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Biomedical subjects

J D Cameron

Publications and source records attributed to J D Cameron.

At least 109 records · Page 6Linked to original sources

Presumed spontaneously regressed retinoblastoma.

A history of blindness in one eye since childhood, the fundus appearance of the other eye, and the family history of elevated plasma levels of carcinoembryonic (CEA) antigen and colorectal carcinoma led us to diagnose bilateral spontaneously regressed retinoblastoma. Massive gliosis of the retina was found in the eye enucleated because of blindness and pain. The diagnosis of regressed retinoblastoma should be considered where the pathologic diagnosis of an enucleated eye is massive gliosis of the retina, but where no known cause is present.

Adult↗

Goniodiathermy: experimental studies on ab interno filtration.

Goniodiathermy was carried out in rabbit eyes by first performing a goniopuncture with a Barkan knife followed by the introduction of an intraocular diathermy probe into the goniopuncture tract and heating of the cut ends of the scleral fibers. Histologic sections revealed that goniodiathermy produced a gaped wound in the scleral wall of the angle. Goniopuncture alone, without diathermy, resulted in a thin, well healed scar. Goniodiathermy appears to be a safe and feasible technique for creating a tract in the scleral wall of the anterior chamber angle in adult rabbits. This procedure, with modifications, may serve as a model for creating filtering blebs in the treatment of glaucoma in humans.

Adult↗

Human cornea organ cultures: epithelial-endothelial interactions.

Full-thickness explants of five human corneas grown in organ culture demonstrate that the migration of epithelium and endothelium is mutually limited once contact between the two cell types has been established. Two human corneas, however, failed to show this contact inhibition, and corneal epithelium surrounded completely the explant; both corneas showed cornea guttata. The implications of corneal epithelium-endothelium contact inhibition, and the failure of such inhibition, are discussed.

Adolescent↗

Biosynthesis of basement membrane collagen by rabbit corneal endothelium in vitro.

The synthesis of collagen has been demonstrated in endothelial cells of Descemet's membrane isolated from rabbit cornea. Incorporation of [14C]proline and [14C]lysine into nondialyzable protein was measured in the medium and cell fraction after incubating Descemet's membrane for up to 5 hours. In the [14C]collagen synthesized by the endothelium, 15% of the hydroxy[14C]proline was present as the 3-isomer. About 98% of the hydroxy[14C]lysine in the 14C-labeled-protein found in the medium was glycosylated; 95% of the glycosylated hydroxy[14C]lysine was in the form of the disaccharide glucosyl-galactosyl-hydroxy[14C]lysine. Time course experiments with [14C]proline indicated that there was a delay of about 60 min before significant amounts of [14C]collagen were secreted into the medium. The initial polypeptides of [14C]collagen synthesized by the corneal endothelium had an apparent molecular weight of 155,000. The chemical and physical properties of the [14C]collagen synthesized by rabbit corneal endothelium are consistent with those of basement membrane collagen synthesized by other cell types.

Animals↗

Rabbit corneal epithelial cells grown in vitro without serum.

Primary outgrowth cultures of normal rabbit corneal epithelium can be initiated and propagated in vitro up to 6 days in serum-free medium. By the eighth day the majority of cells have ceased to divide. Epithelial cells grown without serum show DNA synthetic activity at a level comparable to control cultures grown with added serum.

Animals↗

Postoperative extradural analgesia following thoracic surgery: a feasibility study.

The feasibility of providing postoperative analgesia using thoracic extradural blockade following thoracotomy has been assessed. Extradural block was produced by intermittent injections of 0.5% bupivacaine with adrenaline 1:200,000 or a continuous infusion of 0.25% or 0.125% bupivacaine. The only toxic symptom was drowsiness which was most frequent after a continuous infusion of 0.25% bupivacaine and with arterial plasma bupivacaine concentrations above 1.5 mug/ml. Arterial hypotension was a troublesome complication with all techniques although stability of arterial pressure was more easily achieved with a continuous infusion technique. However, this produced a high incidence of urinary retention. Practical aspects and effectiveness of providing extradural analgesia in patients following thoracotomy are discussed.

Aged↗