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1.
Article in English | MEDLINE | ID: mdl-38886995

ABSTRACT

OBJECTIVE: This case study describes how an All of Us engagement project returned value to community by strengthening high school students' capacity to serve as health advocates. MATERIALS AND METHODS: Project activities included health literacy education and research projects on the influence of environmental, societal, and lifestyle factors on community health disparities. The research project involved use of the Photovoice method and All of Us data. At project's end, students presented their research to the community. RESULTS: The project's success was measured by students' participation in the research poster session and comparison of pre- and post-project scores from the Health Literacy Assessment Scale for Adolescent. Data analysis suggests the project succeeded in meeting its goal of increasing students' health literacy. DISCUSSION AND CONCLUSION: Through education and research activities, students learned about community health issues and the importance of participation in medical research programs, like All of Us, to address issues.

2.
Eur J Pharmacol ; 744: 76-82, 2014 Dec 05.
Article in English | MEDLINE | ID: mdl-25281837

ABSTRACT

(-)-Epicatechin (EPI) is cardioprotective in the setting of ischemia/reperfusion (IR) injury and doxycycline (DOX) is known to preserve cardiac structure/function after myocardial infarction (MI). The main objective of this study was to examine the effects of EPI and DOX co-administration on MI size after IR injury and to determine if cardioprotection may involve the mitigation of mitochondrial swelling. For this purpose, a rat model of IR was used. Animals were subjected to a temporary 45 min occlusion of the left anterior descending coronary artery. Treatment consisted of a single or double dose of EPI (10 mg/kg) combined with DOX (5 mg/kg). The first dose was given 15 min prior to reperfusion and the second 12 h post-MI. The effects of EPI +/- DOX on mitochondrial swelling (i.e. mPTP opening) were determined using isolated mitochondria exposed to calcium overload and data examined using isobolographic analysis. To ascertain for the specificity of EPI effects on mitochondrial swelling other flavonoids were also evaluated. Single dose treatment reduced MI size by ~46% at 48 h and 44% at three weeks. Double dosing evidenced a synergistic, 82% reduction at 3 weeks. EPI plus DOX also inhibited mitochondrial swelling in a synergic manner thus, possibly accounting for the cardioprotective effects whereas limited efficacy was observed with the other flavonoids. Given the apparent lack of toxicity in humans, the combination of EPI and DOX may have clinical potential for the treatment of myocardial IR injury.


Subject(s)
Catechin/pharmacology , Doxycycline/pharmacology , Flavonoids/pharmacology , Mitochondrial Swelling/drug effects , Myocardial Infarction/drug therapy , Reperfusion Injury/drug therapy , Animals , Cardiotonic Agents/pharmacology , Coronary Vessels/drug effects , Drug Synergism , Male , Mitochondria, Heart/drug effects , Myocardial Reperfusion Injury/drug therapy , Rats , Rats, Sprague-Dawley
3.
Int J Cardiol ; 175(2): 297-306, 2014 Aug 01.
Article in English | MEDLINE | ID: mdl-24908200

ABSTRACT

BACKGROUND: Targeting the mitochondria during ischemia/reperfusion (IR) can confer cardioprotection leading to improved clinical outcomes. The cardioprotective potential of (-)-epicatechin (EPI) during IR via modulation of mitochondrial function was evaluated. METHODS AND RESULTS: Ischemia was induced in rats via a 45 min occlusion of the left anterior descending coronary artery followed by 1 h, 48 h, or 3 week reperfusion. EPI (10 mg/kg) was administered IV 15 min prior to reperfusion for the single dose group and again 12 h later for the double dose group. Controls received water. Experiments also utilized cultured neonatal rat ventricular myocytes (NRVM) and myoblasts. A single dose of EPI reduced infarct size by 27% at 48 h and 28% at 3 week. Double dose treatment further decreased infarct size by 80% at 48 h, and 52% by 3 weeks. The protective effect of EPI on mitochondrial function was evident after 1h of reperfusion when mitochondria demonstrated less respiratory inhibition, lower mitochondrial Ca2+ load, and a preserved pool of NADH that correlated with higher tissue ATP levels. Mechanistic studies in NRVM revealed that EPI acutely stimulated maximal rates of respiration, an effect that was blocked by inhibitors of the mitochondrial pyruvate carrier, nitric oxide synthase, or soluble guanylyl cyclase. In myoblasts, knockdown of components of the mitochondrial pyruvate carrier blocked EPI-induced respiratory stimulation. CONCLUSIONS: IV EPI confers cardioprotection via preservation of mitochondrial function potentially through enhanced substrate provision. These provocative results document a novel mechanism of a natural product with potential clinical utility.


Subject(s)
Cardiotonic Agents/administration & dosage , Catechin/administration & dosage , Mitochondria, Heart/drug effects , Mitochondria, Heart/physiology , Myocardial Reperfusion Injury/metabolism , Myocardial Reperfusion Injury/prevention & control , Animals , Animals, Newborn , Cells, Cultured , Dose-Response Relationship, Drug , Infusions, Intravenous , Male , Myocardial Reperfusion Injury/physiopathology , Rats , Rats, Sprague-Dawley
4.
J Cardiovasc Transl Res ; 5(6): 805-13, 2012 Dec.
Article in English | MEDLINE | ID: mdl-23054657

ABSTRACT

Cardiac fibroblasts (CFs) are involved in maintaining extracellular matrix (ECM) homeostasis in the heart. CFs mediate responses to hormonal and mechanical stimuli and relay these to other local cell types through release of autocrine and/or paracrine factors. CFs also play important roles in the setting of injury, i.e., myocardial infarction, where ECM production is key to efficient scarring. However, conditions exist in which excess production of ECM by CFs can lead to cardiac fibrosis. Two important pathways known to be involved in development of cardiac fibrosis are renin-angiotensin system (RAS) and advanced glycation end products (AGE) receptor (RAGE) signaling cascades. This report summarizes actions of these two pathways on function of CFs. Because cardiac fibrosis is an important component of diabetic cardiomyopathy, we include new data that suggests a possible crosstalk between the RAS and AGE/RAGE pathway in order to activate CFs in diabetes.


Subject(s)
Diabetic Cardiomyopathies/metabolism , Fibroblasts/metabolism , Glycation End Products, Advanced/metabolism , Myocardium/metabolism , Receptor Cross-Talk , Receptors, Immunologic/metabolism , Renin-Angiotensin System , Signal Transduction , Animals , Diabetic Cardiomyopathies/pathology , Extracellular Matrix/metabolism , Fibroblasts/pathology , Fibrosis , Humans , Myocardium/pathology , Receptor for Advanced Glycation End Products
5.
Am J Physiol Heart Circ Physiol ; 302(7): H1387-93, 2012 Apr 01.
Article in English | MEDLINE | ID: mdl-22268115

ABSTRACT

Poorly synchronized activation of the ventricles can lead to impairment of normal cardiac structure/function. We reported previously that short term (4 h) left ventricular (LV) pacing-induced ventricular dyskinesis led to an inflammatory response localized to the epicardium. Results from this study demonstrated that neutrophils may play a major role in this inflammatory process. Neutrophil recruitment to a site of injury is a process that is highly dependent on an upregulation of cell adhesion molecules (CAM). The dependence of ventricular dysynchrony-induced inflammatory responses on CAM upregulation has not been explored. To gain further insight, we used a mouse model of LV pacing to evaluate the role of CAM in mediating the inflammatory response associated with ventricular dyskinesis. We first examined the effects of LV pacing in wild-type mice. Results demonstrate that 40 min of LV pacing increases ICAM-1 immunostaining as well as myeloperoxidase activity and tissue oxidative stress by twofold in early-activated myocardium. Matrix metalloproteinase-9 activity also increased in the same region by ∼3.5-fold. To determine the role of CAM, mice null for ICAM-1 or p-selectin were subjected to 40 min LV pacing. Results demonstrate that the inflammatory response seen in the wild-type mice was significantly mitigated in the ICAM-1 and p-selectin null mice. In conclusion, results demonstrate that CAM expression plays a critical role in the triggering of LV pacing-induced inflammation, thus providing evidence of a vascular mechanism underlying this response. The mechanisms that trigger an upregulation of myocardial CAM expression and, therefore, inflammation await further investigation since they suggest a specific involvement of vascular events.


Subject(s)
Cardiac Pacing, Artificial/adverse effects , Cell Adhesion Molecules/physiology , Myocarditis/physiopathology , Animals , Cell Adhesion Molecules/genetics , Data Interpretation, Statistical , Electrocardiography , Electrodes, Implanted , Glutathione/metabolism , Immunohistochemistry , In Vitro Techniques , Intercellular Adhesion Molecule-1/genetics , Intercellular Adhesion Molecule-1/physiology , Mice , Mice, Inbred C57BL , Mice, Knockout , P-Selectin/genetics , P-Selectin/physiology , Peroxidase/metabolism , Ventricular Function, Left/physiology
6.
Am J Physiol Heart Circ Physiol ; 300(4): H1282-90, 2011 Apr.
Article in English | MEDLINE | ID: mdl-21297025

ABSTRACT

Perturbations in the normal sequence of ventricular activation can create regions of early and late activation, leading to dysynchronous contraction and areas of dyskinesis. Dyskinesis occurs across the left ventricular (LV) wall, and its presence may have important consequences on cardiac structure and function in normal and failing hearts. Acutely, dyskinesis can trigger inflammation and, in the long term (6 wk and above), leads to LV remodeling. The mechanisms that trigger these changes are unknown. To gain further insight, we used a canine model to evaluate transumural changes in myocardial function and inflammation induced by epicardial LV pacing. The results indicate that 4 h of LV suprathreshold pacing resulted in a 30% local loss of endocardial thickening. Assessment of neutrophil infiltration showed a significant approximately fivefold increase in myeloperoxidase activity in the epicardium versus the midwall/endocardium. Matrix metalloproteinase-9 activity increased ∼2 fold in the epicardium and ROS generation increased ∼2.5-fold compared with the midwall/endocardium. To determine the effects that electrical current alone has on these end points, a group of animals was subjected to subthreshold pacing. Significant increases were observed only in epicardial myeloperoxidase levels. Thus, the results indicate that transmural dyskinesis induced by suprathreshold epicardial LV activation triggers a localized epicardial inflammatory response, whereas subthreshold stimulation appears to solely induce the trapping of leucocytes. Suprathreshold pacing also induces a loss of endocardial function. These results may have important implications as to the nature of the mechanisms that trigger the inflammatory response and possibly long-term remodeling in the setting of dysynchrony.


Subject(s)
Cardiac Pacing, Artificial/methods , Myocardial Contraction/physiology , Pericarditis/enzymology , Animals , Dogs , Male , Matrix Metalloproteinase 9/biosynthesis , Neutrophil Infiltration/physiology , Peroxidase/biosynthesis , Reactive Oxygen Species/metabolism , Ventricular Function, Left/physiology
7.
J Am Coll Cardiol ; 55(25): 2869-76, 2010 Jun 22.
Article in English | MEDLINE | ID: mdl-20579545

ABSTRACT

OBJECTIVES: We examined the effects of the flavanol (-)-epicatechin on short- and long-term infarct size and left ventricular (LV) structure and function after permanent coronary occlusion (PCO) and the potential involvement of the protective protein kinase B (AKT)/extracellular signal-related kinase (ERK) signaling pathways. BACKGROUND: (-)-epicatechin reduces blood pressure in hypertensive patients and limits infarct size in animal models of myocardial ischemia-reperfusion injury. However, nothing is known about its effects on infarction after PCO. METHODS: (-)-epicatechin (1 mg/kg daily) treatment was administered via oral gavage to 250 g male rats for 10 days before PCO and was continued afterward. The PCO controls received water. Sham animals underwent thoracotomy and treatment in the absence of PCO. Immunoblots assessed AKT/ERK involvement 2 h after PCO. The LV morphometric features and function were measured 48 h and 3 weeks after PCO. RESULTS: In the 48-h group, treatment reduced infarct size by 52%. There were no differences in hemodynamics among the different groups (heart rate and aortic and LV pressures). Western blots revealed no differences in AKT or ERK phosphorylation levels. At 3 weeks, PCO control animals demonstrated significant increases in LV end-diastolic pressure, heart and body weight, and LV chamber diameter versus sham. The PCO plus (-)-epicatechin group values were comparable with those of the sham plus (-)-epicatechin group. Treatment resulted in a 33% decrease in myocardial infarction size. The LV pressure-volume curves demonstrated a right shift in control PCO animals, whereas the (-)-epicatechin curves were comparable with those of the sham group. The LV scar area strains were significantly improved with (-)-epicatechin. CONCLUSIONS: These results demonstrate the unique capacity of (-)-epicatechin to confer cardioprotection in the setting of a severe form of myocardial ischemic injury. Protection is sustained over time and preserves LV structure and function. The cardioprotective mechanism(s) of (-)-epicatechin seem to be unrelated to AKT or ERK activation. (-)-epicatechin warrants further investigation as a cardioprotectant.


Subject(s)
Catechin/pharmacology , Coronary Occlusion/drug therapy , Hemodynamics/physiology , Myocardial Infarction/drug therapy , Myocardial Infarction/prevention & control , Ventricular Remodeling/drug effects , Administration, Oral , Analysis of Variance , Animals , Coronary Circulation , Coronary Occlusion/diagnostic imaging , Coronary Occlusion/mortality , Disease Models, Animal , Male , Myocardial Infarction/mortality , Myocardial Infarction/pathology , Myocardial Reperfusion Injury/prevention & control , Probability , Radiography , Random Allocation , Rats , Rats, Sprague-Dawley , Reference Values , Survival Rate , Treatment Outcome , Ventricular Remodeling/physiology
8.
Am J Physiol Heart Circ Physiol ; 295(2): H761-7, 2008 Aug.
Article in English | MEDLINE | ID: mdl-18567705

ABSTRACT

Epidemiological studies have shown a correlation between flavonoid-rich diets and improved cardiovascular prognosis. Cocoa contains large amounts of flavonoids, in particular flavanols (mostly catechins and epicatechins). Flavonoids possess pleiotropic properties that may confer protective effects to tissues during injury. We examined the ability of epicatechin to reduce short-and long-term ischemia-reperfusion (I/R) myocardial injury. Epicatechin (1 mg.kg(-1).day(-1)) pretreatment (Tx) was administered daily via oral gavage to male rats for 2 or 10 days. Controls received water. Ischemia was induced via a 45-min coronary occlusion. Reperfusion was allowed until 48 h or 3 wk while Tx continued. We measured infarct (MI) size (%), hemodynamics, myeloperoxidase activity, tissue oxidative stress, and matrix metalloproteinase-9 (MMP-9) activity in 48-h groups. Cardiac morphometry was also evaluated in 3-wk groups. With 2 days of Tx, no reductions in MI size occurred. After 10 days, a significant approximately 50% reduction in MI size occurred. Epicatechin rats demonstrated no significant changes in hemodynamics. Tissue oxidative stress was reduced significantly in the epicatechin group vs. controls. MMP-9 activity demonstrated limited increases in the infarct region with epicatechin. By 3 wk, a significant 32% reduction in infarct size was observed with Tx, accompanied with sustained hemodynamics and preserved chamber morphometry. In conclusion, epicatechin Tx confers cardioprotection in the setting of I/R injury. The effects are independent of changes in hemodynamics, are sustained over time, and are accompanied by reduced levels of indicators of tissue injury. Results warrant the evaluation of cocoa flavanols as possible therapeutic agents to limit ischemic injury.


Subject(s)
Cardiovascular Agents/pharmacology , Catechin/pharmacology , Myocardial Infarction/prevention & control , Myocardial Reperfusion Injury/prevention & control , Myocardium/pathology , Administration, Oral , Animals , Cardiovascular Agents/administration & dosage , Catechin/administration & dosage , Disease Models, Animal , Drug Administration Schedule , Hemodynamics/drug effects , Male , Matrix Metalloproteinase 2/metabolism , Matrix Metalloproteinase 9/metabolism , Myocardial Infarction/pathology , Myocardial Infarction/physiopathology , Myocardial Reperfusion Injury/pathology , Myocardial Reperfusion Injury/physiopathology , Myocardium/enzymology , Oxidative Stress/drug effects , Peroxidase/metabolism , Rats , Rats, Sprague-Dawley , Time Factors
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