Effects of cytokines on nitric oxide pathways in human vasculature

In Vivo Vasospasm Induction by Ultrasound Application in the Chicken Chorioallantoic Membrane Model

Cerebral vasospasm is a highly investigated phenomenon in neurovascular research. Experimental vasospasm models are irreplaceable for the evaluation of new antivasospastic drugs. In this study, we assessed the reliability of in vivo vasospasm induction by ultrasound application in the chicken chorioallantoic membrane (CAM) model. After incubation of fertilized chicken eggs for four days, a fenestration was performed to enable examination of the CAM vessels. On the thirteenth day, continuous-wave ultrasound (3 MHz, 1 W/cm²) was applied on the CAM vessels for 60 s. The ultrasound effect on the vessels was recorded by life imaging (5-MP HD-microscope camera, Leica®). The induced vessel diameter changes were evaluated in a defined time interval of 20 min using a Fiji macro. The vessel diameter before and after sonication was measured and the relative diameter reduction was determined. A first reduction of vessel diameter was observed after three minutes with an average vessel-diameter decrease to 77%. The maximum reduction in vessel diameter was reached eight minutes after sonication with an average vessel diameter decrease to 57% (mean relative diameter reduction of 43%, range 44–61%), ANOVA, p = 0.0002. The vasospasm persisted for all 20 recorded minutes post induction. Vasospasm can be reliably induced by short application of 3 MHz-ultrasound to the CAM vessels. This might be a suitable in vivo model for the evaluation of drug effects on vasospasm in an experimental setting as intermediary in the transition process from in vitro to in vivo assessment using animal models.

The association of pulse pressure with metabolic syndrome in Korean elderly: A nationwide population-based study

AIMS

Metabolic syndrome (MetS) is one of the most important issues in elderly people because of its association with ensuing cardiovascular disease (CVD). The components of MetS play a key role in the pathogenesis of arterial thickness and stiffness. Pulse pressure (PP), an easily accessible parameter in a basic health evaluation, has been documented as a marker of arterial stiffness and widespread atherosclerosis. The aim of our study was to assess the association between PP and MetS in Korean elderly people.

METHODS

A nationwide cross-sectional study was conducted to examine the relationship between PP and MetS among 6187 participants (2687 men and 3500 women) aged 60years older Korean people using the Korean National Health and Nutrition Examination Survey. The odds ratios (ORs) and 95% confidence intervals (CIs) for MetS were calculated across PP quartiles using multiple logistic regression analyses.

RESULTS

There was a positive relationship between PP and MetS in a dose-response manner. The prevalence of MetS significantly increased with increasing PP quartile in both men and women (p<0.001). Compared with the lowest PP quartile group, the ORs (95% CIs) for MetS of the highest PP quartile was 2.60 (1.91-3.52) for men and 1.97 (1.48-2.59) for women after adjusting for age, cigarette smoking, alcohol intake, regular exercise and mean arterial blood pressure. These associations remained valid after additionally adjusting for hypertension and diabetes medications.

CONCLUSION

We found a positive relationship between PP and MetS among Korean elderly men and women.

High neutrophil-to-lymphocyte ratio is associated with increased carotid artery intima-media thickness in type 2 diabetes

Aims/Introduction

Emerging evidence suggests that the neutrophil‐to‐lymphocyte ratio (NLR) is a novel potential marker of inflammatory responses. The objective was to evaluate the association between NLR and carotid artery intima‐media thickness (cIMT) in type 2 diabetes.

Materials and Methods

We carried out a case–control study involving 320 patients with type 2 diabetes, and 250 age‐, sex‐ and body mass index‐matched healthy controls who all underwent carotid ultrasonography and took a blood examination. We divided the diabetes patients into two groups according to cIMT: 188 diabetes patients with high cIMT and 132 diabetes patients with low cIMT, and compared baseline characteristics and NLR between the two groups and healthy controls.

Results

The mean NLR was significantly higher in the group of diabetes patients with high cIMT than the group of diabetes patients with low cIMT, who in turn showed a significantly higher NLR compared with control participants. Logistic regression analysis showed that the NLR was an independent risk factor for diabetes patients with high cIMT (odds ratio 140.89, 95% CI 1.71–11615.30, P = 0.028). Based on the receiver operating characteristic curve, use of the NLR as an indicator for diabetes patients with high cIMT diagnosis was projected to be 3.16, and yielded a sensitivity and specificity of 36.2% and 93.2%, respectively, with an area under the curve of 0.606 (95% CI 0.544–0.667).

Conclusions

High NLR might be a potential biomarker for the increased cIMT in type 2 diabetes patients. Future studies are required to validate our findings.

The Effect of Perioperative Ischemia and Reperfusion on Multiorgan Dysfunction following Abdominal Aortic Aneurysm Repair

Abdominal aortic aneurysms (AAAs) are relatively common and are potentially life-threatening medical problems. The aim of this review is to provide an overview of the effect of I/R injury on multiorgan failure following AAA repair. The PubMed, CINAHL, EMBASE, Medline, Cochrane Review, and Scopus databases were comprehensively searched for articles concerning the pathophysiology of I/R and its systemic effects. Cross-referencing was performed using the bibliographies from the articles obtained. Articles retrieved were restricted to those published in English. One of the most prominent characteristics of AAA open repair is the double physiological phenomenon of ischemia-reperfusion (I/R) that happens either at the time of clamping or following the aortic clamp removal. Ischemia-reperfusion injury causes significant pathophysiological disturbances to distant organs, increasing the possibility for postoperative multiorgan failure. Although tissue injury is mediated by diverse mechanisms, microvascular dysfunction seems to be the final outcome of I/R.

Expression of Surfactant Protein-A during LPS-Induced Otitis Media with Effusion in Mice

OBJECTIVE

The objective of this study was to investigate the expression and role of surfactant protein (SP) in the middle ear throughout lipopolysaccharide (LPS)-induced otitis media with effusion (OME).

STUDY DESIGN

Randomized case-controlled animal model.

SETTING

Shandong University, Jinan, China.

SUBJECTS AND METHODS

SP expression was monitored using reverse transcription polymerase chain reaction (PCR) in normal mice (n = 5). Two groups, control phosphate-buffered saline-injected mice (n = 5) and LPS-injected mice (n = 5), were euthanized 5 days following injection. RNA was extracted for reverse transcription PCR and real-time PCR, and temporal bone samples were used for hematoxylin and eosin staining. LPS was injected into mice, and 5 mice per test were euthanized at 0, 12, 24, 48, 72, and 96 hours following injection. For mRNA expression quantification, reverse transcription PCR and real-time PCR were performed, and proinflammatory cytokine levels were measured by enzyme-linked immunosorbent assay.

RESULTS

SP-A and SP-D expression was detected in normal murine Eustachian tubes. SP-A expression was up-regulated after LPS-induced OME (P = .01). At various time points after LPS injection, concentrations of proinflammatory cytokines (tumor necrosis factor-α [TNF-α], interleukin (IL)-1β, and IL-6) in the middle ear increased significantly (P < .05) and correlated with changes in SP-A expression.

CONCLUSION

SP-A and SP-D exist in the murine middle ear. The expression of SP-A and TNF-α, IL-1β, and IL-6 was up-regulated in the middle ear of the LPS-induced OME animal model.

Relationship of Neutrophil-to-Lymphocyte Ratio with Aortic Stiffness in Type 1 Diabetes Mellitus

OBJECTIVES

Emerging evidence suggests that the neutrophil-to-lymphocyte ratio (NLR) may be a useful marker of inflammation and aortic stiffness. Markers of inflammation and aortic stiffness are both indicators of cardiovascular events. We, therefore, investigated whether the NLR is associated with aortic stiffness in patients with type 1 diabetes mellitus.

METHODS

We examined the relationship of the NLR to aortic stiffness in 76 people with type 1 diabetes and 36 healthy controls.

RESULTS

The NLRs in the group with type 1 diabetes were higher than in the controls (2.33±0.95 vs. 1.80±0.68, respectively; p=0.003). Aortic strain and aortic distensibility, the parameters of aortic stiffness, measured noninvasively by the help of echocardiography, were significantly decreased in the patient group compared to controls (8.0%±1.5% vs. 13.1%±3.3 %; p<0.001 and 3.6±1.1 cm(2).dyn(-1).10(-3) vs. 6.0±2.1 cm(2).dyn(-1).10(-3); p<0.001, respectively). There were negative correlations between NLR and distensibility (r: -0.40; p<0.001) and strain (r: -0.57; p<0.001) in patients with type 1 diabetes.

CONCLUSIONS

We have demonstrated that there is a significant negative correlation between the NLR and markers of aortic stiffness in patients with type 1 diabetes, indicating a potential association between inflammation and arterial stiffness. Accordingly, a higher NLR may be a useful additional measure in determining the cardiovascular risks of patients with type 1 diabetes in our clinical practice.

Diagnostic potential of differentially expressed Homer1, IL-1β, and TNF-α in coronary artery disease

Increasing evidences suggest that inflammation plays an important role in the pathogenesis of coronary artery disease (CAD). Numerous inflammatory cytokines and related genes mediate adverse cardiovascular events in patients with CAD, such as interleukin-1β (IL-1β), tumor necrosis factor-α (TNF-α), and Homer in the present study. The study was carried out on 163 CAD patients at different stages and 68 controls. The gene expression of Homer1, Homer2, Homer3, IL-1β, and TNF-α in the peripheral blood leukocytes were measured by real-time polymerase chain reaction. The mRNA levels of Homer1, IL-1β, and TNF-α in CAD patients were significantly higher than those in the control group, but not Homer2 and Homer3. However, there was no considerable difference in the mRNA levels of Homer1, IL-1β, and TNF-α among AMI, UAP, and SAP three subgroups of CAD. The receiver operating characteristic (ROC) curves showed that Homer1 had a better diagnostic value for UAP patients compared with IL-1β and TNF-α. Like IL-1β and TNF-α, Homer1 may also be an important participant of atherosclerotic plaque development and eventually rupture. The results of the present study may provide an important basis for diagnosing CAD patients, and provide new therapeutic targets for CAD.

Carotid intima-media thickness is predicted by combined eotaxin levels and severity of hepatic steatosis at ultrasonography in obese patients with Nonalcoholic Fatty Liver Disease

BACKGROUND

Non-Alcoholic Fatty Liver Disease (NAFLD) is a distinct coronary artery disease (CAD) risk factor. The atherosclerotic process predisposing to CAD includes altered lipid profile and inflammatory processes. The available evidence suggests that increased circulating levels of eotaxin, an eosinophil chemoattractant cytokine implicated in allergic responses, are detected in the serum of patients with CAD. Relationships were sought between serum eotaxin on the one hand, and intima-media thickness--an early predictor of the atherosclerotic process, hepatic steatosis, arterial blood pressure values, as well as inflammation/immune markers and angiogenetic factors--on the other.

METHODS

Eighty obese patients with NAFLD, diagnosed at ultrasonography, without evident cytolysis, formed our study population. Anthropometric measures, metabolic profile, serum concentrations of interleukin-1β, C-reactive protein, interleukin-6, fibrinogen, ferritin, TNF-α, spleen size, vascular endothelial growth factor, platelet-derived growth factor-BB and heat shock protein-70 were evaluated.

RESULTS

Serum eotaxin concentrations were distinctly associated with TNF α, IL-6, IL-1β, VEGF and PDGF-BB levels but not with CRP, fibrinogen, heat shock protein-70 or spleen size. Among the metabolic and anthropometric parameters, a significant predictive power emerged when comparing eotaxin to insulin resistance, expressed as HOMA. NAFLD was distinctly associated with HOMA (P = 0.0005). Intima-media thickness was well predicted by both eotaxin levels and severity of NAFLD at ultrasonography, although no relation was detected between these last two variables.

DISCUSSION AND CONCLUSION

A role for insulin resistance in mediating the interplay between eotaxin and other inflammation/immune parameters could be evidenced in the induction/maintenance of atherosclerosis of obese patients with NAFLD.

The impact of acute mental stress on vascular endothelial function: evidence, mechanisms and importance

Cardiovascular disease is a principle cause of morbidity and mortality worldwide, and it has a complex etiology that involves lifestyle factors such as psychosocial stress. Recent evidence suggests that temporary impairments in vascular endothelial cell function may contribute to the relationship between stress and cardiovascular disease. Indeed, impaired endothelial function has been observed to occur transiently (lasting up to 1.5h) following mental stress, and such periods of impairment could accumulate to become clinically relevant over the long term. The finding of acute stress induced endothelial dysfunction is not universal however, and both physiological (e.g. sympathetic nervous system and hypothalamic-pituitary-adrenal axis reactivity), and methodological factors contribute to the conflicting results. A clear understanding of the interaction between stress response activation and endothelial function is critical to elucidating the complexities of the relationship between psychosocial stress and cardiovascular disease. Therefore, the purpose of this review is: 1) to briefly describe the importance of vascular endothelial function and how it is assessed, 2) to review the literature investigating the impact of acute mental stress on endothelial function in humans, identifying factors that may explain contradictory results, and 3) to summarize our current understanding of the mechanisms that may mediate an acute mental stress-endothelial function interaction.

Effects of Korean Red Ginseng on Cardiovascular Risks in Subjects with Metabolic Syndrome: a Double-blind Randomized Controlled Study

Background

This study investigated the effects of Korean red ginseng (KRG) supplementation on metabolic parameters, inflammatory markers, and arterial stiffness in subjects with metabolic syndrome.

Methods

We performed a randomized, double-blind, placebo-controlled, single-center study in 60 subjects who were not taking drugs that could affect metabolic and vascular functions. Subjects were randomized into either a KRG (4.5 g/d) group or a placebo group for a 12-week study. We collected anthropometric measurements, blood for laboratory testing, and brachial-ankle pulse wave velocity (baPWV) at the initial (week 0) and final (week 12) visits.

Results

A total of 48 subjects successfully completed the study protocol. Oral administration of KRG did not significantly affect blood pressure, oxidative or inflammatory markers, or baPWV.

Conclusion

We found no evidence that KRG had an effect on blood pressure, lipid profile, oxidized low density lipoprotein, fasting blood glucose, or arterial stiffness in subjects with metabolic syndrome. These findings warrant subsequent longer-term prospective clinical investigations with a larger population.

Trial Registration

ClinicalTrials.gov Identifier: NCT00976274

The relationship between arterial stiffness and nonalcoholic fatty liver disease

AIM

Nonalcoholic fatty liver disease (NAFLD) is currently the most common form of chronic liver disease and some studies have documented its link with cardiovascular risk factors. This study aimed to investigate the association between arterial stiffness and NAFLD.

METHODS

Among 1,442 health check-up subjects (955 men, 487 women), we examined the association between brachial-ankle pulse wave velocity (baPWV) as a measurement of arterial stiffness and the presence of NAFLD based on abdominal sonographic findings. Multivariate linear and logistic regression analyses were conducted to examine the independent association between baPWV and the presence of NAFLD in gender-specific manners.

RESULTS

In multivariate regression analysis, NAFLD was found to be independently associated with baPWV in both men and women. Moreover, in multivariate logistic regression analysis, a graded independent relation was found between higher levels of baPWV and the prevalence risk of NAFLD. Odds ratios (95% CI) for the highest vs. the lowest quartile of baPWV were 1.85 (range, 1.13-2.62) in men and 3.32 (1.45-7.62) in women after adjusting for age, smoking status, regular exercise, body mass index, blood pressure, fasting plasma glucose, triglyceride, HDL-cholesterol, hypertension and diabetes.

CONCLUSION

Arterial stiffness was independently associated with the prevalence risk for NAFLD regardless of classical CVD risk factors.

Vascular effects of glycoprotein130 ligands--part I: pathophysiological role

The vessel wall is no longer considered as only an anatomical barrier for blood cells but is recognized as an active endocrine organ. Dysfunction of the vessel wall occurs in various disease processes including atherosclerosis, hypertension, peripheral artery disease, aneurysms, and transplant and diabetic vasculopathies. Different cytokines were shown to modulate the behavior of the cells, which constitute the vessel wall such as immune cells, endothelial cells and smooth muscle cells. Glycoprotein 130 (gp130) is a common cytokine receptor that controls the activity of a group of cytokines, namely, interleukin (IL)-6, oncostatin M (OSM), IL-11, ciliary neurotrophic factor (CNTF), leukemia inhibitory factor (LIF), cardiotrophin-1 (CT-1), cardiotrophin-like cytokine (CLC), IL-27, and neuropoietin (NP). Gp130 and associated cytokines have abundantly diverse functions. Part I of this review focuses on the pathophysiological functions of gp130 ligands. We specifically describe vascular effects of these molecules and discuss the respective underlying molecular and cellular mechanisms.

Association between resting heart rate and arterial stiffness in Korean adults

BACKGROUND

Higher resting heart rate, a simple and useful indicator of autonomic balance and metabolic rate, has emerged as an independent predictor for atherosclerotic cardiovascular disease.

AIM

To determine the association between resting heart rate and arterial stiffness measured by brachial-ankle pulse wave velocity (baPWV).

METHODS

We examined the association between resting heart rate and baPWV in 641 Korean adults (366 men, 275 women) in a health examination program. A high baPWV was defined as greater than 1450 cm/s (>75th percentile). The odds ratios for high baPWVs were calculated using multivariable logistic regression analysis after adjusting for confounding variables across heart rate quartiles (Q1<or=56, Q2=57-62, Q3=63-68, Q4>or=69 beats/min).

RESULTS

Age-adjusted baPWV mean values increased gradually with heart rate quartile (Q1=1281, Q2=1285, Q3=1354, Q4=1416 cm/s). The odds ratios (95% confidence intervals) for high baPWVs in each heart rate quartile were 1.00, 1.28 (0.57-2.86), 2.63 (1.20-5.79) and 3.66 (1.66-8.05), respectively, after adjusting for age, sex, smoking status, alcohol intake, exercise, body mass index, hypertension medication, diabetes medication, hyperlipidaemia medication, mean arterial blood pressure, fasting plasma glucose, total cholesterol, triglycerides, high-density lipoprotein cholesterol, white blood cell count, aspartate aminotransferase, alanine aminotransferase, gamma-glutamyltransferase and uric acid.

CONCLUSION

These findings indicate that a higher resting heart rate is independently associated with arterial stiffness. Accordingly, early detection of increased resting heart rate is important for preservation of arterial function and assessment of cardiovascular risk.

Elevated white blood cell count is associated with arterial stiffness

BACKGROUND AND AIMS

White blood cell (WBC) count, a usual marker of systemic inflammation, is known to be associated with atherosclerotic cardiovascular disease. The aim of the present study was to determine the association of WBC count with arterial stiffness measured by brachial-ankle pulse wave velocity (baPWV).

METHODS AND RESULTS

We examined the association between WBC count and baPWV in 788 Korean adults (375 men, 413 women) in a health examination program. The odds ratios for a high baPWV were calculated using multivariate logistic regression analysis after adjusting for confounding variables across WBC count quartiles (Q1: <or=5190, Q2: 5200-6080, Q3: 6090-7310, and Q4: >or=7320 cells/mm(3)). A high baPWV was defined as more than 1440 cm/s (>75th percentile). Age-adjusted baPWV mean values gradually increased with WBC quartiles (Q1=1294, Q2=1322, Q3=1347, and Q4=1367 cm/s). The odds ratios (95% CI) for a high baPWV in each WBC count quartile were 1.00, 1.34 (0.61-3.00), 2.20 (0.96-5.06), and 2.69 (1.15-6.47) after adjusting for age, sex, cigarette smoking, alcohol intake, regular exercise, body mass index (BMI), mean arterial blood pressure, fasting plasma glucose, triglyceride, HDL-cholesterol, gamma-glutamyltransferase (GGT), and uric acid.

CONCLUSION

These findings indicate that elevated WBC count is associated with arterial stiffness. Accordingly, early detection of an elevated WBC count is important for arterial function and the assessment of cardiovascular risk.

Expert opinion on tilarginine in the treatment of shock

Tilarginine is L-N-monomethyl arginine (L-NMMA) or N(G)-monomethyl-L-arginine HCL, a non-selective inhibitor of nitric oxide synthase (NOS), which has been studied in the treatment of septic shock and cardiogenic shock complicating myocardial infarction. Despite strong evidence that excessive nitric oxide (NO) production plays a pivotal role in the pathogenesis of septic shock and may contribute to the pathogenesis of cardiogenic shock complicating myocardial infarction, outcome studies in these two disorders have proved disappointing. L-NMMA therapy was associated with an excess mortality, particularly at doses > 5 mg/(kg h), in septic shock whereas the effects of a lower dose (1 mg/(kg h)) in cardiogenic shock complicating myocardial infarction were neutral. The excess mortality in patients with septic shock was almost certainly the result of unfavourable haemodynamic changes induced by L-NMMA (decreased cardiac output, increased pulmonary vascular resistance and reduced tissue oxygen delivery) whereas the lack of benefit in patients with cardiogenic shock complicating myocardial infarction may have been because the dose of L-NMMA was too low. Further studies of L-NMMA at doses < 5 mg/(kg h) in conjunction with inotrope support may produce more beneficial results. Conversely, the use of a selective inducible NOS inhibitor to reduce the pathological effects of excessive NO production although leaving the beneficial effects of vascular NO production by endothelial NOS unaltered may prove to be of value.

New and emerging risk factors for CVD

Morphological and immunocytochemical studies have elucidated the complex processes involved in atherogenesis. The notion of plaque instability has emerged from this work and underscored the importance of inflammation in determining clinical complications associated with atherosclerosis, such as acute coronary syndrome. Cells of the immune system have been detected within atherosclerotic lesions and auto-antibodies directed against modified LDL and heat-shock proteins have been identified in the blood of individuals with atherosclerosis. The use of risk 'engines', e.g. the Framingham coronary risk score, has facilitated the identification of individuals at high risk, but the constituent classical risk factors used in these algorithms do not adequately differentiate individuals at moderate risk. As age is a major component of the equations used in these algorithms they are not particularly useful in young adults, and their applicability to non-Caucasian populations has been questioned. Biomarkers of early disease and plaque instability have therefore both been sought. Although some of these markers have been shown individually to be associated with a significant hazard ratio, no substantial improvement in discrimination has been demonstrated when they are incorporated into a risk 'engine'. The latter has generally been assessed by receiver operator characteristic curve analysis, although this approach has been criticised. Other modalities, including imaging and functional assessments of vascular function, are now being developed for clinical use.

Inducible nitric oxide synthase (iNOS) gene polymorphism in pre-eclampsia: a pilot study in North India

BACKGROUND

Pre-eclampsia is one of the most frequent complications of pregnancy, however, little is known about its aetiology.

AIMS

The objective of this study was to investigate the association between inducible nitric oxide synthase (iNOS) genotypes and pre-eclampsia. We also measured the concentrations of tumour necrosis factor-alpha (TNF-alpha), nitric oxide (NO) and superoxide dismutase (SOD) in patients with pre-eclampsia to evaluate their relations to the single nucleotide polymorphisms (SNPs) observed.

METHODS

This cross-sectional study included 30 pregnant women with pre-eclampsia and 30 healthy pregnant women. They were screened at 28th, 36th weeks of gestation and just after delivery (within 48 h), and their blood samples were analysed for NO, SOD, TNF-alpha and iNOS gene polymorphism.

RESULTS

Patients with pre-eclampsia at 36 weeks gestation showed significantly increased serum NO levels (P=0.007), whereas SOD activity was decreased significantly (P=0.004). A doublefold increase was observed in TNF-alpha levels at 36 weeks in patients with pre-eclampsia (P=0.003) which decreased significantly (P=0.001) after delivery. A total of four SNPs were observed, of which two (G300A exon 8 and G274T exon 16) showed statistically significant association with pre-eclampsia. When compared, G274T exon 16 SNP also showed association with TNF-alpha levels and SOD activity in pre-eclamptic patients.

CONCLUSION

As pre-eclampsia is a disease of multifactorial aetiopathology, NO, TNF-alpha, SOD activity and NOS2A polymorphism might play an intermingled role in its development.

Inter-relationships of indices of endothelial damage/dysfunction [circulating endothelial cells, von Willebrand factor and flow-mediated dilatation] to tissue factor and interleukin-6 in acute coronary syndromes

BACKGROUND

Increased circulating endothelial cells (CECs, reflecting endothelial damage) in acute coronary syndromes (ACS) has been reported. However, the inter-relationships of indices of endothelial damage/injury with development of vascular (dys)function, plasma levels of tissue factor (TF, an index of coagulation) and interleukin-6 (IL-6, a pro-inflammatory cytokine) have not been investigated in ACS. We hypothesized that increased CECs can be related to impaired flow-mediated vasodilatation (FMD, an index of endothelial dysfunction) and elevated plasma von Willebrand factor (vWf, also marking endothelial damage/dysfunction), TF and IL-6 in patients with ACS.

METHODS

We studied 120 patients with ACS (80 acute myocardial infarction and 40 unstable angina; 86 male, age 65+/-12 years) and 40 matched patients with stable CAD and 40 healthy controls (HC) in a cross-sectional analysis. Plasma vWf, TF and IL-6 levels were measured by ELISA. CECs were quantified using epifluorescence microscope after immunomagnetic separation with CD146. Brachial artery FMD was assessed in a subset of 39 ACS patients.

RESULTS

ACS patients had significantly higher CECs, vWf, TF and IL-6 levels, but lower FMD, when compared to stable CAD and HC (all p<0.001) and all were inter-correlated significantly. In ACS, CECs was strongly correlated with FMD (r=-0.64, p<0.001) and TF (r=0.7, p<0.001). In stable CAD, significant correlations were again found between many indices, but on multivariate analysis, IL-6 and vWf were both independently related to FMD.

CONCLUSIONS

Increased CECs in ACS patients are closely associated with endothelial damage/dysfunction (vWf and FMD), coagulation (TF) and inflammation (IL-6). These inter-relationships support the concept of a central role of endothelial damage/injury in the activation of vascular and coagulation abnormalities in ACS.

Genetic polymorphisms and cerebral palsy in very preterm infants

In the present study, we examine whether selected genetic polymorphisms contribute to the development of cerebral palsy (CP) in very preterm infants. Subjects were 96 singleton infants with later-diagnosed CP and 119 control children, white non-Hispanic (n for CP=74, controls=88) or white Hispanic (CP=22, controls=31), born <32 wk gestation. Presence of CP was identified through state service agencies, with review of medical records. DNA extracted from archived neonatal blood was genotyped using multi-locus polymerase chain reaction amplification and immobilized sequence-specific oligonucleotide probes. Single nucleotide polymorphisms (SNPs) showing evidence of association with development of CP were endothelial nitric oxide synthase (eNOS) A(-922)G, factor 7 (F7) arg353gln and del(-323)10bp-ins, and lymphotoxin A (LTA) thr26asn. In white non-Hispanic children, beta-2 adrenergic receptor gln27glu was associated with CP risk; in Hispanic children, plasminogen activator inhibitor-1 (PAI-1) 4G(-675)5G and G11053T were associated with risk of CP. In a logistic regression considering these SNPs simultaneously in non-Hispanics, an association with CP was observed for heterozygotes of eNOS -922 (OR 3.0, CI 1.4-6.4), F7 (OR 2.7, CI 1.1-6.5), LTA (OR 2.1, CI 1.0-4.6), and PAI-1 (OR 3.2, CI 1.2-8.7). Factor 5, Factor 2, methylene tetrahydrofolate reductase, tumor necrosis factor-alpha, and other SNPs tested were not significantly associated with CP risk. We conclude that further study of genetic factors that may influence susceptibility to CP in very preterm infants is warranted.

Endothelial function in HIV-infected patients receiving protease inhibitor therapy: does immune competence affect cardiovascular risk?

BACKGROUND

The use of HIV protease inhibitors (PIs) as a component of combination antiretroviral therapy in HIV-infected patients has been associated with dyslipidaemia, but its significance as a risk factor for cardiovascular disease is unclear. Endothelial dysfunction is an early phase of atherogenesis that may be assessed non-invasively with ultrasonography in vivo.

AIM

To evaluate vascular function and investigate potential determinants of endothelial dysfunction of the peripheral circulation in PI-treated, HIV-infected men with dyslipidaemia.

DESIGN

Observational, case-control study.

METHODS

We studied 24 HIV-infected, PI-treated men with dyslipidaemia and 24 normolipidaemic, healthy male controls matched for age and body mass index. Brachial artery endothelial function was studied using high-resolution ultrasound and computerized edge-detection software. This non-invasive technique measured post-ischaemic flow-mediated dilatation (FMD), and the endothelium-independent vasodilatory response to glyceryl trinitrate (GTN).

RESULTS

Within the HIV patient group, FMD was significantly associated with percentage of 'naïve' CD4 + 45RA + T cells (p = 0.03), while plasma lipid/lipoprotein and insulin levels, body mass, and smoking status did not correlate with endothelial function. FMD was not significantly different between the study group and the controls.

CONCLUSIONS

The atherogenic potential of PI-associated dyslipidaemia may be attenuated in HIV-infected patients with decreased immune competence, reflecting a possible contribution of cell-mediated immune responses to the pathogenesis of atherosclerosis.

Can coenzyme Q10 improve vascular function and blood pressure? Potential for effective therapeutic reduction in vascular oxidative stress

Coenzyme Q10 (CoQ) is an endogenously synthesised compound that acts as an electron carrier in the mitochondrial electron transport chain. The presence of adequate tissue concentrations of CoQ may be important in limiting oxidative and nitrosative damage in vivo. Oxidative and nitrosative stress are likely to be elevated in conditions such as diabetes and hypertension. In these conditions elevated oxidative and nitrosative stress within the arterial wall may contribute to increased blood pressure and vascular dysfunction. The major focus of this review is the potential of CoQ to improve vascular function and lower blood pressure. Although there is substantial indirect support for the putative mechanism of effect of CoQ on the vascular system, to date there is little direct support for an effect of CoQ on in vivo markers of oxidative or nitrosative stress. The limited data available from studies in animal models and from human intervention studies are generally consistent with a benefit of CoQ on vascular function and blood pressure. The observed effects of CoQ on these endpoints are potentially important therapeutically. However, before any firm clinical recommendations can be made about CoQ supplementation, further intervention studies in humans are needed to investigate the effects of CoQ on vascular function, blood pressure and cardiovascular outcomes. The particularly relevant groups of patients for these studies are those with insulin resistance, type 2 diabetes, hypertension and the metabolic syndrome.

Leukocyte count and vascular function in Type 2 diabetic subjects with treated hypertension

BACKGROUND

Traditional cardiovascular risk factors may only partially explain abnormal vascular function in Type 2 diabetic patients. This study examined the associations between vascular function and markers of inflammation in Type 2 diabetic subjects with treated hypertension.

METHODS

Flow-mediated dilatation (FMD) and glyceryl-trinitrate mediated dilatation (GTNMD) of the brachial artery were used to assess endothelium-dependent and -independent function, respectively, in 29 hypertensive Type 2 diabetic subjects (HbA1c <9%), and 17 healthy control subjects. Plasma C-reactive protein (CRP), fibrinogen, interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-alpha), and leukocyte count were used as markers of inflammation. Soluble L-selectin, P-selectin, and von Willebrand factor (vWf) were measured to assess leukocyte, platelet and endothelial cell activation, respectively.

RESULTS

Compared with controls, diabetic subjects had impaired FMD (3.9+/-3.0 vs. 5.5+/-2.4%, P=0.07) and GTNMD (11.4+/-4.8% vs. 15.4+/-7.1%, P=0.04). They also had higher levels of CRP (2.7+/-2.6 vs. 1.4+/-1.1 mg/l, P=0.03), fibrinogen (3.4+/-0.7 vs. 2.7+/-0.3 g/l, P<0.001) and TNF-alpha (20.9+/-13.4 vs. 2.5+/-1.7 pg/l, P<0.001). In diabetic subjects, after adjustment for age and gender, leukocyte count was an independent predictor of FMD (P=0.02), accounting for 17% of total variance. Similarly, leukocyte count (P<0.001) accounted for 23% and IL-6 (P=0.03) for 12% of the variance in GTNMD. vWf was correlated with leukocyte count (r=0.38, P=0.04), FMD (r=-0.35, P=0.06) and GTNMD (r=-0.47, P=0.009), whilst P-selectin correlated with fibrinogen (r=0.58, P=0.001).

CONCLUSION

These cross-sectional observations are consistent with the hypothesis that reduced FMD and GTNMD in Type 2 diabetes is at least in part secondary to increased inflammation, with associated endothelial and platelet activation.

Interleukin-10 protects nitric oxide-dependent relaxation during diabetes: role of superoxide

Interleukin (IL)-10, an anti-inflammatory cytokine, preserves endothelial function during acute inflammation. We tested the hypotheses that IL-10 plays a protective role in blood vessels during diabetes by suppressing impairment of endothelium-dependent relaxation and that protection by IL-10 is mediated by effects on superoxide (O(2-)). Streptozotocin (150 mg/kg i.p.) or citrate buffer was injected into IL-10-deficient (IL-10(-/-)) mice and wild-type controls (IL-10(+/+)). In IL-10(+/+) and IL-10(-/-) mice, blood glucose levels were approximately 120 mg/dl after citrate administration and approximately 400 mg/dl after streptozotocin administration. Vasorelaxation was examined in arteries in vitro 12-16 weeks later. Maximum relaxation to acetylcholine (30 micromol/l) was 88 +/- 3% (means +/- SE) in nondiabetic mice and 84 +/- 3% in diabetic IL-10(+ /+) mice (P > 0.05). Thus, at this time point, diabetes did not impair endothelium-dependent relaxation in vessels in wild-type mice. In contrast, maximum relaxation in vessels from diabetic IL-10(-/-) mice was significantly decreased (74 +/- 5%) compared with nondiabetic IL-10(-/-) mice (93 +/- 2%, P < 0.05). Superoxide dismutase with polyethylene glycol (PEG-SOD) restored impaired responses to acetylcholine to levels seen in controls. Responses to acetylcholine also were improved by allopurinol (an inhibitor of xanthine oxidase) in vessels from diabetic IL-10(- /-) mice. Thus, diabetes produces greater impairment of relaxation to acetylcholine in IL-10(-/-) mice than in IL-10(+/ +) mice. These findings provide direct evidence that IL-10 impedes mechanisms of endothelial dysfunction during diabetes. Restoration of vasorelaxation with PEG-SOD or allopurinol suggests that the mechanism(s) by which IL-10 preserves endothelium-dependent vasorelaxation involves O(2-), perhaps by reducing production of O(2-) by xanthine oxidase.

A strong initial systemic inflammatory response is associated with higher corticosteroid requirements and longer duration of therapy in patients with giant-cell arteritis

OBJECTIVE

To assess whether the intensity of the initial systemic inflammatory response is able to predict response to therapy in patients with giant cell arteritis (GCA).

METHODS

Retrospective review of 75 patients (49 women and 26 men) with biopsy-proven GCA who had regular followup and were treated according to uniform criteria. Four parameters were used to evaluate the baseline inflammatory response at diagnosis: fever, weight loss, erythrocyte sedimentation rate > or = 85 mm/hour, and hemoglobin < 110 gm/liter. Patients were considered to have a weak inflammatory response if they had 2 or fewer inflammatory parameters (group 1) and a strong inflammatory response if 3 or 4 parameters were present (group 2). Time required to achieve a maintenance dose of less than 10 mg prednisone/day was recorded and analyzed by the Kaplan-Meier survival analysis method. Tumor necrosis factor alpha (TNFalpha) and interleukin 6 (IL-6) serum levels were also determined in 62 patients and 15 controls.

RESULTS

Forty patients had a weak (group 1) and 35 had a strong (group 2) initial inflammatory response. Patients in group 2 had significantly higher levels of circulating TNFalpha (31.9 +/- 16.8 versus 22.3 +/- 9 pg/ml; P = 0.01) and IL-6 (28.2 +/- 17.4 versus 16.6 +/- 13 pg/ml; P = 0.004) than patients in group 1. In group 1, 50% of patients required a median of 40 weeks (95% CI 37-43) to reach a maintenance dose of <10 mg, whereas in group 2 a median of 62 weeks (95% CI 42-82) was necessary (P = 0.0062). Patients in group 2 experienced more flares than patients in group 1 (P = 0.01) and received higher cumulative steroid doses (8.974 +/- 3.939 gm versus 6.893 +/- 3.075 gm; P = 0.01).

CONCLUSION

GCA patients with a strong initial systemic inflammatory reaction have more elevated circulating levels of IL-6 and TNFalpha, have higher and more prolonged corticosteroid requirements, and experience more disease flares during corticosteroid therapy than patients with a weak systemic acute phase response.

Cytokines and inflammatory pathways in the pathogenesis of multiple organ failure following abdominal aortic aneurysm repair

Multiple organ failure is a common mode of death following abdominal aortic aneurysm repair, particularly after rupture. Cytokines are the principal mediators of the inflammatory response to injury and high levels of circulating cytokines have been associated with poor outcome in major trauma and sepsis. Abdominal aortic aneurysm repair results in an ischaemia-reperfusion injury to the tissues distal to the site of aortic clamping. The inflammatory response in these tissues causes the release of cytokines, principally Interleukins 1-beta, 6, and 8, and Tumour Necrosis Factor alpha. If released in large enough concentrations, these cytokines may enter the circulation and gain access to organs distant to the site of initial injury. Circulating cytokines cause dysfunction of the renal, cardiovascular, respiratory, nervous and musculo-skeletal systems. The combination of these individual changes in organ function is the multiple-organ dysfunction syndrome, which may progress to multiple organ failure.

Lactoferrin peptide increases the survival of Candida albicans-inoculated mice by upregulating neutrophil and macrophage functions, especially in combination with amphotericin B and granulocyte-macrophage colony-stimulating factor

To develop a new strategy to control candidiasis, we examined in vivo the anticandidal effects of a synthetic lactoferrin peptide, FKCRRWQWRM (peptide 2) and the peptide that mimics it, FKARRWQWRM (peptide 2'). Although all mice that underwent intraperitoneal injection of 5 x 10(8) Candida cells with or without peptide 2' died within 8 or 7 days, respectively, the survival times of mice treated with 5 to 100 microg of intravenous peptide 2 per day for 5 days after the candidal inoculation were prolonged between 8.4 +/- 2.9 and 22.4 +/- 3.6 days, depending on the dose of peptide 2. The prolongation of survival by peptide 2 was also observed in mice that were infected with 1.0 x 10(9) Candida albicans cells (3.2 +/- 1.3 days in control mice versus 8.2 +/- 2.4 days in the mice injected with 10 microg of peptide 2 per day). In the high-dose inoculation, a combination of peptide 2 (10 microg/day) with amphotericin B (0.1 microg/day) and granulocyte-macrophage colony-stimulating factor (GM-CSF) (0.1 microg/day) brought prolonged survival. With a combination of these agents, 60% of the mice were alive for more than 22 days. Correspondingly, peptide 2 activated phagocytes inducing inducible NO synthase and the expression of p47(phox) and p67(phox), and peptide 2 increased phagocyte Candida-killing activities up to 1.5-fold of the control levels upregulating the generation of superoxide, lactoferrin, and defensin from neutrophils and macrophages. These findings indicated that the anticandidal effects of peptide 2 depend not only on the direct Candida cell growth-inhibitory activity, but also on the phagocytes' upregulatory activity, and that combinations of peptide 2 with GM-CSF and antifungal drugs will help in the development of new strategies for control of candidiasis.

Mycophenolate mofetil prevents salt-sensitive hypertension resulting from angiotensin II exposure

BACKGROUND

Interstitial mononuclear cell infiltration is a feature of experimental models of salt-sensitive hypertension (SSHTN). Since several products of these cells are capable of modifying local vascular reactivity and sodium reabsorption, we investigated whether mycophenolate mofetil (MMF), a drug known to inhibit infiltration and proliferation of immune cells, would modify the SSHTN induced by angiotensin II (Ang II) infusion.

METHODS

Sprague-Dawley rats received Ang II for two weeks using subcutaneous minipumps. A high-sodium (4% NaCl) diet was started on the third week and was maintained until the eighth week. MMF (30 mg/kg, N = 15), an immunosuppressive drug, or vehicle (N = 15) was given daily by gastric gavage during the initial three weeks. Sham-operated rats (N = 9) were used as controls. Body weight, blood pressure (tail-cuff plethysmography), and serum creatinine were determined weekly. Urinary malondialdehyde (MDA) excretion, renal histology, and immunohistology, including the presence of Ang II and superoxide-producing cells, were analyzed at the end of Ang II infusion and at eight weeks.

RESULTS

MMF treatment did not modify hypertension induced during exogenous Ang II infusion, but prevented the subsequent SSHTN. Tubulointerstitial injury resulting from Ang II infusion was significantly reduced by MMF treatment, as were proliferative activity, T-cell infiltration and activation (interleukin-2 receptor expression), superoxide-producing cells, and urinary MDA excretion. Ang II-producing cells were present in the renal tubulointerstitium of rats with SSHTN (60 +/- 30 Ang II-positive cells/mm(2) at 8 weeks) and were reduced by two thirds in the MMF-treated group. Forty percent of lymphocytes infiltrating the tubulointerstitium stained positive for Ang II. The expression of Ang II receptors in the kidney was unmodified.

CONCLUSIONS

SSHTN resulting from Ang II infusion is associated with infiltration and activation of immune cells that produce Ang II. MMF treatment reduces these features and prevents the development of SSHTN.

Role of immunocompetent cells in nonimmune renal diseases

Renal infiltration with macrophages and monocytes is a well-recognized feature of not only immune, but also nonimmune kidney disease. This review focuses on the investigations that have shown accumulation of immunocompetent cells in experimental models of acute and chronic ischemia, protein overload, hypercholesterolemia, renal ablation, obstructive uropathy, polycystic kidney disease, diabetes, aging, murine hypertension, and nephrotoxicity. We examine the mechanisms of infiltration of immunocompetent cells and their participation in the self-perpetuating cycle of activation of the angiotensin system, generation of reactive oxygen species, and further recruitment of monocytes and lymphocytes. We also discuss the possibility of antigen-dependent and antigen-independent mechanisms of immune cell activation in these animal models. Finally, we review the recent studies in which suppression of cellular immunity with mycophenolate mofetil has proven beneficial in attenuating or preventing the progression of renal functional and histologic damage in experimental conditions of nonimmune nature.

The metabotropic glutamate receptor system protects against ischemic free radical programmed cell death in rat brain endothelial cells

As one of the key determinants of ischemic injury, cerebrovascular endothelial cell (EC) degeneration may be dependent upon the generation of the free radical nitric oxide (NO) and the subsequent induction of programmed cell death (PCD). Although the mechanisms that can prevent EC injury are most likely multifactorial in origin, the metabotropic glutamate receptor (mGluR) system may represent a novel therapeutic approach for ECs given the ability of the mGluR system to reverse neuronal cell injury. This study examined the modulation of individual subtypes of mGluRs during anoxia and NO toxicity in primary rat cerebrovascular ECs. Cell injury was determined through trypan blue dye exclusion, intracellular lactate dehydrogenase release, DNA fragmentation, membrane phosphatidylserine (PS) exposure, and cysteine protease activity. Anoxia, through the generation of NO, and exposure to exogenous NO were directly toxic to ECs. Exposure to NO rapidly decreased EC viability from 98% +/- 2% to 40% +/- 9%, increased DNA fragmentation from 2% +/- 2% to 61% +/- 9%, and increased membrane PS exposure from 3% +/- 3% to 66% +/- 6% over a 24-hour period. Activation of the mGluR system significantly increased EC survival through the prevention of NO-induced DNA fragmentation and cellular membrane PS residue exposure. In contrast, antagonism of the mGluR system failed to prevent PCD. Cytoprotection by the mGluR system was dependent, at least in part, upon the direct inhibition of NO-generated caspase 1- and caspase 3-like activities. Further investigation into the ability of the mGluR system to prevent PCD in ECs may open new therapeutic avenues for the treatment of cerebrovascular injury.

IL-10 deficiency increases superoxide and endothelial dysfunction during inflammation

Little is known about the role of interleukin-10 (IL-10), an anti-inflammatory cytokine, in blood vessels. We used IL-10-deficient mice (IL-10 -/-) to examine the hypothesis that IL-10 protects endothelial function after lipopolysaccharide (LPS) treatment. The responses of carotid arteries were studied in vitro 6 h after injection of a relatively low dose of LPS (10 microgram ip). In IL-10 -/- mice, the maximum relaxation to ACh (3 microM) was 56 +/- 6% (means +/- SE) after LPS injection and 84 +/- 4% after vehicle injection (P < 0.05). Thus endothelium-dependent relaxation was impaired in carotid arteries from IL-10 -/- mice after LPS injection. In contrast, this dose of LPS did not alter relaxation to ACh in vessels from wild-type (IL-10 +/+) mice. Relaxation to nitroprusside and papaverine was similar in arteries from both IL-10 -/- and IL-10 +/+ mice after vehicle or LPS injection. Because inflammation is associated with increased levels of reactive oxygen species, we also tested the hypothesis that superoxide contributes to the impairment of endothelial function by LPS in the absence of IL-10. Results using confocal microscopy and hydroethidine indicated that levels of superoxide are elevated in carotid arteries from IL-10 -/- mice compared with IL-10 +/+ mice after LPS injection. The impaired relaxation of arteries from IL-10 -/- mice after LPS injection was restored to normal by polyethylene glycol-suspended superoxide dismutase (50 U/ml) or allopurinol (1 mM), an inhibitor of xanthine oxidase. These data provide direct evidence that IL-10 protects endothelial function after an acute inflammatory stimulus by limiting local increases in superoxide. The source of superoxide in this model may be xanthine oxidase.