In Situ Oxidative Stress and Atrial Cell Deaths in Patients with Valve Disease.

BACKGROUND: Left ventricular hypertrophy and myocardial remodeling occur with aortic valve disease and may lead to heart failure. Although increased oxidative stress and inflammatory factors have been implicated in heart failure, their role in the progression of valve disease remains unclear. OBJECTIVES: We investigated the role of oxidative stress and inflammatory factors in valve disease whether this relates to cell death. METHODS: Blood samples were taken from 24 patients with valve disease before surgery and the results were compared with those from blood samples from 30 control healthy subjects. Myocardial biopsies from patients with valve disease were also collected before cannulation of the right atrial appendage. NF-κB activities in atrial and mononuclear cells nuclear extracts were determined by electrophoretic mobility shift assay. RESULTS: Nuclear factor kappaB activities were significantly greater in mononuclear cells from AVD patients compared with healthy controls and the antigens were detectable in atrial tissues valve disease patients. Plasma C-reactive protein, B-natriuretic peptides, plasma tumor necrosis factor alpha and soluble tumor necrosis factor receptor 1 and 3-nitrotyrosine levels were significantly higher in valve disease patients. Inducible nitric oxide and 3-nitrotyrosine antigens and cells expressing CD45 antigens were detected within atrial tissues obtained from valve disease patients suggesting oxidative stress originated from in situ leukocytes. CONCLUSION: The findings suggest that oxidative stress originating from in situ leukocytes within the atrial myocardium may be the potential trigger for excessive transcriptional activities and apoptotic cell death within the atrial myocardium of valve disease patients. This represents a potential therapeutic target.

Effects of maternal high-fat diet and statin treatment on bone marrow endothelial progenitor cells and cardiovascular risk factors in female mice offspring fed a similar diet.

OBJECTIVES: The aim of this study was to prove that one possible statin-related protective mechanism in dams and offspring fed a high-fat diet (HFD) is the reduction in cardiovascular risk and impairment of the vasculogenic element of endothelial regeneration. METHODS: To explore this, virgin C57 BL/6 mice (n = 8/group) were fed an HFD (fat: 45% kcal) or standard chow (C; fat: 21% kcal) from weaning and throughout their pregnancy and lactation. Half of the HFD group also was given the 3-hydroxy-3-methylglutaryl-coenzyme A reductase inhibitor pravastatin (S) through their drinking water (5 mg/kg body weight per day) to create HF+S dam group (n = 8/group). Offspring from each group were fed HFD or C diet from weaning to adulthood, generating respective dam/offspring dietary groups (C/C, HF/HF, HF+S/HF; n = 8/group). Body weight, blood pressure, and serum lipid profile were measured in female offspring at age 24 wk, and bone marrow endothelial progenitor cells (EPCs) were cultured. RESULTS: The results indicated that in the female offspring, the statin-fed (HF+S/HF) cohort had lower total and low-density lipoprotein cholesterol concentrations, were less obese and hypertensive, and had reduced C-reactive proteins (CRPs) compared with the HF/HF phenotype. The results also showed an increased bone marrow EPCs expressing colony numbers (P < 0.001) compared with the HF/HF phenotype. CONCLUSIONS: Results from the present study demonstrated that statin administration in early life to dams fed on a HFD had a significant effect on their female offspring in terms of reduction in cardiovascular risk factors. Additionally, statin administration to female offspring on an HFD during early life was associated with reduction in circulating CRPs and an increased bone marrow EPC numbers and colony-forming characteristics.

Consequence of patient substitution of nattokinase for warfarin after aortic valve replacement with a mechanical prosthesis.

This report describes a patient's self-substitution of nattokinase for the vitamin K antagonist warfarin after aortic valve replacement with a mechanical prosthesis. Nattokinase is an enzyme derived from a popular fermented soybean preparation in Japan (natto), which has fibrinolytic properties and is gaining popularity in nontraditional health journals and nonmedical health websites as an over-the-counter thrombolytic. After nearly a year of use of nattokinase without warfarin, the patient developed thrombus on the mechanical valve and underwent successful repeat valve replacement. We believe this is the first documented case of nattokinase being used as a substitute for warfarin after valve replacement, and we strongly discourage its use for this purpose.

One problem two issues! Left ventricular systolic and diastolic dysfunction in aortic stenosis.

Reports suggested that immediate post-aortic valve replacement (AVR); left ventricular (LV) dysfunction may be an important risk for morbidity and mortality in patients requiring positive inotropic support. Several factors have been identified as significant prognostic factors i.e., LV systolic dysfunction, LV diastolic dysfunction (LV-DD), heart failure and myocardial infarction (MI). Specific to pathophysiological changes associated with AS, markers of systolic LV function (e.g., LVEF) have been extensively studied in management, yet only a few studies have analysed the association between LV-DD and immediate post-operative LV dysfunction This review brings together the current body of evidence on this issue.

Gender differences in the expression of genes involved during cardiac development in offspring from dams on high fat diet.

Previously we have demonstrated that maternal high fat diet (HF) during pregnancy increase cardiovascular risk in the offspring, and pharmacological intervention using statins in late pregnancy reduced these risk factors. However the effects of maternal HF-feeding and statin treatment during pregnancy on development of heart remain unknown. Hence we measured expression of genes involved in cell cycle progression (cyclin G1), ventricular remodelling brain natriuretic peptide (BNP), and environmental stress response small proline-rich protein 1A (SPRR 1A) in the offspring left ventricle (LV) from dams on HF with or without statin treatment. Female C57 mice were fed a HF diet (45% kcal fat) 4 weeks prior to conception, during pregnancy and lactation. From the second half of the pregnancy and throughout lactation, half of the pregnant females on HF diet were given a water-soluble statin (Pravastatin) in their drinking water (HF + S). At weaning offspring were fed HF diet to adulthood (generating dam/offspring dietary groups HF/HF and HF + S/HF). These groups were compared with offspring from dams fed standard chow (C 21% kcal fat) and fed C diet from weaning (C/C). LV mRNA levels for cyclin G1, BNP and SPRR 1A were measured by RT-PCR. Heart weights and BP in HF/HF offspring were higher versus C/C group. Maternal Pravastatin treatment reduced BP and heart weights in HF + S/HF female offspring to levels found in C/C group. LV cyclin G1 mRNA levels were lower in HF/HF versus both C/C and HF + S/HF offspring. BNP mRNA levels were elevated in HF/HF females but lower in males versus C/C. BNP gene expression in HF + S/HF offspring was similar to HF/HF. SPRR 1A mRNA levels were similar in all treatment groups. Statins given to HF-fed pregnant dams reduced cardiovascular risk in adult offspring, and this is accompanied by changes in expression of genes involved in adaptive remodelling in the offspring LV and that there is a gender difference.

Iatrogenic retained foreign body in the right atrium. Lessons to Learn.

INTRODUCTION: We report a case of a retained foreign body in the right atrium and the review of the literature discussing several cases where the poor attention and management of medical staff has led to worsening consequences to patient's health. PRESENTATION OF CASE: In our case the mass demonstrated on MRI scan turned out to be an inflammatory process and organized clotted blood built around a broken piece of a plastic cannula protruding out of the right atrium. This caused debilitating pleuritic pain to the patient on presentation. DISCUSSION: The cause of this iatrogenic retained piece of cannula may well be from the patients prior diagnostic investigations. CONCLUSION: Algorithm managed indications for surgical removal of such foreign bodies in symptomatic patients lead to better patient's outcomes and decreases the chances of infection, embolization, or erosions within the heart. Keeping this in view, we managed our patient with success.

Nitric Oxide-Dependent Regulation of Cytokines Release in Type-II Diabetes Mellitus.

The mechanism of release of proinflammatory cytokines by blood granulocytes in diabetes is unknown. We investigated whether diabetes mellitus affects the production of cytokines by granulocytes (PMN) and mononuclear cells (PBMCs) and whether this is modulated by NO. Isolated PMN and PBMC from with or without type-II diabetes mellitus were incubated at 37°C for 6 h with S-nitroso-N-acetylpenicillamine (SNAP) at 0, 1, and 100 µ M with or without lipopolysaccharides (LPS) stimulation (1 µ g/mL). Supernatants were assayed for tumor necrosis factor- α (TNF- α ) and interleukin-8 (IL-8) by sandwich ELISA. Significant increases in TNF- α and IL-8 were observed only in PMN from diabetic subjects with or without LPS stimulation and that exogenous NO inhibited further production of cytokines in a concentration-dependent manner. However, activity of PBMC when stimulated with LPS was greatly enhanced by diabetes, but not affected by NO production. Hence, suggesting that granulocytes activation and participation in diabetes related complications is modulated by NO bioavailability.

Extracorporeal membrane oxygenation support in a situation of diagnostic dilemma.

Severe acute respiratory distress syndrome (ARDS) in children carries a high morbidity and mortality. High frequency ventilation and extracorporeal membrane oxygenation (ECMO) are used as rescue modes of support in difficult situations. Malignancy may be considered to be a relative contraindication to ECMO support. We report a case where the decision was made to support the patient with ECMO for fulminant Epstein-Barr (EBV) infection while investigations were being done to exclude an underlying malignancy.

Serum gamma glutamyl transferase: a novel biomarker for screening of premature coronary artery disease.

BACKGROUND: We aimed to elucidate the association between gamma glutamyl transferase (GGT) activity with prevalence of premature coronary artery disease (CAD) in young Pakistani patients undergoing diagnostic coronary angiography. METHODS: A total of 218 young adults (age ≤ 45 years) underwent diagnostic angiography. Serum samples were taken from all the patients and analyzed for serum GGT activity, cholesterol and triglycerides. RESULTS: Coronary artery disease patients had significantly increased GGT activity (P = .001) and exhibited a significant positive correlation with blood pressure, cholesterol, blood glucose, and smoking and negative correlation with total antioxidant status (P < .01). CONCLUSION: The study revealed good diagnostic accuracy at cutoff of 35 U/L with a sensitivity of 92%, specificity of 81%, and diagnostic odds ratio of 48 in estimation of premature CAD in young Pakistanis.

Surgical treatment of ruptured metastatic pleomorphic leiomyosarcoma.

A rare case of primary cardiac leiomyosarcoma was diagnosed in a 21-year-old man who presented with a groin mass thought to be a sebaceous cyst. Histopathology revealed a high-grade pleomorphic leiomyosarcoma. Combined positron-emission and computed tomography showed a large metabolically active left atrial mass with multiple metastases. Major debulking resection was undertaken, followed by radiation and chemotherapy. At 13 months postoperatively, limited spread has been detected, and the patient had no limitation in daily life.

Tumor necrosis factor alpha -308 gene locus promoter polymorphism: an analysis of association with health and disease.

Tumor necrosis factor-alpha (TNF-alpha) is a potent immunomediator and proinflammatory cytokine that has been implicated in the pathogenesis of a large number of human diseases. The location of its gene within major histocompatibility complex and biological activities has raised the possibility that polymorphisms within this locus may contribute to the pathogenesis of wide range of autoimmune and infectious diseases. For example, a bi-allelic single nucleotide substitution of G (TNFA1 allele) with A (TNFA2 allele) polymorphism at -308 nucleotides upstream from the transcription initiation site in the TNF-alpha promoter is associated with elevated TNF-alpha levels and disease susceptibilities. However, it is still unclear whether TNF-alpha -308 polymorphism plays a part in the disease process, in particular whether it could affect transcription factor binding and in turn influence TNF-alpha transcription and synthesis. Several studies have suggested that TNFA2 allele is significantly linked with the high TNF-alpha-producing autoimmune MHC haplotype HLA-A1, B8, DR3, with elevated serum TNF-alpha levels and a more severe outcome in diseases. This review discusses the genetics of the TNF-alpha -308 polymorphism in selected major diseases and evaluates its common role in health and disease.

Inspired nitric oxide and modulation of oxidative stress during cardiac surgery.

Evidence in the literature is contradictory regarding the precise role of nitric oxide (NO) in modulating systemic inflammatory response induced by cardiopulmonary bypass (CPB). We studied the impact of inspired NO gas on physiological function and markers of inflammation-oxidative stress for subjects (n=15, age 62+/-4.5 and 12/3 M/F) scheduled for coronary artery bypass graft (CABG) operation. Outcomes from subjects that received 5 ppm and 20 ppm of inspired NO (n=5/group) were compared to those not given NO gas. Breath-to-breath measurement commenced at the start of intubation and continued up to 4h later. Indices of cardiovascular function, alveolar-capillary gas exchange and haematological parameters were not significantly different in outcomes for the inspired NO groups as compared with control. We observed a reduction in mean systemic arterial in all subjects at 30 min and 4h after bypass when compared with pre bypass values. Markers of systemic inflammatory response and oxidative stress increased during CPB particularly at 4h and 24h after the initiation of bypass. In contrast, we observed a reduction in expired NO, at 24h after surgery in the groups given inspired NO. In addition, there was also a significant reduction in oxidative stress markers in blood at 24h after surgery for the groups given inspired NO as compared with the control group. In contrast, cytokines response remained similar in all the three groups at all time points. The results suggested that inspired NO gas has an antioxidant property that reduces the levels of cell death, and is not associated with significantly worse-off physiological outcomes.

Long-term maternal high-fat feeding from weaning through pregnancy and lactation predisposes offspring to hypertension, raised plasma lipids and fatty liver in mice.

In rodents, adverse prenatal nutrition, such as a maternal diet rich in fat during pregnancy, enhances susceptibility of the offspring to hypertension, type 2 diabetes and other features of the human metabolic syndrome in adulthood. However, previous experimental studies were confined to short-term modifications of the maternal diet during pregnancy and/or lactation periods, a situation uncommon in humans. Moreover in humans, the offspring may also consume a high-fat diet, which may take them beyond the range to which their development has adapted them to respond healthily. We examined in C57 mice the effects on offspring of feeding their mothers a high-fat (HF) or standard chow (C) diet from weaning through pregnancy and lactation, and whether there are additive phenotypic effects of feeding the offspring an HF diet from weaning to adulthood (dam-offspring dietary group HF-HF). This group was compared with offspring from HF-fed dams fed a C diet from weaning to adulthood (HF-C) and offspring from C-fed mothers fed the C or HF diet (C-C and HF-C, respectively). HF-HF, HF-C and C-HF adult female offspring were heavier, fatter, and had raised serum cholesterol and blood pressure compared with C-C female offspring. We observed a similar trend in male offspring except for the HF-C group which was not heavier or fatter than male C-C offspring. Histology showed lipid vacuoles within hepatocytes in the HF-HF, HF-C and C-HF but not the CC offspring. Serum C-reactive protein was elevated in female (C-HF and HF-HF) but not in male offspring. Elevated blood pressure in the HF-C and C-HF groups was attenuated in the HF-HF group in males but not in females. These findings indicate that long-term consumption of an HF diet by the mother predisposes her offspring to developing a metabolic syndrome-like phenotype in adult life, although cardiovascular effects of an HF diet are related to sex specificity in the HF-HF group.

Oxidative stress as a mediator of cardiovascular disease.

During physiological processes molecules undergo chemical changes involving reducing and oxidizing reactions. A molecule with an unpaired electron can combine with a molecule capable of donating an electron. The donation of an electron is termed as oxidation whereas the gaining of an electron is called reduction. Reduction and oxidation can render the reduced molecule unstable and make it free to react with other molecules to cause damage to cellular and sub-cellular components such as membranes, proteins and DNA. In this paper, we have discussed the formation of reactive oxidant species originating from a variety of sources such as nitric oxide (NO) synthase (NOS), xanthine oxidases (XO), the cyclooxygenases, nicotinamide adenine dinucleotide phosphate (NAD(P)H) oxidase isoforms and metal-catalysed reactions. In addition, we present a treatise on the physiological defences such as specialized enzymes and antioxidants that maintain reduction-oxidation (redox) balance. We have also given an account of how enzymes and antioxidants can be exhausted by the excessive production of reactive oxidant species (ROS) resulting in oxidative stress/nitrosative stress, a process that is an important mediator of cell damage. Important aspects of redox imbalance that triggers the activity of a number of signalling pathways including transcription factors activity, a process that is ubiquitous in cardiovascular disease related to ischemia/reperfusion injury have also been presented.

Tracing the origins of postoperative atrial fibrillation: the concept of oxidative stress-mediated myocardial injury phenomenon.

BACKGROUND: Atrial fibrillation (AF) is the most common arrhythmia associated with coronary artery surgery and is an important factor contributing to postoperative morbidity and mortality. Recently, there is growing evidence that dysregulation of the oxidant-antioxidant balance, inflammatory factors and discordant alteration of energy metabolites may play a significant role in its pathogenesis. DESIGN: We evaluated the link between postoperative atrial fibrillation with inflammatory factors and oxidative stress. METHODS: We searched all databases in Medline, Pubmed, ISI, the Cochrane database, and Embase. We identified more than 100 trials, multiple metaanalyses, and three sets of practice guidelines for the prevention of PAF in cardiac surgery. RESULTS: Mechanisms of postoperative AF are likely to be multifactorial and are influenced by preoperative, intraoperative and postoperative factors including a genetic basis. Electrical remodelling is thought to be related to the generation of reactive oxidant species and inflammatory factors during the ischemia-reperfusion phase of cardiac surgery. Nicotinamide adenine dinucleotide phosphate (NADPH) oxidase was found to be the primary source of superoxide within the human atrial myocardium (in patients in sinus rhythm and in those with AF) and linked with paroxysmal and chronic AF. Reactive oxidant species cause lipid peroxidation, breakdown of cell membrane, decreased mitochondrial function, calcium overload and apoptosis. This affect was shown to be reversed by exogenous nitric oxide/donors (sodium nitroprusside). Inflammatory factors such as the rise in white blood cell count, C-reactive proteins were implicated in the pathogenesis of AF. In contrast, new evidence identifies statins as having both antioxidant and anti-inflammatory properties and that their use reduces the incidence of postoperative AF (57% in the control vs. 35% in the atorvastatin group). Other antiinflammatory strategies include steroids with one study showing postoperative AF occurred in 21% in the steroid group compared with 51% in the placebo group although their use resulted in an increase in other complications. The mainstay of therapy however, remains to be beta-blockers alone which impart a modest influence on overall rates of AF with a reduction from 33.7 to 16.9% (OR: 0.37, 95% CI: 0.29-0.48). Angiotensin converting enzyme inhibitors (ACEIs) and angiotensin receptor blockers has been shown in one study to reduce the risk of developing new-onset AF by nearly 50%, although this has not been adequately evaluated in cardiac surgery. CONCLUSION: Inflammatory factors and oxidative stress play a major role in the pathogenesis of postoperative AF. This review provides an analysis of current evidence in support of efforts directed at antiinflammatory and antioxidant agents as interventions.

Should the cardiotomy suction blood be cell-saver processed before retransfusion? A clinico-pathologic mystery.

The use of cardiotomy suction (CS) in cardiopulmonary bypass (CPB) surgery is associated with a pronounced systemic inflammatory response and a resulting coagulopathy as well as exacerbating the microembolic load. However, CS is yet been employed to preserve autologous blood during on-pump surgery. Though processing CS blood with a cell saving device is considered paramount in significantly reducing the inflammatory effects, yet this might also have potential harmful effects on the outcome of the patient. Here we discuss the results of the different prospective and randomized studies to address these issue if the cell saver technique in processing CS blood before retransfusion is to establish its identity and role in the CPB surgery.

Functional adaptation to oxidative stress by memory T cells: an analysis of the role in the cardiovascular disease process.

T cells participate in combating infection and critically determine the outcomes in any given disease process. Impaired immune response occurs in a number disease processes such as in cancer and atherosclerosis although the underlying mechanisms are still not fully understood. This article gives an up-to-date review of T cells development and functional adaptation to pathophysiological stimuli and participation in the cardiovascular disease process. In addition, we have discussed the signaling pathways controlled by the microenvironment that determine T cells function and resultant type of immune response. We have also discussed in detail how oxidative stress is a key component of the micro environmental interaction.