Browsing by Issue Date, starting with "1993"
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- Experimental studies on the mechanisms of tiaprofenic acid photosensitizationPublication . Figueiredo, A; Fontes-Ribeiro, CA; Gonçalo, Margarida; Poiares-Baptista, A; Teixeira, FRed blood cell lysis and histidine degradation, photosensitized by tiaprofenic acid (TIA), were investigated. Photohaemolysis was markedly enhanced in oxygenated solutions, but was also intense in the presence of nitrogen. Photohaemolysis was inhibited by butylated hydroxyanisole and reduced glutathione, but was unaffected by sodium azide, superoxide dismutase and mannitol. The TIA-induced photo-oxidation of histidine was greatly enhanced in the presence of oxygen and almost completely inhibited in solutions bubbled with nitrogen. Sodium azide, butylated hydroxyanisole and reduced glutathione inhibited the photodegradation of histidine. Phototoxicity to histidine was unaffected by mannitol and superoxide dismutase. The overall results suggest that molecular mechanisms involving free radicals and singlet oxygen are responsible for TIA-photosensitized reactions. These two in vitro models (photohaemolysis and histidine degradation) represent different mechanisms of phototoxicity, but complement one another in the investigation of potential phototoxic substances.
- Síndroma de Sjögren - estudo epidemiológico em adultos do concelho de CoimbraPublication . Filipe, C; Pinto, A; Spencer, A; Oliveira, L; Delgado, J; Proença, R; Ribeiro, H; Neto, J; Pedroso de Lima, J; Porto, A
- Envolvimento pulmonar subclínico em sarcoidose cutâneaPublication . Robalo-Cordeiro, C; Gonçalo, Margarida; Lima, MA; Mesquita, L; Teixeira, L; Santos-Rosa, M; Azevedo-Bernarda, R; Poiares-Baptista, A; Robalo-Codeiro, AJ
- Arteriovenous fistula with a saphenous long loopPublication . Patrício, J; Silveira, JAAfter radiation, chronic infection or previous operations recipient vessels for free tissue transfer become difficult to find. It may be necessary to locate vessels remote from the area of reconstruction and to construct long venous grafts. Long venous grafts can be compressed in the tissue tunnels that may be required. In this series of patients, an arteriovenous fistula was created with a long saphenous loop 10 to 21 days prior to tissue transfer. The saphenous loops were placed close to the area for reconstruction and when divided at the time of transplantation, provided one artery and one vein. In this series of 12 cases, adequate vascularization was achieved in 10 cases. In the other 2 cases, we believe that maturation of the fistula may have been necessary before proper function. The other advantages of the technique are: the procedure can be carried out under local anaesthesia, ease of positioning of the patient on the operating table, and a reduction in the time taken to perform the tissue transfer
- Testes epicutâneous com alcoóis da lanolina e amerchol L101 no estudo da sensibilidade à lanolinaPublication . Gonçalo, S; Gonçalo, Margarida
- Intramedullary cervical cavernous angiomaPublication . Barbosa, MD; Fernandes, R; Seabra-Santos, H
- Studies on the pathophysiology of diabetic retinopathy. The blood-retinal barrier in diabetesPublication . Cunha-Vaz, JGA review of the pathologic picture of diabetic retinopathy shows that available clinical methods of examination demonstrate the alteration of the blood-retinal barrier (leakage), microaneurysms, capillary closure, preferential channels, preretinal neovascularization and gross extravascular lesions. All of these changes may be shown by fluorescein angiography. The value of this method, however, is fundamentally related to the morphologic demonstration of these lesions and not their quantification. Quantitative evaluation of retinal involvement in diabetes is needed in order to delineate more clearly its natural history, criteria for prognosis, and effect of treatment. Vitreous fluorophotometry, a quantitative and sensitive method of evaluating the permeability of the blood-retinal barrier, has opened new perspectives for the evaluation of retinal involvement in diabetes. Vitreous fluorophotometry has shown that a disturbance of the blood-retinal barrier, possibly functional, appears in diabetic eyes before any lesion is clinically visible in the fundus, and that there is a close correlation between the severity of the vascular lesions and higher vitreous fluorophotometry readings. Recent studies also indicate an interesting correlation with metabolic control, particularly, glycosylated hemoglobin levels and insulin treatment. Finally, on the basis of these findings a working hypothesis for the pathogenesis of diabetic retinopathy is presented.
- Hemiplegia e amputação: avaliação funcionalPublication . Laíns, J; Azenha, A; Caldas, J
- Blood-retinal barrier permeability and its relation to progression of retinopathy in patients with type 2 diabetes. A four-year follow-up study.Publication . Cunha-Vaz, JG; Leite, E; Sousa, JC; Faria de Abreu, JRForty patients with late-onset diabetes (age at diagnosis 30 years or more) and minimal retinopathy as found by fundus photography were followed prospectively by repeated examination (baseline, 1 year, and 4 years). The study shows that early retinopathy changes are not permanent or invariably progressive. In the 1st year of follow-up microaneurysms worsened in 25%, improved in 10%, and remained stabilized in 65%. Vitreous fluorometry was able to detect an overall increase of 0.84 +/- 1.06 x 10(-6) min-1 in blood-retinal barrier (BRB) penetration ratios. After 4 years, 16 of the 40 patients had undergone photocoagulation (focal photo-coagulation in 11 and pan retinal photocoagulation in 5). The eyes that needed photocoagulation were the eyes that had higher fluorometry penetration ratios at the patient's entry into the study and showed a higher rate of deterioration during the 1st year of the study (5.54 +/- 1.97 vs 3.11 +/- 1.22 x 10(-6) min-1, P < 0.001, initial values; 1.52 +/- 0.76 vs 0.45 +/- 0.99 x 10(-6) min-1, P < 0.001, annual increase in leakage). The eyes that did not need photocoagulation, 24 out of 40, showed stable fluorometry readings within the 4-year period of follow-up (+0.02 +/- 0.98 10(-6) min-1). Abnormally high vitreous fluorometry values and their rapid increase over time appear to be good indicators of rapid progression and worsening of the retinopathy.
- Depressão e ansiedade na revaliazação do hemiplégico de causa vascularPublication . Laíns, J; Oliveira, RA; Caldas, J; Azenha, A; Keating, J