[New possibilities of diagnostics and therapy of pericarditis]. / Neue Möglichkeiten der Diagnostik und Therapie der Perikarditis.

Pericarditis is an inflammatory disorder of the pericardium with or without an associated pericardial effusion. The diagnosis is based on the clinical manifestations and typical ECG changes. Echocardiography is essential to reveal the size of the pericardial effusion and to determine its hemodynamic significance. The precise etiology of pericarditis may be established by pericardiocentesis, pericardioscopy and targeted biopsy and consecutive pericardial fluid and biopsy analysis by molecular biology, cytology, microbiology and immunological techniques. Non steroidal anti-inflammatory drugs and/or colchicine are the mainstay of anti-inflammatory treatment of pericarditis. Systemic corticoid treatment should be restricted to patients with associated autoimmune disorder, relapsing pericarditis and as a complementary therapy in tuberculous pericarditis. In autoreactive pericarditis intrapericardial instillation of triamcinolone is effective with few side effects. In malignant pericarditis the intrapericardial administration of cisplatin prevents early recurrences.

[Clinical pathway "Acute Coronary Syndrome"]. / Behandlungspfad ,,Akutes Koronarsyndrom"

The clinical pathway "acute coronary syndrome" of the university hospital Marburg describes the guideline-conform and consented management of patients with ST-segment elevation infarct (STEMI), non-ST-segment elevation infarct (NSTEMI) and Troponin negative unstable angina. A 12-lead ECG recording is made and read in all patients within 10 minutes. All patients with STEMI undergo immediate revascularisation using primary percutanuous catheter intervention (PCI) after administration of basic medical therapy. Primary PCI is also used in all patients with NSTEMI, persistent chest pain, rhythm or hemodynamic instability. Patients with unstable angina, who became free of symptoms after application of basic medication, but who have additional risk factors undergo cardiac catheterisation within 48 hours. Acute myocardial infarction can be ruled out in patients with twofold negative cardiac troponin levels during 6-12 hours. In the absence of further symptoms, these patiens undergo differential diagnostic evaluation of cardiac and extracardiac causes of chest pain. The introduction of this clinical pathway 2 years ago, which was consented before by the hospital board and the clinical directors, has lead to a remarkable improvement in the clinical decision-making at the emergency room of the hospital and reduced the door to intervention time considerably.

Monitoring of plasmin and plasminogen activator activity in blood of patients under fibrinolytic treatment by reteplase.

There are no reliable data on plasmin or plasminogen activator (PA) activities in blood of patients receiving fibrinolytic treatment. This is due to continuing in vitro action of PA after blood withdrawal. These artefactual changes of PA or plasmin activities have been prevented by arginine stabilization of blood samples of myocardial infarction patients treated with plasminogen activators. Twelve patients with myocardial infarction were treated with reteplase 2 x 10,000,000 units in bolus application; one patient was treated with 100 mg t-PA in continuous infusion. Blood was immediately stabilized with EDTA and arginine. The plasma was analyzed with newly developed assays for plasmin and PA. Maximal plasmin activities in blood were obtained at 40 to 60 minutes reteplase treatment time (0.1-0.6 U/mL = approximately 0.05-0.3 micromol/L plasmin). The 50% clearance rate for plasmatic Pli was greater than 30 minutes. The plasmatic reteplase concentration peaked at approximately 2,000 U/mL after the first bolus infusion and at approximately 1,500-3,500 U/mL after the second bolus infusion. Reteplase was cleared to 50% within less than 30 minutes, also with great inter-individual variation. Arginine stabilization of blood allows reliable determinations of activities of plasmin and PA in blood of patients under fibrinolytic treatment: substantial plasmin activities occur in patients treated by reteplase. Therapeutic thrombolysis might be improved, imitating the physiologic cellular thrombolysis; i.e., polymorphonuclear phagocytes (PMN) that can be activated by singlet oxygen ((1)O(2)). PMN might be superior to PA in selective lysis of pathologic thrombi.

Functional determination of plasmin in arginine-stabilized plasma.

Reliable data on plasmin activities in blood of patients during fibrinolytic treatment are lacking. This is due to continuing plasminogen activation by plasminogen activators after blood withdrawal. The purpose of this study was to establish a new method for stabilization of blood and to detect plasmin activity in stabilized plasma. For optimization of plasma stabilization by arginine, 50 microL pooled normal citrated plasma was incubated with 50 microL of 0 to 1500 mM arginine, pH 8.7, and 25 microL 100 IU/mL u-PA, 1250 IU/mL t-PA, 10000 U/mL reteplase, 400 U/mL plasminogen-streptokinase-activator complex, 10 microg/mL tenecteplase in 6% BSA-PBS or 25 microL 25 microg/mL plasmin in 20% glycerol. Twenty-five microliters 3 mM HD-Val-Leu-Lys-pNA were added immediately (1 step) or after 90 minutes (room temperature [RT]). The same experiment was performed with pooled normal citrated plasma supplemented with 3.2 mg/mL EDTA, preoxidized with 0 mM or 20 mM chloramine-T for 10 minutes (37 degrees C). For optimization of plasmin activity, the oxidation time of the arginine-stabilized plasma sample containing 0.5 U/mL active plasmin and the chloramine-T amount was varied. Citrated plasma is stabilized against the in vitro action of all six plasminogen activators tested if the final arginine concentration is greater than 500 mM. Neither the addition of EDTA nor the addition of chloramine-T changes this plasma-stabilizing power of arginine. The optimized functional plasmin assay consists of incubation of 10 microL arginine-stabilized plasma with 10 microL 1.5 M arginine, pH 8.7, and 10 microL 100 mM CT in PBS. After 30 minutes (37 degrees C), 75 microL 1.2 M KCl, 1.6 M Arg, 0.75 mM Val-Leu-Lys-pNA (Stop-CS Reagent), and 175 microL 6% BSA-PBS are added and the absorbance increase (DeltaA) at 405 nm is determined. With the present arginine stabilization procedure of plasma and the determination of plasmin activity in arginine-stabilized plasma as described, it is feasible to determine the activity of plasmin in blood of patients receiving fibrinolytic treatment without artefactual in vitro changes in the samples.

In vitro simulation of therapeutic plasmatic fibrinolysis.

One type of therapy for thromboembolism is plasmatic thrombolysis. Several plasminogen activators (PA) are clinically available, including urokinase (u-PA), tissue plasminogen activator (t-PA), streptokinase (SK), plasminogen-streptokinase-activator-complex (PSAC), or mutants of t-PA such as reteplase (RP) or tenecteplase (TP). Therapeutic plasmatic fibrinolysis was simulated, using the PA at relevant plasma concentrations, and plasmin (Pli) and PA activities were determined. Normal citrated plasma was supplemented with 31 to 1,000 IU/mL u-PA, 0.31 to 20 microg/mL t-PA, 125 to 4,000 IU/mL SK, 12.5 to 400 U/mL PSAC, 125 to 4,000 U/mL RP, or 0.31 to 10 microg/mL TP. Ten IU/mL urokinase was also incubated with pooled plasma of stroke patients, that was previously oxidized with the singlet oxygen (1O2) donor chloramine T (CT), to destroy plasmatic PAI-1 and alpha2-antiplasmin. After 0 to 80 minutes (37 degrees C), 50-microL samples were withdrawn and added to 100 microL 1.5 M arginine, pH 8.7, and oxidized with 50 microL of 20 mM CT. For determination of plasmin activity, 10 microL thereof was incubated with 150 microL 1.5 M arginine, pH 8.7, and 100 microL 20 mM CT preoxidized (15 minutes 37 degrees C) pooled normal citrate buffered EDTA-plasma for 30 minutes (37 degrees C). For determination of [PA+Pli]-activity, arginine was added after this incubation. 25-microL 6 mM Val-Leu-Lys-pNA were added and deltaA/h at room temperature (RT) was monitored, using a microtiterplate reader. [PA+Pli]-Pli = PA. The PA concentration required to induce 25% [ED25] of the maximally inducible Pli-activity in plasma (= 1 U/mL = 45 mg/L = 0.53 micromol/L active Pli; deltaA = 363 +/- 8 mA/h RT) after 10 minutes (37 degrees C) were 320 IU/mL u-PA, 8 microg/mL t-PA, 140 U/mL PSAC, 6,000 IU/mL SK, 720 U/mL RP, and approximately 150 microg/mL TP. The approximate activity half-lives of the PA in plasma were 30 minutes for u-PA, 30 minutes for t-PA, greater than 80 minutes for SK, greater than 80 minutes for PSAC, 50 minutes for RP, and 80 minutes for TP. The present study shows--for the first time--a combined kinetic in vitro simulation of the plasmatic activity of six different PAs. At clinically used concentrations, RP induces the highest plasmatic Pli activity. Due to unselective generation of plasmin in plasma, all PA are of some danger in inducing severe hemorrhagias. Clinical thrombolysis might be improved by usage of more physiologic activators of thrombolysis, such as activators of polymorphonuclear neutrophils.

Dietary linolenic acid-mediated increase in vascular prostacyclin formation.

To define vascular effects of an enhanced dietary alpha-linolenic acid intake, 28 spontaneously hypertensive rats were fed a 3% sunflowerseed oil (44% linoleic acid) diet; in 3 groups (7 rats each), the diet was supplemented with 1, 2.5 or 5% linseed oil containing 62% alpha-linolenic acid. alpha-Linolenic acid was incorporated up to 12% in the aorta of the 5% linseed oil group. The eicosapentaenoic acid content was not significantly increased. The content of arachidonic acid and docosatetraenoic acid was moderately reduced in rats fed 5% linseed oil. The generation of 6-keto-PGF1 alpha (degradation product of prostacyclin) assessed by HPLC/electrochemical detection was, however, markedly increased (p < 0.05) in rats fed 2.5 and 5% linseed oil. The minor prostanoids TXB2, PGE2 and PGF2 alpha were not significantly altered. The high systolic and diastolic blood pressure of SHR monitored by radio telemetry was more effectively reduced (p < 0.05) in the light, i.e. sleep, cycle. An increased prostacyclin formation and lowered vascular arachidonic acid content associated with enhanced dietary alpha-linolenic acid intake would thus be expected to prove beneficial in the prevention of vascular disorders.

[Effect of nifedipine and nitroglycerin on epicardial vessels in coronary heart disease]. / Wirkung von Nifedipin und Nitroglycerin auf die epikardialen Leitungsgefässe bei koronarer Herzkrankheit.

The effect of nifedipine and nitroglycerin on the diameter of epicardial coronary arteries, the stenosis diameter, as well as arterial blood pressure and heart rate were recorded in 20 patients with coronary-heart disease. Nifedipine (20 mg sublingually) caused a significant fall in arterial pressure and a significant rise in heart rate. Additional administration of nitroglycerin (0.8 mg sublingually) caused a further fall in arterial pressure while heart rate remained constant. A definite relaxation (vasodilatation) of the epicardial vessels was demonstrated after nifedipine and a further increase after nitroglycerin. While nifedipine on average led to a significant increase in the diameter at the site of stenosis, response of individual stenoses was highly variable. In one patient with subtotal stenosis of the anterior interventricular branch a complete, transitory occlusion at the site of the stenosis occurred during nifedipine medication. This paradoxical reaction was not noted after nitroglycerin. Relaxation of the epicardial coronary arteries by nifedipine with suppression of phasic tone thus seems to be the major part of its anti-anginal effect. This effect is potentiated by nitroglycerin so that the combination of nitrate and calcium-antagonist appears to be therapeutically reasonable. In individual patients, however, there may be a paradoxical reaction to nifedipine.