Mediators of leukocyte yctivation play a role in disseminated intravascular coagulation during orthotopic liver transplantation

Leukocytes play an important role in the development of disseminated intravascular coagulation (DIC). In the reperfusion phase of OLT a DIC-like situation has been described and has been held responsible for the high blood loss during this phase. We investigated the role of leukocytes in the pathogenesis of DIC in OLT by measuring the leukocytic mediators released upon activation (cathepsin B, elastase, TNF, neopterin) and the levels of thrombin-antithrombin III (TAT) complexes, seen as markers of prothrombin activation. Arterial blood samples were taken at 10 different time points during and after OLT. Samples were also taken of the perfusate released from the liver graft vein during the flushing procedure before the reperfusion phase. Aprotinin was given as a continuous infusion (0.2-0.4 Mill. KlU/hr) and its plasma levels were determined. Significantly elevated levels of neopterin (15-fold; P<0.01), cathepsin B (440-fold; P<0.01) in the perfusate, as compared with the systemic circulation, as well as their significant increases in the early reperfusion phase suggested that they were released by the graft liver. This was paralleled by elevated levels of elastase (1.3-fold, P<0.05), TNF (1.5-fold, P=NS), and TAT complexes (1.4-fold; P<0.1) in the perfusate. Significant correlations could be identified between the parameters of leukocyte activation and TAT complexes, whereas no correlation was observed between any of the parameters investigated and the aprotinin levels. Our results strongly indicate a release of leukocytic mediators from the graft liver during its reperfusion which seems to be related to the parallely increased prothrombin activation. No correlation could be seen between levels of aprotinin and levels of leukocytic mediators

Phase-sensitive detection of Bragg scattering at 1D optical lattices

We report on the observation of Bragg scattering at 1D atomic lattices. Cold atoms are confined by optical dipole forces at the antinodes of a standing wave generated by the two counter-propagating modes of a laser-driven high-finesse ring cavity. By heterodyning the Bragg-scattered light with a reference beam, we obtain detailed information on phase shifts imparted by the Bragg scattering process. Being deep in the Lamb-Dicke regime, the scattered light is not broadened by the motion of individual atoms. In contrast, we have detected signatures of global translatory motion of the atomic grating.Comment: 4 pages, 4 figure

Ultra-cold atoms in an optical cavity: two-mode laser locking to the cavity avoiding radiation pressure

The combination of ultra-cold atomic clouds with the light fields of optical cavities provides a powerful model system for the development of new types of laser cooling and for studying cooperative phenomena. These experiments critically depend on the precise tuning of an incident pump laser with respect to a cavity resonance. Here, we present a simple and reliable experimental tuning scheme based on a two-mode laser spectrometer. The scheme uses a first laser for probing higher-order transversal modes of the cavity having an intensity minimum near the cavity's optical axis, where the atoms are confined by a magnetic trap. In this way the cavity resonance is observed without exposing the atoms to unwanted radiation pressure. A second laser, which is phase-locked to the first one and tuned close to a fundamental cavity mode drives the coherent atom-field dynamics.Comment: 7 pages, 7 figure

Different aprotinin applications influencing hemostatic chances in orthotopic liver transplantation

The effect of different aprotinin applications on hemmtatic changes and blood product requirements in orthotopic liver transplantation was investigated in a prospective, open, and randomized study. From November 1989 to June 1990, 13 patients received aprotinin as a bolus of 0.5 Mill, kallikrein inac-tivator units (KIU) on three occasions in the course of an OLT, whereas 10 other patients were treated with continuous aprotinin infusion of 0.1-0.4 Mill. KIU/hr. Before and after reperfusion of the graft liver, signs of hyperfibrinolysis, measured by thrombelastography, were significantly lower in the infusion group. Tissue-type plasminogen activator (t-PA) activity increased during the anhepatic phase but to a significantly lesser extent in the infusion group. Blood product requirements during OLT were tendentiously higher in the bolus group but not significantly so. However, the use of packed red blood cells was significantly lower in the postoperative period, whereas there was no significant difference in fresh frozen plasma requirements between the two groups. All 23 patients have survived, and only one woman of each group required retransplantation due to severe host-versus-graft reactions. Furthermore, we investigated the perfusate of the graft liver in both groups and detected signs of a decreased t-PA release in the infusion group. Our results demonstrate an advantage of aprotinin given as continuous infusion over bolus application in OLT

Ensemble of Hankel Matrices for Face Emotion Recognition

In this paper, a face emotion is considered as the result of the composition of multiple concurrent signals, each corresponding to the movements of a specific facial muscle. These concurrent signals are represented by means of a set of multi-scale appearance features that might be correlated with one or more concurrent signals. The extraction of these appearance features from a sequence of face images yields to a set of time series. This paper proposes to use the dynamics regulating each appearance feature time series to recognize among different face emotions. To this purpose, an ensemble of Hankel matrices corresponding to the extracted time series is used for emotion classification within a framework that combines nearest neighbor and a majority vote schema. Experimental results on a public available dataset shows that the adopted representation is promising and yields state-of-the-art accuracy in emotion classification.Comment: Paper to appear in Proc. of ICIAP 2015. arXiv admin note: text overlap with arXiv:1506.0500

Dimensional Crossover in Bragg Scattering from an Optical Lattice

We study Bragg scattering at 1D optical lattices. Cold atoms are confined by the optical dipole force at the antinodes of a standing wave generated inside a laser-driven high-finesse cavity. The atoms arrange themselves into a chain of pancake-shaped layers located at the antinodes of the standing wave. Laser light incident on this chain is partially Bragg-reflected. We observe an angular dependence of this Bragg reflection which is different to what is known from crystalline solids. In solids the scattering layers can be taken to be infinitely spread (3D limit). This is not generally true for an optical lattice consistent of a 1D linear chain of point-like scattering sites. By an explicit structure factor calculation we derive a generalized Bragg condition, which is valid in the intermediate regime. This enables us to determine the aspect ratio of the atomic lattice from the angular dependance of the Bragg scattered light.Comment: 4 pages, 5 figure