Stylianos Kapiotis

A Proinflammatory State Is Detectable in Obese Children and Is Accompanied by Functional and Morphological Vascular Changes

Background—Obesity is generally accepted as a risk factor for premature atherosclerosis. Subclinical inflammation as quantified by blood levels of C-reactive protein (CRP) contributes to the development and progression of atherosclerosis. We hypothesized that inflammation in obese children is related to functional and early morphological vascular changes. Methods and Results—Blood levels of high sensitivity (hs) CRP, hsIL-6, the soluble intercellular adhesion molecule1 (ICAM-1), vascular cell adhesion molecule (VCAM)-1, and E-selectin were measured in 145 severely obese (body mass index [BMI], 32.2±5.8 kg/m2) and 54 lean (BMI, 18.9±3.2 kg/m2) children 12±4 years old. Flow-mediated dilation (FMD) of the brachial artery and carotid intima-media thickness (IMT) measured by high-resolution ultrasound as markers of early vascular changes were assessed in 92 (77 obese and 15 lean) and 59 (50 obese and 9 lean) children, respectively. Obese children had significantly higher levels of hsCRP, hsIL-6, and E-selectin than healthy controls (4.1±4.8 versus 0.9±1.5 mg/L, P<0.001 for hsCRP; 1.99±1.30 versus 1.42±1.01 pg/mL, P=0.05 for hsIL-6; and 78±38 versus 59±29 ng/mL, P=0.01 for E-selectin). There were no differences in the levels of ICAM-1 and VCAM-1 between groups. Obese children had lower peak FMD response (7.70±6.14 versus 11.06±3.07%, P=0.006) and increased IMT (0.37±0.04 versus 0.34±0.03 mm, P=0.03) compared with controls. Morbidly obese children (n=14, BMI 44.1±3.9 kg/m2) had highest levels of hsCRP (8.7±0.7 mg/L), hsIL-6 (3.32±1.1 pg/mL), and E-selectin (83±40 ng/mL). Conclusions—A proinflammatory state is detectable in obese children, which is accompanied by impaired vascular endothelial function and early structural changes of arteries, even in young subjects at risk. It remains to be determined whether high hsCRP in obese children predicts cardiovascular events.

Morning Hypercoagulability and Hypofibrinolysis Diurnal Variations in Circulating Activated Factor VII, Prothrombin Fragment F1+2, and Plasmin–Plasmin Inhibitor Complex

BACKGROUND Diurnal fluctuations of blood coagulation and fibrinolysis activity are thought to play a role in the observed circadian variation in the frequency of onset of acute cardiovascular events. In the present study, the diurnal variations in blood coagulation and fibrinolysis activity were investigated in 10 young, healthy control subjects by use of specific molecular activation markers. METHODS AND RESULTS The plasma levels of activated factor FVII (FVIIa), the active portion of the main coagulation activator, decreased during the day (8 AM: 2.03 ng/mL, CI 1.16 to 2.88 ng/mL; 8 PM: 1.16 ng/mL, CI 0.81 to 1.5 ng/mL; P = .005), whereas FVII antigen did not change significantly. In parallel with the diurnal variations of FVIIa, we found a decrease of prothrombin fragment F1+2 (8 AM: 0.97 nmol/L, CI 0.79 to 1.15 nmol/L; 8 PM: 0.78 nmol/L, CI 0.64 to 0.93 nmol/L; P = .005), a molecular marker of intravasal thrombin generation. Evidence for a possible functional relevance of circulating FVIIa was found because this parameter was significantly correlated with prothrombin fragment F1+2 in 72 fasting healthy individuals (r = .29, P = .011). Plasminogen activator inhibitor-1 levels decreased (8 AM: 9.9 ng/mL, CI 7.7 to 12.1 ng/mL; 8 PM: 5.4 ng/mL, CI 3.8 to 6.9 ng/mL; P < .005), whereas plasmin-plasmin inhibitor complex levels, representing the degree of intravascular plasmin generation, concomitantly increased (8 AM: 235 micrograms/L, CI 198 to 272 micrograms/L; 8 PM: 449 micrograms/L, CI 391 to 507 micrograms/L; P = .008). CONCLUSIONS Our data suggest that the diurnal changes in the plasma levels of activators and inhibitors of coagulation and fibrinolysis lead to corresponding changes in the activity state of these systems, leading to morning hypercoagulability and hypofibrinolysis.

Clinical significance of lupus anticoagulants in children

OBJECTIVES To determine the spectrum of associated clinical manifestations and time course of lupus anticoagulants (LA) in children. STUDY DESIGN Retrospective study of 95 consecutive children (46 boys and 47 girls), with a median age of 5.3 years (range, 1.7 to 17.1 years), diagnosed with presence of LA at a hemostasis referral center; 83 were followed up over a median of 2.9 years (range, 6 weeks to 21.6 years). RESULTS At diagnosis, 80 of 95 (84%) children were free of symptoms, and presence of LA was found incidentally. Nine children (10%) had bleeding symptoms, 5 (5%) had thrombotic events, and 1 had systemic lupus erythematosus. Among the patients with bleeding, 5 had transient severe hypoprothrombinemia after adenovirus infections, and 3 had thrombocytopenia. None of the children who were initially free of symptoms had bleeding, thrombotic complications, or autoimmune disease subsequently. At follow-up, 48 of 83 (58%) patients had normal activated partial thromboplastin time values after 1.9 years (5 weeks to 19.1 years). Thirty-two (38%) still had activated partial thromboplastin time elevations but did not fulfill all criteria for presence of LA after 3.2 years (7.4 months to 9.3 years). Three (4%) patients, who had presented with thrombosis, had persistent positive LA, anti-cardiolipin, and antinuclear antibodies after 1.4, 2.8, and 7.5 years, respectively. One of these had recurrent thrombosis. CONCLUSIONS In most children the presence of LA did not lead to clinical complications and was transient. Bleeding occurred with additional hypoprothrombinemia or thrombocytopenia. Thrombosis was rare and strongly associated with persistently positive LA.

Menstrual cycle-associated changes in blood levels of interleukin-6, α1 acid glycoprotein, and C-reactive protein☆

Based on previous studies we hypothesized that interleukin-6 (IL-6) plasma levels would increase during the menstrual cycle, in analogy to the increase in IL-1 levels seen during the luteal phase. Thus we have investigated menstrual cycle-associated changes in IL-6, alpha1 acid glycoprotein (AGP), and C-reactive protein (CRP). The study design was cross-sectional and was conducted in 18 healthy premenopausal women with regular menstrual cycles and in 15 age-matched men. The women had blood drawings in the follicular phase, at midcycle, and in the luteal phase of the menstrual cycle. A single blood sample was obtained from men to compare IL-6 levels between sexes. The median IL-6 level was 0.68 pg/ml (95% confidence interval (CI): 0.60 to 1.05) in the follicular phase and did not change significantly during the menstrual cycle. IL-6 levels did not differ between women and men (0.79 pg/ml; CI: 0.66 to 1.05; p > 0.05). Median AGP levels decreased by 6% (CI: -14% to 1%) during the luteal phase (p = 0.005), and a significant correlation between mean AGP and IL-6 levels was found (r = 0.60; p = 0.01). Median CRP levels increased by 44% (CI: 27% to 59%; p < 0.001) at midcycle and by 31% (CI: 17% to 68%; p = 0.002) in the luteal phase, and there was a significant correlation between the relative increase in CRP at midcycle and the relative increase in progesterone levels during midcycle (r = 0.60; p = 0.01) and the luteal phase (r = 0.71; p = 0.001). In conclusion, we found no sustained menstrual cycle-dependent changes in systemic IL-6 plasma levels. AGP and CRP levels may be differentially regulated during the menstrual cycle of healthy women: AGP levels correlated with IL-6 levels, and AGP levels decreased during the menstrual cycle, whereas CRP levels increased during the menstrual cycle and correlated with the increase in progesterone levels. The reason for the observed changes in CRP levels remains to be elucidated.

The adipokine visfatin is markedly elevated in obese children.

Objective: The insulin-mimetic adipocytokine visfatin has been linked to adiposity and the metabolic syndrome. Design Cross-sectional study. Subjects: Eighty-three nondiabetic obese children and 40 healthy controls. Measurements: We analyzed plasma visfatin concentrations to assess whether this adipokine is associated with adiposity. Results: Plasma visfatin concentrations were nearly 2-fold higher in obese children (mean, 1.1 ng/mL; 95% CI, 0.2-6.6) than in controls (0.6 ng/mL, 95% CI, 0.6 to 0.6; P < 0.001). No relationship was detectable between visfatin and other subject characteristics, hsCRP or the lipid profile. Conclusions: Visfatin may be involved in the development of metabolic derangements in obese children.

Hydrogen sulphide: A novel physiological inhibitor of LDL atherogenic modification by HOCl

Hypochlorite (HOCl), the product of the activated myeloperoxidase/H2O2/chloride (MPO/H2O2/Cl− ) system is favored as a trigger of LDL modifications, which may play a pivotal role in early atherogenesis. As HOCl has been shown to react with thiol-containing compounds like glutathione and N-acetylcysteine protecting LDL from HOCl modification, we have tested the ability of hydrogen sulfide (H2S)—which has recently been identified as an endogenous vasorelaxant—to counteract the action of HOCl on LDL. The results show that H2S could inhibit the atherogenic modification of LDL induced by HOCl, as measured by apolipoprotein alterations. Beside its HOCl scavenging potential, H2S was found to inhibit MPO (one may speculate that this occurs via H2S/heme interaction) and destroy H2O2. Thus, H2S may interfere with the reactants and reaction products of the activated MPO/H2O2/Cl− system. Our data add to the evidence of an anti-atherosclerotic action of this gasotransmitter taking the role of HOCl in the atherogenic modification of LDL into account.

Effect of hydroxyethyl starch on the activity of blood coagulation and fibrinolysis in healthy volunteers : comparison with albumin

ObjectiveThe aim of this study was to investigate whether hydroxyethyl starch of medium molecular weight (200 daltons), compared with albumin, has specific effects on blood coagulation and fibrinolysis. DesignA prospective, randomized, double-blind, crossover trial. SettingLaboratory at a university hospital. PatientsTen healthy male volunteers, 23 to 39 yrs old, with no history of hypersensitivity, who had normal physical examinations, and were free of a bleeding disorder. All patients did not ingest any medications for ≥2 wks before or during the study period.Intervention: Each volunteer received either 500 mL of hydroxyethyl starch (6% wt/vol, average molecular weight 200 kilodaltons, molar substitution 0.5 [ratio hydroxyethyl groups/glucose units] in 0.9% sodium chloride; average molecular weight of 200 kilodaltons) or a control of 500 mL of human albumin (5% albumin solution). After a washout period of 4 wks, subjects crossed over to the alternate treatment. Measurements and Main ResultsBlood samples were taken immediately before infusion and 20, 45, 75, 105, 165, 285, 405, and 1485 mins after the infusion started. Hematocrit, the blood coagulation parameters fibrinogen, activated partial thromboplastin time, factor VIII:C, thrombin-antithrombin III complexes, and the fibrinolytic parameters fibrin-split product D-Dimer, tissue type plasminogen activator, urokinase plasminogen activator, plasminogen activator inhibitor, and plasmin-antiplasmin complexes were measured. Except for factor VIII:C levels, which were significantly lower in the hydroxyethyl starch group, no other significant differences in the plasma levels of the parameters mentioned were detected between hydroxyethyl starch and albumin infusions. In one volunteer, who had a low initial factor VIII:C level of 51%, a decrease to 28% at 165 mins during hydroxyethyl starch infusion was found (corresponding albumin value at 165 mins was 41%). Conclusionsa) Medium molecular weight hydroxyethyl starch has a specific lowering effect on factor VIII:C concentrations; this phenomenon may be hazardous to patients who need full hemostatic competence and who receive medium molecular weight hydroxyethyl starch (e.g., as a plasma expander), b) Medium molecular weight hydroxyethyl starch does not specifically influence the activity of the fibrinolytic system. (Crit Care Med 1994; 22:606–612)

The novel gaseous vasorelaxant hydrogen sulfide inhibits angiotensin-converting enzyme activity of endothelial cells

Objective Beside NO (nitric monoxide) and CO (carbon monoxide), H2S (hydrogen sulfide) has been identified recently as the third gasotransmitter. By acting directly on KATP-channels on smooth muscle cells (SMC) H2S possesses vasorelaxing properties. It has the potential to react with metal ions (i.e. Cu, Fe, Zn) in metalloproteins. Angiotensin-converting enzyme (ACE), responsible for vasoconstriction, is a zinc (Zn2+) containing enzyme. We therefore hypothesized that H2S may interact with the Zn2+ in the active center of ACE, modulating (inhibiting) enzyme activity. Methods ACE activity was measured on the surface of human endothelial cells (HUVECs) monolayers in culture, ex-vivo in umbilical veins and in HUVEC protein extracts. Quantitative real-time polymerase chain reaction (PCR) was used to study the effect of H2S on ACE mRNA expression in HUVECs. Results H2S inhibited the activity of ACE in HUVEC protein extracts in a dose-dependent manner, and only Zn2+ but not Cd2+, Ca2+ or Mg2+ could counteract the inhibitory effect. Cell-surface ACE activity was inhibited by H2S on HUVEC monolayers and in ex-vivo umbilical veins. No influence of H2S on ACE mRNA expression was observed. Conclusion H2S exhibits direct inhibitory action on ACE activity in HUVECs, obviously by interfering with the Zn2+ in the active center of the enzyme. Thus, beside the known influence of H2S on SMC KATP-channels, the observed direct ACE inhibitory effect may add to the vasorelaxant effect of H2S in the vasculature by reducing angiotensin II production and inhibiting bradykinin degradation.

Effects of desmopressin on circulating P-selectin.

Von Willebrand factor (VWF) and P‐selectin share an identical intracellular storage compartment and transport to the cell surface. We induced degranulation of the Weibel‐Palade bodies and measured circulating (c)P‐selectin in plasma to test whether soluble P‐selectin is present in the Weibel‐Palade bodies, or if P‐selectin bound to the cell membrane of endothelial cells (EC) is rapidly proteolytically cleaved in vivo.  A dose of 0.3 μg/kg of desmopressin (DDAVP) or placebo was infused over 30 min to eight healthy men in a double‐blind cross‐over study. Plasma levels of cP‐selectin and VWF‐Ag were followed for 24 h. Despite a twofold increase in VWF‐Ag levels immediately after and 2 h after infusion of DDAVP, no significant change in plasma concentrations of cP‐selectin were observed.  In summary, degranulation of the Weibel‐Palade bodies is an unlikely source of cP‐selectin. Thus cP‐selectin in healthy subjects is conceivably attributable to other mechanisms, such as minor degrees of platelet activation or transcription induction of an alternatively spliced P‐selectin.

Acetaminophen has greater antipyretic efficacy than aspirin in endotoxemia: a randomized, double-blind, placebo-controlled trial.

To compare the antipyretic efficacy of aspirin and acetaminophen (INN, paracetamol) in 30 male volunteers with the use of endotoxin (lipopolysaccharide) to elicit a standardized febrile response.