RESUMEN
The conversion of singlet oxygen ((1)O2) to hydroxyl radical (*OH) during photosensitization of uroporphyrin (UP) in the presence of NADPH was examined by a spin-trapping technique with 5,5-dimethyl-1-pyrroline-N-oxide (DMPO). Significant electron spin resonance (ESR) signals of DMPO-OH adduct were observed during irradiation of the UP-NADPH system with visible light. Scavengers of *OH reduced the signal intensity to 3-30% of control, indicating that more than 70% of DMPO-OH results from freely diffusing *OH. The ESR signal was almost completely lost when quenchers of (1)O2 were added, and was enhanced when the amount of deutrated solvent was increased. The appearance of (1)O2, as determined by the oxidation of 2,2,6,6-tetramethyl-4-piperidone (TEMPD), was delayed with an increase in the concentration of NADPH, whereas the production of *OH was upregulated. These observations indicate that conversion of (1)O2 to *OH occurs quickly in the presence of NADPH. Hydrogen peroxide (H2O2) was produced (1)O2-dependently during irradiation of UP in the presence of NADPH. However, neither catalase nor desferrioxamine decreased the DMPO-OH signal, and addition of H2O2 did not increase the signal. SOD increased the signal only slightly. These results suggest that the production of *OH from (1)O2 involves neither superoxide anion radical nor H2O2.
Asunto(s)
Radical Hidroxilo/metabolismo , Luz , NADP/metabolismo , Oxígeno/metabolismo , Triacetonamina-N-Oxil/análogos & derivados , Uroporfirinas/metabolismo , Animales , Catalasa/metabolismo , Catalasa/farmacología , Bovinos , Deferoxamina/farmacología , Espectroscopía de Resonancia por Spin del Electrón , Bloqueadores Ganglionares/farmacología , Peróxido de Hidrógeno/farmacología , Modelos Químicos , Piperidonas/farmacología , Factores de Tiempo , Triacetonamina-N-Oxil/farmacología , Regulación hacia ArribaRESUMEN
The blood supply of the flexor pollicis longus tendon was investigated by arterial injections of india ink--latex-barium-solution in 15 fresh, adult cadaver upper extremities. In the digital area vascularity was by way of two vincula (V1 and V2). V1, located just proximal to the metacarpophalangeal joint and the A1 pulley, originated either from both digital arteries or from the princeps pollicis artery alone. V2, located at the interphalangeal joint level under the A2 pulley, originated from both digital arteries. In the predigital area branches of the median nerve artery supplied the area from the base of the thumb to the musculotendinous junction; in addition, the microvascular network of the mesotendon contributed to this area. Intratendinous vascularization was more abundant in the predigital area.
Asunto(s)
Arterias/anatomía & histología , Dedos/irrigación sanguínea , Tendones/irrigación sanguínea , Adulto , Cadáver , HumanosRESUMEN
Acute inflammatory responses to 10--0 Dexon and nylon were compared 2 weeks after experimental microvascular surgery in Sprague-Dawley rats. Statistical analysis revealed no significant differences, but the strength, long-term results, and minimal surrounding tissue reaction make Dexon a viable alternative to nylon. The main disadvantage of Dexon is its opaque blue-green color, which makes it nearly invisible in the operating field.
Asunto(s)
Microcirugia , Nylons , Ácido Poliglicólico , Suturas , Procedimientos Quirúrgicos Vasculares , Animales , Arteritis/inducido químicamente , Arteria Femoral/cirugía , Masculino , Nylons/efectos adversos , Ácido Poliglicólico/efectos adversos , Ratas , Ratas EndogámicasRESUMEN
1. Painless osteoid-osteoma is a very rare entity but must be considered. 2. Finger localization for this tumor has been reported in very few cases. Differential diagnosis with other tumors or osteomyelitis should be kept in mind. 3. Eng block excision in similar cases should be seriously considered. 4. While the reason for the absence of pain in some cases has not been precisely determined, the lack of nerve fibers in this case suggests that this may be an important factor.