Andrzej Surdacki

Reduced urinary excretion of nitric oxide metabolites and increased plasma levels of asymmetric dimethylarginine in men with essential hypertension

Our aim was to investigate systemic nitric oxide (NO) production and its potential determinants such as insulin resistance, dyslipidemia, and circulating methylated analogs of L-arginine in uncomplicated essential hypertension (EH). Nineteen newly diagnosed, untreated male subjects with mild pure uncomplicated EH and 11 normotensive controls were studied at rest after an overnight fast. The groups had comparable age, body mass index, creatinine clearance, cholesterol, fasting glucose, and insulin. In hypertensives, the urinary excretion rate of nitrite plus nitrate (Unox), an index of endogenous NO production, was depressed (56+/-17 vs. 77+/-23 micromol/mmol creatinine; p < 0.05), whereas plasma levels of asymmetric dimethylarginine (ADMA), an endogenous inhibitor of NO synthesis, were increased (2.4+/-1.1 vs. 1.1+/-0.7 microM; p < 0.005). Circulating concentrations of symmetric dimethylarginine were similar in both groups (1.4+/-1.3 vs. 1.5+/-1.1 microM; p = NS). The L-arginine-to-ADMA ratio was reduced in hypertension (3.3+/-0.5 vs. 4.5+/-0.8; p < 0.001 for In-transformed data). There was no correlation between Unox and either the magnitude of insulin resistance or dyslipidemia in EH. Thus in male subjects with EH, endogenous systemic NO formation appears depressed, which is unrelated to accompanying insulin resistance or dyslipidemia. Circulating ADMA levels are increased in uncomplicated EH, which may be of potential relevance.

Oral l-arginine improves endothelial function in healthy individuals older than 70 years

Ageing is associated with progressive endothelial dysfunction in normal humans. Flow-mediated dilation (FMD) of the brachial artery is impaired in elderly individuals with cardiovascular disease and vascular nitric oxide (NO) bioavailability is reduced. We investigated whether oral L-arginine, the substrate for NO synthesis, can improve impaired FMD in healthy very old people. In a prospective, double-blind, randomized crossover trial, 12 healthy old subjects (age 73.8 6 2.7 years) took L-arginine (8 g p.o. two times daily) or placebo for 14 days each, separated by a wash-out period of 14 days. FMD was determined by high-resolution ultrasound in the brachial artery during reactive hyperaemia. Baseline artery diameter was 3.88 6 0.18 mm. l-Arginine signifi cantly improved FMD (to 5.7 6 1.2%, p, 0.0001), whereas placebo had no effect (-0.25 6 0.7%; n.s.). After L-arginine, plasma levels of L-arginine increased signifi cantly (114.9 6 11.6 versus 57.4 6 5.0 mmol/l), but placebo had no effect. As NO synthesis can be antagonized by its endogenous inhibitor asymmetric dimethyl L-arginine (ADMA), we determined ADMA plasma concentrations, which were elevated at baseline in comparison to healthy middle-aged individuals (3.9 6 0.2 versus 1.0 6 0.1 mmol/l; p, 0.0001). ADMA remained unchanged during treatment, but L-arginine supplementation normalized the L-arginine/ADMA ratio (p, 0.05). We conclude that in healthy very old age endothelial function is impaired and may be improved by oral L-arginine supplementation, probably due to normalization of the L-arginine/ADMA ratio.

Divergence in urinary 8-iso-PGF2α (iPF2α-III, 15-F2t-IsoP) levels from gas chromatography–tandem mass spectrometry quantification after thin-layer chromatography and immunoaffinity column chromatography reveals heterogeneity of 8-iso-PGF2α: Possible methodological, mechanistic and clinical implications

Abstract Free radical-catalysed oxidation of arachidonic acid esterified to lipids leads to the formation of the F2-isoprostane family which may theoretically comprise up to 64 isomers. We have previously shown that the combination of TLC and GC–tandem MS (referred to as method A) allows for the accurate and highly specific quantification of 8-iso-PGF2α (iPF2α-III, 15-F2t-IsoP) in human urine. Immunoaffinity column chromatography (IAC) with immobilized antibodies raised against 8-iso-PGF2α (i.e. 15(S)-8-iso-PGF2α) has been shown by others to be highly selective and specific for this 8-iso-PGF2α isomer when quantified by GC–MS. In the present study we established IAC for urinary 8-iso-PGF2α for subsequent quantification by GC–tandem MS (referred to as method B). This method was fully validated and found to be highly accurate and precise for urinary 15(S)-8-iso-PGF2α. 8-iso-PGF2α was measured in urine of 10 young healthy humans by both methods. 8-iso-PGF2α was determined to be 291±102 pg/mg creatinine by method A and 141±41 pg/mg creatinine by method B. Analysis of the combined through and wash phases of the IAC step, i.e. of the unretained compounds, by method A showed the presence of non-immunoreactive 8-iso-PGF2α at 128±55 pg/mg creatinine. This finding suggests that urinary 8-iso-PGF2α is heterogenous, with 15(S)-8-iso-PGF2α contributing by ∼50%. PGF2α and other 8-iso-PGF2α isomers including 15(R)-8-iso-PGF2α are not IAC-immunoreactive and are chromatographically separated from 15(S)-8-iso-PGF2α. We assume that ent-15(S)-8-iso-PGF2α is also contributing by ∼50% to urinary 8-iso-PGF2α. This finding may have methodological, mechanistic and clinical implications.

Differential associations of inflammatory and endothelial biomarkers with disease activity in rheumatoid arthritis of short duration.

Objectives. To estimate endothelial dysfunction in patients with rheumatoid arthritis (RA) of short duration in relation to disease activity based on the assessment of 28 joints (DAS28). Methods. We studied 29 patients (22 women, mean age 41 (SD, 9) years) with RA of short duration and 29 healthy controls. The RA subjects were divided into those with low (DAS28: 2.6–5.1, n = 18) or high (DAS28 > 5.1, n = 11) disease activity. Exclusion criteria included clinically overt atherosclerosis and other coexistent diseases. Biochemical markers of inflammatory activation and endothelial dysfunction were measured. Results. There were no significant intergroup differences in the majority of classical cardiovascular risk factors. High-sensitivity C-reactive protein, tumor necrosis factor-α, and interleukin-6 were increased in RA subjects. Compared to the controls, levels of soluble vascular cell adhesion molecule-1, von Willebrand factor, and pentraxin-3 were significantly elevated in RA subjects with low disease activity, exhibiting no further significant rises in those with high disease activity. Asymmetric dimethyl-L-arginine, soluble E-selectin, monocyte chemotactic protein-1, and osteoprotegerin were increased only in RA patients with high disease activity. Conclusions. Our findings might suggest a dissociation of pathways governing generalized and joint-specific inflammatory reactions from those involved in endothelial activation and inflammation within the vascular wall.

Plasma asymmetric dimethylarginine is related to anticitrullinated protein antibodies in rheumatoid arthritis of short duration

We have recently demonstrated elevated plasma levels of an endogenous nitric oxide synthase inhibitor, asymmetric dimethyl-L-arginine (ADMA), and its association with carotid atherosclerosis in rheumatoid arthritis (RA). Both an elevated risk of myocardial infarction and increased levels of anticitrullinated protein antibodies (ACPAs), specific for RA, had been shown to precede the onset of clinical RA symptoms. Therefore, our aim was to verify the hypothesis that ADMA accumulation might accompany raised ACPAs titers in RA of short duration (< or = 3 years). Twenty patients (16 women, 4 men; mean age, 45 +/- 12 years; mean disease duration, 2.3 +/- 0.5 years) with active RA despite chronic disease-modifying antirheumatic medication, free of cardiovascular disease or atherosclerotic risk factors, were studied. Plasma levels of ADMA and its stereoisomer, symmetric dimethyl-L-arginine (SDMA), were assayed by liquid chromatography/tandem mass spectrometry. The ACPAs were measured by a second-generation enzyme-linked immunosorbent assay. In addition to routine biochemical assays, plasma concentrations of tumor necrosis factor alpha, monocyte chemoattractant protein-1, and vascular cell adhesion molecule-1 soluble form were analyzed with respective enzyme-linked immunosorbent assays. A significant positive correlation between levels of ACPAs and ADMA (r = .60, P = .005), but not SDMA (r = -.02, P = .9), was found. Neither ADMA nor SDMA was correlated to any of the clinical or biochemical parameters reflecting disease activity and inflammatory activation. Thus, excessive ADMA accumulation accompanies elevated ACPAs levels in patients with RA of short duration free of cardiovascular disease or risk factors.

Association of plasma miR-223 and platelet reactivity in patients with coronary artery disease on dual antiplatelet therapy: A preliminary report

Abstract Decreased plasma levels of microRNA-223 (miR-223), predominantly of platelet origin, were proposed as a surrogate marker of efficacy of antiplatelet therapy. However, higher on-treatment platelet reactivity was associated with lower plasma miR-223 in patients with coronary artery disease (CAD) on dual antiplatelet therapy (DAPT) including clopidogrel and aspirin. Our aim was to compare plasma miR-223 and platelet reactivity in CAD patients on DAPT with newer P2Y12 antagonists vs. clopidogrel. We studied 21 men with CAD admitted to our centre owing to a non-ST-elevation acute coronary syndrome, and with an uncomplicated hospital course. From the day of admission, the patients were receiving either clopidogrel (n = 11) or prasugrel/ticagrelor (n = 10) in addition to aspirin. Before discharge, miR-223 expression in plasma was estimated by quantitative polymerase chain reaction using the comparative Ct method relative to miR-16 as an endogenous control. Multiple electrode aggregometry was used to assess platelet aggregation in response to adenosine diphosphate (ADP). ADP-induced platelet reactivity was decreased in the patients treated with prasugrel or ticagrelor compared with those on clopidogrel (mean ± SD: 139 ± 71 vs. 313 ± 162 arbitrary units [AU]*min, p = 0.006), due to a more potent antiplatelet activity of the novel P2Y12 antagonists. Consequently, six out of seven patients in the lower tertile of the ADP-induced platelet aggregation were treated with the newer P2Y12 blockers, whereas six out of seven patients in the upper tertile were on clopidogrel. Plasma miR-223 was elevated with decreasing platelet reactivity (Spearman’s rho = –0.52; p = 0.015 for trend), being significantly higher in the lower tertile of the ADP-induced platelet aggregation (median [range]: 1.06 [0.25–2.31]) vs. the upper tertile (0.20 [0.13–2.30]) (p = 0.04). In conclusion, our preliminary results argue against the notion of low plasma miR-223 as a marker of platelet responsiveness to DAPT. On the contrary, more potent platelet inhibition associated mainly with newer P2Y12 antagonists appears to coincide with higher miR-223 relative to the subjects with attenuated responsiveness to DAPT.

Association between endothelial progenitor cell depletion in blood and mild-to-moderate renal insufficiency in stable angina

BACKGROUND Low blood counts of CD34/kinase-insert domain receptor double-positive cells (CD34(+)/KDR(+) cells)-a leukocytes subpopulation enriched for bone marrow-derived endothelial progenitor cells (EPC)- predict adverse outcomes in coronary artery disease (CAD). The dependence of EPC numbers on the glomerular filtration rate (GFR), another prognostic factor, has not been reported in CAD yet. Our aim was to assess CD34(+)/KDR(+) cell counts versus GFR in stable angina. METHODS We studied 102 stable angina men with severe angiographic CAD and normal left-ventricular systolic function. CD34(+)/KDR(+) cells were enumerated by flow cytometry. RESULTS With lowering GFR, CD34(+)/KDR(+) cell numbers (% of lymphocytes, median and interquartile range) decreased: 0.04 (0.03-0.06), 0.03 (0.02-0.05) and 0.02 (0.01-0.03)% for GFR >or=90, 60-89 and 30-59 ml/min/1.73 m(2), respectively (P < 0.001 for trend). CD34(+)/KDR(+) cell counts correlated with GFR (r = 0.25, P = 0.01), CAD extension score (r = -0.20, P = 0.04), soluble form of vascular cell adhesion molecule-1 (sVCAM-1) (r = -0.22, P = 0.03) and homocysteine (r = -0.20, P = 0.04) levels. A GFR <90 ml/min/1.73 m(2) was associated with insignificantly higher plasma erythropoietin concentrations (r = -0.22, P = 0.09 for trend) that correlated with haemoglobin levels (r = -0.33, P = 0.01, n = 59). The GFR-CD34(+)/KDR(+) cells relation was attenuated, yet maintained (beta = 0.19 +/- 0.09, P = 0.04) on adjustment for the remaining multivariate determinants of CD34(+)/KDR(+) cell numbers: sVCAM-1 (beta = -0.20 +/- 0.09, P = 0.03) and haemoglobin (beta = 0.18 +/- 0.09, P = 0.05). CONCLUSIONS Mild-to-moderate renal dysfunction accompanying stable angina is associated with CD34(+)/KDR(+) cell depletion, which partially depends on concomitant endothelial dysfunction and a tendency to anaemia (despite insignificantly higher erythropoietin) irrespective of an angiographic CAD extent. This may exacerbate an imbalance between endothelial injury and EPC-mediated repair, thus contributing to high cardiovascular risk in CAD coexisting with renal insufficiency.

Elevated markers of inflammation and endothelial activation and increased counts of intermediate monocytes in adult survivors of childhood acute lymphoblastic leukemia

BACKGROUND Adult survivors of childhood malignancy are prone to accelerated atherogenesis and late cardiovascular complications. Plaque formation is initiated by recruitment of monocytes and T-cells into the intima, mediated by adhesion molecules and chemokines expressed by activated endothelial cells. AIM To assess markers of inflammatory activity, endothelial activation as well as monocyte heterogeneity in adult survivors of childhood acute lymphoblastic leukemia (ALL) who had been treated with chemotherapy without cranial irradiation. METHODS AND RESULTS We studied 27 (age: 18-28 years) healthy survivors of childhood ALL and 20 controls (age: 20-31 years). Flow cytometry was used to identify monocyte subsets: classical CD14(++)CD16(-), intermediate CD14(++)CD16(+) and nonclassical CD14(+)CD16(++) monocytes which were further characterized by their expression of HLA-DR and β2-integrins CD11b/CD18 and CD11c/CD18. In ALL survivors we found increased levels of pentraxin-3 (median [interquartile range]: 0.63 [0.36-0.94] vs. 0.40 [0.32-0.57] ng/ml; p = 0.03), soluble vascular cell adhesion molecule-1 (687 [597-761] vs. 558 [534-702]ng/ml; p = 0.02), osteoprotegerin (mean ± SD: 5.24 ± 1.00 vs. 4.42 ± 1.34 pmol/l; p = 0.02) and tumor necrosis factor (TNF)-related apoptosis-inducing ligand (107.0 ± 23.6 vs. 89.5 ± 18.9 pg/ml; p = 0.01), whereas C-reactive protein, interleukin 6 and 18, TNF-α, monocyte chemotactic protein-1 and soluble intercellular adhesion molecule-1 were unchanged. Former ALL patients exhibited elevated counts of intermediate monocytes (6.3 ± 4.0 vs. 4.3 ± 1.5% of blood monocytes; p = 0.03). CD11b/CD18 and CD11c/CD18 expression on intermediate monocytes tended to be higher in ALL survivors (1917 ± 993 vs. 1396 ± 673 MFI [median fluorescence intensity]; p = 0.06 and 3883 ± 1445 vs. 3185 ± 645 MFI; p = 0.05, respectively). CONCLUSION Our findings suggest chronic inflammatory activation and immune dysregulation in adult survivors of childhood ALL, which can translate into late cardiovascular morbidity.

Short- and intermediate-term improvement of patient quality of life after transcatheter aortic valve implantation: a single-centre study

BACKGROUND Transcatheter aortic valve implantation (TAVI) is a treatment option for elderly high-risk patients with symptomatic severe aortic stenosis. Improvement of quality of life (QoL) is a relevant issue in this group of patients. AIM To assess changes in QoL after TAVI. METHODS Forty patients who underwent TAVI in our institution were included in this QoL study. All subjects were screened for TAVI in a standard fashion, including QoL assessment with the EQoL (EQ-5D-3L). The pre- and postprocedural scores obtained up to a 12-month follow-up were assessed. RESULTS Median of logistic EuroScore I was 21.5% (13.5-26.75%), and Society of Thoracic Surgeons score was 5.5% (4.0-10.75%). Comparison of baseline values with follow-up data at one, six and 12 months after TAVI showed significant improvement of QoL (p < 0.001). Visual Analogue Scale score (VAS score) was assessed. There was an incremental increase in VAS score during follow-up (p < 0.001). Median of six-minute walk test distance at baseline was 200 m (IQR 150-300) and 325 m (IQR 250-400) 12 months after TAVI (p < 0.001). CONCLUSIONS TAVI provides improved QoL and effectively relieves symptoms.

Effect of a hemodialysis session on plasma levels of endothelin-1 in hypertensive and normotensive subjects with end-stage renal failure.

Background: Elevated plasma endothelin-1 (ET-1) was found in end-stage renal failure (ESRF). However, there are discordant reports on the influence of hypertension on plasma ET-1 in ESRF and on the effect of hemodialysis on ET-1 concentrations. Aim: To compare the time course of plasma ET-1 during hemodialysis in hypertensive (HT) and normotensive (NT) ESRF patients. Methods: Plasma ET-1 and mean blood pressure (MP) were measured in 12 HT patients and 11 matched NT patients on maintenance hemodialysis at baseline (B), after a 2.5–3.5 h hemodialysis with ultrafiltration (P1) and after a subsequent 1 h isovolumic dialysis (P2). Results: In HT patients, plasma ET-1 increased at P1 with no further change after P2 (B vs. P1 and P2, p < 0.05). In NT patients, ET-1 levels were similar at B, P1 and P2. In HT, but not in NT subjects, volume loss correlated with change of ET-1 at P1. In HT patients, MP fell during P1 and tended to return towards baseline at P2. In NT patients, MP dropped after P1 and remained lower also at P2. Conclusion: Hypertensive ESRF subjects exhibit potentiated ET-1 release on hemodialysis, possibly stimulated by volume depletion with sympathetic activation, which may attenuate hypotensive hemodialysis effects thus contributing to hypertension in ESRF.