8,897 research outputs found
The Phenion (R) Full-Thickness Skin Model for Percutaneous Absorption Testing
In recent years many efforts have been made to replace dermal toxicity testing of chemicals in the animal by in vitro assays. As a member of a German research consortium, we have previously contributed to the validation of an in vitro test protocol for percutaneous absorption studies on the basis of reconstructed human epidermis and both human and pig skin ex vivo. Aiming to assess the barrier properties of a newly developed reconstructed skin model, this protocol has now been transferred to the Phenion (R) Full-Thickness Skin Model (FT model). The permeation of testosterone and caffeine was quantified in parallel to that of pig skin using Franz-type diffusion cells. In addition, the permeation of benzoic acid and nicotine was studied. As expected, the FT model is more permeable than pig skin, yet its barrier properties are well in accordance with those of reconstructed human epidermis when compared to previous data. In fact, the FT model most efficiently retards testosterone as the compound of highest lipophilicity, which can be explained by an additional uptake by a reservoir formed by the dermis equivalent. Thus, the structure closely parallels human skin. In consequence, the Phenion FT model appears to be suitable for percutaneous absorption studies in hazard analysis and should be subjected to a catch-up validation study. Copyright (C) 2009 S. Karger AG, Base
Adding low-dose antidepressants to interferon alpha treatment for chronic hepatitis C improved psychiatric tolerability in a patient with schizoaffective psychosis
Treatment of chronic hepatitis C with interferon alpha (IFN-alpha) is relatively contraindicated in patients with psychiatric disorders because of possible severe psychiatric side effects. We report on a case of a female patient with a chronic schizoaffective psychosis, who was treated for 3 months with 3 x 3 mio IE IFN-alpha s.c./week because of a chronic hepatitis C (genotype Ib). Psychosis was stable with flupentixol monotherapy. After 2 months, she developed a severe depressive syndrome which lead to suicidal ideation. Until this time, she was without any antidepressive medication. Depressive symptoms disappeared after interferon therapy was stopped. Under prophylactic treatment with low-dose trimipramine (50 mg) or nefazodone (200 mg/day) therapy with IFN-alpha 3 x 3 mio IE/week was re-established after several months and again 2 years later adding ribavirin 1200 mg/day, a virustaticum. In contrast to the symptoms during monotherapy with IFN-alpha, during the time of both combination treatments, no psychiatric side effects occurred. While for ribavirin antidepressant effects are not known, we suppose that antidepressants may in serotonergic or noradrenergic caused by IFN-alpha. prevent changes neurotransmission caused by IFN-alpha. Copyright (C) 2000 S. Karger AG, Basel
Superdense Matter
We review recent work on the phase structure of QCD at very high baryon
density. We introduce the phenomenon of color superconductivity and discuss the
use of weak coupling methods. We study the phase structure as a function of the
number of flavors and their masses. We also introduce effective theories that
describe low energy excitations at high baryon density. Finally, we study the
possibility of kaon condensation at very large baryon density.Comment: 13 pages, talk at ICPAQGP, Jaipur, India, Nov. 26-30, 2001; to appear
in the proceeding
Head-on infall of two compact objects: Third post-Newtonian Energy Flux
Head-on infall of two compact objects with arbitrary mass ratio is
investigated using the multipolar post-Minkowskian approximation method. At the
third post-Newtonian order the energy flux, in addition to the instantaneous
contributions, also includes hereditary contributions consisting of the
gravitational-wave tails, tails-of-tails and the tail-squared terms. The
results are given both for infall from infinity and also for infall from a
finite distance. These analytical expressions should be useful for the
comparison with the high accuracy numerical relativity results within the limit
in which post-Newtonian approximations are valid.Comment: 25 pages, 2 figures, This version includes the changes appearing in
the Erratum published in Phys. Rev.
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