Blocking phospholamban with VHH intrabodies enhances contractility and relaxation in heart failure.

The dysregulated physical interaction between two intracellular membrane proteins, the sarco/endoplasmic reticulum Ca ATPase and its reversible inhibitor phospholamban, induces heart failure by inhibiting calcium cycling. While phospholamban is a bona-fide therapeutic target, approaches to selectively inhibit this protein remain elusive. Here, we report the in vivo application of intracellular acting antibodies (intrabodies), derived from the variable domain of camelid heavy-chain antibodies, to modulate the function of phospholamban.

Phospholamban antisense oligonucleotides improve cardiac function in murine cardiomyopathy.

Heart failure (HF) is a major cause of morbidity and mortality worldwide, highlighting an urgent need for novel treatment options, despite recent improvements. Aberrant Ca handling is a key feature of HF pathophysiology. Restoring the Ca regulating machinery is an attractive therapeutic strategy supported by genetic and pharmacological proof of concept studies.

Ventilation via nose cone results in similar hemodynamic parameters and blood gas levels as endotracheal intubation during open chest surgery in rats.

Open chest surgery in rodents requires assisted breathing and the most common approach for ventilation is via an endotracheal tube. Even with well-trained operators the endotracheal intubation is technically challenging and may lead to prolonged procedures and endotracheal intubation complications. Nose cone ventilation is a simpler procedure compared to endotracheal intubation and has the potential to improve animal welfare by reducing procedure time and endotracheal intubation associated complications.

Recombinant human prothrombin (MEDI8111) combined with fibrinogen dose-dependently improved survival time and reduced blood loss in a porcine model of dilutional coagulopathy with uncontrolled bleeding.

: Uncontrolled bleeding due to trauma and coagulopathy is an area with high unmet medical need and high mortality rate. Treatment recommendations focus on transfusion of blood components while optimal therapy to improve coagulation remains to be established. The haemostatic effect of 2, 4 and 8 mg/kg recombinant prothrombin (MEDI8111) co-administered with 100 mg/kg fibrinogen (n = 7-8) was investigated in a porcine model of dilutional coagulopathy with uncontrolled bleeding.

Rapid Production of Human VEGF-A following Intradermal Injection of Modified VEGF-A mRNA Demonstrated by Cutaneous Microdialysis in the Rabbit and Pig .

Chemically modified mRNA is a novel, highly efficient, biocompatible modality for therapeutic protein expression that may overcome the challenges and safety concerns with current gene therapy strategies. We explored the efficiency of intradermally injected modified VEGF-A mRNA (VEGF-A mRNA) formulated in a biocompatible citrate/saline buffer to locally produce human VEGF-A protein. Rabbits (n=4) and minipigs (n=3) were implanted with subcutaneous microdialysis probes close to the injection sites and interstitial-fluid samples and skin biopsies were analysed for production of VEGF-A protein over time for up to 8 hours.

Accurate measurement of endogenous adenosine in human blood.

Accurate determination of in vivo circulating concentrations of extracellular adenosine in blood samples is challenging due to the rapid formation and rapid clearance of adenosine in blood. A blood collection protocol was developed based on direct sampling of venous blood into, and instant mixing with, a STOP solution developed to conserve in vivo adenosine concentrations by completely preventing both its formation and clearance in collected blood. Stable isotope labeled AMP and adenosine spiked into blood ex vivo were used in combination with mass spectrometry to evaluate conservation of adenosine and prevention of its formation.

Quantification of unbound concentration of ticagrelor in plasma as a proof of mechanism biomarker of the reversal agent, MEDI2452.

Ticagrelor, a P2Y12 antagonist, is approved for prevention of thromboembolic events. MEDI2452 is a potential reversal agent for ticagrelor and ticagrelor active metabolite (TAM). The total plasma exposure of ticagrelor and TAM in patients are roughly 0.

Hemostatic effects of the ticagrelor antidote MEDI2452 in pigs treated with ticagrelor on a background of aspirin.

Unlabelled: Essentials MEDI2452 is a specific antidote of the platelet P2Y receptor antagonist ticagrelor. Hemostatic effects of MEDI2452 were evaluated in pigs treated with ticagrelor and aspirin. MEDI2452 eliminated free ticagrelor within 5 min and gradually normalized platelet aggregation.

Boosting the coagulation restores haemostasis in ticagrelor-treated mice.

Antiplatelet therapy is given to patients with acute coronary syndrome to reduce the risk for thrombotic events, but may increase the risk for bleeding. Ticagrelor was administered intravenously to mice. Cumulative blood loss and bleeding time were measured after cutting 5 mm of the tail, 20 min after the start of ticagrelor infusion.

Unraveling the pharmacokinetic interaction of ticagrelor and MEDI2452 (Ticagrelor antidote) by mathematical modeling.

The investigational ticagrelor-neutralizing antibody fragment, MEDI2452, is developed to rapidly and specifically reverse the antiplatelet effects of ticagrelor. However, the dynamic interaction of ticagrelor, the ticagrelor active metabolite (TAM), and MEDI2452, makes pharmacokinetic (PK) analysis nontrivial and mathematical modeling becomes essential to unravel the complex behavior of this system. We propose a mechanistic PK model, including a special observation model for post-sampling equilibration, which is validated and refined using mouse in vivo data from four studies of combined ticagrelor-MEDI2452 treatment.

Structural and functional characterization of a specific antidote for ticagrelor.

Ticagrelor is a direct-acting reversibly binding P2Y12 antagonist and is widely used as an antiplatelet therapy for the prevention of cardiovascular events in acute coronary syndrome patients. However, antiplatelet therapy can be associated with an increased risk of bleeding. Here, we present data on the identification and the in vitro and in vivo pharmacology of an antigen-binding fragment (Fab) antidote for ticagrelor.

Evaluation of AR-H067637, the active metabolite of the new direct thrombin inhibitor AZD0837, in models of venous and arterial thrombosis and bleeding in anaesthetised rats.

AZD0837, currently in clinical development, is a once-daily oral anticoagulant that is bioconverted to AR-H067637, a selective, reversible direct thrombin inhibitor (DTI). When developing a new DTI, the antithrombotic effects are commonly investigated in in vivo animal models; this report shows the effect of AR-H067637 in venous and arterial thrombosis and bleeding models in anaesthetised rats. Thrombus formation was induced by topical application of ferric chloride to the carotid artery or to the caval vein with partial stasis.

Cancer risk of patients with ischaemic syndromes.

Introduction: Angiogenesis constitutes the regulation of collateral formation in subjects with ischaemic syndromes and is also a prerequisite for cancer progression. Patients with severe symptomatic ischaemic syndromes may have a reduced ability for angiogenesis and thus a lower risk to develop cancer.

Subjects And Methods: Patients below 80 years and treated for acute myocardial infarction (AMI), angina pectoris (AP), intermittent claudication (IC) or undergoing revascularization during 1972-1991 in Stockholm county (n=63 921) were followed regarding cancer incidence 1972-2000.

Early results of a new mechanical tri-leaflet heart valve prosthesis--"Tricusp": an animal study.

Objective: A new tri-leaflet mechanical heart valve made of titanium was inserted in the mitral position to evaluate early results.

Methods And Results: Five sheep were followed between 3 and 6 months (mean 4.7 months) and performed very well clinically during the follow-up period.

Determination of cardiac involvement in sarcoidosis by magnetic resonance imaging and Doppler echocardiography.

Objectives: To elucidate whether cardiac magnetic resonance imaging (MRI) could be useful in disclosing structural changes in the myocardium in sarcoidosis patients and to relate echo-Doppler derived indices of left ventricular function to electrocardiogram (ECG) findings.

Design: The MRI was performed in 18 consecutive patients with sarcoidosis. Left ventricular ejection fraction (LVEF), i.

Chronic cobalt exposure affects antioxidants and ATP production in rat myocardium.

Chronic cobalt exposure is characterized by severe cardiac insufficiency. Since the mechanisms of cobalt toxicity are not yet clear, we analysed the effects of chronic cobalt exposure on antioxidant enzyme activities and myocardial mitochondrial ATP production rate in a rat model. One group of rats was fed a conventional diet and another a cobalt supplemented diet for 24 weeks.

ECG-abnormalities in Japanese and Swedish patients with sarcoidosis. A comparison.

Background And Aim Of The Work: ECG abnormalities are more common in patients with sarcoidosis than in controls. The incidence of cardiac sarcoid granulomas in the Japanese population has been found to be higher than that seen in Caucasians. We compared the prevalence of ECG abnormalities in Japanese and Swedish patients with sarcoidosis.

Monotherapy with amlodipine or atenolol versus their combination in stable angina pectoris.

Background: The basic cause of angina pectoris is imbalance between the metabolic needs of the myocardium and the capacity of the coronary circulation to deliver sufficient oxygenated blood to satisfy these needs.

Hypothesis: The study was undertaken to evaluate whether the effect of combined amlodipine and atenolol therapy on patients with stable angina pectoris and with ST-depression during exercise testing and 48-h ambulatory electrocardiographic monitoring is superior to that of either agent given alone.

Methods: Patients with stable angina pectoris and ST depression during exercise and ambulatory monitoring were randomized to receive amlodipine (n = 116) or atenolol (n = 116), or both (n = 119).

Myocardial morphology and cardiac function in rats with renal failure.

The effects of chronic renal failure on cardiac performance and myocardial morphology were studied in rats: 17 with 5/6 nephrectomy (CRF rats) and 12 with sham operation (controls). Cardiac function was assessed 8 weeks postoperatively, using the Langendorff technique for an isolated working heart model. After the hemodynamic study the hearts were fixed for electron and light microscopy.

Effects of melagatran, a new low-molecular-weight thrombin inhibitor, on thrombin and fibrinolytic enzymes.

Melagatran, a new, competitive and rapid inhibitor of thrombin with a molecular mass of 429 Da is described. Melagatran is well tolerated when administered in very high doses, and the oral bioavailability in the dog is relatively high. The aim of the study was to determine, in the preclinical setting, the degree of selectivity against the fibrinolytic system required for entering the clinical development phase.

In vitro flow dynamics of a new mechanical cardiac valve prosthesis--"tricusp".

The hydrodynamic performance of a newly developed JCL-trileaflet mechanical heart valve prostheses (Tricusp) was measured and compared with some of the currently most used heart valve prostheses types. All experiments were performed in an electrohydraulic, computer-controlled pulse duplicator simulating the left side of the human circulatory system. Testing conditions were set according to a Food and Drugs Administration interlaboratory comparison protocol, with cardiac outputs 3.

Progressive decline in renal function induces a gradual decrease in total hemoglobin and exercise capacity.

We examined 58 patients (38 men, 20 women; mean age: 45 +/- 12 years; body mass index: 24 +/- 4 kg/m2) with a glomerular filtration rate (GFR) ranging from 3 to 32 ml/min, in order to determine the effects of a progressive decline in renal function on total hemoglobin (THb) and exercise capacity. The THb ranged from 185 to 759 g and the hemoglobin concentration ranged from 66 to 151 g/l. Maximal exercise capacity ranged from 50 to 260 W (40-143% of the expected norm).

Acute cobalt exposure and oxygen radical scavengers in the rat myocardium.

Excessive amounts of cobalt are cardiotoxic, although the mechanism for this toxicity remains unclear. We studied the effects of acute cobalt exposure on the activities of free radical scavengers in the myocardium in 5 groups of rats. Six rats served as a control group and were given a daily subcutaneous injection of 1 ml saline for 8 days.

Effects of renal failure on skeletal muscle.

In this cross-sectional study, we examined biopsies from the vastus lateralis muscle of 13 predialytic uremic men (mean age 46 +/- 8 years). Their average glomerular filtration rate was 14 +/- 7 ml/min x 1.73 m2 and their maximal exercise capacity, measured by standardized exercise test on a bicycle ergometer, was 184 +/- 45 W (94% of the expected norm).

The hemodynamic importance of atrial systole: a function of the kinetic energy of blood flow?

The relative importance of atrial systole on left ventricular filling was investigated at rest and during exercise in 25 patients with dual chamber pacemakers. The mean blood flow velocity over the mitral valve, the velocities of the rapid filling phase (E), the active filling phase (A), and the E/A ratio were determined by pulsed Doppler-echocardiography. The patients were first examined at rest during AV sequential pacing (DVI) at 70 and 104 beats/min.