Vitamin A-induced cholestatic hepatitis: a case report

We report a case of intrahepatic cholestasis due to chronic vitamin A supplementation. A 70-year-old woman was admitted to the hospital for jaundice and reduced nutritional and general status with a 2-month history of increasing cholestasis. Some years previously she had suffered from breast and ovarian cancer with subsequent surgery and chemotherapy. Chemotherapy was terminated one month before elevated serum transaminase activities and cholestatic serum markers were noted. Following the chemotherapy, supportive care included weekly vitamin A injections (100,000 IU per injection). Liver biopsy showed an acute toxic liver injury with focal parenchymal necrosis, sinusoidal lesions, inflammatory infiltrate (round cells, macrophages), and activation and proliferation of stellate cells. The hepatic vitamin A concentration was found to be significantly elevated. There were no signs of intrahepatic metastasis or liver cirrhosis. Treatment with ursodeoxycholic acid rapidly improved the cholestasis and led to a total recovery after three weeks.

[Helping antibodies. Targeted antithrombotic and fibrinolytic therapy]

The development of monoclonal antibodies facilitated an enormous progress in modern medicine in the last years. The targeted inhibition of defined molecular structures allows therapeutic concepts, which before were inconceivable. There are numerous antibodies in clinical use within the area of tumour therapy, chronically inflammatory diseases, transplantation, infections and also in cardiovascular medicine. Different antibody formats are used such as IgG molecules, Fab fragments and single chain antibodies. Single chain antibodies represent the smallest functional form of the antibody and are used preferentially as recombinant antibodies. The therapeutic possibilities of antibody technology are extended by fusion to radioactive or therapeutically active substances. This review focuses on the application of antibodies and fusion proteins as antithrombotic and fibrinolytic drugs. The use of antibodies allows the development of inhibitory agents with clearly defined functional properties, as for example for activation-specific GPIIb/IIIa-blockade. In addition antibodies can be used for targeting antithrombotic and fibrinolytic agents to the thrombus, allowing an effective local action with less bleeding complications.

[Factor Xa-inhibition in interventional cardiology]

The recently established correlation between bleeding events and clinical outcomes in patients with coronary artery disease undergoing either non-invasive or invasive treatment for acute coronary syndromes (ACS) highlights the unmet need for safer anticoagulants that can be used in conjunction with dual or triple antiplatelet therapy. The central position of the coagulation factors IIa and Xa within the coagulation system account for their prominent role as targets for anticoagulants. Unfractionated heparin (UFH) achieves a variable indirect inhibition of both factors. The low molecular weight heparins (LMWH) show favourable pharmacokinetics over UFH and have a more pronounced activity against factor Xa as opposed to thrombin which may partially account for the benefits observed with LMWH in clinical trials. New agents that have been developed allow for a selective inhibition of factor Xa. Recently, exciting results have been reported with an indirect selective inhibitor of factor Xa in patients with ST-elevation myocardial infarction (STEMI) -acute coronary syndromes (ACS) and non-STEMI-ACS. In this article the pharmacology of the indirect selective factor Xa inhibitors Fondaparinux and Idraparinux will be discussed along with the direct selective factor Xa inhibitors DX-9065a and Otamixaban in the setting of interventional cardiology.

[Inducing collaterals in due time. Arteriogenesis as a preventive principle]

A stimulation of collateral vessel growth is an attractive alternative therapeutic tool especially for patients with diffuse occlusive vessel disease. Extensive in vivo and in vitro studies in the preceding decades have led us to a thorough understanding of basic arteriogenic principles. Due to the timeline of naturally occurring arteriogenesis, a well-timed therapeutic induction appears to be limiting for effective proarteriogenic therapies in high-risk patients. Potential therapeutic approaches are based on a stimulation of monocyte function through cytokine application. First clinical studies have, nevertheless, demonstrated the limits of a unifactorial therapy. Therefore, a stimulation of the mechanical inductor of arteriogenic proliferation, i. e. fluid shear stress acting on the arteriolar endothelium, appears as a feasible therapeutic addition. Current results show the feasibility of that principle not only through active physical training, but also through passive application of an external counterpulsation (EECP), a method showing promising first results in the clinical setting.

[Is stent thrombosis the new Achilles heel of interventional cardiology? State of the Art clinical trials, causes and approaches for prevention]

Coronary stents are the mainstay of percutaneous coronary intervention. Stent thrombosis is a potentially catastrophic and often life-threatening complication. If it occurs it presents in up to 80% as myocardial infarction, about half of the affected patients die from this complication. The dual antiplatelet therapy has markedly reduced its occurrence. Today, stent thrombosis occurs in <1%, usually as a delayed event; but compared to bare metal stents the overall incidence has not increased in meta-analyses of randomized trials. The advent of drug-eluting stents (DES) has raised concerns regarding the occurrence of delayed stent thrombosis. Delayed arterial wall healing as well as prothrombotic characteristics of the drug eluting stent itself may contribute to stent thrombosis. In order to prevent stent thrombosis a standardized fixed dose antiplatelet therapy with ASA and clopidogrel is recommended. But, their efficacy depends on patient's individual characteristics such drug metabolism. Therefore, individual determination of platelet function in each patient undergoing stent implantation may help to avoid prothrombotic as well as bleeding complications.

Occlusion of iatrogenic pseudoaneurysms with percutaneous ultrasound guided thrombin injection

BACKGROUND

Pseudoaneurysm is a common complication of cardiac catheterization and coronary intervention with an incidence of 2% even in experienced centers.

PATIENTS AND METHODS

In a feasibility study conducted between December 2004 and February 2006 we enrolled 76 patients consecutively to receive local thrombin injection (mean 329 IU; range 100-800 IU) into the aneurysma sac.

RESULTS

Ultrasound guided thrombotic occlusion of pseudoaneurysms was successful after one injection in 83% of the patients, 17% of the patients required more than one injection. The overall success rate of the procedure was 98,9%. No peripheral embolisation of thrombin was noted during any injection and we registered no other complication that needed any further intervention.

CONCLUSIONS

We conclude that ultrasound guided occlusion of pseudoaneurysms using thrombin injection with a success rate of the procedure of 98,9% is feasible and safe.

Cytochrome P450 levels are altered in patients with esophageal squamous-cell carcinoma

AIM: To investigate the role of cytochrome P450 (CYP) in the carcinogenesis of squamous-cell carcinoma (SCC) in human esophagus by determining expression patterns and protein levels of representative CYPs in esophageal tissue of patients with SCC and controls.

METHODS: mRNA expression of CYP2E1, CYP2C, CYP3A4, and CYP3A5 was determined using RT-PCR in both normal and malignant esophageal tissues of patients with untreated esophageal SCC (n = 21) and in controls (n = 10). Protein levels of CYP2E1, CYP2C8, CYP3A4, and CYP3A5 were measured by Western blot.

RESULTS: Within the group of SCC patients, mRNA expression of CYP 3A4 and CYP2C was significantly lower in malignant tissue (-39% and -74%, respectively, P < 0.05) than in normal tissue. Similar results were found in CYP3A4 protein levels. Between groups, CYP3A4, CYP3A5, and CYP2C8 protein concentration was significantly higher in non-malignant tissue of SCC patients (4.8-, 2.9-, and 1.9-fold elevation, P < 0.05) than in controls. In contrast, CYP2E1 protein levels were significantly higher in controls than in SCC patients (+46%, P < 0.05).

CONCLUSION: Significant differences exist in protein levels of certain CYPs in non-malignant esophageal tissue (e.g. CYP2C8, CYP3A4, CYP3A5, and CYP2E1) between SCC patients and healthy subjects and may contribute to the development of SCC in the esophagus.

Kollateralen rechtzeitig induzieren

Die Stimulation des Kollateralgefäßwachstums (Arteriogenese) stellt eine attraktive alternative Behandlungsmethode vor allem für Patienten mit hochgradigen diffusen stenosierenden Gefäßerkrankungen dar. Ausgedehnte In-vitround In-vivo-Untersuchungen der vergangenen Dekaden haben zu einem umfassenden Verständnis der Basismechanismen der Arteriogenese geführt. Aufgrund des zeitlichen Ablaufs der kollateralen Proliferation erscheint eine rechtzeitige Induktion für Risikopatienten von entscheidender Bedeutung zu sein. Potenzielle Therapieansätze sind durch Stimulation der Monozytenfunktion (z. B. über die Applikation von Zytokinen) denkbar. Erste klinische Anwendungen zeigen jedoch die Grenzen einer unifaktoriellen Therapie, die sich allein auf die Therapie mit einem einzelnen Wachstumsfaktor stützt. Daher stellt die Aufrechterhaltung des mechanischen Induktors der vaskulären Proliferation, der endothelialen Schubspannung, eine mögliche gute Therapieaddition dar. Aktuelle Ergebnisse zeigen, dass dieses nicht nur durch körperliches Training, sondern auch durch die passive Applikation einer externen Gegenpulsation (EECP) möglich ist, eine Methode, die in der klinischen Anwendung erste vielversprechende Ergebnisse zeigt.

Faktor-Xa-Inhibition in der interventionellen Kardiologie

Eine zwei-oder dreifache antithrombozytäre Therapie kombiniert mit einer systemischen Antikoagulation, wie in der interventionellen Kardiolgie häufig angewandt, kann das Blutungsrisiko deutlich erhöhen. Wie vor kurzem gezeigt, geht ein erhöhtes Blutungsrisiko mit einer höheren Rate ischämischer Ereignisse sowie einer höheren Mortalität einher. Letzteres unterstreicht die Notwendigkeit für die Entwicklung neuer Antikoagulanzien mit besserem Sicherheitsprofil. Die zentrale Position der Gerinnungsfaktoren IIa und Xa im Gerinnungssystem machen diese zu idealen Zielen für die Entwicklung von Antikoagulanzien. Unfraktioniertes Heparin (UFH) bewirkt eine variable Inhibition beider Faktoren. Im Vergleich zu UFH weisen die niedermolekularen Heparine (NMH) vorteilhafte pharmakologische Eigenschaften auf, NMH zeigen eine stärkere Selektivität für die Inhibierung von Faktor Xa. Eine Gruppe neuer Antikoagulanzien ermöglicht die selektive Inhibition von Faktor Xa. Aktuelle klinische Studien mit einem indirekten selektiven Faktor-Xa-Inhibitor zeigen überzeugende Ergebnisse bei Patienten mit akutem Koronarsyndrom (ACS) und STStreckenhebungs-Myokardinfarkt (STEMI) sowie ACS und Non-STEMI. Dieser Artikel diskutiert die pharmakologischen Eigenschaften der indirekten selektiven Faktor-Xa-Inhibitoren Fondaparinux und Idraparinux sowie der direkten selektiven Faktor-Xa-Inhibitoren DX-9065a und Otamixaban zusammen mit deren Einsatz in klinischen Studien in der interventionellen Kardiologie.

Ist die Stentthrombose die neue Achillesferse der interventionellen Kardiologie?

Der Einsatz von Koronarstents gehört zu den Grundpfeilern der perkutanen Koronarintervention. Die Stentthrombose ist dabei eine lebensbedrohliche Komplikation. Tritt sie auf, so erleiden bis zu 80% der Betroffenen einen Myokardinfarkt, bis zu 50% versterben. Durch die duale Plättchenaggregationshemmung konnten Stentthrombosen deutlich reduziert werden; die Inzidenz liegt heute unter 1%. Mit dem Aufkommen medikamentenfreisetzender Stents hat sich die Zeitspanne des Auftretens bis hin zu mehreren Jahren nach Implantation verlängert; die Gesamtinzidenz hat sich aber in Metaanalysen der randomisierten Studien nicht erhöht.

Ursächlich ist ein verzögerter vaskulärer Heilungsprozess sowie eine Kontakt- und Medikamenten-assoziierte Thrombozytenaktivierung. Vorbeugend wird daher eine standardisierte duale plättchenhemmende Therapie mit ASS und Clopidogrel empfohlen. Ihre Wirkung hängt von individuellen Faktoren ab. Durch die Bestimmung der Thrombozytenaggregationshemmung würde eine individuelle Dosisanpassung möglich, so dass thrombotische Nebenwirkungen und Blutungskomplikationen verringert werden könnten.

Antikörper als Helfer

Der Einsatz monoklonaler Antikörper hat einen enormen Fortschritt in der modernen Medizin ermöglicht. Der gezielte Ansatz an definierten molekularen Strukturen ermöglicht Therapiekonzepte, die zuvor undenkbar waren. Mittlerweile werden zahlreiche Antikörper klinisch eingesetzt, z. B. in der Onkologie, bei der Therapie chronisch-entzündlicher Krankheiten, Infektionskrankheiten und kardiovaskulärer Erkrankungen. Hierbei werden verschiedene Formate wie IgG-Moleküle, Fab-Fragmente und Einzelkettenantikörper eingesetzt. Einzelkettenantikörper stellen die kleinste funktionelle Form des Antikörpers dar und werden bevorzugt als rekombinate Antikörper verwendet. Fusion an radioaktive oder therapeutisch aktive Substanzen erweitern die therapeutischen Möglichkeiten der Antikörpertechnologie.

In dieser Übersichtsarbeit werden die Einsatzmöglichkeiten von Antikörpern als antithrombotisch und fibrinolytische Substanzen dargestellt. Hierbei erlaubt der Einsatz von Antikörpern einerseits die Entwicklung zielgerichteter antithrombotischer Substanzen, die z. B. eine konformationsabhängige Blockade des Thrombozytenaggregationsrezeptors GPIIb/IIIa ermöglichen. Andererseits kann durch Fusion von Antikoagulanzien an Antikörper, die dann die Funktion von Pilotmolekülen übernehmen, eine Anreicherung im Thrombus mit resultierender geringerer systemischer Blutungsneigung erreicht werden.

Superparamagnetic iron oxide binding and uptake as imaged by magnetic resonance is mediated by the integrin receptor Mac-1 (CD11b/CD18): implications on imaging of atherosclerotic plaques

INTRODUCTION

Superparamagnetic iron oxide nanoparticles (SPIONs) have been successfully used for magnetic resonance imaging (MRI) of atherosclerotic plaques. Endocytosis into monocytes/macrophages has been proposed as the mechanism for SPION uptake, but a specific receptor has not been identified yet. A potential candidate is the versatile integrin Mac-1 (CD11b/CD18, alphaMbeta2), which is involved in leukocyte adhesion, complement activation and phagocytosis.

METHODS AND RESULTS

Intracellular SPION-accumulation was confirmed in cultured human monocytes using immunohistochemistry and iron staining. Recombinant cells expressing Mac-1 in different activation states as well as human monocytes with or without PMA stimulation were incubated either with an unspecific IgG or a CD11b-blocking antibody. Thereafter, cells were incubated with FITC-labeled amino-covered SPIONs or ferumoxtran-10 SPIONs and signal intensity was quantified by flow cytometry. Depending on the activation status of Mac-1, a significant increase in SPION binding/uptake was observed, independent on surface coating. Furthermore, SPION binding/uptake was significantly reduced after CD11b blockade. Results were confirmed in recombinant cells incubated with amino-PVA SPIONs and ferumoxtran-10, using T2(*)-weighted 3T MRI.

CONCLUSION

The integrin Mac-1 is directly involved in SPION binding/uptake. Thus, monocytes abundantly expressing Mac-1 and especially activated monocytes expressing activated Mac-1 may be useful vehicles for high resolution MRI labeling of atherosclerotic plaques.

[Pathophysiology of acute coronary syndrome]

This article reviews the current understanding of the pathophysiology of acute coronary syndrome and how these concepts have altered our clinical approach to the acute phase of coronary heart disease. Thrombosis due to erosion or, in most cases, rupture of a vulnerable atherosclerotic plaque underlies most acute coronary syndromes. The protective fibrous cap undergoes degradative processes controlled by inflammatory mediators that break down the interstitial collagen within the fibrous cap. Thrombus formation depends on factors in the solid-phase of the ruptured plaque as well as on fluid-phase determinants in blood. Depending on the degree of thrombus formation the subsequent obstruction of the coronary artery is followed clinically by unstable angina, non-ST- and ST-segment elevation myocardial infarction.

[Inhibition of plasmatic coagulation: what is new?]

The major goal in the development of new anticoagulant drugs is a more effective action with less adverse effects. Until now the mainly used agents are heparin and phenprocoumon or warfarin. These drugs inhibit multiple coagulation factors in different stages of the coagulation cascade. Modern drug development and the knowledge about the molecular mechanisms of the coagulation cascade allow specific inhibition of distinct phases of thrombus formation. This review focuses on the new developments in this area.

Cardiac parasympathetic regulation in obese women with binge eating disorder

OBJECTIVE

Obese individuals with a binge eating disorder (BED) differ from obese non-binge eaters (NBED) with respect to (a) eating behaviour, (b) psychiatric comorbidity and (c) level of psychosocial distress. The aim of the study was to explore whether these three factors have an influence on cardiac parasympathetic function, that is independent of obesity: as alterations in cardiac parasympathetic function may have a role in the higher cardiovascular mortality that is present in obese individuals.

METHODS

In total, 38 obese women (BMI>30 kg/m(2)), with a BED and 34 age and BMI matched healthy controls (NBED) completed a laboratory stress protocol that incorporated a baseline resting period, Head-up Tilt Testing (HUT) and two challenging mental tasks. Heart rate and blood pressure were measured continuously during the protocol. Parasympathetic cardiac regulation was assessed as the high frequency component of heart rate variability (HRV-HF).

RESULTS

Mental challenge led to an augmented reduction of HRV-HF in obese binge eaters, which was linked to the binge eating frequency and hunger perception, but not to psychiatric comorbidity. During baseline conditions and HUT, no significant differences in parasympathetic measures were observed between the two subject groups.

CONCLUSION

Subjects with a BED showed greater reduction in parasympathetic cardiac control (HRV-HF) during mental stress, suggesting higher stress vulnerability in women with a BED. Longitudinal investigations are necessary to evaluate whether this is associated with an increased cardiovascular mortality.

Therapeutisch induzierte Arteriogenese im Gehirn

Stroke is the leading cause of disability and a major cause of death in Germany and the western world. Ischemic stroke involves different pathophysiologic mechanisms such as thromboembolic vascular occlusion, cerebral micro- or macroangiopathy, extracranial arterial stenosis, and cardiac embolism. Experimental and clinical studies have shown that arteriogenesis, the adaptive growth of pre-existing collateral arteries, can be therapeutically enhanced in peripheral circulation and the heart. We examined the consequences to time course and hemodynamics of brain arteriogenesis in a chronic hypoperfusion model following systemic administration of the hemopoietic growth factor called granulocyte macrophage colony stimulating factor (GM-CSF). Treatment with GM-CSF led to the growth of intracranial collateral arteries, which improved the cerebral hemodynamic reserve and significantly reduced energy failure when brains were additionally challenged by hypotension. Therapeutically induced arteriogenesis may be of considerable interest for preventing infarction in patients with uncompensated cerebrovascular disease.

Evidence for a differential functional regulation of the two beta(3)-integrins alpha(V)beta(3) and alpha(IIb)beta(3)

The functional regulation of integrins is a major determinant of cell adhesion, migration and tissue maintenance. The binding of cytoskeletal proteins to various sites of integrin cytoplasmic domains is a key mechanism of this functional regulation. Expression of recombinant integrin alpha(IIb)beta(3) and alpha(M)beta(2) lacking the GFFKR-region in CHO cells results in constitutively activated integrins. In contrast, CHO cells stably expressing either a GFFKR-deleted alpha(V(del))beta(3) or a FF to AA-substituted alpha(V(AA))beta(3) do not reveal a constitutively activated integrin. Adhesion to immobilized fibrinogen is strongly impaired in alpha(V(del))beta(3) or alpha(V(AA))beta(3)-expressing cells, whereas it is not impaired in alpha(IIb)beta(3) and alpha(M)beta(2), both lacking the GFFKR-region. In a parallel plate flow chamber assay, alpha(V)beta(3)-expressing cells adhere firmly to fibrinogen and spread even at shear rates of 15 to 20 dyn/cm(2), whereas alpha(V(del))beta(3) or alpha(V(AA))beta(3) cells are detached at 15 dyn/cm(2). Actin stress fiber formation and focal adhesion plaques containing alpha(V)beta(3) are observed in alpha(V)beta(3) cells but not in alpha(V(del))beta(3) or alpha(V(AA))beta(3)-expressing cells. As an additional manifestation of impaired outside-in signaling, phosphorylation of pp125(FAK) was reduced in these cells. In summary, we report that the GFFKR-region of the alpha(V)-cytoplasmic domain and in particular two phenylalanines are essential for integrin alpha(V)beta(3) function, especially for outside-in signaling. Our results suggest that the two beta(3)-integrins alpha(IIb)beta(3) and alpha(V)beta(3) are differentially regulated via their GFFKR-region.

Langzeit-Antiaggregation mit Clopidogrel statt ASS, Clopidogrel und ASS

Eine dauerhafte Thrombozytenaggregationshemmung ist ein essenzieller Bestandteil der Sekundärprophylaxe nach akutem Koronarsyndrom (ACS). Seit Ende der 1980er Jahre des vergangenen Jahrhunderts ist die Thrombozytenaggregationshemmung mit Azetylsalizylsäure (ASS) als eine effektive und sichere Therapie für diese Indikation etabliert. Etwa ein Jahrzehnt später wurde mit der Einführung der Thienopyridine eine kombinierte synergistische Thrombozytenaggregationshemmung möglich, die insbesondere in der interventionellen Kardiologie neue Möglichkeiten eröffnete. Das zuerst verfügbare Ticlopidin ist mittlerweile, aufgrund der besseren pharmakologischen Eigenschaften und des günstigeren Profils an unerwünschten Arzneimittelwirkungen durch Clopidogrel weitgehend ersetzt. Nach wie vor hat die Standardtherapie mit ASS in niedriger Dosierung (mindestens 75 mg/d) als Langzeittherapie in der Sekundärprophylaxe einen hohen Stellenwert. Clopidogrel bietet nach den aktuellen Studien jedoch eine ebenso sichere und effektive Alternative. Nach PTCA mit Implantation eines herkömmlichen Metallstents sollte zur Verhinderung einer akuten Stentthrombose für mindestens vier Wochen eine Kombinationstherapie mit ASS und Clopidogrel durchgeführt werden. Bei ACS ohne ST-Strecken-Hebungsinfarkt ist die Kombination von ASS und Clopidogrel besser als die alleinige Gabe von ASS. Aktuelle Daten scheinen dies auch für das ACS mit ST-Strecken-Hebungsinfarkt zu belegen. Ob generell die dauerhafte Kombinationstherapie von ASS mit Clopidogrel zur Sekundärprophylaxe sicher und evtl. effektiver ist, wird diskutiert.

[Inhibition of platelet aggregation for the secondary prevention after ACS: when clopidogrel instead of ASA, when clopidogrel and ASA?]

Long-term inhibition of platelet aggregation is essential for the secondary prevention after acute coronary syndromes (ACS). Inhibition of platelet aggregation with acetylsalicylic acid (ASA) has been established as a safe and effective therapy in this indication already end of the eighties in the preceding century. A decade later, with the introduction of the thieno-pyridines, combined platelet aggregation inhibition became possible. This opened the door for new treatment strategies in interventional cardiology. The first substance, ticlopidine was more or less replaced by the newer substance clopidogrel, which has improved pharmacological properties and less side effects. Low dose ASA (75 mg/d) is still regarded as the standard therapy for secondary prevention after ACS. However, large clinical trials established clopidogrel as at least as effective and safe as ASA in this indication. Following PCI with bare metal stent implantation, a combined therapy of ASA and clopidogrel should be given for at least 4 weeks. After ACS with non-ST-elevation myocardial infarction the combined therapy with ASA and clopidogrel gives a better outcome than ASA alone. Recently published clinical trials show superiority of this strategy in patients with ST-elevation myocardial infarction, too. If a combined long-term platelet aggregation inhibition with ASA and clopidogrel will be safe and more effective for secondary prevention is discussed.

Inhibition der plasmatischen Koagulation

Das wichtigste Ziel bei der Entwicklung neuer Antikoagulanzien ist eine effektivere Wirkung mit weniger unerwünschten Arzneimittelwirkungen. Bisher eingesetzte Therapeutika wie Heparin und Phenprocoumon inhibieren mehrere Faktoren in verschiedenen Phasen der Blutgerinnung. Die moderne Arzneimittelentwicklung und detaillierte Kenntnis über die molekularen Mechanismen der Koagulation ermöglichen den gezielten Eingriff in ganz spezifischen Phasen der Gerinnung. In dieser Übersichtsarbeit werden die neuen Entwicklungen in diesem Bereich vorgestellt und deren Wirkungsmechanismen erläutert.

[Anticoagulant and thrombolytic agents in acute coronary syndrome]

The term acute coronary syndrome (ACS) pertains to the instable and life-threatening forms of a clinically manifest coronary artery disease with biochemical and/or electrocardiographic evidence od myocyte cell death. In detail, it includes the unstable angina pectoris, the non-ST segment elevation myocardial infarction (NSTEMI) the ST segment elevation myocardial infarction (STEMI) and as well the sudden cardiac death. As early reperfusion of ischaemic myocardium is the most effective way for limiting infarct size by restoring the balance between myocardial oxygen supply and demand, it is the most important therapeutic goal to achieve early and complete antegrade flow in the occluded or restricted vessel, related with a reduction of short and longtime complications as heart failure and severe arrhythmias. It is generally accepted, that the primary percutaneous coronary intervention (PCI) is the method of choice in acute myocardial infarction (STEMI) to restore TIMI-3 blood flow in occluded coronary arteries, if this can be performed within two hours of symptom onset and by a highly specialized team. Since this requirements are only met in 20% of hospitals caring for patients with STEMI in Germany, the therapy with thrombolytic and anticoagulant agents plays still an important role. Apart from a rapid and effective prehospital primary care, it depends furthermore on a differentiated anticoagulatory and antithrombotic therapy during coronary intervention to get optimal results.

Effect of oral administration of freshly pressed juice of Echinacea purpurea on the number of various subpopulations of B- and T-lymphocytes in healthy volunteers: results of a double-blind, placebo-controlled cross-over study

BACKGROUND

In a recent double-blind placebo-controlled crossover-study the "immune stimulatory" effects (activation of macrophages leading to enhanced phagocytosis and production of several cytokines) of Echinacea purpurea preparations (EPP) which were observed in vitro experiments and following parenteral administration could not be confirmed following oral application of the drug in healthy volunteers. The aim of the present study was to investigate whether or not oral EPP has any effect on important lymphocyte-subpopulations.

SUBJECTS AND METHODS

Forty healthy male volunteers (age range 20-40 years) participated in the study. They received either a commercially available pressed juice of E. purpurea herbs or placebo juice using a double-blind placebo-controlled cross-over design with two treatment periods of 14 days. The total number of lymphocytes and 12 subgroups of lymphocytes were determined by using Flow-cytometry.

RESULTS

After 1 week of treatment with verum the mean value of the total number of lymphocytes decreased slightly (-6%, p = 0.033) compared to the initial value. Treatment for 1 and 2 weeks with EPP had only minor effects on two of the 12 subtypes of lymphocytes. No significant changes were observed in the verum period for the following types of cells: T- and B-lymphocytes, CD4 + - and CD8 + -T-lymphocytes including the subgroups of "naive" and "memory" CD4 + - and CD8 + -T-lymphocytes as well as the natural killer cells. Using a modified version of the Wilcoxon-Mann-Whitney-U-test, which is claimed to be optimal for the evaluation of the results of studies with a cross-over design, a significant difference was found for the number of CD8 + -T-lymphocytes and natural killer cells corresponding to either a decrease during treatment with verum or an increase in the number of these cells in the placebo period.

CONCLUSION

Oral administration of EPP for 1 and 2 weeks has only minor effects on two out of 12 lymphocyte subpopulations determined in the study. The small differences observed in the number of CD8 + -T lymphocytes and natural killer cells are only of questionable physiological relevance.

Pharmacology and clinical trial results of saruplase (scuPA) in acute myocardial infarction

Saruplase is the non-glycosylated form of single chain urokinase-type plasminogen activator; it is produced by recombinant technique in Escherichia coli. Saruplase has plasminogen activating properties; it can also be cleaved to the potent plasminogen activator, double chain urokinase, resulting in the generation of plasmin. By means of a positive feedback mechanism, plasmin itself is able to cleave saruplase. At present, a bolus of 20 mg followed by an infusion of 60 mg over 1 h and preceded by a heparin bolus of 5000 U, represents the standard saruplase regimen. The PRIMI trial showed that this standard saruplase regimen achieves higher early patency rates than streptokinase. In the COMPASS trial, saruplase has been shown to be at least as effective as streptokinase, in terms of 30 day mortality. A comparative trial with urokinase (SUTAMI) resulted in similar late coronary patency. Saruplase has been tested against alteplase (100 mg over 180 min) in the SESAM trial. The early coronary patency and safety of both regimens were comparable. In a recent study, three bolus applications of saruplase have been investigated. A double bolus of 40 mg each given 30 min apart, is suggested to be more effective than standard saruplase, but concerns about safety remain. Further studies are required to assess safety of the double bolus regimen, and to compare saruplase with the gold-standard of frontloaded alteplase, or the equivalent double bolus reteplase regimen.

International multicentre trial protocol to assess the efficacy and safety of tenecteplase during cardiopulmonary resuscitation in patients with out-of-hospital cardiac arrest: the Thrombolysis in Cardiac Arrest (TROICA) Study

Prehospital cardiac arrest has been associated with a very poor prognosis. Acute myocardial infarction and massive pulmonary embolism are the underlying causes of out-of-hospital cardiac arrest in 50-70% of patients. Although fibrinolysis is an effective treatment strategy for both myocardial infarction and pulmonary embolism, clinical experience for this therapy performed during resuscitation has been limited owing to the anticipated risk of severe bleeding complications. The TROICA study is planned as one of the largest randomized, double-blind, placebo-controlled trials to assess the efficacy and safety of prehospital thrombolytic therapy in cardiac arrest of presumed cardiac origin. Approximately 1000 patients with cardiac arrest will be randomized at approximately 60 international study centres to receive either a weight-adjusted dose of tenecteplase or placebo after the first dose of a vasopressor. Patients can be included if they are at least 18 years, presenting with a witnessed cardiac arrest of presumed cardiac origin, and if either basic life support had started within 10 min of onset and had been performed up to 10 min or advanced life support is started within 10 min of onset of cardiac arrest. Primary endpoint of the study is the 30-day survival rate, and the coprimary endpoint is hospital admission. Secondary endpoints are the return of spontaneous circulation (ROSC), survival after 24 h, survival to hospital discharge, and neurological performance. Safety endpoints include major bleeding complications and symptomatic intracranial haemorrhage.

A novel in vitro system, the integrated discrete multiple organ cell culture (IdMOC) system, for the evaluation of human drug toxicity: comparative cytotoxicity of tamoxifen towards normal human cells from five major organs and MCF-7 adenocarcinoma breast cancer cells

In vitro assays involving primary cells are used routinely to evaluate organ-specific toxic effects, for instance, the use of primary hepatocytes to evaluate hepatotoxicity. A major drawback of an in vitro system is the lack of multiple organ interactions as observed in a whole organism. A novel cell culture system, the integrated discrete multiorgan cell culture system (IdMOC), is described here. The IdMOC is based on the "wells within a well" concept, consisting of a cell culture plate with larger, containing wells, within each of which are multiple smaller wells. Cells from multiple organs can be cultured initially in the small wells (one organ per well, each in its specialized medium). On the day of toxicity testing, a volume of drug-containing medium is added to the containing well to flood all inner wells, thereby interconnecting all the small wells. After testing, the overlying medium is removed and each cell type is evaluated for toxicity using appropriate endpoints. We report here the application of IdMOC in the evaluation of the cytotoxicity of tamoxifen, an anticancer agent with known human toxicity, on primary cells from multiple human organs: liver (hepatocytes), kidney (kidney cortical cells), lung (small airway epithelial cells), central nervous system (astrocytes), blood vessels (aortic endothelial cells) as well as the MCF-7 human breast adenocarcinoma cells. IdMOC produced results that can be used for the quantitative evaluation of its anticancer effects (i.e., cytotoxicity towards MCF-7 cells) versus its toxicity toward normal organs (i.e., liver, kidney, lung, CNS, blood vessels).

Antikoagulanzien und Thrombolytika beim akuten Koronarsyndrom

Unter dem Begriff des akuten Koronarsyndroms (ACS) werden die instabilen und somit lebensbedrohlichen Formen der klinisch manifesten koronaren Herzkrankheit zusammengefasst. Dies sind die instabile Angina pectoris, der Nicht-ST-Strecken-hebende (NSTEMI) und der ST-Strecken-hebende Myokardinfarkt (STEMI) sowie der plötzliche Herztod.

Wichtigstes therapeutisches Ziel ist die rasche und vollständige Wiedereröffnung der eingeengten oder verschlossenen Koronararterie, um den Verlust an kontraktiler Muskelmasse zu minimieren. Unangefochtene Therapie der Wahl ist hierfür die primäre perkutane Koronarintervention (PCI), wenn diese innerhalb von zwei Stunden von einem erfahrenen Team vorgenommen werden kann. Da diese Vorausetzung in Deutschland nur an 20% der Myokardinfarkt-Patienten versorgenden Kliniken erfüllt ist, kommt der medikamentösen Therapie weiterhin eine große Bedeutung zu. Neben einer schnellen Primärversorgung ist auch die optimale gerinnungs- und aggregationshemmende Therapie während der Koronarintervention mit dem Primär- und Langzeiterfolg eng korreliert. Entsprechend den aktuellen Erkenntnissen ist es die Kombinationstherapie verschiedener Substanzen, die unter Berücksichtigung von Kontraindikationen das bestmögliche Ziel erreichen lässt.

Inhibition of platelet activation and aggregation

It has recently been established that platelets are involved at all stages of atherosclerotic disease. A major platelet mediated process is the acute vessel closure at the site of atherosclerotic plaque rupture and there is emerging evidence for platelet adhesion to endothelial cells in the early stage of atherosclerotic disease. This, through engagement of other cells, leads to the development of the atherosclerotic plaque. Beside dietary, cholesterol- and lipid-lowering, and other pharmaceutical approaches antiplatelet therapy plays an important part in the treatment of atherosclerosis and its multifarious clinical manifestations. Antiplatelet therapy and the currently approved substances for oral (acetylsalicylic acid, dipyridamole, cilostazol, ticlopidin and clopidogrel) and parenteral (acetylsalicylic acid, abciximab, eptifibatide and tirofiban) administration are discussed in the following section. Attention is given to each single agent and its mechanism of action. Differences in pharmacodynamic and pharmacokinetic properties are elucidated and outlook on future antiplatelet strategies is discussed.

Modulation of Cytokine Release by Differentiated CACO-2 Cells in a Compartmentalized Coculture Model with Mononuclear Leucocytes and Nonpathogenic Bacteria

To further investigate the interaction between human mononuclear leucocytes [peripheral blood mononuclear cells (PBMC)] and enterocytes, the effect of a confluent layer of differentiated CACO-2 cells on cytokine kinetics during challenge with bacteria in a compartmentalized coculture model was investigated. Nonpathogenic Escherichia coli were added either to the apical or the basolateral compartment of this transwell cell culture system, the latter of which contained human leucocytes. The synthesis of tumour necrosis factor (TNF-alpha) and interleukin (IL)-12 was significantly suppressed by CACO-2 cells when leucocytes were stimulated directly with bacteria. This suppression was not paralleled by changes in the production of IL-10, IL-6 and transforming growth factor (TGF)-beta. When the bacteria were applied apically to the CACO-2 cell layer, the production of TNF-alpha, IL-12, IL-1beta, IL-8, IL-6, IL-10, TGF-beta and interferon-gamma was pronouncedly lower as compared to the bacterial stimulation of leucocytes beneath the CACO-2 cells. In the latter experiments, IL-6, IL-8 and TNF-alpha were the cytokines being mostly induced by apical addition of E. coli. Quantitative mRNA expression analysis revealed that IL-8 gene expression was equally induced in both CACO-2 and PBMC after apical stimulation with bacteria. Of note, bacteria-stimulated CACO-2 cells produced little or no cytokines in the absence of leucocytes, supporting the concept of leucocyte-epithelial cell cross-talk in modulating cytokine responses in the gut mucosa.

[Treatment of acute myocardial infarction-state of the art]

Clinical data in acute STEMI clearly show the superiority of intracoronary intervention vs thrombolysis. Short- and long-term events with the exception of major bleeding are significantly reduced by PTCA. Recent clinical data show that even transfer to interventional centers does not reduce the overall benefits significantly. If transfer is necessary, onset of symptoms within less than 3 hours might indicate equality in mortality outcome for both treatments. To ensure optimal outcome of PTCA, intracoronary interventions have to be performed on a regular basis. A very low frequency of interventions levels the benefit of PTCA vs lysis.

Herzrhythmusst�rungen und pl�tzlicher Herztod bei Frauen

BACKGROUND

Gender specific cardiac arrhythmias have been recognized for more than 80 years. The impact of gonadal steroids on the autonomic system and on the cellular electrophysiology of the cardiac autonomic system are discussed as is a direct genetic disposition on a cellular, functional or metabolic level. We nevertheless have to be aware of age- and gender-specific differences of heart diseases, which have an impact on the incidence, form and severity of cardiac arrhythmias.

CARDIAC ARRHYTHMIAS IN WOMEN

Gender-specific electrophysiologic differences like a higher basic heart rate and a longer QT-interval, beginning after puberty, are the main changes in ECGs in women and have a strong relationship to constitutional and hormonal influences. Supraventricular arrhythmias, i. e. in women sinus and AV-nodal-reentry tachycardias, less frequently Wolff-Parkinson-White tachycardias, may show clearly cyclical differences. Atrial fibrillation is more frequent in women, is more symptomatic, and there are more problems in therapy. Ventricular arrhythmias, occurring equally in healthy persons, show a strong relationship to coronary artery disease in men, which is less significant in women (in women more arrhythmogenic co-factors). Women suffer from acquired and congenital long-QT syndrome, and consequently more often from torsade-de-pointes tachycardias (stronger drug-induced QT-lengthening, more short-long sequences, differences in Ikr sensitivity). Sudden cardiac death is three times more often in men. Women suffer from it about ten years later; it is a more heterogenous phenomenon than in men, and the prognosis is worse. Women are underrepresented in controlled studies for primary and secondary prevention compared to men.

CONCLUSIONS

As the underlying reasons of gender-specific differences in cardiac arrhythmias are not known in detail, the findings discussed imply the necessity of more basic studies to evaluate gender-specific solutions for risk stratification and therapy.

Construction and characterization of a recombinant plasminogen activator composed of an anti-fibrin single-chain antibody and low-molecular-weight urokinase

BACKGROUND

Targeting of plasminogen activators to the fibrin component of a thrombus by antibodies directed against human fibrin can enhance their thrombolytic potency and clot specificity.

OBJECTIVES

To overcome the disadvantages of chemical conjugation, we investigated whether the recombinant fusion of a single-chain antibody and a plasminogen activator results in an active bifunctional molecule that might be useful as a therapeutic agent.

METHODS

The cDNA of low-molecular-weight single-chain urokinase-type plasminogen activator, comprising amino acids Leu144-Leu411 (scuPA(LMW)), was cloned from human endothelial cells and fused to a single-chain antibody specific for the 7 N-terminal amino acids (beta(15-22)) in the beta-chain of human fibrin (scFv(59D8)). The fusion protein was purified using affinity chromatography with the beta(15-22)-peptide of human fibrin.

RESULTS

Purified scFv(59D8)-scuPA(LMW) migrated as a 60-kDa band, which is consistent with a molecule composed of one scFv(59D8) and one scuPA(LMW) moiety. Both functions of the fusion molecule, fibrin-specific binding and plasminogen activation, were fully preserved. In human plasma clots, thrombolysis by scFv(59D8)-scuPA(LMW) is significantly faster and more potent compared with the clinically used urokinase.

CONCLUSIONS

ScFv(59D8)-scuPA(LMW) constitutes a new recombinant chimeric plasminogen activator with a significantly enhanced thrombolytic potency and relative fibrin selectivity, that can be produced with modern methods at low cost, large quantities and reproducible activity in Escherichia coli.

CD44 Regulates Arteriogenesis in Mice and Is Differentially Expressed in Patients With Poor and Good Collateralization

Background— Arteriogenesis refers to the development of collateral conductance arteries and is orchestrated by circulating monocytes, which invade growing collateral arteries and act as suppliers of cytokines and growth factors. CD44 glycoproteins are involved in leukocyte extravasation but also in the regulation of growth factor activation, stability, and signaling. Here, we explored the role of CD44 during arteriogenesis.

Methods and Results— CD44 expression increases strongly during collateral artery growth in a murine hind-limb model of arteriogenesis. This CD44 expression is of great functional importance, because arteriogenesis is severely impaired in CD44 −/− mice (wild-type, 54.5±14.9% versus CD44 −/− , 24.1±9.2%, P <0.001). The defective arteriogenesis is accompanied by reduced leukocyte trafficking to sites of collateral artery growth (wild-type, 29±12% versus CD44 −/− , 18±7% CD11b-positive cells/square, P <0.01) and reduced expression of fibroblast growth factor-2 and platelet-derived growth factor-B protein. Finally, in patients with single-vessel coronary artery disease, the maximal expression of CD44 on activated monocytes is reduced in case of impaired collateral artery formation (poor collateralization, 1764±572 versus good collateralization, 2817±1029 AU, P <0.05).

Conclusions— For the first time, the pivotal role of CD44 during arteriogenesis is shown. The expression of CD44 increases during arteriogenesis, and the deficiency of CD44 severely impedes arteriogenesis. Maximal CD44 expression on isolated monocytes is decreased in patients with a poor collateralization compared with patients with a good collateralization.

Reversibility of increased formation of catecholamines in patients with alcoholic liver disease

BACKGROUND

While chronic alcohol abuse has been shown to be associated with increased production of catecholamines, little is known about the reversibility of this increased sympathetic activity and the influence of severity of alcoholic liver disease (ALD). The aim of the present study was to investigate whether the increase in urinary excretion rates and plasma levels of catecholamines in alcohol-abusing patients are reversible during prolonged abstinence, especially with respect to the severity of ALD.

METHODS

Urinary excretion rates and plasma levels of noradrenaline (NA), adrenaline (A) and dopamine (DA) were determined in 15 subjects with mild to moderate ALD (ALD1) and in 7 alcoholic cirrhotics (ALD2) on admission and after 2 and 12 weeks of abstinence. Eight healthy males, age-matched to ALD1, served as controls (HC).

RESULTS

Urinary excretion rates (24 h) and resting plasma concentrations of NA and A were increased in ALD1 and ALD2 about 2-fold, while those of DA were elevated only moderately compared to HC. During exercise under a load of 100 watts, the increases in plasma levels of NA and A with reference to the resting values were nearly identical in all three groups. Already after 2 weeks of abstinence, the urinary excretion rate of NA had nearly normalized in ALD1 but remained unchanged in ALD2.

CONCLUSION

The marked enhancement of catecholamine production, especially that of NA, observed in actively drinking alcoholics is reversible under abstinence within a few weeks in subjects with mild to moderate ALD but only partially reversible in alcoholic cirrhosis.

Collaborative Angiographic Patency Trial Of Recombinant Staphylokinase (CAPTORS II)

AIMS

A fibrinolytic agent more effective than streptokinase available for bolus injection with reasonable cost-effectiveness is a desirable goal. Pilot studies with bolus pegulated staphylokinase (PEG-Sak) have revealed excellent Thrombolysis In Myocardial Infarction (TIMI) 3 60-minute flow.

METHODS AND RESULTS

We evaluated patients with acute ST-elevation myocardial infarction within 6 hours of chest pain onset to determine a dose of PEG-Sak that had at least equal efficacy to recombinant tissue plasminogen activator (rt-PA) while maintaining an acceptable safety profile. After the initial study of 38 patients, of whom 27 received PEG-Sak, enrollment was temporarily halted because 3 patients receiving PEG-Sak had intracranial hemorrhage: 1 at a dose of 0.15 mg/kg and 2 at a dose of 0.05 mg/kg. Overall, 378 patients were studied across a PEG-Sak dose range from 0.01 mg/kg to 0.015 mg/kg, and 122 patients received accelerated rt-PA. At the lowest dose of PEG-Sak studied, 0.01 mg/kg, there was suggestive evidence of attenuation of efficacy; the point estimate for TIMI 3 flow was 24% (95% CI 9%-38%). At doses of 0.01875 to 0.0375 mg/kg (n = 314), TIMI 3 flow rates were 33% (95% CI 27%-38%), whereas the TIMI 3 flow was 41% (95% CI 20%-61%) at the highest PEG-Sak dose studied, 0.05 mg/kg (n = 23), which was similar to that found with rt-PA, 41% (95% CI 32%-50%).

CONCLUSION

The efficacy of PEG-Sak, coupled with its ease of administration, provide further impetus for further study in acute myocardial infarction.