Postconditioning protects against human endothelial ischaemia-reperfusion injury via subtype-specific KATP channel activation and is mimicked by inhibition of the mitochondrial permeability transition pore

AIMS

Intermittent early reperfusion (ischaemic postconditioning; PostC) reduces ischaemia-reperfusion (IR) injury. Using an in vivo model of endothelial IR injury in humans, we sought to determine the role of K(ATP) channels in PostC and whether inhibition of the mitochondrial permeability transition pore (mPTP) at the onset of reperfusion protected against endothelial IR injury.

METHODS AND RESULTS

Endothelial function (EF) in healthy volunteers was assessed using vascular ultrasound to measure the percentage increase in the diameter of the brachial artery in response to reactive hyperaemia [flow-mediated dilatation (FMD)]. In resistance vessels, venous occlusion plethysmography was used to measure the dilator response to acetylcholine (ACh) [area under ACh dose-response curve (ACh AUC)]. Measurements were made before and after IR injury. Ischaemic postconditioning consisted of three 10 s cycles of alternating ischaemia and reperfusion in the first minute of reperfusion. Oral glibenclamide and glimepiride were used to determine the role of K(ATP) channel subtypes in PostC. Intra-arterial cyclosporine was used to determine the role of mPTP in endothelial IR injury. Ischaemia-reperfusion reduced EF in the brachial artery (FMD 7.1 ± 0.9% pre-IR, 2.8 ± 0.4% post-IR; P < 0.001) and resistance vessels [ACh AUC (×10(4)) 2.1 ± 0.4 pre-IR, 1.5 ± 0.2 post-IR; P < 0.05]. Ischaemic postconditioning preserved EF in the brachial artery [FMD 6.8 ± 0.9% (P < 0.001 vs. post-IR)] and resistance vessels [ACh AUC (×10(4)) 1.9 ± 0.2 (P < 0.001 vs. post-IR)]. Protection by PostC was abolished by glibenclamide in the brachial artery [FMD 3.3 ± 0.2% (P < 0.001 vs. post-IR + PostC)] and in resistance vessels [ACh AUC (×10(4)) 1.1 ± 0.2 (P < 0.001 vs. post-IR + PostC)], whereas glimepiride had no effect. Cyclosporine preserved EF after IR injury in the resistance vessels [ACh AUC (×10(4)) 1.4 ± 0.2 post-IR vs. 2.2 ± 0.3 post-IR + cyclosporine; P < 0.05].

CONCLUSION

Protection by PostC against endothelial IR injury in humans depends on K(ATP) channel activation and is mimicked by inhibition of the mPTP at reperfusion.

Adiposity and cardiovascular risk factors in a large contemporary population of pre-pubertal children

AIMS

to examine the associations of several markers of adiposity and a wide range of cardiovascular risk factors and biomarkers in pre-pubertal children.

METHODS AND RESULTS

four measures of adiposity,body mass index (BMI), waist circumference, dual-energy X-ray absorptiometry (DXA)-determined fat mass, and leptin concentration, were available in up to 7589 children aged 8.8-11.7 (9.9 mean) years from the Avon Longitudinal Study of Parents and Children (ALSPAC). Thirteen per cent of boys and 18.8% of girls were overweight, and 5.3% of boys and 5% of girls were obese. Body mass index was highly correlated with waist circumference (r = 0.91), DXA fat mass (r = 0.87), and leptin concentration (r = 0.75), and all had similar associations with cardiovascular risk factors. A 1 kg/m(2) greater BMI was associated with 1.4 mmHg (95% CI 1.25-1.44) higher systolic blood pressure (BP). In 5002 children, a 1 kg/m(2) greater BMI was associated with a 0.05 mmol/L (95% CI 0.036-0.055) higher non-high-density lipoprotein (HDL) cholesterol and 0.03 mmol/L (95% CI -0.034 to -0.025) lower HDL cholesterol. There were also graded associations with apolipoproteins A1 and B, interleukin-6, and C-reactive protein. Comparing children who were obese with those who were normal weight, the odds ratio for hypertension was 10.7 (95% CI 7.2-15.9) for boys and 13.5 (95% CI 9.4-19.5) for girls.

CONCLUSION

in pre-pubertal UK children, overweight/obesity is common and has broadly similar associations with BP, HDL cholesterol, and non-HDL cholesterol to those observed in adults. Future research should evaluate whether effective interventions to maintain healthy weight in childhood could have important benefits for adult cardiovascular risk.

Assessment of atherosclerosis: the role of flow-mediated dilatation

Evidence suggests that endothelial dysfunction is on the causal pathway for both atherogenesis and destabilization of established plaques. In this review, the role of flow-mediated dilatation (FMD) as a non-invasive method to assess endothelial function is discussed. Technical modifications and development of analysis software have significantly improved the variability of the method. Following a strict standardized protocol enables reproducible measurements to be achieved and export of the technique from specialized laboratories to population studies and multicentre settings. Endothelial function assessed by FMD has been shown to be affected by cardiovascular risk factors, to be related to structural arterial disease and to cardiovascular outcome, validating its use for studying the pathophysiology of arterial disease. Numerous studies have also demonstrated that it is responsive to physiological and pharmacological interventions. Flow-mediated dilatation provides unique opportunities in drug development programmes to assess an early rapidly responsive signal of risk or benefit, complementing endpoints of structural arterial disease and cardiovascular outcomes that take much longer and are more expensive.

Inflammatory markers in essential hypertension: potential clinical implications

There is a growing interest focusing on the inflammatory response caused by essential hypertension. Inflammatory mechanisms play an important role in the pathogenesis and progression of cardiovascular disease. Recent studies have shown that tissue expression and plasma concentrations of several inflammatory markers and mediators are associated with increased risk of hypertension. These molecules include C-reactive protein, adhesion molecules, such as vascular cell adhesion molecule-1, intercellular adhesion molecule-1 and chemokines. The evaluation of these markers may influence the specific pharmacologic responses and the clinical outcome of the patients with essential hypertension. Moreover, therapeutic approaches targeted to lower blood pressure and suppress inflammatory response may have additional clinical benefits. However, further randomized studies are required to determine the potential favorable effects of suppression of inflammation in the management of arterial hypertension.

Role of NADPH oxidase in endothelial ischemia/reperfusion injury in humans

BACKGROUND

Reactive oxygen species have been implicated in the pathogenesis of ischemia/reperfusion (IR) injury. Recent studies suggest that NADPH oxidase may be a source of ROS during IR. Using an in vivo model of endothelial IR injury in the arm, we compared the response to IR in healthy volunteers with that in patients with chronic granulomatous disease. These patients have a molecular lesion in a subunit of NADPH oxidase that renders the enzyme inactive.

METHODS AND RESULTS

Flow-mediated dilatation was used to assess endothelial function in patients with X-linked (NOX2) or autosomal (p47) chronic granulomatous disease. IR injury was induced by 20 minutes of upper limb ischemia followed by reperfusion. Flow-mediated dilatation was determined before IR and after 20 minutes of reperfusion. The response to IR in chronic granulomatous disease patients was compared with that in age- and sex-matched healthy control subjects. Flow-mediated dilatation was expressed as mean and compared statistically with mixed linear models. IR caused a significant reduction in flow-mediated dilatation in control subjects (-5.1%; 95% confidence interval, 6.3 to 3.%; P<0.001; n=11). IR had no effect on endothelial function in NOX2-chronic granulomatous disease patients (-0.9; 95% confidence interval, -2.1 to 0.3; P=0.12; n=11). Similarly, IR-induced reduction in flow-mediated dilatation was not observed in p47-chronic granulomatous disease patients (-1.5%; 95% confidence interval, -3.1 to 0.2; P=0.08; n=6) in contrast to healthy control subjects (-6.5%; 95% confidence interval, -8.2 to -4.9%; P<0.001; n=6).

CONCLUSIONS

These data indicate, for the first time in humans in vivo, that reactive oxygen species produced by NADPH oxidase are determinants of endothelial function after IR injury in humans. These findings have implications for the design of strategies to limit clinical IR injury.

Determinants of vascular phenotype in a large childhood population: the Avon Longitudinal Study of Parents and Children (ALSPAC)

AIMS

To assess the feasibility and reproducibility of non-invasive vascular assessment in a childhood population setting and identify the determinants of vascular phenotype in early life.

METHODS AND RESULTS

We studied 7557 children (age 9.8-12.3 years) participating in the Avon Longitudinal Study of Parents and Children (ALSPAC). Six research technicians underwent a 5-month training protocol to enable study of brachial artery endothelial function by flow-mediated dilatation (FMD) and arterial stiffness by carotid to radial pulse wave velocity (PWV) and brachial distensibility [distensibility coefficient (DC)]. Reproducibility studies were performed at the beginning, the middle, and the end of the study. A blinded repeat evaluation of a random selection of 3% of the cohort was also undertaken throughout the study. The effect of anthropometric and environmental factors on each measure was examined. Successful measures were obtained in 88, 95, and 87% of the studied children for FMD, PWV, and DC, respectively. The coefficients of variation between technicians for FMD, PWV, and DC were 10.5, 4.6, and 6.6% at the beginning of the study and reached 7.7, 4.1, and 10% at the end. Baseline vessel diameter and gender were important determinants of all the vascular measures, with a small effect of room and skin temperatures on FMD and PWV. Boys consistently had lower FMD and DC and higher PWV measures (P < 0.01 for all).

CONCLUSION

Reproducible, high-quality assessments of vascular structure and function in children can be made on a large scale in field studies by suitably trained non-specialist operators. This study provides an invaluable resource for assessing the impact of early influences, genetic, and environmental factors on arterial phenotype.

Increased arterial stiffness in HIV-infected children: risk factors and antiretroviral therapy

BACKGROUND

Recent evidence suggests that both the HIV virus and antiretroviral therapy (ART) are associated with premature atherosclerosis in adults. Increased arterial stiffness as assessed by pulse wave velocity (PWV) has been associated with adverse cardiovascular outcome in adults. The relationship between HIV infection and treatment and arterial stiffness has not been evaluated in children.

METHODS

We studied 83 HIV-infected children with a mean +/-sd age of 11.0 +/-3.1 years and 59 controls aged 12.2 +/-2.8 years. Among the HIV-infected children, 48 were receiving ART (23 including a protease inhibitor). Arterial stiffness was assessed non-invasively by carotid-radial PWV. Disease severity was defined according to the CDC classification.

RESULTS

PWV was significantly increased in HIV-infected children compared with controls (P<0.05). A significant association between age and PWV was noted in HIV-infected children but not in controls. HIV-infected children receiving ART had significantly increased total cholesterol levels and PWV compared with non-treated children (P<0.001 and P<0.05, respectively). CDC stage was greater in ART-treated compared with non-treated HIV-infected children (P<0.001). No differences in other cardiovascular risk factors were noted in the two groups. After multivariable analysis, ART, systolic blood pressure, disease severity and total cholesterol remained independent predictors of PWV.

CONCLUSIONS

HIV-infected children have increased arterial stiffness compared with healthy children. These changes were more pronounced with increasing age in HIV-infected children particularly in those who were receiving ART.

Combined effects of atorvastatin and metformin on glucose-induced variations of inflammatory process in patients with diabetes mellitus

BACKGROUND

Statin treatment improves survival in patients with atherosclerosis, but their effect on the glucose-induced variations of inflammatory markers, is unknown. We examined the effect of combined therapy with atorvastatin and metformin on glucose-induced variations of inflammatory molecules in patients with newly diagnosed diabetes mellitus type 2 (DM).

METHODS

Thirty five subjects with newly diagnosed DM were randomized to receive metformin 850 mg/d (M, n=17) or metformin 850 mg/d+atorvastatin 10mg (n=18). All subjects underwent glucose loading (75 g oral glucose) at baseline and after 12 weeks of treatment. Blood samples were obtained at baseline and 3h post-loading, while serum tumor necrosis factor alpha (TNF-α) levels were determined at baseline and at 3h.

RESULTS

Serum TNF-α remained unchanged in metformin at baseline (1.36±0.18 to 1.47±0.21 pg/ml p=NS) and after treatment (1.44±0.71 to 1.31±0.17 pg/ml, p=NS), while it was reduced in metformin+atorvastatin (2.3±0.3 to 2.0±0.4 pg/ml, p=NS at baseline and 1.80±0.2 to 1.65±0.2 pg/ml, p=0.03 after treatment).

CONCLUSIONS

Interestingly, the combination of metformin and atorvastatin partly prevents the glucose-loading induced elevation of glucose levels (at 1 h), suggesting a better response to glucose intake than monotherapy with metformin. In addition, combined treatment with atorvastatin and metformin reduces the post-glucose loading levels of TNF-α compared to metformin monotherapy.

The role of flow-mediated dilatation in the evaluation and development of antiatherosclerotic drugs

PURPOSE OF REVIEW

The present article reviews the use of flow-mediated dilatation in clinical cardiovascular research. Its value as a surrogate tool for development of antiatherosclerotic drugs and noninvasive assessment of cardiovascular risk is also discussed.

RECENT FINDINGS

Atherosclerosis remains the leading cause of cardiovascular morbidity and mortality. Development of new drugs is required to target both the evolution of this disease and its clinical consequences. Noninvasive measures of arterial function and structure have been widely used as intermediate phenotypes in clinical trials. Numerous studies have demonstrated the interplay between vascular risk factors and endothelial function as assessed by flow-mediated dilatation in children and adults. Additionally, a number of studies have documented the prognostic value of the method.

SUMMARY

Detection of early arterial changes can prove particularly useful in clinical research for the development of antiatherosclerotic drugs. They permit identification of vascular toxicity as well as characterization of the safety and risk profile of a new cardiovascular treatment modality on vascular health. This approach is likely to prove cost-effective before embarking on large longitudinal studies to assess cardiovascular morbidity and mortality.

Vascular abnormalities, paraoxonase activity, and dysfunctional HDL in primary antiphospholipid syndrome

CONTEXT

Accelerated atherosclerosis has been described in antiphospholipid syndrome, but the vascular abnormalities and the underlying mechanisms remain unclear.

OBJECTIVES

To compare vascular structure and function in patients with positive antiphospholipid antibodies (aPL) with controls and to assess their relationship with paraoxonase activity.

DESIGN, SETTING, AND PARTICIPANTS

A cross-sectional study of 77 women with positive antiphospholipid antibodies from a lupus outpatient clinic in London, England (90% of the eligible population) and 77 controls matched on frequency basis for age and cardiovascular risk factors between June 2006 and April 2009. Carotid intima media thickness (CIMT), flow-mediated dilatation, pulse wave velocity, and paraoxonase activity were measured in all patients. Anti-inflammatory and antioxidant properties of high-density lipoprotein (HDL) were examined.

MAIN OUTCOME MEASURES

CIMT, pulse wave velocity, flow-mediated dilatation, and paraoxonase.

RESULTS

Women with aPL had greater CIMT and pulse wave velocity compared with controls (mean [SD], 0.75 [0.16] vs 0.64 [0.09] mm; 95% confidence interval [CI], -0.14 to -0.06; P < .001; and 9.2 [1.6] vs 8.5 [1.8] m/s; 95% CI, -1.14 to -0.06; P = .04) and lower flow-mediated dilatation (6.2% [4.1%] vs 9.6% [4.2%]; 95% CI, 2.02%-4.69%; P < .001). Paraoxonase activity was lower in women with aPL vs controls (median [interquartile range], 91.2 [64.3-105.1] vs 103.0 [80.5-111.5] micromol p-nitrophenol/L/serum/min; 95% CI, 0.004-0.007; P = .005) and was inversely associated with CIMT and pulse wave velocity in women with aPL (standardized beta coefficient = -0.4 and -0.3, respectively; P < .05 for both), but not in the control group. High-density lipoprotein from women with aPL inhibited endothelial nitric oxide production in human aortic endothelial cells, in contrast with controls. The beneficial effects of HDL from women with aPL on vascular cell adhesion molecule 1 expression, superoxide production, and monocyte adhesion following activation of human aortic endothelial cells were largely blunted.

CONCLUSIONS

Compared with controls, women with aPL had greater functional and structural arterial abnormalities, which were associated with lower activity of paraoxonase. In patients with aPL, HDL reduced nitric oxide bioavailability and had impaired anti-inflammatory and antioxidant properties.

Endothelial response to childhood infection: the role of mannose-binding lectin (MBL)

OBJECTIVE

To assess the influence of mannose-binding lectin (MBL) genotype on endothelial function in the presence and absence of infection in childhood.

METHODS

We studied 2176 children aged 10 years drawn from the Avon Longitudinal Study of Parents and Children. Endothelial function was assessed by flow mediated dilatation (FMD). Exon 1 and promoter polymorphisms in the MBL gene were determined by heteroduplexing procedures. Children were classified as AA (wild type) AO (heterozygotes) and OO (homozygotes).

RESULTS

During the vascular assessment, 544 children presented with current or recent (<2 weeks) infection (INF). FMD was reduced in the INF group compared to controls (10% reduction in FMD, p<0.001). MBL genotype was not associated with FMD in controls, although a relationship with the degree of impairment during INF was observed (8.0%, 7.6% and 26.6% lower FMD compared to controls for groups AA, AO, OO respectively, p<0.05). After multivariate analysis, OO was associated with reduced FMD in the INF group (odds ratio 2.95 [1.33, 6.52], p<0.001).

CONCLUSION

Homozygosity for MBL variant alleles is associated with greater impairment in FMD during infection in childhood. This suggests a gene-environment interaction operating in early life that may have relevance for the initiation and progression of atherosclerosis.

Inflammatory and thrombotic processes are associated with vascular dysfunction in children with familial hypercholesterolemia

BACKGROUND

Evidence suggests that children with familial hypercholesterolemia (FH) have endothelial dysfunction. Inflammatory and haemostatic abnormalities are associated with advanced atherosclerosis and increased cardiovascular events. However, it is unknown whether these abnormalities present in FH children and contribute to their vascular dysfunction.

METHODS AND RESULTS

We studied 38 children with FH (19 males, 19 females aged 14.8+/-0.9 years mean+/-S.E.) and 41 healthy children (controls; 22 males, 19 females aged 15.4+/-0.7 years). Endothelium-dependent reactive hyperemia (RH%) and endothelium-independent nitrate hyperemia dilatation (NH%) were measured by strain gauge plethysmography. Inflammatory and haemostatic parameters were assessed by ELISA. RH% and NH% were significantly reduced in FH compared to controls (91.3+/-9.3% vs. 120.4+/-10.6% and 53.6+/-3.8% vs. 74.5+/-7.4%, p<0.05 for both). Total cholesterol and lipoprotein (a) were increased in FH children compared to controls (282.3+/-8.8 mg/dl vs. 163.8+/-4.6 mg/dl and 11.0[4.6, 30.7]mg/dl vs. 5.24[2.63, 11.0]mg/dl median [IQR] respectively; p<0.001 for both). Intercellular cell adhesion molecule (ICAM-1) and interleukin 1 beta (IL-1 beta) serum levels were increased in FH compared to controls (p<0.05 and <0.001, respectively). Plasminogen activator inhibitor 1 (PAI-1) levels were also higher in FH children (p<0.001). Multivariate analysis revealed that reactive hyperemia was independently associated with nitrate-dependent reactive hyperemia (beta=0.597(0.199), p<0.01), PAI-1(beta=-6.78(2.65), p<0.05), log IL-1 beta (beta=-102.8 (30.2), p<0.01), age (beta=-5.06 (2.35), p<0.05) and FH status (beta=-25.2(10.6), p<0.05) (R(2) for the model: 0.63, p=0.001).

CONCLUSIONS

Inflammatory and haemostatic abnormalities are present in FH children and contribute to the endothelial dysfunction observed in these children.

Methodological approaches to optimize reproducibility and power in clinical studies of flow-mediated dilation

OBJECTIVES

Our aim was to determine reproducibility of the flow-mediated dilation (FMD) response profile, and discriminatory ability of the components.

BACKGROUND

Brachial FMD is widely used to study conduit artery endothelial function. Automated B-mode image edge detection (B-ED) provides a full response profile. Reproducibility and biological relevance of these additional components have not been fully explored.

METHODS

Forty-two healthy adults underwent FMD using B-ED repeated at fixed time intervals up to 3 months. The FMD profile was assessed for diameter changes, area under the curve, and time course. Measures were compared in 25 adults with hypercholesterolemia, 25 subjects with diabetes, and 50 matched control subjects.

RESULTS

The maximum change in FMD was the most reproducible (coefficient of variation = 9.8%, 10.6%, 6.6%, and 9.2% at 4 to 6 h, 1 week, 1 month, and 3 months, respectively). Most of the variability occurred between subjects rather than within. All FMD measures except time course were significantly reduced in hypercholesterolemia and diabetes. Power curves were generated to indicate the appropriate number of subjects for parallel and crossover study designs.

CONCLUSIONS

Maximum FMD percentage change from baseline is the most reproducible of the response curve measures and best identifies those with risk factors. Flow-mediated dilation measured by B-ED is robust and practical to assess the effect of interventions on endothelial function in clinical trials.

Childhood origins of arterial disease

PURPOSE OF REVIEW

The present article reviews the importance of classical and novel risk factors that present in childhood, track into adult life and contribute to arterial disease. The value of noninvasive techniques that can assist in characterization of preclinical atherosclerotic changes as intermediate phenotypes is also discussed.

RECENT FINDINGS

Noninvasive functional and structural techniques are now available and provide the opportunity to characterize early arterial disease long before cardiovascular complications present. By using these techniques, it has been possible to quantify the impact of conventional and novel cardiovascular risk factors seen in childhood on the development of preclinical atherosclerotic changes. Scientific interest has recently widened to include not only study of mechanisms and biomarkers of injury but also mechanisms that promote vascular repair. In this new field, characterization of endothelial progenitor cells has presented new opportunities for cardiovascular research.

SUMMARY

Atherosclerosis begins in early life. Primary prevention strategies for adult cardiovascular disease beginning in childhood have great potential as the disease process is most reversible at this stage. Several guidelines have recently been published for screening and implementation of appropriate therapeutic choices in early life.

Double-blind, randomized, placebo-controlled study of a lotion containing triethyl citrate and ethyl linoleate in the treatment of acne vulgaris

BACKGROUND

Acne vulgaris is a major clinical problem; despite a vast array of treatment modalities available for acne, there is considerable dissatisfaction in acne treatment among patients and doctors. Rising antibiotic drug resistance consequent to the widespread use of topical antibiotics is causing concern and effective nonantibiotic treatments are needed.

OBJECTIVES

To evaluate the efficacy and tolerability of a novel lotion containing triethyl citrate and ethyl linoleate in the treatment of mild to moderate acne vulgaris.

METHODS

This was a double-blind, placebo-controlled, randomized study comparing the active lotion containing triethyl citrate and ethyl linoleate with its vehicle as a placebo control. Patients were assessed by the modified Leeds acne grading system as well as by counting inflammatory and noninflammatory lesions on the face at weeks 0, 4, 8 and 12. Sebum production was assessed by the Sebutape method at weeks 0 and 12. All adverse events were recorded.

RESULTS

Forty patients were recruited into the study, of whom 33 completed the study. Active treatment was statistically superior to placebo in reduction of Leeds grading and total, inflammatory and noninflammatory lesion counts. The active lotion showed a rapid response with obvious reduction in lesion counts and acne grading by 4 weeks. Sebum production was significantly reduced in the actively treated group, with a mean reduction of 53% in sebum production compared with baseline. One patient developed irritation to the active lotion and withdrew from the study.

CONCLUSIONS

The new lotion containing triethyl citrate and ethyl linoleate has been shown to be an effective treatment for mild to moderate acne, with an effect on both inflammatory and noninflammatory acne lesions. The new lotion worked quickly and was generally well tolerated. A surprising finding was the significant impact the new lotion has on sebum production, suggesting a role in patients with seborrhoea. This nonantibiotic preparation will be a very useful addition to existing treatments for acne.

Differences in inflammatory and thrombotic markers between unstable angina and acute myocardial infarction

BACKGROUND

Unstable coronary syndromes are characterised by increased inflammatory process and endothelial activation. However, the underlying mechanisms of the acute coronary syndromes are still obscure. We evaluated the differences of inflammatory and thrombotic markers, at the acute phase of unstable angina (UA) and acute myocardial infarction (AMI).

METHODS

The population of the study consisted of 216 subjects: 136 patients with UA, 57 patients with AMI and 23 healthy controls. Blood samples were taken by their admission to the hospital. Inflammatory and thrombotic markers were measured by ELISA.

RESULTS

Patients with UA had significantly higher levels of interleukin-6 (IL-6), soluble vascular cells adhesion molecule (sVCAM-1) and von Willebrand factor (vWF) (p<0.05 vs controls), and lower levels of antithrombin III (ATIII) (p<0.01 vs controls) and protein C (PrtC) (p<0.05 vs controls). Similarly, patients with AMI had higher levels of IL-6, sVCAM-1, vWF and tissue plasminogen activator (tPA) (p<0.01 vs controls) and lower levels of ATIII (p<0.01 vs controls) and prtC (p<005 vs controls). Patients with AMI had significantly higher levels of vWF, tPA and sVCAM-1 compared to UA patients (p<0.05).

CONCLUSIONS

Patients with unstable coronary syndromes had increased levels of IL-6, sVCAM-1 and vWF as well as decreased levels of ATIII and PrtC by their admission. However, patients with AMI had higher levels of all the endothelium-derived inflammatory (e.g. sVCAM-1) of thrombotic/fibrinolytic (e.g. tPA and vWF) markers, compared to those with UA. These findings imply that patients with myocardial infarction show further increase of endothelium-derived inflammatory and thrombotic markers compared to patients with unstable angina, in response to a similar proinflammatory stimuli.

Statins in heart failure. Beyond the lipid lowering effect

Statins, the most widely prescribed medications in patients with hyperlipidemia and coronary heart disease, have a number of pleiotropic actions beyond cholesterol lowering. They improve endothelial function, they have antioxidant and anti-inflammatory effects, they regulate neovascularization and have immunomodulatory activities. Experimental evidence suggests that statins may be beneficial in heart failure as they can inhibit myocardial hypertrophy, reduce cardiomyocyte loss by apoptosis, reduce oxidative stress and restore neurohormonal imbalance. Furthermore small randomised clinical trials showed that short term statin administration may improve key pathophysiological aspects of this syndrome. Finally retrospective analyses of large statin trials imply a long term profit on clinical outcome in this group of patients. These results however need to be reviewed with caution as certain studies have demonstrated that low serum cholesterol is associated with worse prognosis in HF and that ubiquinone levels, a micronutrient with antioxidant actions, reduces significantly following statin administration. Large prospective randomised controlled trials are needed to confirm the beneficial effect of statins on cardiovascular outcome in HF patients and further elucidate the contributing mechanisms. Finally the statin dose and the interaction with co-administered drugs need to be studied.

Non-Invasive Assessment of Endothelial Function

OBJECTIVES

The purpose of this study was to compare 3 non-invasive techniques for assessment of endothelial function in adults and children and evaluate their utility in acute inflammation.

BACKGROUND

Endothelial dysfunction is a key early event in pre-clinical atherosclerosis. Flow-mediated dilation (FMD), although the established technique, is expensive and technically demanding. Measurements of vascular responses to inhaled salbutamol by pulse wave analysis (PWA) or pulse contour analysis (PCA) are potential alternatives.

METHODS

Sixteen adults (mean age 28 years, range 18 to 39) and 16 children (mean age 13 years, range 7 to 17) underwent concurrent vascular function testing on 2 occasions with ultrasound, PWA, and PCA. Eighteen men were also studied before and after typhoid vaccination.

RESULTS

Reproducibility of FMD was high in adults and children (coefficient of variation [CV] = 7.1 and 6.3, respectively). Salbutamol responses were more variable with PWA (adults CV = 11.5, children CV = 17.1) and PCA particularly in children (adults CV = 18.2, children CV = 36.3). Flow-mediated dilation (p < 0.001) and PWA with salbutamol (p = 0.03) responses fell after typhoid vaccination, and PCA (p = 0.7) was unchanged.

CONCLUSIONS

Vascular dysfunction during acute inflammation can be measured by FMD and by PWA with salbutamol. Flow-mediated dilation is less variable than PWA. Variability of PCA makes this technique currently unsuited to serial measures of endothelial function in children. Flow-mediated dilation remains the most reproducible method.

Calcipotriol/betamethasone dipropionate for the treatment of psoriasis

The two-compound product calcipotriol/betamethasone dipropionate is arising as a first-line treatment for mild-to-moderate plaque psoriasis. Its beneficial action is attributed to the synergistic effect of its components on keratinocyte proliferation and differentiation, and on inflammation. The good tolerability of the two-compound product is thought to be due to the anti-inflammatory effect of betamethasone. Evidence from short-term (4-12 weeks) and long-term use (> 1 year) has shown a good safety profile. Areas such as the face or skin folds, which are sensitive to the components of the combination, should be avoided. Finally, it is unsuitable for use in unstable psoriasis, in which potent steroids may lead to an increased inflammatory response.

Early atherosclerosis in childhood: Diagnostic approaches and therapeutic strategies

The long preclinical phase of atherosclerosis involves the interaction of genetic and environmental factors that modulate the progression of disease from early life. Injury to the endothelium is a critical step in atherosclerotic process. Conventional and novel risk factors for coronary artery disease operate from early in life. Noninvasive methods, using mostly ultrasound techniques, have enabled the assessment of early functional and structural arterial disease progression even from the first decade of life. These measures have been shown to be good surrogate markers for atherosclerotic disease progression and future clinical cardiovascular events. Lifestyle and dietary modifications as well as pharmacological interventions have beneficial effects in prevention and restoration of the early arterial changes.

Endothelial function and inflammation in coronary artery disease

Evidence supports the central role of endothelium and inflammation in all phases of the atherosclerotic process. Clinical studies have shown their prognostic potential for the development of ischaemic events and for adverse outcome after acute coronary syndromes. Reduction in inflammatory levels and improving endothelial function by traditional and novel treatment strategies were associated with a proportional reduction in cardiovascular events. However, randomised controlled trials are required to explore further whether drugs targeting the inflammatory process and endothelial function will constitute a reasonable adjunctive treatment for patients with coronary artery disease.

Early structural and functional changes of the vasculature in HIV-infected children: impact of disease and antiretroviral therapy

BACKGROUND

Premature cardiovascular disease is increasingly recognized in HIV-infected patients, but the mechanisms involved are unclear. The purpose of this study was to determine the impact of HIV infection and antiretroviral therapy (ART) on markers of early vascular disease in children.

METHODS AND RESULTS

We studied 83 HIV-infected children (56 had taken ART, of whom 31 received a regimen containing protease inhibitors [PIs]; 27 were never treated) and a control group of 59 healthy children. Carotid intima-media thickness (IMT) and brachial artery flow-mediated dilatation (FMD) were measured. IMT was significantly greater in HIV-infected children compared with the control subjects (P<0.001). Among the HIV-infected children, age and treatment were significantly associated with increased IMT. Children exposed to PIs had greater IMT compared with both non-PI-treated children and untreated children (P=0.02). FMD was also significantly reduced in the HIV-infected children compared with control subjects (P=0.02). Pairwise comparisons of different treatment exposure groups revealed that FMD was impaired by a mean of 3.6% (95% CI, 1.8 to 5.3; P<0.001) for children exposed to PIs compared with untreated children and by a mean of 1.8% (95% CI, 0.01 to 3.5; P=0.05) compared with non-PI-treated children. HIV-infected children had lipid abnormalities, but they did not account for the observed differences in either FMD or IMT.

CONCLUSIONS

HIV infection in childhood is associated with adverse structural and functional vascular changes that are most pronounced in children exposed to PI therapy. Longitudinal studies are required to differentiate the relative impact of HIV disease and ART and to assess the potential for prevention.

Endothelial Dysfunction in Childhood Infection

Background— Atherosclerosis begins in early life, and endothelial dysfunction is recognized as a key initiating event in the development of atherosclerosis. Although infection has been implicated in endothelial dysfunction and atherogenesis, the impact of acute common childhood infections on the vascular endothelium is unknown.

Methods and Results— We studied 600 children aged 10 years drawn from the Avon Longitudinal Study of Parents and Children. The children were divided into 3 groups: those with current acute infection (AI; n=135; 73 boys and 62 girls); a convalescent group with infection in the past 2 weeks (n=166; 78 boys and 88 girls), and a healthy control group (n=299; 131 boys and 168 girls). Endothelial function was determined in all subjects by high-resolution ultrasound to measure brachial artery flow-mediated dilation (FMD) and was expressed as the percentage change in diameter from baseline after reactive hyperemia. FMD was repeated in 40 children in the AI group and 50 in the control group after a mean interval of 1 year. FMD was lower in both the AI group (6.3±2.7%, mean±SD) and the convalescent group (8.1±3.1%) than in the control group (9.7±2.5%; P <0.001 for both). The observed differences in FMD remained after adjustment for potential confounding variables. At the repeat visit, FMD was unchanged in controls ( P =0.85) but improved in the AI group ( P <0.001).

Conclusions— Acute infection in childhood is associated with impaired endothelium-dependent vasodilation. These findings support a potential role for previously unsuspected extrinsic inflammatory stimuli in the pathogenesis of early atherosclerosis.

Inflammation and endothelial dysfunction as therapeutic targets in patients with heart failure

Evidence suggests that vascular endothelium plays key role in the regulation of vascular tone, in the process of inflammation and in the thrombotic mechanisms. Recent studies indicate that it is an important component of the pathophysiological mechanisms of heart failure. Heart failure may induce endothelial dysfunction by different mechanisms, such as reduced synthesis and release of nitric oxide (NO), increased degradation of NO or by increased production of endothelin-1. In addition, endothelial dysfunction has been associated with the progression of heart failure. Alterations in neurotransmitters, hormones and also in physiological stimuli are present in heart failure and affect the vascular endothelium. Treatments with beneficial effects on endothelial dysfunction may also improve prognosis in patients with heart failure.

Phototherapy in the treatment of acne vulgaris: what is its role?

Acne vulgaris is a common dermatosis affecting 80% of the population. To date, different treatments have been used to manage this condition. Antibacterials and retinoids are currently the mainstay of treatment for acne, but their success rate varies. Phototherapy is emerging as an alternative option to treat acne vulgaris. Studies examining the role of different wavelengths and methods of light treatment have shown that phototherapy with visible light, specifically blue light, has a marked effect on inflammatory acne lesions and seems sufficient for the treatment of acne. In addition, the combination of blue-red light radiation seems to be superior to blue light alone, with minimal adverse effects. Photodynamic therapy has also been used, even in nodular and cystic acne, and had excellent therapeutic outcomes, although with significant adverse effects. Recently, low energy pulsed dye laser therapy has been used, and seems to be a promising alternative that would allow the simultaneous treatment of active acne and acne scarring. Further studies are needed to clarify the role of phototherapy as a monotherapy or an adjuvant treatment in the current management of acne vulgaris.

The impact of platelet glycoprotein IIIa and Ia polymorphisms in cardiovascular thrombotic disease

Platelet adhesion and aggregation play key roles in initiating coronary thrombosis and acute coronary syndromes. During the last decade platelet glycoprotein Ia and IIIa polymorphisms have been studied intensely in order to clarify their contribution to the thrombotic process and moreover their role in acute coronary syndromes. Studies examining these polymorphisms have been inconclusive and often controversial. Polymorphisms in the glycoprotein Ia seem to increase the risk for acute coronary events in younger persons and especially in the presence of other risk factors. The correlation of the Leu33Pro allele of platelet glycoprotein IIIa regarding platelet thrombogenicity is strong but it does not seem to alter the thrombotic risk of the general population. In conclusion, further studies need to elucidate their impact and the potential association with acute thrombotic events.