Biomedical subjects

M J Sagaties

Publications and source records attributed to M J Sagaties.

12 recordsLinked to original sources

PubMed1993

Three-dimensional evaluation of optic disc pallor in open angle glaucoma.

We evaluated the extent of pallor on the walls of the optic cup three-dimensionally using simultaneous stereophotographs of the optic discs of 29 normals, 29 ocular hypertensives and 28 primary open angle glaucomas. Pallor was located at the bottom of the optic cup. Pallor ascends the walls of the cup as its extent increases. Statistically significant differences in the extent of pallor in all four quadrants of the optic cup were observed, with the glaucomas having greater extents of pallor than ocular hypertensives, and the ocular hypertensives greater than the normals. The greatest percentage increase in mean pallor from normals to open angle glaucomas occurred on the nasal and inferior walls. This differential extent of pallor could be useful in characterizing ocular hypertension and chronic open angle glaucoma.

Adult↗

PubMed1989

Immunogold staining of elastin in the wall of the retinal arteries in Macaca mulatta.

Elastin has been demonstrated in the wall of the retinal arteries in or immediately adjacent to the optic disc of adult Macaca mulatta using the immunogold labelling technique with delta-elastin antibody. Since elastin is thought to provide elasticity to the walls of these vessels, perhaps its presence in the retinal arteries plays a role in contractility and regulation of blood flow throughout the retinal vascular system.

Animals↗

PubMed1987

Intercellular junctions between fibroblasts in connective tissues of the eye of macaque monkeys. A thin section and freeze fracture analysis.

Thin-section electron microscopy and freeze fracture were used in the analysis of the intercellular junctions between fibroblasts in connective tissues of the eye of Macaca mulatta, M. fascicularis, and M. arctoides. Fibroblasts located in the subconjunctival loose connective tissue, anterior sclera, scleral spur, iris stroma, ciliary body stroma, and posterior choroid were jointed by three kinds of junctions. Gap junctions were of different sizes and frequently composed of a small number of connexons organized in polygonal aggregates or linear arrays. Tight junctions were represented by isolated strands and never composed a continuous belt around the cells. Intermediate junctions were seen in thin sections but did not have any representation in the interior of the plasma membrane. It remains to be established whether, as is the case in other tissues, pathologic conditions of the eye are accompanied by some changes in the morphology and distribution of intercellular junctions between fibroblasts.

Animals↗

PubMed1987

The structural basis of the inner blood-retina barrier in the eye of Macaca mulatta.

This is a morphological analysis of the inner blood-retina barrier in various segments of the retinal vasculature in the eye of Macaque monkeys. The primary aims of this study are to identify the components of the walls of the arteries, central capillaries, peripheral capillaries and veins of the retina using light and electron microscopy, and to compare and contrast junctional morphology as revealed by thin section electron microscopy and freeze-fracture. The walls of these vascular segments are composed of continuous endothelium, muscle cells or pericytes, and connective tissue. Endothelial cells are joined by tight and gap junctions. In freeze-fracture replicas, tight junctions consist of a continuous, complex network of branching and anastomosing strands which do not possess free endings. The intramembrane strands of tight junction remain preferentially associated with the outer membrane leaflet or E-face of the endothelial plasma membrane and sit at the bottom of linear strands or grooves. However, particles and fragments of the intramembrane strands may be avulsed from the E-face during the fracture process and are associated with ridges on the inner membrane leaflet or P-face. The total number of plasmalemmal vesicles per unit area of endothelial cell for each vascular segment in thin sections is less than non-barrier endothelium, but greater than barrier endothelium. The paucity of plasmalemmal vesicles and the complexity of the tight junctional network contribute to the barrier function of the retinal vascular endothelium.

Animals↗

PubMed1983