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Antibodies against factor VIII occur in about 15-35% of hemophilia A patients and induce refractoriness to factor VIII substitution. In most cases, these antibodies are of the IgG class. Strategies to avoid or to treat such inhibitors are controversial. In very rare cases, factor VIII inhibitors also develop in nonhemophilic patients. Although there are anecdotal reports that these antibodies may disappear spontaneously without occurrence of bleeding tendencies, in the majority of patients the clinical course is characterized by severe hemorrhages. From 1980 to 1995, we observed ten nonhemophilic patients with acquired factor VIII inhibitors at our hospital. In most cases, a sudden bleeding tendency was observed shortly after an injury or surgery. Coagulation tests showed a prolonged aPTT and a decreased F VIII level. Other deficiencies of blood-clotting factors and acquired or hereditary von Willebrand's disease were excluded. Therapy with F VIII concentrates did not produce the expected increase. Measurement of F VIII inhibitor levels in Bethesda units/ml (BU/ml) revealed maximal values in the range of 2-128 BU/ml. Immunosuppressive therapy with azathioprine or cyclophosphamide in combination with methylprednisolone led to complete disappearance of the inhibitor, normalization of the coagulation tests, and complete remission of the bleeding tendency in seven treated patients within 6 weeks. Although the clinical course is not predictable and inhibitors may disappear spontaneously, combined therapy with methylprednisolone and azathioprine or cyclophosphamide is recommended for patients with bleeding tendency. In pregnancy, therapy should be started only with methylprednisolone; post-partum, azathioprine should be used additionally if methylprednisolone as a single drug does not lead to complete remission. In emergency situations, therapy with high doses of human factor VIII concentrate may be used. When bleeding does not cease, the additional use of activated prothrombin-complex concentrates or porcine factor VIII is indicated. Possible side effects may include hepatitis and short-lived intravascular thrombin production.

A comprehensive electron energy-loss spectroscopy study of niobium (Nb) and stable Nb-oxide phases (NbO, NbO2, Nb2O5) was carried out. In this work (Part I), the plasmons and energy-loss near-edge structures (ELNES) of all relevant Nb edges (Nb-N2,3, Nb-M4,5, Nb-M2,3, Nb-M1, and Nb-L2,3) up to energy losses of about 2600 eV and the O-K edge are analyzed with respect to achieving characteristic fingerprints of Nb in different formal oxidation states (0 for metallic Nb, +2 for NbO, +4 for NbO2, and +5 for Nb2O5). Chemical shifts of the Nb-N2,3, Nb-M4,5, Nb-M2,3, and Nb-L2,3 edges are extracted from the spectra that amount to about 4 eV as the oxidation state increases from 0 for Nb to +5 for Nb2O5. Four different microscopes, including a 200 keV ZEISS Libra with monochromator, were used. The corresponding wide range of experimental parameters with respect to the primary electron energy, convergence, and collection semi-angles as well as energy resolution allows an assessment of the influence of the experimental setup on the ELNES of the different edges. Finally, the intensity of the Nb-L2,3 white-line edges is correlated with niobium 4d-state occupancy in the different reference materials.

The first measurements of the opacity in a well characterized, hot, dense, laser-produced plasma are reported. Measurements of the absorption of x rays by l to 2 transitions in Alxit through Alviit have been made in a laser heated slab plasma at the measured temperature and density of 58+ 4 eV and 0.020 0.007 g/cm . The conditions in the plasma were determined to be reproducible, spatially uniform, and in nearly complete local thermodynamic equilibrium.The absorption spectra and the temperature-density data obtained provide an improved means for comparison with detailed atomic physics and opacity calculations.

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Under the influence of flosulide, a highly COX-2-selective inhibitor, we observed an antiproteinuric drug effect. The inflammation in PHN induced COX-2 protein expression that was not affected by low-dose flosulide. COX-1 and COX-2 protein expression was affected by high-dose flosulide, which therefore might lose its selectivity. High-dose flosulide induced a decrease in glomerular prostanoid production possibly because of COX-1 inhibition. Our results suggest that the therapeutic use of flosulide in proteinuria seems advantageous and deserves further studies because the basal prostaglandin levels remain unchanged in the low-dose-treated group, indicating that the compensatory capacity of prostaglandin production, which is essential for the regulation of renal hemodynamics, is maintained.

Results of a niobium absorption experiment are presented that represent a major step in the development of techniques necessary for the quantitative characterization of hot, dense matter. The general requirements for performing quantitative analyses of absorption spectra are discussed. Hydrodynamic simulations are used to illustrate the behavior of tamped x-ray-heated matter and to indicate potential two-dimensional problems inherent in the technique. The absorption spectrum of a low-Z material, in this case aluminum, mixed with niobium provides a temperature diagnostic, which together with radiography as a density diagnostic fully characterizes the sample. A discussion is presented of opacity calculations and a comparison to the measurements is given that illustrates the need for experiments to provide a critical test of theory. The experimental technique is placed in context with a review of previous measurements using absorption spectroscopy to probe hot, dense matter. It is shown that the overall experimental concepts, although understood, were not always achieved in previous experiments.

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