18 research outputs found
The active site structure of the ba3 oxidase from Thermus thermophilus studied by resonance Raman spectroscopy
The active site structure of the ba3 oxidase from Thermus thermophilus studied by resonance Raman spectroscopy
The active site structure of ba(3) oxidase from Thermus thermophilus studied by resonance Raman spectroscopy
Chromophore-anion interactions in halorhodopsin from Natronobacterium pharaonis probed by time-resolved resonance Raman spectroscopy
Resonanz-Raman-spektroskopische Charakterisierung bakterieller Atmungskettenproteine
Available from TIB Hannover: RN 9087(110) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEDEGerman
A quantitative comparison of protoporphyrin IX pharmacokinetics and phototoxicity in human skin following iontophoretic delivery of the pro-drugs 5-aminolevulinic acid and 5-aminolevulinic-n-pentylester
Comparison of the pharmacokinetics and phototoxicity of protoporphyrin IX metabolised from 5-aminlevulinic acid and two derivatives in human skin in vivo.
Our novel approach was to compare the pharmacokinetics of 5-aminolevulinic acid (ALA), ALA-n-butyl and ALA-n-hexylester induced protoporphyrin IX (PpIX), together with the phototoxicity after photodynamic therapy (PDT) in human skin in vivo, using iontophoresis as a dose-control system. A series of four increasing doses of each compound was iontophoresed into healthy skin of 10 volunteers. The kinetics of PpIX metabolism (n = 4) and the response to PDT (n = 6) performed 5 h after iontophoresis, were assessed by surface PpIX fluorescence and post-irradiation erythema. Whilst ALA-induced PpIX peaked at 7.5 h, highest PpIX fluorescence induced by ALA-n-hexylester was observed at 3-6 h and no clear peak was seen with ALA-n-butylester. With ALA-n-hexylester, more PpIX was formed after 3 (P < 0.05) and 4.5 h, than with ALA or ALA-n-butylester. All compounds showed a linear correlation between logarithm of dose and PpIX fluorescence/phototoxicity at 5 h, with R-values ranging from 0.87 to 1. In addition, the ALA-n-hexylester showed the tendency to cause greater erythema than ALA and ALA-n-butylester. Fluorescence microscopy (n = 2) showed similar PpIX distributions and penetration depths for the three drugs, although both ALA esters led to a more homogeneous PpIX localization. Hence, ALA-n-hexylester appears to have slightly more favorable characteristics for PDT than ALA or ALA-n-butylester