[Embolic stroke of undetermined source (ESUS) : How much monitoring is necessary?] / ESUS ("embolic stroke of undetermined source") : Wie viel Monitoring ist nötig?

The clinical construct of embolic stroke of unknown source (ESUS) was first described in 2014. It is defined as cryptogenic ischemic stroke after the exclusion of a lacunar infarct, a significant (≥50%) stenosis of extracranial or intracranial arteries and a cardiac source of embolism. Initially, there was hope that these patients would benefit from anticoagulation. This was based on the suspicion that imaging criteria of stroke mimic features of embolism from cardiac sources or the great arteries. In two large randomized trials with 12,600 patients neither rivaroxaban nor dabigatran could reduce the risk of recurrent stroke. Based on these results, current research is focused on paroxysmal atrial fibrillation as a potential cause of stroke in these patients. Several randomized trials could show that by prolongation of monitoring to 30 days atrial fibrillation can be detected in approximately 10% of the patients. Using continuous monitoring (e. g. by implantable loop recorders) atrial fibrillation can even be detected in one quarter of the patients. Not all stroke patients can receive such an intensive monitoring. Therefore, this article summarizes the evidence and presents the resulting recommendations for patient selection and staged rhythm diagnostics and discusses a recently presented algorithm of an expert group for use in daily clinical practice.

Development of a Virosomal RSV Vaccine Containing 3D-PHAD® Adjuvant: Formulation, Composition, and Long-Term Stability.

PURPOSE: Characterization of virosomes, in late stage preclinical development as vaccines for Respiratory Syncytial Virus (RSV), with a membrane-incorporated synthetic monophosphoryl lipid A, 3D-PHAD® adjuvant. METHODS: Virosomes were initially formed by contacting a lipid film containing 3D-PHAD® with viral membranes solubilized with the short chain phospholipid DCPC, followed by dialysis, later by adding solubilized 3D-PHAD to viral membranes, or to preformed virosomes from DMSO. RESULTS: Virosomes formed from lipid films contained the membrane glycoproteins G and F, at similar F to G ratios but lower concentrations than in virus, and the added lipids, but only a fraction of the 3D-PHAD®. By single particle tracking (SPT), the virosome size distribution resembled that seen by cryo-electron microscopy, but dynamic light scattering showed much larger particles. These differences were caused by small virosome aggregates. Measured by SPT, virosomes were stable for 300 days. 3DPHAD ® incorporation in virosomes could be enhanced by providing the adjuvant from DCPC solubilized stock, but also by adding DMSO dissolved adjuvant to pre-formed virosomes. Virosomes with 0.1 mg/mg of 3D-PHAD®/viral protein from DMSO induced antibody titers similar to those by virosomes containing 0.2 mg/mg of DCPC-solubilized 3D-PHAD®. CONCLUSIONS: Stable 3D-PHAD® adjuvanted RSV virosomes can be formulated.

Membrane fusion. Anchors aweigh.

A recent study using a version of the influenza virus hemagglutinin protein in which its membrane anchor was replaced by a lipid tail provides new insights into how proteins can mediate the fusion of membranes.

Pores formed by influenza hemagglutinin.

Low pH-induced fusion mediated by the hemagglutinin (HA) of influenza virus involves a conformational change in the protein that leads to the insertion of a "fusion peptide" of the protein into the target membrane. It has been suggested that this insertion, aided by the formation of a complex of multiple HA trimers, would lead to perturbation of the bilayer structure of the membrane, initiating fusion. Here we present data showing that the interaction of the bromelain released ectodomain of the protein (BHA) with liposomal membranes at low pH leads to pore formation, at least at low temperatures. Strongly temperature-dependent low pH-induced inactivation of BHA resulted in a complete lack of activity of BHA above 10 degrees C. Even at 0 degrees C, only about 5% of the BHA participated in pore formation. Viral HA was less rapidly inactivated and still induced pores at 37 degrees C. BHA-induced pore formation showed a sigmoidal time course. Once BHA had formed a pore in one liposome, it did not form a pore in a further liposome. Quantitative analysis of pore formation indicated that one single BHA trimer sufficed to produce a pore. These data indicate that fusion peptide insertion perturbs the membrane and that the formation of a complex of trimers is not a prerequisite for the perturbation.

Gene transfer mediated by cationic lipids: lack of a correlation between lipid mixing and transfection.

Complexes of DNA with cationic lipids are used to transfect eukaryotic cells. The mechanism of transfection is unknown, but it has been suggested that the complexes are taken up into the cell by endocytosis, after which fusion of the cationic lipids with the membranes of intracellular vesicles would allow the DNA to escape into the cytoplasm. Here, we have compared transfection of CHO-K1 cells with lipid mixing measured by fluorescence assays, using liposomes or complexes with plasmid DNA of the cationic lipids 1,2 dioleolyl-3-N, N, N,-trimethylammonium-propane (DOTAP), N-[2,3-(dioleoyloxy)propyl]-N, N, N,-trimethylammonium (DOTMA), or combinations of these lipids with dioleoylphosphatidylethanolamine (DOPE), at various lipid/DNA charge ratios. Mixing of the lipids of the complexes or liposomes with cellular membranes occurred readily at 37 degrees C, and was more efficient with liposomes than with complexes. Lipid mixing was inhibited at low temperatures (0-17 degrees C), by the presence of NH(4)Cl in the medium, and by low extracellular pH, indicating the involvement of the endocytic pathway in entry. In the absence of DOPE, there was no correlation between the efficiency of lipid mixing and the efficiency of transfection. Moreover, although DOPE, which is thought to promote membrane fusion, enhanced transfection, it did not always enhance lipid mixing. Neither the size nor the zeta potential of the complexes were clearly associated with transfection efficiency. Therefore, although fusion between the lipids of the complexes and cellular membranes takes place, a step at a later stage in the transfection process determines the efficiency of transfection.

Fusion of influenza virus in an intracellular acidic compartment measured by fluorescence dequenching.

The fusion of influenza virus with cultured cells has been investigated. The virus was labelled with the fluorescent probe octadecyl rhodamine B and fusion was monitored as fluorescence dequenching due to dilution of the probe from the viral into a cellular target membrane. Fusion with the plasma membrane does not occur, unless the extracellular pH is temporarily lowered. At neutral pH fusion occurs only after a lag phase of 10-15 min, the time required for virus internalization, and the reaction is inhibited by NH4Cl, indicating that it takes place in an intracellular acidic compartment, most likely the endosome. This suggests that influenza virus infects cells via the endocytic pathway.

Clinical trials in coronary angiogenesis: issues, problems, consensus: An expert panel summary.

The rapid development of angiogenic growth factor therapy for patients with advanced ischemic heart disease over the last 5 years offers hope of a new treatment strategy based on generation of new blood supply in the diseased heart. However, as the field of therapeutic coronary angiogenesis is maturing from basic and preclinical investigations to clinical trials, many new and presently unresolved issues are coming into focus. These include in-depth understanding of the biology of angiogenesis, selection of appropriate patient populations for clinical trials, choice of therapeutic end points and means of their assessment, choice of therapeutic strategy (gene versus protein delivery), route of administration, and the side effect profile. The present article presents a summary statement of a panel of experts actively working in the field, convened by the Angiogenesis Foundation and the Angiogenesis Research Center during the 72nd meeting of the American Heart Association to define and achieve a consensus on the challenges facing development of therapeutic angiogenesis for coronary disease.

Influenza hemagglutinin mediated fusion of membranes containing poly(ethylene-glycol) grafted lipids: new insights into the fusion mechanism.

The influence of a hydrophilic layer covering the membrane on influenza hemagglutinin (HA) mediated fusion was investigated using membranes containing poly(ethylene-glycol) grafted phosphatidylethanolamine (PEG-2000-PE). Steric inhibition of HA-membrane interactions by these lipids affected virus fusion (half-maximal inhibition at 0.8 mol% for lipids with 114 ethylene glycol residues, or at 3.2 mol% for 45 residues (PEG-2000-PE), concentrations at which the PEG moieties adopt a random coil structure). Reconstituted viral membranes containing 3 mol% PEG-2000-PE retained 40% of their fusion activity. Therefore, efficient fusion is possible with membranes completely covered by a hydrophilic layer of several nanometers, and fusogenic virosomes containing PEG-PE are feasible.

Surgical treatment of double-outlet left ventricle in 2 patients with D-position and L-position of the aorta.

Two cases of double-outlet left ventricle (DOLV) are described, 1 with D-position and 1 with L-position of the aorta. Both patients had situs solitus, atrioventricular concordance with D-relationship of the two ventricles, a ventricular septal defect, and subpulmonary stenosis. The patient with D-position of the aorta was operated on using a technique similar to that for repair of Fallot's tetralogy but including emergency implantation of a bioprosthesis into the pulmonary artery position on the eighth postoperative day. Surgical correction in the patient with L-position of the aorta required the implantation of a composite valved conduit between the right ventricle and the pulmonary artery. The various surgical techniques for correction of DOLV are described, and the literature is reviewed. Postoperative right heart failure in both patients is explained by the impaired function of the right ventricle being exposed to gross pulmonary incompetence or by the persistence of elevated right ventricular pressure.

Complete correction of total anomalous pulmonary venous drainage: experience with 53 patients.

From January, 1973, to August, 1984, 53 infants with total anomalous pulmonary venous drainage (TAPVD) underwent a corrective operation in our unit. TAPVD was of the supracardiac type in 41% of the patients, cardiac in 17%, infracardiac in 36%, and mixed in 6%. Overall operative mortality was 23%; it was highest at 42% in the infracardiac group. Factors determining the outcome were the anatomical type of the lesion, the degree of pulmonary venous obstruction, the severity of pulmonary hypertension, and the young age of the patients. In addition, surgical experience appears to be an important factor in determining the outcome. During the study, hospital mortality decreased considerably to 11%. A corrective procedure offers the only chance of survival for patients with TAPVD. With some experience, excellent results can be obtained.

New approaches to coronary heart disease: induction of neovascularisation by growth factors.

Currently available approaches for treating human coronary heart disease aim to relieve symptoms and the risk of myocardial infarction by reducing myocardial oxygen demand (drugs), preventing further disease progression (drugs), restoring coronary blood flow either pharmacologically (thrombolysis) or mechanically (angioplasty), or bypassing the stenotic lesions and obstructed coronary artery segments (surgery). Direct gene therapy, as well as gene-derived therapy, especially by angiogenic growth factors, is emerging as a potential new treatment for cardiovascular disease. After extensive experimental research on angiogenic growth factors, the first clinical studies on patients with coronary heart disease or peripheral vascular lesions are being performed. The polypeptides fibroblast growth factor (FGF) and vascular endothelial growth factor seem to be effective in initiating neovascularisation (neo-angiogenesis) in hypoxic or ischaemic tissues. The first clinical study on patients with coronary heart disease treated by local injection of FGF-1 into the compromised underperfused myocardial tissue showed a 3-fold increase of capillary density mediated by the growth factor. Angiogenic therapy of the human myocardium introduces a new modality of treatment for coronary heart disease in terms of regulation of blood vessel growth. Beyond drug therapy, angioplasty and bypass surgery, this therapy may evolve to be a fourth principle of treatment of atherosclerotic cardiovascular disease.

Risks and benefits of cardiac pacing in children.

Forty-nine patients aged 2 days to 14 years (30% below 1 year of age) required implantation of a permanent pacemaker system. Surgically induced bradyarrhythmia was the main indication for treatment (84% of patients). In the follow-up period (ranging from 2 to 140 months) 16 reoperations became necessary for complications in 12 children. Twelve of these were caused by problems related to function of the epicardial electrode (threshold rise 9, lead fracture 2, dysfunction 1). Four patients died, but pacemaker function had remained intact in all. Our experience confirms that artificial cardiac stimulation has become a reliable instrument for improving quality of life and life expectancy of children endangered by postsurgical, congenital and acquired rhythm disorders.

[Peripheral venous DSA of the calf arteries in arterial obstructive disease patients. A comparison with conventional angiography]. / Periphervenöse DSA der Unterschenkelarterien bei AVK-Patienten. Vergleich mit der konventionellen Angiographie.

The ability of venous DSA to demonstrate the calf vessels distal to the trifurcation in patients with proximal blocks was compared with conventional angiography in 33 patients (44 limbs) in a study carried out by four observers. In 11.1% cases, the vessels were demonstrated better by DSA and in 2.5% by conventional angiography. In 86.4% the quality was the same. The reasons for this are analysed.

The stimulation of neoangiogenesis in the ischemic human heart by the growth factor FGF: first clinical results.

BACKGROUND: This paper is a report of our clinical experience with the human growth factor FGF as applied to the ischemic human myocardium. METHODS: After the completion of extensive preliminary animal experiments, the growth factor FGF, obtained from genetically manipulated E. coli bacteria and highly purified, was introduced into aortocoronary bypass surgery as an additional therapeutic agent. A double blind study was carried out on 40 patients with CHD, separated into "growth factor" and control groups, each containing 20 members. All the patients were treated for threefold vascular disease, in each case with an IMA bypass for the LAD and single venous bypasses for the RCX and/or RCA. In order to bridge over additional peripheral stenoses in the LAD or one of its branches, human growth factor FGF was injected into the myocardium of those in the growth factor group. Twelve weeks later, the IMA bypasses were selectively demonstrated by intraarterial DSA. These angiographs were then quantitatively evaluated. RESULTS: In all patients of the growth factor group, the formation of new vessels could be demonstrated in the region where FGF had been administered, in a manner strictly reminiscent of our experimental results. A capillary net sprouting from the coronary artery and making further connection with this vessel could be demonstrated, and the computer-supported evaluation of the angiographs showed a significant increase in the blood supply of the region of the myocardium injected. CONCLUSIONS: It is therefore our opinion that employment of the human growth factor FGF represents a useful extension to bypass surgery, particularly for patients with an additional peripheral stenosis that cannot be operatively revascularized.

The effect of enoximone and dobutamine on hemodynamic performance after open heart surgery. A clinical comparison.

In a prospective, randomized study the phosphodiesterase inhibitor enoximone was compared to dobutamine after open heart surgery. In either group 25 patients were treated with enoximone and dobutamine, respectively, beginning immediately after weaning from cardiopulmonary bypass until 4 hours postoperatively. The drug was administered as a continuous infusion of 5 micrograms/min/kg body weight. Under enoximone a significant increase of cardiac output [enoximone (E): + 100%; dobutamine (D): + 38%] and a significant decrease of pulmonary vascular resistance (E: -34%, D: +65%) and of total systemic vascular resistance (E: -59%, D: -7%) was achieved. Systemic blood pressure and heart rate were not different. Side effects were not observed. Enoximone proved to be safe and superior to dobutamine in low cardiac output states after open heart surgery.

Partial repair followed by total correction in congenital heart anomalies.

A two stage corrective operative approach is required for a variety of complex heart anomalies. Different anomalies require different approaches in the various age groups. The technique, results, and complications of elective primary partial repair followed by full correction are described.

[Traumatic shoulder dislocation. Late functional results with reference to the frequency of redislocation]. / Die traumatische Schulterluxation. Funktionelle Spätergebnisse unter Berücksichtigung der Reluxationshäufigkeit.

This study reports on the after-examination of 86 out of 107 patients with primary shoulder dislocation. Of greatest interest was the question which period of immobilisation would yield the best results. The most frequent type of dislocation was the subcoracoid position in 62% of all cases. In 44% the dislocations were associated with fractures especially of the greater tuberosity. The greatest number of dislocations occurred between 61 and 80 years of age (= 42%). The second highest number was found between 21 and 40 years of age (= 29%). In 47% of all cases the shoulder was immobilised for a week, in 40% between one and two weeks and in 13% for more than two weeks. The incidence of recurrence was 15% (13 patients). In 8 cases (= 9%) a recurrent dislocation of the shoulder resulted, whereas in 5 cases (= 6%) only one relapse occurred due to a repeated intense trauma. The function of the injured shoulder is most significantly impaired and rendered worse by the factors: higher age (greater than 41 years) and associated fractures. The duration of immobilisation itself has neither a significant influence on posttraumatic function of the shoulder nor on the incidence of recurrence. Therefore, an uncomplicated dislocation of the shoulder should be immobilised for a short period only. However, in cases of associated fractures, immobilisation will be necessary for a longer time.