Fibroma of tendon sheath located within the ankle joint capsule

We report a very rare case of fibroma of the tendon sheath arising from the anteromedial ankle joint capsule, with no apparent connection to any tendon in the area, found in a 58-year-old patient complaining of progressive local swelling. This uncommon tumor has its usual localization in tendon sheaths, is extremely rare in joint capsules, and has never been described in this location previously. MRI showed nonuniform low signal intensity in T1- and T2-weighted images and high intensity in STIR images. The mass was completely excised by open surgery. Histopathological analysis later confirmed the diagnosis of a fibroma of the tendon sheath

Photosensitized charge transfer and recombination of the ionic products in micellar solutions

The photoreactivity of the water soluble zinc derivative of meso-tetra-meta-N-methylpyridylporphine (ZnTmMPyP aqueous and micellar solutions. The electron transfer from the photoinduced triplet state of this molecule to ferric ion enables wusa sto indveetesrtmigianteed t hien molar extinction coefficient of the oxidized porphyrin The decay kinetcis of the P triplet in the presence of diheptylviologen or of a cobalt complex Co (edta) were measured at 460 nm. The formation and the decay of the oxidized porphyrin were measured at 700 nm. After the direct electron transfer in the bulk solution, the recombination kinetics of the reduced violoqen and P' are slowed down by a factor 27 in 3 x 10 cetyltrimethylammonium chloride (CTAC) solution. The recombination kinetics of Co (edta) and P were also slowed down in CTACmicelles. The interaction of the hydrophobic species and that of the negatively charged cobalt complex with the cationic micelle are considered responsible for this effect

PHOTOSENSITIZED FORMATION OF ASCORBATE RADICALS BY RIBOFLAVIN: AN ESR STUDY

Abstract— The riboflavin‐sensitized photooxidation of ascorbate ion (HA‐) to ascorbate radical (A‐) was followed by electron spin resonance (ESR) spectroscopy in conjunction with oxygen depletion measurements. In air‐saturated aqueous media, steady‐state amounts of A‐ are rapidly established upon irradiation. The ESR signal disappears within a few seconds after the light is extinguished–more slowly under constant irradiation as oxygen is depleted. No photooxidation was observed in deaerated media. Similar results were obtained with other flavins and when ascorbyl palmitate was substituted for HA‐. The effect of added superoxide dismutase, catalase, desferrioxamine, and singlet oxygen scavengers (NaN3 and tryptophan) was studied, as was replacement of water by D2O and saturation with O2. The results are indicative of ascorbate free radical production via direct reaction between ascorbate ion and triplet riboflavin in the presence of O2. While the presence of superoxide ion tends to reduce the steady‐state concentration of A‐, competition from the reaction of HA‐ with singlet oxygen is less apparent in this system (at HA‐≥ 1 mM) than in the previously studied aluminum phthalocyanine tetrasulfonate‐photosensitized reaction. Copyright © 1993, Wiley Blackwell. All rights reserve