Methods of cell purification: a critical juncture for laboratory research and translational science

Research in cell biology and the development of translational technologies are driven by competition, public expectations, and regulatory oversight, putting these fields at a critical juncture. Success in these fields is quickly becoming dependent on the ability of researchers to identify and isolate specific cell populations from heterogeneous mixtures accurately and efficiently. Many methods for cell purification have been developed, and each has advantages and disadvantages that must be considered in light of the intended application. Current cell separation strategies make use of surface proteins, genetic expression, and physics to isolate specific cells by phenotypic traits. Cell purification is also dependent on the cellular reagents available for use and the intended application, as these factors may preclude certain mechanisms used in the processes of labeling and sorting cells.

Antioxidant and anti-inflammatory effects of exercise in diabetic patients

Diabetes is a chronic metabolic disease which is characterized by absolute or relative deficiencies in insulin secretion and/or insulin action. The key roles of oxidative stress and inflammation in the progression of vascular complications of this disease are well recognized. Accumulating epidemiologic evidence confirms that physical inactivity is an independent risk factor for insulin resistance and type II diabetes. This paper briefly reviews the pathophysiological pathways associated with oxidative stress and inflammation in diabetes mellitus and then discusses the impact of exercise on these systems. In this regard, we discuss exercise induced activation of cellular antioxidant systems through “nuclear factor erythroid 2-related factor.” We also discuss anti-inflammatory myokines, which are produced and released by contracting muscle fibers. Antiapoptotic, anti-inflammatory and chaperon effects of exercise-induced heat shock proteins are also reviewed.

Serum adiponectin level is not only decreased in metabolic syndrome but also in borderline metabolic abnormalities

Objective:

Along with the increasing prevalence of obesity and related diseases, particularly atherosclerotic diseases, metabolic syndrome (MetS) is now a common and major public health issue in many countries around the world. Adiponectin, a protein secreted by the adipose tissue, has become recognized as a key player in the development of MetS. These days, not only MetS but also borderline metabolic/physiological abnormalities, such as impaired fasting glucose, high normal blood pressure and high normal plasma cholesterol, have been reported to be risk factors for atherosclerotic disease. Therefore, we undertook this study to determine the relationship between adiponectin and borderline metabolic/physiological abnormalities, as well as MetS.

Design:

A cross-sectional study performed from April 2007 to November 2009.

Subjects:

In 16 892 Japanese adults (10 008 men and 6884 women), we examined the relationship between the serum adiponectin concentration and borderline metabolic/physiological abnormalities or MetS by a questionnaire survey about medical treatment, body size measurement and measurement of laboratory parameters including the serum adiponectin concentration.

Results:

Adiponectin showed a significant negative correlation with the number of MetS components. In subjects without overt diabetes mellitus, hypertension or dyslipidemia, the adiponectin concentration also showed a significant negative correlation with the number of borderline metabolic abnormalities.

Conclusion:

The decrease of circulating adiponectin may start before the development of diabetes mellitus, hypertension, dyslipidemia or MetS. Adiponectin is an important biomarker for reflecting the adverse influence of visceral fat in persons with MetS, and also in these subclinical states.

Exercise Training Prevents Coronary Endothelial Dysfunction in Type 2 Diabetic Mice

Type 2 diabetes (T2D) is a leading risk factor for cardiovascular diseases including atherosclerosis and coronary heart disease. Exercise training (ET) is thought to have a beneficial effect on these disorders, but the basis for this effect is not fully understood. Because endothelial dysfunction plays a key role in the pathological events leading to cardiovascular complications in T2D, we hypothesized that the effects of ET will be evidenced by improvements in coronary endothelial function. To test this hypothesis, we assessed the effects of ET on vascular function of diabetic (db/db, Lepr(db)) mice by evaluating endothelial function of isolated coronary arterioles of wild-type (WT) and db/db mice with/without ET. Although dilation of vessels to the endothelial-independent vasodilator, sodium nitroprusside was not different between db/db and WT, dilation to the endothelial-dependent agonist, acetylcholine (ACh), was impaired in db/db compared to WT mice. Vasodilation to ACh was restored in db/db with ET and insulin sensitivity was improved in the db/db after ET. Exercise did not change body weight of db/db, but superoxide dismutase (SOD1 and SOD2) and phosphorylated- eNOS protein (Ser1177) expression in heart tissue was up-regulated whereas tumor necrosis factor-alpha (TNF-α) protein level was decreased by ET. Serum level of interleukin-6 (IL-6) was higher in db/db mice but ET decreased IL-6. This suggests that ET may improve endothelial function by increasing nitric oxide bioavailability as well as decreasing chronic inflammation. We suggest this connection may be the basis for the benefit of ET in T2D.

Personalized vascular medicine: individualizing drug therapy

Personalized medicine refers to the application of an individual's biological fingerprint - the comprehensive dataset of unique biological information - to optimize medical care. While the principle itself is straightforward, its implementation remains challenging. Advances in pharmacogenomics as well as functional assays of vascular biology now permit improved characterization of an individual's response to medical therapy for vascular disease. This review describes novel strategies designed to permit tailoring of four major pharmacotherapeutic drug classes within vascular medicine: antiplatelet therapy, antihypertensive therapy, lipid-lowering therapy, and antithrombotic therapy. Translation to routine clinical practice awaits the results of ongoing randomized clinical trials comparing personalized approaches with standard of care management.

Cardiac regeneration therapy: connections to cardiac physiology

Without heart transplantation, a large number of patients with failing hearts worldwide face poor outcomes. By means of cardiomyocyte regeneration, cardiac regeneration therapy is emerging with great promise as a means for restoring loss of cardiac function. However, the limited success of clinical trials using bone marrow-derived cells and myoblasts with heterogeneous constituents, transplanted at a wide range of cell doses, has led to disagreement on the efficacy of cell therapy. It is therefore essential to reevaluate the evidence for the efficacy of cell-based cardiac regeneration therapy, focusing on targets, materials, and methodologies. Meanwhile, the revolutionary innovation of cardiac regeneration therapy is sorely needed to help the millions of people who suffer heart failure from acquired loss of cardiomyocytes. Cardiac regeneration has been used only in limited species or as a developing process in the rodent heart; now, the possibility of cardiomyocyte turnover in the human heart is being revisited. In the pursuit of this concept, the use of cardiac stem/progenitor stem cells in the cardiac niche must be focused to usher in a second era of cardiac regeneration therapy for the severely injured heart. In addition, tissue engineering and cellular reprogramming will advance the next era of treatment that will enable current cell-based therapy to progress to "real" cardiac regeneration therapy. Although many barriers remain, the prevention of refractory heart failure through cardiac regeneration is now becoming a realistic possibility.

Combined hyperthermia and radiotherapy for the treatment of cancer

Radiotherapy is used to treat approximately 50% of all cancer patients, with varying success. Radiation therapy has become an integral part of modern treatment strategies for many types of cancer in recent decades, but is associated with a risk of long-term adverse effects. Of these side effects, cardiac complications are particularly relevant since they not only adversely affect quality of life but can also be potentially life-threatening. The dose of ionizing radiation that can be given to the tumor is determined by the sensitivity of the surrounding normal tissues. Strategies to improve radiotherapy therefore aim to increase the effect on the tumor or to decrease the effects on normal tissues, which must be achieved without sensitizing the normal tissues in the first approach and without protecting the tumor in the second approach. Hyperthermia is a potent sensitizer of cell killing by ionizing radiation (IR), which can be attributed to the fact that heat is a pleiotropic damaging agent, affecting multiple cell components to varying degrees by altering protein structures, thus influencing the DNA damage response. Hyperthermia induces heat shock protein 70 (Hsp70; HSPA1A) synthesis and enhances telomerase activity. HSPA1A expression is associated with radioresistance. Inactivation of HSPA1A and telomerase increases residual DNA DSBs post IR exposure, which correlates with increased cell killing, supporting the role of HSPA1A and telomerase in IR-induced DNA damage repair. Thus, hyperthermia influences several molecular parameters involved in sensitizing tumor cells to radiation and can enhance the potential of targeted radiotherapy. Therapy-inducible vectors are useful for conditional expression of therapeutic genes in gene therapy, which is based on the control of gene expression by conventional treatment modalities. The understanding of the molecular response of cells and tissues to ionizing radiation has lead to a new appreciation of the exploitable genetic alterations in tumors and the development of treatments combining pharmacological interventions with ionizing radiation that more specifically target either tumor or normal tissue, leading to improvements in efficacy.

Primary stroke prevention and hypertension treatment: which is the first-line strategy?

Hypertension (HT) is considered the main classic vascular risk factor for stroke and the importance of lowering blood pressure (BP) is well established. However, not all the benefit of antihypertensive treatment is due to BP reduction per se, as the effect of reducing the risk of stroke differs among classes of antihypertensive agents. Extensive evidences support that angiotensin-converting enzyme inhibitors (ACEI), angiotensin II receptor blockers (ARB), dihydropyridine calcium channel blockers (CCB) and thiazide diuretics each reduced risk of stroke compared with placebo or no treatment. Therefore, when combination therapy is required, a combination of these antihypertensive classes represents a logical approach. Despite the efficacy of antihypertensive therapy a large proportion of the population, still has undiagnosed or inadequately treated HT, and remain at high risk of stroke. In primary stroke prevention current guidelines recommend a systolic/diastolic BP goal of <140/<90 mmHg in the general population and <130/80 mmHg in diabetics and in subjects with high cardiovascular risk and renal disease. The recent release in the market of the fixed-dose combination (FDC) of ACEI or ARB and CCB should provide a better control of BP. However to confirm the efficacy of the FDC in primary stroke prevention, clinical intervention trials are needed.

Coronary computed tomography angiography in coronary artery disease

AIM

To investigate the research directions of coronary computed tomography (CT) angiography in the diagnosis of coronary artery disease (CAD) based on a systematic review of the literature.

METHODS

A search of articles on coronary CT angiography in the diagnosis of CAD was performed during a 6-year-period between 2005 and 2010 from five main radiology journals namely, Radiology, American Journal of Roentgenology, European Radiology, European Journal of Radiology and British Journal of Radiology. Analysis of the references was focused on the research directions of coronary CT angiography with regard to the type of studies in terms of diagnostic value, application of dose-reduction strategies and resultant effective radiation doses with use of these techniques.

RESULTS

One hundred and forty two studies were identified which met the selection criteria and were included in the analysis. 64-slice CT (single source and dual-source CT) dominated 78% of the coronary CT angiography studies. Prior to 2007, research was focused on the diagnostic value of coronary CT angiography, but since 2008 more attention has been paid to radiation dose reduction. Radiation dose was reported in 64 studies, representing 45% of total studies published in the five radiology journals. Various dose-saving strategies have been implemented and prospective electrocardiography-triggering and high pitch techniques were found to be the most effective approaches for radiation dose reduction, with the corresponding mean effective dose being 3.5 ± 1.9 mSv and 1.7 ± 0.6 mSv, respectively.

CONCLUSION

This review shows that the current research in coronary CT angiography has shifted from the previous focus on diagnostic accuracy in CAD to more emphasis on radiation dose reduction.

Oxidative stress and heart failure

Oxidative stress, defined as an excess production of reactive oxygen species (ROS) relative to antioxidant defense, has been shown to play an important role in the pathophysiology of cardiac remodeling and heart failure (HF). It induces subtle changes in intracellular pathways, redox signaling, at lower levels, but causes cellular dysfunction and damage at higher levels. ROS are derived from several intracellular sources, including mitochondria, NAD(P)H oxidase, xanthine oxidase, and uncoupled nitric oxide synthase. The production of ROS is increased within the mitochondria from failing hearts, whereas normal antioxidant enzyme activities are preserved. Chronic increases in ROS production in the mitochondria lead to a catastrophic cycle of mitochondrial DNA (mtDNA) damage as well as functional decline, further ROS generation, and cellular injury. ROS directly impair contractile function by modifying proteins central to excitation-contraction coupling. Moreover, ROS activate a broad variety of hypertrophy signaling kinases and transcription factors and mediate apoptosis. They also stimulate cardiac fibroblast proliferation and activate the matrix metalloproteinases, leading to the extracellular matrix remodeling. These cellular events are involved in the development and progression of maladaptive myocardial remodeling and failure. Oxidative stress is also involved in the skeletal muscle dysfunction, which may be associated with exercise intolerance and insulin resistance in HF. Therefore, oxidative stress is involved in the pathophysiology of HF in the heart as well as in the skeletal muscle. A better understanding of these mechanisms may enable the development of novel and effective therapeutic strategies against HF.

Systematic review of exercise training or percutaneous transluminal angioplasty for intermittent claudication

Background

The aim was to summarize the results of all randomized clinical trials (RCTs) comparing percutaneous transluminal angioplasty (PTA) with (supervised) exercise therapy ((S)ET) in patients with intermittent claudication (IC) to obtain the best estimates of their relative effectiveness.

Methods

A systematic review was performed of relevant RCTs identified from the MEDLINE, Embase and Cochrane Library databases. Eligible RCTs compared PTA with (S)ET, included patients with IC due to suspected or known aortoiliac and/or femoropopliteal artery disease, and compared their effectiveness in terms of functional outcome and/or quality of life (QoL).

Results

Eleven of 258 articles identified (reporting data on eight randomized clinical trials) met the inclusion criteria. One trial included patients with isolated aortoiliac artery obstruction, three trials studied those with femoropopliteal artery obstruction and five included those with combined lesions. Two trials compared PTA with advice on ET, four PTA with SET, two PTA plus SET with SET and two PTA plus SET with PTA. Although the endpoints in most trials comprised walking distances and QoL, pooling of data was impossible owing to heterogeneity. Generally, the effectiveness of PTA and (S)ET was equivalent, although PTA plus (S)ET improved walking distance and some domains of QoL scales compared with (S)ET or PTA alone.

Conclusion

As IC is a common healthcare problem, defining the optimal treatment strategy is important. A combination of PTA and exercise (SET or ET advice) may be superior to exercise or PTA alone, but this needs to be confirmed. Copyright © 2011 British Journal of Surgery Society Ltd. Published by John Wiley & Sons, Ltd.

Perforin-mediated cytotoxicity in non-ST elevation myocardial infarction

The aim of this investigation was to examine the role of perforin (P)-mediated cytotoxicity in the dynamics of tissue damage in patients with non-ST-segment elevation myocardial infarction (NSTEMI) treated with anti-ischaemic drugs. We enrolled 48 patients with NSTEMI in this study [age, 71.5 years; 61.5/76 (median, 25th/75th percentiles)]. The percentage of total peripheral blood P(+) lymphocytes was elevated owing to the increased frequency of P(+) cells within natural killer (NK) subsets, T and NKT cells in patients on day 1 after NSTEMI when compared with healthy controls. Positive correlations were found between cardiac troponin I plasma concentrations and the frequency of P(+) cells, P(+) T cells, P(+) NK cells and their CD56(+dim) and CD56(+bright) subsets during the first week after the NSTEMI. The expression of P in NK cells was accompanied by P-mediated cytotoxicity against K-562 targets at all days examined, except day 21, when an anti-perforin monoclonal antibody did not completely abolish the killing. The percentage of P(+) T cells, P(+) NKT cells and P(+) NK subsets was the highest on the day 1 after NSTEMI and decreased in the post-infarction period. CD56(+) lymphocytes were found in damaged myocardium, suggesting their tissue recruitment. In conclusion, patients with NSTEMI have a strong and prolonged P-mediated systemic inflammatory reaction, which may sustain autoaggressive reactions towards myocardial tissue during the development of myocardial infarction.

Intracoronary melatonin increases coronary blood flow and cardiac function through β-adrenoreceptors, MT1/MT2 receptors, and nitric oxide in anesthetized pigs

Melatonin is involved in the regulation of the cardiovascular system through the modulation of sympathetic function and the nitric oxide (NO)-related pathway and interaction with MT1/MT2 receptors. However, information regarding its direct actions on coronary blood flow and cardiac function is scarce. This study therefore determined the primary in vivo effect of melatonin on cardiac function and perfusion and the involvement of the autonomic nervous system, MT1/MT2 receptors, and NO. In 35 pigs, melatonin infused into the coronary artery at 70 pg for each mL/min of coronary blood flow while preventing changes in heart rate and arterial pressure increased coronary blood flow, dP/dt(max), segmental shortening, and cardiac output by about 12%, 14%, 8%, and 23% of control values (P < 0.05), respectively. These effects were accompanied by an increase in coronary NO release of about 46% (P < 0.05) of control values. The aforementioned responses were graded in a further five pigs. Moreover, the blockade of muscarinic cholinoreceptors (n = 5) and α-adrenoreceptors (n = 5) did not abolish the observed responses to melatonin. After β(1)-adrenoreceptors blocking (n = 5), melatonin failed to affect cardiac function, whereas β(2)-adrenoreceptors (n = 5) and NO synthase inhibition (n = 5) prevented the coronary response and the effect of melatonin on NO release. Finally, all effects were prevented by MT1/MT2 receptor inhibitors (n = 10). In conclusion, melatonin primarily increased coronary blood flow and cardiac function through the involvement of MT1/MT2 receptors, β-adrenoreceptors, and NO release. These findings add new information about the mechanisms through which melatonin physiologically modulates cardiovascular function and exerts cardioprotective effects.

Transcatheter aortic valve replacement (TAVI) — Risk factors for 90-day-mortality

Transcatheter aortic valve implantation (TAVI) has emerged as a promising new treatment option for patients being “too sick” for surgery, with an almost exponentially increasing number of cases done in the recent years. While procedural success is satisfying in any series reported, there still is a lack of information concerning proper patient selection for these procedures. All operations were performed at the Dept. of Cardiovascular Surgery, German Heart Center Munich. From July 2007 to February 2010, a total of 368 patients had transcatheter procedures, 300 of them completed the 90-day-follow-up. Their mean age was 81+/−6 years, 62.7% of them being female. The CoreValve prosthesis was implanted in 213 patients (71%), the femoral route was predominantly used (65%). Among preoperative characteristics, only advanced NYHA-class and tricuspid regurgitation more than moderate were indicators for increased 90-day-mortality. TAVI has become an increasingly safe alternative to open heart aortic valve replacement in patients at high risk for conventional surgery. While there still is room for improvement of intraprocedural steps, the only predictive risk factors for 90-day-mortality were NYHA class IV and high grade tricuspid insufficiency, thus indicating that TAVI puts the patient at an unaccountable high risk.

Paraoxonase 1 (PON1) gene variants are not associated with clopidogrel response

A common functional variant in paraoxonase 1 (PON1), Q192R, was recently reported to be a major determinant of clopidogrel response. This variant was genotyped in 566 participants of the Amish Pharmacogenomics of Anti-Platelet Intervention (PAPI) study and in 227 percutaneous coronary intervention (PCI) patients. Serum paraoxonase activity was measured in a subset of 79 PAPI participants. PON1 Q192R was not associated with pre- or post-clopidogrel platelet aggregation in the PAPI study (P = 0.16 and P = 0.21, respectively) or the PCI cohort (P = 0.47 and P = 0.91, respectively). The Q192 allele was not associated with cardiovascular events (hazard ratio (HR) 0.46, 95% confidence interval (CI) 0.20-1.06; P = 0.07). No correlation was observed between paraoxonase activity and post-clopidogrel platelet aggregation (r(2) < 0.01, P = 0.78). None of 49 additional PON1 variants evaluated was associated with post-clopidogrel platelet aggregation. These findings do not support a role for PON1 as a determinant of clopidogrel response.

Two cases of massive mitral annular calcification mimicking left atrial neoplasms

The authors describe two cases of massive mitral annular calcification, initially picked up on echocardiography and suspected of being neoplastic. Subsequent evaluation by CT scanning confirmed the location, aetiology, structure and diagnosis. Both cases demonstrated large masses, with calcification of varying density. This is likely explained by the presence of the previously reported amorphous caseous material demonstrated to be present within such mass structures. Such a feature is described as caseous degeneration. Both patients described have been managed conservatively with medical therapy, predominantly due to their age and general frailty.

Current characteristics of congenital coronary artery fistulas in adults: A decade of global experience

AIM

To describe the characteristics of coronary artery fistulas (CAFs) in adults, including donor vessels and whether termination was cameral or vascular.

METHODS

A PubMed search was performed for articles between 2000 and 2010 to describe the current characteristics of congenital CAFs in adults. A group of 304 adults was collected. Clinical data, presentations, diagnostic modalities, angiographic fistula findings and treatment strategies were gathered and analyzed. With regard to CAF origin, the subjects were tabulated into unilateral, bilateral or multilateral fistulas and compared. The group was stratified into two major subsets according to the mode of termination; coronary-cameral fistulas (CCFs) and coronary-vascular fistulas (CVFs). A comparison was made between the two subsets. Fistula-related major complications [aneurysm formation, infective endocarditis (IE), myocardial infarction (MI), rupture, pericardial effusion (PE) and tamponade] were described. Coronary artery-ventricular multiple micro-fistulas and acquired CAFs were excluded as well as anomalous origin of the coronary arteries from the pulmonary artery (PA).

RESULTS

A total of 304 adult subjects (47% male) with congenital CAFs were included. The mean age was 51.4 years (range, 18-86 years), with 20% older than 65 years of age. Dyspnea (31%), chest pain (23%) and angina pectoris (21%) were the prevalent clinical presentations. Continuous cardiac murmur was heard in 82% of the subjects. Of the applied diagnostic modalities, chest X-ray showed an abnormal shadow in 4% of the subjects. The cornerstone in establishing the diagnosis was echocardiography (68%), and conventional contrast coronary angiography (97%). However, multi-slice detector computed tomography was performed in 16%. The unilateral fistula originated from the left in 69% and from the right coronary artery in 31% of the subjects. Most patients (80%) had unilateral fistulas, 18% presented with bilateral fistulas and 2% with multilateral fistulas. Termination into the PA was reported in unilateral (44%), bilateral (73%) and multilateral (75%) fistulas. Fistulas with multiple origins (bilateral and multilateral) terminated more frequently into the PA (29%) than into other sites (10.6%) (P = 0.000). Aneurysmal formation was found in 14% of all subjects. Spontaneous rupture, PE and tamponade were reported in 2% of all subjects. In CCFs, the mean age was 46.2 years whereas in CVFs mean age was 55.6 years (P = 0.003). IE (4%) was exclusively associated with CCFs, while MI (2%) was only found in subjects with CVFs. Surgical ligation was frequently chosen for unilateral (57%), bilateral (51%) and multilateral fistulas (66%), but percutaneous therapeutic embolization (PTE) was increasingly reported (23%, 17% and 17%, respectively).

CONCLUSION

Congenital CAFs are currently detected in elderly patients. Bilateral fistulas are more frequently reported and PTE is more frequently applied as a therapeutic strategy in adults.

Pulmonary hypertension in adult Alk1 heterozygous mice due to oxidative stress

AIMS

Mutations in the ALK1 gene, coding for an endothelial-specific receptor of the transforming growth factor-β superfamily, are the underlying cause of hereditary haemorrhagic telangiectasia type 2, but are also associated with familial pulmonary hypertension (PH). We assessed the lung vasculature of mice with a heterozygous deletion of Alk1 (Alk1(+/-)) for disease manifestations and levels of reactive O(2) species (ROS) implicated in both disorders.

METHODS AND RESULTS

Several signs of PH, including elevated right ventricular (RV) systolic pressure leading to RV hypertrophy, reduced vascular density, and increased thickness and outward remodelling of pulmonary arterioles, were observed in 8- to 18-week-old Alk1(+/-) mice relative to wild-type littermate controls. Higher ROS lung levels were also documented. At 3 weeks, Alk1(+/-) mice were indistinguishable from controls and were prevented from subsequently developing PH when treated with the anti-oxidant Tempol for 6 weeks, confirming a role for ROS in pathogenesis. Levels of NADPH oxidases and superoxide dismutases were higher in adults than newborns, but unchanged in Alk1(+/-) mice vs. controls. Prostaglandin metabolites were also normal in adult Alk1(+/-) lungs. In contrast, NO production was reduced, while endothelial NO synthase (eNOS)-dependent ROS production was increased in adult Alk1(+/-) mice. Pulmonary near resistance arteries from adult Alk1(+/-) mice showed less agonist-induced force and greater acetylcholine-induced relaxation; the later was normalized by catalase or Tempol treatment.

CONCLUSION

The increased pulmonary vascular remodelling in Alk1(+/-) mice leads to signs of PH and is associated with eNOS-dependent ROS production, which is preventable by anti-oxidant treatment.

Apoptotic effects of hydrogen peroxide and vitamin C on chicken embryonic fibroblasts: redox state and programmed cell death

The pro-apoptotic effects of hydrogen peroxide and the purported anti-apoptotic effects of Vitamin C on chicken embryonic fibroblasts were investigated. Hydrogen peroxide induced morphological changes in a dose dependent manner, and a myriad of autophagosomes were observed using transmission electron microscopy. Doxorubicin elicited alterations were not inhibited by co-incubation with Vitamin C except that mitochondrial structure was slightly improved. TUNEL assay, cytotoxicity analysis and flow cytometry revealed that the cytotoxicity, DNA fragmentation and apoptotic rates were dose dependent upon treatment with hydrogen peroxide. Calcium homeostasis was disrupted in a dose dependent manner, and cell cycle was blocked at G(2)/M checkpoint at low concentration and S/G(2) checkpoint at high concentration respectively upon treatment with hydrogen peroxide. The administration of Vitamin C only has a modest effect against doxorubicin induced apoptosis, calcium homeostasis disruption and cell cycle arrest. This research demonstrated that the elevation of reactive oxygen species is sufficient to induce the apoptosis of chicken embryonic fibroblasts, whereas the administration of Vitamin C does not necessarily have certain anti-apoptotic effects, especially when the stimulus is not directly linked with redox state.

Assessment of systolic and diastolic function in heart failure using ambulatory monitoring with acoustic cardiography

INTRODUCTION. The circadian variation of heart function and heart sounds in patients with and without heart failure (HF) is poorly understood. We hypothesized HF patients would exhibit less circadian variation with worsened cardiac function and sleep apnea. METHODS. We studied 67 HF patients (age 67.4 ± 8.2 years; 42% acute HF) and 63 asymptomatic control subjects with no history of HF (age 61.6 ± 7.7 years). Subjects wore a heart sound/ECG/respiratory monitor. The data were analyzed for sleep apnea, diastolic heart sounds, and systolic time intervals. RESULTS. The HF group had significantly greater prevalence of the third heart sound and prolongation of electro-mechanical activation time, while the control group had an age-related increase in the prevalence of the fourth heart sound. The control group showed more circadian variation in cardiac function. The HF subjects had more sleep apnea and higher occurrence of heart rate non-dipping. CONCLUSIONS. The control subjects demonstrated an increasing incidence of diastolic dysfunction with age, while systolic function was mostly unchanged with aging. Parameters related to systolic function were significantly worse in the HF group with little diurnal variation, indicating a constant stimulation of sympathetic tone in HF and reduction of diurnal regulation.

Significance of clopidogrel resistance related to the stent-assisted angioplasty in patients with atherosclerotic cerebrovascular disease

OBJECTIVE

To evaluate the prevalence and risk factors of clopidogrel resistance, and association between thromboembolic complications and clopidogrel resistance in patient with stent-assisted angioplasty for atherosclerotic cerebrovascular disease.

METHODS

Between September 2006 and June 2008, clopidogrel resistance test was performed on 41 patients who underwent stent-assisted angioplasty for atherosclerotic cerebrovascular disease. It was performed before drug administration and about 12 hours after drug administration (loading dose : 300 mg, maintain dose : 75 mg). Two patients were excluded, and 41 patients were included (mean : 67.59±7.10 years, age range : 41-79). Among 41 patients, 18 patients had intracranial lesions, and 23 had extracranial lesions. We evaluated the prevalence, risk factors and complications related to clopidogrel resistance.

RESULTS

Twenty-one patients (51.2%) showed clopidogrel resistance [intracranial : 10 patients (55.6%), extracranial : 11 patients (47.8%)] and no clopidogrel resistance was seen in 20 patients. Hypercholesterolemia was an indepedent risk factor of clopidogrel resistance. Stent-assisted angioplasty was technically successful in all patients, but acute in-stent thrombosis occurred in 5 patients with intracranial lesions (4 patients with clopidogrel resistance and 1 without clopidogrel resistance). Acute thrombi were completely lysed after intra-arterial infusion of abciximab.

CONCLUSION

There was relatively high prevalence of clopidogrel resistance in patients with atherosclerotic cerebrovascular disease. Hypercholesterolemia was an independent predictive factor of clopidogrel resistance. Acute in-stent thrombosis was more frequently seen in the clopidogrel resistant group. Therefore, clopidogrel resistance test should be performed to avoid thromboembolic complications related to stent-assisted angioplasty for atherosclerotic cerebrovascular disease, especially patients with hypercholeterolemia and intracranial lesion.

Renal function in advanced heart failure

Despite recent advances with neurohormonal antagonists and devices, the prognosis of patients with advanced heart failure (HF) remains grave. Renal dysfunction is a common comorbid condition in HF and is associated with adverse outcomes. Current evidence indicates that intrinsic renal disease and inflammation in HF makes the kidney susceptible to hemodynamic compromise and congestion and contributes to a great extent to the development of renal dysfunction. Relief of congestion requires combination treatment with diuretics, neurohormonal antagonists, and occasionally vasodilators as well as inotropes. However, high doses of diuretics may accelerate the development of renal dysfunction by increasing neurohumoral activity and inducing renal structural and functional changes. Ultrafiltration should be reserved for patients with true diuretic resistance. Finally, early identification of the "patient at risk" remains a challenging issue and is limited by the currently used conventional parameters of renal function. However, novel biomarkers of acute kidney ischemia and/or injury are emerging and promise to become a diagnostic option for this patient population.

Advanced malignant lung disease: what the specialist can offer

Lung cancer is not only the most commonly diagnosed cancer worldwide, but it is still the leading cause for cancer-related death. The 5-year survival for lung cancer in Europe and in the USA is totally 16%. Therefore, a palliative therapy regimen is required to control the disease and reduce symptoms with the objective of enhancing quality of life of lung cancer patients. In addition to chemotherapy that is still one of the most important pillars in the treatment of advanced lung cancer, further interventional strategies can be offered to improve a patient's quality of life. A locoregional tumour progression is frequently associated with malignant pleural effusion or pericardial effusion, central airway obstruction, tracheo-oesophageal fistula, severe haemoptysis or superior vena cava (SVC) syndrome threatening life and necessitating urgent palliation. Recurrent pleural effusion causing dyspnoea can be managed by pleurodesis, serial thoracocentesis or insertion of an indwelling catheter. Symptomatic malignant pericardial effusion often requires an urgent pericardiocentesis. Furthermore, surgical procedures, instillation of sclerosing agents or local chemotherapy should be considered in refractory pericardial effusion. The therapy regimen of central airway stenosis includes mechanical and thermic endoscopic procedures providing rapid relief of symptoms. To prevent recurrence of airway obstruction, the insertion of a stent or palliative brachytherapy provide re-establishment of the patency of obstructed airways. Haemoptysis can be managed by bronchoscopic interventions as well as by arterial embolization or palliative thoracic radiotherapy. The therapy of SVC syndrome is dependent of histology. In small-cell lung cancer, chemotherapy is recommended. In non-small-cell lung cancer, stent insertion and/or radiotherapy are the therapeutic pillars.

Association of serum omentin-1 levels with coronary artery disease

AIM

Omentin-1, a novel adipokine expressed in visceral adipose tissue, is negatively correlated with insulin resistance and obesity. Decreased omentin-1 expression has been found in many chronic inflammatory diseases. However, the role of omentin-1 in coronary artery disease (CAD) has not been elucidated. The aim of the present study was to determine whether serum concentration of omentin-1 was independently associated with CAD.

METHODS

One hundred and fifty five patients with CAD were divided into two groups: acute coronary syndrome (ACS) and stable angina pectoris (SAP). A total of 52 healthy participants served as controls. Serum concentrations of omentin-1 and interleukin-6 (IL-6) were measured using ELISA. The association of omentin-1 with CAD and cardiovascular disease risk factors was evaluated.

RESULTS

Serum omentin-1 levels were lower in patients with ACS or SAP compared with controls (ACS, 113.08±61.43 ng/mL; SAP, 155.41±66.89 ng/mL; control, 254.00±72.9 ng/mL; P<0.01). Patients with ACS also had lower serum concentrations of omentin-1 compared with patients with SAP (P<0.01). Serum concentration of omentin-1 was negatively correlated with body mass index (r=-0.17, P<0.05) and serum IL-6 concentration (r=-0.19, P<0.05). Furthermore, multiple logistic regression analysis showed that serum omentin-1 concentrations were independently correlated with CAD.

CONCLUSION

The findings suggest that serum concentrations of omentin-1 are related to CAD.

Heart regeneration

Heart failure plagues industrialized nations, killing more people than any other disease. It usually results from a deficiency of specialized cardiac muscle cells known as cardiomyocytes, and a robust therapy to regenerate lost myocardium could help millions of patients every year. Heart regeneration is well documented in amphibia and fish and in developing mammals. After birth, however, human heart regeneration becomes limited to very slow cardiomyocyte replacement. Several experimental strategies to remuscularize the injured heart using adult stem cells and pluripotent stem cells, cellular reprogramming and tissue engineering are in progress. Although many challenges remain, these interventions may eventually lead to better approaches to treat or prevent heart failure.

Oxidative stress in cardiovascular inflammation: its involvement in autoimmune responses

Recently, it has become clear that atherosclerosis is a chronic inflammatory disease in which inflammation and immune responses play a key role. Accelerated atherosclerosis has been reported in patients with autoimmune diseases, suggesting an involvement of autoimmune mechanisms in atherogenesis. Different self-antigens or modified self-molecules have been identified as target of humoral and cellular immune responses in patients with atherosclerotic disease. Oxidative stress, increasingly reported in these patients, is the major event causing structural modification of proteins with consequent appearance of neoepitopes. Self-molecules modified by oxidative events can become targets of autoimmune reactions, thus sustaining the inflammatory mechanisms involved in endothelial dysfunction and plaque development. In this paper, we will summarize the best characterized autoantigens in atherosclerosis and their possible role in cardiovascular inflammation.

Marine carotenoids and cardiovascular risk markers

Marine carotenoids are important bioactive compounds with physiological activities related to prevention of degenerative diseases found principally in plants, with potential antioxidant biological properties deriving from their chemical structure and interaction with biological membranes. They are substances with very special and remarkable properties that no other groups of substances possess and that form the basis of their many, varied functions and actions in all kinds of living organisms. The potential beneficial effects of marine carotenoids have been studied particularly in astaxanthin and fucoxanthin as they are the major marine carotenoids. Both these two carotenoids show strong antioxidant activity attributed to quenching singlet oxygen and scavenging free radicals. The potential role of these carotenoids as dietary anti-oxidants has been suggested to be one of the main mechanisms for their preventive effects against cancer and inflammatory diseases. The aim of this short review is to examine the published studies concerning the use of the two marine carotenoids, astaxanthin and fucoxanthin, in the prevention of cardiovascular diseases.

[Reflex syncope : diagnosis and therapy]

Reflex-mediated syncope is a common cause for syncope. The first step in evaluating the cause of syncope is to assess the risk of a life-threatening cause for syncope, e.g., ventricular arrhythmias. Reflex-mediated syncope has to be differentiated from orthostatic syncope. In orthostatic syncope, there is an insufficient autonomic response. In contrast to a reflex-mediated syncope, in which the autonomic nervous system acts inappropriately, reflex-mediated syncope is classified into the classical vasovagal form, the situational form, or due to carotid sinus hypersensitivity. In the elderly, often a mixed form is present. Treatment is difficult. Most important is educating the patient and avoiding precipitating factors. Physical maneuvers, e.g., counter pressure maneuvers, are more effective than drug treatment. Permanent pacing is rarely needed. However, before indicating a pacemaker, a correlation between bradycardia and syncope should be documented. This is often only possible by implanting a monitoring device at an early stage.

Diagnosis and management of pericardial effusion

Pericardial effusion is a common finding in everyday clinical practice. The first challenge to the clinician is to try to establish an etiologic diagnosis. Sometimes, the pericardial effusion can be easily related to a known underlying disease, such as acute myocardial infarction, cardiac surgery, end-stage renal disease or widespread metastatic neoplasm. When no obvious cause is apparent, some clinical findings can be useful to establish a diagnosis of probability. The presence of acute inflammatory signs (chest pain, fever, pericardial friction rub) is predictive for acute idiopathic pericarditis irrespective of the size of the effusion or the presence or absence of tamponade. Severe effusion with absence of inflammatory signs and absence of tamponade is predictive for chronic idiopathic pericardial effusion, and tamponade without inflammatory signs for neoplastic pericardial effusion. Epidemiologic considerations are very important, as in developed countries acute idiopathic pericarditis and idiopathic pericardial effusion are the most common etiologies, but in some underdeveloped geographic areas tuberculous pericarditis is the leading cause of pericardial effusion. The second point is the evaluation of the hemodynamic compromise caused by pericardial fluid. Cardiac tamponade is not an "all or none" phenomenon, but a syndrome with a continuum of severity ranging from an asymptomatic elevation of intrapericardial pressure detectable only through hemodynamic methods to a clinical tamponade recognized by the presence of dyspnea, tachycardia, jugular venous distension, pulsus paradoxus and in the more severe cases arterial hypotension and shock. In the middle, echocardiographic tamponade is recognized by the presence of cardiac chamber collapses and characteristic alterations in respiratory variations of mitral and tricuspid flow. Medical treatment of pericardial effusion is mainly dictated by the presence of inflammatory signs and by the underlying disease if present. Pericardial drainage is mandatory when clinical tamponade is present. In the absence of clinical tamponade, examination of the pericardial fluid is indicated when there is a clinical suspicion of purulent pericarditis and in patients with underlying neoplasia. Patients with chronic massive idiopathic pericardial effusion should also be submitted to pericardial drainage because of the risk of developing unexpected tamponade. The selection of the pericardial drainage procedure depends on the etiology of the effusion. Simple pericardiocentesis is usually sufficient in patients with acute idiopathic or viral pericarditis. Purulent pericarditis should be drained surgically, usually through subxiphoid pericardiotomy. Neoplastic pericardial effusion constitutes a more difficult challenge because reaccumulation of pericardial fluid is a concern. The therapeutic possibilities include extended indwelling pericardial catheter, percutaneous pericardiostomy and intrapericardial instillation of antineoplastic and sclerosing agents. Massive chronic idiopathic pericardial effusions do not respond to medical treatment and tend to recur after pericardiocentesis, so wide anterior pericardiectomy is finally necessary in many cases.

Clinical evidence of interaction between clopidogrel and proton pump inhibitors

Clopidogrel is approved for reduction of atherothrombotic events in patients with cardiovascular (CV) and cerebrovascular disease. Dual antiplatelet therapy with aspirin and clopidogrel decreases the risk of major adverse cardiac events after acute coronary syndrome or percutaneous coronary intervention, compared with aspirin alone. Due to concern about gastrointestinal bleeding in patients who are receiving clopidogrel and aspirin therapy, current guidelines recommend combined use of a proton pump inhibitor (PPI) to decrease the risk of bleeding. Data from previous pharmacological studies have shown that PPIs, which are extensively metabolized by the cytochrome system, may decrease the ADP-induced platelet aggregation of clopidogrel. Results from retrospective cohort studies have shown a higher incidence of major CV events in patients receiving both clopidogrel and PPIs than in those without PPIs. However, other retrospective analyses of randomized clinical trials have not shown that the concomitant PPI administration is associated with increased CV events among clopidogrel users. These controversial results suggest that large specific studies are needed. This article reviews the metabolism of clopidogrel and PPIs, existing clinical data regarding the interaction between clopidogrel and PPIs, and tries to provide recommendations for health care professionals.

Five different phenotypes of endothelial cell cultures from the bovine corpus luteum: present outcome and role of potential dendritic cells in luteolysis

Progress in understanding the background of structural luteolysis depends on insights into the physiological function of innate immunity (INIM), in particular the presence of dendritic cells (DCs) in the corpus luteum (CL). For this reason, the cultures of five endothelial cell-like phenotypes derived from the bovine CL and their long-lasting analysis (morphology, function, and origin) become important. Types 1 and 2 represent microvascular endothelial cells with cytokeratin (CK) expression, assumed to be danger-sensing cells. Types 3 and 4 express features of common endothelial cells. Type 5 indicates a steroidogenic cell type, which could be derived from steroidogenic CK(+) cells in the CL of development after loss of CK expression. Type 5 is a promising candidate to become a mature DC. It might act with the microvascular CK(+) cell/type 1 like a luteovascular unit, which connects INIM with adaptive/cell-mediated immunity (ADIM) in structural luteolysis.

Insulin resistance and other metabolic risk factors in the pathogenesis of hepatocellular carcinoma

Coinciding with the increased incidence of hepatocellular carcinoma (HCC), there has been a significant increase in the global incidence of obesity and diabetes mellitus (DM), the two major risk factors for nonalcoholic steatohepatitis (NASH). There are many causes of HCC, and nonalcoholic fatty liver disease/NASH is now emerging as a leading risk factor owing to the epidemic of obesity and type 2 DM. The mechanisms leading to HCC in obesity and type 2 DM likely involve interactions between several signaling pathways, including oxidative stress, inflammation, oncogenes, adiponectins, and insulin resistance associated with visceral adiposity and diabetes.

Pharmacological management of atrial fibrillation: one, none, one hundred thousand

atrial fibrillation (AF) is associated with a significant burden of morbidity and increased risk of mortality. Antiarrhythmic drug therapy remains a cornerstone to restore and maintain sinus rhythm for patients with paroxysmal and persistent AF based on current guidelines. However, conventional drugs have limited efficacy, present problematic risks of proarrhythmia and cause significant noncardiac organ toxicity. Thus, inadequacies in current therapies for atrial fibrillation have made new drug development crucial. New antiarrhythmic drugs and new anticoagulant agents have changed the current management of AF. This paper summarizes the available evidence regarding the efficacy of medications used for acute management of AF, rhythm and ventricular rate control, and stroke prevention in patients with atrial fibrillation and focuses on the current pharmacological agents.

Use of the oral platelet inhibitors dipyridamole and acetylsalicylic acid is associated with increased risk of fracture

BACKGROUND

Platelet inhibitors are widely used in the treatment and prevention of coronary artery disease. In addition to acetylsalicylic acid, two major groups of platelet inhibitors are used; phosphodiesterase inhibitors including dipyridamole, and thienopyridines (ticlopidine and clopidogrel). Clopidogrel is the most widely used, and in combination with acetylsalicylic acid it is the standard of care for acute coronary syndromes and percutaneous coronary interventions. However, the modes of action involve pathways that are involved in the metabolic activity in bone cells and pharmacologic modulation of these pathways may therefore have effects on bone.

METHODS

In the current study, we assessed the association between platelet inhibitor use and fracture incidence in a population-based epidemiological study performed within the Danish population consisting of approximately 5.3 million individuals, where all patients sustaining a fracture during the year of 2000 were included (124,655 cases). The hypotheses were to investigate if use of thienopyridines or phosphodiesterase inhibitors were associated with increased risk of fractures after adjustment for potential confounders.

RESULTS

We found that treatment with dipyridamole is associated with increased overall fracture risk, but not to the risk of osteoporotic fractures. In contrast, low-dose acetylsalicylic acid is associated to increased risk of overall fractures and fractures of the hip. Finally, in the current study clopidogrel is not associated with increased fracture risk.

CONCLUSIONS

Use of some oral platelet inhibitors is associated with increased risk of fractures, and more studies are warranted to determine the potential effect of platelet inhibitors on bone metabolism in vivo.

Targeting soluble guanylate cyclase for the treatment of pulmonary hypertension

Pulmonary arterial hypertension is a disease characterized by a sustained increase in pulmonary arterial pressure leading to right heart failure. Current treatments focus on endothelial dysfunction and an aberrant regulatory pathway for vascular tone. Unfortunately, a large proportion of patients are unresponsive to conventional vasodilator therapy. Investigations are ongoing into the effects of experimental therapies targeting the signal transduction pathway that mediates vasodilation. Here, we briefly discuss the pathophysiology of pulmonary hypertension and endothelial dysfunction, along with current treatments. We then present a focused review of recent animal studies and human trials examining the use of activators and stimulators of soluble guanylate cyclase for the treatment of pulmonary arterial hypertension and chronic thromboembolic pulmonary hypertension.

Neurovascular dysfunction, inflammation and endothelial activation: implications for the pathogenesis of Alzheimer's disease

Alzheimer's disease (AD) is an age-related disorder characterized by progressive cognitive decline and dementia. Alzheimer's disease is an increasingly prevalent disease with 5.3 million people in the United States currently affected. This number is a 10 percent increase from previous estimates and is projected to sharply increase to 8 million by 2030; it is the sixth-leading cause of death. In the United States the direct and indirect costs of Alzheimer's and other dementias to Medicare, Medicaid and businesses amount to more than $172 billion each year. Despite intense research efforts, effective disease-modifying therapies for this devastating disease remain elusive. At present, the few agents that are FDA-approved for the treatment of AD have demonstrated only modest effects in modifying clinical symptoms for relatively short periods and none has shown a clear effect on disease progression. New therapeutic approaches are desperately needed. Although the idea that vascular defects are present in AD and may be important in disease pathogenesis was suggested over 25 years ago, little work has focused on an active role for cerebrovascular mechanisms in the pathogenesis of AD. Nevertheless, increasing literature supports a vascular-neuronal axis in AD as shared risk factors for both AD and atherosclerotic cardiovascular disease implicate vascular mechanisms in the development and/or progression of AD. Also, chronic inflammation is closely associated with cardiovascular disease, as well as a broad spectrum of neurodegenerative diseases of aging including AD. In this review we summarize data regarding, cardiovascular risk factors and vascular abnormalities, neuro- and vascular-inflammation, and brain endothelial dysfunction in AD. We conclude that the endothelial interface, a highly synthetic bioreactor that produces a large number of soluble factors, is functionally altered in AD and contributes to a noxious CNS milieu by releasing inflammatory and neurotoxic species.

Relationship of autonomic imbalance and circadian disruption with obesity and type 2 diabetes in resistant hypertensive patients

Background

Hypertension, diabetes and obesity are not isolated findings, but a series of interacting interactive physiologic derangements. Taking into account genetic background and lifestyle behavior, AI (autonomic imbalance) could be a common root for RHTN (resistant hypertension) or RHTN plus type 2 diabetes (T2D) comorbidity development. Moreover, circadian disruption can lead to metabolic and vasomotor impairments such as obesity, insulin resistance and resistant hypertension. In order to better understand the triggered emergence of obesity and T2D comorbidity in resistant hypertension, we investigated the pattern of autonomic activity in the circadian rhythm in RHTN with and without type 2 diabetes (T2D), and its relationship with serum adiponectin concentration.

Methods

Twenty five RHTN patients (15 non-T2D and 10 T2D, 15 males, 10 females; age range 34 to 70 years) were evaluated using the following parameters: BMI (body mass index), biochemical analysis, serum adiponectinemia, echocardiogram and ambulatory electrocardiograph heart rate variability (HRV) in time and frequency domains stratified into three periods: 24 hour, day time and night time.

Results

Both groups demonstrated similar characteristics despite of the laboratory analysis concerning T2D like fasting glucose, HbA1c levels and hypertriglyceridemia. Both groups also revealed disruption of the circadian rhythm: inverted sympathetic and parasympathetic tones during day (parasympathetic > sympathetic tone) and night periods (sympathetic > parasympathetic tone). T2D group had increased BMI and serum triglyceride levels (mean 33.7 ± 4.0 vs 26.6 ± 3.7 kg/m² - p = 0.00; 254.8 ± 226.4 vs 108.6 ± 48.7 mg/dL - p = 0.04), lower levels of adiponectin (6729.7 ± 3381.5 vs 10911.5 ± 5554.0 ng/mL - p = 0.04) and greater autonomic imbalance evaluated by HRV parameters in time domain compared to non-T2D RHTN patients. Total patients had HRV correlated positively with serum adiponectin (r = 0.37 [95% CI -0.04 - 1.00] p = 0.03), negatively with HbA1c levels (r = -0.58 [95% CI -1.00 - -0.3] p = 0.00) and also adiponectin correlated negatively with HbA1c levels (r = -0.40 [95% CI -1.00 - -0.07] p = 0.02).

Conclusion

Type 2 diabetes comorbidity is associated with greater autonomic imbalance, lower adiponectin levels and greater BMI in RHTN patients. Similar circadian disruption was also found in both groups indicating the importance of lifestyle behavior in the genesis of RHTN.