Peter Bobbert

Adiponectin expression in patients with inflammatory cardiomyopathy indicates favourable outcome and inflammation control

AIMS Circulating adiponectin (APN) is an immunomodulatory, pro-angiogenic, and anti-apoptotic adipocytokine protecting against acute viral heart disease and preventing pathological remodelling after cardiac injury. The purpose of this study was to describe the regulation and effects of APN in patients with inflammatory cardiomyopathy (DCMi). METHODS AND RESULTS Adiponectin expression and outcome were assessed in 173 patients with DCMi, 30 patients with non-inflammatory DCM, and 30 controls. Mechanistic background of these findings was addressed in murine experimental autoimmune myocarditis (EAM), a model of human DCMi, and further elucidated in vitro. Adiponectin plasma concentrations were significantly higher in DCMi compared with DCM or controls, i.e. 6.8 ± 3.9 µg/mL vs. 5.4 ± 3.6 vs. 4.76 ± 2.5 µg/mL (P< 0.05, respectively) and correlated significantly with cardiac mononuclear infiltrates (CD3+: r(2)= 0.025, P= 0.038; CD45R0+: r(2)= 0.058, P= 0.018). At follow-up, DCMi patients with high APN levels showed significantly increased left ventricular ejection fraction improvement, decreased left ventricular end-diastolic diameter, and reduced cardiac inflammatory infiltrates compared with patients with low APN levels. A multivariate linear regression analysis implicated APN as an independent prognostic factor for inhibition of cardiac inflammation. In accordance with these findings in human DCMi, EAM mice exhibited elevated plasma APN. Adiponectin gene transfer led to significant downregulation of key inflammatory mediators promoting disease. Mechanistically, APN acted as a negative regulator of T cells by reducing antigen specific expansion (P< 0.01) and suppressed TNFα-mediated NFκB activation (P< 0.01) as well as release of reactive oxygen species in cardiomyocytes. CONCLUSION Our results implicate that APN acts as endogenously upregulated anti-inflammatory cytokine confining cardiac inflammation and progression in DCMi.

Increased plasma retinol binding protein 4 levels in patients with inflammatory cardiomyopathy

Chronic heart failure (CHF) is associated with a higher risk for diabetes mellitus. Retinol binding protein 4 (RBP 4) is an adipose tissue‐derived protein with pro‐diabetogenic effects. A complete understanding of the association of CHF and insulin resistance remains elusive. The purpose of this study was to examine the relationship between CHF and diabetes mellitus.

Protease-activated receptor-2 regulates the innate immune response to viral infection in a coxsackievirus B3-induced myocarditis.

OBJECTIVES This study sought to evaluate the role of protease-activated receptor-2 (PAR2) in coxsackievirus B3 (CVB3)-induced myocarditis. BACKGROUND An infection with CVB3 leads to myocarditis. PAR2 modulates the innate immune response. Toll-like receptor-3 (TLR3) is crucial for the innate immune response by inducing the expression of the antiviral cytokine interferon-beta (IFNβ). METHODS To induce myocarditis, wild-type (wt) and PAR2 knockout (ko) mice were infected with 10(5) plaque-forming units CVB3. Mice underwent hemodynamic measurements with a 1.2-F microconductance catheter. Wt and PAR2ko hearts and cardiac cells were analyzed for viral replication and immune response with plaque assay, quantitative polymerase chain reaction, Western blot, and immunohistochemistry. RESULTS Compared with wt mice, PAR2ko mice and cardiomyocytes exhibited a reduced viral load and developed no myocarditis after infection with CVB3. Hearts and cardiac fibroblasts from PAR2ko mice expressed higher basal levels of IFNβ than wt mice did. Treatment with CVB3 and polyinosinic:polycytidylic acid led to higher IFNβ expression in PAR2ko than in wt fibroblasts and reduced virus replication in PAR2ko fibroblasts was abrogated by neutralizing IFNβ antibody. Overexpression of PAR2 reduced the basal IFNβ expression. Moreover, a direct interaction between PAR2 and Toll-like receptor 3 was observed. PAR2 expression in endomyocardial biopsies of patients with nonischemic cardiomyopathy was positively correlated with myocardial inflammation and negatively with IFNβ expression and left ventricular ejection fraction. CONCLUSIONS PAR2 negatively regulates the innate immune response to CVB3 infection and contributes to myocardial dysfunction. The antagonism of PAR2 is of therapeutic interest to strengthen the antiviral response after an infection with a cardiotropic virus.

High leptin and resistin expression in chronic heart failure: adverse outcome in patients with dilated and inflammatory cardiomyopathy.

The expression of leptin and resistin is known to be positively correlated with the incidence of chronic heart failure (CHF). Both adipokines have been implicated in immunomodulation and cardiac remodelling. Therefore, we performed for the first time a clinical study to elucidate the effects of leptin and resistin on progression of CHF in patients with non‐ischaemic dilated (DCM) and inflammatory (DCMi) cardiomyopathy.

Bivalirudin Inhibits Periprocedural Platelet Function and Tissue Factor Expression of Human Smooth Muscle Cells

AIM A major concern of stent implantation after percutaneous coronary intervention (PCI) is acute stent thrombosis. Effective inhibition of periprocedural platelet function in patients with coronary artery disease (CAD) leads to an improved outcome. In this study, we examined the periprocedural platelet reactivity after administrating bivalirudin during PCI compared to unfractionated heparin (UFH) administration. Further, the effect of bivalirudin on induced tissue factor (TF) expression in smooth muscle cells (SMC) was determined. METHODS Patients with CAD (n = 58) and double antithrombotic medication were treated intraprocedural with UFH (n = 30) or bivalirudin (n = 28). Platelet activation markers were flow cytometrically measured before and after stenting. The expression of TF in SMC was determined by real-time PCR and Western blotting. The thrombogenicity of platelet-derived microparticles and SMC was assessed via a TF activity assay. RESULTS Bivalirudin significantly diminished the agonist-induced platelet reactivity post-PCI. Compared to UFH treatment, the adenosine diphosphate (ADP) and thrombin receptor-activating peptide (TRAP)-induced thrombospondin expression post-PCI was reduced when bivalirudin was administrated during intervention. In contrast to UFH, bivalirudin reduced the P-selectin expression of unstimulated and ADP-induced platelets post-PCI. Moreover, bivalirudin inhibited the thrombin-, but not FVIIa- or FVIIa/FX-induced TF expression and pro-coagulant TF activity of SMC. Moreover, bivalirudin reduced the TF activity of platelet-derived microparticles postinduction with TRAP or ADP. CONCLUSIONS Bivalirudin is better than UFH in reducing periprocedural platelet activation. Moreover, thrombin-induced TF expression is inhibited by bivalirudin. Thus, bivalirudin seems to be a better anticoagulant during PCI than UFH.

Postmenopausal women have an increased maximal platelet reactivity compared to men despite dual antiplatelet therapy.

Dual antiplatelet medication with acetylsalicylic acid (ASA) and clopidogrel is the main therapy for patients with stable coronary vessel disease (CVD) after percutaneous coronary intervention (PCI). Despite platelet inhibition subgroups of patients have been shown to exhibit an increase of risk for adverse cardiovascular events. The aim of our study was to elucidate the influence of sex on platelet reactivity in patients with CVD under medication with ASA and clopidogrel. Two hundred and thirty patients with CVD on combined therapy with ASA (100 mg/day) and clopidogrel (75 mg/day) were included into our study. These patients were divided into a male (n = 128) and female (n = 102) group. Platelet reactivity was assessed by impedance aggregometry. Women demonstrated a significantly higher thrombin receptor-activating peptide (TRAP)-induced platelet reactivity than men (male 79.43 ± 28.55 U vs. female 89.3 ± 30.69 U; P < 0.05). The ADP-induced (male 19.81 ± 15.51 U vs. female 23.73 ± 17.68 U; P > 0.05) or arachidonic acid-induced (male 10.3 ± 12.87 U vs. female 12.76 ± 14.44 U; P > 0.05) platelet aggregation did not differ significantly between women and men. A multivariate linear regression model revealed female sex to be a significant prognostic marker for an increased TRAP-induced platelet reactivity, independent of the ASA and clopidogrel-associated platelet function inhibition. Sex differences did not influence the effectiveness of ASA or clopidogrel-mediated platelet function inhibition. Nevertheless, women had a significantly increased maximal platelet reactivity compared to men despite antiplatelet therapy.

Diadenosine polyphosphates Ap3A and Ap4A, but not Ap5A or Ap6A, induce proliferation of vascular smooth muscle cells

Depending on the number of phosphate groups, diadenosine polyphosphates (ApnA, Ap3A, Ap4A, Ap5A and Ap6A) differ in properties such as proliferation, apoptosis, vasoconstriction and vasodilatation of vascular smooth muscle cells (VSMCs). Possible signaling pathways leading to effects such as proliferation are still unknown. This study examined the proliferative effects of diadenosine polyphosphates on VSMCs and their intracellular pathways. Proliferation of VSMCs was measured by the cell count and [(3)H] thymidine incorporation. Phosphorylation of the MAP kinases ERK1/2 was determined by Western blotting. Single-cell [Ca(2+)](i) measurements were done to determine the influence of [Ca(2+)](i) on intracellular signaling. Stress fiber formation was assessed by fluorescence microscopy to detect an influence of G alpha(12). Ap3A and Ap4A, but not Ap5A or Ap6A, were shown to increase proliferation of VSMCs by activating P2Y receptors, which leads to stimulation of the Ras-Raf-MEK-ERK1/2 cascade. Ap3A- and Ap4A-induced activation of the MAP kinases ERK1/2 was dependent on a signaling pathway that included the EGF receptor, PKC, PLCbeta and the increase of [Ca(2+)](i). In conclusion, Ap3A and Ap4A, but not Ap5A or Ap6A, induce proliferation of VSMCs by a signaling pathway that begins with activation of P2Y receptors and leads to stimulation of the MAP kinases ERK1/2.

Leptin and resistin induce increased procoagulability in diabetes mellitus

BACKGROUND Patients with diabetes mellitus (DM) suffer from an increased risk of cardiovascular events caused by thrombotic conditions. Adipose tissue might play a crucial role in this pathogenesis by synthesis of procoagulant mediators. This study was performed to elucidate the role of the adipocytokines leptin and resistin in the development of hypercoagulability and hypofibrinolysis under diabetic conditions. METHODS Sixty two patients with or without DM were included in our study to measure leptin, resistin and tissue factor (TF) plasma concentrations. Moreover, flow chamber experiments were performed to assess factor Xa and plasmin activity on the surface of HUVECs. Western blot and real-time PCR were performed to determine mRNA and protein expression of main factors of the coagulation and fibrinolytic system. RESULTS Patients with diabetes showed increased levels of leptin and resistin (leptin: 25.69±13.9 vs. 15.98±17.5 ng/mL, p<0.05; resistin: 2.61±0.6 vs. 1.19±0.7 ng/mL, p<0.05), which were positively correlated with TF. In vitro, leptin and resistin induced increased factor Xa activity (leptin: 4.29±0.57-fold, p<0.05; resistin 4.19±0.7-fold, p<0.05 vs. control) on HUVECs as also reflected by elevated TF mRNA and protein expression. Moreover, stimulatory (plasminogen activator inhibitor 1) and inhibitory (tissue plasminogen activator) mediators of the fibrinolytic cascade were induced by leptin and resistin, leading to a balanced plasmin activity regulation. CONCLUSIONS Leptin and resistin lead to a procoagulant state in HUVECs by inducing TF expression. This mechanism might be one explanation for the prothrombotic state observed under diabetic conditions.

High molecular weight adiponectin correlates positively with myeloperoxidase in patients with type 2 diabetes mellitus

Adiponectin (APN) is present in human plasma as a low molecular weight (LMW), a middle molecular weight (MMW) and a high molecular weight form (HMW). As a support to determine properties such as anti-atherogenic or atherogenic effects, recent clinical studies suppose to determine the ratio of each APN multimer to total APN but not the absolute plasma concentration of APN. In the present study, the correlation of APN and its multimers with myeloperoxidase (MPO), an enzyme with pro-inflammatory properties, was examined in patients with type 2 diabetes mellitus. MPO and APN serum levels were assessed in 49 patients with type 2 diabetes mellitus at the beginning and at the end of an anti-diabetic treatment. After treatment a significant increase in the ratio of HMW to total APN (from 0.43+/-0.16 to 0.59+/-0.14, p<0.05) was found. Before treatment, HMW-APN was correlated positively with MPO (r=0.314, p<0.05). Moreover, a positive correlation was observed between the increased HMW ratio and MPO during treatment (r=0.304, p<0.05). HMW-APN correlates positively with MPO in patients with type 2 diabetes. Therefore, HMW-APN may exert possible pro-inflammatory effects in type 2 diabetes.

Der Notarzt im Altenheim – Vorurteil und Wirklichkeit

ZusammenfassungHintergrundAufgrund der Entwicklung der Bevölkerungspyramide steigt der Anteil älterer Patienten stetig. Weit verbreitet ist die Meinung, dass die Behandlung akut lebensbedrohlicher Erkrankungen im Rettungsdienst durch eine überproportional hohe Rate an unnötigen Alarmen für alte Menschen in Altenheimen gefährdet sei. Ziel der vorliegenden Studie war es, diese Beurteilung durch Zahlen und Fakten zu bestätigen oder zu widerlegen.Patienten und MethodenÜber 6 Monate wurden 2702 Notarzteinsätze des Notarztstützpunkts der Charité Universitätsmedizin Berlin, Campus Benjamin Franklin, analysiert, um Einsätze in Altenheimen (n = 368) mit denen außerhalb von Altenheimen (n = 2237) zu vergleichen. Hierfür wurden die Charakteristika der Patienten und Parameter wie die Uhrzeit des Einsatzes, die Art der Erkrankung und die daraus folgende Handlungen des Notarztes erhoben.ErgebnisseEinsätze in Altenheimen betrafen 13,6 % der Alarme. Der Schweregrad der Erkrankung von Patienten in und außerhalb von Altenheimen unterscheidet sich nicht. Dementsprechend war auch die Rate einer medikamentösen Behandlung durch den Notarzt unabhängig vom Umstand, ob der Patient in einem Altenheim betreut wird. Allerdings wurden Patienten in Altenheimen signifikant weniger in Krankenhäuser eingewiesen (p = 0,002).SchlussfolgerungDurch den Vergleich der Notarzteinsätze konnte das Vorurteil über überproportional gehäufte, nicht sinnvolle und unbedeutende Notarzteinsätze in Altenheimen nicht bestätigt werden.AbstractBackgroundDue to changes in the population pyramid, the proportion of elderly people is constantly rising. This fact leads to the opinion among rescue personal that the capacity of the emergency system to treat life-threatening conditions might be at risk due to unnecessary alarms in retirement homes. The aim of our study was to collect data and facts to either prove or reject this opinion.Patients and methodsDuring a 6-month period 2702 alarms for emergency physicians stationed at Charité Universitätsmedizin Berlin, Campus Benjamin Franklin were analyzed to compare alarms in nursing homes (n = 368) to those outside retirement homes (n = 2237). We recorded patient characteristics, the time of the emergency call, the diagnosis, and the measures taken by the emergency physician.ResultsIn all, 13.6 % of alarms concerned patients in nursing homes. The severity of disease in and outside nursing homes was not different. Emergency physicians also administered drugs at a similar rate in both groups. However, referral to an emergency room was significantly lower for retirement home patients (p = 0.002).ConclusionThe opinion that alarms in retirement homes are of lower importance could not be confirmed.