviors, therefore contributing to the explanations of the iatrogenic effect of social environments that increase dependency (e.g., health care institutions). In the first experiment conducted on 57 older adults, we explored the effects of positive, neutral, or negative stereotype activation on the feeling of loneliness and risk taking decision. The second experiment (n = 60) examined the impact of stereotype activation on subjective health, self-reported extraversion as well as on a genuine help-seeking behavior, by allowing participants to ask for the experimenter's help while completing a task. As predicted, negative stereotype activation resulted in lower levels of risk taking, subjective health and extraversion, and in higher feelings of loneliness and a more frequent help-seeking behavior. These findings suggest that the mere activation of negative stereotypes can have broad and deleterious effects on older individuals' self-evaluation and functioning, which in turn may contribute to the often observed dependency among older people.

Neural evidence for description dependent reward processing in the framing effect

PubMed Central

Yu, Rongjun; Zhang, Ping

2014-01-01

Human decision making can be influenced by emotionally valenced contexts, known as the framing effect. We used event-related brain potentials to investigate how framing influences the encoding of reward. We found that the feedback related negativity (FRN), which indexes the “worse than expected” negative prediction error in the anterior cingulate cortex (ACC), was more negative for the negative frame than for the positive frame in the win domain. Consistent with previous findings that the FRN is not sensitive to “better than expected” positive prediction error, the FRN did not differentiate the positive and negative frame in the loss domain. Our results provide neural evidence that the description invariance principle which states that reward representation and decision making are not influenced by how options are presented is violated in the framing effect. PMID:24733998

Novel stimuli are negative stimuli: evidence that negative affect is reduced in the mere exposure effect.

PubMed

Robinson, Brent M; Elias, Lorin J

2005-04-01

Repeated exposure of a nonreinforced stimulus results in an increased preference for that stimulus, the mere exposure effect. The present study repeatedly presented positive, negative, and neutrally affective faces to 48 participants while they made judgments about the emotional expression. Participants then rated the likeability of novel neutrally expressive faces and some of these previously presented faces, this time in their neutral expression. Faces originally presented as happy were rated as the most likeable, followed by faces originally presented as neutral. Negative and novel faces were not rated significantly differently from each other. These findings support the notion that the increase in preference towards repeatedly presented stimuli is the result of the reduction in negative affect, consistent with the modified two-factor uncertainty-reduction model and classical conditioning model of the mere exposure effect.

Similarity to the Self Affects Memory for Impressions of Others in Younger and Older Adults

PubMed Central

Park, Jung M.; Gutchess, Angela H.

2015-01-01

Objectives. Similarity to the self has been shown to affect memory for impressions in younger adults, suggesting a self-reference effect in person memory. Because older adults show comparable self-reference effects, but prioritize memory for positive over negative information relative to young adults, we examined age differences in self-similarity effects on memory for positive and negative impressions. Method. Younger and older adults formed positive and negative impressions of others differing in the degree of similarity to the self (high, medium, low). Results. For positive impressions, both groups showed enhanced memory for self-similar others relative to dissimilar others, whereas for negative impressions, memory was poorer for those similar to the self. When collapsed across similarity to the self, younger adults remembered negative impressions better than older adults, but interestingly, older adults exhibited a trend for better memory for the positive impressions. Discussion. Results suggest that self-reference effects in impression memory are preserved with age and that older adults exhibit positivity effects in person memory consistent with previous findings. PMID:24389124

Positive messaging promotes walking in older adults.

PubMed

Notthoff, Nanna; Carstensen, Laura L

2014-06-01

Walking is among the most cost-effective and accessible means of exercise. Mounting evidence suggests that walking may help to maintain physical and cognitive independence in old age by preventing a variety of health problems. However, older Americans fall far short of meeting the daily recommendations for walking. In 2 studies, we examined whether considering older adults' preferential attention to positive information may effectively enhance interventions aimed at promoting walking. In Study 1, we compared the effectiveness of positive, negative, and neutral messages to encourage walking (as measured with pedometers). Older adults who were informed about the benefits of walking walked more than those who were informed about the negative consequences of failing to walk, whereas younger adults were unaffected by framing valence. In Study 2, we examined within-person change in walking in older adults in response to positively- or negatively-framed messages over a 28-day period. Once again, positively-framed messages more effectively promoted walking than negatively-framed messages, and the effect was sustained across the intervention period. Together, these studies suggest that consideration of age-related changes in preferences for positive and negative information may inform the design of effective interventions to promote healthy lifestyles. Future research is needed to examine the mechanisms underlying the greater effectiveness of positively- as opposed to negatively-framed messages and the generalizability of findings to other intervention targets and other subpopulations of older adults. PsycINFO Database Record (c) 2014 APA, all rights reserved.

Sphingosine mediates the immediate negative inotropic effects of tumor necrosis factor-alpha in the adult mammalian cardiac myocyte.

PubMed

Oral, H; Dorn, G W; Mann, D L

1997-02-21

To determine whether activation of the neutral sphingomyelinase pathway was responsible for the immediate (<30 min) negative inotropic effects of tumor necrosis factor-alpha (TNF-alpha), we examined sphingosine levels in diluent and TNF-alpha-stimulated cardiac myocytes. TNF-alpha stimulation of adult feline cardiac myocytes provoked a rapid (<15 min) increase in the hydrolysis of [14C]sphingomyelin in cell-free extracts, as well as an increase in ceramide mass, consistent with cytokine-induced activation of the neutral sphingomyelinase pathway. High performance liquid chromatographic analysis of lipid extracts from TNF-alpha-stimulated cardiac myocytes showed that TNF-alpha stimulation produced a rapid (<30 min) increase in free sphingosine levels. Moreover, exogenous D-sphingosine mimicked the effects of TNF-alpha on intracellular calcium homeostasis, as well as the negative inotropic effects of TNF-alpha in isolated contracting myocytes; time course studies showed that exogenous D-sphingosine produced abnormalities in cell shortening that were maximal at 5 min. Finally, blocking sphingosine production using an inhibitor of ceramidase, n-oleoylethanolamine, completely abrogated the negative inotropic effects of TNF-alpha in isolated contracting cardiac myocytes. Additional studies employing biologically active ceramide analogs and sphingosine 1-phosphate suggested that neither the immediate precursor of sphingosine nor the immediate metabolite of sphingosine, respectively, were likely to be responsible for the immediate negative inotropic effects of TNF-alpha. Thus, these studies suggest that sphingosine mediates the immediate negative inotropic effects of TNF-alpha in isolated cardiac myocytes.

Suicide and war: the mediating effects of negative mood, posttraumatic stress disorder symptoms, and social support among army National Guard soldiers.

PubMed

Griffith, James

2012-08-01

The mediating effects of posttraumatic stress disorder (PTSD) symptoms, negative mood, and social support on the relationship of war experiences to suicidality were examined. The research literature suggested a sequence among study scales representing these constructs, which was then tested on survey data obtained from a sample of National Guard soldiers (N=4,546). Results from structural equation modeling suggested that war experiences may precipitate a sequence of psychological consequences leading to suicidality. However, suicidality may be an enduring behavioral health condition. War experiences showed no direct effects on postdeployment suicidality, rather its effect was indirect through PTSD symptoms and negative mood. War experiences were, however, predictive of PTSD symptoms, as would be expected. PSTD symptoms showed no direct effect on postdeployment suicidality, but showed indirect effects through negative mood. Results also suggested that suicidality is relatively persistent, at least during deployment and postdeployment. The percentage of those at risk for suicide was low both during and after deployment, with little association between suicidality and time since returning from deployment. Additionally, few soldiers were initially nonsuicidal and then reported such symptoms at postdeployment. Implications of relationships of both negative mood and combat trauma to suicidality are discussed, as well as possible mediating effects of both personal dispositions and social support on relationships of war experiences to PTSD, negative mood, and suicidality. © 2012 The American Association of Suicidology.

Sibship size and educational attainment. A joint test of the Confluence Model and the Resource Dilution Hypothesis

PubMed Central

Jæger, Mads Meier

2012-01-01

Studies on family background often explain the negative effect of sibship size on educational attainment by one of two theories: the Confluence Model (CM) or the Resource Dilution Hypothesis (RDH). However, as both theories – for substantively different reasons – predict that sibship size should have a negative effect on educational attainment most studies cannot distinguish empirically between the CM and the RDH. In this paper, I use the different theoretical predictions in the CM and RDH on the role of cognitive ability as a partial or complete mediator of the effect of sibship size to distinguish the two theories and to identify a unique RDH effect on educational attainment. Using sibling data from the Wisconsin Longitudinal Study (WLS) and a random effect Instrumental Variable model I find that, in addition to a negative effect on cognitive ability, sibship size also has a strong negative effect on educational attainment which is uniquely explained by the RDH. PMID:22468016

Relationships Between Stress, Negative Emotions, Resilience, and Smoking: Testing a Moderated Mediation Model.

PubMed

Wang, Yan; Chen, Xinguang; Gong, Jie; Yan, Yaqiong

2016-01-01

More effective tobacco prevention and cessation programs require in-depth understanding of the mechanism by which multiple factors interact with each other to affect smoking behaviors. Stress has long been recognized as a risk factor for smoking. However, the underlying mediation and moderation mechanisms are far from clear. The purpose of this study was to examine the role of negative emotions in mediating the link between stress and smoking and whether this indirect link was modified by resilience. Survey data were collected using audio computer-assisted self-interview (ACASI) from a large random sample of urban residents (n = 1249, mean age = 35.1, 45.3% male) in Wuhan, China. Perceived stress, negative emotions (anxiety, depression), resilience were measured with reliable instruments also validated in China. Self-reported smoking was validated with exhaled carbon monoxide. Mediation analysis indicated that two negative emotions fully mediated the link between stress and intensity of smoking (assessed by number of cigarettes smoked per day, effect =.082 for anxiety and.083 for depression) and nicotine dependence (assessed by DSM-IV standard, effect =.134 for anxiety and.207 for depression). Moderated mediation analysis demonstrated that the mediation effects of negative emotions were negatively associated with resilience. Results suggest resilience interacts with stress and negative emotions to affect the risk of tobacco use and nicotine dependence among Chinese adults. Further research with longitudinal data is needed to verify the findings of this study and to estimate the effect size of resilience in tobacco intervention and cessation programs.

Positive, negative, or all relative? Evaluative conditioning of ambivalence.

PubMed

Glaser, Tina; Woud, Marcella L; Labib Iskander, Michael; Schmalenstroth, Vera; Vo, Thuy My

2018-04-01

In evaluative conditioning (EC), the pairing of a positively or negatively valenced stimulus (US) with a neutral stimulus (CS) leads to a corresponding change in liking of the CS. EC research so far has concentrated on using unambiguously positive or negative USs. However, attitude objects are often ambivalent, i.e., can simultaneously possess positive and negative features. The present research investigated whether ambivalence can be evaluatively conditioned and whether contingency awareness moderates this effect. In two studies, positive, negative, neutral, and ambivalent USs were paired with affectively neutral CSs. Results showed standard EC effects that were moderated by contingency awareness. Most interestingly, EC effects were also obtained for the ambivalent USs, indicating that ambivalence can indeed be conditioned. However, contingency awareness seemed to play a lesser role in ambivalence conditioning. Ambivalence EC effects were obtained on subjective and objective direct measures of ambivalence as well as on a more indirect measure. Copyright © 2018 Elsevier B.V. All rights reserved.

A social relations model of observed family negativity and positivity using a genetically informative sample.

PubMed

Rasbash, Jon; Jenkins, Jennifer; O'Connor, Thomas G; Tackett, Jennifer; Reiss, David

2011-03-01

The goal of this study was to investigate individual and relationship influences on expressions of negativity and positivity in families. Parents and adolescents were observed in a round-robin design in a sample of 687 families. Data were analyzed using a multilevel social relations model. In addition, genetic contributions were estimated for actor effects. Children showed higher mean levels of negativity and lower mean levels of positivity as actors than did parents. Mothers were found to express and elicit higher mean levels of positivity and negativity than fathers. Actor effects were much stronger than partner effects, accounting for between 18%-39% of the variance depending on the actor and the outcome. Genetic (35%) and shared environmental (19%) influences explained a substantial proportion of the actor effect variance for negativity. Dyadic reciprocities were lowest in dyads with a high power differential (i.e., parent-child dyads) and highest for dyads with equal power (sibling and marital dyads). (c) 2011 APA, all rights reserved

Disability and Activity-related Emotion in Later Life: Are Effects Buffered by Intimate Relationship Support and Strain?

PubMed

Carr, Deborah; Cornman, Jennifer C; Freedman, Vicki A

2017-09-01

We use daily diary data from the Disability and Use of Time supplement to the 2013 Panel Study of Income Dynamics ( n = 1,162) to evaluate (1) the extent to which marital/partner support and strain moderate the effects of disability on five activity-related emotions (happiness, calm, sadness, frustration, worry) and overall negative and positive emotion among older married, cohabiting, and dating persons and (2) whether such patterns differ significantly by gender. Marital support buffers against negative emotions and increases feelings of calm among severely impaired women. By contrast, support intensifies negative emotions and decreases feelings of calm among severely impaired men. Relationship strain also intensifies the effect of severe impairment on men's frustration, sadness, worry, and negative mood but has negligible effects on the negative emotions of men with low impairment and women. Frequent support and criticism may threaten highly impaired older men's sense of autonomy and emotional well-being.

The Costs of Suppressing Negative Emotions and Amplifying Positive Emotions During Parental Caregiving.

PubMed

Le, Bonnie M; Impett, Emily A

2016-03-01

How do parents feel when they regulate their emotional expressions in ways that are incongruent with their genuine feelings? In an experimental study, parents reported experiencing lower authenticity, emotional well-being, relationship quality, and responsiveness to their children's needs when they recalled caregiving experiences in which they suppressed negative emotions and amplified positive emotions, relative to a control condition. In a 10-day daily experience study, parents tended to use both regulation strategies simultaneously. In addition, assessing their unique effects indicated that positive emotion amplification, but not negative emotion suppression, had an indirect effect on parental outcomes via authenticity, with negative emotion suppression no longer being costly. This indirect effect was dampened when accounting for care difficulty. In both studies, effects were independent of a child's mood. The current results suggest that parents' attempts to suppress negative and amplify positive emotions during child care can detract from their well-being and high-quality parent-child bonds. © 2016 by the Society for Personality and Social Psychology, Inc.

Negative-mass mitigation of Coulomb repulsion for terahertz undulator radiation of electron bunches

DOE Office of Scientific and Technical Information (OSTI.GOV)

Balal, N.; Magory, E.; Bandurkin, I. V.

2015-10-19

It is proposed to utilize the effect of negative mass for stabilization of the effective axial size of very dense and short electron bunches produced by photo-injector guns by using combined undulator and strong uniform magnetic fields. It has been shown that in the “abnormal” regime, an increase in the electron energy leads to a decrease in the axial velocity of the electron; due to the negative-mass effect, the Coulomb repulsion of electrons leads to their attraction and formation of a fairly stable and compact bunch “nucleus.” An undulator with a strong uniform magnetic field providing the negative-mass effect ismore » designed for an experimental source of terahertz radiation. The use of the negative-mass regime in this experiment should result in a long-pulse coherent spontaneous undulator emission from a short dense moderately relativistic (5.5 MeV) photo-injector electron bunch with a high (up to 20%) efficiency and a narrow frequency spectrum.« less

Rhesus factor modulation of effects of smoking and age on psychomotor performance, intelligence, personality profile, and health in Czech soldiers.

PubMed

Flegr, Jaroslav; Geryk, Jan; Volný, Jindra; Klose, Jiří; Cernochová, Dana

2012-01-01

Rhesus-positive and rhesus-negative persons differ in the presence-absence of highly immunogenic RhD protein on the erythrocyte membrane. This protein is a component of NH(3) or CO(2) pump whose physiological role is unknown. Several recent studies have shown that RhD positivity protects against effects of latent toxoplasmosis on motor performance and personality. It is not known, however, whether the RhD phenotype modifies exclusively the response of the body to toxoplasmosis or whether it also influences effects of other factors. In the present cohort study, we searched for the effects of age and smoking on performance, intelligence, personality and self-estimated health and wellness in about 3800 draftees. We found that the positive effect of age on performance and intelligence was stronger in RhD-positive soldiers, while the negative effect of smoking on performance and intelligence was of similar size regardless of the RhD phenotype. The effect of age on four Cattell's personality factors, i.e., dominance (E), radicalism (Q(1)), self-sentiment integration (Q(3)), and ergic tension (Q(4)), and on Cloninger's factor reward dependency (RD) was stronger for RhD-negative than RhD-positive subjects, while the effect of smoking on the number of viral and bacterial diseases was about three times stronger for RhD-negative than RhD-positive subjects. RhD phenotype modulates the influence not only of latent toxoplasmosis, but also of at least two other potentially detrimental factors, age and smoking, on human behavior and physiology. The negative effect of smoking on health (estimated on the basis of the self-rated number of common viral and bacterial diseases in the past year) was much stronger in RhD-negative than RhD-positive subjects. It is critically needed to confirm the differences in health response to smoking between RhD-positive and RhD-negative subjects by objective medical examination in future studies.

Personality, negative affect coping, and drinking alone: a structural equation modeling approach to examine correlates of adolescent solitary drinking

PubMed Central

Creswell, Kasey G.; Chung, Tammy; Wright, Aidan G. C.; Clark, Duncan B.; Black, Jessica J.; Martin, Christopher S.

2015-01-01

Aims This study examined the personality traits of negative emotionality and constraint and the ability to resist drinking during negative affective states as correlates of solitary drinking in adolescence. We hypothesized that higher levels of negative emotionality and lower levels of constraint would predict solitary drinking and that these relationships would be mediated by the ability to resist drinking in response to negative emotions. Design Structural equation modeling was used to fit a path model from the personality traits of negative emotionality and constraint to solitary drinking status through intermediate effects on the ability to resist drinking during negative emotions using cross-sectional data. Setting Clinical and community settings in Pennsylvania, USA. Participants The sample included 761 adolescent drinkers (mean age = 17.1). Measurements Adolescents completed the Lifetime Drinking History, the Multidimensional Personality Questionnaire, the Constructive Thinking Inventory and the Situational Confidence Questionnaire. Findings The path model provided a good fit to the data. The association between trait negative emotionality and solitary drinking was fully mediated by adolescents' ability to resist drinking during negative affective states (b = 0.05, P = 0.01). In contrast, constraint had a direct effect on solitary drinking (odds ratio (OR) = 0.79, b = –0.23, P<0.01), as well as an indirect effect through the ability to resist drinking during negative affective states (b = –0.03, P = 0.02). Conclusions The ability to resist drinking while experiencing negative feelings or emotions may be an important underlying mechanism linking trait negative emotionality (a tendency toward depression, anxiety and poor reaction to stress) and constraint (lack of impulsiveness) to adolescent solitary drinking. PMID:25664806

Personality, negative affect coping, and drinking alone: a structural equation modeling approach to examine correlates of adolescent solitary drinking.

PubMed

Creswell, Kasey G; Chung, Tammy; Wright, Aidan G C; Clark, Duncan B; Black, Jessica J; Martin, Christopher S

2015-05-01

This study examined the personality traits of negative emotionality and constraint and the ability to resist drinking during negative affective states as correlates of solitary drinking in adolescence. We hypothesized that higher levels of negative emotionality and lower levels of constraint would predict solitary drinking and that these relationships would be mediated by the ability to resist drinking in response to negative emotions. Structural equation modeling was used to fit a path model from the personality traits of negative emotionality and constraint to solitary drinking status through intermediate effects on the ability to resist drinking during negative emotions using cross-sectional data. Clinical and community settings in Pennsylvania, USA. The sample included 761 adolescent drinkers (mean age = 17.1). Adolescents completed the Lifetime Drinking History, the Multidimensional Personality Questionnaire, the Constructive Thinking Inventory and the Situational Confidence Questionnaire. The path model provided a good fit to the data. The association between trait negative emotionality and solitary drinking was fully mediated by adolescents' ability to resist drinking during negative affective states (b = 0.05, P = 0.01). In contrast, constraint had a direct effect on solitary drinking (odds ratio (OR) = 0.79, b = -0.23, P<0.01), as well as an indirect effect through the ability to resist drinking during negative affective states (b = -0.03, P = 0.02). The ability to resist drinking while experiencing negative feelings or emotions may be an important underlying mechanism linking trait negative emotionality (a tendency toward depression, anxiety and poor reaction to stress) and constraint (lack of impulsiveness) to adolescent solitary drinking. © 2015 Society for the Study of Addiction.

Intelligence, Education, and Facets of Job Satisfaction.

ERIC Educational Resources Information Center

Ganzach, Yoav

2003-01-01

Analysis of two sets of National Longitudinal Survey data found that intelligence had a strong negative effect on intrinsic satisfaction, little effect on pay satisfaction, and positive association with desired job complexity, not expected pay. Education had a strong negative effect on pay satisfaction, little effect on intrinsic satisfaction, and…

Effects of Online Comments on Smokers’ Perception of Anti-Smoking Public Service Announcements

PubMed Central

Shi, Rui; Messaris, Paul; Cappella, Joseph N.

2014-01-01

On YouTube anti-smoking PSAs are widely viewed and uploaded; they also receive extensive commentary by viewers. This study examined whether such evaluative comments with or without uncivil expressions influence evaluations by subsequent viewers. Results showed PSAs with positive (i.e. anti-smoking) comments were perceived by smokers as more effective than PSAs with negative (pro smoking) comments. Smokers in the no comment condition gave the highest perceived effectiveness score to PSAs. Smokers’ readiness to quit smoking moderated the effect of comments on PSA evaluation. Smokers reading negative uncivil comments reported more negative attitude toward quitting and a lower level of perceived risk of smoking than those reading negative civil comments but positive civil and positive uncivil comments didn't elicit different responses. PMID:25561825

Effects of Online Comments on Smokers' Perception of Anti-Smoking Public Service Announcements.

PubMed

Shi, Rui; Messaris, Paul; Cappella, Joseph N

2014-07-01

On YouTube anti-smoking PSAs are widely viewed and uploaded; they also receive extensive commentary by viewers. This study examined whether such evaluative comments with or without uncivil expressions influence evaluations by subsequent viewers. Results showed PSAs with positive (i.e. anti-smoking) comments were perceived by smokers as more effective than PSAs with negative (pro smoking) comments. Smokers in the no comment condition gave the highest perceived effectiveness score to PSAs. Smokers' readiness to quit smoking moderated the effect of comments on PSA evaluation. Smokers reading negative uncivil comments reported more negative attitude toward quitting and a lower level of perceived risk of smoking than those reading negative civil comments but positive civil and positive uncivil comments didn't elicit different responses.

I think therefore I om: cognitive distortions and coping style as mediators for the effects of mindfulness meditation on anxiety, positive and negative affect, and hope.

PubMed

Sears, Sharon; Kraus, Sue

2009-06-01

This study examined cognitive distortions and coping styles as potential mediators for the effects of mindfulness meditation on anxiety, negative affect, positive affect, and hope in college students. Our pre- and postintervention design had four conditions: control, brief meditation focused on attention, brief meditation focused on loving kindness, and longer meditation combining both attentional and loving kindness aspects of mindfulness. Each group met weekly over the course of a semester. Longer combined meditation significantly reduced anxiety and negative affect and increased hope. Changes in cognitive distortions mediated intervention effects for anxiety, negative affect, and hope. Further research is needed to determine differential effects of types of meditation. Copyright 2009 Wiley Periodicals, Inc.

Neural circuits associated with positive and negative self-appraisal.

PubMed

Brühl, A B; Rufer, M; Kaffenberger, T; Baur, V; Herwig, U

2014-04-18

Self-worth is particularly influenced by self-appraisal, which is negatively biased in many psychiatric disorders. Positive and negative self-appraisals also shape current emotional states or even evoke defensive reactions, when they are incongruent with a subject's current state. Prior studies have mainly used externally given evaluative appraisals. In this study, 30 subjects used individual negative and positive self-appraisals during functional magnetic resonance imaging. We additionally investigated the effects of such self-appraisals onto the subsequent perception of photos of the individual subjects. Both self-appraisal conditions activated dorsomedial and dorsolateral prefrontal cortex compared to the neutral condition. Positive self-appraisal evoked stronger activity than negative self-appraisal in the amygdala, ventral striatum and anterior cingulate cortex, whereas negative self-appraisal was associated with increased activity in the occipital regions. Positive self-appraisal had no effect on the perception of a photo of oneself, whereas negative appraisal increased activity in the anterior insula and parietal regions. Overall, positive self-appraisal activated more emotion-related brain regions, whereas negative self-appraisal had a relatively stronger influence on perception-related brain activity. These findings could on the one hand explain the effect of negative self-appraisal on the behavior in the real world and on the other hand support a stronger focus of psychotherapy on enhancing positive self-appraisals. Copyright © 2014 IBRO. Published by Elsevier Ltd. All rights reserved.

Negative Academic Emotion and Psychological Well-being in Chinese Rural-to-Urban Migrant Adolescents: Examining the Moderating Role of Cognitive Reappraisal

PubMed Central

Wang, Daoyang; Li, Shuting; Hu, Mingming; Dong, Dan; Tao, Sha

2017-01-01

The study aimed to explore the relationship among negative academic emotions (e.g., anxiety, shame, anger, boredom, hopelessness, disappointment, and hatred), psychological well-being (including life vitality, health concern, altruism commitment, self-value, friendly relationship, and personal development), and cognitive reappraisal in rural-to-urban migrant adolescents in China. Specifically, it was hypothesized that the relationship between psychological well-being and negative academic emotions is moderated by cognitive reappraisal. A total of 311 migrant adolescents aged 14–20 years were selected, including 132 boys and 179 girls. Results of a regression analysis showed that cognitive reappraisal (positive) and negative academic emotions were significant predictors of psychological well-being. The interaction effect between cognitive reappraisal and negative academic emotion was also a significant predictor of psychological well-being. In the simple slope analysis the group with a below average cognitive reappraisal score the negative academic emotions were associated with lower psychological well-being, whereas in the group with above average cognitive reappraisal the effect of negative academic emotions on psychological well-being was not significant. However, for those with a cognitive reappraisal score of 1 standard deviation above the average, the effect of negative academic emotions on psychological well-being was not significant. These results suggest that cognitive reappraisal was a significant moderator in the relationship between negative academic emotion and psychological well-being. PMID:28824495

Negative Academic Emotion and Psychological Well-being in Chinese Rural-to-Urban Migrant Adolescents: Examining the Moderating Role of Cognitive Reappraisal.

PubMed

Wang, Daoyang; Li, Shuting; Hu, Mingming; Dong, Dan; Tao, Sha

2017-01-01

The study aimed to explore the relationship among negative academic emotions (e.g., anxiety, shame, anger, boredom, hopelessness, disappointment, and hatred), psychological well-being (including life vitality, health concern, altruism commitment, self-value, friendly relationship, and personal development), and cognitive reappraisal in rural-to-urban migrant adolescents in China. Specifically, it was hypothesized that the relationship between psychological well-being and negative academic emotions is moderated by cognitive reappraisal. A total of 311 migrant adolescents aged 14-20 years were selected, including 132 boys and 179 girls. Results of a regression analysis showed that cognitive reappraisal (positive) and negative academic emotions were significant predictors of psychological well-being. The interaction effect between cognitive reappraisal and negative academic emotion was also a significant predictor of psychological well-being. In the simple slope analysis the group with a below average cognitive reappraisal score the negative academic emotions were associated with lower psychological well-being, whereas in the group with above average cognitive reappraisal the effect of negative academic emotions on psychological well-being was not significant. However, for those with a cognitive reappraisal score of 1 standard deviation above the average, the effect of negative academic emotions on psychological well-being was not significant. These results suggest that cognitive reappraisal was a significant moderator in the relationship between negative academic emotion and psychological well-being.

Negative health system effects of Global Fund's investments in AIDS, tuberculosis and malaria from 2002 to 2009: systematic review.

PubMed

Car, Josip; Paljärvi, Tapio; Car, Mate; Kazeem, Ayodele; Majeed, Azeem; Atun, Rifat

2012-10-01

By using the Global Fund as a case example, we aim to critically evaluate the evidence generated from 2002 to 2009 for potential negative health system effects of Global Health Initiatives (GHI). Systematic review of research literature. Developing Countries. All interventions potentially affecting health systems that were funded by the Global Fund. Negative health system effects of Global Fund investments as reported by study authors. We identified 24 studies commenting on adverse effects on health systems arising from Global Fund investments. Sixteen were quantitative studies, six were qualitative and two used both quantitative and qualitative methods, but none explicitly stated that the studies were originally designed to capture or to assess health system effects (positive or negative). Only seemingly anecdotal evidence or authors' perceptions/interpretations of circumstances could be extracted from the included studies. This study shows that much of the currently available evidence generated between 2002 and 2009 on GHIs potential negative health system effects is not of the quality expected or needed to best serve the academic or broader community. The majority of the reviewed research did not fulfil the requirements of rigorous scientific evidence.

The effectiveness of different approaches to media literacy in modifying adolescents' responses to alcohol.

PubMed

Chen, Yi-Chun Yvonnes

2013-01-01

Fearing the negative effect that alcohol advertising might have on adolescents' receptiveness to the consumption of alcohol, health educators have used media literacy as an effective strategy to mitigate the effect of these messages in the media. The present study applied parental mediation to the design and evaluations of a media literacy curriculum that targets alcohol decision-making processes illustrated in the message interpretation process model. The authors conducted a pretest-posttest quasi-experiment of 171 adolescents to examine the effect of a negative evaluative approach and a balanced evaluative approach (a combination of negative and positive evaluative strategies) to media literacy on modifying adolescents' responses to alcohol messages. Results showed that different media literacy approaches had varying degrees of effectiveness on adolescent boys and girls. After receiving a negative media literacy lesson, adolescent boys regarded television characters as less realistic and believed that drinking alcohol had negative consequences. In contrast, adolescent girls benefited more from a balanced evaluative approach as their media skepticism attitude was enhanced. Results suggest that health educators should choose tailored pedagogical approaches that are based on gender to improve decision making regarding alcohol consumption.

An African grassland responds similarly to long-term fertilization to the Park Grass experiment.

PubMed

Ward, David; Kirkman, Kevin; Tsvuura, Zivanai

2017-01-01

We compared the results of a long-term (65 years) experiment in a South African grassland with the world's longest-running ecological experiment, the Park Grass study at Rothamsted, U.K. The climate is warm and humid in South Africa and cool and temperate in England. The African grassland has been fertilized with two forms of nitrogen applied at four levels, phosphorus and lime in a crossed design in 96 plots. In 1951, about 84% of plant cover consisted of Themeda triandra, Tristachya leucothrix and Setaria nigrirostris. Currently, the dominant species are Panicum maximum, Setaria sphacelata and Eragrostis curvula, making up 71% of total biomass. As in the Park Grass experiment, we found a significant (additive) interaction effect on ANPP of nitrogen and phosphorus, and a (marginally significant) negative correlation between ANPP and species richness. Unlike the Park Grass experiment, there was no correlation between ANPP and species richness when pH was included as a covariate. There was also a significant negative effect of nitrogen amount and nitrogen form and a positive effect of lime on species richness and species diversity. Soil pH had an important effect on species richness. Liming was insufficient to balance the negative effects on species richness of nitrogen fertilization. There was a significant effect of pH on biomass of three abundant species. There were also significant effects of light on the biomass of four species, with only Panicum maximum having a negative response to light. In all of the abundant species, adding total species richness and ANPP to the model increased the amount of variance explained. The biomass of Eragrostis curvula and P. maximum were negatively correlated with species richness while three other abundant species increased with species richness, suggesting that competition and facilitation were active. Consistent with the results from the Park Grass and other long-term fertilization experiments of grasslands, we found a positive effect of soil pH and a negative effect of nitrogen amount on species richness, a more acutely negative effect on species richness of acidic ammonium sulphate fertilizer than limestone ammonium nitrate, a negative relationship between species richness and biomass, and a positive effect on species richness of lime interacting with nitrogen.

Negative Capacitance in BaTiO3/BiFeO3 Bilayer Capacitors.

PubMed

Hou, Ya-Fei; Li, Wei-Li; Zhang, Tian-Dong; Yu, Yang; Han, Ren-Lu; Fei, Wei-Dong

2016-08-31

Negative capacitances provide an approach to reduce heat generations in field-effect transistors during the switch processes, which contributes to further miniaturization of the conventional integrated circuits. Although there are many studies about negative capacitances using ferroelectric materials, the direct observation of stable ferroelectric negative capacitances has rarely been reported. Here, we put forward a dc bias assistant model in bilayer capacitors, where one ferroelectric layer with large dielectric constant and the other ferroelectric layer with small dielectric constant are needed. Negative capacitances can be obtained when external dc bias electric fields are larger than a critical value. Based on the model, BaTiO3/BiFeO3 bilayer capacitors are chosen as study objects, and negative capacitances are observed directly. Additionally, the upward self-polarization effect in the ferroelectric layer reduces the critical electric field, which may provide a method for realizing zero and/or small dc bias assistant negative capacitances.

Helping employees sleep well: Effects of cognitive behavioral therapy for insomnia on work outcomes.

PubMed

Barnes, Christopher M; Miller, Jared A; Bostock, Sophie

2017-01-01

Drawing from recent research advances indicating the harmful effects of insomnia on negative affect, job satisfaction, self-control, organizational citizenship behavior, and interpersonal deviance, we hypothesized that treating insomnia with Internet based cognitive behavior therapy for insomnia would lead to improvements in these outcomes. In a field experiment with a randomized wait-list control group, we found that treatment had a beneficial direct effect on negative affect, job satisfaction, and self-control. Moreover, the effect of treatment on job satisfaction was mediated by negative affect. We were not able to detect a direct effect of treatment on organizational citizenship behavior or interpersonal deviance. However, treatment had a beneficial indirect effect on organizational citizenship behavior through the mediators of negative affect and job satisfaction, and a beneficial indirect effect on interpersonal deviance through the mediator of self-control. These results move the applied psychology literature on insomnia beyond simply pointing out problematic effects of employee insomnia to providing evidence of a partial solution to such effects. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

Effect of Art Production on Negative Mood and Anxiety for Adults in Treatment for Substance Abuse

ERIC Educational Resources Information Center

Laurer, Mattye; van der Vennet, Renée

2015-01-01

This study investigated whether art production or viewing and sorting art reproductions would be more effective in reducing negative mood and anxiety for 28 adults with substance use disorders. Participants were randomly assigned to one of two groups and completed pre- and posttest measures of negative mood and anxiety The hypothesis that art…

Child Temperament Moderates Effects of Parent-Child Mutuality on Self-Regulation: A Relationship-Based Path for Emotionally Negative Infants

ERIC Educational Resources Information Center

Kim, Sanghag; Kochanska, Grazyna

2012-01-01

This study examined infants' negative emotionality as moderating the effect of parent-child mutually responsive orientation (MRO) on children's self-regulation (n = 102). Negative emotionality was observed in anger-eliciting episodes and in interactions with parents at 7 months. MRO was coded in naturalistic interactions at 15 months.…

That's not funny! - But it should be: effects of humorous emotion regulation on emotional experience and memory.

PubMed

Kugler, Lisa; Kuhbandner, Christof

2015-01-01

Previous research has shown that humorous reappraisal can reduce elicited negative emotions, suggesting that humor may be a functional strategy to cope with emotionally negative situations. However, the effect of humorous reappraisal on later memory about the emotion-eliciting situation is currently unknown, although this is crucial for more adaptive responding in future situations. To address this issue, we examined the effects of humorous reappraisal on both emotional experience and memory, compared to non-humorous rational reappraisal and a non-reappraisal control condition. Replicating previous findings, humorous reappraisal reduced evoked negative valence and arousal levels very effectively, and the down-regulation of experienced negative emotions was even more pronounced after humorous compared to rational reappraisal. Regarding later memory for emotion-eliciting stimuli, both humorous and rational reappraisal reduced free recall, but recognition memory was unaffected, with memory strength being stronger after humorous than after rational reappraisal. These results indicate that humor seems to be indeed an optimal strategy to cope with negative situations because humor can help us to feel better when confronted with negative stimuli, but still allows us to retrieve stimulus information later when afforded to do so by the presence of appropriate contextual features.

[Effect of workplace bullying on posttraumatic stress disorder in nursing staff].

PubMed

Sun, Y Q; Ge, Y X; Ke, Z W; Li, Y Y; Jin, Q X; Lu, Y F

2018-01-20

Objective: To investigate the relationship between workplace bullying and posttraumatic stress disorder (PTSD) in nursing staff, and to analyze the role of psychological capital between workplace bullying and PTSD. Methods: From December 2014 to June 2015, convenience sampling was used to collect 496 nurses from 5 grade A tertiary hospitals in a province of China. Their workplace bullying, psychological capital, and PTSD status were assessed using the Negative Acts Questionnaire, Psychological Capital Questionnaire, and Posttraumatic Stress Disorder Self-Rating Scale, respectively. The correlation between variables was analyzed using a structural equation model. Results: Among these nurses, the scores of negative acts, psychological capital, and PTSD were 37.15±12.83, 78.81±16.54, and 34.56±12.52, respectively. The score on each dimension of negative acts was positively correlated with that on each dimension of PTSD ( P <0.01) ; the score on each dimension of psychological capital was negatively correlated with that on each dimension of PTSD and negative acts ( P <0.01). Negative acts had a positive predictive effect on PTSD ( β =0.539, P <0.01) , which was reduced after inclusion of psychological capital ( β =0.513, P <0.01). The path coefficient was 0.62 for the effect of negative acts on PTSD, -0.18 for the effect of negative acts on psychological capital, and -0.11 for the effect of psychological capital on PTSD ( P <0.05) . Conclusion: Workplace bullying is a predictive factor for PTSD, and psychological capital plays a mediating role between workplace bullying and PTSD. The manager should reduce workplace bullying to improve the psychological capital in nursing staff and to prevent and reduce PTSD.

Investigation of Dusts Effect and Negative Ion in DC Plasmas by Electric Probes

NASA Astrophysics Data System (ADS)

Oh, Hye Taek; Kang, Inje; Bae, Min-Keun; Park, Insun; Lee, Seunghwa; Jeong, Seojin; Chung, Kyu-Sun

2017-10-01

Dust is typically negatively charged by electron attachment whose thermal velocities are fast compared to that of the heavier ions. The negatively charged particles can play a role of negative ions which affect the quasi-neutrality of background plasma. To investigate effect of metal dusts and negative ion on plasma and materials, metal dusts are injected into background Ar plasma which is generated by tungsten filament using dust dispenser on Cubical Plasma Device (CPD). The CPD has following conditions: size =24x24x24cm3, plasma source =DC filament plasma (ne 1x10x1010, Te 2eV), background gas =Ar, dusts =tungsten powder (diameter 1.89micron). The dust dispenser is developed to quantitate of metal dust by ultrasonic transducer. Electronegative plasmas are generated by adding O2 + Ar plasma to compare negative ion and dust effect. A few grams of micron-sized dusts are placed in the dust dispenser which is located at the upper side of the Cubical Plasma Device. The falling particles by dust dispenser are mainly charged up by the collection of the background plasma. The change in parameters due to negative ion production are characterized by measuring the floating and plasma potential, electron temperature and negative ion density using electric probes.

Do negative emotions expressed during follow-up consultations with adolescent survivors of childhood cancer reflect late effects?

PubMed

Mellblom, Anneli V; Ruud, Ellen; Loge, Jon Håvard; Lie, Hanne C

2017-11-01

To explore whether negative emotions expressed by adolescent cancer survivors during follow-up consultations were associated with potential late effects (persisting disease or treatment-related health problems). We video-recorded 66 follow-up consultations between 10 pediatricians and 66 adolescent survivors of leukemia, lymphoma or stem-cell transplantations. In transcripts of the recordings, we identified utterances coded as both 1) expressions of negative emotions (VR-CoDES), and 2) late effect-related discussions. Principles of thematic content analysis were used to investigate associations between the two. Of the 66 video-recorded consultations, 22 consultations contained 56 (49%) utterances coded as both emotional concerns and discussions of potential late effects. Negative emotions were most commonly associated with late effects such as fatigue ("I'm struggling with not having energy"), psychosocial distress ("When I touch this (scar) I become nauseous"), pain ("I'm wondering how long I am going to have this pain?"), and treatment-related effects on physical appearance ("Am I growing?"). Negative emotions expressed by adolescent cancer survivors during follow-up consultations were frequently associated with potential late effects. These late effects were not the medically most serious ones, but reflected issues affecting the adolescents' daily life. Eliciting and exploring patients' emotional concerns serve as means to obtain clinically relevant information regarding potential late effect and to provide emotional support. Copyright © 2017 Elsevier B.V. All rights reserved.

Testing a model of depression among Thai adolescents.

PubMed

Vatanasin, Duangjai; Thapinta, Darawan; Thompson, Elaine Adams; Thungjaroenkul, Petsunee

2012-11-01

This predictive correlational study was designed to test a comprehensive model of depression for Thai adolescents. This sample included 800 high school students in Chiang Mai, Thailand. Data were collected using self-reported measures of depression, negative automatic thoughts, effective social problem solving, ineffective social problem solving, rumination, parental care, parental overprotection, and negative life events. Structural equation modeling revealed that negative automatic thoughts, effective and ineffective social problem solving mediated the effects of rumination, negative life events, and parental care and overprotection on adolescent depression. These findings provide new knowledge about identified factors and the mechanisms of their influence on depression among Thai adolescents, which are appropriate for targeting preventive interventions. © 2012 Wiley Periodicals, Inc.

Promoting walking in older adults: Perceived neighborhood walkability influences the effectiveness of motivational messages.

PubMed

Notthoff, Nanna; Carstensen, Laura L

2017-06-01

Positively framed messages seem to promote walking in older adults better than negatively framed messages. This study targeted elderly people in communities unfavorable to walking. Walking was measured with pedometers during baseline (1 week) and intervention (4 weeks). Participants ( n = 74) were informed about either the benefits of walking or the negative consequences of not walking. Perceived neighborhood walkability was assessed with a modified version of the Neighborhood Walkability Scale. When perceived walkability was high, positively framed messages were more effective than negatively framed messages in promoting walking; when perceived walkability was low, negatively framed messages were comparably effective to positively framed messages.

Effects of negative gate-bias stress on the performance of solution-processed zinc-oxide transistors

NASA Astrophysics Data System (ADS)

Kim, Dongwook; Lee, Woo-Sub; Shin, Hyunji; Choi, Jong Sun; Zhang, Xue; Park, Jaehoon; Hwang, Jaeeun; Kim, Hongdoo; Bae, Jin-Hyuk

2014-08-01

We studied the effects of negative gate-bias stress on the electrical characteristics of top-contact zinc-oxide (ZnO) thin-film transistors (TFTs), which were fabricated by spin coating a ZnO solution onto a silicon-nitride gate dielectric layer. The negative gate-bias stress caused characteristic degradations in the on-state currents and the field-effect mobility of the fabricated ZnO TFTs. Additionally, a decrease in the off-state currents and a positive shift in the threshold voltage occurred with increasing stress time. These results indicate that the negative gate-bias stress caused an injection of electrons into the gate dielectric, thereby deteriorating the TFT's performance.

[Antimicrobial therapy in severe infections with multidrug-resistant Gram-negative bacterias].

PubMed

Duszyńska, Wiesława

2010-01-01

Multidrug-resistant Gram-negative bacteria pose a serious and rapidly emerging threat to patients in healthcare settings, and are especially prevalent and problematic in intensive therapy units. Recently, the emergence of pandrug-resistance in Gram-negative bacteria poses additional concerns. This review examines the clinical impact and epidemiology of multidrug-resistant Gram-negative bacteria as a cause of increased morbidity and mortality among ITU patients. Beta-lactamases, cephalosporinases and carbapenemases play the most important role in resistance to antibiotics. Despite the tendency to increased resistance, carbapenems administered by continuous infusion remain the most effective drugs in severe sepsis. Drug concentration monitoring, albeit rarely used in practice, is necessary to ensure an effective therapeutic effect.

Comparing the effects of negative and mixed emotional messages on predicted occasional excessive drinking.

PubMed

Carrera, Pilar; Caballero, Amparo; Muñoz, Dolores

2008-01-01

In this work we present two types of emotional message, negative (sadness) versus mixed (joy and sadness), with the aim of studying their differential effect on attitude change and the probability estimated by participants of repeating the behavior of occasional excessive drinking in the near future. The results show that for the group of participants with moderate experience in this behavior the negative message, compared to the mixed one, is associated with higher probability of repeating the risk behavior and a less negative attitude toward it. These results suggest that mixed emotional messages (e.g. joy and sadness messages) could be more effective in campaigns for the prevention of this risk behavior.

Do managed bees have negative effects on wild bees?: A systematic review of the literature

PubMed Central

Gratton, Claudio

2017-01-01

Managed bees are critical for crop pollination worldwide. As the demand for pollinator-dependent crops increases, so does the use of managed bees. Concern has arisen that managed bees may have unintended negative impacts on native wild bees, which are important pollinators in both agricultural and natural ecosystems. The goal of this study was to synthesize the literature documenting the effects of managed honey bees and bumble bees on wild bees in three areas: (1) competition for floral and nesting resources, (2) indirect effects via changes in plant communities, including the spread of exotic plants and decline of native plants, and (3) transmission of pathogens. The majority of reviewed studies reported negative effects of managed bees, but trends differed across topical areas. Of studies examining competition, results were highly variable with 53% reporting negative effects on wild bees, while 28% reported no effects and 19% reported mixed effects (varying with the bee species or variables examined). Equal numbers of studies examining plant communities reported positive (36%) and negative (36%) effects, with the remainder reporting no or mixed effects. Finally, the majority of studies on pathogen transmission (70%) reported potential negative effects of managed bees on wild bees. However, most studies across all topical areas documented the potential for impact (e.g. reporting the occurrence of competition or pathogens), but did not measure direct effects on wild bee fitness, abundance, or diversity. Furthermore, we found that results varied depending on whether managed bees were in their native or non-native range; managed bees within their native range had lesser competitive effects, but potentially greater effects on wild bees via pathogen transmission. We conclude that while this field has expanded considerably in recent decades, additional research measuring direct, long-term, and population-level effects of managed bees is needed to understand their potential impact on wild bees. PMID:29220412

Do managed bees have negative effects on wild bees?: A systematic review of the literature.

PubMed

Mallinger, Rachel E; Gaines-Day, Hannah R; Gratton, Claudio

2017-01-01

Managed bees are critical for crop pollination worldwide. As the demand for pollinator-dependent crops increases, so does the use of managed bees. Concern has arisen that managed bees may have unintended negative impacts on native wild bees, which are important pollinators in both agricultural and natural ecosystems. The goal of this study was to synthesize the literature documenting the effects of managed honey bees and bumble bees on wild bees in three areas: (1) competition for floral and nesting resources, (2) indirect effects via changes in plant communities, including the spread of exotic plants and decline of native plants, and (3) transmission of pathogens. The majority of reviewed studies reported negative effects of managed bees, but trends differed across topical areas. Of studies examining competition, results were highly variable with 53% reporting negative effects on wild bees, while 28% reported no effects and 19% reported mixed effects (varying with the bee species or variables examined). Equal numbers of studies examining plant communities reported positive (36%) and negative (36%) effects, with the remainder reporting no or mixed effects. Finally, the majority of studies on pathogen transmission (70%) reported potential negative effects of managed bees on wild bees. However, most studies across all topical areas documented the potential for impact (e.g. reporting the occurrence of competition or pathogens), but did not measure direct effects on wild bee fitness, abundance, or diversity. Furthermore, we found that results varied depending on whether managed bees were in their native or non-native range; managed bees within their native range had lesser competitive effects, but potentially greater effects on wild bees via pathogen transmission. We conclude that while this field has expanded considerably in recent decades, additional research measuring direct, long-term, and population-level effects of managed bees is needed to understand their potential impact on wild bees.

Primary prevention research: a preliminary review of program outcome studies.

PubMed

Schaps, E; Churgin, S; Palley, C S; Takata, B; Cohen, A Y

1980-07-01

This article reviews 35 drug abuse prevention program evaluations employing drug-specific outcome measures. Many of these evaluations assessed the effects of "new generation" prevention strategies: affective, peer-oriented, and multidimensional approaches. Only 14 studies evaluated purely informational programs. Evaluations were analyzed to ascertain (1) characteristics of the programs under study, (2) characteristics of the research designs, and (3) patterns among findings. This review provides some evidence that the newer prevention strategies may produce more positive and fewer negative outcomes than did older drug information approaches. Over 70% of the programs using the newer strategies produced some positive effects; only 29% showed negative effects. In contrast, 46% of informational programs showed positive effects; 46% showed negative effects. These findings must be approached with great caution, since the research was frequently scientifically inadequate, and since rigor of research was negatively correlated with intensity and duration of program services.

The Effects of a Distracting N-Back Task on Recognition Memory Are Reduced by Negative Emotional Intensity

PubMed Central

Buratto, Luciano G.; Pottage, Claire L.; Brown, Charity; Morrison, Catriona M.; Schaefer, Alexandre

2014-01-01

Memory performance is usually impaired when participants have to encode information while performing a concurrent task. Recent studies using recall tasks have found that emotional items are more resistant to such cognitive depletion effects than non-emotional items. However, when recognition tasks are used, the same effect is more elusive as recent recognition studies have obtained contradictory results. In two experiments, we provide evidence that negative emotional content can reliably reduce the effects of cognitive depletion on recognition memory only if stimuli with high levels of emotional intensity are used. In particular, we found that recognition performance for realistic pictures was impaired by a secondary 3-back working memory task during encoding if stimuli were emotionally neutral or had moderate levels of negative emotionality. In contrast, when negative pictures with high levels of emotional intensity were used, the detrimental effects of the secondary task were significantly attenuated. PMID:25330251

The effects of a distracting N-back task on recognition memory are reduced by negative emotional intensity.

PubMed

Buratto, Luciano G; Pottage, Claire L; Brown, Charity; Morrison, Catriona M; Schaefer, Alexandre

2014-01-01

Memory performance is usually impaired when participants have to encode information while performing a concurrent task. Recent studies using recall tasks have found that emotional items are more resistant to such cognitive depletion effects than non-emotional items. However, when recognition tasks are used, the same effect is more elusive as recent recognition studies have obtained contradictory results. In two experiments, we provide evidence that negative emotional content can reliably reduce the effects of cognitive depletion on recognition memory only if stimuli with high levels of emotional intensity are used. In particular, we found that recognition performance for realistic pictures was impaired by a secondary 3-back working memory task during encoding if stimuli were emotionally neutral or had moderate levels of negative emotionality. In contrast, when negative pictures with high levels of emotional intensity were used, the detrimental effects of the secondary task were significantly attenuated.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cao, Jianjun; Shen, Dongyi; Feng, Yaming

Negative refraction has attracted much interest for its promising capability in imaging applications. Such an effect can be implemented by negative index meta-materials, however, which are usually accompanied by high loss and demanding fabrication processes. Recently, alternative nonlinear approaches like phase conjugation and four wave mixing have shown advantages of low-loss and easy-to-implement, but associated problems like narrow accepting angles can still halt their practical applications. Here, we demonstrate theoretically and experimentally a scheme to realize negative refraction by nonlinear difference frequency generation with wide tunability, where a thin Beta barium borate slice serves as a negative refraction layer bendingmore » the input signal beam to the idler beam at a negative angle. Furthermore, we realize optical focusing effect using such nonlinear negative refraction, which may enable many potential applications in imaging science.« less

[SYMPTOMS OF NEGATIVE EFFECTS CUMULATION IN HUMANS AND ANIMALS UNDER THE ACTION OF G-LOADS OF VARYING DIRECTION IN CONTEXT OF AVIATION AND SPACE FLIGHTS].

PubMed

Kotovskaya, A R

2015-01-01

Author's and literary data are analyzed to evince symptoms of cumulation in humans and animals of the negative effects caused by g-forces of different directions experienced in aviation and space flights. The author cites evidence for the decisive importance of g-duration for the development of negative effects. Functional indices of g-tolerance do not rule out possible latent changes in visceral organs and body tissues.

Relations of spanking and other parenting characteristics to self-esteem and perceived fairness of parental discipline.

PubMed

Larzelere, R E; Klein, M; Schumm, W R; Alibrando, S A

1989-06-01

Punishment has long been a controversial topic in psychology, perhaps partly because its effects are different under different circumstances. This study used retrospective reports from college students to examine the effects of spanking, a common aversive punishment, on self-esteem and perceived fairness of parental discipline, while taking the effects of other parental characteristics into account. No parental characteristic interacted with the slightly negative effect of spanking on self-esteem and fairness. However, controlling for positive communication or for a parent-oriented motivation for spanking eliminated the negative effects of spanking, suggesting that the negative effects reflected use of spanking as a replacement for positive communication with the child.

Method effects: the problem with negatively versus positively keyed items.

PubMed

Lindwall, Magnus; Barkoukis, Vassilis; Grano, Caterina; Lucidi, Fabio; Raudsepp, Lennart; Liukkonen, Jarmo; Thøgersen-Ntoumani, Cecilie

2012-01-01

Using confirmatory factor analyses, we examined method effects on Rosenberg's Self-Esteem Scale (RSES; Rosenberg, 1965) in a sample of older European adults. Nine hundred forty nine community-dwelling adults 60 years of age or older from 5 European countries completed the RSES as well as measures of depression and life satisfaction. The 2 models that had an acceptable fit with the data included method effects. The method effects were associated with both positively and negatively worded items. Method effects models were invariant across gender and age, but not across countries. Both depression and life satisfaction predicted method effects. Individuals with higher depression scores and lower life satisfaction scores were more likely to endorse negatively phrased items.

Factors affecting plant growth in membrane nutrient delivery

NASA Technical Reports Server (NTRS)

Dreschel, T. W.; Wheeler, R. M.; Sager, J. C.; Knott, W. M.

1990-01-01

The development of the tubular membrane plant growth unit for the delivery of water and nutrients to roots in microgravity has recently focused on measuring the effects of changes in physical variables controlling solution availability to the plants. Significant effects of membrane pore size and the negative pressure used to contain the solution were demonstrated. Generally, wheat grew better in units with a larger pore size but equal negative pressure and in units with the same pore size but less negative pressure. Lettuce also exhibited better plant growth at less negative pressure.

Physical principles of the amplification of electromagnetic radiation due to negative electron masses in a semiconductor superlattice

NASA Astrophysics Data System (ADS)

Shorokhov, A. V.; Pyataev, M. A.; Khvastunov, N. N.; Hyart, T.; Kusmartsev, F. V.; Alekseev, K. N.

2015-02-01

In a superlattice placed in crossed static electric and magnetic fields, under certain conditions, the inversion of electron population can appear at which the average energy of electrons is above the middle of the mini-band and the effective mass of the electron is negative. This is the implementation of the negative effective mass amplifier and generator (NEMAG) in the superlattice. It can result in the amplification and generation of terahertz radiation even in the absence of negative differential conductivity.

Relation Between Mathematical Performance, Math Anxiety, and Affective Priming in Children With and Without Developmental Dyscalculia.

PubMed

Kucian, Karin; Zuber, Isabelle; Kohn, Juliane; Poltz, Nadine; Wyschkon, Anne; Esser, Günter; von Aster, Michael

2018-01-01

Many children show negative emotions related to mathematics and some even develop mathematics anxiety. The present study focused on the relation between negative emotions and arithmetical performance in children with and without developmental dyscalculia (DD) using an affective priming task. Previous findings suggested that arithmetic performance is influenced if an affective prime precedes the presentation of an arithmetic problem. In children with DD specifically, responses to arithmetic operations are supposed to be facilitated by both negative and mathematics-related primes (= negative math priming effect ).We investigated mathematical performance, math anxiety, and the domain-general abilities of 172 primary school children (76 with DD and 96 controls). All participants also underwent an affective priming task which consisted of the decision whether a simple arithmetic operation (addition or subtraction) that was preceded by a prime (positive/negative/neutral or mathematics-related) was true or false. Our findings did not reveal a negative math priming effect in children with DD. Furthermore, when considering accuracy levels, gender, or math anxiety, the negative math priming effect could not be replicated. However, children with DD showed more math anxiety when explicitly assessed by a specific math anxiety interview and showed lower mathematical performance compared to controls. Moreover, math anxiety was equally present in boys and girls, even in the earliest stages of schooling, and interfered negatively with performance. In conclusion, mathematics is often associated with negative emotions that can be manifested in specific math anxiety, particularly in children with DD. Importantly, present findings suggest that in the assessed age group, it is more reliable to judge math anxiety and investigate its effects on mathematical performance explicitly by adequate questionnaires than by an affective math priming task.

Relation Between Mathematical Performance, Math Anxiety, and Affective Priming in Children With and Without Developmental Dyscalculia

PubMed Central

Kucian, Karin; Zuber, Isabelle; Kohn, Juliane; Poltz, Nadine; Wyschkon, Anne; Esser, Günter; von Aster, Michael

2018-01-01

Many children show negative emotions related to mathematics and some even develop mathematics anxiety. The present study focused on the relation between negative emotions and arithmetical performance in children with and without developmental dyscalculia (DD) using an affective priming task. Previous findings suggested that arithmetic performance is influenced if an affective prime precedes the presentation of an arithmetic problem. In children with DD specifically, responses to arithmetic operations are supposed to be facilitated by both negative and mathematics-related primes (=negative math priming effect).We investigated mathematical performance, math anxiety, and the domain-general abilities of 172 primary school children (76 with DD and 96 controls). All participants also underwent an affective priming task which consisted of the decision whether a simple arithmetic operation (addition or subtraction) that was preceded by a prime (positive/negative/neutral or mathematics-related) was true or false. Our findings did not reveal a negative math priming effect in children with DD. Furthermore, when considering accuracy levels, gender, or math anxiety, the negative math priming effect could not be replicated. However, children with DD showed more math anxiety when explicitly assessed by a specific math anxiety interview and showed lower mathematical performance compared to controls. Moreover, math anxiety was equally present in boys and girls, even in the earliest stages of schooling, and interfered negatively with performance. In conclusion, mathematics is often associated with negative emotions that can be manifested in specific math anxiety, particularly in children with DD. Importantly, present findings suggest that in the assessed age group, it is more reliable to judge math anxiety and investigate its effects on mathematical performance explicitly by adequate questionnaires than by an affective math priming task. PMID:29755376

Hostile Attributional Bias, Negative Emotional Responding, and Aggression in Adults: Moderating Effects of Gender and Impulsivity

PubMed Central

Chen, Pan; Coccaro, Emil F.; Jacobson, Kristen C.

2012-01-01

The current study examined the main effects of hostile attributional bias (HAB) and negative emotional responding on a variety of aggressive behaviors in adults, including general aggression, physical aggression, relational aggression, and verbal aggression. Effects of both externalizing (anger) and internalizing (embarrassment/upset) negative emotions were considered. In addition, the moderating roles of gender and impulsivity on the effects of HAB and negative emotional responding were explored. Multilevel models were fitted to data from 2,749 adult twins aged 20–55 from the PennTwins cohort. HAB was positively associated with all four forms of aggression. There was also a significant interaction between impulsivity and HAB for general aggression. Specifically, the relationship between HAB and general aggression was only significant for individuals with average or above-average levels of impulsivity. Negative emotional responding was also found to predict all measures of aggression, although in different ways. Anger was positively associated with all forms of aggression, whereas embarrassment/upset predicted decreased levels of general, physical, and verbal aggression but increased levels of relational aggression. The associations between negative emotional responding and aggression were generally stronger for males than females. The current study provides evidence for the utility of HAB and negative emotional responding as predictors of adult aggression and further suggests that gender and impulsivity may moderate their links with aggression. PMID:24833604

Hostile attributional bias, negative emotional responding, and aggression in adults: moderating effects of gender and impulsivity.

PubMed

Chen, Pan; Coccaro, Emil F; Jacobson, Kristen C

2012-01-01

The current study examined the main effects of hostile attributional bias (HAB) and negative emotional responding on a variety of aggressive behaviors in adults, including general aggression, physical aggression, relational aggression, and verbal aggression. Effects of both externalizing (anger) and internalizing (embarrassment/upset) negative emotions were considered. In addition, the moderating roles of gender and impulsivity on the effects of HAB and negative emotional responding were explored. Multilevel models were fitted to data from 2,749 adult twins aged 20-55 from the PennTwins cohort. HAB was positively associated with all four forms of aggression. There was also a significant interaction between impulsivity and HAB for general aggression. Specifically, the relationship between HAB and general aggression was only significant for individuals with average or above-average levels of impulsivity. Negative emotional responding was also found to predict all measures of aggression, although in different ways. Anger was positively associated with all forms of aggression, whereas embarrassment/upset predicted decreased levels of general, physical, and verbal aggression but increased levels of relational aggression. The associations between negative emotional responding and aggression were generally stronger for males than females. The current study provides evidence for the utility of HAB and negative emotional responding as predictors of adult aggression and further suggests that gender and impulsivity may moderate their links with aggression. © 2011 Wiley Periodicals, Inc.

Inhibition of Return Is Modulated by Negative Stimuli: Evidence from Subliminal Perception.

PubMed

Pan, Fada; Wu, Xiaogang; Zhang, Li; Ou, Yuhong

2017-01-01

Inhibition of return (IOR) is considered as a "blindness mechanism" that emotional stimuli have no impact on it. Most previous studies suggested that IOR was not modulated by emotional cues. However, one key question they ignored was that only supraliminal presentation of emotional stimuli was used in their experiments. The present experiment is aimed at exploring the possible interaction between the IOR effect and subliminal emotional process. We manipulated three different kinds of valence strength of negative stimuli (high negative, HN; moderate negative, MN; low negative, LN) which were presented under the subliminal perception level and an event-related potentials (ERPs) recording was adopted. The results showed that, compared to MN and HN, the IOR effect triggered by peripheral cues was more significant for LN with aspects of behavioral and electrophysiological data (a reduction P1 effect, more negative on cued trials than on uncued trials for both early posterior Nd and Nd components). This indicated that IOR can be modulated by emotionally relevant stimuli. The automatic processing that was triggered by subliminally negative stimuli of peripheral cues had an influence on the shifting of spatial attention that was triggered by IOR. These two mechanisms may occur in the perceptual stage simultaneously.

Negativity Bias in Media Multitasking: The Effects of Negative Social Media Messages on Attention to Television News Broadcasts.

PubMed

Kätsyri, Jari; Kinnunen, Teemu; Kusumoto, Kenta; Oittinen, Pirkko; Ravaja, Niklas

2016-01-01

Television viewers' attention is increasingly more often divided between television and "second screens", for example when viewing television broadcasts and following their related social media discussion on a tablet computer. The attentional costs of such multitasking may vary depending on the ebb and flow of the social media channel, such as its emotional contents. In the present study, we tested the hypothesis that negative social media messages would draw more attention than similar positive messages. Specifically, news broadcasts were presented in isolation and with simultaneous positive or negative Twitter messages on a tablet to 38 participants in a controlled experiment. Recognition memory, gaze tracking, cardiac responses, and self-reports were used as attentional indices. The presence of any tweets on the tablet decreased attention to the news broadcasts. As expected, negative tweets drew longer viewing times and elicited more attention to themselves than positive tweets. Negative tweets did not, however, decrease attention to the news broadcasts. Taken together, the present results demonstrate a negativity bias exists for social media messages in media multitasking; however, this effect does not amplify the overall detrimental effects of media multitasking.

Negativity Bias in Media Multitasking: The Effects of Negative Social Media Messages on Attention to Television News Broadcasts

PubMed Central

Kätsyri, Jari; Kinnunen, Teemu; Kusumoto, Kenta; Oittinen, Pirkko; Ravaja, Niklas

2016-01-01

Television viewers’ attention is increasingly more often divided between television and “second screens”, for example when viewing television broadcasts and following their related social media discussion on a tablet computer. The attentional costs of such multitasking may vary depending on the ebb and flow of the social media channel, such as its emotional contents. In the present study, we tested the hypothesis that negative social media messages would draw more attention than similar positive messages. Specifically, news broadcasts were presented in isolation and with simultaneous positive or negative Twitter messages on a tablet to 38 participants in a controlled experiment. Recognition memory, gaze tracking, cardiac responses, and self-reports were used as attentional indices. The presence of any tweets on the tablet decreased attention to the news broadcasts. As expected, negative tweets drew longer viewing times and elicited more attention to themselves than positive tweets. Negative tweets did not, however, decrease attention to the news broadcasts. Taken together, the present results demonstrate a negativity bias exists for social media messages in media multitasking; however, this effect does not amplify the overall detrimental effects of media multitasking. PMID:27144385

Trait emotional intelligence and mental distress: the mediating role of positive and negative affect.

PubMed

Kong, Feng; Zhao, Jingjing; You, Xuqun

2012-01-01

Over the past decade, emotional intelligence (EI) has received much attention in the literature. Previous studies indicated that higher trait or ability EI was associated with greater mental distress. The present study focused on mediating effects of positive and negative affect on the association between trait EI and mental distress in a sample of Chinese adults. The participants were 726 Chinese adults (384 females) with an age range of 18-60 years. Data were collected by using the Wong Law Emotional Intelligence Scale, the Positive Affect and Negative Affect Scale, and the General Health Questionnaire. Hierarchical regression analysis showed that EI was a significant predictor of positive affect, negative affect and mental distress. Further mediation analysis showed that positive and negative affect acted as partial mediators of the relationship between EI and mental distress. Furthermore, effect contrasts showed that there was no significant difference between the specific indirect effects through positive affect and through negative affect. This result indicated that positive affect and negative affect played an equally important function in the association between EI and distress. The significance and limitations of the results are discussed.

Assessing the Personal Negative Impacts of Hooking Up Experienced by College Students: Gender Differences and Mental Health.

PubMed

Napper, Lucy E; Montes, Kevin S; Kenney, Shannon R; LaBrie, Joseph W

2016-09-01

Hooking up is a normative behavior among college students that is associated with a range of positive and negative consequences. While previous research has primarily focused on women's negative experiences of hooking up, the current study explored the relationships among hooking up behaviors, psychological distress, and a broad range of negative effects of hooking up in both male and female college students. Using a multisite sample of college students, we developed the 14-item Negative Impact of Hookups Inventory (NIHI) to assess negative health outcomes, emotional responses, and social consequences associated with hooking up. Unprotected sex and having more hookup partners were associated with greater negative experiences of hooking up. Contrary to expectations, there were no gender differences in the total number of negative hookup effects, although men reported more frequent hookups. In addition, negative impacts of hooking up were positively associated with psychological distress regardless of gender. The NIHI may offer a useful tool to assess the negative impacts of hooking up. Understanding students' hookup experiences is an important step toward developing targeted health interventions related to hooking up behavior in young adult populations.

PERCEIVED RACISM AND NEGATIVE AFFECT: ANALYSES OF TRAIT AND STATE MEASURES OF AFFECT IN A COMMUNITY SAMPLE

PubMed Central

BRONDOLO, ELIZABETH; BRADY, NISHA; THOMPSON, SHOLA; TOBIN, JONATHAN N.; CASSELLS, ANDREA; SWEENEY, MONICA; MCFARLANE, DELANO; CONTRADA, RICHARD J.

2008-01-01

Racism is a significant psychosocial stressor that is hypothesized to have negative psychological and physical health consequences. The Reserve Capacity Model (Gallo & Matthews, 2003) suggests that low socioeconomic status may influence health through its effects on negative affect. We extend this model to study the effects of racism, examining the association of lifetime perceived racism to trait and daily negative affect. A multiethnic sample of 362 American–born Black and Latino adults completed the Perceived Ethnic Discrimination Questionnaire–Community Version (PEDQ–CV). Trait negative affect was assessed with the Positive and Negative Affect Schedule (PANAS), and state negative affect was measured using ecological momentary assessments (EMA), in the form of an electronic diary. Analyses revealed a significant relationship of lifetime perceived racism to both daily negative affect and trait negative affect, even when controlling for trait hostility and socioeconomic status. The relationship of perceived racism to negative affect was moderated by education, such that the relationships were strongest for those with less than a high school education. The findings support aspects of the Reserve Capacity Model and identify pathways through which perceived racism may affect health status. PMID:19079772

Good things don't come easy (to mind): explaining framing effects in judgments of truth.

PubMed

Hilbig, Benjamin E

2012-01-01

Recently, the general phenomenon of a positive-negative-asymmetry was extended to judgments of truth. That is, negatively framed statements were shown to receive substantially higher truth ratings than formally equivalent statements framed positively. However, the cognitive mechanisms underlying this effect are unknown, so far. In the current work, two potential accounts are introduced and tested against each other in three experiments: On the one hand, negative framing may induce increased elaboration and thereby persuasion. Alternatively, negative framing could yield faster retrieval or generation of evidence and thus influence subjective veracity via experiential fluency. Two experiments drawing on response latencies and one manipulating the delay between information acquisition and judgment provide support for the fluency-based account. Overall, results replicate and extend the negatively-biased framing effect in truth judgments and show that processing fluency may account for it. © 2011 Hogrefe Publishing

The Older Adult Positivity Effect in Evaluations of Trustworthiness: Emotion Regulation or Cognitive Capacity?

PubMed

Zebrowitz, Leslie A; Boshyan, Jasmine; Ward, Noreen; Gutchess, Angela; Hadjikhani, Nouchine

2017-01-01

An older adult positivity effect, i.e., the tendency for older adults to favor positive over negative stimulus information more than do younger adults, has been previously shown in attention, memory, and evaluations. This effect has been attributed to greater emotion regulation in older adults. In the case of attention and memory, this explanation has been supported by some evidence that the older adult positivity effect is most pronounced for negative stimuli, which would motivate emotion regulation, and that it is reduced by cognitive load, which would impede emotion regulation. We investigated whether greater older adult positivity in the case of evaluative responses to faces is also enhanced for negative stimuli and attenuated by cognitive load, as an emotion regulation explanation would predict. In two studies, younger and older adults rated trustworthiness of faces that varied in valence both under low and high cognitive load, with the latter manipulated by a distracting backwards counting task. In Study 1, face valence was manipulated by attractiveness (low /disfigured faces, medium, high/fashion models' faces). In Study 2, face valence was manipulated by trustworthiness (low, medium, high). Both studies revealed a significant older adult positivity effect. However, contrary to an emotion regulation account, this effect was not stronger for more negative faces, and cognitive load increased rather than decreased the rated trustworthiness of negatively valenced faces. Although inconsistent with emotion regulation, the latter effect is consistent with theory and research arguing that more cognitive resources are required to process negative stimuli, because they are more cognitively elaborated than positive ones. The finding that increased age and increased cognitive load both enhanced the positivity of trustworthy ratings suggests that the older adult positivity effect in evaluative ratings of faces may reflect age-related declines in cognitive capacity rather than increases in the regulation of negative emotions.

Nocebo phenomena in medicine: their relevance in everyday clinical practice.

PubMed

Häuser, Winfried; Hansen, Ernil; Enck, Paul

2012-06-01

Nocebo phenomena are common in clinical practice and have recently become a popular topic of research and discussion among basic scientists, clinicians, and ethicists. We selectively searched the PubMed database for articles published up to December 2011 that contained the key words "nocebo" or "nocebo effect." By definition, a nocebo effect is the induction of a symptom perceived as negative by sham treatment and/or by the suggestion of negative expectations. A nocebo response is a negative symptom induced by the patient's own negative expectations and/or by negative suggestions from clinical staff in the absence of any treatment. The underlying mechanisms include learning by Pavlovian conditioning and reaction to expectations induced by verbal information or suggestion. Nocebo responses may come about through unintentional negative suggestion on the part of physicians and nurses. Information about possible complications and negative expectations on the patient's part increases the likelihood of adverse effects. Adverse events under treatment with medications sometimes come about by a nocebo effect. Physicians face an ethical dilemma, as they are required not just to inform patients of the potential complications of treatment, but also to minimize the likelihood of these complications, i.e., to avoid inducing them through the potential nocebo effect of thorough patient information. Possible ways out of the dilemma include emphasizing the fact that the proposed treatment is usually well tolerated, or else getting the patient's permission to inform less than fully about its possible side effects. Communication training in medical school, residency training, and continuing medical education would be desirable so that physicians can better exploit the power of words to patients' benefit, rather than their detriment.

Cosmic Rays and Clouds, 1. Formation of Lead Mesoatoms In Neutron Monitor By Soft Negative Muons and Expected Atmospheric Electric Field Effect In The Cosmic Ray Neutron Component

NASA Astrophysics Data System (ADS)

Dorman, L. I.; Dorman, I. V.

We extend our model (Dorman and Dorman, 1995) of cosmic ray atmospheric electric field effect on the case of neutron monitor. We take into account that about 0.07 of neu- tron monitor counting rate caused by negative soft muons captured by lead nucleons and formed mesoatoms with generation of several MeV energy neutrons from lead. In this case the neutron monitor or neutron supermonitor works as analyzer which de- tects muons of only one, negative sign. It is very important because the atmospheric electric field effect have opposite signs for positive and negative muons that main part of this effect in the muon telescope or in ionization chamber is compensated and we can observe only small part of total effect of one sign muons. On the basis of our gen- eral theory of cosmic ray meteorological effects with taking into account of negative soft muon acceleration and deceleration in the Earth atmosphere (in dependence of di- rection and intensity of electric field) we discuss the possibility of existing this effect in cosmic ray neutron component and made some rough estimations. REFERENCES: Dorman L.I. and Dorman I.V., 1995. "Cosmic-ray atmospheric electric field effects". Canadian J. of Physics, Vol. 73, pp. 440-443.

Negative refraction angular characterization in one-dimensional photonic crystals.

PubMed

Lugo, Jesus Eduardo; Doti, Rafael; Faubert, Jocelyn

2011-04-06

Photonic crystals are artificial structures that have periodic dielectric components with different refractive indices. Under certain conditions, they abnormally refract the light, a phenomenon called negative refraction. Here we experimentally characterize negative refraction in a one dimensional photonic crystal structure; near the low frequency edge of the fourth photonic bandgap. We compare the experimental results with current theory and a theory based on the group velocity developed here. We also analytically derived the negative refraction correctness condition that gives the angular region where negative refraction occurs. By using standard photonic techniques we experimentally determined the relationship between incidence and negative refraction angles and found the negative refraction range by applying the correctness condition. In order to compare both theories with experimental results an output refraction correction was utilized. The correction uses Snell's law and an effective refractive index based on two effective dielectric constants. We found good agreement between experiment and both theories in the negative refraction zone. Since both theories and the experimental observations agreed well in the negative refraction region, we can use both negative refraction theories plus the output correction to predict negative refraction angles. This can be very useful from a practical point of view for space filtering applications such as a photonic demultiplexer or for sensing applications.

Negative Refraction Angular Characterization in One-Dimensional Photonic Crystals

PubMed Central

Lugo, Jesus Eduardo; Doti, Rafael; Faubert, Jocelyn

2011-01-01

Background Photonic crystals are artificial structures that have periodic dielectric components with different refractive indices. Under certain conditions, they abnormally refract the light, a phenomenon called negative refraction. Here we experimentally characterize negative refraction in a one dimensional photonic crystal structure; near the low frequency edge of the fourth photonic bandgap. We compare the experimental results with current theory and a theory based on the group velocity developed here. We also analytically derived the negative refraction correctness condition that gives the angular region where negative refraction occurs. Methodology/Principal Findings By using standard photonic techniques we experimentally determined the relationship between incidence and negative refraction angles and found the negative refraction range by applying the correctness condition. In order to compare both theories with experimental results an output refraction correction was utilized. The correction uses Snell's law and an effective refractive index based on two effective dielectric constants. We found good agreement between experiment and both theories in the negative refraction zone. Conclusions/Significance Since both theories and the experimental observations agreed well in the negative refraction region, we can use both negative refraction theories plus the output correction to predict negative refraction angles. This can be very useful from a practical point of view for space filtering applications such as a photonic demultiplexer or for sensing applications. PMID:21494332

Role-modeling and medical error disclosure: a national survey of trainees.

PubMed

Martinez, William; Hickson, Gerald B; Miller, Bonnie M; Doukas, David J; Buckley, John D; Song, John; Sehgal, Niraj L; Deitz, Jennifer; Braddock, Clarence H; Lehmann, Lisa Soleymani

2014-03-01

To measure trainees' exposure to negative and positive role-modeling for responding to medical errors and to examine the association between that exposure and trainees' attitudes and behaviors regarding error disclosure. Between May 2011 and June 2012, 435 residents at two large academic medical centers and 1,187 medical students from seven U.S. medical schools received anonymous, electronic questionnaires. The questionnaire asked respondents about (1) experiences with errors, (2) training for responding to errors, (3) behaviors related to error disclosure, (4) exposure to role-modeling for responding to errors, and (5) attitudes regarding disclosure. Using multivariate regression, the authors analyzed whether frequency of exposure to negative and positive role-modeling independently predicted two primary outcomes: (1) attitudes regarding disclosure and (2) nontransparent behavior in response to a harmful error. The response rate was 55% (884/1,622). Training on how to respond to errors had the largest independent, positive effect on attitudes (standardized effect estimate, 0.32, P < .001); negative role-modeling had the largest independent, negative effect (standardized effect estimate, -0.26, P < .001). Positive role-modeling had a positive effect on attitudes (standardized effect estimate, 0.26, P < .001). Exposure to negative role-modeling was independently associated with an increased likelihood of trainees' nontransparent behavior in response to an error (OR 1.37, 95% CI 1.15-1.64; P < .001). Exposure to role-modeling predicts trainees' attitudes and behavior regarding the disclosure of harmful errors. Negative role models may be a significant impediment to disclosure among trainees.

With a little help from my assistant: buffering the negative effects of emotional dissonance on dentist performance.

PubMed

Rodríguez-Sánchez, Alma M; Hakanen, Jari J; Perhoniemi, Riku; Salanova, Marisa

2013-10-01

In this study, we hypothesized that dentist' interpersonal resources (good cooperation with one's assistant) together with their personal resources (optimism) buffer the negative effects of emotional dissonance (a demand that occurs when there is a difference between felt and displayed emotions) on job performance (in-role and extra-role performance) over time. We carried out Hierarchical Regression Modeling on a sample of 1954 Finnish dentists who participated in a two-wave 4-year longitudinal study. Results showed that good cooperation with dental assistants buffered the negative effects of emotional dissonance on both in-role and extra-role performance among the dentists in the long term. However, unexpectedly, dentists' high optimism did not buffer their in-role nor extra-role performance over time under conditions of experiencing high emotional dissonance. We conclude that interpersonal job resources such as good cooperation with one's colleagues may buffer the negative effect of emotional dissonance on dentists' job performance even in the long term, whereas the role of personal resources (e.g., optimism) may be less important for maintaining high job performance under conditions of emotional dissonance. The study novelties include the test of the negative effects of emotional dissonance on long-term performance in dentistry and the identification of the job rather than personal resources as the buffers against the negative effects of emotional dissonance on long-term performance. © 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Negative cancer stereotypes and disease-specific self-concept in head and neck cancer.

PubMed

Wong, Janice C; Payne, Ada Y M; Mah, Kenneth; Lebel, Sophie; Lee, Ruth N F; Irish, Jonathan; Rodin, Gary; Devins, Gerald M

2013-05-01

Life-threatening diseases, such as head and neck cancer (HNCa), can stimulate the emergence of a new disease-specific self-concept. We hypothesized that (i) negative cancer-stereotypes invoke distancing, which inhibits the adoption of a disease-specific self-concept and (ii) patient characteristics, disease and treatment factors, and cancer-related stressors moderate the phenomenon. Head and neck cancer outpatients (N = 522) completed a semantic-differential measure of disease-specific self-concept (perceived similarity to the 'cancer patient') and other self-report measures in structured interviews. Negative cancer-stereotypes were represented by the number of semantic-differential dimensions (0-3) along which respondents evaluated the stereotypic 'cancer patient' negatively (i.e., negative valence). We tested the two-way interactions between negative valence and hypothesized moderator variables. We observed significant negative valence × moderator interactions for the following: (i) patient characteristics (education, employment, social networks); (ii) disease and treatment factors (cancer-symptom burden); and (iii) cancer-related stressors (uncertainty, lack of information, and existential threats). Negative cancer stereotypes were consistently associated with distancing of self from the stereotypic 'cancer patient,' but the effect varied across moderator variables. All significant moderators (except employment and social networks) were associated with increasing perceived similarity to the 'cancer patient' when respondents maintained negative stereotypes; perceived similarity decreased when people were employed or had extensive social networks. Moderator effects were less pronounced when respondents did not endorse negative cancer stereotypes. When they hold negative stereotypes, people with HNCa distance themselves from a 'cancer patient' identity to preserve self-esteem or social status, but exposure to cancer-related stressors and adaptive demands may attenuate these effects. Copyright © 2012 John Wiley & Sons, Ltd.

Alternative stable states and alternative endstates of community assembly through intra- and interspecific positive and negative interactions.

PubMed

Gerla, Daan J; Mooij, Wolf M

2014-09-01

Positive and negative interactions within and between species may occur simultaneously, with the net effect depending on population densities. For instance, at low densities plants may ameliorate stress, while competition for resources dominates at higher densities. Here, we propose a simple two-species model in which con- and heterospecifics have a positive effect on per capita growth rate at low densities, while negative interactions dominate at high densities. The model thus includes both Allee effects (intraspecific positive effects) and mutualism (interspecific positive effects), as well as intra- and interspecific competition. Using graphical methods we derive conditions for alternative stable states and species coexistence. We show that mutual non-invasibility (i.e. the inability of each species to invade a population of the other) is more likely when species have a strong positive effect on the own species or a strong negative effect on the other species. Mutual non-invasibility implies alternative stable states, however, there may also be alternative stable states at which species coexist. In the case of species symmetry (i.e. when species are indistinguishable), such alternative coexistence states require that if the positive effect exerted at low densities at the own species is stronger than on the other species, the negative effect at higher densities is also stronger on the own species than on the other species, or, vice versa, if the interspecific positive effects at low densities are stronger than the intraspecific effects, the negative effects at higher densities are also stronger between species than within species. However, the reachability of alternative stable states is restricted by the frequency and density at which species are introduced during community assembly, so that alternative stable states do not always represent alternative endstates of community assembly. Copyright © 2014 Elsevier Inc. All rights reserved.

Anxiety symptoms mediate the relationship between exposure to stressful negative life events and depressive symptoms: A conditional process modelling of the protective effects of resilience.

PubMed

Anyan, Frederick; Worsley, Lyn; Hjemdal, Odin

2017-10-01

Resilience has provided a useful framework that elucidates the effects of protective factors to overcome psychological adversities but studies that address the potential contingencies of resilience to protect against direct and indirect negative effects are lacking. These obvious gaps have also resulted in oversimplification of complex processes that can be clarified by moderated mediation associations. This study examines a conditional process modelling of the protective effects of resilience against indirect effects. Two separate samples were recruited in a cross-sectional survey from Australia and Norway to complete the Patient Health Questionnaire -9, Generalized Anxiety Disorder, Stressful Negative Life Events Questionnaire and the Resilience Scale for Adults. The final sample sizes were 206 (females=114; males=91; other=1) and 210 (females=155; males=55) for Australia and Norway respectively. Moderated mediation analyses were conducted across the samples. Anxiety symptoms mediated the relationship between exposure to stressful negative life events and depressive symptoms in both samples. Conditional indirect effects of exposure to stressful negative life events on depressive symptoms mediated by anxiety symptoms showed that high subgroup of resilience was associated with less effect of exposure to stressful negative life events through anxiety symptoms on depressive symptoms than the low subgroup of resilience. As a cross-sectional survey, the present study does not answer questions about causal processes despite the use of a conditional process modelling. These findings support that, resilience protective resources can protect against both direct and indirect - through other channels - psychological adversities. Copyright © 2017 Elsevier B.V. All rights reserved.

Relationships between stress, negative emotions, resilience, and smoking: Testing a moderated mediation model

PubMed Central

Wang, Yan; Chen, Xinguang; Gong, Jie; Yan, Yaqiong

2016-01-01

Objective More effective tobacco prevention and cessation programs require in-depth understanding of the mechanism by which multiple factors interact with each other to affect smoking behaviors. Stress has long been recognized as a risk factor for smoking. However, the underlying mediation and moderation mechanisms are far from clear. The purpose of this study was to examine the role of negative emotions in mediating the link between stress and smoking and whether this indirect link was modified by resilience. Methods Survey data were collected using audio computer assisted self-interview (ACASI) from a large random sample of urban residents (n=1249, mean age = 35.1, 45.3% male) in Wuhan, China. Perceived stress, negative emotions (anxiety, depression), resilience were measured with reliable instruments also validated in China. Self-reported smoking was validated with exhaled carbon monoxide. Results Mediation analysis indicated that two negative emotions fully mediated the link between stress and intensity of smoking (assessed by number of cigarettes smoked per day, effect = .082 for anxiety and .083 for depression) and nicotine dependence (assessed by DSM-IV standard, effect = .134 for anxiety and .207 for depression). Moderated mediation analysis demonstrated that the mediation effects of negative emotions were negatively associated with resilience. Conclusions Results suggest resilience interacts with stress and negative emotions to affect the risk of tobacco use and nicotine dependence among Chinese adults. Further research with longitudinal data is needed to verify the findings of this study and to estimate the effect size of resilience in tobacco intervention and cessation programs. PMID:26894428

Negative affect and smoking motives sequentially mediate the effect of panic attacks on tobacco-relevant processes

PubMed Central

Farris, Samantha G.; Zvolensky, Michael J.; Blalock, Janice A.; Schmidt, Norman B.

2018-01-01

Introduction Empirical work has documented a robust and consistent relation between panic attacks and smoking behavior. Theoretical models posit smokers with panic attacks may rely on smoking to help them manage chronically elevated negative affect due to uncomfortable bodily states, which may explain higher levels of nicotine dependence and quit problems. Methods The current study examined the effects of panic attack history on nicotine dependence, perceived barriers for quitting, smoking inflexibility when emotionally distressed, and expired carbon monoxide among 461 treatment-seeking smokers. A multiple mediator path model was evaluated to examine the indirect effects of negative affect and negative affect reduction motives as mediators of the panic attack-smoking relations. Results Panic attack history was indirectly related to greater levels of nicotine dependence (b=0.039, CI95%=0.008, 0.097), perceived barriers to smoking cessation (b=0.195, CI95%=0.043, 0.479), smoking inflexibility/avoidance when emotionally distressed (b=0.188, CI95%=0.041, 0.445), and higher levels of expired carbon monoxide (b=0.071, CI95%=0.010, 0.230) through the sequential effects of negative affect and negative affect smoking motives. Conclusions The present results provide empirical support for the sequential mediating role of negative affect and smoking motives for negative affect reduction in the relation between panic attacks and a variety of smoking variables in treatment-seeking smokers. These mediating variables are likely important processes to address in smoking cessation treatment, especially in panic-vulnerable smokers. PMID:24720260

Negative affect and smoking motives sequentially mediate the effect of panic attacks on tobacco-relevant processes.

PubMed

Farris, Samantha G; Zvolensky, Michael J; Blalock, Janice A; Schmidt, Norman B

2014-05-01

Empirical work has documented a robust and consistent relation between panic attacks and smoking behavior. Theoretical models posit smokers with panic attacks may rely on smoking to help them manage chronically elevated negative affect due to uncomfortable bodily states, which may explain higher levels of nicotine dependence and quit problems. The current study examined the effects of panic attack history on nicotine dependence, perceived barriers for quitting, smoking inflexibility when emotionally distressed, and expired carbon monoxide among 461 treatment-seeking smokers. A multiple mediator path model was evaluated to examine the indirect effects of negative affect and negative affect reduction motives as mediators of the panic attack-smoking relations. Panic attack history was indirectly related to greater levels of nicotine dependence (b = 0.039, CI95% = 0.008, 0.097), perceived barriers to smoking cessation (b = 0.195, CI95% = 0.043, 0.479), smoking inflexibility/avoidance when emotionally distressed (b = 0.188, CI95% = 0.041, 0.445), and higher levels of expired carbon monoxide (b = 0.071, CI95% = 0.010, 0.230) through the sequential effects of negative affect and negative affect smoking motives. The present results provide empirical support for the sequential mediating role of negative affect and smoking motives for negative affect reduction in the relation between panic attacks and a variety of smoking variables in treatment-seeking smokers. These mediating variables are likely important processes to address in smoking cessation treatment, especially in panic-vulnerable smokers.

Feedback-related negativity codes outcome valence, but not outcome expectancy, during reversal learning.

PubMed

von Borries, A K L; Verkes, R J; Bulten, B H; Cools, R; de Bruijn, E R A

2013-12-01

Optimal behavior depends on the ability to assess the predictive value of events and to adjust behavior accordingly. Outcome processing can be studied by using its electrophysiological signatures--that is, the feedback-related negativity (FRN) and the P300. A prominent reinforcement-learning model predicts an FRN on negative prediction errors, as well as implying a role for the FRN in learning and the adaptation of behavior. However, these predictions have recently been challenged. Notably, studies so far have used tasks in which the outcomes have been contingent on the response. In these paradigms, the need to adapt behavioral responses is present only for negative, not for positive feedback. The goal of the present study was to investigate the effects of positive as well as negative violations of expectancy on FRN amplitudes, without the usual confound of behavioral adjustments. A reversal-learning task was employed in which outcome value and outcome expectancy were orthogonalized; that is, both positive and negative outcomes were equally unexpected. The results revealed a double dissociation, with effects of valence but not expectancy on the FRN and, conversely, effects of expectancy but not valence on the P300. While FRN amplitudes were largest for negative-outcome trials, irrespective of outcome expectancy, P300 amplitudes were largest for unexpected-outcome trials, irrespective of outcome valence. These FRN effects were interpreted to reflect an evaluation along a good-bad dimension, rather than reflecting a negative prediction error or a role in behavioral adaptation. By contrast, the P300 reflects the updating of information relevant for behavior in a changing context.

The effect of music-induced mood on attentional networks.

PubMed

Jiang, Jun; Scolaro, Ashley J; Bailey, Kira; Chen, Antao

2011-06-01

Attention network theory suggests that there are three separate neural networks that execute the discrete functions of alerting, orienting, and executive attention. Previous research on the influence of mood on attention has shown subtle and inconsistent results. The attention network theory may aid in clarifying the influence of mood on attention. The present study investigated the influence of mood on attentional networks in a normal population. Participants performed the Attention Network Test (ANT), which provides functional measures of alerting, orienting, and executive attention. Positive or negative mood was induced by listening to music with a positive or negative valence, respectively; neutral mood was induced by reading a collection of basic facts about China. The results revealed that negative mood led to a significantly higher alerting efficiency relative to other moods, while there were no significant mood effects on orienting or executive attention efficiency. According to the algorithm underlying the ANT, the higher alerting efficiency in the negative mood condition can be attributed to relatively greater benefits of cueing effects. The findings are discussed in the context of the noradrenergic system and of evolutionary significance. Specifically, the increase in the alerting function during negative mood states may be due to the modulation effect of negative mood on the noradrenergic system, and/or to the survival benefit resulting from an increase in automatic vigilance towards negative information. The current results suggest that as the influence of negative mood on attention appears to specifically consist in an enhanced alerting function, it may not be found in studies where the three attentional networks are not dissociated.

Effects of cognitive remediation on negative symptoms dimensions: exploring the role of working memory.

PubMed

Cella, M; Stahl, D; Morris, S; Keefe, R S E; Bell, M D; Wykes, T

2017-09-04

Recent theories suggest that poor working memory (WM) may be the cognitive underpinning of negative symptoms in people with schizophrenia. In this study, we first explore the effect of cognitive remediation (CR) on two clusters of negative symptoms (i.e. expressive and social amotivation), and then assess the relevance of WM gains as a possible mediator of symptom improvement. Data were accessed for 309 people with schizophrenia from the NIMH Database of Cognitive Training and Remediation Studies and a separate study. Approximately half the participants received CR and the rest were allocated to a control condition. All participants were assessed before and after therapy and at follow-up. Expressive negative symptoms and social amotivation symptoms scores were calculated from the Positive and Negative Syndrome Scale. WM was assessed with digit span and letter-number span tests. Participants who received CR had a significant improvement in WM scores (d = 0.27) compared with those in the control condition. Improvements in social amotivation levels approached statistical significance (d = -0.19), but change in expressive negative symptoms did not differ between groups. WM change did not mediate the effect of CR on social amotivation. The results suggest that a course of CR may benefit behavioural negative symptoms. Despite hypotheses linking memory problems with negative symptoms, the current findings do not support the role of this cognitive domain as a significant mediator. The results indicate that WM improves independently from negative symptoms reduction.

Work–Family Conflict and Mental Health Among Female Employees: A Sequential Mediation Model via Negative Affect and Perceived Stress

PubMed Central

Zhou, Shiyi; Da, Shu; Guo, Heng; Zhang, Xichao

2018-01-01

After the implementation of the universal two-child policy in 2016, more and more working women have found themselves caught in the dilemma of whether to raise a baby or be promoted, which exacerbates work–family conflicts among Chinese women. Few studies have examined the mediating effect of negative affect. The present study combined the conservation of resources model and affective events theory to examine the sequential mediating effect of negative affect and perceived stress in the relationship between work–family conflict and mental health. A valid sample of 351 full-time Chinese female employees was recruited in this study, and participants voluntarily answered online questionnaires. Pearson correlation analysis, structural equation modeling, and multiple mediation analysis were used to examine the relationships between work–family conflict, negative affect, perceived stress, and mental health in full-time female employees. We found that women’s perceptions of both work-to-family conflict and family-to-work conflict were significant negatively related to mental health. Additionally, the results showed that negative affect and perceived stress were negatively correlated with mental health. The 95% confidence intervals indicated the sequential mediating effect of negative affect and stress in the relationship between work–family conflict and mental health was significant, which supported the hypothesized sequential mediation model. The findings suggest that work–family conflicts affected the level of self-reported mental health, and this relationship functioned through the two sequential mediators of negative affect and perceived stress. PMID:29719522

Work-Family Conflict and Mental Health Among Female Employees: A Sequential Mediation Model via Negative Affect and Perceived Stress.

PubMed

Zhou, Shiyi; Da, Shu; Guo, Heng; Zhang, Xichao

2018-01-01

After the implementation of the universal two-child policy in 2016, more and more working women have found themselves caught in the dilemma of whether to raise a baby or be promoted, which exacerbates work-family conflicts among Chinese women. Few studies have examined the mediating effect of negative affect. The present study combined the conservation of resources model and affective events theory to examine the sequential mediating effect of negative affect and perceived stress in the relationship between work-family conflict and mental health. A valid sample of 351 full-time Chinese female employees was recruited in this study, and participants voluntarily answered online questionnaires. Pearson correlation analysis, structural equation modeling, and multiple mediation analysis were used to examine the relationships between work-family conflict, negative affect, perceived stress, and mental health in full-time female employees. We found that women's perceptions of both work-to-family conflict and family-to-work conflict were significant negatively related to mental health. Additionally, the results showed that negative affect and perceived stress were negatively correlated with mental health. The 95% confidence intervals indicated the sequential mediating effect of negative affect and stress in the relationship between work-family conflict and mental health was significant, which supported the hypothesized sequential mediation model. The findings suggest that work-family conflicts affected the level of self-reported mental health, and this relationship functioned through the two sequential mediators of negative affect and perceived stress.

The Replicability of the Negative Testing Effect: Differences across Participant Populations

ERIC Educational Resources Information Center

Mulligan, Neil W.; Rawson, Katherine A.; Peterson, Daniel J.; Wissman, Kathryn T.

2018-01-01

Although memory retrieval often enhances subsequent memory, Peterson and Mulligan (2013) reported conditions under which retrieval produces poorer subsequent recall--the negative testing effect. The item-specific--relational account proposes that the effect occurs when retrieval disrupts interitem organizational processing relative to the restudy…

Countering the negative effects of job insecurity through participative decision making: lessons from the demand-control model.

PubMed

Probst, Tahira M

2005-10-01

This study examined the effectiveness of increased organizational participative decision making in attenuating the negative consequences of job insecurity. Data were collected from 807 employees in 6 different companies. Analyses suggest that job insecurity is related to lower coworker, work, and supervisor satisfaction and higher turnover intentions and work withdrawal behaviors. However, employees with greater participative decision-making opportunities reported fewer negative consequences of job insecurity compared with employees with fewer participative decision-making opportunities. Results are interpreted using the demand-control model and suggest that organizations that allow greater employee participative decision making may experience fewer negative side effects from today's rising levels of employee job insecurity. Copyright (c) 2005 APA, all rights reserved.

Preliminary Support for a Generalized Arousal Model of Political Conservatism

PubMed Central

Tritt, Shona M.; Inzlicht, Michael; Peterson, Jordan B.

2013-01-01

It is widely held that negative emotions such as threat, anxiety, and disgust represent the core psychological factors that enhance conservative political beliefs. We put forward an alternative hypothesis: that conservatism is fundamentally motivated by arousal, and that, in this context, the effect of negative emotion is due to engaging intensely arousing states. Here we show that study participants agreed more with right but not left-wing political speeches after being exposed to positive as well as negative emotion-inducing film-clips. No such effect emerged for neutral-content videos. A follow-up study replicated and extended this effect. These results are consistent with the idea that emotional arousal, in general, and not negative valence, specifically, may underlie political conservatism. PMID:24376687

Comparing the Effects of Negative and Mixed Emotional Messages on Predicted Occasional Excessive Drinking

PubMed Central

Carrera, Pilar; Caballero, Amparo; Muñoz, Dolores

2008-01-01

In this work we present two types of emotional message, negative (sadness) versus mixed (joy and sadness), with the aim of studying their differential effect on attitude change and the probability estimated by participants of repeating the behavior of occasional excessive drinking in the near future. The results show that for the group of participants with moderate experience in this behavior the negative message, compared to the mixed one, is associated with higher probability of repeating the risk behavior and a less negative attitude toward it. These results suggest that mixed emotional messages (e.g. joy and sadness messages) could be more effective in campaigns for the prevention of this risk behavior. PMID:25977606

Superlensing effect for surface acoustic waves in a pillar-based phononic crystal with negative refractive index

DOE Office of Scientific and Technical Information (OSTI.GOV)

Addouche, Mahmoud, E-mail: mamoud.addouche@femto-st.fr; Al-Lethawe, Mohammed A., E-mail: mohammed.abdulridha@femto-st.fr; Choujaa, Abdelkrim, E-mail: achoujaa@femto-st.fr

2014-07-14

We demonstrate super resolution imaging for surface acoustic waves using a phononic structure displaying negative refractive index. This phononic structure is made of a monolithic square lattice of cylindrical pillars standing on a semi-infinite medium. The pillars act as acoustic resonator and induce a surface propagating wave with unusual dispersion. We found, under specific geometrical parameters, one propagating mode that exhibits negative refraction effect with negative effective index close to −1. Furthermore, a flat lens with finite number of pillars is designed to allow the focusing of an acoustic point source into an image with a resolution of (λ)/3 ,more » overcoming the Rayleigh diffraction limit.« less

Preliminary support for a generalized arousal model of political conservatism.

PubMed

Tritt, Shona M; Inzlicht, Michael; Peterson, Jordan B

2013-01-01

It is widely held that negative emotions such as threat, anxiety, and disgust represent the core psychological factors that enhance conservative political beliefs. We put forward an alternative hypothesis: that conservatism is fundamentally motivated by arousal, and that, in this context, the effect of negative emotion is due to engaging intensely arousing states. Here we show that study participants agreed more with right but not left-wing political speeches after being exposed to positive as well as negative emotion-inducing film-clips. No such effect emerged for neutral-content videos. A follow-up study replicated and extended this effect. These results are consistent with the idea that emotional arousal, in general, and not negative valence, specifically, may underlie political conservatism.

Negative Emotion Weakens the Degree of Self-Reference Effect: Evidence from ERPs

PubMed Central

Fan, Wei; Zhong, Yiping; Li, Jin; Yang, Zilu; Zhan, Youlong; Cai, Ronghua; Fu, Xiaolan

2016-01-01

We investigated the influence of negative emotion on the degree of self-reference effect using event-related potentials (ERPs). We presented emotional pictures and self-referential stimuli (stimuli that accelerate and improve processing and improve memory of information related to an individual’s self-concept) in sequence. Participants judged the color of the target stimulus (self-referential stimuli). ERP results showed that the target stimuli elicited larger P2 amplitudes under neutral conditions than under negative emotional conditions. Under neutral conditions, N2 amplitudes for highly self-relevant names (target stimulus) were smaller than those for any other names. Under negative emotional conditions, highly and moderately self-referential stimuli activated smaller N2 amplitudes. P3 amplitudes activated by self-referential processing under negative emotional conditions were smaller than neutral conditions. In the left and central sites, highly self-relevant names activated larger P3 amplitudes than any other names. But in the central sites, moderately self-relevant names activated larger P3 amplitudes than non-self-relevant names. The findings indicate that negative emotional processing could weaken the degree of self-reference effect. PMID:27733836

Mindfulness during romantic conflict moderates the impact of negative partner behaviors on cortisol responses.

PubMed

Laurent, Heidemarie K; Hertz, Robin; Nelson, Benjamin; Laurent, Sean M

2016-03-01

This study was designed to test whether romantic partners' mindfulness-present moment, nonjudgmental awareness-during a conflict discussion could buffer the effects of negative partner behaviors on neuroendocrine stress responses. Heterosexual couples (n=88 dyads) provided 5 saliva samples for cortisol assay during a laboratory session involving a conflict discussion task. Conflict behaviors were coded by outside observers using the System for Coding Interactions in Dyads, and partners rated their mindfulness during the task using the Toronto Mindfulness Scale. Interactions tested using multilevel modeling revealed that participants with higher levels of mindfulness during the conflict showed either quicker cortisol recovery or an absence of slowed recovery in the presence of more negative partner behaviors. Whereas the attitudinal component of mindfulness (curiosity) moderated effects of negative partner engagement in the conflict (i.e., attempts to control, coerciveness, negativity and conflict), the attentional component of mindfulness (decentering) moderated the effect of partner disengagement (i.e., withdrawal). These findings lend support to the idea that mindfulness during a stressful interaction can mitigate the physiological impacts of negative behaviors. Copyright © 2016 Elsevier Inc. All rights reserved.

Age-related emotional bias in processing two emotionally valenced tasks.

PubMed

Allen, Philip A; Lien, Mei-Ching; Jardin, Elliott

2017-01-01

Previous studies suggest that older adults process positive emotions more efficiently than negative emotions, whereas younger adults show the reverse effect. We examined whether this age-related difference in emotional bias still occurs when attention is engaged in two emotional tasks. We used a psychological refractory period paradigm and varied the emotional valence of Task 1 and Task 2. In both experiments, Task 1 was emotional face discrimination (happy vs. angry faces) and Task 2 was sound discrimination (laugh, punch, vs. cork pop in Experiment 1 and laugh vs. scream in Experiment 2). The backward emotional correspondence effect for positively and negatively valenced Task 2 on Task 1 was measured. In both experiments, younger adults showed a backward correspondence effect from a negatively valenced Task 2, suggesting parallel processing of negatively valenced stimuli. Older adults showed similar negativity bias in Experiment 2 with a more salient negative sound ("scream" relative to "punch"). These results are consistent with an arousal-bias competition model [Mather and Sutherland (Perspectives in Psychological Sciences 6:114-133, 2011)], suggesting that emotional arousal modulates top-down attentional control settings (emotional regulation) with age.

Individual differences in cognitive control over emotional material modulate cognitive biases linked to depressive symptoms.

PubMed

Everaert, Jonas; Grahek, Ivan; Koster, Ernst H W

2017-06-01

Deficient cognitive control over emotional material and cognitive biases are important mechanisms underlying depression, but the interplay between these emotionally distorted cognitive processes in relation to depressive symptoms is not well understood. This study investigated the relations among deficient cognitive control of emotional information (i.e. inhibition, shifting, and updating difficulties), cognitive biases (i.e. negative attention and interpretation biases), and depressive symptoms. Theory-driven indirect effect models were constructed, hypothesising that deficient cognitive control over emotional material predicts depressive symptoms through negative attention and interpretation biases. Bootstrapping analyses demonstrated that deficient inhibitory control over negative material was related to negative attention bias which in turn predicted a congruent bias in interpretation and subsequently depressive symptoms. Both shifting and updating impairments in response to negative material had an indirect effect on depression severity through negative interpretation bias. No evidence was found for direct effects of deficient cognitive control over emotional material on depressive symptoms. These findings may help to formulate an integrated understanding of the cognitive foundations of depressive symptoms.

Negative affect mediates the relationship between interpersonal problems and binge-eating disorder symptoms and psychopathology in a clinical sample: a test of the interpersonal model.

PubMed

Ivanova, Iryna V; Tasca, Giorgio A; Hammond, Nicole; Balfour, Louise; Ritchie, Kerri; Koszycki, Diana; Bissada, Hany

2015-03-01

This study evaluated the validity of the interpersonal model of binge-eating disorder (BED) psychopathology in a clinical sample of women with BED. Data from a cross-sectional sample of 255 women with BED were examined for the direct effects of interpersonal problems on BED symptoms and psychopathology, and indirect effects mediated by negative affect. Structural equation modelling analyses demonstrated that higher levels of interpersonal problems were associated with greater negative affect, and greater negative affect was associated with higher frequency of BED symptoms and psychopathology. There was a significant indirect effect of interpersonal problems on BED symptoms and psychopathology mediated through negative affect. Interpersonal problems may lead to greater BED symptoms and psychopathology, and this relationship may be partially explained by elevated negative affect. The results of the study are the first to provide support for the interpersonal model of BED symptoms and psychopathology in a clinical sample of women. Copyright © 2015 John Wiley & Sons, Ltd and Eating Disorders Association.

Relative Effectiveness of Reappraisal and Distraction in Regulating Emotion in Late-Life Depression

PubMed Central

Smoski, Moria J.; LaBar, Kevin S.; Steffens, David C.

2013-01-01

Objectives The present study compares the effectiveness of two strategies, reappraisal and distraction, in reducing negative affect in older adults induced by focusing on personally relevant negative events and stressors. Participants included 30 adults with MDD and 40 never-depressed (ND) comparison participants ages 60 and over (mean age = 69.7 years). Design and Measurements Participants underwent three affect induction trials, each followed by a different emotion regulation strategy: distraction, reappraisal, and a no-instruction control condition. Self-reported affect was recorded pre- and post-affect induction, and at one-minute intervals during regulation. Results Across groups, participants reported greater reductions in negative affect with distraction than reappraisal or the no-instruction control condition. An interaction between group and regulation condition indicated that distraction was more effective in reducing negative affect in the MDD group than the ND group. Conclusions These results suggest that distraction is an especially effective strategy for reducing negative affect in older adults with MDD. Finding ways to incorporate distraction skills into psychotherapeutic interventions for late-life MDD may improve their effectiveness, especially for short-term improvement of affect following rumination. PMID:24021222

Effects of Positive and Negative Adult-Child Interactions on Children's Social Preference

ERIC Educational Resources Information Center

Redd, William H.; And Others

1975-01-01

Studied the effects of positive and negative interaction on the performance of preschool and elementary school children and their preferences for the adults associated with each type of interaction. (Author/SDH)

Negative relationship behavior is more important than positive: Correlates of outcomes during stressful life events.

PubMed

Rivers, Alannah Shelby; Sanford, Keith

2018-04-01

When people who are married or cohabiting face stressful life situations, their ability to cope may be associated with two separate dimensions of interpersonal behavior: positive and negative. These behaviors can be assessed with the Couple Resilience Inventory (CRI). It was expected that scales on this instrument would correlate with outcome variables regarding life well-being, stress, and relationship satisfaction. It was also expected that effects for negative behavior would be larger than effects for positive and that the effects might be curvilinear. Study 1 included 325 married or cohabiting people currently experiencing nonmedical major life stressors and Study 2 included 154 married or cohabiting people with current, serious medical conditions. All participants completed an online questionnaire including the CRI along with an alternate measure of couple behavior (to confirm scale validity), a measure of general coping style (to serve as a covariate), and measures of outcome variables regarding well-being, quality of life, perceived stress, and relationship satisfaction. The effects for negative behavior were larger than effects for positive in predicting most outcomes, and many effects were curvilinear. Notably, results remained significant after controlling for general coping style, and scales measuring positive and negative behavior demonstrated comparable levels of validity. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

The effect of physical activity on sleep quality, well-being, and affect in academic stress periods.

PubMed

Wunsch, Kathrin; Kasten, Nadine; Fuchs, Reinhard

2017-01-01

The stress-buffering hypothesis postulates that physical activity and exercise can buffer the negative effects of (academic) stress on health. It still remains an open question whether students, who regularly engage in physical activity and exercise within their academic examination period, can successfully diminish these negative effects. Sixty-four subjects participated in this study and completed a total of five surveys, with T1 at the end of the semester break (baseline) and T2-T5 being presented every Friday in the last 4 weeks of the semester (examination period). They were asked to answer questions about their activity level, sleep quality, well-being and affect. Hierarchical linear models showed significant dependencies on time for all dependent measures. The expansion of the model for exercise also showed significant main effects of this predictor on well-being and positive affect (PA) and negative affect. Moreover, significant interactions with time for sleep quality and PA were found. Results suggest that physical activity and exercise in the academic examination period may be able to buffer the negative effects of stress on health-related outcomes. Therefore, activity levels should be maintained in times of high stress to prevent negative effects on sleep, well-being and affect in students.

Effects of mood induction on consumers with vs. without compulsive buying propensity: an experimental study.

PubMed

Vogt, Sinje; Hunger, Antje; Türpe, Tina; Pietrowsky, Reinhard; Gerlach, Alexander L

2014-12-15

Compulsive buying (CB) is excessive and leads to impairment and distress. Several studies aimed to explore the phenomenology and antecedents of CB, especially affective states. However, these studies mostly used retrospective self-report and mostly focused on compulsive buyers only. Therefore, this study aims to directly compare consumers with CB propensity and controls on experimental proxies of buying behavior and to investigate 1) effects of neutral vs. negative mood inductions and 2) whether mood effects on buying behavior are specific to CB. Forty female consumers with CB propensity and 40 female controls were randomly assigned to a neutral or negative mood induction. Buying related behavior (likelihood to expose oneself to a shopping situation, urge and probability to buy, willingness to pay) was assessed. Consumers with CB propensity differed from controls in all buying behavior aspects except for willingness to pay. Neither main effects of mood nor group×mood interaction effects on buying behavior were found. However, consumers with CB propensity were emotionally more strongly affected by a negative mood induction. Although negative affect has previously been reported to precede buying episodes in CB, our findings do not indicate specific negative mood effects on buying, neither in CB nor in controls. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Brain potentials associated with the outcome processing in framing effects.

PubMed

Ma, Qingguo; Feng, Yandong; Xu, Qing; Bian, Jun; Tang, Huixian

2012-10-24

Framing effect is a cognitive bias referring to the phenomenon that people respond differently to different but objectively equivalent descriptions of the same problem. By measuring event-related potentials, the present study aimed to investigate the neural mechanisms underlying the framing effect, especially how the negative and positive frames influence the outcome processing in our brain. Participants were presented directly with outcomes framed either positively in terms of lives saved or negatively in terms of lives lost in large and small group conditions, and were asked to rate the favorableness of each of them. The behavioral results showed that the framing effect occurred in both group size conditions, with more favorable evaluations associated with positive framing. Compared with outcomes in positive framing condition, a significant feedback-related negativity (FRN) effect was elicited by outcomes in negative framing condition, even though the outcomes in different conditions were objectively equivalent. The results are explained in terms of the associative model of attribute framing effect which states that attribute framing effect occurs as a result of a valence-based associative processing. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

Positive Attributes Buffer the Negative Associations Between Low Intelligence and High Psychopathology With Educational Outcomes.

PubMed

Hoffmann, Mauricio Scopel; Leibenluft, Ellen; Stringaris, Argyris; Laporte, Paola Paganella; Pan, Pedro Mario; Gadelha, Ary; Manfro, Gisele Gus; Miguel, Eurípedes Constantino; Rohde, Luis Augusto; Salum, Giovanni Abrahão

2016-01-01

This study examines the extent to which children's positive attributes are distinct from psychopathology. We also investigate whether positive attributes change or "buffer" the impact of low intelligence and high psychopathology on negative educational outcomes. In a community sample of 2,240 children (6-14 years of age), we investigated associations among positive attributes, psychopathology, intelligence, and negative educational outcomes. Negative educational outcomes were operationalized as learning problems and poor academic performance. We tested the discriminant validity of psychopathology versus positive attributes using confirmatory factor analysis (CFA) and propensity score matching analysis (PSM), and used generalized estimating equations (GEE) models to test main effects and interactions among predictors of educational outcomes. According to both CFA and PSM, positive attributes and psychiatric symptoms were distinct constructs. Positive attributes were associated with lower levels of negative educational outcomes, independent of intelligence and psychopathology. Positive attributes buffer the negative effects of lower intelligence on learning problems, and higher psychopathology on poor academic performance. Children's positive attributes are associated with lower levels of negative school outcomes. Positive attributes act both independently and by modifying the negative effects of low intelligence and high psychiatric symptoms on educational outcomes. Subsequent research should test interventions designed to foster the development of positive attributes in children at high risk for educational problems. Copyright © 2016 American Academy of Child and Adolescent Psychiatry. All rights reserved.

Positive Attributes Buffer the Negative Associations Between Low Intelligence and High Psychopathology With Educational Outcomes

PubMed Central

Hoffmann, Mauricio Scopel; Leibenluft, Ellen; Stringaris, Argyris; Laporte, Paola Paganella; Pan, Pedro Mario; Gadelha, Ary; Manfro, Gisele Gus; Miguel, Eurípedes Constantino; Rohde, Luis Augusto; Salum, Giovanni Abrahão

2016-01-01

Objective This study examines the extent to which children’s positive attributes are distinct from psychopathology. We also investigate whether positive attributes change or “buffer” the impact of low intelligence and high psychopathology on negative educational outcomes. Method In a community sample of 2,240 children (6–14 years of age), we investigated associations among positive attributes, psychopathology, intelligence, and negative educational outcomes. Negative educational outcomes were operationalized as learning problems and poor academic performance. We tested the discriminant validity of psychopathology versus positive attributes using confirmatory factor analysis (CFA) and propensity score matching analysis (PSM), and used generalized estimating equations (GEE) models to test main effects and interactions among predictors of educational outcomes. Results According to both CFA and PSM, positive attributes and psychiatric symptoms were distinct constructs. Positive attributes were associated with lower levels of negative educational outcomes, independent of intelligence and psychopathology. Positive attributes buffer the negative effects of lower intelligence on learning problems, and higher psychopathology on poor academic performance. Conclusion Children’s positive attributes are associated with lower levels of negative school outcomes. Positive attributes act both independently and by modifying the negative effects of low intelligence and high psychiatric symptoms on educational outcomes. Subsequent research should test interventions designed to foster the development of positive attributes in children at high risk for educational problems. PMID:26703909

Prospective Investigation of the Contrast Avoidance Model of Generalized Anxiety and Worry.

PubMed

Crouch, Tara A; Lewis, Jamie A; Erickson, Thane M; Newman, Michelle G

2017-07-01

The factors that maintain generalized anxiety disorder (GAD) symptoms and worry over time are not entirely clear. The Contrast Avoidance Model (CAM) postulates that individuals at risk for pathological worry and GAD symptoms uniquely fear emotional shifts from neutral or positive emotions into negative emotional states, and consequently use worry to maintain negative emotion in order to avoid shifts or blunt the effect of negative contrasts. This model has received support in laboratory experiments, but has not been investigated prospectively in the naturalistic context of daily life. The present study tested the CAM in a longitudinal experience sampling study with a subclinical sample. Participants selected to represent a broad range of symptoms (N = 92) completed baseline measures of GAD and depression symptoms, and eight weekly assessments of worry, experiences of negative emotional contrasts during their worst event of the week, and situation-specific negative emotion. Consistent with the CAM, GAD symptoms prospectively predicted higher endorsement of negative contrast experiences as worst events, independent of depression symptoms. Unsurprisingly, higher negative contrasts predicted higher negative emotion. However, both higher baseline GAD symptoms and weekly worry uniquely moderated (reduced) this relationship, providing consistent support for the idea that worry may blunt the emotional effects of contrasts. Depression symptoms did not have the same moderating effect. These findings support the CAM in an ecologically valid context. Copyright © 2016. Published by Elsevier Ltd.

Minimum Wages and Skill Acquisition: Another Look at Schooling Effects.

ERIC Educational Resources Information Center

Neumark, David; Wascher, William

2003-01-01

Examines the effects of minimum wage on schooling, seeking to reconcile some of the contradictory results in recent research using Current Population Survey data from the late 1970s through the 1980s. Findings point to negative effects of minimum wages on school enrollment, bolstering the findings of negative effects of minimum wages on enrollment…

Testing the effects of suppression and reappraisal on emotional concordance using a multivariate multilevel model.

PubMed

Butler, Emily A; Gross, James J; Barnard, Kobus

2014-04-01

In theory, the essence of emotion is coordination across experiential, behavioral, and physiological systems in the service of functional responding to environmental demands. However, people often regulate emotions, which could either reduce or enhance cross-system concordance. The present study tested the effects of two forms of emotion regulation (expressive suppression, positive reappraisal) on concordance of subjective experience (positive-negative valence), expressive behavior (positive and negative), and physiology (inter-beat interval, skin conductance, blood pressure) during conversations between unacquainted young women. As predicted, participants asked to suppress showed reduced concordance for both positive and negative emotions. Reappraisal instructions also reduced concordance for negative emotions, but increased concordance for positive ones. Both regulation strategies had contagious interpersonal effects on average levels of responding. Suppression reduced overall expression for both regulating and uninstructed partners, while reappraisal reduced negative experience. Neither strategy influenced the uninstructed partners' concordance. These results suggest that emotion regulation impacts concordance by altering the temporal coupling of phasic subsystem responses, rather than by having divergent effects on subsystem tonic levels. Copyright © 2013 Elsevier B.V. All rights reserved.

Unusual negative permeability of single magnetic nanowire excited by the spin transfer torque effect

NASA Astrophysics Data System (ADS)

Han, Mangui; Zhou, Wu

2018-07-01

Due to the effect of spin transfer torque, negative imaginary parts of permeability (μ″ < 0) are reported in a ferromagnetic nanowire. It is found that negative μ″ values are resulted from the interaction of spin polarized conduction electrons with the spatially non-uniform distributed magnetic moments at both ends of nanowires. The results are well explained from the effect of spin transfer torque on the precession of magnetization under the excitation of both the pulsed magnetic field and static electric field.

Lights … action: Comparison of trauma films for use in the trauma film paradigm.

PubMed

Arnaudova, Inna; Hagenaars, Muriel A

2017-06-01

Affective films are often used in emotion research and negative films are frequently used as an analogue for trauma (trauma film paradigm). However, different films are used with possibly distinct consequences. We aimed to investigate specific effects of four negative films covering distinct themes (physical, sexual, traffic and food), and tested neutral and positive films with matching content. Self-reported emotional responses and heart rate during the films were examined (immediate responses) as well as intrusions of the films in the subsequent week (delayed responses). Within each theme, negative films were rated as more unpleasant than the positive and neutral counterparts. They also evoked more negative emotions and more intrusive memories. Across themes, the four negative films did not differ in terms of valence and arousal, but clearly differed on immediate (e.g., disgust, embarrassment, heart rate) and delayed (intrusions) effects. Thus, we urge researchers to carefully select negative films for their studies, as different films seem to evoke distinct emotional responses. In addition, using positive films within the same themes is recommended in order to control for effects of arousal. In general, the specific film material should be considered when comparing effects across studies. Copyright © 2017 Elsevier Ltd. All rights reserved.