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Biomedical subjects

R F de Estable-Puig

Publications and source records attributed to R F de Estable-Puig.

At least 19 recordsLinked to original sources
PubMed1986

Leptomeningeal cysts after spot freezing: transmission and scanning electron microscopic observations.

The sequential development of the early phases of leptomeningeal cyst formation was studied in an experimental model. Light, transmission and scanning electron microscopic data were compared with those from human arachnoid cysts. Common features observed were: the participation of leptomeningeal cells in the structure of the cysts with exclusion of dural components; the absence of internal traversing trabeculae; the hyperplasia of leptomeningeal cells, particularly in the dome of the cysts. Other features of the experimental cysts were: the splitting of the pio-arachnoid membrane; the scarcity of collagen at the early stages; the presence of areas of mineralization at more advanced stages; the presence of remodeling parenchymal changes at the underlying nervous tissue.

Animals↗
PubMed1985

The fate of human umbilical vein grafts as an infrarenal aortic substitute in monkeys.

The literature contains conflicting reports about the potential value of the processed human umbilical vein graft as an arterial substitute. With a view to a better understanding of the ultimate fate of this device, a series of long-term implantation was undertaken with a nonhuman primate model. Dardik Biografts were implanted as an infrarenal aortic substitute in 13 monkeys. Nine were put to death following complications after post-operative periods ranging from 3 months to 3 years, while four animals remain alive. No calcification or lipid infiltration was found, presumably because the animals were healthy. The patency rate was poor because of complications associated with thrombotic deposits and thinning of the graft wall after implantation, which led to stenosis and fibrous hyperplasia along the anastomoses. The external polyester mesh was found to encourage external tissue proliferation, which could not prevent the graft from dilating since it contained neither elastin nor smooth muscle cells. Because the places where the graft had been damaged before or during processing were the sites of thrombotic accumulation and initial collagen degeneration, it is essential to use only defect-free material. As a consequence the long-term durability of this graft continues to be questioned.

Animals↗
PubMed1981

[Pathology of cerebral edema. I. Concept, etiopathogenesis and classification].

Taking into account its complex pathogenesis, we stress the inadequacy of considering brain edema as a single clinical or pathological entity. Vasogenic, cytotoxic and hydrocephalic varieties are considered. Some clinical conditions underlied by the common morphologic feature of "status spongiosus" are discussed. The methods of investigation of brain edema are presented as well as problems concerning its diffusion and resolution.

Blood-Brain Barrier↗
PubMed1981

[Pathology of cerebral edema. II. Experimental models and modifying agents].

Current experimental models of brain edema are described and evaluated for their contribution to the knowledge of basic processes involved in its production as well their contribution to the understanding of different clinical forms. The participation of each main pathogenic mechanism in a given experimental model is analyzed and proves to vary with each particular model and site studied. The importance of various experimental models in the evaluation of different therapeutic procedures directed to control the genesis and evolution of brain edema is stressed.

Animals↗
PubMed1979

[Ultrastructural semiology of lesions of striated muscle].

Basic changes of the striated muscle fiber are described after the electron microscopy study of 200 surgical muscle biopsies from the Montevideo Neurological Institute. The inventory of these changes--true ultrastructural "signs" of muscle derangement--is presented according to the involved organelle. The value of these data is considerably enhanced by a systematic approach to the study of a muscle biopsy that should begin with the in situ examination of the muscle territory before the excision of the tissue. A throroughful histopathological study and a careful screening of semithin sections previous to the selection of areas for E.M. are also of paramount importance. The description of individual fiber lesions and that of the topography of the lesions should be accompanied by the study of vessels. nerves and muscle spindles. We stress that most of the ultrastructural findings are nonspecific. They will however acquire diagnostic value and greater interest when grouped and related to the clinical data and to the results of other diagnostic methods, besides morphology.

Biopsy↗
PubMed1978

Metallic deposition in specimens presenting cavities using the sputter coater.

Local charging effects in small biological cavities during SEM observation are apparent, even after sputter coating. Using an experimental model, the thickness of metallic coating at the bottom of cylindrical cavities has been measured and found to be less than 50% the thickness on the surface, depending on the relation of diameter to depth of the cylinder.

Animals↗