ABSTRACT
The fluoroquinolone antibiotics are widely used despite their strong phototoxicity under solar UV irradiation. Although they are known as good photodynamic photosensitizers, other factors than production of activated oxygen species may play a role in the effectiveness of the phototoxic effect. Subcellular localization is one of the important parameters that may determine this strength. Using microspectrofluorometry, it is shown that norfloxacin, ofloxacin, lomefloxacin, ciproflaxin and BAYy3118 are readily incorporated into lysosomes of HS68 human skin fibroblasts although weak staining of the whole cytoplasm also occurs especially with norfloxacin. Consistent with their photoinstability in solutions, the fluoroquinolones under study are readily photobleached by UVA in the HS68 fibroblasts. The BAYy3118 derivative that has the fastest bleaching rate also shows the strongest phototoxicity toward HS68 fibroblasts. Photosensitization with these fluoroquinolones induces lysosomal membrane damage as shown by the increased rate of leakage of the lysosomal probe lucifer yellow as compared to that observed with untreated cells.
Subject(s)
Anti-Infective Agents/toxicity , Lysosomes/drug effects , Photosensitizing Agents/toxicity , Skin/drug effects , Anti-Infective Agents/metabolism , Cell Line , Fibroblasts/drug effects , Fibroblasts/metabolism , Fluorescent Dyes , Fluoroquinolones , Humans , Lysosomes/metabolism , Photobiology , Photosensitizing Agents/metabolism , Skin/metabolism , Ultraviolet Rays/adverse effectsABSTRACT
Ceramide-1-phosphate sugars were synthesized by direct glycosyl phosphite/phosphate and O-glycosyl trichloroacetimidate/phosphate exchange reactions, respectively. Thus, ceramide-1-O-phosphoric acid 5 gave with sialyl phosphite 1 as sialyl donor directly beta-linked sialyl phosphate 6; deprotection afforded the corresponding glycophospholipid ceramide-1-phosphate N-acetylneuraminate 7. Similarly, from O-glucosyl- and O-galactosyltrichloroacetimidate 10 and 13 with phosphoric acid derivative 5 glycosyl ceramide-1-phosphate sugars 12 and 15, respectively, were obtained.
Subject(s)
Carbohydrates/chemistry , Ceramides/chemistry , Phospholipids/chemistry , Magnetic Resonance SpectroscopyABSTRACT
As early as the beginning of this century, eyeglass lenses with aspherical surfaces were calculated at the behest of Gullstrand and M. von Rohr. There are considerable advantages in their use for the correction of hyperopic, aphakic, and myopic patients. The advantages lie not only in the better optical image produced by the lenses, but also in their lower weight and more pleasant appearance. The image quality of astigmatic lenses can be enhanced by means of atoric surfaces.
Subject(s)
Astigmatism/therapy , Eyeglasses , Optics and Photonics , Refractive Errors/therapy , Humans , Refraction, OcularABSTRACT
The previous magnifying spectacles and telescopic spectacles designed on the principle of the Galilean telescope have a magnification of only 2.5 x to 3 x for good image quality. New magnifying systems from Zeiss based on the Kepler telescope principle offer 3 x to 8 x magnification and thus cover the range between magnifying spectacles and operation microscopes and even come into the latter range. The following versions are available for ocular surgery: 1. Mounted on headband. 2. Fastened to the frame in front of the lenses. 3. Cemented into drilled holes in the lenses with additional horizontal connection of the magnifying systems. 4. Cemented into drilled holes in the lenses without horizontal connection. These versions offer different advantages and are selected according to the particular field of application and the refraction of the surgeon. With these compact and easily transportable stereomicroscopic systems the surgeon has complete freedom of movement being able to select the most convenient position at any stage of the examination or operation. Further applications of such stereomicroscopic spectacles beyond the field of ophthalmic surgery are mentioned.
Subject(s)
Eye Diseases/surgery , Microsurgery/instrumentation , HumansABSTRACT
A magnification system newly developed by Zeiss on the basis of a Keplerian telescope permits, in connection with a direct-vision erecting prism, the design of stereoscopic surgical spectacles and thus a break into the microsurgical range. The magnification of 8.3X is just about the limit up to which muscular movement of the head is not disturbing, but on the other hand routine microsurgery, especially cataract and glaucoma surgery, is rendered possible.
