Biomedical subjects

J G Worst

Publications and source records attributed to J G Worst.

At least 19 recordsLinked to original sources

PubMed1992

(An)aerobic bacteria found in secondary-cataract material. A SEM/TEM study.

Twenty four patients, who had marked reduction of vision due to secondary-cataract developed after an ECCE, were treated by surgical cleaning of the posterior lens capsule. During this procedure globular secondary-cataract material was removed and collected for morphological examination by SEM and TEM. Fragments of various sizes and shapes, including some with a 'golf ball' structure, were seen; these closely resembled particles frequently found in cataractous lenses. In addition, in 18 patients micro-organisms were found: rod-shaped bacteria, cocci, and in 2 cases yeasts. These findings were the more remarkable because these were clinically quiet eyes with no signs of intra-ocular inflammation and cultures have been persistently negative. We imagine that these bacteria must have entered the eye during the cataract extraction and have settled there without causing an infection.

Bacteria, Aerobic↗

PubMed1992

Study of the substructure of the Morgagni and Brunescens cataract with the TAO non-coating technique. Part 1: Morgagni cataract.

Lens tissue from a Morgagni cataract was examined by SEM and TEM. For SEM, after prefixation with glutaraldehyde and postfixation with the tannic acid/arginine/OsO4 non-coating (TAO) technique, and for TEM, after prefixation with glutaraldehyde, postfixation with OsO4/K4Fe(CN)6 and poststaining with uranyl acetate/lead citrate. The TAO technique seems to be a particularly suitable postfixation method for the SEM investigation of cataract tissue because of the presence of the protein structures present. The cortical region showed areas of radially, instead of concentrically, arranged lens fibres, degenerated lens fibres with holes (vacuoles), broken ball and socket connections between the lens fibres, and oval or spherical structures varying in size from 0.5-20 microns, the largest resembling a golfball, arising from the cytoplasm of degenerating lens fibres. The smallest, 0.2-0.5 microns, appear to have been expelled from the furrowed lens epithelium.

Cataract↗

PubMed1992

Study of the substructure of the Morgagni and Brunescens cataract with the TAO non-coating technique. Part 2: Brunescens cataract.

Lens tissue from a Brunescens cataract was prepared for SEM study by prefixation with glutaraldehyde and postfixation with the tannic acid/arginine/OsO4 combination; for TEM study the material was prefixed with glutaraldehyde, postfixed with OsO4/K4Fe(CN)6 and poststained with uranyl acetate/lead citrate. At low magnification, in contrast to the Morgagni cataract, no difference could be seen between the lens fibres in the cortical and nuclear areas. Morphologically, the destruction of the ball and socket system and the development of holes and spherical structures was striking. The latter appeared to have a thin coating and, after fracture, were either empty or showed remnants of material resembling membranes. In sections of the cataractous material, larger vacuoles containing smaller spheres were indistinctly visible.

Cataract↗

PubMed1992

Comparative anatomy of the vitreous body in rhesus monkeys and man.

In the isolated unfixed vitreous body a structural organization can be visualized by slitlamp microscopy or by an ink-injection technique. We discuss the observations on human and rhesus monkey (Macaca mulatta) vitreous bodies using the ink-injection technique. Advantages and disadvantages of this method compared with slitlamp microscopy are described. Eventual functional implications of vitreal organization are mentioned briefly.

Animals↗

PubMed1979