Biomedical subjects

W L Jongebloed

Publications and source records attributed to W L Jongebloed.

95 records · Page 6Linked to original sources

PubMedDate not supplied

Stainless steel as suturing material in human- and rabbit corneas: a SEM-study.

Stainless steel wire, dia. 50 microns, was used as suturing material in rabbit corneas for periods of 1.5, 3 and 7 months respectively, in order to test its inertness and acceptance by the corneal tissue. One clinical case of stainless steel wire used for fixation of an I.O.L.-implantation, after a 5-year residence in the eye, is reported as well. After 1.5 months' residence, the suture margins were well covered with tissue containing irregularly shaped endothelial cells, some fibroblastic-type cells and various kinds of collagenous fibre material. The buckled surface was partly covered with a very thin membrane of collagenous material, strands of collagenous fibres and a few fibroblastic-type cells. After 3 months' residence the buckle was almost completely covered with an endothelial cell layer. The individual cells had a somewhat irregular hexagonal shape. At a few local sites closure was still progressing, with filopodia and other collagenous matter generated by neighbouring cells on top of previously deposited Descemet's membrane. After 7 months' residence, the buckle was completely covered with normal endothelium. The fixation suture in the human case showed perfect acceptance by the corneal tissue.

Animals↗

PubMedDate not supplied

Some aspects of cataract morphology: a SEM-study.

Two lenses from patients of very advanced age with senile cataracts were processed for SEM, fractured equatorially, sputtered with Au and examined by SEM. In the cross-fracture various areas could be observed. Although the overall structure of the lens-fibres appeared to be intact, higher magnifications showed that the len-fibre material had changed into a brittle structure, with either a granular appearance or a fibrillar character. At other places clearly recrystallization of lens-fibre proteins had taken place, with the formation of finger-like substructures, sometimes organized into plate-like structures or running parallel to each other in a kind of undulating pattern. Between the various areas of chemically changed lens-fibre material certain 'canal-like' areas were found with cellular structures, the so-called 'waterclefts' or 'Wasserspalten'. Structures which, together with the chemical change in the lens proteins, account for the dramatic change in light dispersion.

Aged↗

PubMedDate not supplied

Soemmering's ring, an aspect of secondary cataract: a morphological description by SEM.

A Soemmering's ring attached to a patient's I.O.L. was removed and processed for SEM-examination. The enveloping structure of the Soemmering's ring was clearly of capsular origin, adherent along a single line and forming an envelope around the inner material. The envelope had a membranous character. The contents of the ring varied from the outside to the centre. Close to the capsule envelope a more or less amorphous material was found. Most of the contents of the ring was made up of lens-fibre material. Sometimes clear lens fibres were visible with densely packed lens-fibre proteins, sometimes with clusters of recrystallized proteins, rod-shaped or spherical, surrounded by what appeared to be amorphous material. The recrystallized and the amorphous lens-fibre material are similar to material found in cataractous lenses.

Cataract↗

PubMedDate not supplied

Microorganisms found in secondary cataract material of ECCE patients, a study with SEM and TEM.

Globular secondary cataract material, removed from 24 patients with ECCE after ophthalmic cleaning of the anterior capsule, were investigated with SEM and TEM. Besides spherical, somewhat oval shaped bodies of various shape and size comparable with those found in cataractous lenses, (an)aerobic bacteria and yeast cells were found in approximately 70% of the cases, all of them in eyes without intra-ocular inflammation. Probably these bacteria have been transferred from the conjunctiva during IOL.-implantation and were encapsulated without starting an inflammation.

Bacteria, Anaerobic↗

PubMedDate not supplied

The Morgagnian and Brunescens cataract morphology studied with with SEM and TEM.

The Morgagnian cataract lenses--pre-fixed with GA for SEM & TEM and post-fixed with tannic-acid-arginine-OsO4 for SEM and OsO4/K4Fe(CN)6 for TEM after staining with Ur-acetate/Pb-citrate--showed areas in the cortex with radial instead of concentric running lens fibres, degeneration of lens fibres with vacuoles and defected "ball & socket" connections. The presence of oval/spherical bodies of 0.5-20 microns was acknowledged, the largest of them having a golf-ball appearance and originating from the cytoplasm of the degenerating lens fibres; the smallest of them with an approximate size of 0.2-0.5 micron seemed to be formed by budding off from the microvilli of the furrowed lens epithelium. The Brunescens cataract lenses showed at low magnification no difference between lens fibres from the cortical area and the nucleus. The disintegration process of the lens fibres was observable as degradation of the ball & socket system and the existence of holes in the lens fibre body and emerging of spherical bodies from the cytoplasm. The globular structures seemed to be covered with a thin coating and were partly filled with a low density membranous-like material. In TEM-sections of the cataractous lens aterial vacuoles were visible consisting of a large number of smaller globules with a contents of low contrast low density membranous-like material, comparable with the globular structures seen in SEM.

Cataract↗