Showing papers by "Federal University of São Paulo published in 1989"

Mitochondrial DNA Deletions in Progressive External Ophthalmoplegia and Kearns-Sayre Syndrome

Abstract: We investigated the correlations of deletions of mitochondrial DNA in skeletal muscle with clinical manifestations of mitochondrial myopathies, a group of disorders defined either by biochemical abnormalities of mitochondria or by morphologic changes causing a ragged red appearance of the muscle fibers histochemically. We performed genomic Southern blot analysis of muscle mitochondrial DNA from 123 patients with different mitochondrial myopathies or encephalomyopathies. Deletions were found in the mitochondrial DNA of 32 patients, all of whom had progressive external ophthalmoplegia. Some patients had only ocular myopathy, whereas others had Kearns-Sayre syndrome, a multisystem disorder characterized by ophthalmoplegia, pigmentary retinopathy, heart block, and cerebellar ataxia. The deletions ranged in size from 1.3 to 7.6 kilobases and were mapped to different sites in the mitochondrial DNA, but an identical 4.9-kilobase deletion was found in the same location in 11 patients. Biochemical analysis showed decreased activities of NADH dehydrogenase, rotenone-sensitive NADH-cytochrome c reductase, succinate-cytochrome c reductase, and cytochrome c oxidase, four enzymes of the mitochondrial respiratory chain containing subunits encoded by mitochondrial DNA. We conclude that deletions of muscle mitochondrial DNA are associated with ophthalmoplegia and may result in impaired mitochondrial function. However, the precise relation between clinical and biochemical phenotypes and deletions remains to be defined.

Depressions of the Eyelids

Abstract: Based on the principle that the eyelids should exhibit a flat surface (Fig. 1.1), depressions of the eyelids can be considered defects in the appearance and just as undesirable as bulges. They are morphological alterations caused by a reduction in the volume of tissue, and thus are the opposite of bulges, where excess tissue exists. As we will show in this chapter, palpebral depressions can be a causative factor in scleral show and ectropion.

Bulges of the Skin, Fat, Muscle, and Bone Tissue

Abstract: Bulges in the eyelids, better known as baggy eyelids, can give a look of tiredness and/or aging to the face. They are very common occurrences and can exist at almost any age.

Contractile responses of the guinea-pig vas deferens to the combination of vanadium ions with ouabain.

Abstract: 1. 1. Vanadate and vanadyl ions (10 −5 –10 −2 M) induced dose-dependent rhythmic contractions of the vas deferens of reserpine-treated guinea-pigs. The Na, K-ATPase blocker ouabain (10 −5 –10 −3 M) induced similar, though smaller, effects. Experiments were performed to verify if these effects are due to an interaction with the same receptor population. 2. 2. Ouabain caused a striking potentiation of vanadium effects, which was also observed in denervated organs, indicating that a release of neuronal substances is not involved in potentiation. Similar potentiations were observed by combining vanadium with K-free solutions instead of ouabain, corroborating the involvement of the latter drug with Na, K, ATPase. 3. 3. From the analysis of time-response and concentration-response curves, there are at least three indications that vanadium and ouabain interact with different sites: (a) the combined effect of both agonists was several times higher than the corresponding isolated effects; (b) the combined effect, expected to be independent of the order of addition of the agonist, was higher if vanadium was added before, than after ouabain; (c) the combined effect depended on the time elapsed between the addition of the two agonists, being higher if an interval of at least 10 min was allowed between vanadium and ouabain additions. 4. 4. In conclusion, our results do not support the hypothesis that vanadium compounds and ouabain have a similar mechanism of action for the contraction induced in guinea-pig vas deferens.

Ectropions, Hematomas, and Other Complications

Abstract: In addition to the problems of scleral show (discussed in Chapter 2) and depressions (Chapter 4), there are other serious complications that can beset palpebral surgery: ectropions, hematomas, cicatricial retractions, palpebral asymmetries, exaggerated edemas, overprojection of fat grafts, milias, and others