Invited article: Electric solar wind sail: toward test missions.

The electric solar wind sail (E-sail) is a space propulsion concept that uses the natural solar wind dynamic pressure for producing spacecraft thrust. In its baseline form, the E-sail consists of a number of long, thin, conducting, and centrifugally stretched tethers, which are kept in a high positive potential by an onboard electron gun. The concept gains its efficiency from the fact that the effective sail area, i.e., the potential structure of the tethers, can be millions of times larger than the physical area of the thin tethers wires, which offsets the fact that the dynamic pressure of the solar wind is very weak. Indeed, according to the most recent published estimates, an E-sail of 1 N thrust and 100 kg mass could be built in the rather near future, providing a revolutionary level of propulsive performance (specific acceleration) for travel in the solar system. Here we give a review of the ongoing technical development work of the E-sail, covering tether construction, overall mechanical design alternatives, guidance and navigation strategies, and dynamical and orbital simulations.

[Optimization of verification photographs in thoracic wall irradiations (so-called tangential field technique) in breast carcinoma. A short technical-methodical report]. / Optimierung von Verifikationsaufnahmen bei Thoraxwandbestrahlungen (sogenannte tangentiale Zangenfelder) beim Mammakarzinom. Kurze technisch-methodische Mitteilung.

When irradiating under high voltage condition, verification photographs prove to be difficult to take if the Gantry position is not aligned to 0 degree respectively 180 degrees, since the patient is being irradiated diagonally. Under these conditions it is extremely difficult to align the X-ray-cartridge vertically to the central beam of the therapeutic radiation. This results in, amongst others, misprojections, so that definite dimensions of portrayed organ structures become practical impossible to determine. This paper presented describes how we have solved these problems on our high voltage units (tele-gamma cobalt unit and linear-accelerator). By using simple accessories, determination of dimensions of organ structures, as shown on the verification photographs, are made possible. We illustrate our method by using the so-called tangential fields technique when irradiating mamma carcinoma.

[Pseudothrombosis of the inferior vena cava]. / Pseudothrombose der Vena cava inferior.

Flow phenomena can cause artifacts that may simulate thrombosis. The differentiation between thrombus and flow phenomenon can be made by delayed scans and certain CT-findings in thrombosis that may not be found in pseudothrombosis.

Effect of fibronectin on the haemolytic activity of complement.

Sheep erythrocytes were coupled with trinitophenyl sulphonate, sensitized with anti-TNP (or-DNP) IgM monoclonal antibodies, and exposed to components of the classical pathway of complement activation. When human fibronectin (FN) was added after C1q, but before addition of C1r and C1s (subunits of the first complement component), inhibition of haemolytic activity was observed which was strictly dependent upon the dose of FN. When FN was added after addition of C1 (reconstituted from C1q, C1r and C1s), the haemolytic activity of complement was not affected by the presence of FN. These data suggest that FN binds on C1q by interfering with C1r and C1s fixation. In addition, FN was unable to displace the activated subcomponents (C1r and C1s) from their binding site on C1q. When using other systems (sheep erythrocytes sensitized with anti-Forssman IgM monoclonal antibodies), the quantity of FN required to inhibit complement haemolytic activity was greater than in the TNP system. In normal plasma, there is a 50-fold excess of FN compared to free C1q.

[Acute course of Leigh syndrome with hypertrophic cardiomyopathy in a female infant]. / Akuter Verlauf des Leigh-Syndroms mit hypertropher Kardiomyopathie bei einem weiblichen Säugling.

A female infant already as a newborn progressively developed nutritional disturbances, metabolic acidosis, muscular hypotension and other neurologic changes, and on its 20th day of life suffered from an acute cardiac and respiratory insufficiency due to pericardial effusions causing cardiac tamponade. In spite of intensive care including mechanical ventilation the child died on the 58th day of life. Cardiac changes and cranial CT-scans are demonstrated. The characteristic symptomatology as well as blood chemistry led to the tentative diagnosis of Leigh's disease. Postmortem examination confirmed this diagnosis.

[Ormond's disease and chronic venous obstruction]. / Morbus Ormond und chronisch venöse Stauung.

Excretory urography has been one of the most helpful tools in diagnosis of retroperitoneal fibrosis (RPF). Ventro-medial deviation of the ureters at the level of lower lumbar spine with urinary obstruction and pointed clinical stenosis of the upper part of the ureters have been considered diagnostic of RPF. It can be easily forgotten that RPF can become clinically apparent as vascular disease. Various types of RPF appearances will be discussed in the light of two examples.

Mouse monoclonal antibodies at the red cell surface--I. Generation of EAC4 and interaction with C1.

C1 and C1 activity measurements were performed with EA and EAC4 prepared with rabbit anti-Forssman IgG or IgM and were compared to measurements with EA and EAC4 prepared with mouse monoclonal IgG2b and IgM anti-DNP antibodies on cells coupled with TNP: the amount of TNP per cell was optimal for antibody activity. No differences were found in the ability of EAC4 made with poly- or monoclonal IgM to measure C1 activity; in contrast, monoclonal IgM was capable of activating only about 30% of C1 when compared to activation by polyclonal IgM. Monoclonal vs polyclonal IgGs behaved in a similar manner but they were detecting only 50% of C1 or C1 activity when compared to IgM of the appropriate class. It was concluded that monoclonal antibodies were capable of generating EAC4 intermediate, and that the ability of monoclonal antibodies in the EAC4 complex to bind C1 and to detect C1 activity is not significantly different from that of polyclonal antibodies but that monoclonal antibodies are less efficient in activating C1 than polyclonal antibodies.

Mouse monoclonal antibodies at the red cell surface--II. Effect of hapten density on complement fixation and activation.

Complement (C)-dependent hemolytic dose-response curves of anti-TNP IgG2b and IgM monoclonal antibodies as a function of TNP density were analyzed: sheep red cells coupled with TNP served as targets. Under conditions when equal numbers of either IgG2b or IgM anti-TNP antibodies were taken up by cells with various TNP densities, both antibodies showed optimal activity at a hapten density of approximately 10(6) TNP/E with regard to C-mediated lysis. These results were similar to those obtained with polyclonal antibodies. The effectiveness of monoclonal antibodies in utilizing guinea pig or mouse C was also investigated. IgM anti-TNP monoclonal antibodies lysed E-TNP in the presence of guinea pig C, but failed to produce lysis in the presence of mouse C. Two monoclonal IgG1 (anti-TNP and anti-SRBC) and an IgG2a anti-TNP antibody failed to produce hemolysis in the presence of guinea pig and mouse C. IgG2b monoclonal antibodies, whether directed against TNP or Forssman antigen, activated guinea pig and, to a lesser extent, mouse C. Finally, monoclonal anti-TNP IgG3 antibodies exhibited a low but measurable hemolytic activity with guinea pig C (10-20 times below that of IgG2b).

[Perivesical varicosis and Ormond's disease]. / Perivesikale Varikose und M. Ormond.

Excretory urography has been the most important examination in retroperitoneal fibrosis (RPF). Medial deviation of the ureters at the level of the lower lumbar spine with hydronephrosis and dilatation of the upper part of the ureters have been considered diagnostic of RPF. Nowadays RPF can be easily recognized via CT studies, provided if appears as a mass. However, often CT studies do not detect PRF in spite of the presence of characteristic urographic changes and although RPF has been diagnosed microscopically. RPF involves the vascular system, too, and the visualization of compression or occlusion especially of the inferior vena cava or the iliac veins is also helpful in the diagnosis of RPF. In this paper we describe a case of RPF (diagnosis was confirmed histopathologically) with characteristic urographic changes, but no evidence of retroperitoneal mass. However, in this case RPF had led to a circumscribed phlebectasis of perivesical veins, which we demonstrated via CT and angiography.

[Preoperative radiologic diagnosis of renal angiomyolipoma. Significance of angiography and computerized tomography]. / Präoperative radiologische Diagnostik des renalen Angiomyolipoms. Bedeutung von Angiographie und Computertomographie.

The differential diagnosis of angiomyolipomas is an manifold as their angiographic appearances. The differentiation of this renal hamartoma from its most important differential diagnosis, carcinoma of the kidney, is possible only occasionally even when one includes epidemiological, clinical and angiographic findings, CT, in the other hand, provides certain pre-operative diagnosis in most cases by showing portions of the tumour of fat density. In any case, surgical treatment should be carried out, but the actual procedure will be significantly influenced. Demonstration of a benign space-occupying lesion allows one to plan a procedure which will preserve the kidney.

[Acute necrotising alcoholic pancreatitis with abscess formation in the mediastinum (author's transl)]. / Akute nekrotisierende Alkoholpankreatitis mit Abszedierung in das Mediastinum.

Pseudocysts, fistulae and abscesses are common complications of acute and acute-recurrent pancreatitis. Extension of necrosis and pseudocysts occur along anatomically determined structures. Extension of pancreatic necrosis into the mediastinum is rare. One such case is described. Possible mechanisms for the occurrence of acute and relapsing pancreatitis are discussed.