Calpain inhibition decreases oxidative stress via mitochondrial regulation in a swine model of chronic myocardial ischemia.

INTRODUCTION: Calpain overexpression is implicated in mitochondrial damage leading to tissue oxidative stress and myocardial ischemic injury. The aim of this study was to determine the effects of calpain inhibition (CI) on mitochondrial impairment and oxidative stress in a swine model of chronic myocardial ischemia and metabolic syndrome. METHODS: Yorkshire swine were fed a high-fat diet for 4 weeks to induce metabolic syndrome then underwent placement of an ameroid constrictor to the left circumflex artery. Three weeks later, animals received: no drug (control, "CON"; n= 7); a low-dose calpain inhibitor (0.12 mg/kg; "LCI", n= 7); or high-dose calpain inhibitor (0.25 mg/kg; "HCI", n=7). Treatment continued for 5 weeks, followed by tissue harvest. Cardiac tissue was assayed for protein carbonyl content, as well as antioxidant and mitochondrial protein expression. Reactive oxygen species (ROS) and mitochondrial respiration was measured in H9c2 cells following exposure to normoxia or hypoxia (1%) for 24 h with or without CI. RESULTS: In ischemic myocardial tissue, CI was associated with decreased total oxidative stress compared to control. CI was also associated with increased expression of mitochondrial proteins superoxide dismutase 1, SDHA, and pyruvate dehydrogenase compared to control. 100 nM of calpain inhibitor decreased ROS levels and respiration in both normoxic and hypoxic H9c2 cardiomyoblasts. CONCLUSIONS: In the setting of metabolic syndrome, CI improves oxidative stress in chronically ischemic myocardial tissue. Decreased oxidative stress may be via modulation of mitochondrial proteins involved in free radical scavenging and production.

Extracellular vesicle therapy attenuates antiangiogenic signaling in ischemic myocardium of swine with metabolic syndrome.

OBJECTIVE: Our recent studies using a porcine model of metabolic syndrome (MS) and chronic myocardial ischemia show that extracellular vesicle (EV) therapy improves blood flow and arteriogenesis in ischemic myocardium, although mechanisms of these changes are unclear. We hypothesized that in the setting of MS, EV therapy would decrease antiangiogenic signaling to mediate increased blood flow to chronically ischemic myocardium. METHODS: Yorkshire swine were fed a high-fat diet for 4 weeks to induce MS, then underwent placement of an ameroid constrictor to the left circumflex artery to induce chronic myocardial ischemia. Two weeks later, pigs underwent intramyocardial injection of vehicle (control, n = 6) or human bone marrow-derived EVs (n = 8). Five weeks later, left ventricular myocardium in ischemic territory was harvested. Protein expression was measured using immunoblot analysis, and data were analyzed using Wilcoxon rank sum test. Myocardial perfusion was measured with isotope-labeled microspheres, and correlation data were analyzed using Spearman rank correlation coefficient. RESULTS: EV treatment was associated with decreased expression of antiangiogenic proteins, angiostatin (P < .001) and endostatin (P = .043) in ischemic myocardium compared with control. In EV-treated pigs, there was a negative correlation between blood flow to ischemic myocardium and angiostatin (rs = -0.76; P = .037), but not endostatin expression (rs = .02; P = .98). EV treatment was also associated with decreased cathepsin D, which cleaves precursors to produce angiostatin and endostatin, in ischemic myocardium (P = .020). CONCLUSIONS: In the setting of MS and chronic myocardial ischemia, EV therapy is associated with decreased expression of antiangiogenic proteins, which might contribute to increased blood flow to chronically ischemic myocardium.

Extracellular vesicles modulate inflammatory signaling in chronically ischemic myocardium of swine with metabolic syndrome.

OBJECTIVE: Extracellular vesicle (EV) therapy has been shown to mitigate inflammation in animal models of acute myocardial ischemia/reperfusion. This study evaluates the effect of EV therapy on inflammatory signaling in a porcine model of chronic myocardial ischemia and metabolic syndrome. METHODS: Yorkshire swine were fed a high-cholesterol diet for 4 weeks to induce metabolic syndrome, then underwent placement of an ameroid constrictor to the left circumflex artery to induce chronic myocardial ischemia. Two weeks later, pigs received intramyocardial injection of either saline (control) (n = 6) or EVs (n = 8). Five weeks later, pigs were put to death and left ventricular myocardial tissue in ischemic and nonischemic territories were harvested. Protein expression was measured with immunoblotting, and macrophage count was determined by immunofluorescent staining of cluster of differentiation 68. Data were statistically analyzed via Wilcoxon rank-sum test. RESULTS: EV treatment was associated with decreased expression of proinflammatory markers nuclear factor kappa B (P = .002), pro-interleukin (IL) 1ß (P = .020), and cluster of differentiation 11c (P = .001) in ischemic myocardium, and decreased expression of nuclear factor kappa B in nonischemic myocardium (P = .03) compared with control. EV treatment was associated with increased expression of anti-inflammatory markers IL-10 (P = .020) and cluster of differentiation 163 (P = .043) in ischemic myocardium compared with control. There were no significant differences in expression of IL-6, tumor necrosis factor alpha, arginase, HLA class II histocompatibility antigen DR alpha chain, nuclear factor of kappa light polypeptide gene enhancer in B-cells inhibitor alpha, or phosphorylated nuclear factor of kappa light polypeptide gene enhancer in B-cells inhibitor alpha in ischemic myocardium or pro-IL1ß, IL-6, tumor necrosis factor alpha, IL-10, or nuclear factor of kappa light polypeptide gene enhancer in B-cells inhibitor alpha in nonischemic myocardium of EV-treated pigs compared with control. There were no differences in macrophage count in ischemic myocardium between EV-treated pigs and control. CONCLUSIONS: In the setting of metabolic syndrome and chronic myocardial ischemia, intramyocardial EV therapy attenuates proinflammatory signaling.

Glycemic control is not associated with neurocognitive decline after cardiac surgery.

BACKGROUND: Whether perioperative glycemic control is associated with neurocognitive decline (NCD) after cardiac surgery was examined. METHODS: Thirty patients undergoing cardiac surgery utilizing cardiopulmonary bypass (CPB) were screened for NCD preoperatively and on postoperative day 4 (POD4). Indices of glucose control were examined. Serum cytokine levels were measured and human transcriptome analysis was performed on blood samples. Neurocognitive data are presented as a change from baseline to POD4 in a score standardized with respect to age and gender. RESULTS: A decline in neurocognitive function was identified in 73% (22/30) of patients on POD4. There was no difference in neurocognitive function between patients with elevated HbA1c levels preoperatively (p = .973) or elevated fasting blood glucose levels the morning of surgery (>126 mg/dl, p = .910), or a higher maximum blood glucose levels during CPB (>180 mg/dl, p = .252), or higher average glucose levels during CPB (>160 mg/dl, p = .639). Patients with postoperative leukocytosis (WBC ≥ 10.5) had more NCD when compared to their baseline function (p = .03). Patients with elevated IL-8 levels at 6 h postoperatively had a significant decline in NCD at POD4 (p = .04). Human transcriptome analysis demonstrated unique and differential patterns of gene expression in patients depending on the presence of DM and NCD. CONCLUSIONS: Perioperative glycemic control does not have an effect on NCD soon after cardiac surgery. The profile of gene expression was altered in patients with NCD with or without diabetes.

Effects of High Fat Versus Normal Diet on Extracellular Vesicle-Induced Angiogenesis in a Swine Model of Chronic Myocardial Ischemia.

Background Mesenchymal stem cell-derived extracellular vesicles (EVs) promote angiogenesis in the ischemic myocardium. This study examines the difference in vascular density, myocardial perfusion, molecular signaling, and gene expression between normal diet (ND) and high fat diet (HFD) groups at baseline and following intramyocardial injection of EVs. Methods and Results Intact male Yorkshire swine fed either an ND (n=17) or HFD (n=14) underwent placement of an ameroid constrictor on the left circumflex coronary artery. Subsequently, animals received either intramyocardial injection of vehicle-saline as controls; (ND-controls n=7, HFD-controls, n=6) or EVs; (ND-EVs n=10, HFD-EVs n=8) into the ischemic territory. Five weeks later, myocardial function, perfusion, vascular density, cell signaling, and gene expression were examined. EVs improved indices of myocardial contractile function, myocardial perfusion, and arteriogenesis in both dietary cohorts. Interestingly, quantification of alpha smooth muscle actin demonstrated higher basal arteriolar density in HFD swine compared with their ND counterparts; whereas EVs were associated with increased CD31-labeled endothelial cell density only in the ND tissue, which approached significance. Levels of total endothelial nitric oxide synthase, FOXO1 (forkhead box protein O1) , transforming growth factor-ß, phosphorylated VEGFR2 (vascular endothelial growth factor receptor 2), and phosphorylated MAPK ERK1/ERK2 (mitogen-activated protein kinase) were higher in ischemic myocardial lysates from ND-controls compared with HFD-controls. Conversely, HFD-control tissue showed increased expression of phosphorylated endothelial nitric oxide synthase, phosphorylated FOXO1, VEGFR2, and MAPK ERK1/ERK2 with respect to ND-controls. Preliminary gene expression studies indicate differential modulation of transcriptional activity by EVs between the 2 dietary cohorts. Conclusions HFD produces a profound metabolic disorder that dysregulates the molecular mechanisms of collateral vessel formation in the ischemic myocardium, which may hinder the therapeutic angiogenic effects of EVs.

Intravenous injection of extracellular vesicles to treat chronic myocardial ischemia.

BACKGROUND: Mesenchymal stem cell-derived extracellular vesicles (EVs) appear to be a very exciting treatment option for heart disease. Here, we used a swine model of chronic myocardial ischemia to evaluate the efficacy of a less-invasive method of injection of EVs via a peripheral intravenous route. METHODS: Sixteen Yorkshire swine underwent placement of an ameroid constrictor on the left circumflex (LCx) artery at age 11 weeks to induce chronic myocardial ischemia. Two weeks later, they were divided into two groups: control (CON; n = 8), and intravenous injection of EVs (EVIV; n = 8). At 18 weeks of age, animals underwent final analysis and euthanasia. The chronically ischemic myocardium (LCx territory) was harvested for analysis. RESULTS: Intravenous injection (IV) of EVs induced several pro-angiogenic markers such as MAPK, JNK but not Akt. Whereas IV injections of EVs decreased VEGFR2 expression and inhibited apoptotic signaling (caspase 3), they increased expression of VEGFR1 that is believed to be anti-angiogenic. Injection of EVs did not result in an increase in vessel density and blood flow when compared to the control group. CONCLUSIONS: Although IV injection of EVs upregulated several pro-angiogenic signaling pathways, it failed to induce changes in vascular density in the chronically ischemic myocardium. Thus, a lack of increase in vascular density at the doses tested failed to elicit a functional response in ischemic myocardium.

Lower preoperative hematocrit, longer hospital stay, and neurocognitive decline after cardiac surgery.

BACKGROUND: Cardiopulmonary bypass may be associated with postoperative neurocognitive dysfunction; however, risk factors have not been clearly identified. We hypothesize that lower hematocrit levels are correlated with postoperative neurocognitive dysfunction. METHODS: A total of 30 patients underwent cardiac operations utilizing cardiopulmonary bypass and screening for neurocognitive dysfunction preoperatively and on postoperative day 4. Patients were analyzed according to hematocrit preoperatively, 6 hours postoperatively, and on postoperative day 4, and whether they received intra or postoperative transfusions of packed red blood cells. Neurocognitive data is presented as a difference in Repeatable Battery for the Assessment of Neuropsychological Status standardized score from baseline to postoperative day 4 and analyzed by unpaired two-tailed Spearman test and unpaired Mann-Whitney U test. RESULTS: There was a significant correlation between patients with lower hematocrit before surgery and a decline in neurocognitive function at postoperative day 4 (P < .05). All patients experienced a decrease in hematocrit during their hospital stay, but the hematocrit 6 hours postoperatively and postoperative day 4 did not impact cognition. Receiving a transfusion was also not associated with neurocognitive dysfunction. Patients with low hematocrit preoperatively had a consistently lower hematocrit throughout their stay. Prolonged total length of stay was also significantly associated with neurocognitive decline. CONCLUSION: A lower preoperative hematocrit and prolonged length of hospital stay are correlated with neurocognitive decline after cardiac surgery utilizing cardiopulmonary bypass.

Increased coronary arteriolar contraction to serotonin in juvenile pigs with metabolic syndrome.

Metabolic syndrome (MetS) is associated with alterations in coronary vascular smooth muscle and endothelial function. The current study examined the contractile response of the isolated coronary arterioles to serotonin in pigs with and without MetS and investigated the signaling pathways responsible for serotonin-induced vasomotor tone. The MetS pigs (8-weeks old) were fed with a hyper-caloric, fat/cholesterol diet and the control animals (lean) were fed with a regular diet for 12 weeks (n = 6/group). The coronary arterioles (90-180 µm in diameter) were dissected from the harvested pig myocardial tissues and the in vitro coronary arteriolar response to serotonin was measured in the presence of pharmacological inhibitors. The protein expressions of phospholipase A2 (PLA2), TXA2 synthase, and the thromboxane-prostanoid (TP) receptor in the pigs' left ventricular tissue samples were measured using Western blotting. Serotonin (10-9-10-5 M) induced dose-dependent contractions of coronary-resistant arterioles in both non-MetS control (lean) and MetS pigs. This effect was more pronounced in the MetS vessels compared with those of non-MetS controls (lean, P < 0.05]. Serotonin-induced contraction of the MetS vessels was significantly inhibited in the presence of the selective PLA2 inhibitor quinacrine (10-6 M), the COX inhibitor indomethacin (10-5 M), and the TP receptor antagonist SQ29548 (10-6 M), respectively (P < 0.05). MetS exhibited significant increases in tissue levels of TXA2 synthase and TP receptors (P < 0.05 vs. lean), respectively. MetS is associated with increased contractile response of porcine coronary arterioles to serotonin, which is in part via upregulation/activation of PLA2, COX, and subsequent TXA2, suggesting that alteration of vasomotor function may occur at an early stage of MetS and juvenile obesity.

Extracellular Vesicles Promote Arteriogenesis in Chronically Ischemic Myocardium in the Setting of Metabolic Syndrome.

Background Ischemic heart disease continues to be a leading cause of mortality in patients. Extracellular vesicles (EVs) provide a potential for treatment that may induce collateral vessel growth to increase myocardial perfusion. Methods and Results Nineteen male Yorkshire pigs were given a high-fat diet for 4 weeks, then underwent placement of an ameroid constrictor on the left circumflex artery to induce chronic myocardial ischemia. Two weeks later, the pigs received either intramyocardial vehicle (n=6), EVs (high-fat diet with myocardial EV injection [HVM]; n=8), or HVM and calpain inhibition (n=5). Five weeks later, myocardial function, perfusion, coronary vascular density, and cell signaling were examined. Perfusion in the collateral-dependent myocardium was increased during rapid ventricular pacing in the HVM group in both nonischemic (P=0.04) and ischemic areas of the ventricle (P=0.05). Cardiac output and stroke volume were significantly improved in the HVM group compared with the control group during ventricular pacing (P=0.006). Increased arteriolar density was seen in the HVM group in both nonischemic and ischemic myocardium (P=0.003 for both). However, no significant changes in the capillary density were observed between the control, HVM, and HVM and calpain inhibition groups (P=0.07). The group that received EVs with oral calpain inhibition had neither increased vessel density (P>0.99) nor improvement in blood flow or cardiac function (P=0.48) when compared with the control group. Conclusions These findings suggest that EVs promote angiogenesis in areas of chronic myocardial ischemia and improve cardiac function under conditions of diet-induced metabolic syndrome.

Impaired coronary contraction to phenylephrine after cardioplegic arrest in diabetic patients.

BACKGROUND: We have previously found that hyperkalemic cardioplegic arrest in the setting of cardiopulmonary bypass (CP/CPB) is associated with impairment of the coronary arteriolar response to phenylephrine in nondiabetic (ND) patients. We hypothesized that diabetes may alter coronary arteriolar response to alpha-1 adrenergic agonist in the setting of CP/CPB. In this study, we further investigated the effects of diabetes on the altered coronary arteriolar response to phenylephrine in patients undergoing cardiac surgery. METHODS: Coronary arterioles (90-150 µm in diameter) were harvested pre- and post-CP/CPB from the ND and diabetic mellitus (DM) patients (n = 8/group) undergoing cardiac surgery. In-vitro microvascular reactivity was examined in response to phenylephrine. The protein expression/localization of the alpha-1 adrenergic receptors in the atrial myocardium was measured by Western blotting and immunohistochemistry. RESULTS: Phenylephrine (10-9 to 10-4 M) induced a dose-dependent contractile response in both ND and DM vessels pre- and post-CP/CPB. There was no significant difference in the pre-CP/CPB contractile responses to phenylephrine between ND and DM groups. The post-CP/CPB contractile response was significantly diminished in both ND and DM groups compared with the respective pre-CP/CPB response (P < 0.05 versus pre-CP/CPB). This diminished contractile response was more pronounced in vessels from DM patients compared with vessels from ND patients (P < 0.05 versus ND). There were no significant differences in the protein expression of alpha-1A and alpha-1B receptors in the atrial myocardium between the ND and DM groups or tissue harvested pre- or post-CP/CPB. CONCLUSIONS: Diabetes is associated with a decreased contractile response of coronary arterioles to phenylephrine in the setting of CP/CPB versus that observed in ND patients. This alteration may contribute to the vasomotor dysfunction of coronary microcirculation seen early after CP/CPB in patients with diabetes.

Extracellular Vesicle Injection Improves Myocardial Function and Increases Angiogenesis in a Swine Model of Chronic Ischemia.

BACKGROUND: Mesenchymal stem cell-derived extracellular vesicles (EVs) are believed to be cardioprotective in myocardial infarct. The objective of this study was to examine the effects of human mesenchymal cell-derived EV injection on cardiac function, myocardial blood flow, and vessel density in the setting of chronic myocardial ischemia. METHODS AND RESULTS: Twenty-three Yorkshire swine underwent placement of an ameroid constrictor on their left circumflex artery. Two weeks later, the animals were split into 2 groups: the control group (CON; n=7) and the EV myocardial injection group (MVM; n=10). The MVM group underwent myocardial injection of 50 µg of EVs in 2 mL 0.9% saline into the ischemic myocardium. Five weeks later, the pigs underwent a harvest procedure, and the left ventricular myocardium was analyzed. Absolute blood flow and the ischemic/nonischemic myocardial perfusion ratio were increased in the ischemic myocardium in the MVM group compared with the CON group. Pigs in the MVM group had increased capillary and arteriolar density in the ischemic myocardial tissue compared with CON pigs. There was an increase in expression of the phospho-mitogen-activated protein kinase/mitogen-activated protein kinase ratio, the phospho-endothelial nitric oxide synthase/endothelial nitric oxide synthase ratio, and total protein kinase B in the MVM group compared with CON. There was an increase in cardiac output and stroke volume in the MVM group compared with CON. CONCLUSIONS: In the setting of chronic myocardial ischemia, myocardial injection of human mesenchymal cell-derived EVs increases blood flow to ischemic myocardial tissue by induction of capillary and arteriolar growth via activation of the protein kinase B/endothelial nitric oxide synthase and mitogen-activated protein kinase signaling pathways resulting in increased cardiac output and stroke volume.

Decreased contractile response of peripheral arterioles to serotonin after CPB in patients with diabetes.

BACKGROUND: Regulation of coronary vasomotor tone by serotonin is significantly changed after cardioplegic arrest and reperfusion. The current study investigates whether cardiopulmonary bypass may also affect peripheral arteriolar response to serotonin in patients with or without diabetes. METHODS: Human peripheral microvessels (90-180 µm diameter) were dissected from harvested skeletal muscle tissues from diabetic and non-diabetic patients before and after cardiopulmonary bypass and cardiac surgery (n = 8/group). In vitro contractile response to serotonin was assessed by videomicroscopy in the presence or absence of serotonin alone (10-9-10-5M) or combined with the selective serotonin 1B receptor (5-HT1B) antagonist, SB224289 (10-6M). 5-HT1A/1B protein expression in the skeletal muscle was measured by Western-blot and immunohistochemistry. RESULTS: There were no significant differences in contractile response of peripheral arterioles to serotonin (10-5M) pre-cardiopulmonary bypass between diabetic and non-diabetic patients. After cardiopulmonary bypass, contractile response to serotonin was significantly impaired in both diabetic and non-diabetic patients compared to their pre-cardiopulmonary bypass counterparts (P < .05). This effect was more pronounced in diabetic patients than non-diabetic patients (P < .05 versus non-diabetic). The contractile response to serotonin was significantly inhibited by the 5-HT1B antagonist in both diabetic and non-diabetic vessels (P < .05 versus serotonin alone). There were no significant differences in the expression/distribution of 5-HT1A/1B between non-diabetic and diabetic groups or between pre- versus post- cardiopulmonary bypass vessels. CONCLUSIONS: Cardiopulmonary bypass is associated with decreased contractile response of peripheral arterioles to serotonin and this effect was exaggerated in the presence of diabetes. Serotonin-induced contractile response of the peripheral arterioles was via 5-HT1B in both diabetic and non-diabetic patients.

Glycogen synthase kinase 3ß inhibition reduces mitochondrial oxidative stress in chronic myocardial ischemia.

OBJECTIVES: Glycogen synthase kinase 3ß (GSK-3ß) inhibition has been reported to increase microvascular density and improve myocardial blood flow in a porcine model of chronic myocardial ischemia and metabolic syndrome. Inhibition of GSK-3ß can also be cardioprotective by modulating fibrosis signaling and mitochondrial-induced apoptosis. We hypothesized GSK-3ß inhibition would have a beneficial effect on myocardial fibrosis and oxidative stress in a porcine model of chronic myocardial ischemia and metabolic syndrome. METHODS: Pigs were fed a high fat diet for 4 weeks followed by placement of an ameroid constrictor to the left circumflex coronary artery. Three weeks later animals received either no drug or a GSK-3ß inhibitor. The diets and placebo/GSK-3ß inhibition were continued for an additional 5 weeks, the pigs were then euthanized, and the myocardial tissue was harvested. Collagen expression was analyzed via Picrosirius staining. Oxidative stress was analyzed via Oxyblot analysis. Protein expression was analyzed via Western blot. RESULTS: GSK-3ß inhibition was associated with decreased collagen expression and oxidative stress in the ischemic and nonischemic myocardial tissue compared with control. There was a decrease in profibrotic proteins transforming growth factor-ß, p-SMAD2/3, and matrix metalloproteinase-9, and in proapoptotic and oxidative stress proteins, apoptosis inducing factor, the cleaved caspase 3/caspase 3 protein ratio and phosphorylated myeloid cell leukemia sequence-1 in the GSK-3ß inhibited group compared with the control. CONCLUSIONS: In the setting of metabolic syndrome and chronic myocardial ischemia, inhibition of GSK-3ß decreases collagen formation and oxidative stress in myocardial tissue. GSK-3ß inhibition might be having this beneficial effect by downregulating transforming growth factor-ß/SMAD2/3 signaling and decreasing mitochondrial induced cellular stress.

Diabetes and Cardioplegia.

Cardiac surgery with cardiopulmonary bypass and cardioplegic arrest is associated with injury to the vasculature and microcirculation leading to coronary microvascular dysfunction, permeability changes and cardiac dysfunction. In the setting of cardiopulmonary bypass with cardioplegia, poorly-controlled diabetes is associated with significant changes in endothelium-dependent and independent vascular dysfunction, vascular reactivity, vascular permeability, protein expression, cell death, coronary/peripheral microcirculation and reduced vasomotor tone leading to hypotension and impaired endothelial function. The gene expression profiles after cardiopulmonary bypass with cardioplegic arrest is quantitatively and qualitatively different in patients with diabetes. Gene expression profiling capitalizing on the differences between patients with and without diabetes is a good place to identify potential medical targets.

Alcohol attenuates myocardial ischemic injury.

BACKGROUND: Moderate alcohol consumption is cardioprotective but the mechanism of action remains unclear. Nuclear factor κ-B regulates the expression of genes involved in inflammation, stress, and apoptosis. We used a swine model of diet-induced metabolic syndrome to investigate the effects of red wine and vodka on nuclear factor κ-B signaling and cytokine activity in chronically ischemic myocardium. METHODS: Yorkshire swine were given a high-fat diet for 4 weeks; an ameroid constrictor was then placed on the left circumflex artery. The high-fat diet was continued and the swine were divided into 3 groups for 7 weeks: hypercholesterolemic diet alone (control, n = 8), hypercholesterolemic diet with vodka (vodka, n = 8), and hypercholesterolemic diet with wine (wine, n = 8). Ischemic myocardium was analyzed by Western blot and cytokine array. RESULTS: Administration of alcohol was associated with decreased expression of inhibitor of κ-B kinase complex α, inhibitor of κ-B kinase complex ß, and phosphorylated inhibitor of κ-B ß in the ischemic myocardium compared with the control group. Alcohol administration demonstrated an increase in nuclear factor κ-B in the ischemic myocardium. Both wine and vodka demonstrated a significant decrease in leptin, interleukin-1α, IL-13, IL-15, and interferon-γ. Vodka demonstrated a significant decrease in phosphorylated BCL-2 and caspase-9. CONCLUSION: In ischemic myocardium, alcohol modulates the nuclear factor κ-B pathway, which may contribute to the adaptive response of tissues to the stress of ischemia. Furthermore, both wine and vodka decreased multiple proinflammatory cytokines. This study provides a mechanism by which alcohol may be cardioprotective in ischemic myocardium.

Lessons Learned From an Untreated "Benign" Thoracic Tumor.

We describe a patient with Doege-Potter syndrome (solitary fibrous tumor of the pleura presenting with hypoglycemia) and illustrate several important lessons learned from the case. Seven years after the initial diagnosis, the tumor showed significant growth and developed a high-grade undifferentiated component. Solitary fibrous tumors do grow and cannot be deemed benign. Resection should be considered in all patients who are candidates for operation upon diagnosis. Our case also serves as a reminder of this rare syndrome, inasmuch as early recognition of the association of hypoglycemia with these tumors may have allowed for earlier diagnosis and avoidance of extensive tests in our patient.

Continuous Glucose Monitoring in the Cardiac ICU: Current Use and Future Directions.

Perioperative glucose control is highly important, particularly for patients undergoing cardiac surgery. Variable glucose levels before, during and after cardiac surgery lead to increased post-operative complications and patient mortality. [1] Current methods for intensive monitoring and treating hyperglycemia in the Intensive Care Unit (ICU) usually involve hourly glucose monitoring and continuous intravenous insulin infusions. With the advent of more accurate subcutaneous glucose monitoring systems, the role of improved glucose control with newer systems deserves consideration for widespread adoption.

Distinguishing persistent insulin autoantibodies with differential risk: nonradioactive bivalent proinsulin/insulin autoantibody assay.

A subset of children develops persistent insulin autoantibodies (IAA; almost always as the only islet autoantibody) without evidence of progression to diabetes. The aim of the current study was the development and characterization of the performance of a nonradioactive fluid phase IAA assay in relation to standard IAA radioassay. We developed a nonradioactive IAA assay where bivalent IAA cross-link two insulin moieties in a fluid phase. The serum samples positive for anti-islet autoantibodies from 150 newly diagnosed patients with diabetes (Barbara Davis Center plus Diabetes Autoantibody Standardization Program [DASP] workshop) and 70 prediabetic subjects who were followed to diabetes were studied. In addition, sequential samples from 64 nondiabetic subjects who were persistently IAA(+) were analyzed. With 99th percentile of specificity, the new assay with the technology from Meso Scale Discovery Company (MSD-IAA) detects as positive 61% (61 of 100) of new-onset patients and 80% (56 of 70) of prediabetic patients compared with our current fluid phase micro-IAA radioassay (mIAA; 44 and 74%, respectively). In addition, MSD-IAA demonstrated better sensitivity than our mIAA from blinded DASP workshop (68 vs. 56% with the same 99% specificity). Of 64 IAA(+) nondiabetic subjects, 25% (8 of 32) who had only IAA and thus the low risk for progression to diabetes were positive with MSD-IAA assay. In contrast, 100% (32 of 32) high-risk children (IAA plus other islet autoantibodies) were positive with MSD-IAA. The IAA detectable by radioassay, but not MSD-IAA, were usually of lower affinity compared with the IAA of the high-risk children. These data suggest that a subset of IAA with current radioassay (not MSD-IAA) represents biologic false positives in terms of autoimmunity leading to diabetes. We hypothesize that factors related to the mechanism of loss of tolerance leading to diabetes determine high affinity and MSD-IAA reactivity.

Use of CoZmonitor in youth with type 1 diabetes.

BACKGROUND: The purpose of this study was to evaluate the effectiveness of directly integrating self-monitoring blood glucose (BG) information with insulin pump therapy on overall glycemic control. METHODS: In this randomized trial, 34 youth with type 1 diabetes using insulin pump therapy were trained on the use of the Deltec Cozmo Insulin Pump. Seventeen were randomized to use the CoZmonitor Blood Glucose Module, a device that attaches to the back of the pump using FreeStyle technology to perform BG tests which read directly on the pump screen. The remaining 17 (control group) used a FreeStyle Flash meter, a stand-alone BG meter, for their BG testing. At baseline, 3 and 6 months, the subjects filled out a questionnaire, had a hemoglobin A1c (HbA1c) test, and had pumps and meters downloaded. RESULTS: After 3 months of study, there were no changes in mean HbA1c (+/- SD) values for the experimental (8.7 +/- 1.1 to 8.6 +/- 1.1) or the control groups (9.1 +/- 1.4 to 9.2 +/- 1.5). There were also no significant differences in HbA1c values after 6 months. The average number of BG tests per day did not change significantly in either group during the study. After 3 and 6 months, the experimental group rated satisfaction with the use of the CoZmonitor at 4.4 and 3.8 (respectively) on a five-point Likert scale, with 5 being the most satisfied. CONCLUSIONS: Although significant changes in HbA1c values or the number of BG tests were not found, use of the BG module had a positive level of satisfaction.

Improved glycemic control after long-term insulin pump use in pediatric patients with type 1 diabetes.

BACKGROUND: There are currently few data available on the long-term use of continuous subcutaneous insulin infusion (CSII) (insulin pump) therapy in children. METHODS: Charts from 291 youth with type 1 diabetes (T1D) who were treated with CSII therapy for at least 1 year were reviewed. Data analysis included hemoglobin A(1c)(HbA(1c)) values, body mass index (BMI) values, and the occurrence of severe hypoglycemia (SH) or diabetic ketoacidosis (DKA) events. RESULTS: For the 291 patients, the mean age (+/-SD) for beginning CSII therapy was 13.3 +/- 3.7 years. The mean duration of CSII was 3.7 +/- 1.9 years (range 1-9 years). The baseline HbA(1c) value was 8.7 +/- 1.0%, compared to 8.2 +/- 0.9% after 1 year (P < 0.0001). The most recent value for all patients was 8.3 +/- 1.3% (P < 0.0001 compared to the baseline values for the same subjects). There was no advantage in glycemic control in the teen years as a result of initiating CSII in the pre-teen years compared to the teen years. SH events decreased from 9.06 events per 100 patient-years before CSII therapy to 7.96 events per 100 patient-years while on CSII therapy. The incidence of DKA increased from 1.39 events pre-CSII to 3.98 events per 100 patient-years while on CSII therapy. BMI z-scores showed a nonsignificant increase. CONCLUSIONS: The long-term use of CSII in pediatric patients is beneficial in lowering mean HbA(1c) levels and the number of SH events. However, there was an increase in the number of DKA episodes.